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 
27 using namespace clang;
28 
29 PCHGenerator::PCHGenerator(const Preprocessor &PP,
30                            StringRef OutputFile,
31                            bool IsModule,
32                            StringRef isysroot,
33                            raw_ostream *OS)
34   : PP(PP), OutputFile(OutputFile), IsModule(IsModule),
35     isysroot(isysroot.str()), Out(OS),
36     SemaPtr(0), StatCalls(0), Stream(Buffer), Writer(Stream) {
37   // Install a stat() listener to keep track of all of the stat()
38   // calls.
39   StatCalls = new MemorizeStatCalls();
40   PP.getFileManager().addStatCache(StatCalls, /*AtBeginning=*/false);
41 }
42 
43 PCHGenerator::~PCHGenerator() {
44 }
45 
46 void PCHGenerator::HandleTranslationUnit(ASTContext &Ctx) {
47   if (PP.getDiagnostics().hasErrorOccurred())
48     return;
49 
50   // Emit the PCH file
51   assert(SemaPtr && "No Sema?");
52   Writer.WriteAST(*SemaPtr, StatCalls, OutputFile, IsModule, isysroot);
53 
54   // Write the generated bitstream to "Out".
55   Out->write((char *)&Buffer.front(), Buffer.size());
56 
57   // Make sure it hits disk now.
58   Out->flush();
59 
60   // Free up some memory, in case the process is kept alive.
61   Buffer.clear();
62 }
63 
64 ASTMutationListener *PCHGenerator::GetASTMutationListener() {
65   return &Writer;
66 }
67 
68 ASTDeserializationListener *PCHGenerator::GetASTDeserializationListener() {
69   return &Writer;
70 }
71