https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99214
--- Comment #4 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-14 branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>: https://gcc.gnu.org/g:3dc43f7f4394f8705090232e3506e1e94f484877 commit r14-11616-g3dc43f7f4394f8705090232e3506e1e94f484877 Author: Patrick Palka <ppa...@redhat.com> Date: Mon Apr 14 11:20:13 2025 -0400 c++: wrong targs in satisfaction diagnostic context line [PR99214] In the three-parameter version of satisfy_declaration_constraints, when 't' isn't the most general template, then 't' won't correspond with 'args' after we augment the latter via add_outermost_template_args, and so the instantiation context that we push via push_tinst_level isn't quite correct: 'args' is a complete set of template arguments, but 't' is not necessarily the most general template. This manifests as misleading diagnostic context lines when issuing a satisfaction failure error, e.g. the below testcase without this patch we emit: In substitution of '... void A<int>::f<U>() ... [with U = int]' and with this patch we emit: In substitution of '... void A<int>::f<U>() ... [with U = char]'. This patch fixes this by passing the original 'args' to push_tinst_level, which ought to properly correspond to 't'. PR c++/99214 gcc/cp/ChangeLog: * constraint.cc (satisfy_declaration_constraints): Pass the original ARGS to push_tinst_level. gcc/testsuite/ChangeLog: * g++.dg/concepts/diagnostic20.C: New test. Reviewed-by: Jason Merrill <ja...@redhat.com> (cherry picked from commit 00966a7fdb1478b3af5254ff3a80a3ef336c5a94)
