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 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 38 PCHGenerator::~PCHGenerator() { 39 } 40 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 74 ASTMutationListener *PCHGenerator::GetASTMutationListener() { 75 return &Writer; 76 } 77 78 ASTDeserializationListener *PCHGenerator::GetASTDeserializationListener() { 79 return &Writer; 80 } 81