OSchip
/
llvm-project
mirror of https://github.com/THU-DSP-LAB/llvm-project.git
13
0
Fork 6
Code Issues Packages Projects Releases Wiki Activity
llvm-project/clang/lib/CodeGen/CGExprCXX.cpp

927 lines
33 KiB
C++
Raw Blame History

//===--- 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"
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->getCallConv(),
FPT->getNoReturnAttr()), 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());
}
const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();
const llvm::Type *Ty =
CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(MD),
FPT->isVariadic());
llvm::Value *This;
if (ME->isArrow())
This = EmitScalarExpr(ME->getBase());
else {
LValue BaseLV = EmitLValue(ME->getBase());
This = BaseLV.getAddress();
}
if (MD->isCopyAssignment() && MD->isTrivial()) {
// 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);
}
// 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.
llvm::Value *Callee;
if (const CXXDestructorDecl *Destructor
= dyn_cast<CXXDestructorDecl>(MD)) {
if (Destructor->isTrivial())
return RValue::get(0);
if (MD->isVirtual() && !ME->hasQualifier() &&
!canDevirtualizeMemberFunctionCalls(ME->getBase())) {
Callee = BuildVirtualCall(Destructor, Dtor_Complete, This, Ty);
} else {
Callee = CGM.GetAddrOfFunction(GlobalDecl(Destructor, Dtor_Complete), Ty);
}
} else if (MD->isVirtual() && !ME->hasQualifier() &&
!canDevirtualizeMemberFunctionCalls(ME->getBase())) {
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());
const llvm::FunctionType *FTy =
CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(RD, FPT),
FPT->isVariadic());
const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(VMContext);
// Get the member function pointer.
llvm::Value *MemFnPtr = CreateMemTemp(MemFnExpr->getType(), "mem.fn");
EmitAggExpr(MemFnExpr, MemFnPtr, /*VolatileDest=*/false);
// Emit the 'this' pointer.
llvm::Value *This;
if (BO->getOpcode() == BinaryOperator::PtrMemI)
This = EmitScalarExpr(BaseExpr);
else
This = EmitLValue(BaseExpr).getAddress();
// Adjust it.
llvm::Value *Adj = Builder.CreateStructGEP(MemFnPtr, 1);
Adj = Builder.CreateLoad(Adj, "mem.fn.adj");
llvm::Value *Ptr = Builder.CreateBitCast(This, Int8PtrTy, "ptr");
Ptr = Builder.CreateGEP(Ptr, Adj, "adj");
This = Builder.CreateBitCast(Ptr, This->getType(), "this");
llvm::Value *FnPtr = Builder.CreateStructGEP(MemFnPtr, 0, "mem.fn.ptr");
const llvm::Type *PtrDiffTy = ConvertType(getContext().getPointerDiffType());
llvm::Value *FnAsInt = Builder.CreateLoad(FnPtr, "fn");
// If the LSB in the function pointer is 1, the function pointer points to
// a virtual function.
llvm::Value *IsVirtual
= Builder.CreateAnd(FnAsInt, llvm::ConstantInt::get(PtrDiffTy, 1),
"and");
IsVirtual = Builder.CreateTrunc(IsVirtual,
llvm::Type::getInt1Ty(VMContext));
llvm::BasicBlock *FnVirtual = createBasicBlock("fn.virtual");
llvm::BasicBlock *FnNonVirtual = createBasicBlock("fn.nonvirtual");
llvm::BasicBlock *FnEnd = createBasicBlock("fn.end");
Builder.CreateCondBr(IsVirtual, FnVirtual, FnNonVirtual);
EmitBlock(FnVirtual);
const llvm::Type *VtableTy =
FTy->getPointerTo()->getPointerTo();
llvm::Value *Vtable = Builder.CreateBitCast(This, VtableTy->getPointerTo());
Vtable = Builder.CreateLoad(Vtable);
Vtable = Builder.CreateBitCast(Vtable, Int8PtrTy);
llvm::Value *VtableOffset =
Builder.CreateSub(FnAsInt, llvm::ConstantInt::get(PtrDiffTy, 1));
Vtable = Builder.CreateGEP(Vtable, VtableOffset, "fn");
Vtable = Builder.CreateBitCast(Vtable, VtableTy);
llvm::Value *VirtualFn = Builder.CreateLoad(Vtable, "virtualfn");
EmitBranch(FnEnd);
EmitBlock(FnNonVirtual);
// If the function is not virtual, just load the pointer.
llvm::Value *NonVirtualFn = Builder.CreateLoad(FnPtr, "fn");
NonVirtualFn = Builder.CreateIntToPtr(NonVirtualFn, FTy->getPointerTo());
EmitBlock(FnEnd);
llvm::PHINode *Callee = Builder.CreatePHI(FTy->getPointerTo());
Callee->reserveOperandSpace(2);
Callee->addIncoming(VirtualFn, FnVirtual);
Callee->addIncoming(NonVirtualFn, FnNonVirtual);
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");
llvm::Value *This = EmitLValue(E->getArg(0)).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());
llvm::Value *This = EmitLValue(E->getArg(0)).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(llvm::Value *Dest,
const CXXConstructExpr *E) {
assert(Dest && "Must have a destination!");
const CXXConstructorDecl *CD = E->getConstructor();
const ConstantArrayType *Array =
getContext().getAsConstantArrayType(E->getType());
// For a copy constructor, even if it is trivial, must fall thru so
// its argument is code-gen'ed.
if (!CD->isCopyConstructor()) {
QualType InitType = E->getType();
if (Array)
InitType = getContext().getBaseElementType(Array);
const CXXRecordDecl *RD =
cast<CXXRecordDecl>(InitType->getAs<RecordType>()->getDecl());
if (RD->hasTrivialConstructor())
return;
}
// Code gen optimization to eliminate copy constructor and return
// its first argument instead.
if (getContext().getLangOptions().ElideConstructors && E->isElidable()) {
const Expr *Arg = E->getArg(0);
if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg)) {
assert((ICE->getCastKind() == CastExpr::CK_NoOp ||
ICE->getCastKind() == CastExpr::CK_ConstructorConversion ||
ICE->getCastKind() == CastExpr::CK_UserDefinedConversion) &&
"Unknown implicit cast kind in constructor elision");
Arg = ICE->getSubExpr();
}
if (const CXXFunctionalCastExpr *FCE = dyn_cast<CXXFunctionalCastExpr>(Arg))
Arg = FCE->getSubExpr();
if (const CXXBindTemporaryExpr *BindExpr =
dyn_cast<CXXBindTemporaryExpr>(Arg))
Arg = BindExpr->getSubExpr();
EmitAggExpr(Arg, Dest, false);
return;
}
if (Array) {
QualType BaseElementTy = getContext().getBaseElementType(Array);
const llvm::Type *BasePtr = ConvertType(BaseElementTy);
BasePtr = llvm::PointerType::getUnqual(BasePtr);
llvm::Value *BaseAddrPtr =
Builder.CreateBitCast(Dest, BasePtr);
EmitCXXAggrConstructorCall(CD, Array, BaseAddrPtr,
E->arg_begin(), E->arg_end());
}
else
// Call the constructor.
EmitCXXConstructorCall(CD,
E->isBaseInitialization()? Ctor_Base : Ctor_Complete,
Dest,
E->arg_begin(), E->arg_end());
}
static CharUnits CalculateCookiePadding(ASTContext &Ctx, QualType ElementType) {
const RecordType *RT = ElementType->getAs<RecordType>();
if (!RT)
return CharUnits::Zero();
const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl());
if (!RD)
return CharUnits::Zero();
// Check if the class has a trivial destructor.
if (RD->hasTrivialDestructor()) {
// Check if the usual deallocation function takes two arguments.
const CXXMethodDecl *UsualDeallocationFunction = 0;
DeclarationName OpName =
Ctx.DeclarationNames.getCXXOperatorName(OO_Array_Delete);
DeclContext::lookup_const_iterator Op, OpEnd;
for (llvm::tie(Op, OpEnd) = RD->lookup(OpName);
Op != OpEnd; ++Op) {
const CXXMethodDecl *Delete = cast<CXXMethodDecl>(*Op);
if (Delete->isUsualDeallocationFunction()) {
UsualDeallocationFunction = Delete;
break;
}
}
// No usual deallocation function, we don't need a cookie.
if (!UsualDeallocationFunction)
return CharUnits::Zero();
// The usual deallocation function doesn't take a size_t argument, so we
// don't need a cookie.
if (UsualDeallocationFunction->getNumParams() == 1)
return CharUnits::Zero();
assert(UsualDeallocationFunction->getNumParams() == 2 &&
"Unexpected deallocation function type!");
}
// Padding is the maximum of sizeof(size_t) and alignof(ElementType)
return std::max(Ctx.getTypeSizeInChars(Ctx.getSizeType()),
Ctx.getTypeAlignInChars(ElementType));
}
static CharUnits CalculateCookiePadding(ASTContext &Ctx, 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 (OperatorNew->getDeclContext()->getLookupContext()->isFileContext()) {
if (OperatorNew->getNumParams() == 2) {
CanQualType ParamType =
Ctx.getCanonicalType(OperatorNew->getParamDecl(1)->getType());
if (ParamType == Ctx.VoidPtrTy)
return CharUnits::Zero();
}
}
return CalculateCookiePadding(Ctx, E->getAllocatedType());
}
static llvm::Value *EmitCXXNewAllocSize(CodeGenFunction &CGF,
const CXXNewExpr *E,
llvm::Value *& NumElements) {
QualType Type = E->getAllocatedType();
CharUnits TypeSize = CGF.getContext().getTypeSizeInChars(Type);
const llvm::Type *SizeTy = CGF.ConvertType(CGF.getContext().getSizeType());
if (!E->isArray())
return llvm::ConstantInt::get(SizeTy, TypeSize.getQuantity());
CharUnits CookiePadding = CalculateCookiePadding(CGF.getContext(), E);
Expr::EvalResult Result;
if (E->getArraySize()->Evaluate(Result, CGF.getContext()) &&
!Result.HasSideEffects && Result.Val.isInt()) {
CharUnits AllocSize =
Result.Val.getInt().getZExtValue() * TypeSize + CookiePadding;
NumElements =
llvm::ConstantInt::get(SizeTy, Result.Val.getInt().getZExtValue());
return llvm::ConstantInt::get(SizeTy, AllocSize.getQuantity());
}
// Emit the array size expression.
NumElements = CGF.EmitScalarExpr(E->getArraySize());
// Multiply with the type size.
llvm::Value *V =
CGF.Builder.CreateMul(NumElements,
llvm::ConstantInt::get(SizeTy,
TypeSize.getQuantity()));
// And add the cookie padding if necessary.
if (!CookiePadding.isZero())
V = CGF.Builder.CreateAdd(V,
llvm::ConstantInt::get(SizeTy, CookiePadding.getQuantity()));
return V;
}
static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E,
llvm::Value *NewPtr,
llvm::Value *NumElements) {
if (E->isArray()) {
if (CXXConstructorDecl *Ctor = E->getConstructor())
CGF.EmitCXXAggrConstructorCall(Ctor, NumElements, NewPtr,
E->constructor_arg_begin(),
E->constructor_arg_end());
return;
}
QualType AllocType = E->getAllocatedType();
if (CXXConstructorDecl *Ctor = E->getConstructor()) {
CGF.EmitCXXConstructorCall(Ctor, Ctor_Complete, NewPtr,
E->constructor_arg_begin(),
E->constructor_arg_end());
return;
}
// We have a POD type.
if (E->getNumConstructorArgs() == 0)
return;
assert(E->getNumConstructorArgs() == 1 &&
"Can only have one argument to initializer of POD type.");
const Expr *Init = E->getConstructorArg(0);
if (!CGF.hasAggregateLLVMType(AllocType))
CGF.EmitStoreOfScalar(CGF.EmitScalarExpr(Init), NewPtr,
AllocType.isVolatileQualified(), AllocType);
else if (AllocType->isAnyComplexType())
CGF.EmitComplexExprIntoAddr(Init, NewPtr,
AllocType.isVolatileQualified());
else
CGF.EmitAggExpr(Init, NewPtr, AllocType.isVolatileQualified());
}
llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
QualType AllocType = E->getAllocatedType();
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 *AllocSize = EmitCXXNewAllocSize(*this, E, NumElements);
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 *NewNull = 0;
llvm::BasicBlock *NewNotNull = 0;
llvm::BasicBlock *NewEnd = 0;
llvm::Value *NewPtr = RV.getScalarVal();
if (NullCheckResult) {
NewNull = createBasicBlock("new.null");
NewNotNull = createBasicBlock("new.notnull");
NewEnd = createBasicBlock("new.end");
llvm::Value *IsNull =
Builder.CreateICmpEQ(NewPtr,
llvm::Constant::getNullValue(NewPtr->getType()),
"isnull");
Builder.CreateCondBr(IsNull, NewNull, NewNotNull);
EmitBlock(NewNotNull);
}
CharUnits CookiePadding = CalculateCookiePadding(getContext(), E);
if (!CookiePadding.isZero()) {
CharUnits CookieOffset =
CookiePadding - getContext().getTypeSizeInChars(SizeTy);
llvm::Value *NumElementsPtr =
Builder.CreateConstInBoundsGEP1_64(NewPtr, CookieOffset.getQuantity());
NumElementsPtr = Builder.CreateBitCast(NumElementsPtr,
ConvertType(SizeTy)->getPointerTo());
Builder.CreateStore(NumElements, NumElementsPtr);
// Now add the padding to the new ptr.
NewPtr = Builder.CreateConstInBoundsGEP1_64(NewPtr,
CookiePadding.getQuantity());
}
NewPtr = Builder.CreateBitCast(NewPtr, ConvertType(E->getType()));
EmitNewInitializer(*this, E, NewPtr, NumElements);
if (NullCheckResult) {
Builder.CreateBr(NewEnd);
NewNotNull = Builder.GetInsertBlock();
EmitBlock(NewNull);
Builder.CreateBr(NewEnd);
EmitBlock(NewEnd);
llvm::PHINode *PHI = Builder.CreatePHI(NewPtr->getType());
PHI->reserveOperandSpace(2);
PHI->addIncoming(NewPtr, NewNotNull);
PHI->addIncoming(llvm::Constant::getNullValue(NewPtr->getType()), NewNull);
NewPtr = PHI;
}
return NewPtr;
}
static std::pair<llvm::Value *, llvm::Value *>
GetAllocatedObjectPtrAndNumElements(CodeGenFunction &CGF,
llvm::Value *Ptr, QualType DeleteTy) {
QualType SizeTy = CGF.getContext().getSizeType();
const llvm::Type *SizeLTy = CGF.ConvertType(SizeTy);
CharUnits DeleteTypeAlign = CGF.getContext().getTypeAlignInChars(DeleteTy);
CharUnits CookiePadding =
std::max(CGF.getContext().getTypeSizeInChars(SizeTy),
DeleteTypeAlign);
assert(!CookiePadding.isZero() && "CookiePadding should not be 0.");
const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(CGF.getLLVMContext());
CharUnits CookieOffset =
CookiePadding - CGF.getContext().getTypeSizeInChars(SizeTy);
llvm::Value *AllocatedObjectPtr = CGF.Builder.CreateBitCast(Ptr, Int8PtrTy);
AllocatedObjectPtr =
CGF.Builder.CreateConstInBoundsGEP1_64(AllocatedObjectPtr,
-CookiePadding.getQuantity());
llvm::Value *NumElementsPtr =
CGF.Builder.CreateConstInBoundsGEP1_64(AllocatedObjectPtr,
CookieOffset.getQuantity());
NumElementsPtr =
CGF.Builder.CreateBitCast(NumElementsPtr, SizeLTy->getPointerTo());
llvm::Value *NumElements = CGF.Builder.CreateLoad(NumElementsPtr);
NumElements =
CGF.Builder.CreateIntCast(NumElements, SizeLTy, /*isSigned=*/false);
return std::make_pair(AllocatedObjectPtr, NumElements);
}
void CodeGenFunction::EmitDeleteCall(const FunctionDecl *DeleteFD,
llvm::Value *Ptr,
QualType DeleteTy) {
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());
}
if (DeleteFD->getOverloadedOperator() == OO_Array_Delete &&
!CalculateCookiePadding(getContext(), DeleteTy).isZero()) {
// We need to get the number of elements in the array from the cookie.
llvm::Value *AllocatedObjectPtr;
llvm::Value *NumElements;
llvm::tie(AllocatedObjectPtr, NumElements) =
GetAllocatedObjectPtrAndNumElements(*this, Ptr, DeleteTy);
// Multiply the size with the number of elements.
if (Size)
Size = Builder.CreateMul(NumElements, Size);
Ptr = AllocatedObjectPtr;
}
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);
}
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() != CastExpr::CK_UserDefinedConversion &&
ICE->getType()->isVoidPointerType())
Arg = ICE->getSubExpr();
else
break;
}
QualType DeleteTy = Arg->getType()->getAs<PointerType>()->getPointeeType();
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);
bool ShouldCallDelete = true;
// Call the destructor if necessary.
if (const RecordType *RT = DeleteTy->getAs<RecordType>()) {
if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
if (!RD->hasTrivialDestructor()) {
const CXXDestructorDecl *Dtor = RD->getDestructor(getContext());
if (E->isArrayForm()) {
llvm::Value *AllocatedObjectPtr;
llvm::Value *NumElements;
llvm::tie(AllocatedObjectPtr, NumElements) =
GetAllocatedObjectPtrAndNumElements(*this, Ptr, DeleteTy);
EmitCXXAggrDestructorCall(Dtor, NumElements, Ptr);
} else if (Dtor->isVirtual()) {
const llvm::Type *Ty =
CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(Dtor),
/*isVariadic=*/false);
llvm::Value *Callee = BuildVirtualCall(Dtor, Dtor_Deleting, Ptr, Ty);
EmitCXXMemberCall(Dtor, Callee, ReturnValueSlot(), Ptr, /*VTT=*/0,
0, 0);
// The dtor took care of deleting the object.
ShouldCallDelete = false;
} else
EmitCXXDestructorCall(Dtor, Dtor_Complete, Ptr);
}
}
}
if (ShouldCallDelete)
EmitDeleteCall(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() == UnaryOperator::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();
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);
/// Call __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");
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;
}
Reference in New Issue View Git Blame Copy Permalink