https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124794
--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The trunk branch has been updated by Jason Merrill <[email protected]>: https://gcc.gnu.org/g:719156070f5f5f9070a4d9b736c238b5d028f719 commit r17-1259-g719156070f5f5f9070a4d9b736c238b5d028f719 Author: feedable <[email protected]> Date: Wed Jun 3 08:40:53 2026 -0400 c++/reflection: member function template splicing [PR124794] cp_parser_splice_expression is stripping BASELINKs before resolving the expr; checks if the result is a BASELINK after that (by which point it never is). To fix it, stop stripping the BASELINK, add handling to check_splice_expr instead. In cp_parser_splice_specifier, the additional template param parsing fails to detect that the reflection is a template if it's wrapped in a BASELINKs, and decides not to parse the splice-specialization-specifier if the 'template' keyword is missing. Grab the data from the reflection instead. During template instantiation, we blindly substitute the template part of a TEMPLATE_ID_EXPR, even if it's a SPLICE_EXPR. This, in turn, substitutes the SPLICE_EXPR as-if it had no template arguments and finishes up the expression, which interferes with later processing by TEMPLATE_ID_EXPR. To fix, we defer such TEMPLATE_ID_EXPRs to tsubst_splice_expr, which itself performs the substitution of a TEMPLATE_ID_EXPR and finishes up the expression. check_splice_expr now also accepts TEMPLATE_ID_EXPRs in tsubst_splice_expr; this is uniform with cp_parser_splice_expression, and required in order to handle `template[:dep:]<>` where `dep` does not reflect a template. PR c++/124794 PR c++/125069 gcc/cp/ChangeLog: * parser.cc (cp_parser_splice_specifier): Do not strip BASELINKs. (cp_parser_splice_expression): Add parsing for member function template specializations without the "template" keyword. * pt.cc (tsubst_splice_expr): Handle TEMPLATE_ID_EXPR where the template part is a SPLICE_EXPR. (tsubst_expr): Defer to tsubst_splice_expr when the template part of TEMPLATE_ID_EXPR is a SPLICE_EXPR. * reflect.cc (check_splice_expr): Add handling for BASELINKs. gcc/testsuite/ChangeLog: * g++.dg/reflect/member19.C: Enable tests. * g++.dg/reflect/splice15.C: New test. * g++.dg/reflect/splice16.C: New test. Reviewed-by: Jason Merrill <[email protected]>
