//===--- CGCall.cpp - Encapsulate calling convention details --------------===// // // 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 "ABIInfo.h" #include "CGCXXABI.h" #include "CodeGenFunction.h" #include "CodeGenModule.h" #include "TargetInfo.h" #include "clang/AST/Decl.h" #include "clang/AST/DeclCXX.h" #include "clang/AST/DeclObjC.h" #include "clang/Basic/TargetInfo.h" #include "clang/CodeGen/CGFunctionInfo.h" #include "clang/Frontend/CodeGenOptions.h" #include "llvm/ADT/StringExtras.h" #include "llvm/IR/Attributes.h" #include "llvm/IR/CallSite.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/InlineAsm.h" #include "llvm/IR/Intrinsics.h" #include "llvm/IR/IntrinsicInst.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_X86_64Win64: return llvm::CallingConv::X86_64_Win64; case CC_X86_64SysV: return llvm::CallingConv::X86_64_SysV; case CC_AAPCS: return llvm::CallingConv::ARM_AAPCS; case CC_AAPCS_VFP: return llvm::CallingConv::ARM_AAPCS_VFP; case CC_IntelOclBicc: return llvm::CallingConv::Intel_OCL_BI; // TODO: Add support for __pascal to LLVM. case CC_X86Pascal: return llvm::CallingConv::C; // TODO: Add support for __vectorcall to LLVM. case CC_X86VectorCall: return llvm::CallingConv::X86_VectorCall; case CC_SpirFunction: return llvm::CallingConv::SPIR_FUNC; case CC_SpirKernel: return llvm::CallingConv::SPIR_KERNEL; } } /// 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(); } /// Arrange the argument and result information for a value of the given /// unprototyped freestanding function type. const CGFunctionInfo & CodeGenTypes::arrangeFreeFunctionType(CanQual FTNP) { // When translating an unprototyped function type, always use a // variadic type. return arrangeLLVMFunctionInfo(FTNP->getReturnType().getUnqualifiedType(), /*instanceMethod=*/false, /*chainCall=*/false, None, FTNP->getExtInfo(), RequiredArgs(0)); } /// Arrange the LLVM function layout for a value of the given function /// type, on top of any implicit parameters already stored. static const CGFunctionInfo & arrangeLLVMFunctionInfo(CodeGenTypes &CGT, bool instanceMethod, SmallVectorImpl &prefix, CanQual FTP) { RequiredArgs required = RequiredArgs::forPrototypePlus(FTP, prefix.size()); // FIXME: Kill copy. prefix.append(FTP->param_type_begin(), FTP->param_type_end()); CanQualType resultType = FTP->getReturnType().getUnqualifiedType(); return CGT.arrangeLLVMFunctionInfo(resultType, instanceMethod, /*chainCall=*/false, prefix, FTP->getExtInfo(), required); } /// Arrange the argument and result information for a value of the /// given freestanding function type. const CGFunctionInfo & CodeGenTypes::arrangeFreeFunctionType(CanQual FTP) { SmallVector argTypes; return ::arrangeLLVMFunctionInfo(*this, /*instanceMethod=*/false, argTypes, FTP); } static CallingConv getCallingConventionForDecl(const Decl *D, bool IsWindows) { // 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_X86VectorCall; if (D->hasAttr()) return CC_X86Pascal; if (PcsAttr *PCS = D->getAttr()) return (PCS->getPCS() == PcsAttr::AAPCS ? CC_AAPCS : CC_AAPCS_VFP); if (D->hasAttr()) return CC_IntelOclBicc; if (D->hasAttr()) return IsWindows ? CC_C : CC_X86_64Win64; if (D->hasAttr()) return IsWindows ? CC_X86_64SysV : CC_C; return CC_C; } /// Arrange the argument and result information for a call to an /// unknown C++ non-static member function of the given abstract type. /// (Zero value of RD means we don't have any meaningful "this" argument type, /// so fall back to a generic pointer type). /// The member function must be an ordinary function, i.e. not a /// constructor or destructor. const CGFunctionInfo & CodeGenTypes::arrangeCXXMethodType(const CXXRecordDecl *RD, const FunctionProtoType *FTP) { SmallVector argTypes; // Add the 'this' pointer. if (RD) argTypes.push_back(GetThisType(Context, RD)); else argTypes.push_back(Context.VoidPtrTy); return ::arrangeLLVMFunctionInfo( *this, true, argTypes, FTP->getCanonicalTypeUnqualified().getAs()); } /// Arrange the argument and result information for a declaration or /// definition of the given C++ non-static member function. The /// member function must be an ordinary function, i.e. not a /// constructor or destructor. const CGFunctionInfo & CodeGenTypes::arrangeCXXMethodDeclaration(const CXXMethodDecl *MD) { assert(!isa(MD) && "wrong method for constructors!"); assert(!isa(MD) && "wrong method for destructors!"); CanQual prototype = GetFormalType(MD); if (MD->isInstance()) { // The abstract case is perfectly fine. const CXXRecordDecl *ThisType = TheCXXABI.getThisArgumentTypeForMethod(MD); return arrangeCXXMethodType(ThisType, prototype.getTypePtr()); } return arrangeFreeFunctionType(prototype); } const CGFunctionInfo & CodeGenTypes::arrangeCXXStructorDeclaration(const CXXMethodDecl *MD, StructorType Type) { SmallVector argTypes; argTypes.push_back(GetThisType(Context, MD->getParent())); GlobalDecl GD; if (auto *CD = dyn_cast(MD)) { GD = GlobalDecl(CD, toCXXCtorType(Type)); } else { auto *DD = dyn_cast(MD); GD = GlobalDecl(DD, toCXXDtorType(Type)); } CanQual FTP = GetFormalType(MD); // Add the formal parameters. argTypes.append(FTP->param_type_begin(), FTP->param_type_end()); TheCXXABI.buildStructorSignature(MD, Type, argTypes); RequiredArgs required = (MD->isVariadic() ? RequiredArgs(argTypes.size()) : RequiredArgs::All); FunctionType::ExtInfo extInfo = FTP->getExtInfo(); CanQualType resultType = TheCXXABI.HasThisReturn(GD) ? argTypes.front() : TheCXXABI.hasMostDerivedReturn(GD) ? CGM.getContext().VoidPtrTy : Context.VoidTy; return arrangeLLVMFunctionInfo(resultType, /*instanceMethod=*/true, /*chainCall=*/false, argTypes, extInfo, required); } /// Arrange a call to a C++ method, passing the given arguments. const CGFunctionInfo & CodeGenTypes::arrangeCXXConstructorCall(const CallArgList &args, const CXXConstructorDecl *D, CXXCtorType CtorKind, unsigned ExtraArgs) { // FIXME: Kill copy. SmallVector ArgTypes; for (const auto &Arg : args) ArgTypes.push_back(Context.getCanonicalParamType(Arg.Ty)); CanQual FPT = GetFormalType(D); RequiredArgs Required = RequiredArgs::forPrototypePlus(FPT, 1 + ExtraArgs); GlobalDecl GD(D, CtorKind); CanQualType ResultType = TheCXXABI.HasThisReturn(GD) ? ArgTypes.front() : TheCXXABI.hasMostDerivedReturn(GD) ? CGM.getContext().VoidPtrTy : Context.VoidTy; FunctionType::ExtInfo Info = FPT->getExtInfo(); return arrangeLLVMFunctionInfo(ResultType, /*instanceMethod=*/true, /*chainCall=*/false, ArgTypes, Info, Required); } /// Arrange the argument and result information for the declaration or /// definition of the given function. const CGFunctionInfo & CodeGenTypes::arrangeFunctionDeclaration(const FunctionDecl *FD) { if (const CXXMethodDecl *MD = dyn_cast(FD)) if (MD->isInstance()) return arrangeCXXMethodDeclaration(MD); CanQualType FTy = FD->getType()->getCanonicalTypeUnqualified(); assert(isa(FTy)); // When declaring a function without a prototype, always use a // non-variadic type. if (isa(FTy)) { CanQual noProto = FTy.getAs(); return arrangeLLVMFunctionInfo( noProto->getReturnType(), /*instanceMethod=*/false, /*chainCall=*/false, None, noProto->getExtInfo(), RequiredArgs::All); } assert(isa(FTy)); return arrangeFreeFunctionType(FTy.getAs()); } /// Arrange the argument and result information for the declaration or /// definition of an Objective-C method. const CGFunctionInfo & CodeGenTypes::arrangeObjCMethodDeclaration(const ObjCMethodDecl *MD) { // It happens that this is the same as a call with no optional // arguments, except also using the formal 'self' type. return arrangeObjCMessageSendSignature(MD, MD->getSelfDecl()->getType()); } /// Arrange the argument and result information for the function type /// through which to perform a send to the given Objective-C method, /// using the given receiver type. The receiver type is not always /// the 'self' type of the method or even an Objective-C pointer type. /// This is *not* the right method for actually performing such a /// message send, due to the possibility of optional arguments. const CGFunctionInfo & CodeGenTypes::arrangeObjCMessageSendSignature(const ObjCMethodDecl *MD, QualType receiverType) { SmallVector argTys; argTys.push_back(Context.getCanonicalParamType(receiverType)); argTys.push_back(Context.getCanonicalParamType(Context.getObjCSelType())); // FIXME: Kill copy? for (const auto *I : MD->params()) { argTys.push_back(Context.getCanonicalParamType(I->getType())); } FunctionType::ExtInfo einfo; bool IsWindows = getContext().getTargetInfo().getTriple().isOSWindows(); einfo = einfo.withCallingConv(getCallingConventionForDecl(MD, IsWindows)); if (getContext().getLangOpts().ObjCAutoRefCount && MD->hasAttr()) einfo = einfo.withProducesResult(true); RequiredArgs required = (MD->isVariadic() ? RequiredArgs(argTys.size()) : RequiredArgs::All); return arrangeLLVMFunctionInfo( GetReturnType(MD->getReturnType()), /*instanceMethod=*/false, /*chainCall=*/false, argTys, einfo, required); } const CGFunctionInfo & CodeGenTypes::arrangeGlobalDeclaration(GlobalDecl GD) { // FIXME: Do we need to handle ObjCMethodDecl? const FunctionDecl *FD = cast(GD.getDecl()); if (const CXXConstructorDecl *CD = dyn_cast(FD)) return arrangeCXXStructorDeclaration(CD, getFromCtorType(GD.getCtorType())); if (const CXXDestructorDecl *DD = dyn_cast(FD)) return arrangeCXXStructorDeclaration(DD, getFromDtorType(GD.getDtorType())); return arrangeFunctionDeclaration(FD); } /// Arrange a thunk that takes 'this' as the first parameter followed by /// varargs. Return a void pointer, regardless of the actual return type. /// The body of the thunk will end in a musttail call to a function of the /// correct type, and the caller will bitcast the function to the correct /// prototype. const CGFunctionInfo & CodeGenTypes::arrangeMSMemberPointerThunk(const CXXMethodDecl *MD) { assert(MD->isVirtual() && "only virtual memptrs have thunks"); CanQual FTP = GetFormalType(MD); CanQualType ArgTys[] = { GetThisType(Context, MD->getParent()) }; return arrangeLLVMFunctionInfo(Context.VoidTy, /*instanceMethod=*/false, /*chainCall=*/false, ArgTys, FTP->getExtInfo(), RequiredArgs(1)); } const CGFunctionInfo & CodeGenTypes::arrangeMSCtorClosure(const CXXConstructorDecl *CD, CXXCtorType CT) { assert(CT == Ctor_CopyingClosure || CT == Ctor_DefaultClosure); CanQual FTP = GetFormalType(CD); SmallVector ArgTys; const CXXRecordDecl *RD = CD->getParent(); ArgTys.push_back(GetThisType(Context, RD)); if (CT == Ctor_CopyingClosure) ArgTys.push_back(*FTP->param_type_begin()); if (RD->getNumVBases() > 0) ArgTys.push_back(Context.IntTy); CallingConv CC = Context.getDefaultCallingConvention( /*IsVariadic=*/false, /*IsCXXMethod=*/true); return arrangeLLVMFunctionInfo(Context.VoidTy, /*instanceMethod=*/true, /*chainCall=*/false, ArgTys, FunctionType::ExtInfo(CC), RequiredArgs::All); } /// Arrange a call as unto a free function, except possibly with an /// additional number of formal parameters considered required. static const CGFunctionInfo & arrangeFreeFunctionLikeCall(CodeGenTypes &CGT, CodeGenModule &CGM, const CallArgList &args, const FunctionType *fnType, unsigned numExtraRequiredArgs, bool chainCall) { assert(args.size() >= numExtraRequiredArgs); // In most cases, there are no optional arguments. RequiredArgs required = RequiredArgs::All; // If we have a variadic prototype, the required arguments are the // extra prefix plus the arguments in the prototype. if (const FunctionProtoType *proto = dyn_cast(fnType)) { if (proto->isVariadic()) required = RequiredArgs(proto->getNumParams() + numExtraRequiredArgs); // If we don't have a prototype at all, but we're supposed to // explicitly use the variadic convention for unprototyped calls, // treat all of the arguments as required but preserve the nominal // possibility of variadics. } else if (CGM.getTargetCodeGenInfo() .isNoProtoCallVariadic(args, cast(fnType))) { required = RequiredArgs(args.size()); } // FIXME: Kill copy. SmallVector argTypes; for (const auto &arg : args) argTypes.push_back(CGT.getContext().getCanonicalParamType(arg.Ty)); return CGT.arrangeLLVMFunctionInfo(GetReturnType(fnType->getReturnType()), /*instanceMethod=*/false, chainCall, argTypes, fnType->getExtInfo(), required); } /// Figure out the rules for calling a function with the given formal /// type using the given arguments. The arguments are necessary /// because the function might be unprototyped, in which case it's /// target-dependent in crazy ways. const CGFunctionInfo & CodeGenTypes::arrangeFreeFunctionCall(const CallArgList &args, const FunctionType *fnType, bool chainCall) { return arrangeFreeFunctionLikeCall(*this, CGM, args, fnType, chainCall ? 1 : 0, chainCall); } /// A block function call is essentially a free-function call with an /// extra implicit argument. const CGFunctionInfo & CodeGenTypes::arrangeBlockFunctionCall(const CallArgList &args, const FunctionType *fnType) { return arrangeFreeFunctionLikeCall(*this, CGM, args, fnType, 1, /*chainCall=*/false); } const CGFunctionInfo & CodeGenTypes::arrangeFreeFunctionCall(QualType resultType, const CallArgList &args, FunctionType::ExtInfo info, RequiredArgs required) { // FIXME: Kill copy. SmallVector argTypes; for (const auto &Arg : args) argTypes.push_back(Context.getCanonicalParamType(Arg.Ty)); return arrangeLLVMFunctionInfo( GetReturnType(resultType), /*instanceMethod=*/false, /*chainCall=*/false, argTypes, info, required); } /// Arrange a call to a C++ method, passing the given arguments. const CGFunctionInfo & CodeGenTypes::arrangeCXXMethodCall(const CallArgList &args, const FunctionProtoType *FPT, RequiredArgs required) { // FIXME: Kill copy. SmallVector argTypes; for (const auto &Arg : args) argTypes.push_back(Context.getCanonicalParamType(Arg.Ty)); FunctionType::ExtInfo info = FPT->getExtInfo(); return arrangeLLVMFunctionInfo( GetReturnType(FPT->getReturnType()), /*instanceMethod=*/true, /*chainCall=*/false, argTypes, info, required); } const CGFunctionInfo &CodeGenTypes::arrangeFreeFunctionDeclaration( QualType resultType, const FunctionArgList &args, const FunctionType::ExtInfo &info, bool isVariadic) { // FIXME: Kill copy. SmallVector argTypes; for (auto Arg : args) argTypes.push_back(Context.getCanonicalParamType(Arg->getType())); RequiredArgs required = (isVariadic ? RequiredArgs(args.size()) : RequiredArgs::All); return arrangeLLVMFunctionInfo( GetReturnType(resultType), /*instanceMethod=*/false, /*chainCall=*/false, argTypes, info, required); } const CGFunctionInfo &CodeGenTypes::arrangeNullaryFunction() { return arrangeLLVMFunctionInfo( getContext().VoidTy, /*instanceMethod=*/false, /*chainCall=*/false, None, FunctionType::ExtInfo(), RequiredArgs::All); } /// Arrange the argument and result information for an abstract value /// of a given function type. This is the method which all of the /// above functions ultimately defer to. const CGFunctionInfo & CodeGenTypes::arrangeLLVMFunctionInfo(CanQualType resultType, bool instanceMethod, bool chainCall, ArrayRef argTypes, FunctionType::ExtInfo info, RequiredArgs required) { assert(std::all_of(argTypes.begin(), argTypes.end(), std::mem_fun_ref(&CanQualType::isCanonicalAsParam))); unsigned CC = ClangCallConvToLLVMCallConv(info.getCC()); // Lookup or create unique function info. llvm::FoldingSetNodeID ID; CGFunctionInfo::Profile(ID, instanceMethod, chainCall, info, required, resultType, argTypes); void *insertPos = nullptr; CGFunctionInfo *FI = FunctionInfos.FindNodeOrInsertPos(ID, insertPos); if (FI) return *FI; // Construct the function info. We co-allocate the ArgInfos. FI = CGFunctionInfo::create(CC, instanceMethod, chainCall, info, resultType, argTypes, required); FunctionInfos.InsertNode(FI, insertPos); bool inserted = FunctionsBeingProcessed.insert(FI).second; (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() == nullptr) retInfo.setCoerceToType(ConvertType(FI->getReturnType())); for (auto &I : FI->arguments()) if (I.info.canHaveCoerceToType() && I.info.getCoerceToType() == nullptr) I.info.setCoerceToType(ConvertType(I.type)); bool erased = FunctionsBeingProcessed.erase(FI); (void)erased; assert(erased && "Not in set?"); return *FI; } CGFunctionInfo *CGFunctionInfo::create(unsigned llvmCC, bool instanceMethod, bool chainCall, const FunctionType::ExtInfo &info, CanQualType resultType, ArrayRef argTypes, RequiredArgs required) { void *buffer = operator new(sizeof(CGFunctionInfo) + sizeof(ArgInfo) * (argTypes.size() + 1)); CGFunctionInfo *FI = new(buffer) CGFunctionInfo(); FI->CallingConvention = llvmCC; FI->EffectiveCallingConvention = llvmCC; FI->ASTCallingConvention = info.getCC(); FI->InstanceMethod = instanceMethod; FI->ChainCall = chainCall; FI->NoReturn = info.getNoReturn(); FI->ReturnsRetained = info.getProducesResult(); FI->Required = required; FI->HasRegParm = info.getHasRegParm(); FI->RegParm = info.getRegParm(); FI->ArgStruct = nullptr; FI->NumArgs = argTypes.size(); FI->getArgsBuffer()[0].type = resultType; for (unsigned i = 0, e = argTypes.size(); i != e; ++i) FI->getArgsBuffer()[i + 1].type = argTypes[i]; return FI; } /***/ namespace { // ABIArgInfo::Expand implementation. // Specifies the way QualType passed as ABIArgInfo::Expand is expanded. struct TypeExpansion { enum TypeExpansionKind { // Elements of constant arrays are expanded recursively. TEK_ConstantArray, // Record fields are expanded recursively (but if record is a union, only // the field with the largest size is expanded). TEK_Record, // For complex types, real and imaginary parts are expanded recursively. TEK_Complex, // All other types are not expandable. TEK_None }; const TypeExpansionKind Kind; TypeExpansion(TypeExpansionKind K) : Kind(K) {} virtual ~TypeExpansion() {} }; struct ConstantArrayExpansion : TypeExpansion { QualType EltTy; uint64_t NumElts; ConstantArrayExpansion(QualType EltTy, uint64_t NumElts) : TypeExpansion(TEK_ConstantArray), EltTy(EltTy), NumElts(NumElts) {} static bool classof(const TypeExpansion *TE) { return TE->Kind == TEK_ConstantArray; } }; struct RecordExpansion : TypeExpansion { SmallVector Bases; SmallVector Fields; RecordExpansion(SmallVector &&Bases, SmallVector &&Fields) : TypeExpansion(TEK_Record), Bases(Bases), Fields(Fields) {} static bool classof(const TypeExpansion *TE) { return TE->Kind == TEK_Record; } }; struct ComplexExpansion : TypeExpansion { QualType EltTy; ComplexExpansion(QualType EltTy) : TypeExpansion(TEK_Complex), EltTy(EltTy) {} static bool classof(const TypeExpansion *TE) { return TE->Kind == TEK_Complex; } }; struct NoExpansion : TypeExpansion { NoExpansion() : TypeExpansion(TEK_None) {} static bool classof(const TypeExpansion *TE) { return TE->Kind == TEK_None; } }; } // namespace static std::unique_ptr getTypeExpansion(QualType Ty, const ASTContext &Context) { if (const ConstantArrayType *AT = Context.getAsConstantArrayType(Ty)) { return llvm::make_unique( AT->getElementType(), AT->getSize().getZExtValue()); } if (const RecordType *RT = Ty->getAs()) { SmallVector Bases; SmallVector Fields; const RecordDecl *RD = RT->getDecl(); assert(!RD->hasFlexibleArrayMember() && "Cannot expand structure with flexible array."); if (RD->isUnion()) { // Unions can be here only in degenerative cases - all the fields are same // after flattening. Thus we have to use the "largest" field. const FieldDecl *LargestFD = nullptr; CharUnits UnionSize = CharUnits::Zero(); for (const auto *FD : RD->fields()) { // Skip zero length bitfields. if (FD->isBitField() && FD->getBitWidthValue(Context) == 0) continue; assert(!FD->isBitField() && "Cannot expand structure with bit-field members."); CharUnits FieldSize = Context.getTypeSizeInChars(FD->getType()); if (UnionSize < FieldSize) { UnionSize = FieldSize; LargestFD = FD; } } if (LargestFD) Fields.push_back(LargestFD); } else { if (const auto *CXXRD = dyn_cast(RD)) { assert(!CXXRD->isDynamicClass() && "cannot expand vtable pointers in dynamic classes"); for (const CXXBaseSpecifier &BS : CXXRD->bases()) Bases.push_back(&BS); } for (const auto *FD : RD->fields()) { // Skip zero length bitfields. if (FD->isBitField() && FD->getBitWidthValue(Context) == 0) continue; assert(!FD->isBitField() && "Cannot expand structure with bit-field members."); Fields.push_back(FD); } } return llvm::make_unique(std::move(Bases), std::move(Fields)); } if (const ComplexType *CT = Ty->getAs()) { return llvm::make_unique(CT->getElementType()); } return llvm::make_unique(); } static int getExpansionSize(QualType Ty, const ASTContext &Context) { auto Exp = getTypeExpansion(Ty, Context); if (auto CAExp = dyn_cast(Exp.get())) { return CAExp->NumElts * getExpansionSize(CAExp->EltTy, Context); } if (auto RExp = dyn_cast(Exp.get())) { int Res = 0; for (auto BS : RExp->Bases) Res += getExpansionSize(BS->getType(), Context); for (auto FD : RExp->Fields) Res += getExpansionSize(FD->getType(), Context); return Res; } if (isa(Exp.get())) return 2; assert(isa(Exp.get())); return 1; } void CodeGenTypes::getExpandedTypes(QualType Ty, SmallVectorImpl::iterator &TI) { auto Exp = getTypeExpansion(Ty, Context); if (auto CAExp = dyn_cast(Exp.get())) { for (int i = 0, n = CAExp->NumElts; i < n; i++) { getExpandedTypes(CAExp->EltTy, TI); } } else if (auto RExp = dyn_cast(Exp.get())) { for (auto BS : RExp->Bases) getExpandedTypes(BS->getType(), TI); for (auto FD : RExp->Fields) getExpandedTypes(FD->getType(), TI); } else if (auto CExp = dyn_cast(Exp.get())) { llvm::Type *EltTy = ConvertType(CExp->EltTy); *TI++ = EltTy; *TI++ = EltTy; } else { assert(isa(Exp.get())); *TI++ = ConvertType(Ty); } } void CodeGenFunction::ExpandTypeFromArgs( QualType Ty, LValue LV, SmallVectorImpl::iterator &AI) { assert(LV.isSimple() && "Unexpected non-simple lvalue during struct expansion."); auto Exp = getTypeExpansion(Ty, getContext()); if (auto CAExp = dyn_cast(Exp.get())) { for (int i = 0, n = CAExp->NumElts; i < n; i++) { llvm::Value *EltAddr = Builder.CreateConstGEP2_32(nullptr, LV.getAddress(), 0, i); LValue LV = MakeAddrLValue(EltAddr, CAExp->EltTy); ExpandTypeFromArgs(CAExp->EltTy, LV, AI); } } else if (auto RExp = dyn_cast(Exp.get())) { llvm::Value *This = LV.getAddress(); for (const CXXBaseSpecifier *BS : RExp->Bases) { // Perform a single step derived-to-base conversion. llvm::Value *Base = GetAddressOfBaseClass(This, Ty->getAsCXXRecordDecl(), &BS, &BS + 1, /*NullCheckValue=*/false, SourceLocation()); LValue SubLV = MakeAddrLValue(Base, BS->getType()); // Recurse onto bases. ExpandTypeFromArgs(BS->getType(), SubLV, AI); } for (auto FD : RExp->Fields) { // FIXME: What are the right qualifiers here? LValue SubLV = EmitLValueForField(LV, FD); ExpandTypeFromArgs(FD->getType(), SubLV, AI); } } else if (auto CExp = dyn_cast(Exp.get())) { llvm::Value *RealAddr = Builder.CreateStructGEP(nullptr, LV.getAddress(), 0, "real"); EmitStoreThroughLValue(RValue::get(*AI++), MakeAddrLValue(RealAddr, CExp->EltTy)); llvm::Value *ImagAddr = Builder.CreateStructGEP(nullptr, LV.getAddress(), 1, "imag"); EmitStoreThroughLValue(RValue::get(*AI++), MakeAddrLValue(ImagAddr, CExp->EltTy)); } else { assert(isa(Exp.get())); EmitStoreThroughLValue(RValue::get(*AI++), LV); } } void CodeGenFunction::ExpandTypeToArgs( QualType Ty, RValue RV, llvm::FunctionType *IRFuncTy, SmallVectorImpl &IRCallArgs, unsigned &IRCallArgPos) { auto Exp = getTypeExpansion(Ty, getContext()); if (auto CAExp = dyn_cast(Exp.get())) { llvm::Value *Addr = RV.getAggregateAddr(); for (int i = 0, n = CAExp->NumElts; i < n; i++) { llvm::Value *EltAddr = Builder.CreateConstGEP2_32(nullptr, Addr, 0, i); RValue EltRV = convertTempToRValue(EltAddr, CAExp->EltTy, SourceLocation()); ExpandTypeToArgs(CAExp->EltTy, EltRV, IRFuncTy, IRCallArgs, IRCallArgPos); } } else if (auto RExp = dyn_cast(Exp.get())) { llvm::Value *This = RV.getAggregateAddr(); for (const CXXBaseSpecifier *BS : RExp->Bases) { // Perform a single step derived-to-base conversion. llvm::Value *Base = GetAddressOfBaseClass(This, Ty->getAsCXXRecordDecl(), &BS, &BS + 1, /*NullCheckValue=*/false, SourceLocation()); RValue BaseRV = RValue::getAggregate(Base); // Recurse onto bases. ExpandTypeToArgs(BS->getType(), BaseRV, IRFuncTy, IRCallArgs, IRCallArgPos); } LValue LV = MakeAddrLValue(This, Ty); for (auto FD : RExp->Fields) { RValue FldRV = EmitRValueForField(LV, FD, SourceLocation()); ExpandTypeToArgs(FD->getType(), FldRV, IRFuncTy, IRCallArgs, IRCallArgPos); } } else if (isa(Exp.get())) { ComplexPairTy CV = RV.getComplexVal(); IRCallArgs[IRCallArgPos++] = CV.first; IRCallArgs[IRCallArgPos++] = CV.second; } else { assert(isa(Exp.get())); assert(RV.isScalar() && "Unexpected non-scalar rvalue during struct expansion."); // Insert a bitcast as needed. llvm::Value *V = RV.getScalarVal(); if (IRCallArgPos < IRFuncTy->getNumParams() && V->getType() != IRFuncTy->getParamType(IRCallArgPos)) V = Builder.CreateBitCast(V, IRFuncTy->getParamType(IRCallArgPos)); IRCallArgs[IRCallArgPos++] = V; } } /// 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, llvm::StructType *SrcSTy, uint64_t DstSize, CodeGenFunction &CGF) { // We can't dive into a zero-element struct. if (SrcSTy->getNumElements() == 0) return SrcPtr; 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. The // comparison must be made on the store size and not the alloca size. Using // the alloca size may overstate the size of the load. uint64_t FirstEltSize = CGF.CGM.getDataLayout().getTypeStoreSize(FirstElt); if (FirstEltSize < DstSize && FirstEltSize < CGF.CGM.getDataLayout().getTypeStoreSize(SrcSTy)) return SrcPtr; // GEP into the first element. SrcPtr = CGF.Builder.CreateConstGEP2_32(SrcSTy, SrcPtr, 0, 0, "coerce.dive"); // If the first element is a struct, recurse. llvm::Type *SrcTy = cast(SrcPtr->getType())->getElementType(); if (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. /// /// This behaves as if the value were coerced through memory, so on big-endian /// targets the high bits are preserved in a truncation, while little-endian /// targets preserve the low bits. static llvm::Value *CoerceIntOrPtrToIntOrPtr(llvm::Value *Val, 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"); } llvm::Type *DestIntTy = Ty; if (isa(DestIntTy)) DestIntTy = CGF.IntPtrTy; if (Val->getType() != DestIntTy) { const llvm::DataLayout &DL = CGF.CGM.getDataLayout(); if (DL.isBigEndian()) { // Preserve the high bits on big-endian targets. // That is what memory coercion does. uint64_t SrcSize = DL.getTypeSizeInBits(Val->getType()); uint64_t DstSize = DL.getTypeSizeInBits(DestIntTy); if (SrcSize > DstSize) { Val = CGF.Builder.CreateLShr(Val, SrcSize - DstSize, "coerce.highbits"); Val = CGF.Builder.CreateTrunc(Val, DestIntTy, "coerce.val.ii"); } else { Val = CGF.Builder.CreateZExt(Val, DestIntTy, "coerce.val.ii"); Val = CGF.Builder.CreateShl(Val, DstSize - SrcSize, "coerce.highbits"); } } else { // Little-endian targets preserve the low bits. No shifts required. 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, known to be aligned to /// \arg SrcAlign bytes. /// /// 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, llvm::Type *Ty, CharUnits SrcAlign, CodeGenFunction &CGF) { llvm::Type *SrcTy = cast(SrcPtr->getType())->getElementType(); // If SrcTy and Ty are the same, just do a load. if (SrcTy == Ty) return CGF.Builder.CreateAlignedLoad(SrcPtr, SrcAlign.getQuantity()); uint64_t DstSize = CGF.CGM.getDataLayout().getTypeAllocSize(Ty); if (llvm::StructType *SrcSTy = dyn_cast(SrcTy)) { SrcPtr = EnterStructPointerForCoercedAccess(SrcPtr, SrcSTy, DstSize, CGF); SrcTy = cast(SrcPtr->getType())->getElementType(); } uint64_t SrcSize = CGF.CGM.getDataLayout().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.CreateAlignedLoad(SrcPtr, SrcAlign.getQuantity()); 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)); return CGF.Builder.CreateAlignedLoad(Casted, SrcAlign.getQuantity()); } // Otherwise do coercion through memory. This is stupid, but // simple. llvm::AllocaInst *Tmp = CGF.CreateTempAlloca(Ty); Tmp->setAlignment(SrcAlign.getQuantity()); llvm::Type *I8PtrTy = CGF.Builder.getInt8PtrTy(); llvm::Value *Casted = CGF.Builder.CreateBitCast(Tmp, I8PtrTy); llvm::Value *SrcCasted = CGF.Builder.CreateBitCast(SrcPtr, I8PtrTy); CGF.Builder.CreateMemCpy(Casted, SrcCasted, llvm::ConstantInt::get(CGF.IntPtrTy, SrcSize), SrcAlign.getQuantity(), false); return CGF.Builder.CreateAlignedLoad(Tmp, SrcAlign.getQuantity()); } // 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, CharUnits DestAlign) { // Prefer scalar stores to first-class aggregate stores. if (llvm::StructType *STy = dyn_cast(Val->getType())) { const llvm::StructLayout *Layout = CGF.CGM.getDataLayout().getStructLayout(STy); for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { llvm::Value *EltPtr = CGF.Builder.CreateConstGEP2_32(STy, DestPtr, 0, i); llvm::Value *Elt = CGF.Builder.CreateExtractValue(Val, i); uint64_t EltOffset = Layout->getElementOffset(i); CharUnits EltAlign = DestAlign.alignmentAtOffset(CharUnits::fromQuantity(EltOffset)); CGF.Builder.CreateAlignedStore(Elt, EltPtr, EltAlign.getQuantity(), DestIsVolatile); } } else { CGF.Builder.CreateAlignedStore(Val, DestPtr, DestAlign.getQuantity(), DestIsVolatile); } } /// CreateCoercedStore - Create a store to \arg DstPtr from \arg Src, /// where the source and destination may have different types. The /// destination is known to be aligned to \arg DstAlign bytes. /// /// 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, CharUnits DstAlign, CodeGenFunction &CGF) { llvm::Type *SrcTy = Src->getType(); llvm::Type *DstTy = cast(DstPtr->getType())->getElementType(); if (SrcTy == DstTy) { CGF.Builder.CreateAlignedStore(Src, DstPtr, DstAlign.getQuantity(), DstIsVolatile); return; } uint64_t SrcSize = CGF.CGM.getDataLayout().getTypeAllocSize(SrcTy); if (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.CreateAlignedStore(Src, DstPtr, DstAlign.getQuantity(), DstIsVolatile); return; } uint64_t DstSize = CGF.CGM.getDataLayout().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)); BuildAggStore(CGF, Src, Casted, DstIsVolatile, DstAlign); } 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::AllocaInst *Tmp = CGF.CreateTempAlloca(SrcTy); Tmp->setAlignment(DstAlign.getQuantity()); CGF.Builder.CreateAlignedStore(Src, Tmp, DstAlign.getQuantity()); llvm::Type *I8PtrTy = CGF.Builder.getInt8PtrTy(); llvm::Value *Casted = CGF.Builder.CreateBitCast(Tmp, I8PtrTy); llvm::Value *DstCasted = CGF.Builder.CreateBitCast(DstPtr, I8PtrTy); CGF.Builder.CreateMemCpy(DstCasted, Casted, llvm::ConstantInt::get(CGF.IntPtrTy, DstSize), DstAlign.getQuantity(), false); } } namespace { /// Encapsulates information about the way function arguments from /// CGFunctionInfo should be passed to actual LLVM IR function. class ClangToLLVMArgMapping { static const unsigned InvalidIndex = ~0U; unsigned InallocaArgNo; unsigned SRetArgNo; unsigned TotalIRArgs; /// Arguments of LLVM IR function corresponding to single Clang argument. struct IRArgs { unsigned PaddingArgIndex; // Argument is expanded to IR arguments at positions // [FirstArgIndex, FirstArgIndex + NumberOfArgs). unsigned FirstArgIndex; unsigned NumberOfArgs; IRArgs() : PaddingArgIndex(InvalidIndex), FirstArgIndex(InvalidIndex), NumberOfArgs(0) {} }; SmallVector ArgInfo; public: ClangToLLVMArgMapping(const ASTContext &Context, const CGFunctionInfo &FI, bool OnlyRequiredArgs = false) : InallocaArgNo(InvalidIndex), SRetArgNo(InvalidIndex), TotalIRArgs(0), ArgInfo(OnlyRequiredArgs ? FI.getNumRequiredArgs() : FI.arg_size()) { construct(Context, FI, OnlyRequiredArgs); } bool hasInallocaArg() const { return InallocaArgNo != InvalidIndex; } unsigned getInallocaArgNo() const { assert(hasInallocaArg()); return InallocaArgNo; } bool hasSRetArg() const { return SRetArgNo != InvalidIndex; } unsigned getSRetArgNo() const { assert(hasSRetArg()); return SRetArgNo; } unsigned totalIRArgs() const { return TotalIRArgs; } bool hasPaddingArg(unsigned ArgNo) const { assert(ArgNo < ArgInfo.size()); return ArgInfo[ArgNo].PaddingArgIndex != InvalidIndex; } unsigned getPaddingArgNo(unsigned ArgNo) const { assert(hasPaddingArg(ArgNo)); return ArgInfo[ArgNo].PaddingArgIndex; } /// Returns index of first IR argument corresponding to ArgNo, and their /// quantity. std::pair getIRArgs(unsigned ArgNo) const { assert(ArgNo < ArgInfo.size()); return std::make_pair(ArgInfo[ArgNo].FirstArgIndex, ArgInfo[ArgNo].NumberOfArgs); } private: void construct(const ASTContext &Context, const CGFunctionInfo &FI, bool OnlyRequiredArgs); }; void ClangToLLVMArgMapping::construct(const ASTContext &Context, const CGFunctionInfo &FI, bool OnlyRequiredArgs) { unsigned IRArgNo = 0; bool SwapThisWithSRet = false; const ABIArgInfo &RetAI = FI.getReturnInfo(); if (RetAI.getKind() == ABIArgInfo::Indirect) { SwapThisWithSRet = RetAI.isSRetAfterThis(); SRetArgNo = SwapThisWithSRet ? 1 : IRArgNo++; } unsigned ArgNo = 0; unsigned NumArgs = OnlyRequiredArgs ? FI.getNumRequiredArgs() : FI.arg_size(); for (CGFunctionInfo::const_arg_iterator I = FI.arg_begin(); ArgNo < NumArgs; ++I, ++ArgNo) { assert(I != FI.arg_end()); QualType ArgType = I->type; const ABIArgInfo &AI = I->info; // Collect data about IR arguments corresponding to Clang argument ArgNo. auto &IRArgs = ArgInfo[ArgNo]; if (AI.getPaddingType()) IRArgs.PaddingArgIndex = IRArgNo++; switch (AI.getKind()) { case ABIArgInfo::Extend: case ABIArgInfo::Direct: { // FIXME: handle sseregparm someday... llvm::StructType *STy = dyn_cast(AI.getCoerceToType()); if (AI.isDirect() && AI.getCanBeFlattened() && STy) { IRArgs.NumberOfArgs = STy->getNumElements(); } else { IRArgs.NumberOfArgs = 1; } break; } case ABIArgInfo::Indirect: IRArgs.NumberOfArgs = 1; break; case ABIArgInfo::Ignore: case ABIArgInfo::InAlloca: // ignore and inalloca doesn't have matching LLVM parameters. IRArgs.NumberOfArgs = 0; break; case ABIArgInfo::Expand: { IRArgs.NumberOfArgs = getExpansionSize(ArgType, Context); break; } } if (IRArgs.NumberOfArgs > 0) { IRArgs.FirstArgIndex = IRArgNo; IRArgNo += IRArgs.NumberOfArgs; } // Skip over the sret parameter when it comes second. We already handled it // above. if (IRArgNo == 1 && SwapThisWithSRet) IRArgNo++; } assert(ArgNo == ArgInfo.size()); if (FI.usesInAlloca()) InallocaArgNo = IRArgNo++; TotalIRArgs = IRArgNo; } } // namespace /***/ bool CodeGenModule::ReturnTypeUsesSRet(const CGFunctionInfo &FI) { return FI.getReturnInfo().isIndirect(); } bool CodeGenModule::ReturnSlotInterferesWithArgs(const CGFunctionInfo &FI) { return ReturnTypeUsesSRet(FI) && getTargetCodeGenInfo().doesReturnSlotInterfereWithArgs(); } bool CodeGenModule::ReturnTypeUsesFPRet(QualType ResultType) { if (const BuiltinType *BT = ResultType->getAs()) { switch (BT->getKind()) { default: return false; case BuiltinType::Float: return getTarget().useObjCFPRetForRealType(TargetInfo::Float); case BuiltinType::Double: return getTarget().useObjCFPRetForRealType(TargetInfo::Double); case BuiltinType::LongDouble: return getTarget().useObjCFPRetForRealType(TargetInfo::LongDouble); } } return false; } bool CodeGenModule::ReturnTypeUsesFP2Ret(QualType ResultType) { if (const ComplexType *CT = ResultType->getAs()) { if (const BuiltinType *BT = CT->getElementType()->getAs()) { if (BT->getKind() == BuiltinType::LongDouble) return getTarget().useObjCFP2RetForComplexLongDouble(); } } return false; } llvm::FunctionType *CodeGenTypes::GetFunctionType(GlobalDecl GD) { const CGFunctionInfo &FI = arrangeGlobalDeclaration(GD); return GetFunctionType(FI); } llvm::FunctionType * CodeGenTypes::GetFunctionType(const CGFunctionInfo &FI) { bool Inserted = FunctionsBeingProcessed.insert(&FI).second; (void)Inserted; assert(Inserted && "Recursively being processed?"); llvm::Type *resultType = nullptr; 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::InAlloca: if (retAI.getInAllocaSRet()) { // sret things on win32 aren't void, they return the sret pointer. QualType ret = FI.getReturnType(); llvm::Type *ty = ConvertType(ret); unsigned addressSpace = Context.getTargetAddressSpace(ret); resultType = llvm::PointerType::get(ty, addressSpace); } else { resultType = llvm::Type::getVoidTy(getLLVMContext()); } break; case ABIArgInfo::Indirect: { assert(!retAI.getIndirectAlign() && "Align unused on indirect return."); resultType = llvm::Type::getVoidTy(getLLVMContext()); break; } case ABIArgInfo::Ignore: resultType = llvm::Type::getVoidTy(getLLVMContext()); break; } ClangToLLVMArgMapping IRFunctionArgs(getContext(), FI, true); SmallVector ArgTypes(IRFunctionArgs.totalIRArgs()); // Add type for sret argument. if (IRFunctionArgs.hasSRetArg()) { QualType Ret = FI.getReturnType(); llvm::Type *Ty = ConvertType(Ret); unsigned AddressSpace = Context.getTargetAddressSpace(Ret); ArgTypes[IRFunctionArgs.getSRetArgNo()] = llvm::PointerType::get(Ty, AddressSpace); } // Add type for inalloca argument. if (IRFunctionArgs.hasInallocaArg()) { auto ArgStruct = FI.getArgStruct(); assert(ArgStruct); ArgTypes[IRFunctionArgs.getInallocaArgNo()] = ArgStruct->getPointerTo(); } // Add in all of the required arguments. unsigned ArgNo = 0; CGFunctionInfo::const_arg_iterator it = FI.arg_begin(), ie = it + FI.getNumRequiredArgs(); for (; it != ie; ++it, ++ArgNo) { const ABIArgInfo &ArgInfo = it->info; // Insert a padding type to ensure proper alignment. if (IRFunctionArgs.hasPaddingArg(ArgNo)) ArgTypes[IRFunctionArgs.getPaddingArgNo(ArgNo)] = ArgInfo.getPaddingType(); unsigned FirstIRArg, NumIRArgs; std::tie(FirstIRArg, NumIRArgs) = IRFunctionArgs.getIRArgs(ArgNo); switch (ArgInfo.getKind()) { case ABIArgInfo::Ignore: case ABIArgInfo::InAlloca: assert(NumIRArgs == 0); break; case ABIArgInfo::Indirect: { assert(NumIRArgs == 1); // indirect arguments are always on the stack, which is addr space #0. llvm::Type *LTy = ConvertTypeForMem(it->type); ArgTypes[FirstIRArg] = LTy->getPointerTo(); break; } case ABIArgInfo::Extend: case ABIArgInfo::Direct: { // Fast-isel and the optimizer generally like scalar values better than // FCAs, so we flatten them if this is safe to do for this argument. llvm::Type *argType = ArgInfo.getCoerceToType(); llvm::StructType *st = dyn_cast(argType); if (st && ArgInfo.isDirect() && ArgInfo.getCanBeFlattened()) { assert(NumIRArgs == st->getNumElements()); for (unsigned i = 0, e = st->getNumElements(); i != e; ++i) ArgTypes[FirstIRArg + i] = st->getElementType(i); } else { assert(NumIRArgs == 1); ArgTypes[FirstIRArg] = argType; } break; } case ABIArgInfo::Expand: auto ArgTypesIter = ArgTypes.begin() + FirstIRArg; getExpandedTypes(it->type, ArgTypesIter); assert(ArgTypesIter == ArgTypes.begin() + FirstIRArg + NumIRArgs); break; } } bool Erased = FunctionsBeingProcessed.erase(&FI); (void)Erased; assert(Erased && "Not in set?"); return llvm::FunctionType::get(resultType, ArgTypes, FI.isVariadic()); } 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 = &arrangeCXXStructorDeclaration(MD, getFromDtorType(GD.getDtorType())); else Info = &arrangeCXXMethodDeclaration(MD); return GetFunctionType(*Info); } void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI, const Decl *TargetDecl, AttributeListType &PAL, unsigned &CallingConv, bool AttrOnCallSite) { llvm::AttrBuilder FuncAttrs; llvm::AttrBuilder RetAttrs; bool HasOptnone = false; CallingConv = FI.getEffectiveCallingConvention(); if (FI.isNoReturn()) FuncAttrs.addAttribute(llvm::Attribute::NoReturn); // FIXME: handle sseregparm someday... if (TargetDecl) { if (TargetDecl->hasAttr()) FuncAttrs.addAttribute(llvm::Attribute::ReturnsTwice); if (TargetDecl->hasAttr()) FuncAttrs.addAttribute(llvm::Attribute::NoUnwind); if (TargetDecl->hasAttr()) FuncAttrs.addAttribute(llvm::Attribute::NoReturn); if (TargetDecl->hasAttr()) FuncAttrs.addAttribute(llvm::Attribute::NoDuplicate); if (const FunctionDecl *Fn = dyn_cast(TargetDecl)) { const FunctionProtoType *FPT = Fn->getType()->getAs(); if (FPT && FPT->isNothrow(getContext())) FuncAttrs.addAttribute(llvm::Attribute::NoUnwind); // Don't use [[noreturn]] or _Noreturn for a call to a virtual function. // These attributes are not inherited by overloads. const CXXMethodDecl *MD = dyn_cast(Fn); if (Fn->isNoReturn() && !(AttrOnCallSite && MD && MD->isVirtual())) FuncAttrs.addAttribute(llvm::Attribute::NoReturn); } // 'const' and 'pure' attribute functions are also nounwind. if (TargetDecl->hasAttr()) { FuncAttrs.addAttribute(llvm::Attribute::ReadNone); FuncAttrs.addAttribute(llvm::Attribute::NoUnwind); } else if (TargetDecl->hasAttr()) { FuncAttrs.addAttribute(llvm::Attribute::ReadOnly); FuncAttrs.addAttribute(llvm::Attribute::NoUnwind); } if (TargetDecl->hasAttr()) RetAttrs.addAttribute(llvm::Attribute::NoAlias); if (TargetDecl->hasAttr()) RetAttrs.addAttribute(llvm::Attribute::NonNull); HasOptnone = TargetDecl->hasAttr(); } // OptimizeNoneAttr takes precedence over -Os or -Oz. No warning needed. if (!HasOptnone) { if (CodeGenOpts.OptimizeSize) FuncAttrs.addAttribute(llvm::Attribute::OptimizeForSize); if (CodeGenOpts.OptimizeSize == 2) FuncAttrs.addAttribute(llvm::Attribute::MinSize); } if (CodeGenOpts.DisableRedZone) FuncAttrs.addAttribute(llvm::Attribute::NoRedZone); if (CodeGenOpts.NoImplicitFloat) FuncAttrs.addAttribute(llvm::Attribute::NoImplicitFloat); if (CodeGenOpts.EnableSegmentedStacks && !(TargetDecl && TargetDecl->hasAttr())) FuncAttrs.addAttribute("split-stack"); if (AttrOnCallSite) { // Attributes that should go on the call site only. if (!CodeGenOpts.SimplifyLibCalls) FuncAttrs.addAttribute(llvm::Attribute::NoBuiltin); if (!CodeGenOpts.TrapFuncName.empty()) FuncAttrs.addAttribute("trap-func-name", CodeGenOpts.TrapFuncName); } else { // Attributes that should go on the function, but not the call site. if (!CodeGenOpts.DisableFPElim) { FuncAttrs.addAttribute("no-frame-pointer-elim", "false"); } else if (CodeGenOpts.OmitLeafFramePointer) { FuncAttrs.addAttribute("no-frame-pointer-elim", "false"); FuncAttrs.addAttribute("no-frame-pointer-elim-non-leaf"); } else { FuncAttrs.addAttribute("no-frame-pointer-elim", "true"); FuncAttrs.addAttribute("no-frame-pointer-elim-non-leaf"); } FuncAttrs.addAttribute("disable-tail-calls", llvm::toStringRef(CodeGenOpts.DisableTailCalls)); FuncAttrs.addAttribute("less-precise-fpmad", llvm::toStringRef(CodeGenOpts.LessPreciseFPMAD)); FuncAttrs.addAttribute("no-infs-fp-math", llvm::toStringRef(CodeGenOpts.NoInfsFPMath)); FuncAttrs.addAttribute("no-nans-fp-math", llvm::toStringRef(CodeGenOpts.NoNaNsFPMath)); FuncAttrs.addAttribute("unsafe-fp-math", llvm::toStringRef(CodeGenOpts.UnsafeFPMath)); FuncAttrs.addAttribute("use-soft-float", llvm::toStringRef(CodeGenOpts.SoftFloat)); FuncAttrs.addAttribute("stack-protector-buffer-size", llvm::utostr(CodeGenOpts.SSPBufferSize)); if (!CodeGenOpts.StackRealignment) FuncAttrs.addAttribute("no-realign-stack"); // Add target-cpu and target-features attributes to functions. If // we have a decl for the function and it has a target attribute then // parse that and add it to the feature set. StringRef TargetCPU = getTarget().getTargetOpts().CPU; // TODO: Features gets us the features on the command line including // feature dependencies. For canonicalization purposes we might want to // avoid putting features in the target-features set if we know it'll be // one of the default features in the backend, e.g. corei7-avx and +avx or // figure out non-explicit dependencies. // Canonicalize the existing features in a new feature map. // TODO: Migrate the existing backends to keep the map around rather than // the vector. llvm::StringMap FeatureMap; for (auto F : getTarget().getTargetOpts().Features) { const char *Name = F.c_str(); bool Enabled = Name[0] == '+'; getTarget().setFeatureEnabled(FeatureMap, Name + 1, Enabled); } const FunctionDecl *FD = dyn_cast_or_null(TargetDecl); if (FD) { if (const auto *TD = FD->getAttr()) { StringRef FeaturesStr = TD->getFeatures(); SmallVector AttrFeatures; FeaturesStr.split(AttrFeatures, ","); // Grab the various features and prepend a "+" to turn on the feature to // the backend and add them to our existing set of features. for (auto &Feature : AttrFeatures) { // Go ahead and trim whitespace rather than either erroring or // accepting it weirdly. Feature = Feature.trim(); // While we're here iterating check for a different target cpu. if (Feature.startswith("arch=")) TargetCPU = Feature.split("=").second.trim(); else if (Feature.startswith("tune=")) // We don't support cpu tuning this way currently. ; else if (Feature.startswith("fpmath=")) // TODO: Support the fpmath option this way. It will require checking // overall feature validity for the function with the rest of the // attributes on the function. ; else if (Feature.startswith("mno-")) getTarget().setFeatureEnabled(FeatureMap, Feature.split("-").second, false); else getTarget().setFeatureEnabled(FeatureMap, Feature, true); } } } // Produce the canonical string for this set of features. std::vector Features; for (llvm::StringMap::const_iterator it = FeatureMap.begin(), ie = FeatureMap.end(); it != ie; ++it) Features.push_back((it->second ? "+" : "-") + it->first().str()); // Now add the target-cpu and target-features to the function. if (TargetCPU != "") FuncAttrs.addAttribute("target-cpu", TargetCPU); if (!Features.empty()) { std::sort(Features.begin(), Features.end()); FuncAttrs.addAttribute("target-features", llvm::join(Features.begin(), Features.end(), ",")); } } ClangToLLVMArgMapping IRFunctionArgs(getContext(), FI); QualType RetTy = FI.getReturnType(); const ABIArgInfo &RetAI = FI.getReturnInfo(); switch (RetAI.getKind()) { case ABIArgInfo::Extend: if (RetTy->hasSignedIntegerRepresentation()) RetAttrs.addAttribute(llvm::Attribute::SExt); else if (RetTy->hasUnsignedIntegerRepresentation()) RetAttrs.addAttribute(llvm::Attribute::ZExt); // FALL THROUGH case ABIArgInfo::Direct: if (RetAI.getInReg()) RetAttrs.addAttribute(llvm::Attribute::InReg); break; case ABIArgInfo::Ignore: break; case ABIArgInfo::InAlloca: case ABIArgInfo::Indirect: { // inalloca and sret disable readnone and readonly FuncAttrs.removeAttribute(llvm::Attribute::ReadOnly) .removeAttribute(llvm::Attribute::ReadNone); break; } case ABIArgInfo::Expand: llvm_unreachable("Invalid ABI kind for return argument"); } if (const auto *RefTy = RetTy->getAs()) { QualType PTy = RefTy->getPointeeType(); if (!PTy->isIncompleteType() && PTy->isConstantSizeType()) RetAttrs.addDereferenceableAttr(getContext().getTypeSizeInChars(PTy) .getQuantity()); else if (getContext().getTargetAddressSpace(PTy) == 0) RetAttrs.addAttribute(llvm::Attribute::NonNull); } // Attach return attributes. if (RetAttrs.hasAttributes()) { PAL.push_back(llvm::AttributeSet::get( getLLVMContext(), llvm::AttributeSet::ReturnIndex, RetAttrs)); } // Attach attributes to sret. if (IRFunctionArgs.hasSRetArg()) { llvm::AttrBuilder SRETAttrs; SRETAttrs.addAttribute(llvm::Attribute::StructRet); if (RetAI.getInReg()) SRETAttrs.addAttribute(llvm::Attribute::InReg); PAL.push_back(llvm::AttributeSet::get( getLLVMContext(), IRFunctionArgs.getSRetArgNo() + 1, SRETAttrs)); } // Attach attributes to inalloca argument. if (IRFunctionArgs.hasInallocaArg()) { llvm::AttrBuilder Attrs; Attrs.addAttribute(llvm::Attribute::InAlloca); PAL.push_back(llvm::AttributeSet::get( getLLVMContext(), IRFunctionArgs.getInallocaArgNo() + 1, Attrs)); } unsigned ArgNo = 0; for (CGFunctionInfo::const_arg_iterator I = FI.arg_begin(), E = FI.arg_end(); I != E; ++I, ++ArgNo) { QualType ParamType = I->type; const ABIArgInfo &AI = I->info; llvm::AttrBuilder Attrs; // Add attribute for padding argument, if necessary. if (IRFunctionArgs.hasPaddingArg(ArgNo)) { if (AI.getPaddingInReg()) PAL.push_back(llvm::AttributeSet::get( getLLVMContext(), IRFunctionArgs.getPaddingArgNo(ArgNo) + 1, llvm::Attribute::InReg)); } // '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()) Attrs.addAttribute(llvm::Attribute::SExt); else if (ParamType->isUnsignedIntegerOrEnumerationType()) { if (getTypes().getABIInfo().shouldSignExtUnsignedType(ParamType)) Attrs.addAttribute(llvm::Attribute::SExt); else Attrs.addAttribute(llvm::Attribute::ZExt); } // FALL THROUGH case ABIArgInfo::Direct: if (ArgNo == 0 && FI.isChainCall()) Attrs.addAttribute(llvm::Attribute::Nest); else if (AI.getInReg()) Attrs.addAttribute(llvm::Attribute::InReg); break; case ABIArgInfo::Indirect: if (AI.getInReg()) Attrs.addAttribute(llvm::Attribute::InReg); if (AI.getIndirectByVal()) Attrs.addAttribute(llvm::Attribute::ByVal); Attrs.addAlignmentAttr(AI.getIndirectAlign()); // byval disables readnone and readonly. FuncAttrs.removeAttribute(llvm::Attribute::ReadOnly) .removeAttribute(llvm::Attribute::ReadNone); break; case ABIArgInfo::Ignore: case ABIArgInfo::Expand: continue; case ABIArgInfo::InAlloca: // inalloca disables readnone and readonly. FuncAttrs.removeAttribute(llvm::Attribute::ReadOnly) .removeAttribute(llvm::Attribute::ReadNone); continue; } if (const auto *RefTy = ParamType->getAs()) { QualType PTy = RefTy->getPointeeType(); if (!PTy->isIncompleteType() && PTy->isConstantSizeType()) Attrs.addDereferenceableAttr(getContext().getTypeSizeInChars(PTy) .getQuantity()); else if (getContext().getTargetAddressSpace(PTy) == 0) Attrs.addAttribute(llvm::Attribute::NonNull); } if (Attrs.hasAttributes()) { unsigned FirstIRArg, NumIRArgs; std::tie(FirstIRArg, NumIRArgs) = IRFunctionArgs.getIRArgs(ArgNo); for (unsigned i = 0; i < NumIRArgs; i++) PAL.push_back(llvm::AttributeSet::get(getLLVMContext(), FirstIRArg + i + 1, Attrs)); } } assert(ArgNo == FI.arg_size()); if (FuncAttrs.hasAttributes()) PAL.push_back(llvm:: AttributeSet::get(getLLVMContext(), llvm::AttributeSet::FunctionIndex, 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) { 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"); } /// Returns the attribute (either parameter attribute, or function /// attribute), which declares argument ArgNo to be non-null. static const NonNullAttr *getNonNullAttr(const Decl *FD, const ParmVarDecl *PVD, QualType ArgType, unsigned ArgNo) { // FIXME: __attribute__((nonnull)) can also be applied to: // - references to pointers, where the pointee is known to be // nonnull (apparently a Clang extension) // - transparent unions containing pointers // In the former case, LLVM IR cannot represent the constraint. In // the latter case, we have no guarantee that the transparent union // is in fact passed as a pointer. if (!ArgType->isAnyPointerType() && !ArgType->isBlockPointerType()) return nullptr; // First, check attribute on parameter itself. if (PVD) { if (auto ParmNNAttr = PVD->getAttr()) return ParmNNAttr; } // Check function attributes. if (!FD) return nullptr; for (const auto *NNAttr : FD->specific_attrs()) { if (NNAttr->isNonNull(ArgNo)) return NNAttr; } return nullptr; } void CodeGenFunction::EmitFunctionProlog(const CGFunctionInfo &FI, llvm::Function *Fn, const FunctionArgList &Args) { if (CurCodeDecl && CurCodeDecl->hasAttr()) // Naked functions don't have prologues. return; // 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(CurCodeDecl)) { if (FD->hasImplicitReturnZero()) { QualType RetTy = FD->getReturnType().getUnqualifiedType(); 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. ClangToLLVMArgMapping IRFunctionArgs(CGM.getContext(), FI); // Flattened function arguments. SmallVector FnArgs; FnArgs.reserve(IRFunctionArgs.totalIRArgs()); for (auto &Arg : Fn->args()) { FnArgs.push_back(&Arg); } assert(FnArgs.size() == IRFunctionArgs.totalIRArgs()); // If we're using inalloca, all the memory arguments are GEPs off of the last // parameter, which is a pointer to the complete memory area. llvm::Value *ArgStruct = nullptr; if (IRFunctionArgs.hasInallocaArg()) { ArgStruct = FnArgs[IRFunctionArgs.getInallocaArgNo()]; assert(ArgStruct->getType() == FI.getArgStruct()->getPointerTo()); } // Name the struct return parameter. if (IRFunctionArgs.hasSRetArg()) { auto AI = FnArgs[IRFunctionArgs.getSRetArgNo()]; AI->setName("agg.result"); AI->addAttr(llvm::AttributeSet::get(getLLVMContext(), AI->getArgNo() + 1, llvm::Attribute::NoAlias)); } // Track if we received the parameter as a pointer (indirect, byval, or // inalloca). If already have a pointer, EmitParmDecl doesn't need to copy it // into a local alloca for us. enum ValOrPointer { HaveValue = 0, HavePointer = 1 }; typedef llvm::PointerIntPair ValueAndIsPtr; SmallVector ArgVals; ArgVals.reserve(Args.size()); // Create a pointer value for every parameter declaration. This usually // entails copying one or more LLVM IR arguments into an alloca. Don't push // any cleanups or do anything that might unwind. We do that separately, so // we can push the cleanups in the correct order for the ABI. assert(FI.arg_size() == Args.size() && "Mismatch between function signature & arguments."); unsigned ArgNo = 0; 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(); unsigned FirstIRArg, NumIRArgs; std::tie(FirstIRArg, NumIRArgs) = IRFunctionArgs.getIRArgs(ArgNo); switch (ArgI.getKind()) { case ABIArgInfo::InAlloca: { assert(NumIRArgs == 0); llvm::Value *V = Builder.CreateStructGEP(FI.getArgStruct(), ArgStruct, ArgI.getInAllocaFieldIndex(), Arg->getName()); ArgVals.push_back(ValueAndIsPtr(V, HavePointer)); break; } case ABIArgInfo::Indirect: { assert(NumIRArgs == 1); llvm::Value *V = FnArgs[FirstIRArg]; if (!hasScalarEvaluationKind(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. 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; } ArgVals.push_back(ValueAndIsPtr(V, HavePointer)); } else { // Load scalar value from indirect argument. V = EmitLoadOfScalar(V, false, ArgI.getIndirectAlign(), Ty, Arg->getLocStart()); if (isPromoted) V = emitArgumentDemotion(*this, Arg, V); ArgVals.push_back(ValueAndIsPtr(V, HaveValue)); } 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(NumIRArgs == 1); auto AI = FnArgs[FirstIRArg]; llvm::Value *V = AI; if (const ParmVarDecl *PVD = dyn_cast(Arg)) { if (getNonNullAttr(CurCodeDecl, PVD, PVD->getType(), PVD->getFunctionScopeIndex())) AI->addAttr(llvm::AttributeSet::get(getLLVMContext(), AI->getArgNo() + 1, llvm::Attribute::NonNull)); QualType OTy = PVD->getOriginalType(); if (const auto *ArrTy = getContext().getAsConstantArrayType(OTy)) { // A C99 array parameter declaration with the static keyword also // indicates dereferenceability, and if the size is constant we can // use the dereferenceable attribute (which requires the size in // bytes). if (ArrTy->getSizeModifier() == ArrayType::Static) { QualType ETy = ArrTy->getElementType(); uint64_t ArrSize = ArrTy->getSize().getZExtValue(); if (!ETy->isIncompleteType() && ETy->isConstantSizeType() && ArrSize) { llvm::AttrBuilder Attrs; Attrs.addDereferenceableAttr( getContext().getTypeSizeInChars(ETy).getQuantity()*ArrSize); AI->addAttr(llvm::AttributeSet::get(getLLVMContext(), AI->getArgNo() + 1, Attrs)); } else if (getContext().getTargetAddressSpace(ETy) == 0) { AI->addAttr(llvm::AttributeSet::get(getLLVMContext(), AI->getArgNo() + 1, llvm::Attribute::NonNull)); } } } else if (const auto *ArrTy = getContext().getAsVariableArrayType(OTy)) { // For C99 VLAs with the static keyword, we don't know the size so // we can't use the dereferenceable attribute, but in addrspace(0) // we know that it must be nonnull. if (ArrTy->getSizeModifier() == VariableArrayType::Static && !getContext().getTargetAddressSpace(ArrTy->getElementType())) AI->addAttr(llvm::AttributeSet::get(getLLVMContext(), AI->getArgNo() + 1, llvm::Attribute::NonNull)); } const auto *AVAttr = PVD->getAttr(); if (!AVAttr) if (const auto *TOTy = dyn_cast(OTy)) AVAttr = TOTy->getDecl()->getAttr(); if (AVAttr) { llvm::Value *AlignmentValue = EmitScalarExpr(AVAttr->getAlignment()); llvm::ConstantInt *AlignmentCI = cast(AlignmentValue); unsigned Alignment = std::min((unsigned) AlignmentCI->getZExtValue(), +llvm::Value::MaximumAlignment); llvm::AttrBuilder Attrs; Attrs.addAlignmentAttr(Alignment); AI->addAttr(llvm::AttributeSet::get(getLLVMContext(), AI->getArgNo() + 1, Attrs)); } } if (Arg->getType().isRestrictQualified()) AI->addAttr(llvm::AttributeSet::get(getLLVMContext(), AI->getArgNo() + 1, llvm::Attribute::NoAlias)); // Ensure the argument is the correct type. if (V->getType() != ArgI.getCoerceToType()) V = Builder.CreateBitCast(V, ArgI.getCoerceToType()); if (isPromoted) V = emitArgumentDemotion(*this, Arg, V); if (const CXXMethodDecl *MD = dyn_cast_or_null(CurCodeDecl)) { if (MD->isVirtual() && Arg == CXXABIThisDecl) V = CGM.getCXXABI(). adjustThisParameterInVirtualFunctionPrologue(*this, CurGD, V); } // Because of merging of function types from multiple decls it is // possible for the type of an argument to not match the corresponding // type in the function type. Since we are codegening the callee // in here, add a cast to the argument type. llvm::Type *LTy = ConvertType(Arg->getType()); if (V->getType() != LTy) V = Builder.CreateBitCast(V, LTy); ArgVals.push_back(ValueAndIsPtr(V, HaveValue)); break; } llvm::AllocaInst *Alloca = CreateMemTemp(Ty, Arg->getName()); // 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.getDataLayout().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. CharUnits PtrAlign = CharUnits::fromQuantity(AlignmentToUse); // 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(Builder.getInt8Ty(), Ptr, Offs); Ptr = Builder.CreateBitCast(Ptr, llvm::PointerType::getUnqual(ArgI.getCoerceToType())); PtrAlign = PtrAlign.alignmentAtOffset(CharUnits::fromQuantity(Offs)); } // Fast-isel and the optimizer generally like scalar values better than // FCAs, so we flatten them if this is safe to do for this argument. llvm::StructType *STy = dyn_cast(ArgI.getCoerceToType()); if (ArgI.isDirect() && ArgI.getCanBeFlattened() && STy && STy->getNumElements() > 1) { uint64_t SrcSize = CGM.getDataLayout().getTypeAllocSize(STy); llvm::Type *DstTy = cast(Ptr->getType())->getElementType(); uint64_t DstSize = CGM.getDataLayout().getTypeAllocSize(DstTy); if (SrcSize <= DstSize) { Ptr = Builder.CreateBitCast(Ptr, llvm::PointerType::getUnqual(STy)); assert(STy->getNumElements() == NumIRArgs); for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { auto AI = FnArgs[FirstIRArg + i]; AI->setName(Arg->getName() + ".coerce" + Twine(i)); llvm::Value *EltPtr = Builder.CreateConstGEP2_32(STy, Ptr, 0, i); Builder.CreateStore(AI, EltPtr); } } else { llvm::AllocaInst *TempAlloca = CreateTempAlloca(ArgI.getCoerceToType(), "coerce"); TempAlloca->setAlignment(AlignmentToUse); llvm::Value *TempV = TempAlloca; assert(STy->getNumElements() == NumIRArgs); for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { auto AI = FnArgs[FirstIRArg + i]; AI->setName(Arg->getName() + ".coerce" + Twine(i)); llvm::Value *EltPtr = Builder.CreateConstGEP2_32(ArgI.getCoerceToType(), TempV, 0, i); Builder.CreateStore(AI, EltPtr); } Builder.CreateMemCpy(Ptr, TempV, DstSize, AlignmentToUse); } } else { // Simple case, just do a coerced store of the argument into the alloca. assert(NumIRArgs == 1); auto AI = FnArgs[FirstIRArg]; AI->setName(Arg->getName() + ".coerce"); CreateCoercedStore(AI, Ptr, /*DestIsVolatile=*/false, PtrAlign, *this); } // Match to what EmitParmDecl is expecting for this type. if (CodeGenFunction::hasScalarEvaluationKind(Ty)) { V = EmitLoadOfScalar(V, false, AlignmentToUse, Ty, Arg->getLocStart()); if (isPromoted) V = emitArgumentDemotion(*this, Arg, V); ArgVals.push_back(ValueAndIsPtr(V, HaveValue)); } else { ArgVals.push_back(ValueAndIsPtr(V, HavePointer)); } break; } 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::AllocaInst *Alloca = CreateMemTemp(Ty); CharUnits Align = getContext().getDeclAlign(Arg); Alloca->setAlignment(Align.getQuantity()); LValue LV = MakeAddrLValue(Alloca, Ty, Align); ArgVals.push_back(ValueAndIsPtr(Alloca, HavePointer)); auto FnArgIter = FnArgs.begin() + FirstIRArg; ExpandTypeFromArgs(Ty, LV, FnArgIter); assert(FnArgIter == FnArgs.begin() + FirstIRArg + NumIRArgs); for (unsigned i = 0, e = NumIRArgs; i != e; ++i) { auto AI = FnArgs[FirstIRArg + i]; AI->setName(Arg->getName() + "." + Twine(i)); } break; } case ABIArgInfo::Ignore: assert(NumIRArgs == 0); // Initialize the local variable appropriately. if (!hasScalarEvaluationKind(Ty)) { ArgVals.push_back(ValueAndIsPtr(CreateMemTemp(Ty), HavePointer)); } else { llvm::Value *U = llvm::UndefValue::get(ConvertType(Arg->getType())); ArgVals.push_back(ValueAndIsPtr(U, HaveValue)); } break; } } if (getTarget().getCXXABI().areArgsDestroyedLeftToRightInCallee()) { for (int I = Args.size() - 1; I >= 0; --I) EmitParmDecl(*Args[I], ArgVals[I].getPointer(), ArgVals[I].getInt(), I + 1); } else { for (unsigned I = 0, E = Args.size(); I != E; ++I) EmitParmDecl(*Args[I], ArgVals[I].getPointer(), ArgVals[I].getInt(), I + 1); } } static void eraseUnusedBitCasts(llvm::Instruction *insn) { while (insn->use_empty()) { llvm::BitCastInst *bitcast = dyn_cast(insn); if (!bitcast) return; // This is "safe" because we would have used a ConstantExpr otherwise. insn = cast(bitcast->getOperand(0)); bitcast->eraseFromParent(); } } /// 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 nullptr; if (&BB->back() != result) return nullptr; llvm::Type *resultType = result->getType(); // result is in a BasicBlock and is therefore an Instruction. llvm::Instruction *generator = cast(result); 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 nullptr; 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 nullptr; bool doRetainAutorelease; if (call->getCalledValue() == CGF.CGM.getARCEntrypoints().objc_retain) { doRetainAutorelease = true; } else if (call->getCalledValue() == CGF.CGM.getARCEntrypoints() .objc_retainAutoreleasedReturnValue) { doRetainAutorelease = false; // If we emitted an assembly marker for this call (and the // ARCEntrypoints field should have been set if so), go looking // for that call. If we can't find it, we can't do this // optimization. But it should always be the immediately previous // instruction, unless we needed bitcasts around the call. if (CGF.CGM.getARCEntrypoints().retainAutoreleasedReturnValueMarker) { llvm::Instruction *prev = call->getPrevNode(); assert(prev); if (isa(prev)) { prev = prev->getPrevNode(); assert(prev); } assert(isa(prev)); assert(cast(prev)->getCalledValue() == CGF.CGM.getARCEntrypoints().retainAutoreleasedReturnValueMarker); insnsToKill.push_back(prev); } } else { return nullptr; } 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 (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); } /// If this is a +1 of the value of an immutable 'self', remove it. static llvm::Value *tryRemoveRetainOfSelf(CodeGenFunction &CGF, llvm::Value *result) { // This is only applicable to a method with an immutable 'self'. const ObjCMethodDecl *method = dyn_cast_or_null(CGF.CurCodeDecl); if (!method) return nullptr; const VarDecl *self = method->getSelfDecl(); if (!self->getType().isConstQualified()) return nullptr; // Look for a retain call. llvm::CallInst *retainCall = dyn_cast(result->stripPointerCasts()); if (!retainCall || retainCall->getCalledValue() != CGF.CGM.getARCEntrypoints().objc_retain) return nullptr; // Look for an ordinary load of 'self'. llvm::Value *retainedValue = retainCall->getArgOperand(0); llvm::LoadInst *load = dyn_cast(retainedValue->stripPointerCasts()); if (!load || load->isAtomic() || load->isVolatile() || load->getPointerOperand() != CGF.GetAddrOfLocalVar(self)) return nullptr; // Okay! Burn it all down. This relies for correctness on the // assumption that the retain is emitted as part of the return and // that thereafter everything is used "linearly". llvm::Type *resultType = result->getType(); eraseUnusedBitCasts(cast(result)); assert(retainCall->use_empty()); retainCall->eraseFromParent(); eraseUnusedBitCasts(cast(retainedValue)); return CGF.Builder.CreateBitCast(load, resultType); } /// Emit an ARC autorelease of the result of a function. /// /// \return the value to actually return from the function static llvm::Value *emitAutoreleaseOfResult(CodeGenFunction &CGF, llvm::Value *result) { // If we're returning 'self', kill the initial retain. This is a // heuristic attempt to "encourage correctness" in the really unfortunate // case where we have a return of self during a dealloc and we desperately // need to avoid the possible autorelease. if (llvm::Value *self = tryRemoveRetainOfSelf(CGF, result)) return self; // 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); } /// Heuristically search for a dominating store to the return-value slot. static llvm::StoreInst *findDominatingStoreToReturnValue(CodeGenFunction &CGF) { // If there are multiple uses of the return-value slot, just check // for something immediately preceding the IP. Sometimes this can // happen with how we generate implicit-returns; it can also happen // with noreturn cleanups. if (!CGF.ReturnValue->hasOneUse()) { llvm::BasicBlock *IP = CGF.Builder.GetInsertBlock(); if (IP->empty()) return nullptr; llvm::Instruction *I = &IP->back(); // Skip lifetime markers for (llvm::BasicBlock::reverse_iterator II = IP->rbegin(), IE = IP->rend(); II != IE; ++II) { if (llvm::IntrinsicInst *Intrinsic = dyn_cast(&*II)) { if (Intrinsic->getIntrinsicID() == llvm::Intrinsic::lifetime_end) { const llvm::Value *CastAddr = Intrinsic->getArgOperand(1); ++II; if (II == IE) break; if (isa(&*II) && (CastAddr == &*II)) continue; } } I = &*II; break; } llvm::StoreInst *store = dyn_cast(I); if (!store) return nullptr; if (store->getPointerOperand() != CGF.ReturnValue) return nullptr; assert(!store->isAtomic() && !store->isVolatile()); // see below return store; } llvm::StoreInst *store = dyn_cast(CGF.ReturnValue->user_back()); if (!store) return nullptr; // These aren't actually possible for non-coerced returns, and we // only care about non-coerced returns on this code path. assert(!store->isAtomic() && !store->isVolatile()); // Now do a first-and-dirty dominance check: just walk up the // single-predecessors chain from the current insertion point. llvm::BasicBlock *StoreBB = store->getParent(); llvm::BasicBlock *IP = CGF.Builder.GetInsertBlock(); while (IP != StoreBB) { if (!(IP = IP->getSinglePredecessor())) return nullptr; } // Okay, the store's basic block dominates the insertion point; we // can do our thing. return store; } void CodeGenFunction::EmitFunctionEpilog(const CGFunctionInfo &FI, bool EmitRetDbgLoc, SourceLocation EndLoc) { if (CurCodeDecl && CurCodeDecl->hasAttr()) { // Naked functions don't have epilogues. Builder.CreateUnreachable(); return; } // Functions with no result always return void. if (!ReturnValue) { Builder.CreateRetVoid(); return; } llvm::DebugLoc RetDbgLoc; llvm::Value *RV = nullptr; QualType RetTy = FI.getReturnType(); const ABIArgInfo &RetAI = FI.getReturnInfo(); switch (RetAI.getKind()) { case ABIArgInfo::InAlloca: // Aggregrates get evaluated directly into the destination. Sometimes we // need to return the sret value in a register, though. assert(hasAggregateEvaluationKind(RetTy)); if (RetAI.getInAllocaSRet()) { llvm::Function::arg_iterator EI = CurFn->arg_end(); --EI; llvm::Value *ArgStruct = EI; llvm::Value *SRet = Builder.CreateStructGEP( nullptr, ArgStruct, RetAI.getInAllocaFieldIndex()); RV = Builder.CreateLoad(SRet, "sret"); } break; case ABIArgInfo::Indirect: { auto AI = CurFn->arg_begin(); if (RetAI.isSRetAfterThis()) ++AI; switch (getEvaluationKind(RetTy)) { case TEK_Complex: { ComplexPairTy RT = EmitLoadOfComplex(MakeNaturalAlignAddrLValue(ReturnValue, RetTy), EndLoc); EmitStoreOfComplex(RT, MakeNaturalAlignAddrLValue(AI, RetTy), /*isInit*/ true); break; } case TEK_Aggregate: // Do nothing; aggregrates get evaluated directly into the destination. break; case TEK_Scalar: EmitStoreOfScalar(Builder.CreateLoad(ReturnValue), MakeNaturalAlignAddrLValue(AI, RetTy), /*isInit*/ true); break; } 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 there is a dominating store to ReturnValue, we can elide // the load, zap the store, and usually zap the alloca. if (llvm::StoreInst *SI = findDominatingStoreToReturnValue(*this)) { // Reuse the debug location from the store unless there is // cleanup code to be emitted between the store and return // instruction. if (EmitRetDbgLoc && !AutoreleaseResult) RetDbgLoc = SI->getDebugLoc(); // Get the stored value and nuke the now-dead store. 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 = nullptr; } // Otherwise, we have to do a simple load. } else { RV = Builder.CreateLoad(ReturnValue); } } else { llvm::Value *V = ReturnValue; CharUnits Align = getContext().getTypeAlignInChars(RetTy); // 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(Builder.getInt8Ty(), V, Offs); V = Builder.CreateBitCast(V, llvm::PointerType::getUnqual(RetAI.getCoerceToType())); Align = Align.alignmentAtOffset(CharUnits::fromQuantity(Offs)); } RV = CreateCoercedLoad(V, RetAI.getCoerceToType(), Align, *this); } // In ARC, end functions that return a retainable type with a call // to objc_autoreleaseReturnValue. if (AutoreleaseResult) { assert(getLangOpts().ObjCAutoRefCount && !FI.isReturnsRetained() && RetTy->isObjCRetainableType()); RV = emitAutoreleaseOfResult(*this, RV); } break; case ABIArgInfo::Ignore: break; case ABIArgInfo::Expand: llvm_unreachable("Invalid ABI kind for return argument"); } llvm::Instruction *Ret; if (RV) { if (SanOpts.has(SanitizerKind::ReturnsNonnullAttribute)) { if (auto RetNNAttr = CurGD.getDecl()->getAttr()) { SanitizerScope SanScope(this); llvm::Value *Cond = Builder.CreateICmpNE( RV, llvm::Constant::getNullValue(RV->getType())); llvm::Constant *StaticData[] = { EmitCheckSourceLocation(EndLoc), EmitCheckSourceLocation(RetNNAttr->getLocation()), }; EmitCheck(std::make_pair(Cond, SanitizerKind::ReturnsNonnullAttribute), "nonnull_return", StaticData, None); } } Ret = Builder.CreateRet(RV); } else { Ret = Builder.CreateRetVoid(); } if (RetDbgLoc) Ret->setDebugLoc(std::move(RetDbgLoc)); } static bool isInAllocaArgument(CGCXXABI &ABI, QualType type) { const CXXRecordDecl *RD = type->getAsCXXRecordDecl(); return RD && ABI.getRecordArgABI(RD) == CGCXXABI::RAA_DirectInMemory; } static AggValueSlot createPlaceholderSlot(CodeGenFunction &CGF, QualType Ty) { // FIXME: Generate IR in one pass, rather than going back and fixing up these // placeholders. llvm::Type *IRTy = CGF.ConvertTypeForMem(Ty); llvm::Value *Placeholder = llvm::UndefValue::get(IRTy->getPointerTo()->getPointerTo()); Placeholder = CGF.Builder.CreateLoad(Placeholder); return AggValueSlot::forAddr(Placeholder, CharUnits::Zero(), Ty.getQualifiers(), AggValueSlot::IsNotDestructed, AggValueSlot::DoesNotNeedGCBarriers, AggValueSlot::IsNotAliased); } void CodeGenFunction::EmitDelegateCallArg(CallArgList &args, const VarDecl *param, SourceLocation loc) { // 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 non-scalars are pointers directly to the aggregate. // I don't know why references to scalars are different here. if (const ReferenceType *ref = type->getAs()) { if (!hasScalarEvaluationKind(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); } assert(!isInAllocaArgument(CGM.getCXXABI(), type) && "cannot emit delegate call arguments for inalloca arguments!"); args.add(convertTempToRValue(local, type, loc), 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) { const LValue &srcLV = writeback.Source; llvm::Value *srcAddr = srcLV.getAddress(); assert(!isProvablyNull(srcAddr) && "shouldn't have writeback for provably null argument"); llvm::BasicBlock *contBB = nullptr; // 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. // If we have a "to use" value, it's something we need to emit a use // of. This has to be carefully threaded in: if it's done after the // release it's potentially undefined behavior (and the optimizer // will ignore it), and if it happens before the retain then the // optimizer could move the release there. if (writeback.ToUse) { assert(srcLV.getObjCLifetime() == Qualifiers::OCL_Strong); // Retain the new value. No need to block-copy here: the block's // being passed up the stack. value = CGF.EmitARCRetainNonBlock(value); // Emit the intrinsic use here. CGF.EmitARCIntrinsicUse(writeback.ToUse); // Load the old value (primitively). llvm::Value *oldValue = CGF.EmitLoadOfScalar(srcLV, SourceLocation()); // Put the new value in place (primitively). CGF.EmitStoreOfScalar(value, srcLV, /*init*/ false); // Release the old value. CGF.EmitARCRelease(oldValue, srcLV.isARCPreciseLifetime()); // Otherwise, we can just do a normal lvalue store. } else { CGF.EmitStoreThroughLValue(RValue::get(value), srcLV); } // Jump to the continuation block. if (!provablyNonNull) CGF.EmitBlock(contBB); } static void emitWritebacks(CodeGenFunction &CGF, const CallArgList &args) { for (const auto &I : args.writebacks()) emitWriteback(CGF, I); } static void deactivateArgCleanupsBeforeCall(CodeGenFunction &CGF, const CallArgList &CallArgs) { assert(CGF.getTarget().getCXXABI().areArgsDestroyedLeftToRightInCallee()); ArrayRef Cleanups = CallArgs.getCleanupsToDeactivate(); // Iterate in reverse to increase the likelihood of popping the cleanup. for (ArrayRef::reverse_iterator I = Cleanups.rbegin(), E = Cleanups.rend(); I != E; ++I) { CGF.DeactivateCleanupBlock(I->Cleanup, I->IsActiveIP); I->IsActiveIP->eraseFromParent(); } } static const Expr *maybeGetUnaryAddrOfOperand(const Expr *E) { if (const UnaryOperator *uop = dyn_cast(E->IgnoreParens())) if (uop->getOpcode() == UO_AddrOf) return uop->getSubExpr(); return nullptr; } /// 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) { LValue srcLV; // Make an optimistic effort to emit the address as an l-value. // This can fail if the argument expression is more complicated. if (const Expr *lvExpr = maybeGetUnaryAddrOfOperand(CRE->getSubExpr())) { srcLV = CGF.EmitLValue(lvExpr); // Otherwise, just emit it as a scalar. } else { llvm::Value *srcAddr = CGF.EmitScalarExpr(CRE->getSubExpr()); QualType srcAddrType = CRE->getSubExpr()->getType()->castAs()->getPointeeType(); srcLV = CGF.MakeNaturalAlignAddrLValue(srcAddr, srcAddrType); } llvm::Value *srcAddr = srcLV.getAddress(); // The dest and src types don't necessarily match in LLVM terms // because of the crazy ObjC compatibility rules. 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; } // Create the temporary. llvm::Value *temp = CGF.CreateTempAlloca(destType->getElementType(), "icr.temp"); // Loading an l-value can introduce a cleanup if the l-value is __weak, // and that cleanup will be conditional if we can't prove that the l-value // isn't null, so we need to register a dominating point so that the cleanups // system will make valid IR. CodeGenFunction::ConditionalEvaluation condEval(CGF); // 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 = nullptr; llvm::BasicBlock *originBB = nullptr; // 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) { originBB = CGF.Builder.GetInsertBlock(); contBB = CGF.createBasicBlock("icr.cont"); llvm::BasicBlock *copyBB = CGF.createBasicBlock("icr.copy"); CGF.Builder.CreateCondBr(isNull, contBB, copyBB); CGF.EmitBlock(copyBB); condEval.begin(CGF); } } llvm::Value *valueToUse = nullptr; // Perform a copy if necessary. if (shouldCopy) { RValue srcRV = CGF.EmitLoadOfLValue(srcLV, SourceLocation()); 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); // If optimization is enabled, and the value was held in a // __strong variable, we need to tell the optimizer that this // value has to stay alive until we're doing the store back. // This is because the temporary is effectively unretained, // and so otherwise we can violate the high-level semantics. if (CGF.CGM.getCodeGenOpts().OptimizationLevel != 0 && srcLV.getObjCLifetime() == Qualifiers::OCL_Strong) { valueToUse = src; } } // Finish the control flow if we needed it. if (shouldCopy && !provablyNonNull) { llvm::BasicBlock *copyBB = CGF.Builder.GetInsertBlock(); CGF.EmitBlock(contBB); // Make a phi for the value to intrinsically use. if (valueToUse) { llvm::PHINode *phiToUse = CGF.Builder.CreatePHI(valueToUse->getType(), 2, "icr.to-use"); phiToUse->addIncoming(valueToUse, copyBB); phiToUse->addIncoming(llvm::UndefValue::get(valueToUse->getType()), originBB); valueToUse = phiToUse; } condEval.end(CGF); } args.addWriteback(srcLV, temp, valueToUse); args.add(RValue::get(finalArgument), CRE->getType()); } void CallArgList::allocateArgumentMemory(CodeGenFunction &CGF) { assert(!StackBase && !StackCleanup.isValid()); // Save the stack. llvm::Function *F = CGF.CGM.getIntrinsic(llvm::Intrinsic::stacksave); StackBase = CGF.Builder.CreateCall(F, {}, "inalloca.save"); // Control gets really tied up in landing pads, so we have to spill the // stacksave to an alloca to avoid violating SSA form. // TODO: This is dead if we never emit the cleanup. We should create the // alloca and store lazily on the first cleanup emission. StackBaseMem = CGF.CreateTempAlloca(CGF.Int8PtrTy, "inalloca.spmem"); CGF.Builder.CreateStore(StackBase, StackBaseMem); CGF.pushStackRestore(EHCleanup, StackBaseMem); StackCleanup = CGF.EHStack.getInnermostEHScope(); assert(StackCleanup.isValid()); } void CallArgList::freeArgumentMemory(CodeGenFunction &CGF) const { if (StackBase) { CGF.DeactivateCleanupBlock(StackCleanup, StackBase); llvm::Value *F = CGF.CGM.getIntrinsic(llvm::Intrinsic::stackrestore); // We could load StackBase from StackBaseMem, but in the non-exceptional // case we can skip it. CGF.Builder.CreateCall(F, StackBase); } } void CodeGenFunction::EmitNonNullArgCheck(RValue RV, QualType ArgType, SourceLocation ArgLoc, const FunctionDecl *FD, unsigned ParmNum) { if (!SanOpts.has(SanitizerKind::NonnullAttribute) || !FD) return; auto PVD = ParmNum < FD->getNumParams() ? FD->getParamDecl(ParmNum) : nullptr; unsigned ArgNo = PVD ? PVD->getFunctionScopeIndex() : ParmNum; auto NNAttr = getNonNullAttr(FD, PVD, ArgType, ArgNo); if (!NNAttr) return; SanitizerScope SanScope(this); assert(RV.isScalar()); llvm::Value *V = RV.getScalarVal(); llvm::Value *Cond = Builder.CreateICmpNE(V, llvm::Constant::getNullValue(V->getType())); llvm::Constant *StaticData[] = { EmitCheckSourceLocation(ArgLoc), EmitCheckSourceLocation(NNAttr->getLocation()), llvm::ConstantInt::get(Int32Ty, ArgNo + 1), }; EmitCheck(std::make_pair(Cond, SanitizerKind::NonnullAttribute), "nonnull_arg", StaticData, None); } void CodeGenFunction::EmitCallArgs(CallArgList &Args, ArrayRef ArgTypes, CallExpr::const_arg_iterator ArgBeg, CallExpr::const_arg_iterator ArgEnd, const FunctionDecl *CalleeDecl, unsigned ParamsToSkip) { // We *have* to evaluate arguments from right to left in the MS C++ ABI, // because arguments are destroyed left to right in the callee. if (CGM.getTarget().getCXXABI().areArgsDestroyedLeftToRightInCallee()) { // Insert a stack save if we're going to need any inalloca args. bool HasInAllocaArgs = false; for (ArrayRef::iterator I = ArgTypes.begin(), E = ArgTypes.end(); I != E && !HasInAllocaArgs; ++I) HasInAllocaArgs = isInAllocaArgument(CGM.getCXXABI(), *I); if (HasInAllocaArgs) { assert(getTarget().getTriple().getArch() == llvm::Triple::x86); Args.allocateArgumentMemory(*this); } // Evaluate each argument. size_t CallArgsStart = Args.size(); for (int I = ArgTypes.size() - 1; I >= 0; --I) { CallExpr::const_arg_iterator Arg = ArgBeg + I; EmitCallArg(Args, *Arg, ArgTypes[I]); EmitNonNullArgCheck(Args.back().RV, ArgTypes[I], Arg->getExprLoc(), CalleeDecl, ParamsToSkip + I); } // Un-reverse the arguments we just evaluated so they match up with the LLVM // IR function. std::reverse(Args.begin() + CallArgsStart, Args.end()); return; } for (unsigned I = 0, E = ArgTypes.size(); I != E; ++I) { CallExpr::const_arg_iterator Arg = ArgBeg + I; assert(Arg != ArgEnd); EmitCallArg(Args, *Arg, ArgTypes[I]); EmitNonNullArgCheck(Args.back().RV, ArgTypes[I], Arg->getExprLoc(), CalleeDecl, ParamsToSkip + I); } } namespace { struct DestroyUnpassedArg : EHScopeStack::Cleanup { DestroyUnpassedArg(llvm::Value *Addr, QualType Ty) : Addr(Addr), Ty(Ty) {} llvm::Value *Addr; QualType Ty; void Emit(CodeGenFunction &CGF, Flags flags) override { const CXXDestructorDecl *Dtor = Ty->getAsCXXRecordDecl()->getDestructor(); assert(!Dtor->isTrivial()); CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete, /*for vbase*/ false, /*Delegating=*/false, Addr); } }; } struct DisableDebugLocationUpdates { CodeGenFunction &CGF; bool disabledDebugInfo; DisableDebugLocationUpdates(CodeGenFunction &CGF, const Expr *E) : CGF(CGF) { if ((disabledDebugInfo = isa(E) && CGF.getDebugInfo())) CGF.disableDebugInfo(); } ~DisableDebugLocationUpdates() { if (disabledDebugInfo) CGF.enableDebugInfo(); } }; void CodeGenFunction::EmitCallArg(CallArgList &args, const Expr *E, QualType type) { DisableDebugLocationUpdates Dis(*this, E); if (const ObjCIndirectCopyRestoreExpr *CRE = dyn_cast(E)) { assert(getLangOpts().ObjCAutoRefCount); assert(getContext().hasSameType(E->getType(), type)); return emitWritebackArg(*this, args, CRE); } assert(type->isReferenceType() == E->isGLValue() && "reference binding to unmaterialized r-value!"); if (E->isGLValue()) { assert(E->getObjectKind() == OK_Ordinary); return args.add(EmitReferenceBindingToExpr(E), type); } bool HasAggregateEvalKind = hasAggregateEvaluationKind(type); // In the Microsoft C++ ABI, aggregate arguments are destructed by the callee. // However, we still have to push an EH-only cleanup in case we unwind before // we make it to the call. if (HasAggregateEvalKind && CGM.getTarget().getCXXABI().areArgsDestroyedLeftToRightInCallee()) { // If we're using inalloca, use the argument memory. Otherwise, use a // temporary. AggValueSlot Slot; if (args.isUsingInAlloca()) Slot = createPlaceholderSlot(*this, type); else Slot = CreateAggTemp(type, "agg.tmp"); const CXXRecordDecl *RD = type->getAsCXXRecordDecl(); bool DestroyedInCallee = RD && RD->hasNonTrivialDestructor() && CGM.getCXXABI().getRecordArgABI(RD) != CGCXXABI::RAA_Default; if (DestroyedInCallee) Slot.setExternallyDestructed(); EmitAggExpr(E, Slot); RValue RV = Slot.asRValue(); args.add(RV, type); if (DestroyedInCallee) { // Create a no-op GEP between the placeholder and the cleanup so we can // RAUW it successfully. It also serves as a marker of the first // instruction where the cleanup is active. pushFullExprCleanup(EHCleanup, Slot.getAddr(), type); // This unreachable is a temporary marker which will be removed later. llvm::Instruction *IsActive = Builder.CreateUnreachable(); args.addArgCleanupDeactivation(EHStack.getInnermostEHScope(), IsActive); } return; } if (HasAggregateEvalKind && isa(E) && cast(E)->getCastKind() == CK_LValueToRValue) { LValue L = EmitLValue(cast(E)->getSubExpr()); assert(L.isSimple()); if (L.getAlignment() >= getContext().getTypeAlignInChars(type)) { args.add(L.asAggregateRValue(), type, /*NeedsCopy*/true); } else { // We can't represent a misaligned lvalue in the CallArgList, so copy // to an aligned temporary now. llvm::Value *tmp = CreateMemTemp(type); EmitAggregateCopy(tmp, L.getAddress(), type, L.isVolatile(), L.getAlignment()); args.add(RValue::getAggregate(tmp), type); } return; } args.add(EmitAnyExprToTemp(E), type); } QualType CodeGenFunction::getVarArgType(const Expr *Arg) { // System headers on Windows define NULL to 0 instead of 0LL on Win64. MSVC // implicitly widens null pointer constants that are arguments to varargs // functions to pointer-sized ints. if (!getTarget().getTriple().isOSWindows()) return Arg->getType(); if (Arg->getType()->isIntegerType() && getContext().getTypeSize(Arg->getType()) < getContext().getTargetInfo().getPointerWidth(0) && Arg->isNullPointerConstant(getContext(), Expr::NPC_ValueDependentIsNotNull)) { return getContext().getIntPtrType(); } return Arg->getType(); } // In ObjC ARC mode with no ObjC ARC exception safety, tell the ARC // optimizer it can aggressively ignore unwind edges. void CodeGenFunction::AddObjCARCExceptionMetadata(llvm::Instruction *Inst) { if (CGM.getCodeGenOpts().OptimizationLevel != 0 && !CGM.getCodeGenOpts().ObjCAutoRefCountExceptions) Inst->setMetadata("clang.arc.no_objc_arc_exceptions", CGM.getNoObjCARCExceptionsMetadata()); } /// Emits a call to the given no-arguments nounwind runtime function. llvm::CallInst * CodeGenFunction::EmitNounwindRuntimeCall(llvm::Value *callee, const llvm::Twine &name) { return EmitNounwindRuntimeCall(callee, None, name); } /// Emits a call to the given nounwind runtime function. llvm::CallInst * CodeGenFunction::EmitNounwindRuntimeCall(llvm::Value *callee, ArrayRef args, const llvm::Twine &name) { llvm::CallInst *call = EmitRuntimeCall(callee, args, name); call->setDoesNotThrow(); return call; } /// Emits a simple call (never an invoke) to the given no-arguments /// runtime function. llvm::CallInst * CodeGenFunction::EmitRuntimeCall(llvm::Value *callee, const llvm::Twine &name) { return EmitRuntimeCall(callee, None, name); } /// Emits a simple call (never an invoke) to the given runtime /// function. llvm::CallInst * CodeGenFunction::EmitRuntimeCall(llvm::Value *callee, ArrayRef args, const llvm::Twine &name) { llvm::CallInst *call = Builder.CreateCall(callee, args, name); call->setCallingConv(getRuntimeCC()); return call; } /// Emits a call or invoke to the given noreturn runtime function. void CodeGenFunction::EmitNoreturnRuntimeCallOrInvoke(llvm::Value *callee, ArrayRef args) { if (getInvokeDest()) { llvm::InvokeInst *invoke = Builder.CreateInvoke(callee, getUnreachableBlock(), getInvokeDest(), args); invoke->setDoesNotReturn(); invoke->setCallingConv(getRuntimeCC()); } else { llvm::CallInst *call = Builder.CreateCall(callee, args); call->setDoesNotReturn(); call->setCallingConv(getRuntimeCC()); Builder.CreateUnreachable(); } } /// Emits a call or invoke instruction to the given nullary runtime /// function. llvm::CallSite CodeGenFunction::EmitRuntimeCallOrInvoke(llvm::Value *callee, const Twine &name) { return EmitRuntimeCallOrInvoke(callee, None, name); } /// Emits a call or invoke instruction to the given runtime function. llvm::CallSite CodeGenFunction::EmitRuntimeCallOrInvoke(llvm::Value *callee, ArrayRef args, const Twine &name) { llvm::CallSite callSite = EmitCallOrInvoke(callee, args, name); callSite.setCallingConv(getRuntimeCC()); return callSite; } llvm::CallSite CodeGenFunction::EmitCallOrInvoke(llvm::Value *Callee, const Twine &Name) { return EmitCallOrInvoke(Callee, None, Name); } /// 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, ArrayRef Args, const Twine &Name) { llvm::BasicBlock *InvokeDest = getInvokeDest(); llvm::Instruction *Inst; if (!InvokeDest) Inst = Builder.CreateCall(Callee, Args, Name); else { llvm::BasicBlock *ContBB = createBasicBlock("invoke.cont"); Inst = Builder.CreateInvoke(Callee, ContBB, InvokeDest, Args, Name); EmitBlock(ContBB); } // In ObjC ARC mode with no ObjC ARC exception safety, tell the ARC // optimizer it can aggressively ignore unwind edges. if (CGM.getLangOpts().ObjCAutoRefCount) AddObjCARCExceptionMetadata(Inst); return llvm::CallSite(Inst); } /// \brief Store a non-aggregate value to an address to initialize it. For /// initialization, a non-atomic store will be used. static void EmitInitStoreOfNonAggregate(CodeGenFunction &CGF, RValue Src, LValue Dst) { if (Src.isScalar()) CGF.EmitStoreOfScalar(Src.getScalarVal(), Dst, /*init=*/true); else CGF.EmitStoreOfComplex(Src.getComplexVal(), Dst, /*init=*/true); } void CodeGenFunction::deferPlaceholderReplacement(llvm::Instruction *Old, llvm::Value *New) { DeferredReplacements.push_back(std::make_pair(Old, New)); } 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. // 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(); llvm::FunctionType *IRFuncTy = cast( cast(Callee->getType())->getElementType()); // If we're using inalloca, insert the allocation after the stack save. // FIXME: Do this earlier rather than hacking it in here! llvm::AllocaInst *ArgMemory = nullptr; if (llvm::StructType *ArgStruct = CallInfo.getArgStruct()) { llvm::Instruction *IP = CallArgs.getStackBase(); llvm::AllocaInst *AI; if (IP) { IP = IP->getNextNode(); AI = new llvm::AllocaInst(ArgStruct, "argmem", IP); } else { AI = CreateTempAlloca(ArgStruct, "argmem"); } AI->setUsedWithInAlloca(true); assert(AI->isUsedWithInAlloca() && !AI->isStaticAlloca()); ArgMemory = AI; } ClangToLLVMArgMapping IRFunctionArgs(CGM.getContext(), CallInfo); SmallVector IRCallArgs(IRFunctionArgs.totalIRArgs()); // If the call returns a temporary with struct return, create a temporary // alloca to hold the result, unless one is given to us. llvm::Value *SRetPtr = nullptr; size_t UnusedReturnSize = 0; if (RetAI.isIndirect() || RetAI.isInAlloca()) { SRetPtr = ReturnValue.getValue(); if (!SRetPtr) { SRetPtr = CreateMemTemp(RetTy); if (HaveInsertPoint() && ReturnValue.isUnused()) { uint64_t size = CGM.getDataLayout().getTypeAllocSize(ConvertTypeForMem(RetTy)); if (EmitLifetimeStart(size, SRetPtr)) UnusedReturnSize = size; } } if (IRFunctionArgs.hasSRetArg()) { IRCallArgs[IRFunctionArgs.getSRetArgNo()] = SRetPtr; } else { llvm::Value *Addr = Builder.CreateStructGEP(ArgMemory->getAllocatedType(), ArgMemory, RetAI.getInAllocaFieldIndex()); Builder.CreateStore(SRetPtr, Addr); } } assert(CallInfo.arg_size() == CallArgs.size() && "Mismatch between function signature & arguments."); unsigned ArgNo = 0; CGFunctionInfo::const_arg_iterator info_it = CallInfo.arg_begin(); for (CallArgList::const_iterator I = CallArgs.begin(), E = CallArgs.end(); I != E; ++I, ++info_it, ++ArgNo) { const ABIArgInfo &ArgInfo = info_it->info; RValue RV = I->RV; CharUnits TypeAlign = getContext().getTypeAlignInChars(I->Ty); // Insert a padding argument to ensure proper alignment. if (IRFunctionArgs.hasPaddingArg(ArgNo)) IRCallArgs[IRFunctionArgs.getPaddingArgNo(ArgNo)] = llvm::UndefValue::get(ArgInfo.getPaddingType()); unsigned FirstIRArg, NumIRArgs; std::tie(FirstIRArg, NumIRArgs) = IRFunctionArgs.getIRArgs(ArgNo); switch (ArgInfo.getKind()) { case ABIArgInfo::InAlloca: { assert(NumIRArgs == 0); assert(getTarget().getTriple().getArch() == llvm::Triple::x86); if (RV.isAggregate()) { // Replace the placeholder with the appropriate argument slot GEP. llvm::Instruction *Placeholder = cast(RV.getAggregateAddr()); CGBuilderTy::InsertPoint IP = Builder.saveIP(); Builder.SetInsertPoint(Placeholder); llvm::Value *Addr = Builder.CreateStructGEP(ArgMemory->getAllocatedType(), ArgMemory, ArgInfo.getInAllocaFieldIndex()); Builder.restoreIP(IP); deferPlaceholderReplacement(Placeholder, Addr); } else { // Store the RValue into the argument struct. llvm::Value *Addr = Builder.CreateStructGEP(ArgMemory->getAllocatedType(), ArgMemory, ArgInfo.getInAllocaFieldIndex()); unsigned AS = Addr->getType()->getPointerAddressSpace(); llvm::Type *MemType = ConvertTypeForMem(I->Ty)->getPointerTo(AS); // There are some cases where a trivial bitcast is not avoidable. The // definition of a type later in a translation unit may change it's type // from {}* to (%struct.foo*)*. if (Addr->getType() != MemType) Addr = Builder.CreateBitCast(Addr, MemType); LValue argLV = MakeAddrLValue(Addr, I->Ty, TypeAlign); EmitInitStoreOfNonAggregate(*this, RV, argLV); } break; } case ABIArgInfo::Indirect: { assert(NumIRArgs == 1); 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()); IRCallArgs[FirstIRArg] = AI; LValue argLV = MakeAddrLValue(AI, I->Ty, TypeAlign); EmitInitStoreOfNonAggregate(*this, RV, argLV); } else { // We want to avoid creating an unnecessary temporary+copy here; // however, we need one in three 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. // 3. If the argument is byval, but RV is located in an address space // different than that of the argument (0). llvm::Value *Addr = RV.getAggregateAddr(); unsigned Align = ArgInfo.getIndirectAlign(); const llvm::DataLayout *TD = &CGM.getDataLayout(); const unsigned RVAddrSpace = Addr->getType()->getPointerAddressSpace(); const unsigned ArgAddrSpace = (FirstIRArg < IRFuncTy->getNumParams() ? IRFuncTy->getParamType(FirstIRArg)->getPointerAddressSpace() : 0); if ((!ArgInfo.getIndirectByVal() && I->NeedsCopy) || (ArgInfo.getIndirectByVal() && TypeAlign.getQuantity() < Align && llvm::getOrEnforceKnownAlignment(Addr, Align, *TD) < Align) || (ArgInfo.getIndirectByVal() && (RVAddrSpace != ArgAddrSpace))) { // Create an aligned temporary, and copy to it. llvm::AllocaInst *AI = CreateMemTemp(I->Ty); if (Align > AI->getAlignment()) AI->setAlignment(Align); IRCallArgs[FirstIRArg] = AI; EmitAggregateCopy(AI, Addr, I->Ty, RV.isVolatileQualified()); } else { // Skip the extra memcpy call. IRCallArgs[FirstIRArg] = Addr; } } break; } case ABIArgInfo::Ignore: assert(NumIRArgs == 0); break; case ABIArgInfo::Extend: case ABIArgInfo::Direct: { if (!isa(ArgInfo.getCoerceToType()) && ArgInfo.getCoerceToType() == ConvertType(info_it->type) && ArgInfo.getDirectOffset() == 0) { assert(NumIRArgs == 1); llvm::Value *V; if (RV.isScalar()) V = RV.getScalarVal(); else V = Builder.CreateLoad(RV.getAggregateAddr()); // We might have to widen integers, but we should never truncate. if (ArgInfo.getCoerceToType() != V->getType() && V->getType()->isIntegerTy()) V = Builder.CreateZExt(V, ArgInfo.getCoerceToType()); // If the argument doesn't match, perform a bitcast to coerce it. This // can happen due to trivial type mismatches. if (FirstIRArg < IRFuncTy->getNumParams() && V->getType() != IRFuncTy->getParamType(FirstIRArg)) V = Builder.CreateBitCast(V, IRFuncTy->getParamType(FirstIRArg)); IRCallArgs[FirstIRArg] = V; break; } // FIXME: Avoid the conversion through memory if possible. llvm::Value *SrcPtr; CharUnits SrcAlign; if (RV.isScalar() || RV.isComplex()) { SrcPtr = CreateMemTemp(I->Ty, "coerce"); SrcAlign = TypeAlign; LValue SrcLV = MakeAddrLValue(SrcPtr, I->Ty, TypeAlign); EmitInitStoreOfNonAggregate(*this, RV, SrcLV); } else { SrcPtr = RV.getAggregateAddr(); // This alignment is guaranteed by EmitCallArg. SrcAlign = TypeAlign; } // 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(Builder.getInt8Ty(), SrcPtr, Offs); SrcPtr = Builder.CreateBitCast(SrcPtr, llvm::PointerType::getUnqual(ArgInfo.getCoerceToType())); SrcAlign = SrcAlign.alignmentAtOffset(CharUnits::fromQuantity(Offs)); } // Fast-isel and the optimizer generally like scalar values better than // FCAs, so we flatten them if this is safe to do for this argument. llvm::StructType *STy = dyn_cast(ArgInfo.getCoerceToType()); if (STy && ArgInfo.isDirect() && ArgInfo.getCanBeFlattened()) { llvm::Type *SrcTy = cast(SrcPtr->getType())->getElementType(); uint64_t SrcSize = CGM.getDataLayout().getTypeAllocSize(SrcTy); uint64_t DstSize = CGM.getDataLayout().getTypeAllocSize(STy); // If the source type is smaller than the destination type of the // coerce-to logic, copy the source value into a temp alloca the size // of the destination type to allow loading all of it. The bits past // the source value are left undef. if (SrcSize < DstSize) { llvm::AllocaInst *TempAlloca = CreateTempAlloca(STy, SrcPtr->getName() + ".coerce"); Builder.CreateMemCpy(TempAlloca, SrcPtr, SrcSize, 0); SrcPtr = TempAlloca; } else { SrcPtr = Builder.CreateBitCast(SrcPtr, llvm::PointerType::getUnqual(STy)); } assert(NumIRArgs == STy->getNumElements()); for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { llvm::Value *EltPtr = Builder.CreateConstGEP2_32(STy, SrcPtr, 0, i); llvm::LoadInst *LI = Builder.CreateLoad(EltPtr); // We don't know what we're loading from. LI->setAlignment(1); IRCallArgs[FirstIRArg + i] = LI; } } else { // In the simple case, just pass the coerced loaded value. assert(NumIRArgs == 1); IRCallArgs[FirstIRArg] = CreateCoercedLoad(SrcPtr, ArgInfo.getCoerceToType(), SrcAlign, *this); } break; } case ABIArgInfo::Expand: unsigned IRArgPos = FirstIRArg; ExpandTypeToArgs(I->Ty, RV, IRFuncTy, IRCallArgs, IRArgPos); assert(IRArgPos == FirstIRArg + NumIRArgs); break; } } if (ArgMemory) { llvm::Value *Arg = ArgMemory; if (CallInfo.isVariadic()) { // When passing non-POD arguments by value to variadic functions, we will // end up with a variadic prototype and an inalloca call site. In such // cases, we can't do any parameter mismatch checks. Give up and bitcast // the callee. unsigned CalleeAS = cast(Callee->getType())->getAddressSpace(); Callee = Builder.CreateBitCast( Callee, getTypes().GetFunctionType(CallInfo)->getPointerTo(CalleeAS)); } else { llvm::Type *LastParamTy = IRFuncTy->getParamType(IRFuncTy->getNumParams() - 1); if (Arg->getType() != LastParamTy) { #ifndef NDEBUG // Assert that these structs have equivalent element types. llvm::StructType *FullTy = CallInfo.getArgStruct(); llvm::StructType *DeclaredTy = cast( cast(LastParamTy)->getElementType()); assert(DeclaredTy->getNumElements() == FullTy->getNumElements()); for (llvm::StructType::element_iterator DI = DeclaredTy->element_begin(), DE = DeclaredTy->element_end(), FI = FullTy->element_begin(); DI != DE; ++DI, ++FI) assert(*DI == *FI); #endif Arg = Builder.CreateBitCast(Arg, LastParamTy); } } assert(IRFunctionArgs.hasInallocaArg()); IRCallArgs[IRFunctionArgs.getInallocaArgNo()] = Arg; } if (!CallArgs.getCleanupsToDeactivate().empty()) deactivateArgCleanupsBeforeCall(*this, CallArgs); // 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))) { llvm::PointerType *CurPT=cast(Callee->getType()); llvm::FunctionType *CurFT = cast(CurPT->getElementType()); llvm::FunctionType *ActualFT = CalleeF->getFunctionType(); if (CE->getOpcode() == llvm::Instruction::BitCast && ActualFT->getReturnType() == CurFT->getReturnType() && ActualFT->getNumParams() == CurFT->getNumParams() && ActualFT->getNumParams() == IRCallArgs.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; } } assert(IRCallArgs.size() == IRFuncTy->getNumParams() || IRFuncTy->isVarArg()); for (unsigned i = 0; i < IRCallArgs.size(); ++i) { // Inalloca argument can have different type. if (IRFunctionArgs.hasInallocaArg() && i == IRFunctionArgs.getInallocaArgNo()) continue; if (i < IRFuncTy->getNumParams()) assert(IRCallArgs[i]->getType() == IRFuncTy->getParamType(i)); } unsigned CallingConv; CodeGen::AttributeListType AttributeList; CGM.ConstructAttributeList(CallInfo, TargetDecl, AttributeList, CallingConv, true); llvm::AttributeSet Attrs = llvm::AttributeSet::get(getLLVMContext(), AttributeList); llvm::BasicBlock *InvokeDest = nullptr; if (!Attrs.hasAttribute(llvm::AttributeSet::FunctionIndex, llvm::Attribute::NoUnwind) || currentFunctionUsesSEHTry()) InvokeDest = getInvokeDest(); llvm::CallSite CS; if (!InvokeDest) { CS = Builder.CreateCall(Callee, IRCallArgs); } else { llvm::BasicBlock *Cont = createBasicBlock("invoke.cont"); CS = Builder.CreateInvoke(Callee, Cont, InvokeDest, IRCallArgs); EmitBlock(Cont); } if (callOrInvoke) *callOrInvoke = CS.getInstruction(); if (CurCodeDecl && CurCodeDecl->hasAttr() && !CS.hasFnAttr(llvm::Attribute::NoInline)) Attrs = Attrs.addAttribute(getLLVMContext(), llvm::AttributeSet::FunctionIndex, llvm::Attribute::AlwaysInline); // Disable inlining inside SEH __try blocks. if (isSEHTryScope()) Attrs = Attrs.addAttribute(getLLVMContext(), llvm::AttributeSet::FunctionIndex, llvm::Attribute::NoInline); CS.setAttributes(Attrs); CS.setCallingConv(static_cast(CallingConv)); // In ObjC ARC mode with no ObjC ARC exception safety, tell the ARC // optimizer it can aggressively ignore unwind edges. if (CGM.getLangOpts().ObjCAutoRefCount) AddObjCARCExceptionMetadata(CS.getInstruction()); // 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()) { if (UnusedReturnSize) EmitLifetimeEnd(llvm::ConstantInt::get(Int64Ty, UnusedReturnSize), SRetPtr); 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); // The stack cleanup for inalloca arguments has to run out of the normal // lexical order, so deactivate it and run it manually here. CallArgs.freeArgumentMemory(*this); RValue Ret = [&] { switch (RetAI.getKind()) { case ABIArgInfo::InAlloca: case ABIArgInfo::Indirect: { RValue ret = convertTempToRValue(SRetPtr, RetTy, SourceLocation()); if (UnusedReturnSize) EmitLifetimeEnd(llvm::ConstantInt::get(Int64Ty, UnusedReturnSize), SRetPtr); return ret; } 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) { switch (getEvaluationKind(RetTy)) { case TEK_Complex: { llvm::Value *Real = Builder.CreateExtractValue(CI, 0); llvm::Value *Imag = Builder.CreateExtractValue(CI, 1); return RValue::getComplex(std::make_pair(Real, Imag)); } case TEK_Aggregate: { llvm::Value *DestPtr = ReturnValue.getValue(); bool DestIsVolatile = ReturnValue.isVolatile(); CharUnits DestAlign = getContext().getTypeAlignInChars(RetTy); if (!DestPtr) { DestPtr = CreateMemTemp(RetTy, "agg.tmp"); DestIsVolatile = false; } BuildAggStore(*this, CI, DestPtr, DestIsVolatile, DestAlign); return RValue::getAggregate(DestPtr); } case TEK_Scalar: { // 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_unreachable("bad evaluation kind"); } llvm::Value *DestPtr = ReturnValue.getValue(); bool DestIsVolatile = ReturnValue.isVolatile(); CharUnits DestAlign = getContext().getTypeAlignInChars(RetTy); if (!DestPtr) { DestPtr = CreateMemTemp(RetTy, "coerce"); DestIsVolatile = false; } // If the value is offset in memory, apply the offset now. llvm::Value *StorePtr = DestPtr; CharUnits StoreAlign = DestAlign; if (unsigned Offs = RetAI.getDirectOffset()) { StorePtr = Builder.CreateBitCast(StorePtr, Builder.getInt8PtrTy()); StorePtr = Builder.CreateConstGEP1_32(Builder.getInt8Ty(), StorePtr, Offs); StorePtr = Builder.CreateBitCast(StorePtr, llvm::PointerType::getUnqual(RetAI.getCoerceToType())); StoreAlign = StoreAlign.alignmentAtOffset(CharUnits::fromQuantity(Offs)); } CreateCoercedStore(CI, StorePtr, DestIsVolatile, StoreAlign, *this); return convertTempToRValue(DestPtr, RetTy, SourceLocation()); } case ABIArgInfo::Expand: llvm_unreachable("Invalid ABI kind for return argument"); } llvm_unreachable("Unhandled ABIArgInfo::Kind"); } (); if (Ret.isScalar() && TargetDecl) { if (const auto *AA = TargetDecl->getAttr()) { llvm::Value *OffsetValue = nullptr; if (const auto *Offset = AA->getOffset()) OffsetValue = EmitScalarExpr(Offset); llvm::Value *Alignment = EmitScalarExpr(AA->getAlignment()); llvm::ConstantInt *AlignmentCI = cast(Alignment); EmitAlignmentAssumption(Ret.getScalarVal(), AlignmentCI->getZExtValue(), OffsetValue); } } return Ret; } /* VarArg handling */ llvm::Value *CodeGenFunction::EmitVAArg(llvm::Value *VAListAddr, QualType Ty) { return CGM.getTypes().getABIInfo().EmitVAArg(VAListAddr, Ty, *this); }