https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96229
--- Comment #2 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:6b1b5c255f859e75a2d74ae58a011e846d87a277 commit r11-3713-g6b1b5c255f859e75a2d74ae58a011e846d87a277 Author: Patrick Palka <ppa...@redhat.com> Date: Thu Oct 8 00:05:36 2020 -0400 c++: Set the constraints of a class type sooner [PR96229] In the testcase below, during processing (at parse time) of Y's base class X<Y>, convert_template_argument calls is_compatible_template_arg to check if the template argument Y is no more constrained than the parameter P. But at this point we haven't yet set Y's constraints, so get_normalized_constraints_from_decl yields NULL_TREE as the normal form and caches this result into the normalized_map. We set Y's constraints later in cp_parser_class_specifier_1 but the stale normal form in the normalized_map remains. This ultimately causes us to miss the constraint failure for Y<Z> because according to the cached normal form, Y is not constrained. This patch fixes this issue by moving up the call to associate_classtype_constraints so that we set constraints before we start processing a class's bases. gcc/cp/ChangeLog: PR c++/96229 * parser.c (cp_parser_class_specifier_1): Move call to associate_classtype_constraints from here to ... (cp_parser_class_head): ... here. * pt.c (is_compatible_template_arg): Correct documentation to say "argument is _no_ more constrained than the parameter". gcc/testsuite/ChangeLog: PR c++/96229 * g++.dg/cpp2a/concepts-class2.C: New test.
