Re: prev_pc problem on ia64

["J. Johnston" <jjohnstn@redhat.com>]

Andrew Cagney wrote:
>>>
>>>  > I tried to use target_has_execution but that did not work.  The error
>>>  > I get is that the process does not exist.  The read_pc() routine 
>>> for the ia64 is doing
>>>  > a read_register_pid() and it appears that the inferior_ptid is not 
>>> set up
>>>  > at a time when target_has_execution is set to true.
>>>
>>> target_has_execution doesn't mean that the target is executing. It is
>>> a total misnomer to indicate that the gdb target stratum is capable of
>>> execution. I think what you want is target_has_registers.
>>
> 
> 
>> Arrrgh!  That problem, core file's also has registers ... so right 
>> theory, I've no idea on which thing to use in the test though.
> 
> 
> Hmm, ... but at least target_has_registers should only be true when the 
> target really does have the registers available.  I guess try it.
> 
> Andrew
> 
>

There is a problem in my choice of where to set prev_pc.  The inferior is not guaranteed
to be stopped when init_execution_control_state() is called so ptrace can fail when
asked to fetch the pc register.

I believe I have found a solution that avoids this problem by refreshing prev_pc in proceed()
just prior to resuming.  I will post a patch shortly.

-- Jeff J.