[Bug c++/96437] [10/11/12 Regression] ICE in tree check: expected tree that contains ‘decl common’ structure, have ‘error_mark’ in synthesize_implicit_template_parm, at cp/parser.c:44246

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96437

--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Roger Sayle <sayle@gcc.gnu.org>:

https://gcc.gnu.org/g:3093f8a18e7a9c5a9bba976d58a2f91033e7f35a

commit r12-7550-g3093f8a18e7a9c5a9bba976d58a2f91033e7f35a
Author: Roger Sayle <roger@nextmovesoftware.com>
Date:   Tue Mar 8 23:23:19 2022 +0000

    PR c++/96437: ICE-on-invalid-code error recovery.

    This patch fixes PR c++/96437 which is an ICE-on-invalid-code regression
    affecting mainline.

    2022-03-08  Roger Sayle  <roger@nextmovesoftware.com>

    gcc/cp/ChangeLog
            PR c++/96437
            * parser.cc (synthesize_implicit_template_parm): Check that
            TREE_VALUE (new_parm) isn't error_mark_node before setting its
            DECL_VIRTUAL_P.

    gcc/testsuite/ChangeLog
            PR c++/96437
            * g++.dg/cpp2a/pr96437.C: New test case.