Re: [PATCH v3 08/16] wchar: Avoid PLT entries with _FORTIFY_SOURCE

[Siddhesh Poyarekar <siddhesh@gotplt.org>]

On 2023-06-28 04:42, Frédéric Bérat wrote:
> The change is meant to avoid unwanted PLT entries for the wmemset and
> wcrtomb routines when _FORTIFY_SOURCE is set.
> 
> On top of that, ensure that *_chk routines have their hidden builtin
> definitions available.
> ---

Looks mostly OK except for a question below.

>   debug/wcrtomb_chk.c                               |  1 +
>   debug/wmemset_chk.c                               |  1 +
>   include/wchar.h                                   | 15 +++++++++++++++
>   .../ldbl-128ibm-compat/ieee128-fwprintf_chk.c     |  1 +
>   sysdeps/x86_64/multiarch/wmemset_chk.c            |  4 ++++
>   wcsmbs/bits/wchar2-decl.h                         |  4 ++--
>   6 files changed, 24 insertions(+), 2 deletions(-)
> 
> diff --git a/debug/wcrtomb_chk.c b/debug/wcrtomb_chk.c
> index 657be7471d..c156fe09c1 100644
> --- a/debug/wcrtomb_chk.c
> +++ b/debug/wcrtomb_chk.c
> @@ -28,3 +28,4 @@ __wcrtomb_chk (char *s, wchar_t wchar, mbstate_t *ps, size_t buflen)
>   {
>     return __wcrtomb_internal (s, wchar, ps, buflen);
>   }
> +libc_hidden_def (__wcrtomb_chk)
> diff --git a/debug/wmemset_chk.c b/debug/wmemset_chk.c
> index e11a92815e..1e7fc4fdea 100644
> --- a/debug/wmemset_chk.c
> +++ b/debug/wmemset_chk.c
> @@ -26,3 +26,4 @@ __wmemset_chk (wchar_t *s, wchar_t c, size_t n, size_t dstlen)
>   
>     return wmemset (s, c, n);
>   }
> +libc_hidden_builtin_def (__wmemset_chk)
> diff --git a/include/wchar.h b/include/wchar.h
> index 7b763bc24f..484e6b3fef 100644
> --- a/include/wchar.h
> +++ b/include/wchar.h
> @@ -166,6 +166,8 @@ libc_hidden_proto (putwc)
>   
>   libc_hidden_proto (mbrtowc)
>   libc_hidden_proto (wcrtomb)
> +libc_hidden_proto (__wcrtomb_chk)
> +
>   extern int __wcscmp (const wchar_t *__s1, const wchar_t *__s2)
>        __THROW __attribute_pure__;
>   libc_hidden_proto (__wcscmp)
> @@ -260,16 +262,25 @@ extern wchar_t *__wcschrnul (const wchar_t *__s, wchar_t __wc)
>   
>   extern wchar_t *__wmemset_chk (wchar_t *__s, wchar_t __c, size_t __n,
>   			       size_t __ns) __THROW;
> +libc_hidden_builtin_proto (__wmemset_chk)
>   
>   extern int __vfwscanf (__FILE *__restrict __s,
>   		       const wchar_t *__restrict __format,
>   		       __gnuc_va_list __arg)
>        attribute_hidden
>        /* __attribute__ ((__format__ (__wscanf__, 2, 0)) */;
> +
> +extern int __swprintf_chk (wchar_t *__restrict __s, size_t __n,
> +			   int __flag, size_t __s_len,
> +			   const wchar_t *__restrict __format, ...)
> +     __THROW /* __attribute__ ((__format__ (__wprintf__, 5, 6))) */;
> +
>   extern int __fwprintf (__FILE *__restrict __s,
>   		       const wchar_t *__restrict __format, ...)
>        attribute_hidden
>        /* __attribute__ ((__format__ (__wprintf__, 2, 3))) */;
> +extern int __wprintf_chk (int __flag, const wchar_t *__restrict __format,
> +			  ...);
>   extern int __vfwprintf_chk (FILE *__restrict __s, int __flag,
>   			    const wchar_t *__restrict __format,
>   			    __gnuc_va_list __arg)
> @@ -279,6 +290,10 @@ extern int __vswprintf_chk (wchar_t *__restrict __s, size_t __n,
>   			    const wchar_t *__restrict __format,
>   			    __gnuc_va_list __arg)
>        /* __attribute__ ((__format__ (__wprintf__, 5, 0))) */;
> +extern int __fwprintf_chk (__FILE *__restrict __stream, int __flag,
> +			   const wchar_t *__restrict __format, ...);
> +extern int __vwprintf_chk (int __flag, const wchar_t *__restrict __format,
> +			   __gnuc_va_list __ap);
>   
>   extern int __isoc99_fwscanf (__FILE *__restrict __stream,
>   			     const wchar_t *__restrict __format, ...);
> diff --git a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-fwprintf_chk.c b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-fwprintf_chk.c
> index 5b6cc3e768..10658ab125 100644
> --- a/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-fwprintf_chk.c
> +++ b/sysdeps/ieee754/ldbl-128ibm-compat/ieee128-fwprintf_chk.c
> @@ -17,6 +17,7 @@
>      <https://www.gnu.org/licenses/>.  */
>   
>   #include <stdarg.h>
> +#include <wchar.h>
>   #include <libio/libioP.h>

Why do you need this?

>   
>   extern int
> diff --git a/sysdeps/x86_64/multiarch/wmemset_chk.c b/sysdeps/x86_64/multiarch/wmemset_chk.c
> index ac93a1f376..00edf44918 100644
> --- a/sysdeps/x86_64/multiarch/wmemset_chk.c
> +++ b/sysdeps/x86_64/multiarch/wmemset_chk.c
> @@ -28,4 +28,8 @@
>   
>   libc_ifunc_redirected (__redirect_wmemset_chk, __wmemset_chk,
>   		       IFUNC_SELECTOR ());
> +# ifdef SHARED
> +__hidden_ver1 (__wmemset_chk, __GI___wmemset_chk, __redirect_wmemset_chk)
> +  __attribute__ ((visibility ("hidden"))) __attribute_copy__ (__wmemset_chk);
> +# endif
>   #endif
> diff --git a/wcsmbs/bits/wchar2-decl.h b/wcsmbs/bits/wchar2-decl.h
> index f3a2fd3c99..08c8ebd0e8 100644
> --- a/wcsmbs/bits/wchar2-decl.h
> +++ b/wcsmbs/bits/wchar2-decl.h
> @@ -71,7 +71,7 @@ extern wchar_t *__REDIRECT_NTH (__wmempcpy_chk_warn,
>   
>   extern wchar_t *__wmemset_chk (wchar_t *__s, wchar_t __c, size_t __n,
>   			       size_t __ns) __THROW;
> -extern wchar_t *__REDIRECT_NTH (__wmemset_alias, (wchar_t *__s, wchar_t __c,
> +extern wchar_t *__REDIRECT_FORTIFY_NTH (__wmemset_alias, (wchar_t *__s, wchar_t __c,
>   							  size_t __n), wmemset);
>   extern wchar_t *__REDIRECT_NTH (__wmemset_chk_warn,
>   				(wchar_t *__s, wchar_t __c, size_t __n,
> @@ -203,7 +203,7 @@ extern wchar_t *__REDIRECT (__fgetws_unlocked_chk_warn,
>   extern size_t __wcrtomb_chk (char *__restrict __s, wchar_t __wchar,
>   			     mbstate_t *__restrict __p,
>   			     size_t __buflen) __THROW __wur;
> -extern size_t __REDIRECT_NTH (__wcrtomb_alias,
> +extern size_t __REDIRECT_FORTIFY_NTH (__wcrtomb_alias,
>   				      (char *__restrict __s, wchar_t __wchar,
>   				      mbstate_t *__restrict __ps), wcrtomb) __wur;
>