From: Lancelot SIX <Lancelot.Six@amd.com>
To: Simon Marchi <simon.marchi@polymtl.ca>,
Simon Marchi <simon.marchi@efficios.com>
Cc: gdb-patches@sourceware.org
Subject: Re: [PATCH 4/24] gdb: replace some so_list parameters to use references
Date: Thu, 19 Oct 2023 16:20:06 +0100 [thread overview]
Message-ID: <305175fd-a8d4-43f6-b6d2-8cab2aaff7a0@amd.com> (raw)
In-Reply-To: <560f3443-5089-4af2-94d5-efc7bbd92684@polymtl.ca>
>>> - void on_solib_loaded (so_list *so) override;
>>> - void on_solib_unloaded (so_list *so) override;
>>> + void on_solib_loaded (const so_list &so) override;
>>> + void on_solib_unloaded (const so_list &so) override;
>>
>> It is orthogonal to this change, but it would make sense for those
>> methods to be const as well.
>>
>> Doing this requires interp::interp_ui_out to be const as well (as done
>> in attached patch).
>
> Why do you think the interp object should be const (which is the effect
> of marking the methods const)? These methods are notifiers to let the
> interp know about certain events that occured. Whether they should
> modify the state of the interpreter or not is up to the particular
> implementation of the interpreter. Perhaps you're right, but I don't
> see it.
>
It is just that current interps (MI really) are just forwarding
notifications. The event does not change the interp's state.
Does it has to be const? No. But usually I tend to make things const
unless there is a reason not to. That's all.
That being said, making only those const would become quite
inconsistent with the rest of the interface. So in the end, that was
not a good idea!
> In your patch, you make interp::interp_ui_out const, but it still
> returns a non-const ui_out. So when outputting something, the
> interpreter itself is not modified, but the ui_out behind it is. I
> presume (sometimes) the ui_out needs to be non-const, since for things
> like pagination it clearly needs to keep a state. Design-wise, is it
> "correct" to make a const intepreter able to return a non-const ui_out?
>
I don't necessarily see that as an issue, the ui_out might need to
maintain its own state.
Anyway, since it is not really desirable to change this part of the
interface, I think this comment can be discarded.
>>> void on_about_to_proceed () override;
>>> void on_traceframe_changed (int tfnum, int tpnum) override;
>>> void on_tsv_created (const trace_state_variable *tsv) override;
>>> diff --git a/gdb/observable.h b/gdb/observable.h
>>> index acb05e9b535c..5ed6ca547ce0 100644
>>> --- a/gdb/observable.h
>>> +++ b/gdb/observable.h
>>> @@ -99,13 +99,12 @@ extern observable<inferior */* parent_inf */, inferior */* child_inf */,
>>> /* The shared library specified by SOLIB has been loaded. Note that
>>> when gdb calls this observer, the library's symbols probably
>>> haven't been loaded yet. */
>>> -extern observable<struct so_list */* solib */> solib_loaded;
>>> +extern observable<so_list &/* solib */> solib_loaded;
>>
>> I am wondering, is there a reason to make the solib parameter const for
>> solib_unloaded but not for solib_loaded?
>>
>> Changing it to const seems to still compile just fine. If down the line
>> an observer needs to modify the SO, the observer's signature can be
>> adjusted.
>
> Just pragmatic reasons. Do you build with --enable-targets=all?
>
> It's because bsd_uthread_solib_loaded calls solib_read_symbols to read
> in the symbols of the library it is looking for, and that requires a
> non-const so_list.
>
Ah, indeed, my current build tree does not have --enable-targets=all,
thanks. Having a user requiring a non-const ref is a good reason.
Thanks,
Lancelot.
next prev parent reply other threads:[~2023-10-19 15:20 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-10 20:39 [PATCH 00/24] C++ification of struct so_list Simon Marchi
2023-10-10 20:39 ` [PATCH 01/24] gdb: remove empty clear_solib functions Simon Marchi
2023-10-10 20:39 ` [PATCH 02/24] gdb: add program_space parameter to target_so_ops::clear_solib Simon Marchi
2023-10-17 14:57 ` Pedro Alves
2023-10-17 15:19 ` Simon Marchi
2023-10-10 20:39 ` [PATCH 03/24] gdb: make interps_notify work with references Simon Marchi
2023-10-11 8:48 ` Lancelot SIX
2023-10-11 14:18 ` Simon Marchi
2023-10-10 20:39 ` [PATCH 04/24] gdb: replace some so_list parameters to use references Simon Marchi
2023-10-19 11:07 ` [PATCH 4/24] " Lancelot SIX
2023-10-19 14:49 ` Simon Marchi
2023-10-19 15:20 ` Lancelot SIX [this message]
2023-10-19 16:07 ` Simon Marchi
2023-10-10 20:40 ` [PATCH 05/24] gdbsupport: use "reference" and "pointer" type aliases in intrusive_list Simon Marchi
2023-10-10 20:40 ` [PATCH 06/24] gdbsupport: make intrusive_list's disposer accept a reference Simon Marchi
2023-10-12 19:05 ` Pedro Alves
2023-10-14 20:12 ` Simon Marchi
2023-10-10 20:40 ` [PATCH 07/24] gdb: make get_cbfd_soname_build_id static Simon Marchi
2023-10-10 20:40 ` [PATCH 08/24] gdb: allocate so_list with new, deallocate with delete Simon Marchi
2023-10-10 20:40 ` [PATCH 09/24] gdb: rename lm_info_base to lm_info Simon Marchi
2023-10-10 20:40 ` [PATCH 10/24] gdb: remove target_so_ops::free_so Simon Marchi
2023-10-10 20:40 ` [PATCH 11/24] gdb: use gdb::checked_static_cast when casting lm_info Simon Marchi
2023-10-10 20:40 ` [PATCH 12/24] gdb: make solib-svr4 not use so_list internally Simon Marchi
2023-10-13 17:52 ` Lancelot SIX
2023-10-14 19:59 ` Simon Marchi
2023-10-19 11:08 ` Lancelot SIX
2023-10-19 14:50 ` Simon Marchi
2023-10-10 20:40 ` [PATCH 13/24] gdb: make solib-rocm " Simon Marchi
2023-10-13 18:35 ` Lancelot SIX
2023-10-14 20:00 ` Simon Marchi
2023-10-17 15:23 ` Pedro Alves
2023-10-17 15:32 ` Simon Marchi
2023-10-10 20:40 ` [PATCH 14/24] gdb: remove lm_info_vector typedef Simon Marchi
2023-10-10 20:40 ` [PATCH 15/24] gdb: make so_list::lm_info a unique_ptr Simon Marchi
2023-10-10 20:40 ` [PATCH 16/24] gdb: make clear_so a method of struct so_list Simon Marchi
2023-10-19 11:08 ` Lancelot SIX
2023-10-19 14:52 ` Simon Marchi
2023-10-10 20:40 ` [PATCH 17/24] gdb: remove target_section_table typedef Simon Marchi
2023-10-10 20:40 ` [PATCH 18/24] gdb: make so_list::sections not a pointer Simon Marchi
2023-10-10 20:40 ` [PATCH 19/24] gdb: make so_list::abfd a gdb_bfd_ref_ptr Simon Marchi
2023-10-10 20:40 ` [PATCH 20/24] gdb: make so_list::{so_original_name,so_name} std::strings Simon Marchi
2023-10-13 22:28 ` [PATCH 20/24] gdb: make so_list::{so_original_name, so_name} std::strings Lancelot SIX
2023-10-14 20:01 ` Simon Marchi
2023-10-19 11:08 ` [PATCH 20/24] gdb: make so_list::{so_original_name,so_name} std::strings Lancelot SIX
2023-10-19 14:55 ` Simon Marchi
2023-10-10 20:40 ` [PATCH 21/24] gdb: link so_list using intrusive_list Simon Marchi
2023-10-17 19:14 ` Pedro Alves
2023-10-17 19:38 ` Simon Marchi
2023-10-10 20:40 ` [PATCH 22/24] gdb: don't call so_list::clear in free_so Simon Marchi
2023-10-10 20:40 ` [PATCH 23/24] gdb: remove free_so function Simon Marchi
2023-10-10 20:49 ` [PATCH 24/24] gdb: rename struct so_list to so Simon Marchi
2023-10-17 19:20 ` [PATCH 00/24] C++ification of struct so_list Pedro Alves
2023-10-17 19:53 ` Simon Marchi
2023-10-20 14:40 ` Pedro Alves
2023-10-19 11:09 ` [PATCH 0/24] " Lancelot SIX
2023-10-19 14:57 ` Simon Marchi
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