GCC headers and DJGPP port

[Mike Stump]

> Date: Mon, 17 Jul 2000 14:34:27 -0400 (EDT)
> From: Eli Zaretskii <eliz@delorie.com>
> To: Mike Stump <mrs@windriver.com>

> > From: Mike Stump <mrs@windriver.com>
> > Date: Mon, 17 Jul 2000 10:36:53 -0700 (PDT)
> > 
> Sorry, I don't understand how can this ever work reliably.

Simple, gcc knows the target system, including details that affect
these things.  Does it mean that gcc has to know a bit about target
system, sure.  Welcome to gcc.

> I don't see how can GCC provide definitions that will never conflict
> with library internals.  Please tell what am I missing.

> How about a system with its own stddef.h?  Standard types such as
> the definition of NULL -- these are surely closely related to the
> internals of a library, right?

:-) Actually, this is the canonical example for of one that we prefer
our definition for.  Understand why we #define it to __null and you'll
gain a better understanding of the issues.

varargs.h, is another good example.  Ours works, it'll always work, we
prefer it, why not use it?  Is your version safe with
-fstrict-aliasing?  Are you sure?  By using ours, we know ours is.