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llvm-for-llvmta/tools/clang/lib/CodeGen/CGCall.cpp

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2022-04-25 13:02:35 +02:00
//===--- CGCall.cpp - Encapsulate calling convention details --------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// These classes wrap the information about a call or function
// definition used to handle ABI compliancy.
//
//===----------------------------------------------------------------------===//
#include "CGCall.h"
#include "ABIInfo.h"
#include "CGBlocks.h"
#include "CGCXXABI.h"
#include "CGCleanup.h"
#include "CGRecordLayout.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "TargetInfo.h"
#include "clang/AST/Attr.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/Basic/CodeGenOptions.h"
#include "clang/Basic/TargetBuiltins.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/CodeGen/CGFunctionInfo.h"
#include "clang/CodeGen/SwiftCallingConv.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/Assumptions.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/CallingConv.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/Transforms/Utils/Local.h"
using namespace clang;
using namespace CodeGen;
/***/
unsigned CodeGenTypes::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_X86RegCall: return llvm::CallingConv::X86_RegCall;
case CC_X86ThisCall: return llvm::CallingConv::X86_ThisCall;
case CC_Win64: return llvm::CallingConv::Win64;
case CC_X86_64SysV: return llvm::CallingConv::X86_64_SysV;
case CC_AAPCS: return llvm::CallingConv::ARM_AAPCS;
case CC_AAPCS_VFP: return llvm::CallingConv::ARM_AAPCS_VFP;
case CC_IntelOclBicc: return llvm::CallingConv::Intel_OCL_BI;
// TODO: Add support for __pascal to LLVM.
case CC_X86Pascal: return llvm::CallingConv::C;
// TODO: Add support for __vectorcall to LLVM.
case CC_X86VectorCall: return llvm::CallingConv::X86_VectorCall;
case CC_AArch64VectorCall: return llvm::CallingConv::AArch64_VectorCall;
case CC_SpirFunction: return llvm::CallingConv::SPIR_FUNC;
case CC_OpenCLKernel: return CGM.getTargetCodeGenInfo().getOpenCLKernelCallingConv();
case CC_PreserveMost: return llvm::CallingConv::PreserveMost;
case CC_PreserveAll: return llvm::CallingConv::PreserveAll;
case CC_Swift: return llvm::CallingConv::Swift;
}
}
/// Derives the 'this' type for codegen purposes, i.e. ignoring method CVR
/// qualification. Either or both of RD and MD may be null. A null RD indicates
/// that there is no meaningful 'this' type, and a null MD can occur when
/// calling a method pointer.
CanQualType CodeGenTypes::DeriveThisType(const CXXRecordDecl *RD,
const CXXMethodDecl *MD) {
QualType RecTy;
if (RD)
RecTy = Context.getTagDeclType(RD)->getCanonicalTypeInternal();
else
RecTy = Context.VoidTy;
if (MD)
RecTy = Context.getAddrSpaceQualType(RecTy, MD->getMethodQualifiers().getAddressSpace());
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(),
/*instanceMethod=*/false,
/*chainCall=*/false, None,
FTNP->getExtInfo(), {}, RequiredArgs(0));
}
static void addExtParameterInfosForCall(
llvm::SmallVectorImpl<FunctionProtoType::ExtParameterInfo> &paramInfos,
const FunctionProtoType *proto,
unsigned prefixArgs,
unsigned totalArgs) {
assert(proto->hasExtParameterInfos());
assert(paramInfos.size() <= prefixArgs);
assert(proto->getNumParams() + prefixArgs <= totalArgs);
paramInfos.reserve(totalArgs);
// Add default infos for any prefix args that don't already have infos.
paramInfos.resize(prefixArgs);
// Add infos for the prototype.
for (const auto &ParamInfo : proto->getExtParameterInfos()) {
paramInfos.push_back(ParamInfo);
// pass_object_size params have no parameter info.
if (ParamInfo.hasPassObjectSize())
paramInfos.emplace_back();
}
assert(paramInfos.size() <= totalArgs &&
"Did we forget to insert pass_object_size args?");
// Add default infos for the variadic and/or suffix arguments.
paramInfos.resize(totalArgs);
}
/// Adds the formal parameters in FPT to the given prefix. If any parameter in
/// FPT has pass_object_size attrs, then we'll add parameters for those, too.
static void appendParameterTypes(const CodeGenTypes &CGT,
SmallVectorImpl<CanQualType> &prefix,
SmallVectorImpl<FunctionProtoType::ExtParameterInfo> &paramInfos,
CanQual<FunctionProtoType> FPT) {
// Fast path: don't touch param info if we don't need to.
if (!FPT->hasExtParameterInfos()) {
assert(paramInfos.empty() &&
"We have paramInfos, but the prototype doesn't?");
prefix.append(FPT->param_type_begin(), FPT->param_type_end());
return;
}
unsigned PrefixSize = prefix.size();
// In the vast majority of cases, we'll have precisely FPT->getNumParams()
// parameters; the only thing that can change this is the presence of
// pass_object_size. So, we preallocate for the common case.
prefix.reserve(prefix.size() + FPT->getNumParams());
auto ExtInfos = FPT->getExtParameterInfos();
assert(ExtInfos.size() == FPT->getNumParams());
for (unsigned I = 0, E = FPT->getNumParams(); I != E; ++I) {
prefix.push_back(FPT->getParamType(I));
if (ExtInfos[I].hasPassObjectSize())
prefix.push_back(CGT.getContext().getSizeType());
}
addExtParameterInfosForCall(paramInfos, FPT.getTypePtr(), PrefixSize,
prefix.size());
}
/// Arrange the LLVM function layout for a value of the given function
/// type, on top of any implicit parameters already stored.
static const CGFunctionInfo &
arrangeLLVMFunctionInfo(CodeGenTypes &CGT, bool instanceMethod,
SmallVectorImpl<CanQualType> &prefix,
CanQual<FunctionProtoType> FTP) {
SmallVector<FunctionProtoType::ExtParameterInfo, 16> paramInfos;
RequiredArgs Required = RequiredArgs::forPrototypePlus(FTP, prefix.size());
// FIXME: Kill copy.
appendParameterTypes(CGT, prefix, paramInfos, FTP);
CanQualType resultType = FTP->getReturnType().getUnqualifiedType();
return CGT.arrangeLLVMFunctionInfo(resultType, instanceMethod,
/*chainCall=*/false, prefix,
FTP->getExtInfo(), paramInfos,
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, /*instanceMethod=*/false, argTypes,
FTP);
}
static CallingConv getCallingConventionForDecl(const ObjCMethodDecl *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<RegCallAttr>())
return CC_X86RegCall;
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<AArch64VectorPcsAttr>())
return CC_AArch64VectorCall;
if (D->hasAttr<IntelOclBiccAttr>())
return CC_IntelOclBicc;
if (D->hasAttr<MSABIAttr>())
return IsWindows ? CC_C : CC_Win64;
if (D->hasAttr<SysVABIAttr>())
return IsWindows ? CC_X86_64SysV : CC_C;
if (D->hasAttr<PreserveMostAttr>())
return CC_PreserveMost;
if (D->hasAttr<PreserveAllAttr>())
return CC_PreserveAll;
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.
/// (A null 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,
const CXXMethodDecl *MD) {
SmallVector<CanQualType, 16> argTypes;
// Add the 'this' pointer.
argTypes.push_back(DeriveThisType(RD, MD));
return ::arrangeLLVMFunctionInfo(
*this, true, argTypes,
FTP->getCanonicalTypeUnqualified().getAs<FunctionProtoType>());
}
/// Set calling convention for CUDA/HIP kernel.
static void setCUDAKernelCallingConvention(CanQualType &FTy, CodeGenModule &CGM,
const FunctionDecl *FD) {
if (FD->hasAttr<CUDAGlobalAttr>()) {
const FunctionType *FT = FTy->getAs<FunctionType>();
CGM.getTargetCodeGenInfo().setCUDAKernelCallingConvention(FT);
FTy = FT->getCanonicalTypeUnqualified();
}
}
/// 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!");
CanQualType FT = GetFormalType(MD).getAs<Type>();
setCUDAKernelCallingConvention(FT, CGM, MD);
auto prototype = FT.getAs<FunctionProtoType>();
if (MD->isInstance()) {
// The abstract case is perfectly fine.
const CXXRecordDecl *ThisType = TheCXXABI.getThisArgumentTypeForMethod(MD);
return arrangeCXXMethodType(ThisType, prototype.getTypePtr(), MD);
}
return arrangeFreeFunctionType(prototype);
}
bool CodeGenTypes::inheritingCtorHasParams(
const InheritedConstructor &Inherited, CXXCtorType Type) {
// Parameters are unnecessary if we're constructing a base class subobject
// and the inherited constructor lives in a virtual base.
return Type == Ctor_Complete ||
!Inherited.getShadowDecl()->constructsVirtualBase() ||
!Target.getCXXABI().hasConstructorVariants();
}
const CGFunctionInfo &
CodeGenTypes::arrangeCXXStructorDeclaration(GlobalDecl GD) {
auto *MD = cast<CXXMethodDecl>(GD.getDecl());
SmallVector<CanQualType, 16> argTypes;
SmallVector<FunctionProtoType::ExtParameterInfo, 16> paramInfos;
argTypes.push_back(DeriveThisType(MD->getParent(), MD));
bool PassParams = true;
if (auto *CD = dyn_cast<CXXConstructorDecl>(MD)) {
// A base class inheriting constructor doesn't get forwarded arguments
// needed to construct a virtual base (or base class thereof).
if (auto Inherited = CD->getInheritedConstructor())
PassParams = inheritingCtorHasParams(Inherited, GD.getCtorType());
}
CanQual<FunctionProtoType> FTP = GetFormalType(MD);
// Add the formal parameters.
if (PassParams)
appendParameterTypes(*this, argTypes, paramInfos, FTP);
CGCXXABI::AddedStructorArgCounts AddedArgs =
TheCXXABI.buildStructorSignature(GD, argTypes);
if (!paramInfos.empty()) {
// Note: prefix implies after the first param.
if (AddedArgs.Prefix)
paramInfos.insert(paramInfos.begin() + 1, AddedArgs.Prefix,
FunctionProtoType::ExtParameterInfo{});
if (AddedArgs.Suffix)
paramInfos.append(AddedArgs.Suffix,
FunctionProtoType::ExtParameterInfo{});
}
RequiredArgs required =
(PassParams && MD->isVariadic() ? RequiredArgs(argTypes.size())
: RequiredArgs::All);
FunctionType::ExtInfo extInfo = FTP->getExtInfo();
CanQualType resultType = TheCXXABI.HasThisReturn(GD)
? argTypes.front()
: TheCXXABI.hasMostDerivedReturn(GD)
? CGM.getContext().VoidPtrTy
: Context.VoidTy;
return arrangeLLVMFunctionInfo(resultType, /*instanceMethod=*/true,
/*chainCall=*/false, argTypes, extInfo,
paramInfos, required);
}
static SmallVector<CanQualType, 16>
getArgTypesForCall(ASTContext &ctx, const CallArgList &args) {
SmallVector<CanQualType, 16> argTypes;
for (auto &arg : args)
argTypes.push_back(ctx.getCanonicalParamType(arg.Ty));
return argTypes;
}
static SmallVector<CanQualType, 16>
getArgTypesForDeclaration(ASTContext &ctx, const FunctionArgList &args) {
SmallVector<CanQualType, 16> argTypes;
for (auto &arg : args)
argTypes.push_back(ctx.getCanonicalParamType(arg->getType()));
return argTypes;
}
static llvm::SmallVector<FunctionProtoType::ExtParameterInfo, 16>
getExtParameterInfosForCall(const FunctionProtoType *proto,
unsigned prefixArgs, unsigned totalArgs) {
llvm::SmallVector<FunctionProtoType::ExtParameterInfo, 16> result;
if (proto->hasExtParameterInfos()) {
addExtParameterInfosForCall(result, proto, prefixArgs, totalArgs);
}
return result;
}
/// Arrange a call to a C++ method, passing the given arguments.
///
/// ExtraPrefixArgs is the number of ABI-specific args passed after the `this`
/// parameter.
/// ExtraSuffixArgs is the number of ABI-specific args passed at the end of
/// args.
/// PassProtoArgs indicates whether `args` has args for the parameters in the
/// given CXXConstructorDecl.
const CGFunctionInfo &
CodeGenTypes::arrangeCXXConstructorCall(const CallArgList &args,
const CXXConstructorDecl *D,
CXXCtorType CtorKind,
unsigned ExtraPrefixArgs,
unsigned ExtraSuffixArgs,
bool PassProtoArgs) {
// FIXME: Kill copy.
SmallVector<CanQualType, 16> ArgTypes;
for (const auto &Arg : args)
ArgTypes.push_back(Context.getCanonicalParamType(Arg.Ty));
// +1 for implicit this, which should always be args[0].
unsigned TotalPrefixArgs = 1 + ExtraPrefixArgs;
CanQual<FunctionProtoType> FPT = GetFormalType(D);
RequiredArgs Required = PassProtoArgs
? RequiredArgs::forPrototypePlus(
FPT, TotalPrefixArgs + ExtraSuffixArgs)
: RequiredArgs::All;
GlobalDecl GD(D, CtorKind);
CanQualType ResultType = TheCXXABI.HasThisReturn(GD)
? ArgTypes.front()
: TheCXXABI.hasMostDerivedReturn(GD)
? CGM.getContext().VoidPtrTy
: Context.VoidTy;
FunctionType::ExtInfo Info = FPT->getExtInfo();
llvm::SmallVector<FunctionProtoType::ExtParameterInfo, 16> ParamInfos;
// If the prototype args are elided, we should only have ABI-specific args,
// which never have param info.
if (PassProtoArgs && FPT->hasExtParameterInfos()) {
// ABI-specific suffix arguments are treated the same as variadic arguments.
addExtParameterInfosForCall(ParamInfos, FPT.getTypePtr(), TotalPrefixArgs,
ArgTypes.size());
}
return arrangeLLVMFunctionInfo(ResultType, /*instanceMethod=*/true,
/*chainCall=*/false, ArgTypes, Info,
ParamInfos, 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));
setCUDAKernelCallingConvention(FTy, CGM, FD);
// When declaring a function without a prototype, always use a
// non-variadic type.
if (CanQual<FunctionNoProtoType> noProto = FTy.getAs<FunctionNoProtoType>()) {
return arrangeLLVMFunctionInfo(
noProto->getReturnType(), /*instanceMethod=*/false,
/*chainCall=*/false, None, noProto->getExtInfo(), {},RequiredArgs::All);
}
return arrangeFreeFunctionType(FTy.castAs<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;
SmallVector<FunctionProtoType::ExtParameterInfo, 4> extParamInfos(2);
argTys.push_back(Context.getCanonicalParamType(receiverType));
argTys.push_back(Context.getCanonicalParamType(Context.getObjCSelType()));
// FIXME: Kill copy?
for (const auto *I : MD->parameters()) {
argTys.push_back(Context.getCanonicalParamType(I->getType()));
auto extParamInfo = FunctionProtoType::ExtParameterInfo().withIsNoEscape(
I->hasAttr<NoEscapeAttr>());
extParamInfos.push_back(extParamInfo);
}
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()), /*instanceMethod=*/false,
/*chainCall=*/false, argTys, einfo, extParamInfos, required);
}
const CGFunctionInfo &
CodeGenTypes::arrangeUnprototypedObjCMessageSend(QualType returnType,
const CallArgList &args) {
auto argTypes = getArgTypesForCall(Context, args);
FunctionType::ExtInfo einfo;
return arrangeLLVMFunctionInfo(
GetReturnType(returnType), /*instanceMethod=*/false,
/*chainCall=*/false, argTypes, einfo, {}, RequiredArgs::All);
}
const CGFunctionInfo &
CodeGenTypes::arrangeGlobalDeclaration(GlobalDecl GD) {
// FIXME: Do we need to handle ObjCMethodDecl?
const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
if (isa<CXXConstructorDecl>(GD.getDecl()) ||
isa<CXXDestructorDecl>(GD.getDecl()))
return arrangeCXXStructorDeclaration(GD);
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::arrangeUnprototypedMustTailThunk(const CXXMethodDecl *MD) {
assert(MD->isVirtual() && "only methods have thunks");
CanQual<FunctionProtoType> FTP = GetFormalType(MD);
CanQualType ArgTys[] = {DeriveThisType(MD->getParent(), MD)};
return arrangeLLVMFunctionInfo(Context.VoidTy, /*instanceMethod=*/false,
/*chainCall=*/false, ArgTys,
FTP->getExtInfo(), {}, RequiredArgs(1));
}
const CGFunctionInfo &
CodeGenTypes::arrangeMSCtorClosure(const CXXConstructorDecl *CD,
CXXCtorType CT) {
assert(CT == Ctor_CopyingClosure || CT == Ctor_DefaultClosure);
CanQual<FunctionProtoType> FTP = GetFormalType(CD);
SmallVector<CanQualType, 2> ArgTys;
const CXXRecordDecl *RD = CD->getParent();
ArgTys.push_back(DeriveThisType(RD, CD));
if (CT == Ctor_CopyingClosure)
ArgTys.push_back(*FTP->param_type_begin());
if (RD->getNumVBases() > 0)
ArgTys.push_back(Context.IntTy);
CallingConv CC = Context.getDefaultCallingConvention(
/*IsVariadic=*/false, /*IsCXXMethod=*/true);
return arrangeLLVMFunctionInfo(Context.VoidTy, /*instanceMethod=*/true,
/*chainCall=*/false, ArgTys,
FunctionType::ExtInfo(CC), {},
RequiredArgs::All);
}
/// Arrange a call as unto a free function, except possibly with an
/// additional number of formal parameters considered required.
static const CGFunctionInfo &
arrangeFreeFunctionLikeCall(CodeGenTypes &CGT,
CodeGenModule &CGM,
const CallArgList &args,
const FunctionType *fnType,
unsigned numExtraRequiredArgs,
bool chainCall) {
assert(args.size() >= numExtraRequiredArgs);
llvm::SmallVector<FunctionProtoType::ExtParameterInfo, 16> paramInfos;
// 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::forPrototypePlus(proto, numExtraRequiredArgs);
if (proto->hasExtParameterInfos())
addExtParameterInfosForCall(paramInfos, proto, numExtraRequiredArgs,
args.size());
// 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());
}
// FIXME: Kill copy.
SmallVector<CanQualType, 16> argTypes;
for (const auto &arg : args)
argTypes.push_back(CGT.getContext().getCanonicalParamType(arg.Ty));
return CGT.arrangeLLVMFunctionInfo(GetReturnType(fnType->getReturnType()),
/*instanceMethod=*/false, chainCall,
argTypes, fnType->getExtInfo(), paramInfos,
required);
}
/// Figure out the rules for calling a function with the given formal
/// type using the given arguments. The arguments are necessary
/// because the function might be unprototyped, in which case it's
/// target-dependent in crazy ways.
const CGFunctionInfo &
CodeGenTypes::arrangeFreeFunctionCall(const CallArgList &args,
const FunctionType *fnType,
bool chainCall) {
return arrangeFreeFunctionLikeCall(*this, CGM, args, fnType,
chainCall ? 1 : 0, chainCall);
}
/// A block function is essentially a free function with an
/// extra implicit argument.
const CGFunctionInfo &
CodeGenTypes::arrangeBlockFunctionCall(const CallArgList &args,
const FunctionType *fnType) {
return arrangeFreeFunctionLikeCall(*this, CGM, args, fnType, 1,
/*chainCall=*/false);
}
const CGFunctionInfo &
CodeGenTypes::arrangeBlockFunctionDeclaration(const FunctionProtoType *proto,
const FunctionArgList &params) {
auto paramInfos = getExtParameterInfosForCall(proto, 1, params.size());
auto argTypes = getArgTypesForDeclaration(Context, params);
return arrangeLLVMFunctionInfo(GetReturnType(proto->getReturnType()),
/*instanceMethod*/ false, /*chainCall*/ false,
argTypes, proto->getExtInfo(), paramInfos,
RequiredArgs::forPrototypePlus(proto, 1));
}
const CGFunctionInfo &
CodeGenTypes::arrangeBuiltinFunctionCall(QualType resultType,
const CallArgList &args) {
// FIXME: Kill copy.
SmallVector<CanQualType, 16> argTypes;
for (const auto &Arg : args)
argTypes.push_back(Context.getCanonicalParamType(Arg.Ty));
return arrangeLLVMFunctionInfo(
GetReturnType(resultType), /*instanceMethod=*/false,
/*chainCall=*/false, argTypes, FunctionType::ExtInfo(),
/*paramInfos=*/ {}, RequiredArgs::All);
}
const CGFunctionInfo &
CodeGenTypes::arrangeBuiltinFunctionDeclaration(QualType resultType,
const FunctionArgList &args) {
auto argTypes = getArgTypesForDeclaration(Context, args);
return arrangeLLVMFunctionInfo(
GetReturnType(resultType), /*instanceMethod=*/false, /*chainCall=*/false,
argTypes, FunctionType::ExtInfo(), {}, RequiredArgs::All);
}
const CGFunctionInfo &
CodeGenTypes::arrangeBuiltinFunctionDeclaration(CanQualType resultType,
ArrayRef<CanQualType> argTypes) {
return arrangeLLVMFunctionInfo(
resultType, /*instanceMethod=*/false, /*chainCall=*/false,
argTypes, FunctionType::ExtInfo(), {}, RequiredArgs::All);
}
/// Arrange a call to a C++ method, passing the given arguments.
///
/// numPrefixArgs is the number of ABI-specific prefix arguments we have. It
/// does not count `this`.
const CGFunctionInfo &
CodeGenTypes::arrangeCXXMethodCall(const CallArgList &args,
const FunctionProtoType *proto,
RequiredArgs required,
unsigned numPrefixArgs) {
assert(numPrefixArgs + 1 <= args.size() &&
"Emitting a call with less args than the required prefix?");
// Add one to account for `this`. It's a bit awkward here, but we don't count
// `this` in similar places elsewhere.
auto paramInfos =
getExtParameterInfosForCall(proto, numPrefixArgs + 1, args.size());
// FIXME: Kill copy.
auto argTypes = getArgTypesForCall(Context, args);
FunctionType::ExtInfo info = proto->getExtInfo();
return arrangeLLVMFunctionInfo(
GetReturnType(proto->getReturnType()), /*instanceMethod=*/true,
/*chainCall=*/false, argTypes, info, paramInfos, required);
}
const CGFunctionInfo &CodeGenTypes::arrangeNullaryFunction() {
return arrangeLLVMFunctionInfo(
getContext().VoidTy, /*instanceMethod=*/false, /*chainCall=*/false,
None, FunctionType::ExtInfo(), {}, RequiredArgs::All);
}
const CGFunctionInfo &
CodeGenTypes::arrangeCall(const CGFunctionInfo &signature,
const CallArgList &args) {
assert(signature.arg_size() <= args.size());
if (signature.arg_size() == args.size())
return signature;
SmallVector<FunctionProtoType::ExtParameterInfo, 16> paramInfos;
auto sigParamInfos = signature.getExtParameterInfos();
if (!sigParamInfos.empty()) {
paramInfos.append(sigParamInfos.begin(), sigParamInfos.end());
paramInfos.resize(args.size());
}
auto argTypes = getArgTypesForCall(Context, args);
assert(signature.getRequiredArgs().allowsOptionalArgs());
return arrangeLLVMFunctionInfo(signature.getReturnType(),
signature.isInstanceMethod(),
signature.isChainCall(),
argTypes,
signature.getExtInfo(),
paramInfos,
signature.getRequiredArgs());
}
namespace clang {
namespace CodeGen {
void computeSPIRKernelABIInfo(CodeGenModule &CGM, CGFunctionInfo &FI);
}
}
/// Arrange the argument and result information for an abstract value
/// of a given function type. This is the method which all of the
/// above functions ultimately defer to.
const CGFunctionInfo &
CodeGenTypes::arrangeLLVMFunctionInfo(CanQualType resultType,
bool instanceMethod,
bool chainCall,
ArrayRef<CanQualType> argTypes,
FunctionType::ExtInfo info,
ArrayRef<FunctionProtoType::ExtParameterInfo> paramInfos,
RequiredArgs required) {
assert(llvm::all_of(argTypes,
[](CanQualType T) { return T.isCanonicalAsParam(); }));
// Lookup or create unique function info.
llvm::FoldingSetNodeID ID;
CGFunctionInfo::Profile(ID, instanceMethod, chainCall, info, paramInfos,
required, resultType, argTypes);
void *insertPos = nullptr;
CGFunctionInfo *FI = FunctionInfos.FindNodeOrInsertPos(ID, insertPos);
if (FI)
return *FI;
unsigned CC = ClangCallConvToLLVMCallConv(info.getCC());
// Construct the function info. We co-allocate the ArgInfos.
FI = CGFunctionInfo::create(CC, instanceMethod, chainCall, info,
paramInfos, resultType, argTypes, required);
FunctionInfos.InsertNode(FI, insertPos);
bool inserted = FunctionsBeingProcessed.insert(FI).second;
(void)inserted;
assert(inserted && "Recursively being processed?");
// Compute ABI information.
if (CC == llvm::CallingConv::SPIR_KERNEL) {
// Force target independent argument handling for the host visible
// kernel functions.
computeSPIRKernelABIInfo(CGM, *FI);
} else if (info.getCC() == CC_Swift) {
swiftcall::computeABIInfo(CGM, *FI);
} else {
getABIInfo().computeInfo(*FI);
}
// Loop over all of the computed argument and return value info. If any of
// them are direct or extend without a specified coerce type, specify the
// default now.
ABIArgInfo &retInfo = FI->getReturnInfo();
if (retInfo.canHaveCoerceToType() && retInfo.getCoerceToType() == nullptr)
retInfo.setCoerceToType(ConvertType(FI->getReturnType()));
for (auto &I : FI->arguments())
if (I.info.canHaveCoerceToType() && I.info.getCoerceToType() == nullptr)
I.info.setCoerceToType(ConvertType(I.type));
bool erased = FunctionsBeingProcessed.erase(FI); (void)erased;
assert(erased && "Not in set?");
return *FI;
}
CGFunctionInfo *CGFunctionInfo::create(unsigned llvmCC,
bool instanceMethod,
bool chainCall,
const FunctionType::ExtInfo &info,
ArrayRef<ExtParameterInfo> paramInfos,
CanQualType resultType,
ArrayRef<CanQualType> argTypes,
RequiredArgs required) {
assert(paramInfos.empty() || paramInfos.size() == argTypes.size());
assert(!required.allowsOptionalArgs() ||
required.getNumRequiredArgs() <= argTypes.size());
void *buffer =
operator new(totalSizeToAlloc<ArgInfo, ExtParameterInfo>(
argTypes.size() + 1, paramInfos.size()));
CGFunctionInfo *FI = new(buffer) CGFunctionInfo();
FI->CallingConvention = llvmCC;
FI->EffectiveCallingConvention = llvmCC;
FI->ASTCallingConvention = info.getCC();
FI->InstanceMethod = instanceMethod;
FI->ChainCall = chainCall;
FI->CmseNSCall = info.getCmseNSCall();
FI->NoReturn = info.getNoReturn();
FI->ReturnsRetained = info.getProducesResult();
FI->NoCallerSavedRegs = info.getNoCallerSavedRegs();
FI->NoCfCheck = info.getNoCfCheck();
FI->Required = required;
FI->HasRegParm = info.getHasRegParm();
FI->RegParm = info.getRegParm();
FI->ArgStruct = nullptr;
FI->ArgStructAlign = 0;
FI->NumArgs = argTypes.size();
FI->HasExtParameterInfos = !paramInfos.empty();
FI->getArgsBuffer()[0].type = resultType;
for (unsigned i = 0, e = argTypes.size(); i != e; ++i)
FI->getArgsBuffer()[i + 1].type = argTypes[i];
for (unsigned i = 0, e = paramInfos.size(); i != e; ++i)
FI->getExtParameterInfosBuffer()[i] = paramInfos[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(std::move(Bases)),
Fields(std::move(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 std::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()) {
if (FD->isZeroLengthBitField(Context))
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()) {
if (FD->isZeroLengthBitField(Context))
continue;
assert(!FD->isBitField() &&
"Cannot expand structure with bit-field members.");
Fields.push_back(FD);
}
}
return std::make_unique<RecordExpansion>(std::move(Bases),
std::move(Fields));
}
if (const ComplexType *CT = Ty->getAs<ComplexType>()) {
return std::make_unique<ComplexExpansion>(CT->getElementType());
}
return std::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);
}
}
static void forConstantArrayExpansion(CodeGenFunction &CGF,
ConstantArrayExpansion *CAE,
Address BaseAddr,
llvm::function_ref<void(Address)> Fn) {
CharUnits EltSize = CGF.getContext().getTypeSizeInChars(CAE->EltTy);
CharUnits EltAlign =
BaseAddr.getAlignment().alignmentOfArrayElement(EltSize);
for (int i = 0, n = CAE->NumElts; i < n; i++) {
llvm::Value *EltAddr =
CGF.Builder.CreateConstGEP2_32(nullptr, BaseAddr.getPointer(), 0, i);
Fn(Address(EltAddr, EltAlign));
}
}
void CodeGenFunction::ExpandTypeFromArgs(QualType Ty, LValue LV,
llvm::Function::arg_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())) {
forConstantArrayExpansion(
*this, CAExp, LV.getAddress(*this), [&](Address EltAddr) {
LValue LV = MakeAddrLValue(EltAddr, CAExp->EltTy);
ExpandTypeFromArgs(CAExp->EltTy, LV, AI);
});
} else if (auto RExp = dyn_cast<RecordExpansion>(Exp.get())) {
Address This = LV.getAddress(*this);
for (const CXXBaseSpecifier *BS : RExp->Bases) {
// Perform a single step derived-to-base conversion.
Address 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 = EmitLValueForFieldInitialization(LV, FD);
ExpandTypeFromArgs(FD->getType(), SubLV, AI);
}
} else if (isa<ComplexExpansion>(Exp.get())) {
auto realValue = &*AI++;
auto imagValue = &*AI++;
EmitStoreOfComplex(ComplexPairTy(realValue, imagValue), LV, /*init*/ true);
} else {
// Call EmitStoreOfScalar except when the lvalue is a bitfield to emit a
// primitive store.
assert(isa<NoExpansion>(Exp.get()));
if (LV.isBitField())
EmitStoreThroughLValue(RValue::get(&*AI++), LV);
else
EmitStoreOfScalar(&*AI++, LV);
}
}
void CodeGenFunction::ExpandTypeToArgs(
QualType Ty, CallArg Arg, llvm::FunctionType *IRFuncTy,
SmallVectorImpl<llvm::Value *> &IRCallArgs, unsigned &IRCallArgPos) {
auto Exp = getTypeExpansion(Ty, getContext());
if (auto CAExp = dyn_cast<ConstantArrayExpansion>(Exp.get())) {
Address Addr = Arg.hasLValue() ? Arg.getKnownLValue().getAddress(*this)
: Arg.getKnownRValue().getAggregateAddress();
forConstantArrayExpansion(
*this, CAExp, Addr, [&](Address EltAddr) {
CallArg EltArg = CallArg(
convertTempToRValue(EltAddr, CAExp->EltTy, SourceLocation()),
CAExp->EltTy);
ExpandTypeToArgs(CAExp->EltTy, EltArg, IRFuncTy, IRCallArgs,
IRCallArgPos);
});
} else if (auto RExp = dyn_cast<RecordExpansion>(Exp.get())) {
Address This = Arg.hasLValue() ? Arg.getKnownLValue().getAddress(*this)
: Arg.getKnownRValue().getAggregateAddress();
for (const CXXBaseSpecifier *BS : RExp->Bases) {
// Perform a single step derived-to-base conversion.
Address Base =
GetAddressOfBaseClass(This, Ty->getAsCXXRecordDecl(), &BS, &BS + 1,
/*NullCheckValue=*/false, SourceLocation());
CallArg BaseArg = CallArg(RValue::getAggregate(Base), BS->getType());
// Recurse onto bases.
ExpandTypeToArgs(BS->getType(), BaseArg, IRFuncTy, IRCallArgs,
IRCallArgPos);
}
LValue LV = MakeAddrLValue(This, Ty);
for (auto FD : RExp->Fields) {
CallArg FldArg =
CallArg(EmitRValueForField(LV, FD, SourceLocation()), FD->getType());
ExpandTypeToArgs(FD->getType(), FldArg, IRFuncTy, IRCallArgs,
IRCallArgPos);
}
} else if (isa<ComplexExpansion>(Exp.get())) {
ComplexPairTy CV = Arg.getKnownRValue().getComplexVal();
IRCallArgs[IRCallArgPos++] = CV.first;
IRCallArgs[IRCallArgPos++] = CV.second;
} else {
assert(isa<NoExpansion>(Exp.get()));
auto RV = Arg.getKnownRValue();
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;
}
}
/// Create a temporary allocation for the purposes of coercion.
static Address CreateTempAllocaForCoercion(CodeGenFunction &CGF, llvm::Type *Ty,
CharUnits MinAlign,
const Twine &Name = "tmp") {
// Don't use an alignment that's worse than what LLVM would prefer.
auto PrefAlign = CGF.CGM.getDataLayout().getPrefTypeAlignment(Ty);
CharUnits Align = std::max(MinAlign, CharUnits::fromQuantity(PrefAlign));
return CGF.CreateTempAlloca(Ty, Align, Name + ".coerce");
}
/// 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 Address
EnterStructPointerForCoercedAccess(Address 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.CreateStructGEP(SrcPtr, 0, "coerce.dive");
// If the first element is a struct, recurse.
llvm::Type *SrcTy = SrcPtr.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, known to be aligned to
/// \arg SrcAlign bytes.
///
/// This safely handles the case when the src type is smaller than the
/// destination type; in this situation the values of bits which not
/// present in the src are undefined.
static llvm::Value *CreateCoercedLoad(Address Src, llvm::Type *Ty,
CodeGenFunction &CGF) {
llvm::Type *SrcTy = Src.getElementType();
// If SrcTy and Ty are the same, just do a load.
if (SrcTy == Ty)
return CGF.Builder.CreateLoad(Src);
llvm::TypeSize DstSize = CGF.CGM.getDataLayout().getTypeAllocSize(Ty);
if (llvm::StructType *SrcSTy = dyn_cast<llvm::StructType>(SrcTy)) {
Src = EnterStructPointerForCoercedAccess(Src, SrcSTy,
DstSize.getFixedSize(), CGF);
SrcTy = Src.getElementType();
}
llvm::TypeSize 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::Value *Load = CGF.Builder.CreateLoad(Src);
return CoerceIntOrPtrToIntOrPtr(Load, Ty, CGF);
}
// If load is legal, just bitcast the src pointer.
if (!SrcSize.isScalable() && !DstSize.isScalable() &&
SrcSize.getFixedSize() >= DstSize.getFixedSize()) {
// 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.
Src = CGF.Builder.CreateBitCast(Src,
Ty->getPointerTo(Src.getAddressSpace()));
return CGF.Builder.CreateLoad(Src);
}
// If coercing a fixed vector to a scalable vector for ABI compatibility, and
// the types match, use the llvm.experimental.vector.insert intrinsic to
// perform the conversion.
if (auto *ScalableDst = dyn_cast<llvm::ScalableVectorType>(Ty)) {
if (auto *FixedSrc = dyn_cast<llvm::FixedVectorType>(SrcTy)) {
if (ScalableDst->getElementType() == FixedSrc->getElementType()) {
auto *Load = CGF.Builder.CreateLoad(Src);
auto *UndefVec = llvm::UndefValue::get(ScalableDst);
auto *Zero = llvm::Constant::getNullValue(CGF.CGM.Int64Ty);
return CGF.Builder.CreateInsertVector(ScalableDst, UndefVec, Load, Zero,
"castScalableSve");
}
}
}
// Otherwise do coercion through memory. This is stupid, but simple.
Address Tmp =
CreateTempAllocaForCoercion(CGF, Ty, Src.getAlignment(), Src.getName());
CGF.Builder.CreateMemCpy(
Tmp.getPointer(), Tmp.getAlignment().getAsAlign(), Src.getPointer(),
Src.getAlignment().getAsAlign(),
llvm::ConstantInt::get(CGF.IntPtrTy, SrcSize.getKnownMinSize()));
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?
void CodeGenFunction::EmitAggregateStore(llvm::Value *Val, Address Dest,
bool DestIsVolatile) {
// 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) {
Address EltPtr = Builder.CreateStructGEP(Dest, i);
llvm::Value *Elt = Builder.CreateExtractValue(Val, i);
Builder.CreateStore(Elt, EltPtr, DestIsVolatile);
}
} else {
Builder.CreateStore(Val, Dest, DestIsVolatile);
}
}
/// CreateCoercedStore - Create a store to \arg DstPtr from \arg Src,
/// where the source and destination may have different types. The
/// destination is known to be aligned to \arg DstAlign bytes.
///
/// This safely handles the case when the src type is larger than the
/// destination type; the upper bits of the src will be lost.
static void CreateCoercedStore(llvm::Value *Src,
Address Dst,
bool DstIsVolatile,
CodeGenFunction &CGF) {
llvm::Type *SrcTy = Src->getType();
llvm::Type *DstTy = Dst.getElementType();
if (SrcTy == DstTy) {
CGF.Builder.CreateStore(Src, Dst, DstIsVolatile);
return;
}
llvm::TypeSize SrcSize = CGF.CGM.getDataLayout().getTypeAllocSize(SrcTy);
if (llvm::StructType *DstSTy = dyn_cast<llvm::StructType>(DstTy)) {
Dst = EnterStructPointerForCoercedAccess(Dst, DstSTy,
SrcSize.getFixedSize(), CGF);
DstTy = Dst.getElementType();
}
llvm::PointerType *SrcPtrTy = llvm::dyn_cast<llvm::PointerType>(SrcTy);
llvm::PointerType *DstPtrTy = llvm::dyn_cast<llvm::PointerType>(DstTy);
if (SrcPtrTy && DstPtrTy &&
SrcPtrTy->getAddressSpace() != DstPtrTy->getAddressSpace()) {
Src = CGF.Builder.CreatePointerBitCastOrAddrSpaceCast(Src, DstTy);
CGF.Builder.CreateStore(Src, Dst, DstIsVolatile);
return;
}
// 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, Dst, DstIsVolatile);
return;
}
llvm::TypeSize DstSize = CGF.CGM.getDataLayout().getTypeAllocSize(DstTy);
// If store is legal, just bitcast the src pointer.
if (isa<llvm::ScalableVectorType>(SrcTy) ||
isa<llvm::ScalableVectorType>(DstTy) ||
SrcSize.getFixedSize() <= DstSize.getFixedSize()) {
Dst = CGF.Builder.CreateElementBitCast(Dst, SrcTy);
CGF.EmitAggregateStore(Src, Dst, DstIsVolatile);
} 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.
Address Tmp = CreateTempAllocaForCoercion(CGF, SrcTy, Dst.getAlignment());
CGF.Builder.CreateStore(Src, Tmp);
CGF.Builder.CreateMemCpy(
Dst.getPointer(), Dst.getAlignment().getAsAlign(), Tmp.getPointer(),
Tmp.getAlignment().getAsAlign(),
llvm::ConstantInt::get(CGF.IntPtrTy, DstSize.getFixedSize()));
}
}
static Address emitAddressAtOffset(CodeGenFunction &CGF, Address addr,
const ABIArgInfo &info) {
if (unsigned offset = info.getDirectOffset()) {
addr = CGF.Builder.CreateElementBitCast(addr, CGF.Int8Ty);
addr = CGF.Builder.CreateConstInBoundsByteGEP(addr,
CharUnits::fromQuantity(offset));
addr = CGF.Builder.CreateElementBitCast(addr, info.getCoerceToType());
}
return addr;
}
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:
case ABIArgInfo::IndirectAliased:
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::CoerceAndExpand:
IRArgs.NumberOfArgs = AI.getCoerceAndExpandTypeSequence().size();
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) {
const auto &RI = FI.getReturnInfo();
return RI.isIndirect() || (RI.isInAlloca() && RI.getInAllocaSRet());
}
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:
case ABIArgInfo::IndirectAliased:
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:
case ABIArgInfo::Ignore:
resultType = llvm::Type::getVoidTy(getLLVMContext());
break;
case ABIArgInfo::CoerceAndExpand:
resultType = retAI.getUnpaddedCoerceAndExpandType();
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 alloca addr space.
llvm::Type *LTy = ConvertTypeForMem(it->type);
ArgTypes[FirstIRArg] = LTy->getPointerTo(
CGM.getDataLayout().getAllocaAddrSpace());
break;
}
case ABIArgInfo::IndirectAliased: {
assert(NumIRArgs == 1);
llvm::Type *LTy = ConvertTypeForMem(it->type);
ArgTypes[FirstIRArg] = LTy->getPointerTo(ArgInfo.getIndirectAddrSpace());
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::CoerceAndExpand: {
auto ArgTypesIter = ArgTypes.begin() + FirstIRArg;
for (auto EltTy : ArgInfo.getCoerceAndExpandTypeSequence()) {
*ArgTypesIter++ = EltTy;
}
assert(ArgTypesIter == ArgTypes.begin() + FirstIRArg + NumIRArgs);
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());
return GetFunctionType(GD);
}
static void AddAttributesFromFunctionProtoType(ASTContext &Ctx,
llvm::AttrBuilder &FuncAttrs,
const FunctionProtoType *FPT) {
if (!FPT)
return;
if (!isUnresolvedExceptionSpec(FPT->getExceptionSpecType()) &&
FPT->isNothrow())
FuncAttrs.addAttribute(llvm::Attribute::NoUnwind);
}
void CodeGenModule::getDefaultFunctionAttributes(StringRef Name,
bool HasOptnone,
bool AttrOnCallSite,
llvm::AttrBuilder &FuncAttrs) {
// OptimizeNoneAttr takes precedence over -Os or -Oz. No warning needed.
if (!HasOptnone) {
if (CodeGenOpts.OptimizeSize)
FuncAttrs.addAttribute(llvm::Attribute::OptimizeForSize);
if (CodeGenOpts.OptimizeSize == 2)
FuncAttrs.addAttribute(llvm::Attribute::MinSize);
}
if (CodeGenOpts.DisableRedZone)
FuncAttrs.addAttribute(llvm::Attribute::NoRedZone);
if (CodeGenOpts.IndirectTlsSegRefs)
FuncAttrs.addAttribute("indirect-tls-seg-refs");
if (CodeGenOpts.NoImplicitFloat)
FuncAttrs.addAttribute(llvm::Attribute::NoImplicitFloat);
if (AttrOnCallSite) {
// Attributes that should go on the call site only.
if (!CodeGenOpts.SimplifyLibCalls ||
CodeGenOpts.isNoBuiltinFunc(Name.data()))
FuncAttrs.addAttribute(llvm::Attribute::NoBuiltin);
if (!CodeGenOpts.TrapFuncName.empty())
FuncAttrs.addAttribute("trap-func-name", CodeGenOpts.TrapFuncName);
} else {
StringRef FpKind;
switch (CodeGenOpts.getFramePointer()) {
case CodeGenOptions::FramePointerKind::None:
FpKind = "none";
break;
case CodeGenOptions::FramePointerKind::NonLeaf:
FpKind = "non-leaf";
break;
case CodeGenOptions::FramePointerKind::All:
FpKind = "all";
break;
}
FuncAttrs.addAttribute("frame-pointer", FpKind);
FuncAttrs.addAttribute("less-precise-fpmad",
llvm::toStringRef(CodeGenOpts.LessPreciseFPMAD));
if (CodeGenOpts.NullPointerIsValid)
FuncAttrs.addAttribute(llvm::Attribute::NullPointerIsValid);
if (CodeGenOpts.FPDenormalMode != llvm::DenormalMode::getIEEE())
FuncAttrs.addAttribute("denormal-fp-math",
CodeGenOpts.FPDenormalMode.str());
if (CodeGenOpts.FP32DenormalMode != CodeGenOpts.FPDenormalMode) {
FuncAttrs.addAttribute(
"denormal-fp-math-f32",
CodeGenOpts.FP32DenormalMode.str());
}
FuncAttrs.addAttribute("no-trapping-math",
llvm::toStringRef(LangOpts.getFPExceptionMode() ==
LangOptions::FPE_Ignore));
// Strict (compliant) code is the default, so only add this attribute to
// indicate that we are trying to workaround a problem case.
if (!CodeGenOpts.StrictFloatCastOverflow)
FuncAttrs.addAttribute("strict-float-cast-overflow", "false");
// TODO: Are these all needed?
// unsafe/inf/nan/nsz are handled by instruction-level FastMathFlags.
FuncAttrs.addAttribute("no-infs-fp-math",
llvm::toStringRef(LangOpts.NoHonorInfs));
FuncAttrs.addAttribute("no-nans-fp-math",
llvm::toStringRef(LangOpts.NoHonorNaNs));
FuncAttrs.addAttribute("unsafe-fp-math",
llvm::toStringRef(LangOpts.UnsafeFPMath));
FuncAttrs.addAttribute("use-soft-float",
llvm::toStringRef(CodeGenOpts.SoftFloat));
FuncAttrs.addAttribute("stack-protector-buffer-size",
llvm::utostr(CodeGenOpts.SSPBufferSize));
FuncAttrs.addAttribute("no-signed-zeros-fp-math",
llvm::toStringRef(LangOpts.NoSignedZero));
// TODO: Reciprocal estimate codegen options should apply to instructions?
const std::vector<std::string> &Recips = CodeGenOpts.Reciprocals;
if (!Recips.empty())
FuncAttrs.addAttribute("reciprocal-estimates",
llvm::join(Recips, ","));
if (!CodeGenOpts.PreferVectorWidth.empty() &&
CodeGenOpts.PreferVectorWidth != "none")
FuncAttrs.addAttribute("prefer-vector-width",
CodeGenOpts.PreferVectorWidth);
if (CodeGenOpts.StackRealignment)
FuncAttrs.addAttribute("stackrealign");
if (CodeGenOpts.Backchain)
FuncAttrs.addAttribute("backchain");
if (CodeGenOpts.EnableSegmentedStacks)
FuncAttrs.addAttribute("split-stack");
if (CodeGenOpts.SpeculativeLoadHardening)
FuncAttrs.addAttribute(llvm::Attribute::SpeculativeLoadHardening);
}
if (getLangOpts().assumeFunctionsAreConvergent()) {
// Conservatively, mark all functions and calls in CUDA and OpenCL as
// convergent (meaning, they may call an intrinsically convergent op, such
// as __syncthreads() / barrier(), and so can't have certain optimizations
// applied around them). LLVM will remove this attribute where it safely
// can.
FuncAttrs.addAttribute(llvm::Attribute::Convergent);
}
if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice) {
// Exceptions aren't supported in CUDA device code.
FuncAttrs.addAttribute(llvm::Attribute::NoUnwind);
}
for (StringRef Attr : CodeGenOpts.DefaultFunctionAttrs) {
StringRef Var, Value;
std::tie(Var, Value) = Attr.split('=');
FuncAttrs.addAttribute(Var, Value);
}
}
void CodeGenModule::addDefaultFunctionDefinitionAttributes(llvm::Function &F) {
llvm::AttrBuilder FuncAttrs;
getDefaultFunctionAttributes(F.getName(), F.hasOptNone(),
/* AttrOnCallSite = */ false, FuncAttrs);
// TODO: call GetCPUAndFeaturesAttributes?
F.addAttributes(llvm::AttributeList::FunctionIndex, FuncAttrs);
}
void CodeGenModule::addDefaultFunctionDefinitionAttributes(
llvm::AttrBuilder &attrs) {
getDefaultFunctionAttributes(/*function name*/ "", /*optnone*/ false,
/*for call*/ false, attrs);
GetCPUAndFeaturesAttributes(GlobalDecl(), attrs);
}
static void addNoBuiltinAttributes(llvm::AttrBuilder &FuncAttrs,
const LangOptions &LangOpts,
const NoBuiltinAttr *NBA = nullptr) {
auto AddNoBuiltinAttr = [&FuncAttrs](StringRef BuiltinName) {
SmallString<32> AttributeName;
AttributeName += "no-builtin-";
AttributeName += BuiltinName;
FuncAttrs.addAttribute(AttributeName);
};
// First, handle the language options passed through -fno-builtin.
if (LangOpts.NoBuiltin) {
// -fno-builtin disables them all.
FuncAttrs.addAttribute("no-builtins");
return;
}
// Then, add attributes for builtins specified through -fno-builtin-<name>.
llvm::for_each(LangOpts.NoBuiltinFuncs, AddNoBuiltinAttr);
// Now, let's check the __attribute__((no_builtin("...")) attribute added to
// the source.
if (!NBA)
return;
// If there is a wildcard in the builtin names specified through the
// attribute, disable them all.
if (llvm::is_contained(NBA->builtinNames(), "*")) {
FuncAttrs.addAttribute("no-builtins");
return;
}
// And last, add the rest of the builtin names.
llvm::for_each(NBA->builtinNames(), AddNoBuiltinAttr);
}
/// Construct the IR attribute list of a function or call.
///
/// When adding an attribute, please consider where it should be handled:
///
/// - getDefaultFunctionAttributes is for attributes that are essentially
/// part of the global target configuration (but perhaps can be
/// overridden on a per-function basis). Adding attributes there
/// will cause them to also be set in frontends that build on Clang's
/// target-configuration logic, as well as for code defined in library
/// modules such as CUDA's libdevice.
///
/// - ConstructAttributeList builds on top of getDefaultFunctionAttributes
/// and adds declaration-specific, convention-specific, and
/// frontend-specific logic. The last is of particular importance:
/// attributes that restrict how the frontend generates code must be
/// added here rather than getDefaultFunctionAttributes.
///
void CodeGenModule::ConstructAttributeList(
StringRef Name, const CGFunctionInfo &FI, CGCalleeInfo CalleeInfo,
llvm::AttributeList &AttrList, unsigned &CallingConv, bool AttrOnCallSite) {
llvm::AttrBuilder FuncAttrs;
llvm::AttrBuilder RetAttrs;
// Collect function IR attributes from the CC lowering.
// We'll collect the paramete and result attributes later.
CallingConv = FI.getEffectiveCallingConvention();
if (FI.isNoReturn())
FuncAttrs.addAttribute(llvm::Attribute::NoReturn);
if (FI.isCmseNSCall())
FuncAttrs.addAttribute("cmse_nonsecure_call");
// Collect function IR attributes from the callee prototype if we have one.
AddAttributesFromFunctionProtoType(getContext(), FuncAttrs,
CalleeInfo.getCalleeFunctionProtoType());
const Decl *TargetDecl = CalleeInfo.getCalleeDecl().getDecl();
bool HasOptnone = false;
// The NoBuiltinAttr attached to the target FunctionDecl.
const NoBuiltinAttr *NBA = nullptr;
// Collect function IR attributes based on declaration-specific
// information.
// 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<ColdAttr>())
FuncAttrs.addAttribute(llvm::Attribute::Cold);
if (TargetDecl->hasAttr<HotAttr>())
FuncAttrs.addAttribute(llvm::Attribute::Hot);
if (TargetDecl->hasAttr<NoDuplicateAttr>())
FuncAttrs.addAttribute(llvm::Attribute::NoDuplicate);
if (TargetDecl->hasAttr<ConvergentAttr>())
FuncAttrs.addAttribute(llvm::Attribute::Convergent);
if (const FunctionDecl *Fn = dyn_cast<FunctionDecl>(TargetDecl)) {
AddAttributesFromFunctionProtoType(
getContext(), FuncAttrs, Fn->getType()->getAs<FunctionProtoType>());
if (AttrOnCallSite && Fn->isReplaceableGlobalAllocationFunction()) {
// A sane operator new returns a non-aliasing pointer.
auto Kind = Fn->getDeclName().getCXXOverloadedOperator();
if (getCodeGenOpts().AssumeSaneOperatorNew &&
(Kind == OO_New || Kind == OO_Array_New))
RetAttrs.addAttribute(llvm::Attribute::NoAlias);
}
const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Fn);
const bool IsVirtualCall = MD && MD->isVirtual();
// Don't use [[noreturn]], _Noreturn or [[no_builtin]] for a call to a
// virtual function. These attributes are not inherited by overloads.
if (!(AttrOnCallSite && IsVirtualCall)) {
if (Fn->isNoReturn())
FuncAttrs.addAttribute(llvm::Attribute::NoReturn);
NBA = Fn->getAttr<NoBuiltinAttr>();
}
// Only place nomerge attribute on call sites, never functions. This
// allows it to work on indirect virtual function calls.
if (AttrOnCallSite && TargetDecl->hasAttr<NoMergeAttr>())
FuncAttrs.addAttribute(llvm::Attribute::NoMerge);
}
// 'const', 'pure' and 'noalias' attributed functions are also nounwind.
if (TargetDecl->hasAttr<ConstAttr>()) {
FuncAttrs.addAttribute(llvm::Attribute::ReadNone);
FuncAttrs.addAttribute(llvm::Attribute::NoUnwind);
// gcc specifies that 'const' functions have greater restrictions than
// 'pure' functions, so they also cannot have infinite loops.
FuncAttrs.addAttribute(llvm::Attribute::WillReturn);
} else if (TargetDecl->hasAttr<PureAttr>()) {
FuncAttrs.addAttribute(llvm::Attribute::ReadOnly);
FuncAttrs.addAttribute(llvm::Attribute::NoUnwind);
// gcc specifies that 'pure' functions cannot have infinite loops.
FuncAttrs.addAttribute(llvm::Attribute::WillReturn);
} else if (TargetDecl->hasAttr<NoAliasAttr>()) {
FuncAttrs.addAttribute(llvm::Attribute::ArgMemOnly);
FuncAttrs.addAttribute(llvm::Attribute::NoUnwind);
}
if (TargetDecl->hasAttr<RestrictAttr>())
RetAttrs.addAttribute(llvm::Attribute::NoAlias);
if (TargetDecl->hasAttr<ReturnsNonNullAttr>() &&
!CodeGenOpts.NullPointerIsValid)
RetAttrs.addAttribute(llvm::Attribute::NonNull);
if (TargetDecl->hasAttr<AnyX86NoCallerSavedRegistersAttr>())
FuncAttrs.addAttribute("no_caller_saved_registers");
if (TargetDecl->hasAttr<AnyX86NoCfCheckAttr>())
FuncAttrs.addAttribute(llvm::Attribute::NoCfCheck);
if (TargetDecl->hasAttr<LeafAttr>())
FuncAttrs.addAttribute(llvm::Attribute::NoCallback);
HasOptnone = TargetDecl->hasAttr<OptimizeNoneAttr>();
if (auto *AllocSize = TargetDecl->getAttr<AllocSizeAttr>()) {
Optional<unsigned> NumElemsParam;
if (AllocSize->getNumElemsParam().isValid())
NumElemsParam = AllocSize->getNumElemsParam().getLLVMIndex();
FuncAttrs.addAllocSizeAttr(AllocSize->getElemSizeParam().getLLVMIndex(),
NumElemsParam);
}
if (TargetDecl->hasAttr<OpenCLKernelAttr>()) {
if (getLangOpts().OpenCLVersion <= 120) {
// OpenCL v1.2 Work groups are always uniform
FuncAttrs.addAttribute("uniform-work-group-size", "true");
} else {
// OpenCL v2.0 Work groups may be whether uniform or not.
// '-cl-uniform-work-group-size' compile option gets a hint
// to the compiler that the global work-size be a multiple of
// the work-group size specified to clEnqueueNDRangeKernel
// (i.e. work groups are uniform).
FuncAttrs.addAttribute("uniform-work-group-size",
llvm::toStringRef(CodeGenOpts.UniformWGSize));
}
}
std::string AssumptionValueStr;
for (AssumptionAttr *AssumptionA :
TargetDecl->specific_attrs<AssumptionAttr>()) {
std::string AS = AssumptionA->getAssumption().str();
if (!AS.empty() && !AssumptionValueStr.empty())
AssumptionValueStr += ",";
AssumptionValueStr += AS;
}
if (!AssumptionValueStr.empty())
FuncAttrs.addAttribute(llvm::AssumptionAttrKey, AssumptionValueStr);
}
// Attach "no-builtins" attributes to:
// * call sites: both `nobuiltin` and "no-builtins" or "no-builtin-<name>".
// * definitions: "no-builtins" or "no-builtin-<name>" only.
// The attributes can come from:
// * LangOpts: -ffreestanding, -fno-builtin, -fno-builtin-<name>
// * FunctionDecl attributes: __attribute__((no_builtin(...)))
addNoBuiltinAttributes(FuncAttrs, getLangOpts(), NBA);
// Collect function IR attributes based on global settiings.
getDefaultFunctionAttributes(Name, HasOptnone, AttrOnCallSite, FuncAttrs);
// Override some default IR attributes based on declaration-specific
// information.
if (TargetDecl) {
if (TargetDecl->hasAttr<NoSpeculativeLoadHardeningAttr>())
FuncAttrs.removeAttribute(llvm::Attribute::SpeculativeLoadHardening);
if (TargetDecl->hasAttr<SpeculativeLoadHardeningAttr>())
FuncAttrs.addAttribute(llvm::Attribute::SpeculativeLoadHardening);
if (TargetDecl->hasAttr<NoSplitStackAttr>())
FuncAttrs.removeAttribute("split-stack");
// Add NonLazyBind attribute to function declarations when -fno-plt
// is used.
// FIXME: what if we just haven't processed the function definition
// yet, or if it's an external definition like C99 inline?
if (CodeGenOpts.NoPLT) {
if (auto *Fn = dyn_cast<FunctionDecl>(TargetDecl)) {
if (!Fn->isDefined() && !AttrOnCallSite) {
FuncAttrs.addAttribute(llvm::Attribute::NonLazyBind);
}
}
}
}
// Collect non-call-site function IR attributes from declaration-specific
// information.
if (!AttrOnCallSite) {
if (TargetDecl && TargetDecl->hasAttr<CmseNSEntryAttr>())
FuncAttrs.addAttribute("cmse_nonsecure_entry");
// Whether tail calls are enabled.
auto shouldDisableTailCalls = [&] {
// Should this be honored in getDefaultFunctionAttributes?
if (CodeGenOpts.DisableTailCalls)
return true;
if (!TargetDecl)
return false;
if (TargetDecl->hasAttr<DisableTailCallsAttr>() ||
TargetDecl->hasAttr<AnyX86InterruptAttr>())
return true;
if (CodeGenOpts.NoEscapingBlockTailCalls) {
if (const auto *BD = dyn_cast<BlockDecl>(TargetDecl))
if (!BD->doesNotEscape())
return true;
}
return false;
};
FuncAttrs.addAttribute("disable-tail-calls",
llvm::toStringRef(shouldDisableTailCalls()));
// CPU/feature overrides. addDefaultFunctionDefinitionAttributes
// handles these separately to set them based on the global defaults.
GetCPUAndFeaturesAttributes(CalleeInfo.getCalleeDecl(), FuncAttrs);
}
// Collect attributes from arguments and return values.
ClangToLLVMArgMapping IRFunctionArgs(getContext(), FI);
QualType RetTy = FI.getReturnType();
const ABIArgInfo &RetAI = FI.getReturnInfo();
switch (RetAI.getKind()) {
case ABIArgInfo::Extend:
if (RetAI.isSignExt())
RetAttrs.addAttribute(llvm::Attribute::SExt);
else
RetAttrs.addAttribute(llvm::Attribute::ZExt);
LLVM_FALLTHROUGH;
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::CoerceAndExpand:
break;
case ABIArgInfo::Expand:
case ABIArgInfo::IndirectAliased:
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(
getMinimumObjectSize(PTy).getQuantity());
if (getContext().getTargetAddressSpace(PTy) == 0 &&
!CodeGenOpts.NullPointerIsValid)
RetAttrs.addAttribute(llvm::Attribute::NonNull);
if (PTy->isObjectType()) {
llvm::Align Alignment =
getNaturalPointeeTypeAlignment(RetTy).getAsAlign();
RetAttrs.addAlignmentAttr(Alignment);
}
}
bool hasUsedSRet = false;
SmallVector<llvm::AttributeSet, 4> ArgAttrs(IRFunctionArgs.totalIRArgs());
// Attach attributes to sret.
if (IRFunctionArgs.hasSRetArg()) {
llvm::AttrBuilder SRETAttrs;
SRETAttrs.addStructRetAttr(getTypes().ConvertTypeForMem(RetTy));
hasUsedSRet = true;
if (RetAI.getInReg())
SRETAttrs.addAttribute(llvm::Attribute::InReg);
SRETAttrs.addAlignmentAttr(RetAI.getIndirectAlign().getQuantity());
ArgAttrs[IRFunctionArgs.getSRetArgNo()] =
llvm::AttributeSet::get(getLLVMContext(), SRETAttrs);
}
// Attach attributes to inalloca argument.
if (IRFunctionArgs.hasInallocaArg()) {
llvm::AttrBuilder Attrs;
Attrs.addAttribute(llvm::Attribute::InAlloca);
ArgAttrs[IRFunctionArgs.getInallocaArgNo()] =
llvm::AttributeSet::get(getLLVMContext(), Attrs);
}
// Apply `nonnull` and `dereferencable(N)` to the `this` argument.
if (FI.isInstanceMethod() && !IRFunctionArgs.hasInallocaArg() &&
!FI.arg_begin()->type->isVoidPointerType()) {
auto IRArgs = IRFunctionArgs.getIRArgs(0);
assert(IRArgs.second == 1 && "Expected only a single `this` pointer.");
llvm::AttrBuilder Attrs;
if (!CodeGenOpts.NullPointerIsValid &&
getContext().getTargetAddressSpace(FI.arg_begin()->type) == 0) {
Attrs.addAttribute(llvm::Attribute::NonNull);
Attrs.addDereferenceableAttr(
getMinimumObjectSize(
FI.arg_begin()->type.castAs<PointerType>()->getPointeeType())
.getQuantity());
} else {
// FIXME dereferenceable should be correct here, regardless of
// NullPointerIsValid. However, dereferenceable currently does not always
// respect NullPointerIsValid and may imply nonnull and break the program.
// See https://reviews.llvm.org/D66618 for discussions.
Attrs.addDereferenceableOrNullAttr(
getMinimumObjectSize(
FI.arg_begin()->type.castAs<PointerType>()->getPointeeType())
.getQuantity());
}
ArgAttrs[IRArgs.first] = llvm::AttributeSet::get(getLLVMContext(), 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()) {
ArgAttrs[IRFunctionArgs.getPaddingArgNo(ArgNo)] =
llvm::AttributeSet::get(
getLLVMContext(),
llvm::AttrBuilder().addAttribute(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 (AI.isSignExt())
Attrs.addAttribute(llvm::Attribute::SExt);
else
Attrs.addAttribute(llvm::Attribute::ZExt);
LLVM_FALLTHROUGH;
case ABIArgInfo::Direct:
if (ArgNo == 0 && FI.isChainCall())
Attrs.addAttribute(llvm::Attribute::Nest);
else if (AI.getInReg())
Attrs.addAttribute(llvm::Attribute::InReg);
break;
case ABIArgInfo::Indirect: {
if (AI.getInReg())
Attrs.addAttribute(llvm::Attribute::InReg);
if (AI.getIndirectByVal())
Attrs.addByValAttr(getTypes().ConvertTypeForMem(ParamType));
auto *Decl = ParamType->getAsRecordDecl();
if (CodeGenOpts.PassByValueIsNoAlias && Decl &&
Decl->getArgPassingRestrictions() == RecordDecl::APK_CanPassInRegs)
// When calling the function, the pointer passed in will be the only
// reference to the underlying object. Mark it accordingly.
Attrs.addAttribute(llvm::Attribute::NoAlias);
// TODO: We could add the byref attribute if not byval, but it would
// require updating many testcases.
CharUnits Align = AI.getIndirectAlign();
// In a byval argument, it is important that the required
// alignment of the type is honored, as LLVM might be creating a
// *new* stack object, and needs to know what alignment to give
// it. (Sometimes it can deduce a sensible alignment on its own,
// but not if clang decides it must emit a packed struct, or the
// user specifies increased alignment requirements.)
//
// This is different from indirect *not* byval, where the object
// exists already, and the align attribute is purely
// informative.
assert(!Align.isZero());
// For now, only add this when we have a byval argument.
// TODO: be less lazy about updating test cases.
if (AI.getIndirectByVal())
Attrs.addAlignmentAttr(Align.getQuantity());
// byval disables readnone and readonly.
FuncAttrs.removeAttribute(llvm::Attribute::ReadOnly)
.removeAttribute(llvm::Attribute::ReadNone);
break;
}
case ABIArgInfo::IndirectAliased: {
CharUnits Align = AI.getIndirectAlign();
Attrs.addByRefAttr(getTypes().ConvertTypeForMem(ParamType));
Attrs.addAlignmentAttr(Align.getQuantity());
break;
}
case ABIArgInfo::Ignore:
case ABIArgInfo::Expand:
case ABIArgInfo::CoerceAndExpand:
break;
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(
getMinimumObjectSize(PTy).getQuantity());
if (getContext().getTargetAddressSpace(PTy) == 0 &&
!CodeGenOpts.NullPointerIsValid)
Attrs.addAttribute(llvm::Attribute::NonNull);
if (PTy->isObjectType()) {
llvm::Align Alignment =
getNaturalPointeeTypeAlignment(ParamType).getAsAlign();
Attrs.addAlignmentAttr(Alignment);
}
}
switch (FI.getExtParameterInfo(ArgNo).getABI()) {
case ParameterABI::Ordinary:
break;
case ParameterABI::SwiftIndirectResult: {
// Add 'sret' if we haven't already used it for something, but
// only if the result is void.
if (!hasUsedSRet && RetTy->isVoidType()) {
Attrs.addStructRetAttr(getTypes().ConvertTypeForMem(ParamType));
hasUsedSRet = true;
}
// Add 'noalias' in either case.
Attrs.addAttribute(llvm::Attribute::NoAlias);
// Add 'dereferenceable' and 'alignment'.
auto PTy = ParamType->getPointeeType();
if (!PTy->isIncompleteType() && PTy->isConstantSizeType()) {
auto info = getContext().getTypeInfoInChars(PTy);
Attrs.addDereferenceableAttr(info.Width.getQuantity());
Attrs.addAlignmentAttr(info.Align.getAsAlign());
}
break;
}
case ParameterABI::SwiftErrorResult:
Attrs.addAttribute(llvm::Attribute::SwiftError);
break;
case ParameterABI::SwiftContext:
Attrs.addAttribute(llvm::Attribute::SwiftSelf);
break;
}
if (FI.getExtParameterInfo(ArgNo).isNoEscape())
Attrs.addAttribute(llvm::Attribute::NoCapture);
if (Attrs.hasAttributes()) {
unsigned FirstIRArg, NumIRArgs;
std::tie(FirstIRArg, NumIRArgs) = IRFunctionArgs.getIRArgs(ArgNo);
for (unsigned i = 0; i < NumIRArgs; i++)
ArgAttrs[FirstIRArg + i] =
llvm::AttributeSet::get(getLLVMContext(), Attrs);
}
}
assert(ArgNo == FI.arg_size());
AttrList = llvm::AttributeList::get(
getLLVMContext(), llvm::AttributeSet::get(getLLVMContext(), FuncAttrs),
llvm::AttributeSet::get(getLLVMContext(), RetAttrs), ArgAttrs);
}
/// 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;
}
namespace {
struct CopyBackSwiftError final : EHScopeStack::Cleanup {
Address Temp;
Address Arg;
CopyBackSwiftError(Address temp, Address arg) : Temp(temp), Arg(arg) {}
void Emit(CodeGenFunction &CGF, Flags flags) override {
llvm::Value *errorValue = CGF.Builder.CreateLoad(Temp);
CGF.Builder.CreateStore(errorValue, Arg);
}
};
}
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);
assert(Fn->arg_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.
Address ArgStruct = Address::invalid();
if (IRFunctionArgs.hasInallocaArg()) {
ArgStruct = Address(Fn->getArg(IRFunctionArgs.getInallocaArgNo()),
FI.getArgStructAlignment());
assert(ArgStruct.getType() == FI.getArgStruct()->getPointerTo());
}
// Name the struct return parameter.
if (IRFunctionArgs.hasSRetArg()) {
auto AI = Fn->getArg(IRFunctionArgs.getSRetArgNo());
AI->setName("agg.result");
AI->addAttr(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.
SmallVector<ParamValue, 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;
const ABIArgInfo &ArgI = info_it->info;
bool isPromoted =
isa<ParmVarDecl>(Arg) && cast<ParmVarDecl>(Arg)->isKNRPromoted();
// We are converting from ABIArgInfo type to VarDecl type directly, unless
// the parameter is promoted. In this case we convert to
// CGFunctionInfo::ArgInfo type with subsequent argument demotion.
QualType Ty = isPromoted ? info_it->type : Arg->getType();
assert(hasScalarEvaluationKind(Ty) ==
hasScalarEvaluationKind(Arg->getType()));
unsigned FirstIRArg, NumIRArgs;
std::tie(FirstIRArg, NumIRArgs) = IRFunctionArgs.getIRArgs(ArgNo);
switch (ArgI.getKind()) {
case ABIArgInfo::InAlloca: {
assert(NumIRArgs == 0);
auto FieldIndex = ArgI.getInAllocaFieldIndex();
Address V =
Builder.CreateStructGEP(ArgStruct, FieldIndex, Arg->getName());
if (ArgI.getInAllocaIndirect())
V = Address(Builder.CreateLoad(V),
getContext().getTypeAlignInChars(Ty));
ArgVals.push_back(ParamValue::forIndirect(V));
break;
}
case ABIArgInfo::Indirect:
case ABIArgInfo::IndirectAliased: {
assert(NumIRArgs == 1);
Address ParamAddr =
Address(Fn->getArg(FirstIRArg), ArgI.getIndirectAlign());
if (!hasScalarEvaluationKind(Ty)) {
// Aggregates and complex variables are accessed by reference. All we
// need to do is realign the value, if requested. Also, if the address
// may be aliased, copy it to ensure that the parameter variable is
// mutable and has a unique adress, as C requires.
Address V = ParamAddr;
if (ArgI.getIndirectRealign() || ArgI.isIndirectAliased()) {
Address 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.
CharUnits Size = getContext().getTypeSizeInChars(Ty);
Builder.CreateMemCpy(
AlignedTemp.getPointer(), AlignedTemp.getAlignment().getAsAlign(),
ParamAddr.getPointer(), ParamAddr.getAlignment().getAsAlign(),
llvm::ConstantInt::get(IntPtrTy, Size.getQuantity()));
V = AlignedTemp;
}
ArgVals.push_back(ParamValue::forIndirect(V));
} else {
// Load scalar value from indirect argument.
llvm::Value *V =
EmitLoadOfScalar(ParamAddr, false, Ty, Arg->getBeginLoc());
if (isPromoted)
V = emitArgumentDemotion(*this, Arg, V);
ArgVals.push_back(ParamValue::forDirect(V));
}
break;
}
case ABIArgInfo::Extend:
case ABIArgInfo::Direct: {
auto AI = Fn->getArg(FirstIRArg);
llvm::Type *LTy = ConvertType(Arg->getType());
// Prepare parameter attributes. So far, only attributes for pointer
// parameters are prepared. See
// http://llvm.org/docs/LangRef.html#paramattrs.
if (ArgI.getDirectOffset() == 0 && LTy->isPointerTy() &&
ArgI.getCoerceToType()->isPointerTy()) {
assert(NumIRArgs == 1);
if (const ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(Arg)) {
// Set `nonnull` attribute if any.
if (getNonNullAttr(CurCodeDecl, PVD, PVD->getType(),
PVD->getFunctionScopeIndex()) &&
!CGM.getCodeGenOpts().NullPointerIsValid)
AI->addAttr(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();
llvm::Align Alignment =
CGM.getNaturalTypeAlignment(ETy).getAsAlign();
AI->addAttrs(llvm::AttrBuilder().addAlignmentAttr(Alignment));
uint64_t ArrSize = ArrTy->getSize().getZExtValue();
if (!ETy->isIncompleteType() && ETy->isConstantSizeType() &&
ArrSize) {
llvm::AttrBuilder Attrs;
Attrs.addDereferenceableAttr(
getContext().getTypeSizeInChars(ETy).getQuantity() *
ArrSize);
AI->addAttrs(Attrs);
} else if (getContext().getTargetInfo().getNullPointerValue(
ETy.getAddressSpace()) == 0 &&
!CGM.getCodeGenOpts().NullPointerIsValid) {
AI->addAttr(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) {
QualType ETy = ArrTy->getElementType();
llvm::Align Alignment =
CGM.getNaturalTypeAlignment(ETy).getAsAlign();
AI->addAttrs(llvm::AttrBuilder().addAlignmentAttr(Alignment));
if (!getContext().getTargetAddressSpace(ETy) &&
!CGM.getCodeGenOpts().NullPointerIsValid)
AI->addAttr(llvm::Attribute::NonNull);
}
}
// Set `align` attribute if any.
const auto *AVAttr = PVD->getAttr<AlignValueAttr>();
if (!AVAttr)
if (const auto *TOTy = dyn_cast<TypedefType>(OTy))
AVAttr = TOTy->getDecl()->getAttr<AlignValueAttr>();
if (AVAttr && !SanOpts.has(SanitizerKind::Alignment)) {
// If alignment-assumption sanitizer is enabled, we do *not* add
// alignment attribute here, but emit normal alignment assumption,
// so the UBSAN check could function.
llvm::ConstantInt *AlignmentCI =
cast<llvm::ConstantInt>(EmitScalarExpr(AVAttr->getAlignment()));
unsigned AlignmentInt =
AlignmentCI->getLimitedValue(llvm::Value::MaximumAlignment);
if (AI->getParamAlign().valueOrOne() < AlignmentInt) {
AI->removeAttr(llvm::Attribute::AttrKind::Alignment);
AI->addAttrs(llvm::AttrBuilder().addAlignmentAttr(
llvm::Align(AlignmentInt)));
}
}
}
// Set 'noalias' if an argument type has the `restrict` qualifier.
if (Arg->getType().isRestrictQualified())
AI->addAttr(llvm::Attribute::NoAlias);
}
// Prepare the argument value. 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);
// LLVM expects swifterror parameters to be used in very restricted
// ways. Copy the value into a less-restricted temporary.
llvm::Value *V = AI;
if (FI.getExtParameterInfo(ArgNo).getABI()
== ParameterABI::SwiftErrorResult) {
QualType pointeeTy = Ty->getPointeeType();
assert(pointeeTy->isPointerType());
Address temp =
CreateMemTemp(pointeeTy, getPointerAlign(), "swifterror.temp");
Address arg = Address(V, getContext().getTypeAlignInChars(pointeeTy));
llvm::Value *incomingErrorValue = Builder.CreateLoad(arg);
Builder.CreateStore(incomingErrorValue, temp);
V = temp.getPointer();
// Push a cleanup to copy the value back at the end of the function.
// The convention does not guarantee that the value will be written
// back if the function exits with an unwind exception.
EHStack.pushCleanup<CopyBackSwiftError>(NormalCleanup, temp, arg);
}
// 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);
// 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(ParamValue::forDirect(V));
break;
}
// VLST arguments are coerced to VLATs at the function boundary for
// ABI consistency. If this is a VLST that was coerced to
// a VLAT at the function boundary and the types match up, use
// llvm.experimental.vector.extract to convert back to the original
// VLST.
if (auto *VecTyTo = dyn_cast<llvm::FixedVectorType>(ConvertType(Ty))) {
auto *Coerced = Fn->getArg(FirstIRArg);
if (auto *VecTyFrom =
dyn_cast<llvm::ScalableVectorType>(Coerced->getType())) {
if (VecTyFrom->getElementType() == VecTyTo->getElementType()) {
llvm::Value *Zero = llvm::Constant::getNullValue(CGM.Int64Ty);
assert(NumIRArgs == 1);
Coerced->setName(Arg->getName() + ".coerce");
ArgVals.push_back(ParamValue::forDirect(Builder.CreateExtractVector(
VecTyTo, Coerced, Zero, "castFixedSve")));
break;
}
}
}
Address Alloca = CreateMemTemp(Ty, getContext().getDeclAlign(Arg),
Arg->getName());
// Pointer to store into.
Address Ptr = emitAddressAtOffset(*this, Alloca, ArgI);
// 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 = Ptr.getElementType();
uint64_t DstSize = CGM.getDataLayout().getTypeAllocSize(DstTy);
Address AddrToStoreInto = Address::invalid();
if (SrcSize <= DstSize) {
AddrToStoreInto = Builder.CreateElementBitCast(Ptr, STy);
} else {
AddrToStoreInto =
CreateTempAlloca(STy, Alloca.getAlignment(), "coerce");
}
assert(STy->getNumElements() == NumIRArgs);
for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
auto AI = Fn->getArg(FirstIRArg + i);
AI->setName(Arg->getName() + ".coerce" + Twine(i));
Address EltPtr = Builder.CreateStructGEP(AddrToStoreInto, i);
Builder.CreateStore(AI, EltPtr);
}
if (SrcSize > DstSize) {
Builder.CreateMemCpy(Ptr, AddrToStoreInto, DstSize);
}
} else {
// Simple case, just do a coerced store of the argument into the alloca.
assert(NumIRArgs == 1);
auto AI = Fn->getArg(FirstIRArg);
AI->setName(Arg->getName() + ".coerce");
CreateCoercedStore(AI, Ptr, /*DstIsVolatile=*/false, *this);
}
// Match to what EmitParmDecl is expecting for this type.
if (CodeGenFunction::hasScalarEvaluationKind(Ty)) {
llvm::Value *V =
EmitLoadOfScalar(Alloca, false, Ty, Arg->getBeginLoc());
if (isPromoted)
V = emitArgumentDemotion(*this, Arg, V);
ArgVals.push_back(ParamValue::forDirect(V));
} else {
ArgVals.push_back(ParamValue::forIndirect(Alloca));
}
break;
}
case ABIArgInfo::CoerceAndExpand: {
// Reconstruct into a temporary.
Address alloca = CreateMemTemp(Ty, getContext().getDeclAlign(Arg));
ArgVals.push_back(ParamValue::forIndirect(alloca));
auto coercionType = ArgI.getCoerceAndExpandType();
alloca = Builder.CreateElementBitCast(alloca, coercionType);
unsigned argIndex = FirstIRArg;
for (unsigned i = 0, e = coercionType->getNumElements(); i != e; ++i) {
llvm::Type *eltType = coercionType->getElementType(i);
if (ABIArgInfo::isPaddingForCoerceAndExpand(eltType))
continue;
auto eltAddr = Builder.CreateStructGEP(alloca, i);
auto elt = Fn->getArg(argIndex++);
Builder.CreateStore(elt, eltAddr);
}
assert(argIndex == FirstIRArg + NumIRArgs);
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.
Address Alloca = CreateMemTemp(Ty, getContext().getDeclAlign(Arg));
LValue LV = MakeAddrLValue(Alloca, Ty);
ArgVals.push_back(ParamValue::forIndirect(Alloca));
auto FnArgIter = Fn->arg_begin() + FirstIRArg;
ExpandTypeFromArgs(Ty, LV, FnArgIter);
assert(FnArgIter == Fn->arg_begin() + FirstIRArg + NumIRArgs);
for (unsigned i = 0, e = NumIRArgs; i != e; ++i) {
auto AI = Fn->getArg(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(ParamValue::forIndirect(CreateMemTemp(Ty)));
} else {
llvm::Value *U = llvm::UndefValue::get(ConvertType(Arg->getType()));
ArgVals.push_back(ParamValue::forDirect(U));
}
break;
}
}
if (getTarget().getCXXABI().areArgsDestroyedLeftToRightInCallee()) {
for (int I = Args.size() - 1; I >= 0; --I)
EmitParmDecl(*Args[I], ArgVals[I], I + 1);
} else {
for (unsigned I = 0, E = Args.size(); I != E; ++I)
EmitParmDecl(*Args[I], ArgVals[I], 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> InstsToKill;
// 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;
InstsToKill.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->getCalledOperand() == CGF.CGM.getObjCEntrypoints().objc_retain) {
doRetainAutorelease = true;
} else if (call->getCalledOperand() ==
CGF.CGM.getObjCEntrypoints().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.getObjCEntrypoints().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)->getCalledOperand() ==
CGF.CGM.getObjCEntrypoints().retainAutoreleasedReturnValueMarker);
InstsToKill.push_back(prev);
}
} else {
return nullptr;
}
result = call->getArgOperand(0);
InstsToKill.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;
InstsToKill.push_back(bitcast);
result = bitcast->getOperand(0);
}
// Delete all the unnecessary instructions, from latest to earliest.
for (auto *I : InstsToKill)
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->getCalledOperand() !=
CGF.CGM.getObjCEntrypoints().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).getPointer())
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) {
// Check if a User is a store which pointerOperand is the ReturnValue.
// We are looking for stores to the ReturnValue, not for stores of the
// ReturnValue to some other location.
auto GetStoreIfValid = [&CGF](llvm::User *U) -> llvm::StoreInst * {
auto *SI = dyn_cast<llvm::StoreInst>(U);
if (!SI || SI->getPointerOperand() != CGF.ReturnValue.getPointer())
return nullptr;
// These aren't actually possible for non-coerced returns, and we
// only care about non-coerced returns on this code path.
assert(!SI->isAtomic() && !SI->isVolatile());
return SI;
};
// 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.getPointer()->hasOneUse()) {
llvm::BasicBlock *IP = CGF.Builder.GetInsertBlock();
if (IP->empty()) return nullptr;
llvm::Instruction *I = &IP->back();
// Skip lifetime markers
for (llvm::BasicBlock::reverse_iterator II = IP->rbegin(),
IE = IP->rend();
II != IE; ++II) {
if (llvm::IntrinsicInst *Intrinsic =
dyn_cast<llvm::IntrinsicInst>(&*II)) {
if (Intrinsic->getIntrinsicID() == llvm::Intrinsic::lifetime_end) {
const llvm::Value *CastAddr = Intrinsic->getArgOperand(1);
++II;
if (II == IE)
break;
if (isa<llvm::BitCastInst>(&*II) && (CastAddr == &*II))
continue;
}
}
I = &*II;
break;
}
return GetStoreIfValid(I);
}
llvm::StoreInst *store =
GetStoreIfValid(CGF.ReturnValue.getPointer()->user_back());
if (!store) return nullptr;
// 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;
}
// Helper functions for EmitCMSEClearRecord
// Set the bits corresponding to a field having width `BitWidth` and located at
// offset `BitOffset` (from the least significant bit) within a storage unit of
// `Bits.size()` bytes. Each element of `Bits` corresponds to one target byte.
// Use little-endian layout, i.e.`Bits[0]` is the LSB.
static void setBitRange(SmallVectorImpl<uint64_t> &Bits, int BitOffset,
int BitWidth, int CharWidth) {
assert(CharWidth <= 64);
assert(static_cast<unsigned>(BitWidth) <= Bits.size() * CharWidth);
int Pos = 0;
if (BitOffset >= CharWidth) {
Pos += BitOffset / CharWidth;
BitOffset = BitOffset % CharWidth;
}
const uint64_t Used = (uint64_t(1) << CharWidth) - 1;
if (BitOffset + BitWidth >= CharWidth) {
Bits[Pos++] |= (Used << BitOffset) & Used;
BitWidth -= CharWidth - BitOffset;
BitOffset = 0;
}
while (BitWidth >= CharWidth) {
Bits[Pos++] = Used;
BitWidth -= CharWidth;
}
if (BitWidth > 0)
Bits[Pos++] |= (Used >> (CharWidth - BitWidth)) << BitOffset;
}
// Set the bits corresponding to a field having width `BitWidth` and located at
// offset `BitOffset` (from the least significant bit) within a storage unit of
// `StorageSize` bytes, located at `StorageOffset` in `Bits`. Each element of
// `Bits` corresponds to one target byte. Use target endian layout.
static void setBitRange(SmallVectorImpl<uint64_t> &Bits, int StorageOffset,
int StorageSize, int BitOffset, int BitWidth,
int CharWidth, bool BigEndian) {
SmallVector<uint64_t, 8> TmpBits(StorageSize);
setBitRange(TmpBits, BitOffset, BitWidth, CharWidth);
if (BigEndian)
std::reverse(TmpBits.begin(), TmpBits.end());
for (uint64_t V : TmpBits)
Bits[StorageOffset++] |= V;
}
static void setUsedBits(CodeGenModule &, QualType, int,
SmallVectorImpl<uint64_t> &);
// Set the bits in `Bits`, which correspond to the value representations of
// the actual members of the record type `RTy`. Note that this function does
// not handle base classes, virtual tables, etc, since they cannot happen in
// CMSE function arguments or return. The bit mask corresponds to the target
// memory layout, i.e. it's endian dependent.
static void setUsedBits(CodeGenModule &CGM, const RecordType *RTy, int Offset,
SmallVectorImpl<uint64_t> &Bits) {
ASTContext &Context = CGM.getContext();
int CharWidth = Context.getCharWidth();
const RecordDecl *RD = RTy->getDecl()->getDefinition();
const ASTRecordLayout &ASTLayout = Context.getASTRecordLayout(RD);
const CGRecordLayout &Layout = CGM.getTypes().getCGRecordLayout(RD);
int Idx = 0;
for (auto I = RD->field_begin(), E = RD->field_end(); I != E; ++I, ++Idx) {
const FieldDecl *F = *I;
if (F->isUnnamedBitfield() || F->isZeroLengthBitField(Context) ||
F->getType()->isIncompleteArrayType())
continue;
if (F->isBitField()) {
const CGBitFieldInfo &BFI = Layout.getBitFieldInfo(F);
setBitRange(Bits, Offset + BFI.StorageOffset.getQuantity(),
BFI.StorageSize / CharWidth, BFI.Offset,
BFI.Size, CharWidth,
CGM.getDataLayout().isBigEndian());
continue;
}
setUsedBits(CGM, F->getType(),
Offset + ASTLayout.getFieldOffset(Idx) / CharWidth, Bits);
}
}
// Set the bits in `Bits`, which correspond to the value representations of
// the elements of an array type `ATy`.
static void setUsedBits(CodeGenModule &CGM, const ConstantArrayType *ATy,
int Offset, SmallVectorImpl<uint64_t> &Bits) {
const ASTContext &Context = CGM.getContext();
QualType ETy = Context.getBaseElementType(ATy);
int Size = Context.getTypeSizeInChars(ETy).getQuantity();
SmallVector<uint64_t, 4> TmpBits(Size);
setUsedBits(CGM, ETy, 0, TmpBits);
for (int I = 0, N = Context.getConstantArrayElementCount(ATy); I < N; ++I) {
auto Src = TmpBits.begin();
auto Dst = Bits.begin() + Offset + I * Size;
for (int J = 0; J < Size; ++J)
*Dst++ |= *Src++;
}
}
// Set the bits in `Bits`, which correspond to the value representations of
// the type `QTy`.
static void setUsedBits(CodeGenModule &CGM, QualType QTy, int Offset,
SmallVectorImpl<uint64_t> &Bits) {
if (const auto *RTy = QTy->getAs<RecordType>())
return setUsedBits(CGM, RTy, Offset, Bits);
ASTContext &Context = CGM.getContext();
if (const auto *ATy = Context.getAsConstantArrayType(QTy))
return setUsedBits(CGM, ATy, Offset, Bits);
int Size = Context.getTypeSizeInChars(QTy).getQuantity();
if (Size <= 0)
return;
std::fill_n(Bits.begin() + Offset, Size,
(uint64_t(1) << Context.getCharWidth()) - 1);
}
static uint64_t buildMultiCharMask(const SmallVectorImpl<uint64_t> &Bits,
int Pos, int Size, int CharWidth,
bool BigEndian) {
assert(Size > 0);
uint64_t Mask = 0;
if (BigEndian) {
for (auto P = Bits.begin() + Pos, E = Bits.begin() + Pos + Size; P != E;
++P)
Mask = (Mask << CharWidth) | *P;
} else {
auto P = Bits.begin() + Pos + Size, End = Bits.begin() + Pos;
do
Mask = (Mask << CharWidth) | *--P;
while (P != End);
}
return Mask;
}
// Emit code to clear the bits in a record, which aren't a part of any user
// declared member, when the record is a function return.
llvm::Value *CodeGenFunction::EmitCMSEClearRecord(llvm::Value *Src,
llvm::IntegerType *ITy,
QualType QTy) {
assert(Src->getType() == ITy);
assert(ITy->getScalarSizeInBits() <= 64);
const llvm::DataLayout &DataLayout = CGM.getDataLayout();
int Size = DataLayout.getTypeStoreSize(ITy);
SmallVector<uint64_t, 4> Bits(Size);
setUsedBits(CGM, QTy->castAs<RecordType>(), 0, Bits);
int CharWidth = CGM.getContext().getCharWidth();
uint64_t Mask =
buildMultiCharMask(Bits, 0, Size, CharWidth, DataLayout.isBigEndian());
return Builder.CreateAnd(Src, Mask, "cmse.clear");
}
// Emit code to clear the bits in a record, which aren't a part of any user
// declared member, when the record is a function argument.
llvm::Value *CodeGenFunction::EmitCMSEClearRecord(llvm::Value *Src,
llvm::ArrayType *ATy,
QualType QTy) {
const llvm::DataLayout &DataLayout = CGM.getDataLayout();
int Size = DataLayout.getTypeStoreSize(ATy);
SmallVector<uint64_t, 16> Bits(Size);
setUsedBits(CGM, QTy->castAs<RecordType>(), 0, Bits);
// Clear each element of the LLVM array.
int CharWidth = CGM.getContext().getCharWidth();
int CharsPerElt =
ATy->getArrayElementType()->getScalarSizeInBits() / CharWidth;
int MaskIndex = 0;
llvm::Value *R = llvm::UndefValue::get(ATy);
for (int I = 0, N = ATy->getArrayNumElements(); I != N; ++I) {
uint64_t Mask = buildMultiCharMask(Bits, MaskIndex, CharsPerElt, CharWidth,
DataLayout.isBigEndian());
MaskIndex += CharsPerElt;
llvm::Value *T0 = Builder.CreateExtractValue(Src, I);
llvm::Value *T1 = Builder.CreateAnd(T0, Mask, "cmse.clear");
R = Builder.CreateInsertValue(R, T1, I);
}
return R;
}
void CodeGenFunction::EmitFunctionEpilog(const CGFunctionInfo &FI,
bool EmitRetDbgLoc,
SourceLocation EndLoc) {
if (FI.isNoReturn()) {
// Noreturn functions don't return.
EmitUnreachable(EndLoc);
return;
}
if (CurCodeDecl && CurCodeDecl->hasAttr<NakedAttr>()) {
// Naked functions don't have epilogues.
Builder.CreateUnreachable();
return;
}
// Functions with no result always return void.
if (!ReturnValue.isValid()) {
Builder.CreateRetVoid();
return;
}
llvm::DebugLoc RetDbgLoc;
llvm::Value *RV = nullptr;
QualType RetTy = FI.getReturnType();
const ABIArgInfo &RetAI = FI.getReturnInfo();
switch (RetAI.getKind()) {
case ABIArgInfo::InAlloca:
// Aggregrates get evaluated directly into the destination. Sometimes we
// need to return the sret value in a register, though.
assert(hasAggregateEvaluationKind(RetTy));
if (RetAI.getInAllocaSRet()) {
llvm::Function::arg_iterator EI = CurFn->arg_end();
--EI;
llvm::Value *ArgStruct = &*EI;
llvm::Value *SRet = Builder.CreateStructGEP(
nullptr, ArgStruct, RetAI.getInAllocaFieldIndex());
RV = Builder.CreateAlignedLoad(SRet, getPointerAlign(), "sret");
}
break;
case ABIArgInfo::Indirect: {
auto AI = CurFn->arg_begin();
if (RetAI.isSRetAfterThis())
++AI;
switch (getEvaluationKind(RetTy)) {
case TEK_Complex: {
ComplexPairTy RT =
EmitLoadOfComplex(MakeAddrLValue(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();
// Otherwise, we have to do a simple load.
} else {
RV = Builder.CreateLoad(ReturnValue);
}
} else {
// If the value is offset in memory, apply the offset now.
Address V = emitAddressAtOffset(*this, ReturnValue, RetAI);
RV = CreateCoercedLoad(V, RetAI.getCoerceToType(), *this);
}
// In ARC, end functions that return a retainable type with a call
// to objc_autoreleaseReturnValue.
if (AutoreleaseResult) {
#ifndef NDEBUG
// Type::isObjCRetainabletype has to be called on a QualType that hasn't
// been stripped of the typedefs, so we cannot use RetTy here. Get the
// original return type of FunctionDecl, CurCodeDecl, and BlockDecl from
// CurCodeDecl or BlockInfo.
QualType RT;
if (auto *FD = dyn_cast<FunctionDecl>(CurCodeDecl))
RT = FD->getReturnType();
else if (auto *MD = dyn_cast<ObjCMethodDecl>(CurCodeDecl))
RT = MD->getReturnType();
else if (isa<BlockDecl>(CurCodeDecl))
RT = BlockInfo->BlockExpression->getFunctionType()->getReturnType();
else
llvm_unreachable("Unexpected function/method type");
assert(getLangOpts().ObjCAutoRefCount &&
!FI.isReturnsRetained() &&
RT->isObjCRetainableType());
#endif
RV = emitAutoreleaseOfResult(*this, RV);
}
break;
case ABIArgInfo::Ignore:
break;
case ABIArgInfo::CoerceAndExpand: {
auto coercionType = RetAI.getCoerceAndExpandType();
// Load all of the coerced elements out into results.
llvm::SmallVector<llvm::Value*, 4> results;
Address addr = Builder.CreateElementBitCast(ReturnValue, coercionType);
for (unsigned i = 0, e = coercionType->getNumElements(); i != e; ++i) {
auto coercedEltType = coercionType->getElementType(i);
if (ABIArgInfo::isPaddingForCoerceAndExpand(coercedEltType))
continue;
auto eltAddr = Builder.CreateStructGEP(addr, i);
auto elt = Builder.CreateLoad(eltAddr);
results.push_back(elt);
}
// If we have one result, it's the single direct result type.
if (results.size() == 1) {
RV = results[0];
// Otherwise, we need to make a first-class aggregate.
} else {
// Construct a return type that lacks padding elements.
llvm::Type *returnType = RetAI.getUnpaddedCoerceAndExpandType();
RV = llvm::UndefValue::get(returnType);
for (unsigned i = 0, e = results.size(); i != e; ++i) {
RV = Builder.CreateInsertValue(RV, results[i], i);
}
}
break;
}
case ABIArgInfo::Expand:
case ABIArgInfo::IndirectAliased:
llvm_unreachable("Invalid ABI kind for return argument");
}
llvm::Instruction *Ret;
if (RV) {
if (CurFuncDecl && CurFuncDecl->hasAttr<CmseNSEntryAttr>()) {
// For certain return types, clear padding bits, as they may reveal
// sensitive information.
// Small struct/union types are passed as integers.
auto *ITy = dyn_cast<llvm::IntegerType>(RV->getType());
if (ITy != nullptr && isa<RecordType>(RetTy.getCanonicalType()))
RV = EmitCMSEClearRecord(RV, ITy, RetTy);
}
EmitReturnValueCheck(RV);
Ret = Builder.CreateRet(RV);
} else {
Ret = Builder.CreateRetVoid();
}
if (RetDbgLoc)
Ret->setDebugLoc(std::move(RetDbgLoc));
}
void CodeGenFunction::EmitReturnValueCheck(llvm::Value *RV) {
// A current decl may not be available when emitting vtable thunks.
if (!CurCodeDecl)
return;
// If the return block isn't reachable, neither is this check, so don't emit
// it.
if (ReturnBlock.isValid() && ReturnBlock.getBlock()->use_empty())
return;
ReturnsNonNullAttr *RetNNAttr = nullptr;
if (SanOpts.has(SanitizerKind::ReturnsNonnullAttribute))
RetNNAttr = CurCodeDecl->getAttr<ReturnsNonNullAttr>();
if (!RetNNAttr && !requiresReturnValueNullabilityCheck())
return;
// Prefer the returns_nonnull attribute if it's present.
SourceLocation AttrLoc;
SanitizerMask CheckKind;
SanitizerHandler Handler;
if (RetNNAttr) {
assert(!requiresReturnValueNullabilityCheck() &&
"Cannot check nullability and the nonnull attribute");
AttrLoc = RetNNAttr->getLocation();
CheckKind = SanitizerKind::ReturnsNonnullAttribute;
Handler = SanitizerHandler::NonnullReturn;
} else {
if (auto *DD = dyn_cast<DeclaratorDecl>(CurCodeDecl))
if (auto *TSI = DD->getTypeSourceInfo())
if (auto FTL = TSI->getTypeLoc().getAsAdjusted<FunctionTypeLoc>())
AttrLoc = FTL.getReturnLoc().findNullabilityLoc();
CheckKind = SanitizerKind::NullabilityReturn;
Handler = SanitizerHandler::NullabilityReturn;
}
SanitizerScope SanScope(this);
// Make sure the "return" source location is valid. If we're checking a
// nullability annotation, make sure the preconditions for the check are met.
llvm::BasicBlock *Check = createBasicBlock("nullcheck");
llvm::BasicBlock *NoCheck = createBasicBlock("no.nullcheck");
llvm::Value *SLocPtr = Builder.CreateLoad(ReturnLocation, "return.sloc.load");
llvm::Value *CanNullCheck = Builder.CreateIsNotNull(SLocPtr);
if (requiresReturnValueNullabilityCheck())
CanNullCheck =
Builder.CreateAnd(CanNullCheck, RetValNullabilityPrecondition);
Builder.CreateCondBr(CanNullCheck, Check, NoCheck);
EmitBlock(Check);
// Now do the null check.
llvm::Value *Cond = Builder.CreateIsNotNull(RV);
llvm::Constant *StaticData[] = {EmitCheckSourceLocation(AttrLoc)};
llvm::Value *DynamicData[] = {SLocPtr};
EmitCheck(std::make_pair(Cond, CheckKind), Handler, StaticData, DynamicData);
EmitBlock(NoCheck);
#ifndef NDEBUG
// The return location should not be used after the check has been emitted.
ReturnLocation = Address::invalid();
#endif
}
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::Type *IRPtrTy = IRTy->getPointerTo();
llvm::Value *Placeholder = llvm::UndefValue::get(IRPtrTy->getPointerTo());
// FIXME: When we generate this IR in one pass, we shouldn't need
// this win32-specific alignment hack.
CharUnits Align = CharUnits::fromQuantity(4);
Placeholder = CGF.Builder.CreateAlignedLoad(IRPtrTy, Placeholder, Align);
return AggValueSlot::forAddr(Address(Placeholder, Align),
Ty.getQualifiers(),
AggValueSlot::IsNotDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
AggValueSlot::IsNotAliased,
AggValueSlot::DoesNotOverlap);
}
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.
Address local = GetAddrOfLocalVar(param);
QualType type = param->getType();
if (isInAllocaArgument(CGM.getCXXABI(), type)) {
CGM.ErrorUnsupported(param, "forwarded non-trivially copyable parameter");
}
// GetAddrOfLocalVar returns a pointer-to-pointer for references,
// but the argument needs to be the original pointer.
if (type->isReferenceType()) {
args.add(RValue::get(Builder.CreateLoad(local)), type);
// In ARC, move out of consumed arguments so that the release cleanup
// entered by StartFunction doesn't cause an over-release. This isn't
// optimal -O0 code generation, but it should get cleaned up when
// optimization is enabled. This also assumes that delegate calls are
// performed exactly once for a set of arguments, but that should be safe.
} else if (getLangOpts().ObjCAutoRefCount &&
param->hasAttr<NSConsumedAttr>() &&
type->isObjCRetainableType()) {
llvm::Value *ptr = Builder.CreateLoad(local);
auto null =
llvm::ConstantPointerNull::get(cast<llvm::PointerType>(ptr->getType()));
Builder.CreateStore(null, local);
args.add(RValue::get(ptr), type);
// For the most part, we just need to load the alloca, except that
// aggregate r-values are actually pointers to temporaries.
} else {
args.add(convertTempToRValue(local, type, loc), type);
}
// Deactivate the cleanup for the callee-destructed param that was pushed.
if (hasAggregateEvaluationKind(type) && !CurFuncIsThunk &&
type->castAs<RecordType>()->getDecl()->isParamDestroyedInCallee() &&
param->needsDestruction(getContext())) {
EHScopeStack::stable_iterator cleanup =
CalleeDestructedParamCleanups.lookup(cast<ParmVarDecl>(param));
assert(cleanup.isValid() &&
"cleanup for callee-destructed param not recorded");
// This unreachable is a temporary marker which will be removed later.
llvm::Instruction *isActive = Builder.CreateUnreachable();
args.addArgCleanupDeactivation(cleanup, isActive);
}
}
static bool isProvablyNull(llvm::Value *addr) {
return isa<llvm::ConstantPointerNull>(addr);
}
/// Emit the actual writing-back of a writeback.
static void emitWriteback(CodeGenFunction &CGF,
const CallArgList::Writeback &writeback) {
const LValue &srcLV = writeback.Source;
Address srcAddr = srcLV.getAddress(CGF);
assert(!isProvablyNull(srcAddr.getPointer()) &&
"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 = llvm::isKnownNonZero(srcAddr.getPointer(),
CGF.CGM.getDataLayout());
if (!provablyNonNull) {
llvm::BasicBlock *writebackBB = CGF.createBasicBlock("icr.writeback");
contBB = CGF.createBasicBlock("icr.done");
llvm::Value *isNull =
CGF.Builder.CreateIsNull(srcAddr.getPointer(), "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, srcAddr.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) {
ArrayRef<CallArgList::CallArgCleanup> Cleanups =
CallArgs.getCleanupsToDeactivate();
// Iterate in reverse to increase the likelihood of popping the cleanup.
for (const auto &I : llvm::reverse(Cleanups)) {
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 an __autoreleased temporary; it
/// might be copy-initialized with the current value of the given
/// address, but it will definitely be copied out of after the call.
static void emitWritebackArg(CodeGenFunction &CGF, CallArgList &args,
const ObjCIndirectCopyRestoreExpr *CRE) {
LValue srcLV;
// Make an optimistic effort to emit the address as an l-value.
// This can fail if the argument expression is more complicated.
if (const Expr *lvExpr = maybeGetUnaryAddrOfOperand(CRE->getSubExpr())) {
srcLV = CGF.EmitLValue(lvExpr);
// Otherwise, just emit it as a scalar.
} else {
Address srcAddr = CGF.EmitPointerWithAlignment(CRE->getSubExpr());
QualType srcAddrType =
CRE->getSubExpr()->getType()->castAs<PointerType>()->getPointeeType();
srcLV = CGF.MakeAddrLValue(srcAddr, srcAddrType);
}
Address srcAddr = srcLV.getAddress(CGF);
// 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.getPointer())) {
args.add(RValue::get(llvm::ConstantPointerNull::get(destType)),
CRE->getType());
return;
}
// Create the temporary.
Address temp = CGF.CreateTempAlloca(destType->getElementType(),
CGF.getPointerAlign(),
"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 = llvm::isKnownNonZero(srcAddr.getPointer(),
CGF.CGM.getDataLayout());
if (provablyNonNull) {
finalArgument = temp.getPointer();
} else {
llvm::Value *isNull =
CGF.Builder.CreateIsNull(srcAddr.getPointer(), "icr.isnull");
finalArgument = CGF.Builder.CreateSelect(isNull,
llvm::ConstantPointerNull::get(destType),
temp.getPointer(), "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);
// Save the stack.
llvm::Function *F = CGF.CGM.getIntrinsic(llvm::Intrinsic::stacksave);
StackBase = CGF.Builder.CreateCall(F, {}, "inalloca.save");
}
void CallArgList::freeArgumentMemory(CodeGenFunction &CGF) const {
if (StackBase) {
// Restore the stack after the call.
llvm::Function *F = CGF.CGM.getIntrinsic(llvm::Intrinsic::stackrestore);
CGF.Builder.CreateCall(F, StackBase);
}
}
void CodeGenFunction::EmitNonNullArgCheck(RValue RV, QualType ArgType,
SourceLocation ArgLoc,
AbstractCallee AC,
unsigned ParmNum) {
if (!AC.getDecl() || !(SanOpts.has(SanitizerKind::NonnullAttribute) ||
SanOpts.has(SanitizerKind::NullabilityArg)))
return;
// The param decl may be missing in a variadic function.
auto PVD = ParmNum < AC.getNumParams() ? AC.getParamDecl(ParmNum) : nullptr;
unsigned ArgNo = PVD ? PVD->getFunctionScopeIndex() : ParmNum;
// Prefer the nonnull attribute if it's present.
const NonNullAttr *NNAttr = nullptr;
if (SanOpts.has(SanitizerKind::NonnullAttribute))
NNAttr = getNonNullAttr(AC.getDecl(), PVD, ArgType, ArgNo);
bool CanCheckNullability = false;
if (SanOpts.has(SanitizerKind::NullabilityArg) && !NNAttr && PVD) {
auto Nullability = PVD->getType()->getNullability(getContext());
CanCheckNullability = Nullability &&
*Nullability == NullabilityKind::NonNull &&
PVD->getTypeSourceInfo();
}
if (!NNAttr && !CanCheckNullability)
return;
SourceLocation AttrLoc;
SanitizerMask CheckKind;
SanitizerHandler Handler;
if (NNAttr) {
AttrLoc = NNAttr->getLocation();
CheckKind = SanitizerKind::NonnullAttribute;
Handler = SanitizerHandler::NonnullArg;
} else {
AttrLoc = PVD->getTypeSourceInfo()->getTypeLoc().findNullabilityLoc();
CheckKind = SanitizerKind::NullabilityArg;
Handler = SanitizerHandler::NullabilityArg;
}
SanitizerScope SanScope(this);
llvm::Value *Cond = EmitNonNullRValueCheck(RV, ArgType);
llvm::Constant *StaticData[] = {
EmitCheckSourceLocation(ArgLoc), EmitCheckSourceLocation(AttrLoc),
llvm::ConstantInt::get(Int32Ty, ArgNo + 1),
};
EmitCheck(std::make_pair(Cond, CheckKind), Handler, StaticData, None);
}
// Check if the call is going to use the inalloca convention. This needs to
// agree with CGFunctionInfo::usesInAlloca. The CGFunctionInfo is arranged
// later, so we can't check it directly.
static bool hasInAllocaArgs(CodeGenModule &CGM, CallingConv ExplicitCC,
ArrayRef<QualType> ArgTypes) {
// The Swift calling convention doesn't go through the target-specific
// argument classification, so it never uses inalloca.
// TODO: Consider limiting inalloca use to only calling conventions supported
// by MSVC.
if (ExplicitCC == CC_Swift)
return false;
if (!CGM.getTarget().getCXXABI().isMicrosoft())
return false;
return llvm::any_of(ArgTypes, [&](QualType Ty) {
return isInAllocaArgument(CGM.getCXXABI(), Ty);
});
}
#ifndef NDEBUG
// Determine whether the given argument is an Objective-C method
// that may have type parameters in its signature.
static bool isObjCMethodWithTypeParams(const ObjCMethodDecl *method) {
const DeclContext *dc = method->getDeclContext();
if (const ObjCInterfaceDecl *classDecl = dyn_cast<ObjCInterfaceDecl>(dc)) {
return classDecl->getTypeParamListAsWritten();
}
if (const ObjCCategoryDecl *catDecl = dyn_cast<ObjCCategoryDecl>(dc)) {
return catDecl->getTypeParamList();
}
return false;
}
#endif
/// EmitCallArgs - Emit call arguments for a function.
void CodeGenFunction::EmitCallArgs(
CallArgList &Args, PrototypeWrapper Prototype,
llvm::iterator_range<CallExpr::const_arg_iterator> ArgRange,
AbstractCallee AC, unsigned ParamsToSkip, EvaluationOrder Order) {
SmallVector<QualType, 16> ArgTypes;
assert((ParamsToSkip == 0 || Prototype.P) &&
"Can't skip parameters if type info is not provided");
// This variable only captures *explicitly* written conventions, not those
// applied by default via command line flags or target defaults, such as
// thiscall, aapcs, stdcall via -mrtd, etc. Computing that correctly would
// require knowing if this is a C++ instance method or being able to see
// unprototyped FunctionTypes.
CallingConv ExplicitCC = CC_C;
// First, if a prototype was provided, use those argument types.
bool IsVariadic = false;
if (Prototype.P) {
const auto *MD = Prototype.P.dyn_cast<const ObjCMethodDecl *>();
if (MD) {
IsVariadic = MD->isVariadic();
ExplicitCC = getCallingConventionForDecl(
MD, CGM.getTarget().getTriple().isOSWindows());
ArgTypes.assign(MD->param_type_begin() + ParamsToSkip,
MD->param_type_end());
} else {
const auto *FPT = Prototype.P.get<const FunctionProtoType *>();
IsVariadic = FPT->isVariadic();
ExplicitCC = FPT->getExtInfo().getCC();
ArgTypes.assign(FPT->param_type_begin() + ParamsToSkip,
FPT->param_type_end());
}
#ifndef NDEBUG
// Check that the prototyped types match the argument expression types.
bool isGenericMethod = MD && isObjCMethodWithTypeParams(MD);
CallExpr::const_arg_iterator Arg = ArgRange.begin();
for (QualType Ty : ArgTypes) {
assert(Arg != ArgRange.end() && "Running over edge of argument list!");
assert(
(isGenericMethod || Ty->isVariablyModifiedType() ||
Ty.getNonReferenceType()->isObjCRetainableType() ||
getContext()
.getCanonicalType(Ty.getNonReferenceType())
.getTypePtr() ==
getContext().getCanonicalType((*Arg)->getType()).getTypePtr()) &&
"type mismatch in call argument!");
++Arg;
}
// Either we've emitted all the call args, or we have a call to variadic
// function.
assert((Arg == ArgRange.end() || IsVariadic) &&
"Extra arguments in non-variadic function!");
#endif
}
// If we still have any arguments, emit them using the type of the argument.
for (auto *A : llvm::make_range(std::next(ArgRange.begin(), ArgTypes.size()),
ArgRange.end()))
ArgTypes.push_back(IsVariadic ? getVarArgType(A) : A->getType());
assert((int)ArgTypes.size() == (ArgRange.end() - ArgRange.begin()));
// We must evaluate arguments from right to left in the MS C++ ABI,
// because arguments are destroyed left to right in the callee. As a special
// case, there are certain language constructs that require left-to-right
// evaluation, and in those cases we consider the evaluation order requirement
// to trump the "destruction order is reverse construction order" guarantee.
bool LeftToRight =
CGM.getTarget().getCXXABI().areArgsDestroyedLeftToRightInCallee()
? Order == EvaluationOrder::ForceLeftToRight
: Order != EvaluationOrder::ForceRightToLeft;
auto MaybeEmitImplicitObjectSize = [&](unsigned I, const Expr *Arg,
RValue EmittedArg) {
if (!AC.hasFunctionDecl() || I >= AC.getNumParams())
return;
auto *PS = AC.getParamDecl(I)->getAttr<PassObjectSizeAttr>();
if (PS == nullptr)
return;
const auto &Context = getContext();
auto SizeTy = Context.getSizeType();
auto T = Builder.getIntNTy(Context.getTypeSize(SizeTy));
assert(EmittedArg.getScalarVal() && "We emitted nothing for the arg?");
llvm::Value *V = evaluateOrEmitBuiltinObjectSize(Arg, PS->getType(), T,
EmittedArg.getScalarVal(),
PS->isDynamic());
Args.add(RValue::get(V), SizeTy);
// If we're emitting args in reverse, be sure to do so with
// pass_object_size, as well.
if (!LeftToRight)
std::swap(Args.back(), *(&Args.back() - 1));
};
// Insert a stack save if we're going to need any inalloca args.
if (hasInAllocaArgs(CGM, ExplicitCC, ArgTypes)) {
assert(getTarget().getTriple().getArch() == llvm::Triple::x86 &&
"inalloca only supported on x86");
Args.allocateArgumentMemory(*this);
}
// Evaluate each argument in the appropriate order.
size_t CallArgsStart = Args.size();
for (unsigned I = 0, E = ArgTypes.size(); I != E; ++I) {
unsigned Idx = LeftToRight ? I : E - I - 1;
CallExpr::const_arg_iterator Arg = ArgRange.begin() + Idx;
unsigned InitialArgSize = Args.size();
// If *Arg is an ObjCIndirectCopyRestoreExpr, check that either the types of
// the argument and parameter match or the objc method is parameterized.
assert((!isa<ObjCIndirectCopyRestoreExpr>(*Arg) ||
getContext().hasSameUnqualifiedType((*Arg)->getType(),
ArgTypes[Idx]) ||
(isa<ObjCMethodDecl>(AC.getDecl()) &&
isObjCMethodWithTypeParams(cast<ObjCMethodDecl>(AC.getDecl())))) &&
"Argument and parameter types don't match");
EmitCallArg(Args, *Arg, ArgTypes[Idx]);
// In particular, we depend on it being the last arg in Args, and the
// objectsize bits depend on there only being one arg if !LeftToRight.
assert(InitialArgSize + 1 == Args.size() &&
"The code below depends on only adding one arg per EmitCallArg");
(void)InitialArgSize;
// Since pointer argument are never emitted as LValue, it is safe to emit
// non-null argument check for r-value only.
if (!Args.back().hasLValue()) {
RValue RVArg = Args.back().getKnownRValue();
EmitNonNullArgCheck(RVArg, ArgTypes[Idx], (*Arg)->getExprLoc(), AC,
ParamsToSkip + Idx);
// @llvm.objectsize should never have side-effects and shouldn't need
// destruction/cleanups, so we can safely "emit" it after its arg,
// regardless of right-to-leftness
MaybeEmitImplicitObjectSize(Idx, *Arg, RVArg);
}
}
if (!LeftToRight) {
// Un-reverse the arguments we just evaluated so they match up with the LLVM
// IR function.
std::reverse(Args.begin() + CallArgsStart, Args.end());
}
}
namespace {
struct DestroyUnpassedArg final : EHScopeStack::Cleanup {
DestroyUnpassedArg(Address Addr, QualType Ty)
: Addr(Addr), Ty(Ty) {}
Address Addr;
QualType Ty;
void Emit(CodeGenFunction &CGF, Flags flags) override {
QualType::DestructionKind DtorKind = Ty.isDestructedType();
if (DtorKind == QualType::DK_cxx_destructor) {
const CXXDestructorDecl *Dtor = Ty->getAsCXXRecordDecl()->getDestructor();
assert(!Dtor->isTrivial());
CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete, /*for vbase*/ false,
/*Delegating=*/false, Addr, Ty);
} else {
CGF.callCStructDestructor(CGF.MakeAddrLValue(Addr, Ty));
}
}
};
struct DisableDebugLocationUpdates {
CodeGenFunction &CGF;
bool disabledDebugInfo;
DisableDebugLocationUpdates(CodeGenFunction &CGF, const Expr *E) : CGF(CGF) {
if ((disabledDebugInfo = isa<CXXDefaultArgExpr>(E) && CGF.getDebugInfo()))
CGF.disableDebugInfo();
}
~DisableDebugLocationUpdates() {
if (disabledDebugInfo)
CGF.enableDebugInfo();
}
};
} // end anonymous namespace
RValue CallArg::getRValue(CodeGenFunction &CGF) const {
if (!HasLV)
return RV;
LValue Copy = CGF.MakeAddrLValue(CGF.CreateMemTemp(Ty), Ty);
CGF.EmitAggregateCopy(Copy, LV, Ty, AggValueSlot::DoesNotOverlap,
LV.isVolatile());
IsUsed = true;
return RValue::getAggregate(Copy.getAddress(CGF));
}
void CallArg::copyInto(CodeGenFunction &CGF, Address Addr) const {
LValue Dst = CGF.MakeAddrLValue(Addr, Ty);
if (!HasLV && RV.isScalar())
CGF.EmitStoreOfScalar(RV.getScalarVal(), Dst, /*isInit=*/true);
else if (!HasLV && RV.isComplex())
CGF.EmitStoreOfComplex(RV.getComplexVal(), Dst, /*init=*/true);
else {
auto Addr = HasLV ? LV.getAddress(CGF) : RV.getAggregateAddress();
LValue SrcLV = CGF.MakeAddrLValue(Addr, Ty);
// We assume that call args are never copied into subobjects.
CGF.EmitAggregateCopy(Dst, SrcLV, Ty, AggValueSlot::DoesNotOverlap,
HasLV ? LV.isVolatileQualified()
: RV.isVolatileQualified());
}
IsUsed = true;
}
void CodeGenFunction::EmitCallArg(CallArgList &args, const Expr *E,
QualType type) {
DisableDebugLocationUpdates Dis(*this, E);
if (const ObjCIndirectCopyRestoreExpr *CRE
= dyn_cast<ObjCIndirectCopyRestoreExpr>(E)) {
assert(getLangOpts().ObjCAutoRefCount);
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 &&
type->castAs<RecordType>()->getDecl()->isParamDestroyedInCallee()) {
// 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");
bool DestroyedInCallee = true, NeedsEHCleanup = true;
if (const auto *RD = type->getAsCXXRecordDecl())
DestroyedInCallee = RD->hasNonTrivialDestructor();
else
NeedsEHCleanup = needsEHCleanup(type.isDestructedType());
if (DestroyedInCallee)
Slot.setExternallyDestructed();
EmitAggExpr(E, Slot);
RValue RV = Slot.asRValue();
args.add(RV, type);
if (DestroyedInCallee && NeedsEHCleanup) {
// 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.getAddress(),
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());
args.addUncopiedAggregate(L, 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::FunctionCallee callee,
const llvm::Twine &name) {
return EmitNounwindRuntimeCall(callee, None, name);
}
/// Emits a call to the given nounwind runtime function.
llvm::CallInst *
CodeGenFunction::EmitNounwindRuntimeCall(llvm::FunctionCallee 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::FunctionCallee callee,
const llvm::Twine &name) {
return EmitRuntimeCall(callee, None, name);
}
// Calls which may throw must have operand bundles indicating which funclet
// they are nested within.
SmallVector<llvm::OperandBundleDef, 1>
CodeGenFunction::getBundlesForFunclet(llvm::Value *Callee) {
SmallVector<llvm::OperandBundleDef, 1> BundleList;
// There is no need for a funclet operand bundle if we aren't inside a
// funclet.
if (!CurrentFuncletPad)
return BundleList;
// Skip intrinsics which cannot throw.
auto *CalleeFn = dyn_cast<llvm::Function>(Callee->stripPointerCasts());
if (CalleeFn && CalleeFn->isIntrinsic() && CalleeFn->doesNotThrow())
return BundleList;
BundleList.emplace_back("funclet", CurrentFuncletPad);
return BundleList;
}
/// Emits a simple call (never an invoke) to the given runtime function.
llvm::CallInst *CodeGenFunction::EmitRuntimeCall(llvm::FunctionCallee callee,
ArrayRef<llvm::Value *> args,
const llvm::Twine &name) {
llvm::CallInst *call = Builder.CreateCall(
callee, args, getBundlesForFunclet(callee.getCallee()), name);
call->setCallingConv(getRuntimeCC());
return call;
}
/// Emits a call or invoke to the given noreturn runtime function.
void CodeGenFunction::EmitNoreturnRuntimeCallOrInvoke(
llvm::FunctionCallee callee, ArrayRef<llvm::Value *> args) {
SmallVector<llvm::OperandBundleDef, 1> BundleList =
getBundlesForFunclet(callee.getCallee());
if (getInvokeDest()) {
llvm::InvokeInst *invoke =
Builder.CreateInvoke(callee,
getUnreachableBlock(),
getInvokeDest(),
args,
BundleList);
invoke->setDoesNotReturn();
invoke->setCallingConv(getRuntimeCC());
} else {
llvm::CallInst *call = Builder.CreateCall(callee, args, BundleList);
call->setDoesNotReturn();
call->setCallingConv(getRuntimeCC());
Builder.CreateUnreachable();
}
}
/// Emits a call or invoke instruction to the given nullary runtime function.
llvm::CallBase *
CodeGenFunction::EmitRuntimeCallOrInvoke(llvm::FunctionCallee callee,
const Twine &name) {
return EmitRuntimeCallOrInvoke(callee, None, name);
}
/// Emits a call or invoke instruction to the given runtime function.
llvm::CallBase *
CodeGenFunction::EmitRuntimeCallOrInvoke(llvm::FunctionCallee callee,
ArrayRef<llvm::Value *> args,
const Twine &name) {
llvm::CallBase *call = EmitCallOrInvoke(callee, args, name);
call->setCallingConv(getRuntimeCC());
return call;
}
/// Emits a call or invoke instruction to the given function, depending
/// on the current state of the EH stack.
llvm::CallBase *CodeGenFunction::EmitCallOrInvoke(llvm::FunctionCallee Callee,
ArrayRef<llvm::Value *> Args,
const Twine &Name) {
llvm::BasicBlock *InvokeDest = getInvokeDest();
SmallVector<llvm::OperandBundleDef, 1> BundleList =
getBundlesForFunclet(Callee.getCallee());
llvm::CallBase *Inst;
if (!InvokeDest)
Inst = Builder.CreateCall(Callee, Args, BundleList, Name);
else {
llvm::BasicBlock *ContBB = createBasicBlock("invoke.cont");
Inst = Builder.CreateInvoke(Callee, ContBB, InvokeDest, Args, BundleList,
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;
}
void CodeGenFunction::deferPlaceholderReplacement(llvm::Instruction *Old,
llvm::Value *New) {
DeferredReplacements.push_back(std::make_pair(Old, New));
}
namespace {
/// Specify given \p NewAlign as the alignment of return value attribute. If
/// such attribute already exists, re-set it to the maximal one of two options.
LLVM_NODISCARD llvm::AttributeList
maybeRaiseRetAlignmentAttribute(llvm::LLVMContext &Ctx,
const llvm::AttributeList &Attrs,
llvm::Align NewAlign) {
llvm::Align CurAlign = Attrs.getRetAlignment().valueOrOne();
if (CurAlign >= NewAlign)
return Attrs;
llvm::Attribute AlignAttr = llvm::Attribute::getWithAlignment(Ctx, NewAlign);
return Attrs
.removeAttribute(Ctx, llvm::AttributeList::ReturnIndex,
llvm::Attribute::AttrKind::Alignment)
.addAttribute(Ctx, llvm::AttributeList::ReturnIndex, AlignAttr);
}
template <typename AlignedAttrTy> class AbstractAssumeAlignedAttrEmitter {
protected:
CodeGenFunction &CGF;
/// We do nothing if this is, or becomes, nullptr.
const AlignedAttrTy *AA = nullptr;
llvm::Value *Alignment = nullptr; // May or may not be a constant.
llvm::ConstantInt *OffsetCI = nullptr; // Constant, hopefully zero.
AbstractAssumeAlignedAttrEmitter(CodeGenFunction &CGF_, const Decl *FuncDecl)
: CGF(CGF_) {
if (!FuncDecl)
return;
AA = FuncDecl->getAttr<AlignedAttrTy>();
}
public:
/// If we can, materialize the alignment as an attribute on return value.
LLVM_NODISCARD llvm::AttributeList
TryEmitAsCallSiteAttribute(const llvm::AttributeList &Attrs) {
if (!AA || OffsetCI || CGF.SanOpts.has(SanitizerKind::Alignment))
return Attrs;
const auto *AlignmentCI = dyn_cast<llvm::ConstantInt>(Alignment);
if (!AlignmentCI)
return Attrs;
// We may legitimately have non-power-of-2 alignment here.
// If so, this is UB land, emit it via `@llvm.assume` instead.
if (!AlignmentCI->getValue().isPowerOf2())
return Attrs;
llvm::AttributeList NewAttrs = maybeRaiseRetAlignmentAttribute(
CGF.getLLVMContext(), Attrs,
llvm::Align(
AlignmentCI->getLimitedValue(llvm::Value::MaximumAlignment)));
AA = nullptr; // We're done. Disallow doing anything else.
return NewAttrs;
}
/// Emit alignment assumption.
/// This is a general fallback that we take if either there is an offset,
/// or the alignment is variable or we are sanitizing for alignment.
void EmitAsAnAssumption(SourceLocation Loc, QualType RetTy, RValue &Ret) {
if (!AA)
return;
CGF.emitAlignmentAssumption(Ret.getScalarVal(), RetTy, Loc,
AA->getLocation(), Alignment, OffsetCI);
AA = nullptr; // We're done. Disallow doing anything else.
}
};
/// Helper data structure to emit `AssumeAlignedAttr`.
class AssumeAlignedAttrEmitter final
: public AbstractAssumeAlignedAttrEmitter<AssumeAlignedAttr> {
public:
AssumeAlignedAttrEmitter(CodeGenFunction &CGF_, const Decl *FuncDecl)
: AbstractAssumeAlignedAttrEmitter(CGF_, FuncDecl) {
if (!AA)
return;
// It is guaranteed that the alignment/offset are constants.
Alignment = cast<llvm::ConstantInt>(CGF.EmitScalarExpr(AA->getAlignment()));
if (Expr *Offset = AA->getOffset()) {
OffsetCI = cast<llvm::ConstantInt>(CGF.EmitScalarExpr(Offset));
if (OffsetCI->isNullValue()) // Canonicalize zero offset to no offset.
OffsetCI = nullptr;
}
}
};
/// Helper data structure to emit `AllocAlignAttr`.
class AllocAlignAttrEmitter final
: public AbstractAssumeAlignedAttrEmitter<AllocAlignAttr> {
public:
AllocAlignAttrEmitter(CodeGenFunction &CGF_, const Decl *FuncDecl,
const CallArgList &CallArgs)
: AbstractAssumeAlignedAttrEmitter(CGF_, FuncDecl) {
if (!AA)
return;
// Alignment may or may not be a constant, and that is okay.
Alignment = CallArgs[AA->getParamIndex().getLLVMIndex()]
.getRValue(CGF)
.getScalarVal();
}
};
} // namespace
RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
const CGCallee &Callee,
ReturnValueSlot ReturnValue,
const CallArgList &CallArgs,
llvm::CallBase **callOrInvoke,
SourceLocation Loc) {
// FIXME: We no longer need the types from CallArgs; lift up and simplify.
assert(Callee.isOrdinary() || Callee.isVirtual());
// 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 = getTypes().GetFunctionType(CallInfo);
const Decl *TargetDecl = Callee.getAbstractInfo().getCalleeDecl().getDecl();
if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl)) {
// We can only guarantee that a function is called from the correct
// context/function based on the appropriate target attributes,
// so only check in the case where we have both always_inline and target
// since otherwise we could be making a conditional call after a check for
// the proper cpu features (and it won't cause code generation issues due to
// function based code generation).
if (TargetDecl->hasAttr<AlwaysInlineAttr>() &&
TargetDecl->hasAttr<TargetAttr>())
checkTargetFeatures(Loc, FD);
// Some architectures (such as x86-64) have the ABI changed based on
// attribute-target/features. Give them a chance to diagnose.
CGM.getTargetCodeGenInfo().checkFunctionCallABI(
CGM, Loc, dyn_cast_or_null<FunctionDecl>(CurCodeDecl), FD, CallArgs);
}
#ifndef NDEBUG
if (!(CallInfo.isVariadic() && CallInfo.getArgStruct())) {
// For an inalloca varargs function, we don't expect CallInfo to match the
// function pointer's type, because the inalloca struct a will have extra
// fields in it for the varargs parameters. Code later in this function
// bitcasts the function pointer to the type derived from CallInfo.
//
// In other cases, we assert that the types match up (until pointers stop
// having pointee types).
llvm::Type *TypeFromVal;
if (Callee.isVirtual())
TypeFromVal = Callee.getVirtualFunctionType();
else
TypeFromVal =
Callee.getFunctionPointer()->getType()->getPointerElementType();
assert(IRFuncTy == TypeFromVal);
}
#endif
// 1. Set up the arguments.
// If we're using inalloca, insert the allocation after the stack save.
// FIXME: Do this earlier rather than hacking it in here!
Address ArgMemory = Address::invalid();
if (llvm::StructType *ArgStruct = CallInfo.getArgStruct()) {
const llvm::DataLayout &DL = CGM.getDataLayout();
llvm::Instruction *IP = CallArgs.getStackBase();
llvm::AllocaInst *AI;
if (IP) {
IP = IP->getNextNode();
AI = new llvm::AllocaInst(ArgStruct, DL.getAllocaAddrSpace(),
"argmem", IP);
} else {
AI = CreateTempAlloca(ArgStruct, "argmem");
}
auto Align = CallInfo.getArgStructAlignment();
AI->setAlignment(Align.getAsAlign());
AI->setUsedWithInAlloca(true);
assert(AI->isUsedWithInAlloca() && !AI->isStaticAlloca());
ArgMemory = Address(AI, Align);
}
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.
Address SRetPtr = Address::invalid();
Address SRetAlloca = Address::invalid();
llvm::Value *UnusedReturnSizePtr = nullptr;
if (RetAI.isIndirect() || RetAI.isInAlloca() || RetAI.isCoerceAndExpand()) {
if (!ReturnValue.isNull()) {
SRetPtr = ReturnValue.getValue();
} else {
SRetPtr = CreateMemTemp(RetTy, "tmp", &SRetAlloca);
if (HaveInsertPoint() && ReturnValue.isUnused()) {
uint64_t size =
CGM.getDataLayout().getTypeAllocSize(ConvertTypeForMem(RetTy));
UnusedReturnSizePtr = EmitLifetimeStart(size, SRetAlloca.getPointer());
}
}
if (IRFunctionArgs.hasSRetArg()) {
IRCallArgs[IRFunctionArgs.getSRetArgNo()] = SRetPtr.getPointer();
} else if (RetAI.isInAlloca()) {
Address Addr =
Builder.CreateStructGEP(ArgMemory, RetAI.getInAllocaFieldIndex());
Builder.CreateStore(SRetPtr.getPointer(), Addr);
}
}
Address swiftErrorTemp = Address::invalid();
Address swiftErrorArg = Address::invalid();
// When passing arguments using temporary allocas, we need to add the
// appropriate lifetime markers. This vector keeps track of all the lifetime
// markers that need to be ended right after the call.
SmallVector<CallLifetimeEnd, 2> CallLifetimeEndAfterCall;
// Translate all of the arguments as necessary to match the IR lowering.
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;
// 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 (I->isAggregate()) {
Address Addr = I->hasLValue()
? I->getKnownLValue().getAddress(*this)
: I->getKnownRValue().getAggregateAddress();
llvm::Instruction *Placeholder =
cast<llvm::Instruction>(Addr.getPointer());
if (!ArgInfo.getInAllocaIndirect()) {
// Replace the placeholder with the appropriate argument slot GEP.
CGBuilderTy::InsertPoint IP = Builder.saveIP();
Builder.SetInsertPoint(Placeholder);
Addr = Builder.CreateStructGEP(ArgMemory,
ArgInfo.getInAllocaFieldIndex());
Builder.restoreIP(IP);
} else {
// For indirect things such as overaligned structs, replace the
// placeholder with a regular aggregate temporary alloca. Store the
// address of this alloca into the struct.
Addr = CreateMemTemp(info_it->type, "inalloca.indirect.tmp");
Address ArgSlot = Builder.CreateStructGEP(
ArgMemory, ArgInfo.getInAllocaFieldIndex());
Builder.CreateStore(Addr.getPointer(), ArgSlot);
}
deferPlaceholderReplacement(Placeholder, Addr.getPointer());
} else if (ArgInfo.getInAllocaIndirect()) {
// Make a temporary alloca and store the address of it into the argument
// struct.
Address Addr = CreateMemTempWithoutCast(
I->Ty, getContext().getTypeAlignInChars(I->Ty),
"indirect-arg-temp");
I->copyInto(*this, Addr);
Address ArgSlot =
Builder.CreateStructGEP(ArgMemory, ArgInfo.getInAllocaFieldIndex());
Builder.CreateStore(Addr.getPointer(), ArgSlot);
} else {
// Store the RValue into the argument struct.
Address 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);
I->copyInto(*this, Addr);
}
break;
}
case ABIArgInfo::Indirect:
case ABIArgInfo::IndirectAliased: {
assert(NumIRArgs == 1);
if (!I->isAggregate()) {
// Make a temporary alloca to pass the argument.
Address Addr = CreateMemTempWithoutCast(
I->Ty, ArgInfo.getIndirectAlign(), "indirect-arg-temp");
IRCallArgs[FirstIRArg] = Addr.getPointer();
I->copyInto(*this, Addr);
} 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 not located in default
// or alloca address space.
Address Addr = I->hasLValue()
? I->getKnownLValue().getAddress(*this)
: I->getKnownRValue().getAggregateAddress();
llvm::Value *V = Addr.getPointer();
CharUnits Align = ArgInfo.getIndirectAlign();
const llvm::DataLayout *TD = &CGM.getDataLayout();
assert((FirstIRArg >= IRFuncTy->getNumParams() ||
IRFuncTy->getParamType(FirstIRArg)->getPointerAddressSpace() ==
TD->getAllocaAddrSpace()) &&
"indirect argument must be in alloca address space");
bool NeedCopy = false;
if (Addr.getAlignment() < Align &&
llvm::getOrEnforceKnownAlignment(V, Align.getAsAlign(), *TD) <
Align.getAsAlign()) {
NeedCopy = true;
} else if (I->hasLValue()) {
auto LV = I->getKnownLValue();
auto AS = LV.getAddressSpace();
if (!ArgInfo.getIndirectByVal() ||
(LV.getAlignment() < getContext().getTypeAlignInChars(I->Ty))) {
NeedCopy = true;
}
if (!getLangOpts().OpenCL) {
if ((ArgInfo.getIndirectByVal() &&
(AS != LangAS::Default &&
AS != CGM.getASTAllocaAddressSpace()))) {
NeedCopy = true;
}
}
// For OpenCL even if RV is located in default or alloca address space
// we don't want to perform address space cast for it.
else if ((ArgInfo.getIndirectByVal() &&
Addr.getType()->getAddressSpace() != IRFuncTy->
getParamType(FirstIRArg)->getPointerAddressSpace())) {
NeedCopy = true;
}
}
if (NeedCopy) {
// Create an aligned temporary, and copy to it.
Address AI = CreateMemTempWithoutCast(
I->Ty, ArgInfo.getIndirectAlign(), "byval-temp");
IRCallArgs[FirstIRArg] = AI.getPointer();
// Emit lifetime markers for the temporary alloca.
uint64_t ByvalTempElementSize =
CGM.getDataLayout().getTypeAllocSize(AI.getElementType());
llvm::Value *LifetimeSize =
EmitLifetimeStart(ByvalTempElementSize, AI.getPointer());
// Add cleanup code to emit the end lifetime marker after the call.
if (LifetimeSize) // In case we disabled lifetime markers.
CallLifetimeEndAfterCall.emplace_back(AI, LifetimeSize);
// Generate the copy.
I->copyInto(*this, AI);
} else {
// Skip the extra memcpy call.
auto *T = V->getType()->getPointerElementType()->getPointerTo(
CGM.getDataLayout().getAllocaAddrSpace());
IRCallArgs[FirstIRArg] = getTargetHooks().performAddrSpaceCast(
*this, V, LangAS::Default, CGM.getASTAllocaAddressSpace(), T,
true);
}
}
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 (!I->isAggregate())
V = I->getKnownRValue().getScalarVal();
else
V = Builder.CreateLoad(
I->hasLValue() ? I->getKnownLValue().getAddress(*this)
: I->getKnownRValue().getAggregateAddress());
// Implement swifterror by copying into a new swifterror argument.
// We'll write back in the normal path out of the call.
if (CallInfo.getExtParameterInfo(ArgNo).getABI()
== ParameterABI::SwiftErrorResult) {
assert(!swiftErrorTemp.isValid() && "multiple swifterror args");
QualType pointeeTy = I->Ty->getPointeeType();
swiftErrorArg =
Address(V, getContext().getTypeAlignInChars(pointeeTy));
swiftErrorTemp =
CreateMemTemp(pointeeTy, getPointerAlign(), "swifterror.temp");
V = swiftErrorTemp.getPointer();
cast<llvm::AllocaInst>(V)->setSwiftError(true);
llvm::Value *errorValue = Builder.CreateLoad(swiftErrorArg);
Builder.CreateStore(errorValue, swiftErrorTemp);
}
// 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.
Address Src = Address::invalid();
if (!I->isAggregate()) {
Src = CreateMemTemp(I->Ty, "coerce");
I->copyInto(*this, Src);
} else {
Src = I->hasLValue() ? I->getKnownLValue().getAddress(*this)
: I->getKnownRValue().getAggregateAddress();
}
// If the value is offset in memory, apply the offset now.
Src = emitAddressAtOffset(*this, Src, ArgInfo);
// 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 = Src.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) {
Address TempAlloca
= CreateTempAlloca(STy, Src.getAlignment(),
Src.getName() + ".coerce");
Builder.CreateMemCpy(TempAlloca, Src, SrcSize);
Src = TempAlloca;
} else {
Src = Builder.CreateBitCast(Src,
STy->getPointerTo(Src.getAddressSpace()));
}
assert(NumIRArgs == STy->getNumElements());
for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
Address EltPtr = Builder.CreateStructGEP(Src, i);
llvm::Value *LI = Builder.CreateLoad(EltPtr);
IRCallArgs[FirstIRArg + i] = LI;
}
} else {
// In the simple case, just pass the coerced loaded value.
assert(NumIRArgs == 1);
llvm::Value *Load =
CreateCoercedLoad(Src, ArgInfo.getCoerceToType(), *this);
if (CallInfo.isCmseNSCall()) {
// For certain parameter types, clear padding bits, as they may reveal
// sensitive information.
// Small struct/union types are passed as integer arrays.
auto *ATy = dyn_cast<llvm::ArrayType>(Load->getType());
if (ATy != nullptr && isa<RecordType>(I->Ty.getCanonicalType()))
Load = EmitCMSEClearRecord(Load, ATy, I->Ty);
}
IRCallArgs[FirstIRArg] = Load;
}
break;
}
case ABIArgInfo::CoerceAndExpand: {
auto coercionType = ArgInfo.getCoerceAndExpandType();
auto layout = CGM.getDataLayout().getStructLayout(coercionType);
llvm::Value *tempSize = nullptr;
Address addr = Address::invalid();
Address AllocaAddr = Address::invalid();
if (I->isAggregate()) {
addr = I->hasLValue() ? I->getKnownLValue().getAddress(*this)
: I->getKnownRValue().getAggregateAddress();
} else {
RValue RV = I->getKnownRValue();
assert(RV.isScalar()); // complex should always just be direct
llvm::Type *scalarType = RV.getScalarVal()->getType();
auto scalarSize = CGM.getDataLayout().getTypeAllocSize(scalarType);
auto scalarAlign = CGM.getDataLayout().getPrefTypeAlignment(scalarType);
// Materialize to a temporary.
addr = CreateTempAlloca(
RV.getScalarVal()->getType(),
CharUnits::fromQuantity(std::max(
(unsigned)layout->getAlignment().value(), scalarAlign)),
"tmp",
/*ArraySize=*/nullptr, &AllocaAddr);
tempSize = EmitLifetimeStart(scalarSize, AllocaAddr.getPointer());
Builder.CreateStore(RV.getScalarVal(), addr);
}
addr = Builder.CreateElementBitCast(addr, coercionType);
unsigned IRArgPos = FirstIRArg;
for (unsigned i = 0, e = coercionType->getNumElements(); i != e; ++i) {
llvm::Type *eltType = coercionType->getElementType(i);
if (ABIArgInfo::isPaddingForCoerceAndExpand(eltType)) continue;
Address eltAddr = Builder.CreateStructGEP(addr, i);
llvm::Value *elt = Builder.CreateLoad(eltAddr);
IRCallArgs[IRArgPos++] = elt;
}
assert(IRArgPos == FirstIRArg + NumIRArgs);
if (tempSize) {
EmitLifetimeEnd(tempSize, AllocaAddr.getPointer());
}
break;
}
case ABIArgInfo::Expand: {
unsigned IRArgPos = FirstIRArg;
ExpandTypeToArgs(I->Ty, *I, IRFuncTy, IRCallArgs, IRArgPos);
assert(IRArgPos == FirstIRArg + NumIRArgs);
break;
}
}
}
const CGCallee &ConcreteCallee = Callee.prepareConcreteCallee(*this);
llvm::Value *CalleePtr = ConcreteCallee.getFunctionPointer();
// If we're using inalloca, set up that argument.
if (ArgMemory.isValid()) {
llvm::Value *Arg = ArgMemory.getPointer();
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 = CalleePtr->getType()->getPointerAddressSpace();
CalleePtr =
Builder.CreateBitCast(CalleePtr, IRFuncTy->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;
}
// 2. Prepare the function pointer.
// If the callee is a bitcast of a non-variadic function to have a
// variadic function pointer type, check to see if we can remove the
// bitcast. This comes up with unprototyped functions.
//
// This makes the IR nicer, but more importantly it ensures that we
// can inline the function at -O0 if it is marked always_inline.
auto simplifyVariadicCallee = [](llvm::FunctionType *CalleeFT,
llvm::Value *Ptr) -> llvm::Function * {
if (!CalleeFT->isVarArg())
return nullptr;
// Get underlying value if it's a bitcast
if (llvm::ConstantExpr *CE = dyn_cast<llvm::ConstantExpr>(Ptr)) {
if (CE->getOpcode() == llvm::Instruction::BitCast)
Ptr = CE->getOperand(0);
}
llvm::Function *OrigFn = dyn_cast<llvm::Function>(Ptr);
if (!OrigFn)
return nullptr;
llvm::FunctionType *OrigFT = OrigFn->getFunctionType();
// If the original type is variadic, or if any of the component types
// disagree, we cannot remove the cast.
if (OrigFT->isVarArg() ||
OrigFT->getNumParams() != CalleeFT->getNumParams() ||
OrigFT->getReturnType() != CalleeFT->getReturnType())
return nullptr;
for (unsigned i = 0, e = OrigFT->getNumParams(); i != e; ++i)
if (OrigFT->getParamType(i) != CalleeFT->getParamType(i))
return nullptr;
return OrigFn;
};
if (llvm::Function *OrigFn = simplifyVariadicCallee(IRFuncTy, CalleePtr)) {
CalleePtr = OrigFn;
IRFuncTy = OrigFn->getFunctionType();
}
// 3. Perform the actual call.
// Deactivate any cleanups that we're supposed to do immediately before
// the call.
if (!CallArgs.getCleanupsToDeactivate().empty())
deactivateArgCleanupsBeforeCall(*this, CallArgs);
// Assert that the arguments we computed match up. The IR verifier
// will catch this, but this is a common enough source of problems
// during IRGen changes that it's way better for debugging to catch
// it ourselves here.
#ifndef NDEBUG
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));
}
#endif
// Update the largest vector width if any arguments have vector types.
for (unsigned i = 0; i < IRCallArgs.size(); ++i) {
if (auto *VT = dyn_cast<llvm::VectorType>(IRCallArgs[i]->getType()))
LargestVectorWidth =
std::max((uint64_t)LargestVectorWidth,
VT->getPrimitiveSizeInBits().getKnownMinSize());
}
// Compute the calling convention and attributes.
unsigned CallingConv;
llvm::AttributeList Attrs;
CGM.ConstructAttributeList(CalleePtr->getName(), CallInfo,
Callee.getAbstractInfo(), Attrs, CallingConv,
/*AttrOnCallSite=*/true);
if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(CurFuncDecl))
if (FD->hasAttr<StrictFPAttr>())
// All calls within a strictfp function are marked strictfp
Attrs =
Attrs.addAttribute(getLLVMContext(), llvm::AttributeList::FunctionIndex,
llvm::Attribute::StrictFP);
// Add call-site nomerge attribute if exists.
if (InNoMergeAttributedStmt)
Attrs =
Attrs.addAttribute(getLLVMContext(), llvm::AttributeList::FunctionIndex,
llvm::Attribute::NoMerge);
// Apply some call-site-specific attributes.
// TODO: work this into building the attribute set.
// Apply always_inline to all calls within flatten functions.
// FIXME: should this really take priority over __try, below?
if (CurCodeDecl && CurCodeDecl->hasAttr<FlattenAttr>() &&
!(TargetDecl && TargetDecl->hasAttr<NoInlineAttr>())) {
Attrs =
Attrs.addAttribute(getLLVMContext(), llvm::AttributeList::FunctionIndex,
llvm::Attribute::AlwaysInline);
}
// Disable inlining inside SEH __try blocks.
if (isSEHTryScope()) {
Attrs =
Attrs.addAttribute(getLLVMContext(), llvm::AttributeList::FunctionIndex,
llvm::Attribute::NoInline);
}
// Decide whether to use a call or an invoke.
bool CannotThrow;
if (currentFunctionUsesSEHTry()) {
// SEH cares about asynchronous exceptions, so everything can "throw."
CannotThrow = false;
} else if (isCleanupPadScope() &&
EHPersonality::get(*this).isMSVCXXPersonality()) {
// The MSVC++ personality will implicitly terminate the program if an
// exception is thrown during a cleanup outside of a try/catch.
// We don't need to model anything in IR to get this behavior.
CannotThrow = true;
} else {
// Otherwise, nounwind call sites will never throw.
CannotThrow = Attrs.hasFnAttribute(llvm::Attribute::NoUnwind);
if (auto *FPtr = dyn_cast<llvm::Function>(CalleePtr))
if (FPtr->hasFnAttribute(llvm::Attribute::NoUnwind))
CannotThrow = true;
}
// If we made a temporary, be sure to clean up after ourselves. Note that we
// can't depend on being inside of an ExprWithCleanups, so we need to manually
// pop this cleanup later on. Being eager about this is OK, since this
// temporary is 'invisible' outside of the callee.
if (UnusedReturnSizePtr)
pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, SRetAlloca,
UnusedReturnSizePtr);
llvm::BasicBlock *InvokeDest = CannotThrow ? nullptr : getInvokeDest();
SmallVector<llvm::OperandBundleDef, 1> BundleList =
getBundlesForFunclet(CalleePtr);
if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(CurFuncDecl))
if (FD->hasAttr<StrictFPAttr>())
// All calls within a strictfp function are marked strictfp
Attrs =
Attrs.addAttribute(getLLVMContext(), llvm::AttributeList::FunctionIndex,
llvm::Attribute::StrictFP);
AssumeAlignedAttrEmitter AssumeAlignedAttrEmitter(*this, TargetDecl);
Attrs = AssumeAlignedAttrEmitter.TryEmitAsCallSiteAttribute(Attrs);
AllocAlignAttrEmitter AllocAlignAttrEmitter(*this, TargetDecl, CallArgs);
Attrs = AllocAlignAttrEmitter.TryEmitAsCallSiteAttribute(Attrs);
// Emit the actual call/invoke instruction.
llvm::CallBase *CI;
if (!InvokeDest) {
CI = Builder.CreateCall(IRFuncTy, CalleePtr, IRCallArgs, BundleList);
} else {
llvm::BasicBlock *Cont = createBasicBlock("invoke.cont");
CI = Builder.CreateInvoke(IRFuncTy, CalleePtr, Cont, InvokeDest, IRCallArgs,
BundleList);
EmitBlock(Cont);
}
if (callOrInvoke)
*callOrInvoke = CI;
// If this is within a function that has the guard(nocf) attribute and is an
// indirect call, add the "guard_nocf" attribute to this call to indicate that
// Control Flow Guard checks should not be added, even if the call is inlined.
if (const auto *FD = dyn_cast_or_null<FunctionDecl>(CurFuncDecl)) {
if (const auto *A = FD->getAttr<CFGuardAttr>()) {
if (A->getGuard() == CFGuardAttr::GuardArg::nocf && !CI->getCalledFunction())
Attrs = Attrs.addAttribute(
getLLVMContext(), llvm::AttributeList::FunctionIndex, "guard_nocf");
}
}
// Apply the attributes and calling convention.
CI->setAttributes(Attrs);
CI->setCallingConv(static_cast<llvm::CallingConv::ID>(CallingConv));
// Apply various metadata.
if (!CI->getType()->isVoidTy())
CI->setName("call");
// Update largest vector width from the return type.
if (auto *VT = dyn_cast<llvm::VectorType>(CI->getType()))
LargestVectorWidth =
std::max((uint64_t)LargestVectorWidth,
VT->getPrimitiveSizeInBits().getKnownMinSize());
// Insert instrumentation or attach profile metadata at indirect call sites.
// For more details, see the comment before the definition of
// IPVK_IndirectCallTarget in InstrProfData.inc.
if (!CI->getCalledFunction())
PGO.valueProfile(Builder, llvm::IPVK_IndirectCallTarget,
CI, CalleePtr);
// 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(CI);
// Suppress tail calls if requested.
if (llvm::CallInst *Call = dyn_cast<llvm::CallInst>(CI)) {
if (TargetDecl && TargetDecl->hasAttr<NotTailCalledAttr>())
Call->setTailCallKind(llvm::CallInst::TCK_NoTail);
}
// Add metadata for calls to MSAllocator functions
if (getDebugInfo() && TargetDecl &&
TargetDecl->hasAttr<MSAllocatorAttr>())
getDebugInfo()->addHeapAllocSiteMetadata(CI, RetTy->getPointeeType(), Loc);
// 4. Finish the call.
// 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 (CI->doesNotReturn()) {
if (UnusedReturnSizePtr)
PopCleanupBlock();
// Strip away the noreturn attribute to better diagnose unreachable UB.
if (SanOpts.has(SanitizerKind::Unreachable)) {
// Also remove from function since CallBase::hasFnAttr additionally checks
// attributes of the called function.
if (auto *F = CI->getCalledFunction())
F->removeFnAttr(llvm::Attribute::NoReturn);
CI->removeAttribute(llvm::AttributeList::FunctionIndex,
llvm::Attribute::NoReturn);
// Avoid incompatibility with ASan which relies on the `noreturn`
// attribute to insert handler calls.
if (SanOpts.hasOneOf(SanitizerKind::Address |
SanitizerKind::KernelAddress)) {
SanitizerScope SanScope(this);
llvm::IRBuilder<>::InsertPointGuard IPGuard(Builder);
Builder.SetInsertPoint(CI);
auto *FnType = llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
llvm::FunctionCallee Fn =
CGM.CreateRuntimeFunction(FnType, "__asan_handle_no_return");
EmitNounwindRuntimeCall(Fn);
}
}
EmitUnreachable(Loc);
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);
}
// Perform the swifterror writeback.
if (swiftErrorTemp.isValid()) {
llvm::Value *errorResult = Builder.CreateLoad(swiftErrorTemp);
Builder.CreateStore(errorResult, swiftErrorArg);
}
// Emit any call-associated 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);
// Extract the return value.
RValue Ret = [&] {
switch (RetAI.getKind()) {
case ABIArgInfo::CoerceAndExpand: {
auto coercionType = RetAI.getCoerceAndExpandType();
Address addr = SRetPtr;
addr = Builder.CreateElementBitCast(addr, coercionType);
assert(CI->getType() == RetAI.getUnpaddedCoerceAndExpandType());
bool requiresExtract = isa<llvm::StructType>(CI->getType());
unsigned unpaddedIndex = 0;
for (unsigned i = 0, e = coercionType->getNumElements(); i != e; ++i) {
llvm::Type *eltType = coercionType->getElementType(i);
if (ABIArgInfo::isPaddingForCoerceAndExpand(eltType)) continue;
Address eltAddr = Builder.CreateStructGEP(addr, i);
llvm::Value *elt = CI;
if (requiresExtract)
elt = Builder.CreateExtractValue(elt, unpaddedIndex++);
else
assert(unpaddedIndex == 0);
Builder.CreateStore(elt, eltAddr);
}
// FALLTHROUGH
LLVM_FALLTHROUGH;
}
case ABIArgInfo::InAlloca:
case ABIArgInfo::Indirect: {
RValue ret = convertTempToRValue(SRetPtr, RetTy, SourceLocation());
if (UnusedReturnSizePtr)
PopCleanupBlock();
return ret;
}
case ABIArgInfo::Ignore:
// If we are ignoring an argument that had a result, make sure to
// construct the appropriate return value for our caller.
return GetUndefRValue(RetTy);
case ABIArgInfo::Extend:
case ABIArgInfo::Direct: {
llvm::Type *RetIRTy = ConvertType(RetTy);
if (RetAI.getCoerceToType() == RetIRTy && RetAI.getDirectOffset() == 0) {
switch (getEvaluationKind(RetTy)) {
case TEK_Complex: {
llvm::Value *Real = Builder.CreateExtractValue(CI, 0);
llvm::Value *Imag = Builder.CreateExtractValue(CI, 1);
return RValue::getComplex(std::make_pair(Real, Imag));
}
case TEK_Aggregate: {
Address DestPtr = ReturnValue.getValue();
bool DestIsVolatile = ReturnValue.isVolatile();
if (!DestPtr.isValid()) {
DestPtr = CreateMemTemp(RetTy, "agg.tmp");
DestIsVolatile = false;
}
EmitAggregateStore(CI, DestPtr, DestIsVolatile);
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");
}
Address DestPtr = ReturnValue.getValue();
bool DestIsVolatile = ReturnValue.isVolatile();
if (!DestPtr.isValid()) {
DestPtr = CreateMemTemp(RetTy, "coerce");
DestIsVolatile = false;
}
// If the value is offset in memory, apply the offset now.
Address StorePtr = emitAddressAtOffset(*this, DestPtr, RetAI);
CreateCoercedStore(CI, StorePtr, DestIsVolatile, *this);
return convertTempToRValue(DestPtr, RetTy, SourceLocation());
}
case ABIArgInfo::Expand:
case ABIArgInfo::IndirectAliased:
llvm_unreachable("Invalid ABI kind for return argument");
}
llvm_unreachable("Unhandled ABIArgInfo::Kind");
} ();
// Emit the assume_aligned check on the return value.
if (Ret.isScalar() && TargetDecl) {
AssumeAlignedAttrEmitter.EmitAsAnAssumption(Loc, RetTy, Ret);
AllocAlignAttrEmitter.EmitAsAnAssumption(Loc, RetTy, Ret);
}
// Explicitly call CallLifetimeEnd::Emit just to re-use the code even though
// we can't use the full cleanup mechanism.
for (CallLifetimeEnd &LifetimeEnd : CallLifetimeEndAfterCall)
LifetimeEnd.Emit(*this, /*Flags=*/{});
if (!ReturnValue.isExternallyDestructed() &&
RetTy.isDestructedType() == QualType::DK_nontrivial_c_struct)
pushDestroy(QualType::DK_nontrivial_c_struct, Ret.getAggregateAddress(),
RetTy);
return Ret;
}
CGCallee CGCallee::prepareConcreteCallee(CodeGenFunction &CGF) const {
if (isVirtual()) {
const CallExpr *CE = getVirtualCallExpr();
return CGF.CGM.getCXXABI().getVirtualFunctionPointer(
CGF, getVirtualMethodDecl(), getThisAddress(), getVirtualFunctionType(),
CE ? CE->getBeginLoc() : SourceLocation());
}
return *this;
}
/* VarArg handling */
Address CodeGenFunction::EmitVAArg(VAArgExpr *VE, Address &VAListAddr) {
VAListAddr = VE->isMicrosoftABI()
? EmitMSVAListRef(VE->getSubExpr())
: EmitVAListRef(VE->getSubExpr());
QualType Ty = VE->getType();
if (VE->isMicrosoftABI())
return CGM.getTypes().getABIInfo().EmitMSVAArg(*this, VAListAddr, Ty);
return CGM.getTypes().getABIInfo().EmitVAArg(*this, VAListAddr, Ty);
}