[gfortran,patch] Fix spuriouis warnings about anonymous variables

[Paul Thomas]

François-Xavier,
> Hi all,
>
> I've been tracking the source of PR29459, which is a warning about a
> possibly used-uninitialized anonymous variable. The variable is not,
> in fact, used uninitialized, but the middle-end is not smart enough to
> see this, causing the warning.
>
> As I said in the PR, after finding the place where this temporary is
> generated, I could have set its TREE_NO_WARNING, but it seemed to me
> that there is little point to emit warnings about anonymous variables
> (front-end generated temporaries) in any case! They don't help the
> user, and the corresponding bug-reports tend to be not fixed quickly
> because a) it's only a diagnostic problem and b) they can be hard to
> track down.
>   
Agreed
> For this reasons, I suggest that we stop emitting warnings for
> anonymous variables generated by the front-end, in all cases.
> Regtested on x86_64-linux, OK to commit?
>   
OK for trunk

Thanks

Paul
> FX
>
>
>
> :ADDPATCH fortran:
>
> 2007-08-15  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
>
>         PR fortran/29459
>         * trans.c (gfc_create_var_np): Do not emit warnings for
>         anonymous variables.
>
>
>
> Index: trans.c
> ===================================================================
> --- trans.c     (revision 127490)
> +++ trans.c     (working copy)
> @@ -102,7 +102,15 @@ remove_suffix (char *name, int len)
>  tree
>  gfc_create_var_np (tree type, const char *prefix)
>  {
> -  return create_tmp_var_raw (type, prefix);
> +  tree t;
> +
> +  t = create_tmp_var_raw (type, prefix);
> +
> +  /* No warnings for anonymous variables.  */
> +  if (prefix == NULL)
> +    TREE_NO_WARNING (t) = 1;
> +
> +  return t;
>  }
>
>
>