//===--- CGCall.cpp - Encapsulate calling convention details ----*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // These classes wrap the information about a call or function // definition used to handle ABI compliancy. // //===----------------------------------------------------------------------===// #include "CGCall.h" #include "CGCXXABI.h" #include "ABIInfo.h" #include "CodeGenFunction.h" #include "CodeGenModule.h" #include "clang/Basic/TargetInfo.h" #include "clang/AST/Decl.h" #include "clang/AST/DeclCXX.h" #include "clang/AST/DeclObjC.h" #include "clang/Frontend/CodeGenOptions.h" #include "llvm/Attributes.h" #include "llvm/Support/CallSite.h" #include "llvm/Target/TargetData.h" #include "llvm/InlineAsm.h" #include "llvm/Transforms/Utils/Local.h" using namespace clang; using namespace CodeGen; /***/ static unsigned ClangCallConvToLLVMCallConv(CallingConv CC) { switch (CC) { default: return llvm::CallingConv::C; case CC_X86StdCall: return llvm::CallingConv::X86_StdCall; case CC_X86FastCall: return llvm::CallingConv::X86_FastCall; case CC_X86ThisCall: return llvm::CallingConv::X86_ThisCall; case CC_AAPCS: return llvm::CallingConv::ARM_AAPCS; case CC_AAPCS_VFP: return llvm::CallingConv::ARM_AAPCS_VFP; // TODO: add support for CC_X86Pascal to llvm } } /// Derives the 'this' type for codegen purposes, i.e. ignoring method /// qualification. /// FIXME: address space qualification? static CanQualType GetThisType(ASTContext &Context, const CXXRecordDecl *RD) { QualType RecTy = Context.getTagDeclType(RD)->getCanonicalTypeInternal(); return Context.getPointerType(CanQualType::CreateUnsafe(RecTy)); } /// Returns the canonical formal type of the given C++ method. static CanQual GetFormalType(const CXXMethodDecl *MD) { return MD->getType()->getCanonicalTypeUnqualified() .getAs(); } /// Returns the "extra-canonicalized" return type, which discards /// qualifiers on the return type. Codegen doesn't care about them, /// and it makes ABI code a little easier to be able to assume that /// all parameter and return types are top-level unqualified. static CanQualType GetReturnType(QualType RetTy) { return RetTy->getCanonicalTypeUnqualified().getUnqualifiedType(); } const CGFunctionInfo & CodeGenTypes::getFunctionInfo(CanQual FTNP) { return getFunctionInfo(FTNP->getResultType().getUnqualifiedType(), llvm::SmallVector(), FTNP->getExtInfo()); } /// \param Args - contains any initial parameters besides those /// in the formal type static const CGFunctionInfo &getFunctionInfo(CodeGenTypes &CGT, llvm::SmallVectorImpl &ArgTys, CanQual FTP) { // FIXME: Kill copy. for (unsigned i = 0, e = FTP->getNumArgs(); i != e; ++i) ArgTys.push_back(FTP->getArgType(i)); CanQualType ResTy = FTP->getResultType().getUnqualifiedType(); return CGT.getFunctionInfo(ResTy, ArgTys, FTP->getExtInfo()); } const CGFunctionInfo & CodeGenTypes::getFunctionInfo(CanQual FTP) { llvm::SmallVector ArgTys; return ::getFunctionInfo(*this, ArgTys, FTP); } static CallingConv getCallingConventionForDecl(const Decl *D) { // Set the appropriate calling convention for the Function. if (D->hasAttr()) return CC_X86StdCall; if (D->hasAttr()) return CC_X86FastCall; if (D->hasAttr()) return CC_X86ThisCall; if (D->hasAttr()) return CC_X86Pascal; if (PcsAttr *PCS = D->getAttr()) return (PCS->getPCS() == PcsAttr::AAPCS ? CC_AAPCS : CC_AAPCS_VFP); return CC_C; } const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXRecordDecl *RD, const FunctionProtoType *FTP) { llvm::SmallVector ArgTys; // Add the 'this' pointer. ArgTys.push_back(GetThisType(Context, RD)); return ::getFunctionInfo(*this, ArgTys, FTP->getCanonicalTypeUnqualified().getAs()); } const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXMethodDecl *MD) { llvm::SmallVector ArgTys; assert(!isa(MD) && "wrong method for contructors!"); assert(!isa(MD) && "wrong method for destructors!"); // Add the 'this' pointer unless this is a static method. if (MD->isInstance()) ArgTys.push_back(GetThisType(Context, MD->getParent())); return ::getFunctionInfo(*this, ArgTys, GetFormalType(MD)); } const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXConstructorDecl *D, CXXCtorType Type) { llvm::SmallVector ArgTys; ArgTys.push_back(GetThisType(Context, D->getParent())); CanQualType ResTy = Context.VoidTy; TheCXXABI.BuildConstructorSignature(D, Type, ResTy, ArgTys); CanQual FTP = GetFormalType(D); // Add the formal parameters. for (unsigned i = 0, e = FTP->getNumArgs(); i != e; ++i) ArgTys.push_back(FTP->getArgType(i)); return getFunctionInfo(ResTy, ArgTys, FTP->getExtInfo()); } const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXDestructorDecl *D, CXXDtorType Type) { llvm::SmallVector ArgTys; ArgTys.push_back(GetThisType(Context, D->getParent())); CanQualType ResTy = Context.VoidTy; TheCXXABI.BuildDestructorSignature(D, Type, ResTy, ArgTys); CanQual FTP = GetFormalType(D); assert(FTP->getNumArgs() == 0 && "dtor with formal parameters"); return getFunctionInfo(ResTy, ArgTys, FTP->getExtInfo()); } const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const FunctionDecl *FD) { if (const CXXMethodDecl *MD = dyn_cast(FD)) if (MD->isInstance()) return getFunctionInfo(MD); CanQualType FTy = FD->getType()->getCanonicalTypeUnqualified(); assert(isa(FTy)); if (isa(FTy)) return getFunctionInfo(FTy.getAs()); assert(isa(FTy)); return getFunctionInfo(FTy.getAs()); } const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const ObjCMethodDecl *MD) { llvm::SmallVector ArgTys; ArgTys.push_back(Context.getCanonicalParamType(MD->getSelfDecl()->getType())); ArgTys.push_back(Context.getCanonicalParamType(Context.getObjCSelType())); // FIXME: Kill copy? for (ObjCMethodDecl::param_iterator i = MD->param_begin(), e = MD->param_end(); i != e; ++i) { ArgTys.push_back(Context.getCanonicalParamType((*i)->getType())); } FunctionType::ExtInfo einfo; einfo = einfo.withCallingConv(getCallingConventionForDecl(MD)); if (getContext().getLangOptions().ObjCAutoRefCount && MD->hasAttr()) einfo = einfo.withProducesResult(true); return getFunctionInfo(GetReturnType(MD->getResultType()), ArgTys, einfo); } const CGFunctionInfo &CodeGenTypes::getFunctionInfo(GlobalDecl GD) { // FIXME: Do we need to handle ObjCMethodDecl? const FunctionDecl *FD = cast(GD.getDecl()); if (const CXXConstructorDecl *CD = dyn_cast(FD)) return getFunctionInfo(CD, GD.getCtorType()); if (const CXXDestructorDecl *DD = dyn_cast(FD)) return getFunctionInfo(DD, GD.getDtorType()); return getFunctionInfo(FD); } const CGFunctionInfo &CodeGenTypes::getFunctionInfo(QualType ResTy, const CallArgList &Args, const FunctionType::ExtInfo &Info) { // FIXME: Kill copy. llvm::SmallVector ArgTys; for (CallArgList::const_iterator i = Args.begin(), e = Args.end(); i != e; ++i) ArgTys.push_back(Context.getCanonicalParamType(i->Ty)); return getFunctionInfo(GetReturnType(ResTy), ArgTys, Info); } const CGFunctionInfo &CodeGenTypes::getFunctionInfo(QualType ResTy, const FunctionArgList &Args, const FunctionType::ExtInfo &Info) { // FIXME: Kill copy. llvm::SmallVector ArgTys; for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end(); i != e; ++i) ArgTys.push_back(Context.getCanonicalParamType((*i)->getType())); return getFunctionInfo(GetReturnType(ResTy), ArgTys, Info); } const CGFunctionInfo &CodeGenTypes::getNullaryFunctionInfo() { llvm::SmallVector args; return getFunctionInfo(getContext().VoidTy, args, FunctionType::ExtInfo()); } const CGFunctionInfo &CodeGenTypes::getFunctionInfo(CanQualType ResTy, const llvm::SmallVectorImpl &ArgTys, const FunctionType::ExtInfo &Info) { #ifndef NDEBUG for (llvm::SmallVectorImpl::const_iterator I = ArgTys.begin(), E = ArgTys.end(); I != E; ++I) assert(I->isCanonicalAsParam()); #endif unsigned CC = ClangCallConvToLLVMCallConv(Info.getCC()); // Lookup or create unique function info. llvm::FoldingSetNodeID ID; CGFunctionInfo::Profile(ID, Info, ResTy, ArgTys.begin(), ArgTys.end()); void *InsertPos = 0; CGFunctionInfo *FI = FunctionInfos.FindNodeOrInsertPos(ID, InsertPos); if (FI) return *FI; // Construct the function info. FI = new CGFunctionInfo(CC, Info.getNoReturn(), Info.getProducesResult(), Info.getHasRegParm(), Info.getRegParm(), ResTy, ArgTys.data(), ArgTys.size()); FunctionInfos.InsertNode(FI, InsertPos); bool Inserted = FunctionsBeingProcessed.insert(FI); (void)Inserted; assert(Inserted && "Recursively being processed?"); // Compute ABI information. getABIInfo().computeInfo(*FI); // Loop over all of the computed argument and return value info. If any of // them are direct or extend without a specified coerce type, specify the // default now. ABIArgInfo &RetInfo = FI->getReturnInfo(); if (RetInfo.canHaveCoerceToType() && RetInfo.getCoerceToType() == 0) RetInfo.setCoerceToType(ConvertType(FI->getReturnType())); for (CGFunctionInfo::arg_iterator I = FI->arg_begin(), E = FI->arg_end(); I != E; ++I) if (I->info.canHaveCoerceToType() && I->info.getCoerceToType() == 0) I->info.setCoerceToType(ConvertType(I->type)); bool Erased = FunctionsBeingProcessed.erase(FI); (void)Erased; assert(Erased && "Not in set?"); return *FI; } CGFunctionInfo::CGFunctionInfo(unsigned _CallingConvention, bool _NoReturn, bool returnsRetained, bool _HasRegParm, unsigned _RegParm, CanQualType ResTy, const CanQualType *ArgTys, unsigned NumArgTys) : CallingConvention(_CallingConvention), EffectiveCallingConvention(_CallingConvention), NoReturn(_NoReturn), ReturnsRetained(returnsRetained), HasRegParm(_HasRegParm), RegParm(_RegParm) { NumArgs = NumArgTys; // FIXME: Coallocate with the CGFunctionInfo object. Args = new ArgInfo[1 + NumArgTys]; Args[0].type = ResTy; for (unsigned i = 0; i != NumArgTys; ++i) Args[1 + i].type = ArgTys[i]; } /***/ void CodeGenTypes::GetExpandedTypes(QualType type, llvm::SmallVectorImpl &expandedTypes) { const RecordType *RT = type->getAsStructureType(); assert(RT && "Can only expand structure types."); const RecordDecl *RD = RT->getDecl(); assert(!RD->hasFlexibleArrayMember() && "Cannot expand structure with flexible array."); for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); i != e; ++i) { const FieldDecl *FD = *i; assert(!FD->isBitField() && "Cannot expand structure with bit-field members."); QualType fieldType = FD->getType(); if (fieldType->isRecordType()) GetExpandedTypes(fieldType, expandedTypes); else expandedTypes.push_back(ConvertType(fieldType)); } } llvm::Function::arg_iterator CodeGenFunction::ExpandTypeFromArgs(QualType Ty, LValue LV, llvm::Function::arg_iterator AI) { const RecordType *RT = Ty->getAsStructureType(); assert(RT && "Can only expand structure types."); RecordDecl *RD = RT->getDecl(); assert(LV.isSimple() && "Unexpected non-simple lvalue during struct expansion."); llvm::Value *Addr = LV.getAddress(); for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); i != e; ++i) { FieldDecl *FD = *i; QualType FT = FD->getType(); // FIXME: What are the right qualifiers here? LValue LV = EmitLValueForField(Addr, FD, 0); if (CodeGenFunction::hasAggregateLLVMType(FT)) { AI = ExpandTypeFromArgs(FT, LV, AI); } else { EmitStoreThroughLValue(RValue::get(AI), LV); ++AI; } } return AI; } /// EnterStructPointerForCoercedAccess - Given a struct pointer that we are /// accessing some number of bytes out of it, try to gep into the struct to get /// at its inner goodness. Dive as deep as possible without entering an element /// with an in-memory size smaller than DstSize. static llvm::Value * EnterStructPointerForCoercedAccess(llvm::Value *SrcPtr, const llvm::StructType *SrcSTy, uint64_t DstSize, CodeGenFunction &CGF) { // We can't dive into a zero-element struct. if (SrcSTy->getNumElements() == 0) return SrcPtr; const llvm::Type *FirstElt = SrcSTy->getElementType(0); // If the first elt is at least as large as what we're looking for, or if the // first element is the same size as the whole struct, we can enter it. uint64_t FirstEltSize = CGF.CGM.getTargetData().getTypeAllocSize(FirstElt); if (FirstEltSize < DstSize && FirstEltSize < CGF.CGM.getTargetData().getTypeAllocSize(SrcSTy)) return SrcPtr; // GEP into the first element. SrcPtr = CGF.Builder.CreateConstGEP2_32(SrcPtr, 0, 0, "coerce.dive"); // If the first element is a struct, recurse. const llvm::Type *SrcTy = cast(SrcPtr->getType())->getElementType(); if (const llvm::StructType *SrcSTy = dyn_cast(SrcTy)) return EnterStructPointerForCoercedAccess(SrcPtr, SrcSTy, DstSize, CGF); return SrcPtr; } /// CoerceIntOrPtrToIntOrPtr - Convert a value Val to the specific Ty where both /// are either integers or pointers. This does a truncation of the value if it /// is too large or a zero extension if it is too small. static llvm::Value *CoerceIntOrPtrToIntOrPtr(llvm::Value *Val, const llvm::Type *Ty, CodeGenFunction &CGF) { if (Val->getType() == Ty) return Val; if (isa(Val->getType())) { // If this is Pointer->Pointer avoid conversion to and from int. if (isa(Ty)) return CGF.Builder.CreateBitCast(Val, Ty, "coerce.val"); // Convert the pointer to an integer so we can play with its width. Val = CGF.Builder.CreatePtrToInt(Val, CGF.IntPtrTy, "coerce.val.pi"); } const llvm::Type *DestIntTy = Ty; if (isa(DestIntTy)) DestIntTy = CGF.IntPtrTy; if (Val->getType() != DestIntTy) Val = CGF.Builder.CreateIntCast(Val, DestIntTy, false, "coerce.val.ii"); if (isa(Ty)) Val = CGF.Builder.CreateIntToPtr(Val, Ty, "coerce.val.ip"); return Val; } /// CreateCoercedLoad - Create a load from \arg SrcPtr interpreted as /// a pointer to an object of type \arg Ty. /// /// This safely handles the case when the src type is smaller than the /// destination type; in this situation the values of bits which not /// present in the src are undefined. static llvm::Value *CreateCoercedLoad(llvm::Value *SrcPtr, const llvm::Type *Ty, CodeGenFunction &CGF) { const llvm::Type *SrcTy = cast(SrcPtr->getType())->getElementType(); // If SrcTy and Ty are the same, just do a load. if (SrcTy == Ty) return CGF.Builder.CreateLoad(SrcPtr); uint64_t DstSize = CGF.CGM.getTargetData().getTypeAllocSize(Ty); if (const llvm::StructType *SrcSTy = dyn_cast(SrcTy)) { SrcPtr = EnterStructPointerForCoercedAccess(SrcPtr, SrcSTy, DstSize, CGF); SrcTy = cast(SrcPtr->getType())->getElementType(); } uint64_t SrcSize = CGF.CGM.getTargetData().getTypeAllocSize(SrcTy); // If the source and destination are integer or pointer types, just do an // extension or truncation to the desired type. if ((isa(Ty) || isa(Ty)) && (isa(SrcTy) || isa(SrcTy))) { llvm::LoadInst *Load = CGF.Builder.CreateLoad(SrcPtr); return CoerceIntOrPtrToIntOrPtr(Load, Ty, CGF); } // If load is legal, just bitcast the src pointer. if (SrcSize >= DstSize) { // Generally SrcSize is never greater than DstSize, since this means we are // losing bits. However, this can happen in cases where the structure has // additional padding, for example due to a user specified alignment. // // FIXME: Assert that we aren't truncating non-padding bits when have access // to that information. llvm::Value *Casted = CGF.Builder.CreateBitCast(SrcPtr, llvm::PointerType::getUnqual(Ty)); llvm::LoadInst *Load = CGF.Builder.CreateLoad(Casted); // FIXME: Use better alignment / avoid requiring aligned load. Load->setAlignment(1); return Load; } // Otherwise do coercion through memory. This is stupid, but // simple. llvm::Value *Tmp = CGF.CreateTempAlloca(Ty); llvm::Value *Casted = CGF.Builder.CreateBitCast(Tmp, llvm::PointerType::getUnqual(SrcTy)); llvm::StoreInst *Store = CGF.Builder.CreateStore(CGF.Builder.CreateLoad(SrcPtr), Casted); // FIXME: Use better alignment / avoid requiring aligned store. Store->setAlignment(1); return CGF.Builder.CreateLoad(Tmp); } // Function to store a first-class aggregate into memory. We prefer to // store the elements rather than the aggregate to be more friendly to // fast-isel. // FIXME: Do we need to recurse here? static void BuildAggStore(CodeGenFunction &CGF, llvm::Value *Val, llvm::Value *DestPtr, bool DestIsVolatile, bool LowAlignment) { // Prefer scalar stores to first-class aggregate stores. if (const llvm::StructType *STy = dyn_cast(Val->getType())) { for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { llvm::Value *EltPtr = CGF.Builder.CreateConstGEP2_32(DestPtr, 0, i); llvm::Value *Elt = CGF.Builder.CreateExtractValue(Val, i); llvm::StoreInst *SI = CGF.Builder.CreateStore(Elt, EltPtr, DestIsVolatile); if (LowAlignment) SI->setAlignment(1); } } else { CGF.Builder.CreateStore(Val, DestPtr, DestIsVolatile); } } /// CreateCoercedStore - Create a store to \arg DstPtr from \arg Src, /// where the source and destination may have different types. /// /// This safely handles the case when the src type is larger than the /// destination type; the upper bits of the src will be lost. static void CreateCoercedStore(llvm::Value *Src, llvm::Value *DstPtr, bool DstIsVolatile, CodeGenFunction &CGF) { const llvm::Type *SrcTy = Src->getType(); const llvm::Type *DstTy = cast(DstPtr->getType())->getElementType(); if (SrcTy == DstTy) { CGF.Builder.CreateStore(Src, DstPtr, DstIsVolatile); return; } uint64_t SrcSize = CGF.CGM.getTargetData().getTypeAllocSize(SrcTy); if (const llvm::StructType *DstSTy = dyn_cast(DstTy)) { DstPtr = EnterStructPointerForCoercedAccess(DstPtr, DstSTy, SrcSize, CGF); DstTy = cast(DstPtr->getType())->getElementType(); } // If the source and destination are integer or pointer types, just do an // extension or truncation to the desired type. if ((isa(SrcTy) || isa(SrcTy)) && (isa(DstTy) || isa(DstTy))) { Src = CoerceIntOrPtrToIntOrPtr(Src, DstTy, CGF); CGF.Builder.CreateStore(Src, DstPtr, DstIsVolatile); return; } uint64_t DstSize = CGF.CGM.getTargetData().getTypeAllocSize(DstTy); // If store is legal, just bitcast the src pointer. if (SrcSize <= DstSize) { llvm::Value *Casted = CGF.Builder.CreateBitCast(DstPtr, llvm::PointerType::getUnqual(SrcTy)); // FIXME: Use better alignment / avoid requiring aligned store. BuildAggStore(CGF, Src, Casted, DstIsVolatile, true); } else { // Otherwise do coercion through memory. This is stupid, but // simple. // Generally SrcSize is never greater than DstSize, since this means we are // losing bits. However, this can happen in cases where the structure has // additional padding, for example due to a user specified alignment. // // FIXME: Assert that we aren't truncating non-padding bits when have access // to that information. llvm::Value *Tmp = CGF.CreateTempAlloca(SrcTy); CGF.Builder.CreateStore(Src, Tmp); llvm::Value *Casted = CGF.Builder.CreateBitCast(Tmp, llvm::PointerType::getUnqual(DstTy)); llvm::LoadInst *Load = CGF.Builder.CreateLoad(Casted); // FIXME: Use better alignment / avoid requiring aligned load. Load->setAlignment(1); CGF.Builder.CreateStore(Load, DstPtr, DstIsVolatile); } } /***/ bool CodeGenModule::ReturnTypeUsesSRet(const CGFunctionInfo &FI) { return FI.getReturnInfo().isIndirect(); } bool CodeGenModule::ReturnTypeUsesFPRet(QualType ResultType) { if (const BuiltinType *BT = ResultType->getAs()) { switch (BT->getKind()) { default: return false; case BuiltinType::Float: return getContext().Target.useObjCFPRetForRealType(TargetInfo::Float); case BuiltinType::Double: return getContext().Target.useObjCFPRetForRealType(TargetInfo::Double); case BuiltinType::LongDouble: return getContext().Target.useObjCFPRetForRealType( TargetInfo::LongDouble); } } return false; } llvm::FunctionType *CodeGenTypes::GetFunctionType(GlobalDecl GD) { const CGFunctionInfo &FI = getFunctionInfo(GD); // For definition purposes, don't consider a K&R function variadic. bool Variadic = false; if (const FunctionProtoType *FPT = cast(GD.getDecl())->getType()->getAs()) Variadic = FPT->isVariadic(); return GetFunctionType(FI, Variadic); } llvm::FunctionType * CodeGenTypes::GetFunctionType(const CGFunctionInfo &FI, bool isVariadic) { bool Inserted = FunctionsBeingProcessed.insert(&FI); (void)Inserted; assert(Inserted && "Recursively being processed?"); llvm::SmallVector argTypes; const llvm::Type *resultType = 0; const ABIArgInfo &retAI = FI.getReturnInfo(); switch (retAI.getKind()) { case ABIArgInfo::Expand: llvm_unreachable("Invalid ABI kind for return argument"); case ABIArgInfo::Extend: case ABIArgInfo::Direct: resultType = retAI.getCoerceToType(); break; case ABIArgInfo::Indirect: { assert(!retAI.getIndirectAlign() && "Align unused on indirect return."); resultType = llvm::Type::getVoidTy(getLLVMContext()); QualType ret = FI.getReturnType(); const llvm::Type *ty = ConvertType(ret); unsigned addressSpace = Context.getTargetAddressSpace(ret); argTypes.push_back(llvm::PointerType::get(ty, addressSpace)); break; } case ABIArgInfo::Ignore: resultType = llvm::Type::getVoidTy(getLLVMContext()); break; } for (CGFunctionInfo::const_arg_iterator it = FI.arg_begin(), ie = FI.arg_end(); it != ie; ++it) { const ABIArgInfo &argAI = it->info; switch (argAI.getKind()) { case ABIArgInfo::Ignore: break; case ABIArgInfo::Indirect: { // indirect arguments are always on the stack, which is addr space #0. const llvm::Type *LTy = ConvertTypeForMem(it->type); argTypes.push_back(LTy->getPointerTo()); break; } case ABIArgInfo::Extend: case ABIArgInfo::Direct: { // If the coerce-to type is a first class aggregate, flatten it. Either // way is semantically identical, but fast-isel and the optimizer // generally likes scalar values better than FCAs. llvm::Type *argType = argAI.getCoerceToType(); if (const llvm::StructType *st = dyn_cast(argType)) { for (unsigned i = 0, e = st->getNumElements(); i != e; ++i) argTypes.push_back(st->getElementType(i)); } else { argTypes.push_back(argType); } break; } case ABIArgInfo::Expand: GetExpandedTypes(it->type, argTypes); break; } } bool Erased = FunctionsBeingProcessed.erase(&FI); (void)Erased; assert(Erased && "Not in set?"); return llvm::FunctionType::get(resultType, argTypes, isVariadic); } const llvm::Type *CodeGenTypes::GetFunctionTypeForVTable(GlobalDecl GD) { const CXXMethodDecl *MD = cast(GD.getDecl()); const FunctionProtoType *FPT = MD->getType()->getAs(); if (!isFuncTypeConvertible(FPT)) return llvm::StructType::get(getLLVMContext()); const CGFunctionInfo *Info; if (isa(MD)) Info = &getFunctionInfo(cast(MD), GD.getDtorType()); else Info = &getFunctionInfo(MD); return GetFunctionType(*Info, FPT->isVariadic()); } void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI, const Decl *TargetDecl, AttributeListType &PAL, unsigned &CallingConv) { unsigned FuncAttrs = 0; unsigned RetAttrs = 0; CallingConv = FI.getEffectiveCallingConvention(); if (FI.isNoReturn()) FuncAttrs |= llvm::Attribute::NoReturn; // FIXME: handle sseregparm someday... if (TargetDecl) { if (TargetDecl->hasAttr()) FuncAttrs |= llvm::Attribute::NoUnwind; else if (const FunctionDecl *Fn = dyn_cast(TargetDecl)) { const FunctionProtoType *FPT = Fn->getType()->getAs(); if (FPT && FPT->isNothrow(getContext())) FuncAttrs |= llvm::Attribute::NoUnwind; } if (TargetDecl->hasAttr()) FuncAttrs |= llvm::Attribute::NoReturn; if (TargetDecl->hasAttr()) FuncAttrs |= llvm::Attribute::ReadNone; else if (TargetDecl->hasAttr()) FuncAttrs |= llvm::Attribute::ReadOnly; if (TargetDecl->hasAttr()) RetAttrs |= llvm::Attribute::NoAlias; } if (CodeGenOpts.OptimizeSize) FuncAttrs |= llvm::Attribute::OptimizeForSize; if (CodeGenOpts.DisableRedZone) FuncAttrs |= llvm::Attribute::NoRedZone; if (CodeGenOpts.NoImplicitFloat) FuncAttrs |= llvm::Attribute::NoImplicitFloat; QualType RetTy = FI.getReturnType(); unsigned Index = 1; const ABIArgInfo &RetAI = FI.getReturnInfo(); switch (RetAI.getKind()) { case ABIArgInfo::Extend: if (RetTy->hasSignedIntegerRepresentation()) RetAttrs |= llvm::Attribute::SExt; else if (RetTy->hasUnsignedIntegerRepresentation()) RetAttrs |= llvm::Attribute::ZExt; break; case ABIArgInfo::Direct: case ABIArgInfo::Ignore: break; case ABIArgInfo::Indirect: PAL.push_back(llvm::AttributeWithIndex::get(Index, llvm::Attribute::StructRet)); ++Index; // sret disables readnone and readonly FuncAttrs &= ~(llvm::Attribute::ReadOnly | llvm::Attribute::ReadNone); break; case ABIArgInfo::Expand: assert(0 && "Invalid ABI kind for return argument"); } if (RetAttrs) PAL.push_back(llvm::AttributeWithIndex::get(0, RetAttrs)); // FIXME: RegParm should be reduced in case of global register variable. signed RegParm; if (FI.getHasRegParm()) RegParm = FI.getRegParm(); else RegParm = CodeGenOpts.NumRegisterParameters; unsigned PointerWidth = getContext().Target.getPointerWidth(0); for (CGFunctionInfo::const_arg_iterator it = FI.arg_begin(), ie = FI.arg_end(); it != ie; ++it) { QualType ParamType = it->type; const ABIArgInfo &AI = it->info; unsigned Attributes = 0; // 'restrict' -> 'noalias' is done in EmitFunctionProlog when we // have the corresponding parameter variable. It doesn't make // sense to do it here because parameters are so messed up. switch (AI.getKind()) { case ABIArgInfo::Extend: if (ParamType->isSignedIntegerOrEnumerationType()) Attributes |= llvm::Attribute::SExt; else if (ParamType->isUnsignedIntegerOrEnumerationType()) Attributes |= llvm::Attribute::ZExt; // FALL THROUGH case ABIArgInfo::Direct: if (RegParm > 0 && (ParamType->isIntegerType() || ParamType->isPointerType())) { RegParm -= (Context.getTypeSize(ParamType) + PointerWidth - 1) / PointerWidth; if (RegParm >= 0) Attributes |= llvm::Attribute::InReg; } // FIXME: handle sseregparm someday... if (const llvm::StructType *STy = dyn_cast(AI.getCoerceToType())) Index += STy->getNumElements()-1; // 1 will be added below. break; case ABIArgInfo::Indirect: if (AI.getIndirectByVal()) Attributes |= llvm::Attribute::ByVal; Attributes |= llvm::Attribute::constructAlignmentFromInt(AI.getIndirectAlign()); // byval disables readnone and readonly. FuncAttrs &= ~(llvm::Attribute::ReadOnly | llvm::Attribute::ReadNone); break; case ABIArgInfo::Ignore: // Skip increment, no matching LLVM parameter. continue; case ABIArgInfo::Expand: { llvm::SmallVector types; // FIXME: This is rather inefficient. Do we ever actually need to do // anything here? The result should be just reconstructed on the other // side, so extension should be a non-issue. getTypes().GetExpandedTypes(ParamType, types); Index += types.size(); continue; } } if (Attributes) PAL.push_back(llvm::AttributeWithIndex::get(Index, Attributes)); ++Index; } if (FuncAttrs) PAL.push_back(llvm::AttributeWithIndex::get(~0, FuncAttrs)); } /// An argument came in as a promoted argument; demote it back to its /// declared type. static llvm::Value *emitArgumentDemotion(CodeGenFunction &CGF, const VarDecl *var, llvm::Value *value) { const llvm::Type *varType = CGF.ConvertType(var->getType()); // This can happen with promotions that actually don't change the // underlying type, like the enum promotions. if (value->getType() == varType) return value; assert((varType->isIntegerTy() || varType->isFloatingPointTy()) && "unexpected promotion type"); if (isa(varType)) return CGF.Builder.CreateTrunc(value, varType, "arg.unpromote"); return CGF.Builder.CreateFPCast(value, varType, "arg.unpromote"); } void CodeGenFunction::EmitFunctionProlog(const CGFunctionInfo &FI, llvm::Function *Fn, const FunctionArgList &Args) { // If this is an implicit-return-zero function, go ahead and // initialize the return value. TODO: it might be nice to have // a more general mechanism for this that didn't require synthesized // return statements. if (const FunctionDecl *FD = dyn_cast_or_null(CurFuncDecl)) { if (FD->hasImplicitReturnZero()) { QualType RetTy = FD->getResultType().getUnqualifiedType(); const llvm::Type* LLVMTy = CGM.getTypes().ConvertType(RetTy); llvm::Constant* Zero = llvm::Constant::getNullValue(LLVMTy); Builder.CreateStore(Zero, ReturnValue); } } // FIXME: We no longer need the types from FunctionArgList; lift up and // simplify. // Emit allocs for param decls. Give the LLVM Argument nodes names. llvm::Function::arg_iterator AI = Fn->arg_begin(); // Name the struct return argument. if (CGM.ReturnTypeUsesSRet(FI)) { AI->setName("agg.result"); ++AI; } assert(FI.arg_size() == Args.size() && "Mismatch between function signature & arguments."); unsigned ArgNo = 1; CGFunctionInfo::const_arg_iterator info_it = FI.arg_begin(); for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end(); i != e; ++i, ++info_it, ++ArgNo) { const VarDecl *Arg = *i; QualType Ty = info_it->type; const ABIArgInfo &ArgI = info_it->info; bool isPromoted = isa(Arg) && cast(Arg)->isKNRPromoted(); switch (ArgI.getKind()) { case ABIArgInfo::Indirect: { llvm::Value *V = AI; if (hasAggregateLLVMType(Ty)) { // Aggregates and complex variables are accessed by reference. All we // need to do is realign the value, if requested if (ArgI.getIndirectRealign()) { llvm::Value *AlignedTemp = CreateMemTemp(Ty, "coerce"); // Copy from the incoming argument pointer to the temporary with the // appropriate alignment. // // FIXME: We should have a common utility for generating an aggregate // copy. const llvm::Type *I8PtrTy = Builder.getInt8PtrTy(); CharUnits Size = getContext().getTypeSizeInChars(Ty); llvm::Value *Dst = Builder.CreateBitCast(AlignedTemp, I8PtrTy); llvm::Value *Src = Builder.CreateBitCast(V, I8PtrTy); Builder.CreateMemCpy(Dst, Src, llvm::ConstantInt::get(IntPtrTy, Size.getQuantity()), ArgI.getIndirectAlign(), false); V = AlignedTemp; } } else { // Load scalar value from indirect argument. CharUnits Alignment = getContext().getTypeAlignInChars(Ty); V = EmitLoadOfScalar(V, false, Alignment.getQuantity(), Ty); if (isPromoted) V = emitArgumentDemotion(*this, Arg, V); } EmitParmDecl(*Arg, V, ArgNo); break; } case ABIArgInfo::Extend: case ABIArgInfo::Direct: { // If we have the trivial case, handle it with no muss and fuss. if (!isa(ArgI.getCoerceToType()) && ArgI.getCoerceToType() == ConvertType(Ty) && ArgI.getDirectOffset() == 0) { assert(AI != Fn->arg_end() && "Argument mismatch!"); llvm::Value *V = AI; if (Arg->getType().isRestrictQualified()) AI->addAttr(llvm::Attribute::NoAlias); if (isPromoted) V = emitArgumentDemotion(*this, Arg, V); EmitParmDecl(*Arg, V, ArgNo); break; } llvm::AllocaInst *Alloca = CreateMemTemp(Ty, "coerce"); // The alignment we need to use is the max of the requested alignment for // the argument plus the alignment required by our access code below. unsigned AlignmentToUse = CGM.getTargetData().getABITypeAlignment(ArgI.getCoerceToType()); AlignmentToUse = std::max(AlignmentToUse, (unsigned)getContext().getDeclAlign(Arg).getQuantity()); Alloca->setAlignment(AlignmentToUse); llvm::Value *V = Alloca; llvm::Value *Ptr = V; // Pointer to store into. // If the value is offset in memory, apply the offset now. if (unsigned Offs = ArgI.getDirectOffset()) { Ptr = Builder.CreateBitCast(Ptr, Builder.getInt8PtrTy()); Ptr = Builder.CreateConstGEP1_32(Ptr, Offs); Ptr = Builder.CreateBitCast(Ptr, llvm::PointerType::getUnqual(ArgI.getCoerceToType())); } // If the coerce-to type is a first class aggregate, we flatten it and // pass the elements. Either way is semantically identical, but fast-isel // and the optimizer generally likes scalar values better than FCAs. if (const llvm::StructType *STy = dyn_cast(ArgI.getCoerceToType())) { Ptr = Builder.CreateBitCast(Ptr, llvm::PointerType::getUnqual(STy)); for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { assert(AI != Fn->arg_end() && "Argument mismatch!"); AI->setName(Arg->getName() + ".coerce" + llvm::Twine(i)); llvm::Value *EltPtr = Builder.CreateConstGEP2_32(Ptr, 0, i); Builder.CreateStore(AI++, EltPtr); } } else { // Simple case, just do a coerced store of the argument into the alloca. assert(AI != Fn->arg_end() && "Argument mismatch!"); AI->setName(Arg->getName() + ".coerce"); CreateCoercedStore(AI++, Ptr, /*DestIsVolatile=*/false, *this); } // Match to what EmitParmDecl is expecting for this type. if (!CodeGenFunction::hasAggregateLLVMType(Ty)) { V = EmitLoadOfScalar(V, false, AlignmentToUse, Ty); if (isPromoted) V = emitArgumentDemotion(*this, Arg, V); } EmitParmDecl(*Arg, V, ArgNo); continue; // Skip ++AI increment, already done. } case ABIArgInfo::Expand: { // If this structure was expanded into multiple arguments then // we need to create a temporary and reconstruct it from the // arguments. llvm::Value *Temp = CreateMemTemp(Ty, Arg->getName() + ".addr"); llvm::Function::arg_iterator End = ExpandTypeFromArgs(Ty, MakeAddrLValue(Temp, Ty), AI); EmitParmDecl(*Arg, Temp, ArgNo); // Name the arguments used in expansion and increment AI. unsigned Index = 0; for (; AI != End; ++AI, ++Index) AI->setName(Arg->getName() + "." + llvm::Twine(Index)); continue; } case ABIArgInfo::Ignore: // Initialize the local variable appropriately. if (hasAggregateLLVMType(Ty)) EmitParmDecl(*Arg, CreateMemTemp(Ty), ArgNo); else EmitParmDecl(*Arg, llvm::UndefValue::get(ConvertType(Arg->getType())), ArgNo); // Skip increment, no matching LLVM parameter. continue; } ++AI; } assert(AI == Fn->arg_end() && "Argument mismatch!"); } /// Try to emit a fused autorelease of a return result. static llvm::Value *tryEmitFusedAutoreleaseOfResult(CodeGenFunction &CGF, llvm::Value *result) { // We must be immediately followed the cast. llvm::BasicBlock *BB = CGF.Builder.GetInsertBlock(); if (BB->empty()) return 0; if (&BB->back() != result) return 0; const llvm::Type *resultType = result->getType(); // result is in a BasicBlock and is therefore an Instruction. llvm::Instruction *generator = cast(result); llvm::SmallVector insnsToKill; // Look for: // %generator = bitcast %type1* %generator2 to %type2* while (llvm::BitCastInst *bitcast = dyn_cast(generator)) { // We would have emitted this as a constant if the operand weren't // an Instruction. generator = cast(bitcast->getOperand(0)); // Require the generator to be immediately followed by the cast. if (generator->getNextNode() != bitcast) return 0; insnsToKill.push_back(bitcast); } // Look for: // %generator = call i8* @objc_retain(i8* %originalResult) // or // %generator = call i8* @objc_retainAutoreleasedReturnValue(i8* %originalResult) llvm::CallInst *call = dyn_cast(generator); if (!call) return 0; bool doRetainAutorelease; if (call->getCalledValue() == CGF.CGM.getARCEntrypoints().objc_retain) { doRetainAutorelease = true; } else if (call->getCalledValue() == CGF.CGM.getARCEntrypoints() .objc_retainAutoreleasedReturnValue) { doRetainAutorelease = false; // Look for an inline asm immediately preceding the call and kill it, too. llvm::Instruction *prev = call->getPrevNode(); if (llvm::CallInst *asmCall = dyn_cast_or_null(prev)) if (asmCall->getCalledValue() == CGF.CGM.getARCEntrypoints().retainAutoreleasedReturnValueMarker) insnsToKill.push_back(prev); } else { return 0; } result = call->getArgOperand(0); insnsToKill.push_back(call); // Keep killing bitcasts, for sanity. Note that we no longer care // about precise ordering as long as there's exactly one use. while (llvm::BitCastInst *bitcast = dyn_cast(result)) { if (!bitcast->hasOneUse()) break; insnsToKill.push_back(bitcast); result = bitcast->getOperand(0); } // Delete all the unnecessary instructions, from latest to earliest. for (llvm::SmallVectorImpl::iterator i = insnsToKill.begin(), e = insnsToKill.end(); i != e; ++i) (*i)->eraseFromParent(); // Do the fused retain/autorelease if we were asked to. if (doRetainAutorelease) result = CGF.EmitARCRetainAutoreleaseReturnValue(result); // Cast back to the result type. return CGF.Builder.CreateBitCast(result, resultType); } /// Emit an ARC autorelease of the result of a function. static llvm::Value *emitAutoreleaseOfResult(CodeGenFunction &CGF, llvm::Value *result) { // At -O0, try to emit a fused retain/autorelease. if (CGF.shouldUseFusedARCCalls()) if (llvm::Value *fused = tryEmitFusedAutoreleaseOfResult(CGF, result)) return fused; return CGF.EmitARCAutoreleaseReturnValue(result); } void CodeGenFunction::EmitFunctionEpilog(const CGFunctionInfo &FI) { // Functions with no result always return void. if (ReturnValue == 0) { Builder.CreateRetVoid(); return; } llvm::DebugLoc RetDbgLoc; llvm::Value *RV = 0; QualType RetTy = FI.getReturnType(); const ABIArgInfo &RetAI = FI.getReturnInfo(); switch (RetAI.getKind()) { case ABIArgInfo::Indirect: { unsigned Alignment = getContext().getTypeAlignInChars(RetTy).getQuantity(); if (RetTy->isAnyComplexType()) { ComplexPairTy RT = LoadComplexFromAddr(ReturnValue, false); StoreComplexToAddr(RT, CurFn->arg_begin(), false); } else if (CodeGenFunction::hasAggregateLLVMType(RetTy)) { // Do nothing; aggregrates get evaluated directly into the destination. } else { EmitStoreOfScalar(Builder.CreateLoad(ReturnValue), CurFn->arg_begin(), false, Alignment, RetTy); } break; } case ABIArgInfo::Extend: case ABIArgInfo::Direct: if (RetAI.getCoerceToType() == ConvertType(RetTy) && RetAI.getDirectOffset() == 0) { // The internal return value temp always will have pointer-to-return-type // type, just do a load. // If the instruction right before the insertion point is a store to the // return value, we can elide the load, zap the store, and usually zap the // alloca. llvm::BasicBlock *InsertBB = Builder.GetInsertBlock(); llvm::StoreInst *SI = 0; if (InsertBB->empty() || !(SI = dyn_cast(&InsertBB->back())) || SI->getPointerOperand() != ReturnValue || SI->isVolatile()) { RV = Builder.CreateLoad(ReturnValue); } else { // Get the stored value and nuke the now-dead store. RetDbgLoc = SI->getDebugLoc(); RV = SI->getValueOperand(); SI->eraseFromParent(); // If that was the only use of the return value, nuke it as well now. if (ReturnValue->use_empty() && isa(ReturnValue)) { cast(ReturnValue)->eraseFromParent(); ReturnValue = 0; } } } else { llvm::Value *V = ReturnValue; // If the value is offset in memory, apply the offset now. if (unsigned Offs = RetAI.getDirectOffset()) { V = Builder.CreateBitCast(V, Builder.getInt8PtrTy()); V = Builder.CreateConstGEP1_32(V, Offs); V = Builder.CreateBitCast(V, llvm::PointerType::getUnqual(RetAI.getCoerceToType())); } RV = CreateCoercedLoad(V, RetAI.getCoerceToType(), *this); } // In ARC, end functions that return a retainable type with a call // to objc_autoreleaseReturnValue. if (AutoreleaseResult) { assert(getLangOptions().ObjCAutoRefCount && !FI.isReturnsRetained() && RetTy->isObjCRetainableType()); RV = emitAutoreleaseOfResult(*this, RV); } break; case ABIArgInfo::Ignore: break; case ABIArgInfo::Expand: assert(0 && "Invalid ABI kind for return argument"); } llvm::Instruction *Ret = RV ? Builder.CreateRet(RV) : Builder.CreateRetVoid(); if (!RetDbgLoc.isUnknown()) Ret->setDebugLoc(RetDbgLoc); } void CodeGenFunction::EmitDelegateCallArg(CallArgList &args, const VarDecl *param) { // StartFunction converted the ABI-lowered parameter(s) into a // local alloca. We need to turn that into an r-value suitable // for EmitCall. llvm::Value *local = GetAddrOfLocalVar(param); QualType type = param->getType(); // For the most part, we just need to load the alloca, except: // 1) aggregate r-values are actually pointers to temporaries, and // 2) references to aggregates are pointers directly to the aggregate. // I don't know why references to non-aggregates are different here. if (const ReferenceType *ref = type->getAs()) { if (hasAggregateLLVMType(ref->getPointeeType())) return args.add(RValue::getAggregate(local), type); // Locals which are references to scalars are represented // with allocas holding the pointer. return args.add(RValue::get(Builder.CreateLoad(local)), type); } if (type->isAnyComplexType()) { ComplexPairTy complex = LoadComplexFromAddr(local, /*volatile*/ false); return args.add(RValue::getComplex(complex), type); } if (hasAggregateLLVMType(type)) return args.add(RValue::getAggregate(local), type); unsigned alignment = getContext().getDeclAlign(param).getQuantity(); llvm::Value *value = EmitLoadOfScalar(local, false, alignment, type); return args.add(RValue::get(value), type); } static bool isProvablyNull(llvm::Value *addr) { return isa(addr); } static bool isProvablyNonNull(llvm::Value *addr) { return isa(addr); } /// Emit the actual writing-back of a writeback. static void emitWriteback(CodeGenFunction &CGF, const CallArgList::Writeback &writeback) { llvm::Value *srcAddr = writeback.Address; assert(!isProvablyNull(srcAddr) && "shouldn't have writeback for provably null argument"); llvm::BasicBlock *contBB = 0; // If the argument wasn't provably non-null, we need to null check // before doing the store. bool provablyNonNull = isProvablyNonNull(srcAddr); if (!provablyNonNull) { llvm::BasicBlock *writebackBB = CGF.createBasicBlock("icr.writeback"); contBB = CGF.createBasicBlock("icr.done"); llvm::Value *isNull = CGF.Builder.CreateIsNull(srcAddr, "icr.isnull"); CGF.Builder.CreateCondBr(isNull, contBB, writebackBB); CGF.EmitBlock(writebackBB); } // Load the value to writeback. llvm::Value *value = CGF.Builder.CreateLoad(writeback.Temporary); // Cast it back, in case we're writing an id to a Foo* or something. value = CGF.Builder.CreateBitCast(value, cast(srcAddr->getType())->getElementType(), "icr.writeback-cast"); // Perform the writeback. QualType srcAddrType = writeback.AddressType; CGF.EmitStoreThroughLValue(RValue::get(value), CGF.MakeAddrLValue(srcAddr, srcAddrType)); // Jump to the continuation block. if (!provablyNonNull) CGF.EmitBlock(contBB); } static void emitWritebacks(CodeGenFunction &CGF, const CallArgList &args) { for (CallArgList::writeback_iterator i = args.writeback_begin(), e = args.writeback_end(); i != e; ++i) emitWriteback(CGF, *i); } /// Emit an argument that's being passed call-by-writeback. That is, /// we are passing the address of static void emitWritebackArg(CodeGenFunction &CGF, CallArgList &args, const ObjCIndirectCopyRestoreExpr *CRE) { llvm::Value *srcAddr = CGF.EmitScalarExpr(CRE->getSubExpr()); // The dest and src types don't necessarily match in LLVM terms // because of the crazy ObjC compatibility rules. const llvm::PointerType *destType = cast(CGF.ConvertType(CRE->getType())); // If the address is a constant null, just pass the appropriate null. if (isProvablyNull(srcAddr)) { args.add(RValue::get(llvm::ConstantPointerNull::get(destType)), CRE->getType()); return; } QualType srcAddrType = CRE->getSubExpr()->getType()->castAs()->getPointeeType(); // Create the temporary. llvm::Value *temp = CGF.CreateTempAlloca(destType->getElementType(), "icr.temp"); // Zero-initialize it if we're not doing a copy-initialization. bool shouldCopy = CRE->shouldCopy(); if (!shouldCopy) { llvm::Value *null = llvm::ConstantPointerNull::get( cast(destType->getElementType())); CGF.Builder.CreateStore(null, temp); } llvm::BasicBlock *contBB = 0; // If the address is *not* known to be non-null, we need to switch. llvm::Value *finalArgument; bool provablyNonNull = isProvablyNonNull(srcAddr); if (provablyNonNull) { finalArgument = temp; } else { llvm::Value *isNull = CGF.Builder.CreateIsNull(srcAddr, "icr.isnull"); finalArgument = CGF.Builder.CreateSelect(isNull, llvm::ConstantPointerNull::get(destType), temp, "icr.argument"); // If we need to copy, then the load has to be conditional, which // means we need control flow. if (shouldCopy) { contBB = CGF.createBasicBlock("icr.cont"); llvm::BasicBlock *copyBB = CGF.createBasicBlock("icr.copy"); CGF.Builder.CreateCondBr(isNull, contBB, copyBB); CGF.EmitBlock(copyBB); } } // Perform a copy if necessary. if (shouldCopy) { LValue srcLV = CGF.MakeAddrLValue(srcAddr, srcAddrType); RValue srcRV = CGF.EmitLoadOfLValue(srcLV); assert(srcRV.isScalar()); llvm::Value *src = srcRV.getScalarVal(); src = CGF.Builder.CreateBitCast(src, destType->getElementType(), "icr.cast"); // Use an ordinary store, not a store-to-lvalue. CGF.Builder.CreateStore(src, temp); } // Finish the control flow if we needed it. if (shouldCopy && !provablyNonNull) CGF.EmitBlock(contBB); args.addWriteback(srcAddr, srcAddrType, temp); args.add(RValue::get(finalArgument), CRE->getType()); } void CodeGenFunction::EmitCallArg(CallArgList &args, const Expr *E, QualType type) { if (const ObjCIndirectCopyRestoreExpr *CRE = dyn_cast(E)) { assert(getContext().getLangOptions().ObjCAutoRefCount); assert(getContext().hasSameType(E->getType(), type)); return emitWritebackArg(*this, args, CRE); } if (type->isReferenceType()) return args.add(EmitReferenceBindingToExpr(E, /*InitializedDecl=*/0), type); if (hasAggregateLLVMType(type) && !E->getType()->isAnyComplexType() && isa(E) && cast(E)->getCastKind() == CK_LValueToRValue) { LValue L = EmitLValue(cast(E)->getSubExpr()); assert(L.isSimple()); args.add(RValue::getAggregate(L.getAddress(), L.isVolatileQualified()), type, /*NeedsCopy*/true); return; } args.add(EmitAnyExprToTemp(E), type); } /// Emits a call or invoke instruction to the given function, depending /// on the current state of the EH stack. llvm::CallSite CodeGenFunction::EmitCallOrInvoke(llvm::Value *Callee, llvm::ArrayRef Args, const llvm::Twine &Name) { llvm::BasicBlock *InvokeDest = getInvokeDest(); if (!InvokeDest) return Builder.CreateCall(Callee, Args, Name); llvm::BasicBlock *ContBB = createBasicBlock("invoke.cont"); llvm::InvokeInst *Invoke = Builder.CreateInvoke(Callee, ContBB, InvokeDest, Args, Name); EmitBlock(ContBB); return Invoke; } llvm::CallSite CodeGenFunction::EmitCallOrInvoke(llvm::Value *Callee, const llvm::Twine &Name) { return EmitCallOrInvoke(Callee, llvm::ArrayRef(), Name); } static void checkArgMatches(llvm::Value *Elt, unsigned &ArgNo, llvm::FunctionType *FTy) { if (ArgNo < FTy->getNumParams()) assert(Elt->getType() == FTy->getParamType(ArgNo)); else assert(FTy->isVarArg()); ++ArgNo; } void CodeGenFunction::ExpandTypeToArgs(QualType Ty, RValue RV, llvm::SmallVector &Args, llvm::FunctionType *IRFuncTy) { const RecordType *RT = Ty->getAsStructureType(); assert(RT && "Can only expand structure types."); RecordDecl *RD = RT->getDecl(); assert(RV.isAggregate() && "Unexpected rvalue during struct expansion"); llvm::Value *Addr = RV.getAggregateAddr(); for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); i != e; ++i) { FieldDecl *FD = *i; QualType FT = FD->getType(); // FIXME: What are the right qualifiers here? LValue LV = EmitLValueForField(Addr, FD, 0); if (CodeGenFunction::hasAggregateLLVMType(FT)) { ExpandTypeToArgs(FT, RValue::getAggregate(LV.getAddress()), Args, IRFuncTy); continue; } RValue RV = EmitLoadOfLValue(LV); assert(RV.isScalar() && "Unexpected non-scalar rvalue during struct expansion."); // Insert a bitcast as needed. llvm::Value *V = RV.getScalarVal(); if (Args.size() < IRFuncTy->getNumParams() && V->getType() != IRFuncTy->getParamType(Args.size())) V = Builder.CreateBitCast(V, IRFuncTy->getParamType(Args.size())); Args.push_back(V); } } RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo, llvm::Value *Callee, ReturnValueSlot ReturnValue, const CallArgList &CallArgs, const Decl *TargetDecl, llvm::Instruction **callOrInvoke) { // FIXME: We no longer need the types from CallArgs; lift up and simplify. llvm::SmallVector Args; // Handle struct-return functions by passing a pointer to the // location that we would like to return into. QualType RetTy = CallInfo.getReturnType(); const ABIArgInfo &RetAI = CallInfo.getReturnInfo(); // IRArgNo - Keep track of the argument number in the callee we're looking at. unsigned IRArgNo = 0; llvm::FunctionType *IRFuncTy = cast( cast(Callee->getType())->getElementType()); // If the call returns a temporary with struct return, create a temporary // alloca to hold the result, unless one is given to us. if (CGM.ReturnTypeUsesSRet(CallInfo)) { llvm::Value *Value = ReturnValue.getValue(); if (!Value) Value = CreateMemTemp(RetTy); Args.push_back(Value); checkArgMatches(Value, IRArgNo, IRFuncTy); } assert(CallInfo.arg_size() == CallArgs.size() && "Mismatch between function signature & arguments."); CGFunctionInfo::const_arg_iterator info_it = CallInfo.arg_begin(); for (CallArgList::const_iterator I = CallArgs.begin(), E = CallArgs.end(); I != E; ++I, ++info_it) { const ABIArgInfo &ArgInfo = info_it->info; RValue RV = I->RV; unsigned TypeAlign = getContext().getTypeAlignInChars(I->Ty).getQuantity(); switch (ArgInfo.getKind()) { case ABIArgInfo::Indirect: { if (RV.isScalar() || RV.isComplex()) { // Make a temporary alloca to pass the argument. llvm::AllocaInst *AI = CreateMemTemp(I->Ty); if (ArgInfo.getIndirectAlign() > AI->getAlignment()) AI->setAlignment(ArgInfo.getIndirectAlign()); Args.push_back(AI); if (RV.isScalar()) EmitStoreOfScalar(RV.getScalarVal(), Args.back(), false, TypeAlign, I->Ty); else StoreComplexToAddr(RV.getComplexVal(), Args.back(), false); // Validate argument match. checkArgMatches(AI, IRArgNo, IRFuncTy); } else { // We want to avoid creating an unnecessary temporary+copy here; // however, we need one in two cases: // 1. If the argument is not byval, and we are required to copy the // source. (This case doesn't occur on any common architecture.) // 2. If the argument is byval, RV is not sufficiently aligned, and // we cannot force it to be sufficiently aligned. llvm::Value *Addr = RV.getAggregateAddr(); unsigned Align = ArgInfo.getIndirectAlign(); const llvm::TargetData *TD = &CGM.getTargetData(); if ((!ArgInfo.getIndirectByVal() && I->NeedsCopy) || (ArgInfo.getIndirectByVal() && TypeAlign < Align && llvm::getOrEnforceKnownAlignment(Addr, Align, TD) < Align)) { // Create an aligned temporary, and copy to it. llvm::AllocaInst *AI = CreateMemTemp(I->Ty); if (Align > AI->getAlignment()) AI->setAlignment(Align); Args.push_back(AI); EmitAggregateCopy(AI, Addr, I->Ty, RV.isVolatileQualified()); // Validate argument match. checkArgMatches(AI, IRArgNo, IRFuncTy); } else { // Skip the extra memcpy call. Args.push_back(Addr); // Validate argument match. checkArgMatches(Addr, IRArgNo, IRFuncTy); } } break; } case ABIArgInfo::Ignore: break; case ABIArgInfo::Extend: case ABIArgInfo::Direct: { if (!isa(ArgInfo.getCoerceToType()) && ArgInfo.getCoerceToType() == ConvertType(info_it->type) && ArgInfo.getDirectOffset() == 0) { llvm::Value *V; if (RV.isScalar()) V = RV.getScalarVal(); else V = Builder.CreateLoad(RV.getAggregateAddr()); // If the argument doesn't match, perform a bitcast to coerce it. This // can happen due to trivial type mismatches. if (IRArgNo < IRFuncTy->getNumParams() && V->getType() != IRFuncTy->getParamType(IRArgNo)) V = Builder.CreateBitCast(V, IRFuncTy->getParamType(IRArgNo)); Args.push_back(V); checkArgMatches(V, IRArgNo, IRFuncTy); break; } // FIXME: Avoid the conversion through memory if possible. llvm::Value *SrcPtr; if (RV.isScalar()) { SrcPtr = CreateMemTemp(I->Ty, "coerce"); EmitStoreOfScalar(RV.getScalarVal(), SrcPtr, false, TypeAlign, I->Ty); } else if (RV.isComplex()) { SrcPtr = CreateMemTemp(I->Ty, "coerce"); StoreComplexToAddr(RV.getComplexVal(), SrcPtr, false); } else SrcPtr = RV.getAggregateAddr(); // If the value is offset in memory, apply the offset now. if (unsigned Offs = ArgInfo.getDirectOffset()) { SrcPtr = Builder.CreateBitCast(SrcPtr, Builder.getInt8PtrTy()); SrcPtr = Builder.CreateConstGEP1_32(SrcPtr, Offs); SrcPtr = Builder.CreateBitCast(SrcPtr, llvm::PointerType::getUnqual(ArgInfo.getCoerceToType())); } // If the coerce-to type is a first class aggregate, we flatten it and // pass the elements. Either way is semantically identical, but fast-isel // and the optimizer generally likes scalar values better than FCAs. if (const llvm::StructType *STy = dyn_cast(ArgInfo.getCoerceToType())) { SrcPtr = Builder.CreateBitCast(SrcPtr, llvm::PointerType::getUnqual(STy)); for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { llvm::Value *EltPtr = Builder.CreateConstGEP2_32(SrcPtr, 0, i); llvm::LoadInst *LI = Builder.CreateLoad(EltPtr); // We don't know what we're loading from. LI->setAlignment(1); Args.push_back(LI); // Validate argument match. checkArgMatches(LI, IRArgNo, IRFuncTy); } } else { // In the simple case, just pass the coerced loaded value. Args.push_back(CreateCoercedLoad(SrcPtr, ArgInfo.getCoerceToType(), *this)); // Validate argument match. checkArgMatches(Args.back(), IRArgNo, IRFuncTy); } break; } case ABIArgInfo::Expand: ExpandTypeToArgs(I->Ty, RV, Args, IRFuncTy); IRArgNo = Args.size(); break; } } // If the callee is a bitcast of a function to a varargs pointer to function // type, check to see if we can remove the bitcast. This handles some cases // with unprototyped functions. if (llvm::ConstantExpr *CE = dyn_cast(Callee)) if (llvm::Function *CalleeF = dyn_cast(CE->getOperand(0))) { const llvm::PointerType *CurPT=cast(Callee->getType()); const llvm::FunctionType *CurFT = cast(CurPT->getElementType()); const llvm::FunctionType *ActualFT = CalleeF->getFunctionType(); if (CE->getOpcode() == llvm::Instruction::BitCast && ActualFT->getReturnType() == CurFT->getReturnType() && ActualFT->getNumParams() == CurFT->getNumParams() && ActualFT->getNumParams() == Args.size() && (CurFT->isVarArg() || !ActualFT->isVarArg())) { bool ArgsMatch = true; for (unsigned i = 0, e = ActualFT->getNumParams(); i != e; ++i) if (ActualFT->getParamType(i) != CurFT->getParamType(i)) { ArgsMatch = false; break; } // Strip the cast if we can get away with it. This is a nice cleanup, // but also allows us to inline the function at -O0 if it is marked // always_inline. if (ArgsMatch) Callee = CalleeF; } } unsigned CallingConv; CodeGen::AttributeListType AttributeList; CGM.ConstructAttributeList(CallInfo, TargetDecl, AttributeList, CallingConv); llvm::AttrListPtr Attrs = llvm::AttrListPtr::get(AttributeList.begin(), AttributeList.end()); llvm::BasicBlock *InvokeDest = 0; if (!(Attrs.getFnAttributes() & llvm::Attribute::NoUnwind)) InvokeDest = getInvokeDest(); llvm::CallSite CS; if (!InvokeDest) { CS = Builder.CreateCall(Callee, Args); } else { llvm::BasicBlock *Cont = createBasicBlock("invoke.cont"); CS = Builder.CreateInvoke(Callee, Cont, InvokeDest, Args); EmitBlock(Cont); } if (callOrInvoke) *callOrInvoke = CS.getInstruction(); CS.setAttributes(Attrs); CS.setCallingConv(static_cast(CallingConv)); // If the call doesn't return, finish the basic block and clear the // insertion point; this allows the rest of IRgen to discard // unreachable code. if (CS.doesNotReturn()) { Builder.CreateUnreachable(); Builder.ClearInsertionPoint(); // FIXME: For now, emit a dummy basic block because expr emitters in // generally are not ready to handle emitting expressions at unreachable // points. EnsureInsertPoint(); // Return a reasonable RValue. return GetUndefRValue(RetTy); } llvm::Instruction *CI = CS.getInstruction(); if (Builder.isNamePreserving() && !CI->getType()->isVoidTy()) CI->setName("call"); // Emit any writebacks immediately. Arguably this should happen // after any return-value munging. if (CallArgs.hasWritebacks()) emitWritebacks(*this, CallArgs); switch (RetAI.getKind()) { case ABIArgInfo::Indirect: { unsigned Alignment = getContext().getTypeAlignInChars(RetTy).getQuantity(); if (RetTy->isAnyComplexType()) return RValue::getComplex(LoadComplexFromAddr(Args[0], false)); if (CodeGenFunction::hasAggregateLLVMType(RetTy)) return RValue::getAggregate(Args[0]); return RValue::get(EmitLoadOfScalar(Args[0], false, Alignment, RetTy)); } case ABIArgInfo::Ignore: // If we are ignoring an argument that had a result, make sure to // construct the appropriate return value for our caller. return GetUndefRValue(RetTy); case ABIArgInfo::Extend: case ABIArgInfo::Direct: { llvm::Type *RetIRTy = ConvertType(RetTy); if (RetAI.getCoerceToType() == RetIRTy && RetAI.getDirectOffset() == 0) { if (RetTy->isAnyComplexType()) { llvm::Value *Real = Builder.CreateExtractValue(CI, 0); llvm::Value *Imag = Builder.CreateExtractValue(CI, 1); return RValue::getComplex(std::make_pair(Real, Imag)); } if (CodeGenFunction::hasAggregateLLVMType(RetTy)) { llvm::Value *DestPtr = ReturnValue.getValue(); bool DestIsVolatile = ReturnValue.isVolatile(); if (!DestPtr) { DestPtr = CreateMemTemp(RetTy, "agg.tmp"); DestIsVolatile = false; } BuildAggStore(*this, CI, DestPtr, DestIsVolatile, false); return RValue::getAggregate(DestPtr); } // If the argument doesn't match, perform a bitcast to coerce it. This // can happen due to trivial type mismatches. llvm::Value *V = CI; if (V->getType() != RetIRTy) V = Builder.CreateBitCast(V, RetIRTy); return RValue::get(V); } llvm::Value *DestPtr = ReturnValue.getValue(); bool DestIsVolatile = ReturnValue.isVolatile(); if (!DestPtr) { DestPtr = CreateMemTemp(RetTy, "coerce"); DestIsVolatile = false; } // If the value is offset in memory, apply the offset now. llvm::Value *StorePtr = DestPtr; if (unsigned Offs = RetAI.getDirectOffset()) { StorePtr = Builder.CreateBitCast(StorePtr, Builder.getInt8PtrTy()); StorePtr = Builder.CreateConstGEP1_32(StorePtr, Offs); StorePtr = Builder.CreateBitCast(StorePtr, llvm::PointerType::getUnqual(RetAI.getCoerceToType())); } CreateCoercedStore(CI, StorePtr, DestIsVolatile, *this); unsigned Alignment = getContext().getTypeAlignInChars(RetTy).getQuantity(); if (RetTy->isAnyComplexType()) return RValue::getComplex(LoadComplexFromAddr(DestPtr, false)); if (CodeGenFunction::hasAggregateLLVMType(RetTy)) return RValue::getAggregate(DestPtr); return RValue::get(EmitLoadOfScalar(DestPtr, false, Alignment, RetTy)); } case ABIArgInfo::Expand: assert(0 && "Invalid ABI kind for return argument"); } assert(0 && "Unhandled ABIArgInfo::Kind"); return RValue::get(0); } /* VarArg handling */ llvm::Value *CodeGenFunction::EmitVAArg(llvm::Value *VAListAddr, QualType Ty) { return CGM.getTypes().getABIInfo().EmitVAArg(VAListAddr, Ty, *this); }