As we move code on reading unavailable memory to target side, GDB core
side doesn't need the "switching momentarily out of tfind mode" dance.
The target remote knows how to read live memory (through remote_ops).
Remove set_traceframe_number and
make_cleanup_restore_traceframe_number, since they are no longer used.
gdb:
2014-03-22 Yao Qi <yao@codesourcery.com>
* remote.c (target_read_live_memory): Remove.
(memory_xfer_live_readonly_partial): Rename it to
remote_xfer_live_readonly_partial. Remove argument 'object'.
All callers updated. Call remote_read_bytes_1
instead of target_read_live_memory.
* tracepoint.c (set_traceframe_number): Remove.
(make_cleanup_restore_traceframe_number): Likewise .
* tracepoint.h (set_traceframe_number): Remove declaration.
(make_cleanup_restore_traceframe_number): Likewise.
This patch moves code in remote_read_bytes on reading from the remote
stub to a new function remote_read_bytes_1.
gdb:
2014-03-22 Yao Qi <yao@codesourcery.com>
* remote.c (remote_read_bytes): Move code on reading from the
remote stub to ...
(remote_read_bytes_1): ... here. New function.
As a follow-up to
[PATCH 7/8] Adjust read_value_memory to use to_xfer_partial
https://sourceware.org/ml/gdb-patches/2014-02/msg00384.html
this patch moves traceframe_available_memory down to the target side.
After this patch, the gdb core code is cleaner, and code on handling
unavailable memory is moved to remote/tfile/ctf targets.
In details, this patch moves traceframe_available_memory code from
memory_xfer_partial_1 to remote target only, so remote target still
uses traceframe_info mechanism to check unavailable memory, and use
remote_ops to read them from read-only sections. We don't use
traceframe_info mechanism for tfile and ctf target, because it is
fast to iterate all traceframes from trace file, so the summary
information got from traceframe_info is not necessary.
This patch also moves two functions to remote.c from target.c,
because they are only used in remote.c. I'll clean them up in another
patch.
gdb:
2014-03-22 Yao Qi <yao@codesourcery.com>
* ctf.c (ctf_xfer_partial): Check the return value of
exec_read_partial_read_only, if it is not TARGET_XFER_OK,
return TARGET_XFER_UNAVAILABLE.
* tracefile-tfile.c (tfile_xfer_partial): Likewise.
* target.c (target_read_live_memory): Move it to remote.c.
(memory_xfer_live_readonly_partial): Likewise.
(memory_xfer_partial_1): Move some code to remote_read_bytes.
* remote.c (target_read_live_memory): Moved from target.c.
(memory_xfer_live_readonly_partial): Likewise.
(remote_read_bytes): New, factored out from
memory_xfer_partial_1.
This fixes:
FAIL: gdb.threads/thread-specific.exp: continue to thread-specific breakpoint (timeout)
ERROR: tcl error sourcing .../gdb/testsuite/gdb.threads/thread-specific.exp.
ERROR: can't read "this_breakpoint": no such variable
while executing
"gdb_test_multiple "info breakpoint $this_breakpoint" "info on bp" {
-re ".*stop only in thread (\[0-9\]*).*$gdb_prompt $" {
set this_thread $expe..."
(file ".../gdb/testsuite/gdb.threads/thread-specific.exp" line 108)
invoked from within
"source .../gdb/testsuite/gdb.threads/thread-specific.exp"
("uplevel" body line 1)
invoked from within
"uplevel #0 source .../gdb/testsuite/gdb.threads/thread-specific.exp"
invoked from within
"catch "uplevel #0 source $test_file_name""
and then:
FAIL: gdb.threads/thread-specific.exp: continue to thread-specific breakpoint (timeout)
UNTESTED: gdb.threads/thread-specific.exp: info on bp
ERROR: tcl error sourcing .../gdb/testsuite/gdb.threads/thread-specific.exp.
ERROR: can't read "this_thread": no such variable
while executing
"gdb_test {print $_thread} ".* = $this_thread" "thread var at break""
(file ".../gdb/testsuite/gdb.threads/thread-specific.exp" line 119)
invoked from within
"source .../gdb/testsuite/gdb.threads/thread-specific.exp"
("uplevel" body line 1)
invoked from within
"uplevel #0 source .../gdb/testsuite/gdb.threads/thread-specific.exp"
invoked from within
"catch "uplevel #0 source $test_file_name""
Final results:
FAIL: gdb.threads/thread-specific.exp: continue to thread-specific breakpoint (timeout)
UNTESTED: gdb.threads/thread-specific.exp: info on bp
UNTESTED: gdb.threads/thread-specific.exp: thread var at break
Of course the first failure best wasn't there, but failing that the script
shouldn't crash.
* gdb.threads/thread-specific.exp: Handle the lack of usable
$this_breakpoint and $this_thread.
ps -e | grep a.out
28886 pts/12 00:00:00 a.out
gdb -p 28886
Loaded symbols for /lib64/ld-linux-x86-64.so.2
0x0000003b0ccbc970 in __nanosleep_nocancel () from /lib64/libc.so.6
../../binutils-gdb/gdb/cleanups.c:265: internal-warning: restore_my_cleanups has found a stale cleanup
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)
The backtrace of this issue:
(gdb) bt
file=0x8b0c10 "s' failed.", line=265, fmt=0x8b0c38 "nutils-gdb/gdb/cleanups.c",
ap=0x7fff803e3ed8) at ../../binutils-gdb/gdb/utils.c:748
fmt=0x8b0c38 "nutils-gdb/gdb/cleanups.c", ap=0x7fff803e3ed8)
at ../../binutils-gdb/gdb/utils.c:799
string=0x8b0c38 "nutils-gdb/gdb/cleanups.c") at ../../binutils-gdb/gdb/utils.c:809
at ../../binutils-gdb/gdb/cleanups.c:265
at ../../binutils-gdb/gdb/cleanups.c:276
at ../../binutils-gdb/gdb/exceptions.c:142
at ../../binutils-gdb/gdb/exceptions.c:203
command=0x5d5fb8 <attach_command_continuation_free_args+18>, arg=0x7fff803e525b "2914",
from_tty=1, mask=RETURN_MASK_ALL) at ../../binutils-gdb/gdb/exceptions.c:549
---Type <return> to continue, or q <return> to quit---
func_args=0x7fff803e4280, errstring=0x8cf2e4 "/local/bin", mask=RETURN_MASK_ALL)
at ../../binutils-gdb/gdb/exceptions.c:522
This is a new issue. It is introduced by commit https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=8bc2fe488957946d2cdccda3ce8d4f39e4003ea0
It removed the discard_cleanups (back_to) inside attach_command.
Then restore_my_cleanups will throw a internal_warning.
https://sourceware.org/ml/gdb-patches/2014-03/msg00374.html
2014-03-21 Hui Zhu <hui@codesourcery.com>
Pedro Alves <palves@redhat.com>
* darwin-nat.c (darwin_pid_to_exec_file): Change xmalloc to
static buffer.
* fbsd-nat.c (fbsd_pid_to_exec_file): Ditto.
* linux-nat.c (linux_child_pid_to_exec_file): Ditto.
* nbsd-nat.c (nbsd_pid_to_exec_file): Ditto.
This patch adds initial in-gas opcode relaxation for the rl78
backend. Specifically, it checks for conditional branches that
are too far and replaces them with inverted branches around longer
fixed branches.
-- Initial message by Tom Tromey:
While testing on AIX, I happened to notice an internal error coming
from parse_probes. This happens because there are no probes defined
on this platform. This patch fixes the problem by changing an assert
into an ordinary error, and then changing the relevant caller to cope.
This fixes a few tests on AIX; also regtested on x86-64 Fedora 18.
-- Followup by Sergio Durigan Junior:
By reading the patch (and the original code), I found it a little bit
obscure, so I took the liberty to try to improve it. Here's the patch.
Could you please take a look and see if it works on AIX (and also if you
like the approach)?
gdb/
2014-03-20 Tom Tromey <tromey@redhat.com>
Sergio Durigan Junior <sergiodj@redhat.com>
* probe.c (parse_probes): Turn assert into an ordinary error.
* break-catch-throw.c (re_set_exception_catchpoint): Ignore
exceptions when parsing probes. Rearrange the code for clarity.
With target async enabled, py-finish-breakpoint.exp triggers an
assertion failure.
The failure occurs because execute_command re-enters the event loop in
some circumstances, and in this case resets the sync_execution flag.
Then later GDB reaches this assertion in normal_stop:
gdb_assert (sync_execution || !target_can_async_p ());
In detail:
#1 - A synchronous execution command is run. sync_execution is set.
#2 - A python breakpoint is hit (TARGET_WAITKIND_STOPPED), and the
corresponding Python breakpoint's stop method is executed. When
and while python commands are executed, interpreter_async is
forced to 0.
#3 - The Python stop method happens to execute a not-execution-related
gdb command. In this case, "where 1".
#4 - Seeing that sync_execution is set, execute_command nests a new
event loop (although that wasn't necessary; this is the problem).
#5 - The linux-nat target's pipe in the event loop happens to be
marked. That's normal, due to this in linux_nat_wait:
/* If we requested any event, and something came out, assume there
may be more. If we requested a specific lwp or process, also
assume there may be more. */
The nested event loop thus immediately wakes up and calls
target_wait. No thread is actually executing in the inferior, so
the target returns TARGET_WAITKIND_NO_RESUMED.
#6 - normal_stop is reached. GDB prints "No unwaited-for children
left.", and resets the sync_execution flag (IOW, there are no
resumed threads left, so the synchronous command is considered
completed.) This is already bogus. We were handling a
breakpoint!
#7 - the nested event loop unwinds/ends. GDB is now back to handling
the python stop method (TARGET_WAITKIND_STOPPED), which decides
the breakpoint should stop. normal_stop is called for this
event. However, normal_stop actually works with the _last_
reported target status:
void
normal_stop (void)
{
struct target_waitstatus last;
ptid_t last_ptid;
struct cleanup *old_chain = make_cleanup (null_cleanup, NULL);
...
get_last_target_status (&last_ptid, &last);
...
if (last.kind == TARGET_WAITKIND_NO_RESUMED)
{
gdb_assert (sync_execution || !target_can_async_p ());
target_terminal_ours_for_output ();
printf_filtered (_("No unwaited-for children left.\n"));
}
And due to the nesting in execute command, the last event is now
TARGET_WAITKIND_NO_RESUMED, not the actual breakpoint event being
handled. This could be seen to be broken in itself, but we can
leave fixing that for another pass. The assertion is reached, and
fails.
execute_command has a comment explaining when it should synchronously
wait for events:
/* If the interpreter is in sync mode (we're running a user
command's list, running command hooks or similars), and we
just ran a synchronous command that started the target, wait
for that command to end. */
However, the code did not follow this comment -- it didn't check to
see if the command actually started the target, just whether the
target was executing a sync command at this point.
This patch fixes the problem by noting whether the target was
executing in sync_execution mode before running the command, and then
augmenting the condition to test this as well.
2014-03-20 Tom Tromey <tromey@redhat.com>
PR gdb/14135
* top.c (execute_command): Only dispatch events if the command
started the target.
When target-async is enabled, dprintf.exp fails:
Running ../../../src/gdb/testsuite/gdb.base/dprintf.exp ...
FAIL: gdb.base/dprintf.exp: 1st dprintf, call
FAIL: gdb.base/dprintf.exp: 2nd dprintf, call
FAIL: gdb.base/dprintf.exp: Set dprintf function
FAIL: gdb.base/dprintf.exp: 1st dprintf, fprintf
FAIL: gdb.base/dprintf.exp: 2nd dprintf, fprintf
Breakpoint 2, main (argc=1, argv=0x7fffffffd3f8) at ../../../src/gdb/testsuite/gdb.base/dprintf.c:33
33 int loc = 1234;
(gdb) continue
Continuing.
kickoff 1234
also to stderr 1234
At foo entry
(gdb) FAIL: gdb.base/dprintf.exp: 1st dprintf, call
The problem is that GDB gave the prompt back to the user too early.
This happens when calling functions while handling an event that
doesn't cause a user visible stop. dprintf with "set dprintf-style
gdb" is one such case. This patch adds a test case that has a
breakpoint with a condition that calls a function that returns false,
so that regression testing isn't dependent on the implementation of
dprintf.
The problem happens because run_inferior_call causes GDB to forget
that it is running in sync_execution mode, so any event that runs an
inferior call causes fetch_inferior_event to display the prompt, even
if the event should not result in a user visible stop (that is, gdb
resumes the inferior and waits for the next event).
This patch fixes the issue by noticing when GDB was in sync_execution
mode in run_inferior_call, and taking care to restore this state
afterward.
gdb/
2014-03-20 Tom Tromey <tromey@redhat.com>
PR cli/15718
* infcall.c: Include event-top.h.
(run_inferior_call): Call async_disable_stdin if needed.
gdb/testsuite/
2014-03-20 Tom Tromey <tromey@redhat.com>
Pedro Alves <palves@redhat.com>
PR cli/15718
* gdb.base/condbreak-call-false.c: New file.
* gdb.base/condbreak-call-false.exp: New file.
For gathers with indices larger than elements (e. g.)
vpgatherqd ymm6{k1}, ZMMWORD PTR [ebp+zmm7*8-123]
We currently treat memory size as a size of index register, while it is
actually should be size of destination register:
vpgatherqd ymm6{k1}, YMMWORD PTR [ebp+zmm7*8-123]
This patch fixes it.
opcodes/
* i386-opc.tbl: Change memory size for vgatherpf0qps, vgatherpf1qps,
vscatterpf0qps, vscatterpf1qps, vgatherqps, vpgatherqd, vpscatterqd,
vscatterqps.
* i386-tbl.h: Regenerate.
gas/testsuite/
* gas/i386/avx512pf-intel.d: Change memory size for vgatherpf0qps,
vgatherpf1qps, vscatterpf0qps, vscatterpf1qps.
* gas/i386/avx512pf.s: Ditto.
* gas/i386/x86-64-avx512pf-intel.d: Ditto.
* gas/i386/x86-64-avx512pf.s: Ditto.
* gas/i386/avx512f-intel.d: Change memory size for vgatherqps,
vpgatherqd, vpscatterqd, vscatterqps.
* gas/i386/avx512f.s: Ditto.
* gas/i386/x86-64-avx512f-intel.d: Ditto.
* gas/i386/x86-64-avx512f.s: Ditto.
This test now uses pthread_kill instead of the host's kill command, so
no longer need to block signals, or store the the inferior's PID.
gdb/testsuite/
2014-03-20 Pedro Alves <palves@redhat.com>
* gdb.threads/signal-while-stepping-over-bp-other-thread.c (pid):
Delete.
(block_signals, unblock_signals): Delete.
(child_function_2, main): Remove references to deleted variable
and functions.
Use pthread_kill instead of the host's "kill". The reason the test
wasn't written that way to begin with, is that done this way, before
the previous fixes to make GDB step-over all other threads before the
stepping thread, the test would fail...
Tested on x86_64 Fedora 17, native and gdbserver.
gdb/testsuite/
2014-03-20 Pedro Alves <palves@redhat.com>
* gdb.threads/signal-while-stepping-over-bp-other-thread.c (main):
Use pthread_kill to signal thread 2.
* gdb.threads/signal-while-stepping-over-bp-other-thread.exp:
Adjust to make the test send itself a signal rather than using the
host's "kill" command.
This test fails with current mainline.
If the program stopped for a breakpoint in thread 1, and then the user
switches to thread 2, and resumes the program, GDB first switches back
to thread 1 to step it over the breakpoint, in order to make progress.
However, that logic only considers the last reported event, assuming
only one thread needs that stepping over dance.
That's actually not true when we play with scheduler-locking. The
patch adds an example to the testsuite of multiple threads needing a
step-over before the stepping thread can be resumed. With current
mainline, the program re-traps the same breakpoint it had already
trapped before.
E.g.:
Breakpoint 2, main () at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:99
99 wait_threads (); /* set wait-threads breakpoint here */
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: continue to breakpoint: run to breakpoint
info threads
Id Target Id Frame
3 Thread 0x7ffff77c9700 (LWP 4310) "multiple-step-o" 0x00000000004007ca in child_function_3 (arg=0x1) at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:43
2 Thread 0x7ffff7fca700 (LWP 4309) "multiple-step-o" 0x0000000000400827 in child_function_2 (arg=0x0) at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:60
* 1 Thread 0x7ffff7fcb740 (LWP 4305) "multiple-step-o" main () at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:99
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: info threads shows all threads
set scheduler-locking on
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: set scheduler-locking on
break 44
Breakpoint 3 at 0x4007d3: file ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c, line 44.
(gdb) break 61
Breakpoint 4 at 0x40082d: file ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c, line 61.
(gdb) thread 3
[Switching to thread 3 (Thread 0x7ffff77c9700 (LWP 4310))]
#0 0x00000000004007ca in child_function_3 (arg=0x1) at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:43
43 (*myp) ++;
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: thread 3
continue
Continuing.
Breakpoint 3, child_function_3 (arg=0x1) at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:44
44 callme (); /* set breakpoint thread 3 here */
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: continue to breakpoint: run to breakpoint in thread 3
p *myp = 0
$1 = 0
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: unbreak loop in thread 3
thread 2
[Switching to thread 2 (Thread 0x7ffff7fca700 (LWP 4309))]
#0 0x0000000000400827 in child_function_2 (arg=0x0) at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:60
60 (*myp) ++;
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: thread 2
continue
Continuing.
Breakpoint 4, child_function_2 (arg=0x0) at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:61
61 callme (); /* set breakpoint thread 2 here */
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: continue to breakpoint: run to breakpoint in thread 2
p *myp = 0
$2 = 0
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: unbreak loop in thread 2
thread 1
[Switching to thread 1 (Thread 0x7ffff7fcb740 (LWP 4305))]
#0 main () at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:99
99 wait_threads (); /* set wait-threads breakpoint here */
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: thread 1
set scheduler-locking off
(gdb) PASS: gdb.threads/multiple-step-overs.exp: step: set scheduler-locking off
At this point all thread are stopped for a breakpoint that needs stepping over.
(gdb) step
Breakpoint 2, main () at ../../../src/gdb/testsuite/gdb.threads/multiple-step-overs.c:99
99 wait_threads (); /* set wait-threads breakpoint here */
(gdb) FAIL: gdb.threads/multiple-step-overs.exp: step
But that "step" retriggers the same breakpoint instead of making
progress.
The patch teaches GDB to step over all breakpoints of all threads
before resuming the stepping thread.
Tested on x86_64 Fedora 17, against pristine mainline, and also my
branch that implements software single-stepping on x86.
gdb/
2014-03-20 Pedro Alves <palves@redhat.com>
* infrun.c (prepare_to_proceed): Delete.
(thread_still_needs_step_over): New function.
(find_thread_needs_step_over): New function.
(proceed): If the current thread needs a step-over, set its
steping_over_breakpoint flag. Adjust to use
find_thread_needs_step_over instead of prepare_to_proceed.
(process_event_stop_test): For BPSTAT_WHAT_STOP_NOISY and
BPSTAT_WHAT_STOP_SILENT, assume the thread stopped for a
breakpoint.
(switch_back_to_stepped_thread): Step over breakpoints of all
threads not the stepping thread, before switching back to the
stepping thread.
gdb/testsuite/
2014-03-20 Pedro Alves <palves@redhat.com>
* gdb.threads/multiple-step-overs.c: New file.
* gdb.threads/multiple-step-overs.exp: New file.
* gdb.threads/signal-while-stepping-over-bp-other-thread.exp:
Adjust expected infrun debug output.
Even with deferred_step_ptid out of the way, GDB can still lose
watchpoints.
If a watchpoint triggers and the PC points to an address where a
thread-specific breakpoint for another thread is set, the thread-hop
code triggers, and we lose the watchpoint:
if (ecs->event_thread->suspend.stop_signal == GDB_SIGNAL_TRAP)
{
int thread_hop_needed = 0;
struct address_space *aspace =
get_regcache_aspace (get_thread_regcache (ecs->ptid));
/* Check if a regular breakpoint has been hit before checking
for a potential single step breakpoint. Otherwise, GDB will
not see this breakpoint hit when stepping onto breakpoints. */
if (regular_breakpoint_inserted_here_p (aspace, stop_pc))
{
if (!breakpoint_thread_match (aspace, stop_pc, ecs->ptid))
thread_hop_needed = 1;
^^^^^^^^^^^^^^^^^^^^^
}
And on software single-step targets, even without a thread-specific
breakpoint in the way, here in the thread-hop code:
else if (singlestep_breakpoints_inserted_p)
{
...
if (!ptid_equal (singlestep_ptid, ecs->ptid)
&& in_thread_list (singlestep_ptid))
{
/* If the PC of the thread we were trying to single-step
has changed, discard this event (which we were going
to ignore anyway), and pretend we saw that thread
trap. This prevents us continuously moving the
single-step breakpoint forward, one instruction at a
time. If the PC has changed, then the thread we were
trying to single-step has trapped or been signalled,
but the event has not been reported to GDB yet.
There might be some cases where this loses signal
information, if a signal has arrived at exactly the
same time that the PC changed, but this is the best
we can do with the information available. Perhaps we
should arrange to report all events for all threads
when they stop, or to re-poll the remote looking for
this particular thread (i.e. temporarily enable
schedlock). */
CORE_ADDR new_singlestep_pc
= regcache_read_pc (get_thread_regcache (singlestep_ptid));
if (new_singlestep_pc != singlestep_pc)
{
enum gdb_signal stop_signal;
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog, "infrun: unexpected thread,"
" but expected thread advanced also\n");
/* The current context still belongs to
singlestep_ptid. Don't swap here, since that's
the context we want to use. Just fudge our
state and continue. */
stop_signal = ecs->event_thread->suspend.stop_signal;
ecs->event_thread->suspend.stop_signal = GDB_SIGNAL_0;
ecs->ptid = singlestep_ptid;
ecs->event_thread = find_thread_ptid (ecs->ptid);
ecs->event_thread->suspend.stop_signal = stop_signal;
stop_pc = new_singlestep_pc;
}
else
{
if (debug_infrun)
fprintf_unfiltered (gdb_stdlog,
"infrun: unexpected thread\n");
thread_hop_needed = 1;
stepping_past_singlestep_breakpoint = 1;
saved_singlestep_ptid = singlestep_ptid;
}
}
}
we either end up with thread_hop_needed, ignoring the watchpoint
SIGTRAP, or switch to the stepping thread, again ignoring that the
SIGTRAP could be for some other event.
The new test added by this patch exercises both paths.
So the fix is similar to the deferred_step_ptid fix -- defer the
thread hop to _after_ the SIGTRAP had a change of passing through the
regular bpstat handling. If the wrong thread hits a breakpoint, we'll
just end up with BPSTAT_WHAT_SINGLE, and if nothing causes a stop,
keep_going starts a step-over.
Most of the stepping_past_singlestep_breakpoint mechanism is really
not necessary -- setting the thread to step over a breakpoint with
thread->trap_expected is sufficient to keep all other threads locked.
It's best to still keep the flag in some form though, because when we
get to keep_going, the software single-step breakpoint we need to step
over is already gone -- an optimization done by a follow up patch will
check whether a step-over is still be necessary by looking to see
whether the breakpoint is still there, and would find the thread no
longer needs a step-over, while we still want it.
Special care is still needed to handle the case of PC of the thread we
were trying to single-step having changed, like in the old code. We
can't just keep_going and re-step it, as in that case we can over-step
the thread (if it was already done with the step, but hasn't reported
it yet, we'd ask it to step even further). That's now handled in
switch_back_to_stepped_thread. As bonus, we're now using a technique
that doesn't lose signals, unlike the old code -- we now insert a
breakpoint at PC, and resume, which either reports the breakpoint
immediately, or any pending signal.
Tested on x86_64 Fedora 17, against pristine mainline, and against a
branch that implements software single-step on x86.
gdb/
2014-03-20 Pedro Alves <palves@redhat.com>
* breakpoint.c (single_step_breakpoint_inserted_here_p): Make
extern.
* breakpoint.h (single_step_breakpoint_inserted_here_p): Declare.
* infrun.c (saved_singlestep_ptid)
(stepping_past_singlestep_breakpoint): Delete.
(resume): Remove stepping_past_singlestep_breakpoint handling.
(proceed): Store the prev_pc of the stepping thread too.
(init_wait_for_inferior): Adjust. Clear singlestep_ptid and
singlestep_pc.
(enum infwait_states): Delete infwait_thread_hop_state.
(struct execution_control_state) <hit_singlestep_breakpoint>: New
field.
(handle_inferior_event): Adjust.
(handle_signal_stop): Delete stepping_past_singlestep_breakpoint
handling and the thread-hop code. Before removing single-step
breakpoints, check whether the thread hit a single-step breakpoint
of another thread. If it did, the trap is not a random signal.
(switch_back_to_stepped_thread): If the event thread hit a
single-step breakpoint, unblock it before switching to the
stepping thread. Handle the case of the stepped thread having
advanced already.
(keep_going): Handle the case of the current thread moving past a
single-step breakpoint.
gdb/testsuite/
2014-03-20 Pedro Alves <palves@redhat.com>
* gdb.threads/step-over-trips-on-watchpoint.c: New file.
* gdb.threads/step-over-trips-on-watchpoint.exp: New file.
Say the program is stopped at a breakpoint, and the user sets a
watchpoint. When the program is next resumed, GDB will first step
over the breakpoint, as explained in the manual:
@value {GDBN} normally ignores breakpoints when it resumes
execution, until at least one instruction has been executed. If it
it did not do this, you would be unable to proceed past a breakpoint
without first disabling the breakpoint. This rule applies whether
or not the breakpoint already existed when your program stopped.
However, GDB currently also removes watchpoints, catchpoints, etc.,
and that means that the first instruction off the breakpoint does not
trigger the watchpoint, catchpoint, etc.
testsuite/gdb.base/watchpoint.exp has a kfail for this.
The PR proposes installing watchpoints only when stepping over a
breakpoint, but that misses catchpoints, etc.
A better fix would instead work from the opposite direction -- remove
only real breakpoints, leaving all other kinds of breakpoints
inserted.
But, going further, it's really a waste to constantly remove/insert
all breakpoints when stepping over a single breakpoint (generating a
pair of RSP z/Z packets for each breakpoint), so the fix goes a step
further and makes GDB remove _only_ the breakpoint being stepped over,
leaving all others installed. This then has the added benefit of
reducing breakpoint-related RSP traffic substancialy when there are
many breakpoints set.
gdb/
2014-03-20 Pedro Alves <palves@redhat.com>
PR breakpoints/7143
* breakpoint.c (should_be_inserted): Don't insert breakpoints that
are being stepped over.
(breakpoint_address_match): Make extern.
* breakpoint.h (breakpoint_address_match): New declaration.
* inferior.h (stepping_past_instruction_at): New declaration.
* infrun.c (struct step_over_info): New type.
(step_over_info): New global.
(set_step_over_info, clear_step_over_info)
(stepping_past_instruction_at): New functions.
(handle_inferior_event): Clear the step-over info when
trap_expected is cleared.
(resume): Remove now stale comment.
(clear_proceed_status): Clear step-over info.
(proceed): Adjust step-over handling to set or clear the step-over
info instead of removing all breakpoints.
(handle_signal_stop): When setting up a thread-hop, don't remove
breakpoints here.
(stop_stepping): Clear step-over info.
(keep_going): Adjust step-over handling to set or clear step-over
info and then always inserting breakpoints, instead of removing
all breakpoints when stepping over one.
gdb/testsuite/
2014-03-20 Pedro Alves <palves@redhat.com>
PR breakpoints/7143
* gdb.base/watchpoint.exp: Mention bugzilla bug number instead of
old gnats gdb/38. Remove kfail. Adjust to use gdb_test instead
of gdb_test_multiple.
* gdb.cp/annota2.exp: Remove kfail for gdb/38.
* gdb.cp/annota3.exp: Remove kfail for gdb/38.
Consider the case of the user doing "step" in thread 2, while thread 1
had previously stopped for a breakpoint. In order to make progress,
GDB makes thread 1 step over its breakpoint first (with all other
threads stopped), and once that is over, thread 2 then starts stepping
(with thread 1 and all others running free, by default). If GDB
didn't do that, thread 1 would just trip on the same breakpoint
immediately again. This is what the prepare_to_proceed /
deferred_step_ptid code is all about.
However, deferred_step_ptid code resumes the target with:
resume (1, GDB_SIGNAL_0);
prepare_to_wait (ecs);
return;
Recall we were just stepping over a breakpoint when we get here. That
means that _nothing_ had installed breakpoints yet! If there's
another breakpoint just after the breakpoint that was just stepped,
we'll miss it. The fix for that would be to use keep_going instead.
However, there are more problems. What if the instruction that was
just single-stepped triggers a watchpoint? Currently, GDB just
happily resumes the thread, losing that too...
Missed watchpoints will need yet further fixes, but we should keep
those in mind.
So the fix must be to let the trap fall through the regular bpstat
handling, and only if no breakpoint, watchpoint, etc. claims the trap,
shall we switch back to the stepped thread.
Now, nowadays, we have code at the tail end of trap handling that does
exactly that -- switch back to the stepped thread
(switch_back_to_the_stepped_thread).
So the deferred_step_ptid code is just standing in the way, and can
simply be eliminated, fixing bugs in the process. Sweet.
The comment about spurious "Switching to ..." made me pause, but is
actually stale nowadays. That isn't needed anymore.
previous_inferior_ptid used to be re-set at each (internal) event, but
now it's only touched in proceed and normal stop.
The two tests added by this patch fail without the fix.
Tested on x86_64 Fedora 17 (also against my software single-stepping
on x86 branch).
gdb/
2014-03-20 Pedro Alves <palves@redhat.com>
* infrun.c (previous_inferior_ptid): Adjust comment.
(deferred_step_ptid): Delete.
(infrun_thread_ptid_changed, prepare_to_proceed)
(init_wait_for_inferior): Adjust.
(handle_signal_stop): Delete deferred_step_ptid handling.
gdb/testsuite/
2014-03-20 Pedro Alves <palves@redhat.com>
* gdb.threads/step-over-lands-on-breakpoint.c: New file.
* gdb.threads/step-over-lands-on-breakpoint.exp: New file.
linker testsuite failures were showing up for the cris target. Fixed by
this patch.
* readelf.c (process_version_sections): Fix off-by-one error in
previous delta.
Unless pointer_equality_needed is set then set st_value to be zero
for undefined symbols.
bfd/ChangeLog:
2014-03-20 Will Newton <will.newton@linaro.org>
PR ld/16715
* elf32-arm.c (elf32_arm_check_relocs): Set
pointer_equality_needed for absolute references within
executable links.
(elf32_arm_finish_dynamic_symbol): Set st_value to zero
unless pointer_equality_needed is set.
ld/testsuite/ChangeLog:
2014-03-20 Will Newton <will.newton@linaro.org>
* ld-arm/ifunc-14.rd: Update symbol values.
send readelf into an infinite loop.
* readelf.c (process_version_sections): Prevent an infinite loop
when the vn_next field is zero but there are still entries to be
processed.
and %hstick_enable to the Sparc assembler.
* config/tc-sparc.c (hpriv_reg_table): Added entries for
%hstick_offset and %hstick_enable.
* doc/c-sparc.texi (Sparc-Regs): Document the %hstick_offset and
%hstick_enable hyperprivileged registers.
* sparc-dis.c (v9_hpriv_reg_names): Names for %hstick_offset and
%hstick_enable added.
* gas/sparc/rdhpr.s: Test rd %hstick_offset and %hstick_enable.
* gas/sparc/rdhpr.d: Likewise.
* gas/sparc/wrhpr.s: Test wr %hstick_offset and %hstick_enable.
* gas/sparc/wrhpr.d: Likewise.
There's no reason not to enable this test anymore.
Even if the current output isn't ideal (we mess up the prompt), it's what
we have today. We can adjust the test if the output improves.
gdb/testsuite/
2014-03-19 Pedro Alves <palves@redhat.com>
* gdb.base/async.exp: Remove early return.
This test is currently racy:
PASS: gdb.base/async.exp: step&
stepi&
(gdb) 0x0000000000400547 14 x = 5; x = 5;
completed.
PASS: gdb.base/async.exp: stepi&
nexti&
(gdb) 15 y = 3;
completed.FAIL: gdb.base/async.exp: nexti&
The problem is here:
-re "^$command\r\n${before_prompt}${gdb_prompt}${after_prompt}completed\.\r\n" {
pass "$command"
}
-re "$gdb_prompt.*completed\.$" {
fail "$command"
}
Note how the fail pattern is a subset of the pass pattern. If the
expect buffer happens to end up with:
"^$command\r\n${before_prompt}${gdb_prompt}${after_prompt}completed\."
that is, the final "\r\n" has't reached the expect buffer yet, but
"completed." has, then the fail pattern matches...
gdb/testsuite/
2014-03-19 Pedro Alves <palves@redhat.com>
* gdb.base/async.exp (test_background): Expect \r\n after
"completed." in the fail pattern.
All the tests here follow the same pattern (and they all have the same
problem, not fixed here yet). Add a new procedure, factoring out the
pattern to a simple place.
gdb/testsuite/
2014-03-19 Pedro Alves <palves@redhat.com>
* gdb.base/async.exp (test_background): New procedure.
Use it for all background execution command tests.
Currently the test assumes that "stepi" over:
13 x = 5;
end up somewhere midline. But, (at least) on x86, that assignment
ends up compiled as just one movl instruction, so a stepi stops at the
next line already:
completed.
PASS: gdb.base/async.exp: step &
step&
(gdb) foo () at ../../../src/gdb/testsuite/gdb.base/async.c:13
13 x = 5;
completed.
PASS: gdb.base/async.exp: step &
stepi&
(gdb) 14 y = 3;
completed.
FAIL: gdb.base/async.exp: (timeout) stepi &
nexti&
(gdb) 16 return x + y;
completed.
FAIL: gdb.base/async.exp: (timeout) nexti &
finish&
Run till exit from #0 foo () at ../../../src/gdb/testsuite/gdb.base/async.c:16
This patch fixes it, by making sure there's more than one instruction
in that line.
gdb/testsuite/
2014-03-19 Pedro Alves <palves@redhat.com>
* gdb.base/async.c (foo): Make 'x' volatile. Write to it twice in
the same line.
gdb/testsuite/
2014-03-19 Pedro Alves <palves@redhat.com>
* gdb.base/async.c (main): Add "jump here" and "until here" line
marker comments.
* gdb.base/async.exp (jump_here): New global.
(jump& test): Use it.
(until_here): New global.
(until& test): Use it.
Many eons ago, async was only implemented in the remote target, and
you'd activate it by doing "target async" rather than "target remote".
That's long gone now, replaced by "set target-async on".
gdb/testsuite/
2014-03-19 Pedro Alves <palves@redhat.com>
* gdb.base/async.exp: Don't frob gdb_protocol.
should work for all types of input .rsrc section.
* peXXigen.c (rsrc_process_section): Add code to scan input
sections and record their lengths. Use these lengths to find the
start of each merged .rsrc section.
* scripttempl/pe.sc (R_RSRC): Fix default-manifest exclusion.
(.rsrc): Add SUBALIGN(4). Remove SORT.
* scripttempl/pep.sc: Likewise.
* config/tc-arm.c (codecomposer_syntax): New flag that states whether the
CCS syntax compatibility mode is on or off.
(asmfunc_states): New enum to represent the asmfunc directive state.
(asmfunc_state): New variable holding the asmfunc directive state.
(comment_chars): Rename to arm_comment_chars.
(line_separator_chars): Rename to arm_line_separator_chars.
(s_ccs_ref): New function that handles the .ref directive.
(asmfunc_debug): New function.
(s_ccs_asmfunc): New function that handles the .asmfunc directive.
(s_ccs_endasmfunc): New function that handles the .endasmfunc directive.
(s_ccs_def): New function that handles the .def directive.
(tc_start_label_without_colon): New function.
(md_pseudo_table): Added new CCS directives.
(arm_ccs_mode): New function that handles the -mccs command line option.
(arm_long_opts): Added new -mccs command line option.
* config/tc-arm.h (LABELS_WITHOUT_COLONS): New macro.
(TC_START_LABEL_WITHOUT_COLON): New macro.
(tc_start_label_without_colon): Added extern function declaration.
(tc_comment_chars): Define.
(tc_line_separator_chars): Define.
* app.c (do_scrub_begin): Use tc_line_separator_chars, if defined.
* read.c (read_begin): Likewise.
* doc/as.texinfo: Add documentation for the -mccs command line
option.
* doc/c-arm.texi: Likewise.
* doc/internals.texi: Document tc_line_separator_chars.
* NEWS: Mention the new feature.
* gas/arm/ccs.s: New test case.
* gas/arm/ccs.d: New expected disassembly.
* rx-decode.opc (bwl): Allow for bogus instructions with a size
field of 3.
(sbwl, ubwl, SCALE): Likewise.
* rx-decode.c: Regenerate.
* gas/rx/mov.d: Update expected disassembly.
