| //===--- CGDeclCXX.cpp - Emit LLVM Code for C++ declarations --------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This contains code dealing with code generation of C++ declarations |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "CodeGenFunction.h" |
| #include "CGCXXABI.h" |
| #include "CGObjCRuntime.h" |
| #include "CGOpenMPRuntime.h" |
| #include "TargetInfo.h" |
| #include "clang/Basic/CodeGenOptions.h" |
| #include "llvm/ADT/StringExtras.h" |
| #include "llvm/IR/Intrinsics.h" |
| #include "llvm/IR/MDBuilder.h" |
| #include "llvm/Support/Path.h" |
| |
| using namespace clang; |
| using namespace CodeGen; |
| |
| static void EmitDeclInit(CodeGenFunction &CGF, const VarDecl &D, |
| ConstantAddress DeclPtr) { |
| assert( |
| (D.hasGlobalStorage() || |
| (D.hasLocalStorage() && CGF.getContext().getLangOpts().OpenCLCPlusPlus)) && |
| "VarDecl must have global or local (in the case of OpenCL) storage!"); |
| assert(!D.getType()->isReferenceType() && |
| "Should not call EmitDeclInit on a reference!"); |
| |
| QualType type = D.getType(); |
| LValue lv = CGF.MakeAddrLValue(DeclPtr, type); |
| |
| const Expr *Init = D.getInit(); |
| switch (CGF.getEvaluationKind(type)) { |
| case TEK_Scalar: { |
| CodeGenModule &CGM = CGF.CGM; |
| if (lv.isObjCStrong()) |
| CGM.getObjCRuntime().EmitObjCGlobalAssign(CGF, CGF.EmitScalarExpr(Init), |
| DeclPtr, D.getTLSKind()); |
| else if (lv.isObjCWeak()) |
| CGM.getObjCRuntime().EmitObjCWeakAssign(CGF, CGF.EmitScalarExpr(Init), |
| DeclPtr); |
| else |
| CGF.EmitScalarInit(Init, &D, lv, false); |
| return; |
| } |
| case TEK_Complex: |
| CGF.EmitComplexExprIntoLValue(Init, lv, /*isInit*/ true); |
| return; |
| case TEK_Aggregate: |
| CGF.EmitAggExpr(Init, AggValueSlot::forLValue(lv,AggValueSlot::IsDestructed, |
| AggValueSlot::DoesNotNeedGCBarriers, |
| AggValueSlot::IsNotAliased, |
| AggValueSlot::DoesNotOverlap)); |
| return; |
| } |
| llvm_unreachable("bad evaluation kind"); |
| } |
| |
| /// Emit code to cause the destruction of the given variable with |
| /// static storage duration. |
| static void EmitDeclDestroy(CodeGenFunction &CGF, const VarDecl &D, |
| ConstantAddress Addr) { |
| // Honor __attribute__((no_destroy)) and bail instead of attempting |
| // to emit a reference to a possibly nonexistent destructor, which |
| // in turn can cause a crash. This will result in a global constructor |
| // that isn't balanced out by a destructor call as intended by the |
| // attribute. This also checks for -fno-c++-static-destructors and |
| // bails even if the attribute is not present. |
| QualType::DestructionKind DtorKind = D.needsDestruction(CGF.getContext()); |
| |
| // FIXME: __attribute__((cleanup)) ? |
| |
| switch (DtorKind) { |
| case QualType::DK_none: |
| return; |
| |
| case QualType::DK_cxx_destructor: |
| break; |
| |
| case QualType::DK_objc_strong_lifetime: |
| case QualType::DK_objc_weak_lifetime: |
| case QualType::DK_nontrivial_c_struct: |
| // We don't care about releasing objects during process teardown. |
| assert(!D.getTLSKind() && "should have rejected this"); |
| return; |
| } |
| |
| llvm::FunctionCallee Func; |
| llvm::Constant *Argument; |
| |
| CodeGenModule &CGM = CGF.CGM; |
| QualType Type = D.getType(); |
| |
| // Special-case non-array C++ destructors, if they have the right signature. |
| // Under some ABIs, destructors return this instead of void, and cannot be |
| // passed directly to __cxa_atexit if the target does not allow this |
| // mismatch. |
| const CXXRecordDecl *Record = Type->getAsCXXRecordDecl(); |
| bool CanRegisterDestructor = |
| Record && (!CGM.getCXXABI().HasThisReturn( |
| GlobalDecl(Record->getDestructor(), Dtor_Complete)) || |
| CGM.getCXXABI().canCallMismatchedFunctionType()); |
| // If __cxa_atexit is disabled via a flag, a different helper function is |
| // generated elsewhere which uses atexit instead, and it takes the destructor |
| // directly. |
| bool UsingExternalHelper = !CGM.getCodeGenOpts().CXAAtExit; |
| if (Record && (CanRegisterDestructor || UsingExternalHelper)) { |
| assert(!Record->hasTrivialDestructor()); |
| CXXDestructorDecl *Dtor = Record->getDestructor(); |
| |
| Func = CGM.getAddrAndTypeOfCXXStructor(GlobalDecl(Dtor, Dtor_Complete)); |
| if (CGF.getContext().getLangOpts().OpenCL) { |
| auto DestAS = |
| CGM.getTargetCodeGenInfo().getAddrSpaceOfCxaAtexitPtrParam(); |
| auto DestTy = CGF.getTypes().ConvertType(Type)->getPointerTo( |
| CGM.getContext().getTargetAddressSpace(DestAS)); |
| auto SrcAS = D.getType().getQualifiers().getAddressSpace(); |
| if (DestAS == SrcAS) |
| Argument = llvm::ConstantExpr::getBitCast(Addr.getPointer(), DestTy); |
| else |
| // FIXME: On addr space mismatch we are passing NULL. The generation |
| // of the global destructor function should be adjusted accordingly. |
| Argument = llvm::ConstantPointerNull::get(DestTy); |
| } else { |
| Argument = llvm::ConstantExpr::getBitCast( |
| Addr.getPointer(), CGF.getTypes().ConvertType(Type)->getPointerTo()); |
| } |
| // Otherwise, the standard logic requires a helper function. |
| } else { |
| Func = CodeGenFunction(CGM) |
| .generateDestroyHelper(Addr, Type, CGF.getDestroyer(DtorKind), |
| CGF.needsEHCleanup(DtorKind), &D); |
| Argument = llvm::Constant::getNullValue(CGF.Int8PtrTy); |
| } |
| |
| CGM.getCXXABI().registerGlobalDtor(CGF, D, Func, Argument); |
| } |
| |
| /// Emit code to cause the variable at the given address to be considered as |
| /// constant from this point onwards. |
| static void EmitDeclInvariant(CodeGenFunction &CGF, const VarDecl &D, |
| llvm::Constant *Addr) { |
| return CGF.EmitInvariantStart( |
| Addr, CGF.getContext().getTypeSizeInChars(D.getType())); |
| } |
| |
| void CodeGenFunction::EmitInvariantStart(llvm::Constant *Addr, CharUnits Size) { |
| // Do not emit the intrinsic if we're not optimizing. |
| if (!CGM.getCodeGenOpts().OptimizationLevel) |
| return; |
| |
| // Grab the llvm.invariant.start intrinsic. |
| llvm::Intrinsic::ID InvStartID = llvm::Intrinsic::invariant_start; |
| // Overloaded address space type. |
| llvm::Type *ObjectPtr[1] = {Int8PtrTy}; |
| llvm::Function *InvariantStart = CGM.getIntrinsic(InvStartID, ObjectPtr); |
| |
| // Emit a call with the size in bytes of the object. |
| uint64_t Width = Size.getQuantity(); |
| llvm::Value *Args[2] = { llvm::ConstantInt::getSigned(Int64Ty, Width), |
| llvm::ConstantExpr::getBitCast(Addr, Int8PtrTy)}; |
| Builder.CreateCall(InvariantStart, Args); |
| } |
| |
| void CodeGenFunction::EmitCXXGlobalVarDeclInit(const VarDecl &D, |
| llvm::Constant *DeclPtr, |
| bool PerformInit) { |
| |
| const Expr *Init = D.getInit(); |
| QualType T = D.getType(); |
| |
| // The address space of a static local variable (DeclPtr) may be different |
| // from the address space of the "this" argument of the constructor. In that |
| // case, we need an addrspacecast before calling the constructor. |
| // |
| // struct StructWithCtor { |
| // __device__ StructWithCtor() {...} |
| // }; |
| // __device__ void foo() { |
| // __shared__ StructWithCtor s; |
| // ... |
| // } |
| // |
| // For example, in the above CUDA code, the static local variable s has a |
| // "shared" address space qualifier, but the constructor of StructWithCtor |
| // expects "this" in the "generic" address space. |
| unsigned ExpectedAddrSpace = getContext().getTargetAddressSpace(T); |
| unsigned ActualAddrSpace = DeclPtr->getType()->getPointerAddressSpace(); |
| if (ActualAddrSpace != ExpectedAddrSpace) { |
| llvm::Type *LTy = CGM.getTypes().ConvertTypeForMem(T); |
| llvm::PointerType *PTy = llvm::PointerType::get(LTy, ExpectedAddrSpace); |
| DeclPtr = llvm::ConstantExpr::getAddrSpaceCast(DeclPtr, PTy); |
| } |
| |
| ConstantAddress DeclAddr(DeclPtr, getContext().getDeclAlign(&D)); |
| |
| if (!T->isReferenceType()) { |
| if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd && |
| D.hasAttr<OMPThreadPrivateDeclAttr>()) { |
| (void)CGM.getOpenMPRuntime().emitThreadPrivateVarDefinition( |
| &D, DeclAddr, D.getAttr<OMPThreadPrivateDeclAttr>()->getLocation(), |
| PerformInit, this); |
| } |
| if (PerformInit) |
| EmitDeclInit(*this, D, DeclAddr); |
| if (CGM.isTypeConstant(D.getType(), true)) |
| EmitDeclInvariant(*this, D, DeclPtr); |
| else |
| EmitDeclDestroy(*this, D, DeclAddr); |
| return; |
| } |
| |
| assert(PerformInit && "cannot have constant initializer which needs " |
| "destruction for reference"); |
| RValue RV = EmitReferenceBindingToExpr(Init); |
| EmitStoreOfScalar(RV.getScalarVal(), DeclAddr, false, T); |
| } |
| |
| /// Create a stub function, suitable for being passed to atexit, |
| /// which passes the given address to the given destructor function. |
| llvm::Function *CodeGenFunction::createAtExitStub(const VarDecl &VD, |
| llvm::FunctionCallee dtor, |
| llvm::Constant *addr) { |
| // Get the destructor function type, void(*)(void). |
| llvm::FunctionType *ty = llvm::FunctionType::get(CGM.VoidTy, false); |
| SmallString<256> FnName; |
| { |
| llvm::raw_svector_ostream Out(FnName); |
| CGM.getCXXABI().getMangleContext().mangleDynamicAtExitDestructor(&VD, Out); |
| } |
| |
| const CGFunctionInfo &FI = CGM.getTypes().arrangeNullaryFunction(); |
| llvm::Function *fn = CGM.CreateGlobalInitOrDestructFunction( |
| ty, FnName.str(), FI, VD.getLocation()); |
| |
| CodeGenFunction CGF(CGM); |
| |
| CGF.StartFunction(GlobalDecl(&VD, DynamicInitKind::AtExit), |
| CGM.getContext().VoidTy, fn, FI, FunctionArgList()); |
| |
| llvm::CallInst *call = CGF.Builder.CreateCall(dtor, addr); |
| |
| // Make sure the call and the callee agree on calling convention. |
| if (auto *dtorFn = dyn_cast<llvm::Function>( |
| dtor.getCallee()->stripPointerCastsAndAliases())) |
| call->setCallingConv(dtorFn->getCallingConv()); |
| |
| CGF.FinishFunction(); |
| |
| return fn; |
| } |
| |
| /// Register a global destructor using the C atexit runtime function. |
| void CodeGenFunction::registerGlobalDtorWithAtExit(const VarDecl &VD, |
| llvm::FunctionCallee dtor, |
| llvm::Constant *addr) { |
| // Create a function which calls the destructor. |
| llvm::Constant *dtorStub = createAtExitStub(VD, dtor, addr); |
| registerGlobalDtorWithAtExit(dtorStub); |
| } |
| |
| void CodeGenFunction::registerGlobalDtorWithAtExit(llvm::Constant *dtorStub) { |
| // extern "C" int atexit(void (*f)(void)); |
| llvm::FunctionType *atexitTy = |
| llvm::FunctionType::get(IntTy, dtorStub->getType(), false); |
| |
| llvm::FunctionCallee atexit = |
| CGM.CreateRuntimeFunction(atexitTy, "atexit", llvm::AttributeList(), |
| /*Local=*/true); |
| if (llvm::Function *atexitFn = dyn_cast<llvm::Function>(atexit.getCallee())) |
| atexitFn->setDoesNotThrow(); |
| |
| EmitNounwindRuntimeCall(atexit, dtorStub); |
| } |
| |
| void CodeGenFunction::EmitCXXGuardedInit(const VarDecl &D, |
| llvm::GlobalVariable *DeclPtr, |
| bool PerformInit) { |
| // If we've been asked to forbid guard variables, emit an error now. |
| // This diagnostic is hard-coded for Darwin's use case; we can find |
| // better phrasing if someone else needs it. |
| if (CGM.getCodeGenOpts().ForbidGuardVariables) |
| CGM.Error(D.getLocation(), |
| "this initialization requires a guard variable, which " |
| "the kernel does not support"); |
| |
| CGM.getCXXABI().EmitGuardedInit(*this, D, DeclPtr, PerformInit); |
| } |
| |
| void CodeGenFunction::EmitCXXGuardedInitBranch(llvm::Value *NeedsInit, |
| llvm::BasicBlock *InitBlock, |
| llvm::BasicBlock *NoInitBlock, |
| GuardKind Kind, |
| const VarDecl *D) { |
| assert((Kind == GuardKind::TlsGuard || D) && "no guarded variable"); |
| |
| // A guess at how many times we will enter the initialization of a |
| // variable, depending on the kind of variable. |
| static const uint64_t InitsPerTLSVar = 1024; |
| static const uint64_t InitsPerLocalVar = 1024 * 1024; |
| |
| llvm::MDNode *Weights; |
| if (Kind == GuardKind::VariableGuard && !D->isLocalVarDecl()) { |
| // For non-local variables, don't apply any weighting for now. Due to our |
| // use of COMDATs, we expect there to be at most one initialization of the |
| // variable per DSO, but we have no way to know how many DSOs will try to |
| // initialize the variable. |
| Weights = nullptr; |
| } else { |
| uint64_t NumInits; |
| // FIXME: For the TLS case, collect and use profiling information to |
| // determine a more accurate brach weight. |
| if (Kind == GuardKind::TlsGuard || D->getTLSKind()) |
| NumInits = InitsPerTLSVar; |
| else |
| NumInits = InitsPerLocalVar; |
| |
| // The probability of us entering the initializer is |
| // 1 / (total number of times we attempt to initialize the variable). |
| llvm::MDBuilder MDHelper(CGM.getLLVMContext()); |
| Weights = MDHelper.createBranchWeights(1, NumInits - 1); |
| } |
| |
| Builder.CreateCondBr(NeedsInit, InitBlock, NoInitBlock, Weights); |
| } |
| |
| llvm::Function *CodeGenModule::CreateGlobalInitOrDestructFunction( |
| llvm::FunctionType *FTy, const Twine &Name, const CGFunctionInfo &FI, |
| SourceLocation Loc, bool TLS) { |
| llvm::Function *Fn = |
| llvm::Function::Create(FTy, llvm::GlobalValue::InternalLinkage, |
| Name, &getModule()); |
| if (!getLangOpts().AppleKext && !TLS) { |
| // Set the section if needed. |
| if (const char *Section = getTarget().getStaticInitSectionSpecifier()) |
| Fn->setSection(Section); |
| } |
| |
| SetInternalFunctionAttributes(GlobalDecl(), Fn, FI); |
| |
| Fn->setCallingConv(getRuntimeCC()); |
| |
| if (!getLangOpts().Exceptions) |
| Fn->setDoesNotThrow(); |
| |
| if (getLangOpts().Sanitize.has(SanitizerKind::Address) && |
| !isInSanitizerBlacklist(SanitizerKind::Address, Fn, Loc)) |
| Fn->addFnAttr(llvm::Attribute::SanitizeAddress); |
| |
| if (getLangOpts().Sanitize.has(SanitizerKind::KernelAddress) && |
| !isInSanitizerBlacklist(SanitizerKind::KernelAddress, Fn, Loc)) |
| Fn->addFnAttr(llvm::Attribute::SanitizeAddress); |
| |
| if (getLangOpts().Sanitize.has(SanitizerKind::HWAddress) && |
| !isInSanitizerBlacklist(SanitizerKind::HWAddress, Fn, Loc)) |
| Fn->addFnAttr(llvm::Attribute::SanitizeHWAddress); |
| |
| if (getLangOpts().Sanitize.has(SanitizerKind::KernelHWAddress) && |
| !isInSanitizerBlacklist(SanitizerKind::KernelHWAddress, Fn, Loc)) |
| Fn->addFnAttr(llvm::Attribute::SanitizeHWAddress); |
| |
| if (getLangOpts().Sanitize.has(SanitizerKind::MemTag) && |
| !isInSanitizerBlacklist(SanitizerKind::MemTag, Fn, Loc)) |
| Fn->addFnAttr(llvm::Attribute::SanitizeMemTag); |
| |
| if (getLangOpts().Sanitize.has(SanitizerKind::Thread) && |
| !isInSanitizerBlacklist(SanitizerKind::Thread, Fn, Loc)) |
| Fn->addFnAttr(llvm::Attribute::SanitizeThread); |
| |
| if (getLangOpts().Sanitize.has(SanitizerKind::Memory) && |
| !isInSanitizerBlacklist(SanitizerKind::Memory, Fn, Loc)) |
| Fn->addFnAttr(llvm::Attribute::SanitizeMemory); |
| |
| if (getLangOpts().Sanitize.has(SanitizerKind::KernelMemory) && |
| !isInSanitizerBlacklist(SanitizerKind::KernelMemory, Fn, Loc)) |
| Fn->addFnAttr(llvm::Attribute::SanitizeMemory); |
| |
| if (getLangOpts().Sanitize.has(SanitizerKind::SafeStack) && |
| !isInSanitizerBlacklist(SanitizerKind::SafeStack, Fn, Loc)) |
| Fn->addFnAttr(llvm::Attribute::SafeStack); |
| |
| if (getLangOpts().Sanitize.has(SanitizerKind::ShadowCallStack) && |
| !isInSanitizerBlacklist(SanitizerKind::ShadowCallStack, Fn, Loc)) |
| Fn->addFnAttr(llvm::Attribute::ShadowCallStack); |
| |
| auto RASignKind = getCodeGenOpts().getSignReturnAddress(); |
| if (RASignKind != CodeGenOptions::SignReturnAddressScope::None) { |
| Fn->addFnAttr("sign-return-address", |
| RASignKind == CodeGenOptions::SignReturnAddressScope::All |
| ? "all" |
| : "non-leaf"); |
| auto RASignKey = getCodeGenOpts().getSignReturnAddressKey(); |
| Fn->addFnAttr("sign-return-address-key", |
| RASignKey == CodeGenOptions::SignReturnAddressKeyValue::AKey |
| ? "a_key" |
| : "b_key"); |
| } |
| |
| if (getCodeGenOpts().BranchTargetEnforcement) |
| Fn->addFnAttr("branch-target-enforcement"); |
| |
| return Fn; |
| } |
| |
| /// Create a global pointer to a function that will initialize a global |
| /// variable. The user has requested that this pointer be emitted in a specific |
| /// section. |
| void CodeGenModule::EmitPointerToInitFunc(const VarDecl *D, |
| llvm::GlobalVariable *GV, |
| llvm::Function *InitFunc, |
| InitSegAttr *ISA) { |
| llvm::GlobalVariable *PtrArray = new llvm::GlobalVariable( |
| TheModule, InitFunc->getType(), /*isConstant=*/true, |
| llvm::GlobalValue::PrivateLinkage, InitFunc, "__cxx_init_fn_ptr"); |
| PtrArray->setSection(ISA->getSection()); |
| addUsedGlobal(PtrArray); |
| |
| // If the GV is already in a comdat group, then we have to join it. |
| if (llvm::Comdat *C = GV->getComdat()) |
| PtrArray->setComdat(C); |
| } |
| |
| void |
| CodeGenModule::EmitCXXGlobalVarDeclInitFunc(const VarDecl *D, |
| llvm::GlobalVariable *Addr, |
| bool PerformInit) { |
| |
| // According to E.2.3.1 in CUDA-7.5 Programming guide: __device__, |
| // __constant__ and __shared__ variables defined in namespace scope, |
| // that are of class type, cannot have a non-empty constructor. All |
| // the checks have been done in Sema by now. Whatever initializers |
| // are allowed are empty and we just need to ignore them here. |
| if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice && |
| (D->hasAttr<CUDADeviceAttr>() || D->hasAttr<CUDAConstantAttr>() || |
| D->hasAttr<CUDASharedAttr>())) |
| return; |
| |
| if (getLangOpts().OpenMP && |
| getOpenMPRuntime().emitDeclareTargetVarDefinition(D, Addr, PerformInit)) |
| return; |
| |
| // Check if we've already initialized this decl. |
| auto I = DelayedCXXInitPosition.find(D); |
| if (I != DelayedCXXInitPosition.end() && I->second == ~0U) |
| return; |
| |
| llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false); |
| SmallString<256> FnName; |
| { |
| llvm::raw_svector_ostream Out(FnName); |
| getCXXABI().getMangleContext().mangleDynamicInitializer(D, Out); |
| } |
| |
| // Create a variable initialization function. |
| llvm::Function *Fn = |
| CreateGlobalInitOrDestructFunction(FTy, FnName.str(), |
| getTypes().arrangeNullaryFunction(), |
| D->getLocation()); |
| |
| auto *ISA = D->getAttr<InitSegAttr>(); |
| CodeGenFunction(*this).GenerateCXXGlobalVarDeclInitFunc(Fn, D, Addr, |
| PerformInit); |
| |
| llvm::GlobalVariable *COMDATKey = |
| supportsCOMDAT() && D->isExternallyVisible() ? Addr : nullptr; |
| |
| if (D->getTLSKind()) { |
| // FIXME: Should we support init_priority for thread_local? |
| // FIXME: We only need to register one __cxa_thread_atexit function for the |
| // entire TU. |
| CXXThreadLocalInits.push_back(Fn); |
| CXXThreadLocalInitVars.push_back(D); |
| } else if (PerformInit && ISA) { |
| EmitPointerToInitFunc(D, Addr, Fn, ISA); |
| } else if (auto *IPA = D->getAttr<InitPriorityAttr>()) { |
| OrderGlobalInits Key(IPA->getPriority(), PrioritizedCXXGlobalInits.size()); |
| PrioritizedCXXGlobalInits.push_back(std::make_pair(Key, Fn)); |
| } else if (isTemplateInstantiation(D->getTemplateSpecializationKind()) || |
| getContext().GetGVALinkageForVariable(D) == GVA_DiscardableODR) { |
| // C++ [basic.start.init]p2: |
| // Definitions of explicitly specialized class template static data |
| // members have ordered initialization. Other class template static data |
| // members (i.e., implicitly or explicitly instantiated specializations) |
| // have unordered initialization. |
| // |
| // As a consequence, we can put them into their own llvm.global_ctors entry. |
| // |
| // If the global is externally visible, put the initializer into a COMDAT |
| // group with the global being initialized. On most platforms, this is a |
| // minor startup time optimization. In the MS C++ ABI, there are no guard |
| // variables, so this COMDAT key is required for correctness. |
| AddGlobalCtor(Fn, 65535, COMDATKey); |
| if (getTarget().getCXXABI().isMicrosoft() && COMDATKey) { |
| // In The MS C++, MS add template static data member in the linker |
| // drective. |
| addUsedGlobal(COMDATKey); |
| } |
| } else if (D->hasAttr<SelectAnyAttr>()) { |
| // SelectAny globals will be comdat-folded. Put the initializer into a |
| // COMDAT group associated with the global, so the initializers get folded |
| // too. |
| AddGlobalCtor(Fn, 65535, COMDATKey); |
| } else { |
| I = DelayedCXXInitPosition.find(D); // Re-do lookup in case of re-hash. |
| if (I == DelayedCXXInitPosition.end()) { |
| CXXGlobalInits.push_back(Fn); |
| } else if (I->second != ~0U) { |
| assert(I->second < CXXGlobalInits.size() && |
| CXXGlobalInits[I->second] == nullptr); |
| CXXGlobalInits[I->second] = Fn; |
| } |
| } |
| |
| // Remember that we already emitted the initializer for this global. |
| DelayedCXXInitPosition[D] = ~0U; |
| } |
| |
| void CodeGenModule::EmitCXXThreadLocalInitFunc() { |
| getCXXABI().EmitThreadLocalInitFuncs( |
| *this, CXXThreadLocals, CXXThreadLocalInits, CXXThreadLocalInitVars); |
| |
| CXXThreadLocalInits.clear(); |
| CXXThreadLocalInitVars.clear(); |
| CXXThreadLocals.clear(); |
| } |
| |
| void |
| CodeGenModule::EmitCXXGlobalInitFunc() { |
| while (!CXXGlobalInits.empty() && !CXXGlobalInits.back()) |
| CXXGlobalInits.pop_back(); |
| |
| if (CXXGlobalInits.empty() && PrioritizedCXXGlobalInits.empty()) |
| return; |
| |
| llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false); |
| const CGFunctionInfo &FI = getTypes().arrangeNullaryFunction(); |
| |
| // Create our global initialization function. |
| if (!PrioritizedCXXGlobalInits.empty()) { |
| SmallVector<llvm::Function *, 8> LocalCXXGlobalInits; |
| llvm::array_pod_sort(PrioritizedCXXGlobalInits.begin(), |
| PrioritizedCXXGlobalInits.end()); |
| // Iterate over "chunks" of ctors with same priority and emit each chunk |
| // into separate function. Note - everything is sorted first by priority, |
| // second - by lex order, so we emit ctor functions in proper order. |
| for (SmallVectorImpl<GlobalInitData >::iterator |
| I = PrioritizedCXXGlobalInits.begin(), |
| E = PrioritizedCXXGlobalInits.end(); I != E; ) { |
| SmallVectorImpl<GlobalInitData >::iterator |
| PrioE = std::upper_bound(I + 1, E, *I, GlobalInitPriorityCmp()); |
| |
| LocalCXXGlobalInits.clear(); |
| unsigned Priority = I->first.priority; |
| // Compute the function suffix from priority. Prepend with zeroes to make |
| // sure the function names are also ordered as priorities. |
| std::string PrioritySuffix = llvm::utostr(Priority); |
| // Priority is always <= 65535 (enforced by sema). |
| PrioritySuffix = std::string(6-PrioritySuffix.size(), '0')+PrioritySuffix; |
| llvm::Function *Fn = CreateGlobalInitOrDestructFunction( |
| FTy, "_GLOBAL__I_" + PrioritySuffix, FI); |
| |
| for (; I < PrioE; ++I) |
| LocalCXXGlobalInits.push_back(I->second); |
| |
| CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, LocalCXXGlobalInits); |
| AddGlobalCtor(Fn, Priority); |
| } |
| PrioritizedCXXGlobalInits.clear(); |
| } |
| |
| // Include the filename in the symbol name. Including "sub_" matches gcc and |
| // makes sure these symbols appear lexicographically behind the symbols with |
| // priority emitted above. |
| SmallString<128> FileName = llvm::sys::path::filename(getModule().getName()); |
| if (FileName.empty()) |
| FileName = "<null>"; |
| |
| for (size_t i = 0; i < FileName.size(); ++i) { |
| // Replace everything that's not [a-zA-Z0-9._] with a _. This set happens |
| // to be the set of C preprocessing numbers. |
| if (!isPreprocessingNumberBody(FileName[i])) |
| FileName[i] = '_'; |
| } |
| |
| llvm::Function *Fn = CreateGlobalInitOrDestructFunction( |
| FTy, llvm::Twine("_GLOBAL__sub_I_", FileName), FI); |
| |
| CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, CXXGlobalInits); |
| AddGlobalCtor(Fn); |
| |
| // In OpenCL global init functions must be converted to kernels in order to |
| // be able to launch them from the host. |
| // FIXME: Some more work might be needed to handle destructors correctly. |
| // Current initialization function makes use of function pointers callbacks. |
| // We can't support function pointers especially between host and device. |
| // However it seems global destruction has little meaning without any |
| // dynamic resource allocation on the device and program scope variables are |
| // destroyed by the runtime when program is released. |
| if (getLangOpts().OpenCL) { |
| GenOpenCLArgMetadata(Fn); |
| Fn->setCallingConv(llvm::CallingConv::SPIR_KERNEL); |
| } |
| |
| CXXGlobalInits.clear(); |
| } |
| |
| void CodeGenModule::EmitCXXGlobalDtorFunc() { |
| if (CXXGlobalDtors.empty()) |
| return; |
| |
| llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false); |
| |
| // Create our global destructor function. |
| const CGFunctionInfo &FI = getTypes().arrangeNullaryFunction(); |
| llvm::Function *Fn = |
| CreateGlobalInitOrDestructFunction(FTy, "_GLOBAL__D_a", FI); |
| |
| CodeGenFunction(*this).GenerateCXXGlobalDtorsFunc(Fn, CXXGlobalDtors); |
| AddGlobalDtor(Fn); |
| } |
| |
| /// Emit the code necessary to initialize the given global variable. |
| void CodeGenFunction::GenerateCXXGlobalVarDeclInitFunc(llvm::Function *Fn, |
| const VarDecl *D, |
| llvm::GlobalVariable *Addr, |
| bool PerformInit) { |
| // Check if we need to emit debug info for variable initializer. |
| if (D->hasAttr<NoDebugAttr>()) |
| DebugInfo = nullptr; // disable debug info indefinitely for this function |
| |
| CurEHLocation = D->getBeginLoc(); |
| |
| StartFunction(GlobalDecl(D, DynamicInitKind::Initializer), |
| getContext().VoidTy, Fn, getTypes().arrangeNullaryFunction(), |
| FunctionArgList(), D->getLocation(), |
| D->getInit()->getExprLoc()); |
| |
| // Use guarded initialization if the global variable is weak. This |
| // occurs for, e.g., instantiated static data members and |
| // definitions explicitly marked weak. |
| // |
| // Also use guarded initialization for a variable with dynamic TLS and |
| // unordered initialization. (If the initialization is ordered, the ABI |
| // layer will guard the whole-TU initialization for us.) |
| if (Addr->hasWeakLinkage() || Addr->hasLinkOnceLinkage() || |
| (D->getTLSKind() == VarDecl::TLS_Dynamic && |
| isTemplateInstantiation(D->getTemplateSpecializationKind()))) { |
| EmitCXXGuardedInit(*D, Addr, PerformInit); |
| } else { |
| EmitCXXGlobalVarDeclInit(*D, Addr, PerformInit); |
| } |
| |
| FinishFunction(); |
| } |
| |
| void |
| CodeGenFunction::GenerateCXXGlobalInitFunc(llvm::Function *Fn, |
| ArrayRef<llvm::Function *> Decls, |
| ConstantAddress Guard) { |
| { |
| auto NL = ApplyDebugLocation::CreateEmpty(*this); |
| StartFunction(GlobalDecl(), getContext().VoidTy, Fn, |
| getTypes().arrangeNullaryFunction(), FunctionArgList()); |
| // Emit an artificial location for this function. |
| auto AL = ApplyDebugLocation::CreateArtificial(*this); |
| |
| llvm::BasicBlock *ExitBlock = nullptr; |
| if (Guard.isValid()) { |
| // If we have a guard variable, check whether we've already performed |
| // these initializations. This happens for TLS initialization functions. |
| llvm::Value *GuardVal = Builder.CreateLoad(Guard); |
| llvm::Value *Uninit = Builder.CreateIsNull(GuardVal, |
| "guard.uninitialized"); |
| llvm::BasicBlock *InitBlock = createBasicBlock("init"); |
| ExitBlock = createBasicBlock("exit"); |
| EmitCXXGuardedInitBranch(Uninit, InitBlock, ExitBlock, |
| GuardKind::TlsGuard, nullptr); |
| EmitBlock(InitBlock); |
| // Mark as initialized before initializing anything else. If the |
| // initializers use previously-initialized thread_local vars, that's |
| // probably supposed to be OK, but the standard doesn't say. |
| Builder.CreateStore(llvm::ConstantInt::get(GuardVal->getType(),1), Guard); |
| |
| // The guard variable can't ever change again. |
| EmitInvariantStart( |
| Guard.getPointer(), |
| CharUnits::fromQuantity( |
| CGM.getDataLayout().getTypeAllocSize(GuardVal->getType()))); |
| } |
| |
| RunCleanupsScope Scope(*this); |
| |
| // When building in Objective-C++ ARC mode, create an autorelease pool |
| // around the global initializers. |
| if (getLangOpts().ObjCAutoRefCount && getLangOpts().CPlusPlus) { |
| llvm::Value *token = EmitObjCAutoreleasePoolPush(); |
| EmitObjCAutoreleasePoolCleanup(token); |
| } |
| |
| for (unsigned i = 0, e = Decls.size(); i != e; ++i) |
| if (Decls[i]) |
| EmitRuntimeCall(Decls[i]); |
| |
| Scope.ForceCleanup(); |
| |
| if (ExitBlock) { |
| Builder.CreateBr(ExitBlock); |
| EmitBlock(ExitBlock); |
| } |
| } |
| |
| FinishFunction(); |
| } |
| |
| void CodeGenFunction::GenerateCXXGlobalDtorsFunc( |
| llvm::Function *Fn, |
| const std::vector<std::tuple<llvm::FunctionType *, llvm::WeakTrackingVH, |
| llvm::Constant *>> &DtorsAndObjects) { |
| { |
| auto NL = ApplyDebugLocation::CreateEmpty(*this); |
| StartFunction(GlobalDecl(), getContext().VoidTy, Fn, |
| getTypes().arrangeNullaryFunction(), FunctionArgList()); |
| // Emit an artificial location for this function. |
| auto AL = ApplyDebugLocation::CreateArtificial(*this); |
| |
| // Emit the dtors, in reverse order from construction. |
| for (unsigned i = 0, e = DtorsAndObjects.size(); i != e; ++i) { |
| llvm::FunctionType *CalleeTy; |
| llvm::Value *Callee; |
| llvm::Constant *Arg; |
| std::tie(CalleeTy, Callee, Arg) = DtorsAndObjects[e - i - 1]; |
| llvm::CallInst *CI = Builder.CreateCall(CalleeTy, Callee, Arg); |
| // Make sure the call and the callee agree on calling convention. |
| if (llvm::Function *F = dyn_cast<llvm::Function>(Callee)) |
| CI->setCallingConv(F->getCallingConv()); |
| } |
| } |
| |
| FinishFunction(); |
| } |
| |
| /// generateDestroyHelper - Generates a helper function which, when |
| /// invoked, destroys the given object. The address of the object |
| /// should be in global memory. |
| llvm::Function *CodeGenFunction::generateDestroyHelper( |
| Address addr, QualType type, Destroyer *destroyer, |
| bool useEHCleanupForArray, const VarDecl *VD) { |
| FunctionArgList args; |
| ImplicitParamDecl Dst(getContext(), getContext().VoidPtrTy, |
| ImplicitParamDecl::Other); |
| args.push_back(&Dst); |
| |
| const CGFunctionInfo &FI = |
| CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, args); |
| llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(FI); |
| llvm::Function *fn = CGM.CreateGlobalInitOrDestructFunction( |
| FTy, "__cxx_global_array_dtor", FI, VD->getLocation()); |
| |
| CurEHLocation = VD->getBeginLoc(); |
| |
| StartFunction(VD, getContext().VoidTy, fn, FI, args); |
| |
| emitDestroy(addr, type, destroyer, useEHCleanupForArray); |
| |
| FinishFunction(); |
| |
| return fn; |
| } |
