[Bug fortran/52347] -Wno-tabs -Wall -Wno-tabs still warns about tabs

["manu at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52347

Manuel LÃpez-IbÃÃez <manu at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |manu at gcc dot gnu.org

--- Comment #1 from Manuel LÃpez-IbÃÃez <manu at gcc dot gnu.org> 2012-02-23 08:37:08 UTC ---
(In reply to comment #0)
> However, for tab warnings -Wno-tabs cannot be used to turn off the warning,
> enabled by -Wall.
> 
> I wouldn't be surprised if that also holds for other warnings, enabled by -Wall
> or -Wextra.
> 
> Found at
> http://groups.google.com/group/comp.lang.fortran/browse_thread/thread/9942915c9c41b151

Sure, it happens with many flags in fact, not only in Fortran, since -Wall
either does not check whether the flag was already initialized, or it sets the
value too early. Ideally, flags that enable other flags should be checked last,
and they should only touch flags that haven't been set already in the
command-line. But this is only done on a case-by-case basis by using -1 as
starting value (I did it mostly for -Wextra, -Wunused, and -Wimplicit). It
would be nice that the options handling code would take care of this, by
specifying the relations in *.opt files.