Re: warning flags in 2.4.1

[George Neuner]

At 08:50 PM 8/4/2010, Joel E. Denny wrote:

> George wrote:
> > > Also on page 114, the manual says "--warnings=none" or "-Wnone" should
> > > suppress all warnings.  This does not work.  Grammar warnings, 
> if any, are
> > > generated regardless of this setting.
> >
> > Thanks for mentioning that.  I hadn't noticed it before, and I agree it is
> > confusing.  I think the idea was that -Wnone (or --warnings=none) simply
> > disables all warnings that can be enabled by the other -W options.  It's
> > not clear to me if the documentation or the behavior needs to be fixed
> > here.
>
> Any opinions on this from anyone?
>
> If we decide that -Wnone should affect all warnings, then we probably need
> to add some kind of -Wother option for all warnings that do not have their
> own -W option.  The documentation should make it clear that we might later
> move warnings from -Wother to new, more specific -W options.
>
> Regardless of which functionality we pick for -Wnone, it probably should
> not affect -Werror.  Currently, it disables it.  Even if we decide that
> -Wnone should disable all warnings, it still should not affect -Werror in
> the following case:
>
>   bison -Werror -Wnone -Wyacc parser.y
>
> That is, POSIX Yacc warnings would be the only warnings and would be
> treated as errors.

I think the real issue is the interpretation of the -W flags and the 
documentation.

Generally when I see something that says "-Wblah warns of blah blah 
...", I assume that I will not get those warnings unless I specify 
that flag.  By that interpretation only one of -Wblah or -Wno-blah 
should be necessary and -Wnone is superfluous if all it does it 
suppress other named -W warnings.

The only real use case I see for -Wnone is to force a clean build 
from a grammar that has known warnings ... some companies have a 
policy about clean test/release builds and the person doing the build 
isn't always the developer.  But it is normal to have different flags 
for different types of builds so I don't see a problem with making 
-Wnone incompatible with other -W flags.

George