GeneratePCH.cpp revision 89d9980bbc2e4a4ac86673e6ec16fb9f5babb63b 
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
27using namespace clang;
28
29PCHGenerator::PCHGenerator(const Preprocessor &PP,
30                           bool Chaining,
31                           const char *isysroot,
32                           llvm::raw_ostream *OS)
33  : PP(PP), isysroot(isysroot), Out(OS), SemaPtr(0),
34    StatCalls(0), Stream(Buffer), Writer(Stream), Chaining(Chaining) {
35  // Install a stat() listener to keep track of all of the stat()
36  // calls.
37  StatCalls = new MemorizeStatCalls();
38  // If we have a chain, we want new stat calls only, so install the memorizer
39  // *after* the already installed ASTReader's stat cache.
40  PP.getFileManager().addStatCache(StatCalls,
41    /*AtBeginning=*/!Chaining);
42}
43
44void PCHGenerator::HandleTranslationUnit(ASTContext &Ctx) {
45  if (PP.getDiagnostics().hasErrorOccurred())
46    return;
47
48  // Set up the serialization listener.
49  Writer.SetSerializationListener(GetASTSerializationListener());
50
51  // Emit the PCH file
52  assert(SemaPtr && "No Sema?");
53  Writer.WriteAST(*SemaPtr, StatCalls, isysroot);
54
55  // Write the generated bitstream to "Out".
56  Out->write((char *)&Buffer.front(), Buffer.size());
57
58  // Make sure it hits disk now.
59  Out->flush();
60
61  // Free up some memory, in case the process is kept alive.
62  Buffer.clear();
63}
64
65ASTMutationListener *PCHGenerator::GetASTMutationListener() {
66  if (Chaining)
67    return &Writer;
68  return 0;
69}
70
71ASTSerializationListener *PCHGenerator::GetASTSerializationListener() {
72  return 0;
73}
74
75ASTDeserializationListener *PCHGenerator::GetASTDeserializationListener() {
76  return &Writer;
77}
78