Commit Graph

109222 Commits

Author SHA1 Message Date
Pedro Alves
8a841a3579 Re-add zombie leader on exit, gdbserver/linux
Same as the previous patch, but for GDBserver.

In summary, the current zombie leader detection code in linux-low.cc
has a race -- if a multi-threaded inferior exits just before
check_zombie_leaders finds that the leader is now zombie via checking
/proc/PID/status, check_zombie_leaders deletes the leader, assuming we
won't get an event for that exit (which we won't in some scenarios,
but not in this one), which is a false-positive scenario, where the
whole process is simply exiting.  Later when we see the last LWP in
our list exit, we report that LWP's exit status as exit code, even
though for the (real) parent process, the exit code that counts is the
child's leader thread's exit code.

Like for GDB, the solution here is to:

   - only report whole-process exit events for the leader.
   - re-add the leader back to the LWP list when we finally see it
     exit.

Change-Id: Id2d7bbb51a415534e1294fff1d555b7ecaa87f1d
2022-03-10 11:35:54 +00:00
Pedro Alves
6cf20c46e3 Re-add zombie leader on exit, gdb/linux
The current zombie leader detection code in linux-nat.c has a race --
if a multi-threaded inferior exits just before check_zombie_leaders
finds that the leader is now zombie via checking /proc/PID/status,
check_zombie_leaders deletes the leader, assuming we won't get an
event for that exit (which we won't in some scenarios, but not in this
one).  That might seem mostly harmless, but it has some downsides:

 - later when we continue pulling events out of the kernel, we will
   collect the exit event of the non-leader threads, and once we see
   the last lwp in our list exit, we return _that_ lwp's exit code as
   whole-process exit code to infrun, instead of the leader's exit
   code.

 - this can cause a hang in stop_all_threads in infrun.c.  Say there
   are 2 threads in the process.  stop_all_threads stops each of those
   threads, and then waits for two stop or exit events, one for each
   thread.  If the whole process exits, and check_zombie_leaders hits
   the false-positive case, linux-nat.c will only return one event to
   GDB (the whole-process exit returned when we see the last thread,
   the non-leader thread, exit), making stop_all_threads hang forever
   waiting for a second event that will never come.

However, in this false-positive scenario, where the whole process is
exiting, as opposed to just the leader (with pthread_exit(), for
example), we _will_ get an exit event shortly for the leader, after we
collect the exit event of all the other non-leader threads.  Or put
another way, we _always_ get an event for the leader after we see it
become zombie.

I tried a number of approaches to fix this:

#1 - My first thought to address the race was to make GDB always
report the whole-process exit status for the leader thread, not for
whatever is the last lwp in the list.  We _always_ get a final exit
(or exec) event for the leader, and when the race triggers, we're not
collecting it.

#2 - My second thought was to try to plug the race in the first place.

I thought of making GDB call waitpid/WNOHANG for all non-leader
threads immediately when the zombie leader is detected, assuming there
would be an exit event pending for each of them waiting to be
collected.  Turns out that that doesn't work -- you can see the leader
become zombie _before_ the kernel kills all other threads.  Waitpid in
that small time window returns 0, indicating no-event.  Thankfully we
hit that race window all the time, which avoided trading one race for
another.  Looking at the non-leader thread's status in /proc doesn't
help either, the threads are still in running state for a bit, for the
same reason.

#3 - My next attempt, which seemed promising, was to synchronously
stop and wait for the stop for each of the non-leader threads.  For
the scenario in question, this will collect all the exit statuses of
the non-leader threads.  Then, if we are left with only the zombie
leader in the lwp list, it means we either have a normal while-process
exit or an exec, in which case we should not delete the leader.  If
_only_ the leader exited, like in gdb.threads/leader-exit.exp, then
after pausing threads, we will still have at least one live non-leader
thread in the list, and so we delete the leader lwp.  I got this
working and polished, and it was only after staring at the kernel code
to convince myself that this would really work (and it would, for the
scenario I considered), that I realized I had failed to account for
one scenario -- if any non-leader thread is _already_ stopped when
some thread triggers a group exit, like e.g., if you have some threads
stopped and then resume just one thread with scheduler-locking or
non-stop, and that thread exits the process.  I also played with
PTRACE_EVENT_EXIT, see if it would help in any way to plug the race,
and I couldn't find a way that it would result in any practical
difference compared to looking at /proc/PID/status, with respect to
having a race.

So I concluded that there's no way to plug the race, we just have to
deal with it.  Which means, going back to approach #1.  That is the
approach taken by this patch.

Change-Id: I6309fd4727da8c67951f9cea557724b77e8ee979
2022-03-10 11:35:54 +00:00
Pedro Alves
aa40a989ef gdbserver: Reindent check_zombie_leaders
This fixes the indentation of
linux_process_target::check_zombie_leaders, which will help with
keeping its comments in sync with the gdb/linux-nat.c counterpart.

Change-Id: I37332343bd80423d934249e3de2d04feefad1891
2022-03-10 11:35:53 +00:00
Pedro Alves
5406bc3f1b gdbserver: Reorganize linux_process_target::filter_event
Reorganize linux-low.cc:linux_process_target::filter_event such that
all the handling for events for LWPs not in the LWP list is together.
This helps make a following patch clearer.  The comments and debug
messages have also been tweaked to have them synchronized with the GDB
counterpart.

Change-Id: If9019635f63a846607cfda44b454b4254a404019
2022-03-10 11:35:53 +00:00
Pedro Alves
1abeb1e90d gdb: Reorganize linux_nat_filter_event
Reorganize linux-nat.c:linux_nat_filter_event such that all the
handling for events for LWPs not in the LWP list is together.  This
helps make a following patch clearer.  The comments and debug messages
have also been tweaked - the end goal is to have them synchronized
with the gdbserver counterpart.

Change-Id: I8586d8dcd76d8bd3795145e3056fc660e3b2cd22
2022-03-10 11:35:53 +00:00
Pedro Alves
b7b1008c0b Fix gdb.threads/current-lwp-dead.exp race
If we make GDB report the process EXIT event for the leader thread, as
will be done in a latter patch of this series, then
gdb.threads/current-lwp-dead.exp starts failing:

 (gdb) break fn_return
 Breakpoint 2 at 0x5555555551b5: file /home/pedro/rocm/gdb/build/gdb/testsuite/../../../src/gdb/testsuite/gdb.threads/current-lwp-dead.c, line 45.
 (gdb) continue
 Continuing.
 [New LWP 2138466]
 [Inferior 1 (process 2138459) exited normally]
 (gdb) FAIL: gdb.threads/current-lwp-dead.exp: continue to breakpoint: fn_return (the program exited)

The inferior exit reported is actually correct.  The main thread has
indeed exited, and that's the thread that has the right exit code to
report to the user, as that's the exit code that is reported to the
program's parent.  In this case, GDB managed to collect the exit code
for the leader thread before reaping the other thread, because in
reality, the testcase isn't creating standard threads, it is using raw
clone, and the new clones are put in their own thread group.

Fix it by making the main "thread" not exit until the scenario we're
exercising plays out.  Also, run the program to completion for
completeness.

The original program really wanted the leader thread to exit before
the fn_return function was reached -- it was important that the
current thread as pointed by inferior_ptid was gone when infrun got
the breakpoint event.  I've tweaked the testcase to ensure that that
condition is still held, though it is no longer the main thread that
exits.  This required a bit of synchronization between the threads,
which required using CLONE_VM unconditionally.  The #ifdef guards were
added as a fix for
https://sourceware.org/bugzilla/show_bug.cgi?id=11214, though I don't
think they were necessary because the program is not using TLS.  If it
turns out they were necessary, we can link the testcase with "-z now"
instead, which was mentioned as an alternative workaround in that
Bugzilla.

Change-Id: I7be2f0da4c2fe8f80a60bdde5e6c623d8bd5a0aa
2022-03-10 11:35:53 +00:00
Pedro Alves
cdff184f42 Fix gdb.threads/clone-new-thread-event.exp race
If we make GDB report the process EXIT event for the leader thread,
instead of whatever is the last thread in the LWP list, as will be
done in a latter patch of this series, then
gdb.threads/current-lwp-dead.exp starts failing:

 (gdb) FAIL: gdb.threads/clone-new-thread-event.exp: catch SIGUSR1 (the program exited)

This is a testcase race -- the main thread does not wait for the
spawned clone "thread" to finish before exiting, so the main program
may exit before the second thread is scheduled and reports its
SIGUSR1.  With the change to make GDB report the EXIT for the leader,
the race is 100% reproducible by adding a sleep(), like so:

 --- c/gdb/testsuite/gdb.threads/clone-new-thread-event.c
 +++ w/gdb/testsuite/gdb.threads/clone-new-thread-event.c
 @@ -51,6 +51,7 @@ local_gettid (void)
  static int
  fn (void *unused)
  {
 +  sleep (1);
    tkill (local_gettid (), SIGUSR1);
    return 0;
  }

Resulting in:

 Breakpoint 1, main (argc=1, argv=0x7fffffffd418) at gdb.threads/clone-new-thread-event.c:65
 65        stack = malloc (STACK_SIZE);
 (gdb) continue
 Continuing.
 [New LWP 3715562]
 [Inferior 1 (process 3715555) exited normally]
 (gdb) FAIL: gdb.threads/clone-new-thread-event.exp: catch SIGUSR1 (the program exited)

That inferior exit reported is actually correct.  The main thread has
indeed exited, and that's the thread that has the right exit code to
report to the user, as that's the exit code that is reported to the
program's parent.  In this case, GDB managed to collect the exit code
for the leader thread before reaping the other thread, because in
reality, the testcase isn't creating standard threads, it is using raw
clone, and the new clones are put in their own thread group.

Fix it by making the main thread wait for the child to exit.  Also,
run the program to completion for completeness.

Change-Id: I315cd3dc2b9e860395dcab9658341ea868d7a6bf
2022-03-10 11:35:53 +00:00
Pedro Alves
e48359eaa8 Fix gdbserver/linux target_waitstatus logging assert
Turning on debug output in gdbserver leads to an assertion failure if
gdbserver reports a non-signal event:

    [threads] wait_1: LWP 3273770: extended event with waitstatus status->kind = EXECD, execd_pathname = gdb.threads/non-ldr-exc-1/non-ldr-exc-1
    [threads] wait_1: Hit a non-gdbserver trap event.
  ../../src/gdbserver/../gdb/target/waitstatus.h:365: A problem internal to GDBserver has been detected.
  sig: Assertion `m_kind == TARGET_WAITKIND_STOPPED || m_kind == TARGET_WAITKIND_SIGNALLED' failed.

Fix it in the obvious way, using target_waitstatus::to_string(),
resulting in, for example:

  [threads] wait_1: ret = LWP 1542412.1542412, status->kind = STOPPED, sig = GDB_SIGNAL_TRAP

Change-Id: Ia4832f9b4fa39f4af67fcaf21fd4d909a285a645
2022-03-10 11:35:53 +00:00
Nick Clifton
bed566bbf6 Add option to objdump/readelf to disable access to debuginfod servers.
* dwarf.c (use_debuginfod): New variable.  Set to 1.
	(load_separate_debug_info): Only call
	debuginfod_fetch_separate_debug_info is use_debuginfod is true.
	(dwarf_select_sections_by_names): Add do-not-use-debuginfod and
	use-debuginfod options.
	(dwarf_select_sections_by_letters): Add D and E options.
	* dwarf.h (use_debuginfod): New extern.
	* objdump.c (usage): Mention the new options.
	* readelf.c (usage): Likewise.
	* doc/binutils.texi: Document the new options.
	* doc/debug-options.texi: Describe the new options.
	* NEWS: Mention the new feature.
	* testsuite/binutils-all/debuginfod.exp: Add tests of the new
	options.
2022-03-10 09:11:40 +00:00
Alan Modra
d7c448293a Re: ld: Add a before_plugin_all_symbols_read hook
* testsuite/ld-plugin/pr28849.d: Adjust for powerpc64 function
	descriptors.
2022-03-10 16:06:12 +10:30
H.J. Lu
320fdefef1 ld: Add a before_plugin_all_symbols_read hook
Add a before_plugin_all_symbols_read hook to load symbol references from
DT_NEEDED entries, included from --copy-dt-needed-entries, before reading
plugin symbols to properly resolve plugin symbol references.

bfd/

	PR ld/28849
	* elf-bfd.h (elf_link_hash_table): Add handling_dt_needed.
	* elflink.c (_bfd_elf_merge_symbol): Don't set non_ir_ref_dynamic
	before plugin 'all symbols read' hook is called.

ld/

	PR ld/28849
	* ldelf.c (ldelf_handle_dt_needed): New function.
	(ldelf_before_plugin_all_symbols_read): Likewise.
	(ldelf_after_open): Call ldelf_handle_dt_needed.
	* ldelf.h (ldelf_before_plugin_all_symbols_read): New.
	* ldemul.c (ldemul_before_plugin_all_symbols_read): Likewise.
	* ldemul.h (ldemul_before_plugin_all_symbols_read): Likewise.
	(ld_emulation_xfer_struct): Add before_plugin_all_symbols_read.
	* ldlang.c (lang_process): Call
	ldemul_before_plugin_all_symbols_read before calling
	plugin_call_all_symbols_read.
	* emultempl/elf.em
	(gld${EMULATION_NAME}_before_plugin_all_symbols_read): New.
	(LDEMUL_BEFORE_PLUGIN_ALL_SYMBOLS_READ): New.
	* emultempl/emulation.em (ld_${EMULATION_NAME}_emulation):
	Initialize the before_plugin_all_symbols_read field.
	* testsuite/ld-plugin/lto.exp: Run PR ld/28849 tests.
	* testsuite/ld-plugin/pr28849.d: New file.
	* testsuite/ld-plugin/pr28849a.c: Likewise.
	* testsuite/ld-plugin/pr28849b.c: Likewise.
2022-03-09 18:23:43 -08:00
GDB Administrator
399f9ba236 Automatic date update in version.in 2022-03-10 00:00:14 +00:00
Hans-Peter Nilsson
7dc7323c0b toplevel: Makefile.def: Make configure-sim depend on all-readline
Without this, a "make all-sim" without the equivalent of
libreadline-dev installed on the build system, won't
properly pick up the in-tree readline build, and you'll see:

mkdir -p -- ./sim
Configuring in ./sim
configure: creating cache ./config.cache
checking build system type... x86_64-pc-linux-gnu
checking host system type... x86_64-pc-linux-gnu
checking target system type... cris-axis-elf
checking for x86_64-pc-linux-gnu-gcc... gcc
checking whether the C compiler works... yes
...
checking for library containing tgetent... -ltermcap
checking for readline in -lreadline... no
configure: error: the required "readline" library is missing
make[1]: *** [Makefile:11188: configure-sim] Error 1
make[1]: Leaving directory '/home/hp/sim/b'

The sim dependency on readline is apparently (nominally)
valid as there's a readline call in sim/erc32/sis.c.

2022-02-21  Hans-Peter Nilsson  <hp@axis.com>

	* Makefile.def (dependencies): Make configure-sim depend on
	all-readline.
2022-03-09 20:46:16 +01:00
Maciej W. Rozycki
befb57e516 GDB/testsuite: Fix a "displayed" typo in gdb.base/default.exp
Fix a typo, s/dislayed/displayed/ in default.exp at the top level.
2022-03-09 19:15:27 +00:00
Maciej W. Rozycki
19cf33a0d5 GDB/testsuite: Remove a stray backslash from gdb.base/settings.exp
Remove a stray trailing backslash from `test-integer' in settings.exp.
It is harmless as only white space follows in the next line before the
closing brace, so it merely swallows the newline character, but it may
look confusing to the reader.
2022-03-09 19:15:27 +00:00
Christina Schimpe
ec0e51aeee * gdb/doc/gdb.texinfo (Requirements): Fix a typo.
Copyright-paperwork-exempt: yes
2022-03-09 14:30:10 +02:00
Alan Modra
fb0e49d8e0 Constant fold view increment expressions
The idea here is to replace expressions like v + 1 + 1 + 1 with v + 3.

	* dwarf2dbg.c (set_or_check_view): Remove useless assertion.
	Resolve multiple view increments.
	* testsuite/gas/elf/dwarf2-18.d: Don't xfail mep.
2022-03-09 15:50:34 +10:30
Alan Modra
4afc889439 Reduce duplicated symbol_clone_if_forward_ref work
* symbol.c (struct symbol_flags): Add forward_resolved.
	(symbol_entry_find): Update needle initialisation.
	(symbol_clone_if_forward_ref): Do no work when forward_resolved
	is already set.  Set forward_resolved.
2022-03-09 14:10:00 +10:30
Aaron Merey
2e79bbf1e2 gdb: Try searching for auto-load script using .gnu_debuglink
If an auto-load script cannot be found and objfile is a separate
debuginfo whose filename does not match the name found in the parent
file's .gnu_debuglink section, then repeat the search using the
parent's filename where the last component is replaced with the
.gnu_debuglink name.

For example if the parent's filename is "/usr/lib/libxyz.so" and the
name in its .gnu_debuglink section is "libxyz.so.debug", then
if no auto-load script is otherwise found the search will be
repeated with the filename "/usr/lib/libxyz.so.debug".

This helps gdb locate auto-load scripts when debuginfo files do not have
the expected filename, such as when they are aquired from debuginfod.
2022-03-08 20:39:05 -05:00
GDB Administrator
2c5e3cf816 Automatic date update in version.in 2022-03-09 00:00:15 +00:00
Aaron Merey
9ac37a9ce6 PR gdb/27876 - debuginfod-downloaded source files don't pass proper fullname across mi / (gdb)info source
Source files downloaded from debuginfod currently use their original DWARF
filename as their "fullname".  This causes a mismatch between the fullname
and the actual location of the source file in the debuginfod client cache.

MI consumers such as VSCode will fail to open debuginfod-downloaded
source files due to this.  Also 'info source' will fail to include the
true paths of these files.

To fix this, use the debuginfod cache path as the fullname for debuginfod-
downloaded source files.
2022-03-08 15:37:01 -05:00
Jan Vrany
a9c82bc13c gdb/mi: preserve user selected thread and frame when invoking MI commands
Fix for PR gdb/20684.  When invoking MI commands with --thread and/or
--frame, the user selected thread and frame was not preserved:

  (gdb)
  info thread
  &"info thread\n"
  ~"  Id   Target Id                                           Frame \n"
  ~"* 1    Thread 0x7ffff7c30740 (LWP 19302) \"user-selected-c\" main () at /home/uuu/gdb/gdb/testsuite/gdb.mi/user-selected-context-sync.c:60\n"
  ~"  2    Thread 0x7ffff7c2f700 (LWP 19306) \"user-selected-c\" child_sub_function () at /home/uuu/gdb/gdb/testsuite/gdb.mi/user-selected-context-sync.c:30\n"
  ~"  3    Thread 0x7ffff742e700 (LWP 19307) \"user-selected-c\" child_sub_function () at /home/uuu/gdb/gdb/testsuite/gdb.mi/user-selected-context-sync.c:30\n"
  ^done
  (gdb)
  info frame
  &"info frame\n"
  ~"Stack level 0, frame at 0x7fffffffdf90:\n"
  ~" rip = 0x555555555207 in main (/home/uuu/gdb/gdb/testsuite/gdb.mi/user-selected-context-sync.c:60); saved rip = 0x7ffff7c5709b\n"
  ~" source language c.\n"
  ~" Arglist at 0x7fffffffdf80, args: \n"
  ~" Locals at 0x7fffffffdf80, Previous frame's sp is 0x7fffffffdf90\n"
  ~" Saved registers:\n "
  ~" rbp at 0x7fffffffdf80, rip at 0x7fffffffdf88\n"
  ^done
  (gdb)
  -stack-info-depth --thread 3
  ^done,depth="4"
  (gdb)
  info thread
  &"info thread\n"
  ~"  Id   Target Id                                           Frame \n"
  ~"  1    Thread 0x7ffff7c30740 (LWP 19302) \"user-selected-c\" main () at /home/uuu/gdb/gdb/testsuite/gdb.mi/user-selected-context-sync.c:60\n"
  ~"  2    Thread 0x7ffff7c2f700 (LWP 19306) \"user-selected-c\" child_sub_function () at /home/uuu/gdb/gdb/testsuite/gdb.mi/user-selected-context-sync.c:30\n"
  ~"* 3    Thread 0x7ffff742e700 (LWP 19307) \"user-selected-c\" child_sub_function () at /home/uuu/gdb/gdb/testsuite/gdb.mi/user-selected-context-sync.c:30\n"
  ^done
  (gdb)
  info frame
  &"info frame\n"
  ~"Stack level 0, frame at 0x7ffff742dee0:\n"
  ~" rip = 0x555555555169 in child_sub_function (/home/uuu/gdb/gdb/testsuite/gdb.mi/user-selected-context-sync.c:30); saved rip = 0x555555555188\n"
  ~" called by frame at 0x7ffff742df00\n"
  ~" source language c.\n"
  ~" Arglist at 0x7ffff742ded0, args: \n"
  ~" Locals at 0x7ffff742ded0, Previous frame's sp is 0x7ffff742dee0\n"
  ~" Saved registers:\n "
  ~" rbp at 0x7ffff742ded0, rip at 0x7ffff742ded8\n"
  ^done
  (gdb)

This caused problems for frontends that provide access to CLI because UI
may silently change the context for CLI commands (as demonstrated above).

This commit fixes the problem by restoring thread and frame in
mi_cmd_execute (). With this change, there are only two GDB/MI commands
that can change user selected context: -thread-select and -stack-select-frame.
This allows us to remove all and rather complicated logic of notifying
about user selected context change from mi_execute_command (), leaving it
to these two commands themselves to notify.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=20684
2022-03-08 16:55:37 +00:00
Andrew Burgess
807310c5c7 gdb: announce upcoming removal of Python 2 support from gdb
As has been discussed here:

  https://sourceware.org/pipermail/gdb-patches/2022-January/184910.html

Python 2 support will be removed from GDB after GDB 12 has branched.
This commit places an entry in the NEWS file to inform users of this
decision.
2022-03-08 13:42:16 +00:00
GDB Administrator
30732ea06d Automatic date update in version.in 2022-03-08 00:00:25 +00:00
Andrew Burgess
f99e1c6dc8 gdb/testsuite: add new test for comparing char types in Python
There's an interesting property of the 'char' type in C and C++, the
three types 'char', 'unsigned char', and 'signed char', are all
considered distinct.

In contrast, and 'int' is signed by default, and so 'int' and 'signed
int' are considered the same type.

This commit adds a test to ensure that this edge case is visible to a
user from Python.

It is worth noting that for any particular compiler implementation (or
the flags a compiler was invoked with), a 'char' will be either signed
or unsigned; it has to be one or the other, and a user can access this
information by using the Type.is_signed property.  However, for
something like function overload resolution, the 'char' type is
considered distinct from the signed and unsigned variants.

There's no change to GDB with this commit, this is just adding a new
test to guard some existing functionality.
2022-03-07 19:42:08 +00:00
Andrew Burgess
551b380fbd gdb/python: add Type.is_signed property
Add a new read-only property, Type.is_signed, which is True for signed
types, and False otherwise.

This property should only be read on types for which Type.is_scalar is
true, attempting to read this property for non-scalar types will raise
a ValueError.

I chose 'is_signed' rather than 'is_unsigned' in order to match the
existing Architecture.integer_type method, which takes a 'signed'
parameter.  As far as I could find, that was the only existing
signed/unsigned selector in the Python API, so it seemed reasonable to
stay consistent.
2022-03-07 19:42:08 +00:00
Andrew Burgess
ee6a3d9e94 gdb/python: add Type.is_scalar property
Add a new read-only property which is True for scalar types,
otherwise, it's False.
2022-03-07 19:42:07 +00:00
Andrew Burgess
6fd90137e7 gdb/mi: add --no-connection to MI -add-inferior command
Following on from the previous commit, where the -add-inferior command
now uses the same connection as the current inferior, this commit adds
a --no-connection option to -add-inferior.

This new option matches the existing option of the same name for the
CLI version of add-inferior; the new inferior is created with no
connection.

I've added a new 'connection' field to the MI output of -add-inferior,
which includes the connection number and short name.  I haven't
included the longer description field, this is the MI after all.  My
expectation would be that if the frontend wanted to display all the
connection details then this would be looked up from 'info
connection' (or the MI equivalent if/when such a command is added).

The existing -add-inferior tests are updated, as are the docs.
2022-03-07 19:39:04 +00:00
Umair Sair
d43bd54d54 gdb/mi: fix regression in mi -add-inferior command
Prior to the multi-target support commit:

  commit 5b6d1e4fa4
  Date:   Fri Jan 10 20:06:08 2020 +0000

      Multi-target support

When a new inferior was added using the MI -add-inferior command, the
new inferior would be using the same target as all the other
inferiors.  This makes sense, GDB only supported a single target stack
at a time.

After the above commit, each inferior has its own target stack.

To maintain backward compatibility, for the CLI add-inferior command,
when a new inferior is added the above commit has the new inferior
inherit a copy of the target stack from the current inferior.

Unfortunately, this same backward compatibility is missing for the MI.

This commit fixes this oversight.

Now, when the -add-inferior MI command is used, the new inferior will
inherit a copy of the target stack from the current inferior.
2022-03-07 19:38:53 +00:00
Tom Tromey
cfeab26e4d Deprecate dbx mode
GDB has a dbx emulation mode that adds a few aliases and helper
commands.  This mode is barely documented and is very superficial
besides.  I suspect it is rarely used, and I would like to propose
deprecating it for GDB 12, and then removing it in GDB 13.
2022-03-07 10:43:42 -07:00
Pedro Alves
3db1354160 Remove unnecessary inferior lookup in infrun:handle_one
infrun.c:handle_one calls find_inferior_ptid unnecessarily, since we
already have a thread pointer handy, and the thread has a pointer to
the inferior.  This commit removes the unnecessary lookup.

Change-Id: I2ae18601dd75346c6c91068e9a4f9a6484fb3339
2022-03-07 16:28:57 +00:00
Tom Tromey
aacf24b4db Fix bug in ada_print_floating
ada_print_floating rewrites a floating-point string representation to
conform to Ada syntax.  However, if you managed to get a floating
point error, you might see:

    (gdb) print whatever
    $2 = <invalid float valu.0e>

What's happening here is that ada_print_floating doesn't recognize
this error case, and proceeds to modify the error text.

This patch fixes this problem.
2022-03-07 08:27:38 -07:00
Tom Tromey
63fc2437de Implement real literal extension for Ada
Sometimes it is convenient to be able to specify the exact bits of a
floating-point literal.  For example, you may want to set a
floating-point register to a denormalized value, or to a particular
NaN.

In C, you can do this by combining the "{}" cast with an array
literal, like:

    (gdb) p {double}{0x576488BDD2AE9FFE}
    $1 = 9.8765449999999996e+112

This patch adds a somewhat similar idea to Ada.  It extends the lexer
to allow "l" and "f" suffixes in a based literal.  The "f" indicates a
floating-point literal, and the "l"s control the size of the
floating-point type.

Note that this differs from Ada's based real literals.  I believe
those can also be used to control the bits of a floating-point value,
but they are a bit more cumbersome to use (simplest is binary but
that's also very lengthy).  Also, these aren't implemented in GDB.

I chose not to allow this extension to work with based integer
literals with exponents.  That didn't seem very useful.
2022-03-07 08:27:38 -07:00
Tom Tromey
c9bfa277e9 Fix Ada integer literals with exponents
While working on another patch, I noticed that Ada integer literals
with exponents did not work.  For example, with one form you get an
error:

    (gdb) print 8e2
    Invalid digit `e' in based literal

And with another form you get an incorrect value:

    (gdb) print 16#8#e2
    $2 = 8

This patch fixes the bugs and adds tests.
2022-03-07 08:25:11 -07:00
Tom Tromey
47a39c6e18 Fix gdb.ada/arrayptr.exp results
PR ada/28115 points out that gdb.ada/arrayptr.exp works with GNAT 12,
but fails with minimal encodings in earlier versions.

This patch updates the test to try to report the results correctly.  I
tried this with the Fedora 34 system gcc (GCC 11) and with a GCC 12
built from git trunk sometime relatively recently.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28115
2022-03-07 07:57:09 -07:00
Tom Tromey
315e4ebb4b Handle non-ASCII identifiers in Ada
Ada allows non-ASCII identifiers, and GNAT supports several such
encodings.  This patch adds the corresponding support to gdb.

GNAT encodes non-ASCII characters using special symbol names.

For character sets like Latin-1, where all characters are a single
byte, it uses a "U" followed by the hex for the character.  So, for
example, thorn would be encoded as "Ufe" (0xFE being lower case
thorn).

For wider characters, despite what the manual says (it claims
Shift-JIS and EUC can be used), in practice recent versions only
support Unicode.  Here, characters in the base plane are represented
using "Wxxxx" and characters outside the base plane using
"WWxxxxxxxx".

GNAT has some further quirks here.  Ada is case-insensitive, and GNAT
emits symbols that have been case-folded.  For characters in ASCII,
and for all characters in non-Unicode character sets, lower case is
used.  For Unicode, however, characters that fit in a single byte are
converted to lower case, but all others are converted to upper case.

Furthermore, there is a bug in GNAT where two symbols that differ only
in the case of "Y WITH DIAERESIS" (and potentially others, I did not
check exhaustively) can be used in one program.  I chose to omit
handling this case from gdb, on the theory that it is hard to figure
out the logic, and anyway if the bug is ever fixed, we'll regret
having a heuristic.

This patch introduces a new "ada source-charset" setting.  It defaults
to Latin-1, as that is GNAT's default.  This setting controls how "U"
characters are decoded -- W/WW are always handled as UTF-32.

The ada_tag_name_from_tsd change is needed because this function will
read memory from the inferior and interpret it -- and this caused an
encoding failure on PPC when running a test that tries to read
uninitialized memory.

This patch implements its own UTF-32-based case folder.  This avoids
host platform quirks, and is relatively simple.  A short Python
program to generate the case-folding table is included.  It simply
relies on whatever version of Unicode is used by the host Python,
which seems basically acceptable.

Test cases for UTF-8, Latin-1, and Latin-3 are included.  This
exercises most of the new code paths, aside from Y WITH DIAERESIS as
noted above.
2022-03-07 07:52:59 -07:00
Tom Tromey
ee3d464915 Define HOST_UTF32 in charset.h
rust-parse.c has a #define for the host-specific UTF-32 charset name.
A later patch needs the same thing, so this patch moves the definition
to charset.h for easier reuse.
2022-03-07 07:52:59 -07:00
Tom Tromey
c8b76e1ec3 Let phex and phex_nz handle sizeof_l==1
Currently, neither phex nor phex_nz handle sizeof_l==1 -- they let
this case fall through to the default case.  However, a subsequent
patch in this series needs this case to work correctly.

I looked at all calls to these functions that pass a 1 for the
sizeof_l parameter.  The only such case seems to be correct with this
change.
2022-03-07 07:52:59 -07:00
Tom Tromey
36f5ca535d Don't pre-size result string in ada_decode
Currently, ada_decode pre-sizes the output string, filling it with 'X'
characters.  However, it's a bit simpler and more flexible to let
std::string do the work here, and simply append characters to the
string as we go.  This turns out to be useful for a subsequent patch.
2022-03-07 07:52:59 -07:00
Tom Tromey
a320f135dd Simplify a regular expression in ada-lex.l
ada-lex.l uses "%option case-insensitive", so there is no need for
regular expressions to match upper case.
2022-03-07 07:52:59 -07:00
GDB Administrator
0daa5af85a Automatic date update in version.in 2022-03-07 00:00:11 +00:00
Maciej W. Rozycki
d17e797f5c MIPS/opcodes: Fix alias annotation for branch instructions
Correct issues with INSN2_ALIAS annotation for branch instructions:

- regular MIPS BEQZ/L and BNEZ/L assembly instructions are idioms for
  BEQ/L and BNE/L respectively with the `rs' operand equal to $0,

- microMIPS 32-bit BEQZ and BNEZ assembly instructions are idioms for
  BEQ and BNE respectively with the `rt' operand equal to $0,

- regular MIPS BAL assembly instruction is an idiom for architecture
  levels of up to the MIPSr5 ISA and a machine instruction on its own
  from the MIPSr6 ISA up.

Add missing annotation to BEQZ/L and BNEZ/L accordingly then and add a
new entry for BAL for the MIPSr6 ISA, correcting a disassembly bug:

$ mips-linux-gnu-objdump -m mips:isa64r6 -M no-aliases -d bal.o

bal.o:     file format elf32-tradlittlemips

Disassembly of section .text:

00000000 <foo>:
   0:	04110000 	0x4110000
	...
$

Add test cases accordingly.

Parts for regular MIPS BEQZ/L and BNEZ/L instructions from Sagar Patel.

2022-03-06  Maciej W. Rozycki  <macro@orcam.me.uk>

	binutils/
	* testsuite/binutils-all/mips/mips1-branch-alias.d: New test.
	* testsuite/binutils-all/mips/mips1-branch-noalias.d: New test.
	* testsuite/binutils-all/mips/mips2-branch-alias.d: New test.
	* testsuite/binutils-all/mips/mips2-branch-noalias.d: New test.
	* testsuite/binutils-all/mips/mips32r6-branch-alias.d: New test.
	* testsuite/binutils-all/mips/mips32r6-branch-noalias.d: New
	test.
	* testsuite/binutils-all/mips/micromips-branch-alias.d: New
	test.
	* testsuite/binutils-all/mips/micromips-branch-noalias.d: New
	test.
	* testsuite/binutils-all/mips/mips-branch-alias.s: New test
	source.
	* testsuite/binutils-all/mips/micromips-branch-alias.s: New test
	source.
	* testsuite/binutils-all/mips/mips.exp: Run the new tests.

2022-03-06  Sagar Patel  <sagarmp@cs.unc.edu>
	    Maciej W. Rozycki  <macro@orcam.me.uk>

	opcodes/
	* mips-opc.c (mips_builtin_opcodes): Fix INSN2_ALIAS annotation
	for "bal", "beqz", "beqzl", "bnez" and "bnezl" instructions.
	* micromips-opc.c (micromips_opcodes): Likewise for "beqz" and
	"bnez" instructions.
2022-03-06 18:30:58 +00:00
Tom Tromey
13835d88dc Use function view when iterating over block symbols
This changes iterate_over_block_local_vars and
iterate_over_block_arg_vars to take a gdb::function_view rather than a
function pointer and a user-data.  In one spot, this allows us to
remove a helper structure and helper function.  In another spot, this
looked more complicated, so I changed the helper function to be an
"operator()" -- also a simplification, just not as big.
2022-03-06 10:50:42 -07:00
Tom Tromey
abed5aa88a Simplify hppa-tdep.c use of objfile_key
I happened to notice a couple of unnecessary casts in hppa-tdep.c, and
then I saw that the use of objfile_key could be simplified -- removing
some code and using the default deleter rather than noop_deleter.

Tested by rebuilding.  Let me know what you think.
2022-03-06 10:20:31 -07:00
Simon Marchi
5f8ab46bc6 gdb: constify parameter of value_copy
In a following patch, I have a const value I want to copy using a
value_copy.  However, value_copy takes a non-const source value, at the
moment.  Change the paramter to be const,

If the source value is not lazy, we currently call
value_contents_all_raw, which calls allocate_value_contents, to get a
view on the contents.  They both take a non-const value, that's a
problem.  My first attempt at solving it was to add a const version of
value_contents_all_raw, make allocate_value_contents take a const value,
and either:

 - make value::contents mutable
 - make allocate_value_contents cast away the const

The idea being that allocating the value contents buffer does modify the
value at the bit level, but logically that doesn't change its state.

That was getting a bit complicated, so what I ended up doing is make
value_copy not call value_contents_all_raw.  We know at this point that
the value is not lazy, so value::contents must have been allocate
already.

Change-Id: I3741ab362bce14315f712ec24064ccc17e3578d4
2022-03-06 11:33:23 -05:00
Simon Marchi
7055fa96fc gdb: remove internalvar_funcs::destroy
No kind of internal var uses it remove it.  This makes the transition to
using a variant easier, since we don't need to think about where this
should be called (in a destructor or not), if it can throw, etc.

Change-Id: Iebbc867d1ce6716480450d9790410d6684cbe4dd
2022-03-06 11:32:25 -05:00
GDB Administrator
7a1550fcec Automatic date update in version.in 2022-03-06 00:00:25 +00:00
GDB Administrator
7c28e7424d Automatic date update in version.in 2022-03-05 00:00:25 +00:00
Tom Tromey
c836575a6f Mark vDSO as not a file
The vDSO objfile is not a real file, so mark it as such.  I noticed
this because, when playing with debuginfod, I saw:

Downloading 0.01 MB separate debug info for /tmp/system-supplied DSO at 0x7ffff7fc9000

That "/tmp" is wrong -- it's just gdb's cwd.  This patch corrects the
problem, resulting in:

Downloading 0.01 MB separate debug info for system-supplied DSO at 0x7ffff7fc9000

Regression tested on x86-64 Fedora 34.
2022-03-04 12:35:33 -07:00
Simon Marchi
84a9f19530 binutils/readelf: fix indentation in process_dynamic_section
Clangd shows a warning about misleading indentation in this file, fix
it.

binutils/ChangeLog:

	* readelf.c (process_dynamic_section): Fix indentation.

Change-Id: I43a7f4f4c75dd080af614222b980526f5debf297
2022-03-04 10:57:14 -05:00