From: Ramsay Jones <ramsay@ramsayjones.plus.com>
Date: Sun, 13 Aug 2017 19:45:04 GMT
Subject: Re: [PATCH 1/9] Convert pack-objects to size_t
Message-ID: <627042be-ab86-e9da-8c4e-5aac3278f5c6@ramsayjones.plus.com>
In-Reply-To: <20170813183026.GC31079@mail.zuhause>



On 13/08/17 19:30, Martin Koegler wrote:
> On Sat, Aug 12, 2017 at 02:47:25PM +0100, Ramsay Jones wrote:
>> On 32-bit Linux, off_t is 64-bit and size_t is 32-bit.
> 
> --- t.c ---
> #include <stddef.h>
> #include <stdio.h>
> 
> int main()
> {
> printf("%d %d\n", sizeof(size_t), sizeof(off_t));
> }
> ------------
> $ gcc -m32 -o t t.c
> $ ./t.c
> 4 4
> 
> So is that really true?

It should be, see commit b97e911643 ("Support for large files
on 32bit systems.", 17-02-2007), where you can see that the
_FILE_OFFSET_BITS macro is set to 64. This asks <stdio.h> et.al.,
to use the "Large File System" API and a 64-bit off_t.

I can't boot my 32-bit installation at the moment, and it seems
that my 64-bit multilib system is not playing ball:

  $ gcc -m32 -D_FILE_OFFSET_BITS=64 -o t t.c
  In file included from /usr/include/stdio.h:27:0,
                   from t.c:2:
  /usr/include/features.h:367:25: fatal error: sys/cdefs.h: No such file or directory
  compilation terminated.
  $ 

ATB,
Ramsay Jones