gdb/python/py-inferior.c

   1 /* Python interface to inferiors.
   2
   3    Copyright (C) 2009-2017 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 extern 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 extern 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   enum gdb_signal stop_signal;
  85
  86   if (!gdb_python_initialized)
  87     return;
  88
  89   if (!find_thread_ptid (inferior_ptid))
  90       return;
  91
  92   stop_signal = inferior_thread ()->suspend.stop_signal;
  93
  94   gdbpy_enter enter_py (get_current_arch (), current_language);
  95
  96   if (emit_stop_event (bs, stop_signal) < 0)
  97     gdbpy_print_stack ();
  98 }
  99
 100 static void
 101 python_on_resume (ptid_t ptid)
 102 {
 103   if (!gdb_python_initialized)
 104     return;
 105
 106   gdbpy_enter enter_py (target_gdbarch (), current_language);
 107
 108   if (emit_continue_event (ptid) < 0)
 109     gdbpy_print_stack ();
 110 }
 111
 112 /* Callback, registered as an observer, that notifies Python listeners
 113    when an inferior function call is about to be made. */
 114
 115 static void
 116 python_on_inferior_call_pre (ptid_t thread, CORE_ADDR address)
 117 {
 118   gdbpy_enter enter_py (target_gdbarch (), current_language);
 119
 120   if (emit_inferior_call_event (INFERIOR_CALL_PRE, thread, address) < 0)
 121     gdbpy_print_stack ();
 122 }
 123
 124 /* Callback, registered as an observer, that notifies Python listeners
 125    when an inferior function call has completed. */
 126
 127 static void
 128 python_on_inferior_call_post (ptid_t thread, CORE_ADDR address)
 129 {
 130   gdbpy_enter enter_py (target_gdbarch (), current_language);
 131
 132   if (emit_inferior_call_event (INFERIOR_CALL_POST, thread, address) < 0)
 133     gdbpy_print_stack ();
 134 }
 135
 136 /* Callback, registered as an observer, that notifies Python listeners
 137    when a part of memory has been modified by user action (eg via a
 138    'set' command). */
 139
 140 static void
 141 python_on_memory_change (struct inferior *inferior, CORE_ADDR addr, ssize_t len, const bfd_byte *data)
 142 {
 143   gdbpy_enter enter_py (target_gdbarch (), current_language);
 144
 145   if (emit_memory_changed_event (addr, len) < 0)
 146     gdbpy_print_stack ();
 147 }
 148
 149 /* Callback, registered as an observer, that notifies Python listeners
 150    when a register has been modified by user action (eg via a 'set'
 151    command). */
 152
 153 static void
 154 python_on_register_change (struct frame_info *frame, int regnum)
 155 {
 156   gdbpy_enter enter_py (target_gdbarch (), current_language);
 157
 158   if (emit_register_changed_event (frame, regnum) < 0)
 159     gdbpy_print_stack ();
 160 }
 161
 162 static void
 163 python_inferior_exit (struct inferior *inf)
 164 {
 165   const LONGEST *exit_code = NULL;
 166
 167   if (!gdb_python_initialized)
 168     return;
 169
 170   gdbpy_enter enter_py (target_gdbarch (), current_language);
 171
 172   if (inf->has_exit_code)
 173     exit_code = &inf->exit_code;
 174
 175   if (emit_exited_event (exit_code, inf) < 0)
 176     gdbpy_print_stack ();
 177 }
 178
 179 /* Callback used to notify Python listeners about new objfiles loaded in the
 180    inferior.  OBJFILE may be NULL which means that the objfile list has been
 181    cleared (emptied).  */
 182
 183 static void
 184 python_new_objfile (struct objfile *objfile)
 185 {
 186   if (!gdb_python_initialized)
 187     return;
 188
 189   gdbpy_enter enter_py (objfile != NULL
 190                         ? get_objfile_arch (objfile)
 191                         : target_gdbarch (),
 192                         current_language);
 193
 194   if (objfile == NULL)
 195     {
 196       if (emit_clear_objfiles_event () < 0)
 197         gdbpy_print_stack ();
 198     }
 199   else
 200     {
 201       if (emit_new_objfile_event (objfile) < 0)
 202         gdbpy_print_stack ();
 203     }
 204 }
 205
 206 /* Return a reference to the Python object of type Inferior
 207    representing INFERIOR.  If the object has already been created,
 208    return it and increment the reference count,  otherwise, create it.
 209    Return NULL on failure.  */
 210 PyObject *
 211 inferior_to_inferior_object (struct inferior *inferior)
 212 {
 213   inferior_object *inf_obj;
 214
 215   inf_obj = (inferior_object *) inferior_data (inferior, infpy_inf_data_key);
 216   if (!inf_obj)
 217     {
 218       inf_obj = PyObject_New (inferior_object, &inferior_object_type);
 219       if (!inf_obj)
 220           return NULL;
 221
 222       inf_obj->inferior = inferior;
 223       inf_obj->threads = NULL;
 224       inf_obj->nthreads = 0;
 225
 226       set_inferior_data (inferior, infpy_inf_data_key, inf_obj);
 227
 228     }
 229   else
 230     Py_INCREF ((PyObject *)inf_obj);
 231
 232   return (PyObject *) inf_obj;
 233 }
 234
 235 /* Finds the Python Inferior object for the given PID.  Returns a
 236    reference, or NULL if PID does not match any inferior object. */
 237
 238 PyObject *
 239 find_inferior_object (int pid)
 240 {
 241   struct inferior *inf = find_inferior_pid (pid);
 242
 243   if (inf)
 244     return inferior_to_inferior_object (inf);
 245
 246   return NULL;
 247 }
 248
 249 thread_object *
 250 find_thread_object (ptid_t ptid)
 251 {
 252   int pid;
 253   struct threadlist_entry *thread;
 254
 255   pid = ptid_get_pid (ptid);
 256   if (pid == 0)
 257     return NULL;
 258
 259   gdbpy_ref<> inf_obj (find_inferior_object (pid));
 260   if (inf_obj == NULL)
 261     return NULL;
 262
 263   for (thread = ((inferior_object *)(inf_obj.get ()))->threads; thread;
 264        thread = thread->next)
 265     if (ptid_equal (thread->thread_obj->thread->ptid, ptid))
 266       return thread->thread_obj;
 267
 268   return NULL;
 269 }
 270
 271 static void
 272 add_thread_object (struct thread_info *tp)
 273 {
 274   thread_object *thread_obj;
 275   inferior_object *inf_obj;
 276   struct threadlist_entry *entry;
 277
 278   if (!gdb_python_initialized)
 279     return;
 280
 281   gdbpy_enter enter_py (python_gdbarch, python_language);
 282
 283   thread_obj = create_thread_object (tp);
 284   if (!thread_obj)
 285     {
 286       gdbpy_print_stack ();
 287       return;
 288     }
 289
 290   inf_obj = (inferior_object *) thread_obj->inf_obj;
 291
 292   entry = XNEW (struct threadlist_entry);
 293   entry->thread_obj = thread_obj;
 294   entry->next = inf_obj->threads;
 295
 296   inf_obj->threads = entry;
 297   inf_obj->nthreads++;
 298 }
 299
 300 static void
 301 delete_thread_object (struct thread_info *tp, int ignore)
 302 {
 303   struct threadlist_entry **entry, *tmp;
 304
 305   if (!gdb_python_initialized)
 306     return;
 307
 308   gdbpy_enter enter_py (python_gdbarch, python_language);
 309
 310   gdbpy_ref<inferior_object> inf_obj
 311     ((inferior_object *) find_inferior_object (ptid_get_pid (tp->ptid)));
 312   if (inf_obj == NULL)
 313     return;
 314
 315   /* Find thread entry in its inferior's thread_list.  */
 316   for (entry = &inf_obj->threads; *entry != NULL; entry =
 317          &(*entry)->next)
 318     if ((*entry)->thread_obj->thread == tp)
 319       break;
 320
 321   if (!*entry)
 322     return;
 323
 324   tmp = *entry;
 325   tmp->thread_obj->thread = NULL;
 326
 327   *entry = (*entry)->next;
 328   inf_obj->nthreads--;
 329
 330   Py_DECREF (tmp->thread_obj);
 331   xfree (tmp);
 332 }
 333
 334 static PyObject *
 335 infpy_threads (PyObject *self, PyObject *args)
 336 {
 337   int i;
 338   struct threadlist_entry *entry;
 339   inferior_object *inf_obj = (inferior_object *) self;
 340   PyObject *tuple;
 341
 342   INFPY_REQUIRE_VALID (inf_obj);
 343
 344   TRY
 345     {
 346       update_thread_list ();
 347     }
 348   CATCH (except, RETURN_MASK_ALL)
 349     {
 350       GDB_PY_HANDLE_EXCEPTION (except);
 351     }
 352   END_CATCH
 353
 354   tuple = PyTuple_New (inf_obj->nthreads);
 355   if (!tuple)
 356     return NULL;
 357
 358   for (i = 0, entry = inf_obj->threads; i < inf_obj->nthreads;
 359        i++, entry = entry->next)
 360     {
 361       Py_INCREF (entry->thread_obj);
 362       PyTuple_SET_ITEM (tuple, i, (PyObject *) entry->thread_obj);
 363     }
 364
 365   return tuple;
 366 }
 367
 368 static PyObject *
 369 infpy_get_num (PyObject *self, void *closure)
 370 {
 371   inferior_object *inf = (inferior_object *) self;
 372
 373   INFPY_REQUIRE_VALID (inf);
 374
 375   return PyLong_FromLong (inf->inferior->num);
 376 }
 377
 378 static PyObject *
 379 infpy_get_pid (PyObject *self, void *closure)
 380 {
 381   inferior_object *inf = (inferior_object *) self;
 382
 383   INFPY_REQUIRE_VALID (inf);
 384
 385   return PyLong_FromLong (inf->inferior->pid);
 386 }
 387
 388 static PyObject *
 389 infpy_get_was_attached (PyObject *self, void *closure)
 390 {
 391   inferior_object *inf = (inferior_object *) self;
 392
 393   INFPY_REQUIRE_VALID (inf);
 394   if (inf->inferior->attach_flag)
 395     Py_RETURN_TRUE;
 396   Py_RETURN_FALSE;
 397 }
 398
 399 static int
 400 build_inferior_list (struct inferior *inf, void *arg)
 401 {
 402   PyObject *list = (PyObject *) arg;
 403   gdbpy_ref<> inferior (inferior_to_inferior_object (inf));
 404
 405   if (inferior  == NULL)
 406     return 0;
 407
 408   return PyList_Append (list, inferior.get ()) ? 1 : 0;
 409 }
 410
 411 /* Implementation of gdb.inferiors () -> (gdb.Inferior, ...).
 412    Returns a tuple of all inferiors.  */
 413 PyObject *
 414 gdbpy_inferiors (PyObject *unused, PyObject *unused2)
 415 {
 416   gdbpy_ref<> list (PyList_New (0));
 417   if (list == NULL)
 418     return NULL;
 419
 420   if (iterate_over_inferiors (build_inferior_list, list.get ()))
 421     return NULL;
 422
 423   return PyList_AsTuple (list.get ());
 424 }
 425
 426 /* Membuf and memory manipulation.  */
 427
 428 /* Implementation of Inferior.read_memory (address, length).
 429    Returns a Python buffer object with LENGTH bytes of the inferior's
 430    memory at ADDRESS.  Both arguments are integers.  Returns NULL on error,
 431    with a python exception set.  */
 432 static PyObject *
 433 infpy_read_memory (PyObject *self, PyObject *args, PyObject *kw)
 434 {
 435   CORE_ADDR addr, length;
 436   gdb_byte *buffer = NULL;
 437   PyObject *addr_obj, *length_obj, *result;
 438   static char *keywords[] = { "address", "length", NULL };
 439
 440   if (! PyArg_ParseTupleAndKeywords (args, kw, "OO", keywords,
 441                                      &addr_obj, &length_obj))
 442     return NULL;
 443
 444   if (get_addr_from_python (addr_obj, &addr) < 0
 445       || get_addr_from_python (length_obj, &length) < 0)
 446     return NULL;
 447
 448   TRY
 449     {
 450       buffer = (gdb_byte *) xmalloc (length);
 451
 452       read_memory (addr, buffer, length);
 453     }
 454   CATCH (except, RETURN_MASK_ALL)
 455     {
 456       xfree (buffer);
 457       GDB_PY_HANDLE_EXCEPTION (except);
 458     }
 459   END_CATCH
 460
 461   gdbpy_ref<membuf_object> membuf_obj (PyObject_New (membuf_object,
 462                                                      &membuf_object_type));
 463   if (membuf_obj == NULL)
 464     {
 465       xfree (buffer);
 466       return NULL;
 467     }
 468
 469   membuf_obj->buffer = buffer;
 470   membuf_obj->addr = addr;
 471   membuf_obj->length = length;
 472
 473 #ifdef IS_PY3K
 474   result = PyMemoryView_FromObject ((PyObject *) membuf_obj.get ());
 475 #else
 476   result = PyBuffer_FromReadWriteObject ((PyObject *) membuf_obj.get (), 0,
 477                                          Py_END_OF_BUFFER);
 478 #endif
 479
 480   return result;
 481 }
 482
 483 /* Implementation of Inferior.write_memory (address, buffer [, length]).
 484    Writes the contents of BUFFER (a Python object supporting the read
 485    buffer protocol) at ADDRESS in the inferior's memory.  Write LENGTH
 486    bytes from BUFFER, or its entire contents if the argument is not
 487    provided.  The function returns nothing.  Returns NULL on error, with
 488    a python exception set.  */
 489 static PyObject *
 490 infpy_write_memory (PyObject *self, PyObject *args, PyObject *kw)
 491 {
 492   struct gdb_exception except = exception_none;
 493   Py_ssize_t buf_len;
 494   const gdb_byte *buffer;
 495   CORE_ADDR addr, length;
 496   PyObject *addr_obj, *length_obj = NULL;
 497   static char *keywords[] = { "address", "buffer", "length", NULL };
 498 #ifdef IS_PY3K
 499   Py_buffer pybuf;
 500
 501   if (! PyArg_ParseTupleAndKeywords (args, kw, "Os*|O", keywords,
 502                                      &addr_obj, &pybuf,
 503                                      &length_obj))
 504     return NULL;
 505
 506   buffer = (const gdb_byte *) pybuf.buf;
 507   buf_len = pybuf.len;
 508 #else
 509   if (! PyArg_ParseTupleAndKeywords (args, kw, "Os#|O", keywords,
 510                                      &addr_obj, &buffer, &buf_len,
 511                                      &length_obj))
 512     return NULL;
 513
 514   buffer = (const gdb_byte *) buffer;
 515 #endif
 516
 517   if (get_addr_from_python (addr_obj, &addr) < 0)
 518     goto fail;
 519
 520   if (!length_obj)
 521     length = buf_len;
 522   else if (get_addr_from_python (length_obj, &length) < 0)
 523     goto fail;
 524
 525   TRY
 526     {
 527       write_memory_with_notification (addr, buffer, length);
 528     }
 529   CATCH (ex, RETURN_MASK_ALL)
 530     {
 531       except = ex;
 532     }
 533   END_CATCH
 534
 535 #ifdef IS_PY3K
 536   PyBuffer_Release (&pybuf);
 537 #endif
 538   GDB_PY_HANDLE_EXCEPTION (except);
 539
 540   Py_RETURN_NONE;
 541
 542  fail:
 543 #ifdef IS_PY3K
 544   PyBuffer_Release (&pybuf);
 545 #endif
 546   return NULL;
 547 }
 548
 549 /* Destructor of Membuf objects.  */
 550 static void
 551 mbpy_dealloc (PyObject *self)
 552 {
 553   xfree (((membuf_object *) self)->buffer);
 554   Py_TYPE (self)->tp_free (self);
 555 }
 556
 557 /* Return a description of the Membuf object.  */
 558 static PyObject *
 559 mbpy_str (PyObject *self)
 560 {
 561   membuf_object *membuf_obj = (membuf_object *) self;
 562
 563   return PyString_FromFormat (_("Memory buffer for address %s, \
 564 which is %s bytes long."),
 565                               paddress (python_gdbarch, membuf_obj->addr),
 566                               pulongest (membuf_obj->length));
 567 }
 568
 569 #ifdef IS_PY3K
 570
 571 static int
 572 get_buffer (PyObject *self, Py_buffer *buf, int flags)
 573 {
 574   membuf_object *membuf_obj = (membuf_object *) self;
 575   int ret;
 576
 577   ret = PyBuffer_FillInfo (buf, self, membuf_obj->buffer,
 578                            membuf_obj->length, 0,
 579                            PyBUF_CONTIG);
 580   buf->format = "c";
 581
 582   return ret;
 583 }
 584
 585 #else
 586
 587 static Py_ssize_t
 588 get_read_buffer (PyObject *self, Py_ssize_t segment, void **ptrptr)
 589 {
 590   membuf_object *membuf_obj = (membuf_object *) self;
 591
 592   if (segment)
 593     {
 594       PyErr_SetString (PyExc_SystemError,
 595                        _("The memory buffer supports only one segment."));
 596       return -1;
 597     }
 598
 599   *ptrptr = membuf_obj->buffer;
 600
 601   return membuf_obj->length;
 602 }
 603
 604 static Py_ssize_t
 605 get_write_buffer (PyObject *self, Py_ssize_t segment, void **ptrptr)
 606 {
 607   return get_read_buffer (self, segment, ptrptr);
 608 }
 609
 610 static Py_ssize_t
 611 get_seg_count (PyObject *self, Py_ssize_t *lenp)
 612 {
 613   if (lenp)
 614     *lenp = ((membuf_object *) self)->length;
 615
 616   return 1;
 617 }
 618
 619 static Py_ssize_t
 620 get_char_buffer (PyObject *self, Py_ssize_t segment, char **ptrptr)
 621 {
 622   void *ptr = NULL;
 623   Py_ssize_t ret;
 624
 625   ret = get_read_buffer (self, segment, &ptr);
 626   *ptrptr = (char *) ptr;
 627
 628   return ret;
 629 }
 630
 631 #endif  /* IS_PY3K */
 632
 633 /* Implementation of
 634    gdb.search_memory (address, length, pattern).  ADDRESS is the
 635    address to start the search.  LENGTH specifies the scope of the
 636    search from ADDRESS.  PATTERN is the pattern to search for (and
 637    must be a Python object supporting the buffer protocol).
 638    Returns a Python Long object holding the address where the pattern
 639    was located, or if the pattern was not found, returns None.  Returns NULL
 640    on error, with a python exception set.  */
 641 static PyObject *
 642 infpy_search_memory (PyObject *self, PyObject *args, PyObject *kw)
 643 {
 644   struct gdb_exception except = exception_none;
 645   CORE_ADDR start_addr, length;
 646   static char *keywords[] = { "address", "length", "pattern", NULL };
 647   PyObject *start_addr_obj, *length_obj;
 648   Py_ssize_t pattern_size;
 649   const gdb_byte *buffer;
 650   CORE_ADDR found_addr;
 651   int found = 0;
 652 #ifdef IS_PY3K
 653   Py_buffer pybuf;
 654
 655   if (! PyArg_ParseTupleAndKeywords (args, kw, "OOs*", keywords,
 656                                      &start_addr_obj, &length_obj,
 657                                      &pybuf))
 658     return NULL;
 659
 660   buffer = (const gdb_byte *) pybuf.buf;
 661   pattern_size = pybuf.len;
 662 #else
 663   PyObject *pattern;
 664   const void *vbuffer;
 665
 666   if (! PyArg_ParseTupleAndKeywords (args, kw, "OOO", keywords,
 667                                      &start_addr_obj, &length_obj,
 668                                      &pattern))
 669      return NULL;
 670
 671   if (!PyObject_CheckReadBuffer (pattern))
 672     {
 673       PyErr_SetString (PyExc_RuntimeError,
 674                        _("The pattern is not a Python buffer."));
 675
 676       return NULL;
 677     }
 678
 679   if (PyObject_AsReadBuffer (pattern, &vbuffer, &pattern_size) == -1)
 680     return NULL;
 681
 682   buffer = (const gdb_byte *) vbuffer;
 683 #endif
 684
 685   if (get_addr_from_python (start_addr_obj, &start_addr) < 0)
 686     goto fail;
 687
 688   if (get_addr_from_python (length_obj, &length) < 0)
 689     goto fail;
 690
 691   if (!length)
 692     {
 693       PyErr_SetString (PyExc_ValueError,
 694                        _("Search range is empty."));
 695       goto fail;
 696     }
 697   /* Watch for overflows.  */
 698   else if (length > CORE_ADDR_MAX
 699            || (start_addr + length - 1) < start_addr)
 700     {
 701       PyErr_SetString (PyExc_ValueError,
 702                        _("The search range is too large."));
 703       goto fail;
 704     }
 705
 706   TRY
 707     {
 708       found = target_search_memory (start_addr, length,
 709                                     buffer, pattern_size,
 710                                     &found_addr);
 711     }
 712   CATCH (ex, RETURN_MASK_ALL)
 713     {
 714       except = ex;
 715     }
 716   END_CATCH
 717
 718 #ifdef IS_PY3K
 719   PyBuffer_Release (&pybuf);
 720 #endif
 721   GDB_PY_HANDLE_EXCEPTION (except);
 722
 723   if (found)
 724     return PyLong_FromLong (found_addr);
 725   else
 726     Py_RETURN_NONE;
 727
 728  fail:
 729 #ifdef IS_PY3K
 730   PyBuffer_Release (&pybuf);
 731 #endif
 732   return NULL;
 733 }
 734
 735 /* Implementation of gdb.Inferior.is_valid (self) -> Boolean.
 736    Returns True if this inferior object still exists in GDB.  */
 737
 738 static PyObject *
 739 infpy_is_valid (PyObject *self, PyObject *args)
 740 {
 741   inferior_object *inf = (inferior_object *) self;
 742
 743   if (! inf->inferior)
 744     Py_RETURN_FALSE;
 745
 746   Py_RETURN_TRUE;
 747 }
 748
 749 static void
 750 infpy_dealloc (PyObject *obj)
 751 {
 752   inferior_object *inf_obj = (inferior_object *) obj;
 753   struct inferior *inf = inf_obj->inferior;
 754
 755   if (! inf)
 756     return;
 757
 758   set_inferior_data (inf, infpy_inf_data_key, NULL);
 759 }
 760
 761 /* Clear the INFERIOR pointer in an Inferior object and clear the
 762    thread list.  */
 763 static void
 764 py_free_inferior (struct inferior *inf, void *datum)
 765 {
 766   gdbpy_ref<inferior_object> inf_obj ((inferior_object *) datum);
 767   struct threadlist_entry *th_entry, *th_tmp;
 768
 769   if (!gdb_python_initialized)
 770     return;
 771
 772   gdbpy_enter enter_py (python_gdbarch, python_language);
 773
 774   inf_obj->inferior = NULL;
 775
 776   /* Deallocate threads list.  */
 777   for (th_entry = inf_obj->threads; th_entry != NULL;)
 778     {
 779       Py_DECREF (th_entry->thread_obj);
 780
 781       th_tmp = th_entry;
 782       th_entry = th_entry->next;
 783       xfree (th_tmp);
 784     }
 785
 786   inf_obj->nthreads = 0;
 787 }
 788
 789 /* Implementation of gdb.selected_inferior() -> gdb.Inferior.
 790    Returns the current inferior object.  */
 791
 792 PyObject *
 793 gdbpy_selected_inferior (PyObject *self, PyObject *args)
 794 {
 795   return inferior_to_inferior_object (current_inferior ());
 796 }
 797
 798 int
 799 gdbpy_initialize_inferior (void)
 800 {
 801   if (PyType_Ready (&inferior_object_type) < 0)
 802     return -1;
 803
 804   if (gdb_pymodule_addobject (gdb_module, "Inferior",
 805                               (PyObject *) &inferior_object_type) < 0)
 806     return -1;
 807
 808   infpy_inf_data_key =
 809     register_inferior_data_with_cleanup (NULL, py_free_inferior);
 810
 811   observer_attach_new_thread (add_thread_object);
 812   observer_attach_thread_exit (delete_thread_object);
 813   observer_attach_normal_stop (python_on_normal_stop);
 814   observer_attach_target_resumed (python_on_resume);
 815   observer_attach_inferior_call_pre (python_on_inferior_call_pre);
 816   observer_attach_inferior_call_post (python_on_inferior_call_post);
 817   observer_attach_memory_changed (python_on_memory_change);
 818   observer_attach_register_changed (python_on_register_change);
 819   observer_attach_inferior_exit (python_inferior_exit);
 820   observer_attach_new_objfile (python_new_objfile);
 821
 822   membuf_object_type.tp_new = PyType_GenericNew;
 823   if (PyType_Ready (&membuf_object_type) < 0)
 824     return -1;
 825
 826   return gdb_pymodule_addobject (gdb_module, "Membuf", (PyObject *)
 827                                  &membuf_object_type);
 828 }
 829
 830 static PyGetSetDef inferior_object_getset[] =
 831 {
 832   { "num", infpy_get_num, NULL, "ID of inferior, as assigned by GDB.", NULL },
 833   { "pid", infpy_get_pid, NULL, "PID of inferior, as assigned by the OS.",
 834     NULL },
 835   { "was_attached", infpy_get_was_attached, NULL,
 836     "True if the inferior was created using 'attach'.", NULL },
 837   { NULL }
 838 };
 839
 840 static PyMethodDef inferior_object_methods[] =
 841 {
 842   { "is_valid", infpy_is_valid, METH_NOARGS,
 843     "is_valid () -> Boolean.\n\
 844 Return true if this inferior is valid, false if not." },
 845   { "threads", infpy_threads, METH_NOARGS,
 846     "Return all the threads of this inferior." },
 847   { "read_memory", (PyCFunction) infpy_read_memory,
 848     METH_VARARGS | METH_KEYWORDS,
 849     "read_memory (address, length) -> buffer\n\
 850 Return a buffer object for reading from the inferior's memory." },
 851   { "write_memory", (PyCFunction) infpy_write_memory,
 852     METH_VARARGS | METH_KEYWORDS,
 853     "write_memory (address, buffer [, length])\n\
 854 Write the given buffer object to the inferior's memory." },
 855   { "search_memory", (PyCFunction) infpy_search_memory,
 856     METH_VARARGS | METH_KEYWORDS,
 857     "search_memory (address, length, pattern) -> long\n\
 858 Return a long with the address of a match, or None." },
 859   { NULL }
 860 };
 861
 862 PyTypeObject inferior_object_type =
 863 {
 864   PyVarObject_HEAD_INIT (NULL, 0)
 865   "gdb.Inferior",                 /* tp_name */
 866   sizeof (inferior_object),       /* tp_basicsize */
 867   0,                              /* tp_itemsize */
 868   infpy_dealloc,                  /* tp_dealloc */
 869   0,                              /* tp_print */
 870   0,                              /* tp_getattr */
 871   0,                              /* tp_setattr */
 872   0,                              /* tp_compare */
 873   0,                              /* tp_repr */
 874   0,                              /* tp_as_number */
 875   0,                              /* tp_as_sequence */
 876   0,                              /* tp_as_mapping */
 877   0,                              /* tp_hash  */
 878   0,                              /* tp_call */
 879   0,                              /* tp_str */
 880   0,                              /* tp_getattro */
 881   0,                              /* tp_setattro */
 882   0,                              /* tp_as_buffer */
 883   Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_ITER,  /* tp_flags */
 884   "GDB inferior object",          /* tp_doc */
 885   0,                              /* tp_traverse */
 886   0,                              /* tp_clear */
 887   0,                              /* tp_richcompare */
 888   0,                              /* tp_weaklistoffset */
 889   0,                              /* tp_iter */
 890   0,                              /* tp_iternext */
 891   inferior_object_methods,        /* tp_methods */
 892   0,                              /* tp_members */
 893   inferior_object_getset,         /* tp_getset */
 894   0,                              /* tp_base */
 895   0,                              /* tp_dict */
 896   0,                              /* tp_descr_get */
 897   0,                              /* tp_descr_set */
 898   0,                              /* tp_dictoffset */
 899   0,                              /* tp_init */
 900   0                               /* tp_alloc */
 901 };
 902
 903 #ifdef IS_PY3K
 904
 905 static PyBufferProcs buffer_procs =
 906 {
 907   get_buffer
 908 };
 909
 910 #else
 911
 912 /* Python doesn't provide a decent way to get compatibility here.  */
 913 #if HAVE_LIBPYTHON2_4
 914 #define CHARBUFFERPROC_NAME getcharbufferproc
 915 #else
 916 #define CHARBUFFERPROC_NAME charbufferproc
 917 #endif
 918
 919 static PyBufferProcs buffer_procs = {
 920   get_read_buffer,
 921   get_write_buffer,
 922   get_seg_count,
 923   /* The cast here works around a difference between Python 2.4 and
 924      Python 2.5.  */
 925   (CHARBUFFERPROC_NAME) get_char_buffer
 926 };
 927 #endif  /* IS_PY3K */
 928
 929 PyTypeObject membuf_object_type = {
 930   PyVarObject_HEAD_INIT (NULL, 0)
 931   "gdb.Membuf",                   /*tp_name*/
 932   sizeof (membuf_object),         /*tp_basicsize*/
 933   0,                              /*tp_itemsize*/
 934   mbpy_dealloc,                   /*tp_dealloc*/
 935   0,                              /*tp_print*/
 936   0,                              /*tp_getattr*/
 937   0,                              /*tp_setattr*/
 938   0,                              /*tp_compare*/
 939   0,                              /*tp_repr*/
 940   0,                              /*tp_as_number*/
 941   0,                              /*tp_as_sequence*/
 942   0,                              /*tp_as_mapping*/
 943   0,                              /*tp_hash */
 944   0,                              /*tp_call*/
 945   mbpy_str,                       /*tp_str*/
 946   0,                              /*tp_getattro*/
 947   0,                              /*tp_setattro*/
 948   &buffer_procs,                  /*tp_as_buffer*/
 949   Py_TPFLAGS_DEFAULT,             /*tp_flags*/
 950   "GDB memory buffer object",     /*tp_doc*/
 951   0,                              /* tp_traverse */
 952   0,                              /* tp_clear */
 953   0,                              /* tp_richcompare */
 954   0,                              /* tp_weaklistoffset */
 955   0,                              /* tp_iter */
 956   0,                              /* tp_iternext */
 957   0,                              /* tp_methods */
 958   0,                              /* tp_members */
 959   0,                              /* tp_getset */
 960   0,                              /* tp_base */
 961   0,                              /* tp_dict */
 962   0,                              /* tp_descr_get */
 963   0,                              /* tp_descr_set */
 964   0,                              /* tp_dictoffset */
 965   0,                              /* tp_init */
 966   0,                              /* tp_alloc */
 967 };