gdb/python/py-symbol.c

   1 /* Python interface to symbols.
   2
   3    Copyright (C) 2008-2019 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 "block.h"
  22 #include "frame.h"
  23 #include "symtab.h"
  24 #include "python-internal.h"
  25 #include "objfiles.h"
  26 #include "symfile.h"
  27
  28 typedef struct sympy_symbol_object {
  29   PyObject_HEAD
  30   /* The GDB symbol structure this object is wrapping.  */
  31   struct symbol *symbol;
  32   /* A symbol object is associated with an objfile, so keep track with
  33      doubly-linked list, rooted in the objfile.  This lets us
  34      invalidate the underlying struct symbol when the objfile is
  35      deleted.  */
  36   struct sympy_symbol_object *prev;
  37   struct sympy_symbol_object *next;
  38 } symbol_object;
  39
  40 /* Require a valid symbol.  All access to symbol_object->symbol should be
  41    gated by this call.  */
  42 #define SYMPY_REQUIRE_VALID(symbol_obj, symbol)         \
  43   do {                                                  \
  44     symbol = symbol_object_to_symbol (symbol_obj);      \
  45     if (symbol == NULL)                                 \
  46       {                                                 \
  47         PyErr_SetString (PyExc_RuntimeError,            \
  48                          _("Symbol is invalid."));      \
  49         return NULL;                                    \
  50       }                                                 \
  51   } while (0)
  52
  53 static const struct objfile_data *sympy_objfile_data_key;
  54
  55 static PyObject *
  56 sympy_str (PyObject *self)
  57 {
  58   PyObject *result;
  59   struct symbol *symbol = NULL;
  60
  61   SYMPY_REQUIRE_VALID (self, symbol);
  62
  63   result = PyString_FromString (SYMBOL_PRINT_NAME (symbol));
  64
  65   return result;
  66 }
  67
  68 static PyObject *
  69 sympy_get_type (PyObject *self, void *closure)
  70 {
  71   struct symbol *symbol = NULL;
  72
  73   SYMPY_REQUIRE_VALID (self, symbol);
  74
  75   if (SYMBOL_TYPE (symbol) == NULL)
  76     {
  77       Py_INCREF (Py_None);
  78       return Py_None;
  79     }
  80
  81   return type_to_type_object (SYMBOL_TYPE (symbol));
  82 }
  83
  84 static PyObject *
  85 sympy_get_symtab (PyObject *self, void *closure)
  86 {
  87   struct symbol *symbol = NULL;
  88
  89   SYMPY_REQUIRE_VALID (self, symbol);
  90
  91   if (!SYMBOL_OBJFILE_OWNED (symbol))
  92     Py_RETURN_NONE;
  93
  94   return symtab_to_symtab_object (symbol_symtab (symbol));
  95 }
  96
  97 static PyObject *
  98 sympy_get_name (PyObject *self, void *closure)
  99 {
 100   struct symbol *symbol = NULL;
 101
 102   SYMPY_REQUIRE_VALID (self, symbol);
 103
 104   return PyString_FromString (SYMBOL_NATURAL_NAME (symbol));
 105 }
 106
 107 static PyObject *
 108 sympy_get_linkage_name (PyObject *self, void *closure)
 109 {
 110   struct symbol *symbol = NULL;
 111
 112   SYMPY_REQUIRE_VALID (self, symbol);
 113
 114   return PyString_FromString (SYMBOL_LINKAGE_NAME (symbol));
 115 }
 116
 117 static PyObject *
 118 sympy_get_print_name (PyObject *self, void *closure)
 119 {
 120   struct symbol *symbol = NULL;
 121
 122   SYMPY_REQUIRE_VALID (self, symbol);
 123
 124   return sympy_str (self);
 125 }
 126
 127 static PyObject *
 128 sympy_get_addr_class (PyObject *self, void *closure)
 129 {
 130   struct symbol *symbol = NULL;
 131
 132   SYMPY_REQUIRE_VALID (self, symbol);
 133
 134   return PyInt_FromLong (SYMBOL_CLASS (symbol));
 135 }
 136
 137 static PyObject *
 138 sympy_is_argument (PyObject *self, void *closure)
 139 {
 140   struct symbol *symbol = NULL;
 141
 142   SYMPY_REQUIRE_VALID (self, symbol);
 143
 144   return PyBool_FromLong (SYMBOL_IS_ARGUMENT (symbol));
 145 }
 146
 147 static PyObject *
 148 sympy_is_constant (PyObject *self, void *closure)
 149 {
 150   struct symbol *symbol = NULL;
 151   enum address_class theclass;
 152
 153   SYMPY_REQUIRE_VALID (self, symbol);
 154
 155   theclass = SYMBOL_CLASS (symbol);
 156
 157   return PyBool_FromLong (theclass == LOC_CONST || theclass == LOC_CONST_BYTES);
 158 }
 159
 160 static PyObject *
 161 sympy_is_function (PyObject *self, void *closure)
 162 {
 163   struct symbol *symbol = NULL;
 164   enum address_class theclass;
 165
 166   SYMPY_REQUIRE_VALID (self, symbol);
 167
 168   theclass = SYMBOL_CLASS (symbol);
 169
 170   return PyBool_FromLong (theclass == LOC_BLOCK);
 171 }
 172
 173 static PyObject *
 174 sympy_is_variable (PyObject *self, void *closure)
 175 {
 176   struct symbol *symbol = NULL;
 177   enum address_class theclass;
 178
 179   SYMPY_REQUIRE_VALID (self, symbol);
 180
 181   theclass = SYMBOL_CLASS (symbol);
 182
 183   return PyBool_FromLong (!SYMBOL_IS_ARGUMENT (symbol)
 184                           && (theclass == LOC_LOCAL || theclass == LOC_REGISTER
 185                               || theclass == LOC_STATIC || theclass == LOC_COMPUTED
 186                               || theclass == LOC_OPTIMIZED_OUT));
 187 }
 188
 189 /* Implementation of gdb.Symbol.needs_frame -> Boolean.
 190    Returns true iff the symbol needs a frame for evaluation.  */
 191
 192 static PyObject *
 193 sympy_needs_frame (PyObject *self, void *closure)
 194 {
 195   struct symbol *symbol = NULL;
 196   int result = 0;
 197
 198   SYMPY_REQUIRE_VALID (self, symbol);
 199
 200   try
 201     {
 202       result = symbol_read_needs_frame (symbol);
 203     }
 204   catch (const gdb_exception &except)
 205     {
 206       GDB_PY_HANDLE_EXCEPTION (except);
 207     }
 208
 209   if (result)
 210     Py_RETURN_TRUE;
 211   Py_RETURN_FALSE;
 212 }
 213
 214 /* Implementation of gdb.Symbol.line -> int.
 215    Returns the line number at which the symbol was defined.  */
 216
 217 static PyObject *
 218 sympy_line (PyObject *self, void *closure)
 219 {
 220   struct symbol *symbol = NULL;
 221
 222   SYMPY_REQUIRE_VALID (self, symbol);
 223
 224   return PyInt_FromLong (SYMBOL_LINE (symbol));
 225 }
 226
 227 /* Implementation of gdb.Symbol.is_valid (self) -> Boolean.
 228    Returns True if this Symbol still exists in GDB.  */
 229
 230 static PyObject *
 231 sympy_is_valid (PyObject *self, PyObject *args)
 232 {
 233   struct symbol *symbol = NULL;
 234
 235   symbol = symbol_object_to_symbol (self);
 236   if (symbol == NULL)
 237     Py_RETURN_FALSE;
 238
 239   Py_RETURN_TRUE;
 240 }
 241
 242 /* Implementation of gdb.Symbol.value (self[, frame]) -> gdb.Value.  Returns
 243    the value of the symbol, or an error in various circumstances.  */
 244
 245 static PyObject *
 246 sympy_value (PyObject *self, PyObject *args)
 247 {
 248   struct symbol *symbol = NULL;
 249   struct frame_info *frame_info = NULL;
 250   PyObject *frame_obj = NULL;
 251   struct value *value = NULL;
 252
 253   if (!PyArg_ParseTuple (args, "|O", &frame_obj))
 254     return NULL;
 255
 256   if (frame_obj != NULL && !PyObject_TypeCheck (frame_obj, &frame_object_type))
 257     {
 258       PyErr_SetString (PyExc_TypeError, "argument is not a frame");
 259       return NULL;
 260     }
 261
 262   SYMPY_REQUIRE_VALID (self, symbol);
 263   if (SYMBOL_CLASS (symbol) == LOC_TYPEDEF)
 264     {
 265       PyErr_SetString (PyExc_TypeError, "cannot get the value of a typedef");
 266       return NULL;
 267     }
 268
 269   try
 270     {
 271       if (frame_obj != NULL)
 272         {
 273           frame_info = frame_object_to_frame_info (frame_obj);
 274           if (frame_info == NULL)
 275             error (_("invalid frame"));
 276         }
 277
 278       if (symbol_read_needs_frame (symbol) && frame_info == NULL)
 279         error (_("symbol requires a frame to compute its value"));
 280
 281       /* TODO: currently, we have no way to recover the block in which SYMBOL
 282          was found, so we have no block to pass to read_var_value.  This will
 283          yield an incorrect value when symbol is not local to FRAME_INFO (this
 284          can happen with nested functions).  */
 285       value = read_var_value (symbol, NULL, frame_info);
 286     }
 287   catch (const gdb_exception &except)
 288     {
 289       GDB_PY_HANDLE_EXCEPTION (except);
 290     }
 291
 292   return value_to_value_object (value);
 293 }
 294
 295 /* Given a symbol, and a symbol_object that has previously been
 296    allocated and initialized, populate the symbol_object with the
 297    struct symbol data.  Also, register the symbol_object life-cycle
 298    with the life-cycle of the object file associated with this
 299    symbol, if needed.  */
 300 static void
 301 set_symbol (symbol_object *obj, struct symbol *symbol)
 302 {
 303   obj->symbol = symbol;
 304   obj->prev = NULL;
 305   if (SYMBOL_OBJFILE_OWNED (symbol)
 306       && symbol_symtab (symbol) != NULL)
 307     {
 308       struct objfile *objfile = symbol_objfile (symbol);
 309
 310       obj->next = ((struct sympy_symbol_object *)
 311                    objfile_data (objfile, sympy_objfile_data_key));
 312       if (obj->next)
 313         obj->next->prev = obj;
 314       set_objfile_data (objfile, sympy_objfile_data_key, obj);
 315     }
 316   else
 317     obj->next = NULL;
 318 }
 319
 320 /* Create a new symbol object (gdb.Symbol) that encapsulates the struct
 321    symbol object from GDB.  */
 322 PyObject *
 323 symbol_to_symbol_object (struct symbol *sym)
 324 {
 325   symbol_object *sym_obj;
 326
 327   sym_obj = PyObject_New (symbol_object, &symbol_object_type);
 328   if (sym_obj)
 329     set_symbol (sym_obj, sym);
 330
 331   return (PyObject *) sym_obj;
 332 }
 333
 334 /* Return the symbol that is wrapped by this symbol object.  */
 335 struct symbol *
 336 symbol_object_to_symbol (PyObject *obj)
 337 {
 338   if (! PyObject_TypeCheck (obj, &symbol_object_type))
 339     return NULL;
 340   return ((symbol_object *) obj)->symbol;
 341 }
 342
 343 static void
 344 sympy_dealloc (PyObject *obj)
 345 {
 346   symbol_object *sym_obj = (symbol_object *) obj;
 347
 348   if (sym_obj->prev)
 349     sym_obj->prev->next = sym_obj->next;
 350   else if (sym_obj->symbol != NULL
 351            && SYMBOL_OBJFILE_OWNED (sym_obj->symbol)
 352            && symbol_symtab (sym_obj->symbol) != NULL)
 353     {
 354       set_objfile_data (symbol_objfile (sym_obj->symbol),
 355                         sympy_objfile_data_key, sym_obj->next);
 356     }
 357   if (sym_obj->next)
 358     sym_obj->next->prev = sym_obj->prev;
 359   sym_obj->symbol = NULL;
 360   Py_TYPE (obj)->tp_free (obj);
 361 }
 362
 363 /* Implementation of
 364    gdb.lookup_symbol (name [, block] [, domain]) -> (symbol, is_field_of_this)
 365    A tuple with 2 elements is always returned.  The first is the symbol
 366    object or None, the second is a boolean with the value of
 367    is_a_field_of_this (see comment in lookup_symbol_in_language).  */
 368
 369 PyObject *
 370 gdbpy_lookup_symbol (PyObject *self, PyObject *args, PyObject *kw)
 371 {
 372   int domain = VAR_DOMAIN;
 373   struct field_of_this_result is_a_field_of_this;
 374   const char *name;
 375   static const char *keywords[] = { "name", "block", "domain", NULL };
 376   struct symbol *symbol = NULL;
 377   PyObject *block_obj = NULL, *sym_obj, *bool_obj;
 378   const struct block *block = NULL;
 379
 380   if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|O!i", keywords, &name,
 381                                         &block_object_type, &block_obj,
 382                                         &domain))
 383     return NULL;
 384
 385   if (block_obj)
 386     block = block_object_to_block (block_obj);
 387   else
 388     {
 389       struct frame_info *selected_frame;
 390
 391       try
 392         {
 393           selected_frame = get_selected_frame (_("No frame selected."));
 394           block = get_frame_block (selected_frame, NULL);
 395         }
 396       catch (const gdb_exception &except)
 397         {
 398           GDB_PY_HANDLE_EXCEPTION (except);
 399         }
 400     }
 401
 402   try
 403     {
 404       symbol = lookup_symbol (name, block, (domain_enum) domain,
 405                               &is_a_field_of_this).symbol;
 406     }
 407   catch (const gdb_exception &except)
 408     {
 409       GDB_PY_HANDLE_EXCEPTION (except);
 410     }
 411
 412   gdbpy_ref<> ret_tuple (PyTuple_New (2));
 413   if (ret_tuple == NULL)
 414     return NULL;
 415
 416   if (symbol)
 417     {
 418       sym_obj = symbol_to_symbol_object (symbol);
 419       if (!sym_obj)
 420         return NULL;
 421     }
 422   else
 423     {
 424       sym_obj = Py_None;
 425       Py_INCREF (Py_None);
 426     }
 427   PyTuple_SET_ITEM (ret_tuple.get (), 0, sym_obj);
 428
 429   bool_obj = (is_a_field_of_this.type != NULL) ? Py_True : Py_False;
 430   Py_INCREF (bool_obj);
 431   PyTuple_SET_ITEM (ret_tuple.get (), 1, bool_obj);
 432
 433   return ret_tuple.release ();
 434 }
 435
 436 /* Implementation of
 437    gdb.lookup_global_symbol (name [, domain]) -> symbol or None.  */
 438
 439 PyObject *
 440 gdbpy_lookup_global_symbol (PyObject *self, PyObject *args, PyObject *kw)
 441 {
 442   int domain = VAR_DOMAIN;
 443   const char *name;
 444   static const char *keywords[] = { "name", "domain", NULL };
 445   struct symbol *symbol = NULL;
 446   PyObject *sym_obj;
 447
 448   if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|i", keywords, &name,
 449                                         &domain))
 450     return NULL;
 451
 452   try
 453     {
 454       symbol = lookup_global_symbol (name, NULL, (domain_enum) domain).symbol;
 455     }
 456   catch (const gdb_exception &except)
 457     {
 458       GDB_PY_HANDLE_EXCEPTION (except);
 459     }
 460
 461   if (symbol)
 462     {
 463       sym_obj = symbol_to_symbol_object (symbol);
 464       if (!sym_obj)
 465         return NULL;
 466     }
 467   else
 468     {
 469       sym_obj = Py_None;
 470       Py_INCREF (Py_None);
 471     }
 472
 473   return sym_obj;
 474 }
 475
 476 /* Implementation of
 477    gdb.lookup_static_symbol (name [, domain]) -> symbol or None.  */
 478
 479 PyObject *
 480 gdbpy_lookup_static_symbol (PyObject *self, PyObject *args, PyObject *kw)
 481 {
 482   const char *name;
 483   int domain = VAR_DOMAIN;
 484   static const char *keywords[] = { "name", "domain", NULL };
 485   struct symbol *symbol = NULL;
 486   PyObject *sym_obj;
 487
 488   if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|i", keywords, &name,
 489                                         &domain))
 490     return NULL;
 491
 492   /* In order to find static symbols associated with the "current" object
 493      file ahead of those from other object files, we first need to see if
 494      we can acquire a current block.  If this fails however, then we still
 495      want to search all static symbols, so don't throw an exception just
 496      yet.  */
 497   const struct block *block = NULL;
 498   try
 499     {
 500       struct frame_info *selected_frame
 501         = get_selected_frame (_("No frame selected."));
 502       block = get_frame_block (selected_frame, NULL);
 503     }
 504   catch (const gdb_exception &except)
 505     {
 506       /* Nothing.  */
 507     }
 508
 509   try
 510     {
 511       if (block != nullptr)
 512         symbol
 513           = lookup_symbol_in_static_block (name, block,
 514                                            (domain_enum) domain).symbol;
 515
 516       if (symbol == nullptr)
 517         symbol = lookup_static_symbol (name, (domain_enum) domain).symbol;
 518     }
 519   catch (const gdb_exception &except)
 520     {
 521       GDB_PY_HANDLE_EXCEPTION (except);
 522     }
 523
 524   if (symbol)
 525     {
 526       sym_obj = symbol_to_symbol_object (symbol);
 527       if (!sym_obj)
 528         return NULL;
 529     }
 530   else
 531     {
 532       sym_obj = Py_None;
 533       Py_INCREF (Py_None);
 534     }
 535
 536   return sym_obj;
 537 }
 538
 539 /* Implementation of
 540    gdb.lookup_static_symbols (name [, domain]) -> symbol list.
 541
 542    Returns a list of all static symbols matching NAME in DOMAIN.  */
 543
 544 PyObject *
 545 gdbpy_lookup_static_symbols (PyObject *self, PyObject *args, PyObject *kw)
 546 {
 547   const char *name;
 548   int domain = VAR_DOMAIN;
 549   static const char *keywords[] = { "name", "domain", NULL };
 550
 551   if (!gdb_PyArg_ParseTupleAndKeywords (args, kw, "s|i", keywords, &name,
 552                                         &domain))
 553     return NULL;
 554
 555   gdbpy_ref<> return_list (PyList_New (0));
 556   if (return_list == NULL)
 557     return NULL;
 558
 559   try
 560     {
 561       /* Expand any symtabs that contain potentially matching symbols.  */
 562       lookup_name_info lookup_name (name, symbol_name_match_type::FULL);
 563       expand_symtabs_matching (NULL, lookup_name, NULL, NULL, ALL_DOMAIN);
 564
 565       for (objfile *objfile : current_program_space->objfiles ())
 566         {
 567           for (compunit_symtab *cust : objfile->compunits ())
 568             {
 569               const struct blockvector *bv;
 570               const struct block *block;
 571
 572               bv = COMPUNIT_BLOCKVECTOR (cust);
 573               block = BLOCKVECTOR_BLOCK (bv, STATIC_BLOCK);
 574
 575               if (block != nullptr)
 576                 {
 577                   symbol *symbol = lookup_symbol_in_static_block
 578                     (name, block, (domain_enum) domain).symbol;
 579
 580                   if (symbol != nullptr)
 581                     {
 582                       PyObject *sym_obj
 583                         = symbol_to_symbol_object (symbol);
 584                       if (PyList_Append (return_list.get (), sym_obj) == -1)
 585                         return NULL;
 586                     }
 587                 }
 588             }
 589         }
 590     }
 591   catch (const gdb_exception &except)
 592     {
 593       GDB_PY_HANDLE_EXCEPTION (except);
 594     }
 595
 596   return return_list.release ();
 597 }
 598
 599 /* This function is called when an objfile is about to be freed.
 600    Invalidate the symbol as further actions on the symbol would result
 601    in bad data.  All access to obj->symbol should be gated by
 602    SYMPY_REQUIRE_VALID which will raise an exception on invalid
 603    symbols.  */
 604 static void
 605 del_objfile_symbols (struct objfile *objfile, void *datum)
 606 {
 607   symbol_object *obj = (symbol_object *) datum;
 608   while (obj)
 609     {
 610       symbol_object *next = obj->next;
 611
 612       obj->symbol = NULL;
 613       obj->next = NULL;
 614       obj->prev = NULL;
 615
 616       obj = next;
 617     }
 618 }
 619
 620 int
 621 gdbpy_initialize_symbols (void)
 622 {
 623   if (PyType_Ready (&symbol_object_type) < 0)
 624     return -1;
 625
 626   /* Register an objfile "free" callback so we can properly
 627      invalidate symbol when an object file that is about to be
 628      deleted.  */
 629   sympy_objfile_data_key
 630     = register_objfile_data_with_cleanup (NULL, del_objfile_symbols);
 631
 632   if (PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_UNDEF", LOC_UNDEF) < 0
 633       || PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_CONST",
 634                                   LOC_CONST) < 0
 635       || PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_STATIC",
 636                                   LOC_STATIC) < 0
 637       || PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_REGISTER",
 638                                   LOC_REGISTER) < 0
 639       || PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_ARG",
 640                                   LOC_ARG) < 0
 641       || PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_REF_ARG",
 642                                   LOC_REF_ARG) < 0
 643       || PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_LOCAL",
 644                                   LOC_LOCAL) < 0
 645       || PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_TYPEDEF",
 646                                   LOC_TYPEDEF) < 0
 647       || PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_LABEL",
 648                                   LOC_LABEL) < 0
 649       || PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_BLOCK",
 650                                   LOC_BLOCK) < 0
 651       || PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_CONST_BYTES",
 652                                   LOC_CONST_BYTES) < 0
 653       || PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_UNRESOLVED",
 654                                   LOC_UNRESOLVED) < 0
 655       || PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_OPTIMIZED_OUT",
 656                                   LOC_OPTIMIZED_OUT) < 0
 657       || PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_COMPUTED",
 658                                   LOC_COMPUTED) < 0
 659       || PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_COMMON_BLOCK",
 660                                   LOC_COMMON_BLOCK) < 0
 661       || PyModule_AddIntConstant (gdb_module, "SYMBOL_LOC_REGPARM_ADDR",
 662                                   LOC_REGPARM_ADDR) < 0
 663       || PyModule_AddIntConstant (gdb_module, "SYMBOL_UNDEF_DOMAIN",
 664                                   UNDEF_DOMAIN) < 0
 665       || PyModule_AddIntConstant (gdb_module, "SYMBOL_VAR_DOMAIN",
 666                                   VAR_DOMAIN) < 0
 667       || PyModule_AddIntConstant (gdb_module, "SYMBOL_STRUCT_DOMAIN",
 668                                   STRUCT_DOMAIN) < 0
 669       || PyModule_AddIntConstant (gdb_module, "SYMBOL_MODULE_DOMAIN",
 670                                   MODULE_DOMAIN) < 0
 671       || PyModule_AddIntConstant (gdb_module, "SYMBOL_COMMON_BLOCK_DOMAIN",
 672                                   COMMON_BLOCK_DOMAIN) < 0)
 673     return -1;
 674
 675   /* These remain defined for compatibility, but as they were never
 676      correct, they are no longer documented.  Eventually we can remove
 677      them.  These exist because at one time, enum search_domain and
 678      enum domain_enum_tag were combined -- but different values were
 679      used differently.  Here we try to give them values that will make
 680      sense if they are passed to gdb.lookup_symbol.  */
 681   if (PyModule_AddIntConstant (gdb_module, "SYMBOL_VARIABLES_DOMAIN",
 682                                VAR_DOMAIN) < 0
 683       || PyModule_AddIntConstant (gdb_module, "SYMBOL_FUNCTIONS_DOMAIN",
 684                                   VAR_DOMAIN) < 0
 685       || PyModule_AddIntConstant (gdb_module, "SYMBOL_TYPES_DOMAIN",
 686                                   VAR_DOMAIN) < 0)
 687     return -1;
 688
 689   return gdb_pymodule_addobject (gdb_module, "Symbol",
 690                                  (PyObject *) &symbol_object_type);
 691 }
 692
 693 \f
 694
 695 static gdb_PyGetSetDef symbol_object_getset[] = {
 696   { "type", sympy_get_type, NULL,
 697     "Type of the symbol.", NULL },
 698   { "symtab", sympy_get_symtab, NULL,
 699     "Symbol table in which the symbol appears.", NULL },
 700   { "name", sympy_get_name, NULL,
 701     "Name of the symbol, as it appears in the source code.", NULL },
 702   { "linkage_name", sympy_get_linkage_name, NULL,
 703     "Name of the symbol, as used by the linker (i.e., may be mangled).",
 704     NULL },
 705   { "print_name", sympy_get_print_name, NULL,
 706     "Name of the symbol in a form suitable for output.\n\
 707 This is either name or linkage_name, depending on whether the user asked GDB\n\
 708 to display demangled or mangled names.", NULL },
 709   { "addr_class", sympy_get_addr_class, NULL, "Address class of the symbol." },
 710   { "is_argument", sympy_is_argument, NULL,
 711     "True if the symbol is an argument of a function." },
 712   { "is_constant", sympy_is_constant, NULL,
 713     "True if the symbol is a constant." },
 714   { "is_function", sympy_is_function, NULL,
 715     "True if the symbol is a function or method." },
 716   { "is_variable", sympy_is_variable, NULL,
 717     "True if the symbol is a variable." },
 718   { "needs_frame", sympy_needs_frame, NULL,
 719     "True if the symbol requires a frame for evaluation." },
 720   { "line", sympy_line, NULL,
 721     "The source line number at which the symbol was defined." },
 722   { NULL }  /* Sentinel */
 723 };
 724
 725 static PyMethodDef symbol_object_methods[] = {
 726   { "is_valid", sympy_is_valid, METH_NOARGS,
 727     "is_valid () -> Boolean.\n\
 728 Return true if this symbol is valid, false if not." },
 729   { "value", sympy_value, METH_VARARGS,
 730     "value ([frame]) -> gdb.Value\n\
 731 Return the value of the symbol." },
 732   {NULL}  /* Sentinel */
 733 };
 734
 735 PyTypeObject symbol_object_type = {
 736   PyVarObject_HEAD_INIT (NULL, 0)
 737   "gdb.Symbol",                   /*tp_name*/
 738   sizeof (symbol_object),         /*tp_basicsize*/
 739   0,                              /*tp_itemsize*/
 740   sympy_dealloc,                  /*tp_dealloc*/
 741   0,                              /*tp_print*/
 742   0,                              /*tp_getattr*/
 743   0,                              /*tp_setattr*/
 744   0,                              /*tp_compare*/
 745   0,                              /*tp_repr*/
 746   0,                              /*tp_as_number*/
 747   0,                              /*tp_as_sequence*/
 748   0,                              /*tp_as_mapping*/
 749   0,                              /*tp_hash */
 750   0,                              /*tp_call*/
 751   sympy_str,                      /*tp_str*/
 752   0,                              /*tp_getattro*/
 753   0,                              /*tp_setattro*/
 754   0,                              /*tp_as_buffer*/
 755   Py_TPFLAGS_DEFAULT,             /*tp_flags*/
 756   "GDB symbol object",            /*tp_doc */
 757   0,                              /*tp_traverse */
 758   0,                              /*tp_clear */
 759   0,                              /*tp_richcompare */
 760   0,                              /*tp_weaklistoffset */
 761   0,                              /*tp_iter */
 762   0,                              /*tp_iternext */
 763   symbol_object_methods,          /*tp_methods */
 764   0,                              /*tp_members */
 765   symbol_object_getset            /*tp_getset */
 766 };