[PATCH] meson.build: Remove the -Wvla-larger-then flag

[Daniel P. Berrangé]

On Thu, May 27, 2021 at 12:49:28PM +0200, Martin Kletzander wrote:
> On Thu, May 27, 2021 at 12:37:36PM +0200, Thomas Huth wrote:
> > The flag has a typo in it, it's "...-than=..." and not "...-then=...",
> > so this was in fact never used. Since we're also using -Wvla (without
> > size), we should already get warnings about any variable length arrays
> > anyway, so the additional "-Wvla-larger-than" does not make much sense
> > and thus we can simply drop this.
> > 
> > Signed-off-by: Thomas Huth <thuth at redhat.com>
> > ---
> > meson.build | 1 -
> > 1 file changed, 1 deletion(-)
> > 
> 
> This makes sense to me and I could not find any possible typo alias
> anywhere (like we have in virsh, for example).  The only thing I am
> unsure about is whether we want to actually use the proper naming.  The
> reason is that by default this is set to vla-larger-than=PTRDIFF_MAX
> which is pretty huge number.  On the other hand the man page for GCC
> says it is only effective with -ftree-vrp (-02 and above).

The -Wvla-larger-than=PTRDIFF_MAX default is irrelevant though,
because we've blocked all use of VLAs by using -Wvla.

IOW, AFAICT, -Wvla-larger-than and -Wvla are mutually exclusive
from a conceptual POV.

> 
> I do not see whether using the predefined alloc_max would make sense or
> not.  So I am not against just removing it, but feel free to overrule me
> as I did not look into this as much as others will be capable of.
> 
> Reviewed-by: Martin Kletzander <mkletzan at redhat.com>
> 
> > diff --git a/meson.build b/meson.build
> > index 4f23f9104e..40c841e777 100644
> > --- a/meson.build
> > +++ b/meson.build
> > @@ -390,7 +390,6 @@ cc_flags += [
> >   '-Wvariadic-macros',
> >   '-Wvector-operation-performance',
> >   '-Wvla',
> > -  '-Wvla-larger-then=4031',
> >   '-Wvolatile-register-var',
> >   '-Wwrite-strings',
> > ]
> > -- 
> > 2.27.0
> > 



Regards,
Daniel
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