Revert "Wrap clang module files in a Mach-O, ELF, or COFF container."

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@230454 91177308-0d34-0410-b5e6-96231b3b80d8

Author: adrian-prantl

docs/PCHInternals.rst

@@ -65,9 +65,6 @@ be included at the beginning of the translation unit.  The extensions to the
 AST file format required for modules are discussed in the section on
 :ref:`modules <pchinternals-modules>`.
 
-Clang's AST files are Mach-O, ELF, or COFF containers that contain a
-``__clangast`` section which holds the AST bitstream.
-
 Clang's AST files are designed with a compact on-disk representation, which
 minimizes both creation time and the time required to initially load the AST
 file.  The AST file itself contains a serialized representation of Clang's

include/clang/CodeGen/CodeGenModuleContainer.h

@@ -69,14 +69,6 @@ class DeclContextPrintAction : public ASTFrontendAction {
                                                  StringRef InFile) override;
 };
 
-/// \brief Emits the output of a GeneratePCHAction or GenerateModuleAction into
-/// a Mach-O/ELF/COFF container.
-class GeneratePCMContainerAction : public FrontendAction {
-protected:
-  std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,
-                                                 StringRef InFile) override;
-};
-
 class GeneratePCHAction : public ASTFrontendAction {
 protected:
   std::unique_ptr<ASTConsumer> CreateASTConsumer(CompilerInstance &CI,

include/clang/Frontend/FrontendActions.h

@@ -1127,10 +1127,6 @@ class ASTReader
 public:
   void ResolveImportedPath(ModuleFile &M, std::string &Filename);
   static void ResolveImportedPath(std::string &Filename, StringRef Prefix);
-  /// \brief Initialize a BitstreamReader with the `__clangast` section from an
-  /// object file container found in Buffer.
-  static void InitStreamFileWithModule(llvm::MemoryBufferRef Buffer,
-                                       llvm::BitstreamReader &StreamFile);
 
 private:
   struct ImportedModule {

include/clang/Serialization/ASTReader.h

@@ -823,13 +823,10 @@ class PCHGenerator : public SemaConsumer {
   std::string OutputFile;
   clang::Module *Module;
   std::string isysroot;
+  raw_ostream *Out;
   Sema *SemaPtr;
-  // This buffer is always large, but BitstreamWriter really wants a
-  // SmallVectorImpl<char>.
-  SmallVector<char, 0> Buffer;
+  SmallVector<char, 128> Buffer;
   llvm::BitstreamWriter Stream;
-  std::function<void(SmallVectorImpl<char>*)>
-    SerializationFinishedCallback;
   ASTWriter Writer;
   bool AllowASTWithErrors;
   bool HasEmittedPCH;
@@ -839,21 +836,16 @@ class PCHGenerator : public SemaConsumer {
   const ASTWriter &getWriter() const { return Writer; }
 
 public:
-  PCHGenerator(const Preprocessor &PP,
-               StringRef OutputFile,
+  PCHGenerator(const Preprocessor &PP, StringRef OutputFile,
                clang::Module *Module,
-               StringRef isysroot,
+               StringRef isysroot, raw_ostream *Out,
                bool AllowASTWithErrors = false);
   ~PCHGenerator();
   void InitializeSema(Sema &S) override { SemaPtr = &S; }
   void HandleTranslationUnit(ASTContext &Ctx) override;
   ASTMutationListener *GetASTMutationListener() override;
   ASTDeserializationListener *GetASTDeserializationListener() override;
-  /// \brief Register a callback to be invoked when the serialization is done.
-  void RegisterSerializationFinishedCallback(
-    const std::function<void(SmallVectorImpl<char>*)> Fn) {
-    SerializationFinishedCallback = Fn;
-  }
+
   bool hasEmittedPCH() const { return HasEmittedPCH; }
 };
 

include/clang/Serialization/ASTWriter.h

@@ -1,5 +1,4 @@
 set(LLVM_LINK_COMPONENTS
-  ${LLVM_TARGETS_TO_BUILD}
   Analysis
   BitReader
   BitWriter
@@ -64,7 +63,6 @@ add_clang_library(clangCodeGen
   CodeGenAction.cpp
   CodeGenFunction.cpp
   CodeGenModule.cpp
-  CodeGenModuleContainer.cpp
   CodeGenPGO.cpp
   CodeGenTBAA.cpp
   CodeGenTypes.cpp

lib/CodeGen/CMakeLists.txt

@@ -914,20 +914,13 @@ class PrecompilePreambleConsumer : public PCHGenerator {
   unsigned &Hash;
   std::vector<Decl *> TopLevelDecls;
   PrecompilePreambleAction *Action;
-  raw_ostream *Out;
-  SmallVectorImpl<char> *SerializedASTBuffer;
 
 public:
   PrecompilePreambleConsumer(ASTUnit &Unit, PrecompilePreambleAction *Action,
                              const Preprocessor &PP, StringRef isysroot,
                              raw_ostream *Out)
-    : PCHGenerator(PP, "", nullptr, isysroot, /*AllowASTWithErrors=*/true),
-      Unit(Unit), Hash(Unit.getCurrentTopLevelHashValue()), Action(Action),
-      Out(Out) {
-    RegisterSerializationFinishedCallback(
-      [&](SmallVectorImpl<char> *Buf){
-        SerializedASTBuffer = Buf;
-      });
+    : PCHGenerator(PP, "", nullptr, isysroot, Out, /*AllowASTWithErrors=*/true),
+      Unit(Unit), Hash(Unit.getCurrentTopLevelHashValue()), Action(Action) {
     Hash = 0;
   }
 
@@ -948,13 +941,6 @@ class PrecompilePreambleConsumer : public PCHGenerator {
   void HandleTranslationUnit(ASTContext &Ctx) override {
     PCHGenerator::HandleTranslationUnit(Ctx);
     if (hasEmittedPCH()) {
-      // Write the generated bitstream to "Out".
-      Out->write((char *)&SerializedASTBuffer->front(),
-                 SerializedASTBuffer->size());
-      // Make sure it hits disk now.
-      Out->flush();
-      SerializedASTBuffer->clear();
-
       // Translate the top-level declarations we captured during
       // parsing into declaration IDs in the precompiled
       // preamble. This will allow us to deserialize those top-level

lib/CodeGen/CodeGenModuleContainer.cpp

@@ -45,7 +45,6 @@ add_clang_library(clangFrontend
   LINK_LIBS
   clangAST
   clangBasic
-  clangCodeGen
   clangDriver
   clangEdit
   clangLex

lib/Frontend/ASTUnit.cpp

@@ -156,13 +156,11 @@ IntrusiveRefCntPtr<ExternalSemaSource> clang::createChainedIncludesSource(
                                                  &Clang->getPreprocessor());
     Clang->createASTContext();
 
-    auto consumer = llvm::make_unique<PCHGenerator>(Clang->getPreprocessor(),
-                                       "-", nullptr, /*isysroot=*/"");
-    SmallVectorImpl<char> *serialAST;
-    consumer->RegisterSerializationFinishedCallback(
-      [&](SmallVectorImpl<char> *Buf){
-        serialAST = Buf;
-      });
+    SmallVector<char, 256> serialAST;
+    llvm::raw_svector_ostream OS(serialAST);
+    auto consumer =
+        llvm::make_unique<PCHGenerator>(Clang->getPreprocessor(), "-", nullptr,
+                                        /*isysroot=*/"", &OS);
     Clang->getASTContext().setASTMutationListener(
                                             consumer->GetASTMutationListener());
     Clang->setASTConsumer(std::move(consumer));
@@ -199,9 +197,7 @@ IntrusiveRefCntPtr<ExternalSemaSource> clang::createChainedIncludesSource(
 
     ParseAST(Clang->getSema());
     Clang->getDiagnosticClient().EndSourceFile();
-    SerialBufs.push_back(llvm::MemoryBuffer::
-        getMemBufferCopy(StringRef(serialAST->data(), serialAST->size())));
-    serialAST->clear();
+    SerialBufs.push_back(llvm::MemoryBuffer::getMemBufferCopy(OS.str()));
     source->CIs.push_back(Clang.release());
   }