Re: string handling backport from CVS

[GOTO Masanori <gotom@debian.or.jp>]

At Mon, 19 Jul 2004 23:10:57 -0400,
Jeff Bailey wrote:
> Anyone object if I add:
> 
> 2004-05-26  Jakub Jelinek  <jakub@redhat.com>
> 
>         * include/string.h (mempcpy, stpcpy): Add
> libc_hidden_builtin_proto.
>         * string/bits/string2.h (memset): Disable macro for GCC 3.0+.
>         (__mempcpy): Use __builtin_mempcpy for GCC 3.4+.
>         (strchr): For GCC 3.2+, only use __rawmemchr if second argument
> is
>         constant '\0' and first argument is not constant.
>         (__stpcpy): Use __builtin_stpcpy for GCC 3.4+.
>         (strncpy): Remove #ifdef _USE_STRING_ARCH_mempcpy variant.
>         For GCC 3.2+ use __builtin_strncpy.
>         (strncat): For GCC 3.2+ use __builtin_strncat.
>         (strcmp): For GCC 3.2+ use __builtin_strcmp if both arguments
> are
>         constant.
>         (strcspn, strspn, strpbrk): For GCC 3.2+, use builtin function
>         if both arguments are constant.
> 
> (There's a follow up patch to this that should also be included for
> completeness)
> 
> To glibc?  Using the gcc builtins fixes a segfault on the Hurd where
> threads are used in a statically linked executable.  Like the root
> filesystem. =)
> 
> I don't know enough about string handling in gcc to know for certain how
> safe this is.  I will cheerfully test on i386, sparc, ia64 and hppa to
> make sure though.
> 
> (I'll do this if no objections by the end of OLS)

I have no objection because you tested it, but I think it's good idea
that you provide the patch.

Regards,
-- gotom