[modules] Add -cc1 flag -fmodules-embed-all-files.

This flag causes all files that were read by the compilation to be embedded
into a produced module file. This is useful for distributed build systems that
use an include scanning system to determine which files are "needed" by a
compilation, and only provide those files to remote compilation workers. Since
using a module can require any file that is part of that module (or anything it
transitively includes), files that are not found by an include scanner can be
required in a regular build using explicit modules. With this flag, only files
that are actually referenced by transitively-#included files are required to be
present on the build machine.

llvm-svn: 253950

1 files changed, 2 insertions, 1 deletions

diff --git a/clang/lib/Basic/SourceManager.cpp b/clang/lib/Basic/SourceManager.cpp
index 734f204..7abcba1 100644
--- a/clang/lib/Basic/SourceManager.cpp
+++ b/clang/lib/Basic/SourceManager.cpp
@@ -361,7 +361,7 @@ LineTableInfo &SourceManager::getLineTable() {
 SourceManager::SourceManager(DiagnosticsEngine &Diag, FileManager &FileMgr,
                              bool UserFilesAreVolatile)
   : Diag(Diag), FileMgr(FileMgr), OverridenFilesKeepOriginalName(true),
-    UserFilesAreVolatile(UserFilesAreVolatile),
+    UserFilesAreVolatile(UserFilesAreVolatile), FilesAreTransient(false),
     ExternalSLocEntries(nullptr), LineTable(nullptr), NumLinearScans(0),
     NumBinaryProbes(0) {
   clearIDTables();
@@ -439,6 +439,7 @@ SourceManager::getOrCreateContentCache(const FileEntry *FileEnt,
   }
 
   Entry->IsSystemFile = isSystemFile;
+  Entry->BufferOverridden = FilesAreTransient;
 
   return Entry;
 }