Each time a dll is loaded, update_solib_list is called.
This in turn calls deep down xfer_partial -> windows_xfer_shared_libraries,
which calls windows_xfer_shared_library for each loaded dll,
and pe_text_section_offset reads the dll for the text section offset.
Also if the data provided by xfer_partial is bigger than 4K,
then all of this is done for each 4K chunk (see target_read_alloc_1).
Caching of the text section offset improves the startup time of
an application with >300 dynamically loaded plugins from 2m10s to 10s.
And the shutdown time improves from 2m to 2s.
gdb/ChangeLog:
2020-01-23 Hannes Domani <ssbssa@yahoo.de>
* i386-cygwin-tdep.c (core_process_module_section): Update.
* windows-nat.c (struct lm_info_windows): Add text_offset.
(windows_xfer_shared_libraries): Update.
* windows-tdep.c (windows_xfer_shared_library):
Add text_offset_cached argument.
* windows-tdep.h (windows_xfer_shared_library): Update.
This commit adds multi-target support to GDB. What this means is that
with this commit, GDB can now be connected to different targets at the
same time. E.g., you can debug a live native process and a core dump
at the same time, connect to multiple gdbservers, etc.
Actually, the word "target" is overloaded in gdb. We already have a
target stack, with pushes several target_ops instances on top of one
another. We also have "info target" already, which means something
completely different to what this patch does.
So from here on, I'll be using the "target connections" term, to mean
an open process_stratum target, pushed on a target stack. This patch
makes gdb have multiple target stacks, and multiple process_stratum
targets open simultaneously. The user-visible changes / commands will
also use this terminology, but of course it's all open to debate.
User-interface-wise, not that much changes. The main difference is
that each inferior may have its own target connection.
A target connection (e.g., a target extended-remote connection) may
support debugging multiple processes, just as before.
Say you're debugging against gdbserver in extended-remote mode, and
you do "add-inferior" to prepare to spawn a new process, like:
(gdb) target extended-remote :9999
...
(gdb) start
...
(gdb) add-inferior
Added inferior 2
(gdb) inferior 2
[Switching to inferior 2 [<null>] (<noexec>)]
(gdb) file a.out
...
(gdb) start
...
At this point, you have two inferiors connected to the same gdbserver.
With this commit, GDB will maintain a target stack per inferior,
instead of a global target stack.
To preserve the behavior above, by default, "add-inferior" makes the
new inferior inherit a copy of the target stack of the current
inferior. Same across a fork - the child inherits a copy of the
target stack of the parent. While the target stacks are copied, the
targets themselves are not. Instead, target_ops is made a
refcounted_object, which means that target_ops instances are
refcounted, which each inferior counting for a reference.
What if you want to create an inferior and connect it to some _other_
target? For that, this commit introduces a new "add-inferior
-no-connection" option that makes the new inferior not share the
current inferior's target. So you could do:
(gdb) target extended-remote :9999
Remote debugging using :9999
...
(gdb) add-inferior -no-connection
[New inferior 2]
Added inferior 2
(gdb) inferior 2
[Switching to inferior 2 [<null>] (<noexec>)]
(gdb) info inferiors
Num Description Executable
1 process 18401 target:/home/pedro/tmp/main
* 2 <null>
(gdb) tar extended-remote :10000
Remote debugging using :10000
...
(gdb) info inferiors
Num Description Executable
1 process 18401 target:/home/pedro/tmp/main
* 2 process 18450 target:/home/pedro/tmp/main
(gdb)
A following patch will extended "info inferiors" to include a column
indicating which connection an inferior is bound to, along with a
couple other UI tweaks.
Other than that, debugging is the same as before. Users interact with
inferiors and threads as before. The only difference is that
inferiors may be bound to processes running in different machines.
That's pretty much all there is to it in terms of noticeable UI
changes.
On to implementation.
Since we can be connected to different systems at the same time, a
ptid_t is no longer a unique identifier. Instead a thread can be
identified by a pair of ptid_t and 'process_stratum_target *', the
later being the instance of the process_stratum target that owns the
process/thread. Note that process_stratum_target inherits from
target_ops, and all process_stratum targets inherit from
process_stratum_target. In earlier patches, many places in gdb were
converted to refer to threads by thread_info pointer instead of
ptid_t, but there are still places in gdb where we start with a
pid/tid and need to find the corresponding inferior or thread_info
objects. So you'll see in the patch many places adding a
process_stratum_target parameter to functions that used to take only a
ptid_t.
Since each inferior has its own target stack now, we can always find
the process_stratum target for an inferior. That is done via a
inf->process_target() convenience method.
Since each inferior has its own target stack, we need to handle the
"beneath" calls when servicing target calls. The solution I settled
with is just to make sure to switch the current inferior to the
inferior you want before making a target call. Not relying on global
context is just not feasible in current GDB. Fortunately, there
aren't that many places that need to do that, because generally most
code that calls target methods already has the current context
pointing to the right inferior/thread. Note, to emphasize -- there's
no method to "switch to this target stack". Instead, you switch the
current inferior, and that implicitly switches the target stack.
In some spots, we need to iterate over all inferiors so that we reach
all target stacks.
Native targets are still singletons. There's always only a single
instance of such targets.
Remote targets however, we'll have one instance per remote connection.
The exec target is still a singleton. There's only one instance. I
did not see the point of instanciating more than one exec_target
object.
After vfork, we need to make sure to push the exec target on the new
inferior. See exec_on_vfork.
For type safety, functions that need a {target, ptid} pair to identify
a thread, take a process_stratum_target pointer for target parameter
instead of target_ops *. Some shared code in gdb/nat/ also need to
gain a target pointer parameter. This poses an issue, since gdbserver
doesn't have process_stratum_target, only target_ops. To fix this,
this commit renames gdbserver's target_ops to process_stratum_target.
I think this makes sense. There's no concept of target stack in
gdbserver, and gdbserver's target_ops really implements a
process_stratum-like target.
The thread and inferior iterator functions also gain
process_stratum_target parameters. These are used to be able to
iterate over threads and inferiors of a given target. Following usual
conventions, if the target pointer is null, then we iterate over
threads and inferiors of all targets.
I tried converting "add-inferior" to the gdb::option framework, as a
preparatory patch, but that stumbled on the fact that gdb::option does
not support file options yet, for "add-inferior -exec". I have a WIP
patchset that adds that, but it's not a trivial patch, mainly due to
need to integrate readline's filename completion, so I deferred that
to some other time.
In infrun.c/infcmd.c, the main change is that we need to poll events
out of all targets. See do_target_wait. Right after collecting an
event, we switch the current inferior to an inferior bound to the
target that reported the event, so that target methods can be used
while handling the event. This makes most of the code transparent to
multi-targets. See fetch_inferior_event.
infrun.c:stop_all_threads is interesting -- in this function we need
to stop all threads of all targets. What the function does is send an
asynchronous stop request to all threads, and then synchronously waits
for events, with target_wait, rinse repeat, until all it finds are
stopped threads. Now that we have multiple targets, it's not
efficient to synchronously block in target_wait waiting for events out
of one target. Instead, we implement a mini event loop, with
interruptible_select, select'ing on one file descriptor per target.
For this to work, we need to be able to ask the target for a waitable
file descriptor. Such file descriptors already exist, they are the
descriptors registered in the main event loop with add_file_handler,
inside the target_async implementations. This commit adds a new
target_async_wait_fd target method that just returns the file
descriptor in question. See wait_one / stop_all_threads in infrun.c.
The 'threads_executing' global is made a per-target variable. Since
it is only relevant to process_stratum_target targets, this is where
it is put, instead of in target_ops.
You'll notice that remote.c includes some FIXME notes. These refer to
the fact that the global arrays that hold data for the remote packets
supported are still globals. For example, if we connect to two
different servers/stubs, then each might support different remote
protocol features. They might even be different architectures, like
e.g., one ARM baremetal stub, and a x86 gdbserver, to debug a
host/controller scenario as a single program. That isn't going to
work correctly today, because of said globals. I'm leaving fixing
that for another pass, since it does not appear to be trivial, and I'd
rather land the base work first. It's already useful to be able to
debug multiple instances of the same server (e.g., a distributed
cluster, where you have full control over the servers installed), so I
think as is it's already reasonable incremental progress.
Current limitations:
- You can only resume more that one target at the same time if all
targets support asynchronous debugging, and support non-stop mode.
It should be possible to support mixed all-stop + non-stop
backends, but that is left for another time. This means that
currently in order to do multi-target with gdbserver you need to
issue "maint set target-non-stop on". I would like to make that
mode be the default, but we're not there yet. Note that I'm
talking about how the target backend works, only. User-visible
all-stop mode works just fine.
- As explained above, connecting to different remote servers at the
same time is likely to produce bad results if they don't support the
exact set of RSP features.
FreeBSD updates courtesy of John Baldwin.
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
John Baldwin <jhb@FreeBSD.org>
* aarch64-linux-nat.c
(aarch64_linux_nat_target::thread_architecture): Adjust.
* ada-tasks.c (print_ada_task_info): Adjust find_thread_ptid call.
(task_command_1): Likewise.
* aix-thread.c (sync_threadlists, aix_thread_target::resume)
(aix_thread_target::wait, aix_thread_target::fetch_registers)
(aix_thread_target::store_registers)
(aix_thread_target::thread_alive): Adjust.
* amd64-fbsd-tdep.c: Include "inferior.h".
(amd64fbsd_get_thread_local_address): Pass down target.
* amd64-linux-nat.c (ps_get_thread_area): Use ps_prochandle
thread's gdbarch instead of target_gdbarch.
* break-catch-sig.c (signal_catchpoint_print_it): Adjust call to
get_last_target_status.
* break-catch-syscall.c (print_it_catch_syscall): Likewise.
* breakpoint.c (breakpoints_should_be_inserted_now): Consider all
inferiors.
(update_inserted_breakpoint_locations): Skip if inferiors with no
execution.
(update_global_location_list): When handling moribund locations,
find representative inferior for location's pspace, and use thread
count of its process_stratum target.
* bsd-kvm.c (bsd_kvm_target_open): Pass target down.
* bsd-uthread.c (bsd_uthread_target::wait): Use
as_process_stratum_target and adjust thread_change_ptid and
add_thread calls.
(bsd_uthread_target::update_thread_list): Use
as_process_stratum_target and adjust find_thread_ptid,
thread_change_ptid and add_thread calls.
* btrace.c (maint_btrace_packet_history_cmd): Adjust
find_thread_ptid call.
* corelow.c (add_to_thread_list): Adjust add_thread call.
(core_target_open): Adjust add_thread_silent and thread_count
calls.
(core_target::pid_to_str): Adjust find_inferior_ptid call.
* ctf.c (ctf_target_open): Adjust add_thread_silent call.
* event-top.c (async_disconnect): Pop targets from all inferiors.
* exec.c (add_target_sections): Push exec target on all inferiors
sharing the program space.
(remove_target_sections): Remove the exec target from all
inferiors sharing the program space.
(exec_on_vfork): New.
* exec.h (exec_on_vfork): Declare.
* fbsd-nat.c (fbsd_add_threads): Add fbsd_nat_target parameter.
Pass it down.
(fbsd_nat_target::update_thread_list): Adjust.
(fbsd_nat_target::resume): Adjust.
(fbsd_handle_debug_trap): Add fbsd_nat_target parameter. Pass it
down.
(fbsd_nat_target::wait, fbsd_nat_target::post_attach): Adjust.
* fbsd-tdep.c (fbsd_corefile_thread): Adjust
get_thread_arch_regcache call.
* fork-child.c (gdb_startup_inferior): Pass target down to
startup_inferior and set_executing.
* gdbthread.h (struct process_stratum_target): Forward declare.
(add_thread, add_thread_silent, add_thread_with_info)
(in_thread_list): Add process_stratum_target parameter.
(find_thread_ptid(inferior*, ptid_t)): New overload.
(find_thread_ptid, thread_change_ptid): Add process_stratum_target
parameter.
(all_threads()): Delete overload.
(all_threads, all_non_exited_threads): Add process_stratum_target
parameter.
(all_threads_safe): Use brace initialization.
(thread_count): Add process_stratum_target parameter.
(set_resumed, set_running, set_stop_requested, set_executing)
(threads_are_executing, finish_thread_state): Add
process_stratum_target parameter.
(switch_to_thread): Use is_current_thread.
* i386-fbsd-tdep.c: Include "inferior.h".
(i386fbsd_get_thread_local_address): Pass down target.
* i386-linux-nat.c (i386_linux_nat_target::low_resume): Adjust.
* inf-child.c (inf_child_target::maybe_unpush_target): Remove
have_inferiors check.
* inf-ptrace.c (inf_ptrace_target::create_inferior)
(inf_ptrace_target::attach): Adjust.
* infcall.c (run_inferior_call): Adjust.
* infcmd.c (run_command_1): Pass target to
scoped_finish_thread_state.
(proceed_thread_callback): Skip inferiors with no execution.
(continue_command): Rename 'all_threads' local to avoid hiding
'all_threads' function. Adjust get_last_target_status call.
(prepare_one_step): Adjust set_running call.
(signal_command): Use user_visible_resume_target. Compare thread
pointers instead of inferior_ptid.
(info_program_command): Adjust to pass down target.
(attach_command): Mark target's 'thread_executing' flag.
(stop_current_target_threads_ns): New, factored out from ...
(interrupt_target_1): ... this. Switch inferior before making
target calls.
* inferior-iter.h
(struct all_inferiors_iterator, struct all_inferiors_range)
(struct all_inferiors_safe_range)
(struct all_non_exited_inferiors_range): Filter on
process_stratum_target too. Remove explicit.
* inferior.c (inferior::inferior): Push dummy target on target
stack.
(find_inferior_pid, find_inferior_ptid, number_of_live_inferiors):
Add process_stratum_target parameter, and pass it down.
(have_live_inferiors): Adjust.
(switch_to_inferior_and_push_target): New.
(add_inferior_command, clone_inferior_command): Handle
"-no-connection" parameter. Use
switch_to_inferior_and_push_target.
(_initialize_inferior): Mention "-no-connection" option in
the help of "add-inferior" and "clone-inferior" commands.
* inferior.h: Include "process-stratum-target.h".
(interrupt_target_1): Use bool.
(struct inferior) <push_target, unpush_target, target_is_pushed,
find_target_beneath, top_target, process_target, target_at,
m_stack>: New.
(discard_all_inferiors): Delete.
(find_inferior_pid, find_inferior_ptid, number_of_live_inferiors)
(all_inferiors, all_non_exited_inferiors): Add
process_stratum_target parameter.
* infrun.c: Include "gdb_select.h" and <unordered_map>.
(target_last_proc_target): New global.
(follow_fork_inferior): Push target on new inferior. Pass target
to add_thread_silent. Call exec_on_vfork. Handle target's
reference count.
(follow_fork): Adjust get_last_target_status call. Also consider
target.
(follow_exec): Push target on new inferior.
(struct execution_control_state) <target>: New field.
(user_visible_resume_target): New.
(do_target_resume): Call target_async.
(resume_1): Set target's threads_executing flag. Consider resume
target.
(commit_resume_all_targets): New.
(proceed): Also consider resume target. Skip threads of inferiors
with no execution. Commit resumtion in all targets.
(start_remote): Pass current inferior to wait_for_inferior.
(infrun_thread_stop_requested): Consider target as well. Pass
thread_info pointer to clear_inline_frame_state instead of ptid.
(infrun_thread_thread_exit): Consider target as well.
(random_pending_event_thread): New inferior parameter. Use it.
(do_target_wait): Rename to ...
(do_target_wait_1): ... this. Add inferior parameter, and pass it
down.
(threads_are_resumed_pending_p, do_target_wait): New.
(prepare_for_detach): Adjust calls.
(wait_for_inferior): New inferior parameter. Handle it. Use
do_target_wait_1 instead of do_target_wait.
(fetch_inferior_event): Adjust. Switch to representative
inferior. Pass target down.
(set_last_target_status): Add process_stratum_target parameter.
Save target in global.
(get_last_target_status): Add process_stratum_target parameter and
handle it.
(nullify_last_target_wait_ptid): Clear 'target_last_proc_target'.
(context_switch): Check inferior_ptid == null_ptid before calling
inferior_thread().
(get_inferior_stop_soon): Pass down target.
(wait_one): Rename to ...
(poll_one_curr_target): ... this.
(struct wait_one_event): New.
(wait_one): New.
(stop_all_threads): Adjust.
(handle_no_resumed, handle_inferior_event): Adjust to consider the
event's target.
(switch_back_to_stepped_thread): Also consider target.
(print_stop_event): Update.
(normal_stop): Update. Also consider the resume target.
* infrun.h (wait_for_inferior): Remove declaration.
(user_visible_resume_target): New declaration.
(get_last_target_status, set_last_target_status): New
process_stratum_target parameter.
* inline-frame.c (clear_inline_frame_state(ptid_t)): Add
process_stratum_target parameter, and use it.
(clear_inline_frame_state (thread_info*)): New.
* inline-frame.c (clear_inline_frame_state(ptid_t)): Add
process_stratum_target parameter.
(clear_inline_frame_state (thread_info*)): Declare.
* linux-fork.c (delete_checkpoint_command): Pass target down to
find_thread_ptid.
(checkpoint_command): Adjust.
* linux-nat.c (linux_nat_target::follow_fork): Switch to thread
instead of just tweaking inferior_ptid.
(linux_nat_switch_fork): Pass target down to thread_change_ptid.
(exit_lwp): Pass target down to find_thread_ptid.
(attach_proc_task_lwp_callback): Pass target down to
add_thread/set_running/set_executing.
(linux_nat_target::attach): Pass target down to
thread_change_ptid.
(get_detach_signal): Pass target down to find_thread_ptid.
Consider last target status's target.
(linux_resume_one_lwp_throw, resume_lwp)
(linux_handle_syscall_trap, linux_handle_extended_wait, wait_lwp)
(stop_wait_callback, save_stop_reason, linux_nat_filter_event)
(linux_nat_wait_1, resume_stopped_resumed_lwps): Pass target down.
(linux_nat_target::async_wait_fd): New.
(linux_nat_stop_lwp, linux_nat_target::thread_address_space): Pass
target down.
* linux-nat.h (linux_nat_target::async_wait_fd): Declare.
* linux-tdep.c (get_thread_arch_regcache): Pass target down.
* linux-thread-db.c (struct thread_db_info::process_target): New
field.
(add_thread_db_info): Save target.
(get_thread_db_info): New process_stratum_target parameter. Also
match target.
(delete_thread_db_info): New process_stratum_target parameter.
Also match target.
(thread_from_lwp): Adjust to pass down target.
(thread_db_notice_clone): Pass down target.
(check_thread_db_callback): Pass down target.
(try_thread_db_load_1): Always push the thread_db target.
(try_thread_db_load, record_thread): Pass target down.
(thread_db_target::detach): Pass target down. Always unpush the
thread_db target.
(thread_db_target::wait, thread_db_target::mourn_inferior): Pass
target down. Always unpush the thread_db target.
(find_new_threads_callback, thread_db_find_new_threads_2)
(thread_db_target::update_thread_list): Pass target down.
(thread_db_target::pid_to_str): Pass current inferior down.
(thread_db_target::get_thread_local_address): Pass target down.
(thread_db_target::resume, maintenance_check_libthread_db): Pass
target down.
* nto-procfs.c (nto_procfs_target::update_thread_list): Adjust.
* procfs.c (procfs_target::procfs_init_inferior): Declare.
(proc_set_current_signal, do_attach, procfs_target::wait): Adjust.
(procfs_init_inferior): Rename to ...
(procfs_target::procfs_init_inferior): ... this and adjust.
(procfs_target::create_inferior, procfs_notice_thread)
(procfs_do_thread_registers): Adjust.
* ppc-fbsd-tdep.c: Include "inferior.h".
(ppcfbsd_get_thread_local_address): Pass down target.
* proc-service.c (ps_xfer_memory): Switch current inferior and
program space as well.
(get_ps_regcache): Pass target down.
* process-stratum-target.c
(process_stratum_target::thread_address_space)
(process_stratum_target::thread_architecture): Pass target down.
* process-stratum-target.h
(process_stratum_target::threads_executing): New field.
(as_process_stratum_target): New.
* ravenscar-thread.c
(ravenscar_thread_target::update_inferior_ptid): Pass target down.
(ravenscar_thread_target::wait, ravenscar_add_thread): Pass target
down.
* record-btrace.c (record_btrace_target::info_record): Adjust.
(record_btrace_target::record_method)
(record_btrace_target::record_is_replaying)
(record_btrace_target::fetch_registers)
(get_thread_current_frame_id, record_btrace_target::resume)
(record_btrace_target::wait, record_btrace_target::stop): Pass
target down.
* record-full.c (record_full_wait_1): Switch to event thread.
Pass target down.
* regcache.c (regcache::regcache)
(get_thread_arch_aspace_regcache, get_thread_arch_regcache): Add
process_stratum_target parameter and handle it.
(current_thread_target): New global.
(get_thread_regcache): Add process_stratum_target parameter and
handle it. Switch inferior before calling target method.
(get_thread_regcache): Pass target down.
(get_thread_regcache_for_ptid): Pass target down.
(registers_changed_ptid): Add process_stratum_target parameter and
handle it.
(registers_changed_thread, registers_changed): Pass target down.
(test_get_thread_arch_aspace_regcache): New.
(current_regcache_test): Define a couple local test_target_ops
instances and use them for testing.
(readwrite_regcache): Pass process_stratum_target parameter.
(cooked_read_test, cooked_write_test): Pass mock_target down.
* regcache.h (get_thread_regcache, get_thread_arch_regcache)
(get_thread_arch_aspace_regcache): Add process_stratum_target
parameter.
(regcache::target): New method.
(regcache::regcache, regcache::get_thread_arch_aspace_regcache)
(regcache::registers_changed_ptid): Add process_stratum_target
parameter.
(regcache::m_target): New field.
(registers_changed_ptid): Add process_stratum_target parameter.
* remote.c (remote_state::supports_vCont_probed): New field.
(remote_target::async_wait_fd): New method.
(remote_unpush_and_throw): Add remote_target parameter.
(get_current_remote_target): Adjust.
(remote_target::remote_add_inferior): Push target.
(remote_target::remote_add_thread)
(remote_target::remote_notice_new_inferior)
(get_remote_thread_info): Pass target down.
(remote_target::update_thread_list): Skip threads of inferiors
bound to other targets. (remote_target::close): Don't discard
inferiors. (remote_target::add_current_inferior_and_thread)
(remote_target::process_initial_stop_replies)
(remote_target::start_remote)
(remote_target::remote_serial_quit_handler): Pass down target.
(remote_target::remote_unpush_target): New remote_target
parameter. Unpush the target from all inferiors.
(remote_target::remote_unpush_and_throw): New remote_target
parameter. Pass it down.
(remote_target::open_1): Check whether the current inferior has
execution instead of checking whether any inferior is live. Pass
target down.
(remote_target::remote_detach_1): Pass down target. Use
remote_unpush_target.
(extended_remote_target::attach): Pass down target.
(remote_target::remote_vcont_probe): Set supports_vCont_probed.
(remote_target::append_resumption): Pass down target.
(remote_target::append_pending_thread_resumptions)
(remote_target::remote_resume_with_hc, remote_target::resume)
(remote_target::commit_resume): Pass down target.
(remote_target::remote_stop_ns): Check supports_vCont_probed.
(remote_target::interrupt_query)
(remote_target::remove_new_fork_children)
(remote_target::check_pending_events_prevent_wildcard_vcont)
(remote_target::remote_parse_stop_reply)
(remote_target::process_stop_reply): Pass down target.
(first_remote_resumed_thread): New remote_target parameter. Pass
it down.
(remote_target::wait_as): Pass down target.
(unpush_and_perror): New remote_target parameter. Pass it down.
(remote_target::readchar, remote_target::remote_serial_write)
(remote_target::getpkt_or_notif_sane_1)
(remote_target::kill_new_fork_children, remote_target::kill): Pass
down target.
(remote_target::mourn_inferior): Pass down target. Use
remote_unpush_target.
(remote_target::core_of_thread)
(remote_target::remote_btrace_maybe_reopen): Pass down target.
(remote_target::pid_to_exec_file)
(remote_target::thread_handle_to_thread_info): Pass down target.
(remote_target::async_wait_fd): New.
* riscv-fbsd-tdep.c: Include "inferior.h".
(riscv_fbsd_get_thread_local_address): Pass down target.
* sol2-tdep.c (sol2_core_pid_to_str): Pass down target.
* sol-thread.c (sol_thread_target::wait, ps_lgetregs, ps_lsetregs)
(ps_lgetfpregs, ps_lsetfpregs, sol_update_thread_list_callback):
Adjust.
* solib-spu.c (spu_skip_standalone_loader): Pass down target.
* solib-svr4.c (enable_break): Pass down target.
* spu-multiarch.c (parse_spufs_run): Pass down target.
* spu-tdep.c (spu2ppu_sniffer): Pass down target.
* target-delegates.c: Regenerate.
* target.c (g_target_stack): Delete.
(current_top_target): Return the current inferior's top target.
(target_has_execution_1): Refer to the passed-in inferior's top
target.
(target_supports_terminal_ours): Check whether the initial
inferior was already created.
(decref_target): New.
(target_stack::push): Incref/decref the target.
(push_target, push_target, unpush_target): Adjust.
(target_stack::unpush): Defref target.
(target_is_pushed): Return bool. Adjust to refer to the current
inferior's target stack.
(dispose_inferior): Delete, and inline parts ...
(target_preopen): ... here. Only dispose of the current inferior.
(target_detach): Hold strong target reference while detaching.
Pass target down.
(target_thread_name): Add assertion.
(target_resume): Pass down target.
(target_ops::beneath, find_target_at): Adjust to refer to the
current inferior's target stack.
(get_dummy_target): New.
(target_pass_ctrlc): Pass the Ctrl-C to the first inferior that
has a thread running.
(initialize_targets): Rename to ...
(_initialize_target): ... this.
* target.h: Include "gdbsupport/refcounted-object.h".
(struct target_ops): Inherit refcounted_object.
(target_ops::shortname, target_ops::longname): Make const.
(target_ops::async_wait_fd): New method.
(decref_target): Declare.
(struct target_ops_ref_policy): New.
(target_ops_ref): New typedef.
(get_dummy_target): Declare function.
(target_is_pushed): Return bool.
* thread-iter.c (all_matching_threads_iterator::m_inf_matches)
(all_matching_threads_iterator::all_matching_threads_iterator):
Handle filter target.
* thread-iter.h (struct all_matching_threads_iterator, struct
all_matching_threads_range, class all_non_exited_threads_range):
Filter by target too. Remove explicit.
* thread.c (threads_executing): Delete.
(inferior_thread): Pass down current inferior.
(clear_thread_inferior_resources): Pass down thread pointer
instead of ptid_t.
(add_thread_silent, add_thread_with_info, add_thread): Add
process_stratum_target parameter. Use it for thread and inferior
searches.
(is_current_thread): New.
(thread_info::deletable): Use it.
(find_thread_ptid, thread_count, in_thread_list)
(thread_change_ptid, set_resumed, set_running): New
process_stratum_target parameter. Pass it down.
(set_executing): New process_stratum_target parameter. Pass it
down. Adjust reference to 'threads_executing'.
(threads_are_executing): New process_stratum_target parameter.
Adjust reference to 'threads_executing'.
(set_stop_requested, finish_thread_state): New
process_stratum_target parameter. Pass it down.
(switch_to_thread): Also match inferior.
(switch_to_thread): New process_stratum_target parameter. Pass it
down.
(update_threads_executing): Reimplement.
* top.c (quit_force): Pop targets from all inferior.
(gdb_init): Don't call initialize_targets.
* windows-nat.c (windows_nat_target) <get_windows_debug_event>:
Declare.
(windows_add_thread, windows_delete_thread): Adjust.
(get_windows_debug_event): Rename to ...
(windows_nat_target::get_windows_debug_event): ... this. Adjust.
* tracefile-tfile.c (tfile_target_open): Pass down target.
* gdbsupport/common-gdbthread.h (struct process_stratum_target):
Forward declare.
(switch_to_thread): Add process_stratum_target parameter.
* mi/mi-interp.c (mi_on_resume_1): Add process_stratum_target
parameter. Use it.
(mi_on_resume): Pass target down.
* nat/fork-inferior.c (startup_inferior): Add
process_stratum_target parameter. Pass it down.
* nat/fork-inferior.h (startup_inferior): Add
process_stratum_target parameter.
* python/py-threadevent.c (py_get_event_thread): Pass target down.
gdb/gdbserver/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* fork-child.c (post_fork_inferior): Pass target down to
startup_inferior.
* inferiors.c (switch_to_thread): Add process_stratum_target
parameter.
* lynx-low.c (lynx_target_ops): Now a process_stratum_target.
* nto-low.c (nto_target_ops): Now a process_stratum_target.
* linux-low.c (linux_target_ops): Now a process_stratum_target.
* remote-utils.c (prepare_resume_reply): Pass the target to
switch_to_thread.
* target.c (the_target): Now a process_stratum_target.
(done_accessing_memory): Pass the target to switch_to_thread.
(set_target_ops): Ajust to use process_stratum_target.
* target.h (struct target_ops): Rename to ...
(struct process_stratum_target): ... this.
(the_target, set_target_ops): Adjust.
(prepare_to_access_memory): Adjust comment.
* win32-low.c (child_xfer_memory): Adjust to use
process_stratum_target.
(win32_target_ops): Now a process_stratum_target.
When a Windows program is terminated by a fatal exception, its exit
code is the value of that exception, as defined by the various
EXCEPTION_* symbols in the Windows API headers. This commit emulates
WTERMSIG etc. by translating the fatal exception codes to more-or-less
equivalent Posix signals.
gdb/ChangeLog:
2020-01-06 Eli Zaretskii <eliz@gnu.org>
Pedro Alves <palves@redhat.com>
* Makefile.in (COMMON_SFILES): Add gdbsupport/gdb_wait.c.
* windows-tdep.c: New enumeration of WINDOWS_SIG* signals.
(windows_gdb_signal_to_target): New function, uses the above
enumeration to convert GDB internal signal codes to equivalent
Windows codes.
(windows_init_abi): Call set_gdbarch_gdb_signal_to_target.
* windows-nat.c: Include "gdb_wait.h".
(get_windows_debug_event): Extract the fatal exception from the
exit status and convert to the equivalent Posix signal number.
* cli/cli-cmds.c (exit_status_set_internal_vars): Account for the
possibility that WTERMSIG returns GDB_SIGNAL_UNKNOWN.
* gdbsupport/gdb_wait.c: New file, implements
windows_status_to_termsig.
* gdbsupport/gdb_wait.h (WIFEXITED, WIFSIGNALED, WEXITSTATUS)
(WTERMSIG) [__MINGW32__]: Separate definitions for MinGW.
gdb/gdbserver/ChangeLog:
2020-01-06 Eli Zaretskii <eliz@gnu.org>
Pedro Alves <palves@redhat.com>
* win32-low.c (get_child_debug_event): Extract the fatal exception
from the exit status and convert to the equivalent Posix signal
number.
(win32_wait): Allow TARGET_WAITKIND_SIGNALLED status as well.
* Makefile.in (OBS, SFILES): Add gdb_wait.[co].
I noticed that get_exec_file could return a "const char *". This
patch implements this change.
I couldn't build all the code -- but I did build Linux native and a
mingw cross.
Consequently, the NTO code has a hack, where it casts away const. I
think this can be removed, but that required more work there, and
since I couldn't compile it, I felt it best not to try.
Let me know what you think.
gdb/ChangeLog
2019-12-16 Tom Tromey <tromey@adacore.com>
* windows-nat.c (windows_nat_target::attach): Update.
* remote.c (extended_remote_target::attach): Update.
* procfs.c (procfs_target::attach): Update.
* nto-procfs.c (nto_procfs_target::attach): Update.
(nto_procfs_target::create_inferior): Update.
* inf-ptrace.c (inf_ptrace_target::attach): Update.
* gnu-nat.c (gnu_nat_target::attach): Update.
(gnu_nat_target::detach): Update.
* darwin-nat.c (darwin_nat_target::attach): Update.
* corefile.c (get_exec_file): Constify result. Remove extraneous
return.
* bsd-kvm.c (bsd_kvm_target_open): Update.
* gdbsupport/common-inferior.h (get_exec_file): Constify result.
gdb/gdbserver/ChangeLog
2019-12-16 Tom Tromey <tromey@adacore.com>
* server.c (get_exec_file): Constify result.
Change-Id: I29c60f7313a7def0dcb290ff0c2a4c1dea4f981f
This provides threadsafety. Unfortunately, since libinproctrace.so
does not link to gnulib, we can't use it there, especially since it
still includes the gnulib headers (so it is difficult to directly
call the system strerror_r).
gdb/ChangeLog:
2019-11-26 Christian Biesinger <cbiesinger@google.com>
* linux-nat.c (detach_one_lwp): Call safe_strerror instead of
strerror.
* nto-procfs.c (nto_procfs_target::create_inferior): Likewise.
* windows-nat.c (windows_nat_target::create_inferior): Likewise.
gdb/gdbserver/ChangeLog:
2019-11-26 Christian Biesinger <cbiesinger@google.com>
* debug.c (debug_set_output): Call safe_strerror instead of
strerror.
* linux-low.c (attach_proc_task_lwp_callback): Likewise.
(linux_kill_one_lwp): Likewise.
(linux_detach_one_lwp): Likewise.
(linux_wait_for_event_filtered): Likewise.
(store_register): Likewise.
* lynx-low.c (lynx_attach): Likewise.
* mem-break.c (insert_memory_breakpoint): Likewise.
(remove_memory_breakpoint): Likewise.
(delete_fast_tracepoint_jump): Likewise.
(set_fast_tracepoint_jump): Likewise.
(uninsert_fast_tracepoint_jumps_at): Likewise.
(reinsert_fast_tracepoint_jumps_at): Likewise.
* nto-low.c (nto_xfer_memory): Likewise.
(nto_resume): Likewise.
Change-Id: I9e259cdcaa6e11bbcc4ee6bdc5b7127d73e11abe
When DebugActiveProcess fails, the error message is fairly generic:
error (_("Can't attach to process."));
It would be more useful for diagnosing problems if the Windows error
code was included in the message. This patch implements this.
gdb/ChangeLog
2019-11-19 Tom Tromey <tromey@adacore.com>
* windows-nat.c (windows_nat_target::attach): Include GetLastError
result in error when DebugActiveProcess fails.
Change-Id: Ie1bf502a0d96bb7c09bd5b1c5e0c924ba58cd68c
One spot in windows-nat.c uses %ld to print the TID, but all other
spots use %x, as does the infrun logging. This makes it unnecessarily
hard to tell which other log messages correspond to this one. This
patch changes the one outlier to use %x.
gdb/ChangeLog
2019-10-15 Tom Tromey <tromey@adacore.com>
* windows-nat.c (windows_nat_target::resume): Use %x when logging
TID.
Change-Id: Ic66efeb8a7ec08e7fb007320318f51acbf976734
A couple of spots in windows-nat.c used the name "pid" to refer to the
thread ID. I found this confusing, so this patch changes the names.
gdb/ChangeLog
2019-10-15 Tom Tromey <tromey@adacore.com>
* windows-nat.c (windows_nat_target::fetch_registers)
(windows_nat_target::store_registers): Rename "pid" to "tid".
Change-Id: Ia1a447e8da822d01ad94a5ca3760342bbdc0e66c
windows_thread_info_struct::sf is unused, as is
struct safe_symbol_file_add_args in windows-nat.c.
This patch removes them both. Tested by grep and
rebuilding.
gdb/ChangeLog
2019-10-08 Tom Tromey <tromey@adacore.com>
* windows-nat.c (struct windows_thread_info_struct) <sf>: Remove.
(struct safe_symbol_file_add_args): Remove.
I noticed that windows-nat.c includes buildsym-legacy.h -- but there's
no reason to do so, as windows-nat.c doesn't create any symbols.
gdb/ChangeLog
2019-10-08 Tom Tromey <tromey@adacore.com>
* windows-nat.c: Don't include buildsym-legacy.h.
This global is meant to point to the "main" thread of execution of
the program we are debugging. It is set when attaching to a process
or when receiving a CREATE_PROCESS_DEBUG_EVENT event. The theory at
the time was that this was also going to be the thread receiving
the EXIT_PROCESS_DEBUG_EVENT event.
Unfortunately, we have discovered since then that this is actually
not guaranteed. What this means in practice is that there is moderate
risk that main_thread_id refers to a thread which no longer exists.
This global is used in 3 situations:
- OUTPUT_DEBUG_STRING_EVENT
- LOAD_DLL_DEBUG_EVENT
- UNLOAD_DLL_DEBUG_EVENT
It's not clear why we would need to use the main_thread_id in those cases
instead of using the thread ID provided by the kernel events itself.
So this patch implements this approach, which then allows us to delete
the main_thread_id global.
gdb/testsuite:
* windows-nat.c (main_thread_id): Delete.
(handle_output_debug_string): Replace main_thread_id by
current_event.dwThreadId.
(fake_create_process): Likewise.
(get_windows_debug_event) <CREATE_PROCESS_DEBUG_EVENT>:
Do not set main_thread_id.
<LOAD_DLL_DEBUG_EVENT>: Replace main_thread_id by
current_event.dwThreadId.
<UNLOAD_DLL_DEBUG_EVENT>: Likewise.
We have observed that GDB would randomly trip the following
assertion failure when debugging on Windows. When allowing
the program to run until the inferior exits, we occasionally see:
(gdb) cont
Continuing.
[Thread 48192.0xd100 exited with code 1]
[Thread 48192.0x10ad8 exited with code 1]
[Thread 48192.0x36e28 exited with code 0]
[Thread 48192.0x52be4 exited with code 0]
[Thread 48192.0x5aa40 exited with code 0]
../../src/gdb/thread.c:453: internal-error: void delete_thread_1(thread_inf
o*, bool): Assertion `thr != nullptr' failed.
Running the same scenario with some additional traces enabled...
(gdb) set verbose
(gdb) set debugevents
... allows us to understand what the issue is. To understand, we need
to first look at the events received when starting the program, and
in particular which threads got created how. First, we get a
CREATE_PROCESS_DEBUG_EVENT for tid=0x442a8:
gdb: kernel event for pid=317536 tid=0x442a8 code=CREATE_PROCESS_DEBUG_EVENT)
Shortly after, we get some CREATE_THREAD_DEBUG_EVENT events,
one of them being for tid=0x4010c:
gdb: kernel event for pid=317536 tid=0x4010c code=CREATE_THREAD_DEBUG_EVENT)
Fast forward a bit of debugging, and we do a "cont" as above,
at which point the programs reaches the end, and the system reports
"exit" events. The first interesting one is the following:
gdb: kernel event for pid=317536 tid=0x442a8 code=EXIT_THREAD_DEBUG_EVENT)
This is reporting a thread-exit event for a thread whose tid
is the TID of what we call the "main thread". That's the thread
that was created when we received the CREATE_PROCESS_DEBUG_EVENT
notification, and whose TID is actually stored in a global variable
named main_thread_id. This is not something we expected, as
the assumption we made was that the main thread would exit last,
and we would be notified of it via an EXIT_PROCESS_DEBUG_EVENT.
But apparently, this is not always true, at least on Windows Server
2012 and 2016 where this issue has been observed happening randomly.
The consequence of the above notification is that we call
windows_delete_thread for that thread, which removes it from
our list of known threads.
And a little bit later, then we then get the EXIT_PROCESS_DEBUG_EVENT,
and we can see that the associated tid is not the main_thread_id,
but rather the tid of one of the threads that was created during
the lifetime of the program, in this case tid=0x4010c:
gdb: kernel event for pid=317536 tid=0x4010c code=EXIT_PROCESS_DEBUG_EVENT)
And the debug trace printed right after shows why we're crashing:
[Deleting Thread 317536.0x442a8]
We are trying to delete the thread whose tid=0x442a8, which is
the main_thread_id! As we have already deleted that thread before,
the search for it returns a nullptr, which then trips the assertion
check in delete_thread_1.
This commit fixes this issue. It ignores the open question of
what to do with the main_thread_id global, particularly after
that thread has been removed from our list of threads. This will
be dealt with as a separate patch, to allow cherry-picking
this patch into a release branch.
For now, we fix the code so as to avoid this crash.
gdb/ChangeLog:
* windows-nat.c (get_windows_debug_event) <EXIT_PROCESS_DEBUG_EVENT>:
Use current_event.dwThreadId instead of main_thread_id.
This rewrites gdb's TRY/CATCH to plain C++ try/catch. The patch was
largely written by script, though one change (to a comment in
common-exceptions.h) was reverted by hand.
gdb/ChangeLog
2019-04-08 Tom Tromey <tom@tromey.com>
* xml-support.c: Use C++ exception handling.
* x86-linux-nat.c: Use C++ exception handling.
* windows-nat.c: Use C++ exception handling.
* varobj.c: Use C++ exception handling.
* value.c: Use C++ exception handling.
* valprint.c: Use C++ exception handling.
* valops.c: Use C++ exception handling.
* unittests/parse-connection-spec-selftests.c: Use C++ exception
handling.
* unittests/cli-utils-selftests.c: Use C++ exception handling.
* typeprint.c: Use C++ exception handling.
* tui/tui.c: Use C++ exception handling.
* tracefile-tfile.c: Use C++ exception handling.
* top.c: Use C++ exception handling.
* thread.c: Use C++ exception handling.
* target.c: Use C++ exception handling.
* symmisc.c: Use C++ exception handling.
* symfile-mem.c: Use C++ exception handling.
* stack.c: Use C++ exception handling.
* sparc64-linux-tdep.c: Use C++ exception handling.
* solib.c: Use C++ exception handling.
* solib-svr4.c: Use C++ exception handling.
* solib-spu.c: Use C++ exception handling.
* solib-frv.c: Use C++ exception handling.
* solib-dsbt.c: Use C++ exception handling.
* selftest-arch.c: Use C++ exception handling.
* s390-tdep.c: Use C++ exception handling.
* rust-lang.c: Use C++ exception handling.
* rust-exp.y: Use C++ exception handling.
* rs6000-tdep.c: Use C++ exception handling.
* rs6000-aix-tdep.c: Use C++ exception handling.
* riscv-tdep.c: Use C++ exception handling.
* remote.c: Use C++ exception handling.
* remote-fileio.c: Use C++ exception handling.
* record-full.c: Use C++ exception handling.
* record-btrace.c: Use C++ exception handling.
* python/python.c: Use C++ exception handling.
* python/py-value.c: Use C++ exception handling.
* python/py-utils.c: Use C++ exception handling.
* python/py-unwind.c: Use C++ exception handling.
* python/py-type.c: Use C++ exception handling.
* python/py-symbol.c: Use C++ exception handling.
* python/py-record.c: Use C++ exception handling.
* python/py-record-btrace.c: Use C++ exception handling.
* python/py-progspace.c: Use C++ exception handling.
* python/py-prettyprint.c: Use C++ exception handling.
* python/py-param.c: Use C++ exception handling.
* python/py-objfile.c: Use C++ exception handling.
* python/py-linetable.c: Use C++ exception handling.
* python/py-lazy-string.c: Use C++ exception handling.
* python/py-infthread.c: Use C++ exception handling.
* python/py-inferior.c: Use C++ exception handling.
* python/py-gdb-readline.c: Use C++ exception handling.
* python/py-framefilter.c: Use C++ exception handling.
* python/py-frame.c: Use C++ exception handling.
* python/py-finishbreakpoint.c: Use C++ exception handling.
* python/py-cmd.c: Use C++ exception handling.
* python/py-breakpoint.c: Use C++ exception handling.
* python/py-arch.c: Use C++ exception handling.
* printcmd.c: Use C++ exception handling.
* ppc-linux-tdep.c: Use C++ exception handling.
* parse.c: Use C++ exception handling.
* p-valprint.c: Use C++ exception handling.
* objc-lang.c: Use C++ exception handling.
* mi/mi-main.c: Use C++ exception handling.
* mi/mi-interp.c: Use C++ exception handling.
* mi/mi-cmd-stack.c: Use C++ exception handling.
* mi/mi-cmd-break.c: Use C++ exception handling.
* main.c: Use C++ exception handling.
* linux-thread-db.c: Use C++ exception handling.
* linux-tdep.c: Use C++ exception handling.
* linux-nat.c: Use C++ exception handling.
* linux-fork.c: Use C++ exception handling.
* linespec.c: Use C++ exception handling.
* language.c: Use C++ exception handling.
* jit.c: Use C++ exception handling.
* infrun.c: Use C++ exception handling.
* infcmd.c: Use C++ exception handling.
* infcall.c: Use C++ exception handling.
* inf-loop.c: Use C++ exception handling.
* i386-tdep.c: Use C++ exception handling.
* i386-linux-tdep.c: Use C++ exception handling.
* guile/scm-value.c: Use C++ exception handling.
* guile/scm-type.c: Use C++ exception handling.
* guile/scm-symtab.c: Use C++ exception handling.
* guile/scm-symbol.c: Use C++ exception handling.
* guile/scm-pretty-print.c: Use C++ exception handling.
* guile/scm-ports.c: Use C++ exception handling.
* guile/scm-param.c: Use C++ exception handling.
* guile/scm-math.c: Use C++ exception handling.
* guile/scm-lazy-string.c: Use C++ exception handling.
* guile/scm-frame.c: Use C++ exception handling.
* guile/scm-disasm.c: Use C++ exception handling.
* guile/scm-cmd.c: Use C++ exception handling.
* guile/scm-breakpoint.c: Use C++ exception handling.
* guile/scm-block.c: Use C++ exception handling.
* guile/guile-internal.h: Use C++ exception handling.
* gnu-v3-abi.c: Use C++ exception handling.
* gdbtypes.c: Use C++ exception handling.
* frame.c: Use C++ exception handling.
* frame-unwind.c: Use C++ exception handling.
* fbsd-tdep.c: Use C++ exception handling.
* f-valprint.c: Use C++ exception handling.
* exec.c: Use C++ exception handling.
* event-top.c: Use C++ exception handling.
* event-loop.c: Use C++ exception handling.
* eval.c: Use C++ exception handling.
* dwarf2read.c: Use C++ exception handling.
* dwarf2loc.c: Use C++ exception handling.
* dwarf2-frame.c: Use C++ exception handling.
* dwarf2-frame-tailcall.c: Use C++ exception handling.
* dwarf-index-write.c: Use C++ exception handling.
* dwarf-index-cache.c: Use C++ exception handling.
* dtrace-probe.c: Use C++ exception handling.
* disasm-selftests.c: Use C++ exception handling.
* darwin-nat.c: Use C++ exception handling.
* cp-valprint.c: Use C++ exception handling.
* cp-support.c: Use C++ exception handling.
* cp-abi.c: Use C++ exception handling.
* corelow.c: Use C++ exception handling.
* completer.c: Use C++ exception handling.
* compile/compile-object-run.c: Use C++ exception handling.
* compile/compile-object-load.c: Use C++ exception handling.
* compile/compile-cplus-symbols.c: Use C++ exception handling.
* compile/compile-c-symbols.c: Use C++ exception handling.
* common/selftest.c: Use C++ exception handling.
* common/new-op.c: Use C++ exception handling.
* cli/cli-script.c: Use C++ exception handling.
* cli/cli-interp.c: Use C++ exception handling.
* cli/cli-cmds.c: Use C++ exception handling.
* c-varobj.c: Use C++ exception handling.
* btrace.c: Use C++ exception handling.
* breakpoint.c: Use C++ exception handling.
* break-catch-throw.c: Use C++ exception handling.
* arch-utils.c: Use C++ exception handling.
* amd64-tdep.c: Use C++ exception handling.
* ada-valprint.c: Use C++ exception handling.
* ada-typeprint.c: Use C++ exception handling.
* ada-lang.c: Use C++ exception handling.
* aarch64-tdep.c: Use C++ exception handling.
gdb/gdbserver/ChangeLog
2019-04-08 Tom Tromey <tom@tromey.com>
* server.c: Use C++ exception handling.
* linux-low.c: Use C++ exception handling.
* gdbreplay.c: Use C++ exception handling.
DWORD type is not a long on 64-bit Cygwin, because that it is LP64.
Explicitly cast DWORD values to unsigned long and use an appropriate
format.
gdb/ChangeLog:
2019-03-28 Jon Turney <jon.turney@dronecode.org.uk>
* windows-nat.c (display_selector): Fixed format specifications
for 64-bit Cygwin.
There is unused variable text_vma in function windows_make_so. This
leads to build error on Windows using Cygwin.
gdb/ChangeLog:
2019-03-17 Vladimir Martyanov <vilgeforce@gmail.com>
PR gdb/24350
* windows-nat.c (windows_make_so): Remove unused text_vma variable.
There are a wrong format strings in function display_selector() in
file windows-nat.c. This leads to build error using Cygwin on Windows.
LDT_ENTRY.HighWord is a DWORD, which is unsigned long int, so the
format specification should be for long int, not simply int.
gdb/ChangeLog:
2019-03-17 Vladimir Martyanov <vilgeforce@gmail.com>
PR gdb/24351
* windows-nat.c (display_selector): Format specifications fixed
A customer noticed some mildly odd MI output, where CLI output was
split into multiple MI strings at unusual boundaries, like this:
~"$1 = (b => true"
~", p => 0x407260"
This is technically correct according to the MI spec, but still
unusual, in that there's no particular reason for the string to be
split where it is.
I tracked this down to a call to gdb_flush in generic_val_print.
Then, I went through all calls to gdb_flush and removed the ones I
thought were superfluous. In particular:
* Any call in the value-printing code;
* Likewise the type-printing code (just a single call); and
* Any call that immediately followed a printf that obviously
ended with a newline, my belief being that gdb's standard output
streams are line buffered (by inheriting the behavior from stdio)
Regression tested on x86-64 Fedora 29.
I didn't add a new test case. I tend to think we don't necessarily
want to specify this behavior in the tests. Let me know what you
think of this.
gdb/ChangeLog
2019-03-05 Tom Tromey <tromey@adacore.com>
* windows-nat.c (windows_nat_target::attach)
(windows_nat_target::detach): Don't call gdb_flush.
* valprint.c (generic_val_print, val_print, val_print_string):
Don't call gdb_flush.
* utils.c (defaulted_query): Don't call gdb_flush.
* typeprint.c (print_type_scalar): Don't call gdb_flush.
* target.c (target_announce_detach): Don't call gdb_flush.
* sparc64-tdep.c (adi_print_versions): Don't call gdb_flush.
* remote.c (extended_remote_target::attach): Don't call
gdb_flush.
* procfs.c (procfs_target::detach): Don't call gdb_flush.
* printcmd.c (do_examine): Don't call gdb_flush.
(info_display_command): Don't call gdb_flush.
* p-valprint.c (pascal_val_print): Don't call gdb_flush.
* nto-procfs.c (nto_procfs_target::attach): Don't call gdb_flush.
* memattr.c (info_mem_command): Don't call gdb_flush.
* mdebugread.c (mdebug_build_psymtabs): Don't call gdb_flush.
* m2-valprint.c (m2_val_print): Don't call gdb_flush.
* infrun.c (follow_exec, handle_command): Don't call gdb_flush.
* inf-ptrace.c (inf_ptrace_target::attach): Don't call gdb_flush.
* hppa-tdep.c (unwind_command): Don't call gdb_flush.
* gnu-nat.c (gnu_nat_target::attach): Don't call gdb_flush.
(gnu_nat_target::detach): Don't call gdb_flush.
* f-valprint.c (f_val_print): Don't call gdb_flush.
* darwin-nat.c (darwin_nat_target::attach): Don't call gdb_flush.
* cli/cli-script.c (read_command_lines): Don't call gdb_flush.
* cli/cli-cmds.c (shell_escape, print_disassembly): Don't call
gdb_flush.
* c-valprint.c (c_val_print): Don't call gdb_flush.
* ada-valprint.c (ada_print_scalar): Don't call gdb_flush.
This is a followup on a recent patch which, among other things
introduced the exit notification of the main thread in order
to be symetrical with the fact that a thread notification was
emitted before signaling its creation.
This patch takes the opposite approach of removing both creation
and exit notifications for that main thread, which is consistent
with what is done on other platforms such as GNU/Linux for instance.
gdb/ChangeLog
* windows-nat.c (windows_add_thread): Add new parameter
"main_thread_p" with default value set to false. Update
function documentation as well as all callers.
(windows_delete_thread): Likewise.
(fake_create_process): Update call to windows_add_thread.
(get_windows_debug_event) <CREATE_THREAD_DEBUG_EVENT>
<CREATE_PROCESS_DEBUG_EVENT>: Likewise.
<EXIT_THREAD_DEBUG_EVENT, EXIT_PROCESS_DEBUG_EVENT>: Update
call to windows_delete_thread.
Tested on x86-windows (MinGW) using AdaCore's testsuite.
Running any program twice on Windows current results in GDB crashing:
$ gdb -q any_program
(gdb) run
$ gdb dummy -batch -ex run -ex run
[New Thread 684960.0xe5878]
[New Thread 684960.0xd75ac]
[New Thread 684960.0xddac8]
[New Thread 684960.0xc1f50]
[Thread 684960.0xd75ac exited with code 0]
[Thread 684960.0xddac8 exited with code 0]
[Thread 684960.0xc1f50 exited with code 0]
[Inferior 1 (process 684960) exited normally]
(gdb) run
Segmentation fault
The crash happens while processing the CREATE_PROCESS_DEBUG_EVENT
for the second run; in particular, we have in get_windows_debug_event:
| case CREATE_PROCESS_DEBUG_EVENT:
| [...]
| if (main_thread_id)
| windows_delete_thread (ptid_t (current_event.dwProcessId, 0,
| main_thread_id),
| 0);
The problem is that main_thread_id is the TID of the main thread from
the *previous* inferior, and this code is trying to delete that
thread. The problem is that it is constructing a PTID by pairing
the TID of the previous inferior with the PID of the new inferior.
As a result, when we dig inside windows_delete_thread to see
how it would handle that, we see...
| delete_thread (find_thread_ptid (ptid));
Since the PTID is bogus, we end up calling delete_thread with
a NULL thread_info. It used to be harmless, turning the delete_thread
into a nop, but the following change...
| commit 0803633106
| Date: Thu Nov 22 16:09:14 2018 +0000
| Subject: Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc.
... changed delete_thread to get the list of threads from
the inferior, which itself is now accessed via the given
thread_info. This is the corresponding diff that shows the change:
| - for (tp = thread_list; tp; tpprev = tp, tp = tp->next)
| + for (tp = thr->inf->thread_list; tp; tpprev = tp, tp = tp->next)
As a result of this, passing a NULL thread_info is no longer
an option!
Stepping back a bit, the reason behind deleting the thread late
could be found in a patch from Dec 2003, which laconically explains:
| commit 87a45c9606
| Date: Fri Dec 26 00:39:04 2003 +0000
|
| * win32-nat.c (get_child_debug_event): Keep main thread id around
| even after thread exits since Windows insists on continuing to
| report events against it.
A look at the gdb-patches archives did not provide any additional
clues (https://www.sourceware.org/ml/gdb-patches/2003-12/msg00478.html).
It is not clear whether this is still needed or not. This patch
assumes that whatever isue there was, the versions of Windows
we currently support no longer have it.
With that in mind, this commit fixes the issue by deleting the thread
when the inferior sends the exit-process event as opposed to deleting it
later, while starting a new inferior.
This also restores the printing of the thread-exit notification for
the main thread, which was missing before. Looking at the transcript
of the example shown above, we can see 4 thread creation notifications,
and only 3 notifications for thread exits. Now creation and exit
notifications are balanced.
In the handling of EXIT_THREAD_DEBUG_EVENT, the main_thread_id
check is removed because deemed unnecessary: The main thread was
introduced by a CREATE_PROCESS_DEBUG_EVENT, and thus the kernel
is expected to report its death via EXIT_PROCESS_DEBUG_EVENT.
And finally, because the behavior of delete_thread did change
(albeit when getting a value we probably never expected to receive),
this patch also adds a gdb_assert. The purpose is to provide some
immediate information in case there are other callers that mistakenly
call delete_thread with a NULL thread info. This can be useful
information when direct debugging of GDB isn't an option.
gdb/ChangeLog:
* thread.c (delete_thread_1): Add gdb_assert that THR is not
NULL. Initialize tpprev to NULL instead of assigning it
to NULL on the next statement.
* windows-nat.c (windows_delete_thread): Remove check for
main_thread_id before printing thread exit notifications.
(get_windows_debug_event) <EXIT_THREAD_DEBUG_EVENT>:
Remove thread ID check against main_thread_id.
<CREATE_PROCESS_DEBUG_EVENT>: Remove call to
windows_delete_thread.
<EXIT_PROCESS_DEBUG_EVENT>: Add call to windows_delete_thread.
This commit applies all changes made after running the gdb/copyright.py
script.
Note that one file was flagged by the script, due to an invalid
copyright header
(gdb/unittests/basic_string_view/element_access/char/empty.cc).
As the file was copied from GCC's libstdc++-v3 testsuite, this commit
leaves this file untouched for the time being; a patch to fix the header
was sent to gcc-patches first.
gdb/ChangeLog:
Update copyright year range in all GDB files.
I noticed several places in gdb that were using getenv("SHELL") and
then falling back to "/bin/sh" if it returned NULL. This unifies
these into a single function.
gdb/ChangeLog
2018-10-27 Tom Tromey <tom@tromey.com>
* procfs.c (procfs_target::create_inferior): Use get_shell.
* cli/cli-cmds.c (shell_escape): Use get_shell.
* windows-nat.c (windows_nat_target::create_inferior): Use
get_shell.
* common/pathstuff.c (get_shell): New function.
* nat/fork-inferior.c (SHELL_FILE, get_startup_shell): Remove.
(fork_inferior): Use get_shell.
* common/pathstuff.h (get_shell): Declare.
This causes the inferior to stop with SIGTTIN if it tries to read from the
terminal after it has been continued.
See https://cygwin.com/ml/cygwin/2016-09/msg00285.html for reproduction.
Since MinGW doesn't have a tcsetpgrp(), I don't think this problem would be
observed there, but Cygwin does so target_terminal::ours() will call it.
Calling target_terminal::ours() here seems to be is no longer appropriate
after the "Merge async and sync code paths" changes (as the inferior is now
in a separate process group even in sync mode(?), which is always used on
Windows targets)
This call was added in commit c44537cf (and see
https://sourceware.org/ml/gdb-patches/2007-02/msg00167.html for what it
fixed, which is not regressed by this change)
When windows_nat_target::wait() is entered, the inferior is running (either
it's been just been started or attached to, or windows_continue() was
called), so grabbing the controlling terminal away from it here seems to be
wrong, since infrun.c takes care of calling target_terminal::ours() when the
inferior stops.
gdb/ChangeLog:
2018-08-02 Jon Turney <jon.turney@dronecode.org.uk>
* windows-nat.c (windows_nat_target::wait): Remove a spurious
target_terminal::ours().
Sergio pointed out that the Windows builder was failing due to the
-Wnarrowing patch, with:
../../binutils-gdb/gdb/windows-nat.c:301:27: error: narrowing conversion of '3221225477' from 'DWORD {aka long unsigned int}' to 'int' inside { } [-Wnarrowing]
{-1, GDB_SIGNAL_UNKNOWN}};
^
../../binutils-gdb/gdb/windows-nat.c:301:27: error: narrowing conversion of '3221225725' from 'DWORD {aka long unsigned int}' to 'int' inside { } [-Wnarrowing]
../../binutils-gdb/gdb/windows-nat.c:301:27: error: narrowing conversion of '2147483651' from 'DWORD {aka long unsigned int}' to 'int' inside { } [-Wnarrowing]
../../binutils-gdb/gdb/windows-nat.c:301:27: error: narrowing conversion of '2147483652' from 'DWORD {aka long unsigned int}' to 'int' inside { } [-Wnarrowing]
../../binutils-gdb/gdb/windows-nat.c:301:27: error: narrowing conversion of '3221225614' from 'DWORD {aka long unsigned int}' to 'int' inside { } [-Wnarrowing]
Looking into this, I found two things.
First, in struct xlate_exception, it is better to have "them" be of
type DWORD, as that's the type actually in use.
Second, struct xlate_exception and xlate are not used in this file,
because the code in windows_nat_target::resume is #if'd out.
This patch changes the type of "them", but also similarly #if's out
this object.
In order to avoid a narrowing warning from the -1 entry, at Pedro's
suggestion I have removed this and changed windows_nat_target::resume
to use ranged for.
Tested by rebuilding using the mingw toolchain on x86-64 Fedora 28. I
also tested it by temporarily removing the "#if 0"s and rebuilding.
gdb/ChangeLog
2018-08-29 Tom Tromey <tom@tromey.com>
* windows-nat.c (struct xlate_exception) <them>: Change type to
DWORD.
(xlate): Fix formatting. Remove last entry.
(struct xlate_exception, xlate): Comment out.
(windows_nat_target::resume): Use ranged for.
After f6ac5f3d "Convert struct target_ops to C++", we need to explicitly use
the global namespace when calling ::close() from windows_nat_target methods,
as that object has a close() method.
gdb/ChangeLog:
2018-07-14 Jon Turney <jon.turney@dronecode.org.uk>
* windows-nat.c (windows_nat_target::create_inferior): Update to
call close() in global namespace.
This patch fixes various unused variable warnings that are related to
conditional compilation. In these cases, either the variable is now
protected by the same #if as its uses, or the declaration is simply
lowered into the conditionally-compiled block.
gdb/ChangeLog
2018-07-22 Tom Tromey <tom@tromey.com>
* windows-nat.c (saved_context): Conditionally define.
* remote.c (remote_target::remote_btrace_maybe_reopen):
Conditionally declare "warned".
* inflow.c (sigquit_ours): Conditionally define.
(new_tty): Move "tty" declaration inside #if.
* guile/guile.c (guile_datadir): Conditionally define.
* charset.c (set_be_le_names): Move some declarations inside #if.
* btrace.c (parse_xml_btrace): Move "errcode" declaration inside
#if.
(parse_xml_btrace_conf): Likewise.
This introduces a new header, buildsym-legacy.h, and changes all the
symbol readers to use it. The idea is to put the function-based
interface, that relies on the buildsym_compunit global, into a
separate header. Then when a symbol reader is updated to use the new
interface, it can simply not include buildsym-legacy.h, so it's easy
to be sure that the new API is used everywhere.
gdb/ChangeLog
2018-07-20 Tom Tromey <tom@tromey.com>
* xcoffread.c: Include buildsym-legacy.h.
* windows-nat.c: Include buildsym-legacy.h.
* stabsread.c: Include buildsym-legacy.h.
* mdebugread.c: Include buildsym-legacy.h.
* buildsym-legacy.h: New file.
* buildsym-legacy.c: New file, from buildsym.c.
* go32-nat.c: Include buildsym-legacy.h.
* dwarf2read.c: Include buildsym-legacy.h.
* dbxread.c: Include buildsym-legacy.h.
* cp-namespace.c: Include buildsym-legacy.h.
* coffread.c: Include buildsym-legacy.h.
* buildsym.h: Move some contents to buildsym-legacy.h.
* buildsym.c: Include buildsym-legacy.h. Move many functions to
buildsym-legacy.c.
* Makefile.in (HFILES_NO_SRCDIR): Add buildsym-legacy.h.
This patch is a small reorganizational patch that splits
do_windows_fetch_inferior_registers into two parts:
(a) One part that first reloads the thread's context when needed,
and then decides based on the given register number whether
one register needs to be fetched or all of them.
This part is moved to windows_nat_target::fetch_registers.
(b) The rest of the code, which actually fetches the register value
and supplies it to the regcache.
A similar treatment is applied to do_windows_store_inferior_registers.
This change is preparation work for changing the way we calculate
the location of a given register in the thread context structure,
and should be a no op.
gdb/ChangeLog:
* windows-nat.c (do_windows_fetch_inferior_registers): Rename
to windows_fetch_one_register, and only handle the case of
fetching one register. Move the code that reloads the context
and iterates over all registers if R is negative to...
(windows_nat_target::fetch_registers): ... here.
(do_windows_store_inferior_registers): Rename to
windows_store_one_register, and only handle the case of storing
one register. Move the code that handles the case where r is
negative to...
(windows_nat_target::store_registers) ... here.
Tested on x86-windows and x86_64-windows using AdaCore's testsuite.
Commit 00431a78b2 ("Use thread_info and inferior pointers more
throughout") missed updating some callers, like e.g.,:
gdb/remote-sim.c: In member function 'virtual void gdbsim_target::mourn_inferior()':
gdb/remote-sim.c:1198:50: error: cannot convert 'ptid_t' to 'thread_info*' for argument '1' to 'void delete_thread_silent(thread_info*)'
delete_thread_silent (sim_data->remote_sim_ptid);
gdb/mygit/src/gdb/procfs.c: In member function ‘virtual void procfs_target::detach(inferior*, int)’:
gdb/mygit/src/gdb/procfs.c:1931:23: error: invalid conversion from ‘int’ to ‘inferior*’ [-fpermissive]
detach_inferior (pid);
^
In file included from gdb/mygit/src/gdb/procfs.c:24:0:
gdb/mygit/src/gdb/inferior.h:476:13: note: initializing argument 1 of ‘void detach_inferior(inferior*)’
etc.
This fixes it.
The delete_thread_silent calls in both go32-nat.c and remote-sim.c are
unnecessary because generic_mourn_inferior calls exit_inferior, which
deletes the inferior's threads.
gdb/ChangeLog:
2018-06-25 Pedro Alves <palves@redhat.com>
* windows-nat.c (windows_delete_thread): Use find_thread_ptid and
pass thread_info pointer to delete_thread.
(windows_nat_target::detach): Pass inferior pointer to
detach_inferior.
* aix-thread.c (sync_threadlists): Pass thread_info pointer to
delete_thread.
* bsd-kvm.c (bsd_kvm_target::close): Use discard_all_inferiors.
* darwin-nat.c (darwin_check_new_threads): Use find_thread_ptid
and pass a thread_info pointer to delete_thread.
* fbsd-nat.c (fbsd_nat_target::wait): Use find_thread_ptid and
pass thread_info pointer to delete_thread.
* go32-nat.c (go32_nat_target::mourn_inferior): Remove
delete_thread_silent call.
* procfs.c (procfs_target::detach): Pass inferior pointer to
detach_inferior.
(procfs_target::wait): Pass thread_info pointer to delete_thread.
* remote-sim.c (gdbsim_target::mourn_inferior): Remove
delete_thread_silent call.
* windows-nat.c (windows_delete_thread): Use find_thread_ptid and
pass thread_info pointer to delete_thread.
(windows_nat_target::detach): Pass inferior pointer to
delete_inferior.
I noticed that the mingw build was failing in the buildbot. This
patch fixes the problem. I'm checking it in as obvious.
gdb/ChangeLog
2018-06-08 Tom Tromey <tom@tromey.com>
* windows-nat.c (windows_nat_target::xfer_partial): "beneath" is
now a method.
On Windows, using the "-list-thread-groups --available" GDB/MI command
before an inferior is being debugged:
% gdb -q -i=mi
=thread-group-added,id="i1"
=cmd-param-changed,param="auto-load safe-path",value="/"
(gdb)
-list-thread-groups --available
Segmentation fault
Ooops!
The SEGV happens because the -list-thread-groups --available command
triggers a windows_nat_target::xfer_partial call for a TARGET_OBJECT_OSDATA
object. Until a program is being debugged, the target_ops layer that
gets the call is the Windows "native" layer. Except for a couple of
specific objects (TARGET_OBJECT_MEMORY and TARGET_OBJECT_LIBRARIES),
this layer's xfer_partial method delegates the xfer of other objects
to the target beneath:
default:
return beneath->xfer_partial (object, annex,
readbuf, writebuf, offset, len,
xfered_len);
Unfortunately, there is no "beneath layer" in this case, so
beneath is NULL and dereferencing it leads to the SEGV.
This patch fixes the issue by checking beneath before trying
to delegate the request.
gdb/ChangeLog:
* windows-nat.c (windows_nat_target::xfer_partial): Return
TARGET_XFER_E_IO if we need to delegate to the target beneath
but BENEATH is NULL.
gdb/testsuite/ChangeLog:
* gdb.mi/list-thread-groups-no-inferior.exp: New testcase.
Hannes Domani
Simon Marchi
Pedro Alves
Eli Zaretskii
Joel Brobecker
Tom Tromey
Christian Biesinger
Tom de Vries
Alan Modra
Tom Tromey
Jon Turney
Владимир Мартьянов
Simon Marchi