Re: [PATCH] RISC-V: fix linker message when relaxation deletes bytes

["Clément Chigot" <chigot@adacore.com>]

Hi Jeff,

On Sat, Oct 15, 2022 at 2:42 AM Jeff Law <jeffreyalaw@gmail.com> wrote:
>
>
> On 10/14/22 01:24, Clément Chigot via Binutils wrote:
> > On Fri, Oct 14, 2022 at 7:08 AM Nelson Chu <nelson@rivosinc.com> wrote:
> >> Hi,
> >>
> >> On Thu, Oct 13, 2022 at 8:06 PM Clément Chigot via Binutils
> >> <binutils@sourceware.org> wrote:
> >>> Gentle ping
> >>>
> >>> Thanks,
> >>> Clément
> >>>
> >>> On Thu, Oct 6, 2022 at 1:46 PM Clément Chigot <chigot@adacore.com> wrote:
> >>>> The section relaxation can delete some bytes resulting in the symbols'
> >>>> value being modified.
> >>>> As the linker messages retrieve a symbol information using the
> >>>> outsymbols field of abfd, it must be updated as well.
> >> Interesting, I never noticed this.  If this is necessary, then other
> >> targets should also update the output symbols when relaxing (nds32 and
> >> sh), but it seems like they don't do that as well.
> > Yeah, I agree there are probably other targets having a similar issue.
> > I don't know at what extend outsymbols is being used for. But the fact
> > that is being filled with "untouched" symbols in object files looks
> > weird to me. Maybe there is something to look into this direction.
> > For now, this patch aims just to fix ld-undefined on Risc-V targets.
> >
> >
>
> The target has to adjust the local and global symbols defined in the
> relaxed section.      I haven't done relaxing in a long time, but the
> one I'm most familiar with is the H8.  If you look at
> elf32_h8_relax_delete_bytes you'll see suitable code to update the local
> and global symbols.

Yeah, that's what was already done in the Risc-V function:
riscv_relax_delete_bytes.
However, local and global symbols aren't enough for linker warnings
and errors. These ones are using the "outsymbols" BFD field which IIUC
is reading the object files directly and thus cannot know about the
deleted bytes.
So I guess H8 might have the same kind of errors. Are ld-undefined
tests succeeding ?

Thanks,
Clémebt