Re: [PATCH] Python API: Add gdb.is_in_prologue and gdb.is_in_epilogue.

[Doug Evans <dje@google.com>]

On Fri, Oct 24, 2014 at 8:34 AM, Ulrich Weigand <uweigand@de.ibm.com> wrote:
> Pedro Alves wrote:
>> On 10/24/2014 05:57 AM, Doug Evans wrote:
>> > If one went that route then I wonder whether we need two API functions.
>> > [If we did go with only one function I'd choose a different name than
>> > foo_destroyed of course.]
>>
>> Do you have a better suggestion for the gdbarch hook?  I think we
>> should just rename it for good, avoiding these confusions further.
>
> So if the only use of this interface is to check whether the result of
> some other interface (I assume something like Frame.read_var ?) is
> reliable, then I guess we might consider moving the check actually
> into that other interface.  E.g. have Frame.read_var itself check
> in_epilogue and return an unavailable or optimized-out value if
> the value would be unreliable otherwise.

I can imagine someone wanting to do the check before doing
gdb.parse_and_eval (an escape hatch for general expression
evaluation).

Also, FAOD, the API function in question still should check whether
the pc is in the prologue (unless, e.g., gdb knows the debug info is
usable) as there too locals may not be accessible.