1//===--- GeneratePCH.cpp - Sema 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 PCHGenerator, which as a SemaConsumer that generates
11//  a PCH file.
12//
13//===----------------------------------------------------------------------===//
14
15#include "clang/Serialization/ASTWriter.h"
16#include "clang/AST/ASTConsumer.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/Basic/FileManager.h"
19#include "clang/Lex/Preprocessor.h"
20#include "clang/Sema/SemaConsumer.h"
21#include "llvm/Bitcode/BitstreamWriter.h"
22#include "llvm/Support/raw_ostream.h"
23#include <string>
24
25using namespace clang;
26
27PCHGenerator::PCHGenerator(const Preprocessor &PP,
28                           StringRef OutputFile,
29                           clang::Module *Module,
30                           StringRef isysroot,
31                           raw_ostream *OS, bool AllowASTWithErrors)
32  : PP(PP), OutputFile(OutputFile), Module(Module),
33    isysroot(isysroot.str()), Out(OS),
34    SemaPtr(nullptr), Stream(Buffer), Writer(Stream),
35    AllowASTWithErrors(AllowASTWithErrors),
36    HasEmittedPCH(false) {
37}
38
39PCHGenerator::~PCHGenerator() {
40}
41
42void PCHGenerator::HandleTranslationUnit(ASTContext &Ctx) {
43  // Don't create a PCH if there were fatal failures during module loading.
44  if (PP.getModuleLoader().HadFatalFailure)
45    return;
46
47  bool hasErrors = PP.getDiagnostics().hasErrorOccurred();
48  if (hasErrors && !AllowASTWithErrors)
49    return;
50
51  // Emit the PCH file
52  assert(SemaPtr && "No Sema?");
53  Writer.WriteAST(*SemaPtr, OutputFile, Module, isysroot, hasErrors);
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  HasEmittedPCH = true;
65}
66
67ASTMutationListener *PCHGenerator::GetASTMutationListener() {
68  return &Writer;
69}
70
71ASTDeserializationListener *PCHGenerator::GetASTDeserializationListener() {
72  return &Writer;
73}
74