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

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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 "clang/Frontend/CodeGenOptions.h"
#include "CodeGenFunction.h"
#include "CGCXXABI.h"
#include "CGObjCRuntime.h"
#include "CGDebugInfo.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);
}
static const CXXRecordDecl *getMostDerivedClassDecl(const Expr *Base) {
const Expr *E = Base;
while (true) {
E = E->IgnoreParens();
if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
if (CE->getCastKind() == CK_DerivedToBase ||
CE->getCastKind() == CK_UncheckedDerivedToBase ||
CE->getCastKind() == CK_NoOp) {
E = CE->getSubExpr();
continue;
}
}
break;
}
QualType DerivedType = E->getType();
if (const PointerType *PTy = DerivedType->getAs<PointerType>())
DerivedType = PTy->getPointeeType();
return cast<CXXRecordDecl>(DerivedType->castAs<RecordType>()->getDecl());
}
/// canDevirtualizeMemberFunctionCalls - Checks whether virtual calls on given
/// expr can be devirtualized.
static bool canDevirtualizeMemberFunctionCalls(ASTContext &Context,
const Expr *Base,
const CXXMethodDecl *MD) {
// When building with -fapple-kext, all calls must go through the vtable since
// the kernel linker can do runtime patching of vtables.
if (Context.getLangOptions().AppleKext)
return false;
// If the most derived class is marked final, we know that no subclass can
// override this member function and so we can devirtualize it. For example:
//
// struct A { virtual void f(); }
// struct B final : A { };
//
// void f(B *b) {
// b->f();
// }
//
const CXXRecordDecl *MostDerivedClassDecl = getMostDerivedClassDecl(Base);
if (MostDerivedClassDecl->hasAttr<FinalAttr>())
return true;
// If the member function is marked 'final', we know that it can't be
// overridden and can therefore devirtualize it.
if (MD->hasAttr<FinalAttr>())
return true;
// Similarly, if the class itself is marked 'final' it can't be overridden
// and we can therefore devirtualize the member function call.
if (MD->getParent()->hasAttr<FinalAttr>())
return true;
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;
}
// 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) {
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());
CGDebugInfo *DI = getDebugInfo();
if (DI && CGM.getCodeGenOpts().LimitDebugInfo
&& !isa<CallExpr>(ME->getBase())) {
QualType PQTy = ME->getBase()->IgnoreParenImpCasts()->getType();
if (const PointerType * PTy = dyn_cast<PointerType>(PQTy)) {
DI->getOrCreateRecordType(PTy->getPointeeType(),
MD->getParent()->getLocation());
}
}
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
This = EmitLValue(ME->getBase()).getAddress();
if (MD->isTrivial()) {
if (isa<CXXDestructorDecl>(MD)) return RValue::get(0);
if (isa<CXXConstructorDecl>(MD) &&
cast<CXXConstructorDecl>(MD)->isDefaultConstructor())
return RValue::get(0);
if (MD->isCopyAssignmentOperator()) {
// 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);
}
if (isa<CXXConstructorDecl>(MD) &&
cast<CXXConstructorDecl>(MD)->isCopyConstructor()) {
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 CGFunctionInfo *FInfo = 0;
if (isa<CXXDestructorDecl>(MD))
FInfo = &CGM.getTypes().getFunctionInfo(cast<CXXDestructorDecl>(MD),
Dtor_Complete);
else if (isa<CXXConstructorDecl>(MD))
FInfo = &CGM.getTypes().getFunctionInfo(cast<CXXConstructorDecl>(MD),
Ctor_Complete);
else
FInfo = &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;
UseVirtualCall = MD->isVirtual() && !ME->hasQualifier()
&& !canDevirtualizeMemberFunctionCalls(getContext(),
ME->getBase(), MD);
llvm::Value *Callee;
if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(MD)) {
if (UseVirtualCall) {
Callee = BuildVirtualCall(Dtor, Dtor_Complete, This, Ty);
} else {
if (getContext().getLangOptions().AppleKext &&
MD->isVirtual() &&
ME->hasQualifier())
Callee = BuildAppleKextVirtualCall(MD, ME->getQualifier(), Ty);
else
Callee = CGM.GetAddrOfFunction(GlobalDecl(Dtor, Dtor_Complete), Ty);
}
} else if (const CXXConstructorDecl *Ctor =
dyn_cast<CXXConstructorDecl>(MD)) {
Callee = CGM.GetAddrOfFunction(GlobalDecl(Ctor, Ctor_Complete), Ty);
} else if (UseVirtualCall) {
Callee = BuildVirtualCall(MD, This, Ty);
} else {
if (getContext().getLangOptions().AppleKext &&
MD->isVirtual() &&
ME->hasQualifier())
Callee = BuildAppleKextVirtualCall(MD, ME->getQualifier(), 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(*this, 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!");
LValue LV = EmitLValue(E->getArg(0));
llvm::Value *This = LV.getAddress();
if (MD->isCopyAssignmentOperator()) {
const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(MD->getDeclContext());
if (ClassDecl->hasTrivialCopyAssignment()) {
assert(!ClassDecl->hasUserDeclaredCopyAssignment() &&
"EmitCXXOperatorMemberCallExpr - user declared copy assignment");
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());
llvm::Value *Callee;
if (MD->isVirtual() &&
!canDevirtualizeMemberFunctionCalls(getContext(),
E->getArg(0), MD))
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;
// Elide the constructor if we're constructing from a temporary.
// The temporary check is required because Sema sets this on NRVO
// returns.
if (getContext().getLangOptions().ElideConstructors && E->isElidable()) {
assert(getContext().hasSameUnqualifiedType(E->getType(),
E->getArg(0)->getType()));
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());
}
}
void
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());
assert(!getContext().getAsConstantArrayType(E->getType())
&& "EmitSynthesizedCXXCopyCtor - Copied-in Array");
EmitSynthesizedCXXCopyCtorCall(CD, Dest, Src,
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);
}
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 = 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.trunc(SizeWidth);
SizeWithoutCookie = llvm::ConstantInt::get(SizeTy, SWC);
// Add the cookie size.
SC += llvm::APInt(SizeWidth*2, CookieSize.getQuantity());
}
if (SC.countLeadingZeros() >= SizeWidth) {
SC = 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.CreateOr(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) {
CGF.EmitCastToVoidPtr(NewPtr);
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,
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);
}
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;
DominatingValue<RValue>::saved_type Ptr;
DominatingValue<RValue>::saved_type AllocSize;
DominatingValue<RValue>::saved_type *getPlacementArgs() {
return reinterpret_cast<DominatingValue<RValue>::saved_type*>(this+1);
}
public:
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, 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(Ptr.restore(CGF), *AI++));
// A member 'operator delete' can take an extra 'size_t' argument.
if (FPT->getNumArgs() == NumPlacementArgs + 2) {
RValue RV = AllocSize.restore(CGF);
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 = getPlacementArgs()[I].restore(CGF);
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.
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
.pushCleanupWithExtra<CallDeleteDuringConditionalNew>(InactiveEHCleanup,
E->getNumPlacementArgs(),
E->getOperatorDelete(),
SavedNewPtr,
SavedAllocSize);
for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I)
Cleanup->setPlacementArg(I,
DominatingValue<RValue>::save(CGF, NewArgs[I+1].first));
CGF.ActivateCleanupBlock(CGF.EHStack.stable_begin());
}
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 =
allocator->getType()->castAs<FunctionProtoType>();
CallArgList allocatorArgs;
// The allocation size is the first argument.
QualType sizeType = getContext().getSizeType();
llvm::Value *numElements = 0;
llvm::Value *allocSizeWithoutCookie = 0;
llvm::Value *allocSize =
EmitCXXNewAllocSize(getContext(), *this, E, numElements,
allocSizeWithoutCookie);
allocatorArgs.push_back(std::make_pair(RValue::get(allocSize), sizeType));
// Emit the rest of the arguments.
// FIXME: Ideally, this should just use EmitCallArgs.
CXXNewExpr::const_arg_iterator placementArg = 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 = allocatorType->getNumArgs(); i != e;
++i, ++placementArg) {
QualType argType = allocatorType->getArgType(i);
assert(getContext().hasSameUnqualifiedType(argType.getNonReferenceType(),
placementArg->getType()) &&
"type mismatch in call argument!");
EmitCallArg(allocatorArgs, *placementArg, argType);
}
// Either we've emitted all the call args, or we have a call to a
// variadic function.
assert((placementArg == E->placement_arg_end() ||
allocatorType->isVariadic()) &&
"Extra arguments to non-variadic function!");
// If we still have any arguments, emit them using the type of the argument.
for (CXXNewExpr::const_arg_iterator placementArgsEnd = E->placement_arg_end();
placementArg != placementArgsEnd; ++placementArg) {
EmitCallArg(allocatorArgs, *placementArg, placementArg->getType());
}
// Emit the allocation call.
RValue RV =
EmitCall(CGM.getTypes().getFunctionInfo(allocatorArgs, allocatorType),
CGM.GetAddrOfFunction(allocator), ReturnValueSlot(),
allocatorArgs, allocator);
// 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() && !E->hasInitializer());
llvm::BasicBlock *nullCheckBB = 0;
llvm::BasicBlock *contBB = 0;
llvm::Value *allocation = RV.getScalarVal();
unsigned AS =
cast<llvm::PointerType>(allocation->getType())->getAddressSpace();
// The null-check means that the initializer is conditionally
// evaluated.
ConditionalEvaluation conditional(*this);
if (nullCheck) {
conditional.begin(*this);
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);
EmitBlock(notNullBB);
}
assert((allocSize == allocSizeWithoutCookie) ==
CalculateCookiePadding(*this, E).isZero());
if (allocSize != allocSizeWithoutCookie) {
assert(E->isArray());
allocation = CGM.getCXXABI().InitializeArrayCookie(*this, allocation,
numElements,
E, allocType);
}
// If there's an operator delete, enter a cleanup to call it if an
// exception is thrown.
EHScopeStack::stable_iterator operatorDeleteCleanup;
if (E->getOperatorDelete()) {
EnterNewDeleteCleanup(*this, E, allocation, allocSize, allocatorArgs);
operatorDeleteCleanup = EHStack.stable_begin();
}
const llvm::Type *elementPtrTy
= ConvertTypeForMem(allocType)->getPointerTo(AS);
llvm::Value *result = Builder.CreateBitCast(allocation, elementPtrTy);
if (E->isArray()) {
EmitNewInitializer(*this, E, result, 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 *resultType = ConvertTypeForMem(E->getType());
if (result->getType() != resultType)
result = Builder.CreateBitCast(result, resultType);
} else {
EmitNewInitializer(*this, E, result, numElements, allocSizeWithoutCookie);
}
// Deactivate the 'operator delete' cleanup if we finished
// initialization.
if (operatorDeleteCleanup.isValid())
DeactivateCleanupBlock(operatorDeleteCleanup);
if (nullCheck) {
conditional.end(*this);
llvm::BasicBlock *notNullBB = Builder.GetInsertBlock();
EmitBlock(contBB);
llvm::PHINode *PHI = Builder.CreatePHI(result->getType(), 2);
PHI->addIncoming(result, notNullBB);
PHI->addIncoming(llvm::Constant::getNullValue(result->getType()),
nullCheckBB);
result = PHI;
}
return result;
}
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.
// This doesn't have to a conditional cleanup because we're going
// to pop it off in a second.
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 CXXDeleteExpr *E,
llvm::Value *Ptr,
QualType ElementType) {
llvm::Value *NumElements = 0;
llvm::Value *AllocatedPtr = 0;
CharUnits CookieSize;
CGF.CGM.getCXXABI().ReadArrayCookie(CGF, Ptr, E, ElementType,
NumElements, AllocatedPtr, CookieSize);
assert(AllocatedPtr && "ReadArrayCookie didn't set AllocatedPtr");
// Make sure that we call delete even if one of the dtors throws.
const FunctionDecl *OperatorDelete = E->getOperatorDelete();
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, 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();
// 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(This->getType());
Builder.CreateCondBr(Builder.CreateICmpNE(This, Zero),
NonZeroBlock, ZeroBlock);
EmitBlock(ZeroBlock);
/// Call __cxa_bad_typeid
const llvm::Type *ResultType = llvm::Type::getVoidTy(getLLVMContext());
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);
}
llvm::Value *V = GetVTablePtr(This, LTy->getPointerTo());
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 = GetVTablePtr(This, PtrDiffTy->getPointerTo());
V = Builder.CreateConstInBoundsGEP1_64(V, -2ULL);
V = Builder.CreateLoad(V, "offset to top");
This = EmitCastToVoidPtr(This);
V = Builder.CreateInBoundsGEP(This, V);
V = Builder.CreateBitCast(V, LTy);
} else {
/// Call __dynamic_cast
const llvm::Type *ResultType = Int8PtrTy;
const llvm::FunctionType *FTy;
std::vector<const llvm::Type*> ArgTys;
ArgTys.push_back(Int8PtrTy);
ArgTys.push_back(Int8PtrTy);
ArgTys.push_back(Int8PtrTy);
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, Int8PtrTy);
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(getLLVMContext());
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, 2);
PHI->addIncoming(V, NonZeroBlock);
PHI->addIncoming(llvm::Constant::getNullValue(LTy), NullBlock);
V = PHI;
}
return V;
}
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