| 1 | /* Code dealing with blocks for GDB. |
| 2 | |
| 3 | Copyright (C) 2003-2020 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 | { |
| 41 | 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 */ |