https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94255
--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Marek Polacek <mpola...@gcc.gnu.org>: https://gcc.gnu.org/g:21968d4ae067e3fa1c1728c8db26478e8ac8ad0b commit r11-175-g21968d4ae067e3fa1c1728c8db26478e8ac8ad0b Author: Marek Polacek <pola...@redhat.com> Date: Fri Apr 17 23:48:11 2020 -0400 c++: Fix crash with template spec in different namespace [PR94255] This is an ICE on invalid, because we're specializing S::foo in the wrong namespace. cp_parser_class_specifier_1 parses S::foo in M and then it tries to push the nested-name-specifier of foo, which is S. By that, we're breaking the assumption of push_inner_scope that the pushed scope must be a scope nested inside current scope: current scope is M, but the namespace context of S is N, and N is not nested in M, so we fell into an infinite loop in push_inner_scope_r. (cp_parser_class_head called check_specialization_namespace which already gave a permerror.) PR c++/94255 * parser.c (cp_parser_class_specifier_1): Check that the scope is nested inside current scope before pushing it. * g++.dg/template/spec41.C: New test.
