On Mon, Apr 12, 2021 at 03:24:00PM +0200, Martin Liška wrote:
> On 4/12/21 2:45 PM, Jakub Jelinek wrote:
> > On Mon, Apr 12, 2021 at 02:32:35PM +0200, Martin Liška wrote:
> >> +If you have an older release of binutils release, then symbol alias needs
> >> to
> >
> > s/binutils release/binutils/
>
> Fixed.
>
> >
> >> +be used:
> >> +
> >> +@smallexample
> >> +__attribute__ ((__symver__ ("foo@@VERS_2")))
> >> +__attribute__ ((alias ("foo_v1")))
> >> +int symver_foo_v1 (void);
> >> +@end smallexample
> >
> > The example should show two versions of foo rather than just one, otherwise
> > it will confuse users. For symbol versions which just a single symbol they
> > don't need any aliases...
>
> Very good point! Is it fine now?
Ok, thanks.
> >From 6dda0ec10a1b0c60e6e9afe7fc45370d0132b5e3 Mon Sep 17 00:00:00 2001
> From: Martin Liska <mli...@suse.cz>
> Date: Mon, 12 Apr 2021 13:42:33 +0200
> Subject: [PATCH] docs: update symver attribute description
>
> gcc/ChangeLog:
>
> * doc/extend.texi: Be more precise in documentation
> of symver attribute.
> ---
> gcc/doc/extend.texi | 28 +++++++++++++++++++---------
> 1 file changed, 19 insertions(+), 9 deletions(-)
>
> diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
> index e28e1860990..6542ada6583 100644
> --- a/gcc/doc/extend.texi
> +++ b/gcc/doc/extend.texi
> @@ -3848,23 +3848,33 @@ foo_v1 (void)
> Will produce a @code{.symver foo_v1, foo@@VERS_1} directive in the assembler
> output.
>
> -One can also define multiple version for a given symbol.
> +One can also define multiple version for a given symbol
> +(starting from binutils 2.35).
>
> @smallexample
> __attribute__ ((__symver__ ("foo@@VERS_2"), __symver__ ("foo@@VERS_3")))
> int symver_foo_v1 (void)
> @{
> @}
> -
> -__attribute__ ((__symver__ ("bar@@VERS_2")))
> -__attribute__ ((__symver__ ("bar@@VERS_3")))
> -int symver_bar_v1 (void)
> -@{
> -@}
> @end smallexample
>
> -This example creates an alias of @code{foo_v1} with symbol name
> -@code{symver_foo_v1} which will be version @code{VERS_2} of @code{foo}.
> +This example creates a symbol name @code{symver_foo_v1}
> +which will be version @code{VERS_2} and @code{VERS_3} of @code{foo}.
> +
> +If you have an older release of binutils, then symbol alias needs to
> +be used:
> +
> +@smallexample
> +__attribute__ ((__symver__ ("foo@@VERS_2")))
> +int foo_v1 (void)
> +{
> + return 0;
> +}
> +
> +__attribute__ ((__symver__ ("foo@VERS_3")))
> +__attribute__ ((alias ("foo_v1")))
> +int symver_foo_v1 (void);
> +@end smallexample
>
> Finally if the parameter is @code{"@var{name2}@@@@@var{nodename}"} then in
> addition to creating a symbol version (as if
> --
> 2.31.1
>
Jakub
