1 /* bfdlink.h -- header file for BFD link routines 2 Copyright 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 3 2003, 2004, 2005 Free Software Foundation, Inc. 4 Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support. 5 6 This file is part of BFD, the Binary File Descriptor library. 7 8 This program is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 2 of the License, or 11 (at your option) any later version. 12 13 This program is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program; if not, write to the Free Software 20 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ 21 22 #ifndef BFDLINK_H 23 #define BFDLINK_H 24 25 /* Which symbols to strip during a link. */ 26 enum bfd_link_strip 27 { 28 strip_none, /* Don't strip any symbols. */ 29 strip_debugger, /* Strip debugging symbols. */ 30 strip_some, /* keep_hash is the list of symbols to keep. */ 31 strip_all /* Strip all symbols. */ 32 }; 33 34 /* Which local symbols to discard during a link. This is irrelevant 35 if strip_all is used. */ 36 enum bfd_link_discard 37 { 38 discard_sec_merge, /* Discard local temporary symbols in SEC_MERGE 39 sections. */ 40 discard_none, /* Don't discard any locals. */ 41 discard_l, /* Discard local temporary symbols. */ 42 discard_all /* Discard all locals. */ 43 }; 44 45 /* Describes the type of hash table entry structure being used. 46 Different hash table structure have different fields and so 47 support different linking features. */ 48 enum bfd_link_hash_table_type 49 { 50 bfd_link_generic_hash_table, 51 bfd_link_elf_hash_table 52 }; 53 54 /* These are the possible types of an entry in the BFD link hash 55 table. */ 56 57 enum bfd_link_hash_type 58 { 59 bfd_link_hash_new, /* Symbol is new. */ 60 bfd_link_hash_undefined, /* Symbol seen before, but undefined. */ 61 bfd_link_hash_undefweak, /* Symbol is weak and undefined. */ 62 bfd_link_hash_defined, /* Symbol is defined. */ 63 bfd_link_hash_defweak, /* Symbol is weak and defined. */ 64 bfd_link_hash_common, /* Symbol is common. */ 65 bfd_link_hash_indirect, /* Symbol is an indirect link. */ 66 bfd_link_hash_warning /* Like indirect, but warn if referenced. */ 67 }; 68 69 enum bfd_link_common_skip_ar_aymbols 70 { 71 bfd_link_common_skip_none, 72 bfd_link_common_skip_text, 73 bfd_link_common_skip_data, 74 bfd_link_common_skip_all 75 }; 76 77 /* The linking routines use a hash table which uses this structure for 78 its elements. */ 79 80 struct bfd_link_hash_entry 81 { 82 /* Base hash table entry structure. */ 83 struct bfd_hash_entry root; 84 85 /* Type of this entry. */ 86 enum bfd_link_hash_type type; 87 88 /* A union of information depending upon the type. */ 89 union 90 { 91 /* Nothing is kept for bfd_hash_new. */ 92 /* bfd_link_hash_undefined, bfd_link_hash_undefweak. */ 93 struct 94 { 95 /* Undefined and common symbols are kept in a linked list through 96 this field. This field is present in all of the union element 97 so that we don't need to remove entries from the list when we 98 change their type. Removing entries would either require the 99 list to be doubly linked, which would waste more memory, or 100 require a traversal. When an undefined or common symbol is 101 created, it should be added to this list, the head of which is in 102 the link hash table itself. As symbols are defined, they need 103 not be removed from the list; anything which reads the list must 104 doublecheck the symbol type. 105 106 Weak symbols are not kept on this list. 107 108 Defined and defweak symbols use this field as a reference marker. 109 If the field is not NULL, or this structure is the tail of the 110 undefined symbol list, the symbol has been referenced. If the 111 symbol is undefined and becomes defined, this field will 112 automatically be non-NULL since the symbol will have been on the 113 undefined symbol list. */ 114 struct bfd_link_hash_entry *next; 115 bfd *abfd; /* BFD symbol was found in. */ 116 bfd *weak; /* BFD weak symbol was found in. */ 117 } undef; 118 /* bfd_link_hash_defined, bfd_link_hash_defweak. */ 119 struct 120 { 121 struct bfd_link_hash_entry *next; 122 asection *section; /* Symbol section. */ 123 bfd_vma value; /* Symbol value. */ 124 } def; 125 /* bfd_link_hash_indirect, bfd_link_hash_warning. */ 126 struct 127 { 128 struct bfd_link_hash_entry *next; 129 struct bfd_link_hash_entry *link; /* Real symbol. */ 130 const char *warning; /* Warning (bfd_link_hash_warning only). */ 131 } i; 132 /* bfd_link_hash_common. */ 133 struct 134 { 135 struct bfd_link_hash_entry *next; 136 /* The linker needs to know three things about common 137 symbols: the size, the alignment, and the section in 138 which the symbol should be placed. We store the size 139 here, and we allocate a small structure to hold the 140 section and the alignment. The alignment is stored as a 141 power of two. We don't store all the information 142 directly because we don't want to increase the size of 143 the union; this structure is a major space user in the 144 linker. */ 145 struct bfd_link_hash_common_entry 146 { 147 unsigned int alignment_power; /* Alignment. */ 148 asection *section; /* Symbol section. */ 149 } *p; 150 bfd_size_type size; /* Common symbol size. */ 151 } c; 152 } u; 153 }; 154 155 /* This is the link hash table. It is a derived class of 156 bfd_hash_table. */ 157 158 struct bfd_link_hash_table 159 { 160 /* The hash table itself. */ 161 struct bfd_hash_table table; 162 /* The back end which created this hash table. This indicates the 163 type of the entries in the hash table, which is sometimes 164 important information when linking object files of different 165 types together. */ 166 const bfd_target *creator; 167 /* A linked list of undefined and common symbols, linked through the 168 next field in the bfd_link_hash_entry structure. */ 169 struct bfd_link_hash_entry *undefs; 170 /* Entries are added to the tail of the undefs list. */ 171 struct bfd_link_hash_entry *undefs_tail; 172 /* The type of the link hash table. */ 173 enum bfd_link_hash_table_type type; 174 }; 175 176 /* Look up an entry in a link hash table. If FOLLOW is TRUE, this 177 follows bfd_link_hash_indirect and bfd_link_hash_warning links to 178 the real symbol. */ 179 extern struct bfd_link_hash_entry *bfd_link_hash_lookup 180 (struct bfd_link_hash_table *, const char *, bfd_boolean create, 181 bfd_boolean copy, bfd_boolean follow); 182 183 /* Look up an entry in the main linker hash table if the symbol might 184 be wrapped. This should only be used for references to an 185 undefined symbol, not for definitions of a symbol. */ 186 187 extern struct bfd_link_hash_entry *bfd_wrapped_link_hash_lookup 188 (bfd *, struct bfd_link_info *, const char *, bfd_boolean, 189 bfd_boolean, bfd_boolean); 190 191 /* Traverse a link hash table. */ 192 extern void bfd_link_hash_traverse 193 (struct bfd_link_hash_table *, 194 bfd_boolean (*) (struct bfd_link_hash_entry *, void *), 195 void *); 196 197 /* Add an entry to the undefs list. */ 198 extern void bfd_link_add_undef 199 (struct bfd_link_hash_table *, struct bfd_link_hash_entry *); 200 201 /* Remove symbols from the undefs list that don't belong there. */ 202 extern void bfd_link_repair_undef_list 203 (struct bfd_link_hash_table *table); 204 205 struct bfd_sym_chain 206 { 207 struct bfd_sym_chain *next; 208 const char *name; 209 }; 210 211 /* How to handle unresolved symbols. 212 There are four possibilities which are enumerated below: */ 213 enum report_method 214 { 215 /* This is the initial value when then link_info structure is created. 216 It allows the various stages of the linker to determine whether they 217 allowed to set the value. */ 218 RM_NOT_YET_SET = 0, 219 RM_IGNORE, 220 RM_GENERATE_WARNING, 221 RM_GENERATE_ERROR 222 }; 223 224 /* This structure holds all the information needed to communicate 225 between BFD and the linker when doing a link. */ 226 227 struct bfd_link_info 228 { 229 /* TRUE if BFD should generate a relocatable object file. */ 230 unsigned int relocatable: 1; 231 232 /* TRUE if BFD should generate relocation information in the final 233 executable. */ 234 unsigned int emitrelocations: 1; 235 236 /* TRUE if BFD should generate a "task linked" object file, 237 similar to relocatable but also with globals converted to 238 statics. */ 239 unsigned int task_link: 1; 240 241 /* TRUE if BFD should generate a shared object. */ 242 unsigned int shared: 1; 243 244 /* TRUE if BFD should pre-bind symbols in a shared object. */ 245 unsigned int symbolic: 1; 246 247 /* TRUE if BFD should export all symbols in the dynamic symbol table 248 of an executable, rather than only those used. */ 249 unsigned int export_dynamic: 1; 250 251 /* TRUE if shared objects should be linked directly, not shared. */ 252 unsigned int static_link: 1; 253 254 /* TRUE if the output file should be in a traditional format. This 255 is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag 256 on the output file, but may be checked when reading the input 257 files. */ 258 unsigned int traditional_format: 1; 259 260 /* TRUE if we want to produced optimized output files. This might 261 need much more time and therefore must be explicitly selected. */ 262 unsigned int optimize: 1; 263 264 /* TRUE if ok to have multiple definition. */ 265 unsigned int allow_multiple_definition: 1; 266 267 /* TRUE if output program should be marked to request W^X permission */ 268 unsigned int execute_only: 1; 269 270 /* TRUE if output program should be marked to request W^X permission */ 271 unsigned int wxneeded: 1; 272 273 /* TRUE if output program should be marked to stop branch target CFI enforcement */ 274 unsigned int nobtcfi: 1; 275 276 /* TRUE if ok to have version with no definition. */ 277 unsigned int allow_undefined_version: 1; 278 279 /* TRUE if ok to have text relocations. */ 280 unsigned int allow_textrel: 1; 281 282 /* TRUE if a default symbol version should be created and used for 283 exported symbols. */ 284 unsigned int create_default_symver: 1; 285 286 /* TRUE if a default symbol version should be created and used for 287 imported symbols. */ 288 unsigned int default_imported_symver: 1; 289 290 /* TRUE if symbols should be retained in memory, FALSE if they 291 should be freed and reread. */ 292 unsigned int keep_memory: 1; 293 294 /* TRUE if every symbol should be reported back via the notice 295 callback. */ 296 unsigned int notice_all: 1; 297 298 /* TRUE if executable should not contain copy relocs. 299 Setting this true may result in a non-sharable text segment. */ 300 unsigned int nocopyreloc: 1; 301 302 /* TRUE if the new ELF dynamic tags are enabled. */ 303 unsigned int new_dtags: 1; 304 305 /* TRUE if non-PLT relocs should be merged into one reloc section 306 and sorted so that relocs against the same symbol come together. */ 307 unsigned int combreloc: 1; 308 309 /* TRUE if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment 310 should be created. */ 311 unsigned int eh_frame_hdr: 1; 312 313 /* TRUE if global symbols in discarded sections should be stripped. */ 314 unsigned int strip_discarded: 1; 315 316 /* TRUE if generating a position independent executable. */ 317 unsigned int pie: 1; 318 319 /* TRUE if generating an executable, position independent or not. */ 320 unsigned int executable : 1; 321 322 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X 323 flags. */ 324 unsigned int execstack: 1; 325 326 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W 327 flags. */ 328 unsigned int noexecstack: 1; 329 330 /* TRUE if PT_GNU_RELRO segment should be created. */ 331 unsigned int relro: 1; 332 333 /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */ 334 unsigned int warn_shared_textrel: 1; 335 336 /* TRUE if unreferenced sections should be removed. */ 337 unsigned int gc_sections: 1; 338 339 /* If TRUE reduce memory overheads, at the expense of speed. This will 340 cause map file generation to use an O(N^2) algorithm and disable 341 caching ELF symbol buffer. */ 342 unsigned int reduce_memory_overheads: 1; 343 344 /* TRUE if .hash section should be created. */ 345 unsigned int emit_hash: 1; 346 347 /* TRUE if .gnu.hash section should be created. */ 348 unsigned int emit_gnu_hash: 1; 349 350 /* What to do with unresolved symbols in an object file. 351 When producing executables the default is GENERATE_ERROR. 352 When producing shared libraries the default is IGNORE. The 353 assumption with shared libraries is that the reference will be 354 resolved at load/execution time. */ 355 enum report_method unresolved_syms_in_objects; 356 357 /* What to do with unresolved symbols in a shared library. 358 The same defaults apply. */ 359 enum report_method unresolved_syms_in_shared_libs; 360 361 /* Which symbols to strip. */ 362 enum bfd_link_strip strip; 363 364 /* Which local symbols to discard. */ 365 enum bfd_link_discard discard; 366 367 /* Criteria for skipping symbols when detemining 368 whether to include an object from an archive. */ 369 enum bfd_link_common_skip_ar_aymbols common_skip_ar_aymbols; 370 371 /* Char that may appear as the first char of a symbol, but should be 372 skipped (like symbol_leading_char) when looking up symbols in 373 wrap_hash. Used by PowerPC Linux for 'dot' symbols. */ 374 char wrap_char; 375 376 /* Function callbacks. */ 377 const struct bfd_link_callbacks *callbacks; 378 379 /* Hash table handled by BFD. */ 380 struct bfd_link_hash_table *hash; 381 382 /* Hash table of symbols to keep. This is NULL unless strip is 383 strip_some. */ 384 struct bfd_hash_table *keep_hash; 385 386 /* Hash table of symbols to report back via the notice callback. If 387 this is NULL, and notice_all is FALSE, then no symbols are 388 reported back. */ 389 struct bfd_hash_table *notice_hash; 390 391 /* Hash table of symbols which are being wrapped (the --wrap linker 392 option). If this is NULL, no symbols are being wrapped. */ 393 struct bfd_hash_table *wrap_hash; 394 395 /* The list of input BFD's involved in the link. These are chained 396 together via the link_next field. */ 397 bfd *input_bfds; 398 399 /* If a symbol should be created for each input BFD, this is section 400 where those symbols should be placed. It must be a section in 401 the output BFD. It may be NULL, in which case no such symbols 402 will be created. This is to support CREATE_OBJECT_SYMBOLS in the 403 linker command language. */ 404 asection *create_object_symbols_section; 405 406 /* List of global symbol names that are starting points for marking 407 sections against garbage collection. */ 408 struct bfd_sym_chain *gc_sym_list; 409 410 /* If a base output file is wanted, then this points to it */ 411 void *base_file; 412 413 /* The function to call when the executable or shared object is 414 loaded. */ 415 const char *init_function; 416 417 /* The function to call when the executable or shared object is 418 unloaded. */ 419 const char *fini_function; 420 421 /* Number of relaxation passes. Usually only one relaxation pass 422 is needed. But a backend can have as many relaxation passes as 423 necessary. During bfd_relax_section call, it is set to the 424 current pass, starting from 0. */ 425 int relax_pass; 426 427 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs 428 should be generated/linked against. Set to 1 if this feature 429 is explicitly requested by the user, -1 if enabled by default. */ 430 int pei386_auto_import; 431 432 /* Non-zero if runtime relocs for DATA items with non-zero addends 433 in pei386 DLLs should be generated. Set to 1 if this feature 434 is explicitly requested by the user, -1 if enabled by default. */ 435 int pei386_runtime_pseudo_reloc; 436 437 /* How many spare .dynamic DT_NULL entries should be added? */ 438 unsigned int spare_dynamic_tags; 439 440 /* May be used to set DT_FLAGS for ELF. */ 441 bfd_vma flags; 442 443 /* May be used to set DT_FLAGS_1 for ELF. */ 444 bfd_vma flags_1; 445 446 /* Start and end of RELRO region. */ 447 bfd_vma relro_start, relro_end; 448 }; 449 450 /* This structures holds a set of callback functions. These are 451 called by the BFD linker routines. Except for einfo, the first 452 argument to each callback function is the bfd_link_info structure 453 being used and each function returns a boolean value. If the 454 function returns FALSE, then the BFD function which called it should 455 return with a failure indication. */ 456 457 struct bfd_link_callbacks 458 { 459 /* A function which is called when an object is added from an 460 archive. ABFD is the archive element being added. NAME is the 461 name of the symbol which caused the archive element to be pulled 462 in. */ 463 bfd_boolean (*add_archive_element) 464 (struct bfd_link_info *, bfd *abfd, const char *name); 465 /* A function which is called when a symbol is found with multiple 466 definitions. NAME is the symbol which is defined multiple times. 467 OBFD is the old BFD, OSEC is the old section, OVAL is the old 468 value, NBFD is the new BFD, NSEC is the new section, and NVAL is 469 the new value. OBFD may be NULL. OSEC and NSEC may be 470 bfd_com_section or bfd_ind_section. */ 471 bfd_boolean (*multiple_definition) 472 (struct bfd_link_info *, const char *name, 473 bfd *obfd, asection *osec, bfd_vma oval, 474 bfd *nbfd, asection *nsec, bfd_vma nval); 475 /* A function which is called when a common symbol is defined 476 multiple times. NAME is the symbol appearing multiple times. 477 OBFD is the BFD of the existing symbol; it may be NULL if this is 478 not known. OTYPE is the type of the existing symbol, which may 479 be bfd_link_hash_defined, bfd_link_hash_defweak, 480 bfd_link_hash_common, or bfd_link_hash_indirect. If OTYPE is 481 bfd_link_hash_common, OSIZE is the size of the existing symbol. 482 NBFD is the BFD of the new symbol. NTYPE is the type of the new 483 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or 484 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE 485 is the size of the new symbol. */ 486 bfd_boolean (*multiple_common) 487 (struct bfd_link_info *, const char *name, 488 bfd *obfd, enum bfd_link_hash_type otype, bfd_vma osize, 489 bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize); 490 /* A function which is called to add a symbol to a set. ENTRY is 491 the link hash table entry for the set itself (e.g., 492 __CTOR_LIST__). RELOC is the relocation to use for an entry in 493 the set when generating a relocatable file, and is also used to 494 get the size of the entry when generating an executable file. 495 ABFD, SEC and VALUE identify the value to add to the set. */ 496 bfd_boolean (*add_to_set) 497 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 498 bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value); 499 /* A function which is called when the name of a g++ constructor or 500 destructor is found. This is only called by some object file 501 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a 502 destructor. This will use BFD_RELOC_CTOR when generating a 503 relocatable file. NAME is the name of the symbol found. ABFD, 504 SECTION and VALUE are the value of the symbol. */ 505 bfd_boolean (*constructor) 506 (struct bfd_link_info *, bfd_boolean constructor, const char *name, 507 bfd *abfd, asection *sec, bfd_vma value); 508 /* A function which is called to issue a linker warning. For 509 example, this is called when there is a reference to a warning 510 symbol. WARNING is the warning to be issued. SYMBOL is the name 511 of the symbol which triggered the warning; it may be NULL if 512 there is none. ABFD, SECTION and ADDRESS identify the location 513 which trigerred the warning; either ABFD or SECTION or both may 514 be NULL if the location is not known. */ 515 bfd_boolean (*warning) 516 (struct bfd_link_info *, const char *warning, const char *symbol, 517 bfd *abfd, asection *section, bfd_vma address); 518 /* A function which is called when a relocation is attempted against 519 an undefined symbol. NAME is the symbol which is undefined. 520 ABFD, SECTION and ADDRESS identify the location from which the 521 reference is made. FATAL indicates whether an undefined symbol is 522 a fatal error or not. In some cases SECTION may be NULL. */ 523 bfd_boolean (*undefined_symbol) 524 (struct bfd_link_info *, const char *name, bfd *abfd, 525 asection *section, bfd_vma address, bfd_boolean fatal); 526 /* A function which is called when a reloc overflow occurs. ENTRY is 527 the link hash table entry for the symbol the reloc is against. 528 NAME is the name of the local symbol or section the reloc is 529 against, RELOC_NAME is the name of the relocation, and ADDEND is 530 any addend that is used. ABFD, SECTION and ADDRESS identify the 531 location at which the overflow occurs; if this is the result of a 532 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 533 ABFD will be NULL. */ 534 bfd_boolean (*reloc_overflow) 535 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 536 const char *name, const char *reloc_name, bfd_vma addend, 537 bfd *abfd, asection *section, bfd_vma address); 538 /* A function which is called when a dangerous reloc is performed. 539 MESSAGE is an appropriate message. 540 ABFD, SECTION and ADDRESS identify the location at which the 541 problem occurred; if this is the result of a 542 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 543 ABFD will be NULL. */ 544 bfd_boolean (*reloc_dangerous) 545 (struct bfd_link_info *, const char *message, 546 bfd *abfd, asection *section, bfd_vma address); 547 /* A function which is called when a reloc is found to be attached 548 to a symbol which is not being written out. NAME is the name of 549 the symbol. ABFD, SECTION and ADDRESS identify the location of 550 the reloc; if this is the result of a 551 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 552 ABFD will be NULL. */ 553 bfd_boolean (*unattached_reloc) 554 (struct bfd_link_info *, const char *name, 555 bfd *abfd, asection *section, bfd_vma address); 556 /* A function which is called when a symbol in notice_hash is 557 defined or referenced. NAME is the symbol. ABFD, SECTION and 558 ADDRESS are the value of the symbol. If SECTION is 559 bfd_und_section, this is a reference. */ 560 bfd_boolean (*notice) 561 (struct bfd_link_info *, const char *name, 562 bfd *abfd, asection *section, bfd_vma address); 563 /* General link info message. */ 564 void (*einfo) 565 (const char *fmt, ...); 566 }; 567 568 /* The linker builds link_order structures which tell the code how to 569 include input data in the output file. */ 570 571 /* These are the types of link_order structures. */ 572 573 enum bfd_link_order_type 574 { 575 bfd_undefined_link_order, /* Undefined. */ 576 bfd_indirect_link_order, /* Built from a section. */ 577 bfd_data_link_order, /* Set to explicit data. */ 578 bfd_section_reloc_link_order, /* Relocate against a section. */ 579 bfd_symbol_reloc_link_order /* Relocate against a symbol. */ 580 }; 581 582 /* This is the link_order structure itself. These form a chain 583 attached to the output section whose contents they are describing. */ 584 585 struct bfd_link_order 586 { 587 /* Next link_order in chain. */ 588 struct bfd_link_order *next; 589 /* Type of link_order. */ 590 enum bfd_link_order_type type; 591 /* Offset within output section. */ 592 bfd_vma offset; 593 /* Size within output section. */ 594 bfd_size_type size; 595 /* Type specific information. */ 596 union 597 { 598 struct 599 { 600 /* Section to include. If this is used, then 601 section->output_section must be the section the 602 link_order is attached to, section->output_offset must 603 equal the link_order offset field, and section->size 604 must equal the link_order size field. Maybe these 605 restrictions should be relaxed someday. */ 606 asection *section; 607 } indirect; 608 struct 609 { 610 /* Size of contents, or zero when contents size == size 611 within output section. 612 A non-zero value allows filling of the output section 613 with an arbitrary repeated pattern. */ 614 unsigned int size; 615 /* Data to put into file. */ 616 bfd_byte *contents; 617 } data; 618 struct 619 { 620 /* Description of reloc to generate. Used for 621 bfd_section_reloc_link_order and 622 bfd_symbol_reloc_link_order. */ 623 struct bfd_link_order_reloc *p; 624 } reloc; 625 } u; 626 }; 627 628 /* A linker order of type bfd_section_reloc_link_order or 629 bfd_symbol_reloc_link_order means to create a reloc against a 630 section or symbol, respectively. This is used to implement -Ur to 631 generate relocs for the constructor tables. The 632 bfd_link_order_reloc structure describes the reloc that BFD should 633 create. It is similar to a arelent, but I didn't use arelent 634 because the linker does not know anything about most symbols, and 635 any asymbol structure it creates will be partially meaningless. 636 This information could logically be in the bfd_link_order struct, 637 but I didn't want to waste the space since these types of relocs 638 are relatively rare. */ 639 640 struct bfd_link_order_reloc 641 { 642 /* Reloc type. */ 643 bfd_reloc_code_real_type reloc; 644 645 union 646 { 647 /* For type bfd_section_reloc_link_order, this is the section 648 the reloc should be against. This must be a section in the 649 output BFD, not any of the input BFDs. */ 650 asection *section; 651 /* For type bfd_symbol_reloc_link_order, this is the name of the 652 symbol the reloc should be against. */ 653 const char *name; 654 } u; 655 656 /* Addend to use. The object file should contain zero. The BFD 657 backend is responsible for filling in the contents of the object 658 file correctly. For some object file formats (e.g., COFF) the 659 addend must be stored into in the object file, and for some 660 (e.g., SPARC a.out) it is kept in the reloc. */ 661 bfd_vma addend; 662 }; 663 664 /* Allocate a new link_order for a section. */ 665 extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *); 666 667 /* These structures are used to describe version information for the 668 ELF linker. These structures could be manipulated entirely inside 669 BFD, but it would be a pain. Instead, the regular linker sets up 670 these structures, and then passes them into BFD. */ 671 672 /* Glob pattern for a version. */ 673 674 struct bfd_elf_version_expr 675 { 676 /* Next glob pattern for this version. */ 677 struct bfd_elf_version_expr *next; 678 /* Glob pattern. */ 679 const char *pattern; 680 /* NULL for a glob pattern, otherwise a straight symbol. */ 681 const char *symbol; 682 /* Defined by ".symver". */ 683 unsigned int symver : 1; 684 /* Defined by version script. */ 685 unsigned int script : 1; 686 /* Pattern type. */ 687 #define BFD_ELF_VERSION_C_TYPE 1 688 #define BFD_ELF_VERSION_CXX_TYPE 2 689 #define BFD_ELF_VERSION_JAVA_TYPE 4 690 unsigned int mask : 3; 691 }; 692 693 struct bfd_elf_version_expr_head 694 { 695 /* List of all patterns, both wildcards and non-wildcards. */ 696 struct bfd_elf_version_expr *list; 697 /* Hash table for non-wildcards. */ 698 void *htab; 699 /* Remaining patterns. */ 700 struct bfd_elf_version_expr *remaining; 701 /* What kind of pattern types are present in list (bitmask). */ 702 unsigned int mask; 703 }; 704 705 /* Version dependencies. */ 706 707 struct bfd_elf_version_deps 708 { 709 /* Next dependency for this version. */ 710 struct bfd_elf_version_deps *next; 711 /* The version which this version depends upon. */ 712 struct bfd_elf_version_tree *version_needed; 713 }; 714 715 /* A node in the version tree. */ 716 717 struct bfd_elf_version_tree 718 { 719 /* Next version. */ 720 struct bfd_elf_version_tree *next; 721 /* Name of this version. */ 722 const char *name; 723 /* Version number. */ 724 unsigned int vernum; 725 /* Regular expressions for global symbols in this version. */ 726 struct bfd_elf_version_expr_head globals; 727 /* Regular expressions for local symbols in this version. */ 728 struct bfd_elf_version_expr_head locals; 729 /* List of versions which this version depends upon. */ 730 struct bfd_elf_version_deps *deps; 731 /* Index of the version name. This is used within BFD. */ 732 unsigned int name_indx; 733 /* Whether this version tree was used. This is used within BFD. */ 734 int used; 735 /* Matching hook. */ 736 struct bfd_elf_version_expr *(*match) 737 (struct bfd_elf_version_expr_head *head, 738 struct bfd_elf_version_expr *prev, const char *sym); 739 }; 740 741 #endif 742