Files
clang-p2996/clang/lib/CodeGen/CGExprCXX.cpp
John McCall 7f9c92a9a0 When emitting a new-expression inside a conditional expression,
the cleanup might not be dominated by the allocation code.
In this case, we have to store aside all the delete arguments
in case we need them later.  There's room for optimization here
in cases where we end up not actually needing the cleanup in
different branches (or being able to pop it after the
initialization code).

Also make sure we only call this operator delete along the path
where we actually allocated something.

Fixes rdar://problem/8439196.

llvm-svn: 114145
2010-09-17 00:50:28 +00:00

1490 lines
55 KiB
C++

//===--- 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 "CGCXXABI.h"
#include "CGObjCRuntime.h"
#include "llvm/Intrinsics.h"
using namespace clang;
using namespace CodeGen;
RValue CodeGenFunction::EmitCXXMemberCall(const CXXMethodDecl *MD,
llvm::Value *Callee,
ReturnValueSlot ReturnValue,
llvm::Value *This,
llvm::Value *VTT,
CallExpr::const_arg_iterator ArgBeg,
CallExpr::const_arg_iterator ArgEnd) {
assert(MD->isInstance() &&
"Trying to emit a member call expr on a static method!");
const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();
CallArgList Args;
// Push the this ptr.
Args.push_back(std::make_pair(RValue::get(This),
MD->getThisType(getContext())));
// If there is a VTT parameter, emit it.
if (VTT) {
QualType T = getContext().getPointerType(getContext().VoidPtrTy);
Args.push_back(std::make_pair(RValue::get(VTT), T));
}
// And the rest of the call args
EmitCallArgs(Args, FPT, ArgBeg, ArgEnd);
QualType ResultType = FPT->getResultType();
return EmitCall(CGM.getTypes().getFunctionInfo(ResultType, Args,
FPT->getExtInfo()),
Callee, ReturnValue, Args, MD);
}
/// canDevirtualizeMemberFunctionCalls - Checks whether virtual calls on given
/// expr can be devirtualized.
static bool canDevirtualizeMemberFunctionCalls(const Expr *Base) {
if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base)) {
if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) {
// This is a record decl. We know the type and can devirtualize it.
return VD->getType()->isRecordType();
}
return false;
}
// We can always devirtualize calls on temporary object expressions.
if (isa<CXXConstructExpr>(Base))
return true;
// And calls on bound temporaries.
if (isa<CXXBindTemporaryExpr>(Base))
return true;
// Check if this is a call expr that returns a record type.
if (const CallExpr *CE = dyn_cast<CallExpr>(Base))
return CE->getCallReturnType()->isRecordType();
// We can't devirtualize the call.
return false;
}
RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE,
ReturnValueSlot ReturnValue) {
if (isa<BinaryOperator>(CE->getCallee()->IgnoreParens()))
return EmitCXXMemberPointerCallExpr(CE, ReturnValue);
const MemberExpr *ME = cast<MemberExpr>(CE->getCallee()->IgnoreParens());
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,
ReturnValue, CE->arg_begin(), CE->arg_end());
}
// Compute the object pointer.
llvm::Value *This;
if (ME->isArrow())
This = EmitScalarExpr(ME->getBase());
else {
LValue BaseLV = EmitLValue(ME->getBase());
if (BaseLV.isPropertyRef() || BaseLV.isKVCRef()) {
QualType QT = ME->getBase()->getType();
RValue RV =
BaseLV.isPropertyRef() ? EmitLoadOfPropertyRefLValue(BaseLV, QT)
: EmitLoadOfKVCRefLValue(BaseLV, QT);
This = RV.isScalar() ? RV.getScalarVal() : RV.getAggregateAddr();
}
else
This = BaseLV.getAddress();
}
if (MD->isTrivial()) {
if (isa<CXXDestructorDecl>(MD)) return RValue::get(0);
assert(MD->isCopyAssignment() && "unknown trivial member function");
// We don't like to generate the trivial copy assignment operator when
// it isn't necessary; just produce the proper effect here.
llvm::Value *RHS = EmitLValue(*CE->arg_begin()).getAddress();
EmitAggregateCopy(This, RHS, CE->getType());
return RValue::get(This);
}
// Compute the function type we're calling.
const CGFunctionInfo &FInfo =
(isa<CXXDestructorDecl>(MD)
? CGM.getTypes().getFunctionInfo(cast<CXXDestructorDecl>(MD),
Dtor_Complete)
: CGM.getTypes().getFunctionInfo(MD));
const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();
const llvm::Type *Ty
= CGM.getTypes().GetFunctionType(FInfo, FPT->isVariadic());
// 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 = MD->isVirtual() && !ME->hasQualifier()
&& !canDevirtualizeMemberFunctionCalls(ME->getBase());
llvm::Value *Callee;
if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(MD)) {
if (UseVirtualCall) {
Callee = BuildVirtualCall(Dtor, Dtor_Complete, This, Ty);
} else {
Callee = CGM.GetAddrOfFunction(GlobalDecl(Dtor, Dtor_Complete), Ty);
}
} else if (UseVirtualCall) {
Callee = BuildVirtualCall(MD, This, Ty);
} else {
Callee = CGM.GetAddrOfFunction(MD, Ty);
}
return EmitCXXMemberCall(MD, Callee, ReturnValue, This, /*VTT=*/0,
CE->arg_begin(), CE->arg_end());
}
RValue
CodeGenFunction::EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E,
ReturnValueSlot ReturnValue) {
const BinaryOperator *BO =
cast<BinaryOperator>(E->getCallee()->IgnoreParens());
const Expr *BaseExpr = BO->getLHS();
const Expr *MemFnExpr = BO->getRHS();
const MemberPointerType *MPT =
MemFnExpr->getType()->getAs<MemberPointerType>();
const FunctionProtoType *FPT =
MPT->getPointeeType()->getAs<FunctionProtoType>();
const CXXRecordDecl *RD =
cast<CXXRecordDecl>(MPT->getClass()->getAs<RecordType>()->getDecl());
// 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);
else
This = EmitLValue(BaseExpr).getAddress();
// Ask the ABI to load the callee. Note that This is modified.
llvm::Value *Callee =
CGM.getCXXABI().EmitLoadOfMemberFunctionPointer(CGF, This, MemFnPtr, MPT);
CallArgList Args;
QualType ThisType =
getContext().getPointerType(getContext().getTagDeclType(RD));
// Push the this ptr.
Args.push_back(std::make_pair(RValue::get(This), ThisType));
// And the rest of the call args
EmitCallArgs(Args, FPT, E->arg_begin(), E->arg_end());
const FunctionType *BO_FPT = BO->getType()->getAs<FunctionProtoType>();
return EmitCall(CGM.getTypes().getFunctionInfo(Args, BO_FPT), Callee,
ReturnValue, Args);
}
RValue
CodeGenFunction::EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E,
const CXXMethodDecl *MD,
ReturnValueSlot ReturnValue) {
assert(MD->isInstance() &&
"Trying to emit a member call expr on a static method!");
if (MD->isCopyAssignment()) {
const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(MD->getDeclContext());
if (ClassDecl->hasTrivialCopyAssignment()) {
assert(!ClassDecl->hasUserDeclaredCopyAssignment() &&
"EmitCXXOperatorMemberCallExpr - user declared copy assignment");
LValue LV = EmitLValue(E->getArg(0));
llvm::Value *This;
if (LV.isPropertyRef() || LV.isKVCRef()) {
AggValueSlot Slot = CreateAggTemp(E->getArg(1)->getType());
EmitAggExpr(E->getArg(1), Slot);
if (LV.isPropertyRef())
EmitObjCPropertySet(LV.getPropertyRefExpr(), Slot.asRValue());
else
EmitObjCPropertySet(LV.getKVCRefExpr(), Slot.asRValue());
return RValue::getAggregate(0, false);
}
else
This = LV.getAddress();
llvm::Value *Src = EmitLValue(E->getArg(1)).getAddress();
QualType Ty = E->getType();
EmitAggregateCopy(This, Src, Ty);
return RValue::get(This);
}
}
const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();
const llvm::Type *Ty =
CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(MD),
FPT->isVariadic());
LValue LV = EmitLValue(E->getArg(0));
llvm::Value *This;
if (LV.isPropertyRef() || LV.isKVCRef()) {
QualType QT = E->getArg(0)->getType();
RValue RV =
LV.isPropertyRef() ? EmitLoadOfPropertyRefLValue(LV, QT)
: EmitLoadOfKVCRefLValue(LV, QT);
assert (!RV.isScalar() && "EmitCXXOperatorMemberCallExpr");
This = RV.getAggregateAddr();
}
else
This = LV.getAddress();
llvm::Value *Callee;
if (MD->isVirtual() && !canDevirtualizeMemberFunctionCalls(E->getArg(0)))
Callee = BuildVirtualCall(MD, This, Ty);
else
Callee = CGM.GetAddrOfFunction(MD, Ty);
return EmitCXXMemberCall(MD, Callee, ReturnValue, This, /*VTT=*/0,
E->arg_begin() + 1, E->arg_end());
}
void
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.
if (E->requiresZeroInitialization())
EmitNullInitialization(Dest.getAddr(), E->getType());
// If this is a call to a trivial default constructor, do nothing.
if (CD->isTrivial() && CD->isDefaultConstructor())
return;
// Code gen optimization to eliminate copy constructor and return
// its first argument instead, if in fact that argument is a temporary
// object.
if (getContext().getLangOptions().ElideConstructors && E->isElidable()) {
if (E->getArg(0)->isTemporaryObject(getContext(), CD->getParent())) {
EmitAggExpr(E->getArg(0), Dest);
return;
}
}
const ConstantArrayType *Array
= getContext().getAsConstantArrayType(E->getType());
if (Array) {
QualType BaseElementTy = getContext().getBaseElementType(Array);
const llvm::Type *BasePtr = ConvertType(BaseElementTy);
BasePtr = llvm::PointerType::getUnqual(BasePtr);
llvm::Value *BaseAddrPtr =
Builder.CreateBitCast(Dest.getAddr(), BasePtr);
EmitCXXAggrConstructorCall(CD, Array, BaseAddrPtr,
E->arg_begin(), E->arg_end());
}
else {
CXXCtorType Type =
(E->getConstructionKind() == CXXConstructExpr::CK_Complete)
? Ctor_Complete : Ctor_Base;
bool ForVirtualBase =
E->getConstructionKind() == CXXConstructExpr::CK_VirtualBase;
// Call the constructor.
EmitCXXConstructorCall(CD, Type, ForVirtualBase, Dest.getAddr(),
E->arg_begin(), E->arg_end());
}
}
/// Check whether the given operator new[] is the global placement
/// operator new[].
static bool IsPlacementOperatorNewArray(ASTContext &Ctx,
const FunctionDecl *Fn) {
// Must be in global scope. Note that allocation functions can't be
// declared in namespaces.
if (!Fn->getDeclContext()->getRedeclContext()->isFileContext())
return false;
// Signature must be void *operator new[](size_t, void*).
// The size_t is common to all operator new[]s.
if (Fn->getNumParams() != 2)
return false;
CanQualType ParamType = Ctx.getCanonicalType(Fn->getParamDecl(1)->getType());
return (ParamType == Ctx.VoidPtrTy);
}
static CharUnits CalculateCookiePadding(CodeGenFunction &CGF,
const CXXNewExpr *E) {
if (!E->isArray())
return CharUnits::Zero();
// No cookie is required if the new operator being used is
// ::operator new[](size_t, void*).
const FunctionDecl *OperatorNew = E->getOperatorNew();
if (IsPlacementOperatorNewArray(CGF.getContext(), OperatorNew))
return CharUnits::Zero();
return CGF.CGM.getCXXABI().GetArrayCookieSize(E->getAllocatedType());
}
static llvm::Value *EmitCXXNewAllocSize(ASTContext &Context,
CodeGenFunction &CGF,
const CXXNewExpr *E,
llvm::Value *&NumElements,
llvm::Value *&SizeWithoutCookie) {
QualType ElemType = E->getAllocatedType();
const llvm::IntegerType *SizeTy =
cast<llvm::IntegerType>(CGF.ConvertType(CGF.getContext().getSizeType()));
CharUnits TypeSize = CGF.getContext().getTypeSizeInChars(ElemType);
if (!E->isArray()) {
SizeWithoutCookie = llvm::ConstantInt::get(SizeTy, TypeSize.getQuantity());
return SizeWithoutCookie;
}
// Figure out the cookie size.
CharUnits CookieSize = CalculateCookiePadding(CGF, E);
// 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());
assert(NumElements->getType() == SizeTy && "element count not a size_t");
uint64_t ArraySizeMultiplier = 1;
while (const ConstantArrayType *CAT
= CGF.getContext().getAsConstantArrayType(ElemType)) {
ElemType = CAT->getElementType();
ArraySizeMultiplier *= CAT->getSize().getZExtValue();
}
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)) {
llvm::APInt NEC = NumElementsC->getValue();
unsigned SizeWidth = NEC.getBitWidth();
// Determine if there is an overflow here by doing an extended multiply.
NEC.zext(SizeWidth*2);
llvm::APInt SC(SizeWidth*2, TypeSize.getQuantity());
SC *= NEC;
if (!CookieSize.isZero()) {
// Save the current size without a cookie. We don't care if an
// overflow's already happened because SizeWithoutCookie isn't
// used if the allocator returns null or throws, as it should
// always do on an overflow.
llvm::APInt SWC = SC;
SWC.trunc(SizeWidth);
SizeWithoutCookie = llvm::ConstantInt::get(SizeTy, SWC);
// Add the cookie size.
SC += llvm::APInt(SizeWidth*2, CookieSize.getQuantity());
}
if (SC.countLeadingZeros() >= SizeWidth) {
SC.trunc(SizeWidth);
Size = llvm::ConstantInt::get(SizeTy, SC);
} else {
// On overflow, produce a -1 so operator new throws.
Size = llvm::Constant::getAllOnesValue(SizeTy);
}
// Scale NumElements while we're at it.
uint64_t N = NEC.getZExtValue() * ArraySizeMultiplier;
NumElements = llvm::ConstantInt::get(SizeTy, N);
// Otherwise, we don't need to do an overflow-checked multiplication if
// we're multiplying by one.
} else if (TypeSize.isOne()) {
assert(ArraySizeMultiplier == 1);
Size = NumElements;
// If we need a cookie, add its size in with an overflow check.
// This is maybe a little paranoid.
if (!CookieSize.isZero()) {
SizeWithoutCookie = Size;
llvm::Value *CookieSizeV
= llvm::ConstantInt::get(SizeTy, CookieSize.getQuantity());
const llvm::Type *Types[] = { SizeTy };
llvm::Value *UAddF
= CGF.CGM.getIntrinsic(llvm::Intrinsic::uadd_with_overflow, Types, 1);
llvm::Value *AddRes
= CGF.Builder.CreateCall2(UAddF, Size, CookieSizeV);
Size = CGF.Builder.CreateExtractValue(AddRes, 0);
llvm::Value *DidOverflow = CGF.Builder.CreateExtractValue(AddRes, 1);
Size = CGF.Builder.CreateSelect(DidOverflow,
llvm::ConstantInt::get(SizeTy, -1),
Size);
}
// Otherwise use the int.umul.with.overflow intrinsic.
} else {
llvm::Value *OutermostElementSize
= llvm::ConstantInt::get(SizeTy, TypeSize.getQuantity());
llvm::Value *NumOutermostElements = NumElements;
// Scale NumElements by the array size multiplier. This might
// overflow, but only if the multiplication below also overflows,
// in which case this multiplication isn't used.
if (ArraySizeMultiplier != 1)
NumElements = CGF.Builder.CreateMul(NumElements,
llvm::ConstantInt::get(SizeTy, ArraySizeMultiplier));
// The requested size of the outermost array is non-constant.
// Multiply that by the static size of the elements of that array;
// on unsigned overflow, set the size to -1 to trigger an
// exception from the allocation routine. This is sufficient to
// prevent buffer overruns from the allocator returning a
// seemingly valid pointer to insufficient space. This idea comes
// originally from MSVC, and GCC has an open bug requesting
// similar behavior:
// http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19351
//
// This will not be sufficient for C++0x, which requires a
// specific exception class (std::bad_array_new_length).
// That will require ABI support that has not yet been specified.
const llvm::Type *Types[] = { SizeTy };
llvm::Value *UMulF
= CGF.CGM.getIntrinsic(llvm::Intrinsic::umul_with_overflow, Types, 1);
llvm::Value *MulRes = CGF.Builder.CreateCall2(UMulF, NumOutermostElements,
OutermostElementSize);
// The overflow bit.
llvm::Value *DidOverflow = CGF.Builder.CreateExtractValue(MulRes, 1);
// The result of the multiplication.
Size = CGF.Builder.CreateExtractValue(MulRes, 0);
// If we have a cookie, we need to add that size in, too.
if (!CookieSize.isZero()) {
SizeWithoutCookie = Size;
llvm::Value *CookieSizeV
= llvm::ConstantInt::get(SizeTy, CookieSize.getQuantity());
llvm::Value *UAddF
= CGF.CGM.getIntrinsic(llvm::Intrinsic::uadd_with_overflow, Types, 1);
llvm::Value *AddRes
= CGF.Builder.CreateCall2(UAddF, SizeWithoutCookie, CookieSizeV);
Size = CGF.Builder.CreateExtractValue(AddRes, 0);
llvm::Value *AddDidOverflow = CGF.Builder.CreateExtractValue(AddRes, 1);
DidOverflow = CGF.Builder.CreateAnd(DidOverflow, AddDidOverflow);
}
Size = CGF.Builder.CreateSelect(DidOverflow,
llvm::ConstantInt::get(SizeTy, -1),
Size);
}
if (CookieSize.isZero())
SizeWithoutCookie = Size;
else
assert(SizeWithoutCookie && "didn't set SizeWithoutCookie?");
return Size;
}
static void StoreAnyExprIntoOneUnit(CodeGenFunction &CGF, const CXXNewExpr *E,
llvm::Value *NewPtr) {
assert(E->getNumConstructorArgs() == 1 &&
"Can only have one argument to initializer of POD type.");
const Expr *Init = E->getConstructorArg(0);
QualType AllocType = E->getAllocatedType();
unsigned Alignment =
CGF.getContext().getTypeAlignInChars(AllocType).getQuantity();
if (!CGF.hasAggregateLLVMType(AllocType))
CGF.EmitStoreOfScalar(CGF.EmitScalarExpr(Init), NewPtr,
AllocType.isVolatileQualified(), Alignment,
AllocType);
else if (AllocType->isAnyComplexType())
CGF.EmitComplexExprIntoAddr(Init, NewPtr,
AllocType.isVolatileQualified());
else {
AggValueSlot Slot
= AggValueSlot::forAddr(NewPtr, AllocType.isVolatileQualified(), true);
CGF.EmitAggExpr(Init, Slot);
}
}
void
CodeGenFunction::EmitNewArrayInitializer(const CXXNewExpr *E,
llvm::Value *NewPtr,
llvm::Value *NumElements) {
// We have a POD type.
if (E->getNumConstructorArgs() == 0)
return;
const llvm::Type *SizeTy = ConvertType(getContext().getSizeType());
// Create a temporary for the loop index and initialize it with 0.
llvm::Value *IndexPtr = CreateTempAlloca(SizeTy, "loop.index");
llvm::Value *Zero = llvm::Constant::getNullValue(SizeTy);
Builder.CreateStore(Zero, IndexPtr);
// Start the loop with a block that tests the condition.
llvm::BasicBlock *CondBlock = createBasicBlock("for.cond");
llvm::BasicBlock *AfterFor = createBasicBlock("for.end");
EmitBlock(CondBlock);
llvm::BasicBlock *ForBody = createBasicBlock("for.body");
// Generate: if (loop-index < number-of-elements fall to the loop body,
// otherwise, go to the block after the for-loop.
llvm::Value *Counter = Builder.CreateLoad(IndexPtr);
llvm::Value *IsLess = Builder.CreateICmpULT(Counter, NumElements, "isless");
// If the condition is true, execute the body.
Builder.CreateCondBr(IsLess, ForBody, AfterFor);
EmitBlock(ForBody);
llvm::BasicBlock *ContinueBlock = createBasicBlock("for.inc");
// Inside the loop body, emit the constructor call on the array element.
Counter = Builder.CreateLoad(IndexPtr);
llvm::Value *Address = Builder.CreateInBoundsGEP(NewPtr, Counter,
"arrayidx");
StoreAnyExprIntoOneUnit(*this, E, Address);
EmitBlock(ContinueBlock);
// Emit the increment of the loop counter.
llvm::Value *NextVal = llvm::ConstantInt::get(SizeTy, 1);
Counter = Builder.CreateLoad(IndexPtr);
NextVal = Builder.CreateAdd(Counter, NextVal, "inc");
Builder.CreateStore(NextVal, IndexPtr);
// Finally, branch back up to the condition for the next iteration.
EmitBranch(CondBlock);
// Emit the fall-through block.
EmitBlock(AfterFor, true);
}
static void EmitZeroMemSet(CodeGenFunction &CGF, QualType T,
llvm::Value *NewPtr, llvm::Value *Size) {
llvm::LLVMContext &VMContext = CGF.CGM.getLLVMContext();
const llvm::Type *BP = llvm::Type::getInt8PtrTy(VMContext);
if (NewPtr->getType() != BP)
NewPtr = CGF.Builder.CreateBitCast(NewPtr, BP, "tmp");
CGF.Builder.CreateCall5(CGF.CGM.getMemSetFn(BP, CGF.IntPtrTy), NewPtr,
llvm::Constant::getNullValue(llvm::Type::getInt8Ty(VMContext)),
Size,
llvm::ConstantInt::get(CGF.Int32Ty,
CGF.getContext().getTypeAlign(T)/8),
llvm::ConstantInt::get(llvm::Type::getInt1Ty(VMContext),
0));
}
static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E,
llvm::Value *NewPtr,
llvm::Value *NumElements,
llvm::Value *AllocSizeWithoutCookie) {
if (E->isArray()) {
if (CXXConstructorDecl *Ctor = E->getConstructor()) {
bool RequiresZeroInitialization = false;
if (Ctor->getParent()->hasTrivialConstructor()) {
// If new expression did not specify value-initialization, then there
// is no initialization.
if (!E->hasInitializer() || Ctor->getParent()->isEmpty())
return;
if (CGF.CGM.getTypes().isZeroInitializable(E->getAllocatedType())) {
// Optimization: since zero initialization will just set the memory
// to all zeroes, generate a single memset to do it in one shot.
EmitZeroMemSet(CGF, E->getAllocatedType(), NewPtr,
AllocSizeWithoutCookie);
return;
}
RequiresZeroInitialization = true;
}
CGF.EmitCXXAggrConstructorCall(Ctor, NumElements, NewPtr,
E->constructor_arg_begin(),
E->constructor_arg_end(),
RequiresZeroInitialization);
return;
} else if (E->getNumConstructorArgs() == 1 &&
isa<ImplicitValueInitExpr>(E->getConstructorArg(0))) {
// Optimization: since zero initialization will just set the memory
// to all zeroes, generate a single memset to do it in one shot.
EmitZeroMemSet(CGF, E->getAllocatedType(), NewPtr,
AllocSizeWithoutCookie);
return;
} else {
CGF.EmitNewArrayInitializer(E, NewPtr, NumElements);
return;
}
}
if (CXXConstructorDecl *Ctor = E->getConstructor()) {
// Per C++ [expr.new]p15, if we have an initializer, then we're performing
// direct initialization. C++ [dcl.init]p5 requires that we
// zero-initialize storage if there are no user-declared constructors.
if (E->hasInitializer() &&
!Ctor->getParent()->hasUserDeclaredConstructor() &&
!Ctor->getParent()->isEmpty())
CGF.EmitNullInitialization(NewPtr, E->getAllocatedType());
CGF.EmitCXXConstructorCall(Ctor, Ctor_Complete, /*ForVirtualBase=*/false,
NewPtr, E->constructor_arg_begin(),
E->constructor_arg_end());
return;
}
// We have a POD type.
if (E->getNumConstructorArgs() == 0)
return;
StoreAnyExprIntoOneUnit(CGF, E, NewPtr);
}
/// A utility class for saving an rvalue.
class SavedRValue {
public:
enum Kind { ScalarLiteral, ScalarAddress,
AggregateLiteral, AggregateAddress,
Complex };
private:
llvm::Value *Value;
Kind K;
SavedRValue(llvm::Value *V, Kind K) : Value(V), K(K) {}
public:
SavedRValue() {}
static SavedRValue forScalarLiteral(llvm::Value *V) {
return SavedRValue(V, ScalarLiteral);
}
static SavedRValue forScalarAddress(llvm::Value *Addr) {
return SavedRValue(Addr, ScalarAddress);
}
static SavedRValue forAggregateLiteral(llvm::Value *V) {
return SavedRValue(V, AggregateLiteral);
}
static SavedRValue forAggregateAddress(llvm::Value *Addr) {
return SavedRValue(Addr, AggregateAddress);
}
static SavedRValue forComplexAddress(llvm::Value *Addr) {
return SavedRValue(Addr, Complex);
}
Kind getKind() const { return K; }
llvm::Value *getValue() const { return Value; }
};
/// Given an r-value, perform the code necessary to make sure that a
/// future RestoreRValue will be able to load the value without
/// domination concerns.
static SavedRValue SaveRValue(CodeGenFunction &CGF, RValue RV) {
if (RV.isScalar()) {
llvm::Value *V = RV.getScalarVal();
// These automatically dominate and don't need to be saved.
if (isa<llvm::Constant>(V) || isa<llvm::AllocaInst>(V))
return SavedRValue::forScalarLiteral(V);
// Everything else needs an alloca.
llvm::Value *Addr = CGF.CreateTempAlloca(V->getType(), "saved-rvalue");
CGF.Builder.CreateStore(V, Addr);
return SavedRValue::forScalarAddress(Addr);
}
if (RV.isComplex()) {
CodeGenFunction::ComplexPairTy V = RV.getComplexVal();
const llvm::Type *ComplexTy =
llvm::StructType::get(CGF.getLLVMContext(),
V.first->getType(), V.second->getType(),
(void*) 0);
llvm::Value *Addr = CGF.CreateTempAlloca(ComplexTy, "saved-complex");
CGF.StoreComplexToAddr(V, Addr, /*volatile*/ false);
return SavedRValue::forComplexAddress(Addr);
}
assert(RV.isAggregate());
llvm::Value *V = RV.getAggregateAddr(); // TODO: volatile?
if (isa<llvm::Constant>(V) || isa<llvm::AllocaInst>(V))
return SavedRValue::forAggregateLiteral(V);
llvm::Value *Addr = CGF.CreateTempAlloca(V->getType(), "saved-rvalue");
CGF.Builder.CreateStore(V, Addr);
return SavedRValue::forAggregateAddress(Addr);
}
/// Given a saved r-value produced by SaveRValue, perform the code
/// necessary to restore it to usability at the current insertion
/// point.
static RValue RestoreRValue(CodeGenFunction &CGF, SavedRValue RV) {
switch (RV.getKind()) {
case SavedRValue::ScalarLiteral:
return RValue::get(RV.getValue());
case SavedRValue::ScalarAddress:
return RValue::get(CGF.Builder.CreateLoad(RV.getValue()));
case SavedRValue::AggregateLiteral:
return RValue::getAggregate(RV.getValue());
case SavedRValue::AggregateAddress:
return RValue::getAggregate(CGF.Builder.CreateLoad(RV.getValue()));
case SavedRValue::Complex:
return RValue::getComplex(CGF.LoadComplexFromAddr(RV.getValue(), false));
}
llvm_unreachable("bad saved r-value kind");
return RValue();
}
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); }
public:
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, bool IsForEH) {
const FunctionProtoType *FPT
= OperatorDelete->getType()->getAs<FunctionProtoType>();
assert(FPT->getNumArgs() == NumPlacementArgs + 1 ||
(FPT->getNumArgs() == 2 && NumPlacementArgs == 0));
CallArgList DeleteArgs;
// The first argument is always a void*.
FunctionProtoType::arg_type_iterator AI = FPT->arg_type_begin();
DeleteArgs.push_back(std::make_pair(RValue::get(Ptr), *AI++));
// A member 'operator delete' can take an extra 'size_t' argument.
if (FPT->getNumArgs() == NumPlacementArgs + 2)
DeleteArgs.push_back(std::make_pair(RValue::get(AllocSize), *AI++));
// Pass the rest of the arguments, which must match exactly.
for (unsigned I = 0; I != NumPlacementArgs; ++I)
DeleteArgs.push_back(std::make_pair(getPlacementArgs()[I], *AI++));
// Call 'operator delete'.
CGF.EmitCall(CGF.CGM.getTypes().getFunctionInfo(DeleteArgs, FPT),
CGF.CGM.GetAddrOfFunction(OperatorDelete),
ReturnValueSlot(), DeleteArgs, OperatorDelete);
}
};
/// 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;
SavedRValue Ptr;
SavedRValue AllocSize;
SavedRValue *getPlacementArgs() {
return reinterpret_cast<SavedRValue*>(this+1);
}
public:
static size_t getExtraSize(size_t NumPlacementArgs) {
return NumPlacementArgs * sizeof(SavedRValue);
}
CallDeleteDuringConditionalNew(size_t NumPlacementArgs,
const FunctionDecl *OperatorDelete,
SavedRValue Ptr,
SavedRValue AllocSize)
: NumPlacementArgs(NumPlacementArgs), OperatorDelete(OperatorDelete),
Ptr(Ptr), AllocSize(AllocSize) {}
void setPlacementArg(unsigned I, SavedRValue Arg) {
assert(I < NumPlacementArgs && "index out of range");
getPlacementArgs()[I] = Arg;
}
void Emit(CodeGenFunction &CGF, bool IsForEH) {
const FunctionProtoType *FPT
= OperatorDelete->getType()->getAs<FunctionProtoType>();
assert(FPT->getNumArgs() == NumPlacementArgs + 1 ||
(FPT->getNumArgs() == 2 && NumPlacementArgs == 0));
CallArgList DeleteArgs;
// The first argument is always a void*.
FunctionProtoType::arg_type_iterator AI = FPT->arg_type_begin();
DeleteArgs.push_back(std::make_pair(RestoreRValue(CGF, Ptr), *AI++));
// A member 'operator delete' can take an extra 'size_t' argument.
if (FPT->getNumArgs() == NumPlacementArgs + 2) {
RValue RV = RestoreRValue(CGF, AllocSize);
DeleteArgs.push_back(std::make_pair(RV, *AI++));
}
// Pass the rest of the arguments, which must match exactly.
for (unsigned I = 0; I != NumPlacementArgs; ++I) {
RValue RV = RestoreRValue(CGF, getPlacementArgs()[I]);
DeleteArgs.push_back(std::make_pair(RV, *AI++));
}
// Call 'operator delete'.
CGF.EmitCall(CGF.CGM.getTypes().getFunctionInfo(DeleteArgs, FPT),
CGF.CGM.GetAddrOfFunction(OperatorDelete),
ReturnValueSlot(), DeleteArgs, OperatorDelete);
}
};
}
/// 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
.pushCleanupWithExtra<CallDeleteDuringNew>(EHCleanup,
E->getNumPlacementArgs(),
E->getOperatorDelete(),
NewPtr, AllocSize);
for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I)
Cleanup->setPlacementArg(I, NewArgs[I+1].first);
return;
}
// Otherwise, we need to save all this stuff.
SavedRValue SavedNewPtr = SaveRValue(CGF, RValue::get(NewPtr));
SavedRValue SavedAllocSize = SaveRValue(CGF, RValue::get(AllocSize));
CallDeleteDuringConditionalNew *Cleanup = CGF.EHStack
.pushCleanupWithExtra<CallDeleteDuringConditionalNew>(InactiveEHCleanup,
E->getNumPlacementArgs(),
E->getOperatorDelete(),
SavedNewPtr,
SavedAllocSize);
for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I)
Cleanup->setPlacementArg(I, SaveRValue(CGF, NewArgs[I+1].first));
CGF.ActivateCleanupBlock(CGF.EHStack.stable_begin());
}
llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
QualType AllocType = E->getAllocatedType();
if (AllocType->isArrayType())
while (const ArrayType *AType = getContext().getAsArrayType(AllocType))
AllocType = AType->getElementType();
FunctionDecl *NewFD = E->getOperatorNew();
const FunctionProtoType *NewFTy = NewFD->getType()->getAs<FunctionProtoType>();
CallArgList NewArgs;
// The allocation size is the first argument.
QualType SizeTy = getContext().getSizeType();
llvm::Value *NumElements = 0;
llvm::Value *AllocSizeWithoutCookie = 0;
llvm::Value *AllocSize = EmitCXXNewAllocSize(getContext(),
*this, E, NumElements,
AllocSizeWithoutCookie);
NewArgs.push_back(std::make_pair(RValue::get(AllocSize), SizeTy));
// Emit the rest of the arguments.
// FIXME: Ideally, this should just use EmitCallArgs.
CXXNewExpr::const_arg_iterator NewArg = E->placement_arg_begin();
// First, use the types from the function type.
// We start at 1 here because the first argument (the allocation size)
// has already been emitted.
for (unsigned i = 1, e = NewFTy->getNumArgs(); i != e; ++i, ++NewArg) {
QualType ArgType = NewFTy->getArgType(i);
assert(getContext().getCanonicalType(ArgType.getNonReferenceType()).
getTypePtr() ==
getContext().getCanonicalType(NewArg->getType()).getTypePtr() &&
"type mismatch in call argument!");
NewArgs.push_back(std::make_pair(EmitCallArg(*NewArg, ArgType),
ArgType));
}
// Either we've emitted all the call args, or we have a call to a
// variadic function.
assert((NewArg == E->placement_arg_end() || NewFTy->isVariadic()) &&
"Extra arguments in non-variadic function!");
// If we still have any arguments, emit them using the type of the argument.
for (CXXNewExpr::const_arg_iterator NewArgEnd = E->placement_arg_end();
NewArg != NewArgEnd; ++NewArg) {
QualType ArgType = NewArg->getType();
NewArgs.push_back(std::make_pair(EmitCallArg(*NewArg, ArgType),
ArgType));
}
// Emit the call to new.
RValue RV =
EmitCall(CGM.getTypes().getFunctionInfo(NewArgs, NewFTy),
CGM.GetAddrOfFunction(NewFD), ReturnValueSlot(), NewArgs, NewFD);
// If an allocation function is declared with an empty exception specification
// it returns null to indicate failure to allocate storage. [expr.new]p13.
// (We don't need to check for null when there's no new initializer and
// we're allocating a POD type).
bool NullCheckResult = NewFTy->hasEmptyExceptionSpec() &&
!(AllocType->isPODType() && !E->hasInitializer());
llvm::BasicBlock *NullCheckSource = 0;
llvm::BasicBlock *NewNotNull = 0;
llvm::BasicBlock *NewEnd = 0;
llvm::Value *NewPtr = RV.getScalarVal();
unsigned AS = cast<llvm::PointerType>(NewPtr->getType())->getAddressSpace();
if (NullCheckResult) {
NullCheckSource = Builder.GetInsertBlock();
NewNotNull = createBasicBlock("new.notnull");
NewEnd = createBasicBlock("new.end");
llvm::Value *IsNull = Builder.CreateIsNull(NewPtr, "new.isnull");
Builder.CreateCondBr(IsNull, NewEnd, NewNotNull);
EmitBlock(NewNotNull);
}
assert((AllocSize == AllocSizeWithoutCookie) ==
CalculateCookiePadding(*this, E).isZero());
if (AllocSize != AllocSizeWithoutCookie) {
assert(E->isArray());
NewPtr = CGM.getCXXABI().InitializeArrayCookie(CGF, NewPtr, NumElements,
AllocType);
}
// If there's an operator delete, enter a cleanup to call it if an
// exception is thrown.
EHScopeStack::stable_iterator CallOperatorDelete;
if (E->getOperatorDelete()) {
EnterNewDeleteCleanup(*this, E, NewPtr, AllocSize, NewArgs);
CallOperatorDelete = EHStack.stable_begin();
}
const llvm::Type *ElementPtrTy
= ConvertTypeForMem(AllocType)->getPointerTo(AS);
NewPtr = Builder.CreateBitCast(NewPtr, ElementPtrTy);
if (E->isArray()) {
EmitNewInitializer(*this, E, NewPtr, NumElements, AllocSizeWithoutCookie);
// 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.
const llvm::Type *ResultTy = ConvertTypeForMem(E->getType());
if (NewPtr->getType() != ResultTy)
NewPtr = Builder.CreateBitCast(NewPtr, ResultTy);
} else {
EmitNewInitializer(*this, E, NewPtr, NumElements, AllocSizeWithoutCookie);
}
// Deactivate the 'operator delete' cleanup if we finished
// initialization.
if (CallOperatorDelete.isValid())
DeactivateCleanupBlock(CallOperatorDelete);
if (NullCheckResult) {
Builder.CreateBr(NewEnd);
llvm::BasicBlock *NotNullSource = Builder.GetInsertBlock();
EmitBlock(NewEnd);
llvm::PHINode *PHI = Builder.CreatePHI(NewPtr->getType());
PHI->reserveOperandSpace(2);
PHI->addIncoming(NewPtr, NotNullSource);
PHI->addIncoming(llvm::Constant::getNullValue(NewPtr->getType()),
NullCheckSource);
NewPtr = PHI;
}
return NewPtr;
}
void CodeGenFunction::EmitDeleteCall(const FunctionDecl *DeleteFD,
llvm::Value *Ptr,
QualType DeleteTy) {
assert(DeleteFD->getOverloadedOperator() == OO_Delete);
const FunctionProtoType *DeleteFTy =
DeleteFD->getType()->getAs<FunctionProtoType>();
CallArgList DeleteArgs;
// Check if we need to pass the size to the delete operator.
llvm::Value *Size = 0;
QualType SizeTy;
if (DeleteFTy->getNumArgs() == 2) {
SizeTy = DeleteFTy->getArgType(1);
CharUnits DeleteTypeSize = getContext().getTypeSizeInChars(DeleteTy);
Size = llvm::ConstantInt::get(ConvertType(SizeTy),
DeleteTypeSize.getQuantity());
}
QualType ArgTy = DeleteFTy->getArgType(0);
llvm::Value *DeletePtr = Builder.CreateBitCast(Ptr, ConvertType(ArgTy));
DeleteArgs.push_back(std::make_pair(RValue::get(DeletePtr), ArgTy));
if (Size)
DeleteArgs.push_back(std::make_pair(RValue::get(Size), SizeTy));
// Emit the call to delete.
EmitCall(CGM.getTypes().getFunctionInfo(DeleteArgs, DeleteFTy),
CGM.GetAddrOfFunction(DeleteFD), ReturnValueSlot(),
DeleteArgs, DeleteFD);
}
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, bool IsForEH) {
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) {
// 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->hasTrivialDestructor()) {
Dtor = RD->getDestructor();
if (Dtor->isVirtual()) {
const llvm::Type *Ty =
CGF.getTypes().GetFunctionType(CGF.getTypes().getFunctionInfo(Dtor,
Dtor_Complete),
/*isVariadic=*/false);
llvm::Value *Callee
= CGF.BuildVirtualCall(Dtor, Dtor_Deleting, Ptr, Ty);
CGF.EmitCXXMemberCall(Dtor, Callee, ReturnValueSlot(), Ptr, /*VTT=*/0,
0, 0);
// The dtor took care of deleting the object.
return;
}
}
}
// Make sure that we call delete even if the dtor throws.
CGF.EHStack.pushCleanup<CallObjectDelete>(NormalAndEHCleanup,
Ptr, OperatorDelete, ElementType);
if (Dtor)
CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete,
/*ForVirtualBase=*/false, Ptr);
CGF.PopCleanupBlock();
}
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, bool IsForEH) {
const FunctionProtoType *DeleteFTy =
OperatorDelete->getType()->getAs<FunctionProtoType>();
assert(DeleteFTy->getNumArgs() == 1 || DeleteFTy->getNumArgs() == 2);
CallArgList Args;
// Pass the pointer as the first argument.
QualType VoidPtrTy = DeleteFTy->getArgType(0);
llvm::Value *DeletePtr
= CGF.Builder.CreateBitCast(Ptr, CGF.ConvertType(VoidPtrTy));
Args.push_back(std::make_pair(RValue::get(DeletePtr), VoidPtrTy));
// Pass the original requested size as the second argument.
if (DeleteFTy->getNumArgs() == 2) {
QualType size_t = DeleteFTy->getArgType(1);
const llvm::IntegerType *SizeTy
= cast<llvm::IntegerType>(CGF.ConvertType(size_t));
CharUnits ElementTypeSize =
CGF.CGM.getContext().getTypeSizeInChars(ElementType);
// 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.push_back(std::make_pair(RValue::get(Size), size_t));
}
// Emit the call to delete.
CGF.EmitCall(CGF.getTypes().getFunctionInfo(Args, DeleteFTy),
CGF.CGM.GetAddrOfFunction(OperatorDelete),
ReturnValueSlot(), Args, OperatorDelete);
}
};
}
/// Emit the code for deleting an array of objects.
static void EmitArrayDelete(CodeGenFunction &CGF,
const FunctionDecl *OperatorDelete,
llvm::Value *Ptr,
QualType ElementType) {
llvm::Value *NumElements = 0;
llvm::Value *AllocatedPtr = 0;
CharUnits CookieSize;
CGF.CGM.getCXXABI().ReadArrayCookie(CGF, Ptr, ElementType,
NumElements, AllocatedPtr, CookieSize);
assert(AllocatedPtr && "ReadArrayCookie didn't set AllocatedPtr");
// Make sure that we call delete even if one of the dtors throws.
CGF.EHStack.pushCleanup<CallArrayDelete>(NormalAndEHCleanup,
AllocatedPtr, OperatorDelete,
NumElements, ElementType,
CookieSize);
if (const CXXRecordDecl *RD = ElementType->getAsCXXRecordDecl()) {
if (!RD->hasTrivialDestructor()) {
assert(NumElements && "ReadArrayCookie didn't find element count"
" for a class with destructor");
CGF.EmitCXXAggrDestructorCall(RD->getDestructor(), NumElements, Ptr);
}
}
CGF.PopCleanupBlock();
}
void CodeGenFunction::EmitCXXDeleteExpr(const CXXDeleteExpr *E) {
// Get at the argument before we performed the implicit conversion
// to void*.
const Expr *Arg = E->getArgument();
while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg)) {
if (ICE->getCastKind() != CK_UserDefinedConversion &&
ICE->getType()->isVoidPointerType())
Arg = ICE->getSubExpr();
else
break;
}
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.CreateICmpEQ(Ptr, llvm::Constant::getNullValue(Ptr->getType()),
"isnull");
Builder.CreateCondBr(IsNull, DeleteEnd, DeleteNotNull);
EmitBlock(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);
llvm::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.
GEP.push_back(Zero);
}
Ptr = Builder.CreateInBoundsGEP(Ptr, GEP.begin(), GEP.end(), "del.first");
}
assert(ConvertTypeForMem(DeleteTy) ==
cast<llvm::PointerType>(Ptr->getType())->getElementType());
if (E->isArrayForm()) {
EmitArrayDelete(*this, E->getOperatorDelete(), Ptr, DeleteTy);
} else {
EmitObjectDelete(*this, E->getOperatorDelete(), Ptr, DeleteTy);
}
EmitBlock(DeleteEnd);
}
llvm::Value * CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) {
QualType Ty = E->getType();
const llvm::Type *LTy = ConvertType(Ty)->getPointerTo();
if (E->isTypeOperand()) {
llvm::Constant *TypeInfo =
CGM.GetAddrOfRTTIDescriptor(E->getTypeOperand());
return Builder.CreateBitCast(TypeInfo, LTy);
}
Expr *subE = E->getExprOperand();
Ty = subE->getType();
CanQualType CanTy = CGM.getContext().getCanonicalType(Ty);
Ty = CanTy.getUnqualifiedType().getNonReferenceType();
if (const RecordType *RT = Ty->getAs<RecordType>()) {
const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
if (RD->isPolymorphic()) {
// FIXME: if subE is an lvalue do
LValue Obj = EmitLValue(subE);
llvm::Value *This = Obj.getAddress();
LTy = LTy->getPointerTo()->getPointerTo();
llvm::Value *V = Builder.CreateBitCast(This, LTy);
// We need to do a zero check for *p, unless it has NonNullAttr.
// FIXME: PointerType->hasAttr<NonNullAttr>()
bool CanBeZero = false;
if (UnaryOperator *UO = dyn_cast<UnaryOperator>(subE->IgnoreParens()))
if (UO->getOpcode() == UO_Deref)
CanBeZero = true;
if (CanBeZero) {
llvm::BasicBlock *NonZeroBlock = createBasicBlock();
llvm::BasicBlock *ZeroBlock = createBasicBlock();
llvm::Value *Zero = llvm::Constant::getNullValue(LTy);
Builder.CreateCondBr(Builder.CreateICmpNE(V, Zero),
NonZeroBlock, ZeroBlock);
EmitBlock(ZeroBlock);
/// Call __cxa_bad_typeid
const llvm::Type *ResultType = llvm::Type::getVoidTy(VMContext);
const llvm::FunctionType *FTy;
FTy = llvm::FunctionType::get(ResultType, false);
llvm::Value *F = CGM.CreateRuntimeFunction(FTy, "__cxa_bad_typeid");
Builder.CreateCall(F)->setDoesNotReturn();
Builder.CreateUnreachable();
EmitBlock(NonZeroBlock);
}
V = Builder.CreateLoad(V, "vtable");
V = Builder.CreateConstInBoundsGEP1_64(V, -1ULL);
V = Builder.CreateLoad(V);
return V;
}
}
return Builder.CreateBitCast(CGM.GetAddrOfRTTIDescriptor(Ty), LTy);
}
llvm::Value *CodeGenFunction::EmitDynamicCast(llvm::Value *V,
const CXXDynamicCastExpr *DCE) {
QualType SrcTy = DCE->getSubExpr()->getType();
QualType DestTy = DCE->getTypeAsWritten();
QualType InnerType = DestTy->getPointeeType();
const llvm::Type *LTy = ConvertType(DCE->getType());
bool CanBeZero = false;
bool ToVoid = false;
bool ThrowOnBad = false;
if (DestTy->isPointerType()) {
// FIXME: if PointerType->hasAttr<NonNullAttr>(), we don't set this
CanBeZero = true;
if (InnerType->isVoidType())
ToVoid = true;
} else {
LTy = LTy->getPointerTo();
// FIXME: What if exceptions are disabled?
ThrowOnBad = true;
}
if (SrcTy->isPointerType() || SrcTy->isReferenceType())
SrcTy = SrcTy->getPointeeType();
SrcTy = SrcTy.getUnqualifiedType();
if (DestTy->isPointerType() || DestTy->isReferenceType())
DestTy = DestTy->getPointeeType();
DestTy = DestTy.getUnqualifiedType();
llvm::BasicBlock *ContBlock = createBasicBlock();
llvm::BasicBlock *NullBlock = 0;
llvm::BasicBlock *NonZeroBlock = 0;
if (CanBeZero) {
NonZeroBlock = createBasicBlock();
NullBlock = createBasicBlock();
Builder.CreateCondBr(Builder.CreateIsNotNull(V), NonZeroBlock, NullBlock);
EmitBlock(NonZeroBlock);
}
llvm::BasicBlock *BadCastBlock = 0;
const llvm::Type *PtrDiffTy = ConvertType(getContext().getPointerDiffType());
// See if this is a dynamic_cast(void*)
if (ToVoid) {
llvm::Value *This = V;
V = Builder.CreateBitCast(This, PtrDiffTy->getPointerTo()->getPointerTo());
V = Builder.CreateLoad(V, "vtable");
V = Builder.CreateConstInBoundsGEP1_64(V, -2ULL);
V = Builder.CreateLoad(V, "offset to top");
This = Builder.CreateBitCast(This, llvm::Type::getInt8PtrTy(VMContext));
V = Builder.CreateInBoundsGEP(This, V);
V = Builder.CreateBitCast(V, LTy);
} else {
/// Call __dynamic_cast
const llvm::Type *ResultType = llvm::Type::getInt8PtrTy(VMContext);
const llvm::FunctionType *FTy;
std::vector<const llvm::Type*> ArgTys;
const llvm::Type *PtrToInt8Ty
= llvm::Type::getInt8Ty(VMContext)->getPointerTo();
ArgTys.push_back(PtrToInt8Ty);
ArgTys.push_back(PtrToInt8Ty);
ArgTys.push_back(PtrToInt8Ty);
ArgTys.push_back(PtrDiffTy);
FTy = llvm::FunctionType::get(ResultType, ArgTys, false);
// FIXME: Calculate better hint.
llvm::Value *hint = llvm::ConstantInt::get(PtrDiffTy, -1ULL);
assert(SrcTy->isRecordType() && "Src type must be record type!");
assert(DestTy->isRecordType() && "Dest type must be record type!");
llvm::Value *SrcArg
= CGM.GetAddrOfRTTIDescriptor(SrcTy.getUnqualifiedType());
llvm::Value *DestArg
= CGM.GetAddrOfRTTIDescriptor(DestTy.getUnqualifiedType());
V = Builder.CreateBitCast(V, PtrToInt8Ty);
V = Builder.CreateCall4(CGM.CreateRuntimeFunction(FTy, "__dynamic_cast"),
V, SrcArg, DestArg, hint);
V = Builder.CreateBitCast(V, LTy);
if (ThrowOnBad) {
BadCastBlock = createBasicBlock();
Builder.CreateCondBr(Builder.CreateIsNotNull(V), ContBlock, BadCastBlock);
EmitBlock(BadCastBlock);
/// Invoke __cxa_bad_cast
ResultType = llvm::Type::getVoidTy(VMContext);
const llvm::FunctionType *FBadTy;
FBadTy = llvm::FunctionType::get(ResultType, false);
llvm::Value *F = CGM.CreateRuntimeFunction(FBadTy, "__cxa_bad_cast");
if (llvm::BasicBlock *InvokeDest = getInvokeDest()) {
llvm::BasicBlock *Cont = createBasicBlock("invoke.cont");
Builder.CreateInvoke(F, Cont, InvokeDest)->setDoesNotReturn();
EmitBlock(Cont);
} else {
// FIXME: Does this ever make sense?
Builder.CreateCall(F)->setDoesNotReturn();
}
Builder.CreateUnreachable();
}
}
if (CanBeZero) {
Builder.CreateBr(ContBlock);
EmitBlock(NullBlock);
Builder.CreateBr(ContBlock);
}
EmitBlock(ContBlock);
if (CanBeZero) {
llvm::PHINode *PHI = Builder.CreatePHI(LTy);
PHI->reserveOperandSpace(2);
PHI->addIncoming(V, NonZeroBlock);
PHI->addIncoming(llvm::Constant::getNullValue(LTy), NullBlock);
V = PHI;
}
return V;
}