tracepoint->step_count fixes

If a tracepoint's actions list includes a while-stepping action, and
then the actions are changed to a list without any while-stepping
action, the tracepoint's step_count will be left with a stale value.
For example:

 (gdb) trace subr
 Tracepoint 1 at 0x4004d9: file ../../../src/gdb/testsuite//actions-changed.c, line 31.
 (gdb) actions
 Enter actions for tracepoint 1, one per line.
 End with a line saying just "end".
 >collect $reg
 >end
 (gdb) set debug remote 1
 (gdb) tstart
 Sending packet: $QTinit#59...Packet received: OK
 Sending packet: $QTDP:1:00000000004004d9:E:0:0-#a3...Packet received: OK
 Sending packet: $QTDP👎00000000004004d9:R03FFFFFFFFFFFFFFFFFF#2b...Packet received: OK
 (gdb) tstop
 Sending packet: $QTStop#4b...Packet received: OK
 Sending packet: $QTNotes:#e8...Packet received: OK
 (gdb) actions
 Enter actions for tracepoint 1, one per line.
 End with a line saying just "end".
 >collect $reg
 >while-stepping 1
   >collect $reg
   >end
 >end
 (gdb) tstart
 Sending packet: $QTinit#59...Packet received: OK
 Sending packet: $QTDP:1:00000000004004d9:E:1:0-#a4...Packet received: OK
 Sending packet: $QTDP👎00000000004004d9:R03FFFFFFFFFFFFFFFFFF-#58...Packet received: OK
 Sending packet: $QTDP👎00000000004004d9:SR03FFFFFFFFFFFFFFFFFF#7e...Packet received: OK
 (gdb) tstop
 Sending packet: $QTStop#4b...Packet received: OK
 Sending packet: $QTNotes:#e8...Packet received: OK
 (gdb) actions
 Enter actions for tracepoint 1, one per line.
 End with a line saying just "end".
 >collect $regs
 >end
 (gdb) tstart
 Sending packet: $QTinit#59...Packet received: OK
 Sending packet: $QTDP:1:00000000004004d9:E:1:0-#a4...Packet received: OK
 Sending packet: $QTDP👎00000000004004d9:R03FFFFFFFFFFFFFFFFFF#2b...Packet received: OK

The last "$QTDP:1:00000000004004d9:E:1:0-#a4" should be "$QTDP:1:00000000004004d9:E:0:0-#a3".
In pseudo-diff:

  -$QTDP:1:00000000004004d9:E:1:0-#a4
  +$QTDP:1:00000000004004d9:E:0:0-#a3

A related issue is that the "commands" command actually supports
setting commands to a range of breakpoints/tracepoints at once.  But,
hacking "maint info breakpoints" to print t->step_count, reveals:

 (gdb) trace main
 Tracepoint 5 at 0x45a2ab: file ../../src/gdb/gdb.c, line 29.
 (gdb) trace main
 Note: breakpoint 5 also set at pc 0x45a2ab.
 Tracepoint 6 at 0x45a2ab: file ../../src/gdb/gdb.c, line 29.
 (gdb) commands 5-6
 Type commands for breakpoint(s) 5-6, one per line.
 End with a line saying just "end".
 > while-stepping 5
  >end
 > end
 (gdb) maint info breakpoints 5
 Num     Type           Disp Enb Address            What
 5       tracepoint     keep y   0x000000000045a2ab in main at ../../src/gdb/gdb.c:29 inf 1
         step_count=5
         ^^^^^^^^^^^^
         while-stepping 5
         end
         not installed on target
 (gdb) maint info breakpoints 6
 Num     Type           Disp Enb Address            What
 6       tracepoint     keep y   0x000000000045a2ab in main at ../../src/gdb/gdb.c:29 inf 1
         step_count=0
         ^^^^^^^^^^^^
         while-stepping 5
         end
         not installed on target
 (gdb)

that tracepoint 6 doesn't end up with the correct step_count.

The issue is that here:

 static void
 do_map_commands_command (struct breakpoint *b, void *data)
 {
  struct commands_info *info = data;

  if (info->cmd == NULL)
    {
      struct command_line *l;

      if (info->control != NULL)
	l = copy_command_lines (info->control->body_list[0]);
      else
	{
	  struct cleanup *old_chain;
	  char *str;

	  str = xstrprintf (_("Type commands for breakpoint(s) "
			      "%s, one per line."),
			    info->arg);

	  old_chain = make_cleanup (xfree, str);

	  l = read_command_lines (str,
				  info->from_tty, 1,
				  (is_tracepoint (b)
				   ? check_tracepoint_command : 0),
				  b);

	  do_cleanups (old_chain);
	}

      info->cmd = alloc_counted_command_line (l);
    }

validate_actionline is never called for tracepoints other than the
first (the copy_command_lines path).  Right below, we have:

  /* If a breakpoint was on the list more than once, we don't need to
     do anything.  */
  if (b->commands != info->cmd)
    {
      validate_commands_for_breakpoint (b, info->cmd->commands);
      incref_counted_command_line (info->cmd);
      decref_counted_command_line (&b->commands);
      b->commands = info->cmd;
      observer_notify_breakpoint_modified (b);
    }

And validate_commands_for_breakpoint looks like the right place to put
a call; if we reset step_count there too, we have a nice central fix
for the first issue as well, because trace_actions_command calls
breakpoint_set_commands that also calls
validate_commands_for_breakpoint.

We end up calling validate_actionline twice for the first tracepoint,
since read_command_lines calls it too, through
check_tracepoint_command, but that should be harmless.

2013-04-04  Pedro Alves  <palves@redhat.com>
	    Hui Zhu  <hui@codesourcery.com>

	* breakpoint.c (validate_commands_for_breakpoint): If validating a
	tracepoint, reset its STEP_COUNT and call validate_actionline.

2013-04-04  Stan Shebs  <stan@codesourcery.com>
	    Pedro Alves  <palves@redhat.com>

	* gdb.trace/Makefile.in (PROGS): Add actions-changed.
	* gdb.trace/actions-changed.c: New file.
	* gdb.trace/actions-changed.exp: New file.
	* lib/trace-support.exp (gdb_trace_setactions): Rename to ...
	(gdb_trace_setactions_command): ... this.  Add "actions_command"
	parameter, and handle it.
	(gdb_trace_setactions, gdb_trace_setcommands): New procedures.
This commit is contained in:
Pedro Alves 2013-04-04 19:22:38 +00:00
parent 54a3d86564
commit c9a6ce02b5
7 changed files with 298 additions and 12 deletions

View File

@ -1,3 +1,9 @@
2013-04-04 Pedro Alves <palves@redhat.com>
Hui Zhu <hui@codesourcery.com>
* breakpoint.c (validate_commands_for_breakpoint): If validating a
tracepoint, reset its STEP_COUNT and call validate_actionline.
2013-04-03 Doug Evans <dje@google.com>
* dwarf2read.c (read_die_and_siblings_1): Renamed from

View File

@ -1142,12 +1142,25 @@ validate_commands_for_breakpoint (struct breakpoint *b,
{
if (is_tracepoint (b))
{
/* We need to verify that each top-level element of commands is
valid for tracepoints, that there's at most one
while-stepping element, and that while-stepping's body has
valid tracing commands excluding nested while-stepping. */
struct tracepoint *t = (struct tracepoint *) b;
struct command_line *c;
struct command_line *while_stepping = 0;
/* Reset the while-stepping step count. The previous commands
might have included a while-stepping action, while the new
ones might not. */
t->step_count = 0;
/* We need to verify that each top-level element of commands is
valid for tracepoints, that there's at most one
while-stepping element, and that the while-stepping's body
has valid tracing commands excluding nested while-stepping.
We also need to validate the tracepoint action line in the
context of the tracepoint --- validate_actionline actually
has side effects, like setting the tracepoint's
while-stepping STEP_COUNT, in addition to checking if the
collect/teval actions parse and make sense in the
tracepoint's context. */
for (c = commands; c; c = c->next)
{
if (c->control_type == while_stepping_control)
@ -1165,6 +1178,8 @@ validate_commands_for_breakpoint (struct breakpoint *b,
else
while_stepping = c;
}
validate_actionline (c->line, b);
}
if (while_stepping)
{

View File

@ -1,3 +1,14 @@
2013-04-04 Stan Shebs <stan@codesourcery.com>
Pedro Alves <palves@redhat.com>
* gdb.trace/Makefile.in (PROGS): Add actions-changed.
* gdb.trace/actions-changed.c: New file.
* gdb.trace/actions-changed.exp: New file.
* lib/trace-support.exp (gdb_trace_setactions): Rename to ...
(gdb_trace_setactions_command): ... this. Add "actions_command"
parameter, and handle it.
(gdb_trace_setactions, gdb_trace_setcommands): New procedures.
2013-04-04 Yao Qi <yao@codesourcery.com>
* gdb.server/server-kill.exp: Use command 'tstatus' instead of

View File

@ -3,9 +3,9 @@ srcdir = @srcdir@
.PHONY: all clean mostlyclean distclean realclean
PROGS = ax backtrace deltrace disconnected-tracing infotrace packetlen \
passc-dyn passcount report save-trace tfile tfind tracecmd tsv \
unavailable while-dyn while-stepping
PROGS = actions-changed ax backtrace deltrace disconnected-tracing \
infotrace packetlen passc-dyn passcount report save-trace tfile \
tfind tracecmd tsv unavailable while-dyn while-stepping
all info install-info dvi install uninstall installcheck check:
@echo "Nothing to be done for $@..."

View File

@ -0,0 +1,66 @@
/* This testcase is part of GDB, the GNU debugger.
Copyright 2013 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
int
end (int i)
{
}
int
subr2 (int parm)
{
int keeping, busy;
keeping = parm + parm;
busy = keeping * keeping;
return busy;
}
int
subr (int parm)
{
int keeping, busy;
keeping = parm + parm;
busy = keeping * keeping;
return busy;
}
main()
{
subr (1);
end (1);
subr (2);
end (2);
subr (3);
end (3);
subr (4);
end (4);
subr (5);
subr2 (5);
end (5);
subr (6);
subr2 (6);
end (6);
}

View File

@ -0,0 +1,174 @@
# Copyright 2013 Free Software Foundation, Inc.
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
load_lib trace-support.exp
standard_testfile
if {[prepare_for_testing $testfile.exp $testfile $srcfile debug]} {
return -1
}
proc test_actions_changed { } {
gdb_breakpoint "end"
gdb_test "trace subr" "Tracepoint .*" \
"tracepoint at subr"
# The first set of tests are regression tests for a GDB bug where
# the while-stepping count of a tracepoint would be left stale if
# the tracepoint's actions were redefined, and the new action list
# had no while-stepping action.
# First pass, define simple action.
with_test_prefix "1" {
gdb_trace_setactions "define simple action" \
"" \
"collect parm" "^$"
gdb_test_no_output "tstart"
gdb_test "continue" ".*Breakpoint \[0-9\]+, end \\(i=1\\) .*" \
"advance through tracing"
gdb_test "tstatus" ".*Collected 1 trace frame.*" \
"collected 1 trace frame"
gdb_test_no_output "tstop"
}
# Redefine action, run second trace.
with_test_prefix "2" {
gdb_trace_setactions "redefine simple action" \
"" \
"collect keeping, busy" "^$"
gdb_test_no_output "tstart"
gdb_test "continue" ".*Breakpoint \[0-9\]+, end \\(i=2\\) .*" \
"advance through tracing"
gdb_test "tstatus" ".*Collected 1 trace frame.*" \
"collected 1 trace frame"
gdb_test_no_output "tstop"
}
# Redefine to stepping action, run third trace.
with_test_prefix "3" {
gdb_trace_setactions "redefine to stepping action" \
"" \
"collect parm" "^$" \
"while-stepping 5" "^$" \
"collect parm" "^$" \
"end" "^$"
gdb_test_no_output "tstart"
gdb_test "continue" ".*Breakpoint \[0-9\]+, end \\(i=3\\) .*" \
"advance through tracing"
gdb_test "tstatus" ".*Collected 6 trace frames.*" \
"collected 6 trace frames"
gdb_test_no_output "tstop"
}
# Redefine to non-stepping, run fourth trace.
with_test_prefix "4" {
gdb_trace_setactions "redefine to non-stepping action" \
"" \
"collect parm" "^$"
gdb_test_no_output "tstart"
gdb_test "continue" ".*Breakpoint \[0-9\]+, end \\(i=4\\) .*" \
"advance through tracing"
gdb_test "tstatus" ".*Collected 1 trace frame.*" \
"collected 1 trace frame"
gdb_test_no_output "tstop"
}
# The following tests are related to the above, but use two
# tracepoints. They are regression tests for a GDB bug where only
# the first tracepoint would end up with the step count set.
# Store the first tracepoint's number.
gdb_test_no_output "set \$prev_tpnum=\$tpnum" "store previous \$tpnum"
# And here's the second tracepoint.
gdb_test "trace subr2" "Tracepoint .*" "tracepoint at subr2"
# Set a stepping action in both tracepoints, with the "commands"
# command.
with_test_prefix "5" {
gdb_trace_setcommands \
"redefine 2 tracepoints to stepping action, using commands" \
"\$prev_tpnum-\$tpnum" \
"collect parm" "^$" \
"while-stepping 5" "^$" \
"collect parm" "^$" \
"end" "^$"
gdb_test_no_output "tstart"
gdb_test "continue" ".*Breakpoint \[0-9\]+, end \\(i=5\\) .*" \
"advance through tracing"
gdb_test "tstatus" ".*Collected 12 trace frames.*" \
"collected 12 trace frames"
gdb_test_no_output "tstop"
}
# Redefine the actions of both tracepoints to non-stepping, also
# using the "commands" command.
with_test_prefix "6" {
gdb_trace_setcommands \
"redefine 2 tracepoints to non-stepping action, using commands" \
"\$prev_tpnum-\$tpnum" \
"collect parm" "^$"
gdb_test_no_output "tstart"
gdb_test "continue" ".*Breakpoint \[0-9\]+, end \\(i=6\\) .*" \
"advance through tracing"
gdb_test "tstatus" ".*Collected 2 trace frame.*" \
"collected 2 trace frames"
gdb_test_no_output "tstop"
}
}
# Check whether the target supports tracepoints.
clean_restart $testfile
if ![runto_main] {
fail "Can't run to main to check for trace support"
return -1
}
if ![gdb_target_supports_trace] {
unsupported "Current target does not support trace"
return -1;
}
test_actions_changed
return 0

View File

@ -86,23 +86,23 @@ proc gdb_delete_tracepoints {} {
}
}
#
# Procedure: gdb_trace_setactions
# Define actions for a tracepoint.
# Arguments:
# actions_command -- the command used to create the actions.
# either "actions" or "commands".
# testname -- identifying string for pass/fail output
# tracepoint -- to which tracepoint do these actions apply? (optional)
# tracepoint -- to which tracepoint(s) do these actions apply? (optional)
# args -- list of actions to be defined.
# Returns:
# zero -- success
# non-zero -- failure
proc gdb_trace_setactions { testname tracepoint args } {
proc gdb_trace_setactions_command { actions_command testname tracepoint args } {
global gdb_prompt;
set state 0;
set passfail "pass";
send_gdb "actions $tracepoint\n";
send_gdb "$actions_command $tracepoint\n";
set expected_result "";
gdb_expect 5 {
-re "No tracepoint number .*$gdb_prompt $" {
@ -165,6 +165,20 @@ proc gdb_trace_setactions { testname tracepoint args } {
}
}
# Define actions for a tracepoint, using the "actions" command. See
# gdb_trace_setactions_command.
#
proc gdb_trace_setactions { testname tracepoint args } {
eval gdb_trace_setactions_command "actions" {$testname} {$tracepoint} $args
}
# Define actions for a tracepoint, using the "commands" command. See
# gdb_trace_setactions_command.
#
proc gdb_trace_setcommands { testname tracepoint args } {
eval gdb_trace_setactions_command "commands" {$testname} {$tracepoint} $args
}
#
# Procedure: gdb_tfind_test
# Find a specified trace frame.