POSIX_C_SOURCE

[Erik Trulsson]

On Sat, Aug 30, 2003 at 10:30:01AM -0700, Matthew Dillon wrote:
>     This is precisely what I did a few days ago in DragonFly.  The warnings
>     were getting annoying.

Only a few days ago?  You must be harder to annoy than I am. :-)
I have been using that patch since January, which is when the warnings
got too annoying for me. 

(In case somebody wonders: No, I have not had any problems whatsoever
with that patch during the seven months I have used it, nor do I expect
any problems with it in the future.  The only effect the patch has is
to get rid of lots of annoying and (in this case) useless warnings.

Personally I can't think of any good reason to *not* apply that patch
to RELENG_4 as soon as possible, but since I don't have a commit bit
that decision is not mine to make.)

> 
> 					-Matt
> 					Matthew Dillon 
> 					<dillon at backplane.com>
> 
> :
> :On Sat, Aug 30, 2003 at 12:49:15PM -0400, Garrett Wollman wrote:
> :> In article <20030830161813.GA28890 at twisted.net> you write:
> :> 
> :> >Any chance that someone will finally commit the fixes to prevent the
> :> >POSIX_C_SOURCE warnings from showing up? I saw a number of posts on this
> :> >topic, but it still seems like it's not "officially committed"
> :> 
> :> >/usr/include/sys/cdefs.h:273: warning: `_POSIX_C_SOURCE' is not defined
> :> >/usr/include/sys/cdefs.h:279: warning: `_POSIX_C_SOURCE' is not defined
> :> 
> :> The warnings are wrong,[1] so you should probably ask the GCC people
> :> about that.
> :
> :The warnings are not wrong (see below), but anyway, since -stable uses
> :the "ancient" GCC 2.95.4, the GCC people are not likely to
> :give a damn in either case.  They usually don't care about the older
> :releases.
> :
> :> 
> :> -GAWollman
> :> 
> :> [1] That is to say, any identifier used in a preprocessor expression
> :> (after macro expansion) is defined to have a value of zero, and GCC
> :> should not be complaining about this.
> :
> :The code is correct, which is why GCC only gives a warning and not an
> :error.  Code looking like that are usually an indication of a
> :programmer error though, so GCC is perfectly right in warning about
> :it.  This is similar to the compiler warning about unused variables,
> :which isn't a bug either but often indicates a programmer mistake.
> :
> :To make gcc shut up, you can apply the following patch to cdefs.h
> :which makes the warnings go away, without changing the semantics of the
> :include file in any way.
> :
> :
> :Index: cdefs.h
> :===================================================================
> :RCS file: /ncvs/src/sys/sys/cdefs.h,v
> :retrieving revision 1.28.2.8
> :diff -u -r1.28.2.8 cdefs.h
> :--- cdefs.h	18 Sep 2002 04:05:13 -0000	1.28.2.8
> :+++ cdefs.h	29 Jan 2003 21:23:30 -0000
> :@@ -269,6 +269,8 @@
> :  * Our macros begin with two underscores to avoid namespace screwage.
> :  */
> : 
> :+#ifdef _POSIX_C_SOURCE
> :+
> : /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
> : #if _POSIX_C_SOURCE == 1
> : #undef _POSIX_C_SOURCE		/* Probably illegal, but beyond caring now. */
> :@@ -280,6 +282,8 @@
> : #undef _POSIX_C_SOURCE
> : #define	_POSIX_C_SOURCE		199209
> : #endif
> :+
> :+#endif /* _POSIX_C_SOURCE */
> : 
> : /* Deal with various X/Open Portability Guides and Single UNIX Spec. */
> : #ifdef _XOPEN_SOURCE
> :
> :

-- 
<Insert your favourite quote here.>
Erik Trulsson
ertr1013 at student.uu.se