Re: [ttyrpld-user] [YBA] Bug: sizeof struct rpldsk_packet is compiler dependent

[Jonathan B. A. <yb...@tk...>]

Hi Jan,
Thanks. I verified that your explanation is correct - it's word-size 
dependant, not a GCC bug.

  - yba


On Wed, 1 May 2013, Jan Engelhardt wrote:

> Date: Wed, 1 May 2013 17:51:33 +0200 (CEST)
> From: Jan Engelhardt <je...@in...>
> To: Jonathan Ben Avraham <yb...@tk...>
> Cc: tty...@li...
> Subject: Re: [ttyrpld-user] [YBA] Bug: sizeof struct rpldsk_packet is compiler
>      dependent
> 
>
> On Wednesday 2013-05-01 17:34, Jonathan Ben Avraham wrote:
>
>> If you put attribute "packed" on rpltme then the struct rpldsk_packet will be
>> only 20 bytes long in all GCC versions.
>
> That is the point. The spec says that it should be totally packed,
> IOW, 20 octets on all architectures.
>
>> This will break old log files that have
>> a packet header of 24 bytes.
>
> The rp3 log files would have 20 on 32-bit and 24 on 64-bit. The only
> way to fix is to make a break. I intend to introduce new rp4 codes,
> and adjust rplcvt.c.
>
>> The problem appears to be only with a couple of buggy GCC versions. The
>> gcc (Debian 4.7.2-5) 4.7.2 does not have this problem.
>
> This is not a GCC problem at all. It was PEBKAC to assume that rpltime
> would never have any padding at the end.
>
>

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