[cfe-commits] r124340 - in /cfe/trunk: include/clang/Sema/Sema.h lib/Sema/SemaCXXCast.cpp lib/Sema/SemaExprCXX.cpp lib/Sema/SemaInit.cpp lib/Sema/SemaOverload.cpp lib/Sema/SemaTemplate.cpp test/CXX/expr/expr.cast/p4.cpp
Douglas Gregor
dgregor at apple.com
Wed Jan 26 16:58:17 PST 2011
Author: dgregor
Date: Wed Jan 26 18:58:17 2011
New Revision: 124340
URL: http://llvm.org/viewvc/llvm-project?rev=124340&view=rev
Log:
Fix a horrible bug in our handling of C-style casting, where a C-style
derived-to-base cast that also casts away constness (one of the cases
for static_cast followed by const_cast) would be treated as a bit-cast
rather than a derived-to-base class, causing miscompiles and
heartburn.
Fixes <rdar://problem/8913298>.
Added:
cfe/trunk/test/CXX/expr/expr.cast/p4.cpp
Modified:
cfe/trunk/include/clang/Sema/Sema.h
cfe/trunk/lib/Sema/SemaCXXCast.cpp
cfe/trunk/lib/Sema/SemaExprCXX.cpp
cfe/trunk/lib/Sema/SemaInit.cpp
cfe/trunk/lib/Sema/SemaOverload.cpp
cfe/trunk/lib/Sema/SemaTemplate.cpp
Modified: cfe/trunk/include/clang/Sema/Sema.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Sema/Sema.h?rev=124340&r1=124339&r2=124340&view=diff
==============================================================================
--- cfe/trunk/include/clang/Sema/Sema.h (original)
+++ cfe/trunk/include/clang/Sema/Sema.h Wed Jan 26 18:58:17 2011
@@ -999,7 +999,8 @@
Expr *From,
bool SuppressUserConversions,
bool AllowExplicit,
- bool InOverloadResolution);
+ bool InOverloadResolution,
+ bool CStyle);
bool IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType);
bool IsFloatingPointPromotion(QualType FromType, QualType ToType);
@@ -1023,7 +1024,8 @@
CastKind &Kind,
CXXCastPath &BasePath,
bool IgnoreBaseAccess);
- bool IsQualificationConversion(QualType FromType, QualType ToType);
+ bool IsQualificationConversion(QualType FromType, QualType ToType,
+ bool CStyle);
bool DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType);
@@ -4559,10 +4561,11 @@
bool PerformImplicitConversion(Expr *&From, QualType ToType,
const ImplicitConversionSequence& ICS,
AssignmentAction Action,
- bool IgnoreBaseAccess = false);
+ bool CStyle = false);
bool PerformImplicitConversion(Expr *&From, QualType ToType,
const StandardConversionSequence& SCS,
- AssignmentAction Action,bool IgnoreBaseAccess);
+ AssignmentAction Action,
+ bool CStyle);
/// the following "Check" methods will return a valid/converted QualType
/// or a null QualType (indicating an error diagnostic was issued).
Modified: cfe/trunk/lib/Sema/SemaCXXCast.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaCXXCast.cpp?rev=124340&r1=124339&r2=124340&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaCXXCast.cpp (original)
+++ cfe/trunk/lib/Sema/SemaCXXCast.cpp Wed Jan 26 18:58:17 2011
@@ -320,7 +320,7 @@
// Test if they're compatible.
return SrcConstruct != DestConstruct &&
- !Self.IsQualificationConversion(SrcConstruct, DestConstruct);
+ !Self.IsQualificationConversion(SrcConstruct, DestConstruct, false);
}
/// CheckDynamicCast - Check that a dynamic_cast\<DestType\>(SrcExpr) is valid.
@@ -1035,8 +1035,7 @@
InitializedEntity Entity = InitializedEntity::InitializeTemporary(DestType);
InitializationKind InitKind
- = InitializationKind::CreateCast(/*FIXME:*/OpRange,
- CStyle);
+ = InitializationKind::CreateCast(/*FIXME:*/OpRange, CStyle);
InitializationSequence InitSeq(Self, Entity, InitKind, &SrcExpr, 1);
// At this point of CheckStaticCast, if the destination is a reference,
Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=124340&r1=124339&r2=124340&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Wed Jan 26 18:58:17 2011
@@ -1737,11 +1737,11 @@
bool
Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
const ImplicitConversionSequence &ICS,
- AssignmentAction Action, bool IgnoreBaseAccess) {
+ AssignmentAction Action, bool CStyle) {
switch (ICS.getKind()) {
case ImplicitConversionSequence::StandardConversion:
if (PerformImplicitConversion(From, ToType, ICS.Standard, Action,
- IgnoreBaseAccess))
+ CStyle))
return true;
break;
@@ -1772,7 +1772,7 @@
if (!ICS.UserDefined.EllipsisConversion) {
if (PerformImplicitConversion(From, BeforeToType,
ICS.UserDefined.Before, AA_Converting,
- IgnoreBaseAccess))
+ CStyle))
return true;
}
@@ -1790,7 +1790,7 @@
From = CastArg.takeAs<Expr>();
return PerformImplicitConversion(From, ToType, ICS.UserDefined.After,
- AA_Converting, IgnoreBaseAccess);
+ AA_Converting, CStyle);
}
case ImplicitConversionSequence::AmbiguousConversion:
@@ -1820,7 +1820,7 @@
bool
Sema::PerformImplicitConversion(Expr *&From, QualType ToType,
const StandardConversionSequence& SCS,
- AssignmentAction Action, bool IgnoreBaseAccess) {
+ AssignmentAction Action, bool CStyle) {
// Overall FIXME: we are recomputing too many types here and doing far too
// much extra work. What this means is that we need to keep track of more
// information that is computed when we try the implicit conversion initially,
@@ -1982,7 +1982,7 @@
CastKind Kind = CK_Invalid;
CXXCastPath BasePath;
- if (CheckPointerConversion(From, ToType, Kind, BasePath, IgnoreBaseAccess))
+ if (CheckPointerConversion(From, ToType, Kind, BasePath, CStyle))
return true;
ImpCastExprToType(From, ToType, Kind, VK_RValue, &BasePath);
break;
@@ -1991,8 +1991,7 @@
case ICK_Pointer_Member: {
CastKind Kind = CK_Invalid;
CXXCastPath BasePath;
- if (CheckMemberPointerConversion(From, ToType, Kind, BasePath,
- IgnoreBaseAccess))
+ if (CheckMemberPointerConversion(From, ToType, Kind, BasePath, CStyle))
return true;
if (CheckExceptionSpecCompatibility(From, ToType))
return true;
@@ -2022,7 +2021,7 @@
From->getLocStart(),
From->getSourceRange(),
&BasePath,
- IgnoreBaseAccess))
+ CStyle))
return true;
ImpCastExprToType(From, ToType.getNonReferenceType(),
Modified: cfe/trunk/lib/Sema/SemaInit.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaInit.cpp?rev=124340&r1=124339&r2=124340&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaInit.cpp (original)
+++ cfe/trunk/lib/Sema/SemaInit.cpp Wed Jan 26 18:58:17 2011
@@ -2519,7 +2519,9 @@
bool T1Function = T1->isFunctionType();
if (isLValueRef || T1Function) {
if (InitCategory.isLValue() &&
- RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) {
+ (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification ||
+ (Kind.isCStyleOrFunctionalCast() &&
+ RefRelationship == Sema::Ref_Related))) {
// - is an lvalue (but is not a bit-field), and "cv1 T1" is
// reference-compatible with "cv2 T2," or
//
@@ -2593,7 +2595,9 @@
// "cv1 T1" is reference-compatible with "cv2 T2"
// Note: functions are handled below.
if (!T1Function &&
- RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification &&
+ (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification ||
+ (Kind.isCStyleOrFunctionalCast() &&
+ RefRelationship == Sema::Ref_Related)) &&
(InitCategory.isXValue() ||
(InitCategory.isPRValue() && T2->isRecordType()) ||
(InitCategory.isPRValue() && T2->isArrayType()))) {
@@ -2630,9 +2634,6 @@
// reference-related to T2, and can be implicitly converted to an
// xvalue, class prvalue, or function lvalue of type "cv3 T3",
// where "cv1 T1" is reference-compatible with "cv3 T3",
- //
- // FIXME: Need to handle xvalue, class prvalue, etc. cases in
- // TryRefInitWithConversionFunction.
if (T2->isRecordType()) {
if (RefRelationship == Sema::Ref_Incompatible) {
ConvOvlResult = TryRefInitWithConversionFunction(S, Entity,
@@ -2665,7 +2666,8 @@
if (S.TryImplicitConversion(Sequence, TempEntity, Initializer,
/*SuppressUserConversions*/ false,
AllowExplicit,
- /*FIXME:InOverloadResolution=*/false)) {
+ /*FIXME:InOverloadResolution=*/false,
+ /*CStyle=*/Kind.isCStyleOrFunctionalCast())) {
// FIXME: Use the conversion function set stored in ICS to turn
// this into an overloading ambiguity diagnostic. However, we need
// to keep that set as an OverloadCandidateSet rather than as some
@@ -3184,7 +3186,8 @@
if (S.TryImplicitConversion(*this, Entity, Initializer,
/*SuppressUserConversions*/ true,
/*AllowExplicitConversions*/ false,
- /*InOverloadResolution*/ false))
+ /*InOverloadResolution*/ false,
+ /*CStyle=*/Kind.isCStyleOrFunctionalCast()))
{
if (Initializer->getType() == Context.OverloadTy)
SetFailed(InitializationSequence::FK_AddressOfOverloadFailed);
@@ -3844,11 +3847,9 @@
}
case SK_ConversionSequence: {
- bool IgnoreBaseAccess = Kind.isCStyleOrFunctionalCast();
-
if (S.PerformImplicitConversion(CurInitExpr, Step->Type, *Step->ICS,
getAssignmentAction(Entity),
- IgnoreBaseAccess))
+ Kind.isCStyleOrFunctionalCast()))
return ExprError();
CurInit.release();
Modified: cfe/trunk/lib/Sema/SemaOverload.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaOverload.cpp?rev=124340&r1=124339&r2=124340&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaOverload.cpp (original)
+++ cfe/trunk/lib/Sema/SemaOverload.cpp Wed Jan 26 18:58:17 2011
@@ -46,7 +46,8 @@
static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
bool InOverloadResolution,
- StandardConversionSequence &SCS);
+ StandardConversionSequence &SCS,
+ bool CStyle);
static OverloadingResult
IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType,
UserDefinedConversionSequence& User,
@@ -744,10 +745,11 @@
TryImplicitConversion(Sema &S, Expr *From, QualType ToType,
bool SuppressUserConversions,
bool AllowExplicit,
- bool InOverloadResolution) {
+ bool InOverloadResolution,
+ bool CStyle) {
ImplicitConversionSequence ICS;
if (IsStandardConversion(S, From, ToType, InOverloadResolution,
- ICS.Standard)) {
+ ICS.Standard, CStyle)) {
ICS.setStandard();
return ICS;
}
@@ -858,12 +860,14 @@
Expr *Initializer,
bool SuppressUserConversions,
bool AllowExplicitConversions,
- bool InOverloadResolution) {
+ bool InOverloadResolution,
+ bool CStyle) {
ImplicitConversionSequence ICS
= clang::TryImplicitConversion(*this, Initializer, Entity.getType(),
SuppressUserConversions,
AllowExplicitConversions,
- InOverloadResolution);
+ InOverloadResolution,
+ CStyle);
if (ICS.isBad()) return true;
// Perform the actual conversion.
@@ -891,7 +895,8 @@
ICS = clang::TryImplicitConversion(*this, From, ToType,
/*SuppressUserConversions=*/false,
AllowExplicit,
- /*InOverloadResolution=*/false);
+ /*InOverloadResolution=*/false,
+ /*CStyle=*/false);
return PerformImplicitConversion(From, ToType, ICS, Action);
}
@@ -999,7 +1004,8 @@
/// routine will return false and the value of SCS is unspecified.
static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType,
bool InOverloadResolution,
- StandardConversionSequence &SCS) {
+ StandardConversionSequence &SCS,
+ bool CStyle) {
QualType FromType = From->getType();
// Standard conversions (C++ [conv])
@@ -1189,7 +1195,7 @@
QualType CanonFrom;
QualType CanonTo;
// The third conversion can be a qualification conversion (C++ 4p1).
- if (S.IsQualificationConversion(FromType, ToType)) {
+ if (S.IsQualificationConversion(FromType, ToType, CStyle)) {
SCS.Third = ICK_Qualification;
FromType = ToType;
CanonFrom = S.Context.getCanonicalType(FromType);
@@ -1984,7 +1990,8 @@
/// an rvalue of type FromType to ToType is a qualification conversion
/// (C++ 4.4).
bool
-Sema::IsQualificationConversion(QualType FromType, QualType ToType) {
+Sema::IsQualificationConversion(QualType FromType, QualType ToType,
+ bool CStyle) {
FromType = Context.getCanonicalType(FromType);
ToType = Context.getCanonicalType(ToType);
@@ -2009,12 +2016,12 @@
// -- for every j > 0, if const is in cv 1,j then const is in cv
// 2,j, and similarly for volatile.
- if (!ToType.isAtLeastAsQualifiedAs(FromType))
+ if (!CStyle && !ToType.isAtLeastAsQualifiedAs(FromType))
return false;
// -- if the cv 1,j and cv 2,j are different, then const is in
// every cv for 0 < k < j.
- if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers()
+ if (!CStyle && FromType.getCVRQualifiers() != ToType.getCVRQualifiers()
&& !PreviousToQualsIncludeConst)
return false;
@@ -3156,7 +3163,8 @@
// and does not constitute a conversion.
ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions,
/*AllowExplicit=*/false,
- /*InOverloadResolution=*/false);
+ /*InOverloadResolution=*/false,
+ /*CStyle=*/false);
// Of course, that's still a reference binding.
if (ICS.isStandard()) {
@@ -3195,7 +3203,8 @@
return TryImplicitConversion(S, From, ToType,
SuppressUserConversions,
/*AllowExplicit=*/false,
- InOverloadResolution);
+ InOverloadResolution,
+ /*CStyle=*/false);
}
/// TryObjectArgumentInitialization - Try to initialize the object
@@ -3379,7 +3388,8 @@
// FIXME: Are these flags correct?
/*SuppressUserConversions=*/false,
/*AllowExplicit=*/true,
- /*InOverloadResolution=*/false);
+ /*InOverloadResolution=*/false,
+ /*CStyle=*/false);
}
/// PerformContextuallyConvertToBool - Perform a contextual conversion
@@ -3405,7 +3415,8 @@
// FIXME: Are these flags correct?
/*SuppressUserConversions=*/false,
/*AllowExplicit=*/true,
- /*InOverloadResolution=*/false);
+ /*InOverloadResolution=*/false,
+ /*CStyle=*/false);
}
/// PerformContextuallyConvertToObjCId - Perform a contextual conversion
Modified: cfe/trunk/lib/Sema/SemaTemplate.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplate.cpp?rev=124340&r1=124339&r2=124340&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaTemplate.cpp (original)
+++ cfe/trunk/lib/Sema/SemaTemplate.cpp Wed Jan 26 18:58:17 2011
@@ -3085,7 +3085,7 @@
if (ParamType->isPointerType() &&
!ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType() &&
- S.IsQualificationConversion(ArgType, ParamType)) {
+ S.IsQualificationConversion(ArgType, ParamType, false)) {
// For pointer-to-object types, qualification conversions are
// permitted.
} else {
@@ -3429,7 +3429,8 @@
ParamType,
Arg, Converted);
- if (IsQualificationConversion(ArgType, ParamType.getNonReferenceType())) {
+ if (IsQualificationConversion(ArgType, ParamType.getNonReferenceType(),
+ false)) {
ImpCastExprToType(Arg, ParamType, CK_NoOp, CastCategory(Arg));
} else if (!Context.hasSameUnqualifiedType(ArgType,
ParamType.getNonReferenceType())) {
@@ -3492,7 +3493,7 @@
if (Context.hasSameUnqualifiedType(ParamType, ArgType)) {
// Types match exactly: nothing more to do here.
- } else if (IsQualificationConversion(ArgType, ParamType)) {
+ } else if (IsQualificationConversion(ArgType, ParamType, false)) {
ImpCastExprToType(Arg, ParamType, CK_NoOp, CastCategory(Arg));
} else {
// We can't perform this conversion.
@@ -3597,7 +3598,7 @@
// the element type on the parameter could be more qualified than the
// element type in the expression we constructed.
if (IsQualificationConversion(((Expr*) RefExpr.get())->getType(),
- ParamType.getUnqualifiedType())) {
+ ParamType.getUnqualifiedType(), false)) {
Expr *RefE = RefExpr.takeAs<Expr>();
ImpCastExprToType(RefE, ParamType.getUnqualifiedType(), CK_NoOp);
RefExpr = Owned(RefE);
Added: cfe/trunk/test/CXX/expr/expr.cast/p4.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/expr/expr.cast/p4.cpp?rev=124340&view=auto
==============================================================================
--- cfe/trunk/test/CXX/expr/expr.cast/p4.cpp (added)
+++ cfe/trunk/test/CXX/expr/expr.cast/p4.cpp Wed Jan 26 18:58:17 2011
@@ -0,0 +1,23 @@
+// RUN: %clang_cc1 -ast-dump %s | FileCheck %s
+
+struct A { int x; };
+struct B { int y; };
+struct C : A, B { };
+
+// CHECK: casting_away_constness
+void casting_away_constness(const B &b, const C &c, const B *bp, const C *cp) {
+ // CHECK: DerivedToBase (B)
+ // CHECK: DeclRefExpr {{.*}} ParmVar='c'
+ (void)(B&)c;
+ // CHECK: BaseToDerived (B)
+ // CHECK: DeclRefExpr {{.*}} ParmVar='b'
+ (void)(C&)b;
+ // CHECK: DerivedToBase (B)
+ // CHECK: DeclRefExpr {{.*}} ParmVar='cp'
+ (void)(B*)cp;
+ // CHECK: BaseToDerived (B)
+ // CHECK: DeclRefExpr {{.*}} ParmVar='bp'
+ (void)(C*)bp;
+ // CHECK: ReturnStmt
+ return;
+}
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