Re: [PATCH] S390: Fix building with --disable-mutli-arch [BZ #31196]

[Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>]

On 30/01/24 05:34, Stefan Liebler wrote:
> Starting with commits
> - 7ea510127e2067efa07865158ac92c330c379950
> string: Add libc_hidden_proto for strchrnul
> - 22999b2f0fb62eed1af4095d062bd1272d6afeb1
> string: Add libc_hidden_proto for memrchr
> 
> building glibc on s390x with --disable-multi-arch fails if only
> the C-variant of strchrnul / memrchr is used.  This is the case
> if gcc uses -march < z13.
> 
> The build fails with:
> ../sysdeps/s390/strchrnul-c.c:28:49: error: ‘__strchrnul_c’ undeclared here (not in a function); did you mean ‘__strchrnul’?
>    28 | __hidden_ver1 (__strchrnul_c, __GI___strchrnul, __strchrnul_c);
> 
> With --disable-multi-arch, __strchrnul_c is not available as string/strchrnul.c
> is just included without defining STRCHRNUL and thus we also don't have to create
> the internal hidden symbol.

LGTM, thanks.  In same topic, why s390 is not following the multiarch sysdep
folder organization followed by all others ports, where ifunc implementation
are put only in multiarch folder?

The multiarch mechanism was added to simplify this kind of code, the s390
seems gratuitous over complicated in this regard.

> ---
>  sysdeps/s390/memrchr-c.c   | 4 +++-
>  sysdeps/s390/strchrnul-c.c | 4 +++-
>  2 files changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/sysdeps/s390/memrchr-c.c b/sysdeps/s390/memrchr-c.c
> index b4b85725d3..f6ffe85572 100644
> --- a/sysdeps/s390/memrchr-c.c
> +++ b/sysdeps/s390/memrchr-c.c
> @@ -25,7 +25,9 @@
>  
>  # include <string/memrchr.c>
>  
> -# if defined SHARED && IS_IN (libc)
> +# if HAVE_MEMRCHR_IFUNC
> +#  if defined SHARED && IS_IN (libc)
>  __hidden_ver1 (__memrchr_c, __GI___memrchr, __memrchr_c);
> +#  endif
>  # endif
>  #endif
> diff --git a/sysdeps/s390/strchrnul-c.c b/sysdeps/s390/strchrnul-c.c
> index 7f2f1fd540..97fd9ffbf7 100644
> --- a/sysdeps/s390/strchrnul-c.c
> +++ b/sysdeps/s390/strchrnul-c.c
> @@ -24,7 +24,9 @@
>  # endif
>  
>  # include <string/strchrnul.c>
> -# if defined SHARED && IS_IN (libc)
> +# if HAVE_STRCHRNUL_IFUNC
> +#  if defined SHARED && IS_IN (libc)
>  __hidden_ver1 (__strchrnul_c, __GI___strchrnul, __strchrnul_c);
> +#  endif
>  # endif
>  #endif