[cfe-commits] r97674 - in /cfe/trunk: lib/Sema/Sema.h lib/Sema/SemaExpr.cpp lib/Sema/SemaExprCXX.cpp lib/Sema/SemaInit.cpp lib/Sema/SemaOverload.cpp lib/Sema/TreeTransform.h test/CXX/class.derived/class.member.lookup/p8.cpp
Douglas Gregor
dgregor at apple.com
Wed Mar 3 14:53:40 PST 2010
Author: dgregor
Date: Wed Mar 3 16:53:40 2010
New Revision: 97674
URL: http://llvm.org/viewvc/llvm-project?rev=97674&view=rev
Log:
Implement disambiguation of base class members via a
nested-name-specifier. For example, this allows member access in
diamond-shaped hierarchies like:
struct Base {
void Foo();
int Member;
};
struct D1 : public Base {};
struct D2 : public Base {};
struct Derived : public D1, public D2 { }
void Test(Derived d) {
d.Member = 17; // error: ambiguous cast from Derived to Base
d.D1::Member = 17; // error: okay, modify D1's Base's Member
}
Fixes PR5820 and <rdar://problem/7535045>. Also, eliminate some
redundancy between Sema::PerformObjectMemberConversion() and
Sema::PerformObjectArgumentInitialization() -- the latter now calls
the former.
Added:
cfe/trunk/test/CXX/class.derived/class.member.lookup/p8.cpp
Modified:
cfe/trunk/lib/Sema/Sema.h
cfe/trunk/lib/Sema/SemaExpr.cpp
cfe/trunk/lib/Sema/SemaExprCXX.cpp
cfe/trunk/lib/Sema/SemaInit.cpp
cfe/trunk/lib/Sema/SemaOverload.cpp
cfe/trunk/lib/Sema/TreeTransform.h
Modified: cfe/trunk/lib/Sema/Sema.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/Sema.h?rev=97674&r1=97673&r2=97674&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/Sema.h (original)
+++ cfe/trunk/lib/Sema/Sema.h Wed Mar 3 16:53:40 2010
@@ -1097,12 +1097,16 @@
ImplicitConversionSequence
TryObjectArgumentInitialization(QualType FromType, CXXMethodDecl *Method,
CXXRecordDecl *ActingContext);
- bool PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method);
+ bool PerformObjectArgumentInitialization(Expr *&From,
+ NestedNameSpecifier *Qualifier,
+ CXXMethodDecl *Method);
ImplicitConversionSequence TryContextuallyConvertToBool(Expr *From);
bool PerformContextuallyConvertToBool(Expr *&From);
- bool PerformObjectMemberConversion(Expr *&From, NamedDecl *Member);
+ bool PerformObjectMemberConversion(Expr *&From,
+ NestedNameSpecifier *Qualifier,
+ NamedDecl *Member);
// Members have to be NamespaceDecl* or TranslationUnitDecl*.
// TODO: make this is a typesafe union.
Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=97674&r1=97673&r2=97674&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Wed Mar 3 16:53:40 2010
@@ -635,7 +635,7 @@
MemberType = Context.getQualifiedType(MemberType, NewQuals);
MarkDeclarationReferenced(Loc, *FI);
- PerformObjectMemberConversion(Result, *FI);
+ PerformObjectMemberConversion(Result, /*FIXME:Qualifier=*/0, *FI);
// FIXME: Might this end up being a qualified name?
Result = new (Context) MemberExpr(Result, BaseObjectIsPointer, *FI,
OpLoc, MemberType);
@@ -1357,29 +1357,111 @@
/// \brief Cast member's object to its own class if necessary.
bool
-Sema::PerformObjectMemberConversion(Expr *&From, NamedDecl *Member) {
- if (FieldDecl *FD = dyn_cast<FieldDecl>(Member))
- if (CXXRecordDecl *RD =
- dyn_cast<CXXRecordDecl>(FD->getDeclContext())) {
- QualType DestType =
- Context.getCanonicalType(Context.getTypeDeclType(RD));
- if (DestType->isDependentType() || From->getType()->isDependentType())
- return false;
- QualType FromRecordType = From->getType();
- QualType DestRecordType = DestType;
- if (FromRecordType->getAs<PointerType>()) {
- DestType = Context.getPointerType(DestType);
- FromRecordType = FromRecordType->getPointeeType();
- }
- if (!Context.hasSameUnqualifiedType(FromRecordType, DestRecordType) &&
- CheckDerivedToBaseConversion(FromRecordType,
- DestRecordType,
- From->getSourceRange().getBegin(),
- From->getSourceRange()))
- return true;
- ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase,
- /*isLvalue=*/true);
+Sema::PerformObjectMemberConversion(Expr *&From,
+ NestedNameSpecifier *Qualifier,
+ NamedDecl *Member) {
+ CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Member->getDeclContext());
+ if (!RD)
+ return false;
+
+ QualType DestRecordType;
+ QualType DestType;
+ QualType FromRecordType;
+ QualType FromType = From->getType();
+ bool PointerConversions = false;
+ if (isa<FieldDecl>(Member)) {
+ DestRecordType = Context.getCanonicalType(Context.getTypeDeclType(RD));
+
+ if (FromType->getAs<PointerType>()) {
+ DestType = Context.getPointerType(DestRecordType);
+ FromRecordType = FromType->getPointeeType();
+ PointerConversions = true;
+ } else {
+ DestType = DestRecordType;
+ FromRecordType = FromType;
+ }
+ } else if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Member)) {
+ if (Method->isStatic())
+ return false;
+
+ DestType = Method->getThisType(Context);
+ DestRecordType = DestType->getPointeeType();
+
+ if (FromType->getAs<PointerType>()) {
+ FromRecordType = FromType->getPointeeType();
+ PointerConversions = true;
+ } else {
+ FromRecordType = FromType;
+ DestType = DestRecordType;
+ }
+ } else {
+ // No conversion necessary.
+ return false;
+ }
+
+ if (DestType->isDependentType() || FromType->isDependentType())
+ return false;
+
+ // If the unqualified types are the same, no conversion is necessary.
+ if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType))
+ return false;
+
+ // C++ [class.member.lookup]p8:
+ // [...] Ambiguities can often be resolved by qualifying a name with its
+ // class name.
+ //
+ // If the member was a qualified name and the qualified referred to a
+ // specific base subobject type, we'll cast to that intermediate type
+ // first and then to the object in which the member is declared. That allows
+ // one to resolve ambiguities in, e.g., a diamond-shaped hierarchy such as:
+ //
+ // class Base { public: int x; };
+ // class Derived1 : public Base { };
+ // class Derived2 : public Base { };
+ // class VeryDerived : public Derived1, public Derived2 { void f(); };
+ //
+ // void VeryDerived::f() {
+ // x = 17; // error: ambiguous base subobjects
+ // Derived1::x = 17; // okay, pick the Base subobject of Derived1
+ // }
+ QualType IntermediateRecordType;
+ QualType IntermediateType;
+ if (Qualifier) {
+ if (const RecordType *IntermediateRecord
+ = Qualifier->getAsType()->getAs<RecordType>()) {
+ IntermediateRecordType = QualType(IntermediateRecord, 0);
+ IntermediateType = IntermediateRecordType;
+ if (PointerConversions)
+ IntermediateType = Context.getPointerType(IntermediateType);
}
+ }
+
+ if (!IntermediateType.isNull() &&
+ IsDerivedFrom(FromRecordType, IntermediateRecordType) &&
+ IsDerivedFrom(IntermediateRecordType, DestRecordType)) {
+ if (CheckDerivedToBaseConversion(FromRecordType, IntermediateRecordType,
+ From->getSourceRange().getBegin(),
+ From->getSourceRange()) ||
+ CheckDerivedToBaseConversion(IntermediateRecordType, DestRecordType,
+ From->getSourceRange().getBegin(),
+ From->getSourceRange()))
+ return true;
+
+ ImpCastExprToType(From, IntermediateType, CastExpr::CK_DerivedToBase,
+ /*isLvalue=*/!PointerConversions);
+ ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase,
+ /*isLvalue=*/!PointerConversions);
+ return false;
+ }
+
+ if (CheckDerivedToBaseConversion(FromRecordType,
+ DestRecordType,
+ From->getSourceRange().getBegin(),
+ From->getSourceRange()))
+ return true;
+
+ ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase,
+ /*isLvalue=*/true);
return false;
}
@@ -2666,7 +2748,7 @@
}
MarkDeclarationReferenced(MemberLoc, FD);
- if (PerformObjectMemberConversion(BaseExpr, FD))
+ if (PerformObjectMemberConversion(BaseExpr, Qualifier, FD))
return ExprError();
return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS,
FD, MemberLoc, MemberType));
@@ -6651,7 +6733,7 @@
Res = BuildAnonymousStructUnionMemberReference(
OC.LocEnd, MemberDecl, Res, OC.LocEnd).takeAs<Expr>();
} else {
- PerformObjectMemberConversion(Res, MemberDecl);
+ PerformObjectMemberConversion(Res, /*Qualifier=*/0, MemberDecl);
// MemberDecl->getType() doesn't get the right qualifiers, but it
// doesn't matter here.
Res = new (Context) MemberExpr(Res, false, MemberDecl, OC.LocEnd,
Modified: cfe/trunk/lib/Sema/SemaExprCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExprCXX.cpp?rev=97674&r1=97673&r2=97674&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaExprCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExprCXX.cpp Wed Mar 3 16:53:40 2010
@@ -2881,7 +2881,7 @@
CXXMemberCallExpr *Sema::BuildCXXMemberCallExpr(Expr *Exp,
CXXMethodDecl *Method) {
- if (PerformObjectArgumentInitialization(Exp, Method))
+ if (PerformObjectArgumentInitialization(Exp, /*Qualifier=*/0, Method))
assert(0 && "Calling BuildCXXMemberCallExpr with invalid call?");
MemberExpr *ME =
Modified: cfe/trunk/lib/Sema/SemaInit.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaInit.cpp?rev=97674&r1=97673&r2=97674&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaInit.cpp (original)
+++ cfe/trunk/lib/Sema/SemaInit.cpp Wed Mar 3 16:53:40 2010
@@ -3365,7 +3365,8 @@
// FIXME: Should we move this initialization into a separate
// derived-to-base conversion? I believe the answer is "no", because
// we don't want to turn off access control here for c-style casts.
- if (S.PerformObjectArgumentInitialization(CurInitExpr, Conversion))
+ if (S.PerformObjectArgumentInitialization(CurInitExpr, /*Qualifier=*/0,
+ Conversion))
return S.ExprError();
// Do a little dance to make sure that CurInit has the proper
Modified: cfe/trunk/lib/Sema/SemaOverload.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaOverload.cpp?rev=97674&r1=97673&r2=97674&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaOverload.cpp (original)
+++ cfe/trunk/lib/Sema/SemaOverload.cpp Wed Mar 3 16:53:40 2010
@@ -2304,7 +2304,9 @@
/// the implicit object parameter for the given Method with the given
/// expression.
bool
-Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) {
+Sema::PerformObjectArgumentInitialization(Expr *&From,
+ NestedNameSpecifier *Qualifier,
+ CXXMethodDecl *Method) {
QualType FromRecordType, DestType;
QualType ImplicitParamRecordType =
Method->getThisType(Context)->getAs<PointerType>()->getPointeeType();
@@ -2327,15 +2329,12 @@
diag::err_implicit_object_parameter_init)
<< ImplicitParamRecordType << FromRecordType << From->getSourceRange();
- if (ICS.Standard.Second == ICK_Derived_To_Base &&
- CheckDerivedToBaseConversion(FromRecordType,
- ImplicitParamRecordType,
- From->getSourceRange().getBegin(),
- From->getSourceRange()))
- return true;
+ if (ICS.Standard.Second == ICK_Derived_To_Base)
+ return PerformObjectMemberConversion(From, Qualifier, Method);
- ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase,
- /*isLvalue=*/true);
+ if (!Context.hasSameType(From->getType(), DestType))
+ ImpCastExprToType(From, DestType, CastExpr::CK_NoOp,
+ /*isLvalue=*/!From->getType()->getAs<PointerType>());
return false;
}
@@ -5545,7 +5544,7 @@
if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) {
CheckMemberOperatorAccess(OpLoc, Args[0], Method, Best->getAccess());
- if (PerformObjectArgumentInitialization(Input, Method))
+ if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, Method))
return ExprError();
} else {
// Convert the arguments.
@@ -5738,7 +5737,8 @@
if (Arg1.isInvalid())
return ExprError();
- if (PerformObjectArgumentInitialization(Args[0], Method))
+ if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0,
+ Method))
return ExprError();
Args[1] = RHS = Arg1.takeAs<Expr>();
@@ -5904,7 +5904,8 @@
// Convert the arguments.
CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl);
- if (PerformObjectArgumentInitialization(Args[0], Method))
+ if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0,
+ Method))
return ExprError();
// Convert the arguments.
@@ -6009,12 +6010,15 @@
MemberExpr *MemExpr;
CXXMethodDecl *Method = 0;
+ NestedNameSpecifier *Qualifier = 0;
if (isa<MemberExpr>(NakedMemExpr)) {
MemExpr = cast<MemberExpr>(NakedMemExpr);
Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl());
+ Qualifier = MemExpr->getQualifier();
} else {
UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr);
-
+ Qualifier = UnresExpr->getQualifier();
+
QualType ObjectType = UnresExpr->getBaseType();
// Add overload candidates
@@ -6113,7 +6117,7 @@
// Convert the object argument (for a non-static member function call).
Expr *ObjectArg = MemExpr->getBase();
if (!Method->isStatic() &&
- PerformObjectArgumentInitialization(ObjectArg, Method))
+ PerformObjectArgumentInitialization(ObjectArg, Qualifier, Method))
return ExprError();
MemExpr->setBase(ObjectArg);
@@ -6333,7 +6337,8 @@
bool IsError = false;
// Initialize the implicit object parameter.
- IsError |= PerformObjectArgumentInitialization(Object, Method);
+ IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0,
+ Method);
TheCall->setArg(0, Object);
@@ -6458,7 +6463,7 @@
// Convert the object parameter.
CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function);
- if (PerformObjectArgumentInitialization(Base, Method))
+ if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, Method))
return ExprError();
// No concerns about early exits now.
Modified: cfe/trunk/lib/Sema/TreeTransform.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/TreeTransform.h?rev=97674&r1=97673&r2=97674&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/TreeTransform.h (original)
+++ cfe/trunk/lib/Sema/TreeTransform.h Wed Mar 3 16:53:40 2010
@@ -969,7 +969,7 @@
assert(!Qualifier && "Can't have an unnamed field with a qualifier!");
Expr *BaseExpr = Base.takeAs<Expr>();
- if (getSema().PerformObjectMemberConversion(BaseExpr, Member))
+ if (getSema().PerformObjectMemberConversion(BaseExpr, Qualifier, Member))
return getSema().ExprError();
MemberExpr *ME =
Added: cfe/trunk/test/CXX/class.derived/class.member.lookup/p8.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/class.derived/class.member.lookup/p8.cpp?rev=97674&view=auto
==============================================================================
--- cfe/trunk/test/CXX/class.derived/class.member.lookup/p8.cpp (added)
+++ cfe/trunk/test/CXX/class.derived/class.member.lookup/p8.cpp Wed Mar 3 16:53:40 2010
@@ -0,0 +1,63 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+// FIXME: Access control checks
+
+namespace PR5820 {
+ // also <rdar://problem/7535045>
+ struct Base {
+ void Foo();
+ int Member;
+ };
+
+ struct D1 : public Base {};
+ struct D2 : public Base {};
+
+ struct Derived : public D1, public D2 {
+ void Inner();
+ };
+
+ void Test() {
+ Derived d;
+ d.D1::Foo();
+ d.D1::Member = 17;
+ }
+
+ void Derived::Inner() {
+ D1::Foo();
+ D1::Member = 42;
+ this->D1::Foo();
+ this->D1::Member = 42;
+ }
+}
+
+template<typename T>
+struct BaseT {
+ void Foo(); // expected-note{{found by ambiguous name lookup}}
+ int Member;
+};
+
+template<typename T> struct Derived1T : BaseT<T> { };
+template<typename T> struct Derived2T : BaseT<T> { };
+
+template<typename T>
+struct DerivedT : public Derived1T<T>, public Derived2T<T> {
+ void Inner();
+};
+
+template<typename T>
+void DerivedT<T>::Inner() {
+ Derived1T<T>::Foo();
+ Derived2T<T>::Member = 42;
+ this->Derived1T<T>::Foo();
+ this->Derived2T<T>::Member = 42;
+ this->Foo(); // expected-error{{non-static member 'Foo' found in multiple base-class subobjects of type 'BaseT<int>'}}
+}
+
+template<typename T>
+void Test(DerivedT<T> d) {
+ d.template Derived1T<T>::Foo();
+ d.template Derived2T<T>::Member = 17;
+ d.Inner(); // expected-note{{in instantiation}}
+}
+
+template void Test(DerivedT<int>);
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