Re: [PATCH 1/4] environ-selftests: Ignore -Wself-move warning

[Simon Marchi <simon dot marchi at polymtl dot ca>]

On 2017-06-21 22:29, Sergio Durigan Junior wrote:
> On Wednesday, June 21 2017, Simon Marchi wrote:
>
> > clang gives this warning:
> >
> > /home/emaisin/src/binutils-gdb/gdb/unittests/environ-selftests.c:139:7: 
> > error: explicitly moving variable of type 'gdb_environ' to itself 
> > [-Werror,-Wself-move]
> >   env = std::move (env);
> >   ~~~ ^            ~~~
> >
> > In this case, ignoring the warning locally is clearly the thing to do,
> > since it warns exactly about the behavior we want to test.  We also
> > don't want to disable this globally, because we would want the 
> > compiler
>
> "we would want the code compiler to warn"

Oops thanks.

> > if we wrote that in real code.
> >
> > I filed a bug in GCC's bugzilla to suggest to add this warning:
> >
> >   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81159
>
> Thanks!
>
> > gdb/ChangeLog:
> >
> > 	* unittests/environ-selftests.c (run_tests): Ignore -Wself-move
> > 	warning.
> > ---
> >  gdb/unittests/environ-selftests.c | 9 +++++++++
> >  1 file changed, 9 insertions(+)
> >
> > diff --git a/gdb/unittests/environ-selftests.c 
> > b/gdb/unittests/environ-selftests.c
> > index ecc3955..6989c5e 100644
> > --- a/gdb/unittests/environ-selftests.c
> > +++ b/gdb/unittests/environ-selftests.c
> > @@ -136,7 +136,16 @@ run_tests ()
> >    env.clear ();
> >    env.set ("A", "1");
> >    SELF_CHECK (strcmp (env.get ("A"), "1") == 0);
> > +
> > +#ifdef __clang__
> > +#pragma clang diagnostic push
> > +#pragma clang diagnostic ignored "-Wself-move"
> > +#endif /* __clang__ */
> >    env = std::move (env);
> > +#ifdef __clang__
> > +#pragma clang diagnostic pop
> > +#endif /* __clang__ */
>
> Wow.  I know we've discussed this before, but this is ugly :-/.  
> Anyway,
> this file is just a unittest, so I'm totally fine with this.

Yeah, I didn't expect to have to put the #ifdefs for __clang__ though.  
Without them, gcc emits a warning [-Wunknown-pragma].  We always have 
the option to turn -Wunknown-pragma off globally, what do you prefer?