clang/lib/Serialization/PCHContainerOperations.cpp

   1 //=== Serialization/PCHContainerOperations.cpp - PCH Containers -*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 //  This file defines PCHContainerOperations and RawPCHContainerOperation.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "clang/Serialization/PCHContainerOperations.h"
  14 #include "clang/AST/ASTConsumer.h"
  15 #include "clang/Lex/ModuleLoader.h"
  16 #include "llvm/Bitstream/BitstreamReader.h"
  17 #include "llvm/Support/raw_ostream.h"
  18 #include <utility>
  19
  20 using namespace clang;
  21
  22 PCHContainerWriter::~PCHContainerWriter() {}
  23 PCHContainerReader::~PCHContainerReader() {}
  24
  25 namespace {
  26
  27 /// A PCHContainerGenerator that writes out the PCH to a flat file.
  28 class RawPCHContainerGenerator : public ASTConsumer {
  29   std::shared_ptr<PCHBuffer> Buffer;
  30   std::unique_ptr<raw_pwrite_stream> OS;
  31
  32 public:
  33   RawPCHContainerGenerator(std::unique_ptr<llvm::raw_pwrite_stream> OS,
  34                            std::shared_ptr<PCHBuffer> Buffer)
  35       : Buffer(std::move(Buffer)), OS(std::move(OS)) {}
  36
  37   ~RawPCHContainerGenerator() override = default;
  38
  39   void HandleTranslationUnit(ASTContext &Ctx) override {
  40     if (Buffer->IsComplete) {
  41       // Make sure it hits disk now.
  42       *OS << Buffer->Data;
  43       OS->flush();
  44     }
  45     // Free the space of the temporary buffer.
  46     llvm::SmallVector<char, 0> Empty;
  47     Buffer->Data = std::move(Empty);
  48   }
  49 };
  50
  51 } // anonymous namespace
  52
  53 std::unique_ptr<ASTConsumer> RawPCHContainerWriter::CreatePCHContainerGenerator(
  54     CompilerInstance &CI, const std::string &MainFileName,
  55     const std::string &OutputFileName, std::unique_ptr<llvm::raw_pwrite_stream> OS,
  56     std::shared_ptr<PCHBuffer> Buffer) const {
  57   return std::make_unique<RawPCHContainerGenerator>(std::move(OS), Buffer);
  58 }
  59
  60 StringRef
  61 RawPCHContainerReader::ExtractPCH(llvm::MemoryBufferRef Buffer) const {
  62   return Buffer.getBuffer();
  63 }
  64
  65 PCHContainerOperations::PCHContainerOperations() {
  66   registerWriter(std::make_unique<RawPCHContainerWriter>());
  67   registerReader(std::make_unique<RawPCHContainerReader>());
  68 }