binutils-gdb/gdb/ChangeLog
Joel Brobecker 2eab46b176 GDB crash re-running program on Windows (native)
Running any program twice on Windows current results in GDB crashing:

    $ gdb -q any_program
    (gdb) run
    $ gdb dummy -batch -ex run -ex run
    [New Thread 684960.0xe5878]
    [New Thread 684960.0xd75ac]
    [New Thread 684960.0xddac8]
    [New Thread 684960.0xc1f50]
    [Thread 684960.0xd75ac exited with code 0]
    [Thread 684960.0xddac8 exited with code 0]
    [Thread 684960.0xc1f50 exited with code 0]
    [Inferior 1 (process 684960) exited normally]
    (gdb) run
    Segmentation fault

The crash happens while processing the CREATE_PROCESS_DEBUG_EVENT
for  the second run; in particular, we have in get_windows_debug_event:

    | case CREATE_PROCESS_DEBUG_EVENT:
    |   [...]
    |   if (main_thread_id)
    |     windows_delete_thread (ptid_t (current_event.dwProcessId, 0,
    |                                    main_thread_id),
    |                            0);

The problem is that main_thread_id is the TID of the main thread from
the *previous* inferior, and this code is trying to delete that
thread. The problem is that it is constructing a PTID by pairing
the TID of the previous inferior with the PID of the new inferior.
As a result, when we dig inside windows_delete_thread to see
how it would handle that, we see...

    | delete_thread (find_thread_ptid (ptid));

Since the PTID is bogus, we end up calling delete_thread with
a NULL thread_info. It used to be harmless, turning the delete_thread
into a nop, but the following change...

    | commit 0803633106
    | Date:   Thu Nov 22 16:09:14 2018 +0000
    | Subject: Per-inferior thread list, thread ranges/iterators, down with ALL_THREADS, etc.

... changed delete_thread to get the list of threads from
the inferior, which itself is now accessed via the given
thread_info. This is the corresponding diff that shows the change:

    | -  for (tp = thread_list; tp; tpprev = tp, tp = tp->next)
    | +  for (tp = thr->inf->thread_list; tp; tpprev = tp, tp = tp->next)

As a result of this, passing a NULL thread_info is no longer
an option!

Stepping back a bit, the reason behind deleting the thread late
could be found in a patch from Dec 2003, which laconically explains:

    | commit 87a45c9606
    | Date:   Fri Dec 26 00:39:04 2003 +0000
    |
    | * win32-nat.c (get_child_debug_event): Keep main thread id around
    | even after thread exits since Windows insists on continuing to
    | report events against it.

A look at the gdb-patches archives did not provide any additional
clues (https://www.sourceware.org/ml/gdb-patches/2003-12/msg00478.html).
It is not clear whether this is still needed or not. This patch
assumes that whatever isue there was, the versions of Windows
we currently support no longer have it.

With that in mind, this commit fixes the issue by deleting the thread
when the inferior sends the exit-process event as opposed to deleting it
later, while starting a new inferior.

This also restores the printing of the thread-exit notification for
the main thread, which was missing before. Looking at the transcript
of the example shown above, we can see 4 thread creation notifications,
and only 3 notifications for thread exits. Now creation and exit
notifications are balanced.

In the handling of EXIT_THREAD_DEBUG_EVENT, the main_thread_id
check is removed because deemed unnecessary: The main thread was
introduced by a CREATE_PROCESS_DEBUG_EVENT, and thus the kernel
is expected to report its death via EXIT_PROCESS_DEBUG_EVENT.

And finally, because the behavior of delete_thread did change
(albeit when getting a value we probably never expected to receive),
this patch also adds a gdb_assert. The purpose is to provide some
immediate information in case there are other callers that mistakenly
call delete_thread with a NULL thread info. This can be useful
information when direct debugging of GDB isn't an option.

gdb/ChangeLog:

	* thread.c (delete_thread_1): Add gdb_assert that THR is not
	NULL. Initialize tpprev to NULL instead of assigning it
	to NULL on the next statement.
	* windows-nat.c (windows_delete_thread): Remove check for
	main_thread_id before printing thread exit notifications.
	(get_windows_debug_event) <EXIT_THREAD_DEBUG_EVENT>:
	Remove thread ID check against main_thread_id.
	<CREATE_PROCESS_DEBUG_EVENT>: Remove call to
	windows_delete_thread.
	<EXIT_PROCESS_DEBUG_EVENT>: Add call to windows_delete_thread.
2019-01-05 11:55:08 +04:00

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2019-01-05 Joel Brobecker <brobecker@adacore.com>
* thread.c (delete_thread_1): Add gdb_assert that THR is not
NULL. Initialize tpprev to NULL instead of assigning it
to NULL on the next statement.
* windows-nat.c (windows_delete_thread): Remove check for
main_thread_id before printing thread exit notifications.
(get_windows_debug_event) <EXIT_THREAD_DEBUG_EVENT>:
Remove thread ID check against main_thread_id.
<CREATE_PROCESS_DEBUG_EVENT>: Remove call to
windows_delete_thread.
<EXIT_PROCESS_DEBUG_EVENT>: Add call to windows_delete_thread.
2019-01-04 Tom Tromey <tom@tromey.com>
* compile/compile.c (_initialize_compile): Use upper case for
metasyntactic variables.
* symmisc.c (_initialize_symmisc): Use upper case for
metasyntactic variables.
* psymtab.c (_initialize_psymtab): Use upper case for
metasyntactic variables.
* demangle.c (demangle_command): Use upper case for metasyntactic
variables.
(_initialize_demangler): Likewise.
* ax-gdb.c (_initialize_ax_gdb): Use upper case for metasyntactic
variables.
2019-01-03 Tom Tromey <tom@tromey.com>
* tui/tui-source.c (tui_set_source_content): Use xstrdup.
2019-01-03 Tom Tromey <tom@tromey.com>
* python/py-symtab.c (salpy_str): Update.
(struct salpy_sal_object) <symtab>: Now a PyObject.
(salpy_dealloc): Update.
(del_objfile_sal): Use gdbpy_ref.
2019-01-03 Tom Tromey <tom@tromey.com>
* python/py-type.c (convert_field): Use new_reference. Return
gdbpy_ref.
(make_fielditem): Return gdbpy_ref.
(typy_fields): Update.
(typy_getitem): Update.
(field_name): Return gdbpy_ref. Use new_reference.
(typy_iterator_iternext): Update.
2019-01-03 Tom Tromey <tom@tromey.com>
* python/py-record.c (gdbpy_stop_recording): Use Py_RETURN_NONE.
2019-01-03 Tom Tromey <tom@tromey.com>
* python/py-value.c (valpy_dealloc): Use Py_XDECREF.
* python/py-type.c (typy_fields_items): Use gdbpy_ref.
* python/py-progspace.c (pspy_set_printers): Use gdbpy_ref.
(pspy_set_frame_filters, pspy_set_frame_unwinders)
(pspy_set_type_printers): Likewise.
* python/py-function.c (fnpy_init): Use gdbpy_ref.
* python/py-cmd.c (cmdpy_init): Use gdbpy_ref.
* python/py-objfile.c (objfpy_set_printers): Use gdbpy_ref.
(objfpy_set_frame_filters, objfpy_set_frame_unwinders)
(objfpy_set_type_printers): Likewise.
2019-01-03 Tom Tromey <tom@tromey.com>
* python/python.c (gdbpy_enter, ~gdbpy_enter): Update.
(gdbpy_print_stack): Use gdbpy_err_fetch.
* python/python-internal.h (class gdbpy_err_fetch): New class.
(class gdbpy_enter) <m_error_type, m_error_value,
m_error_traceback>: Remove.
<m_error>: New member.
(gdbpy_exception_to_string): Don't declare.
* python/py-varobj.c (py_varobj_iter_next): Use gdbpy_err_fetch.
* python/py-value.c (convert_value_from_python): Use
gdbpy_err_fetch.
* python/py-utils.c (gdbpy_err_fetch::to_string): Rename from
gdbpy_exception_to_string.
(gdbpy_handle_exception): Use gdbpy_err_fetch.
* python/py-prettyprint.c (print_stack_unless_memory_error): Use
gdbpy_err_fetch.
2019-01-03 Andrew Burgess <andrew.burgess@embecosm.com>
* linux-nat.c (delete_lwp_cleanup): Delete.
(struct lwp_deleter): New struct.
(lwp_info_up): New typedef.
(linux_nat_target::follow_fork): Delete cleanup, and make use of
lwp_info_up.
2019-01-03 Andrew Burgess <andrew.burgess@embecosm.com>
* linux-fork.c (class scoped_switch_fork_info): New class.
(inferior_call_waitpid): Update to use scoped_switch_fork_info.
2019-01-03 Andrew Burgess <andrew.burgess@embecosm.com>
* valops.c (find_overload_match): Remove use of null_cleanup, and
calls to do_cleanups.
2019-01-03 Andrew Burgess <andrew.burgess@embecosm.com>
* compile/compile-cplus-types.c
(compile_cplus_instance::decl_name): Handle changes to
cp_func_name.
* cp-support.c (cp_func_name): Update header comment, update
return type.
* cp-support.h (cp_func_name): Update return type in declaration.
* valops.c (find_overload_match): Move temp_func local to top
level of function and change its type. Use temp_func to hold and
delete temporary string obtained from cp_func_name.
2019-01-03 Andrew Burgess <andrew.burgess@embecosm.com>
* remote.c (remote_target::remote_check_symbols): Convert `msg` to
gdb::char_vector, remove cleanup, and update uses of `msg`.
2019-01-03 Jim Wilson <jimw@sifive.com>
* riscv-tdep.c (riscv_freg_feature): Drop s0 name from f8.
2019-01-02 Tom Tromey <tom@tromey.com>
* xml-tdesc.c (xml_cache): Hold a target_desc_up.
(tdesc_parse_xml): Remove cleanups.
* target-descriptions.h (make_cleanup_free_target_description):
Don't declare.
(target_desc_deleter): New struct.
(target_desc_up): New typedef.
* target-descriptions.c (target_desc_deleter::operator()): Rename
from free_target_description.
(make_cleanup_free_target_description): Remove.
2019-01-02 Tom Tromey <tom@tromey.com>
* linespec.c (struct linespec_parser): Rename from ls_parser. Add
constructor, destructor.
(linespec_parser): Remove typedef.
(~linespec_parser): Rename from linespec_parser_delete.
(linespec_lex_to_end, linespec_complete_label)
(linespec_complete): Update.
(decode_line_full): Remove cleanups.
(decode_line_1): Update.
2019-01-02 Tom Tromey <tom@tromey.com>
* python/python-internal.h (inferior_to_inferior_object): Change
return type.
* python/py-exitedevent.c (create_exited_event_object): Update.
* python/py-inferior.c (inferior_to_inferior_object): Return
gdbpy_ref.
(python_new_inferior, python_inferior_deleted)
(thread_to_thread_object, delete_thread_object)
(build_inferior_list, gdbpy_selected_inferior): Update.
* python/py-infthread.c (create_thread_object): Update. Also fail
if inferior_to_inferior_object fails.
2019-01-02 Simon Marchi <simon.marchi@ericsson.com>
* inferior.h (class inferior) <displaced_step_state>: New field.
* infrun.h (struct displaced_step_state): Move here from
infrun.c. Initialize fields, add constructor.
<inf>: Remove field.
<reset>: New method.
* infrun.c (struct displaced_step_inferior_state): Move to
infrun.h.
(displaced_step_inferior_states): Remove.
(get_displaced_stepping_state): Adust.
(displaced_step_in_progress_any_inferior): Adjust.
(displaced_step_in_progress_thread): Adjust.
(displaced_step_in_progress): Adjust.
(add_displaced_stepping_state): Remove.
(get_displaced_step_closure_by_addr): Adjust.
(remove_displaced_stepping_state): Remove.
(infrun_inferior_exit): Call displaced_step_state.reset.
(use_displaced_stepping): Don't check for NULL.
(displaced_step_prepare_throw): Call
get_displaced_stepping_state.
(displaced_step_fixup): Don't check for NULL.
(prepare_for_detach): Don't check for NULL.
2019-01-02 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* infcall.c (call_function_by_hand_dummy): cleanup/destroy sm
in case of call that did not complete.
2019-01-02 Andrey Utkin <autkin@undo.io>
* symfile.c (find_separate_debug_file): Fix search of debug files for
remote debuggee.
2019-01-02 Tom Tromey <tom@tromey.com>
* python/py-inferior.c (gdbpy_initialize_inferior): Fix
indentation.
* python/py-frame.c (frapy_older): Remove cast.
(frapy_newer): Likewise.
* python/py-breakpoint.c (local_setattro): Remove cast.
* python/py-arch.c (archpy_name): Remove local variable.
* python/py-type.c (gdbpy_lookup_type): Remove cast.
2019-01-02 Joel Brobecker <brobecker@adacore.com>
* unittests/basic_string_view/element_access/char/empty.cc:
Fix year range in copyright header.
2019-01-01 Andrew Burgess <andrew.burgess@embecosm.com>
* arch/riscv.h (struct riscv_gdbarch_features) <hw_float_abi>:
Delete.
<operator==>: Update with for removed field.
<hash>: Likewise.
* riscv-tdep.h (struct gdbarch_tdep) <features>: Renamed to...
<isa_features>: ...this.
<abi_features>: New field.
(riscv_isa_flen): Update comment.
(riscv_abi_xlen): New declaration.
(riscv_abi_flen): New declaration.
* riscv-tdep.c (riscv_isa_xlen): Update to get answer from
isa_features.
(riscv_abi_xlen): New function.
(riscv_isa_flen): Update to get answer from isa_features.
(riscv_abi_flen): New function.
(riscv_has_fp_abi): Update to get answer from abi_features.
(riscv_call_info::riscv_call_info): Use abi xlen and flen, not isa
xlen and flen.
(riscv_call_info) <xlen, flen>: Update comment.
(riscv_call_arg_struct): Remove invalid assertions
(riscv_features_from_gdbarch_info): Update now hw_float_abi field
is removed.
(riscv_gdbarch_init): Gather isa features and abi features
separately, ensure both match on the gdbarch when reusing an old
gdbarch. Relax an error check to allow 32-bit abi float to run on
a target with 64-bit float hardware.
2019-01-01 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* source.c (search_command_helper): Stop reverse search
when line 1 has been searched.
2019-01-01 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* record-full.c (record_full_base_target::close): Rewrite
record_full_core_buf_list free logic.
2019-01-01 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* break-catch-syscall.c (print_one_catch_syscall): xfree
the last text.
2019-01-01 Joel Brobecker <brobecker@adacore.com>
* top.c (print_gdb_version): Update Copyright year in version
message.
2019-01-01 Joel Brobecker <brobecker@adacore.com>
Update copyright year range in all GDB files.
2019-01-01 Joel Brobecker <brobecker@adacore.com>
* config/djgpp/fnchange.lst: Add entry for gdb/ChangeLog-2018.
For older changes see ChangeLog-2018.
Local Variables:
mode: change-log
left-margin: 8
fill-column: 74
version-control: never
coding: utf-8
End: