[PATCH] sim: don't rely on inferior_ptid in gdbsim_target::wait

[Pedro Alves]

On 1/20/20 12:48 AM, Simon Marchi wrote:
> On 2020-01-19 4:12 p.m., Andrew Burgess wrote:
>> * Simon Marchi <simon.marchi@polymtl.ca> [2020-01-18 22:55:57 -0500]:
>>
>>> When running a program with the simulator target, I get:
>>>
>>>     /home/simark/src/binutils-gdb/gdb/inferior.c:279: internal-error: inferior* find_inferior_pid(process_stratum_target*, int): Assertion `pid != 0' failed.
>>>
>>> This can be reproduced by building a GDB for --target=arm-none-gnueabi,
>>> and running with
>>>
>>>     $ ./gdb -nx --data-directory=data-directory a.out -ex "target sim" -ex load -ex "b main" -ex r
>>>
>>> Where a.out is any program with a main.
>>>
>>> The problem is that gdbsim_target::wait assumes that inferior_ptid has
>>> the value of the thread it wants to report an event for.
>>>
>>> Actually, it's the target's responsibility to come up with the ptid of
>>> the thread the event is for.  In the sim target, that ptid is stored in
>>> sim_inferior_data::remote_sim_ptid, so return that instead of
>>> inferior_ptid.
>>>
>>> ChangeLog:
>>>
>>> 	* remote-sim.c (gdbsim_target::wait): Return
>>> 	sim_data->remote_sim_ptid instead of inferior_ptid.
>>
>> This makes sense.  LGTM.
>>
>> Thanks,
>> Andrew
> 
> Thanks, I pushed it.

Thanks for doing this.  This was a recent assertion I added with
the multi-target work.  It's possibly (and likely) that other ports
will need similar adjustments, but it's hard to tell with actually
running into the issue.

Thanks,
Pedro Alves