[cfe-commits] r127702 - in /cfe/trunk: lib/CodeGen/CGExprConstant.cpp test/CodeGenCXX/member-function-pointers.cpp
Matt Beaumont-Gay
matthewbg at google.com
Wed Mar 16 14:33:34 PDT 2011
Hi John,
'
On Tue, Mar 15, 2011 at 14:17, John McCall <rjmccall at apple.com> wrote:
> Author: rjmccall
> Date: Tue Mar 15 16:17:48 2011
> New Revision: 127702
>
> URL: http://llvm.org/viewvc/llvm-project?rev=127702&view=rev
> Log:
> Reorganize the emission of (unfoldable) constant casts a bit, and
> make sure that upcasts of member pointer types are covered as constants.
> Fixed rdar://problem/9130221
>
>
> Modified:
> cfe/trunk/lib/CodeGen/CGExprConstant.cpp
> cfe/trunk/test/CodeGenCXX/member-function-pointers.cpp
>
> Modified: cfe/trunk/lib/CodeGen/CGExprConstant.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGExprConstant.cpp?rev=127702&r1=127701&r2=127702&view=diff
> ==============================================================================
> --- cfe/trunk/lib/CodeGen/CGExprConstant.cpp (original)
> +++ cfe/trunk/lib/CodeGen/CGExprConstant.cpp Tue Mar 15 16:17:48 2011
> @@ -483,18 +483,17 @@
> }
>
> llvm::Constant *VisitCastExpr(CastExpr* E) {
> + Expr *subExpr = E->getSubExpr();
> + llvm::Constant *C = CGM.EmitConstantExpr(subExpr, subExpr->getType(), CGF);
> + if (!C) return 0;
> +
> + const llvm::Type *destType = ConvertType(E->getType());
> +
> switch (E->getCastKind()) {
> case CK_ToUnion: {
> // GCC cast to union extension
> assert(E->getType()->isUnionType() &&
> "Destination type is not union type!");
> - const llvm::Type *Ty = ConvertType(E->getType());
> - Expr *SubExpr = E->getSubExpr();
> -
> - llvm::Constant *C =
> - CGM.EmitConstantExpr(SubExpr, SubExpr->getType(), CGF);
> - if (!C)
> - return 0;
>
> // Build a struct with the union sub-element as the first member,
> // and padded to the appropriate size
> @@ -503,7 +502,7 @@
> Elts.push_back(C);
> Types.push_back(C->getType());
> unsigned CurSize = CGM.getTargetData().getTypeAllocSize(C->getType());
> - unsigned TotalSize = CGM.getTargetData().getTypeAllocSize(Ty);
> + unsigned TotalSize = CGM.getTargetData().getTypeAllocSize(destType);
>
> assert(CurSize <= TotalSize && "Union size mismatch!");
> if (unsigned NumPadBytes = TotalSize - CurSize) {
> @@ -523,39 +522,101 @@
> const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>();
> return CGM.getCXXABI().EmitNullMemberPointer(MPT);
> }
> -
> - case CK_BaseToDerivedMemberPointer: {
> - Expr *SubExpr = E->getSubExpr();
> - llvm::Constant *C =
> - CGM.EmitConstantExpr(SubExpr, SubExpr->getType(), CGF);
> - if (!C) return 0;
>
> + case CK_DerivedToBaseMemberPointer:
> + case CK_BaseToDerivedMemberPointer:
> return CGM.getCXXABI().EmitMemberPointerConversion(C, E);
> - }
>
> - case CK_BitCast:
> - // This must be a member function pointer cast.
> - return Visit(E->getSubExpr());
> -
> - default: {
> - // FIXME: This should be handled by the CK_NoOp cast kind.
> - // Explicit and implicit no-op casts
> - QualType Ty = E->getType(), SubTy = E->getSubExpr()->getType();
> - if (CGM.getContext().hasSameUnqualifiedType(Ty, SubTy))
> - return Visit(E->getSubExpr());
> -
> - // Handle integer->integer casts for address-of-label differences.
> - if (Ty->isIntegerType() && SubTy->isIntegerType() &&
> - CGF) {
> - llvm::Value *Src = Visit(E->getSubExpr());
> - if (Src == 0) return 0;
> -
> - // Use EmitScalarConversion to perform the conversion.
> - return cast<llvm::Constant>(CGF->EmitScalarConversion(Src, SubTy, Ty));
> - }
> -
> + case CK_LValueToRValue:
> + case CK_NoOp:
> + return C;
> +
> + case CK_AnyPointerToObjCPointerCast:
> + case CK_AnyPointerToBlockPointerCast:
> + case CK_LValueBitCast:
> + case CK_BitCast:
> + if (C->getType() == destType) return C;
> + return llvm::ConstantExpr::getBitCast(C, destType);
> +
> + case CK_Dependent: llvm_unreachable("saw dependent cast!");
> +
> + // These will never be supported.
> + case CK_ObjCObjectLValueCast:
> + case CK_GetObjCProperty:
> + case CK_ToVoid:
> + case CK_Dynamic:
> return 0;
> +
> + // These might need to be supported for constexpr.
> + case CK_UserDefinedConversion:
> + case CK_ConstructorConversion:
> + return 0;
> +
> + // These should eventually be supported.
> + case CK_ArrayToPointerDecay:
> + case CK_FunctionToPointerDecay:
> + case CK_BaseToDerived:
> + case CK_DerivedToBase:
> + case CK_UncheckedDerivedToBase:
> + case CK_MemberPointerToBoolean:
> + case CK_VectorSplat:
> + case CK_FloatingRealToComplex:
> + case CK_FloatingComplexToReal:
> + case CK_FloatingComplexToBoolean:
> + case CK_FloatingComplexCast:
> + case CK_FloatingComplexToIntegralComplex:
> + case CK_IntegralRealToComplex:
> + case CK_IntegralComplexToReal:
> + case CK_IntegralComplexToBoolean:
> + case CK_IntegralComplexCast:
> + case CK_IntegralComplexToFloatingComplex:
> + return 0;
> +
> + case CK_PointerToIntegral:
> + if (!E->getType()->isBooleanType())
> + return llvm::ConstantExpr::getPtrToInt(C, destType);
> + // fallthrough
> +
> + case CK_PointerToBoolean:
> + return llvm::ConstantExpr::getICmp(llvm::CmpInst::ICMP_EQ, C,
> + llvm::ConstantPointerNull::get(cast<llvm::PointerType>(C->getType())));
> +
> + case CK_NullToPointer:
> + return llvm::ConstantPointerNull::get(cast<llvm::PointerType>(destType));
> +
> + case CK_IntegralCast: {
> + bool isSigned = subExpr->getType()->isSignedIntegerType();
> + return llvm::ConstantExpr::getIntegerCast(C, destType, isSigned);
> + }
> +
> + case CK_IntegralToPointer: {
> + bool isSigned = subExpr->getType()->isSignedIntegerType();
> + C = llvm::ConstantExpr::getIntegerCast(C, CGM.IntPtrTy, isSigned);
> + return llvm::ConstantExpr::getIntToPtr(C, destType);
> }
> +
> + case CK_IntegralToBoolean:
> + return llvm::ConstantExpr::getICmp(llvm::CmpInst::ICMP_EQ, C,
> + llvm::Constant::getNullValue(C->getType()));
> +
> + case CK_IntegralToFloating:
> + if (subExpr->getType()->isSignedIntegerType())
> + return llvm::ConstantExpr::getSIToFP(C, destType);
> + else
> + return llvm::ConstantExpr::getUIToFP(C, destType);
> +
> + case CK_FloatingToIntegral:
> + if (E->getType()->isSignedIntegerType())
> + return llvm::ConstantExpr::getFPToSI(C, destType);
> + else
> + return llvm::ConstantExpr::getFPToUI(C, destType);
> +
> + case CK_FloatingToBoolean:
> + return llvm::ConstantExpr::getFCmp(llvm::CmpInst::FCMP_UNE, C,
> + llvm::Constant::getNullValue(C->getType()));
> +
> + case CK_FloatingCast:
> + return llvm::ConstantExpr::getFPCast(C, destType);
> }
> }
Here's the latest salvo in my continuing feud with GCC's -Wreturn-type:
tools/clang/lib/CodeGen/CGExprConstant.cpp: In member function
'llvm::Constant*<unnamed>::ConstExprEmitter::VisitCastExpr(clang::CastExpr*)':
tools/clang/lib/CodeGen/CGExprConstant.cpp:621: error: control reaches
end of non-void function
Is the new llvm_unreachable the right tool here? E.g.:
--- a/lib/CodeGen/CGExprConstant.cpp
+++ b/lib/CodeGen/CGExprConstant.cpp
@@ -618,6 +618,7 @@ public:
case CK_FloatingCast:
return llvm::ConstantExpr::getFPCast(C, destType);
}
+ llvm_unreachable("Invalid CastKind");
}
llvm::Constant *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
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