This patch adds documentation of support for exec events on
extended-remote Linux targets.
gdb/ChangeLog:
* NEWS: Announce new remote packets for the exec-events
feature and the exec-events feature and associated commands.
gdb/doc/ChangeLog:
* gdb.texinfo (Remote Configuration): Add exec event
feature to table of packet settings.
(Stop Reply Packets): Add exec events to the list of stop
reasons.
(General Query Packets): Add exec events to tables of
'gdbfeatures' and 'stub features' supported in the qSupported
packet, as well as to the list containing stub feature
details.
This patch implements exec catchpoints for extended-remote Linux
targets. The implementation follows the same approach used for
fork catchpoints, implementing extended-remote target routines for
inserting and removing the catchpoints by just checking if exec events
are supported. Existing host-side code and previous support for
extended-remote exec events takes care of the rest.
gdb/ChangeLog:
* remote.c (remote_exec_event_p): New function.
(remote_insert_exec_catchpoint): New function.
(remote_remove_exec_catchpoint): New function.
(init_extended_remote_ops): Initialize extended_remote_ops
members to_insert_exec_catchpoint and
to_remove_exec_catchpoint.
This patch implements support for exec events on extended-remote Linux
targets. Follow-exec-mode and rerun behave as expected. Catchpoints and
test updates are implemented in subsequent patches.
This patch was derived from a patch posted last October:
https://sourceware.org/ml/gdb-patches/2014-10/msg00877.html.
It was originally based on some work done by Luis Machado in 2013.
IMPLEMENTATION
----------------
Exec events are enabled via ptrace options.
When an exec event is detected by gdbserver, the existing process
data, along with all its associated lwp and thread data, is deleted
and replaced by data for a new single-threaded process. The new
process data is initialized with the appropriate parts of the state
of the execing process. This approach takes care of several potential
pitfalls, including:
* deleting the data for an execing non-leader thread before any
wait/sigsuspend occurs
* correctly initializing the architecture of the execed process
We then report the exec event using a new RSP stop reason, "exec".
When GDB receives an "exec" event, it saves the status in the event
structure's target_waitstatus field, like what is done for remote fork
events. Because the original and execed programs may have different
architectures, we skip parsing the section of the stop reply packet
that contains register data. The register data will be retrieved
later after the inferior's architecture has been set up by
infrun.c:follow_exec.
At that point the exec event is handled by the existing event handling
in GDB. However, a few changes were necessary so that
infrun.c:follow_exec could accommodate the remote target.
* Where follow-exec-mode "new" is handled, we now call
add_inferior_with_spaces instead of add_inferior with separate calls
to set up the program and address spaces. The motivation for this
is that add_inferior_with_spaces also sets up the initial architecture
for the inferior, which is needed later by target_find_description
when it calls target_gdbarch.
* We call a new target function, target_follow_exec. This function
allows us to store the execd_pathname in the inferior, instead of
using the static string remote_exec_file from remote.c. The static
string didn't work for follow-exec-mode "new", since once you switched
to the execed program, the original remote exec-file was lost. The
execd_pathname is now stored in the inferior's program space as a
REGISTRY field. All of the requisite mechanisms for this are
defined in remote.c.
gdb/gdbserver/ChangeLog:
* linux-low.c (linux_mourn): Static declaration.
(linux_arch_setup): Move in front of
handle_extended_wait.
(linux_arch_setup_thread): New function.
(handle_extended_wait): Handle exec events. Call
linux_arch_setup_thread. Make event_lwp argument a
pointer-to-a-pointer.
(check_zombie_leaders): Do not check stopped threads.
(linux_low_ptrace_options): Add PTRACE_O_TRACEEXEC.
(linux_low_filter_event): Add lwp and thread for exec'ing
non-leader thread if leader thread has been deleted.
Refactor code into linux_arch_setup_thread and call it.
Pass child lwp pointer by reference to handle_extended_wait.
(linux_wait_for_event_filtered): Update comment.
(linux_wait_1): Prevent clobbering exec event status.
(linux_supports_exec_events): New function.
(linux_target_ops) <supports_exec_events>: Initialize new member.
* lynx-low.c (lynx_target_ops) <supports_exec_events>: Initialize
new member.
* remote-utils.c (prepare_resume_reply): New stop reason 'exec'.
* server.c (report_exec_events): New global variable.
(handle_query): Handle qSupported query for exec-events feature.
(captured_main): Initialize report_exec_events.
* server.h (report_exec_events): Declare new global variable.
* target.h (struct target_ops) <supports_exec_events>: New
member.
(target_supports_exec_events): New macro.
* win32-low.c (win32_target_ops) <supports_exec_events>:
Initialize new member.
gdb/ChangeLog:
* infrun.c (follow_exec): Use process-style ptid for
exec message. Call add_inferior_with_spaces and
target_follow_exec.
* nat/linux-ptrace.c (linux_supports_traceexec): New function.
* nat/linux-ptrace.h (linux_supports_traceexec): Declare.
* remote.c (remote_pspace_data): New static variable.
(remote_pspace_data_cleanup): New function.
(get_remote_exec_file): New function.
(set_remote_exec_file_1): New function.
(set_remote_exec_file): New function.
(show_remote_exec_file): New function.
(remote_exec_file): Delete static variable.
(anonymous enum) <PACKET_exec_event_feature> New
enumeration constant.
(remote_protocol_features): Add entry for exec-events feature.
(remote_query_supported): Add client side of qSupported query
for exec-events feature.
(remote_follow_exec): New function.
(remote_parse_stop_reply): Handle 'exec' stop reason.
(extended_remote_run, extended_remote_create_inferior): Call
get_remote_exec_file and set_remote_exec_file_1.
(init_extended_remote_ops) <to_follow_exec>: Initialize new
member.
(_initialize_remote): Call
register_program_space_data_with_cleanup. Call
add_packet_config_cmd for remote exec-events feature.
Modify call to add_setshow_string_noescape_cmd for exec-file
to use new functions set_remote_exec_file and
show_remote_exec_file.
* target-debug.h, target-delegates.c: Regenerated.
* target.c (target_follow_exec): New function.
* target.h (struct target_ops) <to_follow_exec>: New member.
(target_follow_exec): Declare new function.
gdb/ChangeLog:
* aarch64-tdep.c (decode_cb): Move up comment describing the
encoding.
(decode_tb): Fix a typo in comment above the function. Move up
comment describing the encoding.
The encoding of the b.cond instruction is described in the architecture
reference manual as:
b.cond 0101 0100 iiii iiii iiii iiii iii0 cccc
So the mask should be 0xff000010.
gdb/ChangeLog:
* aarch64-tdep.c (decode_bcond): Fix incorrect mask.
I found this const/not const mixup found by building in C++ mode.
gdb/ChangeLog:
* ada-lang.c (ada_search_struct_field): Constify parameters
and/or variables..
(xget_renaming_scope): Likewise.
(ada_is_redundant_range_encoding): Likewise.
(scan_discrim_bound): Likewise.
(to_fixed_range_type): Likewise.
Nowadays, GDB calls target_can_download_tracepoint at the entry of
download_tracepoint_locations, which is called by.
update_global_location_list. Sometimes, it is not needed to call
target_can_download_tracepoint at all because there is no tracepoint
created. In remote target, target_can_download_tracepoint send
qTStatus to the remote in order to know whether tracepoint can be
downloaded or not. This means some redundant qTStatus packets are
sent.
This patch is to teach GDB to call target_can_download_tracepoint
lazily, only on the moment there are tracepoint to download.
gdb.perf/single-step.exp (with a local patch to measure RSP packets)
shows the number of RSP packets is reduced because there is no
tracepoint at all, so GDB doesn't send qTStatus any more.
# of RSP packets
original patched
single-step rsp 1000 7000 6000
single-step rsp 2000 14000 12000
single-step rsp 3000 21000 18000
single-step rsp 4000 28000 24000
gdb:
2015-09-10 Yao Qi <yao.qi@linaro.org>
* breakpoint.c (download_tracepoint_locations): New local
can_download_tracepoint. Check the result of
target_can_download_tracepoint and save it in
can_download_tracepoint if there are tracepoints to download.
* linux-nat.h (enum tribool): Move it to ...
* common/common-types.h: ... here.
gdb/ChangeLog:
2015-09-09 Pedro Alves <palves@redhat.com>
* breakpoint.c: Include "thread-fsm.h".
(struct until_break_command_continuation_args): Delete.
(struct until_break_fsm): New.
(until_break_fsm_ops): New global.
(new_until_break_fsm, until_break_fsm_should_stop): New functions.
(until_break_command_continuation): Delete.
(until_break_fsm_clean_up): New function.
(until_break_fsm_async_reply_reason): New function.
(until_break_command): Adjust to create an until_break_fsm instead
of a continuation.
(momentary_bkpt_print_it): No longer print MI's async-stop-reason
here.
* infcmd.c (struct until_next_fsm): New.
(until_next_fsm_ops): New global.
(new_until_next_fsm, until_next_fsm_should_stop): New function.
(until_next_continuation): Delete.
(until_next_fsm_clean_up, until_next_fsm_async_reply_reason): New
functions.
(until_next_command): Adjust to create a new until_next_fsm
instead of a continuation.
This removes infcall-specific special casing from normal_stop,
simplifying it.
Like the "finish" command's, the FSM is responsible for storing the
function's return value.
gdb/ChangeLog:
2015-09-09 Pedro Alves <palves@redhat.com>
* infcall.c: Include thread_fsm.h.
(struct call_return_meta_info): New.
(get_call_return_value): New function, factored out from
call_function_by_hand_dummy.
(struct call_thread_fsm): New.
(call_thread_fsm_ops): New global.
(new_call_thread_fsm, call_thread_fsm_should_stop)
(call_thread_fsm_should_notify_stop): New functions.
(run_inferior_call): Add 'sm' parameter. Associate the FSM with
the thread.
(call_function_by_hand_dummy): Create a new call_thread_fsm
instance, associate it with the thread, and wait for the FSM to
finish. If finished successfully, fetch the function's result
value out of the FSM.
* infrun.c (fetch_inferior_event): If the FSM says the stop
shouldn't be notified, don't call normal_stop.
(maybe_remove_breakpoints): New function, factored out from ...
(normal_stop): ... here. Simplify.
* infrun.h (maybe_remove_breakpoints): Declare.
* thread-fsm.c (thread_fsm_should_notify_stop): New function.
(thread-fsm.h) <struct thread_fsm_ops>: New field.
(thread_fsm_should_notify_stop): Declare.
This adds an object oriented replacement for the "struct continuation"
mechanism, and converts the stepping commands (step, next, stepi,
nexti) and the "finish" commands to use it.
It adds a new thread "class" (struct thread_fsm) that contains the
necessary info and callbacks to manage the state machine of a thread's
execution command.
This allows getting rid of some hacks. E.g., in fetch_inferior_event
and normal_stop we no longer need to know whether a thread is doing a
multi-step (e.g., step N). This effectively makes the
intermediate_continuations unused -- they'll be garbage collected in a
separate patch. (They were never a proper abstraction, IMO. See how
fetch_inferior_event needs to check step_multi before knowing whether
to call INF_EXEC_CONTINUE or INF_EXEC_COMPLETE.)
The target async vs !async uiout hacks in mi_on_normal_stop go away
too.
print_stop_event is no longer called from normal_stop. Instead it is
now called from within each interpreter's normal_stop observer. This
clears the path to make each interpreter print a stop event the way it
sees fit. Currently we have some hacks in common code to
differenciate CLI vs TUI vs MI around this area.
The "finish" command's FSM class stores the return value plus that
value's position in the value history, so that those can be printed to
both MI and CLI's streams. This fixes the CLI "finish" command when
run from MI -- it now also includes the function's return value in the
CLI stream:
(gdb)
~"callee3 (strarg=0x400730 \"A string argument.\") at src/gdb/testsuite/gdb.mi/basics.c:35\n"
~"35\t}\n"
+~"Value returned is $1 = 0\n"
*stopped,reason="function-finished",frame=...,gdb-result-var="$1",return-value="0",thread-id="1",stopped-threads="all",core="0"
-FAIL: gdb.mi/mi-cli.exp: CLI finish: check CLI output
+PASS: gdb.mi/mi-cli.exp: CLI finish: check CLI output
gdb/ChangeLog:
2015-09-09 Pedro Alves <palves@redhat.com>
* Makefile.in (COMMON_OBS): Add thread-fsm.o.
* breakpoint.c (handle_jit_event): Print debug output.
(bpstat_what): Split event callback handling to ...
(bpstat_run_callbacks): ... this new function.
(momentary_bkpt_print_it): No longer handle bp_finish here.
* breakpoint.h (bpstat_run_callbacks): Declare.
* gdbthread.h (struct thread_info) <step_multi>: Delete field.
<thread_fsm>: New field.
(thread_cancel_execution_command): Declare.
* infcmd.c: Include thread-fsm.h.
(struct step_command_fsm): New.
(step_command_fsm_ops): New global.
(new_step_command_fsm, step_command_fsm_prepare): New functions.
(step_1): Adjust to use step_command_fsm_prepare and
prepare_one_step.
(struct step_1_continuation_args): Delete.
(step_1_continuation): Delete.
(step_command_fsm_should_stop): New function.
(step_once): Delete.
(step_command_fsm_clean_up, step_command_fsm_async_reply_reason)
(prepare_one_step): New function, based on step_once.
(until_next_command): Remove step_multi reference.
(struct return_value_info): New.
(print_return_value): Rename to ...
(print_return_value_1): ... this. New struct return_value_info
parameter. Adjust.
(print_return_value): Reimplement as wrapper around
print_return_value_1.
(struct finish_command_fsm): New.
(finish_command_continuation): Delete.
(finish_command_fsm_ops): New global.
(new_finish_command_fsm, finish_command_fsm_should_stop): New
functions.
(finish_command_fsm_clean_up, finish_command_fsm_return_value):
New.
(finish_command_continuation_free_arg): Delete.
(finish_command_fsm_async_reply_reason): New.
(finish_backward, finish_forward): Change symbol parameter to a
finish_command_fsm. Adjust.
(finish_command): Create a finish_command_fsm. Adjust.
* infrun.c: Include "thread-fsm.h".
(clear_proceed_status_thread): Delete the thread's FSM.
(infrun_thread_stop_requested_callback): Cancel the thread's
execution command.
(clean_up_just_stopped_threads_fsms): New function.
(fetch_inferior_event): Handle the event_thread's should_stop
method saying the command isn't done yet.
(process_event_stop_test): Run breakpoint callbacks here.
(print_stop_event): Rename to ...
(print_stop_location): ... this.
(restore_current_uiout_cleanup): New function.
(print_stop_event): Reimplement.
(normal_stop): No longer notify the end_stepping_range observers
here handle "step N" nor "finish" here. No longer call
print_stop_event here.
* infrun.h (struct return_value_info): Forward declare.
(print_return_value): Declare.
(print_stop_event): Change prototype.
* thread-fsm.c: New file.
* thread-fsm.h: New file.
* thread.c: Include "thread-fsm.h".
(thread_cancel_execution_command): New function.
(clear_thread_inferior_resources): Call it.
* cli/cli-interp.c (cli_on_normal_stop): New function.
(cli_interpreter_init): Install cli_on_normal_stop as normal_stop
observer.
* mi/mi-interp.c: Include "thread-fsm.h".
(restore_current_uiout_cleanup): Delete.
(mi_on_normal_stop): If the thread has an FSM associated, and it
finished, ask it for the async-reply-reason to print. Always call
print_stop_event here, regardless of the top-level interpreter.
Check bpstat_what to tell whether an asynchronous breakpoint hit
triggered.
* tui/tui-interp.c (tui_on_normal_stop): New function.
(tui_init): Install tui_on_normal_stop as normal_stop observer.
gdb/testsuite/ChangeLog:
2015-09-09 Pedro Alves <palves@redhat.com>
* gdb.mi/mi-cli.exp: Add CLI finish tests.
This patch makes the execution control code use largely the same
mechanisms in both sync- and async-capable targets. This means using
continuations and use the event loop to react to target events on sync
targets as well. The trick is to immediately mark infrun's event loop
source after resume instead of calling wait_for_inferior. Then
fetch_inferior_event is adjusted to do a blocking wait on sync
targets.
Tested on x86_64 Fedora 20, native and gdbserver, with and without
"maint set target-async off".
gdb/ChangeLog:
2015-09-09 Pedro Alves <palves@redhat.com>
* breakpoint.c (bpstat_do_actions_1, until_break_command): Don't
check whether the target can async.
* inf-loop.c (inferior_event_handler): Only call target_async if
the target can async.
* infcall.c: Include top.h and interps.h.
(run_inferior_call): For the interpreter to sync mode while
running the infcall. Call wait_sync_command_done instead of
wait_for_inferior plus normal_stop.
* infcmd.c (prepare_execution_command): Don't check whether the
target can async when running in the foreground.
(step_1): Delete synchronous case handling.
(step_once): Always install a continuation, even in sync mode.
(until_next_command, finish_forward): Don't check whether the
target can async.
(attach_command_post_wait, notice_new_inferior): Always install a
continuation, even in sync mode.
* infrun.c (mark_infrun_async_event_handler): New function.
(proceed): In sync mode, mark infrun's event source instead of
waiting for events here.
(fetch_inferior_event): If the target can't async, do a blocking
wait.
(prepare_to_wait): In sync mode, mark infrun's event source.
(infrun_async_inferior_event_handler): No longer bail out if the
target can't async.
* infrun.h (mark_infrun_async_event_handler): New declaration.
* linux-nat.c (linux_nat_wait_1): Remove calls to
set_sigint_trap/clear_sigint_trap.
(linux_nat_terminal_inferior): No longer check whether the target
can async.
* mi/mi-interp.c (mi_on_sync_execution_done): Update and simplify
comment.
(mi_execute_command_input_handler): No longer check whether the
target is async. Update and simplify comment.
* target.c (default_target_wait): New function.
* target.h (struct target_ops) <to_wait>: Now defaults to
default_target_wait.
(default_target_wait): Declare.
* top.c (wait_sync_command_done): New function, factored out from
...
(maybe_wait_sync_command_done): ... this.
* top.h (wait_sync_command_done): Declare.
* target-delegates.c: Regenerate.
For the BTS recording format, we sometimes get a FROM->TO record where the
FROM address lies in the kernel and the TO address lies in user space at
whatever address the user process was resumed.
GDB has a heuristic to filter out such records based on looking at the most
significant bit in the PC. This works fine for 64-bit systems but it doesn't
always work for 32-bit systems. Libraries that are loaded at fairly high
addresses might be mistaken for kernel code and branches inside the library
are filtered out.
Change the heuristic to (again heuristically) try to determine the lowest
address in kernel space. Any PC that is smaller than that should be in
user space.
On today's systems, there should be a symbol "_text" at that address.
Read /proc/kallsyms and search for that symbol.
It is not guaranteed that /proc/kallsyms is readable on all systems. On
64-bit systems, we fall back to check the most significant bit. On 32-bit
systems, we refrain from filtering out addresses.
The filtering should really be done by the kernel. And it soon will be:
https://lkml.org/lkml/2015/8/31/212.
gdb/
* nat/linux-btrace.h (struct btrace_target_info) <ptr_bits>: Remove.
* nat/linux-btrace.c: Include filestuff.h and inttypes.h.
Remove include of sys/utsname.h.
(linux_determine_kernel_ptr_bits): Remove.
(linux_determine_kernel_start): New.
(perf_event_is_kernel_addr): Remove tinfo argument. Update users.
Update check.
(perf_event_skip_bts_record): Remove tinfo argument. Update users.
(linux_enable_bts, linux_enable_pt): Remove tinfo->ptr_bits
initialization.
* x86-linux-nat.c (x86_linux_enable_btrace): Remove ptr_bits
assignment.
gdbserver/
* linux-low.c (linux_low_enable_btrace): Remove.
(linux_target_ops): Replace linux_low_enable_btrace with
linux_enable_btrace.
Building GDB in C++ mode on Fedora 20, the gdb/guile/ code shows ~280
errors like:
src/gdb/guile/guile.c:515:1: error: invalid conversion from ‘scm_unused_struct* (*)(SCM, SCM) {aka scm_unused_struct* (*)(scm_unused_struct*, scm_unused_struct*)}’ to ‘scm_t_subr {aka void*}’ [-fpermissive]
This commit fixes them all.
gdb/ChangeLog:
2015-09-07 Pedro Alves <palves@redhat.com>
* guile/guile-internal.h (as_a_scm_t_subr): New.
* guile/guile.c (misc_guile_functions): Use it.
* guile/scm-arch.c (arch_functions): Use it.
* guile/scm-block.c (block_functions, gdbscm_initialize_blocks):
Use it.
* guile/scm-breakpoint.c (breakpoint_functions): Use it.
* guile/scm-cmd.c (command_functions): Use it.
* guile/scm-disasm.c (disasm_functions): Use it.
* guile/scm-exception.c (exception_functions)
(private_exception_functions): Use it.
* guile/scm-frame.c (frame_functions)
* guile/scm-gsmob.c (gsmob_functions): Use it.
* guile/scm-iterator.c (iterator_functions): Use it.
* guile/scm-lazy-string.c (lazy_string_functions): Use it.
* guile/scm-math.c (math_functions): Use it.
* guile/scm-objfile.c (objfile_functions): Use it.
* guile/scm-param.c (parameter_functions): Use it.
* guile/scm-ports.c (port_functions, private_port_functions): Use
it.
* guile/scm-pretty-print.c (pretty_printer_functions): Use it.
* guile/scm-progspace.c (pspace_functions): Use it.
* guile/scm-string.c (string_functions): Use it.
* guile/scm-symbol.c (symbol_functions): Use it.
* guile/scm-symtab.c (symtab_functions): Use it.
* guile/scm-type.c (type_functions, gdbscm_initialize_types): Use
it.
* guile/scm-value.c (value_functions): Use it.
In the following code:
struct symbol *wsym = (struct symbol *) NULL;
the cast of NULL is redundant, it adds noise, and is just one more thing
to change if the type of wsym ever changes. There are a relatively
small number of places in gdb where the above code pattern is used.
Usually the cast is removed like this:
struct symbol *wsym = NULL;
This commit updates all the places within the gdb/tui directory where we
cast NULL during assignment, removing the cast.
gdb/ChangeLog:
* tui/tui-data.c (win_with_focus): Remove cast of NULL pointer.
(tui_next_win): Likewise.
(tui_prev_win): Likewise.
(tui_partial_win_by_name): Likewise.
(tui_init_generic_part): Likewise.
(init_content_element): Likewise.
(tui_del_window): Likewise.
(tui_free_window): Likewise.
(tui_del_data_windows): Likewise.
(tui_free_data_content): Likewise.
* tui/tui-layout.c (make_source_or_disasm_window): Likewise.
* tui/tui-regs.c (tui_show_register_group): Likewise.
* tui/tui-win.c (tui_resize_all): Likewise.
(tui_set_focus): Likewise.
(tui_set_win_height): Likewise.
(make_invisible_and_set_new_height): Likewise.
* tui/tui-windata.c (tui_delete_data_content_windows): Likewise.
* tui/tui-wingeneral.c (make_visible): Likewise.
In the following code:
struct symbol *wsym = (struct symbol *) NULL;
the cast of NULL is redundant, it adds noise, and is just one more thing
to change if the type of wsym ever changes. There are a relatively
small number of places in gdb where the above code pattern is used.
Usually the cast is removed like this:
struct symbol *wsym = NULL;
This commit updates all the places within the gdb/cli directory where we
cast NULL during assignment, removing the cast.
gdb/ChangeLog:
* cli/cli-decode.c (find_cmd): Remove cast of NULL pointer.
In the following code:
struct symbol *wsym = (struct symbol *) NULL;
the cast of NULL is redundant, it adds noise, and is just one more thing
to change if the type of wsym ever changes. There are a relatively
small number of places in gdb where the above code pattern is used.
Usually the cast is removed like this:
struct symbol *wsym = NULL;
This commit updates all the places within the gdb/ directory where we
cast NULL during assignment, removing the cast.
gdb/ChangeLog:
* c-valprint.c (print_unpacked_pointer): Remove cast of NULL
pointer.
* dbxread.c (dbx_end_psymtab): Likewise.
* gnu-nat.c (gnu_write_inferior): Likewise.
* mdebugread.c (cross_ref): Likewise.
* p-valprint.c (pascal_val_print): Likewise.
* xcoffread.c (xcoff_end_psymtab): Likewise.
Before this change, trying to call an overloaded function with at least
one character literal in argument would fail. For instance, given these
two functions:
function F (C : Character) return Integer is
begin
return Character'Pos (C);
end F;
function F (I : Integer) return Integer is
begin
return -I;
end F;
We would get the following GDB session:
(gdb) p f('A')
$1 = -65
(gdb) p f(1)
$1 = -1
This is wrong because the first call should select the first F function
and thus return 65.
The root problem is that ada-lang.c:ada_language_arch_info stores in
string_char_type a type whose code is TYPE_CODE_INT instead of
TYPE_CODE_CHAR. As a result, all parsed character literals are turned
into integer values and during overload matching, the TYPE_CODE_CHAR
formal rejects the TYPE_CODE_INT actual.
This change turns string_char_type into a true TYPE_CODE_CHAR type in
ada-lang.c so that we have instead the expected:
(gdb) p f('A')
$1 = 65
gdb/ChangeLog:
* ada-lang.c (ada_language_arch_info): Create a TYPE_CODE_CHAR
type instead of a TYPE_CODE_INT one for the string_char_type
and the ada_primitive_type_char types.
gdb/testsuite/ChangeLog:
* gdb.ada/funcall_char.exp: New testcase.
* gdb.ada/funcall_char/foo.adb: New file.
Tested on x86_64-linux, no regression.
Nowadays, if user requests HW watchpoint to monitor a large memory area
or unaligned area, aarch64 GDB will split into multiple aligned areas,
and use multiple debugging registers to watch them. However, the
registers are not updated in a transaction way. GDBserver doesn't revert
updates in previous iterations if some debugging registers fail to update
due to some reason, like no free debugging registers available, in the
latter iteration. For example, if we have a char buf[34], and watch buf
in gdb,
(gdb) watch buf
Hardware watchpoint 2: buf
(gdb) c
Continuing.
infrun: clear_proceed_status_thread (Thread 13466)
infrun: proceed (addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT)
infrun: step-over queue now empty
infrun: resuming [Thread 13466] for step-over
Sending packet: $m410838,22#35...Packet received: 00000000000000000000000000000000000000000000000000000000000000000000
infrun: skipping breakpoint: stepping past insn at: 0x400524
infrun: skipping breakpoint: stepping past insn at: 0x400524
Sending packet: $Z2,410838,22#80...Packet received: E01 <----- [1]
Packet Z2 (write-watchpoint) is supported
Sending packet: $Z0,7fb7fe0a8c,4#43...Packet received: OK
Warning:
Could not insert hardware watchpoint 2.
Could not insert hardware breakpoints:
You may have requested too many hardware breakpoints/watchpoints.
GDB receives E01 for Z2 packet [1] but GDBserver updates the debugging
register status,
insert_point (addr=0x00410838, len=34, type=hw-write-watchpoint):
BREAKPOINTs:
BP0: addr=0x0, ctrl=0x00000000, ref.count=0
BP1: addr=0x0, ctrl=0x00000000, ref.count=0
BP2: addr=0x0, ctrl=0x00000000, ref.count=0
BP3: addr=0x0, ctrl=0x00000000, ref.count=0
BP4: addr=0x0, ctrl=0x00000000, ref.count=0
BP5: addr=0x0, ctrl=0x00000000, ref.count=0
WATCHPOINTs:
WP0: addr=0x410850, ctrl=0x00001ff5, ref.count=1
WP1: addr=0x410848, ctrl=0x00001ff5, ref.count=1
WP2: addr=0x410840, ctrl=0x00001ff5, ref.count=1
WP3: addr=0x410838, ctrl=0x00001ff5, ref.count=1
four debugging registers can not monitor 34-byte long area, so the last
iteration of updating debugging register state fails but previous
iterations succeed. This makes GDB think no HW watchpoint is inserted
but some debugging registers are used.
This problem was exposed by "watch buf" gdb.base/watchpoint.exp with
aarch64 GDBserver debugging arm 32-bit program. The buf is 30-byte long
but 4-byte aligned, and four debugging registers can't cover 34-byte
(extend 4 bytes to be 8-byte aligned) area. However, this problem
does exist on non-multi-arch debugging scenario as well.
This patch moves code in aarch64_linux_region_ok_for_hw_watchpoint to
aarch64_linux_region_ok_for_watchpoint in nat/aarch64-linux-hw-point.c.
Then, checks with aarch64_linux_region_ok_for_watchpoint, like what we
are doing in GDB. If the region is OK, call aarch64_handle_watchpoint.
Regression tested on aarch64 with both 64-bit program and 32-bit
program. Some fails in gdb.base/watchpoint.exp are fixed.
gdb:
2015-09-03 Yao Qi <yao.qi@linaro.org>
* aarch64-linux-nat.c (aarch64_linux_region_ok_for_hw_watchpoint):
Move code to aarch64_linux_region_ok_for_watchpoint. Call
aarch64_linux_region_ok_for_watchpoint.
* nat/aarch64-linux-hw-point.c (aarch64_linux_region_ok_for_watchpoint):
New function.
* nat/aarch64-linux-hw-point.h (aarch64_linux_region_ok_for_watchpoint):
Declare it.
gdb/gdbserver:
2015-09-03 Yao Qi <yao.qi@linaro.org>
* linux-aarch64-low.c (aarch64_insert_point): Call
aarch64_handle_watchpoint if aarch64_linux_region_ok_for_watchpoint
returns true.
Since the type whose name is being set is now being allocated on the
gdbarch obstack, we should allocate its TYPE_NAME on the obstack too.
This reduces the number of individual valgrind warnings for the command
"gdb gdb" from ~300 to ~150.
Tested on x86_64-unknown-linux-gnu.
gdb/ChangeLog:
* gdb_obstack.h (obstack_strdup): Declare.
* gdb_obstack.c (obstack_strdup): Define.
* gdbarch.sh (gdbarch_obstack_strdup): Declare and define.
* gdbarch.c: Regenerate.
* gdbarch.h: Regenerate.
* gdbtypes.c (arch_type): Use gdbarch_obstack_strdup.
Following commit 8f57eec2fb ("Use gdbarch obstack to allocate types in
alloc_type_arch") it is no longer the case that the type returned by
copy_type_recursive is allocated using malloc. Because the function
uses alloc_type_arch internally, the new type is now allocated on the
gdbarch associated with the type, and is thus owned by that gdbarch.
gdb/ChangeLog:
* gdbtypes.c (copy_type_recursive): Update documentation.
Yet another BuildBot e-mail, yet another breakage on RHEL-7.1 s390x
(which uses an older GCC). This time,
solib-svr4.c:solib_event_probe_action has the probe_argc variable,
which is now inside a TRY..CATCH and therefore needs to be
initialized. Pushed as obvious.
gdb/ChangeLog:
2015-09-01 Sergio Durigan Junior <sergiodj@redhat.com>
* solib-svr4.c (solib_event_probe_action): Initialize 'probe_argc'
as zero.
BuildBot e-mailed me to let me know that my last commit broke GDB on
RHEL-7.1 s390x. On solib-svr4.c:svr4_handle_solib_event, 'val' now
needs to be initialized as NULL because it is inside a TRY..CATCH
block. This patch does that. Pushed as obvious.
gdb/ChangeLog:
2015-09-01 Sergio Durigan Junior <sergiodj@redhat.com>
* solib-svr4.c (svr4_handle_solib_event): Initialize 'val' as NULL
This patch is intended to make the interaction between the
probes-based dynamic linker interface and the SystemTap SDT probe code
on GDB more robust. It does that by wrapping the calls to the probe
API with TRY...CATCH'es, so that any exception thrown will be caught
and handled properly.
The idea for this patch came from
<https://bugzilla.redhat.com/show_bug.cgi?id=1196181>, which is a bug
initially filed against Fedora GDB (but now under Fedora GLIBC). This
bug happens on armhfp (although it could happen on other targets as
well), and is triggered because GCC generates a strange argument for
one of the probes used by GDB in the dynamic linker interface. As can
be seen in the bug, this argument is "-4@.L1052".
I don't want to discuss the reasons for this argument to be there
(this discussion belongs to the bug, or to another thread), but GDB
could definitely do a better error handling here. Currently, one sees
the following message when there is an error in the probes-based
dynamic linker interface:
(gdb) run
Starting program: /bin/inferior
warning: Probes-based dynamic linker interface failed.
Reverting to original interface.
Cannot parse expression `.L976 4@r4'.
(gdb)
Which means that one needs to explicitly issue a "continue" command to
make GDB continue running the inferior, even though this error is not
fatal and GDB will fallback to the old interface automatically.
This is where this patch helps: it makes GDB still print the necessary
warnings or error messages, but it *also* does not stop the inferior
unnecessarily.
I have tested this patch on the systems where this error happens, but
I could not come up with a way to create a testcase for it.
Nevertheless, it should be straightforward to see that this patch does
improve the current situation.
gdb/ChangeLog:
2015-09-01 Sergio Durigan Junior <sergiodj@redhat.com>
* solib-svr4.c (solib_event_probe_action): Call
get_probe_argument_count using TRY...CATCH.
(svr4_handle_solib_event): Likewise, for evaluate_probe_argument.
This patch improves the error reporting when handling SystemTap SDT
probes. "Handling", in this case, mostly means "parsing".
On gdb/probe.h, only trivial changes on functions' comments in order
to explicitly mention that some of them can throw exceptions. This is
just to make the API a bit more clear.
On gdb/stap-probe.c, I have s/internal_error/error/ on two functions
that are responsible for parsing specific bits of the probes'
arguments: stap_get_opcode and stap_get_expected_argument_type. It is
not correct to call internal_error on such situations because it is
not really GDB's fault if the probes have malformed arguments. I also
improved the error reported on stap_get_expected_argument_type by also
including the probe name on it.
Aside from that, and perhaps most importantly, I added a check on
stap_get_arg to make sure that we don't try to extract an argument
from a probe that has no arguments. This check issues an
internal_error, because it really means that GDB is doing something it
shouldn't.
Although it can be considered almost trivial, and despite the fact
that I am the maintainer for this part of the code, I am posting this
patch for review. I will wait a few days, and if nobody has anything
to say, I will go ahead and push it.
gdb/ChangeLog:
2015-09-01 Sergio Durigan Junior <sergiodj@redhat.com>
* probe.h (struct probe_ops) <get_probe_argument_count,
evaluate_probe_argument, enable_probe, disable_probe>: Mention in
the comment that the function can throw an exception.
(get_probe_argument_count): Likewise.
(evaluate_probe_argument): Likewise.
* stap-probe.c (stap_get_opcode): Call error instead of
internal_error.
(stap_get_expected_argument_type): Likewise. Add argument
'probe'. Improve error message by mentioning the probe's name.
(stap_parse_probe_arguments): Adjust call to
stap_get_expected_argument_type.
(stap_get_arg): Add comment. Assert that 'probe->args_parsed' is
not zero. Call internal_error if GDB requests an argument but the
probe has no arguments.
Before this change, trying to complete an expression ending with an
ambiguous function name (i.e. for which there are multiple matches)
would display a menu with a prompt for the user to pick one. For
instance:
(gdb) p func<tab>Multiple matches for func
[0] cancel
[1] pack2.func at pack2.adb:5
[2] pack.func at pack.adb:5
>
This is not user friendly and actually triggered a segmentation fault
after the user did pick one. It is not clear whether the segmentation
fault needs a separate fix, but this is the only known case which
exhibits it at the moment, and this case must be fixed itself.
The problem lies in ada-lang.c (ada_resolve_function): when we got
multiple matches, we should not display the menu if we are in completion
mode. This patch adjusts the corresponding condition accordingly.
gdb/ChangeLog:
* ada-lang.c (ada_resolve_function): Do not ask the user what
match to use when in completion mode.
gdb/testsuite/ChangeLog:
* gdb.ada/complete.exp: Add "pck.ambiguous_func" to the relevant
expected outputs. Add two testcases for completing ambiguous
functions.
* gdb.ada/complete/aux_pck.adb: New file.
* gdb.ada/complete/aux_pck.ads: New file.
* gdb.ada/complete/foo.adb: Pull Aux_Pck and call the two
Ambiguous_Func functions.
* gdb.ada/complete/pck.ads: Add an Ambiguous_Func function.
* gdb.ada/complete/pck.adb: Likewise.
Tested on x86_64-linux, no regression.
Small clean up to make a local variable const and remove a cast of NULL.
gdb/ChangeLog:
* tui/tui-data.c (tui_win_name): Make local variable const, remove
cast of NULL.
Use XSHAL_ABI value provided by xtensa-config.h to correctly initialize
xtensa_tdep.call_abi
This fixes calls to functions from GDB that otherwise fail with the
following assertion in call0 configuration:
gdb/regcache.c:602: internal-error: regcache_raw_read: Assertion
`regnum >= 0 && regnum < regcache->descr->nr_raw_registers' failed.
2015-08-31 Max Filippov <jcmvbkbc@gmail.com>
gdb/
* xtensa-tdep.h (XTENSA_GDBARCH_TDEP_INSTANTIATE): Initialize
call_abi using XSHAL_ABI macro.
Since the type whose name is being set is now being allocated on the
gdbarch obstack, we should allocate its TYPE_NAME on the obstack too.
This reduces the number of individual valgrind warnings for the command
"gdb gdb" from ~300 to ~150.
Tested on x86_64-unknown-linux-gnu.
gdb/ChangeLog:
* gdbarch.h (gdbarch_obstack_strdup): Declare.
* gdbarch.c (gdbarch_obstack_strdup): Define.
* gdbtypes.c (arch_type): Use it.
For the command "gdb gdb" valgrind currently reports 100s of individual
memory leaks, 500 of which originate solely out of the function
alloc_type_arch. This function allocates a "struct type" associated
with the given gdbarch using malloc but apparently the types allocated
by this function are never freed.
This patch fixes these leaks by making the function alloc_type_arch
allocate these gdbarch-associated types on the gdbarch obstack instead
of on the general heap. Since, from what I can tell, the types
allocated by this function are all fundamental "wired-in" types, such
types would not benefit from more granular memory management anyway.
They would likely live as long as the gdbarch is alive so allocating
them on the gdbarch obstack makes sense.
With this patch, the number of individual vargrind warnings emitted for
the command "gdb gdb" drops from ~800 to ~300.
Tested on x86_64-unknown-linux-gnu.
gdb/ChangeLog:
* gdbtypes.c (alloc_type_arch): Allocate the type on the given
gdbarch obstack instead of on the heap. Update commentary
accordingly.
solib_ops are installed as a property of the inferior gdbarch,
so they need to be systematically looked up via that architecture,
not some objfile architecture.
ChangeLog:
Revert:
2014-11-06 Doug Evans <xdje42@gmail.com>
* solib.c (solib_global_lookup): Fetch arch from objfile,
not target_gdbarch.
When debugging Cell/B.E. code, the cross-architecture frame unwinding
works by accessing data structures refered to by a thread-local variable
in the inferior. While accessing this variable via minimal symbol,
code would use BMSYMBOL_VALUE_ADDRESS to determine the offset of the
variable in the thread-local storage block.
This is incorrect, since it adds any relocation offset of the shared
library defining the TLS variable. That offset would be OK when
accessing the initial copy present in the .tbss section, but it must
not be applied to the offset of the variable in the TLS block at
runtime. Depending on whether or not the libspe2.so library was
prelinked, access to the variable would fail due to the incorrectly
relocated offset.
ChangeLog:
* ppc-linux-tdep.c (ppc_linux_spe_context_lookup): Do not
attempt to relocate a TLS variable offset.
With recent changes to inferior handling, parse_spufs_run needs to be
more careful in assumptions it makes. In particular, this patch:
- Bails out early if the current inferior has not yet been registered
(e.g. during fork procession) to avoid assertion failures in register
cache code.
- Sets inferior_ptid to the current ptid while calling target_read_memory
to make sure the correct process is accessed if parse_spufs_run is
called early when inferior_ptid has not yet been switched by the caller.
ChangeLog:
* spu-multiarch.c (parse_spufs_run): Bail out if inferior is not
registered yet. Set inferior_ptid while calling target_read_memory.
The Linux target and gdbserver now check the siginfo si_code
reported on a SIGTRAP to detect whether the trap indicates
a software breakpoint was hit.
Unfortunately, on Cell/B.E., the kernel uses an si_code value
of TRAP_BRKPT when a SW breakpoint was hit in PowerPC code,
but a si_code value of SI_KERNEL when a SW breakpoint was
hit in SPU code.
This patch updates Linux target and gdbserver to accept both
si_code values to indicate SW breakpoint on PowerPC.
ChangeLog:
* nat/linux-ptrace.h (GDB_ARCH_TRAP_BRKPT): Replace by ...
(GDB_ARCH_IS_TRAP_BRKPT): ... this. Add __powerpc__ case.
* linux-nat.c (check_stopped_by_breakpoint): Use
GDB_ARCH_IS_TRAP_BRKPT instead of GDB_ARCH_TRAP_BRKPT.
gdbserver/ChangeLog:
* linux-low.c (check_stopped_by_breakpoint): Use
GDB_ARCH_IS_TRAP_BRKPT instead of GDB_ARCH_TRAP_BRKPT.
Since we are no longer using thread events by default in linux-thread-db,
the find_new_threads_once routine contains an assertion that it should
never be called on a live inferior unless using thread events:
gdb_assert (!target_has_execution || thread_db_use_events ());
However, there is a code path from thread_db_get_thread_local_address
that will in fact call find_new_threads_once in some scenarios. In
particular, this is currently always triggered when starting up any
Cell/B.E. combined exeuctable.
To fix this, this patch removes the call to thread_db_find_new_threads_1
when the current thread was not yet detected. In its place, we now just
call thread_from_lwp to detect this one thread if necessary.
ChangeLog:
* linux-thread-db.c (thread_db_get_thread_local_address): If the
thread was not yet discovered, use thread_from_lwp instead of
calling thread_db_find_new_threads_1.
These two statements were inverted by mistake in commit "Replace some
xmalloc-family functions with XNEW-family ones". It obviously doesn't
make sense to have them in this order, which is why I am pushing this as
obvious.
gdb/ChangeLog:
* m88k-tdep.c (m88k_analyze_prologue): Fix inverted allocation
statements.
I think it would be a good idea to document that gdb now has (basic)
support to read/write memory on architectures with non-8-bits memory.
Hopefully somebody will see it and say "Hey! We can now (more easily)
port GDB to our strange DSP that has 32-bits-addressable memory!" and do
it.
gdb/ChangeLog:
* NEWS: Document support for non-8-bits addressable memory.
Since we're using sighandler_t, nothing else refers to RETSIGTYPE in
gdb.
(Actually, given gdb/remote.c has been assuming signal handlers return
void for a long time, we could have gotten get rid of this even
without gnulib's sighandler_t.)
gdb/ChangeLog:
2015-08-27 Pedro Alves <palves@redhat.com>
* configure.ac: Remove AC_TYPE_SIGNAL call.
* configure, config.in: Regenerate.
