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, 2006, 2007, 2008, 2009 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 3 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, 21 MA 02110-1301, USA. */ 22 23 #ifndef BFDLINK_H 24 #define BFDLINK_H 25 26 /* Which symbols to strip during a link. */ 27 enum bfd_link_strip 28 { 29 strip_none, /* Don't strip any symbols. */ 30 strip_debugger, /* Strip debugging symbols. */ 31 strip_some, /* keep_hash is the list of symbols to keep. */ 32 strip_all /* Strip all symbols. */ 33 }; 34 35 /* Which local symbols to discard during a link. This is irrelevant 36 if strip_all is used. */ 37 enum bfd_link_discard 38 { 39 discard_sec_merge, /* Discard local temporary symbols in SEC_MERGE 40 sections. */ 41 discard_none, /* Don't discard any locals. */ 42 discard_l, /* Discard local temporary symbols. */ 43 discard_all /* Discard all locals. */ 44 }; 45 46 /* Describes the type of hash table entry structure being used. 47 Different hash table structure have different fields and so 48 support different linking features. */ 49 enum bfd_link_hash_table_type 50 { 51 bfd_link_generic_hash_table, 52 bfd_link_elf_hash_table 53 }; 54 55 /* These are the possible types of an entry in the BFD link hash 57 table. */ 58 59 enum bfd_link_hash_type 60 { 61 bfd_link_hash_new, /* Symbol is new. */ 62 bfd_link_hash_undefined, /* Symbol seen before, but undefined. */ 63 bfd_link_hash_undefweak, /* Symbol is weak and undefined. */ 64 bfd_link_hash_defined, /* Symbol is defined. */ 65 bfd_link_hash_defweak, /* Symbol is weak and defined. */ 66 bfd_link_hash_common, /* Symbol is common. */ 67 bfd_link_hash_indirect, /* Symbol is an indirect link. */ 68 bfd_link_hash_warning /* Like indirect, but warn if referenced. */ 69 }; 70 71 enum bfd_link_common_skip_ar_aymbols 72 { 73 bfd_link_common_skip_none, 74 bfd_link_common_skip_text, 75 bfd_link_common_skip_data, 76 bfd_link_common_skip_all 77 }; 78 79 struct bfd_link_hash_common_entry 80 { 81 unsigned int alignment_power; /* Alignment. */ 82 asection *section; /* Symbol section. */ 83 }; 84 85 /* The linking routines use a hash table which uses this structure for 86 its elements. */ 87 88 struct bfd_link_hash_entry 89 { 90 /* Base hash table entry structure. */ 91 struct bfd_hash_entry root; 92 93 /* Type of this entry. */ 94 enum bfd_link_hash_type type; 95 96 /* A union of information depending upon the type. */ 97 union 98 { 99 /* Nothing is kept for bfd_hash_new. */ 100 /* bfd_link_hash_undefined, bfd_link_hash_undefweak. */ 101 struct 102 { 103 /* Undefined and common symbols are kept in a linked list through 104 this field. This field is present in all of the union element 105 so that we don't need to remove entries from the list when we 106 change their type. Removing entries would either require the 107 list to be doubly linked, which would waste more memory, or 108 require a traversal. When an undefined or common symbol is 109 created, it should be added to this list, the head of which is in 110 the link hash table itself. As symbols are defined, they need 111 not be removed from the list; anything which reads the list must 112 doublecheck the symbol type. 113 114 Weak symbols are not kept on this list. 115 116 Defined and defweak symbols use this field as a reference marker. 117 If the field is not NULL, or this structure is the tail of the 118 undefined symbol list, the symbol has been referenced. If the 119 symbol is undefined and becomes defined, this field will 120 automatically be non-NULL since the symbol will have been on the 121 undefined symbol list. */ 122 struct bfd_link_hash_entry *next; 123 bfd *abfd; /* BFD symbol was found in. */ 124 bfd *weak; /* BFD weak symbol was found in. */ 125 } undef; 126 /* bfd_link_hash_defined, bfd_link_hash_defweak. */ 127 struct 128 { 129 struct bfd_link_hash_entry *next; 130 asection *section; /* Symbol section. */ 131 bfd_vma value; /* Symbol value. */ 132 } def; 133 /* bfd_link_hash_indirect, bfd_link_hash_warning. */ 134 struct 135 { 136 struct bfd_link_hash_entry *next; 137 struct bfd_link_hash_entry *link; /* Real symbol. */ 138 const char *warning; /* Warning (bfd_link_hash_warning only). */ 139 } i; 140 /* bfd_link_hash_common. */ 141 struct 142 { 143 struct bfd_link_hash_entry *next; 144 /* The linker needs to know three things about common 145 symbols: the size, the alignment, and the section in 146 which the symbol should be placed. We store the size 147 here, and we allocate a small structure to hold the 148 section and the alignment. The alignment is stored as a 149 power of two. We don't store all the information 150 directly because we don't want to increase the size of 151 the union; this structure is a major space user in the 152 linker. */ 153 struct bfd_link_hash_common_entry *p; 154 bfd_size_type size; /* Common symbol size. */ 155 } c; 156 } u; 157 }; 158 159 /* This is the link hash table. It is a derived class of 160 bfd_hash_table. */ 161 162 struct bfd_link_hash_table 163 { 164 /* The hash table itself. */ 165 struct bfd_hash_table table; 166 /* A linked list of undefined and common symbols, linked through the 167 next field in the bfd_link_hash_entry structure. */ 168 struct bfd_link_hash_entry *undefs; 169 /* Entries are added to the tail of the undefs list. */ 170 struct bfd_link_hash_entry *undefs_tail; 171 /* The type of the link hash table. */ 172 enum bfd_link_hash_table_type type; 173 }; 174 175 /* Look up an entry in a link hash table. If FOLLOW is TRUE, this 176 follows bfd_link_hash_indirect and bfd_link_hash_warning links to 177 the real symbol. */ 178 extern struct bfd_link_hash_entry *bfd_link_hash_lookup 179 (struct bfd_link_hash_table *, const char *, bfd_boolean create, 180 bfd_boolean copy, bfd_boolean follow); 181 182 /* Look up an entry in the main linker hash table if the symbol might 183 be wrapped. This should only be used for references to an 184 undefined symbol, not for definitions of a symbol. */ 185 186 extern struct bfd_link_hash_entry *bfd_wrapped_link_hash_lookup 187 (bfd *, struct bfd_link_info *, const char *, bfd_boolean, 188 bfd_boolean, bfd_boolean); 189 190 /* Traverse a link hash table. */ 191 extern void bfd_link_hash_traverse 192 (struct bfd_link_hash_table *, 193 bfd_boolean (*) (struct bfd_link_hash_entry *, void *), 194 void *); 195 196 /* Add an entry to the undefs list. */ 197 extern void bfd_link_add_undef 198 (struct bfd_link_hash_table *, struct bfd_link_hash_entry *); 199 200 /* Remove symbols from the undefs list that don't belong there. */ 201 extern void bfd_link_repair_undef_list 202 (struct bfd_link_hash_table *table); 203 204 /* Read symbols and cache symbol pointer array in outsymbols. */ 205 extern bfd_boolean bfd_generic_link_read_symbols (bfd *); 206 207 struct bfd_sym_chain 208 { 209 struct bfd_sym_chain *next; 210 const char *name; 211 }; 212 213 /* How to handle unresolved symbols. 215 There are four possibilities which are enumerated below: */ 216 enum report_method 217 { 218 /* This is the initial value when then link_info structure is created. 219 It allows the various stages of the linker to determine whether they 220 allowed to set the value. */ 221 RM_NOT_YET_SET = 0, 222 RM_IGNORE, 223 RM_GENERATE_WARNING, 224 RM_GENERATE_ERROR 225 }; 226 227 struct bfd_elf_dynamic_list; 228 229 /* This structure holds all the information needed to communicate 230 between BFD and the linker when doing a link. */ 231 232 struct bfd_link_info 233 { 234 /* TRUE if BFD should generate a relocatable object file. */ 235 unsigned int relocatable: 1; 236 237 /* TRUE if BFD should generate relocation information in the final 238 executable. */ 239 unsigned int emitrelocations: 1; 240 241 /* TRUE if BFD should generate a "task linked" object file, 242 similar to relocatable but also with globals converted to 243 statics. */ 244 unsigned int task_link: 1; 245 246 /* TRUE if BFD should generate a shared object. */ 247 unsigned int shared: 1; 248 249 /* TRUE if BFD should pre-bind symbols in a shared object. */ 250 unsigned int symbolic: 1; 251 252 /* TRUE if BFD should export all symbols in the dynamic symbol table 253 of an executable, rather than only those used. */ 254 unsigned int export_dynamic: 1; 255 256 /* TRUE if shared objects should be linked directly, not shared. */ 257 unsigned int static_link: 1; 258 259 /* TRUE if the output file should be in a traditional format. This 260 is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag 261 on the output file, but may be checked when reading the input 262 files. */ 263 unsigned int traditional_format: 1; 264 265 /* TRUE if we want to produced optimized output files. This might 266 need much more time and therefore must be explicitly selected. */ 267 unsigned int optimize: 1; 268 269 /* TRUE if ok to have multiple definition. */ 270 unsigned int allow_multiple_definition: 1; 271 272 /* TRUE if ok to have version with no definition. */ 273 unsigned int allow_undefined_version: 1; 274 275 /* TRUE if a default symbol version should be created and used for 276 exported symbols. */ 277 unsigned int create_default_symver: 1; 278 279 /* TRUE if a default symbol version should be created and used for 280 imported symbols. */ 281 unsigned int default_imported_symver: 1; 282 283 /* TRUE if symbols should be retained in memory, FALSE if they 284 should be freed and reread. */ 285 unsigned int keep_memory: 1; 286 287 /* TRUE if every symbol should be reported back via the notice 288 callback. */ 289 unsigned int notice_all: 1; 290 291 /* TRUE if executable should not contain copy relocs. 292 Setting this true may result in a non-sharable text segment. */ 293 unsigned int nocopyreloc: 1; 294 295 /* TRUE if the new ELF dynamic tags are enabled. */ 296 unsigned int new_dtags: 1; 297 298 /* TRUE if non-PLT relocs should be merged into one reloc section 299 and sorted so that relocs against the same symbol come together. */ 300 unsigned int combreloc: 1; 301 302 /* TRUE if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment 303 should be created. */ 304 unsigned int eh_frame_hdr: 1; 305 306 /* TRUE if global symbols in discarded sections should be stripped. */ 307 unsigned int strip_discarded: 1; 308 309 /* TRUE if generating a position independent executable. */ 310 unsigned int pie: 1; 311 312 /* TRUE if generating an executable, position independent or not. */ 313 unsigned int executable : 1; 314 315 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X 316 flags. */ 317 unsigned int execstack: 1; 318 319 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W 320 flags. */ 321 unsigned int noexecstack: 1; 322 323 /* TRUE if PT_GNU_RELRO segment should be created. */ 324 unsigned int relro: 1; 325 326 /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */ 327 unsigned int warn_shared_textrel: 1; 328 329 /* TRUE if we should warn alternate ELF machine code. */ 330 unsigned int warn_alternate_em: 1; 331 332 /* TRUE if unreferenced sections should be removed. */ 333 unsigned int gc_sections: 1; 334 335 /* TRUE if user shoudl be informed of removed unreferenced sections. */ 336 unsigned int print_gc_sections: 1; 337 338 /* TRUE if .hash section should be created. */ 339 unsigned int emit_hash: 1; 340 341 /* TRUE if .gnu.hash section should be created. */ 342 unsigned int emit_gnu_hash: 1; 343 344 /* If TRUE reduce memory overheads, at the expense of speed. This will 345 cause map file generation to use an O(N^2) algorithm and disable 346 caching ELF symbol buffer. */ 347 unsigned int reduce_memory_overheads: 1; 348 349 /* TRUE if all data symbols should be dynamic. */ 350 unsigned int dynamic_data: 1; 351 352 /* TRUE if some symbols have to be dynamic, controlled by 353 --dynamic-list command line options. */ 354 unsigned int dynamic: 1; 355 356 /* Non-NULL if .note.gnu.build-id section should be created. */ 357 char *emit_note_gnu_build_id; 358 359 /* What to do with unresolved symbols in an object file. 360 When producing executables the default is GENERATE_ERROR. 361 When producing shared libraries the default is IGNORE. The 362 assumption with shared libraries is that the reference will be 363 resolved at load/execution time. */ 364 enum report_method unresolved_syms_in_objects; 365 366 /* What to do with unresolved symbols in a shared library. 367 The same defaults apply. */ 368 enum report_method unresolved_syms_in_shared_libs; 369 370 /* Which symbols to strip. */ 371 enum bfd_link_strip strip; 372 373 /* Which local symbols to discard. */ 374 enum bfd_link_discard discard; 375 376 /* Criteria for skipping symbols when detemining 377 whether to include an object from an archive. */ 378 enum bfd_link_common_skip_ar_aymbols common_skip_ar_aymbols; 379 380 /* Char that may appear as the first char of a symbol, but should be 381 skipped (like symbol_leading_char) when looking up symbols in 382 wrap_hash. Used by PowerPC Linux for 'dot' symbols. */ 383 char wrap_char; 384 385 /* Separator between archive and filename in linker script filespecs. */ 386 char path_separator; 387 388 /* Function callbacks. */ 389 const struct bfd_link_callbacks *callbacks; 390 391 /* Hash table handled by BFD. */ 392 struct bfd_link_hash_table *hash; 393 394 /* Hash table of symbols to keep. This is NULL unless strip is 395 strip_some. */ 396 struct bfd_hash_table *keep_hash; 397 398 /* Hash table of symbols to report back via the notice callback. If 399 this is NULL, and notice_all is FALSE, then no symbols are 400 reported back. */ 401 struct bfd_hash_table *notice_hash; 402 403 /* Hash table of symbols which are being wrapped (the --wrap linker 404 option). If this is NULL, no symbols are being wrapped. */ 405 struct bfd_hash_table *wrap_hash; 406 407 /* The output BFD. */ 408 bfd *output_bfd; 409 410 /* The list of input BFD's involved in the link. These are chained 411 together via the link_next field. */ 412 bfd *input_bfds; 413 bfd **input_bfds_tail; 414 415 /* If a symbol should be created for each input BFD, this is section 416 where those symbols should be placed. It must be a section in 417 the output BFD. It may be NULL, in which case no such symbols 418 will be created. This is to support CREATE_OBJECT_SYMBOLS in the 419 linker command language. */ 420 asection *create_object_symbols_section; 421 422 /* List of global symbol names that are starting points for marking 423 sections against garbage collection. */ 424 struct bfd_sym_chain *gc_sym_list; 425 426 /* If a base output file is wanted, then this points to it */ 427 void *base_file; 428 429 /* The function to call when the executable or shared object is 430 loaded. */ 431 const char *init_function; 432 433 /* The function to call when the executable or shared object is 434 unloaded. */ 435 const char *fini_function; 436 437 /* Number of relaxation passes. Usually only one relaxation pass 438 is needed. But a backend can have as many relaxation passes as 439 necessary. During bfd_relax_section call, it is set to the 440 current pass, starting from 0. */ 441 int relax_pass; 442 443 /* Number of relaxation trips. This number is incremented every 444 time the relaxation pass is restarted due to a previous 445 relaxation returning true in *AGAIN. */ 446 int relax_trip; 447 448 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs 449 should be generated/linked against. Set to 1 if this feature 450 is explicitly requested by the user, -1 if enabled by default. */ 451 int pei386_auto_import; 452 453 /* Non-zero if runtime relocs for DATA items with non-zero addends 454 in pei386 DLLs should be generated. Set to 1 if this feature 455 is explicitly requested by the user, -1 if enabled by default. */ 456 int pei386_runtime_pseudo_reloc; 457 458 /* How many spare .dynamic DT_NULL entries should be added? */ 459 unsigned int spare_dynamic_tags; 460 461 /* May be used to set DT_FLAGS for ELF. */ 462 bfd_vma flags; 463 464 /* May be used to set DT_FLAGS_1 for ELF. */ 465 bfd_vma flags_1; 466 467 /* Start and end of RELRO region. */ 468 bfd_vma relro_start, relro_end; 469 470 /* List of symbols should be dynamic. */ 471 struct bfd_elf_dynamic_list *dynamic_list; 472 }; 473 474 /* This structures holds a set of callback functions. These are called 475 by the BFD linker routines. Except for the info functions, the first 476 argument to each callback function is the bfd_link_info structure 477 being used and each function returns a boolean value. If the 478 function returns FALSE, then the BFD function which called it should 479 return with a failure indication. */ 480 481 struct bfd_link_callbacks 482 { 483 /* A function which is called when an object is added from an 484 archive. ABFD is the archive element being added. NAME is the 485 name of the symbol which caused the archive element to be pulled 486 in. */ 487 bfd_boolean (*add_archive_element) 488 (struct bfd_link_info *, bfd *abfd, const char *name); 489 /* A function which is called when a symbol is found with multiple 490 definitions. NAME is the symbol which is defined multiple times. 491 OBFD is the old BFD, OSEC is the old section, OVAL is the old 492 value, NBFD is the new BFD, NSEC is the new section, and NVAL is 493 the new value. OBFD may be NULL. OSEC and NSEC may be 494 bfd_com_section or bfd_ind_section. */ 495 bfd_boolean (*multiple_definition) 496 (struct bfd_link_info *, const char *name, 497 bfd *obfd, asection *osec, bfd_vma oval, 498 bfd *nbfd, asection *nsec, bfd_vma nval); 499 /* A function which is called when a common symbol is defined 500 multiple times. NAME is the symbol appearing multiple times. 501 OBFD is the BFD of the existing symbol; it may be NULL if this is 502 not known. OTYPE is the type of the existing symbol, which may 503 be bfd_link_hash_defined, bfd_link_hash_defweak, 504 bfd_link_hash_common, or bfd_link_hash_indirect. If OTYPE is 505 bfd_link_hash_common, OSIZE is the size of the existing symbol. 506 NBFD is the BFD of the new symbol. NTYPE is the type of the new 507 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or 508 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE 509 is the size of the new symbol. */ 510 bfd_boolean (*multiple_common) 511 (struct bfd_link_info *, const char *name, 512 bfd *obfd, enum bfd_link_hash_type otype, bfd_vma osize, 513 bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize); 514 /* A function which is called to add a symbol to a set. ENTRY is 515 the link hash table entry for the set itself (e.g., 516 __CTOR_LIST__). RELOC is the relocation to use for an entry in 517 the set when generating a relocatable file, and is also used to 518 get the size of the entry when generating an executable file. 519 ABFD, SEC and VALUE identify the value to add to the set. */ 520 bfd_boolean (*add_to_set) 521 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 522 bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value); 523 /* A function which is called when the name of a g++ constructor or 524 destructor is found. This is only called by some object file 525 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a 526 destructor. This will use BFD_RELOC_CTOR when generating a 527 relocatable file. NAME is the name of the symbol found. ABFD, 528 SECTION and VALUE are the value of the symbol. */ 529 bfd_boolean (*constructor) 530 (struct bfd_link_info *, bfd_boolean constructor, const char *name, 531 bfd *abfd, asection *sec, bfd_vma value); 532 /* A function which is called to issue a linker warning. For 533 example, this is called when there is a reference to a warning 534 symbol. WARNING is the warning to be issued. SYMBOL is the name 535 of the symbol which triggered the warning; it may be NULL if 536 there is none. ABFD, SECTION and ADDRESS identify the location 537 which trigerred the warning; either ABFD or SECTION or both may 538 be NULL if the location is not known. */ 539 bfd_boolean (*warning) 540 (struct bfd_link_info *, const char *warning, const char *symbol, 541 bfd *abfd, asection *section, bfd_vma address); 542 /* A function which is called when a relocation is attempted against 543 an undefined symbol. NAME is the symbol which is undefined. 544 ABFD, SECTION and ADDRESS identify the location from which the 545 reference is made. FATAL indicates whether an undefined symbol is 546 a fatal error or not. In some cases SECTION may be NULL. */ 547 bfd_boolean (*undefined_symbol) 548 (struct bfd_link_info *, const char *name, bfd *abfd, 549 asection *section, bfd_vma address, bfd_boolean fatal); 550 /* A function which is called when a reloc overflow occurs. ENTRY is 551 the link hash table entry for the symbol the reloc is against. 552 NAME is the name of the local symbol or section the reloc is 553 against, RELOC_NAME is the name of the relocation, and ADDEND is 554 any addend that is used. ABFD, SECTION and ADDRESS identify the 555 location at which the overflow occurs; if this is the result of a 556 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 557 ABFD will be NULL. */ 558 bfd_boolean (*reloc_overflow) 559 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 560 const char *name, const char *reloc_name, bfd_vma addend, 561 bfd *abfd, asection *section, bfd_vma address); 562 /* A function which is called when a dangerous reloc is performed. 563 MESSAGE is an appropriate message. 564 ABFD, SECTION and ADDRESS identify the location at which the 565 problem occurred; if this is the result of a 566 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 567 ABFD will be NULL. */ 568 bfd_boolean (*reloc_dangerous) 569 (struct bfd_link_info *, const char *message, 570 bfd *abfd, asection *section, bfd_vma address); 571 /* A function which is called when a reloc is found to be attached 572 to a symbol which is not being written out. NAME is the name of 573 the symbol. ABFD, SECTION and ADDRESS identify the location of 574 the reloc; if this is the result of a 575 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 576 ABFD will be NULL. */ 577 bfd_boolean (*unattached_reloc) 578 (struct bfd_link_info *, const char *name, 579 bfd *abfd, asection *section, bfd_vma address); 580 /* A function which is called when a symbol in notice_hash is 581 defined or referenced. NAME is the symbol. ABFD, SECTION and 582 ADDRESS are the value of the symbol. If SECTION is 583 bfd_und_section, this is a reference. */ 584 bfd_boolean (*notice) 585 (struct bfd_link_info *, const char *name, 586 bfd *abfd, asection *section, bfd_vma address); 587 /* Error or warning link info message. */ 588 void (*einfo) 589 (const char *fmt, ...); 590 /* General link info message. */ 591 void (*info) 592 (const char *fmt, ...); 593 /* Message to be printed in linker map file. */ 594 void (*minfo) 595 (const char *fmt, ...); 596 /* This callback provides a chance for users of the BFD library to 597 override its decision about whether to place two adjacent sections 598 into the same segment. */ 599 bfd_boolean (*override_segment_assignment) 600 (struct bfd_link_info *, bfd * abfd, 601 asection * current_section, asection * previous_section, 602 bfd_boolean new_segment); 603 }; 604 605 /* The linker builds link_order structures which tell the code how to 607 include input data in the output file. */ 608 609 /* These are the types of link_order structures. */ 610 611 enum bfd_link_order_type 612 { 613 bfd_undefined_link_order, /* Undefined. */ 614 bfd_indirect_link_order, /* Built from a section. */ 615 bfd_data_link_order, /* Set to explicit data. */ 616 bfd_section_reloc_link_order, /* Relocate against a section. */ 617 bfd_symbol_reloc_link_order /* Relocate against a symbol. */ 618 }; 619 620 /* This is the link_order structure itself. These form a chain 621 attached to the output section whose contents they are describing. */ 622 623 struct bfd_link_order 624 { 625 /* Next link_order in chain. */ 626 struct bfd_link_order *next; 627 /* Type of link_order. */ 628 enum bfd_link_order_type type; 629 /* Offset within output section. */ 630 bfd_vma offset; 631 /* Size within output section. */ 632 bfd_size_type size; 633 /* Type specific information. */ 634 union 635 { 636 struct 637 { 638 /* Section to include. If this is used, then 639 section->output_section must be the section the 640 link_order is attached to, section->output_offset must 641 equal the link_order offset field, and section->size 642 must equal the link_order size field. Maybe these 643 restrictions should be relaxed someday. */ 644 asection *section; 645 } indirect; 646 struct 647 { 648 /* Size of contents, or zero when contents size == size 649 within output section. 650 A non-zero value allows filling of the output section 651 with an arbitrary repeated pattern. */ 652 unsigned int size; 653 /* Data to put into file. */ 654 bfd_byte *contents; 655 } data; 656 struct 657 { 658 /* Description of reloc to generate. Used for 659 bfd_section_reloc_link_order and 660 bfd_symbol_reloc_link_order. */ 661 struct bfd_link_order_reloc *p; 662 } reloc; 663 } u; 664 }; 665 666 /* A linker order of type bfd_section_reloc_link_order or 667 bfd_symbol_reloc_link_order means to create a reloc against a 668 section or symbol, respectively. This is used to implement -Ur to 669 generate relocs for the constructor tables. The 670 bfd_link_order_reloc structure describes the reloc that BFD should 671 create. It is similar to a arelent, but I didn't use arelent 672 because the linker does not know anything about most symbols, and 673 any asymbol structure it creates will be partially meaningless. 674 This information could logically be in the bfd_link_order struct, 675 but I didn't want to waste the space since these types of relocs 676 are relatively rare. */ 677 678 struct bfd_link_order_reloc 679 { 680 /* Reloc type. */ 681 bfd_reloc_code_real_type reloc; 682 683 union 684 { 685 /* For type bfd_section_reloc_link_order, this is the section 686 the reloc should be against. This must be a section in the 687 output BFD, not any of the input BFDs. */ 688 asection *section; 689 /* For type bfd_symbol_reloc_link_order, this is the name of the 690 symbol the reloc should be against. */ 691 const char *name; 692 } u; 693 694 /* Addend to use. The object file should contain zero. The BFD 695 backend is responsible for filling in the contents of the object 696 file correctly. For some object file formats (e.g., COFF) the 697 addend must be stored into in the object file, and for some 698 (e.g., SPARC a.out) it is kept in the reloc. */ 699 bfd_vma addend; 700 }; 701 702 /* Allocate a new link_order for a section. */ 703 extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *); 704 705 /* These structures are used to describe version information for the 706 ELF linker. These structures could be manipulated entirely inside 707 BFD, but it would be a pain. Instead, the regular linker sets up 708 these structures, and then passes them into BFD. */ 709 710 /* Glob pattern for a version. */ 711 712 struct bfd_elf_version_expr 713 { 714 /* Next glob pattern for this version. */ 715 struct bfd_elf_version_expr *next; 716 /* Glob pattern. */ 717 const char *pattern; 718 /* Set if pattern is not a glob. */ 719 unsigned int literal : 1; 720 /* Defined by ".symver". */ 721 unsigned int symver : 1; 722 /* Defined by version script. */ 723 unsigned int script : 1; 724 /* Pattern type. */ 725 #define BFD_ELF_VERSION_C_TYPE 1 726 #define BFD_ELF_VERSION_CXX_TYPE 2 727 #define BFD_ELF_VERSION_JAVA_TYPE 4 728 unsigned int mask : 3; 729 }; 730 731 struct bfd_elf_version_expr_head 732 { 733 /* List of all patterns, both wildcards and non-wildcards. */ 734 struct bfd_elf_version_expr *list; 735 /* Hash table for non-wildcards. */ 736 void *htab; 737 /* Remaining patterns. */ 738 struct bfd_elf_version_expr *remaining; 739 /* What kind of pattern types are present in list (bitmask). */ 740 unsigned int mask; 741 }; 742 743 /* Version dependencies. */ 744 745 struct bfd_elf_version_deps 746 { 747 /* Next dependency for this version. */ 748 struct bfd_elf_version_deps *next; 749 /* The version which this version depends upon. */ 750 struct bfd_elf_version_tree *version_needed; 751 }; 752 753 /* A node in the version tree. */ 754 755 struct bfd_elf_version_tree 756 { 757 /* Next version. */ 758 struct bfd_elf_version_tree *next; 759 /* Name of this version. */ 760 const char *name; 761 /* Version number. */ 762 unsigned int vernum; 763 /* Regular expressions for global symbols in this version. */ 764 struct bfd_elf_version_expr_head globals; 765 /* Regular expressions for local symbols in this version. */ 766 struct bfd_elf_version_expr_head locals; 767 /* List of versions which this version depends upon. */ 768 struct bfd_elf_version_deps *deps; 769 /* Index of the version name. This is used within BFD. */ 770 unsigned int name_indx; 771 /* Whether this version tree was used. This is used within BFD. */ 772 int used; 773 /* Matching hook. */ 774 struct bfd_elf_version_expr *(*match) 775 (struct bfd_elf_version_expr_head *head, 776 struct bfd_elf_version_expr *prev, const char *sym); 777 }; 778 779 struct bfd_elf_dynamic_list 780 { 781 struct bfd_elf_version_expr_head head; 782 struct bfd_elf_version_expr *(*match) 783 (struct bfd_elf_version_expr_head *head, 784 struct bfd_elf_version_expr *prev, const char *sym); 785 }; 786 787 #endif 788