Home | History | Annotate | Line # | Download | only in python
py-inferior.c revision 1.3
      1 /* Python interface to inferiors.
      2 
      3    Copyright (C) 2009-2015 Free Software Foundation, Inc.
      4 
      5    This file is part of GDB.
      6 
      7    This program is free software; you can redistribute it and/or modify
      8    it under the terms of the GNU General Public License as published by
      9    the Free Software Foundation; either version 3 of the License, or
     10    (at your option) any later version.
     11 
     12    This program is distributed in the hope that it will be useful,
     13    but WITHOUT ANY WARRANTY; without even the implied warranty of
     14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     15    GNU General Public License for more details.
     16 
     17    You should have received a copy of the GNU General Public License
     18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
     19 
     20 #include "defs.h"
     21 #include "gdbcore.h"
     22 #include "gdbthread.h"
     23 #include "inferior.h"
     24 #include "objfiles.h"
     25 #include "observer.h"
     26 #include "python-internal.h"
     27 #include "arch-utils.h"
     28 #include "language.h"
     29 #include "gdb_signals.h"
     30 #include "py-event.h"
     31 #include "py-stopevent.h"
     32 
     33 struct threadlist_entry {
     34   thread_object *thread_obj;
     35   struct threadlist_entry *next;
     36 };
     37 
     38 typedef struct
     39 {
     40   PyObject_HEAD
     41 
     42   /* The inferior we represent.  */
     43   struct inferior *inferior;
     44 
     45   /* thread_object instances under this inferior.  This list owns a
     46      reference to each object it contains.  */
     47   struct threadlist_entry *threads;
     48 
     49   /* Number of threads in the list.  */
     50   int nthreads;
     51 } inferior_object;
     52 
     53 static PyTypeObject inferior_object_type
     54     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("inferior_object");
     55 
     56 static const struct inferior_data *infpy_inf_data_key;
     57 
     58 typedef struct {
     59   PyObject_HEAD
     60   void *buffer;
     61 
     62   /* These are kept just for mbpy_str.  */
     63   CORE_ADDR addr;
     64   CORE_ADDR length;
     65 } membuf_object;
     66 
     67 static PyTypeObject membuf_object_type
     68     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("membuf_object");
     69 
     70 /* Require that INFERIOR be a valid inferior ID.  */
     71 #define INFPY_REQUIRE_VALID(Inferior)				\
     72   do {								\
     73     if (!Inferior->inferior)					\
     74       {								\
     75 	PyErr_SetString (PyExc_RuntimeError,			\
     76 			 _("Inferior no longer exists."));	\
     77 	return NULL;						\
     78       }								\
     79   } while (0)
     80 
     81 static void
     82 python_on_normal_stop (struct bpstats *bs, int print_frame)
     83 {
     84   struct cleanup *cleanup;
     85   enum gdb_signal stop_signal;
     86 
     87   if (!gdb_python_initialized)
     88     return;
     89 
     90   if (!find_thread_ptid (inferior_ptid))
     91       return;
     92 
     93   stop_signal = inferior_thread ()->suspend.stop_signal;
     94 
     95   cleanup = ensure_python_env (get_current_arch (), current_language);
     96 
     97   if (emit_stop_event (bs, stop_signal) < 0)
     98     gdbpy_print_stack ();
     99 
    100   do_cleanups (cleanup);
    101 }
    102 
    103 static void
    104 python_on_resume (ptid_t ptid)
    105 {
    106   struct cleanup *cleanup;
    107 
    108   if (!gdb_python_initialized)
    109     return;
    110 
    111   cleanup = ensure_python_env (target_gdbarch (), current_language);
    112 
    113   if (emit_continue_event (ptid) < 0)
    114     gdbpy_print_stack ();
    115 
    116   do_cleanups (cleanup);
    117 }
    118 
    119 /* Callback, registered as an observer, that notifies Python listeners
    120    when an inferior function call is about to be made. */
    121 
    122 static void
    123 python_on_inferior_call_pre (ptid_t thread, CORE_ADDR address)
    124 {
    125   struct cleanup *cleanup;
    126 
    127   cleanup = ensure_python_env (target_gdbarch (), current_language);
    128 
    129   if (emit_inferior_call_event (INFERIOR_CALL_PRE, thread, address) < 0)
    130     gdbpy_print_stack ();
    131 
    132   do_cleanups (cleanup);
    133 }
    134 
    135 /* Callback, registered as an observer, that notifies Python listeners
    136    when an inferior function call has completed. */
    137 
    138 static void
    139 python_on_inferior_call_post (ptid_t thread, CORE_ADDR address)
    140 {
    141   struct cleanup *cleanup;
    142 
    143   cleanup = ensure_python_env (target_gdbarch (), current_language);
    144 
    145   if (emit_inferior_call_event (INFERIOR_CALL_POST, thread, address) < 0)
    146     gdbpy_print_stack ();
    147 
    148   do_cleanups (cleanup);
    149 }
    150 
    151 /* Callback, registered as an observer, that notifies Python listeners
    152    when a part of memory has been modified by user action (eg via a
    153    'set' command). */
    154 
    155 static void
    156 python_on_memory_change (struct inferior *inferior, CORE_ADDR addr, ssize_t len, const bfd_byte *data)
    157 {
    158   struct cleanup *cleanup;
    159 
    160   cleanup = ensure_python_env (target_gdbarch (), current_language);
    161 
    162   if (emit_memory_changed_event (addr, len) < 0)
    163     gdbpy_print_stack ();
    164 
    165   do_cleanups (cleanup);
    166 }
    167 
    168 /* Callback, registered as an observer, that notifies Python listeners
    169    when a register has been modified by user action (eg via a 'set'
    170    command). */
    171 
    172 static void
    173 python_on_register_change (struct frame_info *frame, int regnum)
    174 {
    175   struct cleanup *cleanup;
    176 
    177   cleanup = ensure_python_env (target_gdbarch (), current_language);
    178 
    179   if (emit_register_changed_event (frame, regnum) < 0)
    180     gdbpy_print_stack ();
    181 
    182   do_cleanups (cleanup);
    183 }
    184 
    185 static void
    186 python_inferior_exit (struct inferior *inf)
    187 {
    188   struct cleanup *cleanup;
    189   const LONGEST *exit_code = NULL;
    190 
    191   if (!gdb_python_initialized)
    192     return;
    193 
    194   cleanup = ensure_python_env (target_gdbarch (), current_language);
    195 
    196   if (inf->has_exit_code)
    197     exit_code = &inf->exit_code;
    198 
    199   if (emit_exited_event (exit_code, inf) < 0)
    200     gdbpy_print_stack ();
    201 
    202   do_cleanups (cleanup);
    203 }
    204 
    205 /* Callback used to notify Python listeners about new objfiles loaded in the
    206    inferior.  OBJFILE may be NULL which means that the objfile list has been
    207    cleared (emptied).  */
    208 
    209 static void
    210 python_new_objfile (struct objfile *objfile)
    211 {
    212   struct cleanup *cleanup;
    213 
    214   if (!gdb_python_initialized)
    215     return;
    216 
    217   cleanup = ensure_python_env (objfile != NULL
    218 			       ? get_objfile_arch (objfile)
    219 			       : target_gdbarch (),
    220 			       current_language);
    221 
    222   if (objfile == NULL)
    223     {
    224       if (emit_clear_objfiles_event () < 0)
    225 	gdbpy_print_stack ();
    226     }
    227   else
    228     {
    229       if (emit_new_objfile_event (objfile) < 0)
    230 	gdbpy_print_stack ();
    231     }
    232 
    233   do_cleanups (cleanup);
    234 }
    235 
    236 /* Return a reference to the Python object of type Inferior
    237    representing INFERIOR.  If the object has already been created,
    238    return it and increment the reference count,  otherwise, create it.
    239    Return NULL on failure.  */
    240 PyObject *
    241 inferior_to_inferior_object (struct inferior *inferior)
    242 {
    243   inferior_object *inf_obj;
    244 
    245   inf_obj = inferior_data (inferior, infpy_inf_data_key);
    246   if (!inf_obj)
    247     {
    248       inf_obj = PyObject_New (inferior_object, &inferior_object_type);
    249       if (!inf_obj)
    250 	  return NULL;
    251 
    252       inf_obj->inferior = inferior;
    253       inf_obj->threads = NULL;
    254       inf_obj->nthreads = 0;
    255 
    256       set_inferior_data (inferior, infpy_inf_data_key, inf_obj);
    257 
    258     }
    259   else
    260     Py_INCREF ((PyObject *)inf_obj);
    261 
    262   return (PyObject *) inf_obj;
    263 }
    264 
    265 /* Finds the Python Inferior object for the given PID.  Returns a
    266    reference, or NULL if PID does not match any inferior object. */
    267 
    268 PyObject *
    269 find_inferior_object (int pid)
    270 {
    271   struct inferior *inf = find_inferior_pid (pid);
    272 
    273   if (inf)
    274     return inferior_to_inferior_object (inf);
    275 
    276   return NULL;
    277 }
    278 
    279 thread_object *
    280 find_thread_object (ptid_t ptid)
    281 {
    282   int pid;
    283   struct threadlist_entry *thread;
    284   PyObject *inf_obj;
    285   thread_object *found = NULL;
    286 
    287   pid = ptid_get_pid (ptid);
    288   if (pid == 0)
    289     return NULL;
    290 
    291   inf_obj = find_inferior_object (pid);
    292 
    293   if (! inf_obj)
    294     return NULL;
    295 
    296   for (thread = ((inferior_object *)inf_obj)->threads; thread;
    297        thread = thread->next)
    298     if (ptid_equal (thread->thread_obj->thread->ptid, ptid))
    299       {
    300 	found = thread->thread_obj;
    301 	break;
    302       }
    303 
    304   Py_DECREF (inf_obj);
    305 
    306   if (found)
    307     return found;
    308 
    309   return NULL;
    310 }
    311 
    312 static void
    313 add_thread_object (struct thread_info *tp)
    314 {
    315   struct cleanup *cleanup;
    316   thread_object *thread_obj;
    317   inferior_object *inf_obj;
    318   struct threadlist_entry *entry;
    319 
    320   if (!gdb_python_initialized)
    321     return;
    322 
    323   cleanup = ensure_python_env (python_gdbarch, python_language);
    324 
    325   thread_obj = create_thread_object (tp);
    326   if (!thread_obj)
    327     {
    328       gdbpy_print_stack ();
    329       do_cleanups (cleanup);
    330       return;
    331     }
    332 
    333   inf_obj = (inferior_object *) thread_obj->inf_obj;
    334 
    335   entry = xmalloc (sizeof (struct threadlist_entry));
    336   entry->thread_obj = thread_obj;
    337   entry->next = inf_obj->threads;
    338 
    339   inf_obj->threads = entry;
    340   inf_obj->nthreads++;
    341 
    342   do_cleanups (cleanup);
    343 }
    344 
    345 static void
    346 delete_thread_object (struct thread_info *tp, int ignore)
    347 {
    348   struct cleanup *cleanup;
    349   inferior_object *inf_obj;
    350   struct threadlist_entry **entry, *tmp;
    351 
    352   if (!gdb_python_initialized)
    353     return;
    354 
    355   cleanup = ensure_python_env (python_gdbarch, python_language);
    356 
    357   inf_obj
    358     = (inferior_object *) find_inferior_object (ptid_get_pid (tp->ptid));
    359   if (!inf_obj)
    360     {
    361       do_cleanups (cleanup);
    362       return;
    363     }
    364 
    365   /* Find thread entry in its inferior's thread_list.  */
    366   for (entry = &inf_obj->threads; *entry != NULL; entry =
    367 	 &(*entry)->next)
    368     if ((*entry)->thread_obj->thread == tp)
    369       break;
    370 
    371   if (!*entry)
    372     {
    373       Py_DECREF (inf_obj);
    374       do_cleanups (cleanup);
    375       return;
    376     }
    377 
    378   tmp = *entry;
    379   tmp->thread_obj->thread = NULL;
    380 
    381   *entry = (*entry)->next;
    382   inf_obj->nthreads--;
    383 
    384   Py_DECREF (tmp->thread_obj);
    385   Py_DECREF (inf_obj);
    386   xfree (tmp);
    387 
    388   do_cleanups (cleanup);
    389 }
    390 
    391 static PyObject *
    392 infpy_threads (PyObject *self, PyObject *args)
    393 {
    394   int i;
    395   struct threadlist_entry *entry;
    396   inferior_object *inf_obj = (inferior_object *) self;
    397   PyObject *tuple;
    398   volatile struct gdb_exception except;
    399 
    400   INFPY_REQUIRE_VALID (inf_obj);
    401 
    402   TRY_CATCH (except, RETURN_MASK_ALL)
    403     update_thread_list ();
    404   GDB_PY_HANDLE_EXCEPTION (except);
    405 
    406   tuple = PyTuple_New (inf_obj->nthreads);
    407   if (!tuple)
    408     return NULL;
    409 
    410   for (i = 0, entry = inf_obj->threads; i < inf_obj->nthreads;
    411        i++, entry = entry->next)
    412     {
    413       Py_INCREF (entry->thread_obj);
    414       PyTuple_SET_ITEM (tuple, i, (PyObject *) entry->thread_obj);
    415     }
    416 
    417   return tuple;
    418 }
    419 
    420 static PyObject *
    421 infpy_get_num (PyObject *self, void *closure)
    422 {
    423   inferior_object *inf = (inferior_object *) self;
    424 
    425   INFPY_REQUIRE_VALID (inf);
    426 
    427   return PyLong_FromLong (inf->inferior->num);
    428 }
    429 
    430 static PyObject *
    431 infpy_get_pid (PyObject *self, void *closure)
    432 {
    433   inferior_object *inf = (inferior_object *) self;
    434 
    435   INFPY_REQUIRE_VALID (inf);
    436 
    437   return PyLong_FromLong (inf->inferior->pid);
    438 }
    439 
    440 static PyObject *
    441 infpy_get_was_attached (PyObject *self, void *closure)
    442 {
    443   inferior_object *inf = (inferior_object *) self;
    444 
    445   INFPY_REQUIRE_VALID (inf);
    446   if (inf->inferior->attach_flag)
    447     Py_RETURN_TRUE;
    448   Py_RETURN_FALSE;
    449 }
    450 
    451 static int
    452 build_inferior_list (struct inferior *inf, void *arg)
    453 {
    454   PyObject *list = arg;
    455   PyObject *inferior = inferior_to_inferior_object (inf);
    456   int success = 0;
    457 
    458   if (! inferior)
    459     return 0;
    460 
    461   success = PyList_Append (list, inferior);
    462   Py_DECREF (inferior);
    463 
    464   if (success)
    465     return 1;
    466 
    467   return 0;
    468 }
    469 
    470 /* Implementation of gdb.inferiors () -> (gdb.Inferior, ...).
    471    Returns a tuple of all inferiors.  */
    472 PyObject *
    473 gdbpy_inferiors (PyObject *unused, PyObject *unused2)
    474 {
    475   PyObject *list, *tuple;
    476 
    477   list = PyList_New (0);
    478   if (!list)
    479     return NULL;
    480 
    481   if (iterate_over_inferiors (build_inferior_list, list))
    482     {
    483       Py_DECREF (list);
    484       return NULL;
    485     }
    486 
    487   tuple = PyList_AsTuple (list);
    488   Py_DECREF (list);
    489 
    490   return tuple;
    491 }
    492 
    493 /* Membuf and memory manipulation.  */
    494 
    495 /* Implementation of Inferior.read_memory (address, length).
    496    Returns a Python buffer object with LENGTH bytes of the inferior's
    497    memory at ADDRESS.  Both arguments are integers.  Returns NULL on error,
    498    with a python exception set.  */
    499 static PyObject *
    500 infpy_read_memory (PyObject *self, PyObject *args, PyObject *kw)
    501 {
    502   CORE_ADDR addr, length;
    503   void *buffer = NULL;
    504   membuf_object *membuf_obj;
    505   PyObject *addr_obj, *length_obj, *result;
    506   volatile struct gdb_exception except;
    507   static char *keywords[] = { "address", "length", NULL };
    508 
    509   if (! PyArg_ParseTupleAndKeywords (args, kw, "OO", keywords,
    510 				     &addr_obj, &length_obj))
    511     return NULL;
    512 
    513   if (get_addr_from_python (addr_obj, &addr) < 0
    514       || get_addr_from_python (length_obj, &length) < 0)
    515     return NULL;
    516 
    517   TRY_CATCH (except, RETURN_MASK_ALL)
    518     {
    519       buffer = xmalloc (length);
    520 
    521       read_memory (addr, buffer, length);
    522     }
    523   if (except.reason < 0)
    524     {
    525       xfree (buffer);
    526       GDB_PY_HANDLE_EXCEPTION (except);
    527     }
    528 
    529   membuf_obj = PyObject_New (membuf_object, &membuf_object_type);
    530   if (membuf_obj == NULL)
    531     {
    532       xfree (buffer);
    533       return NULL;
    534     }
    535 
    536   membuf_obj->buffer = buffer;
    537   membuf_obj->addr = addr;
    538   membuf_obj->length = length;
    539 
    540 #ifdef IS_PY3K
    541   result = PyMemoryView_FromObject ((PyObject *) membuf_obj);
    542 #else
    543   result = PyBuffer_FromReadWriteObject ((PyObject *) membuf_obj, 0,
    544 					 Py_END_OF_BUFFER);
    545 #endif
    546   Py_DECREF (membuf_obj);
    547 
    548   return result;
    549 }
    550 
    551 /* Implementation of Inferior.write_memory (address, buffer [, length]).
    552    Writes the contents of BUFFER (a Python object supporting the read
    553    buffer protocol) at ADDRESS in the inferior's memory.  Write LENGTH
    554    bytes from BUFFER, or its entire contents if the argument is not
    555    provided.  The function returns nothing.  Returns NULL on error, with
    556    a python exception set.  */
    557 static PyObject *
    558 infpy_write_memory (PyObject *self, PyObject *args, PyObject *kw)
    559 {
    560   Py_ssize_t buf_len;
    561   const char *buffer;
    562   CORE_ADDR addr, length;
    563   PyObject *addr_obj, *length_obj = NULL;
    564   volatile struct gdb_exception except;
    565   static char *keywords[] = { "address", "buffer", "length", NULL };
    566 #ifdef IS_PY3K
    567   Py_buffer pybuf;
    568 
    569   if (! PyArg_ParseTupleAndKeywords (args, kw, "Os*|O", keywords,
    570 				     &addr_obj, &pybuf,
    571 				     &length_obj))
    572     return NULL;
    573 
    574   buffer = pybuf.buf;
    575   buf_len = pybuf.len;
    576 #else
    577   if (! PyArg_ParseTupleAndKeywords (args, kw, "Os#|O", keywords,
    578 				     &addr_obj, &buffer, &buf_len,
    579 				     &length_obj))
    580     return NULL;
    581 #endif
    582 
    583   if (get_addr_from_python (addr_obj, &addr) < 0)
    584     goto fail;
    585 
    586   if (!length_obj)
    587     length = buf_len;
    588   else if (get_addr_from_python (length_obj, &length) < 0)
    589     goto fail;
    590 
    591   TRY_CATCH (except, RETURN_MASK_ALL)
    592     {
    593       write_memory_with_notification (addr, (gdb_byte *) buffer, length);
    594     }
    595 #ifdef IS_PY3K
    596   PyBuffer_Release (&pybuf);
    597 #endif
    598   GDB_PY_HANDLE_EXCEPTION (except);
    599 
    600   Py_RETURN_NONE;
    601 
    602  fail:
    603 #ifdef IS_PY3K
    604   PyBuffer_Release (&pybuf);
    605 #endif
    606   return NULL;
    607 }
    608 
    609 /* Destructor of Membuf objects.  */
    610 static void
    611 mbpy_dealloc (PyObject *self)
    612 {
    613   xfree (((membuf_object *) self)->buffer);
    614   Py_TYPE (self)->tp_free (self);
    615 }
    616 
    617 /* Return a description of the Membuf object.  */
    618 static PyObject *
    619 mbpy_str (PyObject *self)
    620 {
    621   membuf_object *membuf_obj = (membuf_object *) self;
    622 
    623   return PyString_FromFormat (_("Memory buffer for address %s, \
    624 which is %s bytes long."),
    625 			      paddress (python_gdbarch, membuf_obj->addr),
    626 			      pulongest (membuf_obj->length));
    627 }
    628 
    629 #ifdef IS_PY3K
    630 
    631 static int
    632 get_buffer (PyObject *self, Py_buffer *buf, int flags)
    633 {
    634   membuf_object *membuf_obj = (membuf_object *) self;
    635   int ret;
    636 
    637   ret = PyBuffer_FillInfo (buf, self, membuf_obj->buffer,
    638 			   membuf_obj->length, 0,
    639 			   PyBUF_CONTIG);
    640   buf->format = "c";
    641 
    642   return ret;
    643 }
    644 
    645 #else
    646 
    647 static Py_ssize_t
    648 get_read_buffer (PyObject *self, Py_ssize_t segment, void **ptrptr)
    649 {
    650   membuf_object *membuf_obj = (membuf_object *) self;
    651 
    652   if (segment)
    653     {
    654       PyErr_SetString (PyExc_SystemError,
    655 		       _("The memory buffer supports only one segment."));
    656       return -1;
    657     }
    658 
    659   *ptrptr = membuf_obj->buffer;
    660 
    661   return membuf_obj->length;
    662 }
    663 
    664 static Py_ssize_t
    665 get_write_buffer (PyObject *self, Py_ssize_t segment, void **ptrptr)
    666 {
    667   return get_read_buffer (self, segment, ptrptr);
    668 }
    669 
    670 static Py_ssize_t
    671 get_seg_count (PyObject *self, Py_ssize_t *lenp)
    672 {
    673   if (lenp)
    674     *lenp = ((membuf_object *) self)->length;
    675 
    676   return 1;
    677 }
    678 
    679 static Py_ssize_t
    680 get_char_buffer (PyObject *self, Py_ssize_t segment, char **ptrptr)
    681 {
    682   void *ptr = NULL;
    683   Py_ssize_t ret;
    684 
    685   ret = get_read_buffer (self, segment, &ptr);
    686   *ptrptr = (char *) ptr;
    687 
    688   return ret;
    689 }
    690 
    691 #endif	/* IS_PY3K */
    692 
    693 /* Implementation of
    694    gdb.search_memory (address, length, pattern).  ADDRESS is the
    695    address to start the search.  LENGTH specifies the scope of the
    696    search from ADDRESS.  PATTERN is the pattern to search for (and
    697    must be a Python object supporting the buffer protocol).
    698    Returns a Python Long object holding the address where the pattern
    699    was located, or if the pattern was not found, returns None.  Returns NULL
    700    on error, with a python exception set.  */
    701 static PyObject *
    702 infpy_search_memory (PyObject *self, PyObject *args, PyObject *kw)
    703 {
    704   CORE_ADDR start_addr, length;
    705   static char *keywords[] = { "address", "length", "pattern", NULL };
    706   PyObject *start_addr_obj, *length_obj;
    707   volatile struct gdb_exception except;
    708   Py_ssize_t pattern_size;
    709   const void *buffer;
    710   CORE_ADDR found_addr;
    711   int found = 0;
    712 #ifdef IS_PY3K
    713   Py_buffer pybuf;
    714 
    715   if (! PyArg_ParseTupleAndKeywords (args, kw, "OOs*", keywords,
    716 				     &start_addr_obj, &length_obj,
    717 				     &pybuf))
    718     return NULL;
    719 
    720   buffer = pybuf.buf;
    721   pattern_size = pybuf.len;
    722 #else
    723   PyObject *pattern;
    724 
    725   if (! PyArg_ParseTupleAndKeywords (args, kw, "OOO", keywords,
    726  				     &start_addr_obj, &length_obj,
    727 				     &pattern))
    728      return NULL;
    729 
    730   if (!PyObject_CheckReadBuffer (pattern))
    731     {
    732       PyErr_SetString (PyExc_RuntimeError,
    733 		       _("The pattern is not a Python buffer."));
    734 
    735       return NULL;
    736     }
    737 
    738   if (PyObject_AsReadBuffer (pattern, &buffer, &pattern_size) == -1)
    739     return NULL;
    740 #endif
    741 
    742   if (get_addr_from_python (start_addr_obj, &start_addr) < 0)
    743     goto fail;
    744 
    745   if (get_addr_from_python (length_obj, &length) < 0)
    746     goto fail;
    747 
    748   if (!length)
    749     {
    750       PyErr_SetString (PyExc_ValueError,
    751 		       _("Search range is empty."));
    752       goto fail;
    753     }
    754   /* Watch for overflows.  */
    755   else if (length > CORE_ADDR_MAX
    756 	   || (start_addr + length - 1) < start_addr)
    757     {
    758       PyErr_SetString (PyExc_ValueError,
    759 		       _("The search range is too large."));
    760       goto fail;
    761     }
    762 
    763   TRY_CATCH (except, RETURN_MASK_ALL)
    764     {
    765       found = target_search_memory (start_addr, length,
    766 				    buffer, pattern_size,
    767 				    &found_addr);
    768     }
    769 #ifdef IS_PY3K
    770   PyBuffer_Release (&pybuf);
    771 #endif
    772   GDB_PY_HANDLE_EXCEPTION (except);
    773 
    774   if (found)
    775     return PyLong_FromLong (found_addr);
    776   else
    777     Py_RETURN_NONE;
    778 
    779  fail:
    780 #ifdef IS_PY3K
    781   PyBuffer_Release (&pybuf);
    782 #endif
    783   return NULL;
    784 }
    785 
    786 /* Implementation of gdb.Inferior.is_valid (self) -> Boolean.
    787    Returns True if this inferior object still exists in GDB.  */
    788 
    789 static PyObject *
    790 infpy_is_valid (PyObject *self, PyObject *args)
    791 {
    792   inferior_object *inf = (inferior_object *) self;
    793 
    794   if (! inf->inferior)
    795     Py_RETURN_FALSE;
    796 
    797   Py_RETURN_TRUE;
    798 }
    799 
    800 static void
    801 infpy_dealloc (PyObject *obj)
    802 {
    803   inferior_object *inf_obj = (inferior_object *) obj;
    804   struct inferior *inf = inf_obj->inferior;
    805 
    806   if (! inf)
    807     return;
    808 
    809   set_inferior_data (inf, infpy_inf_data_key, NULL);
    810 }
    811 
    812 /* Clear the INFERIOR pointer in an Inferior object and clear the
    813    thread list.  */
    814 static void
    815 py_free_inferior (struct inferior *inf, void *datum)
    816 {
    817 
    818   struct cleanup *cleanup;
    819   inferior_object *inf_obj = datum;
    820   struct threadlist_entry *th_entry, *th_tmp;
    821 
    822   if (!gdb_python_initialized)
    823     return;
    824 
    825   cleanup = ensure_python_env (python_gdbarch, python_language);
    826 
    827   inf_obj->inferior = NULL;
    828 
    829   /* Deallocate threads list.  */
    830   for (th_entry = inf_obj->threads; th_entry != NULL;)
    831     {
    832       Py_DECREF (th_entry->thread_obj);
    833 
    834       th_tmp = th_entry;
    835       th_entry = th_entry->next;
    836       xfree (th_tmp);
    837     }
    838 
    839   inf_obj->nthreads = 0;
    840 
    841   Py_DECREF ((PyObject *) inf_obj);
    842   do_cleanups (cleanup);
    843 }
    844 
    845 /* Implementation of gdb.selected_inferior() -> gdb.Inferior.
    846    Returns the current inferior object.  */
    847 
    848 PyObject *
    849 gdbpy_selected_inferior (PyObject *self, PyObject *args)
    850 {
    851   return inferior_to_inferior_object (current_inferior ());
    852 }
    853 
    854 int
    855 gdbpy_initialize_inferior (void)
    856 {
    857   if (PyType_Ready (&inferior_object_type) < 0)
    858     return -1;
    859 
    860   if (gdb_pymodule_addobject (gdb_module, "Inferior",
    861 			      (PyObject *) &inferior_object_type) < 0)
    862     return -1;
    863 
    864   infpy_inf_data_key =
    865     register_inferior_data_with_cleanup (NULL, py_free_inferior);
    866 
    867   observer_attach_new_thread (add_thread_object);
    868   observer_attach_thread_exit (delete_thread_object);
    869   observer_attach_normal_stop (python_on_normal_stop);
    870   observer_attach_target_resumed (python_on_resume);
    871   observer_attach_inferior_call_pre (python_on_inferior_call_pre);
    872   observer_attach_inferior_call_post (python_on_inferior_call_post);
    873   observer_attach_memory_changed (python_on_memory_change);
    874   observer_attach_register_changed (python_on_register_change);
    875   observer_attach_inferior_exit (python_inferior_exit);
    876   observer_attach_new_objfile (python_new_objfile);
    877 
    878   membuf_object_type.tp_new = PyType_GenericNew;
    879   if (PyType_Ready (&membuf_object_type) < 0)
    880     return -1;
    881 
    882   return gdb_pymodule_addobject (gdb_module, "Membuf", (PyObject *)
    883 				 &membuf_object_type);
    884 }
    885 
    886 static PyGetSetDef inferior_object_getset[] =
    887 {
    888   { "num", infpy_get_num, NULL, "ID of inferior, as assigned by GDB.", NULL },
    889   { "pid", infpy_get_pid, NULL, "PID of inferior, as assigned by the OS.",
    890     NULL },
    891   { "was_attached", infpy_get_was_attached, NULL,
    892     "True if the inferior was created using 'attach'.", NULL },
    893   { NULL }
    894 };
    895 
    896 static PyMethodDef inferior_object_methods[] =
    897 {
    898   { "is_valid", infpy_is_valid, METH_NOARGS,
    899     "is_valid () -> Boolean.\n\
    900 Return true if this inferior is valid, false if not." },
    901   { "threads", infpy_threads, METH_NOARGS,
    902     "Return all the threads of this inferior." },
    903   { "read_memory", (PyCFunction) infpy_read_memory,
    904     METH_VARARGS | METH_KEYWORDS,
    905     "read_memory (address, length) -> buffer\n\
    906 Return a buffer object for reading from the inferior's memory." },
    907   { "write_memory", (PyCFunction) infpy_write_memory,
    908     METH_VARARGS | METH_KEYWORDS,
    909     "write_memory (address, buffer [, length])\n\
    910 Write the given buffer object to the inferior's memory." },
    911   { "search_memory", (PyCFunction) infpy_search_memory,
    912     METH_VARARGS | METH_KEYWORDS,
    913     "search_memory (address, length, pattern) -> long\n\
    914 Return a long with the address of a match, or None." },
    915   { NULL }
    916 };
    917 
    918 static PyTypeObject inferior_object_type =
    919 {
    920   PyVarObject_HEAD_INIT (NULL, 0)
    921   "gdb.Inferior",		  /* tp_name */
    922   sizeof (inferior_object),	  /* tp_basicsize */
    923   0,				  /* tp_itemsize */
    924   infpy_dealloc,		  /* tp_dealloc */
    925   0,				  /* tp_print */
    926   0,				  /* tp_getattr */
    927   0,				  /* tp_setattr */
    928   0,				  /* tp_compare */
    929   0,				  /* tp_repr */
    930   0,				  /* tp_as_number */
    931   0,				  /* tp_as_sequence */
    932   0,				  /* tp_as_mapping */
    933   0,				  /* tp_hash  */
    934   0,				  /* tp_call */
    935   0,				  /* tp_str */
    936   0,				  /* tp_getattro */
    937   0,				  /* tp_setattro */
    938   0,				  /* tp_as_buffer */
    939   Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_ITER,  /* tp_flags */
    940   "GDB inferior object",	  /* tp_doc */
    941   0,				  /* tp_traverse */
    942   0,				  /* tp_clear */
    943   0,				  /* tp_richcompare */
    944   0,				  /* tp_weaklistoffset */
    945   0,				  /* tp_iter */
    946   0,				  /* tp_iternext */
    947   inferior_object_methods,	  /* tp_methods */
    948   0,				  /* tp_members */
    949   inferior_object_getset,	  /* tp_getset */
    950   0,				  /* tp_base */
    951   0,				  /* tp_dict */
    952   0,				  /* tp_descr_get */
    953   0,				  /* tp_descr_set */
    954   0,				  /* tp_dictoffset */
    955   0,				  /* tp_init */
    956   0				  /* tp_alloc */
    957 };
    958 
    959 #ifdef IS_PY3K
    960 
    961 static PyBufferProcs buffer_procs =
    962 {
    963   get_buffer
    964 };
    965 
    966 #else
    967 
    968 /* Python doesn't provide a decent way to get compatibility here.  */
    969 #if HAVE_LIBPYTHON2_4
    970 #define CHARBUFFERPROC_NAME getcharbufferproc
    971 #else
    972 #define CHARBUFFERPROC_NAME charbufferproc
    973 #endif
    974 
    975 static PyBufferProcs buffer_procs = {
    976   get_read_buffer,
    977   get_write_buffer,
    978   get_seg_count,
    979   /* The cast here works around a difference between Python 2.4 and
    980      Python 2.5.  */
    981   (CHARBUFFERPROC_NAME) get_char_buffer
    982 };
    983 #endif	/* IS_PY3K */
    984 
    985 static PyTypeObject membuf_object_type = {
    986   PyVarObject_HEAD_INIT (NULL, 0)
    987   "gdb.Membuf",			  /*tp_name*/
    988   sizeof (membuf_object),	  /*tp_basicsize*/
    989   0,				  /*tp_itemsize*/
    990   mbpy_dealloc,			  /*tp_dealloc*/
    991   0,				  /*tp_print*/
    992   0,				  /*tp_getattr*/
    993   0,				  /*tp_setattr*/
    994   0,				  /*tp_compare*/
    995   0,				  /*tp_repr*/
    996   0,				  /*tp_as_number*/
    997   0,				  /*tp_as_sequence*/
    998   0,				  /*tp_as_mapping*/
    999   0,				  /*tp_hash */
   1000   0,				  /*tp_call*/
   1001   mbpy_str,			  /*tp_str*/
   1002   0,				  /*tp_getattro*/
   1003   0,				  /*tp_setattro*/
   1004   &buffer_procs,		  /*tp_as_buffer*/
   1005   Py_TPFLAGS_DEFAULT,		  /*tp_flags*/
   1006   "GDB memory buffer object", 	  /*tp_doc*/
   1007   0,				  /* tp_traverse */
   1008   0,				  /* tp_clear */
   1009   0,				  /* tp_richcompare */
   1010   0,				  /* tp_weaklistoffset */
   1011   0,				  /* tp_iter */
   1012   0,				  /* tp_iternext */
   1013   0,				  /* tp_methods */
   1014   0,				  /* tp_members */
   1015   0,				  /* tp_getset */
   1016   0,				  /* tp_base */
   1017   0,				  /* tp_dict */
   1018   0,				  /* tp_descr_get */
   1019   0,				  /* tp_descr_set */
   1020   0,				  /* tp_dictoffset */
   1021   0,				  /* tp_init */
   1022   0,				  /* tp_alloc */
   1023 };
   1024