Warnings on ignored returned values

[Octavian Voicu]

Hello,

I'm trying to compile wine with --enable-maintainer-mode and I get
lots of errors like `ignoring return value of ‘xxx’, declared with
attribute warn_unused_result'. I would like to submit a few patches to
fix them.

I noticed there's a page on the wiki for this:
http://wiki.winehq.org/IgnoredReturnValues

On the other hand, there are no indications on the policy of handling
them. Sometimes we just don't care about the return value, but I
haven't found a way to tell this to the compiler other than actually
using the return value. In other cases, errors might be relevant.

For example, for the code:

if (newdir) chdir(newdir);

would the following be an acceptable fix?

if (newdir) if (chdir(newdir) == -1) /* ignore error */ ;

Should I use WARNs to print the error, in cases where it might be relevant?

Thanks,
Octavian

[Alexandre Julliard]

Octavian Voicu  writes:
> Hello,
>
> I'm trying to compile wine with --enable-maintainer-mode and I get
> lots of errors like `ignoring return value of ‘xxx’, declared with
> attribute warn_unused_result'. I would like to submit a few patches to
> fix them.

Please don't. The warnings are spurious. Just disable fortify, or don't
use maintainer mode (you don't need it).

[Nate Gallaher]

Alexandre Julliard wrote:
> Octavian Voicu  writes:
> > Hello,
> >
> > I'm trying to compile wine with --enable-maintainer-mode and I get
> > lots of errors like `ignoring return value of ‘xxx’, declared with
> > attribute warn_unused_result'. I would like to submit a few patches to
> > fix them.
>
> Please don't. The warnings are spurious. Just disable fortify, or don't
> use maintainer mode (you don't need it).

Should --enable-maintainer-mode be purged then, or should some 
additional flag magic be added?  I ran into this a long time ago as well 
and made the assumption that it had bitrotted.

~Nate

[Octavian Voicu]

On Mon, Mar 22, 2010 at 3:21 PM, Nate Gallaher
 wrote:
> Should --enable-maintainer-mode be purged then, or should some additional
> flag magic be added?  I ran into this a long time ago as well and made the
> assumption that it had bitrotted.

Actually, in my case the problem is with Ubuntu -- the compiler is
configured to activate -D_FORTIFY_SOURCE=2 by default. I tried with:

CFLAGS="-D_FORTIFY_SOURCE=0" ../wine-git/configure --enable-maintainer-mode

and I don't get the spurious warnings any more.

The reason I want maintainer mode is that I want to work a bit on the
Wine64 issues. Most of them show up as warnings as I understand.

Octavian

[Marcus Meissner]

On Mon, Mar 22, 2010 at 03:28:17PM +0200, Octavian Voicu wrote:
> On Mon, Mar 22, 2010 at 3:21 PM, Nate Gallaher
>  wrote:
> > Should --enable-maintainer-mode be purged then, or should some additional
> > flag magic be added?  I ran into this a long time ago as well and made the
> > assumption that it had bitrotted.
>
> Actually, in my case the problem is with Ubuntu -- the compiler is
> configured to activate -D_FORTIFY_SOURCE=2 by default. I tried with:
>
> CFLAGS="-D_FORTIFY_SOURCE=0" ../wine-git/configure --enable-maintainer-mode
>
> and I don't get the spurious warnings any more.
>
> The reason I want maintainer mode is that I want to work a bit on the
> Wine64 issues. Most of them show up as warnings as I understand.

Well, you could also just ignore the warnings.

Ciao, Marcus

[Alexandre Julliard]

Nate Gallaher  writes:
> Should --enable-maintainer-mode be purged then, or should some
> additional flag magic be added?  I ran into this a long time ago as
> well and made the assumption that it had bitrotted.

Maintainer mode is meant to be used by the maintainer, i.e. by me. It
works just fine for what I need. There's no real reason for anybody else
to use it.