From: Douglas Gregor <dgregor@apple.com>
Date: Mon, 22 Jul 2013 20:48:33 +0000 (+0000)
Subject: Make modules depend on the compiler's own module.map, as a proxy for the compiler... 
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b22d19493d479bf3ed6e5e60bfcf7047823da7fc;p=clang

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>.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186870 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/clang/Serialization/ASTWriter.h b/include/clang/Serialization/ASTWriter.h
index 25335967bc..e94b685e97 100644
--- a/include/clang/Serialization/ASTWriter.h
+++ b/include/clang/Serialization/ASTWriter.h
@@ -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);
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 5f9da8a4a3..08d7f96fad 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -1233,7 +1233,8 @@ void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
 
   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;
@@ -1302,6 +1304,19 @@ void ASTWriter::WriteInputFiles(SourceManager &SourceMgr,
     }
   }
 
+  // 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.
   std::vector<uint32_t> InputFileOffsets;