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llvm-project/clang/lib/CodeGen/CGCall.cpp

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//===--- CGCall.cpp - Encapsulate calling convention details --------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// These classes wrap the information about a call or function
// definition used to handle ABI compliancy.
//
//===----------------------------------------------------------------------===//
#include "CGCall.h"
#include "ABIInfo.h"
#include "CGCXXABI.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "TargetInfo.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/CodeGen/CGFunctionInfo.h"
#include "clang/Frontend/CodeGenOptions.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/Transforms/Utils/Local.h"
using namespace clang;
using namespace CodeGen;
/***/
static unsigned ClangCallConvToLLVMCallConv(CallingConv CC) {
switch (CC) {
default: return llvm::CallingConv::C;
case CC_X86StdCall: return llvm::CallingConv::X86_StdCall;
case CC_X86FastCall: return llvm::CallingConv::X86_FastCall;
case CC_X86ThisCall: return llvm::CallingConv::X86_ThisCall;
case CC_X86_64Win64: return llvm::CallingConv::X86_64_Win64;
case CC_X86_64SysV: return llvm::CallingConv::X86_64_SysV;
case CC_AAPCS: return llvm::CallingConv::ARM_AAPCS;
case CC_AAPCS_VFP: return llvm::CallingConv::ARM_AAPCS_VFP;
case CC_IntelOclBicc: return llvm::CallingConv::Intel_OCL_BI;
// TODO: Add support for __pascal to LLVM.
case CC_X86Pascal: return llvm::CallingConv::C;
// TODO: Add support for __vectorcall to LLVM.
case CC_X86VectorCall: return llvm::CallingConv::X86_VectorCall;
}
}
/// 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 freestanding function type.
const CGFunctionInfo &
CodeGenTypes::arrangeFreeFunctionType(CanQual<FunctionNoProtoType> FTNP) {
// When translating an unprototyped function type, always use a
// variadic type.
return arrangeLLVMFunctionInfo(FTNP->getReturnType().getUnqualifiedType(),
false, None, FTNP->getExtInfo(),
RequiredArgs(0));
}
/// Arrange the LLVM function layout for a value of the given function
/// type, on top of any implicit parameters already stored.
static const CGFunctionInfo &
arrangeLLVMFunctionInfo(CodeGenTypes &CGT, bool IsInstanceMethod,
SmallVectorImpl<CanQualType> &prefix,
CanQual<FunctionProtoType> FTP) {
RequiredArgs required = RequiredArgs::forPrototypePlus(FTP, prefix.size());
// FIXME: Kill copy.
for (unsigned i = 0, e = FTP->getNumParams(); i != e; ++i)
prefix.push_back(FTP->getParamType(i));
CanQualType resultType = FTP->getReturnType().getUnqualifiedType();
return CGT.arrangeLLVMFunctionInfo(resultType, IsInstanceMethod, prefix,
FTP->getExtInfo(), required);
}
/// Arrange the argument and result information for a value of the
/// given freestanding function type.
const CGFunctionInfo &
CodeGenTypes::arrangeFreeFunctionType(CanQual<FunctionProtoType> FTP) {
SmallVector<CanQualType, 16> argTypes;
return ::arrangeLLVMFunctionInfo(*this, false, argTypes, FTP);
}
static CallingConv getCallingConventionForDecl(const Decl *D, bool IsWindows) {
// 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<VectorCallAttr>())
return CC_X86VectorCall;
if (D->hasAttr<PascalAttr>())
return CC_X86Pascal;
if (PcsAttr *PCS = D->getAttr<PcsAttr>())
return (PCS->getPCS() == PcsAttr::AAPCS ? CC_AAPCS : CC_AAPCS_VFP);
if (D->hasAttr<PnaclCallAttr>())
return CC_PnaclCall;
if (D->hasAttr<IntelOclBiccAttr>())
return CC_IntelOclBicc;
if (D->hasAttr<MSABIAttr>())
return IsWindows ? CC_C : CC_X86_64Win64;
if (D->hasAttr<SysVABIAttr>())
return IsWindows ? CC_X86_64SysV : CC_C;
return CC_C;
}
/// Arrange the argument and result information for a call to an
/// unknown C++ non-static member function of the given abstract type.
/// (Zero value of RD means we don't have any meaningful "this" argument type,
/// so fall back to a generic pointer type).
/// The member function must be an ordinary function, i.e. not a
/// constructor or destructor.
const CGFunctionInfo &
CodeGenTypes::arrangeCXXMethodType(const CXXRecordDecl *RD,
const FunctionProtoType *FTP) {
SmallVector<CanQualType, 16> argTypes;
// Add the 'this' pointer.
if (RD)
argTypes.push_back(GetThisType(Context, RD));
else
argTypes.push_back(Context.VoidPtrTy);
return ::arrangeLLVMFunctionInfo(
*this, true, argTypes,
FTP->getCanonicalTypeUnqualified().getAs<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 constructors!");
assert(!isa<CXXDestructorDecl>(MD) && "wrong method for destructors!");
CanQual<FunctionProtoType> prototype = GetFormalType(MD);
if (MD->isInstance()) {
// The abstract case is perfectly fine.
const CXXRecordDecl *ThisType = TheCXXABI.getThisArgumentTypeForMethod(MD);
return arrangeCXXMethodType(ThisType, prototype.getTypePtr());
}
return arrangeFreeFunctionType(prototype);
}
const CGFunctionInfo &
CodeGenTypes::arrangeCXXStructorDeclaration(const CXXMethodDecl *MD,
StructorType Type) {
SmallVector<CanQualType, 16> argTypes;
argTypes.push_back(GetThisType(Context, MD->getParent()));
GlobalDecl GD;
if (auto *CD = dyn_cast<CXXConstructorDecl>(MD)) {
GD = GlobalDecl(CD, toCXXCtorType(Type));
} else {
auto *DD = dyn_cast<CXXDestructorDecl>(MD);
GD = GlobalDecl(DD, toCXXDtorType(Type));
}
CanQual<FunctionProtoType> FTP = GetFormalType(MD);
// Add the formal parameters.
for (unsigned i = 0, e = FTP->getNumParams(); i != e; ++i)
argTypes.push_back(FTP->getParamType(i));
TheCXXABI.buildStructorSignature(MD, Type, argTypes);
RequiredArgs required =
(MD->isVariadic() ? RequiredArgs(argTypes.size()) : RequiredArgs::All);
FunctionType::ExtInfo extInfo = FTP->getExtInfo();
CanQualType resultType = TheCXXABI.HasThisReturn(GD)
? argTypes.front()
: TheCXXABI.hasMostDerivedReturn(GD)
? CGM.getContext().VoidPtrTy
: Context.VoidTy;
return arrangeLLVMFunctionInfo(resultType, true, argTypes, extInfo, required);
}
/// Arrange a call to a C++ method, passing the given arguments.
const CGFunctionInfo &
CodeGenTypes::arrangeCXXConstructorCall(const CallArgList &args,
const CXXConstructorDecl *D,
CXXCtorType CtorKind,
unsigned ExtraArgs) {
// FIXME: Kill copy.
SmallVector<CanQualType, 16> ArgTypes;
for (const auto &Arg : args)
ArgTypes.push_back(Context.getCanonicalParamType(Arg.Ty));
CanQual<FunctionProtoType> FPT = GetFormalType(D);
RequiredArgs Required = RequiredArgs::forPrototypePlus(FPT, 1 + ExtraArgs);
GlobalDecl GD(D, CtorKind);
CanQualType ResultType = TheCXXABI.HasThisReturn(GD)
? ArgTypes.front()
: TheCXXABI.hasMostDerivedReturn(GD)
? CGM.getContext().VoidPtrTy
: Context.VoidTy;
FunctionType::ExtInfo Info = FPT->getExtInfo();
return arrangeLLVMFunctionInfo(ResultType, true, ArgTypes, Info, Required);
}
/// Arrange the argument and result information for the declaration or
/// definition of the given function.
const CGFunctionInfo &
CodeGenTypes::arrangeFunctionDeclaration(const FunctionDecl *FD) {
if (const CXXMethodDecl *MD = dyn_cast<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 arrangeLLVMFunctionInfo(noProto->getReturnType(), false, None,
noProto->getExtInfo(), RequiredArgs::All);
}
assert(isa<FunctionProtoType>(FTy));
return arrangeFreeFunctionType(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 (const auto *I : MD->params()) {
argTys.push_back(Context.getCanonicalParamType(I->getType()));
}
FunctionType::ExtInfo einfo;
bool IsWindows = getContext().getTargetInfo().getTriple().isOSWindows();
einfo = einfo.withCallingConv(getCallingConventionForDecl(MD, IsWindows));
if (getContext().getLangOpts().ObjCAutoRefCount &&
MD->hasAttr<NSReturnsRetainedAttr>())
einfo = einfo.withProducesResult(true);
RequiredArgs required =
(MD->isVariadic() ? RequiredArgs(argTys.size()) : RequiredArgs::All);
return arrangeLLVMFunctionInfo(GetReturnType(MD->getReturnType()), false,
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 arrangeCXXStructorDeclaration(CD, getFromCtorType(GD.getCtorType()));
if (const CXXDestructorDecl *DD = dyn_cast<CXXDestructorDecl>(FD))
return arrangeCXXStructorDeclaration(DD, getFromDtorType(GD.getDtorType()));
return arrangeFunctionDeclaration(FD);
}
/// Arrange a thunk that takes 'this' as the first parameter followed by
/// varargs. Return a void pointer, regardless of the actual return type.
/// The body of the thunk will end in a musttail call to a function of the
/// correct type, and the caller will bitcast the function to the correct
/// prototype.
const CGFunctionInfo &
CodeGenTypes::arrangeMSMemberPointerThunk(const CXXMethodDecl *MD) {
assert(MD->isVirtual() && "only virtual memptrs have thunks");
CanQual<FunctionProtoType> FTP = GetFormalType(MD);
CanQualType ArgTys[] = { GetThisType(Context, MD->getParent()) };
return arrangeLLVMFunctionInfo(Context.VoidTy, false, ArgTys,
FTP->getExtInfo(), RequiredArgs(1));
}
/// Arrange a call as unto a free function, except possibly with an
/// additional number of formal parameters considered required.
static const CGFunctionInfo &
arrangeFreeFunctionLikeCall(CodeGenTypes &CGT,
CodeGenModule &CGM,
const CallArgList &args,
const FunctionType *fnType,
unsigned numExtraRequiredArgs) {
assert(args.size() >= numExtraRequiredArgs);
// In most cases, there are no optional arguments.
RequiredArgs required = RequiredArgs::All;
// If we have a variadic prototype, the required arguments are the
// extra prefix plus the arguments in the prototype.
if (const FunctionProtoType *proto = dyn_cast<FunctionProtoType>(fnType)) {
if (proto->isVariadic())
required = RequiredArgs(proto->getNumParams() + numExtraRequiredArgs);
// If we don't have a prototype at all, but we're supposed to
// explicitly use the variadic convention for unprototyped calls,
// treat all of the arguments as required but preserve the nominal
// possibility of variadics.
} else if (CGM.getTargetCodeGenInfo()
.isNoProtoCallVariadic(args,
cast<FunctionNoProtoType>(fnType))) {
required = RequiredArgs(args.size());
}
return CGT.arrangeFreeFunctionCall(fnType->getReturnType(), args,
fnType->getExtInfo(), required);
}
/// Figure out the rules for calling a function with the given formal
/// type using the given arguments. The arguments are necessary
/// because the function might be unprototyped, in which case it's
/// target-dependent in crazy ways.
const CGFunctionInfo &
CodeGenTypes::arrangeFreeFunctionCall(const CallArgList &args,
const FunctionType *fnType) {
return arrangeFreeFunctionLikeCall(*this, CGM, args, fnType, 0);
}
/// A block function call is essentially a free-function call with an
/// extra implicit argument.
const CGFunctionInfo &
CodeGenTypes::arrangeBlockFunctionCall(const CallArgList &args,
const FunctionType *fnType) {
return arrangeFreeFunctionLikeCall(*this, CGM, args, fnType, 1);
}
const CGFunctionInfo &
CodeGenTypes::arrangeFreeFunctionCall(QualType resultType,
const CallArgList &args,
FunctionType::ExtInfo info,
RequiredArgs required) {
// FIXME: Kill copy.
SmallVector<CanQualType, 16> argTypes;
for (const auto &Arg : args)
argTypes.push_back(Context.getCanonicalParamType(Arg.Ty));
return arrangeLLVMFunctionInfo(GetReturnType(resultType), false, argTypes,
info, required);
}
/// Arrange a call to a C++ method, passing the given arguments.
const CGFunctionInfo &
CodeGenTypes::arrangeCXXMethodCall(const CallArgList &args,
const FunctionProtoType *FPT,
RequiredArgs required) {
// FIXME: Kill copy.
SmallVector<CanQualType, 16> argTypes;
for (const auto &Arg : args)
argTypes.push_back(Context.getCanonicalParamType(Arg.Ty));
FunctionType::ExtInfo info = FPT->getExtInfo();
return arrangeLLVMFunctionInfo(GetReturnType(FPT->getReturnType()), true,
argTypes, info, required);
}
const CGFunctionInfo &CodeGenTypes::arrangeFreeFunctionDeclaration(
QualType resultType, const FunctionArgList &args,
const FunctionType::ExtInfo &info, bool isVariadic) {
// FIXME: Kill copy.
SmallVector<CanQualType, 16> argTypes;
for (auto Arg : args)
argTypes.push_back(Context.getCanonicalParamType(Arg->getType()));
RequiredArgs required =
(isVariadic ? RequiredArgs(args.size()) : RequiredArgs::All);
return arrangeLLVMFunctionInfo(GetReturnType(resultType), false, argTypes, info,
required);
}
const CGFunctionInfo &CodeGenTypes::arrangeNullaryFunction() {
return arrangeLLVMFunctionInfo(getContext().VoidTy, false, None,
FunctionType::ExtInfo(), RequiredArgs::All);
}
/// Arrange the argument and result information for an abstract value
/// of a given function type. This is the method which all of the
/// above functions ultimately defer to.
const CGFunctionInfo &
CodeGenTypes::arrangeLLVMFunctionInfo(CanQualType resultType,
bool IsInstanceMethod,
ArrayRef<CanQualType> argTypes,
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, IsInstanceMethod, info, required, resultType,
argTypes);
void *insertPos = nullptr;
CGFunctionInfo *FI = FunctionInfos.FindNodeOrInsertPos(ID, insertPos);
if (FI)
return *FI;
// Construct the function info. We co-allocate the ArgInfos.
FI = CGFunctionInfo::create(CC, IsInstanceMethod, info, resultType, argTypes,
required);
FunctionInfos.InsertNode(FI, insertPos);
bool inserted = FunctionsBeingProcessed.insert(FI).second;
(void)inserted;
assert(inserted && "Recursively being processed?");
// Compute ABI information.
getABIInfo().computeInfo(*FI);
// Loop over all of the computed argument and return value info. If any of
// them are direct or extend without a specified coerce type, specify the
// default now.
ABIArgInfo &retInfo = FI->getReturnInfo();
if (retInfo.canHaveCoerceToType() && retInfo.getCoerceToType() == nullptr)
retInfo.setCoerceToType(ConvertType(FI->getReturnType()));
for (auto &I : FI->arguments())
if (I.info.canHaveCoerceToType() && I.info.getCoerceToType() == nullptr)
I.info.setCoerceToType(ConvertType(I.type));
bool erased = FunctionsBeingProcessed.erase(FI); (void)erased;
assert(erased && "Not in set?");
return *FI;
}
CGFunctionInfo *CGFunctionInfo::create(unsigned llvmCC,
bool IsInstanceMethod,
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->InstanceMethod = IsInstanceMethod;
FI->NoReturn = info.getNoReturn();
FI->ReturnsRetained = info.getProducesResult();
FI->Required = required;
FI->HasRegParm = info.getHasRegParm();
FI->RegParm = info.getRegParm();
FI->ArgStruct = nullptr;
FI->NumArgs = argTypes.size();
FI->getArgsBuffer()[0].type = resultType;
for (unsigned i = 0, e = argTypes.size(); i != e; ++i)
FI->getArgsBuffer()[i + 1].type = argTypes[i];
return FI;
}
/***/
namespace {
// ABIArgInfo::Expand implementation.
// Specifies the way QualType passed as ABIArgInfo::Expand is expanded.
struct TypeExpansion {
enum TypeExpansionKind {
// Elements of constant arrays are expanded recursively.
TEK_ConstantArray,
// Record fields are expanded recursively (but if record is a union, only
// the field with the largest size is expanded).
TEK_Record,
// For complex types, real and imaginary parts are expanded recursively.
TEK_Complex,
// All other types are not expandable.
TEK_None
};
const TypeExpansionKind Kind;
TypeExpansion(TypeExpansionKind K) : Kind(K) {}
virtual ~TypeExpansion() {}
};
struct ConstantArrayExpansion : TypeExpansion {
QualType EltTy;
uint64_t NumElts;
ConstantArrayExpansion(QualType EltTy, uint64_t NumElts)
: TypeExpansion(TEK_ConstantArray), EltTy(EltTy), NumElts(NumElts) {}
static bool classof(const TypeExpansion *TE) {
return TE->Kind == TEK_ConstantArray;
}
};
struct RecordExpansion : TypeExpansion {
SmallVector<const CXXBaseSpecifier *, 1> Bases;
SmallVector<const FieldDecl *, 1> Fields;
RecordExpansion(SmallVector<const CXXBaseSpecifier *, 1> &&Bases,
SmallVector<const FieldDecl *, 1> &&Fields)
: TypeExpansion(TEK_Record), Bases(Bases), Fields(Fields) {}
static bool classof(const TypeExpansion *TE) {
return TE->Kind == TEK_Record;
}
};
struct ComplexExpansion : TypeExpansion {
QualType EltTy;
ComplexExpansion(QualType EltTy) : TypeExpansion(TEK_Complex), EltTy(EltTy) {}
static bool classof(const TypeExpansion *TE) {
return TE->Kind == TEK_Complex;
}
};
struct NoExpansion : TypeExpansion {
NoExpansion() : TypeExpansion(TEK_None) {}
static bool classof(const TypeExpansion *TE) {
return TE->Kind == TEK_None;
}
};
} // namespace
static std::unique_ptr<TypeExpansion>
getTypeExpansion(QualType Ty, const ASTContext &Context) {
if (const ConstantArrayType *AT = Context.getAsConstantArrayType(Ty)) {
return llvm::make_unique<ConstantArrayExpansion>(
AT->getElementType(), AT->getSize().getZExtValue());
}
if (const RecordType *RT = Ty->getAs<RecordType>()) {
SmallVector<const CXXBaseSpecifier *, 1> Bases;
SmallVector<const FieldDecl *, 1> Fields;
const RecordDecl *RD = RT->getDecl();
assert(!RD->hasFlexibleArrayMember() &&
"Cannot expand structure with flexible array.");
if (RD->isUnion()) {
// Unions can be here only in degenerative cases - all the fields are same
// after flattening. Thus we have to use the "largest" field.
const FieldDecl *LargestFD = nullptr;
CharUnits UnionSize = CharUnits::Zero();
for (const auto *FD : RD->fields()) {
// Skip zero length bitfields.
if (FD->isBitField() && FD->getBitWidthValue(Context) == 0)
continue;
assert(!FD->isBitField() &&
"Cannot expand structure with bit-field members.");
CharUnits FieldSize = Context.getTypeSizeInChars(FD->getType());
if (UnionSize < FieldSize) {
UnionSize = FieldSize;
LargestFD = FD;
}
}
if (LargestFD)
Fields.push_back(LargestFD);
} else {
if (const auto *CXXRD = dyn_cast<CXXRecordDecl>(RD)) {
assert(!CXXRD->isDynamicClass() &&
"cannot expand vtable pointers in dynamic classes");
for (const CXXBaseSpecifier &BS : CXXRD->bases())
Bases.push_back(&BS);
}
for (const auto *FD : RD->fields()) {
// Skip zero length bitfields.
if (FD->isBitField() && FD->getBitWidthValue(Context) == 0)
continue;
assert(!FD->isBitField() &&
"Cannot expand structure with bit-field members.");
Fields.push_back(FD);
}
}
return llvm::make_unique<RecordExpansion>(std::move(Bases),
std::move(Fields));
}
if (const ComplexType *CT = Ty->getAs<ComplexType>()) {
return llvm::make_unique<ComplexExpansion>(CT->getElementType());
}
return llvm::make_unique<NoExpansion>();
}
static int getExpansionSize(QualType Ty, const ASTContext &Context) {
auto Exp = getTypeExpansion(Ty, Context);
if (auto CAExp = dyn_cast<ConstantArrayExpansion>(Exp.get())) {
return CAExp->NumElts * getExpansionSize(CAExp->EltTy, Context);
}
if (auto RExp = dyn_cast<RecordExpansion>(Exp.get())) {
int Res = 0;
for (auto BS : RExp->Bases)
Res += getExpansionSize(BS->getType(), Context);
for (auto FD : RExp->Fields)
Res += getExpansionSize(FD->getType(), Context);
return Res;
}
if (isa<ComplexExpansion>(Exp.get()))
return 2;
assert(isa<NoExpansion>(Exp.get()));
return 1;
}
void
CodeGenTypes::getExpandedTypes(QualType Ty,
SmallVectorImpl<llvm::Type *>::iterator &TI) {
auto Exp = getTypeExpansion(Ty, Context);
if (auto CAExp = dyn_cast<ConstantArrayExpansion>(Exp.get())) {
for (int i = 0, n = CAExp->NumElts; i < n; i++) {
getExpandedTypes(CAExp->EltTy, TI);
}
} else if (auto RExp = dyn_cast<RecordExpansion>(Exp.get())) {
for (auto BS : RExp->Bases)
getExpandedTypes(BS->getType(), TI);
for (auto FD : RExp->Fields)
getExpandedTypes(FD->getType(), TI);
} else if (auto CExp = dyn_cast<ComplexExpansion>(Exp.get())) {
llvm::Type *EltTy = ConvertType(CExp->EltTy);
*TI++ = EltTy;
*TI++ = EltTy;
} else {
assert(isa<NoExpansion>(Exp.get()));
*TI++ = ConvertType(Ty);
}
}
void CodeGenFunction::ExpandTypeFromArgs(
QualType Ty, LValue LV, SmallVectorImpl<llvm::Argument *>::iterator &AI) {
assert(LV.isSimple() &&
"Unexpected non-simple lvalue during struct expansion.");
auto Exp = getTypeExpansion(Ty, getContext());
if (auto CAExp = dyn_cast<ConstantArrayExpansion>(Exp.get())) {
for (int i = 0, n = CAExp->NumElts; i < n; i++) {
llvm::Value *EltAddr = Builder.CreateConstGEP2_32(LV.getAddress(), 0, i);
LValue LV = MakeAddrLValue(EltAddr, CAExp->EltTy);
ExpandTypeFromArgs(CAExp->EltTy, LV, AI);
}
} else if (auto RExp = dyn_cast<RecordExpansion>(Exp.get())) {
llvm::Value *This = LV.getAddress();
for (const CXXBaseSpecifier *BS : RExp->Bases) {
// Perform a single step derived-to-base conversion.
llvm::Value *Base =
GetAddressOfBaseClass(This, Ty->getAsCXXRecordDecl(), &BS, &BS + 1,
/*NullCheckValue=*/false, SourceLocation());
LValue SubLV = MakeAddrLValue(Base, BS->getType());
// Recurse onto bases.
ExpandTypeFromArgs(BS->getType(), SubLV, AI);
}
for (auto FD : RExp->Fields) {
// FIXME: What are the right qualifiers here?
LValue SubLV = EmitLValueForField(LV, FD);
ExpandTypeFromArgs(FD->getType(), SubLV, AI);
}
} else if (auto CExp = dyn_cast<ComplexExpansion>(Exp.get())) {
llvm::Value *RealAddr = Builder.CreateStructGEP(LV.getAddress(), 0, "real");
EmitStoreThroughLValue(RValue::get(*AI++),
MakeAddrLValue(RealAddr, CExp->EltTy));
llvm::Value *ImagAddr = Builder.CreateStructGEP(LV.getAddress(), 1, "imag");
EmitStoreThroughLValue(RValue::get(*AI++),
MakeAddrLValue(ImagAddr, CExp->EltTy));
} else {
assert(isa<NoExpansion>(Exp.get()));
EmitStoreThroughLValue(RValue::get(*AI++), LV);
}
}
void CodeGenFunction::ExpandTypeToArgs(
QualType Ty, RValue RV, llvm::FunctionType *IRFuncTy,
SmallVectorImpl<llvm::Value *> &IRCallArgs, unsigned &IRCallArgPos) {
auto Exp = getTypeExpansion(Ty, getContext());
if (auto CAExp = dyn_cast<ConstantArrayExpansion>(Exp.get())) {
llvm::Value *Addr = RV.getAggregateAddr();
for (int i = 0, n = CAExp->NumElts; i < n; i++) {
llvm::Value *EltAddr = Builder.CreateConstGEP2_32(Addr, 0, i);
RValue EltRV =
convertTempToRValue(EltAddr, CAExp->EltTy, SourceLocation());
ExpandTypeToArgs(CAExp->EltTy, EltRV, IRFuncTy, IRCallArgs, IRCallArgPos);
}
} else if (auto RExp = dyn_cast<RecordExpansion>(Exp.get())) {
llvm::Value *This = RV.getAggregateAddr();
for (const CXXBaseSpecifier *BS : RExp->Bases) {
// Perform a single step derived-to-base conversion.
llvm::Value *Base =
GetAddressOfBaseClass(This, Ty->getAsCXXRecordDecl(), &BS, &BS + 1,
/*NullCheckValue=*/false, SourceLocation());
RValue BaseRV = RValue::getAggregate(Base);
// Recurse onto bases.
ExpandTypeToArgs(BS->getType(), BaseRV, IRFuncTy, IRCallArgs,
IRCallArgPos);
}
LValue LV = MakeAddrLValue(This, Ty);
for (auto FD : RExp->Fields) {
RValue FldRV = EmitRValueForField(LV, FD, SourceLocation());
ExpandTypeToArgs(FD->getType(), FldRV, IRFuncTy, IRCallArgs,
IRCallArgPos);
}
} else if (isa<ComplexExpansion>(Exp.get())) {
ComplexPairTy CV = RV.getComplexVal();
IRCallArgs[IRCallArgPos++] = CV.first;
IRCallArgs[IRCallArgPos++] = CV.second;
} else {
assert(isa<NoExpansion>(Exp.get()));
assert(RV.isScalar() &&
"Unexpected non-scalar rvalue during struct expansion.");
// Insert a bitcast as needed.
llvm::Value *V = RV.getScalarVal();
if (IRCallArgPos < IRFuncTy->getNumParams() &&
V->getType() != IRFuncTy->getParamType(IRCallArgPos))
V = Builder.CreateBitCast(V, IRFuncTy->getParamType(IRCallArgPos));
IRCallArgs[IRCallArgPos++] = V;
}
}
/// EnterStructPointerForCoercedAccess - Given a struct pointer that we are
/// accessing some number of bytes out of it, try to gep into the struct to get
/// at its inner goodness. Dive as deep as possible without entering an element
/// with an in-memory size smaller than DstSize.
static llvm::Value *
EnterStructPointerForCoercedAccess(llvm::Value *SrcPtr,
llvm::StructType *SrcSTy,
uint64_t DstSize, CodeGenFunction &CGF) {
// We can't dive into a zero-element struct.
if (SrcSTy->getNumElements() == 0) return SrcPtr;
llvm::Type *FirstElt = SrcSTy->getElementType(0);
// If the first elt is at least as large as what we're looking for, or if the
// first element is the same size as the whole struct, we can enter it. The
// comparison must be made on the store size and not the alloca size. Using
// the alloca size may overstate the size of the load.
uint64_t FirstEltSize =
CGF.CGM.getDataLayout().getTypeStoreSize(FirstElt);
if (FirstEltSize < DstSize &&
FirstEltSize < CGF.CGM.getDataLayout().getTypeStoreSize(SrcSTy))
return SrcPtr;
// GEP into the first element.
SrcPtr = CGF.Builder.CreateConstGEP2_32(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.
///
/// This behaves as if the value were coerced through memory, so on big-endian
/// targets the high bits are preserved in a truncation, while little-endian
/// targets preserve the low bits.
static llvm::Value *CoerceIntOrPtrToIntOrPtr(llvm::Value *Val,
llvm::Type *Ty,
CodeGenFunction &CGF) {
if (Val->getType() == Ty)
return Val;
if (isa<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) {
const llvm::DataLayout &DL = CGF.CGM.getDataLayout();
if (DL.isBigEndian()) {
// Preserve the high bits on big-endian targets.
// That is what memory coercion does.
uint64_t SrcSize = DL.getTypeSizeInBits(Val->getType());
uint64_t DstSize = DL.getTypeSizeInBits(DestIntTy);
if (SrcSize > DstSize) {
Val = CGF.Builder.CreateLShr(Val, SrcSize - DstSize, "coerce.highbits");
Val = CGF.Builder.CreateTrunc(Val, DestIntTy, "coerce.val.ii");
} else {
Val = CGF.Builder.CreateZExt(Val, DestIntTy, "coerce.val.ii");
Val = CGF.Builder.CreateShl(Val, DstSize - SrcSize, "coerce.highbits");
}
} else {
// Little-endian targets preserve the low bits. No shifts required.
Val = CGF.Builder.CreateIntCast(Val, DestIntTy, false, "coerce.val.ii");
}
}
if (isa<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.getDataLayout().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.getDataLayout().getTypeAllocSize(SrcTy);
// If the source and destination are integer or pointer types, just do an
// extension or truncation to the desired type.
if ((isa<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::Type *I8PtrTy = CGF.Builder.getInt8PtrTy();
llvm::Value *Casted = CGF.Builder.CreateBitCast(Tmp, I8PtrTy);
llvm::Value *SrcCasted = CGF.Builder.CreateBitCast(SrcPtr, I8PtrTy);
// FIXME: Use better alignment.
CGF.Builder.CreateMemCpy(Casted, SrcCasted,
llvm::ConstantInt::get(CGF.IntPtrTy, SrcSize),
1, false);
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.getDataLayout().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.getDataLayout().getTypeAllocSize(DstTy);
// If store is legal, just bitcast the src pointer.
if (SrcSize <= DstSize) {
llvm::Value *Casted =
CGF.Builder.CreateBitCast(DstPtr, llvm::PointerType::getUnqual(SrcTy));
// 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::Type *I8PtrTy = CGF.Builder.getInt8PtrTy();
llvm::Value *Casted = CGF.Builder.CreateBitCast(Tmp, I8PtrTy);
llvm::Value *DstCasted = CGF.Builder.CreateBitCast(DstPtr, I8PtrTy);
// FIXME: Use better alignment.
CGF.Builder.CreateMemCpy(DstCasted, Casted,
llvm::ConstantInt::get(CGF.IntPtrTy, DstSize),
1, false);
}
}
namespace {
/// Encapsulates information about the way function arguments from
/// CGFunctionInfo should be passed to actual LLVM IR function.
class ClangToLLVMArgMapping {
static const unsigned InvalidIndex = ~0U;
unsigned InallocaArgNo;
unsigned SRetArgNo;
unsigned TotalIRArgs;
/// Arguments of LLVM IR function corresponding to single Clang argument.
struct IRArgs {
unsigned PaddingArgIndex;
// Argument is expanded to IR arguments at positions
// [FirstArgIndex, FirstArgIndex + NumberOfArgs).
unsigned FirstArgIndex;
unsigned NumberOfArgs;
IRArgs()
: PaddingArgIndex(InvalidIndex), FirstArgIndex(InvalidIndex),
NumberOfArgs(0) {}
};
SmallVector<IRArgs, 8> ArgInfo;
public:
ClangToLLVMArgMapping(const ASTContext &Context, const CGFunctionInfo &FI,
bool OnlyRequiredArgs = false)
: InallocaArgNo(InvalidIndex), SRetArgNo(InvalidIndex), TotalIRArgs(0),
ArgInfo(OnlyRequiredArgs ? FI.getNumRequiredArgs() : FI.arg_size()) {
construct(Context, FI, OnlyRequiredArgs);
}
bool hasInallocaArg() const { return InallocaArgNo != InvalidIndex; }
unsigned getInallocaArgNo() const {
assert(hasInallocaArg());
return InallocaArgNo;
}
bool hasSRetArg() const { return SRetArgNo != InvalidIndex; }
unsigned getSRetArgNo() const {
assert(hasSRetArg());
return SRetArgNo;
}
unsigned totalIRArgs() const { return TotalIRArgs; }
bool hasPaddingArg(unsigned ArgNo) const {
assert(ArgNo < ArgInfo.size());
return ArgInfo[ArgNo].PaddingArgIndex != InvalidIndex;
}
unsigned getPaddingArgNo(unsigned ArgNo) const {
assert(hasPaddingArg(ArgNo));
return ArgInfo[ArgNo].PaddingArgIndex;
}
/// Returns index of first IR argument corresponding to ArgNo, and their
/// quantity.
std::pair<unsigned, unsigned> getIRArgs(unsigned ArgNo) const {
assert(ArgNo < ArgInfo.size());
return std::make_pair(ArgInfo[ArgNo].FirstArgIndex,
ArgInfo[ArgNo].NumberOfArgs);
}
private:
void construct(const ASTContext &Context, const CGFunctionInfo &FI,
bool OnlyRequiredArgs);
};
void ClangToLLVMArgMapping::construct(const ASTContext &Context,
const CGFunctionInfo &FI,
bool OnlyRequiredArgs) {
unsigned IRArgNo = 0;
bool SwapThisWithSRet = false;
const ABIArgInfo &RetAI = FI.getReturnInfo();
if (RetAI.getKind() == ABIArgInfo::Indirect) {
SwapThisWithSRet = RetAI.isSRetAfterThis();
SRetArgNo = SwapThisWithSRet ? 1 : IRArgNo++;
}
unsigned ArgNo = 0;
unsigned NumArgs = OnlyRequiredArgs ? FI.getNumRequiredArgs() : FI.arg_size();
for (CGFunctionInfo::const_arg_iterator I = FI.arg_begin(); ArgNo < NumArgs;
++I, ++ArgNo) {
assert(I != FI.arg_end());
QualType ArgType = I->type;
const ABIArgInfo &AI = I->info;
// Collect data about IR arguments corresponding to Clang argument ArgNo.
auto &IRArgs = ArgInfo[ArgNo];
if (AI.getPaddingType())
IRArgs.PaddingArgIndex = IRArgNo++;
switch (AI.getKind()) {
case ABIArgInfo::Extend:
case ABIArgInfo::Direct: {
// FIXME: handle sseregparm someday...
llvm::StructType *STy = dyn_cast<llvm::StructType>(AI.getCoerceToType());
if (AI.isDirect() && AI.getCanBeFlattened() && STy) {
IRArgs.NumberOfArgs = STy->getNumElements();
} else {
IRArgs.NumberOfArgs = 1;
}
break;
}
case ABIArgInfo::Indirect:
IRArgs.NumberOfArgs = 1;
break;
case ABIArgInfo::Ignore:
case ABIArgInfo::InAlloca:
// ignore and inalloca doesn't have matching LLVM parameters.
IRArgs.NumberOfArgs = 0;
break;
case ABIArgInfo::Expand: {
IRArgs.NumberOfArgs = getExpansionSize(ArgType, Context);
break;
}
}
if (IRArgs.NumberOfArgs > 0) {
IRArgs.FirstArgIndex = IRArgNo;
IRArgNo += IRArgs.NumberOfArgs;
}
// Skip over the sret parameter when it comes second. We already handled it
// above.
if (IRArgNo == 1 && SwapThisWithSRet)
IRArgNo++;
}
assert(ArgNo == ArgInfo.size());
if (FI.usesInAlloca())
InallocaArgNo = IRArgNo++;
TotalIRArgs = IRArgNo;
}
} // namespace
/***/
bool CodeGenModule::ReturnTypeUsesSRet(const CGFunctionInfo &FI) {
return FI.getReturnInfo().isIndirect();
}
bool CodeGenModule::ReturnSlotInterferesWithArgs(const CGFunctionInfo &FI) {
return ReturnTypeUsesSRet(FI) &&
getTargetCodeGenInfo().doesReturnSlotInterfereWithArgs();
}
bool CodeGenModule::ReturnTypeUsesFPRet(QualType ResultType) {
if (const BuiltinType *BT = ResultType->getAs<BuiltinType>()) {
switch (BT->getKind()) {
default:
return false;
case BuiltinType::Float:
return getTarget().useObjCFPRetForRealType(TargetInfo::Float);
case BuiltinType::Double:
return getTarget().useObjCFPRetForRealType(TargetInfo::Double);
case BuiltinType::LongDouble:
return getTarget().useObjCFPRetForRealType(TargetInfo::LongDouble);
}
}
return false;
}
bool CodeGenModule::ReturnTypeUsesFP2Ret(QualType ResultType) {
if (const ComplexType *CT = ResultType->getAs<ComplexType>()) {
if (const BuiltinType *BT = CT->getElementType()->getAs<BuiltinType>()) {
if (BT->getKind() == BuiltinType::LongDouble)
return getTarget().useObjCFP2RetForComplexLongDouble();
}
}
return false;
}
llvm::FunctionType *CodeGenTypes::GetFunctionType(GlobalDecl GD) {
const CGFunctionInfo &FI = arrangeGlobalDeclaration(GD);
return GetFunctionType(FI);
}
llvm::FunctionType *
CodeGenTypes::GetFunctionType(const CGFunctionInfo &FI) {
bool Inserted = FunctionsBeingProcessed.insert(&FI).second;
(void)Inserted;
assert(Inserted && "Recursively being processed?");
llvm::Type *resultType = nullptr;
const ABIArgInfo &retAI = FI.getReturnInfo();
switch (retAI.getKind()) {
case ABIArgInfo::Expand:
llvm_unreachable("Invalid ABI kind for return argument");
case ABIArgInfo::Extend:
case ABIArgInfo::Direct:
resultType = retAI.getCoerceToType();
break;
case ABIArgInfo::InAlloca:
if (retAI.getInAllocaSRet()) {
// sret things on win32 aren't void, they return the sret pointer.
QualType ret = FI.getReturnType();
llvm::Type *ty = ConvertType(ret);
unsigned addressSpace = Context.getTargetAddressSpace(ret);
resultType = llvm::PointerType::get(ty, addressSpace);
} else {
resultType = llvm::Type::getVoidTy(getLLVMContext());
}
break;
case ABIArgInfo::Indirect: {
assert(!retAI.getIndirectAlign() && "Align unused on indirect return.");
resultType = llvm::Type::getVoidTy(getLLVMContext());
break;
}
case ABIArgInfo::Ignore:
resultType = llvm::Type::getVoidTy(getLLVMContext());
break;
}
ClangToLLVMArgMapping IRFunctionArgs(getContext(), FI, true);
SmallVector<llvm::Type*, 8> ArgTypes(IRFunctionArgs.totalIRArgs());
// Add type for sret argument.
if (IRFunctionArgs.hasSRetArg()) {
QualType Ret = FI.getReturnType();
llvm::Type *Ty = ConvertType(Ret);
unsigned AddressSpace = Context.getTargetAddressSpace(Ret);
ArgTypes[IRFunctionArgs.getSRetArgNo()] =
llvm::PointerType::get(Ty, AddressSpace);
}
// Add type for inalloca argument.
if (IRFunctionArgs.hasInallocaArg()) {
auto ArgStruct = FI.getArgStruct();
assert(ArgStruct);
ArgTypes[IRFunctionArgs.getInallocaArgNo()] = ArgStruct->getPointerTo();
}
// Add in all of the required arguments.
unsigned ArgNo = 0;
CGFunctionInfo::const_arg_iterator it = FI.arg_begin(),
ie = it + FI.getNumRequiredArgs();
for (; it != ie; ++it, ++ArgNo) {
const ABIArgInfo &ArgInfo = it->info;
// Insert a padding type to ensure proper alignment.
if (IRFunctionArgs.hasPaddingArg(ArgNo))
ArgTypes[IRFunctionArgs.getPaddingArgNo(ArgNo)] =
ArgInfo.getPaddingType();
unsigned FirstIRArg, NumIRArgs;
std::tie(FirstIRArg, NumIRArgs) = IRFunctionArgs.getIRArgs(ArgNo);
switch (ArgInfo.getKind()) {
case ABIArgInfo::Ignore:
case ABIArgInfo::InAlloca:
assert(NumIRArgs == 0);
break;
case ABIArgInfo::Indirect: {
assert(NumIRArgs == 1);
// indirect arguments are always on the stack, which is addr space #0.
llvm::Type *LTy = ConvertTypeForMem(it->type);
ArgTypes[FirstIRArg] = LTy->getPointerTo();
break;
}
case ABIArgInfo::Extend:
case ABIArgInfo::Direct: {
// Fast-isel and the optimizer generally like scalar values better than
// FCAs, so we flatten them if this is safe to do for this argument.
llvm::Type *argType = ArgInfo.getCoerceToType();
llvm::StructType *st = dyn_cast<llvm::StructType>(argType);
if (st && ArgInfo.isDirect() && ArgInfo.getCanBeFlattened()) {
assert(NumIRArgs == st->getNumElements());
for (unsigned i = 0, e = st->getNumElements(); i != e; ++i)
ArgTypes[FirstIRArg + i] = st->getElementType(i);
} else {
assert(NumIRArgs == 1);
ArgTypes[FirstIRArg] = argType;
}
break;
}
case ABIArgInfo::Expand:
auto ArgTypesIter = ArgTypes.begin() + FirstIRArg;
getExpandedTypes(it->type, ArgTypesIter);
assert(ArgTypesIter == ArgTypes.begin() + FirstIRArg + NumIRArgs);
break;
}
}
bool Erased = FunctionsBeingProcessed.erase(&FI); (void)Erased;
assert(Erased && "Not in set?");
return llvm::FunctionType::get(resultType, ArgTypes, FI.isVariadic());
}
llvm::Type *CodeGenTypes::GetFunctionTypeForVTable(GlobalDecl GD) {
const CXXMethodDecl *MD = cast<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 =
&arrangeCXXStructorDeclaration(MD, getFromDtorType(GD.getDtorType()));
else
Info = &arrangeCXXMethodDeclaration(MD);
return GetFunctionType(*Info);
}
void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI,
const Decl *TargetDecl,
AttributeListType &PAL,
unsigned &CallingConv,
bool AttrOnCallSite) {
llvm::AttrBuilder FuncAttrs;
llvm::AttrBuilder RetAttrs;
CallingConv = FI.getEffectiveCallingConvention();
if (FI.isNoReturn())
FuncAttrs.addAttribute(llvm::Attribute::NoReturn);
// FIXME: handle sseregparm someday...
if (TargetDecl) {
if (TargetDecl->hasAttr<ReturnsTwiceAttr>())
FuncAttrs.addAttribute(llvm::Attribute::ReturnsTwice);
if (TargetDecl->hasAttr<NoThrowAttr>())
FuncAttrs.addAttribute(llvm::Attribute::NoUnwind);
if (TargetDecl->hasAttr<NoReturnAttr>())
FuncAttrs.addAttribute(llvm::Attribute::NoReturn);
if (TargetDecl->hasAttr<NoDuplicateAttr>())
FuncAttrs.addAttribute(llvm::Attribute::NoDuplicate);
if (const FunctionDecl *Fn = dyn_cast<FunctionDecl>(TargetDecl)) {
const FunctionProtoType *FPT = Fn->getType()->getAs<FunctionProtoType>();
if (FPT && FPT->isNothrow(getContext()))
FuncAttrs.addAttribute(llvm::Attribute::NoUnwind);
// Don't use [[noreturn]] or _Noreturn for a call to a virtual function.
// These attributes are not inherited by overloads.
const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Fn);
if (Fn->isNoReturn() && !(AttrOnCallSite && MD && MD->isVirtual()))
FuncAttrs.addAttribute(llvm::Attribute::NoReturn);
}
// 'const' and 'pure' attribute functions are also nounwind.
if (TargetDecl->hasAttr<ConstAttr>()) {
FuncAttrs.addAttribute(llvm::Attribute::ReadNone);
FuncAttrs.addAttribute(llvm::Attribute::NoUnwind);
} else if (TargetDecl->hasAttr<PureAttr>()) {
FuncAttrs.addAttribute(llvm::Attribute::ReadOnly);
FuncAttrs.addAttribute(llvm::Attribute::NoUnwind);
}
if (TargetDecl->hasAttr<MallocAttr>())
RetAttrs.addAttribute(llvm::Attribute::NoAlias);
if (TargetDecl->hasAttr<ReturnsNonNullAttr>())
RetAttrs.addAttribute(llvm::Attribute::NonNull);
}
if (CodeGenOpts.OptimizeSize)
FuncAttrs.addAttribute(llvm::Attribute::OptimizeForSize);
if (CodeGenOpts.OptimizeSize == 2)
FuncAttrs.addAttribute(llvm::Attribute::MinSize);
if (CodeGenOpts.DisableRedZone)
FuncAttrs.addAttribute(llvm::Attribute::NoRedZone);
if (CodeGenOpts.NoImplicitFloat)
FuncAttrs.addAttribute(llvm::Attribute::NoImplicitFloat);
if (CodeGenOpts.EnableSegmentedStacks &&
!(TargetDecl && TargetDecl->hasAttr<NoSplitStackAttr>()))
FuncAttrs.addAttribute("split-stack");
if (AttrOnCallSite) {
// Attributes that should go on the call site only.
if (!CodeGenOpts.SimplifyLibCalls)
FuncAttrs.addAttribute(llvm::Attribute::NoBuiltin);
} else {
// Attributes that should go on the function, but not the call site.
if (!CodeGenOpts.DisableFPElim) {
FuncAttrs.addAttribute("no-frame-pointer-elim", "false");
} else if (CodeGenOpts.OmitLeafFramePointer) {
FuncAttrs.addAttribute("no-frame-pointer-elim", "false");
FuncAttrs.addAttribute("no-frame-pointer-elim-non-leaf");
} else {
FuncAttrs.addAttribute("no-frame-pointer-elim", "true");
FuncAttrs.addAttribute("no-frame-pointer-elim-non-leaf");
}
FuncAttrs.addAttribute("less-precise-fpmad",
llvm::toStringRef(CodeGenOpts.LessPreciseFPMAD));
FuncAttrs.addAttribute("no-infs-fp-math",
llvm::toStringRef(CodeGenOpts.NoInfsFPMath));
FuncAttrs.addAttribute("no-nans-fp-math",
llvm::toStringRef(CodeGenOpts.NoNaNsFPMath));
FuncAttrs.addAttribute("unsafe-fp-math",
llvm::toStringRef(CodeGenOpts.UnsafeFPMath));
FuncAttrs.addAttribute("use-soft-float",
llvm::toStringRef(CodeGenOpts.SoftFloat));
FuncAttrs.addAttribute("stack-protector-buffer-size",
llvm::utostr(CodeGenOpts.SSPBufferSize));
if (!CodeGenOpts.StackRealignment)
FuncAttrs.addAttribute("no-realign-stack");
}
ClangToLLVMArgMapping IRFunctionArgs(getContext(), FI);
QualType RetTy = FI.getReturnType();
const ABIArgInfo &RetAI = FI.getReturnInfo();
switch (RetAI.getKind()) {
case ABIArgInfo::Extend:
if (RetTy->hasSignedIntegerRepresentation())
RetAttrs.addAttribute(llvm::Attribute::SExt);
else if (RetTy->hasUnsignedIntegerRepresentation())
RetAttrs.addAttribute(llvm::Attribute::ZExt);
// FALL THROUGH
case ABIArgInfo::Direct:
if (RetAI.getInReg())
RetAttrs.addAttribute(llvm::Attribute::InReg);
break;
case ABIArgInfo::Ignore:
break;
case ABIArgInfo::InAlloca:
case ABIArgInfo::Indirect: {
// inalloca and sret disable readnone and readonly
FuncAttrs.removeAttribute(llvm::Attribute::ReadOnly)
.removeAttribute(llvm::Attribute::ReadNone);
break;
}
case ABIArgInfo::Expand:
llvm_unreachable("Invalid ABI kind for return argument");
}
if (const auto *RefTy = RetTy->getAs<ReferenceType>()) {
QualType PTy = RefTy->getPointeeType();
if (!PTy->isIncompleteType() && PTy->isConstantSizeType())
RetAttrs.addDereferenceableAttr(getContext().getTypeSizeInChars(PTy)
.getQuantity());
else if (getContext().getTargetAddressSpace(PTy) == 0)
RetAttrs.addAttribute(llvm::Attribute::NonNull);
}
// Attach return attributes.
if (RetAttrs.hasAttributes()) {
PAL.push_back(llvm::AttributeSet::get(
getLLVMContext(), llvm::AttributeSet::ReturnIndex, RetAttrs));
}
// Attach attributes to sret.
if (IRFunctionArgs.hasSRetArg()) {
llvm::AttrBuilder SRETAttrs;
SRETAttrs.addAttribute(llvm::Attribute::StructRet);
if (RetAI.getInReg())
SRETAttrs.addAttribute(llvm::Attribute::InReg);
PAL.push_back(llvm::AttributeSet::get(
getLLVMContext(), IRFunctionArgs.getSRetArgNo() + 1, SRETAttrs));
}
// Attach attributes to inalloca argument.
if (IRFunctionArgs.hasInallocaArg()) {
llvm::AttrBuilder Attrs;
Attrs.addAttribute(llvm::Attribute::InAlloca);
PAL.push_back(llvm::AttributeSet::get(
getLLVMContext(), IRFunctionArgs.getInallocaArgNo() + 1, Attrs));
}
unsigned ArgNo = 0;
for (CGFunctionInfo::const_arg_iterator I = FI.arg_begin(),
E = FI.arg_end();
I != E; ++I, ++ArgNo) {
QualType ParamType = I->type;
const ABIArgInfo &AI = I->info;
llvm::AttrBuilder Attrs;
// Add attribute for padding argument, if necessary.
if (IRFunctionArgs.hasPaddingArg(ArgNo)) {
if (AI.getPaddingInReg())
PAL.push_back(llvm::AttributeSet::get(
getLLVMContext(), IRFunctionArgs.getPaddingArgNo(ArgNo) + 1,
llvm::Attribute::InReg));
}
// 'restrict' -> 'noalias' is done in EmitFunctionProlog when we
// have the corresponding parameter variable. It doesn't make
// sense to do it here because parameters are so messed up.
switch (AI.getKind()) {
case ABIArgInfo::Extend:
if (ParamType->isSignedIntegerOrEnumerationType())
Attrs.addAttribute(llvm::Attribute::SExt);
else if (ParamType->isUnsignedIntegerOrEnumerationType())
Attrs.addAttribute(llvm::Attribute::ZExt);
// FALL THROUGH
case ABIArgInfo::Direct:
if (AI.getInReg())
Attrs.addAttribute(llvm::Attribute::InReg);
break;
case ABIArgInfo::Indirect:
if (AI.getInReg())
Attrs.addAttribute(llvm::Attribute::InReg);
if (AI.getIndirectByVal())
Attrs.addAttribute(llvm::Attribute::ByVal);
Attrs.addAlignmentAttr(AI.getIndirectAlign());
// byval disables readnone and readonly.
FuncAttrs.removeAttribute(llvm::Attribute::ReadOnly)
.removeAttribute(llvm::Attribute::ReadNone);
break;
case ABIArgInfo::Ignore:
case ABIArgInfo::Expand:
continue;
case ABIArgInfo::InAlloca:
// inalloca disables readnone and readonly.
FuncAttrs.removeAttribute(llvm::Attribute::ReadOnly)
.removeAttribute(llvm::Attribute::ReadNone);
continue;
}
if (const auto *RefTy = ParamType->getAs<ReferenceType>()) {
QualType PTy = RefTy->getPointeeType();
if (!PTy->isIncompleteType() && PTy->isConstantSizeType())
Attrs.addDereferenceableAttr(getContext().getTypeSizeInChars(PTy)
.getQuantity());
else if (getContext().getTargetAddressSpace(PTy) == 0)
Attrs.addAttribute(llvm::Attribute::NonNull);
}
if (Attrs.hasAttributes()) {
unsigned FirstIRArg, NumIRArgs;
std::tie(FirstIRArg, NumIRArgs) = IRFunctionArgs.getIRArgs(ArgNo);
for (unsigned i = 0; i < NumIRArgs; i++)
PAL.push_back(llvm::AttributeSet::get(getLLVMContext(),
FirstIRArg + i + 1, Attrs));
}
}
assert(ArgNo == FI.arg_size());
if (FuncAttrs.hasAttributes())
PAL.push_back(llvm::
AttributeSet::get(getLLVMContext(),
llvm::AttributeSet::FunctionIndex,
FuncAttrs));
}
/// An argument came in as a promoted argument; demote it back to its
/// declared type.
static llvm::Value *emitArgumentDemotion(CodeGenFunction &CGF,
const VarDecl *var,
llvm::Value *value) {
llvm::Type *varType = CGF.ConvertType(var->getType());
// This can happen with promotions that actually don't change the
// underlying type, like the enum promotions.
if (value->getType() == varType) return value;
assert((varType->isIntegerTy() || varType->isFloatingPointTy())
&& "unexpected promotion type");
if (isa<llvm::IntegerType>(varType))
return CGF.Builder.CreateTrunc(value, varType, "arg.unpromote");
return CGF.Builder.CreateFPCast(value, varType, "arg.unpromote");
}
/// Returns the attribute (either parameter attribute, or function
/// attribute), which declares argument ArgNo to be non-null.
static const NonNullAttr *getNonNullAttr(const Decl *FD, const ParmVarDecl *PVD,
QualType ArgType, unsigned ArgNo) {
// FIXME: __attribute__((nonnull)) can also be applied to:
// - references to pointers, where the pointee is known to be
// nonnull (apparently a Clang extension)
// - transparent unions containing pointers
// In the former case, LLVM IR cannot represent the constraint. In
// the latter case, we have no guarantee that the transparent union
// is in fact passed as a pointer.
if (!ArgType->isAnyPointerType() && !ArgType->isBlockPointerType())
return nullptr;
// First, check attribute on parameter itself.
if (PVD) {
if (auto ParmNNAttr = PVD->getAttr<NonNullAttr>())
return ParmNNAttr;
}
// Check function attributes.
if (!FD)
return nullptr;
for (const auto *NNAttr : FD->specific_attrs<NonNullAttr>()) {
if (NNAttr->isNonNull(ArgNo))
return NNAttr;
}
return nullptr;
}
void CodeGenFunction::EmitFunctionProlog(const CGFunctionInfo &FI,
llvm::Function *Fn,
const FunctionArgList &Args) {
if (CurCodeDecl && CurCodeDecl->hasAttr<NakedAttr>())
// Naked functions don't have prologues.
return;
// If this is an implicit-return-zero function, go ahead and
// initialize the return value. TODO: it might be nice to have
// a more general mechanism for this that didn't require synthesized
// return statements.
if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(CurCodeDecl)) {
if (FD->hasImplicitReturnZero()) {
QualType RetTy = FD->getReturnType().getUnqualifiedType();
llvm::Type* LLVMTy = CGM.getTypes().ConvertType(RetTy);
llvm::Constant* Zero = llvm::Constant::getNullValue(LLVMTy);
Builder.CreateStore(Zero, ReturnValue);
}
}
// FIXME: We no longer need the types from FunctionArgList; lift up and
// simplify.
ClangToLLVMArgMapping IRFunctionArgs(CGM.getContext(), FI);
// Flattened function arguments.
SmallVector<llvm::Argument *, 16> FnArgs;
FnArgs.reserve(IRFunctionArgs.totalIRArgs());
for (auto &Arg : Fn->args()) {
FnArgs.push_back(&Arg);
}
assert(FnArgs.size() == IRFunctionArgs.totalIRArgs());
// If we're using inalloca, all the memory arguments are GEPs off of the last
// parameter, which is a pointer to the complete memory area.
llvm::Value *ArgStruct = nullptr;
if (IRFunctionArgs.hasInallocaArg()) {
ArgStruct = FnArgs[IRFunctionArgs.getInallocaArgNo()];
assert(ArgStruct->getType() == FI.getArgStruct()->getPointerTo());
}
// Name the struct return parameter.
if (IRFunctionArgs.hasSRetArg()) {
auto AI = FnArgs[IRFunctionArgs.getSRetArgNo()];
AI->setName("agg.result");
AI->addAttr(llvm::AttributeSet::get(getLLVMContext(), AI->getArgNo() + 1,
llvm::Attribute::NoAlias));
}
// Track if we received the parameter as a pointer (indirect, byval, or
// inalloca). If already have a pointer, EmitParmDecl doesn't need to copy it
// into a local alloca for us.
enum ValOrPointer { HaveValue = 0, HavePointer = 1 };
typedef llvm::PointerIntPair<llvm::Value *, 1> ValueAndIsPtr;
SmallVector<ValueAndIsPtr, 16> ArgVals;
ArgVals.reserve(Args.size());
// Create a pointer value for every parameter declaration. This usually
// entails copying one or more LLVM IR arguments into an alloca. Don't push
// any cleanups or do anything that might unwind. We do that separately, so
// we can push the cleanups in the correct order for the ABI.
assert(FI.arg_size() == Args.size() &&
"Mismatch between function signature & arguments.");
unsigned ArgNo = 0;
CGFunctionInfo::const_arg_iterator info_it = FI.arg_begin();
for (FunctionArgList::const_iterator i = Args.begin(), e = Args.end();
i != e; ++i, ++info_it, ++ArgNo) {
const VarDecl *Arg = *i;
QualType Ty = info_it->type;
const ABIArgInfo &ArgI = info_it->info;
bool isPromoted =
isa<ParmVarDecl>(Arg) && cast<ParmVarDecl>(Arg)->isKNRPromoted();
unsigned FirstIRArg, NumIRArgs;
std::tie(FirstIRArg, NumIRArgs) = IRFunctionArgs.getIRArgs(ArgNo);
switch (ArgI.getKind()) {
case ABIArgInfo::InAlloca: {
assert(NumIRArgs == 0);
llvm::Value *V = Builder.CreateStructGEP(
ArgStruct, ArgI.getInAllocaFieldIndex(), Arg->getName());
ArgVals.push_back(ValueAndIsPtr(V, HavePointer));
break;
}
case ABIArgInfo::Indirect: {
assert(NumIRArgs == 1);
llvm::Value *V = FnArgs[FirstIRArg];
if (!hasScalarEvaluationKind(Ty)) {
// Aggregates and complex variables are accessed by reference. All we
// need to do is realign the value, if requested
if (ArgI.getIndirectRealign()) {
llvm::Value *AlignedTemp = CreateMemTemp(Ty, "coerce");
// Copy from the incoming argument pointer to the temporary with the
// appropriate alignment.
//
// FIXME: We should have a common utility for generating an aggregate
// copy.
llvm::Type *I8PtrTy = Builder.getInt8PtrTy();
CharUnits Size = getContext().getTypeSizeInChars(Ty);
llvm::Value *Dst = Builder.CreateBitCast(AlignedTemp, I8PtrTy);
llvm::Value *Src = Builder.CreateBitCast(V, I8PtrTy);
Builder.CreateMemCpy(Dst,
Src,
llvm::ConstantInt::get(IntPtrTy,
Size.getQuantity()),
ArgI.getIndirectAlign(),
false);
V = AlignedTemp;
}
ArgVals.push_back(ValueAndIsPtr(V, HavePointer));
} else {
// Load scalar value from indirect argument.
CharUnits Alignment = getContext().getTypeAlignInChars(Ty);
V = EmitLoadOfScalar(V, false, Alignment.getQuantity(), Ty,
Arg->getLocStart());
if (isPromoted)
V = emitArgumentDemotion(*this, Arg, V);
ArgVals.push_back(ValueAndIsPtr(V, HaveValue));
}
break;
}
case ABIArgInfo::Extend:
case ABIArgInfo::Direct: {
// If we have the trivial case, handle it with no muss and fuss.
if (!isa<llvm::StructType>(ArgI.getCoerceToType()) &&
ArgI.getCoerceToType() == ConvertType(Ty) &&
ArgI.getDirectOffset() == 0) {
assert(NumIRArgs == 1);
auto AI = FnArgs[FirstIRArg];
llvm::Value *V = AI;
if (const ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(Arg)) {
if (getNonNullAttr(CurCodeDecl, PVD, PVD->getType(),
PVD->getFunctionScopeIndex()))
AI->addAttr(llvm::AttributeSet::get(getLLVMContext(),
AI->getArgNo() + 1,
llvm::Attribute::NonNull));
QualType OTy = PVD->getOriginalType();
if (const auto *ArrTy =
getContext().getAsConstantArrayType(OTy)) {
// A C99 array parameter declaration with the static keyword also
// indicates dereferenceability, and if the size is constant we can
// use the dereferenceable attribute (which requires the size in
// bytes).
if (ArrTy->getSizeModifier() == ArrayType::Static) {
QualType ETy = ArrTy->getElementType();
uint64_t ArrSize = ArrTy->getSize().getZExtValue();
if (!ETy->isIncompleteType() && ETy->isConstantSizeType() &&
ArrSize) {
llvm::AttrBuilder Attrs;
Attrs.addDereferenceableAttr(
getContext().getTypeSizeInChars(ETy).getQuantity()*ArrSize);
AI->addAttr(llvm::AttributeSet::get(getLLVMContext(),
AI->getArgNo() + 1, Attrs));
} else if (getContext().getTargetAddressSpace(ETy) == 0) {
AI->addAttr(llvm::AttributeSet::get(getLLVMContext(),
AI->getArgNo() + 1,
llvm::Attribute::NonNull));
}
}
} else if (const auto *ArrTy =
getContext().getAsVariableArrayType(OTy)) {
// For C99 VLAs with the static keyword, we don't know the size so
// we can't use the dereferenceable attribute, but in addrspace(0)
// we know that it must be nonnull.
if (ArrTy->getSizeModifier() == VariableArrayType::Static &&
!getContext().getTargetAddressSpace(ArrTy->getElementType()))
AI->addAttr(llvm::AttributeSet::get(getLLVMContext(),
AI->getArgNo() + 1,
llvm::Attribute::NonNull));
}
const auto *AVAttr = PVD->getAttr<AlignValueAttr>();
if (!AVAttr)
if (const auto *TOTy = dyn_cast<TypedefType>(OTy))
AVAttr = TOTy->getDecl()->getAttr<AlignValueAttr>();
if (AVAttr) {
llvm::Value *AlignmentValue =
EmitScalarExpr(AVAttr->getAlignment());
llvm::ConstantInt *AlignmentCI =
cast<llvm::ConstantInt>(AlignmentValue);
unsigned Alignment =
std::min((unsigned) AlignmentCI->getZExtValue(),
+llvm::Value::MaximumAlignment);
llvm::AttrBuilder Attrs;
Attrs.addAlignmentAttr(Alignment);
AI->addAttr(llvm::AttributeSet::get(getLLVMContext(),
AI->getArgNo() + 1, Attrs));
}
}
if (Arg->getType().isRestrictQualified())
AI->addAttr(llvm::AttributeSet::get(getLLVMContext(),
AI->getArgNo() + 1,
llvm::Attribute::NoAlias));
// Ensure the argument is the correct type.
if (V->getType() != ArgI.getCoerceToType())
V = Builder.CreateBitCast(V, ArgI.getCoerceToType());
if (isPromoted)
V = emitArgumentDemotion(*this, Arg, V);
if (const CXXMethodDecl *MD =
dyn_cast_or_null<CXXMethodDecl>(CurCodeDecl)) {
if (MD->isVirtual() && Arg == CXXABIThisDecl)
V = CGM.getCXXABI().
adjustThisParameterInVirtualFunctionPrologue(*this, CurGD, V);
}
// Because of merging of function types from multiple decls it is
// possible for the type of an argument to not match the corresponding
// type in the function type. Since we are codegening the callee
// in here, add a cast to the argument type.
llvm::Type *LTy = ConvertType(Arg->getType());
if (V->getType() != LTy)
V = Builder.CreateBitCast(V, LTy);
ArgVals.push_back(ValueAndIsPtr(V, HaveValue));
break;
}
llvm::AllocaInst *Alloca = CreateMemTemp(Ty, Arg->getName());
// The alignment we need to use is the max of the requested alignment for
// the argument plus the alignment required by our access code below.
unsigned AlignmentToUse =
CGM.getDataLayout().getABITypeAlignment(ArgI.getCoerceToType());
AlignmentToUse = std::max(AlignmentToUse,
(unsigned)getContext().getDeclAlign(Arg).getQuantity());
Alloca->setAlignment(AlignmentToUse);
llvm::Value *V = Alloca;
llvm::Value *Ptr = V; // Pointer to store into.
// 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()));
}
// Fast-isel and the optimizer generally like scalar values better than
// FCAs, so we flatten them if this is safe to do for this argument.
llvm::StructType *STy = dyn_cast<llvm::StructType>(ArgI.getCoerceToType());
if (ArgI.isDirect() && ArgI.getCanBeFlattened() && STy &&
STy->getNumElements() > 1) {
uint64_t SrcSize = CGM.getDataLayout().getTypeAllocSize(STy);
llvm::Type *DstTy =
cast<llvm::PointerType>(Ptr->getType())->getElementType();
uint64_t DstSize = CGM.getDataLayout().getTypeAllocSize(DstTy);
if (SrcSize <= DstSize) {
Ptr = Builder.CreateBitCast(Ptr, llvm::PointerType::getUnqual(STy));
assert(STy->getNumElements() == NumIRArgs);
for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
auto AI = FnArgs[FirstIRArg + i];
AI->setName(Arg->getName() + ".coerce" + Twine(i));
llvm::Value *EltPtr = Builder.CreateConstGEP2_32(Ptr, 0, i);
Builder.CreateStore(AI, EltPtr);
}
} else {
llvm::AllocaInst *TempAlloca =
CreateTempAlloca(ArgI.getCoerceToType(), "coerce");
TempAlloca->setAlignment(AlignmentToUse);
llvm::Value *TempV = TempAlloca;
assert(STy->getNumElements() == NumIRArgs);
for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
auto AI = FnArgs[FirstIRArg + i];
AI->setName(Arg->getName() + ".coerce" + Twine(i));
llvm::Value *EltPtr = Builder.CreateConstGEP2_32(TempV, 0, i);
Builder.CreateStore(AI, EltPtr);
}
Builder.CreateMemCpy(Ptr, TempV, DstSize, AlignmentToUse);
}
} else {
// Simple case, just do a coerced store of the argument into the alloca.
assert(NumIRArgs == 1);
auto AI = FnArgs[FirstIRArg];
AI->setName(Arg->getName() + ".coerce");
CreateCoercedStore(AI, Ptr, /*DestIsVolatile=*/false, *this);
}
// Match to what EmitParmDecl is expecting for this type.
if (CodeGenFunction::hasScalarEvaluationKind(Ty)) {
V = EmitLoadOfScalar(V, false, AlignmentToUse, Ty, Arg->getLocStart());
if (isPromoted)
V = emitArgumentDemotion(*this, Arg, V);
ArgVals.push_back(ValueAndIsPtr(V, HaveValue));
} else {
ArgVals.push_back(ValueAndIsPtr(V, HavePointer));
}
break;
}
case ABIArgInfo::Expand: {
// If this structure was expanded into multiple arguments then
// we need to create a temporary and reconstruct it from the
// arguments.
llvm::AllocaInst *Alloca = CreateMemTemp(Ty);
CharUnits Align = getContext().getDeclAlign(Arg);
Alloca->setAlignment(Align.getQuantity());
LValue LV = MakeAddrLValue(Alloca, Ty, Align);
ArgVals.push_back(ValueAndIsPtr(Alloca, HavePointer));
auto FnArgIter = FnArgs.begin() + FirstIRArg;
ExpandTypeFromArgs(Ty, LV, FnArgIter);
assert(FnArgIter == FnArgs.begin() + FirstIRArg + NumIRArgs);
for (unsigned i = 0, e = NumIRArgs; i != e; ++i) {
auto AI = FnArgs[FirstIRArg + i];
AI->setName(Arg->getName() + "." + Twine(i));
}
break;
}
case ABIArgInfo::Ignore:
assert(NumIRArgs == 0);
// Initialize the local variable appropriately.
if (!hasScalarEvaluationKind(Ty)) {
ArgVals.push_back(ValueAndIsPtr(CreateMemTemp(Ty), HavePointer));
} else {
llvm::Value *U = llvm::UndefValue::get(ConvertType(Arg->getType()));
ArgVals.push_back(ValueAndIsPtr(U, HaveValue));
}
break;
}
}
if (getTarget().getCXXABI().areArgsDestroyedLeftToRightInCallee()) {
for (int I = Args.size() - 1; I >= 0; --I)
EmitParmDecl(*Args[I], ArgVals[I].getPointer(), ArgVals[I].getInt(),
I + 1);
} else {
for (unsigned I = 0, E = Args.size(); I != E; ++I)
EmitParmDecl(*Args[I], ArgVals[I].getPointer(), ArgVals[I].getInt(),
I + 1);
}
}
static void eraseUnusedBitCasts(llvm::Instruction *insn) {
while (insn->use_empty()) {
llvm::BitCastInst *bitcast = dyn_cast<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 nullptr;
if (&BB->back() != result) return nullptr;
llvm::Type *resultType = result->getType();
// result is in a BasicBlock and is therefore an Instruction.
llvm::Instruction *generator = cast<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 nullptr;
insnsToKill.push_back(bitcast);
}
// Look for:
// %generator = call i8* @objc_retain(i8* %originalResult)
// or
// %generator = call i8* @objc_retainAutoreleasedReturnValue(i8* %originalResult)
llvm::CallInst *call = dyn_cast<llvm::CallInst>(generator);
if (!call) return nullptr;
bool doRetainAutorelease;
if (call->getCalledValue() == CGF.CGM.getARCEntrypoints().objc_retain) {
doRetainAutorelease = true;
} else if (call->getCalledValue() == CGF.CGM.getARCEntrypoints()
.objc_retainAutoreleasedReturnValue) {
doRetainAutorelease = false;
// If we emitted an assembly marker for this call (and the
// ARCEntrypoints field should have been set if so), go looking
// for that call. If we can't find it, we can't do this
// optimization. But it should always be the immediately previous
// instruction, unless we needed bitcasts around the call.
if (CGF.CGM.getARCEntrypoints().retainAutoreleasedReturnValueMarker) {
llvm::Instruction *prev = call->getPrevNode();
assert(prev);
if (isa<llvm::BitCastInst>(prev)) {
prev = prev->getPrevNode();
assert(prev);
}
assert(isa<llvm::CallInst>(prev));
assert(cast<llvm::CallInst>(prev)->getCalledValue() ==
CGF.CGM.getARCEntrypoints().retainAutoreleasedReturnValueMarker);
insnsToKill.push_back(prev);
}
} else {
return nullptr;
}
result = call->getArgOperand(0);
insnsToKill.push_back(call);
// Keep killing bitcasts, for sanity. Note that we no longer care
// about precise ordering as long as there's exactly one use.
while (llvm::BitCastInst *bitcast = dyn_cast<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_or_null<ObjCMethodDecl>(CGF.CurCodeDecl);
if (!method) return nullptr;
const VarDecl *self = method->getSelfDecl();
if (!self->getType().isConstQualified()) return nullptr;
// Look for a retain call.
llvm::CallInst *retainCall =
dyn_cast<llvm::CallInst>(result->stripPointerCasts());
if (!retainCall ||
retainCall->getCalledValue() != CGF.CGM.getARCEntrypoints().objc_retain)
return nullptr;
// Look for an ordinary load of 'self'.
llvm::Value *retainedValue = retainCall->getArgOperand(0);
llvm::LoadInst *load =
dyn_cast<llvm::LoadInst>(retainedValue->stripPointerCasts());
if (!load || load->isAtomic() || load->isVolatile() ||
load->getPointerOperand() != CGF.GetAddrOfLocalVar(self))
return nullptr;
// Okay! Burn it all down. This relies for correctness on the
// assumption that the retain is emitted as part of the return and
// that thereafter everything is used "linearly".
llvm::Type *resultType = result->getType();
eraseUnusedBitCasts(cast<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 nullptr;
llvm::StoreInst *store = dyn_cast<llvm::StoreInst>(&IP->back());
if (!store) return nullptr;
if (store->getPointerOperand() != CGF.ReturnValue) return nullptr;
assert(!store->isAtomic() && !store->isVolatile()); // see below
return store;
}
llvm::StoreInst *store =
dyn_cast<llvm::StoreInst>(CGF.ReturnValue->user_back());
if (!store) return nullptr;
// These aren't actually possible for non-coerced returns, and we
// only care about non-coerced returns on this code path.
assert(!store->isAtomic() && !store->isVolatile());
// Now do a first-and-dirty dominance check: just walk up the
// single-predecessors chain from the current insertion point.
llvm::BasicBlock *StoreBB = store->getParent();
llvm::BasicBlock *IP = CGF.Builder.GetInsertBlock();
while (IP != StoreBB) {
if (!(IP = IP->getSinglePredecessor()))
return nullptr;
}
// Okay, the store's basic block dominates the insertion point; we
// can do our thing.
return store;
}
void CodeGenFunction::EmitFunctionEpilog(const CGFunctionInfo &FI,
bool EmitRetDbgLoc,
SourceLocation EndLoc) {
if (CurCodeDecl && CurCodeDecl->hasAttr<NakedAttr>()) {
// Naked functions don't have epilogues.
Builder.CreateUnreachable();
return;
}
// Functions with no result always return void.
if (!ReturnValue) {
Builder.CreateRetVoid();
return;
}
llvm::DebugLoc RetDbgLoc;
llvm::Value *RV = nullptr;
QualType RetTy = FI.getReturnType();
const ABIArgInfo &RetAI = FI.getReturnInfo();
switch (RetAI.getKind()) {
case ABIArgInfo::InAlloca:
// Aggregrates get evaluated directly into the destination. Sometimes we
// need to return the sret value in a register, though.
assert(hasAggregateEvaluationKind(RetTy));
if (RetAI.getInAllocaSRet()) {
llvm::Function::arg_iterator EI = CurFn->arg_end();
--EI;
llvm::Value *ArgStruct = EI;
llvm::Value *SRet =
Builder.CreateStructGEP(ArgStruct, RetAI.getInAllocaFieldIndex());
RV = Builder.CreateLoad(SRet, "sret");
}
break;
case ABIArgInfo::Indirect: {
auto AI = CurFn->arg_begin();
if (RetAI.isSRetAfterThis())
++AI;
switch (getEvaluationKind(RetTy)) {
case TEK_Complex: {
ComplexPairTy RT =
EmitLoadOfComplex(MakeNaturalAlignAddrLValue(ReturnValue, RetTy),
EndLoc);
EmitStoreOfComplex(RT, MakeNaturalAlignAddrLValue(AI, RetTy),
/*isInit*/ true);
break;
}
case TEK_Aggregate:
// Do nothing; aggregrates get evaluated directly into the destination.
break;
case TEK_Scalar:
EmitStoreOfScalar(Builder.CreateLoad(ReturnValue),
MakeNaturalAlignAddrLValue(AI, RetTy),
/*isInit*/ true);
break;
}
break;
}
case ABIArgInfo::Extend:
case ABIArgInfo::Direct:
if (RetAI.getCoerceToType() == ConvertType(RetTy) &&
RetAI.getDirectOffset() == 0) {
// The internal return value temp always will have pointer-to-return-type
// type, just do a load.
// If there is a dominating store to ReturnValue, we can elide
// the load, zap the store, and usually zap the alloca.
if (llvm::StoreInst *SI = findDominatingStoreToReturnValue(*this)) {
// Reuse the debug location from the store unless there is
// cleanup code to be emitted between the store and return
// instruction.
if (EmitRetDbgLoc && !AutoreleaseResult)
RetDbgLoc = SI->getDebugLoc();
// Get the stored value and nuke the now-dead store.
RV = SI->getValueOperand();
SI->eraseFromParent();
// If that was the only use of the return value, nuke it as well now.
if (ReturnValue->use_empty() && isa<llvm::AllocaInst>(ReturnValue)) {
cast<llvm::AllocaInst>(ReturnValue)->eraseFromParent();
ReturnValue = nullptr;
}
// 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;
if (RV) {
if (SanOpts.has(SanitizerKind::ReturnsNonnullAttribute)) {
if (auto RetNNAttr = CurGD.getDecl()->getAttr<ReturnsNonNullAttr>()) {
SanitizerScope SanScope(this);
llvm::Value *Cond = Builder.CreateICmpNE(
RV, llvm::Constant::getNullValue(RV->getType()));
llvm::Constant *StaticData[] = {
EmitCheckSourceLocation(EndLoc),
EmitCheckSourceLocation(RetNNAttr->getLocation()),
};
EmitCheck(std::make_pair(Cond, SanitizerKind::ReturnsNonnullAttribute),
"nonnull_return", StaticData, None);
}
}
Ret = Builder.CreateRet(RV);
} else {
Ret = Builder.CreateRetVoid();
}
if (!RetDbgLoc.isUnknown())
Ret->setDebugLoc(RetDbgLoc);
}
static bool isInAllocaArgument(CGCXXABI &ABI, QualType type) {
const CXXRecordDecl *RD = type->getAsCXXRecordDecl();
return RD && ABI.getRecordArgABI(RD) == CGCXXABI::RAA_DirectInMemory;
}
static AggValueSlot createPlaceholderSlot(CodeGenFunction &CGF, QualType Ty) {
// FIXME: Generate IR in one pass, rather than going back and fixing up these
// placeholders.
llvm::Type *IRTy = CGF.ConvertTypeForMem(Ty);
llvm::Value *Placeholder =
llvm::UndefValue::get(IRTy->getPointerTo()->getPointerTo());
Placeholder = CGF.Builder.CreateLoad(Placeholder);
return AggValueSlot::forAddr(Placeholder, CharUnits::Zero(),
Ty.getQualifiers(),
AggValueSlot::IsNotDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
AggValueSlot::IsNotAliased);
}
void CodeGenFunction::EmitDelegateCallArg(CallArgList &args,
const VarDecl *param,
SourceLocation loc) {
// StartFunction converted the ABI-lowered parameter(s) into a
// local alloca. We need to turn that into an r-value suitable
// for EmitCall.
llvm::Value *local = GetAddrOfLocalVar(param);
QualType type = param->getType();
// For the most part, we just need to load the alloca, except:
// 1) aggregate r-values are actually pointers to temporaries, and
// 2) references to non-scalars are pointers directly to the aggregate.
// I don't know why references to scalars are different here.
if (const ReferenceType *ref = type->getAs<ReferenceType>()) {
if (!hasScalarEvaluationKind(ref->getPointeeType()))
return args.add(RValue::getAggregate(local), type);
// Locals which are references to scalars are represented
// with allocas holding the pointer.
return args.add(RValue::get(Builder.CreateLoad(local)), type);
}
assert(!isInAllocaArgument(CGM.getCXXABI(), type) &&
"cannot emit delegate call arguments for inalloca arguments!");
args.add(convertTempToRValue(local, type, loc), type);
}
static bool isProvablyNull(llvm::Value *addr) {
return isa<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) {
const LValue &srcLV = writeback.Source;
llvm::Value *srcAddr = srcLV.getAddress();
assert(!isProvablyNull(srcAddr) &&
"shouldn't have writeback for provably null argument");
llvm::BasicBlock *contBB = nullptr;
// If the argument wasn't provably non-null, we need to null check
// before doing the store.
bool provablyNonNull = isProvablyNonNull(srcAddr);
if (!provablyNonNull) {
llvm::BasicBlock *writebackBB = CGF.createBasicBlock("icr.writeback");
contBB = CGF.createBasicBlock("icr.done");
llvm::Value *isNull = CGF.Builder.CreateIsNull(srcAddr, "icr.isnull");
CGF.Builder.CreateCondBr(isNull, contBB, writebackBB);
CGF.EmitBlock(writebackBB);
}
// Load the value to writeback.
llvm::Value *value = CGF.Builder.CreateLoad(writeback.Temporary);
// Cast it back, in case we're writing an id to a Foo* or something.
value = CGF.Builder.CreateBitCast(value,
cast<llvm::PointerType>(srcAddr->getType())->getElementType(),
"icr.writeback-cast");
// Perform the writeback.
// If we have a "to use" value, it's something we need to emit a use
// of. This has to be carefully threaded in: if it's done after the
// release it's potentially undefined behavior (and the optimizer
// will ignore it), and if it happens before the retain then the
// optimizer could move the release there.
if (writeback.ToUse) {
assert(srcLV.getObjCLifetime() == Qualifiers::OCL_Strong);
// Retain the new value. No need to block-copy here: the block's
// being passed up the stack.
value = CGF.EmitARCRetainNonBlock(value);
// Emit the intrinsic use here.
CGF.EmitARCIntrinsicUse(writeback.ToUse);
// Load the old value (primitively).
llvm::Value *oldValue = CGF.EmitLoadOfScalar(srcLV, SourceLocation());
// Put the new value in place (primitively).
CGF.EmitStoreOfScalar(value, srcLV, /*init*/ false);
// Release the old value.
CGF.EmitARCRelease(oldValue, srcLV.isARCPreciseLifetime());
// Otherwise, we can just do a normal lvalue store.
} else {
CGF.EmitStoreThroughLValue(RValue::get(value), srcLV);
}
// Jump to the continuation block.
if (!provablyNonNull)
CGF.EmitBlock(contBB);
}
static void emitWritebacks(CodeGenFunction &CGF,
const CallArgList &args) {
for (const auto &I : args.writebacks())
emitWriteback(CGF, I);
}
static void deactivateArgCleanupsBeforeCall(CodeGenFunction &CGF,
const CallArgList &CallArgs) {
assert(CGF.getTarget().getCXXABI().areArgsDestroyedLeftToRightInCallee());
ArrayRef<CallArgList::CallArgCleanup> Cleanups =
CallArgs.getCleanupsToDeactivate();
// Iterate in reverse to increase the likelihood of popping the cleanup.
for (ArrayRef<CallArgList::CallArgCleanup>::reverse_iterator
I = Cleanups.rbegin(), E = Cleanups.rend(); I != E; ++I) {
CGF.DeactivateCleanupBlock(I->Cleanup, I->IsActiveIP);
I->IsActiveIP->eraseFromParent();
}
}
static const Expr *maybeGetUnaryAddrOfOperand(const Expr *E) {
if (const UnaryOperator *uop = dyn_cast<UnaryOperator>(E->IgnoreParens()))
if (uop->getOpcode() == UO_AddrOf)
return uop->getSubExpr();
return nullptr;
}
/// Emit an argument that's being passed call-by-writeback. That is,
/// we are passing the address of
static void emitWritebackArg(CodeGenFunction &CGF, CallArgList &args,
const ObjCIndirectCopyRestoreExpr *CRE) {
LValue srcLV;
// Make an optimistic effort to emit the address as an l-value.
// This can fail if the the argument expression is more complicated.
if (const Expr *lvExpr = maybeGetUnaryAddrOfOperand(CRE->getSubExpr())) {
srcLV = CGF.EmitLValue(lvExpr);
// Otherwise, just emit it as a scalar.
} else {
llvm::Value *srcAddr = CGF.EmitScalarExpr(CRE->getSubExpr());
QualType srcAddrType =
CRE->getSubExpr()->getType()->castAs<PointerType>()->getPointeeType();
srcLV = CGF.MakeNaturalAlignAddrLValue(srcAddr, srcAddrType);
}
llvm::Value *srcAddr = srcLV.getAddress();
// The dest and src types don't necessarily match in LLVM terms
// because of the crazy ObjC compatibility rules.
llvm::PointerType *destType =
cast<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;
}
// Create the temporary.
llvm::Value *temp = CGF.CreateTempAlloca(destType->getElementType(),
"icr.temp");
// Loading an l-value can introduce a cleanup if the l-value is __weak,
// and that cleanup will be conditional if we can't prove that the l-value
// isn't null, so we need to register a dominating point so that the cleanups
// system will make valid IR.
CodeGenFunction::ConditionalEvaluation condEval(CGF);
// Zero-initialize it if we're not doing a copy-initialization.
bool shouldCopy = CRE->shouldCopy();
if (!shouldCopy) {
llvm::Value *null =
llvm::ConstantPointerNull::get(
cast<llvm::PointerType>(destType->getElementType()));
CGF.Builder.CreateStore(null, temp);
}
llvm::BasicBlock *contBB = nullptr;
llvm::BasicBlock *originBB = nullptr;
// If the address is *not* known to be non-null, we need to switch.
llvm::Value *finalArgument;
bool provablyNonNull = isProvablyNonNull(srcAddr);
if (provablyNonNull) {
finalArgument = temp;
} else {
llvm::Value *isNull = CGF.Builder.CreateIsNull(srcAddr, "icr.isnull");
finalArgument = CGF.Builder.CreateSelect(isNull,
llvm::ConstantPointerNull::get(destType),
temp, "icr.argument");
// If we need to copy, then the load has to be conditional, which
// means we need control flow.
if (shouldCopy) {
originBB = CGF.Builder.GetInsertBlock();
contBB = CGF.createBasicBlock("icr.cont");
llvm::BasicBlock *copyBB = CGF.createBasicBlock("icr.copy");
CGF.Builder.CreateCondBr(isNull, contBB, copyBB);
CGF.EmitBlock(copyBB);
condEval.begin(CGF);
}
}
llvm::Value *valueToUse = nullptr;
// Perform a copy if necessary.
if (shouldCopy) {
RValue srcRV = CGF.EmitLoadOfLValue(srcLV, SourceLocation());
assert(srcRV.isScalar());
llvm::Value *src = srcRV.getScalarVal();
src = CGF.Builder.CreateBitCast(src, destType->getElementType(),
"icr.cast");
// Use an ordinary store, not a store-to-lvalue.
CGF.Builder.CreateStore(src, temp);
// If optimization is enabled, and the value was held in a
// __strong variable, we need to tell the optimizer that this
// value has to stay alive until we're doing the store back.
// This is because the temporary is effectively unretained,
// and so otherwise we can violate the high-level semantics.
if (CGF.CGM.getCodeGenOpts().OptimizationLevel != 0 &&
srcLV.getObjCLifetime() == Qualifiers::OCL_Strong) {
valueToUse = src;
}
}
// Finish the control flow if we needed it.
if (shouldCopy && !provablyNonNull) {
llvm::BasicBlock *copyBB = CGF.Builder.GetInsertBlock();
CGF.EmitBlock(contBB);
// Make a phi for the value to intrinsically use.
if (valueToUse) {
llvm::PHINode *phiToUse = CGF.Builder.CreatePHI(valueToUse->getType(), 2,
"icr.to-use");
phiToUse->addIncoming(valueToUse, copyBB);
phiToUse->addIncoming(llvm::UndefValue::get(valueToUse->getType()),
originBB);
valueToUse = phiToUse;
}
condEval.end(CGF);
}
args.addWriteback(srcLV, temp, valueToUse);
args.add(RValue::get(finalArgument), CRE->getType());
}
void CallArgList::allocateArgumentMemory(CodeGenFunction &CGF) {
assert(!StackBase && !StackCleanup.isValid());
// Save the stack.
llvm::Function *F = CGF.CGM.getIntrinsic(llvm::Intrinsic::stacksave);
StackBase = CGF.Builder.CreateCall(F, "inalloca.save");
// Control gets really tied up in landing pads, so we have to spill the
// stacksave to an alloca to avoid violating SSA form.
// TODO: This is dead if we never emit the cleanup. We should create the
// alloca and store lazily on the first cleanup emission.
StackBaseMem = CGF.CreateTempAlloca(CGF.Int8PtrTy, "inalloca.spmem");
CGF.Builder.CreateStore(StackBase, StackBaseMem);
CGF.pushStackRestore(EHCleanup, StackBaseMem);
StackCleanup = CGF.EHStack.getInnermostEHScope();
assert(StackCleanup.isValid());
}
void CallArgList::freeArgumentMemory(CodeGenFunction &CGF) const {
if (StackBase) {
CGF.DeactivateCleanupBlock(StackCleanup, StackBase);
llvm::Value *F = CGF.CGM.getIntrinsic(llvm::Intrinsic::stackrestore);
// We could load StackBase from StackBaseMem, but in the non-exceptional
// case we can skip it.
CGF.Builder.CreateCall(F, StackBase);
}
}
static void emitNonNullArgCheck(CodeGenFunction &CGF, RValue RV,
QualType ArgType, SourceLocation ArgLoc,
const FunctionDecl *FD, unsigned ParmNum) {
if (!CGF.SanOpts.has(SanitizerKind::NonnullAttribute) || !FD)
return;
auto PVD = ParmNum < FD->getNumParams() ? FD->getParamDecl(ParmNum) : nullptr;
unsigned ArgNo = PVD ? PVD->getFunctionScopeIndex() : ParmNum;
auto NNAttr = getNonNullAttr(FD, PVD, ArgType, ArgNo);
if (!NNAttr)
return;
CodeGenFunction::SanitizerScope SanScope(&CGF);
assert(RV.isScalar());
llvm::Value *V = RV.getScalarVal();
llvm::Value *Cond =
CGF.Builder.CreateICmpNE(V, llvm::Constant::getNullValue(V->getType()));
llvm::Constant *StaticData[] = {
CGF.EmitCheckSourceLocation(ArgLoc),
CGF.EmitCheckSourceLocation(NNAttr->getLocation()),
llvm::ConstantInt::get(CGF.Int32Ty, ArgNo + 1),
};
CGF.EmitCheck(std::make_pair(Cond, SanitizerKind::NonnullAttribute),
"nonnull_arg", StaticData, None);
}
void CodeGenFunction::EmitCallArgs(CallArgList &Args,
ArrayRef<QualType> ArgTypes,
CallExpr::const_arg_iterator ArgBeg,
CallExpr::const_arg_iterator ArgEnd,
const FunctionDecl *CalleeDecl,
unsigned ParamsToSkip,
bool ForceColumnInfo) {
CGDebugInfo *DI = getDebugInfo();
SourceLocation CallLoc;
if (DI) CallLoc = DI->getLocation();
// We *have* to evaluate arguments from right to left in the MS C++ ABI,
// because arguments are destroyed left to right in the callee.
if (CGM.getTarget().getCXXABI().areArgsDestroyedLeftToRightInCallee()) {
// Insert a stack save if we're going to need any inalloca args.
bool HasInAllocaArgs = false;
for (ArrayRef<QualType>::iterator I = ArgTypes.begin(), E = ArgTypes.end();
I != E && !HasInAllocaArgs; ++I)
HasInAllocaArgs = isInAllocaArgument(CGM.getCXXABI(), *I);
if (HasInAllocaArgs) {
assert(getTarget().getTriple().getArch() == llvm::Triple::x86);
Args.allocateArgumentMemory(*this);
}
// Evaluate each argument.
size_t CallArgsStart = Args.size();
for (int I = ArgTypes.size() - 1; I >= 0; --I) {
CallExpr::const_arg_iterator Arg = ArgBeg + I;
EmitCallArg(Args, *Arg, ArgTypes[I]);
emitNonNullArgCheck(*this, Args.back().RV, ArgTypes[I], Arg->getExprLoc(),
CalleeDecl, ParamsToSkip + I);
// Restore the debug location.
if (DI) DI->EmitLocation(Builder, CallLoc, ForceColumnInfo);
}
// Un-reverse the arguments we just evaluated so they match up with the LLVM
// IR function.
std::reverse(Args.begin() + CallArgsStart, Args.end());
return;
}
for (unsigned I = 0, E = ArgTypes.size(); I != E; ++I) {
CallExpr::const_arg_iterator Arg = ArgBeg + I;
assert(Arg != ArgEnd);
EmitCallArg(Args, *Arg, ArgTypes[I]);
emitNonNullArgCheck(*this, Args.back().RV, ArgTypes[I], Arg->getExprLoc(),
CalleeDecl, ParamsToSkip + I);
// Restore the debug location.
if (DI) DI->EmitLocation(Builder, CallLoc, ForceColumnInfo);
}
}
namespace {
struct DestroyUnpassedArg : EHScopeStack::Cleanup {
DestroyUnpassedArg(llvm::Value *Addr, QualType Ty)
: Addr(Addr), Ty(Ty) {}
llvm::Value *Addr;
QualType Ty;
void Emit(CodeGenFunction &CGF, Flags flags) override {
const CXXDestructorDecl *Dtor = Ty->getAsCXXRecordDecl()->getDestructor();
assert(!Dtor->isTrivial());
CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete, /*for vbase*/ false,
/*Delegating=*/false, Addr);
}
};
}
void CodeGenFunction::EmitCallArg(CallArgList &args, const Expr *E,
QualType type) {
if (const ObjCIndirectCopyRestoreExpr *CRE
= dyn_cast<ObjCIndirectCopyRestoreExpr>(E)) {
assert(getLangOpts().ObjCAutoRefCount);
assert(getContext().hasSameType(E->getType(), type));
return emitWritebackArg(*this, args, CRE);
}
assert(type->isReferenceType() == E->isGLValue() &&
"reference binding to unmaterialized r-value!");
if (E->isGLValue()) {
assert(E->getObjectKind() == OK_Ordinary);
return args.add(EmitReferenceBindingToExpr(E), type);
}
bool HasAggregateEvalKind = hasAggregateEvaluationKind(type);
// In the Microsoft C++ ABI, aggregate arguments are destructed by the callee.
// However, we still have to push an EH-only cleanup in case we unwind before
// we make it to the call.
if (HasAggregateEvalKind &&
CGM.getTarget().getCXXABI().areArgsDestroyedLeftToRightInCallee()) {
// If we're using inalloca, use the argument memory. Otherwise, use a
// temporary.
AggValueSlot Slot;
if (args.isUsingInAlloca())
Slot = createPlaceholderSlot(*this, type);
else
Slot = CreateAggTemp(type, "agg.tmp");
const CXXRecordDecl *RD = type->getAsCXXRecordDecl();
bool DestroyedInCallee =
RD && RD->hasNonTrivialDestructor() &&
CGM.getCXXABI().getRecordArgABI(RD) != CGCXXABI::RAA_Default;
if (DestroyedInCallee)
Slot.setExternallyDestructed();
EmitAggExpr(E, Slot);
RValue RV = Slot.asRValue();
args.add(RV, type);
if (DestroyedInCallee) {
// Create a no-op GEP between the placeholder and the cleanup so we can
// RAUW it successfully. It also serves as a marker of the first
// instruction where the cleanup is active.
pushFullExprCleanup<DestroyUnpassedArg>(EHCleanup, Slot.getAddr(), type);
// This unreachable is a temporary marker which will be removed later.
llvm::Instruction *IsActive = Builder.CreateUnreachable();
args.addArgCleanupDeactivation(EHStack.getInnermostEHScope(), IsActive);
}
return;
}
if (HasAggregateEvalKind && isa<ImplicitCastExpr>(E) &&
cast<CastExpr>(E)->getCastKind() == CK_LValueToRValue) {
LValue L = EmitLValue(cast<CastExpr>(E)->getSubExpr());
assert(L.isSimple());
if (L.getAlignment() >= getContext().getTypeAlignInChars(type)) {
args.add(L.asAggregateRValue(), type, /*NeedsCopy*/true);
} else {
// We can't represent a misaligned lvalue in the CallArgList, so copy
// to an aligned temporary now.
llvm::Value *tmp = CreateMemTemp(type);
EmitAggregateCopy(tmp, L.getAddress(), type, L.isVolatile(),
L.getAlignment());
args.add(RValue::getAggregate(tmp), type);
}
return;
}
args.add(EmitAnyExprToTemp(E), type);
}
QualType CodeGenFunction::getVarArgType(const Expr *Arg) {
// System headers on Windows define NULL to 0 instead of 0LL on Win64. MSVC
// implicitly widens null pointer constants that are arguments to varargs
// functions to pointer-sized ints.
if (!getTarget().getTriple().isOSWindows())
return Arg->getType();
if (Arg->getType()->isIntegerType() &&
getContext().getTypeSize(Arg->getType()) <
getContext().getTargetInfo().getPointerWidth(0) &&
Arg->isNullPointerConstant(getContext(),
Expr::NPC_ValueDependentIsNotNull)) {
return getContext().getIntPtrType();
}
return Arg->getType();
}
// In ObjC ARC mode with no ObjC ARC exception safety, tell the ARC
// optimizer it can aggressively ignore unwind edges.
void
CodeGenFunction::AddObjCARCExceptionMetadata(llvm::Instruction *Inst) {
if (CGM.getCodeGenOpts().OptimizationLevel != 0 &&
!CGM.getCodeGenOpts().ObjCAutoRefCountExceptions)
Inst->setMetadata("clang.arc.no_objc_arc_exceptions",
CGM.getNoObjCARCExceptionsMetadata());
}
/// Emits a call to the given no-arguments nounwind runtime function.
llvm::CallInst *
CodeGenFunction::EmitNounwindRuntimeCall(llvm::Value *callee,
const llvm::Twine &name) {
return EmitNounwindRuntimeCall(callee, None, name);
}
/// Emits a call to the given nounwind runtime function.
llvm::CallInst *
CodeGenFunction::EmitNounwindRuntimeCall(llvm::Value *callee,
ArrayRef<llvm::Value*> args,
const llvm::Twine &name) {
llvm::CallInst *call = EmitRuntimeCall(callee, args, name);
call->setDoesNotThrow();
return call;
}
/// Emits a simple call (never an invoke) to the given no-arguments
/// runtime function.
llvm::CallInst *
CodeGenFunction::EmitRuntimeCall(llvm::Value *callee,
const llvm::Twine &name) {
return EmitRuntimeCall(callee, None, name);
}
/// Emits a simple call (never an invoke) to the given runtime
/// function.
llvm::CallInst *
CodeGenFunction::EmitRuntimeCall(llvm::Value *callee,
ArrayRef<llvm::Value*> args,
const llvm::Twine &name) {
llvm::CallInst *call = Builder.CreateCall(callee, args, name);
call->setCallingConv(getRuntimeCC());
return call;
}
/// Emits a call or invoke to the given noreturn runtime function.
void CodeGenFunction::EmitNoreturnRuntimeCallOrInvoke(llvm::Value *callee,
ArrayRef<llvm::Value*> args) {
if (getInvokeDest()) {
llvm::InvokeInst *invoke =
Builder.CreateInvoke(callee,
getUnreachableBlock(),
getInvokeDest(),
args);
invoke->setDoesNotReturn();
invoke->setCallingConv(getRuntimeCC());
} else {
llvm::CallInst *call = Builder.CreateCall(callee, args);
call->setDoesNotReturn();
call->setCallingConv(getRuntimeCC());
Builder.CreateUnreachable();
}
PGO.setCurrentRegionUnreachable();
}
/// Emits a call or invoke instruction to the given nullary runtime
/// function.
llvm::CallSite
CodeGenFunction::EmitRuntimeCallOrInvoke(llvm::Value *callee,
const Twine &name) {
return EmitRuntimeCallOrInvoke(callee, None, name);
}
/// Emits a call or invoke instruction to the given runtime function.
llvm::CallSite
CodeGenFunction::EmitRuntimeCallOrInvoke(llvm::Value *callee,
ArrayRef<llvm::Value*> args,
const Twine &name) {
llvm::CallSite callSite = EmitCallOrInvoke(callee, args, name);
callSite.setCallingConv(getRuntimeCC());
return callSite;
}
llvm::CallSite
CodeGenFunction::EmitCallOrInvoke(llvm::Value *Callee,
const Twine &Name) {
return EmitCallOrInvoke(Callee, None, Name);
}
/// Emits a call or invoke instruction to the given function, depending
/// on the current state of the EH stack.
llvm::CallSite
CodeGenFunction::EmitCallOrInvoke(llvm::Value *Callee,
ArrayRef<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;
}
/// \brief Store a non-aggregate value to an address to initialize it. For
/// initialization, a non-atomic store will be used.
static void EmitInitStoreOfNonAggregate(CodeGenFunction &CGF, RValue Src,
LValue Dst) {
if (Src.isScalar())
CGF.EmitStoreOfScalar(Src.getScalarVal(), Dst, /*init=*/true);
else
CGF.EmitStoreOfComplex(Src.getComplexVal(), Dst, /*init=*/true);
}
void CodeGenFunction::deferPlaceholderReplacement(llvm::Instruction *Old,
llvm::Value *New) {
DeferredReplacements.push_back(std::make_pair(Old, New));
}
RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
llvm::Value *Callee,
ReturnValueSlot ReturnValue,
const CallArgList &CallArgs,
const Decl *TargetDecl,
llvm::Instruction **callOrInvoke) {
// FIXME: We no longer need the types from CallArgs; lift up and simplify.
// Handle struct-return functions by passing a pointer to the
// location that we would like to return into.
QualType RetTy = CallInfo.getReturnType();
const ABIArgInfo &RetAI = CallInfo.getReturnInfo();
llvm::FunctionType *IRFuncTy =
cast<llvm::FunctionType>(
cast<llvm::PointerType>(Callee->getType())->getElementType());
// If we're using inalloca, insert the allocation after the stack save.
// FIXME: Do this earlier rather than hacking it in here!
llvm::Value *ArgMemory = nullptr;
if (llvm::StructType *ArgStruct = CallInfo.getArgStruct()) {
llvm::Instruction *IP = CallArgs.getStackBase();
llvm::AllocaInst *AI;
if (IP) {
IP = IP->getNextNode();
AI = new llvm::AllocaInst(ArgStruct, "argmem", IP);
} else {
AI = CreateTempAlloca(ArgStruct, "argmem");
}
AI->setUsedWithInAlloca(true);
assert(AI->isUsedWithInAlloca() && !AI->isStaticAlloca());
ArgMemory = AI;
}
ClangToLLVMArgMapping IRFunctionArgs(CGM.getContext(), CallInfo);
SmallVector<llvm::Value *, 16> IRCallArgs(IRFunctionArgs.totalIRArgs());
// If the call returns a temporary with struct return, create a temporary
// alloca to hold the result, unless one is given to us.
llvm::Value *SRetPtr = nullptr;
if (RetAI.isIndirect() || RetAI.isInAlloca()) {
SRetPtr = ReturnValue.getValue();
if (!SRetPtr)
SRetPtr = CreateMemTemp(RetTy);
if (IRFunctionArgs.hasSRetArg()) {
IRCallArgs[IRFunctionArgs.getSRetArgNo()] = SRetPtr;
} else {
llvm::Value *Addr =
Builder.CreateStructGEP(ArgMemory, RetAI.getInAllocaFieldIndex());
Builder.CreateStore(SRetPtr, Addr);
}
}
assert(CallInfo.arg_size() == CallArgs.size() &&
"Mismatch between function signature & arguments.");
unsigned ArgNo = 0;
CGFunctionInfo::const_arg_iterator info_it = CallInfo.arg_begin();
for (CallArgList::const_iterator I = CallArgs.begin(), E = CallArgs.end();
I != E; ++I, ++info_it, ++ArgNo) {
const ABIArgInfo &ArgInfo = info_it->info;
RValue RV = I->RV;
CharUnits TypeAlign = getContext().getTypeAlignInChars(I->Ty);
// Insert a padding argument to ensure proper alignment.
if (IRFunctionArgs.hasPaddingArg(ArgNo))
IRCallArgs[IRFunctionArgs.getPaddingArgNo(ArgNo)] =
llvm::UndefValue::get(ArgInfo.getPaddingType());
unsigned FirstIRArg, NumIRArgs;
std::tie(FirstIRArg, NumIRArgs) = IRFunctionArgs.getIRArgs(ArgNo);
switch (ArgInfo.getKind()) {
case ABIArgInfo::InAlloca: {
assert(NumIRArgs == 0);
assert(getTarget().getTriple().getArch() == llvm::Triple::x86);
if (RV.isAggregate()) {
// Replace the placeholder with the appropriate argument slot GEP.
llvm::Instruction *Placeholder =
cast<llvm::Instruction>(RV.getAggregateAddr());
CGBuilderTy::InsertPoint IP = Builder.saveIP();
Builder.SetInsertPoint(Placeholder);
llvm::Value *Addr = Builder.CreateStructGEP(
ArgMemory, ArgInfo.getInAllocaFieldIndex());
Builder.restoreIP(IP);
deferPlaceholderReplacement(Placeholder, Addr);
} else {
// Store the RValue into the argument struct.
llvm::Value *Addr =
Builder.CreateStructGEP(ArgMemory, ArgInfo.getInAllocaFieldIndex());
unsigned AS = Addr->getType()->getPointerAddressSpace();
llvm::Type *MemType = ConvertTypeForMem(I->Ty)->getPointerTo(AS);
// There are some cases where a trivial bitcast is not avoidable. The
// definition of a type later in a translation unit may change it's type
// from {}* to (%struct.foo*)*.
if (Addr->getType() != MemType)
Addr = Builder.CreateBitCast(Addr, MemType);
LValue argLV = MakeAddrLValue(Addr, I->Ty, TypeAlign);
EmitInitStoreOfNonAggregate(*this, RV, argLV);
}
break;
}
case ABIArgInfo::Indirect: {
assert(NumIRArgs == 1);
if (RV.isScalar() || RV.isComplex()) {
// Make a temporary alloca to pass the argument.
llvm::AllocaInst *AI = CreateMemTemp(I->Ty);
if (ArgInfo.getIndirectAlign() > AI->getAlignment())
AI->setAlignment(ArgInfo.getIndirectAlign());
IRCallArgs[FirstIRArg] = AI;
LValue argLV = MakeAddrLValue(AI, I->Ty, TypeAlign);
EmitInitStoreOfNonAggregate(*this, RV, argLV);
} else {
// We want to avoid creating an unnecessary temporary+copy here;
// however, we need one in three cases:
// 1. If the argument is not byval, and we are required to copy the
// source. (This case doesn't occur on any common architecture.)
// 2. If the argument is byval, RV is not sufficiently aligned, and
// we cannot force it to be sufficiently aligned.
// 3. If the argument is byval, but RV is located in an address space
// different than that of the argument (0).
llvm::Value *Addr = RV.getAggregateAddr();
unsigned Align = ArgInfo.getIndirectAlign();
const llvm::DataLayout *TD = &CGM.getDataLayout();
const unsigned RVAddrSpace = Addr->getType()->getPointerAddressSpace();
const unsigned ArgAddrSpace =
(FirstIRArg < IRFuncTy->getNumParams()
? IRFuncTy->getParamType(FirstIRArg)->getPointerAddressSpace()
: 0);
if ((!ArgInfo.getIndirectByVal() && I->NeedsCopy) ||
(ArgInfo.getIndirectByVal() && TypeAlign.getQuantity() < Align &&
llvm::getOrEnforceKnownAlignment(Addr, Align, TD) < Align) ||
(ArgInfo.getIndirectByVal() && (RVAddrSpace != ArgAddrSpace))) {
// Create an aligned temporary, and copy to it.
llvm::AllocaInst *AI = CreateMemTemp(I->Ty);
if (Align > AI->getAlignment())
AI->setAlignment(Align);
IRCallArgs[FirstIRArg] = AI;
EmitAggregateCopy(AI, Addr, I->Ty, RV.isVolatileQualified());
} else {
// Skip the extra memcpy call.
IRCallArgs[FirstIRArg] = Addr;
}
}
break;
}
case ABIArgInfo::Ignore:
assert(NumIRArgs == 0);
break;
case ABIArgInfo::Extend:
case ABIArgInfo::Direct: {
if (!isa<llvm::StructType>(ArgInfo.getCoerceToType()) &&
ArgInfo.getCoerceToType() == ConvertType(info_it->type) &&
ArgInfo.getDirectOffset() == 0) {
assert(NumIRArgs == 1);
llvm::Value *V;
if (RV.isScalar())
V = RV.getScalarVal();
else
V = Builder.CreateLoad(RV.getAggregateAddr());
// We might have to widen integers, but we should never truncate.
if (ArgInfo.getCoerceToType() != V->getType() &&
V->getType()->isIntegerTy())
V = Builder.CreateZExt(V, ArgInfo.getCoerceToType());
// If the argument doesn't match, perform a bitcast to coerce it. This
// can happen due to trivial type mismatches.
if (FirstIRArg < IRFuncTy->getNumParams() &&
V->getType() != IRFuncTy->getParamType(FirstIRArg))
V = Builder.CreateBitCast(V, IRFuncTy->getParamType(FirstIRArg));
IRCallArgs[FirstIRArg] = V;
break;
}
// FIXME: Avoid the conversion through memory if possible.
llvm::Value *SrcPtr;
if (RV.isScalar() || RV.isComplex()) {
SrcPtr = CreateMemTemp(I->Ty, "coerce");
LValue SrcLV = MakeAddrLValue(SrcPtr, I->Ty, TypeAlign);
EmitInitStoreOfNonAggregate(*this, RV, SrcLV);
} 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()));
}
// Fast-isel and the optimizer generally like scalar values better than
// FCAs, so we flatten them if this is safe to do for this argument.
llvm::StructType *STy =
dyn_cast<llvm::StructType>(ArgInfo.getCoerceToType());
if (STy && ArgInfo.isDirect() && ArgInfo.getCanBeFlattened()) {
llvm::Type *SrcTy =
cast<llvm::PointerType>(SrcPtr->getType())->getElementType();
uint64_t SrcSize = CGM.getDataLayout().getTypeAllocSize(SrcTy);
uint64_t DstSize = CGM.getDataLayout().getTypeAllocSize(STy);
// If the source type is smaller than the destination type of the
// coerce-to logic, copy the source value into a temp alloca the size
// of the destination type to allow loading all of it. The bits past
// the source value are left undef.
if (SrcSize < DstSize) {
llvm::AllocaInst *TempAlloca
= CreateTempAlloca(STy, SrcPtr->getName() + ".coerce");
Builder.CreateMemCpy(TempAlloca, SrcPtr, SrcSize, 0);
SrcPtr = TempAlloca;
} else {
SrcPtr = Builder.CreateBitCast(SrcPtr,
llvm::PointerType::getUnqual(STy));
}
assert(NumIRArgs == STy->getNumElements());
for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
llvm::Value *EltPtr = Builder.CreateConstGEP2_32(SrcPtr, 0, i);
llvm::LoadInst *LI = Builder.CreateLoad(EltPtr);
// We don't know what we're loading from.
LI->setAlignment(1);
IRCallArgs[FirstIRArg + i] = LI;
}
} else {
// In the simple case, just pass the coerced loaded value.
assert(NumIRArgs == 1);
IRCallArgs[FirstIRArg] =
CreateCoercedLoad(SrcPtr, ArgInfo.getCoerceToType(), *this);
}
break;
}
case ABIArgInfo::Expand:
unsigned IRArgPos = FirstIRArg;
ExpandTypeToArgs(I->Ty, RV, IRFuncTy, IRCallArgs, IRArgPos);
assert(IRArgPos == FirstIRArg + NumIRArgs);
break;
}
}
if (ArgMemory) {
llvm::Value *Arg = ArgMemory;
if (CallInfo.isVariadic()) {
// When passing non-POD arguments by value to variadic functions, we will
// end up with a variadic prototype and an inalloca call site. In such
// cases, we can't do any parameter mismatch checks. Give up and bitcast
// the callee.
unsigned CalleeAS =
cast<llvm::PointerType>(Callee->getType())->getAddressSpace();
Callee = Builder.CreateBitCast(
Callee, getTypes().GetFunctionType(CallInfo)->getPointerTo(CalleeAS));
} else {
llvm::Type *LastParamTy =
IRFuncTy->getParamType(IRFuncTy->getNumParams() - 1);
if (Arg->getType() != LastParamTy) {
#ifndef NDEBUG
// Assert that these structs have equivalent element types.
llvm::StructType *FullTy = CallInfo.getArgStruct();
llvm::StructType *DeclaredTy = cast<llvm::StructType>(
cast<llvm::PointerType>(LastParamTy)->getElementType());
assert(DeclaredTy->getNumElements() == FullTy->getNumElements());
for (llvm::StructType::element_iterator DI = DeclaredTy->element_begin(),
DE = DeclaredTy->element_end(),
FI = FullTy->element_begin();
DI != DE; ++DI, ++FI)
assert(*DI == *FI);
#endif
Arg = Builder.CreateBitCast(Arg, LastParamTy);
}
}
assert(IRFunctionArgs.hasInallocaArg());
IRCallArgs[IRFunctionArgs.getInallocaArgNo()] = Arg;
}
if (!CallArgs.getCleanupsToDeactivate().empty())
deactivateArgCleanupsBeforeCall(*this, CallArgs);
// If the callee is a bitcast of a function to a varargs pointer to function
// type, check to see if we can remove the bitcast. This handles some cases
// with unprototyped functions.
if (llvm::ConstantExpr *CE = dyn_cast<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() == IRCallArgs.size() &&
(CurFT->isVarArg() || !ActualFT->isVarArg())) {
bool ArgsMatch = true;
for (unsigned i = 0, e = ActualFT->getNumParams(); i != e; ++i)
if (ActualFT->getParamType(i) != CurFT->getParamType(i)) {
ArgsMatch = false;
break;
}
// Strip the cast if we can get away with it. This is a nice cleanup,
// but also allows us to inline the function at -O0 if it is marked
// always_inline.
if (ArgsMatch)
Callee = CalleeF;
}
}
assert(IRCallArgs.size() == IRFuncTy->getNumParams() || IRFuncTy->isVarArg());
for (unsigned i = 0; i < IRCallArgs.size(); ++i) {
// Inalloca argument can have different type.
if (IRFunctionArgs.hasInallocaArg() &&
i == IRFunctionArgs.getInallocaArgNo())
continue;
if (i < IRFuncTy->getNumParams())
assert(IRCallArgs[i]->getType() == IRFuncTy->getParamType(i));
}
unsigned CallingConv;
CodeGen::AttributeListType AttributeList;
CGM.ConstructAttributeList(CallInfo, TargetDecl, AttributeList,
CallingConv, true);
llvm::AttributeSet Attrs = llvm::AttributeSet::get(getLLVMContext(),
AttributeList);
llvm::BasicBlock *InvokeDest = nullptr;
if (!Attrs.hasAttribute(llvm::AttributeSet::FunctionIndex,
llvm::Attribute::NoUnwind))
InvokeDest = getInvokeDest();
llvm::CallSite CS;
if (!InvokeDest) {
CS = Builder.CreateCall(Callee, IRCallArgs);
} else {
llvm::BasicBlock *Cont = createBasicBlock("invoke.cont");
CS = Builder.CreateInvoke(Callee, Cont, InvokeDest, IRCallArgs);
EmitBlock(Cont);
}
if (callOrInvoke)
*callOrInvoke = CS.getInstruction();
if (CurCodeDecl && CurCodeDecl->hasAttr<FlattenAttr>() &&
!CS.hasFnAttr(llvm::Attribute::NoInline))
Attrs =
Attrs.addAttribute(getLLVMContext(), llvm::AttributeSet::FunctionIndex,
llvm::Attribute::AlwaysInline);
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);
// The stack cleanup for inalloca arguments has to run out of the normal
// lexical order, so deactivate it and run it manually here.
CallArgs.freeArgumentMemory(*this);
RValue Ret = [&] {
switch (RetAI.getKind()) {
case ABIArgInfo::InAlloca:
case ABIArgInfo::Indirect:
return convertTempToRValue(SRetPtr, RetTy, SourceLocation());
case ABIArgInfo::Ignore:
// If we are ignoring an argument that had a result, make sure to
// construct the appropriate return value for our caller.
return GetUndefRValue(RetTy);
case ABIArgInfo::Extend:
case ABIArgInfo::Direct: {
llvm::Type *RetIRTy = ConvertType(RetTy);
if (RetAI.getCoerceToType() == RetIRTy && RetAI.getDirectOffset() == 0) {
switch (getEvaluationKind(RetTy)) {
case TEK_Complex: {
llvm::Value *Real = Builder.CreateExtractValue(CI, 0);
llvm::Value *Imag = Builder.CreateExtractValue(CI, 1);
return RValue::getComplex(std::make_pair(Real, Imag));
}
case TEK_Aggregate: {
llvm::Value *DestPtr = ReturnValue.getValue();
bool DestIsVolatile = ReturnValue.isVolatile();
if (!DestPtr) {
DestPtr = CreateMemTemp(RetTy, "agg.tmp");
DestIsVolatile = false;
}
BuildAggStore(*this, CI, DestPtr, DestIsVolatile, false);
return RValue::getAggregate(DestPtr);
}
case TEK_Scalar: {
// If the argument doesn't match, perform a bitcast to coerce it. This
// can happen due to trivial type mismatches.
llvm::Value *V = CI;
if (V->getType() != RetIRTy)
V = Builder.CreateBitCast(V, RetIRTy);
return RValue::get(V);
}
}
llvm_unreachable("bad evaluation kind");
}
llvm::Value *DestPtr = ReturnValue.getValue();
bool DestIsVolatile = ReturnValue.isVolatile();
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);
return convertTempToRValue(DestPtr, RetTy, SourceLocation());
}
case ABIArgInfo::Expand:
llvm_unreachable("Invalid ABI kind for return argument");
}
llvm_unreachable("Unhandled ABIArgInfo::Kind");
} ();
if (Ret.isScalar() && TargetDecl) {
if (const auto *AA = TargetDecl->getAttr<AssumeAlignedAttr>()) {
llvm::Value *OffsetValue = nullptr;
if (const auto *Offset = AA->getOffset())
OffsetValue = EmitScalarExpr(Offset);
llvm::Value *Alignment = EmitScalarExpr(AA->getAlignment());
llvm::ConstantInt *AlignmentCI = cast<llvm::ConstantInt>(Alignment);
EmitAlignmentAssumption(Ret.getScalarVal(), AlignmentCI->getZExtValue(),
OffsetValue);
}
}
return Ret;
}
/* VarArg handling */
llvm::Value *CodeGenFunction::EmitVAArg(llvm::Value *VAListAddr, QualType Ty) {
return CGM.getTypes().getABIInfo().EmitVAArg(VAListAddr, Ty, *this);
}
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