https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96137
--- Comment #6 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:f8f5388c9e94d4324c31d82b335fa138518e3171 commit r11-6967-gf8f5388c9e94d4324c31d82b335fa138518e3171 Author: Marek Polacek <pola...@redhat.com> Date: Thu Jan 28 22:18:32 2021 -0500 c++: Fix infinite looping with invalid operator [PR96137] My r11-86 adjusted cp_parser_class_name to do - scope = parser->scope; + scope = parser->scope ? parser->scope : parser->context->object_type; if (scope == error_mark_node) return error_mark_node; but that caused endless looping in cp_parser_type_specifier_seq (the while (true) loop) in this invalid test, because we never set a parser error, therefore cp_parser_type_specifier returned error_mark_node instead of NULL_TREE, and we never issued the "expected type-specifier" error. At first I thought I'd just add cp_parser_simulate_error right before the return, but that regresses crash81.C -- we'd emit multiple errors for "T::X". So the next best thing seemed to revert to pre-r11-86 behavior: return early when parser->scope is bad, otherwise proceed to get the parser error. gcc/cp/ChangeLog: PR c++/96137 * parser.c (cp_parser_class_name): If parser->scope is error_mark_node, return it, otherwise continue. gcc/testsuite/ChangeLog: PR c++/96137 * g++.dg/parse/error63.C: New test.
