[Bug c++/66966] Missing diagnostic message for ill-formed program with anonymous enum

[manu at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66966

--- Comment #8 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
(In reply to Anders Granlund from comment #7)
> OK. Seems to work differently in Clang but I guess they don't have the same
> problem with legacy.

Changing defaults in GCC to match Clang is possible (we added caret, colors,
changed the behavior of https://gcc.gnu.org/wiki/FAQ#wnowarning), but someone
who thinks this is important enough needs to make the effort of implementing
the change, arguing convincingly for it and handling any issues that may arise.

The change is likely to be just splitting diagnostic_report_warnings_p so that
the check for inhibit_warnings in diagnostic.c:diagnostic_report_diagnostic()
can be moved after diagnostic->kind is reclassified while keeping the check for
system-headers as early as possible, so that warnings from system-headers
converted into errors are still suppressed.