Mark Kettenis wrote:
>> Date: Sun, 6 Mar 2011 15:15:16 +0100
>> From: Jan Kratochvil <jan.kratochvil@redhat.com>
>>
>> On Fri, 04 Mar 2011 22:37:52 +0100, Michael Snyder wrote:
>>> Call error if target_read_memory fails.
>> [...]
>>> -  target_read_memory (pc, &op, 1);
>>> +  if (target_read_memory (pc, &op, 1))
>>> +    error (_("Couldn't read memory at pc (%s)"), 
>>> +	   paddress (gdbarch, pc));
>> There is the function `read_memory' for such purpose.
> 
> But read_memory() will throw an exception if reading fails.  That is
> not necessarily what we want here.  In fact, most of these reads
> should silently fail.  They are part of the prologue analysis code,
> which to some of extent is based on heuristics.  And one of the
> heristics here is that if we fail to read an instruction at a certain
> address, we're no longer looking at a function prologue.  Higher level
> code will try an alternative strategy or issue an error message.
> Spamming the user with more error messages isn't going to be terribly
> helpful.
> 
> But Michael is right that there is an issue here.  The code is relying
> on uninitialized stack variables not matching the specific opcodes we
> check against.  I think most of the:
> 
>     target_read_memory(pc, &op, 1);
> 
> statements, should be replaced with
> 
>     if (target_read_memory(pc, &op, 1))
>       return pc;
> 
> Cheers,
> 
> Mark

Thanks.  So changed.  Will you give it an eyeball?
Michael