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Diffstat (limited to 'contrib/llvm/tools/clang/lib/CodeGen/CGCall.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/CodeGen/CGCall.cpp | 1122 |
1 files changed, 1122 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/CodeGen/CGCall.cpp b/contrib/llvm/tools/clang/lib/CodeGen/CGCall.cpp new file mode 100644 index 0000000..73cee3c --- /dev/null +++ b/contrib/llvm/tools/clang/lib/CodeGen/CGCall.cpp @@ -0,0 +1,1122 @@ +//===----- CGCall.h - 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 "CodeGenFunction.h" +#include "CodeGenModule.h" +#include "clang/Basic/TargetInfo.h" +#include "clang/AST/Decl.h" +#include "clang/AST/DeclCXX.h" +#include "clang/AST/DeclObjC.h" +#include "clang/CodeGen/CodeGenOptions.h" +#include "llvm/Attributes.h" +#include "llvm/Support/CallSite.h" +#include "llvm/Target/TargetData.h" + +#include "ABIInfo.h" + +using namespace clang; +using namespace CodeGen; + +/***/ + +// FIXME: Use iterator and sidestep silly type array creation. + +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; + } +} + +/// 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(); +} + +const CGFunctionInfo & +CodeGenTypes::getFunctionInfo(CanQual<FunctionNoProtoType> FTNP) { + return getFunctionInfo(FTNP->getResultType().getUnqualifiedType(), + llvm::SmallVector<CanQualType, 16>(), + FTNP->getExtInfo()); +} + +/// \param Args - contains any initial parameters besides those +/// in the formal type +static const CGFunctionInfo &getFunctionInfo(CodeGenTypes &CGT, + llvm::SmallVectorImpl<CanQualType> &ArgTys, + CanQual<FunctionProtoType> FTP) { + // FIXME: Kill copy. + for (unsigned i = 0, e = FTP->getNumArgs(); i != e; ++i) + ArgTys.push_back(FTP->getArgType(i)); + CanQualType ResTy = FTP->getResultType().getUnqualifiedType(); + return CGT.getFunctionInfo(ResTy, ArgTys, + FTP->getExtInfo()); +} + +const CGFunctionInfo & +CodeGenTypes::getFunctionInfo(CanQual<FunctionProtoType> FTP) { + llvm::SmallVector<CanQualType, 16> ArgTys; + return ::getFunctionInfo(*this, ArgTys, 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; + + return CC_C; +} + +const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXRecordDecl *RD, + const FunctionProtoType *FTP) { + llvm::SmallVector<CanQualType, 16> ArgTys; + + // Add the 'this' pointer. + ArgTys.push_back(GetThisType(Context, RD)); + + return ::getFunctionInfo(*this, ArgTys, + FTP->getCanonicalTypeUnqualified().getAs<FunctionProtoType>()); +} + +const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXMethodDecl *MD) { + llvm::SmallVector<CanQualType, 16> ArgTys; + + // Add the 'this' pointer unless this is a static method. + if (MD->isInstance()) + ArgTys.push_back(GetThisType(Context, MD->getParent())); + + return ::getFunctionInfo(*this, ArgTys, GetFormalType(MD)); +} + +const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXConstructorDecl *D, + CXXCtorType Type) { + llvm::SmallVector<CanQualType, 16> ArgTys; + + // Add the 'this' pointer. + ArgTys.push_back(GetThisType(Context, D->getParent())); + + // Check if we need to add a VTT parameter (which has type void **). + if (Type == Ctor_Base && D->getParent()->getNumVBases() != 0) + ArgTys.push_back(Context.getPointerType(Context.VoidPtrTy)); + + return ::getFunctionInfo(*this, ArgTys, GetFormalType(D)); +} + +const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const CXXDestructorDecl *D, + CXXDtorType Type) { + llvm::SmallVector<CanQualType, 16> ArgTys; + + // Add the 'this' pointer. + ArgTys.push_back(GetThisType(Context, D->getParent())); + + // Check if we need to add a VTT parameter (which has type void **). + if (Type == Dtor_Base && D->getParent()->getNumVBases() != 0) + ArgTys.push_back(Context.getPointerType(Context.VoidPtrTy)); + + return ::getFunctionInfo(*this, ArgTys, GetFormalType(D)); +} + +const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const FunctionDecl *FD) { + if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) + if (MD->isInstance()) + return getFunctionInfo(MD); + + CanQualType FTy = FD->getType()->getCanonicalTypeUnqualified(); + assert(isa<FunctionType>(FTy)); + if (isa<FunctionNoProtoType>(FTy)) + return getFunctionInfo(FTy.getAs<FunctionNoProtoType>()); + assert(isa<FunctionProtoType>(FTy)); + return getFunctionInfo(FTy.getAs<FunctionProtoType>()); +} + +const CGFunctionInfo &CodeGenTypes::getFunctionInfo(const ObjCMethodDecl *MD) { + llvm::SmallVector<CanQualType, 16> ArgTys; + ArgTys.push_back(Context.getCanonicalParamType(MD->getSelfDecl()->getType())); + ArgTys.push_back(Context.getCanonicalParamType(Context.getObjCSelType())); + // FIXME: Kill copy? + for (ObjCMethodDecl::param_iterator i = MD->param_begin(), + e = MD->param_end(); i != e; ++i) { + ArgTys.push_back(Context.getCanonicalParamType((*i)->getType())); + } + return getFunctionInfo(GetReturnType(MD->getResultType()), + ArgTys, + FunctionType::ExtInfo( + /*NoReturn*/ false, + /*RegParm*/ 0, + getCallingConventionForDecl(MD))); +} + +const CGFunctionInfo &CodeGenTypes::getFunctionInfo(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 getFunctionInfo(CD, GD.getCtorType()); + + if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(FD)) + return getFunctionInfo(DD, GD.getDtorType()); + + return getFunctionInfo(FD); +} + +const CGFunctionInfo &CodeGenTypes::getFunctionInfo(QualType ResTy, + const CallArgList &Args, + const FunctionType::ExtInfo &Info) { + // FIXME: Kill copy. + llvm::SmallVector<CanQualType, 16> ArgTys; + for (CallArgList::const_iterator i = Args.begin(), e = Args.end(); + i != e; ++i) + ArgTys.push_back(Context.getCanonicalParamType(i->second)); + return getFunctionInfo(GetReturnType(ResTy), ArgTys, Info); +} + +const CGFunctionInfo &CodeGenTypes::getFunctionInfo(QualType ResTy, + const FunctionArgList &Args, + const FunctionType::ExtInfo &Info) { + // FIXME: Kill copy. + llvm::SmallVector<CanQualType, 16> ArgTys; + for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end(); + i != e; ++i) + ArgTys.push_back(Context.getCanonicalParamType(i->second)); + return getFunctionInfo(GetReturnType(ResTy), ArgTys, Info); +} + +const CGFunctionInfo &CodeGenTypes::getFunctionInfo(CanQualType ResTy, + const llvm::SmallVectorImpl<CanQualType> &ArgTys, + const FunctionType::ExtInfo &Info) { +#ifndef NDEBUG + for (llvm::SmallVectorImpl<CanQualType>::const_iterator + I = ArgTys.begin(), E = ArgTys.end(); I != E; ++I) + assert(I->isCanonicalAsParam()); +#endif + + unsigned CC = ClangCallConvToLLVMCallConv(Info.getCC()); + + // Lookup or create unique function info. + llvm::FoldingSetNodeID ID; + CGFunctionInfo::Profile(ID, Info, ResTy, + ArgTys.begin(), ArgTys.end()); + + void *InsertPos = 0; + CGFunctionInfo *FI = FunctionInfos.FindNodeOrInsertPos(ID, InsertPos); + if (FI) + return *FI; + + // Construct the function info. + FI = new CGFunctionInfo(CC, Info.getNoReturn(), Info.getRegParm(), ResTy, ArgTys); + FunctionInfos.InsertNode(FI, InsertPos); + + // Compute ABI information. + getABIInfo().computeInfo(*FI, getContext(), TheModule.getContext()); + + return *FI; +} + +CGFunctionInfo::CGFunctionInfo(unsigned _CallingConvention, + bool _NoReturn, + unsigned _RegParm, + CanQualType ResTy, + const llvm::SmallVectorImpl<CanQualType> &ArgTys) + : CallingConvention(_CallingConvention), + EffectiveCallingConvention(_CallingConvention), + NoReturn(_NoReturn), RegParm(_RegParm) +{ + NumArgs = ArgTys.size(); + Args = new ArgInfo[1 + NumArgs]; + Args[0].type = ResTy; + for (unsigned i = 0; i < NumArgs; ++i) + Args[1 + i].type = ArgTys[i]; +} + +/***/ + +void CodeGenTypes::GetExpandedTypes(QualType Ty, + std::vector<const llvm::Type*> &ArgTys) { + const RecordType *RT = Ty->getAsStructureType(); + assert(RT && "Can only expand structure types."); + const RecordDecl *RD = RT->getDecl(); + assert(!RD->hasFlexibleArrayMember() && + "Cannot expand structure with flexible array."); + + for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); + i != e; ++i) { + const FieldDecl *FD = *i; + assert(!FD->isBitField() && + "Cannot expand structure with bit-field members."); + + QualType FT = FD->getType(); + if (CodeGenFunction::hasAggregateLLVMType(FT)) { + GetExpandedTypes(FT, ArgTys); + } else { + ArgTys.push_back(ConvertType(FT)); + } + } +} + +llvm::Function::arg_iterator +CodeGenFunction::ExpandTypeFromArgs(QualType Ty, LValue LV, + llvm::Function::arg_iterator AI) { + const RecordType *RT = Ty->getAsStructureType(); + assert(RT && "Can only expand structure types."); + + RecordDecl *RD = RT->getDecl(); + assert(LV.isSimple() && + "Unexpected non-simple lvalue during struct expansion."); + llvm::Value *Addr = LV.getAddress(); + for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); + i != e; ++i) { + FieldDecl *FD = *i; + QualType FT = FD->getType(); + + // FIXME: What are the right qualifiers here? + LValue LV = EmitLValueForField(Addr, FD, 0); + if (CodeGenFunction::hasAggregateLLVMType(FT)) { + AI = ExpandTypeFromArgs(FT, LV, AI); + } else { + EmitStoreThroughLValue(RValue::get(AI), LV, FT); + ++AI; + } + } + + return AI; +} + +void +CodeGenFunction::ExpandTypeToArgs(QualType Ty, RValue RV, + llvm::SmallVector<llvm::Value*, 16> &Args) { + const RecordType *RT = Ty->getAsStructureType(); + assert(RT && "Can only expand structure types."); + + RecordDecl *RD = RT->getDecl(); + assert(RV.isAggregate() && "Unexpected rvalue during struct expansion"); + llvm::Value *Addr = RV.getAggregateAddr(); + for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end(); + i != e; ++i) { + FieldDecl *FD = *i; + QualType FT = FD->getType(); + + // FIXME: What are the right qualifiers here? + LValue LV = EmitLValueForField(Addr, FD, 0); + if (CodeGenFunction::hasAggregateLLVMType(FT)) { + ExpandTypeToArgs(FT, RValue::getAggregate(LV.getAddress()), Args); + } else { + RValue RV = EmitLoadOfLValue(LV, FT); + assert(RV.isScalar() && + "Unexpected non-scalar rvalue during struct expansion."); + Args.push_back(RV.getScalarVal()); + } + } +} + +/// CreateCoercedLoad - Create a load from \arg SrcPtr interpreted as +/// a pointer to an object of type \arg Ty. +/// +/// This safely handles the case when the src type is smaller than the +/// destination type; in this situation the values of bits which not +/// present in the src are undefined. +static llvm::Value *CreateCoercedLoad(llvm::Value *SrcPtr, + const llvm::Type *Ty, + CodeGenFunction &CGF) { + const llvm::Type *SrcTy = + cast<llvm::PointerType>(SrcPtr->getType())->getElementType(); + uint64_t SrcSize = CGF.CGM.getTargetData().getTypeAllocSize(SrcTy); + uint64_t DstSize = CGF.CGM.getTargetData().getTypeAllocSize(Ty); + + // 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; + } else { + // 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); + } +} + +/// CreateCoercedStore - Create a store to \arg DstPtr from \arg Src, +/// where the source and destination may have different types. +/// +/// This safely handles the case when the src type is larger than the +/// destination type; the upper bits of the src will be lost. +static void CreateCoercedStore(llvm::Value *Src, + llvm::Value *DstPtr, + bool DstIsVolatile, + CodeGenFunction &CGF) { + const llvm::Type *SrcTy = Src->getType(); + const llvm::Type *DstTy = + cast<llvm::PointerType>(DstPtr->getType())->getElementType(); + + uint64_t SrcSize = CGF.CGM.getTargetData().getTypeAllocSize(SrcTy); + 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. + CGF.Builder.CreateStore(Src, Casted, DstIsVolatile)->setAlignment(1); + } 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(); +} + +const llvm::FunctionType *CodeGenTypes::GetFunctionType(GlobalDecl GD) { + const CGFunctionInfo &FI = getFunctionInfo(GD); + + // For definition purposes, don't consider a K&R function variadic. + bool Variadic = false; + if (const FunctionProtoType *FPT = + cast<FunctionDecl>(GD.getDecl())->getType()->getAs<FunctionProtoType>()) + Variadic = FPT->isVariadic(); + + return GetFunctionType(FI, Variadic); +} + +const llvm::FunctionType * +CodeGenTypes::GetFunctionType(const CGFunctionInfo &FI, bool IsVariadic) { + std::vector<const llvm::Type*> ArgTys; + + const llvm::Type *ResultType = 0; + + QualType RetTy = FI.getReturnType(); + const ABIArgInfo &RetAI = FI.getReturnInfo(); + switch (RetAI.getKind()) { + case ABIArgInfo::Expand: + assert(0 && "Invalid ABI kind for return argument"); + + case ABIArgInfo::Extend: + case ABIArgInfo::Direct: + ResultType = ConvertType(RetTy); + break; + + case ABIArgInfo::Indirect: { + assert(!RetAI.getIndirectAlign() && "Align unused on indirect return."); + ResultType = llvm::Type::getVoidTy(getLLVMContext()); + const llvm::Type *STy = ConvertType(RetTy); + ArgTys.push_back(llvm::PointerType::get(STy, RetTy.getAddressSpace())); + break; + } + + case ABIArgInfo::Ignore: + ResultType = llvm::Type::getVoidTy(getLLVMContext()); + break; + + case ABIArgInfo::Coerce: + ResultType = RetAI.getCoerceToType(); + break; + } + + for (CGFunctionInfo::const_arg_iterator it = FI.arg_begin(), + ie = FI.arg_end(); it != ie; ++it) { + const ABIArgInfo &AI = it->info; + + switch (AI.getKind()) { + case ABIArgInfo::Ignore: + break; + + case ABIArgInfo::Coerce: + ArgTys.push_back(AI.getCoerceToType()); + break; + + case ABIArgInfo::Indirect: { + // indirect arguments are always on the stack, which is addr space #0. + const llvm::Type *LTy = ConvertTypeForMem(it->type); + ArgTys.push_back(llvm::PointerType::getUnqual(LTy)); + break; + } + + case ABIArgInfo::Extend: + case ABIArgInfo::Direct: + ArgTys.push_back(ConvertType(it->type)); + break; + + case ABIArgInfo::Expand: + GetExpandedTypes(it->type, ArgTys); + break; + } + } + + return llvm::FunctionType::get(ResultType, ArgTys, IsVariadic); +} + +static bool HasIncompleteReturnTypeOrArgumentTypes(const FunctionProtoType *T) { + if (const TagType *TT = T->getResultType()->getAs<TagType>()) { + if (!TT->getDecl()->isDefinition()) + return true; + } + + for (unsigned i = 0, e = T->getNumArgs(); i != e; ++i) { + if (const TagType *TT = T->getArgType(i)->getAs<TagType>()) { + if (!TT->getDecl()->isDefinition()) + return true; + } + } + + return false; +} + +const llvm::Type * +CodeGenTypes::GetFunctionTypeForVTable(const CXXMethodDecl *MD) { + const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>(); + + if (!HasIncompleteReturnTypeOrArgumentTypes(FPT)) + return GetFunctionType(getFunctionInfo(MD), FPT->isVariadic()); + + return llvm::OpaqueType::get(getLLVMContext()); +} + +void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI, + const Decl *TargetDecl, + AttributeListType &PAL, + unsigned &CallingConv) { + unsigned FuncAttrs = 0; + unsigned RetAttrs = 0; + + CallingConv = FI.getEffectiveCallingConvention(); + + if (FI.isNoReturn()) + FuncAttrs |= llvm::Attribute::NoReturn; + + // FIXME: handle sseregparm someday... + if (TargetDecl) { + if (TargetDecl->hasAttr<NoThrowAttr>()) + FuncAttrs |= llvm::Attribute::NoUnwind; + if (TargetDecl->hasAttr<NoReturnAttr>()) + FuncAttrs |= llvm::Attribute::NoReturn; + if (TargetDecl->hasAttr<ConstAttr>()) + FuncAttrs |= llvm::Attribute::ReadNone; + else if (TargetDecl->hasAttr<PureAttr>()) + FuncAttrs |= llvm::Attribute::ReadOnly; + 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->isSignedIntegerType()) { + RetAttrs |= llvm::Attribute::SExt; + } else if (RetTy->isUnsignedIntegerType()) { + RetAttrs |= llvm::Attribute::ZExt; + } + // FALLTHROUGH + case ABIArgInfo::Direct: + 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::Ignore: + case ABIArgInfo::Coerce: + break; + + case ABIArgInfo::Expand: + assert(0 && "Invalid ABI kind for return argument"); + } + + if (RetAttrs) + PAL.push_back(llvm::AttributeWithIndex::get(0, RetAttrs)); + + // FIXME: we need to honour command line settings also... + // FIXME: RegParm should be reduced in case of nested functions and/or global + // register variable. + signed RegParm = FI.getRegParm(); + + unsigned PointerWidth = getContext().Target.getPointerWidth(0); + for (CGFunctionInfo::const_arg_iterator it = FI.arg_begin(), + ie = FI.arg_end(); it != ie; ++it) { + QualType ParamType = it->type; + const ABIArgInfo &AI = it->info; + unsigned Attributes = 0; + + // 'restrict' -> 'noalias' is done in EmitFunctionProlog when we + // have the corresponding parameter variable. It doesn't make + // sense to do it here because parameters are so fucked up. + + switch (AI.getKind()) { + case ABIArgInfo::Coerce: + break; + + case ABIArgInfo::Indirect: + if (AI.getIndirectByVal()) + Attributes |= llvm::Attribute::ByVal; + + Attributes |= + llvm::Attribute::constructAlignmentFromInt(AI.getIndirectAlign()); + // byval disables readnone and readonly. + FuncAttrs &= ~(llvm::Attribute::ReadOnly | + llvm::Attribute::ReadNone); + break; + + case ABIArgInfo::Extend: + if (ParamType->isSignedIntegerType()) { + Attributes |= llvm::Attribute::SExt; + } else if (ParamType->isUnsignedIntegerType()) { + Attributes |= llvm::Attribute::ZExt; + } + // FALLS THROUGH + case ABIArgInfo::Direct: + if (RegParm > 0 && + (ParamType->isIntegerType() || ParamType->isPointerType())) { + RegParm -= + (Context.getTypeSize(ParamType) + PointerWidth - 1) / PointerWidth; + if (RegParm >= 0) + Attributes |= llvm::Attribute::InReg; + } + // FIXME: handle sseregparm someday... + break; + + case ABIArgInfo::Ignore: + // Skip increment, no matching LLVM parameter. + continue; + + case ABIArgInfo::Expand: { + std::vector<const llvm::Type*> Tys; + // 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, Tys); + Index += Tys.size(); + continue; + } + } + + if (Attributes) + PAL.push_back(llvm::AttributeWithIndex::get(Index, Attributes)); + ++Index; + } + if (FuncAttrs) + PAL.push_back(llvm::AttributeWithIndex::get(~0, FuncAttrs)); +} + +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(); + const llvm::Type* LLVMTy = CGM.getTypes().ConvertType(RetTy); + llvm::Constant* Zero = llvm::Constant::getNullValue(LLVMTy); + Builder.CreateStore(Zero, ReturnValue); + } + } + + // FIXME: We no longer need the types from FunctionArgList; lift up and + // simplify. + + // Emit allocs for param decls. Give the LLVM Argument nodes names. + llvm::Function::arg_iterator AI = Fn->arg_begin(); + + // Name the struct return argument. + if (CGM.ReturnTypeUsesSret(FI)) { + AI->setName("agg.result"); + ++AI; + } + + assert(FI.arg_size() == Args.size() && + "Mismatch between function signature & arguments."); + CGFunctionInfo::const_arg_iterator info_it = FI.arg_begin(); + for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end(); + i != e; ++i, ++info_it) { + const VarDecl *Arg = i->first; + QualType Ty = info_it->type; + const ABIArgInfo &ArgI = info_it->info; + + switch (ArgI.getKind()) { + case ABIArgInfo::Indirect: { + llvm::Value* V = AI; + if (hasAggregateLLVMType(Ty)) { + // Do nothing, aggregates and complex variables are accessed by + // reference. + } else { + // Load scalar value from indirect argument. + V = EmitLoadOfScalar(V, false, Ty); + if (!getContext().typesAreCompatible(Ty, Arg->getType())) { + // This must be a promotion, for something like + // "void a(x) short x; {..." + V = EmitScalarConversion(V, Ty, Arg->getType()); + } + } + EmitParmDecl(*Arg, V); + break; + } + + case ABIArgInfo::Extend: + case ABIArgInfo::Direct: { + assert(AI != Fn->arg_end() && "Argument mismatch!"); + llvm::Value* V = AI; + if (hasAggregateLLVMType(Ty)) { + // Create a temporary alloca to hold the argument; the rest of + // codegen expects to access aggregates & complex values by + // reference. + V = CreateMemTemp(Ty); + Builder.CreateStore(AI, V); + } else { + if (Arg->getType().isRestrictQualified()) + AI->addAttr(llvm::Attribute::NoAlias); + + if (!getContext().typesAreCompatible(Ty, Arg->getType())) { + // This must be a promotion, for something like + // "void a(x) short x; {..." + V = EmitScalarConversion(V, Ty, Arg->getType()); + } + } + EmitParmDecl(*Arg, V); + 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::Value *Temp = CreateMemTemp(Ty, Arg->getName() + ".addr"); + // FIXME: What are the right qualifiers here? + llvm::Function::arg_iterator End = + ExpandTypeFromArgs(Ty, LValue::MakeAddr(Temp, Qualifiers()), AI); + EmitParmDecl(*Arg, Temp); + + // Name the arguments used in expansion and increment AI. + unsigned Index = 0; + for (; AI != End; ++AI, ++Index) + AI->setName(Arg->getName() + "." + llvm::Twine(Index)); + continue; + } + + case ABIArgInfo::Ignore: + // Initialize the local variable appropriately. + if (hasAggregateLLVMType(Ty)) { + EmitParmDecl(*Arg, CreateMemTemp(Ty)); + } else { + EmitParmDecl(*Arg, llvm::UndefValue::get(ConvertType(Arg->getType()))); + } + + // Skip increment, no matching LLVM parameter. + continue; + + case ABIArgInfo::Coerce: { + assert(AI != Fn->arg_end() && "Argument mismatch!"); + // FIXME: This is very wasteful; EmitParmDecl is just going to drop the + // result in a new alloca anyway, so we could just store into that + // directly if we broke the abstraction down more. + llvm::Value *V = CreateMemTemp(Ty, "coerce"); + CreateCoercedStore(AI, V, /*DestIsVolatile=*/false, *this); + // Match to what EmitParmDecl is expecting for this type. + if (!CodeGenFunction::hasAggregateLLVMType(Ty)) { + V = EmitLoadOfScalar(V, false, Ty); + if (!getContext().typesAreCompatible(Ty, Arg->getType())) { + // This must be a promotion, for something like + // "void a(x) short x; {..." + V = EmitScalarConversion(V, Ty, Arg->getType()); + } + } + EmitParmDecl(*Arg, V); + break; + } + } + + ++AI; + } + assert(AI == Fn->arg_end() && "Argument mismatch!"); +} + +void CodeGenFunction::EmitFunctionEpilog(const CGFunctionInfo &FI, + llvm::Value *ReturnValue) { + llvm::Value *RV = 0; + + // Functions with no result always return void. + if (ReturnValue) { + QualType RetTy = FI.getReturnType(); + const ABIArgInfo &RetAI = FI.getReturnInfo(); + + switch (RetAI.getKind()) { + case ABIArgInfo::Indirect: + 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, RetTy); + } + break; + + case ABIArgInfo::Extend: + case ABIArgInfo::Direct: + // The internal return value temp always will have + // pointer-to-return-type type. + RV = Builder.CreateLoad(ReturnValue); + break; + + case ABIArgInfo::Ignore: + break; + + case ABIArgInfo::Coerce: + RV = CreateCoercedLoad(ReturnValue, RetAI.getCoerceToType(), *this); + break; + + case ABIArgInfo::Expand: + assert(0 && "Invalid ABI kind for return argument"); + } + } + + if (RV) { + Builder.CreateRet(RV); + } else { + Builder.CreateRetVoid(); + } +} + +RValue CodeGenFunction::EmitDelegateCallArg(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 ArgType = 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 *RefType = ArgType->getAs<ReferenceType>()) { + if (hasAggregateLLVMType(RefType->getPointeeType())) + return RValue::getAggregate(Local); + + // Locals which are references to scalars are represented + // with allocas holding the pointer. + return RValue::get(Builder.CreateLoad(Local)); + } + + if (ArgType->isAnyComplexType()) + return RValue::getComplex(LoadComplexFromAddr(Local, /*volatile*/ false)); + + if (hasAggregateLLVMType(ArgType)) + return RValue::getAggregate(Local); + + return RValue::get(EmitLoadOfScalar(Local, false, ArgType)); +} + +RValue CodeGenFunction::EmitCallArg(const Expr *E, QualType ArgType) { + if (ArgType->isReferenceType()) + return EmitReferenceBindingToExpr(E); + + return EmitAnyExprToTemp(E); +} + +RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo, + llvm::Value *Callee, + ReturnValueSlot ReturnValue, + const CallArgList &CallArgs, + const Decl *TargetDecl, + llvm::Instruction **callOrInvoke) { + // FIXME: We no longer need the types from CallArgs; lift up and simplify. + llvm::SmallVector<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(); + + + // 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); + } + + 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->first; + + switch (ArgInfo.getKind()) { + case ABIArgInfo::Indirect: + if (RV.isScalar() || RV.isComplex()) { + // Make a temporary alloca to pass the argument. + Args.push_back(CreateMemTemp(I->second)); + if (RV.isScalar()) + EmitStoreOfScalar(RV.getScalarVal(), Args.back(), false, I->second); + else + StoreComplexToAddr(RV.getComplexVal(), Args.back(), false); + } else { + Args.push_back(RV.getAggregateAddr()); + } + break; + + case ABIArgInfo::Extend: + case ABIArgInfo::Direct: + if (RV.isScalar()) { + Args.push_back(RV.getScalarVal()); + } else if (RV.isComplex()) { + llvm::Value *Tmp = llvm::UndefValue::get(ConvertType(I->second)); + Tmp = Builder.CreateInsertValue(Tmp, RV.getComplexVal().first, 0); + Tmp = Builder.CreateInsertValue(Tmp, RV.getComplexVal().second, 1); + Args.push_back(Tmp); + } else { + Args.push_back(Builder.CreateLoad(RV.getAggregateAddr())); + } + break; + + case ABIArgInfo::Ignore: + break; + + case ABIArgInfo::Coerce: { + // FIXME: Avoid the conversion through memory if possible. + llvm::Value *SrcPtr; + if (RV.isScalar()) { + SrcPtr = CreateMemTemp(I->second, "coerce"); + EmitStoreOfScalar(RV.getScalarVal(), SrcPtr, false, I->second); + } else if (RV.isComplex()) { + SrcPtr = CreateMemTemp(I->second, "coerce"); + StoreComplexToAddr(RV.getComplexVal(), SrcPtr, false); + } else + SrcPtr = RV.getAggregateAddr(); + Args.push_back(CreateCoercedLoad(SrcPtr, ArgInfo.getCoerceToType(), + *this)); + break; + } + + case ABIArgInfo::Expand: + ExpandTypeToArgs(I->second, RV, Args); + 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))) { + const llvm::PointerType *CurPT=cast<llvm::PointerType>(Callee->getType()); + const llvm::FunctionType *CurFT = + cast<llvm::FunctionType>(CurPT->getElementType()); + const llvm::FunctionType *ActualFT = CalleeF->getFunctionType(); + + if (CE->getOpcode() == llvm::Instruction::BitCast && + ActualFT->getReturnType() == CurFT->getReturnType() && + ActualFT->getNumParams() == CurFT->getNumParams() && + ActualFT->getNumParams() == Args.size()) { + 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; + } + } + + + llvm::BasicBlock *InvokeDest = getInvokeDest(); + unsigned CallingConv; + CodeGen::AttributeListType AttributeList; + CGM.ConstructAttributeList(CallInfo, TargetDecl, AttributeList, CallingConv); + llvm::AttrListPtr Attrs = llvm::AttrListPtr::get(AttributeList.begin(), + AttributeList.end()); + + llvm::CallSite CS; + if (!InvokeDest || (Attrs.getFnAttributes() & llvm::Attribute::NoUnwind)) { + CS = Builder.CreateCall(Callee, Args.data(), Args.data()+Args.size()); + } else { + llvm::BasicBlock *Cont = createBasicBlock("invoke.cont"); + CS = Builder.CreateInvoke(Callee, Cont, InvokeDest, + Args.data(), Args.data()+Args.size()); + EmitBlock(Cont); + } + if (callOrInvoke) { + *callOrInvoke = CS.getInstruction(); + } + + CS.setAttributes(Attrs); + CS.setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv)); + + // If the call doesn't return, finish the basic block and clear the + // insertion point; this allows the rest of IRgen to discard + // unreachable code. + if (CS.doesNotReturn()) { + Builder.CreateUnreachable(); + Builder.ClearInsertionPoint(); + + // FIXME: For now, emit a dummy basic block because expr emitters in + // generally are not ready to handle emitting expressions at unreachable + // points. + EnsureInsertPoint(); + + // Return a reasonable RValue. + return GetUndefRValue(RetTy); + } + + llvm::Instruction *CI = CS.getInstruction(); + if (Builder.isNamePreserving() && !CI->getType()->isVoidTy()) + CI->setName("call"); + + switch (RetAI.getKind()) { + case ABIArgInfo::Indirect: + 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, RetTy)); + + case ABIArgInfo::Extend: + case ABIArgInfo::Direct: + 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; + } + Builder.CreateStore(CI, DestPtr, DestIsVolatile); + return RValue::getAggregate(DestPtr); + } + return RValue::get(CI); + + 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::Coerce: { + llvm::Value *DestPtr = ReturnValue.getValue(); + bool DestIsVolatile = ReturnValue.isVolatile(); + + if (!DestPtr) { + DestPtr = CreateMemTemp(RetTy, "coerce"); + DestIsVolatile = false; + } + + CreateCoercedStore(CI, DestPtr, DestIsVolatile, *this); + if (RetTy->isAnyComplexType()) + return RValue::getComplex(LoadComplexFromAddr(DestPtr, false)); + if (CodeGenFunction::hasAggregateLLVMType(RetTy)) + return RValue::getAggregate(DestPtr); + return RValue::get(EmitLoadOfScalar(DestPtr, false, RetTy)); + } + + case ABIArgInfo::Expand: + assert(0 && "Invalid ABI kind for return argument"); + } + + assert(0 && "Unhandled ABIArgInfo::Kind"); + return RValue::get(0); +} + +/* VarArg handling */ + +llvm::Value *CodeGenFunction::EmitVAArg(llvm::Value *VAListAddr, QualType Ty) { + return CGM.getTypes().getABIInfo().EmitVAArg(VAListAddr, Ty, *this); +} |
