1 /* Code dealing with blocks for GDB. 2 3 Copyright (C) 2003-2021 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 25 /* Opaque declarations. */ 26 27 struct symbol; 28 struct compunit_symtab; 29 struct block_namespace_info; 30 struct using_direct; 31 struct obstack; 32 struct addrmap; 33 34 /* Blocks can occupy non-contiguous address ranges. When this occurs, 35 startaddr and endaddr within struct block (still) specify the lowest 36 and highest addresses of all ranges, but each individual range is 37 specified by the addresses in struct blockrange. */ 38 39 struct blockrange 40 { blockrangeblockrange41 blockrange (CORE_ADDR startaddr_, CORE_ADDR endaddr_) 42 : startaddr (startaddr_), 43 endaddr (endaddr_) 44 { 45 } 46 47 /* Lowest address in this range. */ 48 49 CORE_ADDR startaddr; 50 51 /* One past the highest address in the range. */ 52 53 CORE_ADDR endaddr; 54 }; 55 56 /* Two or more non-contiguous ranges in the same order as that provided 57 via the debug info. */ 58 59 struct blockranges 60 { 61 int nranges; 62 struct blockrange range[1]; 63 }; 64 65 /* All of the name-scope contours of the program 66 are represented by `struct block' objects. 67 All of these objects are pointed to by the blockvector. 68 69 Each block represents one name scope. 70 Each lexical context has its own block. 71 72 The blockvector begins with some special blocks. 73 The GLOBAL_BLOCK contains all the symbols defined in this compilation 74 whose scope is the entire program linked together. 75 The STATIC_BLOCK contains all the symbols whose scope is the 76 entire compilation excluding other separate compilations. 77 Blocks starting with the FIRST_LOCAL_BLOCK are not special. 78 79 Each block records a range of core addresses for the code that 80 is in the scope of the block. The STATIC_BLOCK and GLOBAL_BLOCK 81 give, for the range of code, the entire range of code produced 82 by the compilation that the symbol segment belongs to. 83 84 The blocks appear in the blockvector 85 in order of increasing starting-address, 86 and, within that, in order of decreasing ending-address. 87 88 This implies that within the body of one function 89 the blocks appear in the order of a depth-first tree walk. */ 90 91 struct block 92 { 93 94 /* Addresses in the executable code that are in this block. */ 95 96 CORE_ADDR startaddr; 97 CORE_ADDR endaddr; 98 99 /* The symbol that names this block, if the block is the body of a 100 function (real or inlined); otherwise, zero. */ 101 102 struct symbol *function; 103 104 /* The `struct block' for the containing block, or 0 if none. 105 106 The superblock of a top-level local block (i.e. a function in the 107 case of C) is the STATIC_BLOCK. The superblock of the 108 STATIC_BLOCK is the GLOBAL_BLOCK. */ 109 110 const struct block *superblock; 111 112 /* This is used to store the symbols in the block. */ 113 114 struct multidictionary *multidict; 115 116 /* Contains information about namespace-related info relevant to this block: 117 using directives and the current namespace scope. */ 118 119 struct block_namespace_info *namespace_info; 120 121 /* Address ranges for blocks with non-contiguous ranges. If this 122 is NULL, then there is only one range which is specified by 123 startaddr and endaddr above. */ 124 125 struct blockranges *ranges; 126 }; 127 128 /* The global block is singled out so that we can provide a back-link 129 to the compunit symtab. */ 130 131 struct global_block 132 { 133 /* The block. */ 134 135 struct block block; 136 137 /* This holds a pointer to the compunit symtab holding this block. */ 138 139 struct compunit_symtab *compunit_symtab; 140 }; 141 142 #define BLOCK_START(bl) (bl)->startaddr 143 #define BLOCK_END(bl) (bl)->endaddr 144 #define BLOCK_FUNCTION(bl) (bl)->function 145 #define BLOCK_SUPERBLOCK(bl) (bl)->superblock 146 #define BLOCK_MULTIDICT(bl) (bl)->multidict 147 #define BLOCK_NAMESPACE(bl) (bl)->namespace_info 148 149 /* Accessor for ranges field within block BL. */ 150 151 #define BLOCK_RANGES(bl) (bl)->ranges 152 153 /* Number of ranges within a block. */ 154 155 #define BLOCK_NRANGES(bl) (bl)->ranges->nranges 156 157 /* Access range array for block BL. */ 158 159 #define BLOCK_RANGE(bl) (bl)->ranges->range 160 161 /* Are all addresses within a block contiguous? */ 162 163 #define BLOCK_CONTIGUOUS_P(bl) (BLOCK_RANGES (bl) == nullptr \ 164 || BLOCK_NRANGES (bl) <= 1) 165 166 /* Obtain the start address of the Nth range for block BL. */ 167 168 #define BLOCK_RANGE_START(bl,n) (BLOCK_RANGE (bl)[n].startaddr) 169 170 /* Obtain the end address of the Nth range for block BL. */ 171 172 #define BLOCK_RANGE_END(bl,n) (BLOCK_RANGE (bl)[n].endaddr) 173 174 /* Define the "entry pc" for a block BL to be the lowest (start) address 175 for the block when all addresses within the block are contiguous. If 176 non-contiguous, then use the start address for the first range in the 177 block. 178 179 At the moment, this almost matches what DWARF specifies as the entry 180 pc. (The missing bit is support for DW_AT_entry_pc which should be 181 preferred over range data and the low_pc.) 182 183 Once support for DW_AT_entry_pc is added, I expect that an entry_pc 184 field will be added to one of these data structures. Once that's done, 185 the entry_pc field can be set from the dwarf reader (and other readers 186 too). BLOCK_ENTRY_PC can then be redefined to be less DWARF-centric. */ 187 188 #define BLOCK_ENTRY_PC(bl) (BLOCK_CONTIGUOUS_P (bl) \ 189 ? BLOCK_START (bl) \ 190 : BLOCK_RANGE_START (bl,0)) 191 192 struct blockvector 193 { 194 /* Number of blocks in the list. */ 195 int nblocks; 196 /* An address map mapping addresses to blocks in this blockvector. 197 This pointer is zero if the blocks' start and end addresses are 198 enough. */ 199 struct addrmap *map; 200 /* The blocks themselves. */ 201 struct block *block[1]; 202 }; 203 204 #define BLOCKVECTOR_NBLOCKS(blocklist) (blocklist)->nblocks 205 #define BLOCKVECTOR_BLOCK(blocklist,n) (blocklist)->block[n] 206 #define BLOCKVECTOR_MAP(blocklist) ((blocklist)->map) 207 208 /* Return the objfile of BLOCK, which must be non-NULL. */ 209 210 extern struct objfile *block_objfile (const struct block *block); 211 212 /* Return the architecture of BLOCK, which must be non-NULL. */ 213 214 extern struct gdbarch *block_gdbarch (const struct block *block); 215 216 extern struct symbol *block_linkage_function (const struct block *); 217 218 extern struct symbol *block_containing_function (const struct block *); 219 220 extern int block_inlined_p (const struct block *block); 221 222 /* Return true if block A is lexically nested within block B, or if a 223 and b have the same pc range. Return false otherwise. If 224 ALLOW_NESTED is true, then block A is considered to be in block B 225 if A is in a nested function in B's function. If ALLOW_NESTED is 226 false (the default), then blocks in nested functions are not 227 considered to be contained. */ 228 229 extern bool contained_in (const struct block *a, const struct block *b, 230 bool allow_nested = false); 231 232 extern const struct blockvector *blockvector_for_pc (CORE_ADDR, 233 const struct block **); 234 235 extern const struct blockvector * 236 blockvector_for_pc_sect (CORE_ADDR, struct obj_section *, 237 const struct block **, struct compunit_symtab *); 238 239 extern int blockvector_contains_pc (const struct blockvector *bv, CORE_ADDR pc); 240 241 extern struct call_site *call_site_for_pc (struct gdbarch *gdbarch, 242 CORE_ADDR pc); 243 244 extern const struct block *block_for_pc (CORE_ADDR); 245 246 extern const struct block *block_for_pc_sect (CORE_ADDR, struct obj_section *); 247 248 extern const char *block_scope (const struct block *block); 249 250 extern void block_set_scope (struct block *block, const char *scope, 251 struct obstack *obstack); 252 253 extern struct using_direct *block_using (const struct block *block); 254 255 extern void block_set_using (struct block *block, 256 struct using_direct *using_decl, 257 struct obstack *obstack); 258 259 extern const struct block *block_static_block (const struct block *block); 260 261 extern const struct block *block_global_block (const struct block *block); 262 263 extern struct block *allocate_block (struct obstack *obstack); 264 265 extern struct block *allocate_global_block (struct obstack *obstack); 266 267 extern void set_block_compunit_symtab (struct block *, 268 struct compunit_symtab *); 269 270 /* Return a property to evaluate the static link associated to BLOCK. 271 272 In the context of nested functions (available in Pascal, Ada and GNU C, for 273 instance), a static link (as in DWARF's DW_AT_static_link attribute) for a 274 function is a way to get the frame corresponding to the enclosing function. 275 276 Note that only objfile-owned and function-level blocks can have a static 277 link. Return NULL if there is no such property. */ 278 279 extern struct dynamic_prop *block_static_link (const struct block *block); 280 281 /* A block iterator. This structure should be treated as though it 282 were opaque; it is only defined here because we want to support 283 stack allocation of iterators. */ 284 285 struct block_iterator 286 { 287 /* If we're iterating over a single block, this holds the block. 288 Otherwise, it holds the canonical compunit. */ 289 290 union 291 { 292 struct compunit_symtab *compunit_symtab; 293 const struct block *block; 294 } d; 295 296 /* If we're iterating over a single block, this is always -1. 297 Otherwise, it holds the index of the current "included" symtab in 298 the canonical symtab (that is, d.symtab->includes[idx]), with -1 299 meaning the canonical symtab itself. */ 300 301 int idx; 302 303 /* Which block, either static or global, to iterate over. If this 304 is FIRST_LOCAL_BLOCK, then we are iterating over a single block. 305 This is used to select which field of 'd' is in use. */ 306 307 enum block_enum which; 308 309 /* The underlying multidictionary iterator. */ 310 311 struct mdict_iterator mdict_iter; 312 }; 313 314 /* Initialize ITERATOR to point at the first symbol in BLOCK, and 315 return that first symbol, or NULL if BLOCK is empty. */ 316 317 extern struct symbol *block_iterator_first (const struct block *block, 318 struct block_iterator *iterator); 319 320 /* Advance ITERATOR, and return the next symbol, or NULL if there are 321 no more symbols. Don't call this if you've previously received 322 NULL from block_iterator_first or block_iterator_next on this 323 iteration. */ 324 325 extern struct symbol *block_iterator_next (struct block_iterator *iterator); 326 327 /* Initialize ITERATOR to point at the first symbol in BLOCK whose 328 search_name () matches NAME, and return that first symbol, or 329 NULL if there are no such symbols. */ 330 331 extern struct symbol *block_iter_match_first (const struct block *block, 332 const lookup_name_info &name, 333 struct block_iterator *iterator); 334 335 /* Advance ITERATOR to point at the next symbol in BLOCK whose 336 search_name () matches NAME, or NULL if there are no more such 337 symbols. Don't call this if you've previously received NULL from 338 block_iterator_match_first or block_iterator_match_next on this 339 iteration. And don't call it unless ITERATOR was created by a 340 previous call to block_iter_match_first with the same NAME. */ 341 342 extern struct symbol *block_iter_match_next 343 (const lookup_name_info &name, struct block_iterator *iterator); 344 345 /* Return true if symbol A is the best match possible for DOMAIN. */ 346 347 extern bool best_symbol (struct symbol *a, const domain_enum domain); 348 349 /* Return symbol B if it is a better match than symbol A for DOMAIN. 350 Otherwise return A. */ 351 352 extern struct symbol *better_symbol (struct symbol *a, struct symbol *b, 353 const domain_enum domain); 354 355 /* Search BLOCK for symbol NAME in DOMAIN. */ 356 357 extern struct symbol *block_lookup_symbol (const struct block *block, 358 const char *name, 359 symbol_name_match_type match_type, 360 const domain_enum domain); 361 362 /* Search BLOCK for symbol NAME in DOMAIN but only in primary symbol table of 363 BLOCK. BLOCK must be STATIC_BLOCK or GLOBAL_BLOCK. Function is useful if 364 one iterates all global/static blocks of an objfile. */ 365 366 extern struct symbol *block_lookup_symbol_primary (const struct block *block, 367 const char *name, 368 const domain_enum domain); 369 370 /* The type of the MATCHER argument to block_find_symbol. */ 371 372 typedef int (block_symbol_matcher_ftype) (struct symbol *, void *); 373 374 /* Find symbol NAME in BLOCK and in DOMAIN that satisfies MATCHER. 375 DATA is passed unchanged to MATCHER. 376 BLOCK must be STATIC_BLOCK or GLOBAL_BLOCK. */ 377 378 extern struct symbol *block_find_symbol (const struct block *block, 379 const char *name, 380 const domain_enum domain, 381 block_symbol_matcher_ftype *matcher, 382 void *data); 383 384 /* A matcher function for block_find_symbol to find only symbols with 385 non-opaque types. */ 386 387 extern int block_find_non_opaque_type (struct symbol *sym, void *data); 388 389 /* A matcher function for block_find_symbol to prefer symbols with 390 non-opaque types. The way to use this function is as follows: 391 392 struct symbol *with_opaque = NULL; 393 struct symbol *sym 394 = block_find_symbol (block, name, domain, 395 block_find_non_opaque_type_preferred, &with_opaque); 396 397 At this point if SYM is non-NULL then a non-opaque type has been found. 398 Otherwise, if WITH_OPAQUE is non-NULL then an opaque type has been found. 399 Otherwise, the symbol was not found. */ 400 401 extern int block_find_non_opaque_type_preferred (struct symbol *sym, 402 void *data); 403 404 /* Macro to loop through all symbols in BLOCK, in no particular 405 order. ITER helps keep track of the iteration, and must be a 406 struct block_iterator. SYM points to the current symbol. */ 407 408 #define ALL_BLOCK_SYMBOLS(block, iter, sym) \ 409 for ((sym) = block_iterator_first ((block), &(iter)); \ 410 (sym); \ 411 (sym) = block_iterator_next (&(iter))) 412 413 /* Macro to loop through all symbols in BLOCK with a name that matches 414 NAME, in no particular order. ITER helps keep track of the 415 iteration, and must be a struct block_iterator. SYM points to the 416 current symbol. */ 417 418 #define ALL_BLOCK_SYMBOLS_WITH_NAME(block, name, iter, sym) \ 419 for ((sym) = block_iter_match_first ((block), (name), &(iter)); \ 420 (sym) != NULL; \ 421 (sym) = block_iter_match_next ((name), &(iter))) 422 423 /* Given a vector of pairs, allocate and build an obstack allocated 424 blockranges struct for a block. */ 425 struct blockranges *make_blockranges (struct objfile *objfile, 426 const std::vector<blockrange> &rangevec); 427 428 #endif /* BLOCK_H */ 429