Introduce gdb.FinishBreakpoint in Python

* Makefile.in (SUBDIR_PYTHON_OBS): Add py-finishbreakpoint.o.
	(SUBDIR_PYTHON_SRCS): Add python/py-finishbreakpoint.c.
	Add build rule for this file.
	* infcmd.c (print_return_value): Split to create get_return_value.
	(get_return_value): New function based on print_return_value. Handle
	case where stop_registers are not set.
	* inferior.h (get_return_value): New prototype.
	* python/py-breakpoint.c (bppy_pending_object): Make non-static.
	(gdbpy_breakpoint_created): Set is_py_finish_bp is necessary.
	(struct breakpoint_object): Move to python-internal.h
	(BPPY_REQUIRE_VALID): Likewise.
	(BPPY_SET_REQUIRE_VALID): Likewise.
	(gdbpy_breakpoint_created): Initialize is_finish_bp.
	(gdbpy_should_stop): Add  pre/post hooks before/after calling stop
	method.
	* python/python-internal.h (breakpoint_object_type): Add as extern.
	(bppy_pending_object): Likewise.
	(typedef struct breakpoint_object) Removed.
	(struct breakpoint_object): Moved from py-breakpoint.c.
	Add field is_finish_bp.
	(BPPY_REQUIRE_VALID): Moved from py-breakpoint.c.
	(BPPY_SET_REQUIRE_VALID): Likewise.
	(frame_object_to_frame_info): New prototype.
	(gdbpy_initialize_finishbreakpoints): New prototype.
	(bpfinishpy_is_finish_bp): Likewise.
	(bpfinishpy_pre_stop_hook): Likewise.
	(bpfinishpy_post_stop_hook): Likewise.
	* python/py-finishbreakpoint.c: New file.
	* python/py-frame.c(frame_object_to_frame_info): Make non-static and
	accept PyObject instead of frame_object.
	(frapy_is_valid): Don't cast to frame_object.
	(frapy_name): Likewise.
	(frapy_type): Likewise.
	(frapy_unwind_stop_reason): Likewise.
	(frapy_pc): Likewise.
	(frapy_block): Likewise.
	(frapy_function): Likewise.
	(frapy_older): Likewise.
	(frapy_newer): Likewise.
	(frapy_find_sal): Likewise.
	(frapy_read_var): Likewise.
	(frapy_select): Likewise.
	* python/python.c (gdbpy_is_stopped_at_finish_bp): New noop function.
	(_initialize_python): Add gdbpy_initialize_finishbreakpoints.
	* python/python.h: Include breakpoint.h
	(gdbpy_is_stopped_at_finish_bp): New prototype.

doc/
	* gdb.texinfo (Finish Breakpoints in Python): New subsection.
	(Python API): Add menu entry for Finish Breakpoints.

testsuite/
	* Makefile.in (EXECUTABLES): Add py-finish-breakpoint and
	py-finish-breakpoint2
	(MISCALLANEOUS): Add py-events-shlib.so and py-events-shlib-nodebug.so
	* gdb.python/py-breakpoint.exp (mult_line): Define and use variable
	instead of line number.
	* gdb.python/py-finish-breakpoint.c: New file.
	* gdb.python/py-finish-breakpoint.exp: New file.
	* gdb.python/py-finish-breakpoint.py: New file.
	* gdb.python/py-finish-breakpoint2.cc: New file.
	* gdb.python/py-finish-breakpoint2.exp: New file.
	* gdb.python/py-finish-breakpoint2.py: New file.

gdb/testsuite/gdb.python/py-finish-breakpoint.c

@@ -0,0 +1,100 @@
+/* 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>
+#include <stdlib.h>
+#include <unistd.h>
+
+/* Defined in py-events-shlib.h.  */
+extern void do_nothing (void);
+
+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);
+}
+
+void
+test_exec_exit (int do_exit)
+{
+  if (do_exit)
+    exit (0);
+  else
+    execl ("/bin/echo", "echo", "-1", (char *)0);
+}
+
+int main (int argc, char *argv[])
+{
+  jmp_buf env;
+  int foo = 5;
+  int bar = 42;
+  int i, j;
+
+  do_nothing ();
+
+  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.  */
+
+  test_exec_exit (1);
+
+  return j; /* Break at end.  */
+}