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Diffstat (limited to 'lib/CodeGen/CGDeclCXX.cpp')
| -rw-r--r-- | lib/CodeGen/CGDeclCXX.cpp | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/lib/CodeGen/CGDeclCXX.cpp b/lib/CodeGen/CGDeclCXX.cpp new file mode 100644 index 0000000..0b6ea5a --- /dev/null +++ b/lib/CodeGen/CGDeclCXX.cpp @@ -0,0 +1,211 @@ +//===--- 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" +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!"); + + CodeGenModule &CGM = CGF.CGM; + 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); + + // 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); + return; + } + + ErrorUnsupported(Init, "global variable that binds to a reference"); +} + +void +CodeGenFunction::EmitCXXGlobalDtorRegistration(llvm::Constant *DtorFn, + llvm::Constant *DeclPtr) { + 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::EmitCXXGlobalInitFunc() { + if (CXXGlobalInits.empty()) + return; + + const llvm::FunctionType *FTy + = llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), + false); + + // Create our global initialization function. + // FIXME: Should this be tweakable by targets? + llvm::Function *Fn = + llvm::Function::Create(FTy, llvm::GlobalValue::InternalLinkage, + "__cxx_global_initialization", &TheModule); + + CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, + &CXXGlobalInits[0], + CXXGlobalInits.size()); + AddGlobalCtor(Fn); +} + +void CodeGenFunction::GenerateCXXGlobalInitFunc(llvm::Function *Fn, + const VarDecl **Decls, + unsigned NumDecls) { + StartFunction(GlobalDecl(), getContext().VoidTy, Fn, FunctionArgList(), + SourceLocation()); + + for (unsigned i = 0; i != NumDecls; ++i) { + const VarDecl *D = Decls[i]; + + llvm::Constant *DeclPtr = CGM.GetAddrOfGlobalVar(D); + EmitCXXGlobalVarDeclInit(*D, DeclPtr); + } + FinishFunction(); +} + +void +CodeGenFunction::EmitStaticCXXBlockVarDeclInit(const VarDecl &D, + llvm::GlobalVariable *GV) { + // FIXME: This should use __cxa_guard_{acquire,release}? + + assert(!getContext().getLangOptions().ThreadsafeStatics && + "thread safe statics are currently not supported!"); + + llvm::SmallString<256> GuardVName; + CGM.getMangleContext().mangleGuardVariable(&D, GuardVName); + + // Create the guard variable. + llvm::GlobalValue *GuardV = + new llvm::GlobalVariable(CGM.getModule(), llvm::Type::getInt64Ty(VMContext), + false, GV->getLinkage(), + llvm::Constant::getNullValue(llvm::Type::getInt64Ty(VMContext)), + 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(GuardV, PtrTy), + "tmp"); + + // Compare it against 0. + llvm::Value *nullValue + = llvm::Constant::getNullValue(llvm::Type::getInt8Ty(VMContext)); + llvm::Value *ICmp = Builder.CreateICmpEQ(V, nullValue , "tobool"); + + llvm::BasicBlock *InitBlock = createBasicBlock("init"); + llvm::BasicBlock *EndBlock = createBasicBlock("init.end"); + + // If the guard variable is 0, jump to the initializer code. + Builder.CreateCondBr(ICmp, InitBlock, EndBlock); + + 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(), T, + /*IsInitializer=*/false); + EmitStoreOfScalar(RV.getScalarVal(), GV, /*Volatile=*/false, T); + + } else + EmitDeclInit(*this, D, GV); + + Builder.CreateStore(llvm::ConstantInt::get(llvm::Type::getInt8Ty(VMContext), + 1), + Builder.CreateBitCast(GuardV, PtrTy)); + + EmitBlock(EndBlock); +} |
