Re: RFA: #define _GNU_SOURCE to get strsignal prototoype

[Kevin Buettner <kevinb@redhat.com>]

On 07 Oct 2004 11:08:01 -0500
Jim Blandy <jimb@redhat.com> wrote:

> This removes some compilation warnings on older Red Hat systems.
> #defining _GNU_SOURCE is the documented way to get these declarations
> from GNU C Library header files.  From "(libc) Feature Test Macros":
> 
>        You should define these macros by using `#define' preprocessor
>     directives at the top of your source code files.  These directives
>     _must_ come before any `#include' of a system header file.  It is best
>     to make them the very first thing in the file, preceded only by
>     comments.  You could also use the `-D' option to GCC, but it's better
>     if you make the source files indicate their own meaning in a
>     self-contained way.
> 
>     ...
> 
>      - Macro: _GNU_SOURCE
>          If you define this macro, everything is included: ISO C89,
>          ISO C99, POSIX.1, POSIX.2, BSD, SVID, X/Open, LFS, and GNU
>          extensions.  In the cases where POSIX.1 conflicts with BSD, the
>          POSIX definitions take precedence.
> 
> 2004-09-24  Jim Blandy  <jimb@redhat.com>
> 
> 	* samples/async.c: #define _GNU_SOURCE before #including any
> 	files, to get prototypes for GNU-specific functions like
> 	strsignal.

Okay.

Kevin