145 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8//9// This file defines the PCHGenerator, which as a SemaConsumer that generates10// a PCH file.11//12//===----------------------------------------------------------------------===//13 14#include "clang/AST/ASTContext.h"15#include "clang/Basic/DiagnosticFrontend.h"16#include "clang/Lex/HeaderSearch.h"17#include "clang/Lex/HeaderSearchOptions.h"18#include "clang/Lex/Preprocessor.h"19#include "clang/Sema/SemaConsumer.h"20#include "clang/Serialization/ASTWriter.h"21#include "llvm/Bitstream/BitstreamWriter.h"22 23using namespace clang;24 25PCHGenerator::PCHGenerator(26 Preprocessor &PP, ModuleCache &ModCache, StringRef OutputFile,27 StringRef isysroot, std::shared_ptr<PCHBuffer> Buffer,28 const CodeGenOptions &CodeGenOpts,29 ArrayRef<std::shared_ptr<ModuleFileExtension>> Extensions,30 bool AllowASTWithErrors, bool IncludeTimestamps,31 bool BuildingImplicitModule, bool ShouldCacheASTInMemory,32 bool GeneratingReducedBMI)33 : PP(PP), Subject(&PP), OutputFile(OutputFile), isysroot(isysroot.str()),34 Buffer(std::move(Buffer)), Stream(this->Buffer->Data),35 Writer(Stream, this->Buffer->Data, ModCache, CodeGenOpts, Extensions,36 IncludeTimestamps, BuildingImplicitModule, GeneratingReducedBMI),37 AllowASTWithErrors(AllowASTWithErrors),38 ShouldCacheASTInMemory(ShouldCacheASTInMemory) {39 this->Buffer->IsComplete = false;40}41 42PCHGenerator::~PCHGenerator() {43}44 45Module *PCHGenerator::getEmittingModule(ASTContext &) {46 Module *M = nullptr;47 48 if (PP.getLangOpts().isCompilingModule()) {49 M = PP.getHeaderSearchInfo().lookupModule(PP.getLangOpts().CurrentModule,50 SourceLocation(),51 /*AllowSearch*/ false);52 if (!M)53 assert(PP.getDiagnostics().hasErrorOccurred() &&54 "emitting module but current module doesn't exist");55 }56 57 return M;58}59 60DiagnosticsEngine &PCHGenerator::getDiagnostics() const {61 return PP.getDiagnostics();62}63 64void PCHGenerator::InitializeSema(Sema &S) {65 if (!PP.getHeaderSearchInfo()66 .getHeaderSearchOpts()67 .ModulesSerializeOnlyPreprocessor)68 Subject = &S;69}70 71void PCHGenerator::HandleTranslationUnit(ASTContext &Ctx) {72 // Don't create a PCH if there were fatal failures during module loading.73 if (PP.getModuleLoader().HadFatalFailure)74 return;75 76 bool hasErrors = PP.getDiagnostics().hasErrorOccurred();77 if (hasErrors && !AllowASTWithErrors)78 return;79 80 Module *Module = getEmittingModule(Ctx);81 82 // Errors that do not prevent the PCH from being written should not cause the83 // overall compilation to fail either.84 if (AllowASTWithErrors)85 PP.getDiagnostics().getClient()->clear();86 87 Buffer->Signature = Writer.WriteAST(Subject, OutputFile, Module, isysroot,88 ShouldCacheASTInMemory);89 90 Buffer->IsComplete = true;91}92 93ASTMutationListener *PCHGenerator::GetASTMutationListener() {94 return &Writer;95}96 97ASTDeserializationListener *PCHGenerator::GetASTDeserializationListener() {98 return &Writer;99}100 101void PCHGenerator::anchor() {}102 103CXX20ModulesGenerator::CXX20ModulesGenerator(Preprocessor &PP,104 ModuleCache &ModCache,105 StringRef OutputFile,106 const CodeGenOptions &CodeGenOpts,107 bool GeneratingReducedBMI,108 bool AllowASTWithErrors)109 : PCHGenerator(110 PP, ModCache, OutputFile, llvm::StringRef(),111 std::make_shared<PCHBuffer>(), CodeGenOpts,112 /*Extensions=*/ArrayRef<std::shared_ptr<ModuleFileExtension>>(),113 AllowASTWithErrors, /*IncludeTimestamps=*/false,114 /*BuildingImplicitModule=*/false, /*ShouldCacheASTInMemory=*/false,115 GeneratingReducedBMI) {}116 117Module *CXX20ModulesGenerator::getEmittingModule(ASTContext &Ctx) {118 Module *M = Ctx.getCurrentNamedModule();119 assert(M && M->isNamedModuleUnit() &&120 "CXX20ModulesGenerator should only be used with C++20 Named modules.");121 return M;122}123 124void CXX20ModulesGenerator::HandleTranslationUnit(ASTContext &Ctx) {125 PCHGenerator::HandleTranslationUnit(Ctx);126 127 if (!isComplete())128 return;129 130 std::error_code EC;131 auto OS = std::make_unique<llvm::raw_fd_ostream>(getOutputFile(), EC);132 if (EC) {133 getDiagnostics().Report(diag::err_fe_unable_to_open_output)134 << getOutputFile() << EC.message() << "\n";135 return;136 }137 138 *OS << getBufferPtr()->Data;139 OS->flush();140}141 142void CXX20ModulesGenerator::anchor() {}143 144void ReducedBMIGenerator::anchor() {}145