| //===--- CodeGenFunction.cpp - Emit LLVM Code from ASTs for a Function ----===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This coordinates the per-function state used while generating code. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "CodeGenFunction.h" |
| #include "CodeGenModule.h" |
| #include "CGCUDARuntime.h" |
| #include "CGCXXABI.h" |
| #include "CGDebugInfo.h" |
| #include "clang/Basic/TargetInfo.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclCXX.h" |
| #include "clang/AST/StmtCXX.h" |
| #include "clang/Frontend/CodeGenOptions.h" |
| #include "llvm/Intrinsics.h" |
| #include "llvm/MDBuilder.h" |
| #include "llvm/DataLayout.h" |
| using namespace clang; |
| using namespace CodeGen; |
| |
| CodeGenFunction::CodeGenFunction(CodeGenModule &cgm, bool suppressNewContext) |
| : CodeGenTypeCache(cgm), CGM(cgm), |
| Target(CGM.getContext().getTargetInfo()), |
| Builder(cgm.getModule().getContext()), |
| SanitizePerformTypeCheck(CGM.getLangOpts().SanitizeNull | |
| CGM.getLangOpts().SanitizeAlignment | |
| CGM.getLangOpts().SanitizeObjectSize | |
| CGM.getLangOpts().SanitizeVptr), |
| AutoreleaseResult(false), BlockInfo(0), BlockPointer(0), |
| LambdaThisCaptureField(0), NormalCleanupDest(0), NextCleanupDestIndex(1), |
| FirstBlockInfo(0), EHResumeBlock(0), ExceptionSlot(0), EHSelectorSlot(0), |
| DebugInfo(0), DisableDebugInfo(false), DidCallStackSave(false), |
| IndirectBranch(0), SwitchInsn(0), CaseRangeBlock(0), UnreachableBlock(0), |
| CXXABIThisDecl(0), CXXABIThisValue(0), CXXThisValue(0), CXXVTTDecl(0), |
| CXXVTTValue(0), OutermostConditional(0), TerminateLandingPad(0), |
| TerminateHandler(0), TrapBB(0) { |
| if (!suppressNewContext) |
| CGM.getCXXABI().getMangleContext().startNewFunction(); |
| } |
| |
| CodeGenFunction::~CodeGenFunction() { |
| // If there are any unclaimed block infos, go ahead and destroy them |
| // now. This can happen if IR-gen gets clever and skips evaluating |
| // something. |
| if (FirstBlockInfo) |
| destroyBlockInfos(FirstBlockInfo); |
| } |
| |
| |
| llvm::Type *CodeGenFunction::ConvertTypeForMem(QualType T) { |
| return CGM.getTypes().ConvertTypeForMem(T); |
| } |
| |
| llvm::Type *CodeGenFunction::ConvertType(QualType T) { |
| return CGM.getTypes().ConvertType(T); |
| } |
| |
| bool CodeGenFunction::hasAggregateLLVMType(QualType type) { |
| switch (type.getCanonicalType()->getTypeClass()) { |
| #define TYPE(name, parent) |
| #define ABSTRACT_TYPE(name, parent) |
| #define NON_CANONICAL_TYPE(name, parent) case Type::name: |
| #define DEPENDENT_TYPE(name, parent) case Type::name: |
| #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(name, parent) case Type::name: |
| #include "clang/AST/TypeNodes.def" |
| llvm_unreachable("non-canonical or dependent type in IR-generation"); |
| |
| case Type::Builtin: |
| case Type::Pointer: |
| case Type::BlockPointer: |
| case Type::LValueReference: |
| case Type::RValueReference: |
| case Type::MemberPointer: |
| case Type::Vector: |
| case Type::ExtVector: |
| case Type::FunctionProto: |
| case Type::FunctionNoProto: |
| case Type::Enum: |
| case Type::ObjCObjectPointer: |
| return false; |
| |
| // Complexes, arrays, records, and Objective-C objects. |
| case Type::Complex: |
| case Type::ConstantArray: |
| case Type::IncompleteArray: |
| case Type::VariableArray: |
| case Type::Record: |
| case Type::ObjCObject: |
| case Type::ObjCInterface: |
| return true; |
| |
| // In IRGen, atomic types are just the underlying type |
| case Type::Atomic: |
| return hasAggregateLLVMType(type->getAs<AtomicType>()->getValueType()); |
| } |
| llvm_unreachable("unknown type kind!"); |
| } |
| |
| void CodeGenFunction::EmitReturnBlock() { |
| // For cleanliness, we try to avoid emitting the return block for |
| // simple cases. |
| llvm::BasicBlock *CurBB = Builder.GetInsertBlock(); |
| |
| if (CurBB) { |
| assert(!CurBB->getTerminator() && "Unexpected terminated block."); |
| |
| // We have a valid insert point, reuse it if it is empty or there are no |
| // explicit jumps to the return block. |
| if (CurBB->empty() || ReturnBlock.getBlock()->use_empty()) { |
| ReturnBlock.getBlock()->replaceAllUsesWith(CurBB); |
| delete ReturnBlock.getBlock(); |
| } else |
| EmitBlock(ReturnBlock.getBlock()); |
| return; |
| } |
| |
| // Otherwise, if the return block is the target of a single direct |
| // branch then we can just put the code in that block instead. This |
| // cleans up functions which started with a unified return block. |
| if (ReturnBlock.getBlock()->hasOneUse()) { |
| llvm::BranchInst *BI = |
| dyn_cast<llvm::BranchInst>(*ReturnBlock.getBlock()->use_begin()); |
| if (BI && BI->isUnconditional() && |
| BI->getSuccessor(0) == ReturnBlock.getBlock()) { |
| // Reset insertion point, including debug location, and delete the branch. |
| Builder.SetCurrentDebugLocation(BI->getDebugLoc()); |
| Builder.SetInsertPoint(BI->getParent()); |
| BI->eraseFromParent(); |
| delete ReturnBlock.getBlock(); |
| return; |
| } |
| } |
| |
| // FIXME: We are at an unreachable point, there is no reason to emit the block |
| // unless it has uses. However, we still need a place to put the debug |
| // region.end for now. |
| |
| EmitBlock(ReturnBlock.getBlock()); |
| } |
| |
| static void EmitIfUsed(CodeGenFunction &CGF, llvm::BasicBlock *BB) { |
| if (!BB) return; |
| if (!BB->use_empty()) |
| return CGF.CurFn->getBasicBlockList().push_back(BB); |
| delete BB; |
| } |
| |
| void CodeGenFunction::FinishFunction(SourceLocation EndLoc) { |
| assert(BreakContinueStack.empty() && |
| "mismatched push/pop in break/continue stack!"); |
| |
| // Pop any cleanups that might have been associated with the |
| // parameters. Do this in whatever block we're currently in; it's |
| // important to do this before we enter the return block or return |
| // edges will be *really* confused. |
| if (EHStack.stable_begin() != PrologueCleanupDepth) |
| PopCleanupBlocks(PrologueCleanupDepth); |
| |
| // Emit function epilog (to return). |
| EmitReturnBlock(); |
| |
| if (ShouldInstrumentFunction()) |
| EmitFunctionInstrumentation("__cyg_profile_func_exit"); |
| |
| // Emit debug descriptor for function end. |
| if (CGDebugInfo *DI = getDebugInfo()) { |
| DI->setLocation(EndLoc); |
| DI->EmitFunctionEnd(Builder); |
| } |
| |
| EmitFunctionEpilog(*CurFnInfo); |
| EmitEndEHSpec(CurCodeDecl); |
| |
| assert(EHStack.empty() && |
| "did not remove all scopes from cleanup stack!"); |
| |
| // If someone did an indirect goto, emit the indirect goto block at the end of |
| // the function. |
| if (IndirectBranch) { |
| EmitBlock(IndirectBranch->getParent()); |
| Builder.ClearInsertionPoint(); |
| } |
| |
| // Remove the AllocaInsertPt instruction, which is just a convenience for us. |
| llvm::Instruction *Ptr = AllocaInsertPt; |
| AllocaInsertPt = 0; |
| Ptr->eraseFromParent(); |
| |
| // If someone took the address of a label but never did an indirect goto, we |
| // made a zero entry PHI node, which is illegal, zap it now. |
| if (IndirectBranch) { |
| llvm::PHINode *PN = cast<llvm::PHINode>(IndirectBranch->getAddress()); |
| if (PN->getNumIncomingValues() == 0) { |
| PN->replaceAllUsesWith(llvm::UndefValue::get(PN->getType())); |
| PN->eraseFromParent(); |
| } |
| } |
| |
| EmitIfUsed(*this, EHResumeBlock); |
| EmitIfUsed(*this, TerminateLandingPad); |
| EmitIfUsed(*this, TerminateHandler); |
| EmitIfUsed(*this, UnreachableBlock); |
| |
| if (CGM.getCodeGenOpts().EmitDeclMetadata) |
| EmitDeclMetadata(); |
| } |
| |
| /// ShouldInstrumentFunction - Return true if the current function should be |
| /// instrumented with __cyg_profile_func_* calls |
| bool CodeGenFunction::ShouldInstrumentFunction() { |
| if (!CGM.getCodeGenOpts().InstrumentFunctions) |
| return false; |
| if (!CurFuncDecl || CurFuncDecl->hasAttr<NoInstrumentFunctionAttr>()) |
| return false; |
| return true; |
| } |
| |
| /// EmitFunctionInstrumentation - Emit LLVM code to call the specified |
| /// instrumentation function with the current function and the call site, if |
| /// function instrumentation is enabled. |
| void CodeGenFunction::EmitFunctionInstrumentation(const char *Fn) { |
| // void __cyg_profile_func_{enter,exit} (void *this_fn, void *call_site); |
| llvm::PointerType *PointerTy = Int8PtrTy; |
| llvm::Type *ProfileFuncArgs[] = { PointerTy, PointerTy }; |
| llvm::FunctionType *FunctionTy = |
| llvm::FunctionType::get(VoidTy, ProfileFuncArgs, false); |
| |
| llvm::Constant *F = CGM.CreateRuntimeFunction(FunctionTy, Fn); |
| llvm::CallInst *CallSite = Builder.CreateCall( |
| CGM.getIntrinsic(llvm::Intrinsic::returnaddress), |
| llvm::ConstantInt::get(Int32Ty, 0), |
| "callsite"); |
| |
| Builder.CreateCall2(F, |
| llvm::ConstantExpr::getBitCast(CurFn, PointerTy), |
| CallSite); |
| } |
| |
| void CodeGenFunction::EmitMCountInstrumentation() { |
| llvm::FunctionType *FTy = llvm::FunctionType::get(VoidTy, false); |
| |
| llvm::Constant *MCountFn = CGM.CreateRuntimeFunction(FTy, |
| Target.getMCountName()); |
| Builder.CreateCall(MCountFn); |
| } |
| |
| // OpenCL v1.2 s5.6.4.6 allows the compiler to store kernel argument |
| // information in the program executable. The argument information stored |
| // includes the argument name, its type, the address and access qualifiers used. |
| // FIXME: Add type, address, and access qualifiers. |
| static void GenOpenCLArgMetadata(const FunctionDecl *FD, llvm::Function *Fn, |
| CodeGenModule &CGM,llvm::LLVMContext &Context, |
| llvm::SmallVector <llvm::Value*, 5> &kernelMDArgs) { |
| |
| // Create MDNodes that represents the kernel arg metadata. |
| // Each MDNode is a list in the form of "key", N number of values which is |
| // the same number of values as their are kernel arguments. |
| |
| // MDNode for the kernel argument names. |
| SmallVector<llvm::Value*, 8> argNames; |
| argNames.push_back(llvm::MDString::get(Context, "kernel_arg_name")); |
| |
| for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) { |
| const ParmVarDecl *parm = FD->getParamDecl(i); |
| |
| // Get argument name. |
| argNames.push_back(llvm::MDString::get(Context, parm->getName())); |
| |
| } |
| // Add MDNode to the list of all metadata. |
| kernelMDArgs.push_back(llvm::MDNode::get(Context, argNames)); |
| } |
| |
| void CodeGenFunction::EmitOpenCLKernelMetadata(const FunctionDecl *FD, |
| llvm::Function *Fn) |
| { |
| if (!FD->hasAttr<OpenCLKernelAttr>()) |
| return; |
| |
| llvm::LLVMContext &Context = getLLVMContext(); |
| |
| llvm::SmallVector <llvm::Value*, 5> kernelMDArgs; |
| kernelMDArgs.push_back(Fn); |
| |
| if (CGM.getCodeGenOpts().EmitOpenCLArgMetadata) |
| GenOpenCLArgMetadata(FD, Fn, CGM, Context, kernelMDArgs); |
| |
| if (FD->hasAttr<WorkGroupSizeHintAttr>()) { |
| WorkGroupSizeHintAttr *attr = FD->getAttr<WorkGroupSizeHintAttr>(); |
| llvm::Value *attrMDArgs[] = { |
| llvm::MDString::get(Context, "work_group_size_hint"), |
| Builder.getInt32(attr->getXDim()), |
| Builder.getInt32(attr->getYDim()), |
| Builder.getInt32(attr->getZDim()) |
| }; |
| kernelMDArgs.push_back(llvm::MDNode::get(Context, attrMDArgs)); |
| } |
| |
| if (FD->hasAttr<ReqdWorkGroupSizeAttr>()) { |
| ReqdWorkGroupSizeAttr *attr = FD->getAttr<ReqdWorkGroupSizeAttr>(); |
| llvm::Value *attrMDArgs[] = { |
| llvm::MDString::get(Context, "reqd_work_group_size"), |
| Builder.getInt32(attr->getXDim()), |
| Builder.getInt32(attr->getYDim()), |
| Builder.getInt32(attr->getZDim()) |
| }; |
| kernelMDArgs.push_back(llvm::MDNode::get(Context, attrMDArgs)); |
| } |
| |
| llvm::MDNode *kernelMDNode = llvm::MDNode::get(Context, kernelMDArgs); |
| llvm::NamedMDNode *OpenCLKernelMetadata = |
| CGM.getModule().getOrInsertNamedMetadata("opencl.kernels"); |
| OpenCLKernelMetadata->addOperand(kernelMDNode); |
| } |
| |
| void CodeGenFunction::StartFunction(GlobalDecl GD, QualType RetTy, |
| llvm::Function *Fn, |
| const CGFunctionInfo &FnInfo, |
| const FunctionArgList &Args, |
| SourceLocation StartLoc) { |
| const Decl *D = GD.getDecl(); |
| |
| DidCallStackSave = false; |
| CurCodeDecl = CurFuncDecl = D; |
| FnRetTy = RetTy; |
| CurFn = Fn; |
| CurFnInfo = &FnInfo; |
| assert(CurFn->isDeclaration() && "Function already has body?"); |
| |
| // Pass inline keyword to optimizer if it appears explicitly on any |
| // declaration. |
| if (!CGM.getCodeGenOpts().NoInline) |
| if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D)) |
| for (FunctionDecl::redecl_iterator RI = FD->redecls_begin(), |
| RE = FD->redecls_end(); RI != RE; ++RI) |
| if (RI->isInlineSpecified()) { |
| Fn->addFnAttr(llvm::Attributes::InlineHint); |
| break; |
| } |
| |
| if (getLangOpts().OpenCL) { |
| // Add metadata for a kernel function. |
| if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(D)) |
| EmitOpenCLKernelMetadata(FD, Fn); |
| } |
| |
| llvm::BasicBlock *EntryBB = createBasicBlock("entry", CurFn); |
| |
| // Create a marker to make it easy to insert allocas into the entryblock |
| // later. Don't create this with the builder, because we don't want it |
| // folded. |
| llvm::Value *Undef = llvm::UndefValue::get(Int32Ty); |
| AllocaInsertPt = new llvm::BitCastInst(Undef, Int32Ty, "", EntryBB); |
| if (Builder.isNamePreserving()) |
| AllocaInsertPt->setName("allocapt"); |
| |
| ReturnBlock = getJumpDestInCurrentScope("return"); |
| |
| Builder.SetInsertPoint(EntryBB); |
| |
| // Emit subprogram debug descriptor. |
| if (CGDebugInfo *DI = getDebugInfo()) { |
| unsigned NumArgs = 0; |
| QualType *ArgsArray = new QualType[Args.size()]; |
| for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end(); |
| i != e; ++i) { |
| ArgsArray[NumArgs++] = (*i)->getType(); |
| } |
| |
| QualType FnType = |
| getContext().getFunctionType(RetTy, ArgsArray, NumArgs, |
| FunctionProtoType::ExtProtoInfo()); |
| |
| delete[] ArgsArray; |
| |
| DI->setLocation(StartLoc); |
| DI->EmitFunctionStart(GD, FnType, CurFn, Builder); |
| } |
| |
| if (ShouldInstrumentFunction()) |
| EmitFunctionInstrumentation("__cyg_profile_func_enter"); |
| |
| if (CGM.getCodeGenOpts().InstrumentForProfiling) |
| EmitMCountInstrumentation(); |
| |
| if (RetTy->isVoidType()) { |
| // Void type; nothing to return. |
| ReturnValue = 0; |
| } else if (CurFnInfo->getReturnInfo().getKind() == ABIArgInfo::Indirect && |
| hasAggregateLLVMType(CurFnInfo->getReturnType())) { |
| // Indirect aggregate return; emit returned value directly into sret slot. |
| // This reduces code size, and affects correctness in C++. |
| ReturnValue = CurFn->arg_begin(); |
| } else { |
| ReturnValue = CreateIRTemp(RetTy, "retval"); |
| |
| // Tell the epilog emitter to autorelease the result. We do this |
| // now so that various specialized functions can suppress it |
| // during their IR-generation. |
| if (getLangOpts().ObjCAutoRefCount && |
| !CurFnInfo->isReturnsRetained() && |
| RetTy->isObjCRetainableType()) |
| AutoreleaseResult = true; |
| } |
| |
| EmitStartEHSpec(CurCodeDecl); |
| |
| PrologueCleanupDepth = EHStack.stable_begin(); |
| EmitFunctionProlog(*CurFnInfo, CurFn, Args); |
| |
| if (D && isa<CXXMethodDecl>(D) && cast<CXXMethodDecl>(D)->isInstance()) { |
| CGM.getCXXABI().EmitInstanceFunctionProlog(*this); |
| const CXXMethodDecl *MD = cast<CXXMethodDecl>(D); |
| if (MD->getParent()->isLambda() && |
| MD->getOverloadedOperator() == OO_Call) { |
| // We're in a lambda; figure out the captures. |
| MD->getParent()->getCaptureFields(LambdaCaptureFields, |
| LambdaThisCaptureField); |
| if (LambdaThisCaptureField) { |
| // If this lambda captures this, load it. |
| QualType LambdaTagType = |
| getContext().getTagDeclType(LambdaThisCaptureField->getParent()); |
| LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, |
| LambdaTagType); |
| LValue ThisLValue = EmitLValueForField(LambdaLV, |
| LambdaThisCaptureField); |
| CXXThisValue = EmitLoadOfLValue(ThisLValue).getScalarVal(); |
| } |
| } else { |
| // Not in a lambda; just use 'this' from the method. |
| // FIXME: Should we generate a new load for each use of 'this'? The |
| // fast register allocator would be happier... |
| CXXThisValue = CXXABIThisValue; |
| } |
| } |
| |
| // If any of the arguments have a variably modified type, make sure to |
| // emit the type size. |
| for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end(); |
| i != e; ++i) { |
| const VarDecl *VD = *i; |
| |
| // Dig out the type as written from ParmVarDecls; it's unclear whether |
| // the standard (C99 6.9.1p10) requires this, but we're following the |
| // precedent set by gcc. |
| QualType Ty; |
| if (const ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(VD)) |
| Ty = PVD->getOriginalType(); |
| else |
| Ty = VD->getType(); |
| |
| if (Ty->isVariablyModifiedType()) |
| EmitVariablyModifiedType(Ty); |
| } |
| // Emit a location at the end of the prologue. |
| if (CGDebugInfo *DI = getDebugInfo()) |
| DI->EmitLocation(Builder, StartLoc); |
| } |
| |
| void CodeGenFunction::EmitFunctionBody(FunctionArgList &Args) { |
| const FunctionDecl *FD = cast<FunctionDecl>(CurGD.getDecl()); |
| assert(FD->getBody()); |
| EmitStmt(FD->getBody()); |
| } |
| |
| /// Tries to mark the given function nounwind based on the |
| /// non-existence of any throwing calls within it. We believe this is |
| /// lightweight enough to do at -O0. |
| static void TryMarkNoThrow(llvm::Function *F) { |
| // LLVM treats 'nounwind' on a function as part of the type, so we |
| // can't do this on functions that can be overwritten. |
| if (F->mayBeOverridden()) return; |
| |
| for (llvm::Function::iterator FI = F->begin(), FE = F->end(); FI != FE; ++FI) |
| for (llvm::BasicBlock::iterator |
| BI = FI->begin(), BE = FI->end(); BI != BE; ++BI) |
| if (llvm::CallInst *Call = dyn_cast<llvm::CallInst>(&*BI)) { |
| if (!Call->doesNotThrow()) |
| return; |
| } else if (isa<llvm::ResumeInst>(&*BI)) { |
| return; |
| } |
| F->setDoesNotThrow(); |
| } |
| |
| void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn, |
| const CGFunctionInfo &FnInfo) { |
| const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); |
| |
| // Check if we should generate debug info for this function. |
| if (!FD->hasAttr<NoDebugAttr>()) |
| maybeInitializeDebugInfo(); |
| |
| FunctionArgList Args; |
| QualType ResTy = FD->getResultType(); |
| |
| CurGD = GD; |
| if (isa<CXXMethodDecl>(FD) && cast<CXXMethodDecl>(FD)->isInstance()) |
| CGM.getCXXABI().BuildInstanceFunctionParams(*this, ResTy, Args); |
| |
| for (unsigned i = 0, e = FD->getNumParams(); i != e; ++i) |
| Args.push_back(FD->getParamDecl(i)); |
| |
| SourceRange BodyRange; |
| if (Stmt *Body = FD->getBody()) BodyRange = Body->getSourceRange(); |
| |
| // Emit the standard function prologue. |
| StartFunction(GD, ResTy, Fn, FnInfo, Args, BodyRange.getBegin()); |
| |
| // Generate the body of the function. |
| if (isa<CXXDestructorDecl>(FD)) |
| EmitDestructorBody(Args); |
| else if (isa<CXXConstructorDecl>(FD)) |
| EmitConstructorBody(Args); |
| else if (getLangOpts().CUDA && |
| !CGM.getCodeGenOpts().CUDAIsDevice && |
| FD->hasAttr<CUDAGlobalAttr>()) |
| CGM.getCUDARuntime().EmitDeviceStubBody(*this, Args); |
| else if (isa<CXXConversionDecl>(FD) && |
| cast<CXXConversionDecl>(FD)->isLambdaToBlockPointerConversion()) { |
| // The lambda conversion to block pointer is special; the semantics can't be |
| // expressed in the AST, so IRGen needs to special-case it. |
| EmitLambdaToBlockPointerBody(Args); |
| } else if (isa<CXXMethodDecl>(FD) && |
| cast<CXXMethodDecl>(FD)->isLambdaStaticInvoker()) { |
| // The lambda "__invoke" function is special, because it forwards or |
| // clones the body of the function call operator (but is actually static). |
| EmitLambdaStaticInvokeFunction(cast<CXXMethodDecl>(FD)); |
| } |
| else |
| EmitFunctionBody(Args); |
| |
| // C++11 [stmt.return]p2: |
| // Flowing off the end of a function [...] results in undefined behavior in |
| // a value-returning function. |
| // C11 6.9.1p12: |
| // If the '}' that terminates a function is reached, and the value of the |
| // function call is used by the caller, the behavior is undefined. |
| if (getLangOpts().CPlusPlus && !FD->hasImplicitReturnZero() && |
| !FD->getResultType()->isVoidType() && Builder.GetInsertBlock()) { |
| if (getLangOpts().SanitizeReturn) |
| EmitCheck(Builder.getFalse(), "missing_return", |
| EmitCheckSourceLocation(FD->getLocation()), |
| llvm::ArrayRef<llvm::Value*>()); |
| else if (CGM.getCodeGenOpts().OptimizationLevel == 0) |
| Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::trap)); |
| Builder.CreateUnreachable(); |
| Builder.ClearInsertionPoint(); |
| } |
| |
| // Emit the standard function epilogue. |
| FinishFunction(BodyRange.getEnd()); |
| |
| // If we haven't marked the function nothrow through other means, do |
| // a quick pass now to see if we can. |
| if (!CurFn->doesNotThrow()) |
| TryMarkNoThrow(CurFn); |
| } |
| |
| /// ContainsLabel - Return true if the statement contains a label in it. If |
| /// this statement is not executed normally, it not containing a label means |
| /// that we can just remove the code. |
| bool CodeGenFunction::ContainsLabel(const Stmt *S, bool IgnoreCaseStmts) { |
| // Null statement, not a label! |
| if (S == 0) return false; |
| |
| // If this is a label, we have to emit the code, consider something like: |
| // if (0) { ... foo: bar(); } goto foo; |
| // |
| // TODO: If anyone cared, we could track __label__'s, since we know that you |
| // can't jump to one from outside their declared region. |
| if (isa<LabelStmt>(S)) |
| return true; |
| |
| // If this is a case/default statement, and we haven't seen a switch, we have |
| // to emit the code. |
| if (isa<SwitchCase>(S) && !IgnoreCaseStmts) |
| return true; |
| |
| // If this is a switch statement, we want to ignore cases below it. |
| if (isa<SwitchStmt>(S)) |
| IgnoreCaseStmts = true; |
| |
| // Scan subexpressions for verboten labels. |
| for (Stmt::const_child_range I = S->children(); I; ++I) |
| if (ContainsLabel(*I, IgnoreCaseStmts)) |
| return true; |
| |
| return false; |
| } |
| |
| /// containsBreak - Return true if the statement contains a break out of it. |
| /// If the statement (recursively) contains a switch or loop with a break |
| /// inside of it, this is fine. |
| bool CodeGenFunction::containsBreak(const Stmt *S) { |
| // Null statement, not a label! |
| if (S == 0) return false; |
| |
| // If this is a switch or loop that defines its own break scope, then we can |
| // include it and anything inside of it. |
| if (isa<SwitchStmt>(S) || isa<WhileStmt>(S) || isa<DoStmt>(S) || |
| isa<ForStmt>(S)) |
| return false; |
| |
| if (isa<BreakStmt>(S)) |
| return true; |
| |
| // Scan subexpressions for verboten breaks. |
| for (Stmt::const_child_range I = S->children(); I; ++I) |
| if (containsBreak(*I)) |
| return true; |
| |
| return false; |
| } |
| |
| |
| /// ConstantFoldsToSimpleInteger - If the specified expression does not fold |
| /// to a constant, or if it does but contains a label, return false. If it |
| /// constant folds return true and set the boolean result in Result. |
| bool CodeGenFunction::ConstantFoldsToSimpleInteger(const Expr *Cond, |
| bool &ResultBool) { |
| llvm::APSInt ResultInt; |
| if (!ConstantFoldsToSimpleInteger(Cond, ResultInt)) |
| return false; |
| |
| ResultBool = ResultInt.getBoolValue(); |
| return true; |
| } |
| |
| /// ConstantFoldsToSimpleInteger - If the specified expression does not fold |
| /// to a constant, or if it does but contains a label, return false. If it |
| /// constant folds return true and set the folded value. |
| bool CodeGenFunction:: |
| ConstantFoldsToSimpleInteger(const Expr *Cond, llvm::APSInt &ResultInt) { |
| // FIXME: Rename and handle conversion of other evaluatable things |
| // to bool. |
| llvm::APSInt Int; |
| if (!Cond->EvaluateAsInt(Int, getContext())) |
| return false; // Not foldable, not integer or not fully evaluatable. |
| |
| if (CodeGenFunction::ContainsLabel(Cond)) |
| return false; // Contains a label. |
| |
| ResultInt = Int; |
| return true; |
| } |
| |
| |
| |
| /// EmitBranchOnBoolExpr - Emit a branch on a boolean condition (e.g. for an if |
| /// statement) to the specified blocks. Based on the condition, this might try |
| /// to simplify the codegen of the conditional based on the branch. |
| /// |
| void CodeGenFunction::EmitBranchOnBoolExpr(const Expr *Cond, |
| llvm::BasicBlock *TrueBlock, |
| llvm::BasicBlock *FalseBlock) { |
| Cond = Cond->IgnoreParens(); |
| |
| if (const BinaryOperator *CondBOp = dyn_cast<BinaryOperator>(Cond)) { |
| // Handle X && Y in a condition. |
| if (CondBOp->getOpcode() == BO_LAnd) { |
| // If we have "1 && X", simplify the code. "0 && X" would have constant |
| // folded if the case was simple enough. |
| bool ConstantBool = false; |
| if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) && |
| ConstantBool) { |
| // br(1 && X) -> br(X). |
| return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock); |
| } |
| |
| // If we have "X && 1", simplify the code to use an uncond branch. |
| // "X && 0" would have been constant folded to 0. |
| if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) && |
| ConstantBool) { |
| // br(X && 1) -> br(X). |
| return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock); |
| } |
| |
| // Emit the LHS as a conditional. If the LHS conditional is false, we |
| // want to jump to the FalseBlock. |
| llvm::BasicBlock *LHSTrue = createBasicBlock("land.lhs.true"); |
| |
| ConditionalEvaluation eval(*this); |
| EmitBranchOnBoolExpr(CondBOp->getLHS(), LHSTrue, FalseBlock); |
| EmitBlock(LHSTrue); |
| |
| // Any temporaries created here are conditional. |
| eval.begin(*this); |
| EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock); |
| eval.end(*this); |
| |
| return; |
| } |
| |
| if (CondBOp->getOpcode() == BO_LOr) { |
| // If we have "0 || X", simplify the code. "1 || X" would have constant |
| // folded if the case was simple enough. |
| bool ConstantBool = false; |
| if (ConstantFoldsToSimpleInteger(CondBOp->getLHS(), ConstantBool) && |
| !ConstantBool) { |
| // br(0 || X) -> br(X). |
| return EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock); |
| } |
| |
| // If we have "X || 0", simplify the code to use an uncond branch. |
| // "X || 1" would have been constant folded to 1. |
| if (ConstantFoldsToSimpleInteger(CondBOp->getRHS(), ConstantBool) && |
| !ConstantBool) { |
| // br(X || 0) -> br(X). |
| return EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, FalseBlock); |
| } |
| |
| // Emit the LHS as a conditional. If the LHS conditional is true, we |
| // want to jump to the TrueBlock. |
| llvm::BasicBlock *LHSFalse = createBasicBlock("lor.lhs.false"); |
| |
| ConditionalEvaluation eval(*this); |
| EmitBranchOnBoolExpr(CondBOp->getLHS(), TrueBlock, LHSFalse); |
| EmitBlock(LHSFalse); |
| |
| // Any temporaries created here are conditional. |
| eval.begin(*this); |
| EmitBranchOnBoolExpr(CondBOp->getRHS(), TrueBlock, FalseBlock); |
| eval.end(*this); |
| |
| return; |
| } |
| } |
| |
| if (const UnaryOperator *CondUOp = dyn_cast<UnaryOperator>(Cond)) { |
| // br(!x, t, f) -> br(x, f, t) |
| if (CondUOp->getOpcode() == UO_LNot) |
| return EmitBranchOnBoolExpr(CondUOp->getSubExpr(), FalseBlock, TrueBlock); |
| } |
| |
| if (const ConditionalOperator *CondOp = dyn_cast<ConditionalOperator>(Cond)) { |
| // br(c ? x : y, t, f) -> br(c, br(x, t, f), br(y, t, f)) |
| llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true"); |
| llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false"); |
| |
| ConditionalEvaluation cond(*this); |
| EmitBranchOnBoolExpr(CondOp->getCond(), LHSBlock, RHSBlock); |
| |
| cond.begin(*this); |
| EmitBlock(LHSBlock); |
| EmitBranchOnBoolExpr(CondOp->getLHS(), TrueBlock, FalseBlock); |
| cond.end(*this); |
| |
| cond.begin(*this); |
| EmitBlock(RHSBlock); |
| EmitBranchOnBoolExpr(CondOp->getRHS(), TrueBlock, FalseBlock); |
| cond.end(*this); |
| |
| return; |
| } |
| |
| // Emit the code with the fully general case. |
| llvm::Value *CondV = EvaluateExprAsBool(Cond); |
| Builder.CreateCondBr(CondV, TrueBlock, FalseBlock); |
| } |
| |
| /// ErrorUnsupported - Print out an error that codegen doesn't support the |
| /// specified stmt yet. |
| void CodeGenFunction::ErrorUnsupported(const Stmt *S, const char *Type, |
| bool OmitOnError) { |
| CGM.ErrorUnsupported(S, Type, OmitOnError); |
| } |
| |
| /// emitNonZeroVLAInit - Emit the "zero" initialization of a |
| /// variable-length array whose elements have a non-zero bit-pattern. |
| /// |
| /// \param baseType the inner-most element type of the array |
| /// \param src - a char* pointing to the bit-pattern for a single |
| /// base element of the array |
| /// \param sizeInChars - the total size of the VLA, in chars |
| static void emitNonZeroVLAInit(CodeGenFunction &CGF, QualType baseType, |
| llvm::Value *dest, llvm::Value *src, |
| llvm::Value *sizeInChars) { |
| std::pair<CharUnits,CharUnits> baseSizeAndAlign |
| = CGF.getContext().getTypeInfoInChars(baseType); |
| |
| CGBuilderTy &Builder = CGF.Builder; |
| |
| llvm::Value *baseSizeInChars |
| = llvm::ConstantInt::get(CGF.IntPtrTy, baseSizeAndAlign.first.getQuantity()); |
| |
| llvm::Type *i8p = Builder.getInt8PtrTy(); |
| |
| llvm::Value *begin = Builder.CreateBitCast(dest, i8p, "vla.begin"); |
| llvm::Value *end = Builder.CreateInBoundsGEP(dest, sizeInChars, "vla.end"); |
| |
| llvm::BasicBlock *originBB = CGF.Builder.GetInsertBlock(); |
| llvm::BasicBlock *loopBB = CGF.createBasicBlock("vla-init.loop"); |
| llvm::BasicBlock *contBB = CGF.createBasicBlock("vla-init.cont"); |
| |
| // Make a loop over the VLA. C99 guarantees that the VLA element |
| // count must be nonzero. |
| CGF.EmitBlock(loopBB); |
| |
| llvm::PHINode *cur = Builder.CreatePHI(i8p, 2, "vla.cur"); |
| cur->addIncoming(begin, originBB); |
| |
| // memcpy the individual element bit-pattern. |
| Builder.CreateMemCpy(cur, src, baseSizeInChars, |
| baseSizeAndAlign.second.getQuantity(), |
| /*volatile*/ false); |
| |
| // Go to the next element. |
| llvm::Value *next = Builder.CreateConstInBoundsGEP1_32(cur, 1, "vla.next"); |
| |
| // Leave if that's the end of the VLA. |
| llvm::Value *done = Builder.CreateICmpEQ(next, end, "vla-init.isdone"); |
| Builder.CreateCondBr(done, contBB, loopBB); |
| cur->addIncoming(next, loopBB); |
| |
| CGF.EmitBlock(contBB); |
| } |
| |
| void |
| CodeGenFunction::EmitNullInitialization(llvm::Value *DestPtr, QualType Ty) { |
| // Ignore empty classes in C++. |
| if (getLangOpts().CPlusPlus) { |
| if (const RecordType *RT = Ty->getAs<RecordType>()) { |
| if (cast<CXXRecordDecl>(RT->getDecl())->isEmpty()) |
| return; |
| } |
| } |
| |
| // Cast the dest ptr to the appropriate i8 pointer type. |
| unsigned DestAS = |
| cast<llvm::PointerType>(DestPtr->getType())->getAddressSpace(); |
| llvm::Type *BP = Builder.getInt8PtrTy(DestAS); |
| if (DestPtr->getType() != BP) |
| DestPtr = Builder.CreateBitCast(DestPtr, BP); |
| |
| // Get size and alignment info for this aggregate. |
| std::pair<CharUnits, CharUnits> TypeInfo = |
| getContext().getTypeInfoInChars(Ty); |
| CharUnits Size = TypeInfo.first; |
| CharUnits Align = TypeInfo.second; |
| |
| llvm::Value *SizeVal; |
| const VariableArrayType *vla; |
| |
| // Don't bother emitting a zero-byte memset. |
| if (Size.isZero()) { |
| // But note that getTypeInfo returns 0 for a VLA. |
| if (const VariableArrayType *vlaType = |
| dyn_cast_or_null<VariableArrayType>( |
| getContext().getAsArrayType(Ty))) { |
| QualType eltType; |
| llvm::Value *numElts; |
| llvm::tie(numElts, eltType) = getVLASize(vlaType); |
| |
| SizeVal = numElts; |
| CharUnits eltSize = getContext().getTypeSizeInChars(eltType); |
| if (!eltSize.isOne()) |
| SizeVal = Builder.CreateNUWMul(SizeVal, CGM.getSize(eltSize)); |
| vla = vlaType; |
| } else { |
| return; |
| } |
| } else { |
| SizeVal = CGM.getSize(Size); |
| vla = 0; |
| } |
| |
| // If the type contains a pointer to data member we can't memset it to zero. |
| // Instead, create a null constant and copy it to the destination. |
| // TODO: there are other patterns besides zero that we can usefully memset, |
| // like -1, which happens to be the pattern used by member-pointers. |
| if (!CGM.getTypes().isZeroInitializable(Ty)) { |
| // For a VLA, emit a single element, then splat that over the VLA. |
| if (vla) Ty = getContext().getBaseElementType(vla); |
| |
| llvm::Constant *NullConstant = CGM.EmitNullConstant(Ty); |
| |
| llvm::GlobalVariable *NullVariable = |
| new llvm::GlobalVariable(CGM.getModule(), NullConstant->getType(), |
| /*isConstant=*/true, |
| llvm::GlobalVariable::PrivateLinkage, |
| NullConstant, Twine()); |
| llvm::Value *SrcPtr = |
| Builder.CreateBitCast(NullVariable, Builder.getInt8PtrTy()); |
| |
| if (vla) return emitNonZeroVLAInit(*this, Ty, DestPtr, SrcPtr, SizeVal); |
| |
| // Get and call the appropriate llvm.memcpy overload. |
| Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, Align.getQuantity(), false); |
| return; |
| } |
| |
| // Otherwise, just memset the whole thing to zero. This is legal |
| // because in LLVM, all default initializers (other than the ones we just |
| // handled above) are guaranteed to have a bit pattern of all zeros. |
| Builder.CreateMemSet(DestPtr, Builder.getInt8(0), SizeVal, |
| Align.getQuantity(), false); |
| } |
| |
| llvm::BlockAddress *CodeGenFunction::GetAddrOfLabel(const LabelDecl *L) { |
| // Make sure that there is a block for the indirect goto. |
| if (IndirectBranch == 0) |
| GetIndirectGotoBlock(); |
| |
| llvm::BasicBlock *BB = getJumpDestForLabel(L).getBlock(); |
| |
| // Make sure the indirect branch includes all of the address-taken blocks. |
| IndirectBranch->addDestination(BB); |
| return llvm::BlockAddress::get(CurFn, BB); |
| } |
| |
| llvm::BasicBlock *CodeGenFunction::GetIndirectGotoBlock() { |
| // If we already made the indirect branch for indirect goto, return its block. |
| if (IndirectBranch) return IndirectBranch->getParent(); |
| |
| CGBuilderTy TmpBuilder(createBasicBlock("indirectgoto")); |
| |
| // Create the PHI node that indirect gotos will add entries to. |
| llvm::Value *DestVal = TmpBuilder.CreatePHI(Int8PtrTy, 0, |
| "indirect.goto.dest"); |
| |
| // Create the indirect branch instruction. |
| IndirectBranch = TmpBuilder.CreateIndirectBr(DestVal); |
| return IndirectBranch->getParent(); |
| } |
| |
| /// Computes the length of an array in elements, as well as the base |
| /// element type and a properly-typed first element pointer. |
| llvm::Value *CodeGenFunction::emitArrayLength(const ArrayType *origArrayType, |
| QualType &baseType, |
| llvm::Value *&addr) { |
| const ArrayType *arrayType = origArrayType; |
| |
| // If it's a VLA, we have to load the stored size. Note that |
| // this is the size of the VLA in bytes, not its size in elements. |
| llvm::Value *numVLAElements = 0; |
| if (isa<VariableArrayType>(arrayType)) { |
| numVLAElements = getVLASize(cast<VariableArrayType>(arrayType)).first; |
| |
| // Walk into all VLAs. This doesn't require changes to addr, |
| // which has type T* where T is the first non-VLA element type. |
| do { |
| QualType elementType = arrayType->getElementType(); |
| arrayType = getContext().getAsArrayType(elementType); |
| |
| // If we only have VLA components, 'addr' requires no adjustment. |
| if (!arrayType) { |
| baseType = elementType; |
| return numVLAElements; |
| } |
| } while (isa<VariableArrayType>(arrayType)); |
| |
| // We get out here only if we find a constant array type |
| // inside the VLA. |
| } |
| |
| // We have some number of constant-length arrays, so addr should |
| // have LLVM type [M x [N x [...]]]*. Build a GEP that walks |
| // down to the first element of addr. |
| SmallVector<llvm::Value*, 8> gepIndices; |
| |
| // GEP down to the array type. |
| llvm::ConstantInt *zero = Builder.getInt32(0); |
| gepIndices.push_back(zero); |
| |
| uint64_t countFromCLAs = 1; |
| QualType eltType; |
| |
| llvm::ArrayType *llvmArrayType = |
| dyn_cast<llvm::ArrayType>( |
| cast<llvm::PointerType>(addr->getType())->getElementType()); |
| while (llvmArrayType) { |
| assert(isa<ConstantArrayType>(arrayType)); |
| assert(cast<ConstantArrayType>(arrayType)->getSize().getZExtValue() |
| == llvmArrayType->getNumElements()); |
| |
| gepIndices.push_back(zero); |
| countFromCLAs *= llvmArrayType->getNumElements(); |
| eltType = arrayType->getElementType(); |
| |
| llvmArrayType = |
| dyn_cast<llvm::ArrayType>(llvmArrayType->getElementType()); |
| arrayType = getContext().getAsArrayType(arrayType->getElementType()); |
| assert((!llvmArrayType || arrayType) && |
| "LLVM and Clang types are out-of-synch"); |
| } |
| |
| if (arrayType) { |
| // From this point onwards, the Clang array type has been emitted |
| // as some other type (probably a packed struct). Compute the array |
| // size, and just emit the 'begin' expression as a bitcast. |
| while (arrayType) { |
| countFromCLAs *= |
| cast<ConstantArrayType>(arrayType)->getSize().getZExtValue(); |
| eltType = arrayType->getElementType(); |
| arrayType = getContext().getAsArrayType(eltType); |
| } |
| |
| unsigned AddressSpace = addr->getType()->getPointerAddressSpace(); |
| llvm::Type *BaseType = ConvertType(eltType)->getPointerTo(AddressSpace); |
| addr = Builder.CreateBitCast(addr, BaseType, "array.begin"); |
| } else { |
| // Create the actual GEP. |
| addr = Builder.CreateInBoundsGEP(addr, gepIndices, "array.begin"); |
| } |
| |
| baseType = eltType; |
| |
| llvm::Value *numElements |
| = llvm::ConstantInt::get(SizeTy, countFromCLAs); |
| |
| // If we had any VLA dimensions, factor them in. |
| if (numVLAElements) |
| numElements = Builder.CreateNUWMul(numVLAElements, numElements); |
| |
| return numElements; |
| } |
| |
| std::pair<llvm::Value*, QualType> |
| CodeGenFunction::getVLASize(QualType type) { |
| const VariableArrayType *vla = getContext().getAsVariableArrayType(type); |
| assert(vla && "type was not a variable array type!"); |
| return getVLASize(vla); |
| } |
| |
| std::pair<llvm::Value*, QualType> |
| CodeGenFunction::getVLASize(const VariableArrayType *type) { |
| // The number of elements so far; always size_t. |
| llvm::Value *numElements = 0; |
| |
| QualType elementType; |
| do { |
| elementType = type->getElementType(); |
| llvm::Value *vlaSize = VLASizeMap[type->getSizeExpr()]; |
| assert(vlaSize && "no size for VLA!"); |
| assert(vlaSize->getType() == SizeTy); |
| |
| if (!numElements) { |
| numElements = vlaSize; |
| } else { |
| // It's undefined behavior if this wraps around, so mark it that way. |
| // FIXME: Teach -fcatch-undefined-behavior to trap this. |
| numElements = Builder.CreateNUWMul(numElements, vlaSize); |
| } |
| } while ((type = getContext().getAsVariableArrayType(elementType))); |
| |
| return std::pair<llvm::Value*,QualType>(numElements, elementType); |
| } |
| |
| void CodeGenFunction::EmitVariablyModifiedType(QualType type) { |
| assert(type->isVariablyModifiedType() && |
| "Must pass variably modified type to EmitVLASizes!"); |
| |
| EnsureInsertPoint(); |
| |
| // We're going to walk down into the type and look for VLA |
| // expressions. |
| do { |
| assert(type->isVariablyModifiedType()); |
| |
| const Type *ty = type.getTypePtr(); |
| switch (ty->getTypeClass()) { |
| |
| #define TYPE(Class, Base) |
| #define ABSTRACT_TYPE(Class, Base) |
| #define NON_CANONICAL_TYPE(Class, Base) |
| #define DEPENDENT_TYPE(Class, Base) case Type::Class: |
| #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) |
| #include "clang/AST/TypeNodes.def" |
| llvm_unreachable("unexpected dependent type!"); |
| |
| // These types are never variably-modified. |
| case Type::Builtin: |
| case Type::Complex: |
| case Type::Vector: |
| case Type::ExtVector: |
| case Type::Record: |
| case Type::Enum: |
| case Type::Elaborated: |
| case Type::TemplateSpecialization: |
| case Type::ObjCObject: |
| case Type::ObjCInterface: |
| case Type::ObjCObjectPointer: |
| llvm_unreachable("type class is never variably-modified!"); |
| |
| case Type::Pointer: |
| type = cast<PointerType>(ty)->getPointeeType(); |
| break; |
| |
| case Type::BlockPointer: |
| type = cast<BlockPointerType>(ty)->getPointeeType(); |
| break; |
| |
| case Type::LValueReference: |
| case Type::RValueReference: |
| type = cast<ReferenceType>(ty)->getPointeeType(); |
| break; |
| |
| case Type::MemberPointer: |
| type = cast<MemberPointerType>(ty)->getPointeeType(); |
| break; |
| |
| case Type::ConstantArray: |
| case Type::IncompleteArray: |
| // Losing element qualification here is fine. |
| type = cast<ArrayType>(ty)->getElementType(); |
| break; |
| |
| case Type::VariableArray: { |
| // Losing element qualification here is fine. |
| const VariableArrayType *vat = cast<VariableArrayType>(ty); |
| |
| // Unknown size indication requires no size computation. |
| // Otherwise, evaluate and record it. |
| if (const Expr *size = vat->getSizeExpr()) { |
| // It's possible that we might have emitted this already, |
| // e.g. with a typedef and a pointer to it. |
| llvm::Value *&entry = VLASizeMap[size]; |
| if (!entry) { |
| llvm::Value *Size = EmitScalarExpr(size); |
| |
| // C11 6.7.6.2p5: |
| // If the size is an expression that is not an integer constant |
| // expression [...] each time it is evaluated it shall have a value |
| // greater than zero. |
| if (getLangOpts().SanitizeVLABound && |
| size->getType()->isSignedIntegerType()) { |
| llvm::Value *Zero = llvm::Constant::getNullValue(Size->getType()); |
| llvm::Constant *StaticArgs[] = { |
| EmitCheckSourceLocation(size->getLocStart()), |
| EmitCheckTypeDescriptor(size->getType()) |
| }; |
| EmitCheck(Builder.CreateICmpSGT(Size, Zero), |
| "vla_bound_not_positive", StaticArgs, Size); |
| } |
| |
| // Always zexting here would be wrong if it weren't |
| // undefined behavior to have a negative bound. |
| entry = Builder.CreateIntCast(Size, SizeTy, /*signed*/ false); |
| } |
| } |
| type = vat->getElementType(); |
| break; |
| } |
| |
| case Type::FunctionProto: |
| case Type::FunctionNoProto: |
| type = cast<FunctionType>(ty)->getResultType(); |
| break; |
| |
| case Type::Paren: |
| case Type::TypeOf: |
| case Type::UnaryTransform: |
| case Type::Attributed: |
| case Type::SubstTemplateTypeParm: |
| // Keep walking after single level desugaring. |
| type = type.getSingleStepDesugaredType(getContext()); |
| break; |
| |
| case Type::Typedef: |
| case Type::Decltype: |
| case Type::Auto: |
| // Stop walking: nothing to do. |
| return; |
| |
| case Type::TypeOfExpr: |
| // Stop walking: emit typeof expression. |
| EmitIgnoredExpr(cast<TypeOfExprType>(ty)->getUnderlyingExpr()); |
| return; |
| |
| case Type::Atomic: |
| type = cast<AtomicType>(ty)->getValueType(); |
| break; |
| } |
| } while (type->isVariablyModifiedType()); |
| } |
| |
| llvm::Value* CodeGenFunction::EmitVAListRef(const Expr* E) { |
| if (getContext().getBuiltinVaListType()->isArrayType()) |
| return EmitScalarExpr(E); |
| return EmitLValue(E).getAddress(); |
| } |
| |
| void CodeGenFunction::EmitDeclRefExprDbgValue(const DeclRefExpr *E, |
| llvm::Constant *Init) { |
| assert (Init && "Invalid DeclRefExpr initializer!"); |
| if (CGDebugInfo *Dbg = getDebugInfo()) |
| if (CGM.getCodeGenOpts().getDebugInfo() >= CodeGenOptions::LimitedDebugInfo) |
| Dbg->EmitGlobalVariable(E->getDecl(), Init); |
| } |
| |
| CodeGenFunction::PeepholeProtection |
| CodeGenFunction::protectFromPeepholes(RValue rvalue) { |
| // At the moment, the only aggressive peephole we do in IR gen |
| // is trunc(zext) folding, but if we add more, we can easily |
| // extend this protection. |
| |
| if (!rvalue.isScalar()) return PeepholeProtection(); |
| llvm::Value *value = rvalue.getScalarVal(); |
| if (!isa<llvm::ZExtInst>(value)) return PeepholeProtection(); |
| |
| // Just make an extra bitcast. |
| assert(HaveInsertPoint()); |
| llvm::Instruction *inst = new llvm::BitCastInst(value, value->getType(), "", |
| Builder.GetInsertBlock()); |
| |
| PeepholeProtection protection; |
| protection.Inst = inst; |
| return protection; |
| } |
| |
| void CodeGenFunction::unprotectFromPeepholes(PeepholeProtection protection) { |
| if (!protection.Inst) return; |
| |
| // In theory, we could try to duplicate the peepholes now, but whatever. |
| protection.Inst->eraseFromParent(); |
| } |
| |
| llvm::Value *CodeGenFunction::EmitAnnotationCall(llvm::Value *AnnotationFn, |
| llvm::Value *AnnotatedVal, |
| llvm::StringRef AnnotationStr, |
| SourceLocation Location) { |
| llvm::Value *Args[4] = { |
| AnnotatedVal, |
| Builder.CreateBitCast(CGM.EmitAnnotationString(AnnotationStr), Int8PtrTy), |
| Builder.CreateBitCast(CGM.EmitAnnotationUnit(Location), Int8PtrTy), |
| CGM.EmitAnnotationLineNo(Location) |
| }; |
| return Builder.CreateCall(AnnotationFn, Args); |
| } |
| |
| void CodeGenFunction::EmitVarAnnotations(const VarDecl *D, llvm::Value *V) { |
| assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); |
| // FIXME We create a new bitcast for every annotation because that's what |
| // llvm-gcc was doing. |
| for (specific_attr_iterator<AnnotateAttr> |
| ai = D->specific_attr_begin<AnnotateAttr>(), |
| ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) |
| EmitAnnotationCall(CGM.getIntrinsic(llvm::Intrinsic::var_annotation), |
| Builder.CreateBitCast(V, CGM.Int8PtrTy, V->getName()), |
| (*ai)->getAnnotation(), D->getLocation()); |
| } |
| |
| llvm::Value *CodeGenFunction::EmitFieldAnnotations(const FieldDecl *D, |
| llvm::Value *V) { |
| assert(D->hasAttr<AnnotateAttr>() && "no annotate attribute"); |
| llvm::Type *VTy = V->getType(); |
| llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::ptr_annotation, |
| CGM.Int8PtrTy); |
| |
| for (specific_attr_iterator<AnnotateAttr> |
| ai = D->specific_attr_begin<AnnotateAttr>(), |
| ae = D->specific_attr_end<AnnotateAttr>(); ai != ae; ++ai) { |
| // FIXME Always emit the cast inst so we can differentiate between |
| // annotation on the first field of a struct and annotation on the struct |
| // itself. |
| if (VTy != CGM.Int8PtrTy) |
| V = Builder.Insert(new llvm::BitCastInst(V, CGM.Int8PtrTy)); |
| V = EmitAnnotationCall(F, V, (*ai)->getAnnotation(), D->getLocation()); |
| V = Builder.CreateBitCast(V, VTy); |
| } |
| |
| return V; |
| } |