1 /* Code dealing with blocks for GDB. 2 3 Copyright (C) 2003-2023 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 #ifndef BLOCK_H 21 #define BLOCK_H 22 23 #include "dictionary.h" 24 #include "gdbsupport/array-view.h" 25 26 /* Opaque declarations. */ 27 28 struct symbol; 29 struct compunit_symtab; 30 struct block_namespace_info; 31 struct using_direct; 32 struct obstack; 33 struct addrmap; 34 35 /* Blocks can occupy non-contiguous address ranges. When this occurs, 36 startaddr and endaddr within struct block (still) specify the lowest 37 and highest addresses of all ranges, but each individual range is 38 specified by the addresses in struct blockrange. */ 39 40 struct blockrange 41 { 42 blockrange (CORE_ADDR start, CORE_ADDR end) 43 : m_start (start), 44 m_end (end) 45 { 46 } 47 48 /* Return this blockrange's start address. */ 49 CORE_ADDR start () const 50 { return m_start; } 51 52 /* Set this blockrange's start address. */ 53 void set_start (CORE_ADDR start) 54 { m_start = start; } 55 56 /* Return this blockrange's end address. */ 57 CORE_ADDR end () const 58 { return m_end; } 59 60 /* Set this blockrange's end address. */ 61 void set_end (CORE_ADDR end) 62 { m_end = end; } 63 64 /* Lowest address in this range. */ 65 66 CORE_ADDR m_start; 67 68 /* One past the highest address in the range. */ 69 70 CORE_ADDR m_end; 71 }; 72 73 /* Two or more non-contiguous ranges in the same order as that provided 74 via the debug info. */ 75 76 struct blockranges 77 { 78 int nranges; 79 struct blockrange range[1]; 80 }; 81 82 /* All of the name-scope contours of the program 83 are represented by `struct block' objects. 84 All of these objects are pointed to by the blockvector. 85 86 Each block represents one name scope. 87 Each lexical context has its own block. 88 89 The blockvector begins with some special blocks. 90 The GLOBAL_BLOCK contains all the symbols defined in this compilation 91 whose scope is the entire program linked together. 92 The STATIC_BLOCK contains all the symbols whose scope is the 93 entire compilation excluding other separate compilations. 94 Blocks starting with the FIRST_LOCAL_BLOCK are not special. 95 96 Each block records a range of core addresses for the code that 97 is in the scope of the block. The STATIC_BLOCK and GLOBAL_BLOCK 98 give, for the range of code, the entire range of code produced 99 by the compilation that the symbol segment belongs to. 100 101 The blocks appear in the blockvector 102 in order of increasing starting-address, 103 and, within that, in order of decreasing ending-address. 104 105 This implies that within the body of one function 106 the blocks appear in the order of a depth-first tree walk. */ 107 108 struct block 109 { 110 /* Return this block's start address. */ 111 CORE_ADDR start () const 112 { return m_start; } 113 114 /* Set this block's start address. */ 115 void set_start (CORE_ADDR start) 116 { m_start = start; } 117 118 /* Return this block's end address. */ 119 CORE_ADDR end () const 120 { return m_end; } 121 122 /* Set this block's end address. */ 123 void set_end (CORE_ADDR end) 124 { m_end = end; } 125 126 /* Return this block's function symbol. */ 127 symbol *function () const 128 { return m_function; } 129 130 /* Set this block's function symbol. */ 131 void set_function (symbol *function) 132 { m_function = function; } 133 134 /* Return this block's superblock. */ 135 const block *superblock () const 136 { return m_superblock; } 137 138 /* Set this block's superblock. */ 139 void set_superblock (const block *superblock) 140 { m_superblock = superblock; } 141 142 /* Return this block's multidict. */ 143 multidictionary *multidict () const 144 { return m_multidict; } 145 146 /* Set this block's multidict. */ 147 void set_multidict (multidictionary *multidict) 148 { m_multidict = multidict; } 149 150 /* Return this block's namespace info. */ 151 block_namespace_info *namespace_info () const 152 { return m_namespace_info; } 153 154 /* Set this block's namespace info. */ 155 void set_namespace_info (block_namespace_info *namespace_info) 156 { m_namespace_info = namespace_info; } 157 158 /* Return a view on this block's ranges. */ 159 gdb::array_view<blockrange> ranges () 160 { 161 if (m_ranges == nullptr) 162 return {}; 163 else 164 return gdb::make_array_view (m_ranges->range, m_ranges->nranges); 165 } 166 167 /* Const version of the above. */ 168 gdb::array_view<const blockrange> ranges () const 169 { 170 if (m_ranges == nullptr) 171 return {}; 172 else 173 return gdb::make_array_view (m_ranges->range, m_ranges->nranges); 174 } 175 176 /* Set this block's ranges array. */ 177 void set_ranges (blockranges *ranges) 178 { m_ranges = ranges; } 179 180 /* Return true if all addresses within this block are contiguous. */ 181 bool is_contiguous () const 182 { return this->ranges ().size () <= 1; } 183 184 /* Return the "entry PC" of this block. 185 186 The entry PC is the lowest (start) address for the block when all addresses 187 within the block are contiguous. If non-contiguous, then use the start 188 address for the first range in the block. 189 190 At the moment, this almost matches what DWARF specifies as the entry 191 pc. (The missing bit is support for DW_AT_entry_pc which should be 192 preferred over range data and the low_pc.) 193 194 Once support for DW_AT_entry_pc is added, I expect that an entry_pc 195 field will be added to one of these data structures. Once that's done, 196 the entry_pc field can be set from the dwarf reader (and other readers 197 too). ENTRY_PC can then be redefined to be less DWARF-centric. */ 198 199 CORE_ADDR entry_pc () const 200 { 201 if (this->is_contiguous ()) 202 return this->start (); 203 else 204 return this->ranges ()[0].start (); 205 } 206 207 /* Addresses in the executable code that are in this block. */ 208 209 CORE_ADDR m_start; 210 CORE_ADDR m_end; 211 212 /* The symbol that names this block, if the block is the body of a 213 function (real or inlined); otherwise, zero. */ 214 215 struct symbol *m_function; 216 217 /* The `struct block' for the containing block, or 0 if none. 218 219 The superblock of a top-level local block (i.e. a function in the 220 case of C) is the STATIC_BLOCK. The superblock of the 221 STATIC_BLOCK is the GLOBAL_BLOCK. */ 222 223 const struct block *m_superblock; 224 225 /* This is used to store the symbols in the block. */ 226 227 struct multidictionary *m_multidict; 228 229 /* Contains information about namespace-related info relevant to this block: 230 using directives and the current namespace scope. */ 231 232 struct block_namespace_info *m_namespace_info; 233 234 /* Address ranges for blocks with non-contiguous ranges. If this 235 is NULL, then there is only one range which is specified by 236 startaddr and endaddr above. */ 237 238 struct blockranges *m_ranges; 239 }; 240 241 /* The global block is singled out so that we can provide a back-link 242 to the compunit symtab. */ 243 244 struct global_block 245 { 246 /* The block. */ 247 248 struct block block; 249 250 /* This holds a pointer to the compunit symtab holding this block. */ 251 252 struct compunit_symtab *compunit_symtab; 253 }; 254 255 struct blockvector 256 { 257 /* Return a view on the blocks of this blockvector. */ 258 gdb::array_view<struct block *> blocks () 259 { 260 return gdb::array_view<struct block *> (m_blocks, m_num_blocks); 261 } 262 263 /* Const version of the above. */ 264 gdb::array_view<const struct block *const> blocks () const 265 { 266 const struct block **blocks = (const struct block **) m_blocks; 267 return gdb::array_view<const struct block *const> (blocks, m_num_blocks); 268 } 269 270 /* Return the block at index I. */ 271 struct block *block (size_t i) 272 { return this->blocks ()[i]; } 273 274 /* Const version of the above. */ 275 const struct block *block (size_t i) const 276 { return this->blocks ()[i]; } 277 278 /* Set the block at index I. */ 279 void set_block (int i, struct block *block) 280 { m_blocks[i] = block; } 281 282 /* Set the number of blocks of this blockvector. 283 284 The storage of blocks is done using a flexible array member, so the number 285 of blocks set here must agree with what was effectively allocated. */ 286 void set_num_blocks (int num_blocks) 287 { m_num_blocks = num_blocks; } 288 289 /* Return the number of blocks in this blockvector. */ 290 int num_blocks () const 291 { return m_num_blocks; } 292 293 /* Return the global block of this blockvector. */ 294 struct block *global_block () 295 { return this->block (GLOBAL_BLOCK); } 296 297 /* Const version of the above. */ 298 const struct block *global_block () const 299 { return this->block (GLOBAL_BLOCK); } 300 301 /* Return the static block of this blockvector. */ 302 struct block *static_block () 303 { return this->block (STATIC_BLOCK); } 304 305 /* Const version of the above. */ 306 const struct block *static_block () const 307 { return this->block (STATIC_BLOCK); } 308 309 /* Return the address -> block map of this blockvector. */ 310 addrmap *map () 311 { return m_map; } 312 313 /* Const version of the above. */ 314 const addrmap *map () const 315 { return m_map; } 316 317 /* Set this blockvector's address -> block map. */ 318 void set_map (addrmap *map) 319 { m_map = map; } 320 321 private: 322 /* An address map mapping addresses to blocks in this blockvector. 323 This pointer is zero if the blocks' start and end addresses are 324 enough. */ 325 struct addrmap *m_map; 326 327 /* Number of blocks in the list. */ 328 int m_num_blocks; 329 330 /* The blocks themselves. */ 331 struct block *m_blocks[1]; 332 }; 333 334 /* Return the objfile of BLOCK, which must be non-NULL. */ 335 336 extern struct objfile *block_objfile (const struct block *block); 337 338 /* Return the architecture of BLOCK, which must be non-NULL. */ 339 340 extern struct gdbarch *block_gdbarch (const struct block *block); 341 342 extern struct symbol *block_linkage_function (const struct block *); 343 344 extern struct symbol *block_containing_function (const struct block *); 345 346 extern int block_inlined_p (const struct block *block); 347 348 /* Return true if block A is lexically nested within block B, or if a 349 and b have the same pc range. Return false otherwise. If 350 ALLOW_NESTED is true, then block A is considered to be in block B 351 if A is in a nested function in B's function. If ALLOW_NESTED is 352 false (the default), then blocks in nested functions are not 353 considered to be contained. */ 354 355 extern bool contained_in (const struct block *a, const struct block *b, 356 bool allow_nested = false); 357 358 extern const struct blockvector *blockvector_for_pc (CORE_ADDR, 359 const struct block **); 360 361 extern const struct blockvector * 362 blockvector_for_pc_sect (CORE_ADDR, struct obj_section *, 363 const struct block **, struct compunit_symtab *); 364 365 extern int blockvector_contains_pc (const struct blockvector *bv, CORE_ADDR pc); 366 367 extern struct call_site *call_site_for_pc (struct gdbarch *gdbarch, 368 CORE_ADDR pc); 369 370 extern const struct block *block_for_pc (CORE_ADDR); 371 372 extern const struct block *block_for_pc_sect (CORE_ADDR, struct obj_section *); 373 374 extern const char *block_scope (const struct block *block); 375 376 extern void block_set_scope (struct block *block, const char *scope, 377 struct obstack *obstack); 378 379 extern struct using_direct *block_using (const struct block *block); 380 381 extern void block_set_using (struct block *block, 382 struct using_direct *using_decl, 383 struct obstack *obstack); 384 385 extern const struct block *block_static_block (const struct block *block); 386 387 extern const struct block *block_global_block (const struct block *block); 388 389 extern struct block *allocate_block (struct obstack *obstack); 390 391 extern struct block *allocate_global_block (struct obstack *obstack); 392 393 extern void set_block_compunit_symtab (struct block *, 394 struct compunit_symtab *); 395 396 /* Return a property to evaluate the static link associated to BLOCK. 397 398 In the context of nested functions (available in Pascal, Ada and GNU C, for 399 instance), a static link (as in DWARF's DW_AT_static_link attribute) for a 400 function is a way to get the frame corresponding to the enclosing function. 401 402 Note that only objfile-owned and function-level blocks can have a static 403 link. Return NULL if there is no such property. */ 404 405 extern struct dynamic_prop *block_static_link (const struct block *block); 406 407 /* A block iterator. This structure should be treated as though it 408 were opaque; it is only defined here because we want to support 409 stack allocation of iterators. */ 410 411 struct block_iterator 412 { 413 /* If we're iterating over a single block, this holds the block. 414 Otherwise, it holds the canonical compunit. */ 415 416 union 417 { 418 struct compunit_symtab *compunit_symtab; 419 const struct block *block; 420 } d; 421 422 /* If we're iterating over a single block, this is always -1. 423 Otherwise, it holds the index of the current "included" symtab in 424 the canonical symtab (that is, d.symtab->includes[idx]), with -1 425 meaning the canonical symtab itself. */ 426 427 int idx; 428 429 /* Which block, either static or global, to iterate over. If this 430 is FIRST_LOCAL_BLOCK, then we are iterating over a single block. 431 This is used to select which field of 'd' is in use. */ 432 433 enum block_enum which; 434 435 /* The underlying multidictionary iterator. */ 436 437 struct mdict_iterator mdict_iter; 438 }; 439 440 /* Initialize ITERATOR to point at the first symbol in BLOCK, and 441 return that first symbol, or NULL if BLOCK is empty. */ 442 443 extern struct symbol *block_iterator_first (const struct block *block, 444 struct block_iterator *iterator); 445 446 /* Advance ITERATOR, and return the next symbol, or NULL if there are 447 no more symbols. Don't call this if you've previously received 448 NULL from block_iterator_first or block_iterator_next on this 449 iteration. */ 450 451 extern struct symbol *block_iterator_next (struct block_iterator *iterator); 452 453 /* Initialize ITERATOR to point at the first symbol in BLOCK whose 454 search_name () matches NAME, and return that first symbol, or 455 NULL if there are no such symbols. */ 456 457 extern struct symbol *block_iter_match_first (const struct block *block, 458 const lookup_name_info &name, 459 struct block_iterator *iterator); 460 461 /* Advance ITERATOR to point at the next symbol in BLOCK whose 462 search_name () matches NAME, or NULL if there are no more such 463 symbols. Don't call this if you've previously received NULL from 464 block_iterator_match_first or block_iterator_match_next on this 465 iteration. And don't call it unless ITERATOR was created by a 466 previous call to block_iter_match_first with the same NAME. */ 467 468 extern struct symbol *block_iter_match_next 469 (const lookup_name_info &name, struct block_iterator *iterator); 470 471 /* Return true if symbol A is the best match possible for DOMAIN. */ 472 473 extern bool best_symbol (struct symbol *a, const domain_enum domain); 474 475 /* Return symbol B if it is a better match than symbol A for DOMAIN. 476 Otherwise return A. */ 477 478 extern struct symbol *better_symbol (struct symbol *a, struct symbol *b, 479 const domain_enum domain); 480 481 /* Search BLOCK for symbol NAME in DOMAIN. */ 482 483 extern struct symbol *block_lookup_symbol (const struct block *block, 484 const char *name, 485 symbol_name_match_type match_type, 486 const domain_enum domain); 487 488 /* Search BLOCK for symbol NAME in DOMAIN but only in primary symbol table of 489 BLOCK. BLOCK must be STATIC_BLOCK or GLOBAL_BLOCK. Function is useful if 490 one iterates all global/static blocks of an objfile. */ 491 492 extern struct symbol *block_lookup_symbol_primary (const struct block *block, 493 const char *name, 494 const domain_enum domain); 495 496 /* The type of the MATCHER argument to block_find_symbol. */ 497 498 typedef int (block_symbol_matcher_ftype) (struct symbol *, void *); 499 500 /* Find symbol NAME in BLOCK and in DOMAIN that satisfies MATCHER. 501 DATA is passed unchanged to MATCHER. 502 BLOCK must be STATIC_BLOCK or GLOBAL_BLOCK. */ 503 504 extern struct symbol *block_find_symbol (const struct block *block, 505 const char *name, 506 const domain_enum domain, 507 block_symbol_matcher_ftype *matcher, 508 void *data); 509 510 /* A matcher function for block_find_symbol to find only symbols with 511 non-opaque types. */ 512 513 extern int block_find_non_opaque_type (struct symbol *sym, void *data); 514 515 /* A matcher function for block_find_symbol to prefer symbols with 516 non-opaque types. The way to use this function is as follows: 517 518 struct symbol *with_opaque = NULL; 519 struct symbol *sym 520 = block_find_symbol (block, name, domain, 521 block_find_non_opaque_type_preferred, &with_opaque); 522 523 At this point if SYM is non-NULL then a non-opaque type has been found. 524 Otherwise, if WITH_OPAQUE is non-NULL then an opaque type has been found. 525 Otherwise, the symbol was not found. */ 526 527 extern int block_find_non_opaque_type_preferred (struct symbol *sym, 528 void *data); 529 530 /* Macro to loop through all symbols in BLOCK, in no particular 531 order. ITER helps keep track of the iteration, and must be a 532 struct block_iterator. SYM points to the current symbol. */ 533 534 #define ALL_BLOCK_SYMBOLS(block, iter, sym) \ 535 for ((sym) = block_iterator_first ((block), &(iter)); \ 536 (sym); \ 537 (sym) = block_iterator_next (&(iter))) 538 539 /* Macro to loop through all symbols in BLOCK with a name that matches 540 NAME, in no particular order. ITER helps keep track of the 541 iteration, and must be a struct block_iterator. SYM points to the 542 current symbol. */ 543 544 #define ALL_BLOCK_SYMBOLS_WITH_NAME(block, name, iter, sym) \ 545 for ((sym) = block_iter_match_first ((block), (name), &(iter)); \ 546 (sym) != NULL; \ 547 (sym) = block_iter_match_next ((name), &(iter))) 548 549 /* Given a vector of pairs, allocate and build an obstack allocated 550 blockranges struct for a block. */ 551 struct blockranges *make_blockranges (struct objfile *objfile, 552 const std::vector<blockrange> &rangevec); 553 554 #endif /* BLOCK_H */ 555