704 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			704 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			C++
		
	
	
	
//===-- LTOModule.cpp - LLVM Link Time Optimizer --------------------------===//
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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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//
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// This file implements the Link Time Optimization library. This library is
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// intended to be used by linker to optimize code at link time.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/LTO/legacy/LTOModule.h"
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#include "llvm/ADT/Triple.h"
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#include "llvm/Bitcode/BitcodeReader.h"
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#include "llvm/CodeGen/TargetSubtargetInfo.h"
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#include "llvm/IR/Constants.h"
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#include "llvm/IR/LLVMContext.h"
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#include "llvm/IR/Mangler.h"
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#include "llvm/IR/Metadata.h"
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#include "llvm/IR/Module.h"
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#include "llvm/MC/MCExpr.h"
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#include "llvm/MC/MCInst.h"
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#include "llvm/MC/MCParser/MCAsmParser.h"
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#include "llvm/MC/MCSection.h"
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#include "llvm/MC/MCSubtargetInfo.h"
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#include "llvm/MC/MCSymbol.h"
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#include "llvm/MC/SubtargetFeature.h"
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#include "llvm/MC/TargetRegistry.h"
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#include "llvm/Object/IRObjectFile.h"
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#include "llvm/Object/MachO.h"
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#include "llvm/Object/ObjectFile.h"
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#include "llvm/Support/FileSystem.h"
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#include "llvm/Support/Host.h"
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#include "llvm/Support/MemoryBuffer.h"
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#include "llvm/Support/Path.h"
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#include "llvm/Support/SourceMgr.h"
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#include "llvm/Support/TargetSelect.h"
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#include "llvm/Target/TargetLoweringObjectFile.h"
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#include "llvm/Transforms/Utils/GlobalStatus.h"
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#include <system_error>
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using namespace llvm;
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using namespace llvm::object;
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LTOModule::LTOModule(std::unique_ptr<Module> M, MemoryBufferRef MBRef,
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                     llvm::TargetMachine *TM)
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    : Mod(std::move(M)), MBRef(MBRef), _target(TM) {
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  assert(_target && "target machine is null");
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  SymTab.addModule(Mod.get());
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}
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LTOModule::~LTOModule() {}
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/// isBitcodeFile - Returns 'true' if the file (or memory contents) is LLVM
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/// bitcode.
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bool LTOModule::isBitcodeFile(const void *Mem, size_t Length) {
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  Expected<MemoryBufferRef> BCData = IRObjectFile::findBitcodeInMemBuffer(
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      MemoryBufferRef(StringRef((const char *)Mem, Length), "<mem>"));
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  return !errorToBool(BCData.takeError());
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}
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bool LTOModule::isBitcodeFile(StringRef Path) {
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  ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
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      MemoryBuffer::getFile(Path);
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  if (!BufferOrErr)
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    return false;
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  Expected<MemoryBufferRef> BCData = IRObjectFile::findBitcodeInMemBuffer(
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      BufferOrErr.get()->getMemBufferRef());
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  return !errorToBool(BCData.takeError());
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}
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bool LTOModule::isThinLTO() {
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  Expected<BitcodeLTOInfo> Result = getBitcodeLTOInfo(MBRef);
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  if (!Result) {
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    logAllUnhandledErrors(Result.takeError(), errs());
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    return false;
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  }
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  return Result->IsThinLTO;
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}
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bool LTOModule::isBitcodeForTarget(MemoryBuffer *Buffer,
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                                   StringRef TriplePrefix) {
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  Expected<MemoryBufferRef> BCOrErr =
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      IRObjectFile::findBitcodeInMemBuffer(Buffer->getMemBufferRef());
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  if (errorToBool(BCOrErr.takeError()))
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    return false;
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  LLVMContext Context;
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  ErrorOr<std::string> TripleOrErr =
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      expectedToErrorOrAndEmitErrors(Context, getBitcodeTargetTriple(*BCOrErr));
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  if (!TripleOrErr)
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    return false;
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  return StringRef(*TripleOrErr).startswith(TriplePrefix);
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}
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std::string LTOModule::getProducerString(MemoryBuffer *Buffer) {
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  Expected<MemoryBufferRef> BCOrErr =
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      IRObjectFile::findBitcodeInMemBuffer(Buffer->getMemBufferRef());
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  if (errorToBool(BCOrErr.takeError()))
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    return "";
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  LLVMContext Context;
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  ErrorOr<std::string> ProducerOrErr = expectedToErrorOrAndEmitErrors(
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      Context, getBitcodeProducerString(*BCOrErr));
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  if (!ProducerOrErr)
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    return "";
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  return *ProducerOrErr;
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}
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ErrorOr<std::unique_ptr<LTOModule>>
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LTOModule::createFromFile(LLVMContext &Context, StringRef path,
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                          const TargetOptions &options) {
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  ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
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      MemoryBuffer::getFile(path);
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  if (std::error_code EC = BufferOrErr.getError()) {
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    Context.emitError(EC.message());
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    return EC;
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  }
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  std::unique_ptr<MemoryBuffer> Buffer = std::move(BufferOrErr.get());
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  return makeLTOModule(Buffer->getMemBufferRef(), options, Context,
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                       /* ShouldBeLazy*/ false);
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}
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ErrorOr<std::unique_ptr<LTOModule>>
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LTOModule::createFromOpenFile(LLVMContext &Context, int fd, StringRef path,
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                              size_t size, const TargetOptions &options) {
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  return createFromOpenFileSlice(Context, fd, path, size, 0, options);
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}
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ErrorOr<std::unique_ptr<LTOModule>>
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LTOModule::createFromOpenFileSlice(LLVMContext &Context, int fd, StringRef path,
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                                   size_t map_size, off_t offset,
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                                   const TargetOptions &options) {
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  ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
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      MemoryBuffer::getOpenFileSlice(sys::fs::convertFDToNativeFile(fd), path,
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                                     map_size, offset);
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  if (std::error_code EC = BufferOrErr.getError()) {
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    Context.emitError(EC.message());
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    return EC;
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  }
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  std::unique_ptr<MemoryBuffer> Buffer = std::move(BufferOrErr.get());
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  return makeLTOModule(Buffer->getMemBufferRef(), options, Context,
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                       /* ShouldBeLazy */ false);
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}
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ErrorOr<std::unique_ptr<LTOModule>>
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LTOModule::createFromBuffer(LLVMContext &Context, const void *mem,
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                            size_t length, const TargetOptions &options,
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                            StringRef path) {
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  StringRef Data((const char *)mem, length);
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  MemoryBufferRef Buffer(Data, path);
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  return makeLTOModule(Buffer, options, Context, /* ShouldBeLazy */ false);
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}
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ErrorOr<std::unique_ptr<LTOModule>>
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LTOModule::createInLocalContext(std::unique_ptr<LLVMContext> Context,
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                                const void *mem, size_t length,
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                                const TargetOptions &options, StringRef path) {
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  StringRef Data((const char *)mem, length);
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  MemoryBufferRef Buffer(Data, path);
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  // If we own a context, we know this is being used only for symbol extraction,
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  // not linking.  Be lazy in that case.
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  ErrorOr<std::unique_ptr<LTOModule>> Ret =
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      makeLTOModule(Buffer, options, *Context, /* ShouldBeLazy */ true);
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  if (Ret)
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    (*Ret)->OwnedContext = std::move(Context);
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  return Ret;
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}
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static ErrorOr<std::unique_ptr<Module>>
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parseBitcodeFileImpl(MemoryBufferRef Buffer, LLVMContext &Context,
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                     bool ShouldBeLazy) {
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  // Find the buffer.
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  Expected<MemoryBufferRef> MBOrErr =
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      IRObjectFile::findBitcodeInMemBuffer(Buffer);
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  if (Error E = MBOrErr.takeError()) {
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    std::error_code EC = errorToErrorCode(std::move(E));
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    Context.emitError(EC.message());
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    return EC;
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  }
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  if (!ShouldBeLazy) {
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    // Parse the full file.
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    return expectedToErrorOrAndEmitErrors(Context,
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                                          parseBitcodeFile(*MBOrErr, Context));
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  }
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  // Parse lazily.
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  return expectedToErrorOrAndEmitErrors(
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      Context,
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      getLazyBitcodeModule(*MBOrErr, Context, true /*ShouldLazyLoadMetadata*/));
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}
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ErrorOr<std::unique_ptr<LTOModule>>
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LTOModule::makeLTOModule(MemoryBufferRef Buffer, const TargetOptions &options,
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                         LLVMContext &Context, bool ShouldBeLazy) {
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  ErrorOr<std::unique_ptr<Module>> MOrErr =
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      parseBitcodeFileImpl(Buffer, Context, ShouldBeLazy);
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  if (std::error_code EC = MOrErr.getError())
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    return EC;
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  std::unique_ptr<Module> &M = *MOrErr;
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  std::string TripleStr = M->getTargetTriple();
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  if (TripleStr.empty())
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    TripleStr = sys::getDefaultTargetTriple();
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  llvm::Triple Triple(TripleStr);
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  // find machine architecture for this module
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  std::string errMsg;
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  const Target *march = TargetRegistry::lookupTarget(TripleStr, errMsg);
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  if (!march)
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    return make_error_code(object::object_error::arch_not_found);
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  // construct LTOModule, hand over ownership of module and target
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  SubtargetFeatures Features;
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  Features.getDefaultSubtargetFeatures(Triple);
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  std::string FeatureStr = Features.getString();
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  // Set a default CPU for Darwin triples.
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  std::string CPU;
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  if (Triple.isOSDarwin()) {
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    if (Triple.getArch() == llvm::Triple::x86_64)
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      CPU = "core2";
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    else if (Triple.getArch() == llvm::Triple::x86)
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      CPU = "yonah";
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    else if (Triple.isArm64e())
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      CPU = "apple-a12";
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    else if (Triple.getArch() == llvm::Triple::aarch64 ||
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             Triple.getArch() == llvm::Triple::aarch64_32)
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      CPU = "cyclone";
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  }
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  TargetMachine *target =
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      march->createTargetMachine(TripleStr, CPU, FeatureStr, options, None);
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  std::unique_ptr<LTOModule> Ret(new LTOModule(std::move(M), Buffer, target));
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  Ret->parseSymbols();
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  Ret->parseMetadata();
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  return std::move(Ret);
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}
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/// Create a MemoryBuffer from a memory range with an optional name.
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std::unique_ptr<MemoryBuffer>
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LTOModule::makeBuffer(const void *mem, size_t length, StringRef name) {
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  const char *startPtr = (const char*)mem;
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  return MemoryBuffer::getMemBuffer(StringRef(startPtr, length), name, false);
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}
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/// objcClassNameFromExpression - Get string that the data pointer points to.
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bool
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LTOModule::objcClassNameFromExpression(const Constant *c, std::string &name) {
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  if (const ConstantExpr *ce = dyn_cast<ConstantExpr>(c)) {
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    Constant *op = ce->getOperand(0);
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    if (GlobalVariable *gvn = dyn_cast<GlobalVariable>(op)) {
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      Constant *cn = gvn->getInitializer();
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      if (ConstantDataArray *ca = dyn_cast<ConstantDataArray>(cn)) {
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        if (ca->isCString()) {
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          name = (".objc_class_name_" + ca->getAsCString()).str();
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          return true;
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        }
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      }
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    }
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  }
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  return false;
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}
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/// addObjCClass - Parse i386/ppc ObjC class data structure.
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void LTOModule::addObjCClass(const GlobalVariable *clgv) {
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  const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer());
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  if (!c) return;
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  // second slot in __OBJC,__class is pointer to superclass name
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  std::string superclassName;
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  if (objcClassNameFromExpression(c->getOperand(1), superclassName)) {
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    auto IterBool =
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        _undefines.insert(std::make_pair(superclassName, NameAndAttributes()));
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    if (IterBool.second) {
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      NameAndAttributes &info = IterBool.first->second;
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      info.name = IterBool.first->first();
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      info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
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      info.isFunction = false;
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      info.symbol = clgv;
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    }
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  }
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  // third slot in __OBJC,__class is pointer to class name
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  std::string className;
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  if (objcClassNameFromExpression(c->getOperand(2), className)) {
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    auto Iter = _defines.insert(className).first;
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    NameAndAttributes info;
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    info.name = Iter->first();
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    info.attributes = LTO_SYMBOL_PERMISSIONS_DATA |
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      LTO_SYMBOL_DEFINITION_REGULAR | LTO_SYMBOL_SCOPE_DEFAULT;
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    info.isFunction = false;
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    info.symbol = clgv;
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    _symbols.push_back(info);
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  }
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}
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/// addObjCCategory - Parse i386/ppc ObjC category data structure.
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void LTOModule::addObjCCategory(const GlobalVariable *clgv) {
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  const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer());
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  if (!c) return;
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  // second slot in __OBJC,__category is pointer to target class name
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  std::string targetclassName;
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  if (!objcClassNameFromExpression(c->getOperand(1), targetclassName))
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    return;
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  auto IterBool =
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      _undefines.insert(std::make_pair(targetclassName, NameAndAttributes()));
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  if (!IterBool.second)
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    return;
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  NameAndAttributes &info = IterBool.first->second;
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  info.name = IterBool.first->first();
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  info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
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  info.isFunction = false;
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  info.symbol = clgv;
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}
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/// addObjCClassRef - Parse i386/ppc ObjC class list data structure.
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void LTOModule::addObjCClassRef(const GlobalVariable *clgv) {
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  std::string targetclassName;
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  if (!objcClassNameFromExpression(clgv->getInitializer(), targetclassName))
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    return;
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  auto IterBool =
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      _undefines.insert(std::make_pair(targetclassName, NameAndAttributes()));
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  if (!IterBool.second)
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    return;
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  NameAndAttributes &info = IterBool.first->second;
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  info.name = IterBool.first->first();
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  info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
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  info.isFunction = false;
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  info.symbol = clgv;
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}
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void LTOModule::addDefinedDataSymbol(ModuleSymbolTable::Symbol Sym) {
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  SmallString<64> Buffer;
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  {
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    raw_svector_ostream OS(Buffer);
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    SymTab.printSymbolName(OS, Sym);
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    Buffer.c_str();
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  }
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  const GlobalValue *V = Sym.get<GlobalValue *>();
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  addDefinedDataSymbol(Buffer, V);
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}
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void LTOModule::addDefinedDataSymbol(StringRef Name, const GlobalValue *v) {
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  // Add to list of defined symbols.
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  addDefinedSymbol(Name, v, false);
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  if (!v->hasSection() /* || !isTargetDarwin */)
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    return;
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  // Special case i386/ppc ObjC data structures in magic sections:
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  // The issue is that the old ObjC object format did some strange
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  // contortions to avoid real linker symbols.  For instance, the
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  // ObjC class data structure is allocated statically in the executable
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  // that defines that class.  That data structures contains a pointer to
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  // its superclass.  But instead of just initializing that part of the
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  // struct to the address of its superclass, and letting the static and
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  // dynamic linkers do the rest, the runtime works by having that field
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  // instead point to a C-string that is the name of the superclass.
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  // At runtime the objc initialization updates that pointer and sets
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  // it to point to the actual super class.  As far as the linker
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  // knows it is just a pointer to a string.  But then someone wanted the
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  // linker to issue errors at build time if the superclass was not found.
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  // So they figured out a way in mach-o object format to use an absolute
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  // symbols (.objc_class_name_Foo = 0) and a floating reference
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  // (.reference .objc_class_name_Bar) to cause the linker into erroring when
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  // a class was missing.
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  // The following synthesizes the implicit .objc_* symbols for the linker
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  // from the ObjC data structures generated by the front end.
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  // special case if this data blob is an ObjC class definition
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  if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(v)) {
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    StringRef Section = GV->getSection();
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    if (Section.startswith("__OBJC,__class,")) {
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      addObjCClass(GV);
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    }
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    // special case if this data blob is an ObjC category definition
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    else if (Section.startswith("__OBJC,__category,")) {
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      addObjCCategory(GV);
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    }
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    // special case if this data blob is the list of referenced classes
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    else if (Section.startswith("__OBJC,__cls_refs,")) {
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      addObjCClassRef(GV);
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    }
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  }
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}
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void LTOModule::addDefinedFunctionSymbol(ModuleSymbolTable::Symbol Sym) {
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  SmallString<64> Buffer;
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  {
 | 
						|
    raw_svector_ostream OS(Buffer);
 | 
						|
    SymTab.printSymbolName(OS, Sym);
 | 
						|
    Buffer.c_str();
 | 
						|
  }
 | 
						|
 | 
						|
  const Function *F = cast<Function>(Sym.get<GlobalValue *>());
 | 
						|
  addDefinedFunctionSymbol(Buffer, F);
 | 
						|
}
 | 
						|
 | 
						|
void LTOModule::addDefinedFunctionSymbol(StringRef Name, const Function *F) {
 | 
						|
  // add to list of defined symbols
 | 
						|
  addDefinedSymbol(Name, F, true);
 | 
						|
}
 | 
						|
 | 
						|
void LTOModule::addDefinedSymbol(StringRef Name, const GlobalValue *def,
 | 
						|
                                 bool isFunction) {
 | 
						|
  const GlobalObject *go = dyn_cast<GlobalObject>(def);
 | 
						|
  uint32_t attr = go ? Log2(go->getAlign().valueOrOne()) : 0;
 | 
						|
 | 
						|
  // set permissions part
 | 
						|
  if (isFunction) {
 | 
						|
    attr |= LTO_SYMBOL_PERMISSIONS_CODE;
 | 
						|
  } else {
 | 
						|
    const GlobalVariable *gv = dyn_cast<GlobalVariable>(def);
 | 
						|
    if (gv && gv->isConstant())
 | 
						|
      attr |= LTO_SYMBOL_PERMISSIONS_RODATA;
 | 
						|
    else
 | 
						|
      attr |= LTO_SYMBOL_PERMISSIONS_DATA;
 | 
						|
  }
 | 
						|
 | 
						|
  // set definition part
 | 
						|
  if (def->hasWeakLinkage() || def->hasLinkOnceLinkage())
 | 
						|
    attr |= LTO_SYMBOL_DEFINITION_WEAK;
 | 
						|
  else if (def->hasCommonLinkage())
 | 
						|
    attr |= LTO_SYMBOL_DEFINITION_TENTATIVE;
 | 
						|
  else
 | 
						|
    attr |= LTO_SYMBOL_DEFINITION_REGULAR;
 | 
						|
 | 
						|
  // set scope part
 | 
						|
  if (def->hasLocalLinkage())
 | 
						|
    // Ignore visibility if linkage is local.
 | 
						|
    attr |= LTO_SYMBOL_SCOPE_INTERNAL;
 | 
						|
  else if (def->hasHiddenVisibility())
 | 
						|
    attr |= LTO_SYMBOL_SCOPE_HIDDEN;
 | 
						|
  else if (def->hasProtectedVisibility())
 | 
						|
    attr |= LTO_SYMBOL_SCOPE_PROTECTED;
 | 
						|
  else if (def->canBeOmittedFromSymbolTable())
 | 
						|
    attr |= LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN;
 | 
						|
  else
 | 
						|
    attr |= LTO_SYMBOL_SCOPE_DEFAULT;
 | 
						|
 | 
						|
  if (def->hasComdat())
 | 
						|
    attr |= LTO_SYMBOL_COMDAT;
 | 
						|
 | 
						|
  if (isa<GlobalAlias>(def))
 | 
						|
    attr |= LTO_SYMBOL_ALIAS;
 | 
						|
 | 
						|
  auto Iter = _defines.insert(Name).first;
 | 
						|
 | 
						|
  // fill information structure
 | 
						|
  NameAndAttributes info;
 | 
						|
  StringRef NameRef = Iter->first();
 | 
						|
  info.name = NameRef;
 | 
						|
  assert(NameRef.data()[NameRef.size()] == '\0');
 | 
						|
  info.attributes = attr;
 | 
						|
  info.isFunction = isFunction;
 | 
						|
  info.symbol = def;
 | 
						|
 | 
						|
  // add to table of symbols
 | 
						|
  _symbols.push_back(info);
 | 
						|
}
 | 
						|
 | 
						|
/// addAsmGlobalSymbol - Add a global symbol from module-level ASM to the
 | 
						|
/// defined list.
 | 
						|
void LTOModule::addAsmGlobalSymbol(StringRef name,
 | 
						|
                                   lto_symbol_attributes scope) {
 | 
						|
  auto IterBool = _defines.insert(name);
 | 
						|
 | 
						|
  // only add new define if not already defined
 | 
						|
  if (!IterBool.second)
 | 
						|
    return;
 | 
						|
 | 
						|
  NameAndAttributes &info = _undefines[IterBool.first->first()];
 | 
						|
 | 
						|
  if (info.symbol == nullptr) {
 | 
						|
    // FIXME: This is trying to take care of module ASM like this:
 | 
						|
    //
 | 
						|
    //   module asm ".zerofill __FOO, __foo, _bar_baz_qux, 0"
 | 
						|
    //
 | 
						|
    // but is gross and its mother dresses it funny. Have the ASM parser give us
 | 
						|
    // more details for this type of situation so that we're not guessing so
 | 
						|
    // much.
 | 
						|
 | 
						|
    // fill information structure
 | 
						|
    info.name = IterBool.first->first();
 | 
						|
    info.attributes =
 | 
						|
      LTO_SYMBOL_PERMISSIONS_DATA | LTO_SYMBOL_DEFINITION_REGULAR | scope;
 | 
						|
    info.isFunction = false;
 | 
						|
    info.symbol = nullptr;
 | 
						|
 | 
						|
    // add to table of symbols
 | 
						|
    _symbols.push_back(info);
 | 
						|
    return;
 | 
						|
  }
 | 
						|
 | 
						|
  if (info.isFunction)
 | 
						|
    addDefinedFunctionSymbol(info.name, cast<Function>(info.symbol));
 | 
						|
  else
 | 
						|
    addDefinedDataSymbol(info.name, info.symbol);
 | 
						|
 | 
						|
  _symbols.back().attributes &= ~LTO_SYMBOL_SCOPE_MASK;
 | 
						|
  _symbols.back().attributes |= scope;
 | 
						|
}
 | 
						|
 | 
						|
/// addAsmGlobalSymbolUndef - Add a global symbol from module-level ASM to the
 | 
						|
/// undefined list.
 | 
						|
void LTOModule::addAsmGlobalSymbolUndef(StringRef name) {
 | 
						|
  auto IterBool = _undefines.insert(std::make_pair(name, NameAndAttributes()));
 | 
						|
 | 
						|
  _asm_undefines.push_back(IterBool.first->first());
 | 
						|
 | 
						|
  // we already have the symbol
 | 
						|
  if (!IterBool.second)
 | 
						|
    return;
 | 
						|
 | 
						|
  uint32_t attr = LTO_SYMBOL_DEFINITION_UNDEFINED;
 | 
						|
  attr |= LTO_SYMBOL_SCOPE_DEFAULT;
 | 
						|
  NameAndAttributes &info = IterBool.first->second;
 | 
						|
  info.name = IterBool.first->first();
 | 
						|
  info.attributes = attr;
 | 
						|
  info.isFunction = false;
 | 
						|
  info.symbol = nullptr;
 | 
						|
}
 | 
						|
 | 
						|
/// Add a symbol which isn't defined just yet to a list to be resolved later.
 | 
						|
void LTOModule::addPotentialUndefinedSymbol(ModuleSymbolTable::Symbol Sym,
 | 
						|
                                            bool isFunc) {
 | 
						|
  SmallString<64> name;
 | 
						|
  {
 | 
						|
    raw_svector_ostream OS(name);
 | 
						|
    SymTab.printSymbolName(OS, Sym);
 | 
						|
    name.c_str();
 | 
						|
  }
 | 
						|
 | 
						|
  auto IterBool =
 | 
						|
      _undefines.insert(std::make_pair(name.str(), NameAndAttributes()));
 | 
						|
 | 
						|
  // we already have the symbol
 | 
						|
  if (!IterBool.second)
 | 
						|
    return;
 | 
						|
 | 
						|
  NameAndAttributes &info = IterBool.first->second;
 | 
						|
 | 
						|
  info.name = IterBool.first->first();
 | 
						|
 | 
						|
  const GlobalValue *decl = Sym.dyn_cast<GlobalValue *>();
 | 
						|
 | 
						|
  if (decl->hasExternalWeakLinkage())
 | 
						|
    info.attributes = LTO_SYMBOL_DEFINITION_WEAKUNDEF;
 | 
						|
  else
 | 
						|
    info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED;
 | 
						|
 | 
						|
  info.isFunction = isFunc;
 | 
						|
  info.symbol = decl;
 | 
						|
}
 | 
						|
 | 
						|
void LTOModule::parseSymbols() {
 | 
						|
  for (auto Sym : SymTab.symbols()) {
 | 
						|
    auto *GV = Sym.dyn_cast<GlobalValue *>();
 | 
						|
    uint32_t Flags = SymTab.getSymbolFlags(Sym);
 | 
						|
    if (Flags & object::BasicSymbolRef::SF_FormatSpecific)
 | 
						|
      continue;
 | 
						|
 | 
						|
    bool IsUndefined = Flags & object::BasicSymbolRef::SF_Undefined;
 | 
						|
 | 
						|
    if (!GV) {
 | 
						|
      SmallString<64> Buffer;
 | 
						|
      {
 | 
						|
        raw_svector_ostream OS(Buffer);
 | 
						|
        SymTab.printSymbolName(OS, Sym);
 | 
						|
        Buffer.c_str();
 | 
						|
      }
 | 
						|
      StringRef Name = Buffer;
 | 
						|
 | 
						|
      if (IsUndefined)
 | 
						|
        addAsmGlobalSymbolUndef(Name);
 | 
						|
      else if (Flags & object::BasicSymbolRef::SF_Global)
 | 
						|
        addAsmGlobalSymbol(Name, LTO_SYMBOL_SCOPE_DEFAULT);
 | 
						|
      else
 | 
						|
        addAsmGlobalSymbol(Name, LTO_SYMBOL_SCOPE_INTERNAL);
 | 
						|
      continue;
 | 
						|
    }
 | 
						|
 | 
						|
    auto *F = dyn_cast<Function>(GV);
 | 
						|
    if (IsUndefined) {
 | 
						|
      addPotentialUndefinedSymbol(Sym, F != nullptr);
 | 
						|
      continue;
 | 
						|
    }
 | 
						|
 | 
						|
    if (F) {
 | 
						|
      addDefinedFunctionSymbol(Sym);
 | 
						|
      continue;
 | 
						|
    }
 | 
						|
 | 
						|
    if (isa<GlobalVariable>(GV)) {
 | 
						|
      addDefinedDataSymbol(Sym);
 | 
						|
      continue;
 | 
						|
    }
 | 
						|
 | 
						|
    assert(isa<GlobalAlias>(GV));
 | 
						|
    addDefinedDataSymbol(Sym);
 | 
						|
  }
 | 
						|
 | 
						|
  // make symbols for all undefines
 | 
						|
  for (StringMap<NameAndAttributes>::iterator u =_undefines.begin(),
 | 
						|
         e = _undefines.end(); u != e; ++u) {
 | 
						|
    // If this symbol also has a definition, then don't make an undefine because
 | 
						|
    // it is a tentative definition.
 | 
						|
    if (_defines.count(u->getKey())) continue;
 | 
						|
    NameAndAttributes info = u->getValue();
 | 
						|
    _symbols.push_back(info);
 | 
						|
  }
 | 
						|
}
 | 
						|
 | 
						|
/// parseMetadata - Parse metadata from the module
 | 
						|
void LTOModule::parseMetadata() {
 | 
						|
  raw_string_ostream OS(LinkerOpts);
 | 
						|
 | 
						|
  // Linker Options
 | 
						|
  if (NamedMDNode *LinkerOptions =
 | 
						|
          getModule().getNamedMetadata("llvm.linker.options")) {
 | 
						|
    for (unsigned i = 0, e = LinkerOptions->getNumOperands(); i != e; ++i) {
 | 
						|
      MDNode *MDOptions = LinkerOptions->getOperand(i);
 | 
						|
      for (unsigned ii = 0, ie = MDOptions->getNumOperands(); ii != ie; ++ii) {
 | 
						|
        MDString *MDOption = cast<MDString>(MDOptions->getOperand(ii));
 | 
						|
        OS << " " << MDOption->getString();
 | 
						|
      }
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  // Globals - we only need to do this for COFF.
 | 
						|
  const Triple TT(_target->getTargetTriple());
 | 
						|
  if (!TT.isOSBinFormatCOFF())
 | 
						|
    return;
 | 
						|
  Mangler M;
 | 
						|
  for (const NameAndAttributes &Sym : _symbols) {
 | 
						|
    if (!Sym.symbol)
 | 
						|
      continue;
 | 
						|
    emitLinkerFlagsForGlobalCOFF(OS, Sym.symbol, TT, M);
 | 
						|
  }
 | 
						|
}
 | 
						|
 | 
						|
lto::InputFile *LTOModule::createInputFile(const void *buffer,
 | 
						|
                                           size_t buffer_size, const char *path,
 | 
						|
                                           std::string &outErr) {
 | 
						|
  StringRef Data((const char *)buffer, buffer_size);
 | 
						|
  MemoryBufferRef BufferRef(Data, path);
 | 
						|
 | 
						|
  Expected<std::unique_ptr<lto::InputFile>> ObjOrErr =
 | 
						|
      lto::InputFile::create(BufferRef);
 | 
						|
 | 
						|
  if (ObjOrErr)
 | 
						|
    return ObjOrErr->release();
 | 
						|
 | 
						|
  outErr = std::string(path) +
 | 
						|
           ": Could not read LTO input file: " + toString(ObjOrErr.takeError());
 | 
						|
  return nullptr;
 | 
						|
}
 | 
						|
 | 
						|
size_t LTOModule::getDependentLibraryCount(lto::InputFile *input) {
 | 
						|
  return input->getDependentLibraries().size();
 | 
						|
}
 | 
						|
 | 
						|
const char *LTOModule::getDependentLibrary(lto::InputFile *input, size_t index,
 | 
						|
                                           size_t *size) {
 | 
						|
  StringRef S = input->getDependentLibraries()[index];
 | 
						|
  *size = S.size();
 | 
						|
  return S.data();
 | 
						|
}
 | 
						|
 | 
						|
Expected<uint32_t> LTOModule::getMachOCPUType() const {
 | 
						|
  return MachO::getCPUType(Triple(Mod->getTargetTriple()));
 | 
						|
}
 | 
						|
 | 
						|
Expected<uint32_t> LTOModule::getMachOCPUSubType() const {
 | 
						|
  return MachO::getCPUSubType(Triple(Mod->getTargetTriple()));
 | 
						|
}
 | 
						|
 | 
						|
bool LTOModule::hasCtorDtor() const {
 | 
						|
  for (auto Sym : SymTab.symbols()) {
 | 
						|
    if (auto *GV = Sym.dyn_cast<GlobalValue *>()) {
 | 
						|
      StringRef Name = GV->getName();
 | 
						|
      if (Name.consume_front("llvm.global_")) {
 | 
						|
        if (Name.equals("ctors") || Name.equals("dtors"))
 | 
						|
          return true;
 | 
						|
      }
 | 
						|
    }
 | 
						|
  }
 | 
						|
  return false;
 | 
						|
}
 |