https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123080
--- Comment #6 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:549bfeaa0bd2641ed99f1525caf3d54e2126396a commit r16-6432-g549bfeaa0bd2641ed99f1525caf3d54e2126396a Author: Egas Ribeiro <[email protected]> Date: Thu Dec 25 12:33:47 2025 +0000 c++: Fix ICE with requires-expression in lambda requires-clause [PR123080] When parsing a lambda with a trailing requires-clause, calling cp_parser_requires_clause_opt confused generic lambda parsing when implicit template parameters were involved. After failing to parse a type-requirement during tentative parsing and hitting error recovery code in cp_parser_skip_to_end_of_statement that aborted the current implicit template, attemping to finish the lambda declaration caused ICEs. Fix this by not aborting the current implicit template during tentative parsing and adding cleanup for fully_implicit_function_template_p. PR c++/123080 gcc/cp/ChangeLog: * parser.cc (cp_parser_skip_to_end_of_statement): Don't abort implicit templates during tentative parsing. (cp_parser_lambda_declarator_opt): Add cleanup for fully_implicit_function_template_p before parsing trailing_requires_clause. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/lambda-requires6.C: New test. * g++.dg/cpp2a/lambda-requires6a.C: New test. Signed-off-by: Egas Ribeiro <[email protected]> Reviewed-by: Jason Merrill <[email protected]>
