Re: [RFC] Python Finish Breakpoints

[Kevin Pouget <kevin.pouget@gmail.com>]

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Hello,

thanks for you comments, I replied inline:


> Kevin> -static void
> Kevin> +void
> Kevin>  create_breakpoint_sal (struct gdbarch *gdbarch,
> Kevin>                         struct symtabs_and_lines sals, char *addr_string,
> Kevin>                         char *cond_string,
>
> What is the rationale for using this function in particular?
>
> It seems to me that it would probably be better to make an explicit_pc=1
> SAL using the unwound PC.  Then there would be no reason to avoid the
> currently exported API.

There isn't. I just followed the "finish" command implementation and
understood that this function looked like what I was looking for!
I re-wrote this part of the code to use the existing API

> Kevin> -  if (inferior_thread ()->control.proceed_to_finish)
> Kevin> +  if (gdbpy_is_stopped_at_finish_bp (inferior_thread ()->control.stop_bpstat)
> Kevin> +      || inferior_thread ()->control.proceed_to_finish)
>
> gdbpy_is_stopped_at_finish_bp is not safe to call here -- it assumes the
> GIL has been acquired, which it has not.  I would rather it not be changed
> to acquire the GIL, however.  I think one of two other approaches would
> be preferable.
>
> One way you could handle this is to add a new constant to enum bptype.
> This is likely to be pretty invasive.
>
> Another way would be to add a flag to the struct breakpoint itself.
>
> Yet another way would be a new breakpoint_ops method.

you're right; I chose the second way,

breakpoint.h:
enum py_bp_type
  {
    py_bp_none,         /* No Python object.  */
    py_bp_standard,     /* Ordinary breakpoint object.  */
    py_bp_finish        /* FinishBreakpoint object.  */
  };

    /* Type of the Python Breakpoint object stored in `py_bp_object'.  */
    enum py_bp_type py_bp_type;

py-breakpoint.c:
gdbpy_is_stopped_at_bp_type (bpstat stop_bpstat, enum py_bp_type type)

so that it doesn't require GIL state handling

> This is related, in a way, to the out-of-scope handling.  Right now the
> patch tries to reimplement the existing breakpoint re-setting logic in
> py-finishbreakpoint.c, via observers.  I think it would be better to
> have this be done automatically by the existing code in breakpoint.c,
> perhaps adding some additional python-visible notification step.

I'm not sure what you're talking about; I re-explain and document this
aspect at the bottom of the mail, you'll tell me if this is still
relevant

> Kevin> +static char * const outofscope_func = "out_of_scope";
>
> "const char *".

I copied it from py-breakpoint.c:
> static char * const stop_func = "stop";

and I think thank we can't change it, otherwise it conflicts with
> PyObject* PyObject_CallMethod(PyObject *o, char *method, char *format, ...)

and creates a compiler warning


> Kevin> +  /* The function finished by this breakpoint.  */
> Kevin> +  struct symbol *function;
>
> If you want to store a pointer to a symbol, then you have to account for
> the case where the objfile is destroyed.  Otherwise you can end up with
> a dangling pointer.
>
> Alternatively, perhaps you could have this refer to a Symbol object; but
> then you have to be careful to check it for validity before using it.
>
> Actually, it seems that the symbol is only used to get the function's
> return type.  You might as well just compute that up front and store a
> Type.

> Kevin> +/* Python function to get the 'return_value' attribute of
> Kevin> +   FinishBreakpoint.  */
> Kevin> +
> Kevin> +static PyObject *
> Kevin> +bpfinishpy_get_returnvalue (PyObject *self, void *closure)
> Kevin> +{
> Kevin> +  struct finish_breakpoint_object *self_finishbp =
> Kevin> +      (struct finish_breakpoint_object *) self;
> Kevin> +
> Kevin> +  BPPY_REQUIRE_VALID (&self_finishbp->py_bp);
> Kevin> +
> Kevin> +  if (self_finishbp->function == NULL)
> Kevin> +    goto return_none;
> Kevin> +
> Kevin> +  /* Ensure that GDB is stopped at this FinishBreakpoint.  */
> Kevin> +  if (inferior_thread ()->control.stop_bpstat != NULL)
> Kevin> +    {
> Kevin> +      bpstat bs;
> Kevin> +
> Kevin> +      for(bs = inferior_thread ()->control.stop_bpstat;
> Kevin> +          bs; bs = bs->next)
>
> I am not an expert here, but I think it is probably no good to rely on
> this state remaining live.
>
> I think it would be better to simply have a stop at one of these
> breakpoints compute and cache the Value object immediately.

as per your two comments, I now only store the `struct type'  of the
function and the return value,
and cache the `gdb.Value' object when GDB stops at a FinishBreakpoint.

`FinishBreakpoint.return_value' may have to populate the cache when
it's accessed from Breakpoint.stop() because there is no guarantee the
FinishBreakpoint observer will be notified first.

> Kevin> +static void
> Kevin> +gdbpy_out_of_scope (struct finish_breakpoint_object *bpfinish_obj)
> Kevin> +{
> Kevin> +  breakpoint_object *bp_obj = (breakpoint_object *) bpfinish_obj;
> Kevin> +  PyObject *py_obj = (PyObject *) bp_obj ;
> Kevin> +
> Kevin> +  bpfinish_obj->out_of_scope_notif = 0;
> Kevin> +
> Kevin> +  if (PyObject_HasAttrString (py_obj, outofscope_func))
> Kevin> +    {
> Kevin> +      struct gdbarch *garch =  bp_obj->bp->gdbarch ?
> Kevin> +          bp_obj->bp->gdbarch : get_current_arch ();
> Kevin> +      struct cleanup *cleanup = ensure_python_env (garch, current_language);
>
> You can't call any Python functions without the GIL.
> This applies to PyObject_HasAttrString here.
>
> In this case, though, gdbpy_out_of_scope is called by one function that
> already has the GIL.  So, I think the acquisition should be pushed into
> its other caller.

fixed

> Kevin> +  pc = get_frame_pc (prev_frame);
>
> This can throw an exception.  So, it needs to be wrapped in a TRY_CATCH.
> This may apply to some other GDB functions called by the "Python-facing"
> code, I did not check them all.

fixed

> Kevin> diff --git a/gdb/testsuite/gdb.python/py-finish-breakpoint-cc.exp b/gdb/testsuite/gdb.python/py-finish-breakpoint-cc.exp
>
> Funny file name.

funny but correct, or too funny? ;)

> Kevin> +gdb_test "python ExceptionBreakpoint()" "ExceptionBreakpoint init" "set BP before throwing the exception"
> Kevin> +gdb_test "python print len(gdb.breakpoints())" "4" "check number of BPs"
> Kevin> +gdb_test "continue" ".*stopped at ExceptionFinishBreakpoint.*" "check FinishBreakpoint in catch()"
> Kevin> +gdb_test "python print len(gdb.breakpoints())" "4" "check finish BP removal"
>
> I don't think this tests the most important case -- where an exception
> is thrown, invalidating the return breakpoint.
>
> That is, put a breakpoint in throw_exception_1, continue to there, then
> set the breakpoint, then continue again.
>
> I didn't examine the longjmp test but the same idea applies there.
>
> Other cases to consider are -
>
> * inferior exec
> * inferior exit
> * explicit inferior function call
> * "return" command

I'll work on the tests for the next version of the patch ("return"
should already be covered)


--

so, about the `out_of_scope' stuffs,

> Kevin> +/* Python function to set the 'out_of_scope_notif' attribute of
> Kevin> +   FinishBreakpoint.  */
> Kevin> +
> Kevin> +static int
> Kevin> +bpfinishpy_set_outofscope_notif (PyObject *self, PyObject *newvalue,
> Kevin> +                                 void *closure)
>
> I don't understand the point of this function.
>
> I think documentation would help.

here is a bit of documentation about this class:

@subsubsection Finish Breakpoints

@cindex python finish breakpoints
@tindex gdb.FinishBreakpoint

A @fdb{finish breakpoint} is a breakpoint set at the return address of
a frame, based on the "finish command. @code{gdb.FinishBreakpoint} extends
@code{gdb.Breakpoint}

@defmethod FinishBreakpoint __init__ frame @r{[}internal@r{]}
Create a FinishBreakpoint at the return of the @code{gdb.Frame} object
@var{frame}. The optional @var{internal} argument allows the breakpoint
to become invisible to the user. @xref{Breakpoints In Python}, for further
details about this argument.
@end defmethod

@defop Operation {gdb.Breakpoint} out_of_scope (self)
In some circonstances (eg, @code{longjmp}, C++ exceptions, @value{GDBN}
@code{return} command, ...), a function may not properly terminate, and thus
never hit a @{code} FinishBreakpoint. When @value{GDBN} notices such a
situation, the @code{out_of_scope} function will be triggered.

This method will only be called if the @code{out_of_scope_notif} attribute
is @code{True}.

Deleting (@code{gdb.Breakpoint.delete()}) the @code{FinishBreakpoint} is
allowed in this function.

You may want to sub-class the @code{gdb.FinishBreakpoint} and implement the
@code{out_of_scope} method:

@smallexample
class MyFinishBreakpoint (gdb.FinishBreakpoint)
	def stop (self):
		print "normal finish"
		return True
	
	def out_of_scope():
		print "abnormal finish"
@end smallexample
@end defop

@defmethod FinishBreakpoint check_scope
Because @value{GDBN} currently only checks if @code{FinishBreakpoint}s ran
out of scope at normal stops, this method allows to force the verification
and trigger the @code{out_of_scope} method if necessary. It will return
@code{True} if @code{out_of_scope()} was triggered, @code{False} otherwise.
@end defmethod


@defivar FinishBreakpoint out_of_scope_notif
This attribute will be @code{True} until the @code{out_of_scope} method has
been called and @code{False} afterwards. This attribute is writeable, so out
of scope notifications can be re-enabled.
@end defivar

@defivar FinishBreakpoint return_value
When @value{GDBN} is stopped at a @code{FinishBreakpoint}, and the frame
used to build the @code{FinishBreakpoint} had debug symbols, this attribute
will contain a @code{gdb.Value} object corresponding to the return value of
the function. The value will be @code{None} if the value was not computable.
This attribute is not writable.
@end defivar


> Kevin> +static PyMethodDef finish_breakpoint_object_methods[] = {
> Kevin> +  { "check_scope", bpfinishpy_check_scope, METH_NOARGS,
> Kevin> +    "check_scope () -> Boolean.\n\
> Kevin> +Return true if out_of_scope() has been triggered, false if not." },
>
> How is this useful?
> And, why a method instead of an attribute?

as described, this is useful especially in the case of a GDB-forced
"return": normal_stop observers are not notified, so `out_of_scope()'
is not triggered. `check_scope()' allows Python scripts to force this
verification when they need. The reason why it's a method is that it
may execute `out_of_scope()', which was, from my point of view,
inconsistent with the concept of attribute.

> Kevin> +static PyGetSetDef finish_breakpoint_object_getset[] = {
> Kevin> +  { "out_of_scope_notif", bpfinishpy_get_outofscope_notif, bpfinishpy_set_outofscope_notif,
>
> I don't like the name "out_of_scope_notif", particularly if this is an
> apt description of its meaning:
> Kevin> +    "Boolean telling whether the breakpoint is still within the scope \
> Kevin> +of the current callstack.", NULL },

I've got some difficulties to find a correct name for this attribute,
which is used for two purposes:
- avoid calling `out_of_scope' every normal_stop when the breakpoint
is not anymore in the callstack
- allow the script to re-activate notification when it wants to
're-use' the FinishBreakpoint (instead of deleting it / creating a new
one)


cordially,

Kevin

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diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 5bab360..2507938 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -285,6 +285,7 @@ SUBDIR_PYTHON_OBS = \
 	py-evtregistry.o \
 	py-evts.o \
 	py-exitedevent.o \
+	py-finishbreakpoint.o \
 	py-frame.o \
 	py-function.o \
 	py-inferior.o \
@@ -315,6 +316,7 @@ SUBDIR_PYTHON_SRCS = \
 	python/py-evtregistry.c \
 	python/py-evts.c \
 	python/py-exitedevent.c \
+	python/py-finishbreakpoint.c \
 	python/py-frame.c \
 	python/py-function.c \
 	python/py-inferior.c \
@@ -2062,6 +2064,10 @@ py-exitedevent.o: $(srcdir)/python/py-exitedevent.c
 	$(COMPILE) $(PYTHON_CFLAGS) $(srcdir)/python/py-exitedevent.c
 	$(POSTCOMPILE)
 
+py-finishbreakpoint.o: $(srcdir)/python/py-finishbreakpoint.c
+	$(COMPILE) $(PYTHON_CFLAGS) $(srcdir)/python/py-finishbreakpoint.c
+	$(POSTCOMPILE)
+
 py-frame.o: $(srcdir)/python/py-frame.c
 	$(COMPILE) $(PYTHON_CFLAGS) $(srcdir)/python/py-frame.c
 	$(POSTCOMPILE)
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 7093104..c1c4f06 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -5814,6 +5814,7 @@ set_raw_breakpoint_without_location (struct gdbarch *gdbarch,
   b->ops = NULL;
   b->condition_not_parsed = 0;
   b->py_bp_object = NULL;
+  b->py_bp_type = py_bp_none;
   b->related_breakpoint = b;
 
   /* Add this breakpoint to the end of the chain so that a list of
diff --git a/gdb/breakpoint.h b/gdb/breakpoint.h
index 7fa705f..a1575a5 100644
--- a/gdb/breakpoint.h
+++ b/gdb/breakpoint.h
@@ -164,6 +164,15 @@ enum bptype
     bp_gnu_ifunc_resolver_return,
   };
 
+/* Type of the Python object associated with a breakpoint.  */
+
+enum py_bp_type
+  {
+    py_bp_none,         /* No Python object.  */
+    py_bp_standard,     /* Ordinary breakpoint object.  */
+    py_bp_finish        /* FinishBreakpoint object.  */
+  };
+
 /* States of enablement of breakpoint.  */
 
 enum enable_state
@@ -654,6 +663,9 @@ struct breakpoint
        types are tracked by the Python scripting API.  */
     struct breakpoint_object *py_bp_object;
 
+    /* Type of the Python Breakpoint object stored in `py_bp_object'.  */
+    enum py_bp_type py_bp_type;
+
     /* Whether this watchpoint is exact (see target_exact_watchpoints).  */
     int exact;
 
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 584a520..27738b4 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -23513,6 +23513,70 @@ commands, separated by newlines.  If there are no commands, this
 attribute is @code{None}.  This attribute is not writable.
 @end defivar
 
+@subsubsection Finish Breakpoints
+
+@cindex python finish breakpoints
+@tindex gdb.FinishBreakpoint
+
+A @fdb{finish breakpoint} is a breakpoint set at the return address of
+a frame, based on the "finish command. @code{gdb.FinishBreakpoint} extends
+@code{gdb.Breakpoint}
+
+@defmethod FinishBreakpoint __init__ frame @r{[}internal@r{]}
+Create a FinishBreakpoint at the return of the @code{gdb.Frame} object 
+@var{frame}. The optional @var{internal} argument allows the breakpoint
+to become invisible to the user. @xref{Breakpoints In Python}, for further 
+details about this argument.
+@end defmethod
+
+@defop Operation {gdb.Breakpoint} out_of_scope (self)
+In some circonstances (eg, @code{longjmp}, C++ exceptions, @value{GDBN} 
+@code{return} command, ...), a function may not properly terminate, and thus 
+never hit a @{code} FinishBreakpoint. When @value{GDBN} notices such a 
+situation, the @code{out_of_scope} function will be triggered.
+
+This method will only be called if the @code{out_of_scope_notif} attribute 
+is @code{True}.
+
+Deleting (@code{gdb.Breakpoint.delete ()}) the @code{FinishBreakpoint} is
+allowed in this function.
+
+You may want to sub-class the @code{gdb.FinishBreakpoint} and implement the
+@code{out_of_scope} method:
+
+@smallexample
+class MyFinishBreakpoint (gdb.FinishBreakpoint)
+	def stop (self):
+		print "normal finish"
+		return True
+	
+	def out_of_scope ():
+		print "abnormal finish"
+@end smallexample 
+@end defop
+
+@defmethod FinishBreakpoint check_scope
+Because @value{GDBN} currently only checks if @code{FinishBreakpoint}s ran
+out of scope at normal stops, this method allows to force the verification
+and trigger the @code{out_of_scope} method if necessary. It will return 
+@code{True} if @code{out_of_scope ()} was triggered, @code{False} otherwise.
+@end defmethod
+
+
+@defivar FinishBreakpoint out_of_scope_notif
+This attribute will be @code{True} until the @code{out_of_scope} method has
+been called and @code{False} afterwards. This attribute is writeable, so out
+of scope notifications can be re-enabled.
+@end defivar
+
+@defivar FinishBreakpoint return_value
+When @value{GDBN} is stopped at a @code{FinishBreakpoint}, and the frame 
+used to build the @code{FinishBreakpoint} had debug symbols, this attribute
+will contain a @code{gdb.Value} object corresponding to the return value of
+the function. The value will be @code{None} if the value was not computable.
+This attribute is not writable.
+@end defivar
+
 @node Lazy Strings In Python
 @subsubsection Python representation of lazy strings.
 
@@ -35239,7 +35303,7 @@ is stopped at the user's request.
 
 @node List of Supported Calls
 @subsection List of Supported Calls
-@cindex list of supported file-i/o calls
+@cindex list of supported fFinile-i/o calls
 
 @menu
 * open::
diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index be1f0a5..2d19ea9 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -1378,14 +1378,12 @@ advance_command (char *arg, int from_tty)
   until_break_command (arg, from_tty, 1);
 }
 \f
-/* Print the result of a function at the end of a 'finish' command.  */
+/* Returns the value of the result at the end of a 'finish' command/BP.  */
 
-static void
-print_return_value (struct type *func_type, struct type *value_type)
+struct value *
+get_return_value (struct type *func_type, struct type *value_type)
 {
   struct gdbarch *gdbarch = get_regcache_arch (stop_registers);
-  struct cleanup *old_chain;
-  struct ui_stream *stb;
   struct value *value;
 
   CHECK_TYPEDEF (value_type);
@@ -1415,6 +1413,18 @@ print_return_value (struct type *func_type, struct type *value_type)
       internal_error (__FILE__, __LINE__, _("bad switch"));
     }
 
+  return value;
+}
+
+/* Print the result of a function at the end of a 'finish' command.  */
+
+static void
+print_return_value (struct type *func_type, struct type *value_type)
+{
+  struct value *value = get_return_value (func_type, value_type);
+  struct cleanup *old_chain;
+  struct ui_stream *stb;
+
   if (value)
     {
       struct value_print_options opts;
diff --git a/gdb/inferior.h b/gdb/inferior.h
index 15e3ca2..e38ce54 100644
--- a/gdb/inferior.h
+++ b/gdb/inferior.h
@@ -285,6 +285,9 @@ extern void detach_command (char *, int);
 
 extern void notice_new_inferior (ptid_t, int, int);
 
+extern struct value *get_return_value (struct type *func_type,
+                                       struct type *value_type);
+
 /* Address at which inferior stopped.  */
 
 extern CORE_ADDR stop_pc;
diff --git a/gdb/infrun.c b/gdb/infrun.c
index 8d6910d..c90a5df 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -54,6 +54,7 @@
 #include "inline-frame.h"
 #include "jit.h"
 #include "tracepoint.h"
+#include "python/python.h"
 
 /* Prototypes for local functions */
 
@@ -336,7 +337,8 @@ show_stop_on_solib_events (struct ui_file *file, int from_tty,
 int stop_after_trap;
 
 /* Save register contents here when executing a "finish" command or are
-   about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set.
+   about to pop a stack dummy frame, if-and-only-if proceed_to_finish is set
+   or a Python FinishBreakpoint have been hit.
    Thus this contains the return value from the called function (assuming
    values are returned in a register).  */
 
@@ -5823,7 +5825,9 @@ normal_stop (void)
 
   /* Save the function value return registers, if we care.
      We might be about to restore their previous contents.  */
-  if (inferior_thread ()->control.proceed_to_finish)
+  if (gdbpy_is_stopped_at_bp_type (inferior_thread ()->control.stop_bpstat,
+                                   py_bp_finish)
+      || inferior_thread ()->control.proceed_to_finish)
     {
       /* This should not be necessary.  */
       if (stop_registers)
diff --git a/gdb/python/py-breakpoint.c b/gdb/python/py-breakpoint.c
index 9c33848..07247d8 100644
--- a/gdb/python/py-breakpoint.c
+++ b/gdb/python/py-breakpoint.c
@@ -31,52 +31,18 @@
 #include "arch-utils.h"
 #include "language.h"
 
-static PyTypeObject breakpoint_object_type;
+PyTypeObject breakpoint_object_type;
 
 /* Number of live breakpoints.  */
 static int bppy_live;
 
 /* Variables used to pass information between the Breakpoint
    constructor and the breakpoint-created hook function.  */
-static breakpoint_object *bppy_pending_object;
+breakpoint_object *bppy_pending_object;
 
 /* Function that is called when a Python condition is evaluated.  */
 static char * const stop_func = "stop";
 
-struct breakpoint_object
-{
-  PyObject_HEAD
-
-  /* The breakpoint number according to gdb.  */
-  int number;
-
-  /* The gdb breakpoint object, or NULL if the breakpoint has been
-     deleted.  */
-  struct breakpoint *bp;
-};
-
-/* Require that BREAKPOINT be a valid breakpoint ID; throw a Python
-   exception if it is invalid.  */
-#define BPPY_REQUIRE_VALID(Breakpoint)					\
-    do {								\
-      if ((Breakpoint)->bp == NULL)					\
-	return PyErr_Format (PyExc_RuntimeError,                        \
-			     _("Breakpoint %d is invalid."),		\
-			     (Breakpoint)->number);			\
-    } while (0)
-
-/* Require that BREAKPOINT be a valid breakpoint ID; throw a Python
-   exception if it is invalid.  This macro is for use in setter functions.  */
-#define BPPY_SET_REQUIRE_VALID(Breakpoint)				\
-    do {								\
-      if ((Breakpoint)->bp == NULL)					\
-        {								\
-	  PyErr_Format (PyExc_RuntimeError, _("Breakpoint %d is invalid."), \
-			(Breakpoint)->number);				\
-	  return -1;							\
-	}								\
-    } while (0)
-
 /* This is used to initialize various gdb.bp_* constants.  */
 struct pybp_code
 {
@@ -753,6 +719,23 @@ gdbpy_should_stop (struct breakpoint_object *bp_obj)
   return stop;
 }
 
+/* If STOP_BPSTAT contains a Python breakpoint whose type is TYPE, returns
+   this breakpoint. Returns NULL otherwise.  */
+
+struct breakpoint *
+gdbpy_is_stopped_at_bp_type (bpstat stop_bpstat, enum py_bp_type type)
+{
+  bpstat bs;
+
+  for (bs = stop_bpstat; bs; bs = bs->next)
+    {
+      if (bs->breakpoint_at && bs->breakpoint_at->py_bp_type == type)
+        return bs->breakpoint_at;
+    }
+
+  return NULL;
+}
+
 /* Checks if the  "stop" method exists in this breakpoint.
    Used by condition_command to ensure mutual exclusion of breakpoint
    conditions.  */
@@ -813,6 +796,11 @@ gdbpy_breakpoint_created (struct breakpoint *bp)
       newbp->bp->py_bp_object = newbp;
       Py_INCREF (newbp);
       ++bppy_live;
+
+      if (bpfinishpy_is_finish_bp ((PyObject *) newbp))
+        bp->py_bp_type = py_bp_finish;
+      else
+        bp->py_bp_type = py_bp_standard;
     }
   else
     {
@@ -971,7 +959,7 @@ static PyMethodDef breakpoint_object_methods[] =
   { NULL } /* Sentinel.  */
 };
 
-static PyTypeObject breakpoint_object_type =
+PyTypeObject breakpoint_object_type =
 {
   PyObject_HEAD_INIT (NULL)
   0,				  /*ob_size*/
diff --git a/gdb/python/py-finishbreakpoint.c b/gdb/python/py-finishbreakpoint.c
new file mode 100644
index 0000000..26918cc
--- /dev/null
+++ b/gdb/python/py-finishbreakpoint.c
@@ -0,0 +1,478 @@
+/* Python interface to finish breakpoints
+
+   Copyright (C) 2011 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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/>.  */
+
+
+
+#include "defs.h"
+#include "exceptions.h"
+#include "python-internal.h"
+#include "breakpoint.h"
+#include "frame.h"
+#include "gdbthread.h"
+#include "arch-utils.h"
+#include "language.h"
+#include "observer.h"
+#include "inferior.h"
+
+static PyTypeObject finish_breakpoint_object_type;
+
+/* Function that is called when a Python finish bp is found out of scope.  */
+static char * const outofscope_func = "out_of_scope";
+
+/* struct implementing the gdb.FinishBreakpoint object by extending
+   the gdb.Breakpoint class.  */
+struct finish_breakpoint_object
+{
+  /* gdb.Breakpoint base class.  */
+  struct breakpoint_object py_bp;
+  /* Flag indicating that the BP is out of the callstack and Python callback
+     has been triggered.  */
+  int out_of_scope_notif;
+  /* Type of the function finished by this breakpoint.  */
+  struct type *function_type;
+  /* Type of the value return by the breakpointed function.  */
+  struct type *return_type;
+  /* When stopped at this FinishBreakpoint, value returned by the function;
+     Py_None if the value is not computable;
+     NULL if GDB is not stopped at a FinishBreakpoint.  */
+  PyObject *return_value;
+};
+
+/* Python function to set the 'out_of_scope_notif' attribute of
+   FinishBreakpoint.  */
+
+static int
+bpfinishpy_set_outofscope_notif (PyObject *self, PyObject *newvalue,
+                                 void *closure)
+{
+  struct finish_breakpoint_object *self_finishbp =
+      (struct finish_breakpoint_object *) self;
+  int cmp;
+
+  BPPY_SET_REQUIRE_VALID (&self_finishbp->py_bp);
+
+  if (newvalue == NULL)
+    {
+      PyErr_SetString (PyExc_TypeError,
+                           _("Cannot delete `out_of_scope_notif' attribute."));
+      return -1;
+    }
+  else if (!PyBool_Check (newvalue))
+    {
+      PyErr_SetString (PyExc_TypeError,
+                    _("The value of `out_of_scope_notif' must be a boolean."));
+      return -1;
+    }
+
+  cmp = PyObject_IsTrue (newvalue);
+  if (cmp < 0)
+    return -1;
+  else
+    self_finishbp->out_of_scope_notif = cmp;
+
+  return 0;
+}
+
+/* Python function to update and get the 'out_of_scope_notif'
+   attribute of FinishBreakpoint.  */
+
+static PyObject *
+bpfinishpy_get_outofscope_notif (PyObject *self, void *closure)
+{
+  struct finish_breakpoint_object *self_finishbp =
+      (struct finish_breakpoint_object *) self;
+
+  BPPY_REQUIRE_VALID (&self_finishbp->py_bp);
+
+  if (self_finishbp->out_of_scope_notif)
+    Py_RETURN_TRUE;
+  Py_RETURN_FALSE;
+}
+
+/* Triggered when GDB stops at PY_BP. Disable `out_of_scope' notifications
+   and, if possible, computes and caches the `return_value'.  */
+
+static void
+bpfinish_stopped_at_finish_bp (struct finish_breakpoint_object *py_bp)
+{
+  py_bp->out_of_scope_notif = 0;
+
+  if (py_bp->return_type)
+    {
+      struct value *ret = get_return_value (py_bp->function_type,
+                                            py_bp->return_type);
+      if (ret)
+        {
+          py_bp->return_value = value_to_value_object (ret);
+        }
+      else
+        py_bp->return_value = Py_None;
+    }
+}
+
+/* Python function to get the 'return_value' attribute of
+   FinishBreakpoint.  */
+
+static PyObject *
+bpfinishpy_get_returnvalue (PyObject *self, void *closure)
+{
+  struct finish_breakpoint_object *self_finishbp =
+      (struct finish_breakpoint_object *) self;
+
+  BPPY_REQUIRE_VALID (&self_finishbp->py_bp);
+
+  if (self_finishbp->return_type == NULL)
+    Py_RETURN_NONE;
+
+  /* Check if we have a cached value.  */
+  if (!self_finishbp->return_value)
+    {
+      bpstat bs;
+
+      for (bs = inferior_thread ()->control.stop_bpstat;
+          bs; bs = bs->next)
+        {
+          struct breakpoint *bp = bs->breakpoint_at;
+
+          if (bp != NULL && (PyObject *) bp->py_bp_object == self)
+              bpfinish_stopped_at_finish_bp (self_finishbp);
+        }
+    }
+
+  if (!self_finishbp->return_value)
+    Py_RETURN_NONE;
+
+  Py_INCREF (self_finishbp->return_value);
+  return self_finishbp->return_value;
+}
+
+/* Called when GDB notices that the finish breakpoint BP_OBJ is out of 
+   the current callstack. If BP_OBJ has the attribute OUT_OF_SCOPE_NOTIF
+   and its value is FALSE, trigger the method OUT_OF_SCOPE and set the flag
+   to TRUE.  */
+
+static void
+gdbpy_out_of_scope (struct finish_breakpoint_object *bpfinish_obj)
+{
+  breakpoint_object *bp_obj = (breakpoint_object *) bpfinish_obj;
+  PyObject *py_obj = (PyObject *) bp_obj;
+  
+  bpfinish_obj->out_of_scope_notif = 0;
+
+  if (PyObject_HasAttrString (py_obj, outofscope_func))
+    {
+      if (!PyObject_CallMethod (py_obj, outofscope_func, NULL))
+          gdbpy_print_stack ();
+    }
+}
+
+/* Python function to check if the FinishBreakpoint SELF is not anymore
+   in the callstack. Triggers self->out_of_scope if necessary.  */
+
+static PyObject *
+bpfinishpy_check_scope (PyObject *self, PyObject *args)
+{
+  struct finish_breakpoint_object *self_finishbp =
+      (struct finish_breakpoint_object *) self;
+
+  if (self_finishbp->out_of_scope_notif
+      && frame_find_by_id (self_finishbp->py_bp.bp->frame_id) == NULL)
+    {
+      gdbpy_out_of_scope (self_finishbp);
+
+      Py_RETURN_TRUE;
+    }
+  Py_RETURN_FALSE;
+}
+
+/* Python function to create a new breakpoint.  */
+
+static int
+bpfinishpy_init (PyObject *self, PyObject *args, PyObject *kwargs)
+{
+  static char *keywords[] = { "frame", "internal", NULL };
+  breakpoint_object *self_bp = (breakpoint_object *) self;
+  struct finish_breakpoint_object *self_bpfinish =
+      (struct finish_breakpoint_object *) self;
+  int type = bp_breakpoint;
+  PyObject *frame_obj = NULL;
+  struct frame_info *frame, *prev_frame;
+  struct frame_id frame_id;
+  PyObject *internal = NULL;
+  int internal_bp = 0;
+  CORE_ADDR finish_pc, pc;
+  volatile struct gdb_exception except;
+  char *addr_str, small_buf[100];
+  struct symbol *function;
+
+  if (! PyArg_ParseTupleAndKeywords (args, kwargs, "O|O", keywords,
+                                     &frame_obj, &internal))
+    return -1;
+
+  if (!frame_obj)
+    goto invalid_frame;
+  
+  frame = frame_object_to_frame_info (frame_obj);
+  if (frame == NULL)
+    goto invalid_frame;
+  
+  prev_frame = get_prev_frame (frame);
+  if (prev_frame == 0)
+    {
+      PyErr_SetString (PyExc_ValueError, 
+           _("\"FinishBreakpoint\" not meaningful in the outermost frame."));
+      return -1;
+    }
+  
+  frame_id = get_frame_id (prev_frame);
+  if (frame_id_eq (frame_id, null_frame_id))
+    goto invalid_frame;
+
+  if (internal)
+    {
+      internal_bp = PyObject_IsTrue (internal);
+      if (internal_bp == -1) 
+        {
+          PyErr_SetString (PyExc_ValueError, 
+                           _("The value of `internal' must be a boolean."));
+          return -1;
+        }
+    }
+
+  /* Find the function we will return from.  */
+  if (get_frame_pc_if_available (frame, &pc))
+    {
+      function = find_pc_function (pc);
+      self_bpfinish->return_type = TYPE_TARGET_TYPE (SYMBOL_TYPE (function));
+
+      /* Remember only non-VOID return types.  */
+      if (TYPE_CODE (self_bpfinish->return_type) != TYPE_CODE_VOID)
+        {
+          self_bpfinish->function_type = SYMBOL_TYPE (function);
+        }
+      else
+        self_bpfinish->return_type = NULL;
+    }
+  else
+    {
+      self_bpfinish->return_type = NULL;
+      self_bpfinish->function_type = NULL;
+    }
+
+  bppy_pending_object = self_bp;
+  bppy_pending_object->number = -1;
+  bppy_pending_object->bp = NULL;
+
+  TRY_CATCH (except, RETURN_MASK_ALL)
+    {
+      /* Set a breakpoint on the return address.  */
+      finish_pc = get_frame_pc (prev_frame);
+      sprintf (small_buf, "*%s", hex_string (finish_pc));
+      addr_str = small_buf;
+
+      create_breakpoint (python_gdbarch,
+                         addr_str, NULL, -1,
+                         0,
+                         0, bp_breakpoint,
+                         0,
+                         AUTO_BOOLEAN_TRUE,
+                         NULL, 0, 1, internal_bp);
+    }
+  if (except.reason < 0)
+    {
+      PyErr_Format (except.reason == RETURN_QUIT
+                    ? PyExc_KeyboardInterrupt : PyExc_RuntimeError,
+                    "%s", except.message);
+      return -1;
+    }
+  BPPY_SET_REQUIRE_VALID (self_bp);
+  
+  self_bp->bp->frame_id = frame_id;
+  
+  self_bpfinish->out_of_scope_notif = 1;
+  
+  return 0;
+  
+ invalid_frame:
+  PyErr_SetString (PyExc_ValueError, 
+                   _("Invalid ID for the `frame' object."));
+  return -1;
+}
+
+/* Returns 1 if OBJ is not NULL and references a FinishBreakpoint object.  */
+
+int
+bpfinishpy_is_finish_bp (PyObject *obj)
+{
+  return obj != NULL
+         && PyObject_TypeCheck (obj, &finish_breakpoint_object_type);
+}
+
+/* Callback for `bpfinishpy_detect_out_scope'.  Triggers Python's
+   `B->out_of_scope' function if B is a FinishBreakpoint out of its
+    scope or turn of out_of_scope notification if B has been hit.  */
+
+static int
+bpfinishpy_detect_out_scope_cb (struct breakpoint *b, void *args)
+{
+  struct breakpoint *bp_stopped = (struct breakpoint *) args;
+  PyObject *py_bp = (PyObject *) b->py_bp_object;
+  struct gdbarch *garch = b->gdbarch ? b->gdbarch : get_current_arch ();
+  struct cleanup *cleanup = ensure_python_env (garch, current_language);
+  
+  /* Trigger out_of_scope if this is a FinishBreakpoint its frame is not in the
+     current callstack and the notification has not been sent yet.  */
+  if (bpfinishpy_is_finish_bp (py_bp))
+    {
+      struct finish_breakpoint_object *finish_bp =
+          (struct finish_breakpoint_object *) py_bp;
+
+      if (b == bp_stopped)
+        bpfinish_stopped_at_finish_bp (finish_bp);
+      else if (frame_find_by_id(b->frame_id) == NULL
+           && finish_bp->out_of_scope_notif)
+        {
+          gdbpy_out_of_scope (finish_bp);
+        }
+    }
+  
+  do_cleanups (cleanup);
+  
+  return 0;
+}
+
+/* Attached to `stop' notifications, check if the execution has run out
+   out of the scope of any FinishBreakpoint before it has been hit.  */
+
+static void
+bpfinishpy_handle_stop (struct bpstats *bs, int print_frame)
+{
+  iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb,
+                            bs == NULL ? NULL : bs->breakpoint_at);
+}
+
+/* Attached to `exit' notifications, triggers all the necessary out of
+   scope notifications.  */
+
+static void
+bpfinishpy_handle_exit (struct inferior *inf)
+{
+  iterate_over_breakpoints (bpfinishpy_detect_out_scope_cb, NULL);
+}
+
+/* Callback to the bpfinishpy_handle_resume function.  */
+
+static int
+bpfinishpy_handle_resume_cb (struct breakpoint *b, void *args)
+{
+  if (bpfinishpy_is_finish_bp ((PyObject *) b->py_bp_object))
+    {
+      struct finish_breakpoint_object *finish_bp =
+                      (struct finish_breakpoint_object *) b->py_bp_object;
+      Py_XDECREF (finish_bp->return_value);
+      finish_bp->return_value = NULL;
+    }
+  return 0;
+}
+
+/* Attached to `target_resume' notifications, resets the `return_value'
+   cache.  */
+
+static void
+bpfinishpy_handle_resume (ptid_t ptid)
+{
+  iterate_over_breakpoints (bpfinishpy_handle_resume_cb, NULL);
+}
+
+/* Initialize the Python finish breakpoint code.  */
+
+void
+gdbpy_initialize_finishbreakpoints (void)
+{
+  if (PyType_Ready (&finish_breakpoint_object_type) < 0)
+      return;
+  
+  Py_INCREF (&finish_breakpoint_object_type);
+  PyModule_AddObject (gdb_module, "FinishBreakpoint",
+                      (PyObject *) &finish_breakpoint_object_type);
+    
+  observer_attach_normal_stop (bpfinishpy_handle_stop);
+  observer_attach_inferior_exit (bpfinishpy_handle_exit);
+  observer_attach_target_resumed (bpfinishpy_handle_resume);
+}
+
+static PyMethodDef finish_breakpoint_object_methods[] = {
+  { "check_scope", bpfinishpy_check_scope, METH_NOARGS,
+    "check_scope () -> Boolean.\n\
+Return true if out_of_scope () has been triggered, false if not." },
+  {NULL}  /* Sentinel */
+};
+
+static PyGetSetDef finish_breakpoint_object_getset[] = {
+  { "out_of_scope_notif", bpfinishpy_get_outofscope_notif, bpfinishpy_set_outofscope_notif,
+    "Boolean telling whether the breakpoint is still within the scope \
+of the current callstack.", NULL },
+  { "return_value", bpfinishpy_get_returnvalue, NULL,
+  "gdb.Value object representing the return value, if any. \
+None otherwise.", NULL },
+    { NULL }  /* Sentinel.  */
+};
+
+static PyTypeObject finish_breakpoint_object_type =
+{
+  PyObject_HEAD_INIT (NULL)
+  0,                              /*ob_size*/
+  "gdb.FinishBreakpoint",         /*tp_name*/
+  sizeof (struct finish_breakpoint_object),  /*tp_basicsize*/
+  0,                              /*tp_itemsize*/
+  0,                              /*tp_dealloc*/
+  0,                              /*tp_print*/
+  0,                              /*tp_getattr*/
+  0,                              /*tp_setattr*/
+  0,                              /*tp_compare*/
+  0,                              /*tp_repr*/
+  0,                              /*tp_as_number*/
+  0,                              /*tp_as_sequence*/
+  0,                              /*tp_as_mapping*/
+  0,                              /*tp_hash */
+  0,                              /*tp_call*/
+  0,                              /*tp_str*/
+  0,                              /*tp_getattro*/
+  0,                              /*tp_setattro */
+  0,                              /*tp_as_buffer*/
+  Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
+  "GDB finish breakpoint object", /* tp_doc */
+  0,                              /* tp_traverse */
+  0,                              /* tp_clear */
+  0,                              /* tp_richcompare */
+  0,                              /* tp_weaklistoffset */
+  0,                              /* tp_iter */
+  0,                              /* tp_iternext */
+  finish_breakpoint_object_methods,  /* tp_methods */
+  0,                              /* tp_members */
+  finish_breakpoint_object_getset,/* tp_getset */
+  &breakpoint_object_type,        /* tp_base */
+  0,                              /* tp_dict */
+  0,                              /* tp_descr_get */
+  0,                              /* tp_descr_set */
+  0,                              /* tp_dictoffset */
+  bpfinishpy_init,                /* tp_init */
+  0,                              /* tp_alloc */
+  0                               /* tp_new */
+};
diff --git a/gdb/python/py-frame.c b/gdb/python/py-frame.c
index d7128a9..2109c73 100644
--- a/gdb/python/py-frame.c
+++ b/gdb/python/py-frame.c
@@ -60,9 +60,10 @@ static PyTypeObject frame_object_type;
    object.  If the frame doesn't exist anymore (the frame id doesn't
    correspond to any frame in the inferior), returns NULL.  */
 
-static struct frame_info *
-frame_object_to_frame_info (frame_object *frame_obj)
+struct frame_info *
+frame_object_to_frame_info (PyObject *obj)
 {
+  frame_object *frame_obj = (frame_object *) obj;  
   struct frame_info *frame;
 
   frame = frame_find_by_id (frame_obj->frame_id);
@@ -103,7 +104,7 @@ frapy_is_valid (PyObject *self, PyObject *args)
 {
   struct frame_info *frame;
 
-  frame = frame_object_to_frame_info ((frame_object *) self);
+  frame = frame_object_to_frame_info (self);
   if (frame == NULL)
     Py_RETURN_FALSE;
 
@@ -124,7 +125,7 @@ frapy_name (PyObject *self, PyObject *args)
 
   TRY_CATCH (except, RETURN_MASK_ALL)
     {
-      FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
+      FRAPY_REQUIRE_VALID (self, frame);
 
       find_frame_funname (frame, &name, &lang, NULL);
     }
@@ -153,7 +154,7 @@ frapy_type (PyObject *self, PyObject *args)
 
   TRY_CATCH (except, RETURN_MASK_ALL)
     {
-      FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
+      FRAPY_REQUIRE_VALID (self, frame);
 
       type = get_frame_type (frame);
     }
@@ -174,7 +175,7 @@ frapy_unwind_stop_reason (PyObject *self, PyObject *args)
 
   TRY_CATCH (except, RETURN_MASK_ALL)
     {
-      FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
+      FRAPY_REQUIRE_VALID (self, frame);
     }
   GDB_PY_HANDLE_EXCEPTION (except);
 
@@ -195,7 +196,7 @@ frapy_pc (PyObject *self, PyObject *args)
 
   TRY_CATCH (except, RETURN_MASK_ALL)
     {
-      FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
+      FRAPY_REQUIRE_VALID (self, frame);
 
       pc = get_frame_pc (frame);
     }
@@ -216,7 +217,7 @@ frapy_block (PyObject *self, PyObject *args)
 
   TRY_CATCH (except, RETURN_MASK_ALL)
     {
-      FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
+      FRAPY_REQUIRE_VALID (self, frame);
       block = get_frame_block (frame, NULL);
     }
   GDB_PY_HANDLE_EXCEPTION (except);
@@ -257,7 +258,7 @@ frapy_function (PyObject *self, PyObject *args)
 
   TRY_CATCH (except, RETURN_MASK_ALL)
     {
-      FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
+      FRAPY_REQUIRE_VALID (self, frame);
 
       sym = find_pc_function (get_frame_address_in_block (frame));
     }
@@ -319,7 +320,7 @@ frapy_older (PyObject *self, PyObject *args)
 
   TRY_CATCH (except, RETURN_MASK_ALL)
     {
-      FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
+      FRAPY_REQUIRE_VALID (self, frame);
 
       prev = get_prev_frame (frame);
       if (prev)
@@ -348,7 +349,7 @@ frapy_newer (PyObject *self, PyObject *args)
 
   TRY_CATCH (except, RETURN_MASK_ALL)
     {
-      FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
+      FRAPY_REQUIRE_VALID (self, frame);
 
       next = get_next_frame (frame);
       if (next)
@@ -377,7 +378,7 @@ frapy_find_sal (PyObject *self, PyObject *args)
 
   TRY_CATCH (except, RETURN_MASK_ALL)
     {
-      FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
+      FRAPY_REQUIRE_VALID (self, frame);
 
       find_frame_sal (frame, &sal);
       sal_obj = symtab_and_line_to_sal_object (sal);
@@ -433,7 +434,7 @@ frapy_read_var (PyObject *self, PyObject *args)
 
       TRY_CATCH (except, RETURN_MASK_ALL)
 	{
-	  FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
+	  FRAPY_REQUIRE_VALID (self, frame);
 
 	  if (!block)
 	    block = get_frame_block (frame, NULL);
@@ -461,7 +462,7 @@ frapy_read_var (PyObject *self, PyObject *args)
 
   TRY_CATCH (except, RETURN_MASK_ALL)
     {
-      FRAPY_REQUIRE_VALID ((frame_object *) self, frame);
+      FRAPY_REQUIRE_VALID (self, frame);
 
       val = read_var_value (var, frame);
     }
@@ -484,12 +485,11 @@ static PyObject *
 frapy_select (PyObject *self, PyObject *args)
 {
   struct frame_info *fi;
-  frame_object *frame = (frame_object *) self;
   volatile struct gdb_exception except;
 
   TRY_CATCH (except, RETURN_MASK_ALL)
     {
-      FRAPY_REQUIRE_VALID (frame, fi);
+      FRAPY_REQUIRE_VALID (self, fi);
 
       select_frame (fi);
     }
diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index d3cb788..e404a32 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -114,9 +114,47 @@ extern PyTypeObject symbol_object_type;
 extern PyTypeObject event_object_type;
 extern PyTypeObject events_object_type;
 extern PyTypeObject stop_event_object_type;
+extern PyTypeObject breakpoint_object_type;
+
+typedef struct breakpoint_object
+{
+  PyObject_HEAD
+
+  /* The breakpoint number according to gdb.  */
+  int number;
+
+  /* The gdb breakpoint object, or NULL if the breakpoint has been
+     deleted.  */
+  struct breakpoint *bp;
+} breakpoint_object;
+
+/* Require that BREAKPOINT be a valid breakpoint ID; throw a Python
+   exception if it is invalid.  */
+#define BPPY_REQUIRE_VALID(Breakpoint)                                  \
+    do {                                                                \
+      if ((Breakpoint)->bp == NULL)                                     \
+        return PyErr_Format (PyExc_RuntimeError,                        \
+                             _("Breakpoint %d is invalid."),            \
+                             (Breakpoint)->number);                     \
+    } while (0)
+
+/* Require that BREAKPOINT be a valid breakpoint ID; throw a Python
+   exception if it is invalid.  This macro is for use in setter functions.  */
+#define BPPY_SET_REQUIRE_VALID(Breakpoint)                              \
+    do {                                                                \
+      if ((Breakpoint)->bp == NULL)                                     \
+        {                                                               \
+          PyErr_Format (PyExc_RuntimeError, _("Breakpoint %d is invalid."), \
+                        (Breakpoint)->number);                          \
+          return -1;                                                    \
+        }                                                               \
+    } while (0)
+
+
+/* Variables used to pass information between the Breakpoint
+   constructor and the breakpoint-created hook function.  */
+extern breakpoint_object *bppy_pending_object;
 
-/* Defined in py-breakpoint.c */
-typedef struct breakpoint_object breakpoint_object;
 
 typedef struct
 {
@@ -161,6 +199,7 @@ PyObject *block_to_block_object (struct block *block, struct objfile *objfile);
 PyObject *value_to_value_object (struct value *v);
 PyObject *type_to_type_object (struct type *);
 PyObject *frame_info_to_frame_object (struct frame_info *frame);
+struct frame_info *frame_object_to_frame_info (PyObject *frame_obj);
 
 PyObject *pspace_to_pspace_object (struct program_space *);
 PyObject *pspy_get_printers (PyObject *, void *);
@@ -181,6 +220,8 @@ struct type *type_object_to_type (PyObject *obj);
 struct symtab *symtab_object_to_symtab (PyObject *obj);
 struct symtab_and_line *sal_object_to_symtab_and_line (PyObject *obj);
 
+int bpfinishpy_is_finish_bp (PyObject *obj);
+
 void gdbpy_initialize_auto_load (void);
 void gdbpy_initialize_values (void);
 void gdbpy_initialize_frames (void);
@@ -194,6 +235,7 @@ void gdbpy_initialize_functions (void);
 void gdbpy_initialize_pspace (void);
 void gdbpy_initialize_objfile (void);
 void gdbpy_initialize_breakpoints (void);
+void gdbpy_initialize_finishbreakpoints (void);
 void gdbpy_initialize_lazy_string (void);
 void gdbpy_initialize_parameters (void);
 void gdbpy_initialize_thread (void);
diff --git a/gdb/python/python.c b/gdb/python/python.c
index 8a7bc66..f71fd4a 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -926,6 +926,11 @@ gdbpy_breakpoint_has_py_cond (struct breakpoint_object *bp_obj)
 		    "scripting is not supported."));
 }
 
+struct breakpoint *
+gdbpy_is_stopped_at_bp_type (bpstat stop_bpstat, enum py_bp_type type)
+{
+  return NULL;
+}
 #endif /* HAVE_PYTHON */
 
 \f
@@ -1060,6 +1065,7 @@ Enables or disables printing of Python stack traces."),
   gdbpy_initialize_pspace ();
   gdbpy_initialize_objfile ();
   gdbpy_initialize_breakpoints ();
+  gdbpy_initialize_finishbreakpoints ();
   gdbpy_initialize_lazy_string ();
   gdbpy_initialize_thread ();
   gdbpy_initialize_inferior ();
diff --git a/gdb/python/python.h b/gdb/python/python.h
index ce0eb35..9be6ac9 100644
--- a/gdb/python/python.h
+++ b/gdb/python/python.h
@@ -21,6 +21,7 @@
 #define GDB_PYTHON_H
 
 #include "value.h"
+#include "breakpoint.h"
 
 struct breakpoint_object;
 
@@ -47,4 +48,6 @@ int gdbpy_should_stop (struct breakpoint_object *bp_obj);
 
 int gdbpy_breakpoint_has_py_cond (struct breakpoint_object *bp_obj);
 
+struct breakpoint *gdbpy_is_stopped_at_bp_type (bpstat stop_bpstat,
+                                                enum py_bp_type type);
 #endif /* GDB_PYTHON_H */
diff --git a/gdb/testsuite/gdb.python/py-breakpoint.exp b/gdb/testsuite/gdb.python/py-breakpoint.exp
index f0a83f1..8755888 100644
--- a/gdb/testsuite/gdb.python/py-breakpoint.exp
+++ b/gdb/testsuite/gdb.python/py-breakpoint.exp
@@ -44,7 +44,8 @@ gdb_py_test_silent_cmd "python blist = gdb.breakpoints()" "Get Breakpoint List"
 gdb_test "python print blist\[0\]" "<gdb.Breakpoint object at $hex>" "Check obj exists"
 gdb_test "python print blist\[0\].location" "main." "Check breakpoint location"
 
-gdb_breakpoint [gdb_get_line_number "Break at multiply."]
+set mult_line [gdb_get_line_number "Break at multiply."]
+gdb_breakpoint ${mult_line}
 gdb_continue_to_breakpoint "Break at multiply."
 
 # Check that the Python breakpoint code noted the addition of a
@@ -54,7 +55,9 @@ gdb_test "python print len(blist)" "2" "Check for two breakpoints"
 gdb_test "python print blist\[0\]" "<gdb.Breakpoint object at $hex>" "Check obj exists"
 gdb_test "python print blist\[0\].location" "main." "Check breakpoint location"
 gdb_test "python print blist\[1\]" "<gdb.Breakpoint object at $hex>" "Check obj exists"
-gdb_test "python print blist\[1\].location" "py-breakpoint\.c:41*" "Check breakpoint location"
+
+gdb_test "python print blist\[1\].location" "py-breakpoint\.c:${mult_line}*" \
+         "Check breakpoint location"
 
 # Check hit and ignore counts. 
 gdb_test "python print blist\[1\].hit_count" "1" "Check breakpoint hit count"
diff --git a/gdb/testsuite/gdb.python/py-finish-breakpoint-cc.cc b/gdb/testsuite/gdb.python/py-finish-breakpoint-cc.cc
new file mode 100644
index 0000000..a0eea06
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-finish-breakpoint-cc.cc
@@ -0,0 +1,59 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2011 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/>.
+*/
+
+
+#include <iostream>
+
+void
+throw_exception_1 (int e)
+{
+  throw new int (e);
+}
+
+void
+throw_exception (int e)
+{
+  throw_exception_1 (e);
+}
+
+int
+main (void)
+{
+  int i;
+  try
+    {
+      throw_exception_1 (10);
+    }
+  catch (const int *e)
+    {
+        std::cerr << "Exception #" << *e << std::endl;
+    }
+  i += 1; /* Break after exception 1.  */
+
+  try
+    {
+      throw_exception (10);
+    }
+  catch (const int *e)
+    {
+        std::cerr << "Exception #" << *e << std::endl;
+    }
+  i += 1; /* Break after exception 2.  */
+
+  return i;
+}
diff --git a/gdb/testsuite/gdb.python/py-finish-breakpoint-cc.exp b/gdb/testsuite/gdb.python/py-finish-breakpoint-cc.exp
new file mode 100644
index 0000000..e74023d
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-finish-breakpoint-cc.exp
@@ -0,0 +1,59 @@
+# Copyright (C) 2011 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/>.
+
+# This file is part of the GDB testsuite.  It tests the mechanism
+# exposing values to Python.
+
+if $tracelevel then {
+    strace $tracelevel
+}
+
+load_lib gdb-python.exp
+
+set testfile "py-finish-breakpoint-cc"
+set srcfile ${testfile}.cc
+set binfile ${objdir}/${subdir}/${testfile}
+set pyfile  ${srcdir}/${subdir}/${testfile}.py
+
+# Start with a fresh gdb.
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug c++}] != "" } {
+    untested "Couldn't compile ${srcfile}"
+    return -1
+}
+
+if ![runto_main] then {
+    fail "Cannot run to main."
+    return 0
+}
+
+gdb_test "source $pyfile" ".*Python script imported.*" \
+         "import python scripts"
+
+gdb_test "break [gdb_get_line_number "Break after exception 1."]" "Breakpoint.* at .*" \
+         "set watchdog after the exception 1"
+gdb_test "break [gdb_get_line_number "Break after exception 2."]" "Breakpoint.* at .*" \
+         "set watchdog after the exception 2"
+         
+gdb_test "python ExceptionBreakpoint()" "ExceptionBreakpoint init" "set BP before throwing the exception"
+gdb_test "python print len(gdb.breakpoints())" "4" "check number of BPs"
+gdb_test "continue" ".*stopped at ExceptionFinishBreakpoint.*" "check FinishBreakpoint in catch()"
+gdb_test "python print len(gdb.breakpoints())" "4" "check finish BP removal"
+
+gdb_test "continue" ".*exception did not finish.*" "FinishBreakpoint with exception thrown not caught"
diff --git a/gdb/testsuite/gdb.python/py-finish-breakpoint-cc.py b/gdb/testsuite/gdb.python/py-finish-breakpoint-cc.py
new file mode 100644
index 0000000..d0dfe2f
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-finish-breakpoint-cc.py
@@ -0,0 +1,43 @@
+# Copyright (C) 2011 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/>.
+
+# This file is part of the GDB testsuite.  It tests python Finish
+# Breakpoints.
+
+class ExceptionBreakpoint(gdb.Breakpoint):
+    def __init__(self):
+        gdb.Breakpoint.__init__(self, spec="throw_exception_1", internal=1)
+        self.silent = True
+        print "ExceptionBreakpoint init"
+        
+    def stop(self):
+        ExceptionFinishBreakpoint(gdb.newest_frame())
+        return False
+
+class ExceptionFinishBreakpoint(gdb.FinishBreakpoint):
+    def __init__(self, frame):
+        gdb.FinishBreakpoint.__init__(self, frame, internal=1)
+        self.silent = True;
+ 
+    def stop(self):
+	print "stopped at ExceptionFinishBreakpoint"
+	gdb.post_event(self.delete)
+        return True 
+    
+    def out_of_scope(self):
+        print "exception did not finish ..."
+
+
+print "Python script imported"
diff --git a/gdb/testsuite/gdb.python/py-finish-breakpoint.c b/gdb/testsuite/gdb.python/py-finish-breakpoint.c
new file mode 100644
index 0000000..57a6e06
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-finish-breakpoint.c
@@ -0,0 +1,82 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2011 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/>.
+*/
+#include <setjmp.h>
+
+int increase_1 (int *a)
+{
+  *a += 1;
+  return -5;
+}
+
+void increase (int *a)
+{
+  increase_1 (a);
+}
+
+int
+test_1 (int i, int j)
+{
+  return i == j;
+}
+
+int
+test(int i, int j)
+{
+  return test_1 (i, j);
+}
+
+int
+call_longjmp_1 (jmp_buf *buf)
+{
+  longjmp (*buf, 1);
+}
+
+int
+call_longjmp (jmp_buf *buf)
+{
+  call_longjmp_1 (buf);
+}
+
+
+int main (int argc, char *argv[])
+{
+  jmp_buf env;
+  int foo = 5;
+  int bar = 42;
+  int i, j;
+
+  i = 0;
+  /* Break at increase. */
+  increase (&i);
+  increase (&i);
+  increase (&i);
+
+  for (i = 0; i < 10; i++)
+    {
+      j += 1; /* Condition Break. */
+    }
+
+  if (setjmp (env) == 0) /* longjmp caught */
+    {
+      call_longjmp (&env);
+    }
+  else
+	  j += 1; /* after longjmp. */
+
+  return j; /* Break at end. */
+}
diff --git a/gdb/testsuite/gdb.python/py-finish-breakpoint.exp b/gdb/testsuite/gdb.python/py-finish-breakpoint.exp
new file mode 100644
index 0000000..65eebc9
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-finish-breakpoint.exp
@@ -0,0 +1,183 @@
+# Copyright (C) 2011 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/>.
+
+# This file is part of the GDB testsuite.  It tests the mechanism
+# exposing values to Python.
+
+if $tracelevel then {
+    strace $tracelevel
+}
+
+load_lib gdb-python.exp
+
+set testfile "py-finish-breakpoint"
+set srcfile ${testfile}.c
+
+if { [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile}] } {
+    return -1
+}
+
+set remote_python_file [remote_download host ${srcdir}/${subdir}/${testfile}.py]
+
+
+# Skip all tests if Python scripting is not enabled.
+if { [skip_python_tests] } { continue }
+
+#
+# Test FinishBreakpoint in function returned by longjmp 
+#
+
+clean_restart ${testfile}
+
+if ![runto call_longjmp_1] then {
+    perror "couldn't run to breakpoint call_longjmp"
+    continue
+}
+
+gdb_test "source $remote_python_file" ".*Python script imported.*" \
+         "import python scripts"
+
+gdb_test "python ljmpBP = LongjmpFinishBreakpoint(gdb.newest_frame())" \
+         "LongjmpFinishBreakpoint init" \
+         "set finish breakpoint" 
+gdb_test "break [gdb_get_line_number "after longjmp."]" "Breakpoint.* at .*" \
+         "set BP after the jump"
+gdb_test "continue" ".*Longjmp didn't finish.*" "check FinishBP out of scope notification"
+
+#
+# Test FinishBreakpoint in BP condition evaluation 
+# (finish in dummy frame)
+#
+
+clean_restart ${testfile}
+
+set cond_line [gdb_get_line_number "Condition Break."]
+if ![runto_main] then {
+    fail "Cannot run to main."
+    return 0
+}
+
+gdb_test "source $remote_python_file" ".*Python script imported.*" \
+         "import python scripts"
+         
+gdb_test "break ${cond_line} if test_1(i,8)" ".*Breakpoint .* at .*" "set conditional BP"
+gdb_test "python TestBreakpoint()" "TestBreakpoint init" "set BP in condition"
+
+
+set msg "check FinishBreakpoint don't stop in GDB Dummy Frame"
+gdb_test_multiple "continue" $msg {
+	-re ".*test don't stop 2.*test stop.*test don't stop 4.*" {
+		pass $msg
+	}
+	-re ".*test don't stop 2.*test stop.*$gdb_prompt" {
+		fail $msg
+	}
+}
+
+gdb_test "print i" "8" "check stopped location"
+
+#
+# Test FinishBreakpoint in BP condition evaluation 
+# (finish in normal frame)
+#
+
+clean_restart ${testfile}
+
+gdb_test "source $remote_python_file" ".*Python script imported.*" \
+         "import python scripts"
+
+if ![runto_main] then {
+    fail "Cannot run to main."
+    return 0
+}
+
+gdb_test "break ${cond_line} if test(i,8)" ".*Breakpoint .* at .*" "set conditional BP"
+gdb_test "python TestBreakpoint()" "TestBreakpoint init" "set BP in condition"
+
+gdb_test "continue" ".*test don't stop 1.*test don't stop 2.*test stop.*Error in testing breakpoint condition.*The program being debugged stopped while in a function called from GDB.*" \
+         "stop in condition function"
+         
+setup_kfail "normal_stop_notification not triggered during condition evaluation" *-*-*
+gdb_test "python print gdb.breakpoints()\[2\].out_of_scope_notif" ".*False.*" "check out_of_scope notification disabled"
+gdb_test_no_output "python gdb.breakpoints()\[2\].out_of_scope_notif = False" "reestablish correct value"
+
+gdb_test "continue" "Continuing.*" "finish condition evaluation"
+gdb_test "continue" "Breakpoint.*" "stop at conditional breakpoint"
+gdb_test "print i" "8" "check stopped location"
+
+#
+# Test FinishBreakpoint in normal conditions
+#
+
+clean_restart ${testfile}
+
+if ![runto_main] then {
+    fail "Cannot run to main."
+    return 0
+}
+gdb_test_no_output "set confirm off" "disable confirmation"
+gdb_test "source $remote_python_file" ".*Python script imported.*" \
+         "import python scripts"
+gdb_test "python MyBreakpoint(\"increase_1\")" ".*Breakpoint 2.*" \
+         "create Python function breakpoint"
+gdb_test "continue" ".*Arrived at MyBreakpoint with 0.*" "check MyBreakpoint hit"
+
+# set FinishBreakpoint
+
+gdb_test "python finishbp = MyFinishBreakpoint (gdb.parse_and_eval (\"a\"), gdb.selected_frame ())" \
+         ".*Breakpoint 3.*" "set FinishBreakpoint"
+gdb_test "python print finishbp.out_of_scope_notif" ".*True.*" \
+         "check out_of_scope_notif at init"
+gdb_test "python print finishbp.return_value" ".*None.*" \
+         "check return_value at init"
+
+# check normal bp hit
+
+gdb_test "continue" ".*MyFinishBreakpoint stop with.*#0.*increase.*" \
+         "check MyFinishBreakpoint hit"
+gdb_test "python print finishbp.return_value" ".*-5.*" "check return_value"
+gdb_test "python print finishbp.out_of_scope_notif" ".*False.*" \
+         "check out_of_scope_notif disabled after hit"
+gdb_test "finish" ".*main.*" "return to main()"
+gdb_test "python print finishbp.return_value" ".*None.*" "check return_value"
+
+# check forced return / check out of scpop
+gdb_test_no_output "python finishbp.out_of_scope_notif = True" \
+         "re-enable out_of_scope_notif"
+
+gdb_test "continue" ".*Arrived at MyBreakpoint with.*" "check MyBreakpoint second hit"
+gdb_test "up" ".*increase_1.*" "go one frame up"
+gdb_test_no_output "return" "return from the frame"
+gdb_test "python print finishbp.check_scope()" ".*MyFinishBreakpoint out of scope.*True.*" \
+         "go one frame up"
+
+# check forced return / automatic notification
+
+gdb_test_no_output "python finishbp.out_of_scope_notif = True" \
+         "re-enable out_of_scope_notif"
+
+gdb_test "continue" ".*Arrived at MyBreakpoint with.*" "check MyBreakpoint third hit"
+gdb_test "up" ".*increase_1.*" "go one frame up"
+gdb_test_no_output "return" "return from the frame"
+gdb_test "next" ".*MyFinishBreakpoint out of scope.*" "check Finish breakpoint discard"
+gdb_test "python print finishbp.out_of_scope_notif" ".*False.*" "check out_of_scope_notif"
+
+# check FinishBreakpoint in main
+
+gdb_test "python MyFinishBreakpoint (None, gdb.selected_frame ())" \
+         ".*ValueError: \"FinishBreakpoint\" not meaningful in the outermost frame..*" \
+         "check FinishBP not allowed in main"
+         
+         
diff --git a/gdb/testsuite/gdb.python/py-finish-breakpoint.py b/gdb/testsuite/gdb.python/py-finish-breakpoint.py
new file mode 100644
index 0000000..f014cc6
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-finish-breakpoint.py
@@ -0,0 +1,85 @@
+# Copyright (C) 2011 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/>.
+
+# This file is part of the GDB testsuite.  It tests python Finish
+# Breakpoints.
+
+class MyBreakpoint(gdb.Breakpoint):		
+	def stop(self):
+		val = gdb.parse_and_eval ("a")
+		print "Arrived at MyBreakpoint with %d" % int(val.dereference())
+		return True
+		
+class MyFinishBreakpoint(gdb.FinishBreakpoint):
+	def __init__(self, val, frame):
+		super (MyFinishBreakpoint, self).__init__ (frame)
+		print "MyFinishBreakpoint init"
+		self.val = val
+		
+	def stop(self):
+		print "MyFinishBreakpoint stop with %d" % int(self.val.dereference())
+		gdb.execute("where 1")
+		return True
+	
+	def out_of_scope(self):
+		print "MyFinishBreakpoint out of scope..."
+
+test_finish_bp = None 
+class TestBreakpoint(gdb.Breakpoint):
+    def __init__(self):
+        gdb.Breakpoint.__init__(self, spec="test_1", internal=1)
+        self.silent = True
+        self.finish = None
+        print "TestBreakpoint init"
+        
+    def stop(self):
+    	global test_finish_bp
+        if (self.finish == None):
+            self.finish = TestFinishBreakpoint(gdb.newest_frame())
+            test_finish_bp = self.finish
+        return False
+
+
+class TestFinishBreakpoint(gdb.FinishBreakpoint):
+    def __init__(self, frame):
+        gdb.FinishBreakpoint.__init__(self, frame, internal=1)
+        self.count = 0
+        
+    def stop(self):
+        self.count += 1
+        if (self.count == 3):
+            print "test stop ..."
+            return True
+        else:
+            print "test don't stop %d" % self.count
+            return False 
+        
+    
+    def out_of_scope(self):
+        print "test didn't finish ..."
+		 
+class LongjmpFinishBreakpoint(gdb.FinishBreakpoint):
+	def __init__(self, frame):
+		gdb.FinishBreakpoint.__init__(self, frame, internal=1)
+		print "LongjmpFinishBreakpoint init"
+		
+	def stop(self):
+		print "Stopped at LongjmpFinishBreakpoint"
+        
+    
+	def out_of_scope(self):
+		print "Longjmp didn't finish ..."
+
+print "Python script imported"