gdb/python/py-linetable.c

   1 /* Python interface to line tables.
   2
   3    Copyright (C) 2013-2017 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 "python-internal.h"
  22 #include "py-ref.h"
  23
  24 typedef struct {
  25   PyObject_HEAD
  26   /* The line table source line.  */
  27   int line;
  28   /* The pc associated with the source line.  */
  29   CORE_ADDR pc;
  30 } linetable_entry_object;
  31
  32 extern PyTypeObject linetable_entry_object_type
  33     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("linetable_entry_object");
  34
  35 typedef struct {
  36   PyObject_HEAD
  37   /* The symtab python object.  We store the Python object here as the
  38      underlying symtab can become invalid, and we have to run validity
  39      checks on it.  */
  40   PyObject *symtab;
  41 } linetable_object;
  42
  43 extern PyTypeObject linetable_object_type
  44     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("linetable_object");
  45
  46 typedef struct {
  47   PyObject_HEAD
  48   /* The current entry in the line table for the iterator  */
  49   int current_index;
  50   /* Pointer back to the original source line table object.  Needed to
  51      check if the line table is still valid, and has not been invalidated
  52      when an object file has been freed.  */
  53   PyObject *source;
  54 } ltpy_iterator_object;
  55
  56 extern PyTypeObject ltpy_iterator_object_type
  57     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("ltpy_iterator_object");
  58
  59 /* Internal helper function to extract gdb.Symtab from a gdb.LineTable
  60    object.  */
  61
  62 static PyObject *
  63 get_symtab (PyObject *linetable)
  64 {
  65   linetable_object *lt = (linetable_object *) linetable;
  66
  67   return lt->symtab;
  68 }
  69
  70 #define LTPY_REQUIRE_VALID(lt_obj, symtab)                              \
  71   do {                                                                  \
  72     symtab = symtab_object_to_symtab (get_symtab (lt_obj));             \
  73     if (symtab == NULL)                                                 \
  74       {                                                                 \
  75           PyErr_SetString (PyExc_RuntimeError,                          \
  76                            _("Symbol Table in line table is invalid."));\
  77           return NULL;                                                  \
  78         }                                                               \
  79   } while (0)
  80
  81
  82 /* Helper function to create a line table object that wraps a
  83    gdb.Symtab object.  */
  84
  85 PyObject *
  86 symtab_to_linetable_object (PyObject *symtab)
  87 {
  88   linetable_object *ltable;
  89
  90   ltable = PyObject_New (linetable_object, &linetable_object_type);
  91   if (ltable != NULL)
  92     {
  93       ltable->symtab = symtab;
  94       Py_INCREF (symtab);
  95     }
  96   return (PyObject *) ltable;
  97 }
  98
  99 /* Internal helper function to build a line table object from a line
 100    and an address.  */
 101
 102 static PyObject *
 103 build_linetable_entry (int line, CORE_ADDR address)
 104 {
 105   linetable_entry_object *obj;
 106
 107   obj = PyObject_New (linetable_entry_object,
 108                       &linetable_entry_object_type);
 109   if (obj != NULL)
 110     {
 111       obj->line = line;
 112       obj->pc = address;
 113     }
 114
 115   return (PyObject *) obj;
 116 }
 117
 118 /* Internal helper function to build a Python Tuple from a vector.
 119    A line table entry can have multiple PCs for a given source line.
 120    Construct a Tuple of all entries for the given source line, LINE
 121    from the line table PCS.  Construct one line table entry object per
 122    address.  */
 123
 124 static PyObject *
 125 build_line_table_tuple_from_pcs (int line, const std::vector<CORE_ADDR> &pcs)
 126 {
 127   int i;
 128
 129   if (pcs.size () < 1)
 130     Py_RETURN_NONE;
 131
 132   gdbpy_ref<> tuple (PyTuple_New (pcs.size ()));
 133
 134   if (tuple == NULL)
 135     return NULL;
 136
 137   for (i = 0; i < pcs.size (); ++i)
 138     {
 139       CORE_ADDR pc = pcs[i];
 140       gdbpy_ref<> obj (build_linetable_entry (line, pc));
 141
 142       if (obj == NULL)
 143         return NULL;
 144       else if (PyTuple_SetItem (tuple.get (), i, obj.release ()) != 0)
 145         return NULL;
 146     }
 147
 148   return tuple.release ();
 149 }
 150
 151 /* Implementation of gdb.LineTable.line (self) -> Tuple.  Returns a
 152    tuple of LineTableEntry objects associated with this line from the
 153    in the line table.  */
 154
 155 static PyObject *
 156 ltpy_get_pcs_for_line (PyObject *self, PyObject *args)
 157 {
 158   struct symtab *symtab;
 159   gdb_py_longest py_line;
 160   struct linetable_entry *best_entry = NULL;
 161   std::vector<CORE_ADDR> pcs;
 162
 163   LTPY_REQUIRE_VALID (self, symtab);
 164
 165   if (! PyArg_ParseTuple (args, GDB_PY_LL_ARG, &py_line))
 166     return NULL;
 167
 168   TRY
 169     {
 170       pcs = find_pcs_for_symtab_line (symtab, py_line, &best_entry);
 171     }
 172   CATCH (except, RETURN_MASK_ALL)
 173     {
 174       GDB_PY_HANDLE_EXCEPTION (except);
 175     }
 176   END_CATCH
 177
 178   return build_line_table_tuple_from_pcs (py_line, pcs);
 179 }
 180
 181 /* Implementation of gdb.LineTable.has_line (self, line) -> Boolean.
 182    Returns a Python Boolean indicating whether a source line has any
 183    line table entries corresponding to it.  */
 184
 185 static PyObject *
 186 ltpy_has_line (PyObject *self, PyObject *args)
 187 {
 188   struct symtab *symtab;
 189   gdb_py_longest py_line;
 190   int index;
 191
 192   LTPY_REQUIRE_VALID (self, symtab);
 193
 194   if (! PyArg_ParseTuple (args, GDB_PY_LL_ARG, &py_line))
 195     return NULL;
 196
 197   if (SYMTAB_LINETABLE (symtab) == NULL)
 198     {
 199       PyErr_SetString (PyExc_RuntimeError,
 200                        _("Linetable information not found in symbol table"));
 201       return NULL;
 202     }
 203
 204   for (index = 0; index < SYMTAB_LINETABLE (symtab)->nitems; index++)
 205     {
 206       struct linetable_entry *item = &(SYMTAB_LINETABLE (symtab)->item[index]);
 207       if (item->line == py_line)
 208           Py_RETURN_TRUE;
 209     }
 210
 211   Py_RETURN_FALSE;
 212 }
 213
 214 /* Implementation of gdb.LineTable.source_lines (self) -> List.
 215    Returns a Python List that contains source line entries in the
 216    line table.  This function will just return the source lines
 217    without corresponding addresses.  */
 218
 219 static PyObject *
 220 ltpy_get_all_source_lines (PyObject *self, PyObject *args)
 221 {
 222   struct symtab *symtab;
 223   Py_ssize_t index;
 224   struct linetable_entry *item;
 225
 226   LTPY_REQUIRE_VALID (self, symtab);
 227
 228   if (SYMTAB_LINETABLE (symtab) == NULL)
 229     {
 230       PyErr_SetString (PyExc_RuntimeError,
 231                        _("Linetable information not found in symbol table"));
 232       return NULL;
 233     }
 234
 235   gdbpy_ref<> source_dict (PyDict_New ());
 236   if (source_dict == NULL)
 237     return NULL;
 238
 239   for (index = 0; index < SYMTAB_LINETABLE (symtab)->nitems; index++)
 240     {
 241       item = &(SYMTAB_LINETABLE (symtab)->item[index]);
 242
 243       /* 0 is used to signify end of line table information.  Do not
 244          include in the source set. */
 245       if (item->line > 0)
 246         {
 247           gdbpy_ref<> line (gdb_py_object_from_longest (item->line));
 248
 249           if (line == NULL)
 250             return NULL;
 251
 252           if (PyDict_SetItem (source_dict.get (), line.get (), Py_None) == -1)
 253             return NULL;
 254         }
 255     }
 256
 257   return PyDict_Keys (source_dict.get ());
 258 }
 259
 260 /* Implementation of gdb.LineTable.is_valid (self) -> Boolean.
 261    Returns True if this line table object still exists in GDB.  */
 262
 263 static PyObject *
 264 ltpy_is_valid (PyObject *self, PyObject *args)
 265 {
 266   struct symtab *symtab = NULL;
 267
 268   symtab = symtab_object_to_symtab (get_symtab (self));
 269
 270   if (symtab == NULL)
 271     Py_RETURN_FALSE;
 272
 273   Py_RETURN_TRUE;
 274 }
 275
 276 /* Deconstructor for the line table object.  Decrement the reference
 277    to the symbol table object before calling the default free.  */
 278
 279 static void
 280 ltpy_dealloc (PyObject *self)
 281 {
 282   linetable_object *obj = (linetable_object *) self;
 283
 284   Py_DECREF (obj->symtab);
 285   Py_TYPE (self)->tp_free (self);
 286 }
 287
 288 /* Initialize LineTable, LineTableEntry and LineTableIterator
 289    objects.  */
 290
 291 int
 292 gdbpy_initialize_linetable (void)
 293 {
 294   if (PyType_Ready (&linetable_object_type) < 0)
 295     return -1;
 296   if (PyType_Ready (&linetable_entry_object_type) < 0)
 297     return -1;
 298   if (PyType_Ready (&ltpy_iterator_object_type) < 0)
 299     return -1;
 300
 301   Py_INCREF (&linetable_object_type);
 302   Py_INCREF (&linetable_entry_object_type);
 303   Py_INCREF (&ltpy_iterator_object_type);
 304
 305   if (gdb_pymodule_addobject (gdb_module, "LineTable",
 306                               (PyObject *) &linetable_object_type) < 0)
 307     return -1;
 308
 309   if (gdb_pymodule_addobject (gdb_module, "LineTableEntry",
 310                               (PyObject *) &linetable_entry_object_type) < 0)
 311     return -1;
 312
 313   if (gdb_pymodule_addobject (gdb_module, "LineTableIterator",
 314                               (PyObject *) &ltpy_iterator_object_type) < 0)
 315     return -1;
 316
 317   return 0;
 318 }
 319
 320 /* LineTable entry object get functions.  */
 321
 322 /* Implementation of gdb.LineTableEntry.line (self) -> Long.  Returns
 323    a long integer associated with the line table entry.  */
 324
 325 static PyObject *
 326 ltpy_entry_get_line (PyObject *self, void *closure)
 327 {
 328   linetable_entry_object *obj = (linetable_entry_object *) self;
 329
 330   return gdb_py_object_from_longest (obj->line);
 331 }
 332
 333 /* Implementation of gdb.LineTableEntry.pc (self) -> Long.  Returns a
 334    a long integer associated with the PC of the line table entry.  */
 335
 336 static PyObject *
 337 ltpy_entry_get_pc (PyObject *self, void *closure)
 338 {
 339   linetable_entry_object *obj = (linetable_entry_object *) self;
 340
 341   return  gdb_py_object_from_longest (obj->pc);
 342 }
 343
 344 /* LineTable iterator functions.  */
 345
 346 /* Return a new line table iterator.  */
 347
 348 static PyObject *
 349 ltpy_iter (PyObject *self)
 350 {
 351   ltpy_iterator_object *ltpy_iter_obj;
 352   struct symtab *symtab = NULL;
 353
 354   LTPY_REQUIRE_VALID (self, symtab);
 355
 356   ltpy_iter_obj = PyObject_New (ltpy_iterator_object,
 357                                 &ltpy_iterator_object_type);
 358   if (ltpy_iter_obj == NULL)
 359     return NULL;
 360
 361   ltpy_iter_obj->current_index = 0;
 362   ltpy_iter_obj->source = self;
 363
 364   Py_INCREF (self);
 365   return (PyObject *) ltpy_iter_obj;
 366 }
 367
 368 static void
 369 ltpy_iterator_dealloc (PyObject *obj)
 370 {
 371   ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) obj;
 372
 373   Py_DECREF (iter_obj->source);
 374 }
 375
 376 /* Return a reference to the line table iterator.  */
 377
 378 static PyObject *
 379 ltpy_iterator (PyObject *self)
 380 {
 381   ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) self;
 382   struct symtab *symtab;
 383
 384   LTPY_REQUIRE_VALID (iter_obj->source, symtab);
 385
 386   Py_INCREF (self);
 387   return self;
 388 }
 389
 390 /* Return the next line table entry in the iteration through the line
 391    table data structure.  */
 392
 393 static PyObject *
 394 ltpy_iternext (PyObject *self)
 395 {
 396   ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) self;
 397   struct symtab *symtab;
 398   PyObject *obj;
 399   struct linetable_entry *item;
 400
 401   LTPY_REQUIRE_VALID (iter_obj->source, symtab);
 402
 403   if (iter_obj->current_index >= SYMTAB_LINETABLE (symtab)->nitems)
 404     {
 405       PyErr_SetNone (PyExc_StopIteration);
 406       return NULL;
 407     }
 408
 409   item = &(SYMTAB_LINETABLE (symtab)->item[iter_obj->current_index]);
 410
 411   /* Skip over internal entries such as 0.  0 signifies the end of
 412      line table data and is not useful to the API user.  */
 413   while (item->line < 1)
 414     {
 415       iter_obj->current_index++;
 416
 417       /* Exit if the internal value is the last item in the line table.  */
 418       if (iter_obj->current_index >= SYMTAB_LINETABLE (symtab)->nitems)
 419         {
 420           PyErr_SetNone (PyExc_StopIteration);
 421           return NULL;
 422         }
 423       item = &(SYMTAB_LINETABLE (symtab)->item[iter_obj->current_index]);
 424     }
 425
 426   obj = build_linetable_entry (item->line, item->pc);
 427   iter_obj->current_index++;
 428
 429   return obj;
 430 }
 431
 432 /* Implementation of gdb.LineTableIterator.is_valid (self) -> Boolean.
 433    Returns True if this line table iterator object still exists in
 434    GDB.  */
 435
 436 static PyObject *
 437 ltpy_iter_is_valid (PyObject *self, PyObject *args)
 438 {
 439   struct symtab *symtab = NULL;
 440   ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) self;
 441
 442   symtab = symtab_object_to_symtab (get_symtab (iter_obj->source));
 443
 444   if (symtab == NULL)
 445     Py_RETURN_FALSE;
 446
 447   Py_RETURN_TRUE;
 448 }
 449
 450 \f
 451
 452 static PyMethodDef linetable_object_methods[] = {
 453   { "line", ltpy_get_pcs_for_line, METH_VARARGS,
 454     "line (lineno) -> Tuple\n\
 455 Return executable locations for a given source line." },
 456   { "has_line", ltpy_has_line, METH_VARARGS,
 457     "has_line (lineno) -> Boolean\n\
 458 Return TRUE if this line has executable information, FALSE if not." },
 459   { "source_lines", ltpy_get_all_source_lines, METH_NOARGS,
 460     "source_lines () -> List\n\
 461 Return a list of all executable source lines." },
 462   { "is_valid", ltpy_is_valid, METH_NOARGS,
 463     "is_valid () -> Boolean.\n\
 464 Return True if this LineTable is valid, False if not." },
 465   {NULL}  /* Sentinel */
 466 };
 467
 468 PyTypeObject linetable_object_type = {
 469   PyVarObject_HEAD_INIT (NULL, 0)
 470   "gdb.LineTable",                /*tp_name*/
 471   sizeof (linetable_object),      /*tp_basicsize*/
 472   0,                              /*tp_itemsize*/
 473   ltpy_dealloc,                   /*tp_dealloc*/
 474   0,                              /*tp_print*/
 475   0,                              /*tp_getattr*/
 476   0,                              /*tp_setattr*/
 477   0,                              /*tp_compare*/
 478   0,                              /*tp_repr*/
 479   0,                              /*tp_as_number*/
 480   0,                              /*tp_as_sequence*/
 481   0,                              /*tp_as_mapping*/
 482   0,                              /*tp_hash */
 483   0,                              /*tp_call*/
 484   0,                              /*tp_str*/
 485   0,                              /*tp_getattro*/
 486   0,                              /*tp_setattro*/
 487   0,                              /*tp_as_buffer*/
 488   Py_TPFLAGS_DEFAULT,             /*tp_flags*/
 489   "GDB line table object",        /* tp_doc */
 490   0,                              /* tp_traverse */
 491   0,                              /* tp_clear */
 492   0,                              /* tp_richcompare */
 493   0,                              /* tp_weaklistoffset */
 494   ltpy_iter,                      /* tp_iter */
 495   0,                              /* tp_iternext */
 496   linetable_object_methods,       /* tp_methods */
 497   0,                              /* tp_members */
 498   0,                              /* tp_getset */
 499   0,                              /* tp_base */
 500   0,                              /* tp_dict */
 501   0,                              /* tp_descr_get */
 502   0,                              /* tp_descr_set */
 503   0,                              /* tp_dictoffset */
 504   0,                              /* tp_init */
 505   0,                              /* tp_alloc */
 506 };
 507
 508 static PyMethodDef ltpy_iterator_methods[] = {
 509   { "is_valid", ltpy_iter_is_valid, METH_NOARGS,
 510     "is_valid () -> Boolean.\n\
 511 Return True if this LineTable iterator is valid, False if not." },
 512   {NULL}  /* Sentinel */
 513 };
 514
 515 PyTypeObject ltpy_iterator_object_type = {
 516   PyVarObject_HEAD_INIT (NULL, 0)
 517   "gdb.LineTableIterator",                /*tp_name*/
 518   sizeof (ltpy_iterator_object),  /*tp_basicsize*/
 519   0,                              /*tp_itemsize*/
 520   ltpy_iterator_dealloc,          /*tp_dealloc*/
 521   0,                              /*tp_print*/
 522   0,                              /*tp_getattr*/
 523   0,                              /*tp_setattr*/
 524   0,                              /*tp_compare*/
 525   0,                              /*tp_repr*/
 526   0,                              /*tp_as_number*/
 527   0,                              /*tp_as_sequence*/
 528   0,                              /*tp_as_mapping*/
 529   0,                              /*tp_hash */
 530   0,                              /*tp_call*/
 531   0,                              /*tp_str*/
 532   0,                              /*tp_getattro*/
 533   0,                              /*tp_setattro*/
 534   0,                              /*tp_as_buffer*/
 535   Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_ITER,  /*tp_flags*/
 536   "GDB line table iterator object",           /*tp_doc */
 537   0,                              /*tp_traverse */
 538   0,                              /*tp_clear */
 539   0,                              /*tp_richcompare */
 540   0,                              /*tp_weaklistoffset */
 541   ltpy_iterator,                  /*tp_iter */
 542   ltpy_iternext,                  /*tp_iternext */
 543   ltpy_iterator_methods           /*tp_methods */
 544 };
 545
 546
 547 static gdb_PyGetSetDef linetable_entry_object_getset[] = {
 548   { "line", ltpy_entry_get_line, NULL,
 549     "The line number in the source file.", NULL },
 550   { "pc", ltpy_entry_get_pc, NULL,
 551     "The memory address for this line number.", NULL },
 552   { NULL }  /* Sentinel */
 553 };
 554
 555 PyTypeObject linetable_entry_object_type = {
 556   PyVarObject_HEAD_INIT (NULL, 0)
 557   "gdb.LineTableEntry",           /*tp_name*/
 558   sizeof (linetable_entry_object), /*tp_basicsize*/
 559   0,                              /*tp_itemsize*/
 560   0,                              /*tp_dealloc*/
 561   0,                              /*tp_print*/
 562   0,                              /*tp_getattr*/
 563   0,                              /*tp_setattr*/
 564   0,                              /*tp_compare*/
 565   0,                              /*tp_repr*/
 566   0,                              /*tp_as_number*/
 567   0,                              /*tp_as_sequence*/
 568   0,                              /*tp_as_mapping*/
 569   0,                              /*tp_hash */
 570   0,                              /*tp_call*/
 571   0,                              /*tp_str*/
 572   0,                              /*tp_getattro*/
 573   0,                              /*tp_setattro*/
 574   0,                              /*tp_as_buffer*/
 575   Py_TPFLAGS_DEFAULT,             /*tp_flags*/
 576   "GDB line table entry object",  /* tp_doc */
 577   0,                              /* tp_traverse */
 578   0,                              /* tp_clear */
 579   0,                              /* tp_richcompare */
 580   0,                              /* tp_weaklistoffset */
 581   0,                              /* tp_iter */
 582   0,                              /* tp_iternext */
 583   0,                              /* tp_methods */
 584   0,                              /* tp_members */
 585   linetable_entry_object_getset,  /* tp_getset */
 586   0,                              /* tp_base */
 587   0,                              /* tp_dict */
 588   0,                              /* tp_descr_get */
 589   0,                              /* tp_descr_set */
 590   0,                              /* tp_dictoffset */
 591   0,                              /* tp_init */
 592   0,                              /* tp_alloc */
 593 };