The mapping between Ada tasks, and the underlying threads is
normally maintained by the GNAT runtime under the known_tasks
array. For performance reasons, this array is just a static
array with 10_000 entries in it. However, this is not very
practical in certain environments where memory is limited.
For those environments, the runtime has been enhanced to use
an alternate scheme with a linked list.
This change enhances the Ada tasking support to recognize this
situation and use the correct way of reading the tasks info
based on the the situation.
gdb/ChangeLog (Tristan Gingold)
* ada-tasks.c (KNOWN_TASKS_LIST): New macro.
(tcb_fieldno): Add activation_link field.
(get_known_tasks_addr): Moved and rewritten.
(get_tcb_types_info): Set activation_link field.
(read_known_tasks_array): Add parameter. Rewritten.
(read_known_tasks_list): New function.
(read_known_tasks): New function.
(ada_build_task_list): Call read_known_tasks instead of
read_known_tasks_array.
* ravenscar-thread.c: Add first_task_name constant.
(has_ravenscar_runtime): Check for task list too.
Just some minor cleanup changes in preparation for an upcoming
change...
gdb/ChangeLog (Tristan Gingold)
* ada-tasks.c: Renames fieldno to actb_fieldno.
(ada_get_task_number): Indentation.
(get_tcb_types_info): Remove all parameters. Write directly
the globals.
(ptid_from_atcb_common): Adjust.
(read_atcb): Adjust.
Type symbols that are used to decode the Ada task control block may be
duplicated in any unit that uses a tasking feature; an Ada lookup of
these symbols would collect all the duplicated instances and could
provoke the load of a huge amount of debug symbols in the process.
However, when decoding the task information, we are only interested in
one instance; and we have the full name of the symbol anyway. So use
a C lookup instead of an Ada lookup.
2010-11-05 Jerome Guitton <guitton@adacore.com>
* ada-tasks.c (get_tcb_types_info): Use C lookups to get
ATCB symbols.
This new function is needed by the ravenscar-thread layer.
gdb/ChangeLog:
* ada-tasks.c (iterate_over_live_ada_tasks): New function.
* ada-lang.h (iterate_over_live_ada_tasks): Declare.
After thread support over core files was added for GNU/Linux was added,
we started noticing the following type of crash when trying to perform
task switches (this is a bit accademic, since task switching is not
supported when debugging core files - this is what our testcase was
verifying).
(please check out the comment inside ada-tasks.c:task_command for
more details on this topic)
The reason for the crash comes from the fact that the GNU/Linux thread
layer now gets pushed on the target stack, causing the associated
to_get_ada_task_ptid target method to be activated. This routine
makes the assumption that, for all threads, the private area is not
NULL. This is incorrect in the case of core files, as the core layer
creates some threads with no private data.
But, taking a step back, we don't need to try to compute the task ptid,
as we'll never be using it anyways (we only use it for task switching).
So the fix is to avoid the ptid computation altogether when debugging
a core file.
gdb/ChangeLog:
* ada-tasks.c (read_atcb): Do not compute the task ptid when
debugging a core file.
This is to prevent an internal error during an Ada task switch. A task
switch is simply a thread switch under the hood. What we do is collect
the info from the Ada Task Control Block, deduce the associated thread
ptid, and then switch to that thread. If the thread ptid computation
routine has not been implemented for the target, of if there is a bug,
then we end up computing a bogus ptid which GDB does not know about,
which eventually leads to an assertion failure:
(gdb) task 1
[New Thread 5715]
/[...]/gdb/thread.c:595: internal-error: is_thread_state:
Assertion `tp' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)
When this happens, it's just nicer for the user to print an error
message, and cancel the task switch. After this patch is applied,
this is what we get:
(gdb) task 1
[New Thread 10250]
Unable to compute thread ID for task 1.
Cannot switch to this task.
gdb/ChangeLog:
* ada-tasks.c (task_command_1): Check that the task ptid is valid
before doing the associated thread switch.
value_bitstring_subscript, value_ptradd): Use LONGEST instead
of value as type of the index argument.
(value_ptrsub): Remove.
* valarith.c (value_subscript, value_subscripted_rvalue,
value_bitstring_subscript, value_ptradd): Use LONGEST instead
of value as type of the index argument.
(value_ptrsub): Remove.
* wrapper.h (gdb_value_subscript): Use LONGEST instead of
value as type of the index argument.
* wrapper.c (gdb_value_subscript): Likewise.
Update calls to gdb_value_subscript, value_subscript,
value_subscripted_rvalue, value_bitstring_subscript and
value_ptradd to use LONGEST instead of value as index
argument type. Use value_ptradd instead of value_ptrsub.
* ada-lang.c (ada_value_subscript, ada_value_ptr_subscript,
ada_tag_name_2): Update.
* ada-tasks.c (read_atcb): Update.
* eval.c (evaluate_subexp_standard): Update.
* valarith.c (value_subscript): Update.
* gnu-v2-abi.c (gnuv2_virtual_fn_field): Update.
* gnu-v3-abi.c (gnuv3_get_virtual_fn, gnuv3_baseclass_offset,
gnuv3_method_ptr_to_value): Update.
* jv-lang.c (evaluate_subexp_java): Update.
* m2-lang.c (evaluate_subexp_modula2): Update.
* python/python-value.c (valpy_getitem, valpy_binop): Update.
* wrapper.c (gdb_value_subscript): Update.
* varobj.c (c_describe_child): Update.
Silence a few -Wmissing-prototypes warnings.
PR build/9877:
* amd64-nat.c: Include "amd64-nat.h".
* fork-child.c (_initialize_fork_child): Ditto.
* gcore.c (_initialize_gcore): Ditto.
* inf-ptrace.c: Include "inf-ptrace.h".
(inf_ptrace_store_registers): Make it static.
* linux-nat.c (linux_nat_terminal_ours): Make it static.
(_initialize_linux_nat): Declare before definition.
* linux-tdep.c: Include "linux-tdep.h".
* linux-thread-db.c (_initialize_thread_db): Declare before
definition.
* proc-service.c (_initialize_proc_service): Ditto.
* remote.c (remote_send_printf): Make it static.
* solib.c: Include "solib.h".
* symfile-mem.c (_initialize_symfile_mem): Declare before
definition.
* ada-lang.c (ada_la_decode, ada_match_name)
(ada_suppress_symbol_printing, ada_is_array_type)
(ada_value_ptr_subscript, ada_array_length)
(ada_to_static_fixed_value): Make them static.
(_initialize_ada_language): Declare before definition.
* ada-tasks.c (ada_get_task_number, ada_get_environment_task)
(ada_task_list_changed, ada_new_objfile_observer): Make them
static.
(_initialize_tasks): Declare before definition.
* addrmap.c (_initialize_addrmap): Declare before definition.
* auxv.c (default_auxv_parse): Make it static.
* bfd-target.c (target_bfd_xfer_partial, target_bfd_xclose): Make
them static.
* breakpoint.c (remove_sal): Add line break.
(expand_line_sal_maybe): Make it static.
* cp-name-parser.y: Include "cp-support.h".
* cp-valprint.c (cp_find_class_member): Make it static.
* eval.c (value_f90_subarray): Ditto.
* exceptions.c (print_any_exception): Ditto.
* findcmd.c (_initialize_mem_search): Declare before definition.
* frame.c (frame_observer_target_changed): Make it static.
* gnu-v3-abi.c (gnuv3_find_method_in): Make it static.
* inf-child.c: Include "inf-child.h".
* inferior.h (valid_inferior_id): Rename to ...
(valid_gdb_inferior_id): ... this.
* infrun.c (infrun_thread_stop_requested, siginfo_make_value):
Make them static.
* jv-lang.c (java_language_arch_info): Make it static.
* m2-typeprint.c (m2_get_discrete_bounds): Ditto.
* osdata.c (info_osdata_command): Make it static.
* regcache.c (regcache_observer_target_changed): Make it static.
* reverse.c (_initialize_reverse): Declare before definition.
* stabsread.c (cleanup_undefined_types_noname)
(cleanup_undefined_types_1): Make them static.
* symfile.c (place_section): Make it static.
* symtab.c (find_pc_sect_psymtab_closer): Make it static.
* target-descriptions.c (_initialize_target_descriptions): Declare
before definition.
* target.c (default_get_ada_task_ptid, find_default_can_async_p)
(find_default_is_async_p, find_default_supports_non_stop): Make
them static.
(target_supports_non_stop): Add prototype.
(dummy_pid_to_str): Make it static.
* utils.c (_initialize_utils): Declare before definition.
* ada-exp.y (_initialize_ada_exp): Declare before definition.
* solib-svr4.c (HAS_LM_DYNAMIC_FROM_LINK_MAP): Add a prototype.
* target.h (struct target_ops): Add a prototype to the
to_can_execute_reverse callback.
* macroscope.c (_initialize_macroscope): Declare before definition.
* cp-namespace.c (_initialize_cp_namespace): Declare before definition.
* python/python.c (_initialize_python): Declare before definition.
* tui/tui-command.c: Include "tui/tui-command.h".
* tui/tui-data.c (init_content_element, init_win_info): Make them
static.
* tui/tui-disasm.c: Include "tui/tui-disasm.h".
* tui/tui-interp.c (_initialize_tui_interp): Declare before
definition.
* tui/tui-layout.c: Include "tui/tui-layout.h".
(_initialize_tui_layout): Declare before definition.
* tui/tui-regs.c: Include "tui/tui-regs.h".
(tui_display_reg_element_at_line): Make it static.
(_initialize_tui_regs): Declare before definition.
* tui/tui-stack.c (_initialize_tui_stack): Declare before
definition.
* tui/tui-win.c: Include "tui/tui-win.h".
(_initialize_tui_win): Declare before definition.
(tui_sigwinch_handler): Make it static. Wrap in ifdef SIGWINCH.
* tui/tui-win.h (tui_sigwinch_handler): Delete declaration.
(tui_get_cmd_list): Add a prototype.
* tui/tui-windata.c: Include tui-windata.h.
* tui/tui-wingeneral.c (box_win): Make it static.
* cli/cli-logging.c (show_logging_command): Make it static.
(_initialize_cli_logging): Declare before definition.
* mi/mi-common.c (_initialize_gdb_mi_common): Declare before
definition.
* ada-tasks.c (ada_normal_stop_observer): Adjust prototype.
* infcmd.c (finish_command_continuation): Pass '1' for
'print_frame' parameter to the observer.
* infrun.c (normal_stop): Don't print mi-specific information
here. Pass 'stop_print_frame' to the 'print_frame' parameter
of the observer.
* mi/mi-interp.c (mi_on_normal_stop): Adjust prototype.
If we need to print frame, and current uiout is not the MI one,
print frame again.
make it non-static.
* ada-lang.h (task_control_block): declaration moved from ada-task.c
to ada-lang.h; this is needed to be able to implement the kill command
in multi-task mode.
(task_ptid): Ditto.
(task_entry): Ditto.
(task_list): Ditto.
(ada_build_task_list): Ditto.
* ada-lang.c: Conditionalize routines and data structures related
to breakpoints, exceptions, completion, and symbol caching on
GNAT_GDB, since these are not yet used in the submitted public sources.
(ada_main_name): Editorial: Move definition out of exception-related
code.
* ada-lang.h: run through gdb_indent.sh
* ada-tasks.c: run through gdb_indent.sh
* ada-typeprint.c: run through gdb_indent.sh
* ada-valprint.c: run through gdb_indent.sh
malloc() with xmalloc
* ada-tasks.c (init_task_list): replace calls to free with xfree()
* ada-lang.c (replace_operator_with_call, fill_in_ada_prototype,
ada_finish_decode_line_1, all_sals_for_line
ada_breakpoint_rewrite): replace calls to free() with xfree()
