gdb/python/py-linetable.c

   1 /* Python interface to line tables.
   2
   3    Copyright (C) 2013-2020 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
  23 typedef struct {
  24   PyObject_HEAD
  25   /* The line table source line.  */
  26   int line;
  27   /* The pc associated with the source line.  */
  28   CORE_ADDR pc;
  29 } linetable_entry_object;
  30
  31 extern PyTypeObject linetable_entry_object_type
  32     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("linetable_entry_object");
  33
  34 typedef struct {
  35   PyObject_HEAD
  36   /* The symtab python object.  We store the Python object here as the
  37      underlying symtab can become invalid, and we have to run validity
  38      checks on it.  */
  39   PyObject *symtab;
  40 } linetable_object;
  41
  42 extern PyTypeObject linetable_object_type
  43     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("linetable_object");
  44
  45 typedef struct {
  46   PyObject_HEAD
  47   /* The current entry in the line table for the iterator  */
  48   int current_index;
  49   /* Pointer back to the original source line table object.  Needed to
  50      check if the line table is still valid, and has not been invalidated
  51      when an object file has been freed.  */
  52   PyObject *source;
  53 } ltpy_iterator_object;
  54
  55 extern PyTypeObject ltpy_iterator_object_type
  56     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("ltpy_iterator_object");
  57
  58 /* Internal helper function to extract gdb.Symtab from a gdb.LineTable
  59    object.  */
  60
  61 static PyObject *
  62 get_symtab (PyObject *linetable)
  63 {
  64   linetable_object *lt = (linetable_object *) linetable;
  65
  66   return lt->symtab;
  67 }
  68
  69 #define LTPY_REQUIRE_VALID(lt_obj, symtab)                              \
  70   do {                                                                  \
  71     symtab = symtab_object_to_symtab (get_symtab (lt_obj));             \
  72     if (symtab == NULL)                                                 \
  73       {                                                                 \
  74           PyErr_SetString (PyExc_RuntimeError,                          \
  75                            _("Symbol Table in line table is invalid."));\
  76           return NULL;                                                  \
  77         }                                                               \
  78   } while (0)
  79
  80
  81 /* Helper function to create a line table object that wraps a
  82    gdb.Symtab object.  */
  83
  84 PyObject *
  85 symtab_to_linetable_object (PyObject *symtab)
  86 {
  87   linetable_object *ltable;
  88
  89   ltable = PyObject_New (linetable_object, &linetable_object_type);
  90   if (ltable != NULL)
  91     {
  92       ltable->symtab = symtab;
  93       Py_INCREF (symtab);
  94     }
  95   return (PyObject *) ltable;
  96 }
  97
  98 /* Internal helper function to build a line table object from a line
  99    and an address.  */
 100
 101 static PyObject *
 102 build_linetable_entry (int line, CORE_ADDR address)
 103 {
 104   linetable_entry_object *obj;
 105
 106   obj = PyObject_New (linetable_entry_object,
 107                       &linetable_entry_object_type);
 108   if (obj != NULL)
 109     {
 110       obj->line = line;
 111       obj->pc = address;
 112     }
 113
 114   return (PyObject *) obj;
 115 }
 116
 117 /* Internal helper function to build a Python Tuple from a vector.
 118    A line table entry can have multiple PCs for a given source line.
 119    Construct a Tuple of all entries for the given source line, LINE
 120    from the line table PCS.  Construct one line table entry object per
 121    address.  */
 122
 123 static PyObject *
 124 build_line_table_tuple_from_pcs (int line, const std::vector<CORE_ADDR> &pcs)
 125 {
 126   int i;
 127
 128   if (pcs.size () < 1)
 129     Py_RETURN_NONE;
 130
 131   gdbpy_ref<> tuple (PyTuple_New (pcs.size ()));
 132
 133   if (tuple == NULL)
 134     return NULL;
 135
 136   for (i = 0; i < pcs.size (); ++i)
 137     {
 138       CORE_ADDR pc = pcs[i];
 139       gdbpy_ref<> obj (build_linetable_entry (line, pc));
 140
 141       if (obj == NULL)
 142         return NULL;
 143       else if (PyTuple_SetItem (tuple.get (), i, obj.release ()) != 0)
 144         return NULL;
 145     }
 146
 147   return tuple.release ();
 148 }
 149
 150 /* Implementation of gdb.LineTable.line (self) -> Tuple.  Returns a
 151    tuple of LineTableEntry objects associated with this line from the
 152    in the line table.  */
 153
 154 static PyObject *
 155 ltpy_get_pcs_for_line (PyObject *self, PyObject *args)
 156 {
 157   struct symtab *symtab;
 158   gdb_py_longest py_line;
 159   struct linetable_entry *best_entry = NULL;
 160   std::vector<CORE_ADDR> pcs;
 161
 162   LTPY_REQUIRE_VALID (self, symtab);
 163
 164   if (! PyArg_ParseTuple (args, GDB_PY_LL_ARG, &py_line))
 165     return NULL;
 166
 167   try
 168     {
 169       pcs = find_pcs_for_symtab_line (symtab, py_line, &best_entry);
 170     }
 171   catch (const gdb_exception &except)
 172     {
 173       GDB_PY_HANDLE_EXCEPTION (except);
 174     }
 175
 176   return build_line_table_tuple_from_pcs (py_line, pcs);
 177 }
 178
 179 /* Implementation of gdb.LineTable.has_line (self, line) -> Boolean.
 180    Returns a Python Boolean indicating whether a source line has any
 181    line table entries corresponding to it.  */
 182
 183 static PyObject *
 184 ltpy_has_line (PyObject *self, PyObject *args)
 185 {
 186   struct symtab *symtab;
 187   gdb_py_longest py_line;
 188   int index;
 189
 190   LTPY_REQUIRE_VALID (self, symtab);
 191
 192   if (! PyArg_ParseTuple (args, GDB_PY_LL_ARG, &py_line))
 193     return NULL;
 194
 195   if (SYMTAB_LINETABLE (symtab) == NULL)
 196     {
 197       PyErr_SetString (PyExc_RuntimeError,
 198                        _("Linetable information not found in symbol table"));
 199       return NULL;
 200     }
 201
 202   for (index = 0; index < SYMTAB_LINETABLE (symtab)->nitems; index++)
 203     {
 204       struct linetable_entry *item = &(SYMTAB_LINETABLE (symtab)->item[index]);
 205       if (item->line == py_line)
 206           Py_RETURN_TRUE;
 207     }
 208
 209   Py_RETURN_FALSE;
 210 }
 211
 212 /* Implementation of gdb.LineTable.source_lines (self) -> List.
 213    Returns a Python List that contains source line entries in the
 214    line table.  This function will just return the source lines
 215    without corresponding addresses.  */
 216
 217 static PyObject *
 218 ltpy_get_all_source_lines (PyObject *self, PyObject *args)
 219 {
 220   struct symtab *symtab;
 221   Py_ssize_t index;
 222   struct linetable_entry *item;
 223
 224   LTPY_REQUIRE_VALID (self, symtab);
 225
 226   if (SYMTAB_LINETABLE (symtab) == NULL)
 227     {
 228       PyErr_SetString (PyExc_RuntimeError,
 229                        _("Linetable information not found in symbol table"));
 230       return NULL;
 231     }
 232
 233   gdbpy_ref<> source_dict (PyDict_New ());
 234   if (source_dict == NULL)
 235     return NULL;
 236
 237   for (index = 0; index < SYMTAB_LINETABLE (symtab)->nitems; index++)
 238     {
 239       item = &(SYMTAB_LINETABLE (symtab)->item[index]);
 240
 241       /* 0 is used to signify end of line table information.  Do not
 242          include in the source set. */
 243       if (item->line > 0)
 244         {
 245           gdbpy_ref<> line = gdb_py_object_from_longest (item->line);
 246
 247           if (line == NULL)
 248             return NULL;
 249
 250           if (PyDict_SetItem (source_dict.get (), line.get (), Py_None) == -1)
 251             return NULL;
 252         }
 253     }
 254
 255   return PyDict_Keys (source_dict.get ());
 256 }
 257
 258 /* Implementation of gdb.LineTable.is_valid (self) -> Boolean.
 259    Returns True if this line table object still exists in GDB.  */
 260
 261 static PyObject *
 262 ltpy_is_valid (PyObject *self, PyObject *args)
 263 {
 264   struct symtab *symtab = NULL;
 265
 266   symtab = symtab_object_to_symtab (get_symtab (self));
 267
 268   if (symtab == NULL)
 269     Py_RETURN_FALSE;
 270
 271   Py_RETURN_TRUE;
 272 }
 273
 274 /* Deconstructor for the line table object.  Decrement the reference
 275    to the symbol table object before calling the default free.  */
 276
 277 static void
 278 ltpy_dealloc (PyObject *self)
 279 {
 280   linetable_object *obj = (linetable_object *) self;
 281
 282   Py_DECREF (obj->symtab);
 283   Py_TYPE (self)->tp_free (self);
 284 }
 285
 286 /* Initialize LineTable, LineTableEntry and LineTableIterator
 287    objects.  */
 288
 289 int
 290 gdbpy_initialize_linetable (void)
 291 {
 292   if (PyType_Ready (&linetable_object_type) < 0)
 293     return -1;
 294   if (PyType_Ready (&linetable_entry_object_type) < 0)
 295     return -1;
 296   if (PyType_Ready (&ltpy_iterator_object_type) < 0)
 297     return -1;
 298
 299   Py_INCREF (&linetable_object_type);
 300   Py_INCREF (&linetable_entry_object_type);
 301   Py_INCREF (&ltpy_iterator_object_type);
 302
 303   if (gdb_pymodule_addobject (gdb_module, "LineTable",
 304                               (PyObject *) &linetable_object_type) < 0)
 305     return -1;
 306
 307   if (gdb_pymodule_addobject (gdb_module, "LineTableEntry",
 308                               (PyObject *) &linetable_entry_object_type) < 0)
 309     return -1;
 310
 311   if (gdb_pymodule_addobject (gdb_module, "LineTableIterator",
 312                               (PyObject *) &ltpy_iterator_object_type) < 0)
 313     return -1;
 314
 315   return 0;
 316 }
 317
 318 /* LineTable entry object get functions.  */
 319
 320 /* Implementation of gdb.LineTableEntry.line (self) -> Long.  Returns
 321    a long integer associated with the line table entry.  */
 322
 323 static PyObject *
 324 ltpy_entry_get_line (PyObject *self, void *closure)
 325 {
 326   linetable_entry_object *obj = (linetable_entry_object *) self;
 327
 328   return gdb_py_object_from_longest (obj->line).release ();
 329 }
 330
 331 /* Implementation of gdb.LineTableEntry.pc (self) -> Long.  Returns a
 332    a long integer associated with the PC of the line table entry.  */
 333
 334 static PyObject *
 335 ltpy_entry_get_pc (PyObject *self, void *closure)
 336 {
 337   linetable_entry_object *obj = (linetable_entry_object *) self;
 338
 339   return gdb_py_object_from_ulongest (obj->pc).release ();
 340 }
 341
 342 /* LineTable iterator functions.  */
 343
 344 /* Return a new line table iterator.  */
 345
 346 static PyObject *
 347 ltpy_iter (PyObject *self)
 348 {
 349   ltpy_iterator_object *ltpy_iter_obj;
 350   struct symtab *symtab = NULL;
 351
 352   LTPY_REQUIRE_VALID (self, symtab);
 353
 354   ltpy_iter_obj = PyObject_New (ltpy_iterator_object,
 355                                 &ltpy_iterator_object_type);
 356   if (ltpy_iter_obj == NULL)
 357     return NULL;
 358
 359   ltpy_iter_obj->current_index = 0;
 360   ltpy_iter_obj->source = self;
 361
 362   Py_INCREF (self);
 363   return (PyObject *) ltpy_iter_obj;
 364 }
 365
 366 static void
 367 ltpy_iterator_dealloc (PyObject *obj)
 368 {
 369   ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) obj;
 370
 371   Py_DECREF (iter_obj->source);
 372   Py_TYPE (obj)->tp_free (obj);
 373 }
 374
 375 /* Return a reference to the line table iterator.  */
 376
 377 static PyObject *
 378 ltpy_iterator (PyObject *self)
 379 {
 380   ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) self;
 381   struct symtab *symtab;
 382
 383   LTPY_REQUIRE_VALID (iter_obj->source, symtab);
 384
 385   Py_INCREF (self);
 386   return self;
 387 }
 388
 389 /* Return the next line table entry in the iteration through the line
 390    table data structure.  */
 391
 392 static PyObject *
 393 ltpy_iternext (PyObject *self)
 394 {
 395   ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) self;
 396   struct symtab *symtab;
 397   PyObject *obj;
 398   struct linetable_entry *item;
 399
 400   LTPY_REQUIRE_VALID (iter_obj->source, symtab);
 401
 402   if (iter_obj->current_index >= SYMTAB_LINETABLE (symtab)->nitems)
 403     {
 404       PyErr_SetNone (PyExc_StopIteration);
 405       return NULL;
 406     }
 407
 408   item = &(SYMTAB_LINETABLE (symtab)->item[iter_obj->current_index]);
 409
 410   /* Skip over internal entries such as 0.  0 signifies the end of
 411      line table data and is not useful to the API user.  */
 412   while (item->line < 1)
 413     {
 414       iter_obj->current_index++;
 415
 416       /* Exit if the internal value is the last item in the line table.  */
 417       if (iter_obj->current_index >= SYMTAB_LINETABLE (symtab)->nitems)
 418         {
 419           PyErr_SetNone (PyExc_StopIteration);
 420           return NULL;
 421         }
 422       item = &(SYMTAB_LINETABLE (symtab)->item[iter_obj->current_index]);
 423     }
 424
 425   obj = build_linetable_entry (item->line, item->pc);
 426   iter_obj->current_index++;
 427
 428   return obj;
 429 }
 430
 431 /* Implementation of gdb.LineTableIterator.is_valid (self) -> Boolean.
 432    Returns True if this line table iterator object still exists in
 433    GDB.  */
 434
 435 static PyObject *
 436 ltpy_iter_is_valid (PyObject *self, PyObject *args)
 437 {
 438   struct symtab *symtab = NULL;
 439   ltpy_iterator_object *iter_obj = (ltpy_iterator_object *) self;
 440
 441   symtab = symtab_object_to_symtab (get_symtab (iter_obj->source));
 442
 443   if (symtab == NULL)
 444     Py_RETURN_FALSE;
 445
 446   Py_RETURN_TRUE;
 447 }
 448
 449 \f
 450
 451 static PyMethodDef linetable_object_methods[] = {
 452   { "line", ltpy_get_pcs_for_line, METH_VARARGS,
 453     "line (lineno) -> Tuple\n\
 454 Return executable locations for a given source line." },
 455   { "has_line", ltpy_has_line, METH_VARARGS,
 456     "has_line (lineno) -> Boolean\n\
 457 Return TRUE if this line has executable information, FALSE if not." },
 458   { "source_lines", ltpy_get_all_source_lines, METH_NOARGS,
 459     "source_lines () -> List\n\
 460 Return a list of all executable source lines." },
 461   { "is_valid", ltpy_is_valid, METH_NOARGS,
 462     "is_valid () -> Boolean.\n\
 463 Return True if this LineTable is valid, False if not." },
 464   {NULL}  /* Sentinel */
 465 };
 466
 467 PyTypeObject linetable_object_type = {
 468   PyVarObject_HEAD_INIT (NULL, 0)
 469   "gdb.LineTable",                /*tp_name*/
 470   sizeof (linetable_object),      /*tp_basicsize*/
 471   0,                              /*tp_itemsize*/
 472   ltpy_dealloc,                   /*tp_dealloc*/
 473   0,                              /*tp_print*/
 474   0,                              /*tp_getattr*/
 475   0,                              /*tp_setattr*/
 476   0,                              /*tp_compare*/
 477   0,                              /*tp_repr*/
 478   0,                              /*tp_as_number*/
 479   0,                              /*tp_as_sequence*/
 480   0,                              /*tp_as_mapping*/
 481   0,                              /*tp_hash */
 482   0,                              /*tp_call*/
 483   0,                              /*tp_str*/
 484   0,                              /*tp_getattro*/
 485   0,                              /*tp_setattro*/
 486   0,                              /*tp_as_buffer*/
 487   Py_TPFLAGS_DEFAULT,             /*tp_flags*/
 488   "GDB line table object",        /* tp_doc */
 489   0,                              /* tp_traverse */
 490   0,                              /* tp_clear */
 491   0,                              /* tp_richcompare */
 492   0,                              /* tp_weaklistoffset */
 493   ltpy_iter,                      /* tp_iter */
 494   0,                              /* tp_iternext */
 495   linetable_object_methods,       /* tp_methods */
 496   0,                              /* tp_members */
 497   0,                              /* tp_getset */
 498   0,                              /* tp_base */
 499   0,                              /* tp_dict */
 500   0,                              /* tp_descr_get */
 501   0,                              /* tp_descr_set */
 502   0,                              /* tp_dictoffset */
 503   0,                              /* tp_init */
 504   0,                              /* tp_alloc */
 505 };
 506
 507 static PyMethodDef ltpy_iterator_methods[] = {
 508   { "is_valid", ltpy_iter_is_valid, METH_NOARGS,
 509     "is_valid () -> Boolean.\n\
 510 Return True if this LineTable iterator is valid, False if not." },
 511   {NULL}  /* Sentinel */
 512 };
 513
 514 PyTypeObject ltpy_iterator_object_type = {
 515   PyVarObject_HEAD_INIT (NULL, 0)
 516   "gdb.LineTableIterator",                /*tp_name*/
 517   sizeof (ltpy_iterator_object),  /*tp_basicsize*/
 518   0,                              /*tp_itemsize*/
 519   ltpy_iterator_dealloc,          /*tp_dealloc*/
 520   0,                              /*tp_print*/
 521   0,                              /*tp_getattr*/
 522   0,                              /*tp_setattr*/
 523   0,                              /*tp_compare*/
 524   0,                              /*tp_repr*/
 525   0,                              /*tp_as_number*/
 526   0,                              /*tp_as_sequence*/
 527   0,                              /*tp_as_mapping*/
 528   0,                              /*tp_hash */
 529   0,                              /*tp_call*/
 530   0,                              /*tp_str*/
 531   0,                              /*tp_getattro*/
 532   0,                              /*tp_setattro*/
 533   0,                              /*tp_as_buffer*/
 534   Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_ITER,  /*tp_flags*/
 535   "GDB line table iterator object",           /*tp_doc */
 536   0,                              /*tp_traverse */
 537   0,                              /*tp_clear */
 538   0,                              /*tp_richcompare */
 539   0,                              /*tp_weaklistoffset */
 540   ltpy_iterator,                  /*tp_iter */
 541   ltpy_iternext,                  /*tp_iternext */
 542   ltpy_iterator_methods           /*tp_methods */
 543 };
 544
 545
 546 static gdb_PyGetSetDef linetable_entry_object_getset[] = {
 547   { "line", ltpy_entry_get_line, NULL,
 548     "The line number in the source file.", NULL },
 549   { "pc", ltpy_entry_get_pc, NULL,
 550     "The memory address for this line number.", NULL },
 551   { NULL }  /* Sentinel */
 552 };
 553
 554 PyTypeObject linetable_entry_object_type = {
 555   PyVarObject_HEAD_INIT (NULL, 0)
 556   "gdb.LineTableEntry",           /*tp_name*/
 557   sizeof (linetable_entry_object), /*tp_basicsize*/
 558   0,                              /*tp_itemsize*/
 559   0,                              /*tp_dealloc*/
 560   0,                              /*tp_print*/
 561   0,                              /*tp_getattr*/
 562   0,                              /*tp_setattr*/
 563   0,                              /*tp_compare*/
 564   0,                              /*tp_repr*/
 565   0,                              /*tp_as_number*/
 566   0,                              /*tp_as_sequence*/
 567   0,                              /*tp_as_mapping*/
 568   0,                              /*tp_hash */
 569   0,                              /*tp_call*/
 570   0,                              /*tp_str*/
 571   0,                              /*tp_getattro*/
 572   0,                              /*tp_setattro*/
 573   0,                              /*tp_as_buffer*/
 574   Py_TPFLAGS_DEFAULT,             /*tp_flags*/
 575   "GDB line table entry object",  /* tp_doc */
 576   0,                              /* tp_traverse */
 577   0,                              /* tp_clear */
 578   0,                              /* tp_richcompare */
 579   0,                              /* tp_weaklistoffset */
 580   0,                              /* tp_iter */
 581   0,                              /* tp_iternext */
 582   0,                              /* tp_methods */
 583   0,                              /* tp_members */
 584   linetable_entry_object_getset,  /* tp_getset */
 585   0,                              /* tp_base */
 586   0,                              /* tp_dict */
 587   0,                              /* tp_descr_get */
 588   0,                              /* tp_descr_set */
 589   0,                              /* tp_dictoffset */
 590   0,                              /* tp_init */
 591   0,                              /* tp_alloc */
 592 };