[Bug preprocessor/71851] Get more time granularity at preprocessing

["daniel.gutson at intel dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71851

--- Comment #8 from Daniel Gutson <daniel.gutson at intel dot com> ---
(In reply to Jakub Jelinek from comment #7)
> (In reply to Daniel Gutson from comment #5)
> > This macro would change break reproduceability as much as __TIME__ does.
> 
> __TIME__ is now being warned on if requested (-Wdate-time), and can be
> changed
> through environment variables - SOURCE_DATE_EPOCH env var - and for
> -fcompare-debug SOURCE_DATE_EPOCH is set by the driver for both invocations
> the same.
> So, as you can see, there is a strong shift away from __DATE__/__TIME__.

OK, granted. I complain that build reproduceability is a specific requirement
for a particular audience of users; other users may need just the opposite and
IMVHO I think have the same right to claim it. This is of course a dead end
discussion we won't have here. We will implement this as a cpp plugin, so feel
free to close the issue.