diff options
Diffstat (limited to 'contrib/llvm/tools/clang/lib/CodeGen/CGDeclCXX.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/CodeGen/CGDeclCXX.cpp | 368 |
1 files changed, 368 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 0000000..3b8f830 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/CodeGen/CGDeclCXX.cpp @@ -0,0 +1,368 @@ +//===--- 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 "CGObjCRuntime.h" +#include "CGCXXABI.h" +#include "clang/Frontend/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(); + + unsigned alignment = Context.getDeclAlign(&D).getQuantity(); + QualType type = D.getType(); + LValue lv = CGF.MakeAddrLValue(DeclPtr, type, alignment); + + const Expr *Init = D.getInit(); + if (!CGF.hasAggregateLLVMType(type)) { + CodeGenModule &CGM = CGF.CGM; + if (lv.isObjCStrong()) + CGM.getObjCRuntime().EmitObjCGlobalAssign(CGF, CGF.EmitScalarExpr(Init), + DeclPtr, D.isThreadSpecified()); + else if (lv.isObjCWeak()) + CGM.getObjCRuntime().EmitObjCWeakAssign(CGF, CGF.EmitScalarExpr(Init), + DeclPtr); + else + CGF.EmitScalarInit(Init, &D, lv, false); + } else if (type->isAnyComplexType()) { + CGF.EmitComplexExprIntoAddr(Init, DeclPtr, lv.isVolatile()); + } else { + CGF.EmitAggExpr(Init, AggValueSlot::forLValue(lv,AggValueSlot::IsDestructed, + AggValueSlot::DoesNotNeedGCBarriers, + AggValueSlot::IsNotAliased)); + } +} + +/// Emit code to cause the destruction of the given variable with +/// static storage duration. +static void EmitDeclDestroy(CodeGenFunction &CGF, const VarDecl &D, + llvm::Constant *addr) { + CodeGenModule &CGM = CGF.CGM; + + // FIXME: __attribute__((cleanup)) ? + + QualType type = D.getType(); + QualType::DestructionKind dtorKind = type.isDestructedType(); + + 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: + // We don't care about releasing objects during process teardown. + return; + } + + llvm::Constant *function; + llvm::Constant *argument; + + // Special-case non-array C++ destructors, where there's a function + // with the right signature that we can just call. + const CXXRecordDecl *record = 0; + if (dtorKind == QualType::DK_cxx_destructor && + (record = type->getAsCXXRecordDecl())) { + assert(!record->hasTrivialDestructor()); + CXXDestructorDecl *dtor = record->getDestructor(); + + function = CGM.GetAddrOfCXXDestructor(dtor, Dtor_Complete); + argument = addr; + + // Otherwise, the standard logic requires a helper function. + } else { + function = CodeGenFunction(CGM).generateDestroyHelper(addr, type, + CGF.getDestroyer(dtorKind), + CGF.needsEHCleanup(dtorKind)); + argument = llvm::Constant::getNullValue(CGF.Int8PtrTy); + } + + CGF.EmitCXXGlobalDtorRegistration(function, argument); +} + +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; + } + + unsigned Alignment = getContext().getDeclAlign(&D).getQuantity(); + RValue RV = EmitReferenceBindingToExpr(Init, &D); + EmitStoreOfScalar(RV.getScalarVal(), DeclPtr, false, Alignment, T); +} + +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; + } + + // Get the destructor function type + llvm::Type *DtorFnTy = + llvm::FunctionType::get(llvm::Type::getVoidTy(getLLVMContext()), + Int8PtrTy, false); + DtorFnTy = llvm::PointerType::getUnqual(DtorFnTy); + + llvm::Type *Params[] = { DtorFnTy, Int8PtrTy, Int8PtrTy }; + + // Get the __cxa_atexit function type + // extern "C" int __cxa_atexit ( void (*f)(void *), void *p, void *d ); + llvm::FunctionType *AtExitFnTy = + llvm::FunctionType::get(ConvertType(getContext().IntTy), Params, false); + + llvm::Constant *AtExitFn = CGM.CreateRuntimeFunction(AtExitFnTy, + "__cxa_atexit"); + if (llvm::Function *Fn = dyn_cast<llvm::Function>(AtExitFn)) + Fn->setDoesNotThrow(); + + 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); +} + +void CodeGenFunction::EmitCXXGuardedInit(const VarDecl &D, + llvm::GlobalVariable *DeclPtr) { + // 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); +} + +static llvm::Function * +CreateGlobalInitOrDestructFunction(CodeGenModule &CGM, + llvm::FunctionType *FTy, + StringRef Name) { + llvm::Function *Fn = + llvm::Function::Create(FTy, llvm::GlobalValue::InternalLinkage, + Name, &CGM.getModule()); + if (!CGM.getContext().getLangOptions().AppleKext) { + // Set the section if needed. + if (const char *Section = + CGM.getContext().getTargetInfo().getStaticInitSectionSpecifier()) + Fn->setSection(Section); + } + + if (!CGM.getLangOptions().Exceptions) + Fn->setDoesNotThrow(); + + return Fn; +} + +void +CodeGenModule::EmitCXXGlobalVarDeclInitFunc(const VarDecl *D, + llvm::GlobalVariable *Addr) { + llvm::FunctionType *FTy + = llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), + false); + + // Create a variable initialization function. + llvm::Function *Fn = + CreateGlobalInitOrDestructFunction(*this, FTy, "__cxx_global_var_init"); + + CodeGenFunction(*this).GenerateCXXGlobalVarDeclInitFunc(Fn, D, Addr); + + if (D->hasAttr<InitPriorityAttr>()) { + unsigned int order = D->getAttr<InitPriorityAttr>()->getPriority(); + OrderGlobalInits Key(order, PrioritizedCXXGlobalInits.size()); + PrioritizedCXXGlobalInits.push_back(std::make_pair(Key, Fn)); + DelayedCXXInitPosition.erase(D); + } + else { + llvm::DenseMap<const Decl *, unsigned>::iterator I = + DelayedCXXInitPosition.find(D); + if (I == DelayedCXXInitPosition.end()) { + CXXGlobalInits.push_back(Fn); + } else { + assert(CXXGlobalInits[I->second] == 0); + CXXGlobalInits[I->second] = Fn; + DelayedCXXInitPosition.erase(I); + } + } +} + +void +CodeGenModule::EmitCXXGlobalInitFunc() { + while (!CXXGlobalInits.empty() && !CXXGlobalInits.back()) + CXXGlobalInits.pop_back(); + + if (CXXGlobalInits.empty() && PrioritizedCXXGlobalInits.empty()) + return; + + llvm::FunctionType *FTy + = llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), + false); + + // Create our global initialization function. + llvm::Function *Fn = + CreateGlobalInitOrDestructFunction(*this, FTy, "_GLOBAL__I_a"); + + if (!PrioritizedCXXGlobalInits.empty()) { + SmallVector<llvm::Constant*, 8> LocalCXXGlobalInits; + llvm::array_pod_sort(PrioritizedCXXGlobalInits.begin(), + PrioritizedCXXGlobalInits.end()); + for (unsigned i = 0; i < PrioritizedCXXGlobalInits.size(); i++) { + llvm::Function *Fn = PrioritizedCXXGlobalInits[i].second; + LocalCXXGlobalInits.push_back(Fn); + } + LocalCXXGlobalInits.append(CXXGlobalInits.begin(), CXXGlobalInits.end()); + CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, + &LocalCXXGlobalInits[0], + LocalCXXGlobalInits.size()); + } + else + CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn, + &CXXGlobalInits[0], + CXXGlobalInits.size()); + AddGlobalCtor(Fn); + CXXGlobalInits.clear(); + PrioritizedCXXGlobalInits.clear(); +} + +void CodeGenModule::EmitCXXGlobalDtorFunc() { + if (CXXGlobalDtors.empty()) + return; + + llvm::FunctionType *FTy + = llvm::FunctionType::get(llvm::Type::getVoidTy(VMContext), + false); + + // Create our global destructor function. + llvm::Function *Fn = + CreateGlobalInitOrDestructFunction(*this, FTy, "_GLOBAL__D_a"); + + CodeGenFunction(*this).GenerateCXXGlobalDtorFunc(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) { + StartFunction(GlobalDecl(), getContext().VoidTy, Fn, + getTypes().getNullaryFunctionInfo(), + FunctionArgList(), SourceLocation()); + + // Use guarded initialization if the global variable is weak. This + // occurs for, e.g., instantiated static data members and + // definitions explicitly marked weak. + if (Addr->getLinkage() == llvm::GlobalValue::WeakODRLinkage || + Addr->getLinkage() == llvm::GlobalValue::WeakAnyLinkage) { + EmitCXXGuardedInit(*D, Addr); + } else { + EmitCXXGlobalVarDeclInit(*D, Addr); + } + + FinishFunction(); +} + +void CodeGenFunction::GenerateCXXGlobalInitFunc(llvm::Function *Fn, + llvm::Constant **Decls, + unsigned NumDecls) { + StartFunction(GlobalDecl(), getContext().VoidTy, Fn, + getTypes().getNullaryFunctionInfo(), + FunctionArgList(), SourceLocation()); + + RunCleanupsScope Scope(*this); + + // When building in Objective-C++ ARC mode, create an autorelease pool + // around the global initializers. + if (getLangOptions().ObjCAutoRefCount && getLangOptions().CPlusPlus) { + llvm::Value *token = EmitObjCAutoreleasePoolPush(); + EmitObjCAutoreleasePoolCleanup(token); + } + + for (unsigned i = 0; i != NumDecls; ++i) + if (Decls[i]) + Builder.CreateCall(Decls[i]); + + Scope.ForceCleanup(); + + FinishFunction(); +} + +void CodeGenFunction::GenerateCXXGlobalDtorFunc(llvm::Function *Fn, + const std::vector<std::pair<llvm::WeakVH, llvm::Constant*> > + &DtorsAndObjects) { + StartFunction(GlobalDecl(), getContext().VoidTy, Fn, + getTypes().getNullaryFunctionInfo(), + FunctionArgList(), SourceLocation()); + + // Emit the dtors, in reverse order from construction. + for (unsigned i = 0, e = DtorsAndObjects.size(); i != e; ++i) { + llvm::Value *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(); +} + +/// generateDestroyHelper - Generates a helper function which, when +/// invoked, destroys the given object. +llvm::Function * +CodeGenFunction::generateDestroyHelper(llvm::Constant *addr, + QualType type, + Destroyer &destroyer, + bool useEHCleanupForArray) { + FunctionArgList args; + ImplicitParamDecl dst(0, SourceLocation(), 0, getContext().VoidPtrTy); + args.push_back(&dst); + + const CGFunctionInfo &FI = + CGM.getTypes().getFunctionInfo(getContext().VoidTy, args, + FunctionType::ExtInfo()); + llvm::FunctionType *FTy = CGM.getTypes().GetFunctionType(FI, false); + llvm::Function *fn = + CreateGlobalInitOrDestructFunction(CGM, FTy, "__cxx_global_array_dtor"); + + StartFunction(GlobalDecl(), getContext().VoidTy, fn, FI, args, + SourceLocation()); + + emitDestroy(addr, type, destroyer, useEHCleanupForArray); + + FinishFunction(); + + return fn; +} + |
