When GDB finds out the target triggered a watchpoint, and the target
has non-continuable watchpoints, GDB sets things up to step past the
instruction that triggered the watchpoint. This is just like stepping
past a breakpoint, but goes through a different mechanism - it resumes
only the thread that needs to step past the watchpoint, but also
switches a "infwait state" global, that has the effect that the next
target_wait only wait for events only from that thread.
This forcing of a ptid to pass to target_wait obviously becomes a
bottleneck if we ever support stepping past different watchpoints
simultaneously (in separate processes).
It's also unnecessary -- the target should only return events for
threads that have been resumed; if no other thread than the one we're
stepping past the watchpoint has been resumed, then those other
threads should not report events. If we couldn't assume that, then
stepping past regular breakpoints would be broken for not likewise
forcing a similar infwait_state.
So this patch eliminates infwait_state, and instead teaches keep_going
to mark step_over_info in a way that has the breakpoints module skip
inserting watchpoints (because we're stepping past one), like it skips
breakpoints when we're stepping past one.
Tested on:
- x86_64 Fedora 20 (continuable watchpoints)
- PPC64 Fedora 18 (non-steppable watchpoints)
gdb/
2014-10-15 Pedro Alves <palves@redhat.com>
* breakpoint.c (should_be_inserted): Don't insert watchpoints if
trying to step past a non-steppable watchpoint.
* gdbthread.h (struct thread_info) <stepping_over_watchpoint>: New
field.
* infrun.c (struct step_over_info): Add new field
'nonsteppable_watchpoint_p' and adjust comments.
(set_step_over_info): New 'nonsteppable_watchpoint_p' parameter.
Adjust.
(clear_step_over_info): Clear nonsteppable_watchpoint_p as well.
(stepping_past_nonsteppable_watchpoint): New function.
(step_over_info_valid_p): Also return true if stepping past a
nonsteppable watchpoint.
(proceed): Adjust call to set_step_over_info. Remove reference to
init_infwait_state.
(init_wait_for_inferior): Remove reference to init_infwait_state.
(waiton_ptid): Delete global.
(struct execution_control_state)
<stepped_after_stopped_by_watchpoint>: Delete field.
(wait_for_inferior, fetch_inferior_event): Always pass
minus_one_ptid to target_wait.
(init_thread_stepping_state): Clear 'stepping_over_watchpoint'
field.
(init_infwait_state): Delete function.
(handle_inferior_event): Remove infwait_state handling.
(handle_signal_stop) <watchpoints handling>: Adjust after
stepped_after_stopped_by_watchpoint removal. Don't remove
breakpoints here nor set infwait_state. Set the thread's
stepping_over_watchpoint flag, and call keep_going instead.
(keep_going): Handle stepping_over_watchpoint. Adjust
set_step_over_info calls.
* infrun.h (stepping_past_nonsteppable_watchpoint): Declare
function.
... instead of trap_expected.
Gets rid of one singlestep_breakpoints_inserted_p reference, and is
generally more to the point.
gdb/
2014-10-15 Pedro Alves <palves@redhat.com>
* infrun.c (step_over_info_valid_p): New function.
(resume): Use step_over_info_valid_p instead of checking the
threads's trap_expected flag.
On 32-bit S390 targets the longjmp target address "naturally" has the
most significant bit set. That bit indicates the addressing mode and
is not part of the address itself. Thus, in analogy with similar
cases (like when computing the caller PC in
insert_step_resume_breakpoint_at_caller), this change removes
non-address bits from the longjmp target address before using it as a
breakpoint address.
Note that there are two ways for determining the longjmp target
address: via a probe or via a gdbarch method. This change only
affects the probe method, because it is assumed that the address
returned by the gdbarch method is usable as-is.
This change was tested together with a patch that enables longjmp
probes in glibc for S/390:
https://sourceware.org/ml/libc-alpha/2014-10/msg00277.html
gdb/ChangeLog:
* gdb/infrun.c (process_event_stop_test): Apply
gdbarch_addr_bits_remove to longjmp resume address.
As a result of commit b57bacec, local variable 'printed' is no longer
used. This patch is to remove it.
gdb:
2014-10-09 Yao Qi <yao@codesourcery.com>
* infrun.c (handle_signal_stop): Remove local variable 'printed'.
Commit a25a5a45 (Fix "breakpoint always-inserted off"; remove
"breakpoint always-inserted auto") regressed non-stop remote
debugging.
This was exposed by mi-nsintrall.exp intermittently failing with a
spurious SIGTRAP.
The problem is that when debugging with "target remote", new threads
the target has spawned but have never reported a stop aren't visible
to GDB until it explicitly resyncs its thread list with the target's.
For example, in a program like this:
int
main (void)
{
pthread_t child_thread;
pthread_create (&child_thread, NULL, child_function, NULL);
return 0; <<<< set breakpoint here
}
If the user sets a breakpoint at the "return" statement, and runs the
program, when that breakpoint hit is reported, GDB is only aware of
the main thread. So if we base the decision to remove or insert
breakpoints from the target based on whether all the threads we know
about are stopped, we'll miss that child_thread is running, and thus
we'll remove breakpoints from the target, even through they should
still remain inserted, otherwise child_thread will miss them.
The break-while-running.exp test actually should also be exposing this
thread-list-out-of-synch problem. That test sets a breakpoint while
the main thread is stopped, but other threads are running. Because
other threads are running, the breakpoint is supposed to be inserted
immediately. But, unless something forces a refetch of the thread
list, like, e.g., "info threads", GDB won't be aware of the other
threads that had been spawned by the main thread, and so won't insert
new or old breakpoints in the target. And it turns out that the test
is exactly doing an explicit "info threads", masking out the
problem... This commit adjust the test to exercise the case of not
issuing "info threads". The test then fails without the GDB fix.
In the ni-nsintrall.exp case, what happens is that several threads hit
the same breakpoint, and when the first thread reports the stop,
because GDB wasn't aware other threads exist, all threads known to GDB
are found stopped, so GDB removes the breakpoints from the target.
The other threads follow up with SIGTRAPs too for that same
breakpoint, which has already been removed. For the first few
threads, the moribund breakpoints machinery suppresses the SIGTRAPs,
but after a few events (precisely '3 * thread_count () + 1' at the
time the breakpoint was removed, see update_global_location_list), the
moribund breakpoint machinery is no longer aware of the removed
breakpoint, and the SIGTRAP is reported as a spurious stop.
The fix is naturally then to stop assuming that if no thread in the
list is executing, then the target is fully stopped. We can't know
that until we fully sync the thread list. Because updating the thread
list on every stop would be too much RSP traffic, I chose instead to
update it whenever we're about to present a stop to the user.
Actually updating the thread list at that point happens to be an item
I had added to the local/remote parity wiki page a while ago:
Native GNU/Linux debugging adds new threads to the thread list as
the program creates them "The [New Thread foo] messages". Remote
debugging can't do that, and it's arguable whether we shouldn't even
stop native debugging from doing that, as it hinders inferior
performance. However, a related issue is that with remote targets
(and gdbserver), even after the program stops, the user still needs
to do "info threads" to pull an updated thread list. This, should
most likely be addressed, so that GDB pulls the list itself, perhaps
just before presenting a stop to the user.
With that in place, the need to delay "Program received signal FOO"
was actually caught by the manythreads.exp test. Without that bit, I
was getting:
[Thread 0x7ffff7f13700 (LWP 4499) exited]
[New Thread 0x7ffff7f0b700 (LWP 4500)]
^C
Program received signal SIGINT, Interrupt.
[New Thread 0x7ffff7f03700 (LWP 4501)] <<< new output
[Switching to Thread 0x7ffff7f0b700 (LWP 4500)]
__GI___nptl_death_event () at events.c:31
31 {
(gdb) FAIL: gdb.threads/manythreads.exp: stop threads 1
That is, I was now getting "New Thread" lines after the "Program
received signal" line, and the test doesn't expect them. As the
number of new threads discovered before and after the "Program
received signal" output is unbounded, it's much nicer to defer
"Program received signal" until after synching the thread list, thus
close to the "switching to thread" output and "current frame/source"
info:
[Thread 0x7ffff7863700 (LWP 7647) exited]
^C[New Thread 0x7ffff786b700 (LWP 7648)]
Program received signal SIGINT, Interrupt.
[Switching to Thread 0x7ffff7fc4740 (LWP 6243)]
__GI___nptl_create_event () at events.c:25
25 {
(gdb) PASS: gdb.threads/manythreads.exp: stop threads 1
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/
2014-10-02 Pedro Alves <palves@redhat.com>
* breakpoint.c (breakpoints_should_be_inserted_now): Use
threads_are_executing.
* breakpoint.h (breakpoints_should_be_inserted_now): Add
describing comment.
* gdbthread.h (threads_are_executing): Declare.
(handle_signal_stop) <random signals>: Don't print about the
signal here if stopping.
(end_stepping_range): Don't notify observers here.
(normal_stop): Update the thread list. If stopped by a random
signal or a stepping range ended, notify observers.
* thread.c (threads_executing): New global.
(init_thread_list): Clear 'threads_executing'.
(set_executing): Set or clear 'threads_executing'.
(threads_are_executing): New function.
(update_threads_executing): New function.
(update_thread_list): Use it.
gdb/testsuite/
2014-10-02 Pedro Alves <palves@redhat.com>
* gdb.threads/break-while-running.exp (test): Add new
'update_thread_list' argument. Skip "info threads" if false.
(top level): Add new 'update_thread_list' axis.
This patch reorganizes the code that implements follow-fork and
detach-on-fork in preparation for implementation of those features for the
extended-remote target. The function linux-nat.c:linux_child_follow_fork
contained target-independent code mixed in with target-dependent code. The
target-independent pieces need to be accessible for the host-side
implementation of follow-fork for extended-remote Linux targets.
The changes are fairly mechanical. A new routine, follow_fork_inferior,
is implemented in infrun.c, containing those parts of
linux_child_follow_fork that manage inferiors and the inferior list. The
parts of linux_child_follow_fork that deal with LWPs and target-specifics
were left in-place. Although the order of some operations was changed, the
resulting functionality was not.
Modifications were made to the other native target follow-fork functions,
inf_ttrace_follow_fork and inf_ptrace_follow_fork, that should allow them
to work with follow_fork_inferior. Some other adjustments were necessary
in inf-ttrace.c. The changes to inf-ttrace.c and inf-ptrace.c were not
tested.
gdb/ChangeLog:
* inf-ptrace.c (inf_ptrace_follow_fork): Remove target-independent
code so as to work with follow_fork_inferior.
* inf-ttrace.c (inf_ttrace_follow_fork): Ditto.
(inf_ttrace_create_inferior): Remove reference to
inf_ttrace_vfork_ppid.
(inf_ttrace_attach): Ditto.
(inf_ttrace_detach): Ditto.
(inf_ttrace_kill): Use current_inferior instead of
inf_ttrace_vfork_ppid.
(inf_ttrace_wait): Eliminate use of inf_ttrace_vfork_ppid, report
TARGET_WAITKIND_VFORK_DONE event, delete HACK that switched the
inferior away from the parent.
* infrun.c (follow_fork): Call follow_fork_inferior instead of
target_follow_fork.
(follow_fork_inferior): New function.
(follow_inferior_reset_breakpoints): Make function static.
* infrun.h (follow_inferior_reset_breakpoints): Remove declaration.
* linux-nat.c (linux_child_follow_fork): Move target-independent
code to infrun.c:follow_fork_inferior.
What matters for this function, is whether the user requested a
"step", for "set scheduler-locking step", not whether GDB is doing an
internal step for some reason.
/* Return a ptid representing the set of threads that we will proceed,
in the perspective of the user/frontend. */
extern ptid_t user_visible_resume_ptid (int step);
Therefore, the check for singlestep_breakpoints_inserted_p is actually
incorrect, and we end up applying schedlock more often on sss targets
than on non-sss targets.
Found by inspection while working on a patch that eliminates the
singlestep_breakpoints_inserted_p global.
Tested on x86_64 Fedora 20 on top of my 'software single-step on x86'
series.
gdb/
2014-09-25 Pedro Alves <palves@redhat.com>
* infrun.c (user_visible_resume_ptid): Don't check
singlestep_breakpoints_inserted_p.
gdb/
2014-09-25 Pedro Alves <palves@redhat.com>
* infrun.c (stepping_past_instruction_at)
(clear_exit_convenience_vars): Point at infrun.h instead of
inferior.h.
(handle_signal_stop): Fix typo.
By default, GDB removes all breakpoints from the target when the
target stops and the prompt is given back to the user. This is useful
in case GDB crashes while the user is interacting, as otherwise,
there's a higher chance breakpoints would be left planted on the
target.
But, as long as any thread is running free, we need to make sure to
keep breakpoints inserted, lest a thread misses a breakpoint. With
that in mind, in preparation for non-stop mode, we added a "breakpoint
always-inserted on" mode. This traded off the extra crash protection
for never having threads miss breakpoints, and in addition is more
efficient if there's a ton of breakpoints to remove/insert at each
user command (e.g., at each "step").
When we added non-stop mode, and for a period, we required users to
manually set "always-inserted on" when they enabled non-stop mode, as
otherwise GDB removes all breakpoints from the target as soon as any
thread stops, which means the other threads still running will miss
breakpoints. The test added by this patch exercises this.
That soon revealed a nuisance, and so later we added an extra
"breakpoint always-inserted auto" mode, that made GDB behave like
"always-inserted on" when non-stop was enabled, and "always-inserted
off" when non-stop was disabled. "auto" was made the default at the
same time.
In hindsight, this "auto" setting was unnecessary, and not the ideal
solution. Non-stop mode does depends on breakpoints always-inserted
mode, but only as long as any thread is running. If no thread is
running, no breakpoint can be missed. The same is true for all-stop
too. E.g., if, in all-stop mode, and the user does:
(gdb) c&
(gdb) b foo
That breakpoint at "foo" should be inserted immediately, but it
currently isn't -- currently it'll end up inserted only if the target
happens to trip on some event, and is re-resumed, e.g., an internal
breakpoint triggers that doesn't cause a user-visible stop, and so we
end up in keep_going calling insert_breakpoints. The test added by
this patch also covers this.
IOW, no matter whether in non-stop or all-stop, if the target fully
stops, we can remove breakpoints. And no matter whether in all-stop
or non-stop, if any thread is running in the target, then we need
breakpoints to be immediately inserted. And then, if the target has
global breakpoints, we need to keep breakpoints even when the target
is stopped.
So with that in mind, and aiming at reducing all-stop vs non-stop
differences for all-stop-on-stop-of-non-stop, this patch fixes
"breakpoint always-inserted off" to not remove breakpoints from the
target until it fully stops, and then removes the "auto" setting as
unnecessary. I propose removing it straight away rather than keeping
it as an alias, unless someone complains they have scripts that need
it and that can't adjust.
Tested on x86_64 Fedora 20.
gdb/
2014-09-22 Pedro Alves <palves@redhat.com>
* NEWS: Mention merge of "breakpoint always-inserted" modes "off"
and "auto" merged.
* breakpoint.c (enum ugll_insert_mode): New enum.
(always_inserted_mode): Now a plain boolean.
(show_always_inserted_mode): No longer handle AUTO_BOOLEAN_AUTO.
(breakpoints_always_inserted_mode): Delete.
(breakpoints_should_be_inserted_now): New function.
(insert_breakpoints): Pass UGLL_INSERT to
update_global_location_list instead of calling
insert_breakpoint_locations manually.
(create_solib_event_breakpoint_1): New, factored out from ...
(create_solib_event_breakpoint): ... this.
(create_and_insert_solib_event_breakpoint): Use
create_solib_event_breakpoint_1 instead of calling
insert_breakpoint_locations manually.
(update_global_location_list): Change parameter type from boolean
to enum ugll_insert_mode. All callers adjusted. Adjust to use
breakpoints_should_be_inserted_now and handle UGLL_INSERT.
(update_global_location_list_nothrow): Change parameter type from
boolean to enum ugll_insert_mode.
(_initialize_breakpoint): "breakpoint always-inserted" option is
now a boolean command. Update help text.
* breakpoint.h (breakpoints_always_inserted_mode): Delete declaration.
(breakpoints_should_be_inserted_now): New declaration.
* infrun.c (handle_inferior_event) <TARGET_WAITKIND_LOADED>:
Remove breakpoints_always_inserted_mode check.
(normal_stop): Adjust to use breakpoints_should_be_inserted_now.
* remote.c (remote_start_remote): Likewise.
gdb/doc/
2014-09-22 Pedro Alves <palves@redhat.com>
* gdb.texinfo (Set Breaks): Document that "set breakpoint
always-inserted off" is the default mode now. Delete
documentation of "set breakpoint always-inserted auto".
gdb/testsuite/
2014-09-22 Pedro Alves <palves@redhat.com>
* gdb.threads/break-while-running.exp: New file.
* gdb.threads/break-while-running.c: New file.
Currently, GDB can pass a signal to the wrong thread in several
different but related scenarios.
E.g., if thread 1 stops for signal SIGFOO, the user switches to thread
2, and then issues "continue", SIGFOO is actually delivered to thread
2, not thread 1. This obviously messes up programs that use
pthread_kill to send signals to specific threads.
This has been a known issue for a long while. Back in 2008 when I
made stop_signal be per-thread (2020b7ab), I kept the behavior -- see
code in 'proceed' being removed -- wanting to come back to it later.
The time has finally come now.
The patch fixes this -- on resumption, intercepted signals are always
delivered to the thread that had intercepted them.
Another example: if thread 1 stops for a breakpoint, the user switches
to thread 2, and then issues "signal SIGFOO", SIGFOO is actually
delivered to thread 1, not thread 2, because 'proceed' first switches
to thread 1 to step over its breakpoint... If the user deletes the
breakpoint before issuing "signal FOO", then the signal is delivered
to thread 2 (the current thread).
"signal SIGFOO" can be used for two things: inject a signal in the
program while the program/thread had stopped for none, bypassing
"handle nopass"; or changing/suppressing a signal the program had
stopped for. These scenarios are really two faces of the same coin,
and GDB can't really guess what the user is trying to do. GDB might
have intercepted signals in more than one thread even (see the new
signal-command-multiple-signals-pending.exp test). At least in the
inject case, it's obviously clear to me that the user means to deliver
the signal to the currently selected thread, so best is to make the
command's behavior consistent and easy to explain.
Then, if the user is trying to suppress/change a signal the program
had stopped for instead of injecting a new signal, but, the user had
changed threads meanwhile, then she will be surprised that with:
(gdb) continue
Thread 1 stopped for signal SIGFOO.
(gdb) thread 2
(gdb) signal SIGBAR
... GDB actually delivers SIGFOO to thread 1, and SIGBAR to thread 2
(with scheduler-locking off, which is the default, because then
"signal" or any other resumption command resumes all threads).
So the patch makes GDB detect that, and ask for confirmation:
(gdb) thread 1
[Switching to thread 1 (Thread 10979)]
(gdb) signal SIGUSR2
Note:
Thread 3 previously stopped with signal SIGUSR2, User defined signal 2.
Thread 2 previously stopped with signal SIGUSR1, User defined signal 1.
Continuing thread 1 (the current thread) with specified signal will
still deliver the signals noted above to their respective threads.
Continue anyway? (y or n)
All these scenarios are covered by the new tests.
Tested on x86_64 Fedora 20, native and gdbserver.
gdb/
2014-07-25 Pedro Alves <palves@redhat.com>
* NEWS: Mention signal passing and "signal" command changes.
* gdbthread.h (struct thread_suspend_state) <stop_signal>: Extend
comment.
* breakpoint.c (until_break_command): Adjust clear_proceed_status
call.
* infcall.c (run_inferior_call): Adjust clear_proceed_status call.
* infcmd.c (proceed_thread_callback, continue_1, step_once)
(jump_command): Adjust clear_proceed_status call.
(signal_command): Warn if other thread that are resumed have
signals that will be delivered. Adjust clear_proceed_status call.
(until_next_command, finish_command)
(proceed_after_attach_callback, attach_command_post_wait)
(attach_command): Adjust clear_proceed_status call.
* infrun.c (proceed_after_vfork_done): Likewise.
(proceed_after_attach_callback): Adjust comment.
(clear_proceed_status_thread): Clear stop_signal if not in pass
state.
(clear_proceed_status_callback): Delete.
(clear_proceed_status): New 'step' parameter. Only clear the
proceed status of threads the command being prepared is about to
resume.
(proceed): If passed in an explicit signal, override stop_signal
with it. Don't pass the last stop signal to the thread we're
resuming.
(init_wait_for_inferior): Adjust clear_proceed_status call.
(switch_back_to_stepped_thread): Clear the signal if it should not
be passed.
* infrun.h (clear_proceed_status): New 'step' parameter.
(user_visible_resume_ptid): Add comment.
* linux-nat.c (linux_nat_resume_callback): Don't check whether the
signal is in pass state.
* remote.c (append_pending_thread_resumptions): Likewise.
* mi/mi-main.c (proceed_thread): Adjust clear_proceed_status call.
gdb/doc/
2014-07-25 Pedro Alves <palves@redhat.com>
Eli Zaretskii <eliz@gnu.org>
* gdb.texinfo (Signaling) <signal command>: Explain what happens
with multi-threaded programs.
gdb/testsuite/
2014-07-25 Pedro Alves <palves@redhat.com>
* gdb.threads/signal-command-handle-nopass.c: New file.
* gdb.threads/signal-command-handle-nopass.exp: New file.
* gdb.threads/signal-command-multiple-signals-pending.c: New file.
* gdb.threads/signal-command-multiple-signals-pending.exp: New file.
* gdb.threads/signal-delivered-right-thread.c: New file.
* gdb.threads/signal-delivered-right-thread.exp: New file.
This patch is to add ptid into dummy_frame and extend frame_id to
dummy_frame_id (which has a ptid field). With this change, GDB uses
dummy_frame_id (thread ptid and frame_id) to find the dummy frames.
Currently, dummy frames are looked up by frame_id, which isn't
accurate in non-stop or multi-process mode. The test case
gdb.multi/dummy-frame-restore.exp shows the problem and this patch can
fix it.
Test dummy-frame-restore.exp makes two inferiors stop at
different functions, say, inferior 1 stops at f1 while inferior 2
stops at f2. Set a breakpoint to a function, do the inferior call
in two inferiors, and GDB has two dummy frames of the same frame_id.
When the inferior call is finished, GDB will look up a dummy frame
from its stack/list and restore the inferior's regcache. Two
inferiors are finished in different orders, the inferiors' states are
restored differently, which is wrong. Running dummy-frame-restore.exp
under un-patched GDB, we'll get two fails:
FAIL: gdb.multi/dummy-frame-restore.exp: inf 2 first: after infcall: bt in inferior 2
FAIL: gdb.multi/dummy-frame-restore.exp: inf 2 first: after infcall: bt in inferior 1
With this patch applied, GDB will choose the correct dummy_frame to
restore for a given inferior, because ptid is considered when looking up
dummy frames. Two fails above are fixed.
Regression tested on x86_64-linux, both native and gdbserver.
gdb:
2014-06-27 Yao Qi <yao@codesourcery.com>
* breakpoint.c (check_longjmp_breakpoint_for_call_dummy):
Change parameter type to 'struct thread_info *'. Caller
updated.
* breakpoint.h (check_longjmp_breakpoint_for_call_dummy):
Update declaration.
* dummy-frame.c (struct dummy_frame_id): New.
(dummy_frame_id_eq): New function.
(struct dummy_frame) <id>: Change its type to 'struct
dummy_frame_id'.
(dummy_frame_push): Add parameter ptid and save it in
dummy_frame_id.
(pop_dummy_frame_bpt): Use ptid of dummy_frame instead of
inferior_ptid.
(pop_dummy_frame): Assert that the ptid of dummy_frame equals
to inferior_ptid.
(lookup_dummy_frame): Change parameter type to 'struct
dummy_frame_id *'. Callers updated. Call dummy_frame_id_eq
instead of frame_id_eq.
(dummy_frame_pop): Add parameter ptid. Callers updated.
Update comments. Compose dummy_frame_id and pass it to
lookup_dummy_frame.
(dummy_frame_discard): Add parameter ptid.
(dummy_frame_sniffer): Compose dummy_frame_id and call
dummy_frame_id_eq instead of frame_id_eq.
(fprint_dummy_frames): Print ptid.
* dummy-frame.h: Remove comments.
(dummy_frame_push): Add ptid in declaration.
(dummy_frame_pop, dummy_frame_discard): Likewise.
gdb/testsuite:
2014-06-27 Yao Qi <yao@codesourcery.com>
* gdb.multi/dummy-frame-restore.exp: New.
* gdb.multi/dummy-frame-restore.c: New.
gdb/doc:
2014-06-27 Yao Qi <yao@codesourcery.com>
* gdb.texinfo (Maintenance Commands): Update the output of
'maint print dummy-frames' command.
When I read the code, I happen to see this:
signal_pass = (unsigned char *)
xmalloc (sizeof (signal_program[0]) * numsigs);
^^^^^^^^^^^^^^
It is a typo, and this patch is to fix it.
gdb:
2014-06-26 Yao Qi <yao@codesourcery.com>
* infrun.c (_initialize_infrun): Replace "signal_program[0]"
with "signal_pass[0]" in the initialization of signal_pass.
Running gdb.threads/thread-execl.exp with scheduler-locking set to
"step" reveals a problem:
(gdb) next^M
[Thread 0x7ffff7fda700 (LWP 27168) exited]^M
[New LWP 27168]^M
[Thread 0x7ffff74ee700 (LWP 27174) exited]^M
process 27168 is executing new program: /home/jkratoch/redhat/gdb-clean/gdb/testsuite/gdb.threads/thread-execl^M
[Thread debugging using libthread_db enabled]^M
Using host libthread_db library "/lib64/libthread_db.so.1".^M
infrun.c:5225: internal-error: switch_back_to_stepped_thread: Assertion `!schedlock_applies (1)' failed.^M
A problem internal to GDB has been detected,^M
further debugging may prove unreliable.^M
Quit this debugging session? (y or n) FAIL: gdb.threads/thread-execl.exp: schedlock step: get to main in new image (GDB internal error)
The assertion is correct. The issue is that GDB is mistakenly trying
to switch back to an exited thread, that was previously stepping when
it exited. This is exactly the sort of thing the test wants to make
sure doesn't happen:
# Now set a breakpoint at `main', and step over the execl call. The
# breakpoint at main should be reached. GDB should not try to revert
# back to the old thread from the old image and resume stepping it
We don't see this bug with schedlock off only because a different
sequence of events makes GDB manage to delete the thread instead of
marking it exited.
This particular internal error can be fixed by making the loop over
all threads in switch_back_to_stepped_thread skip exited threads.
But, looking over other ALL_THREADS users, all either can or should be
skipping exited threads too. So for simplicity, this patch replaces
ALL_THREADS with a new macro that skips exited threads itself, and
updates everything to use it.
Tested on x86_64 Fedora 20.
gdb/
2014-06-19 Pedro Alves <palves@redhat.com>
* gdbthread.h (ALL_THREADS): Delete.
(ALL_NON_EXITED_THREADS): New macro.
* btrace.c (btrace_free_objfile): Use ALL_NON_EXITED_THREADS
instead of ALL_THREADS.
* infrun.c (find_thread_needs_step_over)
(switch_back_to_stepped_thread): Use ALL_NON_EXITED_THREADS
instead of ALL_THREADS.
* record-btrace.c (record_btrace_open)
(record_btrace_stop_recording, record_btrace_close)
(record_btrace_is_replaying, record_btrace_resume)
(record_btrace_find_thread_to_move, record_btrace_wait): Likewise.
* remote.c (append_pending_thread_resumptions): Likewise.
* thread.c (thread_apply_all_command): Likewise.
gdb/testsuite/
2014-06-19 Pedro Alves <palves@redhat.com>
* gdb.threads/thread-execl.exp (do_test): New procedure, factored
out from ...
(top level): ... here. Iterate running tests under different
scheduler-locking settings.
Using the test program gdb.base/foll-fork.c, with follow-fork-mode set to
"child" and detach-on-fork set to "off", stepping or running past the fork
call results in the child process running to completion, when it should
just finish the single step. In addition, the breakpoint is not removed
from the parent process, so if it is resumed it receives a SIGTRAP.
Cause:
No matter what the setting for detach-on-fork, when stepping past a fork,
the single-step breakpoint (step_resume_breakpoint) is not handled
correctly in the parent. The SR breakpoint is cloned for the child
process, but before the clone is associated with the child it is treated as
a duplicate of the original, associated wth the parent. This results in
the insertion state of the original SR breakpoint and the clone being
"swapped" by breakpoint.c:update_global_location_list, so that the clone is
marked as inserted.
In the case where the parent is not detached, the two breakpoints remain in
that state. The breakpoint is never inserted in the child, because
although the cloned SR breakpoint is associated with the child, it is
marked as inserted. When the child is resumed, it runs to completion. The
breakpoint is never removed from the parent, so that if it is resumed after
the child exits, it gets a SIGTRAP.
Here is the sequence of events:
1) handle_inferior_event: FORK event is recognized.
2) handle_inferior_event: detach_breakpoints removes all breakpoints
from the child.
3) follow_fork: the parent SR breakpoint is cloned. Part of this procedure
is to call update_global_location_list, which swaps the insertion state of
the original and cloned SR breakpoints as part of ensuring that duplicate
breakpoints are only inserted once. At this point the original SR
breakpoint is not marked as inserted, and the clone is. The breakpoint is
actually inserted in the parent but not the child.
4) follow_fork: the original breakpoint is deleted by calling
delete_step_resume_breakpoint. Since the original is not marked as
inserted, the actual breakpoint remains in the parent process.
update_global_location_list is called again as part of the deletion. The
clone is still associated with the parent, but since it is marked as
enabled and inserted, the breakpoint is left in the parent.
5) follow_fork: if detach-on-fork is 'on', the actual breakpoint will be
removed from the parent in target_detach, based on the cloned breakpoint
still associated with the parent. Then the clone is no longer marked as
inserted. In follow_inferior_reset_breakpoints the clone is associated
with the child, and can be inserted.
If detach-on-fork is 'off', the actual breakpoint in the parent is never
removed (although the breakpoint had been deleted from the list). Since
the clone continues to be marked 'inserted', the SR breakpoint is never
inserted in the child.
Fix:
Set the cloned breakpoint as disabled from the moment it is created. This
is done by modifying clone_momentary_breakpoint to take an additional
argument, LOC_ENABLED, which is used as the value of the
bp_location->enabled member. The clone must be disabled at that point
because clone_momentary_breakpoint calls update_global_location_list, which
will swap treat the clone as a duplicate of the original breakpoint if it
is enabled.
All the calls to clone_momentary_breakpoint had to be modified to pass '1'
or '0'. I looked at implementing an enum for the enabled member, but
concluded that readability would suffer because there are so many places it
is used as a boolean, e.g. "if (bl->enabled)".
In follow_inferior_reset_breakpoints the clone is set to enabled once it
has been associated with the child process. With this, the bp_location
'inserted' member is maintained correctly throughout the follow-fork
procedure and the behavior is as expected.
The same treatment is given to the exception_resume_breakpoint when
following a fork.
Testing:
Ran 'make check' on Linux x64.
Along with the fix above, the coverage of the follow-fork test
gdb.base/foll-fork.exp was expanded to:
1) cover all the combinations of values for
follow-fork-mode and detach-on-fork
2) make sure that both user breakpoints and
single-step breakpoints are propagated
correctly to the child
3) check that the inferior list has the
expected contents after following the fork.
4) check that unfollowed, undetached inferiors
can be resumed.
gdb/
2014-06-18 Don Breazeal <donb@codesourcery.com>
* breakpoint.c (set_longjmp_breakpoint): Call
momentary_breakpoint_from_master with additional argument.
(set_longjmp_breakpoint_for_call_dummy): Call
momentary_breakpoint_from_master with additional argument.
(set_std_terminate_breakpoint): Call
momentary_breakpoint_from_master with additional argument.
(momentary_breakpoint_from_master): Add argument to function
definition and use it to initialize structure member flag.
(clone_momentary_breakpoint): Call
momentary_breakpoint_from_master with additional argument.
* infrun.c (follow_inferior_reset_breakpoints): Clear structure
member flags set in momentary_breakpoint_from_master.
gdb/testsuite/
2014-06-18 Don Breazeal <donb@codesourcery.com>
* gdb.base/foll-fork.exp (default_fork_parent_follow):
Deleted procedure.
(explicit_fork_parent_follow): Deleted procedure.
(explicit_fork_child_follow): Deleted procedure.
(test_follow_fork): New procedure.
(do_fork_tests): Replace calls to deleted procedures with
calls to test_follow_fork and reset GDB for subsequent
procedure calls.
branch showed some extra assertions I have in place triggering. Turns
out my previous change to 'resume' was incomplete, and we mishandle
the 'hw_step' / 'step' variable pair. (I swear I had fixed this, but
I guess I lost that in some local branch...)
Tested on x86_64 Fedora 20.
gdb/
2014-05-29 Pedro Alves <palves@redhat.com>
* infrun.c (resume): Rename local 'hw_step' to 'entry_step'
and make it const. When a single-step decays to a continue,
clear 'step', not 'hw_step'. Pass whether the caller wanted
to step to user_visible_resume_ptid, not what we ask the
target to do.
- all end_stepping_range callers also set stop_step.
- all places that set stop_step call end_stepping_range and
stop_waiting too.
IOW, all places where we handle "end stepping range" do:
ecs->event_thread->control.stop_step = 1;
end_stepping_range ();
stop_waiting (ecs);
Factor that out into end_stepping_range itself.
Tested on x86_64 Fedora 20.
gdb/
2014-05-29 Pedro Alves <palves@redhat.com>
* infrun.c (process_event_stop_test, handle_step_into_function)
(handle_step_into_function_backward): Adjust.
Don't set the even thread's stop_step and call stop_waiting before
calling end_stepping_range. Instead do that ...
(end_stepping_range): ... here. Take an ecs pointer parameter.
stop_stepping is called even when we weren't stepping. It's job really is:
static void
stop_waiting (struct execution_control_state *ecs)
{
...
/* Let callers know we don't want to wait for the inferior anymore. */
ecs->wait_some_more = 0;
}
So rename it for clarity.
gdb/
2014-05-29 Pedro Alves <palves@redhat.com>
* infrun.c (stop_stepping): Rename to ...
(stop_waiting): ... this.
(proceed): Update comment.
(process_event_stop_test, handle_inferior_event)
(handle_signal_stop, handle_step_into_function)
(handle_step_into_function_backward): Update.
This finally makes background execution commands possible by default.
However, in order to do that, there's one last thing we need to do --
we need to separate the MI and target notions of "async". Unlike the
CLI, where the user explicitly requests foreground vs background
execution in the execution command itself (c vs c&), MI chose to treat
"set target-async" specially -- setting it changes the default
behavior of execution commands.
So, we can't simply "set target-async" default to on, as that would
affect MI frontends. Instead we have to make the setting MI-specific,
and teach MI about sync commands on top of an async target.
Because the "target" word in "set target-async" ends up as a potential
source of confusion, the patch adds a "set mi-async" option, and makes
"set target-async" a deprecated alias.
Rather than make the targets always async, this patch introduces a new
"maint set target-async" option so that the GDB developer can control
whether the target is async. This makes it simpler to debug issues
arising only in the synchronous mode; important because sync mode
seems unlikely to go away.
Unlike in previous revisions, "set target-async" does not affect this
new maint parameter. The rationale for this is that then one can
easily run the test suite in the "maint set target-async off" mode and
have tests that enable mi-async fail just like they fail on
non-async-capable targets. This emulation is exactly the point of the
maint option.
I had asked Tom in a previous iteration to split the actual change of
the target async default to a separate patch, but it turns out that
that is quite awkward in this version of the patch, because with MI
async and target async decoupled (unlike in previous versions), if we
don't flip the default at the same time, then just "set target-async
on" alone never actually manages to do anything. It's best to not
have that transitory state in the tree.
Given "set target-async on" now only has effect for MI, the patch goes
through the testsuite removing it from non-MI tests. MI tests are
adjusted to use the new and less confusing "mi-async" spelling.
2014-05-29 Pedro Alves <palves@redhat.com>
Tom Tromey <tromey@redhat.com>
* NEWS: Mention "maint set target-async", "set mi-async", and that
background execution commands are now always available.
* target.h (target_async_permitted): Update comment.
* target.c (target_async_permitted, target_async_permitted_1):
Default to 1.
(set_target_async_command): Rename to ...
(maint_set_target_async_command): ... this.
(show_target_async_command): Rename to ...
(maint_show_target_async_command): ... this.
(_initialize_target): Adjust.
* infcmd.c (prepare_execution_command): Make extern.
* inferior.h (prepare_execution_command): Declare.
* infrun.c (set_observer_mode): Leave target async alone.
* mi/mi-interp.c (mi_interpreter_init): Install
mi_on_sync_execution_done as sync_execution_done observer.
(mi_on_sync_execution_done): New function.
(mi_execute_command_input_handler): Don't print the prompt if we
just started a synchronous command with an async target.
(mi_on_resume): Check sync_execution before printing prompt.
* mi/mi-main.h (mi_async_p): Declare.
* mi/mi-main.c: Include gdbcmd.h.
(mi_async_p): New function.
(mi_async, mi_async_1): New globals.
(set_mi_async_command, show_mi_async_command, mi_async): New
functions.
(exec_continue): Call prepare_execution_command.
(run_one_inferior, mi_cmd_exec_run, mi_cmd_list_target_features)
(mi_execute_async_cli_command): Use mi_async_p.
(_initialize_mi_main): Install "set mi-async". Make
"target-async" a deprecated alias.
2014-05-29 Pedro Alves <palves@redhat.com>
Tom Tromey <tromey@redhat.com>
* gdb.texinfo (Non-Stop Mode): Remove "set target-async 1"
from example.
(Asynchronous and non-stop modes): Document '-gdb-set mi-async'.
Mention that target-async is now deprecated.
(Maintenance Commands): Document maint set/show target-async.
2014-05-29 Pedro Alves <palves@redhat.com>
Tom Tromey <tromey@redhat.com>
* gdb.base/async-shell.exp: Don't enable target-async.
* gdb.base/async.exp
* gdb.base/corefile.exp (corefile_test_attach): Remove 'async'
parameter. Adjust.
(top level): Don't test with "target-async".
* gdb.base/dprintf-non-stop.exp: Don't enable target-async.
* gdb.base/gdb-sigterm.exp: Don't test with "target-async".
* gdb.base/inferior-died.exp: Don't enable target-async.
* gdb.base/interrupt-noterm.exp: Likewise.
* gdb.mi/mi-async.exp: Use "mi-async" instead of "target-async".
* gdb.mi/mi-nonstop-exit.exp: Likewise.
* gdb.mi/mi-nonstop.exp: Likewise.
* gdb.mi/mi-ns-stale-regcache.exp: Likewise.
* gdb.mi/mi-nsintrall.exp: Likewise.
* gdb.mi/mi-nsmoribund.exp: Likewise.
* gdb.mi/mi-nsthrexec.exp: Likewise.
* gdb.mi/mi-watch-nonstop.exp: Likewise.
* gdb.multi/watchpoint-multi.exp: Adjust comment.
* gdb.python/py-evsignal.exp: Don't enable target-async.
* gdb.python/py-evthreads.exp: Likewise.
* gdb.python/py-prompt.exp: Likewise.
* gdb.reverse/break-precsave.exp: Don't test with "target-async".
* gdb.server/solib-list.exp: Don't enable target-async.
* gdb.threads/thread-specific-bp.exp: Likewise.
* lib/mi-support.exp: Adjust to use mi-async.
Enabling target-async by default will require implementing sync
execution on top of an async target, much like foreground command are
implemented on the CLI in async mode.
In order to do that, we will need better control of when to print the
MI prompt. Currently the interp->display_prompt_p hook is all we
have, and MI just always returns false, meaning, make
display_gdb_prompt a no-op. We'll need to be able to know to print
the MI prompt in some of the conditions that display_gdb_prompt is
called from the core, but not all.
This is all a litte twisted currently. As we can see,
display_gdb_prompt is really CLI specific, so make the console
interpreters (console/tui) themselves call it. To be able to do that,
and add a few different observers that the interpreters can use to
distinguish when or why the the prompt is being printed:
#1 - one called whenever a command is cancelled due to an error.
#2 - another for when a foreground command just finished.
In both cases, CLI wants to print the prompt, while MI doesn't.
MI will want to print the prompt in the second case when in a special
MI mode.
The display_gdb_prompt call in interp_set made me pause. The comment
there reads:
/* Finally, put up the new prompt to show that we are indeed here.
Also, display_gdb_prompt for the console does some readline magic
which is needed for the console interpreter, at least... */
But, that looks very much like a no-op to me currently:
- the MI interpreter always return false in the prompt hook, meaning
actually display no prompt.
- the interpreter used at that point is still quiet. And the
console/tui interpreters return false in the prompt hook if they're
quiet, meaning actually display no prompt.
The only remaining possible use would then be the readline magic. But
whatever that might have been, it's not reacheable today either,
because display_gdb_prompt returns early, before touching readline if
the interpreter returns false in the display_prompt_p hook.
Tested on x86_64 Fedora 20, sync and async modes.
gdb/
2014-05-29 Pedro Alves <palves@redhat.com>
* cli/cli-interp.c (cli_interpreter_display_prompt_p): Delete.
(_initialize_cli_interp): Adjust.
* event-loop.c: Include "observer.h".
(start_event_loop): Notify 'command_error' observers instead of
calling display_gdb_prompt. Remove FIXME comment.
* event-top.c (display_gdb_prompt): Remove call into the
interpreters.
* inf-loop.c: Include "observer.h".
(inferior_event_handler): Notify 'command_error' observers instead
of calling display_gdb_prompt.
* infrun.c (fetch_inferior_event): Notify 'sync_execution_done'
observers instead of calling display_gdb_prompt.
* interps.c (interp_set): Don't call display_gdb_prompt.
(current_interp_display_prompt_p): Delete.
* interps.h (interp_prompt_p): Delete declaration.
(interp_prompt_p_ftype): Delete.
(struct interp_procs) <prompt_proc_p>: Delete field.
(current_interp_display_prompt_p): Delete declaration.
* mi-interp.c (mi_interpreter_prompt_p): Delete.
(_initialize_mi_interp): Adjust.
* tui-interp.c (tui_init): Install 'sync_execution_done' and
'command_error' observers.
(tui_on_sync_execution_done, tui_on_command_error): New
functions.
(tui_display_prompt_p): Delete.
(_initialize_tui_interp): Adjust.
gdb/doc/
2014-05-29 Pedro Alves <palves@redhat.com>
* observer.texi (sync_execution_done, command_error): New
subjects.
Ignoring expected and desired differences like whether the prompt is
output after *stoppped records, GDB MI output is still different in
sync and async modes.
In sync mode, when a CLI execution command is entered, the "reason"
field is missing in the *stopped async record. And in async mode, for
some events, like program exits, the corresponding CLI output is
missing in the CLI channel.
Vis, diff between sync vs async modes:
run
^running
*running,thread-id="1"
(gdb)
...
- ~"[Inferior 1 (process 15882) exited normally]\n"
=thread-exited,id="1",group-id="i1"
=thread-group-exited,id="i1",exit-code="0"
- *stopped
+ *stopped,reason="exited-normally"
si
...
(gdb)
~"0x000000000045e033\t29\t memset (&args, 0, sizeof args);\n"
- *stopped,frame=...,thread-id="1",stopped-threads="all",core="0"
+ *stopped,reason="end-stepping-range",frame=...,thread-id="1",stopped-threads="all",core="0"
(gdb)
In addition, in both cases, when a MI execution command is entered,
and a breakpoint triggers, the event is sent to the console too. But
some events like program exits have the CLI output missing in the CLI
channel:
-exec-run
^running
*running,thread-id="1"
(gdb)
...
=thread-exited,id="1",group-id="i1"
=thread-group-exited,id="i1",exit-code="0"
- *stopped
+ *stopped,reason="exited-normally"
We'll want to make background commands always possible by default.
IOW, make target-async be the default. But, in order to do that,
we'll need to emulate MI sync on top of an async target. That means
we'll have yet another combination to care for in the testsuite.
Rather than making the testsuite cope with all these differences, I
thought it better to just fix GDB to always have the complete output,
no matter whether it's in sync or async mode.
This is all related to interpreter-exec, and the corresponding uiout
switching. (Typing a CLI command directly in MI is shorthand for
running it through -interpreter-exec console.)
In sync mode, when a CLI command is active, normal_stop is called when
the current interpreter and uiout are CLI's. So print_XXX_reason
prints the stop reason to CLI uiout (only), and we don't show it in
MI.
In async mode the stop event is processed when we're back in the MI
interpreter, so the stop reason is printed directly to the MI uiout.
Fix this by making run control event printing roughly independent of
whatever is the current interpreter or uiout. That is, move these
prints to interpreter observers, that know whether to print or be
quiet, and if printing, which uiout to print to. In the case of the
console/tui interpreters, only print if the top interpreter. For MI,
always print.
Breakpoint hits / normal stops are already handled similarly -- MI has
a normal_stop observer that prints the event to both MI and the CLI,
though that could be cleaned up further in the direction of this
patch.
This also makes all of:
(gdb) foo
and
(gdb) interpreter-exec MI "-exec-foo"
and
(gdb)
-exec-foo
and
(gdb)
-interpreter-exec console "foo"
print as expected.
Tested on x86_64 Fedora 20, sync and async modes.
gdb/
2014-05-29 Pedro Alves <palves@redhat.com>
PR gdb/13860
* cli/cli-interp.c: Include infrun.h and observer.h.
(cli_uiout, cli_interp): New globals.
(cli_on_signal_received, cli_on_end_stepping_range)
(cli_on_signal_exited, cli_on_exited, cli_on_no_history): New
functions.
(cli_interpreter_init): Install them as 'end_stepping_range',
'signal_received' 'signal_exited', 'exited' and 'no_history'
observers.
(_initialize_cli_interp): Remove cli_interp local.
* infrun.c (handle_inferior_event): Call the several stop reason
observers instead of printing the stop reason directly.
(end_stepping_range): New function.
(print_end_stepping_range_reason, print_signal_exited_reason)
(print_exited_reason, print_signal_received_reason)
(print_no_history_reason): Make static, and add an uiout
parameter. Print to that instead of to CURRENT_UIOUT.
* infrun.h (print_end_stepping_range_reason)
(print_signal_exited_reason, print_exited_reason)
(print_signal_received_reason print_no_history_reason): New
declarations.
* mi/mi-common.h (struct mi_interp): Rename 'uiout' field to
'mi_uiout'.
<cli_uiout>: New field.
* mi/mi-interp.c (mi_interpreter_init): Adjust. Create the new
uiout for CLI output. Install 'signal_received',
'end_stepping_range', 'signal_exited', 'exited' and 'no_history'
observers.
(find_mi_interpreter, mi_interp_data, mi_on_signal_received)
(mi_on_end_stepping_range, mi_on_signal_exited, mi_on_exited)
(mi_on_no_history): New functions.
(ui_out_free_cleanup): Delete function.
(mi_on_normal_stop): Don't allocate a new uiout for CLI output,
instead use the one already stored in the MI interpreter data.
(mi_ui_out): Adjust.
* tui/tui-interp.c: Include infrun.h and observer.h.
(tui_interp): New global.
(tui_on_signal_received, tui_on_end_stepping_range)
(tui_on_signal_exited, tui_on_exited)
(tui_on_no_history): New functions.
(tui_init): Install them as 'end_stepping_range',
'signal_received' 'signal_exited', 'exited' and 'no_history'
observers.
(_initialize_tui_interp): Delete tui_interp local.
gdb/doc/
2014-05-29 Pedro Alves <palves@redhat.com>
PR gdb/13860
* observer.texi (signal_received, end_stepping_range)
(signal_exited, exited, no_history): New observer subjects.
gdb/testsuite/
2014-05-29 Pedro Alves <palves@redhat.com>
PR gdb/13860
* gdb.mi/mi-cli.exp: Always expect "end-stepping-range" stop
reason, even in sync mode.
If one sets a breakpoint with a condition that involves calling a
function in the inferior, and then the condition evaluates false, GDB
outputs one *running event for each time the program hits the
breakpoint. E.g.,
$ gdb return-false -i=mi
(gdb)
start
...
(gdb)
b 14 if return_false ()
&"b 14 if return_false ()\n"
~"Breakpoint 2 at 0x4004eb: file return-false.c, line 14.\n"
...
^done
(gdb)
c
&"c\n"
~"Continuing.\n"
^running
*running,thread-id=(...)
(gdb)
*running,thread-id=(...)
*running,thread-id=(...)
*running,thread-id=(...)
*running,thread-id=(...)
*running,thread-id=(...)
... repeat forever ...
An easy way a user can trip on this is with a dprintf with "set
dprintf-style call". In that case, a dprintf is just a breakpoint
that when hit GDB calls the printf function in the inferior, and then
resumes it, just like the case above.
If the breakpoint/dprintf is set in a loop, then these spurious events
can potentially slow down a frontend much, if it decides to refresh
its GUI whenever it sees this event (Eclipse is one such case).
When we run an infcall, we pretend we don't actually run the inferior.
This is already handled for the usual case of calling a function
directly from the CLI:
(gdb)
p return_false ()
&"p return_false ()\n"
~"$1 = 0"
~"\n"
^done
(gdb)
Note no *running, nor *stopped events. That's handled by:
static void
mi_on_resume (ptid_t ptid)
{
...
/* Suppress output while calling an inferior function. */
if (tp->control.in_infcall)
return;
and equivalent code on normal_stop.
However, in the cases of the PR, after finishing the infcall there's
one more resume, and mi_on_resume doesn't know that it should suppress
output then too, somehow.
The "running/stopped" state is a high level user/frontend state.
Internal stops are invisible to the frontend. If follows from that
that we should be setting the thread to running at a higher level
where we still know the set of threads the user _intends_ to resume.
Currently we mark a thread as running from within target_resume, a low
level target operation. As consequence, today, if we resume a
multi-threaded program while stopped at a breakpoint, we see this:
-exec-continue
^running
*running,thread-id="1"
(gdb)
*running,thread-id="all"
The first *running was GDB stepping over the breakpoint, and the
second is GDB finally resuming everything.
Between those two *running's, threads other than "1" still have their
state set to stopped. That's bogus -- in async mode, this opens a
tiny window between both resumes where the user might try to run
another execution command to threads other than thread 1, and very
much confuse GDB.
That is, the "step" below should fail the "step", complaining that the
thread is running:
(gdb) c -a &
(gdb) thread 2
(gdb) step
IOW, threads that GDB happens to not resume immediately (say, because
it needs to step over a breakpoint) shall still be marked as running.
Then, if we move marking threads as running to a higher layer,
decoupled from target_resume, plus skip marking threads as running
when running an infcall, the spurious *running events disappear,
because there will be no state transitions at all.
I think we might end up adding a new thread state -- THREAD_INFCALL or
some such, however since infcalls are always synchronous today, I
didn't find a need. There's no way to execute a CLI/MI command
directly from the prompt if some thread is running an infcall.
Tested on x86_64 Fedora 20.
gdb/
2014-05-29 Pedro Alves <palves@redhat.com>
PR PR15693
* infrun.c (resume): Determine how much to resume depending on
whether the caller wanted a step, not whether we can hardware step
the target. Mark all threads that we intend to run as running,
unless we're calling an inferior function.
(normal_stop): If the thread is running an infcall, don't finish
thread state.
* target.c (target_resume): Don't mark threads as running here.
gdb/testsuite/
2014-05-29 Pedro Alves <palves@redhat.com>
Hui Zhu <hui@codesourcery.com>
PR PR15693
* gdb.mi/mi-condbreak-call-thr-state-mt.c: New file.
* gdb.mi/mi-condbreak-call-thr-state-st.c: New file.
* gdb.mi/mi-condbreak-call-thr-state.c: New file.
* gdb.mi/mi-condbreak-call-thr-state.exp: New file.
Move infrun.c declarations out of inferior.h to a new infrun.h file.
Tested by building on:
i686-w64-mingw32, enable-targets=all
x86_64-linux, enable-targets=all
i586-pc-msdosdjgpp
And also grepped the whole tree for each symbol moved to find where
infrun.h might be necessary.
gdb/
2014-05-22 Pedro Alves <palves@redhat.com>
* inferior.h (debug_infrun, debug_displaced, stop_on_solib_events)
(sync_execution, sched_multi, step_stop_if_no_debug, non_stop)
(disable_randomization, enum exec_direction_kind)
(execution_direction, stop_registers, start_remote)
(clear_proceed_status, proceed, resume, user_visible_resume_ptid)
(wait_for_inferior, normal_stop, get_last_target_status)
(prepare_for_detach, fetch_inferior_event, init_wait_for_inferior)
(insert_step_resume_breakpoint_at_sal)
(follow_inferior_reset_breakpoints, stepping_past_instruction_at)
(set_step_info, print_stop_event, signal_stop_state)
(signal_print_state, signal_pass_state, signal_stop_update)
(signal_print_update, signal_pass_update)
(update_signals_program_target, clear_exit_convenience_vars)
(displaced_step_dump_bytes, update_observer_mode)
(signal_catch_update, gdb_signal_from_command): Move
declarations ...
* infrun.h: ... to this new file.
* amd64-tdep.c: Include infrun.h.
* annotate.c: Include infrun.h.
* arch-utils.c: Include infrun.h.
* arm-linux-tdep.c: Include infrun.h.
* arm-tdep.c: Include infrun.h.
* break-catch-sig.c: Include infrun.h.
* breakpoint.c: Include infrun.h.
* common/agent.c: Include infrun.h instead of inferior.h.
* corelow.c: Include infrun.h.
* event-top.c: Include infrun.h.
* go32-nat.c: Include infrun.h.
* i386-tdep.c: Include infrun.h.
* inf-loop.c: Include infrun.h.
* infcall.c: Include infrun.h.
* infcmd.c: Include infrun.h.
* infrun.c: Include infrun.h.
* linux-fork.c: Include infrun.h.
* linux-nat.c: Include infrun.h.
* linux-thread-db.c: Include infrun.h.
* monitor.c: Include infrun.h.
* nto-tdep.c: Include infrun.h.
* procfs.c: Include infrun.h.
* record-btrace.c: Include infrun.h.
* record-full.c: Include infrun.h.
* remote-m32r-sdi.c: Include infrun.h.
* remote-mips.c: Include infrun.h.
* remote-notif.c: Include infrun.h.
* remote-sim.c: Include infrun.h.
* remote.c: Include infrun.h.
* reverse.c: Include infrun.h.
* rs6000-tdep.c: Include infrun.h.
* s390-linux-tdep.c: Include infrun.h.
* solib-irix.c: Include infrun.h.
* solib-osf.c: Include infrun.h.
* solib-svr4.c: Include infrun.h.
* target.c: Include infrun.h.
* top.c: Include infrun.h.
* windows-nat.c: Include infrun.h.
* mi/mi-interp.c: Include infrun.h.
* mi/mi-main.c: Include infrun.h.
* python/py-threadevent.c: Include infrun.h.
A small cleanup - so we can call the print routine without affecting
--return-child-result.
gdb/
2014-05-22 Pedro Alves <palves@redhat.com>
* infrun.c (handle_inferior_event): Store the exit code for
--return-child-result here, instead of ...
(print_exited_reason): ... here.
The other part of PR gdb/13860 is about console execution commands in
MI getting their output half lost. E.g., take the finish command,
executed on a frontend's GDB console:
sync:
finish
&"finish\n"
~"Run till exit from #0 usleep (useconds=10) at ../sysdeps/unix/sysv/linux/usleep.c:27\n"
^running
*running,thread-id="1"
(gdb)
~"0x00000000004004d7 in foo () at stepinf.c:6\n"
~"6\t usleep (10);\n"
~"Value returned is $1 = 0\n"
*stopped,reason="function-finished",frame={addr="0x00000000004004d7",func="foo",args=[],file="stepinf.c",fullname="/home/pedro/gdb/tests/stepinf.c",line="6"},thread-id="1",stopped-threads="all",core="1"
async:
finish
&"finish\n"
~"Run till exit from #0 usleep (useconds=10) at ../sysdeps/unix/sysv/linux/usleep.c:27\n"
^running
*running,thread-id="1"
(gdb)
*stopped,reason="function-finished",frame={addr="0x00000000004004d7",func="foo",args=[],file="stepinf.c",fullname="/home/pedro/gdb/tests/stepinf.c",line="6"},gdb-result-var="$1",return-value="0",thread-id="1",stopped-threads="all",core="0"
Note how all the "Value returned" etc. output is missing in async mode.
The same happens with e.g., catchpoints:
=breakpoint-modified,bkpt={number="1",type="catchpoint",disp="keep",enabled="y",what="22016",times="1"}
~"\nCatchpoint "
~"1 (forked process 22016), 0x0000003791cbd8a6 in __libc_fork () at ../nptl/sysdeps/unix/sysv/linux/fork.c:131\n"
~"131\t pid = ARCH_FORK ();\n"
*stopped,reason="fork",disp="keep",bkptno="1",newpid="22016",frame={addr="0x0000003791cbd8a6",func="__libc_fork",args=[],file="../nptl/sysdeps/unix/sysv/linux/fork.c",fullname="/usr/src/debug/glibc-2.14-394-g8f3b1ff/nptl/sysdeps/unix/sysv/linux/fork.c",line="131"},thread-id="1",stopped-threads="all",core="0"
where all those ~ lines are missing in async mode, or just the "step"
current line indication:
s
&"s\n"
^running
*running,thread-id="all"
(gdb)
~"13\t foo ();\n"
*stopped,frame={addr="0x00000000004004ef",func="main",args=[{name="argc",value="1"},{name="argv",value="0x7fffffffdd78"}],file="stepinf.c",fullname="/home/pedro/gdb/tests/stepinf.c",line="13"},thread-id="1",stopped-threads="all",core="3"
(gdb)
Or in the case of the PRs example, the "Stopped due to shared library
event" note:
start
&"start\n"
~"Temporary breakpoint 1 at 0x400608: file ../../../src/gdb/testsuite/gdb.mi/solib-main.c, line 21.\n"
=breakpoint-created,bkpt={number="1",type="breakpoint",disp="del",enabled="y",addr="0x0000000000400608",func="main",file="../../../src/gdb/testsuite/gdb.mi/solib-main.c",fullname="/home/pedro/gdb/mygit/src/gdb/testsuite/gdb.mi/solib-main.c",line="21",times="0",original-location="main"}
~"Starting program: /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/solib-main \n"
=thread-group-started,id="i1",pid="21990"
=thread-created,id="1",group-id="i1"
^running
*running,thread-id="all"
(gdb)
=library-loaded,id="/lib64/ld-linux-x86-64.so.2",target-name="/lib64/ld-linux-x86-64.so.2",host-name="/lib64/ld-linux-x86-64.so.2",symbols-loaded="0",thread-group="i1"
~"Stopped due to shared library event (no libraries added or removed)\n"
*stopped,reason="solib-event",thread-id="1",stopped-threads="all",core="3"
(gdb)
IMO, if you're typing execution commands in a frontend's console, you
expect to see their output. Indeed it's what you get in sync mode. I
think async mode should do the same. Deciding what to mirror to the
console wrt to breakpoints and random stops gets messy real fast.
E.g., say "s" trips on a breakpoint. We'd clearly want to mirror the
event to the console in this case. But what about more complicated
cases like "s&; thread n; s&", and one of those steps spawning a new
thread, and that thread hitting a breakpoint? It's impossible in
general to track whether the thread had any relation to the commands
that had been executed. So I think we should just simplify and always
mirror breakpoints and random events to the console.
Notes:
- mi->out is the same as gdb_stdout when MI is the current
interpreter. I think that referring to that directly is cleaner.
An earlier revision of this patch made the changes that are now
done in mi_on_normal_stop directly in infrun.c:normal_stop, and so
not having an obvious place to put the new uiout by then, and not
wanting to abuse CLI's uiout, I made a temporary uiout when
necessary.
- Hopefuly the rest of the patch is more or less obvious given the
comments added.
Tested on x86_64 Fedora 20, no regressions.
2014-05-21 Pedro Alves <palves@redhat.com>
PR gdb/13860
* gdbthread.h (struct thread_control_state): New field
`command_interp'.
* infrun.c (follow_fork): Copy the new thread control field to the
child fork thread.
(clear_proceed_status_thread): Clear the new thread control field.
(proceed): Set the new thread control field.
* interps.h (command_interp): Declare.
* interps.c (command_interpreter): New global.
(command_interp): New function.
(interp_exec): Set `command_interpreter' while here.
* cli-out.c (cli_uiout_dtor): New function.
(cli_ui_out_impl): Install it.
* mi/mi-interp.c: Include cli-out.h.
(mi_cmd_interpreter_exec): Add comment.
(restore_current_uiout_cleanup): New function.
(ui_out_free_cleanup): New function.
(mi_on_normal_stop): If finishing an execution command started by
a CLI command, or any kind of breakpoint-like event triggered,
print the stop event to the output (CLI) stream.
* mi/mi-out.c (mi_ui_out_impl): Install NULL `dtor' handler.
2014-05-21 Pedro Alves <palves@redhat.com>
PR gdb/13860
* gdb.mi/mi-cli.exp (line_callee4_next_step): New global.
(top level): Test that output related to execution commands is
sent to the console with CLI commands, but not with MI commands.
Test that breakpoint events are always mirrored to the console.
Also expect the new source line to be output after a "next" in
async mode too. Make it a pass/fail test.
* gdb.mi/mi-solib.exp: Test that the CLI solib event note is
output.
* lib/mi-support.exp (mi_gdb_expect_cli_output): New procedure.
I noticed that "list" behaves differently in CLI vs MI. Particularly:
$ ./gdb -nx -q ./testsuite/gdb.mi/mi-cli
Reading symbols from /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/mi-cli...done.
(gdb) start
Temporary breakpoint 1 at 0x40054d: file ../../../src/gdb/testsuite/gdb.mi/basics.c, line 62.
Starting program: /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/mi-cli
Temporary breakpoint 1, main () at ../../../src/gdb/testsuite/gdb.mi/basics.c:62
62 callee1 (2, "A string argument.", 3.5);
(gdb) list
57 {
58 }
59
60 main ()
61 {
62 callee1 (2, "A string argument.", 3.5);
63 callee1 (2, "A string argument.", 3.5);
64
65 do_nothing (); /* Hello, World! */
66
(gdb)
Note the list started at line 57. IOW, the program stopped at line
62, and GDB centered the list on that.
compare with:
$ ./gdb -nx -q ./testsuite/gdb.mi/mi-cli -i=mi
=thread-group-added,id="i1"
~"Reading symbols from /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/mi-cli..."
~"done.\n"
(gdb)
start
&"start\n"
...
~"\nTemporary breakpoint "
~"1, main () at ../../../src/gdb/testsuite/gdb.mi/basics.c:62\n"
~"62\t callee1 (2, \"A string argument.\", 3.5);\n"
*stopped,reason="breakpoint-hit",disp="del",bkptno="1",frame={addr="0x000000000040054d",func="main",args=[],file="../../../src/gdb/testsuite/gdb.mi/basics.c",fullname="/home/pedro/gdb/mygit/src/gdb/testsuite/gdb.mi/basics.c",line="62"},thread-id="1",stopped-threads="all",core="0"
=breakpoint-deleted,id="1"
(gdb)
-interpreter-exec console list
~"62\t callee1 (2, \"A string argument.\", 3.5);\n"
~"63\t callee1 (2, \"A string argument.\", 3.5);\n"
~"64\t\n"
~"65\t do_nothing (); /* Hello, World! */\n"
~"66\t\n"
~"67\t callme (1);\n"
~"68\t callme (2);\n"
~"69\t\n"
~"70\t return 0;\n"
~"71\t}\n"
^done
(gdb)
Here the list starts at line 62, where the program was stopped.
This happens because print_stack_frame, called from both normal_stop
and mi_on_normal_stop, is the function responsible for setting the
current sal from the selected frame, overrides the PRINT_WHAT
argument, and only after that does it decide whether to center the
current sal line or not, based on the overridden value, and it will
always decide false.
(The print_stack_frame call in mi_on_normal_stop is a little different
from the call in normal_stop, in that it is an unconditional
SRC_AND_LOC call. A future patch will make those uniform.)
A previous version of this patch made MI uniform with CLI here, by
making print_stack_frame also center when MI is active. That changed
the output of a "list" command in mi-cli.exp, to expect line 57
instead of 62, as per the example above.
However, looking deeper, that list in question is the first "list"
after the program stops, and right after the stop, before the "list",
the test did "set listsize 1". Let's try the same thing with the CLI:
(gdb) start
62 callee1 (2, "A string argument.", 3.5);
(gdb) set listsize 1
(gdb) list
57 {
Huh, that's unexpected. Why the 57? It's because print_stack_frame,
called in reaction to the breakpoint stop, expecting the next "list"
to show 10 lines (the listsize at the time) around line 62, sets the
lines listed range to 57-67 (62 +/- 5). If the user changes the
listsize before "list", why would we still show that range? Looks
bogus to me.
So the fix for this whole issue should be delay trying to center the
listing to until actually listing, so that the correct listsize can be
taken into account. This makes MI and CLI uniform too, as it deletes
the center code from print_stack_frame.
A series of tests are added to list.exp to cover this. mi-cli.exp was
after all correct all along, but it now gains an additional test that
lists lines with listsize 10, to ensure the centering is consistent
with CLI's.
One related Python test changed related output -- it's a test that
prints the line number after stopping for a breakpoint, similar to the
new list.exp tests. Previously we'd print the stop line minus 5 (due
to the premature centering), now we print the stop line. I think
that's a good change.
Tested on x86_64 Fedora 20.
gdb/
2014-05-21 Pedro Alves <palves@redhat.com>
* cli/cli-cmds.c (list_command): Handle the first "list" after the
current source line having changed.
* frame.h (set_current_sal_from_frame): Remove 'center' parameter.
* infrun.c (normal_stop): Adjust call to
set_current_sal_from_frame.
* source.c (clear_lines_listed_range): New function.
(set_current_source_symtab_and_line, identify_source_line): Clear
the lines listed range.
(line_info): Handle the first "info line" after the current source
line having changed.
* stack.c (print_stack_frame): Remove center handling.
(set_current_sal_from_frame): Remove 'center' parameter. Don't
center sal.line.
gdb/testsuite/
2014-05-21 Pedro Alves <palves@redhat.com>
* gdb.base/list.exp (build_pattern, test_list): New procedures.
Use them to test variations of "list" after reaching a breakpoint.
* gdb.mi/mi-cli.exp (line_main_callme_2): New global.
Test "list" with listsize 10 after reaching a breakpoint.
* gdb.python/python.exp (decode_line current location line
number): Adjust expected line number.
should_resume is set to 1 at the beginning and never changed.
gdb/ChangeLog:
2014-05-13 Simon Marchi <simon.marchi@ericsson.com>
* infrun.c (resume): Remove should_resume (unused). Move up
declaration of resume_ptid.
If a thread trips on a breakpoint that needs stepping over just after
finishing a step over, GDB currently fails an assertion. This is a
regression caused by the "Handle multiple step-overs." patch
(99619beac6) at
https://sourceware.org/ml/gdb-patches/2014-02/msg00765.html.
(gdb) x /4i $pc
=> 0x400540 <main+4>: movl $0x0,0x2003da(%rip) # 0x600924 <i>
0x40054a <main+14>: movl $0x1,0x2003d0(%rip) # 0x600924 <i>
0x400554 <main+24>: movl $0x2,0x2003c6(%rip) # 0x600924 <i>
0x40055e <main+34>: movl $0x3,0x2003bc(%rip) # 0x600924 <i>
(gdb) PASS: gdb.base/consecutive-step-over.exp: get breakpoint addresses
break *0x40054a
Breakpoint 2 at 0x40054a: file ../../../src/gdb/testsuite/gdb.base/consecutive-step-over.c, line 23.
(gdb) PASS: gdb.base/consecutive-step-over.exp: insn 1: set breakpoint
condition $bpnum condition
(gdb) PASS: gdb.base/consecutive-step-over.exp: insn 1: set condition
break *0x400554
Breakpoint 3 at 0x400554: file ../../../src/gdb/testsuite/gdb.base/consecutive-step-over.c, line 24.
(gdb) PASS: gdb.base/consecutive-step-over.exp: insn 2: set breakpoint
condition $bpnum condition
(gdb) PASS: gdb.base/consecutive-step-over.exp: insn 2: set condition
break *0x40055e
Breakpoint 4 at 0x40055e: file ../../../src/gdb/testsuite/gdb.base/consecutive-step-over.c, line 25.
(gdb) PASS: gdb.base/consecutive-step-over.exp: insn 3: set breakpoint
condition $bpnum condition
(gdb) PASS: gdb.base/consecutive-step-over.exp: insn 3: set condition
break 27
Breakpoint 5 at 0x400568: file ../../../src/gdb/testsuite/gdb.base/consecutive-step-over.c, line 27.
(gdb) continue
Continuing.
../../src/gdb/infrun.c:5200: internal-error: switch_back_to_stepped_thread: Assertion `!tp->control.trap_expected' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
FAIL: gdb.base/consecutive-step-over.exp: continue to breakpoint: break here (GDB internal error)
The assertion fails, because the code is not expecting that the event
thread itself might need another step over. IOW, not expecting that
TP in:
tp = find_thread_needs_step_over (stepping_thread != NULL,
stepping_thread);
could be the event thread.
A small fix for this would be to clear the event thread's
trap_expected earlier, before asserting. But looking deeper, although
currently_stepping_or_nexting_callback's intention is finding the
thread that is doing a step/next, it also returns the thread that is
doing a step-over dance, with trap_expected set. If there ever was a
reason for that (it was I who added
currently_stepping_or_nexting_callback , but I can't recall why I put
trap_expected there in the first place), the only remaining reason
nowadays is to aid in implementing switch_back_to_stepped_thread's
assertion that is now triggering, by piggybacking on the walk over all
threads, thus avoiding a separate walk. This is quite obscure, and I
think we can do even better, by merging the walks that look for the
stepping thread, and the walk that looks for some thread that might
need a step over.
Tested on x86_64 Fedora 17, native and gdbserver, and also native on
top of my "software single-step on x86_64" series.
gdb/
2014-04-22 Pedro Alves <palves@redhat.com>
* infrun.c (schedlock_applies): New function, factored out from
find_thread_needs_step_over.
(find_thread_needs_step_over): Use it.
(switch_back_to_stepped_thread): Always clear trap_expected if the
step over is finished. Return early if scheduler locking applies.
Look for the stepping thread and a potential step-over thread with
a single loop.
(currently_stepping_or_nexting_callback): Delete.
2014-04-22 Pedro Alves <palves@redhat.com>
* gdb.base/consecutive-step-over.c: New file.
* gdb.base/consecutive-step-over.exp: New file.
This test fails with current mainline.
If the program stopped for a breakpoint in thread 1, and then the user
switches to thread 2, and resumes the program, GDB first switches back
to thread 1 to step it over the breakpoint, in order to make progress.
However, that logic only considers the last reported event, assuming
only one thread needs that stepping over dance.
That's actually not true when we play with scheduler-locking. The
patch adds an example to the testsuite of multiple threads needing a
step-over before the stepping thread can be resumed. With current
mainline, the program re-traps the same breakpoint it had already
trapped before.
E.g.:
Breakpoint 2, main () at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:99
99 wait_threads (); /* set wait-threads breakpoint here */
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: continue to breakpoint: run to breakpoint
info threads
Id Target Id Frame
3 Thread 0x7ffff77c9700 (LWP 4310) "multiple-step-o" 0x00000000004007ca in child_function_3 (arg=0x1) at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:43
2 Thread 0x7ffff7fca700 (LWP 4309) "multiple-step-o" 0x0000000000400827 in child_function_2 (arg=0x0) at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:60
* 1 Thread 0x7ffff7fcb740 (LWP 4305) "multiple-step-o" main () at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:99
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: info threads shows all threads
set scheduler-locking on
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: set scheduler-locking on
break 44
Breakpoint 3 at 0x4007d3: file ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c, line 44.
(gdb) break 61
Breakpoint 4 at 0x40082d: file ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c, line 61.
(gdb) thread 3
[Switching to thread 3 (Thread 0x7ffff77c9700 (LWP 4310))]
#0 0x00000000004007ca in child_function_3 (arg=0x1) at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:43
43 (*myp) ++;
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: thread 3
continue
Continuing.
Breakpoint 3, child_function_3 (arg=0x1) at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:44
44 callme (); /* set breakpoint thread 3 here */
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: continue to breakpoint: run to breakpoint in thread 3
p *myp = 0
$1 = 0
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: unbreak loop in thread 3
thread 2
[Switching to thread 2 (Thread 0x7ffff7fca700 (LWP 4309))]
#0 0x0000000000400827 in child_function_2 (arg=0x0) at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:60
60 (*myp) ++;
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: thread 2
continue
Continuing.
Breakpoint 4, child_function_2 (arg=0x0) at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:61
61 callme (); /* set breakpoint thread 2 here */
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: continue to breakpoint: run to breakpoint in thread 2
p *myp = 0
$2 = 0
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: unbreak loop in thread 2
thread 1
[Switching to thread 1 (Thread 0x7ffff7fcb740 (LWP 4305))]
#0 main () at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:99
99 wait_threads (); /* set wait-threads breakpoint here */
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: thread 1
set scheduler-locking off
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: set scheduler-locking off
At this point all thread are stopped for a breakpoint that needs stepping over.
(gdb) step
Breakpoint 2, main () at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:99
99 wait_threads (); /* set wait-threads breakpoint here */
(gdb) FAIL: gdb.threads/multiple-step-overs.exp: step
But that "step" retriggers the same breakpoint instead of making
progress.
The patch teaches GDB to step over all breakpoints of all threads
before resuming the stepping thread.
Tested on x86_64 Fedora 17, against pristine mainline, and also my
branch that implements software single-stepping on x86.
gdb/
2014-03-20 Pedro Alves <palves@redhat.com>
* infrun.c (prepare_to_proceed): Delete.
(thread_still_needs_step_over): New function.
(find_thread_needs_step_over): New function.
(proceed): If the current thread needs a step-over, set its
steping_over_breakpoint flag. Adjust to use
find_thread_needs_step_over instead of prepare_to_proceed.
(process_event_stop_test): For BPSTAT_WHAT_STOP_NOISY and
BPSTAT_WHAT_STOP_SILENT, assume the thread stopped for a
breakpoint.
(switch_back_to_stepped_thread): Step over breakpoints of all
threads not the stepping thread, before switching back to the
stepping thread.
gdb/testsuite/
2014-03-20 Pedro Alves <palves@redhat.com>
* gdb.threads/multiple-step-overs.c: New file.
* gdb.threads/multiple-step-overs.exp: New file.
* gdb.threads/signal-while-stepping-over-bp-other-thread.exp:
Adjust expected infrun debug output.
Even with deferred_step_ptid out of the way, GDB can still lose
watchpoints.
If a watchpoint triggers and the PC points to an address where a
thread-specific breakpoint for another thread is set, the thread-hop
code triggers, and we lose the watchpoint:
if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
{
int thread_hop_needed = 0;
struct address_space *aspace =
get_regcache_aspace (get_thread_regcache (ecs->ptid));
/* Check if a regular breakpoint has been hit before checking
for a potential single step breakpoint. Otherwise, GDB will
not see this breakpoint hit when stepping onto breakpoints. */
if (regular_breakpoint_inserted_here_p (aspace, stop_pc))
{
if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid))
thread_hop_needed = 1;
^^^^^^^^^^^^^^^^^^^^^
}
And on software single-step targets, even without a thread-specific
breakpoint in the way, here in the thread-hop code:
else if (singlestep_breakpoints_inserted_p)
{
...
if (!ptid_equal (singlestep_ptid, ecs->ptid)
&& in_thread_list (singlestep_ptid))
{
/* If the PC of the thread we were trying to single-step
has changed, discard this event (which we were going
to ignore anyway), and pretend we saw that thread
trap. This prevents us continuously moving the
single-step breakpoint forward, one instruction at a
time. If the PC has changed, then the thread we were
trying to single-step has trapped or been signalled,
but the event has not been reported to GDB yet.
There might be some cases where this loses signal
information, if a signal has arrived at exactly the
same time that the PC changed, but this is the best
we can do with the information available. Perhaps we
should arrange to report all events for all threads
when they stop, or to re-poll the remote looking for
this particular thread (i.e. temporarily enable
schedlock). */
CORE_ADDR new_singlestep_pc
= regcache_read_pc (get_thread_regcache (singlestep_ptid));
if (new_singlestep_pc != singlestep_pc)
{
enum gdb_signal stop_signal;
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread,"
" but expected thread advanced also\n");
/* The current context still belongs to
singlestep_ptid. Don't swap here, since that's
the context we want to use. Just fudge our
state and continue. */
stop_signal = ecs->event_thread->suspend.stop_signal;
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
ecs->ptid = singlestep_ptid;
ecs->event_thread = find_thread_ptid (ecs->ptid);
ecs->event_thread->suspend.stop_signal = stop_signal;
stop_pc = new_singlestep_pc;
}
else
{
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog,
"infrun: unexpected thread\n");
thread_hop_needed = 1;
stepping_past_singlestep_breakpoint = 1;
saved_singlestep_ptid = singlestep_ptid;
}
}
}
we either end up with thread_hop_needed, ignoring the watchpoint
SIGTRAP, or switch to the stepping thread, again ignoring that the
SIGTRAP could be for some other event.
The new test added by this patch exercises both paths.
So the fix is similar to the deferred_step_ptid fix -- defer the
thread hop to _after_ the SIGTRAP had a change of passing through the
regular bpstat handling. If the wrong thread hits a breakpoint, we'll
just end up with BPSTAT_WHAT_SINGLE, and if nothing causes a stop,
keep_going starts a step-over.
Most of the stepping_past_singlestep_breakpoint mechanism is really
not necessary -- setting the thread to step over a breakpoint with
thread->trap_expected is sufficient to keep all other threads locked.
It's best to still keep the flag in some form though, because when we
get to keep_going, the software single-step breakpoint we need to step
over is already gone -- an optimization done by a follow up patch will
check whether a step-over is still be necessary by looking to see
whether the breakpoint is still there, and would find the thread no
longer needs a step-over, while we still want it.
Special care is still needed to handle the case of PC of the thread we
were trying to single-step having changed, like in the old code. We
can't just keep_going and re-step it, as in that case we can over-step
the thread (if it was already done with the step, but hasn't reported
it yet, we'd ask it to step even further). That's now handled in
switch_back_to_stepped_thread. As bonus, we're now using a technique
that doesn't lose signals, unlike the old code -- we now insert a
breakpoint at PC, and resume, which either reports the breakpoint
immediately, or any pending signal.
Tested on x86_64 Fedora 17, against pristine mainline, and against a
branch that implements software single-step on x86.
gdb/
2014-03-20 Pedro Alves <palves@redhat.com>
* breakpoint.c (single_step_breakpoint_inserted_here_p): Make
extern.
* breakpoint.h (single_step_breakpoint_inserted_here_p): Declare.
* infrun.c (saved_singlestep_ptid)
(stepping_past_singlestep_breakpoint): Delete.
(resume): Remove stepping_past_singlestep_breakpoint handling.
(proceed): Store the prev_pc of the stepping thread too.
(init_wait_for_inferior): Adjust. Clear singlestep_ptid and
singlestep_pc.
(enum infwait_states): Delete infwait_thread_hop_state.
(struct execution_control_state) <hit_singlestep_breakpoint>: New
field.
(handle_inferior_event): Adjust.
(handle_signal_stop): Delete stepping_past_singlestep_breakpoint
handling and the thread-hop code. Before removing single-step
breakpoints, check whether the thread hit a single-step breakpoint
of another thread. If it did, the trap is not a random signal.
(switch_back_to_stepped_thread): If the event thread hit a
single-step breakpoint, unblock it before switching to the
stepping thread. Handle the case of the stepped thread having
advanced already.
(keep_going): Handle the case of the current thread moving past a
single-step breakpoint.
gdb/testsuite/
2014-03-20 Pedro Alves <palves@redhat.com>
* gdb.threads/step-over-trips-on-watchpoint.c: New file.
* gdb.threads/step-over-trips-on-watchpoint.exp: New file.
Say the program is stopped at a breakpoint, and the user sets a
watchpoint. When the program is next resumed, GDB will first step
over the breakpoint, as explained in the manual:
@value {GDBN} normally ignores breakpoints when it resumes
execution, until at least one instruction has been executed. If it
it did not do this, you would be unable to proceed past a breakpoint
without first disabling the breakpoint. This rule applies whether
or not the breakpoint already existed when your program stopped.
However, GDB currently also removes watchpoints, catchpoints, etc.,
and that means that the first instruction off the breakpoint does not
trigger the watchpoint, catchpoint, etc.
testsuite/gdb.base/watchpoint.exp has a kfail for this.
The PR proposes installing watchpoints only when stepping over a
breakpoint, but that misses catchpoints, etc.
A better fix would instead work from the opposite direction -- remove
only real breakpoints, leaving all other kinds of breakpoints
inserted.
But, going further, it's really a waste to constantly remove/insert
all breakpoints when stepping over a single breakpoint (generating a
pair of RSP z/Z packets for each breakpoint), so the fix goes a step
further and makes GDB remove _only_ the breakpoint being stepped over,
leaving all others installed. This then has the added benefit of
reducing breakpoint-related RSP traffic substancialy when there are
many breakpoints set.
gdb/
2014-03-20 Pedro Alves <palves@redhat.com>
PR breakpoints/7143
* breakpoint.c (should_be_inserted): Don't insert breakpoints that
are being stepped over.
(breakpoint_address_match): Make extern.
* breakpoint.h (breakpoint_address_match): New declaration.
* inferior.h (stepping_past_instruction_at): New declaration.
* infrun.c (struct step_over_info): New type.
(step_over_info): New global.
(set_step_over_info, clear_step_over_info)
(stepping_past_instruction_at): New functions.
(handle_inferior_event): Clear the step-over info when
trap_expected is cleared.
(resume): Remove now stale comment.
(clear_proceed_status): Clear step-over info.
(proceed): Adjust step-over handling to set or clear the step-over
info instead of removing all breakpoints.
(handle_signal_stop): When setting up a thread-hop, don't remove
breakpoints here.
(stop_stepping): Clear step-over info.
(keep_going): Adjust step-over handling to set or clear step-over
info and then always inserting breakpoints, instead of removing
all breakpoints when stepping over one.
gdb/testsuite/
2014-03-20 Pedro Alves <palves@redhat.com>
PR breakpoints/7143
* gdb.base/watchpoint.exp: Mention bugzilla bug number instead of
old gnats gdb/38. Remove kfail. Adjust to use gdb_test instead
of gdb_test_multiple.
* gdb.cp/annota2.exp: Remove kfail for gdb/38.
* gdb.cp/annota3.exp: Remove kfail for gdb/38.
Consider the case of the user doing "step" in thread 2, while thread 1
had previously stopped for a breakpoint. In order to make progress,
GDB makes thread 1 step over its breakpoint first (with all other
threads stopped), and once that is over, thread 2 then starts stepping
(with thread 1 and all others running free, by default). If GDB
didn't do that, thread 1 would just trip on the same breakpoint
immediately again. This is what the prepare_to_proceed /
deferred_step_ptid code is all about.
However, deferred_step_ptid code resumes the target with:
resume (1, GDB_SIGNAL_0);
prepare_to_wait (ecs);
return;
Recall we were just stepping over a breakpoint when we get here. That
means that _nothing_ had installed breakpoints yet! If there's
another breakpoint just after the breakpoint that was just stepped,
we'll miss it. The fix for that would be to use keep_going instead.
However, there are more problems. What if the instruction that was
just single-stepped triggers a watchpoint? Currently, GDB just
happily resumes the thread, losing that too...
Missed watchpoints will need yet further fixes, but we should keep
those in mind.
So the fix must be to let the trap fall through the regular bpstat
handling, and only if no breakpoint, watchpoint, etc. claims the trap,
shall we switch back to the stepped thread.
Now, nowadays, we have code at the tail end of trap handling that does
exactly that -- switch back to the stepped thread
(switch_back_to_the_stepped_thread).
So the deferred_step_ptid code is just standing in the way, and can
simply be eliminated, fixing bugs in the process. Sweet.
The comment about spurious "Switching to ..." made me pause, but is
actually stale nowadays. That isn't needed anymore.
previous_inferior_ptid used to be re-set at each (internal) event, but
now it's only touched in proceed and normal stop.
The two tests added by this patch fail without the fix.
Tested on x86_64 Fedora 17 (also against my software single-stepping
on x86 branch).
gdb/
2014-03-20 Pedro Alves <palves@redhat.com>
* infrun.c (previous_inferior_ptid): Adjust comment.
(deferred_step_ptid): Delete.
(infrun_thread_ptid_changed, prepare_to_proceed)
(init_wait_for_inferior): Adjust.
(handle_signal_stop): Delete deferred_step_ptid handling.
gdb/testsuite/
2014-03-20 Pedro Alves <palves@redhat.com>
* gdb.threads/step-over-lands-on-breakpoint.c: New file.
* gdb.threads/step-over-lands-on-breakpoint.exp: New file.
Part of PR gdb/13860 is about the mi-solib.exp test's output being
different in sync vs async modes.
sync:
>./gdb -nx -q ./testsuite/gdb.mi/solib-main -ex "set stop-on-solib-events 1" -ex "set target-async off" -i=mi
=thread-group-added,id="i1"
~"Reading symbols from /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/solib-main..."
~"done.\n"
(gdb)
&"start\n"
~"Temporary breakpoint 1 at 0x400608: file ../../../src/gdb/testsuite/gdb.mi/solib-main.c, line 21.\n"
=breakpoint-created,bkpt={number="1",type="breakpoint",disp="del",enabled="y",addr="0x0000000000400608",func="main",file="../../../src/gdb/testsuite/gdb.mi/solib-main.c",fullname="/home/pedro/gdb/mygit/src/gdb/testsuite/gdb.mi/solib-main.c",line="21",times="0",original-location="main"}
~"Starting program: /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/solib-main \n"
=thread-group-started,id="i1",pid="17724"
=thread-created,id="1",group-id="i1"
^running
*running,thread-id="all"
(gdb)
=library-loaded,id="/lib64/ld-linux-x86-64.so.2",target-name="/lib64/ld-linux-x86-64.so.2",host-name="/lib64/ld-linux-x86-64.so.2",symbols-loaded="0",thread-group="i1"
~"Stopped due to shared library event (no libraries added or removed)\n"
*stopped,reason="solib-event",frame={addr="0x000000379180f990",func="_dl_debug_state",args=[],from="/lib64/ld-linux-x86-64.so.2"},thread-id="1",stopped-threads="all",core="3"
(gdb)
async:
>./gdb -nx -q ./testsuite/gdb.mi/solib-main -ex "set stop-on-solib-events 1" -ex "set target-async on" -i=mi
=thread-group-added,id="i1"
~"Reading symbols from /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/solib-main..."
~"done.\n"
(gdb)
start
&"start\n"
~"Temporary breakpoint 1 at 0x400608: file ../../../src/gdb/testsuite/gdb.mi/solib-main.c, line 21.\n"
=breakpoint-created,bkpt={number="1",type="breakpoint",disp="del",enabled="y",addr="0x0000000000400608",func="main",file="../../../src/gdb/testsuite/gdb.mi/solib-main.c",fullname="/home/pedro/gdb/mygit/src/gdb/testsuite/gdb.mi/solib-main.c",line="21",times="0",original-location="main"}
~"Starting program: /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/solib-main \n"
=thread-group-started,id="i1",pid="17729"
=thread-created,id="1",group-id="i1"
^running
*running,thread-id="all"
=library-loaded,id="/lib64/ld-linux-x86-64.so.2",target-name="/lib64/ld-linux-x86-64.so.2",host-name="/lib64/ld-linux-x86-64.so.2",symbols-loaded="0",thread-group="i1"
(gdb)
*stopped,reason="solib-event",thread-id="1",stopped-threads="all",core="1"
For now, let's focus only on the *stopped event. We see that the
async output is missing frame info. And this causes a test failure in
async mode, as "mi_expect_stop solib-event" wants to see the frame
info.
However, if we compare the event output when a real MI execution
command is used, compared to a CLI command (e.g., run vs -exec-run,
next vs -exec-next, etc.), we see:
>./gdb -nx -q ./testsuite/gdb.mi/solib-main -ex "set stop-on-solib-events 1" -ex "set target-async off" -i=mi
=thread-group-added,id="i1"
~"Reading symbols from /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/solib-main..."
~"done.\n"
(gdb)
r
&"r\n"
~"Starting program: /home/pedro/gdb/mygit/build/gdb/testsuite/gdb.mi/solib-main \n"
=thread-group-started,id="i1",pid="17751"
=thread-created,id="1",group-id="i1"
^running
*running,thread-id="all"
(gdb)
=library-loaded,id="/lib64/ld-linux-x86-64.so.2",target-name="/lib64/ld-linux-x86-64.so.2",host-name="/lib64/ld-linux-x86-64.so.2",symbols-loaded="0",thread-group="i1"
~"Stopped due to shared library event (no libraries added or removed)\n"
*stopped,reason="solib-event",frame={addr="0x000000379180f990",func="_dl_debug_state",args=[],from="/lib64/ld-linux-x86-64.so.2"},thread-id="1",stopped-threads="all",core="3"
(gdb)
-exec-run
=thread-exited,id="1",group-id="i1"
=thread-group-exited,id="i1"
=library-unloaded,id="/lib64/ld-linux-x86-64.so.2",target-name="/lib64/ld-linux-x86-64.so.2",host-name="/lib64/ld-linux-x86-64.so.2",thread-group="i1"
=thread-group-started,id="i1",pid="17754"
=thread-created,id="1",group-id="i1"
^running
*running,thread-id="all"
(gdb)
=library-loaded,id="/lib64/ld-linux-x86-64.so.2",target-name="/lib64/ld-linux-x86-64.so.2",host-name="/lib64/ld-linux-x86-64.so.2",symbols-loaded="0",thread-group="i1"
*stopped,reason="solib-event",thread-id="1",stopped-threads="all",core="1"
=thread-selected,id="1"
(gdb)
As seen above, with MI commands, the *stopped event _doesn't_ have
frame info. This is because normal_stop, as commanded by the result
of bpstat_print, skips printing frame info in this case (it's an
"event", not a "breakpoint"), and when the interpreter is MI,
mi_on_normal_stop skips calling print_stack_frame, as the normal_stop
call was already done with the MI uiout. This explains why the async
output is different even with a CLI command. Its because in async
mode, the mi_on_normal_stop path is always taken; it is always reached
with the MI uiout, because the stop is handled from the event loop,
instead of from within `proceed -> wait_for_inferior -> normal_stop'
with the interpreter overridden, as in sync mode.
This patch fixes the issue by making all cases output the same
*stopped event, by factoring out the print code from normal_stop, and
using it from mi_on_normal_stop as well. I chose the *stopped output
without a frame, mainly because that is what you already get if you
use MI execution commands, the commands frontends are supposed to use
(except when implementing a console). This patch makes it simpler to
tweak the MI output differently if desired, as we only have to change
the centralized print_stop_event (taking into account whether the
uiout is MI-like), and all different modes will change accordingly.
Tested on x86_64 Fedora 17, no regressions. The mi-solib.exp test no
longer fails in async mode with this patch, so the patch removes the
kfail.
2014-03-18 Pedro Alves <palves@redhat.com>
PR gdb/13860
* inferior.h (print_stop_event): Declare.
* infrun.c (print_stop_event): New, factored out from ...
(normal_stop): ... this.
* mi/mi-interp.c (mi_on_normal_stop): Use print_stop_event instead
of bpstat_print/print_stack_frame.
2014-03-18 Pedro Alves <palves@redhat.com>
PR gdb/13860
* gdb.mi/mi-solib.exp: Remove gdb/13860 kfail.
* lib/mi-support.exp (mi_expect_stop): Add special handling for
solib-event.
This changes the probes to be independent of the program space.
After this, when a probe's address is needed, it is determined by
applying offsets at the point of use.
This introduces a bound_probe object, similar to bound minimal
symbols. Objects of this type are used when it's necessary to pass a
probe and its corresponding objfile.
This removes the backlink from probe to objfile, which was primarily
used to fetch the architecture to use.
This adds a get_probe_address function which calls a probe method to
compute the probe's relocated address. Similarly, it adds an objfile
parameter to the semaphore methods so they can do the relocation
properly as well.
2014-03-03 Tom Tromey <tromey@redhat.com>
* break-catch-throw.c (fetch_probe_arguments): Use bound probes.
* breakpoint.c (create_longjmp_master_breakpoint): Use
get_probe_address.
(add_location_to_breakpoint, bkpt_probe_insert_location)
(bkpt_probe_remove_location): Update.
* breakpoint.h (struct bp_location) <probe>: Now a bound_probe.
* elfread.c (elf_symfile_relocate_probe): Remove.
(elf_probe_fns): Update.
(insert_exception_resume_breakpoint): Change type of "probe"
parameter to bound_probe.
(check_exception_resume): Update.
* objfiles.c (objfile_relocate1): Don't relocate probes.
* probe.c (bound_probe_s): New typedef.
(parse_probes): Use get_probe_address. Set sal's objfile.
(find_probe_by_pc): Return a bound_probe.
(collect_probes): Return a VEC(bound_probe_s).
(compare_probes): Update.
(gen_ui_out_table_header_info): Change type of "probes"
parameter. Update.
(info_probes_for_ops): Update.
(get_probe_address): New function.
(probe_safe_evaluate_at_pc): Update.
* probe.h (struct probe_ops) <get_probe_address>: New field.
<set_semaphore, clear_semaphore>: Add objfile parameter.
(struct probe) <objfile>: Remove field.
<arch>: New field.
<address>: Update comment.
(struct bound_probe): New.
(find_probe_by_pc): Return a bound_probe.
(get_probe_address): Declare.
* solib-svr4.c (struct probe_and_action) <address>: New field.
(hash_probe_and_action, equal_probe_and_action): Update.
(register_solib_event_probe): Add address parameter.
(solib_event_probe_at): Update.
(svr4_create_probe_breakpoints): Add objfile parameter. Use
get_probe_address.
* stap-probe.c (struct stap_probe) <sem_addr>: Update comment.
(stap_get_probe_address): New function.
(stap_can_evaluate_probe_arguments, compute_probe_arg)
(compile_probe_arg): Update.
(stap_set_semaphore, stap_clear_semaphore): Compute semaphore's
address.
(handle_stap_probe): Don't relocate the probe.
(stap_relocate): Remove.
(stap_gen_info_probes_table_values): Update.
(stap_probe_ops): Remove stap_relocate.
* symfile-debug.c (debug_sym_relocate_probe): Remove.
(debug_sym_probe_fns): Update.
* symfile.h (struct sym_probe_fns) <sym_relocate_probe>: Remove.
* symtab.c (init_sal): Use memset.
* symtab.h (struct symtab_and_line) <objfile>: New field.
* tracepoint.c (start_tracing, stop_tracing): Update.
Say:
<stopped at a breakpoint in thread 2>
(gdb) thread 3
(gdb) step
The above triggers the prepare_to_proceed/deferred_step_ptid process,
which switches back to thread 2, to step over its breakpoint before
getting back to thread 3 and "step" it.
If while stepping over the breakpoint in thread 2, a signal arrives,
and it is set to pass/nostop, we'll set a step-resume breakpoint at
the supposed signal-handler resume address, and call keep_going. The
problem is that we were supposedly stepping thread 3, and that
keep_going delivers a signal to thread 2, and due to scheduler-locking
off, resumes everything else, _including_ thread 3, the thread we want
stepping. This means that we lose control of thread 3 until the next
event, when we stop everything. The end result for the user, is that
GDB lost control of the "step".
Here's the current infrun debug output of the above, with the testcase
in the patch below:
infrun: clear_proceed_status_thread (Thread 0x2aaaab8f5700 (LWP 11663))
infrun: clear_proceed_status_thread (Thread 0x2aaaab6f4700 (LWP 11662))
infrun: clear_proceed_status_thread (Thread 0x2aaaab4f2b20 (LWP 11659))
infrun: proceed (addr=0xffffffffffffffff, signal=144, step=1)
infrun: prepare_to_proceed (step=1), switched to [Thread 0x2aaaab6f4700 (LWP 11662)]
infrun: resume (step=1, signal=0), trap_expected=1, current thread [Thread 0x2aaaab6f4700 (LWP 11662)] at 0x40098f
infrun: wait_for_inferior ()
infrun: target_wait (-1, status) =
infrun: 11659 [Thread 0x2aaaab6f4700 (LWP 11662)],
infrun: status->kind = stopped, signal = SIGUSR1
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x40098f
infrun: random signal 30
Program received signal SIGUSR1, User defined signal 1.
infrun: signal arrived while stepping over breakpoint
infrun: inserting step-resume breakpoint at 0x40098f
infrun: resume (step=0, signal=30), trap_expected=0, current thread [Thread 0x2aaaab6f4700 (LWP 11662)] at 0x40098f
^^^ this is a wildcard resume.
infrun: prepare_to_wait
infrun: target_wait (-1, status) =
infrun: 11659 [Thread 0x2aaaab6f4700 (LWP 11662)],
infrun: status->kind = stopped, signal = SIGTRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x40098f
infrun: BPSTAT_WHAT_STEP_RESUME
infrun: resume (step=1, signal=0), trap_expected=1, current thread [Thread 0x2aaaab6f4700 (LWP 11662)] at 0x40098f
^^^ step-resume hit, meaning the handler returned, so we go back to stepping thread 3.
infrun: prepare_to_wait
infrun: target_wait (-1, status) =
infrun: 11659 [Thread 0x2aaaab6f4700 (LWP 11662)],
infrun: status->kind = stopped, signal = SIGTRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x40088b
infrun: switching back to stepped thread
infrun: Switching context from Thread 0x2aaaab6f4700 (LWP 11662) to Thread 0x2aaaab8f5700 (LWP 11663)
infrun: resume (step=1, signal=0), trap_expected=0, current thread [Thread 0x2aaaab8f5700 (LWP 11663)] at 0x400938
infrun: prepare_to_wait
infrun: target_wait (-1, status) =
infrun: 11659 [Thread 0x2aaaab8f5700 (LWP 11663)],
infrun: status->kind = stopped, signal = SIGTRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x40093a
infrun: keep going
infrun: resume (step=1, signal=0), trap_expected=0, current thread [Thread 0x2aaaab8f5700 (LWP 11663)] at 0x40093a
infrun: prepare_to_wait
infrun: target_wait (-1, status) =
infrun: 11659 [Thread 0x2aaaab8f5700 (LWP 11663)],
infrun: status->kind = stopped, signal = SIGTRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x40091e
infrun: stepped to a different line
infrun: stop_stepping
[Switching to Thread 0x2aaaab8f5700 (LWP 11663)]
69 (*myp) ++; /* set breakpoint child_two here */
^^^ we stopped at the wrong line. We still stepped a bit because the
test is running in a loop, and when we got back to stepping thread 3,
it happened to be in the stepping range. (The loop increments a
counter, and the test makes sure it increments exactly once. Without
the fix, the counter increments a bunch, since the user-stepped thread
runs free without GDB noticing.)
The fix is to switch to the stepping thread before continuing for the
step-resume breakpoint.
gdb/
2014-02-07 Pedro Alves <palves@redhat.com>
* infrun.c (handle_signal_stop) <signal arrives while stepping
over a breakpoint>: Switch back to the stepping thread.
gdb/testsuite/
2014-02-07 Pedro Alves <pedro@codesourcery.com>
Pedro Alves <palves@redhat.com>
* gdb.threads/step-after-sr-lock.c: New file.
* gdb.threads/step-after-sr-lock.exp: New file.
This patch handles another aspect of the ELFv2 ABI, which unfortunately
requires common code changes.
In ELFv2, functions may provide both a global and a local entry point.
The global entry point (where the function symbol points to) is intended
to be used for function-pointer or cross-module (PLT) calls, and requires
r12 to be set up to the entry point address itself. The local entry
point (which is found at a fixed offset after the global entry point,
as defined by bits in the symbol table entries' st_other field), instead
expects r2 to be set up to the current TOC.
Now, when setting a breakpoint on a function by name, you really want
that breakpoint to trigger either way, no matter whether the function
is called via its local or global entry point. Since the global entry
point will always fall through into the local entry point, the way to
achieve that is to simply set the breakpoint at the local entry point.
One way to do that would be to have prologue parsing skip the code
sequence that makes up the global entry point. Unfortunately, this
does not work reliably, since -for optimized code- GDB these days
will not actuall invoke the prologue parsing code but instead just
set the breakpoint at the symbol address and rely on DWARF being
correct at any point throughout the function ...
Unfortunately, I don't really see any way to express the notion of
local entry points with the current set of gdbarch callbacks.
Thus this patch adds a new callback, skip_entrypoint, that is
somewhat analogous to skip_prologue, but is called every time
GDB needs to determine a function start address, even in those
cases where GDB decides to not call skip_prologue.
As a side effect, the skip_entrypoint implementation on ppc64
does not need to perform any instruction parsing; it can simply
rely on the local entry point flags in the symbol table entry.
With this implemented, two test cases would still fail to set
the breakpoint correctly, but that's because they use the construct:
gdb_test "break *hello"
Now, using "*hello" explicitly instructs GDB to set the breakpoint
at the numerical value of "hello" treated as function pointer, so
it will by definition only hit the global entry point.
I think this behaviour is unavoidable, but acceptable -- most people
do not use this construct, and if they do, they get what they
asked for ...
In one of those two test cases, use of this construct is really
not appropriate. I think this was added way back when as a means
to work around prologue skipping problems on some platforms. These
days that shouldn't really be necessary any more ...
For the other (step-bt), we really want to make sure backtracing
works on the very first instruction of the routine. To enable that
test also on powerpc64le-linux, we can modify the code to call the
test function via function pointer (which makes it use the global
entry point in the ELFv2 ABI).
gdb/ChangeLog:
* gdbarch.sh (skip_entrypoint): New callback.
* gdbarch.c, gdbarch.h: Regenerate.
* symtab.c (skip_prologue_sal): Call gdbarch_skip_entrypoint.
* infrun.c (fill_in_stop_func): Likewise.
* ppc-linux-tdep.c: Include "elf/ppc64.h".
(ppc_elfv2_elf_make_msymbol_special): New function.
(ppc_elfv2_skip_entrypoint): Likewise.
(ppc_linux_init_abi): Install them for ELFv2.
gdb/testsuite/ChangeLog:
* gdb.base/sigbpt.exp: Do not use "*" when setting breakpoint
on a function.
* gdb.base/step-bt.c: Call hello via function pointer to make
sure its first instruction is executed on powerpc64le-linux.
RECORD_IS_USED and record_full_open look at current_target.to_stratum
to determine whether a record target is in use. This is wrong because
arch_stratum is greater than record_stratum, so if an arch_stratum
target is pushed, RECORD_IS_USED and record_full_open will miss it.
To fix this, we can use the existing find_record_target instead, which
looks up for a record stratum target across the target stack. Since
that means exporting find_record_target in record.h, RECORD_IS_USED
ends up redundant, so the patch eliminates it.
That exercise then reveals other issues:
- adjust_pc_after_break is gating record_full_... calls based on
RECORD_IS_USED. But, record_full_ calls shouldn't be made when
recording with the record-btrace target. So this adds a new
record_full_is_used predicate to be used in that spot.
- record_full_open says "Process record target already running", even
if the recording target is record-btrace ("process record" is the
original complete name of the record-full target). record_btrace_open
only says "The process is already being recorded." and does not
suggest "record stop", like record-full does. The patch factors out
and merges that error to a new record_preopen function that all record
targets call in their open routine.
Tested on x86_64 Fedora 17.
gdb/
2014-01-14 Pedro Alves <palves@redhat.com>
Tom Tromey <tromey@redhat.com>
* infrun.c (use_displaced_stepping): Use find_record_target
instead of RECORD_IS_USED.
(adjust_pc_after_break): Use record_full_is_used instead of
RECORD_IS_USED.
* record-btrace.c (record_btrace_open): Call record_preopen
instead of checking RECORD_IS_USED.
* record-full.c (record_full_shortname)
(record_full_core_shortname): New globals.
(record_full_is_used): New function.
(find_full_open): Call record_preopen instead of checking
RECORD_IS_USED.
(init_record_full_ops): Set the target's shortname to
record_full_shortname.
(init_record_full_core_ops): Set the target's shortname to
record_full_core_shortname.
* record-full.h (record_full_is_used): Declare.
* record.c (find_record_target): Make extern.
(record_preopen): New function.
* record.h (RECORD_IS_USED): Delete macro.
(find_record_target, record_preopen): Declare functions.
This removes gdb_string.h. This patch is purely mechanical. I
created it by running the two commands:
git rm common/gdb_string.h
perl -pi -e's/"gdb_string.h"/<string.h>/;' *.[chyl] */*.[chyl]
2013-11-18 Tom Tromey <tromey@redhat.com>
* common/gdb_string.h: Remove.
* aarch64-tdep.c: Use string.h, not gdb_string.h.
* ada-exp.y: Use string.h, not gdb_string.h.
* ada-lang.c: Use string.h, not gdb_string.h.
* ada-lex.l: Use string.h, not gdb_string.h.
* ada-typeprint.c: Use string.h, not gdb_string.h.
* ada-valprint.c: Use string.h, not gdb_string.h.
* aix-thread.c: Use string.h, not gdb_string.h.
* alpha-linux-tdep.c: Use string.h, not gdb_string.h.
* alpha-mdebug-tdep.c: Use string.h, not gdb_string.h.
* alpha-nat.c: Use string.h, not gdb_string.h.
* alpha-osf1-tdep.c: Use string.h, not gdb_string.h.
* alpha-tdep.c: Use string.h, not gdb_string.h.
* alphanbsd-tdep.c: Use string.h, not gdb_string.h.
* amd64-dicos-tdep.c: Use string.h, not gdb_string.h.
* amd64-linux-nat.c: Use string.h, not gdb_string.h.
* amd64-linux-tdep.c: Use string.h, not gdb_string.h.
* amd64-nat.c: Use string.h, not gdb_string.h.
* amd64-sol2-tdep.c: Use string.h, not gdb_string.h.
* amd64fbsd-tdep.c: Use string.h, not gdb_string.h.
* amd64obsd-tdep.c: Use string.h, not gdb_string.h.
* arch-utils.c: Use string.h, not gdb_string.h.
* arm-linux-nat.c: Use string.h, not gdb_string.h.
* arm-linux-tdep.c: Use string.h, not gdb_string.h.
* arm-tdep.c: Use string.h, not gdb_string.h.
* arm-wince-tdep.c: Use string.h, not gdb_string.h.
* armbsd-tdep.c: Use string.h, not gdb_string.h.
* armnbsd-nat.c: Use string.h, not gdb_string.h.
* armnbsd-tdep.c: Use string.h, not gdb_string.h.
* armobsd-tdep.c: Use string.h, not gdb_string.h.
* avr-tdep.c: Use string.h, not gdb_string.h.
* ax-gdb.c: Use string.h, not gdb_string.h.
* ax-general.c: Use string.h, not gdb_string.h.
* bcache.c: Use string.h, not gdb_string.h.
* bfin-tdep.c: Use string.h, not gdb_string.h.
* breakpoint.c: Use string.h, not gdb_string.h.
* build-id.c: Use string.h, not gdb_string.h.
* buildsym.c: Use string.h, not gdb_string.h.
* c-exp.y: Use string.h, not gdb_string.h.
* c-lang.c: Use string.h, not gdb_string.h.
* c-typeprint.c: Use string.h, not gdb_string.h.
* c-valprint.c: Use string.h, not gdb_string.h.
* charset.c: Use string.h, not gdb_string.h.
* cli-out.c: Use string.h, not gdb_string.h.
* cli/cli-cmds.c: Use string.h, not gdb_string.h.
* cli/cli-decode.c: Use string.h, not gdb_string.h.
* cli/cli-dump.c: Use string.h, not gdb_string.h.
* cli/cli-interp.c: Use string.h, not gdb_string.h.
* cli/cli-logging.c: Use string.h, not gdb_string.h.
* cli/cli-script.c: Use string.h, not gdb_string.h.
* cli/cli-setshow.c: Use string.h, not gdb_string.h.
* cli/cli-utils.c: Use string.h, not gdb_string.h.
* coffread.c: Use string.h, not gdb_string.h.
* common/common-utils.c: Use string.h, not gdb_string.h.
* common/filestuff.c: Use string.h, not gdb_string.h.
* common/linux-procfs.c: Use string.h, not gdb_string.h.
* common/linux-ptrace.c: Use string.h, not gdb_string.h.
* common/signals.c: Use string.h, not gdb_string.h.
* common/vec.h: Use string.h, not gdb_string.h.
* core-regset.c: Use string.h, not gdb_string.h.
* corefile.c: Use string.h, not gdb_string.h.
* corelow.c: Use string.h, not gdb_string.h.
* cp-abi.c: Use string.h, not gdb_string.h.
* cp-support.c: Use string.h, not gdb_string.h.
* cp-valprint.c: Use string.h, not gdb_string.h.
* cris-tdep.c: Use string.h, not gdb_string.h.
* d-lang.c: Use string.h, not gdb_string.h.
* dbxread.c: Use string.h, not gdb_string.h.
* dcache.c: Use string.h, not gdb_string.h.
* demangle.c: Use string.h, not gdb_string.h.
* dicos-tdep.c: Use string.h, not gdb_string.h.
* disasm.c: Use string.h, not gdb_string.h.
* doublest.c: Use string.h, not gdb_string.h.
* dsrec.c: Use string.h, not gdb_string.h.
* dummy-frame.c: Use string.h, not gdb_string.h.
* dwarf2-frame.c: Use string.h, not gdb_string.h.
* dwarf2loc.c: Use string.h, not gdb_string.h.
* dwarf2read.c: Use string.h, not gdb_string.h.
* elfread.c: Use string.h, not gdb_string.h.
* environ.c: Use string.h, not gdb_string.h.
* eval.c: Use string.h, not gdb_string.h.
* event-loop.c: Use string.h, not gdb_string.h.
* exceptions.c: Use string.h, not gdb_string.h.
* exec.c: Use string.h, not gdb_string.h.
* expprint.c: Use string.h, not gdb_string.h.
* f-exp.y: Use string.h, not gdb_string.h.
* f-lang.c: Use string.h, not gdb_string.h.
* f-typeprint.c: Use string.h, not gdb_string.h.
* f-valprint.c: Use string.h, not gdb_string.h.
* fbsd-nat.c: Use string.h, not gdb_string.h.
* findcmd.c: Use string.h, not gdb_string.h.
* findvar.c: Use string.h, not gdb_string.h.
* fork-child.c: Use string.h, not gdb_string.h.
* frame.c: Use string.h, not gdb_string.h.
* frv-linux-tdep.c: Use string.h, not gdb_string.h.
* frv-tdep.c: Use string.h, not gdb_string.h.
* gdb.c: Use string.h, not gdb_string.h.
* gdb_bfd.c: Use string.h, not gdb_string.h.
* gdbarch.c: Use string.h, not gdb_string.h.
* gdbtypes.c: Use string.h, not gdb_string.h.
* gnu-nat.c: Use string.h, not gdb_string.h.
* gnu-v2-abi.c: Use string.h, not gdb_string.h.
* gnu-v3-abi.c: Use string.h, not gdb_string.h.
* go-exp.y: Use string.h, not gdb_string.h.
* go-lang.c: Use string.h, not gdb_string.h.
* go32-nat.c: Use string.h, not gdb_string.h.
* hppa-hpux-tdep.c: Use string.h, not gdb_string.h.
* hppa-linux-nat.c: Use string.h, not gdb_string.h.
* hppanbsd-tdep.c: Use string.h, not gdb_string.h.
* hppaobsd-tdep.c: Use string.h, not gdb_string.h.
* i386-cygwin-tdep.c: Use string.h, not gdb_string.h.
* i386-dicos-tdep.c: Use string.h, not gdb_string.h.
* i386-linux-nat.c: Use string.h, not gdb_string.h.
* i386-linux-tdep.c: Use string.h, not gdb_string.h.
* i386-nto-tdep.c: Use string.h, not gdb_string.h.
* i386-sol2-tdep.c: Use string.h, not gdb_string.h.
* i386-tdep.c: Use string.h, not gdb_string.h.
* i386bsd-tdep.c: Use string.h, not gdb_string.h.
* i386gnu-nat.c: Use string.h, not gdb_string.h.
* i386nbsd-tdep.c: Use string.h, not gdb_string.h.
* i386obsd-tdep.c: Use string.h, not gdb_string.h.
* i387-tdep.c: Use string.h, not gdb_string.h.
* ia64-libunwind-tdep.c: Use string.h, not gdb_string.h.
* ia64-linux-nat.c: Use string.h, not gdb_string.h.
* inf-child.c: Use string.h, not gdb_string.h.
* inf-ptrace.c: Use string.h, not gdb_string.h.
* inf-ttrace.c: Use string.h, not gdb_string.h.
* infcall.c: Use string.h, not gdb_string.h.
* infcmd.c: Use string.h, not gdb_string.h.
* inflow.c: Use string.h, not gdb_string.h.
* infrun.c: Use string.h, not gdb_string.h.
* interps.c: Use string.h, not gdb_string.h.
* iq2000-tdep.c: Use string.h, not gdb_string.h.
* irix5-nat.c: Use string.h, not gdb_string.h.
* jv-exp.y: Use string.h, not gdb_string.h.
* jv-lang.c: Use string.h, not gdb_string.h.
* jv-typeprint.c: Use string.h, not gdb_string.h.
* jv-valprint.c: Use string.h, not gdb_string.h.
* language.c: Use string.h, not gdb_string.h.
* linux-fork.c: Use string.h, not gdb_string.h.
* linux-nat.c: Use string.h, not gdb_string.h.
* lm32-tdep.c: Use string.h, not gdb_string.h.
* m2-exp.y: Use string.h, not gdb_string.h.
* m2-typeprint.c: Use string.h, not gdb_string.h.
* m32c-tdep.c: Use string.h, not gdb_string.h.
* m32r-linux-nat.c: Use string.h, not gdb_string.h.
* m32r-linux-tdep.c: Use string.h, not gdb_string.h.
* m32r-rom.c: Use string.h, not gdb_string.h.
* m32r-tdep.c: Use string.h, not gdb_string.h.
* m68hc11-tdep.c: Use string.h, not gdb_string.h.
* m68k-tdep.c: Use string.h, not gdb_string.h.
* m68kbsd-tdep.c: Use string.h, not gdb_string.h.
* m68klinux-nat.c: Use string.h, not gdb_string.h.
* m68klinux-tdep.c: Use string.h, not gdb_string.h.
* m88k-tdep.c: Use string.h, not gdb_string.h.
* macrocmd.c: Use string.h, not gdb_string.h.
* main.c: Use string.h, not gdb_string.h.
* mdebugread.c: Use string.h, not gdb_string.h.
* mem-break.c: Use string.h, not gdb_string.h.
* memattr.c: Use string.h, not gdb_string.h.
* memory-map.c: Use string.h, not gdb_string.h.
* mep-tdep.c: Use string.h, not gdb_string.h.
* mi/mi-cmd-break.c: Use string.h, not gdb_string.h.
* mi/mi-cmd-disas.c: Use string.h, not gdb_string.h.
* mi/mi-cmd-env.c: Use string.h, not gdb_string.h.
* mi/mi-cmd-stack.c: Use string.h, not gdb_string.h.
* mi/mi-cmd-var.c: Use string.h, not gdb_string.h.
* mi/mi-cmds.c: Use string.h, not gdb_string.h.
* mi/mi-console.c: Use string.h, not gdb_string.h.
* mi/mi-getopt.c: Use string.h, not gdb_string.h.
* mi/mi-interp.c: Use string.h, not gdb_string.h.
* mi/mi-main.c: Use string.h, not gdb_string.h.
* mi/mi-parse.c: Use string.h, not gdb_string.h.
* microblaze-rom.c: Use string.h, not gdb_string.h.
* microblaze-tdep.c: Use string.h, not gdb_string.h.
* mingw-hdep.c: Use string.h, not gdb_string.h.
* minidebug.c: Use string.h, not gdb_string.h.
* minsyms.c: Use string.h, not gdb_string.h.
* mips-irix-tdep.c: Use string.h, not gdb_string.h.
* mips-linux-tdep.c: Use string.h, not gdb_string.h.
* mips-tdep.c: Use string.h, not gdb_string.h.
* mips64obsd-tdep.c: Use string.h, not gdb_string.h.
* mipsnbsd-tdep.c: Use string.h, not gdb_string.h.
* mipsread.c: Use string.h, not gdb_string.h.
* mn10300-linux-tdep.c: Use string.h, not gdb_string.h.
* mn10300-tdep.c: Use string.h, not gdb_string.h.
* monitor.c: Use string.h, not gdb_string.h.
* moxie-tdep.c: Use string.h, not gdb_string.h.
* mt-tdep.c: Use string.h, not gdb_string.h.
* nbsd-tdep.c: Use string.h, not gdb_string.h.
* nios2-linux-tdep.c: Use string.h, not gdb_string.h.
* nto-procfs.c: Use string.h, not gdb_string.h.
* nto-tdep.c: Use string.h, not gdb_string.h.
* objc-lang.c: Use string.h, not gdb_string.h.
* objfiles.c: Use string.h, not gdb_string.h.
* opencl-lang.c: Use string.h, not gdb_string.h.
* osabi.c: Use string.h, not gdb_string.h.
* osdata.c: Use string.h, not gdb_string.h.
* p-exp.y: Use string.h, not gdb_string.h.
* p-lang.c: Use string.h, not gdb_string.h.
* p-typeprint.c: Use string.h, not gdb_string.h.
* parse.c: Use string.h, not gdb_string.h.
* posix-hdep.c: Use string.h, not gdb_string.h.
* ppc-linux-nat.c: Use string.h, not gdb_string.h.
* ppc-sysv-tdep.c: Use string.h, not gdb_string.h.
* ppcfbsd-tdep.c: Use string.h, not gdb_string.h.
* ppcnbsd-tdep.c: Use string.h, not gdb_string.h.
* ppcobsd-tdep.c: Use string.h, not gdb_string.h.
* printcmd.c: Use string.h, not gdb_string.h.
* procfs.c: Use string.h, not gdb_string.h.
* prologue-value.c: Use string.h, not gdb_string.h.
* python/py-auto-load.c: Use string.h, not gdb_string.h.
* python/py-gdb-readline.c: Use string.h, not gdb_string.h.
* ravenscar-thread.c: Use string.h, not gdb_string.h.
* regcache.c: Use string.h, not gdb_string.h.
* registry.c: Use string.h, not gdb_string.h.
* remote-fileio.c: Use string.h, not gdb_string.h.
* remote-m32r-sdi.c: Use string.h, not gdb_string.h.
* remote-mips.c: Use string.h, not gdb_string.h.
* remote-sim.c: Use string.h, not gdb_string.h.
* remote.c: Use string.h, not gdb_string.h.
* reverse.c: Use string.h, not gdb_string.h.
* rs6000-aix-tdep.c: Use string.h, not gdb_string.h.
* ser-base.c: Use string.h, not gdb_string.h.
* ser-go32.c: Use string.h, not gdb_string.h.
* ser-mingw.c: Use string.h, not gdb_string.h.
* ser-pipe.c: Use string.h, not gdb_string.h.
* ser-tcp.c: Use string.h, not gdb_string.h.
* ser-unix.c: Use string.h, not gdb_string.h.
* serial.c: Use string.h, not gdb_string.h.
* sh-tdep.c: Use string.h, not gdb_string.h.
* sh64-tdep.c: Use string.h, not gdb_string.h.
* shnbsd-tdep.c: Use string.h, not gdb_string.h.
* skip.c: Use string.h, not gdb_string.h.
* sol-thread.c: Use string.h, not gdb_string.h.
* solib-dsbt.c: Use string.h, not gdb_string.h.
* solib-frv.c: Use string.h, not gdb_string.h.
* solib-osf.c: Use string.h, not gdb_string.h.
* solib-spu.c: Use string.h, not gdb_string.h.
* solib-target.c: Use string.h, not gdb_string.h.
* solib.c: Use string.h, not gdb_string.h.
* somread.c: Use string.h, not gdb_string.h.
* source.c: Use string.h, not gdb_string.h.
* sparc-nat.c: Use string.h, not gdb_string.h.
* sparc-sol2-tdep.c: Use string.h, not gdb_string.h.
* sparc-tdep.c: Use string.h, not gdb_string.h.
* sparc64-tdep.c: Use string.h, not gdb_string.h.
* sparc64fbsd-tdep.c: Use string.h, not gdb_string.h.
* sparc64nbsd-tdep.c: Use string.h, not gdb_string.h.
* sparcnbsd-tdep.c: Use string.h, not gdb_string.h.
* spu-linux-nat.c: Use string.h, not gdb_string.h.
* spu-multiarch.c: Use string.h, not gdb_string.h.
* spu-tdep.c: Use string.h, not gdb_string.h.
* stabsread.c: Use string.h, not gdb_string.h.
* stack.c: Use string.h, not gdb_string.h.
* std-regs.c: Use string.h, not gdb_string.h.
* symfile.c: Use string.h, not gdb_string.h.
* symmisc.c: Use string.h, not gdb_string.h.
* symtab.c: Use string.h, not gdb_string.h.
* target.c: Use string.h, not gdb_string.h.
* thread.c: Use string.h, not gdb_string.h.
* tilegx-linux-nat.c: Use string.h, not gdb_string.h.
* tilegx-tdep.c: Use string.h, not gdb_string.h.
* top.c: Use string.h, not gdb_string.h.
* tracepoint.c: Use string.h, not gdb_string.h.
* tui/tui-command.c: Use string.h, not gdb_string.h.
* tui/tui-data.c: Use string.h, not gdb_string.h.
* tui/tui-disasm.c: Use string.h, not gdb_string.h.
* tui/tui-file.c: Use string.h, not gdb_string.h.
* tui/tui-layout.c: Use string.h, not gdb_string.h.
* tui/tui-out.c: Use string.h, not gdb_string.h.
* tui/tui-regs.c: Use string.h, not gdb_string.h.
* tui/tui-source.c: Use string.h, not gdb_string.h.
* tui/tui-stack.c: Use string.h, not gdb_string.h.
* tui/tui-win.c: Use string.h, not gdb_string.h.
* tui/tui-windata.c: Use string.h, not gdb_string.h.
* tui/tui-winsource.c: Use string.h, not gdb_string.h.
* typeprint.c: Use string.h, not gdb_string.h.
* ui-file.c: Use string.h, not gdb_string.h.
* ui-out.c: Use string.h, not gdb_string.h.
* user-regs.c: Use string.h, not gdb_string.h.
* utils.c: Use string.h, not gdb_string.h.
* v850-tdep.c: Use string.h, not gdb_string.h.
* valarith.c: Use string.h, not gdb_string.h.
* valops.c: Use string.h, not gdb_string.h.
* valprint.c: Use string.h, not gdb_string.h.
* value.c: Use string.h, not gdb_string.h.
* varobj.c: Use string.h, not gdb_string.h.
* vax-tdep.c: Use string.h, not gdb_string.h.
* vaxnbsd-tdep.c: Use string.h, not gdb_string.h.
* vaxobsd-tdep.c: Use string.h, not gdb_string.h.
* windows-nat.c: Use string.h, not gdb_string.h.
* xcoffread.c: Use string.h, not gdb_string.h.
* xml-support.c: Use string.h, not gdb_string.h.
* xstormy16-tdep.c: Use string.h, not gdb_string.h.
* xtensa-linux-nat.c: Use string.h, not gdb_string.h.
Before all this stop_soon handling, we have code that can end in
keep_going. Particularly, the thread_hop_needed code looked
suspicious considering breakpoint always-inserted mode, though on
closer inspection, it'd take connecting to multiple remote targets
that shared the same address space to trigger that.
Still, I think it's clearer if all this remote connection setup /
attach code is placed early, before any keep_going path could be
reached.
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* infrun.c (handle_signal_stop): Move STOP_QUIETLY,
STOP_QUIETLY_REMOTE and 'stop_after_trap' handling earlier.
After the previous patches, we only ever reach the code after the
initial 'switch (ecs->ws.kind)' switch for TARGET_WAITKIND_STOPPED.
We can now factor out all that to its own function.
Unfortunately, stepped_after_stopped_by_watchpoint needed to move to
the ecs. I think that indicates a state machine bug -- no event other
than TARGET_WAITKIND_STOPPED indicates a single-step actually
finished. TARGET_WAITKIND_SYSCALL_XXX, TARGET_WAITKIND_FORK, etc. are
all events that are triggered from the kernel, _within_ a syscall,
IOW, from userspace's perspective, halfway through an instruction
being executed. This might actually matter for the syscall events, as
syscalls can change memory (and thus trigger watchpoints).
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* infrun.c (struct execution_control_state)
<stepped_after_stopped_by_watchpoint>: New field.
(get_inferior_stop_soon): New function.
(handle_inferior_event): 'stepped_after_stopped_by_watchpoint' was
moved to struct execution_control_state -- adjust. Use
get_inferior_stop_soon. Split TARGET_WAITKIND_STOPPED handling to
new function.
(handle_signal_stop): New function, factored out from
handle_inferior_event.
After the previous patch, there's actually no breakpoint type that
returns BPSTAT_SIGNAL_HIDE, so we can go back to having
bpstat_explains_signal return a boolean. The signal hiding actually
disappears.
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* break-catch-sig.c (signal_catchpoint_explains_signal): Adjust to
return a boolean.
* breakpoint.c (bpstat_explains_signal): Adjust to return a
boolean.
(explains_signal_watchpoint, base_breakpoint_explains_signal):
Adjust to return a boolean.
* breakpoint.h (enum bpstat_signal_value): Delete.
(struct breakpoint_ops) <explains_signal>: New returns a boolean.
(bpstat_explains_signal): Likewise.
* infrun.c (handle_inferior_event) <random signal checks>:
bpstat_explains_signal now returns a boolean - adjust. No longer
consider hiding signals.
Looking at the current random signal checks:
if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
random_signal
= !((bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
GDB_SIGNAL_TRAP)
!= BPSTAT_SIGNAL_NO)
|| stopped_by_watchpoint
|| ecs->event_thread->control.trap_expected
|| (ecs->event_thread->control.step_range_end
&& (ecs->event_thread->control.step_resume_breakpoint
== NULL)));
else
{
enum bpstat_signal_value sval;
sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
ecs->event_thread->suspend.stop_signal);
random_signal = (sval == BPSTAT_SIGNAL_NO);
if (sval == BPSTAT_SIGNAL_HIDE)
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
}
We can observe:
- the stepping checks bit:
...
|| ecs->event_thread->control.trap_expected
|| (ecs->event_thread->control.step_range_end
&& (ecs->event_thread->control.step_resume_breakpoint
== NULL)));
...
is just like currently_stepping:
static int
currently_stepping (struct thread_info *tp)
{
return ((tp->control.step_range_end
&& tp->control.step_resume_breakpoint == NULL)
|| tp->control.trap_expected
|| bpstat_should_step ());
}
except it misses the bpstat_should_step check (***).
It's not really necessary to check bpstat_should_step in the
random signal tests, because software watchpoints always end up in
the bpstat list anyway, which means bpstat_explains_signal with
GDB_SIGNAL_TRAP always returns at least BPSSTAT_SIGNAL_HIDE, but I
think the code is clearer if we reuse currently_stepping.
*** - bpstat_should_step checks to see if there's any software
watchpoint in the breakpoint list, because we need to force the
target to single-step all the way, to evaluate the watchpoint's
value at each step.
- we never hide GDB_SIGNAL_TRAP, even if the bpstat returns
BPSTAT_SIGNAL_HIDE, which is actually the default for all
breakpoints. If we make the default be BPSTAT_SIGNAL_PASS, then
we can merge the two bpstat_explains_signal paths.
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* breakpoint.c (bpstat_explains_signal) <Moribund locations>:
Return BPSTAT_SIGNAL_PASS instead of BPSTAT_SIGNAL_HIDE.
(explains_signal_watchpoint): Return BPSTAT_SIGNAL_PASS instead of
BPSTAT_SIGNAL_HIDE.
(base_breakpoint_explains_signal): Return BPSTAT_SIGNAL_PASS
instead of BPSTAT_SIGNAL_HIDE.
* infrun.c (handle_inferior_event): Rework random signal checks.
This goes a step forward in making only TARGET_WAITKIND_STOPPED talk
about signals.
There's no reason for the "catchpoint" TARGET_WAITKIND_XXXs to consult
bpstat about signals -- unlike breakpoints, all these events are
continuable, so we don't need to do a remove-break/step/reinsert-break
-like dance. That means we don't actually need to run them through
process_event_stop_test (for the bpstat_what checks), and can just use
bpstat_causes_stop instead. Note we were already using it in the
TARGET_WAITKIND_(V)FORKED cases.
Then, these "catchpoint" waitkinds don't need to set
ecs->random_signal for anything, because they check it immediately
afterwards (and the value they set is never used again).
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* infrun.c (struct execution_control_state): Remove
'random_signal' field.
(handle_syscall_event): Use bpstat_causes_stop instead of
bpstat_explains_signal. Don't set ecs->random_signal.
(handle_inferior_event): New 'random_signal' local.
<TARGET_WAITKIND_FORKED, TARGET_WAITKIND_VFORKED,
TARGET_WAITKIND_EXECD>: Use bpstat_causes_stop instead of
bpstat_explains_signal. Don't set ecs->random_signal.
<TARGET_WAITKIND_STOPPED>: Adjust to use local instead of
ecs->random_signal.
This comment applies to the whole handle_inferior_event flow, top to
bottom. Best move it to the function's intro.
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* infrun.c (handle_inferior_event): Move comment from the
function's body to the function's description, adjusted.
Of all the TARGET_WAITKIND_XXXs event kinds other than
TARGET_WAITKIND_STOPPED, TARGET_WAITKIND_LOADED is the only kind that
doesn't end in a return, instead falling through to all the
signal/breakpoint/stepping handling code. But it only falls through
in the STOP_QUIETLY_NO_SIGSTOP and STOP_QUIETLY_REMOTE cases, which
means the
/* This is originated from start_remote(), start_inferior() and
shared libraries hook functions. */
if (stop_soon == STOP_QUIETLY || stop_soon == STOP_QUIETLY_REMOTE)
{
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: quietly stopped\n");
stop_stepping (ecs);
return;
}
bit is eventually reached. All tests before that is reached will
always fail. It's simpler to inline the stop_soon checks close to the
TARGET_WAITKIND_LOADED code, which allows removing the fall through.
Tested on x86_64 Fedora 17, but that doesn't exercise this
TARGET_WAITKIND_LOADED.
Also ran gdb.base/solib-disc.exp on Cygwin/gdbserver, which exercises
reconnection while the inferior is stopped at an solib event, but then
again, gdbserver always replies a regular trap on initial connection,
instead of the last event the program had seen:
Sending packet: $?#3f...Packet received: T0505:4ca72800;04:f8a62800;08:62fcc877;thread:d28;
Sending packet: $Hc-1#09...Packet received: E01
Sending packet: $qAttached#8f...Packet received: 0
Packet qAttached (query-attached) is supported
infrun: clear_proceed_status_thread (Thread 3368)
Sending packet: $qOffsets#4b...Packet received:
infrun: wait_for_inferior ()
infrun: target_wait (-1, status) =
infrun: 42000 [Thread 3368],
infrun: status->kind = stopped, signal = GDB_SIGNAL_TRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x77c8fc62
infrun: quietly stopped
infrun: stop_stepping
So the only way to exercise this would be to hack gdbserver. I didn't
go that far though. I'm reasonably confident this is correct.
gdb/
2013-11-14 Pedro Alves <palves@redhat.com>
* infrun.c (handle_inferior_event) <TARGET_WAITKIND_LOADED>:
Handle STOP_QUIETLY_NO_SIGSTOP and STOP_QUIETLY_REMOTE here.
Assert we never fall through out of the TARGET_WAITKIND_LOADED
case.
IMO, it doesn't make sense to map random syscall, fork, etc. events to
GDB_SIGNAL_TRAP, and possible have the debuggee see that trap. This
just seems conceptually wrong to me - these aren't real signals a
debuggee would ever see. In fact, when stopped for those events, on
Linux, the debuggee isn't in a signal-stop -- there's no way to
resume-and-deliver-signal at that point, for example. E.g., when
stopped at a fork event:
(gdb) catch fork
Catchpoint 2 (fork)
(gdb) c
Continuing.
Catchpoint 2 (forked process 4570), 0x000000323d4ba7c4 in __libc_fork () at ../nptl/sysdeps/unix/sysv/linux/fork.c:131
131 pid = ARCH_FORK ();
(gdb) set debug infrun 1
(gdb) signal SIGTRAP
Continuing with signal SIGTRAP.
infrun: clear_proceed_status_thread (process 4566)
infrun: proceed (addr=0xffffffffffffffff, signal=5, step=0)
infrun: resume (step=0, signal=5), trap_expected=0, current thread [process 4566] at 0x323d4ba7c4
infrun: wait_for_inferior ()
infrun: target_wait (-1, status) =
infrun: 4566 [process 4566],
infrun: status->kind = exited, status = 0
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_EXITED
[Inferior 1 (process 4566) exited normally]
infrun: stop_stepping
(gdb)
Note the signal went nowhere. It was swallowed.
Resuming with a SIGTRAP from a syscall event does queue the signal,
but doesn't deliver it immediately, like "signal SIGTRAP" from a real
signal would. It's still an artificial SIGTRAP:
(gdb) catch syscall
Catchpoint 2 (any syscall)
(gdb) c
Continuing.
Catchpoint 2 (call to syscall clone), 0x000000323d4ba7c4 in __libc_fork () at ../nptl/sysdeps/unix/sysv/linux/fork.c:131
131 pid = ARCH_FORK ();
(gdb) set debug infrun 1
(gdb) signal SIGTRAP
Continuing with signal SIGTRAP.
infrun: clear_proceed_status_thread (process 4622)
infrun: proceed (addr=0xffffffffffffffff, signal=5, step=0)
infrun: resume (step=0, signal=5), trap_expected=0, current thread [process 4622] at 0x323d4ba7c4
infrun: wait_for_inferior ()
infrun: target_wait (-1, status) =
infrun: 4622 [process 4622],
infrun: status->kind = exited syscall
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_SYSCALL_RETURN
infrun: syscall number = '56'
infrun: BPSTAT_WHAT_STOP_NOISY
infrun: stop_stepping
Catchpoint 2 (returned from syscall clone), 0x000000323d4ba7c4 in __libc_fork () at ../nptl/sysdeps/unix/sysv/linux/fork.c:131
131 pid = ARCH_FORK ();
(gdb) c
Continuing.
infrun: clear_proceed_status_thread (process 4622)
infrun: proceed (addr=0xffffffffffffffff, signal=144, step=0)
infrun: resume (step=0, signal=0), trap_expected=0, current thread [process 4622] at 0x323d4ba7c4
infrun: wait_for_inferior ()
infrun: target_wait (-1, status) =
infrun: 4622 [process 4622],
infrun: status->kind = stopped, signal = SIGTRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4ba7c4
infrun: random signal 5
Program received signal SIGTRAP, Trace/breakpoint trap.
infrun: stop_stepping
0x000000323d4ba7c4 in __libc_fork () at ../nptl/sysdeps/unix/sysv/linux/fork.c:131
131 pid = ARCH_FORK ();
(gdb)
In all the above, I used 'signal SIGTRAP' to emulate 'handle SIGTRAP
pass'. As described in "keep_going", 'handle SIGTRAP pass' does have
its place:
/* Do not deliver GDB_SIGNAL_TRAP (except when the user
explicitly specifies that such a signal should be delivered
to the target program). Typically, that would occur when a
user is debugging a target monitor on a simulator: the target
monitor sets a breakpoint; the simulator encounters this
breakpoint and halts the simulation handing control to GDB;
GDB, noting that the stop address doesn't map to any known
breakpoint, returns control back to the simulator; the
simulator then delivers the hardware equivalent of a
GDB_SIGNAL_TRAP to the program being debugged. */
... and I've made use of that myself when implementing/debugging
stubs/monitors. But in these cases, treating these events as SIGTRAP
possibly injects signals in the debuggee they'd never see otherwise,
because you need to use ptrace to enable these special events, which
aren't real signals.
There's more. Take this bit of handle_inferior_event, where we
determine whether a real signal (TARGET_WAITKIND_STOPPED) was random
or not:
if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
ecs->random_signal
= !((bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
GDB_SIGNAL_TRAP)
!= BPSTAT_SIGNAL_NO)
|| stopped_by_watchpoint
|| ecs->event_thread->control.trap_expected
|| (ecs->event_thread->control.step_range_end
&& (ecs->event_thread->control.step_resume_breakpoint
== NULL)));
else
{
enum bpstat_signal_value sval;
sval = bpstat_explains_signal (ecs->event_thread->control.stop_bpstat,
ecs->event_thread->suspend.stop_signal);
ecs->random_signal = (sval == BPSTAT_SIGNAL_NO);
if (sval == BPSTAT_SIGNAL_HIDE)
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
}
Note that the
if (sval == BPSTAT_SIGNAL_HIDE)
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_TRAP;
bit is only reacheable for signals != GDB_SIGNAL_TRAP. AFAICS, sval
can only be BPSTAT_SIGNAL_HIDE if nothing in the bpstat returns
BPSTAT_SIGNAL_PASS. So that excludes a "catch signal" for the signal
in question in the bpstat. All other catchpoints that aren't based on
breakpoints behind the scenes call process_event_stop_test directly
(don't pass through here) (well, almost all: TARGET_WAITKIND_LOADED
does have a fall through, but only for STOP_QUIETLY or
STOP_QUIETLY_NO_SIGSTOP, which still return before this code is
reached). Catchpoints that are implemented as breakpoints behind the
scenes can only appear in the bpstat if the signal was GDB_SIGNAL_TRAP
(bkpt_breakpoint_hit returns false otherwise). So that leaves a
target reporting a hardware watchpoint hit with a signal other than
GDB_SIGNAL_TRAP. And even then it looks quite wrong to me to
magically convert the signal into a GDB_SIGNAL_TRAP here too -- if the
user has set SIGTRAP to "handle pass", the program will see a trap
that gdb invented, not one the program would ever see without gdb in
the picture.
Tested on x86_64 Fedora 17.
gdb/
2013-10-31 Pedro Alves <palves@redhat.com>
* infrun.c (handle_syscall_event): Don't set or clear stop_signal.
(handle_inferior_event) <TARGET_WAITKIND_FORKED,
TARGET_WAITKIND_VFORKED>: Don't set stop_signal to
GDB_SIGNAL_TRAP, or clear it. Pass GDB_SIGNAL_0 to
bpstat_explains signal, instead of GDB_SIGNAL_TRAP.
<bpstat handling>: If the bpstat chain wants the signal to be
hidden, then set stop_signal to GDB_SIGNAL_0 instead of
GDB_SIGNAL_TRAP.
Now that all ecs->random_signal handing is always done before the
'process_event_stop_test' label, we can easily make that a real
function and actually give it a describing comment that somewhat makes
sense.
Reindenting the new function will be handled in a follow up patch.
2013-10-28 Pedro Alves <palves@redhat.com>
* infrun.c (process_event_stop_test): New function, factored out
from handle_inferior_event.
(handle_inferior_event): 'process_event_stop_test' is now a
function instead of a goto label -- adjust.
We only ever call "goto process_event_stop_test;" right after checking
that ecs->random_signal is clear. The code at the
process_event_stop_test label looks like:
/* For the program's own signals, act according to
the signal handling tables. */
if (ecs->random_signal)
{
... random signal handling ...
return;
}
else
{
... the stop tests that actually matter for the goto callers.
}
So this moves the label into the else branch. It'll make converting
process_event_stop_test into a function a bit clearer.
gdb/
2013-10-28 Pedro Alves <palves@redhat.com>
* infrun.c (handle_inferior_event): Move process_event_stop_test
goto label to the else branch of the ecs->random_signal check,
along with FRAME and GDBARCH re-fetching.
I recently added a new ecs->random_signal test after the "switch back to
stepped thread" code, and before the stepping tests. Looking at
making process_event_stop_test a proper function, I realized it'd be
better to keep ecs->random_signal related code together. To do that,
I needed to factor out the "switch back to stepped thread" code to a new
function, and call it in both the "random signal" and "not random
signal" paths.
gdb/
2013-10-28 Pedro Alves <palves@redhat.com>
* infrun.c (switch_back_to_stepped_thread): New function, factored
out from handle_inferior_event.
(handle_inferior_event): Adjust to call
switch_back_to_stepped_thread. Call it also at the tail of the
random signal handling, and return, instead of also handling
random signals just before the stepping tests.
'ecs' is always memset before being passed to handle_inferior_event.
The stop func is only filled in later in the flow. And since "Remove
dead sets/clears of ecs->random signal", nothing ever sets
ecs->random_signal before this part is reached either.
(Also tested with some added assertions in place.)
gdb/
2013-10-28 Pedro Alves <palves@redhat.com>
* infrun.c (clear_stop_func): Delete.
(handle_inferior_event): Don't call clear_stop_func and don't
clear 'ecs->random_signal'.
The other day while debugging something related to random signals, I
got confused with "set debug infrun 1" output, for it said:
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4e8b94
infrun: random signal 20
On GNU/Linux, 20 is SIGTSTP. For some reason, it took me a few
minutes to realize that 20 is actually a GDB signal number, not a
target signal number (duh!). In any case, I propose making GDB's
output clearer here:
One way would be to use gdb_signal_to_name, like already used
elsewhere:
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4e8b94
infrun: random signal SIGCHLD (20)
but I think that might confuse someone too ("20? Why does GDB believe
SIGCHLD is 20?"). So I thought of printing the enum string instead:
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4e8b94
infrun: random signal GDB_SIGNAL_CHLD (20)
Looking at a more complete infrun debug log, we had actually printed
the (POSIX) signal name name a bit before:
infrun: target_wait (-1, status) =
infrun: 9300 [Thread 0x7ffff7fcb740 (LWP 9300)],
infrun: status->kind = stopped, signal = SIGCHLD
...
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4e8b94
infrun: random signal 20
So I'm now thinking that it'd be even better to make infrun output
consistently use the enum symbol string, like so:
infrun: clear_proceed_status_thread (Thread 0x7ffff7fca700 (LWP 25663))
infrun: clear_proceed_status_thread (Thread 0x7ffff7fcb740 (LWP 25659))
- infrun: proceed (addr=0xffffffffffffffff, signal=144, step=1)
+ infrun: proceed (addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT, step=1)
- infrun: resume (step=1, signal=0), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
+ infrun: resume (step=1, signal=GDB_SIGNAL_0), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
infrun: wait_for_inferior ()
infrun: target_wait (-1, status) =
infrun: 25659 [Thread 0x7ffff7fcb740 (LWP 25659)],
- infrun: status->kind = stopped, signal = SIGCHLD
+ infrun: status->kind = stopped, signal = GDB_SIGNAL_CHLD
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x400700
- infrun: random signal 20
+ infrun: random signal (GDB_SIGNAL_CHLD)
infrun: random signal, keep going
- infrun: resume (step=1, signal=20), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
+ infrun: resume (step=1, signal=GDB_SIGNAL_CHLD), trap_expected=0, current thread [Thread 0x7ffff7fcb740 (LWP 25659)] at 0x400700
infrun: prepare_to_wait
infrun: target_wait (-1, status) =
infrun: 25659 [Thread 0x7ffff7fcb740 (LWP 25659)],
- infrun: status->kind = stopped, signal = SIGTRAP
+ infrun: status->kind = stopped, signal = GDB_SIGNAL_TRAP
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x400704
infrun: stepi/nexti
infrun: stop_stepping
GDB's signal numbers are public and hardcoded (see
include/gdb/signals.h), so there's really no need to clutter the
output with numeric values in some places while others not. Replacing
the magic "144" with GDB_SIGNAL_DEFAULT in "proceed"'s debug output
(see above) I think is quite nice.
I posit that all this makes it clearer to newcomers that GDB has its
own signal numbering (and that there must be some mapping going on).
Tested on x86_64 Fedora 17.
gdb/
2013-10-23 Pedro Alves <palves@redhat.com>
* common/gdb_signals.h (gdb_signal_to_symbol_string): Declare.
* common/signals.c: Include "gdb_assert.h".
(signals): New field 'symbol'.
(SET): Use the 'symbol' parameter.
(gdb_signal_to_symbol_string): New function.
* infrun.c (handle_inferior_event) <random signal>: In debug
output, print the random signal enum as string in addition to its
number.
* target/waitstatus.c (target_waitstatus_to_string): Print the
signal's enum value as string instead of the (POSIX) signal name.
'*ecs' is always memset by handle_inferior_event's callers, so all
these clears are unnecessary. There's one place that sets the flag to
true, but, afterwards, before ecs->random_signal is ever read, we
reach the part of handle_inferior_even that clears ecs->random_signal,
among other things:
clear_stop_func (ecs);
ecs->event_thread->stepping_over_breakpoint = 0;
bpstat_clear (&ecs->event_thread->control.stop_bpstat);
ecs->event_thread->control.stop_step = 0;
stop_print_frame = 1;
ecs->random_signal = 0;
stopped_by_random_signal = 0;
So all these ecs->random_signal accesses are dead code.
Tested on x86_64 Fedora 17.
gdb/
2013-10-22 Pedro Alves <palves@redhat.com>
* infrun.c (handle_inferior_event) <thread hop>: Don't clear or
set ecs->random signal.
This function still has comments referring back to when it was a goto
label in wait_for_inferior, eons ago. Looking closer, actually most
of its comments could use a facelift (contents/formatting/typos).
That's what this patch does.
gdb/
2013-10-22 Pedro Alves <palves@redhat.com>
* infrun.c (keep_going): Update comments.
I noticed something odd while doing "stepi" over a fork syscall:
...
(gdb) set disassemble-next-line on
...
(gdb) si
0x000000323d4ba7c2 131 pid = ARCH_FORK ();
0x000000323d4ba7a4 <__libc_fork+132>: 64 4c 8b 04 25 10 00 00 00 mov %fs:0x10,%r8
0x000000323d4ba7ad <__libc_fork+141>: 31 d2 xor %edx,%edx
0x000000323d4ba7af <__libc_fork+143>: 4d 8d 90 d0 02 00 00 lea 0x2d0(%r8),%r10
0x000000323d4ba7b6 <__libc_fork+150>: 31 f6 xor %esi,%esi
0x000000323d4ba7b8 <__libc_fork+152>: bf 11 00 20 01 mov $0x1200011,%edi
0x000000323d4ba7bd <__libc_fork+157>: b8 38 00 00 00 mov $0x38,%eax
=> 0x000000323d4ba7c2 <__libc_fork+162>: 0f 05 syscall
0x000000323d4ba7c4 <__libc_fork+164>: 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax
0x000000323d4ba7ca <__libc_fork+170>: 0f 87 2b 01 00 00 ja 0x323d4ba8fb <__libc_fork+475>
(gdb) si
0x000000323d4ba7c4 131 pid = ARCH_FORK ();
0x000000323d4ba7a4 <__libc_fork+132>: 64 4c 8b 04 25 10 00 00 00 mov %fs:0x10,%r8
0x000000323d4ba7ad <__libc_fork+141>: 31 d2 xor %edx,%edx
0x000000323d4ba7af <__libc_fork+143>: 4d 8d 90 d0 02 00 00 lea 0x2d0(%r8),%r10
0x000000323d4ba7b6 <__libc_fork+150>: 31 f6 xor %esi,%esi
0x000000323d4ba7b8 <__libc_fork+152>: bf 11 00 20 01 mov $0x1200011,%edi
0x000000323d4ba7bd <__libc_fork+157>: b8 38 00 00 00 mov $0x38,%eax
0x000000323d4ba7c2 <__libc_fork+162>: 0f 05 syscall
=> 0x000000323d4ba7c4 <__libc_fork+164>: 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax
0x000000323d4ba7ca <__libc_fork+170>: 0f 87 2b 01 00 00 ja 0x323d4ba8fb <__libc_fork+475>
(gdb) si
0x000000323d4ba7c4 131 pid = ARCH_FORK ();
0x000000323d4ba7a4 <__libc_fork+132>: 64 4c 8b 04 25 10 00 00 00 mov %fs:0x10,%r8
0x000000323d4ba7ad <__libc_fork+141>: 31 d2 xor %edx,%edx
0x000000323d4ba7af <__libc_fork+143>: 4d 8d 90 d0 02 00 00 lea 0x2d0(%r8),%r10
0x000000323d4ba7b6 <__libc_fork+150>: 31 f6 xor %esi,%esi
0x000000323d4ba7b8 <__libc_fork+152>: bf 11 00 20 01 mov $0x1200011,%edi
0x000000323d4ba7bd <__libc_fork+157>: b8 38 00 00 00 mov $0x38,%eax
0x000000323d4ba7c2 <__libc_fork+162>: 0f 05 syscall
=> 0x000000323d4ba7c4 <__libc_fork+164>: 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax
0x000000323d4ba7ca <__libc_fork+170>: 0f 87 2b 01 00 00 ja 0x323d4ba8fb <__libc_fork+475>
(gdb) si
0x000000323d4ba7ca 131 pid = ARCH_FORK ();
0x000000323d4ba7a4 <__libc_fork+132>: 64 4c 8b 04 25 10 00 00 00 mov %fs:0x10,%r8
0x000000323d4ba7ad <__libc_fork+141>: 31 d2 xor %edx,%edx
0x000000323d4ba7af <__libc_fork+143>: 4d 8d 90 d0 02 00 00 lea 0x2d0(%r8),%r10
0x000000323d4ba7b6 <__libc_fork+150>: 31 f6 xor %esi,%esi
0x000000323d4ba7b8 <__libc_fork+152>: bf 11 00 20 01 mov $0x1200011,%edi
0x000000323d4ba7bd <__libc_fork+157>: b8 38 00 00 00 mov $0x38,%eax
0x000000323d4ba7c2 <__libc_fork+162>: 0f 05 syscall
0x000000323d4ba7c4 <__libc_fork+164>: 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax
=> 0x000000323d4ba7ca <__libc_fork+170>: 0f 87 2b 01 00 00 ja 0x323d4ba8fb <__libc_fork+475>
Notice how the third "si" didn't actually make progress.
Turning on infrun and lin-lwp debug, we see:
(gdb)
infrun: clear_proceed_status_thread (process 5252)
infrun: proceed (addr=0xffffffffffffffff, signal=144, step=1)
infrun: resume (step=1, signal=0), trap_expected=0, current thread [process 5252] at 0x323d4ba7c4
LLR: Preparing to step process 5252, 0, inferior_ptid process 5252
RC: Not resuming sibling process 5252 (not stopped)
LLR: PTRACE_SINGLESTEP process 5252, 0 (resume event thread)
sigchld
infrun: wait_for_inferior ()
linux_nat_wait: [process -1], []
LLW: enter
LNW: waitpid(-1, ...) returned 5252, No child processes
LLW: waitpid 5252 received Child exited (stopped)
LLW: Candidate event Child exited (stopped) in process 5252.
SEL: Select single-step process 5252
LLW: exit
infrun: target_wait (-1, status) =
infrun: 5252 [process 5252],
infrun: status->kind = stopped, signal = SIGCHLD
infrun: infwait_normal_state
infrun: TARGET_WAITKIND_STOPPED
infrun: stop_pc = 0x323d4ba7c4
infrun: random signal 20
infrun: stepi/nexti
infrun: stop_stepping
So the inferior got a SIGCHLD (because the fork child exited while
we're doing 'si'), and since that signal is set to "nostop noprint
pass" (by default), it's considered a random signal, so it should not
cause a stop. But, it resulted in an immediate a stop_stepping call
anyway. So the single-step never really finished.
This is a regression caused by:
[[PATCH] Do not respawn signals, take 2.]
https://sourceware.org/ml/gdb-patches/2012-06/msg00702.html
Specifically, caused by this change (as mentioned in the "the lost
step issue first" part of that mail):
diff --git a/gdb/infrun.c b/gdb/infrun.c
index 53db335..3e8dbc8 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -4363,10 +4363,8 @@ process_event_stop_test:
(leaving the inferior at the step-resume-breakpoint without
actually executing it). Either way continue until the
breakpoint is really hit. */
- keep_going (ecs);
- return;
}
-
+ else
/* Handle cases caused by hitting a breakpoint. */
{
That made GDB fall through to the
> /* In all-stop mode, if we're currently stepping but have stopped in
> some other thread, we need to switch back to the stepped thread. */
> if (!non_stop)
part. However, if we don't have a stepped thread to get back to,
we'll now also fall through to all the "stepping" tests. For line
stepping, that'll turn out okay, as we'll just end up realizing the
thread is still in the stepping range, and needs to be re-stepped.
However, for stepi/nexti, we'll reach:
if (ecs->event_thread->control.step_range_end == 1)
{
/* It is stepi or nexti. We always want to stop stepping after
one instruction. */
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: stepi/nexti\n");
ecs->event_thread->control.stop_step = 1;
print_end_stepping_range_reason ();
stop_stepping (ecs);
return;
}
and stop, even though the thread actually made no progress. The fix
is to restore the keep_going call, but put it after the "switch back
to the stepped thread" code, and before the stepping tests.
Tested on x86_64 Fedora 17, native and gdbserver. New test included.
gdb/
2013-10-18 Pedro Alves <palves@redhat.com>
PR gdb/16062
* infrun.c (handle_inferior_event): Keep going if we got a random
signal we should not stop for, instead of falling through to the
step tests.
gdb/testsuite/
2013-10-18 Pedro Alves <palves@redhat.com>
PR gdb/16062
* gdb.threads/stepi-random-signal.c: New file.
* gdb.threads/stepi-random-signal.exp: New file.
will hold the signal number when the inferior terminates due to the
uncaught signal.
I've made modifications on infrun.c:handle_inferior_event such that
$_exitcode gets cleared when the inferior signalled, and vice-versa.
This assumption was made because the variables are mutually
exclusive, i.e., when the inferior terminates because of an uncaught
signal it is not possible for it to return. I have also made modifications
such that when a corefile is loaded, $_exitsignal gets set to the uncaught
signal that "killed" the inferior, and $_exitcode is cleared.
The patch also adds a NEWS entry, documentation bits, and a testcase. The
documentation entry explains how to use $_exitsignal and $_exitcode in a
GDB script, by making use of the new $_isvoid convenience function.
gdb/
2013-10-06 Sergio Durigan Junior <sergiodj@redhat.com>
* NEWS: Mention new convenience variable $_exitsignal.
* corelow.c (core_open): Reset exit convenience variables. Set
$_exitsignal to the uncaught signal which generated the corefile.
* infrun.c (handle_inferior_event): Reset exit convenience
variables. Set $_exitsignal for TARGET_WAITKIND_SIGNALLED.
(clear_exit_convenience_vars): New function.
* inferior.h (clear_exit_convenience_vars): New prototype.
gdb/testsuite/
2013-10-06 Sergio Durigan Junior <sergiodj@redhat.com>
* gdb.base/corefile.exp: Test whether $_exitsignal is set and
$_exitcode is void when opening a corefile.
* gdb.base/exitsignal.exp: New file.
* gdb.base/segv.c: Likewise.
* gdb.base/normal.c: Likewise.
gdb/doc/
2013-10-06 Sergio Durigan Junior <sergiodj@redhat.com>
* gdb.texinfo (Convenience Variables): Document $_exitsignal.
Update entry for $_exitcode.
"info threads" changes the default source for "break" and "list", to
whatever the location of the first/bottom thread in the thread list
is...
(gdb) b start
(gdb) c
...
(gdb) list
*lists "start"*
(gdb) b 23
Breakpoint 3 at 0x400614: file test.c, line 23.
(gdb) info threads
Id Target Id Frame
* 2 Thread 0x7ffff7fcb700 (LWP 1760) "test" start (arg=0x0) at test.c:23
1 Thread 0x7ffff7fcc740 (LWP 1748) "test" 0x000000323dc08e60 in pthread_join (threadid=140737353922304, thread_return=0x0) at pthread_join.c:93
(gdb) b 23
Breakpoint 4 at 0x323dc08d90: file pthread_join.c, line 23.
^^^^^^^^^^^^^^^
(gdb) list
93 lll_wait_tid (pd->tid);
94
95
96 /* Restore cancellation mode. */
97 CANCEL_RESET (oldtype);
98
99 /* Remove the handler. */
100 pthread_cleanup_pop (0);
101
102
The issue is that print_stack_frame always sets the current sal to the
frame's sal. print_frame_info (which print_stack_frame calls to do
most of the work) also sets the last displayed sal, but only if
print_what isn't LOCATION. Now the call in question, from within
thread.c:print_thread_info, does pass in LOCATION as print_what, but
print_stack_frame doesn't have the same check print_frame_info has.
We could consider adding it, but setting these globals depending on
print_what isn't very clean, IMO. What we have is two logically
distinct operations mixed in the same function(s):
#1 - print frame, in the format specified by {print_what,
print_level and print_args}.
#2 - We're displaying a frame to the user, and I want the default
sal to point here, because the program stopped here, or the user
did some context-changing command (up, down, etc.).
So I added a new parameter to print_stack_frame & friends for point
#2, and went through all calls in the tree adjusting as necessary.
Tested on x86_64 Fedora 17.
gdb/
2013-09-17 Pedro Alves <palves@redhat.com>
PR gdb/15911
* ada-tasks.c (task_command_1): Adjust call to print_stack_frame.
* bsd-kvm.c (bsd_kvm_open, bsd_kvm_proc_cmd, bsd_kvm_pcb_cmd):
* corelow.c (core_open):
* frame.h (print_stack_frame, print_frame_info): New
'set_current_sal' parameter.
* infcmd.c (finish_command, kill_command): Adjust call to
print_stack_frame.
* inferior.c (inferior_command): Likewise.
* infrun.c (normal_stop): Likewise.
* linux-fork.c (linux_fork_context): Likewise.
* record-full.c (record_full_goto_entry, record_full_restore):
Likewise.
* remote-mips.c (common_open): Likewise.
* stack.c (print_stack_frame): New 'set_current_sal' parameter.
Use it.
(print_frame_info): New 'set_current_sal' parameter. Set the last
displayed sal depending on the new paremeter instead of looking at
print_what.
(backtrace_command_1, select_and_print_frame, frame_command)
(current_frame_command, up_command, down_command): Adjust call to
print_stack_frame.
* thread.c (print_thread_info, restore_selected_frame)
(do_captured_thread_select): Adjust call to print_stack_frame.
* tracepoint.c (tfind_1): Likewise.
* mi/mi-cmd-stack.c (mi_cmd_stack_list_frames)
(mi_cmd_stack_info_frame): Likewise.
* mi/mi-interp.c (mi_on_normal_stop): Likewise.
* mi/mi-main.c (mi_cmd_exec_return, mi_cmd_trace_find): Likewise.
gdb/testsuite/
* gdb.threads/info-threads-cur-sal-2.c: New file.
* gdb.threads/info-threads-cur-sal.c: New file.
* gdb.threads/info-threads-cur-sal.exp: New file.
detach_fork.
* inf-ptrace.c (inf_ptrace_follow_fork): Likewise.
* inf-ttrace.c (inf_ttrace_follow_fork): Likewise.
* inferior.h (detach_fork): Remove.
* infrun.c (detach_fork): Adjust comment and make it
static.
(follow_fork): Pass detach_fork parameter to
target_follow_fork.
* linux-nat.c (linux_child_follow_fork): New parameter
detach_fork.
* target.c (target_follow_fork): New parameter detach_fork.
Pass detach_fork as parameter and print its value.
* target.h (struct target_ops) <to_follow_fork>: New int
parameter.
(target_follow_fork): New parameter detach_fork.
Declare it close to other related declarations in utils.h, and remove
local extern declaration hack.
gdb/
2013-06-28 Pedro Alves <palves@redhat.com>
* infrun.c (set_observer_mode): Don't declare pagination_enabled
here.
* utils.h (pagination_enabled): Declare.
The "non_stop_1" global is out of place, mixed with the observer bits.
This moves all the non-stop user-interface-related bits together.
gdb/
2013-06-28 Pedro Alves <palves@redhat.com>
* infrun.c (non_stop, non_stop_1, set_non_stop, show_non_stop):
Move higher up in file.
This whole comment is now a bit out of place. I looked into moving it
to handle_inferior_event, close to where in_solib_dynsym_resolve_code
is used, but then there are 3 such places. I then looked at
fragmenting it, pushing bits closer to the definitions of
in_solib_dynsym_resolve_code and gdbarch_skip_solib_resolver, but then
we'd lose the main advantage which is the overview. In the end, I
realized this can fit nicely as internals manual material.
This could possibly be a subsection of a new "run control", or "source
stepping" or "stepping" or some such a bit more general section, but
we can do that when we have more related content... Even the "single
stepping" section is presently empty...
gdb/doc/
2013-06-27 Pedro Alves <palves@redhat.com>
* gdbint.texinfo (Algorithms) <Stepping over runtime loader
dynamic symbol resolution code>: New section, based on infrun.c
comment.
gdb/
2013-06-27 Pedro Alves <palves@redhat.com>
* infrun.c: Remove comment describing the 'stepping over runtime
loader dynamic symbol resolution code' mechanism; moved to
gdbint.texinfo.
This hasn't been used for years.
gdb/
2013-06-26 Pedro Alves <palves@redhat.com>
* infrun.c (SOLIB_IN_DYNAMIC_LINKER): Delete macro and describing
comment.
This updates the comments on the step-over-resolver mechanism a bit,
adjusting it to refer to the gdbarch hooks instead of the old macros;
to mention the in_dynsym_resolve_code hook of the target_so_ops
vector; and to American English spelling (signalling->signaling).
gdb/
2013-06-26 Pedro Alves <palves@redhat.com>
* infrun.c: Update comments on stepping over runtime loader
dynamic symbol resolution code.
This fixes PR cli/15603.
The bug here is that when a software watchpoint is being used, gdb
will stop responding to C-c. This is a regression caused by the
"catch signal" patch.
The problem is that software watchpoints always end up on the bpstat
list. However, this makes bpstat_explains_signal return
BPSTAT_SIGNAL_HIDE, causing infrun to think that the signal is not a
"random signal".
The fix is to change bpstat_explains_signal to handle this better. I
chose to do it in a "clean API" way, by passing the signal value to
bpstat_explains_signal and then adding an explains_signal method for
watchpoints, which handles the specifics.
Built and regtested on x86-64 Fedora 18.
New test case included.
* break-catch-sig.c (signal_catchpoint_explains_signal): Add 'sig'
argument.
* breakpoint.c (bpstat_explains_signal): Add 'sig' argument.
Special case signals other than GDB_SIGNAL_TRAP.
(explains_signal_watchpoint): New function.
(base_breakpoint_explains_signal): Add 'sig' argument.
(initialize_breakpoint_ops): Set 'explains_signal' method for
watchpoints.
* breakpoint.h (struct breakpoint_ops) <explains_signal>: Add
signal argument.
(bpstat_explains_signal): Likewise.
* infrun.c (handle_syscall_event, handle_inferior_event): Update.
* gdb.base/random-signal.c: New file.
* gdb.base/random-signal.exp: New file.
* breakpoint.h (handle_solib_event): Moved function declaration
to solib.h.
* breakpoint.c (handle_solib_event): Moved function to solib.c.
(bpstat_stop_status): Pass new argument to handle_solib_event.
* solib.h (update_solib_breakpoints): New function declaration.
(handle_solib_event): Moved function declaration from
breakpoint.h.
* solib.c (update_solib_breakpoints): New function.
(handle_solib_event): Moved function from breakpoint.c.
Updated to call solib_ops->handle_event if not NULL.
* solist.h (target_so_ops): New fields "update_breakpoints" and
"handle_event".
* infrun.c (set_stop_on_solib_events): New function.
(_initialize_infrun): Use the above for "set
stop-on-solib-events".
(handle_inferior_event): Pass new argument to handle_solib_event.
* solib-svr4.c (probe.h): New include.
(svr4_free_library_list): New forward declaration.
(probe_action): New enum.
(probe_info): New struct.
(probe_info): New static variable.
(NUM_PROBES): New definition.
(svr4_info): New fields "using_xfer", "probes_table" and
"solib_list".
(free_probes_table): New function.
(free_solib_list): New function.
(svr4_pspace_data_cleanup): Free probes table and solib list.
(svr4_copy_library_list): New function.
(svr4_current_sos_via_xfer_libraries): New parameter "annex".
(svr4_read_so_list): New parameter "prev_lm".
(svr4_current_sos_direct): Renamed from "svr4_current_sos".
(svr4_current_sos): New function.
(probe_and_action): New struct.
(hash_probe_and_action): New function.
(equal_probe_and_action): Likewise.
(register_solib_event_probe): Likewise.
(solib_event_probe_at): Likewise.
(solib_event_probe_action): Likewise.
(solist_update_full): Likewise.
(solist_update_incremental): Likewise.
(disable_probes_interface_cleanup): Likewise.
(svr4_handle_solib_event): Likewise.
(svr4_update_solib_event_breakpoint): Likewise.
(svr4_update_solib_event_breakpoints): Likewise.
(svr4_create_solib_event_breakpoints): Likewise.
(enable_break): Free probes table before creating breakpoints.
Use svr4_create_solib_event_breakpoints to create breakpoints.
(svr4_solib_create_inferior_hook): Free the solib list.
(_initialize_svr4_solib): Initialise
svr4_so_ops.handle_solib_event and svr4_so_ops.update_breakpoints.
This fixes some of the problems in infrun.c that the checker reported.
I filed the remaining problems as bugs.
This patch is purely stylistic.
* infrun.c (adjust_pc_after_break): Introduce an outer null
cleanup.
This patch teaches GDB to take advantage of target-assisted range
stepping. It adds a new 'r ADDR1,ADDR2' action to vCont (vCont;r),
meaning, "step once, and keep stepping as long as the thread is in the
[ADDR1,ADDR2) range".
Rationale:
When user issues the "step" command on the following line of source,
a = b + c + d * e - a;
GDB single-steps every single instruction until the program reaches a
new different line. E.g., on x86_64, that line compiles to:
0x08048434 <+65>: mov 0x1c(%esp),%eax
0x08048438 <+69>: mov 0x30(%esp),%edx
0x0804843c <+73>: add %eax,%edx
0x0804843e <+75>: mov 0x18(%esp),%eax
0x08048442 <+79>: imul 0x2c(%esp),%eax
0x08048447 <+84>: add %edx,%eax
0x08048449 <+86>: sub 0x34(%esp),%eax
0x0804844d <+90>: mov %eax,0x34(%esp)
0x08048451 <+94>: mov 0x1c(%esp),%eax
and the following is the RSP traffic between GDB and GDBserver:
--> vCont;s:p2e13.2e13;c
<-- T0505:68efffbf;04:30efffbf;08:3c840408;thread:p2e13.2e13;core:1;
--> vCont;s:p2e13.2e13;c
<-- T0505:68efffbf;04:30efffbf;08:3e840408;thread:p2e13.2e13;core:2;
--> vCont;s:p2e13.2e13;c
<-- T0505:68efffbf;04:30efffbf;08:42840408;thread:p2e13.2e13;core:2;
--> vCont;s:p2e13.2e13;c
<-- T0505:68efffbf;04:30efffbf;08:47840408;thread:p2e13.2e13;core:0;
--> vCont;s:p2e13.2e13;c
<-- T0505:68efffbf;04:30efffbf;08:49840408;thread:p2e13.2e13;core:0;
--> vCont;s:p2e13.2e13;c
<-- T0505:68efffbf;04:30efffbf;08:4d840408;thread:p2e13.2e13;core:0;
--> vCont;s:p2e13.2e13;c
<-- T0505:68efffbf;04:30efffbf;08:51840408;thread:p2e13.2e13;core:0;
IOW, a lot of roundtrips between GDB and GDBserver.
If we add a new command to the RSP, meaning "keep stepping and don't
report a stop until the program goes out of the [0x08048434,
0x08048451) address range", then the RSP traffic can be reduced down
to:
--> vCont;r8048434,8048451:p2db0.2db0;c
<-- T0505:68efffbf;04:30efffbf;08:51840408;thread:p2db0.2db0;core:1;
As number of packets is reduced dramatically, the performance of
stepping source lines is much improved.
In case something is wrong with range stepping on the stub side, the
debug info or even gdb, this adds a "set/show range-stepping" command
to be able to turn range stepping off.
gdb/
2013-05-23 Yao Qi <yao@codesourcery.com>
Pedro Alves <palves@redhat.com>
* gdbthread.h (struct thread_control_state) <may_range_step>: New
field.
* infcmd.c (step_once, until_next_command): Enable range stepping.
* infrun.c (displaced_step_prepare): Disable range stepping.
(resume): Disable range stepping if stepping over a breakpoint or
we have software watchpoints. If range stepping is enabled,
assert the thread is in the stepping range.
(clear_proceed_status_thread): Clear may_range_step.
(handle_inferior_event): Disable range stepping as soon as we know
the thread that hit the event. Re-enable it whenever we're going
to step with a step range.
* remote.c (struct vCont_action_support) <r>: New field.
(use_range_stepping): New global.
(remote_vcont_probe): Handle 'r' action.
(append_resumption): Append an 'r' action if the thread may range
step.
(show_range_stepping): New function.
(set_range_stepping): New function.
(_initialize_remote): Call add_setshow_boolean_cmd to register the
'set range-stepping' and 'show range-stepping' commands.
* NEWS: Mention range stepping, the new vCont;r action, and the
new "set/show range-stepping" commands.
gdb/doc/
2013-05-23 Yao Qi <yao@codesourcery.com>
Pedro Alves <palves@redhat.com>
* gdb.texinfo (Packets): Document 'vCont;r'.
(Continuing and Stepping): Document target-assisted range
stepping, and the 'set range-stepping' and 'show range-stepping'
commands.
This adds a function for doing within-thread's-stepping-range checks,
and converts a couple spots to use it. Following patches will add
more uses.
gdb/
2013-05-23 Yao Qi <yao@codesourcery.com>
Pedro Alves <palves@redhat.com>
* gdbthread.h (pc_in_thread_step_range): New declaration.
* thread.c (pc_in_thread_step_range): New function.
* infrun.c (handle_inferior_event): Use it.
This is sort of a continuation of Keith's parse_exp_1 constification
patch. It started out by undoing these bits:
@@ -754,9 +754,12 @@ validate_actionline (char **line, struct
tmp_p = p;
for (loc = t->base.loc; loc; loc = loc->next)
{
- p = tmp_p;
- exp = parse_exp_1 (&p, loc->address,
+ const char *q;
+
+ q = tmp_p;
+ exp = parse_exp_1 (&q, loc->address,
block_for_pc (loc->address), 1);
+ p = (char *) q;
and progressively making more things const upwards, fixing fallout,
rinse repeat, until GDB built again (--enable-targets=all).
That ended up constifying lookup_cmd/add_cmd and (lots of) friends,
and the completers.
I didn't try to constify the command hooks themselves, because I know
upfront there are commands that write to the command string argument,
and I think I managed to stop at a nice non-hacky split point already.
I think the only non-really-super-obvious changes are
tracepoint.c:validate_actionline, and tracepoint.c:trace_dump_actions.
The rest is just mostly about 'char *' => 'const char *', 'char **'=>
'const char **', and the occasional (e.g., deprecated_cmd_warning)
case of 'char **'=> 'const char *', where/when I noticed that nothing
actually cares about the pointer to pointer output.
Tested on x86_64 Fedora 17, native and gdbserver.
gdb/
2013-03-13 Pedro Alves <palves@redhat.com>
* ada-lang.c (struct add_partial_datum) <text, text0, word>: Make
fields const.
(ada_make_symbol_completion_list): Make "text0" parameter const.
* ax-gdb.c (agent_eval_command_one): Make "exp" parameter const.
* breakpoint.c (condition_completer): Make "text" and "word"
parameters const. Adjust.
(check_tracepoint_command): Adjust to validate_actionline
prototype change.
(catch_syscall_completer): Make "text" and "word" parameters
const.
* cli/cli-cmds.c (show_user): Make "comname" local const.
(valid_command_p): Make "command" parameter const.
(alias_command): Make "alias_prefix" and "command_prefix" locals
const.
* cli/cli-decode.c (add_cmd): Make "name" parameter const.
(add_alias_cmd): Make "name" and "oldname" parameters const.
Adjust. No longer make copy of OLDNAME.
(add_prefix_cmd, add_abbrev_prefix_cmd, add_set_or_show_cmd)
(add_setshow_cmd_full, add_setshow_enum_cmd)
(add_setshow_auto_boolean_cmd, add_setshow_boolean_cmd)
(add_setshow_filename_cmd, add_setshow_string_cmd)
(add_setshow_string_noescape_cmd)
(add_setshow_optional_filename_cmd, add_setshow_integer_cmd)
(add_setshow_uinteger_cmd, add_setshow_zinteger_cmd)
(add_setshow_zuinteger_unlimited_cmd, add_setshow_zuinteger_cmd)
(delete_cmd, add_info, add_info_alias, add_com, add_com_alias):
Make "name" parameter const.
(help_cmd): Rename "command" parameter to "arg". New const local
"command".
(find_cmd): Make "command" parameter const.
(lookup_cmd_1): Make "text" parameter pointer to const. Adjust to
deprecated_cmd_warning prototype change.
(undef_cmd_error): Make "cmdtype" parameter const.
(lookup_cmd): Make "line" parameter const.
(deprecated_cmd_warning): Change type of "text" parameter to
pointer to const char, from pointer to pointer to char. Adjust.
(lookup_cmd_composition): Make "text" parameter const.
(complete_on_cmdlist, complete_on_enum): Make "text" and "word"
parameters const.
* cli/cli-decode.h (struct cmd_list_element) <name>: Make field
const.
* cli/cli-script.c (validate_comname): Make "tem" local const.
(define_command): New const local "tem_c". Use it in calls to
lookup_cmd.
(document_command): Make "tem" and "comfull" locals const.
(show_user_1): Make "prefix" and "name" parameters const.
* cli-script.h (show_user_1): Make "prefix" and "name" parameters
const.
* command.h (add_cmd, add_alias_cmd, add_prefix_cmd)
(add_abbrev_prefix_cmd, completer_ftype, lookup_cmd, lookup_cmd_1)
(deprecated_cmd_warning, lookup_cmd_composition, add_com)
(add_com_alias, add_info, add_info_alias, complete_on_cmdlist)
(complete_on_enum, add_setshow_enum_cmd)
(add_setshow_auto_boolean_cmd, add_setshow_boolean_cmd)
(add_setshow_filename_cmd, add_setshow_string_cmd)
(add_setshow_string_noescape_cmd)
(add_setshow_optional_filename_cmd, add_setshow_integer_cmd)
(add_setshow_uinteger_cmd, add_setshow_zinteger_cmd)
(add_setshow_zuinteger_cmd, add_setshow_zuinteger_unlimited_cmd):
Change prototypes, constifying strings.
* completer.c (noop_completer, filename_completer): Make "text"
and "prefix" parameters const.
(location_completer, expression_completer)
(complete_line_internal): Make "text" and "prefix" parameters
const and adjust.
(command_completer, signal_completer): Make "text" and "prefix"
parameters const.
* completer.h (noop_completer, filename_completer)
(expression_completer, location_completer, command_completer)
(signal_completer): Change prototypes.
* corefile.c (complete_set_gnutarget): Make "text" and "word"
parameters const.
* cp-abi.c (cp_abi_completer): Likewise.
* expression.h (parse_expression_for_completion): Change
prototype.
* f-lang.c (f_make_symbol_completion_list): Make "text" and "word"
parameters const.
* infcmd.c (_initialize_infcmd): Make "cmd_name" local const.
* infrun.c (handle_completer): Make "text" and "word" parameters
const.
* interps.c (interpreter_completer): Make "text" and "word"
parameters const.
* language.h (struct language_defn)
<la_make_symbol_completion_list>: Make "text" and "word"
parameters const.
* parse.c (parse_exp_1): Move const hack to parse_exp_in_context.
(parse_exp_in_context): Rename to ...
(parse_exp_in_context_1): ... this.
(parse_exp_in_context): Reimplement, with const hack from
parse_exp_1.
(parse_expression_for_completion): Make "string" parameter const.
* printcmd.c (decode_format): Make "string_ptr" parameter pointer
to pointer to const char. Adjust.
(print_command_1): Make "exp" parameter const.
(output_command): Rename to ...
(output_command_const): ... this. Make "exp" parameter const.
(output_command): Reimplement.
(x_command): Adjust.
(display_command): Rename "exp" parameter to "arg". New "exp"
local, const version of "arg".
* python/py-auto-load.c (gdbpy_initialize_auto_load): Make
"cmd_name" local const.
* python/py-cmd.c (cmdpy_destroyer): Cast const away in xfree
call.
(cmdpy_completer): Make "text" and "word" parameters const.
(gdbpy_parse_command_name): Make "prefix_text2" local const.
* python/py-param.c (add_setshow_generic): Make "tmp_name" local
const.
* remote.c (_initialize_remote): Make "cmd_name" local const.
* symtab.c (language_search_unquoted_string): Make "text" and "p"
parameters const. Adjust.
(completion_list_add_fields): Make "sym_text", "text" and "word"
parameters const.
(struct add_name_data) <sym_text, text, word>: Make fields const.
(default_make_symbol_completion_list_break_on): Make "text" and
"word" parameters const. Adjust locals.
(default_make_symbol_completion_list)
(make_symbol_completion_list, make_symbol_completion_type)
(make_symbol_completion_list_fn): Make "text" and "word"
parameters const.
(make_file_symbol_completion_list): Make "text", "word" and
"srcfile" parameters const. Adjust locals.
(add_filename_to_list): Make "text" and "word" parameters const.
(struct add_partial_filename_data) <text, word>: Make fields
const.
(make_source_files_completion_list): Make "text" and "word"
parameters const.
* symtab.h (default_make_symbol_completion_list_break_on)
(default_make_symbol_completion_list, make_symbol_completion_list)
(make_symbol_completion_type enum type_code)
(make_symbol_completion_list_fn make_file_symbol_completion_list)
(make_source_files_completion_list): Change prototype.
* top.c (execute_command): Adjust to pass pointer to pointer to
const char to lookup_cmd, and to deprecated_cmd_warning prototype
change.
(set_verbose): Make "cmdname" local const.
* tracepoint.c (decode_agent_options): Make "exp" parameter const,
and adjust.
(validate_actionline): Make "line" parameter a pointer to const
char, and adjust.
(encode_actions_1): Make "action_exp" local const, and adjust.
(encode_actions): Adjust.
(replace_comma): Delete.
(trace_dump_actions): Make "action_exp" and "next_comma" locals
const, and adjust. Don't frob the action string while splitting
it at commas. Instead, make a copy of each split substring in
turn.
(trace_dump_command): Adjust to validate_actionline prototype
change.
* tracepoint.h (decode_agent_options, decode_agent_options)
(encode_actions, validate_actionline): Change prototypes.
* valprint.h (output_command): Delete declaration.
(output_command_const): Declare.
* value.c (function_destroyer): Cast const away in xfree call.
gdb/
* record-full.h, record-full.c (record_memory_query): Rename
to ...
(record_full_memory_query): ...this. Update all users.
(record_arch_list_add_reg): Rename to ...
(record_full_arch_list_add_reg): ...this. Update all users.
(record_arch_list_add_mem): Rename to ...
(record_full_arch_list_add_mem): ...this. Update all users.
(record_arch_list_add_end): Rename to ...
(record_full_arch_list_add_end): ...this. Update all users.
(record_gdb_operation_disable_set): Rename to ...
(record_full_gdb_operation_disable_set): ...this.
Update all users.
Two modifications:
1. The addition of 2013 to the copyright year range for every file;
2. The use of a single year range, instead of potentially multiple
year ranges, as approved by the FSF.
* breakpoint.c (breakpoint_re_set): Remove the skip_re_set call.
* infrun.c (handle_inferior_event): Rename the called function to
function_name_is_marked_for_skip, pass it TMP_SAL.
* skip.c (struct skiplist_entry): Update function_name comment. Remove
fields pc, gdbarch and pending.
(skip_function_pc): Rename this forward declaration to ...
(skip_function): ... here.
(skip_file_command): Remove variable pending and its use, remove
initialization of E fields pending and gdbarch. Do not use SYMTAB
filename, use the specified one.
(skip_function_command): Remove variable func_pc, do not set it.
Update the caller of skip_function. Replace decode_line_1 call by
a lookup_symbol call. Remove variables orig_arg, decode_exception and
sals. Update the caller of skip_function.
(skip_info): Remove variable address_width and its use. Do not print
address (PC). Renumber column 5 to 4.
(skip_function_pc): Rename to ...
(skip_function): ... here and remove its parameters pc, arch and
pending. Update the function comment and no longer use those
parameters.
(function_pc_is_marked_for_skip): Rename to ...
(function_name_is_marked_for_skip): ... here, update function comment
just to a skip.h reference, replace pc parameter by function_name and
function_sal. No longer use E field pending and pc. Remove variables
searched_for_sal, sal and filename. Call compare_filenames_for_search
instead of just strcmp.
(skip_re_set): Remove the function.
* skip.h (struct symtab_and_line): New declaration.
(function_pc_is_marked_for_skip): Rename to ...
(function_name_is_marked_for_skip): ... here, replace pc parameter by
function_name and function_sal, update the function comment.
gdb/testsuite/
* gdb.base/skip-solib.exp (info skip with pending file): Update the
expected output.
(info skip with pending file): Remove.
(ignoring function in solib, info skip for function multiply): Update
the expected output.
* gdb.base/skip.ex (skip (main), skip function baz, info skip)
(info skip (delete 1), info skip after disabling all)
(info skip after enabling all, info skip after disabling 4 2-3)
(info skip after enabling 2-3, info skip 2-3)
(info skip after deleting 2 3): Update the expected output.
* gdb.linespec/base/two/thefile.cc (n): New variable v, split the
statement to its initialization and return.
* gdb.linespec/skip-two.exp: New file.
2012-11-30 Yao Qi <yao@codesourcery.com>
* infrun.c (error_is_running, ensure_not_running): Move them
to ...
* infcmd.c (error_is_running, ensure_not_running): ... here.
Make them 'static'.
* inferior.h: Remove declarations of error_is_running and
ensure_not_running.
2012-11-05 Pedro Alves <palves@redhat.com>
* inferior.c (exit_inferior_1): Clear 'vfork_parent' in the vfork
child. Clear 'pending_detach'.
* infrun.c (handle_vfork_child_exec_or_exit): Clear
'pending_detach' in the vfork parent.
gdb/testsuite/
2012-11-05 Pedro Alves <palves@redhat.com>
* gdb.base/foll-vfork.exp (vfork_relations_in_info_inferiors): New
procedure.
(do_vfork_and_follow_child_tests_exec)
(do_vfork_and_follow_child_tests_exit): Call it.
2012-11-02 Pedro Alves <palves@redhat.com>
PR gdb/14766
* infrun.c (handle_inferior_event)
<TARGET_WAITKIND_EXITED/TARGET_WAITKIND_SIGNALLED>: Switch to
null_ptid before handling a vfork child exec or exit. Switch to
the event ptid afterwards.
gdb/testsuite/
2012-11-02 Pedro Alves <palves@redhat.com>
PR gdb/14766
* gdb.base/foll-vfork.exp (vfork_child_follow_to_exit): Remove
setup_kfail.
(tcatch_vfork_then_child_follow_exit): No longer expect "Couldn't
get registers".
Pedro Alves
Andreas Arnez
Yao Qi
Gary Benson
Don Breazeal
Tom Tromey
Luis Machado
Simon Marchi
Doug Evans
Hui Zhu
Ulrich Weigand
Markus Metzger
Joel Brobecker
Sergio Durigan Junior
Luis Machado
Markus Metzger
Gary Benson
Joel Brobecker
Aleksandar Ristovski
Jan Kratochvil