[v6] Events when inferior is modified

diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index cbec0d2..cdfb889 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -360,6 +360,7 @@  SUBDIR_PYTHON_OBS = \
  	py-framefilter.o \
  	py-function.o \
  	py-gdb-readline.o \
+	py-infcallevent.o \
  	py-inferior.o \
  	py-infthread.o \
  	py-lazy-string.o \
@@ -398,6 +399,7 @@  SUBDIR_PYTHON_SRCS = \
  	python/py-framefilter.c \
  	python/py-function.c \
  	python/py-gdb-readline.c \
+	python/py-infcallevent.c \
  	python/py-inferior.c \
  	python/py-infthread.c \
  	python/py-lazy-string.c \
@@ -2475,6 +2477,10 @@  py-gdb-readline.o: $(srcdir)/python/py-gdb-readline.c
  	$(COMPILE) $(PYTHON_CFLAGS) $(srcdir)/python/py-gdb-readline.c
  	$(POSTCOMPILE)

+py-infcallevent.o: $(srcdir)/python/py-infcallevent.c
+	$(COMPILE) $(PYTHON_CFLAGS) $(srcdir)/python/py-infcallevent.c
+	$(POSTCOMPILE)
+
  py-inferior.o: $(srcdir)/python/py-inferior.c
  	$(COMPILE) $(PYTHON_CFLAGS) $(srcdir)/python/py-inferior.c
  	$(POSTCOMPILE)
diff --git a/gdb/NEWS b/gdb/NEWS
index 343ee49..3fc06f4 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -38,6 +38,16 @@  queue-signal signal-name-or-number
  -D data-directory
    This is an alias for the --data-directory option.

+* Python Scripting
+
+  New events which are triggered when GDB modifies the state of the
+  inferior.
+
+  ** gdb.events.inferior_call_pre Function call is about to be made.
+  ** gdb.events.inferior_call_post Function call has just been made.
+  ** gdb.events.memory_changed A memory location has been altered.
+  ** gdb.events.register_changed A register has been altered.
+
  * GDB supports printing and modifying of variable length automatic arrays
    as specified in ISO C99.

diff --git a/gdb/doc/observer.texi b/gdb/doc/observer.texi
index 2757587..2bc006c 100644
--- a/gdb/doc/observer.texi
+++ b/gdb/doc/observer.texi
@@ -281,6 +281,18 @@  The trace state variable @var{tsv} is deleted.  If 
@var{tsv} is
  The trace state value @var{tsv} is modified.
  @end deftypefun

+@deftypefun void inferior_call_pre (void)
+An inferior function is about to be called.
+@end deftypefun
+
+@deftypefun void inferior_call_post (void)
+An inferior function has just been called.
+@end deftypefun
+
+@deftypefun void register_changed (struct frame_info *@var{frame}, 
short @var{regnum})
+A register in the inferior has been modified.
+@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/doc/python.texi b/gdb/doc/python.texi
index 9f44948..fb7c682 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -2728,6 +2728,39 @@  A reference to the object file 
(@code{gdb.Objfile}) which has been loaded.
  @xref{Objfiles In Python}, for details of the @code{gdb.Objfile} object.
  @end defvar

+@item events.inferior_call_pre
+Emits @code{gdb.InferiorCallPreEvent} which indicates that a function in
+the inferior is about to be called.
+
+@item events.inferior_call_post
+Emits @code{gdb.InferiorCallPostEvent} which indicates that a function in
+the inferior has returned.
+
+@item events.memory_changed
+Emits @code{gdb.MemoryChangedEvent} which indicates that the memory of the
+inferior has been modified by the @value{GDBN} user, for instance via a
+command like @w{@code{set *addr = value}}.  The event has the following
+attributes:
+
+@defvar MemoryChangedEvent.address
+The start address of the changed region.
+@end defvar
+
+@defvar MemoryChangedEvent.length
+Length in bytes of the changed region.
+@end defvar
+
+@item events.register_changed
+Emits @code{gdb.RegisterChangedEvent} which indicates that a register 
in the
+inferior has been modified by the @value{GDBN} user.
+
+@defvar RegisterChangedEvent.frame
+A gdb.Frame object representing the frame in which the register was 
modified.
+@end defvar
+@defvar RegisterChangedEvent.regnum
+Denotes which register was modified.
+@end defvar
+
  @end table

  @node Threads In Python
diff --git a/gdb/infcall.c b/gdb/infcall.c
index e60d1d4..a221e77 100644
--- a/gdb/infcall.c
+++ b/gdb/infcall.c
@@ -36,6 +36,7 @@ 
  #include "gdbthread.h"
  #include "exceptions.h"
  #include "event-top.h"
+#include "observer.h"

  /* If we can't find a function's name from its address,
     we print this instead.  */
@@ -627,6 +628,8 @@  call_function_by_hand (struct value *function, int 
nargs, struct value **args)
        target_values_type = values_type;
      }

+  observer_notify_inferior_call_pre ();
+
    /* Determine the location of the breakpoint (and possibly other
       stuff) that the called function will return to.  The SPARC, for a
       function returning a structure or union, needs to make space for
@@ -860,6 +863,8 @@  call_function_by_hand (struct value *function, int 
nargs, struct value **args)
      e = run_inferior_call (tp, real_pc);
    }

+  observer_notify_inferior_call_post ();
+
    /* Rethrow an error if we got one trying to run the inferior.  */

    if (e.reason < 0)
diff --git a/gdb/python/py-event.h b/gdb/python/py-event.h
index 5a0f29b..39aee99 100644
--- a/gdb/python/py-event.h
+++ b/gdb/python/py-event.h
@@ -105,6 +105,16 @@  typedef struct
  extern int emit_continue_event (ptid_t ptid);
  extern int emit_exited_event (const LONGEST *exit_code, struct 
inferior *inf);

+typedef enum
+{
+  inferior_call_pre,
+  inferior_call_post,
+} inferior_call_kind;
+
+extern int emit_inferior_call_event (inferior_call_kind kind);
+extern int emit_register_changed_event (struct frame_info *frame,
+					short regnum);
+extern int emit_memory_changed_event (CORE_ADDR addr, ssize_t len);
  extern int evpy_emit_event (PyObject *event,
                              eventregistry_object *registry)
    CPYCHECKER_STEALS_REFERENCE_TO_ARG (1);
diff --git a/gdb/python/py-events.h b/gdb/python/py-events.h
index 3431612..e219305 100644
--- a/gdb/python/py-events.h
+++ b/gdb/python/py-events.h
@@ -46,6 +46,9 @@  typedef struct
    eventregistry_object *cont;
    eventregistry_object *exited;
    eventregistry_object *new_objfile;
+  eventregistry_object *inferior_call;
+  eventregistry_object *memory_changed;
+  eventregistry_object *register_changed;

    PyObject *module;

diff --git a/gdb/python/py-evts.c b/gdb/python/py-evts.c
index a7daf8a..1825464 100644
--- a/gdb/python/py-evts.c
+++ b/gdb/python/py-evts.c
@@ -73,6 +73,18 @@  gdbpy_initialize_py_events (void)
    if (add_new_registry (&gdb_py_events.exited, "exited") < 0)
      return -1;

+  if (add_new_registry (&gdb_py_events.inferior_call,
+			"inferior_call") < 0)
+    return -1;
+
+  if (add_new_registry (&gdb_py_events.memory_changed,
+			"memory_changed") < 0)
+    return -1;
+
+  if (add_new_registry (&gdb_py_events.register_changed,
+			"register_changed") < 0)
+    return -1;
+
    if (add_new_registry (&gdb_py_events.new_objfile, "new_objfile") < 0)
      return -1;

diff --git a/gdb/python/py-inferior.c b/gdb/python/py-inferior.c
index 9b8b8f5..27d2ffc 100644
--- a/gdb/python/py-inferior.c
+++ b/gdb/python/py-inferior.c
@@ -118,6 +118,58 @@  python_on_resume (ptid_t ptid)
  }

  static void
+python_on_inferior_call_pre (void)
+{
+  struct cleanup *cleanup;
+
+  cleanup = ensure_python_env (target_gdbarch (), current_language);
+
+  if (emit_inferior_call_event (inferior_call_pre) < 0)
+    gdbpy_print_stack ();
+
+  do_cleanups (cleanup);
+}
+
+static void
+python_on_inferior_call_post (void)
+{
+  struct cleanup *cleanup;
+
+  cleanup = ensure_python_env (target_gdbarch (), current_language);
+
+  if (emit_inferior_call_event (inferior_call_post) < 0)
+    gdbpy_print_stack ();
+
+  do_cleanups (cleanup);
+}
+
+static void
+python_on_memory_change (struct inferior *inferior, CORE_ADDR addr, 
ssize_t len, const bfd_byte *data)
+{
+  struct cleanup *cleanup;
+
+  cleanup = ensure_python_env (target_gdbarch (), current_language);
+
+  if (emit_memory_changed_event (addr, len) < 0)
+    gdbpy_print_stack ();
+
+  do_cleanups (cleanup);
+}
+
+static void
+python_on_register_change (struct frame_info *frame, short regnum)
+{
+  struct cleanup *cleanup;
+
+  cleanup = ensure_python_env (target_gdbarch (), current_language);
+
+  if (emit_register_changed_event (frame, regnum) < 0)
+    gdbpy_print_stack ();
+
+  do_cleanups (cleanup);
+}
+
+static void
  python_inferior_exit (struct inferior *inf)
  {
    struct cleanup *cleanup;
@@ -794,6 +846,10 @@  gdbpy_initialize_inferior (void)
    observer_attach_thread_exit (delete_thread_object);
    observer_attach_normal_stop (python_on_normal_stop);
    observer_attach_target_resumed (python_on_resume);
+  observer_attach_inferior_call_pre (python_on_inferior_call_pre);
+  observer_attach_inferior_call_post (python_on_inferior_call_post);
+  observer_attach_memory_changed (python_on_memory_change);
+  observer_attach_register_changed (python_on_register_change);
    observer_attach_inferior_exit (python_inferior_exit);
    observer_attach_new_objfile (python_new_objfile);

diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index 6e7e600..822eb6e 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -466,6 +466,14 @@  int gdbpy_initialize_breakpoint_event (void)
    CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
  int gdbpy_initialize_continue_event (void)
    CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
+int gdbpy_initialize_inferior_call_pre_event (void)
+  CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
+int gdbpy_initialize_inferior_call_post_event (void)
+  CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
+int gdbpy_initialize_register_changed_event (void)
+  CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
+int gdbpy_initialize_memory_changed_event (void)
+  CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
  int gdbpy_initialize_exited_event (void)
    CPYCHECKER_NEGATIVE_RESULT_SETS_EXCEPTION;
  int gdbpy_initialize_thread_event (void)
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 40c4ec9..68e3af8 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -1754,6 +1754,10 @@  message == an error message without a stack will 
be printed."),
        || gdbpy_initialize_signal_event () < 0
        || gdbpy_initialize_breakpoint_event () < 0
        || gdbpy_initialize_continue_event () < 0
+      || gdbpy_initialize_inferior_call_pre_event () < 0
+      || gdbpy_initialize_inferior_call_post_event () < 0
+      || gdbpy_initialize_register_changed_event () < 0
+      || gdbpy_initialize_memory_changed_event () < 0
        || gdbpy_initialize_exited_event () < 0
        || gdbpy_initialize_thread_event () < 0
        || gdbpy_initialize_new_objfile_event ()  < 0
diff --git a/gdb/testsuite/gdb.python/py-events.exp 
b/gdb/testsuite/gdb.python/py-events.exp
index 92de550..ec9c840 100644
--- a/gdb/testsuite/gdb.python/py-events.exp
+++ b/gdb/testsuite/gdb.python/py-events.exp
@@ -79,6 +79,92 @@  all threads stopped"

  delete_breakpoints

+# Test inferior call events
+gdb_test "call do_nothing()" ".*event type: pre-call.*
+.*event type: post-call.*"
+
+# Test register changed event
+gdb_test_no_output {set $old_sp = $sp}
+gdb_test {set $sp = 0} ".*event type: register-changed.*
+.*frame: .*
+.*num: .*"
+gdb_test {set $sp = 1} ".*event type: register-changed.*
+.*frame: .*
+.*num: .*"
+gdb_test {set $sp = $old_sp} ".*event type: register-changed.*
+.*frame: .*
+.*num: .*"
+
+# Test that no register_changed event is generated on "non-user"
+# modifications
+set test "up"
+gdb_test_multiple {up} $test {
+    -re "event type: register-changed" {
+	fail $test
+    }
+    -re "#1.*in first.*\r\n.*do_nothing.*\r\n$gdb_prompt $" {
+	pass $test
+    }
+}
+
+set test "down"
+gdb_test_multiple {down} $test {
+    -re "event type: register-changed" {
+	fail $test
+    }
+    -re "#0.*do_nothing.*at.*\r\n.*void do_nothing.*\r\n$gdb_prompt $" {
+	pass $test
+    }
+}
+
+set test "step"
+gdb_test_multiple {step} $test {
+    -re "event type: register-changed" {
+	fail $test
+    }
+    -re "first.*at.*\r\n.*28.*for.*\r\n$gdb_prompt $" {
+	pass $test
+    }
+}
+
+
+# Test memory changed event
+gdb_test_no_output {set $saved = *(int*) $sp}
+gdb_test {set *(int*) $sp = 0} ".*event type: memory-changed.*
+.*address: .*
+.*length: .*"
+gdb_test {set *(int*) $sp = $saved} ".*event type: memory-changed.*
+.*address: .*
+.*length: .*"
+
+# Test that no memory_changed event is generated on breakpoint
+# activity
+set test "break second"
+gdb_test_multiple "break second" $test {
+     -re "event type: memory-changed" {
+	fail $test
+    }
+    -re "Breakpoint 5 at .*\r\n$gdb_prompt $" {
+	pass $test
+    }
+
+}
+
+set test "continue to breakpoint 5"
+gdb_test_multiple "continue" $test {
+     -re "event type: memory-changed" {
+	fail $test
+    }
+    -re ".*event type: continue.*
+.*event type: stop.*
+.*stop reason: breakpoint.*
+.*all threads stopped.*$gdb_prompt $" {
+	pass $test
+    }
+}
+
+gdb_test_no_output "delete 5"
+
  #test exited event.
  gdb_test "continue" ".*event type: continue.*
  .*event type: exit.*
diff --git a/gdb/testsuite/gdb.python/py-events.py 
b/gdb/testsuite/gdb.python/py-events.py
index 1f0012a..94f91ac 100644
--- a/gdb/testsuite/gdb.python/py-events.py
+++ b/gdb/testsuite/gdb.python/py-events.py
@@ -57,6 +57,28 @@  def new_objfile_handler (event):
      print ("event type: new_objfile")
      print ("new objfile name: %s" % (event.new_objfile.filename))

+def inferior_fn_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
+
+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."""

@@ -68,6 +90,9 @@  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_fn_handler)
+        gdb.events.memory_changed.connect(memory_changed_handler)
+        gdb.events.register_changed.connect(register_changed_handler)
          print ("Event testers registered.")

  test_events ()
diff --git a/gdb/valops.c b/gdb/valops.c
index e1decf0..bc4d838 100644
--- a/gdb/valops.c
+++ b/gdb/valops.c
@@ -1168,6 +1168,7 @@  value_assign (struct value *toval, struct value 
*fromval)
  	      }
  	  }

+	observer_notify_register_changed (frame, value_reg);
  	if (deprecated_register_changed_hook)
  	  deprecated_register_changed_hook (-1);