try to update source window when breakpoints change

this is not tested yet

gui/bpcache.py

@@ -0,0 +1,57 @@
+# Copyright (C) 2015 Tom Tromey <tom@trolley.com>
+
+# 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/>.
+
+import gdb
+import gui.events
+import gui.adapt
+
+# This maps from (FILENAME,LINE) to a set of breakpoints referencing
+# that file/line.  Then we emit events when entries are created or
+# destroyed.
+breakpoint_source_map = {}
+
+def _breakpoint_created(bp):
+    if bp.location is None:
+        return
+    gui.adapt.notify_bug(18385)
+    (rest, locs) = gdb.decode_line(bp.location)
+    if rest is not None:
+        # Let's assume we couldn't reparse for some reason.
+        return
+    for sal in locs:
+        if sal.symtab is None:
+            continue
+        entry = (sal.symtab.fullname(), sal.line)
+        if entry not in breakpoint_source_map:
+            breakpoint_source_map[entry] = set()
+        if bp.number not in breakpoint_source_map[entry]:
+            breakpoint_source_map[entry].add(bp.number)
+            gui.events.location_changed.post(entry, True)
+        else:
+            breakpoint_source_map[entry].add(bp.number)
+
+def _breakpoint_deleted(bp):
+    num = bp.number
+    for entry in breakpoint_source_map:
+        if num in breakpoint_source_map[entry]:
+            breakpoint_source_map[entry].discard(bp.number)
+            if len(breakpoint_source_map[entry]) == 0:
+                gui.events.location_changed.post(entry, False)
+
+if not hasattr(gdb.events, 'breakpoint_created'):
+    gui.adapt.notify_bug(15620)
+else:
+    gdb.events.breakpoint_created.connect(_breakpoint_created)
+    gdb.events.breakpoint_deleted.connect(_breakpoint_deleted)