gdb/python/py-symtab.c

   1 /* Python interface to symbol tables.
   2
   3    Copyright (C) 2008-2012 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 "charset.h"
  22 #include "symtab.h"
  23 #include "source.h"
  24 #include "python-internal.h"
  25 #include "objfiles.h"
  26 #include "block.h"
  27
  28 typedef struct stpy_symtab_object {
  29   PyObject_HEAD
  30   /* The GDB Symbol table structure.  */
  31   struct symtab *symtab;
  32   /* A symtab object is associated with an objfile, so keep track with
  33      a doubly-linked list, rooted in the objfile.  This allows
  34      invalidation of the underlying struct symtab when the objfile is
  35      deleted.  */
  36   struct stpy_symtab_object *prev;
  37   struct stpy_symtab_object *next;
  38 } symtab_object;
  39
  40 static PyTypeObject symtab_object_type;
  41 static const struct objfile_data *stpy_objfile_data_key;
  42
  43 /* Require a valid symbol table.  All access to symtab_object->symtab
  44    should be gated by this call.  */
  45 #define STPY_REQUIRE_VALID(symtab_obj, symtab)           \
  46   do {                                                   \
  47     symtab = symtab_object_to_symtab (symtab_obj);       \
  48     if (symtab == NULL)                                  \
  49       {                                                  \
  50         PyErr_SetString (PyExc_RuntimeError,             \
  51                          _("Symbol Table is invalid.")); \
  52         return NULL;                                     \
  53       }                                                  \
  54   } while (0)
  55
  56 typedef struct salpy_sal_object {
  57   PyObject_HEAD
  58   /* The GDB Symbol table structure.  */
  59   symtab_object *symtab;
  60   /* The GDB Symbol table and line structure.  */
  61   struct symtab_and_line *sal;
  62   /* A Symtab and line object is associated with an objfile, so keep
  63      track with a doubly-linked list, rooted in the objfile.  This
  64      allows invalidation of the underlying struct symtab_and_line
  65      when the objfile is deleted.  */
  66   struct salpy_sal_object *prev;
  67   struct salpy_sal_object *next;
  68 } sal_object;
  69
  70 static PyTypeObject sal_object_type;
  71 static const struct objfile_data *salpy_objfile_data_key;
  72
  73 /* Require a valid symbol table and line object.  All access to
  74    sal_object->sal should be gated by this call.  */
  75 #define SALPY_REQUIRE_VALID(sal_obj, sal)                               \
  76   do {                                                                  \
  77     sal = sal_object_to_symtab_and_line (sal_obj);                      \
  78     if (sal == NULL)                                                    \
  79       {                                                                 \
  80           PyErr_SetString (PyExc_RuntimeError,                          \
  81                            _("Symbol Table and Line is invalid."));     \
  82           return NULL;                                                  \
  83         }                                                               \
  84   } while (0)
  85
  86 static PyObject *
  87 stpy_str (PyObject *self)
  88 {
  89   PyObject *result;
  90   struct symtab *symtab = NULL;
  91
  92   STPY_REQUIRE_VALID (self, symtab);
  93
  94   result = PyString_FromString (symtab->filename);
  95
  96   return result;
  97 }
  98
  99 static PyObject *
 100 stpy_get_filename (PyObject *self, void *closure)
 101 {
 102   PyObject *str_obj;
 103   struct symtab *symtab = NULL;
 104
 105   STPY_REQUIRE_VALID (self, symtab);
 106
 107   str_obj = PyString_Decode (symtab->filename,
 108                              strlen (symtab->filename),
 109                              host_charset (), NULL);
 110   return str_obj;
 111 }
 112
 113 static PyObject *
 114 stpy_get_objfile (PyObject *self, void *closure)
 115 {
 116   struct symtab *symtab = NULL;
 117   PyObject *result;
 118
 119   STPY_REQUIRE_VALID (self, symtab);
 120
 121   result = objfile_to_objfile_object (symtab->objfile);
 122   Py_XINCREF (result);
 123   return result;
 124 }
 125
 126 static PyObject *
 127 stpy_fullname (PyObject *self, PyObject *args)
 128 {
 129   const char *fullname;
 130   struct symtab *symtab = NULL;
 131
 132   STPY_REQUIRE_VALID (self, symtab);
 133
 134   fullname = symtab_to_fullname (symtab);
 135   if (fullname)
 136     return PyString_Decode (fullname, strlen (fullname),
 137                             host_charset (), NULL);
 138
 139   Py_RETURN_NONE;
 140 }
 141
 142 /* Implementation of gdb.Symtab.is_valid (self) -> Boolean.
 143    Returns True if this Symbol table still exists in GDB.  */
 144
 145 static PyObject *
 146 stpy_is_valid (PyObject *self, PyObject *args)
 147 {
 148   struct symtab *symtab = NULL;
 149
 150   symtab = symtab_object_to_symtab (self);
 151   if (symtab == NULL)
 152     Py_RETURN_FALSE;
 153
 154   Py_RETURN_TRUE;
 155 }
 156
 157 /* Return the GLOBAL_BLOCK of the underlying symtab.  */
 158
 159 static PyObject *
 160 stpy_global_block (PyObject *self, PyObject *args)
 161 {
 162   struct symtab *symtab = NULL;
 163   struct block *block = NULL;
 164   struct blockvector *blockvector;
 165
 166   STPY_REQUIRE_VALID (self, symtab);
 167
 168   blockvector = BLOCKVECTOR (symtab);
 169   block = BLOCKVECTOR_BLOCK (blockvector, GLOBAL_BLOCK);
 170   return block_to_block_object (block, symtab->objfile);
 171 }
 172
 173 /* Return the STATIC_BLOCK of the underlying symtab.  */
 174
 175 static PyObject *
 176 stpy_static_block (PyObject *self, PyObject *args)
 177 {
 178   struct symtab *symtab = NULL;
 179   struct block *block = NULL;
 180   struct blockvector *blockvector;
 181
 182   STPY_REQUIRE_VALID (self, symtab);
 183
 184   blockvector = BLOCKVECTOR (symtab);
 185   block = BLOCKVECTOR_BLOCK (blockvector, STATIC_BLOCK);
 186   return block_to_block_object (block, symtab->objfile);
 187 }
 188
 189 static PyObject *
 190 salpy_str (PyObject *self)
 191 {
 192   char *s, *filename;
 193   sal_object *sal_obj;
 194   PyObject *result;
 195   struct symtab_and_line *sal = NULL;
 196
 197   SALPY_REQUIRE_VALID (self, sal);
 198
 199   sal_obj = (sal_object *) self;
 200   filename = (sal_obj->symtab == (symtab_object *) Py_None)
 201     ? "<unknown>" : sal_obj->symtab->symtab->filename;
 202
 203   s = xstrprintf ("symbol and line for %s, line %d", filename,
 204                   sal->line);
 205
 206   result = PyString_FromString (s);
 207   xfree (s);
 208
 209   return result;
 210 }
 211
 212 static void
 213 stpy_dealloc (PyObject *obj)
 214 {
 215   symtab_object *symtab = (symtab_object *) obj;
 216
 217   if (symtab->prev)
 218     symtab->prev->next = symtab->next;
 219   else if (symtab->symtab)
 220     {
 221       set_objfile_data (symtab->symtab->objfile,
 222                         stpy_objfile_data_key, symtab->next);
 223     }
 224   if (symtab->next)
 225     symtab->next->prev = symtab->prev;
 226   symtab->symtab = NULL;
 227 }
 228
 229
 230 static PyObject *
 231 salpy_get_pc (PyObject *self, void *closure)
 232 {
 233   struct symtab_and_line *sal = NULL;
 234
 235   SALPY_REQUIRE_VALID (self, sal);
 236
 237   return gdb_py_long_from_ulongest (sal->pc);
 238 }
 239
 240 /* Implementation of the get method for the 'last' attribute of
 241    gdb.Symtab_and_line.  */
 242
 243 static PyObject *
 244 salpy_get_last (PyObject *self, void *closure)
 245 {
 246   struct symtab_and_line *sal = NULL;
 247
 248   SALPY_REQUIRE_VALID (self, sal);
 249
 250   if (sal->end > 0)
 251     return gdb_py_long_from_ulongest (sal->end - 1);
 252   else
 253     Py_RETURN_NONE;
 254 }
 255
 256 static PyObject *
 257 salpy_get_line (PyObject *self, void *closure)
 258 {
 259   struct symtab_and_line *sal = NULL;
 260
 261   SALPY_REQUIRE_VALID (self, sal);
 262
 263   return PyInt_FromLong (sal->line);
 264 }
 265
 266 static PyObject *
 267 salpy_get_symtab (PyObject *self, void *closure)
 268 {
 269   struct symtab_and_line *sal;
 270   sal_object *self_sal = (sal_object *) self;
 271
 272   SALPY_REQUIRE_VALID (self, sal);
 273
 274   Py_INCREF (self_sal->symtab);
 275
 276   return (PyObject *) self_sal->symtab;
 277 }
 278
 279 /* Implementation of gdb.Symtab_and_line.is_valid (self) -> Boolean.
 280    Returns True if this Symbol table and line object still exists GDB.  */
 281
 282 static PyObject *
 283 salpy_is_valid (PyObject *self, PyObject *args)
 284 {
 285   struct symtab_and_line *sal;
 286
 287   sal = sal_object_to_symtab_and_line (self);
 288   if (sal == NULL)
 289     Py_RETURN_FALSE;
 290
 291   Py_RETURN_TRUE;
 292 }
 293
 294 static void
 295 salpy_dealloc (PyObject *self)
 296 {
 297   sal_object *self_sal = (sal_object *) self;
 298
 299   if (self_sal->prev)
 300     self_sal->prev->next = self_sal->next;
 301   else if (self_sal->symtab != (symtab_object * ) Py_None)
 302     set_objfile_data (self_sal->symtab->symtab->objfile,
 303                       salpy_objfile_data_key, self_sal->next);
 304
 305   if (self_sal->next)
 306     self_sal->next->prev = self_sal->prev;
 307
 308   Py_DECREF (self_sal->symtab);
 309   xfree (self_sal->sal);
 310   Py_TYPE (self)->tp_free (self);
 311 }
 312
 313 /* Given a sal, and a sal_object that has previously been allocated
 314    and initialized, populate the sal_object with the struct sal data.
 315    Also, register the sal_object life-cycle with the life-cycle of the
 316    object file associated with this sal, if needed.  If a failure
 317    occurs during the sal population, this function will return
 318    NULL.  */
 319 static int
 320 set_sal (sal_object *sal_obj, struct symtab_and_line sal)
 321 {
 322   symtab_object *symtab_obj;
 323
 324   if (sal.symtab)
 325     {
 326       symtab_obj = (symtab_object *) symtab_to_symtab_object  (sal.symtab);
 327       /* If a symtab existed in the sal, but it cannot be duplicated,
 328          we exit.  */
 329       if (symtab_obj == NULL)
 330         return 0;
 331     }
 332   else
 333     {
 334       symtab_obj = (symtab_object *) Py_None;
 335       Py_INCREF (Py_None);
 336     }
 337
 338   sal_obj->sal = xmemdup (&sal, sizeof (struct symtab_and_line),
 339                           sizeof (struct symtab_and_line));
 340   sal_obj->symtab = symtab_obj;
 341   sal_obj->prev = NULL;
 342
 343   /* If the SAL does not have a symtab, we do not add it to the
 344      objfile cleanup observer linked list.  */
 345   if (sal_obj->symtab != (symtab_object *)Py_None)
 346     {
 347       sal_obj->next = objfile_data (sal_obj->symtab->symtab->objfile,
 348                                     salpy_objfile_data_key);
 349       if (sal_obj->next)
 350         sal_obj->next->prev = sal_obj;
 351
 352       set_objfile_data (sal_obj->symtab->symtab->objfile,
 353                         salpy_objfile_data_key, sal_obj);
 354     }
 355   else
 356     sal_obj->next = NULL;
 357
 358   return 1;
 359 }
 360
 361 /* Given a symtab, and a symtab_object that has previously been
 362    allocated and initialized, populate the symtab_object with the
 363    struct symtab data.  Also, register the symtab_object life-cycle
 364    with the life-cycle of the object file associated with this
 365    symtab, if needed.  */
 366 static void
 367 set_symtab (symtab_object *obj, struct symtab *symtab)
 368 {
 369   obj->symtab = symtab;
 370   obj->prev = NULL;
 371   if (symtab)
 372     {
 373       obj->next = objfile_data (symtab->objfile, stpy_objfile_data_key);
 374       if (obj->next)
 375         obj->next->prev = obj;
 376       set_objfile_data (symtab->objfile, stpy_objfile_data_key, obj);
 377     }
 378   else
 379     obj->next = NULL;
 380 }
 381
 382 /* Create a new symbol table (gdb.Symtab) object that encapsulates the
 383    symtab structure from GDB.  */
 384 PyObject *
 385 symtab_to_symtab_object (struct symtab *symtab)
 386 {
 387   symtab_object *symtab_obj;
 388
 389   symtab_obj = PyObject_New (symtab_object, &symtab_object_type);
 390   if (symtab_obj)
 391     set_symtab (symtab_obj, symtab);
 392
 393   return (PyObject *) symtab_obj;
 394 }
 395
 396 /* Create a new symtab and line (gdb.Symtab_and_line) object
 397    that encapsulates the symtab_and_line structure from GDB.  */
 398 PyObject *
 399 symtab_and_line_to_sal_object (struct symtab_and_line sal)
 400
 401 {
 402   sal_object *sal_obj;
 403   int success = 0;
 404
 405   sal_obj = PyObject_New (sal_object, &sal_object_type);
 406   if (sal_obj)
 407     {
 408       success = set_sal (sal_obj, sal);
 409       if (!success)
 410         {
 411           Py_DECREF (sal_obj);
 412           return NULL;
 413         }
 414     }
 415
 416   return (PyObject *) sal_obj;
 417 }
 418
 419 /* Return struct symtab_and_line reference that is wrapped by this
 420    object.  */
 421 struct symtab_and_line *
 422 sal_object_to_symtab_and_line (PyObject *obj)
 423 {
 424   if (! PyObject_TypeCheck (obj, &sal_object_type))
 425     return NULL;
 426   return ((sal_object *) obj)->sal;
 427 }
 428
 429 /* Return struct symtab reference that is wrapped by this object.  */
 430 struct symtab *
 431 symtab_object_to_symtab (PyObject *obj)
 432 {
 433   if (! PyObject_TypeCheck (obj, &symtab_object_type))
 434     return NULL;
 435   return ((symtab_object *) obj)->symtab;
 436 }
 437
 438 /* This function is called when an objfile is about to be freed.
 439    Invalidate the symbol table as further actions on the symbol table
 440    would result in bad data.  All access to obj->symtab should be
 441    gated by STPY_REQUIRE_VALID which will raise an exception on
 442    invalid symbol tables.  */
 443 static void
 444 del_objfile_symtab (struct objfile *objfile, void *datum)
 445 {
 446   symtab_object *obj = datum;
 447
 448   while (obj)
 449     {
 450       symtab_object *next = obj->next;
 451
 452       obj->symtab = NULL;
 453       obj->next = NULL;
 454       obj->prev = NULL;
 455       obj = next;
 456     }
 457 }
 458
 459 /* This function is called when an objfile is about to be freed.
 460    Invalidate the sal object as further actions on the sal
 461    would result in bad data.  All access to obj->sal should be
 462    gated by SALPY_REQUIRE_VALID which will raise an exception on
 463    invalid symbol table and line objects.  */
 464 static void
 465 del_objfile_sal (struct objfile *objfile, void *datum)
 466 {
 467   sal_object *obj = datum;
 468
 469   while (obj)
 470     {
 471       sal_object *next = obj->next;
 472
 473       Py_DECREF (obj->symtab);
 474       obj->symtab = (symtab_object *) Py_None;
 475       Py_INCREF (Py_None);
 476
 477       obj->next = NULL;
 478       obj->prev = NULL;
 479       xfree (obj->sal);
 480       obj->sal = NULL;
 481
 482       obj = next;
 483     }
 484 }
 485
 486 void
 487 gdbpy_initialize_symtabs (void)
 488 {
 489   symtab_object_type.tp_new = PyType_GenericNew;
 490   if (PyType_Ready (&symtab_object_type) < 0)
 491     return;
 492
 493   sal_object_type.tp_new = PyType_GenericNew;
 494   if (PyType_Ready (&sal_object_type) < 0)
 495     return;
 496
 497   /* Register an objfile "free" callback so we can properly
 498      invalidate symbol tables, and symbol table and line data
 499      structures when an object file that is about to be
 500      deleted.  */
 501   stpy_objfile_data_key
 502     = register_objfile_data_with_cleanup (NULL, del_objfile_symtab);
 503   salpy_objfile_data_key
 504     = register_objfile_data_with_cleanup (NULL, del_objfile_sal);
 505
 506   Py_INCREF (&symtab_object_type);
 507   PyModule_AddObject (gdb_module, "Symtab",
 508                       (PyObject *) &symtab_object_type);
 509
 510   Py_INCREF (&sal_object_type);
 511   PyModule_AddObject (gdb_module, "Symtab_and_line",
 512                       (PyObject *) &sal_object_type);
 513 }
 514
 515 \f
 516
 517 static PyGetSetDef symtab_object_getset[] = {
 518   { "filename", stpy_get_filename, NULL,
 519     "The symbol table's source filename.", NULL },
 520   { "objfile", stpy_get_objfile, NULL, "The symtab's objfile.",
 521     NULL },
 522   {NULL}  /* Sentinel */
 523 };
 524
 525 static PyMethodDef symtab_object_methods[] = {
 526   { "is_valid", stpy_is_valid, METH_NOARGS,
 527     "is_valid () -> Boolean.\n\
 528 Return true if this symbol table is valid, false if not." },
 529   { "fullname", stpy_fullname, METH_NOARGS,
 530     "fullname () -> String.\n\
 531 Return the symtab's full source filename." },
 532   { "global_block", stpy_global_block, METH_NOARGS,
 533     "global_block () -> gdb.Block.\n\
 534 Return the global block of the symbol table." },
 535   { "static_block", stpy_static_block, METH_NOARGS,
 536     "static_block () -> gdb.Block.\n\
 537 Return the static block of the symbol table." },
 538   {NULL}  /* Sentinel */
 539 };
 540
 541 static PyTypeObject symtab_object_type = {
 542   PyVarObject_HEAD_INIT (NULL, 0)
 543   "gdb.Symtab",                   /*tp_name*/
 544   sizeof (symtab_object),         /*tp_basicsize*/
 545   0,                              /*tp_itemsize*/
 546   stpy_dealloc,                   /*tp_dealloc*/
 547   0,                              /*tp_print*/
 548   0,                              /*tp_getattr*/
 549   0,                              /*tp_setattr*/
 550   0,                              /*tp_compare*/
 551   0,                              /*tp_repr*/
 552   0,                              /*tp_as_number*/
 553   0,                              /*tp_as_sequence*/
 554   0,                              /*tp_as_mapping*/
 555   0,                              /*tp_hash */
 556   0,                              /*tp_call*/
 557   stpy_str,                       /*tp_str*/
 558   0,                              /*tp_getattro*/
 559   0,                              /*tp_setattro*/
 560   0,                              /*tp_as_buffer*/
 561   Py_TPFLAGS_DEFAULT,             /*tp_flags*/
 562   "GDB symtab object",            /*tp_doc */
 563   0,                              /*tp_traverse */
 564   0,                              /*tp_clear */
 565   0,                              /*tp_richcompare */
 566   0,                              /*tp_weaklistoffset */
 567   0,                              /*tp_iter */
 568   0,                              /*tp_iternext */
 569   symtab_object_methods,          /*tp_methods */
 570   0,                              /*tp_members */
 571   symtab_object_getset            /*tp_getset */
 572 };
 573
 574 static PyGetSetDef sal_object_getset[] = {
 575   { "symtab", salpy_get_symtab, NULL, "Symtab object.", NULL },
 576   { "pc", salpy_get_pc, NULL, "Return the symtab_and_line's pc.", NULL },
 577   { "last", salpy_get_last, NULL,
 578     "Return the symtab_and_line's last address.", NULL },
 579   { "line", salpy_get_line, NULL,
 580     "Return the symtab_and_line's line.", NULL },
 581   {NULL}  /* Sentinel */
 582 };
 583
 584 static PyMethodDef sal_object_methods[] = {
 585   { "is_valid", salpy_is_valid, METH_NOARGS,
 586     "is_valid () -> Boolean.\n\
 587 Return true if this symbol table and line is valid, false if not." },
 588   {NULL}  /* Sentinel */
 589 };
 590
 591 static PyTypeObject sal_object_type = {
 592   PyVarObject_HEAD_INIT (NULL, 0)
 593   "gdb.Symtab_and_line",          /*tp_name*/
 594   sizeof (sal_object),            /*tp_basicsize*/
 595   0,                              /*tp_itemsize*/
 596   salpy_dealloc,                  /*tp_dealloc*/
 597   0,                              /*tp_print*/
 598   0,                              /*tp_getattr*/
 599   0,                              /*tp_setattr*/
 600   0,                              /*tp_compare*/
 601   0,                              /*tp_repr*/
 602   0,                              /*tp_as_number*/
 603   0,                              /*tp_as_sequence*/
 604   0,                              /*tp_as_mapping*/
 605   0,                              /*tp_hash */
 606   0,                              /*tp_call*/
 607   salpy_str,                      /*tp_str*/
 608   0,                              /*tp_getattro*/
 609   0,                              /*tp_setattro*/
 610   0,                              /*tp_as_buffer*/
 611   Py_TPFLAGS_DEFAULT,             /*tp_flags*/
 612   "GDB symtab_and_line object",   /*tp_doc */
 613   0,                              /*tp_traverse */
 614   0,                              /*tp_clear */
 615   0,                              /*tp_richcompare */
 616   0,                              /*tp_weaklistoffset */
 617   0,                              /*tp_iter */
 618   0,                              /*tp_iternext */
 619   sal_object_methods,             /*tp_methods */
 620   0,                              /*tp_members */
 621   sal_object_getset               /*tp_getset */
 622 };