Coverage Report

Created: 2022-05-17 06:19

/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/lib/CodeGen/ObjectFilePCHContainerOperations.cpp
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//===--- ObjectFilePCHContainerOperations.cpp -----------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "clang/CodeGen/ObjectFilePCHContainerOperations.h"
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#include "CGDebugInfo.h"
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#include "CodeGenModule.h"
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#include "clang/AST/ASTContext.h"
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#include "clang/AST/DeclObjC.h"
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#include "clang/AST/Expr.h"
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#include "clang/AST/RecursiveASTVisitor.h"
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#include "clang/Basic/CodeGenOptions.h"
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#include "clang/Basic/Diagnostic.h"
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#include "clang/Basic/TargetInfo.h"
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#include "clang/CodeGen/BackendUtil.h"
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#include "clang/Frontend/CompilerInstance.h"
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#include "clang/Lex/HeaderSearch.h"
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#include "clang/Lex/Preprocessor.h"
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#include "llvm/ADT/StringRef.h"
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#include "llvm/Bitstream/BitstreamReader.h"
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#include "llvm/DebugInfo/DWARF/DWARFContext.h"
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#include "llvm/IR/Constants.h"
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#include "llvm/IR/DataLayout.h"
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#include "llvm/IR/LLVMContext.h"
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#include "llvm/IR/Module.h"
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#include "llvm/MC/TargetRegistry.h"
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#include "llvm/Object/COFF.h"
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#include "llvm/Object/ObjectFile.h"
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#include "llvm/Support/Path.h"
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#include <memory>
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#include <utility>
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using namespace clang;
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#define DEBUG_TYPE "pchcontainer"
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namespace {
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class PCHContainerGenerator : public ASTConsumer {
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  DiagnosticsEngine &Diags;
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  const std::string MainFileName;
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  const std::string OutputFileName;
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  ASTContext *Ctx;
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  ModuleMap &MMap;
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  const HeaderSearchOptions &HeaderSearchOpts;
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  const PreprocessorOptions &PreprocessorOpts;
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  CodeGenOptions CodeGenOpts;
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  const TargetOptions TargetOpts;
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  LangOptions LangOpts;
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  std::unique_ptr<llvm::LLVMContext> VMContext;
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  std::unique_ptr<llvm::Module> M;
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  std::unique_ptr<CodeGen::CodeGenModule> Builder;
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  std::unique_ptr<raw_pwrite_stream> OS;
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  std::shared_ptr<PCHBuffer> Buffer;
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  /// Visit every type and emit debug info for it.
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  struct DebugTypeVisitor : public RecursiveASTVisitor<DebugTypeVisitor> {
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    clang::CodeGen::CGDebugInfo &DI;
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    ASTContext &Ctx;
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    DebugTypeVisitor(clang::CodeGen::CGDebugInfo &DI, ASTContext &Ctx)
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228k
        : DI(DI), Ctx(Ctx) {}
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    /// Determine whether this type can be represented in DWARF.
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557k
    static bool CanRepresent(const Type *Ty) {
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557k
      return !Ty->isDependentType() && 
!Ty->isUndeducedType()329k
;
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557k
    }
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71
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    bool VisitImportDecl(ImportDecl *D) {
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      if (!D->getImportedOwningModule())
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7
        DI.EmitImportDecl(*D);
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7
      return true;
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7
    }
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    bool VisitTypeDecl(TypeDecl *D) {
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      // TagDecls may be deferred until after all decls have been merged and we
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      // know the complete type. Pure forward declarations will be skipped, but
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      // they don't need to be emitted into the module anyway.
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401k
      if (auto *TD = dyn_cast<TagDecl>(D))
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148k
        if (!TD->isCompleteDefinition())
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14.9k
          return true;
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      QualType QualTy = Ctx.getTypeDeclType(D);
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      if (!QualTy.isNull() && CanRepresent(QualTy.getTypePtr()))
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180k
        DI.getOrCreateStandaloneType(QualTy, D->getLocation());
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      return true;
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    }
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4.82k
    bool VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
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4.82k
      QualType QualTy(D->getTypeForDecl(), 0);
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4.82k
      if (!QualTy.isNull() && CanRepresent(QualTy.getTypePtr()))
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4.82k
        DI.getOrCreateStandaloneType(QualTy, D->getLocation());
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4.82k
      return true;
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    }
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296k
    bool VisitFunctionDecl(FunctionDecl *D) {
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      if (isa<CXXMethodDecl>(D))
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        // This is not yet supported. Constructing the `this' argument
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        // mandates a CodeGenFunction.
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        return true;
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      SmallVector<QualType, 16> ArgTypes;
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      for (auto i : D->parameters())
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        ArgTypes.push_back(i->getType());
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      QualType RetTy = D->getReturnType();
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      QualType FnTy = Ctx.getFunctionType(RetTy, ArgTypes,
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                                          FunctionProtoType::ExtProtoInfo());
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      if (CanRepresent(FnTy.getTypePtr()))
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        DI.EmitFunctionDecl(D, D->getLocation(), FnTy);
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      return true;
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    }
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    bool VisitObjCMethodDecl(ObjCMethodDecl *D) {
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16.7k
      if (!D->getClassInterface())
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        return true;
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14.6k
      bool selfIsPseudoStrong, selfIsConsumed;
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14.6k
      SmallVector<QualType, 16> ArgTypes;
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14.6k
      ArgTypes.push_back(D->getSelfType(Ctx, D->getClassInterface(),
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                                        selfIsPseudoStrong, selfIsConsumed));
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      ArgTypes.push_back(Ctx.getObjCSelType());
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      for (auto i : D->parameters())
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        ArgTypes.push_back(i->getType());
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      QualType RetTy = D->getReturnType();
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      QualType FnTy = Ctx.getFunctionType(RetTy, ArgTypes,
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                                          FunctionProtoType::ExtProtoInfo());
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14.6k
      if (CanRepresent(FnTy.getTypePtr()))
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        DI.EmitFunctionDecl(D, D->getLocation(), FnTy);
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      return true;
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    }
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  };
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public:
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  PCHContainerGenerator(CompilerInstance &CI, const std::string &MainFileName,
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                        const std::string &OutputFileName,
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                        std::unique_ptr<raw_pwrite_stream> OS,
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                        std::shared_ptr<PCHBuffer> Buffer)
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      : Diags(CI.getDiagnostics()), MainFileName(MainFileName),
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        OutputFileName(OutputFileName), Ctx(nullptr),
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        MMap(CI.getPreprocessor().getHeaderSearchInfo().getModuleMap()),
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        HeaderSearchOpts(CI.getHeaderSearchOpts()),
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        PreprocessorOpts(CI.getPreprocessorOpts()),
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        TargetOpts(CI.getTargetOpts()), LangOpts(CI.getLangOpts()),
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        OS(std::move(OS)), Buffer(std::move(Buffer)) {
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    // The debug info output isn't affected by CodeModel and
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    // ThreadModel, but the backend expects them to be nonempty.
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    CodeGenOpts.CodeModel = "default";
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    LangOpts.setThreadModel(LangOptions::ThreadModelKind::Single);
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    CodeGenOpts.DebugTypeExtRefs = true;
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    // When building a module MainFileName is the name of the modulemap file.
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    CodeGenOpts.MainFileName =
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        LangOpts.CurrentModule.empty() ? 
MainFileName15
:
LangOpts.CurrentModule312
;
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    CodeGenOpts.setDebugInfo(codegenoptions::FullDebugInfo);
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    CodeGenOpts.setDebuggerTuning(CI.getCodeGenOpts().getDebuggerTuning());
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    CodeGenOpts.DebugPrefixMap =
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        CI.getInvocation().getCodeGenOpts().DebugPrefixMap;
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    CodeGenOpts.DebugStrictDwarf = CI.getCodeGenOpts().DebugStrictDwarf;
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  }
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  ~PCHContainerGenerator() override = default;
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  void Initialize(ASTContext &Context) override {
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    assert(!Ctx && "initialized multiple times");
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    Ctx = &Context;
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    VMContext.reset(new llvm::LLVMContext());
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    M.reset(new llvm::Module(MainFileName, *VMContext));
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    M->setDataLayout(Ctx->getTargetInfo().getDataLayoutString());
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    Builder.reset(new CodeGen::CodeGenModule(
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        *Ctx, HeaderSearchOpts, PreprocessorOpts, CodeGenOpts, *M, Diags));
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    // Prepare CGDebugInfo to emit debug info for a clang module.
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    auto *DI = Builder->getModuleDebugInfo();
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    StringRef ModuleName = llvm::sys::path::filename(MainFileName);
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    DI->setPCHDescriptor(
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        {ModuleName, "", OutputFileName, ASTFileSignature::createDISentinel()});
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    DI->setModuleMap(MMap);
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  }
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150k
  bool HandleTopLevelDecl(DeclGroupRef D) override {
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150k
    if (Diags.hasErrorOccurred())
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0
      return true;
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    // Collect debug info for all decls in this group.
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    for (auto *I : D)
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      if (!I->isFromASTFile()) {
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        DebugTypeVisitor DTV(*Builder->getModuleDebugInfo(), *Ctx);
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        DTV.TraverseDecl(I);
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      }
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    return true;
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  }
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935
  void HandleTopLevelDeclInObjCContainer(DeclGroupRef D) override {
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    HandleTopLevelDecl(D);
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  }
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95.0k
  void HandleTagDeclDefinition(TagDecl *D) override {
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95.0k
    if (Diags.hasErrorOccurred())
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0
      return;
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95.0k
    if (D->isFromASTFile())
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1
      return;
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    // Anonymous tag decls are deferred until we are building their declcontext.
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    if (D->getName().empty())
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      return;
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    // Defer tag decls until their declcontext is complete.
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    auto *DeclCtx = D->getDeclContext();
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    while (DeclCtx) {
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      if (auto *D = dyn_cast<TagDecl>(DeclCtx))
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        if (!D->isCompleteDefinition())
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          return;
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      DeclCtx = DeclCtx->getParent();
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    }
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    DebugTypeVisitor DTV(*Builder->getModuleDebugInfo(), *Ctx);
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    DTV.TraverseDecl(D);
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    Builder->UpdateCompletedType(D);
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  }
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  void HandleTagDeclRequiredDefinition(const TagDecl *D) override {
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    if (Diags.hasErrorOccurred())
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      return;
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    if (const RecordDecl *RD = dyn_cast<RecordDecl>(D))
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      Builder->getModuleDebugInfo()->completeRequiredType(RD);
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  }
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  void HandleImplicitImportDecl(ImportDecl *D) override {
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    if (!D->getImportedOwningModule())
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      Builder->getModuleDebugInfo()->EmitImportDecl(*D);
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  }
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  /// Emit a container holding the serialized AST.
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  void HandleTranslationUnit(ASTContext &Ctx) override {
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    assert(M && VMContext && Builder);
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    // Delete these on function exit.
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    std::unique_ptr<llvm::LLVMContext> VMContext = std::move(this->VMContext);
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    std::unique_ptr<llvm::Module> M = std::move(this->M);
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    std::unique_ptr<CodeGen::CodeGenModule> Builder = std::move(this->Builder);
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    if (Diags.hasErrorOccurred())
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0
      return;
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    M->setTargetTriple(Ctx.getTargetInfo().getTriple().getTriple());
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    M->setDataLayout(Ctx.getTargetInfo().getDataLayoutString());
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    // PCH files don't have a signature field in the control block,
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    // but LLVM detects DWO CUs by looking for a non-zero DWO id.
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    // We use the lower 64 bits for debug info.
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    uint64_t Signature =
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        Buffer->Signature ? 
Buffer->Signature.truncatedValue()283
:
~1ULL44
;
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    Builder->getModuleDebugInfo()->setDwoId(Signature);
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    // Finalize the Builder.
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    if (Builder)
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      Builder->Release();
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    // Ensure the target exists.
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    std::string Error;
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327
    auto Triple = Ctx.getTargetInfo().getTriple();
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327
    if (!llvm::TargetRegistry::lookupTarget(Triple.getTriple(), Error))
268
0
      llvm::report_fatal_error(llvm::Twine(Error));
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    // Emit the serialized Clang AST into its own section.
271
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    assert(Buffer->IsComplete && "serialization did not complete");
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    auto &SerializedAST = Buffer->Data;
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327
    auto Size = SerializedAST.size();
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275
327
    if (Triple.isOSBinFormatWasm()) {
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      // Emit __clangast in custom section instead of named data segment
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      // to find it while iterating sections.
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      // This could be avoided if all data segements (the wasm sense) were
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      // represented as their own sections (in the llvm sense).
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      // TODO: https://github.com/WebAssembly/tool-conventions/issues/138
281
0
      llvm::NamedMDNode *MD =
282
0
          M->getOrInsertNamedMetadata("wasm.custom_sections");
283
0
      llvm::Metadata *Ops[2] = {
284
0
          llvm::MDString::get(*VMContext, "__clangast"),
285
0
          llvm::MDString::get(*VMContext,
286
0
                              StringRef(SerializedAST.data(), Size))};
287
0
      auto *NameAndContent = llvm::MDTuple::get(*VMContext, Ops);
288
0
      MD->addOperand(NameAndContent);
289
327
    } else {
290
327
      auto Int8Ty = llvm::Type::getInt8Ty(*VMContext);
291
327
      auto *Ty = llvm::ArrayType::get(Int8Ty, Size);
292
327
      auto *Data = llvm::ConstantDataArray::getString(
293
327
          *VMContext, StringRef(SerializedAST.data(), Size),
294
327
          /*AddNull=*/false);
295
327
      auto *ASTSym = new llvm::GlobalVariable(
296
327
          *M, Ty, /*constant*/ true, llvm::GlobalVariable::InternalLinkage,
297
327
          Data, "__clang_ast");
298
      // The on-disk hashtable needs to be aligned.
299
327
      ASTSym->setAlignment(llvm::Align(8));
300
301
      // Mach-O also needs a segment name.
302
327
      if (Triple.isOSBinFormatMachO())
303
323
        ASTSym->setSection("__CLANG,__clangast");
304
      // COFF has an eight character length limit.
305
4
      else if (Triple.isOSBinFormatCOFF())
306
2
        ASTSym->setSection("clangast");
307
2
      else
308
2
        ASTSym->setSection("__clangast");
309
327
    }
310
311
327
    LLVM_DEBUG({
312
      // Print the IR for the PCH container to the debug output.
313
327
      llvm::SmallString<0> Buffer;
314
327
      clang::EmitBackendOutput(
315
327
          Diags, HeaderSearchOpts, CodeGenOpts, TargetOpts, LangOpts,
316
327
          Ctx.getTargetInfo().getDataLayoutString(), M.get(),
317
327
          BackendAction::Backend_EmitLL,
318
327
          std::make_unique<llvm::raw_svector_ostream>(Buffer));
319
327
      llvm::dbgs() << Buffer;
320
327
    });
321
322
    // Use the LLVM backend to emit the pch container.
323
327
    clang::EmitBackendOutput(Diags, HeaderSearchOpts, CodeGenOpts, TargetOpts,
324
327
                             LangOpts,
325
327
                             Ctx.getTargetInfo().getDataLayoutString(), M.get(),
326
327
                             BackendAction::Backend_EmitObj, std::move(OS));
327
328
    // Free the memory for the temporary buffer.
329
327
    llvm::SmallVector<char, 0> Empty;
330
327
    SerializedAST = std::move(Empty);
331
327
  }
332
};
333
334
} // anonymous namespace
335
336
std::unique_ptr<ASTConsumer>
337
ObjectFilePCHContainerWriter::CreatePCHContainerGenerator(
338
    CompilerInstance &CI, const std::string &MainFileName,
339
    const std::string &OutputFileName,
340
    std::unique_ptr<llvm::raw_pwrite_stream> OS,
341
327
    std::shared_ptr<PCHBuffer> Buffer) const {
342
327
  return std::make_unique<PCHContainerGenerator>(
343
327
      CI, MainFileName, OutputFileName, std::move(OS), Buffer);
344
327
}
345
346
StringRef
347
11.4k
ObjectFilePCHContainerReader::ExtractPCH(llvm::MemoryBufferRef Buffer) const {
348
11.4k
  StringRef PCH;
349
11.4k
  auto OFOrErr = llvm::object::ObjectFile::createObjectFile(Buffer);
350
11.4k
  if (OFOrErr) {
351
9.09k
    auto &OF = OFOrErr.get();
352
9.09k
    bool IsCOFF = isa<llvm::object::COFFObjectFile>(*OF);
353
    // Find the clang AST section in the container.
354
18.2k
    for (auto &Section : OF->sections()) {
355
18.2k
      StringRef Name;
356
18.2k
      if (Expected<StringRef> NameOrErr = Section.getName())
357
18.2k
        Name = *NameOrErr;
358
0
      else
359
0
        consumeError(NameOrErr.takeError());
360
361
18.2k
      if ((!IsCOFF && 
Name == "__clangast"18.1k
) ||
(9.10k
IsCOFF9.10k
&&
Name == "clangast"8
)) {
362
9.09k
        if (Expected<StringRef> E = Section.getContents())
363
9.09k
          return *E;
364
0
        else {
365
0
          handleAllErrors(E.takeError(), [&](const llvm::ErrorInfoBase &EIB) {
366
0
            EIB.log(llvm::errs());
367
0
          });
368
0
          return "";
369
0
        }
370
9.09k
      }
371
18.2k
    }
372
9.09k
  }
373
2.39k
  handleAllErrors(OFOrErr.takeError(), [&](const llvm::ErrorInfoBase &EIB) {
374
2.39k
    if (EIB.convertToErrorCode() ==
375
2.39k
        llvm::object::object_error::invalid_file_type)
376
      // As a fallback, treat the buffer as a raw AST.
377
2.39k
      PCH = Buffer.getBuffer();
378
0
    else
379
0
      EIB.log(llvm::errs());
380
2.39k
  });
381
2.39k
  return PCH;
382
11.4k
}