[clang] Add PPCallbacks list to preprocessor when building a preacompiled preamble.

Summary:
Revision D38639 needs this commit in order to properly make open
definition calls on include statements work.

Patch by William Enright.

Reviewers: malaperle, krasimir, bkramer, ilya-biryukov

Reviewed By: malaperle, ilya-biryukov

Subscribers: cfe-commits, arphaman, ilya-biryukov

Differential Revision: https://reviews.llvm.org/D39375

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@320804 91177308-0d34-0410-b5e6-96231b3b80d8

Author: ilya-biryukov

include/clang/Frontend/PrecompiledPreamble.h

@@ -255,11 +255,9 @@ class PreambleCallbacks {
   /// NOTE: To allow more flexibility a custom ASTConsumer could probably be
   /// used instead, but having only this method allows a simpler API.
   virtual void HandleTopLevelDecl(DeclGroupRef DG);
-  /// Called for each macro defined in the Preamble.
-  /// NOTE: To allow more flexibility a custom PPCallbacks could probably be
-  /// used instead, but having only this method allows a simpler API.
-  virtual void HandleMacroDefined(const Token &MacroNameTok,
-                                  const MacroDirective *MD);
+  /// Creates wrapper class for PPCallbacks so we can also process information
+  /// about includes that are inside of a preamble
+  virtual std::unique_ptr<PPCallbacks> createPPCallbacks();
 };
 
 enum class BuildPreambleError {

lib/Frontend/ASTUnit.cpp

@@ -970,9 +970,8 @@ class ASTUnitPreambleCallbacks : public PreambleCallbacks {
     }
   }
 
-  void HandleMacroDefined(const Token &MacroNameTok,
-                          const MacroDirective *MD) override {
-    AddDefinedMacroToHash(MacroNameTok, Hash);
+  std::unique_ptr<PPCallbacks> createPPCallbacks() override {
+    return llvm::make_unique<MacroDefinitionTrackerPPCallbacks>(Hash);
   }
 
 private:

lib/Frontend/PrecompiledPreamble.cpp

@@ -115,19 +115,6 @@ void TemporaryFiles::removeFile(StringRef File) {
   llvm::sys::fs::remove(File);
 }
 
-class PreambleMacroCallbacks : public PPCallbacks {
-public:
-  PreambleMacroCallbacks(PreambleCallbacks &Callbacks) : Callbacks(Callbacks) {}
-
-  void MacroDefined(const Token &MacroNameTok,
-                    const MacroDirective *MD) override {
-    Callbacks.HandleMacroDefined(MacroNameTok, MD);
-  }
-
-private:
-  PreambleCallbacks &Callbacks;
-};
-
 class PrecompilePreambleAction : public ASTFrontendAction {
 public:
   PrecompilePreambleAction(std::string *InMemStorage,
@@ -213,8 +200,6 @@ PrecompilePreambleAction::CreateASTConsumer(CompilerInstance &CI,
   if (!CI.getFrontendOpts().RelocatablePCH)
     Sysroot.clear();
 
-  CI.getPreprocessor().addPPCallbacks(
-      llvm::make_unique<PreambleMacroCallbacks>(Callbacks));
   return llvm::make_unique<PrecompilePreambleConsumer>(
       *this, CI.getPreprocessor(), Sysroot, std::move(OS));
 }
@@ -351,6 +336,11 @@ llvm::ErrorOr<PrecompiledPreamble> PrecompiledPreamble::Build(
   if (!Act->BeginSourceFile(*Clang.get(), Clang->getFrontendOpts().Inputs[0]))
     return BuildPreambleError::BeginSourceFileFailed;
 
+  std::unique_ptr<PPCallbacks> DelegatedPPCallbacks =
+      Callbacks.createPPCallbacks();
+  if (DelegatedPPCallbacks)
+    Clang->getPreprocessor().addPPCallbacks(std::move(DelegatedPPCallbacks));
+
   Act->Execute();
 
   // Run the callbacks.
@@ -707,8 +697,9 @@ void PrecompiledPreamble::setupPreambleStorage(
 void PreambleCallbacks::AfterExecute(CompilerInstance &CI) {}
 void PreambleCallbacks::AfterPCHEmitted(ASTWriter &Writer) {}
 void PreambleCallbacks::HandleTopLevelDecl(DeclGroupRef DG) {}
-void PreambleCallbacks::HandleMacroDefined(const Token &MacroNameTok,
-                                           const MacroDirective *MD) {}
+std::unique_ptr<PPCallbacks> PreambleCallbacks::createPPCallbacks() {
+  return nullptr;
+}
 
 std::error_code clang::make_error_code(BuildPreambleError Error) {
   return std::error_code(static_cast<int>(Error), BuildPreambleErrorCategory());