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//===--- CGCXXExpr.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;
llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) {
if (E->isArray()) {
ErrorUnsupported(E, "new[] expression");
return llvm::UndefValue::get(ConvertType(E->getType()));
}
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 *AllocSize =
llvm::ConstantInt::get(ConvertType(SizeTy),
getContext().getTypeSize(AllocType) / 8);
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(NewFTy->getResultType(), NewArgs),
CGM.GetAddrOfFunction(NewFD), 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);
}
NewPtr = Builder.CreateBitCast(NewPtr, ConvertType(E->getType()));
if (AllocType->isPODType()) {
if (E->getNumConstructorArgs() > 0) {
assert(E->getNumConstructorArgs() == 1 &&
"Can only have one argument to initializer of POD type.");
const Expr *Init = E->getConstructorArg(0);
if (!hasAggregateLLVMType(AllocType))
Builder.CreateStore(EmitScalarExpr(Init), NewPtr);
else if (AllocType->isAnyComplexType())
EmitComplexExprIntoAddr(Init, NewPtr, AllocType.isVolatileQualified());
else
EmitAggExpr(Init, NewPtr, AllocType.isVolatileQualified());
}
} else {
// Call the constructor.
CXXConstructorDecl *Ctor = E->getConstructor();
EmitCXXConstructorCall(Ctor, Ctor_Complete, NewPtr,
E->constructor_arg_begin(),
E->constructor_arg_end());
}
if (NullCheckResult) {
Builder.CreateBr(NewEnd);
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;
}
void CodeGenFunction::EmitCXXDeleteExpr(const CXXDeleteExpr *E) {
if (E->isArrayForm()) {
ErrorUnsupported(E, "delete[] expression");
return;
};
QualType DeleteTy =
E->getArgument()->getType()->getAs<PointerType>()->getPointeeType();
llvm::Value *Ptr = EmitScalarExpr(E->getArgument());
// 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);
// 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 (Dtor->isVirtual()) {
const llvm::Type *Ty =
CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(Dtor),
/*isVariadic=*/false);
llvm::Value *Callee = BuildVirtualCall(Dtor, Ptr, Ty);
EmitCXXMemberCall(Dtor, Callee, Ptr, 0, 0);
} else
EmitCXXDestructorCall(Dtor, Dtor_Complete, Ptr);
}
}
}
// Call delete.
FunctionDecl *DeleteFD = E->getOperatorDelete();
const FunctionProtoType *DeleteFTy =
DeleteFD->getType()->getAs<FunctionProtoType>();
CallArgList DeleteArgs;
QualType ArgTy = DeleteFTy->getArgType(0);
llvm::Value *DeletePtr = Builder.CreateBitCast(Ptr, ConvertType(ArgTy));
DeleteArgs.push_back(std::make_pair(RValue::get(DeletePtr), ArgTy));
// Emit the call to delete.
EmitCall(CGM.getTypes().getFunctionInfo(DeleteFTy->getResultType(),
DeleteArgs),
CGM.GetAddrOfFunction(DeleteFD),
DeleteArgs, DeleteFD);
EmitBlock(DeleteEnd);
}
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