Re: [PATCH 3/3] gdb: add a '-stopped' option to "info threads"

[Pedro Alves <pedro@palves.net>]

Hi!

On 2023-04-05 12:31, Aktemur, Tankut Baris via Gdb-patches wrote:
> On Wednesday, April 5, 2023 12:51 PM, Eli Zaretskii wrote:
>>> From: "Aktemur, Tankut Baris" <tankut.baris.aktemur@intel.com>
>>> Date: Wed, 5 Apr 2023 10:19:26 +0000
>>>
>>> I'm fine if we make the single thread id a special case.
>>
>> Maybe that's all we should do.
>>
>>> But then the question is, where do we draw the line?  If the user
>>> gave just a few thread ids, do we still ignore the flag?  What is
>>> the limit to the acceptable list length?  Because of these
>>> questions, consistently applying the flag made more sense to me.
>>
>> We don't have to be 100% consistent, we just need to be useful.
> 
> Let's please wait a bit in case other maintainers want to chime in.
> I don't have an objection to treating the single thread id case specially.

I don't think we should give single ID any special treatment.  It's as you say,
what about "info thread 1 2 ", does that get an exception because it
is two single IDs?  Why would that be different from "info threads 1-2" ?
What if I put the IDs in a convenience variable, and then do:

 (gdb) eval "info threads -stopped %s", $id

Why should my script behave differently depending on what is saved in $id?

Etc.

BTW, the same rationale should apply to "thread apply".  "info threads" and "thread apply"
have basically the same logic and also share options.  IMO, we should have a matching "thread apply -stopped" too.

And with "thread apply", it is even clearer IMO that "thread apply $ID -stopped print foo" should not
every try to run "print foo" on a not-stopped thread!  From the fact that "info threads" and "thread apply"
should walk the same threads given the same options, it follows that "info threads -stopped" should not walk
any non-stopped thread.

I'll look at later revisions of the series now.  Thanks for doing this.  We had talked about it a while ago but
I hadn't realized you had sent it upstream.  Thanks!

Pedro Alves