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Diffstat (limited to 'clang/lib/CodeGen/CGCall.cpp')
| -rw-r--r-- | clang/lib/CodeGen/CGCall.cpp | 2201 |
1 files changed, 2201 insertions, 0 deletions
diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp new file mode 100644 index 0000000..82ee4fc --- /dev/null +++ b/clang/lib/CodeGen/CGCall.cpp @@ -0,0 +1,2201 @@ +//===--- CGCall.cpp - Encapsulate calling convention details ----*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// These classes wrap the information about a call or function +// definition used to handle ABI compliancy. +// +//===----------------------------------------------------------------------===// + +#include "CGCall.h" +#include "CGCXXABI.h" +#include "ABIInfo.h" +#include "CodeGenFunction.h" +#include "CodeGenModule.h" +#include "TargetInfo.h" +#include "clang/Basic/TargetInfo.h" +#include "clang/AST/Decl.h" +#include "clang/AST/DeclCXX.h" +#include "clang/AST/DeclObjC.h" +#include "clang/Frontend/CodeGenOptions.h" +#include "llvm/Attributes.h" +#include "llvm/Support/CallSite.h" +#include "llvm/Target/TargetData.h" +#include "llvm/InlineAsm.h" +#include "llvm/Transforms/Utils/Local.h" +using namespace clang; +using namespace CodeGen; + +/***/ + +static unsigned ClangCallConvToLLVMCallConv(CallingConv CC) { + switch (CC) { + default: return llvm::CallingConv::C; + case CC_X86StdCall: return llvm::CallingConv::X86_StdCall; + case CC_X86FastCall: return llvm::CallingConv::X86_FastCall; + case CC_X86ThisCall: return llvm::CallingConv::X86_ThisCall; + case CC_AAPCS: return llvm::CallingConv::ARM_AAPCS; + case CC_AAPCS_VFP: return llvm::CallingConv::ARM_AAPCS_VFP; + // TODO: add support for CC_X86Pascal to llvm + } +} + +/// Derives the 'this' type for codegen purposes, i.e. ignoring method +/// qualification. +/// FIXME: address space qualification? +static CanQualType GetThisType(ASTContext &Context, const CXXRecordDecl *RD) { + QualType RecTy = Context.getTagDeclType(RD)->getCanonicalTypeInternal(); + return Context.getPointerType(CanQualType::CreateUnsafe(RecTy)); +} + +/// Returns the canonical formal type of the given C++ method. +static CanQual<FunctionProtoType> GetFormalType(const CXXMethodDecl *MD) { + return MD->getType()->getCanonicalTypeUnqualified() + .getAs<FunctionProtoType>(); +} + +/// 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 function type. +const CGFunctionInfo & +CodeGenTypes::arrangeFunctionType(CanQual<FunctionNoProtoType> FTNP) { + // When translating an unprototyped function type, always use a + // variadic type. + return arrangeFunctionType(FTNP->getResultType().getUnqualifiedType(), + ArrayRef<CanQualType>(), + FTNP->getExtInfo(), + RequiredArgs(0)); +} + +/// Arrange the argument and result information for a value of the +/// given function type, on top of any implicit parameters already +/// stored. +static const CGFunctionInfo &arrangeFunctionType(CodeGenTypes &CGT, + SmallVectorImpl<CanQualType> &argTypes, + CanQual<FunctionProtoType> FTP) { + RequiredArgs required = RequiredArgs::forPrototypePlus(FTP, argTypes.size()); + // FIXME: Kill copy. + for (unsigned i = 0, e = FTP->getNumArgs(); i != e; ++i) + argTypes.push_back(FTP->getArgType(i)); + CanQualType resultType = FTP->getResultType().getUnqualifiedType(); + return CGT.arrangeFunctionType(resultType, argTypes, + FTP->getExtInfo(), required); +} + +/// Arrange the argument and result information for a value of the +/// given function type. +const CGFunctionInfo & +CodeGenTypes::arrangeFunctionType(CanQual<FunctionProtoType> FTP) { + SmallVector<CanQualType, 16> argTypes; + return ::arrangeFunctionType(*this, argTypes, FTP); +} + +static CallingConv getCallingConventionForDecl(const Decl *D) { + // Set the appropriate calling convention for the Function. + if (D->hasAttr<StdCallAttr>()) + return CC_X86StdCall; + + if (D->hasAttr<FastCallAttr>()) + return CC_X86FastCall; + + if (D->hasAttr<ThisCallAttr>()) + return CC_X86ThisCall; + + if (D->hasAttr<PascalAttr>()) + return CC_X86Pascal; + + if (PcsAttr *PCS = D->getAttr<PcsAttr>()) + return (PCS->getPCS() == PcsAttr::AAPCS ? CC_AAPCS : CC_AAPCS_VFP); + + 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. +/// 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<CanQualType, 16> argTypes; + + // Add the 'this' pointer. + argTypes.push_back(GetThisType(Context, RD)); + + return ::arrangeFunctionType(*this, argTypes, + FTP->getCanonicalTypeUnqualified().getAs<FunctionProtoType>()); +} + +/// 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<CXXConstructorDecl>(MD) && "wrong method for contructors!"); + assert(!isa<CXXDestructorDecl>(MD) && "wrong method for destructors!"); + + CanQual<FunctionProtoType> prototype = GetFormalType(MD); + + if (MD->isInstance()) { + // The abstract case is perfectly fine. + return arrangeCXXMethodType(MD->getParent(), prototype.getTypePtr()); + } + + return arrangeFunctionType(prototype); +} + +/// Arrange the argument and result information for a declaration +/// or definition to the given constructor variant. +const CGFunctionInfo & +CodeGenTypes::arrangeCXXConstructorDeclaration(const CXXConstructorDecl *D, + CXXCtorType ctorKind) { + SmallVector<CanQualType, 16> argTypes; + argTypes.push_back(GetThisType(Context, D->getParent())); + CanQualType resultType = Context.VoidTy; + + TheCXXABI.BuildConstructorSignature(D, ctorKind, resultType, argTypes); + + CanQual<FunctionProtoType> FTP = GetFormalType(D); + + RequiredArgs required = RequiredArgs::forPrototypePlus(FTP, argTypes.size()); + + // Add the formal parameters. + for (unsigned i = 0, e = FTP->getNumArgs(); i != e; ++i) + argTypes.push_back(FTP->getArgType(i)); + + return arrangeFunctionType(resultType, argTypes, FTP->getExtInfo(), required); +} + +/// Arrange the argument and result information for a declaration, +/// definition, or call to the given destructor variant. It so +/// happens that all three cases produce the same information. +const CGFunctionInfo & +CodeGenTypes::arrangeCXXDestructor(const CXXDestructorDecl *D, + CXXDtorType dtorKind) { + SmallVector<CanQualType, 2> argTypes; + argTypes.push_back(GetThisType(Context, D->getParent())); + CanQualType resultType = Context.VoidTy; + + TheCXXABI.BuildDestructorSignature(D, dtorKind, resultType, argTypes); + + CanQual<FunctionProtoType> FTP = GetFormalType(D); + assert(FTP->getNumArgs() == 0 && "dtor with formal parameters"); + + return arrangeFunctionType(resultType, argTypes, FTP->getExtInfo(), + RequiredArgs::All); +} + +/// 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<CXXMethodDecl>(FD)) + if (MD->isInstance()) + return arrangeCXXMethodDeclaration(MD); + + CanQualType FTy = FD->getType()->getCanonicalTypeUnqualified(); + + assert(isa<FunctionType>(FTy)); + + // When declaring a function without a prototype, always use a + // non-variadic type. + if (isa<FunctionNoProtoType>(FTy)) { + CanQual<FunctionNoProtoType> noProto = FTy.getAs<FunctionNoProtoType>(); + return arrangeFunctionType(noProto->getResultType(), + ArrayRef<CanQualType>(), + noProto->getExtInfo(), + RequiredArgs::All); + } + + assert(isa<FunctionProtoType>(FTy)); + return arrangeFunctionType(FTy.getAs<FunctionProtoType>()); +} + +/// 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<CanQualType, 16> argTys; + argTys.push_back(Context.getCanonicalParamType(receiverType)); + argTys.push_back(Context.getCanonicalParamType(Context.getObjCSelType())); + // FIXME: Kill copy? + for (ObjCMethodDecl::param_const_iterator i = MD->param_begin(), + e = MD->param_end(); i != e; ++i) { + argTys.push_back(Context.getCanonicalParamType((*i)->getType())); + } + + FunctionType::ExtInfo einfo; + einfo = einfo.withCallingConv(getCallingConventionForDecl(MD)); + + if (getContext().getLangOpts().ObjCAutoRefCount && + MD->hasAttr<NSReturnsRetainedAttr>()) + einfo = einfo.withProducesResult(true); + + RequiredArgs required = + (MD->isVariadic() ? RequiredArgs(argTys.size()) : RequiredArgs::All); + + return arrangeFunctionType(GetReturnType(MD->getResultType()), argTys, + einfo, required); +} + +const CGFunctionInfo & +CodeGenTypes::arrangeGlobalDeclaration(GlobalDecl GD) { + // FIXME: Do we need to handle ObjCMethodDecl? + const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); + + if (const CXXConstructorDecl *CD = dyn_cast<CXXConstructorDecl>(FD)) + return arrangeCXXConstructorDeclaration(CD, GD.getCtorType()); + + if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(FD)) + return arrangeCXXDestructor(DD, GD.getDtorType()); + + return arrangeFunctionDeclaration(FD); +} + +/// 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::arrangeFunctionCall(const CallArgList &args, + const FunctionType *fnType) { + RequiredArgs required = RequiredArgs::All; + if (const FunctionProtoType *proto = dyn_cast<FunctionProtoType>(fnType)) { + if (proto->isVariadic()) + required = RequiredArgs(proto->getNumArgs()); + } else if (CGM.getTargetCodeGenInfo() + .isNoProtoCallVariadic(args, cast<FunctionNoProtoType>(fnType))) { + required = RequiredArgs(0); + } + + return arrangeFunctionCall(fnType->getResultType(), args, + fnType->getExtInfo(), required); +} + +const CGFunctionInfo & +CodeGenTypes::arrangeFunctionCall(QualType resultType, + const CallArgList &args, + const FunctionType::ExtInfo &info, + RequiredArgs required) { + // FIXME: Kill copy. + SmallVector<CanQualType, 16> argTypes; + for (CallArgList::const_iterator i = args.begin(), e = args.end(); + i != e; ++i) + argTypes.push_back(Context.getCanonicalParamType(i->Ty)); + return arrangeFunctionType(GetReturnType(resultType), argTypes, info, + required); +} + +const CGFunctionInfo & +CodeGenTypes::arrangeFunctionDeclaration(QualType resultType, + const FunctionArgList &args, + const FunctionType::ExtInfo &info, + bool isVariadic) { + // FIXME: Kill copy. + SmallVector<CanQualType, 16> argTypes; + for (FunctionArgList::const_iterator i = args.begin(), e = args.end(); + i != e; ++i) + argTypes.push_back(Context.getCanonicalParamType((*i)->getType())); + + RequiredArgs required = + (isVariadic ? RequiredArgs(args.size()) : RequiredArgs::All); + return arrangeFunctionType(GetReturnType(resultType), argTypes, info, + required); +} + +const CGFunctionInfo &CodeGenTypes::arrangeNullaryFunction() { + return arrangeFunctionType(getContext().VoidTy, ArrayRef<CanQualType>(), + 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::arrangeFunctionType(CanQualType resultType, + ArrayRef<CanQualType> argTypes, + const FunctionType::ExtInfo &info, + RequiredArgs required) { +#ifndef NDEBUG + for (ArrayRef<CanQualType>::const_iterator + I = argTypes.begin(), E = argTypes.end(); I != E; ++I) + assert(I->isCanonicalAsParam()); +#endif + + unsigned CC = ClangCallConvToLLVMCallConv(info.getCC()); + + // Lookup or create unique function info. + llvm::FoldingSetNodeID ID; + CGFunctionInfo::Profile(ID, info, required, resultType, argTypes); + + void *insertPos = 0; + CGFunctionInfo *FI = FunctionInfos.FindNodeOrInsertPos(ID, insertPos); + if (FI) + return *FI; + + // Construct the function info. We co-allocate the ArgInfos. + FI = CGFunctionInfo::create(CC, info, resultType, argTypes, required); + FunctionInfos.InsertNode(FI, insertPos); + + bool inserted = FunctionsBeingProcessed.insert(FI); (void)inserted; + assert(inserted && "Recursively being processed?"); + + // Compute ABI information. + getABIInfo().computeInfo(*FI); + + // Loop over all of the computed argument and return value info. If any of + // them are direct or extend without a specified coerce type, specify the + // default now. + ABIArgInfo &retInfo = FI->getReturnInfo(); + if (retInfo.canHaveCoerceToType() && retInfo.getCoerceToType() == 0) + retInfo.setCoerceToType(ConvertType(FI->getReturnType())); + + for (CGFunctionInfo::arg_iterator I = FI->arg_begin(), E = FI->arg_end(); + I != E; ++I) + if (I->info.canHaveCoerceToType() && I->info.getCoerceToType() == 0) + I->info.setCoerceToType(ConvertType(I->type)); + + bool erased = FunctionsBeingProcessed.erase(FI); (void)erased; + assert(erased && "Not in set?"); + + return *FI; +} + +CGFunctionInfo *CGFunctionInfo::create(unsigned llvmCC, + const FunctionType::ExtInfo &info, + CanQualType resultType, + ArrayRef<CanQualType> 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->NoReturn = info.getNoReturn(); + FI->ReturnsRetained = info.getProducesResult(); + FI->Required = required; + FI->HasRegParm = info.getHasRegParm(); + FI->RegParm = info.getRegParm(); + 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; +} + +/***/ + +void CodeGenTypes::GetExpandedTypes(QualType type, + SmallVectorImpl<llvm::Type*> &expandedTypes) { + if (const ConstantArrayType *AT = Context.getAsConstantArrayType(type)) { + uint64_t NumElts = AT->getSize().getZExtValue(); + for (uint64_t Elt = 0; Elt < NumElts; ++Elt) + GetExpandedTypes(AT->getElementType(), expandedTypes); + } else if (const RecordType *RT = type->getAs<RecordType>()) { + 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 = 0; + CharUnits UnionSize = CharUnits::Zero(); + + for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); + i != e; ++i) { + const FieldDecl *FD = *i; + assert(!FD->isBitField() && + "Cannot expand structure with bit-field members."); + CharUnits FieldSize = getContext().getTypeSizeInChars(FD->getType()); + if (UnionSize < FieldSize) { + UnionSize = FieldSize; + LargestFD = FD; + } + } + if (LargestFD) + GetExpandedTypes(LargestFD->getType(), expandedTypes); + } else { + for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); + i != e; ++i) { + const FieldDecl *FD = *i; + assert(!FD->isBitField() && + "Cannot expand structure with bit-field members."); + GetExpandedTypes(FD->getType(), expandedTypes); + } + } + } else if (const ComplexType *CT = type->getAs<ComplexType>()) { + llvm::Type *EltTy = ConvertType(CT->getElementType()); + expandedTypes.push_back(EltTy); + expandedTypes.push_back(EltTy); + } else + expandedTypes.push_back(ConvertType(type)); +} + +llvm::Function::arg_iterator +CodeGenFunction::ExpandTypeFromArgs(QualType Ty, LValue LV, + llvm::Function::arg_iterator AI) { + assert(LV.isSimple() && + "Unexpected non-simple lvalue during struct expansion."); + + if (const ConstantArrayType *AT = getContext().getAsConstantArrayType(Ty)) { + unsigned NumElts = AT->getSize().getZExtValue(); + QualType EltTy = AT->getElementType(); + for (unsigned Elt = 0; Elt < NumElts; ++Elt) { + llvm::Value *EltAddr = Builder.CreateConstGEP2_32(LV.getAddress(), 0, Elt); + LValue LV = MakeAddrLValue(EltAddr, EltTy); + AI = ExpandTypeFromArgs(EltTy, LV, AI); + } + } else if (const RecordType *RT = Ty->getAs<RecordType>()) { + RecordDecl *RD = RT->getDecl(); + 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 = 0; + CharUnits UnionSize = CharUnits::Zero(); + + for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); + i != e; ++i) { + const FieldDecl *FD = *i; + assert(!FD->isBitField() && + "Cannot expand structure with bit-field members."); + CharUnits FieldSize = getContext().getTypeSizeInChars(FD->getType()); + if (UnionSize < FieldSize) { + UnionSize = FieldSize; + LargestFD = FD; + } + } + if (LargestFD) { + // FIXME: What are the right qualifiers here? + LValue SubLV = EmitLValueForField(LV, LargestFD); + AI = ExpandTypeFromArgs(LargestFD->getType(), SubLV, AI); + } + } else { + for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); + i != e; ++i) { + FieldDecl *FD = *i; + QualType FT = FD->getType(); + + // FIXME: What are the right qualifiers here? + LValue SubLV = EmitLValueForField(LV, FD); + AI = ExpandTypeFromArgs(FT, SubLV, AI); + } + } + } else if (const ComplexType *CT = Ty->getAs<ComplexType>()) { + QualType EltTy = CT->getElementType(); + llvm::Value *RealAddr = Builder.CreateStructGEP(LV.getAddress(), 0, "real"); + EmitStoreThroughLValue(RValue::get(AI++), MakeAddrLValue(RealAddr, EltTy)); + llvm::Value *ImagAddr = Builder.CreateStructGEP(LV.getAddress(), 1, "imag"); + EmitStoreThroughLValue(RValue::get(AI++), MakeAddrLValue(ImagAddr, EltTy)); + } else { + EmitStoreThroughLValue(RValue::get(AI), LV); + ++AI; + } + + return AI; +} + +/// EnterStructPointerForCoercedAccess - Given a struct pointer that we are +/// accessing some number of bytes out of it, try to gep into the struct to get +/// at its inner goodness. Dive as deep as possible without entering an element +/// with an in-memory size smaller than DstSize. +static llvm::Value * +EnterStructPointerForCoercedAccess(llvm::Value *SrcPtr, + 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. + uint64_t FirstEltSize = + CGF.CGM.getTargetData().getTypeAllocSize(FirstElt); + if (FirstEltSize < DstSize && + FirstEltSize < CGF.CGM.getTargetData().getTypeAllocSize(SrcSTy)) + return SrcPtr; + + // GEP into the first element. + SrcPtr = CGF.Builder.CreateConstGEP2_32(SrcPtr, 0, 0, "coerce.dive"); + + // If the first element is a struct, recurse. + llvm::Type *SrcTy = + cast<llvm::PointerType>(SrcPtr->getType())->getElementType(); + if (llvm::StructType *SrcSTy = dyn_cast<llvm::StructType>(SrcTy)) + return EnterStructPointerForCoercedAccess(SrcPtr, SrcSTy, DstSize, CGF); + + return SrcPtr; +} + +/// CoerceIntOrPtrToIntOrPtr - Convert a value Val to the specific Ty where both +/// are either integers or pointers. This does a truncation of the value if it +/// is too large or a zero extension if it is too small. +static llvm::Value *CoerceIntOrPtrToIntOrPtr(llvm::Value *Val, + llvm::Type *Ty, + CodeGenFunction &CGF) { + if (Val->getType() == Ty) + return Val; + + if (isa<llvm::PointerType>(Val->getType())) { + // If this is Pointer->Pointer avoid conversion to and from int. + if (isa<llvm::PointerType>(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<llvm::PointerType>(DestIntTy)) + DestIntTy = CGF.IntPtrTy; + + if (Val->getType() != DestIntTy) + Val = CGF.Builder.CreateIntCast(Val, DestIntTy, false, "coerce.val.ii"); + + if (isa<llvm::PointerType>(Ty)) + Val = CGF.Builder.CreateIntToPtr(Val, Ty, "coerce.val.ip"); + return Val; +} + + + +/// CreateCoercedLoad - Create a load from \arg SrcPtr interpreted as +/// a pointer to an object of type \arg Ty. +/// +/// This safely handles the case when the src type is smaller than the +/// destination type; in this situation the values of bits which not +/// present in the src are undefined. +static llvm::Value *CreateCoercedLoad(llvm::Value *SrcPtr, + llvm::Type *Ty, + CodeGenFunction &CGF) { + llvm::Type *SrcTy = + cast<llvm::PointerType>(SrcPtr->getType())->getElementType(); + + // If SrcTy and Ty are the same, just do a load. + if (SrcTy == Ty) + return CGF.Builder.CreateLoad(SrcPtr); + + uint64_t DstSize = CGF.CGM.getTargetData().getTypeAllocSize(Ty); + + if (llvm::StructType *SrcSTy = dyn_cast<llvm::StructType>(SrcTy)) { + SrcPtr = EnterStructPointerForCoercedAccess(SrcPtr, SrcSTy, DstSize, CGF); + SrcTy = cast<llvm::PointerType>(SrcPtr->getType())->getElementType(); + } + + uint64_t SrcSize = CGF.CGM.getTargetData().getTypeAllocSize(SrcTy); + + // If the source and destination are integer or pointer types, just do an + // extension or truncation to the desired type. + if ((isa<llvm::IntegerType>(Ty) || isa<llvm::PointerType>(Ty)) && + (isa<llvm::IntegerType>(SrcTy) || isa<llvm::PointerType>(SrcTy))) { + llvm::LoadInst *Load = CGF.Builder.CreateLoad(SrcPtr); + return CoerceIntOrPtrToIntOrPtr(Load, Ty, CGF); + } + + // If load is legal, just bitcast the src pointer. + if (SrcSize >= DstSize) { + // Generally SrcSize is never greater than DstSize, since this means we are + // losing bits. However, this can happen in cases where the structure has + // additional padding, for example due to a user specified alignment. + // + // FIXME: Assert that we aren't truncating non-padding bits when have access + // to that information. + llvm::Value *Casted = + CGF.Builder.CreateBitCast(SrcPtr, llvm::PointerType::getUnqual(Ty)); + llvm::LoadInst *Load = CGF.Builder.CreateLoad(Casted); + // FIXME: Use better alignment / avoid requiring aligned load. + Load->setAlignment(1); + return Load; + } + + // Otherwise do coercion through memory. This is stupid, but + // simple. + llvm::Value *Tmp = CGF.CreateTempAlloca(Ty); + llvm::Value *Casted = + CGF.Builder.CreateBitCast(Tmp, llvm::PointerType::getUnqual(SrcTy)); + llvm::StoreInst *Store = + CGF.Builder.CreateStore(CGF.Builder.CreateLoad(SrcPtr), Casted); + // FIXME: Use better alignment / avoid requiring aligned store. + Store->setAlignment(1); + return CGF.Builder.CreateLoad(Tmp); +} + +// Function to store a first-class aggregate into memory. We prefer to +// store the elements rather than the aggregate to be more friendly to +// fast-isel. +// FIXME: Do we need to recurse here? +static void BuildAggStore(CodeGenFunction &CGF, llvm::Value *Val, + llvm::Value *DestPtr, bool DestIsVolatile, + bool LowAlignment) { + // Prefer scalar stores to first-class aggregate stores. + if (llvm::StructType *STy = + dyn_cast<llvm::StructType>(Val->getType())) { + for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { + llvm::Value *EltPtr = CGF.Builder.CreateConstGEP2_32(DestPtr, 0, i); + llvm::Value *Elt = CGF.Builder.CreateExtractValue(Val, i); + llvm::StoreInst *SI = CGF.Builder.CreateStore(Elt, EltPtr, + DestIsVolatile); + if (LowAlignment) + SI->setAlignment(1); + } + } else { + llvm::StoreInst *SI = CGF.Builder.CreateStore(Val, DestPtr, DestIsVolatile); + if (LowAlignment) + SI->setAlignment(1); + } +} + +/// CreateCoercedStore - Create a store to \arg DstPtr from \arg Src, +/// where the source and destination may have different types. +/// +/// This safely handles the case when the src type is larger than the +/// destination type; the upper bits of the src will be lost. +static void CreateCoercedStore(llvm::Value *Src, + llvm::Value *DstPtr, + bool DstIsVolatile, + CodeGenFunction &CGF) { + llvm::Type *SrcTy = Src->getType(); + llvm::Type *DstTy = + cast<llvm::PointerType>(DstPtr->getType())->getElementType(); + if (SrcTy == DstTy) { + CGF.Builder.CreateStore(Src, DstPtr, DstIsVolatile); + return; + } + + uint64_t SrcSize = CGF.CGM.getTargetData().getTypeAllocSize(SrcTy); + + if (llvm::StructType *DstSTy = dyn_cast<llvm::StructType>(DstTy)) { + DstPtr = EnterStructPointerForCoercedAccess(DstPtr, DstSTy, SrcSize, CGF); + DstTy = cast<llvm::PointerType>(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<llvm::IntegerType>(SrcTy) || isa<llvm::PointerType>(SrcTy)) && + (isa<llvm::IntegerType>(DstTy) || isa<llvm::PointerType>(DstTy))) { + Src = CoerceIntOrPtrToIntOrPtr(Src, DstTy, CGF); + CGF.Builder.CreateStore(Src, DstPtr, DstIsVolatile); + return; + } + + uint64_t DstSize = CGF.CGM.getTargetData().getTypeAllocSize(DstTy); + + // If store is legal, just bitcast the src pointer. + if (SrcSize <= DstSize) { + llvm::Value *Casted = + CGF.Builder.CreateBitCast(DstPtr, llvm::PointerType::getUnqual(SrcTy)); + // FIXME: Use better alignment / avoid requiring aligned store. + BuildAggStore(CGF, Src, Casted, DstIsVolatile, true); + } else { + // Otherwise do coercion through memory. This is stupid, but + // simple. + + // Generally SrcSize is never greater than DstSize, since this means we are + // losing bits. However, this can happen in cases where the structure has + // additional padding, for example due to a user specified alignment. + // + // FIXME: Assert that we aren't truncating non-padding bits when have access + // to that information. + llvm::Value *Tmp = CGF.CreateTempAlloca(SrcTy); + CGF.Builder.CreateStore(Src, Tmp); + llvm::Value *Casted = + CGF.Builder.CreateBitCast(Tmp, llvm::PointerType::getUnqual(DstTy)); + llvm::LoadInst *Load = CGF.Builder.CreateLoad(Casted); + // FIXME: Use better alignment / avoid requiring aligned load. + Load->setAlignment(1); + CGF.Builder.CreateStore(Load, DstPtr, DstIsVolatile); + } +} + +/***/ + +bool CodeGenModule::ReturnTypeUsesSRet(const CGFunctionInfo &FI) { + return FI.getReturnInfo().isIndirect(); +} + +bool CodeGenModule::ReturnTypeUsesFPRet(QualType ResultType) { + if (const BuiltinType *BT = ResultType->getAs<BuiltinType>()) { + switch (BT->getKind()) { + default: + return false; + case BuiltinType::Float: + return getContext().getTargetInfo().useObjCFPRetForRealType(TargetInfo::Float); + case BuiltinType::Double: + return getContext().getTargetInfo().useObjCFPRetForRealType(TargetInfo::Double); + case BuiltinType::LongDouble: + return getContext().getTargetInfo().useObjCFPRetForRealType( + TargetInfo::LongDouble); + } + } + + return false; +} + +bool CodeGenModule::ReturnTypeUsesFP2Ret(QualType ResultType) { + if (const ComplexType *CT = ResultType->getAs<ComplexType>()) { + if (const BuiltinType *BT = CT->getElementType()->getAs<BuiltinType>()) { + if (BT->getKind() == BuiltinType::LongDouble) + return getContext().getTargetInfo().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); (void)Inserted; + assert(Inserted && "Recursively being processed?"); + + SmallVector<llvm::Type*, 8> argTypes; + llvm::Type *resultType = 0; + + const ABIArgInfo &retAI = FI.getReturnInfo(); + switch (retAI.getKind()) { + case ABIArgInfo::Expand: + llvm_unreachable("Invalid ABI kind for return argument"); + + case ABIArgInfo::Extend: + case ABIArgInfo::Direct: + resultType = retAI.getCoerceToType(); + break; + + case ABIArgInfo::Indirect: { + assert(!retAI.getIndirectAlign() && "Align unused on indirect return."); + resultType = llvm::Type::getVoidTy(getLLVMContext()); + + QualType ret = FI.getReturnType(); + llvm::Type *ty = ConvertType(ret); + unsigned addressSpace = Context.getTargetAddressSpace(ret); + argTypes.push_back(llvm::PointerType::get(ty, addressSpace)); + break; + } + + case ABIArgInfo::Ignore: + resultType = llvm::Type::getVoidTy(getLLVMContext()); + break; + } + + for (CGFunctionInfo::const_arg_iterator it = FI.arg_begin(), + ie = FI.arg_end(); it != ie; ++it) { + const ABIArgInfo &argAI = it->info; + + switch (argAI.getKind()) { + case ABIArgInfo::Ignore: + break; + + case ABIArgInfo::Indirect: { + // indirect arguments are always on the stack, which is addr space #0. + llvm::Type *LTy = ConvertTypeForMem(it->type); + argTypes.push_back(LTy->getPointerTo()); + break; + } + + case ABIArgInfo::Extend: + case ABIArgInfo::Direct: { + // Insert a padding type to ensure proper alignment. + if (llvm::Type *PaddingType = argAI.getPaddingType()) + argTypes.push_back(PaddingType); + // If the coerce-to type is a first class aggregate, flatten it. Either + // way is semantically identical, but fast-isel and the optimizer + // generally likes scalar values better than FCAs. + llvm::Type *argType = argAI.getCoerceToType(); + if (llvm::StructType *st = dyn_cast<llvm::StructType>(argType)) { + for (unsigned i = 0, e = st->getNumElements(); i != e; ++i) + argTypes.push_back(st->getElementType(i)); + } else { + argTypes.push_back(argType); + } + break; + } + + case ABIArgInfo::Expand: + GetExpandedTypes(it->type, argTypes); + break; + } + } + + bool Erased = FunctionsBeingProcessed.erase(&FI); (void)Erased; + assert(Erased && "Not in set?"); + + return llvm::FunctionType::get(resultType, argTypes, FI.isVariadic()); +} + +llvm::Type *CodeGenTypes::GetFunctionTypeForVTable(GlobalDecl GD) { + const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); + const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>(); + + if (!isFuncTypeConvertible(FPT)) + return llvm::StructType::get(getLLVMContext()); + + const CGFunctionInfo *Info; + if (isa<CXXDestructorDecl>(MD)) + Info = &arrangeCXXDestructor(cast<CXXDestructorDecl>(MD), GD.getDtorType()); + else + Info = &arrangeCXXMethodDeclaration(MD); + return GetFunctionType(*Info); +} + +void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI, + const Decl *TargetDecl, + AttributeListType &PAL, + unsigned &CallingConv) { + llvm::Attributes FuncAttrs; + llvm::Attributes RetAttrs; + + CallingConv = FI.getEffectiveCallingConvention(); + + if (FI.isNoReturn()) + FuncAttrs |= llvm::Attribute::NoReturn; + + // FIXME: handle sseregparm someday... + if (TargetDecl) { + if (TargetDecl->hasAttr<ReturnsTwiceAttr>()) + FuncAttrs |= llvm::Attribute::ReturnsTwice; + if (TargetDecl->hasAttr<NoThrowAttr>()) + FuncAttrs |= llvm::Attribute::NoUnwind; + else if (const FunctionDecl *Fn = dyn_cast<FunctionDecl>(TargetDecl)) { + const FunctionProtoType *FPT = Fn->getType()->getAs<FunctionProtoType>(); + if (FPT && FPT->isNothrow(getContext())) + FuncAttrs |= llvm::Attribute::NoUnwind; + } + + if (TargetDecl->hasAttr<NoReturnAttr>()) + FuncAttrs |= llvm::Attribute::NoReturn; + + if (TargetDecl->hasAttr<ReturnsTwiceAttr>()) + FuncAttrs |= llvm::Attribute::ReturnsTwice; + + // 'const' and 'pure' attribute functions are also nounwind. + if (TargetDecl->hasAttr<ConstAttr>()) { + FuncAttrs |= llvm::Attribute::ReadNone; + FuncAttrs |= llvm::Attribute::NoUnwind; + } else if (TargetDecl->hasAttr<PureAttr>()) { + FuncAttrs |= llvm::Attribute::ReadOnly; + FuncAttrs |= llvm::Attribute::NoUnwind; + } + if (TargetDecl->hasAttr<MallocAttr>()) + RetAttrs |= llvm::Attribute::NoAlias; + } + + if (CodeGenOpts.OptimizeSize) + FuncAttrs |= llvm::Attribute::OptimizeForSize; + if (CodeGenOpts.DisableRedZone) + FuncAttrs |= llvm::Attribute::NoRedZone; + if (CodeGenOpts.NoImplicitFloat) + FuncAttrs |= llvm::Attribute::NoImplicitFloat; + + QualType RetTy = FI.getReturnType(); + unsigned Index = 1; + const ABIArgInfo &RetAI = FI.getReturnInfo(); + switch (RetAI.getKind()) { + case ABIArgInfo::Extend: + if (RetTy->hasSignedIntegerRepresentation()) + RetAttrs |= llvm::Attribute::SExt; + else if (RetTy->hasUnsignedIntegerRepresentation()) + RetAttrs |= llvm::Attribute::ZExt; + break; + case ABIArgInfo::Direct: + case ABIArgInfo::Ignore: + break; + + case ABIArgInfo::Indirect: + PAL.push_back(llvm::AttributeWithIndex::get(Index, + llvm::Attribute::StructRet)); + ++Index; + // sret disables readnone and readonly + FuncAttrs &= ~(llvm::Attribute::ReadOnly | + llvm::Attribute::ReadNone); + break; + + case ABIArgInfo::Expand: + llvm_unreachable("Invalid ABI kind for return argument"); + } + + if (RetAttrs) + PAL.push_back(llvm::AttributeWithIndex::get(0, RetAttrs)); + + // FIXME: RegParm should be reduced in case of global register variable. + signed RegParm; + if (FI.getHasRegParm()) + RegParm = FI.getRegParm(); + else + RegParm = CodeGenOpts.NumRegisterParameters; + + unsigned PointerWidth = getContext().getTargetInfo().getPointerWidth(0); + for (CGFunctionInfo::const_arg_iterator it = FI.arg_begin(), + ie = FI.arg_end(); it != ie; ++it) { + QualType ParamType = it->type; + const ABIArgInfo &AI = it->info; + llvm::Attributes Attrs; + + // '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 |= llvm::Attribute::SExt; + else if (ParamType->isUnsignedIntegerOrEnumerationType()) + Attrs |= llvm::Attribute::ZExt; + // FALL THROUGH + case ABIArgInfo::Direct: + if (RegParm > 0 && + (ParamType->isIntegerType() || ParamType->isPointerType() || + ParamType->isReferenceType())) { + RegParm -= + (Context.getTypeSize(ParamType) + PointerWidth - 1) / PointerWidth; + if (RegParm >= 0) + Attrs |= llvm::Attribute::InReg; + } + // FIXME: handle sseregparm someday... + + // Increment Index if there is padding. + Index += (AI.getPaddingType() != 0); + + if (llvm::StructType *STy = + dyn_cast<llvm::StructType>(AI.getCoerceToType())) + Index += STy->getNumElements()-1; // 1 will be added below. + break; + + case ABIArgInfo::Indirect: + if (AI.getIndirectByVal()) + Attrs |= llvm::Attribute::ByVal; + + Attrs |= + llvm::Attribute::constructAlignmentFromInt(AI.getIndirectAlign()); + // byval disables readnone and readonly. + FuncAttrs &= ~(llvm::Attribute::ReadOnly | + llvm::Attribute::ReadNone); + break; + + case ABIArgInfo::Ignore: + // Skip increment, no matching LLVM parameter. + continue; + + case ABIArgInfo::Expand: { + SmallVector<llvm::Type*, 8> types; + // FIXME: This is rather inefficient. Do we ever actually need to do + // anything here? The result should be just reconstructed on the other + // side, so extension should be a non-issue. + getTypes().GetExpandedTypes(ParamType, types); + Index += types.size(); + continue; + } + } + + if (Attrs) + PAL.push_back(llvm::AttributeWithIndex::get(Index, Attrs)); + ++Index; + } + if (FuncAttrs) + PAL.push_back(llvm::AttributeWithIndex::get(~0, FuncAttrs)); +} + +/// An argument came in as a promoted argument; demote it back to its +/// declared type. +static llvm::Value *emitArgumentDemotion(CodeGenFunction &CGF, + const VarDecl *var, + llvm::Value *value) { + 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<llvm::IntegerType>(varType)) + return CGF.Builder.CreateTrunc(value, varType, "arg.unpromote"); + + return CGF.Builder.CreateFPCast(value, varType, "arg.unpromote"); +} + +void CodeGenFunction::EmitFunctionProlog(const CGFunctionInfo &FI, + llvm::Function *Fn, + const FunctionArgList &Args) { + // If this is an implicit-return-zero function, go ahead and + // initialize the return value. TODO: it might be nice to have + // a more general mechanism for this that didn't require synthesized + // return statements. + if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(CurFuncDecl)) { + if (FD->hasImplicitReturnZero()) { + QualType RetTy = FD->getResultType().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. + + // Emit allocs for param decls. Give the LLVM Argument nodes names. + llvm::Function::arg_iterator AI = Fn->arg_begin(); + + // Name the struct return argument. + if (CGM.ReturnTypeUsesSRet(FI)) { + AI->setName("agg.result"); + AI->addAttr(llvm::Attribute::NoAlias); + ++AI; + } + + assert(FI.arg_size() == Args.size() && + "Mismatch between function signature & arguments."); + unsigned ArgNo = 1; + CGFunctionInfo::const_arg_iterator info_it = FI.arg_begin(); + for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end(); + i != e; ++i, ++info_it, ++ArgNo) { + const VarDecl *Arg = *i; + QualType Ty = info_it->type; + const ABIArgInfo &ArgI = info_it->info; + + bool isPromoted = + isa<ParmVarDecl>(Arg) && cast<ParmVarDecl>(Arg)->isKNRPromoted(); + + switch (ArgI.getKind()) { + case ABIArgInfo::Indirect: { + llvm::Value *V = AI; + + if (hasAggregateLLVMType(Ty)) { + // Aggregates and complex variables are accessed by reference. All we + // need to do is realign the value, if requested + if (ArgI.getIndirectRealign()) { + llvm::Value *AlignedTemp = CreateMemTemp(Ty, "coerce"); + + // Copy from the incoming argument pointer to the temporary with the + // appropriate alignment. + // + // FIXME: We should have a common utility for generating an aggregate + // copy. + llvm::Type *I8PtrTy = Builder.getInt8PtrTy(); + CharUnits Size = getContext().getTypeSizeInChars(Ty); + llvm::Value *Dst = Builder.CreateBitCast(AlignedTemp, I8PtrTy); + llvm::Value *Src = Builder.CreateBitCast(V, I8PtrTy); + Builder.CreateMemCpy(Dst, + Src, + llvm::ConstantInt::get(IntPtrTy, + Size.getQuantity()), + ArgI.getIndirectAlign(), + false); + V = AlignedTemp; + } + } else { + // Load scalar value from indirect argument. + CharUnits Alignment = getContext().getTypeAlignInChars(Ty); + V = EmitLoadOfScalar(V, false, Alignment.getQuantity(), Ty); + + if (isPromoted) + V = emitArgumentDemotion(*this, Arg, V); + } + EmitParmDecl(*Arg, V, ArgNo); + break; + } + + case ABIArgInfo::Extend: + case ABIArgInfo::Direct: { + // Skip the dummy padding argument. + if (ArgI.getPaddingType()) + ++AI; + + // If we have the trivial case, handle it with no muss and fuss. + if (!isa<llvm::StructType>(ArgI.getCoerceToType()) && + ArgI.getCoerceToType() == ConvertType(Ty) && + ArgI.getDirectOffset() == 0) { + assert(AI != Fn->arg_end() && "Argument mismatch!"); + llvm::Value *V = AI; + + if (Arg->getType().isRestrictQualified()) + AI->addAttr(llvm::Attribute::NoAlias); + + // 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); + + EmitParmDecl(*Arg, V, ArgNo); + 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.getTargetData().getABITypeAlignment(ArgI.getCoerceToType()); + AlignmentToUse = std::max(AlignmentToUse, + (unsigned)getContext().getDeclAlign(Arg).getQuantity()); + + Alloca->setAlignment(AlignmentToUse); + llvm::Value *V = Alloca; + llvm::Value *Ptr = V; // Pointer to store into. + + // If the value is offset in memory, apply the offset now. + if (unsigned Offs = ArgI.getDirectOffset()) { + Ptr = Builder.CreateBitCast(Ptr, Builder.getInt8PtrTy()); + Ptr = Builder.CreateConstGEP1_32(Ptr, Offs); + Ptr = Builder.CreateBitCast(Ptr, + llvm::PointerType::getUnqual(ArgI.getCoerceToType())); + } + + // If the coerce-to type is a first class aggregate, we flatten it and + // pass the elements. Either way is semantically identical, but fast-isel + // and the optimizer generally likes scalar values better than FCAs. + llvm::StructType *STy = dyn_cast<llvm::StructType>(ArgI.getCoerceToType()); + if (STy && STy->getNumElements() > 1) { + uint64_t SrcSize = CGM.getTargetData().getTypeAllocSize(STy); + llvm::Type *DstTy = + cast<llvm::PointerType>(Ptr->getType())->getElementType(); + uint64_t DstSize = CGM.getTargetData().getTypeAllocSize(DstTy); + + if (SrcSize <= DstSize) { + Ptr = Builder.CreateBitCast(Ptr, llvm::PointerType::getUnqual(STy)); + + for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { + assert(AI != Fn->arg_end() && "Argument mismatch!"); + AI->setName(Arg->getName() + ".coerce" + Twine(i)); + llvm::Value *EltPtr = Builder.CreateConstGEP2_32(Ptr, 0, i); + Builder.CreateStore(AI++, EltPtr); + } + } else { + llvm::AllocaInst *TempAlloca = + CreateTempAlloca(ArgI.getCoerceToType(), "coerce"); + TempAlloca->setAlignment(AlignmentToUse); + llvm::Value *TempV = TempAlloca; + + for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { + assert(AI != Fn->arg_end() && "Argument mismatch!"); + AI->setName(Arg->getName() + ".coerce" + Twine(i)); + llvm::Value *EltPtr = Builder.CreateConstGEP2_32(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(AI != Fn->arg_end() && "Argument mismatch!"); + AI->setName(Arg->getName() + ".coerce"); + CreateCoercedStore(AI++, Ptr, /*DestIsVolatile=*/false, *this); + } + + + // Match to what EmitParmDecl is expecting for this type. + if (!CodeGenFunction::hasAggregateLLVMType(Ty)) { + V = EmitLoadOfScalar(V, false, AlignmentToUse, Ty); + if (isPromoted) + V = emitArgumentDemotion(*this, Arg, V); + } + EmitParmDecl(*Arg, V, ArgNo); + continue; // Skip ++AI increment, already done. + } + + case ABIArgInfo::Expand: { + // If this structure was expanded into multiple arguments then + // we need to create a temporary and reconstruct it from the + // arguments. + llvm::AllocaInst *Alloca = CreateMemTemp(Ty); + CharUnits Align = getContext().getDeclAlign(Arg); + Alloca->setAlignment(Align.getQuantity()); + LValue LV = MakeAddrLValue(Alloca, Ty, Align); + llvm::Function::arg_iterator End = ExpandTypeFromArgs(Ty, LV, AI); + EmitParmDecl(*Arg, Alloca, ArgNo); + + // Name the arguments used in expansion and increment AI. + unsigned Index = 0; + for (; AI != End; ++AI, ++Index) + AI->setName(Arg->getName() + "." + Twine(Index)); + continue; + } + + case ABIArgInfo::Ignore: + // Initialize the local variable appropriately. + if (hasAggregateLLVMType(Ty)) + EmitParmDecl(*Arg, CreateMemTemp(Ty), ArgNo); + else + EmitParmDecl(*Arg, llvm::UndefValue::get(ConvertType(Arg->getType())), + ArgNo); + + // Skip increment, no matching LLVM parameter. + continue; + } + + ++AI; + } + assert(AI == Fn->arg_end() && "Argument mismatch!"); +} + +static void eraseUnusedBitCasts(llvm::Instruction *insn) { + while (insn->use_empty()) { + llvm::BitCastInst *bitcast = dyn_cast<llvm::BitCastInst>(insn); + if (!bitcast) return; + + // This is "safe" because we would have used a ConstantExpr otherwise. + insn = cast<llvm::Instruction>(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 0; + if (&BB->back() != result) return 0; + + llvm::Type *resultType = result->getType(); + + // result is in a BasicBlock and is therefore an Instruction. + llvm::Instruction *generator = cast<llvm::Instruction>(result); + + SmallVector<llvm::Instruction*,4> insnsToKill; + + // Look for: + // %generator = bitcast %type1* %generator2 to %type2* + while (llvm::BitCastInst *bitcast = dyn_cast<llvm::BitCastInst>(generator)) { + // We would have emitted this as a constant if the operand weren't + // an Instruction. + generator = cast<llvm::Instruction>(bitcast->getOperand(0)); + + // Require the generator to be immediately followed by the cast. + if (generator->getNextNode() != bitcast) + return 0; + + insnsToKill.push_back(bitcast); + } + + // Look for: + // %generator = call i8* @objc_retain(i8* %originalResult) + // or + // %generator = call i8* @objc_retainAutoreleasedReturnValue(i8* %originalResult) + llvm::CallInst *call = dyn_cast<llvm::CallInst>(generator); + if (!call) return 0; + + bool doRetainAutorelease; + + if (call->getCalledValue() == CGF.CGM.getARCEntrypoints().objc_retain) { + doRetainAutorelease = true; + } else if (call->getCalledValue() == CGF.CGM.getARCEntrypoints() + .objc_retainAutoreleasedReturnValue) { + doRetainAutorelease = false; + + // Look for an inline asm immediately preceding the call and kill it, too. + llvm::Instruction *prev = call->getPrevNode(); + if (llvm::CallInst *asmCall = dyn_cast_or_null<llvm::CallInst>(prev)) + if (asmCall->getCalledValue() + == CGF.CGM.getARCEntrypoints().retainAutoreleasedReturnValueMarker) + insnsToKill.push_back(prev); + } else { + return 0; + } + + result = call->getArgOperand(0); + insnsToKill.push_back(call); + + // Keep killing bitcasts, for sanity. Note that we no longer care + // about precise ordering as long as there's exactly one use. + while (llvm::BitCastInst *bitcast = dyn_cast<llvm::BitCastInst>(result)) { + if (!bitcast->hasOneUse()) break; + insnsToKill.push_back(bitcast); + result = bitcast->getOperand(0); + } + + // Delete all the unnecessary instructions, from latest to earliest. + for (SmallVectorImpl<llvm::Instruction*>::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<ObjCMethodDecl>(CGF.CurCodeDecl); + if (!method) return 0; + const VarDecl *self = method->getSelfDecl(); + if (!self->getType().isConstQualified()) return 0; + + // Look for a retain call. + llvm::CallInst *retainCall = + dyn_cast<llvm::CallInst>(result->stripPointerCasts()); + if (!retainCall || + retainCall->getCalledValue() != CGF.CGM.getARCEntrypoints().objc_retain) + return 0; + + // Look for an ordinary load of 'self'. + llvm::Value *retainedValue = retainCall->getArgOperand(0); + llvm::LoadInst *load = + dyn_cast<llvm::LoadInst>(retainedValue->stripPointerCasts()); + if (!load || load->isAtomic() || load->isVolatile() || + load->getPointerOperand() != CGF.GetAddrOfLocalVar(self)) + return 0; + + // 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<llvm::Instruction>(result)); + assert(retainCall->use_empty()); + retainCall->eraseFromParent(); + eraseUnusedBitCasts(cast<llvm::Instruction>(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 0; + llvm::StoreInst *store = dyn_cast<llvm::StoreInst>(&IP->back()); + if (!store) return 0; + if (store->getPointerOperand() != CGF.ReturnValue) return 0; + assert(!store->isAtomic() && !store->isVolatile()); // see below + return store; + } + + llvm::StoreInst *store = + dyn_cast<llvm::StoreInst>(CGF.ReturnValue->use_back()); + if (!store) return 0; + + // 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 0; + } + + // Okay, the store's basic block dominates the insertion point; we + // can do our thing. + return store; +} + +void CodeGenFunction::EmitFunctionEpilog(const CGFunctionInfo &FI) { + // Functions with no result always return void. + if (ReturnValue == 0) { + Builder.CreateRetVoid(); + return; + } + + llvm::DebugLoc RetDbgLoc; + llvm::Value *RV = 0; + QualType RetTy = FI.getReturnType(); + const ABIArgInfo &RetAI = FI.getReturnInfo(); + + switch (RetAI.getKind()) { + case ABIArgInfo::Indirect: { + unsigned Alignment = getContext().getTypeAlignInChars(RetTy).getQuantity(); + if (RetTy->isAnyComplexType()) { + ComplexPairTy RT = LoadComplexFromAddr(ReturnValue, false); + StoreComplexToAddr(RT, CurFn->arg_begin(), false); + } else if (CodeGenFunction::hasAggregateLLVMType(RetTy)) { + // Do nothing; aggregrates get evaluated directly into the destination. + } else { + EmitStoreOfScalar(Builder.CreateLoad(ReturnValue), CurFn->arg_begin(), + false, Alignment, RetTy); + } + break; + } + + case ABIArgInfo::Extend: + case ABIArgInfo::Direct: + if (RetAI.getCoerceToType() == ConvertType(RetTy) && + RetAI.getDirectOffset() == 0) { + // The internal return value temp always will have pointer-to-return-type + // type, just do a load. + + // If 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)) { + // Get the stored value and nuke the now-dead store. + RetDbgLoc = SI->getDebugLoc(); + RV = SI->getValueOperand(); + SI->eraseFromParent(); + + // If that was the only use of the return value, nuke it as well now. + if (ReturnValue->use_empty() && isa<llvm::AllocaInst>(ReturnValue)) { + cast<llvm::AllocaInst>(ReturnValue)->eraseFromParent(); + ReturnValue = 0; + } + + // Otherwise, we have to do a simple load. + } else { + RV = Builder.CreateLoad(ReturnValue); + } + } else { + llvm::Value *V = ReturnValue; + // If the value is offset in memory, apply the offset now. + if (unsigned Offs = RetAI.getDirectOffset()) { + V = Builder.CreateBitCast(V, Builder.getInt8PtrTy()); + V = Builder.CreateConstGEP1_32(V, Offs); + V = Builder.CreateBitCast(V, + llvm::PointerType::getUnqual(RetAI.getCoerceToType())); + } + + RV = CreateCoercedLoad(V, RetAI.getCoerceToType(), *this); + } + + // In ARC, end functions that return a retainable type with a call + // to objc_autoreleaseReturnValue. + if (AutoreleaseResult) { + assert(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 = RV ? Builder.CreateRet(RV) : Builder.CreateRetVoid(); + if (!RetDbgLoc.isUnknown()) + Ret->setDebugLoc(RetDbgLoc); +} + +void CodeGenFunction::EmitDelegateCallArg(CallArgList &args, + const VarDecl *param) { + // StartFunction converted the ABI-lowered parameter(s) into a + // local alloca. We need to turn that into an r-value suitable + // for EmitCall. + llvm::Value *local = GetAddrOfLocalVar(param); + + QualType type = param->getType(); + + // For the most part, we just need to load the alloca, except: + // 1) aggregate r-values are actually pointers to temporaries, and + // 2) references to aggregates are pointers directly to the aggregate. + // I don't know why references to non-aggregates are different here. + if (const ReferenceType *ref = type->getAs<ReferenceType>()) { + if (hasAggregateLLVMType(ref->getPointeeType())) + return args.add(RValue::getAggregate(local), type); + + // Locals which are references to scalars are represented + // with allocas holding the pointer. + return args.add(RValue::get(Builder.CreateLoad(local)), type); + } + + if (type->isAnyComplexType()) { + ComplexPairTy complex = LoadComplexFromAddr(local, /*volatile*/ false); + return args.add(RValue::getComplex(complex), type); + } + + if (hasAggregateLLVMType(type)) + return args.add(RValue::getAggregate(local), type); + + unsigned alignment = getContext().getDeclAlign(param).getQuantity(); + llvm::Value *value = EmitLoadOfScalar(local, false, alignment, type); + return args.add(RValue::get(value), type); +} + +static bool isProvablyNull(llvm::Value *addr) { + return isa<llvm::ConstantPointerNull>(addr); +} + +static bool isProvablyNonNull(llvm::Value *addr) { + return isa<llvm::AllocaInst>(addr); +} + +/// Emit the actual writing-back of a writeback. +static void emitWriteback(CodeGenFunction &CGF, + const CallArgList::Writeback &writeback) { + llvm::Value *srcAddr = writeback.Address; + assert(!isProvablyNull(srcAddr) && + "shouldn't have writeback for provably null argument"); + + llvm::BasicBlock *contBB = 0; + + // If the argument wasn't provably non-null, we need to null check + // before doing the store. + bool provablyNonNull = isProvablyNonNull(srcAddr); + if (!provablyNonNull) { + llvm::BasicBlock *writebackBB = CGF.createBasicBlock("icr.writeback"); + contBB = CGF.createBasicBlock("icr.done"); + + llvm::Value *isNull = CGF.Builder.CreateIsNull(srcAddr, "icr.isnull"); + CGF.Builder.CreateCondBr(isNull, contBB, writebackBB); + CGF.EmitBlock(writebackBB); + } + + // Load the value to writeback. + llvm::Value *value = CGF.Builder.CreateLoad(writeback.Temporary); + + // Cast it back, in case we're writing an id to a Foo* or something. + value = CGF.Builder.CreateBitCast(value, + cast<llvm::PointerType>(srcAddr->getType())->getElementType(), + "icr.writeback-cast"); + + // Perform the writeback. + QualType srcAddrType = writeback.AddressType; + CGF.EmitStoreThroughLValue(RValue::get(value), + CGF.MakeAddrLValue(srcAddr, srcAddrType)); + + // Jump to the continuation block. + if (!provablyNonNull) + CGF.EmitBlock(contBB); +} + +static void emitWritebacks(CodeGenFunction &CGF, + const CallArgList &args) { + for (CallArgList::writeback_iterator + i = args.writeback_begin(), e = args.writeback_end(); i != e; ++i) + emitWriteback(CGF, *i); +} + +/// Emit an argument that's being passed call-by-writeback. That is, +/// we are passing the address of +static void emitWritebackArg(CodeGenFunction &CGF, CallArgList &args, + const ObjCIndirectCopyRestoreExpr *CRE) { + llvm::Value *srcAddr = CGF.EmitScalarExpr(CRE->getSubExpr()); + + // The dest and src types don't necessarily match in LLVM terms + // because of the crazy ObjC compatibility rules. + + llvm::PointerType *destType = + cast<llvm::PointerType>(CGF.ConvertType(CRE->getType())); + + // If the address is a constant null, just pass the appropriate null. + if (isProvablyNull(srcAddr)) { + args.add(RValue::get(llvm::ConstantPointerNull::get(destType)), + CRE->getType()); + return; + } + + QualType srcAddrType = + CRE->getSubExpr()->getType()->castAs<PointerType>()->getPointeeType(); + + // Create the temporary. + llvm::Value *temp = CGF.CreateTempAlloca(destType->getElementType(), + "icr.temp"); + + // Zero-initialize it if we're not doing a copy-initialization. + bool shouldCopy = CRE->shouldCopy(); + if (!shouldCopy) { + llvm::Value *null = + llvm::ConstantPointerNull::get( + cast<llvm::PointerType>(destType->getElementType())); + CGF.Builder.CreateStore(null, temp); + } + + llvm::BasicBlock *contBB = 0; + + // If the address is *not* known to be non-null, we need to switch. + llvm::Value *finalArgument; + + bool provablyNonNull = isProvablyNonNull(srcAddr); + if (provablyNonNull) { + finalArgument = temp; + } else { + llvm::Value *isNull = CGF.Builder.CreateIsNull(srcAddr, "icr.isnull"); + + finalArgument = CGF.Builder.CreateSelect(isNull, + llvm::ConstantPointerNull::get(destType), + temp, "icr.argument"); + + // If we need to copy, then the load has to be conditional, which + // means we need control flow. + if (shouldCopy) { + contBB = CGF.createBasicBlock("icr.cont"); + llvm::BasicBlock *copyBB = CGF.createBasicBlock("icr.copy"); + CGF.Builder.CreateCondBr(isNull, contBB, copyBB); + CGF.EmitBlock(copyBB); + } + } + + // Perform a copy if necessary. + if (shouldCopy) { + LValue srcLV = CGF.MakeAddrLValue(srcAddr, srcAddrType); + RValue srcRV = CGF.EmitLoadOfLValue(srcLV); + assert(srcRV.isScalar()); + + llvm::Value *src = srcRV.getScalarVal(); + src = CGF.Builder.CreateBitCast(src, destType->getElementType(), + "icr.cast"); + + // Use an ordinary store, not a store-to-lvalue. + CGF.Builder.CreateStore(src, temp); + } + + // Finish the control flow if we needed it. + if (shouldCopy && !provablyNonNull) + CGF.EmitBlock(contBB); + + args.addWriteback(srcAddr, srcAddrType, temp); + args.add(RValue::get(finalArgument), CRE->getType()); +} + +void CodeGenFunction::EmitCallArg(CallArgList &args, const Expr *E, + QualType type) { + if (const ObjCIndirectCopyRestoreExpr *CRE + = dyn_cast<ObjCIndirectCopyRestoreExpr>(E)) { + assert(getContext().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, /*InitializedDecl=*/0), + type); + } + + if (hasAggregateLLVMType(type) && !E->getType()->isAnyComplexType() && + isa<ImplicitCastExpr>(E) && + cast<CastExpr>(E)->getCastKind() == CK_LValueToRValue) { + LValue L = EmitLValue(cast<CastExpr>(E)->getSubExpr()); + assert(L.isSimple()); + args.add(L.asAggregateRValue(), type, /*NeedsCopy*/true); + return; + } + + args.add(EmitAnyExprToTemp(E), type); +} + +// 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 or invoke instruction to the given function, depending +/// on the current state of the EH stack. +llvm::CallSite +CodeGenFunction::EmitCallOrInvoke(llvm::Value *Callee, + ArrayRef<llvm::Value *> 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 Inst; +} + +llvm::CallSite +CodeGenFunction::EmitCallOrInvoke(llvm::Value *Callee, + const Twine &Name) { + return EmitCallOrInvoke(Callee, ArrayRef<llvm::Value *>(), Name); +} + +static void checkArgMatches(llvm::Value *Elt, unsigned &ArgNo, + llvm::FunctionType *FTy) { + if (ArgNo < FTy->getNumParams()) + assert(Elt->getType() == FTy->getParamType(ArgNo)); + else + assert(FTy->isVarArg()); + ++ArgNo; +} + +void CodeGenFunction::ExpandTypeToArgs(QualType Ty, RValue RV, + SmallVector<llvm::Value*,16> &Args, + llvm::FunctionType *IRFuncTy) { + if (const ConstantArrayType *AT = getContext().getAsConstantArrayType(Ty)) { + unsigned NumElts = AT->getSize().getZExtValue(); + QualType EltTy = AT->getElementType(); + llvm::Value *Addr = RV.getAggregateAddr(); + for (unsigned Elt = 0; Elt < NumElts; ++Elt) { + llvm::Value *EltAddr = Builder.CreateConstGEP2_32(Addr, 0, Elt); + LValue LV = MakeAddrLValue(EltAddr, EltTy); + RValue EltRV; + if (EltTy->isAnyComplexType()) + // FIXME: Volatile? + EltRV = RValue::getComplex(LoadComplexFromAddr(LV.getAddress(), false)); + else if (CodeGenFunction::hasAggregateLLVMType(EltTy)) + EltRV = LV.asAggregateRValue(); + else + EltRV = EmitLoadOfLValue(LV); + ExpandTypeToArgs(EltTy, EltRV, Args, IRFuncTy); + } + } else if (const RecordType *RT = Ty->getAs<RecordType>()) { + RecordDecl *RD = RT->getDecl(); + assert(RV.isAggregate() && "Unexpected rvalue during struct expansion"); + LValue LV = MakeAddrLValue(RV.getAggregateAddr(), Ty); + + if (RD->isUnion()) { + const FieldDecl *LargestFD = 0; + CharUnits UnionSize = CharUnits::Zero(); + + for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); + i != e; ++i) { + const FieldDecl *FD = *i; + assert(!FD->isBitField() && + "Cannot expand structure with bit-field members."); + CharUnits FieldSize = getContext().getTypeSizeInChars(FD->getType()); + if (UnionSize < FieldSize) { + UnionSize = FieldSize; + LargestFD = FD; + } + } + if (LargestFD) { + RValue FldRV = EmitRValueForField(LV, LargestFD); + ExpandTypeToArgs(LargestFD->getType(), FldRV, Args, IRFuncTy); + } + } else { + for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); + i != e; ++i) { + FieldDecl *FD = *i; + + RValue FldRV = EmitRValueForField(LV, FD); + ExpandTypeToArgs(FD->getType(), FldRV, Args, IRFuncTy); + } + } + } else if (Ty->isAnyComplexType()) { + ComplexPairTy CV = RV.getComplexVal(); + Args.push_back(CV.first); + Args.push_back(CV.second); + } else { + assert(RV.isScalar() && + "Unexpected non-scalar rvalue during struct expansion."); + + // Insert a bitcast as needed. + llvm::Value *V = RV.getScalarVal(); + if (Args.size() < IRFuncTy->getNumParams() && + V->getType() != IRFuncTy->getParamType(Args.size())) + V = Builder.CreateBitCast(V, IRFuncTy->getParamType(Args.size())); + + Args.push_back(V); + } +} + + +RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo, + llvm::Value *Callee, + ReturnValueSlot ReturnValue, + const CallArgList &CallArgs, + const Decl *TargetDecl, + llvm::Instruction **callOrInvoke) { + // FIXME: We no longer need the types from CallArgs; lift up and simplify. + SmallVector<llvm::Value*, 16> Args; + + // Handle struct-return functions by passing a pointer to the + // location that we would like to return into. + QualType RetTy = CallInfo.getReturnType(); + const ABIArgInfo &RetAI = CallInfo.getReturnInfo(); + + // IRArgNo - Keep track of the argument number in the callee we're looking at. + unsigned IRArgNo = 0; + llvm::FunctionType *IRFuncTy = + cast<llvm::FunctionType>( + cast<llvm::PointerType>(Callee->getType())->getElementType()); + + // If the call returns a temporary with struct return, create a temporary + // alloca to hold the result, unless one is given to us. + if (CGM.ReturnTypeUsesSRet(CallInfo)) { + llvm::Value *Value = ReturnValue.getValue(); + if (!Value) + Value = CreateMemTemp(RetTy); + Args.push_back(Value); + checkArgMatches(Value, IRArgNo, IRFuncTy); + } + + assert(CallInfo.arg_size() == CallArgs.size() && + "Mismatch between function signature & arguments."); + CGFunctionInfo::const_arg_iterator info_it = CallInfo.arg_begin(); + for (CallArgList::const_iterator I = CallArgs.begin(), E = CallArgs.end(); + I != E; ++I, ++info_it) { + const ABIArgInfo &ArgInfo = info_it->info; + RValue RV = I->RV; + + unsigned TypeAlign = + getContext().getTypeAlignInChars(I->Ty).getQuantity(); + switch (ArgInfo.getKind()) { + case ABIArgInfo::Indirect: { + if (RV.isScalar() || RV.isComplex()) { + // Make a temporary alloca to pass the argument. + llvm::AllocaInst *AI = CreateMemTemp(I->Ty); + if (ArgInfo.getIndirectAlign() > AI->getAlignment()) + AI->setAlignment(ArgInfo.getIndirectAlign()); + Args.push_back(AI); + + if (RV.isScalar()) + EmitStoreOfScalar(RV.getScalarVal(), Args.back(), false, + TypeAlign, I->Ty); + else + StoreComplexToAddr(RV.getComplexVal(), Args.back(), false); + + // Validate argument match. + checkArgMatches(AI, IRArgNo, IRFuncTy); + } else { + // We want to avoid creating an unnecessary temporary+copy here; + // however, we need one in two cases: + // 1. If the argument is not byval, and we are required to copy the + // source. (This case doesn't occur on any common architecture.) + // 2. If the argument is byval, RV is not sufficiently aligned, and + // we cannot force it to be sufficiently aligned. + llvm::Value *Addr = RV.getAggregateAddr(); + unsigned Align = ArgInfo.getIndirectAlign(); + const llvm::TargetData *TD = &CGM.getTargetData(); + if ((!ArgInfo.getIndirectByVal() && I->NeedsCopy) || + (ArgInfo.getIndirectByVal() && TypeAlign < Align && + llvm::getOrEnforceKnownAlignment(Addr, Align, TD) < Align)) { + // Create an aligned temporary, and copy to it. + llvm::AllocaInst *AI = CreateMemTemp(I->Ty); + if (Align > AI->getAlignment()) + AI->setAlignment(Align); + Args.push_back(AI); + EmitAggregateCopy(AI, Addr, I->Ty, RV.isVolatileQualified()); + + // Validate argument match. + checkArgMatches(AI, IRArgNo, IRFuncTy); + } else { + // Skip the extra memcpy call. + Args.push_back(Addr); + + // Validate argument match. + checkArgMatches(Addr, IRArgNo, IRFuncTy); + } + } + break; + } + + case ABIArgInfo::Ignore: + break; + + case ABIArgInfo::Extend: + case ABIArgInfo::Direct: { + // Insert a padding argument to ensure proper alignment. + if (llvm::Type *PaddingType = ArgInfo.getPaddingType()) { + Args.push_back(llvm::UndefValue::get(PaddingType)); + ++IRArgNo; + } + + if (!isa<llvm::StructType>(ArgInfo.getCoerceToType()) && + ArgInfo.getCoerceToType() == ConvertType(info_it->type) && + ArgInfo.getDirectOffset() == 0) { + llvm::Value *V; + if (RV.isScalar()) + V = RV.getScalarVal(); + else + V = Builder.CreateLoad(RV.getAggregateAddr()); + + // If the argument doesn't match, perform a bitcast to coerce it. This + // can happen due to trivial type mismatches. + if (IRArgNo < IRFuncTy->getNumParams() && + V->getType() != IRFuncTy->getParamType(IRArgNo)) + V = Builder.CreateBitCast(V, IRFuncTy->getParamType(IRArgNo)); + Args.push_back(V); + + checkArgMatches(V, IRArgNo, IRFuncTy); + break; + } + + // FIXME: Avoid the conversion through memory if possible. + llvm::Value *SrcPtr; + if (RV.isScalar()) { + SrcPtr = CreateMemTemp(I->Ty, "coerce"); + EmitStoreOfScalar(RV.getScalarVal(), SrcPtr, false, TypeAlign, I->Ty); + } else if (RV.isComplex()) { + SrcPtr = CreateMemTemp(I->Ty, "coerce"); + StoreComplexToAddr(RV.getComplexVal(), SrcPtr, false); + } else + SrcPtr = RV.getAggregateAddr(); + + // If the value is offset in memory, apply the offset now. + if (unsigned Offs = ArgInfo.getDirectOffset()) { + SrcPtr = Builder.CreateBitCast(SrcPtr, Builder.getInt8PtrTy()); + SrcPtr = Builder.CreateConstGEP1_32(SrcPtr, Offs); + SrcPtr = Builder.CreateBitCast(SrcPtr, + llvm::PointerType::getUnqual(ArgInfo.getCoerceToType())); + + } + + // If the coerce-to type is a first class aggregate, we flatten it and + // pass the elements. Either way is semantically identical, but fast-isel + // and the optimizer generally likes scalar values better than FCAs. + if (llvm::StructType *STy = + dyn_cast<llvm::StructType>(ArgInfo.getCoerceToType())) { + SrcPtr = Builder.CreateBitCast(SrcPtr, + llvm::PointerType::getUnqual(STy)); + for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) { + llvm::Value *EltPtr = Builder.CreateConstGEP2_32(SrcPtr, 0, i); + llvm::LoadInst *LI = Builder.CreateLoad(EltPtr); + // We don't know what we're loading from. + LI->setAlignment(1); + Args.push_back(LI); + + // Validate argument match. + checkArgMatches(LI, IRArgNo, IRFuncTy); + } + } else { + // In the simple case, just pass the coerced loaded value. + Args.push_back(CreateCoercedLoad(SrcPtr, ArgInfo.getCoerceToType(), + *this)); + + // Validate argument match. + checkArgMatches(Args.back(), IRArgNo, IRFuncTy); + } + + break; + } + + case ABIArgInfo::Expand: + ExpandTypeToArgs(I->Ty, RV, Args, IRFuncTy); + IRArgNo = Args.size(); + break; + } + } + + // If the callee is a bitcast of a function to a varargs pointer to function + // type, check to see if we can remove the bitcast. This handles some cases + // with unprototyped functions. + if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Callee)) + if (llvm::Function *CalleeF = dyn_cast<llvm::Function>(CE->getOperand(0))) { + llvm::PointerType *CurPT=cast<llvm::PointerType>(Callee->getType()); + llvm::FunctionType *CurFT = + cast<llvm::FunctionType>(CurPT->getElementType()); + llvm::FunctionType *ActualFT = CalleeF->getFunctionType(); + + if (CE->getOpcode() == llvm::Instruction::BitCast && + ActualFT->getReturnType() == CurFT->getReturnType() && + ActualFT->getNumParams() == CurFT->getNumParams() && + ActualFT->getNumParams() == Args.size() && + (CurFT->isVarArg() || !ActualFT->isVarArg())) { + bool ArgsMatch = true; + for (unsigned i = 0, e = ActualFT->getNumParams(); i != e; ++i) + if (ActualFT->getParamType(i) != CurFT->getParamType(i)) { + ArgsMatch = false; + break; + } + + // Strip the cast if we can get away with it. This is a nice cleanup, + // but also allows us to inline the function at -O0 if it is marked + // always_inline. + if (ArgsMatch) + Callee = CalleeF; + } + } + + unsigned CallingConv; + CodeGen::AttributeListType AttributeList; + CGM.ConstructAttributeList(CallInfo, TargetDecl, AttributeList, CallingConv); + llvm::AttrListPtr Attrs = llvm::AttrListPtr::get(AttributeList.begin(), + AttributeList.end()); + + llvm::BasicBlock *InvokeDest = 0; + if (!(Attrs.getFnAttributes() & llvm::Attribute::NoUnwind)) + InvokeDest = getInvokeDest(); + + llvm::CallSite CS; + if (!InvokeDest) { + CS = Builder.CreateCall(Callee, Args); + } else { + llvm::BasicBlock *Cont = createBasicBlock("invoke.cont"); + CS = Builder.CreateInvoke(Callee, Cont, InvokeDest, Args); + EmitBlock(Cont); + } + if (callOrInvoke) + *callOrInvoke = CS.getInstruction(); + + CS.setAttributes(Attrs); + CS.setCallingConv(static_cast<llvm::CallingConv::ID>(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()) { + Builder.CreateUnreachable(); + Builder.ClearInsertionPoint(); + + // FIXME: For now, emit a dummy basic block because expr emitters in + // generally are not ready to handle emitting expressions at unreachable + // points. + EnsureInsertPoint(); + + // Return a reasonable RValue. + return GetUndefRValue(RetTy); + } + + llvm::Instruction *CI = CS.getInstruction(); + if (Builder.isNamePreserving() && !CI->getType()->isVoidTy()) + CI->setName("call"); + + // Emit any writebacks immediately. Arguably this should happen + // after any return-value munging. + if (CallArgs.hasWritebacks()) + emitWritebacks(*this, CallArgs); + + switch (RetAI.getKind()) { + case ABIArgInfo::Indirect: { + unsigned Alignment = getContext().getTypeAlignInChars(RetTy).getQuantity(); + if (RetTy->isAnyComplexType()) + return RValue::getComplex(LoadComplexFromAddr(Args[0], false)); + if (CodeGenFunction::hasAggregateLLVMType(RetTy)) + return RValue::getAggregate(Args[0]); + return RValue::get(EmitLoadOfScalar(Args[0], false, Alignment, RetTy)); + } + + case ABIArgInfo::Ignore: + // If we are ignoring an argument that had a result, make sure to + // construct the appropriate return value for our caller. + return GetUndefRValue(RetTy); + + case ABIArgInfo::Extend: + case ABIArgInfo::Direct: { + llvm::Type *RetIRTy = ConvertType(RetTy); + if (RetAI.getCoerceToType() == RetIRTy && RetAI.getDirectOffset() == 0) { + if (RetTy->isAnyComplexType()) { + llvm::Value *Real = Builder.CreateExtractValue(CI, 0); + llvm::Value *Imag = Builder.CreateExtractValue(CI, 1); + return RValue::getComplex(std::make_pair(Real, Imag)); + } + if (CodeGenFunction::hasAggregateLLVMType(RetTy)) { + llvm::Value *DestPtr = ReturnValue.getValue(); + bool DestIsVolatile = ReturnValue.isVolatile(); + + if (!DestPtr) { + DestPtr = CreateMemTemp(RetTy, "agg.tmp"); + DestIsVolatile = false; + } + BuildAggStore(*this, CI, DestPtr, DestIsVolatile, false); + return RValue::getAggregate(DestPtr); + } + + // If the argument doesn't match, perform a bitcast to coerce it. This + // can happen due to trivial type mismatches. + llvm::Value *V = CI; + if (V->getType() != RetIRTy) + V = Builder.CreateBitCast(V, RetIRTy); + return RValue::get(V); + } + + llvm::Value *DestPtr = ReturnValue.getValue(); + bool DestIsVolatile = ReturnValue.isVolatile(); + + if (!DestPtr) { + DestPtr = CreateMemTemp(RetTy, "coerce"); + DestIsVolatile = false; + } + + // If the value is offset in memory, apply the offset now. + llvm::Value *StorePtr = DestPtr; + if (unsigned Offs = RetAI.getDirectOffset()) { + StorePtr = Builder.CreateBitCast(StorePtr, Builder.getInt8PtrTy()); + StorePtr = Builder.CreateConstGEP1_32(StorePtr, Offs); + StorePtr = Builder.CreateBitCast(StorePtr, + llvm::PointerType::getUnqual(RetAI.getCoerceToType())); + } + CreateCoercedStore(CI, StorePtr, DestIsVolatile, *this); + + unsigned Alignment = getContext().getTypeAlignInChars(RetTy).getQuantity(); + if (RetTy->isAnyComplexType()) + return RValue::getComplex(LoadComplexFromAddr(DestPtr, false)); + if (CodeGenFunction::hasAggregateLLVMType(RetTy)) + return RValue::getAggregate(DestPtr); + return RValue::get(EmitLoadOfScalar(DestPtr, false, Alignment, RetTy)); + } + + case ABIArgInfo::Expand: + llvm_unreachable("Invalid ABI kind for return argument"); + } + + llvm_unreachable("Unhandled ABIArgInfo::Kind"); +} + +/* VarArg handling */ + +llvm::Value *CodeGenFunction::EmitVAArg(llvm::Value *VAListAddr, QualType Ty) { + return CGM.getTypes().getABIInfo().EmitVAArg(VAListAddr, Ty, *this); +} |