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.
- Make get_last_target_status arguments optional. A following patch
will add another argument to get_last_target_status (the event's
target), and passing nullptr when we don't care for some piece of
info is handier than creating dummy local variables.
- Declare nullify_last_target_wait_ptid in a header, and remove the
local extern declaration from linux-fork.c.
gdb/ChangeLog:
2020-01-10 Pedro Alves <palves@redhat.com>
* break-catch-sig.c (signal_catchpoint_print_it): Don't pass a
ptid to get_last_target_status.
* break-catch-syscall.c (print_it_catch_syscall): Don't pass a
ptid to get_last_target_status.
* infcmd.c (continue_command): Don't pass a target_waitstatus to
get_last_target_status.
(info_program_command): Don't pass a target_waitstatus to
get_last_target_status.
* infrun.c (init_wait_for_inferior): Use
nullify_last_target_wait_ptid.
(get_last_target_status): Handle nullptr arguments.
(nullify_last_target_wait_ptid): Clear target_last_waitstatus.
(print_stop_event): Don't pass a ptid to get_last_target_status.
(normal_stop): Don't pass a ptid to get_last_target_status.
* infrun.h (get_last_target_status, set_last_target_status): Move
comments here and update.
(nullify_last_target_wait_ptid): Declare.
* linux-fork.c (fork_load_infrun_state): Remove local extern
declaration of nullify_last_target_wait_ptid.
* linux-nat.c (get_detach_signal): Don't pass a target_waitstatus
to get_last_target_status.
With this patch, the help docs now respect 2 invariants:
* The first line of a command help is terminated by a '.' character.
* The last character of a command help is not a newline character.
Note that the changes for the last invariant were done by Tom, as part of :
[PATCH] Remove trailing newlines from help text
https://sourceware.org/ml/gdb-patches/2019-06/msg00050.html
but some occurrences have been re-introduced since then.
Some help docs had to be rephrased/restructured to respect the above
invariants.
Before this patch, print_doc_line was printing the first line
of a command help documentation, but stopping at the first '.'
or ',' character.
This was giving inconsistent results :
* The first line of command helps was sometimes '.' terminated,
sometimes not.
* The first line of command helps was not always designed to be
readable/understandable/unambiguous when stopping at the first
'.' or ',' character.
This e.g. created the following inconsistencies/problems:
< catch exception -- Catch Ada exceptions
< catch handlers -- Catch Ada exceptions
< catch syscall -- Catch system calls by their names
< down-silently -- Same as the `down' command
while the new help is:
> catch exception -- Catch Ada exceptions, when raised.
> catch handlers -- Catch Ada exceptions, when handled.
> catch syscall -- Catch system calls by their names, groups and/or numbers.
> down-silently -- Same as the `down' command, but does not print anything.
Also, the command help doc should not be terminated by a newline
character, but this was not respected by all commands.
The cli-option -OPT framework re-introduced some occurences.
So, the -OPT build help framework was changed to not output newlines at the
end of %OPTIONS% replacement.
This patch changes the help documentations to ensure the 2 invariants
given above.
It implied to slightly rephrase or restructure some help docs.
Based on the above invariants, print_doc_line (called by
'apropos' and 'help' commands to print the first line of a command
help) now outputs the full first line of a command help.
This all results in a lot of small changes in the produced help docs.
There are less code changes than changes in the help docs, as a lot
of docs are produced by some code (e.g. the remote packet usage settings).
gdb/ChangeLog
2019-08-07 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* cli/cli-decode.h (print_doc_line): Add for_value_prefix argument.
* cli/cli-decode.c (print_doc_line): Likewise. It now prints
the full first line, except when FOR_VALUE_PREFIX. In this case,
the trailing '.' is not output, and the first character is uppercased.
(print_help_for_command): Update call to print_doc_line.
(print_doc_of_command): Likewise.
* cli/cli-setshow.c (deprecated_show_value_hack): Likewise.
* cli/cli-option.c (append_indented_doc): Do not append newline.
(build_help_option): Append newline after first appended_indented_doc
only if a second call is done.
(build_help): Append 2 new lines before each option, except the first
one.
* compile/compile.c (_initialize_compile): Add new lines after
%OPTIONS%, when not at the end of the help.
Change help doc or code
producing the help doc to respect the invariants.
* maint-test-options.c (_initialize_maint_test_options): Likewise.
Also removed the new line after 'Options:', as all other commands
do not put an empty line between 'Options:' and the first option.
* printcmd.c (_initialize_printcmd): Likewise.
* stack.c (_initialize_stack): Likewise.
* interps.c (interpreter_exec_cmd): Fix "Usage:" line that was
incorrectly telling COMMAND is optional.
* ada-lang.c (_initialize_ada_language): Change help doc or code
producing the help doc to respect the invariants.
* ada-tasks.c (_initialize_ada_tasks): Likewise.
* breakpoint.c (_initialize_breakpoint): Likewise.
* cli/cli-cmds.c (_initialize_cli_cmds): Likewise.
* cli/cli-logging.c (_initialize_cli_logging): Likewise.
* cli/cli-setshow.c (_initialize_cli_setshow): Likewise.
* cli/cli-style.c (cli_style_option::add_setshow_commands,
_initialize_cli_style): Likewise.
* corelow.c (core_target_info): Likewise.
* dwarf-index-cache.c (_initialize_index_cache): Likewise.
* dwarf2read.c (_initialize_dwarf2_read): Likewise.
* filesystem.c (_initialize_filesystem): Likewise.
* frame.c (_initialize_frame): Likewise.
* gnu-nat.c (add_task_commands): Likewise.
* infcall.c (_initialize_infcall): Likewise.
* infcmd.c (_initialize_infcmd): Likewise.
* interps.c (_initialize_interpreter): Likewise.
* language.c (_initialize_language): Likewise.
* linux-fork.c (_initialize_linux_fork): Likewise.
* maint-test-settings.c (_initialize_maint_test_settings): Likewise.
* maint.c (_initialize_maint_cmds): Likewise.
* memattr.c (_initialize_mem): Likewise.
* printcmd.c (_initialize_printcmd): Likewise.
* python/lib/gdb/function/strfns.py (_MemEq, _StrLen, _StrEq,
_RegEx): Likewise.
* ravenscar-thread.c (_initialize_ravenscar): Likewise.
* record-btrace.c (_initialize_record_btrace): Likewise.
* record-full.c (_initialize_record_full): Likewise.
* record.c (_initialize_record): Likewise.
* regcache-dump.c (_initialize_regcache_dump): Likewise.
* regcache.c (_initialize_regcache): Likewise.
* remote.c (add_packet_config_cmd, init_remote_threadtests,
_initialize_remote): Likewise.
* ser-tcp.c (_initialize_ser_tcp): Likewise.
* serial.c (_initialize_serial): Likewise.
* skip.c (_initialize_step_skip): Likewise.
* source.c (_initialize_source): Likewise.
* stack.c (_initialize_stack): Likewise.
* symfile.c (_initialize_symfile): Likewise.
* symtab.c (_initialize_symtab): Likewise.
* target-descriptions.c (_initialize_target_descriptions): Likewise.
* top.c (init_main): Likewise.
* tracefile-tfile.c (tfile_target_info): Likewise.
* tracepoint.c (_initialize_tracepoint): Likewise.
* tui/tui-win.c (_initialize_tui_win): Likewise.
* utils.c (add_internal_problem_command): Likewise.
* valprint.c (value_print_option_defs): Likewise.
gdb/testsuite/ChangeLog
2019-08-07 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* gdb.base/style.exp: Update tests for help doc new invariants.
* gdb.base/help.exp: Likewise.
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.
All fork_save_infrun_state callers pass '1' as CLOBBER_REGS nowadays.
The larger hunk in fork_save_infrun_state is just a reindentation.
gdb/ChangeLog:
2019-03-06 Pedro Alves <palves@redhat.com>
* linux-fork.c (fork_info::clobber_regs): Delete.
(fork_load_infrun_state): Remove reference to 'clobber_regs'.
(fork_save_infrun_state): Remove 'clobber_regs' parameter. Update
comment. Adjust.
(scoped_switch_fork_info::scoped_switch_fork_info)
(checkpoint_command, linux_fork_context): Adjust
fork_save_infrun_state calls.
There's no need to iterate over all threads of all inferiors here.
gdb/ChangeLog:
2019-03-06 Pedro Alves <palves@redhat.com>
* linux-fork.c (inf_has_multiple_thread_cb): Delete.
(inf_has_multiple_threads): Return 'bool' and rewrite using
inferior_info::threads().
Don't rely on "inferior_ptid" deep within add_fork. In the
multi-target branch, I'm forcing inferior_ptid to null_ptid early in
infrun event handling to make sure we don't inadvertently rely on the
current thread/target when we shouldn't, and that caught some bad or
unnecessary assumptions throughout.
gdb/ChangeLog:
2019-03-06 Pedro Alves <palves@redhat.com>
* linux-fork.c (new_fork): New, split out of ...
(add_fork): ... this. Return void. Move "first fork" special
case from here, to ...
(checkpoint_command): ... here.
* linux-linux.h (add_fork): Return void.
The previous commit:
commit 1ef8573cc7
Date: Wed Jan 9 14:02:39 2019 +0000
gdb: Improve scoped_switch_fork_info class
contained a bug, an incorrect variable name was used. Fixed in this
commit.
gdb/ChangeLog:
* linux-fork.c (scoped_switch_fork_info)
<~scoped_switch_fork_info>: Fix incorrect variable name.
After committing this patch I got this feedback:
https://sourceware.org/ml/gdb-patches/2019-01/msg00181.html
This patch makes the constructor of scoped_switch_fork_info explicit,
and wraps the core of the destructor in a TRY/CATCH block.
I've run this through the testsuite on X86-64/GNU Linux, however, this
code is not exercised, so this patch is untested.
gdb/ChangeLog:
* linux-fork.c (scoped_switch_fork_info)
<scoped_switch_fork_info>: Make explicit.
<~scoped_switch_fork_info>: Wrap core in TRY/CATCH.
Replace cleanup in linux-fork.c:inferior_call_waitpid with a RAII
object.
gdb/ChangeLog:
* linux-fork.c (class scoped_switch_fork_info): New class.
(inferior_call_waitpid): Update to use scoped_switch_fork_info.
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.
This replaces a few uses of pointer+length with gdb::array_view, in
call_function_by_hand and related code.
Unfortunately, due to -Wnarrowing, there are places where we can't
brace-initialize an gdb::array_view without an ugly-ish cast. To
avoid the cast, this patch introduces a gdb::make_array_view function.
Unit tests included.
This patch in isolation may not look so interesting, due to
gdb::make_array_view uses, but I think it's still worth it. Some of
the gdb::make_array_view calls disappear down the series, and others
could be eliminated with more (non-trivial) gdb::array_view
detangling/conversion (e.g. code around eval_call). See this as a "we
have to start somewhere" patch.
gdb/ChangeLog:
2018-11-21 Pedro Alves <palves@redhat.com>
* ada-lang.c (ada_evaluate_subexp): Adjust to pass an array_view.
* common/array-view.h (make_array_view): New.
* compile/compile-object-run.c (compile_object_run): Adjust to
pass an array_view.
* elfread.c (elf_gnu_ifunc_resolve_addr): Adjust.
* eval.c (eval_call): Adjust to pass an array_view.
(evaluate_subexp_standard): Adjust to pass an array_view.
* gcore.c (call_target_sbrk): Adjust to pass an array_view.
* guile/scm-value.c (gdbscm_value_call): Likewise.
* infcall.c (push_dummy_code): Replace pointer + size parameters
with an array_view parameter.
(call_function_by_hand, call_function_by_hand_dummy): Likewise and
adjust.
* infcall.h: Include "common/array-view.h".
(call_function_by_hand, call_function_by_hand_dummy): Replace
pointer + size parameters with an array_view parameter.
* linux-fork.c (inferior_call_waitpid): Adjust to use array_view.
* linux-tdep.c (linux_infcall_mmap): Likewise.
* objc-lang.c (lookup_objc_class, lookup_child_selector)
(value_nsstring, print_object_command): Likewise.
* python/py-value.c (valpy_call): Likewise.
* rust-lang.c (rust_evaluate_funcall): Likewise.
* spu-tdep.c (flush_ea_cache): Likewise.
* valarith.c (value_x_binop, value_x_unop): Likewise.
* valops.c (value_allocate_space_in_inferior): Likewise.
* unittests/array-view-selftests.c (run_tests): Add
gdb::make_array_view test.
In my multi-target work, I need to add a few more
scoped_restore_current_thread and switch_to_thread calls in some
places, and in some lower-level places I was fighting against the fact
that switch_to_thread reads/refreshes the stop_pc global.
Instead of piling on workarounds, let's just finally eliminate the
stop_pc global. We already have the per-thread
thread_info->suspend.stop_pc field, so it's mainly a matter of using
that more/instead.
gdb/ChangeLog:
2018-06-28 Pedro Alves <palves@redhat.com>
* gdbthread.h (struct thread_suspend_state) <stop_pc>: Extend
comments.
(switch_to_thread_no_regs): Adjust comment.
* infcmd.c (stop_pc): Delete.
(post_create_inferior, info_program_command): Replace references
to stop_pc with references to thread_info->suspend.stop_pc.
* inferior.h (stop_pc): Delete declaration.
* infrun.c (proceed, handle_syscall_event, fill_in_stop_func)
(handle_inferior_event_1, handle_signal_stop)
(process_event_stop_test, keep_going_stepped_thread)
(handle_step_into_function, handle_step_into_function_backward)
(print_stop_location): Replace references to stop_pc with
references to thread_info->suspend.stop_pc.
(struct infcall_suspend_state) <stop_pc>: Delete field.
(save_infcall_suspend_state, restore_infcall_suspend_state):
Remove references to inf_stat->stop_pc.
* linux-fork.c (fork_load_infrun_state): Likewise.
* record-btrace.c (record_btrace_set_replay): Likewise.
* record-full.c (record_full_goto_entry): Likewise.
* remote.c (print_one_stopped_thread): Likewise.
* target.c (target_resume): Extend comment.
* thread.c (set_executing_thread): New.
(set_executing): Use it.
(switch_to_thread_no_regs, switch_to_no_thread, switch_to_thread):
Remove references to stop_pc.
This is more preparation bits for multi-target support.
In a multi-target scenario, we need to address the case of different
processes/threads running on different targets that happen to have the
same PID/PTID. E.g., we can have both process 123 in target 1, and
process 123 in target 2, while they're in reality different processes
running on different machines. Or maybe we've loaded multiple
instances of the same core file. Etc.
To address this, in my WIP multi-target branch, threads and processes
are uniquely identified by the (process_stratum target_ops *, ptid_t)
and (process_stratum target_ops *, pid) tuples respectively. I.e.,
each process_stratum instance has its own thread/process number space.
As you can imagine, that requires passing around target_ops * pointers
in a number of functions where we're currently passing only a ptid_t
or an int. E.g., when we look up a thread_info object by ptid_t in
find_thread_ptid, the ptid_t alone isn't sufficient.
In many cases though, we already have the thread_info or inferior
pointer handy, but we "lose" it somewhere along the call stack, only
to look it up again by ptid_t/pid. Since thread_info or inferior
objects know their parent target, if we pass around thread_info or
inferior pointers when possible, we avoid having to add extra
target_ops parameters to many functions, and also, we eliminate a
number of by ptid_t/int lookups.
So that's what this patch does. In a bit more detail:
- Changes a number of functions and methods to take a thread_info or
inferior pointer instead of a ptid_t or int parameter.
- Changes a number of structure fields from ptid_t/int to inferior or
thread_info pointers.
- Uses the inferior_thread() function whenever possible instead of
inferior_ptid.
- Uses thread_info pointers directly when possible instead of the
is_running/is_stopped etc. routines that require a lookup.
- A number of functions are eliminated along the way, such as:
int valid_gdb_inferior_id (int num);
int pid_to_gdb_inferior_id (int pid);
int gdb_inferior_id_to_pid (int num);
int in_inferior_list (int pid);
- A few structures and places hold a thread_info pointer across
inferior execution, so now they take a strong reference to the
(refcounted) thread_info object to avoid the thread_info pointer
getting stale. This is done in enable_thread_stack_temporaries and
in the infcall.c code.
- Related, there's a spot in infcall.c where using a RAII object to
handle the refcount would be handy, so a gdb::ref_ptr specialization
for thread_info is added (thread_info_ref, in gdbthread.h), along
with a gdb_ref_ptr policy that works for all refcounted_object types
(in common/refcounted-object.h).
gdb/ChangeLog:
2018-06-21 Pedro Alves <palves@redhat.com>
* ada-lang.h (ada_get_task_number): Take a thread_info pointer
instead of a ptid_t. All callers adjusted.
* ada-tasks.c (ada_get_task_number): Likewise. All callers
adjusted.
(print_ada_task_info, display_current_task_id, task_command_1):
Adjust.
* breakpoint.c (watchpoint_in_thread_scope): Adjust to use
inferior_thread.
(breakpoint_kind): Adjust.
(remove_breakpoints_pid): Rename to ...
(remove_breakpoints_inf): ... this. Adjust to take an inferior
pointer. All callers adjusted.
(bpstat_clear_actions): Use inferior_thread.
(get_bpstat_thread): New.
(bpstat_do_actions): Use it.
(bpstat_check_breakpoint_conditions, bpstat_stop_status): Adjust
to take a thread_info pointer. All callers adjusted.
(set_longjmp_breakpoint_for_call_dummy, set_momentary_breakpoint)
(breakpoint_re_set_thread): Use inferior_thread.
* breakpoint.h (struct inferior): Forward declare.
(bpstat_stop_status): Update.
(remove_breakpoints_pid): Delete.
(remove_breakpoints_inf): New.
* bsd-uthread.c (bsd_uthread_target::wait)
(bsd_uthread_target::update_thread_list): Use find_thread_ptid.
* btrace.c (btrace_add_pc, btrace_enable, btrace_fetch)
(maint_btrace_packet_history_cmd)
(maint_btrace_clear_packet_history_cmd): Adjust.
(maint_btrace_clear_cmd, maint_info_btrace_cmd): Adjust to use
inferior_thread.
* cli/cli-interp.c: Include "inferior.h".
* common/refcounted-object.h (struct
refcounted_object_ref_policy): New.
* compile/compile-object-load.c: Include gdbthread.h.
(store_regs): Use inferior_thread.
* corelow.c (core_target::close): Use current_inferior.
(core_target_open): Adjust to use first_thread_of_inferior and use
the current inferior.
* ctf.c (ctf_target::close): Adjust to use current_inferior.
* dummy-frame.c (dummy_frame_id) <ptid>: Delete, replaced by ...
<thread>: ... this new field. All references adjusted.
(dummy_frame_pop, dummy_frame_discard, register_dummy_frame_dtor):
Take a thread_info pointer instead of a ptid_t.
* dummy-frame.h (dummy_frame_push, dummy_frame_pop)
(dummy_frame_discard, register_dummy_frame_dtor): Take a
thread_info pointer instead of a ptid_t.
* elfread.c: Include "inferior.h".
(elf_gnu_ifunc_resolver_stop, elf_gnu_ifunc_resolver_return_stop):
Use inferior_thread.
* eval.c (evaluate_subexp): Likewise.
* frame.c (frame_pop, has_stack_frames, find_frame_sal): Use
inferior_thread.
* gdb_proc_service.h (struct thread_info): Forward declare.
(struct ps_prochandle) <ptid>: Delete, replaced by ...
<thread>: ... this new field. All references adjusted.
* gdbarch.h, gdbarch.c: Regenerate.
* gdbarch.sh (get_syscall_number): Replace 'ptid' parameter with a
'thread' parameter. All implementations and callers adjusted.
* gdbthread.h (thread_info) <set_running>: New method.
(delete_thread, delete_thread_silent): Take a thread_info pointer
instead of a ptid.
(global_thread_id_to_ptid, ptid_to_global_thread_id): Delete.
(first_thread_of_process): Delete, replaced by ...
(first_thread_of_inferior): ... this new function. All callers
adjusted.
(any_live_thread_of_process): Delete, replaced by ...
(any_live_thread_of_inferior): ... this new function. All callers
adjusted.
(switch_to_thread, switch_to_no_thread): Declare.
(is_executing): Delete.
(enable_thread_stack_temporaries): Update comment.
<enable_thread_stack_temporaries>: Take a thread_info pointer
instead of a ptid_t. Incref the thread.
<~enable_thread_stack_temporaries>: Decref the thread.
<m_ptid>: Delete
<m_thr>: New.
(thread_stack_temporaries_enabled_p, push_thread_stack_temporary)
(get_last_thread_stack_temporary)
(value_in_thread_stack_temporaries, can_access_registers_thread):
Take a thread_info pointer instead of a ptid_t. All callers
adjusted.
* infcall.c (get_call_return_value): Use inferior_thread.
(run_inferior_call): Work with thread pointers instead of ptid_t.
(call_function_by_hand_dummy): Work with thread pointers instead
of ptid_t. Use thread_info_ref.
* infcmd.c (proceed_thread_callback): Access thread's state
directly.
(ensure_valid_thread, ensure_not_running): Use inferior_thread,
access thread's state directly.
(continue_command): Use inferior_thread.
(info_program_command): Use find_thread_ptid and access thread
state directly.
(proceed_after_attach_callback): Use thread state directly.
(notice_new_inferior): Take a thread_info pointer instead of a
ptid_t. All callers adjusted.
(exit_inferior): Take an inferior pointer instead of a pid. All
callers adjusted.
(exit_inferior_silent): New.
(detach_inferior): Delete.
(valid_gdb_inferior_id, pid_to_gdb_inferior_id)
(gdb_inferior_id_to_pid, in_inferior_list): Delete.
(detach_inferior_command, kill_inferior_command): Use
find_inferior_id instead of valid_gdb_inferior_id and
gdb_inferior_id_to_pid.
(inferior_command): Use inferior and thread pointers.
* inferior.h (struct thread_info): Forward declare.
(notice_new_inferior): Take a thread_info pointer instead of a
ptid_t. All callers adjusted.
(detach_inferior): Delete declaration.
(exit_inferior, exit_inferior_silent): Take an inferior pointer
instead of a pid. All callers adjusted.
(gdb_inferior_id_to_pid, pid_to_gdb_inferior_id, in_inferior_list)
(valid_gdb_inferior_id): Delete.
* infrun.c (follow_fork_inferior, proceed_after_vfork_done)
(handle_vfork_child_exec_or_exit, follow_exec): Adjust.
(struct displaced_step_inferior_state) <pid>: Delete, replaced by
...
<inf>: ... this new field.
<step_ptid>: Delete, replaced by ...
<step_thread>: ... this new field.
(get_displaced_stepping_state): Take an inferior pointer instead
of a pid. All callers adjusted.
(displaced_step_in_progress_any_inferior): Adjust.
(displaced_step_in_progress_thread): Take a thread pointer instead
of a ptid_t. All callers adjusted.
(displaced_step_in_progress, add_displaced_stepping_state): Take
an inferior pointer instead of a pid. All callers adjusted.
(get_displaced_step_closure_by_addr): Adjust.
(remove_displaced_stepping_state): Take an inferior pointer
instead of a pid. All callers adjusted.
(displaced_step_prepare_throw, displaced_step_prepare)
(displaced_step_fixup): Take a thread pointer instead of a ptid_t.
All callers adjusted.
(start_step_over): Adjust.
(infrun_thread_ptid_changed): Remove bit updating ptids in the
displaced step queue.
(do_target_resume): Adjust.
(fetch_inferior_event): Use inferior_thread.
(context_switch, get_inferior_stop_soon): Take an
execution_control_state pointer instead of a ptid_t. All callers
adjusted.
(switch_to_thread_cleanup): Delete.
(stop_all_threads): Use scoped_restore_current_thread.
* inline-frame.c: Include "gdbthread.h".
(inline_state) <inline_state>: Take a thread pointer instead of a
ptid_t. All callers adjusted.
<ptid>: Delete, replaced by ...
<thread>: ... this new field.
(find_inline_frame_state): Take a thread pointer instead of a
ptid_t. All callers adjusted.
(skip_inline_frames, step_into_inline_frame)
(inline_skipped_frames, inline_skipped_symbol): Take a thread
pointer instead of a ptid_t. All callers adjusted.
* inline-frame.h (skip_inline_frames, step_into_inline_frame)
(inline_skipped_frames, inline_skipped_symbol): Likewise.
* linux-fork.c (delete_checkpoint_command): Adjust to use thread
pointers directly.
* linux-nat.c (get_detach_signal): Likewise.
* linux-thread-db.c (thread_from_lwp): New 'stopped' parameter.
(thread_db_notice_clone): Adjust.
(thread_db_find_new_threads_silently)
(thread_db_find_new_threads_2, thread_db_find_new_threads_1): Take
a thread pointer instead of a ptid_t. All callers adjusted.
* mi/mi-cmd-var.c: Include "inferior.h".
(mi_cmd_var_update_iter): Update to use thread pointers.
* mi/mi-interp.c (mi_new_thread): Update to use the thread's
inferior directly.
(mi_output_running_pid, mi_inferior_count): Delete, bits factored
out to ...
(mi_output_running): ... this new function.
(mi_on_resume_1): Adjust to use it.
(mi_user_selected_context_changed): Adjust to use inferior_thread.
* mi/mi-main.c (proceed_thread): Adjust to use thread pointers
directly.
(interrupt_thread_callback): : Adjust to use thread and inferior
pointers.
* proc-service.c: Include "gdbthread.h".
(ps_pglobal_lookup): Adjust to use the thread's inferior directly.
* progspace-and-thread.c: Include "inferior.h".
* progspace.c: Include "inferior.h".
* python/py-exitedevent.c (create_exited_event_object): Adjust to
hold a reference to an inferior_object.
* python/py-finishbreakpoint.c (bpfinishpy_init): Adjust to use
inferior_thread.
* python/py-inferior.c (struct inferior_object): Give the type a
tag name instead of a typedef.
(python_on_normal_stop): No need to check if the current thread is
listed.
(inferior_to_inferior_object): Change return type to
inferior_object. All callers adjusted.
(find_thread_object): Delete, bits factored out to ...
(thread_to_thread_object): ... this new function.
* python/py-infthread.c (create_thread_object): Use
inferior_to_inferior_object.
(thpy_is_stopped): Use thread pointer directly.
(gdbpy_selected_thread): Use inferior_thread.
* python/py-record-btrace.c (btpy_list_object) <ptid>: Delete
field, replaced with ...
<thread>: ... this new field. All users adjusted.
(btpy_insn_or_gap_new): Drop const.
(btpy_list_new): Take a thread pointer instead of a ptid_t. All
callers adjusted.
* python/py-record.c: Include "gdbthread.h".
(recpy_insn_new, recpy_func_new): Take a thread pointer instead of
a ptid_t. All callers adjusted.
(gdbpy_current_recording): Use inferior_thread.
* python/py-record.h (recpy_record_object) <ptid>: Delete
field, replaced with ...
<thread>: ... this new field. All users adjusted.
(recpy_element_object) <ptid>: Delete
field, replaced with ...
<thread>: ... this new field. All users adjusted.
(recpy_insn_new, recpy_func_new): Take a thread pointer instead of
a ptid_t. All callers adjusted.
* python/py-threadevent.c: Include "gdbthread.h".
(get_event_thread): Use thread_to_thread_object.
* python/python-internal.h (struct inferior_object): Forward
declare.
(find_thread_object, find_inferior_object): Delete declarations.
(thread_to_thread_object, inferior_to_inferior_object): New
declarations.
* record-btrace.c: Include "inferior.h".
(require_btrace_thread): Use inferior_thread.
(record_btrace_frame_sniffer)
(record_btrace_tailcall_frame_sniffer): Use inferior_thread.
(get_thread_current_frame): Use scoped_restore_current_thread and
switch_to_thread.
(get_thread_current_frame): Use thread pointer directly.
(record_btrace_replay_at_breakpoint): Use thread's inferior
pointer directly.
* record-full.c: Include "inferior.h".
* regcache.c: Include "gdbthread.h".
(get_thread_arch_regcache): Use the inferior's address space
directly.
(get_thread_regcache, registers_changed_thread): New.
* regcache.h (get_thread_regcache(thread_info *thread)): New
overload.
(registers_changed_thread): New.
(remote_target) <remote_detach_1>: Swap order of parameters.
(remote_add_thread): <remote_add_thread>: Return the new thread.
(get_remote_thread_info(ptid_t)): New overload.
(remote_target::remote_notice_new_inferior): Use thread pointers
directly.
(remote_target::process_initial_stop_replies): Use
thread_info::set_running.
(remote_target::remote_detach_1, remote_target::detach)
(extended_remote_target::detach): Adjust.
* stack.c (frame_show_address): Use inferior_thread.
* target-debug.h (target_debug_print_thread_info_pp): New.
* target-delegates.c: Regenerate.
* target.c (default_thread_address_space): Delete.
(memory_xfer_partial_1): Use current_inferior.
(target_detach): Use current_inferior.
(target_thread_address_space): Delete.
(generic_mourn_inferior): Use current_inferior.
* target.h (struct target_ops) <thread_address_space>: Delete.
(target_thread_address_space): Delete.
* thread.c (init_thread_list): Use ALL_THREADS_SAFE. Use thread
pointers directly.
(delete_thread_1, delete_thread, delete_thread_silent): Take a
thread pointer instead of a ptid_t. Adjust all callers.
(ptid_to_global_thread_id, global_thread_id_to_ptid): Delete.
(first_thread_of_process): Delete, replaced by ...
(first_thread_of_inferior): ... this new function. All callers
adjusted.
(any_thread_of_process): Rename to ...
(any_thread_of_inferior): ... this, and take an inferior pointer.
(any_live_thread_of_process): Rename to ...
(any_live_thread_of_inferior): ... this, and take an inferior
pointer.
(thread_stack_temporaries_enabled_p, push_thread_stack_temporary)
(value_in_thread_stack_temporaries)
(get_last_thread_stack_temporary): Take a thread pointer instead
of a ptid_t. Adjust all callers.
(thread_info::set_running): New.
(validate_registers_access): Use inferior_thread.
(can_access_registers_ptid): Rename to ...
(can_access_registers_thread): ... this, and take a thread
pointer.
(print_thread_info_1): Adjust to compare thread pointers instead
of ptids.
(switch_to_no_thread, switch_to_thread): Make extern.
(scoped_restore_current_thread::~scoped_restore_current_thread):
Use m_thread pointer directly.
(scoped_restore_current_thread::scoped_restore_current_thread):
Use inferior_thread.
(thread_command): Use thread pointer directly.
(thread_num_make_value_helper): Use inferior_thread.
* top.c (execute_command): Use inferior_thread.
* tui/tui-interp.c: Include "inferior.h".
* varobj.c (varobj_create): Use inferior_thread.
(value_of_root_1): Use find_thread_global_id instead of
global_thread_id_to_ptid.
This updates some help text in linux-fork.c to conform to GNU
standards.
2018-04-29 Tom Tromey <tom@tromey.com>
* linux-fork.c (_initialize_linux_fork): Update help text.
This patch adds a new class (type) for readonly regcache, which is
created via regcache::save. readonly_detached_regcache inherits
readable_regcache.
gdb:
2018-02-21 Yao Qi <yao.qi@linaro.org>
* dummy-frame.c (dummy_frame_cache) <prev_regcache>: Use
readonly_detached_regcache.
(dummy_frame_prev_register): Use regcache->cooked_read.
* frame.c (frame_save_as_regcache): Change return type.
(frame_pop): Update.
* frame.h (frame_save_as_regcache): Update declaration.
* inferior.h (get_infcall_suspend_state_regcache): Update
declaration.
* infrun.c (infcall_suspend_state) <registers>: use
readonly_detached_regcache.
(save_infcall_suspend_state): Don't use regcache_dup.
(get_infcall_suspend_state_regcache): Change return type.
* linux-fork.c (struct fork_info) <savedregs>: Change to
readonly_detached_regcache.
<pc>: New field.
(fork_save_infrun_state): Don't use regcache_dup.
(info_checkpoints_command): Adjust.
* mi/mi-main.c (register_changed_p): Update declaration.
(mi_cmd_data_list_changed_registers): Use
readonly_detached_regcache.
(register_changed_p): Change parameter type to
readonly_detached_regcache.
* ppc-linux-tdep.c (ppu2spu_cache) <regcache>: Use
readonly_detached_regcache.
(ppu2spu_sniffer): Construct a new readonly_detached_regcache.
* regcache.c (readonly_detached_regcache::readonly_detached_regcache):
New.
(regcache::save): Move it to reg_buffer.
(regcache::restore): Change parameter type.
(regcache_dup): Remove.
* regcache.h (reg_buffer) <save>: New method.
(readonly_detached_regcache): New class.
* spu-tdep.c (spu2ppu_cache) <regcache>: Use
readonly_detached_regcache.
(spu2ppu_sniffer): Construct a new readonly_detached_regcache.
... instead we start to use regcache methods save and restore. It is
quite straightforward to replace regcache_save with regcache->save.
regcache_cpy has some asserts, some of them not necessary, like
gdb_assert (src != dst);
because we already assert !m_readonly_p and src->m_readonly_p, so
src isn't dst. Some of the asserts are moved to ::restore.
gdb:
2018-02-21 Yao Qi <yao.qi@linaro.org>
* frame.c (frame_save_as_regcache): Use regcache method save.
(frame_pop): Use regcache method restore.
* infrun.c (restore_infcall_suspend_state): Likewise.
* linux-fork.c (fork_load_infrun_state): Likewise.
* ppc-linux-tdep.c (ppu2spu_sniffer): User regcache method
save.
* regcache.c (regcache_save): Remove.
(regcache::restore): More asserts.
(regcache_cpy): Remove.
* regcache.h (regcache_save): Remove the declaration.
(regcache::restore): Move from private to public.
Remove the friend declaration of regcache_cpy.
(regcache_cpy): Remove declaration.
I was looking into adding a parameter to target_detach, and was
wondering what the args parameter was. It seems like in the distant
past, it was possible to specify a signal number when detaching. That
signal was injected in the process before it was detached. There is an
example of code handling this in linux_nat_detach. With today's GDB, I
can't get this to work. Doing "detach 15" (15 == SIGTERM) doesn't work,
because detach is a prefix command and doesn't recognize the sub-command
15. Doing "detach inferiors 15" doesn't work because it expects a list
of inferior id to detach. Therefore, I don't think there's a way of
invoking detach_command with a non-NULL args. I also didn't find any
documentation related to this feature.
I assume that this feature stopped working when detach was made a prefix
command, which is in f73adfeb8b (sorry,
there's no commit title) from 2006. Given that this feature was broken
for such a long time and we haven't heard anything (AFAIK, I did not
find any related bug), I think it's safe to remove it, as well as the
args parameter to target_detach. If someone wants to re-introduce it, I
would suggest rethinking the user interface, and in particular would
suggest using signal name instead of numbers.
I tried to fix all the impacted code, but I might have forgotten some
spots. It shouldn't be hard to fix if that's the case. I also couldn't
build-test everything I changed, especially the nto and solaris stuff.
gdb/ChangeLog:
* target.h (struct target_ops) <to_detach>: Remove args
parameter.
(target_detach): Likewise.
* target.c (dispose_inferior): Adjust.
(target_detach): Remove args parameter, adjust.
* aix-thread.c (aix_thread_detach): Adjust.
* corefile.c (core_file_command): Adjust.
* corelow.c (core_detach): Adjust.
* darwin-nat.c (darwin_detach): Adjust.
* gnu-nat.c (gnu_detach): Adjust.
* inf-ptrace.c (inf_ptrace_detach): Adjust.
* infcmd.c (detach_command): Adjust
* infrun.c (follow_fork_inferior): Adjust.
(handle_vfork_child_exec_or_exit): Adjust.
* linux-fork.c (linux_fork_detach): Remove args parameter.
* linux-fork.h (linux_fork_detach): Likewise.
* linux-nat.c (linux_nat_detach): Likewise, and adjust.
* linux-thread-db.c (thread_db_detach): Likewise.
* nto-procfs.c (procfs_detach): Likewise.
* procfs.c (procfs_detach): Likewise.
(do_detach): Remove signo parameter.
* record.c (record_detach): Remove args parameter.
* record.h (record_detach): Likewise.
* remote-sim.c (gdbsim_detach): Likewise.
* remote.c (remote_detach_1): Likewise.
(remote_detach): Likewise.
(extended_remote_detach): Likewise.
* sol-thread.c (sol_thread_detach): Likewise.
* target-delegates.c: Re-generate.
* top.c (struct qt_args) <args>: Remove field.
(kill_or_detach): Don't pass args.
(quit_force): Don't set args.
* windows-nat.c (windows_detach): Remove args parameter.
The fact that GDB defaults to assuming that functions return int, when
it has no debug info for the function has been a recurring source of
user confusion. Recently this came up on the errno pretty printer
discussions. Shortly after, it came up again on IRC, with someone
wondering why does getenv() in GDB return a negative int:
(gdb) p getenv("PATH")
$1 = -6185
This question (with s/getenv/random-other-C-runtime-function) is a FAQ
on IRC.
The reason for the above is:
(gdb) p getenv
$2 = {<text variable, no debug info>} 0x7ffff7751d80 <getenv>
(gdb) ptype getenv
type = int ()
... which means that GDB truncated the 64-bit pointer that is actually
returned from getent to 32-bit, and then sign-extended it:
(gdb) p /x -6185
$6 = 0xffffe7d7
The workaround is to cast the function to the right type, like:
(gdb) p ((char *(*) (const char *)) getenv) ("PATH")
$3 = 0x7fffffffe7d7 "/usr/local/bin:/"...
IMO, we should do better than this.
I see the "assume-int" issue the same way I see printing bogus values
for optimized-out variables instead of "<optimized out>" -- I'd much
rather that the debugger tells me "I don't know" and tells me how to
fix it than showing me bogus misleading results, making me go around
tilting at windmills.
If GDB prints a signed integer when you're expecting a pointer or
aggregate, you at least have some sense that something is off, but
consider the case of the function actually returning a 64-bit integer.
For example, compile this without debug info:
unsigned long long
function ()
{
return 0x7fffffffffffffff;
}
Currently, with pristine GDB, you get:
(gdb) p function ()
$1 = -1 # incorrect
(gdb) p /x function ()
$2 = 0xffffffff # incorrect
maybe after spending a few hours debugging you suspect something is
wrong with that -1, and do:
(gdb) ptype function
type = int ()
and maybe, just maybe, you realize that the function actually returns
unsigned long long. And you try to fix it with:
(gdb) p /x (unsigned long long) function ()
$3 = 0xffffffffffffffff # incorrect
... which still produces the wrong result, because GDB simply applied
int to unsigned long long conversion. Meaning, it sign-extended the
integer that it extracted from the return of the function, to 64-bits.
and then maybe, after asking around on IRC, you realize you have to
cast the function to a pointer of the right type, and call that. It
won't be easy, but after a few missteps, you'll get to it:
..... (gdb) p /x ((unsigned long long(*) ()) function) ()
$666 = 0x7fffffffffffffff # finally! :-)
So to improve on the user experience, this patch does the following
(interrelated) things:
- makes no-debug-info functions no longer default to "int" as return
type. Instead, they're left with NULL/"<unknown return type>"
return type.
(gdb) ptype getenv
type = <unknown return type> ()
- makes calling a function with unknown return type an error.
(gdb) p getenv ("PATH")
'getenv' has unknown return type; cast the call to its declared return type
- and then to make it easier to call the function, makes it possible
to _only_ cast the return of the function to the right type,
instead of having to cast the function to a function pointer:
(gdb) p (char *) getenv ("PATH") # now Just Works
$3 = 0x7fffffffe7d7 "/usr/local/bin:/"...
(gdb) p ((char *(*) (const char *)) getenv) ("PATH") # continues working
$4 = 0x7fffffffe7d7 "/usr/local/bin:/"...
I.e., it makes GDB default the function's return type to the type
of the cast, and the function's parameters to the type of the
arguments passed down.
After this patch, here's what you'll get for the "unsigned long long"
example above:
(gdb) p function ()
'function' has unknown return type; cast the call to its declared return type
(gdb) p /x (unsigned long long) function ()
$4 = 0x7fffffffffffffff # correct!
Note that while with "print" GDB shows the name of the function that
has the problem:
(gdb) p getenv ("PATH")
'getenv' has unknown return type; cast the call to its declared return type
which can by handy in more complicated expressions, "ptype" does not:
(gdb) ptype getenv ("PATH")
function has unknown return type; cast the call to its declared return type
This will be fixed in the next patch.
gdb/ChangeLog:
2017-09-04 Pedro Alves <palves@redhat.com>
* ada-lang.c (ada_evaluate_subexp) <TYPE_CODE_FUNC>: Don't handle
TYPE_GNU_IFUNC specially here. Throw error if return type is
unknown.
* ada-typeprint.c (print_func_type): Handle functions with unknown
return type.
* c-typeprint.c (c_type_print_base): Handle functions and methods
with unknown return type.
* compile/compile-c-symbols.c (convert_symbol_bmsym)
<mst_text_gnu_ifunc>: Use nodebug_text_gnu_ifunc_symbol.
* compile/compile-c-types.c: Include "objfiles.h".
(convert_func): For functions with unknown return type, warn and
default to int.
* compile/compile-object-run.c (compile_object_run): Adjust call
to call_function_by_hand_dummy.
* elfread.c (elf_gnu_ifunc_resolve_addr): Adjust call to
call_function_by_hand.
* eval.c (evaluate_subexp_standard): Adjust calls to
call_function_by_hand. Handle functions and methods with unknown
return type. Pass expect_type to call_function_by_hand.
* f-typeprint.c (f_type_print_base): Handle functions with unknown
return type.
* gcore.c (call_target_sbrk): Adjust call to
call_function_by_hand.
* gdbtypes.c (objfile_type): Leave nodebug text symbol with NULL
return type instead of int. Make nodebug_text_gnu_ifunc_symbol be
an integer address type instead of nodebug.
* guile/scm-value.c (gdbscm_value_call): Adjust call to
call_function_by_hand.
* infcall.c (error_call_unknown_return_type): New function.
(call_function_by_hand): New "default_return_type" parameter.
Pass it down.
(call_function_by_hand_dummy): New "default_return_type"
parameter. Use it instead of defaulting to int. If there's no
default and the return type is unknown, throw an error. If
there's a default return type, and the called function has no
debug info, then assume the function is prototyped.
* infcall.h (call_function_by_hand, call_function_by_hand_dummy):
New "default_return_type" parameter.
(error_call_unknown_return_type): New declaration.
* linux-fork.c (call_lseek): Cast return type of lseek.
(inferior_call_waitpid, checkpoint_command): Adjust calls to
call_function_by_hand.
* linux-tdep.c (linux_infcall_mmap, linux_infcall_munmap): Adjust
calls to call_function_by_hand.
* m2-typeprint.c (m2_procedure): Handle functions with unknown
return type.
* objc-lang.c (lookup_objc_class, lookup_child_selector)
(value_nsstring, print_object_command): Adjust calls to
call_function_by_hand.
* p-typeprint.c (pascal_type_print_varspec_prefix): Handle
functions with unknown return type.
(pascal_type_print_func_varspec_suffix): New function.
(pascal_type_print_varspec_suffix) <TYPE_CODE_FUNC,
TYPE_CODE_METHOD>: Use it.
* python/py-value.c (valpy_call): Adjust call to
call_function_by_hand.
* rust-lang.c (rust_evaluate_funcall): Adjust call to
call_function_by_hand.
* valarith.c (value_x_binop, value_x_unop): Adjust calls to
call_function_by_hand.
* valops.c (value_allocate_space_in_inferior): Adjust call to
call_function_by_hand.
* typeprint.c (type_print_unknown_return_type): New function.
* typeprint.h (type_print_unknown_return_type): New declaration.
gdb/testsuite/ChangeLog:
2017-09-04 Pedro Alves <palves@redhat.com>
* gdb.base/break-main-file-remove-fail.exp (test_remove_bp): Cast
return type of munmap in infcall.
* gdb.base/break-probes.exp: Cast return type of foo in infcall.
* gdb.base/checkpoint.exp: Simplify using for loop. Cast return
type of ftell in infcall.
* gdb.base/dprintf-detach.exp (dprintf_detach_test): Cast return
type of getpid in infcall.
* gdb.base/infcall-exec.exp: Cast return type of execlp in
infcall.
* gdb.base/info-os.exp: Cast return type of getpid in infcall.
Bail on failure to extract the pid.
* gdb.base/nodebug.c: #include <stdint.h>.
(multf, multf_noproto, mult, mult_noproto, add8, add8_noproto):
New functions.
* gdb.base/nodebug.exp (test_call_promotion): New procedure.
Change expected output of print/whatis/ptype with functions with
no debug info. Test all supported languages. Call
test_call_promotion.
* gdb.compile/compile.exp: Adjust expected output to expect
warning.
* gdb.threads/siginfo-threads.exp: Likewise.
This applies the second part of GDB's End of Year Procedure, which
updates the copyright year range in all of GDB's files.
gdb/ChangeLog:
Update copyright year range in all GDB files.
This patch replaces many (but not all) uses of
make_cleanup_restore_integer with a simple RAII-based template class.
It also removes the similar restore_execution_direction cleanup in
favor of this new class. Subsequent patches will replace other
similar cleanups with this class.
The class is typically instantiated using make_scoped_restore. This
allows for template argument deduction.
2016-10-21 Tom Tromey <tom@tromey.com>
* common/scoped_restore.h: New file.
* utils.h: Include scoped_restore.h.
* top.c (execute_command_to_string): Use scoped_restore.
* python/python.c (python_interactive_command): Use
scoped_restore.
(python_command, execute_gdb_command): Likewise.
* printcmd.c (do_one_display): Use scoped_restore.
* mi/mi-main.c (exec_continue): Use scoped_restore.
* mi/mi-cmd-var.c (mi_cmd_var_assign): Use scoped_restore.
* linux-fork.c (checkpoint_command): Use scoped_restore.
* infrun.c (restore_execution_direction): Remove.
(fetch_inferior_event): Use scoped_restore.
* compile/compile.c (compile_file_command): Use
scoped_restore.
(compile_code_command, compile_print_command): Likewise.
* cli/cli-script.c (execute_user_command): Use
scoped_restore.
(while_command, if_command, script_from_file): Likewise.
* arm-tdep.c (arm_insert_single_step_breakpoint): Use
scoped_restore.
Before:
(gdb) info checkpoints
3 process 29132 at 0x4008ad, file foo.c, line 81
2 process 29131 at 0x4008ad, file foo.c, line 81
1 process 29130 at 0x4008ad, file foo.c, line 81
* 0 Thread 0x7ffff7fc5740 (LWP 29128) (main process) at 0x4008ad, file foo.c, line 81
After:
(gdb) info checkpoints
* 0 Thread 0x7ffff7fc5740 (LWP 29128) (main process) at 0x4008ad, file foo.c, line 81
1 process 29130 at 0x4008ad, file foo.c, line 81
2 process 29131 at 0x4008ad, file foo.c, line 81
3 process 29132 at 0x4008ad, file foo.c, line 81
gdb/ChangeLog:
2015-11-24 Pedro Alves <palves@redhat.com>
PR 17539
* printcmd.c (display_command): Append new display at the end of
the list.
gdb/testsuite/ChangeLog:
2015-11-24 Pedro Alves <palves@redhat.com>
PR 17539
* gdb.base/display.exp: Expect displays to be sorted in ascending
order. Use multi_line.
* gdb.base/solib-display.exp: Likewise.
This way the user can know the index of the latest checkpoint without
having to run "info checkpoints" afterwards.
gdb/ChangeLog:
* linux-fork.c (checkpoint_command): Print index of new
checkpoint in response message.