Author: Utkarsh Saxena Date: 2023-10-23T14:10:06+02:00 New Revision: 9330261143ccbe947ef0687fd20747ba47f26879
URL: https://github.com/llvm/llvm-project/commit/9330261143ccbe947ef0687fd20747ba47f26879 DIFF: https://github.com/llvm/llvm-project/commit/9330261143ccbe947ef0687fd20747ba47f26879.diff LOG: Use the correct namespace for looking up matching operator!= (#68922) `S.getScopeForContext` determins the **active** scope associated with the given `declContext`. This fails to find the matching `operator!=` if candidate `operator==` was found via ADL since that scope is not active. Instead, just directly lookup using the namespace decl of `operator==` Fixes #68901 Added: clang/test/CXX/over/over.match/over.match.funcs/over.match.oper/p2468R2.cppm Modified: clang/docs/ReleaseNotes.rst clang/lib/Sema/SemaOverload.cpp clang/test/CXX/over/over.match/over.match.funcs/over.match.oper/p3-2a.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 39e9b9998aa662c..1315eaffcd4850e 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -85,6 +85,10 @@ C/C++ Language Potentially Breaking Changes ``__has_c_attribute(warn_unused_result)``, 202003, 0 ``__has_c_attribute(gnu::warn_unused_result)``, 202003, 1 +- Fixed a bug in finding matching `operator!=` while adding reversed `operator==` as + outlined in "The Equality Operator You Are Looking For" (`P2468 <http://wg21.link/p2468r2>`_). + Fixes (`#68901: <https://github.com/llvm/llvm-project/issues/68901>`_). + C++ Specific Potentially Breaking Changes ----------------------------------------- - The name mangling rules for function templates has been changed to take into diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp index d9d7ce59b5fcb35..d2475459fa4f4f7 100644 --- a/clang/lib/Sema/SemaOverload.cpp +++ b/clang/lib/Sema/SemaOverload.cpp @@ -962,18 +962,13 @@ static bool shouldAddReversedEqEq(Sema &S, SourceLocation OpLoc, return true; } // Otherwise the search scope is the namespace scope of which F is a member. - LookupResult NonMembers(S, NotEqOp, OpLoc, - Sema::LookupNameKind::LookupOperatorName); - S.LookupName(NonMembers, - S.getScopeForContext(EqFD->getEnclosingNamespaceContext())); - NonMembers.suppressAccessDiagnostics(); - for (NamedDecl *Op : NonMembers) { - auto *FD = Op->getAsFunction(); - if(auto* UD = dyn_cast<UsingShadowDecl>(Op)) - FD = UD->getUnderlyingDecl()->getAsFunction(); - if (FunctionsCorrespond(S.Context, EqFD, FD) && - declaresSameEntity(cast<Decl>(EqFD->getDeclContext()), - cast<Decl>(Op->getDeclContext()))) + for (NamedDecl *Op : EqFD->getEnclosingNamespaceContext()->lookup(NotEqOp)) { + auto *NotEqFD = Op->getAsFunction(); + if (auto *UD = dyn_cast<UsingShadowDecl>(Op)) + NotEqFD = UD->getUnderlyingDecl()->getAsFunction(); + if (FunctionsCorrespond(S.Context, EqFD, NotEqFD) && S.isVisible(NotEqFD) && + declaresSameEntity(cast<Decl>(EqFD->getEnclosingNamespaceContext()), + cast<Decl>(Op->getLexicalDeclContext()))) return false; } return true; diff --git a/clang/test/CXX/over/over.match/over.match.funcs/over.match.oper/p2468R2.cppm b/clang/test/CXX/over/over.match/over.match.funcs/over.match.oper/p2468R2.cppm new file mode 100644 index 000000000000000..05891618991da07 --- /dev/null +++ b/clang/test/CXX/over/over.match/over.match.funcs/over.match.oper/p2468R2.cppm @@ -0,0 +1,24 @@ +// RUN: rm -rf %t +// RUN: mkdir %t +// RUN: split-file %s %t +// +// RUN: %clang_cc1 -std=c++20 %t/A.cppm -emit-module-interface -o %t/A.pcm +// RUN: %clang_cc1 -std=c++20 -fprebuilt-module-path=%t -I%t %t/p2468r2.cpp -verify + +//--- A.cppm +module; +export module A; +export { +namespace NS { +struct S {}; +bool operator==(S, int); +} // namespace NS +} + +namespace NS { bool operator!=(S, int); } // Not visible. + + +//--- p2468r2.cpp +// expected-no-diagnostics +import A; +bool x = 0 == NS::S(); // Ok. operator!= from module A is not visible. diff --git a/clang/test/CXX/over/over.match/over.match.funcs/over.match.oper/p3-2a.cpp b/clang/test/CXX/over/over.match/over.match.funcs/over.match.oper/p3-2a.cpp index 5727d506fe5e61d..016eaf7f52876d5 100644 --- a/clang/test/CXX/over/over.match/over.match.funcs/over.match.oper/p3-2a.cpp +++ b/clang/test/CXX/over/over.match/over.match.funcs/over.match.oper/p3-2a.cpp @@ -374,6 +374,109 @@ bool fine(A a, B b) { return a == b; } // Ok. Found a matching operator!=. } } + +namespace ADL_GH68901{ +namespace test1 { +namespace A { +struct S {}; +bool operator==(S, int); // expected-note {{no known conversion from 'int' to 'S' for 1st argument}} +bool a = 0 == A::S(); // Ok. Operator!= not visible. +bool operator!=(S, int); +} // namespace A +bool a = 0 == A::S(); // expected-error {{invalid operands to binary expression ('int' and 'A::S')}} +} // namespace test1 + +namespace test2 { +namespace B { +struct Derived {}; +struct Base : Derived {}; + +bool operator==(Derived& a, Base& b); +bool operator!=(Derived& a, Base& b); +} // namespace B + +bool foo() { + B::Base a,b; + return a == b; +} +} // namespace test2 + + +namespace template_ { +namespace ns { +template <class T> struct A {}; +template <class T> struct B : A<T> {}; + +template <class T> bool operator==(B<T>, A<T>); // expected-note {{candidate template ignored: could not match 'B' against 'A'}} +template <class T> bool operator!=(B<T>, A<T>); +} + +void test() { + ns::A<int> a; + ns::B<int> b; + a == b; // expected-error {{invalid operands to binary expression}} +} +} // namespace test3 + +namespace using_not_eq { +namespace A { +struct S {}; +namespace B { +bool operator!=(S, int); +} +bool operator==(S, int); // expected-note {{candidate}} +using B::operator!=; +} // namespace A +bool a = 0 == A::S(); // expected-error {{invalid operands to binary expression}} +} // namespace reversed_lookup_not_like_ADL + +namespace using_eqeq { +namespace A { +struct S {}; +namespace B { +bool operator==(S, int); // expected-note {{candidate}} +bool operator!=(S, int); +} +using B::operator==; +} // namespace A +bool a = 0 == A::S(); // expected-error {{invalid operands to binary expression}} +} + +} //namespace ADL_GH68901 + +namespace function_scope_operator_eqeq { +// For non-members, we always lookup for matching operator!= in the namespace scope of +// operator== (and not in the scope of operator==). +struct X { operator int(); }; +namespace test1{ +bool h(X x) { + bool operator==(X, int); // expected-note {{reversed}} + return x == x; // expected-warning {{ambiguous}} +} + +bool g(X x) { + bool operator==(X, int); // expected-note {{reversed}} + bool operator!=(X, int); + return x == x; // expected-warning {{ambiguous}} +} +} // namespace test1 + +namespace test2 { +bool operator!=(X, int); + +bool h(X x) { + bool operator==(X, int); + return x == x; +} + +bool i(X x) { + bool operator==(X, int); + bool operator!=(X, int); + return x == x; +} +} // namespace test2 +} // namespace function_scope_operator_eqeq + namespace non_member_template_2 { struct P {}; template<class S> _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
