[PATCH 02/10] regex.h: Avoid #elif __STDC_VERSION__

[Sam James]

"H.J. Lu" <hjl.tools@gmail.com> writes:

> GCC 4.9 doesn't define __STDC_VERSION__ and issues an error:
>
> In file included from ../include/regex.h:2:0,
>                  from ../posix/re_comp.h:23,
>                  from ../include/re_comp.h:1,
>                  from /tmp/cih_test_7IKTRI.c:10:
> ../posix/regex.h:650:19: error: "__STDC_VERSION__" is not defined [-Werror=undef]
>  # elif 199901L <= __STDC_VERSION__ || defined restrict
>                    ^
>
> Use "#else" instead.
>
> Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
> ---
>  posix/regex.h | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/posix/regex.h b/posix/regex.h
> index ccf40cebc0..004dc62405 100644
> --- a/posix/regex.h
> +++ b/posix/regex.h
> @@ -647,10 +647,12 @@ extern int re_exec (const char *);
>       || 2 < __GNUC__ + (95 <= __GNUC_MINOR__) \
>       || __clang_major__ >= 3
>  #  define _Restrict_ __restrict
> -# elif 199901L <= __STDC_VERSION__ || defined restrict
> -#  define _Restrict_ restrict
>  # else
> -#  define _Restrict_
> +#  if 199901L <= __STDC_VERSION__ || defined restrict
> +#   define _Restrict_ restrict
> +#  else
> +#   define _Restrict_
> +#  endif
>  # endif
>  #endif
>  /* For the ISO C99 syntax
> @@ -661,13 +663,15 @@ extern int re_exec (const char *);
>  #ifndef _Restrict_arr_
>  # ifdef __restrict_arr
>  #  define _Restrict_arr_ __restrict_arr
> -# elif ((199901L <= __STDC_VERSION__ \
> +# else
> +#  if ((199901L <= __STDC_VERSION__ \
>           || 3 < __GNUC__ + (1 <= __GNUC_MINOR__) \
>           || __clang_major__ >= 3) \
>          && !defined __cplusplus)
> -#  define _Restrict_arr_ _Restrict_
> -# else
> -#  define _Restrict_arr_
> +#   define _Restrict_arr_ _Restrict_
> +#  else
> +#   define _Restrict_arr_
> +#  endif
>  # endif
>  #endif

I would mildly prefer 'if !defined ( ... )' but it would make the line
too long, so OK.

Reviewed-by: Sam James <sam@gentoo.org>