Message-ID:	<39742B45.D30B4051@softhome.net>
Date:	Tue, 18 Jul 2000 12:02:45 +0200
From:	Laurynas Biveinis <lauras AT softhome DOT net>
X-Mailer:	Mozilla 4.73 [en] (Win98; U)
X-Accept-Language:	lt,en
MIME-Version:	1.0
To:	Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
CC:	djgpp-workers AT delorie DOT com
Subject:	Re: GCC headers and DJGPP port
References:	<Pine DOT SUN DOT 3 DOT 91 DOT 1000718121940 DOT 1391K-100000 AT is>
Reply-To:	djgpp-workers AT delorie DOT com

Eli Zaretskii wrote:
> > + #undef SIZE_TYPE
> > + #define SIZE_TYPE "long unsigned int"
> 
> I'm not sure I understand what exactly is this suggestion.  Where should
> this snippet go, and how would it solve the problem(s) at hand?

It would go to GCC source, target description header file. 
The explanation was earlier in this thread:

>   In message <200007172102 DOT XAA07817 AT loewis DOT home DOT cs DOT tu-berlin DOT de>you write:
>   > Now, the exact mechanism *how* it is achieved that the header file is
>   > an exact match of the target understanding of these types is a tricky
>   > question, however, there is no question *that* gcc must know about
>   > these types even without seeing a single target header file.
> The "how" of this question is the port maintainer figures out the right
> value and codes it into the target .h file.  For example:
>
> /* Make GCC agree with types.h.  */
> #undef SIZE_TYPE
> #undef PTRDIFF_TYPE
> 
> #define SIZE_TYPE "long unsigned int"
> #define PTRDIFF_TYPE "long int"

> Actually, I don't think I understand why stddef.h needs to be included
> instead of djtypes.h.  Could you please explain?

Let's say we've converted to GCC headers. Now some header wants to get 
size_t. Earlier he was including <sys/djtypes.h>. But now the only header
which knows about size_t is <stddef.h>, but including it is prohibited.
Thus there is a backdoor - you define __need_size_t, __need_null, etc.
and include <stddef.h>. Then it will silently give out only requested
definitions and nothing else.

Laurynas

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