This commit fixes a 8.1->8.2 regression exposed by
gdb.python/py-evthreads.exp when testing with
--target_board=native-gdbserver.
gdb.log shows:
src/gdb/thread.c:93: internal-error: thread_info* inferior_thread(): Assertion `tp' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n) FAIL: gdb.python/py-evthreads.exp: run to breakpoint 1 (GDB internal error)
A backtrace shows (frames #2 and #10 highlighted) that the assertion
fails when GDB is setting up the connection to the remote target, in
non-stop mode:
#0 0x0000000000622ff0 in internal_error(char const*, int, char const*, ...) (file=0xc1ad98 "src/gdb/thread.c", line=93, fmt=0xc1ad20 "%s: Assertion `%s' failed.") at src/gdb/common/errors.c:54
#1 0x000000000089567e in inferior_thread() () at src/gdb/thread.c:93
= #2 0x00000000004da91d in get_event_thread() () at src/gdb/python/py-threadevent.c:38
#3 0x00000000004da9b7 in create_thread_event_object(_typeobject*, _object*) (py_type=0x11574c0 <continue_event_object_type>, thread=0x0)
at src/gdb/python/py-threadevent.c:60
#4 0x00000000004bf6fe in create_continue_event_object() () at src/gdb/python/py-continueevent.c:27
#5 0x00000000004bf738 in emit_continue_event(ptid_t) (ptid=...) at src/gdb/python/py-continueevent.c:40
#6 0x00000000004c7d47 in python_on_resume(ptid_t) (ptid=...) at src/gdb/python/py-inferior.c:108
#7 0x0000000000485bfb in std::_Function_handler<void (ptid_t), void (*)(ptid_t)>::_M_invoke(std::_Any_data const&, ptid_t&&) (__functor=..., __args#0=...) at /usr/include/c++/7/bits/std_function.h:316
#8 0x000000000089b416 in std::function<void (ptid_t)>::operator()(ptid_t) const (this=0x12aa600, __args#0=...)
at /usr/include/c++/7/bits/std_function.h:706
#9 0x000000000089aa0e in gdb::observers::observable<ptid_t>::notify(ptid_t) const (this=0x118a7a0 <gdb::observers::target_resumed>, args#0=...)
at src/gdb/common/observable.h:106
= #10 0x0000000000896fbe in set_running(ptid_t, int) (ptid=..., running=1) at src/gdb/thread.c:880
#11 0x00000000007f750f in remote_target::remote_add_thread(ptid_t, bool, bool) (this=0x12c5440, ptid=..., running=true, executing=true) at src/gdb/remote.c:2434
#12 0x00000000007f779d in remote_target::remote_notice_new_inferior(ptid_t, int) (this=0x12c5440, currthread=..., executing=1)
at src/gdb/remote.c:2515
#13 0x00000000007f9c44 in remote_target::update_thread_list() (this=0x12c5440) at src/gdb/remote.c:3831
#14 0x00000000007fb922 in remote_target::start_remote(int, int) (this=0x12c5440, from_tty=0, extended_p=0)
at src/gdb/remote.c:4655
#15 0x00000000007fd102 in remote_target::open_1(char const*, int, int) (name=0x1a4f45e "localhost:2346", from_tty=0, extended_p=0)
at src/gdb/remote.c:5638
#16 0x00000000007fbec1 in remote_target::open(char const*, int) (name=0x1a4f45e "localhost:2346", from_tty=0)
at src/gdb/remote.c:4862
So on frame #10, we're marking a newly-discovered thread as running,
and that causes the Python API to emit a gdb.ContinueEvent.
gdb.ContinueEvent is a gdb.ThreadEvent, and as such includes the event
thread as the "inferior_thread" attribute. The problem is that when
we get to frame #3/#4, we lost all references to the thread that is
being marked as running. create_continue_event_object assumes that it
is the current thread, which is not true in this case.
Fix this by passing down the right thread in
create_continue_event_object. Also remove
create_thread_event_object's default argument and have the only other
caller left pass down the right thread explicitly too.
gdb/ChangeLog:
2018-08-24 Pedro Alves <palves@redhat.com>
Simon Marchi <simon.marchi@ericsson.com>
PR gdb/23379
* python/py-continueevent.c: Include "gdbthread.h".
(create_continue_event_object): Add intro comment. Add 'ptid'
parameter. Use it to find thread to pass to
create_thread_event_object.
(emit_continue_event): Pass PTID down to
create_continue_event_object.
* python/py-event.h (py_get_event_thread): Declare.
(create_thread_event_object): Remove default from 'thread'
parameter.
* python/py-stopevent.c (create_stop_event_object): Use
py_get_event_thread.
* python/py-threadevent.c (get_event_thread): Rename to ...
(py_get_event_thread): ... this, make extern, add 'ptid' parameter
and use it to find the thread.
(create_thread_event_object): Assert that THREAD isn't null.
Don't find the event thread here.
da3c873831