llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Younan Zhang (zyn0217) <details> <summary>Changes</summary> `FindInstantiatedDecl()` relies on the `CurContext` to find the corresponding class template instantiation for a class template declaration. Previously, we pushed the semantic declaration context for constraint comparison, which is incorrect for constraints on friend declarations. In issue #<!-- -->78101, the semantic context of the friend is the TU, so we missed the implicit template specialization `Template<void, 4>` when looking for the instantiation of the primary template `Template` at the time of checking the member instantiation; instead, we mistakenly picked up the explicit specialization `Template<float, 5>`, hence the error. As a bonus, this also fixes a crash when diagnosing constraints. The DeclarationName is not necessarily an identifier, so it's incorrect to call `getName()` on e.g. overloaded operators. Since the DiagnosticBuilder has correctly handled Decl printing, we don't need to find the printable name ourselves. Fixes https://github.com/llvm/llvm-project/issues/78101 --- Full diff: https://github.com/llvm/llvm-project/pull/106890.diff 6 Files Affected: - (modified) clang/docs/ReleaseNotes.rst (+1) - (modified) clang/include/clang/Basic/DiagnosticSemaKinds.td (+1-1) - (modified) clang/lib/Sema/SemaConcept.cpp (+4-1) - (modified) clang/lib/Sema/SemaTemplateInstantiate.cpp (+1-2) - (modified) clang/test/CXX/temp/temp.constr/temp.constr.normal/p1.cpp (+1-1) - (modified) clang/test/SemaTemplate/concepts-friends.cpp (+23) ``````````diff diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 98fb0174d4a37e..fc940db4813948 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -338,6 +338,7 @@ Bug Fixes to C++ Support - Fixed an assertion failure when converting vectors to int/float with invalid expressions. (#GH105486) - Template parameter names are considered in the name lookup of out-of-line class template specialization right before its declaration context. (#GH64082) +- Fixed a constraint comparison bug for friend declarations. (#GH78101) Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td index 66f8890da75e5d..dcb49d8a67604a 100644 --- a/clang/include/clang/Basic/DiagnosticSemaKinds.td +++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td @@ -5603,7 +5603,7 @@ def note_checking_constraints_for_function_here : Note< def note_constraint_substitution_here : Note< "while substituting template arguments into constraint expression here">; def note_constraint_normalization_here : Note< - "while calculating associated constraint of template '%0' here">; + "while calculating associated constraint of template %0 here">; def note_parameter_mapping_substitution_here : Note< "while substituting into concept arguments here; substitution failures not " "allowed in concept arguments">; diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp index 86d6f308a51cc2..afbfe278680240 100644 --- a/clang/lib/Sema/SemaConcept.cpp +++ b/clang/lib/Sema/SemaConcept.cpp @@ -1012,7 +1012,10 @@ static const Expr *SubstituteConstraintExpressionWithoutSatisfaction( // possible that e.g. constraints involving C<Class<T>> and C<Class> are // perceived identical. std::optional<Sema::ContextRAII> ContextScope; - if (auto *RD = dyn_cast<CXXRecordDecl>(DeclInfo.getDeclContext())) { + if (auto *RD = + dyn_cast<CXXRecordDecl>(DeclInfo.getDecl()->getFriendObjectKind() + ? DeclInfo.getLexicalDeclContext() + : DeclInfo.getDeclContext())) { ThisScope.emplace(S, const_cast<CXXRecordDecl *>(RD), Qualifiers()); ContextScope.emplace(S, const_cast<DeclContext *>(cast<DeclContext>(RD)), /*NewThisContext=*/false); diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp index 776297479e141e..c42cc250bb904a 100644 --- a/clang/lib/Sema/SemaTemplateInstantiate.cpp +++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp @@ -1226,8 +1226,7 @@ void Sema::PrintInstantiationStack() { case CodeSynthesisContext::ConstraintNormalization: Diags.Report(Active->PointOfInstantiation, diag::note_constraint_normalization_here) - << cast<NamedDecl>(Active->Entity)->getName() - << Active->InstantiationRange; + << cast<NamedDecl>(Active->Entity) << Active->InstantiationRange; break; case CodeSynthesisContext::ParameterMappingSubstitution: Diags.Report(Active->PointOfInstantiation, diff --git a/clang/test/CXX/temp/temp.constr/temp.constr.normal/p1.cpp b/clang/test/CXX/temp/temp.constr/temp.constr.normal/p1.cpp index d80710937cdfa1..3992835c444027 100644 --- a/clang/test/CXX/temp/temp.constr/temp.constr.normal/p1.cpp +++ b/clang/test/CXX/temp/temp.constr/temp.constr.normal/p1.cpp @@ -15,7 +15,7 @@ template<typename T> requires Bar2<T> struct S2 { }; // expected-note@-1{{template is declared here}} template<typename T> requires Bar2<T> && true struct S2<T> { }; // expected-error@-1{{class template partial specialization is not more specialized than the primary template}} -// expected-note@-2{{while calculating associated constraint of template 'S2' here}} +// expected-note@-2{{while calculating associated constraint of template 'S2<T>' here}} namespace type_pack { template<typename... Args> diff --git a/clang/test/SemaTemplate/concepts-friends.cpp b/clang/test/SemaTemplate/concepts-friends.cpp index 14b37d78d951dc..d05be423a8cfcd 100644 --- a/clang/test/SemaTemplate/concepts-friends.cpp +++ b/clang/test/SemaTemplate/concepts-friends.cpp @@ -525,3 +525,26 @@ struct S { }; } + +namespace GH78101 { + +template <typename T, int i> +concept True = true; + +template <typename T, int I> struct Template { + static constexpr int i = I; + + friend constexpr auto operator+(True<i> auto f) { return i; } +}; + +template <int I> struct Template<float, I> { + static constexpr int i = I; + + friend constexpr auto operator+(True<i> auto f) { return i; } +}; + +Template<void, 4> f{}; + +static_assert(+Template<float, 5>{} == 5); + +} // namespace GH78101 `````````` </details> https://github.com/llvm/llvm-project/pull/106890 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
