Author: Younan Zhang Date: 2026-01-09T16:33:59+08:00 New Revision: 35e540d7801ac8e229fac8ef418ee81414f2f249
URL: https://github.com/llvm/llvm-project/commit/35e540d7801ac8e229fac8ef418ee81414f2f249 DIFF: https://github.com/llvm/llvm-project/commit/35e540d7801ac8e229fac8ef418ee81414f2f249.diff LOG: [Clang] Let isAnyArgInstantiationDependent handle Null template arguments (#174698) Unused template parameters, though never referenced during substitution, must remain in the MLTAL to preserve consistent template parameter indices. The null type placeholder plays this role, while isAnyArgInstantiationDependent() doesn't properly handle this case when checking nested constraints. There is no release note because this is a regression from concept parameter mapping. Fixes https://github.com/llvm/llvm-project/issues/174667 Added: Modified: clang/include/clang/Sema/Template.h clang/test/SemaTemplate/concepts.cpp Removed: ################################################################################ diff --git a/clang/include/clang/Sema/Template.h b/clang/include/clang/Sema/Template.h index e963439b05c98..b0170c21feb1a 100644 --- a/clang/include/clang/Sema/Template.h +++ b/clang/include/clang/Sema/Template.h @@ -188,7 +188,9 @@ enum class TemplateSubstitutionKind : char { bool isAnyArgInstantiationDependent() const { for (ArgumentListLevel ListLevel : TemplateArgumentLists) for (const TemplateArgument &TA : ListLevel.Args) - if (TA.isInstantiationDependent()) + // There might be null template arguments representing unused template + // parameter mappings in an MLTAL during concept checking. + if (!TA.isNull() && TA.isInstantiationDependent()) return true; return false; } diff --git a/clang/test/SemaTemplate/concepts.cpp b/clang/test/SemaTemplate/concepts.cpp index eed8b786f9954..d93391baf9926 100644 --- a/clang/test/SemaTemplate/concepts.cpp +++ b/clang/test/SemaTemplate/concepts.cpp @@ -1703,3 +1703,13 @@ struct : named_unit<"", thermodynamic_temperature, zeroth_kelvin> { struct ice_point : relative_point_origin<point<kelvin>> {}; } + +namespace GH174667 { + +template<class T, class, class U> +concept C = requires{ requires U(T(1)); }; + +template<C<void, bool> T> int f(); +void main() { f<int>(); } + +} _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
