https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113674
--- Comment #9 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-13 branch has been updated by Jakub Jelinek <ja...@gcc.gnu.org>: https://gcc.gnu.org/g:9de6ff5ec9a46951d2c71b5b32574a516a72b907 commit r13-8390-g9de6ff5ec9a46951d2c71b5b32574a516a72b907 Author: Jakub Jelinek <ja...@redhat.com> Date: Mon Feb 12 20:45:01 2024 +0100 attribs: Don't canonicalize lookup_scoped_attribute_spec argument [PR113674] The C and C++ FEs when parsing attributes already canonicalize them (i.e. if they start with __ and end with __ substrings, we remove those). lookup_attribute already verifies in gcc_assert that the first character of name is not an underscore, and even lookup_scoped_attribute_spec doesn't attempt to canonicalize the namespace it is passed. But for some historic reason it was canonicalizing the name argument, which misbehaves when an attribute starts with ____ and ends with ____. I believe it is just wrong to try to canonicalize lookup_scope_attribute_spec name attribute, it should have been canonicalized already, in other spots where it is called it is already canonicalized before. 2024-02-12 Jakub Jelinek <ja...@redhat.com> PR c++/113674 * attribs.cc (extract_attribute_substring): Remove. (lookup_scoped_attribute_spec): Don't call it. * c-c++-common/Wattributes-3.c: New test. (cherry picked from commit b42e978f29b33071addff6d7bb8bcdb11d176606)