//===--- ObjectFilePCHContainerOperations.cpp -----------------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #include "clang/CodeGen/ObjectFilePCHContainerOperations.h" #include "CGDebugInfo.h" #include "CodeGenModule.h" #include "clang/AST/ASTContext.h" #include "clang/AST/DeclObjC.h" #include "clang/AST/Expr.h" #include "clang/AST/RecursiveASTVisitor.h" #include "clang/Basic/Diagnostic.h" #include "clang/Basic/TargetInfo.h" #include "clang/CodeGen/BackendUtil.h" #include "clang/Frontend/CodeGenOptions.h" #include "clang/Frontend/CompilerInstance.h" #include "clang/Lex/Preprocessor.h" #include "clang/Lex/HeaderSearch.h" #include "clang/Serialization/ASTWriter.h" #include "llvm/ADT/StringRef.h" #include "llvm/Bitcode/BitstreamReader.h" #include "llvm/DebugInfo/DWARF/DWARFContext.h" #include "llvm/IR/Constants.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/LLVMContext.h" #include "llvm/IR/Module.h" #include "llvm/Object/COFF.h" #include "llvm/Object/ObjectFile.h" #include "llvm/Support/TargetRegistry.h" #include <memory> using namespace clang; #define DEBUG_TYPE "pchcontainer" namespace { class PCHContainerGenerator : public ASTConsumer { DiagnosticsEngine &Diags; const std::string MainFileName; ASTContext *Ctx; ModuleMap &MMap; const HeaderSearchOptions &HeaderSearchOpts; const PreprocessorOptions &PreprocessorOpts; CodeGenOptions CodeGenOpts; const TargetOptions TargetOpts; const LangOptions LangOpts; std::unique_ptr<llvm::LLVMContext> VMContext; std::unique_ptr<llvm::Module> M; std::unique_ptr<CodeGen::CodeGenModule> Builder; raw_pwrite_stream *OS; std::shared_ptr<PCHBuffer> Buffer; /// Visit every type and emit debug info for it. struct DebugTypeVisitor : public RecursiveASTVisitor<DebugTypeVisitor> { clang::CodeGen::CGDebugInfo &DI; ASTContext &Ctx; DebugTypeVisitor(clang::CodeGen::CGDebugInfo &DI, ASTContext &Ctx) : DI(DI), Ctx(Ctx) {} /// Determine whether this type can be represented in DWARF. static bool CanRepresent(const Type *Ty) { return !Ty->isDependentType() && !Ty->isUndeducedType(); } bool VisitImportDecl(ImportDecl *D) { auto *Import = cast<ImportDecl>(D); if (!Import->getImportedOwningModule()) DI.EmitImportDecl(*Import); return true; } bool VisitTypeDecl(TypeDecl *D) { QualType QualTy = Ctx.getTypeDeclType(D); if (!QualTy.isNull() && CanRepresent(QualTy.getTypePtr())) DI.getOrCreateStandaloneType(QualTy, D->getLocation()); return true; } bool VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) { QualType QualTy(D->getTypeForDecl(), 0); if (!QualTy.isNull() && CanRepresent(QualTy.getTypePtr())) DI.getOrCreateStandaloneType(QualTy, D->getLocation()); return true; } bool VisitFunctionDecl(FunctionDecl *D) { if (isa<CXXMethodDecl>(D)) // This is not yet supported. Constructing the `this' argument // mandates a CodeGenFunction. return true; SmallVector<QualType, 16> ArgTypes; for (auto i : D->params()) ArgTypes.push_back(i->getType()); QualType RetTy = D->getReturnType(); QualType FnTy = Ctx.getFunctionType(RetTy, ArgTypes, FunctionProtoType::ExtProtoInfo()); if (CanRepresent(FnTy.getTypePtr())) DI.EmitFunctionDecl(D, D->getLocation(), FnTy); return true; } bool VisitObjCMethodDecl(ObjCMethodDecl *D) { if (!D->getClassInterface()) return true; bool selfIsPseudoStrong, selfIsConsumed; SmallVector<QualType, 16> ArgTypes; ArgTypes.push_back(D->getSelfType(Ctx, D->getClassInterface(), selfIsPseudoStrong, selfIsConsumed)); ArgTypes.push_back(Ctx.getObjCSelType()); for (auto i : D->params()) ArgTypes.push_back(i->getType()); QualType RetTy = D->getReturnType(); QualType FnTy = Ctx.getFunctionType(RetTy, ArgTypes, FunctionProtoType::ExtProtoInfo()); if (CanRepresent(FnTy.getTypePtr())) DI.EmitFunctionDecl(D, D->getLocation(), FnTy); return true; } }; public: PCHContainerGenerator(CompilerInstance &CI, const std::string &MainFileName, const std::string &OutputFileName, raw_pwrite_stream *OS, std::shared_ptr<PCHBuffer> Buffer) : Diags(CI.getDiagnostics()), Ctx(nullptr), MMap(CI.getPreprocessor().getHeaderSearchInfo().getModuleMap()), HeaderSearchOpts(CI.getHeaderSearchOpts()), PreprocessorOpts(CI.getPreprocessorOpts()), TargetOpts(CI.getTargetOpts()), LangOpts(CI.getLangOpts()), OS(OS), Buffer(Buffer) { // The debug info output isn't affected by CodeModel and // ThreadModel, but the backend expects them to be nonempty. CodeGenOpts.CodeModel = "default"; CodeGenOpts.ThreadModel = "single"; CodeGenOpts.DebugTypeExtRefs = true; CodeGenOpts.setDebugInfo(CodeGenOptions::FullDebugInfo); } ~PCHContainerGenerator() override = default; void Initialize(ASTContext &Context) override { assert(!Ctx && "initialized multiple times"); Ctx = &Context; VMContext.reset(new llvm::LLVMContext()); M.reset(new llvm::Module(MainFileName, *VMContext)); M->setDataLayout(Ctx->getTargetInfo().getDataLayoutString()); Builder.reset(new CodeGen::CodeGenModule( *Ctx, HeaderSearchOpts, PreprocessorOpts, CodeGenOpts, *M, Diags)); Builder->getModuleDebugInfo()->setModuleMap(MMap); } bool HandleTopLevelDecl(DeclGroupRef D) override { if (Diags.hasErrorOccurred()) return true; // Collect debug info for all decls in this group. for (auto *I : D) if (!I->isFromASTFile()) { DebugTypeVisitor DTV(*Builder->getModuleDebugInfo(), *Ctx); DTV.TraverseDecl(I); } return true; } void HandleTopLevelDeclInObjCContainer(DeclGroupRef D) override { HandleTopLevelDecl(D); } void HandleTagDeclDefinition(TagDecl *D) override { if (Diags.hasErrorOccurred()) return; Builder->UpdateCompletedType(D); } void HandleTagDeclRequiredDefinition(const TagDecl *D) override { if (Diags.hasErrorOccurred()) return; if (const RecordDecl *RD = dyn_cast<RecordDecl>(D)) Builder->getModuleDebugInfo()->completeRequiredType(RD); } /// Emit a container holding the serialized AST. void HandleTranslationUnit(ASTContext &Ctx) override { assert(M && VMContext && Builder); // Delete these on function exit. std::unique_ptr<llvm::LLVMContext> VMContext = std::move(this->VMContext); std::unique_ptr<llvm::Module> M = std::move(this->M); std::unique_ptr<CodeGen::CodeGenModule> Builder = std::move(this->Builder); if (Diags.hasErrorOccurred()) return; M->setTargetTriple(Ctx.getTargetInfo().getTriple().getTriple()); M->setDataLayout(Ctx.getTargetInfo().getDataLayoutString()); Builder->getModuleDebugInfo()->setDwoId(Buffer->Signature); // Finalize the Builder. if (Builder) Builder->Release(); // Ensure the target exists. std::string Error; auto Triple = Ctx.getTargetInfo().getTriple(); if (!llvm::TargetRegistry::lookupTarget(Triple.getTriple(), Error)) llvm::report_fatal_error(Error); // Emit the serialized Clang AST into its own section. assert(Buffer->IsComplete && "serialization did not complete"); auto &SerializedAST = Buffer->Data; auto Size = SerializedAST.size(); auto Int8Ty = llvm::Type::getInt8Ty(*VMContext); auto *Ty = llvm::ArrayType::get(Int8Ty, Size); auto *Data = llvm::ConstantDataArray::getString( *VMContext, StringRef(SerializedAST.data(), Size), /*AddNull=*/false); auto *ASTSym = new llvm::GlobalVariable( *M, Ty, /*constant*/ true, llvm::GlobalVariable::InternalLinkage, Data, "__clang_ast"); // The on-disk hashtable needs to be aligned. ASTSym->setAlignment(8); // Mach-O also needs a segment name. if (Triple.isOSBinFormatMachO()) ASTSym->setSection("__CLANG,__clangast"); // COFF has an eight character length limit. else if (Triple.isOSBinFormatCOFF()) ASTSym->setSection("clangast"); else ASTSym->setSection("__clangast"); DEBUG({ // Print the IR for the PCH container to the debug output. llvm::SmallString<0> Buffer; llvm::raw_svector_ostream OS(Buffer); clang::EmitBackendOutput(Diags, CodeGenOpts, TargetOpts, LangOpts, Ctx.getTargetInfo().getDataLayoutString(), M.get(), BackendAction::Backend_EmitLL, &OS); llvm::dbgs() << Buffer; }); // Use the LLVM backend to emit the pch container. clang::EmitBackendOutput(Diags, CodeGenOpts, TargetOpts, LangOpts, Ctx.getTargetInfo().getDataLayoutString(), M.get(), BackendAction::Backend_EmitObj, OS); // Make sure the pch container hits disk. OS->flush(); // Free the memory for the temporary buffer. llvm::SmallVector<char, 0> Empty; SerializedAST = std::move(Empty); } }; } // anonymous namespace std::unique_ptr<ASTConsumer> ObjectFilePCHContainerWriter::CreatePCHContainerGenerator( CompilerInstance &CI, const std::string &MainFileName, const std::string &OutputFileName, llvm::raw_pwrite_stream *OS, std::shared_ptr<PCHBuffer> Buffer) const { return llvm::make_unique<PCHContainerGenerator>(CI, MainFileName, OutputFileName, OS, Buffer); } void ObjectFilePCHContainerReader::ExtractPCH( llvm::MemoryBufferRef Buffer, llvm::BitstreamReader &StreamFile) const { if (auto OF = llvm::object::ObjectFile::createObjectFile(Buffer)) { auto *Obj = OF.get().get(); bool IsCOFF = isa<llvm::object::COFFObjectFile>(Obj); // Find the clang AST section in the container. for (auto &Section : OF->get()->sections()) { StringRef Name; Section.getName(Name); if ((!IsCOFF && Name == "__clangast") || ( IsCOFF && Name == "clangast")) { StringRef Buf; Section.getContents(Buf); StreamFile.init((const unsigned char *)Buf.begin(), (const unsigned char *)Buf.end()); return; } } } // As a fallback, treat the buffer as a raw AST. StreamFile.init((const unsigned char *)Buffer.getBufferStart(), (const unsigned char *)Buffer.getBufferEnd()); }