Re: [patch] gdbserver regcache fetch all regs

[Aleksandar Ristovski <aristovski@qnx.com>]

Doug Evans wrote:
> On Tue, Jun 16, 2009 at 6:24 PM, Aleksandar Ristovski<aristovski@qnx.com> wrote:
>> Hello,
>>
>> I believe this is a bug in gdbserver/regcache.c
>>
>> Current code fetches regno 0 and marks regcache valid. I believe correct
>> should be: fetch all regs, and mark regache valid.
>> [...];
>> ChangeLog:
>>
>>
>> * regcache.c (get_regcache): Fetch all registers instead of
>> regno 0 only.
>>
> 
> Hi.  At first I thought "Yikes!". :-)
> But it turns out that all fetch_registers routines treat 0 and -1 equivalently.
> I wouldn't hold up this patch (it's fine with me fwiw), though I would
> change the ChangeLog entry to something like: "Use -1 instead of 0 to
> fetch all registers." since passing 0 does actually fetch all
> registers.

Very interesting. I see that now, but in target.h it says 
quite unambiguously:

   /* Fetch registers from the inferior process.

      If REGNO is -1, fetch all registers; otherwise, fetch 
at least REGNO.  */

   void (*fetch_registers) (int regno);


> 
> It would be good to remove this oddity and stop the conflation of 0
> and -1, but I don't know what would break.
> We could run the testsuite and see what happens as a start.
> Does anyone know the history behind this?
> 


Thanks,
-- 
Aleksandar Ristovski
QNX Software Systems