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//===--- CGExprCXX.cpp - Emit LLVM Code for C++ expressions ---------------===//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
// This contains code dealing with code generation of C++ expressions
#include "CodeGenFunction.h"
#include "CGCUDARuntime.h"
#include "CGCXXABI.h"
#include "CGDebugInfo.h"
#include "CGObjCRuntime.h"
#include "clang/CodeGen/CGFunctionInfo.h"
#include "clang/Frontend/CodeGenOptions.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/Intrinsics.h"
using namespace clang;
using namespace CodeGen;
RValue CodeGenFunction::EmitCXXMemberCall(const CXXMethodDecl *MD,
SourceLocation CallLoc,
llvm::Value *Callee,
ReturnValueSlot ReturnValue,
llvm::Value *This,
llvm::Value *ImplicitParam,
QualType ImplicitParamTy,
CallExpr::const_arg_iterator ArgBeg,
CallExpr::const_arg_iterator ArgEnd) {
assert(MD->isInstance() &&
"Trying to emit a member call expr on a static method!");
// C++11 [class.mfct.non-static]p2:
// If a non-static member function of a class X is called for an object that
// is not of type X, or of a type derived from X, the behavior is undefined.
EmitTypeCheck(isa<CXXConstructorDecl>(MD) ? TCK_ConstructorCall
: TCK_MemberCall,
CallLoc, This, getContext().getRecordType(MD->getParent()));
CallArgList Args;
// Push the this ptr.
Args.add(RValue::get(This), MD->getThisType(getContext()));
// If there is an implicit parameter (e.g. VTT), emit it.
if (ImplicitParam) {
Args.add(RValue::get(ImplicitParam), ImplicitParamTy);
const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>();
RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, Args.size());
// And the rest of the call args.
EmitCallArgs(Args, FPT, ArgBeg, ArgEnd);
return EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required),
Callee, ReturnValue, Args, MD);
static CXXRecordDecl *getCXXRecord(const Expr *E) {
QualType T = E->getType();
if (const PointerType *PTy = T->getAs<PointerType>())
T = PTy->getPointeeType();
const RecordType *Ty = T->castAs<RecordType>();
return cast<CXXRecordDecl>(Ty->getDecl());
// Note: This function also emit constructor calls to support a MSVC
// extensions allowing explicit constructor function call.
RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE,
ReturnValueSlot ReturnValue) {
const Expr *callee = CE->getCallee()->IgnoreParens();
if (isa<BinaryOperator>(callee))
return EmitCXXMemberPointerCallExpr(CE, ReturnValue);
const MemberExpr *ME = cast<MemberExpr>(callee);
const CXXMethodDecl *MD = cast<CXXMethodDecl>(ME->getMemberDecl());
if (MD->isStatic()) {
// The method is static, emit it as we would a regular call.
llvm::Value *Callee = CGM.GetAddrOfFunction(MD);
return EmitCall(getContext().getPointerType(MD->getType()), Callee,
CE->getLocStart(), ReturnValue, CE->arg_begin(),
// Compute the object pointer.
const Expr *Base = ME->getBase();
bool CanUseVirtualCall = MD->isVirtual() && !ME->hasQualifier();
const CXXMethodDecl *DevirtualizedMethod = NULL;
if (CanUseVirtualCall && CanDevirtualizeMemberFunctionCall(Base, MD)) {
const CXXRecordDecl *BestDynamicDecl = Base->getBestDynamicClassType();
DevirtualizedMethod = MD->getCorrespondingMethodInClass(BestDynamicDecl);
const CXXRecordDecl *DevirtualizedClass = DevirtualizedMethod->getParent();
const Expr *Inner = Base->ignoreParenBaseCasts();
if (getCXXRecord(Inner) == DevirtualizedClass)
// If the class of the Inner expression is where the dynamic method
// is defined, build the this pointer from it.
Base = Inner;
else if (getCXXRecord(Base) != DevirtualizedClass) {
// If the method is defined in a class that is not the best dynamic
// one or the one of the full expression, we would have to build
// a derived-to-base cast to compute the correct this pointer, but
// we don't have support for that yet, so do a virtual call.
DevirtualizedMethod = NULL;
// If the return types are not the same, this might be a case where more
// code needs to run to compensate for it. For example, the derived
// method might return a type that inherits form from the return
// type of MD and has a prefix.
// For now we just avoid devirtualizing these covariant cases.
if (DevirtualizedMethod &&
DevirtualizedMethod->getReturnType().getCanonicalType() !=
DevirtualizedMethod = NULL;
llvm::Value *This;
if (ME->isArrow())
This = EmitScalarExpr(Base);
This = EmitLValue(Base).getAddress();
if (MD->isTrivial()) {
if (isa<CXXDestructorDecl>(MD)) return RValue::get(0);
if (isa<CXXConstructorDecl>(MD) &&
return RValue::get(0);
if (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()) {
// We don't like to generate the trivial copy/move assignment operator
// when it isn't necessary; just produce the proper effect here.
llvm::Value *RHS = EmitLValue(*CE->arg_begin()).getAddress();
EmitAggregateAssign(This, RHS, CE->getType());
return RValue::get(This);
if (isa<CXXConstructorDecl>(MD) &&
cast<CXXConstructorDecl>(MD)->isCopyOrMoveConstructor()) {
// Trivial move and copy ctor are the same.
llvm::Value *RHS = EmitLValue(*CE->arg_begin()).getAddress();
EmitSynthesizedCXXCopyCtorCall(cast<CXXConstructorDecl>(MD), This, RHS,
CE->arg_begin(), CE->arg_end());
return RValue::get(This);
llvm_unreachable("unknown trivial member function");
// Compute the function type we're calling.
const CXXMethodDecl *CalleeDecl = DevirtualizedMethod ? DevirtualizedMethod : MD;
const CGFunctionInfo *FInfo = 0;
if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(CalleeDecl))
FInfo = &CGM.getTypes().arrangeCXXDestructor(Dtor,
else if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(CalleeDecl))
FInfo = &CGM.getTypes().arrangeCXXConstructorDeclaration(Ctor,
FInfo = &CGM.getTypes().arrangeCXXMethodDeclaration(CalleeDecl);
llvm::FunctionType *Ty = CGM.getTypes().GetFunctionType(*FInfo);
// C++ [class.virtual]p12:
// Explicit qualification with the scope operator (5.1) suppresses the
// virtual call mechanism.
// We also don't emit a virtual call if the base expression has a record type
// because then we know what the type is.
bool UseVirtualCall = CanUseVirtualCall && !DevirtualizedMethod;
llvm::Value *Callee;
if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(MD)) {
assert(CE->arg_begin() == CE->arg_end() &&
"Destructor shouldn't have explicit parameters");
assert(ReturnValue.isNull() && "Destructor shouldn't have return value");
if (UseVirtualCall) {
CGM.getCXXABI().EmitVirtualDestructorCall(*this, Dtor, Dtor_Complete,
CE->getExprLoc(), This);
} else {
if (getLangOpts().AppleKext &&
MD->isVirtual() &&
Callee = BuildAppleKextVirtualCall(MD, ME->getQualifier(), Ty);
else if (!DevirtualizedMethod)
Callee = CGM.GetAddrOfCXXDestructor(Dtor, Dtor_Complete, FInfo, Ty);
else {
const CXXDestructorDecl *DDtor =
Callee = CGM.GetAddrOfFunction(GlobalDecl(DDtor, Dtor_Complete), Ty);
EmitCXXMemberCall(MD, CE->getExprLoc(), Callee, ReturnValue, This,
/*ImplicitParam=*/0, QualType(), 0, 0);
return RValue::get(0);
if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(MD)) {
Callee = CGM.GetAddrOfFunction(GlobalDecl(Ctor, Ctor_Complete), Ty);
} else if (UseVirtualCall) {
Callee = CGM.getCXXABI().getVirtualFunctionPointer(*this, MD, This, Ty);
} else {
if (getLangOpts().AppleKext &&
MD->isVirtual() &&
Callee = BuildAppleKextVirtualCall(MD, ME->getQualifier(), Ty);
else if (!DevirtualizedMethod)
Callee = CGM.GetAddrOfFunction(MD, Ty);
else {
Callee = CGM.GetAddrOfFunction(DevirtualizedMethod, Ty);
if (MD->isVirtual()) {
This = CGM.getCXXABI().adjustThisArgumentForVirtualFunctionCall(
*this, MD, This, UseVirtualCall);
return EmitCXXMemberCall(MD, CE->getExprLoc(), Callee, ReturnValue, This,
/*ImplicitParam=*/0, QualType(),
CE->arg_begin(), CE->arg_end());
CodeGenFunction::EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
ReturnValueSlot ReturnValue) {
const BinaryOperator *BO =
const Expr *BaseExpr = BO->getLHS();
const Expr *MemFnExpr = BO->getRHS();
const MemberPointerType *MPT =
const FunctionProtoType *FPT =
const CXXRecordDecl *RD =
// Get the member function pointer.
llvm::Value *MemFnPtr = EmitScalarExpr(MemFnExpr);
// Emit the 'this' pointer.
llvm::Value *This;
if (BO->getOpcode() == BO_PtrMemI)
This = EmitScalarExpr(BaseExpr);
This = EmitLValue(BaseExpr).getAddress();
EmitTypeCheck(TCK_MemberCall, E->getExprLoc(), This,
QualType(MPT->getClass(), 0));
// Ask the ABI to load the callee. Note that This is modified.
llvm::Value *Callee =
CGM.getCXXABI().EmitLoadOfMemberFunctionPointer(*this, BO, This, MemFnPtr, MPT);
CallArgList Args;
QualType ThisType =
// Push the this ptr.
Args.add(RValue::get(This), ThisType);
RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, 1);
// And the rest of the call args
EmitCallArgs(Args, FPT, E->arg_begin(), E->arg_end());
return EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required),
Callee, ReturnValue, Args);
CodeGenFunction::EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E,
const CXXMethodDecl *MD,
ReturnValueSlot ReturnValue) {
assert(MD->isInstance() &&
"Trying to emit a member call expr on a static method!");
LValue LV = EmitLValue(E->getArg(0));
llvm::Value *This = LV.getAddress();
if ((MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()) &&
MD->isTrivial()) {
llvm::Value *Src = EmitLValue(E->getArg(1)).getAddress();
QualType Ty = E->getType();
EmitAggregateAssign(This, Src, Ty);
return RValue::get(This);
llvm::Value *Callee = EmitCXXOperatorMemberCallee(E, MD, This);
return EmitCXXMemberCall(MD, E->getExprLoc(), Callee, ReturnValue, This,
/*ImplicitParam=*/0, QualType(),
E->arg_begin() + 1, E->arg_end());
RValue CodeGenFunction::EmitCUDAKernelCallExpr(const CUDAKernelCallExpr *E,
ReturnValueSlot ReturnValue) {
return CGM.getCUDARuntime().EmitCUDAKernelCallExpr(*this, E, ReturnValue);
static void EmitNullBaseClassInitialization(CodeGenFunction &CGF,
llvm::Value *DestPtr,
const CXXRecordDecl *Base) {
if (Base->isEmpty())
DestPtr = CGF.EmitCastToVoidPtr(DestPtr);
const ASTRecordLayout &Layout = CGF.getContext().getASTRecordLayout(Base);
CharUnits Size = Layout.getNonVirtualSize();
CharUnits Align = Layout.getNonVirtualAlignment();
llvm::Value *SizeVal = CGF.CGM.getSize(Size);
// If the type contains a pointer to data member we can't memset it to zero.
// Instead, create a null constant and copy it to the destination.
// TODO: there are other patterns besides zero that we can usefully memset,
// like -1, which happens to be the pattern used by member-pointers.
// TODO: isZeroInitializable can be over-conservative in the case where a
// virtual base contains a member pointer.
if (!CGF.CGM.getTypes().isZeroInitializable(Base)) {
llvm::Constant *NullConstant = CGF.CGM.EmitNullConstantForBase(Base);
llvm::GlobalVariable *NullVariable =
new llvm::GlobalVariable(CGF.CGM.getModule(), NullConstant->getType(),
NullConstant, Twine());
llvm::Value *SrcPtr = CGF.EmitCastToVoidPtr(NullVariable);
// Get and call the appropriate llvm.memcpy overload.
CGF.Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, Align.getQuantity());
// Otherwise, just memset the whole thing to zero. This is legal
// because in LLVM, all default initializers (other than the ones we just
// handled above) are guaranteed to have a bit pattern of all zeros.
CGF.Builder.CreateMemSet(DestPtr, CGF.Builder.getInt8(0), SizeVal,
CodeGenFunction::EmitCXXConstructExpr(const CXXConstructExpr *E,
AggValueSlot Dest) {
assert(!Dest.isIgnored() && "Must have a destination!");
const CXXConstructorDecl *CD = E->getConstructor();
// If we require zero initialization before (or instead of) calling the
// constructor, as can be the case with a non-user-provided default
// constructor, emit the zero initialization now, unless destination is
// already zeroed.
if (E->requiresZeroInitialization() && !Dest.isZeroed()) {
switch (E->getConstructionKind()) {
case CXXConstructExpr::CK_Delegating:
case CXXConstructExpr::CK_Complete:
EmitNullInitialization(Dest.getAddr(), E->getType());
case CXXConstructExpr::CK_VirtualBase:
case CXXConstructExpr::CK_NonVirtualBase:
EmitNullBaseClassInitialization(*this, Dest.getAddr(), CD->getParent());
// If this is a call to a trivial default constructor, do nothing.
if (CD->isTrivial() && CD->isDefaultConstructor())
// Elide the constructor if we're constructing from a temporary.
// The temporary check is required because Sema sets this on NRVO
// returns.
if (getLangOpts().ElideConstructors && E->isElidable()) {
if (E->getArg(0)->isTemporaryObject(getContext(), CD->getParent())) {
EmitAggExpr(E->getArg(0), Dest);
if (const ConstantArrayType *arrayType
= getContext().getAsConstantArrayType(E->getType())) {
EmitCXXAggrConstructorCall(CD, arrayType, Dest.getAddr(),
E->arg_begin(), E->arg_end());
} else {
CXXCtorType Type = Ctor_Complete;
bool ForVirtualBase = false;
bool Delegating = false;
switch (E->getConstructionKind()) {
case CXXConstructExpr::CK_Delegating:
// We should be emitting a constructor; GlobalDecl will assert this
Type = CurGD.getCtorType();
Delegating = true;
case CXXConstructExpr::CK_Complete:
Type = Ctor_Complete;
case CXXConstructExpr::CK_VirtualBase:
ForVirtualBase = true;
// fall-through
case CXXConstructExpr::CK_NonVirtualBase:
Type = Ctor_Base;
// Call the constructor.
EmitCXXConstructorCall(CD, Type, ForVirtualBase, Delegating, Dest.getAddr(),
E->arg_begin(), E->arg_end());
CodeGenFunction::EmitSynthesizedCXXCopyCtor(llvm::Value *Dest,
llvm::Value *Src,
const Expr *Exp) {
if (const ExprWithCleanups *E = dyn_cast<ExprWithCleanups>(Exp))
Exp = E->getSubExpr();
assert(isa<CXXConstructExpr>(Exp) &&
"EmitSynthesizedCXXCopyCtor - unknown copy ctor expr");
const CXXConstructExpr* E = cast<CXXConstructExpr>(Exp);
const CXXConstructorDecl *CD = E->getConstructor();
RunCleanupsScope Scope(*this);
// If we require zero initialization before (or instead of) calling the
// constructor, as can be the case with a non-user-provided default
// constructor, emit the zero initialization now.
// FIXME. Do I still need this for a copy ctor synthesis?
if (E->requiresZeroInitialization())
EmitNullInitialization(Dest, E->getType());
&& "EmitSynthesizedCXXCopyCtor - Copied-in Array");
EmitSynthesizedCXXCopyCtorCall(CD, Dest, Src, E->arg_begin(), E->arg_end());
static CharUnits CalculateCookiePadding(CodeGenFunction &CGF,
const CXXNewExpr *E) {
if (!E->isArray())
return CharUnits::Zero();
// No cookie is required if the operator new[] being used is the
// reserved placement operator new[].
if (E->getOperatorNew()->isReservedGlobalPlacementOperator())
return CharUnits::Zero();
return CGF.CGM.getCXXABI().GetArrayCookieSize(E);
static llvm::Value *EmitCXXNewAllocSize(CodeGenFunction &CGF,
const CXXNewExpr *e,
unsigned minElements,
llvm::Value *&numElements,
llvm::Value *&sizeWithoutCookie) {
QualType type = e->getAllocatedType();
if (!e->isArray()) {
CharUnits typeSize = CGF.getContext().getTypeSizeInChars(type);
= llvm::ConstantInt::get(CGF.SizeTy, typeSize.getQuantity());
return sizeWithoutCookie;
// The width of size_t.
unsigned sizeWidth = CGF.SizeTy->getBitWidth();
// Figure out the cookie size.
llvm::APInt cookieSize(sizeWidth,
CalculateCookiePadding(CGF, e).getQuantity());
// Emit the array size expression.
// We multiply the size of all dimensions for NumElements.
// e.g for 'int[2][3]', ElemType is 'int' and NumElements is 6.
numElements = CGF.EmitScalarExpr(e->getArraySize());
// The number of elements can be have an arbitrary integer type;
// essentially, we need to multiply it by a constant factor, add a
// cookie size, and verify that the result is representable as a
// size_t. That's just a gloss, though, and it's wrong in one
// important way: if the count is negative, it's an error even if
// the cookie size would bring the total size >= 0.
bool isSigned
= e->getArraySize()->getType()->isSignedIntegerOrEnumerationType();
llvm::IntegerType *numElementsType
= cast<llvm::IntegerType>(numElements->getType());
unsigned numElementsWidth = numElementsType->getBitWidth();
// Compute the constant factor.
llvm::APInt arraySizeMultiplier(sizeWidth, 1);
while (const ConstantArrayType *CAT
= CGF.getContext().getAsConstantArrayType(type)) {
type = CAT->getElementType();
arraySizeMultiplier *= CAT->getSize();
CharUnits typeSize = CGF.getContext().getTypeSizeInChars(type);
llvm::APInt typeSizeMultiplier(sizeWidth, typeSize.getQuantity());
typeSizeMultiplier *= arraySizeMultiplier;
// This will be a size_t.
llvm::Value *size;
// If someone is doing 'new int[42]' there is no need to do a dynamic check.
// Don't bloat the -O0 code.
if (llvm::ConstantInt *numElementsC =
dyn_cast<llvm::ConstantInt>(numElements)) {
const llvm::APInt &count = numElementsC->getValue();
bool hasAnyOverflow = false;
// If 'count' was a negative number, it's an overflow.
if (isSigned && count.isNegative())
hasAnyOverflow = true;
// We want to do all this arithmetic in size_t. If numElements is
// wider than that, check whether it's already too big, and if so,
// overflow.
else if (numElementsWidth > sizeWidth &&
numElementsWidth - sizeWidth > count.countLeadingZeros())
hasAnyOverflow = true;
// Okay, compute a count at the right width.
llvm::APInt adjustedCount = count.zextOrTrunc(sizeWidth);
// If there is a brace-initializer, we cannot allocate fewer elements than
// there are initializers. If we do, that's treated like an overflow.
if (adjustedCount.ult(minElements))
hasAnyOverflow = true;
// Scale numElements by that. This might overflow, but we don't
// care because it only overflows if allocationSize does, too, and
// if that overflows then we shouldn't use this.
numElements = llvm::ConstantInt::get(CGF.SizeTy,
adjustedCount * arraySizeMultiplier);
// Compute the size before cookie, and track whether it overflowed.
bool overflow;
llvm::APInt allocationSize
= adjustedCount.umul_ov(typeSizeMultiplier, overflow);
hasAnyOverflow |= overflow;
// Add in the cookie, and check whether it's overflowed.
if (cookieSize != 0) {
// Save the current size without a cookie. This shouldn't be
// used if there was overflow.
sizeWithoutCookie = llvm::ConstantInt::get(CGF.SizeTy, allocationSize);
allocationSize = allocationSize.uadd_ov(cookieSize, overflow);
hasAnyOverflow |= overflow;
// On overflow, produce a -1 so operator new will fail.
if (hasAnyOverflow) {
size = llvm::Constant::getAllOnesValue(CGF.SizeTy);
} else {
size = llvm::ConstantInt::get(CGF.SizeTy, allocationSize);
// Otherwise, we might need to use the overflow intrinsics.
} else {
// There are up to five conditions we need to test for:
// 1) if isSigned, we need to check whether numElements is negative;
// 2) if numElementsWidth > sizeWidth, we need to check whether
// numElements is larger than something representable in size_t;
// 3) if minElements > 0, we need to check whether numElements is smaller
// than that.
// 4) we need to compute
// sizeWithoutCookie := numElements * typeSizeMultiplier
// and check whether it overflows; and
// 5) if we need a cookie, we need to compute
// size := sizeWithoutCookie + cookieSize
// and check whether it overflows.
llvm::Value *hasOverflow = 0;
// If numElementsWidth > sizeWidth, then one way or another, we're
// going to have to do a comparison for (2), and this happens to
// take care of (1), too.
if (numElementsWidth > sizeWidth) {
llvm::APInt threshold(numElementsWidth, 1);
threshold <<= sizeWidth;
llvm::Value *thresholdV
= llvm::ConstantInt::get(numElementsType, threshold);
hasOverflow = CGF.Builder.CreateICmpUGE(numElements, thresholdV);
numElements = CGF.Builder.CreateTrunc(numElements, CGF.SizeTy);
// Otherwise, if we're signed, we want to sext up to size_t.
} else if (isSigned) {
if (numElementsWidth < sizeWidth)
numElements = CGF.Builder.CreateSExt(numElements, CGF.SizeTy);
// If there's a non-1 type size multiplier, then we can do the
// signedness check at the same time as we do the multiply
// because a negative number times anything will cause an
// unsigned overflow. Otherwise, we have to do it here. But at least
// in this case, we can subsume the >= minElements check.
if (typeSizeMultiplier == 1)
hasOverflow = CGF.Builder.CreateICmpSLT(numElements,
llvm::ConstantInt::get(CGF.SizeTy, minElements));
// Otherwise, zext up to size_t if necessary.
} else if (numElementsWidth < sizeWidth) {
numElements = CGF.Builder.CreateZExt(numElements, CGF.SizeTy);
assert(numElements->getType() == CGF.SizeTy);
if (minElements) {
// Don't allow allocation of fewer elements than we have initializers.
if (!hasOverflow) {
hasOverflow = CGF.Builder.CreateICmpULT(numElements,
llvm::ConstantInt::get(CGF.SizeTy, minElements));
} else if (numElementsWidth > sizeWidth) {
// The other existing overflow subsumes this check.
// We do an unsigned comparison, since any signed value < -1 is
// taken care of either above or below.
hasOverflow = CGF.Builder.CreateOr(hasOverflow,
llvm::ConstantInt::get(CGF.SizeTy, minElements)));
size = numElements;
// Multiply by the type size if necessary. This multiplier
// includes all the factors for nested arrays.
// This step also causes numElements to be scaled up by the
// nested-array factor if necessary. Overflow on this computation
// can be ignored because the result shouldn't be used if
// allocation fails.
if (typeSizeMultiplier != 1) {
llvm::Value *umul_with_overflow
= CGF.CGM.getIntrinsic(llvm::Intrinsic::umul_with_overflow, CGF.SizeTy);
llvm::Value *tsmV =
llvm::ConstantInt::get(CGF.SizeTy, typeSizeMultiplier);
llvm::Value *result =
CGF.Builder.CreateCall2(umul_with_overflow, size, tsmV);
llvm::Value *overflowed = CGF.Builder.CreateExtractValue(result, 1);
if (hasOverflow)
hasOverflow = CGF.Builder.CreateOr(hasOverflow, overflowed);
hasOverflow = overflowed;
size = CGF.Builder.CreateExtractValue(result, 0);
// Also scale up numElements by the array size multiplier.
if (arraySizeMultiplier != 1) {
// If the base element type size is 1, then we can re-use the
// multiply we just did.
if (typeSize.isOne()) {
assert(arraySizeMultiplier == typeSizeMultiplier);
numElements = size;
// Otherwise we need a separate multiply.
} else {
llvm::Value *asmV =
llvm::ConstantInt::get(CGF.SizeTy, arraySizeMultiplier);
numElements = CGF.Builder.CreateMul(numElements, asmV);
} else {
// numElements doesn't need to be scaled.
assert(arraySizeMultiplier == 1);
// Add in the cookie size if necessary.
if (cookieSize != 0) {
sizeWithoutCookie = size;
llvm::Value *uadd_with_overflow
= CGF.CGM.getIntrinsic(llvm::Intrinsic::uadd_with_overflow, CGF.SizeTy);
llvm::Value *cookieSizeV = llvm::ConstantInt::get(CGF.SizeTy, cookieSize);
llvm::Value *result =
CGF.Builder.CreateCall2(uadd_with_overflow, size, cookieSizeV);
llvm::Value *overflowed = CGF.Builder.CreateExtractValue(result, 1);
if (hasOverflow)
hasOverflow = CGF.Builder.CreateOr(hasOverflow, overflowed);
hasOverflow = overflowed;
size = CGF.Builder.CreateExtractValue(result, 0);
// If we had any possibility of dynamic overflow, make a select to
// overwrite 'size' with an all-ones value, which should cause
// operator new to throw.
if (hasOverflow)
size = CGF.Builder.CreateSelect(hasOverflow,
if (cookieSize == 0)
sizeWithoutCookie = size;
assert(sizeWithoutCookie && "didn't set sizeWithoutCookie?");
return size;
static void StoreAnyExprIntoOneUnit(CodeGenFunction &CGF, const Expr *Init,
QualType AllocType, llvm::Value *NewPtr) {
// FIXME: Refactor with EmitExprAsInit.
CharUnits Alignment = CGF.getContext().getTypeAlignInChars(AllocType);
switch (CGF.getEvaluationKind(AllocType)) {
case TEK_Scalar:
CGF.EmitScalarInit(Init, 0, CGF.MakeAddrLValue(NewPtr, AllocType,
case TEK_Complex:
CGF.EmitComplexExprIntoLValue(Init, CGF.MakeAddrLValue(NewPtr, AllocType,
/*isInit*/ true);
case TEK_Aggregate: {
AggValueSlot Slot
= AggValueSlot::forAddr(NewPtr, Alignment, AllocType.getQualifiers(),
CGF.EmitAggExpr(Init, Slot);
llvm_unreachable("bad evaluation kind");
CodeGenFunction::EmitNewArrayInitializer(const CXXNewExpr *E,
QualType elementType,
llvm::Value *beginPtr,
llvm::Value *numElements) {
if (!E->hasInitializer())
return; // We have a POD type.
llvm::Value *explicitPtr = beginPtr;
// Find the end of the array, hoisted out of the loop.
llvm::Value *endPtr =
Builder.CreateInBoundsGEP(beginPtr, numElements, "array.end");
unsigned initializerElements = 0;
const Expr *Init = E->getInitializer();
llvm::AllocaInst *endOfInit = 0;
QualType::DestructionKind dtorKind = elementType.isDestructedType();
EHScopeStack::stable_iterator cleanup;
llvm::Instruction *cleanupDominator = 0;
// If the initializer is an initializer list, first do the explicit elements.
if (const InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) {
initializerElements = ILE->getNumInits();
// If this is a multi-dimensional array new, we will initialize multiple
// elements with each init list element.
QualType AllocType = E->getAllocatedType();
if (const ConstantArrayType *CAT = dyn_cast_or_null<ConstantArrayType>(
AllocType->getAsArrayTypeUnsafe())) {
unsigned AS = explicitPtr->getType()->getPointerAddressSpace();
llvm::Type *AllocPtrTy = ConvertTypeForMem(AllocType)->getPointerTo(AS);
explicitPtr = Builder.CreateBitCast(explicitPtr, AllocPtrTy);
initializerElements *= getContext().getConstantArrayElementCount(CAT);
// Enter a partial-destruction cleanup if necessary.
if (needsEHCleanup(dtorKind)) {
// In principle we could tell the cleanup where we are more
// directly, but the control flow can get so varied here that it
// would actually be quite complex. Therefore we go through an
// alloca.
endOfInit = CreateTempAlloca(beginPtr->getType(), "array.endOfInit");
cleanupDominator = Builder.CreateStore(beginPtr, endOfInit);
pushIrregularPartialArrayCleanup(beginPtr, endOfInit, elementType,
cleanup = EHStack.stable_begin();
for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i) {
// Tell the cleanup that it needs to destroy up to this
// element. TODO: some of these stores can be trivially
// observed to be unnecessary.
if (endOfInit) Builder.CreateStore(explicitPtr, endOfInit);
StoreAnyExprIntoOneUnit(*this, ILE->getInit(i),
ILE->getInit(i)->getType(), explicitPtr);
explicitPtr = Builder.CreateConstGEP1_32(explicitPtr, 1,
// The remaining elements are filled with the array filler expression.
Init = ILE->getArrayFiller();
explicitPtr = Builder.CreateBitCast(explicitPtr, beginPtr->getType());
// Create the continuation block.
llvm::BasicBlock *contBB = createBasicBlock("new.loop.end");
// If the number of elements isn't constant, we have to now check if there is
// anything left to initialize.
if (llvm::ConstantInt *constNum = dyn_cast<llvm::ConstantInt>(numElements)) {
// If all elements have already been initialized, skip the whole loop.
if (constNum->getZExtValue() <= initializerElements) {
// If there was a cleanup, deactivate it.
if (cleanupDominator)
DeactivateCleanupBlock(cleanup, cleanupDominator);
} else {
llvm::BasicBlock *nonEmptyBB = createBasicBlock("new.loop.nonempty");
llvm::Value *isEmpty = Builder.CreateICmpEQ(explicitPtr, endPtr,
Builder.CreateCondBr(isEmpty, contBB, nonEmptyBB);
// Enter the loop.
llvm::BasicBlock *entryBB = Builder.GetInsertBlock();
llvm::BasicBlock *loopBB = createBasicBlock("new.loop");
// Set up the current-element phi.
llvm::PHINode *curPtr =
Builder.CreatePHI(explicitPtr->getType(), 2, "array.cur");
curPtr->addIncoming(explicitPtr, entryBB);
// Store the new cleanup position for irregular cleanups.
if (endOfInit) Builder.CreateStore(curPtr, endOfInit);
// Enter a partial-destruction cleanup if necessary.
if (!cleanupDominator && needsEHCleanup(dtorKind)) {
pushRegularPartialArrayCleanup(beginPtr, curPtr, elementType,
cleanup = EHStack.stable_begin();
cleanupDominator = Builder.CreateUnreachable();
// Emit the initializer into this element.
StoreAnyExprIntoOneUnit(*this, Init, E->getAllocatedType(), curPtr);
// Leave the cleanup if we entered one.
if (cleanupDominator) {
DeactivateCleanupBlock(cleanup, cleanupDominator);
// FIXME: The code below intends to initialize the individual array base
// elements, one at a time - but when dealing with multi-dimensional arrays -
// the pointer arithmetic can get confused - so the fix below entails casting
// to the allocated type to ensure that we get the pointer arithmetic right.
// It seems like the right approach here, it to really initialize the
// individual array base elements one at a time since it'll generate less
// code. I think the problem is that the wrong type is being passed into
// StoreAnyExprIntoOneUnit, but directly fixing that doesn't really work,
// because the Init expression has the wrong type at this point.
// So... this is ok for a quick fix, but we can and should do a lot better
// here long-term.
// Advance to the next element by adjusting the pointer type as necessary.
// For new int[10][20][30], alloc type is int[20][30], base type is 'int'.
QualType AllocType = E->getAllocatedType();
llvm::Type *AllocPtrTy = ConvertTypeForMem(AllocType)->getPointerTo(
llvm::Value *curPtrAllocTy = Builder.CreateBitCast(curPtr, AllocPtrTy);
llvm::Value *nextPtrAllocTy =
Builder.CreateConstGEP1_32(curPtrAllocTy, 1, "");
// Cast it back to the base type so that we can compare it to the endPtr.
llvm::Value *nextPtr =
Builder.CreateBitCast(nextPtrAllocTy, endPtr->getType());
// Check whether we've gotten to the end of the array and, if so,
// exit the loop.
llvm::Value *isEnd = Builder.CreateICmpEQ(nextPtr, endPtr, "array.atend");
Builder.CreateCondBr(isEnd, contBB, loopBB);
curPtr->addIncoming(nextPtr, Builder.GetInsertBlock());
static void EmitZeroMemSet(CodeGenFunction &CGF, QualType T,
llvm::Value *NewPtr, llvm::Value *Size) {
CharUnits Alignment = CGF.getContext().getTypeAlignInChars(T);
CGF.Builder.CreateMemSet(NewPtr, CGF.Builder.getInt8(0), Size,
Alignment.getQuantity(), false);
static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E,
QualType ElementType,
llvm::Value *NewPtr,
llvm::Value *NumElements,
llvm::Value *AllocSizeWithoutCookie) {
const Expr *Init = E->getInitializer();
if (E->isArray()) {
if (const CXXConstructExpr *CCE = dyn_cast_or_null<CXXConstructExpr>(Init)){
CXXConstructorDecl *Ctor = CCE->getConstructor();
if (Ctor->isTrivial()) {
// If new expression did not specify value-initialization, then there
// is no initialization.
if (!CCE->requiresZeroInitialization() || Ctor->getParent()->isEmpty())
if (CGF.CGM.getTypes().isZeroInitializable(ElementType)) {
// Optimization: since zero initialization will just set the memory
// to all zeroes, generate a single memset to do it in one shot.
EmitZeroMemSet(CGF, ElementType, NewPtr, AllocSizeWithoutCookie);
CGF.EmitCXXAggrConstructorCall(Ctor, NumElements, NewPtr,
CCE->arg_begin(), CCE->arg_end(),
} else if (Init && isa<ImplicitValueInitExpr>(Init) &&
CGF.CGM.getTypes().isZeroInitializable(ElementType)) {
// Optimization: since zero initialization will just set the memory
// to all zeroes, generate a single memset to do it in one shot.
EmitZeroMemSet(CGF, ElementType, NewPtr, AllocSizeWithoutCookie);
CGF.EmitNewArrayInitializer(E, ElementType, NewPtr, NumElements);
if (!Init)
StoreAnyExprIntoOneUnit(CGF, Init, E->getAllocatedType(), NewPtr);
/// Emit a call to an operator new or operator delete function, as implicitly
/// created by new-expressions and delete-expressions.
static RValue EmitNewDeleteCall(CodeGenFunction &CGF,
const FunctionDecl *Callee,
const FunctionProtoType *CalleeType,
const CallArgList &Args) {
llvm::Instruction *CallOrInvoke;
llvm::Value *CalleeAddr = CGF.CGM.GetAddrOfFunction(Callee);
RValue RV =
CGF.EmitCall(CGF.CGM.getTypes().arrangeFreeFunctionCall(Args, CalleeType),
CalleeAddr, ReturnValueSlot(), Args,
Callee, &CallOrInvoke);
/// C++1y []p10:
/// [In a new-expression,] an implementation is allowed to omit a call
/// to a replaceable global allocation function.
/// We model such elidable calls with the 'builtin' attribute.
llvm::Function *Fn = dyn_cast<llvm::Function>(CalleeAddr);
if (Callee->isReplaceableGlobalAllocationFunction() &&
Fn && Fn->hasFnAttribute(llvm::Attribute::NoBuiltin)) {
// FIXME: Add addAttribute to CallSite.
if (llvm::CallInst *CI = dyn_cast<llvm::CallInst>(CallOrInvoke))
else if (llvm::InvokeInst *II = dyn_cast<llvm::InvokeInst>(CallOrInvoke))
llvm_unreachable("unexpected kind of call instruction");
return RV;
namespace {
/// A cleanup to call the given 'operator delete' function upon
/// abnormal exit from a new expression.
class CallDeleteDuringNew : public EHScopeStack::Cleanup {
size_t NumPlacementArgs;
const FunctionDecl *OperatorDelete;
llvm::Value *Ptr;
llvm::Value *AllocSize;
RValue *getPlacementArgs() { return reinterpret_cast<RValue*>(this+1); }
static size_t getExtraSize(size_t NumPlacementArgs) {
return NumPlacementArgs * sizeof(RValue);
CallDeleteDuringNew(size_t NumPlacementArgs,
const FunctionDecl *OperatorDelete,
llvm::Value *Ptr,
llvm::Value *AllocSize)
: NumPlacementArgs(NumPlacementArgs), OperatorDelete(OperatorDelete),
Ptr(Ptr), AllocSize(AllocSize) {}
void setPlacementArg(unsigned I, RValue Arg) {
assert(I < NumPlacementArgs && "index out of range");
getPlacementArgs()[I] = Arg;
void Emit(CodeGenFunction &CGF, Flags flags) override {
const FunctionProtoType *FPT
= OperatorDelete->getType()->getAs<FunctionProtoType>();
assert(FPT->getNumParams() == NumPlacementArgs + 1 ||
(FPT->getNumParams() == 2 && NumPlacementArgs == 0));
CallArgList DeleteArgs;
// The first argument is always a void*.
FunctionProtoType::param_type_iterator AI = FPT->param_type_begin();
DeleteArgs.add(RValue::get(Ptr), *AI++);
// A member 'operator delete' can take an extra 'size_t' argument.
if (FPT->getNumParams() == NumPlacementArgs + 2)
DeleteArgs.add(RValue::get(AllocSize), *AI++);
// Pass the rest of the arguments, which must match exactly.
for (unsigned I = 0; I != NumPlacementArgs; ++I)
DeleteArgs.add(getPlacementArgs()[I], *AI++);
// Call 'operator delete'.
EmitNewDeleteCall(CGF, OperatorDelete, FPT, DeleteArgs);
/// A cleanup to call the given 'operator delete' function upon
/// abnormal exit from a new expression when the new expression is
/// conditional.
class CallDeleteDuringConditionalNew : public EHScopeStack::Cleanup {
size_t NumPlacementArgs;
const FunctionDecl *OperatorDelete;
DominatingValue<RValue>::saved_type Ptr;
DominatingValue<RValue>::saved_type AllocSize;
DominatingValue<RValue>::saved_type *getPlacementArgs() {
return reinterpret_cast<DominatingValue<RValue>::saved_type*>(this+1);
static size_t getExtraSize(size_t NumPlacementArgs) {
return NumPlacementArgs * sizeof(DominatingValue<RValue>::saved_type);
CallDeleteDuringConditionalNew(size_t NumPlacementArgs,
const FunctionDecl *OperatorDelete,
DominatingValue<RValue>::saved_type Ptr,
DominatingValue<RValue>::saved_type AllocSize)
: NumPlacementArgs(NumPlacementArgs), OperatorDelete(OperatorDelete),
Ptr(Ptr), AllocSize(AllocSize) {}
void setPlacementArg(unsigned I, DominatingValue<RValue>::saved_type Arg) {
assert(I < NumPlacementArgs && "index out of range");
getPlacementArgs()[I] = Arg;
void Emit(CodeGenFunction &CGF, Flags flags) override {
const FunctionProtoType *FPT
= OperatorDelete->getType()->getAs<FunctionProtoType>();
assert(FPT->getNumParams() == NumPlacementArgs + 1 ||
(FPT->getNumParams() == 2 && NumPlacementArgs == 0));
CallArgList DeleteArgs;
// The first argument is always a void*.
FunctionProtoType::param_type_iterator AI = FPT->param_type_begin();
DeleteArgs.add(Ptr.restore(CGF), *AI++);
// A member 'operator delete' can take an extra 'size_t' argument.
if (FPT->getNumParams() == NumPlacementArgs + 2) {
RValue RV = AllocSize.restore(CGF);
DeleteArgs.add(RV, *AI++);
// Pass the rest of the arguments, which must match exactly.
for (unsigned I = 0; I != NumPlacementArgs; ++I) {
RValue RV = getPlacementArgs()[I].restore(CGF);
DeleteArgs.add(RV, *AI++);
// Call 'operator delete'.
EmitNewDeleteCall(CGF, OperatorDelete, FPT, DeleteArgs);
/// Enter a cleanup to call 'operator delete' if the initializer in a
/// new-expression throws.
static void EnterNewDeleteCleanup(CodeGenFunction &CGF,
const CXXNewExpr *E,
llvm::Value *NewPtr,
llvm::Value *AllocSize,
const CallArgList &NewArgs) {
// If we're not inside a conditional branch, then the cleanup will
// dominate and we can do the easier (and more efficient) thing.
if (!CGF.isInConditionalBranch()) {
CallDeleteDuringNew *Cleanup = CGF.EHStack
NewPtr, AllocSize);
for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I)
Cleanup->setPlacementArg(I, NewArgs[I+1].RV);
// Otherwise, we need to save all this stuff.
DominatingValue<RValue>::saved_type SavedNewPtr =
DominatingValue<RValue>::save(CGF, RValue::get(NewPtr));
DominatingValue<RValue>::saved_type SavedAllocSize =
DominatingValue<RValue>::save(CGF, RValue::get(AllocSize));
CallDeleteDuringConditionalNew *Cleanup = CGF.EHStack
for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I)
DominatingValue<RValue>::save(CGF, NewArgs[I+1].RV));
llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
// The element type being allocated.
QualType allocType = getContext().getBaseElementType(E->getAllocatedType());
// 1. Build a call to the allocation function.
FunctionDecl *allocator = E->getOperatorNew();
const FunctionProtoType *allocatorType =
CallArgList allocatorArgs;
// The allocation size is the first argument.
QualType sizeType = getContext().getSizeType();
// If there is a brace-initializer, cannot allocate fewer elements than inits.
unsigned minElements = 0;
if (E->isArray() && E->hasInitializer()) {
if (const InitListExpr *ILE = dyn_cast<InitListExpr>(E->getInitializer()))
minElements = ILE->getNumInits();
llvm::Value *numElements = 0;
llvm::Value *allocSizeWithoutCookie = 0;
llvm::Value *allocSize =
EmitCXXNewAllocSize(*this, E, minElements, numElements,
allocatorArgs.add(RValue::get(allocSize), sizeType);
// We start at 1 here because the first argument (the allocation size)
// has already been emitted.
EmitCallArgs(allocatorArgs, allocatorType->isVariadic(),
allocatorType->param_type_begin() + 1,
allocatorType->param_type_end(), E->placement_arg_begin(),
// Emit the allocation call. If the allocator is a global placement
// operator, just "inline" it directly.
RValue RV;
if (allocator->isReservedGlobalPlacementOperator()) {
assert(allocatorArgs.size() == 2);
RV = allocatorArgs[1].RV;
// TODO: kill any unnecessary computations done for the size
// argument.
} else {
RV = EmitNewDeleteCall(*this, allocator, allocatorType, allocatorArgs);
// Emit a null check on the allocation result if the allocation
// function is allowed to return null (because it has a non-throwing
// exception spec; for this part, we inline
// CXXNewExpr::shouldNullCheckAllocation()) and we have an
// interesting initializer.
bool nullCheck = allocatorType->isNothrow(getContext()) &&
(!allocType.isPODType(getContext()) || E->hasInitializer());
llvm::BasicBlock *nullCheckBB = 0;
llvm::BasicBlock *contBB = 0;
llvm::Value *allocation = RV.getScalarVal();
unsigned AS = allocation->getType()->getPointerAddressSpace();
// The null-check means that the initializer is conditionally
// evaluated.
ConditionalEvaluation conditional(*this);
if (nullCheck) {
nullCheckBB = Builder.GetInsertBlock();
llvm::BasicBlock *notNullBB = createBasicBlock("new.notnull");
contBB = createBasicBlock("new.cont");
llvm::Value *isNull = Builder.CreateIsNull(allocation, "new.isnull");
Builder.CreateCondBr(isNull, contBB, notNullBB);
// If there's an operator delete, enter a cleanup to call it if an
// exception is thrown.
EHScopeStack::stable_iterator operatorDeleteCleanup;
llvm::Instruction *cleanupDominator = 0;
if (E->getOperatorDelete() &&
!E->getOperatorDelete()->isReservedGlobalPlacementOperator()) {
EnterNewDeleteCleanup(*this, E, allocation, allocSize, allocatorArgs);
operatorDeleteCleanup = EHStack.stable_begin();
cleanupDominator = Builder.CreateUnreachable();
assert((allocSize == allocSizeWithoutCookie) ==
CalculateCookiePadding(*this, E).isZero());
if (allocSize != allocSizeWithoutCookie) {
allocation = CGM.getCXXABI().InitializeArrayCookie(*this, allocation,
E, allocType);
llvm::Type *elementPtrTy
= ConvertTypeForMem(allocType)->getPointerTo(AS);
llvm::Value *result = Builder.CreateBitCast(allocation, elementPtrTy);
EmitNewInitializer(*this, E, allocType, result, numElements,
if (E->isArray()) {
// NewPtr is a pointer to the base element type. If we're
// allocating an array of arrays, we'll need to cast back to the
// array pointer type.
llvm::Type *resultType = ConvertTypeForMem(E->getType());
if (result->getType() != resultType)
result = Builder.CreateBitCast(result, resultType);
// Deactivate the 'operator delete' cleanup if we finished
// initialization.
if (operatorDeleteCleanup.isValid()) {
DeactivateCleanupBlock(operatorDeleteCleanup, cleanupDominator);
if (nullCheck) {
llvm::BasicBlock *notNullBB = Builder.GetInsertBlock();
llvm::PHINode *PHI = Builder.CreatePHI(result->getType(), 2);
PHI->addIncoming(result, notNullBB);
result = PHI;
return result;
void CodeGenFunction::EmitDeleteCall(const FunctionDecl *DeleteFD,
llvm::Value *Ptr,
QualType DeleteTy) {
assert(DeleteFD->getOverloadedOperator() == OO_Delete);
const FunctionProtoType *DeleteFTy =
CallArgList DeleteArgs;
// Check if we need to pass the size to the delete operator.
llvm::Value *Size = 0;
QualType SizeTy;
if (DeleteFTy->getNumParams() == 2) {
SizeTy = DeleteFTy->getParamType(1);
CharUnits DeleteTypeSize = getContext().getTypeSizeInChars(DeleteTy);
Size = llvm::ConstantInt::get(ConvertType(SizeTy),
QualType ArgTy = DeleteFTy->getParamType(0);
llvm::Value *DeletePtr = Builder.CreateBitCast(Ptr, ConvertType(ArgTy));
DeleteArgs.add(RValue::get(DeletePtr), ArgTy);
if (Size)
DeleteArgs.add(RValue::get(Size), SizeTy);
// Emit the call to delete.
EmitNewDeleteCall(*this, DeleteFD, DeleteFTy, DeleteArgs);
namespace {
/// Calls the given 'operator delete' on a single object.
struct CallObjectDelete : EHScopeStack::Cleanup {
llvm::Value *Ptr;
const FunctionDecl *OperatorDelete;
QualType ElementType;
CallObjectDelete(llvm::Value *Ptr,
const FunctionDecl *OperatorDelete,
QualType ElementType)
: Ptr(Ptr), OperatorDelete(OperatorDelete), ElementType(ElementType) {}
void Emit(CodeGenFunction &CGF, Flags flags) override {
CGF.EmitDeleteCall(OperatorDelete, Ptr, ElementType);
/// Emit the code for deleting a single object.
static void EmitObjectDelete(CodeGenFunction &CGF,
const FunctionDecl *OperatorDelete,
llvm::Value *Ptr,
QualType ElementType,
bool UseGlobalDelete) {
// Find the destructor for the type, if applicable. If the
// destructor is virtual, we'll just emit the vcall and return.
const CXXDestructorDecl *Dtor = 0;
if (const RecordType *RT = ElementType->getAs<RecordType>()) {
CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
if (RD->hasDefinition() && !RD->hasTrivialDestructor()) {
Dtor = RD->getDestructor();
if (Dtor->isVirtual()) {
if (UseGlobalDelete) {
// If we're supposed to call the global delete, make sure we do so
// even if the destructor throws.
// Derive the complete-object pointer, which is what we need
// to pass to the deallocation function.
llvm::Value *completePtr =
CGF.CGM.getCXXABI().adjustToCompleteObject(CGF, Ptr, ElementType);
completePtr, OperatorDelete,
// FIXME: Provide a source location here.
CXXDtorType DtorType = UseGlobalDelete ? Dtor_Complete : Dtor_Deleting;
CGF.CGM.getCXXABI().EmitVirtualDestructorCall(CGF, Dtor, DtorType,
SourceLocation(), Ptr);
if (UseGlobalDelete) {
// Make sure that we call delete even if the dtor throws.
// This doesn't have to a conditional cleanup because we're going
// to pop it off in a second.
Ptr, OperatorDelete, ElementType);
if (Dtor)
CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete,
else if (CGF.getLangOpts().ObjCAutoRefCount &&
ElementType->isObjCLifetimeType()) {
switch (ElementType.getObjCLifetime()) {
case Qualifiers::OCL_None:
case Qualifiers::OCL_ExplicitNone:
case Qualifiers::OCL_Autoreleasing:
case Qualifiers::OCL_Strong: {
// Load the pointer value.
llvm::Value *PtrValue = CGF.Builder.CreateLoad(Ptr,
CGF.EmitARCRelease(PtrValue, ARCPreciseLifetime);
case Qualifiers::OCL_Weak:
namespace {
/// Calls the given 'operator delete' on an array of objects.
struct CallArrayDelete : EHScopeStack::Cleanup {
llvm::Value *Ptr;
const FunctionDecl *OperatorDelete;
llvm::Value *NumElements;
QualType ElementType;
CharUnits CookieSize;
CallArrayDelete(llvm::Value *Ptr,
const FunctionDecl *OperatorDelete,
llvm::Value *NumElements,
QualType ElementType,
CharUnits CookieSize)
: Ptr(Ptr), OperatorDelete(OperatorDelete), NumElements(NumElements),
ElementType(ElementType), CookieSize(CookieSize) {}
void Emit(CodeGenFunction &CGF, Flags flags) override {
const FunctionProtoType *DeleteFTy =
assert(DeleteFTy->getNumParams() == 1 || DeleteFTy->getNumParams() == 2);
CallArgList Args;
// Pass the pointer as the first argument.
QualType VoidPtrTy = DeleteFTy->getParamType(0);
llvm::Value *DeletePtr
= CGF.Builder.CreateBitCast(Ptr, CGF.ConvertType(VoidPtrTy));
Args.add(RValue::get(DeletePtr), VoidPtrTy);
// Pass the original requested size as the second argument.
if (DeleteFTy->getNumParams() == 2) {
QualType size_t = DeleteFTy->getParamType(1);
llvm::IntegerType *SizeTy
= cast<llvm::IntegerType>(CGF.ConvertType(size_t));
CharUnits ElementTypeSize =
// The size of an element, multiplied by the number of elements.
llvm::Value *Size
= llvm::ConstantInt::get(SizeTy, ElementTypeSize.getQuantity());
Size = CGF.Builder.CreateMul(Size, NumElements);
// Plus the size of the cookie if applicable.
if (!CookieSize.isZero()) {
llvm::Value *CookieSizeV
= llvm::ConstantInt::get(SizeTy, CookieSize.getQuantity());
Size = CGF.Builder.CreateAdd(Size, CookieSizeV);
Args.add(RValue::get(Size), size_t);
// Emit the call to delete.
EmitNewDeleteCall(CGF, OperatorDelete, DeleteFTy, Args);
/// Emit the code for deleting an array of objects.
static void EmitArrayDelete(CodeGenFunction &CGF,
const CXXDeleteExpr *E,
llvm::Value *deletedPtr,
QualType elementType) {
llvm::Value *numElements = 0;
llvm::Value *allocatedPtr = 0;
CharUnits cookieSize;
CGF.CGM.getCXXABI().ReadArrayCookie(CGF, deletedPtr, E, elementType,
numElements, allocatedPtr, cookieSize);
assert(allocatedPtr && "ReadArrayCookie didn't set allocated pointer");
// Make sure that we call delete even if one of the dtors throws.
const FunctionDecl *operatorDelete = E->getOperatorDelete();
allocatedPtr, operatorDelete,
numElements, elementType,
// Destroy the elements.
if (QualType::DestructionKind dtorKind = elementType.isDestructedType()) {
assert(numElements && "no element count for a type with a destructor!");
llvm::Value *arrayEnd =
CGF.Builder.CreateInBoundsGEP(deletedPtr, numElements, "delete.end");
// Note that it is legal to allocate a zero-length array, and we
// can never fold the check away because the length should always
// come from a cookie.
CGF.emitArrayDestroy(deletedPtr, arrayEnd, elementType,
/*checkZeroLength*/ true,
// Pop the cleanup block.
void CodeGenFunction::EmitCXXDeleteExpr(const CXXDeleteExpr *E) {
const Expr *Arg = E->getArgument();
llvm::Value *Ptr = EmitScalarExpr(Arg);
// Null check the pointer.
llvm::BasicBlock *DeleteNotNull = createBasicBlock("delete.notnull");
llvm::BasicBlock *DeleteEnd = createBasicBlock("delete.end");
llvm::Value *IsNull = Builder.CreateIsNull(Ptr, "isnull");
Builder.CreateCondBr(IsNull, DeleteEnd, DeleteNotNull);
// We might be deleting a pointer to array. If so, GEP down to the
// first non-array element.
// (this assumes that A(*)[3][7] is converted to [3 x [7 x %A]]*)
QualType DeleteTy = Arg->getType()->getAs<PointerType>()->getPointeeType();
if (DeleteTy->isConstantArrayType()) {
llvm::Value *Zero = Builder.getInt32(0);
SmallVector<llvm::Value*,8> GEP;
GEP.push_back(Zero); // point at the outermost array
// For each layer of array type we're pointing at:
while (const ConstantArrayType *Arr
= getContext().getAsConstantArrayType(DeleteTy)) {
// 1. Unpeel the array type.
DeleteTy = Arr->getElementType();
// 2. GEP to the first element of the array.
Ptr = Builder.CreateInBoundsGEP(Ptr, GEP, "del.first");
assert(ConvertTypeForMem(DeleteTy) ==
if (E->isArrayForm()) {
EmitArrayDelete(*this, E, Ptr, DeleteTy);
} else {
EmitObjectDelete(*this, E->getOperatorDelete(), Ptr, DeleteTy,
static llvm::Constant *getBadTypeidFn(CodeGenFunction &CGF) {
// void __cxa_bad_typeid();
llvm::FunctionType *FTy = llvm::FunctionType::get(CGF.VoidTy, false);
return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_bad_typeid");
static void EmitBadTypeidCall(CodeGenFunction &CGF) {
llvm::Value *Fn = getBadTypeidFn(CGF);
static llvm::Value *EmitTypeidFromVTable(CodeGenFunction &CGF,
const Expr *E,
llvm::Type *StdTypeInfoPtrTy) {
// Get the vtable pointer.
llvm::Value *ThisPtr = CGF.EmitLValue(E).getAddress();
// C++ [expr.typeid]p2:
// If the glvalue expression is obtained by applying the unary * operator to
// a pointer and the pointer is a null pointer value, the typeid expression
// throws the std::bad_typeid exception.
if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E->IgnoreParens())) {
if (UO->getOpcode() == UO_Deref) {
llvm::BasicBlock *BadTypeidBlock =
llvm::BasicBlock *EndBlock =
llvm::Value *IsNull = CGF.Builder.CreateIsNull(ThisPtr);
CGF.Builder.CreateCondBr(IsNull, BadTypeidBlock, EndBlock);
llvm::Value *Value = CGF.GetVTablePtr(ThisPtr,
// Load the type info.
Value = CGF.Builder.CreateConstInBoundsGEP1_64(Value, -1ULL);
return CGF.Builder.CreateLoad(Value);
llvm::Value *CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) {
llvm::Type *StdTypeInfoPtrTy =
if (E->isTypeOperand()) {
llvm::Constant *TypeInfo =
return Builder.CreateBitCast(TypeInfo, StdTypeInfoPtrTy);
// C++ [expr.typeid]p2:
// When typeid is applied to a glvalue expression whose type is a
// polymorphic class type, the result refers to a std::type_info object
// representing the type of the most derived object (that is, the dynamic
// type) to which the glvalue refers.
if (E->isPotentiallyEvaluated())
return EmitTypeidFromVTable(*this, E->getExprOperand(),
QualType OperandTy = E->getExprOperand()->getType();
return Builder.CreateBitCast(CGM.GetAddrOfRTTIDescriptor(OperandTy),
static llvm::Constant *getDynamicCastFn(CodeGenFunction &CGF) {
// void *__dynamic_cast(const void *sub,
// const abi::__class_type_info *src,
// const abi::__class_type_info *dst,
// std::ptrdiff_t src2dst_offset);
llvm::Type *Int8PtrTy = CGF.Int8PtrTy;
llvm::Type *PtrDiffTy =
llvm::Type *Args[4] = { Int8PtrTy, Int8PtrTy, Int8PtrTy, PtrDiffTy };
llvm::FunctionType *FTy = llvm::FunctionType::get(Int8PtrTy, Args, false);
// Mark the function as nounwind readonly.
llvm::Attribute::AttrKind FuncAttrs[] = { llvm::Attribute::NoUnwind,
llvm::Attribute::ReadOnly };
llvm::AttributeSet Attrs = llvm::AttributeSet::get(
CGF.getLLVMContext(), llvm::AttributeSet::FunctionIndex, FuncAttrs);
return CGF.CGM.CreateRuntimeFunction(FTy, "__dynamic_cast", Attrs);
static llvm::Constant *getBadCastFn(CodeGenFunction &CGF) {
// void __cxa_bad_cast();
llvm::FunctionType *FTy = llvm::FunctionType::get(CGF.VoidTy, false);
return CGF.CGM.CreateRuntimeFunction(FTy, "__cxa_bad_cast");
static void EmitBadCastCall(CodeGenFunction &CGF) {
llvm::Value *Fn = getBadCastFn(CGF);
/// \brief Compute the src2dst_offset hint as described in the
/// Itanium C++ ABI [2.9.7]
static CharUnits computeOffsetHint(ASTContext &Context,
const CXXRecordDecl *Src,
const CXXRecordDecl *Dst) {
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
// If Dst is not derived from Src we can skip the whole computation below and
// return that Src is not a public base of Dst. Record all inheritance paths.
if (!Dst->isDerivedFrom(Src, Paths))
return CharUnits::fromQuantity(-2ULL);
unsigned NumPublicPaths = 0;
CharUnits Offset;
// Now walk all possible inheritance paths.
for (CXXBasePaths::paths_iterator I = Paths.begin(), E = Paths.end();
I != E; ++I) {
if (I->Access != AS_public) // Ignore non-public inheritance.
for (CXXBasePath::iterator J = I->begin(), JE = I->end(); J != JE; ++J) {
// If the path contains a virtual base class we can't give any hint.
// -1: no hint.
if (J->Base->isVirtual())
return CharUnits::fromQuantity(-1ULL);
if (NumPublicPaths > 1) // Won't use offsets, skip computation.
// Accumulate the base class offsets.
const ASTRecordLayout &L = Context.getASTRecordLayout(J->Class);
Offset += L.getBaseClassOffset(J->Base->getType()->getAsCXXRecordDecl());
// -2: Src is not a public base of Dst.
if (NumPublicPaths == 0)
return CharUnits::fromQuantity(-2ULL);
// -3: Src is a multiple public base type but never a virtual base type.
if (NumPublicPaths > 1)
return CharUnits::fromQuantity(-3ULL);
// Otherwise, the Src type is a unique public nonvirtual base type of Dst.
// Return the offset of Src from the origin of Dst.
return Offset;
static llvm::Value *
EmitDynamicCastCall(CodeGenFunction &CGF, llvm::Value *Value,
QualType SrcTy, QualType DestTy,
llvm::BasicBlock *CastEnd) {
llvm::Type *PtrDiffLTy =
llvm::Type *DestLTy = CGF.ConvertType(DestTy);
if (const PointerType *PTy = DestTy->getAs<PointerType>()) {
if (PTy->getPointeeType()->isVoidType()) {
// C++ [expr.dynamic.cast]p7:
// If T is "pointer to cv void," then the result is a pointer to the
// most derived object pointed to by v.
// Get the vtable pointer.
llvm::Value *VTable = CGF.GetVTablePtr(Value, PtrDiffLTy->getPointerTo());
// Get the offset-to-top from the vtable.
llvm::Value *OffsetToTop =
CGF.Builder.CreateConstInBoundsGEP1_64(VTable, -2ULL);
OffsetToTop = CGF.Builder.CreateLoad(OffsetToTop, "");
// Finally, add the offset to the pointer.
Value = CGF.EmitCastToVoidPtr(Value);
Value = CGF.Builder.CreateInBoundsGEP(Value, OffsetToTop);
return CGF.Builder.CreateBitCast(Value, DestLTy);
QualType SrcRecordTy;
QualType DestRecordTy;
if (const PointerType *DestPTy = DestTy->getAs<PointerType>()) {
SrcRecordTy = SrcTy->castAs<PointerType>()->getPointeeType();
DestRecordTy = DestPTy->getPointeeType();
} else {
SrcRecordTy = SrcTy;
DestRecordTy = DestTy->castAs<ReferenceType>()->getPointeeType();
assert(SrcRecordTy->isRecordType() && "source type must be a record type!");
assert(DestRecordTy->isRecordType() && "dest type must be a record type!");
llvm::Value *SrcRTTI =
llvm::Value *DestRTTI =
// Compute the offset hint.
const CXXRecordDecl *SrcDecl = SrcRecordTy->getAsCXXRecordDecl();
const CXXRecordDecl *DestDecl = DestRecordTy->getAsCXXRecordDecl();
llvm::Value *OffsetHint =
computeOffsetHint(CGF.getContext(), SrcDecl,
// Emit the call to __dynamic_cast.
Value = CGF.EmitCastToVoidPtr(Value);
llvm::Value *args[] = { Value, SrcRTTI, DestRTTI, OffsetHint };
Value = CGF.EmitNounwindRuntimeCall(getDynamicCastFn(CGF), args);
Value = CGF.Builder.CreateBitCast(Value, DestLTy);
/// C++ [expr.dynamic.cast]p9:
/// A failed cast to reference type throws std::bad_cast
if (DestTy->isReferenceType()) {
llvm::BasicBlock *BadCastBlock =
llvm::Value *IsNull = CGF.Builder.CreateIsNull(Value);
CGF.Builder.CreateCondBr(IsNull, BadCastBlock, CastEnd);
return Value;
static llvm::Value *EmitDynamicCastToNull(CodeGenFunction &CGF,
QualType DestTy) {
llvm::Type *DestLTy = CGF.ConvertType(DestTy);
if (DestTy->isPointerType())
return llvm::Constant::getNullValue(DestLTy);
/// C++ [expr.dynamic.cast]p9:
/// A failed cast to reference type throws std::bad_cast
return llvm::UndefValue::get(DestLTy);
llvm::Value *CodeGenFunction::EmitDynamicCast(llvm::Value *Value,
const CXXDynamicCastExpr *DCE) {
QualType DestTy = DCE->getTypeAsWritten();
if (DCE->isAlwaysNull())
return EmitDynamicCastToNull(*this, DestTy);
QualType SrcTy = DCE->getSubExpr()->getType();
// C++ [expr.dynamic.cast]p4:
// If the value of v is a null pointer value in the pointer case, the result
// is the null pointer value of type T.
bool ShouldNullCheckSrcValue = SrcTy->isPointerType();
llvm::BasicBlock *CastNull = 0;
llvm::BasicBlock *CastNotNull = 0;
llvm::BasicBlock *CastEnd = createBasicBlock("dynamic_cast.end");
if (ShouldNullCheckSrcValue) {
CastNull = createBasicBlock("dynamic_cast.null");
CastNotNull = createBasicBlock("dynamic_cast.notnull");
llvm::Value *IsNull = Builder.CreateIsNull(Value);
Builder.CreateCondBr(IsNull, CastNull, CastNotNull);
Value = EmitDynamicCastCall(*this, Value, SrcTy, DestTy, CastEnd);
if (ShouldNullCheckSrcValue) {
if (ShouldNullCheckSrcValue) {
llvm::PHINode *PHI = Builder.CreatePHI(Value->getType(), 2);
PHI->addIncoming(Value, CastNotNull);
PHI->addIncoming(llvm::Constant::getNullValue(Value->getType()), CastNull);
Value = PHI;
return Value;
void CodeGenFunction::EmitLambdaExpr(const LambdaExpr *E, AggValueSlot Slot) {
RunCleanupsScope Scope(*this);
LValue SlotLV = MakeAddrLValue(Slot.getAddr(), E->getType(),
CXXRecordDecl::field_iterator CurField = E->getLambdaClass()->field_begin();
for (LambdaExpr::capture_init_iterator i = E->capture_init_begin(),
e = E->capture_init_end();
i != e; ++i, ++CurField) {
// Emit initialization
LValue LV = EmitLValueForFieldInitialization(SlotLV, *CurField);
ArrayRef<VarDecl *> ArrayIndexes;
if (CurField->getType()->isArrayType())
ArrayIndexes = E->getCaptureInitIndexVars(i);
EmitInitializerForField(*CurField, LV, *i, ArrayIndexes);