New python events: inferior call, register/memory changed.

gdb/ChangeLog:

	* NEWS: Mention new Python events.
	* Makefile.in (SUBDIR_PYTHON_OBS): Add py-infevents.o.
	(SUBDIR_PYTHON_SRCS): Add py-infevents.c.
	(py-infevents.o): New rule.
	* doc/observer.texi (inferior_call_pre, inferior_call_post)
	(memory_changed, register_changed): New observers.
	* infcall.c (call_function_by_hand): Notify observer before and
	after inferior call.
	* python/py-event.h (inferior_call_kind): New enum.
	(emit_inferior_call_event): New prototype.
	(emit_register_changed_event): New prototype.
	(emit_memory_changed_event): New prototype.
	* python/py-events.h (events_object): New registries
	inferior_call, memory_changed and register_changed.
	* python/py-evts.c (gdbpy_initialize_py_events): Add the
	inferior_call, memory_changed and register_changed registries.
	* python/py-infevents.c: New.
	* python/py-inferior.c (python_on_inferior_call_pre)
	(python_on_inferior_call_post, python_on_register_change)
	(python_on_memory_change): New functions.
	(gdbpy_initialize_inferior): Attach python handler to new
	observers.
	* python/py-infthread.c(gdbpy_create_ptid_object): New.
	(thpy_get_ptid) Use gdbpy_create_ptid_object.
	* python/python-internal.h:
	(gdbpy_create_ptid_object)
	(gdbpy_initialize_inferior_call_pre_event)
	(gdbpy_initialize_inferior_call_post_event)
	(gdbpy_initialize_register_changed_event)
	(gdbpy_initialize_memory_changed_event): New prototypes.
	* python/python.c (_initialize_python): Initialize new events.
	* valops.c (value_assign): Notify register_changed observer.

gdb/doc/ChangeLog:

	* python.texi (Events In Python): Document new events
	InferiorCallPreEvent, InferiorCallPostEvent, MemoryChangedEvent
	and RegisterChangedEvent.

gdb/testsuite/ChangeLog:

	* gdb.python/py-events.py (inferior_call_handler): New.
	(register_changed_handler, memory_changed_handler): New.
	(test_events.invoke): Register new handlers.
	* gdb.python/py-events.exp: Add tests for inferior call,
	memory_changed and register_changed events.

gdb/testsuite/gdb.python/py-events.py

@@ -62,6 +62,30 @@ def clear_objfiles_handler (event):
     print ("event type: clear_objfiles")
     print ("progspace: %s" % (event.progspace.filename))
 
+def inferior_call_handler (event):
+    if (isinstance (event, gdb.InferiorCallPreEvent)):
+        print ("event type: pre-call")
+    elif (isinstance (event, gdb.InferiorCallPostEvent)):
+        print ("event type: post-call")
+    else:
+        assert False
+    print ("ptid: %s" % (event.ptid,))
+    print ("address: 0x%x" % (event.address))
+
+def register_changed_handler (event):
+    assert (isinstance (event, gdb.RegisterChangedEvent))
+    print ("event type: register-changed")
+    assert (isinstance (event.frame, gdb.Frame))
+    print ("frame: %s" % (event.frame))
+    print ("num: %s" % (event.regnum))
+
+def memory_changed_handler (event):
+    assert (isinstance (event, gdb.MemoryChangedEvent))
+    print ("event type: memory-changed")
+    print ("address: %s" % (event.address))
+    print ("length: %s" % (event.length))
+
+
 class test_events (gdb.Command):
     """Test events."""
 
@@ -73,6 +97,9 @@ class test_events (gdb.Command):
         gdb.events.stop.connect (breakpoint_stop_handler)
         gdb.events.exited.connect (exit_handler)
         gdb.events.cont.connect (continue_handler)
+        gdb.events.inferior_call.connect (inferior_call_handler)
+        gdb.events.memory_changed.connect (memory_changed_handler)
+        gdb.events.register_changed.connect (register_changed_handler)
         print ("Event testers registered.")
 
 test_events ()