Re: PING: V4 [PATCH] gas: Extend .symver directive

["H.J. Lu" <hjl.tools@gmail.com>]

On Wed, Apr 22, 2020 at 1:52 AM Alan Modra <amodra@gmail.com> wrote:
>
> On Wed, Apr 22, 2020 at 11:51:10AM +0930, Alan Modra wrote:
> > On Tue, Apr 21, 2020 at 06:19:45PM -0700, H.J. Lu wrote:
> > > On Tue, Apr 21, 2020 at 4:52 PM Alan Modra <amodra@gmail.com> wrote:
> > > > I wonder if ".symver intsym, extsym@@nodename, remove" ought to really
> > > > remove the symbol resulting in an assembly error if referenced?
>
> Turning this proposal into a proper patch.  What do you think?
>
>         * config/obj-elf.c (elf_frob_symbol): Unconditionally remove
>         symbol for ".symver .. remove".
>         * doc/as.texi (.symver): Update.
>         * testsuite/gas/symver/symver11.s: Make foo weak.
>         * testsuite/gas/symver/symver11.d: Expect an error.
>         * testsuite/gas/symver/symver7.d: Allow other random symbols.
>
> diff --git a/gas/config/obj-elf.c b/gas/config/obj-elf.c
> index 409ea4d6be..4bdddc9056 100644
> --- a/gas/config/obj-elf.c
> +++ b/gas/config/obj-elf.c
> @@ -2569,9 +2569,7 @@ elf_frob_symbol (symbolS *symp, int *puntp)
>               elfsym->internal_elf_sym.st_other |= STV_HIDDEN;
>               break;
>             case visibility_remove:
> -             /* Remove the symbol if it isn't used in relocation.  */
> -             if (!symbol_used_in_reloc_p (symp))
> -               symbol_remove (symp, &symbol_rootP, &symbol_lastP);
> +             symbol_remove (symp, &symbol_rootP, &symbol_lastP);
>               break;
>             case visibility_local:
>               S_CLEAR_EXTERNAL (symp);
> diff --git a/gas/doc/as.texi b/gas/doc/as.texi
> index 8669879c87..a65ddad5f5 100644
> --- a/gas/doc/as.texi
> +++ b/gas/doc/as.texi
> @@ -7129,13 +7129,12 @@ building a shared library.  If you are attempting to override a versioned
>  symbol from a shared library, then @var{nodename} should correspond to the
>  nodename of the symbol you are trying to override.  The optional argument
>  @var{visibility} updates the visibility of the original symbol.  The valid
> -visibilities are @code{local}, @code {hidden}, and @code {remove}.  The
> +visibilities are @code{local}, @code{hidden}, and @code{remove}.  The
>  @code{local} visibility makes the original symbol a local symbol
>  (@pxref{Local}).  The @code{hidden} visibility sets the visibility of the
>  original symbol to @code{hidden} (@pxref{Hidden}).  The @code{remove}
> -visibility removes the original symbol from the symbol table if it isn't
> -used in relocation.  If visibility isn't specified, the original symbol
> -is unchanged.
> +visibility removes the original symbol from the symbol table.  If visibility
> +isn't specified, the original symbol is unchanged.
>
>  If the symbol @var{name} is not defined within the file being assembled, all
>  references to @var{name} will be changed to @var{name2@@nodename}.  If no
> diff --git a/gas/testsuite/gas/symver/symver11.d b/gas/testsuite/gas/symver/symver11.d
> index 0e3e7f14b7..caa76e167d 100644
> --- a/gas/testsuite/gas/symver/symver11.d
> +++ b/gas/testsuite/gas/symver/symver11.d
> @@ -1,8 +1,2 @@
> -#readelf: -rsW
>  #name: symver symver11
> -
> -#...
> -[0-9a-f]+ +[0-9a-f]+ +R_.* +[0-9a-f]+ +foo *.*
> -#...
> - +[0-9]+: +0+ +1 +OBJECT +GLOBAL +DEFAULT +[0-9]+ +foo
> -#pass
> +#error: .*symbol cannot be used on reloc
> diff --git a/gas/testsuite/gas/symver/symver11.s b/gas/testsuite/gas/symver/symver11.s
> index 08416be0f0..2c7c6e7f6b 100644
> --- a/gas/testsuite/gas/symver/symver11.s
> +++ b/gas/testsuite/gas/symver/symver11.s
> @@ -1,5 +1,5 @@
>         .data
> -       .globl foo
> +       .weak foo
>         .type foo,%object
>  foo:
>         .byte 0
> diff --git a/gas/testsuite/gas/symver/symver7.d b/gas/testsuite/gas/symver/symver7.d
> index 5152678a48..2e956a6a1b 100644
> --- a/gas/testsuite/gas/symver/symver7.d
> +++ b/gas/testsuite/gas/symver/symver7.d
> @@ -3,6 +3,7 @@
>
>  #...
>   +[0-9]+: +0+ +1 +OBJECT +GLOBAL +HIDDEN +[0-9]+ +foo
> +#...
>   +[0-9]+: +0+ +1 +OBJECT +GLOBAL +DEFAULT +[0-9]+ +foo@version1
>   +[0-9]+: +0+ +1 +OBJECT +GLOBAL +DEFAULT +[0-9]+ +foo@@version2
>  #pass
>
> --
> Alan Modra
> Australia Development Lab, IBM

Works for me.

Thanks.

-- 
H.J.