Re: GCC arc port defaults to -fcommon

[Florian Weimer <fweimer@redhat.com>]

* Richard Biener:

> On Wed, Jul 7, 2021 at 11:56 AM Richard Biener
> <richard.guenther@gmail.com> wrote:
>>
>> On Wed, Jul 7, 2021 at 11:00 AM Florian Weimer via Gcc <gcc@gcc.gnu.org> wrote:
>> >
>> > It seems to me that the arc port still defaults to -fcommon, presumably
>> > due to this in gcc/common/config/arc/arc-common.c:
>> >
>> > static void
>> > arc_option_init_struct (struct gcc_options *opts)
>> > {
>> >   opts->x_flag_no_common = 255; /* Mark as not user-initialized.  */
>> >
>> >   /* Which cpu we're compiling for (ARC600, ARC601, ARC700, ARCv2).  */
>> >   arc_cpu = PROCESSOR_NONE;
>> > }
>> >
>> > Is that really necessary?  Is -fno-common broken on arc?
>>
>> It seems arc has -fcommon dependent on !TARGET_NO_SDATA_SET
>> but it should use global_options_set.x_flag_no_common instead of
>> such magic value.
>
> So sth like this (untested):
>
> diff --git a/gcc/common/config/arc/arc-common.c
> b/gcc/common/config/arc/arc-common.c
> index 6a119029616..c8ac7471744 100644
> --- a/gcc/common/config/arc/arc-common.c
> +++ b/gcc/common/config/arc/arc-common.c
> @@ -32,8 +32,6 @@ along with GCC; see the file COPYING3.  If not see
>  static void
>  arc_option_init_struct (struct gcc_options *opts)
>  {
> -  opts->x_flag_no_common = 255; /* Mark as not user-initialized.  */
> -
>    /* Which cpu we're compiling for (ARC600, ARC601, ARC700, ARCv2).  */
>    arc_cpu = PROCESSOR_NONE;
>  }
> diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c
> index 69f6ae464e1..b9097b11835 100644
> --- a/gcc/config/arc/arc.c
> +++ b/gcc/config/arc/arc.c
> @@ -1440,7 +1440,7 @@ arc_override_options (void)
>    if (flag_pic)
>      target_flags |= MASK_NO_SDATA_SET;
>
> -  if (flag_no_common == 255)
> +  if (!global_options_set.x_flag_no_common)
>      flag_no_common = !TARGET_NO_SDATA_SET;
>
>    /* Check for small data option */

But this means that arc still defaults to -fcommon with this change,
right?

Thanks,
Florian