| 1 | /* Python interface to blocks. |
| 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 "dictionary.h" |
| 23 | #include "symtab.h" |
| 24 | #include "python-internal.h" |
| 25 | #include "objfiles.h" |
| 26 | |
| 27 | typedef struct blpy_block_object { |
| 28 | PyObject_HEAD |
| 29 | /* The GDB block structure that represents a frame's code block. */ |
| 30 | const struct block *block; |
| 31 | /* The backing object file. There is no direct relationship in GDB |
| 32 | between a block and an object file. When a block is created also |
| 33 | store a pointer to the object file for later use. */ |
| 34 | struct objfile *objfile; |
| 35 | /* Keep track of all blocks with a doubly-linked list. Needed for |
| 36 | block invalidation if the source object file has been freed. */ |
| 37 | struct blpy_block_object *prev; |
| 38 | struct blpy_block_object *next; |
| 39 | } block_object; |
| 40 | |
| 41 | typedef struct { |
| 42 | PyObject_HEAD |
| 43 | /* The block. */ |
| 44 | const struct block *block; |
| 45 | /* The iterator for that block. */ |
| 46 | struct block_iterator iter; |
| 47 | /* Has the iterator been initialized flag. */ |
| 48 | int initialized_p; |
| 49 | /* Pointer back to the original source block object. Needed to |
| 50 | check if the block is still valid, and has not been invalidated |
| 51 | when an object file has been freed. */ |
| 52 | struct blpy_block_object *source; |
| 53 | } block_syms_iterator_object; |
| 54 | |
| 55 | /* Require a valid block. All access to block_object->block should be |
| 56 | gated by this call. */ |
| 57 | #define BLPY_REQUIRE_VALID(block_obj, block) \ |
| 58 | do { \ |
| 59 | block = block_object_to_block (block_obj); \ |
| 60 | if (block == NULL) \ |
| 61 | { \ |
| 62 | PyErr_SetString (PyExc_RuntimeError, \ |
| 63 | _("Block is invalid.")); \ |
| 64 | return NULL; \ |
| 65 | } \ |
| 66 | } while (0) |
| 67 | |
| 68 | /* Require a valid block. This macro is called during block iterator |
| 69 | creation, and at each next call. */ |
| 70 | #define BLPY_ITER_REQUIRE_VALID(block_obj) \ |
| 71 | do { \ |
| 72 | if (block_obj->block == NULL) \ |
| 73 | { \ |
| 74 | PyErr_SetString (PyExc_RuntimeError, \ |
| 75 | _("Source block for iterator is invalid.")); \ |
| 76 | return NULL; \ |
| 77 | } \ |
| 78 | } while (0) |
| 79 | |
| 80 | extern PyTypeObject block_syms_iterator_object_type |
| 81 | CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("block_syms_iterator_object"); |
| 82 | static const struct objfile_data *blpy_objfile_data_key; |
| 83 | |
| 84 | static PyObject * |
| 85 | blpy_iter (PyObject *self) |
| 86 | { |
| 87 | block_syms_iterator_object *block_iter_obj; |
| 88 | const struct block *block = NULL; |
| 89 | |
| 90 | BLPY_REQUIRE_VALID (self, block); |
| 91 | |
| 92 | block_iter_obj = PyObject_New (block_syms_iterator_object, |
| 93 | &block_syms_iterator_object_type); |
| 94 | if (block_iter_obj == NULL) |
| 95 | return NULL; |
| 96 | |
| 97 | block_iter_obj->block = block; |
| 98 | block_iter_obj->initialized_p = 0; |
| 99 | Py_INCREF (self); |
| 100 | block_iter_obj->source = (block_object *) self; |
| 101 | |
| 102 | return (PyObject *) block_iter_obj; |
| 103 | } |
| 104 | |
| 105 | static PyObject * |
| 106 | blpy_get_start (PyObject *self, void *closure) |
| 107 | { |
| 108 | const struct block *block = NULL; |
| 109 | |
| 110 | BLPY_REQUIRE_VALID (self, block); |
| 111 | |
| 112 | return gdb_py_object_from_ulongest (BLOCK_START (block)).release (); |
| 113 | } |
| 114 | |
| 115 | static PyObject * |
| 116 | blpy_get_end (PyObject *self, void *closure) |
| 117 | { |
| 118 | const struct block *block = NULL; |
| 119 | |
| 120 | BLPY_REQUIRE_VALID (self, block); |
| 121 | |
| 122 | return gdb_py_object_from_ulongest (BLOCK_END (block)).release (); |
| 123 | } |
| 124 | |
| 125 | static PyObject * |
| 126 | blpy_get_function (PyObject *self, void *closure) |
| 127 | { |
| 128 | struct symbol *sym; |
| 129 | const struct block *block; |
| 130 | |
| 131 | BLPY_REQUIRE_VALID (self, block); |
| 132 | |
| 133 | sym = BLOCK_FUNCTION (block); |
| 134 | if (sym) |
| 135 | return symbol_to_symbol_object (sym); |
| 136 | |
| 137 | Py_RETURN_NONE; |
| 138 | } |
| 139 | |
| 140 | static PyObject * |
| 141 | blpy_get_superblock (PyObject *self, void *closure) |
| 142 | { |
| 143 | const struct block *block; |
| 144 | const struct block *super_block; |
| 145 | block_object *self_obj = (block_object *) self; |
| 146 | |
| 147 | BLPY_REQUIRE_VALID (self, block); |
| 148 | |
| 149 | super_block = BLOCK_SUPERBLOCK (block); |
| 150 | if (super_block) |
| 151 | return block_to_block_object (super_block, self_obj->objfile); |
| 152 | |
| 153 | Py_RETURN_NONE; |
| 154 | } |
| 155 | |
| 156 | /* Return the global block associated to this block. */ |
| 157 | |
| 158 | static PyObject * |
| 159 | blpy_get_global_block (PyObject *self, void *closure) |
| 160 | { |
| 161 | const struct block *block; |
| 162 | const struct block *global_block; |
| 163 | block_object *self_obj = (block_object *) self; |
| 164 | |
| 165 | BLPY_REQUIRE_VALID (self, block); |
| 166 | |
| 167 | global_block = block_global_block (block); |
| 168 | |
| 169 | return block_to_block_object (global_block, |
| 170 | self_obj->objfile); |
| 171 | |
| 172 | } |
| 173 | |
| 174 | /* Return the static block associated to this block. Return None |
| 175 | if we cannot get the static block (this is the global block). */ |
| 176 | |
| 177 | static PyObject * |
| 178 | blpy_get_static_block (PyObject *self, void *closure) |
| 179 | { |
| 180 | const struct block *block; |
| 181 | const struct block *static_block; |
| 182 | block_object *self_obj = (block_object *) self; |
| 183 | |
| 184 | BLPY_REQUIRE_VALID (self, block); |
| 185 | |
| 186 | if (BLOCK_SUPERBLOCK (block) == NULL) |
| 187 | Py_RETURN_NONE; |
| 188 | |
| 189 | static_block = block_static_block (block); |
| 190 | |
| 191 | return block_to_block_object (static_block, self_obj->objfile); |
| 192 | } |
| 193 | |
| 194 | /* Implementation of gdb.Block.is_global (self) -> Boolean. |
| 195 | Returns True if this block object is a global block. */ |
| 196 | |
| 197 | static PyObject * |
| 198 | blpy_is_global (PyObject *self, void *closure) |
| 199 | { |
| 200 | const struct block *block; |
| 201 | |
| 202 | BLPY_REQUIRE_VALID (self, block); |
| 203 | |
| 204 | if (BLOCK_SUPERBLOCK (block)) |
| 205 | Py_RETURN_FALSE; |
| 206 | |
| 207 | Py_RETURN_TRUE; |
| 208 | } |
| 209 | |
| 210 | /* Implementation of gdb.Block.is_static (self) -> Boolean. |
| 211 | Returns True if this block object is a static block. */ |
| 212 | |
| 213 | static PyObject * |
| 214 | blpy_is_static (PyObject *self, void *closure) |
| 215 | { |
| 216 | const struct block *block; |
| 217 | |
| 218 | BLPY_REQUIRE_VALID (self, block); |
| 219 | |
| 220 | if (BLOCK_SUPERBLOCK (block) != NULL |
| 221 | && BLOCK_SUPERBLOCK (BLOCK_SUPERBLOCK (block)) == NULL) |
| 222 | Py_RETURN_TRUE; |
| 223 | |
| 224 | Py_RETURN_FALSE; |
| 225 | } |
| 226 | |
| 227 | /* Given a string, returns the gdb.Symbol representing that symbol in this |
| 228 | block. If such a symbol does not exist, returns NULL with a Python |
| 229 | exception. */ |
| 230 | |
| 231 | static PyObject * |
| 232 | blpy_getitem (PyObject *self, PyObject *key) |
| 233 | { |
| 234 | const struct block *block; |
| 235 | |
| 236 | BLPY_REQUIRE_VALID (self, block); |
| 237 | |
| 238 | gdb::unique_xmalloc_ptr<char> name = python_string_to_host_string (key); |
| 239 | if (name == nullptr) |
| 240 | return nullptr; |
| 241 | |
| 242 | lookup_name_info lookup_name (name.get(), symbol_name_match_type::FULL); |
| 243 | |
| 244 | /* We use ALL_BLOCK_SYMBOLS_WITH_NAME instead of block_lookup_symbol so |
| 245 | that we can look up symbols irrespective of the domain, matching the |
| 246 | iterator. It would be confusing if the iterator returns symbols you |
| 247 | can't find via getitem. */ |
| 248 | struct block_iterator iter; |
| 249 | struct symbol *sym = nullptr; |
| 250 | ALL_BLOCK_SYMBOLS_WITH_NAME (block, lookup_name, iter, sym) |
| 251 | { |
| 252 | /* Just stop at the first match */ |
| 253 | break; |
| 254 | } |
| 255 | |
| 256 | if (sym == nullptr) |
| 257 | { |
| 258 | PyErr_SetObject (PyExc_KeyError, key); |
| 259 | return nullptr; |
| 260 | } |
| 261 | return symbol_to_symbol_object (sym); |
| 262 | } |
| 263 | |
| 264 | static void |
| 265 | blpy_dealloc (PyObject *obj) |
| 266 | { |
| 267 | block_object *block = (block_object *) obj; |
| 268 | |
| 269 | if (block->prev) |
| 270 | block->prev->next = block->next; |
| 271 | else if (block->objfile) |
| 272 | { |
| 273 | set_objfile_data (block->objfile, blpy_objfile_data_key, |
| 274 | block->next); |
| 275 | } |
| 276 | if (block->next) |
| 277 | block->next->prev = block->prev; |
| 278 | block->block = NULL; |
| 279 | Py_TYPE (obj)->tp_free (obj); |
| 280 | } |
| 281 | |
| 282 | /* Given a block, and a block_object that has previously been |
| 283 | allocated and initialized, populate the block_object with the |
| 284 | struct block data. Also, register the block_object life-cycle |
| 285 | with the life-cycle of the object file associated with this |
| 286 | block, if needed. */ |
| 287 | static void |
| 288 | set_block (block_object *obj, const struct block *block, |
| 289 | struct objfile *objfile) |
| 290 | { |
| 291 | obj->block = block; |
| 292 | obj->prev = NULL; |
| 293 | if (objfile) |
| 294 | { |
| 295 | obj->objfile = objfile; |
| 296 | obj->next = ((struct blpy_block_object *) |
| 297 | objfile_data (objfile, blpy_objfile_data_key)); |
| 298 | if (obj->next) |
| 299 | obj->next->prev = obj; |
| 300 | set_objfile_data (objfile, blpy_objfile_data_key, obj); |
| 301 | } |
| 302 | else |
| 303 | obj->next = NULL; |
| 304 | } |
| 305 | |
| 306 | /* Create a new block object (gdb.Block) that encapsulates the struct |
| 307 | block object from GDB. */ |
| 308 | PyObject * |
| 309 | block_to_block_object (const struct block *block, struct objfile *objfile) |
| 310 | { |
| 311 | block_object *block_obj; |
| 312 | |
| 313 | block_obj = PyObject_New (block_object, &block_object_type); |
| 314 | if (block_obj) |
| 315 | set_block (block_obj, block, objfile); |
| 316 | |
| 317 | return (PyObject *) block_obj; |
| 318 | } |
| 319 | |
| 320 | /* Return struct block reference that is wrapped by this object. */ |
| 321 | const struct block * |
| 322 | block_object_to_block (PyObject *obj) |
| 323 | { |
| 324 | if (! PyObject_TypeCheck (obj, &block_object_type)) |
| 325 | return NULL; |
| 326 | return ((block_object *) obj)->block; |
| 327 | } |
| 328 | |
| 329 | /* Return a reference to the block iterator. */ |
| 330 | static PyObject * |
| 331 | blpy_block_syms_iter (PyObject *self) |
| 332 | { |
| 333 | block_syms_iterator_object *iter_obj = (block_syms_iterator_object *) self; |
| 334 | |
| 335 | BLPY_ITER_REQUIRE_VALID (iter_obj->source); |
| 336 | |
| 337 | Py_INCREF (self); |
| 338 | return self; |
| 339 | } |
| 340 | |
| 341 | /* Return the next symbol in the iteration through the block's |
| 342 | dictionary. */ |
| 343 | static PyObject * |
| 344 | blpy_block_syms_iternext (PyObject *self) |
| 345 | { |
| 346 | block_syms_iterator_object *iter_obj = (block_syms_iterator_object *) self; |
| 347 | struct symbol *sym; |
| 348 | |
| 349 | BLPY_ITER_REQUIRE_VALID (iter_obj->source); |
| 350 | |
| 351 | if (!iter_obj->initialized_p) |
| 352 | { |
| 353 | sym = block_iterator_first (iter_obj->block, &(iter_obj->iter)); |
| 354 | iter_obj->initialized_p = 1; |
| 355 | } |
| 356 | else |
| 357 | sym = block_iterator_next (&(iter_obj->iter)); |
| 358 | |
| 359 | if (sym == NULL) |
| 360 | { |
| 361 | PyErr_SetString (PyExc_StopIteration, _("Symbol is null.")); |
| 362 | return NULL; |
| 363 | } |
| 364 | |
| 365 | return symbol_to_symbol_object (sym); |
| 366 | } |
| 367 | |
| 368 | static void |
| 369 | blpy_block_syms_dealloc (PyObject *obj) |
| 370 | { |
| 371 | block_syms_iterator_object *iter_obj = (block_syms_iterator_object *) obj; |
| 372 | |
| 373 | Py_XDECREF (iter_obj->source); |
| 374 | Py_TYPE (obj)->tp_free (obj); |
| 375 | } |
| 376 | |
| 377 | /* Implementation of gdb.Block.is_valid (self) -> Boolean. |
| 378 | Returns True if this block object still exists in GDB. */ |
| 379 | |
| 380 | static PyObject * |
| 381 | blpy_is_valid (PyObject *self, PyObject *args) |
| 382 | { |
| 383 | const struct block *block; |
| 384 | |
| 385 | block = block_object_to_block (self); |
| 386 | if (block == NULL) |
| 387 | Py_RETURN_FALSE; |
| 388 | |
| 389 | Py_RETURN_TRUE; |
| 390 | } |
| 391 | |
| 392 | /* Implementation of gdb.BlockIterator.is_valid (self) -> Boolean. |
| 393 | Returns True if this block iterator object still exists in GDB */ |
| 394 | |
| 395 | static PyObject * |
| 396 | blpy_iter_is_valid (PyObject *self, PyObject *args) |
| 397 | { |
| 398 | block_syms_iterator_object *iter_obj = |
| 399 | (block_syms_iterator_object *) self; |
| 400 | |
| 401 | if (iter_obj->source->block == NULL) |
| 402 | Py_RETURN_FALSE; |
| 403 | |
| 404 | Py_RETURN_TRUE; |
| 405 | } |
| 406 | |
| 407 | /* This function is called when an objfile is about to be freed. |
| 408 | Invalidate the block as further actions on the block would result |
| 409 | in bad data. All access to obj->symbol should be gated by |
| 410 | BLPY_REQUIRE_VALID which will raise an exception on invalid |
| 411 | blocks. */ |
| 412 | static void |
| 413 | del_objfile_blocks (struct objfile *objfile, void *datum) |
| 414 | { |
| 415 | block_object *obj = (block_object *) datum; |
| 416 | |
| 417 | while (obj) |
| 418 | { |
| 419 | block_object *next = obj->next; |
| 420 | |
| 421 | obj->block = NULL; |
| 422 | obj->objfile = NULL; |
| 423 | obj->next = NULL; |
| 424 | obj->prev = NULL; |
| 425 | |
| 426 | obj = next; |
| 427 | } |
| 428 | } |
| 429 | |
| 430 | int |
| 431 | gdbpy_initialize_blocks (void) |
| 432 | { |
| 433 | block_object_type.tp_new = PyType_GenericNew; |
| 434 | if (PyType_Ready (&block_object_type) < 0) |
| 435 | return -1; |
| 436 | |
| 437 | block_syms_iterator_object_type.tp_new = PyType_GenericNew; |
| 438 | if (PyType_Ready (&block_syms_iterator_object_type) < 0) |
| 439 | return -1; |
| 440 | |
| 441 | /* Register an objfile "free" callback so we can properly |
| 442 | invalidate blocks when an object file is about to be |
| 443 | deleted. */ |
| 444 | blpy_objfile_data_key |
| 445 | = register_objfile_data_with_cleanup (NULL, del_objfile_blocks); |
| 446 | |
| 447 | if (gdb_pymodule_addobject (gdb_module, "Block", |
| 448 | (PyObject *) &block_object_type) < 0) |
| 449 | return -1; |
| 450 | |
| 451 | return gdb_pymodule_addobject (gdb_module, "BlockIterator", |
| 452 | (PyObject *) &block_syms_iterator_object_type); |
| 453 | } |
| 454 | |
| 455 | \f |
| 456 | |
| 457 | static PyMethodDef block_object_methods[] = { |
| 458 | { "is_valid", blpy_is_valid, METH_NOARGS, |
| 459 | "is_valid () -> Boolean.\n\ |
| 460 | Return true if this block is valid, false if not." }, |
| 461 | {NULL} /* Sentinel */ |
| 462 | }; |
| 463 | |
| 464 | static gdb_PyGetSetDef block_object_getset[] = { |
| 465 | { "start", blpy_get_start, NULL, "Start address of the block.", NULL }, |
| 466 | { "end", blpy_get_end, NULL, "End address of the block.", NULL }, |
| 467 | { "function", blpy_get_function, NULL, |
| 468 | "Symbol that names the block, or None.", NULL }, |
| 469 | { "superblock", blpy_get_superblock, NULL, |
| 470 | "Block containing the block, or None.", NULL }, |
| 471 | { "global_block", blpy_get_global_block, NULL, |
| 472 | "Block containing the global block.", NULL }, |
| 473 | { "static_block", blpy_get_static_block, NULL, |
| 474 | "Block containing the static block.", NULL }, |
| 475 | { "is_static", blpy_is_static, NULL, |
| 476 | "Whether this block is a static block.", NULL }, |
| 477 | { "is_global", blpy_is_global, NULL, |
| 478 | "Whether this block is a global block.", NULL }, |
| 479 | { NULL } /* Sentinel */ |
| 480 | }; |
| 481 | |
| 482 | static PyMappingMethods block_object_as_mapping = { |
| 483 | NULL, |
| 484 | blpy_getitem, |
| 485 | NULL |
| 486 | }; |
| 487 | |
| 488 | PyTypeObject block_object_type = { |
| 489 | PyVarObject_HEAD_INIT (NULL, 0) |
| 490 | "gdb.Block", /*tp_name*/ |
| 491 | sizeof (block_object), /*tp_basicsize*/ |
| 492 | 0, /*tp_itemsize*/ |
| 493 | blpy_dealloc, /*tp_dealloc*/ |
| 494 | 0, /*tp_print*/ |
| 495 | 0, /*tp_getattr*/ |
| 496 | 0, /*tp_setattr*/ |
| 497 | 0, /*tp_compare*/ |
| 498 | 0, /*tp_repr*/ |
| 499 | 0, /*tp_as_number*/ |
| 500 | 0, /*tp_as_sequence*/ |
| 501 | &block_object_as_mapping, /*tp_as_mapping*/ |
| 502 | 0, /*tp_hash */ |
| 503 | 0, /*tp_call*/ |
| 504 | 0, /*tp_str*/ |
| 505 | 0, /*tp_getattro*/ |
| 506 | 0, /*tp_setattro*/ |
| 507 | 0, /*tp_as_buffer*/ |
| 508 | Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_ITER, /*tp_flags*/ |
| 509 | "GDB block object", /* tp_doc */ |
| 510 | 0, /* tp_traverse */ |
| 511 | 0, /* tp_clear */ |
| 512 | 0, /* tp_richcompare */ |
| 513 | 0, /* tp_weaklistoffset */ |
| 514 | blpy_iter, /* tp_iter */ |
| 515 | 0, /* tp_iternext */ |
| 516 | block_object_methods, /* tp_methods */ |
| 517 | 0, /* tp_members */ |
| 518 | block_object_getset /* tp_getset */ |
| 519 | }; |
| 520 | |
| 521 | static PyMethodDef block_iterator_object_methods[] = { |
| 522 | { "is_valid", blpy_iter_is_valid, METH_NOARGS, |
| 523 | "is_valid () -> Boolean.\n\ |
| 524 | Return true if this block iterator is valid, false if not." }, |
| 525 | {NULL} /* Sentinel */ |
| 526 | }; |
| 527 | |
| 528 | PyTypeObject block_syms_iterator_object_type = { |
| 529 | PyVarObject_HEAD_INIT (NULL, 0) |
| 530 | "gdb.BlockIterator", /*tp_name*/ |
| 531 | sizeof (block_syms_iterator_object), /*tp_basicsize*/ |
| 532 | 0, /*tp_itemsize*/ |
| 533 | blpy_block_syms_dealloc, /*tp_dealloc*/ |
| 534 | 0, /*tp_print*/ |
| 535 | 0, /*tp_getattr*/ |
| 536 | 0, /*tp_setattr*/ |
| 537 | 0, /*tp_compare*/ |
| 538 | 0, /*tp_repr*/ |
| 539 | 0, /*tp_as_number*/ |
| 540 | 0, /*tp_as_sequence*/ |
| 541 | 0, /*tp_as_mapping*/ |
| 542 | 0, /*tp_hash */ |
| 543 | 0, /*tp_call*/ |
| 544 | 0, /*tp_str*/ |
| 545 | 0, /*tp_getattro*/ |
| 546 | 0, /*tp_setattro*/ |
| 547 | 0, /*tp_as_buffer*/ |
| 548 | Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_ITER, /*tp_flags*/ |
| 549 | "GDB block syms iterator object", /*tp_doc */ |
| 550 | 0, /*tp_traverse */ |
| 551 | 0, /*tp_clear */ |
| 552 | 0, /*tp_richcompare */ |
| 553 | 0, /*tp_weaklistoffset */ |
| 554 | blpy_block_syms_iter, /*tp_iter */ |
| 555 | blpy_block_syms_iternext, /*tp_iternext */ |
| 556 | block_iterator_object_methods /*tp_methods */ |
| 557 | }; |