The next commit updates command-def-selftests.c to detect missing
or wrong prefix commands in a list of subcommands.
This command structure selftest detects a series of problems
that are fixed by this commit.
Many commands have a null prefix command, e.g.
(gdb) maintenance selftest command_str
Running selftest command_structure_invariants.
list 0x560417949cb8 reachable via prefix 'append binary '. command 'memory' has null prefixcmd
list 0x560417949cb8 reachable via prefix 'append binary '. command 'value' has null prefixcmd
...
Most of these are fixed by the following changes:
* do_add_cmd searches the prefix command having the list
in which the command is added.
This ensures that a command defined after its prefix command
gets the correct prefix command.
* Due to the GDB initialization order, a GDB file can define
a subcommand before the prefix command is defined.
So, have add_prefix_cmd calling a new recursive function
'update_prefix_field_of_prefix_commands' to set the prefix
command of all sub-commands that are now reachable from
this newly defined prefix command. Note that this recursive
call replaces the function 'set_prefix_cmd' that was providing
a partial solution to this problem.
Following that, 2 python commands (defined after all the other GDB
commands) got a wrong prefix command, e.g. "info frame-filter" has
as prefix command the "i" alias of "info". This is fixed by having
lookup_cmd_for_prefixlist returning the aliased command rather than
the alias.
After that, one remaining problem:
(gdb) maintenance selftest command_str
Running selftest command_structure_invariants.
list 0x55f320272298 reachable via prefix 'set remote '. command 'system-call-allowed' has null prefixcmd
Self test failed: self-test failed at ../../classfix/gdb/unittests/command-def-selftests.c:196
Ran 1 unit tests, 1 failed
(gdb)
Caused by initialize_remote_fileio that was taking the address of
its arguments remote_set_cmdlist and remote_show_cmdlist instead
of receiving the correct values to use as list.
2020-05-15 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* cli/cli-decode.c (lookup_cmd_for_prefix): Return the aliased command
as prefix, not one of its aliases.
(set_cmd_prefix): Remove.
(do_add_cmd): Centralize the setting of the prefix of a command, when
command is defined after its full chain of prefix commands.
(add_alias_cmd): Remove call to set_cmd_prefix, as do_add_cmd does it.
(add_setshow_cmd_full): Likewise.
(update_prefix_field_of_prefixed_commands): New function.
(add_prefix_cmd): Replace non working call to set_cmd_prefix by
update_prefix_field_of_prefixed_commands.
* gdb/remote-fileio.c (initialize_remote_fileio): Use the real
addresses of remote_set_cmdlist and remote_show_cmdlist given
as argument, not the address of an argument.
* gdb/remote-fileio.h (initialize_remote_fileio): Likewise.
* gdb/remote.c (_initialize_remote): Likewise.
When an alias name starts with the name of another alias,
GDB was accepting to define the aliases in one order (short first, long after),
but refused it the other way around.
So, fix the logic to recognise an already existing alias by using
lookup_cmd_composition.
Also, this revealed a bug in lookup_cmd_composition:
when the searched command is a prefix command, lookup_cmd_composition
was not returning the fact that a command was found even if the
TEXT to parse was fully consumed.
gdb/ChangeLog
YYYY-MM-DD Philippe Waroquiers <philippe.waroquiers@skynet.be>
* cli/cli-cmds.c (alias_command): Check for an existing alias
using lookup_cmd_composition, as valid_command_p is too strict
and forbids aliases that are the prefix of an existing alias
or command.
* cli/cli-decode.c (lookup_cmd_composition): Ensure a prefix
command is properly recognised as a valid command.
gdb/testsuite/ChangeLog
2020-05-15 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* gdb.base/alias.exp: Test aliases starting with a prefix of
another alias.
The GDB data structure that records the GDB commands is made of
'struct cmd_list_element' defined in cli-decode.h.
A cmd_list_element has various pointers to other cmd_list_element structures,
All these pointers are together building a graph of commands.
However, when following the 'next' and '*prefixlist' pointers of
cmd_list_element, the structure must better be a tree.
If such pointers do not form a tree, then some other elements of
cmd_list_element cannot get a correct semantic. In particular, the prefixname
has no correct meaning if the same prefix command can be reached via 2 different
paths.
This commit introduces a selftest that detects (at least some cases of) errors
leading to 'next' and '*prefixlist' not giving a tree structure.
The new 'command_structure_invariants' selftest detects one single case where
the command structure is not a tree:
(gdb) maintenance selftest command_structure_invariants
Running selftest command_structure_invariants.
list 0x56362e204b98 duplicated, reachable via prefix 'show ' and 'info set '. Duplicated list first command is 'ada'
Self test failed: self-test failed at ../../classfix/gdb/unittests/command-def-selftests.c:160
Ran 1 unit tests, 1 failed
(gdb)
This was fixed by the previous commit.
2020-05-15 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* unittests/help-doc-selftests.c: Rename to
unittests/command-def-selftests.c
* unittests/command-def-selftests.c (help_doc_tests): Update some
comments.
(command_structure_tests, traverse_command_structure): New namespace
and function.
(command_structure_invariants_tests): New function.
(_initialize_command_def_selftests) Renamed from
_initialize_help_doc_selftests, register command_structure_invariants
selftest.
The next commit introduces a selftest that detects when the GDB
command structure does not define a tree when using the pointers
'next/*prefixlist'. This test detects one such case, fixed
by this commit.
The command 'info set' was defined as a specific prefix command,
but re-using the command list already used for the 'show' command.
This leads to the command tree 'next/*prefixlist' to not be a tree.
This change defines 'info set ' as an alias, thereby fixing the selftest.
2020-05-15 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* cli/cli-cmds.c (_initialize_cli_cmds): Define 'info set' as
an alias of 'show'.
The purpose of this patch is to prepare for the future where
fixed point types become described using standard DWARF info,
rather than GNAT encodings. For that, we rename a number of
routines manipulating Ada fixed point types to make it explicit
from their new names that they rely on the GNAT encodings to work.
This will allow us, when we introduce support for fixed point types
from standard DWARF to use names that are not ambiguous with
the functions that do similar work, but only for GNAT encodings.
gdb/ChangeLog:
* ada-lang.h: (ada_is_gnat_encoded_fixed_point_type): Renames
ada_is_fixed_point_type. Update all callers.
(gnat_encoded_fixed_point_delta): Renames ada_delta. Update
all callers.
* ada-lang.c (gnat_encoded_fixed_type_info): Renames fixed_type_info.
Update all callers.
* ada-typeprint.c (print_gnat_encoded_fixed_point_type): Renames
print_fixed_point_type. Update all callers.
* ada-valprint.c (ada_value_print_num): Replace call to
ada_is_fixed_point_type by ada_is_gnat_encoded_fixed_point_type.
Some Intel processors implement a Branch Trace Store (BTS) which GDB
uses for reverse execution support via the "record btrace bts"
command.
I have been unable to find a description of a similar feature in a
recent (April 2020) AMD64 architecture reference:
https://www.amd.com/system/files/TechDocs/40332.pdf
While it is the case that AMD processors have an LBR (last branch
record) bit in the DebugCtl MSR, it seems that it affects only four
MSRs when enabled. The names of these MSRs are LastBranchToIP,
LastBranchFromIP, LastIntToIP, and LastIntFromIP. I can find no
mention of anything more extensive. While looking at an Intel
architecture document, I noticed that Intel's P6 family from the
mid-90s had registers of the same name.
Therefore...
This commit disables "record btrace bts" support in GDB for AMD
processors.
Using the test case from gdb.base/break.exp, the sessions
below show the expected behavior (run on a machine with an
Intel processor) versus that on a machine with an AMD processor.
The AMD processor in question is reported as follows by "lscpu":
AMD Ryzen Threadripper 2950X 16-Core Processor . Finally, I'll
note that the AMD machine is actually a VM, but I see similar
behavior on both the virtualization host and the VM.
Intel machine - Desired behavior:
[kevinb@mohave gdb]$ ./gdb -q testsuite/outputs/gdb.base/break/break
Reading symbols from testsuite/outputs/gdb.base/break/break...
(gdb) start
Temporary breakpoint 1 at 0x401179: file /home/kevinb/sourceware-git/native-build/bld/../../binutils-gdb/gdb/testsuite/gdb.base/break.c, line 43.
Starting program: /home/kevinb/sourceware-git/native-build/bld/gdb/testsuite/outputs/gdb.base/break/break
Temporary breakpoint 1, main (argc=1, argv=0x7fffffffd748, envp=0x7fffffffd758)
at /home/kevinb/sourceware-git/native-build/bld/../../binutils-gdb/gdb/testsuite/gdb.base/break.c:43
43 if (argc == 12345) { /* an unlikely value < 2^16, in case uninited */ /* set breakpoint 6 here */
(gdb) record btrace
(gdb) b factorial
Breakpoint 2 at 0x40121b: file /home/kevinb/sourceware-git/native-build/bld/../../binutils-gdb/gdb/testsuite/gdb.base/break.c, line 63.
(gdb) c
Continuing.
Breakpoint 2, factorial (value=6)
at /home/kevinb/sourceware-git/native-build/bld/../../binutils-gdb/gdb/testsuite/gdb.base/break.c:63
63 if (value > 1) { /* set breakpoint 7 here */
(gdb) info record
Active record target: record-btrace
Recording format: Branch Trace Store.
Buffer size: 64kB.
Recorded 768 instructions in 22 functions (0 gaps) for thread 1 (process 19215).
(gdb) record function-call-history
13 do_lookup_x
14 _dl_lookup_symbol_x
15 _dl_fixup
16 _dl_runtime_resolve_xsavec
17 atoi
18 strtoq
19 ____strtoll_l_internal
20 atoi
21 main
22 factorial
(gdb) record instruction-history
759 0x00007ffff7ce0917 <____strtoll_l_internal+647>: pop %r15
760 0x00007ffff7ce0919 <____strtoll_l_internal+649>: retq
761 0x00007ffff7cdd064 <atoi+20>: add $0x8,%rsp
762 0x00007ffff7cdd068 <atoi+24>: retq
763 0x00000000004011b1 <main+75>: mov %eax,%edi
764 0x00000000004011b3 <main+77>: callq 0x401210 <factorial>
765 0x0000000000401210 <factorial+0>: push %rbp
766 0x0000000000401211 <factorial+1>: mov %rsp,%rbp
767 0x0000000000401214 <factorial+4>: sub $0x10,%rsp
768 0x0000000000401218 <factorial+8>: mov %edi,-0x4(%rbp)
AMD machine - Wrong behavior:
[kev@f32-1 gdb]$ ./gdb -q testsuite/outputs/gdb.base/break/break
Reading symbols from testsuite/outputs/gdb.base/break/break...
(gdb) start
Temporary breakpoint 1 at 0x401179: file /ironwood1/sourceware-git/f32-master/bld/../../worktree-master/gdb/testsuite/gdb.base/break.c, line 43.
Starting program: /mesquite2/sourceware-git/f32-master/bld/gdb/testsuite/outputs/gdb.base/break/break
Temporary breakpoint 1, main (argc=1, argv=0x7fffffffd5b8, envp=0x7fffffffd5c8)
at /ironwood1/sourceware-git/f32-master/bld/../../worktree-master/gdb/testsuite/gdb.base/break.c:43
43 if (argc == 12345) { /* an unlikely value < 2^16, in case uninited */ /* set breakpoint 6 here */
(gdb) record btrace
(gdb) b factorial
Breakpoint 2 at 0x40121b: file /ironwood1/sourceware-git/f32-master/bld/../../worktree-master/gdb/testsuite/gdb.base/break.c, line 63.
(gdb) c
Continuing.
Breakpoint 2, factorial (value=6)
at /ironwood1/sourceware-git/f32-master/bld/../../worktree-master/gdb/testsuite/gdb.base/break.c:63
63 if (value > 1) { /* set breakpoint 7 here */
(gdb) info record
Active record target: record-btrace
Recording format: Branch Trace Store.
Buffer size: 64kB.
warning: Recorded trace may be incomplete at instruction 7737 (pc = 0x405000).
warning: Recorded trace may be incomplete at instruction 7739 (pc = 0x0).
Recorded 7740 instructions in 46 functions (2 gaps) for thread 1 (process 1402911).
(gdb) record function-call-history
37 ??
38 values
39 some_enum_global
40 ??
41 some_union_global
42 some_variable
43 ??
44 [decode error (2): unknown instruction]
45 ??
46 [decode error (2): unknown instruction]
(gdb) record instruction-history
7730 0x0000000000404ff3: add %al,(%rax)
7731 0x0000000000404ff5: add %al,(%rax)
7732 0x0000000000404ff7: add %al,(%rax)
7733 0x0000000000404ff9: add %al,(%rax)
7734 0x0000000000404ffb: add %al,(%rax)
7735 0x0000000000404ffd: add %al,(%rax)
7736 0x0000000000404fff: .byte 0x0
7737 0x0000000000405000: Cannot access memory at address 0x405000
Lastly, I'll note that I see a lot of gdb.btrace failures without
this commit. Worse still, the results aren't always the same which
causes a lot of noise when comparing test results.
gdbsupport/ChangeLog:
* btrace-common.h (btrace_cpu_vendor): Add CV_AMD.
gdb/ChangeLog:
* nat/linux-btrace.c (btrace_this_cpu): Add check for AMD
processors.
(cpu_supports_bts): Add CV_AMD case.
[Simon: I send this patch on behalf of Laurent Morichetti, I added the
commit message and performance measurement stuff.
Also, this patch is better viewed with "git show -w".]
stop_all_threads, in infrun.c, is used to stop all running threads on
targets that are always non-stop. It's used, for example, when the
program hits a breakpoint while GDB is set to "non-stop off". It sends
a stop request for each running thread, then collects one wait event for
each.
Since new threads can spawn while we are stopping the threads, it's
written in a way where it makes multiple such "send stop requests to
running threads & collect wait events" passes. The function completes
when it has made two passes where it hasn't seen any running threads.
With the way it's written right now is, it iterates on the thread list,
sending a stop request for each running thread. It then waits for a
single event, after which it iterates through the thread list again. It
sends stop requests for any running threads that's been created since
the last iteration. It then consumes another single wait event.
This makes it so we iterate on O(n^2) threads in total, where n is the
number of threads. This patch changes the function to reduce it to
O(n). This starts to have an impact when dealing with multiple
thousands of threads (see numbers below). At each pass, we know the
number of outstanding stop requests we have sent, for which we need to
collect a stop event. We can therefore loop to collect this many stop
events before proceeding to the next pass and iterate on the thread list
again.
To check the performance improvements with this patch, I made an
x86/Linux program with a large number of idle threads (varying from 1000
to 10000). The program's main thread hits a breakpoint once all these
threads have started, which causes stop_all_threads to be called to stop
all these threads. I measured (by patching stop_all_threads):
- the execution time of stop_all_threads
- the total number of threads we iterate on during the complete
execution of the function (the total number of times we execute the
"for (thread_info *t : all_non_exited_threads ())" loop)
These are the execution times, in milliseconds:
# threads before after
1000 226 106
2000 997 919
3000 3461 2323
4000 4330 3570
5000 8642 6600
6000 9918 8039
7000 12662 10930
8000 16652 11222
9000 21561 15875
10000 26613 20019
Note that I very unscientifically executed each case only once.
These are the number of loop executions:
# threads before after
1000 1003002 3003
2000 4006002 6003
3000 9009002 9003
4000 16012002 12003
5000 25015002 15003
6000 36018002 18003
7000 49021002 21003
8000 64024002 24003
9000 81027002 27003
10000 100030002 30003
This last table shows pretty well the O(n^2) vs O(n) behaviors.
Reg-tested on x86 GNU/Linux (Ubuntu 16.04).
gdb/ChangeLog:
YYYY-MM-DD Laurent Morichetti <Laurent.Morichetti@amd.com>
YYYY-MM-DD Simon Marchi <simon.marchi@efficios.com>
* infrun.c (stop_all_threads): Collect multiple wait events at
each pass.
Remove TYPE_CODE, changing all the call sites to use type::code
directly. This is quite a big diff, but this was mostly done using sed
and coccinelle. A few call sites were done by hand.
gdb/ChangeLog:
* gdbtypes.h (TYPE_CODE): Remove. Change all call sites to use
type::code instead.
Add the code and set_code methods on code, in order to remove the
TYPE_CODE macro. In this patch, the TYPE_CODE macro is changed to use
type::code, so all the call sites that are used to set the type code are
changed to use type::set_code. The next patch will remove TYPE_CODE
completely.
gdb/ChangeLog:
* gdbtypes.h (struct type) <code, set_code>: New methods.
(TYPE_CODE): Use type::code. Change all call sites used to set
the code to use type::set_code instead.
In stop_all_threads, GDB sends signals to other threads in an attempt
to stop them. While in a typical scenario the expected wait status is
TARGET_WAITKIND_STOPPED, it is possible that the thread GDB attempted
to stop has already terminated. If so, a waitstatus other than
TARGET_WAITKIND_STOPPED would be received. Handle this case
appropriately.
If a wait status that denotes thread termination is ignored, GDB goes
into an infinite loop in stop_all_threads.
E.g.:
$ gdb ./a.out
(gdb) start
...
(gdb) add-inferior -exec ./a.out
...
(gdb) inferior 2
...
(gdb) start
...
(gdb) set schedule-multiple on
(gdb) set debug infrun 2
(gdb) continue
Continuing.
infrun: clear_proceed_status_thread (process 10449)
infrun: clear_proceed_status_thread (process 10453)
infrun: proceed (addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT)
infrun: proceed: resuming process 10449
infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [process 10449] at 0x55555555514e
infrun: infrun_async(1)
infrun: prepare_to_wait
infrun: proceed: resuming process 10453
infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [process 10453] at 0x55555555514e
infrun: prepare_to_wait
infrun: Found 2 inferiors, starting at #0
infrun: target_wait (-1.0.0, status) =
infrun: 10449.10449.0 [process 10449],
infrun: status->kind = exited, status = 0
infrun: handle_inferior_event status->kind = exited, status = 0
[Inferior 1 (process 10449) exited normally]
infrun: stop_waiting
infrun: stop_all_threads
infrun: stop_all_threads, pass=0, iterations=0
infrun: process 10453 executing, need stop
infrun: target_wait (-1.0.0, status) =
infrun: 10453.10453.0 [process 10453],
infrun: status->kind = exited, status = 0
infrun: stop_all_threads status->kind = exited, status = 0 process 10453
infrun: process 10453 executing, already stopping
infrun: target_wait (-1.0.0, status) =
infrun: -1.0.0 [process -1],
infrun: status->kind = no-resumed
infrun: infrun_async(0)
infrun: stop_all_threads status->kind = no-resumed process -1
infrun: process 10453 executing, already stopping
infrun: stop_all_threads status->kind = no-resumed process -1
infrun: process 10453 executing, already stopping
infrun: stop_all_threads status->kind = no-resumed process -1
infrun: process 10453 executing, already stopping
infrun: stop_all_threads status->kind = no-resumed process -1
infrun: process 10453 executing, already stopping
infrun: stop_all_threads status->kind = no-resumed process -1
infrun: process 10453 executing, already stopping
infrun: stop_all_threads status->kind = no-resumed process -1
infrun: process 10453 executing, already stopping
infrun: stop_all_threads status->kind = no-resumed process -1
infrun: process 10453 executing, already stopping
infrun: stop_all_threads status->kind = no-resumed process -1
infrun: process 10453 executing, already stopping
infrun: stop_all_threads status->kind = no-resumed process -1
infrun: process 10453 executing, already stopping
infrun: stop_all_threads status->kind = no-resumed process -1
infrun: process 10453 executing, already stopping
...
And this polling goes on forever. This patch prevents the infinite
looping behavior. For the same scenario above, we obtain the
following behavior:
...
(gdb) continue
Continuing.
infrun: clear_proceed_status_thread (process 31229)
infrun: clear_proceed_status_thread (process 31233)
infrun: proceed (addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT)
infrun: proceed: resuming process 31229
infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [process 31229] at 0x55555555514e
infrun: infrun_async(1)
infrun: prepare_to_wait
infrun: proceed: resuming process 31233
infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [process 31233] at 0x55555555514e
infrun: prepare_to_wait
infrun: Found 2 inferiors, starting at #0
infrun: target_wait (-1.0.0, status) =
infrun: 31229.31229.0 [process 31229],
infrun: status->kind = exited, status = 0
infrun: handle_inferior_event status->kind = exited, status = 0
[Inferior 1 (process 31229) exited normally]
infrun: stop_waiting
infrun: stop_all_threads
infrun: stop_all_threads, pass=0, iterations=0
infrun: process 31233 executing, need stop
infrun: target_wait (-1.0.0, status) =
infrun: 31233.31233.0 [process 31233],
infrun: status->kind = exited, status = 0
infrun: stop_all_threads status->kind = exited, status = 0 process 31233
infrun: saving status status->kind = exited, status = 0 for 31233.31233.0
infrun: process 31233 not executing
infrun: stop_all_threads, pass=1, iterations=1
infrun: process 31233 not executing
infrun: stop_all_threads done
(gdb)
The exit event from Inferior 1 is received and shown to the user.
The exit event from Inferior 2 is not displayed, but kept pending.
(gdb) info inferiors
Num Description Connection Executable
* 1 <null> a.out
2 process 31233 1 (native) a.out
(gdb) inferior 2
[Switching to inferior 2 [process 31233] (a.out)]
[Switching to thread 2.1 (process 31233)]
Couldn't get registers: No such process.
(gdb) continue
Continuing.
infrun: clear_proceed_status_thread (process 31233)
infrun: clear_proceed_status_thread: thread process 31233 has pending wait status status->kind = exited, status = 0 (currently_stepping=0).
infrun: proceed (addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT)
infrun: proceed: resuming process 31233
infrun: resume: thread process 31233 has pending wait status status->kind = exited, status = 0 (currently_stepping=0).
infrun: prepare_to_wait
infrun: Using pending wait status status->kind = exited, status = 0 for process 31233.
infrun: target_wait (-1.0.0, status) =
infrun: 31233.31233.0 [process 31233],
infrun: status->kind = exited, status = 0
infrun: handle_inferior_event status->kind = exited, status = 0
[Inferior 2 (process 31233) exited normally]
infrun: stop_waiting
(gdb) info inferiors
Num Description Connection Executable
1 <null> a.out
* 2 <null> a.out
(gdb)
When a process exits and we leave the process exit event pending, we
need to make sure that at least one thread is left listed in the
inferior's thread list. This is necessary in order to make sure we
have a thread that we can later resume, so the process exit event can
be collected/reported.
When native debugging, the GNU/Linux back end already makes sure that
the last LWP isn't deleted.
When remote debugging against GNU/Linux GDBserver, the GNU/Linux
GDBserver backend also makes sure that the last thread isn't deleted
until the process exit event is reported to GDBserver core.
However, between the backend reporting the process exit event to
GDBserver core, and GDB consuming the event, GDB may update the thread
list and find no thread left in the process. The process exit event
will be pending somewhere in GDBserver's stop reply queue, or
gdb/remote.c's queue, or whathever other event queue inbetween
GDBserver and infrun.c's handle_inferior_event.
This patch tweaks remote.c's target_update_thread_list implementation
to avoid deleting the last thread of an inferior.
In the past, this case of inferior-with-no-threads led to a special
case at the bottom of handle_no_resumed, where it reads:
/* Note however that we may find no resumed thread because the whole
process exited meanwhile (thus updating the thread list results
in an empty thread list). In this case we know we'll be getting
a process exit event shortly. */
for (inferior *inf : all_non_exited_inferiors (ecs->target))
In current master, that code path is still reachable with the
gdb.threads/continue-pending-after-query.exp testcase, when tested
against GDBserver, with "maint set target-non-stop" forced "on".
With this patch, the scenario that loop was concerned about is still
properly handled, because the loop above it finds the process's last
thread with "executing" set to true, and thus the handle_no_resumed
function still returns true.
Since GNU/Linux native and remote are the only targets that support
non-stop mode, and with this patch, we always make sure the inferior
has at least one thread, this patch also removes that "inferior with
no threads" special case handling from handle_no_resumed.
Since remote.c now has a special case where we treat a thread that has
already exited as if it was still alive, we might need to tweak
remote.c's target_thread_alive implementation to return true for that
thread without querying the remote side (which would say "no, not
alive"). After inspecting all the target_thread_alive calls in the
codebase, it seems that only the one from prune_threads could result
in that thread being accidentally deleted. There's only one call to
prune_threads in GDB's common code, so this patch handles this by
replacing the prune_threads call with a delete_exited_threads call.
This seems like an improvement anyway, because we'll still be doing
what the comment suggests we want to do, and, we avoid remote protocol
traffic.
Regression-tested on X86_64 Linux.
gdb/ChangeLog:
2020-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
Tom de Vries <tdevries@suse.de>
Pedro Alves <palves@redhat.com>
PR threads/25478
* infrun.c (stop_all_threads): Do NOT ignore
TARGET_WAITKIND_NO_RESUMED, TARGET_WAITKIND_THREAD_EXITED,
TARGET_WAITKIND_EXITED, TARGET_WAITKIND_SIGNALLED wait statuses
received.
(handle_no_resumed): Remove code handling a live inferior with no
threads.
* remote.c (has_single_non_exited_thread): New.
(remote_target::update_thread_list): Do not delete a thread if is
the last thread of the process.
* thread.c (thread_select): Call delete_exited_threads instead of
prune_threads.
gdb/testsuite/ChangeLog:
2020-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
Pedro Alves <palves@redhat.com>
* gdb.multi/multi-exit.c: New file.
* gdb.multi/multi-exit.exp: New file.
* gdb.multi/multi-kill.c: New file.
* gdb.multi/multi-kill.exp: New file.
In stop_all_threads, the thread events of the current top target are
enabled at the beginning of the function and then disabled at the end
(at scope exit time). Because there may be multiple targets whose
thread lists will be updated and whose threads are stopped,
enable/disable thread events for all targets.
This update caused a change in the annotations. In particular, a
"frames-invalid" annotation is printed one more time due to switching
the current inferior. Hence, gdb.base/annota1.exp and
gdb.cp/annota2.exp tests are also updated.
Regression-tested on X86_64 Linux using the default board file and the
native-extended-gdbserver board file.
gdb/ChangeLog:
2020-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* infrun.c (stop_all_threads): Enable/disable thread events of all
targets. Move a debug message denoting the end of the function
into the SCOPED_EXIT block.
gdb/testsuite/ChangeLog:
2020-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* gdb.base/annota1.exp: Update the expected output.
* gdb.cp/annota2.exp: Ditto.
Introduce two new convenience functions:
1. all_non_exited_process_targets: returns a collection of all process
stratum targets that have non-exited inferiors on them. Useful for
iterating targets.
2. switch_to_target_no_thread: switch the context to the first
inferior of the given target, and to no selected thread.
gdb/ChangeLog:
2020-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* process-stratum-target.h: Include <set>.
(all_non_exited_process_targets, switch_to_target_no_thread): New
function declarations.
* process-stratum-target.c (all_non_exited_process_targets)
(switch_to_target_no_thread): New function implementations.
This is a refactoring. The extracted function is placed deliberately
before 'stop_all_threads' because the function will be re-used there
in a subsequent patch for handling an exit status kind received from
a thread that GDB attempted to stop.
gdb/ChangeLog:
2020-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* infrun.c (handle_inferior_event): Extract out a piece of code
into...
(mark_non_executing_threads): ...this new function.
Change-Id: I2b088f4a724f4260cb37068264964525cf62a118
In infrun.c's resume_1 function, move the definition of the local
variable PC down to its first use. This is useful if the thread we want
to resume is already gone with a pending exit event, because we avoid
the error we would see otherwise when trying to read the PC.
gdb/ChangeLog:
2020-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* infrun.c (resume_1): Move a 'regcache_read_pc' call down to first
use.
It possible that a thread whose PC we attempt to read is already dead.
In this case, 'regcache_read_pc' errors out. This impacts the
"proceed" execution flow, where GDB quits early before having a chance
to check if there exists a pending event. To remedy, keep going with
a 0 value for the PC if 'regcache_read_pc' fails. Because the value
of PC before resuming a thread is mostly used for storing and checking
the next time the thread stops, this tolerance is expected to be
harmless for a dead thread/process.
gdb/ChangeLog:
2020-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* regcache.c (regcache_read_pc_protected): New function
implementation that returns 0 if the PC cannot read via
'regcache_read_pc'.
* infrun.c (proceed): Call 'regcache_read_pc_protected'
instead of 'regcache_read_pc'.
(keep_going_pass_signal): Ditto.
gdbsupport/ChangeLog:
2020-05-14 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* common-regcache.h (regcache_read_pc_protected): New function
declaration.
I recently noticed the align_value function in ada-lang.c. This can
be removed, in favor of align_up from gdbsupport.
gdb/ChangeLog
2020-05-13 Tom Tromey <tromey@adacore.com>
* ada-lang.c (align_value): Remove.
(ada_template_to_fixed_record_type_1): Use align_up.
The async-event.[ch] files were introduced recently as a result of
splitting the event-loop. I believe the copyright year update was
just an oversight. So, this patch fixes that.
gdb/ChangeLog:
2020-05-13 Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
* async-event.c: Update the copyright year.
* async-event.h: Update the copyright year.
As discussed on gdb-patches, this restores info_command and the
breakpoint on info_command in gdb-gdb.gdb. This reverts a tiny part
of 0743fc83c0 ("Replace most calls to help_list and cmd_show_list"),
as well as 652fc23a30 ("Remove gdb-gdb.gdb breakpoint on disappeared
function info_command.").
gdb/ChangeLog
2020-05-11 Tom Tromey <tromey@adacore.com>
* cli/cli-cmds.c (info_command): Restore.
(_initialize_cli_cmds): Use add_prefix_command for "info".
* gdb-gdb.gdb.in: Restore breakpoint on info_command.
The val_print removal patches introduced an Ada regression on PPC64
(probably any big-endian system).
The issue comes because value_field does not understand that Ada
wrapper fields can be bitfields that wrap a non-scalar type. In this
case the value is already left-justified, so the justification done
there does the wrong thing.
Perhaps it would be good, eventually, to change value_field to
understand this case. In the meantime this implements an Ada-specific
solution.
gdb/ChangeLog
2020-05-11 Tom Tromey <tromey@adacore.com>
* ada-lang.c (ada_value_primitive_field): Now public.
* ada-lang.h (ada_value_primitive_field): Declare.
* ada-valprint.c (print_field_values): Use
ada_value_primitive_field for wrapper fields.
When running test-case gdb.fortran/info-modules.exp with target board
debug-names, I run into:
...
FAIL: gdb.fortran/info-modules.exp: info modules: check for entry \
'info-types-2.f90', '18', 'mod2'
...
In more detail, comparing the behaviour of the executable without and with
.debug_names section, we have:
...
-$ gdb -batch info-modules -ex "info modules"
+$ gdb -batch info-modules.debugnames -ex "info modules"
All defined modules:
-File /data/gdb_versions/devel/src/gdb/testsuite/gdb.fortran/info-types-2.f90:
-18: mod2
-
File /data/gdb_versions/devel/src/gdb/testsuite/gdb.fortran/info-types.f90:
16: mod1
...
This is due to the fact that the .debug_names section does not contain
DW_TAG_module entries.
Fix this in debug_names::psymbol_tag.
Build and tested on x86_64-linux with target board debug-names.
gdb/ChangeLog:
2020-05-11 Tom de Vries <tdevries@suse.de>
* dwarf2/index-write.c (debug_names::psymbol_tag): Handle
MODULE_DOMAIN.
Consider the following two-file test-case:
...
$ cat main.c
extern int foo (void);
int
main (void)
{
int sum, a, b;
sum = a + b + foo ();
return sum;
}
$ cat foo.c
int
foo (void)
{
return 3;
}
...
Compiled like this:
...
$ clang-10 -gdwarf-5 -gpubnames -c main.c
$ clang-10 -gdwarf-5 -c foo.c
$ clang-10 -gdwarf-5 -gpubnames main.o foo.o
...
When loading this exec into gdb, we run into this assert:
...
$ gdb a.out
Reading symbols from a.out...
warning: Section .debug_aranges in a.out entry at offset 0 \
debug_info_offset 0 does not exists, ignoring .debug_aranges.
src/gdb/dwarf2/read.c:6949: \
internal-error: cutu_reader::cutu_reader(dwarf2_per_cu_data*, \
abbrev_table*, int, bool): \
Assertion `this_cu->length == cu->header.get_length ()' failed.
...
The problem is that the determined length of the CU:
...
(gdb) p /x this_cu->length
$4 = 0x26a
...
does not match the actual length:
...
(gdb) p /x cu->header.get_length ()
$5 = 0x59
...
The length of the CU is determined in create_cus_from_debug_names_list, and
set based on this list in the .debug_names section:
...
Compilation Unit offsets [
CU[0]: 0x000000c7
]
...
and it is assumed that this is a complete list, so the size of the CU is
calculated using the end of the .debug_section at 0x331, making it 0x331 -
0xc7 == 0x26a.
However, the CU list is not complete:
...
$ llvm-dwarfdump -debug-info a.out \
| grep "Compile Unit" \
| sed 's/Compile Unit.*//'
0x00000000:
0x0000002e:
0x000000a5:
0x000000c7:
0x00000120:
0x00000157:
0x0000030f:
...
In particular, because the CU for foo.c is there at 0x120 (the rest of the CUs
is due to openSUSE having debug info for various linked in objects).
Fix the assert by not assuming to know the length of CUs in
create_cus_from_debug_names_list (if the .debug_names is not produced by GDB),
and setting it to 0, and setting it later to the actual length.
Note that this does not fix the .debug_aranges warning, that's PR25969.
Build and tested on x86_64-linux, with native and debug-names.
gdb/ChangeLog:
2020-05-11 Tom de Vries <tdevries@suse.de>
PR symtab/25941
* dwarf2/read.c (create_cus_from_debug_names_list): Initialize CUs
with length 0, if not gdb-produced.
(cutu_reader::cutu_reader): Set CU length to actual length if 0.
gdb/testsuite/ChangeLog:
2020-05-11 Tom de Vries <tdevries@suse.de>
PR symtab/25941
* gdb.dwarf2/clang-debug-names.exp.in: New include exp file, factored
out of ...
* gdb.dwarf2/clang-debug-names.exp: ... here.
* gdb.dwarf2/clang-debug-names-2.exp: New file. Include
clang-debug-names.exp.in.
* gdb.dwarf2/clang-debug-names-2-foo.c: New test.
* gdb.dwarf2/clang-debug-names-2.c: New test.
When running test-case gdb.mi/mi-catch-cpp-exceptions.exp, we have:
...
FAIL: gdb.mi/mi-catch-cpp-exceptions.exp: all with invalid regexp: run until \
breakpoint in main (unknown output after running)
...
This is a regression since commit 596dc4adff "Speed up psymbol reading by
removing a copy".
Before that commit, we have:
...
$ gdb \
-batch \
./outputs/gdb.mi/mi-catch-cpp-exceptions/mi-catch-cpp-exceptions \
-ex "break 67" \
-ex "catch throw -r blahblah" \
-ex r
Breakpoint 1 at 0x4008e5: file mi-catch-cpp-exceptions.cc, line 67.
Catchpoint 2 (throw)
Breakpoint 1, main () at mi-catch-cpp-exceptions.cc:67
67 return 1; /* Stop here. */
...
In other words:
- we set a breakpoint somewhere in main,
- we set a catchpoint with a regexp that is intended to not match any
exception, and
- run to the breakpoint, without the catchpoint triggering.
After the commit, we have:
...
$ gdb \
-batch \
./outputs/gdb.mi/mi-catch-cpp-exceptions/mi-catch-cpp-exceptions \
-ex "break 67" \
-ex "catch throw -r blahblah" \
-ex r
Breakpoint 1 at 0x4008e5: file mi-catch-cpp-exceptions.cc, line 67.
Catchpoint 2 (throw)
Catchpoint 2 (exception thrown), 0x00007ffff7ab037e in __cxa_throw () from \
/usr/lib64/libstdc++.so.6
...
In other words, the catchpoint triggers.
This is caused by this bit of the commit:
...
type_name = cplus_typename_from_type_info (typeinfo_arg);
canon = cp_canonicalize_string (type_name.c_str ());
- if (!canon.empty ())
- std::swap (type_name, canon);
+ name = (canon == nullptr
+ ? canon.get ()
+ : type_name.c_str ());
}
catch (const gdb_exception_error &e)
{
exception_print (gdb_stderr, e);
}
- if (!type_name.empty ())
+ if (name != nullptr)
{
- if (self->pattern->exec (type_name.c_str (), 0, NULL, 0) != 0)
+ if (self->pattern->exec (name, 0, NULL, 0) != 0)
...
Before the commit, we have:
- type_name == "my_exception"
- canon = ""
and the !type_name.empty () test succeeds, and gdb executes the
self->pattern->exec call.
After the commit, we have:
- type_name == "my_exception"
- canon == NULL
- name == NULL
and the name != nullptr test fails, and gdb doesn't execute the
self->pattern->exec call.
Fix this by inverting the condition for the calculation of name:
...
- name = (canon == nullptr
+ name = (canon != nullptr
...
Build and tested on x86_64-linux.
gdb/ChangeLog:
2020-05-09 Tom de Vries <tdevries@suse.de>
PR gdb/25955
* break-catch-throw.c (check_status_exception_catchpoint): Fix name
calculation.
I noticed that "server_command" is an int, but really it should be a
bool.
gdb/ChangeLog
2020-05-09 Tom Tromey <tom@tromey.com>
* top.c (server_command): Now bool.
* top.h (server_command): Now bool.
A customer reported a crash in the DWARF reader.
Investigation showed that the crash occurred in an unusual scenario: a
function was lexically scoped within some other function -- but the
inner function inlined the outer function and referred to its DIE via
DW_AT_abstract_origin. With the executable in question,
inherit_abstract_dies could eventually call read_lexical_block_scope,
which in turn could recurse into process_die, to process a DIE that
was already being read, triggering an assert.
This came up once before; see:
https://www.sourceware.org/ml/gdb-patches/2014-02/msg00652.html
However, in this case, I don't have an easy way to reproduce. So,
there is no test case.
I did experiment with the failing executable. This patch fixes the
bug and doesn't seem to cause other issues. For example, I can still
set breakpoints on the relevant functions.
gdb/ChangeLog
2020-05-08 Tom Tromey <tromey@adacore.com>
* dwarf2/read.c (read_lexical_block_scope): Don't process a DIE
already being processed.
This changes displays to have a constructor, use bool and std::string,
and to be stored using std::vector. The ALL_DISPLAYS and
ALL_DISPLAYS_SAFE macros are removed. While internal iteration is
still done via map_display_numbers, this is updated to use a
function_view. These changes simplify the code somewhat; for example,
free_display can now be removed in favor of ordinary destruction.
gdb/ChangeLog
2020-05-08 Tom Tromey <tom@tromey.com>
* printcmd.c (struct display) <next>: Remove.
<display>: New constructor.
<exp_string>: Now a std::string.
<enabled_p>: Now a bool.
(display_number): Move definition earlier.
(displays): Rename from display_chain. Now a std::vector.
(ALL_DISPLAYS, ALL_DISPLAYS_SAFE): Remove.
(display_command): Update.
(do_one_display, disable_display)
(enable_disable_display_command, do_enable_disable_display):
Update.
(free_display): Remove.
(clear_displays): Rewrite.
(delete_display): Update.
(map_display_numbers): Use function_view. Remove "data"
parameter. Update.
(do_delete_display): Remove.
(undisplay_command): Update.
(do_one_display, do_displays, disable_display)
(info_display_command): Update.
(do_enable_disable_display): Remove.
(enable_disable_display_command)
(clear_dangling_display_expressions): Update.
This patch started as an attempt to replace ALL_SO_LIBS with an
ordinary C++ iterator. However, then I tripped over the so_list_head
define again, and decided to remove it as well.
gdb/ChangeLog
2020-05-08 Tom Tromey <tom@tromey.com>
* mi/mi-cmd-file.c (mi_cmd_file_list_shared_libraries): Update.
* solib-svr4.c (svr4_fetch_objfile_link_map): Update.
(enable_break): Update.
* solib-frv.c (frv_fdpic_find_global_pointer): Update.
(frv_fdpic_find_canonical_descriptor): Update.
(frv_fetch_objfile_link_map): Update.
* progspace.c (program_space::free_all_objfiles): Update.
(program_space::solibs): New method.
* progspace.h (struct program_space) <solibs>: New method.
* solist.h (master_so_list): Don't declare.
(ALL_SO_LIBS): Remove.
* solib.h (so_list_head): Remove.
(update_solib_list): Update comment.
* solib.c (master_so_list): Remove.
(solib_used, update_solib_list, solib_add)
(info_sharedlibrary_command, clear_solib)
(reload_shared_libraries_1, remove_user_added_objfile): Update.
This removes the ALL_EXTENSION_LANGUAGES and
ALL_ENABLED_EXTENSION_LANGUAGES macros, in favor of ordinary
iterators. For ALL_ENABLED_EXTENSION_LANGUAGES, I chose to simply
inline the check, as that seemed simpler than trying to make
filtered_iterator work for std::array. (As an aside, this sort of
thing will be easier once we can use the ranges library...)
gdb/ChangeLog
2020-05-08 Tom Tromey <tom@tromey.com>
* extension.c (extension_languages): Now a std::array.
(ALL_EXTENSION_LANGUAGES): Remove.
(get_ext_lang_defn, get_ext_lang_of_file)
(eval_ext_lang_from_control_command): Update.
(finish_ext_lang_initialization)
(auto_load_ext_lang_scripts_for_objfile)
(ext_lang_type_printers::ext_lang_type_printers)
(apply_ext_lang_type_printers)
(ext_lang_type_printers::~ext_lang_type_printers)
(apply_ext_lang_val_pretty_printer, apply_ext_lang_frame_filter)
(preserve_ext_lang_values, get_breakpoint_cond_ext_lang)
(breakpoint_ext_lang_cond_says_stop, check_quit_flag)
(get_matching_xmethod_workers, ext_lang_colorize)
(ext_lang_before_prompt): Update.
(ALL_ENABLED_EXTENSION_LANGUAGES): Remove.
I noticed that cp_canonicalize_string and friends copy a
unique_xmalloc_ptr to a std::string. However, this copy isn't
genuinely needed anywhere, and it serves to slow down DWARF psymbol
reading.
This patch removes the copy and updates the callers to adapt.
This speeds up the reader from 1.906 seconds (mean of 10 runs, of gdb
on a copy of itself) to 1.888 seconds (mean of 10 runs, on the same
copy as the first trial).
gdb/ChangeLog
2020-05-08 Tom Tromey <tom@tromey.com>
* symtab.h (class demangle_result_storage) <set_malloc_ptr>: New
overload.
<swap_string, m_string>: Remove.
* symtab.c (demangle_for_lookup, completion_list_add_symbol):
Update.
* stabsread.c (define_symbol, read_type): Update.
* linespec.c (find_linespec_symbols): Update.
* gnu-v3-abi.c (gnuv3_get_typeid): Update.
* dwarf2/read.c (dwarf2_canonicalize_name): Update.
* dbxread.c (read_dbx_symtab): Update.
* cp-support.h (cp_canonicalize_string_full)
(cp_canonicalize_string, cp_canonicalize_string_no_typedefs):
Return unique_xmalloc_ptr.
* cp-support.c (inspect_type): Update.
(cp_canonicalize_string_full): Return unique_xmalloc_ptr.
(cp_canonicalize_string_no_typedefs, cp_canonicalize_string):
Likewise.
* c-typeprint.c (print_name_maybe_canonical): Update.
* break-catch-throw.c (check_status_exception_catchpoint):
Update.
When running test-case gdb.threads/fork-child-threads.exp with gcc-8 instead
of gcc-7, we have:
...
(gdb) next^M
[Attaching after Thread 0x7ffff7fae740 (LWP 27574) fork to child process \
27578]^M
[New inferior 2 (process 27578)]^M
[Detaching after fork from parent process 27574]^M
[Inferior 1 (process 27574) detached]^M
[Thread debugging using libthread_db enabled]^M
Using host libthread_db library "/lib64/libthread_db.so.1".^M
[Switching to Thread 0x7ffff7fae740 (LWP 27578)]^M
-main () at src/gdb/testsuite/gdb.threads/fork-child-threads.c:41^M
+main () at src/gdb/testsuite/gdb.threads/fork-child-threads.c:34^M
-41 i = pthread_create (&thread, NULL, start, NULL);^M
+34 switch (fork ())^M
-(gdb) PASS: gdb.threads/fork-child-threads.exp: next over fork
+(gdb) FAIL: gdb.threads/fork-child-threads.exp: next over fork
...
This is due to the fact that gcc-8 generates more precise line info, making
the instruction after the call to fork a "recommended breakpoint location".
However, it is a bug because next is supposed to move to the next source
line.
The problem is that in process_event_stop_test we hit this code:
...
if ((ecs->event_thread->suspend.stop_pc == stop_pc_sal.pc)
&& (ecs->event_thread->current_line != stop_pc_sal.line
|| ecs->event_thread->current_symtab != stop_pc_sal.symtab))
{
if (stop_pc_sal.is_stmt)
{
/* We are at the start of a different line. So stop. Note that
we don't stop if we step into the middle of a different line.
That is said to make things like for (;;) statements work
better. */
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog,
"infrun: stepped to a different line\n");
end_stepping_range (ecs);
return;
}
...
because current_line and current_symtab have initial values:
...
(gdb) p ecs->event_thread->current_line
$8 = 0
(gdb) p ecs->event_thread->current_symtab
$9 = (symtab *) 0x0
...
Fix this in follow_fork by copying current_line and current_symtab from
parent thread to child thread.
Tested on x86_64-linux, with gcc 7.5.0 and gcc 10.0.1.
gdb/ChangeLog:
2020-05-08 Tom de Vries <tdevries@suse.de>
* infrun.c (follow_fork): Copy current_line and current_symtab to
child thread.
This is a small cleanup to normalize the structures in async-event.c
with the rest of the code base:
- Remove the unnecessary typedefs
- Fix indentation of struct bodies
- Put comments above fields
No functional changes expected.
gdb/ChangeLog:
* async-event.c (struct async_signal_handler, struct
async_event_handler): Reformat, remove typedef.
Remove this macro, which abstracts how to obtain the dyn_prop_list of a
given type. We could replace it with a method on `struct type`, but I
don't think it's needed, as the only code that accesses the dynamic prop
list directly is internal gdbtypes.c code (that can be seen as code
internal to `struct type`). So it can just refer to the field directly.
gdb/ChangeLog:
* gdbtypes.h (TYPE_DYN_PROP_LIST): Remove. Update all users
access thistype->main_type->dyn_prop_list directly.
Move remove_dyn_prop, currently a free function, to be a method of
struct type.
gdb/ChangeLog:
* gdbtypes.h (struct type) <remove_dyn_prop>: New method.
(remove_dyn_prop): Remove. Update all users to use
type::remove_dyn_prop.
* gdbtypes.c (remove_dyn_prop): Rename to...
(type::remove_dyn_prop): ... this.
Move add_dyn_prop, currently a free function, to be a method of struct
type.
gdb/ChangeLog:
* gdbtypes.h (struct type) <add_dyn_prop>: New method.
(add_dyn_prop): Remove. Update all users to use
type::add_dyn_prop.
* gdbtypes.c (add_dyn_prop): Rename to...
(type::add_dyn_prop): ... this.
Move get_dyn_prop, currently a free function, to be a method on struct
type.
gdb/ChangeLog:
* gdbtypes.h (struct type) <get_dyn_prop>: New method.
(get_dyn_prop): Remove. Update all users to use
type::dyn_prop.
* gdbtypes.c (get_dyn_prop): Rename to...
(type::dyn_prop): ... this.
v2:
- test: build full executable instead of object
- test: add and use supports_fcf_protection
- test: use gdb_test_multiple's -wrap option
- test: don't execute gdb_assert if failed to get breakpoint address
Some GCCs now enable -fcf-protection by default. This is the case, for
example, with GCC 9.3.0 on Ubuntu 20.04. Enabling it causes the
`endbr64` instruction to be inserted at the beginning of all functions
and that breaks GDB's prologue analysis.
I noticed this because it gives many failures in gdb.base/break.exp.
But let's take this dummy program and put a breakpoint on main:
int main(void)
{
return 0;
}
Without -fcf-protection, the breakpoint is correctly put after the prologue:
$ gcc test.c -g3 -O0 -fcf-protection=none
$ ./gdb -q -nx --data-directory=data-directory a.out
Reading symbols from a.out...
(gdb) disassemble main
Dump of assembler code for function main:
0x0000000000001129 <+0>: push %rbp
0x000000000000112a <+1>: mov %rsp,%rbp
0x000000000000112d <+4>: mov $0x0,%eax
0x0000000000001132 <+9>: pop %rbp
0x0000000000001133 <+10>: retq
End of assembler dump.
(gdb) b main
Breakpoint 1 at 0x112d: file test.c, line 3.
With -fcf-protection, the breakpoint is incorrectly put on the first
byte of the function:
$ gcc test.c -g3 -O0 -fcf-protection=full
$ ./gdb -q -nx --data-directory=data-directory a.out
Reading symbols from a.out...
(gdb) disassemble main
Dump of assembler code for function main:
0x0000000000001129 <+0>: endbr64
0x000000000000112d <+4>: push %rbp
0x000000000000112e <+5>: mov %rsp,%rbp
0x0000000000001131 <+8>: mov $0x0,%eax
0x0000000000001136 <+13>: pop %rbp
0x0000000000001137 <+14>: retq
End of assembler dump.
(gdb) b main
Breakpoint 1 at 0x1129: file test.c, line 2.
Stepping in amd64_skip_prologue, we can see that the prologue analysis,
for GCC-compiled programs, is done in amd64_analyze_prologue by decoding
the instructions and looking for typical patterns. This patch changes
the analysis to check for a prologue starting with the `endbr64`
instruction, and skip it if it's there.
gdb/ChangeLog:
* amd64-tdep.c (amd64_analyze_prologue): Check for `endbr64`
instruction, skip it if it's there.
gdb/testsuite/ChangeLog:
* gdb.arch/amd64-prologue-skip-cf-protection.exp: New file.
* gdb.arch/amd64-prologue-skip-cf-protection.c: New file.
It is unused. The corresponding macro was removed in c3236f84c1 ("gdb:
remove TYPE_INCOMPLETE").
gdb/ChangeLog:
* gdbtypes.h (struct main_type) <flag_incomplete>: Remove.
The "HP platforms" comment prompted me to check if this was still used
somewhere. Apparently it's not, so remove it.
gdb/ChangeLog:
* gdbtypes.h (TYPE_INCOMPLETE): Remove.
* gdbtypes.c (recursive_dump_type): Remove use of
TYPE_INCOMPLETE.
I looked at all the calls to add_prefix_cmd, and replaced them with
calls to add_basic_prefix_cmd or add_show_prefix_cmd when appropriate.
This makes gdb's command language a bit more regular. I don't think
there's a significant downside.
Note that this patch removes a couple of tests. The removed ones are
completely redundant.
gdb/ChangeLog
2020-05-03 Tom Tromey <tom@tromey.com>
* breakpoint.c (catch_command, tcatch_command): Remove.
(_initialize_breakpoint): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
(set_breakpoint_cmd, show_breakpoint_cmd): Remove
* utils.c (set_internal_problem_cmd, show_internal_problem_cmd):
Remove.
(add_internal_problem_command): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* mips-tdep.c (set_mipsfpu_command): Remove.
(_initialize_mips_tdep): Use add_basic_prefix_cmd.
* dwarf2/index-cache.c (set_index_cache_command): Remove.
(_initialize_index_cache): Use add_basic_prefix_cmd.
* memattr.c (dummy_cmd): Remove.
(_initialize_mem): Use add_basic_prefix_cmd, add_show_prefix_cmd.
* tui/tui-win.c (set_tui_cmd, show_tui_cmd): Remove.
(_initialize_tui_win): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
* cli/cli-logging.c (set_logging_command): Remove.
(_initialize_cli_logging): Use add_basic_prefix_cmd,
add_show_prefix_cmd.
(show_logging_command): Remove.
* target.c (target_command): Remove.
(add_target): Use add_basic_prefix_cmd.
gdb/testsuite/ChangeLog
2020-05-03 Tom Tromey <tom@tromey.com>
* gdb.base/sepdebug.exp: Remove "catch" test.
* gdb.base/break.exp: Remove "catch" test.
* gdb.base/default.exp: Update expected output.
The function info_command has disappeared, so this breakpoint does not
work anymore.
"info_command" was a function for the prefix command "info",
giving the list of "info" subcommands.
It is not very clear what the removed breakpoint and its associated
command list was supposed to do.
Removed and pushed as obvious, after discussion with Tom.
Report LWP CREATE and LWP EXIT events and setup this on post_attach()
and post_startup_inferior().
Stop reinitializing the list of recognized threads in update_thread_list().
Handle LWP CREATE and EXIT events in nbsd_nat_target::wait().
gdb/ChangeLog:
* nbsd-nat.c (nbsd_enable_proc_events)
(nbsd_nat_target::post_startup_inferior): Add.
(nbsd_nat_target::post_attach): Call `nbsd_enable_proc_events'.
(nbsd_nat_target::update_thread_list): Rewrite.
(nbsd_nat_target::wait): Handle "PTRACE_LWP_EXIT" and
"PTRACE_LWP_CREATE".
* nbsd-nat.h (nbsd_nat_target::post_startup_inferior): Add.
This reverts commit 84ed7a4725.
The problem that the commit attempts to address has already been fixed in
commit 770479f223 "gdb: Fix toplevel types with -fdebug-types-section".
The commit itself is superfluous because it sets list_in_scope at a point that
it's already set (by start_symtab).
"frame" and "f" are created twice by stack.c _initialize_stack.
Remove the second creation.
Regression tested on amd64/Debian.
2020-04-30 Philippe Waroquiers <philippe.waroquiers@skynet.be>
* stack.c (_initialize_stack): Remove duplicated creation
of "frame" command and "f" alias.
Sizes of stubbed types are calculated on demand in check_typedef, so the
same must also be done for arrays of stubbed types.
A stubbed type is usually a structure that has only been forward declared,
but can also happen if the structure has a virtual function that's not
inline in the class definition.
For these stubbed types, the size must be recalculated once the full
definition is available.
gdb/ChangeLog:
2020-04-30 Hannes Domani <ssbssa@yahoo.de>
PR gdb/18706
* gdbtypes.c (check_typedef): Calculate size of array of
stubbed type.
gdb/testsuite/ChangeLog:
2020-04-30 Hannes Domani <ssbssa@yahoo.de>
PR gdb/18706
* gdb.cp/stub-array-size.cc: New test.
* gdb.cp/stub-array-size.exp: New file.
* gdb.cp/stub-array-size.h: New test.
* gdb.cp/stub-array-size2.cc: New test.
Non-static member functions for Windows 32bit programs need the thiscall
calling convention, so the 'this' pointer needs to be passed in ECX.
gdb/ChangeLog:
2020-04-30 Hannes Domani <ssbssa@yahoo.de>
PR gdb/15559
* i386-tdep.c (i386_push_dummy_call): Call
i386_thiscall_push_dummy_call.
(i386_thiscall_push_dummy_call): New function.
* i386-tdep.h (i386_thiscall_push_dummy_call): Declare.
* i386-windows-tdep.c (i386_windows_push_dummy_call): New function.
(i386_windows_init_abi): Call set_gdbarch_push_dummy_call.
shellcheck reports:
In gdbarch.sh line 53:
while IFS='' read line
^--^ SC2162: read without -r will mangle backslashes.
See the rationale at [1]. In our case, we actually want the backslashes
to be interpreted and removed. Silence the warning using a directive.
[1] https://github.com/koalaman/shellcheck/wiki/SC2162
gdb/ChangeLog:
* gdbarch.sh (do_read): Add shellcheck disable directive for
warning SC2162.
Philippe Waroquiers
Joel Brobecker
Kevin Buettner
Laurent Morichetti
Simon Marchi
Tankut Baris Aktemur
Tom Tromey
Tom de Vries
Tom Tromey
Hannes Domani
Andrew Burgess
Kamil Rytarowski