From: Tom Tromey <tom@tromey.com>
To: Andrew Burgess via Gdb-patches <gdb-patches@sourceware.org>
Cc: Andrew Burgess <aburgess@redhat.com>
Subject: Re: [PATCHv3 7/7] gdb: some process_stratum_target should not be shared
Date: Fri, 18 Nov 2022 11:04:28 -0700 [thread overview]
Message-ID: <87fsegqgur.fsf@tromey.com> (raw)
In-Reply-To: <577f2c47793acb501c2611c0e6c7ea379f774830.1668789658.git.aburgess@redhat.com> (Andrew Burgess via Gdb-patches's message of "Fri, 18 Nov 2022 16:42:58 +0000")
>>>>> "Andrew" == Andrew Burgess via Gdb-patches <gdb-patches@sourceware.org> writes:
Andrew> For things like the Linux and FreeBSD native targets, as well as the
Andrew> remote target, this is absolutely true (or was made true). But some
Andrew> targets were never updated to be shareable, for example, the
Andrew> core_target, which is used when reading core-files, stores some of its
Andrew> state in the program_space, but also, the core-file and the executable
Andrew> being debugged are closely related.
Andrew> As each add-inferior call creates an inferior with a new
Andrew> program_space, and doesn't automatically copy the executable, or the
Andrew> current core-file, I don't think it really makes sense to "share"
Andrew> core_target objects between inferiors.
Yeah, probably the core target just doesn't even make sense to share.
I guess if we did want to share it, we could move the state into the
core target. Maybe this is worthwhile to do anyway? I see a bunch of
uses of core_bfd (which is a #define reaching into the program space),
but some, e.g. in linux_read_core_file_mappings, seem like they could be
replaced with a parameter.
Andrew> I think this behaviour might be confusing, so I'd like to have GDB not
Andrew> initially share the core connection. Instead, when the user tries to
Andrew> add the new inferior a warning is given, and the new inferior is
Andrew> created without a connection, like this:
This makes sense to me.
Andrew> + /* The core_target only works for the inferior in which it was initially
Andrew> + opened, and can't be copied to some other inferior's target_stack. */
Andrew> + bool is_shareable () override
Andrew> + { return false; }
However, why only mark the core target this way?
I think there are a lot of other targets that can't be
shared... remote-sim, all the trace targets, even I think windows-nat,
since it isn't multi-inferior-capable yet.
So maybe the default implementation should be 'return false' and then
specific known-good targets should override it?
Tom
next prev parent reply other threads:[~2022-11-18 19:05 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-21 13:12 [PATCH] gdb: fix target_ops reference count for some cases Andrew Burgess
2022-09-21 15:30 ` Simon Marchi
2022-09-22 14:21 ` Andrew Burgess
2022-09-22 14:52 ` Simon Marchi
2022-09-22 15:00 ` Simon Marchi
2022-09-22 17:24 ` Andrew Burgess
2022-09-26 14:16 ` Simon Marchi
2022-10-01 20:58 ` Andrew Burgess
2022-10-02 17:04 ` [PATCHv2 0/7] " Andrew Burgess
2022-10-02 17:04 ` [PATCHv2 1/7] gdb/remote: remove some manual reference count handling Andrew Burgess
2022-10-02 17:04 ` [PATCHv2 2/7] gdb: remove decref_target Andrew Burgess
2022-10-02 17:04 ` [PATCHv2 3/7] gdb: have target_stack automate reference count handling Andrew Burgess
2022-10-02 17:04 ` [PATCHv2 4/7] gdb: remove the pop_all_targets (and friends) global functions Andrew Burgess
2022-10-05 20:49 ` Lancelot SIX
2022-10-06 11:14 ` Andrew Burgess
2022-10-02 17:04 ` [PATCHv2 5/7] gdb: ensure all targets are popped before an inferior is destructed Andrew Burgess
2022-10-02 17:04 ` [PATCHv2 6/7] gdb/maint: add core file name to 'maint info program-spaces' output Andrew Burgess
2022-10-02 17:21 ` Eli Zaretskii
2022-10-02 17:04 ` [PATCHv2 7/7] gdb: some process_stratum_target should not be shared Andrew Burgess
2022-10-02 17:21 ` Eli Zaretskii
2022-10-05 21:15 ` Lancelot SIX
2022-10-06 11:44 ` Andrew Burgess
2022-11-18 16:42 ` [PATCHv3 0/7] gdb: fix target_ops reference count for some cases Andrew Burgess
2022-11-18 16:42 ` [PATCHv3 1/7] gdb/remote: remove some manual reference count handling Andrew Burgess
2022-11-18 16:42 ` [PATCHv3 2/7] gdb: remove decref_target Andrew Burgess
2022-11-18 17:22 ` Tom Tromey
2022-11-18 16:42 ` [PATCHv3 3/7] gdb: have target_stack automate reference count handling Andrew Burgess
2022-11-18 17:25 ` Tom Tromey
2022-11-18 16:42 ` [PATCHv3 4/7] gdb: remove the pop_all_targets (and friends) global functions Andrew Burgess
2022-11-18 17:29 ` Tom Tromey
2022-11-18 16:42 ` [PATCHv3 5/7] gdb: ensure all targets are popped before an inferior is destructed Andrew Burgess
2022-11-18 16:42 ` [PATCHv3 6/7] gdb/maint: add core file name to 'maint info program-spaces' output Andrew Burgess
2022-11-18 17:03 ` Eli Zaretskii
2022-11-18 16:42 ` [PATCHv3 7/7] gdb: some process_stratum_target should not be shared Andrew Burgess
2022-11-18 17:02 ` Eli Zaretskii
2022-11-18 18:04 ` Tom Tromey [this message]
2022-12-14 13:57 ` Andrew Burgess
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