| 1 | /* DWARF 2 debugging format support for GDB. |
| 2 | |
| 3 | Copyright (C) 1994-2020 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 DWARF2READ_H |
| 21 | #define DWARF2READ_H |
| 22 | |
| 23 | #include <queue> |
| 24 | #include <unordered_map> |
| 25 | #include "dwarf2/comp-unit.h" |
| 26 | #include "dwarf2/index-cache.h" |
| 27 | #include "dwarf2/section.h" |
| 28 | #include "filename-seen-cache.h" |
| 29 | #include "gdb_obstack.h" |
| 30 | #include "gdbsupport/hash_enum.h" |
| 31 | #include "psympriv.h" |
| 32 | |
| 33 | /* Hold 'maintenance (set|show) dwarf' commands. */ |
| 34 | extern struct cmd_list_element *set_dwarf_cmdlist; |
| 35 | extern struct cmd_list_element *show_dwarf_cmdlist; |
| 36 | |
| 37 | struct tu_stats |
| 38 | { |
| 39 | int nr_uniq_abbrev_tables; |
| 40 | int nr_symtabs; |
| 41 | int nr_symtab_sharers; |
| 42 | int nr_stmt_less_type_units; |
| 43 | int nr_all_type_units_reallocs; |
| 44 | }; |
| 45 | |
| 46 | struct dwarf2_cu; |
| 47 | struct dwarf2_debug_sections; |
| 48 | struct dwarf2_per_cu_data; |
| 49 | struct mapped_index; |
| 50 | struct mapped_debug_names; |
| 51 | struct signatured_type; |
| 52 | struct type_unit_group; |
| 53 | |
| 54 | /* One item on the queue of compilation units to read in full symbols |
| 55 | for. */ |
| 56 | struct dwarf2_queue_item |
| 57 | { |
| 58 | dwarf2_queue_item (dwarf2_per_cu_data *cu, dwarf2_per_objfile *per_objfile, |
| 59 | enum language lang) |
| 60 | : per_cu (cu), |
| 61 | per_objfile (per_objfile), |
| 62 | pretend_language (lang) |
| 63 | { |
| 64 | } |
| 65 | |
| 66 | ~dwarf2_queue_item (); |
| 67 | |
| 68 | DISABLE_COPY_AND_ASSIGN (dwarf2_queue_item); |
| 69 | |
| 70 | dwarf2_per_cu_data *per_cu; |
| 71 | dwarf2_per_objfile *per_objfile; |
| 72 | enum language pretend_language; |
| 73 | }; |
| 74 | |
| 75 | /* Some DWARF data can be shared across objfiles who share the same BFD, |
| 76 | this data is stored in this object. |
| 77 | |
| 78 | Two dwarf2_per_objfile objects representing objfiles sharing the same BFD |
| 79 | will point to the same instance of dwarf2_per_bfd, unless the BFD requires |
| 80 | relocation. */ |
| 81 | |
| 82 | struct dwarf2_per_bfd |
| 83 | { |
| 84 | /* Construct a dwarf2_per_bfd for OBFD. NAMES points to the |
| 85 | dwarf2 section names, or is NULL if the standard ELF names are |
| 86 | used. CAN_COPY is true for formats where symbol |
| 87 | interposition is possible and so symbol values must follow copy |
| 88 | relocation rules. */ |
| 89 | dwarf2_per_bfd (bfd *obfd, const dwarf2_debug_sections *names, bool can_copy); |
| 90 | |
| 91 | ~dwarf2_per_bfd (); |
| 92 | |
| 93 | DISABLE_COPY_AND_ASSIGN (dwarf2_per_bfd); |
| 94 | |
| 95 | /* Return the CU/TU given its index. |
| 96 | |
| 97 | This is intended for loops like: |
| 98 | |
| 99 | for (i = 0; i < (dwarf2_per_bfd->n_comp_units |
| 100 | + dwarf2_per_bfd->n_type_units); ++i) |
| 101 | { |
| 102 | dwarf2_per_cu_data *per_cu = dwarf2_per_bfd->get_cutu (i); |
| 103 | |
| 104 | ...; |
| 105 | } |
| 106 | */ |
| 107 | dwarf2_per_cu_data *get_cutu (int index); |
| 108 | |
| 109 | /* Return the CU given its index. |
| 110 | This differs from get_cutu in that it's for when you know INDEX refers to a |
| 111 | CU. */ |
| 112 | dwarf2_per_cu_data *get_cu (int index); |
| 113 | |
| 114 | /* Return the TU given its index. |
| 115 | This differs from get_cutu in that it's for when you know INDEX refers to a |
| 116 | TU. */ |
| 117 | signatured_type *get_tu (int index); |
| 118 | |
| 119 | /* A convenience function to allocate a dwarf2_per_cu_data. The |
| 120 | returned object has its "index" field set properly. The object |
| 121 | is allocated on the dwarf2_per_bfd obstack. */ |
| 122 | dwarf2_per_cu_data *allocate_per_cu (); |
| 123 | |
| 124 | /* A convenience function to allocate a signatured_type. The |
| 125 | returned object has its "index" field set properly. The object |
| 126 | is allocated on the dwarf2_per_bfd obstack. */ |
| 127 | signatured_type *allocate_signatured_type (); |
| 128 | |
| 129 | /* Return the number of partial symtabs allocated with allocate_per_cu |
| 130 | and allocate_signatured_type so far. */ |
| 131 | int num_psymtabs () const |
| 132 | { return m_num_psymtabs; } |
| 133 | |
| 134 | private: |
| 135 | /* This function is mapped across the sections and remembers the |
| 136 | offset and size of each of the debugging sections we are |
| 137 | interested in. */ |
| 138 | void locate_sections (bfd *abfd, asection *sectp, |
| 139 | const dwarf2_debug_sections &names); |
| 140 | |
| 141 | public: |
| 142 | /* The corresponding BFD. */ |
| 143 | bfd *obfd; |
| 144 | |
| 145 | /* Objects that can be shared across objfiles are stored in this |
| 146 | obstack or on the psymtab obstack, while objects that are |
| 147 | objfile-specific are stored on the objfile obstack. */ |
| 148 | auto_obstack obstack; |
| 149 | |
| 150 | dwarf2_section_info info {}; |
| 151 | dwarf2_section_info abbrev {}; |
| 152 | dwarf2_section_info line {}; |
| 153 | dwarf2_section_info loc {}; |
| 154 | dwarf2_section_info loclists {}; |
| 155 | dwarf2_section_info macinfo {}; |
| 156 | dwarf2_section_info macro {}; |
| 157 | dwarf2_section_info str {}; |
| 158 | dwarf2_section_info str_offsets {}; |
| 159 | dwarf2_section_info line_str {}; |
| 160 | dwarf2_section_info ranges {}; |
| 161 | dwarf2_section_info rnglists {}; |
| 162 | dwarf2_section_info addr {}; |
| 163 | dwarf2_section_info frame {}; |
| 164 | dwarf2_section_info eh_frame {}; |
| 165 | dwarf2_section_info gdb_index {}; |
| 166 | dwarf2_section_info debug_names {}; |
| 167 | dwarf2_section_info debug_aranges {}; |
| 168 | |
| 169 | std::vector<dwarf2_section_info> types; |
| 170 | |
| 171 | /* Table of all the compilation units. This is used to locate |
| 172 | the target compilation unit of a particular reference. */ |
| 173 | std::vector<dwarf2_per_cu_data *> all_comp_units; |
| 174 | |
| 175 | /* The .debug_types-related CUs (TUs). */ |
| 176 | std::vector<signatured_type *> all_type_units; |
| 177 | |
| 178 | /* Table of struct type_unit_group objects. |
| 179 | The hash key is the DW_AT_stmt_list value. */ |
| 180 | htab_up type_unit_groups; |
| 181 | |
| 182 | /* A table mapping .debug_types signatures to its signatured_type entry. |
| 183 | This is NULL if the .debug_types section hasn't been read in yet. */ |
| 184 | htab_up signatured_types; |
| 185 | |
| 186 | /* Type unit statistics, to see how well the scaling improvements |
| 187 | are doing. */ |
| 188 | struct tu_stats tu_stats {}; |
| 189 | |
| 190 | /* A table mapping DW_AT_dwo_name values to struct dwo_file objects. |
| 191 | This is NULL if the table hasn't been allocated yet. */ |
| 192 | htab_up dwo_files; |
| 193 | |
| 194 | /* True if we've checked for whether there is a DWP file. */ |
| 195 | bool dwp_checked = false; |
| 196 | |
| 197 | /* The DWP file if there is one, or NULL. */ |
| 198 | std::unique_ptr<struct dwp_file> dwp_file; |
| 199 | |
| 200 | /* The shared '.dwz' file, if one exists. This is used when the |
| 201 | original data was compressed using 'dwz -m'. */ |
| 202 | std::unique_ptr<struct dwz_file> dwz_file; |
| 203 | |
| 204 | /* Whether copy relocations are supported by this object format. */ |
| 205 | bool can_copy; |
| 206 | |
| 207 | /* A flag indicating whether this objfile has a section loaded at a |
| 208 | VMA of 0. */ |
| 209 | bool has_section_at_zero = false; |
| 210 | |
| 211 | /* True if we are using the mapped index, |
| 212 | or we are faking it for OBJF_READNOW's sake. */ |
| 213 | bool using_index = false; |
| 214 | |
| 215 | /* The mapped index, or NULL if .gdb_index is missing or not being used. */ |
| 216 | std::unique_ptr<mapped_index> index_table; |
| 217 | |
| 218 | /* The mapped index, or NULL if .debug_names is missing or not being used. */ |
| 219 | std::unique_ptr<mapped_debug_names> debug_names_table; |
| 220 | |
| 221 | /* When using index_table, this keeps track of all quick_file_names entries. |
| 222 | TUs typically share line table entries with a CU, so we maintain a |
| 223 | separate table of all line table entries to support the sharing. |
| 224 | Note that while there can be way more TUs than CUs, we've already |
| 225 | sorted all the TUs into "type unit groups", grouped by their |
| 226 | DW_AT_stmt_list value. Therefore the only sharing done here is with a |
| 227 | CU and its associated TU group if there is one. */ |
| 228 | htab_up quick_file_names_table; |
| 229 | |
| 230 | /* Set during partial symbol reading, to prevent queueing of full |
| 231 | symbols. */ |
| 232 | bool reading_partial_symbols = false; |
| 233 | |
| 234 | /* The CUs we recently read. */ |
| 235 | std::vector<dwarf2_per_cu_data *> just_read_cus; |
| 236 | |
| 237 | /* Table containing all filenames. This is an optional because the |
| 238 | table is lazily constructed on first access. */ |
| 239 | gdb::optional<filename_seen_cache> filenames_cache; |
| 240 | |
| 241 | /* If we loaded the index from an external file, this contains the |
| 242 | resources associated to the open file, memory mapping, etc. */ |
| 243 | std::unique_ptr<index_cache_resource> index_cache_res; |
| 244 | |
| 245 | /* Mapping from abstract origin DIE to concrete DIEs that reference it as |
| 246 | DW_AT_abstract_origin. */ |
| 247 | std::unordered_map<sect_offset, std::vector<sect_offset>, |
| 248 | gdb::hash_enum<sect_offset>> |
| 249 | abstract_to_concrete; |
| 250 | |
| 251 | /* CUs that are queued to be read. */ |
| 252 | std::queue<dwarf2_queue_item> queue; |
| 253 | |
| 254 | /* We keep a separate reference to the partial symtabs, in case we |
| 255 | are sharing them between objfiles. This is only set after |
| 256 | partial symbols have been read the first time. */ |
| 257 | std::shared_ptr<psymtab_storage> partial_symtabs; |
| 258 | |
| 259 | private: |
| 260 | |
| 261 | /* The total number of per_cu and signatured_type objects that have |
| 262 | been created so far for this reader. */ |
| 263 | size_t m_num_psymtabs = 0; |
| 264 | }; |
| 265 | |
| 266 | /* This is the per-objfile data associated with a type_unit_group. */ |
| 267 | |
| 268 | struct type_unit_group_unshareable |
| 269 | { |
| 270 | /* The compunit symtab. |
| 271 | Type units in a group needn't all be defined in the same source file, |
| 272 | so we create an essentially anonymous symtab as the compunit symtab. */ |
| 273 | struct compunit_symtab *compunit_symtab = nullptr; |
| 274 | |
| 275 | /* The number of symtabs from the line header. |
| 276 | The value here must match line_header.num_file_names. */ |
| 277 | unsigned int num_symtabs = 0; |
| 278 | |
| 279 | /* The symbol tables for this TU (obtained from the files listed in |
| 280 | DW_AT_stmt_list). |
| 281 | WARNING: The order of entries here must match the order of entries |
| 282 | in the line header. After the first TU using this type_unit_group, the |
| 283 | line header for the subsequent TUs is recreated from this. This is done |
| 284 | because we need to use the same symtabs for each TU using the same |
| 285 | DW_AT_stmt_list value. Also note that symtabs may be repeated here, |
| 286 | there's no guarantee the line header doesn't have duplicate entries. */ |
| 287 | struct symtab **symtabs = nullptr; |
| 288 | }; |
| 289 | |
| 290 | /* Collection of data recorded per objfile. |
| 291 | This hangs off of dwarf2_objfile_data_key. |
| 292 | |
| 293 | Some DWARF data cannot (currently) be shared across objfiles. Such |
| 294 | data is stored in this object. */ |
| 295 | |
| 296 | struct dwarf2_per_objfile |
| 297 | { |
| 298 | dwarf2_per_objfile (struct objfile *objfile, dwarf2_per_bfd *per_bfd) |
| 299 | : objfile (objfile), per_bfd (per_bfd) |
| 300 | {} |
| 301 | |
| 302 | ~dwarf2_per_objfile (); |
| 303 | |
| 304 | /* Return pointer to string at .debug_line_str offset as read from BUF. |
| 305 | BUF is assumed to be in a compilation unit described by CU_HEADER. |
| 306 | Return *BYTES_READ_PTR count of bytes read from BUF. */ |
| 307 | const char *read_line_string (const gdb_byte *buf, |
| 308 | const struct comp_unit_head *cu_header, |
| 309 | unsigned int *bytes_read_ptr); |
| 310 | |
| 311 | /* Resize the M_SYMTABS vector to the needed size (the number of partial |
| 312 | symtabs allocated by the per-bfd). */ |
| 313 | void resize_symtabs () |
| 314 | { |
| 315 | /* The symtabs vector should only grow, not shrink. */ |
| 316 | gdb_assert (per_bfd->num_psymtabs () >= m_symtabs.size ()); |
| 317 | |
| 318 | m_symtabs.resize (per_bfd->num_psymtabs ()); |
| 319 | } |
| 320 | |
| 321 | /* Return true if the symtab corresponding to PER_CU has been set, |
| 322 | false otherwise. */ |
| 323 | bool symtab_set_p (const dwarf2_per_cu_data *per_cu) const; |
| 324 | |
| 325 | /* Return the compunit_symtab associated to PER_CU, if it has been created. */ |
| 326 | compunit_symtab *get_symtab (const dwarf2_per_cu_data *per_cu) const; |
| 327 | |
| 328 | /* Set the compunit_symtab associated to PER_CU. */ |
| 329 | void set_symtab (const dwarf2_per_cu_data *per_cu, compunit_symtab *symtab); |
| 330 | |
| 331 | /* Get the type_unit_group_unshareable corresponding to TU_GROUP. If one |
| 332 | does not exist, create it. */ |
| 333 | type_unit_group_unshareable *get_type_unit_group_unshareable |
| 334 | (type_unit_group *tu_group); |
| 335 | |
| 336 | struct type *get_type_for_signatured_type (signatured_type *sig_type) const; |
| 337 | |
| 338 | void set_type_for_signatured_type (signatured_type *sig_type, |
| 339 | struct type *type); |
| 340 | |
| 341 | /* Find an integer type SIZE_IN_BYTES bytes in size and return it. |
| 342 | UNSIGNED_P controls if the integer is unsigned or not. */ |
| 343 | struct type *int_type (int size_in_bytes, bool unsigned_p) const; |
| 344 | |
| 345 | /* Get the dwarf2_cu matching PER_CU for this objfile. */ |
| 346 | dwarf2_cu *get_cu (dwarf2_per_cu_data *per_cu); |
| 347 | |
| 348 | /* Set the dwarf2_cu matching PER_CU for this objfile. */ |
| 349 | void set_cu (dwarf2_per_cu_data *per_cu, dwarf2_cu *cu); |
| 350 | |
| 351 | /* Remove/free the dwarf2_cu matching PER_CU for this objfile. */ |
| 352 | void remove_cu (dwarf2_per_cu_data *per_cu); |
| 353 | |
| 354 | /* Free all cached compilation units. */ |
| 355 | void remove_all_cus (); |
| 356 | |
| 357 | /* Increase the age counter on each CU compilation unit and free |
| 358 | any that are too old. */ |
| 359 | void age_comp_units (); |
| 360 | |
| 361 | /* Back link. */ |
| 362 | struct objfile *objfile; |
| 363 | |
| 364 | /* Pointer to the data that is (possibly) shared between this objfile and |
| 365 | other objfiles backed by the same BFD. */ |
| 366 | struct dwarf2_per_bfd *per_bfd; |
| 367 | |
| 368 | /* Table mapping type DIEs to their struct type *. |
| 369 | This is nullptr if not allocated yet. |
| 370 | The mapping is done via (CU/TU + DIE offset) -> type. */ |
| 371 | htab_up die_type_hash; |
| 372 | |
| 373 | /* Table containing line_header indexed by offset and offset_in_dwz. */ |
| 374 | htab_up line_header_hash; |
| 375 | |
| 376 | private: |
| 377 | /* Hold the corresponding compunit_symtab for each CU or TU. This |
| 378 | is indexed by dwarf2_per_cu_data::index. A NULL value means |
| 379 | that the CU/TU has not been expanded yet. */ |
| 380 | std::vector<compunit_symtab *> m_symtabs; |
| 381 | |
| 382 | /* Map from a type unit group to the corresponding unshared |
| 383 | structure. */ |
| 384 | typedef std::unique_ptr<type_unit_group_unshareable> |
| 385 | type_unit_group_unshareable_up; |
| 386 | |
| 387 | std::unordered_map<type_unit_group *, type_unit_group_unshareable_up> |
| 388 | m_type_units; |
| 389 | |
| 390 | /* Map from signatured types to the corresponding struct type. */ |
| 391 | std::unordered_map<signatured_type *, struct type *> m_type_map; |
| 392 | |
| 393 | /* Map from the objfile-independent dwarf2_per_cu_data instances to the |
| 394 | corresponding objfile-dependent dwarf2_cu instances. */ |
| 395 | std::unordered_map<dwarf2_per_cu_data *, dwarf2_cu *> m_dwarf2_cus; |
| 396 | }; |
| 397 | |
| 398 | /* Get the dwarf2_per_objfile associated to OBJFILE. */ |
| 399 | |
| 400 | dwarf2_per_objfile *get_dwarf2_per_objfile (struct objfile *objfile); |
| 401 | |
| 402 | /* A partial symtab specialized for DWARF. */ |
| 403 | struct dwarf2_psymtab : public partial_symtab |
| 404 | { |
| 405 | dwarf2_psymtab (const char *filename, struct objfile *objfile, |
| 406 | dwarf2_per_cu_data *per_cu) |
| 407 | : partial_symtab (filename, objfile, 0), |
| 408 | per_cu_data (per_cu) |
| 409 | { |
| 410 | } |
| 411 | |
| 412 | void read_symtab (struct objfile *) override; |
| 413 | void expand_psymtab (struct objfile *) override; |
| 414 | bool readin_p (struct objfile *) const override; |
| 415 | compunit_symtab *get_compunit_symtab (struct objfile *) const override; |
| 416 | |
| 417 | struct dwarf2_per_cu_data *per_cu_data; |
| 418 | }; |
| 419 | |
| 420 | /* Persistent data held for a compilation unit, even when not |
| 421 | processing it. We put a pointer to this structure in the |
| 422 | psymtab. */ |
| 423 | |
| 424 | struct dwarf2_per_cu_data |
| 425 | { |
| 426 | /* The start offset and length of this compilation unit. |
| 427 | NOTE: Unlike comp_unit_head.length, this length includes |
| 428 | initial_length_size. |
| 429 | If the DIE refers to a DWO file, this is always of the original die, |
| 430 | not the DWO file. */ |
| 431 | sect_offset sect_off; |
| 432 | unsigned int length; |
| 433 | |
| 434 | /* DWARF standard version this data has been read from (such as 4 or 5). */ |
| 435 | short dwarf_version; |
| 436 | |
| 437 | /* Flag indicating this compilation unit will be read in before |
| 438 | any of the current compilation units are processed. */ |
| 439 | unsigned int queued : 1; |
| 440 | |
| 441 | /* This flag will be set when reading partial DIEs if we need to load |
| 442 | absolutely all DIEs for this compilation unit, instead of just the ones |
| 443 | we think are interesting. It gets set if we look for a DIE in the |
| 444 | hash table and don't find it. */ |
| 445 | unsigned int load_all_dies : 1; |
| 446 | |
| 447 | /* Non-zero if this CU is from .debug_types. |
| 448 | Struct dwarf2_per_cu_data is contained in struct signatured_type iff |
| 449 | this is non-zero. */ |
| 450 | unsigned int is_debug_types : 1; |
| 451 | |
| 452 | /* Non-zero if this CU is from the .dwz file. */ |
| 453 | unsigned int is_dwz : 1; |
| 454 | |
| 455 | /* Non-zero if reading a TU directly from a DWO file, bypassing the stub. |
| 456 | This flag is only valid if is_debug_types is true. |
| 457 | We can't read a CU directly from a DWO file: There are required |
| 458 | attributes in the stub. */ |
| 459 | unsigned int reading_dwo_directly : 1; |
| 460 | |
| 461 | /* Non-zero if the TU has been read. |
| 462 | This is used to assist the "Stay in DWO Optimization" for Fission: |
| 463 | When reading a DWO, it's faster to read TUs from the DWO instead of |
| 464 | fetching them from random other DWOs (due to comdat folding). |
| 465 | If the TU has already been read, the optimization is unnecessary |
| 466 | (and unwise - we don't want to change where gdb thinks the TU lives |
| 467 | "midflight"). |
| 468 | This flag is only valid if is_debug_types is true. */ |
| 469 | unsigned int tu_read : 1; |
| 470 | |
| 471 | /* Our index in the unshared "symtabs" vector. */ |
| 472 | unsigned index; |
| 473 | |
| 474 | /* The section this CU/TU lives in. |
| 475 | If the DIE refers to a DWO file, this is always the original die, |
| 476 | not the DWO file. */ |
| 477 | struct dwarf2_section_info *section; |
| 478 | |
| 479 | /* The unit type of this CU. */ |
| 480 | enum dwarf_unit_type unit_type; |
| 481 | |
| 482 | /* The language of this CU. */ |
| 483 | enum language lang; |
| 484 | |
| 485 | /* Backlink to the owner of this. */ |
| 486 | dwarf2_per_bfd *per_bfd; |
| 487 | |
| 488 | /* DWARF header of this CU. Note that dwarf2_cu reads its own version of the |
| 489 | header, which may differ from this one, since it may pass rcuh_kind::TYPE |
| 490 | to read_comp_unit_head, whereas for dwarf2_per_cu_data we always pass |
| 491 | rcuh_kind::COMPILE. |
| 492 | |
| 493 | Don't access this field directly, use the get_header method instead. It |
| 494 | should be private, but we can't make it private at the moment. */ |
| 495 | mutable comp_unit_head m_header; |
| 496 | |
| 497 | /* True if HEADER has been read in. |
| 498 | |
| 499 | Don't access this field directly. It should be private, but we can't make |
| 500 | it private at the moment. */ |
| 501 | mutable bool m_header_read_in; |
| 502 | |
| 503 | /* When dwarf2_per_bfd::using_index is true, the 'quick' field |
| 504 | is active. Otherwise, the 'psymtab' field is active. */ |
| 505 | union |
| 506 | { |
| 507 | /* The partial symbol table associated with this compilation unit, |
| 508 | or NULL for unread partial units. */ |
| 509 | dwarf2_psymtab *psymtab; |
| 510 | |
| 511 | /* Data needed by the "quick" functions. */ |
| 512 | struct dwarf2_per_cu_quick_data *quick; |
| 513 | } v; |
| 514 | |
| 515 | /* The CUs we import using DW_TAG_imported_unit. This is filled in |
| 516 | while reading psymtabs, used to compute the psymtab dependencies, |
| 517 | and then cleared. Then it is filled in again while reading full |
| 518 | symbols, and only deleted when the objfile is destroyed. |
| 519 | |
| 520 | This is also used to work around a difference between the way gold |
| 521 | generates .gdb_index version <=7 and the way gdb does. Arguably this |
| 522 | is a gold bug. For symbols coming from TUs, gold records in the index |
| 523 | the CU that includes the TU instead of the TU itself. This breaks |
| 524 | dw2_lookup_symbol: It assumes that if the index says symbol X lives |
| 525 | in CU/TU Y, then one need only expand Y and a subsequent lookup in Y |
| 526 | will find X. Alas TUs live in their own symtab, so after expanding CU Y |
| 527 | we need to look in TU Z to find X. Fortunately, this is akin to |
| 528 | DW_TAG_imported_unit, so we just use the same mechanism: For |
| 529 | .gdb_index version <=7 this also records the TUs that the CU referred |
| 530 | to. Concurrently with this change gdb was modified to emit version 8 |
| 531 | indices so we only pay a price for gold generated indices. |
| 532 | http://sourceware.org/bugzilla/show_bug.cgi?id=15021. |
| 533 | |
| 534 | This currently needs to be a public member due to how |
| 535 | dwarf2_per_cu_data is allocated and used. Ideally in future things |
| 536 | could be refactored to make this private. Until then please try to |
| 537 | avoid direct access to this member, and instead use the helper |
| 538 | functions above. */ |
| 539 | std::vector <dwarf2_per_cu_data *> *imported_symtabs; |
| 540 | |
| 541 | /* Return true of IMPORTED_SYMTABS is empty or not yet allocated. */ |
| 542 | bool imported_symtabs_empty () const |
| 543 | { |
| 544 | return (imported_symtabs == nullptr || imported_symtabs->empty ()); |
| 545 | } |
| 546 | |
| 547 | /* Push P to the back of IMPORTED_SYMTABS, allocated IMPORTED_SYMTABS |
| 548 | first if required. */ |
| 549 | void imported_symtabs_push (dwarf2_per_cu_data *p) |
| 550 | { |
| 551 | if (imported_symtabs == nullptr) |
| 552 | imported_symtabs = new std::vector <dwarf2_per_cu_data *>; |
| 553 | imported_symtabs->push_back (p); |
| 554 | } |
| 555 | |
| 556 | /* Return the size of IMPORTED_SYMTABS if it is allocated, otherwise |
| 557 | return 0. */ |
| 558 | size_t imported_symtabs_size () const |
| 559 | { |
| 560 | if (imported_symtabs == nullptr) |
| 561 | return 0; |
| 562 | return imported_symtabs->size (); |
| 563 | } |
| 564 | |
| 565 | /* Delete IMPORTED_SYMTABS and set the pointer back to nullptr. */ |
| 566 | void imported_symtabs_free () |
| 567 | { |
| 568 | delete imported_symtabs; |
| 569 | imported_symtabs = nullptr; |
| 570 | } |
| 571 | |
| 572 | /* Get the header of this per_cu, reading it if necessary. */ |
| 573 | const comp_unit_head *get_header () const; |
| 574 | |
| 575 | /* Return the address size given in the compilation unit header for |
| 576 | this CU. */ |
| 577 | int addr_size () const; |
| 578 | |
| 579 | /* Return the offset size given in the compilation unit header for |
| 580 | this CU. */ |
| 581 | int offset_size () const; |
| 582 | |
| 583 | /* Return the DW_FORM_ref_addr size given in the compilation unit |
| 584 | header for this CU. */ |
| 585 | int ref_addr_size () const; |
| 586 | |
| 587 | /* Return DWARF version number of this CU. */ |
| 588 | short version () const |
| 589 | { |
| 590 | return dwarf_version; |
| 591 | } |
| 592 | |
| 593 | /* A type unit group has a per_cu object that is recognized by |
| 594 | having no section. */ |
| 595 | bool type_unit_group_p () const |
| 596 | { |
| 597 | return section == nullptr; |
| 598 | } |
| 599 | }; |
| 600 | |
| 601 | /* Entry in the signatured_types hash table. */ |
| 602 | |
| 603 | struct signatured_type |
| 604 | { |
| 605 | /* The "per_cu" object of this type. |
| 606 | This struct is used iff per_cu.is_debug_types. |
| 607 | N.B.: This is the first member so that it's easy to convert pointers |
| 608 | between them. */ |
| 609 | struct dwarf2_per_cu_data per_cu; |
| 610 | |
| 611 | /* The type's signature. */ |
| 612 | ULONGEST signature; |
| 613 | |
| 614 | /* Offset in the TU of the type's DIE, as read from the TU header. |
| 615 | If this TU is a DWO stub and the definition lives in a DWO file |
| 616 | (specified by DW_AT_GNU_dwo_name), this value is unusable. */ |
| 617 | cu_offset type_offset_in_tu; |
| 618 | |
| 619 | /* Offset in the section of the type's DIE. |
| 620 | If the definition lives in a DWO file, this is the offset in the |
| 621 | .debug_types.dwo section. |
| 622 | The value is zero until the actual value is known. |
| 623 | Zero is otherwise not a valid section offset. */ |
| 624 | sect_offset type_offset_in_section; |
| 625 | |
| 626 | /* Type units are grouped by their DW_AT_stmt_list entry so that they |
| 627 | can share them. This points to the containing symtab. */ |
| 628 | struct type_unit_group *type_unit_group; |
| 629 | |
| 630 | /* Containing DWO unit. |
| 631 | This field is valid iff per_cu.reading_dwo_directly. */ |
| 632 | struct dwo_unit *dwo_unit; |
| 633 | }; |
| 634 | |
| 635 | /* Open the separate '.dwz' debug file, if needed. Return NULL if |
| 636 | there is no .gnu_debugaltlink section in the file. Error if there |
| 637 | is such a section but the file cannot be found. */ |
| 638 | |
| 639 | extern dwz_file *dwarf2_get_dwz_file (dwarf2_per_bfd *per_bfd); |
| 640 | |
| 641 | /* Return the type of the DIE at DIE_OFFSET in the CU named by |
| 642 | PER_CU. */ |
| 643 | |
| 644 | struct type *dwarf2_get_die_type (cu_offset die_offset, |
| 645 | dwarf2_per_cu_data *per_cu, |
| 646 | dwarf2_per_objfile *per_objfile); |
| 647 | |
| 648 | /* Given an index in .debug_addr, fetch the value. |
| 649 | NOTE: This can be called during dwarf expression evaluation, |
| 650 | long after the debug information has been read, and thus per_cu->cu |
| 651 | may no longer exist. */ |
| 652 | |
| 653 | CORE_ADDR dwarf2_read_addr_index (dwarf2_per_cu_data *per_cu, |
| 654 | dwarf2_per_objfile *per_objfile, |
| 655 | unsigned int addr_index); |
| 656 | |
| 657 | /* Return DWARF block referenced by DW_AT_location of DIE at SECT_OFF at PER_CU. |
| 658 | Returned value is intended for DW_OP_call*. Returned |
| 659 | dwarf2_locexpr_baton->data has lifetime of |
| 660 | PER_CU->DWARF2_PER_OBJFILE->OBJFILE. */ |
| 661 | |
| 662 | struct dwarf2_locexpr_baton dwarf2_fetch_die_loc_sect_off |
| 663 | (sect_offset sect_off, dwarf2_per_cu_data *per_cu, |
| 664 | dwarf2_per_objfile *per_objfile, |
| 665 | CORE_ADDR (*get_frame_pc) (void *baton), |
| 666 | void *baton, bool resolve_abstract_p = false); |
| 667 | |
| 668 | /* Like dwarf2_fetch_die_loc_sect_off, but take a CU |
| 669 | offset. */ |
| 670 | |
| 671 | struct dwarf2_locexpr_baton dwarf2_fetch_die_loc_cu_off |
| 672 | (cu_offset offset_in_cu, dwarf2_per_cu_data *per_cu, |
| 673 | dwarf2_per_objfile *per_objfile, |
| 674 | CORE_ADDR (*get_frame_pc) (void *baton), |
| 675 | void *baton); |
| 676 | |
| 677 | /* If the DIE at SECT_OFF in PER_CU has a DW_AT_const_value, return a |
| 678 | pointer to the constant bytes and set LEN to the length of the |
| 679 | data. If memory is needed, allocate it on OBSTACK. If the DIE |
| 680 | does not have a DW_AT_const_value, return NULL. */ |
| 681 | |
| 682 | extern const gdb_byte *dwarf2_fetch_constant_bytes |
| 683 | (sect_offset sect_off, dwarf2_per_cu_data *per_cu, |
| 684 | dwarf2_per_objfile *per_objfile, obstack *obstack, |
| 685 | LONGEST *len); |
| 686 | |
| 687 | /* Return the type of the die at SECT_OFF in PER_CU. Return NULL if no |
| 688 | valid type for this die is found. */ |
| 689 | |
| 690 | struct type *dwarf2_fetch_die_type_sect_off |
| 691 | (sect_offset sect_off, dwarf2_per_cu_data *per_cu, |
| 692 | dwarf2_per_objfile *per_objfile); |
| 693 | |
| 694 | /* When non-zero, dump line number entries as they are read in. */ |
| 695 | extern unsigned int dwarf_line_debug; |
| 696 | |
| 697 | #endif /* DWARF2READ_H */ |