Reapply [VFS] Skip non existent files from the VFS tree

Reapply r278457 with test fixed to not abouse fs case sensitivity.

When the VFS uses a YAML file, the real file path for a
virtual file is described in the "external-contents" field. Example:

  ...
  {
     'type': 'file',
     'name': 'a.h',
     'external-contents': '/a/b/c/a.h'
  }

Currently, when parsing umbrella directories, we use
vfs::recursive_directory_iterator to gather the header files to generate the
equivalent modules for. If the external contents for a header does not exist,
we currently are unable to build a module, since the VFS
vfs::recursive_directory_iterator will fail when it finds an entry without a
reliable real path.

Since the YAML file could be prepared ahead of time and shared among
different compiler invocations, an entry might not yet have a reliable
path in 'external-contents', breaking the iteration.

Give the VFS the capability to skip such entries whenever
'ignore-non-existent-contents' property is set in the YAML file.

rdar://problem/27531549

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@278543 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 62 insertions, 0 deletions

diff --git a/test/VFS/Inputs/Bar.framework/Headers/A.h b/test/VFS/Inputs/Bar.framework/Headers/A.h
new file mode 100644
index 0000000000..975f1f0437
--- /dev/null
+++ b/test/VFS/Inputs/Bar.framework/Headers/A.h
@@ -0,0 +1 @@
+// A.h
diff --git a/test/VFS/Inputs/Bar.framework/Headers/B.h b/test/VFS/Inputs/Bar.framework/Headers/B.h
new file mode 100644
index 0000000000..761540b09c
--- /dev/null
+++ b/test/VFS/Inputs/Bar.framework/Headers/B.h
@@ -0,0 +1 @@
+// B.h
diff --git a/test/VFS/Inputs/Bar.framework/Headers/C.h b/test/VFS/Inputs/Bar.framework/Headers/C.h
new file mode 100644
index 0000000000..a0121d46b4
--- /dev/null
+++ b/test/VFS/Inputs/Bar.framework/Headers/C.h
@@ -0,0 +1 @@
+// C.h
diff --git a/test/VFS/Inputs/Bar.framework/Modules/module.modulemap b/test/VFS/Inputs/Bar.framework/Modules/module.modulemap
new file mode 100644
index 0000000000..d5c759aceb
--- /dev/null
+++ b/test/VFS/Inputs/Bar.framework/Modules/module.modulemap
@@ -0,0 +1,6 @@
+framework module Bar [extern_c] {
+  umbrella "Headers"
+  export *
+  module * { export * }
+}
+
diff --git a/test/VFS/Inputs/bar-headers.yaml b/test/VFS/Inputs/bar-headers.yaml
new file mode 100644
index 0000000000..846d55cc9e
--- /dev/null
+++ b/test/VFS/Inputs/bar-headers.yaml
@@ -0,0 +1,39 @@
+{
+  'version': 0,
+  'case-sensitive': 'false',
+  'ignore-non-existent-contents': 'true',
+  'roots': [
+    {
+      'type': 'directory',
+      'name': "VDIR/Bar.framework/Headers",
+      'contents': [
+        {
+          'type': 'file',
+          'name': "A.h",
+          'external-contents': "OUT_DIR/Bar.framework/Headers/A.h"
+        },
+        {
+          'type': 'file',
+          'name': "B.h",
+          'external-contents': "OUT_DIR/Bar.framework/Headers/B.h"
+        },
+        {
+          'type': 'file',
+          'name': "C.h",
+          'external-contents': "OUT_DIR/Bar.framework/Headers/C.h"
+        }
+      ]
+    },
+    {
+      'type': 'directory',
+      'name': "VDIR/Bar.framework/Modules",
+      'contents': [
+        {
+          'type': 'file',
+          'name': "module.modulemap",
+          'external-contents': "OUT_DIR/Bar.framework/Modules/module.modulemap"
+        }
+      ]
+    },
+  ]
+}
diff --git a/test/VFS/umbrella-framework-import-skipnonexist.m b/test/VFS/umbrella-framework-import-skipnonexist.m
new file mode 100644
index 0000000000..5c7cd6d9db
--- /dev/null
+++ b/test/VFS/umbrella-framework-import-skipnonexist.m
@@ -0,0 +1,14 @@
+// REQUIRES: crash-recovery, shell
+
+// FIXME: This XFAIL is cargo-culted from crash-report.c. Do we need it?
+// XFAIL: mingw32
+
+// RUN: rm -rf %t
+// RUN: mkdir -p %t/vdir %t/outdir %t/cache
+// RUN: cp -a %S/Inputs/Bar.framework %t/outdir/
+//
+// RUN: sed -e "s:VDIR:%t/vdir:g" -e "s:OUT_DIR:%t/outdir:g" %S/Inputs/bar-headers.yaml > %t/vdir/bar-headers.yaml
+// RUN: rm -f %t/outdir/Bar.framework/Headers/B.h
+// RUN: %clang_cc1 -fmodules -fimplicit-module-maps -fmodules-cache-path=%t/cache -ivfsoverlay %t/vdir/bar-headers.yaml -F %t/vdir -fsyntax-only %s
+
+@import Bar;