[PATCH 4/5] MI notification on trace started/stopped:basic

[Yao Qi <yao at codesourcery dot com>]

Hi,
This patch adds the notifications of 'trace-started' and
'trace-stopped', which are emitted when trace is started or stopped by
command 'tstart' and 'tstop', so that when trace is started or stopped
in console, MI frontend can be notified.

This patch doesn't handle the case the trace is stopped due to some
reasons in remote side, because we don't have any existing RSP
notification yet.  This issue will be addressed in another post.

Regression tested on x86_64-linux with native and gdbserver.  Is it
OK?

gdb/doc:

	* gdb.texinfo (GDB/MI Async Records): New MI notifications
	'trace-changed'.
	* observer.texi (GDB Observers): New observer 'trace-changed'

gdb:

	* mi/mi-cmds.c (mi_cmds): Adjust for commands 'trace-start'
	and 'trace-stop'.
	* mi/mi-interp.c: Declare mi_trace_changed.
	(mi_interpreter_init): Install mi_trace_changed to observer.
	(mi_trace_changed): New.
	* mi/mi-main.h (struct mi_suppress_notification) <trace>:
	New field.
	* tracepoint.c (start_tracing): Call
	observer_notify_trace_changed.
	(stop_tracing): Call observer_notify_trace_changed.

	* NEWS: Mention it.

gdb/testsuite/

	* gdb.mi/mi-trace-changed.exp: New.
---
 gdb/NEWS                                     |    2 +
 gdb/doc/gdb.texinfo                          |    4 ++
 gdb/doc/observer.texi                        |    6 ++
 gdb/mi/mi-cmds.c                             |    6 ++-
 gdb/mi/mi-interp.c                           |   22 ++++++++
 gdb/mi/mi-main.h                             |    2 +
 gdb/testsuite/gdb.trace/mi-trace-changed.exp |   74 ++++++++++++++++++++++++++
 gdb/tracepoint.c                             |    4 ++
 8 files changed, 118 insertions(+), 2 deletions(-)
 create mode 100644 gdb/testsuite/gdb.trace/mi-trace-changed.exp

diff --git a/gdb/NEWS b/gdb/NEWS
index 49d8447..ddeed5c 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -128,6 +128,8 @@ show print type typedefs
   ** The response to breakpoint commands and breakpoint async records
      includes an "installed" field containing a boolean state about each
      non-pending tracepoint location is whether installed on target or not.
+  ** The start and stop of trace are now notified using new async records
+     "=trace-started" and "=trace-stopped".
 
 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
   You must have the LZMA library available when configuring GDB for this
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index c41310d..f1ac4e1 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -27967,6 +27967,10 @@ written in an inferior.  The @var{id} is the identifier of the
 thread group corresponding to the affected inferior.  The optional
 @code{type="code"} part is reported if the memory written to holds
 executable code.
+
+@item =trace-started
+@itemx =trace-stopped
+Reports that trace was started or stopped.
 @end table
 
 @node GDB/MI Breakpoint Information
diff --git a/gdb/doc/observer.texi b/gdb/doc/observer.texi
index 87c08e1..2f3c99c 100644
--- a/gdb/doc/observer.texi
+++ b/gdb/doc/observer.texi
@@ -246,6 +246,12 @@ The trace state variable @var{name} is deleted.  If @var{name} is
 @code{NULL}, all trace state variables are deleted.
 @end deftypefun
 
+@deftypefun void trace_changed (int @var{started})
+The status of trace in @value{GDBN} has changed.  The trace is started
+if @var{started} is true, and the trace is stopped if @var{started} is
+false.
+@end deftypefun
+
 @deftypefun void test_notification (int @var{somearg})
 This observer is used for internal testing.  Do not use.  
 See testsuite/gdb.gdb/observer.exp.
diff --git a/gdb/mi/mi-cmds.c b/gdb/mi/mi-cmds.c
index df173fe..f2c037d 100644
--- a/gdb/mi/mi-cmds.c
+++ b/gdb/mi/mi-cmds.c
@@ -146,9 +146,11 @@ static struct mi_cmd mi_cmds[] =
 		   &mi_suppress_notification.traceframe),
   DEF_MI_CMD_MI ("trace-list-variables", mi_cmd_trace_list_variables),
   DEF_MI_CMD_MI ("trace-save", mi_cmd_trace_save),
-  DEF_MI_CMD_MI ("trace-start", mi_cmd_trace_start),
+  DEF_MI_CMD_MI_1 ("trace-start", mi_cmd_trace_start,
+		   &mi_suppress_notification.trace),
   DEF_MI_CMD_MI ("trace-status", mi_cmd_trace_status),
-  DEF_MI_CMD_MI ("trace-stop", mi_cmd_trace_stop),
+  DEF_MI_CMD_MI_1 ("trace-stop", mi_cmd_trace_stop,
+		   &mi_suppress_notification.trace),
   DEF_MI_CMD_MI ("var-assign", mi_cmd_var_assign),
   DEF_MI_CMD_MI ("var-create", mi_cmd_var_create),
   DEF_MI_CMD_MI ("var-delete", mi_cmd_var_delete),
diff --git a/gdb/mi/mi-interp.c b/gdb/mi/mi-interp.c
index 6617647..a74d782 100644
--- a/gdb/mi/mi-interp.c
+++ b/gdb/mi/mi-interp.c
@@ -67,6 +67,7 @@ static void mi_inferior_appeared (struct inferior *inf);
 static void mi_inferior_exit (struct inferior *inf);
 static void mi_inferior_removed (struct inferior *inf);
 static void mi_on_resume (ptid_t ptid);
+static void mi_trace_changed (int started);
 static void mi_solib_loaded (struct so_list *solib);
 static void mi_solib_unloaded (struct so_list *solib);
 static void mi_about_to_proceed (void);
@@ -131,6 +132,7 @@ mi_interpreter_init (struct interp *interp, int top_level)
       observer_attach_record_changed (mi_record_changed);
       observer_attach_normal_stop (mi_on_normal_stop);
       observer_attach_target_resumed (mi_on_resume);
+      observer_attach_trace_changed (mi_trace_changed);
       observer_attach_solib_loaded (mi_solib_loaded);
       observer_attach_solib_unloaded (mi_solib_unloaded);
       observer_attach_about_to_proceed (mi_about_to_proceed);
@@ -594,6 +596,26 @@ mi_tsv_deleted (const char *name)
   gdb_flush (mi->event_channel);
 }
 
+/* Emit notification on trace was started or stopped.  */
+
+static void
+mi_trace_changed (int started)
+{
+  struct mi_interp *mi = top_level_interpreter_data ();
+
+  if (mi_suppress_notification.trace)
+    return;
+
+  target_terminal_ours ();
+
+  if (started)
+    fprintf_unfiltered (mi->event_channel, "trace-started\n");
+  else
+    fprintf_unfiltered (mi->event_channel, "trace-stopped\n");
+
+  gdb_flush (mi->event_channel);
+}
+
 /* Emit notification about a created breakpoint.  */
 
 static void
diff --git a/gdb/mi/mi-main.h b/gdb/mi/mi-main.h
index d75526a..0903d60 100644
--- a/gdb/mi/mi-main.h
+++ b/gdb/mi/mi-main.h
@@ -43,6 +43,8 @@ struct mi_suppress_notification
   int traceframe;
   /* Memory changed notification suppressed?  */
   int memory;
+  /* Trace started/stopped notification suppressed?  */
+  int trace;
 };
 extern struct mi_suppress_notification mi_suppress_notification;
 
diff --git a/gdb/testsuite/gdb.trace/mi-trace-changed.exp b/gdb/testsuite/gdb.trace/mi-trace-changed.exp
new file mode 100644
index 0000000..fbd6fe7
--- /dev/null
+++ b/gdb/testsuite/gdb.trace/mi-trace-changed.exp
@@ -0,0 +1,74 @@
+# 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 mi-support.exp
+load_lib trace-support.exp
+
+standard_testfile status-stop.c
+
+if { [gdb_compile "$srcdir/$subdir/$srcfile" $binfile \
+	  executable {debug nowarnings}] != "" } {
+    untested mi-record-changed.exp
+    return -1
+}
+
+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 "target does not support trace"
+    return -1;
+}
+
+gdb_exit
+
+# Verify that MI notification '=trace-started' and '=trace-stopped' are
+# emitted for normal 'tstart' and 'tstart' command.
+
+proc test_normal_tstart_stop { } {
+    with_test_prefix "tstart_tstop" {
+	global decimal hex
+
+	if [mi_gdb_start] {
+	    return
+	}
+	mi_run_to_main
+
+	mi_gdb_test "-break-insert -a main" {.*\^done,bkpt=.*} \
+	    "insert tracepoint on main"
+
+	# No =trace-started notification.
+	mi_gdb_test "-trace-start" "-trace-start\r\n=breakpoint-modified\[^\n\]+\r\n\\^done" \
+	    "start trace without notification"
+	mi_gdb_test "-trace-stop" \
+	    "-trace-stop\r\n\\^done,stop-reason=\"request\".*" \
+	    "stop trace without notification"
+
+	mi_gdb_test "tstart" \
+	    ".*=trace-started.*\\^done" "start trace notification"
+	mi_gdb_test "tstop" ".*=trace-stopped\\\\n\r\n\\^done" \
+	    "stop trace notification"
+
+	mi_gdb_exit
+    }
+}
+
+test_normal_tstart_stop
+
+return 0
diff --git a/gdb/tracepoint.c b/gdb/tracepoint.c
index be45cb4..39b3822 100644
--- a/gdb/tracepoint.c
+++ b/gdb/tracepoint.c
@@ -1819,6 +1819,8 @@ start_tracing (char *notes)
   /* Now insert traps and begin collecting data.  */
   target_trace_start ();
 
+  observer_notify_trace_changed (1);
+
   /* Reset our local state.  */
   set_traceframe_num (-1);
   set_tracepoint_num (-1);
@@ -1904,6 +1906,8 @@ stop_tracing (char *note)
 
   /* Should change in response to reply?  */
   current_trace_status ()->running = 0;
+
+  observer_notify_trace_changed (0);
 }
 
 /* tstatus command */
-- 
1.7.7.6