Add dependencies from imported modules with -MD

Add module dependencies to the dependency files created by -MD/-MMD/etc.
by attaching an ASTReaderListener that will call into the dependency
file generator when a module input file is seen in the serialized AST.

llvm-svn: 203208

clang/lib/Frontend/CompilerInstance.cpp

@@ -269,7 +269,8 @@ void CompilerInstance::createPreprocessor() {
   // Handle generating dependencies, if requested.
   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
   if (!DepOpts.OutputFile.empty())
-    AttachDependencyFileGen(*PP, DepOpts);
+    TheDependencyFileGenerator.reset(
+        DependencyFileGenerator::CreateAndAttachToPreprocessor(*PP, DepOpts));
   if (!DepOpts.DOTOutputFile.empty())
     AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
                              getHeaderSearchOpts().Sysroot);
@@ -1160,6 +1161,9 @@ CompilerInstance::loadModule(SourceLocation ImportLoc,
         ModuleManager->StartTranslationUnit(&getASTConsumer());
     }
 
+    if (TheDependencyFileGenerator)
+      TheDependencyFileGenerator->AttachToASTReader(*ModuleManager);
+
     // Try to load the module file.
     unsigned ARRFlags = ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing;
     switch (ModuleManager->ReadAST(ModuleFileName, serialization::MK_Module,