GeneratePCH.cpp revision 4947e25dd9f7ac1f2176d63262563ba3e96538fe 
1//===--- GeneratePCH.cpp - AST Consumer for PCH Generation ------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file defines the CreatePCHGenerate function, which creates an
11//  ASTConsumer that generates a PCH file.
12//
13//===----------------------------------------------------------------------===//
14
15#include "clang/Frontend/ASTConsumers.h"
16#include "clang/Serialization/ASTWriter.h"
17#include "clang/Sema/SemaConsumer.h"
18#include "clang/AST/ASTContext.h"
19#include "clang/AST/ASTConsumer.h"
20#include "clang/Lex/Preprocessor.h"
21#include "clang/Basic/FileManager.h"
22#include "clang/Basic/FileSystemStatCache.h"
23#include "llvm/Bitcode/BitstreamWriter.h"
24#include "llvm/Support/raw_ostream.h"
25#include <string>
26#include <string.h>
27#include <stdlib.h>
28
29using namespace clang;
30
31PCHGenerator::PCHGenerator(const Preprocessor &PP,
32                           const std::string &OutputFile,
33                           bool Chaining,
34                           const char *isysroot,
35                           llvm::raw_ostream *OS)
36  : PP(PP), OutputFile(OutputFile), isysroot(0), Out(OS), SemaPtr(0),
37    StatCalls(0), Stream(Buffer), Writer(Stream), Chaining(Chaining) {
38  // Install a stat() listener to keep track of all of the stat()
39  // calls.
40  StatCalls = new MemorizeStatCalls();
41  // If we have a chain, we want new stat calls only, so install the memorizer
42  // *after* the already installed ASTReader's stat cache.
43  PP.getFileManager().addStatCache(StatCalls,
44    /*AtBeginning=*/!Chaining);
45
46  if (isysroot)
47    this->isysroot = strdup(isysroot);
48}
49
50PCHGenerator::~PCHGenerator() {
51  free((void*)isysroot);
52}
53
54void PCHGenerator::HandleTranslationUnit(ASTContext &Ctx) {
55  if (PP.getDiagnostics().hasErrorOccurred())
56    return;
57
58  // Set up the serialization listener.
59  Writer.SetSerializationListener(GetASTSerializationListener());
60
61  // Emit the PCH file
62  assert(SemaPtr && "No Sema?");
63  Writer.WriteAST(*SemaPtr, StatCalls, OutputFile, isysroot);
64
65  // Write the generated bitstream to "Out".
66  Out->write((char *)&Buffer.front(), Buffer.size());
67
68  // Make sure it hits disk now.
69  Out->flush();
70
71  // Free up some memory, in case the process is kept alive.
72  Buffer.clear();
73}
74
75ASTMutationListener *PCHGenerator::GetASTMutationListener() {
76  if (Chaining)
77    return &Writer;
78  return 0;
79}
80
81ASTSerializationListener *PCHGenerator::GetASTSerializationListener() {
82  return 0;
83}
84
85ASTDeserializationListener *PCHGenerator::GetASTDeserializationListener() {
86  return &Writer;
87}
88