Author: keinflue Date: 2025-08-09T20:03:02-03:00 New Revision: 4c0a7b72f7fe7786e12264aec2b990177222778c
URL: https://github.com/llvm/llvm-project/commit/4c0a7b72f7fe7786e12264aec2b990177222778c DIFF: https://github.com/llvm/llvm-project/commit/4c0a7b72f7fe7786e12264aec2b990177222778c.diff LOG: [clang] Distinguish NTTPs with deduced types in variable template partial specializations (#152864) If a template argument in a partial specialization of a variable template directly refers to a NTTP of the specialization without implicit type conversion it was assumed that the NTTP is identical to that of the primary template. This doesn't hold if the primary template's NTTP uses a deduced type, so instead compare the types explicitly as well. The affected function is used only to provide an improved early error if the partial specialization has identical template arguments to the primary template. The actual check that the partial specialization is more specialized happens later. Fixes #118190 Fixes #152750 Added: Modified: clang/docs/ReleaseNotes.rst clang/lib/Sema/SemaTemplate.cpp clang/test/SemaTemplate/temp_arg_nontype_cxx1z.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index c6b0d32853da8..a8b7a29933945 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -188,6 +188,7 @@ Bug Fixes to C++ Support (``[[assume(expr)]]``) creates temporary objects. - Fix the dynamic_cast to final class optimization to correctly handle casts that are guaranteed to fail (#GH137518). +- Fix bug rejecting partial specialization of variable templates with auto NTTPs (#GH118190). Bug Fixes to AST Handling ^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp index 3441613e1acc6..72d98ca391f4b 100644 --- a/clang/lib/Sema/SemaTemplate.cpp +++ b/clang/lib/Sema/SemaTemplate.cpp @@ -4083,7 +4083,6 @@ static bool CheckTemplateSpecializationScope(Sema &S, NamedDecl *Specialized, static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D); static bool isTemplateArgumentTemplateParameter(const TemplateArgument &Arg, - NamedDecl *Param, unsigned Depth, unsigned Index) { switch (Arg.getKind()) { @@ -4123,8 +4122,9 @@ static bool isTemplateArgumentTemplateParameter(const TemplateArgument &Arg, } static bool isSameAsPrimaryTemplate(TemplateParameterList *Params, + TemplateParameterList *SpecParams, ArrayRef<TemplateArgument> Args) { - if (Params->size() != Args.size()) + if (Params->size() != Args.size() || Params->size() != SpecParams->size()) return false; unsigned Depth = Params->getDepth(); @@ -4141,9 +4141,19 @@ static bool isSameAsPrimaryTemplate(TemplateParameterList *Params, Arg = Arg.pack_begin()->getPackExpansionPattern(); } - if (!isTemplateArgumentTemplateParameter(Arg, Params->getParam(I), Depth, - I)) + if (!isTemplateArgumentTemplateParameter(Arg, Depth, I)) return false; + + // For NTTPs further specialization is allowed via deduced types, so + // we need to make sure to only reject here if primary template and + // specialization use the same type for the NTTP. + if (auto *SpecNTTP = + dyn_cast<NonTypeTemplateParmDecl>(SpecParams->getParam(I))) { + auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Params->getParam(I)); + if (!NTTP || NTTP->getType().getCanonicalType() != + SpecNTTP->getType().getCanonicalType()) + return false; + } } return true; @@ -4341,7 +4351,7 @@ DeclResult Sema::ActOnVarTemplateSpecialization( } if (isSameAsPrimaryTemplate(VarTemplate->getTemplateParameters(), - CTAI.CanonicalConverted) && + TemplateParams, CTAI.CanonicalConverted) && (!Context.getLangOpts().CPlusPlus20 || !TemplateParams->hasAssociatedConstraints())) { // C++ [temp.class.spec]p9b3: diff --git a/clang/test/SemaTemplate/temp_arg_nontype_cxx1z.cpp b/clang/test/SemaTemplate/temp_arg_nontype_cxx1z.cpp index c35743b87adbc..9c25e26f43c36 100644 --- a/clang/test/SemaTemplate/temp_arg_nontype_cxx1z.cpp +++ b/clang/test/SemaTemplate/temp_arg_nontype_cxx1z.cpp @@ -621,3 +621,8 @@ namespace GH73460 { int j; template struct A<int&, j, j>; } // namespace GH73460 + +namespace GH118190 { + template <auto> int x; + template <int i> int x<i>; +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
