C++ GlobalVariable::setSection方法代码示例

void LTOCodeGenerator::applyScopeRestrictions() {
  if (ScopeRestrictionsDone)
    return;
  Module *mergedModule = Linker.getModule();

  // Start off with a verification pass.
  PassManager passes;
  passes.add(createVerifierPass());

  // mark which symbols can not be internalized
  Mangler Mangler(TargetMach);
  std::vector<const char*> MustPreserveList;
  SmallPtrSet<GlobalValue*, 8> AsmUsed;
  std::vector<StringRef> Libcalls;
  TargetLibraryInfo TLI(Triple(TargetMach->getTargetTriple()));
  accumulateAndSortLibcalls(Libcalls, TLI, TargetMach->getTargetLowering());

  for (Module::iterator f = mergedModule->begin(),
         e = mergedModule->end(); f != e; ++f)
    applyRestriction(*f, Libcalls, MustPreserveList, AsmUsed, Mangler);
  for (Module::global_iterator v = mergedModule->global_begin(),
         e = mergedModule->global_end(); v !=  e; ++v)
    applyRestriction(*v, Libcalls, MustPreserveList, AsmUsed, Mangler);
  for (Module::alias_iterator a = mergedModule->alias_begin(),
         e = mergedModule->alias_end(); a != e; ++a)
    applyRestriction(*a, Libcalls, MustPreserveList, AsmUsed, Mangler);

  GlobalVariable *LLVMCompilerUsed =
    mergedModule->getGlobalVariable("llvm.compiler.used");
  findUsedValues(LLVMCompilerUsed, AsmUsed);
  if (LLVMCompilerUsed)
    LLVMCompilerUsed->eraseFromParent();

  if (!AsmUsed.empty()) {
    llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(Context);
    std::vector<Constant*> asmUsed2;
    for (SmallPtrSet<GlobalValue*, 16>::const_iterator i = AsmUsed.begin(),
           e = AsmUsed.end(); i !=e; ++i) {
      GlobalValue *GV = *i;
      Constant *c = ConstantExpr::getBitCast(GV, i8PTy);
      asmUsed2.push_back(c);
    }

    llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, asmUsed2.size());
    LLVMCompilerUsed =
      new llvm::GlobalVariable(*mergedModule, ATy, false,
                               llvm::GlobalValue::AppendingLinkage,
                               llvm::ConstantArray::get(ATy, asmUsed2),
                               "llvm.compiler.used");

    LLVMCompilerUsed->setSection("llvm.metadata");
  }

  passes.add(createInternalizePass(MustPreserveList));

  // apply scope restrictions
  passes.run(*mergedModule);

  ScopeRestrictionsDone = true;
}

void InstrProfiling::lowerCoverageData(GlobalVariable *CoverageData) {
  CoverageData->setSection(getCoverageSection());
  CoverageData->setAlignment(8);

  Constant *Init = CoverageData->getInitializer();
  // We're expecting { i32, i32, i32, i32, [n x { i8*, i32, i32 }], [m x i8] }
  // for some C. If not, the frontend's given us something broken.
  assert(Init->getNumOperands() == 6 && "bad number of fields in coverage map");
  assert(isa<ConstantArray>(Init->getAggregateElement(4)) &&
         "invalid function list in coverage map");
  ConstantArray *Records = cast<ConstantArray>(Init->getAggregateElement(4));
  for (unsigned I = 0, E = Records->getNumOperands(); I < E; ++I) {
    Constant *Record = Records->getOperand(I);
    Value *V = const_cast<Value *>(Record->getOperand(0))->stripPointerCasts();

    assert(isa<GlobalVariable>(V) && "Missing reference to function name");
    GlobalVariable *Name = cast<GlobalVariable>(V);

    // If we have region counters for this name, we've already handled it.
    auto It = RegionCounters.find(Name);
    if (It != RegionCounters.end())
      continue;

    // Move the name variable to the right section.
    Name->setSection(getNameSection());
    Name->setAlignment(1);
  }
}

void InstrProfiling::emitUses() {
  if (UsedVars.empty())
    return;

  GlobalVariable *LLVMUsed = M->getGlobalVariable("llvm.used");
  std::vector<Constant *> MergedVars;
  if (LLVMUsed) {
    // Collect the existing members of llvm.used.
    ConstantArray *Inits = cast<ConstantArray>(LLVMUsed->getInitializer());
    for (unsigned I = 0, E = Inits->getNumOperands(); I != E; ++I)
      MergedVars.push_back(Inits->getOperand(I));
    LLVMUsed->eraseFromParent();
  }

  Type *i8PTy = Type::getInt8PtrTy(M->getContext());
  // Add uses for our data.
  for (auto *Value : UsedVars)
    MergedVars.push_back(
        ConstantExpr::getBitCast(cast<Constant>(Value), i8PTy));

  // Recreate llvm.used.
  ArrayType *ATy = ArrayType::get(i8PTy, MergedVars.size());
  LLVMUsed =
      new GlobalVariable(*M, ATy, false, GlobalValue::AppendingLinkage,
                         ConstantArray::get(ATy, MergedVars), "llvm.used");

  LLVMUsed->setSection("llvm.metadata");
}

void LTOCodeGenerator::applyScopeRestrictions() {
  if (_scopeRestrictionsDone) return;
  Module *mergedModule = _linker.getModule();

  // Start off with a verification pass.
  PassManager passes;
  passes.add(createVerifierPass());

  // mark which symbols can not be internalized
  MCContext Context(*_target->getMCAsmInfo(), *_target->getRegisterInfo(),NULL);
  Mangler mangler(Context, *_target->getTargetData());
  std::vector<const char*> mustPreserveList;
  SmallPtrSet<GlobalValue*, 8> asmUsed;

  for (Module::iterator f = mergedModule->begin(),
         e = mergedModule->end(); f != e; ++f)
    applyRestriction(*f, mustPreserveList, asmUsed, mangler);
  for (Module::global_iterator v = mergedModule->global_begin(),
         e = mergedModule->global_end(); v !=  e; ++v)
    applyRestriction(*v, mustPreserveList, asmUsed, mangler);
  for (Module::alias_iterator a = mergedModule->alias_begin(),
         e = mergedModule->alias_end(); a != e; ++a)
    applyRestriction(*a, mustPreserveList, asmUsed, mangler);

  GlobalVariable *LLVMCompilerUsed =
    mergedModule->getGlobalVariable("llvm.compiler.used");
  findUsedValues(LLVMCompilerUsed, asmUsed);
  if (LLVMCompilerUsed)
    LLVMCompilerUsed->eraseFromParent();

  llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(_context);
  std::vector<Constant*> asmUsed2;
  for (SmallPtrSet<GlobalValue*, 16>::const_iterator i = asmUsed.begin(),
         e = asmUsed.end(); i !=e; ++i) {
    GlobalValue *GV = *i;
    Constant *c = ConstantExpr::getBitCast(GV, i8PTy);
    asmUsed2.push_back(c);
  }

  llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, asmUsed2.size());
  LLVMCompilerUsed =
    new llvm::GlobalVariable(*mergedModule, ATy, false,
                             llvm::GlobalValue::AppendingLinkage,
                             llvm::ConstantArray::get(ATy, asmUsed2),
                             "llvm.compiler.used");

  LLVMCompilerUsed->setSection("llvm.metadata");

  // Add prerequisite passes needed by SAFECode
  PassManagerBuilder().populateLTOPassManager(passes, /*Internalize=*/ false,
                                              !DisableInline);

  passes.add(createInternalizePass(mustPreserveList));

  // apply scope restrictions
  passes.run(*mergedModule);

  _scopeRestrictionsDone = true;
}

void LTOCodeGenerator::applyScopeRestrictions() {
  if (ScopeRestrictionsDone || !ShouldInternalize)
    return;

  // Start off with a verification pass.
  legacy::PassManager passes;
  passes.add(createVerifierPass());

  // mark which symbols can not be internalized
  Mangler Mangler;
  std::vector<const char*> MustPreserveList;
  SmallPtrSet<GlobalValue*, 8> AsmUsed;
  std::vector<StringRef> Libcalls;
  TargetLibraryInfoImpl TLII(Triple(TargetMach->getTargetTriple()));
  TargetLibraryInfo TLI(TLII);

  accumulateAndSortLibcalls(Libcalls, TLI, *MergedModule, *TargetMach);

  for (Function &f : *MergedModule)
    applyRestriction(f, Libcalls, MustPreserveList, AsmUsed, Mangler);
  for (GlobalVariable &v : MergedModule->globals())
    applyRestriction(v, Libcalls, MustPreserveList, AsmUsed, Mangler);
  for (GlobalAlias &a : MergedModule->aliases())
    applyRestriction(a, Libcalls, MustPreserveList, AsmUsed, Mangler);

  GlobalVariable *LLVMCompilerUsed =
    MergedModule->getGlobalVariable("llvm.compiler.used");
  findUsedValues(LLVMCompilerUsed, AsmUsed);
  if (LLVMCompilerUsed)
    LLVMCompilerUsed->eraseFromParent();

  if (!AsmUsed.empty()) {
    llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(Context);
    std::vector<Constant*> asmUsed2;
    for (auto *GV : AsmUsed) {
      Constant *c = ConstantExpr::getBitCast(GV, i8PTy);
      asmUsed2.push_back(c);
    }

    llvm::ArrayType *ATy = llvm::ArrayType::get(i8PTy, asmUsed2.size());
    LLVMCompilerUsed =
      new llvm::GlobalVariable(*MergedModule, ATy, false,
                               llvm::GlobalValue::AppendingLinkage,
                               llvm::ConstantArray::get(ATy, asmUsed2),
                               "llvm.compiler.used");

    LLVMCompilerUsed->setSection("llvm.metadata");
  }

  passes.add(createInternalizePass(MustPreserveList));

  // apply scope restrictions
  passes.run(*MergedModule);

  ScopeRestrictionsDone = true;
}

bool SancusModuleCreator::handleData(GlobalVariable& gv)
{
    SancusModuleInfo info = getSancusModuleInfo(&gv);
    if (!info.isInSm)
        return false;

    if (gv.hasCommonLinkage())
        gv.setLinkage(GlobalValue::WeakAnyLinkage);

    gv.setSection(info.getDataSection());
    return true;
}

void SancusModuleCreator::createFunctionTable(Module& m)
{
    LLVMContext& ctx = m.getContext();

    // struct SmFunctionInfo
    // {
    //     void* address;
    //     unsigned arg_length;
    //     unsigned ret_regs;
    // };
    Type* funcInfoFields[] = {voidPtrTy, wordTy, wordTy};

    StructType* funcInfoTy = StructType::get(ctx, funcInfoFields,
                                             /*isPacked=*/true);

    // create a global SM function table for every SM and initialize it
    // initializers for the funcs[] array.
    // map from section name to initializer
    std::map<std::string, std::vector<Constant*>> funcsEls;
    for (Function* f : entries)
    {
        SancusModuleInfo info = getSancusModuleInfo(f);
        assert(info.isEntry && "Asking function table for non-entry");

        // initializer for the SmFunctionInfo struct
        FunctionCcInfo ccInfo(f);
        Constant* funcFields[] = {ConstantExpr::getBitCast(f, voidPtrTy),
                                  ConstantInt::get(wordTy, ccInfo.argsLength),
                                  ConstantInt::get(wordTy, ccInfo.retRegsUsage)};
        funcsEls[info.getTableSection()]
            .push_back(ConstantStruct::get(funcInfoTy, funcFields));
    }

    for (const auto& it : funcsEls)
    {
        // struct SmFunctionInfo funcs[];
        ArrayType* funcsTy = ArrayType::get(funcInfoTy, it.second.size());
        Constant* funcsInit = ConstantArray::get(funcsTy, it.second);

        GlobalVariable* table =
            new GlobalVariable(m, funcsTy, /*isConstant=*/true,
                               GlobalVariable::InternalLinkage, funcsInit);
        table->setSection(it.first);
        table->setAlignment(2);
    }
}

// Convert string to global value. Use existing global if possible.
Constant* ConvertMetadataStringToGV(const char *str) {
  
  Constant *Init = ConstantArray::get(std::string(str));

  // Use cached string if it exists.
  static std::map<Constant*, GlobalVariable*> StringCSTCache;
  GlobalVariable *&Slot = StringCSTCache[Init];
  if (Slot) return Slot;
  
  // Create a new string global.
  GlobalVariable *GV = new GlobalVariable(Init->getType(), true,
                                          GlobalVariable::InternalLinkage,
                                          Init, ".str", TheModule);
  GV->setSection("llvm.metadata");
  Slot = GV;
  return GV;
  
}

GlobalVariable *
InstrProfiling::getOrCreateRegionCounters(InstrProfIncrementInst *Inc) {
  GlobalVariable *Name = Inc->getName();
  auto It = RegionCounters.find(Name);
  if (It != RegionCounters.end())
    return It->second;

  // Move the name variable to the right section. Place them in a COMDAT group
  // if the associated function is a COMDAT. This will make sure that
  // only one copy of counters of the COMDAT function will be emitted after
  // linking.
  Function *Fn = Inc->getParent()->getParent();
  Comdat *ProfileVarsComdat = nullptr;
  if (Fn->hasComdat())
    ProfileVarsComdat = M->getOrInsertComdat(StringRef(getVarName(Inc, "vars")));
  Name->setSection(getNameSection());
  Name->setAlignment(1);
  Name->setComdat(ProfileVarsComdat);

  uint64_t NumCounters = Inc->getNumCounters()->getZExtValue();
  LLVMContext &Ctx = M->getContext();
  ArrayType *CounterTy = ArrayType::get(Type::getInt64Ty(Ctx), NumCounters);

  // Create the counters variable.
  auto *Counters = new GlobalVariable(*M, CounterTy, false, Name->getLinkage(),
                                      Constant::getNullValue(CounterTy),
                                      getVarName(Inc, "counters"));
  Counters->setVisibility(Name->getVisibility());
  Counters->setSection(getCountersSection());
  Counters->setAlignment(8);
  Counters->setComdat(ProfileVarsComdat);

  RegionCounters[Inc->getName()] = Counters;

  // Create data variable.
  auto *NameArrayTy = Name->getType()->getPointerElementType();
  auto *Int32Ty = Type::getInt32Ty(Ctx);
  auto *Int64Ty = Type::getInt64Ty(Ctx);
  auto *Int8PtrTy = Type::getInt8PtrTy(Ctx);
  auto *Int64PtrTy = Type::getInt64PtrTy(Ctx);

  Type *DataTypes[] = {Int32Ty, Int32Ty, Int64Ty, Int8PtrTy, Int64PtrTy};
  auto *DataTy = StructType::get(Ctx, makeArrayRef(DataTypes));
  Constant *DataVals[] = {
      ConstantInt::get(Int32Ty, NameArrayTy->getArrayNumElements()),
      ConstantInt::get(Int32Ty, NumCounters),
      ConstantInt::get(Int64Ty, Inc->getHash()->getZExtValue()),
      ConstantExpr::getBitCast(Name, Int8PtrTy),
      ConstantExpr::getBitCast(Counters, Int64PtrTy)};
  auto *Data = new GlobalVariable(*M, DataTy, true, Name->getLinkage(),
                                  ConstantStruct::get(DataTy, DataVals),
                                  getVarName(Inc, "data"));
  Data->setVisibility(Name->getVisibility());
  Data->setSection(getDataSection());
  Data->setAlignment(8);
  Data->setComdat(ProfileVarsComdat);

  // Mark the data variable as used so that it isn't stripped out.
  UsedVars.push_back(Data);

  return Counters;
}

//.........这里部分代码省略.........
        report_fatal_error(I, "Metadata key argument is too large.");

    // Parse the 'fmt' parameter
    std::string fmt;
    if (!GetConstantStringInfo(CS.getArgument(argIdx++), fmt))
        report_fatal_error(I, "Metadata format must be a constant string.");
    if (fmt.size() != CS.arg_size() - 2)
        report_fatal_error(I, "Length of metadata format must match number of parameters");
    if (fmt.size() == 0)
        report_fatal_error(I, "Empty metadata values are not supported");

    /*
     * Parse every other parameter according to the format string
     */

    SmallVector<Constant*, 8> Members;
    unsigned align = 1;

    for (std::string::iterator FI = fmt.begin(), FE = fmt.end();
        FI != FE; ++FI, argIdx++) {
        Constant *Arg = dyn_cast<Constant>(CS.getArgument(argIdx));
        Constant *C;
        if (!Arg)
            report_fatal_error(I, "Metadata argument " + Twine(argIdx+1) + " is not constant");

        /*
         * First, non-integer types
         */

        switch (*FI) {
            case 's': {
                std::string str;
                if (!GetConstantStringInfo(Arg, str))
                    report_fatal_error(I, "Metadata formatter 's' requires a constant string");
                Members.push_back(ConstantArray::get(Ctx, str, false));
                continue;
            }
        }
        
        /*
         * Integer types
         */

        if (Arg->getType()->isPointerTy())
            Arg = ConstantExpr::getPointerCast(Arg, Type::getInt32Ty(Ctx));

        if (!Arg->getType()->isIntegerTy())
            report_fatal_error(I, "Metadata argument " + Twine(argIdx+1) +
                " can't be converted to an integer type.");

        switch (*FI) {

            case 'b':
                C = ConstantExpr::getIntegerCast(Arg, Type::getInt8Ty(Ctx), true);
                break;

            case 'B':
                C = ConstantExpr::getIntegerCast(Arg, Type::getInt8Ty(Ctx), false);
                break;

            case 'h':
                C = ConstantExpr::getIntegerCast(Arg, Type::getInt16Ty(Ctx), true);
                break;

            case 'H':
                C = ConstantExpr::getIntegerCast(Arg, Type::getInt16Ty(Ctx), false);
                break;

            case 'i':
                C = ConstantExpr::getIntegerCast(Arg, Type::getInt32Ty(Ctx), true);
                break;

            case 'I':
                C = ConstantExpr::getIntegerCast(Arg, Type::getInt32Ty(Ctx), false);
                break;

            default:
                report_fatal_error(I, "Unsupported format character '" + Twine(*FI) + "' in metadata");
        }

        align = std::max(align, TD->getABITypeAlignment(C->getType()));
        Members.push_back(C);
    }

    Constant *Struct = ConstantStruct::getAnon(Members);

    /*
     * Install this metadata item as a global variable in a special section
     */

    GlobalVariable *GV = new GlobalVariable(*M, Struct->getType(),
        true, GlobalValue::ExternalLinkage, Struct, "", 0, false);

    GV->setAlignment(align);
    GV->setName(SVMDecorations::META + Twine(key) + SVMDecorations::SEPARATOR);
    GV->setSection(".metadata");

    // Remove the original _SYS_lti_metadata() call
    I->eraseFromParent();
}

GlobalVariable *
InstrProfiling::getOrCreateRegionCounters(InstrProfIncrementInst *Inc) {
  GlobalVariable *NamePtr = Inc->getName();
  auto It = ProfileDataMap.find(NamePtr);
  PerFunctionProfileData PD;
  if (It != ProfileDataMap.end()) {
    if (It->second.RegionCounters)
      return It->second.RegionCounters;
    PD = It->second;
  }

  // Move the name variable to the right section. Place them in a COMDAT group
  // if the associated function is a COMDAT. This will make sure that
  // only one copy of counters of the COMDAT function will be emitted after
  // linking.
  Function *Fn = Inc->getParent()->getParent();
  Comdat *ProfileVarsComdat = nullptr;
  if (Fn->hasComdat())
    ProfileVarsComdat = getOrCreateProfileComdat(*M, Inc);
  NamePtr->setSection(getNameSection());
  NamePtr->setAlignment(1);
  NamePtr->setComdat(ProfileVarsComdat);

  uint64_t NumCounters = Inc->getNumCounters()->getZExtValue();
  LLVMContext &Ctx = M->getContext();
  ArrayType *CounterTy = ArrayType::get(Type::getInt64Ty(Ctx), NumCounters);

  // Create the counters variable.
  auto *CounterPtr =
      new GlobalVariable(*M, CounterTy, false, NamePtr->getLinkage(),
                         Constant::getNullValue(CounterTy),
                         getVarName(Inc, getInstrProfCountersVarPrefix()));
  CounterPtr->setVisibility(NamePtr->getVisibility());
  CounterPtr->setSection(getCountersSection());
  CounterPtr->setAlignment(8);
  CounterPtr->setComdat(ProfileVarsComdat);

  // Create data variable.
  auto *Int8PtrTy = Type::getInt8PtrTy(Ctx);
  auto *Int16Ty = Type::getInt16Ty(Ctx);
  auto *Int16ArrayTy = ArrayType::get(Int16Ty, IPVK_Last+1);
  Type *DataTypes[] = {
    #define INSTR_PROF_DATA(Type, LLVMType, Name, Init) LLVMType,
    #include "llvm/ProfileData/InstrProfData.inc"
  };
  auto *DataTy = StructType::get(Ctx, makeArrayRef(DataTypes));

  Constant *FunctionAddr = shouldRecordFunctionAddr(Fn) ?
                           ConstantExpr::getBitCast(Fn, Int8PtrTy) :
                           ConstantPointerNull::get(Int8PtrTy);

  Constant *Int16ArrayVals[IPVK_Last+1];
  for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
    Int16ArrayVals[Kind] = ConstantInt::get(Int16Ty, PD.NumValueSites[Kind]);

  Constant *DataVals[] = {
    #define INSTR_PROF_DATA(Type, LLVMType, Name, Init) Init,
    #include "llvm/ProfileData/InstrProfData.inc"
  };
  auto *Data = new GlobalVariable(*M, DataTy, false, NamePtr->getLinkage(),
                                  ConstantStruct::get(DataTy, DataVals),
                                  getVarName(Inc, getInstrProfDataVarPrefix()));
  Data->setVisibility(NamePtr->getVisibility());
  Data->setSection(getDataSection());
  Data->setAlignment(INSTR_PROF_DATA_ALIGNMENT);
  Data->setComdat(ProfileVarsComdat);

  PD.RegionCounters = CounterPtr;
  PD.DataVar = Data;
  ProfileDataMap[NamePtr] = PD;

  // Mark the data variable as used so that it isn't stripped out.
  UsedVars.push_back(Data);

  return CounterPtr;
}

/// emit_global_to_llvm - Emit the specified VAR_DECL or aggregate CONST_DECL to
/// LLVM as a global variable.  This function implements the end of
/// assemble_variable.
void emit_global_to_llvm(tree decl) {
  if (errorcount || sorrycount) return;

  // FIXME: Support alignment on globals: DECL_ALIGN.
  // FIXME: DECL_PRESERVE_P indicates the var is marked with attribute 'used'.

  // Global register variables don't turn into LLVM GlobalVariables.
  if (TREE_CODE(decl) == VAR_DECL && DECL_REGISTER(decl))
    return;

  timevar_push(TV_LLVM_GLOBALS);

  // Get or create the global variable now.
  GlobalVariable *GV = cast<GlobalVariable>(DECL_LLVM(decl));
  
  // Convert the initializer over.
  Constant *Init;
  if (DECL_INITIAL(decl) == 0 || DECL_INITIAL(decl) == error_mark_node) {
    // This global should be zero initialized.  Reconvert the type in case the
    // forward def of the global and the real def differ in type (e.g. declared
    // as 'int A[]', and defined as 'int A[100]').
    Init = Constant::getNullValue(ConvertType(TREE_TYPE(decl)));
  } else {
    assert((TREE_CONSTANT(DECL_INITIAL(decl)) || 
            TREE_CODE(DECL_INITIAL(decl)) == STRING_CST) &&
           "Global initializer should be constant!");
    
    // Temporarily set an initializer for the global, so we don't infinitely
    // recurse.  If we don't do this, we can hit cases where we see "oh a global
    // with an initializer hasn't been initialized yet, call emit_global_to_llvm
    // on it".  When constructing the initializer it might refer to itself.
    // this can happen for things like void *G = &G;
    //
    GV->setInitializer(UndefValue::get(GV->getType()->getElementType()));
    Init = TreeConstantToLLVM::Convert(DECL_INITIAL(decl));
  }

  // If we had a forward definition that has a type that disagrees with our
  // initializer, insert a cast now.  This sort of thing occurs when we have a
  // global union, and the LLVM type followed a union initializer that is
  // different from the union element used for the type.
  if (GV->getType()->getElementType() != Init->getType()) {
    GV->removeFromParent();
    GlobalVariable *NGV = new GlobalVariable(Init->getType(), GV->isConstant(),
                                             GlobalValue::ExternalLinkage, 0,
                                             GV->getName(), TheModule);
    GV->replaceAllUsesWith(ConstantExpr::getBitCast(NGV, GV->getType()));
    delete GV;
    SET_DECL_LLVM(decl, NGV);
    GV = NGV;
  }
 
  // Set the initializer.
  GV->setInitializer(Init);

  // Set thread local (TLS)
  if (TREE_CODE(decl) == VAR_DECL && DECL_THREAD_LOCAL(decl))
    GV->setThreadLocal(true);

  // Set the linkage.
  if (!TREE_PUBLIC(decl)) {
    GV->setLinkage(GlobalValue::InternalLinkage);
  } else if (DECL_WEAK(decl) || DECL_ONE_ONLY(decl) ||
             (DECL_COMMON(decl) &&  // DECL_COMMON is only meaningful if no init
              (!DECL_INITIAL(decl) || DECL_INITIAL(decl) == error_mark_node))) {
    // llvm-gcc also includes DECL_VIRTUAL_P here.
    GV->setLinkage(GlobalValue::WeakLinkage);
  } else if (DECL_COMDAT(decl)) {
    GV->setLinkage(GlobalValue::LinkOnceLinkage);
  }

#ifdef TARGET_ADJUST_LLVM_LINKAGE
  TARGET_ADJUST_LLVM_LINKAGE(GV,decl);
#endif /* TARGET_ADJUST_LLVM_LINKAGE */

  // Handle visibility style
  if (TREE_PUBLIC(decl)) {
    if (DECL_VISIBILITY(decl) == VISIBILITY_HIDDEN)
      GV->setVisibility(GlobalValue::HiddenVisibility);
    else if (DECL_VISIBILITY(decl) == VISIBILITY_PROTECTED)
      GV->setVisibility(GlobalValue::ProtectedVisibility);
  }

  // Set the section for the global.
  if (TREE_CODE(decl) == VAR_DECL || TREE_CODE(decl) == CONST_DECL) {
    if (DECL_SECTION_NAME(decl)) {
      GV->setSection(TREE_STRING_POINTER(DECL_SECTION_NAME(decl)));
#ifdef LLVM_IMPLICIT_TARGET_GLOBAL_VAR_SECTION
    } else if (const char *Section = 
                LLVM_IMPLICIT_TARGET_GLOBAL_VAR_SECTION(decl)) {
      GV->setSection(Section);
#endif
    }
    
    // Set the alignment for the global if one of the following condition is met
    // 1) DECL_ALIGN_UNIT does not match alignment as per ABI specification
    // 2) DECL_ALIGN is set by user.
//.........这里部分代码省略.........