r186870 - Make modules depend on the compiler's own module.map, as a proxy for the compiler itself.

[Douglas Gregor]

Author: dgregor
Date: Mon Jul 22 15:48:33 2013
New Revision: 186870

URL: http://llvm.org/viewvc/llvm-project?rev=186870&view=rev
Log:
Make modules depend on the compiler's own module.map, as a proxy for the compiler itself.

The headers in the compiler's own resource include directory are
system headers, which means we don't stat() them eagerly when loading
a module. Use module.map as a proxy for these headers and the compiler
itself. Fixes <rdar://problem/13856838>.

Modified:
    cfe/trunk/include/clang/Serialization/ASTWriter.h
    cfe/trunk/lib/Serialization/ASTWriter.cpp

Modified: cfe/trunk/include/clang/Serialization/ASTWriter.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Serialization/ASTWriter.h?rev=186870&r1=186869&r2=186870&view=diff
==============================================================================
--- cfe/trunk/include/clang/Serialization/ASTWriter.h (original)
+++ cfe/trunk/include/clang/Serialization/ASTWriter.h Mon Jul 22 15:48:33 2013
@@ -424,7 +424,8 @@ private:
                          StringRef isysroot, const std::string &OutputFile);
   void WriteInputFiles(SourceManager &SourceMgr,
                        HeaderSearchOptions &HSOpts,
-                       StringRef isysroot);
+                       StringRef isysroot,
+                       bool Modules);
   void WriteSourceManagerBlock(SourceManager &SourceMgr,
                                const Preprocessor &PP,
                                StringRef isysroot);

Modified: cfe/trunk/lib/Serialization/ASTWriter.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Serialization/ASTWriter.cpp?rev=186870&r1=186869&r2=186870&view=diff
==============================================================================
--- cfe/trunk/lib/Serialization/ASTWriter.cpp (original)
+++ cfe/trunk/lib/Serialization/ASTWriter.cpp Mon Jul 22 15:48:33 2013
@@ -1233,7 +1233,8 @@ void ASTWriter::WriteControlBlock(Prepro
 
   WriteInputFiles(Context.SourceMgr,
                   PP.getHeaderSearchInfo().getHeaderSearchOpts(),
-                  isysroot);
+                  isysroot,
+                  PP.getLangOpts().Modules);
   Stream.ExitBlock();
 }
 
@@ -1248,7 +1249,8 @@ namespace  {
 
 void ASTWriter::WriteInputFiles(SourceManager &SourceMgr,
                                 HeaderSearchOptions &HSOpts,
-                                StringRef isysroot) {
+                                StringRef isysroot,
+                                bool Modules) {
   using namespace llvm;
   Stream.EnterSubblock(INPUT_FILES_BLOCK_ID, 4);
   RecordData Record;
@@ -1301,6 +1303,19 @@ void ASTWriter::WriteInputFiles(SourceMa
       SortedFiles.push_front(Entry);
     }
   }
+
+  // Add the compiler's own module.map in the set of (non-system) input files.
+  // This is a simple heuristic for detecting whether the compiler's headers
+  // have changed, because we don't want to stat() all of them.
+  if (Modules && !Chain) {
+    SmallString<128> P = StringRef(HSOpts.ResourceDir);
+    llvm::sys::path::append(P, "include");
+    llvm::sys::path::append(P, "module.map");
+    if (const FileEntry *ModuleMapFile = FileMgr.getFile(P)) {
+      InputFileEntry Entry = { ModuleMapFile, false, false };
+      SortedFiles.push_front(Entry);
+    }
+  }
 
   unsigned UserFilesNum = 0;
   // Write out all of the input files.