[PATCH] Fix "PC register is not available" issue

[Pedro Alves]

On 03/18/2014 05:12 PM, Eli Zaretskii wrote:
>> Date: Tue, 18 Mar 2014 09:54:13 -0700
>> From: Joel Brobecker <brobecker@adacore.com>
>> Cc: gdb-patches@sourceware.org
>>
>>>> Another thought I had on your patch is that we might want to limit
>>>> the warning to situation where the return code is not a permission
>>>> denied.
>>>
>>> I'm not sure we should bother.  After all, if the problem is real, we
>>> will get an error further down the line, when we use the handle to
>>> that thread to do something with it.
>>>
>>> IOW, I see no need to thrash the entire session because of something
>>> that isn't fatal.
>>
>> I didn't mean to change the behavior - only hide the warning.
> 
> Ah, OK.  I think I'll do that in the next version of the patch.
> 
>> I think the only part we need to look at before putting your patch
>> in is analyzing its side-effects.
> 
> I'll look into that and post the results.

I see that the GetThreadContext call (do_windows_fetch_inferior_registers)
doesn't check for errors (I think it should (*)).  It'd be interesting to know whether gdb can
actually read the registers off of this thread, and if so, what's the
thread's backtrace like.

(*) - note the other place that calls GetThreadContext does it under
a CHECK:
      CHECK (GetThreadContext (th->h, &th->context));
-- 
Pedro Alves