Re: [PATCH] Add a new format letter to dump instructions backward

[Pedro Alves <palves@redhat.com>]

On 01/27/2016 07:49 PM, Paul_Koning@Dell.com wrote:
> 
>> On Jan 27, 2016, at 11:04 AM, Andrew Burgess <andrew.burgess@embecosm.com> wrote:
>>
>> * Toshihito Kikuchi <k.toshihito@yahoo.de> [2016-01-26 05:36:58 +0000]:
>>
>>> To answer the question from Paul, Pedro's guess is correct. I used
>>> symbol's line info to solve a correct frame. And yes, this feature
>>> does not work without debug information unfortunately.
>>
>> If there's no debug information then just looking for symbols in the
>> same section would also be a reasonable guess. Most symbols appear
>> between instructions, not part way through an instruction.
> 
> Yes.  But if you have no symbols either, it can still work on Alpha, or on MIPS if you disregard the Thumb instruction set, or on any number of other RISC machines where every instruction is the same size

Agreed.  We'd probably need to add a gdbarch hook to know whether
the target architecture has variable or fixed length instruction set.
That can always be done as a follow up incremental enhancement, though.

Thanks,
Pedro Alves