[PATCH 1/3] 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.

Regression tested on x86_64-linux with native and gdbserver.  Is it
OK?  Documentation part was approved by Eli here
<http://sourceware.org/ml/gdb-patches/2012-11/msg00193.html>

gdb/doc:

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

gdb:

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

	* NEWS: Mention it.

gdb/testsuite/

	* gdb.mi/mi-trace-changed.exp: New.
---
 gdb/NEWS                                     |    2 +
 gdb/doc/gdb.texinfo                          |    6 ++
 gdb/doc/observer.texi                        |    8 +++
 gdb/mi/mi-cmds.c                             |    6 +-
 gdb/mi/mi-interp.c                           |   46 ++++++++++++++
 gdb/mi/mi-main.h                             |    2 +
 gdb/testsuite/gdb.trace/mi-trace-changed.exp |   85 ++++++++++++++++++++++++++
 gdb/tracepoint.c                             |    4 +
 8 files changed, 157 insertions(+), 2 deletions(-)
 create mode 100644 gdb/testsuite/gdb.trace/mi-trace-changed.exp

diff --git a/gdb/NEWS b/gdb/NEWS
index 9912dc8..1c338f1 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -115,6 +115,8 @@ 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 8c59065..9b905b6 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -27965,6 +27965,12 @@ 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[,notes="@var{notes}"]
+@itemx =trace-stopped[,notes="@var{notes}"]
+Reports that trace was started or stopped.  The optional
+@code{notes="@var{notes}"} part is reported if trace notes or
+stop trace notes are not NULL.
 @end table
 
 @node GDB/MI Frame Information
diff --git a/gdb/doc/observer.texi b/gdb/doc/observer.texi
index 50038ac..e68aa79 100644
--- a/gdb/doc/observer.texi
+++ b/gdb/doc/observer.texi
@@ -246,6 +246,14 @@ 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_started (const char *@var{notes})
+The trace was started with trace notes @var{notes}.
+@end deftypefun
+
+@deftypefun void trace_stopped (const char *@var{notes})
+The trace was stopped with stop trace notes @var{notes}.
+@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 0e3cd6c..346f70c 100644
--- a/gdb/mi/mi-cmds.c
+++ b/gdb/mi/mi-cmds.c
@@ -147,9 +147,11 @@ 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 993f8b0..6b687e7 100644
--- a/gdb/mi/mi-interp.c
+++ b/gdb/mi/mi-interp.c
@@ -67,6 +67,8 @@ 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_started (const char *notes);
+static void mi_trace_stopped (const char *notes);
 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 +133,8 @@ 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_started (mi_trace_started);
+      observer_attach_trace_stopped (mi_trace_stopped);
       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 +598,48 @@ mi_tsv_deleted (const char *name)
   gdb_flush (mi->event_channel);
 }
 
+/* Emit notification on trace was started.  */
+
+static void
+mi_trace_started (const char *notes)
+{
+  struct mi_interp *mi = top_level_interpreter_data ();
+
+  if (mi_suppress_notification.trace)
+    return;
+
+  target_terminal_ours ();
+
+  if (notes != NULL)
+    fprintf_unfiltered (mi->event_channel, "trace-started,"
+			"notes=\"%s\"\n", notes);
+  else
+    fprintf_unfiltered (mi->event_channel, "trace-started\n");
+
+  gdb_flush (mi->event_channel);
+}
+
+/* Emit notification on trace was stopped.  */
+
+static void
+mi_trace_stopped (const char *notes)
+{
+  struct mi_interp *mi = top_level_interpreter_data ();
+
+  if (mi_suppress_notification.trace)
+    return;
+
+  target_terminal_ours ();
+
+  if (notes != NULL)
+    fprintf_unfiltered (mi->event_channel, "trace-stopped,"
+			"notes=\"%s\"\n", notes);
+  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 a815fbe..d56ce6a 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..7654638
--- /dev/null
+++ b/gdb/testsuite/gdb.trace/mi-trace-changed.exp
@@ -0,0 +1,85 @@
+# Copyright 2012 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"
+
+	mi_gdb_test "set trace-notes foo" \
+	    ".*=cmd-param-changed,param=\"trace-notes\",value=\"foo\".*\\^done" \
+	    "set trace notes"
+	# 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,notes=\"foo\".*\\^done" "start trace notification 1"
+	mi_gdb_test "tstop" ".*=trace-stopped\\\\n\r\n\\^done" \
+	    "stop trace notification 1"
+
+	mi_gdb_test "set trace-stop-notes bar" \
+	    ".*=cmd-param-changed,param=\"trace-stop-notes\",value=\"bar\".*\\^done" \
+	    "set trace stop notes"
+	mi_gdb_test "tstart" \
+	    ".*=trace-started,notes=\"foo\".*\\^done" "start trace notification 2"
+	mi_gdb_test "tstop" ".*=trace-stopped,notes=\"bar\".*\\^done" \
+	    "stop trace notification 2"
+
+	mi_gdb_exit
+    }
+}
+
+test_normal_tstart_stop
+
+return 0
diff --git a/gdb/tracepoint.c b/gdb/tracepoint.c
index f61ede7..2cfe549 100644
--- a/gdb/tracepoint.c
+++ b/gdb/tracepoint.c
@@ -1825,6 +1825,8 @@ start_tracing (char *notes)
   /* Now insert traps and begin collecting data.  */
   target_trace_start ();
 
+  observer_notify_trace_started (notes);
+
   /* Reset our local state.  */
   set_traceframe_num (-1);
   set_tracepoint_num (-1);
@@ -1910,6 +1912,8 @@ stop_tracing (char *note)
 
   /* Should change in response to reply?  */
   current_trace_status ()->running = 0;
+
+  observer_notify_trace_stopped (note);
 }
 
 /* tstatus command */
-- 
1.7.7.6