Teach LIT2 how to run Clang tests in the objdir for srcdir != objdir builds.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@81472 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 53 insertions, 0 deletions

diff --git a/test/lit.cfg b/test/lit.cfg
index dcda2ab378..0b8e12bf0d 100644
--- a/test/lit.cfg
+++ b/test/lit.cfg
@@ -1,6 +1,8 @@
 # -*- Python -*-
 
 def config_new():
+    import os
+
     # Configuration file for the 'lit' test runner.
 
     # name: The name of this test suite.
@@ -16,6 +18,57 @@ def config_new():
     # suffixes: A list of file extensions to treat as test files.
     config.suffixes = ['.c', '.cpp', '.m', '.mm']
 
+    # test_source_root: The root path where tests are located.
+    config.test_source_root = os.path.dirname(__file__)
+
+    # test_exec_root: The root path where tests should be run.
+    clang_obj_root = getattr(config, 'clang_obj_root', None)
+    if clang_obj_root is not None:
+        config.test_exec_root = os.path.join(clang_obj_root, 'test')
+
+    ###
+
+    # Check that the object root is known.
+    if config.test_exec_root is None:
+        # Otherwise, we haven't loaded the site specific configuration (the user is
+        # probably trying to run on a test file directly, and either the site
+        # configuration hasn't been created by the build system, or we are in an
+        # out-of-tree build situation).
+
+        # Try to detect the situation where we are using an out-of-tree build by
+        # looking for 'llvm-config'.
+        #
+        # FIXME: I debated (i.e., wrote and threw away) adding logic to
+        # automagically generate the lit.site.cfg if we are in some kind of fresh
+        # build situation. This means knowing how to invoke the build system
+        # though, and I decided it was too much magic.
+
+        llvm_config = lit.util.which('llvm-config', config.environment['PATH'])
+        if not llvm_config:
+            lit.fatal('No site specific configuration available!')
+
+        # Get the source and object roots.
+        llvm_src_root = lit.util.capture(['llvm-config', '--src-root']).strip()
+        llvm_obj_root = lit.util.capture(['llvm-config', '--obj-root']).strip()
+        clang_src_root = os.path.join(llvm_src_root, "tools", "clang")
+        clang_obj_root = os.path.join(llvm_obj_root, "tools", "clang")
+
+        # Validate that we got a tree which points to here, using the standard
+        # tools/clang layout.
+        this_src_root = os.path.dirname(config.test_source_root)
+        if os.path.realpath(clang_src_root) != os.path.realpath(this_src_root):
+            lit.fatal('No site specific configuration available!')
+
+        # Check that the site specific configuration exists.
+        site_cfg = os.path.join(clang_obj_root, 'test', 'lit.site.cfg')
+        if not os.path.exists(site_cfg):
+            lit.fatal('No site specific configuration available!')
+
+        # Okay, that worked. Notify the user of the automagic, and reconfigure.
+        lit.note('using out-of-tree build at %r' % clang_obj_root)
+        lit.load_config(config, site_cfg)
+        raise SystemExit
+
     ###
 
     # Discover the 'clang' and 'clangcc' to use.