[alsa-devel] snd_ctl compiler warnings

[Alan Horstmann]

On Friday 07 November 2008 11:19, you wrote:
> At Fri, 7 Nov 2008 10:32:22 +0000,
>
> Alan Horstmann wrote:
> > On Friday 07 November 2008 09:58, you wrote:
> > > At Fri, 7 Nov 2008 08:52:43 +0000,
> > >
> > > Alan Horstmann wrote:
> > > > The code I am working with at present includes unremarkable lines
> > > > such as:
> > > >
> > > > 		snd_ctl_elem_value_t *line_in_vol;
> > > > 		snd_ctl_elem_value_alloca(&line_in_vol);
> > > >
> > > > Building this with a cross compiler for arm based on gcc 4.2.1 gives
> > > > this
> > > >
> > > > warning for the 2nd line:
> > > > : warning: the address of 'line_in_vol' will always evaluate as
> > > > : 'true'
> > > >
> > > > but an older compiler on the desktop does not show this.  Would this
> > > > warning be expected in these circumstances, or is the compiler being
> > > > over zealous? Am I missing something or is there a straightforward
> > > > way to avoid such warnings?  (Code runs OK).
> > >
> > > Try the later version of alsa-lib.
> > > This should have been already fixed.
> >
> > Thanks very much.  You presumably refer to:
> >
> > http://
> > git.alsa-project.org/?p=alsa-lib.git;a=commit;h=68e5771a6f7a2aae2dbd02a09
> >7719bcd25c6f307
> >
> > Right now a rebuild of the working environment would be a bit tricky.  At
> > the next opportunity I'll see if we can apply that patch to alsa-lib (I
> > think it is 1.0.15 -based) and rebuild.  In the meantime the warnings are
> > presumably fairly harmless?
>
> Yes.  It's just a noise and can be safely ignored.

Sorry if I'm making unnecesssary noise also!

Actually, on reflection I realised that as they are just macros in the header 
files, and are therefore not part of the embedded alsa-lib (which I cannot 
change straight away) I hand edited the include/alsa/control.h, adding the 
helper function locally & substituting the _alloca(..) macros...

...compiler now silent.  Much thanks for your assistance.

Alan