Update GN to 112.0.5615.213

Change-Id: I952ea0966149fd80f9171340fde3c6fa6ad1792f Reviewed-on: https://codereview.qt-project.org/c/qt/qtwebengine-chromium/+/481441 Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
author: Michal Klocek <michal.klocek@qt.io> 2023-06-03 07:33:02 +0200
committer: Michal Klocek <michal.klocek@qt.io> 2023-07-06 14:33:05 +0000
commit: 266cfa0fb83513250bcefd8234e0916c195a4b2e (patch)
tree: 762d08bbe1280c7e4b6324dbb53aae04477faa5a
parent: b5eefeb8ec4af885f132e9bb71e64192d719309b (diff)
169 files changed, 9750 insertions, 2292 deletions
diff --git a/gn/AUTHORS b/gn/AUTHORS
index 45cedd7e57a..5e1e5e69535 100644
--- a/gn/AUTHORS
+++ b/gn/AUTHORS
@@ -26,6 +26,7 @@ Alfredo Mazzinghi <mzz.lrd@gmail.com>
 Andrew Boyarshin <andrew.boyarshin@gmail.com>
 Anuj Kumar Sharma <anujk.sharma@samsung.com>
 DanCraft99 <simputest@gmail.com>
+Evangelos Foutras <evangelos@foutrelis.com>
 Gergely Nagy <ngg@ngg.hu>
 Ilia K <ki.stfu@gmail.com>
 Ivan Naydonov <samogot@gmail.com>
diff --git a/gn/OWNERS b/gn/OWNERS
index d78697cf06f..05715701270 100644
--- a/gn/OWNERS
+++ b/gn/OWNERS
@@ -1,3 +1,4 @@
 brettw@chromium.org
 phosek@chromium.org
 scottmg@chromium.org
+sdefresne@chromium.org
diff --git a/gn/README.md b/gn/README.md
index 75821c6d720..4bb1a9ec78e 100644
--- a/gn/README.md
+++ b/gn/README.md
@@ -51,7 +51,7 @@ some disadvanages:
     path. This isn't necessarily the correct trade-off for smaller projects.
 
   * The minimal build configuration is relatively heavyweight. There are several
-    files required and the exact way all compilers are linkers are run must be
+    files required and the exact way all compilers and linkers are run must be
     specified in the configuration (see "Examples" below). There is no default
     compiler configuration.
 
@@ -94,7 +94,7 @@ Alternatively, you can build GN from source with a C++17 compiler:
 
     git clone https://gn.googlesource.com/gn
     cd gn
-    python build/gen.py
+    python build/gen.py # --allow-warning if you want to build with warnings.
     ninja -C out
     # To run tests:
     out/gn_unittests
@@ -104,8 +104,8 @@ in `PATH`, so you'll want to run from a Visual Studio command prompt, or
 similar.
 
 On Linux, Mac and z/OS, the default compiler is `clang++`, a recent version is
-expected to be found in `PATH`. This can be overridden by setting `CC`, `CXX`,
-and `AR`.
+expected to be found in `PATH`. This can be overridden by setting the `CC`, `CXX`,
+and `AR` environment variables.
 
 On z/OS, building GN requires [ZOSLIB](https://github.com/ibmruntimes/zoslib) to be
 installed, as described at that URL. When building with `build/gen.py`, use the option
diff --git a/gn/build/build_win.ninja.template b/gn/build/build_win.ninja.template
index e2ca1861042..f1d17750c83 100644
--- a/gn/build/build_win.ninja.template
+++ b/gn/build/build_win.ninja.template
@@ -1,12 +1,12 @@
 rule cxx
-  command = ninja -t msvc -- $cxx /nologo /showIncludes /FC $includes $cflags /c $in /Fo$out
+  command = $cxx /nologo /showIncludes /FC $includes $cflags /c $in /Fo$out
   description = CXX $out
   deps = msvc
 
 rule alink_thin
-  command = ninja -t msvc -- $ar /nologo /ignore:4221 $libflags /OUT:$out $in
+  command = $ar /nologo /ignore:4221 $libflags /OUT:$out $in
   description = LIB $out
 
 rule link
-  command = ninja -t msvc -- $ld /nologo $ldflags /OUT:$out /PDB:$out.pdb $in $solibs $libs
+  command = $ld /nologo $ldflags /OUT:$out /PDB:$out.pdb $in $solibs $libs
   description = LINK $out
diff --git a/gn/build/full_test.py b/gn/build/full_test.py
index 46ba2de1634..79b4ac48365 100755
--- a/gn/build/full_test.py
+++ b/gn/build/full_test.py
@@ -33,7 +33,7 @@ def Trial(gn_path_to_use, save_out_dir=None):
 
 def main():
   if len(sys.argv) < 3 or len(sys.argv) > 4:
-    print 'Usage: full_test.py /chrome/tree/at/762a25542878 rel_gn_path [clean]'
+    print('Usage: full_test.py /chrome/tree/at/762a25542878 rel_gn_path [clean]')
     return 1
 
   if len(sys.argv) == 4:
@@ -57,7 +57,7 @@ def main():
 
   # First, do a comparison to make sure the output between the two gn binaries
   # actually matches.
-  print 'Confirming output matches...'
+  print('Confirming output matches...')
   dir_a = os.path.join('out', 'a')
   dir_b = os.path.join('out', 'b')
   Trial(in_chrome_tree_gn, dir_a)
@@ -66,13 +66,13 @@ def main():
 
   # Then, some time trials.
   TRIALS = 5
-  print 'Comparing performance... (takes a while)'
+  print('Comparing performance... (takes a while)')
   time_a = timeit.timeit('Trial("%s")' % in_chrome_tree_gn, number=TRIALS,
                          setup='from __main__ import Trial')
   time_b = timeit.timeit('Trial("%s")' % our_gn, number=TRIALS,
                          setup='from __main__ import Trial')
-  print 'In-tree gn avg: %.3fs' % (time_a / TRIALS)
-  print 'Our gn avg: %.3fs' % (time_b / TRIALS)
+  print('In-tree gn avg: %.3fs' % (time_a / TRIALS))
+  print('Our gn avg: %.3fs' % (time_b / TRIALS))
 
   return 0
 
diff --git a/gn/build/gen.py b/gn/build/gen.py
index ae9c40de8aa..2d109ed6cf3 100755
--- a/gn/build/gen.py
+++ b/gn/build/gen.py
@@ -17,9 +17,9 @@ import sys
 # GN's CI builders.
 
 try:  # py3
-    from shlex import quote as shell_quote
+  from shlex import quote as shell_quote
 except ImportError:  # py2
-    from pipes import quote as shell_quote
+  from pipes import quote as shell_quote
 
 SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
 REPO_ROOT = os.path.dirname(SCRIPT_DIR)
@@ -183,6 +183,9 @@ def main(argv):
                           'library, or \'-l<name>\' on POSIX systems. Can be ' +
                           'used multiple times. Useful to link custom malloc ' +
                           'or cpu profiling libraries.'))
+  args_list.add('--allow-warnings', action='store_true', default=False,
+                    help=('Allow compiler warnings, don\'t treat them as '
+                          'errors.'))
   if sys.platform == 'zos':
     args_list.add('--zoslib-dir',
                       action='store',
@@ -215,8 +218,8 @@ def main(argv):
 def GenerateLastCommitPosition(host, header):
   ROOT_TAG = 'initial-commit'
   describe_output = subprocess.check_output(
-      ['git', 'describe', 'HEAD', '--match', ROOT_TAG], shell=host.is_windows(),
-      cwd=REPO_ROOT)
+      ['git', 'describe', 'HEAD', '--abbrev=12', '--match', ROOT_TAG],
+      shell=host.is_windows(), cwd=REPO_ROOT)
   mo = re.match(ROOT_TAG + '-(\d+)-g([0-9a-f]+)', describe_output.decode())
   if not mo:
     raise ValueError(
@@ -296,7 +299,7 @@ def WriteGenericNinja(path, static_libraries, executables,
     object_ext = '.o'
 
   def escape_path_ninja(path):
-      return path.replace('$ ', '$$ ').replace(' ', '$ ').replace(':', '$:')
+    return path.replace('$ ', '$$ ').replace(' ', '$ ').replace(':', '$:')
 
   def src_to_obj(path):
     return escape_path_ninja('%s' % os.path.splitext(path)[0] + object_ext)
@@ -427,6 +430,9 @@ def WriteGNNinja(path, platform, host, options, args_list):
         cflags.extend(['-flto', '-fwhole-program-vtables'])
         ldflags.extend(['-flto', '-fwhole-program-vtables'])
 
+    if not options.allow_warnings:
+      cflags.append('-Werror')
+
     cflags.extend([
         '-D_FILE_OFFSET_BITS=64',
         '-D__STDC_CONSTANT_MACROS', '-D__STDC_FORMAT_MACROS',
@@ -438,9 +444,17 @@ def WriteGNNinja(path, platform, host, options, args_list):
         '-Wall',
         '-Wextra',
         '-Wno-unused-parameter',
+
+        '-Wextra-semi',
+        '-Wundef',
+
         '-std=c++17'
     ])
 
+    # flags not supported by gcc/g++.
+    if cxx == 'clang++':
+      cflags.extend(['-Wrange-loop-analysis', '-Wextra-semi-stmt'])
+
     if platform.is_linux() or platform.is_mingw() or platform.is_msys():
       ldflags.append('-Wl,--as-needed')
 
@@ -504,6 +518,9 @@ def WriteGNNinja(path, platform, host, options, args_list):
         libflags.extend(['/LTCG'])
         ldflags.extend(['/LTCG'])
 
+    if not options.allow_warnings:
+      cflags.append('/WX')
+
     cflags.extend([
         '/DNOMINMAX',
         '/DUNICODE',
@@ -515,7 +532,6 @@ def WriteGNNinja(path, platform, host, options, args_list):
         '/D_WIN32_WINNT=0x0A00',
         '/FS',
         '/W4',
-        '/WX',
         '/Zi',
         '/wd4099',
         '/wd4100',
@@ -559,7 +575,6 @@ def WriteGNNinja(path, platform, host, options, args_list):
         'src/base/strings/stringprintf.cc',
         'src/base/strings/utf_string_conversion_utils.cc',
         'src/base/strings/utf_string_conversions.cc',
-        'src/base/third_party/icu/icu_utf.cc',
         'src/base/timer/elapsed_timer.cc',
         'src/base/value_iterators.cc',
         'src/base/values.cc',
@@ -576,6 +591,7 @@ def WriteGNNinja(path, platform, host, options, args_list):
         'src/gn/bundle_data.cc',
         'src/gn/bundle_data_target_generator.cc',
         'src/gn/bundle_file_rule.cc',
+        'src/gn/builtin_tool.cc',
         'src/gn/c_include_iterator.cc',
         'src/gn/c_substitution_type.cc',
         'src/gn/c_tool.cc',
@@ -715,6 +731,7 @@ def WriteGNNinja(path, platform, host, options, args_list):
         'src/gn/xcode_object.cc',
         'src/gn/xcode_writer.cc',
         'src/gn/xml_element_writer.cc',
+        'src/util/atomic_write.cc',
         'src/util/exe_path.cc',
         'src/util/msg_loop.cc',
         'src/util/semaphore.cc',
@@ -790,6 +807,7 @@ def WriteGNNinja(path, platform, host, options, args_list):
         'src/gn/path_output_unittest.cc',
         'src/gn/pattern_unittest.cc',
         'src/gn/pointer_set_unittest.cc',
+        'src/gn/resolved_target_deps_unittest.cc',
         'src/gn/runtime_deps_unittest.cc',
         'src/gn/scope_per_file_provider_unittest.cc',
         'src/gn/scope_unittest.cc',
@@ -801,6 +819,7 @@ def WriteGNNinja(path, platform, host, options, args_list):
         'src/gn/string_utils_unittest.cc',
         'src/gn/substitution_pattern_unittest.cc',
         'src/gn/substitution_writer_unittest.cc',
+        'src/gn/target_public_pair_unittest.cc',
         'src/gn/target_unittest.cc',
         'src/gn/template_unittest.cc',
         'src/gn/test_with_scheduler.cc',
@@ -815,6 +834,7 @@ def WriteGNNinja(path, platform, host, options, args_list):
         'src/gn/visual_studio_writer_unittest.cc',
         'src/gn/xcode_object_unittest.cc',
         'src/gn/xml_element_writer_unittest.cc',
+        'src/util/atomic_write_unittest.cc',
         'src/util/test/gn_test.cc',
       ], 'libs': []},
   }
diff --git a/gn/docs/faq.md b/gn/docs/faq.md
index d300c906116..41a178de23a 100644
--- a/gn/docs/faq.md
+++ b/gn/docs/faq.md
@@ -171,6 +171,22 @@ date of the output. This approach also may appear to work but is subtly wrong:
 the additions of new files to the source directory will not trigger the build
 step and that addition will not be reflected in an incremental build.
 
+## How can I reference all files in a directory (glob)?
+
+Sometimes people want to automatically refer to all files in a directory,
+typically something like `"*.cc"` for the sources. This is called a "glob."
+
+Globs are not supported in GN. In order for Ninja to know when to re-run
+GN, it would need to check the directory modification times of any
+directories being globbed. Directory modification times that reflect
+additions and removals of files are not as reliably implemented across
+platforms and filesystems as file modification times (for example, it is
+not supported on Windows FAT32 drives).
+
+Even if directory modification times work properly on your build systems,
+GN's philosophy prefers a very explicit build specification style that
+is contrary to globs.
+
 ## Why does "gn check" complain about conditionally included headers?
 
 The "gn check" feature (see `gn help check`) validates that the source code's
diff --git a/gn/docs/reference.md b/gn/docs/reference.md
index 922f1d9d999..76ef2a9e503 100644
--- a/gn/docs/reference.md
+++ b/gn/docs/reference.md
@@ -34,7 +34,7 @@
     *   [shared_library: Declare a shared library target.](#func_shared_library)
     *   [source_set: Declare a source set target.](#func_source_set)
     *   [static_library: Declare a static library target.](#func_static_library)
-    *   [target: Declare an target with the given programmatic type.](#func_target)
+    *   [target: Declare a target with the given programmatic type.](#func_target)
 *   [Buildfile functions](#functions)
     *   [assert: Assert an expression is true at generation time.](#func_assert)
     *   [config: Defines a configuration object.](#func_config)
@@ -53,6 +53,7 @@
     *   [not_needed: Mark variables from scope as not needed.](#func_not_needed)
     *   [pool: Defines a pool object.](#func_pool)
     *   [print: Prints to the console.](#func_print)
+    *   [print_stack_trace: Prints a stack trace.](#func_print_stack_trace)
     *   [process_file_template: Do template expansion over a list of files.](#func_process_file_template)
     *   [read_file: Read a file into a variable.](#func_read_file)
     *   [rebase_path: Rebase a file or directory to another location.](#func_rebase_path)
@@ -124,6 +125,7 @@
     *   [framework_dirs: [directory list] Additional framework search directories.](#var_framework_dirs)
     *   [frameworks: [name list] Name of frameworks that must be linked.](#var_frameworks)
     *   [friend: [label pattern list] Allow targets to include private headers.](#var_friend)
+    *   [gen_deps: [label list] Declares targets that should generate when this one does.](#var_gen_deps)
     *   [include_dirs: [directory list] Additional include directories.](#var_include_dirs)
     *   [inputs: [file list] Additional compile-time dependencies.](#var_inputs)
     *   [ldflags: [string list] Flags passed to the linker.](#var_ldflags)
@@ -138,7 +140,7 @@
     *   [output_prefix_override: [boolean] Don't use prefix for output name.](#var_output_prefix_override)
     *   [outputs: [file list] Output files for actions and copy targets.](#var_outputs)
     *   [partial_info_plist: [filename] Path plist from asset catalog compiler.](#var_partial_info_plist)
-    *   [pool: [string] Label of the pool used by the action.](#var_pool)
+    *   [pool: [string] Label of the pool used by binary targets and actions.](#var_pool)
     *   [precompiled_header: [string] Header file to precompile.](#var_precompiled_header)
     *   [precompiled_header_type: [string] "gcc" or "msvc".](#var_precompiled_header_type)
     *   [precompiled_source: [file name] Source file to precompile.](#var_precompiled_source)
@@ -777,6 +779,7 @@
       "vs2015" - Visual Studio 2015 project/solution files.
       "vs2017" - Visual Studio 2017 project/solution files.
       "vs2019" - Visual Studio 2019 project/solution files.
+      "vs2022" - Visual Studio 2022 project/solution files.
       "xcode" - Xcode workspace/solution files.
       "qtcreator" - QtCreator project files.
       "json" - JSON file containing target information
@@ -825,6 +828,34 @@
       "legacy" - Legacy Build system
       "new" - New Build System
 
+  --xcode-configs=<config_name_list>
+      Configure the list of build configuration supported by the generated
+      project. If specified, must be a list of semicolon-separated strings.
+      If ommitted, a single configuration will be used in the generated
+      project derived from the build directory.
+
+  --xcode-config-build-dir=<string>
+      If present, must be a path relative to the source directory. It will
+      default to $root_out_dir if ommitted. The path is assumed to point to
+      the directory where ninja needs to be invoked. This variable can be
+      used to build for multiple configuration / platform / environment from
+      the same generated Xcode project (assuming that the user has created a
+      gn build directory with the correct args.gn for each).
+
+      One useful value is to use Xcode variables such as '${CONFIGURATION}'
+      or '${EFFECTIVE_PLATFORM}'.
+
+  --xcode-additional-files-patterns=<pattern_list>
+      If present, must be a list of semicolon-separated file patterns. It
+      will be used to add all files matching the pattern located in the
+      source tree to the project. It can be used to add, e.g. documentation
+      files to the project to allow easily edit them.
+
+  --xcode-additional-files-roots=<path_list>
+      If present, must be a list of semicolon-separated paths. It will be used
+      as roots when looking for additional files to add. If ommitted, defaults
+      to "//".
+
   --ninja-executable=<string>
       Can be used to specify the ninja executable to use when building.
 
@@ -888,21 +919,37 @@
       replay of individual compilations independent of the build system.
       This is an unstable format and likely to change without warning.
 
+  --add-export-compile-commands=<label_pattern>
+      Adds an additional label pattern (see "gn help label_pattern") of a
+      target to add to the compilation database. This pattern is appended to any
+      list values specified in the export_compile_commands variable in the
+      .gn file (see "gn help dotfile"). This allows the user to add additional
+      targets to the compilation database that the project doesn't add by default.
+
+      To add more than one value, specify this switch more than once. Each
+      invocation adds an additional label pattern.
+
+      Example:
+        --add-export-compile-commands=//tools:my_tool
+        --add-export-compile-commands="//base/*"
+
   --export-compile-commands[=<target_name1,target_name2...>]
-      Produces a compile_commands.json file in the root of the build directory
-      containing an array of “command objects”, where each command object
-      specifies one way a translation unit is compiled in the project. If a list
-      of target_name is supplied, only targets that are reachable from any
-      target in any build file whose name is target_name will be used for
-      “command objects” generation, otherwise all available targets will be used.
-      This is used for various Clang-based tooling, allowing for the replay of
-      individual compilations independent of the build system.
-      e.g. "foo" will match:
-      - "//path/to/src:foo"
-      - "//other/path:foo"
-      - "//foo:foo"
+      DEPRECATED https://bugs.chromium.org/p/gn/issues/detail?id=302.
+      Please use --add-export-compile-commands for per-user configuration, and
+      the "export_compile_commands" value in the project-level .gn file (see
+      "gn help dotfile") for per-project configuration.
+
+      Overrides the value of the export_compile_commands in the .gn file (see
+      "gn help dotfile") as well as the --add-export-compile-commands switch.
+
+      Unlike the .gn setting, this switch takes a legacy format which is a list
+      of target names that are matched in any directory. For example, "foo" will
+      match:
+       - "//path/to/src:foo"
+       - "//other/path:foo"
+       - "//foo:foo"
       and not match:
-      - "//foo:bar"
+       - "//foo:bar"
 ```
 ### <a name="cmd_help"></a>**gn help &lt;anything&gt;**
 
@@ -1013,17 +1060,18 @@
     A list of target labels from which to initiate the walk.
 
   --data
-    A list of keys from which to extract data. In each target walked, its metadata
-    scope is checked for the presence of these keys. If present, the contents of
-    those variable in the scope are appended to the results list.
+    A comma-separated list of keys from which to extract data. In each target
+    walked, its metadata scope is checked for the presence of these keys. If
+    present, the contents of those variable in the scope are appended to the
+    results list.
 
   --walk (optional)
-    A list of keys from which to control the walk. In each target walked, its
-    metadata scope is checked for the presence of any of these keys. If present,
-    the contents of those variables is checked to ensure that it is a label of
-    a valid dependency of the target and then added to the set of targets to walk.
-    If the empty string ("") is present in any of these keys, all deps and data_deps
-    are added to the walk set.
+    A comma-separated list of keys from which to control the walk. In each
+    target walked, its metadata scope is checked for the presence of any of
+    these keys. If present, the contents of those variables is checked to ensure
+    that it is a label of a valid dependency of the target and then added to the
+    set of targets to walk. If the empty string ("") is present in any of these
+    keys, all deps and data_deps are added to the walk set.
 
   --rebase (optional)
     A destination directory onto which to rebase any paths found. If set, all
@@ -1038,7 +1086,7 @@
       Lists collected metaresults for the `files` key in the //base/foo:foo
       target and all of its dependency tree.
 
-  gn meta out/Debug "//base/foo" --data=files --data=other
+  gn meta out/Debug "//base/foo" --data=files,other
       Lists collected metaresults for the `files` and `other` keys in the
       //base/foo:foo target and all of its dependency tree.
 
@@ -1309,6 +1357,12 @@
   and stuff like other Python files required to run your script in the "inputs"
   variable.
 
+  Actions can take the configs and public_configs lists, as well as any of the
+  configs variables (defines, include_dirs, etc.) set directly on the target.
+  These behave exactly as they would on a binary target and can be accessed
+  using substitution patterns in the script args (see "gn help args") to
+  implement custom compiler-like tools.
+
   The "deps" and "public_deps" for an action will always be
   completed before any part of the action is run so it can depend on
   the output of previous steps. The "data_deps" will be built if the
@@ -1351,8 +1405,20 @@
 #### **Variables**
 
 ```
-  args, data, data_deps, depfile, deps, inputs, metadata, outputs*, pool,
-  response_file_contents, script*, sources
+  Flags: asmflags, cflags, cflags_c, cflags_cc, cflags_objc,
+         cflags_objcc, defines, include_dirs, inputs, ldflags,
+         lib_dirs, libs, precompiled_header, precompiled_source,
+         rustenv, rustflags, swiftflags, testonly
+  Dependent configs: all_dependent_configs, public_configs
+  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,
+        write_runtime_deps
+  General: check_includes, configs, data, friend, inputs, metadata,
+           output_extension, output_name, public, sources, testonly,
+           visibility
+  Action variables: args, bridge_header, configs, data, depfile,
+                    framework_dirs, inputs, module_deps, module_name,
+                    outputs*, pool, response_file_contents, script*,
+                    sources
   * = required
 ```
 
@@ -1440,8 +1506,20 @@
 #### **Variables**
 
 ```
-  args, data, data_deps, depfile, deps, inputs, metadata, outputs*, pool,
-  response_file_contents, script*, sources*
+  Flags: asmflags, cflags, cflags_c, cflags_cc, cflags_objc,
+         cflags_objcc, defines, include_dirs, inputs, ldflags,
+         lib_dirs, libs, precompiled_header, precompiled_source,
+         rustenv, rustflags, swiftflags, testonly
+  Dependent configs: all_dependent_configs, public_configs
+  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,
+        write_runtime_deps
+  General: check_includes, configs, data, friend, inputs, metadata,
+           output_extension, output_name, public, sources, testonly,
+           visibility
+  Action variables: args, bridge_header, configs, data, depfile,
+                    framework_dirs, inputs, module_deps, module_name,
+                    outputs*, pool, response_file_contents, script*,
+                    sources
   * = required
 ```
 
@@ -1493,7 +1571,13 @@
 #### **Variables**
 
 ```
-  sources*, outputs*, deps, data_deps, metadata, public_deps, visibility
+  Dependent configs: all_dependent_configs, public_configs
+  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,
+        write_runtime_deps
+  General: check_includes, configs, data, friend, inputs, metadata,
+           output_extension, output_name, public, sources, testonly,
+           visibility
+  Bundle-specific: sources*, outputs*
   * = required
 ```
 
@@ -1543,6 +1627,23 @@
   mapping from each source file to an output file name using source expansion
   (see "gn help source_expansion"). The placeholders will look like
   "{{source_name_part}}", for example.
+
+  If you want to copy the output of a previous build step, the target that
+  generates the file to copy must be reachable from the deps or public_deps of
+  the copy target.
+```
+
+#### **Variables**
+
+```
+  Dependent configs: all_dependent_configs, public_configs
+  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,
+        write_runtime_deps
+  General: check_includes, configs, data, friend, inputs, metadata,
+           output_extension, output_name, public, sources, testonly,
+           visibility
+  Copy variables: sources*, outputs*
+  * = required
 ```
 
 #### **Examples**
@@ -1562,6 +1663,24 @@
     # names in the gen dir. This will just copy each file.
     outputs = [ "$target_gen_dir/{{source_file_part}}" ]
   }
+
+  # Copy the output of a generated executable.
+  copy("package_melon") {
+    # This example uses get_label_info() to compute the output directory of the
+    # dependency. This allows the copy rule to work regardless of the toolchain.
+    #
+    # In some cases (particularly actions defined previously in the same file)
+    # you can use get_target_outputs() to get the input file which can eliminate
+    # the assumptions about the output file name of the dependency.
+
+    input_dir = get_label_info("//src/tools/melon", "root_out_dir");
+    sources = [ "$input_dir/melon" ]
+
+    outputs = [ "$target_gen_dir/{{source_file_part}}" ]
+
+    # Depend on the target to build the file before copying.
+    deps = [ "//src/tools/melon" ]
+  }
 ```
 ### <a name="func_create_bundle"></a>**create_bundle**: [ios/macOS] Build an iOS or macOS bundle.
 
@@ -1607,11 +1726,17 @@
 #### **Variables**
 
 ```
-  bundle_root_dir, bundle_contents_dir, bundle_resources_dir,
-  bundle_executable_dir, bundle_deps_filter, deps, data_deps, public_deps,
-  visibility, product_type, code_signing_args, code_signing_script,
-  code_signing_sources, code_signing_outputs, xcode_extra_attributes,
-  xcode_test_application_name, partial_info_plist, metadata
+  Dependent configs: all_dependent_configs, public_configs
+  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,
+        write_runtime_deps
+  General: check_includes, configs, data, friend, inputs, metadata,
+           output_extension, output_name, public, sources, testonly,
+           visibility
+  Bundle vars: bundle_root_dir, bundle_contents_dir, bundle_resources_dir,
+               bundle_executable_dir, bundle_deps_filter, product_type,
+               code_signing_args, code_signing_script, code_signing_sources,
+               code_signing_outputs, xcode_extra_attributes,
+               xcode_test_application_name, partial_info_plist
 ```
 
 #### **Example**
@@ -1728,14 +1853,15 @@
 #### **Variables**
 
 ```
-  Flags: cflags, cflags_c, cflags_cc, cflags_objc, cflags_objcc,
-         asmflags, defines, include_dirs, inputs, ldflags, lib_dirs,
-         libs, precompiled_header, precompiled_source, rustflags,
-         rustenv, swiftflags
-  Deps: data_deps, deps, public_deps
+  Flags: asmflags, cflags, cflags_c, cflags_cc, cflags_objc,
+         cflags_objcc, defines, include_dirs, inputs, ldflags,
+         lib_dirs, libs, precompiled_header, precompiled_source,
+         rustenv, rustflags, swiftflags, testonly
+  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,
+        write_runtime_deps
   Dependent configs: all_dependent_configs, public_configs
   General: check_includes, configs, data, friend, inputs, metadata,
-           output_name, output_extension, public, sources, testonly,
+           output_extension, output_name, public, sources, testonly,
            visibility
   Rust variables: aliased_deps, crate_root, crate_name
 ```
@@ -1763,6 +1889,18 @@
   dependencies. See the example for details.
 ```
 
+#### **Variables**
+
+```
+  Dependent configs: all_dependent_configs, public_configs
+  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,
+        write_runtime_deps
+  General: check_includes, configs, data, friend, inputs, metadata,
+           output_extension, output_name, public, sources, testonly,
+           visibility
+  Generated file: contents, data_keys, rebase, walk_keys, output_conversion
+```
+
 #### **Example (metadata collection)**
 
 ```
@@ -1860,18 +1998,6 @@
       "../base/foo.cpp",  // from //base:a
     ]
 ```
-
-#### **Variables**
-
-```
-  contents
-  data_keys
-  rebase
-  walk_keys
-  output_conversion
-  Deps: data_deps, deps, public_deps
-  Dependent configs: all_dependent_configs, public_configs
-```
 ### <a name="func_group"></a>**group**: Declare a named group of targets.
 
 ```
@@ -1883,8 +2009,12 @@
 #### **Variables**
 
 ```
-  Deps: data_deps, deps, public_deps
+  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,
+        write_runtime_deps
   Dependent configs: all_dependent_configs, public_configs
+  General: check_includes, configs, data, friend, inputs, metadata,
+           output_extension, output_name, public, sources, testonly,
+           visibility
 ```
 
 #### **Example**
@@ -1922,14 +2052,15 @@
 #### **Variables**
 
 ```
-  Flags: cflags, cflags_c, cflags_cc, cflags_objc, cflags_objcc,
-         asmflags, defines, include_dirs, inputs, ldflags, lib_dirs,
-         libs, precompiled_header, precompiled_source, rustflags,
-         rustenv, swiftflags
-  Deps: data_deps, deps, public_deps
+  Flags: asmflags, cflags, cflags_c, cflags_cc, cflags_objc,
+         cflags_objcc, defines, include_dirs, inputs, ldflags,
+         lib_dirs, libs, precompiled_header, precompiled_source,
+         rustenv, rustflags, swiftflags, testonly
+  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,
+        write_runtime_deps
   Dependent configs: all_dependent_configs, public_configs
   General: check_includes, configs, data, friend, inputs, metadata,
-           output_name, output_extension, public, sources, testonly,
+           output_extension, output_name, public, sources, testonly,
            visibility
   Rust variables: aliased_deps, crate_root, crate_name, crate_type
 ```
@@ -1954,14 +2085,15 @@
 #### **Variables**
 
 ```
-  Flags: cflags, cflags_c, cflags_cc, cflags_objc, cflags_objcc,
-         asmflags, defines, include_dirs, inputs, ldflags, lib_dirs,
-         libs, precompiled_header, precompiled_source, rustflags,
-         rustenv, swiftflags
-  Deps: data_deps, deps, public_deps
+  Flags: asmflags, cflags, cflags_c, cflags_cc, cflags_objc,
+         cflags_objcc, defines, include_dirs, inputs, ldflags,
+         lib_dirs, libs, precompiled_header, precompiled_source,
+         rustenv, rustflags, swiftflags, testonly
+  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,
+        write_runtime_deps
   Dependent configs: all_dependent_configs, public_configs
   General: check_includes, configs, data, friend, inputs, metadata,
-           output_name, output_extension, public, sources, testonly,
+           output_extension, output_name, public, sources, testonly,
            visibility
   Rust variables: aliased_deps, crate_root, crate_name
 ```
@@ -1989,14 +2121,15 @@
 #### **Variables**
 
 ```
-  Flags: cflags, cflags_c, cflags_cc, cflags_objc, cflags_objcc,
-         asmflags, defines, include_dirs, inputs, ldflags, lib_dirs,
-         libs, precompiled_header, precompiled_source, rustflags,
-         rustenv, swiftflags
-  Deps: data_deps, deps, public_deps
+  Flags: asmflags, cflags, cflags_c, cflags_cc, cflags_objc,
+         cflags_objcc, defines, include_dirs, inputs, ldflags,
+         lib_dirs, libs, precompiled_header, precompiled_source,
+         rustenv, rustflags, swiftflags, testonly
+  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,
+        write_runtime_deps
   Dependent configs: all_dependent_configs, public_configs
   General: check_includes, configs, data, friend, inputs, metadata,
-           output_name, output_extension, public, sources, testonly,
+           output_extension, output_name, public, sources, testonly,
            visibility
   Rust variables: aliased_deps, crate_root, crate_name
 ```
@@ -2023,14 +2156,15 @@
 #### **Variables**
 
 ```
-  Flags: cflags, cflags_c, cflags_cc, cflags_objc, cflags_objcc,
-         asmflags, defines, include_dirs, inputs, ldflags, lib_dirs,
-         libs, precompiled_header, precompiled_source, rustflags,
-         rustenv, swiftflags
-  Deps: data_deps, deps, public_deps
+  Flags: asmflags, cflags, cflags_c, cflags_cc, cflags_objc,
+         cflags_objcc, defines, include_dirs, inputs, ldflags,
+         lib_dirs, libs, precompiled_header, precompiled_source,
+         rustenv, rustflags, swiftflags, testonly
+  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,
+        write_runtime_deps
   Dependent configs: all_dependent_configs, public_configs
   General: check_includes, configs, data, friend, inputs, metadata,
-           output_name, output_extension, public, sources, testonly,
+           output_extension, output_name, public, sources, testonly,
            visibility
   Rust variables: aliased_deps, crate_root, crate_name, crate_type
 ```
@@ -2068,14 +2202,15 @@
 #### **Variables**
 
 ```
-  Flags: cflags, cflags_c, cflags_cc, cflags_objc, cflags_objcc,
-         asmflags, defines, include_dirs, inputs, ldflags, lib_dirs,
-         libs, precompiled_header, precompiled_source, rustflags,
-         rustenv, swiftflags
-  Deps: data_deps, deps, public_deps
+  Flags: asmflags, cflags, cflags_c, cflags_cc, cflags_objc,
+         cflags_objcc, defines, include_dirs, inputs, ldflags,
+         lib_dirs, libs, precompiled_header, precompiled_source,
+         rustenv, rustflags, swiftflags, testonly
+  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,
+        write_runtime_deps
   Dependent configs: all_dependent_configs, public_configs
   General: check_includes, configs, data, friend, inputs, metadata,
-           output_name, output_extension, public, sources, testonly,
+           output_extension, output_name, public, sources, testonly,
            visibility
 ```
 ### <a name="func_static_library"></a>**static_library**: Declare a static library target.
@@ -2092,14 +2227,15 @@
 
 ```
   complete_static_lib
-  Flags: cflags, cflags_c, cflags_cc, cflags_objc, cflags_objcc,
-         asmflags, defines, include_dirs, inputs, ldflags, lib_dirs,
-         libs, precompiled_header, precompiled_source, rustflags,
-         rustenv, swiftflags
-  Deps: data_deps, deps, public_deps
+  Flags: asmflags, cflags, cflags_c, cflags_cc, cflags_objc,
+         cflags_objcc, defines, include_dirs, inputs, ldflags,
+         lib_dirs, libs, precompiled_header, precompiled_source,
+         rustenv, rustflags, swiftflags, testonly
+  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,
+        write_runtime_deps
   Dependent configs: all_dependent_configs, public_configs
   General: check_includes, configs, data, friend, inputs, metadata,
-           output_name, output_extension, public, sources, testonly,
+           output_extension, output_name, public, sources, testonly,
            visibility
   Rust variables: aliased_deps, crate_root, crate_name
 
@@ -2109,7 +2245,7 @@
   target containing both C and C++ sources is acceptable, but a
   target containing C and Rust sources is not).
 ```
-### <a name="func_target"></a>**target**: Declare an target with the given programmatic type.
+### <a name="func_target"></a>**target**: Declare a target with the given programmatic type.
 
 ```
   target(target_type_string, target_name_string) { ... }
@@ -2128,6 +2264,20 @@
     source_set("doom_melon") {
 ```
 
+#### **Common target variables**
+
+```
+  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,
+        write_runtime_deps
+  Dependent configs: all_dependent_configs, public_configs
+  General: check_includes, configs, data, friend, inputs, metadata,
+           output_extension, output_name, public, sources, testonly,
+           visibility
+
+  Targets will also have variables specific to that type, see "gn help <type>"
+  for more.
+```
+
 #### **Example**
 
 ```
@@ -2201,10 +2351,10 @@
 #### **Variables valid in a config definition**
 
 ```
-  Flags: cflags, cflags_c, cflags_cc, cflags_objc, cflags_objcc,
-         asmflags, defines, include_dirs, inputs, ldflags, lib_dirs,
-         libs, precompiled_header, precompiled_source, rustflags,
-         rustenv, swiftflags
+  Flags: asmflags, cflags, cflags_c, cflags_cc, cflags_objc,
+         cflags_objcc, defines, include_dirs, inputs, ldflags,
+         lib_dirs, libs, precompiled_header, precompiled_source,
+         rustenv, rustflags, swiftflags, testonly
   Nested configs: configs
   General: visibility
 ```
@@ -2865,6 +3015,35 @@
 
   print(sources, deps)
 ```
+### <a name="func_print_stack_trace"></a>**print_stack_trace**: Prints a stack trace.
+
+```
+  Prints the current file location, and all template invocations that led up to
+  this location, to the console.
+```
+
+#### **Examples**
+
+```
+  template("foo"){
+    print_stack_trace()
+  }
+  template("bar"){
+    foo(target_name + ".foo") {
+      baz = invoker.baz
+    }
+  }
+  bar("lala") {
+    baz = 42
+  }
+
+  will print out the following:
+
+  print_stack_trace() initiated at  //build.gn:2
+    bar("lala")  //BUILD.gn:9
+    foo("lala.foo")  //BUILD.gn:5
+    print_stack_trace()  //BUILD.gn:2
+```
 ### <a name="func_process_file_template"></a>**process_file_template**: Do template expansion over a list of files.
 
 ```
@@ -4377,6 +4556,13 @@
   - "arm"
   - "arm64"
   - "mipsel"
+  - "mips64el"
+  - "s390x"
+  - "ppc64"
+  - "riscv32"
+  - "riscv64"
+  - "e2k"
+  - "loong64"
 ```
 ### <a name="var_target_gen_dir"></a>**target_gen_dir**: Directory for a target's generated files.
 
@@ -4686,6 +4872,14 @@
   to the script. Typically you would use source expansion (see "gn help
   source_expansion") to insert the source file names.
 
+  Args can also expand the substitution patterns corresponding to config
+  variables in the same way that compiler tools (see "gn help tool") do. These
+  allow actions that run compiler or compiler-like tools to access the results
+  of propagating configs through the build graph. For example:
+
+  args = [ "{{defines}}", "{{include_dirs}}", "{{rustenv}}", "--input-file",
+           "{{source}}" ]
+
   See also "gn help action" and "gn help action_foreach".
 ```
 ### <a name="var_asmflags"></a>**asmflags**: Flags passed to the assembler.
@@ -5395,10 +5589,10 @@
 
     # Locate the depfile in the output directory named like the
     # inputs but with a ".d" appended.
-    depfile = "$relative_target_output_dir/{{source_name}}.d"
+    depfile = "$target_gen_dir/{{source_name_part}}.d"
 
     # Say our script uses "-o <d file>" to indicate the depfile.
-    args = [ "{{source}}", "-o", depfile ]
+    args = [ "{{source}}", "-o", rebase_path(depfile, root_build_dir)]
   }
 ```
 ### <a name="var_deps"></a>**deps**: Private linked dependencies.
@@ -5583,6 +5777,18 @@
     ]
   }
 ```
+### <a name="var_gen_deps"></a>**gen_deps**: Declares targets that should generate when this one does.
+
+```
+  A list of target labels.
+
+  Not all GN targets that get evaluated are actually turned into ninja targets
+  (see "gn help execution"). If this target is generated, then any targets in
+  the "gen_deps" list will also be generated, regardless of the usual critera.
+
+  Since "gen_deps" are not build time dependencies, there can be cycles between
+  "deps" and "gen_deps" or within "gen_deps" itself.
+```
 ### <a name="var_include_dirs"></a>**include_dirs**: Additional include directories.
 
 ```
@@ -6011,16 +6217,21 @@
   The file will be generated regardless of whether the asset compiler has
   been invoked or not. See "gn help create_bundle".
 ```
-### <a name="var_pool"></a>**pool**: Label of the pool used by the action.
+### <a name="var_pool"></a>**pool**: Label of the pool used by binary targets actions.
 
 ```
-  A fully-qualified label representing the pool that will be used for the
-  action. Pools are defined using the pool() {...} declaration.
+  A fully-qualified label representing the pool that will be used for binary
+  targets and actions. Pools are defined using the pool() {...} declaration.
 ```
 
 #### **Example**
 
 ```
+  executable("binary") {
+    pool = "//build:custom_pool"
+    ...
+  }
+
   action("action") {
     pool = "//build:custom_pool"
     ...
@@ -6763,6 +6974,28 @@
           "//build/my_config.gni",
         ]
 
+  export_compile_commands [optional]
+      A list of label patterns for which to generate a Clang compilation
+      database (see "gn help label_pattern" for the string format).
+
+      When specified, GN will generate a compile_commands.json file in the root
+      of the build directory containing information on how to compile each
+      source file reachable from any label matching any pattern in the list.
+      This is used for Clang-based tooling and some editor integration. See
+      https://clang.llvm.org/docs/JSONCompilationDatabase.html
+
+      The switch --add-export-compile-commands to "gn gen" (see "gn help gen")
+      appends to this value which provides a per-user way to customize it.
+
+      The deprecated switch --export-compile-commands to "gn gen" (see "gn help
+      gen") adds to the export target list using a different format.
+
+      Example:
+        export_compile_commands = [
+          "//base/*",
+          "//tools:doom_melon",
+        ]
+
   root [optional]
       Label of the root build target. The GN build will start by loading the
       build file containing this target name. This defaults to "//:" which will
@@ -6773,12 +7006,14 @@
       help --root-target").
 
   script_executable [optional]
-      Path to specific Python executable or other interpreter to use in
-      action targets and exec_script calls. By default GN searches the
-      PATH for Python to execute these scripts.
+      By default, GN runs the scripts used in action targets and exec_script
+      calls using the Python interpreter found in PATH. This value specifies the
+      Python executable or other interpreter to use instead.
+
+      If set to the empty string, the scripts will be executed directly.
 
-      If set to the empty string, the path specified in action targets
-      and exec_script calls will be executed directly.
+      The command-line switch --script-executable will override this value (see
+      "gn help --script-executable")
 
   secondary_source [optional]
       Label of an alternate directory tree to find input files. When searching
@@ -6903,6 +7138,13 @@
   required (directly or transitively) to build a target in the default
   toolchain.
 
+  Some targets might be associated but without a formal build dependency (for
+  example, related tools or optional variants). A target that is marked as
+  "generated" can propagate its generated state to an associated target using
+  "gen_deps". This will make the referenced dependency have Ninja rules
+  generated in the same cases the source target has but without a build-time
+  dependency and even in non-default toolchains.
+
   See also "gn help ninja_rules".
 ```
 
@@ -7109,19 +7351,20 @@
 ```
   All execution happens in the context of a scope which holds the current state
   (like variables). With the exception of loops and conditions, '{' introduces
-  a new scope that has a parent reference to the old scope.
+  a new scope.
 
-  Variable reads recursively search all nested scopes until the variable is
-  found or there are no more scopes. Variable writes always go into the current
-  scope. This means that after the closing '}' (again excepting loops and
-  conditions), all local variables will be restored to the previous values.
-  This also means that "foo = foo" can do useful work by copying a variable
-  into the current scope that was defined in a containing scope.
+  Most scopes have a parent reference to the old scope. Variable reads
+  recursively search all parent scopes until the variable is found or there are
+  no more scopes. Variable writes always go into the current scope. This means
+  that after the closing '}' (again excepting loops and conditions), all local
+  variables will be restored to the previous values.  This also means that "foo
+  = foo" can do useful work by copying a variable into the current scope that
+  was defined in a containing scope.
 
-  Scopes can also be assigned to variables. Such scopes can be created by
-  functions like exec_script, when invoking a template (the template code
-  refers to the variables set by the invoking code by the implicitly-created
-  "invoker" scope), or explicitly like:
+  Scopes can be assigned to variables. Examples of such scopes are the
+  implicitly-created "invoker" when invoking a template (which refers to the
+  variables set by the invoking code), scopes created by functions like
+  exec_script, and scopes explicitly created like
 
     empty_scope = {}
     myvalues = {
@@ -7129,10 +7372,14 @@
       bar = "something"
     }
 
-  Inside such a scope definition can be any GN code including conditionals and
-  function calls. After the close of the scope, it will contain all variables
-  explicitly set by the code contained inside it. After this, the values can be
-  read, modified, or added to:
+  In the case of explicitly created scopes and scopes created by functions like
+  exec_script, there is no reference to the parent scope. Such scopes are fully
+  self-contained and do not "inherit" values from their defining scope.
+
+  Inside an explicit scope definition can be any GN code including conditionals
+  and function calls. After the close of the scope, it will contain all
+  variables explicitly set by the code contained inside it. After this, the
+  values can be read, modified, or added to:
 
     myvalues.foo += 2
     empty_scope.new_thing = [ 1, 2, 3 ]
@@ -7552,6 +7799,10 @@
        short name. Use "ninja doom_melon" to compile the
        "//tools/fruit:doom_melon" executable.
 
+       Note that for Apple platforms, create_bundle targets with a product_type
+       of "com.apple.product-type.application" are considered as executable
+       for this rule (as they define application bundles).
+
     5. The short names of all targets if there is only one target with that
        short name.
 
diff --git a/gn/examples/ios/.gn b/gn/examples/ios/.gn
index e5b6d4a3db7..fc31273e4cc 100644
--- a/gn/examples/ios/.gn
+++ b/gn/examples/ios/.gn
@@ -1,2 +1,6 @@
 # The location of the build configuration file.
 buildconfig = "//build/BUILDCONFIG.gn"
+
+# The build script are using `python3` which is the only version of
+# python installed by default on macOS Monterey and above.
+script_executable = "python3"
diff --git a/gn/examples/ios/build/BUILD.gn b/gn/examples/ios/build/BUILD.gn
index b6bb6de8079..e543493a550 100644
--- a/gn/examples/ios/build/BUILD.gn
+++ b/gn/examples/ios/build/BUILD.gn
@@ -77,6 +77,8 @@ if (current_os == "ios" || current_os == "mac") {
                           [
                             "--target-cpu",
                             current_cpu,
+                            "--target-environment",
+                            target_environment,
                             "--deployment-target",
                             ios_deployment_target,
                           ],
diff --git a/gn/examples/ios/build/BUILDCONFIG.gn b/gn/examples/ios/build/BUILDCONFIG.gn
index 53ee3d9ab69..ca6c49d56a2 100644
--- a/gn/examples/ios/build/BUILDCONFIG.gn
+++ b/gn/examples/ios/build/BUILDCONFIG.gn
@@ -15,6 +15,16 @@ if (current_os == "") {
   current_os = target_os
 }
 
+declare_args() {
+  # Control which platform the build is targeting. Valid values are
+  # "simulator" or "device".
+  target_environment = "simulator"
+}
+
+assert(
+    target_environment == "simulator" || target_environment == "device",
+    "Only supported values for target_environment are 'simulator' and 'device'")
+
 # All binary targets will get this list of configs by default.
 _shared_binary_target_configs = [ "//build:compiler" ]
 
diff --git a/gn/examples/ios/build/config/ios/scripts/find_app_identifier_prefix.py b/gn/examples/ios/build/config/ios/scripts/find_app_identifier_prefix.py
index cf38b10d198..9e1dfbc2138 100644
--- a/gn/examples/ios/build/config/ios/scripts/find_app_identifier_prefix.py
+++ b/gn/examples/ios/build/config/ios/scripts/find_app_identifier_prefix.py
@@ -21,7 +21,7 @@ class ProvisioningProfile(object):
 
   def __init__(self, mobileprovision_path):
     self._path = mobileprovision_path
-    self._data = plistlib.readPlistFromString(
+    self._data = plistlib.loads(
         subprocess.check_output(
             ['security', 'cms', '-D', '-i', mobileprovision_path]))
 
diff --git a/gn/examples/ios/build/config/ios/scripts/merge_plist.py b/gn/examples/ios/build/config/ios/scripts/merge_plist.py
index 452cf534f9f..f13ce007750 100644
--- a/gn/examples/ios/build/config/ios/scripts/merge_plist.py
+++ b/gn/examples/ios/build/config/ios/scripts/merge_plist.py
@@ -18,11 +18,15 @@ import sys
 VARIABLE_PATTERN = re.compile(r'\$\(([^)]*)\)')
 
 
+def GetCommandOutput(command):
+  """Returns the output of `command` as a string."""
+  return subprocess.check_output(command, encoding='utf-8')
+
+
 def LoadPlist(plist_path):
   """Loads Apple Property List file at |plist_path|."""
   return json.loads(
-      subprocess.check_output(
-          ['plutil', '-convert', 'json', '-o', '-', plist_path]))
+      GetCommandOutput(['plutil', '-convert', 'json', '-o', '-', plist_path]))
 
 
 def SavePlist(plist_path, content, format):
@@ -30,7 +34,7 @@ def SavePlist(plist_path, content, format):
   proc = subprocess.Popen(
       ['plutil', '-convert', format, '-o', plist_path, '-'],
       stdin=subprocess.PIPE)
-  output, _ = proc.communicate(json.dumps(content))
+  output, _ = proc.communicate(json.dumps(content).encode('utf-8'))
   if proc.returncode:
     raise subprocess.CalledProcessError(
         proc.returncode,
@@ -76,7 +80,7 @@ def PerformSubstitutions(plist, substitutions):
   if isinstance(plist, list):
     return [ PerformSubstitutions(item, substitutions) for item in plist ]
 
-  if isinstance(plist, (str, unicode)):
+  if isinstance(plist, str):
     result = plist
     while True:
       match = VARIABLE_PATTERN.search(result)
diff --git a/gn/examples/ios/build/config/ios/scripts/sdk_info.py b/gn/examples/ios/build/config/ios/scripts/sdk_info.py
index 831a3ed1e43..c8f55cb475b 100644
--- a/gn/examples/ios/build/config/ios/scripts/sdk_info.py
+++ b/gn/examples/ios/build/config/ios/scripts/sdk_info.py
@@ -16,6 +16,11 @@ XCODE_VERSION_PATTERN = re.compile(r'Xcode (\d+)\.(\d+)')
 XCODE_BUILD_PATTERN = re.compile(r'Build version (.*)')
 
 
+def GetCommandOutput(command):
+  """Returns the output of `command` as a string."""
+  return subprocess.check_output(command, encoding='utf-8')
+
+
 def GetAppleCpuName(target_cpu):
   """Returns the name of the |target_cpu| using Apple's convention."""
   return {
@@ -25,36 +30,31 @@ def GetAppleCpuName(target_cpu):
   }.get(target_cpu, target_cpu)
 
 
-def IsSimulator(target_cpu):
-  """Returns whether the |target_cpu| corresponds to a simulator build."""
-  return not target_cpu.startswith('arm')
-
-
-def GetPlatform(target_cpu):
-  """Returns the platform for the |target_cpu|."""
-  if IsSimulator(target_cpu):
-    return 'iphonesimulator'
-  else:
-    return 'iphoneos'
+def GetPlatform(target_environment):
+  """Returns the platform for |target_environment|."""
+  return {
+      'simulator': 'iphonesimulator',
+      'device': 'iphoneos'
+  }[target_environment]
 
 
-def GetPlaformDisplayName(target_cpu):
-  """Returns the platform display name for the |target_cpu|."""
-  if IsSimulator(target_cpu):
-    return 'iPhoneSimulator'
-  else:
-    return 'iPhoneOS'
+def GetPlaformDisplayName(target_environment):
+  """Returns the platform display name for |target_environment|."""
+  return {
+      'simulator': 'iPhoneSimulator',
+      'device': 'iPhoneOS'
+  }[target_environment]
 
 
 def ExtractOSVersion():
   """Extract the version of macOS of the current machine."""
-  return subprocess.check_output(['sw_vers', '-buildVersion']).strip()
+  return GetCommandOutput(['sw_vers', '-buildVersion']).strip()
 
 
 def ExtractXcodeInfo():
   """Extract Xcode version and build version."""
   version, build = None, None
-  for line in subprocess.check_output(['xcodebuild', '-version']).splitlines():
+  for line in GetCommandOutput(['xcodebuild', '-version']).splitlines():
     match = XCODE_VERSION_PATTERN.search(line)
     if match:
       major, minor = match.group(1), match.group(2)
@@ -72,23 +72,22 @@ def ExtractXcodeInfo():
 
 def ExtractSDKInfo(info, sdk):
   """Extract information about the SDK."""
-  return subprocess.check_output(
-      ['xcrun', '--sdk', sdk, '--show-sdk-' + info]).strip()
+  return GetCommandOutput(['xcrun', '--sdk', sdk, '--show-sdk-' + info]).strip()
 
 
 def GetDeveloperDir():
   """Returns the developer dir."""
-  return subprocess.check_output(['xcode-select', '-print-path']).strip()
+  return GetCommandOutput(['xcode-select', '-print-path']).strip()
 
 
-def GetSDKInfoForCpu(target_cpu, sdk_version, deployment_target):
+def GetSDKInfoForCpu(target_cpu, environment, sdk_version, deployment_target):
   """Returns a dictionary with information about the SDK."""
-  platform = GetPlatform(target_cpu)
+  platform = GetPlatform(environment)
   sdk_version = sdk_version or ExtractSDKInfo('version', platform)
   deployment_target = deployment_target or sdk_version
 
   target = target_cpu + '-apple-ios' + deployment_target
-  if IsSimulator(target_cpu):
+  if environment == 'simulator':
     target = target + '-simulator'
 
   xcode_version, xcode_build = ExtractXcodeInfo()
@@ -96,10 +95,10 @@ def GetSDKInfoForCpu(target_cpu, sdk_version, deployment_target):
 
   sdk_info = {}
   sdk_info['compiler'] = 'com.apple.compilers.llvm.clang.1_0'
-  sdk_info['is_simulator'] = IsSimulator(target_cpu)
+  sdk_info['is_simulator'] = environment == 'simulator'
   sdk_info['macos_build'] = ExtractOSVersion()
   sdk_info['platform'] = platform
-  sdk_info['platform_name'] = GetPlaformDisplayName(target_cpu)
+  sdk_info['platform_name'] = GetPlaformDisplayName(environment)
   sdk_info['sdk'] = effective_sdk
   sdk_info['sdk_build'] = ExtractSDKInfo('build-version', effective_sdk)
   sdk_info['sdk_path'] = ExtractSDKInfo('path', effective_sdk)
@@ -124,6 +123,12 @@ def ParseArgs(argv):
       choices=('x86', 'x64', 'arm', 'arm64'),
       help='target cpu')
   parser.add_argument(
+      '-e',
+      '--target-environment',
+      default='simulator',
+      choices=('simulator', 'device'),
+      help='target environment')
+  parser.add_argument(
       '-s', '--sdk-version',
       help='version of the sdk')
   parser.add_argument(
@@ -140,9 +145,8 @@ def main(argv):
   args = ParseArgs(argv)
 
   sdk_info = GetSDKInfoForCpu(
-      GetAppleCpuName(args.target_cpu),
-      args.sdk_version,
-      args.deployment_target)
+      GetAppleCpuName(args.target_cpu), args.target_environment,
+      args.sdk_version, args.deployment_target)
 
   if args.output == '-':
     sys.stdout.write(json.dumps(sdk_info))
diff --git a/gn/examples/ios/build/config/ios/sdk_info.gni b/gn/examples/ios/build/config/ios/sdk_info.gni
index 90b86310870..c8002533c4e 100644
--- a/gn/examples/ios/build/config/ios/sdk_info.gni
+++ b/gn/examples/ios/build/config/ios/sdk_info.gni
@@ -8,6 +8,8 @@ sdk_info = exec_script("//build/config/ios/scripts/sdk_info.py",
                        [
                          "--target-cpu",
                          current_cpu,
+                         "--target-environment",
+                         target_environment,
                          "--deployment-target",
                          ios_deployment_target,
                        ],
diff --git a/gn/examples/ios/build/config/ios/templates/ios_binary_bundle.gni b/gn/examples/ios/build/config/ios/templates/ios_binary_bundle.gni
index 1a3d6296321..43ec35593ec 100644
--- a/gn/examples/ios/build/config/ios/templates/ios_binary_bundle.gni
+++ b/gn/examples/ios/build/config/ios/templates/ios_binary_bundle.gni
@@ -117,5 +117,11 @@ template("ios_binary_bundle") {
     bundle_contents_dir = bundle_root_dir
     bundle_executable_dir = bundle_contents_dir
     bundle_resources_dir = bundle_contents_dir
+
+    xcode_extra_attributes = {
+      CODE_SIGN_IDENTITY = ""
+      CODE_SIGNING_REQUIRED = "NO"
+      CODE_SIGNING_ALLOWED = "NO"
+    }
   }
 }
diff --git a/gn/examples/ios/build/toolchain/ios/BUILD.gn b/gn/examples/ios/build/toolchain/ios/BUILD.gn
index 12d246b5c03..b7797200709 100644
--- a/gn/examples/ios/build/toolchain/ios/BUILD.gn
+++ b/gn/examples/ios/build/toolchain/ios/BUILD.gn
@@ -23,6 +23,8 @@ template("ios_toolchain") {
                             [
                               "--target-cpu",
                               current_cpu,
+                              "--target-environment",
+                              target_environment,
                               "--deployment-target",
                               ios_deployment_target,
                             ],
diff --git a/gn/infra/README.recipes.md b/gn/infra/README.recipes.md
index fabdf8542eb..0196775a6f6 100644
--- a/gn/infra/README.recipes.md
+++ b/gn/infra/README.recipes.md
@@ -3,21 +3,23 @@
 ## Table of Contents
 
 **[Recipe Modules](#Recipe-Modules)**
-  * [macos_sdk](#recipe_modules-macos_sdk) &mdash; The `macos_sdk` module provides safe functions to access a semi-hermetic XCode installation.
-  * [target](#recipe_modules-target)
-  * [windows_sdk](#recipe_modules-windows_sdk)
+  * [macos_sdk](#recipe_modules-macos_sdk) (Python3 ✅) &mdash; The `macos_sdk` module provides safe functions to access a semi-hermetic XCode installation.
+  * [target](#recipe_modules-target) (Python3 ✅)
+  * [windows_sdk](#recipe_modules-windows_sdk) (Python3 ✅)
 
 **[Recipes](#Recipes)**
-  * [gn](#recipes-gn) &mdash; Recipe for building GN.
-  * [macos_sdk:examples/full](#recipes-macos_sdk_examples_full)
-  * [target:examples/full](#recipes-target_examples_full)
-  * [windows_sdk:examples/full](#recipes-windows_sdk_examples_full)
+  * [gn](#recipes-gn) (Python3 ✅) &mdash; Recipe for building GN.
+  * [macos_sdk:examples/full](#recipes-macos_sdk_examples_full) (Python3 ✅)
+  * [target:examples/full](#recipes-target_examples_full) (Python3 ✅)
+  * [windows_sdk:examples/full](#recipes-windows_sdk_examples_full) (Python3 ✅)
 ## Recipe Modules
 
 ### *recipe_modules* / [macos\_sdk](/infra/recipe_modules/macos_sdk)
 
 [DEPS](/infra/recipe_modules/macos_sdk/__init__.py#5): [recipe\_engine/cipd][recipe_engine/recipe_modules/cipd], [recipe\_engine/context][recipe_engine/recipe_modules/context], [recipe\_engine/json][recipe_engine/recipe_modules/json], [recipe\_engine/path][recipe_engine/recipe_modules/path], [recipe\_engine/platform][recipe_engine/recipe_modules/platform], [recipe\_engine/step][recipe_engine/recipe_modules/step]
 
+PYTHON_VERSION_COMPATIBILITY: PY3
+
 The `macos_sdk` module provides safe functions to access a semi-hermetic
 XCode installation.
 
@@ -66,6 +68,8 @@ Raises:
 
 [DEPS](/infra/recipe_modules/target/__init__.py#5): [recipe\_engine/platform][recipe_engine/recipe_modules/platform]
 
+PYTHON_VERSION_COMPATIBILITY: PY3
+
 #### **class [TargetApi](/infra/recipe_modules/target/api.py#82)([RecipeApi][recipe_engine/wkt/RecipeApi]):**
 
 &emsp; **@property**<br>&mdash; **def [host](/infra/recipe_modules/target/api.py#87)(self):**
@@ -73,6 +77,8 @@ Raises:
 
 [DEPS](/infra/recipe_modules/windows_sdk/__init__.py#5): [recipe\_engine/cipd][recipe_engine/recipe_modules/cipd], [recipe\_engine/context][recipe_engine/recipe_modules/context], [recipe\_engine/json][recipe_engine/recipe_modules/json], [recipe\_engine/path][recipe_engine/recipe_modules/path], [recipe\_engine/platform][recipe_engine/recipe_modules/platform], [recipe\_engine/step][recipe_engine/recipe_modules/step]
 
+PYTHON_VERSION_COMPATIBILITY: PY3
+
 #### **class [WindowsSDKApi](/infra/recipe_modules/windows_sdk/api.py#10)([RecipeApi][recipe_engine/wkt/RecipeApi]):**
 
 API for using Windows SDK distributed via CIPD.
@@ -89,36 +95,44 @@ Raises:
 
 ### *recipes* / [gn](/infra/recipes/gn.py)
 
-[DEPS](/infra/recipes/gn.py#8): [macos\_sdk](#recipe_modules-macos_sdk), [target](#recipe_modules-target), [windows\_sdk](#recipe_modules-windows_sdk), [recipe\_engine/buildbucket][recipe_engine/recipe_modules/buildbucket], [recipe\_engine/cipd][recipe_engine/recipe_modules/cipd], [recipe\_engine/context][recipe_engine/recipe_modules/context], [recipe\_engine/file][recipe_engine/recipe_modules/file], [recipe\_engine/json][recipe_engine/recipe_modules/json], [recipe\_engine/path][recipe_engine/recipe_modules/path], [recipe\_engine/platform][recipe_engine/recipe_modules/platform], [recipe\_engine/properties][recipe_engine/recipe_modules/properties], [recipe\_engine/python][recipe_engine/recipe_modules/python], [recipe\_engine/raw\_io][recipe_engine/recipe_modules/raw_io], [recipe\_engine/step][recipe_engine/recipe_modules/step]
+[DEPS](/infra/recipes/gn.py#8): [macos\_sdk](#recipe_modules-macos_sdk), [target](#recipe_modules-target), [windows\_sdk](#recipe_modules-windows_sdk), [recipe\_engine/buildbucket][recipe_engine/recipe_modules/buildbucket], [recipe\_engine/cas][recipe_engine/recipe_modules/cas], [recipe\_engine/cipd][recipe_engine/recipe_modules/cipd], [recipe\_engine/context][recipe_engine/recipe_modules/context], [recipe\_engine/file][recipe_engine/recipe_modules/file], [recipe\_engine/json][recipe_engine/recipe_modules/json], [recipe\_engine/path][recipe_engine/recipe_modules/path], [recipe\_engine/platform][recipe_engine/recipe_modules/platform], [recipe\_engine/properties][recipe_engine/recipe_modules/properties], [recipe\_engine/raw\_io][recipe_engine/recipe_modules/raw_io], [recipe\_engine/step][recipe_engine/recipe_modules/step]
+
+PYTHON_VERSION_COMPATIBILITY: PY3
 
 Recipe for building GN.
 
-&mdash; **def [RunSteps](/infra/recipes/gn.py#102)(api, repository):**
+&mdash; **def [RunSteps](/infra/recipes/gn.py#103)(api, repository):**
 ### *recipes* / [macos\_sdk:examples/full](/infra/recipe_modules/macos_sdk/examples/full.py)
 
 [DEPS](/infra/recipe_modules/macos_sdk/examples/full.py#5): [macos\_sdk](#recipe_modules-macos_sdk), [recipe\_engine/platform][recipe_engine/recipe_modules/platform], [recipe\_engine/properties][recipe_engine/recipe_modules/properties], [recipe\_engine/step][recipe_engine/recipe_modules/step]
 
+PYTHON_VERSION_COMPATIBILITY: PY3
+
 &mdash; **def [RunSteps](/infra/recipe_modules/macos_sdk/examples/full.py#13)(api):**
 ### *recipes* / [target:examples/full](/infra/recipe_modules/target/examples/full.py)
 
 [DEPS](/infra/recipe_modules/target/examples/full.py#5): [target](#recipe_modules-target), [recipe\_engine/platform][recipe_engine/recipe_modules/platform], [recipe\_engine/properties][recipe_engine/recipe_modules/properties], [recipe\_engine/step][recipe_engine/recipe_modules/step]
 
+PYTHON_VERSION_COMPATIBILITY: PY3
+
 &mdash; **def [RunSteps](/infra/recipe_modules/target/examples/full.py#13)(api):**
 ### *recipes* / [windows\_sdk:examples/full](/infra/recipe_modules/windows_sdk/examples/full.py)
 
 [DEPS](/infra/recipe_modules/windows_sdk/examples/full.py#5): [windows\_sdk](#recipe_modules-windows_sdk), [recipe\_engine/platform][recipe_engine/recipe_modules/platform], [recipe\_engine/properties][recipe_engine/recipe_modules/properties], [recipe\_engine/step][recipe_engine/recipe_modules/step]
 
+PYTHON_VERSION_COMPATIBILITY: PY3
+
 &mdash; **def [RunSteps](/infra/recipe_modules/windows_sdk/examples/full.py#13)(api):**
 
-[recipe_engine/recipe_modules/buildbucket]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/d31ba13ede8c21e60116ae61e4490d53ba77fcbd/README.recipes.md#recipe_modules-buildbucket
-[recipe_engine/recipe_modules/cipd]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/d31ba13ede8c21e60116ae61e4490d53ba77fcbd/README.recipes.md#recipe_modules-cipd
-[recipe_engine/recipe_modules/context]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/d31ba13ede8c21e60116ae61e4490d53ba77fcbd/README.recipes.md#recipe_modules-context
-[recipe_engine/recipe_modules/file]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/d31ba13ede8c21e60116ae61e4490d53ba77fcbd/README.recipes.md#recipe_modules-file
-[recipe_engine/recipe_modules/json]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/d31ba13ede8c21e60116ae61e4490d53ba77fcbd/README.recipes.md#recipe_modules-json
-[recipe_engine/recipe_modules/path]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/d31ba13ede8c21e60116ae61e4490d53ba77fcbd/README.recipes.md#recipe_modules-path
-[recipe_engine/recipe_modules/platform]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/d31ba13ede8c21e60116ae61e4490d53ba77fcbd/README.recipes.md#recipe_modules-platform
-[recipe_engine/recipe_modules/properties]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/d31ba13ede8c21e60116ae61e4490d53ba77fcbd/README.recipes.md#recipe_modules-properties
-[recipe_engine/recipe_modules/python]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/d31ba13ede8c21e60116ae61e4490d53ba77fcbd/README.recipes.md#recipe_modules-python
-[recipe_engine/recipe_modules/raw_io]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/d31ba13ede8c21e60116ae61e4490d53ba77fcbd/README.recipes.md#recipe_modules-raw_io
-[recipe_engine/recipe_modules/step]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/d31ba13ede8c21e60116ae61e4490d53ba77fcbd/README.recipes.md#recipe_modules-step
-[recipe_engine/wkt/RecipeApi]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/d31ba13ede8c21e60116ae61e4490d53ba77fcbd/recipe_engine/recipe_api.py#856
+[recipe_engine/recipe_modules/buildbucket]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/ff5ce51ceaaa7a62275bb766831a3ce1e88de37d/README.recipes.md#recipe_modules-buildbucket
+[recipe_engine/recipe_modules/cas]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/ff5ce51ceaaa7a62275bb766831a3ce1e88de37d/README.recipes.md#recipe_modules-cas
+[recipe_engine/recipe_modules/cipd]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/ff5ce51ceaaa7a62275bb766831a3ce1e88de37d/README.recipes.md#recipe_modules-cipd
+[recipe_engine/recipe_modules/context]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/ff5ce51ceaaa7a62275bb766831a3ce1e88de37d/README.recipes.md#recipe_modules-context
+[recipe_engine/recipe_modules/file]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/ff5ce51ceaaa7a62275bb766831a3ce1e88de37d/README.recipes.md#recipe_modules-file
+[recipe_engine/recipe_modules/json]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/ff5ce51ceaaa7a62275bb766831a3ce1e88de37d/README.recipes.md#recipe_modules-json
+[recipe_engine/recipe_modules/path]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/ff5ce51ceaaa7a62275bb766831a3ce1e88de37d/README.recipes.md#recipe_modules-path
+[recipe_engine/recipe_modules/platform]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/ff5ce51ceaaa7a62275bb766831a3ce1e88de37d/README.recipes.md#recipe_modules-platform
+[recipe_engine/recipe_modules/properties]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/ff5ce51ceaaa7a62275bb766831a3ce1e88de37d/README.recipes.md#recipe_modules-properties
+[recipe_engine/recipe_modules/raw_io]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/ff5ce51ceaaa7a62275bb766831a3ce1e88de37d/README.recipes.md#recipe_modules-raw_io
+[recipe_engine/recipe_modules/step]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/ff5ce51ceaaa7a62275bb766831a3ce1e88de37d/README.recipes.md#recipe_modules-step
+[recipe_engine/wkt/RecipeApi]: https://chromium.googlesource.com/infra/luci/recipes-py.git/+/ff5ce51ceaaa7a62275bb766831a3ce1e88de37d/recipe_engine/recipe_api.py#886
diff --git a/gn/infra/config/generated/cr-buildbucket.cfg b/gn/infra/config/generated/cr-buildbucket.cfg
index fdfd16caf43..9815e2bfea0 100644
--- a/gn/infra/config/generated/cr-buildbucket.cfg
+++ b/gn/infra/config/generated/cr-buildbucket.cfg
@@ -14,7 +14,7 @@ buckets {
       name: "linux"
       swarming_host: "chromium-swarm.appspot.com"
       dimensions: "cpu:x86-64"
-      dimensions: "os:Ubuntu-16.04"
+      dimensions: "os:Ubuntu-18.04"
       dimensions: "pool:luci.flex.ci"
       recipe {
         name: "gn"
@@ -24,7 +24,7 @@ buckets {
       execution_timeout_secs: 3600
       service_account: "gn-ci-builder@chops-service-accounts.iam.gserviceaccount.com"
       experiments {
-        key: "luci.use_realms"
+        key: "luci.recipes.use_python3"
         value: 100
       }
     }
@@ -46,7 +46,7 @@ buckets {
       }
       service_account: "gn-ci-builder@chops-service-accounts.iam.gserviceaccount.com"
       experiments {
-        key: "luci.use_realms"
+        key: "luci.recipes.use_python3"
         value: 100
       }
     }
@@ -68,7 +68,7 @@ buckets {
       }
       service_account: "gn-ci-builder@chops-service-accounts.iam.gserviceaccount.com"
       experiments {
-        key: "luci.use_realms"
+        key: "luci.recipes.use_python3"
         value: 100
       }
     }
@@ -92,7 +92,7 @@ buckets {
       name: "linux"
       swarming_host: "chromium-swarm.appspot.com"
       dimensions: "cpu:x86-64"
-      dimensions: "os:Ubuntu-16.04"
+      dimensions: "os:Ubuntu-18.04"
       dimensions: "pool:luci.flex.try"
       recipe {
         name: "gn"
@@ -102,7 +102,7 @@ buckets {
       execution_timeout_secs: 3600
       service_account: "gn-try-builder@chops-service-accounts.iam.gserviceaccount.com"
       experiments {
-        key: "luci.use_realms"
+        key: "luci.recipes.use_python3"
         value: 100
       }
     }
@@ -124,7 +124,7 @@ buckets {
       }
       service_account: "gn-try-builder@chops-service-accounts.iam.gserviceaccount.com"
       experiments {
-        key: "luci.use_realms"
+        key: "luci.recipes.use_python3"
         value: 100
       }
     }
@@ -146,7 +146,7 @@ buckets {
       }
       service_account: "gn-try-builder@chops-service-accounts.iam.gserviceaccount.com"
       experiments {
-        key: "luci.use_realms"
+        key: "luci.recipes.use_python3"
         value: 100
       }
     }
diff --git a/gn/infra/config/generated/luci-scheduler.cfg b/gn/infra/config/generated/luci-scheduler.cfg
index 1ba26bf74ad..a3ff24d7fce 100644
--- a/gn/infra/config/generated/luci-scheduler.cfg
+++ b/gn/infra/config/generated/luci-scheduler.cfg
@@ -10,7 +10,7 @@ job {
   acl_sets: "ci"
   buildbucket {
     server: "cr-buildbucket.appspot.com"
-    bucket: "luci.gn.ci"
+    bucket: "ci"
     builder: "linux"
   }
 }
@@ -20,7 +20,7 @@ job {
   acl_sets: "ci"
   buildbucket {
     server: "cr-buildbucket.appspot.com"
-    bucket: "luci.gn.ci"
+    bucket: "ci"
     builder: "mac"
   }
 }
@@ -30,7 +30,7 @@ job {
   acl_sets: "ci"
   buildbucket {
     server: "cr-buildbucket.appspot.com"
-    bucket: "luci.gn.ci"
+    bucket: "ci"
     builder: "win"
   }
 }
diff --git a/gn/infra/config/generated/project.cfg b/gn/infra/config/generated/project.cfg
index 0ac69510b6f..764450f818e 100644
--- a/gn/infra/config/generated/project.cfg
+++ b/gn/infra/config/generated/project.cfg
@@ -6,3 +6,10 @@
 
 name: "gn"
 access: "group:all"
+lucicfg {
+  version: "1.30.11"
+  package_dir: ".."
+  config_dir: "generated"
+  entry_point: "main.star"
+  experiments: "crbug.com/1182002"
+}
diff --git a/gn/infra/config/generated/realms.cfg b/gn/infra/config/generated/realms.cfg
index ed90980b030..54791e928d7 100644
--- a/gn/infra/config/generated/realms.cfg
+++ b/gn/infra/config/generated/realms.cfg
@@ -49,4 +49,8 @@ realms {
     principals: "group:project-gn-tryjob-access"
     principals: "group:service-account-cq"
   }
+  bindings {
+    role: "role/swarming.taskTriggerer"
+    principals: "group:flex-try-led-users"
+  }
 }
diff --git a/gn/infra/config/main.star b/gn/infra/config/main.star
index 2762024af3f..135796771ba 100755
--- a/gn/infra/config/main.star
+++ b/gn/infra/config/main.star
@@ -1,10 +1,9 @@
 #!/usr/bin/env lucicfg
 
-lucicfg.check_version("1.23.3", "Please update depot_tools")
+lucicfg.check_version("1.30.9", "Please update depot_tools")
 
-# Enable LUCI Realms support and launch all builds in realms-aware mode.
-lucicfg.enable_experiment("crbug.com/1085650")
-luci.builder.defaults.experiments.set({"luci.use_realms": 100})
+# Use LUCI Scheduler BBv2 names and add Scheduler realms configs.
+lucicfg.enable_experiment("crbug.com/1182002")
 
 lucicfg.config(
     config_dir = "generated",
@@ -56,6 +55,9 @@ def builder(name, bucket, os, caches = None, triggered_by = None):
         execution_timeout = 1 * time.hour,
         dimensions = {"cpu": "x86-64", "os": os, "pool": "luci.flex.%s" % bucket},
         triggered_by = triggered_by,
+        experiments = {
+            "luci.recipes.use_python3": 100,
+        },
     )
 
 luci.logdog(
@@ -95,7 +97,7 @@ def ci_builder(name, os, caches = None):
         short_name = name,
     )
 
-ci_builder("linux", "Ubuntu-16.04")
+ci_builder("linux", "Ubuntu-18.04")
 ci_builder("mac", "Mac-10.15", caches = [swarming.cache("macos_sdk")])
 ci_builder("win", "Windows-10", caches = [swarming.cache("windows_sdk")])
 
@@ -136,6 +138,12 @@ luci.bucket(name = "try", acls = [
     ),
 ])
 
+luci.binding(
+    realm = "try",
+    roles = "role/swarming.taskTriggerer",
+    groups = "flex-try-led-users",
+)
+
 def try_builder(name, os, caches = None):
     builder(name, "try", os, caches)
     luci.cq_tryjob_verifier(
@@ -143,6 +151,6 @@ def try_builder(name, os, caches = None):
         cq_group = "gn",
     )
 
-try_builder("linux", "Ubuntu-16.04")
+try_builder("linux", "Ubuntu-18.04")
 try_builder("mac", "Mac-10.15", caches = [swarming.cache("macos_sdk")])
 try_builder("win", "Windows-10", caches = [swarming.cache("windows_sdk")])
diff --git a/gn/infra/config/recipes.cfg b/gn/infra/config/recipes.cfg
index 45963824ce8..da25624866f 100644
--- a/gn/infra/config/recipes.cfg
+++ b/gn/infra/config/recipes.cfg
@@ -2,11 +2,12 @@
   "api_version": 2,
   "deps": {
     "recipe_engine": {
-      "branch": "main",
-      "revision": "d31ba13ede8c21e60116ae61e4490d53ba77fcbd",
+      "branch": "refs/heads/main",
+      "revision": "ff5ce51ceaaa7a62275bb766831a3ce1e88de37d",
       "url": "https://chromium.googlesource.com/infra/luci/recipes-py"
     }
   },
   "project_id": "gn",
+  "py3_only": true,
   "recipes_path": "infra"
 }
diff --git a/gn/infra/recipe_modules/windows_sdk/examples/full.expected/win.json b/gn/infra/recipe_modules/windows_sdk/examples/full.expected/win.json
index f6c937f8812..f45cd832c0a 100644
--- a/gn/infra/recipe_modules/windows_sdk/examples/full.expected/win.json
+++ b/gn/infra/recipe_modules/windows_sdk/examples/full.expected/win.json
@@ -30,9 +30,9 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
-      "\nimport shutil\nimport sys\nshutil.copy(sys.argv[1], sys.argv[2])\n",
+      "RECIPE_MODULE[recipe_engine::json]\\resources\\read.py",
       "[CACHE]\\windows_sdk\\win_sdk\\bin\\SetEnv.x64.json",
       "/path/to/tmp/json"
     ],
diff --git a/gn/infra/recipes.py b/gn/infra/recipes.py
index 2fe00862255..7c534c224c3 100755
--- a/gn/infra/recipes.py
+++ b/gn/infra/recipes.py
@@ -1,47 +1,59 @@
-#!/usr/bin/env python
-
-# Copyright 2017 The LUCI Authors. All rights reserved.
+#!/bin/sh
+# Copyright 2019 The LUCI Authors. All rights reserved.
 # Use of this source code is governed under the Apache License, Version 2.0
 # that can be found in the LICENSE file.
 
+# We want to run python in unbuffered mode; however shebangs on linux grab the
+# entire rest of the shebang line as a single argument, leading to errors like:
+#
+#   /usr/bin/env: 'python3 -u': No such file or directory
+#
+# This little shell hack is a triple-quoted noop in python, but in sh it
+# evaluates to re-exec'ing this script in unbuffered mode.
+# pylint: disable=pointless-string-statement
+''''exec python3 -u -- "$0" ${1+"$@"} # '''
+# vi: syntax=python
 """Bootstrap script to clone and forward to the recipe engine tool.
 
 *******************
 ** DO NOT MODIFY **
 *******************
 
-This is a copy of https://chromium.googlesource.com/infra/luci/recipes-py/+/master/recipes.py.
+This is a copy of https://chromium.googlesource.com/infra/luci/recipes-py/+/main/recipes.py.
 To fix bugs, fix in the googlesource repo then run the autoroller.
 """
 
+# pylint: disable=wrong-import-position
 import argparse
+import errno
 import json
 import logging
 import os
-import random
 import subprocess
 import sys
-import time
-import urlparse
 
 from collections import namedtuple
+from io import open  # pylint: disable=redefined-builtin
 
-from cStringIO import StringIO
+try:
+  import urllib.parse as urlparse
+except ImportError:
+  import urlparse
 
 # The dependency entry for the recipe_engine in the client repo's recipes.cfg
 #
 # url (str) - the url to the engine repo we want to use.
 # revision (str) - the git revision for the engine to get.
 # branch (str) - the branch to fetch for the engine as an absolute ref (e.g.
-#   refs/heads/master)
-EngineDep = namedtuple('EngineDep',
-                       'url revision branch')
+#   refs/heads/main)
+EngineDep = namedtuple('EngineDep', 'url revision branch')
 
 
 class MalformedRecipesCfg(Exception):
+
   def __init__(self, msg, path):
-    super(MalformedRecipesCfg, self).__init__('malformed recipes.cfg: %s: %r'
-                                              % (msg, path))
+    full_message = 'malformed recipes.cfg: %s: %r' % (msg, path)
+    super(MalformedRecipesCfg, self).__init__(full_message)
 
 
 def parse(repo_root, recipes_cfg_path):
@@ -58,9 +70,12 @@ def parse(repo_root, recipes_cfg_path):
     recipes_path (str) - native path to where the recipes live inside of the
       current repo (i.e. the folder containing `recipes/` and/or
       `recipe_modules`)
+    py3_only (bool) - True if this repo has been marked as ONLY supporting
+      python3.
   """
-  with open(recipes_cfg_path, 'rU') as fh:
+  with open(recipes_cfg_path, 'r') as fh:
     pb = json.load(fh)
+  py3_only = pb.get('py3_only', False)
 
   try:
     if pb['api_version'] != 2:
@@ -73,40 +88,42 @@ def parse(repo_root, recipes_cfg_path):
     if not repo_name:
       repo_name = pb['project_id']
     if repo_name == 'recipe_engine':
-      return None, pb.get('recipes_path', '')
+      return None, pb.get('recipes_path', ''), py3_only
 
     engine = pb['deps']['recipe_engine']
 
     if 'url' not in engine:
       raise MalformedRecipesCfg(
-        'Required field "url" in dependency "recipe_engine" not found',
-        recipes_cfg_path)
+          'Required field "url" in dependency "recipe_engine" not found',
+          recipes_cfg_path)
 
     engine.setdefault('revision', '')
-    engine.setdefault('branch', 'refs/heads/master')
+    engine.setdefault('branch', 'refs/heads/main')
     recipes_path = pb.get('recipes_path', '')
 
     # TODO(iannucci): only support absolute refs
     if not engine['branch'].startswith('refs/'):
       engine['branch'] = 'refs/heads/' + engine['branch']
 
-    recipes_path = os.path.join(
-      repo_root, recipes_path.replace('/', os.path.sep))
-    return EngineDep(**engine), recipes_path
+    recipes_path = os.path.join(repo_root,
+                                recipes_path.replace('/', os.path.sep))
+    return EngineDep(**engine), recipes_path, py3_only
   except KeyError as ex:
-    raise MalformedRecipesCfg(ex.message, recipes_cfg_path)
+    raise MalformedRecipesCfg(str(ex), recipes_cfg_path)
 
 
-_BAT = '.bat' if sys.platform.startswith(('win', 'cygwin')) else ''
+IS_WIN = sys.platform.startswith(('win', 'cygwin'))
+
+_BAT = '.bat' if IS_WIN else ''
 GIT = 'git' + _BAT
-VPYTHON = 'vpython' + _BAT
 CIPD = 'cipd' + _BAT
-REQUIRED_BINARIES = {GIT, VPYTHON, CIPD}
+REQUIRED_BINARIES = {GIT, CIPD}
 
 
 def _is_executable(path):
   return os.path.isfile(path) and os.access(path, os.X_OK)
 
+
 # TODO: Use shutil.which once we switch to Python3.
 def _is_on_path(basename):
   for path in os.environ['PATH'].split(os.pathsep):
@@ -122,13 +139,13 @@ def _subprocess_call(argv, **kwargs):
 
 
 def _git_check_call(argv, **kwargs):
-  argv = [GIT]+argv
+  argv = [GIT] + argv
   logging.info('Running %r', argv)
   subprocess.check_call(argv, **kwargs)
 
 
 def _git_output(argv, **kwargs):
-  argv = [GIT]+argv
+  argv = [GIT] + argv
   logging.info('Running %r', argv)
   return subprocess.check_output(argv, **kwargs)
 
@@ -152,10 +169,14 @@ def parse_args(argv):
 
 
 def checkout_engine(engine_path, repo_root, recipes_cfg_path):
-  dep, recipes_path = parse(repo_root, recipes_cfg_path)
+  """Checks out the recipe_engine repo pinned in recipes.cfg.
+
+  Returns the path to the recipe engine repo and the py3_only boolean.
+  """
+  dep, recipes_path, py3_only = parse(repo_root, recipes_cfg_path)
   if dep is None:
     # we're running from the engine repo already!
-    return os.path.join(repo_root, recipes_path)
+    return os.path.join(repo_root, recipes_path), py3_only
 
   url = dep.url
 
@@ -174,22 +195,33 @@ def checkout_engine(engine_path, repo_root, recipes_cfg_path):
       _git_check_call(['init', engine_path], stdout=NUL)
 
       try:
-        _git_check_call(['rev-parse', '--verify', '%s^{commit}' % revision],
-                        cwd=engine_path, stdout=NUL, stderr=NUL)
-      except subprocess.CalledProcessError:
-        _git_check_call(['fetch', url, branch], cwd=engine_path, stdout=NUL,
+        _git_check_call(['rev-parse', '--verify',
+                         '%s^{commit}' % revision],
+                        cwd=engine_path,
+                        stdout=NUL,
                         stderr=NUL)
+      except subprocess.CalledProcessError:
+        _git_check_call(['fetch', '--quiet', url, branch],
+                        cwd=engine_path,
+                        stdout=NUL)
 
     try:
       _git_check_call(['diff', '--quiet', revision], cwd=engine_path)
     except subprocess.CalledProcessError:
+      index_lock = os.path.join(engine_path, '.git', 'index.lock')
+      try:
+        os.remove(index_lock)
+      except OSError as exc:
+        if exc.errno != errno.ENOENT:
+          logging.warn('failed to remove %r, reset will fail: %s', index_lock,
+                       exc)
       _git_check_call(['reset', '-q', '--hard', revision], cwd=engine_path)
 
     # If the engine has refactored/moved modules we need to clean all .pyc files
     # or things will get squirrely.
     _git_check_call(['clean', '-qxf'], cwd=engine_path)
 
-  return engine_path
+  return engine_path, py3_only
 
 
 def main():
@@ -206,22 +238,36 @@ def main():
   if recipes_cfg_path:
     # calculate repo_root from recipes_cfg_path
     repo_root = os.path.dirname(
-      os.path.dirname(
-        os.path.dirname(recipes_cfg_path)))
+        os.path.dirname(os.path.dirname(recipes_cfg_path)))
   else:
     # find repo_root with git and calculate recipes_cfg_path
-    repo_root = (_git_output(
-      ['rev-parse', '--show-toplevel'],
-      cwd=os.path.abspath(os.path.dirname(__file__))).strip())
-    repo_root = os.path.abspath(repo_root)
+    repo_root = (
+        _git_output(['rev-parse', '--show-toplevel'],
+                    cwd=os.path.abspath(os.path.dirname(__file__))).strip())
+    repo_root = os.path.abspath(repo_root).decode()
     recipes_cfg_path = os.path.join(repo_root, 'infra', 'config', 'recipes.cfg')
     args = ['--package', recipes_cfg_path] + args
-
-  engine_path = checkout_engine(engine_override, repo_root, recipes_cfg_path)
-
-  return _subprocess_call([
-      VPYTHON, '-u',
-      os.path.join(engine_path, 'recipe_engine', 'main.py')] + args)
+  engine_path, py3_only = checkout_engine(engine_override, repo_root, recipes_cfg_path)
+
+  using_py3 = py3_only or os.getenv('RECIPES_USE_PY3') == 'true'
+  vpython = ('vpython' + ('3' if using_py3 else '') + _BAT)
+  if not _is_on_path(vpython):
+    return 'Required binary is not found on PATH: %s' % vpython
+
+  argv = ([
+    vpython, '-u', os.path.join(engine_path, 'recipe_engine', 'main.py'),
+  ] + args)
+
+  if IS_WIN:
+    # No real 'exec' on windows; set these signals to ignore so that they
+    # propagate to our children but we still wait for the child process to quit.
+    import signal
+    signal.signal(signal.SIGBREAK, signal.SIG_IGN)
+    signal.signal(signal.SIGINT, signal.SIG_IGN)
+    signal.signal(signal.SIGTERM, signal.SIG_IGN)
+    return _subprocess_call(argv)
+  else:
+    os.execvp(argv[0], argv)
 
 
 if __name__ == '__main__':
diff --git a/gn/infra/recipes/gn.expected/ci_linux.json b/gn/infra/recipes/gn.expected/ci_linux.json
index 128c0e6e038..27e7b3f09f2 100644
--- a/gn/infra/recipes/gn.expected/ci_linux.json
+++ b/gn/infra/recipes/gn.expected/ci_linux.json
@@ -10,6 +10,18 @@
       "[START_DIR]/gn"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.init",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -25,6 +37,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.fetch",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -38,6 +62,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.checkout",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -51,6 +87,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.rev-parse",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -70,6 +118,18 @@
       "/path/to/tmp/json"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "ensure_installed",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -105,6 +165,18 @@
       "init",
       "[START_DIR]/rpmalloc"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.init",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -116,10 +188,22 @@
       "fetch",
       "--tags",
       "https://fuchsia.googlesource.com/third_party/github.com/mjansson/rpmalloc",
-      "f4b7c52c858675f732a76bd1c73447e0fcf84b1e"
+      "+upstream/develop"
     ],
     "cwd": "[START_DIR]/rpmalloc",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.fetch",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -129,16 +213,90 @@
     "cmd": [
       "git",
       "checkout",
-      "FETCH_HEAD"
+      "668a7f81b588a985c6528b70674dbcc005d9cb75"
     ],
     "cwd": "[START_DIR]/rpmalloc",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.checkout",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
     ]
   },
   {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "copy",
+      "[START_DIR]/rpmalloc/build/ninja/clang.py",
+      "/path/to/tmp/"
+    ],
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "rpmalloc.read [START_DIR]/rpmalloc/build/ninja/clang.py",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_LOG_LINE@clang.py@CXXFLAGS = ['-Wall', '-Weverything', '-Wfoo']@@@",
+      "@@@STEP_LOG_END@clang.py@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "copy",
+      "CXXFLAGS = ['-Wall', '-Weverything', '-Wfoo']",
+      "[START_DIR]/rpmalloc/build/ninja/clang.py"
+    ],
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "rpmalloc.write [START_DIR]/rpmalloc/build/ninja/clang.py",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_LOG_LINE@clang.py@CXXFLAGS = ['-Wall', '-Weverything', '-Wfoo']@@@",
+      "@@@STEP_LOG_END@clang.py@@@"
+    ]
+  },
+  {
     "cmd": [],
     "name": "rpmalloc.build rpmalloc-linux-amd64",
     "~followup_annotations": [
@@ -147,7 +305,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/rpmalloc/configure.py",
       "-c",
@@ -164,6 +322,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-amd64.configure",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -182,6 +352,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-amd64.ninja",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -196,7 +378,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/rpmalloc/configure.py",
       "-c",
@@ -213,6 +395,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-arm64.configure",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -231,6 +425,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-arm64.ninja",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -249,7 +455,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "-d"
@@ -262,6 +468,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.linux-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -281,6 +499,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.linux-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -298,6 +528,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.linux-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -316,7 +558,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "--use-lto",
@@ -331,6 +573,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -350,6 +604,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -367,6 +633,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -400,6 +678,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.upload.build gn/gn/linux-amd64",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@3@@@",
@@ -421,7 +711,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "--use-lto",
@@ -436,6 +726,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-arm64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -455,6 +757,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-arm64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -488,6 +802,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-arm64.upload.build gn/gn/linux-arm64",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@3@@@",
diff --git a/gn/infra/recipes/gn.expected/ci_mac.json b/gn/infra/recipes/gn.expected/ci_mac.json
index 90114aded03..66274f850b0 100644
--- a/gn/infra/recipes/gn.expected/ci_mac.json
+++ b/gn/infra/recipes/gn.expected/ci_mac.json
@@ -10,6 +10,18 @@
       "[START_DIR]/gn"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.init",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -25,6 +37,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.fetch",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -38,6 +62,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.checkout",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -51,6 +87,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.rev-parse",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -70,6 +118,18 @@
       "/path/to/tmp/json"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "ensure_installed",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -103,6 +163,18 @@
       "/path/to/tmp/json"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "ensure_installed (2)",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -130,6 +202,18 @@
       "[CACHE]/macos_sdk/XCode.app"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "install xcode"
   },
   {
@@ -140,6 +224,18 @@
       "[CACHE]/macos_sdk/XCode.app"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "select XCode"
   },
   {
@@ -151,11 +247,23 @@
       "xcrun",
       "--show-sdk-path"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.xcrun sdk-path",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_LOG_LINE@raw_io.output[sdk-path]@/some/xcode/path@@@",
-      "@@@STEP_LOG_END@raw_io.output[sdk-path]@@@"
+      "@@@STEP_LOG_LINE@raw_io.output_text[sdk-path]@/some/xcode/path@@@",
+      "@@@STEP_LOG_END@raw_io.output_text[sdk-path]@@@"
     ]
   },
   {
@@ -167,13 +275,25 @@
       "-xc++",
       "-fsyntax-only",
       "-Wp,-v",
-      "-"
+      "/dev/null"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.xcrun toolchain",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_LOG_LINE@raw_io.output[toolchain]@[CACHE]/macos_sdk/XCode.app/include/c++/v1@@@",
-      "@@@STEP_LOG_END@raw_io.output[toolchain]@@@"
+      "@@@STEP_LOG_LINE@raw_io.output_text[toolchain]@[CACHE]/macos_sdk/XCode.app/include/c++/v1@@@",
+      "@@@STEP_LOG_END@raw_io.output_text[toolchain]@@@"
     ]
   },
   {
@@ -185,7 +305,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "-d"
@@ -198,6 +318,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.mac-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -217,6 +349,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.mac-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -234,6 +378,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.mac-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -248,11 +404,23 @@
       "xcrun",
       "--show-sdk-path"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.xcrun sdk-path",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_LOG_LINE@raw_io.output[sdk-path]@/some/xcode/path@@@",
-      "@@@STEP_LOG_END@raw_io.output[sdk-path]@@@"
+      "@@@STEP_LOG_LINE@raw_io.output_text[sdk-path]@/some/xcode/path@@@",
+      "@@@STEP_LOG_END@raw_io.output_text[sdk-path]@@@"
     ]
   },
   {
@@ -264,13 +432,25 @@
       "-xc++",
       "-fsyntax-only",
       "-Wp,-v",
-      "-"
+      "/dev/null"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.xcrun toolchain",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_LOG_LINE@raw_io.output[toolchain]@[CACHE]/macos_sdk/XCode.app/include/c++/v1@@@",
-      "@@@STEP_LOG_END@raw_io.output[toolchain]@@@"
+      "@@@STEP_LOG_LINE@raw_io.output_text[toolchain]@[CACHE]/macos_sdk/XCode.app/include/c++/v1@@@",
+      "@@@STEP_LOG_END@raw_io.output_text[toolchain]@@@"
     ]
   },
   {
@@ -282,7 +462,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "--use-lto",
@@ -296,6 +476,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.mac-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -315,6 +507,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.mac-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -332,6 +536,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.mac-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -365,6 +581,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.mac-amd64.upload.build gn/gn/mac-amd64",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@3@@@",
@@ -382,11 +610,23 @@
       "xcrun",
       "--show-sdk-path"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.xcrun sdk-path (2)",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_LOG_LINE@raw_io.output[sdk-path]@/some/xcode/path@@@",
-      "@@@STEP_LOG_END@raw_io.output[sdk-path]@@@"
+      "@@@STEP_LOG_LINE@raw_io.output_text[sdk-path]@/some/xcode/path@@@",
+      "@@@STEP_LOG_END@raw_io.output_text[sdk-path]@@@"
     ]
   },
   {
@@ -398,13 +638,25 @@
       "-xc++",
       "-fsyntax-only",
       "-Wp,-v",
-      "-"
+      "/dev/null"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.xcrun toolchain (2)",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_LOG_LINE@raw_io.output[toolchain]@[CACHE]/macos_sdk/XCode.app/include/c++/v1@@@",
-      "@@@STEP_LOG_END@raw_io.output[toolchain]@@@"
+      "@@@STEP_LOG_LINE@raw_io.output_text[toolchain]@[CACHE]/macos_sdk/XCode.app/include/c++/v1@@@",
+      "@@@STEP_LOG_END@raw_io.output_text[toolchain]@@@"
     ]
   },
   {
@@ -416,7 +668,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "--use-lto",
@@ -430,6 +682,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=arm64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.mac-arm64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -449,6 +713,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=arm64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.mac-arm64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -482,6 +758,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=arm64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.mac-arm64.upload.build gn/gn/mac-arm64",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@3@@@",
@@ -501,6 +789,18 @@
       "--reset"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "reset XCode"
   },
   {
diff --git a/gn/infra/recipes/gn.expected/ci_win.json b/gn/infra/recipes/gn.expected/ci_win.json
index fcdc6582ecc..11534b5ab8e 100644
--- a/gn/infra/recipes/gn.expected/ci_win.json
+++ b/gn/infra/recipes/gn.expected/ci_win.json
@@ -10,6 +10,18 @@
       "[START_DIR]\\gn"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.init",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -25,6 +37,18 @@
     ],
     "cwd": "[START_DIR]\\gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.fetch",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -38,6 +62,18 @@
     ],
     "cwd": "[START_DIR]\\gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.checkout",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -51,6 +87,18 @@
     ],
     "cwd": "[START_DIR]\\gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.rev-parse",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -70,6 +118,18 @@
       "/path/to/tmp/json"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "ensure_installed",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -99,6 +159,18 @@
       "/path/to/tmp/json"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "ensure_installed (2)",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -116,12 +188,24 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
-      "\nimport shutil\nimport sys\nshutil.copy(sys.argv[1], sys.argv[2])\n",
+      "RECIPE_MODULE[recipe_engine::json]\\resources\\read.py",
       "[CACHE]\\windows_sdk\\win_sdk\\bin\\SetEnv.x64.json",
       "/path/to/tmp/json"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "read SetEnv.x64.json",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -159,7 +243,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]\\gn\\build\\gen.py",
       "-d"
@@ -173,6 +257,18 @@
         "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
       ]
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.windows-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -193,6 +289,18 @@
         "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
       ]
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.windows-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -211,6 +319,18 @@
         "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
       ]
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.windows-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -229,7 +349,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]\\gn\\build\\gen.py",
       "--use-lto",
@@ -244,6 +364,18 @@
         "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
       ]
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.windows-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -264,6 +396,18 @@
         "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
       ]
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.windows-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -282,6 +426,18 @@
         "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
       ]
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.windows-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -316,6 +472,18 @@
         "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
       ]
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.windows-amd64.upload.build gn/gn/windows-amd64",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@3@@@",
@@ -336,6 +504,18 @@
       "/im",
       "mspdbsrv.exe"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "taskkill mspdbsrv"
   },
   {
diff --git a/gn/infra/recipes/gn.expected/cipd_exists.json b/gn/infra/recipes/gn.expected/cipd_exists.json
index 9d2811dd338..64c1fb5409e 100644
--- a/gn/infra/recipes/gn.expected/cipd_exists.json
+++ b/gn/infra/recipes/gn.expected/cipd_exists.json
@@ -10,6 +10,18 @@
       "[START_DIR]/gn"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.init",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -25,6 +37,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.fetch",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -38,6 +62,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.checkout",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -51,6 +87,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.rev-parse",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -70,6 +118,18 @@
       "/path/to/tmp/json"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "ensure_installed",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -105,6 +165,18 @@
       "init",
       "[START_DIR]/rpmalloc"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.init",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -116,10 +188,22 @@
       "fetch",
       "--tags",
       "https://fuchsia.googlesource.com/third_party/github.com/mjansson/rpmalloc",
-      "f4b7c52c858675f732a76bd1c73447e0fcf84b1e"
+      "+upstream/develop"
     ],
     "cwd": "[START_DIR]/rpmalloc",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.fetch",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -129,16 +213,90 @@
     "cmd": [
       "git",
       "checkout",
-      "FETCH_HEAD"
+      "668a7f81b588a985c6528b70674dbcc005d9cb75"
     ],
     "cwd": "[START_DIR]/rpmalloc",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.checkout",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
     ]
   },
   {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "copy",
+      "[START_DIR]/rpmalloc/build/ninja/clang.py",
+      "/path/to/tmp/"
+    ],
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "rpmalloc.read [START_DIR]/rpmalloc/build/ninja/clang.py",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_LOG_LINE@clang.py@CXXFLAGS = ['-Wall', '-Weverything', '-Wfoo']@@@",
+      "@@@STEP_LOG_END@clang.py@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "copy",
+      "CXXFLAGS = ['-Wall', '-Weverything', '-Wfoo']",
+      "[START_DIR]/rpmalloc/build/ninja/clang.py"
+    ],
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "rpmalloc.write [START_DIR]/rpmalloc/build/ninja/clang.py",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_LOG_LINE@clang.py@CXXFLAGS = ['-Wall', '-Weverything', '-Wfoo']@@@",
+      "@@@STEP_LOG_END@clang.py@@@"
+    ]
+  },
+  {
     "cmd": [],
     "name": "rpmalloc.build rpmalloc-linux-amd64",
     "~followup_annotations": [
@@ -147,7 +305,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/rpmalloc/configure.py",
       "-c",
@@ -164,6 +322,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-amd64.configure",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -182,6 +352,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-amd64.ninja",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -196,7 +378,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/rpmalloc/configure.py",
       "-c",
@@ -213,6 +395,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-arm64.configure",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -231,6 +425,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-arm64.ninja",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -249,7 +455,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "-d"
@@ -262,6 +468,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.linux-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -281,6 +499,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.linux-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -298,6 +528,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.linux-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -316,7 +558,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "--use-lto",
@@ -331,6 +573,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -350,6 +604,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -367,6 +633,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -400,6 +678,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.upload.build gn/gn/linux-amd64",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@3@@@",
@@ -430,6 +720,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.upload.cipd search gn/gn/linux-amd64 git_revision:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@3@@@",
@@ -460,7 +762,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "--use-lto",
@@ -475,6 +777,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-arm64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -494,6 +808,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-arm64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -527,6 +853,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-arm64.upload.build gn/gn/linux-arm64",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@3@@@",
@@ -557,6 +895,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-arm64.upload.cipd search gn/gn/linux-arm64 git_revision:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@3@@@",
diff --git a/gn/infra/recipes/gn.expected/cipd_register.json b/gn/infra/recipes/gn.expected/cipd_register.json
index 425046a04e7..650b9da20f1 100644
--- a/gn/infra/recipes/gn.expected/cipd_register.json
+++ b/gn/infra/recipes/gn.expected/cipd_register.json
@@ -10,6 +10,18 @@
       "[START_DIR]/gn"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.init",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -25,6 +37,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.fetch",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -38,6 +62,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.checkout",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -51,6 +87,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.rev-parse",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -70,6 +118,18 @@
       "/path/to/tmp/json"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "ensure_installed",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -105,6 +165,18 @@
       "init",
       "[START_DIR]/rpmalloc"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.init",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -116,10 +188,22 @@
       "fetch",
       "--tags",
       "https://fuchsia.googlesource.com/third_party/github.com/mjansson/rpmalloc",
-      "f4b7c52c858675f732a76bd1c73447e0fcf84b1e"
+      "+upstream/develop"
     ],
     "cwd": "[START_DIR]/rpmalloc",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.fetch",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -129,16 +213,90 @@
     "cmd": [
       "git",
       "checkout",
-      "FETCH_HEAD"
+      "668a7f81b588a985c6528b70674dbcc005d9cb75"
     ],
     "cwd": "[START_DIR]/rpmalloc",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.checkout",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
     ]
   },
   {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "copy",
+      "[START_DIR]/rpmalloc/build/ninja/clang.py",
+      "/path/to/tmp/"
+    ],
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "rpmalloc.read [START_DIR]/rpmalloc/build/ninja/clang.py",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_LOG_LINE@clang.py@CXXFLAGS = ['-Wall', '-Weverything', '-Wfoo']@@@",
+      "@@@STEP_LOG_END@clang.py@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "copy",
+      "CXXFLAGS = ['-Wall', '-Weverything', '-Wfoo']",
+      "[START_DIR]/rpmalloc/build/ninja/clang.py"
+    ],
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "rpmalloc.write [START_DIR]/rpmalloc/build/ninja/clang.py",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_LOG_LINE@clang.py@CXXFLAGS = ['-Wall', '-Weverything', '-Wfoo']@@@",
+      "@@@STEP_LOG_END@clang.py@@@"
+    ]
+  },
+  {
     "cmd": [],
     "name": "rpmalloc.build rpmalloc-linux-amd64",
     "~followup_annotations": [
@@ -147,7 +305,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/rpmalloc/configure.py",
       "-c",
@@ -164,6 +322,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-amd64.configure",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -182,6 +352,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-amd64.ninja",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -196,7 +378,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/rpmalloc/configure.py",
       "-c",
@@ -213,6 +395,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-arm64.configure",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -231,6 +425,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-arm64.ninja",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -249,7 +455,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "-d"
@@ -262,6 +468,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.linux-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -281,6 +499,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.linux-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -298,6 +528,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.linux-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -316,7 +558,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "--use-lto",
@@ -331,6 +573,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -350,6 +604,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -367,6 +633,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -400,6 +678,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.upload.build gn/gn/linux-amd64",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@3@@@",
@@ -430,6 +720,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.upload.cipd search gn/gn/linux-amd64 git_revision:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@3@@@",
@@ -461,6 +763,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.upload.register gn/gn/linux-amd64",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@3@@@",
@@ -483,7 +797,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "--use-lto",
@@ -498,6 +812,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-arm64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -517,6 +843,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-arm64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -550,6 +888,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-arm64.upload.build gn/gn/linux-arm64",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@3@@@",
@@ -580,6 +930,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "infra-internal:ci"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-arm64.upload.cipd search gn/gn/linux-arm64 git_revision:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@3@@@",
diff --git a/gn/infra/recipes/gn.expected/cq_linux.json b/gn/infra/recipes/gn.expected/cq_linux.json
index 4e32325bb46..1259594a205 100644
--- a/gn/infra/recipes/gn.expected/cq_linux.json
+++ b/gn/infra/recipes/gn.expected/cq_linux.json
@@ -10,6 +10,18 @@
       "[START_DIR]/gn"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.init",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -25,6 +37,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.fetch",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -38,6 +62,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.checkout",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -51,6 +87,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.rev-parse",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -65,6 +113,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.fetch 123456/7",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -78,6 +138,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.checkout 123456/7",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -97,6 +169,18 @@
       "/path/to/tmp/json"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "ensure_installed",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -132,6 +216,18 @@
       "init",
       "[START_DIR]/rpmalloc"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.init",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -143,10 +239,22 @@
       "fetch",
       "--tags",
       "https://fuchsia.googlesource.com/third_party/github.com/mjansson/rpmalloc",
-      "f4b7c52c858675f732a76bd1c73447e0fcf84b1e"
+      "+upstream/develop"
     ],
     "cwd": "[START_DIR]/rpmalloc",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.fetch",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -156,16 +264,90 @@
     "cmd": [
       "git",
       "checkout",
-      "FETCH_HEAD"
+      "668a7f81b588a985c6528b70674dbcc005d9cb75"
     ],
     "cwd": "[START_DIR]/rpmalloc",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.checkout",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
     ]
   },
   {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "copy",
+      "[START_DIR]/rpmalloc/build/ninja/clang.py",
+      "/path/to/tmp/"
+    ],
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "rpmalloc.read [START_DIR]/rpmalloc/build/ninja/clang.py",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_LOG_LINE@clang.py@CXXFLAGS = ['-Wall', '-Weverything', '-Wfoo']@@@",
+      "@@@STEP_LOG_END@clang.py@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "copy",
+      "CXXFLAGS = ['-Wall', '-Weverything', '-Wfoo']",
+      "[START_DIR]/rpmalloc/build/ninja/clang.py"
+    ],
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "rpmalloc.write [START_DIR]/rpmalloc/build/ninja/clang.py",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@1@@@",
+      "@@@STEP_LOG_LINE@clang.py@CXXFLAGS = ['-Wall', '-Weverything', '-Wfoo']@@@",
+      "@@@STEP_LOG_END@clang.py@@@"
+    ]
+  },
+  {
     "cmd": [],
     "name": "rpmalloc.build rpmalloc-linux-amd64",
     "~followup_annotations": [
@@ -174,7 +356,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/rpmalloc/configure.py",
       "-c",
@@ -191,6 +373,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-amd64.configure",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -209,6 +403,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-amd64.ninja",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -223,7 +429,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/rpmalloc/configure.py",
       "-c",
@@ -240,6 +446,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-arm64.configure",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -258,6 +476,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "rpmalloc.build rpmalloc-linux-arm64.ninja",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -276,7 +506,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "-d"
@@ -289,6 +519,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.linux-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -308,6 +550,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.linux-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -325,6 +579,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.linux-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -343,7 +609,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "--use-lto",
@@ -358,6 +624,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -377,6 +655,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -394,6 +684,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -401,6 +703,185 @@
   },
   {
     "cmd": [],
+    "name": "release.linux-amd64.upload",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@2@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "copy",
+      "RECIPE_MODULE[recipe_engine::cas]/resources/infra.sha1",
+      "/path/to/tmp/"
+    ],
+    "cwd": "[START_DIR]/gn",
+    "env": {
+      "AR": "[START_DIR]/cipd/bin/llvm-ar",
+      "CC": "[START_DIR]/cipd/bin/clang",
+      "CFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot",
+      "CXX": "[START_DIR]/cipd/bin/clang++",
+      "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "release.linux-amd64.upload.read infra revision",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@3@@@",
+      "@@@STEP_LOG_LINE@infra.sha1@git_revision:mock_infra_git_revision@@@",
+      "@@@STEP_LOG_END@infra.sha1@@@"
+    ]
+  },
+  {
+    "cmd": [],
+    "name": "release.linux-amd64.upload.install infra/tools/luci/cas",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@3@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "ensure-directory",
+      "--mode",
+      "0777",
+      "[START_DIR]/cipd_tool/infra/tools/luci/cas/git_revision%3Amock_infra_git_revision"
+    ],
+    "cwd": "[START_DIR]/gn",
+    "env": {
+      "AR": "[START_DIR]/cipd/bin/llvm-ar",
+      "CC": "[START_DIR]/cipd/bin/clang",
+      "CFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot",
+      "CXX": "[START_DIR]/cipd/bin/clang++",
+      "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "release.linux-amd64.upload.install infra/tools/luci/cas.ensure package directory",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@4@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "cipd",
+      "ensure",
+      "-root",
+      "[START_DIR]/cipd_tool/infra/tools/luci/cas/git_revision%3Amock_infra_git_revision",
+      "-ensure-file",
+      "infra/tools/luci/cas/${platform} git_revision:mock_infra_git_revision",
+      "-max-threads",
+      "0",
+      "-json-output",
+      "/path/to/tmp/json"
+    ],
+    "cwd": "[START_DIR]/gn",
+    "env": {
+      "AR": "[START_DIR]/cipd/bin/llvm-ar",
+      "CC": "[START_DIR]/cipd/bin/clang",
+      "CFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot",
+      "CXX": "[START_DIR]/cipd/bin/clang++",
+      "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "release.linux-amd64.upload.install infra/tools/luci/cas.ensure_installed",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@4@@@",
+      "@@@STEP_LOG_LINE@json.output@{@@@",
+      "@@@STEP_LOG_LINE@json.output@  \"result\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@    \"\": [@@@",
+      "@@@STEP_LOG_LINE@json.output@      {@@@",
+      "@@@STEP_LOG_LINE@json.output@        \"instance_id\": \"resolved-instance_id-of-git_revision:moc\", @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"package\": \"infra/tools/luci/cas/resolved-platform\"@@@",
+      "@@@STEP_LOG_LINE@json.output@      }@@@",
+      "@@@STEP_LOG_LINE@json.output@    ]@@@",
+      "@@@STEP_LOG_LINE@json.output@  }@@@",
+      "@@@STEP_LOG_LINE@json.output@}@@@",
+      "@@@STEP_LOG_END@json.output@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "[START_DIR]/cipd_tool/infra/tools/luci/cas/git_revision%3Amock_infra_git_revision/cas",
+      "archive",
+      "-cas-instance",
+      "projects/example-cas-server/instances/default_instance",
+      "-dump-digest",
+      "/path/to/tmp/",
+      "-paths",
+      "[START_DIR]/gn/out:gn"
+    ],
+    "cwd": "[START_DIR]/gn",
+    "env": {
+      "AR": "[START_DIR]/cipd/bin/llvm-ar",
+      "CC": "[START_DIR]/cipd/bin/clang",
+      "CFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot",
+      "CXX": "[START_DIR]/cipd/bin/clang++",
+      "LDFLAGS": "--target=x86_64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "release.linux-amd64.upload.upload binary to CAS",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@3@@@",
+      "@@@STEP_LINK@CAS UI@https://cas-viewer.appspot.com/projects/example-cas-server/instances/default_instance/blobs/e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855/0/tree@@@"
+    ]
+  },
+  {
+    "cmd": [],
     "name": "release.linux-arm64",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -408,7 +889,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "--use-lto",
@@ -423,6 +904,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-arm64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -442,12 +935,69 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.linux-arm64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
     ]
   },
   {
+    "cmd": [],
+    "name": "release.linux-arm64.upload",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@2@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "[START_DIR]/cipd_tool/infra/tools/luci/cas/git_revision%3Amock_infra_git_revision/cas",
+      "archive",
+      "-cas-instance",
+      "projects/example-cas-server/instances/default_instance",
+      "-dump-digest",
+      "/path/to/tmp/",
+      "-paths",
+      "[START_DIR]/gn/out:gn"
+    ],
+    "cwd": "[START_DIR]/gn",
+    "env": {
+      "AR": "[START_DIR]/cipd/bin/llvm-ar",
+      "CC": "[START_DIR]/cipd/bin/clang",
+      "CFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot",
+      "CXX": "[START_DIR]/cipd/bin/clang++",
+      "LDFLAGS": "--target=aarch64-linux-gnu --sysroot=[START_DIR]/cipd/sysroot -static-libstdc++"
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "release.linux-arm64.upload.upload binary to CAS",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@3@@@",
+      "@@@STEP_LINK@CAS UI@https://cas-viewer.appspot.com/projects/example-cas-server/instances/default_instance/blobs/e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855/0/tree@@@"
+    ]
+  },
+  {
     "name": "$result"
   }
 ]
 \ No newline at end of file
diff --git a/gn/infra/recipes/gn.expected/cq_mac.json b/gn/infra/recipes/gn.expected/cq_mac.json
index 908c60daf8a..cc3ec5f389b 100644
--- a/gn/infra/recipes/gn.expected/cq_mac.json
+++ b/gn/infra/recipes/gn.expected/cq_mac.json
@@ -10,6 +10,18 @@
       "[START_DIR]/gn"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.init",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -25,6 +37,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.fetch",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -38,6 +62,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.checkout",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -51,6 +87,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.rev-parse",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -65,6 +113,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.fetch 123456/7",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -78,6 +138,18 @@
     ],
     "cwd": "[START_DIR]/gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.checkout 123456/7",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -97,6 +169,18 @@
       "/path/to/tmp/json"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "ensure_installed",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -130,6 +214,18 @@
       "/path/to/tmp/json"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "ensure_installed (2)",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -157,6 +253,18 @@
       "[CACHE]/macos_sdk/XCode.app"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "install xcode"
   },
   {
@@ -167,6 +275,18 @@
       "[CACHE]/macos_sdk/XCode.app"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "select XCode"
   },
   {
@@ -178,11 +298,23 @@
       "xcrun",
       "--show-sdk-path"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.xcrun sdk-path",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_LOG_LINE@raw_io.output[sdk-path]@/some/xcode/path@@@",
-      "@@@STEP_LOG_END@raw_io.output[sdk-path]@@@"
+      "@@@STEP_LOG_LINE@raw_io.output_text[sdk-path]@/some/xcode/path@@@",
+      "@@@STEP_LOG_END@raw_io.output_text[sdk-path]@@@"
     ]
   },
   {
@@ -194,13 +326,25 @@
       "-xc++",
       "-fsyntax-only",
       "-Wp,-v",
-      "-"
+      "/dev/null"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.xcrun toolchain",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_LOG_LINE@raw_io.output[toolchain]@[CACHE]/macos_sdk/XCode.app/include/c++/v1@@@",
-      "@@@STEP_LOG_END@raw_io.output[toolchain]@@@"
+      "@@@STEP_LOG_LINE@raw_io.output_text[toolchain]@[CACHE]/macos_sdk/XCode.app/include/c++/v1@@@",
+      "@@@STEP_LOG_END@raw_io.output_text[toolchain]@@@"
     ]
   },
   {
@@ -212,7 +356,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "-d"
@@ -225,6 +369,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.mac-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -244,6 +400,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.mac-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -261,6 +429,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.mac-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -275,11 +455,23 @@
       "xcrun",
       "--show-sdk-path"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.xcrun sdk-path",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_LOG_LINE@raw_io.output[sdk-path]@/some/xcode/path@@@",
-      "@@@STEP_LOG_END@raw_io.output[sdk-path]@@@"
+      "@@@STEP_LOG_LINE@raw_io.output_text[sdk-path]@/some/xcode/path@@@",
+      "@@@STEP_LOG_END@raw_io.output_text[sdk-path]@@@"
     ]
   },
   {
@@ -291,13 +483,25 @@
       "-xc++",
       "-fsyntax-only",
       "-Wp,-v",
-      "-"
+      "/dev/null"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.xcrun toolchain",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_LOG_LINE@raw_io.output[toolchain]@[CACHE]/macos_sdk/XCode.app/include/c++/v1@@@",
-      "@@@STEP_LOG_END@raw_io.output[toolchain]@@@"
+      "@@@STEP_LOG_LINE@raw_io.output_text[toolchain]@[CACHE]/macos_sdk/XCode.app/include/c++/v1@@@",
+      "@@@STEP_LOG_END@raw_io.output_text[toolchain]@@@"
     ]
   },
   {
@@ -309,7 +513,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "--use-lto",
@@ -323,6 +527,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.mac-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -342,6 +558,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.mac-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -359,21 +587,224 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.mac-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
     ]
   },
   {
+    "cmd": [],
+    "name": "release.mac-amd64.upload",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@2@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "copy",
+      "RECIPE_MODULE[recipe_engine::cas]/resources/infra.sha1",
+      "/path/to/tmp/"
+    ],
+    "cwd": "[START_DIR]/gn",
+    "env": {
+      "AR": "[START_DIR]/cipd/bin/llvm-ar",
+      "CC": "[START_DIR]/cipd/bin/clang",
+      "CFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path -nostdinc++ -cxx-isystem [CACHE]/macos_sdk/XCode.app/include/c++/v1",
+      "CXX": "[START_DIR]/cipd/bin/clang++",
+      "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "release.mac-amd64.upload.read infra revision",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@3@@@",
+      "@@@STEP_LOG_LINE@infra.sha1@git_revision:mock_infra_git_revision@@@",
+      "@@@STEP_LOG_END@infra.sha1@@@"
+    ]
+  },
+  {
+    "cmd": [],
+    "name": "release.mac-amd64.upload.install infra/tools/luci/cas",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@3@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]/resources/fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "ensure-directory",
+      "--mode",
+      "0777",
+      "[START_DIR]/cipd_tool/infra/tools/luci/cas/git_revision%3Amock_infra_git_revision"
+    ],
+    "cwd": "[START_DIR]/gn",
+    "env": {
+      "AR": "[START_DIR]/cipd/bin/llvm-ar",
+      "CC": "[START_DIR]/cipd/bin/clang",
+      "CFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path -nostdinc++ -cxx-isystem [CACHE]/macos_sdk/XCode.app/include/c++/v1",
+      "CXX": "[START_DIR]/cipd/bin/clang++",
+      "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "release.mac-amd64.upload.install infra/tools/luci/cas.ensure package directory",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@4@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "cipd",
+      "ensure",
+      "-root",
+      "[START_DIR]/cipd_tool/infra/tools/luci/cas/git_revision%3Amock_infra_git_revision",
+      "-ensure-file",
+      "infra/tools/luci/cas/${platform} git_revision:mock_infra_git_revision",
+      "-max-threads",
+      "0",
+      "-json-output",
+      "/path/to/tmp/json"
+    ],
+    "cwd": "[START_DIR]/gn",
+    "env": {
+      "AR": "[START_DIR]/cipd/bin/llvm-ar",
+      "CC": "[START_DIR]/cipd/bin/clang",
+      "CFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path -nostdinc++ -cxx-isystem [CACHE]/macos_sdk/XCode.app/include/c++/v1",
+      "CXX": "[START_DIR]/cipd/bin/clang++",
+      "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "release.mac-amd64.upload.install infra/tools/luci/cas.ensure_installed",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@4@@@",
+      "@@@STEP_LOG_LINE@json.output@{@@@",
+      "@@@STEP_LOG_LINE@json.output@  \"result\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@    \"\": [@@@",
+      "@@@STEP_LOG_LINE@json.output@      {@@@",
+      "@@@STEP_LOG_LINE@json.output@        \"instance_id\": \"resolved-instance_id-of-git_revision:moc\", @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"package\": \"infra/tools/luci/cas/resolved-platform\"@@@",
+      "@@@STEP_LOG_LINE@json.output@      }@@@",
+      "@@@STEP_LOG_LINE@json.output@    ]@@@",
+      "@@@STEP_LOG_LINE@json.output@  }@@@",
+      "@@@STEP_LOG_LINE@json.output@}@@@",
+      "@@@STEP_LOG_END@json.output@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "[START_DIR]/cipd_tool/infra/tools/luci/cas/git_revision%3Amock_infra_git_revision/cas",
+      "archive",
+      "-cas-instance",
+      "projects/example-cas-server/instances/default_instance",
+      "-dump-digest",
+      "/path/to/tmp/",
+      "-paths",
+      "[START_DIR]/gn/out:gn"
+    ],
+    "cwd": "[START_DIR]/gn",
+    "env": {
+      "AR": "[START_DIR]/cipd/bin/llvm-ar",
+      "CC": "[START_DIR]/cipd/bin/clang",
+      "CFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path -nostdinc++ -cxx-isystem [CACHE]/macos_sdk/XCode.app/include/c++/v1",
+      "CXX": "[START_DIR]/cipd/bin/clang++",
+      "LDFLAGS": "--target=x86_64-apple-darwin --sysroot=/some/xcode/path"
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "release.mac-amd64.upload.upload binary to CAS",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@3@@@",
+      "@@@STEP_LINK@CAS UI@https://cas-viewer.appspot.com/projects/example-cas-server/instances/default_instance/blobs/e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855/0/tree@@@"
+    ]
+  },
+  {
     "cmd": [
       "xcrun",
       "--show-sdk-path"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.xcrun sdk-path (2)",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_LOG_LINE@raw_io.output[sdk-path]@/some/xcode/path@@@",
-      "@@@STEP_LOG_END@raw_io.output[sdk-path]@@@"
+      "@@@STEP_LOG_LINE@raw_io.output_text[sdk-path]@/some/xcode/path@@@",
+      "@@@STEP_LOG_END@raw_io.output_text[sdk-path]@@@"
     ]
   },
   {
@@ -385,13 +816,25 @@
       "-xc++",
       "-fsyntax-only",
       "-Wp,-v",
-      "-"
+      "/dev/null"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.xcrun toolchain (2)",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@",
-      "@@@STEP_LOG_LINE@raw_io.output[toolchain]@[CACHE]/macos_sdk/XCode.app/include/c++/v1@@@",
-      "@@@STEP_LOG_END@raw_io.output[toolchain]@@@"
+      "@@@STEP_LOG_LINE@raw_io.output_text[toolchain]@[CACHE]/macos_sdk/XCode.app/include/c++/v1@@@",
+      "@@@STEP_LOG_END@raw_io.output_text[toolchain]@@@"
     ]
   },
   {
@@ -403,7 +846,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]/gn/build/gen.py",
       "--use-lto",
@@ -417,6 +860,18 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=arm64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.mac-arm64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -436,18 +891,87 @@
       "CXX": "[START_DIR]/cipd/bin/clang++",
       "LDFLAGS": "--target=arm64-apple-darwin --sysroot=/some/xcode/path"
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.mac-arm64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
     ]
   },
   {
+    "cmd": [],
+    "name": "release.mac-arm64.upload",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@2@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "[START_DIR]/cipd_tool/infra/tools/luci/cas/git_revision%3Amock_infra_git_revision/cas",
+      "archive",
+      "-cas-instance",
+      "projects/example-cas-server/instances/default_instance",
+      "-dump-digest",
+      "/path/to/tmp/",
+      "-paths",
+      "[START_DIR]/gn/out:gn"
+    ],
+    "cwd": "[START_DIR]/gn",
+    "env": {
+      "AR": "[START_DIR]/cipd/bin/llvm-ar",
+      "CC": "[START_DIR]/cipd/bin/clang",
+      "CFLAGS": "--target=arm64-apple-darwin --sysroot=/some/xcode/path -nostdinc++ -cxx-isystem [CACHE]/macos_sdk/XCode.app/include/c++/v1",
+      "CXX": "[START_DIR]/cipd/bin/clang++",
+      "LDFLAGS": "--target=arm64-apple-darwin --sysroot=/some/xcode/path"
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "release.mac-arm64.upload.upload binary to CAS",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@3@@@",
+      "@@@STEP_LINK@CAS UI@https://cas-viewer.appspot.com/projects/example-cas-server/instances/default_instance/blobs/e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855/0/tree@@@"
+    ]
+  },
+  {
     "cmd": [
       "sudo",
       "xcode-select",
       "--reset"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "reset XCode"
   },
   {
diff --git a/gn/infra/recipes/gn.expected/cq_win.json b/gn/infra/recipes/gn.expected/cq_win.json
index 5612924b5b6..792e0e93ab2 100644
--- a/gn/infra/recipes/gn.expected/cq_win.json
+++ b/gn/infra/recipes/gn.expected/cq_win.json
@@ -10,6 +10,18 @@
       "[START_DIR]\\gn"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.init",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -25,6 +37,18 @@
     ],
     "cwd": "[START_DIR]\\gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.fetch",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -38,6 +62,18 @@
     ],
     "cwd": "[START_DIR]\\gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.checkout",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -51,6 +87,18 @@
     ],
     "cwd": "[START_DIR]\\gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.rev-parse",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -65,6 +113,18 @@
     ],
     "cwd": "[START_DIR]\\gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.fetch 123456/7",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -78,6 +138,18 @@
     ],
     "cwd": "[START_DIR]\\gn",
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "git.checkout 123456/7",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@1@@@"
@@ -97,6 +169,18 @@
       "/path/to/tmp/json"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "ensure_installed",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -126,6 +210,18 @@
       "/path/to/tmp/json"
     ],
     "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "ensure_installed (2)",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -143,12 +239,24 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
-      "\nimport shutil\nimport sys\nshutil.copy(sys.argv[1], sys.argv[2])\n",
+      "RECIPE_MODULE[recipe_engine::json]\\resources\\read.py",
       "[CACHE]\\windows_sdk\\win_sdk\\bin\\SetEnv.x64.json",
       "/path/to/tmp/json"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "read SetEnv.x64.json",
     "~followup_annotations": [
       "@@@STEP_LOG_LINE@json.output@{@@@",
@@ -186,7 +294,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]\\gn\\build\\gen.py",
       "-d"
@@ -200,6 +308,18 @@
         "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
       ]
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.windows-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -220,6 +340,18 @@
         "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
       ]
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.windows-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -238,6 +370,18 @@
         "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
       ]
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "debug.windows-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -256,7 +400,7 @@
   },
   {
     "cmd": [
-      "python",
+      "python3",
       "-u",
       "[START_DIR]\\gn\\build\\gen.py",
       "--use-lto",
@@ -271,6 +415,18 @@
         "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
       ]
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.windows-amd64.generate",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -291,6 +447,18 @@
         "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
       ]
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.windows-amd64.build",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
@@ -309,12 +477,207 @@
         "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
       ]
     },
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "release.windows-amd64.test",
     "~followup_annotations": [
       "@@@STEP_NEST_LEVEL@2@@@"
     ]
   },
   {
+    "cmd": [],
+    "name": "release.windows-amd64.upload",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@2@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]\\resources\\fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "copy",
+      "RECIPE_MODULE[recipe_engine::cas]\\resources\\infra.sha1",
+      "/path/to/tmp/"
+    ],
+    "cwd": "[START_DIR]\\gn",
+    "env": {
+      "VSINSTALLDIR": "[CACHE]\\windows_sdk"
+    },
+    "env_prefixes": {
+      "PATH": [
+        "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
+      ]
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "release.windows-amd64.upload.read infra revision",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@3@@@",
+      "@@@STEP_LOG_LINE@infra.sha1@git_revision:mock_infra_git_revision@@@",
+      "@@@STEP_LOG_END@infra.sha1@@@"
+    ]
+  },
+  {
+    "cmd": [],
+    "name": "release.windows-amd64.upload.install infra/tools/luci/cas",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@3@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "vpython3",
+      "-u",
+      "RECIPE_MODULE[recipe_engine::file]\\resources\\fileutil.py",
+      "--json-output",
+      "/path/to/tmp/json",
+      "ensure-directory",
+      "--mode",
+      "0777",
+      "[START_DIR]\\cipd_tool\\infra\\tools\\luci\\cas\\git_revision%3Amock_infra_git_revision"
+    ],
+    "cwd": "[START_DIR]\\gn",
+    "env": {
+      "VSINSTALLDIR": "[CACHE]\\windows_sdk"
+    },
+    "env_prefixes": {
+      "PATH": [
+        "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
+      ]
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "release.windows-amd64.upload.install infra/tools/luci/cas.ensure package directory",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@4@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "cipd.bat",
+      "ensure",
+      "-root",
+      "[START_DIR]\\cipd_tool\\infra\\tools\\luci\\cas\\git_revision%3Amock_infra_git_revision",
+      "-ensure-file",
+      "infra/tools/luci/cas/${platform} git_revision:mock_infra_git_revision",
+      "-max-threads",
+      "0",
+      "-json-output",
+      "/path/to/tmp/json"
+    ],
+    "cwd": "[START_DIR]\\gn",
+    "env": {
+      "VSINSTALLDIR": "[CACHE]\\windows_sdk"
+    },
+    "env_prefixes": {
+      "PATH": [
+        "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
+      ]
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "release.windows-amd64.upload.install infra/tools/luci/cas.ensure_installed",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@4@@@",
+      "@@@STEP_LOG_LINE@json.output@{@@@",
+      "@@@STEP_LOG_LINE@json.output@  \"result\": {@@@",
+      "@@@STEP_LOG_LINE@json.output@    \"\": [@@@",
+      "@@@STEP_LOG_LINE@json.output@      {@@@",
+      "@@@STEP_LOG_LINE@json.output@        \"instance_id\": \"resolved-instance_id-of-git_revision:moc\", @@@",
+      "@@@STEP_LOG_LINE@json.output@        \"package\": \"infra/tools/luci/cas/resolved-platform\"@@@",
+      "@@@STEP_LOG_LINE@json.output@      }@@@",
+      "@@@STEP_LOG_LINE@json.output@    ]@@@",
+      "@@@STEP_LOG_LINE@json.output@  }@@@",
+      "@@@STEP_LOG_LINE@json.output@}@@@",
+      "@@@STEP_LOG_END@json.output@@@"
+    ]
+  },
+  {
+    "cmd": [
+      "[START_DIR]\\cipd_tool\\infra\\tools\\luci\\cas\\git_revision%3Amock_infra_git_revision\\cas",
+      "archive",
+      "-cas-instance",
+      "projects/example-cas-server/instances/default_instance",
+      "-dump-digest",
+      "/path/to/tmp/",
+      "-paths",
+      "[START_DIR]\\gn\\out:gn.exe"
+    ],
+    "cwd": "[START_DIR]\\gn",
+    "env": {
+      "VSINSTALLDIR": "[CACHE]\\windows_sdk"
+    },
+    "env_prefixes": {
+      "PATH": [
+        "[CACHE]\\windows_sdk\\win_sdk\\bin\\x64"
+      ]
+    },
+    "infra_step": true,
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
+    "name": "release.windows-amd64.upload.upload binary to CAS",
+    "~followup_annotations": [
+      "@@@STEP_NEST_LEVEL@3@@@",
+      "@@@STEP_LINK@CAS UI@https://cas-viewer.appspot.com/projects/example-cas-server/instances/default_instance/blobs/e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855/0/tree@@@"
+    ]
+  },
+  {
     "cmd": [
       "taskkill.exe",
       "/f",
@@ -322,6 +685,18 @@
       "/im",
       "mspdbsrv.exe"
     ],
+    "luci_context": {
+      "realm": {
+        "name": "gn:try"
+      },
+      "resultdb": {
+        "current_invocation": {
+          "name": "invocations/build:8945511751514863184",
+          "update_token": "token"
+        },
+        "hostname": "rdbhost"
+      }
+    },
     "name": "taskkill mspdbsrv"
   },
   {
diff --git a/gn/infra/recipes/gn.py b/gn/infra/recipes/gn.py
index 6ba79ae2823..7cb6229f6ba 100644
--- a/gn/infra/recipes/gn.py
+++ b/gn/infra/recipes/gn.py
@@ -7,6 +7,7 @@ from recipe_engine.recipe_api import Property
 
 DEPS = [
     'recipe_engine/buildbucket',
+    'recipe_engine/cas',
     'recipe_engine/cipd',
     'recipe_engine/context',
     'recipe_engine/file',
@@ -14,7 +15,6 @@ DEPS = [
     'recipe_engine/path',
     'recipe_engine/platform',
     'recipe_engine/properties',
-    'recipe_engine/python',
     'recipe_engine/raw_io',
     'recipe_engine/step',
     'target',
@@ -28,7 +28,8 @@ PROPERTIES = {
 
 # On select platforms, link the GN executable against rpmalloc for a small 10% speed boost.
 RPMALLOC_GIT_URL = 'https://fuchsia.googlesource.com/third_party/github.com/mjansson/rpmalloc'
-RPMALLOC_REVISION = 'f4b7c52c858675f732a76bd1c73447e0fcf84b1e'
+RPMALLOC_BRANCH = '+upstream/develop'
+RPMALLOC_REVISION = '668a7f81b588a985c6528b70674dbcc005d9cb75'
 
 # Used to convert os and arch strings to rpmalloc format
 RPMALLOC_MAP = {
@@ -42,10 +43,10 @@ def _get_libcxx_include_path(api):
   lines = api.step(
       'xcrun toolchain', [
           'xcrun', '--toolchain', 'clang', 'clang++', '-xc++', '-fsyntax-only',
-          '-Wp,-v', '-'
+          '-Wp,-v', '/dev/null'
       ],
-      stderr=api.raw_io.output(name='toolchain', add_output_log=True),
-      step_test_data=lambda: api.raw_io.test_api.stream_output(
+      stderr=api.raw_io.output_text(name='toolchain', add_output_log=True),
+      step_test_data=lambda: api.raw_io.test_api.stream_output_text(
           str(api.macos_sdk.sdk_dir.join('include', 'c++', 'v1')),
           stream='stderr')).stderr.splitlines()
   # Iterate over all include paths and look for the SDK libc++ one.
@@ -72,8 +73,8 @@ def _get_compilation_environment(api, target, cipd_dir):
     triple = '--target=%s' % target.triple
     sysroot = '--sysroot=%s' % api.step(
         'xcrun sdk-path', ['xcrun', '--show-sdk-path'],
-        stdout=api.raw_io.output(name='sdk-path', add_output_log=True),
-        step_test_data=lambda: api.raw_io.test_api.stream_output(
+        stdout=api.raw_io.output_text(name='sdk-path', add_output_log=True),
+        step_test_data=lambda: api.raw_io.test_api.stream_output_text(
             '/some/xcode/path')).stdout.strip()
     stdlib = cipd_dir.join('lib', 'libc++.a')
     cxx_include = _get_libcxx_include_path(api)
@@ -117,7 +118,7 @@ def RunSteps(api, repository):
       api.step('checkout', ['git', 'checkout', 'FETCH_HEAD'])
       revision = api.step(
           'rev-parse', ['git', 'rev-parse', 'HEAD'],
-          stdout=api.raw_io.output()).stdout.strip()
+          stdout=api.raw_io.output_text()).stdout.strip()
       for change in build_input.gerrit_changes:
         api.step('fetch %s/%s' % (change.change, change.patchset), [
             'git', 'fetch', repository,
@@ -195,8 +196,22 @@ def RunSteps(api, repository):
         with api.context(cwd=rpmalloc_src_dir, infra_steps=True):
           api.step(
               'fetch',
-              ['git', 'fetch', '--tags', RPMALLOC_GIT_URL, RPMALLOC_REVISION])
-          api.step('checkout', ['git', 'checkout', 'FETCH_HEAD'])
+              ['git', 'fetch', '--tags', RPMALLOC_GIT_URL, RPMALLOC_BRANCH])
+          api.step('checkout', ['git', 'checkout', RPMALLOC_REVISION])
+
+        # Patch configure.py since to add -Wno-unsafe-buffer-usage since Clang-16 will
+        # now complain about this when building rpmalloc (latest version only
+        # supports clang-15).
+        build_ninja_clang_path = api.path.join(rpmalloc_src_dir, 'build/ninja/clang.py')
+        build_ninja_clang_py = api.file.read_text('read %s' % build_ninja_clang_path,
+                                                 build_ninja_clang_path,
+                                                 "CXXFLAGS = ['-Wall', '-Weverything', '-Wfoo']")
+        build_ninja_clang_py = build_ninja_clang_py.replace(
+            "'-Wno-disabled-macro-expansion'",
+            "'-Wno-disabled-macro-expansion', '-Wno-unsafe-buffer-usage'")
+        api.file.write_text('write %s' % build_ninja_clang_path,
+                            build_ninja_clang_path,
+                            build_ninja_clang_py)
 
         for platform in all_config_platforms:
           # Convert target architecture and os to rpmalloc format.
@@ -209,10 +224,10 @@ def RunSteps(api, repository):
                                              cipd_dir)
           with api.step.nest('build rpmalloc-' + platform), api.context(
               env=env, cwd=rpmalloc_src_dir):
-            api.python(
+            api.step(
                 'configure',
-                rpmalloc_src_dir.join('configure.py'),
-                args=['-c', 'release', '-a', rpmalloc_arch, '--lto'])
+                ['python3', '-u', rpmalloc_src_dir.join('configure.py')] +
+                ['-c', 'release', '-a', rpmalloc_arch, '--lto'])
 
             # NOTE: Only build the static library.
             rpmalloc_static_lib = api.path.join('lib', rpmalloc_os, 'release',
@@ -235,7 +250,8 @@ def RunSteps(api, repository):
                   '--link-lib=%s' % rpmalloc_static_libs[target.platform]
               ]
 
-            api.python('generate', src_dir.join('build', 'gen.py'), args=args)
+            api.step('generate',
+                     ['python3', '-u', src_dir.join('build', 'gen.py')] + args)
 
             # Windows requires the environment modifications when building too.
             api.step('build',
@@ -245,16 +261,20 @@ def RunSteps(api, repository):
             if target.is_host:
               api.step('test', [src_dir.join('out', 'gn_unittests')])
 
-            if build_input.gerrit_changes:
-              continue
-
             if config['name'] != 'release':
               continue
 
             with api.step.nest('upload'):
-              cipd_pkg_name = 'gn/gn/%s' % target.platform
               gn = 'gn' + ('.exe' if target.is_win else '')
 
+              if build_input.gerrit_changes:
+                # Upload to CAS from CQ.
+                api.cas.archive('upload binary to CAS', src_dir.join('out'),
+                                src_dir.join('out', gn))
+                continue
+
+              cipd_pkg_name = 'gn/gn/%s' % target.platform
+
               pkg_def = api.cipd.PackageDefinition(
                   package_name=cipd_pkg_name,
                   package_root=src_dir.join('out'),
@@ -306,7 +326,7 @@ def GenTests(api):
       git_repo='gn.googlesource.com/gn',
       revision='a' * 40,
   ) + api.step_data(
-      'git.rev-parse', api.raw_io.stream_output('a' * 40)
+      'git.rev-parse', api.raw_io.stream_output_text('a' * 40)
   ) + api.step_data(
       'release.linux-amd64.upload.cipd search gn/gn/linux-amd64 git_revision:' +
       'a' * 40,
@@ -318,7 +338,7 @@ def GenTests(api):
       git_repo='gn.googlesource.com/gn',
       revision='a' * 40,
   ) + api.step_data(
-      'git.rev-parse', api.raw_io.stream_output('a' * 40)
+      'git.rev-parse', api.raw_io.stream_output_text('a' * 40)
   ) + api.step_data(
       'release.linux-amd64.upload.cipd search gn/gn/linux-amd64 git_revision:' +
       'a' * 40, api.cipd.example_search('gn/gn/linux-amd64', [])))
diff --git a/gn/misc/vim/syntax/gn.vim b/gn/misc/vim/syntax/gn.vim
index 851cec6bf59..df2d0d8dc26 100644
--- a/gn/misc/vim/syntax/gn.vim
+++ b/gn/misc/vim/syntax/gn.vim
@@ -43,7 +43,7 @@ hi def link     gnFunctions         Macro
 
 " Variables
 syn keyword     gnVariable all_dependent_configs allow_circular_includes_from
-syn keyword     gnVariable args asmflags assert_no_deps
+syn keyword     gnVariable args arflags asmflags assert_no_deps
 syn keyword     gnVariable cflags cflags_c cflags_cc cflags_objc cflags_objcc
 syn keyword     gnVariable check_includes complete_static_lib configs
 syn keyword     gnVariable data data_deps data_keys defines depfile deps
diff --git a/gn/src/base/command_line.cc b/gn/src/base/command_line.cc
index 68bc58719d5..0c37d530dfa 100644
--- a/gn/src/base/command_line.cc
+++ b/gn/src/base/command_line.cc
@@ -184,6 +184,17 @@ CommandLine& CommandLine::operator=(const CommandLine& other) = default;
 CommandLine::~CommandLine() = default;
 
 #if defined(OS_WIN)
+
+// static
+std::string CommandLine::StringTypeToUTF8(const StringType& input) {
+  return UTF16ToUTF8(input);
+}
+
+// static
+CommandLine::StringType CommandLine::UTF8ToStringType(std::string_view input) {
+  return UTF8ToUTF16(input);
+}
+
 // static
 void CommandLine::set_slash_is_not_a_switch() {
   // The last switch prefix should be slash, so adjust the size to skip it.
@@ -202,6 +213,19 @@ void CommandLine::InitUsingArgvForTesting(int argc, const char* const* argv) {
     argv_vector.push_back(UTF8ToUTF16(argv[i]));
   current_process_commandline_->InitFromArgv(argv_vector);
 }
+
+#else
+
+// static
+std::string CommandLine::StringTypeToUTF8(const StringType& input) {
+  return input;
+}
+
+// static
+CommandLine::StringType CommandLine::UTF8ToStringType(std::string_view input) {
+  return CommandLine::StringType(input);
+}
+
 #endif
 
 // static
@@ -292,18 +316,9 @@ bool CommandLine::HasSwitch(const char switch_constant[]) const {
   return HasSwitch(std::string_view(switch_constant));
 }
 
-std::string CommandLine::GetSwitchValueASCII(
+std::string CommandLine::GetSwitchValueString(
     std::string_view switch_string) const {
-  StringType value = GetSwitchValueNative(switch_string);
-  if (!IsStringASCII(value)) {
-    DLOG(WARNING) << "Value of switch (" << switch_string << ") must be ASCII.";
-    return std::string();
-  }
-#if defined(OS_WIN)
-  return UTF16ToASCII(value);
-#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
-  return value;
-#endif
+  return StringTypeToUTF8(GetSwitchValueNative(switch_string));
 }
 
 FilePath CommandLine::GetSwitchValuePath(std::string_view switch_string) const {
@@ -313,8 +328,43 @@ FilePath CommandLine::GetSwitchValuePath(std::string_view switch_string) const {
 CommandLine::StringType CommandLine::GetSwitchValueNative(
     std::string_view switch_string) const {
   DCHECK_EQ(ToLowerASCII(switch_string), switch_string);
-  auto result = switches_.find(switch_string);
-  return result == switches_.end() ? StringType() : result->second;
+
+  // There can be multiple matches, we want to find the last one.
+  auto iter = switches_.upper_bound(switch_string);
+  if (iter == switches_.begin())
+    return StringType();
+
+  // We want the item right before the upper bound, if it's a match.
+  --iter;
+  if (iter->first == switch_string)
+    return iter->second;
+  return StringType();
+}
+
+std::vector<std::string> CommandLine::GetSwitchValueStrings(
+    std::string_view switch_string) const {
+  std::vector<StringType> matches = GetSwitchValuesNative(switch_string);
+
+  std::vector<std::string> result;
+  result.reserve(matches.size());
+
+  for (const StringType& cur : matches) {
+    result.push_back(StringTypeToUTF8(cur));
+  }
+  return result;
+}
+
+std::vector<CommandLine::StringType> CommandLine::GetSwitchValuesNative(
+    std::string_view switch_string) const {
+  std::vector<StringType> result;
+
+  auto [iter, end] = switches_.equal_range(switch_string);
+  while (iter != end) {
+    result.push_back(iter->second);
+    ++iter;
+  }
+
+  return result;
 }
 
 void CommandLine::AppendSwitch(const std::string& switch_string) {
@@ -335,11 +385,10 @@ void CommandLine::AppendSwitchNative(const std::string& switch_string,
   const std::string& switch_key = switch_string;
   StringType combined_switch_string(switch_key);
 #endif
+
   size_t prefix_length = GetSwitchPrefixLength(combined_switch_string);
-  auto insertion =
-      switches_.insert(make_pair(switch_key.substr(prefix_length), value));
-  if (!insertion.second)
-    insertion.first->second = value;
+  switches_.insert(make_pair(switch_key.substr(prefix_length), value));
+
   // Preserve existing switch prefixes in |argv_|; only append one if necessary.
   if (prefix_length == 0)
     combined_switch_string = kSwitchPrefixes[0] + combined_switch_string;
@@ -349,15 +398,9 @@ void CommandLine::AppendSwitchNative(const std::string& switch_string,
   argv_.insert(argv_.begin() + begin_args_++, combined_switch_string);
 }
 
-void CommandLine::AppendSwitchASCII(const std::string& switch_string,
-                                    const std::string& value_string) {
-#if defined(OS_WIN)
-  AppendSwitchNative(switch_string, ASCIIToUTF16(value_string));
-#elif defined(OS_POSIX) || defined(OS_FUCHSIA)
-  AppendSwitchNative(switch_string, value_string);
-#else
-#error Unsupported platform
-#endif
+void CommandLine::AppendSwitch(const std::string& switch_string,
+                               const std::string& value_string) {
+  AppendSwitchNative(switch_string, UTF8ToStringType(value_string));
 }
 
 void CommandLine::CopySwitchesFrom(const CommandLine& source,
diff --git a/gn/src/base/command_line.h b/gn/src/base/command_line.h
index 3a4434666cc..ba30749e63d 100644
--- a/gn/src/base/command_line.h
+++ b/gn/src/base/command_line.h
@@ -31,6 +31,7 @@ class CommandLine {
  public:
 #if defined(OS_WIN)
   // The native command line string type.
+  // See StringTypeToUTF8() and UTF8ToStringType() below.
   using StringType = std::u16string;
 #elif defined(OS_POSIX) || defined(OS_FUCHSIA)
   using StringType = std::string;
@@ -38,7 +39,7 @@ class CommandLine {
 
   using CharType = StringType::value_type;
   using StringVector = std::vector<StringType>;
-  using SwitchMap = std::map<std::string, StringType, std::less<>>;
+  using SwitchMap = std::multimap<std::string, StringType, std::less<>>;
 
   // A constructor for CommandLines that only carry switches and arguments.
   enum NoProgram { NO_PROGRAM };
@@ -57,6 +58,10 @@ class CommandLine {
 
   ~CommandLine();
 
+  // Converts the platform string type to/from UTF-8.
+  static std::string StringTypeToUTF8(const StringType& input);
+  static StringType UTF8ToStringType(std::string_view input);
+
 #if defined(OS_WIN)
   // By default this class will treat command-line arguments beginning with
   // slashes as switches on Windows, but not other platforms.
@@ -167,24 +172,35 @@ class CommandLine {
   bool HasSwitch(std::string_view switch_string) const;
   bool HasSwitch(const char switch_constant[]) const;
 
-  // Returns the value associated with the given switch. If the switch has no
-  // value or isn't present, this method returns the empty string.
-  // Switch names must be lowercase.
-  std::string GetSwitchValueASCII(std::string_view switch_string) const;
+  // Returns the last value associated with the given switch. If the switch has
+  // no value or isn't present, this method returns the empty string. Switch
+  // names must be lowercase.
+  //
+  // The "string" version returns an 8-bit representation. On Windows, this will
+  // convert to UTF-8, on 8-bit systems it will return the raw input.
+  std::string GetSwitchValueString(std::string_view switch_string) const;
   FilePath GetSwitchValuePath(std::string_view switch_string) const;
   StringType GetSwitchValueNative(std::string_view switch_string) const;
 
+  // Returns all values associated with the given switch.
+  std::vector<std::string> GetSwitchValueStrings(
+      std::string_view switch_string) const;
+  std::vector<StringType> GetSwitchValuesNative(
+      std::string_view switch_string) const;
+
   // Get a copy of all switches, along with their values.
   const SwitchMap& GetSwitches() const { return switches_; }
 
   // Append a switch [with optional value] to the command line.
   // Note: Switches will precede arguments regardless of appending order.
+  //
+  // The version that takes an 8-bit switch value converts from UTF-8 on
+  // Windows.
   void AppendSwitch(const std::string& switch_string);
   void AppendSwitchPath(const std::string& switch_string, const FilePath& path);
   void AppendSwitchNative(const std::string& switch_string,
                           const StringType& value);
-  void AppendSwitchASCII(const std::string& switch_string,
-                         const std::string& value);
+  void AppendSwitch(const std::string& switch_string, const std::string& value);
 
   // Copy a set of switches (and any values) from another command line.
   // Commonly used when launching a subprocess.
diff --git a/gn/src/base/compiler_specific.h b/gn/src/base/compiler_specific.h
index ec139d26130..dd46c98b077 100644
--- a/gn/src/base/compiler_specific.h
+++ b/gn/src/base/compiler_specific.h
@@ -18,9 +18,9 @@
 
 #endif  // COMPILER_MSVC
 
-#if COMPILER_GCC && defined(NDEBUG)
+#if defined(COMPILER_GCC) && defined(NDEBUG)
 #define ALWAYS_INLINE inline __attribute__((__always_inline__))
-#elif COMPILER_MSVC && defined(NDEBUG)
+#elif defined(COMPILER_MSVC) && defined(NDEBUG)
 #define ALWAYS_INLINE __forceinline
 #else
 #define ALWAYS_INLINE inline
diff --git a/gn/src/base/files/file.cc b/gn/src/base/files/file.cc
index cecb76dba19..020c40f8d80 100644
--- a/gn/src/base/files/file.cc
+++ b/gn/src/base/files/file.cc
@@ -23,6 +23,14 @@ File::File(const FilePath& path, uint32_t flags)
   Initialize(path, flags);
 }
 
+File::File(ScopedPlatformFile platform_file)
+    : file_(std::move(platform_file)),
+      error_details_(FILE_OK) {
+#if defined(OS_POSIX) || defined(OS_FUCHSIA)
+  DCHECK_GE(file_.get(), -1);
+#endif
+}
+
 File::File(PlatformFile platform_file)
     : file_(platform_file),
       error_details_(FILE_OK) {
diff --git a/gn/src/base/files/file.h b/gn/src/base/files/file.h
index 2c94eb4eff7..419ba870b42 100644
--- a/gn/src/base/files/file.h
+++ b/gn/src/base/files/file.h
@@ -41,10 +41,12 @@ typedef struct stat64 stat_wrapper_t;
 class File {
  public:
   // FLAG_(OPEN|CREATE).* are mutually exclusive. You should specify exactly one
-  // of the five (possibly combining with other flags) when opening or creating
+  // of the three (possibly combining with other flags) when opening or creating
   // a file.
   enum Flags {
     FLAG_OPEN = 1 << 0,           // Opens a file, only if it exists.
+    FLAG_CREATE = 1 << 1,         // Creates a new file, only if it does not
+                                  // already exist.
     FLAG_CREATE_ALWAYS = 1 << 3,  // May overwrite an old file.
     FLAG_READ = 1 << 4,
     FLAG_WRITE = 1 << 5,
@@ -122,6 +124,7 @@ class File {
   File(const FilePath& path, uint32_t flags);
 
   // Takes ownership of |platform_file|.
+  explicit File(ScopedPlatformFile platform_file);
   explicit File(PlatformFile platform_file);
 
   // Creates an object with a specific error_details code.
diff --git a/gn/src/base/files/file_posix.cc b/gn/src/base/files/file_posix.cc
index b1f9f5e86f3..a1d256cb615 100644
--- a/gn/src/base/files/file_posix.cc
+++ b/gn/src/base/files/file_posix.cc
@@ -330,6 +330,8 @@ void File::DoInitialize(const FilePath& path, uint32_t flags) {
   DCHECK(!IsValid());
 
   int open_flags = 0;
+  if (flags & FLAG_CREATE)
+    open_flags = O_CREAT | O_EXCL;
 
   if (flags & FLAG_CREATE_ALWAYS) {
     DCHECK(!open_flags);
diff --git a/gn/src/base/files/file_util.h b/gn/src/base/files/file_util.h
index b44129d8fee..dbb69ec4a5a 100644
--- a/gn/src/base/files/file_util.h
+++ b/gn/src/base/files/file_util.h
@@ -124,6 +124,15 @@ bool ReadFileToStringWithMaxSize(const FilePath& path,
                                  std::string* contents,
                                  size_t max_size);
 
+#if defined(OS_POSIX) || defined(OS_FUCHSIA)
+
+// Performs the same function as CreateAndOpenTemporaryFileInDir(), but
+// returns the file-descriptor wrapped in a ScopedFD rather than a File.
+ScopedFD CreateAndOpenFdForTemporaryFileInDir(const FilePath& dir,
+                                              FilePath* path);
+
+#endif
+
 #if defined(OS_POSIX)
 
 // Creates a symbolic link at |symlink| pointing to |target|.  Returns
@@ -173,6 +182,10 @@ bool IsDirectoryEmpty(const FilePath& dir_path);
 // Get the temporary directory provided by the system.
 bool GetTempDir(FilePath* path);
 
+// Returns a new temporary file in |dir| with a unique name. On success,
+// |temp_file| is populated with the full path to the created file.
+File CreateAndOpenTemporaryFileInDir(const FilePath& dir, FilePath* temp_file);
+
 // Create a new directory. If prefix is provided, the new directory name is in
 // the format of prefixyyyy.
 // NOTE: prefix is ignored in the POSIX implementation.
diff --git a/gn/src/base/files/file_util_posix.cc b/gn/src/base/files/file_util_posix.cc
index ac281c44359..b6181511929 100644
--- a/gn/src/base/files/file_util_posix.cc
+++ b/gn/src/base/files/file_util_posix.cc
@@ -274,6 +274,16 @@ bool DirectoryExists(const FilePath& path) {
   return S_ISDIR(file_info.st_mode);
 }
 
+ScopedFD CreateAndOpenFdForTemporaryFileInDir(const FilePath& directory,
+                                              FilePath* path) {
+  *path = directory.Append(TempFileName());
+  const std::string& tmpdir_string = path->value();
+  // this should be OK since mkstemp just replaces characters in place
+  char* buffer = const_cast<char*>(tmpdir_string.c_str());
+
+  return ScopedFD(HANDLE_EINTR(mkstemp(buffer)));
+}
+
 #if !defined(OS_FUCHSIA)
 bool CreateSymbolicLink(const FilePath& target_path,
                         const FilePath& symlink_path) {
@@ -376,6 +386,11 @@ FilePath GetHomeDir() {
 }
 #endif  // !defined(OS_MACOSX)
 
+File CreateAndOpenTemporaryFileInDir(const FilePath& dir, FilePath* temp_file) {
+  ScopedFD fd = CreateAndOpenFdForTemporaryFileInDir(dir, temp_file);
+  return fd.is_valid() ? File(std::move(fd)) : File(File::GetLastFileError());
+}
+
 static bool CreateTemporaryDirInDirImpl(const FilePath& base_dir,
                                         const FilePath::StringType& name_tmpl,
                                         FilePath* new_dir) {
@@ -444,7 +459,7 @@ bool CreateDirectoryAndGetError(const FilePath& full_path, File::Error* error) {
        i != subpaths.rend(); ++i) {
     if (DirectoryExists(*i))
       continue;
-    if (mkdir(i->value().c_str(), 0700) == 0)
+    if (mkdir(i->value().c_str(), 0777) == 0)
       continue;
     // Mkdir failed, but it might have failed with EEXIST, or some other error
     // due to the the directory appearing out of thin air. This can occur if
diff --git a/gn/src/base/files/file_util_win.cc b/gn/src/base/files/file_util_win.cc
index 9f4bf5b4557..c808bdebcaa 100644
--- a/gn/src/base/files/file_util_win.cc
+++ b/gn/src/base/files/file_util_win.cc
@@ -283,6 +283,50 @@ bool GetTempDir(FilePath* path) {
   return true;
 }
 
+File CreateAndOpenTemporaryFileInDir(const FilePath& dir, FilePath* temp_file) {
+  constexpr uint32_t kFlags =
+      File::FLAG_CREATE | File::FLAG_READ | File::FLAG_WRITE;
+
+  // Use GUID instead of ::GetTempFileName() to generate unique file names.
+  // "Due to the algorithm used to generate file names, GetTempFileName can
+  // perform poorly when creating a large number of files with the same prefix.
+  // In such cases, it is recommended that you construct unique file names based
+  // on GUIDs."
+  // https://msdn.microsoft.com/library/windows/desktop/aa364991.aspx
+
+  FilePath temp_name;
+  File file;
+
+  // Although it is nearly impossible to get a duplicate name with GUID, we
+  // still use a loop here in case it happens.
+  for (int i = 0; i < 100; ++i) {
+    temp_name = dir.Append(
+        FilePath(UTF8ToUTF16(GenerateGUID()) + FILE_PATH_LITERAL(".tmp")));
+    file.Initialize(temp_name, kFlags);
+    if (file.IsValid())
+      break;
+  }
+
+  if (!file.IsValid()) {
+    DPLOG(WARNING) << "Failed to get temporary file name in "
+                   << UTF16ToUTF8(dir.value());
+    return file;
+  }
+
+  char16_t long_temp_name[MAX_PATH + 1];
+  const DWORD long_name_len = GetLongPathName(
+      ToWCharT(temp_name.value().c_str()), ToWCharT(long_temp_name), MAX_PATH);
+  if (long_name_len != 0 && long_name_len <= MAX_PATH) {
+    *temp_file =
+        FilePath(FilePath::StringViewType(long_temp_name, long_name_len));
+  } else {
+    // GetLongPathName() failed, but we still have a temporary file.
+    *temp_file = std::move(temp_name);
+  }
+
+  return file;
+}
+
 bool CreateTemporaryDirInDir(const FilePath& base_dir,
                              const FilePath::StringType& prefix,
                              FilePath* new_dir) {
diff --git a/gn/src/base/files/file_win.cc b/gn/src/base/files/file_win.cc
index b68370b84b4..c58e071f067 100644
--- a/gn/src/base/files/file_win.cc
+++ b/gn/src/base/files/file_win.cc
@@ -274,6 +274,11 @@ void File::DoInitialize(const FilePath& path, uint32_t flags) {
   if (flags & FLAG_OPEN)
     disposition = OPEN_EXISTING;
 
+  if (flags & FLAG_CREATE) {
+    DCHECK(!disposition);
+    disposition = CREATE_NEW;
+  }
+
   if (flags & FLAG_CREATE_ALWAYS) {
     DCHECK(!disposition);
     DCHECK(flags & FLAG_WRITE);
diff --git a/gn/src/base/logging.cc b/gn/src/base/logging.cc
index c8673e4fe96..e8929c17da2 100644
--- a/gn/src/base/logging.cc
+++ b/gn/src/base/logging.cc
@@ -77,7 +77,7 @@ const int kAlwaysPrintErrorLevel = LOG_ERROR;
 
 }  // namespace
 
-#if DCHECK_IS_CONFIGURABLE
+#if defined(DCHECK_IS_CONFIGURABLE)
 // In DCHECK-enabled Chrome builds, allow the meaning of LOG_DCHECK to be
 // determined at run-time. We default it to INFO, to avoid it triggering
 // crashes before the run-time has explicitly chosen the behaviour.
diff --git a/gn/src/base/logging.h b/gn/src/base/logging.h
index 2b1af7ff4f5..18f827f04f2 100644
--- a/gn/src/base/logging.h
+++ b/gn/src/base/logging.h
@@ -607,7 +607,7 @@ DEFINE_CHECK_OP_IMPL(GT, >)
 
 #if DCHECK_IS_ON()
 
-#if DCHECK_IS_CONFIGURABLE
+#if defined(DCHECK_IS_CONFIGURABLE)
 extern LogSeverity LOG_DCHECK;
 #else
 const LogSeverity LOG_DCHECK = LOG_FATAL;
diff --git a/gn/src/base/numerics/clamped_math.h b/gn/src/base/numerics/clamped_math.h
index 9e8354353a6..88e0e3afc03 100644
--- a/gn/src/base/numerics/clamped_math.h
+++ b/gn/src/base/numerics/clamped_math.h
@@ -233,12 +233,12 @@ BASE_NUMERIC_ARITHMETIC_OPERATORS(Clamped, Clamp, Or, |, |=)
 BASE_NUMERIC_ARITHMETIC_OPERATORS(Clamped, Clamp, Xor, ^, ^=)
 BASE_NUMERIC_ARITHMETIC_VARIADIC(Clamped, Clamp, Max)
 BASE_NUMERIC_ARITHMETIC_VARIADIC(Clamped, Clamp, Min)
-BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsLess, <);
-BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsLessOrEqual, <=);
-BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsGreater, >);
-BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsGreaterOrEqual, >=);
-BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsEqual, ==);
-BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsNotEqual, !=);
+BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsLess, <)
+BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsLessOrEqual, <=)
+BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsGreater, >)
+BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsGreaterOrEqual, >=)
+BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsEqual, ==)
+BASE_NUMERIC_COMPARISON_OPERATORS(Clamped, IsNotEqual, !=)
 
 }  // namespace internal
 
diff --git a/gn/src/base/numerics/safe_conversions.h b/gn/src/base/numerics/safe_conversions.h
index 35c40897862..32fb5a92633 100644
--- a/gn/src/base/numerics/safe_conversions.h
+++ b/gn/src/base/numerics/safe_conversions.h
@@ -310,14 +310,14 @@ std::ostream& operator<<(std::ostream& os, const StrictNumeric<T>& value) {
                        typename UnderlyingType<R>::type>(lhs, rhs);     \
   }
 
-BASE_NUMERIC_COMPARISON_OPERATORS(Strict, IsLess, <);
-BASE_NUMERIC_COMPARISON_OPERATORS(Strict, IsLessOrEqual, <=);
-BASE_NUMERIC_COMPARISON_OPERATORS(Strict, IsGreater, >);
-BASE_NUMERIC_COMPARISON_OPERATORS(Strict, IsGreaterOrEqual, >=);
-BASE_NUMERIC_COMPARISON_OPERATORS(Strict, IsEqual, ==);
-BASE_NUMERIC_COMPARISON_OPERATORS(Strict, IsNotEqual, !=);
-
-};  // namespace internal
+BASE_NUMERIC_COMPARISON_OPERATORS(Strict, IsLess, <)
+BASE_NUMERIC_COMPARISON_OPERATORS(Strict, IsLessOrEqual, <=)
+BASE_NUMERIC_COMPARISON_OPERATORS(Strict, IsGreater, >)
+BASE_NUMERIC_COMPARISON_OPERATORS(Strict, IsGreaterOrEqual, >=)
+BASE_NUMERIC_COMPARISON_OPERATORS(Strict, IsEqual, ==)
+BASE_NUMERIC_COMPARISON_OPERATORS(Strict, IsNotEqual, !=)
+
+}  // namespace internal
 
 using internal::as_signed;
 using internal::as_unsigned;
diff --git a/gn/src/base/third_party/icu/README.chromium b/gn/src/base/third_party/icu/README.chromium
index 297e89a2edd..4f398d9fa9c 100644
--- a/gn/src/base/third_party/icu/README.chromium
+++ b/gn/src/base/third_party/icu/README.chromium
@@ -6,12 +6,12 @@ License File: NOT_SHIPPED
 
 This file has the relevant components from ICU copied to handle basic UTF8/16/32
 conversions. Components are copied from umachine.h, utf.h, utf8.h, and utf16.h
-into icu_utf.h, and from utf_impl.cpp into icu_utf.cc.
+into icu_utf.h.
 
-The main change is that U_/U8_/U16_ prefixes have been replaced with
-CBU_/CBU8_/CBU16_ (for "Chrome Base") to avoid confusion with the "real" ICU
-macros should ICU be in use on the system. For the same reason, the functions
-and types have been put in the "base_icu" namespace.
+The main change is that U_/U8_/U16_/UPRV_ prefixes have been replaced with
+CBU_/CBU8_/CBU16_/CBUPRV_ (for "Chrome Base") to avoid confusion with the "real"
+ICU macros should ICU be in use on the system. For the same reason, the
+functions and types have been put in the "base_icu" namespace.
 
 Note that this license file is marked as NOT_SHIPPED, since a more complete
 ICU license is included from //third_party/icu/README.chromium
diff --git a/gn/src/base/third_party/icu/icu_utf.cc b/gn/src/base/third_party/icu/icu_utf.cc
deleted file mode 100644
index 8dcb401fd9a..00000000000
--- a/gn/src/base/third_party/icu/icu_utf.cc
+++ /dev/null
@@ -1,129 +0,0 @@
-// © 2016 and later: Unicode, Inc. and others.
-// License & terms of use: http://www.unicode.org/copyright.html
-/*
-******************************************************************************
-*
-*   Copyright (C) 1999-2012, International Business Machines
-*   Corporation and others.  All Rights Reserved.
-*
-******************************************************************************
-*   file name:  utf_impl.cpp
-*   encoding:   UTF-8
-*   tab size:   8 (not used)
-*   indentation:4
-*
-*   created on: 1999sep13
-*   created by: Markus W. Scherer
-*
-*   This file provides implementation functions for macros in the utfXX.h
-*   that would otherwise be too long as macros.
-*/
-
-#include "base/third_party/icu/icu_utf.h"
-
-namespace base_icu {
-
-// source/common/utf_impl.cpp
-
-static const UChar32 utf8_errorValue[6] = {
-    // Same values as UTF8_ERROR_VALUE_1, UTF8_ERROR_VALUE_2, UTF_ERROR_VALUE,
-    // but without relying on the obsolete unicode/utf_old.h.
-    0x15, 0x9f, 0xffff, 0x10ffff};
-
-static UChar32 errorValue(int32_t count, int8_t strict) {
-  if (strict >= 0) {
-    return utf8_errorValue[count];
-  } else if (strict == -3) {
-    return 0xfffd;
-  } else {
-    return CBU_SENTINEL;
-  }
-}
-
-/*
- * Handle the non-inline part of the U8_NEXT() and U8_NEXT_FFFD() macros
- * and their obsolete sibling UTF8_NEXT_CHAR_SAFE().
- *
- * U8_NEXT() supports NUL-terminated strings indicated via length<0.
- *
- * The "strict" parameter controls the error behavior:
- * <0  "Safe" behavior of U8_NEXT():
- *     -1: All illegal byte sequences yield U_SENTINEL=-1.
- *     -2: Same as -1, except for lenient treatment of surrogate code points as
- * legal. Some implementations use this for roundtripping of Unicode 16-bit
- * strings that are not well-formed UTF-16, that is, they contain
- * unpaired surrogates. -3: All illegal byte sequences yield U+FFFD. 0
- * Obsolete "safe" behavior of UTF8_NEXT_CHAR_SAFE(..., FALSE): All illegal
- * byte sequences yield a positive code point such that this result code
- * point would be encoded with the same number of bytes as the illegal
- * sequence. >0  Obsolete "strict" behavior of UTF8_NEXT_CHAR_SAFE(...,
- * TRUE): Same as the obsolete "safe" behavior, but non-characters are also
- * treated like illegal sequences.
- *
- * Note that a UBool is the same as an int8_t.
- */
-UChar32 utf8_nextCharSafeBody(const uint8_t* s,
-                              int32_t* pi,
-                              int32_t length,
-                              UChar32 c,
-                              UBool strict) {
-  // *pi is one after byte c.
-  int32_t i = *pi;
-  // length can be negative for NUL-terminated strings: Read and validate one
-  // byte at a time.
-  if (i == length || c > 0xf4) {
-    // end of string, or not a lead byte
-  } else if (c >= 0xf0) {
-    // Test for 4-byte sequences first because
-    // U8_NEXT() handles shorter valid sequences inline.
-    uint8_t t1 = s[i], t2, t3;
-    c &= 7;
-    if (CBU8_IS_VALID_LEAD4_AND_T1(c, t1) && ++i != length &&
-        (t2 = s[i] - 0x80) <= 0x3f && ++i != length &&
-        (t3 = s[i] - 0x80) <= 0x3f) {
-      ++i;
-      c = (c << 18) | ((t1 & 0x3f) << 12) | (t2 << 6) | t3;
-      // strict: forbid non-characters like U+fffe
-      if (strict <= 0 || !CBU_IS_UNICODE_NONCHAR(c)) {
-        *pi = i;
-        return c;
-      }
-    }
-  } else if (c >= 0xe0) {
-    c &= 0xf;
-    if (strict != -2) {
-      uint8_t t1 = s[i], t2;
-      if (CBU8_IS_VALID_LEAD3_AND_T1(c, t1) && ++i != length &&
-          (t2 = s[i] - 0x80) <= 0x3f) {
-        ++i;
-        c = (c << 12) | ((t1 & 0x3f) << 6) | t2;
-        // strict: forbid non-characters like U+fffe
-        if (strict <= 0 || !CBU_IS_UNICODE_NONCHAR(c)) {
-          *pi = i;
-          return c;
-        }
-      }
-    } else {
-      // strict=-2 -> lenient: allow surrogates
-      uint8_t t1 = s[i] - 0x80, t2;
-      if (t1 <= 0x3f && (c > 0 || t1 >= 0x20) && ++i != length &&
-          (t2 = s[i] - 0x80) <= 0x3f) {
-        *pi = i + 1;
-        return (c << 12) | (t1 << 6) | t2;
-      }
-    }
-  } else if (c >= 0xc2) {
-    uint8_t t1 = s[i] - 0x80;
-    if (t1 <= 0x3f) {
-      *pi = i + 1;
-      return ((c - 0xc0) << 6) | t1;
-    }
-  }  // else 0x80<=c<0xc2 is not a lead byte
-
-  /* error handling */
-  c = errorValue(i - *pi, strict);
-  *pi = i;
-  return c;
-}
-
-}  // namespace base_icu
diff --git a/gn/src/base/third_party/icu/icu_utf.h b/gn/src/base/third_party/icu/icu_utf.h
index b626b398404..16792c49040 100644
--- a/gn/src/base/third_party/icu/icu_utf.h
+++ b/gn/src/base/third_party/icu/icu_utf.h
@@ -60,6 +60,25 @@ typedef int32_t UChar32;
  */
 #define CBU_SENTINEL (-1)
 
+/**
+ * \def UPRV_BLOCK_MACRO_BEGIN
+ * Defined as the "do" keyword by default.
+ * @internal
+ */
+#ifndef CBUPRV_BLOCK_MACRO_BEGIN
+#define CBUPRV_BLOCK_MACRO_BEGIN do
+#endif
+
+/**
+ * \def UPRV_BLOCK_MACRO_END
+ * Defined as "while (FALSE)" by default.
+ * @internal
+ */
+#ifndef CBUPRV_BLOCK_MACRO_END
+#define CBUPRV_BLOCK_MACRO_END while (0)
+#endif
+
+
 // source/common/unicode/utf.h
 
 /**
@@ -68,9 +87,9 @@ typedef int32_t UChar32;
  * @return TRUE or FALSE
  * @stable ICU 2.4
  */
-#define CBU_IS_UNICODE_NONCHAR(c)                                \
-  ((c) >= 0xfdd0 && ((c) <= 0xfdef || ((c)&0xfffe) == 0xfffe) && \
-   (c) <= 0x10ffff)
+#define CBU_IS_UNICODE_NONCHAR(c) \
+    ((c)>=0xfdd0 && \
+     ((c)<=0xfdef || ((c)&0xfffe)==0xfffe) && (c)<=0x10ffff)
 
 /**
  * Is c a Unicode code point value (0..U+10ffff)
@@ -78,9 +97,9 @@ typedef int32_t UChar32;
  *
  * Code points that are not characters include:
  * - single surrogate code points (U+d800..U+dfff, 2048 code points)
- * - the last two code points on each plane (U+__fffe and U+__ffff, 34 code
- * points) - U+fdd0..U+fdef (new with Unicode 3.1, 32 code points) - the highest
- * Unicode code point value is U+10ffff
+ * - the last two code points on each plane (U+__fffe and U+__ffff, 34 code points)
+ * - U+fdd0..U+fdef (new with Unicode 3.1, 32 code points)
+ * - the highest Unicode code point value is U+10ffff
  *
  * This means that all code points below U+d800 are character code points,
  * and that boundary is tested first for performance.
@@ -90,8 +109,8 @@ typedef int32_t UChar32;
  * @stable ICU 2.4
  */
 #define CBU_IS_UNICODE_CHAR(c) \
-  ((uint32_t)(c) < 0xd800 ||   \
-   (0xdfff < (c) && (c) <= 0x10ffff && !CBU_IS_UNICODE_NONCHAR(c)))
+    ((uint32_t)(c)<0xd800 || \
+        (0xdfff<(c) && (c)<=0x10ffff && !CBU_IS_UNICODE_NONCHAR(c)))
 
 /**
  * Is this code point a surrogate (U+d800..U+dfff)?
@@ -99,7 +118,7 @@ typedef int32_t UChar32;
  * @return TRUE or FALSE
  * @stable ICU 2.4
  */
-#define CBU_IS_SURROGATE(c) (((c)&0xfffff800) == 0xd800)
+#define CBU_IS_SURROGATE(c) (((c)&0xfffff800)==0xd800)
 
 /**
  * Assuming c is a surrogate code point (U_IS_SURROGATE(c)),
@@ -108,69 +127,43 @@ typedef int32_t UChar32;
  * @return TRUE or FALSE
  * @stable ICU 2.4
  */
-#define CBU_IS_SURROGATE_LEAD(c) (((c)&0x400) == 0)
+#define CBU_IS_SURROGATE_LEAD(c) (((c)&0x400)==0)
 
 // source/common/unicode/utf8.h
 
 /**
- * Internal bit vector for 3-byte UTF-8 validity check, for use in
- * U8_IS_VALID_LEAD3_AND_T1. Each bit indicates whether one lead byte + first
- * trail byte pair starts a valid sequence. Lead byte E0..EF bits 3..0 are used
- * as byte index, first trail byte bits 7..5 are used as bit index into that
- * byte.
+ * Internal bit vector for 3-byte UTF-8 validity check, for use in U8_IS_VALID_LEAD3_AND_T1.
+ * Each bit indicates whether one lead byte + first trail byte pair starts a valid sequence.
+ * Lead byte E0..EF bits 3..0 are used as byte index,
+ * first trail byte bits 7..5 are used as bit index into that byte.
  * @see U8_IS_VALID_LEAD3_AND_T1
  * @internal
  */
-#define CBU8_LEAD3_T1_BITS \
-  "\x20\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x10\x30\x30"
+#define CBU8_LEAD3_T1_BITS "\x20\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x30\x10\x30\x30"
 
 /**
  * Internal 3-byte UTF-8 validity check.
- * Non-zero if lead byte E0..EF and first trail byte 00..FF start a valid
- * sequence.
+ * Non-zero if lead byte E0..EF and first trail byte 00..FF start a valid sequence.
  * @internal
  */
-#define CBU8_IS_VALID_LEAD3_AND_T1(lead, t1) \
-  (CBU8_LEAD3_T1_BITS[(lead)&0xf] & (1 << ((uint8_t)(t1) >> 5)))
+#define CBU8_IS_VALID_LEAD3_AND_T1(lead, t1) (CBU8_LEAD3_T1_BITS[(lead)&0xf]&(1<<((uint8_t)(t1)>>5)))
 
 /**
- * Internal bit vector for 4-byte UTF-8 validity check, for use in
- * U8_IS_VALID_LEAD4_AND_T1. Each bit indicates whether one lead byte + first
- * trail byte pair starts a valid sequence. First trail byte bits 7..4 are used
- * as byte index, lead byte F0..F4 bits 2..0 are used as bit index into that
- * byte.
+ * Internal bit vector for 4-byte UTF-8 validity check, for use in U8_IS_VALID_LEAD4_AND_T1.
+ * Each bit indicates whether one lead byte + first trail byte pair starts a valid sequence.
+ * First trail byte bits 7..4 are used as byte index,
+ * lead byte F0..F4 bits 2..0 are used as bit index into that byte.
  * @see U8_IS_VALID_LEAD4_AND_T1
  * @internal
  */
-#define CBU8_LEAD4_T1_BITS \
-  "\x00\x00\x00\x00\x00\x00\x00\x00\x1E\x0F\x0F\x0F\x00\x00\x00\x00"
+#define CBU8_LEAD4_T1_BITS "\x00\x00\x00\x00\x00\x00\x00\x00\x1E\x0F\x0F\x0F\x00\x00\x00\x00"
 
 /**
  * Internal 4-byte UTF-8 validity check.
- * Non-zero if lead byte F0..F4 and first trail byte 00..FF start a valid
- * sequence.
- * @internal
- */
-#define CBU8_IS_VALID_LEAD4_AND_T1(lead, t1) \
-  (CBU8_LEAD4_T1_BITS[(uint8_t)(t1) >> 4] & (1 << ((lead)&7)))
-
-/**
- * Function for handling "next code point" with error-checking.
- *
- * This is internal since it is not meant to be called directly by external clie
-nts;
- * however it is U_STABLE (not U_INTERNAL) since it is called by public macros i
-n this
- * file and thus must remain stable, and should not be hidden when other interna
-l
- * functions are hidden (otherwise public macros would fail to compile).
+ * Non-zero if lead byte F0..F4 and first trail byte 00..FF start a valid sequence.
  * @internal
  */
-UChar32 utf8_nextCharSafeBody(const uint8_t* s,
-                              int32_t* pi,
-                              int32_t length,
-                              ::base_icu::UChar32 c,
-                              ::base_icu::UBool strict);
+#define CBU8_IS_VALID_LEAD4_AND_T1(lead, t1) (CBU8_LEAD4_T1_BITS[(uint8_t)(t1)>>4]&(1<<((lead)&7)))
 
 /**
  * Does this code unit (byte) encode a code point by itself (US-ASCII 0..0x7f)?
@@ -178,7 +171,7 @@ UChar32 utf8_nextCharSafeBody(const uint8_t* s,
  * @return TRUE or FALSE
  * @stable ICU 2.4
  */
-#define CBU8_IS_SINGLE(c) (((c)&0x80) == 0)
+#define CBU8_IS_SINGLE(c) (((c)&0x80)==0)
 
 /**
  * Is this code unit (byte) a UTF-8 lead byte? (0xC2..0xF4)
@@ -186,7 +179,7 @@ UChar32 utf8_nextCharSafeBody(const uint8_t* s,
  * @return TRUE or FALSE
  * @stable ICU 2.4
  */
-#define CBU8_IS_LEAD(c) ((uint8_t)((c)-0xc2) <= 0x32)
+#define CBU8_IS_LEAD(c) ((uint8_t)((c)-0xc2)<=0x32)
 
 /**
  * Is this code unit (byte) a UTF-8 trail byte? (0x80..0xBF)
@@ -194,7 +187,7 @@ UChar32 utf8_nextCharSafeBody(const uint8_t* s,
  * @return TRUE or FALSE
  * @stable ICU 2.4
  */
-#define CBU8_IS_TRAIL(c) ((int8_t)(c) < -0x40)
+#define CBU8_IS_TRAIL(c) ((int8_t)(c)<-0x40)
 
 /**
  * How many code units (bytes) are used for the UTF-8 encoding
@@ -203,20 +196,19 @@ UChar32 utf8_nextCharSafeBody(const uint8_t* s,
  * @return 1..4, or 0 if c is a surrogate or not a Unicode code point
  * @stable ICU 2.4
  */
-#define CBU8_LENGTH(c)                                                      \
-  ((uint32_t)(c) <= 0x7f                                                    \
-       ? 1                                                                  \
-       : ((uint32_t)(c) <= 0x7ff                                            \
-              ? 2                                                           \
-              : ((uint32_t)(c) <= 0xd7ff                                    \
-                     ? 3                                                    \
-                     : ((uint32_t)(c) <= 0xdfff || (uint32_t)(c) > 0x10ffff \
-                            ? 0                                             \
-                            : ((uint32_t)(c) <= 0xffff ? 3 : 4)))))
+#define CBU8_LENGTH(c) \
+    ((uint32_t)(c)<=0x7f ? 1 : \
+        ((uint32_t)(c)<=0x7ff ? 2 : \
+            ((uint32_t)(c)<=0xd7ff ? 3 : \
+                ((uint32_t)(c)<=0xdfff || (uint32_t)(c)>0x10ffff ? 0 : \
+                    ((uint32_t)(c)<=0xffff ? 3 : 4)\
+                ) \
+            ) \
+        ) \
+    )
 
 /**
- * The maximum number of UTF-8 code units (bytes) per Unicode code point
- * (U+0000..U+10ffff).
+ * The maximum number of UTF-8 code units (bytes) per Unicode code point (U+0000..U+10ffff).
  * @return 4
  * @stable ICU 2.4
  */
@@ -242,37 +234,43 @@ UChar32 utf8_nextCharSafeBody(const uint8_t* s,
  * @see U8_NEXT_UNSAFE
  * @stable ICU 2.4
  */
-#define CBU8_NEXT(s, i, length, c)                                       \
-  {                                                                      \
-    (c) = (uint8_t)(s)[(i)++];                                           \
-    if (!CBU8_IS_SINGLE(c)) {                                            \
-      uint8_t __t1, __t2;                                                \
-      if (/* handle U+0800..U+FFFF inline */                             \
-          (0xe0 <= (c) && (c) < 0xf0) &&                                 \
-          (((i) + 1) < (length) || (length) < 0) &&                      \
-          CBU8_IS_VALID_LEAD3_AND_T1((c), __t1 = (s)[i]) &&              \
-          (__t2 = (s)[(i) + 1] - 0x80) <= 0x3f) {                        \
-        (c) = (((c)&0xf) << 12) | ((__t1 & 0x3f) << 6) | __t2;           \
-        (i) += 2;                                                        \
-      } else if (/* handle U+0080..U+07FF inline */                      \
-                 ((c) < 0xe0 && (c) >= 0xc2) && ((i) != (length)) &&     \
-                 (__t1 = (s)[i] - 0x80) <= 0x3f) {                       \
-        (c) = (((c)&0x1f) << 6) | __t1;                                  \
-        ++(i);                                                           \
-      } else {                                                           \
-        /* function call for "complicated" and error cases */            \
-        (c) = ::base_icu::utf8_nextCharSafeBody((const uint8_t*)s, &(i), \
-                                                (length), c, -1);        \
-      }                                                                  \
-    }                                                                    \
-  }
+#define CBU8_NEXT(s, i, length, c) CBU8_INTERNAL_NEXT_OR_SUB(s, i, length, c, CBU_SENTINEL)
+
+/** @internal */
+#define CBU8_INTERNAL_NEXT_OR_SUB(s, i, length, c, sub) CBUPRV_BLOCK_MACRO_BEGIN { \
+    (c)=(uint8_t)(s)[(i)++]; \
+    if(!CBU8_IS_SINGLE(c)) { \
+        uint8_t __t = 0; \
+        if((i)!=(length) && \
+            /* fetch/validate/assemble all but last trail byte */ \
+            ((c)>=0xe0 ? \
+                ((c)<0xf0 ?  /* U+0800..U+FFFF except surrogates */ \
+                    CBU8_LEAD3_T1_BITS[(c)&=0xf]&(1<<((__t=(s)[i])>>5)) && \
+                    (__t&=0x3f, 1) \
+                :  /* U+10000..U+10FFFF */ \
+                    ((c)-=0xf0)<=4 && \
+                    CBU8_LEAD4_T1_BITS[(__t=(s)[i])>>4]&(1<<(c)) && \
+                    ((c)=((c)<<6)|(__t&0x3f), ++(i)!=(length)) && \
+                    (__t=(s)[i]-0x80)<=0x3f) && \
+                /* valid second-to-last trail byte */ \
+                ((c)=((c)<<6)|__t, ++(i)!=(length)) \
+            :  /* U+0080..U+07FF */ \
+                (c)>=0xc2 && ((c)&=0x1f, 1)) && \
+            /* last trail byte */ \
+            (__t=(s)[i]-0x80)<=0x3f && \
+            ((c)=((c)<<6)|__t, ++(i), 1)) { \
+        } else { \
+            (c)=(sub);  /* ill-formed*/ \
+        } \
+    } \
+} CBUPRV_BLOCK_MACRO_END
 
 /**
  * Append a code point to a string, overwriting 1 to 4 bytes.
  * The offset points to the current end of the string contents
  * and is advanced (post-increment).
- * "Unsafe" macro, assumes a valid code point and sufficient space in the
- * string. Otherwise, the result is undefined.
+ * "Unsafe" macro, assumes a valid code point and sufficient space in the string.
+ * Otherwise, the result is undefined.
  *
  * @param s const uint8_t * string buffer
  * @param i string offset
@@ -280,25 +278,25 @@ UChar32 utf8_nextCharSafeBody(const uint8_t* s,
  * @see U8_APPEND
  * @stable ICU 2.4
  */
-#define CBU8_APPEND_UNSAFE(s, i, c)                            \
-  {                                                            \
-    if ((uint32_t)(c) <= 0x7f) {                               \
-      (s)[(i)++] = (uint8_t)(c);                               \
-    } else {                                                   \
-      if ((uint32_t)(c) <= 0x7ff) {                            \
-        (s)[(i)++] = (uint8_t)(((c) >> 6) | 0xc0);             \
-      } else {                                                 \
-        if ((uint32_t)(c) <= 0xffff) {                         \
-          (s)[(i)++] = (uint8_t)(((c) >> 12) | 0xe0);          \
-        } else {                                               \
-          (s)[(i)++] = (uint8_t)(((c) >> 18) | 0xf0);          \
-          (s)[(i)++] = (uint8_t)((((c) >> 12) & 0x3f) | 0x80); \
-        }                                                      \
-        (s)[(i)++] = (uint8_t)((((c) >> 6) & 0x3f) | 0x80);    \
-      }                                                        \
-      (s)[(i)++] = (uint8_t)(((c)&0x3f) | 0x80);               \
-    }                                                          \
-  }
+#define CBU8_APPEND_UNSAFE(s, i, c) CBUPRV_BLOCK_MACRO_BEGIN { \
+    uint32_t __uc=(c); \
+    if(__uc<=0x7f) { \
+        (s)[(i)++]=(uint8_t)__uc; \
+    } else { \
+        if(__uc<=0x7ff) { \
+            (s)[(i)++]=(uint8_t)((__uc>>6)|0xc0); \
+        } else { \
+            if(__uc<=0xffff) { \
+                (s)[(i)++]=(uint8_t)((__uc>>12)|0xe0); \
+            } else { \
+                (s)[(i)++]=(uint8_t)((__uc>>18)|0xf0); \
+                (s)[(i)++]=(uint8_t)(((__uc>>12)&0x3f)|0x80); \
+            } \
+            (s)[(i)++]=(uint8_t)(((__uc>>6)&0x3f)|0x80); \
+        } \
+        (s)[(i)++]=(uint8_t)((__uc&0x3f)|0x80); \
+    } \
+} CBUPRV_BLOCK_MACRO_END
 
 // source/common/unicode/utf16.h
 
@@ -316,7 +314,7 @@ UChar32 utf8_nextCharSafeBody(const uint8_t* s,
  * @return TRUE or FALSE
  * @stable ICU 2.4
  */
-#define CBU16_IS_LEAD(c) (((c)&0xfffffc00) == 0xd800)
+#define CBU16_IS_LEAD(c) (((c)&0xfffffc00)==0xd800)
 
 /**
  * Is this code unit a trail surrogate (U+dc00..U+dfff)?
@@ -324,7 +322,7 @@ UChar32 utf8_nextCharSafeBody(const uint8_t* s,
  * @return TRUE or FALSE
  * @stable ICU 2.4
  */
-#define CBU16_IS_TRAIL(c) (((c)&0xfffffc00) == 0xdc00)
+#define CBU16_IS_TRAIL(c) (((c)&0xfffffc00)==0xdc00)
 
 /**
  * Is this code unit a surrogate (U+d800..U+dfff)?
@@ -341,13 +339,13 @@ UChar32 utf8_nextCharSafeBody(const uint8_t* s,
  * @return TRUE or FALSE
  * @stable ICU 2.4
  */
-#define CBU16_IS_SURROGATE_LEAD(c) (((c)&0x400) == 0)
+#define CBU16_IS_SURROGATE_LEAD(c) (((c)&0x400)==0)
 
 /**
  * Helper constant for U16_GET_SUPPLEMENTARY.
  * @internal
  */
-#define CBU16_SURROGATE_OFFSET ((0xd800 << 10UL) + 0xdc00 - 0x10000)
+#define CBU16_SURROGATE_OFFSET ((0xd800<<10UL)+0xdc00-0x10000)
 
 /**
  * Get a supplementary code point value (U+10000..U+10ffff)
@@ -361,8 +359,7 @@ UChar32 utf8_nextCharSafeBody(const uint8_t* s,
  * @stable ICU 2.4
  */
 #define CBU16_GET_SUPPLEMENTARY(lead, trail) \
-  (((::base_icu::UChar32)(lead) << 10UL) +   \
-   (::base_icu::UChar32)(trail)-CBU16_SURROGATE_OFFSET)
+    (((::base_icu::UChar32)(lead)<<10UL)+(::base_icu::UChar32)(trail)-CBU16_SURROGATE_OFFSET)
 
 /**
  * Get the lead surrogate (0xd800..0xdbff) for a
@@ -371,8 +368,7 @@ UChar32 utf8_nextCharSafeBody(const uint8_t* s,
  * @return lead surrogate (U+d800..U+dbff) for supplementary
  * @stable ICU 2.4
  */
-#define CBU16_LEAD(supplementary) \
-  (::base_icu::UChar)(((supplementary) >> 10) + 0xd7c0)
+#define CBU16_LEAD(supplementary) (::base_icu::UChar)(((supplementary)>>10)+0xd7c0)
 
 /**
  * Get the trail surrogate (0xdc00..0xdfff) for a
@@ -381,28 +377,64 @@ UChar32 utf8_nextCharSafeBody(const uint8_t* s,
  * @return trail surrogate (U+dc00..U+dfff) for supplementary
  * @stable ICU 2.4
  */
-#define CBU16_TRAIL(supplementary) \
-  (::base_icu::UChar)(((supplementary)&0x3ff) | 0xdc00)
+#define CBU16_TRAIL(supplementary) (::base_icu::UChar)(((supplementary)&0x3ff)|0xdc00)
 
 /**
- * How many 16-bit code units are used to encode this Unicode code point? (1 or
- * 2) The result is not defined if c is not a Unicode code point
- * (U+0000..U+10ffff).
+ * How many 16-bit code units are used to encode this Unicode code point? (1 or 2)
+ * The result is not defined if c is not a Unicode code point (U+0000..U+10ffff).
  * @param c 32-bit code point
  * @return 1 or 2
  * @stable ICU 2.4
  */
-#define CBU16_LENGTH(c) ((uint32_t)(c) <= 0xffff ? 1 : 2)
+#define CBU16_LENGTH(c) ((uint32_t)(c)<=0xffff ? 1 : 2)
 
 /**
- * The maximum number of 16-bit code units per Unicode code point
- * (U+0000..U+10ffff).
+ * The maximum number of 16-bit code units per Unicode code point (U+0000..U+10ffff).
  * @return 2
  * @stable ICU 2.4
  */
 #define CBU16_MAX_LENGTH 2
 
 /**
+ * Get a code point from a string at a random-access offset,
+ * without changing the offset.
+ * "Safe" macro, handles unpaired surrogates and checks for string boundaries.
+ *
+ * The offset may point to either the lead or trail surrogate unit
+ * for a supplementary code point, in which case the macro will read
+ * the adjacent matching surrogate as well.
+ *
+ * The length can be negative for a NUL-terminated string.
+ *
+ * If the offset points to a single, unpaired surrogate, then
+ * c is set to that unpaired surrogate.
+ * Iteration through a string is more efficient with U16_NEXT_UNSAFE or U16_NEXT.
+ *
+ * @param s const UChar * string
+ * @param start starting string offset (usually 0)
+ * @param i string offset, must be start<=i<length
+ * @param length string length
+ * @param c output UChar32 variable
+ * @see U16_GET_UNSAFE
+ * @stable ICU 2.4
+ */
+#define CBU16_GET(s, start, i, length, c) CBUPRV_BLOCK_MACRO_BEGIN { \
+    (c)=(s)[i]; \
+    if(CBU16_IS_SURROGATE(c)) { \
+        uint16_t __c2; \
+        if(CBU16_IS_SURROGATE_LEAD(c)) { \
+            if((i)+1!=(length) && CBU16_IS_TRAIL(__c2=(s)[(i)+1])) { \
+                (c)=CBU16_GET_SUPPLEMENTARY((c), __c2); \
+            } \
+        } else { \
+            if((i)>(start) && CBU16_IS_LEAD(__c2=(s)[(i)-1])) { \
+                (c)=CBU16_GET_SUPPLEMENTARY(__c2, (c)); \
+            } \
+        } \
+    } \
+} CBUPRV_BLOCK_MACRO_END
+
+/**
  * Get a code point from a string at a code point boundary offset,
  * and advance the offset to the next code point boundary.
  * (Post-incrementing forward iteration.)
@@ -414,8 +446,7 @@ UChar32 utf8_nextCharSafeBody(const uint8_t* s,
  * for a supplementary code point, in which case the macro will read
  * the following trail surrogate as well.
  * If the offset points to a trail surrogate or
- * to a single, unpaired lead surrogate, then c is set to that unpaired
- * surrogate.
+ * to a single, unpaired lead surrogate, then c is set to that unpaired surrogate.
  *
  * @param s const UChar * string
  * @param i string offset, must be i<length
@@ -424,24 +455,23 @@ UChar32 utf8_nextCharSafeBody(const uint8_t* s,
  * @see U16_NEXT_UNSAFE
  * @stable ICU 2.4
  */
-#define CBU16_NEXT(s, i, length, c)                             \
-  {                                                             \
-    (c) = (s)[(i)++];                                           \
-    if (CBU16_IS_LEAD(c)) {                                     \
-      uint16_t __c2;                                            \
-      if ((i) != (length) && CBU16_IS_TRAIL(__c2 = (s)[(i)])) { \
-        ++(i);                                                  \
-        (c) = CBU16_GET_SUPPLEMENTARY((c), __c2);               \
-      }                                                         \
-    }                                                           \
-  }
+#define CBU16_NEXT(s, i, length, c) CBUPRV_BLOCK_MACRO_BEGIN { \
+    (c)=(s)[(i)++]; \
+    if(CBU16_IS_LEAD(c)) { \
+        uint16_t __c2; \
+        if((i)!=(length) && CBU16_IS_TRAIL(__c2=(s)[(i)])) { \
+            ++(i); \
+            (c)=CBU16_GET_SUPPLEMENTARY((c), __c2); \
+        } \
+    } \
+} CBUPRV_BLOCK_MACRO_END
 
 /**
  * Append a code point to a string, overwriting 1 or 2 code units.
  * The offset points to the current end of the string contents
  * and is advanced (post-increment).
- * "Unsafe" macro, assumes a valid code point and sufficient space in the
- * string. Otherwise, the result is undefined.
+ * "Unsafe" macro, assumes a valid code point and sufficient space in the string.
+ * Otherwise, the result is undefined.
  *
  * @param s const UChar * string buffer
  * @param i string offset
@@ -449,16 +479,89 @@ UChar32 utf8_nextCharSafeBody(const uint8_t* s,
  * @see U16_APPEND
  * @stable ICU 2.4
  */
-#define CBU16_APPEND_UNSAFE(s, i, c)                 \
-  {                                                  \
-    if ((uint32_t)(c) <= 0xffff) {                   \
-      (s)[(i)++] = (uint16_t)(c);                    \
-    } else {                                         \
-      (s)[(i)++] = (uint16_t)(((c) >> 10) + 0xd7c0); \
-      (s)[(i)++] = (uint16_t)(((c)&0x3ff) | 0xdc00); \
-    }                                                \
-  }
-
-}  // namespace base_icu
+#define CBU16_APPEND_UNSAFE(s, i, c) CBUPRV_BLOCK_MACRO_BEGIN { \
+    if((uint32_t)(c)<=0xffff) { \
+        (s)[(i)++]=(uint16_t)(c); \
+    } else { \
+        (s)[(i)++]=(uint16_t)(((c)>>10)+0xd7c0); \
+        (s)[(i)++]=(uint16_t)(((c)&0x3ff)|0xdc00); \
+    } \
+} CBUPRV_BLOCK_MACRO_END
+
+/**
+ * Adjust a random-access offset to a code point boundary
+ * at the start of a code point.
+ * If the offset points to the trail surrogate of a surrogate pair,
+ * then the offset is decremented.
+ * Otherwise, it is not modified.
+ * "Safe" macro, handles unpaired surrogates and checks for string boundaries.
+ *
+ * @param s const UChar * string
+ * @param start starting string offset (usually 0)
+ * @param i string offset, must be start<=i
+ * @see U16_SET_CP_START_UNSAFE
+ * @stable ICU 2.4
+ */
+#define CBU16_SET_CP_START(s, start, i) CBUPRV_BLOCK_MACRO_BEGIN { \
+    if(CBU16_IS_TRAIL((s)[i]) && (i)>(start) && CBU16_IS_LEAD((s)[(i)-1])) { \
+        --(i); \
+    } \
+} CBUPRV_BLOCK_MACRO_END
+
+/**
+ * Move the string offset from one code point boundary to the previous one
+ * and get the code point between them.
+ * (Pre-decrementing backward iteration.)
+ * "Safe" macro, handles unpaired surrogates and checks for string boundaries.
+ *
+ * The input offset may be the same as the string length.
+ * If the offset is behind a trail surrogate unit
+ * for a supplementary code point, then the macro will read
+ * the preceding lead surrogate as well.
+ * If the offset is behind a lead surrogate or behind a single, unpaired
+ * trail surrogate, then c is set to that unpaired surrogate.
+ *
+ * @param s const UChar * string
+ * @param start starting string offset (usually 0)
+ * @param i string offset, must be start<i
+ * @param c output UChar32 variable
+ * @see U16_PREV_UNSAFE
+ * @stable ICU 2.4
+ */
+#define CBU16_PREV(s, start, i, c) CBUPRV_BLOCK_MACRO_BEGIN { \
+    (c)=(s)[--(i)]; \
+    if(CBU16_IS_TRAIL(c)) { \
+        uint16_t __c2; \
+        if((i)>(start) && CBU16_IS_LEAD(__c2=(s)[(i)-1])) { \
+            --(i); \
+            (c)=CBU16_GET_SUPPLEMENTARY(__c2, (c)); \
+        } \
+    } \
+} CBUPRV_BLOCK_MACRO_END
+
+/**
+ * Adjust a random-access offset to a code point boundary after a code point.
+ * If the offset is behind the lead surrogate of a surrogate pair,
+ * then the offset is incremented.
+ * Otherwise, it is not modified.
+ * The input offset may be the same as the string length.
+ * "Safe" macro, handles unpaired surrogates and checks for string boundaries.
+ *
+ * The length can be negative for a NUL-terminated string.
+ *
+ * @param s const UChar * string
+ * @param start int32_t starting string offset (usually 0)
+ * @param i int32_t string offset, start<=i<=length
+ * @param length int32_t string length
+ * @see U16_SET_CP_LIMIT_UNSAFE
+ * @stable ICU 2.4
+ */
+#define CBU16_SET_CP_LIMIT(s, start, i, length) CBUPRV_BLOCK_MACRO_BEGIN { \
+    if((start)<(i) && ((i)<(length) || (length)<0) && CBU16_IS_LEAD((s)[(i)-1]) && CBU16_IS_TRAIL((s)[i])) { \
+        ++(i); \
+    } \
+} CBUPRV_BLOCK_MACRO_END
+
+}  // namesapce base_icu
 
 #endif  // BASE_THIRD_PARTY_ICU_ICU_UTF_H_
diff --git a/gn/src/gn/action_target_generator.cc b/gn/src/gn/action_target_generator.cc
index 73fa28895a7..513015bae64 100644
--- a/gn/src/gn/action_target_generator.cc
+++ b/gn/src/gn/action_target_generator.cc
@@ -6,6 +6,7 @@
 
 #include "base/stl_util.h"
 #include "gn/build_settings.h"
+#include "gn/config_values_generator.h"
 #include "gn/err.h"
 #include "gn/filesystem_utils.h"
 #include "gn/functions.h"
@@ -63,9 +64,19 @@ void ActionTargetGenerator::DoRun() {
   if (!FillCheckIncludes())
     return;
 
+  if (!FillConfigs())
+    return;
+
   if (!CheckOutputs())
     return;
 
+  // Config values (compiler flags, etc.) set directly on this target.
+  ConfigValuesGenerator gen(&target_->config_values(), scope_,
+                            scope_->GetSourceDir(), err_);
+  gen.Run();
+  if (err_->has_error())
+    return;
+
   // Action outputs don't depend on the current toolchain so we can skip adding
   // that dependency.
 
@@ -172,7 +183,7 @@ bool ActionTargetGenerator::FillPool() {
   LabelPtrPair<Pool> pair(label);
   pair.origin = target_->defined_from();
 
-  target_->action_values().set_pool(std::move(pair));
+  target_->set_pool(std::move(pair));
   return true;
 }
 
diff --git a/gn/src/gn/action_values.h b/gn/src/gn/action_values.h
index 30436b7a6fe..9daf9182c0a 100644
--- a/gn/src/gn/action_values.h
+++ b/gn/src/gn/action_values.h
@@ -51,17 +51,12 @@ class ActionValues {
   }
   bool uses_rsp_file() const { return !rsp_file_contents_.list().empty(); }
 
-  // Pool option
-  const LabelPtrPair<Pool>& pool() const { return pool_; }
-  void set_pool(LabelPtrPair<Pool> pool) { pool_ = std::move(pool); }
-
  private:
   SourceFile script_;
   SubstitutionList args_;
   SubstitutionList outputs_;
   SubstitutionPattern depfile_;
   SubstitutionList rsp_file_contents_;
-  LabelPtrPair<Pool> pool_;
 
   ActionValues(const ActionValues&) = delete;
   ActionValues& operator=(const ActionValues&) = delete;
diff --git a/gn/src/gn/analyzer.cc b/gn/src/gn/analyzer.cc
index fd93879ec88..be646ee8512 100644
--- a/gn/src/gn/analyzer.cc
+++ b/gn/src/gn/analyzer.cc
@@ -89,7 +89,7 @@ void WriteString(base::DictionaryValue& dict,
                  const std::string& key,
                  const std::string& value) {
   dict.SetKey(key, base::Value(value));
-};
+}
 
 void WriteLabels(const Label& default_toolchain,
                  base::DictionaryValue& dict,
@@ -183,7 +183,7 @@ Err JSONToInputs(const Label& default_toolchain,
     }
   }
 
-  for (const auto& kv : dict->DictItems()) {
+  for (const auto kv : dict->DictItems()) {
     if (kv.first == kFilesKey || kv.first == kAdditonalCompileTargetsKey ||
         kv.first == kTestTargetsKey) {
       continue;
@@ -254,10 +254,11 @@ Analyzer::Analyzer(const Builder& builder,
 
       dep_map_.insert(std::make_pair(item->AsTarget()->toolchain(), item));
 
-      if (item->AsTarget()->output_type() == Target::ACTION ||
+      if (item->AsTarget()->IsBinary() ||
+          item->AsTarget()->output_type() == Target::ACTION ||
           item->AsTarget()->output_type() == Target::ACTION_FOREACH) {
         const LabelPtrPair<Pool>& pool =
-            item->AsTarget()->action_values().pool();
+            item->AsTarget()->pool();
         if (pool.ptr)
           dep_map_.insert(std::make_pair(pool.ptr, item));
       }
diff --git a/gn/src/gn/analyzer_unittest.cc b/gn/src/gn/analyzer_unittest.cc
index 98bef673bcb..e3d5696e377 100644
--- a/gn/src/gn/analyzer_unittest.cc
+++ b/gn/src/gn/analyzer_unittest.cc
@@ -480,7 +480,7 @@ TEST_F(AnalyzerTest, AffectedPoolpropagatesToDependentTargets) {
   t->set_output_type(Target::ACTION);
   std::unique_ptr<Pool> p = MakePool("//dir", "pool_name");
   Pool* p_raw = p.get();
-  t->action_values().set_pool(LabelPtrPair<Pool>(p.get()));
+  t->set_pool(LabelPtrPair<Pool>(p.get()));
 
   builder_.ItemDefined(std::move(t));
   builder_.ItemDefined(std::move(p));
diff --git a/gn/src/gn/args.cc b/gn/src/gn/args.cc
index 133eff1d05c..fbc0ee4a44b 100644
--- a/gn/src/gn/args.cc
+++ b/gn/src/gn/args.cc
@@ -269,7 +269,8 @@ Args::ValueWithOverrideMap Args::GetAllArguments() const {
   std::lock_guard<std::mutex> lock(lock_);
 
   // Sort the keys from declared_arguments_per_toolchain_ so
-  // the return value will be deterministic.
+  // the return value will be deterministic. Always prioritize
+  // the default toolchain.
   std::vector<const Settings*> keys;
   keys.reserve(declared_arguments_per_toolchain_.size());
   for (const auto& map_pair : declared_arguments_per_toolchain_) {
@@ -277,7 +278,8 @@ Args::ValueWithOverrideMap Args::GetAllArguments() const {
   }
   std::sort(keys.begin(), keys.end(),
             [](const Settings* a, const Settings* b) -> bool {
-              return a->toolchain_label() < b->toolchain_label();
+              return a->is_default() ||
+                     a->toolchain_label() < b->toolchain_label();
             });
 
   // Default values.
diff --git a/gn/src/gn/binary_target_generator.cc b/gn/src/gn/binary_target_generator.cc
index 4cac96f97ad..07df7bff647 100644
--- a/gn/src/gn/binary_target_generator.cc
+++ b/gn/src/gn/binary_target_generator.cc
@@ -64,6 +64,9 @@ void BinaryTargetGenerator::DoRun() {
   if (!FillCompleteStaticLib())
     return;
 
+  if (!FillPool())
+    return;
+
   if (!ValidateSources())
     return;
 
@@ -215,8 +218,12 @@ bool BinaryTargetGenerator::FillAllowCircularIncludesFrom() {
       }
     }
     if (!found_dep) {
+      bool with_toolchain = scope_->settings()->ShouldShowToolchain({
+        &target_->label(),
+        &cur
+      });
       *err_ = Err(*value, "Label not in deps.",
-                  "The label \"" + cur.GetUserVisibleName(false) +
+                  "The label \"" + cur.GetUserVisibleName(with_toolchain) +
                       "\"\nwas not in the deps of this target. "
                       "allow_circular_includes_from only allows\ntargets "
                       "present in the "
@@ -231,6 +238,25 @@ bool BinaryTargetGenerator::FillAllowCircularIncludesFrom() {
   return true;
 }
 
+bool BinaryTargetGenerator::FillPool() {
+  const Value* value = scope_->GetValue(variables::kPool, true);
+  if (!value)
+    return true;
+
+  Label label =
+      Label::Resolve(scope_->GetSourceDir(),
+                     scope_->settings()->build_settings()->root_path_utf8(),
+                     ToolchainLabelForScope(scope_), *value, err_);
+  if (err_->has_error())
+    return false;
+
+  LabelPtrPair<Pool> pair(label);
+  pair.origin = target_->defined_from();
+
+  target_->set_pool(std::move(pair));
+  return true;
+}
+
 bool BinaryTargetGenerator::ValidateSources() {
   // For Rust targets, if the only source file is the root `sources` can be
   // omitted/empty.
diff --git a/gn/src/gn/binary_target_generator.h b/gn/src/gn/binary_target_generator.h
index 2c8b7695bb8..0bafd683c34 100644
--- a/gn/src/gn/binary_target_generator.h
+++ b/gn/src/gn/binary_target_generator.h
@@ -30,6 +30,7 @@ class BinaryTargetGenerator : public TargetGenerator {
   bool FillOutputPrefixOverride();
   bool FillOutputDir();
   bool FillAllowCircularIncludesFrom();
+  bool FillPool();
   bool ValidateSources();
 
   Target::OutputType output_type_;
diff --git a/gn/src/gn/build_settings.h b/gn/src/gn/build_settings.h
index 9a6c5147aa9..6c925e985e0 100644
--- a/gn/src/gn/build_settings.h
+++ b/gn/src/gn/build_settings.h
@@ -61,6 +61,15 @@ class BuildSettings {
   }
   void set_ninja_required_version(Version v) { ninja_required_version_ = v; }
 
+  // The 'no_stamp_files' boolean flag can be set to generate Ninja files
+  // that use phony rules instead of stamp files in most cases. This reduces
+  // the size of the generated Ninja build plans, but requires Ninja 1.11
+  // or greater to properly process them.
+  bool no_stamp_files() const { return no_stamp_files_; }
+  void set_no_stamp_files(bool no_stamp_files) {
+    no_stamp_files_ = no_stamp_files;
+  }
+
   const SourceFile& build_config_file() const { return build_config_file_; }
   void set_build_config_file(const SourceFile& f) { build_config_file_ = f; }
 
@@ -134,6 +143,7 @@ class BuildSettings {
 
   // See 40045b9 for the reason behind using 1.7.2 as the default version.
   Version ninja_required_version_{1, 7, 2};
+  bool no_stamp_files_ = false;
 
   SourceFile build_config_file_;
   SourceFile arg_file_template_path_;
diff --git a/gn/src/gn/builder.cc b/gn/src/gn/builder.cc
index adb39ab1a8f..81335f86ff2 100644
--- a/gn/src/gn/builder.cc
+++ b/gn/src/gn/builder.cc
@@ -75,8 +75,9 @@ void Builder::ItemDefined(std::unique_ptr<Item> item) {
 
   // Check that it's not been already defined.
   if (record->item()) {
+    bool with_toolchain = item->settings()->ShouldShowToolchain({&item->label()});
     err = Err(item->defined_from(), "Duplicate definition.",
-              "The item\n  " + item->label().GetUserVisibleName(false) +
+              "The item\n  " + item->label().GetUserVisibleName(with_toolchain) +
                   "\nwas already defined.");
     err.AppendSubErr(
         Err(record->item()->defined_from(), "Previous definition:"));
@@ -232,7 +233,7 @@ bool Builder::CheckForBadItems(Err* err) const {
           "possibly due to an\ninternal error:";
       for (auto* bad_record : bad_records) {
         depstring +=
-            "\n\"" + bad_record->label().GetUserVisibleName(false) + "\"";
+            "\n\"" + bad_record->label().GetUserVisibleName(true) + "\"";
       }
       *err = Err(Location(), "", depstring);
     } else {
@@ -254,7 +255,7 @@ bool Builder::TargetDefined(BuilderRecord* record, Err* err) {
       !AddDeps(record, target->all_dependent_configs(), err) ||
       !AddDeps(record, target->public_configs(), err) ||
       !AddGenDeps(record, target->gen_deps(), err) ||
-      !AddActionValuesDep(record, target->action_values(), err) ||
+      !AddPoolDep(record, target, err) ||
       !AddToolchainDep(record, target, err))
     return false;
 
@@ -330,7 +331,7 @@ BuilderRecord* Builder::GetOrCreateRecordOfType(const Label& label,
   // Check types, if the record was not just created.
   if (!pair.first && record->type() != type) {
     std::string msg =
-        "The type of " + label.GetUserVisibleName(false) + "\nhere is a " +
+        "The type of " + label.GetUserVisibleName(true) + "\nhere is a " +
         BuilderRecord::GetNameForType(type) + " but was previously seen as a " +
         BuilderRecord::GetNameForType(record->type()) +
         ".\n\n"
@@ -354,7 +355,7 @@ BuilderRecord* Builder::GetResolvedRecordOfType(const Label& label,
   BuilderRecord* record = GetRecord(label);
   if (!record) {
     *err = Err(origin, "Item not found",
-               "\"" + label.GetUserVisibleName(false) +
+               "\"" + label.GetUserVisibleName(true) +
                    "\" doesn't\n"
                    "refer to an existent thing.");
     return nullptr;
@@ -364,7 +365,7 @@ BuilderRecord* Builder::GetResolvedRecordOfType(const Label& label,
   if (!item) {
     *err = Err(
         origin, "Item not resolved.",
-        "\"" + label.GetUserVisibleName(false) + "\" hasn't been resolved.\n");
+        "\"" + label.GetUserVisibleName(true) + "\" hasn't been resolved.\n");
     return nullptr;
   }
 
@@ -372,7 +373,7 @@ BuilderRecord* Builder::GetResolvedRecordOfType(const Label& label,
     *err =
         Err(origin,
             std::string("This is not a ") + BuilderRecord::GetNameForType(type),
-            "\"" + label.GetUserVisibleName(false) + "\" refers to a " +
+            "\"" + label.GetUserVisibleName(true) + "\" refers to a " +
                 item->GetItemTypeName() + " instead of a " +
                 BuilderRecord::GetNameForType(type) + ".");
     return nullptr;
@@ -432,14 +433,14 @@ bool Builder::AddGenDeps(BuilderRecord* record,
   return true;
 }
 
-bool Builder::AddActionValuesDep(BuilderRecord* record,
-                                 const ActionValues& action_values,
-                                 Err* err) {
-  if (action_values.pool().label.is_null())
+bool Builder::AddPoolDep(BuilderRecord* record,
+                         const Target* target,
+                         Err* err) {
+  if (target->pool().label.is_null())
     return true;
 
   BuilderRecord* pool_record = GetOrCreateRecordOfType(
-      action_values.pool().label, action_values.pool().origin,
+      target->pool().label, target->pool().origin,
       BuilderRecord::ITEM_POOL, err);
   if (!pool_record)
     return false;
@@ -500,7 +501,7 @@ bool Builder::ResolveItem(BuilderRecord* record, Err* err) {
         !ResolveConfigs(&target->configs(), err) ||
         !ResolveConfigs(&target->all_dependent_configs(), err) ||
         !ResolveConfigs(&target->public_configs(), err) ||
-        !ResolveActionValues(&target->action_values(), err) ||
+        !ResolvePool(target, err) ||
         !ResolveToolchain(target, err))
       return false;
   } else if (record->type() == BuilderRecord::ITEM_CONFIG) {
@@ -579,16 +580,16 @@ bool Builder::ResolveToolchain(Target* target, Err* err) {
   return true;
 }
 
-bool Builder::ResolveActionValues(ActionValues* action_values, Err* err) {
-  if (action_values->pool().label.is_null())
+bool Builder::ResolvePool(Target* target, Err* err) {
+  if (target->pool().label.is_null())
     return true;
 
   BuilderRecord* record = GetResolvedRecordOfType(
-      action_values->pool().label, action_values->pool().origin,
+      target->pool().label, target->pool().origin,
       BuilderRecord::ITEM_POOL, err);
   if (!record)
     return false;
-  action_values->set_pool(LabelPtrPair<Pool>(record->item()->AsPool()));
+  target->set_pool(LabelPtrPair<Pool>(record->item()->AsPool()));
 
   return true;
 }
diff --git a/gn/src/gn/builder.h b/gn/src/gn/builder.h
index bebaa8143b8..e89e2e1a2c6 100644
--- a/gn/src/gn/builder.h
+++ b/gn/src/gn/builder.h
@@ -101,9 +101,9 @@ class Builder {
   bool AddGenDeps(BuilderRecord* record,
                   const LabelTargetVector& targets,
                   Err* err);
-  bool AddActionValuesDep(BuilderRecord* record,
-                          const ActionValues& action_values,
-                          Err* err);
+  bool AddPoolDep(BuilderRecord* record,
+                  const Target* target,
+                  Err* err);
   bool AddToolchainDep(BuilderRecord* record, const Target* target, Err* err);
 
   // Given a target, sets the "should generate" bit and pushes it through the
@@ -129,7 +129,7 @@ class Builder {
   // if anything isn't found or if the type doesn't match.
   bool ResolveDeps(LabelTargetVector* deps, Err* err);
   bool ResolveConfigs(UniqueVector<LabelConfigPair>* configs, Err* err);
-  bool ResolveActionValues(ActionValues* action_values, Err* err);
+  bool ResolvePool(Target* target, Err* err);
   bool ResolveToolchain(Target* target, Err* err);
   bool ResolvePools(Toolchain* toolchain, Err* err);
 
diff --git a/gn/src/gn/builtin_tool.cc b/gn/src/gn/builtin_tool.cc
new file mode 100644
index 00000000000..e9f17ef116f
--- /dev/null
+++ b/gn/src/gn/builtin_tool.cc
@@ -0,0 +1,47 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "gn/builtin_tool.h"
+#include "base/logging.h"
+#include "gn/target.h"
+
+// static
+const char BuiltinTool::kBuiltinToolPhony[] = "phony";
+
+BuiltinTool::BuiltinTool(const char* n) : Tool(n) {
+  CHECK(ValidateName(n));
+  // Unlike regular tools, which are read from a file,
+  // builtin-tools are always ready to go and do not need
+  // phased construction.
+  SetToolComplete();
+}
+
+BuiltinTool::~BuiltinTool() = default;
+
+BuiltinTool* BuiltinTool::AsBuiltin() {
+  return this;
+}
+const BuiltinTool* BuiltinTool::AsBuiltin() const {
+  return this;
+}
+
+bool BuiltinTool::ValidateName(const char* name) const {
+  return name == kBuiltinToolPhony;
+}
+
+void BuiltinTool::SetComplete() {
+  // Already performed in constructor
+}
+
+bool BuiltinTool::InitTool(Scope* scope, Toolchain* toolchain, Err* err) {
+  // Initialize default vars.
+  return Tool::InitTool(scope, toolchain, err);
+}
+
+bool BuiltinTool::ValidateSubstitution(const Substitution* sub_type) const {
+  if (name_ == kBuiltinToolPhony)
+    return IsValidToolSubstitution(sub_type);
+  NOTREACHED();
+  return false;
+}
diff --git a/gn/src/gn/builtin_tool.h b/gn/src/gn/builtin_tool.h
new file mode 100644
index 00000000000..0aff49d071b
--- /dev/null
+++ b/gn/src/gn/builtin_tool.h
@@ -0,0 +1,41 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef TOOLS_GN_BUILTIN_TOOL_H_
+#define TOOLS_GN_BUILTIN_TOOL_H_
+
+#include <string>
+
+#include "gn/substitution_list.h"
+#include "gn/substitution_pattern.h"
+#include "gn/tool.h"
+
+// A built-in tool that is always available regardless of toolchain. So far, the
+// only example of this is the phony rule that ninja provides.
+class BuiltinTool : public Tool {
+ public:
+  // Builtin tools
+  static const char kBuiltinToolPhony[];
+
+  // Explicit constructor. Note that |name| must be one of the kBuiltinToolXXX
+  // constant pointers defined above.
+  explicit BuiltinTool(const char* name);
+  ~BuiltinTool();
+
+  // Manual RTTI and required functions ---------------------------------------
+
+  bool InitTool(Scope* block_scope, Toolchain* toolchain, Err* err);
+  bool ValidateName(const char* name) const override;
+  void SetComplete() override;
+  bool ValidateSubstitution(const Substitution* sub_type) const override;
+
+  BuiltinTool* AsBuiltin() override;
+  const BuiltinTool* AsBuiltin() const override;
+
+ private:
+  BuiltinTool(const BuiltinTool&) = delete;
+  BuiltinTool& operator=(const BuiltinTool&) = delete;
+};
+
+#endif  // TOOLS_GN_BUILTIN_TOOL_H_
diff --git a/gn/src/gn/bundle_data.h b/gn/src/gn/bundle_data.h
index 527e0786733..5b3bca6a742 100644
--- a/gn/src/gn/bundle_data.h
+++ b/gn/src/gn/bundle_data.h
@@ -162,6 +162,11 @@ class BundleData {
   // Recursive collection of all bundle_data that the target depends on.
   const UniqueTargets& bundle_deps() const { return bundle_deps_; }
 
+  // Returns whether the bundle is an application bundle.
+  bool is_application() const {
+    return product_type_ == "com.apple.product-type.application";
+  }
+
   // Returns whether the bundle is a framework bundle.
   bool is_framework() const {
     return product_type_ == "com.apple.product-type.framework";
diff --git a/gn/src/gn/c_substitution_type.cc b/gn/src/gn/c_substitution_type.cc
index ea47ce9da9c..971d87a46ff 100644
--- a/gn/src/gn/c_substitution_type.cc
+++ b/gn/src/gn/c_substitution_type.cc
@@ -92,6 +92,19 @@ bool IsValidCompilerSubstitution(const Substitution* type) {
          type == &CSubstitutionModuleDepsNoSelf;
 }
 
+bool IsValidCompilerScriptArgsSubstitution(const Substitution* type) {
+  return type == &CSubstitutionAsmFlags || type == &CSubstitutionCFlags ||
+         type == &CSubstitutionCFlagsC || type == &CSubstitutionCFlagsCc ||
+         type == &CSubstitutionCFlagsObjC ||
+         type == &CSubstitutionCFlagsObjCc || type == &CSubstitutionDefines ||
+         type == &CSubstitutionFrameworkDirs ||
+         type == &CSubstitutionIncludeDirs ||
+         type == &CSubstitutionSwiftModuleName ||
+         type == &CSubstitutionSwiftBridgeHeader ||
+         type == &CSubstitutionSwiftModuleDirs ||
+         type == &CSubstitutionSwiftFlags;
+}
+
 bool IsValidCompilerOutputsSubstitution(const Substitution* type) {
   // All tool types except "output" (which would be infinitely recursive).
   return (IsValidToolSubstitution(type) && type != &SubstitutionOutput) ||
diff --git a/gn/src/gn/c_substitution_type.h b/gn/src/gn/c_substitution_type.h
index 1f4e90e06a3..d0d1f8c4167 100644
--- a/gn/src/gn/c_substitution_type.h
+++ b/gn/src/gn/c_substitution_type.h
@@ -54,4 +54,7 @@ bool IsValidLinkerSubstitution(const Substitution* type);
 bool IsValidLinkerOutputsSubstitution(const Substitution* type);
 bool IsValidALinkSubstitution(const Substitution* type);
 
+// action targets may rely on some compiler substitutions.
+bool IsValidCompilerScriptArgsSubstitution(const Substitution* type);
+
 #endif  // TOOLS_GN_C_SUBSTITUTION_TYPE_H_
diff --git a/gn/src/gn/command_args.cc b/gn/src/gn/command_args.cc
index e74c59862ee..6f4600bdd99 100644
--- a/gn/src/gn/command_args.cc
+++ b/gn/src/gn/command_args.cc
@@ -212,7 +212,7 @@ int ListArgs(const std::string& build_dir) {
   Args::ValueWithOverrideMap args =
       setup->build_settings().build_args().GetAllArguments();
   std::string list_value =
-      base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(kSwitchList);
+      base::CommandLine::ForCurrentProcess()->GetSwitchValueString(kSwitchList);
   if (!list_value.empty()) {
     // List just the one specified as the parameter to --list.
     auto found = args.find(list_value);
diff --git a/gn/src/gn/command_clean.cc b/gn/src/gn/command_clean.cc
index 5290dd65253..6dcc1631496 100644
--- a/gn/src/gn/command_clean.cc
+++ b/gn/src/gn/command_clean.cc
@@ -5,45 +5,16 @@
 #include "base/files/file_enumerator.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
-#include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "gn/commands.h"
 #include "gn/err.h"
 #include "gn/filesystem_utils.h"
+#include "gn/ninja_build_writer.h"
 #include "gn/setup.h"
 
 namespace {
 
-// Extracts from a build.ninja the commands to run GN.
-//
-// The commands to run GN are the gn rule and build.ninja build step at the top
-// of the build.ninja file. We want to keep these when deleting GN builds since
-// we want to preserve the command-line flags to GN.
-//
-// On error, returns the empty string.
-std::string ExtractGNBuildCommands(const base::FilePath& build_ninja_file) {
-  std::string file_contents;
-  if (!base::ReadFileToString(build_ninja_file, &file_contents))
-    return std::string();
-
-  std::vector<std::string_view> lines = base::SplitStringPiece(
-      file_contents, "\n", base::KEEP_WHITESPACE, base::SPLIT_WANT_ALL);
-
-  std::string result;
-  int num_blank_lines = 0;
-  for (const auto& line : lines) {
-    result.append(line);
-    result.push_back('\n');
-    if (line.empty())
-      ++num_blank_lines;
-    if (num_blank_lines == 3)
-      break;
-  }
-
-  return result;
-}
-
 bool CleanOneDir(const std::string& dir) {
   // Deliberately leaked to avoid expensive process teardown.
   Setup* setup = new Setup;
@@ -53,10 +24,12 @@ bool CleanOneDir(const std::string& dir) {
   base::FilePath build_dir(setup->build_settings().GetFullPath(
       SourceDir(setup->build_settings().build_dir().value())));
 
-  // NOTE: Not all GN builds have args.gn file hence we check here
+  // NOTE: Not all GN builds have args.gn file hence we also check here
   // if a build.ninja.d files exists instead.
+  base::FilePath args_gn_file = build_dir.AppendASCII("args.gn");
   base::FilePath build_ninja_d_file = build_dir.AppendASCII("build.ninja.d");
-  if (!base::PathExists(build_ninja_d_file)) {
+  if (!base::PathExists(args_gn_file) &&
+      !base::PathExists(build_ninja_d_file)) {
     Err(Location(),
         base::StringPrintf(
             "%s does not look like a build directory.\n",
@@ -65,47 +38,32 @@ bool CleanOneDir(const std::string& dir) {
     return false;
   }
 
-  // Erase everything but the args file, and write a dummy build.ninja file that
-  // will automatically rerun GN the next time Ninja is run.
-  base::FilePath build_ninja_file = build_dir.AppendASCII("build.ninja");
-  std::string build_commands = ExtractGNBuildCommands(build_ninja_file);
-  if (build_commands.empty()) {
-    // Couldn't parse the build.ninja file.
-    Err(Location(), "Couldn't read build.ninja in this directory.",
-        "Try running \"gn gen\" on it and then re-running \"gn clean\".")
-        .PrintToStdout();
+  // Replace existing build.ninja with just enough for ninja to call GN and
+  // regenerate ninja files.
+  if (!commands::PrepareForRegeneration(&setup->build_settings())) {
     return false;
   }
 
+  // Erase everything but (user-created) args.gn and the build.ninja files we
+  // just wrote.
+  const base::FilePath::CharType* remaining[]{
+      FILE_PATH_LITERAL("args.gn"),
+      FILE_PATH_LITERAL("build.ninja"),
+      FILE_PATH_LITERAL("build.ninja.d"),
+  };
   base::FileEnumerator traversal(
       build_dir, false,
       base::FileEnumerator::FILES | base::FileEnumerator::DIRECTORIES);
   for (base::FilePath current = traversal.Next(); !current.empty();
        current = traversal.Next()) {
-    if (base::ToLowerASCII(current.BaseName().value()) !=
-        FILE_PATH_LITERAL("args.gn")) {
+    base::FilePath::StringType basename =
+        base::ToLowerASCII(current.BaseName().value());
+    if (std::none_of(std::begin(remaining), std::end(remaining),
+                     [&](auto rem) { return basename == rem; })) {
       base::DeleteFile(current, true);
     }
   }
 
-  // Write the build.ninja file sufficiently to regenerate itself.
-  if (base::WriteFile(build_ninja_file, build_commands.data(),
-                      static_cast<int>(build_commands.size())) == -1) {
-    Err(Location(), std::string("Failed to write build.ninja."))
-        .PrintToStdout();
-    return false;
-  }
-
-  // Write a .d file for the build which references a nonexistent file.
-  // This will make Ninja always mark the build as dirty.
-  std::string dummy_content("build.ninja: nonexistant_file.gn\n");
-  if (base::WriteFile(build_ninja_d_file, dummy_content.data(),
-                      static_cast<int>(dummy_content.size())) == -1) {
-    Err(Location(), std::string("Failed to write build.ninja.d."))
-        .PrintToStdout();
-    return false;
-  }
-
   return true;
 }
 
diff --git a/gn/src/gn/command_desc.cc b/gn/src/gn/command_desc.cc
index fcb343442fb..e3cd1eb0716 100644
--- a/gn/src/gn/command_desc.cc
+++ b/gn/src/gn/command_desc.cc
@@ -653,7 +653,7 @@ int RunDesc(const std::vector<std::string>& args) {
   if (args.size() == 3)
     what_to_print = args[2];
 
-  bool json = cmdline->GetSwitchValueASCII("format") == "json";
+  bool json = cmdline->GetSwitchValueString("format") == "json";
 
   if (target_matches.empty() && config_matches.empty()) {
     OutputString(
diff --git a/gn/src/gn/command_format.cc b/gn/src/gn/command_format.cc
index a3fda2120be..69077104386 100644
--- a/gn/src/gn/command_format.cc
+++ b/gn/src/gn/command_format.cc
@@ -170,6 +170,10 @@ class Printer {
   // 'visibility': same as 'deps'.
   void SortIfApplicable(const BinaryOpNode* binop);
 
+  // Traverse a binary op node tree and apply a callback to each leaf node.
+  void TraverseBinaryOpNode(const ParseNode* node,
+                            std::function<void(const ParseNode*)> callback);
+
   // Sort contiguous import() function calls in the given ordered list of
   // statements (the body of a block or scope).
   template <class PARSENODE>
@@ -403,17 +407,37 @@ void Printer::SortIfApplicable(const BinaryOpNode* binop) {
     }
   }
   const IdentifierNode* ident = binop->left()->AsIdentifier();
-  const ListNode* list = binop->right()->AsList();
   if ((binop->op().value() == "=" || binop->op().value() == "+=" ||
        binop->op().value() == "-=") &&
-      ident && list) {
+      ident) {
     const std::string_view lhs = ident->value().value();
     if (base::EndsWith(lhs, "sources", base::CompareCase::SENSITIVE) ||
-        lhs == "public")
-      const_cast<ListNode*>(list)->SortAsStringsList();
-    else if (base::EndsWith(lhs, "deps", base::CompareCase::SENSITIVE) ||
-             lhs == "visibility")
-      const_cast<ListNode*>(list)->SortAsTargetsList();
+        lhs == "public") {
+      TraverseBinaryOpNode(binop->right(), [](const ParseNode* node) {
+        const ListNode* list = node->AsList();
+        if (list)
+          const_cast<ListNode*>(list)->SortAsStringsList();
+      });
+    } else if (base::EndsWith(lhs, "deps", base::CompareCase::SENSITIVE) ||
+               lhs == "visibility") {
+      TraverseBinaryOpNode(binop->right(), [](const ParseNode* node) {
+        const ListNode* list = node->AsList();
+        if (list)
+          const_cast<ListNode*>(list)->SortAsTargetsList();
+      });
+    }
+  }
+}
+
+void Printer::TraverseBinaryOpNode(
+    const ParseNode* node,
+    std::function<void(const ParseNode*)> callback) {
+  const BinaryOpNode* binop = node->AsBinaryOp();
+  if (binop) {
+    TraverseBinaryOpNode(binop->left(), callback);
+    TraverseBinaryOpNode(binop->right(), callback);
+  } else {
+    callback(node);
   }
 }
 
@@ -519,7 +543,7 @@ int SuffixCommentTreeWalk(const ParseNode* node) {
 
 #define RETURN_IF_SET(x)             \
   if (int result = (x); result >= 0) \
-    return result;
+    return result
 
   if (const AccessorNode* accessor = node->AsAccessor()) {
     RETURN_IF_SET(SuffixCommentTreeWalk(accessor->subscript()));
@@ -559,7 +583,7 @@ int SuffixCommentTreeWalk(const ParseNode* node) {
   }
 
   return -1;
-};
+}
 
 // If there are suffix comments on the first node or its children, they might
 // carry down multiple lines. Otherwise, use the node's normal end range. This
@@ -1282,7 +1306,7 @@ int RunFormat(const std::vector<std::string>& args) {
   TreeDumpMode dump_tree = TreeDumpMode::kInactive;
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(kSwitchDumpTree)) {
     std::string tree_type =
-        base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+        base::CommandLine::ForCurrentProcess()->GetSwitchValueString(
             kSwitchDumpTree);
     if (tree_type == kSwitchTreeTypeJSON) {
       dump_tree = TreeDumpMode::kJSON;
@@ -1337,7 +1361,7 @@ int RunFormat(const std::vector<std::string>& args) {
 
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(kSwitchReadTree)) {
     std::string tree_type =
-        base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+        base::CommandLine::ForCurrentProcess()->GetSwitchValueString(
             kSwitchReadTree);
     if (tree_type != kSwitchTreeTypeJSON) {
       Err(Location(), "Only json supported for read-tree.\n").PrintToStdout();
diff --git a/gn/src/gn/command_format_unittest.cc b/gn/src/gn/command_format_unittest.cc
index 9112dd36229..de7e004182f 100644
--- a/gn/src/gn/command_format_unittest.cc
+++ b/gn/src/gn/command_format_unittest.cc
@@ -136,3 +136,4 @@ FORMAT_TEST(080)
 FORMAT_TEST(081)
 FORMAT_TEST(082)
 FORMAT_TEST(083)
+FORMAT_TEST(084)
diff --git a/gn/src/gn/command_gen.cc b/gn/src/gn/command_gen.cc
index 23f15a099f5..880fb20759a 100644
--- a/gn/src/gn/command_gen.cc
+++ b/gn/src/gn/command_gen.cc
@@ -14,6 +14,7 @@
 #include "gn/eclipse_writer.h"
 #include "gn/filesystem_utils.h"
 #include "gn/json_project_writer.h"
+#include "gn/label_pattern.h"
 #include "gn/ninja_target_writer.h"
 #include "gn/ninja_tools.h"
 #include "gn/ninja_writer.h"
@@ -56,6 +57,11 @@ const char kSwitchXcodeProject[] = "xcode-project";
 const char kSwitchXcodeBuildSystem[] = "xcode-build-system";
 const char kSwitchXcodeBuildsystemValueLegacy[] = "legacy";
 const char kSwitchXcodeBuildsystemValueNew[] = "new";
+const char kSwitchXcodeConfigurations[] = "xcode-configs";
+const char kSwitchXcodeConfigurationBuildPath[] = "xcode-config-build-dir";
+const char kSwitchXcodeAdditionalFilesPatterns[] =
+    "xcode-additional-files-patterns";
+const char kSwitchXcodeAdditionalFilesRoots[] = "xcode-additional-files-roots";
 const char kSwitchJsonFileName[] = "json-file-name";
 const char kSwitchJsonIdeScript[] = "json-ide-script";
 const char kSwitchJsonIdeScriptArgs[] = "json-ide-script-args";
@@ -224,22 +230,22 @@ bool RunIdeWriter(const std::string& ide,
 
     std::string sln_name;
     if (command_line->HasSwitch(kSwitchSln))
-      sln_name = command_line->GetSwitchValueASCII(kSwitchSln);
+      sln_name = command_line->GetSwitchValueString(kSwitchSln);
     std::string filters;
     if (command_line->HasSwitch(kSwitchFilters))
-      filters = command_line->GetSwitchValueASCII(kSwitchFilters);
+      filters = command_line->GetSwitchValueString(kSwitchFilters);
     std::string win_kit;
     if (command_line->HasSwitch(kSwitchIdeValueWinSdk))
-      win_kit = command_line->GetSwitchValueASCII(kSwitchIdeValueWinSdk);
+      win_kit = command_line->GetSwitchValueString(kSwitchIdeValueWinSdk);
     std::string ninja_extra_args;
     if (command_line->HasSwitch(kSwitchNinjaExtraArgs)) {
       ninja_extra_args =
-          command_line->GetSwitchValueASCII(kSwitchNinjaExtraArgs);
+          command_line->GetSwitchValueString(kSwitchNinjaExtraArgs);
     }
     std::string ninja_executable;
     if (command_line->HasSwitch(kSwitchNinjaExecutable)) {
       ninja_executable =
-          command_line->GetSwitchValueASCII(kSwitchNinjaExecutable);
+          command_line->GetSwitchValueString(kSwitchNinjaExecutable);
     }
     bool no_deps = command_line->HasSwitch(kSwitchNoDeps);
     bool res = VisualStudioWriter::RunAndWriteFiles(
@@ -253,10 +259,14 @@ bool RunIdeWriter(const std::string& ide,
     return res;
   } else if (ide == kSwitchIdeValueXcode) {
     XcodeWriter::Options options = {
-        command_line->GetSwitchValueASCII(kSwitchXcodeProject),
-        command_line->GetSwitchValueASCII(kSwitchIdeRootTarget),
-        command_line->GetSwitchValueASCII(kSwitchNinjaExecutable),
-        command_line->GetSwitchValueASCII(kSwitchFilters),
+        command_line->GetSwitchValueString(kSwitchXcodeProject),
+        command_line->GetSwitchValueString(kSwitchIdeRootTarget),
+        command_line->GetSwitchValueString(kSwitchNinjaExecutable),
+        command_line->GetSwitchValueString(kSwitchFilters),
+        command_line->GetSwitchValueString(kSwitchXcodeConfigurations),
+        command_line->GetSwitchValuePath(kSwitchXcodeConfigurationBuildPath),
+        command_line->GetSwitchValueNative(kSwitchXcodeAdditionalFilesPatterns),
+        command_line->GetSwitchValueNative(kSwitchXcodeAdditionalFilesRoots),
         XcodeBuildSystem::kLegacy,
     };
 
@@ -265,7 +275,7 @@ bool RunIdeWriter(const std::string& ide,
     }
 
     const std::string build_system =
-        command_line->GetSwitchValueASCII(kSwitchXcodeBuildSystem);
+        command_line->GetSwitchValueString(kSwitchXcodeBuildSystem);
     if (!build_system.empty()) {
       if (build_system == kSwitchXcodeBuildsystemValueNew) {
         options.build_system = XcodeBuildSystem::kNew;
@@ -288,7 +298,7 @@ bool RunIdeWriter(const std::string& ide,
   } else if (ide == kSwitchIdeValueQtCreator) {
     std::string root_target;
     if (command_line->HasSwitch(kSwitchIdeRootTarget))
-      root_target = command_line->GetSwitchValueASCII(kSwitchIdeRootTarget);
+      root_target = command_line->GetSwitchValueString(kSwitchIdeRootTarget);
     bool res = QtCreatorWriter::RunAndWriteFile(build_settings, builder, err,
                                                 root_target);
     if (res && !quiet) {
@@ -299,14 +309,14 @@ bool RunIdeWriter(const std::string& ide,
     return res;
   } else if (ide == kSwitchIdeValueJson) {
     std::string file_name =
-        command_line->GetSwitchValueASCII(kSwitchJsonFileName);
+        command_line->GetSwitchValueString(kSwitchJsonFileName);
     if (file_name.empty())
       file_name = "project.json";
     std::string exec_script =
-        command_line->GetSwitchValueASCII(kSwitchJsonIdeScript);
+        command_line->GetSwitchValueString(kSwitchJsonIdeScript);
     std::string exec_script_extra_args =
-        command_line->GetSwitchValueASCII(kSwitchJsonIdeScriptArgs);
-    std::string filters = command_line->GetSwitchValueASCII(kSwitchFilters);
+        command_line->GetSwitchValueString(kSwitchJsonIdeScriptArgs);
+    std::string filters = command_line->GetSwitchValueString(kSwitchFilters);
 
     bool res = JSONProjectWriter::RunAndWriteFiles(
         build_settings, builder, file_name, exec_script, exec_script_extra_args,
@@ -342,26 +352,44 @@ bool RunRustProjectWriter(const BuildSettings* build_settings,
   return res;
 }
 
-bool RunCompileCommandsWriter(const BuildSettings* build_settings,
-                              const Builder& builder,
-                              Err* err) {
+bool RunCompileCommandsWriter(Setup& setup, Err* err) {
+  // The compilation database is written if either the .gn setting is set or if
+  // the command line flag is set. The command line flag takes precedence.
   const base::CommandLine* command_line =
       base::CommandLine::ForCurrentProcess();
+  bool has_legacy_switch =
+      command_line->HasSwitch(kSwitchExportCompileCommands);
+
+  bool has_patterns = !setup.export_compile_commands().empty();
+  if (!has_legacy_switch && !has_patterns)
+    return true;  // No compilation database needs to be written.
+
   bool quiet = command_line->HasSwitch(switches::kQuiet);
   base::ElapsedTimer timer;
 
-  std::string file_name = "compile_commands.json";
-  std::string target_filters =
-      command_line->GetSwitchValueASCII(kSwitchExportCompileCommands);
+  // The compilation database file goes in the build directory.
+  SourceFile output_file =
+      setup.build_settings().build_dir().ResolveRelativeFile(
+          Value(nullptr, "compile_commands.json"), err);
+  if (output_file.is_null())
+    return false;
+  base::FilePath output_path = setup.build_settings().GetFullPath(output_file);
+
+  std::optional<std::string> legacy_target_filters;
+  if (has_legacy_switch) {
+    legacy_target_filters =
+        command_line->GetSwitchValueString(kSwitchExportCompileCommands);
+  }
 
-  bool res = CompileCommandsWriter::RunAndWriteFiles(
-      build_settings, builder, file_name, target_filters, quiet, err);
-  if (res && !quiet) {
+  bool ok = CompileCommandsWriter::RunAndWriteFiles(
+      &setup.build_settings(), setup.builder().GetAllResolvedTargets(),
+      setup.export_compile_commands(), legacy_target_filters, output_path, err);
+  if (ok && !quiet) {
     OutputString("Generating compile_commands took " +
                  base::Int64ToString(timer.Elapsed().InMilliseconds()) +
                  "ms\n");
   }
-  return res;
+  return ok;
 }
 
 bool RunNinjaPostProcessTools(const BuildSettings* build_settings,
@@ -399,7 +427,7 @@ bool RunNinjaPostProcessTools(const BuildSettings* build_settings,
       return false;
     }
 
-    if(!InvokeNinjaRecompactTool(ninja_executable, build_dir, err)) {
+    if (!InvokeNinjaRecompactTool(ninja_executable, build_dir, err)) {
       return false;
     }
   }
@@ -516,6 +544,34 @@ Xcode Flags
       "legacy" - Legacy Build system
       "new" - New Build System
 
+  --xcode-configs=<config_name_list>
+      Configure the list of build configuration supported by the generated
+      project. If specified, must be a list of semicolon-separated strings.
+      If ommitted, a single configuration will be used in the generated
+      project derived from the build directory.
+
+  --xcode-config-build-dir=<string>
+      If present, must be a path relative to the source directory. It will
+      default to $root_out_dir if ommitted. The path is assumed to point to
+      the directory where ninja needs to be invoked. This variable can be
+      used to build for multiple configuration / platform / environment from
+      the same generated Xcode project (assuming that the user has created a
+      gn build directory with the correct args.gn for each).
+
+      One useful value is to use Xcode variables such as '${CONFIGURATION}'
+      or '${EFFECTIVE_PLATFORM}'.
+
+  --xcode-additional-files-patterns=<pattern_list>
+      If present, must be a list of semicolon-separated file patterns. It
+      will be used to add all files matching the pattern located in the
+      source tree to the project. It can be used to add, e.g. documentation
+      files to the project to allow easily edit them.
+
+  --xcode-additional-files-roots=<path_list>
+      If present, must be a list of semicolon-separated paths. It will be used
+      as roots when looking for additional files to add. If ommitted, defaults
+      to "//".
+
   --ninja-executable=<string>
       Can be used to specify the ninja executable to use when building.
 
@@ -572,21 +628,37 @@ Compilation Database
       replay of individual compilations independent of the build system.
       This is an unstable format and likely to change without warning.
 
+  --add-export-compile-commands=<label_pattern>
+      Adds an additional label pattern (see "gn help label_pattern") of a
+      target to add to the compilation database. This pattern is appended to any
+      list values specified in the export_compile_commands variable in the
+      .gn file (see "gn help dotfile"). This allows the user to add additional
+      targets to the compilation database that the project doesn't add by default.
+
+      To add more than one value, specify this switch more than once. Each
+      invocation adds an additional label pattern.
+
+      Example:
+        --add-export-compile-commands=//tools:my_tool
+        --add-export-compile-commands="//base/*"
+
   --export-compile-commands[=<target_name1,target_name2...>]
-      Produces a compile_commands.json file in the root of the build directory
-      containing an array of “command objects”, where each command object
-      specifies one way a translation unit is compiled in the project. If a list
-      of target_name is supplied, only targets that are reachable from any
-      target in any build file whose name is target_name will be used for
-      “command objects” generation, otherwise all available targets will be used.
-      This is used for various Clang-based tooling, allowing for the replay of
-      individual compilations independent of the build system.
-      e.g. "foo" will match:
-      - "//path/to/src:foo"
-      - "//other/path:foo"
-      - "//foo:foo"
+      DEPRECATED https://bugs.chromium.org/p/gn/issues/detail?id=302.
+      Please use --add-export-compile-commands for per-user configuration, and
+      the "export_compile_commands" value in the project-level .gn file (see
+      "gn help dotfile") for per-project configuration.
+
+      Overrides the value of the export_compile_commands in the .gn file (see
+      "gn help dotfile") as well as the --add-export-compile-commands switch.
+
+      Unlike the .gn setting, this switch takes a legacy format which is a list
+      of target names that are matched in any directory. For example, "foo" will
+      match:
+       - "//path/to/src:foo"
+       - "//other/path:foo"
+       - "//foo:foo"
       and not match:
-      - "//foo:bar"
+       - "//foo:bar"
 )";
 
 int RunGen(const std::vector<std::string>& args) {
@@ -613,10 +685,20 @@ int RunGen(const std::vector<std::string>& args) {
       base::CommandLine::ForCurrentProcess();
   if (command_line->HasSwitch(kSwitchCheck)) {
     setup->set_check_public_headers(true);
-    if (command_line->GetSwitchValueASCII(kSwitchCheck) == "system")
+    if (command_line->GetSwitchValueString(kSwitchCheck) == "system")
       setup->set_check_system_includes(true);
   }
 
+  // If this is a regeneration, replace existing build.ninja and build.ninja.d
+  // with just enough for ninja to call GN and regenerate ninja files. This
+  // removes any potential soon-to-be-dangling references and ensures that
+  // regeneration can be restarted if interrupted.
+  if (command_line->HasSwitch(switches::kRegeneration)) {
+    if (!commands::PrepareForRegeneration(&setup->build_settings())) {
+      return false;
+    }
+  }
+
   // Cause the load to also generate the ninja files for each target.
   TargetWriteInfo write_info;
   setup->builder().set_resolved_and_generated_callback(
@@ -665,15 +747,13 @@ int RunGen(const std::vector<std::string>& args) {
     return 1;
 
   if (command_line->HasSwitch(kSwitchIde) &&
-      !RunIdeWriter(command_line->GetSwitchValueASCII(kSwitchIde),
+      !RunIdeWriter(command_line->GetSwitchValueString(kSwitchIde),
                     &setup->build_settings(), setup->builder(), &err)) {
     err.PrintToStdout();
     return 1;
   }
 
-  if (command_line->HasSwitch(kSwitchExportCompileCommands) &&
-      !RunCompileCommandsWriter(&setup->build_settings(), setup->builder(),
-                                &err)) {
+  if (!RunCompileCommandsWriter(*setup, &err)) {
     err.PrintToStdout();
     return 1;
   }
diff --git a/gn/src/gn/command_meta.cc b/gn/src/gn/command_meta.cc
index aa5e88c38ba..25f6de06bbd 100644
--- a/gn/src/gn/command_meta.cc
+++ b/gn/src/gn/command_meta.cc
@@ -87,9 +87,9 @@ int RunMeta(const std::vector<std::string>& args) {
     return 1;
 
   const base::CommandLine* cmdline = base::CommandLine::ForCurrentProcess();
-  std::string rebase_dir = cmdline->GetSwitchValueASCII("rebase");
-  std::string data_keys_str = cmdline->GetSwitchValueASCII("data");
-  std::string walk_keys_str = cmdline->GetSwitchValueASCII("walk");
+  std::string rebase_dir = cmdline->GetSwitchValueString("rebase");
+  std::string data_keys_str = cmdline->GetSwitchValueString("data");
+  std::string walk_keys_str = cmdline->GetSwitchValueString("walk");
 
   std::vector<std::string> inputs(args.begin() + 1, args.end());
 
@@ -119,9 +119,8 @@ int RunMeta(const std::vector<std::string>& args) {
   if (rebase_dir.empty()) {
     rebase_source_dir = SourceDir();
   }
-  std::vector<Value> result =
-      WalkMetadata(targets, data_keys, walk_keys, rebase_source_dir,
-                   &targets_walked, &err);
+  std::vector<Value> result = WalkMetadata(
+      targets, data_keys, walk_keys, rebase_source_dir, &targets_walked, &err);
   if (err.has_error()) {
     err.PrintToStdout();
     return 1;
diff --git a/gn/src/gn/commands.cc b/gn/src/gn/commands.cc
index 24a16b1357b..f81f7abb024 100644
--- a/gn/src/gn/commands.cc
+++ b/gn/src/gn/commands.cc
@@ -4,12 +4,15 @@
 
 #include "gn/commands.h"
 
+#include <fstream>
 #include <optional>
 
 #include "base/command_line.h"
 #include "base/environment.h"
+#include "base/files/file_util.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
+#include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "gn/builder.h"
 #include "gn/config_values_extractors.h"
@@ -17,9 +20,12 @@
 #include "gn/item.h"
 #include "gn/label.h"
 #include "gn/label_pattern.h"
+#include "gn/ninja_build_writer.h"
 #include "gn/setup.h"
 #include "gn/standard_out.h"
+#include "gn/switches.h"
 #include "gn/target.h"
+#include "util/atomic_write.h"
 #include "util/build_config.h"
 
 namespace commands {
@@ -127,45 +133,12 @@ bool ResolveStringFromCommandLineInput(
   return true;
 }
 
-enum TargetPrintingMode {
-  TARGET_PRINT_BUILDFILE,
-  TARGET_PRINT_LABEL,
-  TARGET_PRINT_OUTPUT,
-};
-
 // Retrieves the target printing mode based on the command line flags for the
 // current process. Returns true on success. On error, prints a message to the
 // console and returns false.
-bool GetTargetPrintingMode(TargetPrintingMode* mode) {
-  std::string switch_key = "as";
-  const base::CommandLine* cmdline = base::CommandLine::ForCurrentProcess();
-
-  if (!cmdline->HasSwitch(switch_key)) {
-    // Default to labels.
-    *mode = TARGET_PRINT_LABEL;
-    return true;
-  }
-
-  std::string value = cmdline->GetSwitchValueASCII(switch_key);
-  if (value == "buildfile") {
-    *mode = TARGET_PRINT_BUILDFILE;
-    return true;
-  }
-  if (value == "label") {
-    *mode = TARGET_PRINT_LABEL;
-    return true;
-  }
-  if (value == "output") {
-    *mode = TARGET_PRINT_OUTPUT;
-    return true;
-  }
-
-  Err(Location(), "Invalid value for \"--as\".",
-      "I was expecting \"buildfile\", \"label\", or \"output\" but you\n"
-      "said \"" +
-          value + "\".")
-      .PrintToStdout();
-  return false;
+bool GetTargetPrintingMode(CommandSwitches::TargetPrintMode* mode) {
+  *mode = CommandSwitches::Get().target_print_mode();
+  return true;
 }
 
 // Returns the target type filter based on the command line flags for the
@@ -176,72 +149,20 @@ bool GetTargetPrintingMode(TargetPrintingMode* mode) {
 // will never be returned. Code applying the filters should apply Target::ACTION
 // to both ACTION and ACTION_FOREACH.
 bool GetTargetTypeFilter(Target::OutputType* type) {
-  std::string switch_key = "type";
-  const base::CommandLine* cmdline = base::CommandLine::ForCurrentProcess();
-
-  if (!cmdline->HasSwitch(switch_key)) {
-    // Default to unknown -> no filtering.
-    *type = Target::UNKNOWN;
-    return true;
-  }
-
-  std::string value = cmdline->GetSwitchValueASCII(switch_key);
-  if (value == "group") {
-    *type = Target::GROUP;
-    return true;
-  }
-  if (value == "executable") {
-    *type = Target::EXECUTABLE;
-    return true;
-  }
-  if (value == "shared_library") {
-    *type = Target::SHARED_LIBRARY;
-    return true;
-  }
-  if (value == "loadable_module") {
-    *type = Target::LOADABLE_MODULE;
-    return true;
-  }
-  if (value == "static_library") {
-    *type = Target::STATIC_LIBRARY;
-    return true;
-  }
-  if (value == "source_set") {
-    *type = Target::SOURCE_SET;
-    return true;
-  }
-  if (value == "copy") {
-    *type = Target::COPY_FILES;
-    return true;
-  }
-  if (value == "action") {
-    *type = Target::ACTION;
-    return true;
-  }
-
-  Err(Location(), "Invalid value for \"--type\".").PrintToStdout();
-  return false;
+  *type = CommandSwitches::Get().target_type();
+  return true;
 }
 
 // Applies any testonly filtering specified on the command line to the given
 // target set. On failure, prints an error and returns false.
 bool ApplyTestonlyFilter(std::vector<const Target*>* targets) {
-  const base::CommandLine* cmdline = base::CommandLine::ForCurrentProcess();
-  std::string testonly_key = "testonly";
+  CommandSwitches::TestonlyMode testonly_mode =
+      CommandSwitches::Get().testonly_mode();
 
-  if (targets->empty() || !cmdline->HasSwitch(testonly_key))
+  if (targets->empty() || testonly_mode == CommandSwitches::TESTONLY_NONE)
     return true;
 
-  std::string testonly_value = cmdline->GetSwitchValueASCII(testonly_key);
-  bool testonly = false;
-  if (testonly_value == "true") {
-    testonly = true;
-  } else if (testonly_value != "false") {
-    Err(Location(), "Bad value for --testonly.",
-        "I was expecting --testonly=true or --testonly=false.")
-        .PrintToStdout();
-    return false;
-  }
+  bool testonly = (testonly_mode == CommandSwitches::TESTONLY_TRUE);
 
   // Filter into a copy of the vector, then replace the output.
   std::vector<const Target*> result;
@@ -409,6 +330,14 @@ std::optional<HowTargetContainsFile> TargetContainsFile(
   return std::nullopt;
 }
 
+std::string ToUTF8(base::FilePath::StringType in) {
+#if defined(OS_WIN)
+  return base::UTF16ToUTF8(in);
+#else
+  return in;
+#endif
+}
+
 }  // namespace
 
 CommandInfo::CommandInfo()
@@ -438,13 +367,172 @@ const CommandInfoMap& GetCommands() {
     INSERT_COMMAND(Outputs)
     INSERT_COMMAND(Path)
     INSERT_COMMAND(Refs)
-    INSERT_COMMAND(CleanStale);
+    INSERT_COMMAND(CleanStale)
 
 #undef INSERT_COMMAND
   }
   return info_map;
 }
 
+// static
+CommandSwitches CommandSwitches::s_global_switches_ = {};
+
+// static
+bool CommandSwitches::Init(const base::CommandLine& cmdline) {
+  CHECK(!s_global_switches_.is_initialized())
+      << "Only call this once from main()";
+  return s_global_switches_.InitFrom(cmdline);
+}
+
+// static
+const CommandSwitches& CommandSwitches::Get() {
+  CHECK(s_global_switches_.is_initialized())
+      << "Missing previous succesful call to CommandSwitches::Init()";
+  return s_global_switches_;
+}
+
+// static
+CommandSwitches CommandSwitches::Set(CommandSwitches new_switches) {
+  CHECK(s_global_switches_.is_initialized())
+      << "Missing previous succesful call to CommandSwitches::Init()";
+  CommandSwitches result = std::move(s_global_switches_);
+  s_global_switches_ = std::move(new_switches);
+  return result;
+}
+
+bool CommandSwitches::InitFrom(const base::CommandLine& cmdline) {
+  CommandSwitches result;
+  result.initialized_ = true;
+  result.has_quiet_ = cmdline.HasSwitch("a");
+  result.has_force_ = cmdline.HasSwitch("force");
+  result.has_all_ = cmdline.HasSwitch("all");
+  result.has_blame_ = cmdline.HasSwitch("blame");
+  result.has_tree_ = cmdline.HasSwitch("tree");
+  result.has_format_json_ = cmdline.GetSwitchValueString("format") == "json";
+  result.has_default_toolchain_ =
+      cmdline.HasSwitch(switches::kDefaultToolchain);
+
+  result.has_check_generated_ = cmdline.HasSwitch("check-generated");
+  result.has_check_system_ = cmdline.HasSwitch("check-system");
+  result.has_public_ = cmdline.HasSwitch("public");
+  result.has_with_data_ = cmdline.HasSwitch("with-data");
+
+  std::string_view target_print_switch = "as";
+  if (cmdline.HasSwitch(target_print_switch)) {
+    std::string value = cmdline.GetSwitchValueString(target_print_switch);
+    if (value == "buildfile") {
+      result.target_print_mode_ = TARGET_PRINT_BUILDFILE;
+    } else if (value == "label") {
+      result.target_print_mode_ = TARGET_PRINT_LABEL;
+    } else if (value == "output") {
+      result.target_print_mode_ = TARGET_PRINT_OUTPUT;
+    } else {
+      Err(Location(), "Invalid value for \"--as\".",
+          "I was expecting \"buildfile\", \"label\", or \"output\" but you\n"
+          "said \"" +
+              value + "\".")
+          .PrintToStdout();
+      return false;
+    }
+  }
+
+  std::string_view target_type_switch = "type";
+  if (cmdline.HasSwitch(target_type_switch)) {
+    std::string value = cmdline.GetSwitchValueString(target_type_switch);
+    static const struct {
+      const char* name;
+      Target::OutputType type;
+    } kTypes[] = {
+        {"group", Target::GROUP},
+        {"executable", Target::EXECUTABLE},
+        {"shared_library", Target::SHARED_LIBRARY},
+        {"loadable_module", Target::LOADABLE_MODULE},
+        {"static_library", Target::STATIC_LIBRARY},
+        {"source_set", Target::SOURCE_SET},
+        {"copy", Target::COPY_FILES},
+        {"action", Target::ACTION},
+    };
+    bool found = false;
+    for (const auto& type : kTypes) {
+      if (value == type.name) {
+        result.target_type_ = type.type;
+        found = true;
+        break;
+      }
+    }
+    if (!found) {
+      Err(Location(), "Invalid value for \"--type\".").PrintToStdout();
+      return false;
+    }
+  }
+  std::string_view testonly_switch = "testonly";
+  if (cmdline.HasSwitch(testonly_switch)) {
+    std::string value = cmdline.GetSwitchValueString(testonly_switch);
+    if (value == "true") {
+      result.testonly_mode_ = TESTONLY_TRUE;
+    } else if (value == "false") {
+      result.testonly_mode_ = TESTONLY_FALSE;
+    } else {
+      Err(Location(), "Bad value for --testonly.",
+          "I was expecting --testonly=true or --testonly=false.")
+          .PrintToStdout();
+      return false;
+    }
+  }
+
+  result.meta_rebase_dir_ = cmdline.GetSwitchValueString("rebase");
+  result.meta_data_keys_ = cmdline.GetSwitchValueString("data");
+  result.meta_walk_keys_ = cmdline.GetSwitchValueString("walk");
+  *this = result;
+  return true;
+}
+
+bool PrepareForRegeneration(const BuildSettings* settings) {
+  // Write a .d file for the build which references a nonexistent file.
+  // This will make Ninja always mark the build as dirty.
+  base::FilePath build_ninja_d_file(settings->GetFullPath(
+      SourceFile(settings->build_dir().value() + "build.ninja.d")));
+  std::string dummy_depfile("build.ninja.stamp: nonexistent_file.gn\n");
+  if (util::WriteFileAtomically(build_ninja_d_file, dummy_depfile.data(),
+                                static_cast<int>(dummy_depfile.size())) == -1) {
+    Err(Location(), std::string("Failed to write build.ninja.d."))
+        .PrintToStdout();
+    return false;
+  }
+
+  // Write a stripped down build.ninja file with just the commands needed
+  // for ninja to call GN and regenerate ninja files.
+  base::FilePath build_ninja_path(settings->GetFullPath(
+      SourceFile(settings->build_dir().value() + "build.ninja")));
+  std::ifstream build_ninja_file(ToUTF8(build_ninja_path.value()));
+  if (!build_ninja_file) {
+    // Couldn't open the build.ninja file.
+    Err(Location(), "Couldn't open build.ninja in this directory.",
+        "Try running \"gn gen\" on it and then re-running \"gn clean\".")
+        .PrintToStdout();
+    return false;
+  }
+  std::string build_commands =
+      NinjaBuildWriter::ExtractRegenerationCommands(build_ninja_file);
+  if (build_commands.empty()) {
+    Err(Location(), "Unexpected build.ninja contents in this directory.",
+        "Try running \"gn gen\" on it and then re-running \"gn clean\".")
+        .PrintToStdout();
+    return false;
+  }
+  // Close build.ninja or else WriteFileAtomically will fail on Windows.
+  build_ninja_file.close();
+  if (util::WriteFileAtomically(build_ninja_path, build_commands.data(),
+                                static_cast<int>(build_commands.size())) ==
+      -1) {
+    Err(Location(), std::string("Failed to write build.ninja."))
+        .PrintToStdout();
+    return false;
+  }
+
+  return true;
+}
+
 const Target* ResolveTargetFromCommandLineString(
     Setup* setup,
     const std::string& label_string) {
@@ -583,17 +671,18 @@ void FilterAndPrintTargets(std::vector<const Target*>* targets,
   if (!ApplyTypeFilter(targets))
     return;
 
-  TargetPrintingMode printing_mode = TARGET_PRINT_LABEL;
+  CommandSwitches::TargetPrintMode printing_mode =
+      CommandSwitches::TARGET_PRINT_LABEL;
   if (targets->empty() || !GetTargetPrintingMode(&printing_mode))
     return;
   switch (printing_mode) {
-    case TARGET_PRINT_BUILDFILE:
+    case CommandSwitches::TARGET_PRINT_BUILDFILE:
       PrintTargetsAsBuildfiles(*targets, out);
       break;
-    case TARGET_PRINT_LABEL:
+    case CommandSwitches::TARGET_PRINT_LABEL:
       PrintTargetsAsLabels(*targets, out);
       break;
-    case TARGET_PRINT_OUTPUT:
+    case CommandSwitches::TARGET_PRINT_OUTPUT:
       PrintTargetsAsOutputs(*targets, out);
       break;
   }
diff --git a/gn/src/gn/commands.h b/gn/src/gn/commands.h
index 4824b7904c2..702bf0cd378 100644
--- a/gn/src/gn/commands.h
+++ b/gn/src/gn/commands.h
@@ -23,6 +23,10 @@ class SourceFile;
 class Target;
 class Toolchain;
 
+namespace base {
+class CommandLine;
+}  // namespace base
+
 // Each "Run" command returns the value we should return from main().
 
 namespace commands {
@@ -116,8 +120,136 @@ using CommandInfoMap = std::map<std::string_view, CommandInfo>;
 
 const CommandInfoMap& GetCommands();
 
+// Command switches as flags and enums -----------------------------------------
+
+// A class that models a set of command-line flags and values that
+// can affect the output of various GN commands. For example --tree
+// can be used with `gn desc <out_dir> <label> deps --tree`.
+//
+// Each flag or value is checked by an accessor method which returns
+// a boolean or an enum.
+//
+// Use CommandSwitches::Get() to get a reference to the current
+// global set of switches for the process.
+//
+// Use CommandSwitches::Set() to update its value. This may be
+// useful when implementing a REPL in GN, where each evaluation
+// might need a different set of command switches.
+class CommandSwitches {
+ public:
+  // Default constructor.
+  CommandSwitches() = default;
+
+  // For --quiet, used by `refs`.
+  bool has_quiet() const { return has_quiet_; }
+
+  // For --force, used by `check`.
+  bool has_force() const { return has_force_; }
+
+  // For --all, used by `desc` and `refs`.
+  bool has_all() const { return has_all_; }
+
+  // For --blame used by `desc`.
+  bool has_blame() const { return has_blame_; }
+
+  // For --tree used by `desc` and `refs`.
+  bool has_tree() const { return has_tree_; }
+
+  // For --format=json used by `desc`.
+  bool has_format_json() const { return has_format_json_; }
+
+  // For --default-toolchain used by `desc`, `refs`.
+  bool has_default_toolchain() const { return has_default_toolchain_; }
+
+  // For --check-generated
+  bool has_check_generated() const { return has_check_generated_; }
+
+  // For --check-system
+  bool has_check_system() const { return has_check_system_; }
+
+  // For --public
+  bool has_public() const { return has_public_; }
+
+  // For --with-data
+  bool has_with_data() const { return has_with_data_; }
+
+  // For --as=(buildtype|label|output).
+  enum TargetPrintMode {
+    TARGET_PRINT_BUILDFILE,
+    TARGET_PRINT_LABEL,
+    TARGET_PRINT_OUTPUT,
+  };
+  TargetPrintMode target_print_mode() const { return target_print_mode_; }
+
+  // For --type=TARGET_TYPE
+  Target::OutputType target_type() const { return target_type_; }
+
+  enum TestonlyMode {
+    TESTONLY_NONE,   // no --testonly used.
+    TESTONLY_FALSE,  // --testonly=false
+    TESTONLY_TRUE,   // --testonly=true
+  };
+  TestonlyMode testonly_mode() const { return testonly_mode_; }
+
+  // For --rebase, --walk and --data in `gn meta`
+  std::string meta_rebase_dir() const { return meta_rebase_dir_; }
+  std::string meta_data_keys() const { return meta_data_keys_; }
+  std::string meta_walk_keys() const { return meta_walk_keys_; }
+
+  // Initialize the global set from a given command line.
+  // Must be called early from main(). On success return true,
+  // on failure return false after printing an error message.
+  static bool Init(const base::CommandLine& cmdline);
+
+  // Retrieve a reference to the current global set of command switches.
+  static const CommandSwitches& Get();
+
+  // Change the current global set of command switches, and return
+  // the previous value.
+  static CommandSwitches Set(CommandSwitches new_switches);
+
+ private:
+  bool is_initialized() const { return initialized_; }
+
+  bool InitFrom(const base::CommandLine&);
+
+  static CommandSwitches s_global_switches_;
+
+  bool initialized_ = false;
+  bool has_quiet_ = false;
+  bool has_force_ = false;
+  bool has_all_ = false;
+  bool has_blame_ = false;
+  bool has_tree_ = false;
+  bool has_format_json_ = false;
+  bool has_default_toolchain_ = false;
+  bool has_check_generated_ = false;
+  bool has_check_system_ = false;
+  bool has_public_ = false;
+  bool has_with_data_ = false;
+
+  TargetPrintMode target_print_mode_ = TARGET_PRINT_LABEL;
+  Target::OutputType target_type_ = Target::UNKNOWN;
+  TestonlyMode testonly_mode_ = TESTONLY_NONE;
+
+  std::string meta_rebase_dir_;
+  std::string meta_data_keys_;
+  std::string meta_walk_keys_;
+};
+
 // Helper functions for some commands ------------------------------------------
 
+// Modifies the existing build.ninja to only contain the commands necessary to
+// run GN and regenerate and build.ninja.d such that build.ninja will be
+// treated as dirty and regenerated.
+//
+// This is used by commands like gen and clean before they modify or delete
+// other ninja files, and ensures that ninja can still call GN if the commands
+// are interrupted before completion.
+//
+// On error, returns false.
+bool PrepareForRegeneration(const BuildSettings* settings);
+
 // Given a setup that has already been run and some command-line input,
 // resolves that input as a target label and returns the corresponding target.
 // On failure, returns null and prints the error to the standard output.
diff --git a/gn/src/gn/compile_commands_writer.cc b/gn/src/gn/compile_commands_writer.cc
index 16f2a1a90e9..23d6029da3f 100644
--- a/gn/src/gn/compile_commands_writer.cc
+++ b/gn/src/gn/compile_commands_writer.cc
@@ -66,7 +66,7 @@ std::string FlagsGetter(RecursiveWriterConfig config,
   RecursiveTargetConfigToStream<T>(config, target, getter, writer, out);
   base::EscapeJSONString(out.str(), false, &result);
   return result;
-};
+}
 
 void SetupCompileFlags(const Target* target,
                        PathOutput& path_output,
@@ -105,7 +105,7 @@ void SetupCompileFlags(const Target* target,
     std::ostringstream out;
     WriteOneFlag(config, target, substitution, has_precompiled_headers,
                  tool_name, getter, opts, path_output, out,
-                 /*write_substitution=*/false);
+                 /*write_substitution=*/false, /*indent=*/false);
     base::EscapeJSONString(out.str(), false, &result);
     return result;
   };
@@ -299,68 +299,125 @@ std::string CompileCommandsWriter::RenderJSON(
 
 bool CompileCommandsWriter::RunAndWriteFiles(
     const BuildSettings* build_settings,
-    const Builder& builder,
-    const std::string& file_name,
-    const std::string& target_filters,
-    bool quiet,
+    const std::vector<const Target*>& all_targets,
+    const std::vector<LabelPattern>& patterns,
+    const std::optional<std::string>& legacy_target_filters,
+    const base::FilePath& output_path,
     Err* err) {
-  SourceFile output_file = build_settings->build_dir().ResolveRelativeFile(
-      Value(nullptr, file_name), err);
-  if (output_file.is_null())
+  std::vector<const Target*> to_write = CollectTargets(
+      build_settings, all_targets, patterns, legacy_target_filters, err);
+  if (err->has_error())
     return false;
 
-  base::FilePath output_path = build_settings->GetFullPath(output_file);
-
-  std::vector<const Target*> all_targets = builder.GetAllResolvedTargets();
-
-  std::set<std::string> target_filters_set;
-  for (auto& target :
-       base::SplitString(target_filters, ",", base::TRIM_WHITESPACE,
-                         base::SPLIT_WANT_NONEMPTY)) {
-    target_filters_set.insert(target);
-  }
-
   StringOutputBuffer json;
   std::ostream output_to_json(&json);
-  if (target_filters_set.empty()) {
-    OutputJSON(build_settings, all_targets, output_to_json);
-  } else {
-    std::vector<const Target*> preserved_targets =
-        FilterTargets(all_targets, target_filters_set);
-    OutputJSON(build_settings, preserved_targets, output_to_json);
-  }
+  OutputJSON(build_settings, to_write, output_to_json);
 
   return json.WriteToFileIfChanged(output_path, err);
 }
 
-std::vector<const Target*> CompileCommandsWriter::FilterTargets(
+std::vector<const Target*> CompileCommandsWriter::CollectTargets(
+    const BuildSettings* build_setting,
     const std::vector<const Target*>& all_targets,
-    const std::set<std::string>& target_filters_set) {
-  std::vector<const Target*> preserved_targets;
+    const std::vector<LabelPattern>& patterns,
+    const std::optional<std::string>& legacy_target_filters,
+    Err* err) {
+  if (legacy_target_filters && legacy_target_filters->empty()) {
+    // The legacy filter was specified but has no parameter. This matches
+    // everything and we can skip any other kinds of matching.
+    return all_targets;
+  }
 
-  TargetSet visited;
-  for (auto& target : all_targets) {
-    if (target_filters_set.count(target->label().name())) {
-      VisitDeps(target, &visited);
+  // Collect the first level of target matches. These are the ones that the
+  // patterns match directly.
+  std::vector<const Target*> input_targets;
+  for (const Target* target : all_targets) {
+    if (LabelPattern::VectorMatches(patterns, target->label()))
+      input_targets.push_back(target);
+  }
+
+  // Add in any legacy filter matches.
+  if (legacy_target_filters) {
+    std::vector<const Target*> legacy_matches =
+        FilterLegacyTargets(all_targets, *legacy_target_filters);
+
+    // This can produce some duplicates with the patterns but the "collect
+    // deps" phase will eliminate them.
+    input_targets.insert(input_targets.end(), legacy_matches.begin(),
+                         legacy_matches.end());
+  }
+
+  return CollectDepsOfMatches(input_targets);
+}
+
+std::vector<const Target*> CompileCommandsWriter::CollectDepsOfMatches(
+    const std::vector<const Target*>& input_targets) {
+  // The current set of matched targets.
+  TargetSet collected;
+
+  // Represents the next layer of the breadth-first seach. These are all targets
+  // that we haven't checked so far.
+  std::vector<const Target*> frontier;
+
+  // Collect the first level of target matches specified in the input. There may
+  // be duplicates so we still need to do the set checking.
+  // patterns match directly.
+  for (const Target* target : input_targets) {
+    if (!collected.contains(target)) {
+      collected.add(target);
+      frontier.push_back(target);
     }
   }
 
-  preserved_targets.reserve(visited.size());
-  // Preserve the original ordering of all_targets
-  // to allow easier debugging and testing.
-  for (auto& target : all_targets) {
-    if (visited.contains(target)) {
-      preserved_targets.push_back(target);
+  // Collects the dependencies for the next level of iteration. This could be
+  // inside the loop but is kept outside to avoid reallocating in every
+  // iteration.
+  std::vector<const Target*> next_frontier;
+
+  // Loop for each level of the search.
+  while (!frontier.empty()) {
+    for (const Target* target : frontier) {
+      // Check the target's dependencies.
+      for (const auto& pair : target->GetDeps(Target::DEPS_ALL)) {
+        if (!collected.contains(pair.ptr)) {
+          // New dependency found.
+          collected.add(pair.ptr);
+          next_frontier.push_back(pair.ptr);
+        }
+      }
     }
+
+    // Swap to the new level and clear out the next one without deallocating the
+    // buffer (in most STL implementations, clear() doesn't free the existing
+    // buffer).
+    std::swap(frontier, next_frontier);
+    next_frontier.clear();
+  }
+
+  // Convert to vector for output.
+  std::vector<const Target*> output;
+  output.reserve(collected.size());
+  for (const Target* target : collected) {
+    output.push_back(target);
   }
-  return preserved_targets;
+  return output;
 }
 
-void CompileCommandsWriter::VisitDeps(const Target* target,
-                                      TargetSet* visited) {
-  if (visited->add(target)) {
-    for (const auto& pair : target->GetDeps(Target::DEPS_ALL)) {
-      VisitDeps(pair.ptr, visited);
-    }
+std::vector<const Target*> CompileCommandsWriter::FilterLegacyTargets(
+    const std::vector<const Target*>& all_targets,
+    const std::string& target_filter_string) {
+  std::set<std::string> target_filters_set;
+  for (auto& target :
+       base::SplitString(target_filter_string, ",", base::TRIM_WHITESPACE,
+                         base::SPLIT_WANT_NONEMPTY)) {
+    target_filters_set.insert(target);
   }
+
+  std::vector<const Target*> result;
+  for (auto& target : all_targets) {
+    if (target_filters_set.count(target->label().name()))
+      result.push_back(target);
+  }
+
+  return result;
 }
diff --git a/gn/src/gn/compile_commands_writer.h b/gn/src/gn/compile_commands_writer.h
index 03006c8a9eb..6a006ef887c 100644
--- a/gn/src/gn/compile_commands_writer.h
+++ b/gn/src/gn/compile_commands_writer.h
@@ -5,7 +5,11 @@
 #ifndef TOOLS_GN_COMPILE_COMMANDS_WRITER_H_
 #define TOOLS_GN_COMPILE_COMMANDS_WRITER_H_
 
+#include <optional>
+#include <vector>
+
 #include "gn/err.h"
+#include "gn/label_pattern.h"
 #include "gn/target.h"
 
 class Builder;
@@ -13,30 +17,49 @@ class BuildSettings;
 
 class CompileCommandsWriter {
  public:
-  // Write compile commands into a json file located by parameter file_name.
+  // Writes a compilation database to the given file name consisting of the
+  // recursive dependencies of all targets that match or are dependencies of
+  // targets that match any given pattern.
+  //
+  // The legacy target filters takes a deprecated list of comma-separated target
+  // names ("target_name1,target_name2...") which are matched against targets in
+  // any directory. This is passed as an optional to encapsulate the legacy
+  // behavior that providing the switch with no patterns matches everything, but
+  // not passing the flag (nullopt for the function parameter) matches nothing.
   //
-  // Parameter target_filters should be in "target_name1,target_name2..."
-  // format. If it is not empty, only targets that are reachable from targets
-  // in target_filters are used to generate compile commands.
+  // The union of the legacy matches and the target patterns are used.
   //
-  // Parameter quiet is not used.
-  static bool RunAndWriteFiles(const BuildSettings* build_setting,
-                               const Builder& builder,
-                               const std::string& file_name,
-                               const std::string& target_filters,
-                               bool quiet,
-                               Err* err);
+  // TODO(https://bugs.chromium.org/p/gn/issues/detail?id=302):
+  // Remove this legacy target filters behavior.
+  static bool RunAndWriteFiles(
+      const BuildSettings* build_setting,
+      const std::vector<const Target*>& all_targets,
+      const std::vector<LabelPattern>& patterns,
+      const std::optional<std::string>& legacy_target_filters,
+      const base::FilePath& output_path,
+      Err* err);
+
+  // Collects all the targets whose commands should get written as part of
+  // RunAndWriteFiles() (separated out for unit testing).
+  static std::vector<const Target*> CollectTargets(
+      const BuildSettings* build_setting,
+      const std::vector<const Target*>& all_targets,
+      const std::vector<LabelPattern>& patterns,
+      const std::optional<std::string>& legacy_target_filters,
+      Err* err);
 
   static std::string RenderJSON(const BuildSettings* build_settings,
                                 std::vector<const Target*>& all_targets);
 
-  static std::vector<const Target*> FilterTargets(
-      const std::vector<const Target*>& all_targets,
-      const std::set<std::string>& target_filters_set);
+  // Does a depth-first search of the graph starting at the input target and
+  // collects all recursive dependencies of those targets.
+  static std::vector<const Target*> CollectDepsOfMatches(
+      const std::vector<const Target*>& input_targets);
 
- private:
-  // This function visits the deps graph of a target in a DFS fashion.
-  static void VisitDeps(const Target* target, TargetSet* visited);
+  // Performs the legacy target_name filtering.
+  static std::vector<const Target*> FilterLegacyTargets(
+      const std::vector<const Target*>& all_targets,
+      const std::string& target_filter_string);
 };
 
 #endif  // TOOLS_GN_COMPILE_COMMANDS_WRITER_H_
diff --git a/gn/src/gn/compile_commands_writer_unittest.cc b/gn/src/gn/compile_commands_writer_unittest.cc
index 29e6a573699..2f0294c0530 100644
--- a/gn/src/gn/compile_commands_writer_unittest.cc
+++ b/gn/src/gn/compile_commands_writer_unittest.cc
@@ -19,6 +19,10 @@
 
 namespace {
 
+bool CompareLabel(const Target* a, const Target* b) {
+  return a->label() < b->label();
+}
+
 // InputConversion needs a global scheduler object.
 class CompileCommandsTest : public TestWithScheduler {
  public:
@@ -29,6 +33,15 @@ class CompileCommandsTest : public TestWithScheduler {
   const TestWithScope& setup() { return setup_; }
   const Toolchain* toolchain() { return setup_.toolchain(); }
 
+  // Returns true if the two target vectors contain the same targets, order
+  // independent.
+  bool VectorsEqual(std::vector<const Target*> a,
+                    std::vector<const Target*> b) const {
+    std::sort(a.begin(), a.end(), &CompareLabel);
+    std::sort(b.begin(), b.end(), &CompareLabel);
+    return a == b;
+  }
+
  private:
   TestWithScope setup_;
 };
@@ -586,55 +599,138 @@ TEST_F(CompileCommandsTest, EscapedFlags) {
   EXPECT_EQ(expected, out);
 }
 
-TEST_F(CompileCommandsTest, CompDBFilter) {
+TEST_F(CompileCommandsTest, CollectTargets) {
+  // Contruct the dependency tree:
+  //
+  //   //foo:bar1
+  //     //base:base
+  //   //foo:bar2
+  //     //base:i18n
+  //       //base:base
+  //       //third_party:icu
+  //   //random:random
   Err err;
-
   std::vector<const Target*> targets;
+
+  Target icu_target(settings(), Label(SourceDir("//third_party/"), "icu"));
+  icu_target.set_output_type(Target::SOURCE_SET);
+  icu_target.visibility().SetPublic();
+  icu_target.SetToolchain(toolchain());
+  ASSERT_TRUE(icu_target.OnResolved(&err));
+  targets.push_back(&icu_target);
+
+  Target base_target(settings(), Label(SourceDir("//base/"), "base"));
+  base_target.set_output_type(Target::SOURCE_SET);
+  base_target.visibility().SetPublic();
+  base_target.SetToolchain(toolchain());
+  ASSERT_TRUE(base_target.OnResolved(&err));
+  targets.push_back(&base_target);
+
+  Target base_i18n(settings(), Label(SourceDir("//base/"), "i18n"));
+  base_i18n.set_output_type(Target::SOURCE_SET);
+  base_i18n.visibility().SetPublic();
+  base_i18n.private_deps().push_back(LabelTargetPair(&icu_target));
+  base_i18n.public_deps().push_back(LabelTargetPair(&base_target));
+  base_i18n.SetToolchain(toolchain());
+  ASSERT_TRUE(base_i18n.OnResolved(&err))
+      << err.message() << " " << err.help_text();
+  targets.push_back(&base_i18n);
+
   Target target1(settings(), Label(SourceDir("//foo/"), "bar1"));
   target1.set_output_type(Target::SOURCE_SET);
-  target1.sources().push_back(SourceFile("//foo/input1.c"));
-  target1.config_values().cflags_c().push_back("-DCONFIG=\"/config\"");
+  target1.public_deps().push_back(LabelTargetPair(&base_target));
   target1.SetToolchain(toolchain());
   ASSERT_TRUE(target1.OnResolved(&err));
   targets.push_back(&target1);
 
   Target target2(settings(), Label(SourceDir("//foo/"), "bar2"));
   target2.set_output_type(Target::SOURCE_SET);
-  target2.sources().push_back(SourceFile("//foo/input2.c"));
-  target2.config_values().cflags_c().push_back("-DCONFIG=\"/config\"");
+  target2.public_deps().push_back(LabelTargetPair(&base_i18n));
   target2.SetToolchain(toolchain());
   ASSERT_TRUE(target2.OnResolved(&err));
   targets.push_back(&target2);
 
-  Target target3(settings(), Label(SourceDir("//foo/"), "bar3"));
-  target3.set_output_type(Target::SOURCE_SET);
-  target3.sources().push_back(SourceFile("//foo/input3.c"));
-  target3.config_values().cflags_c().push_back("-DCONFIG=\"/config\"");
-  target3.SetToolchain(toolchain());
-  ASSERT_TRUE(target3.OnResolved(&err));
-  targets.push_back(&target3);
-
-  target1.private_deps().push_back(LabelTargetPair(&target2));
-  target1.private_deps().push_back(LabelTargetPair(&target3));
-
-  CompileCommandsWriter writer;
-
-  std::set<std::string> filter1;
-  std::vector<const Target*> test_results1 =
-      writer.FilterTargets(targets, filter1);
-  ASSERT_TRUE(test_results1.empty());
-
-  std::set<std::string> filter2;
-  filter2.insert(target1.label().name());
-  std::vector<const Target*> test_results2 =
-      writer.FilterTargets(targets, filter2);
-  ASSERT_EQ(test_results2, targets);
-
-  std::set<std::string> filter3;
-  filter3.insert(target2.label().name());
-  std::vector<const Target*> test_result3 =
-      writer.FilterTargets(targets, filter3);
-  std::vector<const Target*> expected_results3;
-  expected_results3.push_back(&target2);
-  ASSERT_EQ(test_result3, expected_results3);
+  Target random_target(settings(), Label(SourceDir("//random/"), "random"));
+  random_target.set_output_type(Target::SOURCE_SET);
+  random_target.SetToolchain(toolchain());
+  ASSERT_TRUE(random_target.OnResolved(&err));
+  targets.push_back(&random_target);
+
+  // Collect everything, the result should match the input.
+  const std::string source_root("/home/me/build/");
+  LabelPattern wildcard_pattern = LabelPattern::GetPattern(
+      SourceDir(), source_root, Value(nullptr, "//*"), &err);
+  ASSERT_FALSE(err.has_error());
+  std::vector<const Target*> output = CompileCommandsWriter::CollectTargets(
+      build_settings(), targets, std::vector<LabelPattern>{wildcard_pattern},
+      std::nullopt, &err);
+  EXPECT_TRUE(VectorsEqual(output, targets));
+
+  // Collect nothing.
+  output = CompileCommandsWriter::CollectTargets(build_settings(), targets,
+                                                 std::vector<LabelPattern>(),
+                                                 std::nullopt, &err);
+  EXPECT_TRUE(output.empty());
+
+  // Collect all deps of "//foo/*".
+  LabelPattern foo_wildcard = LabelPattern::GetPattern(
+      SourceDir(), source_root, Value(nullptr, "//foo/*"), &err);
+  ASSERT_FALSE(err.has_error());
+  output = CompileCommandsWriter::CollectTargets(
+      build_settings(), targets, std::vector<LabelPattern>{foo_wildcard},
+      std::nullopt, &err);
+
+  // The result should be everything except "random".
+  std::sort(output.begin(), output.end(), &CompareLabel);
+  ASSERT_EQ(5u, output.size());
+  EXPECT_EQ(&base_target, output[0]);
+  EXPECT_EQ(&base_i18n, output[1]);
+  EXPECT_EQ(&target1, output[2]);
+  EXPECT_EQ(&target2, output[3]);
+  EXPECT_EQ(&icu_target, output[4]);
+
+  // Collect everything using the legacy filter (present string but empty).
+  output = CompileCommandsWriter::CollectTargets(build_settings(), targets,
+                                                 std::vector<LabelPattern>{},
+                                                 std::string(), &err);
+  EXPECT_TRUE(VectorsEqual(output, targets));
+
+  // Collect all deps of "bar2" using the legacy filter.
+  output = CompileCommandsWriter::CollectTargets(build_settings(), targets,
+                                                 std::vector<LabelPattern>{},
+                                                 std::string("bar2"), &err);
+  std::sort(output.begin(), output.end(), &CompareLabel);
+  ASSERT_EQ(4u, output.size());
+  EXPECT_EQ(&base_target, output[0]);
+  EXPECT_EQ(&base_i18n, output[1]);
+  EXPECT_EQ(&target2, output[2]);
+  EXPECT_EQ(&icu_target, output[3]);
+
+  // Collect all deps of "bar1" and "bar2" using the legacy filter.
+  output = CompileCommandsWriter::CollectTargets(
+      build_settings(), targets, std::vector<LabelPattern>{},
+      std::string("bar2,bar1"), &err);
+  std::sort(output.begin(), output.end(), &CompareLabel);
+  ASSERT_EQ(5u, output.size());
+  EXPECT_EQ(&base_target, output[0]);
+  EXPECT_EQ(&base_i18n, output[1]);
+  EXPECT_EQ(&target1, output[2]);
+  EXPECT_EQ(&target2, output[3]);
+  EXPECT_EQ(&icu_target, output[4]);
+
+  // Combine the legacy (bar1) and pattern (bar2) filters, we should get the
+  // union.
+  LabelPattern foo_bar2 = LabelPattern::GetPattern(
+      SourceDir(), source_root, Value(nullptr, "//foo:bar2"), &err);
+  ASSERT_FALSE(err.has_error());
+  output = CompileCommandsWriter::CollectTargets(
+      build_settings(), targets, std::vector<LabelPattern>{foo_bar2},
+      std::string("bar1"), &err);
+  std::sort(output.begin(), output.end(), &CompareLabel);
+  ASSERT_EQ(5u, output.size());
+  EXPECT_EQ(&base_target, output[0]);
+  EXPECT_EQ(&base_i18n, output[1]);
+  EXPECT_EQ(&target1, output[2]);
+  EXPECT_EQ(&target2, output[3]);
+  EXPECT_EQ(&icu_target, output[4]);
 }
diff --git a/gn/src/gn/config_values_generator.h b/gn/src/gn/config_values_generator.h
index d006140102e..ff9cd03d692 100644
--- a/gn/src/gn/config_values_generator.h
+++ b/gn/src/gn/config_values_generator.h
@@ -37,10 +37,10 @@ class ConfigValuesGenerator {
 };
 
 // For using in documentation for functions which use this.
-#define CONFIG_VALUES_VARS_HELP                                            \
-  "  Flags: cflags, cflags_c, cflags_cc, cflags_objc, cflags_objcc,\n"     \
-  "         asmflags, defines, include_dirs, inputs, ldflags, lib_dirs,\n" \
-  "         libs, precompiled_header, precompiled_source, rustflags,\n"    \
-  "         rustenv, swiftflags, testonly\n"
+#define CONFIG_VALUES_VARS_HELP                                        \
+  "  Flags: asmflags, cflags, cflags_c, cflags_cc, cflags_objc,\n"     \
+  "         cflags_objcc, defines, include_dirs, inputs, ldflags,\n"   \
+  "         lib_dirs, libs, precompiled_header, precompiled_source,\n" \
+  "         rustenv, rustflags, swiftflags, testonly\n"
 
 #endif  // TOOLS_GN_CONFIG_VALUES_GENERATOR_H_
diff --git a/gn/src/gn/exec_process.cc b/gn/src/gn/exec_process.cc
index 69d631e9ebd..e1e123fbbbe 100644
--- a/gn/src/gn/exec_process.cc
+++ b/gn/src/gn/exec_process.cc
@@ -253,6 +253,8 @@ bool ExecProcess(const base::CommandLine& cmdline,
       argv_cstr[argv.size()] = nullptr;
       execvp(argv_cstr[0], argv_cstr.get());
       _exit(127);
+      // Avoid `fall through` warning on some gcc versions.
+      break;
     }
     default:  // parent
     {
diff --git a/gn/src/gn/filesystem_utils.cc b/gn/src/gn/filesystem_utils.cc
index 64713782d2c..d0a1ee0edf2 100644
--- a/gn/src/gn/filesystem_utils.cc
+++ b/gn/src/gn/filesystem_utils.cc
@@ -1006,6 +1006,8 @@ OutputFile GetBuildDirAsOutputFile(const BuildDirContext& context,
     result.value().append("gen/");
   else if (type == BuildDirType::OBJ)
     result.value().append("obj/");
+  else if (type == BuildDirType::PHONY)
+    result.value().append("phony/");
   return result;
 }
 
@@ -1023,10 +1025,25 @@ OutputFile GetSubBuildDirAsOutputFile(const BuildDirContext& context,
   OutputFile result = GetBuildDirAsOutputFile(context, type);
 
   if (source_dir.is_source_absolute()) {
-    // The source dir is source-absolute, so we trim off the two leading
-    // slashes to append to the toolchain object directory.
-    result.value().append(&source_dir.value()[2],
-                          source_dir.value().size() - 2);
+    std::string_view build_dir = context.build_settings->build_dir().value();
+    std::string_view source_dir_path = source_dir.value();
+    if (source_dir_path.substr(0, build_dir.size()) == build_dir) {
+      // The source dir is source-absolute, but in the build directory
+      // (e.g. `//out/Debug/gen/src/foo.cc` or
+      // `//out/Debug/toolchain1/gen/foo.cc`), which happens for generated
+      // sources. In this case, remove the build directory prefix, and replace
+      // it with `BUILD_DIR`. This will create results like `obj/BUILD_DIR/gen`
+      // or `toolchain2/obj/BUILD_DIR/toolchain1/gen` which look surprising,
+      // but guarantee unicity.
+      result.value().append("BUILD_DIR/");
+      result.value().append(source_dir_path.substr(build_dir.size()));
+
+    } else {
+      // The source dir is source-absolute, so we trim off the two leading
+      // slashes to append to the toolchain object directory.
+      result.value().append(&source_dir.value()[2],
+                            source_dir.value().size() - 2);
+    }
   } else {
     // System-absolute.
     AppendFixedAbsolutePathSuffix(context.build_settings, source_dir, &result);
diff --git a/gn/src/gn/filesystem_utils.h b/gn/src/gn/filesystem_utils.h
index 2c826b5234f..590f9e34d41 100644
--- a/gn/src/gn/filesystem_utils.h
+++ b/gn/src/gn/filesystem_utils.h
@@ -222,6 +222,12 @@ enum class BuildDirType {
 
   // Output file directory.
   OBJ,
+
+  // Phony file directory. As the name implies, this is not a real file
+  // directory, but a path that is used for the declaration of phony targets.
+  // This is done to avoid duplicate target names between real files and phony
+  // aliases that point to them.
+  PHONY,
 };
 
 // In different contexts, different information is known about the toolchain in
diff --git a/gn/src/gn/format_test_data/084.gn b/gn/src/gn/format_test_data/084.gn
new file mode 100644
index 00000000000..b58b634011e
--- /dev/null
+++ b/gn/src/gn/format_test_data/084.gn
@@ -0,0 +1,34 @@
+# Checks that lists are also sorted if concatenated during an assignment
+other_sources = [
+  "f.cc",
+  "e.cc"
+] + [
+  "h.cc",
+  "g.cc"
+]
+
+other_sources = [
+  ":f",
+  ":e"
+] + [
+  ":h",
+  "g"
+]
+
+executable("foo") {
+  sources = [
+    "b.cc",
+    "a.cc"
+  ] + [
+    "d.cc",
+    "c.cc"
+  ] + other_sources
+
+  deps = [
+    ":b",
+    ":a"
+  ] + [
+    ":d",
+    ":c"
+  ] + other_sources
+}
diff --git a/gn/src/gn/format_test_data/084.golden b/gn/src/gn/format_test_data/084.golden
new file mode 100644
index 00000000000..fa1803794a2
--- /dev/null
+++ b/gn/src/gn/format_test_data/084.golden
@@ -0,0 +1,38 @@
+# Checks that lists are also sorted if concatenated during an assignment
+other_sources = [
+                  "e.cc",
+                  "f.cc",
+                ] +
+                [
+                  "g.cc",
+                  "h.cc",
+                ]
+
+other_sources = [
+                  ":e",
+                  ":f",
+                ] +
+                [
+                  ":h",
+                  "g",
+                ]
+
+executable("foo") {
+  sources = [
+              "a.cc",
+              "b.cc",
+            ] +
+            [
+              "c.cc",
+              "d.cc",
+            ] + other_sources
+
+  deps = [
+           ":a",
+           ":b",
+         ] +
+         [
+           ":c",
+           ":d",
+         ] + other_sources
+}
diff --git a/gn/src/gn/function_get_target_outputs.cc b/gn/src/gn/function_get_target_outputs.cc
index fa851f3c47c..c9f10c0fe0f 100644
--- a/gn/src/gn/function_get_target_outputs.cc
+++ b/gn/src/gn/function_get_target_outputs.cc
@@ -105,8 +105,9 @@ Value RunGetTargetOutputs(Scope* scope,
   }
 
   if (!target) {
+    bool with_toolchain = !scope->settings()->is_default();
     *err = Err(function, "Target not found in this context.",
-               label.GetUserVisibleName(false) +
+               label.GetUserVisibleName(with_toolchain) +
                    "\nwas not found. get_target_outputs() can only be used for "
                    "targets\n"
                    "previously defined in the current file.");
diff --git a/gn/src/gn/functions.cc b/gn/src/gn/functions.cc
index 6294f79b712..59d97c44212 100644
--- a/gn/src/gn/functions.cc
+++ b/gn/src/gn/functions.cc
@@ -968,6 +968,68 @@ Value RunPrint(Scope* scope,
   return Value();
 }
 
+// print_stack_trace -----------------------------------------------------------
+
+const char kPrintStackTrace[] = "print_stack_trace";
+const char kPrintStackTrace_HelpShort[] =
+    "print_stack_trace: Prints a stack trace.";
+const char kPrintStackTrace_Help[] =
+    R"(print_stack_trace: Prints a stack trace.
+
+  Prints the current file location, and all template invocations that led up to
+  this location, to the console.
+
+Examples
+
+  template("foo"){
+    print_stack_trace()
+  }
+  template("bar"){
+    foo(target_name + ".foo") {
+      baz = invoker.baz
+    }
+  }
+  bar("lala") {
+    baz = 42
+  }
+
+  will print out the following:
+
+  print_stack_trace() initiated at  //build.gn:2
+    bar("lala")  //BUILD.gn:9
+    foo("lala.foo")  //BUILD.gn:5
+    print_stack_trace()  //BUILD.gn:2
+
+)";
+
+Value RunPrintStackTrace(Scope* scope,
+                         const FunctionCallNode* function,
+                         const std::vector<Value>& args,
+                         Err* err) {
+  std::string location_str = function->GetRange().begin().Describe(false);
+  std::string toolchain =
+      scope->settings()->toolchain_label().GetUserVisibleName(false);
+  std::string output =
+      "print_stack_trace() initiated at:  " + location_str + "  using: " + toolchain;
+  output.push_back('\n');
+
+  for (const auto& entry : scope->GetTemplateInvocationEntries()) {
+    output.append("  " + entry.Describe() + "\n");
+  }
+  output.append("  print_stack_trace()  " + location_str + "\n");
+
+  const BuildSettings::PrintCallback& cb =
+      scope->settings()->build_settings()->print_callback();
+  if (cb) {
+    cb(output);
+  } else {
+    printf("%s", output.c_str());
+    fflush(stdout);
+  }
+
+  return Value();
+}
+
 // split_list ------------------------------------------------------------------
 
 const char kSplitList[] = "split_list";
@@ -1393,6 +1455,7 @@ struct FunctionInfoInitializer {
     INSERT_FUNCTION(NotNeeded, false)
     INSERT_FUNCTION(Pool, false)
     INSERT_FUNCTION(Print, false)
+    INSERT_FUNCTION(PrintStackTrace, false)
     INSERT_FUNCTION(ProcessFileTemplate, false)
     INSERT_FUNCTION(ReadFile, false)
     INSERT_FUNCTION(RebasePath, false)
diff --git a/gn/src/gn/functions_target.cc b/gn/src/gn/functions_target.cc
index 7120b3f7512..4ca2c10550c 100644
--- a/gn/src/gn/functions_target.cc
+++ b/gn/src/gn/functions_target.cc
@@ -15,15 +15,22 @@
 
 #define DEPENDENT_CONFIG_VARS \
   "  Dependent configs: all_dependent_configs, public_configs\n"
-#define DEPS_VARS "  Deps: data_deps, deps, public_deps\n"
+#define DEPS_VARS \
+  "  Deps: assert_no_deps, data_deps, deps, public_deps, runtime_deps,\n" \
+  "        write_runtime_deps\n"
 #define GENERAL_TARGET_VARS                                                \
   "  General: check_includes, configs, data, friend, inputs, metadata,\n"  \
-  "           output_name, output_extension, public, sources, testonly,\n" \
+  "           output_extension, output_name, public, sources, testonly,\n" \
   "           visibility\n"
 #define RUST_VARS \
   "  Rust variables: aliased_deps, crate_root, crate_name\n"
 #define RUST_SHARED_VARS                                                 \
   "  Rust variables: aliased_deps, crate_root, crate_name, crate_type\n"
+#define ACTION_VARS \
+  "  Action variables: args, bridge_header, configs, data, depfile,\n" \
+  "                    framework_dirs, inputs, module_deps, module_name,\n" \
+  "                    outputs*, pool, response_file_contents, script*,\n" \
+  "                    sources\n"
 
 namespace functions {
 
@@ -138,6 +145,12 @@ Inputs
   It is recommended you put inputs to your script in the "sources" variable,
   and stuff like other Python files required to run your script in the "inputs"
   variable.
+
+  Actions can take the configs and public_configs lists, as well as any of the
+  configs variables (defines, include_dirs, etc.) set directly on the target.
+  These behave exactly as they would on a binary target and can be accessed
+  using substitution patterns in the script args (see "gn help args") to
+  implement custom compiler-like tools.
 )"
 
     ACTION_DEPS
@@ -160,9 +173,10 @@ File name handling
     R"(
 Variables
 
-  args, data, data_deps, depfile, deps, inputs, metadata, outputs*, pool,
-  response_file_contents, script*, sources
-  * = required
+)" CONFIG_VALUES_VARS_HELP DEPENDENT_CONFIG_VARS DEPS_VARS GENERAL_TARGET_VARS
+ACTION_VARS
+
+R"(  * = required
 
 Example
 
@@ -230,9 +244,10 @@ File name handling
     R"(
 Variables
 
-  args, data, data_deps, depfile, deps, inputs, metadata, outputs*, pool,
-  response_file_contents, script*, sources*
-  * = required
+)" CONFIG_VALUES_VARS_HELP DEPENDENT_CONFIG_VARS DEPS_VARS GENERAL_TARGET_VARS
+ACTION_VARS
+
+R"(  * = required
 
 Example
 
@@ -294,7 +309,9 @@ const char kBundleData_Help[] =
 
 Variables
 
-  sources*, outputs*, deps, data_deps, metadata, public_deps, visibility
+)" DEPENDENT_CONFIG_VARS DEPS_VARS GENERAL_TARGET_VARS
+
+R"(  Bundle-specific: sources*, outputs*
   * = required
 
 Examples
@@ -380,11 +397,13 @@ Code signing
 
 Variables
 
-  bundle_root_dir, bundle_contents_dir, bundle_resources_dir,
-  bundle_executable_dir, bundle_deps_filter, deps, data_deps, public_deps,
-  visibility, product_type, code_signing_args, code_signing_script,
-  code_signing_sources, code_signing_outputs, xcode_extra_attributes,
-  xcode_test_application_name, partial_info_plist, metadata
+)" DEPENDENT_CONFIG_VARS DEPS_VARS GENERAL_TARGET_VARS
+
+R"(  Bundle vars: bundle_root_dir, bundle_contents_dir, bundle_resources_dir,
+               bundle_executable_dir, bundle_deps_filter, product_type,
+               code_signing_args, code_signing_script, code_signing_sources,
+               code_signing_outputs, xcode_extra_attributes,
+               xcode_test_application_name, partial_info_plist
 
 Example
 
@@ -516,6 +535,17 @@ File name handling
   (see "gn help source_expansion"). The placeholders will look like
   "{{source_name_part}}", for example.
 
+  If you want to copy the output of a previous build step, the target that
+  generates the file to copy must be reachable from the deps or public_deps of
+  the copy target.
+
+Variables
+
+)" DEPENDENT_CONFIG_VARS DEPS_VARS GENERAL_TARGET_VARS
+
+R"(  Copy variables: sources*, outputs*
+  * = required
+
 Examples
 
   # Write a rule that copies a checked-in DLL to the output directory.
@@ -532,6 +562,24 @@ Examples
     # names in the gen dir. This will just copy each file.
     outputs = [ "$target_gen_dir/{{source_file_part}}" ]
   }
+
+  # Copy the output of a generated executable.
+  copy("package_melon") {
+    # This example uses get_label_info() to compute the output directory of the
+    # dependency. This allows the copy rule to work regardless of the toolchain.
+    #
+    # In some cases (particularly actions defined previously in the same file)
+    # you can use get_target_outputs() to get the input file which can eliminate
+    # the assumptions about the output file name of the dependency.
+
+    input_dir = get_label_info("//src/tools/melon", "root_out_dir");
+    sources = [ "$input_dir/melon" ]
+
+    outputs = [ "$target_gen_dir/{{source_file_part}}" ]
+
+    # Depend on the target to build the file before copying.
+    deps = [ "//src/tools/melon" ]
+  }
 )";
 
 Value RunCopy(const FunctionCallNode* function,
@@ -584,7 +632,7 @@ const char kGroup_Help[] =
 
 Variables
 
-)" DEPS_VARS DEPENDENT_CONFIG_VARS
+)" DEPS_VARS DEPENDENT_CONFIG_VARS GENERAL_TARGET_VARS
 
     R"(
 Example
@@ -811,9 +859,9 @@ Value RunStaticLibrary(Scope* scope,
 
 const char kTarget[] = "target";
 const char kTarget_HelpShort[] =
-    "target: Declare an target with the given programmatic type.";
+    "target: Declare a target with the given programmatic type.";
 const char kTarget_Help[] =
-    R"(target: Declare an target with the given programmatic type.
+    R"(target: Declare a target with the given programmatic type.
 
   target(target_type_string, target_name_string) { ... }
 
@@ -830,6 +878,14 @@ const char kTarget_Help[] =
   Is equivalent to:
     source_set("doom_melon") {
 
+Common target variables
+
+)" DEPS_VARS DEPENDENT_CONFIG_VARS GENERAL_TARGET_VARS
+
+R"(
+  Targets will also have variables specific to that type, see "gn help <type>"
+  for more.
+
 Example
 
   if (foo_build_as_shared) {
@@ -897,6 +953,12 @@ const char kGeneratedFile_Help[] =
   Collected metadata, if specified, will be returned in postorder of
   dependencies. See the example for details.
 
+Variables
+
+)" DEPENDENT_CONFIG_VARS DEPS_VARS GENERAL_TARGET_VARS
+
+R"(  Generated file: contents, data_keys, rebase, walk_keys, output_conversion
+
 Example (metadata collection)
 
   Given the following targets defined in //base/BUILD.gn, where A depends on B
@@ -992,16 +1054,7 @@ Example (metadata collection)
       "../base/bar.cpp",  // from //base:b via //base:a
       "../base/foo.cpp",  // from //base:a
     ]
-
-
-Variables
-
-  contents
-  data_keys
-  rebase
-  walk_keys
-  output_conversion
-)" DEPS_VARS DEPENDENT_CONFIG_VARS;
+)";
 
 Value RunGeneratedFile(Scope* scope,
                        const FunctionCallNode* function,
diff --git a/gn/src/gn/functions_unittest.cc b/gn/src/gn/functions_unittest.cc
index 40ac5d9ced8..6498415bcce 100644
--- a/gn/src/gn/functions_unittest.cc
+++ b/gn/src/gn/functions_unittest.cc
@@ -457,3 +457,189 @@ TEST(Functions, NotNeeded) {
   ASSERT_FALSE(err.has_error())
       << err.message() << err.location().Describe(true);
 }
+
+TEST(Template, PrintStackTraceWithOneTemplate) {
+  TestWithScope setup;
+  TestParseInput input(
+      "template(\"foo\") {\n"
+      "  print(target_name)\n"
+      "  print(invoker.foo_value)\n"
+      "  print_stack_trace()\n"
+      "}\n"
+      "foo(\"lala\") {\n"
+      "  foo_value = 42\n"
+      "}");
+  ASSERT_FALSE(input.has_error());
+
+  Err err;
+  input.parsed()->Execute(setup.scope(), &err);
+  ASSERT_FALSE(err.has_error()) << err.message();
+
+  EXPECT_EQ(
+    "lala\n"
+    "42\n"
+    "print_stack_trace() initiated at:  //test:4  using: //toolchain:default\n"
+    "  foo(\"lala\")  //test:6\n"
+    "  print_stack_trace()  //test:4\n",
+    setup.print_output());
+}
+
+TEST(Template, PrintStackTraceWithNoTemplates) {
+  TestWithScope setup;
+  TestParseInput input("print_stack_trace()\n");
+  ASSERT_FALSE(input.has_error());
+
+  Err err;
+  input.parsed()->Execute(setup.scope(), &err);
+  ASSERT_FALSE(err.has_error()) << err.message() << "\n\n" << err.help_text();
+
+  EXPECT_EQ(
+    "print_stack_trace() initiated at:  //test:1  using: //toolchain:default\n"
+    "  print_stack_trace()  //test:1\n",
+    setup.print_output());
+}
+
+
+TEST(Template, PrintStackTraceWithNestedTemplates) {
+  TestWithScope setup;
+  TestParseInput input(
+      "template(\"foo\") {\n"
+      "  print(target_name)\n"
+      "  print(invoker.foo_value)\n"
+      "  print_stack_trace()\n"
+      "}\n"
+      "template(\"baz\") {\n"
+      "  foo(\"${target_name}.foo\") {\n"
+      "    foo_value = invoker.bar\n"
+      "  }\n"
+      "}\n"
+      "baz(\"lala\") {\n"
+      "  bar = 42\n"
+      "}");
+  ASSERT_FALSE(input.has_error());
+
+  Err err;
+  input.parsed()->Execute(setup.scope(), &err);
+  ASSERT_FALSE(err.has_error()) << err.message() << "\n\n" << err.help_text();
+
+  EXPECT_EQ(
+    "lala.foo\n"
+    "42\n"
+    "print_stack_trace() initiated at:  //test:4  using: //toolchain:default\n"
+    "  baz(\"lala\")  //test:11\n"
+    "  foo(\"lala.foo\")  //test:7\n"
+    "  print_stack_trace()  //test:4\n",
+    setup.print_output());
+}
+
+TEST(Template, PrintStackTraceWithNonTemplateScopes) {
+  TestWithScope setup;
+  TestParseInput input(
+      "template(\"foo\") {\n"
+      "  print(target_name)\n"
+      "  if (defined(invoker.foo_value)) {\n"
+      "    print(invoker.foo_value)\n"
+      "    print_stack_trace()\n"
+      "  }\n"
+      "}\n"
+      "template(\"baz\") {\n"
+      "  foo(\"${target_name}.foo\") {\n"
+      "    foo_value = invoker.bar\n"
+      "  }\n"
+      "}\n"
+      "baz(\"lala\") {\n"
+      "  bar = 42\n"
+      "}");
+  ASSERT_FALSE(input.has_error());
+
+  Err err;
+  input.parsed()->Execute(setup.scope(), &err);
+  ASSERT_FALSE(err.has_error()) << err.message() << "\n\n" << err.help_text();
+
+  EXPECT_EQ(
+    "lala.foo\n"
+    "42\n"
+    "print_stack_trace() initiated at:  //test:5  using: //toolchain:default\n"
+    "  baz(\"lala\")  //test:13\n"
+    "  foo(\"lala.foo\")  //test:9\n"
+    "  print_stack_trace()  //test:5\n",
+    setup.print_output());
+}
+
+TEST(Template, PrintStackTraceWithNonTemplateScopesBetweenTemplateInvocations) {
+  TestWithScope setup;
+  TestParseInput input(
+      "template(\"foo\") {\n"
+      "  print(target_name)\n"
+      "  if (defined(invoker.foo_value)) {\n"
+      "    print(invoker.foo_value)\n"
+      "    print_stack_trace()\n"
+      "  }\n"
+      "}\n"
+      "template(\"baz\") {\n"
+      "  if (invoker.bar == 42) {\n"
+      "    foo(\"${target_name}.foo\") {\n"
+      "      foo_value = invoker.bar\n"
+      "    }\n"
+      "  }\n"
+      "}\n"
+      "baz(\"lala\") {\n"
+      "  bar = 42\n"
+      "}");
+  ASSERT_FALSE(input.has_error());
+  Err err;
+  input.parsed()->Execute(setup.scope(), &err);
+  ASSERT_FALSE(err.has_error()) << err.message() << "\n\n" << err.help_text();
+
+  EXPECT_EQ(
+    "lala.foo\n"
+    "42\n"
+    "print_stack_trace() initiated at:  //test:5  using: //toolchain:default\n"
+    "  baz(\"lala\")  //test:15\n"
+    "  foo(\"lala.foo\")  //test:10\n"
+    "  print_stack_trace()  //test:5\n",
+    setup.print_output());
+}
+
+TEST(Template, PrintStackTraceWithTemplateDefinedWithinATemplate) {
+  TestWithScope setup;
+  TestParseInput input(
+      "template(\"foo\") {\n"
+      "  print(target_name)\n"
+      "  if (defined(invoker.foo_value)) {\n"
+      "    template(\"foo_internal\") {"
+      "      print(target_name)\n"
+      "      print(invoker.foo_internal_value)\n"
+      "      print_stack_trace()\n"
+      "    }\n"
+      "    foo_internal(target_name+\".internal\") {"
+      "      foo_internal_value = invoker.foo_value\n"
+      "    }\n"
+      "  }\n"
+      "}\n"
+      "template(\"baz\") {\n"
+      "  if (invoker.bar == 42) {\n"
+      "    foo(\"${target_name}.foo\") {\n"
+      "      foo_value = invoker.bar\n"
+      "    }\n"
+      "  }\n"
+      "}\n"
+      "baz(\"lala\") {\n"
+      "  bar = 42\n"
+      "}");
+  ASSERT_FALSE(input.has_error());
+  Err err;
+  input.parsed()->Execute(setup.scope(), &err);
+  ASSERT_FALSE(err.has_error()) << err.message() << "\n\n" << err.help_text();
+
+  EXPECT_EQ(
+    "lala.foo\n"
+    "lala.foo.internal\n"
+    "42\n"
+    "print_stack_trace() initiated at:  //test:6  using: //toolchain:default\n"
+    "  baz(\"lala\")  //test:19\n"
+    "  foo(\"lala.foo\")  //test:14\n"
+    "  foo_internal(\"lala.foo.internal\")  //test:8\n"
+    "  print_stack_trace()  //test:6\n",
+    setup.print_output());
+}
diff --git a/gn/src/gn/gn_main.cc b/gn/src/gn/gn_main.cc
index e839b322d38..e1a05177bee 100644
--- a/gn/src/gn/gn_main.cc
+++ b/gn/src/gn/gn_main.cc
@@ -63,6 +63,9 @@ int main(int argc, char** argv) {
     args.erase(args.begin());
   }
 
+  if (!commands::CommandSwitches::Init(cmdline))
+    return 1;
+
   const commands::CommandInfoMap& command_map = commands::GetCommands();
   commands::CommandInfoMap::const_iterator found_command =
       command_map.find(command);
diff --git a/gn/src/gn/header_checker.cc b/gn/src/gn/header_checker.cc
index 8d2d313fd80..7bad781402f 100644
--- a/gn/src/gn/header_checker.cc
+++ b/gn/src/gn/header_checker.cc
@@ -214,6 +214,16 @@ void HeaderChecker::AddTargetToFileMap(const Target* target, FileMap* dest) {
     files_to_public[source].is_public = default_public;
   }
 
+  // If the target includes some .swift files, it may also use a header file
+  // to provide bridging Objective-C code. This header needs to be considered
+  // as a source file with the default visibility.
+  if (target->has_swift_values()) {
+    const SourceFile& bridge_header = target->swift_values().bridge_header();
+    if (!bridge_header.is_null()) {
+      files_to_public[bridge_header].is_public = default_public;
+    }
+  }
+
   // Add in the public files, forcing them to public. This may overwrite some
   // entries, and it may add new ones.
   if (default_public)  // List only used when default is not public.
diff --git a/gn/src/gn/header_checker.h b/gn/src/gn/header_checker.h
index d4d2f9f20d5..55c925935d9 100644
--- a/gn/src/gn/header_checker.h
+++ b/gn/src/gn/header_checker.h
@@ -77,6 +77,8 @@ class HeaderChecker : public base::RefCountedThreadSafe<HeaderChecker> {
   FRIEND_TEST_ALL_PREFIXES(HeaderCheckerTest, SourceFileForInclude);
   FRIEND_TEST_ALL_PREFIXES(HeaderCheckerTest,
                            SourceFileForInclude_FileNotFound);
+  FRIEND_TEST_ALL_PREFIXES(HeaderCheckerTest,
+                           SourceFileForInclude_SwiftBridgeHeader);
   FRIEND_TEST_ALL_PREFIXES(HeaderCheckerTest, Friend);
 
   ~HeaderChecker();
diff --git a/gn/src/gn/header_checker_unittest.cc b/gn/src/gn/header_checker_unittest.cc
index a290d453183..2a168fd50f6 100644
--- a/gn/src/gn/header_checker_unittest.cc
+++ b/gn/src/gn/header_checker_unittest.cc
@@ -391,6 +391,16 @@ TEST_F(HeaderCheckerTest, SourceFileForInclude_FileNotFound) {
   EXPECT_FALSE(err.has_error());
 }
 
+TEST_F(HeaderCheckerTest, SourceFileForInclude_SwiftBridgeHeader) {
+  const SourceFile bridge_header("//a/bridge_header.h");
+  a_.swift_values().bridge_header() = bridge_header;
+  auto checker = CreateChecker();
+
+  HeaderChecker::FileMap file_map;
+  checker->AddTargetToFileMap(&a_, &file_map);
+  EXPECT_NE(file_map.find(bridge_header), file_map.end());
+}
+
 TEST_F(HeaderCheckerTest, Friend) {
   // Note: we have a public dependency chain A -> B -> C set up already.
   InputFile input_file(SourceFile("//some_file.cc"));
diff --git a/gn/src/gn/import_manager.cc b/gn/src/gn/import_manager.cc
index a4928bf10c2..69f44b48a79 100644
--- a/gn/src/gn/import_manager.cc
+++ b/gn/src/gn/import_manager.cc
@@ -125,14 +125,14 @@ bool ImportManager::DoImport(const SourceFile& file,
       if (TracingEnabled() &&
           TicksDelta(import_block_end, import_block_begin).InMilliseconds() >
               kImportBlockTraceThresholdMS) {
-        auto* import_block_trace =
-            new TraceItem(TraceItem::TRACE_IMPORT_BLOCK, file.value(),
-                          std::this_thread::get_id());
+        auto import_block_trace = std::make_unique<TraceItem>(
+            TraceItem::TRACE_IMPORT_BLOCK, file.value(),
+            std::this_thread::get_id());
         import_block_trace->set_begin(import_block_begin);
         import_block_trace->set_end(import_block_end);
         import_block_trace->set_toolchain(
             scope->settings()->toolchain_label().GetUserVisibleName(false));
-        AddTrace(import_block_trace);
+        AddTrace(std::move(import_block_trace));
       }
     }
 
diff --git a/gn/src/gn/json_project_writer.cc b/gn/src/gn/json_project_writer.cc
index a54e2548dc4..27368ff82d2 100644
--- a/gn/src/gn/json_project_writer.cc
+++ b/gn/src/gn/json_project_writer.cc
@@ -313,7 +313,6 @@ class SimpleJSONWriter {
 
         if (line_end == std::string_view::npos) {
           out_ << json;
-          ;
           comma_ = {};
           return;
         }
@@ -455,6 +454,9 @@ StringOutputBuffer JSONProjectWriter::GenerateJSON(
       base::Value toolchain{base::Value::Type::DICTIONARY};
       const auto& tools = tool_chain_kv.second->tools();
       for (const auto& tool_kv : tools) {
+        // Do not list builtin tools
+        if (tool_kv.second->AsBuiltin())
+          continue;
         base::Value tool_info{base::Value::Type::DICTIONARY};
         auto setIfNotEmptry = [&](const auto& key, const auto& value) {
           if (value.size())
diff --git a/gn/src/gn/ninja_action_target_writer.cc b/gn/src/gn/ninja_action_target_writer.cc
index bfceef90b8f..60d4204d8d3 100644
--- a/gn/src/gn/ninja_action_target_writer.cc
+++ b/gn/src/gn/ninja_action_target_writer.cc
@@ -80,9 +80,12 @@ void NinjaActionTargetWriter::Run() {
     if (target_->action_values().has_depfile()) {
       WriteDepfile(SourceFile());
     }
-    if (target_->action_values().pool().ptr) {
+
+    WriteNinjaVariablesForAction();
+
+    if (target_->pool().ptr) {
       out_ << "  pool = ";
-      out_ << target_->action_values().pool().ptr->GetNinjaName(
+      out_ << target_->pool().ptr->GetNinjaName(
           settings_->default_toolchain_label());
       out_ << std::endl;
     }
@@ -149,7 +152,8 @@ std::string NinjaActionTargetWriter::WriteRuleDefinition() {
   out_ << std::endl;
   out_ << "  description = ACTION " << target_label << std::endl;
   out_ << "  restat = 1" << std::endl;
-  const Tool* tool = target_->toolchain()->GetTool(GeneralTool::kGeneralToolAction);
+  const Tool* tool =
+      target_->toolchain()->GetTool(GeneralTool::kGeneralToolAction);
   if (tool && tool->pool().ptr) {
     out_ << "  pool = ";
     out_ << tool->pool().ptr->GetNinjaName(
@@ -204,13 +208,14 @@ void NinjaActionTargetWriter::WriteSourceRules(
         target_, settings_, sources[i],
         target_->action_values().rsp_file_contents().required_types(),
         args_escape_options, out_);
+    WriteNinjaVariablesForAction();
 
     if (target_->action_values().has_depfile()) {
       WriteDepfile(sources[i]);
     }
-    if (target_->action_values().pool().ptr) {
+    if (target_->pool().ptr) {
       out_ << "  pool = ";
-      out_ << target_->action_values().pool().ptr->GetNinjaName(
+      out_ << target_->pool().ptr->GetNinjaName(
           settings_->default_toolchain_label());
       out_ << std::endl;
     }
@@ -248,3 +253,10 @@ void NinjaActionTargetWriter::WriteDepfile(const SourceFile& source) {
     out_ << "  deps = gcc" << std::endl;
   }
 }
+
+void NinjaActionTargetWriter::WriteNinjaVariablesForAction() {
+  SubstitutionBits subst;
+  target_->action_values().args().FillRequiredTypes(&subst);
+  WriteRustCompilerVars(subst, /*indent=*/true, /*always_write=*/false);
+  WriteCCompilerVars(subst, /*indent=*/true, /*respect_source_types=*/false);
+}
diff --git a/gn/src/gn/ninja_action_target_writer.h b/gn/src/gn/ninja_action_target_writer.h
index ef91f4e1024..58b9489a9d0 100644
--- a/gn/src/gn/ninja_action_target_writer.h
+++ b/gn/src/gn/ninja_action_target_writer.h
@@ -50,6 +50,10 @@ class NinjaActionTargetWriter : public NinjaTargetWriter {
 
   void WriteDepfile(const SourceFile& source);
 
+  // Writes variables that we make available to all actions, irrespective
+  // of whether they're associated with a specific source file.
+  void WriteNinjaVariablesForAction();
+
   // Path output writer that doesn't do any escaping or quoting. It does,
   // however, convert slashes.  Used for
   // computing intermediate strings.
diff --git a/gn/src/gn/ninja_action_target_writer_unittest.cc b/gn/src/gn/ninja_action_target_writer_unittest.cc
index 80b125b8f30..d57f1492b13 100644
--- a/gn/src/gn/ninja_action_target_writer_unittest.cc
+++ b/gn/src/gn/ninja_action_target_writer_unittest.cc
@@ -5,6 +5,7 @@
 #include <algorithm>
 #include <sstream>
 
+#include "gn/config.h"
 #include "gn/ninja_action_target_writer.h"
 #include "gn/pool.h"
 #include "gn/substitution_list.h"
@@ -90,7 +91,7 @@ TEST(NinjaActionTargetWriter, ActionNoSourcesConsole) {
             Label(SourceDir("//"), "console", setup.toolchain()->label().dir(),
                   setup.toolchain()->label().name()));
   pool.set_depth(1);
-  target.action_values().set_pool(LabelPtrPair<Pool>(&pool));
+  target.set_pool(LabelPtrPair<Pool>(&pool));
 
   target.SetToolchain(setup.toolchain());
   ASSERT_TRUE(target.OnResolved(&err));
@@ -376,7 +377,7 @@ TEST(NinjaActionTargetWriter, ForEachWithPool) {
             Label(SourceDir("//foo/"), "pool", setup.toolchain()->label().dir(),
                   setup.toolchain()->label().name()));
   pool.set_depth(5);
-  target.action_values().set_pool(LabelPtrPair<Pool>(&pool));
+  target.set_pool(LabelPtrPair<Pool>(&pool));
 
   target.SetToolchain(setup.toolchain());
   ASSERT_TRUE(target.OnResolved(&err));
@@ -486,3 +487,63 @@ TEST(NinjaActionTargetWriter, NoTransitiveHardDeps) {
     EXPECT_EQ(expected_linux, out.str());
   }
 }
+
+TEST(NinjaActionTargetWriter, SeesConfig) {
+  Err err;
+  TestWithScope setup;
+
+  setup.build_settings()->set_python_path(
+      base::FilePath(FILE_PATH_LITERAL("/usr/bin/python")));
+
+  Config farcfg(setup.settings(), Label(SourceDir("//foo/"), "farcfg"));
+  farcfg.own_values().defines().push_back("MY_DEFINE2");
+  farcfg.own_values().cflags().push_back("-isysroot=baz");
+  farcfg.visibility().SetPublic();
+  ASSERT_TRUE(farcfg.OnResolved(&err));
+
+  Config cfgdep(setup.settings(), Label(SourceDir("//foo/"), "cfgdep"));
+  cfgdep.own_values().rustenv().push_back("my_rustenv");
+  cfgdep.own_values().include_dirs().push_back(SourceDir("//my_inc_dir/"));
+  cfgdep.own_values().defines().push_back("MY_DEFINE");
+  cfgdep.visibility().SetPublic();
+  cfgdep.configs().push_back(LabelConfigPair(&farcfg));
+  ASSERT_TRUE(cfgdep.OnResolved(&err));
+
+  Target foo(setup.settings(), Label(SourceDir("//foo/"), "foo"));
+  foo.set_output_type(Target::ACTION);
+  foo.visibility().SetPublic();
+  foo.sources().push_back(SourceFile("//foo/input1.txt"));
+  foo.action_values().set_script(SourceFile("//foo/script.py"));
+  foo.action_values().args() = SubstitutionList::MakeForTest(
+      "{{rustenv}}", "{{include_dirs}}", "{{defines}}", "{{cflags}}");
+  foo.configs().push_back(LabelConfigPair(&cfgdep));
+  foo.SetToolchain(setup.toolchain());
+  foo.action_values().outputs() =
+      SubstitutionList::MakeForTest("//out/Debug/foo.out");
+  ASSERT_TRUE(foo.OnResolved(&err));
+
+  {
+    std::ostringstream out;
+    NinjaActionTargetWriter writer(&foo, out);
+    writer.Run();
+
+    const char expected[] =
+        "rule __foo_foo___rule\n"
+        // These come from the args.
+        "  command = /usr/bin/python ../../foo/script.py ${rustenv} "
+        "${include_dirs} ${defines} ${cflags}\n"
+        "  description = ACTION //foo:foo()\n"
+        "  restat = 1\n"
+        "\n"
+        "build foo.out: __foo_foo___rule | ../../foo/script.py"
+        " ../../foo/input1.txt\n"
+        "  rustenv = my_rustenv\n"
+        "  defines = -DMY_DEFINE -DMY_DEFINE2\n"
+        "  include_dirs = -I../../my_inc_dir\n"
+        "  cflags = -isysroot=baz\n"
+        "\n"
+        "build obj/foo/foo.stamp: stamp foo.out\n";
+    std::string out_str = out.str();
+    EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+  }
+}
diff --git a/gn/src/gn/ninja_binary_target_writer.cc b/gn/src/gn/ninja_binary_target_writer.cc
index 48f485ad181..b960cc01bf5 100644
--- a/gn/src/gn/ninja_binary_target_writer.cc
+++ b/gn/src/gn/ninja_binary_target_writer.cc
@@ -15,6 +15,7 @@
 #include "gn/ninja_rust_binary_target_writer.h"
 #include "gn/ninja_target_command_util.h"
 #include "gn/ninja_utils.h"
+#include "gn/pool.h"
 #include "gn/settings.h"
 #include "gn/string_utils.h"
 #include "gn/substitution_writer.h"
@@ -156,7 +157,7 @@ void NinjaBinaryTargetWriter::ClassifyDependency(
   // don't link at all.
   bool can_link_libs = target_->IsFinal();
 
-  if (can_link_libs && dep->swift_values().builds_module())
+  if (can_link_libs && dep->builds_swift_module())
     classified_deps->swiftmodule_deps.push_back(dep);
 
   if (target_->source_types_used().RustSourceUsed() &&
@@ -275,7 +276,8 @@ void NinjaBinaryTargetWriter::WriteCompilerBuildLine(
     const std::vector<OutputFile>& extra_deps,
     const std::vector<OutputFile>& order_only_deps,
     const char* tool_name,
-    const std::vector<OutputFile>& outputs) {
+    const std::vector<OutputFile>& outputs,
+    bool can_write_source_info) {
   out_ << "build";
   path_output_.WriteFiles(out_, outputs);
 
@@ -292,6 +294,16 @@ void NinjaBinaryTargetWriter::WriteCompilerBuildLine(
     path_output_.WriteFiles(out_, order_only_deps);
   }
   out_ << std::endl;
+
+  if (!sources.empty() && can_write_source_info) {
+    out_ << "  "
+         << "source_file_part = " << sources[0].GetName();
+    out_ << std::endl;
+    out_ << "  "
+         << "source_name_part = "
+         << FindFilenameNoExtension(&sources[0].value());
+    out_ << std::endl;
+  }
 }
 
 void NinjaBinaryTargetWriter::WriteCustomLinkerFlags(
@@ -409,3 +421,12 @@ void NinjaBinaryTargetWriter::WriteSwiftModules(
     swiftmodule_path_output.WriteFile(out, swiftmodule);
   }
 }
+
+void NinjaBinaryTargetWriter::WritePool(std::ostream& out) {
+  if (target_->pool().ptr) {
+    out << "  pool = ";
+    out << target_->pool().ptr->GetNinjaName(
+        settings_->default_toolchain_label());
+    out << std::endl;
+  }
+}
diff --git a/gn/src/gn/ninja_binary_target_writer.h b/gn/src/gn/ninja_binary_target_writer.h
index e53e28eb245..c7b6eead554 100644
--- a/gn/src/gn/ninja_binary_target_writer.h
+++ b/gn/src/gn/ninja_binary_target_writer.h
@@ -63,7 +63,8 @@ class NinjaBinaryTargetWriter : public NinjaTargetWriter {
                               const std::vector<OutputFile>& extra_deps,
                               const std::vector<OutputFile>& order_only_deps,
                               const char* tool_name,
-                              const std::vector<OutputFile>& outputs);
+                              const std::vector<OutputFile>& outputs,
+                              bool can_write_source_info = true);
 
   void WriteLinkerFlags(std::ostream& out,
                         const Tool* tool,
@@ -75,6 +76,7 @@ class NinjaBinaryTargetWriter : public NinjaTargetWriter {
   void WriteSwiftModules(std::ostream& out,
                          const Tool* tool,
                          const std::vector<OutputFile>& swiftmodules);
+  void WritePool(std::ostream& out);
 
   void AddSourceSetFiles(const Target* source_set,
                          UniqueVector<OutputFile>* obj_files) const;
diff --git a/gn/src/gn/ninja_binary_target_writer_unittest.cc b/gn/src/gn/ninja_binary_target_writer_unittest.cc
index 970aa82f7d1..5fd066b68f8 100644
--- a/gn/src/gn/ninja_binary_target_writer_unittest.cc
+++ b/gn/src/gn/ninja_binary_target_writer_unittest.cc
@@ -42,7 +42,11 @@ TEST_F(NinjaBinaryTargetWriterTest, CSources) {
       "target_output_name = bar\n"
       "\n"
       "build obj/foo/bar.input1.o: cxx ../../foo/input1.cc\n"
+      "  source_file_part = input1.cc\n"
+      "  source_name_part = input1\n"
       "build obj/foo/bar.input2.o: cxx ../../foo/input2.cc\n"
+      "  source_file_part = input2.cc\n"
+      "  source_name_part = input2\n"
       "\n"
       "build obj/foo/bar.stamp: stamp obj/foo/bar.input1.o "
       "obj/foo/bar.input2.o ../../foo/input3.o ../../foo/input4.obj\n";
@@ -137,6 +141,8 @@ TEST_F(NinjaBinaryTargetWriterTest, Inputs) {
         "\n"
         "build obj/foo/bar.source1.o: cxx ../../foo/source1.cc | "
         "../../foo/input1 ../../foo/input2\n"
+        "  source_file_part = source1.cc\n"
+        "  source_name_part = source1\n"
         "\n"
         "build obj/foo/bar.stamp: stamp obj/foo/bar.source1.o\n";
     std::string out_str = out.str();
@@ -172,8 +178,12 @@ TEST_F(NinjaBinaryTargetWriterTest, Inputs) {
         "../../foo/input1 ../../foo/input2\n"
         "build obj/foo/bar.source1.o: cxx ../../foo/source1.cc | "
         "obj/foo/bar.inputs.stamp\n"
+        "  source_file_part = source1.cc\n"
+        "  source_name_part = source1\n"
         "build obj/foo/bar.source2.o: cxx ../../foo/source2.cc | "
         "obj/foo/bar.inputs.stamp\n"
+        "  source_file_part = source2.cc\n"
+        "  source_name_part = source2\n"
         "\n"
         "build obj/foo/bar.stamp: stamp obj/foo/bar.source1.o "
         "obj/foo/bar.source2.o\n";
diff --git a/gn/src/gn/ninja_build_writer.cc b/gn/src/gn/ninja_build_writer.cc
index 908c5df15e9..e39e5591a40 100644
--- a/gn/src/gn/ninja_build_writer.cc
+++ b/gn/src/gn/ninja_build_writer.cc
@@ -29,6 +29,7 @@
 #include "gn/switches.h"
 #include "gn/target.h"
 #include "gn/trace.h"
+#include "util/atomic_write.h"
 #include "util/build_config.h"
 #include "util/exe_path.h"
 
@@ -110,7 +111,7 @@ base::CommandLine GetSelfInvocationCommandLine(
         i->first != switches::kDotfile && i->first != switches::kArgs) {
       std::string escaped_value =
           EscapeString(FilePathToUTF8(i->second), escape_shell, nullptr);
-      cmdline.AppendSwitchASCII(i->first, escaped_value);
+      cmdline.AppendSwitch(i->first, escaped_value);
     }
   }
 
@@ -261,16 +262,16 @@ bool NinjaBuildWriter::RunAndWriteFile(const BuildSettings* build_settings,
   if (!gen.Run(err))
     return false;
 
-  // Unconditionally write the build.ninja. Ninja's build-out-of-date checking
-  // will re-run GN when any build input is newer than build.ninja, so any time
-  // the build is updated, build.ninja's timestamp needs to updated also, even
-  // if the contents haven't been changed.
+  // Unconditionally write the build.ninja. Ninja's build-out-of-date
+  // checking will re-run GN when any build input is newer than build.ninja, so
+  // any time the build is updated, build.ninja's timestamp needs to updated
+  // also, even if the contents haven't been changed.
   base::FilePath ninja_file_name(build_settings->GetFullPath(
       SourceFile(build_settings->build_dir().value() + "build.ninja")));
   base::CreateDirectory(ninja_file_name.DirName());
   std::string ninja_contents = file.str();
-  if (base::WriteFile(ninja_file_name, ninja_contents.data(),
-                      static_cast<int>(ninja_contents.size())) !=
+  if (util::WriteFileAtomically(ninja_file_name, ninja_contents.data(),
+                                static_cast<int>(ninja_contents.size())) !=
       static_cast<int>(ninja_contents.size()))
     return false;
 
@@ -278,14 +279,43 @@ bool NinjaBuildWriter::RunAndWriteFile(const BuildSettings* build_settings,
   base::FilePath dep_file_name(build_settings->GetFullPath(
       SourceFile(build_settings->build_dir().value() + "build.ninja.d")));
   std::string dep_contents = depfile.str();
-  if (base::WriteFile(dep_file_name, dep_contents.data(),
-                      static_cast<int>(dep_contents.size())) !=
+  if (util::WriteFileAtomically(dep_file_name, dep_contents.data(),
+                                static_cast<int>(dep_contents.size())) !=
       static_cast<int>(dep_contents.size()))
     return false;
 
+  // Finally, write the empty build.ninja.stamp file. This is the output
+  // expected by the first of the two ninja rules used to accomplish
+  // regeneration.
+
+  base::FilePath stamp_file_name(build_settings->GetFullPath(
+      SourceFile(build_settings->build_dir().value() + "build.ninja.stamp")));
+  std::string stamp_contents;
+  if (util::WriteFileAtomically(stamp_file_name, stamp_contents.data(),
+                                static_cast<int>(stamp_contents.size())) !=
+      static_cast<int>(stamp_contents.size()))
+    return false;
+
   return true;
 }
 
+// static
+std::string NinjaBuildWriter::ExtractRegenerationCommands(
+    std::istream& build_ninja_in) {
+  std::ostringstream out;
+  int num_blank_lines = 0;
+  for (std::string line; std::getline(build_ninja_in, line);) {
+    out << line << '\n';
+    if (line.empty())
+      ++num_blank_lines;
+    // Warning: Significant magic number. Represents the number of blank lines
+    // in the ninja rules written by NinjaBuildWriter::WriteNinjaRules below.
+    if (num_blank_lines == 4)
+      return out.str();
+  }
+  return std::string{};
+}
+
 void NinjaBuildWriter::WriteNinjaRules() {
   out_ << "ninja_required_version = "
        << build_settings_->ninja_required_version().Describe() << "\n\n";
@@ -295,16 +325,25 @@ void NinjaBuildWriter::WriteNinjaRules() {
   out_ << "  pool = console\n";
   out_ << "  description = Regenerating ninja files\n\n";
 
-  // This rule will regenerate the ninja files when any input file has changed.
-  out_ << "build build.ninja: gn\n"
+  // A comment is left in the build.ninja explaining the two statement setup to
+  // avoid confusion, since build.ninja is written earlier than the ninja rules
+  // might make someone think.
+  out_ << "# The 'gn' rule also writes build.ninja, unbeknownst to ninja. The\n"
+       << "# build.ninja edge is separate to prevent ninja from deleting it\n"
+       << "# (due to depfile usage) if interrupted. gn uses atomic writes to\n"
+       << "# ensure that build.ninja is always valid even if interrupted.\n"
+       << "build build.ninja.stamp: gn\n"
        << "  generator = 1\n"
-       << "  depfile = build.ninja.d\n";
+       << "  depfile = build.ninja.d\n"
+       << "\n"
+       << "build build.ninja: phony build.ninja.stamp\n"
+       << "  generator = 1\n";
 
-  // Input build files. These go in the ".d" file. If we write them as
-  // dependencies in the .ninja file itself, ninja will expect the files to
-  // exist and will error if they don't. When files are listed in a depfile,
-  // missing files are ignored.
-  dep_out_ << "build.ninja:";
+  // Input build files. These go in the ".d" file. If we write them
+  // as dependencies in the .ninja file itself, ninja will expect
+  // the files to exist and will error if they don't. When files are
+  // listed in a depfile, missing files are ignored.
+  dep_out_ << "build.ninja.stamp:";
 
   // Other files read by the build.
   std::vector<base::FilePath> other_files = g_scheduler->GetGenDependencies();
@@ -349,8 +388,10 @@ void NinjaBuildWriter::WriteAllPools() {
   }
 
   for (const Target* target : all_targets_) {
-    if (target->output_type() == Target::ACTION) {
-      const LabelPtrPair<Pool>& pool = target->action_values().pool();
+    if (target->IsBinary() ||
+        target->output_type() == Target::ACTION ||
+        target->output_type() == Target::ACTION_FOREACH) {
+      const LabelPtrPair<Pool>& pool = target->pool();
       if (pool.ptr)
         used_pools.insert(pool.ptr);
     }
@@ -446,6 +487,10 @@ Phony rules
        short name. Use "ninja doom_melon" to compile the
        "//tools/fruit:doom_melon" executable.
 
+       Note that for Apple platforms, create_bundle targets with a product_type
+       of "com.apple.product-type.application" are considered as executable
+       for this rule (as they define application bundles).
+
     5. The short names of all targets if there is only one target with that
        short name.
 
@@ -509,6 +554,13 @@ bool NinjaBuildWriter::WritePhonyAndAllRules(Err* err) {
       exes_counts.last_seen = target;
     }
 
+    if (target->output_type() == Target::CREATE_BUNDLE &&
+        target->bundle_data().is_application()) {
+      Counts& exes_counts = exes[short_name];
+      exes_counts.count++;
+      exes_counts.last_seen = target;
+    }
+
     // Find targets in "important" directories.
     const std::string& dir_string = label.dir().value();
     if (dir_string.size() == 2 && dir_string[0] == '/' &&
diff --git a/gn/src/gn/ninja_build_writer.h b/gn/src/gn/ninja_build_writer.h
index e77f7401c98..c21769a572c 100644
--- a/gn/src/gn/ninja_build_writer.h
+++ b/gn/src/gn/ninja_build_writer.h
@@ -48,9 +48,36 @@ class NinjaBuildWriter {
                               const Builder& builder,
                               Err* err);
 
+  // Extracts from an existing build.ninja file's contents the commands
+  // necessary to run GN and regenerate build.ninja.
+  //
+  // The regeneration rules live at the top of the build.ninja file and their
+  // specific contents are an internal detail of NinjaBuildWriter. Used by
+  // commands::PrepareForRegeneration.
+  //
+  // On error, returns an empty string.
+  static std::string ExtractRegenerationCommands(std::istream& build_ninja_in);
+
   bool Run(Err* err);
 
  private:
+  // WriteNinjaRules writes the rules that ninja uses to regenerate its own
+  // build files, used whenever a build input file has changed.
+  //
+  // Ninja file regeneration is accomplished by two separate build statements.
+  // This is necessary to work around ninja's behavior of deleting all output
+  // files of a build edge if the edge uses a depfile and is interrupted before
+  // it can complete. Previously, interrupting regeneration would cause ninja to
+  // delete build.ninja, losing any flags/build settings passed to gen
+  // previously and requiring the user to manually 'gen' again.
+  //
+  // The workaround involves misleading ninja about when the build.ninja file is
+  // actually written. The first build statement runs the actual 'gen
+  // --regeneration' command, writing "build.ninja" (and .d and .stamp) and
+  // lists the "build.ninja.d" depfile to automatically trigger regeneration as
+  // needed, but does not list "build.ninja" as an output. The second
+  // statement's stated output is "build.ninja", but it simply uses the phony
+  // rule to refer to the first statement.
   void WriteNinjaRules();
   void WriteAllPools();
   bool WriteSubninjas(Err* err);
diff --git a/gn/src/gn/ninja_build_writer_unittest.cc b/gn/src/gn/ninja_build_writer_unittest.cc
index fab082f2af9..ba6af4f0476 100644
--- a/gn/src/gn/ninja_build_writer_unittest.cc
+++ b/gn/src/gn/ninja_build_writer_unittest.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <fstream>
 #include <sstream>
 
 #include "base/command_line.h"
@@ -53,7 +54,7 @@ TEST_F(NinjaBuildWriterTest, GetSelfInvocationCommandLine) {
   // (from //out/Debug to //).
   setup.build_settings()->SetRootPath(root_realpath);
   cmd_out = GetSelfInvocationCommandLine(setup.build_settings());
-  EXPECT_EQ("../..", cmd_out.GetSwitchValueASCII(switches::kRoot));
+  EXPECT_EQ("../..", cmd_out.GetSwitchValueString(switches::kRoot));
   EXPECT_FALSE(cmd_out.HasSwitch(switches::kDotfile));
 
   // If --root is . and --dotfile is foo/.gn, then --dotfile also needs
@@ -61,9 +62,9 @@ TEST_F(NinjaBuildWriterTest, GetSelfInvocationCommandLine) {
   setup.build_settings()->SetRootPath(root_realpath);
   setup.build_settings()->set_dotfile_name(gn_realpath);
   cmd_out = GetSelfInvocationCommandLine(setup.build_settings());
-  EXPECT_EQ("../..", cmd_out.GetSwitchValueASCII(switches::kRoot));
+  EXPECT_EQ("../..", cmd_out.GetSwitchValueString(switches::kRoot));
   EXPECT_EQ("../../testdot.gn",
-            cmd_out.GetSwitchValueASCII(switches::kDotfile));
+            cmd_out.GetSwitchValueString(switches::kDotfile));
 }
 
 TEST_F(NinjaBuildWriterTest, TwoTargets) {
@@ -113,7 +114,7 @@ TEST_F(NinjaBuildWriterTest, TwoTargets) {
   target_baz.action_values().outputs() = SubstitutionList::MakeForTest(
       "//out/Debug/out5.out", "//out/Debug/out6.out");
   target_baz.SetToolchain(&other_toolchain);
-  target_baz.action_values().set_pool(
+  target_baz.set_pool(
       LabelPtrPair<Pool>(&another_regular_pool));
   ASSERT_TRUE(target_baz.OnResolved(&err));
 
@@ -143,10 +144,13 @@ TEST_F(NinjaBuildWriterTest, TwoTargets) {
   ASSERT_TRUE(writer.Run(&err));
 
   const char expected_rule_gn[] = "rule gn\n";
-  const char expected_build_ninja[] =
-      "build build.ninja: gn\n"
+  const char expected_build_ninja_stamp[] =
+      "build build.ninja.stamp: gn\n"
       "  generator = 1\n"
       "  depfile = build.ninja.d\n";
+  const char expected_build_ninja[] =
+      "build build.ninja: phony build.ninja.stamp\n"
+      "  generator = 1\n";
   const char expected_other_pool[] =
       "pool other_toolchain_another_depth_pool\n"
       "  depth = 7\n"
@@ -172,6 +176,7 @@ TEST_F(NinjaBuildWriterTest, TwoTargets) {
       << "Expected to find: " << expected << "\n"      \
       << "Within: " << out_str
   EXPECT_SNIPPET(expected_rule_gn);
+  EXPECT_SNIPPET(expected_build_ninja_stamp);
   EXPECT_SNIPPET(expected_build_ninja);
   EXPECT_SNIPPET(expected_other_pool);
   EXPECT_SNIPPET(expected_toolchain);
@@ -184,6 +189,88 @@ TEST_F(NinjaBuildWriterTest, TwoTargets) {
   EXPECT_EQ(std::string::npos, out_str.find("pool console"));
 }
 
+TEST_F(NinjaBuildWriterTest, ExtractRegenerationCommands) {
+  TestWithScope setup;
+  Err err;
+
+  Target target_foo(setup.settings(), Label(SourceDir("//foo/"), "bar"));
+  target_foo.set_output_type(Target::ACTION);
+  target_foo.action_values().set_script(SourceFile("//foo/script.py"));
+  target_foo.action_values().outputs() = SubstitutionList::MakeForTest(
+      "//out/Debug/out1.out", "//out/Debug/out2.out");
+  target_foo.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target_foo.OnResolved(&err));
+
+  // The console pool must be in the default toolchain.
+  Pool console_pool(setup.settings(), Label(SourceDir("//"), "console",
+                                            setup.toolchain()->label().dir(),
+                                            setup.toolchain()->label().name()));
+  console_pool.set_depth(1);
+
+  std::unordered_map<const Settings*, const Toolchain*> used_toolchains;
+  used_toolchains[setup.settings()] = setup.toolchain();
+
+  std::vector<const Target*> targets = {&target_foo};
+
+  std::stringstream ninja_out;
+  std::ostringstream depfile_out;
+
+  NinjaBuildWriter writer(setup.build_settings(), used_toolchains, targets,
+                          setup.toolchain(), targets, ninja_out, depfile_out);
+  ASSERT_TRUE(writer.Run(&err));
+
+  const char expected_rule_gn[] = "rule gn\n";
+  const char expected_build_ninja_stamp[] = "build build.ninja.stamp: gn\n";
+  const char expected_build_ninja[] =
+      "build build.ninja: phony build.ninja.stamp\n";
+  const char expected_target[] = "build bar:";
+  const char expected_root_target[] = "build all: phony $\n";
+  const char expected_default[] = "default all\n";
+  std::string ninja_out_str = ninja_out.str();
+#define EXPECT_SNIPPET(str, expected)              \
+  EXPECT_NE(std::string::npos, str.find(expected)) \
+      << "Expected to find: " << expected << "\n"  \
+      << "Within: " << str
+#define EXPECT_NO_SNIPPET(str, unexpected)           \
+  EXPECT_EQ(std::string::npos, str.find(unexpected)) \
+      << "Found unexpected: " << unexpected << "\n"  \
+      << "Within: " << str
+  EXPECT_SNIPPET(ninja_out_str, expected_rule_gn);
+  EXPECT_SNIPPET(ninja_out_str, expected_build_ninja_stamp);
+  EXPECT_SNIPPET(ninja_out_str, expected_build_ninja);
+  EXPECT_SNIPPET(ninja_out_str, expected_target);
+  EXPECT_SNIPPET(ninja_out_str, expected_root_target);
+  EXPECT_SNIPPET(ninja_out_str, expected_default);
+
+  std::string commands =
+      NinjaBuildWriter::ExtractRegenerationCommands(ninja_out);
+  EXPECT_SNIPPET(commands, expected_rule_gn);
+  EXPECT_SNIPPET(commands, expected_build_ninja_stamp);
+  EXPECT_SNIPPET(commands, expected_build_ninja);
+  EXPECT_NO_SNIPPET(commands, expected_target);
+  EXPECT_NO_SNIPPET(commands, expected_root_target);
+  EXPECT_NO_SNIPPET(commands, expected_default);
+
+#undef EXPECT_SNIPPET
+#undef EXPECT_NO_SNIPPET
+}
+
+TEST_F(NinjaBuildWriterTest, ExtractRegenerationCommands_DefaultStream) {
+  std::ifstream ninja_in;
+  EXPECT_EQ(NinjaBuildWriter::ExtractRegenerationCommands(ninja_in), "");
+}
+
+TEST_F(NinjaBuildWriterTest, ExtractRegenerationCommands_StreamError) {
+  std::ifstream ninja_in("/does/not/exist");
+  EXPECT_EQ(NinjaBuildWriter::ExtractRegenerationCommands(ninja_in), "");
+}
+
+TEST_F(NinjaBuildWriterTest, ExtractRegenerationCommands_IncompleteNinja) {
+  std::stringstream ninja_in;
+  ninja_in << "foo\nbar\nbaz\nbif\n";
+  EXPECT_EQ(NinjaBuildWriter::ExtractRegenerationCommands(ninja_in), "");
+}
+
 TEST_F(NinjaBuildWriterTest, SpaceInDepfile) {
   TestWithScope setup;
   Err err;
@@ -208,7 +295,7 @@ TEST_F(NinjaBuildWriterTest, SpaceInDepfile) {
   ASSERT_TRUE(writer.Run(&err));
 
   EXPECT_EQ(depfile_out.str(),
-            "build.ninja: ../../path\\ with\\ space/BUILD.gn");
+            "build.ninja.stamp: ../../path\\ with\\ space/BUILD.gn");
 }
 
 TEST_F(NinjaBuildWriterTest, DuplicateOutputs) {
diff --git a/gn/src/gn/ninja_c_binary_target_writer.cc b/gn/src/gn/ninja_c_binary_target_writer.cc
index 5b518b3edd1..1ef0475f910 100644
--- a/gn/src/gn/ninja_c_binary_target_writer.cc
+++ b/gn/src/gn/ninja_c_binary_target_writer.cc
@@ -21,6 +21,7 @@
 #include "gn/general_tool.h"
 #include "gn/ninja_target_command_util.h"
 #include "gn/ninja_utils.h"
+#include "gn/pool.h"
 #include "gn/scheduler.h"
 #include "gn/settings.h"
 #include "gn/string_utils.h"
@@ -224,42 +225,8 @@ void NinjaCBinaryTargetWriter::WriteCompilerVars(
     const std::vector<ModuleDep>& module_dep_info) {
   const SubstitutionBits& subst = target_->toolchain()->substitution_bits();
 
-  // Defines.
-  if (subst.used.count(&CSubstitutionDefines)) {
-    out_ << CSubstitutionDefines.ninja_name << " =";
-    RecursiveTargetConfigToStream<std::string>(kRecursiveWriterSkipDuplicates,
-                                               target_, &ConfigValues::defines,
-                                               DefineWriter(), out_);
-    out_ << std::endl;
-  }
-
-  // Framework search path.
-  if (subst.used.count(&CSubstitutionFrameworkDirs)) {
-    const Tool* tool = target_->toolchain()->GetTool(CTool::kCToolLink);
-
-    out_ << CSubstitutionFrameworkDirs.ninja_name << " =";
-    PathOutput framework_dirs_output(
-        path_output_.current_dir(),
-        settings_->build_settings()->root_path_utf8(), ESCAPE_NINJA_COMMAND);
-    RecursiveTargetConfigToStream<SourceDir>(
-        kRecursiveWriterSkipDuplicates, target_, &ConfigValues::framework_dirs,
-        FrameworkDirsWriter(framework_dirs_output,
-                            tool->framework_dir_switch()),
-        out_);
-    out_ << std::endl;
-  }
-
-  // Include directories.
-  if (subst.used.count(&CSubstitutionIncludeDirs)) {
-    out_ << CSubstitutionIncludeDirs.ninja_name << " =";
-    PathOutput include_path_output(
-        path_output_.current_dir(),
-        settings_->build_settings()->root_path_utf8(), ESCAPE_NINJA_COMMAND);
-    RecursiveTargetConfigToStream<SourceDir>(
-        kRecursiveWriterSkipDuplicates, target_, &ConfigValues::include_dirs,
-        IncludeWriter(include_path_output), out_);
-    out_ << std::endl;
-  }
+  WriteCCompilerVars(subst, /*indent=*/false,
+                     /*respect_source_types_used=*/true);
 
   if (!module_dep_info.empty()) {
     // TODO(scottmg): Currently clang modules only working for C++.
@@ -272,89 +239,6 @@ void NinjaCBinaryTargetWriter::WriteCompilerVars(
     }
   }
 
-  bool has_precompiled_headers =
-      target_->config_values().has_precompiled_headers();
-
-  EscapeOptions opts = GetFlagOptions();
-  if (target_->source_types_used().Get(SourceFile::SOURCE_S) ||
-      target_->source_types_used().Get(SourceFile::SOURCE_ASM)) {
-    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_,
-                 &CSubstitutionAsmFlags, false, Tool::kToolNone,
-                 &ConfigValues::asmflags, opts, path_output_, out_);
-  }
-  if (target_->source_types_used().Get(SourceFile::SOURCE_C) ||
-      target_->source_types_used().Get(SourceFile::SOURCE_CPP) ||
-      target_->source_types_used().Get(SourceFile::SOURCE_M) ||
-      target_->source_types_used().Get(SourceFile::SOURCE_MM) ||
-      target_->source_types_used().Get(SourceFile::SOURCE_MODULEMAP)) {
-    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_, &CSubstitutionCFlags,
-                 false, Tool::kToolNone, &ConfigValues::cflags, opts,
-                 path_output_, out_);
-  }
-  if (target_->source_types_used().Get(SourceFile::SOURCE_C)) {
-    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_, &CSubstitutionCFlagsC,
-                 has_precompiled_headers, CTool::kCToolCc,
-                 &ConfigValues::cflags_c, opts, path_output_, out_);
-  }
-  if (target_->source_types_used().Get(SourceFile::SOURCE_CPP) ||
-      target_->source_types_used().Get(SourceFile::SOURCE_MODULEMAP)) {
-    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_,
-                 &CSubstitutionCFlagsCc, has_precompiled_headers,
-                 CTool::kCToolCxx, &ConfigValues::cflags_cc, opts, path_output_,
-                 out_);
-  }
-  if (target_->source_types_used().Get(SourceFile::SOURCE_M)) {
-    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_,
-                 &CSubstitutionCFlagsObjC, has_precompiled_headers,
-                 CTool::kCToolObjC, &ConfigValues::cflags_objc, opts,
-                 path_output_, out_);
-  }
-  if (target_->source_types_used().Get(SourceFile::SOURCE_MM)) {
-    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_,
-                 &CSubstitutionCFlagsObjCc, has_precompiled_headers,
-                 CTool::kCToolObjCxx, &ConfigValues::cflags_objcc, opts,
-                 path_output_, out_);
-  }
-  if (target_->source_types_used().SwiftSourceUsed()) {
-    if (subst.used.count(&CSubstitutionSwiftModuleName)) {
-      out_ << CSubstitutionSwiftModuleName.ninja_name << " = ";
-      EscapeStringToStream(out_, target_->swift_values().module_name(), opts);
-      out_ << std::endl;
-    }
-
-    if (subst.used.count(&CSubstitutionSwiftBridgeHeader)) {
-      out_ << CSubstitutionSwiftBridgeHeader.ninja_name << " = ";
-      if (!target_->swift_values().bridge_header().is_null()) {
-        path_output_.WriteFile(out_, target_->swift_values().bridge_header());
-      } else {
-        out_ << R"("")";
-      }
-      out_ << std::endl;
-    }
-
-    if (subst.used.count(&CSubstitutionSwiftModuleDirs)) {
-      // Uniquify the list of swiftmodule dirs (in case multiple swiftmodules
-      // are generated in the same directory).
-      UniqueVector<SourceDir> swiftmodule_dirs;
-      for (const Target* dep : target_->swift_values().modules())
-        swiftmodule_dirs.push_back(dep->swift_values().module_output_dir());
-
-      out_ << CSubstitutionSwiftModuleDirs.ninja_name << " =";
-      PathOutput swiftmodule_path_output(
-          path_output_.current_dir(),
-          settings_->build_settings()->root_path_utf8(), ESCAPE_NINJA_COMMAND);
-      IncludeWriter swiftmodule_path_writer(swiftmodule_path_output);
-      for (const SourceDir& swiftmodule_dir : swiftmodule_dirs) {
-        swiftmodule_path_writer(swiftmodule_dir, out_);
-      }
-      out_ << std::endl;
-    }
-
-    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_,
-                 &CSubstitutionSwiftFlags, false, CTool::kCToolSwift,
-                 &ConfigValues::swiftflags, opts, path_output_, out_);
-  }
-
   WriteSharedVars(subst);
 }
 
@@ -601,6 +485,7 @@ void NinjaCBinaryTargetWriter::WriteSources(
 
       WriteCompilerBuildLine({source}, deps, order_only_deps, tool_name,
                              tool_outputs);
+      WritePool(out_);
     }
 
     // It's theoretically possible for a compiler to produce more than one
@@ -681,14 +566,14 @@ void NinjaCBinaryTargetWriter::WriteSwiftSources(
 
     WriteCompilerBuildLine(target_->sources(), input_deps,
                            swift_order_only_deps.vector(), tool->name(),
-                           {swiftmodule_output_file});
+                           {swiftmodule_output_file}, false);
 
     if (!additional_outputs.empty()) {
       out_ << std::endl;
       WriteCompilerBuildLine(
           {swiftmodule_output_file.AsSourceFile(settings_->build_settings())},
           input_deps, swift_order_only_deps.vector(),
-          GeneralTool::kGeneralToolStamp, additional_outputs);
+          GeneralTool::kGeneralToolStamp, additional_outputs, false);
     }
   }
 
@@ -775,11 +660,12 @@ void NinjaCBinaryTargetWriter::WriteLinkerStuff(
   std::copy(input_deps.begin(), input_deps.end(),
             std::back_inserter(implicit_deps));
 
-  // Any C++ target which depends on a Rust .rlib has to depend on its
-  // entire tree of transitive rlibs.
+  // Any C++ target which depends on a Rust .rlib has to depend on its entire
+  // tree of transitive rlibs found inside the linking target (which excludes
+  // rlibs only depended on inside a shared library dependency).
   std::vector<OutputFile> transitive_rustlibs;
   if (target_->IsFinal()) {
-    for (const auto* dep : target_->rust_transitive_libs().GetOrdered()) {
+    for (const auto* dep : target_->inherited_libraries().GetOrdered()) {
       if (dep->output_type() == Target::RUST_LIBRARY) {
         transitive_rustlibs.push_back(dep->dependency_output_file());
         implicit_deps.push_back(dep->dependency_output_file());
@@ -794,7 +680,7 @@ void NinjaCBinaryTargetWriter::WriteLinkerStuff(
       swiftmodules.push_back(dep->swift_values().module_output_file());
       implicit_deps.push_back(dep->swift_values().module_output_file());
     }
-    if (target_->swift_values().builds_module()) {
+    if (target_->builds_swift_module()) {
       swiftmodules.push_back(target_->swift_values().module_output_file());
       implicit_deps.push_back(target_->swift_values().module_output_file());
     }
@@ -850,6 +736,7 @@ void NinjaCBinaryTargetWriter::WriteLinkerStuff(
   WriteOutputSubstitutions();
   WriteLibsList("solibs", solibs);
   WriteLibsList("rlibs", transitive_rustlibs);
+  WritePool(out_);
 }
 
 void NinjaCBinaryTargetWriter::WriteOutputSubstitutions() {
diff --git a/gn/src/gn/ninja_c_binary_target_writer_unittest.cc b/gn/src/gn/ninja_c_binary_target_writer_unittest.cc
index 61bc517f966..38df42b0491 100644
--- a/gn/src/gn/ninja_c_binary_target_writer_unittest.cc
+++ b/gn/src/gn/ninja_c_binary_target_writer_unittest.cc
@@ -10,6 +10,7 @@
 
 #include "gn/config.h"
 #include "gn/ninja_target_command_util.h"
+#include "gn/pool.h"
 #include "gn/scheduler.h"
 #include "gn/target.h"
 #include "gn/test_with_scheduler.h"
@@ -53,7 +54,11 @@ TEST_F(NinjaCBinaryTargetWriterTest, SourceSet) {
         "target_output_name = bar\n"
         "\n"
         "build obj/foo/bar.input1.o: cxx ../../foo/input1.cc\n"
+        "  source_file_part = input1.cc\n"
+        "  source_name_part = input1\n"
         "build obj/foo/bar.input2.o: cxx ../../foo/input2.cc\n"
+        "  source_file_part = input2.cc\n"
+        "  source_name_part = input2\n"
         "\n"
         "build obj/foo/bar.stamp: stamp obj/foo/bar.input1.o "
         "obj/foo/bar.input2.o ../../foo/input3.o ../../foo/input4.obj\n";
@@ -204,6 +209,8 @@ TEST_F(NinjaCBinaryTargetWriterTest, StaticLibrary) {
       "target_output_name = libbar\n"
       "\n"
       "build obj/foo/libbar.input1.o: cxx ../../foo/input1.cc\n"
+      "  source_file_part = input1.cc\n"
+      "  source_name_part = input1\n"
       "\n"
       "build obj/foo/libbar.a: alink obj/foo/libbar.input1.o\n"
       "  arflags = --asdf\n"
@@ -250,6 +257,8 @@ TEST_F(NinjaCBinaryTargetWriterTest, CompleteStaticLibrary) {
         "target_output_name = libbar\n"
         "\n"
         "build obj/foo/libbar.input1.o: cxx ../../foo/input1.cc\n"
+        "  source_file_part = input1.cc\n"
+        "  source_name_part = input1\n"
         "\n"
         "build obj/foo/libbar.a: alink obj/foo/libbar.input1.o "
         "obj/foo/libbaz.input2.o || obj/foo/libbaz.a\n"
@@ -279,6 +288,8 @@ TEST_F(NinjaCBinaryTargetWriterTest, CompleteStaticLibrary) {
         "target_output_name = libbar\n"
         "\n"
         "build obj/foo/libbar.input1.o: cxx ../../foo/input1.cc\n"
+        "  source_file_part = input1.cc\n"
+        "  source_name_part = input1\n"
         "\n"
         "build obj/foo/libbar.a: alink obj/foo/libbar.input1.o "
         "|| obj/foo/libbaz.a\n"
@@ -330,8 +341,12 @@ TEST_F(NinjaCBinaryTargetWriterTest, OutputExtensionAndInputDeps) {
       "\n"
       "build obj/foo/libshlib.input1.o: cxx ../../foo/input1.cc"
       " || obj/foo/action.stamp\n"
+      "  source_file_part = input1.cc\n"
+      "  source_name_part = input1\n"
       "build obj/foo/libshlib.input2.o: cxx ../../foo/input2.cc"
       " || obj/foo/action.stamp\n"
+      "  source_file_part = input2.cc\n"
+      "  source_name_part = input2\n"
       "\n"
       "build ./libshlib.so.6: solink obj/foo/libshlib.input1.o "
       // The order-only dependency here is stricly unnecessary since the
@@ -391,16 +406,18 @@ TEST_F(NinjaCBinaryTargetWriterTest, NoHardDepsToNoPublicHeaderTarget) {
       "target_out_dir = obj/foo\n"
       "target_output_name = gen_obj\n"
       "\n"
-      "build obj/out/Debug/gen_obj.generated.o: cxx generated.cc"
+      "build obj/BUILD_DIR/gen_obj.generated.o: cxx generated.cc"
       " || obj/foo/generate.stamp\n"
+      "  source_file_part = generated.cc\n"
+      "  source_name_part = generated\n"
       "\n"
-      "build obj/foo/gen_obj.stamp: stamp obj/out/Debug/gen_obj.generated.o"
+      "build obj/foo/gen_obj.stamp: stamp obj/BUILD_DIR/gen_obj.generated.o"
       // The order-only dependency here is strictly unnecessary since the
       // sources list this as an order-only dep.
       " || obj/foo/generate.stamp\n";
 
   std::string obj_str = obj_out.str();
-  EXPECT_EQ(obj_expected, obj_str);
+  EXPECT_EQ(std::string(obj_expected), obj_str);
 
   // A shared library depends on gen_obj, having corresponding header for
   // generated obj.
@@ -426,7 +443,7 @@ TEST_F(NinjaCBinaryTargetWriterTest, NoHardDepsToNoPublicHeaderTarget) {
       "target_output_name = libgen_lib\n"
       "\n"
       "\n"
-      "build ./libgen_lib.so: solink obj/out/Debug/gen_obj.generated.o"
+      "build ./libgen_lib.so: solink obj/BUILD_DIR/gen_obj.generated.o"
       // The order-only dependency here is strictly unnecessary since
       // obj/out/Debug/gen_obj.generated.o has dependency to
       // obj/foo/gen_obj.stamp
@@ -467,6 +484,8 @@ TEST_F(NinjaCBinaryTargetWriterTest, NoHardDepsToNoPublicHeaderTarget) {
       "target_output_name = final_target\n"
       "\n"
       "build obj/foo/final_target.main.o: cxx ../../foo/main.cc\n"
+      "  source_file_part = main.cc\n"
+      "  source_name_part = main\n"
       "\n"
       "build ./final_target: link obj/foo/final_target.main.o"
       " ./libgen_lib.so\n"
@@ -613,7 +632,11 @@ TEST_F(NinjaCBinaryTargetWriterTest, EmptyOutputExtension) {
       "target_output_name = shlib\n"
       "\n"
       "build obj/foo/shlib.input1.o: cxx ../../foo/input1.cc\n"
+      "  source_file_part = input1.cc\n"
+      "  source_name_part = input1\n"
       "build obj/foo/shlib.input2.o: cxx ../../foo/input2.cc\n"
+      "  source_file_part = input2.cc\n"
+      "  source_name_part = input2\n"
       "\n"
       "build ./shlib: solink obj/foo/shlib.input1.o "
       "obj/foo/shlib.input2.o\n"
@@ -667,6 +690,8 @@ TEST_F(NinjaCBinaryTargetWriterTest, SourceSetDataDeps) {
       "target_output_name = inter\n"
       "\n"
       "build obj/foo/inter.inter.o: cxx ../../foo/inter.cc\n"
+      "  source_file_part = inter.cc\n"
+      "  source_name_part = inter\n"
       "\n"
       "build obj/foo/inter.stamp: stamp obj/foo/inter.inter.o || "
       "./data_target\n";
@@ -700,6 +725,8 @@ TEST_F(NinjaCBinaryTargetWriterTest, SourceSetDataDeps) {
       "target_output_name = exe\n"
       "\n"
       "build obj/foo/exe.final.o: cxx ../../foo/final.cc\n"
+      "  source_file_part = final.cc\n"
+      "  source_name_part = final\n"
       "\n"
       "build ./exe: link obj/foo/exe.final.o obj/foo/inter.inter.o || "
       "obj/foo/inter.stamp\n"
@@ -739,6 +766,8 @@ TEST_F(NinjaCBinaryTargetWriterTest, SharedLibraryModuleDefinitionFile) {
       "target_output_name = libbar\n"
       "\n"
       "build obj/foo/libbar.sources.o: cxx ../../foo/sources.cc\n"
+      "  source_file_part = sources.cc\n"
+      "  source_name_part = sources\n"
       "\n"
       "build ./libbar.so: solink obj/foo/libbar.sources.o | ../../foo/bar.def\n"
       "  ldflags = /DEF:../../foo/bar.def\n"
@@ -776,6 +805,8 @@ TEST_F(NinjaCBinaryTargetWriterTest, LoadableModule) {
       "target_output_name = libbar\n"
       "\n"
       "build obj/foo/libbar.sources.o: cxx ../../foo/sources.cc\n"
+      "  source_file_part = sources.cc\n"
+      "  source_name_part = sources\n"
       "\n"
       "build ./libbar.so: solink_module obj/foo/libbar.sources.o\n"
       "  ldflags =\n"
@@ -811,6 +842,8 @@ TEST_F(NinjaCBinaryTargetWriterTest, LoadableModule) {
       "target_output_name = exe\n"
       "\n"
       "build obj/foo/exe.final.o: cxx ../../foo/final.cc\n"
+      "  source_file_part = final.cc\n"
+      "  source_name_part = final\n"
       "\n"
       "build ./exe: link obj/foo/exe.final.o || ./libbar.so\n"
       "  ldflags =\n"
@@ -888,8 +921,12 @@ TEST_F(NinjaCBinaryTargetWriterTest, WinPrecompiledHeaders) {
         "\n"
         "build withpch/obj/foo/no_pch_target.input1.o: "
         "withpch_cxx ../../foo/input1.cc\n"
+        "  source_file_part = input1.cc\n"
+        "  source_name_part = input1\n"
         "build withpch/obj/foo/no_pch_target.input2.o: "
         "withpch_cc ../../foo/input2.c\n"
+        "  source_file_part = input2.c\n"
+        "  source_name_part = input2\n"
         "\n"
         "build withpch/obj/foo/no_pch_target.stamp: "
         "withpch_stamp withpch/obj/foo/no_pch_target.input1.o "
@@ -930,20 +967,28 @@ TEST_F(NinjaCBinaryTargetWriterTest, WinPrecompiledHeaders) {
         // Compile the precompiled source files with /Yc.
         "build withpch/obj/build/pch_target.precompile.c.o: "
         "withpch_cc ../../build/precompile.cc\n"
+        "  source_file_part = precompile.cc\n"
+        "  source_name_part = precompile\n"
         "  cflags_c = ${cflags_c} /Ycbuild/precompile.h\n"
         "\n"
         "build withpch/obj/build/pch_target.precompile.cc.o: "
         "withpch_cxx ../../build/precompile.cc\n"
+        "  source_file_part = precompile.cc\n"
+        "  source_name_part = precompile\n"
         "  cflags_cc = ${cflags_cc} /Ycbuild/precompile.h\n"
         "\n"
         "build withpch/obj/foo/pch_target.input1.o: "
         "withpch_cxx ../../foo/input1.cc | "
         // Explicit dependency on the PCH build step.
         "withpch/obj/build/pch_target.precompile.cc.o\n"
+        "  source_file_part = input1.cc\n"
+        "  source_name_part = input1\n"
         "build withpch/obj/foo/pch_target.input2.o: "
         "withpch_cc ../../foo/input2.c | "
         // Explicit dependency on the PCH build step.
         "withpch/obj/build/pch_target.precompile.c.o\n"
+        "  source_file_part = input2.c\n"
+        "  source_name_part = input2\n"
         "\n"
         "build withpch/obj/foo/pch_target.stamp: withpch_stamp "
         "withpch/obj/foo/pch_target.input1.o "
@@ -1022,8 +1067,12 @@ TEST_F(NinjaCBinaryTargetWriterTest, GCCPrecompiledHeaders) {
         "\n"
         "build withpch/obj/foo/no_pch_target.input1.o: "
         "withpch_cxx ../../foo/input1.cc\n"
+        "  source_file_part = input1.cc\n"
+        "  source_name_part = input1\n"
         "build withpch/obj/foo/no_pch_target.input2.o: "
         "withpch_cc ../../foo/input2.c\n"
+        "  source_file_part = input2.c\n"
+        "  source_name_part = input2\n"
         "\n"
         "build withpch/obj/foo/no_pch_target.stamp: "
         "withpch_stamp withpch/obj/foo/no_pch_target.input1.o "
@@ -1062,20 +1111,28 @@ TEST_F(NinjaCBinaryTargetWriterTest, GCCPrecompiledHeaders) {
         // Compile the precompiled sources with -x <lang>.
         "build withpch/obj/build/pch_target.precompile.h-c.gch: "
         "withpch_cc ../../build/precompile.h\n"
+        "  source_file_part = precompile.h\n"
+        "  source_name_part = precompile\n"
         "  cflags_c = -std=c99 -x c-header\n"
         "\n"
         "build withpch/obj/build/pch_target.precompile.h-cc.gch: "
         "withpch_cxx ../../build/precompile.h\n"
+        "  source_file_part = precompile.h\n"
+        "  source_name_part = precompile\n"
         "  cflags_cc = -x c++-header\n"
         "\n"
         "build withpch/obj/foo/pch_target.input1.o: "
         "withpch_cxx ../../foo/input1.cc | "
         // Explicit dependency on the PCH build step.
         "withpch/obj/build/pch_target.precompile.h-cc.gch\n"
+        "  source_file_part = input1.cc\n"
+        "  source_name_part = input1\n"
         "build withpch/obj/foo/pch_target.input2.o: "
         "withpch_cc ../../foo/input2.c | "
         // Explicit dependency on the PCH build step.
         "withpch/obj/build/pch_target.precompile.h-c.gch\n"
+        "  source_file_part = input2.c\n"
+        "  source_name_part = input2\n"
         "\n"
         "build withpch/obj/foo/pch_target.stamp: "
         "withpch_stamp withpch/obj/foo/pch_target.input1.o "
@@ -1140,8 +1197,12 @@ TEST_F(NinjaCBinaryTargetWriterTest, InputFiles) {
         "\n"
         "build obj/foo/bar.input1.o: cxx ../../foo/input1.cc"
         " | ../../foo/input.data\n"
+        "  source_file_part = input1.cc\n"
+        "  source_name_part = input1\n"
         "build obj/foo/bar.input2.o: cxx ../../foo/input2.cc"
         " | ../../foo/input.data\n"
+        "  source_file_part = input2.cc\n"
+        "  source_name_part = input2\n"
         "\n"
         "build obj/foo/bar.stamp: stamp obj/foo/bar.input1.o "
         "obj/foo/bar.input2.o\n";
@@ -1211,8 +1272,12 @@ TEST_F(NinjaCBinaryTargetWriterTest, InputFiles) {
         " ../../foo/input1.data ../../foo/input2.data\n"
         "build obj/foo/bar.input1.o: cxx ../../foo/input1.cc"
         " | obj/foo/bar.inputs.stamp\n"
+        "  source_file_part = input1.cc\n"
+        "  source_name_part = input1\n"
         "build obj/foo/bar.input2.o: cxx ../../foo/input2.cc"
         " | obj/foo/bar.inputs.stamp\n"
+        "  source_file_part = input2.cc\n"
+        "  source_name_part = input2\n"
         "\n"
         "build obj/foo/bar.stamp: stamp obj/foo/bar.input1.o "
         "obj/foo/bar.input2.o\n";
@@ -1261,8 +1326,12 @@ TEST_F(NinjaCBinaryTargetWriterTest, InputFiles) {
         " ../../foo/input1.data ../../foo/input2.data ../../foo/input3.data\n"
         "build obj/foo/bar.input1.o: cxx ../../foo/input1.cc"
         " | obj/foo/bar.inputs.stamp\n"
+        "  source_file_part = input1.cc\n"
+        "  source_name_part = input1\n"
         "build obj/foo/bar.input2.o: cxx ../../foo/input2.cc"
         " | obj/foo/bar.inputs.stamp\n"
+        "  source_file_part = input2.cc\n"
+        "  source_name_part = input2\n"
         "\n"
         "build obj/foo/bar.stamp: stamp obj/foo/bar.input1.o "
         "obj/foo/bar.input2.o\n";
@@ -1272,232 +1341,883 @@ TEST_F(NinjaCBinaryTargetWriterTest, InputFiles) {
 }
 
 // Test linking of Rust dependencies into C targets.
-TEST_F(NinjaCBinaryTargetWriterTest, RustDeps) {
+TEST_F(NinjaCBinaryTargetWriterTest, RustStaticLib) {
   Err err;
   TestWithScope setup;
 
-  {
-    Target library_target(setup.settings(), Label(SourceDir("//foo/"), "foo"));
-    library_target.set_output_type(Target::STATIC_LIBRARY);
-    library_target.visibility().SetPublic();
-    SourceFile lib("//foo/lib.rs");
-    library_target.sources().push_back(lib);
-    library_target.source_types_used().Set(SourceFile::SOURCE_RS);
-    library_target.rust_values().set_crate_root(lib);
-    library_target.rust_values().crate_name() = "foo";
-    library_target.SetToolchain(setup.toolchain());
-    ASSERT_TRUE(library_target.OnResolved(&err));
-
-    Target target(setup.settings(), Label(SourceDir("//bar/"), "bar"));
-    target.set_output_type(Target::EXECUTABLE);
-    target.visibility().SetPublic();
-    target.sources().push_back(SourceFile("//bar/bar.cc"));
-    target.source_types_used().Set(SourceFile::SOURCE_CPP);
-    target.private_deps().push_back(LabelTargetPair(&library_target));
-    target.SetToolchain(setup.toolchain());
-    ASSERT_TRUE(target.OnResolved(&err));
+  Target library_target(setup.settings(), Label(SourceDir("//foo/"), "foo"));
+  library_target.set_output_type(Target::STATIC_LIBRARY);
+  library_target.visibility().SetPublic();
+  SourceFile lib("//foo/lib.rs");
+  library_target.sources().push_back(lib);
+  library_target.source_types_used().Set(SourceFile::SOURCE_RS);
+  library_target.rust_values().set_crate_root(lib);
+  library_target.rust_values().crate_name() = "foo";
+  library_target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(library_target.OnResolved(&err));
+
+  Target target(setup.settings(), Label(SourceDir("//bar/"), "bar"));
+  target.set_output_type(Target::EXECUTABLE);
+  target.visibility().SetPublic();
+  target.sources().push_back(SourceFile("//bar/bar.cc"));
+  target.source_types_used().Set(SourceFile::SOURCE_CPP);
+  target.private_deps().push_back(LabelTargetPair(&library_target));
+  target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target.OnResolved(&err));
 
-    std::ostringstream out;
-    NinjaCBinaryTargetWriter writer(&target, out);
-    writer.Run();
+  std::ostringstream out;
+  NinjaCBinaryTargetWriter writer(&target, out);
+  writer.Run();
 
-    const char expected[] =
-        "defines =\n"
-        "include_dirs =\n"
-        "cflags =\n"
-        "cflags_cc =\n"
-        "root_out_dir = .\n"
-        "target_out_dir = obj/bar\n"
-        "target_output_name = bar\n"
-        "\n"
-        "build obj/bar/bar.bar.o: cxx ../../bar/bar.cc\n"
-        "\n"
-        "build ./bar: link obj/bar/bar.bar.o obj/foo/libfoo.a\n"
-        "  ldflags =\n"
-        "  libs =\n"
-        "  frameworks =\n"
-        "  swiftmodules =\n"
-        "  output_extension = \n"
-        "  output_dir = \n";
+  const char expected[] =
+      "defines =\n"
+      "include_dirs =\n"
+      "cflags =\n"
+      "cflags_cc =\n"
+      "root_out_dir = .\n"
+      "target_out_dir = obj/bar\n"
+      "target_output_name = bar\n"
+      "\n"
+      "build obj/bar/bar.bar.o: cxx ../../bar/bar.cc\n"
+      "  source_file_part = bar.cc\n"
+      "  source_name_part = bar\n"
+      "\n"
+      "build ./bar: link obj/bar/bar.bar.o obj/foo/libfoo.a\n"
+      "  ldflags =\n"
+      "  libs =\n"
+      "  frameworks =\n"
+      "  swiftmodules =\n"
+      "  output_extension = \n"
+      "  output_dir = \n";
 
-    std::string out_str = out.str();
-    EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
-  }
+  std::string out_str = out.str();
+  EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+}
 
-  {
-    Target rlib_target(setup.settings(), Label(SourceDir("//baz/"), "lib"));
-    rlib_target.set_output_type(Target::RUST_LIBRARY);
-    rlib_target.visibility().SetPublic();
-    SourceFile bazlib("//baz/lib.rs");
-    rlib_target.sources().push_back(bazlib);
-    rlib_target.source_types_used().Set(SourceFile::SOURCE_RS);
-    rlib_target.rust_values().set_crate_root(bazlib);
-    rlib_target.rust_values().crate_name() = "lib";
-    rlib_target.SetToolchain(setup.toolchain());
-    ASSERT_TRUE(rlib_target.OnResolved(&err));
-
-    Target library_target(setup.settings(), Label(SourceDir("//foo/"), "foo"));
-    library_target.set_output_type(Target::STATIC_LIBRARY);
-    library_target.visibility().SetPublic();
-    SourceFile lib("//foo/lib.rs");
-    library_target.sources().push_back(lib);
-    library_target.source_types_used().Set(SourceFile::SOURCE_RS);
-    library_target.rust_values().set_crate_root(lib);
-    library_target.rust_values().crate_name() = "foo";
-    library_target.public_deps().push_back(LabelTargetPair(&rlib_target));
-    library_target.SetToolchain(setup.toolchain());
-    ASSERT_TRUE(library_target.OnResolved(&err));
-
-    Target rlib_target2(setup.settings(), Label(SourceDir("//qux/"), "lib2"));
-    rlib_target2.set_output_type(Target::RUST_LIBRARY);
-    rlib_target2.visibility().SetPublic();
-    SourceFile quxlib("//qux/lib.rs");
-    rlib_target2.sources().push_back(quxlib);
-    rlib_target2.source_types_used().Set(SourceFile::SOURCE_RS);
-    rlib_target2.rust_values().set_crate_root(quxlib);
-    rlib_target2.rust_values().crate_name() = "lib2";
-    rlib_target2.SetToolchain(setup.toolchain());
-    ASSERT_TRUE(rlib_target2.OnResolved(&err));
-
-    Target rlib_target3(setup.settings(), Label(SourceDir("//quxqux/"), "lib3"));
-    rlib_target3.set_output_type(Target::RUST_LIBRARY);
-    rlib_target3.visibility().SetPublic();
-    SourceFile quxquxlib("//quxqux/lib.rs");
-    rlib_target3.sources().push_back(quxquxlib);
-    rlib_target3.source_types_used().Set(SourceFile::SOURCE_RS);
-    rlib_target3.rust_values().set_crate_root(quxlib);
-    rlib_target3.rust_values().crate_name() = "lib3";
-    rlib_target3.SetToolchain(setup.toolchain());
-    ASSERT_TRUE(rlib_target3.OnResolved(&err));
-
-    Target procmacro(setup.settings(),
-                     Label(SourceDir("//quuxmacro/"), "procmacro"));
-    procmacro.set_output_type(Target::RUST_PROC_MACRO);
-    procmacro.visibility().SetPublic();
-    SourceFile procmacrolib("//procmacro/lib.rs");
-    procmacro.sources().push_back(procmacrolib);
-    procmacro.source_types_used().Set(SourceFile::SOURCE_RS);
-    procmacro.public_deps().push_back(LabelTargetPair(&rlib_target2));
-    procmacro.public_deps().push_back(LabelTargetPair(&rlib_target3));
-    procmacro.rust_values().set_crate_root(procmacrolib);
-    procmacro.rust_values().crate_name() = "procmacro";
-    procmacro.SetToolchain(setup.toolchain());
-    ASSERT_TRUE(procmacro.OnResolved(&err));
-
-    Target rlib_target4(setup.settings(), Label(SourceDir("//quux/"), "lib4"));
-    rlib_target4.set_output_type(Target::RUST_LIBRARY);
-    rlib_target4.visibility().SetPublic();
-    SourceFile quuxlib("//quux/lib.rs");
-    rlib_target4.sources().push_back(quuxlib);
-    rlib_target4.source_types_used().Set(SourceFile::SOURCE_RS);
-    rlib_target4.public_deps().push_back(LabelTargetPair(&rlib_target2));
-    // Transitive proc macros should not impact C++ targets; we're
-    // adding one to ensure the ninja instructions below are unaffected.
-    rlib_target4.public_deps().push_back(LabelTargetPair(&procmacro));
-    rlib_target4.rust_values().set_crate_root(quuxlib);
-    rlib_target4.rust_values().crate_name() = "lib4";
-    rlib_target4.SetToolchain(setup.toolchain());
-    ASSERT_TRUE(rlib_target4.OnResolved(&err));
-
-    Target target(setup.settings(), Label(SourceDir("//bar/"), "bar"));
-    target.set_output_type(Target::EXECUTABLE);
-    target.visibility().SetPublic();
-    target.sources().push_back(SourceFile("//bar/bar.cc"));
-    target.source_types_used().Set(SourceFile::SOURCE_CPP);
-    target.private_deps().push_back(LabelTargetPair(&library_target));
-    target.private_deps().push_back(LabelTargetPair(&rlib_target4));
-    target.SetToolchain(setup.toolchain());
-    ASSERT_TRUE(target.OnResolved(&err));
+// Test linking of Rust dependencies into C targets.
+TEST_F(NinjaCBinaryTargetWriterTest, RlibInLibrary) {
+  Err err;
+  TestWithScope setup;
 
-    std::ostringstream out;
-    NinjaCBinaryTargetWriter writer(&target, out);
-    writer.Run();
+  // This source_set() is depended on by an rlib, which is a private dep of a
+  // static lib.
+  Target priv_sset_in_staticlib(
+      setup.settings(),
+      Label(SourceDir("//priv_sset_in_staticlib/"), "priv_sset_in_staticlib"));
+  priv_sset_in_staticlib.set_output_type(Target::SOURCE_SET);
+  priv_sset_in_staticlib.visibility().SetPublic();
+  priv_sset_in_staticlib.sources().push_back(
+      SourceFile("//priv_sset_in_staticlib/lib.cc"));
+  priv_sset_in_staticlib.source_types_used().Set(SourceFile::SOURCE_CPP);
+  priv_sset_in_staticlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(priv_sset_in_staticlib.OnResolved(&err));
+
+  // This source_set() is depended on by an rlib, which is a public dep of a
+  // static lib.
+  Target pub_sset_in_staticlib(
+      setup.settings(),
+      Label(SourceDir("//pub_sset_in_staticlib/"), "pub_sset_in_staticlib"));
+  pub_sset_in_staticlib.set_output_type(Target::SOURCE_SET);
+  pub_sset_in_staticlib.visibility().SetPublic();
+  pub_sset_in_staticlib.sources().push_back(
+      SourceFile("//pub_sset_in_staticlib/lib.cc"));
+  pub_sset_in_staticlib.source_types_used().Set(SourceFile::SOURCE_CPP);
+  pub_sset_in_staticlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(pub_sset_in_staticlib.OnResolved(&err));
+
+  // This source_set() is depended on by an rlib, which is a private dep of a
+  // shared lib.
+  Target priv_sset_in_dylib(
+      setup.settings(),
+      Label(SourceDir("//priv_sset_in_dylib/"), "priv_sset_in_dylib"));
+  priv_sset_in_dylib.set_output_type(Target::SOURCE_SET);
+  priv_sset_in_dylib.visibility().SetPublic();
+  priv_sset_in_dylib.sources().push_back(
+      SourceFile("//priv_sset_in_dylib/lib.cc"));
+  priv_sset_in_dylib.source_types_used().Set(SourceFile::SOURCE_CPP);
+  priv_sset_in_dylib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(priv_sset_in_dylib.OnResolved(&err));
+
+  // This source_set() is depended on by an rlib, which is a public dep of a
+  // shared lib.
+  Target pub_sset_in_dylib(
+      setup.settings(),
+      Label(SourceDir("//pub_sset_in_dylib"), "pub_sset_in_dylib"));
+  pub_sset_in_dylib.set_output_type(Target::SOURCE_SET);
+  pub_sset_in_dylib.visibility().SetPublic();
+  pub_sset_in_dylib.sources().push_back(
+      SourceFile("//pub_sset_in_dylib/lib.cc"));
+  pub_sset_in_dylib.source_types_used().Set(SourceFile::SOURCE_CPP);
+  pub_sset_in_dylib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(pub_sset_in_dylib.OnResolved(&err));
+
+  Target priv_in_staticlib(
+      setup.settings(),
+      Label(SourceDir("//priv_in_staticlib/"), "priv_in_staticlib"));
+  priv_in_staticlib.set_output_type(Target::RUST_LIBRARY);
+  priv_in_staticlib.visibility().SetPublic();
+  SourceFile priv_in_staticlib_root("//priv_in_staticlib/lib.rs");
+  priv_in_staticlib.sources().push_back(priv_in_staticlib_root);
+  priv_in_staticlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  priv_in_staticlib.rust_values().set_crate_root(priv_in_staticlib_root);
+  priv_in_staticlib.rust_values().crate_name() = "priv_in_staticlib";
+  priv_in_staticlib.SetToolchain(setup.toolchain());
+  priv_in_staticlib.private_deps().push_back(
+      LabelTargetPair(&priv_sset_in_staticlib));
+  ASSERT_TRUE(priv_in_staticlib.OnResolved(&err));
+
+  Target pub_in_staticlib(
+      setup.settings(),
+      Label(SourceDir("//pub_in_staticlib/"), "pub_in_staticlib"));
+  pub_in_staticlib.set_output_type(Target::RUST_LIBRARY);
+  pub_in_staticlib.visibility().SetPublic();
+  SourceFile pub_in_staticlib_root("//pub_in_staticlib/lib.rs");
+  pub_in_staticlib.sources().push_back(pub_in_staticlib_root);
+  pub_in_staticlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  pub_in_staticlib.rust_values().set_crate_root(pub_in_staticlib_root);
+  pub_in_staticlib.rust_values().crate_name() = "pub_in_staticlib";
+  pub_in_staticlib.SetToolchain(setup.toolchain());
+  pub_in_staticlib.private_deps().push_back(
+      LabelTargetPair(&pub_sset_in_staticlib));
+  ASSERT_TRUE(pub_in_staticlib.OnResolved(&err));
+
+  Target priv_in_dylib(setup.settings(),
+                       Label(SourceDir("//priv_in_dylib/"), "priv_in_dylib"));
+  priv_in_dylib.set_output_type(Target::RUST_LIBRARY);
+  priv_in_dylib.visibility().SetPublic();
+  SourceFile priv_in_dylib_root("//priv_in_dylib/lib.rs");
+  priv_in_dylib.sources().push_back(priv_in_dylib_root);
+  priv_in_dylib.source_types_used().Set(SourceFile::SOURCE_RS);
+  priv_in_dylib.rust_values().set_crate_root(priv_in_dylib_root);
+  priv_in_dylib.rust_values().crate_name() = "priv_in_dylib";
+  priv_in_dylib.SetToolchain(setup.toolchain());
+  priv_in_dylib.private_deps().push_back(LabelTargetPair(&priv_sset_in_dylib));
+  ASSERT_TRUE(priv_in_dylib.OnResolved(&err));
+
+  Target pub_in_dylib(setup.settings(),
+                      Label(SourceDir("//pub_in_dylib/"), "pub_in_dylib"));
+  pub_in_dylib.set_output_type(Target::RUST_LIBRARY);
+  pub_in_dylib.visibility().SetPublic();
+  SourceFile pub_in_dylib_root("//pub_in_dylib/lib.rs");
+  pub_in_dylib.sources().push_back(pub_in_dylib_root);
+  pub_in_dylib.source_types_used().Set(SourceFile::SOURCE_RS);
+  pub_in_dylib.rust_values().set_crate_root(pub_in_dylib_root);
+  pub_in_dylib.rust_values().crate_name() = "pub_in_dylib";
+  pub_in_dylib.SetToolchain(setup.toolchain());
+  pub_in_dylib.private_deps().push_back(LabelTargetPair(&pub_sset_in_dylib));
+  ASSERT_TRUE(pub_in_dylib.OnResolved(&err));
+
+  Target staticlib(setup.settings(),
+                   Label(SourceDir("//staticlib/"), "staticlib"));
+  staticlib.set_output_type(Target::STATIC_LIBRARY);
+  staticlib.visibility().SetPublic();
+  staticlib.sources().push_back(SourceFile("//staticlib/lib.cc"));
+  staticlib.source_types_used().Set(SourceFile::SOURCE_CPP);
+  staticlib.public_deps().push_back(LabelTargetPair(&pub_in_staticlib));
+  staticlib.private_deps().push_back(LabelTargetPair(&priv_in_staticlib));
+  staticlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(staticlib.OnResolved(&err));
+
+  Target dylib(setup.settings(), Label(SourceDir("//dylib/"), "dylib"));
+  dylib.set_output_type(Target::SHARED_LIBRARY);
+  dylib.visibility().SetPublic();
+  SourceFile dylib_root("//dylib/lib.rs");
+  dylib.sources().push_back(dylib_root);
+  dylib.source_types_used().Set(SourceFile::SOURCE_RS);
+  dylib.rust_values().set_crate_root(dylib_root);
+  dylib.rust_values().crate_name() = "dylib";
+  dylib.public_deps().push_back(LabelTargetPair(&pub_in_dylib));
+  dylib.private_deps().push_back(LabelTargetPair(&priv_in_dylib));
+  dylib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(dylib.OnResolved(&err));
+
+  Target target(setup.settings(), Label(SourceDir("//exe/"), "exe"));
+  target.set_output_type(Target::EXECUTABLE);
+  target.visibility().SetPublic();
+  target.sources().push_back(SourceFile("//exe/main.cc"));
+  target.source_types_used().Set(SourceFile::SOURCE_CPP);
+  target.private_deps().push_back(LabelTargetPair(&staticlib));
+  target.private_deps().push_back(LabelTargetPair(&dylib));
+  target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target.OnResolved(&err));
 
-    const char expected[] =
-        "defines =\n"
-        "include_dirs =\n"
-        "cflags =\n"
-        "cflags_cc =\n"
-        "root_out_dir = .\n"
-        "target_out_dir = obj/bar\n"
-        "target_output_name = bar\n"
-        "\n"
-        "build obj/bar/bar.bar.o: cxx ../../bar/bar.cc\n"
-        "\n"
-        "build ./bar: link obj/bar/bar.bar.o obj/foo/libfoo.a | "
-        "obj/baz/lib.rlib obj/quux/lib4.rlib obj/qux/lib2.rlib\n"
-        "  ldflags =\n"
-        "  libs =\n"
-        "  frameworks =\n"
-        "  swiftmodules =\n"
-        "  output_extension = \n"
-        "  output_dir = \n"
-        "  rlibs = obj/baz/lib.rlib obj/quux/lib4.rlib obj/qux/lib2.rlib\n";
 
-    std::string out_str = out.str();
-    EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
-  }
+  std::ostringstream out;
+  NinjaCBinaryTargetWriter writer(&target, out);
+  writer.Run();
 
-  {
-    Target procmacro(setup.settings(), Label(SourceDir("//baz/"), "macro"));
-    procmacro.set_output_type(Target::LOADABLE_MODULE);
-    procmacro.visibility().SetPublic();
-    SourceFile bazlib("//baz/lib.rs");
-    procmacro.sources().push_back(bazlib);
-    procmacro.source_types_used().Set(SourceFile::SOURCE_RS);
-    procmacro.rust_values().set_crate_root(bazlib);
-    procmacro.rust_values().crate_name() = "macro";
-    procmacro.rust_values().set_crate_type(RustValues::CRATE_PROC_MACRO);
-    procmacro.SetToolchain(setup.toolchain());
-    ASSERT_TRUE(procmacro.OnResolved(&err));
-
-    Target library_target(setup.settings(), Label(SourceDir("//foo/"), "foo"));
-    library_target.set_output_type(Target::STATIC_LIBRARY);
-    library_target.visibility().SetPublic();
-    SourceFile lib("//foo/lib.rs");
-    library_target.sources().push_back(lib);
-    library_target.source_types_used().Set(SourceFile::SOURCE_RS);
-    library_target.rust_values().set_crate_root(lib);
-    library_target.rust_values().crate_name() = "foo";
-    library_target.public_deps().push_back(LabelTargetPair(&procmacro));
-    library_target.SetToolchain(setup.toolchain());
-    ASSERT_TRUE(library_target.OnResolved(&err));
-
-    Target target(setup.settings(), Label(SourceDir("//bar/"), "bar"));
-    target.set_output_type(Target::EXECUTABLE);
-    target.visibility().SetPublic();
-    target.sources().push_back(SourceFile("//bar/bar.cc"));
-    target.source_types_used().Set(SourceFile::SOURCE_CPP);
-    target.private_deps().push_back(LabelTargetPair(&library_target));
-    target.SetToolchain(setup.toolchain());
-    ASSERT_TRUE(target.OnResolved(&err));
+  const char expected[] =
+      "defines =\n"
+      "include_dirs =\n"
+      "cflags =\n"
+      "cflags_cc =\n"
+      "root_out_dir = .\n"
+      "target_out_dir = obj/exe\n"
+      "target_output_name = exe\n"
+      "\n"
+      "build obj/exe/exe.main.o: cxx ../../exe/main.cc\n"
+      "  source_file_part = main.cc\n"
+      "  source_name_part = main\n"
+      "\n"
+      "build ./exe: link obj/exe/exe.main.o "
+      "obj/pub_sset_in_staticlib/pub_sset_in_staticlib.lib.o "
+      "obj/priv_sset_in_staticlib/priv_sset_in_staticlib.lib.o "
+      "obj/staticlib/libstaticlib.a "
+      "obj/dylib/libdylib.so | "
+      "obj/pub_in_staticlib/libpub_in_staticlib.rlib "
+      "obj/priv_in_staticlib/libpriv_in_staticlib.rlib || "
+      "obj/pub_sset_in_staticlib/pub_sset_in_staticlib.stamp "
+      "obj/priv_sset_in_staticlib/priv_sset_in_staticlib.stamp\n"
+      "  ldflags =\n"
+      "  libs =\n"
+      "  frameworks =\n"
+      "  swiftmodules =\n"
+      "  output_extension = \n"
+      "  output_dir = \n"
+      "  rlibs = obj/pub_in_staticlib/libpub_in_staticlib.rlib "
+      "obj/priv_in_staticlib/libpriv_in_staticlib.rlib\n";
 
-    std::ostringstream out;
-    NinjaCBinaryTargetWriter writer(&target, out);
-    writer.Run();
+  std::string out_str = out.str();
+  EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+}
 
-    const char expected[] =
-        "defines =\n"
-        "include_dirs =\n"
-        "cflags =\n"
-        "cflags_cc =\n"
-        "root_out_dir = .\n"
-        "target_out_dir = obj/bar\n"
-        "target_output_name = bar\n"
-        "\n"
-        "build obj/bar/bar.bar.o: cxx ../../bar/bar.cc\n"
-        "\n"
-        "build ./bar: link obj/bar/bar.bar.o obj/foo/libfoo.a\n"
-        "  ldflags =\n"
-        "  libs =\n"
-        "  frameworks =\n"
-        "  swiftmodules =\n"
-        "  output_extension = \n"
-        "  output_dir = \n";
+// Test linking of Rust dependencies into C targets. Proc-macro dependencies are
+// not inherited by the targets that depend on them, even from public_deps,
+// since they are not built into those targets, but instead used to build them.
+TEST_F(NinjaCBinaryTargetWriterTest, RlibsWithProcMacros) {
+  Err err;
+  TestWithScope setup;
 
-    std::string out_str = out.str();
-    EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
-  }
+  Target pub_in_staticlib(
+      setup.settings(),
+      Label(SourceDir("//pub_in_staticlib/"), "pub_in_staticlib"));
+  pub_in_staticlib.set_output_type(Target::RUST_LIBRARY);
+  pub_in_staticlib.visibility().SetPublic();
+  SourceFile pub_in_staticlib_root("//pub_in_staticlib/lib.rs");
+  pub_in_staticlib.sources().push_back(pub_in_staticlib_root);
+  pub_in_staticlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  pub_in_staticlib.rust_values().set_crate_root(pub_in_staticlib_root);
+  pub_in_staticlib.rust_values().crate_name() = "pub_in_staticlib";
+  pub_in_staticlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(pub_in_staticlib.OnResolved(&err));
+
+  Target priv_in_staticlib(
+      setup.settings(),
+      Label(SourceDir("//priv_in_staticlib/"), "priv_in_staticlib"));
+  priv_in_staticlib.set_output_type(Target::RUST_LIBRARY);
+  priv_in_staticlib.visibility().SetPublic();
+  SourceFile priv_in_staticlib_root("//priv_in_staticlib/lib.rs");
+  priv_in_staticlib.sources().push_back(priv_in_staticlib_root);
+  priv_in_staticlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  priv_in_staticlib.rust_values().set_crate_root(priv_in_staticlib_root);
+  priv_in_staticlib.rust_values().crate_name() = "priv_in_staticlib";
+  priv_in_staticlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(priv_in_staticlib.OnResolved(&err));
+
+  Target staticlib(setup.settings(),
+                   Label(SourceDir("//staticlib/"), "staticlib"));
+  staticlib.set_output_type(Target::STATIC_LIBRARY);
+  staticlib.visibility().SetPublic();
+  staticlib.sources().push_back(SourceFile("//staticlib/lib.cc"));
+  staticlib.source_types_used().Set(SourceFile::SOURCE_CPP);
+  staticlib.public_deps().push_back(LabelTargetPair(&pub_in_staticlib));
+  staticlib.private_deps().push_back(LabelTargetPair(&priv_in_staticlib));
+  staticlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(staticlib.OnResolved(&err));
+
+  Target priv_in_procmacro(
+      setup.settings(),
+      Label(SourceDir("//priv_in_procmacro/"), "priv_in_procmacro"));
+  priv_in_procmacro.set_output_type(Target::RUST_LIBRARY);
+  priv_in_procmacro.visibility().SetPublic();
+  SourceFile priv_in_procmacro_root("//priv_in_procmacro/lib.rs");
+  priv_in_procmacro.sources().push_back(priv_in_procmacro_root);
+  priv_in_procmacro.source_types_used().Set(SourceFile::SOURCE_RS);
+  priv_in_procmacro.rust_values().set_crate_root(priv_in_procmacro_root);
+  priv_in_procmacro.rust_values().crate_name() = "priv_in_procmacro";
+  priv_in_procmacro.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(priv_in_procmacro.OnResolved(&err));
+
+  // Public deps in a proc-macro are not inherited, since the proc-macro is not
+  // compiled into targets that depend on it.
+  Target pub_in_procmacro(
+      setup.settings(),
+      Label(SourceDir("//pub_in_procmacro/"), "pub_in_procmacro"));
+  pub_in_procmacro.set_output_type(Target::RUST_LIBRARY);
+  pub_in_procmacro.visibility().SetPublic();
+  SourceFile pub_in_procmacro_root("//pub_in_procmacro/lib.rs");
+  pub_in_procmacro.sources().push_back(pub_in_procmacro_root);
+  pub_in_procmacro.source_types_used().Set(SourceFile::SOURCE_RS);
+  pub_in_procmacro.rust_values().set_crate_root(pub_in_procmacro_root);
+  pub_in_procmacro.rust_values().crate_name() = "pub_in_procmacro";
+  pub_in_procmacro.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(pub_in_procmacro.OnResolved(&err));
+
+  Target pub_in_procmacro_and_rlib(
+      setup.settings(), Label(SourceDir("//pub_in_procmacro_and_rlib/"),
+                              "pub_in_procmacro_and_rlib"));
+  pub_in_procmacro_and_rlib.set_output_type(Target::RUST_LIBRARY);
+  pub_in_procmacro_and_rlib.visibility().SetPublic();
+  SourceFile pub_in_procmacro_and_rlib_root(
+      "//pub_in_procmacro_and_rlib/lib.rs");
+  pub_in_procmacro_and_rlib.sources().push_back(pub_in_procmacro_and_rlib_root);
+  pub_in_procmacro_and_rlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  pub_in_procmacro_and_rlib.rust_values().set_crate_root(
+      pub_in_procmacro_and_rlib_root);
+  pub_in_procmacro_and_rlib.rust_values().crate_name() = "lib2";
+  pub_in_procmacro_and_rlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(pub_in_procmacro_and_rlib.OnResolved(&err));
+
+  Target procmacro(setup.settings(),
+                   Label(SourceDir("//procmacro/"), "procmacro"));
+  procmacro.set_output_type(Target::RUST_PROC_MACRO);
+  procmacro.visibility().SetPublic();
+  SourceFile procmacrolib("//procmacro/lib.rs");
+  procmacro.sources().push_back(procmacrolib);
+  procmacro.source_types_used().Set(SourceFile::SOURCE_RS);
+  procmacro.public_deps().push_back(LabelTargetPair(&pub_in_procmacro));
+  procmacro.public_deps().push_back(LabelTargetPair(&priv_in_procmacro));
+  procmacro.public_deps().push_back(
+      LabelTargetPair(&pub_in_procmacro_and_rlib));
+  procmacro.rust_values().set_crate_root(procmacrolib);
+  procmacro.rust_values().crate_name() = "procmacro";
+  procmacro.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(procmacro.OnResolved(&err));
+
+  Target rlib(setup.settings(), Label(SourceDir("//rlib/"), "rlib"));
+  rlib.set_output_type(Target::RUST_LIBRARY);
+  rlib.visibility().SetPublic();
+  SourceFile rlib_root("//rlib/lib.rs");
+  rlib.sources().push_back(rlib_root);
+  rlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  rlib.public_deps().push_back(LabelTargetPair(&pub_in_procmacro_and_rlib));
+  // Transitive proc macros should not impact C++ targets; we're
+  // adding one to ensure the ninja instructions below are unaffected.
+  rlib.public_deps().push_back(LabelTargetPair(&procmacro));
+  rlib.rust_values().set_crate_root(rlib_root);
+  rlib.rust_values().crate_name() = "rlib";
+  rlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(rlib.OnResolved(&err));
+
+  Target target(setup.settings(), Label(SourceDir("//exe/"), "exe"));
+  target.set_output_type(Target::EXECUTABLE);
+  target.visibility().SetPublic();
+  target.sources().push_back(SourceFile("//exe/main.cc"));
+  target.source_types_used().Set(SourceFile::SOURCE_CPP);
+  target.private_deps().push_back(LabelTargetPair(&staticlib));
+  target.private_deps().push_back(LabelTargetPair(&rlib));
+  target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target.OnResolved(&err));
+
+  std::ostringstream out;
+  NinjaCBinaryTargetWriter writer(&target, out);
+  writer.Run();
+
+  const char expected[] =
+      "defines =\n"
+      "include_dirs =\n"
+      "cflags =\n"
+      "cflags_cc =\n"
+      "root_out_dir = .\n"
+      "target_out_dir = obj/exe\n"
+      "target_output_name = exe\n"
+      "\n"
+      "build obj/exe/exe.main.o: cxx ../../exe/main.cc\n"
+      "  source_file_part = main.cc\n"
+      "  source_name_part = main\n"
+      "\n"
+      "build ./exe: link obj/exe/exe.main.o "
+      "obj/staticlib/libstaticlib.a | "
+      "obj/pub_in_staticlib/libpub_in_staticlib.rlib "
+      "obj/priv_in_staticlib/libpriv_in_staticlib.rlib "
+      "obj/rlib/librlib.rlib "
+      "obj/pub_in_procmacro_and_rlib/libpub_in_procmacro_and_rlib.rlib\n"
+      "  ldflags =\n"
+      "  libs =\n"
+      "  frameworks =\n"
+      "  swiftmodules =\n"
+      "  output_extension = \n"
+      "  output_dir = \n"
+      "  rlibs = obj/pub_in_staticlib/libpub_in_staticlib.rlib "
+      "obj/priv_in_staticlib/libpriv_in_staticlib.rlib "
+      "obj/rlib/librlib.rlib "
+      "obj/pub_in_procmacro_and_rlib/libpub_in_procmacro_and_rlib.rlib\n";
+
+  std::string out_str = out.str();
+  EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+}
+
+// Test linking of Rust dependencies into C targets.
+TEST_F(NinjaCBinaryTargetWriterTest, ProcMacroInRustStaticLib) {
+  Err err;
+  TestWithScope setup;
+
+  Target procmacro(setup.settings(), Label(SourceDir("//baz/"), "macro"));
+  procmacro.set_output_type(Target::LOADABLE_MODULE);
+  procmacro.visibility().SetPublic();
+  SourceFile bazlib("//baz/lib.rs");
+  procmacro.sources().push_back(bazlib);
+  procmacro.source_types_used().Set(SourceFile::SOURCE_RS);
+  procmacro.rust_values().set_crate_root(bazlib);
+  procmacro.rust_values().crate_name() = "macro";
+  procmacro.rust_values().set_crate_type(RustValues::CRATE_PROC_MACRO);
+  procmacro.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(procmacro.OnResolved(&err));
+
+  Target library_target(setup.settings(), Label(SourceDir("//foo/"), "foo"));
+  library_target.set_output_type(Target::STATIC_LIBRARY);
+  library_target.visibility().SetPublic();
+  SourceFile lib("//foo/lib.rs");
+  library_target.sources().push_back(lib);
+  library_target.source_types_used().Set(SourceFile::SOURCE_RS);
+  library_target.rust_values().set_crate_root(lib);
+  library_target.rust_values().crate_name() = "foo";
+  library_target.public_deps().push_back(LabelTargetPair(&procmacro));
+  library_target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(library_target.OnResolved(&err));
+
+  Target target(setup.settings(), Label(SourceDir("//bar/"), "bar"));
+  target.set_output_type(Target::EXECUTABLE);
+  target.visibility().SetPublic();
+  target.sources().push_back(SourceFile("//bar/bar.cc"));
+  target.source_types_used().Set(SourceFile::SOURCE_CPP);
+  target.private_deps().push_back(LabelTargetPair(&library_target));
+  target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target.OnResolved(&err));
+
+  std::ostringstream out;
+  NinjaCBinaryTargetWriter writer(&target, out);
+  writer.Run();
+
+  const char expected[] =
+      "defines =\n"
+      "include_dirs =\n"
+      "cflags =\n"
+      "cflags_cc =\n"
+      "root_out_dir = .\n"
+      "target_out_dir = obj/bar\n"
+      "target_output_name = bar\n"
+      "\n"
+      "build obj/bar/bar.bar.o: cxx ../../bar/bar.cc\n"
+      "  source_file_part = bar.cc\n"
+      "  source_name_part = bar\n"
+      "\n"
+      "build ./bar: link obj/bar/bar.bar.o obj/foo/libfoo.a\n"
+      "  ldflags =\n"
+      "  libs =\n"
+      "  frameworks =\n"
+      "  swiftmodules =\n"
+      "  output_extension = \n"
+      "  output_dir = \n";
+
+  std::string out_str = out.str();
+  EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+}
+
+TEST_F(NinjaCBinaryTargetWriterTest, RustDepsOverDynamicLinking) {
+  Err err;
+  TestWithScope setup;
+
+  Target rlib3(setup.settings(), Label(SourceDir("//baz/"), "baz"));
+  rlib3.set_output_type(Target::RUST_LIBRARY);
+  rlib3.visibility().SetPublic();
+  SourceFile lib3("//baz/lib.rs");
+  rlib3.sources().push_back(lib3);
+  rlib3.source_types_used().Set(SourceFile::SOURCE_RS);
+  rlib3.rust_values().set_crate_root(lib3);
+  rlib3.rust_values().crate_name() = "baz";
+  rlib3.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(rlib3.OnResolved(&err));
+
+  Target rlib2(setup.settings(), Label(SourceDir("//bar/"), "bar"));
+  rlib2.set_output_type(Target::RUST_LIBRARY);
+  rlib2.visibility().SetPublic();
+  SourceFile lib2("//bar/lib.rs");
+  rlib2.sources().push_back(lib2);
+  rlib2.source_types_used().Set(SourceFile::SOURCE_RS);
+  rlib2.rust_values().set_crate_root(lib2);
+  rlib2.rust_values().crate_name() = "bar";
+  rlib2.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(rlib2.OnResolved(&err));
+
+  Target rlib(setup.settings(), Label(SourceDir("//foo/"), "foo"));
+  rlib.set_output_type(Target::RUST_LIBRARY);
+  rlib.visibility().SetPublic();
+  SourceFile lib("//foo/lib.rs");
+  rlib.sources().push_back(lib);
+  rlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  rlib.rust_values().set_crate_root(lib);
+  rlib.rust_values().crate_name() = "foo";
+  rlib.public_deps().push_back(LabelTargetPair(&rlib2));
+  rlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(rlib.OnResolved(&err));
+
+  Target cdylib(setup.settings(), Label(SourceDir("//sh/"), "mylib"));
+  cdylib.set_output_type(Target::SHARED_LIBRARY);
+  cdylib.visibility().SetPublic();
+  SourceFile barlib("//sh/lib.rs");
+  cdylib.sources().push_back(barlib);
+  cdylib.source_types_used().Set(SourceFile::SOURCE_RS);
+  cdylib.rust_values().set_crate_type(RustValues::CRATE_CDYLIB);
+  cdylib.rust_values().set_crate_root(barlib);
+  cdylib.rust_values().crate_name() = "mylib";
+  cdylib.private_deps().push_back(LabelTargetPair(&rlib));
+  cdylib.public_deps().push_back(LabelTargetPair(&rlib3));
+  cdylib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(cdylib.OnResolved(&err));
+
+  Target nearrlib(setup.settings(), Label(SourceDir("//near/"), "near"));
+  nearrlib.set_output_type(Target::RUST_LIBRARY);
+  nearrlib.visibility().SetPublic();
+  SourceFile nearlib("//near/lib.rs");
+  nearrlib.sources().push_back(nearlib);
+  nearrlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  nearrlib.rust_values().set_crate_root(nearlib);
+  nearrlib.rust_values().crate_name() = "near";
+  nearrlib.public_deps().push_back(LabelTargetPair(&cdylib));
+  nearrlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(nearrlib.OnResolved(&err));
+
+  Target target(setup.settings(), Label(SourceDir("//exe/"), "binary"));
+  target.set_output_type(Target::EXECUTABLE);
+  target.visibility().SetPublic();
+  target.sources().push_back(SourceFile("//exe/main.cc"));
+  target.source_types_used().Set(SourceFile::SOURCE_CPP);
+  target.private_deps().push_back(LabelTargetPair(&nearrlib));
+  target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target.OnResolved(&err));
+
+  std::ostringstream out;
+  NinjaCBinaryTargetWriter writer(&target, out);
+  writer.Run();
+
+  const char expected[] =
+      "defines =\n"
+      "include_dirs =\n"
+      "cflags =\n"
+      "cflags_cc =\n"
+      "root_out_dir = .\n"
+      "target_out_dir = obj/exe\n"
+      "target_output_name = binary\n"
+      "\n"
+      "build obj/exe/binary.main.o: cxx ../../exe/main.cc\n"
+      "  source_file_part = main.cc\n"
+      "  source_name_part = main\n"
+      "\n"
+      "build ./binary: link obj/exe/binary.main.o obj/sh/libmylib.so | "
+      "obj/near/libnear.rlib\n"
+      "  ldflags =\n"
+      "  libs =\n"
+      "  frameworks =\n"
+      "  swiftmodules =\n"
+      "  output_extension = \n"
+      "  output_dir = \n"
+      "  rlibs = obj/near/libnear.rlib\n";
+
+  std::string out_str = out.str();
+  EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+}
+
+TEST_F(NinjaCBinaryTargetWriterTest, LinkingWithRustLibraryDepsOnCdylib) {
+  Err err;
+  TestWithScope setup;
+
+  // A non-rust shared library.
+  Target cc_shlib(setup.settings(), Label(SourceDir("//cc_shlib"), "cc_shlib"));
+  cc_shlib.set_output_type(Target::SHARED_LIBRARY);
+  cc_shlib.set_output_name("cc_shlib");
+  cc_shlib.SetToolchain(setup.toolchain());
+  cc_shlib.visibility().SetPublic();
+  ASSERT_TRUE(cc_shlib.OnResolved(&err));
+
+  // A Rust CDYLIB shared library that will be in deps.
+  Target rust_shlib(setup.settings(),
+                    Label(SourceDir("//rust_shlib/"), "rust_shlib"));
+  rust_shlib.set_output_type(Target::SHARED_LIBRARY);
+  rust_shlib.visibility().SetPublic();
+  SourceFile rust_shlib_rs("//rust_shlib/lib.rs");
+  rust_shlib.sources().push_back(rust_shlib_rs);
+  rust_shlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  rust_shlib.rust_values().set_crate_type(RustValues::CRATE_CDYLIB);
+  rust_shlib.rust_values().set_crate_root(rust_shlib_rs);
+  rust_shlib.rust_values().crate_name() = "rust_shlib";
+  rust_shlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(rust_shlib.OnResolved(&err));
+
+  // A Rust DYLIB shared library that will be in public_deps.
+  Target pub_rust_shlib(setup.settings(), Label(SourceDir("//pub_rust_shlib/"),
+                                                "pub_rust_shlib"));
+  pub_rust_shlib.set_output_type(Target::SHARED_LIBRARY);
+  pub_rust_shlib.visibility().SetPublic();
+  SourceFile pub_rust_shlib_rs("//pub_rust_shlib/lib.rs");
+  pub_rust_shlib.sources().push_back(pub_rust_shlib_rs);
+  pub_rust_shlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  pub_rust_shlib.rust_values().set_crate_type(RustValues::CRATE_CDYLIB);
+  pub_rust_shlib.rust_values().set_crate_root(pub_rust_shlib_rs);
+  pub_rust_shlib.rust_values().crate_name() = "pub_rust_shlib";
+  pub_rust_shlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(pub_rust_shlib.OnResolved(&err));
+
+  // An rlib that depends on both shared libraries.
+  Target rlib(setup.settings(), Label(SourceDir("//rlib/"), "rlib"));
+  rlib.set_output_type(Target::RUST_LIBRARY);
+  rlib.visibility().SetPublic();
+  SourceFile rlib_rs("//rlib/lib.rs");
+  rlib.sources().push_back(rlib_rs);
+  rlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  rlib.rust_values().set_crate_root(rlib_rs);
+  rlib.rust_values().crate_name() = "rlib";
+  rlib.private_deps().push_back(LabelTargetPair(&rust_shlib));
+  rlib.private_deps().push_back(LabelTargetPair(&cc_shlib));
+  rlib.public_deps().push_back(LabelTargetPair(&pub_rust_shlib));
+  rlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(rlib.OnResolved(&err));
+
+  Target target(setup.settings(), Label(SourceDir("//exe/"), "binary"));
+  target.set_output_type(Target::EXECUTABLE);
+  target.visibility().SetPublic();
+  target.sources().push_back(SourceFile("//exe/main.cc"));
+  target.source_types_used().Set(SourceFile::SOURCE_CPP);
+  target.private_deps().push_back(LabelTargetPair(&rlib));
+  target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target.OnResolved(&err));
+
+  std::ostringstream out;
+  NinjaCBinaryTargetWriter writer(&target, out);
+  writer.Run();
+
+  const char expected[] =
+      "defines =\n"
+      "include_dirs =\n"
+      "cflags =\n"
+      "cflags_cc =\n"
+      "root_out_dir = .\n"
+      "target_out_dir = obj/exe\n"
+      "target_output_name = binary\n"
+      "\n"
+      "build obj/exe/binary.main.o: cxx ../../exe/main.cc\n"
+      "  source_file_part = main.cc\n"
+      "  source_name_part = main\n"
+      "\n"
+      "build ./binary: link obj/exe/binary.main.o "
+      "obj/pub_rust_shlib/libpub_rust_shlib.so obj/rust_shlib/librust_shlib.so "
+      "./libcc_shlib.so | "
+      "obj/rlib/librlib.rlib\n"
+      "  ldflags =\n"
+      "  libs =\n"
+      "  frameworks =\n"
+      "  swiftmodules =\n"
+      "  output_extension = \n"
+      "  output_dir = \n"
+      "  rlibs = obj/rlib/librlib.rlib\n";
+
+  std::string out_str = out.str();
+  EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+}
+
+TEST_F(NinjaCBinaryTargetWriterTest, LinkingWithRustLibraryDepsOnDylib) {
+  Err err;
+  TestWithScope setup;
+
+  // A non-rust shared library.
+  Target cc_shlib(setup.settings(), Label(SourceDir("//cc_shlib"), "cc_shlib"));
+  cc_shlib.set_output_type(Target::SHARED_LIBRARY);
+  cc_shlib.set_output_name("cc_shlib");
+  cc_shlib.SetToolchain(setup.toolchain());
+  cc_shlib.visibility().SetPublic();
+  ASSERT_TRUE(cc_shlib.OnResolved(&err));
+
+  // A Rust DYLIB shared library that will be in deps.
+  Target rust_shlib(setup.settings(),
+                    Label(SourceDir("//rust_shlib/"), "rust_shlib"));
+  rust_shlib.set_output_type(Target::SHARED_LIBRARY);
+  rust_shlib.visibility().SetPublic();
+  SourceFile rust_shlib_rs("//rust_shlib/lib.rs");
+  rust_shlib.sources().push_back(rust_shlib_rs);
+  rust_shlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  rust_shlib.rust_values().set_crate_type(RustValues::CRATE_DYLIB);
+  rust_shlib.rust_values().set_crate_root(rust_shlib_rs);
+  rust_shlib.rust_values().crate_name() = "rust_shlib";
+  rust_shlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(rust_shlib.OnResolved(&err));
+
+  // A Rust DYLIB shared library that will be in public_deps.
+  Target pub_rust_shlib(setup.settings(), Label(SourceDir("//pub_rust_shlib/"),
+                                                "pub_rust_shlib"));
+  pub_rust_shlib.set_output_type(Target::SHARED_LIBRARY);
+  pub_rust_shlib.visibility().SetPublic();
+  SourceFile pub_rust_shlib_rs("//pub_rust_shlib/lib.rs");
+  pub_rust_shlib.sources().push_back(pub_rust_shlib_rs);
+  pub_rust_shlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  pub_rust_shlib.rust_values().set_crate_type(RustValues::CRATE_DYLIB);
+  pub_rust_shlib.rust_values().set_crate_root(pub_rust_shlib_rs);
+  pub_rust_shlib.rust_values().crate_name() = "pub_rust_shlib";
+  pub_rust_shlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(pub_rust_shlib.OnResolved(&err));
+
+  // An rlib that depends on both shared libraries.
+  Target rlib(setup.settings(), Label(SourceDir("//rlib/"), "rlib"));
+  rlib.set_output_type(Target::RUST_LIBRARY);
+  rlib.visibility().SetPublic();
+  SourceFile rlib_rs("//rlib/lib.rs");
+  rlib.sources().push_back(rlib_rs);
+  rlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  rlib.rust_values().set_crate_root(rlib_rs);
+  rlib.rust_values().crate_name() = "rlib";
+  rlib.private_deps().push_back(LabelTargetPair(&rust_shlib));
+  rlib.private_deps().push_back(LabelTargetPair(&cc_shlib));
+  rlib.public_deps().push_back(LabelTargetPair(&pub_rust_shlib));
+  rlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(rlib.OnResolved(&err));
+
+  Target target(setup.settings(), Label(SourceDir("//exe/"), "binary"));
+  target.set_output_type(Target::EXECUTABLE);
+  target.visibility().SetPublic();
+  target.sources().push_back(SourceFile("//exe/main.cc"));
+  target.source_types_used().Set(SourceFile::SOURCE_CPP);
+  target.private_deps().push_back(LabelTargetPair(&rlib));
+  target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target.OnResolved(&err));
+
+  std::ostringstream out;
+  NinjaCBinaryTargetWriter writer(&target, out);
+  writer.Run();
+
+  const char expected[] =
+      "defines =\n"
+      "include_dirs =\n"
+      "cflags =\n"
+      "cflags_cc =\n"
+      "root_out_dir = .\n"
+      "target_out_dir = obj/exe\n"
+      "target_output_name = binary\n"
+      "\n"
+      "build obj/exe/binary.main.o: cxx ../../exe/main.cc\n"
+      "  source_file_part = main.cc\n"
+      "  source_name_part = main\n"
+      "\n"
+      "build ./binary: link obj/exe/binary.main.o "
+      "obj/pub_rust_shlib/libpub_rust_shlib.so obj/rust_shlib/librust_shlib.so "
+      "./libcc_shlib.so | "
+      "obj/rlib/librlib.rlib\n"
+      "  ldflags =\n"
+      "  libs =\n"
+      "  frameworks =\n"
+      "  swiftmodules =\n"
+      "  output_extension = \n"
+      "  output_dir = \n"
+      "  rlibs = obj/rlib/librlib.rlib\n";
+
+  std::string out_str = out.str();
+  EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+}
+
+// Verify dependencies of a shared library and a rust library are inherited
+// independently.
+TEST_F(NinjaCBinaryTargetWriterTest, RustLibAfterSharedLib) {
+  Err err;
+  TestWithScope setup;
+
+  Target static1(setup.settings(),
+                Label(SourceDir("//static1/"), "staticlib1"));
+  static1.set_output_type(Target::STATIC_LIBRARY);
+  static1.visibility().SetPublic();
+  static1.sources().push_back(SourceFile("//static1/c.cc"));
+  static1.source_types_used().Set(SourceFile::SOURCE_CPP);
+  static1.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(static1.OnResolved(&err));
+
+  Target static2(setup.settings(),
+                Label(SourceDir("//static2/"), "staticlib2"));
+  static2.set_output_type(Target::STATIC_LIBRARY);
+  static2.visibility().SetPublic();
+  static2.sources().push_back(SourceFile("//static2/c.cc"));
+  static2.source_types_used().Set(SourceFile::SOURCE_CPP);
+  static2.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(static2.OnResolved(&err));
+
+  Target static3(setup.settings(),
+                Label(SourceDir("//static3/"), "staticlib3"));
+  static3.set_output_type(Target::STATIC_LIBRARY);
+  static3.visibility().SetPublic();
+  static3.sources().push_back(SourceFile("//static3/c.cc"));
+  static3.source_types_used().Set(SourceFile::SOURCE_CPP);
+  static3.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(static3.OnResolved(&err));
+
+  Target shared1(setup.settings(),
+                    Label(SourceDir("//shared1"), "mysharedlib1"));
+  shared1.set_output_type(Target::SHARED_LIBRARY);
+  shared1.set_output_name("mysharedlib1");
+  shared1.set_output_prefix_override("");
+  shared1.SetToolchain(setup.toolchain());
+  shared1.visibility().SetPublic();
+  shared1.private_deps().push_back(LabelTargetPair(&static1));
+  ASSERT_TRUE(shared1.OnResolved(&err));
+
+  Target rlib2(setup.settings(), Label(SourceDir("//rlib2/"), "myrlib2"));
+  rlib2.set_output_type(Target::RUST_LIBRARY);
+  rlib2.visibility().SetPublic();
+  SourceFile lib2("//rlib2/lib.rs");
+  rlib2.sources().push_back(lib2);
+  rlib2.source_types_used().Set(SourceFile::SOURCE_RS);
+  rlib2.rust_values().set_crate_root(lib2);
+  rlib2.rust_values().crate_name() = "foo";
+  rlib2.private_deps().push_back(LabelTargetPair(&static2));
+  rlib2.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(rlib2.OnResolved(&err));
+
+  Target shared3(setup.settings(),
+                    Label(SourceDir("//shared3"), "mysharedlib3"));
+  shared3.set_output_type(Target::SHARED_LIBRARY);
+  shared3.set_output_name("mysharedlib3");
+  shared3.set_output_prefix_override("");
+  shared3.SetToolchain(setup.toolchain());
+  shared3.visibility().SetPublic();
+  shared3.private_deps().push_back(LabelTargetPair(&static3));
+  ASSERT_TRUE(shared3.OnResolved(&err));
+
+  Target target(setup.settings(), Label(SourceDir("//exe/"), "binary"));
+  target.set_output_type(Target::EXECUTABLE);
+  target.visibility().SetPublic();
+  target.sources().push_back(SourceFile("//exe/main.cc"));
+  target.source_types_used().Set(SourceFile::SOURCE_CPP);
+  target.private_deps().push_back(LabelTargetPair(&shared1));
+  target.private_deps().push_back(LabelTargetPair(&rlib2));
+  target.private_deps().push_back(LabelTargetPair(&shared3));
+  target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target.OnResolved(&err));
+
+  std::ostringstream out;
+  NinjaCBinaryTargetWriter writer(&target, out);
+  writer.Run();
+
+  const char expected[] =
+      "defines =\n"
+      "include_dirs =\n"
+      "cflags =\n"
+      "cflags_cc =\n"
+      "root_out_dir = .\n"
+      "target_out_dir = obj/exe\n"
+      "target_output_name = binary\n"
+      "\n"
+      "build obj/exe/binary.main.o: cxx ../../exe/main.cc\n"
+      "  source_file_part = main.cc\n"
+      "  source_name_part = main\n"
+      "\n"
+      "build ./binary: link obj/exe/binary.main.o "
+      "./mysharedlib1.so ./mysharedlib3.so "
+      "obj/static2/libstaticlib2.a | obj/rlib2/libmyrlib2.rlib\n"
+      "  ldflags =\n"
+      "  libs =\n"
+      "  frameworks =\n"
+      "  swiftmodules =\n"
+      "  output_extension = \n"
+      "  output_dir = \n"
+      "  rlibs = obj/rlib2/libmyrlib2.rlib\n";
+
+  std::string out_str = out.str();
+  EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
 }
 
 TEST_F(NinjaCBinaryTargetWriterTest, ModuleMapInStaticLibrary) {
@@ -1531,7 +2251,11 @@ TEST_F(NinjaCBinaryTargetWriterTest, ModuleMapInStaticLibrary) {
       "target_output_name = libbar\n"
       "\n"
       "build obj/foo/libbar.bar.o: cxx ../../foo/bar.cc | obj/foo/libbar.bar.pcm\n"
+      "  source_file_part = bar.cc\n"
+      "  source_name_part = bar\n"
       "build obj/foo/libbar.bar.pcm: cxx_module ../../foo/bar.modulemap\n"
+      "  source_file_part = bar.modulemap\n"
+      "  source_name_part = bar\n"
       "\n"
       "build obj/foo/libbar.a: alink obj/foo/libbar.bar.o\n"
       "  arflags =\n"
@@ -1655,10 +2379,10 @@ TEST_F(NinjaCBinaryTargetWriterTest, SwiftModule) {
         "target_output_name = bar\n"
         "\n"
         "build obj/bar/Bar.swiftmodule: swift ../../bar/bar.swift"
-        " || obj/foo/foo.stamp\n"
+        " || obj/bar/group.stamp obj/foo/foo.stamp\n"
         "\n"
         "build obj/bar/bar.o: stamp obj/bar/Bar.swiftmodule"
-        " || obj/foo/foo.stamp\n"
+        " || obj/bar/group.stamp obj/foo/foo.stamp\n"
         "\n"
         "build obj/bar/bar.stamp: stamp obj/bar/bar.o "
         "|| obj/bar/group.stamp obj/foo/foo.stamp\n";
@@ -1780,17 +2504,21 @@ TEST_F(NinjaCBinaryTargetWriterTest, DependOnModule) {
 
     const char expected[] = R"(defines =
 include_dirs =
-module_deps = -Xclang -fmodules-embed-all-files -fmodule-file=obj/blah/liba.a.pcm
-module_deps_no_self = -Xclang -fmodules-embed-all-files
 cflags =
 cflags_cc =
+module_deps = -Xclang -fmodules-embed-all-files -fmodule-file=obj/blah/liba.a.pcm
+module_deps_no_self = -Xclang -fmodules-embed-all-files
 label = //blah$:a
 root_out_dir = withmodules
 target_out_dir = obj/blah
 target_output_name = liba
 
 build obj/blah/liba.a.pcm: cxx_module ../../blah/a.modulemap
+  source_file_part = a.modulemap
+  source_name_part = a
 build obj/blah/liba.a.o: cxx ../../blah/a.cc | obj/blah/liba.a.pcm
+  source_file_part = a.cc
+  source_name_part = a
 
 build obj/blah/liba.a: alink obj/blah/liba.a.o
   arflags =
@@ -1821,17 +2549,21 @@ build obj/blah/liba.a: alink obj/blah/liba.a.o
 
     const char expected[] = R"(defines =
 include_dirs =
-module_deps = -Xclang -fmodules-embed-all-files -fmodule-file=obj/stuff/libb.b.pcm
-module_deps_no_self = -Xclang -fmodules-embed-all-files
 cflags =
 cflags_cc =
+module_deps = -Xclang -fmodules-embed-all-files -fmodule-file=obj/stuff/libb.b.pcm
+module_deps_no_self = -Xclang -fmodules-embed-all-files
 label = //stuff$:b
 root_out_dir = withmodules
 target_out_dir = obj/stuff
 target_output_name = libb
 
 build obj/stuff/libb.b.pcm: cxx_module ../../stuff/b.modulemap
+  source_file_part = b.modulemap
+  source_name_part = b
 build obj/stuff/libb.b.o: cxx ../../stuff/b.cc | obj/stuff/libb.b.pcm
+  source_file_part = b.cc
+  source_name_part = b
 
 build obj/stuff/libb.a: alink obj/stuff/libb.b.o
   arflags =
@@ -1861,16 +2593,18 @@ build obj/stuff/libb.a: alink obj/stuff/libb.b.o
 
     const char expected[] = R"(defines =
 include_dirs =
-module_deps = -Xclang -fmodules-embed-all-files -fmodule-file=obj/stuff/libc.c.pcm -fmodule-file=obj/blah/liba.a.pcm
-module_deps_no_self = -Xclang -fmodules-embed-all-files -fmodule-file=obj/blah/liba.a.pcm
 cflags =
 cflags_cc =
+module_deps = -Xclang -fmodules-embed-all-files -fmodule-file=obj/stuff/libc.c.pcm -fmodule-file=obj/blah/liba.a.pcm
+module_deps_no_self = -Xclang -fmodules-embed-all-files -fmodule-file=obj/blah/liba.a.pcm
 label = //things$:c
 root_out_dir = withmodules
 target_out_dir = obj/things
 target_output_name = libc
 
 build obj/stuff/libc.c.pcm: cxx_module ../../stuff/c.modulemap | obj/blah/liba.a.pcm
+  source_file_part = c.modulemap
+  source_name_part = c
 
 build obj/things/libc.a: alink || obj/blah/liba.a
   arflags =
@@ -1900,17 +2634,21 @@ build obj/things/libc.a: alink || obj/blah/liba.a
 
     const char expected[] = R"(defines =
 include_dirs =
-module_deps = -Xclang -fmodules-embed-all-files -fmodule-file=obj/blah/liba.a.pcm -fmodule-file=obj/stuff/libb.b.pcm
-module_deps_no_self = -Xclang -fmodules-embed-all-files -fmodule-file=obj/blah/liba.a.pcm -fmodule-file=obj/stuff/libb.b.pcm
 cflags =
 cflags_cc =
+module_deps = -Xclang -fmodules-embed-all-files -fmodule-file=obj/blah/liba.a.pcm -fmodule-file=obj/stuff/libb.b.pcm
+module_deps_no_self = -Xclang -fmodules-embed-all-files -fmodule-file=obj/blah/liba.a.pcm -fmodule-file=obj/stuff/libb.b.pcm
 label = //zap$:c
 root_out_dir = withmodules
 target_out_dir = obj/zap
 target_output_name = c
 
 build obj/zap/c.x.o: cxx ../../zap/x.cc | obj/blah/liba.a.pcm obj/stuff/libb.b.pcm
+  source_file_part = x.cc
+  source_name_part = x
 build obj/zap/c.y.o: cxx ../../zap/y.cc | obj/blah/liba.a.pcm obj/stuff/libb.b.pcm
+  source_file_part = y.cc
+  source_name_part = y
 
 build withmodules/c: link obj/zap/c.x.o obj/zap/c.y.o obj/blah/liba.a obj/stuff/libb.a
   ldflags =
@@ -1963,6 +2701,8 @@ target_out_dir = obj/launchpad
 target_output_name = main
 
 build obj/launchpad/main.main.o: cxx ../../launchpad/main.cc
+  source_file_part = main.cc
+  source_name_part = main
 
 build ./main: link obj/launchpad/main.main.o | ./Space$ Cadet.so.TOC
   ldflags =
@@ -1981,3 +2721,48 @@ build ./main: link obj/launchpad/main.main.o | ./Space$ Cadet.so.TOC
   std::string out_str = out.str();
   EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
 }
+
+TEST_F(NinjaCBinaryTargetWriterTest, Pool) {
+  Err err;
+  TestWithScope setup;
+
+  Pool pool(setup.settings(),
+            Label(SourceDir("//foo/"), "pool", setup.toolchain()->label().dir(),
+                  setup.toolchain()->label().name()));
+  pool.set_depth(42);
+
+  Target target(setup.settings(), Label(SourceDir("//foo/"), "bar"));
+  target.sources().push_back(SourceFile("//foo/source.cc"));
+  target.set_output_type(Target::EXECUTABLE);
+  target.set_pool(LabelPtrPair<Pool>(&pool));
+  target.visibility().SetPublic();
+  target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target.OnResolved(&err));
+
+  std::ostringstream out;
+  NinjaBinaryTargetWriter writer(&target, out);
+  writer.Run();
+
+  const char expected[] =
+      "defines =\n"
+      "include_dirs =\n"
+      "root_out_dir = .\n"
+      "target_out_dir = obj/foo\n"
+      "target_output_name = bar\n"
+      "\n"
+      "build obj/foo/bar.source.o: cxx ../../foo/source.cc\n"
+      "  source_file_part = source.cc\n"
+      "  source_name_part = source\n"
+      "  pool = foo_pool\n"
+      "\n"
+      "build ./bar: link obj/foo/bar.source.o\n"
+      "  ldflags =\n"
+      "  libs =\n"
+      "  frameworks =\n"
+      "  swiftmodules =\n"
+      "  output_extension = \n"
+      "  output_dir = \n"
+      "  pool = foo_pool\n";
+  std::string out_str = out.str();
+  EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+}
diff --git a/gn/src/gn/ninja_rust_binary_target_writer.cc b/gn/src/gn/ninja_rust_binary_target_writer.cc
index d894681608d..6b9c2dcf785 100644
--- a/gn/src/gn/ninja_rust_binary_target_writer.cc
+++ b/gn/src/gn/ninja_rust_binary_target_writer.cc
@@ -13,8 +13,8 @@
 #include "gn/ninja_target_command_util.h"
 #include "gn/ninja_utils.h"
 #include "gn/rust_substitution_type.h"
-#include "gn/substitution_writer.h"
 #include "gn/rust_values.h"
+#include "gn/substitution_writer.h"
 #include "gn/target.h"
 
 namespace {
@@ -113,8 +113,8 @@ void NinjaRustBinaryTargetWriter::Run() {
 
   size_t num_stamp_uses = target_->sources().size();
 
-  std::vector<OutputFile> input_deps = WriteInputsStampAndGetDep(
-      num_stamp_uses);
+  std::vector<OutputFile> input_deps =
+      WriteInputsStampAndGetDep(num_stamp_uses);
 
   WriteCompilerVars();
 
@@ -176,11 +176,23 @@ void NinjaRustBinaryTargetWriter::Run() {
     }
   }
 
-  // Bubble up the full list of transitive rlib dependencies.
-  std::vector<OutputFile> transitive_rustlibs;
-  for (const auto* dep : target_->rust_transitive_libs().GetOrdered()) {
-    if (dep->source_types_used().RustSourceUsed()) {
-      transitive_rustlibs.push_back(dep->dependency_output_file());
+  // Collect the full transitive set of rust libraries that this target depends
+  // on, and the public flag represents if the target has direct access to the
+  // dependency through a chain of public_deps.
+  std::vector<ExternCrate> transitive_crates;
+  for (const auto& [dep, has_direct_access] :
+       target_->rust_transitive_inherited_libs().GetOrderedAndPublicFlag()) {
+    // We will tell rustc to look for crate metadata for any rust crate
+    // dependencies except cdylibs, as they have no metadata present.
+    if (dep->source_types_used().RustSourceUsed() &&
+        RustValues::IsRustLibrary(dep)) {
+      transitive_crates.push_back({dep, has_direct_access});
+      // If the current crate can directly acccess the `dep` crate, then the
+      // current crate needs an implicit dependency on `dep` so it will be
+      // rebuilt if `dep` changes.
+      if (has_direct_access) {
+        implicit_deps.push_back(dep->dependency_output_file());
+      }
     }
   }
 
@@ -196,9 +208,9 @@ void NinjaRustBinaryTargetWriter::Run() {
   std::copy(classified_deps.non_linkable_deps.begin(),
             classified_deps.non_linkable_deps.end(),
             std::back_inserter(extern_deps));
-  WriteExterns(extern_deps);
-  WriteRustdeps(transitive_rustlibs, rustdeps, nonrustdeps);
+  WriteExternsAndDeps(extern_deps, transitive_crates, rustdeps, nonrustdeps);
   WriteSourcesAndInputs();
+  WritePool(out_);
 }
 
 void NinjaRustBinaryTargetWriter::WriteCompilerVars() {
@@ -207,13 +219,7 @@ void NinjaRustBinaryTargetWriter::WriteCompilerVars() {
   EscapeOptions opts = GetFlagOptions();
   WriteCrateVars(target_, tool_, opts, out_);
 
-  WriteOneFlag(kRecursiveWriterKeepDuplicates, target_,
-               &kRustSubstitutionRustFlags, false, Tool::kToolNone,
-               &ConfigValues::rustflags, opts, path_output_, out_);
-
-  WriteOneFlag(kRecursiveWriterKeepDuplicates, target_,
-               &kRustSubstitutionRustEnv, false, Tool::kToolNone,
-               &ConfigValues::rustenv, opts, path_output_, out_);
+  WriteRustCompilerVars(subst, /*indent=*/false, /*always_write=*/true);
 
   WriteSharedVars(subst);
 }
@@ -237,7 +243,8 @@ void NinjaRustBinaryTargetWriter::WriteSourcesAndInputs() {
   out_ << "  sources =";
   for (const auto& source : target_->sources()) {
     out_ << " ";
-    path_output_.WriteFile(out_, OutputFile(settings_->build_settings(), source));
+    path_output_.WriteFile(out_,
+                           OutputFile(settings_->build_settings(), source));
   }
   for (const auto& data : target_->config_values().inputs()) {
     out_ << " ";
@@ -246,67 +253,99 @@ void NinjaRustBinaryTargetWriter::WriteSourcesAndInputs() {
   out_ << std::endl;
 }
 
-void NinjaRustBinaryTargetWriter::WriteExterns(
-    const std::vector<const Target*>& deps) {
+void NinjaRustBinaryTargetWriter::WriteExternsAndDeps(
+    const std::vector<const Target*>& deps,
+    const std::vector<ExternCrate>& transitive_rust_deps,
+    const std::vector<OutputFile>& rustdeps,
+    const std::vector<OutputFile>& nonrustdeps) {
+  // Writes a external LibFile which comes from user-specified externs, and may
+  // be either a string or a SourceFile.
+  auto write_extern_lib_file = [this](std::string_view crate_name,
+                                      LibFile lib_file) {
+    out_ << " --extern ";
+    out_ << crate_name;
+    out_ << "=";
+    if (lib_file.is_source_file()) {
+      path_output_.WriteFile(out_, lib_file.source_file());
+    } else {
+      EscapeOptions escape_opts_command;
+      escape_opts_command.mode = ESCAPE_NINJA_COMMAND;
+      EscapeStringToStream(out_, lib_file.value(), escape_opts_command);
+    }
+  };
+  // Writes an external OutputFile which comes from a dependency of the current
+  // target.
+  auto write_extern_target = [this](const Target& dep) {
+    std::string_view crate_name;
+    const auto& aliased_deps = target_->rust_values().aliased_deps();
+    if (auto it = aliased_deps.find(dep.label()); it != aliased_deps.end()) {
+      crate_name = it->second;
+    } else {
+      crate_name = dep.rust_values().crate_name();
+    }
+
+    out_ << " --extern ";
+    out_ << crate_name;
+    out_ << "=";
+    path_output_.WriteFile(out_, dep.dependency_output_file());
+  };
+
+  // Write accessible crates with `--extern` to add them to the extern prelude.
   out_ << "  externs =";
 
-  for (const Target* target : deps) {
-    if (target->output_type() == Target::RUST_LIBRARY ||
-        target->output_type() == Target::RUST_PROC_MACRO ||
-        (target->source_types_used().RustSourceUsed() &&
-         target->rust_values().InferredCrateType(target) ==
-             RustValues::CRATE_DYLIB)) {
-      out_ << " --extern ";
-      const auto& renamed_dep =
-          target_->rust_values().aliased_deps().find(target->label());
-      if (renamed_dep != target_->rust_values().aliased_deps().end()) {
-        out_ << renamed_dep->second << "=";
-      } else {
-        out_ << std::string(target->rust_values().crate_name()) << "=";
+  // Tracking to avoid emitted the same lib twice. We track it instead of
+  // pre-emptively constructing a UniqueVector since we would have to also store
+  // the crate name, and in the future the public-ness.
+  std::unordered_set<OutputFile> emitted_rust_libs;
+  // TODO: We defer private dependencies to -Ldependency until --extern priv is
+  // stabilized.
+  UniqueVector<SourceDir> private_extern_dirs;
+
+  // Walk the transitive closure of all rust dependencies.
+  //
+  // For dependencies that are meant to be accessible we pass them to --extern
+  // in order to add them to the crate's extern prelude.
+  //
+  // For all transitive dependencies, we add them to `private_extern_dirs` in
+  // order to generate a -Ldependency switch that points to them. This ensures
+  // that rustc can find them if they are used by other dependencies. For
+  // example:
+  //
+  //   A -> C --public--> D
+  //     -> B --private-> D
+  //
+  // Here A has direct access to D, but B and C also make use of D, and they
+  // will only search the paths specified to -Ldependency, thus D needs to
+  // appear as both a --extern (for A) and -Ldependency (for B and C).
+  for (const auto& crate : transitive_rust_deps) {
+    const OutputFile& rust_lib = crate.target->dependency_output_file();
+    if (emitted_rust_libs.count(rust_lib) == 0) {
+      if (crate.has_direct_access) {
+        write_extern_target(*crate.target);
       }
-      path_output_.WriteFile(out_, target->dependency_output_file());
+      emitted_rust_libs.insert(rust_lib);
     }
+    private_extern_dirs.push_back(
+        rust_lib.AsSourceFile(settings_->build_settings()).GetDir());
   }
 
-  EscapeOptions extern_escape_opts;
-  extern_escape_opts.mode = ESCAPE_NINJA_COMMAND;
-
+  // Add explicitly specified externs from the GN target.
   for (ConfigValuesIterator iter(target_); !iter.done(); iter.Next()) {
     const ConfigValues& cur = iter.cur();
-    for (const auto& e : cur.externs()) {
-      out_ << " --extern " << std::string(e.first) << "=";
-      if (e.second.is_source_file()) {
-        path_output_.WriteFile(out_, e.second.source_file());
-      } else {
-        EscapeStringToStream(out_, e.second.value(), extern_escape_opts);
-      }
+    for (const auto& [crate_name, lib_file] : cur.externs()) {
+      write_extern_lib_file(crate_name, lib_file);
     }
   }
 
   out_ << std::endl;
-}
-
-void NinjaRustBinaryTargetWriter::WriteRustdeps(
-    const std::vector<OutputFile>& transitive_rustdeps,
-    const std::vector<OutputFile>& rustdeps,
-    const std::vector<OutputFile>& nonrustdeps) {
   out_ << "  rustdeps =";
 
-  // Rust dependencies.
-  UniqueVector<SourceDir> transitive_rustdep_dirs;
-  for (const auto& rustdep : transitive_rustdeps) {
-    // TODO switch to using --extern priv: after stabilization
-    transitive_rustdep_dirs.push_back(
-        rustdep.AsSourceFile(settings_->build_settings()).GetDir());
-  }
-  for (const auto& rustdepdir : transitive_rustdep_dirs) {
+  for (const SourceDir& dir : private_extern_dirs) {
+    // TODO: switch to using `--extern priv:name` after stabilization.
     out_ << " -Ldependency=";
-    path_output_.WriteDir(out_, rustdepdir, PathOutput::DIR_NO_LAST_SLASH);
+    path_output_.WriteDir(out_, dir, PathOutput::DIR_NO_LAST_SLASH);
   }
 
-  EscapeOptions lib_escape_opts;
-  lib_escape_opts.mode = ESCAPE_NINJA_COMMAND;
-
   // Non-Rust native dependencies.
   UniqueVector<SourceDir> nonrustdep_dirs;
   for (const auto& nonrustdep : nonrustdeps) {
diff --git a/gn/src/gn/ninja_rust_binary_target_writer.h b/gn/src/gn/ninja_rust_binary_target_writer.h
index 0319c86292a..69ec916454b 100644
--- a/gn/src/gn/ninja_rust_binary_target_writer.h
+++ b/gn/src/gn/ninja_rust_binary_target_writer.h
@@ -6,9 +6,9 @@
 #define TOOLS_GN_NINJA_RUST_BINARY_TARGET_WRITER_H_
 
 #include "gn/ninja_binary_target_writer.h"
+#include "gn/output_file.h"
 #include "gn/rust_tool.h"
-
-struct EscapeOptions;
+#include "gn/target.h"
 
 // Writes a .ninja file for a binary target type (an executable, a shared
 // library, or a static library).
@@ -20,13 +20,18 @@ class NinjaRustBinaryTargetWriter : public NinjaBinaryTargetWriter {
   void Run() override;
 
  private:
+  struct ExternCrate {
+    const Target* target;
+    bool has_direct_access;
+  };
+
   void WriteCompilerVars();
   void WriteSources(const OutputFile& input_dep,
                     const std::vector<OutputFile>& order_only_deps);
-  void WriteExterns(const std::vector<const Target*>& deps);
-  void WriteRustdeps(const std::vector<OutputFile>& transitive_rustdeps,
-                     const std::vector<OutputFile>& rustdeps,
-                     const std::vector<OutputFile>& nonrustdeps);
+  void WriteExternsAndDeps(const std::vector<const Target*>& deps,
+                           const std::vector<ExternCrate>& transitive_rust_deps,
+                           const std::vector<OutputFile>& rustdeps,
+                           const std::vector<OutputFile>& nonrustdeps);
   // Unlike C/C++, Rust compiles all sources of a crate in one command.
   // Write a ninja variable `sources` that contains all sources and input files.
   void WriteSourcesAndInputs();
diff --git a/gn/src/gn/ninja_rust_binary_target_writer_unittest.cc b/gn/src/gn/ninja_rust_binary_target_writer_unittest.cc
index b4b71d64ee2..41a9fdd5f74 100644
--- a/gn/src/gn/ninja_rust_binary_target_writer_unittest.cc
+++ b/gn/src/gn/ninja_rust_binary_target_writer_unittest.cc
@@ -5,6 +5,7 @@
 #include "gn/ninja_rust_binary_target_writer.h"
 
 #include "gn/config.h"
+#include "gn/pool.h"
 #include "gn/rust_values.h"
 #include "gn/scheduler.h"
 #include "gn/target.h"
@@ -64,6 +65,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, RustExecutable) {
         "\n"
         "build ./foo_bar: rust_bin ../../foo/main.rs | ../../foo/input3.rs "
         "../../foo/main.rs\n"
+        "  source_file_part = main.rs\n"
+        "  source_name_part = main\n"
         "  externs =\n"
         "  rustdeps =\n"
         "  ldflags = -fsanitize=address\n"
@@ -73,71 +76,164 @@ TEST_F(NinjaRustBinaryTargetWriterTest, RustExecutable) {
   }
 }
 
+// Accessible dependencies appear as --extern switches for rustc, so that the
+// target crate can make use of them whether transitive or not. Transitive
+// dependencies can be accessible if they are in the public_deps of a direct
+// dependency, or part of a chain of public_deps from a direct dependency. Any
+// dependencies used by other crate dependencies also must appear, but are
+// pointed to by -Ldependency as they are not available for use from the target
+// crate. In the future they may move to `--extern priv:` when explicit private
+// dependencies are stabilized.
 TEST_F(NinjaRustBinaryTargetWriterTest, RlibDeps) {
   Err err;
   TestWithScope setup;
 
-  Target rlib(setup.settings(), Label(SourceDir("//bar/"), "mylib"));
-  rlib.set_output_type(Target::RUST_LIBRARY);
-  rlib.visibility().SetPublic();
-  SourceFile barlib("//bar/lib.rs");
-  rlib.sources().push_back(SourceFile("//bar/mylib.rs"));
-  rlib.sources().push_back(barlib);
-  rlib.source_types_used().Set(SourceFile::SOURCE_RS);
-  rlib.rust_values().set_crate_root(barlib);
-  rlib.rust_values().crate_name() = "mylib";
-  rlib.SetToolchain(setup.toolchain());
-  ASSERT_TRUE(rlib.OnResolved(&err));
+  Target private_rlib(setup.settings(), Label(SourceDir("//baz/"), "privatelib"));
+  private_rlib.set_output_type(Target::RUST_LIBRARY);
+  private_rlib.visibility().SetPublic();
+  SourceFile bazlib("//baz/lib.rs");
+  private_rlib.sources().push_back(SourceFile("//baz/privatelib.rs"));
+  private_rlib.sources().push_back(bazlib);
+  private_rlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  private_rlib.rust_values().set_crate_root(bazlib);
+  private_rlib.rust_values().crate_name() = "privatecrate";
+  private_rlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(private_rlib.OnResolved(&err));
 
   {
     std::ostringstream out;
-    NinjaRustBinaryTargetWriter writer(&rlib, out);
+    NinjaRustBinaryTargetWriter writer(&private_rlib, out);
     writer.Run();
 
     const char expected[] =
-        "crate_name = mylib\n"
+        "crate_name = privatecrate\n"
         "crate_type = rlib\n"
         "output_extension = .rlib\n"
         "output_dir = \n"
         "rustflags =\n"
         "rustenv =\n"
         "root_out_dir = .\n"
-        "target_out_dir = obj/bar\n"
-        "target_output_name = libmylib\n"
+        "target_out_dir = obj/baz\n"
+        "target_output_name = libprivatelib\n"
         "\n"
-        "build obj/bar/libmylib.rlib: rust_rlib ../../bar/lib.rs | "
-        "../../bar/mylib.rs ../../bar/lib.rs\n"
+        "build obj/baz/libprivatelib.rlib: rust_rlib ../../baz/lib.rs | "
+        "../../baz/privatelib.rs ../../baz/lib.rs\n"
+        "  source_file_part = lib.rs\n"
+        "  source_name_part = lib\n"
         "  externs =\n"
         "  rustdeps =\n"
         "  ldflags =\n"
-        "  sources = ../../bar/mylib.rs ../../bar/lib.rs\n";
+        "  sources = ../../baz/privatelib.rs ../../baz/lib.rs\n";
+    std::string out_str = out.str();
+    EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+  }
+
+  Target far_public_rlib(setup.settings(),
+                         Label(SourceDir("//far/"), "farlib"));
+  far_public_rlib.set_output_type(Target::RUST_LIBRARY);
+  far_public_rlib.visibility().SetPublic();
+  SourceFile farlib("//far/lib.rs");
+  far_public_rlib.sources().push_back(SourceFile("//far/farlib.rs"));
+  far_public_rlib.sources().push_back(farlib);
+  far_public_rlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  far_public_rlib.rust_values().set_crate_root(farlib);
+  far_public_rlib.rust_values().crate_name() = "farcrate";
+  far_public_rlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(far_public_rlib.OnResolved(&err));
+
+  {
+    std::ostringstream out;
+    NinjaRustBinaryTargetWriter writer(&far_public_rlib, out);
+    writer.Run();
+
+    const char expected[] =
+        "crate_name = farcrate\n"
+        "crate_type = rlib\n"
+        "output_extension = .rlib\n"
+        "output_dir = \n"
+        "rustflags =\n"
+        "rustenv =\n"
+        "root_out_dir = .\n"
+        "target_out_dir = obj/far\n"
+        "target_output_name = libfarlib\n"
+        "\n"
+        "build obj/far/libfarlib.rlib: rust_rlib ../../far/lib.rs | "
+        "../../far/farlib.rs ../../far/lib.rs\n"
+        "  source_file_part = lib.rs\n"
+        "  source_name_part = lib\n"
+        "  externs =\n"
+        "  rustdeps =\n"
+        "  ldflags =\n"
+        "  sources = ../../far/farlib.rs ../../far/lib.rs\n";
+    std::string out_str = out.str();
+    EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+  }
+
+  Target public_rlib(setup.settings(), Label(SourceDir("//bar/"), "publiclib"));
+  public_rlib.set_output_type(Target::RUST_LIBRARY);
+  public_rlib.visibility().SetPublic();
+  SourceFile barlib("//bar/lib.rs");
+  public_rlib.sources().push_back(SourceFile("//bar/publiclib.rs"));
+  public_rlib.sources().push_back(barlib);
+  public_rlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  public_rlib.rust_values().set_crate_root(barlib);
+  public_rlib.rust_values().crate_name() = "publiccrate";
+  public_rlib.public_deps().push_back(LabelTargetPair(&far_public_rlib));
+  public_rlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(public_rlib.OnResolved(&err));
+
+  {
+    std::ostringstream out;
+    NinjaRustBinaryTargetWriter writer(&public_rlib, out);
+    writer.Run();
+
+    const char expected[] =
+        "crate_name = publiccrate\n"
+        "crate_type = rlib\n"
+        "output_extension = .rlib\n"
+        "output_dir = \n"
+        "rustflags =\n"
+        "rustenv =\n"
+        "root_out_dir = .\n"
+        "target_out_dir = obj/bar\n"
+        "target_output_name = libpubliclib\n"
+        "\n"
+        "build obj/bar/libpubliclib.rlib: rust_rlib ../../bar/lib.rs | "
+        "../../bar/publiclib.rs ../../bar/lib.rs obj/far/libfarlib.rlib\n"
+        "  source_file_part = lib.rs\n"
+        "  source_name_part = lib\n"
+        "  externs = --extern farcrate=obj/far/libfarlib.rlib\n"
+        "  rustdeps = -Ldependency=obj/far\n"
+        "  ldflags =\n"
+        "  sources = ../../bar/publiclib.rs ../../bar/lib.rs\n";
     std::string out_str = out.str();
     EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
   }
 
-  Target another_rlib(setup.settings(), Label(SourceDir("//foo/"), "direct"));
-  another_rlib.set_output_type(Target::RUST_LIBRARY);
-  another_rlib.visibility().SetPublic();
+  Target rlib(setup.settings(), Label(SourceDir("//foo/"), "direct"));
+  rlib.set_output_type(Target::RUST_LIBRARY);
+  rlib.visibility().SetPublic();
   SourceFile lib("//foo/main.rs");
-  another_rlib.sources().push_back(SourceFile("//foo/direct.rs"));
-  another_rlib.sources().push_back(lib);
-  another_rlib.source_types_used().Set(SourceFile::SOURCE_RS);
-  another_rlib.rust_values().set_crate_root(lib);
-  another_rlib.rust_values().crate_name() = "direct";
-  another_rlib.SetToolchain(setup.toolchain());
-  another_rlib.public_deps().push_back(LabelTargetPair(&rlib));
-  ASSERT_TRUE(another_rlib.OnResolved(&err));
+  rlib.sources().push_back(SourceFile("//foo/direct.rs"));
+  rlib.sources().push_back(lib);
+  rlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  rlib.rust_values().set_crate_root(lib);
+  rlib.rust_values().crate_name() = "direct";
+  rlib.SetToolchain(setup.toolchain());
+  rlib.public_deps().push_back(LabelTargetPair(&public_rlib));
+  rlib.private_deps().push_back(LabelTargetPair(&private_rlib));
+  ASSERT_TRUE(rlib.OnResolved(&err));
 
-  Target target(setup.settings(), Label(SourceDir("//foo/"), "bar"));
+  Target target(setup.settings(), Label(SourceDir("//main/"), "main"));
   target.set_output_type(Target::EXECUTABLE);
   target.visibility().SetPublic();
-  SourceFile main("//foo/main.rs");
-  target.sources().push_back(SourceFile("//foo/source.rs"));
+  SourceFile main("//main/main.rs");
+  target.sources().push_back(SourceFile("//main/source.rs"));
   target.sources().push_back(main);
   target.source_types_used().Set(SourceFile::SOURCE_RS);
   target.rust_values().set_crate_root(main);
-  target.rust_values().crate_name() = "foo_bar";
-  target.private_deps().push_back(LabelTargetPair(&another_rlib));
+  target.rust_values().crate_name() = "main_crate";
+  target.private_deps().push_back(LabelTargetPair(&rlib));
   target.SetToolchain(setup.toolchain());
   ASSERT_TRUE(target.OnResolved(&err));
 
@@ -147,22 +243,29 @@ TEST_F(NinjaRustBinaryTargetWriterTest, RlibDeps) {
     writer.Run();
 
     const char expected[] =
-        "crate_name = foo_bar\n"
+        "crate_name = main_crate\n"
         "crate_type = bin\n"
         "output_extension = \n"
         "output_dir = \n"
         "rustflags =\n"
         "rustenv =\n"
         "root_out_dir = .\n"
-        "target_out_dir = obj/foo\n"
-        "target_output_name = bar\n"
+        "target_out_dir = obj/main\n"
+        "target_output_name = main\n"
         "\n"
-        "build ./foo_bar: rust_bin ../../foo/main.rs | ../../foo/source.rs "
-        "../../foo/main.rs obj/foo/libdirect.rlib\n"
-        "  externs = --extern direct=obj/foo/libdirect.rlib\n"
-        "  rustdeps = -Ldependency=obj/foo -Ldependency=obj/bar\n"
+        "build ./main_crate: rust_bin ../../main/main.rs | "
+        "../../main/source.rs ../../main/main.rs obj/foo/libdirect.rlib "
+        "obj/bar/libpubliclib.rlib obj/far/libfarlib.rlib "
+        "obj/baz/libprivatelib.rlib\n"
+        "  source_file_part = main.rs\n"
+        "  source_name_part = main\n"
+        "  externs = --extern direct=obj/foo/libdirect.rlib "
+        "--extern publiccrate=obj/bar/libpubliclib.rlib "
+        "--extern farcrate=obj/far/libfarlib.rlib\n"
+        "  rustdeps = -Ldependency=obj/foo -Ldependency=obj/bar "
+        "-Ldependency=obj/far -Ldependency=obj/baz\n"
         "  ldflags =\n"
-        "  sources = ../../foo/source.rs ../../foo/main.rs\n";
+        "  sources = ../../main/source.rs ../../main/main.rs\n";
     std::string out_str = out.str();
     EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
   }
@@ -172,6 +275,86 @@ TEST_F(NinjaRustBinaryTargetWriterTest, DylibDeps) {
   Err err;
   TestWithScope setup;
 
+  Target private_inside_dylib(setup.settings(), Label(SourceDir("//faz/"), "private_inside"));
+  private_inside_dylib.set_output_type(Target::RUST_LIBRARY);
+  private_inside_dylib.visibility().SetPublic();
+  SourceFile fazlib("//faz/lib.rs");
+  private_inside_dylib.sources().push_back(SourceFile("//faz/private_inside.rs"));
+  private_inside_dylib.sources().push_back(fazlib);
+  private_inside_dylib.source_types_used().Set(SourceFile::SOURCE_RS);
+  private_inside_dylib.rust_values().set_crate_root(fazlib);
+  private_inside_dylib.rust_values().crate_name() = "private_inside";
+  private_inside_dylib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(private_inside_dylib.OnResolved(&err));
+
+  {
+    std::ostringstream out;
+    NinjaRustBinaryTargetWriter writer(&private_inside_dylib, out);
+    writer.Run();
+
+    const char expected[] =
+        "crate_name = private_inside\n"
+        "crate_type = rlib\n"
+        "output_extension = .rlib\n"
+        "output_dir = \n"
+        "rustflags =\n"
+        "rustenv =\n"
+        "root_out_dir = .\n"
+        "target_out_dir = obj/faz\n"
+        "target_output_name = libprivate_inside\n"
+        "\n"
+        "build obj/faz/libprivate_inside.rlib: rust_rlib ../../faz/lib.rs | "
+        "../../faz/private_inside.rs ../../faz/lib.rs\n"
+        "  source_file_part = lib.rs\n"
+        "  source_name_part = lib\n"
+        "  externs =\n"
+        "  rustdeps =\n"
+        "  ldflags =\n"
+        "  sources = ../../faz/private_inside.rs ../../faz/lib.rs\n";
+    std::string out_str = out.str();
+    EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+  }
+
+  Target inside_dylib(setup.settings(), Label(SourceDir("//baz/"), "inside"));
+  inside_dylib.set_output_type(Target::RUST_LIBRARY);
+  inside_dylib.visibility().SetPublic();
+  SourceFile bazlib("//baz/lib.rs");
+  inside_dylib.sources().push_back(SourceFile("//baz/inside.rs"));
+  inside_dylib.sources().push_back(bazlib);
+  inside_dylib.source_types_used().Set(SourceFile::SOURCE_RS);
+  inside_dylib.rust_values().set_crate_root(bazlib);
+  inside_dylib.rust_values().crate_name() = "inside";
+  inside_dylib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(inside_dylib.OnResolved(&err));
+
+  {
+    std::ostringstream out;
+    NinjaRustBinaryTargetWriter writer(&inside_dylib, out);
+    writer.Run();
+
+    const char expected[] =
+        "crate_name = inside\n"
+        "crate_type = rlib\n"
+        "output_extension = .rlib\n"
+        "output_dir = \n"
+        "rustflags =\n"
+        "rustenv =\n"
+        "root_out_dir = .\n"
+        "target_out_dir = obj/baz\n"
+        "target_output_name = libinside\n"
+        "\n"
+        "build obj/baz/libinside.rlib: rust_rlib ../../baz/lib.rs | "
+        "../../baz/inside.rs ../../baz/lib.rs\n"
+        "  source_file_part = lib.rs\n"
+        "  source_name_part = lib\n"
+        "  externs =\n"
+        "  rustdeps =\n"
+        "  ldflags =\n"
+        "  sources = ../../baz/inside.rs ../../baz/lib.rs\n";
+    std::string out_str = out.str();
+    EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+  }
+
   Target dylib(setup.settings(), Label(SourceDir("//bar/"), "mylib"));
   dylib.set_output_type(Target::SHARED_LIBRARY);
   dylib.visibility().SetPublic();
@@ -179,9 +362,11 @@ TEST_F(NinjaRustBinaryTargetWriterTest, DylibDeps) {
   dylib.sources().push_back(SourceFile("//bar/mylib.rs"));
   dylib.sources().push_back(barlib);
   dylib.source_types_used().Set(SourceFile::SOURCE_RS);
-  dylib.rust_values().set_crate_type(RustValues::CRATE_DYLIB); // TODO
+  dylib.rust_values().set_crate_type(RustValues::CRATE_DYLIB);
   dylib.rust_values().set_crate_root(barlib);
   dylib.rust_values().crate_name() = "mylib";
+  dylib.public_deps().push_back(LabelTargetPair(&inside_dylib));
+  dylib.private_deps().push_back(LabelTargetPair(&private_inside_dylib));
   dylib.SetToolchain(setup.toolchain());
   ASSERT_TRUE(dylib.OnResolved(&err));
 
@@ -202,15 +387,32 @@ TEST_F(NinjaRustBinaryTargetWriterTest, DylibDeps) {
         "target_output_name = libmylib\n"
         "\n"
         "build obj/bar/libmylib.so: rust_dylib ../../bar/lib.rs | "
-        "../../bar/mylib.rs ../../bar/lib.rs\n"
-        "  externs =\n"
-        "  rustdeps =\n"
+        "../../bar/mylib.rs ../../bar/lib.rs "
+        "obj/baz/libinside.rlib obj/faz/libprivate_inside.rlib\n"
+        "  source_file_part = lib.rs\n"
+        "  source_name_part = lib\n"
+        "  externs = --extern inside=obj/baz/libinside.rlib "
+        "--extern private_inside=obj/faz/libprivate_inside.rlib\n"
+        "  rustdeps = -Ldependency=obj/baz -Ldependency=obj/faz\n"
         "  ldflags =\n"
         "  sources = ../../bar/mylib.rs ../../bar/lib.rs\n";
     std::string out_str = out.str();
     EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
   }
 
+  Target private_dylib(setup.settings(), Label(SourceDir("//private_dylib/"), "private_dylib"));
+  private_dylib.set_output_type(Target::SHARED_LIBRARY);
+  private_dylib.visibility().SetPublic();
+  SourceFile private_dyliblib("//private_dylib/lib.rs");
+  private_dylib.sources().push_back(SourceFile("//private_dylib/mylib.rs"));
+  private_dylib.sources().push_back(private_dyliblib);
+  private_dylib.source_types_used().Set(SourceFile::SOURCE_RS);
+  private_dylib.rust_values().set_crate_type(RustValues::CRATE_DYLIB);
+  private_dylib.rust_values().set_crate_root(private_dyliblib);
+  private_dylib.rust_values().crate_name() = "private_dylib";
+  private_dylib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(private_dylib.OnResolved(&err));
+
   Target another_dylib(setup.settings(), Label(SourceDir("//foo/"), "direct"));
   another_dylib.set_output_type(Target::SHARED_LIBRARY);
   another_dylib.visibility().SetPublic();
@@ -222,7 +424,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, DylibDeps) {
   another_dylib.rust_values().set_crate_root(lib);
   another_dylib.rust_values().crate_name() = "direct";
   another_dylib.SetToolchain(setup.toolchain());
-  another_dylib.private_deps().push_back(LabelTargetPair(&dylib));
+  another_dylib.public_deps().push_back(LabelTargetPair(&dylib));
+  another_dylib.private_deps().push_back(LabelTargetPair(&private_dylib));
   ASSERT_TRUE(another_dylib.OnResolved(&err));
 
   Target target(setup.settings(), Label(SourceDir("//foo/"), "bar"));
@@ -255,9 +458,16 @@ TEST_F(NinjaRustBinaryTargetWriterTest, DylibDeps) {
         "target_output_name = bar\n"
         "\n"
         "build ./foo_bar: rust_bin ../../foo/main.rs | ../../foo/source.rs "
-        "../../foo/main.rs obj/foo/libdirect.so\n"
-        "  externs = --extern direct=obj/foo/libdirect.so\n"
-        "  rustdeps = -Ldependency=obj/foo -Ldependency=obj/bar\n"
+        "../../foo/main.rs obj/foo/libdirect.so obj/bar/libmylib.so "
+        "obj/baz/libinside.rlib\n"
+        "  source_file_part = main.rs\n"
+        "  source_name_part = main\n"
+        "  externs = --extern direct=obj/foo/libdirect.so "
+        "--extern mylib=obj/bar/libmylib.so "
+        "--extern inside=obj/baz/libinside.rlib\n"
+        "  rustdeps = -Ldependency=obj/foo -Ldependency=obj/bar "
+        "-Ldependency=obj/baz -Ldependency=obj/faz "
+        "-Ldependency=obj/private_dylib\n"
         "  ldflags =\n"
         "  sources = ../../foo/source.rs ../../foo/main.rs\n";
     std::string out_str = out.str();
@@ -300,6 +510,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, RlibDepsAcrossGroups) {
         "\n"
         "build obj/bar/libmymacro.so: rust_macro ../../bar/lib.rs | "
         "../../bar/mylib.rs ../../bar/lib.rs\n"
+        "  source_file_part = lib.rs\n"
+        "  source_name_part = lib\n"
         "  externs =\n"
         "  rustdeps =\n"
         "  ldflags =\n"
@@ -308,6 +520,13 @@ TEST_F(NinjaRustBinaryTargetWriterTest, RlibDepsAcrossGroups) {
     EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
   }
 
+  // A group produces an order-only dependency in ninja:
+  // https://ninja-build.org/manual.html#ref_dependencies.
+  //
+  // If a crate D inside the group is visible to a crate C depending on the
+  // group, the crate C needs to be rebuilt when D is changed. The group
+  // dependency does not guarantee that it would, so we test that C has an
+  // indirect dependency on D through this group.
   Target group(setup.settings(), Label(SourceDir("//baz/"), "group"));
   group.set_output_type(Target::GROUP);
   group.visibility().SetPublic();
@@ -333,6 +552,10 @@ TEST_F(NinjaRustBinaryTargetWriterTest, RlibDepsAcrossGroups) {
     NinjaRustBinaryTargetWriter writer(&rlib, out);
     writer.Run();
 
+    // libmymacro.so is inside the obj/baz/group, so would be built before
+    // libmylib.rlib. However it must also cause libmylib.rlib to be recompiled
+    // when changed, so we expect an implicit dependency (appearing after `|` on
+    // the build line) from libmylib.rlib to libmymacro.so.
     const char expected[] =
         "crate_name = mylib\n"
         "crate_type = rlib\n"
@@ -347,6 +570,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, RlibDepsAcrossGroups) {
         "build obj/bar/libmylib.rlib: rust_rlib ../../bar/lib.rs | "
         "../../bar/mylib.rs ../../bar/lib.rs obj/bar/libmymacro.so || "
         "obj/baz/group.stamp\n"
+        "  source_file_part = lib.rs\n"
+        "  source_name_part = lib\n"
         "  externs = --extern mymacro=obj/bar/libmymacro.so\n"
         "  rustdeps = -Ldependency=obj/bar\n"
         "  ldflags =\n"
@@ -385,8 +610,12 @@ TEST_F(NinjaRustBinaryTargetWriterTest, RlibDepsAcrossGroups) {
         "target_output_name = bar\n"
         "\n"
         "build ./foo_bar: rust_bin ../../foo/main.rs | "
-        "../../foo/source.rs ../../foo/main.rs obj/bar/libmylib.rlib\n"
-        "  externs = --extern mylib=obj/bar/libmylib.rlib\n"
+        "../../foo/source.rs ../../foo/main.rs "
+        "obj/bar/libmylib.rlib obj/bar/libmymacro.so\n"
+        "  source_file_part = main.rs\n"
+        "  source_name_part = main\n"
+        "  externs = --extern mylib=obj/bar/libmylib.rlib "
+        "--extern mymacro=obj/bar/libmymacro.so\n"
         "  rustdeps = -Ldependency=obj/bar\n"
         "  ldflags =\n"
         "  sources = ../../foo/source.rs ../../foo/main.rs\n";
@@ -399,17 +628,42 @@ TEST_F(NinjaRustBinaryTargetWriterTest, RenamedDeps) {
   Err err;
   TestWithScope setup;
 
-  Target another_rlib(setup.settings(), Label(SourceDir("//foo/"), "direct"));
-  another_rlib.set_output_type(Target::RUST_LIBRARY);
-  another_rlib.visibility().SetPublic();
-  SourceFile lib("//foo/lib.rs");
-  another_rlib.sources().push_back(SourceFile("//foo/direct.rs"));
-  another_rlib.sources().push_back(lib);
-  another_rlib.source_types_used().Set(SourceFile::SOURCE_RS);
-  another_rlib.rust_values().set_crate_root(lib);
-  another_rlib.rust_values().crate_name() = "direct";
-  another_rlib.SetToolchain(setup.toolchain());
-  ASSERT_TRUE(another_rlib.OnResolved(&err));
+  Target transitive(setup.settings(), Label(SourceDir("//faz/"), "transitive"));
+  transitive.set_output_type(Target::RUST_LIBRARY);
+  transitive.visibility().SetPublic();
+  SourceFile transitive_lib("//faz/transitive/lib.rs");
+  transitive.sources().push_back(SourceFile("//faz/transitive/transitive.rs"));
+  transitive.sources().push_back(transitive_lib);
+  transitive.source_types_used().Set(SourceFile::SOURCE_RS);
+  transitive.rust_values().set_crate_root(transitive_lib);
+  transitive.rust_values().crate_name() = "transitive";
+  transitive.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(transitive.OnResolved(&err));
+
+  Target rlib(setup.settings(), Label(SourceDir("//baz/"), "mylib"));
+  rlib.set_output_type(Target::RUST_LIBRARY);
+  rlib.visibility().SetPublic();
+  SourceFile barlib("//baz/bar/lib.rs");
+  rlib.sources().push_back(SourceFile("//baz/bar/mylib.rs"));
+  rlib.sources().push_back(barlib);
+  rlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  rlib.rust_values().set_crate_root(barlib);
+  rlib.rust_values().crate_name() = "mylib";
+  rlib.SetToolchain(setup.toolchain());
+  rlib.public_deps().push_back(LabelTargetPair(&transitive));
+  ASSERT_TRUE(rlib.OnResolved(&err));
+
+  Target direct(setup.settings(), Label(SourceDir("//bar/"), "direct"));
+  direct.set_output_type(Target::RUST_LIBRARY);
+  direct.visibility().SetPublic();
+  SourceFile direct_lib("//bar/direct/lib.rs");
+  direct.sources().push_back(SourceFile("//bar/direct/direct.rs"));
+  direct.sources().push_back(direct_lib);
+  direct.source_types_used().Set(SourceFile::SOURCE_RS);
+  direct.rust_values().set_crate_root(direct_lib);
+  direct.rust_values().crate_name() = "direct";
+  direct.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(direct.OnResolved(&err));
 
   Target target(setup.settings(), Label(SourceDir("//foo/"), "bar"));
   target.set_output_type(Target::EXECUTABLE);
@@ -420,8 +674,13 @@ TEST_F(NinjaRustBinaryTargetWriterTest, RenamedDeps) {
   target.source_types_used().Set(SourceFile::SOURCE_RS);
   target.rust_values().set_crate_root(main);
   target.rust_values().crate_name() = "foo_bar";
-  target.rust_values().aliased_deps()[another_rlib.label()] = "direct_renamed";
-  target.private_deps().push_back(LabelTargetPair(&another_rlib));
+  // A direct dependency is renamed.
+  target.rust_values().aliased_deps()[direct.label()] = "direct_renamed";
+  // A transitive public dependency, through `rlib`, is renamed.
+  target.rust_values().aliased_deps()[transitive.label()] =
+      "transitive_renamed";
+  target.private_deps().push_back(LabelTargetPair(&direct));
+  target.private_deps().push_back(LabelTargetPair(&rlib));
   target.SetToolchain(setup.toolchain());
   ASSERT_TRUE(target.OnResolved(&err));
 
@@ -442,9 +701,15 @@ TEST_F(NinjaRustBinaryTargetWriterTest, RenamedDeps) {
         "target_output_name = bar\n"
         "\n"
         "build ./foo_bar: rust_bin ../../foo/main.rs | ../../foo/source.rs "
-        "../../foo/main.rs obj/foo/libdirect.rlib\n"
-        "  externs = --extern direct_renamed=obj/foo/libdirect.rlib\n"
-        "  rustdeps = -Ldependency=obj/foo\n"
+        "../../foo/main.rs obj/bar/libdirect.rlib obj/baz/libmylib.rlib "
+        "obj/faz/libtransitive.rlib\n"
+        "  source_file_part = main.rs\n"
+        "  source_name_part = main\n"
+        "  externs = --extern direct_renamed=obj/bar/libdirect.rlib "
+        "--extern mylib=obj/baz/libmylib.rlib "
+        "--extern transitive_renamed=obj/faz/libtransitive.rlib\n"
+        "  rustdeps = -Ldependency=obj/bar -Ldependency=obj/baz "
+        "-Ldependency=obj/faz\n"
         "  ldflags =\n"
         "  sources = ../../foo/source.rs ../../foo/main.rs\n";
     std::string out_str = out.str();
@@ -542,6 +807,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, NonRustDeps) {
         "obj/bar/libmylib.rlib "
         "obj/foo/libstatic.a ./libshared.so ./libshared_with_toc.so.TOC "
         "|| obj/baz/sourceset.stamp\n"
+        "  source_file_part = main.rs\n"
+        "  source_name_part = main\n"
         "  externs = --extern mylib=obj/bar/libmylib.rlib\n"
         "  rustdeps = -Ldependency=obj/bar "
         "-Lnative=obj/baz -Lnative=obj/foo -Lnative=. "
@@ -584,6 +851,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, NonRustDeps) {
         "\n"
         "build ./foo_bar: rust_bin ../../foo/main.rs | ../../foo/source.rs "
         "../../foo/main.rs obj/foo/libstatic.a\n"
+        "  source_file_part = main.rs\n"
+        "  source_name_part = main\n"
         "  externs =\n"
         "  rustdeps = -Lnative=obj/foo -Clink-arg=-Bdynamic "
         "-Clink-arg=obj/foo/libstatic.a\n"
@@ -624,6 +893,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, NonRustDeps) {
         "build obj/baz/libbaz.a: rust_staticlib ../../baz/lib.rs | "
         "../../baz/lib.rs "
         "obj/foo/libstatic.a\n"
+        "  source_file_part = lib.rs\n"
+        "  source_name_part = lib\n"
         "  externs =\n"
         "  rustdeps = -Lnative=obj/foo -Clink-arg=-Bdynamic "
         "-Clink-arg=obj/foo/libstatic.a\n"
@@ -634,6 +905,196 @@ TEST_F(NinjaRustBinaryTargetWriterTest, NonRustDeps) {
   }
 }
 
+TEST_F(NinjaRustBinaryTargetWriterTest, RlibInLibrary) {
+  Err err;
+  TestWithScope setup;
+
+  Target priv_sset_in_staticlib(
+      setup.settings(),
+      Label(SourceDir("//priv_sset_in_staticlib/"), "priv_sset_in_staticlib"));
+  priv_sset_in_staticlib.set_output_type(Target::SOURCE_SET);
+  priv_sset_in_staticlib.visibility().SetPublic();
+  priv_sset_in_staticlib.sources().push_back(
+      SourceFile("//priv_sset_in_staticlib/lib.cc"));
+  priv_sset_in_staticlib.source_types_used().Set(SourceFile::SOURCE_CPP);
+  priv_sset_in_staticlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(priv_sset_in_staticlib.OnResolved(&err));
+
+  Target pub_sset_in_staticlib(
+      setup.settings(),
+      Label(SourceDir("//pub_sset_in_staticlib/"), "pub_sset_in_staticlib"));
+  pub_sset_in_staticlib.set_output_type(Target::SOURCE_SET);
+  pub_sset_in_staticlib.visibility().SetPublic();
+  pub_sset_in_staticlib.sources().push_back(
+      SourceFile("//pub_sset_in_staticlib/lib.cc"));
+  pub_sset_in_staticlib.source_types_used().Set(SourceFile::SOURCE_CPP);
+  pub_sset_in_staticlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(pub_sset_in_staticlib.OnResolved(&err));
+
+  Target priv_sset_in_dylib(
+      setup.settings(),
+      Label(SourceDir("//priv_sset_in_dylib/"), "priv_sset_in_dylib"));
+  priv_sset_in_dylib.set_output_type(Target::SOURCE_SET);
+  priv_sset_in_dylib.visibility().SetPublic();
+  priv_sset_in_dylib.sources().push_back(
+      SourceFile("//priv_sset_in_dylib/lib.cc"));
+  priv_sset_in_dylib.source_types_used().Set(SourceFile::SOURCE_CPP);
+  priv_sset_in_dylib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(priv_sset_in_dylib.OnResolved(&err));
+
+  Target pub_sset_in_dylib(
+      setup.settings(),
+      Label(SourceDir("//pub_sset_in_dylib"), "pub_sset_in_dylib"));
+  pub_sset_in_dylib.set_output_type(Target::SOURCE_SET);
+  pub_sset_in_dylib.visibility().SetPublic();
+  pub_sset_in_dylib.sources().push_back(
+      SourceFile("//pub_sset_in_dylib/lib.cc"));
+  pub_sset_in_dylib.source_types_used().Set(SourceFile::SOURCE_CPP);
+  pub_sset_in_dylib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(pub_sset_in_dylib.OnResolved(&err));
+
+  Target priv_in_staticlib(
+      setup.settings(),
+      Label(SourceDir("//priv_in_staticlib/"), "priv_in_staticlib"));
+  priv_in_staticlib.set_output_type(Target::RUST_LIBRARY);
+  priv_in_staticlib.visibility().SetPublic();
+  SourceFile priv_in_staticlib_root("//priv_in_staticlib/lib.rs");
+  priv_in_staticlib.sources().push_back(priv_in_staticlib_root);
+  priv_in_staticlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  priv_in_staticlib.rust_values().set_crate_root(priv_in_staticlib_root);
+  priv_in_staticlib.rust_values().crate_name() = "priv_in_staticlib";
+  priv_in_staticlib.SetToolchain(setup.toolchain());
+  priv_in_staticlib.private_deps().push_back(
+      LabelTargetPair(&priv_sset_in_staticlib));
+  ASSERT_TRUE(priv_in_staticlib.OnResolved(&err));
+
+  Target pub_in_staticlib(
+      setup.settings(),
+      Label(SourceDir("//pub_in_staticlib/"), "pub_in_staticlib"));
+  pub_in_staticlib.set_output_type(Target::RUST_LIBRARY);
+  pub_in_staticlib.visibility().SetPublic();
+  SourceFile pub_in_staticlib_root("//pub_in_staticlib/lib.rs");
+  pub_in_staticlib.sources().push_back(pub_in_staticlib_root);
+  pub_in_staticlib.source_types_used().Set(SourceFile::SOURCE_RS);
+  pub_in_staticlib.rust_values().set_crate_root(pub_in_staticlib_root);
+  pub_in_staticlib.rust_values().crate_name() = "pub_in_staticlib";
+  pub_in_staticlib.SetToolchain(setup.toolchain());
+  pub_in_staticlib.private_deps().push_back(
+      LabelTargetPair(&pub_sset_in_staticlib));
+  ASSERT_TRUE(pub_in_staticlib.OnResolved(&err));
+
+  Target priv_in_dylib(setup.settings(),
+                       Label(SourceDir("//priv_in_dylib/"), "priv_in_dylib"));
+  priv_in_dylib.set_output_type(Target::RUST_LIBRARY);
+  priv_in_dylib.visibility().SetPublic();
+  SourceFile priv_in_dylib_root("//priv_in_dylib/lib.rs");
+  priv_in_dylib.sources().push_back(priv_in_dylib_root);
+  priv_in_dylib.source_types_used().Set(SourceFile::SOURCE_RS);
+  priv_in_dylib.rust_values().set_crate_root(priv_in_dylib_root);
+  priv_in_dylib.rust_values().crate_name() = "priv_in_dylib";
+  priv_in_dylib.SetToolchain(setup.toolchain());
+  priv_in_dylib.private_deps().push_back(LabelTargetPair(&priv_sset_in_dylib));
+  ASSERT_TRUE(priv_in_dylib.OnResolved(&err));
+
+  Target pub_in_dylib(setup.settings(),
+                      Label(SourceDir("//pub_in_dylib/"), "pub_in_dylib"));
+  pub_in_dylib.set_output_type(Target::RUST_LIBRARY);
+  pub_in_dylib.visibility().SetPublic();
+  SourceFile pub_in_dylib_root("//pub_in_dylib/lib.rs");
+  pub_in_dylib.sources().push_back(pub_in_dylib_root);
+  pub_in_dylib.source_types_used().Set(SourceFile::SOURCE_RS);
+  pub_in_dylib.rust_values().set_crate_root(pub_in_dylib_root);
+  pub_in_dylib.rust_values().crate_name() = "pub_in_dylib";
+  pub_in_dylib.SetToolchain(setup.toolchain());
+  pub_in_dylib.private_deps().push_back(LabelTargetPair(&pub_sset_in_dylib));
+  ASSERT_TRUE(pub_in_dylib.OnResolved(&err));
+
+  Target staticlib(setup.settings(),
+                   Label(SourceDir("//staticlib/"), "staticlib"));
+  staticlib.set_output_type(Target::STATIC_LIBRARY);
+  staticlib.visibility().SetPublic();
+  staticlib.sources().push_back(SourceFile("//staticlib/lib.cc"));
+  staticlib.source_types_used().Set(SourceFile::SOURCE_CPP);
+  staticlib.public_deps().push_back(LabelTargetPair(&pub_in_staticlib));
+  staticlib.private_deps().push_back(LabelTargetPair(&priv_in_staticlib));
+  staticlib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(staticlib.OnResolved(&err));
+
+  Target dylib(setup.settings(), Label(SourceDir("//dylib/"), "dylib"));
+  dylib.set_output_type(Target::SHARED_LIBRARY);
+  dylib.visibility().SetPublic();
+  SourceFile dylib_root("//dylib/lib.rs");
+  dylib.sources().push_back(dylib_root);
+  dylib.source_types_used().Set(SourceFile::SOURCE_RS);
+  dylib.rust_values().set_crate_root(dylib_root);
+  dylib.rust_values().crate_name() = "dylib";
+  dylib.public_deps().push_back(LabelTargetPair(&pub_in_dylib));
+  dylib.private_deps().push_back(LabelTargetPair(&priv_in_dylib));
+  dylib.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(dylib.OnResolved(&err));
+
+  Target target(setup.settings(), Label(SourceDir("//exe/"), "exe"));
+  target.set_output_type(Target::EXECUTABLE);
+  target.visibility().SetPublic();
+  SourceFile main("//exe/main.rs");
+  target.sources().push_back(main);
+  target.source_types_used().Set(SourceFile::SOURCE_RS);
+  target.rust_values().set_crate_root(main);
+  target.rust_values().crate_name() = "exe";
+  target.private_deps().push_back(LabelTargetPair(&staticlib));
+  target.private_deps().push_back(LabelTargetPair(&dylib));
+  target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target.OnResolved(&err));
+
+
+  std::ostringstream out;
+  NinjaRustBinaryTargetWriter writer(&target, out);
+  writer.Run();
+
+  const char expected[] =
+      "crate_name = exe\n"
+      "crate_type = bin\n"
+      "output_extension = \n"
+      "output_dir = \n"
+      "rustflags =\n"
+      "rustenv =\n"
+      "root_out_dir = .\n"
+      "target_out_dir = obj/exe\n"
+      "target_output_name = exe\n"
+      "\n"
+      "build ./exe: rust_bin ../../exe/main.rs | "
+      "../../exe/main.rs "
+      "obj/pub_sset_in_staticlib/pub_sset_in_staticlib.lib.o "
+      "obj/priv_sset_in_staticlib/priv_sset_in_staticlib.lib.o "
+      "obj/staticlib/libstaticlib.a "
+      "obj/dylib/libdylib.so "
+      "obj/pub_in_staticlib/libpub_in_staticlib.rlib "
+      "obj/priv_in_staticlib/libpriv_in_staticlib.rlib "
+      "obj/pub_in_dylib/libpub_in_dylib.rlib || "
+      "obj/pub_sset_in_staticlib/pub_sset_in_staticlib.stamp "
+      "obj/priv_sset_in_staticlib/priv_sset_in_staticlib.stamp\n"
+      "  source_file_part = main.rs\n"
+      "  source_name_part = main\n"
+      "  externs = "
+      "--extern pub_in_staticlib=obj/pub_in_staticlib/libpub_in_staticlib.rlib "
+      "--extern dylib=obj/dylib/libdylib.so "
+      "--extern pub_in_dylib=obj/pub_in_dylib/libpub_in_dylib.rlib\n"
+      "  rustdeps = -Ldependency=obj/pub_in_staticlib "
+      "-Ldependency=obj/priv_in_staticlib -Ldependency=obj/dylib "
+      "-Ldependency=obj/pub_in_dylib -Ldependency=obj/priv_in_dylib "
+      "-Lnative=obj/pub_sset_in_staticlib "
+      "-Lnative=obj/priv_sset_in_staticlib "
+      "-Lnative=obj/staticlib -Clink-arg=-Bdynamic "
+      "-Clink-arg=obj/pub_sset_in_staticlib/pub_sset_in_staticlib.lib.o "
+      "-Clink-arg=obj/priv_sset_in_staticlib/priv_sset_in_staticlib.lib.o "
+      "-Clink-arg=obj/staticlib/libstaticlib.a\n"
+      "  ldflags =\n"
+      "  sources = ../../exe/main.rs\n";
+
+  std::string out_str = out.str();
+  EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+}
+
 TEST_F(NinjaRustBinaryTargetWriterTest, RustOutputExtensionAndDir) {
   Err err;
   TestWithScope setup;
@@ -670,6 +1131,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, RustOutputExtensionAndDir) {
         "\n"
         "build ./foo_bar.exe: rust_bin ../../foo/main.rs | ../../foo/input3.rs "
         "../../foo/main.rs\n"
+        "  source_file_part = main.rs\n"
+        "  source_name_part = main\n"
         "  externs =\n"
         "  rustdeps =\n"
         "  ldflags =\n"
@@ -716,6 +1179,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, LibsAndLibDirs) {
         "\n"
         "build ./foo_bar: rust_bin ../../foo/main.rs | ../../foo/input.rs "
         "../../foo/main.rs\n"
+        "  source_file_part = main.rs\n"
+        "  source_name_part = main\n"
         "  externs =\n"
         "  rustdeps = -Lnative=../../baz -lquux\n"
         "  ldflags =\n"
@@ -725,22 +1190,39 @@ TEST_F(NinjaRustBinaryTargetWriterTest, LibsAndLibDirs) {
   }
 }
 
+// Test that neither public nor private rust dependencies of a proc-macro are
+// transitively acquired as accessible dependencies by users of the macro. But
+// the macro itself is listed as an accessible dependency (via --extern).
 TEST_F(NinjaRustBinaryTargetWriterTest, RustProcMacro) {
   Err err;
   TestWithScope setup;
 
-  Target procmacrodep(setup.settings(),
-                      Label(SourceDir("//baz/"), "mymacrodep"));
-  procmacrodep.set_output_type(Target::RUST_LIBRARY);
-  procmacrodep.visibility().SetPublic();
-  SourceFile bazlib("//baz/lib.rs");
-  procmacrodep.sources().push_back(SourceFile("//baz/mylib.rs"));
-  procmacrodep.sources().push_back(bazlib);
-  procmacrodep.source_types_used().Set(SourceFile::SOURCE_RS);
-  procmacrodep.rust_values().set_crate_root(bazlib);
-  procmacrodep.rust_values().crate_name() = "mymacrodep";
-  procmacrodep.SetToolchain(setup.toolchain());
-  ASSERT_TRUE(procmacrodep.OnResolved(&err));
+  Target procmacropublicdep(
+      setup.settings(), Label(SourceDir("//baz/public/"), "mymacropublicdep"));
+  procmacropublicdep.set_output_type(Target::RUST_LIBRARY);
+  procmacropublicdep.visibility().SetPublic();
+  SourceFile publicbazlib("//baz/public/lib.rs");
+  procmacropublicdep.sources().push_back(SourceFile("//baz/public/mylib.rs"));
+  procmacropublicdep.sources().push_back(publicbazlib);
+  procmacropublicdep.source_types_used().Set(SourceFile::SOURCE_RS);
+  procmacropublicdep.rust_values().set_crate_root(publicbazlib);
+  procmacropublicdep.rust_values().crate_name() = "publicdep";
+  procmacropublicdep.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(procmacropublicdep.OnResolved(&err));
+
+  Target procmacroprivatedep(
+      setup.settings(),
+      Label(SourceDir("//baz/private/"), "mymacroprivatedep"));
+  procmacroprivatedep.set_output_type(Target::RUST_LIBRARY);
+  procmacroprivatedep.visibility().SetPublic();
+  SourceFile privatebazlib("//baz/private/lib.rs");
+  procmacroprivatedep.sources().push_back(SourceFile("//baz/private/mylib.rs"));
+  procmacroprivatedep.sources().push_back(privatebazlib);
+  procmacroprivatedep.source_types_used().Set(SourceFile::SOURCE_RS);
+  procmacroprivatedep.rust_values().set_crate_root(privatebazlib);
+  procmacroprivatedep.rust_values().crate_name() = "privatedep";
+  procmacroprivatedep.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(procmacroprivatedep.OnResolved(&err));
 
   Target procmacro(setup.settings(), Label(SourceDir("//bar/"), "mymacro"));
   procmacro.set_output_type(Target::RUST_PROC_MACRO);
@@ -754,7 +1236,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, RustProcMacro) {
   procmacro.rust_values().set_crate_type(RustValues::CRATE_PROC_MACRO);
   // Add a dependency to the procmacro so we can be sure its output
   // directory is not propagated downstream beyond the proc macro.
-  procmacro.private_deps().push_back(LabelTargetPair(&procmacrodep));
+  procmacro.public_deps().push_back(LabelTargetPair(&procmacropublicdep));
+  procmacro.private_deps().push_back(LabelTargetPair(&procmacroprivatedep));
   procmacro.SetToolchain(setup.toolchain());
   ASSERT_TRUE(procmacro.OnResolved(&err));
 
@@ -775,9 +1258,16 @@ TEST_F(NinjaRustBinaryTargetWriterTest, RustProcMacro) {
         "target_output_name = libmymacro\n"
         "\n"
         "build obj/bar/libmymacro.so: rust_macro ../../bar/lib.rs | "
-        "../../bar/mylib.rs ../../bar/lib.rs obj/baz/libmymacrodep.rlib\n"
-        "  externs = --extern mymacrodep=obj/baz/libmymacrodep.rlib\n"
-        "  rustdeps = -Ldependency=obj/baz\n"
+        "../../bar/mylib.rs ../../bar/lib.rs "
+        "obj/baz/public/libmymacropublicdep.rlib "
+        "obj/baz/private/libmymacroprivatedep.rlib\n"
+        "  source_file_part = lib.rs\n"
+        "  source_name_part = lib\n"
+        "  externs = "
+        "--extern publicdep=obj/baz/public/libmymacropublicdep.rlib "
+        "--extern privatedep=obj/baz/private/libmymacroprivatedep.rlib\n"
+        "  rustdeps = -Ldependency=obj/baz/public "
+        "-Ldependency=obj/baz/private\n"
         "  ldflags =\n"
         "  sources = ../../bar/mylib.rs ../../bar/lib.rs\n";
     std::string out_str = out.str();
@@ -815,6 +1305,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, RustProcMacro) {
         "\n"
         "build ./foo_bar: rust_bin ../../foo/main.rs | ../../foo/source.rs "
         "../../foo/main.rs obj/bar/libmymacro.so\n"
+        "  source_file_part = main.rs\n"
+        "  source_name_part = main\n"
         "  externs = --extern mymacro=obj/bar/libmymacro.so\n"
         "  rustdeps = -Ldependency=obj/bar\n"
         "  ldflags =\n"
@@ -858,6 +1350,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, GroupDeps) {
         "\n"
         "build obj/bar/libmylib.rlib: rust_rlib ../../bar/lib.rs | "
         "../../bar/mylib.rs ../../bar/lib.rs\n"
+        "  source_file_part = lib.rs\n"
+        "  source_name_part = lib\n"
         "  externs =\n"
         "  rustdeps =\n"
         "  ldflags =\n"
@@ -902,8 +1396,11 @@ TEST_F(NinjaRustBinaryTargetWriterTest, GroupDeps) {
         "target_out_dir = obj/foo\n"
         "target_output_name = bar\n"
         "\n"
-        "build ./foo_bar: rust_bin ../../foo/main.rs | ../../foo/source.rs "
-        "../../foo/main.rs obj/bar/libmylib.rlib || obj/baz/group.stamp\n"
+        "build ./foo_bar: rust_bin ../../foo/main.rs | "
+        "../../foo/source.rs ../../foo/main.rs obj/bar/libmylib.rlib || "
+        "obj/baz/group.stamp\n"
+        "  source_file_part = main.rs\n"
+        "  source_name_part = main\n"
         "  externs = --extern mylib=obj/bar/libmylib.rlib\n"
         "  rustdeps = -Ldependency=obj/bar\n"
         "  ldflags =\n"
@@ -955,6 +1452,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, Externs) {
         "\n"
         "build ./foo_bar: rust_bin ../../foo/main.rs | ../../foo/source.rs "
         "../../foo/main.rs ../../foo/lib1.rlib\n"
+        "  source_file_part = main.rs\n"
+        "  source_name_part = main\n"
         "  externs = --extern lib1=../../foo/lib1.rlib --extern "
         "lib2=lib2.rlib\n"
         "  rustdeps =\n"
@@ -989,7 +1488,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, Inputs) {
     writer.Run();
 
     const char expected[] =
-        "build obj/foo/bar.inputs.stamp: stamp ../../foo/config.json ../../foo/template.h\n"
+        "build obj/foo/bar.inputs.stamp: stamp ../../foo/config.json "
+        "../../foo/template.h\n"
         "crate_name = foo_bar\n"
         "crate_type = bin\n"
         "output_extension = \n"
@@ -1003,6 +1503,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, Inputs) {
         "build ./foo_bar: rust_bin ../../foo/main.rs | ../../foo/source.rs "
         "../../foo/main.rs ../../foo/config.json ../../foo/template.h "
         "|| obj/foo/bar.inputs.stamp\n"
+        "  source_file_part = main.rs\n"
+        "  source_name_part = main\n"
         "  externs =\n"
         "  rustdeps =\n"
         "  ldflags =\n"
@@ -1044,6 +1546,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, CdylibDeps) {
         "\n"
         "build obj/bar/libmylib.so: rust_cdylib ../../bar/lib.rs | "
         "../../bar/lib.rs\n"
+        "  source_file_part = lib.rs\n"
+        "  source_name_part = lib\n"
         "  externs =\n"
         "  rustdeps =\n"
         "  ldflags =\n"
@@ -1082,9 +1586,11 @@ TEST_F(NinjaRustBinaryTargetWriterTest, CdylibDeps) {
         "\n"
         "build ./foo_bar: rust_bin ../../foo/main.rs | ../../foo/source.rs "
         "../../foo/main.rs obj/bar/libmylib.so\n"
+        "  source_file_part = main.rs\n"
+        "  source_name_part = main\n"
         "  externs =\n"
-        "  rustdeps = -Ldependency=obj/bar -Lnative=obj/bar "
-        "-Clink-arg=-Bdynamic -Clink-arg=obj/bar/libmylib.so\n"
+        "  rustdeps = -Lnative=obj/bar -Clink-arg=-Bdynamic "
+        "-Clink-arg=obj/bar/libmylib.so\n"
         "  ldflags =\n"
         "  sources = ../../foo/source.rs ../../foo/main.rs\n";
     std::string out_str = out.str();
@@ -1157,6 +1663,8 @@ TEST_F(NinjaRustBinaryTargetWriterTest, TransitivePublicNonRustDeps) {
         "\n"
         "build ./foo_bar: rust_bin ../../foo/main.rs | ../../foo/main.rs "
         "obj/bar/libmylib.rlib ./libshared.so ./libimplicit.so\n"
+        "  source_file_part = main.rs\n"
+        "  source_name_part = main\n"
         "  externs = --extern mylib=obj/bar/libmylib.rlib\n"
         "  rustdeps = -Ldependency=obj/bar -Lnative=. -Clink-arg=-Bdynamic "
         "-Clink-arg=./libshared.so -Clink-arg=./libimplicit.so\n"
@@ -1166,3 +1674,138 @@ TEST_F(NinjaRustBinaryTargetWriterTest, TransitivePublicNonRustDeps) {
     EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
   }
 }
+
+TEST_F(NinjaRustBinaryTargetWriterTest, TransitiveRustDepsThroughSourceSet) {
+  Err err;
+  TestWithScope setup;
+
+  Target rlib_pub(setup.settings(),
+                  Label(SourceDir("//public/"), "behind_sourceset_public"));
+  rlib_pub.set_output_type(Target::RUST_LIBRARY);
+  rlib_pub.visibility().SetPublic();
+  SourceFile rlib_pub_root("//public/lib.rs");
+  rlib_pub.sources().push_back(
+      SourceFile("//public/behind_sourceset_public.rs"));
+  rlib_pub.sources().push_back(rlib_pub_root);
+  rlib_pub.source_types_used().Set(SourceFile::SOURCE_RS);
+  rlib_pub.rust_values().set_crate_root(rlib_pub_root);
+  rlib_pub.rust_values().crate_name() = "behind_sourceset_public";
+  rlib_pub.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(rlib_pub.OnResolved(&err));
+
+  Target rlib_priv(setup.settings(),
+                  Label(SourceDir("//private/"), "behind_sourceset_private"));
+  rlib_priv.set_output_type(Target::RUST_LIBRARY);
+  rlib_priv.visibility().SetPublic();
+  SourceFile rlib_priv_root("//private/lib.rs");
+  rlib_priv.sources().push_back(
+      SourceFile("//private/behind_sourceset_private.rs"));
+  rlib_priv.sources().push_back(rlib_priv_root);
+  rlib_priv.source_types_used().Set(SourceFile::SOURCE_RS);
+  rlib_priv.rust_values().set_crate_root(rlib_priv_root);
+  rlib_priv.rust_values().crate_name() = "behind_sourceset_private";
+  rlib_priv.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(rlib_priv.OnResolved(&err));
+
+  Target sset(setup.settings(), Label(SourceDir("//sset/"), "bar"));
+  sset.set_output_type(Target::SOURCE_SET);
+  sset.visibility().SetPublic();
+  sset.sources().push_back(SourceFile("//sset/input1.cc"));
+  sset.source_types_used().Set(SourceFile::SOURCE_CPP);
+  sset.SetToolchain(setup.toolchain());
+  sset.public_deps().push_back(LabelTargetPair(&rlib_pub));
+  sset.private_deps().push_back(LabelTargetPair(&rlib_priv));
+  ASSERT_TRUE(sset.OnResolved(&err));
+
+  Target target(setup.settings(), Label(SourceDir("//linked/"), "exe"));
+  target.set_output_type(Target::EXECUTABLE);
+  target.visibility().SetPublic();
+  SourceFile main("//linked/exe.rs");
+  target.sources().push_back(main);
+  target.source_types_used().Set(SourceFile::SOURCE_RS);
+  target.rust_values().set_crate_root(main);
+  target.rust_values().crate_name() = "exe";
+  target.private_deps().push_back(LabelTargetPair(&sset));
+  target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target.OnResolved(&err));
+
+  {
+    std::ostringstream out;
+    NinjaRustBinaryTargetWriter writer(&target, out);
+    writer.Run();
+
+    const char expected[] =
+        "crate_name = exe\n"
+        "crate_type = bin\n"
+        "output_extension = \n"
+        "output_dir = \n"
+        "rustflags =\n"
+        "rustenv =\n"
+        "root_out_dir = .\n"
+        "target_out_dir = obj/linked\n"
+        "target_output_name = exe\n"
+        "\n"
+        "build ./exe: rust_bin ../../linked/exe.rs | ../../linked/exe.rs "
+        "obj/sset/bar.input1.o obj/public/libbehind_sourceset_public.rlib "
+        "obj/private/libbehind_sourceset_private.rlib || obj/sset/bar.stamp\n"
+        "  source_file_part = exe.rs\n"
+        "  source_name_part = exe\n"
+        "  externs = --extern "
+        "behind_sourceset_public=obj/public/libbehind_sourceset_public.rlib\n"
+        "  rustdeps = -Ldependency=obj/public -Ldependency=obj/private "
+        "-Lnative=obj/sset -Clink-arg=-Bdynamic "
+        "-Clink-arg=obj/sset/bar.input1.o\n"
+        "  ldflags =\n"
+        "  sources = ../../linked/exe.rs\n";
+    std::string out_str = out.str();
+    EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+  }
+}
+
+TEST_F(NinjaRustBinaryTargetWriterTest, Pool) {
+  Err err;
+  TestWithScope setup;
+
+  Pool pool(setup.settings(),
+            Label(SourceDir("//foo/"), "pool", setup.toolchain()->label().dir(),
+                  setup.toolchain()->label().name()));
+  pool.set_depth(42);
+
+  Target target(setup.settings(), Label(SourceDir("//foo/"), "bar"));
+  SourceFile main("//foo/source.rs");
+  target.sources().push_back(main);
+  target.source_types_used().Set(SourceFile::SOURCE_RS);
+  target.rust_values().set_crate_root(main);
+  target.rust_values().crate_name() = "bar";
+  target.set_output_type(Target::EXECUTABLE);
+  target.set_pool(LabelPtrPair<Pool>(&pool));
+  target.visibility().SetPublic();
+  target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target.OnResolved(&err));
+
+  std::ostringstream out;
+  NinjaBinaryTargetWriter writer(&target, out);
+  writer.Run();
+
+  const char expected[] =
+      "crate_name = bar\n"
+      "crate_type = bin\n"
+      "output_extension = \n"
+      "output_dir = \n"
+      "rustflags =\n"
+      "rustenv =\n"
+      "root_out_dir = .\n"
+      "target_out_dir = obj/foo\n"
+      "target_output_name = bar\n"
+      "\n"
+      "build ./bar: rust_bin ../../foo/source.rs | ../../foo/source.rs\n"
+      "  source_file_part = source.rs\n"
+      "  source_name_part = source\n"
+      "  externs =\n"
+      "  rustdeps =\n"
+      "  ldflags =\n"
+      "  sources = ../../foo/source.rs\n"
+      "  pool = foo_pool\n";
+  std::string out_str = out.str();
+  EXPECT_EQ(expected, out_str) << expected << "\n" << out_str;
+}
diff --git a/gn/src/gn/ninja_target_command_util.cc b/gn/src/gn/ninja_target_command_util.cc
index b542fb26fdd..a691ae35614 100644
--- a/gn/src/gn/ninja_target_command_util.cc
+++ b/gn/src/gn/ninja_target_command_util.cc
@@ -51,10 +51,13 @@ void WriteOneFlag(RecursiveWriterConfig config,
                   EscapeOptions flag_escape_options,
                   PathOutput& path_output,
                   std::ostream& out,
-                  bool write_substitution) {
+                  bool write_substitution,
+                  bool indent) {
   if (!target->toolchain()->substitution_bits().used.count(subst_enum))
     return;
 
+  if (indent)
+    out << "  ";
   if (write_substitution)
     out << subst_enum->ninja_name << " =";
 
diff --git a/gn/src/gn/ninja_target_command_util.h b/gn/src/gn/ninja_target_command_util.h
index b0179a1cf13..93666fbaa3c 100644
--- a/gn/src/gn/ninja_target_command_util.h
+++ b/gn/src/gn/ninja_target_command_util.h
@@ -102,7 +102,8 @@ void WriteOneFlag(RecursiveWriterConfig config,
                   EscapeOptions flag_escape_options,
                   PathOutput& path_output,
                   std::ostream& out,
-                  bool write_substitution = true);
+                  bool write_substitution = true,
+                  bool indent = false);
 
 // Fills |outputs| with the object or gch file for the precompiled header of the
 // given type (flag type and tool type must match).
diff --git a/gn/src/gn/ninja_target_writer.cc b/gn/src/gn/ninja_target_writer.cc
index efcf9912ef8..0f2514b4f43 100644
--- a/gn/src/gn/ninja_target_writer.cc
+++ b/gn/src/gn/ninja_target_writer.cc
@@ -8,6 +8,7 @@
 
 #include "base/files/file_util.h"
 #include "base/strings/string_util.h"
+#include "gn/c_substitution_type.h"
 #include "gn/config_values_extractors.h"
 #include "gn/err.h"
 #include "gn/escape.h"
@@ -20,8 +21,10 @@
 #include "gn/ninja_create_bundle_target_writer.h"
 #include "gn/ninja_generated_file_target_writer.h"
 #include "gn/ninja_group_target_writer.h"
+#include "gn/ninja_target_command_util.h"
 #include "gn/ninja_utils.h"
 #include "gn/output_file.h"
+#include "gn/rust_substitution_type.h"
 #include "gn/scheduler.h"
 #include "gn/string_output_buffer.h"
 #include "gn/string_utils.h"
@@ -188,6 +191,178 @@ void NinjaTargetWriter::WriteSharedVars(const SubstitutionBits& bits) {
     out_ << std::endl;
 }
 
+void NinjaTargetWriter::WriteCCompilerVars(const SubstitutionBits& bits,
+                                           bool indent,
+                                           bool respect_source_used) {
+  // Defines.
+  if (bits.used.count(&CSubstitutionDefines)) {
+    if (indent)
+      out_ << "  ";
+    out_ << CSubstitutionDefines.ninja_name << " =";
+    RecursiveTargetConfigToStream<std::string>(kRecursiveWriterSkipDuplicates,
+                                               target_, &ConfigValues::defines,
+                                               DefineWriter(), out_);
+    out_ << std::endl;
+  }
+
+  // Framework search path.
+  if (bits.used.count(&CSubstitutionFrameworkDirs)) {
+    const Tool* tool = target_->toolchain()->GetTool(CTool::kCToolLink);
+
+    if (indent)
+      out_ << "  ";
+    out_ << CSubstitutionFrameworkDirs.ninja_name << " =";
+    PathOutput framework_dirs_output(
+        path_output_.current_dir(),
+        settings_->build_settings()->root_path_utf8(), ESCAPE_NINJA_COMMAND);
+    RecursiveTargetConfigToStream<SourceDir>(
+        kRecursiveWriterSkipDuplicates, target_, &ConfigValues::framework_dirs,
+        FrameworkDirsWriter(framework_dirs_output,
+                            tool->framework_dir_switch()),
+        out_);
+    out_ << std::endl;
+  }
+
+  // Include directories.
+  if (bits.used.count(&CSubstitutionIncludeDirs)) {
+    if (indent)
+      out_ << "  ";
+    out_ << CSubstitutionIncludeDirs.ninja_name << " =";
+    PathOutput include_path_output(
+        path_output_.current_dir(),
+        settings_->build_settings()->root_path_utf8(), ESCAPE_NINJA_COMMAND);
+    RecursiveTargetConfigToStream<SourceDir>(
+        kRecursiveWriterSkipDuplicates, target_, &ConfigValues::include_dirs,
+        IncludeWriter(include_path_output), out_);
+    out_ << std::endl;
+  }
+
+  bool has_precompiled_headers =
+      target_->config_values().has_precompiled_headers();
+
+  EscapeOptions opts;
+  opts.mode = ESCAPE_NINJA_COMMAND;
+  if (respect_source_used
+          ? target_->source_types_used().Get(SourceFile::SOURCE_S)
+          : bits.used.count(&CSubstitutionAsmFlags)) {
+    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_,
+                 &CSubstitutionAsmFlags, false, Tool::kToolNone,
+                 &ConfigValues::asmflags, opts, path_output_, out_, true,
+                 indent);
+  }
+  if (respect_source_used
+          ? (target_->source_types_used().Get(SourceFile::SOURCE_C) ||
+             target_->source_types_used().Get(SourceFile::SOURCE_CPP) ||
+             target_->source_types_used().Get(SourceFile::SOURCE_M) ||
+             target_->source_types_used().Get(SourceFile::SOURCE_MM) ||
+             target_->source_types_used().Get(SourceFile::SOURCE_MODULEMAP))
+          : bits.used.count(&CSubstitutionCFlags)) {
+    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_, &CSubstitutionCFlags,
+                 false, Tool::kToolNone, &ConfigValues::cflags, opts,
+                 path_output_, out_, true, indent);
+  }
+  if (respect_source_used
+          ? target_->source_types_used().Get(SourceFile::SOURCE_C)
+          : bits.used.count(&CSubstitutionCFlagsC)) {
+    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_, &CSubstitutionCFlagsC,
+                 has_precompiled_headers, CTool::kCToolCc,
+                 &ConfigValues::cflags_c, opts, path_output_, out_, true,
+                 indent);
+  }
+  if (respect_source_used
+          ? (target_->source_types_used().Get(SourceFile::SOURCE_CPP) ||
+             target_->source_types_used().Get(SourceFile::SOURCE_MODULEMAP))
+          : bits.used.count(&CSubstitutionCFlagsCc)) {
+    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_,
+                 &CSubstitutionCFlagsCc, has_precompiled_headers,
+                 CTool::kCToolCxx, &ConfigValues::cflags_cc, opts, path_output_,
+                 out_, true, indent);
+  }
+  if (respect_source_used
+          ? target_->source_types_used().Get(SourceFile::SOURCE_M)
+          : bits.used.count(&CSubstitutionCFlagsObjC)) {
+    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_,
+                 &CSubstitutionCFlagsObjC, has_precompiled_headers,
+                 CTool::kCToolObjC, &ConfigValues::cflags_objc, opts,
+                 path_output_, out_, true, indent);
+  }
+  if (respect_source_used
+          ? target_->source_types_used().Get(SourceFile::SOURCE_MM)
+          : bits.used.count(&CSubstitutionCFlagsObjCc)) {
+    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_,
+                 &CSubstitutionCFlagsObjCc, has_precompiled_headers,
+                 CTool::kCToolObjCxx, &ConfigValues::cflags_objcc, opts,
+                 path_output_, out_, true, indent);
+  }
+  if (target_->source_types_used().SwiftSourceUsed() || !respect_source_used) {
+    if (bits.used.count(&CSubstitutionSwiftModuleName)) {
+      if (indent)
+        out_ << "  ";
+      out_ << CSubstitutionSwiftModuleName.ninja_name << " = ";
+      EscapeStringToStream(out_, target_->swift_values().module_name(), opts);
+      out_ << std::endl;
+    }
+
+    if (bits.used.count(&CSubstitutionSwiftBridgeHeader)) {
+      if (indent)
+        out_ << "  ";
+      out_ << CSubstitutionSwiftBridgeHeader.ninja_name << " = ";
+      if (!target_->swift_values().bridge_header().is_null()) {
+        path_output_.WriteFile(out_, target_->swift_values().bridge_header());
+      } else {
+        out_ << R"("")";
+      }
+      out_ << std::endl;
+    }
+
+    if (bits.used.count(&CSubstitutionSwiftModuleDirs)) {
+      // Uniquify the list of swiftmodule dirs (in case multiple swiftmodules
+      // are generated in the same directory).
+      UniqueVector<SourceDir> swiftmodule_dirs;
+      for (const Target* dep : target_->swift_values().modules())
+        swiftmodule_dirs.push_back(dep->swift_values().module_output_dir());
+
+      if (indent)
+        out_ << "  ";
+      out_ << CSubstitutionSwiftModuleDirs.ninja_name << " =";
+      PathOutput swiftmodule_path_output(
+          path_output_.current_dir(),
+          settings_->build_settings()->root_path_utf8(), ESCAPE_NINJA_COMMAND);
+      IncludeWriter swiftmodule_path_writer(swiftmodule_path_output);
+      for (const SourceDir& swiftmodule_dir : swiftmodule_dirs) {
+        swiftmodule_path_writer(swiftmodule_dir, out_);
+      }
+      out_ << std::endl;
+    }
+
+    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_,
+                 &CSubstitutionSwiftFlags, false, CTool::kCToolSwift,
+                 &ConfigValues::swiftflags, opts, path_output_, out_, true,
+                 indent);
+  }
+}
+
+void NinjaTargetWriter::WriteRustCompilerVars(const SubstitutionBits& bits,
+                                              bool indent,
+                                              bool always_write) {
+  EscapeOptions opts;
+  opts.mode = ESCAPE_NINJA_COMMAND;
+
+  if (bits.used.count(&kRustSubstitutionRustFlags) || always_write) {
+    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_,
+                 &kRustSubstitutionRustFlags, false, Tool::kToolNone,
+                 &ConfigValues::rustflags, opts, path_output_, out_, true,
+                 indent);
+  }
+
+  if (bits.used.count(&kRustSubstitutionRustEnv) || always_write) {
+    WriteOneFlag(kRecursiveWriterKeepDuplicates, target_,
+                 &kRustSubstitutionRustEnv, false, Tool::kToolNone,
+                 &ConfigValues::rustenv, opts, path_output_, out_, true,
+                 indent);
+  }
+}
+
 std::vector<OutputFile> NinjaTargetWriter::WriteInputDepsStampAndGetDep(
     const std::vector<const Target*>& additional_hard_deps,
     size_t num_stamp_uses) const {
diff --git a/gn/src/gn/ninja_target_writer.h b/gn/src/gn/ninja_target_writer.h
index 7a339ab5e82..3d38a14f584 100644
--- a/gn/src/gn/ninja_target_writer.h
+++ b/gn/src/gn/ninja_target_writer.h
@@ -39,6 +39,23 @@ class NinjaTargetWriter {
   // identified by the given bits will be written.
   void WriteSharedVars(const SubstitutionBits& bits);
 
+  // Writes out the substitution values that are shared between C compiler tools
+  // and action tools. Only the substitutions identified by the given bits will
+  // be written.
+  // If respect_source_used is set, the generated substitution values will
+  // respect the types of source code used; otherwise they will respect the bits
+  // passed in.
+  void WriteCCompilerVars(const SubstitutionBits& bits,
+                          bool indent,
+                          bool respect_source_used);
+
+  // Writes out the substitution values that are shared between Rust tools
+  // and action tools. Only the substitutions identified by the given bits will
+  // be written, unless 'always_write' is specified.
+  void WriteRustCompilerVars(const SubstitutionBits& bits,
+                             bool indent,
+                             bool always_write);
+
   // Writes to the output stream a stamp rule for input dependencies, and
   // returns the file to be appended to source rules that encodes the
   // order-only dependencies for the current target.
diff --git a/gn/src/gn/ninja_toolchain_writer.cc b/gn/src/gn/ninja_toolchain_writer.cc
index 7be771932c7..2314bae5d3d 100644
--- a/gn/src/gn/ninja_toolchain_writer.cc
+++ b/gn/src/gn/ninja_toolchain_writer.cc
@@ -9,6 +9,7 @@
 #include "base/files/file_util.h"
 #include "base/strings/stringize_macros.h"
 #include "gn/build_settings.h"
+#include "gn/builtin_tool.h"
 #include "gn/c_tool.h"
 #include "gn/filesystem_utils.h"
 #include "gn/general_tool.h"
@@ -43,8 +44,10 @@ void NinjaToolchainWriter::Run(
   std::string rule_prefix = GetNinjaRulePrefixForToolchain(settings_);
 
   for (const auto& tool : toolchain_->tools()) {
-    if (tool.second->name() == GeneralTool::kGeneralToolAction)
+    if (tool.second->name() == GeneralTool::kGeneralToolAction ||
+        tool.second->AsBuiltin()) {
       continue;
+    }
     WriteToolRule(tool.second.get(), rule_prefix);
   }
   out_ << std::endl;
diff --git a/gn/src/gn/parse_tree.cc b/gn/src/gn/parse_tree.cc
index e9ca8fa6671..28d5313483b 100644
--- a/gn/src/gn/parse_tree.cc
+++ b/gn/src/gn/parse_tree.cc
@@ -258,10 +258,12 @@ void ParseNode::AddCommentsJSONNodes(base::Value* out_value) const {
 std::unique_ptr<ParseNode> ParseNode::BuildFromJSON(const base::Value& value) {
   const std::string& str_type = value.FindKey(kJsonNodeType)->GetString();
 
-#define RETURN_IF_MATCHES_NAME(t)     \
-  if (str_type == t::kDumpNodeName) { \
-    return t::NewFromJSON(value);     \
-  }
+#define RETURN_IF_MATCHES_NAME(t)               \
+  do {                                          \
+    if (str_type == t::kDumpNodeName) {         \
+      return t::NewFromJSON(value);             \
+    }                                           \
+  } while(0)
 
   RETURN_IF_MATCHES_NAME(AccessorNode);
   RETURN_IF_MATCHES_NAME(BinaryOpNode);
@@ -332,7 +334,8 @@ base::Value AccessorNode::GetJSONNode() const {
   const base::Value* child = value.FindKey(kJsonNodeChild); \
   if (!child || !child->is_list()) {                        \
     return nullptr;                                         \
-  }
+  }                                                         \
+  (void)(0) // this is to supress extra semicolon warning.
 
 // static
 std::unique_ptr<AccessorNode> AccessorNode::NewFromJSON(
diff --git a/gn/src/gn/parser.cc b/gn/src/gn/parser.cc
index a4ad2446dd9..96739a5a51a 100644
--- a/gn/src/gn/parser.cc
+++ b/gn/src/gn/parser.cc
@@ -181,19 +181,20 @@ Scopes
 
   All execution happens in the context of a scope which holds the current state
   (like variables). With the exception of loops and conditions, '{' introduces
-  a new scope that has a parent reference to the old scope.
+  a new scope.
 
-  Variable reads recursively search all nested scopes until the variable is
-  found or there are no more scopes. Variable writes always go into the current
-  scope. This means that after the closing '}' (again excepting loops and
-  conditions), all local variables will be restored to the previous values.
-  This also means that "foo = foo" can do useful work by copying a variable
-  into the current scope that was defined in a containing scope.
+  Most scopes have a parent reference to the old scope. Variable reads
+  recursively search all parent scopes until the variable is found or there are
+  no more scopes. Variable writes always go into the current scope. This means
+  that after the closing '}' (again excepting loops and conditions), all local
+  variables will be restored to the previous values.  This also means that "foo
+  = foo" can do useful work by copying a variable into the current scope that
+  was defined in a containing scope.
 
-  Scopes can also be assigned to variables. Such scopes can be created by
-  functions like exec_script, when invoking a template (the template code
-  refers to the variables set by the invoking code by the implicitly-created
-  "invoker" scope), or explicitly like:
+  Scopes can be assigned to variables. Examples of such scopes are the
+  implicitly-created "invoker" when invoking a template (which refers to the
+  variables set by the invoking code), scopes created by functions like
+  exec_script, and scopes explicitly created like
 
     empty_scope = {}
     myvalues = {
@@ -201,10 +202,14 @@ Scopes
       bar = "something"
     }
 
-  Inside such a scope definition can be any GN code including conditionals and
-  function calls. After the close of the scope, it will contain all variables
-  explicitly set by the code contained inside it. After this, the values can be
-  read, modified, or added to:
+  In the case of explicitly created scopes and scopes created by functions like
+  exec_script, there is no reference to the parent scope. Such scopes are fully
+  self-contained and do not "inherit" values from their defining scope.
+
+  Inside an explicit scope definition can be any GN code including conditionals
+  and function calls. After the close of the scope, it will contain all
+  variables explicitly set by the code contained inside it. After this, the
+  values can be read, modified, or added to:
 
     myvalues.foo += 2
     empty_scope.new_thing = [ 1, 2, 3 ]
diff --git a/gn/src/gn/pointer_set.h b/gn/src/gn/pointer_set.h
index 6dc18b4c509..2bec930b04a 100644
--- a/gn/src/gn/pointer_set.h
+++ b/gn/src/gn/pointer_set.h
@@ -6,6 +6,8 @@
 #define SRC_GN_POINTER_SET_H_
 
 #include <functional>
+#include <vector>
+
 #include "gn/hash_table_base.h"
 
 // PointerSet<T> is a fast implemention of a set of non-owning and non-null
@@ -187,6 +189,16 @@ class PointerSet : public HashTableBase<PointerSetNode> {
     return true;
   }
 
+  // Convert this to a vector, more convenient and slightly faster than using
+  // std::vector<T*>(set.begin(), set.end()).
+  std::vector<T*> ToVector() const {
+    std::vector<T*> result(this->size());
+    auto it_result = result.begin();
+    for (auto it = this->begin(); it.valid(); ++it)
+      *it_result++ = *it;
+    return result;
+  }
+
  private:
   // Lookup node matching a given pointer. If result->valid() is true
   // then the pointer was found, otherwise, this is the location of
diff --git a/gn/src/gn/pointer_set_unittest.cc b/gn/src/gn/pointer_set_unittest.cc
index 0bb4d6a81e8..e71a97d7107 100644
--- a/gn/src/gn/pointer_set_unittest.cc
+++ b/gn/src/gn/pointer_set_unittest.cc
@@ -5,6 +5,8 @@
 #include "gn/pointer_set.h"
 #include "util/test/test.h"
 
+#include <algorithm>
+
 struct Foo {
   int x;
 };
@@ -165,3 +167,15 @@ TEST(PointerSet, IntersectionWith) {
   EXPECT_EQ(set1, set);
   EXPECT_EQ(set2, set);
 }
+
+TEST(PointerSet, ToVector) {
+  TestPointerSet set(kFullList.begin(), kFullList.end());
+  auto vector = set.ToVector();
+  EXPECT_EQ(vector.size(), kFullList.size());
+
+  // NOTE: Order of items in the result is not guaranteed
+  // so just check whether items are available in it.
+  EXPECT_NE(std::find(vector.begin(), vector.end(), kFoo1), vector.end());
+  EXPECT_NE(std::find(vector.begin(), vector.end(), kFoo2), vector.end());
+  EXPECT_NE(std::find(vector.begin(), vector.end(), kFoo3), vector.end());
+}
+\ No newline at end of file
diff --git a/gn/src/gn/resolved_target_deps.h b/gn/src/gn/resolved_target_deps.h
new file mode 100644
index 00000000000..57e961f656b
--- /dev/null
+++ b/gn/src/gn/resolved_target_deps.h
@@ -0,0 +1,90 @@
+// Copyright 2022 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef TOOLS_GN_RESOLVED_TARGET_DEPS_H_
+#define TOOLS_GN_RESOLVED_TARGET_DEPS_H_
+
+#include "base/containers/span.h"
+#include "gn/label_ptr.h"
+
+#include <memory>
+
+// A class used to record the dependencies of a given Target in
+// a way that is much more efficient to iterate over than having three
+// separate LabelTargetVector instances. Technically equivalent to
+// DepsIterator, but profiling shows that this class is much faster
+// to use during graph-traversal heavy operations.
+//
+// Usage is:
+//   1) Create instance, passing const references to the LabelTargetVector
+//      instances for the private, public and data deps for the target.
+//
+//   2) Use private_deps(), public_deps(), data_deps(), linked_deps()
+//      and all_deps() to retrieve spans that cover various subsets of
+//      interests. These can be used directly in for-range loops as in:
+//
+//       for (const Target* target : resolved.linked_deps()) {
+//         ..
+//       }
+//
+class ResolvedTargetDeps {
+ public:
+  ResolvedTargetDeps() = default;
+
+  ResolvedTargetDeps(const LabelTargetVector& public_deps,
+                     const LabelTargetVector& private_deps,
+                     const LabelTargetVector& data_deps)
+      : public_count_(static_cast<uint32_t>(public_deps.size())),
+        private_count_(static_cast<uint32_t>(private_deps.size())),
+        data_count_(static_cast<uint32_t>(data_deps.size())),
+        deps_(Allocate(public_deps, private_deps, data_deps)) {}
+
+  size_t size() const { return private_count_ + public_count_ + data_count_; }
+
+  base::span<const Target*> public_deps() const {
+    return {deps_.get(), public_count_};
+  }
+
+  base::span<const Target*> private_deps() const {
+    return {deps_.get() + public_count_, private_count_};
+  }
+
+  base::span<const Target*> data_deps() const {
+    return {deps_.get() + private_count_ + public_count_, data_count_};
+  }
+
+  base::span<const Target*> linked_deps() const {
+    return {deps_.get(), private_count_ + public_count_};
+  }
+
+  base::span<const Target*> all_deps() const {
+    return {deps_.get(), private_count_ + public_count_ + data_count_};
+  }
+
+  static std::unique_ptr<const Target*[]> Allocate(
+      const LabelTargetVector& public_deps,
+      const LabelTargetVector& private_deps,
+      const LabelTargetVector& data_deps) {
+    size_t total_size =
+        private_deps.size() + public_deps.size() + data_deps.size();
+    auto result = std::make_unique<const Target*[]>(total_size);
+    const Target** ptr = result.get();
+    for (const auto& pair : public_deps)
+      *ptr++ = pair.ptr;
+    for (const auto& pair : private_deps)
+      *ptr++ = pair.ptr;
+    for (const auto& pair : data_deps)
+      *ptr++ = pair.ptr;
+    return result;
+  }
+
+ private:
+  uint32_t public_count_ = 0;
+  uint32_t private_count_ = 0;
+  uint32_t data_count_ = 0;
+  // Store the pointers in the following order: public, private, data.
+  std::unique_ptr<const Target*[]> deps_;
+};
+
+#endif  // TOOLS_GN_RESOLVED_TARGET_DEPS_H_
diff --git a/gn/src/gn/resolved_target_deps_unittest.cc b/gn/src/gn/resolved_target_deps_unittest.cc
new file mode 100644
index 00000000000..74d623d091d
--- /dev/null
+++ b/gn/src/gn/resolved_target_deps_unittest.cc
@@ -0,0 +1,63 @@
+// Copyright 2022 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "gn/resolved_target_deps.h"
+#include "gn/test_with_scope.h"
+#include "util/test/test.h"
+
+TEST(ResolvedTargetDeps, DefaultConstruction) {
+  ResolvedTargetDeps deps;
+  EXPECT_EQ(0u, deps.size());
+  EXPECT_TRUE(deps.public_deps().empty());
+  EXPECT_TRUE(deps.private_deps().empty());
+  EXPECT_TRUE(deps.data_deps().empty());
+  EXPECT_TRUE(deps.linked_deps().empty());
+  EXPECT_TRUE(deps.all_deps().empty());
+}
+
+TEST(ResolvedTargetDeps, Construction) {
+  TestWithScope setup;
+  TestTarget a(setup, "//foo:a", Target::STATIC_LIBRARY);
+  TestTarget b(setup, "//foo:b", Target::SOURCE_SET);
+  TestTarget c(setup, "//foo:c", Target::SOURCE_SET);
+  TestTarget d(setup, "//foo:d", Target::SOURCE_SET);
+  TestTarget e(setup, "//foo:e", Target::EXECUTABLE);
+
+  LabelTargetVector public_vec;
+  LabelTargetVector private_vec;
+  LabelTargetVector data_vec;
+
+  public_vec.emplace_back(&a);
+  public_vec.emplace_back(&b);
+  private_vec.emplace_back(&c);
+  private_vec.emplace_back(&d);
+  data_vec.emplace_back(&e);
+
+  ResolvedTargetDeps deps(public_vec, private_vec, data_vec);
+  EXPECT_EQ(5u, deps.size());
+
+  EXPECT_EQ(2u, deps.public_deps().size());
+  EXPECT_EQ(&a, deps.public_deps()[0]);
+  EXPECT_EQ(&b, deps.public_deps()[1]);
+
+  EXPECT_EQ(2u, deps.private_deps().size());
+  EXPECT_EQ(&c, deps.private_deps()[0]);
+  EXPECT_EQ(&d, deps.private_deps()[1]);
+
+  EXPECT_EQ(1u, deps.data_deps().size());
+  EXPECT_EQ(&e, deps.data_deps()[0]);
+
+  EXPECT_EQ(4u, deps.linked_deps().size());
+  EXPECT_EQ(&a, deps.linked_deps()[0]);
+  EXPECT_EQ(&b, deps.linked_deps()[1]);
+  EXPECT_EQ(&c, deps.linked_deps()[2]);
+  EXPECT_EQ(&d, deps.linked_deps()[3]);
+
+  EXPECT_EQ(5u, deps.all_deps().size());
+  EXPECT_EQ(&a, deps.all_deps()[0]);
+  EXPECT_EQ(&b, deps.all_deps()[1]);
+  EXPECT_EQ(&c, deps.all_deps()[2]);
+  EXPECT_EQ(&d, deps.all_deps()[3]);
+  EXPECT_EQ(&e, deps.all_deps()[4]);
+}
diff --git a/gn/src/gn/runtime_deps.cc b/gn/src/gn/runtime_deps.cc
index 25eb2efd695..9ca016d9a29 100644
--- a/gn/src/gn/runtime_deps.cc
+++ b/gn/src/gn/runtime_deps.cc
@@ -133,7 +133,7 @@ bool CollectRuntimeDepsFromFlag(const BuildSettings* build_settings,
                                 RuntimeDepsVector* files_to_write,
                                 Err* err) {
   std::string deps_target_list_file =
-      base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+      base::CommandLine::ForCurrentProcess()->GetSwitchValueString(
           switches::kRuntimeDepsListFile);
 
   if (deps_target_list_file.empty())
diff --git a/gn/src/gn/rust_project_writer.cc b/gn/src/gn/rust_project_writer.cc
index c11f967b087..8bcd4950973 100644
--- a/gn/src/gn/rust_project_writer.cc
+++ b/gn/src/gn/rust_project_writer.cc
@@ -10,6 +10,7 @@
 #include <tuple>
 
 #include "base/json/string_escape.h"
+#include "base/strings/string_split.h"
 #include "gn/builder.h"
 #include "gn/deps_iterator.h"
 #include "gn/ninja_target_command_util.h"
@@ -28,9 +29,7 @@
 // Current structure of rust-project.json output file
 //
 // {
-//    "roots": [
-//      "some/source/root"  // each crate's source root
-//    ],
+//    "sysroot": "path/to/rust/sysroot",
 //    "crates": [
 //        {
 //            "deps": [
@@ -39,7 +38,14 @@
 //                    "name": "alloc" // extern name of dependency
 //                },
 //            ],
-//            "edition": "2018", // edition of crate
+//            "source": [
+//                "include_dirs": [
+//                     "some/source/root",
+//                     "some/gen/dir",
+//                ],
+//                "exclude_dirs": []
+//            },
+//            "edition": "2021", // edition of crate
 //            "cfg": [
 //              "unix", // "atomic" value config options
 //              "rust_panic=\"abort\""", // key="value" config options
@@ -156,99 +162,9 @@ std::vector<std::string> FindAllArgValuesAfterPrefix(
   return values;
 }
 
-// TODO(bwb) Parse sysroot structure from toml files. This is fragile and
-// might break if upstream changes the dependency structure.
-const std::string_view sysroot_crates[] = {"std",
-                                           "core",
-                                           "alloc",
-                                           "panic_unwind",
-                                           "proc_macro",
-                                           "test",
-                                           "panic_abort",
-                                           "unwind"};
-
-// Multiple sysroot crates have dependenices on each other.  This provides a
-// mechanism for specifying that in an extendible manner.
-const std::unordered_map<std::string_view, std::vector<std::string_view>>
-    sysroot_deps_map = {{"alloc", {"core"}},
-                        {"std", {"alloc", "core", "panic_abort", "unwind"}}};
-
-// Add each of the crates a sysroot has, including their dependencies.
-void AddSysrootCrate(const BuildSettings* build_settings,
-                     std::string_view crate,
-                     std::string_view current_sysroot,
-                     SysrootCrateIndexMap& sysroot_crate_lookup,
-                     CrateList& crate_list) {
-  if (sysroot_crate_lookup.find(crate) != sysroot_crate_lookup.end()) {
-    // If this sysroot crate is already in the lookup, we don't add it again.
-    return;
-  }
-
-  // Add any crates that this sysroot crate depends on.
-  auto deps_lookup = sysroot_deps_map.find(crate);
-  if (deps_lookup != sysroot_deps_map.end()) {
-    auto deps = (*deps_lookup).second;
-    for (auto dep : deps) {
-      AddSysrootCrate(build_settings, dep, current_sysroot,
-                      sysroot_crate_lookup, crate_list);
-    }
-  }
-
-  size_t crate_index = crate_list.size();
-  sysroot_crate_lookup.insert(std::make_pair(crate, crate_index));
-
-  base::FilePath rebased_out_dir =
-      build_settings->GetFullPath(build_settings->build_dir());
-  auto crate_path =
-      FilePathToUTF8(rebased_out_dir) + std::string(current_sysroot) +
-      "/lib/rustlib/src/rust/library/" + std::string(crate) + "/src/lib.rs";
-
-  Crate sysroot_crate =
-      Crate(SourceFile(crate_path), crate_index, std::string(crate), "2018");
-
-  sysroot_crate.AddConfigItem("debug_assertions");
-
-  if (deps_lookup != sysroot_deps_map.end()) {
-    auto deps = (*deps_lookup).second;
-    for (auto dep : deps) {
-      auto idx = sysroot_crate_lookup[dep];
-      sysroot_crate.AddDependency(idx, std::string(dep));
-    }
-  }
-
-  crate_list.push_back(sysroot_crate);
-}
-
-// Add the given sysroot to the project, if it hasn't already been added.
-void AddSysroot(const BuildSettings* build_settings,
-                std::string_view sysroot,
-                SysrootIndexMap& sysroot_lookup,
-                CrateList& crate_list) {
-  // If this sysroot is already in the lookup, we don't add it again.
-  if (sysroot_lookup.find(sysroot) != sysroot_lookup.end()) {
-    return;
-  }
-
-  // Otherwise, add all of its crates
-  for (auto crate : sysroot_crates) {
-    AddSysrootCrate(build_settings, crate, sysroot, sysroot_lookup[sysroot],
-                    crate_list);
-  }
-}
-
-void AddSysrootDependencyToCrate(Crate* crate,
-                                 const SysrootCrateIndexMap& sysroot,
-                                 std::string_view crate_name) {
-  if (const auto crate_idx = sysroot.find(crate_name);
-      crate_idx != sysroot.end()) {
-    crate->AddDependency(crate_idx->second, std::string(crate_name));
-  }
-}
-
 void AddTarget(const BuildSettings* build_settings,
                const Target* target,
                TargetIndexMap& lookup,
-               SysrootIndexMap& sysroot_lookup,
                CrateList& crate_list) {
   if (lookup.find(target) != lookup.end()) {
     // If target is already in the lookup, we don't add it again.
@@ -257,21 +173,11 @@ void AddTarget(const BuildSettings* build_settings,
 
   auto compiler_args = ExtractCompilerArgs(target);
   auto compiler_target = FindArgValue("--target", compiler_args);
-
-  // Check what sysroot this target needs.  Add it to the crate list if it
-  // hasn't already been added.
-  auto rust_tool =
-      target->toolchain()->GetToolForTargetFinalOutputAsRust(target);
-  auto current_sysroot = rust_tool->GetSysroot();
-  if (current_sysroot != "" && sysroot_lookup.count(current_sysroot) == 0) {
-    AddSysroot(build_settings, current_sysroot, sysroot_lookup, crate_list);
-  }
-
   auto crate_deps = GetRustDeps(target);
 
   // Add all dependencies of this crate, before this crate.
   for (const auto& dep : crate_deps) {
-    AddTarget(build_settings, dep, lookup, sysroot_lookup, crate_list);
+    AddTarget(build_settings, dep, lookup, crate_list);
   }
 
   // The index of a crate is its position (0-based) in the list of crates.
@@ -289,8 +195,10 @@ void AddTarget(const BuildSettings* build_settings,
     edition = FindArgValue("--edition", compiler_args);
   }
 
-  Crate crate =
-      Crate(crate_root, crate_id, crate_label, edition.value_or("2015"));
+  auto gen_dir = GetBuildDirForTargetAsOutputFile(target, BuildDirType::GEN);
+
+  Crate crate = Crate(crate_root, gen_dir, crate_id, crate_label,
+                      edition.value_or("2015"));
 
   crate.SetCompilerArgs(compiler_args);
   if (compiler_target.has_value())
@@ -306,17 +214,25 @@ void AddTarget(const BuildSettings* build_settings,
     crate.AddConfigItem(cfg);
   }
 
-  // Add the sysroot dependencies, if there is one.
-  if (current_sysroot != "") {
-    const auto& sysroot = sysroot_lookup[current_sysroot];
-    AddSysrootDependencyToCrate(&crate, sysroot, "core");
-    AddSysrootDependencyToCrate(&crate, sysroot, "alloc");
-    AddSysrootDependencyToCrate(&crate, sysroot, "std");
-
-    // Proc macros have the proc_macro crate as a direct dependency
-    if (std::string_view(rust_tool->name()) ==
-        std::string_view(RustTool::kRsToolMacro)) {
-      AddSysrootDependencyToCrate(&crate, sysroot, "proc_macro");
+  // If it's a proc macro, record its output location so IDEs can invoke it.
+  auto rust_tool =
+      target->toolchain()->GetToolForTargetFinalOutputAsRust(target);
+  if (std::string_view(rust_tool->name()) ==
+      std::string_view(RustTool::kRsToolMacro)) {
+    auto outputs = target->computed_outputs();
+    if (outputs.size() > 0) {
+      crate.SetIsProcMacro(outputs[0]);
+    }
+  }
+
+  // Note any environment variables. These may be used by proc macros
+  // invoked by the current crate (so we want to record these for all crates,
+  // not just proc macro crates)
+  for (const auto& env_var : target->config_values().rustenv()) {
+    std::vector<std::string> parts = base::SplitString(
+        env_var, "=", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
+    if (parts.size() >= 2) {
+      crate.AddRustenv(parts[0], parts[1]);
     }
   }
 
@@ -331,25 +247,21 @@ void AddTarget(const BuildSettings* build_settings,
 
 void WriteCrates(const BuildSettings* build_settings,
                  CrateList& crate_list,
+                 std::optional<std::string>& sysroot,
                  std::ostream& rust_project) {
-  // produce a de-duplicated set of source roots:
-  std::set<std::string> roots;
-  for (auto& crate : crate_list) {
-    roots.insert(
-        FilePathToUTF8(build_settings->GetFullPath(crate.root().GetDir())));
-  }
-
   rust_project << "{" NEWLINE;
-  rust_project << "  \"roots\": [";
-  bool first_root = true;
-  for (auto& root : roots) {
-    if (!first_root)
-      rust_project << ",";
-    first_root = false;
 
-    rust_project << NEWLINE "    \"" << root << "\"";
+  // If a sysroot was found, then that can be used to tell rust-analyzer where
+  // to find the sysroot (and associated tools like the
+  // 'rust-analyzer-proc-macro-srv` proc-macro server that matches the abi used
+  // by 'rustc'
+  if (sysroot.has_value()) {
+    base::FilePath rebased_out_dir =
+        build_settings->GetFullPath(build_settings->build_dir());
+    auto sysroot_path = FilePathToUTF8(rebased_out_dir) + sysroot.value();
+    rust_project << "  \"sysroot\": \"" << sysroot_path << "\"," NEWLINE;
   }
-  rust_project << NEWLINE "  ]," NEWLINE;
+
   rust_project << "  \"crates\": [";
   bool first_crate = true;
   for (auto& crate : crate_list) {
@@ -363,7 +275,25 @@ void WriteCrates(const BuildSettings* build_settings,
     rust_project << NEWLINE << "    {" NEWLINE
                  << "      \"crate_id\": " << crate.index() << "," NEWLINE
                  << "      \"root_module\": \"" << crate_module << "\"," NEWLINE
-                 << "      \"label\": \"" << crate.label() << "\"," NEWLINE;
+                 << "      \"label\": \"" << crate.label() << "\"," NEWLINE
+                 << "      \"source\": {" NEWLINE
+                 << "          \"include_dirs\": [" NEWLINE
+                 << "               \""
+                 << FilePathToUTF8(
+                        build_settings->GetFullPath(crate.root().GetDir()))
+                 << "\"";
+    auto gen_dir = crate.gen_dir();
+    if (gen_dir.has_value()) {
+      auto gen_dir_path = FilePathToUTF8(
+          build_settings->GetFullPath(gen_dir->AsSourceDir(build_settings)));
+      rust_project << "," NEWLINE << "               \"" << gen_dir_path
+                   << "\"" NEWLINE;
+    } else {
+      rust_project << NEWLINE;
+    }
+    rust_project << "          ]," NEWLINE
+                 << "          \"exclude_dirs\": []" NEWLINE
+                 << "      }," NEWLINE;
 
     auto compiler_target = crate.CompilerTarget();
     if (compiler_target.has_value()) {
@@ -404,6 +334,15 @@ void WriteCrates(const BuildSettings* build_settings,
 
     rust_project << "      \"edition\": \"" << crate.edition() << "\"," NEWLINE;
 
+    auto proc_macro_target = crate.proc_macro_path();
+    if (proc_macro_target.has_value()) {
+      rust_project << "      \"is_proc_macro\": true," NEWLINE;
+      auto so_location = FilePathToUTF8(build_settings->GetFullPath(
+          proc_macro_target->AsSourceFile(build_settings)));
+      rust_project << "      \"proc_macro_dylib_path\": \"" << so_location
+                   << "\"," NEWLINE;
+    }
+
     rust_project << "      \"cfg\": [";
     bool first_cfg = true;
     for (const auto& cfg : crate.configs()) {
@@ -418,8 +357,29 @@ void WriteCrates(const BuildSettings* build_settings,
       rust_project << "        \"" << escaped_config << "\"";
     }
     rust_project << NEWLINE;
-    rust_project << "      ]" NEWLINE;  // end cfgs
+    rust_project << "      ]";  // end cfgs
+
+    if (!crate.rustenv().empty()) {
+      rust_project << "," NEWLINE;
+      rust_project << "      \"env\": {";
+      bool first_env = true;
+      for (const auto& env : crate.rustenv()) {
+        if (!first_env)
+          rust_project << ",";
+        first_env = false;
+        std::string escaped_key, escaped_val;
+        base::EscapeJSONString(env.first, false, &escaped_key);
+        base::EscapeJSONString(env.second, false, &escaped_val);
+        rust_project << NEWLINE;
+        rust_project << "        \"" << escaped_key << "\": \"" << escaped_val
+                     << "\"";
+      }
 
+      rust_project << NEWLINE;
+      rust_project << "      }" NEWLINE;  // end env vars
+    } else {
+      rust_project << NEWLINE;
+    }
     rust_project << "    }";  // end crate
   }
   rust_project << NEWLINE "  ]" NEWLINE;  // end crate list
@@ -430,16 +390,25 @@ void RustProjectWriter::RenderJSON(const BuildSettings* build_settings,
                                    std::vector<const Target*>& all_targets,
                                    std::ostream& rust_project) {
   TargetIndexMap lookup;
-  SysrootIndexMap sysroot_lookup;
   CrateList crate_list;
+  std::optional<std::string> rust_sysroot;
 
   // All the crates defined in the project.
   for (const auto* target : all_targets) {
     if (!target->IsBinary() || !target->source_types_used().RustSourceUsed())
       continue;
 
-    AddTarget(build_settings, target, lookup, sysroot_lookup, crate_list);
+    AddTarget(build_settings, target, lookup, crate_list);
+
+    // If a sysroot hasn't been found, see if we can find one using this target.
+    if (!rust_sysroot.has_value()) {
+      auto rust_tool =
+          target->toolchain()->GetToolForTargetFinalOutputAsRust(target);
+      auto sysroot = rust_tool->GetSysroot();
+      if (sysroot != "")
+        rust_sysroot = sysroot;
+    }
   }
 
-  WriteCrates(build_settings, crate_list, rust_project);
+  WriteCrates(build_settings, crate_list, rust_sysroot, rust_project);
 }
diff --git a/gn/src/gn/rust_project_writer_helpers.h b/gn/src/gn/rust_project_writer_helpers.h
index a63ded1f520..31efd403f03 100644
--- a/gn/src/gn/rust_project_writer_helpers.h
+++ b/gn/src/gn/rust_project_writer_helpers.h
@@ -14,6 +14,7 @@
 #include <unordered_map>
 #include <vector>
 
+#include "base/containers/flat_map.h"
 #include "build_settings.h"
 #include "gn/source_file.h"
 #include "gn/target.h"
@@ -34,16 +35,26 @@ using DependencyList = std::vector<Dependency>;
 class Crate {
  public:
   Crate(SourceFile root,
+        std::optional<OutputFile> gen_dir,
         CrateIndex index,
         std::string label,
         std::string edition)
-      : root_(root), index_(index), label_(label), edition_(edition) {}
+      : root_(root),
+        gen_dir_(gen_dir),
+        index_(index),
+        label_(label),
+        edition_(edition) {}
 
   ~Crate() = default;
 
   // Add a config item to the crate.
   void AddConfigItem(std::string cfg_item) { configs_.push_back(cfg_item); }
 
+  // Add a key-value environment variable pair used when building this crate.
+  void AddRustenv(std::string key, std::string value) {
+    rustenv_.emplace(key, value);
+  }
+
   // Add another crate as a dependency of this one.
   void AddDependency(CrateIndex index, std::string name) {
     deps_.push_back(std::make_pair(index, name));
@@ -55,11 +66,19 @@ class Crate {
   // Set the compiler target ("e.g. x86_64-linux-kernel")
   void SetCompilerTarget(std::string target) { compiler_target_ = target; }
 
+  // Set that this is a proc macro with the path to the output .so/dylib/dll
+  void SetIsProcMacro(OutputFile proc_macro_dynamic_library) {
+    proc_macro_dynamic_library_ = proc_macro_dynamic_library;
+  }
+
   // Returns the root file for the crate.
   SourceFile& root() { return root_; }
 
+  // Returns the root file for the crate.
+  std::optional<OutputFile>& gen_dir() { return gen_dir_; }
+
   // Returns the crate index.
-  CrateIndex index() { return index_; };
+  CrateIndex index() { return index_; }
 
   // Returns the displayable crate label.
   const std::string& label() { return label_; }
@@ -81,8 +100,18 @@ class Crate {
     return compiler_target_;
   }
 
+  // Returns whether this crate builds a proc macro .so
+  const std::optional<OutputFile>& proc_macro_path() {
+    return proc_macro_dynamic_library_;
+  }
+
+  // Returns environment variables applied to this, which may be necessary
+  // for correct functioning of environment variables
+  const base::flat_map<std::string, std::string>& rustenv() { return rustenv_; }
+
  private:
   SourceFile root_;
+  std::optional<OutputFile> gen_dir_;
   CrateIndex index_;
   std::string label_;
   std::string edition_;
@@ -90,29 +119,17 @@ class Crate {
   DependencyList deps_;
   std::optional<std::string> compiler_target_;
   std::vector<std::string> compiler_args_;
+  std::optional<OutputFile> proc_macro_dynamic_library_;
+  base::flat_map<std::string, std::string> rustenv_;
 };
 
 using CrateList = std::vector<Crate>;
 
-// Mapping of a sysroot crate (path) to it's index in the crates list.
-using SysrootCrateIndexMap = std::unordered_map<std::string_view, CrateIndex>;
-
-// Mapping of a sysroot (path) to the mapping of each of the sysroot crates to
-// their index in the crates list.
-using SysrootIndexMap =
-    std::unordered_map<std::string_view, SysrootCrateIndexMap>;
-
-// Add all of the crates for a sysroot (path) to the rust_project ostream.
-// Add the given sysroot to the project, if it hasn't already been added.
-void AddSysroot(const BuildSettings* build_settings,
-                std::string_view sysroot,
-                SysrootIndexMap& sysroot_lookup,
-                CrateList& crate_list);
-
 // Write the entire rust-project.json file contents into the given stream, based
 // on the the given crates list.
 void WriteCrates(const BuildSettings* build_settings,
                  CrateList& crate_list,
+                 std::optional<std::string>& sysroot,
                  std::ostream& rust_project);
 
 // Assemble the compiler arguments for the given GN Target.
diff --git a/gn/src/gn/rust_project_writer_helpers_unittest.cc b/gn/src/gn/rust_project_writer_helpers_unittest.cc
index 7ff3b487533..14d5c3547b0 100644
--- a/gn/src/gn/rust_project_writer_helpers_unittest.cc
+++ b/gn/src/gn/rust_project_writer_helpers_unittest.cc
@@ -26,11 +26,13 @@ using RustProjectWriterHelper = TestWithScheduler;
 TEST_F(RustProjectWriterHelper, WriteCrates) {
   TestWithScope setup;
 
+  std::optional<std::string> sysroot;
+
   CrateList crates;
-  Crate dep =
-      Crate(SourceFile("/root/tortoise/lib.rs"), 0, "//tortoise:bar", "2015");
-  Crate target =
-      Crate(SourceFile("/root/hare/lib.rs"), 1, "//hare:bar", "2015");
+  Crate dep = Crate(SourceFile("/root/tortoise/lib.rs"), std::nullopt, 0,
+                    "//tortoise:bar", "2015");
+  Crate target = Crate(SourceFile("/root/hare/lib.rs"),
+                       OutputFile("gendir/hare/"), 1, "//hare:bar", "2015");
   target.AddDependency(0, "tortoise");
   target.AddConfigItem("unix");
   target.AddConfigItem("feature=\"test\"");
@@ -39,22 +41,24 @@ TEST_F(RustProjectWriterHelper, WriteCrates) {
   crates.push_back(target);
 
   std::ostringstream stream;
-  WriteCrates(setup.build_settings(), crates, stream);
+  WriteCrates(setup.build_settings(), crates, sysroot, stream);
   std::string out = stream.str();
 #if defined(OS_WIN)
   base::ReplaceSubstringsAfterOffset(&out, 0, "\r\n", "\n");
 #endif
   const char expected_json[] =
       "{\n"
-      "  \"roots\": [\n"
-      "    \"/root/hare/\",\n"
-      "    \"/root/tortoise/\"\n"
-      "  ],\n"
       "  \"crates\": [\n"
       "    {\n"
       "      \"crate_id\": 0,\n"
       "      \"root_module\": \"/root/tortoise/lib.rs\",\n"
       "      \"label\": \"//tortoise:bar\",\n"
+      "      \"source\": {\n"
+      "          \"include_dirs\": [\n"
+      "               \"/root/tortoise/\"\n"
+      "          ],\n"
+      "          \"exclude_dirs\": []\n"
+      "      },\n"
       "      \"deps\": [\n"
       "      ],\n"
       "      \"edition\": \"2015\",\n"
@@ -65,6 +69,13 @@ TEST_F(RustProjectWriterHelper, WriteCrates) {
       "      \"crate_id\": 1,\n"
       "      \"root_module\": \"/root/hare/lib.rs\",\n"
       "      \"label\": \"//hare:bar\",\n"
+      "      \"source\": {\n"
+      "          \"include_dirs\": [\n"
+      "               \"/root/hare/\",\n"
+      "               \"out/Debug/gendir/hare/\"\n"
+      "          ],\n"
+      "          \"exclude_dirs\": []\n"
+      "      },\n"
       "      \"deps\": [\n"
       "        {\n"
       "          \"crate\": 0,\n"
@@ -87,13 +98,11 @@ TEST_F(RustProjectWriterHelper, SysrootDepsAreCorrect) {
   TestWithScope setup;
   setup.build_settings()->SetRootPath(UTF8ToFilePath("/root"));
 
-  SysrootIndexMap sysroot_lookup;
+  std::optional<std::string> sysroot = "sysroot";
   CrateList crates;
 
-  AddSysroot(setup.build_settings(), "sysroot", sysroot_lookup, crates);
-
   std::ostringstream stream;
-  WriteCrates(setup.build_settings(), crates, stream);
+  WriteCrates(setup.build_settings(), crates, sysroot, stream);
   std::string out = stream.str();
 #if defined(OS_WIN)
   base::ReplaceSubstringsAfterOffset(&out, 0, "\r\n", "\n");
@@ -101,125 +110,8 @@ TEST_F(RustProjectWriterHelper, SysrootDepsAreCorrect) {
 
   const char expected_json[] =
       "{\n"
-      "  \"roots\": [\n"
-      "    \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/alloc/src/\",\n"
-      "    \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/core/src/\",\n"
-      "    \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/panic_abort/src/\",\n"
-      "    \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/panic_unwind/src/\",\n"
-      "    \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/proc_macro/src/\",\n"
-      "    \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/std/src/\",\n"
-      "    \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/test/src/\",\n"
-      "    \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/unwind/src/\"\n"
-      "  ],\n"
+      "  \"sysroot\": \"/root/out/Debug/sysroot\",\n"
       "  \"crates\": [\n"
-      "    {\n"
-      "      \"crate_id\": 0,\n"
-      "      \"root_module\": \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/core/src/lib.rs\",\n"
-      "      \"label\": \"core\",\n"
-      "      \"deps\": [\n"
-      "      ],\n"
-      "      \"edition\": \"2018\",\n"
-      "      \"cfg\": [\n"
-      "        \"debug_assertions\"\n"
-      "      ]\n"
-      "    },\n"
-      "    {\n"
-      "      \"crate_id\": 1,\n"
-      "      \"root_module\": \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/alloc/src/lib.rs\",\n"
-      "      \"label\": \"alloc\",\n"
-      "      \"deps\": [\n"
-      "        {\n"
-      "          \"crate\": 0,\n"
-      "          \"name\": \"core\"\n"
-      "        }\n"
-      "      ],\n"
-      "      \"edition\": \"2018\",\n"
-      "      \"cfg\": [\n"
-      "        \"debug_assertions\"\n"
-      "      ]\n"
-      "    },\n"
-      "    {\n"
-      "      \"crate_id\": 2,\n"
-      "      \"root_module\": \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/panic_abort/src/lib.rs\",\n"
-      "      \"label\": \"panic_abort\",\n"
-      "      \"deps\": [\n"
-      "      ],\n"
-      "      \"edition\": \"2018\",\n"
-      "      \"cfg\": [\n"
-      "        \"debug_assertions\"\n"
-      "      ]\n"
-      "    },\n"
-      "    {\n"
-      "      \"crate_id\": 3,\n"
-      "      \"root_module\": \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/unwind/src/lib.rs\",\n"
-      "      \"label\": \"unwind\",\n"
-      "      \"deps\": [\n"
-      "      ],\n"
-      "      \"edition\": \"2018\",\n"
-      "      \"cfg\": [\n"
-      "        \"debug_assertions\"\n"
-      "      ]\n"
-      "    },\n"
-      "    {\n"
-      "      \"crate_id\": 4,\n"
-      "      \"root_module\": \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/std/src/lib.rs\",\n"
-      "      \"label\": \"std\",\n"
-      "      \"deps\": [\n"
-      "        {\n"
-      "          \"crate\": 1,\n"
-      "          \"name\": \"alloc\"\n"
-      "        },\n"
-      "        {\n"
-      "          \"crate\": 0,\n"
-      "          \"name\": \"core\"\n"
-      "        },\n"
-      "        {\n"
-      "          \"crate\": 2,\n"
-      "          \"name\": \"panic_abort\"\n"
-      "        },\n"
-      "        {\n"
-      "          \"crate\": 3,\n"
-      "          \"name\": \"unwind\"\n"
-      "        }\n"
-      "      ],\n"
-      "      \"edition\": \"2018\",\n"
-      "      \"cfg\": [\n"
-      "        \"debug_assertions\"\n"
-      "      ]\n"
-      "    },\n"
-      "    {\n"
-      "      \"crate_id\": 5,\n"
-      "      \"root_module\": \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/panic_unwind/src/lib.rs\",\n"
-      "      \"label\": \"panic_unwind\",\n"
-      "      \"deps\": [\n"
-      "      ],\n"
-      "      \"edition\": \"2018\",\n"
-      "      \"cfg\": [\n"
-      "        \"debug_assertions\"\n"
-      "      ]\n"
-      "    },\n"
-      "    {\n"
-      "      \"crate_id\": 6,\n"
-      "      \"root_module\": \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/proc_macro/src/lib.rs\",\n"
-      "      \"label\": \"proc_macro\",\n"
-      "      \"deps\": [\n"
-      "      ],\n"
-      "      \"edition\": \"2018\",\n"
-      "      \"cfg\": [\n"
-      "        \"debug_assertions\"\n"
-      "      ]\n"
-      "    },\n"
-      "    {\n"
-      "      \"crate_id\": 7,\n"
-      "      \"root_module\": \"/root/out/Debug/sysroot/lib/rustlib/src/rust/library/test/src/lib.rs\",\n"
-      "      \"label\": \"test\",\n"
-      "      \"deps\": [\n"
-      "      ],\n"
-      "      \"edition\": \"2018\",\n"
-      "      \"cfg\": [\n"
-      "        \"debug_assertions\"\n"
-      "      ]\n"
-      "    }\n"
       "  ]\n"
       "}\n";
 
diff --git a/gn/src/gn/rust_project_writer_unittest.cc b/gn/src/gn/rust_project_writer_unittest.cc
index 675f9a6a387..81b24b0d690 100644
--- a/gn/src/gn/rust_project_writer_unittest.cc
+++ b/gn/src/gn/rust_project_writer_unittest.cc
@@ -51,14 +51,18 @@ TEST_F(RustProjectJSONWriter, OneRustTarget) {
 #endif
   const char expected_json[] =
       "{\n"
-      "  \"roots\": [\n"
-      "    \"path/foo/\"\n"
-      "  ],\n"
       "  \"crates\": [\n"
       "    {\n"
       "      \"crate_id\": 0,\n"
       "      \"root_module\": \"path/foo/lib.rs\",\n"
       "      \"label\": \"//foo:bar\",\n"
+      "      \"source\": {\n"
+      "          \"include_dirs\": [\n"
+      "               \"path/foo/\",\n"
+      "               \"path/out/Debug/gen/foo/\"\n"
+      "          ],\n"
+      "          \"exclude_dirs\": []\n"
+      "      },\n"
       "      \"compiler_args\": [\"--cfg=feature=\\\"foo_enabled\\\"\"],\n"
       "      \"deps\": [\n"
       "      ],\n"
@@ -88,6 +92,7 @@ TEST_F(RustProjectJSONWriter, RustTargetDep) {
   dep.rust_values().set_crate_root(tlib);
   dep.rust_values().crate_name() = "tortoise";
   dep.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(dep.OnResolved(&err));
 
   Target target(setup.settings(), Label(SourceDir("//hare/"), "bar"));
   target.set_output_type(Target::RUST_LIBRARY);
@@ -111,15 +116,18 @@ TEST_F(RustProjectJSONWriter, RustTargetDep) {
 #endif
   const char expected_json[] =
       "{\n"
-      "  \"roots\": [\n"
-      "    \"hare/\",\n"
-      "    \"tortoise/\"\n"
-      "  ],\n"
       "  \"crates\": [\n"
       "    {\n"
       "      \"crate_id\": 0,\n"
       "      \"root_module\": \"tortoise/lib.rs\",\n"
       "      \"label\": \"//tortoise:bar\",\n"
+      "      \"source\": {\n"
+      "          \"include_dirs\": [\n"
+      "               \"tortoise/\",\n"
+      "               \"out/Debug/gen/tortoise/\"\n"
+      "          ],\n"
+      "          \"exclude_dirs\": []\n"
+      "      },\n"
       "      \"deps\": [\n"
       "      ],\n"
       "      \"edition\": \"2015\",\n"
@@ -132,6 +140,13 @@ TEST_F(RustProjectJSONWriter, RustTargetDep) {
       "      \"crate_id\": 1,\n"
       "      \"root_module\": \"hare/lib.rs\",\n"
       "      \"label\": \"//hare:bar\",\n"
+      "      \"source\": {\n"
+      "          \"include_dirs\": [\n"
+      "               \"hare/\",\n"
+      "               \"out/Debug/gen/hare/\"\n"
+      "          ],\n"
+      "          \"exclude_dirs\": []\n"
+      "      },\n"
       "      \"deps\": [\n"
       "        {\n"
       "          \"crate\": 0,\n"
@@ -163,6 +178,7 @@ TEST_F(RustProjectJSONWriter, RustTargetDepTwo) {
   dep.rust_values().set_crate_root(tlib);
   dep.rust_values().crate_name() = "tortoise";
   dep.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(dep.OnResolved(&err));
 
   Target dep2(setup.settings(), Label(SourceDir("//achilles/"), "bar"));
   dep2.set_output_type(Target::RUST_LIBRARY);
@@ -173,6 +189,7 @@ TEST_F(RustProjectJSONWriter, RustTargetDepTwo) {
   dep2.rust_values().set_crate_root(alib);
   dep2.rust_values().crate_name() = "achilles";
   dep2.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(dep2.OnResolved(&err));
 
   Target target(setup.settings(), Label(SourceDir("//hare/"), "bar"));
   target.set_output_type(Target::RUST_LIBRARY);
@@ -197,16 +214,18 @@ TEST_F(RustProjectJSONWriter, RustTargetDepTwo) {
 #endif
   const char expected_json[] =
       "{\n"
-      "  \"roots\": [\n"
-      "    \"achilles/\",\n"
-      "    \"hare/\",\n"
-      "    \"tortoise/\"\n"
-      "  ],\n"
       "  \"crates\": [\n"
       "    {\n"
       "      \"crate_id\": 0,\n"
       "      \"root_module\": \"tortoise/lib.rs\",\n"
       "      \"label\": \"//tortoise:bar\",\n"
+      "      \"source\": {\n"
+      "          \"include_dirs\": [\n"
+      "               \"tortoise/\",\n"
+      "               \"out/Debug/gen/tortoise/\"\n"
+      "          ],\n"
+      "          \"exclude_dirs\": []\n"
+      "      },\n"
       "      \"deps\": [\n"
       "      ],\n"
       "      \"edition\": \"2015\",\n"
@@ -219,6 +238,13 @@ TEST_F(RustProjectJSONWriter, RustTargetDepTwo) {
       "      \"crate_id\": 1,\n"
       "      \"root_module\": \"achilles/lib.rs\",\n"
       "      \"label\": \"//achilles:bar\",\n"
+      "      \"source\": {\n"
+      "          \"include_dirs\": [\n"
+      "               \"achilles/\",\n"
+      "               \"out/Debug/gen/achilles/\"\n"
+      "          ],\n"
+      "          \"exclude_dirs\": []\n"
+      "      },\n"
       "      \"deps\": [\n"
       "      ],\n"
       "      \"edition\": \"2015\",\n"
@@ -231,6 +257,13 @@ TEST_F(RustProjectJSONWriter, RustTargetDepTwo) {
       "      \"crate_id\": 2,\n"
       "      \"root_module\": \"hare/lib.rs\",\n"
       "      \"label\": \"//hare:bar\",\n"
+      "      \"source\": {\n"
+      "          \"include_dirs\": [\n"
+      "               \"hare/\",\n"
+      "               \"out/Debug/gen/hare/\"\n"
+      "          ],\n"
+      "          \"exclude_dirs\": []\n"
+      "      },\n"
       "      \"deps\": [\n"
       "        {\n"
       "          \"crate\": 0,\n"
@@ -267,18 +300,21 @@ TEST_F(RustProjectJSONWriter, RustTargetGetDepRustOnly) {
   dep.rust_values().set_crate_root(tlib);
   dep.rust_values().crate_name() = "tortoise";
   dep.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(dep.OnResolved(&err));
 
   Target dep2(setup.settings(), Label(SourceDir("//achilles/"), "bar"));
   dep2.set_output_type(Target::STATIC_LIBRARY);
   dep2.visibility().SetPublic();
   SourceFile alib("//achilles/lib.o");
   dep2.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(dep2.OnResolved(&err));
 
   Target dep3(setup.settings(), Label(SourceDir("//achilles/"), "group"));
   dep3.set_output_type(Target::GROUP);
   dep3.visibility().SetPublic();
   dep3.public_deps().push_back(LabelTargetPair(&dep));
   dep3.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(dep3.OnResolved(&err));
 
   Target dep4(setup.settings(), Label(SourceDir("//tortoise/"), "macro"));
   dep4.set_output_type(Target::RUST_PROC_MACRO);
@@ -289,6 +325,7 @@ TEST_F(RustProjectJSONWriter, RustTargetGetDepRustOnly) {
   dep4.rust_values().set_crate_root(tmlib);
   dep4.rust_values().crate_name() = "tortoise_macro";
   dep4.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(dep4.OnResolved(&err));
 
   Target target(setup.settings(), Label(SourceDir("//hare/"), "bar"));
   target.set_output_type(Target::RUST_LIBRARY);
@@ -314,16 +351,18 @@ TEST_F(RustProjectJSONWriter, RustTargetGetDepRustOnly) {
 #endif
   const char expected_json[] =
       "{\n"
-      "  \"roots\": [\n"
-      "    \"hare/\",\n"
-      "    \"tortoise/\",\n"
-      "    \"tortoise/macro/\"\n"
-      "  ],\n"
       "  \"crates\": [\n"
       "    {\n"
       "      \"crate_id\": 0,\n"
       "      \"root_module\": \"tortoise/lib.rs\",\n"
       "      \"label\": \"//tortoise:bar\",\n"
+      "      \"source\": {\n"
+      "          \"include_dirs\": [\n"
+      "               \"tortoise/\",\n"
+      "               \"out/Debug/gen/tortoise/\"\n"
+      "          ],\n"
+      "          \"exclude_dirs\": []\n"
+      "      },\n"
       "      \"deps\": [\n"
       "      ],\n"
       "      \"edition\": \"2015\",\n"
@@ -336,9 +375,19 @@ TEST_F(RustProjectJSONWriter, RustTargetGetDepRustOnly) {
       "      \"crate_id\": 1,\n"
       "      \"root_module\": \"tortoise/macro/lib.rs\",\n"
       "      \"label\": \"//tortoise:macro\",\n"
+      "      \"source\": {\n"
+      "          \"include_dirs\": [\n"
+      "               \"tortoise/macro/\",\n"
+      "               \"out/Debug/gen/tortoise/\"\n"
+      "          ],\n"
+      "          \"exclude_dirs\": []\n"
+      "      },\n"
       "      \"deps\": [\n"
       "      ],\n"
       "      \"edition\": \"2015\",\n"
+      "      \"is_proc_macro\": true,\n"
+      "      \"proc_macro_dylib_path\": "
+      "\"out/Debug/obj/tortoise/libmacro.so\",\n"
       "      \"cfg\": [\n"
       "        \"test\",\n"
       "        \"debug_assertions\"\n"
@@ -348,6 +397,13 @@ TEST_F(RustProjectJSONWriter, RustTargetGetDepRustOnly) {
       "      \"crate_id\": 2,\n"
       "      \"root_module\": \"hare/lib.rs\",\n"
       "      \"label\": \"//hare:bar\",\n"
+      "      \"source\": {\n"
+      "          \"include_dirs\": [\n"
+      "               \"hare/\",\n"
+      "               \"out/Debug/gen/hare/\"\n"
+      "          ],\n"
+      "          \"exclude_dirs\": []\n"
+      "      },\n"
       "      \"deps\": [\n"
       "        {\n"
       "          \"crate\": 0,\n"
@@ -398,14 +454,18 @@ TEST_F(RustProjectJSONWriter, OneRustTargetWithRustcTargetSet) {
 #endif
   const char expected_json[] =
       "{\n"
-      "  \"roots\": [\n"
-      "    \"path/foo/\"\n"
-      "  ],\n"
       "  \"crates\": [\n"
       "    {\n"
       "      \"crate_id\": 0,\n"
       "      \"root_module\": \"path/foo/lib.rs\",\n"
       "      \"label\": \"//foo:bar\",\n"
+      "      \"source\": {\n"
+      "          \"include_dirs\": [\n"
+      "               \"path/foo/\",\n"
+      "               \"path/out/Debug/gen/foo/\"\n"
+      "          ],\n"
+      "          \"exclude_dirs\": []\n"
+      "      },\n"
       "      \"target\": \"x86-64_unknown\",\n"
       "      \"compiler_args\": [\"--target\", \"x86-64_unknown\"],\n"
       "      \"deps\": [\n"
@@ -449,14 +509,18 @@ TEST_F(RustProjectJSONWriter, OneRustTargetWithEditionSet) {
 #endif
   const char expected_json[] =
       "{\n"
-      "  \"roots\": [\n"
-      "    \"path/foo/\"\n"
-      "  ],\n"
       "  \"crates\": [\n"
       "    {\n"
       "      \"crate_id\": 0,\n"
       "      \"root_module\": \"path/foo/lib.rs\",\n"
       "      \"label\": \"//foo:bar\",\n"
+      "      \"source\": {\n"
+      "          \"include_dirs\": [\n"
+      "               \"path/foo/\",\n"
+      "               \"path/out/Debug/gen/foo/\"\n"
+      "          ],\n"
+      "          \"exclude_dirs\": []\n"
+      "      },\n"
       "      \"compiler_args\": [\"--edition=2018\"],\n"
       "      \"deps\": [\n"
       "      ],\n"
@@ -500,14 +564,18 @@ TEST_F(RustProjectJSONWriter, OneRustTargetWithEditionSetAlternate) {
 #endif
   const char expected_json[] =
       "{\n"
-      "  \"roots\": [\n"
-      "    \"path/foo/\"\n"
-      "  ],\n"
       "  \"crates\": [\n"
       "    {\n"
       "      \"crate_id\": 0,\n"
       "      \"root_module\": \"path/foo/lib.rs\",\n"
       "      \"label\": \"//foo:bar\",\n"
+      "      \"source\": {\n"
+      "          \"include_dirs\": [\n"
+      "               \"path/foo/\",\n"
+      "               \"path/out/Debug/gen/foo/\"\n"
+      "          ],\n"
+      "          \"exclude_dirs\": []\n"
+      "      },\n"
       "      \"compiler_args\": [\"--edition\", \"2018\"],\n"
       "      \"deps\": [\n"
       "      ],\n"
@@ -521,4 +589,67 @@ TEST_F(RustProjectJSONWriter, OneRustTargetWithEditionSetAlternate) {
       "}\n";
 
   ExpectEqOrShowDiff(expected_json, out);
-}
-\ No newline at end of file
+}
+
+TEST_F(RustProjectJSONWriter, OneRustProcMacroTarget) {
+  Err err;
+  TestWithScope setup;
+  setup.build_settings()->SetRootPath(UTF8ToFilePath("path"));
+
+  Target target(setup.settings(), Label(SourceDir("//foo/"), "bar"));
+  target.set_output_type(Target::RUST_PROC_MACRO);
+  target.visibility().SetPublic();
+  SourceFile lib("//foo/lib.rs");
+  target.sources().push_back(lib);
+  target.source_types_used().Set(SourceFile::SOURCE_RS);
+  target.rust_values().set_crate_root(lib);
+  target.config_values().rustenv().push_back("TEST_ENV_VAR=baz");
+  target.config_values().rustenv().push_back("TEST_ENV_VAR2=baz2");
+  target.rust_values().crate_name() = "foo";
+  target.config_values().rustflags().push_back("--cfg=feature=\"foo_enabled\"");
+  target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target.OnResolved(&err));
+
+  std::ostringstream stream;
+  std::vector<const Target*> targets;
+  targets.push_back(&target);
+  RustProjectWriter::RenderJSON(setup.build_settings(), targets, stream);
+  std::string out = stream.str();
+#if defined(OS_WIN)
+  base::ReplaceSubstringsAfterOffset(&out, 0, "\r\n", "\n");
+#endif
+  const char expected_json[] =
+      "{\n"
+      "  \"crates\": [\n"
+      "    {\n"
+      "      \"crate_id\": 0,\n"
+      "      \"root_module\": \"path/foo/lib.rs\",\n"
+      "      \"label\": \"//foo:bar\",\n"
+      "      \"source\": {\n"
+      "          \"include_dirs\": [\n"
+      "               \"path/foo/\",\n"
+      "               \"path/out/Debug/gen/foo/\"\n"
+      "          ],\n"
+      "          \"exclude_dirs\": []\n"
+      "      },\n"
+      "      \"compiler_args\": [\"--cfg=feature=\\\"foo_enabled\\\"\"],\n"
+      "      \"deps\": [\n"
+      "      ],\n"
+      "      \"edition\": \"2015\",\n"
+      "      \"is_proc_macro\": true,\n"
+      "      \"proc_macro_dylib_path\": \"path/out/Debug/obj/foo/libbar.so\",\n"
+      "      \"cfg\": [\n"
+      "        \"test\",\n"
+      "        \"debug_assertions\",\n"
+      "        \"feature=\\\"foo_enabled\\\"\"\n"
+      "      ],\n"
+      "      \"env\": {\n"
+      "        \"TEST_ENV_VAR\": \"baz\",\n"
+      "        \"TEST_ENV_VAR2\": \"baz2\"\n"
+      "      }\n"
+      "    }\n"
+      "  ]\n"
+      "}\n";
+
+  ExpectEqOrShowDiff(expected_json, out);
+}
diff --git a/gn/src/gn/rust_substitution_type.cc b/gn/src/gn/rust_substitution_type.cc
index 69e6cf6a1db..5423d0dc7bf 100644
--- a/gn/src/gn/rust_substitution_type.cc
+++ b/gn/src/gn/rust_substitution_type.cc
@@ -42,6 +42,12 @@ bool IsValidRustSubstitution(const Substitution* type) {
          type == &kRustSubstitutionSources;
 }
 
+// Rust substitution types which we also make available to action targets.
+bool IsValidRustScriptArgsSubstitution(const Substitution* type) {
+  return type == &kRustSubstitutionRustEnv ||
+         type == &kRustSubstitutionRustFlags;
+}
+
 bool IsValidRustLinkerSubstitution(const Substitution* type) {
   return IsValidRustSubstitution(type) ||
          type == &CSubstitutionLdFlags;
diff --git a/gn/src/gn/rust_substitution_type.h b/gn/src/gn/rust_substitution_type.h
index 36ba9538436..5a6ac6cece5 100644
--- a/gn/src/gn/rust_substitution_type.h
+++ b/gn/src/gn/rust_substitution_type.h
@@ -23,6 +23,7 @@ extern const Substitution kRustSubstitutionRustFlags;
 extern const Substitution kRustSubstitutionSources;
 
 bool IsValidRustSubstitution(const Substitution* type);
+bool IsValidRustScriptArgsSubstitution(const Substitution* type);
 bool IsValidRustLinkerSubstitution(const Substitution* type);
 
 #endif  // TOOLS_GN_RUST_SUBSTITUTION_TYPE_H_
diff --git a/gn/src/gn/scope.cc b/gn/src/gn/scope.cc
index 05b09957ca9..d07426ad19b 100644
--- a/gn/src/gn/scope.cc
+++ b/gn/src/gn/scope.cc
@@ -39,6 +39,13 @@ Scope::ProgrammaticProvider::~ProgrammaticProvider() {
   scope_->RemoveProvider(this);
 }
 
+std::string Scope::TemplateInvocationEntry::Describe() const {
+  std::string ret = template_name;
+  ret += "(\"" + target_name + "\")  ";
+  ret += location.Describe(false);
+  return ret;
+}
+
 Scope::Scope(const Settings* settings)
     : const_containing_(nullptr),
       mutable_containing_(nullptr),
@@ -252,6 +259,17 @@ bool Scope::CheckForUnusedVars(Err* err) const {
           "You set the variable \"" + std::string(pair.first) +
           "\" here and it was unused before it went\nout of scope.";
 
+
+      // Gather the template invocations that led up to this scope.
+      auto entries = GetTemplateInvocationEntries();
+      if (entries.size() != 0) {
+
+        help.append("\n\nVia these template invocations:\n");
+        for (const auto& entry : entries) {
+          help.append("  " + entry.Describe() + "\n");
+        }
+      }
+
       const BinaryOpNode* binary = pair.second.value.origin()->AsBinaryOp();
       if (binary && binary->op().type() == Token::EQUAL) {
         // Make a nicer error message for normal var sets.
@@ -557,6 +575,41 @@ void Scope::RemoveProvider(ProgrammaticProvider* p) {
   programmatic_providers_.erase(p);
 }
 
+void Scope::SetTemplateInvocationEntry(std::string template_name,
+                                       std::string target_name,
+                                       Location location) {
+  template_invocation_entry_ = std::make_unique<TemplateInvocationEntry>(
+      TemplateInvocationEntry{std::move(template_name), std::move(target_name),
+                              std::move(location)});
+}
+
+const Scope::TemplateInvocationEntry* Scope::FindTemplateInvocationEntry() const {
+  if (template_invocation_entry_)
+    return template_invocation_entry_.get();
+  if (const Scope* scope = containing())
+    return scope->FindTemplateInvocationEntry();
+  return nullptr;
+}
+
+void Scope::AppendTemplateInvocationEntries(
+    std::vector<TemplateInvocationEntry>* out) const {
+
+  const Value* invoker = GetValue("invoker");
+  if (invoker && invoker->type() == Value::SCOPE)
+    invoker->scope_value()->AppendTemplateInvocationEntries(out);
+
+  const TemplateInvocationEntry* entry = FindTemplateInvocationEntry();
+  if (entry)
+    out->push_back(*entry);
+}
+
+std::vector<Scope::TemplateInvocationEntry>
+Scope::GetTemplateInvocationEntries() const {
+  std::vector<Scope::TemplateInvocationEntry> result;
+  AppendTemplateInvocationEntries(&result);
+  return result;
+}
+
 // static
 bool Scope::RecordMapValuesEqual(const RecordMap& a, const RecordMap& b) {
   if (a.size() != b.size())
diff --git a/gn/src/gn/scope.h b/gn/src/gn/scope.h
index 5412a41ace4..eb38202a723 100644
--- a/gn/src/gn/scope.h
+++ b/gn/src/gn/scope.h
@@ -8,6 +8,7 @@
 #include <map>
 #include <memory>
 #include <set>
+#include <string>
 #include <string_view>
 #include <unordered_map>
 #include <utility>
@@ -15,6 +16,7 @@
 
 #include "base/memory/ref_counted.h"
 #include "gn/err.h"
+#include "gn/location.h"
 #include "gn/pattern.h"
 #include "gn/source_dir.h"
 #include "gn/source_file.h"
@@ -94,6 +96,21 @@ class Scope {
     std::set<std::string> excluded_values;
   };
 
+  // Details about a Scope's creation as a template invocation
+  struct TemplateInvocationEntry {
+    // Produce a printable string that describes the template invocation:
+    //
+    // 'template_name("target_name")  //some/BUILD.gn:<line>'
+    //
+    // The target name is only the string that's passed to the template as the
+    // name, it's not a complete GN label.
+    std::string Describe() const;
+
+    std::string template_name;
+    std::string target_name;
+    Location location;
+  };
+
   // Creates an empty toplevel scope.
   explicit Scope(const Settings* settings);
 
@@ -319,6 +336,15 @@ class Scope {
   void SetProperty(const void* key, void* value);
   void* GetProperty(const void* key, const Scope** found_on_scope) const;
 
+  // Track template invocations for printing or debugging.
+  void SetTemplateInvocationEntry(std::string template_name,
+                                  std::string target_name,
+                                  Location location);
+
+  // Return a vector containing the current stack of template invocations that
+  // lead up to this scope.
+  std::vector<TemplateInvocationEntry> GetTemplateInvocationEntries() const;
+
  private:
   friend class ProgrammaticProvider;
 
@@ -339,6 +365,13 @@ class Scope {
   // of the values may be different).
   static bool RecordMapValuesEqual(const RecordMap& a, const RecordMap& b);
 
+  // Walk up the containing scopes and any "invoker" Value scopes to gather any
+  // previous template invocations.
+  void AppendTemplateInvocationEntries(std::vector<TemplateInvocationEntry>* out) const;
+
+  // Walk up the containing scopes to find a TemplateInvocationEntry.
+  const TemplateInvocationEntry* FindTemplateInvocationEntry() const;
+
   // Scopes can have no containing scope (both null), a mutable containing
   // scope, or a const containing scope. The reason is that when we're doing
   // a new target, we want to refer to the base_config scope which will be read
@@ -356,6 +389,9 @@ class Scope {
 
   RecordMap values_;
 
+  // If this is a template scope, track the template invocation.
+  std::unique_ptr<TemplateInvocationEntry> template_invocation_entry_;
+
   // Note that this can't use string pieces since the names are constructed from
   // Values which might be deallocated before this goes out of scope.
   using NamedScopeMap = std::unordered_map<std::string, std::unique_ptr<Scope>>;
diff --git a/gn/src/gn/settings.cc b/gn/src/gn/settings.cc
index 154e0af5eb2..c9a36c959ac 100644
--- a/gn/src/gn/settings.cc
+++ b/gn/src/gn/settings.cc
@@ -27,3 +27,12 @@ Settings::Settings(const BuildSettings* build_settings,
   if (!toolchain_output_dir_.is_null())
     toolchain_gen_dir_ = SourceDir(toolchain_output_dir_.value() + "gen/");
 }
+
+bool Settings::ShouldShowToolchain(
+    std::initializer_list<const Label*> labels) const {
+  for (auto label : labels) {
+    if (label->GetToolchainLabel() != default_toolchain_label_)
+      return true;
+  }
+  return false;
+}
diff --git a/gn/src/gn/settings.h b/gn/src/gn/settings.h
index 9b83b60fe8a..79d19049da6 100644
--- a/gn/src/gn/settings.h
+++ b/gn/src/gn/settings.h
@@ -86,6 +86,11 @@ class Settings {
     greedy_target_generation_ = gtg;
   }
 
+  // Returns true if any Label in the list provided is not in the default
+  // toolchain, and therefore any error message that involves this list of
+  // Labels should print the toolchain for each Label.
+  bool ShouldShowToolchain(std::initializer_list<const Label*> labels) const;
+
  private:
   const BuildSettings* build_settings_;
 
diff --git a/gn/src/gn/setup.cc b/gn/src/gn/setup.cc
index b6fdee2b4d9..139a919f44e 100644
--- a/gn/src/gn/setup.cc
+++ b/gn/src/gn/setup.cc
@@ -23,6 +23,7 @@
 #include "gn/exec_process.h"
 #include "gn/filesystem_utils.h"
 #include "gn/input_file.h"
+#include "gn/label_pattern.h"
 #include "gn/parse_tree.h"
 #include "gn/parser.h"
 #include "gn/source_dir.h"
@@ -116,6 +117,28 @@ Variables
           "//build/my_config.gni",
         ]
 
+  export_compile_commands [optional]
+      A list of label patterns for which to generate a Clang compilation
+      database (see "gn help label_pattern" for the string format).
+
+      When specified, GN will generate a compile_commands.json file in the root
+      of the build directory containing information on how to compile each
+      source file reachable from any label matching any pattern in the list.
+      This is used for Clang-based tooling and some editor integration. See
+      https://clang.llvm.org/docs/JSONCompilationDatabase.html
+
+      The switch --add-export-compile-commands to "gn gen" (see "gn help gen")
+      appends to this value which provides a per-user way to customize it.
+
+      The deprecated switch --export-compile-commands to "gn gen" (see "gn help
+      gen") adds to the export target list using a different format.
+
+      Example:
+        export_compile_commands = [
+          "//base/*",
+          "//tools:doom_melon",
+        ]
+
   root [optional]
       Label of the root build target. The GN build will start by loading the
       build file containing this target name. This defaults to "//:" which will
@@ -126,12 +149,14 @@ Variables
       help --root-target").
 
   script_executable [optional]
-      Path to specific Python executable or other interpreter to use in
-      action targets and exec_script calls. By default GN searches the
-      PATH for Python to execute these scripts.
+      By default, GN runs the scripts used in action targets and exec_script
+      calls using the Python interpreter found in PATH. This value specifies the
+      Python executable or other interpreter to use instead.
 
-      If set to the empty string, the path specified in action targets
-      and exec_script calls will be executed directly.
+      If set to the empty string, the scripts will be executed directly.
+
+      The command-line switch --script-executable will override this value (see
+      "gn help --script-executable")
 
   secondary_source [optional]
       Label of an alternate directory tree to find input files. When searching
@@ -507,7 +532,7 @@ bool Setup::FillArguments(const base::CommandLine& cmdline, Err* err) {
 
   base::FilePath build_arg_file =
       build_settings_.GetFullPath(GetBuildArgFile());
-  auto switch_value = cmdline.GetSwitchValueASCII(switches::kArgs);
+  auto switch_value = cmdline.GetSwitchValueString(switches::kArgs);
   if (cmdline.HasSwitch(switches::kArgs) ||
       (gen_empty_args_ && !PathExists(build_arg_file))) {
     if (!FillArgsFromCommandLine(
@@ -781,8 +806,19 @@ bool Setup::FillPythonPath(const base::CommandLine& cmdline, Err* err) {
     if (!value->VerifyTypeIs(Value::STRING, err)) {
       return false;
     }
-    build_settings_.set_python_path(
-        ProcessFileExtensions(UTF8ToFilePath(value->string_value())));
+    // Note that an empty string value is valid, and means that the scripts
+    // invoked by actions will be run directly.
+    base::FilePath python_path;
+    if (!value->string_value().empty()) {
+      python_path =
+          ProcessFileExtensions(UTF8ToFilePath(value->string_value()));
+      if (python_path.empty()) {
+        *err = Err(Location(), "Could not find \"" + value->string_value() +
+                                   "\" from dotfile in PATH.");
+        return false;
+      }
+    }
+    build_settings_.set_python_path(python_path);
   } else {
 #if defined(OS_WIN)
     base::FilePath python_path =
@@ -893,7 +929,7 @@ bool Setup::FillOtherConfig(const base::CommandLine& cmdline, Err* err) {
 
   // Root build file.
   if (cmdline.HasSwitch(switches::kRootTarget)) {
-    auto switch_value = cmdline.GetSwitchValueASCII(switches::kRootTarget);
+    auto switch_value = cmdline.GetSwitchValueString(switches::kRootTarget);
     Value root_value(nullptr, switch_value);
     root_target_label = Label::Resolve(current_dir, std::string_view(), Label(),
                                        root_value, err);
@@ -1024,5 +1060,43 @@ bool Setup::FillOtherConfig(const base::CommandLine& cmdline, Err* err) {
     build_settings_.set_arg_file_template_path(path);
   }
 
+  // No stamp files.
+  const Value* no_stamp_files_value =
+      dotfile_scope_.GetValue("no_stamp_files", true);
+  if (no_stamp_files_value) {
+    if (!no_stamp_files_value->VerifyTypeIs(Value::BOOLEAN, err)) {
+      return false;
+    }
+    build_settings_.set_no_stamp_files(no_stamp_files_value->boolean_value());
+    CHECK(!build_settings_.no_stamp_files())
+        << "no_stamp_files does not work yet!";
+  }
+
+  // Export compile commands.
+  const Value* export_cc_value =
+      dotfile_scope_.GetValue("export_compile_commands", true);
+  if (export_cc_value) {
+    if (!ExtractListOfLabelPatterns(&build_settings_, *export_cc_value,
+                                    SourceDir("//"), &export_compile_commands_,
+                                    err)) {
+      return false;
+    }
+  }
+
+  // Append any additional export compile command patterns from the cmdline.
+  for (const std::string& cur :
+       cmdline.GetSwitchValueStrings(switches::kAddExportCompileCommands)) {
+    LabelPattern pat = LabelPattern::GetPattern(
+        SourceDir("//"), build_settings_.root_path_utf8(), Value(nullptr, cur),
+        err);
+    if (err->has_error()) {
+      err->AppendSubErr(Err(
+          Location(),
+          "for the command-line switch --add-export-compile-commands=" + cur));
+      return false;
+    }
+    export_compile_commands_.push_back(std::move(pat));
+  }
+
   return true;
 }
diff --git a/gn/src/gn/setup.h b/gn/src/gn/setup.h
index 2809a7d3db7..b3abb1be0d6 100644
--- a/gn/src/gn/setup.h
+++ b/gn/src/gn/setup.h
@@ -113,6 +113,12 @@ class Setup {
     return no_check_patterns_.get();
   }
 
+  // This is a combination of the export_compile_commands list in the dotfile,
+  // and any additions specified on the command-line.
+  const std::vector<LabelPattern>& export_compile_commands() const {
+    return export_compile_commands_;
+  }
+
   BuildSettings& build_settings() { return build_settings_; }
   Builder& builder() { return builder_; }
   LoaderImpl* loader() { return loader_.get(); }
@@ -207,6 +213,8 @@ class Setup {
   std::vector<Token> args_tokens_;
   std::unique_ptr<ParseNode> args_root_;
 
+  std::vector<LabelPattern> export_compile_commands_;
+
   Setup(const Setup&) = delete;
   Setup& operator=(const Setup&) = delete;
 };
diff --git a/gn/src/gn/setup_unittest.cc b/gn/src/gn/setup_unittest.cc
index 370f7226c88..b46bf946c95 100644
--- a/gn/src/gn/setup_unittest.cc
+++ b/gn/src/gn/setup_unittest.cc
@@ -31,7 +31,7 @@ TEST_F(SetupTest, DotGNFileIsGenDep) {
   base::FilePath dot_gn_name = in_path.Append(FILE_PATH_LITERAL(".gn"));
   WriteFile(dot_gn_name, "buildconfig = \"//BUILDCONFIG.gn\"\n");
   WriteFile(in_path.Append(FILE_PATH_LITERAL("BUILDCONFIG.gn")), "");
-  cmdline.AppendSwitchASCII(switches::kRoot, FilePathToUTF8(in_path));
+  cmdline.AppendSwitchPath(switches::kRoot, in_path);
 
   // Create another temp dir for writing the generated files to.
   base::ScopedTempDir build_temp_dir;
@@ -46,6 +46,69 @@ TEST_F(SetupTest, DotGNFileIsGenDep) {
   EXPECT_EQ(gen_deps[0], base::MakeAbsoluteFilePath(dot_gn_name));
 }
 
+TEST_F(SetupTest, EmptyScriptExecutableDoesNotGenerateError) {
+  base::CommandLine cmdline(base::CommandLine::NO_PROGRAM);
+
+  const char kDotfileContents[] = R"(
+buildconfig = "//BUILDCONFIG.gn"
+script_executable = ""
+)";
+
+  // Create a temp directory containing a .gn file and a BUILDCONFIG.gn file,
+  // pass it as --root.
+  base::ScopedTempDir in_temp_dir;
+  ASSERT_TRUE(in_temp_dir.CreateUniqueTempDir());
+  base::FilePath in_path = in_temp_dir.GetPath();
+  base::FilePath dot_gn_name = in_path.Append(FILE_PATH_LITERAL(".gn"));
+  WriteFile(dot_gn_name, kDotfileContents);
+
+  WriteFile(in_path.Append(FILE_PATH_LITERAL("BUILDCONFIG.gn")), "");
+  cmdline.AppendSwitchPath(switches::kRoot, in_path);
+
+  // Create another temp dir for writing the generated files to.
+  base::ScopedTempDir build_temp_dir;
+  ASSERT_TRUE(build_temp_dir.CreateUniqueTempDir());
+
+  // Run setup and check that the .gn file is in the scheduler's gen deps.
+  Setup setup;
+  Err err;
+  EXPECT_TRUE(setup.DoSetupWithErr(FilePathToUTF8(build_temp_dir.GetPath()),
+                                   true, cmdline, &err));
+}
+
+#if defined(OS_WIN)
+TEST_F(SetupTest, MissingScriptExeGeneratesSetupErrorOnWindows) {
+  base::CommandLine cmdline(base::CommandLine::NO_PROGRAM);
+
+  const char kDotfileContents[] = R"(
+buildconfig = "//BUILDCONFIG.gn"
+script_executable = "this_does_not_exist"
+)";
+
+  // Create a temp directory containing a .gn file and a BUILDCONFIG.gn file,
+  // pass it as --root.
+  base::ScopedTempDir in_temp_dir;
+  ASSERT_TRUE(in_temp_dir.CreateUniqueTempDir());
+  base::FilePath in_path = in_temp_dir.GetPath();
+  base::FilePath dot_gn_name = in_path.Append(FILE_PATH_LITERAL(".gn"));
+  WriteFile(dot_gn_name, kDotfileContents);
+
+  WriteFile(in_path.Append(FILE_PATH_LITERAL("BUILDCONFIG.gn")), "");
+  cmdline.AppendSwitchPath(switches::kRoot, in_path);
+
+  // Create another temp dir for writing the generated files to.
+  base::ScopedTempDir build_temp_dir;
+  ASSERT_TRUE(build_temp_dir.CreateUniqueTempDir());
+
+  // Run setup and check that the .gn file is in the scheduler's gen deps.
+  Setup setup;
+  Err err;
+  EXPECT_FALSE(setup.DoSetupWithErr(FilePathToUTF8(build_temp_dir.GetPath()),
+                                    true, cmdline, &err));
+  EXPECT_TRUE(err.has_error());
+}
+#endif  // defined(OS_WIN)
+
 static void RunExtensionCheckTest(std::string extension,
                                   bool success,
                                   const std::string& expected_error_message) {
@@ -62,7 +125,7 @@ static void RunExtensionCheckTest(std::string extension,
       build_file_extension = \"" +
                 extension + "\"");
   WriteFile(in_path.Append(FILE_PATH_LITERAL("BUILDCONFIG.gn")), "");
-  cmdline.AppendSwitchASCII(switches::kRoot, FilePathToUTF8(in_path));
+  cmdline.AppendSwitchPath(switches::kRoot, in_path);
 
   // Create another temp dir for writing the generated files to.
   base::ScopedTempDir build_temp_dir;
@@ -85,9 +148,51 @@ TEST_F(SetupTest, NoSeparatorInExtension) {
 #else
       "Build file extension 'hello/world' cannot contain a path separator"
 #endif
-        );
+  );
 }
 
 TEST_F(SetupTest, Extension) {
   RunExtensionCheckTest("yay", true, "");
 }
+
+TEST_F(SetupTest, AddExportCompileCommands) {
+  base::CommandLine cmdline(base::CommandLine::NO_PROGRAM);
+
+  // Provide a project default export compile command list.
+  const char kDotfileContents[] = R"(
+buildconfig = "//BUILDCONFIG.gn"
+export_compile_commands = [ "//base/*" ]
+)";
+
+  // Create a temp directory containing the build.
+  base::ScopedTempDir in_temp_dir;
+  ASSERT_TRUE(in_temp_dir.CreateUniqueTempDir());
+  base::FilePath in_path = in_temp_dir.GetPath();
+  base::FilePath dot_gn_name = in_path.Append(FILE_PATH_LITERAL(".gn"));
+  WriteFile(dot_gn_name, kDotfileContents);
+
+  WriteFile(in_path.Append(FILE_PATH_LITERAL("BUILDCONFIG.gn")), "");
+  cmdline.AppendSwitch(switches::kRoot, FilePathToUTF8(in_path));
+
+  // Two additions to the compile commands list.
+  cmdline.AppendSwitch(switches::kAddExportCompileCommands,
+                       "//tools:doom_melon");
+  cmdline.AppendSwitch(switches::kAddExportCompileCommands, "//src/gn:*");
+
+  // Create another temp dir for writing the generated files to.
+  base::ScopedTempDir build_temp_dir;
+  ASSERT_TRUE(build_temp_dir.CreateUniqueTempDir());
+
+  // Run setup and check that the .gn file is in the scheduler's gen deps.
+  Setup setup;
+  Err err;
+  EXPECT_TRUE(setup.DoSetupWithErr(FilePathToUTF8(build_temp_dir.GetPath()),
+                                   true, cmdline, &err));
+
+  // The export compile commands should have three items.
+  const std::vector<LabelPattern>& export_cc = setup.export_compile_commands();
+  ASSERT_EQ(3u, export_cc.size());
+  EXPECT_EQ("//base/*", export_cc[0].Describe());
+  EXPECT_EQ("//tools:doom_melon", export_cc[1].Describe());
+  EXPECT_EQ("//src/gn:*", export_cc[2].Describe());
+}
diff --git a/gn/src/gn/string_atom.h b/gn/src/gn/string_atom.h
index c590e0b3c1c..51aa8d573a7 100644
--- a/gn/src/gn/string_atom.h
+++ b/gn/src/gn/string_atom.h
@@ -171,7 +171,7 @@ struct less<StringAtom> {
   template <typename U>
   bool operator()(const U& a, const StringAtom& b) const noexcept {
     return a < b.str();
-  };
+  }
 };
 
 template <>
diff --git a/gn/src/gn/substitution_list.cc b/gn/src/gn/substitution_list.cc
index 21311c665e2..aed66a060cd 100644
--- a/gn/src/gn/substitution_list.cc
+++ b/gn/src/gn/substitution_list.cc
@@ -49,13 +49,16 @@ bool SubstitutionList::Parse(const std::vector<std::string>& values,
 
 SubstitutionList SubstitutionList::MakeForTest(const char* a,
                                                const char* b,
-                                               const char* c) {
+                                               const char* c,
+                                               const char* d) {
   std::vector<std::string> input_strings;
   input_strings.push_back(a);
   if (b)
     input_strings.push_back(b);
   if (c)
     input_strings.push_back(c);
+  if (d)
+    input_strings.push_back(d);
 
   Err err;
   SubstitutionList result;
diff --git a/gn/src/gn/substitution_list.h b/gn/src/gn/substitution_list.h
index 559b25d1747..0dbf206412d 100644
--- a/gn/src/gn/substitution_list.h
+++ b/gn/src/gn/substitution_list.h
@@ -27,7 +27,8 @@ class SubstitutionList {
   // Makes a SubstitutionList from the given hardcoded patterns.
   static SubstitutionList MakeForTest(const char* a,
                                       const char* b = nullptr,
-                                      const char* c = nullptr);
+                                      const char* c = nullptr,
+                                      const char* d = nullptr);
 
   const std::vector<SubstitutionPattern>& list() const { return list_; }
 
diff --git a/gn/src/gn/substitution_type.cc b/gn/src/gn/substitution_type.cc
index 06c21b36ef1..723bf8a4469 100644
--- a/gn/src/gn/substitution_type.cc
+++ b/gn/src/gn/substitution_type.cc
@@ -163,7 +163,9 @@ bool IsValidSourceSubstitution(const Substitution* type) {
 }
 
 bool IsValidScriptArgsSubstitution(const Substitution* type) {
-  return IsValidSourceSubstitution(type) || type == &SubstitutionRspFileName;
+  return IsValidSourceSubstitution(type) || type == &SubstitutionRspFileName ||
+         IsValidCompilerScriptArgsSubstitution(type) ||
+         IsValidRustScriptArgsSubstitution(type);
 }
 
 bool IsValidToolSubstitution(const Substitution* type) {
diff --git a/gn/src/gn/substitution_writer_unittest.cc b/gn/src/gn/substitution_writer_unittest.cc
index fc3c44692a7..eaa521ab9c3 100644
--- a/gn/src/gn/substitution_writer_unittest.cc
+++ b/gn/src/gn/substitution_writer_unittest.cc
@@ -45,6 +45,12 @@ TEST(SubstitutionWriter, ApplyPatternToSource) {
   SourceFile result = SubstitutionWriter::ApplyPatternToSource(
       nullptr, setup.settings(), pattern, SourceFile("//foo/bar/myfile.txt"));
   ASSERT_EQ("//out/Debug/gen/foo/bar/myfile.tmp", result.value());
+
+  result = SubstitutionWriter::ApplyPatternToSource(
+      nullptr, setup.settings(), pattern,
+      SourceFile("//out/Debug/gen/generated_file.cc"));
+  ASSERT_EQ("//out/Debug/gen/BUILD_DIR/gen/generated_file.tmp", result.value())
+      << result.value();
 }
 
 TEST(SubstitutionWriter, ApplyPatternToSourceAsOutputFile) {
diff --git a/gn/src/gn/swift_values.cc b/gn/src/gn/swift_values.cc
index a70c72f096d..3cfd37770c5 100644
--- a/gn/src/gn/swift_values.cc
+++ b/gn/src/gn/swift_values.cc
@@ -48,7 +48,7 @@ void SwiftValues::FillModuleDependencies(Target* target) {
           pair.ptr->swift_values().public_modules().end());
   }
 
-  if (target->swift_values().builds_module())
+  if (target->builds_swift_module())
     target->swift_values().public_modules_.push_back(target);
 }
 
diff --git a/gn/src/gn/swift_values.h b/gn/src/gn/swift_values.h
index 3852366637a..91ec066ca1f 100644
--- a/gn/src/gn/swift_values.h
+++ b/gn/src/gn/swift_values.h
@@ -35,9 +35,6 @@ class SwiftValues {
   std::string& module_name() { return module_name_; }
   const std::string module_name() const { return module_name_; }
 
-  // Returns whether the target generates a .swiftmodule.
-  bool builds_module() const { return !module_output_file_.value().empty(); }
-
   // Name of the generated .swiftmodule file. Computed when the target
   // is resolved.
   const OutputFile& module_output_file() const { return module_output_file_; }
diff --git a/gn/src/gn/switches.cc b/gn/src/gn/switches.cc
index 6caec3a9dd5..d86c349bd6b 100644
--- a/gn/src/gn/switches.cc
+++ b/gn/src/gn/switches.cc
@@ -119,8 +119,8 @@ const char kScriptExecutable_Help[] =
   action targets and exec_script calls. By default GN searches the
   PATH for Python to execute these scripts.
 
-  If set to the empty string, the path specified in action targets
-  and exec_script calls will be executed directly.
+  If set to the empty string, the path of scripts specified in action
+  targets and exec_script calls will be executed directly.
 )";
 
 const char kQuiet[] = "q";
@@ -153,8 +153,7 @@ Examples
 )";
 
 const char kRootTarget[] = "root-target";
-const char kRootTarget_HelpShort[] =
-    "--root-target: Override the root target.";
+const char kRootTarget_HelpShort[] = "--root-target: Override the root target.";
 const char kRootTarget_Help[] =
     R"(--root-target: Override the root target.
 
@@ -284,6 +283,9 @@ const char kVersion_Help[] = "";
 const char kDefaultToolchain[] = "default-toolchain";
 
 const char kRegeneration[] = "regeneration";
+
+const char kAddExportCompileCommands[] = "add-export-compile-commands";
+
 // -----------------------------------------------------------------------------
 
 SwitchInfo::SwitchInfo() : short_help(""), long_help("") {}
diff --git a/gn/src/gn/switches.h b/gn/src/gn/switches.h
index 22099d3914b..3d1943fee57 100644
--- a/gn/src/gn/switches.h
+++ b/gn/src/gn/switches.h
@@ -114,6 +114,10 @@ extern const char kDefaultToolchain[];
 // so it can be shared between command_gen and ninja_build_writer.
 extern const char kRegeneration[];
 
+// This switch is read by Setup so needs to be in this global place, but is
+// relevant only by command_gen so is documented there.
+extern const char kAddExportCompileCommands[];
+
 }  // namespace switches
 
 #endif  // TOOLS_GN_SWITCHES_H_
diff --git a/gn/src/gn/target.cc b/gn/src/gn/target.cc
index 508ad7e11e6..2cebcf7b9b3 100644
--- a/gn/src/gn/target.cc
+++ b/gn/src/gn/target.cc
@@ -44,12 +44,16 @@ void MergeAllDependentConfigsFrom(const Target* from_target,
 }
 
 Err MakeTestOnlyError(const Item* from, const Item* to) {
+  bool with_toolchain = from->settings()->ShouldShowToolchain({
+    &from->label(),
+    &to->label(),
+  });
   return Err(
       from->defined_from(), "Test-only dependency not allowed.",
-      from->label().GetUserVisibleName(false) +
+      from->label().GetUserVisibleName(with_toolchain) +
           "\n"
           "which is NOT marked testonly can't depend on\n" +
-          to->label().GetUserVisibleName(false) +
+          to->label().GetUserVisibleName(with_toolchain) +
           "\n"
           "which is marked testonly. Only targets with \"testonly = true\"\n"
           "can depend on other test-only targets.\n"
@@ -760,48 +764,45 @@ void Target::PullDependentTargetLibsFrom(const Target* dep, bool is_public) {
   if (dep->output_type() == STATIC_LIBRARY ||
       dep->output_type() == SHARED_LIBRARY ||
       dep->output_type() == RUST_LIBRARY ||
-      dep->output_type() == RUST_PROC_MACRO ||
       dep->output_type() == SOURCE_SET ||
       (dep->output_type() == CREATE_BUNDLE &&
        dep->bundle_data().is_framework())) {
     inherited_libraries_.Append(dep, is_public);
   }
 
+  // Collect Rust libraries that are accessible from the current target, or
+  // transitively part of the current target.
   if (dep->output_type() == STATIC_LIBRARY ||
       dep->output_type() == SHARED_LIBRARY ||
-      dep->output_type() == RUST_LIBRARY) {
-    rust_transitive_libs_.Append(dep, is_public);
-
-    // Propagate public dependent libraries.
-    for (const auto& transitive :
-         dep->rust_transitive_libs_.GetOrderedAndPublicFlag()) {
-      if (transitive.second) {
-        rust_transitive_libs_.Append(transitive.first, is_public);
-      }
-    }
+      dep->output_type() == SOURCE_SET || dep->output_type() == RUST_LIBRARY ||
+      dep->output_type() == GROUP) {
+    // Here we have: `this` --[depends-on]--> `dep`
+    //
+    // The `this` target has direct access to `dep` since its a direct
+    // dependency, regardless of the edge being a public_dep or not, so we pass
+    // true for public-ness. Whereas, anything depending on `this` can only gain
+    // direct access to `dep` if the edge between `this` and `dep` is public, so
+    // we pass `is_public`.
+    //
+    // TODO(danakj): We should only need to track Rust rlibs or dylibs here, as
+    // it's used for passing to rustc with --extern. We currently track
+    // everything then drop non-Rust libs in ninja_rust_binary_target_writer.cc.
+    rust_transitive_inherited_libs_.Append(dep, true);
+    rust_transitive_inheritable_libs_.Append(dep, is_public);
+
+    rust_transitive_inherited_libs_.AppendInherited(
+        dep->rust_transitive_inheritable_libs(), true);
+    rust_transitive_inheritable_libs_.AppendInherited(
+        dep->rust_transitive_inheritable_libs(), is_public);
+  } else if (dep->output_type() == RUST_PROC_MACRO) {
+    // Proc-macros are inherited as a transitive dependency, but the things they
+    // depend on can't be used elsewhere, as the proc macro is not linked into
+    // the target (as it's only used during compilation).
+    rust_transitive_inherited_libs_.Append(dep, true);
+    rust_transitive_inheritable_libs_.Append(dep, is_public);
   }
 
-  // Rust libraries (those meant for consumption by another Rust target) are
-  // handled the same way, whether static or dynamic.
-  if (dep->output_type() == RUST_LIBRARY ||
-      RustValues::InferredCrateType(dep) == RustValues::CRATE_DYLIB) {
-    rust_transitive_libs_.AppendInherited(dep->rust_transitive_libs_,
-                                          is_public);
-
-    // If there is a transitive dependency that is not a rust library, place it
-    // in the normal location
-    for (const auto& inherited :
-         rust_transitive_libs_.GetOrderedAndPublicFlag()) {
-      if (!RustValues::IsRustLibrary(inherited.first)) {
-        inherited_libraries_.Append(inherited.first, inherited.second);
-      }
-    }
-  } else if (dep->output_type() == RUST_PROC_MACRO) {
-    // We will need to specify the path to find a procedural macro,
-    // but have no need to specify the paths to find its dependencies
-    // as the procedural macro is now a complete .so.
-    rust_transitive_libs_.Append(dep, is_public);
-  } else if (dep->output_type() == SHARED_LIBRARY) {
+  if (dep->output_type() == SHARED_LIBRARY) {
     // Shared library dependendencies are inherited across public shared
     // library boundaries.
     //
@@ -824,24 +825,37 @@ void Target::PullDependentTargetLibsFrom(const Target* dep, bool is_public) {
     // resolved by the compiler.
     inherited_libraries_.AppendPublicSharedLibraries(dep->inherited_libraries(),
                                                      is_public);
-  } else if (!dep->IsFinal()) {
-    // The current target isn't linked, so propagate linked deps and
-    // libraries up the dependency tree.
-    inherited_libraries_.AppendInherited(dep->inherited_libraries(), is_public);
-    rust_transitive_libs_.AppendInherited(dep->rust_transitive_libs_,
-                                          is_public);
-  } else if (dep->complete_static_lib()) {
-    // Inherit only final targets through _complete_ static libraries.
-    //
-    // Inherited final libraries aren't linked into complete static libraries.
-    // They are forwarded here so that targets that depend on complete
-    // static libraries can link them in. Conversely, since complete static
-    // libraries link in non-final targets they shouldn't be inherited.
-    for (const auto& inherited :
-         dep->inherited_libraries().GetOrderedAndPublicFlag()) {
-      if (inherited.first->IsFinal()) {
-        inherited_libraries_.Append(inherited.first,
-                                    is_public && inherited.second);
+  } else {
+    InheritedLibraries transitive;
+
+    if (!dep->IsFinal()) {
+      // The current target isn't linked, so propagate linked deps and
+      // libraries up the dependency tree.
+      for (const auto& [inherited, inherited_is_public] :
+           dep->inherited_libraries().GetOrderedAndPublicFlag()) {
+        transitive.Append(inherited, is_public && inherited_is_public);
+      }
+    } else if (dep->complete_static_lib()) {
+      // Inherit only final targets through _complete_ static libraries.
+      //
+      // Inherited final libraries aren't linked into complete static libraries.
+      // They are forwarded here so that targets that depend on complete
+      // static libraries can link them in. Conversely, since complete static
+      // libraries link in non-final targets they shouldn't be inherited.
+      for (const auto& [inherited, inherited_is_public] :
+           dep->inherited_libraries().GetOrderedAndPublicFlag()) {
+        if (inherited->IsFinal()) {
+          transitive.Append(inherited, is_public && inherited_is_public);
+        }
+      }
+    }
+
+    for (const auto& [target, pub] : transitive.GetOrderedAndPublicFlag()) {
+      // Proc macros are not linked into targets that depend on them, so do not
+      // get inherited; they are consumed by the Rust compiler and only need to
+      // be specified in --extern.
+      if (target->output_type() != RUST_PROC_MACRO) {
+        inherited_libraries_.Append(target, pub);
       }
     }
   }
@@ -879,7 +893,7 @@ void Target::PullRecursiveHardDeps() {
     // by the current target).
     if (pair.ptr->IsBinary() && !pair.ptr->all_headers_public() &&
         pair.ptr->public_headers().empty() &&
-        !pair.ptr->swift_values().builds_module()) {
+        !pair.ptr->builds_swift_module()) {
       continue;
     }
 
@@ -1072,19 +1086,24 @@ bool Target::ResolvePrecompiledHeaders(Err* err) {
       // Already have a precompiled header values, the settings must match.
       if (config_values_->precompiled_header() != cur.precompiled_header() ||
           config_values_->precompiled_source() != cur.precompiled_source()) {
+        bool with_toolchain = settings()->ShouldShowToolchain({
+          &label(),
+          pch_header_settings_from,
+          &config->label(),
+        });
         *err = Err(
             defined_from(), "Precompiled header setting conflict.",
-            "The target " + label().GetUserVisibleName(false) +
+            "The target " + label().GetUserVisibleName(with_toolchain) +
                 "\n"
                 "has conflicting precompiled header settings.\n"
                 "\n"
                 "From " +
-                pch_header_settings_from->GetUserVisibleName(false) +
+                pch_header_settings_from->GetUserVisibleName(with_toolchain) +
                 "\n  header: " + config_values_->precompiled_header() +
                 "\n  source: " + config_values_->precompiled_source().value() +
                 "\n\n"
                 "From " +
-                config->label().GetUserVisibleName(false) +
+                config->label().GetUserVisibleName(with_toolchain) +
                 "\n  header: " + cur.precompiled_header() +
                 "\n  source: " + cur.precompiled_source().value());
         return false;
@@ -1121,7 +1140,7 @@ bool Target::CheckSourceSetLanguages(Err* err) const {
   if (output_type() == Target::SOURCE_SET &&
       source_types_used().RustSourceUsed()) {
     *err = Err(defined_from(), "source_set contained Rust code.",
-               label().GetUserVisibleName(false) +
+               label().GetUserVisibleName(!settings()->is_default()) +
                    " has Rust code. Only C/C++ source_sets are supported.");
     return false;
   }
@@ -1167,7 +1186,7 @@ bool Target::CheckAssertNoDeps(Err* err) const {
                                   &failure_path_str, &failure_pattern)) {
     *err = Err(
         defined_from(), "assert_no_deps failed.",
-        label().GetUserVisibleName(false) +
+        label().GetUserVisibleName(!settings()->is_default()) +
             " has an assert_no_deps entry:\n  " + failure_pattern->Describe() +
             "\nwhich fails for the dependency path:\n" + failure_path_str);
     return false;
diff --git a/gn/src/gn/target.h b/gn/src/gn/target.h
index d88f0a57a7a..c965d1bd500 100644
--- a/gn/src/gn/target.h
+++ b/gn/src/gn/target.h
@@ -239,7 +239,7 @@ class Target : public Item {
     return output_type_ == ACTION || output_type_ == ACTION_FOREACH ||
            output_type_ == COPY_FILES || output_type_ == CREATE_BUNDLE ||
            output_type_ == BUNDLE_DATA || output_type_ == GENERATED_FILE ||
-           (IsBinary() && has_swift_values() && swift_values().builds_module());
+           builds_swift_module();
   }
 
   // Returns the iterator range which can be used in range-based for loops
@@ -294,6 +294,10 @@ class Target : public Item {
     return allow_circular_includes_from_;
   }
 
+  // Pool option
+  const LabelPtrPair<Pool>& pool() const { return pool_; }
+  void set_pool(LabelPtrPair<Pool> pool) { pool_ = std::move(pool); }
+
   const InheritedLibraries& inherited_libraries() const {
     return inherited_libraries_;
   }
@@ -311,14 +315,22 @@ class Target : public Item {
   const SwiftValues& swift_values() const;
   bool has_swift_values() const { return swift_values_.get(); }
 
+  // Return true if this targets builds a SwiftModule
+  bool builds_swift_module() const {
+    return IsBinary() && has_swift_values() &&
+           source_types_used().SwiftSourceUsed();
+  }
+
   RustValues& rust_values();
   const RustValues& rust_values() const;
   bool has_rust_values() const { return rust_values_.get(); }
 
   // Transitive closure of libraries that are depended on by this target
-  InheritedLibraries& rust_transitive_libs() { return rust_transitive_libs_; }
-  const InheritedLibraries& rust_transitive_libs() const {
-    return rust_transitive_libs_;
+  const InheritedLibraries& rust_transitive_inherited_libs() const {
+    return rust_transitive_inherited_libs_;
+  }
+  const InheritedLibraries& rust_transitive_inheritable_libs() const {
+    return rust_transitive_inheritable_libs_;
   }
 
   const UniqueVector<SourceDir>& all_lib_dirs() const { return all_lib_dirs_; }
@@ -487,6 +499,8 @@ class Target : public Item {
 
   std::set<Label> allow_circular_includes_from_;
 
+  LabelPtrPair<Pool> pool_;
+
   // Static libraries, shared libraries, and source sets from transitive deps
   // that need to be linked.
   InheritedLibraries inherited_libraries_;
@@ -520,8 +534,18 @@ class Target : public Item {
   // Used for Rust targets.
   std::unique_ptr<RustValues> rust_values_;
 
-  // Used by all targets, only useful to generate Rust targets though.
-  InheritedLibraries rust_transitive_libs_;
+  // Used by all targets, only useful to generate Rust targets though. These
+  // present 2 different views of the public flags:
+  //
+  // Lists all transitive libraries, and for each one the public bit says if
+  // there is a public chain such that this target can make direct use of the
+  // lib. For each library marked public: "I have access to these targets."
+  InheritedLibraries rust_transitive_inherited_libs_;
+  // Lists all transitive libraries, and for each one the public bit says if a
+  // target depending on this target would inherit the libraries as public too.
+  // For each library marked public: "If you depend on me, you get access to
+  // these targets."
+  InheritedLibraries rust_transitive_inheritable_libs_;
 
   // User for Swift targets.
   std::unique_ptr<SwiftValues> swift_values_;
diff --git a/gn/src/gn/target_public_pair.h b/gn/src/gn/target_public_pair.h
new file mode 100644
index 00000000000..f211a81bf43
--- /dev/null
+++ b/gn/src/gn/target_public_pair.h
@@ -0,0 +1,131 @@
+// Copyright 2022 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef TOOLS_GN_TARGET_PUBLIC_PAIR_H_
+#define TOOLS_GN_TARGET_PUBLIC_PAIR_H_
+
+#include "gn/unique_vector.h"
+
+class Target;
+
+// C++ and Rust target resolution requires computing uniquified and
+// ordered lists of static/shared libraries that are collected through
+// the target's dependency tree.
+//
+// Maintaining the order is important to ensure the libraries are linked
+// in the correct order in the final link command line.
+//
+// Also each library must only appear once in the final list, even though
+// it may appear multiple times during the dependency tree walk, either as
+// a "private" or "public" dependency.
+//
+// The TargetPublicPair class below encodes a (target_ptr, is_public_flag)
+// pair, with convenience accessors and utility structs.
+//
+// The TargetPublicPairListBuilder is a builder-pattern class that generates
+// a unique vector of TargetPublicPair values (i.e. the final list described
+// above), and supporting the special logic required to build these lists
+// (see the comments for its Append() and AppendInherited() methods).
+//
+// A convenience encoding for a (target_ptr, is_public_flag) pair.
+class TargetPublicPair {
+ public:
+  TargetPublicPair() = default;
+  TargetPublicPair(const Target* target, bool is_public)
+      : target_(target), is_public_(is_public) {}
+  TargetPublicPair(std::pair<const Target*, bool> pair)
+      : target_(pair.first), is_public_(pair.second) {}
+
+  const Target* target() const { return target_; }
+  void set_target(const Target* target) { target_ = target; }
+
+  bool is_public() const { return is_public_; }
+  void set_is_public(bool is_public) { is_public_ = is_public; }
+
+  // Utility structs that can be used to instantiante containers
+  // that only use the target for lookups / comparisons. E.g.
+  //
+  //   std::unordered_set<TargetPublicPair,
+  //                      TargetPublicPair::TargetHash,
+  //                      TargetPublicPair::TargetEqualTo>
+  //
+  //   std::set<TargetPublicPair, TargetPublicPair::TargetLess>
+  //
+  struct TargetHash {
+    size_t operator()(TargetPublicPair p) const noexcept {
+      return std::hash<const Target*>()(p.target());
+    }
+  };
+
+  struct TargetEqualTo {
+    bool operator()(TargetPublicPair a, TargetPublicPair b) const noexcept {
+      return a.target() == b.target();
+    }
+  };
+
+  struct TargetLess {
+    bool operator()(TargetPublicPair a, TargetPublicPair b) const noexcept {
+      return a.target() < b.target();
+    }
+  };
+
+ private:
+  const Target* target_ = nullptr;
+  bool is_public_ = false;
+};
+
+// A helper type to build a uniquified ordered vector of TargetPublicPair
+// instances. Usage is:
+//
+//   1) Create builder instance.
+//
+//   2) Call Append() to add a direct dependency, or AppendInherited() to add
+//      transitive ones, as many times as necessary.
+//
+//   3) Call Build() to retrieve final list as a vector.
+//
+class TargetPublicPairListBuilder
+    : public UniqueVector<TargetPublicPair,
+                          TargetPublicPair::TargetHash,
+                          TargetPublicPair::TargetEqualTo> {
+ public:
+  // Add (target, is_public) to the list being constructed. If the target
+  // was not already in the list, record the |is_public| flag as is,
+  // otherwise, set the recorded flag to true only if |is_public| is true, or
+  // don't do anything otherwise.
+  void Append(const Target* target, bool is_public) {
+    auto ret = EmplaceBackWithIndex(target, is_public);
+    if (!ret.first && is_public) {
+      // UniqueVector<T>::operator[]() always returns a const reference
+      // because the returned values are lookup keys in its set-like data
+      // structure (thus modifying them would break its internal consistency).
+      // However, because TargetHash and TargetEqualTo are being used to
+      // instantiate this template, only the target() part of the value must
+      // remain constant, and it is possible to modify the is_public() part
+      // in-place safely.
+      auto* pair = const_cast<TargetPublicPair*>(&(*this)[ret.second]);
+      pair->set_is_public(true);
+    }
+  }
+
+  // Append all pairs from any container with begin() and end() iterators
+  // that dereference to values that convert to a TargetPublicPair value.
+  // If |is_public| is false, the input pair will be appended with the
+  // value of the public flag to false.
+  template <
+      typename C,
+      typename = std::void_t<
+          decltype(static_cast<TargetPublicPair>(*std::declval<C>().begin())),
+          decltype(static_cast<TargetPublicPair>(*std::declval<C>().end()))>>
+  void AppendInherited(const C& other, bool is_public) {
+    for (const auto& pair : other) {
+      Append(pair.target(), is_public && pair.is_public());
+    }
+  }
+
+  // Build and return the final list to the caller.
+  std::vector<TargetPublicPair> Build() { return release(); }
+};
+
+#endif  // TOOLS_GN_TARGET_PUBLIC_PAIR_H_
diff --git a/gn/src/gn/target_public_pair_unittest.cc b/gn/src/gn/target_public_pair_unittest.cc
new file mode 100644
index 00000000000..8b08a0c5b3c
--- /dev/null
+++ b/gn/src/gn/target_public_pair_unittest.cc
@@ -0,0 +1,54 @@
+// Copyright 2022 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "gn/target_public_pair.h"
+#include "util/test/test.h"
+
+TEST(TargetPublicPairTest, ConstructionAndMutation) {
+  // Fake target pointer values.
+  const auto* a_target = reinterpret_cast<const Target*>(1000);
+  const auto* b_target = reinterpret_cast<const Target*>(2000);
+
+  TargetPublicPair a_pair(a_target, true);
+  EXPECT_EQ(a_target, a_pair.target());
+  EXPECT_TRUE(a_pair.is_public());
+
+  TargetPublicPair b_pair(b_target, false);
+  EXPECT_EQ(b_target, b_pair.target());
+  EXPECT_FALSE(b_pair.is_public());
+
+  a_pair.set_target(b_target);
+  EXPECT_EQ(b_target, a_pair.target());
+  EXPECT_TRUE(a_pair.is_public());
+
+  a_pair.set_is_public(false);
+  EXPECT_EQ(b_target, a_pair.target());
+  EXPECT_FALSE(a_pair.is_public());
+
+  a_pair = TargetPublicPair(a_target, true);
+  EXPECT_EQ(a_target, a_pair.target());
+  EXPECT_TRUE(a_pair.is_public());
+
+  b_pair = std::move(a_pair);
+  EXPECT_EQ(a_target, b_pair.target());
+  EXPECT_TRUE(b_pair.is_public());
+}
+
+TEST(TargetPublicPairTest, Builder) {
+  const auto* a_target = reinterpret_cast<const Target*>(1000);
+  const auto* b_target = reinterpret_cast<const Target*>(2000);
+  TargetPublicPairListBuilder builder;
+
+  builder.Append(a_target, false);
+  builder.Append(b_target, false);
+  builder.Append(a_target, true);
+  builder.Append(b_target, false);
+
+  auto list = builder.Build();
+  EXPECT_EQ(2u, list.size());
+  EXPECT_EQ(a_target, list[0].target());
+  EXPECT_EQ(b_target, list[1].target());
+  EXPECT_TRUE(list[0].is_public());
+  EXPECT_FALSE(list[1].is_public());
+}
diff --git a/gn/src/gn/target_unittest.cc b/gn/src/gn/target_unittest.cc
index b4ea699077b..005335d3a35 100644
--- a/gn/src/gn/target_unittest.cc
+++ b/gn/src/gn/target_unittest.cc
@@ -926,7 +926,7 @@ TEST_F(TargetTest, CheckStampFileName) {
                                              &computed_outputs, &err));
   ASSERT_EQ(1u, computed_outputs.size());
   EXPECT_EQ("//out/Debug/obj/a/a.stamp", computed_outputs[0].value())
-    << "was instead: " << computed_outputs[0].value();
+      << "was instead: " << computed_outputs[0].value();
 }
 
 // Tests Target::GetOutputFilesForSource for action_foreach targets (these, like
@@ -1219,13 +1219,16 @@ TEST_F(TargetTest, ResolvePrecompiledHeaders) {
   TestWithScope setup;
   Err err;
 
-  Target target(setup.settings(), Label(SourceDir("//foo/"), "bar"));
+  Target target(setup.settings(), Label(SourceDir("//foo/"), "bar",
+                                        SourceDir("//toolchain/"), "default"));
 
   // Target with no settings, no configs, should be a no-op.
   EXPECT_TRUE(target.ResolvePrecompiledHeaders(&err));
 
   // Config with PCH values.
-  Config config_1(setup.settings(), Label(SourceDir("//foo/"), "c1"));
+  Config config_1(
+      setup.settings(),
+      Label(SourceDir("//foo/"), "c1", SourceDir("//toolchain/"), "default"));
   std::string pch_1("pch.h");
   SourceFile pcs_1("//pcs.cc");
   config_1.own_values().set_precompiled_header(pch_1);
@@ -1246,7 +1249,9 @@ TEST_F(TargetTest, ResolvePrecompiledHeaders) {
   EXPECT_TRUE(target.config_values().precompiled_source() == pcs_1);
 
   // Second config with different PCH values.
-  Config config_2(setup.settings(), Label(SourceDir("//foo/"), "c2"));
+  Config config_2(
+      setup.settings(),
+      Label(SourceDir("//foo/"), "c2", SourceDir("//toolchain/"), "default"));
   std::string pch_2("pch2.h");
   SourceFile pcs_2("//pcs2.cc");
   config_2.own_values().set_precompiled_header(pch_2);
diff --git a/gn/src/gn/template.cc b/gn/src/gn/template.cc
index f0eca28df14..d2c6fc65e90 100644
--- a/gn/src/gn/template.cc
+++ b/gn/src/gn/template.cc
@@ -64,6 +64,10 @@ Value Template::Invoke(Scope* scope,
   Scope template_scope(closure_.get());
   template_scope.set_source_dir(scope->GetSourceDir());
 
+  // Track the invocation of the template on the template's scope
+  template_scope.SetTemplateInvocationEntry(
+      template_name, args[0].string_value(), invocation->GetRange().begin());
+
   // Propagate build dependency files from invoker scope (template scope already
   // propagated via parent scope).
   template_scope.AddBuildDependencyFiles(
@@ -112,13 +116,21 @@ Value Template::Invoke(Scope* scope,
   invoker_value = template_scope.GetMutableValue(variables::kInvoker,
                                                  Scope::SEARCH_NESTED, false);
   if (invoker_value && invoker_value->type() == Value::SCOPE) {
-    if (!invoker_value->scope_value()->CheckForUnusedVars(err))
+    if (!invoker_value->scope_value()->CheckForUnusedVars(err)) {
+      // If there was an error, append the caller location so the error message
+      // displays a stack trace of how it got here.
+      err->AppendSubErr(Err(invocation, "whence it was called."));
       return Value();
+    }
   }
 
   // Check for unused variables in the template itself.
-  if (!template_scope.CheckForUnusedVars(err))
+  if (!template_scope.CheckForUnusedVars(err)) {
+    // If there was an error, append the caller location so the error message
+    // displays a stack trace of how it got here.
+    err->AppendSubErr(Err(invocation, "whence it was called."));
     return Value();
+  }
 
   return result;
 }
diff --git a/gn/src/gn/tool.cc b/gn/src/gn/tool.cc
index bf3aba61a0f..684dc3e34ea 100644
--- a/gn/src/gn/tool.cc
+++ b/gn/src/gn/tool.cc
@@ -4,6 +4,7 @@
 
 #include "gn/tool.h"
 
+#include "gn/builtin_tool.h"
 #include "gn/c_tool.h"
 #include "gn/general_tool.h"
 #include "gn/rust_tool.h"
@@ -52,6 +53,13 @@ const RustTool* Tool::AsRust() const {
   return nullptr;
 }
 
+BuiltinTool* Tool::AsBuiltin() {
+  return nullptr;
+}
+const BuiltinTool* Tool::AsBuiltin() const {
+  return nullptr;
+}
+
 bool Tool::IsPatternInOutputList(const SubstitutionList& output_list,
                                  const SubstitutionPattern& pattern) const {
   for (const auto& cur : output_list.list()) {
@@ -342,7 +350,7 @@ const char* Tool::GetToolTypeForSourceType(SourceFile::Type type) {
 
 // static
 const char* Tool::GetToolTypeForTargetFinalOutput(const Target* target) {
-  // The contents of this list might be surprising (i.e. stamp tool for copy
+  // The contents of this list might be surprising (i.e. phony tool for copy
   // rules). See the header for why.
   // TODO(crbug.com/gn/39): Don't emit stamp files for single-output targets.
   if (target->source_types_used().RustSourceUsed()) {
@@ -366,8 +374,6 @@ const char* Tool::GetToolTypeForTargetFinalOutput(const Target* target) {
     }
   }
   switch (target->output_type()) {
-    case Target::GROUP:
-      return GeneralTool::kGeneralToolStamp;
     case Target::EXECUTABLE:
       return CTool::kCToolLink;
     case Target::SHARED_LIBRARY:
@@ -376,15 +382,19 @@ const char* Tool::GetToolTypeForTargetFinalOutput(const Target* target) {
       return CTool::kCToolSolinkModule;
     case Target::STATIC_LIBRARY:
       return CTool::kCToolAlink;
-    case Target::SOURCE_SET:
-      return GeneralTool::kGeneralToolStamp;
     case Target::ACTION:
     case Target::ACTION_FOREACH:
     case Target::BUNDLE_DATA:
-    case Target::CREATE_BUNDLE:
     case Target::COPY_FILES:
+    case Target::CREATE_BUNDLE:
     case Target::GENERATED_FILE:
-      return GeneralTool::kGeneralToolStamp;
+    case Target::GROUP:
+    case Target::SOURCE_SET:
+      if (target->settings()->build_settings()->no_stamp_files()) {
+        return BuiltinTool::kBuiltinToolPhony;
+      } else {
+        return GeneralTool::kGeneralToolStamp;
+      }
     default:
       NOTREACHED();
       return kToolNone;
diff --git a/gn/src/gn/tool.h b/gn/src/gn/tool.h
index 1e01af7778e..b95c64ba7bd 100644
--- a/gn/src/gn/tool.h
+++ b/gn/src/gn/tool.h
@@ -23,6 +23,7 @@ class Toolchain;
 class CTool;
 class GeneralTool;
 class RustTool;
+class BuiltinTool;
 
 // To add a new Tool category, create a subclass implementing SetComplete()
 // Add a new category to ToolCategories
@@ -62,6 +63,8 @@ class Tool {
   virtual const GeneralTool* AsGeneral() const;
   virtual RustTool* AsRust();
   virtual const RustTool* AsRust() const;
+  virtual BuiltinTool* AsBuiltin();
+  virtual const BuiltinTool* AsBuiltin() const;
 
   // Basic information ---------------------------------------------------------
 
@@ -233,6 +236,7 @@ class Tool {
                                           Err* err);
 
   static const char* GetToolTypeForSourceType(SourceFile::Type type);
+
   static const char* GetToolTypeForTargetFinalOutput(const Target* target);
 
  protected:
diff --git a/gn/src/gn/toolchain.cc b/gn/src/gn/toolchain.cc
index bfad81db635..a65618466cd 100644
--- a/gn/src/gn/toolchain.cc
+++ b/gn/src/gn/toolchain.cc
@@ -9,13 +9,19 @@
 #include <utility>
 
 #include "base/logging.h"
+#include "gn/builtin_tool.h"
+#include "gn/settings.h"
 #include "gn/target.h"
 #include "gn/value.h"
 
 Toolchain::Toolchain(const Settings* settings,
                      const Label& label,
                      const SourceFileSet& build_dependency_files)
-    : Item(settings, label, build_dependency_files) {}
+    : Item(settings, label, build_dependency_files) {
+  // Ensure "phony" tool is part of all toolchains by default.
+  const char* phony_name = BuiltinTool::kBuiltinToolPhony;
+  tools_.emplace(phony_name, std::make_unique<BuiltinTool>(phony_name));
+}
 
 Toolchain::~Toolchain() = default;
 
@@ -87,6 +93,20 @@ const RustTool* Toolchain::GetToolAsRust(const char* name) const {
   return nullptr;
 }
 
+BuiltinTool* Toolchain::GetToolAsBuiltin(const char* name) {
+  if (Tool* tool = GetTool(name)) {
+    return tool->AsBuiltin();
+  }
+  return nullptr;
+}
+
+const BuiltinTool* Toolchain::GetToolAsBuiltin(const char* name) const {
+  if (const Tool* tool = GetTool(name)) {
+    return tool->AsBuiltin();
+  }
+  return nullptr;
+}
+
 void Toolchain::SetTool(std::unique_ptr<Tool> t) {
   DCHECK(t->name() != Tool::kToolNone);
   DCHECK(tools_.find(t->name()) == tools_.end());
@@ -120,6 +140,11 @@ const RustTool* Toolchain::GetToolForSourceTypeAsRust(
   return GetToolAsRust(Tool::GetToolTypeForSourceType(type));
 }
 
+const BuiltinTool* Toolchain::GetToolForSourceTypeAsBuiltin(
+    SourceFile::Type type) const {
+  return GetToolAsBuiltin(Tool::GetToolTypeForSourceType(type));
+}
+
 const Tool* Toolchain::GetToolForTargetFinalOutput(const Target* target) const {
   return GetTool(Tool::GetToolTypeForTargetFinalOutput(target));
 }
@@ -138,3 +163,8 @@ const RustTool* Toolchain::GetToolForTargetFinalOutputAsRust(
     const Target* target) const {
   return GetToolAsRust(Tool::GetToolTypeForTargetFinalOutput(target));
 }
+
+const BuiltinTool* Toolchain::GetToolForTargetFinalOutputAsBuiltin(
+    const Target* target) const {
+  return GetToolAsBuiltin(Tool::GetToolTypeForTargetFinalOutput(target));
+}
diff --git a/gn/src/gn/toolchain.h b/gn/src/gn/toolchain.h
index eb5a60c526e..270fada797f 100644
--- a/gn/src/gn/toolchain.h
+++ b/gn/src/gn/toolchain.h
@@ -16,6 +16,8 @@
 #include "gn/tool.h"
 #include "gn/value.h"
 
+class BuiltinTool;
+
 // Holds information on a specific toolchain. This data is filled in when we
 // encounter a toolchain definition.
 //
@@ -62,6 +64,8 @@ class Toolchain : public Item {
   const CTool* GetToolAsC(const char* name) const;
   RustTool* GetToolAsRust(const char* name);
   const RustTool* GetToolAsRust(const char* name) const;
+  BuiltinTool* GetToolAsBuiltin(const char* name);
+  const BuiltinTool* GetToolAsBuiltin(const char* name) const;
 
   // Set a tool. When all tools are configured, you should call
   // ToolchainSetupComplete().
@@ -93,6 +97,7 @@ class Toolchain : public Item {
   const CTool* GetToolForSourceTypeAsC(SourceFile::Type type) const;
   const GeneralTool* GetToolForSourceTypeAsGeneral(SourceFile::Type type) const;
   const RustTool* GetToolForSourceTypeAsRust(SourceFile::Type type) const;
+  const BuiltinTool* GetToolForSourceTypeAsBuiltin(SourceFile::Type type) const;
 
   // Returns the tool that produces the final output for the given target type.
   // This isn't necessarily the tool you would expect. For copy target, this
@@ -103,6 +108,8 @@ class Toolchain : public Item {
   const GeneralTool* GetToolForTargetFinalOutputAsGeneral(
       const Target* target) const;
   const RustTool* GetToolForTargetFinalOutputAsRust(const Target* target) const;
+  const BuiltinTool* GetToolForTargetFinalOutputAsBuiltin(
+      const Target* target) const;
 
   const SubstitutionBits& substitution_bits() const {
     DCHECK(setup_complete_);
diff --git a/gn/src/gn/trace.cc b/gn/src/gn/trace.cc
index c6eeed2d64d..bc3f50e6881 100644
--- a/gn/src/gn/trace.cc
+++ b/gn/src/gn/trace.cc
@@ -30,18 +30,25 @@ class TraceLog {
   TraceLog() { events_.reserve(16384); }
   // Trace items leaked intentionally.
 
-  void Add(TraceItem* item) {
+  void Add(std::unique_ptr<TraceItem> item) {
     std::lock_guard<std::mutex> lock(lock_);
-    events_.push_back(item);
+    events_.push_back(std::move(item));
   }
 
   // Returns a copy for threadsafety.
-  std::vector<TraceItem*> events() const { return events_; }
+  std::vector<TraceItem*> events() const {
+    std::vector<TraceItem*> events;
+    std::lock_guard<std::mutex> lock(lock_);
+    events.reserve(events_.size());
+    for (const auto& e : events_)
+      events.push_back(e.get());
+    return events;
+  }
 
  private:
-  std::mutex lock_;
+  mutable std::mutex lock_;
 
-  std::vector<TraceItem*> events_;
+  std::vector<std::unique_ptr<TraceItem>> events_;
 
   TraceLog(const TraceLog&) = delete;
   TraceLog& operator=(const TraceLog&) = delete;
@@ -120,18 +127,17 @@ TraceItem::TraceItem(Type type,
 TraceItem::~TraceItem() = default;
 
 ScopedTrace::ScopedTrace(TraceItem::Type t, const std::string& name)
-    : item_(nullptr), done_(false) {
+    : done_(false) {
   if (trace_log) {
-    item_ = new TraceItem(t, name, std::this_thread::get_id());
+    item_ = std::make_unique<TraceItem>(t, name, std::this_thread::get_id());
     item_->set_begin(TicksNow());
   }
 }
 
-ScopedTrace::ScopedTrace(TraceItem::Type t, const Label& label)
-    : item_(nullptr), done_(false) {
+ScopedTrace::ScopedTrace(TraceItem::Type t, const Label& label) : done_(false) {
   if (trace_log) {
-    item_ = new TraceItem(t, label.GetUserVisibleName(false),
-                          std::this_thread::get_id());
+    item_ = std::make_unique<TraceItem>(t, label.GetUserVisibleName(false),
+                                        std::this_thread::get_id());
     item_->set_begin(TicksNow());
   }
 }
@@ -155,7 +161,7 @@ void ScopedTrace::Done() {
     done_ = true;
     if (trace_log) {
       item_->set_end(TicksNow());
-      AddTrace(item_);
+      AddTrace(std::move(item_));
     }
   }
 }
@@ -169,8 +175,8 @@ bool TracingEnabled() {
   return !!trace_log;
 }
 
-void AddTrace(TraceItem* item) {
-  trace_log->Add(item);
+void AddTrace(std::unique_ptr<TraceItem> item) {
+  trace_log->Add(std::move(item));
 }
 
 std::string SummarizeTraces() {
@@ -244,19 +250,27 @@ void SaveTraces(const base::FilePath& file_name) {
 
   std::string quote_buffer;  // Allocate outside loop to prevent reallocationg.
 
+  // Trace viewer doesn't handle integer > 2^53 well, so re-numbering them to
+  // small numbers.
+  std::map<std::thread::id, int> tidmap;
+  std::vector<TraceItem*> events = trace_log->events();
+  for (const auto* item : events) {
+    int id = tidmap.size();
+    tidmap.emplace(item->thread_id(), id);
+  }
+
   // Write main thread metadata (assume this is being written on the main
   // thread).
-  out << "{\"pid\":0,\"tid\":\"" << std::this_thread::get_id() << "\"";
+  out << "{\"pid\":0,\"tid\":\"" << tidmap[std::this_thread::get_id()] << "\"";
   out << ",\"ts\":0,\"ph\":\"M\",";
   out << "\"name\":\"thread_name\",\"args\":{\"name\":\"Main thread\"}},";
 
-  std::vector<TraceItem*> events = trace_log->events();
   for (size_t i = 0; i < events.size(); i++) {
     const TraceItem& item = *events[i];
 
     if (i != 0)
       out << ",";
-    out << "{\"pid\":0,\"tid\":\"" << item.thread_id() << "\"";
+    out << "{\"pid\":0,\"tid\":\"" << tidmap[item.thread_id()] << "\"";
     out << ",\"ts\":" << item.begin() / kNanosecondsToMicroseconds;
     out << ",\"ph\":\"X\"";  // "X" = complete event with begin & duration.
     out << ",\"dur\":" << item.delta().InMicroseconds();
diff --git a/gn/src/gn/trace.h b/gn/src/gn/trace.h
index b89e82a1ab6..b59cd34ed41 100644
--- a/gn/src/gn/trace.h
+++ b/gn/src/gn/trace.h
@@ -5,6 +5,7 @@
 #ifndef TOOLS_GN_TRACE_H_
 #define TOOLS_GN_TRACE_H_
 
+#include <memory>
 #include <string>
 #include <thread>
 
@@ -80,7 +81,7 @@ class ScopedTrace {
   void Done();
 
  private:
-  TraceItem* item_;
+  std::unique_ptr<TraceItem> item_;
   bool done_;
 };
 
@@ -90,8 +91,8 @@ void EnableTracing();
 // Returns whether tracing is enabled.
 bool TracingEnabled();
 
-// Adds a trace event to the log. Takes ownership of the pointer.
-void AddTrace(TraceItem* item);
+// Adds a trace event to the log.
+void AddTrace(std::unique_ptr<TraceItem> item);
 
 // Returns a summary of the current traces, or the empty string if tracing is
 // not enabled.
diff --git a/gn/src/gn/unique_vector.h b/gn/src/gn/unique_vector.h
index 0f6994fe447..473786d4a0e 100644
--- a/gn/src/gn/unique_vector.h
+++ b/gn/src/gn/unique_vector.h
@@ -186,11 +186,28 @@ class UniqueVector {
       push_back(*i);
   }
 
-  // Append another vector into this one.
-  void Append(const UniqueVector& other) {
+  // Append from any iterable container with begin() and end()
+  // methods, whose iterators derefence to values convertible to T.
+  template <typename C,
+            typename = std::void_t<
+                decltype(static_cast<const T>(*std::declval<C>().begin())),
+                decltype(static_cast<const T>(*std::declval<C>().end()))>>
+  void Append(const C& other) {
     Append(other.begin(), other.end());
   }
 
+  // Append from any moveable iterable container with begin() and
+  // end() methods. This variant moves items from the container
+  // into the UniqueVector instance.
+  template <typename C,
+            typename = std::void_t<
+                decltype(static_cast<T>(*std::declval<C>().begin())),
+                decltype(static_cast<T>(*std::declval<C>().end()))>>
+  void Append(C&& other) {
+    for (auto it = other.begin(); it != other.end(); ++it)
+      push_back(std::move(*it));
+  }
+
   // Returns true if the item is already in the vector.
   bool Contains(const T& t) const {
     size_t hash;
diff --git a/gn/src/gn/variables.cc b/gn/src/gn/variables.cc
index fba20e07ee5..28f174db389 100644
--- a/gn/src/gn/variables.cc
+++ b/gn/src/gn/variables.cc
@@ -561,6 +561,14 @@ const char kArgs_Help[] =
   to the script. Typically you would use source expansion (see "gn help
   source_expansion") to insert the source file names.
 
+  Args can also expand the substitution patterns corresponding to config
+  variables in the same way that compiler tools (see "gn help tool") do. These
+  allow actions that run compiler or compiler-like tools to access the results
+  of propagating configs through the build graph. For example:
+
+  args = [ "{{defines}}", "{{include_dirs}}", "{{rustenv}}", "--input-file",
+           "{{source}}" ]
+
   See also "gn help action" and "gn help action_foreach".
 )";
 
@@ -1104,10 +1112,10 @@ Example
 
     # Locate the depfile in the output directory named like the
     # inputs but with a ".d" appended.
-    depfile = "$relative_target_output_dir/{{source_name}}.d"
+    depfile = "$target_gen_dir/{{source_name_part}}.d"
 
     # Say our script uses "-o <d file>" to indicate the depfile.
-    args = [ "{{source}}", "-o", depfile ]
+    args = [ "{{source}}", "-o", rebase_path(depfile, root_build_dir)]
   }
 )";
 
@@ -1634,15 +1642,20 @@ const char kOutputs_Help[] =
 
 const char kPool[] = "pool";
 const char kPool_HelpShort[] =
-    "pool: [string] Label of the pool used by the action.";
+    "pool: [string] Label of the pool used by binary targets and actions.";
 const char kPool_Help[] =
-    R"(pool: Label of the pool used by the action.
+    R"(pool: Label of the pool used by binary targets actions.
 
-  A fully-qualified label representing the pool that will be used for the
-  action. Pools are defined using the pool() {...} declaration.
+  A fully-qualified label representing the pool that will be used for binary
+  targets and actions. Pools are defined using the pool() {...} declaration.
 
 Example
 
+  executable("binary") {
+    pool = "//build:custom_pool"
+    ...
+  }
+
   action("action") {
     pool = "//build:custom_pool"
     ...
diff --git a/gn/src/gn/visibility.cc b/gn/src/gn/visibility.cc
index 08789906ca5..61423ff9534 100644
--- a/gn/src/gn/visibility.cc
+++ b/gn/src/gn/visibility.cc
@@ -92,9 +92,14 @@ bool Visibility::CheckItemVisibility(const Item* from,
                                      const Item* to,
                                      Err* err) {
   if (!to->visibility().CanSeeMe(from->label())) {
-    std::string to_label = to->label().GetUserVisibleName(false);
+    bool with_toolchain = from->settings()->ShouldShowToolchain({
+        &to->label(),
+        &from->label(),
+    });
+    std::string to_label = to->label().GetUserVisibleName(with_toolchain);
+    std::string from_label = from->label().GetUserVisibleName(with_toolchain);
     *err = Err(from->defined_from(), "Dependency not allowed.",
-               "The item " + from->label().GetUserVisibleName(false) +
+               "The item " + from_label +
                    "\n"
                    "can not depend on " +
                    to_label +
diff --git a/gn/src/gn/xcode_object.cc b/gn/src/gn/xcode_object.cc
index f3c5a54f95a..4399c55af5c 100644
--- a/gn/src/gn/xcode_object.cc
+++ b/gn/src/gn/xcode_object.cc
@@ -116,6 +116,7 @@ const SourceTypeForExt kSourceTypeForExt[] = {
     {"js", "sourcecode.javascript"},
     {"kext", "wrapper.kext"},
     {"m", "sourcecode.c.objc"},
+    {"md", "net.daringfireball.markdown"},
     {"mm", "sourcecode.cpp.objcpp"},
     {"nib", "wrapper.nib"},
     {"o", "compiled.mach-o.objfile"},
@@ -131,14 +132,15 @@ const SourceTypeForExt kSourceTypeForExt[] = {
     {"storyboard", "file.storyboard"},
     {"strings", "text.plist.strings"},
     {"swift", "sourcecode.swift"},
+    {"ts", "sourcecode.javascript"},
     {"ttf", "file"},
     {"xcassets", "folder.assetcatalog"},
     {"xcconfig", "text.xcconfig"},
     {"xcdatamodel", "wrapper.xcdatamodel"},
     {"xcdatamodeld", "wrapper.xcdatamodeld"},
     {"xctest", "wrapper.cfbundle"},
-    {"xpc", "wrapper.xpc-service"},
     {"xib", "file.xib"},
+    {"xpc", "wrapper.xpc-service"},
     {"y", "sourcecode.yacc"},
 };
 
@@ -152,7 +154,7 @@ const char* GetSourceType(std::string_view ext) {
 }
 
 bool HasExplicitFileType(std::string_view ext) {
-  return ext == "dart";
+  return ext == "dart" || ext == "ts";
 }
 
 bool IsSourceFileForIndexing(std::string_view ext) {
@@ -253,19 +255,26 @@ void PrintProperty(std::ostream& out,
 struct PBXGroupComparator {
   using PBXObjectPtr = std::unique_ptr<PBXObject>;
   bool operator()(const PBXObjectPtr& lhs, const PBXObjectPtr& rhs) {
+    if (lhs.get() == rhs.get())
+      return false;
+
+    // Ensure that PBXGroup that should sort last are sorted last.
+    const bool lhs_sort_last = SortLast(lhs);
+    const bool rhs_sort_last = SortLast(rhs);
+    if (lhs_sort_last != rhs_sort_last)
+      return rhs_sort_last;
+
     if (lhs->Class() != rhs->Class())
       return rhs->Class() < lhs->Class();
 
-    if (lhs->Class() == PBXGroupClass) {
-      PBXGroup* lhs_group = static_cast<PBXGroup*>(lhs.get());
-      PBXGroup* rhs_group = static_cast<PBXGroup*>(rhs.get());
-      return lhs_group->name() < rhs_group->name();
-    }
+    return lhs->Name() < rhs->Name();
+  }
 
-    DCHECK_EQ(lhs->Class(), PBXFileReferenceClass);
-    PBXFileReference* lhs_file = static_cast<PBXFileReference*>(lhs.get());
-    PBXFileReference* rhs_file = static_cast<PBXFileReference*>(rhs.get());
-    return lhs_file->Name() < rhs_file->Name();
+  bool SortLast(const PBXObjectPtr& ptr) {
+    if (ptr->Class() != PBXGroupClass)
+      return false;
+
+    return static_cast<PBXGroup*>(ptr.get())->SortLast();
   }
 };
 }  // namespace
@@ -380,10 +389,10 @@ void PBXBuildPhase::Visit(PBXObjectVisitorConst& visitor) const {
 
 PBXTarget::PBXTarget(const std::string& name,
                      const std::string& shell_script,
-                     const std::string& config_name,
+                     const std::vector<std::string>& configs,
                      const PBXAttributes& attributes)
     : configurations_(
-          std::make_unique<XCConfigurationList>(config_name, attributes, this)),
+          std::make_unique<XCConfigurationList>(configs, attributes, this)),
       name_(name) {
   if (!shell_script.empty()) {
     build_phases_.push_back(
@@ -424,9 +433,9 @@ void PBXTarget::Visit(PBXObjectVisitorConst& visitor) const {
 
 PBXAggregateTarget::PBXAggregateTarget(const std::string& name,
                                        const std::string& shell_script,
-                                       const std::string& config_name,
+                                       const std::vector<std::string>& configs,
                                        const PBXAttributes& attributes)
-    : PBXTarget(name, shell_script, config_name, attributes) {}
+    : PBXTarget(name, shell_script, configs, attributes) {}
 
 PBXAggregateTarget::~PBXAggregateTarget() = default;
 
@@ -534,10 +543,9 @@ void PBXFileReference::Print(std::ostream& out, unsigned indent) const {
     PrintProperty(out, rules, "includeInIndex", 0u);
   } else {
     std::string_view ext = FindExtension(&name_);
-    if (HasExplicitFileType(ext))
-      PrintProperty(out, rules, "explicitFileType", GetSourceType(ext));
-    else
-      PrintProperty(out, rules, "lastKnownFileType", GetSourceType(ext));
+    const char* prop_name =
+        HasExplicitFileType(ext) ? "explicitFileType" : "lastKnownFileType";
+    PrintProperty(out, rules, prop_name, GetSourceType(ext));
   }
 
   if (!name_.empty() && name_ != path_)
@@ -586,6 +594,7 @@ PBXFileReference* PBXGroup::AddSourceFile(const std::string& navigator_path,
                                           const std::string& source_path) {
   DCHECK(!navigator_path.empty());
   DCHECK(!source_path.empty());
+
   std::string::size_type sep = navigator_path.find("/");
   if (sep == std::string::npos) {
     // Prevent same file reference being created and added multiple times.
@@ -596,12 +605,12 @@ PBXFileReference* PBXGroup::AddSourceFile(const std::string& navigator_path,
       PBXFileReference* child_as_file_reference =
           static_cast<PBXFileReference*>(child.get());
       if (child_as_file_reference->Name() == navigator_path &&
-          child_as_file_reference->path() == source_path) {
+          child_as_file_reference->path() == navigator_path) {
         return child_as_file_reference;
       }
     }
 
-    return CreateChild<PBXFileReference>(navigator_path, source_path,
+    return CreateChild<PBXFileReference>(navigator_path, navigator_path,
                                          std::string());
   }
 
@@ -660,40 +669,59 @@ void PBXGroup::Print(std::ostream& out, unsigned indent) const {
   out << indent_str << Reference() << " = {\n";
   PrintProperty(out, rules, "isa", ToString(Class()));
   PrintProperty(out, rules, "children", children_);
-  if (!name_.empty())
+  if (!name_.empty() && name_ != path_)
     PrintProperty(out, rules, "name", name_);
-  if (is_source_ && !path_.empty())
+  if (!path_.empty())
     PrintProperty(out, rules, "path", path_);
   PrintProperty(out, rules, "sourceTree", "<group>");
   out << indent_str << "};\n";
 }
 
+bool PBXGroup::SortLast() const {
+  return false;
+}
+
 PBXObject* PBXGroup::AddChildImpl(std::unique_ptr<PBXObject> child) {
   DCHECK(child);
   DCHECK(child->Class() == PBXGroupClass ||
          child->Class() == PBXFileReferenceClass);
 
-  PBXObject* child_ptr = child.get();
-  if (autosorted()) {
-    auto iter = std::lower_bound(children_.begin(), children_.end(), child,
-                                 PBXGroupComparator());
-    children_.insert(iter, std::move(child));
-  } else {
-    children_.push_back(std::move(child));
-  }
-  return child_ptr;
+  auto iter = std::lower_bound(children_.begin(), children_.end(), child,
+                               PBXGroupComparator());
+  return children_.insert(iter, std::move(child))->get();
+}
+
+// PBXMainGroup ---------------------------------------------------------------
+
+PBXMainGroup::PBXMainGroup(const std::string& source_path)
+    : PBXGroup(source_path, std::string()) {}
+
+PBXMainGroup::~PBXMainGroup() = default;
+
+std::string PBXMainGroup::Name() const {
+  return std::string();
+}
+
+// PBXProductsGroup -----------------------------------------------------------
+
+PBXProductsGroup::PBXProductsGroup() : PBXGroup(std::string(), "Products") {}
+
+PBXProductsGroup::~PBXProductsGroup() = default;
+
+bool PBXProductsGroup::SortLast() const {
+  return true;
 }
 
 // PBXNativeTarget ------------------------------------------------------------
 
 PBXNativeTarget::PBXNativeTarget(const std::string& name,
                                  const std::string& shell_script,
-                                 const std::string& config_name,
+                                 const std::vector<std::string>& configs,
                                  const PBXAttributes& attributes,
                                  const std::string& product_type,
                                  const std::string& product_name,
                                  const PBXFileReference* product_reference)
-    : PBXTarget(name, shell_script, config_name, attributes),
+    : PBXTarget(name, shell_script, configs, attributes),
       product_reference_(product_reference),
       product_type_(product_type),
       product_name_(product_name) {
@@ -746,20 +774,15 @@ void PBXNativeTarget::Print(std::ostream& out, unsigned indent) const {
 // PBXProject -----------------------------------------------------------------
 
 PBXProject::PBXProject(const std::string& name,
-                       const std::string& config_name,
+                       std::vector<std::string> configs,
                        const std::string& source_path,
                        const PBXAttributes& attributes)
-    : name_(name), config_name_(config_name), target_for_indexing_(nullptr) {
-  main_group_ = std::make_unique<PBXGroup>();
-  main_group_->set_autosorted(false);
-
-  sources_ = main_group_->CreateChild<PBXGroup>(source_path, "Source");
-  sources_->set_is_source(true);
-
-  products_ = main_group_->CreateChild<PBXGroup>(std::string(), "Products");
+    : name_(name), configs_(std::move(configs)), target_for_indexing_(nullptr) {
+  main_group_ = std::make_unique<PBXMainGroup>(source_path);
+  products_ = main_group_->CreateChild<PBXProductsGroup>();
 
   configurations_ =
-      std::make_unique<XCConfigurationList>(config_name, attributes, this);
+      std::make_unique<XCConfigurationList>(configs_, attributes, this);
 }
 
 PBXProject::~PBXProject() = default;
@@ -777,7 +800,7 @@ void PBXProject::AddSourceFile(const std::string& navigator_path,
                                const std::string& source_path,
                                PBXNativeTarget* target) {
   PBXFileReference* file_reference =
-      sources_->AddSourceFile(navigator_path, source_path);
+      main_group_->AddSourceFile(navigator_path, source_path);
   std::string_view ext = FindExtension(&source_path);
   if (!IsSourceFileForIndexing(ext))
     return;
@@ -787,15 +810,16 @@ void PBXProject::AddSourceFile(const std::string& navigator_path,
 }
 
 void PBXProject::AddAggregateTarget(const std::string& name,
+                                    const std::string& output_dir,
                                     const std::string& shell_script) {
   PBXAttributes attributes;
   attributes["CLANG_ENABLE_OBJC_WEAK"] = "YES";
   attributes["CODE_SIGNING_REQUIRED"] = "NO";
-  attributes["CONFIGURATION_BUILD_DIR"] = ".";
+  attributes["CONFIGURATION_BUILD_DIR"] = output_dir;
   attributes["PRODUCT_NAME"] = name;
 
   targets_.push_back(std::make_unique<PBXAggregateTarget>(
-      name, shell_script, config_name_, attributes));
+      name, shell_script, configs_, attributes));
 }
 
 void PBXProject::AddIndexingTarget() {
@@ -804,7 +828,7 @@ void PBXProject::AddIndexingTarget() {
   attributes["CLANG_ENABLE_OBJC_WEAK"] = "YES";
   attributes["CODE_SIGNING_REQUIRED"] = "NO";
   attributes["EXECUTABLE_PREFIX"] = "";
-  attributes["HEADER_SEARCH_PATHS"] = sources_->path();
+  attributes["HEADER_SEARCH_PATHS"] = main_group_->path();
   attributes["PRODUCT_NAME"] = "sources";
 
   PBXFileReference* product_reference =
@@ -813,8 +837,8 @@ void PBXProject::AddIndexingTarget() {
 
   const char product_type[] = "com.apple.product-type.tool";
   targets_.push_back(std::make_unique<PBXNativeTarget>(
-      "sources", std::string(), config_name_, attributes, product_type,
-      "sources", product_reference));
+      "sources", std::string(), configs_, attributes, product_type, "sources",
+      product_reference));
   target_for_indexing_ = static_cast<PBXNativeTarget*>(targets_.back().get());
 }
 
@@ -851,7 +875,7 @@ PBXNativeTarget* PBXProject::AddNativeTarget(
   attributes["EXCLUDED_SOURCE_FILE_NAMES"] = "*.*";
 
   targets_.push_back(std::make_unique<PBXNativeTarget>(
-      name, shell_script, config_name_, attributes, output_type, product_name,
+      name, shell_script, configs_, attributes, output_type, product_name,
       product));
   return static_cast<PBXNativeTarget*>(targets_.back().get());
 }
@@ -913,6 +937,7 @@ void PBXProject::Print(std::ostream& out, unsigned indent) const {
   PrintProperty(out, rules, "knownRegions",
                 std::vector<std::string>({"en", "Base"}));
   PrintProperty(out, rules, "mainGroup", main_group_);
+  PrintProperty(out, rules, "productRefGroup", products_);
   PrintProperty(out, rules, "projectDirPath", project_dir_path_);
   PrintProperty(out, rules, "projectRoot", project_root_);
   PrintProperty(out, rules, "targets", targets_);
@@ -967,13 +992,14 @@ void PBXShellScriptBuildPhase::Print(std::ostream& out, unsigned indent) const {
   const IndentRules rules = {false, indent + 1};
   out << indent_str << Reference() << " = {\n";
   PrintProperty(out, rules, "isa", ToString(Class()));
+  PrintProperty(out, rules, "alwaysOutOfDate", 1u);
   PrintProperty(out, rules, "buildActionMask", 0x7fffffffu);
   PrintProperty(out, rules, "files", files_);
   PrintProperty(out, rules, "inputPaths", EmptyPBXObjectVector());
   PrintProperty(out, rules, "name", name_);
   PrintProperty(out, rules, "outputPaths", EmptyPBXObjectVector());
   PrintProperty(out, rules, "runOnlyForDeploymentPostprocessing", 0u);
-  PrintProperty(out, rules, "shellPath", "/usr/bin/python3");
+  PrintProperty(out, rules, "shellPath", "/bin/sh");
   PrintProperty(out, rules, "shellScript", shell_script_);
   PrintProperty(out, rules, "showEnvVarsInLog", 0u);
   out << indent_str << "};\n";
@@ -1067,13 +1093,16 @@ void XCBuildConfiguration::Print(std::ostream& out, unsigned indent) const {
 
 // XCConfigurationList --------------------------------------------------------
 
-XCConfigurationList::XCConfigurationList(const std::string& name,
-                                         const PBXAttributes& attributes,
-                                         const PBXObject* owner_reference)
+XCConfigurationList::XCConfigurationList(
+    const std::vector<std::string>& configs,
+    const PBXAttributes& attributes,
+    const PBXObject* owner_reference)
     : owner_reference_(owner_reference) {
   DCHECK(owner_reference_);
-  configurations_.push_back(
-      std::make_unique<XCBuildConfiguration>(name, attributes));
+  for (const std::string& config_name : configs) {
+    configurations_.push_back(
+        std::make_unique<XCBuildConfiguration>(config_name, attributes));
+  }
 }
 
 XCConfigurationList::~XCConfigurationList() = default;
@@ -1110,7 +1139,7 @@ void XCConfigurationList::Print(std::ostream& out, unsigned indent) const {
   out << indent_str << Reference() << " = {\n";
   PrintProperty(out, rules, "isa", ToString(Class()));
   PrintProperty(out, rules, "buildConfigurations", configurations_);
-  PrintProperty(out, rules, "defaultConfigurationIsVisible", 1u);
+  PrintProperty(out, rules, "defaultConfigurationIsVisible", 0u);
   PrintProperty(out, rules, "defaultConfigurationName",
                 configurations_[0]->Name());
   out << indent_str << "};\n";
diff --git a/gn/src/gn/xcode_object.h b/gn/src/gn/xcode_object.h
index e29eb3d6c08..076e9937d28 100644
--- a/gn/src/gn/xcode_object.h
+++ b/gn/src/gn/xcode_object.h
@@ -144,7 +144,7 @@ class PBXTarget : public PBXObject {
  public:
   PBXTarget(const std::string& name,
             const std::string& shell_script,
-            const std::string& config_name,
+            const std::vector<std::string>& configs,
             const PBXAttributes& attributes);
   ~PBXTarget() override;
 
@@ -174,7 +174,7 @@ class PBXAggregateTarget : public PBXTarget {
  public:
   PBXAggregateTarget(const std::string& name,
                      const std::string& shell_script,
-                     const std::string& config_name,
+                     const std::vector<std::string>& configs,
                      const PBXAttributes& attributes);
   ~PBXAggregateTarget() override;
 
@@ -284,12 +284,6 @@ class PBXGroup : public PBXObject {
   PBXFileReference* AddSourceFile(const std::string& navigator_path,
                                   const std::string& source_path);
 
-  bool is_source() const { return is_source_; }
-  void set_is_source(bool is_source) { is_source_ = is_source; }
-
-  bool autosorted() const { return autosorted_; }
-  void set_autosorted(bool autosorted) { autosorted_ = autosorted; }
-
   template <typename T, typename... Args>
   T* CreateChild(Args&&... args) {
     return static_cast<T*>(
@@ -303,26 +297,50 @@ class PBXGroup : public PBXObject {
   void Visit(PBXObjectVisitorConst& visitor) const override;
   void Print(std::ostream& out, unsigned indent) const override;
 
+  // Returns whether the current PBXGroup should sort last when sorting
+  // children of a PBXGroup. This should only be used for the "Products"
+  // group which is hidden in Xcode UI when it is the last children of
+  // the main PBXProject group.
+  virtual bool SortLast() const;
+
  private:
   PBXObject* AddChildImpl(std::unique_ptr<PBXObject> child);
 
   std::vector<std::unique_ptr<PBXObject>> children_;
   std::string name_;
   std::string path_;
-  bool is_source_ = false;
-  bool autosorted_ = true;
 
   PBXGroup(const PBXGroup&) = delete;
   PBXGroup& operator=(const PBXGroup&) = delete;
 };
 
+// PBXMainGroup ---------------------------------------------------------------
+
+class PBXMainGroup : public PBXGroup {
+ public:
+  explicit PBXMainGroup(const std::string& source_path);
+  ~PBXMainGroup() override;
+
+  std::string Name() const override;
+};
+
+// PBXProductsGroup -----------------------------------------------------------
+
+class PBXProductsGroup : public PBXGroup {
+ public:
+  explicit PBXProductsGroup();
+  ~PBXProductsGroup() override;
+
+  bool SortLast() const override;
+};
+
 // PBXNativeTarget ------------------------------------------------------------
 
 class PBXNativeTarget : public PBXTarget {
  public:
   PBXNativeTarget(const std::string& name,
                   const std::string& shell_script,
-                  const std::string& config_name,
+                  const std::vector<std::string>& configs,
                   const PBXAttributes& attributes,
                   const std::string& product_type,
                   const std::string& product_name,
@@ -351,7 +369,7 @@ class PBXNativeTarget : public PBXTarget {
 class PBXProject : public PBXObject {
  public:
   PBXProject(const std::string& name,
-             const std::string& config_name,
+             std::vector<std::string> configs,
              const std::string& source_path,
              const PBXAttributes& attributes);
   ~PBXProject() override;
@@ -362,6 +380,7 @@ class PBXProject : public PBXObject {
                      const std::string& source_path,
                      PBXNativeTarget* target);
   void AddAggregateTarget(const std::string& name,
+                          const std::string& output_dir,
                           const std::string& shell_script);
   void AddIndexingTarget();
   PBXNativeTarget* AddNativeTarget(
@@ -393,9 +412,8 @@ class PBXProject : public PBXObject {
   std::string project_root_;
   std::vector<std::unique_ptr<PBXTarget>> targets_;
   std::string name_;
-  std::string config_name_;
+  std::vector<std::string> configs_;
 
-  PBXGroup* sources_ = nullptr;
   PBXGroup* products_ = nullptr;
   PBXNativeTarget* target_for_indexing_ = nullptr;
 
@@ -506,7 +524,7 @@ class XCBuildConfiguration : public PBXObject {
 
 class XCConfigurationList : public PBXObject {
  public:
-  XCConfigurationList(const std::string& name,
+  XCConfigurationList(const std::vector<std::string>& configs,
                       const PBXAttributes& attributes,
                       const PBXObject* owner_reference);
   ~XCConfigurationList() override;
diff --git a/gn/src/gn/xcode_object_unittest.cc b/gn/src/gn/xcode_object_unittest.cc
index 0498c3f1f36..e20a1d0ca5d 100644
--- a/gn/src/gn/xcode_object_unittest.cc
+++ b/gn/src/gn/xcode_object_unittest.cc
@@ -38,7 +38,7 @@ std::unique_ptr<PBXGroup> GetPBXGroupObject() {
 // Instantiate a PBXProject object with arbitrary names.
 std::unique_ptr<PBXProject> GetPBXProjectObject() {
   std::unique_ptr<PBXProject> pbx_project(
-      new PBXProject("project", "config", "out/build", PBXAttributes()));
+      new PBXProject("project", {"config"}, "out/build", PBXAttributes()));
   return pbx_project;
 }
 
@@ -61,7 +61,7 @@ std::unique_ptr<PBXBuildFile> GetPBXBuildFileObject(
 // Instantiate a PBXAggregateTarget object with arbitrary names.
 std::unique_ptr<PBXAggregateTarget> GetPBXAggregateTargetObject() {
   std::unique_ptr<PBXAggregateTarget> pbx_aggregate_target(
-      new PBXAggregateTarget("target_name", "shell_script", "config_name",
+      new PBXAggregateTarget("target_name", "shell_script", {"config_name"},
                              PBXAttributes()));
   return pbx_aggregate_target;
 }
@@ -70,7 +70,7 @@ std::unique_ptr<PBXAggregateTarget> GetPBXAggregateTargetObject() {
 std::unique_ptr<PBXNativeTarget> GetPBXNativeTargetObject(
     const PBXFileReference* product_reference) {
   std::unique_ptr<PBXNativeTarget> pbx_native_target(new PBXNativeTarget(
-      "target_name", "ninja gn_unittests", "config_name", PBXAttributes(),
+      "target_name", "ninja gn_unittests", {"config_name"}, PBXAttributes(),
       "com.apple.product-type.application", "product_name", product_reference));
   return pbx_native_target;
 }
@@ -104,7 +104,7 @@ std::unique_ptr<XCBuildConfiguration> GetXCBuildConfigurationObject() {
 std::unique_ptr<XCConfigurationList> GetXCConfigurationListObject(
     const PBXObject* owner_reference) {
   std::unique_ptr<XCConfigurationList> xc_configuration_list(
-      new XCConfigurationList("config_list_name", PBXAttributes(),
+      new XCConfigurationList({"config_list_name"}, PBXAttributes(),
                               owner_reference));
   return xc_configuration_list;
 }
diff --git a/gn/src/gn/xcode_writer.cc b/gn/src/gn/xcode_writer.cc
index 5e57ec97fb6..2673d3c1859 100644
--- a/gn/src/gn/xcode_writer.cc
+++ b/gn/src/gn/xcode_writer.cc
@@ -11,15 +11,17 @@
 #include <optional>
 #include <sstream>
 #include <string>
+#include <string_view>
 #include <utility>
 
 #include "base/environment.h"
+#include "base/files/file_enumerator.h"
 #include "base/logging.h"
 #include "base/sha1.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
-#include "base/strings/stringprintf.h"
 #include "gn/args.h"
 #include "gn/build_settings.h"
 #include "gn/builder.h"
@@ -40,67 +42,14 @@
 
 namespace {
 
-// This is the template of the script used to build the target. It invokes
-// ninja (supporting --ninja-executable parameter), parsing ninja's output
-// using a regular expression looking for relative path to the source root
-// from root_build_dir that are at the start of a path and converting them
-// to absolute paths (use str.replace(rel_root_src, abs_root_src) would be
-// simpler but would fail if rel_root_src is present multiple time in the
-// path).
-const char kBuildScriptTemplate[] = R"(
-import re
-import os
-import subprocess
-import sys
-
-rel_root_src = '%s'
-abs_root_src = os.path.abspath(rel_root_src) + '/'
-
-build_target = '%s'
-ninja_binary = '%s'
-ninja_params = [ '-C', '.' ]
-
-%s
-
-if build_target:
-  ninja_params.append(build_target)
-  print('Compile "' + build_target + '" via ninja')
-else:
-  print('Compile "all" via ninja')
-
-process = subprocess.Popen(
-    [ ninja_binary ] + ninja_params,
-    stdout=subprocess.PIPE,
-    stderr=subprocess.STDOUT,
-    universal_newlines=True,
-    encoding='utf-8',
-    env=environ)
-
-pattern = re.compile('(?<!/)' + re.escape(rel_root_src))
-
-for line in iter(process.stdout.readline, ''):
-  while True:
-    match = pattern.search(line)
-    if not match:
-      break
-    span = match.span()
-    print(line[:span[0]], end='')
-    print(abs_root_src, end='')
-    line = line[span[1]:]
-  print(line, flush=True, end='')
-
-process.wait()
-
-sys.exit(process.returncode)
-)";
-
 enum TargetOsType {
   WRITER_TARGET_OS_IOS,
   WRITER_TARGET_OS_MACOS,
 };
 
 const char* kXCTestFileSuffixes[] = {
-    "egtest.m", "egtest.mm", "xctest.m", "xctest.mm", "UITests.m", "UITests.mm",
+    "egtest.m",     "egtest.mm", "egtest.swift", "xctest.m",      "xctest.mm",
+    "xctest.swift", "UITests.m", "UITests.mm",   "UITests.swift",
 };
 
 const char kXCTestModuleTargetNamePostfix[] = "_module";
@@ -131,35 +80,50 @@ TargetOsType GetTargetOs(const Args& args) {
   return WRITER_TARGET_OS_MACOS;
 }
 
-std::string GetNinjaExecutable(const std::string& ninja_executable) {
-  return ninja_executable.empty() ? "ninja" : ninja_executable;
-}
-
-std::string ComputeScriptEnviron(base::Environment* environment) {
+std::string GetBuildScript(const std::string& target_name,
+                           const std::string& ninja_executable,
+                           const std::string& build_dir,
+                           base::Environment* environment) {
+  // Launch ninja with a sanitized environment (Xcode sets many environment
+  // variables overridding settings, including the SDK, thus breaking hermetic
+  // build).
   std::stringstream buffer;
-  buffer << "environ = {}";
+  buffer << "exec env -i ";
+
+  // Write environment.
   for (const auto& variable : kSafeEnvironmentVariables) {
-    buffer << "\nenviron['" << variable.name << "'] = ";
+    buffer << variable.name << "=";
     if (variable.capture_at_generation) {
       std::string value;
       environment->GetVar(variable.name, &value);
       buffer << "'" << value << "'";
     } else {
-      buffer << "os.environ.get('" << variable.name << "', '')";
+      buffer << "\"${" << variable.name << "}\"";
     }
+    buffer << " ";
+  }
+
+  if (ninja_executable.empty()) {
+    buffer << "ninja";
+  } else {
+    buffer << ninja_executable;
+  }
+
+  buffer << " -C " << build_dir;
+
+  if (!target_name.empty()) {
+    buffer << " '" << target_name << "'";
   }
   return buffer.str();
 }
 
-std::string GetBuildScript(const std::string& target_name,
+std::string GetBuildScript(const Label& target_label,
                            const std::string& ninja_executable,
-                           const std::string& root_src_dir,
+                           const std::string& build_dir,
                            base::Environment* environment) {
-  std::string environ_script = ComputeScriptEnviron(environment);
-  std::string ninja = GetNinjaExecutable(ninja_executable);
-  return base::StringPrintf(kBuildScriptTemplate, root_src_dir.c_str(),
-                            target_name.c_str(), ninja.c_str(),
-                            environ_script.c_str());
+  std::string target_name = target_label.GetUserVisibleName(false);
+  base::TrimString(target_name, "/", &target_name);
+  return GetBuildScript(target_name, ninja_executable, build_dir, environment);
 }
 
 bool IsApplicationTarget(const Target* target) {
@@ -241,6 +205,49 @@ void AddPBXTargetDependency(const PBXTarget* base_pbxtarget,
   dependent_pbxtarget->AddDependency(std::move(dependency));
 }
 
+// Returns a SourceFile for absolute path `file_path` below `//`.
+SourceFile FilePathToSourceFile(const BuildSettings* build_settings,
+                                const base::FilePath& file_path) {
+  const std::string file_path_utf8 = FilePathToUTF8(file_path);
+  return SourceFile("//" + file_path_utf8.substr(
+                               build_settings->root_path_utf8().size() + 1));
+}
+
+// Returns the list of patterns to use when looking for additional files
+// from `options`.
+std::vector<base::FilePath::StringType> GetAdditionalFilesPatterns(
+    const XcodeWriter::Options& options) {
+  return base::SplitString(options.additional_files_patterns,
+                           FILE_PATH_LITERAL(";"), base::TRIM_WHITESPACE,
+                           base::SPLIT_WANT_ALL);
+}
+
+// Returns the list of roots to use when looking for additional files
+// from `options`.
+std::vector<base::FilePath> GetAdditionalFilesRoots(
+    const BuildSettings* build_settings,
+    const XcodeWriter::Options& options) {
+  if (options.additional_files_roots.empty()) {
+    return {build_settings->root_path()};
+  }
+
+  const std::vector<base::FilePath::StringType> roots =
+      base::SplitString(options.additional_files_roots, FILE_PATH_LITERAL(";"),
+                        base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
+
+  std::vector<base::FilePath> root_paths;
+  for (const base::FilePath::StringType& root : roots) {
+    const std::string rebased_root =
+        RebasePath(FilePathToUTF8(root), SourceDir("//"),
+                   build_settings->root_path_utf8());
+
+    root_paths.push_back(
+        build_settings->root_path().Append(UTF8ToFilePath(rebased_root)));
+  }
+
+  return root_paths;
+}
+
 // Helper class to resolve list of XCTest files per target.
 //
 // Uses a cache of file found per intermediate targets to reduce the need
@@ -373,21 +380,17 @@ void RecursivelyAssignIds(PBXProject* project) {
   project->Visit(visitor);
 }
 
-// Returns a configuration name derived from the build directory. This gives
-// standard names if using the Xcode convention of naming the build directory
-// out/$configuration-$platform (e.g. out/Debug-iphonesimulator).
-std::string ConfigNameFromBuildSettings(const BuildSettings* build_settings) {
-  std::string config_name = FilePathToUTF8(build_settings->build_dir()
-                                               .Resolve(base::FilePath())
-                                               .StripTrailingSeparators()
-                                               .BaseName());
-
-  std::string::size_type separator = config_name.find('-');
-  if (separator != std::string::npos)
-    config_name = config_name.substr(0, separator);
-
-  DCHECK(!config_name.empty());
-  return config_name;
+// Returns a list of configuration names from the options passed to the
+// generator. If no configuration names have been passed, return default
+// value.
+std::vector<std::string> ConfigListFromOptions(const std::string& configs) {
+  std::vector<std::string> result = base::SplitString(
+      configs, ";", base::KEEP_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
+
+  if (result.empty())
+    result.push_back(std::string("Release"));
+
+  return result;
 }
 
 // Returns the path to root_src_dir from settings.
@@ -600,6 +603,10 @@ class XcodeProject {
       const std::map<const Target*, PBXNativeTarget*>& bundle_targets,
       Err* err);
 
+  // Tweak `output_dir` to be relative to the configuration specific output
+  // directory (see --xcode-config-build-dir=... flag).
+  std::string GetConfigOutputDir(std::string_view output_dir);
+
   // Generates the content of the .xcodeproj file into |out|.
   void WriteFileContent(std::ostream& out) const;
 
@@ -616,7 +623,7 @@ XcodeProject::XcodeProject(const BuildSettings* build_settings,
     : build_settings_(build_settings),
       options_(options),
       project_(options.project_name,
-               ConfigNameFromBuildSettings(build_settings),
+               ConfigListFromOptions(options.configurations),
                SourcePathFromBuildSettings(build_settings),
                ProjectAttributesFromBuildSettings(build_settings)) {}
 
@@ -685,14 +692,34 @@ bool XcodeProject::AddSourcesFromBuilder(const Builder& builder, Err* err) {
     if (!build_settings_->root_path().IsParent(path))
       continue;
 
-    const std::string as8bit = path.As8Bit();
-    const SourceFile source(
-        "//" + as8bit.substr(build_settings_->root_path().value().size() + 1));
-
+    const SourceFile source = FilePathToSourceFile(build_settings_, path);
     if (ShouldIncludeFileInProject(source))
       sources.insert(source);
   }
 
+  // Add any files from --xcode-additional-files-patterns, using the root
+  // listed in --xcode-additional-files-roots.
+  if (!options_.additional_files_patterns.empty()) {
+    const std::vector<base::FilePath::StringType> patterns =
+        GetAdditionalFilesPatterns(options_);
+    const std::vector<base::FilePath> roots =
+        GetAdditionalFilesRoots(build_settings_, options_);
+
+    for (const base::FilePath& root : roots) {
+      for (const base::FilePath::StringType& pattern : patterns) {
+        base::FileEnumerator it(root, /*recursive*/ true,
+                                base::FileEnumerator::FILES, pattern,
+                                base::FileEnumerator::FolderSearchPolicy::ALL);
+
+        for (base::FilePath path = it.Next(); !path.empty(); path = it.Next()) {
+          const SourceFile source = FilePathToSourceFile(build_settings_, path);
+          if (ShouldIncludeFileInProject(source))
+            sources.insert(source);
+        }
+      }
+    }
+  }
+
   // Sort files to ensure deterministic generation of the project file (and
   // nicely sorted file list in Xcode).
   std::vector<SourceFile> sorted_sources(sources.begin(), sources.end());
@@ -711,11 +738,10 @@ bool XcodeProject::AddSourcesFromBuilder(const Builder& builder, Err* err) {
 bool XcodeProject::AddTargetsFromBuilder(const Builder& builder, Err* err) {
   std::unique_ptr<base::Environment> env(base::Environment::Create());
 
-  const std::string root_src_dir =
-      RebasePath("//", build_settings_->build_dir());
-  project_.AddAggregateTarget("All", GetBuildScript(options_.root_target_name,
-                                                    options_.ninja_executable,
-                                                    root_src_dir, env.get()));
+  project_.AddAggregateTarget(
+      "All", GetConfigOutputDir("."),
+      GetBuildScript(options_.root_target_name, options_.ninja_executable,
+                     GetConfigOutputDir("."), env.get()));
 
   const std::optional<std::vector<const Target*>> targets =
       GetTargetsFromBuilder(builder, err);
@@ -946,15 +972,13 @@ PBXNativeTarget* XcodeProject::AddBinaryTarget(const Target* target,
     output_dir = RebasePath(output_dir, build_settings_->build_dir());
   }
 
-  const std::string root_src_dir =
-      RebasePath("//", build_settings_->build_dir());
   return project_.AddNativeTarget(
       target->label().name(), "compiled.mach-o.executable",
       target->output_name().empty() ? target->label().name()
                                     : target->output_name(),
-      "com.apple.product-type.tool", output_dir,
-      GetBuildScript(target->label().name(), options_.ninja_executable,
-                     root_src_dir, env));
+      "com.apple.product-type.tool", GetConfigOutputDir(output_dir),
+      GetBuildScript(target->label(), options_.ninja_executable,
+                     GetConfigOutputDir("."), env));
 }
 
 PBXNativeTarget* XcodeProject::AddBundleTarget(const Target* target,
@@ -978,19 +1002,33 @@ PBXNativeTarget* XcodeProject::AddBundleTarget(const Target* target,
   const std::string& target_output_name = RebasePath(
       target->bundle_data().GetBundleRootDirOutput(target->settings()).value(),
       build_settings_->build_dir());
+
   const std::string output_dir =
       RebasePath(target->bundle_data().GetBundleDir(target->settings()).value(),
                  build_settings_->build_dir());
-  const std::string root_src_dir =
-      RebasePath("//", build_settings_->build_dir());
+
   return project_.AddNativeTarget(
       pbxtarget_name, std::string(), target_output_name,
-      target->bundle_data().product_type(), output_dir,
-      GetBuildScript(pbxtarget_name, options_.ninja_executable, root_src_dir,
-                     env),
+      target->bundle_data().product_type(), GetConfigOutputDir(output_dir),
+      GetBuildScript(target->label(), options_.ninja_executable,
+                     GetConfigOutputDir("."), env),
       xcode_extra_attributes);
 }
 
+std::string XcodeProject::GetConfigOutputDir(std::string_view output_dir) {
+  if (options_.configuration_build_dir.empty())
+    return std::string(output_dir);
+
+  base::FilePath config_output_dir(options_.configuration_build_dir);
+  if (output_dir != ".") {
+    config_output_dir = config_output_dir.Append(UTF8ToFilePath(output_dir));
+  }
+
+  return RebasePath(FilePathToUTF8(config_output_dir.StripTrailingSeparators()),
+                    build_settings_->build_dir(),
+                    build_settings_->root_path_utf8());
+}
+
 void XcodeProject::WriteFileContent(std::ostream& out) const {
   out << "// !$*UTF8*$!\n"
       << "{\n"
diff --git a/gn/src/gn/xcode_writer.h b/gn/src/gn/xcode_writer.h
index 96ed14fe876..9c960e5ec70 100644
--- a/gn/src/gn/xcode_writer.h
+++ b/gn/src/gn/xcode_writer.h
@@ -11,6 +11,8 @@
 #include <string>
 #include <vector>
 
+#include "base/files/file_path.h"
+
 class Builder;
 class BuildSettings;
 class Err;
@@ -42,6 +44,30 @@ class XcodeWriter {
     // files for those target will still be listed in the generated project).
     std::string dir_filters_string;
 
+    // If specified, should be a semicolon-separated list of configuration
+    // names. It will be used to generate all the configuration variations
+    // in the project. If empty, the project is assumed to only use a single
+    // configuration "Release".
+    std::string configurations;
+
+    // If specified, should be the path for the configuration's build
+    // directory. It can use Xcode variables such as ${CONFIGURATION} or
+    // ${EFFECTIVE_PLATFORM_NAME}. If empty, it is assumed to be the same
+    // as the project directory.
+    base::FilePath configuration_build_dir;
+
+    // If specified, should be a semicolon-separated list of file patterns.
+    // It will be used to add files to the project that are not referenced
+    // from the BUILD.gn files. This is usually used to add documentation
+    // files.
+    base::FilePath::StringType additional_files_patterns;
+
+    // If specified, should be a semicolon-separated list of file roots.
+    // It will be used to add files to the project that are not referenced
+    // from the BUILD.gn files. This is usually used to add documentation
+    // files.
+    base::FilePath::StringType additional_files_roots;
+
     // Control which version of the build system should be used for the
     // generated Xcode project.
     XcodeBuildSystem build_system = XcodeBuildSystem::kLegacy;
diff --git a/gn/src/util/atomic_write.cc b/gn/src/util/atomic_write.cc
new file mode 100644
index 00000000000..51130d33273
--- /dev/null
+++ b/gn/src/util/atomic_write.cc
@@ -0,0 +1,34 @@
+// Copyright (c) 2022 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "util/atomic_write.h"
+
+#include "base/files/file_util.h"
+
+namespace util {
+
+int WriteFileAtomically(const base::FilePath& filename,
+                        const char* data,
+                        int size) {
+  base::FilePath dir = filename.DirName();
+  base::FilePath temp_file_path;
+
+  {
+    base::File temp_file =
+        base::CreateAndOpenTemporaryFileInDir(dir, &temp_file_path);
+    if (!temp_file.IsValid()) {
+      return -1;
+    }
+    if (temp_file.WriteAtCurrentPos(data, size) != size) {
+      return -1;
+    }
+  }
+
+  if (!base::ReplaceFile(temp_file_path, filename, NULL)) {
+    return -1;
+  }
+  return size;
+}
+
+}  // namespace util
diff --git a/gn/src/util/atomic_write.h b/gn/src/util/atomic_write.h
new file mode 100644
index 00000000000..232917ac48e
--- /dev/null
+++ b/gn/src/util/atomic_write.h
@@ -0,0 +1,22 @@
+// Copyright (c) 2022 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef TOOLS_GN_ATOMIC_WRITE_H_
+#define TOOLS_GN_ATOMIC_WRITE_H_
+
+#include "base/files/file_path.h"
+
+namespace util {
+
+// Writes the given buffer into the file, overwriting any data that was
+// previously there. The write is performed atomically by first writing the
+// contents to a temporary file and then moving it into place. Returns the
+// number of bytes written, or -1 on error.
+int WriteFileAtomically(const base::FilePath& filename,
+                        const char* data,
+                        int size);
+
+}  // namespace util
+
+#endif  // TOOLS_GN_ATOMIC_WRITE_H_
diff --git a/gn/src/util/atomic_write_unittest.cc b/gn/src/util/atomic_write_unittest.cc
new file mode 100644
index 00000000000..c1d3372ae0c
--- /dev/null
+++ b/gn/src/util/atomic_write_unittest.cc
@@ -0,0 +1,36 @@
+// Copyright 2022 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "util/atomic_write.h"
+
+#include <string>
+
+#include "base/files/file_util.h"
+#include "base/files/scoped_temp_dir.h"
+#include "util/test/test.h"
+
+class ImportantFileWriterTest : public testing::Test {
+ public:
+  ImportantFileWriterTest() = default;
+  void SetUp() override {
+    ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
+    file_ = temp_dir_.GetPath().AppendASCII("test-file");
+  }
+
+ protected:
+  base::FilePath file_;
+
+ private:
+  base::ScopedTempDir temp_dir_;
+};
+
+// Test that WriteFileAtomically works.
+TEST_F(ImportantFileWriterTest, Basic) {
+  const std::string data = "Test string for writing.";
+  EXPECT_FALSE(base::PathExists(file_));
+  EXPECT_TRUE(util::WriteFileAtomically(file_, data.data(), data.size()));
+  std::string actual;
+  EXPECT_TRUE(ReadFileToString(file_, &actual));
+  EXPECT_EQ(data, actual);
+}
diff --git a/gn/src/util/worker_pool.cc b/gn/src/util/worker_pool.cc
index 9f6a47b38af..f594699ddd0 100644
--- a/gn/src/util/worker_pool.cc
+++ b/gn/src/util/worker_pool.cc
@@ -53,7 +53,7 @@ void ProcessorGroupSetter::SetProcessorGroup(std::thread* thread) {
 
 int GetThreadCount() {
   std::string thread_count =
-      base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+      base::CommandLine::ForCurrentProcess()->GetSwitchValueString(
           switches::kThreads);
 
   // See if an override was specified on the command line.
diff --git a/gn/tools/update_reference.sh b/gn/tools/update_reference.sh
new file mode 100755
index 00000000000..50427e1157d
--- /dev/null
+++ b/gn/tools/update_reference.sh
@@ -0,0 +1,12 @@
+#!/bin/sh
+
+# Check for the existance of the AUTHORS file as an easy way to determine if
+# it's being run from the correct directory.
+if test -f "AUTHORS"; then
+    echo Building gn...
+    ninja -C out gn
+    echo Generating new docs/reference.md...
+    out/gn help --markdown all > docs/reference.md
+else
+    echo Please run this command from the GN checkout root directory.
+fi
author	Michal Klocek <michal.klocek@qt.io>	2023-06-03 07:33:02 +0200
committer	Michal Klocek <michal.klocek@qt.io>	2023-07-06 14:33:05 +0000
commit	266cfa0fb83513250bcefd8234e0916c195a4b2e (patch)
tree	762d08bbe1280c7e4b6324dbb53aae04477faa5a
parent	b5eefeb8ec4af885f132e9bb71e64192d719309b (diff)