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Diffstat (limited to 'contrib/llvm/tools/clang/lib/CodeGen/CGDeclCXX.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/CodeGen/CGDeclCXX.cpp | 424 |
1 files changed, 424 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/CodeGen/CGDeclCXX.cpp b/contrib/llvm/tools/clang/lib/CodeGen/CGDeclCXX.cpp new file mode 100644 index 000000000000..f94ddd988662 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/CodeGen/CGDeclCXX.cpp @@ -0,0 +1,424 @@ +//===--- CGDeclCXX.cpp - Emit LLVM Code for C++ declarations --------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This contains code dealing with code generation of C++ declarations +// +//===----------------------------------------------------------------------===// + +#include "CodeGenFunction.h" +#include "clang/CodeGen/CodeGenOptions.h" +#include "llvm/Intrinsics.h" + +using namespace clang; +using namespace CodeGen; + +static void EmitDeclInit(CodeGenFunction &CGF, const VarDecl &D, + llvm::Constant *DeclPtr) { + assert(D.hasGlobalStorage() && "VarDecl must have global storage!"); + assert(!D.getType()->isReferenceType() && + "Should not call EmitDeclInit on a reference!"); + + ASTContext &Context = CGF.getContext(); + + const Expr *Init = D.getInit(); + QualType T = D.getType(); + bool isVolatile = Context.getCanonicalType(T).isVolatileQualified(); + + if (!CGF.hasAggregateLLVMType(T)) { + llvm::Value *V = CGF.EmitScalarExpr(Init); + CGF.EmitStoreOfScalar(V, DeclPtr, isVolatile, T); + } else if (T->isAnyComplexType()) { + CGF.EmitComplexExprIntoAddr(Init, DeclPtr, isVolatile); + } else { + CGF.EmitAggExpr(Init, DeclPtr, isVolatile); + } +} + +static void EmitDeclDestroy(CodeGenFunction &CGF, const VarDecl &D, + llvm::Constant *DeclPtr) { + CodeGenModule &CGM = CGF.CGM; + ASTContext &Context = CGF.getContext(); + + const Expr *Init = D.getInit(); + QualType T = D.getType(); + if (!CGF.hasAggregateLLVMType(T) || T->isAnyComplexType()) + return; + + // Avoid generating destructor(s) for initialized objects. + if (!isa<CXXConstructExpr>(Init)) + return; + + const ConstantArrayType *Array = Context.getAsConstantArrayType(T); + if (Array) + T = Context.getBaseElementType(Array); + + const RecordType *RT = T->getAs<RecordType>(); + if (!RT) + return; + + CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); + if (RD->hasTrivialDestructor()) + return; + + CXXDestructorDecl *Dtor = RD->getDestructor(Context); + + llvm::Constant *DtorFn; + if (Array) { + DtorFn = + CodeGenFunction(CGM).GenerateCXXAggrDestructorHelper(Dtor, + Array, + DeclPtr); + const llvm::Type *Int8PtrTy = + llvm::Type::getInt8PtrTy(CGM.getLLVMContext()); + DeclPtr = llvm::Constant::getNullValue(Int8PtrTy); + } else + DtorFn = CGM.GetAddrOfCXXDestructor(Dtor, Dtor_Complete); + + CGF.EmitCXXGlobalDtorRegistration(DtorFn, DeclPtr); +} + +void CodeGenFunction::EmitCXXGlobalVarDeclInit(const VarDecl &D, + llvm::Constant *DeclPtr) { + + const Expr *Init = D.getInit(); + QualType T = D.getType(); + + if (!T->isReferenceType()) { + EmitDeclInit(*this, D, DeclPtr); + EmitDeclDestroy(*this, D, DeclPtr); + return; + } + if (Init->isLvalue(getContext()) == Expr::LV_Valid) { + RValue RV = EmitReferenceBindingToExpr(Init, /*IsInitializer=*/true); + EmitStoreOfScalar(RV.getScalarVal(), DeclPtr, false, T); + return; + } + ErrorUnsupported(Init, + "global variable that binds reference to a non-lvalue"); +} + +void +CodeGenFunction::EmitCXXGlobalDtorRegistration(llvm::Constant *DtorFn, + llvm::Constant *DeclPtr) { + // Generate a global destructor entry if not using __cxa_atexit. + if (!CGM.getCodeGenOpts().CXAAtExit) { + CGM.AddCXXDtorEntry(DtorFn, DeclPtr); + return; + } + + const llvm::Type *Int8PtrTy = + llvm::Type::getInt8Ty(VMContext)->getPointerTo(); + + std::vector<const llvm::Type *> Params; + Params.push_back(Int8PtrTy); + + // Get the destructor function type + const llvm::Type *DtorFnTy = + llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), Params, false); + DtorFnTy = llvm::PointerType::getUnqual(DtorFnTy); + + Params.clear(); + Params.push_back(DtorFnTy); + Params.push_back(Int8PtrTy); + Params.push_back(Int8PtrTy); + + // Get the __cxa_atexit function type + // extern "C" int __cxa_atexit ( void (*f)(void *), void *p, void *d ); + const llvm::FunctionType *AtExitFnTy = + llvm::FunctionType::get(ConvertType(getContext().IntTy), Params, false); + + llvm::Constant *AtExitFn = CGM.CreateRuntimeFunction(AtExitFnTy, + "__cxa_atexit"); + + llvm::Constant *Handle = CGM.CreateRuntimeVariable(Int8PtrTy, + "__dso_handle"); + llvm::Value *Args[3] = { llvm::ConstantExpr::getBitCast(DtorFn, DtorFnTy), + llvm::ConstantExpr::getBitCast(DeclPtr, Int8PtrTy), + llvm::ConstantExpr::getBitCast(Handle, Int8PtrTy) }; + Builder.CreateCall(AtExitFn, &Args[0], llvm::array_endof(Args)); +} + +void +CodeGenModule::EmitCXXGlobalVarDeclInitFunc(const VarDecl *D) { + const llvm::FunctionType *FTy + = llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), + false); + + // Create a variable initialization function. + llvm::Function *Fn = + llvm::Function::Create(FTy, llvm::GlobalValue::InternalLinkage, + "__cxx_global_var_init", &TheModule); + + CodeGenFunction(*this).GenerateCXXGlobalVarDeclInitFunc(Fn, D); + + CXXGlobalInits.push_back(Fn); +} + +void +CodeGenModule::EmitCXXGlobalInitFunc() { + if (CXXGlobalInits.empty()) + return; + + const llvm::FunctionType *FTy + = llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), + false); + + // Create our global initialization function. + llvm::Function *Fn = + llvm::Function::Create(FTy, llvm::GlobalValue::InternalLinkage, + "_GLOBAL__I_a", &TheModule); + + CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, + &CXXGlobalInits[0], + CXXGlobalInits.size()); + AddGlobalCtor(Fn); +} + +void CodeGenModule::AddCXXDtorEntry(llvm::Constant *DtorFn, + llvm::Constant *Object) { + CXXGlobalDtors.push_back(std::make_pair(DtorFn, Object)); +} + +void CodeGenModule::EmitCXXGlobalDtorFunc() { + if (CXXGlobalDtors.empty()) + return; + + const llvm::FunctionType *FTy + = llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), + false); + + // Create our global destructor function. + llvm::Function *Fn = + llvm::Function::Create(FTy, llvm::GlobalValue::InternalLinkage, + "_GLOBAL__D_a", &TheModule); + + CodeGenFunction(*this).GenerateCXXGlobalDtorFunc(Fn, CXXGlobalDtors); + AddGlobalDtor(Fn); +} + +void CodeGenFunction::GenerateCXXGlobalVarDeclInitFunc(llvm::Function *Fn, + const VarDecl *D) { + StartFunction(GlobalDecl(), getContext().VoidTy, Fn, FunctionArgList(), + SourceLocation()); + + llvm::Constant *DeclPtr = CGM.GetAddrOfGlobalVar(D); + EmitCXXGlobalVarDeclInit(*D, DeclPtr); + + FinishFunction(); +} + +void CodeGenFunction::GenerateCXXGlobalInitFunc(llvm::Function *Fn, + llvm::Constant **Decls, + unsigned NumDecls) { + StartFunction(GlobalDecl(), getContext().VoidTy, Fn, FunctionArgList(), + SourceLocation()); + + for (unsigned i = 0; i != NumDecls; ++i) + Builder.CreateCall(Decls[i]); + + FinishFunction(); +} + +void CodeGenFunction::GenerateCXXGlobalDtorFunc(llvm::Function *Fn, + const std::vector<std::pair<llvm::Constant*, llvm::Constant*> > + &DtorsAndObjects) { + StartFunction(GlobalDecl(), getContext().VoidTy, Fn, FunctionArgList(), + SourceLocation()); + + // Emit the dtors, in reverse order from construction. + for (unsigned i = 0, e = DtorsAndObjects.size(); i != e; ++i) { + llvm::Constant *Callee = DtorsAndObjects[e - i - 1].first; + llvm::CallInst *CI = Builder.CreateCall(Callee, + DtorsAndObjects[e - i - 1].second); + // 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(); +} + +static llvm::Constant *getGuardAcquireFn(CodeGenFunction &CGF) { + // int __cxa_guard_acquire(__int64_t *guard_object); + + const llvm::Type *Int64PtrTy = + llvm::Type::getInt64PtrTy(CGF.getLLVMContext()); + + std::vector<const llvm::Type*> Args(1, Int64PtrTy); + + const llvm::FunctionType *FTy = + llvm::FunctionType::get(CGF.ConvertType(CGF.getContext().IntTy), + Args, /*isVarArg=*/false); + + return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_guard_acquire"); +} + +static llvm::Constant *getGuardReleaseFn(CodeGenFunction &CGF) { + // void __cxa_guard_release(__int64_t *guard_object); + + const llvm::Type *Int64PtrTy = + llvm::Type::getInt64PtrTy(CGF.getLLVMContext()); + + std::vector<const llvm::Type*> Args(1, Int64PtrTy); + + const llvm::FunctionType *FTy = + llvm::FunctionType::get(llvm::Type::getVoidTy(CGF.getLLVMContext()), + Args, /*isVarArg=*/false); + + return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_guard_release"); +} + +static llvm::Constant *getGuardAbortFn(CodeGenFunction &CGF) { + // void __cxa_guard_abort(__int64_t *guard_object); + + const llvm::Type *Int64PtrTy = + llvm::Type::getInt64PtrTy(CGF.getLLVMContext()); + + std::vector<const llvm::Type*> Args(1, Int64PtrTy); + + const llvm::FunctionType *FTy = + llvm::FunctionType::get(llvm::Type::getVoidTy(CGF.getLLVMContext()), + Args, /*isVarArg=*/false); + + return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_guard_abort"); +} + +void +CodeGenFunction::EmitStaticCXXBlockVarDeclInit(const VarDecl &D, + llvm::GlobalVariable *GV) { + // Bail out early if this initializer isn't reachable. + if (!Builder.GetInsertBlock()) return; + + bool ThreadsafeStatics = getContext().getLangOptions().ThreadsafeStatics; + + llvm::SmallString<256> GuardVName; + CGM.getMangleContext().mangleGuardVariable(&D, GuardVName); + + // Create the guard variable. + const llvm::Type *Int64Ty = llvm::Type::getInt64Ty(VMContext); + llvm::GlobalValue *GuardVariable = + new llvm::GlobalVariable(CGM.getModule(), Int64Ty, + false, GV->getLinkage(), + llvm::Constant::getNullValue(Int64Ty), + GuardVName.str()); + + // Load the first byte of the guard variable. + const llvm::Type *PtrTy + = llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext), 0); + llvm::Value *V = + Builder.CreateLoad(Builder.CreateBitCast(GuardVariable, PtrTy), "tmp"); + + llvm::BasicBlock *InitCheckBlock = createBasicBlock("init.check"); + llvm::BasicBlock *EndBlock = createBasicBlock("init.end"); + + // Check if the first byte of the guard variable is zero. + Builder.CreateCondBr(Builder.CreateIsNull(V, "tobool"), + InitCheckBlock, EndBlock); + + EmitBlock(InitCheckBlock); + + // Variables used when coping with thread-safe statics and exceptions. + llvm::BasicBlock *SavedLandingPad = 0; + llvm::BasicBlock *LandingPad = 0; + if (ThreadsafeStatics) { + // Call __cxa_guard_acquire. + V = Builder.CreateCall(getGuardAcquireFn(*this), GuardVariable); + + llvm::BasicBlock *InitBlock = createBasicBlock("init"); + + Builder.CreateCondBr(Builder.CreateIsNotNull(V, "tobool"), + InitBlock, EndBlock); + + if (Exceptions) { + SavedLandingPad = getInvokeDest(); + LandingPad = createBasicBlock("guard.lpad"); + setInvokeDest(LandingPad); + } + + EmitBlock(InitBlock); + } + + if (D.getType()->isReferenceType()) { + QualType T = D.getType(); + // We don't want to pass true for IsInitializer here, because a static + // reference to a temporary does not extend its lifetime. + RValue RV = EmitReferenceBindingToExpr(D.getInit(), + /*IsInitializer=*/false); + EmitStoreOfScalar(RV.getScalarVal(), GV, /*Volatile=*/false, T); + + } else + EmitDeclInit(*this, D, GV); + + if (ThreadsafeStatics) { + // Call __cxa_guard_release. + Builder.CreateCall(getGuardReleaseFn(*this), GuardVariable); + } else { + llvm::Value *One = + llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), 1); + Builder.CreateStore(One, Builder.CreateBitCast(GuardVariable, PtrTy)); + } + + // Register the call to the destructor. + if (!D.getType()->isReferenceType()) + EmitDeclDestroy(*this, D, GV); + + if (ThreadsafeStatics && Exceptions) { + // If an exception is thrown during initialization, call __cxa_guard_abort + // along the exceptional edge. + EmitBranch(EndBlock); + + // Construct the landing pad. + EmitBlock(LandingPad); + + // Personality function and LLVM intrinsics. + llvm::Constant *Personality = + CGM.CreateRuntimeFunction(llvm::FunctionType::get(llvm::Type::getInt32Ty + (VMContext), + true), + "__gxx_personality_v0"); + Personality = llvm::ConstantExpr::getBitCast(Personality, PtrToInt8Ty); + llvm::Value *llvm_eh_exception = + CGM.getIntrinsic(llvm::Intrinsic::eh_exception); + llvm::Value *llvm_eh_selector = + CGM.getIntrinsic(llvm::Intrinsic::eh_selector); + + // Exception object + llvm::Value *Exc = Builder.CreateCall(llvm_eh_exception, "exc"); + llvm::Value *RethrowPtr = CreateTempAlloca(Exc->getType(), "_rethrow"); + + // Call the selector function. + const llvm::PointerType *PtrToInt8Ty + = llvm::PointerType::getUnqual(llvm::Type::getInt8Ty(VMContext)); + llvm::Constant *Null = llvm::ConstantPointerNull::get(PtrToInt8Ty); + llvm::Value* SelectorArgs[3] = { Exc, Personality, Null }; + Builder.CreateCall(llvm_eh_selector, SelectorArgs, SelectorArgs + 3, + "selector"); + Builder.CreateStore(Exc, RethrowPtr); + + // Call __cxa_guard_abort along the exceptional edge. + Builder.CreateCall(getGuardAbortFn(*this), GuardVariable); + + setInvokeDest(SavedLandingPad); + + // Rethrow the current exception. + if (getInvokeDest()) { + llvm::BasicBlock *Cont = createBasicBlock("invoke.cont"); + Builder.CreateInvoke(getUnwindResumeOrRethrowFn(), Cont, + getInvokeDest(), + Builder.CreateLoad(RethrowPtr)); + EmitBlock(Cont); + } else + Builder.CreateCall(getUnwindResumeOrRethrowFn(), + Builder.CreateLoad(RethrowPtr)); + + Builder.CreateUnreachable(); + } + + EmitBlock(EndBlock); +} |