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Introduce a null-to-pointer implicit cast kind.

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llvm-svn: 118966
This commit is contained in:
John McCall 2010-11-13 01:35:44 +00:00
parent 1aa5863a3e
commit e84af4e486
11 changed files with 59 additions and 20 deletions
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1
clang/include/clang/AST/Expr.h
View File

@ -1982,6 +1982,7 @@ private:
case CK_ArrayToPointerDecay:
case CK_FunctionToPointerDecay:
case CK_NullToMemberPointer:
case CK_NullToPointer:
case CK_UserDefinedConversion:
case CK_ConstructorConversion:
case CK_IntegralToPointer:

3
clang/include/clang/AST/OperationKinds.h
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@ -57,6 +57,9 @@ enum CastKind {
/// CK_FunctionToPointerDecay - Function to pointer decay.
CK_FunctionToPointerDecay,
/// CK_NullToPointer - Null pointer to pointer.
CK_NullToPointer,
/// CK_NullToMemberPointer - Null pointer to member pointer.
CK_NullToMemberPointer,

2
clang/lib/AST/Expr.cpp
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@ -764,6 +764,8 @@ const char *CastExpr::getCastKindName() const {
return "FunctionToPointerDecay";
case CK_NullToMemberPointer:
return "NullToMemberPointer";
case CK_NullToPointer:
return "NullToPointer";
case CK_BaseToDerivedMemberPointer:
return "BaseToDerivedMemberPointer";
case CK_DerivedToBaseMemberPointer:

6
clang/lib/AST/ExprConstant.cpp
View File

@ -604,6 +604,12 @@ bool PointerExprEvaluator::VisitCastExpr(CastExpr* E) {
return true;
}
case CK_NullToPointer: {
Result.Base = 0;
Result.Offset = CharUnits::Zero();
return true;
}
case CK_IntegralToPointer: {
APValue Value;
if (!EvaluateIntegerOrLValue(SubExpr, Value, Info))

1
clang/lib/Checker/GRExprEngine.cpp
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@ -2518,6 +2518,7 @@ void GRExprEngine::VisitCast(const CastExpr *CastE, const Expr *Ex,
case CK_BitCast:
case CK_LValueBitCast:
case CK_IntegralCast:
case CK_NullToPointer:
case CK_IntegralToPointer:
case CK_PointerToIntegral:
case CK_IntegralToFloating:

1
clang/lib/CodeGen/CGExpr.cpp
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@ -1806,6 +1806,7 @@ LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
case CK_ArrayToPointerDecay:
case CK_FunctionToPointerDecay:
case CK_NullToMemberPointer:
case CK_NullToPointer:
case CK_IntegralToPointer:
case CK_PointerToIntegral:
case CK_VectorSplat:

18
clang/lib/CodeGen/CGExprScalar.cpp
View File

@ -48,6 +48,13 @@ struct BinOpInfo {
const Expr *E; // Entire expr, for error unsupported. May not be binop.
};
static bool MustVisitNullValue(const Expr *E) {
// If a null pointer expression's type is the C++0x nullptr_t, then
// it's not necessarily a simple constant and it must be evaluated
// for its potential side effects.
return E->getType()->isNullPtrType();
}
class ScalarExprEmitter
: public StmtVisitor<ScalarExprEmitter, Value*> {
CodeGenFunction &CGF;
@ -1044,10 +1051,15 @@ Value *ScalarExprEmitter::EmitCastExpr(CastExpr *CE) {
case CK_FunctionToPointerDecay:
return EmitLValue(E).getAddress();
case CK_NullToPointer:
if (MustVisitNullValue(E))
(void) Visit(E);
return llvm::ConstantPointerNull::get(
cast<llvm::PointerType>(ConvertType(DestTy)));
case CK_NullToMemberPointer: {
// If the subexpression's type is the C++0x nullptr_t, emit the
// subexpression, which may have side effects.
if (E->getType()->isNullPtrType())
if (MustVisitNullValue(E))
(void) Visit(E);
const MemberPointerType *MPT = CE->getType()->getAs<MemberPointerType>();

4
clang/lib/Sema/SemaCXXCast.cpp
View File

@ -1131,7 +1131,7 @@ static TryCastResult TryReinterpretCast(Sema &Self, Expr *SrcExpr,
// Is the source an overloaded name? (i.e. &foo)
// If so, reinterpret_cast can not help us here (13.4, p1, bullet 5)
if (SrcType == Self.Context.OverloadTy )
if (SrcType == Self.Context.OverloadTy)
return TC_NotApplicable;
if (const ReferenceType *DestTypeTmp = DestType->getAs<ReferenceType>()) {
@ -1270,6 +1270,8 @@ static TryCastResult TryReinterpretCast(Sema &Self, Expr *SrcExpr,
assert(destIsPtr && "One type must be a pointer");
// C++ 5.2.10p5: A value of integral or enumeration type can be explicitly
// converted to a pointer.
// C++ 5.2.10p9: [Note: ...a null pointer constant of integral type is not
// necessarily converted to a null pointer value.]
Kind = CK_IntegralToPointer;
return TC_Success;
}

31
clang/lib/Sema/SemaExpr.cpp
View File

@ -4003,7 +4003,8 @@ Sema::ActOnInitList(SourceLocation LBraceLoc, MultiExprArg initlist,
}
static CastKind getScalarCastKind(ASTContext &Context,
QualType SrcTy, QualType DestTy) {
Expr *Src, QualType DestTy) {
QualType SrcTy = Src->getType();
if (Context.hasSameUnqualifiedType(SrcTy, DestTy))
return CK_NoOp;
@ -4019,8 +4020,11 @@ static CastKind getScalarCastKind(ASTContext &Context,
if (SrcTy->isIntegerType()) {
if (DestTy->isIntegerType())
return CK_IntegralCast;
if (DestTy->hasPointerRepresentation())
if (DestTy->hasPointerRepresentation()) {
if (Src->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
return CK_NullToPointer;
return CK_IntegralToPointer;
}
if (DestTy->isRealFloatingType())
return CK_IntegralToFloating;
}
@ -4131,7 +4135,7 @@ bool Sema::CheckCastTypes(SourceRange TyR, QualType castType, Expr *&castExpr,
<< castType << castExpr->getSourceRange();
}
Kind = getScalarCastKind(Context, castExpr->getType(), castType);
Kind = getScalarCastKind(Context, castExpr, castType);
if (Kind == CK_Unknown || Kind == CK_BitCast)
CheckCastAlign(castExpr, castType, TyR);
@ -4185,7 +4189,7 @@ bool Sema::CheckExtVectorCast(SourceRange R, QualType DestTy, Expr *&CastExpr,
QualType DestElemTy = DestTy->getAs<ExtVectorType>()->getElementType();
ImpCastExprToType(CastExpr, DestElemTy,
getScalarCastKind(Context, SrcTy, DestElemTy));
getScalarCastKind(Context, CastExpr, DestElemTy));
Kind = CK_VectorSplat;
return false;
@ -4533,7 +4537,8 @@ QualType Sema::CheckConditionalOperands(Expr *&Cond, Expr *&LHS, Expr *&RHS,
return LHSTy;
}
// GCC compatibility: soften pointer/integer mismatch.
// GCC compatibility: soften pointer/integer mismatch. Note that
// null pointers have been filtered out by this point.
if (RHSTy->isPointerType() && LHSTy->isIntegerType()) {
Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch)
<< LHSTy << RHSTy << LHS->getSourceRange() << RHS->getSourceRange();
@ -5104,7 +5109,7 @@ Sema::CheckTransparentUnionArgumentConstraints(QualType ArgType, Expr *&rExpr) {
if (rExpr->isNullPointerConstant(Context,
Expr::NPC_ValueDependentIsNull)) {
ImpCastExprToType(rExpr, it->getType(), CK_IntegralToPointer);
ImpCastExprToType(rExpr, it->getType(), CK_NullToPointer);
InitField = *it;
break;
}
@ -5827,7 +5832,7 @@ QualType Sema::CheckCompareOperands(Expr *&lex, Expr *&rex, SourceLocation Loc,
ImpCastExprToType(rex, lType,
lType->isMemberPointerType()
? CK_NullToMemberPointer
: CK_IntegralToPointer);
: CK_NullToPointer);
return ResultTy;
}
if (LHSIsNull &&
@ -5836,7 +5841,7 @@ QualType Sema::CheckCompareOperands(Expr *&lex, Expr *&rex, SourceLocation Loc,
ImpCastExprToType(lex, rType,
rType->isMemberPointerType()
? CK_NullToMemberPointer
: CK_IntegralToPointer);
: CK_NullToPointer);
return ResultTy;
}
@ -5951,21 +5956,23 @@ QualType Sema::CheckCompareOperands(Expr *&lex, Expr *&rex, SourceLocation Loc,
}
if (lType->isIntegerType())
ImpCastExprToType(lex, rType, CK_IntegralToPointer);
ImpCastExprToType(lex, rType,
LHSIsNull ? CK_NullToPointer : CK_IntegralToPointer);
else
ImpCastExprToType(rex, lType, CK_IntegralToPointer);
ImpCastExprToType(rex, lType,
RHSIsNull ? CK_NullToPointer : CK_IntegralToPointer);
return ResultTy;
}
// Handle block pointers.
if (!isRelational && RHSIsNull
&& lType->isBlockPointerType() && rType->isIntegerType()) {
ImpCastExprToType(rex, lType, CK_IntegralToPointer);
ImpCastExprToType(rex, lType, CK_NullToPointer);
return ResultTy;
}
if (!isRelational && LHSIsNull
&& lType->isIntegerType() && rType->isBlockPointerType()) {
ImpCastExprToType(lex, rType, CK_IntegralToPointer);
ImpCastExprToType(lex, rType, CK_NullToPointer);
return ResultTy;
}
return InvalidOperands(Loc, lex, rex);

4
clang/lib/Sema/SemaExprCXX.cpp
View File

@ -2750,14 +2750,14 @@ QualType Sema::FindCompositePointerType(SourceLocation Loc,
if (T2->isMemberPointerType())
ImpCastExprToType(E1, T2, CK_NullToMemberPointer);
else
ImpCastExprToType(E1, T2, CK_IntegralToPointer);
ImpCastExprToType(E1, T2, CK_NullToPointer);
return T2;
}
if (E2->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) {
if (T1->isMemberPointerType())
ImpCastExprToType(E2, T1, CK_NullToMemberPointer);
else
ImpCastExprToType(E2, T1, CK_IntegralToPointer);
ImpCastExprToType(E2, T1, CK_NullToPointer);
return T1;
}

8
clang/lib/Sema/SemaExprObjC.cpp
View File

@ -1014,9 +1014,13 @@ ExprResult Sema::BuildInstanceMessage(Expr *Receiver,
if (ReceiverType->isPointerType())
ImpCastExprToType(Receiver, Context.getObjCIdType(),
CK_BitCast);
else
else {
// TODO: specialized warning on null receivers?
bool IsNull = Receiver->isNullPointerConstant(Context,
Expr::NPC_ValueDependentIsNull);
ImpCastExprToType(Receiver, Context.getObjCIdType(),
CK_IntegralToPointer);
IsNull ? CK_NullToPointer : CK_IntegralToPointer);
}
ReceiverType = Receiver->getType();
}
else if (getLangOptions().CPlusPlus &&