https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100362
--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Patrick Palka <ppa...@gcc.gnu.org>: https://gcc.gnu.org/g:2a6fc19e655e696bf0df9b7aaedf9848b23f07f3 commit r12-392-g2a6fc19e655e696bf0df9b7aaedf9848b23f07f3 Author: Patrick Palka <ppa...@redhat.com> Date: Mon May 3 13:35:37 2021 -0400 c++: base-clause parsing and implicit 'this' [PR100362] My r11-6815 change to defer access checking when processing a base-clause removed a pair of pushclass / popclass calls that seemed to be unnecessary now that we'd also defer access checking while parsing the base-clause. But it turns out these calls make a difference in the below testcase, where we have a local class whose base-clause implicitly uses the 'this' of the enclosing class. Before r11-6815, while parsing the base-clause of the local class, maybe_resolve_dummy would fail to resolve the dummy 'this' object because the current scope would be the local class. Now, since the current scope is the lambda, maybe_resolve_dummy succeeds and returns the 'this' for the enclosing class Qux. Later, during deferred instantiation of the local class, we get confused trying to resolve the access of 'a_' through this non-dummy 'this'. So this patch just reinstates the calls to pushclass / popclass that were removed in r11-6815. gcc/cp/ChangeLog: PR c++/100362 * parser.c (cp_parser_class_head): Reinstate calls to pushclass and popclass when parsing the base-clause that were removed in r11-6815. gcc/testsuite/ChangeLog: PR c++/100362 * g++.dg/cpp1y/lambda-generic-100362.C: New test.