1 //===--- GeneratePCH.cpp - Sema Consumer for PCH Generation -----*- 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 the PCHGenerator, which as a SemaConsumer that generates
10 // a PCH file.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "clang/AST/ASTContext.h"
15 #include "clang/Lex/HeaderSearch.h"
16 #include "clang/Lex/Preprocessor.h"
17 #include "clang/Sema/SemaConsumer.h"
18 #include "clang/Serialization/ASTWriter.h"
19 #include "llvm/Bitstream/BitstreamWriter.h"
20
21 using namespace clang;
22
PCHGenerator(const Preprocessor & PP,InMemoryModuleCache & ModuleCache,StringRef OutputFile,StringRef isysroot,std::shared_ptr<PCHBuffer> Buffer,ArrayRef<std::shared_ptr<ModuleFileExtension>> Extensions,bool AllowASTWithErrors,bool IncludeTimestamps,bool BuildingImplicitModule,bool ShouldCacheASTInMemory)23 PCHGenerator::PCHGenerator(
24 const Preprocessor &PP, InMemoryModuleCache &ModuleCache,
25 StringRef OutputFile, StringRef isysroot, std::shared_ptr<PCHBuffer> Buffer,
26 ArrayRef<std::shared_ptr<ModuleFileExtension>> Extensions,
27 bool AllowASTWithErrors, bool IncludeTimestamps,
28 bool BuildingImplicitModule, bool ShouldCacheASTInMemory)
29 : PP(PP), OutputFile(OutputFile), isysroot(isysroot.str()),
30 SemaPtr(nullptr), Buffer(std::move(Buffer)), Stream(this->Buffer->Data),
31 Writer(Stream, this->Buffer->Data, ModuleCache, Extensions,
32 IncludeTimestamps, BuildingImplicitModule),
33 AllowASTWithErrors(AllowASTWithErrors),
34 ShouldCacheASTInMemory(ShouldCacheASTInMemory) {
35 this->Buffer->IsComplete = false;
36 }
37
~PCHGenerator()38 PCHGenerator::~PCHGenerator() {
39 }
40
HandleTranslationUnit(ASTContext & Ctx)41 void PCHGenerator::HandleTranslationUnit(ASTContext &Ctx) {
42 // Don't create a PCH if there were fatal failures during module loading.
43 if (PP.getModuleLoader().HadFatalFailure)
44 return;
45
46 bool hasErrors = PP.getDiagnostics().hasErrorOccurred();
47 if (hasErrors && !AllowASTWithErrors)
48 return;
49
50 Module *Module = nullptr;
51 if (PP.getLangOpts().isCompilingModule()) {
52 Module = PP.getHeaderSearchInfo().lookupModule(
53 PP.getLangOpts().CurrentModule, SourceLocation(),
54 /*AllowSearch*/ false);
55 if (!Module) {
56 assert(hasErrors && "emitting module but current module doesn't exist");
57 return;
58 }
59 }
60
61 // Errors that do not prevent the PCH from being written should not cause the
62 // overall compilation to fail either.
63 if (AllowASTWithErrors)
64 PP.getDiagnostics().getClient()->clear();
65
66 // Emit the PCH file to the Buffer.
67 assert(SemaPtr && "No Sema?");
68 Buffer->Signature = Writer.WriteAST(*SemaPtr, OutputFile, Module, isysroot,
69 ShouldCacheASTInMemory);
70
71 Buffer->IsComplete = true;
72 }
73
GetASTMutationListener()74 ASTMutationListener *PCHGenerator::GetASTMutationListener() {
75 return &Writer;
76 }
77
GetASTDeserializationListener()78 ASTDeserializationListener *PCHGenerator::GetASTDeserializationListener() {
79 return &Writer;
80 }
81