Re: RFC: Changing AC_PROG_CC to AC_PROG_CC_C99 in top level configure

[Alan Modra <amodra@gmail.com>]

On Wed, May 05, 2021 at 08:05:29AM +0100, Iain Sandoe wrote:
> Alan Modra via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> 
> > On 2021-05-04 8:42 a.m., Nick Clifton wrote:
> > > Hi Guys,
> > > 
> > > On 4/30/21 7:36 PM, Simon Marchi wrote:
> > > > I think this fix is obvious enough, I encourage you to push it,
> > > 
> > > OK - I have pushed the patch to the mainline branches of both
> > > the gcc and binutils-gdb repositories.
> > 
> > Thanks Nick!  Incidentally, I checked the AC_PROG_CC_C99 change on
> > both binutils and gcc mainline using gcc-4.9.
> > 
> > To build gcc on x86_64 I found the following patch necessary to avoid
> > lots of
> > error: uninitialized const member ‘stringop_algs::stringop_strategy::max’
> > error: uninitialized const member ‘stringop_algs::stringop_strategy::alg’
> > when compiling config/i386/i386-options.c.  These can't be cured by
> > configuring with --disable-stage1-checking.
> > 
> > diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
> > index 97d6f3863cb..cc3b1b6d666 100644
> > --- a/gcc/config/i386/i386.h
> > +++ b/gcc/config/i386/i386.h
> > @@ -73,8 +73,8 @@ struct stringop_algs
> > {
> >   const enum stringop_alg unknown_size;
> >   const struct stringop_strategy {
> > -    const int max;
> > -    const enum stringop_alg alg;
> > +    int max;
> > +    enum stringop_alg alg;
> >     int noalign;
> >   } size [MAX_STRINGOP_ALGS];
> > };
> 
> does this relate to / fix PR 100246 (which seems to fire for some GCC
> versions as well
> as older clang)?

Yes, looks like the same issue.  I started making a similar fix to the
one you attached to the PR, then laziness kicked in after noticing the
errors were only given on the const elements.

-- 
Alan Modra
Australia Development Lab, IBM