Re: [PATCH] [ARM] Improve heuristic to guess the instruction state for the next PC when single-stepping

[Doug Evans <dje@google.com>]

On Thu, Mar 4, 2010 at 5:39 AM, Daniel Jacobowitz <dan@codesourcery.com> wrote:
> On Thu, Mar 04, 2010 at 11:48:47AM +0000, Matthew Gretton-Dann wrote:
>> This patch attempts to fix this by seeing if arm_pc_is_thumb () is being
>> asked about the address we will end up at if we execute the instruction
>> at the current PC.  If so it 'executes' the current instruction to see
>> if it will change state, and uses this information to determine the
>> return value.
>
> This is a cute approach.  I can't think of any potential problems with
> it, so I'll commit your patch.
>
>> 2010-03-04  Matthew Gretton-Dann  <matthew.gretton-dann@arm.com>
>>
>>       * arm-tdep.c (arm_pc_is_thumb): Add heuristic that tries to get
>>       the state right when single stepping.
>>       (arm_get_next_pc_raw, thumb_get_next_pc_raw): New functions.
>>       Get the next PC along with the instruction state.
>>       (thumb_get_next_pc): Remove.
>>       (arm_get_next_pc): Modified to use arm_get_next_pc_raw ().
>
> At some point we were asked to not use " ()" to indicate functions, so
> I've removed that bit.

Would it be nice to prefer what the hardware says over what the symbol
info says?
[And if the symbol info disagrees flag a warning?]

[The heuristic is done after symbol checks.]