2010-06-28 Phil Muldoon <pmuldoon@redhat.com>

            Tom Tromey  <tromey@redhat.com>
            Thiago Jung Bauermann  <bauerman@br.ibm.com>

	* value.c (pack_unsigned_long): New function.
	(value_from_ulongest): New function.
	* value.h (value_from_ulongest): Declare.
	* python/python.c (_initialize_python): Call
	gdbpy_initialize_thread and gdbpy_initialize_inferior.
	* python/python-internal.h: Define thread_object.
	(gdbpy_inferiors, gdbpy_selected_thread)
	(frame_info_to_frame_object, create_thread_object)
	(find_thread_object, find_inferior_object)
	(gdbpy_initialize_thread, gdbpy_initialize_inferiors)
	(gdbpy_is_value_object, get_addr_from_python): Declare.
	* python/py-value.c (builtin_type_upylong): Define.
	(convert_value_from_python): Add logic for ulongest.
	(gdbpy_is_value_object): New function.
	* python/py-utils.c (get_addr_from_python): New function.
	* python/py-frame.c (frame_info_to_frame_object): Return a PyObject.
	(gdbpy_selected_frame): Use PyObject over frame_info.
	* Makefile.in (SUBDIR_PYTHON_OBS): Add py-inferior and
	py-infthread.
	(SUBDIR_PYTHON_SRCS): Likewise.
	(py-inferior.o): New Rule.
	(py-infthread.o): New Rule.
	* python/py-inferior.c: New File.
	* python/py-infthread.c: New File.

2010-06-28  Phil Muldoon  <pmuldoon@redhat.com>
	    Tom Tromey  <tromey@redhat.com>
	    Thiago Jung Bauermann  <bauerman@br.ibm.com>

	* gdb.texinfo (Inferiors In Python): New node.
	* gdb.texinfo (Threads In Python): New node.

2010-06-28  Phil Muldoon  <pmuldoon@redhat.com>
            Tom Tromey  <tromey@redhat.com>
            Thiago Jung Bauermann  <bauerman@br.ibm.com>

	* gdb.python/py-inferior.c: New File.
	* gdb.python/py-infthread.c: New File.
	* gdb.python/py-inferior.exp: New File.
	* gdb.python/py-infthread.exp: New File.

7 files changed, 1122 insertions, 6 deletions

diff --git a/gdb/python/py-frame.c b/gdb/python/py-frame.c
index 6e9e5d3..a7df810 100644
--- a/gdb/python/py-frame.c
+++ b/gdb/python/py-frame.c
@@ -265,7 +265,7 @@ frapy_function (PyObject *self, PyObject *args)
 /* Convert a frame_info struct to a Python Frame object.
    Sets a Python exception and returns NULL on error.  */
 
-static frame_object *
+PyObject *
 frame_info_to_frame_object (struct frame_info *frame)
 {
   frame_object *frame_obj;
@@ -296,7 +296,7 @@ frame_info_to_frame_object (struct frame_info *frame)
 
   frame_obj->gdbarch = get_frame_arch (frame);
 
-  return frame_obj;
+  return (PyObject *) frame_obj;
 }
 
 /* Implementation of gdb.Frame.older (self) -> gdb.Frame.
@@ -497,7 +497,7 @@ PyObject *
 gdbpy_selected_frame (PyObject *self, PyObject *args)
 {
   struct frame_info *frame;
-  frame_object *frame_obj = NULL;   /* Initialize to appease gcc warning.  */
+  PyObject *frame_obj = NULL;   /* Initialize to appease gcc warning.  */
   volatile struct gdb_exception except;
 
   TRY_CATCH (except, RETURN_MASK_ALL)
@@ -507,7 +507,7 @@ gdbpy_selected_frame (PyObject *self, PyObject *args)
     }
   GDB_PY_HANDLE_EXCEPTION (except);
 
-  return (PyObject *) frame_obj;
+  return frame_obj;
 }
 
 /* Implementation of gdb.stop_reason_string (Integer) -> String.
diff --git a/gdb/python/py-inferior.c b/gdb/python/py-inferior.c
new file mode 100644
index 0000000..3a0feab
--- /dev/null
+++ b/gdb/python/py-inferior.c
@@ -0,0 +1,728 @@
+/* Python interface to inferiors.
+
+   Copyright (C) 2009, 2010 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 "gdbcore.h"
+#include "gdbthread.h"
+#include "inferior.h"
+#include "observer.h"
+#include "python-internal.h"
+#include "arch-utils.h"
+#include "language.h"
+
+struct threadlist_entry {
+  thread_object *thread_obj;
+  struct threadlist_entry *next;
+};
+
+typedef struct
+{
+  PyObject_HEAD
+
+  /* The inferior we represent.  */
+  struct inferior *inferior;
+
+  /* thread_object instances under this inferior.  This list owns a
+     reference to each object it contains.  */
+  struct threadlist_entry *threads;
+
+  /* Number of threads in the list.  */
+  int nthreads;
+} inferior_object;
+
+static PyTypeObject inferior_object_type;
+
+static const struct inferior_data *infpy_inf_data_key;
+
+typedef struct {
+  PyObject_HEAD
+  void *buffer;
+
+  /* These are kept just for mbpy_str.  */
+  CORE_ADDR addr;
+  CORE_ADDR length;
+} membuf_object;
+
+static PyTypeObject membuf_object_type;
+
+/* Require that INFERIOR be a valid inferior ID.  */
+#define INFPY_REQUIRE_VALID(Inferior)				\
+  do {								\
+    if (!Inferior->inferior)					\
+      {								\
+	PyErr_SetString (PyExc_RuntimeError,			\
+			 _("Inferior no longer exists."));	\
+	return NULL;						\
+      }								\
+  } while (0)
+
+/* Return a borrowed reference to the Python object of type Inferior
+   representing INFERIOR.  If the object has already been created,
+   return it,  otherwise, create it.  Return NULL on failure.  */
+PyObject *
+inferior_to_inferior_object (struct inferior *inferior)
+{
+  inferior_object *inf_obj;
+
+  inf_obj = inferior_data (inferior, infpy_inf_data_key);
+  if (!inf_obj)
+    {
+      struct cleanup *cleanup;
+      cleanup = ensure_python_env (python_gdbarch, python_language);
+
+      inf_obj = PyObject_New (inferior_object, &inferior_object_type);
+      if (!inf_obj)
+	{
+	  do_cleanups (cleanup);
+	  return NULL;
+	}
+
+      inf_obj->inferior = inferior;
+      inf_obj->threads = NULL;
+      inf_obj->nthreads = 0;
+
+      set_inferior_data (inferior, infpy_inf_data_key, inf_obj);
+
+      do_cleanups (cleanup);
+    }
+
+  return (PyObject *) inf_obj;
+}
+
+/* Finds the Python Inferior object for the given PID.  Returns a
+   borrowed reference, or NULL if PID does not match any inferior
+   obect.
+  */
+PyObject *
+find_inferior_object (int pid)
+{
+  struct inflist_entry *p;
+  struct inferior *inf = find_inferior_pid (pid);
+
+  if (inf)
+    return inferior_to_inferior_object (inf);
+
+  return NULL;
+}
+
+thread_object *
+find_thread_object (ptid_t ptid)
+{
+  int pid;
+  struct threadlist_entry *thread;
+  PyObject *inf_obj;
+
+  pid = PIDGET (ptid);
+  inf_obj = find_inferior_object (pid);
+
+  if (inf_obj)
+    for (thread = ((inferior_object *)inf_obj)->threads; thread;
+	 thread = thread->next)
+      if (ptid_equal (thread->thread_obj->thread->ptid, ptid))
+	return thread->thread_obj;
+
+  return NULL;
+}
+
+static void
+add_thread_object (struct thread_info *tp)
+{
+  struct cleanup *cleanup;
+  thread_object *thread_obj;
+  inferior_object *inf_obj;
+  struct threadlist_entry *entry;
+
+  cleanup = ensure_python_env (python_gdbarch, python_language);
+
+  thread_obj = create_thread_object (tp);
+  if (!thread_obj)
+    {
+      gdbpy_print_stack ();
+      do_cleanups (cleanup);
+      return;
+    }
+
+  inf_obj = (inferior_object *) thread_obj->inf_obj;
+
+  entry = xmalloc (sizeof (struct threadlist_entry));
+  entry->thread_obj = thread_obj;
+  entry->next = inf_obj->threads;
+
+  inf_obj->threads = entry;
+  inf_obj->nthreads++;
+
+  do_cleanups (cleanup);
+}
+
+static void
+delete_thread_object (struct thread_info *tp, int ignore)
+{
+  struct cleanup *cleanup;
+  inferior_object *inf_obj;
+  thread_object *thread_obj;
+  struct threadlist_entry **entry, *tmp;
+
+  inf_obj = (inferior_object *) find_inferior_object (PIDGET(tp->ptid));
+  if (!inf_obj)
+    return;
+
+  /* Find thread entry in its inferior's thread_list.  */
+  for (entry = &inf_obj->threads; *entry != NULL; entry =
+	 &(*entry)->next)
+    if ((*entry)->thread_obj->thread == tp)
+      break;
+
+  if (!*entry)
+    return;
+
+  cleanup = ensure_python_env (python_gdbarch, python_language);
+
+  tmp = *entry;
+  tmp->thread_obj->thread = NULL;
+
+  *entry = (*entry)->next;
+  inf_obj->nthreads--;
+
+  Py_DECREF (tmp->thread_obj);
+  xfree (tmp);
+
+  do_cleanups (cleanup);
+}
+
+static PyObject *
+infpy_threads (PyObject *self, PyObject *args)
+{
+  int i;
+  struct threadlist_entry *entry;
+  inferior_object *inf_obj = (inferior_object *) self;
+  PyObject *tuple;
+
+  INFPY_REQUIRE_VALID (inf_obj);
+
+  tuple = PyTuple_New (inf_obj->nthreads);
+  if (!tuple)
+    return NULL;
+
+  for (i = 0, entry = inf_obj->threads; i < inf_obj->nthreads;
+       i++, entry = entry->next)
+    {
+      Py_INCREF (entry->thread_obj);
+      PyTuple_SET_ITEM (tuple, i, (PyObject *) entry->thread_obj);
+    }
+
+  return tuple;
+}
+
+static PyObject *
+infpy_get_num (PyObject *self, void *closure)
+{
+  inferior_object *inf = (inferior_object *) self;
+
+  INFPY_REQUIRE_VALID (inf);
+
+  return PyLong_FromLong (inf->inferior->num);
+}
+
+static PyObject *
+infpy_get_pid (PyObject *self, void *closure)
+{
+  inferior_object *inf = (inferior_object *) self;
+
+  INFPY_REQUIRE_VALID (inf);
+
+  return PyLong_FromLong (inf->inferior->pid);
+}
+
+static PyObject *
+infpy_get_was_attached (PyObject *self, void *closure)
+{
+  inferior_object *inf = (inferior_object *) self;
+
+  INFPY_REQUIRE_VALID (inf);
+  if (inf->inferior->attach_flag)
+    Py_RETURN_TRUE;
+  Py_RETURN_FALSE;
+}
+
+static int
+build_inferior_list (struct inferior *inf, void *arg)
+{
+  PyObject *list = arg;
+  PyObject *inferior = inferior_to_inferior_object (inf);
+
+  PyList_Append (list, inferior);
+  return 0;
+}
+
+/* Implementation of gdb.inferiors () -> (gdb.Inferior, ...).
+   Returns a tuple of all inferiors.  */
+PyObject *
+gdbpy_inferiors (PyObject *unused, PyObject *unused2)
+{
+  int i = 0;
+  PyObject *list, *inferior;
+  struct inferior *inf;
+
+  list = PyList_New (0);
+  if (!list)
+    return NULL;
+
+  iterate_over_inferiors (build_inferior_list, list);
+
+  return PyList_AsTuple (list);
+}
+
+/* Membuf and memory manipulation.  */
+
+/* Implementation of gdb.read_memory (address, length).
+   Returns a Python buffer object with LENGTH bytes of the inferior's
+   memory at ADDRESS.  Both arguments are integers.  */
+static PyObject *
+infpy_read_memory (PyObject *self, PyObject *args, PyObject *kw)
+{
+  int error = 0;
+  CORE_ADDR addr, length;
+  void *buffer = NULL;
+  membuf_object *membuf_obj;
+  PyObject *addr_obj, *length_obj;
+  struct cleanup *cleanups;
+  volatile struct gdb_exception except;
+  static char *keywords[] = { "address", "length", NULL };
+
+  if (! PyArg_ParseTupleAndKeywords (args, kw, "OO", keywords,
+				     &addr_obj, &length_obj))
+    return NULL;
+
+  cleanups = make_cleanup (null_cleanup, NULL);
+
+  TRY_CATCH (except, RETURN_MASK_ALL)
+    {
+      if (!get_addr_from_python (addr_obj, &addr)
+	  || !get_addr_from_python (length_obj, &length))
+	{
+	  error = 1;
+	  break;
+	}
+
+      buffer = xmalloc (length);
+      make_cleanup (xfree, buffer);
+
+      read_memory (addr, buffer, length);
+    }
+  if (except.reason < 0)
+    {
+      do_cleanups (cleanups);
+      GDB_PY_HANDLE_EXCEPTION (except);
+    }
+
+  if (error)
+    {
+      do_cleanups (cleanups);
+      return NULL;
+    }
+
+  membuf_obj = PyObject_New (membuf_object, &membuf_object_type);
+  if (membuf_obj == NULL)
+    {
+      PyErr_SetString (PyExc_MemoryError,
+		       _("Could not allocate memory buffer object."));
+      do_cleanups (cleanups);
+      return NULL;
+    }
+
+  discard_cleanups (cleanups);
+
+  membuf_obj->buffer = buffer;
+  membuf_obj->addr = addr;
+  membuf_obj->length = length;
+
+  return PyBuffer_FromReadWriteObject ((PyObject *) membuf_obj, 0,
+				       Py_END_OF_BUFFER);
+}
+
+/* Implementation of gdb.write_memory (address, buffer [, length]).
+   Writes the contents of BUFFER (a Python object supporting the read
+   buffer protocol) at ADDRESS in the inferior's memory.  Write LENGTH
+   bytes from BUFFER, or its entire contents if the argument is not
+   provided.  The function returns nothing.  */
+static PyObject *
+infpy_write_memory (PyObject *self, PyObject *args, PyObject *kw)
+{
+  int buf_len, error = 0;
+  const char *buffer;
+  CORE_ADDR addr, length;
+  PyObject *addr_obj, *length_obj = NULL;
+  volatile struct gdb_exception except;
+  static char *keywords[] = { "address", "buffer", "length", NULL };
+
+
+  if (! PyArg_ParseTupleAndKeywords (args, kw, "Os#|O", keywords,
+				     &addr_obj, &buffer, &buf_len,
+				     &length_obj))
+    return NULL;
+
+  TRY_CATCH (except, RETURN_MASK_ALL)
+    {
+      if (!get_addr_from_python (addr_obj, &addr))
+	{
+	  error = 1;
+	  break;
+	}
+
+      if (!length_obj)
+	length = buf_len;
+      else if (!get_addr_from_python (length_obj, &length))
+	{
+	  error = 1;
+	  break;
+	}
+      write_memory (addr, buffer, length);
+    }
+  GDB_PY_HANDLE_EXCEPTION (except);
+
+  if (error)
+    return NULL;
+
+  Py_RETURN_NONE;
+}
+
+/* Destructor of Membuf objects.  */
+static void
+mbpy_dealloc (PyObject *self)
+{
+  xfree (((membuf_object *) self)->buffer);
+  self->ob_type->tp_free (self);
+}
+
+/* Return a description of the Membuf object.  */
+static PyObject *
+mbpy_str (PyObject *self)
+{
+  membuf_object *membuf_obj = (membuf_object *) self;
+
+  return PyString_FromFormat (_("Memory buffer for address %s, \
+which is %s bytes long."),
+			      paddress (python_gdbarch, membuf_obj->addr),
+			      pulongest (membuf_obj->length));
+}
+
+static Py_ssize_t
+get_read_buffer (PyObject *self, Py_ssize_t segment, void **ptrptr)
+{
+  membuf_object *membuf_obj = (membuf_object *) self;
+
+  if (segment)
+    {
+      PyErr_SetString (PyExc_SystemError,
+		       _("The memory buffer supports only one segment."));
+      return -1;
+    }
+
+  *ptrptr = membuf_obj->buffer;
+
+  return membuf_obj->length;
+}
+
+static Py_ssize_t
+get_write_buffer (PyObject *self, Py_ssize_t segment, void **ptrptr)
+{
+  return get_read_buffer (self, segment, ptrptr);
+}
+
+static Py_ssize_t
+get_seg_count (PyObject *self, Py_ssize_t *lenp)
+{
+  if (lenp)
+    *lenp = ((membuf_object *) self)->length;
+
+  return 1;
+}
+
+static Py_ssize_t
+get_char_buffer (PyObject *self, Py_ssize_t segment, char **ptrptr)
+{
+  void *ptr = NULL;
+  Py_ssize_t ret;
+
+  ret = get_read_buffer (self, segment, &ptr);
+  *ptrptr = (char *) ptr;
+
+  return ret;
+}
+
+/* Implementation of
+   gdb.search_memory (address, length, pattern).  ADDRESS is the
+   address to start the search.  LENGTH specifies the scope of the
+   search from ADDRESS.  PATTERN is the pattern to search for (and
+   must be a Python object supporting the buffer protocol).
+   Returns a Python Long object holding the address where the pattern
+   was located, or if the pattern was not found, returns None.  */
+static PyObject *
+infpy_search_memory (PyObject *self, PyObject *args, PyObject *kw)
+{
+  CORE_ADDR start_addr, length;
+  static char *keywords[] = { "address", "length", "pattern", NULL };
+  PyObject *pattern, *start_addr_obj, *length_obj;
+  volatile struct gdb_exception except;
+  Py_ssize_t pattern_size;
+  const void *buffer;
+  CORE_ADDR found_addr;
+  int found = 0;
+
+  if (! PyArg_ParseTupleAndKeywords (args, kw, "OOO", keywords,
+				     &start_addr_obj, &length_obj,
+				     &pattern))
+    return NULL;
+
+  if (get_addr_from_python (start_addr_obj, &start_addr)
+      && get_addr_from_python (length_obj, &length))
+    {
+      if (!length)
+	{
+	  PyErr_SetString (PyExc_ValueError,
+			   _("Search range is empty."));
+	  return NULL;
+	}
+      /* Watch for overflows.  */
+      else if (length > CORE_ADDR_MAX
+	       || (start_addr + length - 1) < start_addr)
+	{
+	  PyErr_SetString (PyExc_ValueError,
+			   _("The search range is too large."));
+
+	  return NULL;
+	}
+    }
+  else
+    {
+      PyErr_SetString (PyExc_RuntimeError,
+		       _("Cannot get search address/range from Python."));
+
+      return NULL;
+    }
+
+  if (!PyObject_CheckReadBuffer (pattern))
+    {
+      PyErr_SetString (PyExc_RuntimeError,
+		       _("The pattern is not a Python buffer."));
+
+      return NULL;
+    }
+
+  if (PyObject_AsReadBuffer (pattern, &buffer, &pattern_size) == -1)
+    return NULL;
+
+  TRY_CATCH (except, RETURN_MASK_ALL)
+    {
+      found = target_search_memory (start_addr, length,
+				    buffer, pattern_size,
+				    &found_addr);
+    }
+  GDB_PY_HANDLE_EXCEPTION (except);
+
+  if (found)
+    return PyLong_FromLong (found_addr);
+  else
+    Py_RETURN_NONE;
+}
+
+
+/* Clear the INFERIOR pointer in an Inferior object and clear the
+   thread list.  */
+static void
+py_free_inferior (struct inferior *inf, void *datum)
+{
+
+  struct cleanup *cleanup;
+  inferior_object *inf_obj = datum;
+  struct threadlist_entry *th_entry, *th_tmp;
+
+  cleanup = ensure_python_env (python_gdbarch, python_language);
+
+  inf_obj->inferior = NULL;
+
+  /* Deallocate threads list.  */
+  for (th_entry = inf_obj->threads; th_entry != NULL;)
+    {
+      Py_DECREF (th_entry->thread_obj);
+
+      th_tmp = th_entry;
+      th_entry = th_entry->next;
+      xfree (th_tmp);
+    }
+
+  inf_obj->nthreads = 0;
+
+  Py_DECREF ((PyObject *) inf_obj);
+  do_cleanups (cleanup);
+}
+
+void
+gdbpy_initialize_inferior (void)
+{
+  if (PyType_Ready (&inferior_object_type) < 0)
+    return;
+
+  Py_INCREF (&inferior_object_type);
+  PyModule_AddObject (gdb_module, "Inferior",
+		      (PyObject *) &inferior_object_type);
+
+  infpy_inf_data_key =
+    register_inferior_data_with_cleanup (py_free_inferior);
+
+  observer_attach_new_thread (add_thread_object);
+  observer_attach_thread_exit (delete_thread_object);
+
+  if (PyType_Ready (&membuf_object_type) < 0)
+    return;
+
+  Py_INCREF (&membuf_object_type);
+  PyModule_AddObject (gdb_module, "Membuf", (PyObject *)
+		      &membuf_object_type);
+}
+
+static PyGetSetDef inferior_object_getset[] =
+{
+  { "num", infpy_get_num, NULL, "ID of inferior, as assigned by GDB.", NULL },
+  { "pid", infpy_get_pid, NULL, "PID of inferior, as assigned by the OS.",
+    NULL },
+  { "was_attached", infpy_get_was_attached, NULL,
+    "True if the inferior was created using 'attach'.", NULL },
+  { NULL }
+};
+
+static PyMethodDef inferior_object_methods[] =
+{
+  { "threads", infpy_threads, METH_NOARGS,
+    "Return all the threads of this inferior." },
+  { "read_memory", (PyCFunction) infpy_read_memory,
+    METH_VARARGS | METH_KEYWORDS,
+    "read_memory (address, length) -> buffer\n\
+Return a buffer object for reading from the inferior's memory." },
+  { "write_memory", (PyCFunction) infpy_write_memory,
+    METH_VARARGS | METH_KEYWORDS,
+    "write_memory (address, buffer [, length])\n\
+Write the given buffer object to the inferior's memory." },
+  { "search_memory", (PyCFunction) infpy_search_memory,
+    METH_VARARGS | METH_KEYWORDS,
+    "search_memory (address, length, pattern) -> long\n\
+Return a long with the address of a match, or None." },
+  { NULL }
+};
+
+static PyTypeObject inferior_object_type =
+{
+  PyObject_HEAD_INIT (NULL)
+  0,				  /* ob_size */
+  "gdb.Inferior",		  /* tp_name */
+  sizeof (inferior_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_HAVE_ITER,  /* tp_flags */
+  "GDB inferior object",	  /* tp_doc */
+  0,				  /* tp_traverse */
+  0,				  /* tp_clear */
+  0,				  /* tp_richcompare */
+  0,				  /* tp_weaklistoffset */
+  0,				  /* tp_iter */
+  0,				  /* tp_iternext */
+  inferior_object_methods,	  /* tp_methods */
+  0,				  /* tp_members */
+  inferior_object_getset,	  /* tp_getset */
+  0,				  /* tp_base */
+  0,				  /* tp_dict */
+  0,				  /* tp_descr_get */
+  0,				  /* tp_descr_set */
+  0,				  /* tp_dictoffset */
+  0,				  /* tp_init */
+  0				  /* tp_alloc */
+};
+
+/* Python doesn't provide a decent way to get compatibility here.  */
+#if HAVE_LIBPYTHON2_4
+#define CHARBUFFERPROC_NAME getcharbufferproc
+#else
+#define CHARBUFFERPROC_NAME charbufferproc
+#endif
+
+static PyBufferProcs buffer_procs = {
+  get_read_buffer,
+  get_write_buffer,
+  get_seg_count,
+  /* The cast here works around a difference between Python 2.4 and
+     Python 2.5.  */
+  (CHARBUFFERPROC_NAME) get_char_buffer
+};
+
+static PyTypeObject membuf_object_type = {
+  PyObject_HEAD_INIT (NULL)
+  0,				  /*ob_size*/
+  "gdb.Membuf",			  /*tp_name*/
+  sizeof (membuf_object),	  /*tp_basicsize*/
+  0,				  /*tp_itemsize*/
+  mbpy_dealloc,			  /*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*/
+  mbpy_str,			  /*tp_str*/
+  0,				  /*tp_getattro*/
+  0,				  /*tp_setattro*/
+  &buffer_procs,		  /*tp_as_buffer*/
+  Py_TPFLAGS_DEFAULT,		  /*tp_flags*/
+  "GDB memory buffer object", 	  /*tp_doc*/
+  0,				  /* tp_traverse */
+  0,				  /* tp_clear */
+  0,				  /* tp_richcompare */
+  0,				  /* tp_weaklistoffset */
+  0,				  /* tp_iter */
+  0,				  /* tp_iternext */
+  0,				  /* tp_methods */
+  0,				  /* tp_members */
+  0,				  /* tp_getset */
+  0,				  /* tp_base */
+  0,				  /* tp_dict */
+  0,				  /* tp_descr_get */
+  0,				  /* tp_descr_set */
+  0,				  /* tp_dictoffset */
+  0,				  /* tp_init */
+  0,				  /* tp_alloc */
+  PyType_GenericNew		  /* tp_new */
+};
diff --git a/gdb/python/py-infthread.c b/gdb/python/py-infthread.c
new file mode 100644
index 0000000..86aba50
--- /dev/null
+++ b/gdb/python/py-infthread.c
@@ -0,0 +1,269 @@
+/* Python interface to inferior threads.
+
+   Copyright (C) 2009, 2010 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 "gdbthread.h"
+#include "inferior.h"
+#include "python-internal.h"
+
+static PyTypeObject thread_object_type;
+
+/* Require that INFERIOR be a valid inferior ID.  */
+#define THPY_REQUIRE_VALID(Thread)				\
+  do {								\
+    if (!Thread->thread)					\
+      {								\
+	PyErr_SetString (PyExc_RuntimeError,			\
+			 _("Thread no longer exists."));	\
+	return NULL;						\
+      }								\
+  } while (0)
+
+
+
+thread_object *
+create_thread_object (struct thread_info *tp)
+{
+  thread_object *thread_obj;
+
+  thread_obj = PyObject_New (thread_object, &thread_object_type);
+  if (!thread_obj)
+    return NULL;
+
+  thread_obj->thread = tp;
+  thread_obj->inf_obj = find_inferior_object (PIDGET (tp->ptid));
+  Py_INCREF (thread_obj->inf_obj);
+
+  return thread_obj;
+}
+
+
+
+static void
+thpy_dealloc (PyObject *self)
+{
+  Py_DECREF (((thread_object *) self)->inf_obj);
+  self->ob_type->tp_free (self);
+}
+
+static PyObject *
+thpy_get_num (PyObject *self, void *closure)
+{
+  thread_object *thread_obj = (thread_object *) self;
+
+  THPY_REQUIRE_VALID (thread_obj);
+
+  return PyLong_FromLong (thread_obj->thread->num);
+}
+
+/* Getter for InferiorThread.ptid  -> (pid, lwp, tid).
+   Returns a tuple with the thread's ptid components.  */
+static PyObject *
+thpy_get_ptid (PyObject *self, void *closure)
+{
+  int pid;
+  long tid, lwp;
+  thread_object *thread_obj = (thread_object *) self;
+  PyObject *ret;
+
+  THPY_REQUIRE_VALID (thread_obj);
+
+  ret = PyTuple_New (3);
+  if (!ret)
+    return NULL;
+
+  pid = ptid_get_pid (thread_obj->thread->ptid);
+  lwp = ptid_get_lwp (thread_obj->thread->ptid);
+  tid = ptid_get_tid (thread_obj->thread->ptid);
+
+  PyTuple_SET_ITEM (ret, 0, PyInt_FromLong (pid));
+  PyTuple_SET_ITEM (ret, 1, PyInt_FromLong (lwp));
+  PyTuple_SET_ITEM (ret, 2, PyInt_FromLong (tid));
+
+  return ret;
+}
+
+/* Implementation of InferiorThread.switch ().
+   Makes this the GDB selected thread.  */
+static PyObject *
+thpy_switch (PyObject *self, PyObject *args)
+{
+  thread_object *thread_obj = (thread_object *) self;
+  struct cleanup *cleanup;
+  volatile struct gdb_exception except;
+
+  THPY_REQUIRE_VALID (thread_obj);
+
+  TRY_CATCH (except, RETURN_MASK_ALL)
+    {
+      switch_to_thread (thread_obj->thread->ptid);
+    }
+  GDB_PY_HANDLE_EXCEPTION (except);
+
+  Py_RETURN_NONE;
+}
+
+/* Implementation of InferiorThread.is_stopped () -> Boolean.
+   Return whether the thread is stopped.  */
+static PyObject *
+thpy_is_stopped (PyObject *self, PyObject *args)
+{
+  thread_object *thread_obj = (thread_object *) self;
+
+  THPY_REQUIRE_VALID (thread_obj);
+
+  if (is_stopped (thread_obj->thread->ptid))
+    Py_RETURN_TRUE;
+
+  Py_RETURN_FALSE;
+}
+
+/* Implementation of InferiorThread.is_running () -> Boolean.
+   Return whether the thread is running.  */
+static PyObject *
+thpy_is_running (PyObject *self, PyObject *args)
+{
+  thread_object *thread_obj = (thread_object *) self;
+
+  THPY_REQUIRE_VALID (thread_obj);
+
+  if (is_running (thread_obj->thread->ptid))
+    Py_RETURN_TRUE;
+
+  Py_RETURN_FALSE;
+}
+
+/* Implementation of InferiorThread.is_exited () -> Boolean.
+   Return whether the thread is exited.  */
+static PyObject *
+thpy_is_exited (PyObject *self, PyObject *args)
+{
+  thread_object *thread_obj = (thread_object *) self;
+
+  THPY_REQUIRE_VALID (thread_obj);
+
+  if (is_exited (thread_obj->thread->ptid))
+    Py_RETURN_TRUE;
+
+  Py_RETURN_FALSE;
+}
+
+
+
+/* Implementation of gdb.selected_thread () -> gdb.InferiorThread.
+   Returns the selected thread object.  */
+PyObject *
+gdbpy_selected_thread (PyObject *self, PyObject *args)
+{
+  PyObject *thread_obj;
+
+  thread_obj = (PyObject *) find_thread_object (inferior_ptid);
+  if (thread_obj)
+    {
+      Py_INCREF (thread_obj);
+      return thread_obj;
+    }
+
+  Py_RETURN_NONE;
+}
+
+
+
+void
+gdbpy_initialize_thread (void)
+{
+  if (PyType_Ready (&thread_object_type) < 0)
+    return;
+
+  Py_INCREF (&thread_object_type);
+  PyModule_AddObject (gdb_module, "InferiorThread",
+		      (PyObject *) &thread_object_type);
+}
+
+
+
+static PyGetSetDef thread_object_getset[] =
+{
+  { "num", thpy_get_num, NULL, "ID of the thread, as assigned by GDB.", NULL },
+  { "ptid", thpy_get_ptid, NULL, "ID of the thread, as assigned by the OS.",
+    NULL },
+
+  { NULL }
+};
+
+static PyMethodDef thread_object_methods[] =
+{
+  { "switch", thpy_switch, METH_NOARGS,
+    "switch ()\n\
+Makes this the GDB selected thread." },
+  { "is_stopped", thpy_is_stopped, METH_NOARGS,
+    "is_stopped () -> Boolean\n\
+Return whether the thread is stopped." },
+  { "is_running", thpy_is_running, METH_NOARGS,
+    "is_running () -> Boolean\n\
+Return whether the thread is running." },
+  { "is_exited", thpy_is_exited, METH_NOARGS,
+    "is_exited () -> Boolean\n\
+Return whether the thread is exited." },
+
+  { NULL }
+};
+
+static PyTypeObject thread_object_type =
+{
+  PyObject_HEAD_INIT (NULL)
+  0,				  /*ob_size*/
+  "gdb.InferiorThread",		  /*tp_name*/
+  sizeof (thread_object),	  /*tp_basicsize*/
+  0,				  /*tp_itemsize*/
+  thpy_dealloc,			  /*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_HAVE_ITER,  /*tp_flags*/
+  "GDB thread object",		  /* tp_doc */
+  0,				  /* tp_traverse */
+  0,				  /* tp_clear */
+  0,				  /* tp_richcompare */
+  0,				  /* tp_weaklistoffset */
+  0,				  /* tp_iter */
+  0,				  /* tp_iternext */
+  thread_object_methods,	  /* tp_methods */
+  0,				  /* tp_members */
+  thread_object_getset,		  /* tp_getset */
+  0,				  /* tp_base */
+  0,				  /* tp_dict */
+  0,				  /* tp_descr_get */
+  0,				  /* tp_descr_set */
+  0,				  /* tp_dictoffset */
+  0,				  /* tp_init */
+  0				  /* tp_alloc */
+};
diff --git a/gdb/python/py-utils.c b/gdb/python/py-utils.c
index 944e6b4..90609fa 100644
--- a/gdb/python/py-utils.c
+++ b/gdb/python/py-utils.c
@@ -19,6 +19,7 @@
 
 #include "defs.h"
 #include "charset.h"
+#include "value.h"
 #include "python-internal.h"
 
 
@@ -272,3 +273,51 @@ gdbpy_exception_to_string (PyObject *ptype, PyObject *pvalue)
 
   return str;
 }
+
+/* Converts OBJ to a CORE_ADDR value.
+
+   Returns 1 on success or 0 on failure, with a Python exception set.  This
+   function can also throw GDB exceptions.
+*/
+
+int
+get_addr_from_python (PyObject *obj, CORE_ADDR *addr)
+{
+  if (gdbpy_is_value_object (obj))
+    *addr = value_as_address (value_object_to_value (obj));
+  else if (PyLong_Check (obj))
+    {
+      /* Assume CORE_ADDR corresponds to unsigned long.  */
+      *addr = PyLong_AsUnsignedLong (obj);
+      if (PyErr_Occurred () != NULL)
+	return 0;
+    }
+  else if (PyInt_Check (obj))
+    {
+      long val;
+
+      /* Assume CORE_ADDR corresponds to unsigned long.  */
+      val = PyInt_AsLong (obj);
+
+      if (val >= 0)
+	*addr = val;
+      else
+      {
+	/* If no error ocurred, VAL is indeed negative.  */
+	if (PyErr_Occurred () != NULL)
+	  return 0;
+
+	PyErr_SetString (PyExc_ValueError,
+			 _("Supplied address is negative."));
+	return 0;
+      }
+    }
+  else
+    {
+      PyErr_SetString (PyExc_TypeError,
+		       _("Invalid type for address."));
+      return 0;
+    }
+
+  return 1;
+}
diff --git a/gdb/python/py-value.c b/gdb/python/py-value.c
index eb20de8..2024021 100644
--- a/gdb/python/py-value.c
+++ b/gdb/python/py-value.c
@@ -43,6 +43,10 @@
 /* Python's long type corresponds to C's long long type.  */
 #define builtin_type_pylong builtin_type (python_gdbarch)->builtin_long_long
 
+/* Python's long type corresponds to C's long long type.  Unsigned version.  */
+#define builtin_type_upylong builtin_type \
+  (python_gdbarch)->builtin_unsigned_long_long
+
 #define builtin_type_pybool \
   language_bool_type (python_language, python_gdbarch)
 
@@ -961,7 +965,34 @@ convert_value_from_python (PyObject *obj)
 	{
 	  LONGEST l = PyLong_AsLongLong (obj);
 
-	  if (! PyErr_Occurred ())
+	  if (PyErr_Occurred ())
+	    {
+	      /* If the error was an overflow, we can try converting to
+	         ULONGEST instead.  */
+	      if (PyErr_ExceptionMatches (PyExc_OverflowError))
+		{
+		  PyObject *etype, *evalue, *etraceback, *zero;
+
+		  PyErr_Fetch (&etype, &evalue, &etraceback);
+		  zero = PyInt_FromLong (0);
+
+		  /* Check whether obj is positive.  */
+		  if (PyObject_RichCompareBool (obj, zero, Py_GT) > 0)
+		    {
+		      ULONGEST ul;
+
+		      ul = PyLong_AsUnsignedLongLong (obj);
+		      if (! PyErr_Occurred ())
+			value = value_from_ulongest (builtin_type_upylong, ul);
+		    }
+		  else
+		    /* There's nothing we can do.  */
+		    PyErr_Restore (etype, evalue, etraceback);
+
+		  Py_DECREF (zero);
+		}
+	    }
+	  else
 	    value = value_from_longest (builtin_type_pylong, l);
 	}
       else if (PyFloat_Check (obj))
@@ -1028,6 +1059,14 @@ gdbpy_history (PyObject *self, PyObject *args)
   return value_to_value_object (res_val);
 }
 
+/* Returns 1 in OBJ is a gdb.Value object, 0 otherwise.  */
+
+int
+gdbpy_is_value_object (PyObject *obj)
+{
+  return PyObject_TypeCheck (obj, &value_object_type);
+}
+
 void
 gdbpy_initialize_values (void)
 {
diff --git a/gdb/python/python-internal.h b/gdb/python/python-internal.h
index 5bd2a4b..daaed2c 100644
--- a/gdb/python/python-internal.h
+++ b/gdb/python/python-internal.h
@@ -80,6 +80,17 @@ extern PyTypeObject value_object_type;
 extern PyTypeObject block_object_type;
 extern PyTypeObject symbol_object_type;
 
+typedef struct
+{
+  PyObject_HEAD
+
+  /* The thread we represent.  */
+  struct thread_info *thread;
+
+  /* The Inferior object to which this thread belongs.  */
+  PyObject *inf_obj;
+} thread_object;
+
 extern struct cmd_list_element *set_python_list;
 extern struct cmd_list_element *show_python_list;
 
@@ -92,6 +103,8 @@ PyObject *gdbpy_block_for_pc (PyObject *self, PyObject *args);
 PyObject *gdbpy_lookup_type (PyObject *self, PyObject *args, PyObject *kw);
 PyObject *gdbpy_create_lazy_string_object (CORE_ADDR address, long length,
 					   const char *encoding, struct type *type);
+PyObject *gdbpy_inferiors (PyObject *unused, PyObject *unused2);
+PyObject *gdbpy_selected_thread (PyObject *self, PyObject *args);
 PyObject *gdbpy_string_to_argv (PyObject *self, PyObject *args);
 PyObject *gdbpy_get_hook_function (const char *);
 PyObject *gdbpy_parameter (PyObject *self, PyObject *args);
@@ -106,6 +119,7 @@ PyObject *symbol_to_symbol_object (struct symbol *sym);
 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);
 
 PyObject *pspace_to_pspace_object (struct program_space *);
 PyObject *pspy_get_printers (PyObject *, void *);
@@ -113,6 +127,10 @@ PyObject *pspy_get_printers (PyObject *, void *);
 PyObject *objfile_to_objfile_object (struct objfile *);
 PyObject *objfpy_get_printers (PyObject *, void *);
 
+thread_object *create_thread_object (struct thread_info *tp);
+thread_object *find_thread_object (ptid_t ptid);
+PyObject *find_inferior_object (int pid);
+
 struct block *block_object_to_block (PyObject *obj);
 struct symbol *symbol_object_to_symbol (PyObject *obj);
 struct value *value_object_to_value (PyObject *self);
@@ -136,6 +154,8 @@ void gdbpy_initialize_objfile (void);
 void gdbpy_initialize_breakpoints (void);
 void gdbpy_initialize_lazy_string (void);
 void gdbpy_initialize_parameters (void);
+void gdbpy_initialize_thread (void);
+void gdbpy_initialize_inferior (void);
 
 struct cleanup *make_cleanup_py_decref (PyObject *py);
 
@@ -188,6 +208,8 @@ gdb_byte *gdbpy_extract_lazy_string (PyObject *string,
 				     struct type **str_type, 
 				     long *length, char **encoding);
 
+int gdbpy_is_value_object (PyObject *obj);
+
 /* Note that these are declared here, and not in python.h with the
    other pretty-printer functions, because they refer to PyObject.  */
 PyObject *apply_varobj_pretty_printer (PyObject *print_obj,
@@ -204,4 +226,6 @@ extern PyObject *gdbpy_enabled_cst;
 
 extern PyObject *gdbpy_gdberror_exc;
 
+int get_addr_from_python (PyObject *obj, CORE_ADDR *addr);
+
 #endif /* GDB_PYTHON_INTERNAL_H */
diff --git a/gdb/python/python.c b/gdb/python/python.c
index b9a8cf6..6680126 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -757,6 +757,8 @@ Enables or disables printing of Python stack traces."),
   gdbpy_initialize_objfile ();
   gdbpy_initialize_breakpoints ();
   gdbpy_initialize_lazy_string ();
+  gdbpy_initialize_thread ();
+  gdbpy_initialize_inferior ();
 
   PyRun_SimpleString ("import gdb");
   PyRun_SimpleString ("gdb.pretty_printers = []");
@@ -884,7 +886,12 @@ Arguments are separate by spaces and may be quoted."
     "Write a string using gdb's filtered stream." },
   { "flush", gdbpy_flush, METH_NOARGS,
     "Flush gdb's filtered stdout stream." },
-
+  { "selected_thread", gdbpy_selected_thread, METH_NOARGS,
+    "selected_thread () -> gdb.InferiorThread.\n\
+Return the selected thread object." },
+  { "inferiors", gdbpy_inferiors, METH_NOARGS,
+    "inferiors () -> (gdb.Inferior, ...).\n\
+Return a tuple containing all inferiors." },
   {NULL, NULL, 0, NULL}
 };