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Re: [PATCH] #undef __GLIBC__


On Tue, Nov 15, 2005 at 06:17:04PM +0000, Maciej W. Rozycki wrote:
> On Tue, 15 Nov 2005, Robert Millan wrote:
> 
> > ITYM:
> > 
> >   #include <features.h>
> >   #ifdef __GLIBC__
> > 
> > The problem with this is, that you have no garantee <features.h> exists untill
> > you have identified the C library implementation somehow, so you can't include
> > it yet (chicken and egg).
> 
>  Then use <stdlib.h> -- it'd better exist everywhere.

There are a pair of corner cases:

  - Programs for which the maintainers insist in supporting very broken systems
    like, say, MS-DOG (portability for sane systems tends to suck a lot on such
    programs).

  - Programs that use cpp only for configuration of non-C stuff.  For example
    I've seen this before in X11 sources (both Xfree86 and X.org):

      http://cvsweb.xfree86.org/cvsweb/xc/config/cf/Imake.cf?rev=3.91
      http://necrotic.deadbeast.net/svn/xorg-x11/branches/6.9/xc/config/cf/Imake.cf

My conclussion is that trying to do system configuration using non-preprocessor
macros can be very awkward.  I would like very much to avoid it (and preferably
have Glibc's consentment for that).

-- 
Robert Millan


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