[cfe-commits] r88901 - in /cfe/trunk/lib/CodeGen: CGCXXExpr.cpp CGExpr.cpp CGExprScalar.cpp CodeGenFunction.h
Mike Stump
mrs at apple.com
Sun Nov 15 22:50:58 PST 2009
Author: mrs
Date: Mon Nov 16 00:50:58 2009
New Revision: 88901
URL: http://llvm.org/viewvc/llvm-project?rev=88901&view=rev
Log:
Implement most of dynamic_cast. WIP.
Modified:
cfe/trunk/lib/CodeGen/CGCXXExpr.cpp
cfe/trunk/lib/CodeGen/CGExpr.cpp
cfe/trunk/lib/CodeGen/CGExprScalar.cpp
cfe/trunk/lib/CodeGen/CodeGenFunction.h
Modified: cfe/trunk/lib/CodeGen/CGCXXExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCXXExpr.cpp?rev=88901&r1=88900&r2=88901&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCXXExpr.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGCXXExpr.cpp Mon Nov 16 00:50:58 2009
@@ -388,7 +388,8 @@
const llvm::FunctionType *FTy;
FTy = llvm::FunctionType::get(ResultType, false);
llvm::Value *F = CGM.CreateRuntimeFunction(FTy, "__cxa_bad_typeid");
- Builder.CreateCall(F);
+ Builder.CreateCall(F)->setDoesNotReturn();
+ // FIXME: Should we have the below?
Builder.CreateUnreachable();
EmitBlock(NonZeroBlock);
}
@@ -403,3 +404,111 @@
ErrorUnsupported(E, "typeid expression");
return 0;
}
+
+llvm::Value *CodeGenFunction::EmitDynamicCast(llvm::Value *V,
+ const CXXDynamicCastExpr *DCE) {
+ QualType CastTy = DCE->getTypeAsWritten();
+ QualType ArgTy = DCE->getSubExpr()->getType();
+ const llvm::Type *LArgTy = ConvertType(ArgTy);
+ const llvm::Type *LTy = ConvertType(DCE->getType());
+ CXXRecordDecl *SrcTy;
+ CXXRecordDecl *DstTy;
+ QualType Ty = CastTy.getTypePtr()->getPointeeType();
+ CanQualType CanTy = CGM.getContext().getCanonicalType(Ty);
+ Ty = CanTy.getUnqualifiedType();
+ DstTy = cast<CXXRecordDecl>(Ty->getAs<RecordType>()->getDecl());
+ Ty = ArgTy;
+ if (ArgTy.getTypePtr()->isPointerType()
+ || ArgTy.getTypePtr()->isReferenceType())
+ Ty = Ty.getTypePtr()->getPointeeType();
+ CanTy = CGM.getContext().getCanonicalType(Ty);
+ Ty = CanTy.getUnqualifiedType();
+ SrcTy = cast<CXXRecordDecl>(Ty->getAs<RecordType>()->getDecl());
+ bool CanBeZero = false;
+ bool ThrowOnBad = false;
+ bool ToVoid = false;
+ QualType InnerType = CastTy->getPointeeType();
+ if (CastTy->isPointerType()) {
+ // FIXME: if PointerType->hasAttr<NonNullAttr>(), we don't set this
+ CanBeZero = true;
+ if (InnerType->isVoidType())
+ ToVoid = true;
+ } else {
+ LTy = LTy->getPointerTo();
+ ThrowOnBad = true;
+ }
+
+ // FIXME: Add support for ToVoid
+
+ // FIXME: Ensure non-runtime casts are done before this point.
+
+ llvm::BasicBlock *ContBlock = createBasicBlock();
+ llvm::BasicBlock *NullBlock = 0;
+ llvm::BasicBlock *NonZeroBlock = 0;
+ if (CanBeZero) {
+ NonZeroBlock = createBasicBlock();
+ NullBlock = createBasicBlock();
+ llvm::Value *Zero = llvm::Constant::getNullValue(LArgTy);
+ Builder.CreateCondBr(Builder.CreateICmpNE(V, Zero),
+ NonZeroBlock, NullBlock);
+ EmitBlock(NonZeroBlock);
+ }
+
+
+ /// 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();
+ const llvm::Type *PtrDiffTy = ConvertType(getContext().getSizeType());
+ 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);
+ llvm::Value *SrcArg = CGM.GenerateRttiRef(SrcTy);
+ llvm::Value *DstArg = CGM.GenerateRttiRef(DstTy);
+ V = Builder.CreateBitCast(V, PtrToInt8Ty);
+ V = Builder.CreateCall4(CGM.CreateRuntimeFunction(FTy, "__dynamic_cast"),
+ V, SrcArg, DstArg, hint);
+ V = Builder.CreateBitCast(V, LTy);
+
+ llvm::BasicBlock *BadCastBlock = 0;
+ if (ThrowOnBad) {
+ BadCastBlock = createBasicBlock();
+
+ llvm::Value *Zero = llvm::Constant::getNullValue(LTy);
+ Builder.CreateCondBr(Builder.CreateICmpNE(V, Zero),
+ ContBlock, BadCastBlock);
+ EmitBlock(BadCastBlock);
+ /// Call __cxa_bad_cast
+ ResultType = llvm::Type::getVoidTy(VMContext);
+ const llvm::FunctionType *FBadTy;
+ FTy = 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(3);
+ PHI->addIncoming(V, NonZeroBlock);
+ PHI->addIncoming(llvm::Constant::getNullValue(LTy), NullBlock);
+ if (ThrowOnBad)
+ PHI->addIncoming(llvm::Constant::getNullValue(LTy), BadCastBlock);
+ V = PHI;
+ }
+
+ return V;
+}
Modified: cfe/trunk/lib/CodeGen/CGExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExpr.cpp?rev=88901&r1=88900&r2=88901&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExpr.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExpr.cpp Mon Nov 16 00:50:58 2009
@@ -1290,16 +1290,26 @@
return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
}
-/// EmitCastLValue - Casts are never lvalues. If a cast is needed by the code
-/// generator in an lvalue context, then it must mean that we need the address
-/// of an aggregate in order to access one of its fields. This can happen for
-/// all the reasons that casts are permitted with aggregate result, including
-/// noop aggregate casts, and cast from scalar to union.
+/// EmitCastLValue - Casts are never lvalues unless that cast is a dynamic_cast.
+/// If the cast is a dynamic_cast, we can have the usual lvalue result,
+/// otherwise if a cast is needed by the code generator in an lvalue context,
+/// then it must mean that we need the address of an aggregate in order to
+/// access one of its fields. This can happen for all the reasons that casts
+/// are permitted with aggregate result, including noop aggregate casts, and
+/// cast from scalar to union.
LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
switch (E->getCastKind()) {
default:
return EmitUnsupportedLValue(E, "unexpected cast lvalue");
+ case CastExpr::CK_Dynamic: {
+ LValue LV = EmitLValue(E->getSubExpr());
+ llvm::Value *V = LV.getAddress();
+ const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(E);
+ return LValue::MakeAddr(EmitDynamicCast(V, DCE),
+ MakeQualifiers(E->getType()));
+ }
+
case CastExpr::CK_NoOp:
case CastExpr::CK_ConstructorConversion:
case CastExpr::CK_UserDefinedConversion:
Modified: cfe/trunk/lib/CodeGen/CGExprScalar.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprScalar.cpp?rev=88901&r1=88900&r2=88901&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGExprScalar.cpp (original)
+++ cfe/trunk/lib/CodeGen/CGExprScalar.cpp Mon Nov 16 00:50:58 2009
@@ -852,6 +852,12 @@
Value *Src = Visit(const_cast<Expr*>(E));
return Builder.CreatePtrToInt(Src, ConvertType(DestTy));
}
+
+ case CastExpr::CK_Dynamic: {
+ Value *V = Visit(const_cast<Expr*>(E));
+ const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(CE);
+ return CGF.EmitDynamicCast(V, DCE);
+ }
}
Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.h?rev=88901&r1=88900&r2=88901&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenFunction.h (original)
+++ cfe/trunk/lib/CodeGen/CodeGenFunction.h Mon Nov 16 00:50:58 2009
@@ -664,6 +664,7 @@
void EmitCXXDeleteExpr(const CXXDeleteExpr *E);
llvm::Value* EmitCXXTypeidExpr(const CXXTypeidExpr *E);
+ llvm::Value *EmitDynamicCast(llvm::Value *V, const CXXDynamicCastExpr *DCE);
//===--------------------------------------------------------------------===//
// Declaration Emission
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