Re: [PATCH 2/2] Include unistd.h.

From: Junio C Hamano <gitster@pobox.com>
Date: May 25, 2011, 18:30 UTC
Message-ID: <7vd3j64oq6.fsf@alter.siamese.dyndns.org>
In-Reply-To: <1306332924-28587-3-git-send-email-mduft@gentoo.org>

mduft@gentoo.org writes:

Show 20 quoted lines

> At least on Interix, NULL is defined in unistd.h, and not including it
> causes compilation failure.
>
> Signed-off-by: Markus Duft <mduft@gentoo.org>
> ---
>  compat/fnmatch/fnmatch.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/compat/fnmatch/fnmatch.c b/compat/fnmatch/fnmatch.c
> index 14feac7..0238cca 100644
> --- a/compat/fnmatch/fnmatch.c
> +++ b/compat/fnmatch/fnmatch.c
> @@ -25,6 +25,7 @@
>  # define _GNU_SOURCE	1
>  #endif
>  
> +#include <unistd.h>
>  #include <errno.h>
>  #include <fnmatch.h>
>  #include <ctype.h>

The header stddef.h is where NULL is supposed to be defined, and commonly used headers are supposed to define NULL the same way as stddef.h does. There is a conditional inclusion of stdlib.h in fnmatch.c and stdlib.h is one of those files; probably that is how the upstream pulls in NULL when compiling this.

But we don't define STDC_HEADERS nor _LIBC (and we shouldn't), so I don't know how the existing users of compat/fnmatch/ gets the defintion of NULL from. Output from "gcc -E -dD -DNO_FNMATCH compat/fnmatch/fnmatch.c" does not seem to show any NULL defined.

Other platforms (e.g. SunOS, IRIX, HPUX, Windows) use NO_FNMATCH_CASEFOLD and compile this file. How are they getting their NULLs?