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 ok to have text relocations. */ 274 unsigned int allow_textrel: 1; 275 276 /* TRUE if a default symbol version should be created and used for 277 exported symbols. */ 278 unsigned int create_default_symver: 1; 279 280 /* TRUE if a default symbol version should be created and used for 281 imported symbols. */ 282 unsigned int default_imported_symver: 1; 283 284 /* TRUE if symbols should be retained in memory, FALSE if they 285 should be freed and reread. */ 286 unsigned int keep_memory: 1; 287 288 /* TRUE if every symbol should be reported back via the notice 289 callback. */ 290 unsigned int notice_all: 1; 291 292 /* TRUE if executable should not contain copy relocs. 293 Setting this true may result in a non-sharable text segment. */ 294 unsigned int nocopyreloc: 1; 295 296 /* TRUE if the new ELF dynamic tags are enabled. */ 297 unsigned int new_dtags: 1; 298 299 /* TRUE if non-PLT relocs should be merged into one reloc section 300 and sorted so that relocs against the same symbol come together. */ 301 unsigned int combreloc: 1; 302 303 /* TRUE if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment 304 should be created. */ 305 unsigned int eh_frame_hdr: 1; 306 307 /* TRUE if global symbols in discarded sections should be stripped. */ 308 unsigned int strip_discarded: 1; 309 310 /* TRUE if generating a position independent executable. */ 311 unsigned int pie: 1; 312 313 /* TRUE if generating an executable, position independent or not. */ 314 unsigned int executable : 1; 315 316 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X 317 flags. */ 318 unsigned int execstack: 1; 319 320 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W 321 flags. */ 322 unsigned int noexecstack: 1; 323 324 /* TRUE if PT_GNU_RELRO segment should be created. */ 325 unsigned int relro: 1; 326 327 /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */ 328 unsigned int warn_shared_textrel: 1; 329 330 /* TRUE if unreferenced sections should be removed. */ 331 unsigned int gc_sections: 1; 332 333 /* If TRUE reduce memory overheads, at the expense of speed. This will 334 cause map file generation to use an O(N^2) algorithm and disable 335 caching ELF symbol buffer. */ 336 unsigned int reduce_memory_overheads: 1; 337 338 /* What to do with unresolved symbols in an object file. 339 When producing executables the default is GENERATE_ERROR. 340 When producing shared libraries the default is IGNORE. The 341 assumption with shared libraries is that the reference will be 342 resolved at load/execution time. */ 343 enum report_method unresolved_syms_in_objects; 344 345 /* What to do with unresolved symbols in a shared library. 346 The same defaults apply. */ 347 enum report_method unresolved_syms_in_shared_libs; 348 349 /* Which symbols to strip. */ 350 enum bfd_link_strip strip; 351 352 /* Which local symbols to discard. */ 353 enum bfd_link_discard discard; 354 355 /* Criteria for skipping symbols when detemining 356 whether to include an object from an archive. */ 357 enum bfd_link_common_skip_ar_aymbols common_skip_ar_aymbols; 358 359 /* Char that may appear as the first char of a symbol, but should be 360 skipped (like symbol_leading_char) when looking up symbols in 361 wrap_hash. Used by PowerPC Linux for 'dot' symbols. */ 362 char wrap_char; 363 364 /* Function callbacks. */ 365 const struct bfd_link_callbacks *callbacks; 366 367 /* Hash table handled by BFD. */ 368 struct bfd_link_hash_table *hash; 369 370 /* Hash table of symbols to keep. This is NULL unless strip is 371 strip_some. */ 372 struct bfd_hash_table *keep_hash; 373 374 /* Hash table of symbols to report back via the notice callback. If 375 this is NULL, and notice_all is FALSE, then no symbols are 376 reported back. */ 377 struct bfd_hash_table *notice_hash; 378 379 /* Hash table of symbols which are being wrapped (the --wrap linker 380 option). If this is NULL, no symbols are being wrapped. */ 381 struct bfd_hash_table *wrap_hash; 382 383 /* The list of input BFD's involved in the link. These are chained 384 together via the link_next field. */ 385 bfd *input_bfds; 386 387 /* If a symbol should be created for each input BFD, this is section 388 where those symbols should be placed. It must be a section in 389 the output BFD. It may be NULL, in which case no such symbols 390 will be created. This is to support CREATE_OBJECT_SYMBOLS in the 391 linker command language. */ 392 asection *create_object_symbols_section; 393 394 /* List of global symbol names that are starting points for marking 395 sections against garbage collection. */ 396 struct bfd_sym_chain *gc_sym_list; 397 398 /* If a base output file is wanted, then this points to it */ 399 void *base_file; 400 401 /* The function to call when the executable or shared object is 402 loaded. */ 403 const char *init_function; 404 405 /* The function to call when the executable or shared object is 406 unloaded. */ 407 const char *fini_function; 408 409 /* Number of relaxation passes. Usually only one relaxation pass 410 is needed. But a backend can have as many relaxation passes as 411 necessary. During bfd_relax_section call, it is set to the 412 current pass, starting from 0. */ 413 int relax_pass; 414 415 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs 416 should be generated/linked against. Set to 1 if this feature 417 is explicitly requested by the user, -1 if enabled by default. */ 418 int pei386_auto_import; 419 420 /* Non-zero if runtime relocs for DATA items with non-zero addends 421 in pei386 DLLs should be generated. Set to 1 if this feature 422 is explicitly requested by the user, -1 if enabled by default. */ 423 int pei386_runtime_pseudo_reloc; 424 425 /* How many spare .dynamic DT_NULL entries should be added? */ 426 unsigned int spare_dynamic_tags; 427 428 /* May be used to set DT_FLAGS for ELF. */ 429 bfd_vma flags; 430 431 /* May be used to set DT_FLAGS_1 for ELF. */ 432 bfd_vma flags_1; 433 434 /* Start and end of RELRO region. */ 435 bfd_vma relro_start, relro_end; 436 }; 437 438 /* This structures holds a set of callback functions. These are 439 called by the BFD linker routines. Except for einfo, the first 440 argument to each callback function is the bfd_link_info structure 441 being used and each function returns a boolean value. If the 442 function returns FALSE, then the BFD function which called it should 443 return with a failure indication. */ 444 445 struct bfd_link_callbacks 446 { 447 /* A function which is called when an object is added from an 448 archive. ABFD is the archive element being added. NAME is the 449 name of the symbol which caused the archive element to be pulled 450 in. */ 451 bfd_boolean (*add_archive_element) 452 (struct bfd_link_info *, bfd *abfd, const char *name); 453 /* A function which is called when a symbol is found with multiple 454 definitions. NAME is the symbol which is defined multiple times. 455 OBFD is the old BFD, OSEC is the old section, OVAL is the old 456 value, NBFD is the new BFD, NSEC is the new section, and NVAL is 457 the new value. OBFD may be NULL. OSEC and NSEC may be 458 bfd_com_section or bfd_ind_section. */ 459 bfd_boolean (*multiple_definition) 460 (struct bfd_link_info *, const char *name, 461 bfd *obfd, asection *osec, bfd_vma oval, 462 bfd *nbfd, asection *nsec, bfd_vma nval); 463 /* A function which is called when a common symbol is defined 464 multiple times. NAME is the symbol appearing multiple times. 465 OBFD is the BFD of the existing symbol; it may be NULL if this is 466 not known. OTYPE is the type of the existing symbol, which may 467 be bfd_link_hash_defined, bfd_link_hash_defweak, 468 bfd_link_hash_common, or bfd_link_hash_indirect. If OTYPE is 469 bfd_link_hash_common, OSIZE is the size of the existing symbol. 470 NBFD is the BFD of the new symbol. NTYPE is the type of the new 471 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or 472 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE 473 is the size of the new symbol. */ 474 bfd_boolean (*multiple_common) 475 (struct bfd_link_info *, const char *name, 476 bfd *obfd, enum bfd_link_hash_type otype, bfd_vma osize, 477 bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize); 478 /* A function which is called to add a symbol to a set. ENTRY is 479 the link hash table entry for the set itself (e.g., 480 __CTOR_LIST__). RELOC is the relocation to use for an entry in 481 the set when generating a relocatable file, and is also used to 482 get the size of the entry when generating an executable file. 483 ABFD, SEC and VALUE identify the value to add to the set. */ 484 bfd_boolean (*add_to_set) 485 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 486 bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value); 487 /* A function which is called when the name of a g++ constructor or 488 destructor is found. This is only called by some object file 489 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a 490 destructor. This will use BFD_RELOC_CTOR when generating a 491 relocatable file. NAME is the name of the symbol found. ABFD, 492 SECTION and VALUE are the value of the symbol. */ 493 bfd_boolean (*constructor) 494 (struct bfd_link_info *, bfd_boolean constructor, const char *name, 495 bfd *abfd, asection *sec, bfd_vma value); 496 /* A function which is called to issue a linker warning. For 497 example, this is called when there is a reference to a warning 498 symbol. WARNING is the warning to be issued. SYMBOL is the name 499 of the symbol which triggered the warning; it may be NULL if 500 there is none. ABFD, SECTION and ADDRESS identify the location 501 which trigerred the warning; either ABFD or SECTION or both may 502 be NULL if the location is not known. */ 503 bfd_boolean (*warning) 504 (struct bfd_link_info *, const char *warning, const char *symbol, 505 bfd *abfd, asection *section, bfd_vma address); 506 /* A function which is called when a relocation is attempted against 507 an undefined symbol. NAME is the symbol which is undefined. 508 ABFD, SECTION and ADDRESS identify the location from which the 509 reference is made. FATAL indicates whether an undefined symbol is 510 a fatal error or not. In some cases SECTION may be NULL. */ 511 bfd_boolean (*undefined_symbol) 512 (struct bfd_link_info *, const char *name, bfd *abfd, 513 asection *section, bfd_vma address, bfd_boolean fatal); 514 /* A function which is called when a reloc overflow occurs. ENTRY is 515 the link hash table entry for the symbol the reloc is against. 516 NAME is the name of the local symbol or section the reloc is 517 against, RELOC_NAME is the name of the relocation, and ADDEND is 518 any addend that is used. ABFD, SECTION and ADDRESS identify the 519 location at which the overflow occurs; if this is the result of a 520 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 521 ABFD will be NULL. */ 522 bfd_boolean (*reloc_overflow) 523 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 524 const char *name, const char *reloc_name, bfd_vma addend, 525 bfd *abfd, asection *section, bfd_vma address); 526 /* A function which is called when a dangerous reloc is performed. 527 MESSAGE is an appropriate message. 528 ABFD, SECTION and ADDRESS identify the location at which the 529 problem occurred; if this is the result of a 530 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 531 ABFD will be NULL. */ 532 bfd_boolean (*reloc_dangerous) 533 (struct bfd_link_info *, const char *message, 534 bfd *abfd, asection *section, bfd_vma address); 535 /* A function which is called when a reloc is found to be attached 536 to a symbol which is not being written out. NAME is the name of 537 the symbol. ABFD, SECTION and ADDRESS identify the location of 538 the reloc; if this is the result of a 539 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 540 ABFD will be NULL. */ 541 bfd_boolean (*unattached_reloc) 542 (struct bfd_link_info *, const char *name, 543 bfd *abfd, asection *section, bfd_vma address); 544 /* A function which is called when a symbol in notice_hash is 545 defined or referenced. NAME is the symbol. ABFD, SECTION and 546 ADDRESS are the value of the symbol. If SECTION is 547 bfd_und_section, this is a reference. */ 548 bfd_boolean (*notice) 549 (struct bfd_link_info *, const char *name, 550 bfd *abfd, asection *section, bfd_vma address); 551 /* General link info message. */ 552 void (*einfo) 553 (const char *fmt, ...); 554 }; 555 556 /* The linker builds link_order structures which tell the code how to 557 include input data in the output file. */ 558 559 /* These are the types of link_order structures. */ 560 561 enum bfd_link_order_type 562 { 563 bfd_undefined_link_order, /* Undefined. */ 564 bfd_indirect_link_order, /* Built from a section. */ 565 bfd_data_link_order, /* Set to explicit data. */ 566 bfd_section_reloc_link_order, /* Relocate against a section. */ 567 bfd_symbol_reloc_link_order /* Relocate against a symbol. */ 568 }; 569 570 /* This is the link_order structure itself. These form a chain 571 attached to the output section whose contents they are describing. */ 572 573 struct bfd_link_order 574 { 575 /* Next link_order in chain. */ 576 struct bfd_link_order *next; 577 /* Type of link_order. */ 578 enum bfd_link_order_type type; 579 /* Offset within output section. */ 580 bfd_vma offset; 581 /* Size within output section. */ 582 bfd_size_type size; 583 /* Type specific information. */ 584 union 585 { 586 struct 587 { 588 /* Section to include. If this is used, then 589 section->output_section must be the section the 590 link_order is attached to, section->output_offset must 591 equal the link_order offset field, and section->size 592 must equal the link_order size field. Maybe these 593 restrictions should be relaxed someday. */ 594 asection *section; 595 } indirect; 596 struct 597 { 598 /* Size of contents, or zero when contents size == size 599 within output section. 600 A non-zero value allows filling of the output section 601 with an arbitrary repeated pattern. */ 602 unsigned int size; 603 /* Data to put into file. */ 604 bfd_byte *contents; 605 } data; 606 struct 607 { 608 /* Description of reloc to generate. Used for 609 bfd_section_reloc_link_order and 610 bfd_symbol_reloc_link_order. */ 611 struct bfd_link_order_reloc *p; 612 } reloc; 613 } u; 614 }; 615 616 /* A linker order of type bfd_section_reloc_link_order or 617 bfd_symbol_reloc_link_order means to create a reloc against a 618 section or symbol, respectively. This is used to implement -Ur to 619 generate relocs for the constructor tables. The 620 bfd_link_order_reloc structure describes the reloc that BFD should 621 create. It is similar to a arelent, but I didn't use arelent 622 because the linker does not know anything about most symbols, and 623 any asymbol structure it creates will be partially meaningless. 624 This information could logically be in the bfd_link_order struct, 625 but I didn't want to waste the space since these types of relocs 626 are relatively rare. */ 627 628 struct bfd_link_order_reloc 629 { 630 /* Reloc type. */ 631 bfd_reloc_code_real_type reloc; 632 633 union 634 { 635 /* For type bfd_section_reloc_link_order, this is the section 636 the reloc should be against. This must be a section in the 637 output BFD, not any of the input BFDs. */ 638 asection *section; 639 /* For type bfd_symbol_reloc_link_order, this is the name of the 640 symbol the reloc should be against. */ 641 const char *name; 642 } u; 643 644 /* Addend to use. The object file should contain zero. The BFD 645 backend is responsible for filling in the contents of the object 646 file correctly. For some object file formats (e.g., COFF) the 647 addend must be stored into in the object file, and for some 648 (e.g., SPARC a.out) it is kept in the reloc. */ 649 bfd_vma addend; 650 }; 651 652 /* Allocate a new link_order for a section. */ 653 extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *); 654 655 /* These structures are used to describe version information for the 656 ELF linker. These structures could be manipulated entirely inside 657 BFD, but it would be a pain. Instead, the regular linker sets up 658 these structures, and then passes them into BFD. */ 659 660 /* Glob pattern for a version. */ 661 662 struct bfd_elf_version_expr 663 { 664 /* Next glob pattern for this version. */ 665 struct bfd_elf_version_expr *next; 666 /* Glob pattern. */ 667 const char *pattern; 668 /* NULL for a glob pattern, otherwise a straight symbol. */ 669 const char *symbol; 670 /* Defined by ".symver". */ 671 unsigned int symver : 1; 672 /* Defined by version script. */ 673 unsigned int script : 1; 674 /* Pattern type. */ 675 #define BFD_ELF_VERSION_C_TYPE 1 676 #define BFD_ELF_VERSION_CXX_TYPE 2 677 #define BFD_ELF_VERSION_JAVA_TYPE 4 678 unsigned int mask : 3; 679 }; 680 681 struct bfd_elf_version_expr_head 682 { 683 /* List of all patterns, both wildcards and non-wildcards. */ 684 struct bfd_elf_version_expr *list; 685 /* Hash table for non-wildcards. */ 686 void *htab; 687 /* Remaining patterns. */ 688 struct bfd_elf_version_expr *remaining; 689 /* What kind of pattern types are present in list (bitmask). */ 690 unsigned int mask; 691 }; 692 693 /* Version dependencies. */ 694 695 struct bfd_elf_version_deps 696 { 697 /* Next dependency for this version. */ 698 struct bfd_elf_version_deps *next; 699 /* The version which this version depends upon. */ 700 struct bfd_elf_version_tree *version_needed; 701 }; 702 703 /* A node in the version tree. */ 704 705 struct bfd_elf_version_tree 706 { 707 /* Next version. */ 708 struct bfd_elf_version_tree *next; 709 /* Name of this version. */ 710 const char *name; 711 /* Version number. */ 712 unsigned int vernum; 713 /* Regular expressions for global symbols in this version. */ 714 struct bfd_elf_version_expr_head globals; 715 /* Regular expressions for local symbols in this version. */ 716 struct bfd_elf_version_expr_head locals; 717 /* List of versions which this version depends upon. */ 718 struct bfd_elf_version_deps *deps; 719 /* Index of the version name. This is used within BFD. */ 720 unsigned int name_indx; 721 /* Whether this version tree was used. This is used within BFD. */ 722 int used; 723 /* Matching hook. */ 724 struct bfd_elf_version_expr *(*match) 725 (struct bfd_elf_version_expr_head *head, 726 struct bfd_elf_version_expr *prev, const char *sym); 727 }; 728 729 #endif 730