C++ Linker::linkInModule方法代码示例

static bool linkFiles(const char *argv0, LLVMContext &Context, Linker &L,
                      const cl::list<std::string> &Files,
                      unsigned Flags) {
  // Filter out flags that don't apply to the first file we load.
  unsigned ApplicableFlags = Flags & Linker::Flags::OverrideFromSrc;
  for (const auto &File : Files) {
    std::unique_ptr<Module> M = loadFile(argv0, File, Context);
    if (!M.get()) {
      errs() << argv0 << ": error loading file '" << File << "'\n";
      return false;
    }

    if (verifyModule(*M, &errs())) {
      errs() << argv0 << ": " << File << ": error: input module is broken!\n";
      return false;
    }

    if (Verbose)
      errs() << "Linking in '" << File << "'\n";

    if (L.linkInModule(M.get(), ApplicableFlags))
      return false;
    // All linker flags apply to linking of subsequent files.
    ApplicableFlags = Flags;
  }

  return true;
}

static bool linkFiles(const char *argv0, LLVMContext &Context, Linker &L,
                      const cl::list<std::string> &Files,
                      unsigned Flags) {
  // Filter out flags that don't apply to the first file we load.
  unsigned ApplicableFlags = Flags & Linker::Flags::OverrideFromSrc;
  for (const auto &File : Files) {
    std::unique_ptr<Module> M = loadFile(argv0, File, Context);
    if (!M.get()) {
      errs() << argv0 << ": error loading file '" << File << "'\n";
      return false;
    }

    // Note that when ODR merging types cannot verify input files in here When
    // doing that debug metadata in the src module might already be pointing to
    // the destination.
    if (DisableDITypeMap && verifyModule(*M, &errs())) {
      errs() << argv0 << ": " << File << ": error: input module is broken!\n";
      return false;
    }

    // If a module summary index is supplied, load it so linkInModule can treat
    // local functions/variables as exported and promote if necessary.
    if (!SummaryIndex.empty()) {
      std::unique_ptr<ModuleSummaryIndex> Index =
          ExitOnErr(llvm::getModuleSummaryIndexForFile(SummaryIndex));

      // Conservatively mark all internal values as promoted, since this tool
      // does not do the ThinLink that would normally determine what values to
      // promote.
      for (auto &I : *Index) {
        for (auto &S : I.second) {
          if (GlobalValue::isLocalLinkage(S->linkage()))
            S->setLinkage(GlobalValue::ExternalLinkage);
        }
      }

      // Promotion
      if (renameModuleForThinLTO(*M, *Index))
        return true;
    }

    if (Verbose)
      errs() << "Linking in '" << File << "'\n";

    if (L.linkInModule(std::move(M), ApplicableFlags))
      return false;
    // All linker flags apply to linking of subsequent files.
    ApplicableFlags = Flags;
  }

  return true;
}

static bool linkFiles(const char *argv0, LLVMContext &Context, Linker &L,
                      const cl::list<std::string> &Files,
                      unsigned Flags) {
  // Filter out flags that don't apply to the first file we load.
  unsigned ApplicableFlags = Flags & Linker::Flags::OverrideFromSrc;
  for (const auto &File : Files) {
    std::unique_ptr<Module> M = loadFile(argv0, File, Context);
    if (!M.get()) {
      errs() << argv0 << ": error loading file '" << File << "'\n";
      return false;
    }

    if (verifyModule(*M, &errs())) {
      errs() << argv0 << ": " << File << ": error: input module is broken!\n";
      return false;
    }

    // If a function index is supplied, load it so linkInModule can treat
    // local functions/variables as exported and promote if necessary.
    std::unique_ptr<FunctionInfoIndex> Index;
    if (!FunctionIndex.empty()) {
      ErrorOr<std::unique_ptr<FunctionInfoIndex>> IndexOrErr =
          llvm::getFunctionIndexForFile(FunctionIndex, diagnosticHandler);
      std::error_code EC = IndexOrErr.getError();
      if (EC) {
        errs() << EC.message() << '\n';
        return false;
      }
      Index = std::move(IndexOrErr.get());
    }

    if (Verbose)
      errs() << "Linking in '" << File << "'\n";

    if (L.linkInModule(std::move(M), ApplicableFlags, Index.get()))
      return false;
    // All linker flags apply to linking of subsequent files.
    ApplicableFlags = Flags;

    // If requested for testing, preserve modules by releasing them from
    // the unique_ptr before the are freed. This can help catch any
    // cross-module references from e.g. unneeded metadata references
    // that aren't properly set to null but instead mapped to the source
    // module version. The bitcode writer will assert if it finds any such
    // cross-module references.
    if (PreserveModules)
      M.release();
  }

  return true;
}

static bool linkFiles(const char *argv0, LLVMContext &Context, Linker &L,
                      const cl::list<std::string> &Files,
                      unsigned Flags) {
  // Filter out flags that don't apply to the first file we load.
  unsigned ApplicableFlags = Flags & Linker::Flags::OverrideFromSrc;
  for (const auto &File : Files) {
    std::unique_ptr<Module> M = loadFile(argv0, File, Context);
    if (!M.get()) {
      errs() << argv0 << ": error loading file '" << File << "'\n";
      return false;
    }

    // Note that when ODR merging types cannot verify input files in here When
    // doing that debug metadata in the src module might already be pointing to
    // the destination.
    if (DisableDITypeMap && verifyModule(*M, &errs())) {
      errs() << argv0 << ": " << File << ": error: input module is broken!\n";
      return false;
    }

    // If a module summary index is supplied, load it so linkInModule can treat
    // local functions/variables as exported and promote if necessary.
    if (!SummaryIndex.empty()) {
      ErrorOr<std::unique_ptr<ModuleSummaryIndex>> IndexOrErr =
          llvm::getModuleSummaryIndexForFile(SummaryIndex, diagnosticHandler);
      std::error_code EC = IndexOrErr.getError();
      if (EC) {
        errs() << EC.message() << '\n';
        return false;
      }
      auto Index = std::move(IndexOrErr.get());

      // Promotion
      if (renameModuleForThinLTO(*M, *Index))
        return true;
    }

    if (Verbose)
      errs() << "Linking in '" << File << "'\n";

    if (L.linkInModule(std::move(M), ApplicableFlags))
      return false;
    // All linker flags apply to linking of subsequent files.
    ApplicableFlags = Flags;
  }

  return true;
}

/// Import any functions requested via the -import option.
static bool importFunctions(const char *argv0, LLVMContext &Context,
                            Linker &L) {
  StringMap<std::unique_ptr<DenseMap<unsigned, MDNode *>>>
      ModuleToTempMDValsMap;
  for (const auto &Import : Imports) {
    // Identify the requested function and its bitcode source file.
    size_t Idx = Import.find(':');
    if (Idx == std::string::npos) {
      errs() << "Import parameter bad format: " << Import << "\n";
      return false;
    }
    std::string FunctionName = Import.substr(0, Idx);
    std::string FileName = Import.substr(Idx + 1, std::string::npos);

    // Load the specified source module.
    std::unique_ptr<Module> M = loadFile(argv0, FileName, Context, false);
    if (!M.get()) {
      errs() << argv0 << ": error loading file '" << FileName << "'\n";
      return false;
    }

    if (verifyModule(*M, &errs())) {
      errs() << argv0 << ": " << FileName
             << ": error: input module is broken!\n";
      return false;
    }

    Function *F = M->getFunction(FunctionName);
    if (!F) {
      errs() << "Ignoring import request for non-existent function "
             << FunctionName << " from " << FileName << "\n";
      continue;
    }
    // We cannot import weak_any functions without possibly affecting the
    // order they are seen and selected by the linker, changing program
    // semantics.
    if (F->hasWeakAnyLinkage()) {
      errs() << "Ignoring import request for weak-any function " << FunctionName
             << " from " << FileName << "\n";
      continue;
    }

    if (Verbose)
      errs() << "Importing " << FunctionName << " from " << FileName << "\n";

    std::unique_ptr<FunctionInfoIndex> Index;
    if (!FunctionIndex.empty()) {
      ErrorOr<std::unique_ptr<FunctionInfoIndex>> IndexOrErr =
          llvm::getFunctionIndexForFile(FunctionIndex, diagnosticHandler);
      std::error_code EC = IndexOrErr.getError();
      if (EC) {
        errs() << EC.message() << '\n';
        return false;
      }
      Index = std::move(IndexOrErr.get());
    }

    // Save the mapping of value ids to temporary metadata created when
    // importing this function. If we have already imported from this module,
    // add new temporary metadata to the existing mapping.
    auto &TempMDVals = ModuleToTempMDValsMap[FileName];
    if (!TempMDVals)
      TempMDVals = llvm::make_unique<DenseMap<unsigned, MDNode *>>();

    // Link in the specified function.
    DenseSet<const GlobalValue *> FunctionsToImport;
    FunctionsToImport.insert(F);
    if (L.linkInModule(std::move(M), Linker::Flags::None, Index.get(),
                       &FunctionsToImport, TempMDVals.get()))
      return false;
  }

  // Now link in metadata for all modules from which we imported functions.
  for (StringMapEntry<std::unique_ptr<DenseMap<unsigned, MDNode *>>> &SME :
       ModuleToTempMDValsMap) {
    // Load the specified source module.
    std::unique_ptr<Module> M = loadFile(argv0, SME.getKey(), Context, true);
    if (!M.get()) {
      errs() << argv0 << ": error loading file '" << SME.getKey() << "'\n";
      return false;
    }

    if (verifyModule(*M, &errs())) {
      errs() << argv0 << ": " << SME.getKey()
             << ": error: input module is broken!\n";
      return false;
    }

    // Link in all necessary metadata from this module.
    if (L.linkInMetadata(*M, SME.getValue().get()))
      return false;
  }
  return true;
}

/// Import any functions requested via the -import option.
static bool importFunctions(const char *argv0, LLVMContext &Context,
                            Linker &L) {
  if (SummaryIndex.empty())
    return true;
  std::unique_ptr<ModuleSummaryIndex> Index =
      ExitOnErr(llvm::getModuleSummaryIndexForFile(SummaryIndex));

  // Map of Module -> List of globals to import from the Module
  std::map<StringRef, DenseSet<const GlobalValue *>> ModuleToGlobalsToImportMap;
  auto ModuleLoader = [&Context](const char *argv0,
                                 const std::string &Identifier) {
    return loadFile(argv0, Identifier, Context, false);
  };
  ModuleLazyLoaderCache ModuleLoaderCache(ModuleLoader);
  for (const auto &Import : Imports) {
    // Identify the requested function and its bitcode source file.
    size_t Idx = Import.find(':');
    if (Idx == std::string::npos) {
      errs() << "Import parameter bad format: " << Import << "\n";
      return false;
    }
    std::string FunctionName = Import.substr(0, Idx);
    std::string FileName = Import.substr(Idx + 1, std::string::npos);

    // Load the specified source module.
    auto &SrcModule = ModuleLoaderCache(argv0, FileName);

    if (verifyModule(SrcModule, &errs())) {
      errs() << argv0 << ": " << FileName
             << ": error: input module is broken!\n";
      return false;
    }

    Function *F = SrcModule.getFunction(FunctionName);
    if (!F) {
      errs() << "Ignoring import request for non-existent function "
             << FunctionName << " from " << FileName << "\n";
      continue;
    }
    // We cannot import weak_any functions without possibly affecting the
    // order they are seen and selected by the linker, changing program
    // semantics.
    if (F->hasWeakAnyLinkage()) {
      errs() << "Ignoring import request for weak-any function " << FunctionName
             << " from " << FileName << "\n";
      continue;
    }

    if (Verbose)
      errs() << "Importing " << FunctionName << " from " << FileName << "\n";

    auto &Entry = ModuleToGlobalsToImportMap[SrcModule.getModuleIdentifier()];
    Entry.insert(F);

    ExitOnErr(F->materialize());
  }

  // Do the actual import of globals now, one Module at a time
  for (auto &GlobalsToImportPerModule : ModuleToGlobalsToImportMap) {
    // Get the module for the import
    auto &GlobalsToImport = GlobalsToImportPerModule.second;
    std::unique_ptr<Module> SrcModule =
        ModuleLoaderCache.takeModule(GlobalsToImportPerModule.first);
    assert(&Context == &SrcModule->getContext() && "Context mismatch");

    // If modules were created with lazy metadata loading, materialize it
    // now, before linking it (otherwise this will be a noop).
    ExitOnErr(SrcModule->materializeMetadata());
    UpgradeDebugInfo(*SrcModule);

    // Linkage Promotion and renaming
    if (renameModuleForThinLTO(*SrcModule, *Index, &GlobalsToImport))
      return true;

    // Instruct the linker to not automatically import linkonce defintion.
    unsigned Flags = Linker::Flags::DontForceLinkLinkonceODR;

    if (L.linkInModule(std::move(SrcModule), Flags, &GlobalsToImport))
      return false;
  }

  return true;
}

/// Import any functions requested via the -import option.
static bool importFunctions(const char *argv0, LLVMContext &Context,
                            Linker &L) {
  for (const auto &Import : Imports) {
    // Identify the requested function and its bitcode source file.
    size_t Idx = Import.find(':');
    if (Idx == std::string::npos) {
      errs() << "Import parameter bad format: " << Import << "\n";
      return false;
    }
    std::string FunctionName = Import.substr(0, Idx);
    std::string FileName = Import.substr(Idx + 1, std::string::npos);

    // Load the specified source module.
    std::unique_ptr<Module> M = loadFile(argv0, FileName, Context);
    if (!M.get()) {
      errs() << argv0 << ": error loading file '" << FileName << "'\n";
      return false;
    }

    if (verifyModule(*M, &errs())) {
      errs() << argv0 << ": " << FileName
             << ": error: input module is broken!\n";
      return false;
    }

    Function *F = M->getFunction(FunctionName);
    if (!F) {
      errs() << "Ignoring import request for non-existent function "
             << FunctionName << " from " << FileName << "\n";
      continue;
    }
    // We cannot import weak_any functions without possibly affecting the
    // order they are seen and selected by the linker, changing program
    // semantics.
    if (F->hasWeakAnyLinkage()) {
      errs() << "Ignoring import request for weak-any function " << FunctionName
             << " from " << FileName << "\n";
      continue;
    }

    if (Verbose)
      errs() << "Importing " << FunctionName << " from " << FileName << "\n";

    std::unique_ptr<FunctionInfoIndex> Index;
    if (!FunctionIndex.empty()) {
      ErrorOr<std::unique_ptr<FunctionInfoIndex>> IndexOrErr =
          llvm::getFunctionIndexForFile(FunctionIndex, diagnosticHandler);
      std::error_code EC = IndexOrErr.getError();
      if (EC) {
        errs() << EC.message() << '\n';
        return false;
      }
      Index = std::move(IndexOrErr.get());
    }

    // Link in the specified function.
    DenseSet<const GlobalValue *> FunctionsToImport;
    FunctionsToImport.insert(F);
    if (L.linkInModule(*M, Linker::Flags::None, Index.get(),
                       &FunctionsToImport))
      return false;
  }
  return true;
}