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 wxneeded: 1; 269 270 /* TRUE if ok to have version with no definition. */ 271 unsigned int allow_undefined_version: 1; 272 273 /* TRUE if a default symbol version should be created and used for 274 exported symbols. */ 275 unsigned int create_default_symver: 1; 276 277 /* TRUE if a default symbol version should be created and used for 278 imported symbols. */ 279 unsigned int default_imported_symver: 1; 280 281 /* TRUE if symbols should be retained in memory, FALSE if they 282 should be freed and reread. */ 283 unsigned int keep_memory: 1; 284 285 /* TRUE if every symbol should be reported back via the notice 286 callback. */ 287 unsigned int notice_all: 1; 288 289 /* TRUE if executable should not contain copy relocs. 290 Setting this true may result in a non-sharable text segment. */ 291 unsigned int nocopyreloc: 1; 292 293 /* TRUE if the new ELF dynamic tags are enabled. */ 294 unsigned int new_dtags: 1; 295 296 /* TRUE if non-PLT relocs should be merged into one reloc section 297 and sorted so that relocs against the same symbol come together. */ 298 unsigned int combreloc: 1; 299 300 /* TRUE if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment 301 should be created. */ 302 unsigned int eh_frame_hdr: 1; 303 304 /* TRUE if global symbols in discarded sections should be stripped. */ 305 unsigned int strip_discarded: 1; 306 307 /* TRUE if generating a position independent executable. */ 308 unsigned int pie: 1; 309 310 /* TRUE if generating an executable, position independent or not. */ 311 unsigned int executable : 1; 312 313 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X 314 flags. */ 315 unsigned int execstack: 1; 316 317 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W 318 flags. */ 319 unsigned int noexecstack: 1; 320 321 /* TRUE if PT_GNU_RELRO segment should be created. */ 322 unsigned int relro: 1; 323 324 /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */ 325 unsigned int warn_shared_textrel: 1; 326 327 /* TRUE if unreferenced sections should be removed. */ 328 unsigned int gc_sections: 1; 329 330 /* If TRUE reduce memory overheads, at the expense of speed. This will 331 cause map file generation to use an O(N^2) algorithm and disable 332 caching ELF symbol buffer. */ 333 unsigned int reduce_memory_overheads: 1; 334 335 /* What to do with unresolved symbols in an object file. 336 When producing executables the default is GENERATE_ERROR. 337 When producing shared libraries the default is IGNORE. The 338 assumption with shared libraries is that the reference will be 339 resolved at load/execution time. */ 340 enum report_method unresolved_syms_in_objects; 341 342 /* What to do with unresolved symbols in a shared library. 343 The same defaults apply. */ 344 enum report_method unresolved_syms_in_shared_libs; 345 346 /* Which symbols to strip. */ 347 enum bfd_link_strip strip; 348 349 /* Which local symbols to discard. */ 350 enum bfd_link_discard discard; 351 352 /* Criteria for skipping symbols when detemining 353 whether to include an object from an archive. */ 354 enum bfd_link_common_skip_ar_aymbols common_skip_ar_aymbols; 355 356 /* Char that may appear as the first char of a symbol, but should be 357 skipped (like symbol_leading_char) when looking up symbols in 358 wrap_hash. Used by PowerPC Linux for 'dot' symbols. */ 359 char wrap_char; 360 361 /* Function callbacks. */ 362 const struct bfd_link_callbacks *callbacks; 363 364 /* Hash table handled by BFD. */ 365 struct bfd_link_hash_table *hash; 366 367 /* Hash table of symbols to keep. This is NULL unless strip is 368 strip_some. */ 369 struct bfd_hash_table *keep_hash; 370 371 /* Hash table of symbols to report back via the notice callback. If 372 this is NULL, and notice_all is FALSE, then no symbols are 373 reported back. */ 374 struct bfd_hash_table *notice_hash; 375 376 /* Hash table of symbols which are being wrapped (the --wrap linker 377 option). If this is NULL, no symbols are being wrapped. */ 378 struct bfd_hash_table *wrap_hash; 379 380 /* The list of input BFD's involved in the link. These are chained 381 together via the link_next field. */ 382 bfd *input_bfds; 383 384 /* If a symbol should be created for each input BFD, this is section 385 where those symbols should be placed. It must be a section in 386 the output BFD. It may be NULL, in which case no such symbols 387 will be created. This is to support CREATE_OBJECT_SYMBOLS in the 388 linker command language. */ 389 asection *create_object_symbols_section; 390 391 /* List of global symbol names that are starting points for marking 392 sections against garbage collection. */ 393 struct bfd_sym_chain *gc_sym_list; 394 395 /* If a base output file is wanted, then this points to it */ 396 void *base_file; 397 398 /* The function to call when the executable or shared object is 399 loaded. */ 400 const char *init_function; 401 402 /* The function to call when the executable or shared object is 403 unloaded. */ 404 const char *fini_function; 405 406 /* Number of relaxation passes. Usually only one relaxation pass 407 is needed. But a backend can have as many relaxation passes as 408 necessary. During bfd_relax_section call, it is set to the 409 current pass, starting from 0. */ 410 int relax_pass; 411 412 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs 413 should be generated/linked against. Set to 1 if this feature 414 is explicitly requested by the user, -1 if enabled by default. */ 415 int pei386_auto_import; 416 417 /* Non-zero if runtime relocs for DATA items with non-zero addends 418 in pei386 DLLs should be generated. Set to 1 if this feature 419 is explicitly requested by the user, -1 if enabled by default. */ 420 int pei386_runtime_pseudo_reloc; 421 422 /* How many spare .dynamic DT_NULL entries should be added? */ 423 unsigned int spare_dynamic_tags; 424 425 /* May be used to set DT_FLAGS for ELF. */ 426 bfd_vma flags; 427 428 /* May be used to set DT_FLAGS_1 for ELF. */ 429 bfd_vma flags_1; 430 431 /* Start and end of RELRO region. */ 432 bfd_vma relro_start, relro_end; 433 }; 434 435 /* This structures holds a set of callback functions. These are 436 called by the BFD linker routines. Except for einfo, the first 437 argument to each callback function is the bfd_link_info structure 438 being used and each function returns a boolean value. If the 439 function returns FALSE, then the BFD function which called it should 440 return with a failure indication. */ 441 442 struct bfd_link_callbacks 443 { 444 /* A function which is called when an object is added from an 445 archive. ABFD is the archive element being added. NAME is the 446 name of the symbol which caused the archive element to be pulled 447 in. */ 448 bfd_boolean (*add_archive_element) 449 (struct bfd_link_info *, bfd *abfd, const char *name); 450 /* A function which is called when a symbol is found with multiple 451 definitions. NAME is the symbol which is defined multiple times. 452 OBFD is the old BFD, OSEC is the old section, OVAL is the old 453 value, NBFD is the new BFD, NSEC is the new section, and NVAL is 454 the new value. OBFD may be NULL. OSEC and NSEC may be 455 bfd_com_section or bfd_ind_section. */ 456 bfd_boolean (*multiple_definition) 457 (struct bfd_link_info *, const char *name, 458 bfd *obfd, asection *osec, bfd_vma oval, 459 bfd *nbfd, asection *nsec, bfd_vma nval); 460 /* A function which is called when a common symbol is defined 461 multiple times. NAME is the symbol appearing multiple times. 462 OBFD is the BFD of the existing symbol; it may be NULL if this is 463 not known. OTYPE is the type of the existing symbol, which may 464 be bfd_link_hash_defined, bfd_link_hash_defweak, 465 bfd_link_hash_common, or bfd_link_hash_indirect. If OTYPE is 466 bfd_link_hash_common, OSIZE is the size of the existing symbol. 467 NBFD is the BFD of the new symbol. NTYPE is the type of the new 468 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or 469 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE 470 is the size of the new symbol. */ 471 bfd_boolean (*multiple_common) 472 (struct bfd_link_info *, const char *name, 473 bfd *obfd, enum bfd_link_hash_type otype, bfd_vma osize, 474 bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize); 475 /* A function which is called to add a symbol to a set. ENTRY is 476 the link hash table entry for the set itself (e.g., 477 __CTOR_LIST__). RELOC is the relocation to use for an entry in 478 the set when generating a relocatable file, and is also used to 479 get the size of the entry when generating an executable file. 480 ABFD, SEC and VALUE identify the value to add to the set. */ 481 bfd_boolean (*add_to_set) 482 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 483 bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value); 484 /* A function which is called when the name of a g++ constructor or 485 destructor is found. This is only called by some object file 486 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a 487 destructor. This will use BFD_RELOC_CTOR when generating a 488 relocatable file. NAME is the name of the symbol found. ABFD, 489 SECTION and VALUE are the value of the symbol. */ 490 bfd_boolean (*constructor) 491 (struct bfd_link_info *, bfd_boolean constructor, const char *name, 492 bfd *abfd, asection *sec, bfd_vma value); 493 /* A function which is called to issue a linker warning. For 494 example, this is called when there is a reference to a warning 495 symbol. WARNING is the warning to be issued. SYMBOL is the name 496 of the symbol which triggered the warning; it may be NULL if 497 there is none. ABFD, SECTION and ADDRESS identify the location 498 which trigerred the warning; either ABFD or SECTION or both may 499 be NULL if the location is not known. */ 500 bfd_boolean (*warning) 501 (struct bfd_link_info *, const char *warning, const char *symbol, 502 bfd *abfd, asection *section, bfd_vma address); 503 /* A function which is called when a relocation is attempted against 504 an undefined symbol. NAME is the symbol which is undefined. 505 ABFD, SECTION and ADDRESS identify the location from which the 506 reference is made. FATAL indicates whether an undefined symbol is 507 a fatal error or not. In some cases SECTION may be NULL. */ 508 bfd_boolean (*undefined_symbol) 509 (struct bfd_link_info *, const char *name, bfd *abfd, 510 asection *section, bfd_vma address, bfd_boolean fatal); 511 /* A function which is called when a reloc overflow occurs. ENTRY is 512 the link hash table entry for the symbol the reloc is against. 513 NAME is the name of the local symbol or section the reloc is 514 against, RELOC_NAME is the name of the relocation, and ADDEND is 515 any addend that is used. ABFD, SECTION and ADDRESS identify the 516 location at which the overflow occurs; if this is the result of a 517 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 518 ABFD will be NULL. */ 519 bfd_boolean (*reloc_overflow) 520 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 521 const char *name, const char *reloc_name, bfd_vma addend, 522 bfd *abfd, asection *section, bfd_vma address); 523 /* A function which is called when a dangerous reloc is performed. 524 MESSAGE is an appropriate message. 525 ABFD, SECTION and ADDRESS identify the location at which the 526 problem occurred; if this is the result of a 527 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 528 ABFD will be NULL. */ 529 bfd_boolean (*reloc_dangerous) 530 (struct bfd_link_info *, const char *message, 531 bfd *abfd, asection *section, bfd_vma address); 532 /* A function which is called when a reloc is found to be attached 533 to a symbol which is not being written out. NAME is the name of 534 the symbol. ABFD, SECTION and ADDRESS identify the location of 535 the reloc; if this is the result of a 536 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 537 ABFD will be NULL. */ 538 bfd_boolean (*unattached_reloc) 539 (struct bfd_link_info *, const char *name, 540 bfd *abfd, asection *section, bfd_vma address); 541 /* A function which is called when a symbol in notice_hash is 542 defined or referenced. NAME is the symbol. ABFD, SECTION and 543 ADDRESS are the value of the symbol. If SECTION is 544 bfd_und_section, this is a reference. */ 545 bfd_boolean (*notice) 546 (struct bfd_link_info *, const char *name, 547 bfd *abfd, asection *section, bfd_vma address); 548 /* General link info message. */ 549 void (*einfo) 550 (const char *fmt, ...); 551 }; 552 553 /* The linker builds link_order structures which tell the code how to 554 include input data in the output file. */ 555 556 /* These are the types of link_order structures. */ 557 558 enum bfd_link_order_type 559 { 560 bfd_undefined_link_order, /* Undefined. */ 561 bfd_indirect_link_order, /* Built from a section. */ 562 bfd_data_link_order, /* Set to explicit data. */ 563 bfd_section_reloc_link_order, /* Relocate against a section. */ 564 bfd_symbol_reloc_link_order /* Relocate against a symbol. */ 565 }; 566 567 /* This is the link_order structure itself. These form a chain 568 attached to the output section whose contents they are describing. */ 569 570 struct bfd_link_order 571 { 572 /* Next link_order in chain. */ 573 struct bfd_link_order *next; 574 /* Type of link_order. */ 575 enum bfd_link_order_type type; 576 /* Offset within output section. */ 577 bfd_vma offset; 578 /* Size within output section. */ 579 bfd_size_type size; 580 /* Type specific information. */ 581 union 582 { 583 struct 584 { 585 /* Section to include. If this is used, then 586 section->output_section must be the section the 587 link_order is attached to, section->output_offset must 588 equal the link_order offset field, and section->size 589 must equal the link_order size field. Maybe these 590 restrictions should be relaxed someday. */ 591 asection *section; 592 } indirect; 593 struct 594 { 595 /* Size of contents, or zero when contents size == size 596 within output section. 597 A non-zero value allows filling of the output section 598 with an arbitrary repeated pattern. */ 599 unsigned int size; 600 /* Data to put into file. */ 601 bfd_byte *contents; 602 } data; 603 struct 604 { 605 /* Description of reloc to generate. Used for 606 bfd_section_reloc_link_order and 607 bfd_symbol_reloc_link_order. */ 608 struct bfd_link_order_reloc *p; 609 } reloc; 610 } u; 611 }; 612 613 /* A linker order of type bfd_section_reloc_link_order or 614 bfd_symbol_reloc_link_order means to create a reloc against a 615 section or symbol, respectively. This is used to implement -Ur to 616 generate relocs for the constructor tables. The 617 bfd_link_order_reloc structure describes the reloc that BFD should 618 create. It is similar to a arelent, but I didn't use arelent 619 because the linker does not know anything about most symbols, and 620 any asymbol structure it creates will be partially meaningless. 621 This information could logically be in the bfd_link_order struct, 622 but I didn't want to waste the space since these types of relocs 623 are relatively rare. */ 624 625 struct bfd_link_order_reloc 626 { 627 /* Reloc type. */ 628 bfd_reloc_code_real_type reloc; 629 630 union 631 { 632 /* For type bfd_section_reloc_link_order, this is the section 633 the reloc should be against. This must be a section in the 634 output BFD, not any of the input BFDs. */ 635 asection *section; 636 /* For type bfd_symbol_reloc_link_order, this is the name of the 637 symbol the reloc should be against. */ 638 const char *name; 639 } u; 640 641 /* Addend to use. The object file should contain zero. The BFD 642 backend is responsible for filling in the contents of the object 643 file correctly. For some object file formats (e.g., COFF) the 644 addend must be stored into in the object file, and for some 645 (e.g., SPARC a.out) it is kept in the reloc. */ 646 bfd_vma addend; 647 }; 648 649 /* Allocate a new link_order for a section. */ 650 extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *); 651 652 /* These structures are used to describe version information for the 653 ELF linker. These structures could be manipulated entirely inside 654 BFD, but it would be a pain. Instead, the regular linker sets up 655 these structures, and then passes them into BFD. */ 656 657 /* Glob pattern for a version. */ 658 659 struct bfd_elf_version_expr 660 { 661 /* Next glob pattern for this version. */ 662 struct bfd_elf_version_expr *next; 663 /* Glob pattern. */ 664 const char *pattern; 665 /* NULL for a glob pattern, otherwise a straight symbol. */ 666 const char *symbol; 667 /* Defined by ".symver". */ 668 unsigned int symver : 1; 669 /* Defined by version script. */ 670 unsigned int script : 1; 671 /* Pattern type. */ 672 #define BFD_ELF_VERSION_C_TYPE 1 673 #define BFD_ELF_VERSION_CXX_TYPE 2 674 #define BFD_ELF_VERSION_JAVA_TYPE 4 675 unsigned int mask : 3; 676 }; 677 678 struct bfd_elf_version_expr_head 679 { 680 /* List of all patterns, both wildcards and non-wildcards. */ 681 struct bfd_elf_version_expr *list; 682 /* Hash table for non-wildcards. */ 683 void *htab; 684 /* Remaining patterns. */ 685 struct bfd_elf_version_expr *remaining; 686 /* What kind of pattern types are present in list (bitmask). */ 687 unsigned int mask; 688 }; 689 690 /* Version dependencies. */ 691 692 struct bfd_elf_version_deps 693 { 694 /* Next dependency for this version. */ 695 struct bfd_elf_version_deps *next; 696 /* The version which this version depends upon. */ 697 struct bfd_elf_version_tree *version_needed; 698 }; 699 700 /* A node in the version tree. */ 701 702 struct bfd_elf_version_tree 703 { 704 /* Next version. */ 705 struct bfd_elf_version_tree *next; 706 /* Name of this version. */ 707 const char *name; 708 /* Version number. */ 709 unsigned int vernum; 710 /* Regular expressions for global symbols in this version. */ 711 struct bfd_elf_version_expr_head globals; 712 /* Regular expressions for local symbols in this version. */ 713 struct bfd_elf_version_expr_head locals; 714 /* List of versions which this version depends upon. */ 715 struct bfd_elf_version_deps *deps; 716 /* Index of the version name. This is used within BFD. */ 717 unsigned int name_indx; 718 /* Whether this version tree was used. This is used within BFD. */ 719 int used; 720 /* Matching hook. */ 721 struct bfd_elf_version_expr *(*match) 722 (struct bfd_elf_version_expr_head *head, 723 struct bfd_elf_version_expr *prev, const char *sym); 724 }; 725 726 #endif 727