Notify about breakpoint modification when enabling/disabling single location

When a single breakpoint location enableness was modified by a CLI
command, observers were not notified about it. This issue is now fixed.

gdb/ChangeLog:

	* breakpoint.c (enable_disable_bp_num_loc): Notify observers.

gdb/testsuite/ChangeLog:

	* gdb.mi/mi-breakpoint-location-ena-dis.cc: New file.
	* gdb.mi/mi-breakpoint-location-ena-dis.exp: New file.

gdb/ChangeLog

@@ -1,3 +1,7 @@
+2018-07-25  Jan Vrany  <jan.vrany@fit.cvut.cz>
+
+	* breakpoint.c (enable_disable_bp_num_loc): Notify observers.
+
 2018-07-25  Joel Brobecker  <brobecker@adacore.com>
 
 	* MAINTAINERS (Global Maintainers): Add Tom Tromey.

gdb/breakpoint.c

@@ -14220,6 +14220,8 @@ enable_disable_bp_num_loc (int bp_num, int loc_num, bool enable)
 	target_disable_tracepoint (loc);
     }
   update_global_location_list (UGLL_DONT_INSERT);
+
+  gdb::observers::breakpoint_modified.notify (loc->owner);
 }
 
 /* Enable or disable a range of breakpoint locations.  BP_NUM is the

gdb/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2018-07-25  Jan Vrany  <jan.vrany@fit.cvut.cz>
+
+	* gdb.mi/mi-breakpoint-location-ena-dis.cc: New file.
+	* gdb.mi/mi-breakpoint-location-ena-dis.exp: New file.
+
 2018-07-20  Tom de Vries  <tdevries@suse.de>
 
 	* gdb.base/vla-optimized-out.c: Make noclone attribute conditional on

gdb/testsuite/gdb.mi/mi-breakpoint-location-ena-dis.cc

@@ -0,0 +1,36 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2018 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/>.  */
+
+static int
+add (int a, int b)
+{
+  return a + b;
+}
+
+static double
+add (double a, double b)
+{
+  return a + b;
+}
+
+int
+main (void)
+{
+  int i = add (3, 4);
+  double d = add (3.0, 4.0);
+  return 1;
+}

gdb/testsuite/gdb.mi/mi-breakpoint-location-ena-dis.exp

@@ -0,0 +1,56 @@
+# Copyright 2018 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/>.
+
+# Tests whether =breakpoint=modified notification is sent when a single
+# breakpoint location is enabled or disabled via CLI.
+
+load_lib mi-support.exp
+set MIFLAGS "-i=mi"
+
+gdb_exit
+if {[mi_gdb_start]} {
+    continue
+}
+
+#
+# Start here
+#
+standard_testfile .cc
+
+if {[gdb_compile "$srcdir/$subdir/$srcfile" $binfile executable {debug c++}] != "" } {
+    return -1
+}
+
+mi_run_to_main
+
+mi_gdb_test "break add" \
+	{(&.*)*.*~"Breakpoint 2 at.*\\n".*=breakpoint-created,bkpt=\{number="2",type="breakpoint".*\},\{number="2.1",enabled="y".*\}.*\n\^done} \
+	"break add"
+
+# Modify enableness through MI commands shouldn't trigger MI
+# notification.
+mi_gdb_test "-break-disable 2.2" "\\^done" "-break-disable 2.2"
+mi_gdb_test "-break-enable 2.2"  "\\^done" "-break-enable 2.2"
+
+# Modify enableness through CLI commands should trigger MI
+# notification.
+mi_gdb_test "dis 2.2" \
+	{.*=breakpoint-modified,bkpt=\{number="2",type="breakpoint".*\},\{number="2.1",enabled="y".*\},\{number="2.2",enabled="n".*\}.*\n\^done} \
+	"dis 2.2"
+mi_gdb_test "en 2.2" \
+	{.*=breakpoint-modified,bkpt=\{number="2",type="breakpoint".*\},\{number="2.1",enabled="y".*\},\{number="2.2",enabled="y".*\}.*\n\^done} \
+	"en 2.2"
+
+mi_gdb_exit