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 56 table. */ 57 58 enum bfd_link_hash_type 59 { 60 bfd_link_hash_new, /* Symbol is new. */ 61 bfd_link_hash_undefined, /* Symbol seen before, but undefined. */ 62 bfd_link_hash_undefweak, /* Symbol is weak and undefined. */ 63 bfd_link_hash_defined, /* Symbol is defined. */ 64 bfd_link_hash_defweak, /* Symbol is weak and defined. */ 65 bfd_link_hash_common, /* Symbol is common. */ 66 bfd_link_hash_indirect, /* Symbol is an indirect link. */ 67 bfd_link_hash_warning /* Like indirect, but warn if referenced. */ 68 }; 69 70 enum bfd_link_common_skip_ar_aymbols 71 { 72 bfd_link_common_skip_none, 73 bfd_link_common_skip_text, 74 bfd_link_common_skip_data, 75 bfd_link_common_skip_all 76 }; 77 78 struct bfd_link_hash_common_entry 79 { 80 unsigned int alignment_power; /* Alignment. */ 81 asection *section; /* Symbol section. */ 82 }; 83 84 /* The linking routines use a hash table which uses this structure for 85 its elements. */ 86 87 struct bfd_link_hash_entry 88 { 89 /* Base hash table entry structure. */ 90 struct bfd_hash_entry root; 91 92 /* Type of this entry. */ 93 enum bfd_link_hash_type type; 94 95 /* A union of information depending upon the type. */ 96 union 97 { 98 /* Nothing is kept for bfd_hash_new. */ 99 /* bfd_link_hash_undefined, bfd_link_hash_undefweak. */ 100 struct 101 { 102 /* Undefined and common symbols are kept in a linked list through 103 this field. This field is present in all of the union element 104 so that we don't need to remove entries from the list when we 105 change their type. Removing entries would either require the 106 list to be doubly linked, which would waste more memory, or 107 require a traversal. When an undefined or common symbol is 108 created, it should be added to this list, the head of which is in 109 the link hash table itself. As symbols are defined, they need 110 not be removed from the list; anything which reads the list must 111 doublecheck the symbol type. 112 113 Weak symbols are not kept on this list. 114 115 Defined and defweak symbols use this field as a reference marker. 116 If the field is not NULL, or this structure is the tail of the 117 undefined symbol list, the symbol has been referenced. If the 118 symbol is undefined and becomes defined, this field will 119 automatically be non-NULL since the symbol will have been on the 120 undefined symbol list. */ 121 struct bfd_link_hash_entry *next; 122 bfd *abfd; /* BFD symbol was found in. */ 123 bfd *weak; /* BFD weak symbol was found in. */ 124 } undef; 125 /* bfd_link_hash_defined, bfd_link_hash_defweak. */ 126 struct 127 { 128 struct bfd_link_hash_entry *next; 129 asection *section; /* Symbol section. */ 130 bfd_vma value; /* Symbol value. */ 131 } def; 132 /* bfd_link_hash_indirect, bfd_link_hash_warning. */ 133 struct 134 { 135 struct bfd_link_hash_entry *next; 136 struct bfd_link_hash_entry *link; /* Real symbol. */ 137 const char *warning; /* Warning (bfd_link_hash_warning only). */ 138 } i; 139 /* bfd_link_hash_common. */ 140 struct 141 { 142 struct bfd_link_hash_entry *next; 143 /* The linker needs to know three things about common 144 symbols: the size, the alignment, and the section in 145 which the symbol should be placed. We store the size 146 here, and we allocate a small structure to hold the 147 section and the alignment. The alignment is stored as a 148 power of two. We don't store all the information 149 directly because we don't want to increase the size of 150 the union; this structure is a major space user in the 151 linker. */ 152 struct bfd_link_hash_common_entry *p; 153 bfd_size_type size; /* Common symbol size. */ 154 } c; 155 } u; 156 }; 157 158 /* This is the link hash table. It is a derived class of 159 bfd_hash_table. */ 160 161 struct bfd_link_hash_table 162 { 163 /* The hash table itself. */ 164 struct bfd_hash_table table; 165 /* A linked list of undefined and common symbols, linked through the 166 next field in the bfd_link_hash_entry structure. */ 167 struct bfd_link_hash_entry *undefs; 168 /* Entries are added to the tail of the undefs list. */ 169 struct bfd_link_hash_entry *undefs_tail; 170 /* The type of the link hash table. */ 171 enum bfd_link_hash_table_type type; 172 }; 173 174 /* Look up an entry in a link hash table. If FOLLOW is TRUE, this 175 follows bfd_link_hash_indirect and bfd_link_hash_warning links to 176 the real symbol. */ 177 extern struct bfd_link_hash_entry *bfd_link_hash_lookup 178 (struct bfd_link_hash_table *, const char *, bfd_boolean create, 179 bfd_boolean copy, bfd_boolean follow); 180 181 /* Look up an entry in the main linker hash table if the symbol might 182 be wrapped. This should only be used for references to an 183 undefined symbol, not for definitions of a symbol. */ 184 185 extern struct bfd_link_hash_entry *bfd_wrapped_link_hash_lookup 186 (bfd *, struct bfd_link_info *, const char *, bfd_boolean, 187 bfd_boolean, bfd_boolean); 188 189 /* Traverse a link hash table. */ 190 extern void bfd_link_hash_traverse 191 (struct bfd_link_hash_table *, 192 bfd_boolean (*) (struct bfd_link_hash_entry *, void *), 193 void *); 194 195 /* Add an entry to the undefs list. */ 196 extern void bfd_link_add_undef 197 (struct bfd_link_hash_table *, struct bfd_link_hash_entry *); 198 199 /* Remove symbols from the undefs list that don't belong there. */ 200 extern void bfd_link_repair_undef_list 201 (struct bfd_link_hash_table *table); 202 203 /* Read symbols and cache symbol pointer array in outsymbols. */ 204 extern bfd_boolean bfd_generic_link_read_symbols (bfd *); 205 206 struct bfd_sym_chain 207 { 208 struct bfd_sym_chain *next; 209 const char *name; 210 }; 211 212 /* How to handle unresolved symbols. 213 There are four possibilities which are enumerated below: */ 214 enum report_method 215 { 216 /* This is the initial value when then link_info structure is created. 217 It allows the various stages of the linker to determine whether they 218 allowed to set the value. */ 219 RM_NOT_YET_SET = 0, 220 RM_IGNORE, 221 RM_GENERATE_WARNING, 222 RM_GENERATE_ERROR 223 }; 224 225 struct bfd_elf_dynamic_list; 226 227 /* This structure holds all the information needed to communicate 228 between BFD and the linker when doing a link. */ 229 230 struct bfd_link_info 231 { 232 /* TRUE if BFD should generate a relocatable object file. */ 233 unsigned int relocatable: 1; 234 235 /* TRUE if BFD should generate relocation information in the final 236 executable. */ 237 unsigned int emitrelocations: 1; 238 239 /* TRUE if BFD should generate a "task linked" object file, 240 similar to relocatable but also with globals converted to 241 statics. */ 242 unsigned int task_link: 1; 243 244 /* TRUE if BFD should generate a shared object. */ 245 unsigned int shared: 1; 246 247 /* TRUE if BFD should pre-bind symbols in a shared object. */ 248 unsigned int symbolic: 1; 249 250 /* TRUE if BFD should export all symbols in the dynamic symbol table 251 of an executable, rather than only those used. */ 252 unsigned int export_dynamic: 1; 253 254 /* TRUE if shared objects should be linked directly, not shared. */ 255 unsigned int static_link: 1; 256 257 /* TRUE if the output file should be in a traditional format. This 258 is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag 259 on the output file, but may be checked when reading the input 260 files. */ 261 unsigned int traditional_format: 1; 262 263 /* TRUE if we want to produced optimized output files. This might 264 need much more time and therefore must be explicitly selected. */ 265 unsigned int optimize: 1; 266 267 /* TRUE if ok to have multiple definition. */ 268 unsigned int allow_multiple_definition: 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 we should warn alternate ELF machine code. */ 328 unsigned int warn_alternate_em: 1; 329 330 /* TRUE if unreferenced sections should be removed. */ 331 unsigned int gc_sections: 1; 332 333 /* TRUE if user shoudl be informed of removed unreferenced sections. */ 334 unsigned int print_gc_sections: 1; 335 336 /* TRUE if .hash section should be created. */ 337 unsigned int emit_hash: 1; 338 339 /* TRUE if .gnu.hash section should be created. */ 340 unsigned int emit_gnu_hash: 1; 341 342 /* If TRUE reduce memory overheads, at the expense of speed. This will 343 cause map file generation to use an O(N^2) algorithm and disable 344 caching ELF symbol buffer. */ 345 unsigned int reduce_memory_overheads: 1; 346 347 /* TRUE if all data symbols should be dynamic. */ 348 unsigned int dynamic_data: 1; 349 350 /* TRUE if some symbols have to be dynamic, controlled by 351 --dynamic-list command line options. */ 352 unsigned int dynamic: 1; 353 354 /* Non-NULL if .note.gnu.build-id section should be created. */ 355 char *emit_note_gnu_build_id; 356 357 /* What to do with unresolved symbols in an object file. 358 When producing executables the default is GENERATE_ERROR. 359 When producing shared libraries the default is IGNORE. The 360 assumption with shared libraries is that the reference will be 361 resolved at load/execution time. */ 362 enum report_method unresolved_syms_in_objects; 363 364 /* What to do with unresolved symbols in a shared library. 365 The same defaults apply. */ 366 enum report_method unresolved_syms_in_shared_libs; 367 368 /* Which symbols to strip. */ 369 enum bfd_link_strip strip; 370 371 /* Which local symbols to discard. */ 372 enum bfd_link_discard discard; 373 374 /* Criteria for skipping symbols when detemining 375 whether to include an object from an archive. */ 376 enum bfd_link_common_skip_ar_aymbols common_skip_ar_aymbols; 377 378 /* Char that may appear as the first char of a symbol, but should be 379 skipped (like symbol_leading_char) when looking up symbols in 380 wrap_hash. Used by PowerPC Linux for 'dot' symbols. */ 381 char wrap_char; 382 383 /* Separator between archive and filename in linker script filespecs. */ 384 char path_separator; 385 386 /* Function callbacks. */ 387 const struct bfd_link_callbacks *callbacks; 388 389 /* Hash table handled by BFD. */ 390 struct bfd_link_hash_table *hash; 391 392 /* Hash table of symbols to keep. This is NULL unless strip is 393 strip_some. */ 394 struct bfd_hash_table *keep_hash; 395 396 /* Hash table of symbols to report back via the notice callback. If 397 this is NULL, and notice_all is FALSE, then no symbols are 398 reported back. */ 399 struct bfd_hash_table *notice_hash; 400 401 /* Hash table of symbols which are being wrapped (the --wrap linker 402 option). If this is NULL, no symbols are being wrapped. */ 403 struct bfd_hash_table *wrap_hash; 404 405 /* The output BFD. */ 406 bfd *output_bfd; 407 408 /* The list of input BFD's involved in the link. These are chained 409 together via the link_next field. */ 410 bfd *input_bfds; 411 bfd **input_bfds_tail; 412 413 /* If a symbol should be created for each input BFD, this is section 414 where those symbols should be placed. It must be a section in 415 the output BFD. It may be NULL, in which case no such symbols 416 will be created. This is to support CREATE_OBJECT_SYMBOLS in the 417 linker command language. */ 418 asection *create_object_symbols_section; 419 420 /* List of global symbol names that are starting points for marking 421 sections against garbage collection. */ 422 struct bfd_sym_chain *gc_sym_list; 423 424 /* If a base output file is wanted, then this points to it */ 425 void *base_file; 426 427 /* The function to call when the executable or shared object is 428 loaded. */ 429 const char *init_function; 430 431 /* The function to call when the executable or shared object is 432 unloaded. */ 433 const char *fini_function; 434 435 /* Number of relaxation passes. Usually only one relaxation pass 436 is needed. But a backend can have as many relaxation passes as 437 necessary. During bfd_relax_section call, it is set to the 438 current pass, starting from 0. */ 439 int relax_pass; 440 441 /* Number of relaxation trips. This number is incremented every 442 time the relaxation pass is restarted due to a previous 443 relaxation returning true in *AGAIN. */ 444 int relax_trip; 445 446 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs 447 should be generated/linked against. Set to 1 if this feature 448 is explicitly requested by the user, -1 if enabled by default. */ 449 int pei386_auto_import; 450 451 /* Non-zero if runtime relocs for DATA items with non-zero addends 452 in pei386 DLLs should be generated. Set to 1 if this feature 453 is explicitly requested by the user, -1 if enabled by default. */ 454 int pei386_runtime_pseudo_reloc; 455 456 /* How many spare .dynamic DT_NULL entries should be added? */ 457 unsigned int spare_dynamic_tags; 458 459 /* May be used to set DT_FLAGS for ELF. */ 460 bfd_vma flags; 461 462 /* May be used to set DT_FLAGS_1 for ELF. */ 463 bfd_vma flags_1; 464 465 /* Start and end of RELRO region. */ 466 bfd_vma relro_start, relro_end; 467 468 /* List of symbols should be dynamic. */ 469 struct bfd_elf_dynamic_list *dynamic_list; 470 }; 471 472 /* This structures holds a set of callback functions. These are called 473 by the BFD linker routines. Except for the info functions, the first 474 argument to each callback function is the bfd_link_info structure 475 being used and each function returns a boolean value. If the 476 function returns FALSE, then the BFD function which called it should 477 return with a failure indication. */ 478 479 struct bfd_link_callbacks 480 { 481 /* A function which is called when an object is added from an 482 archive. ABFD is the archive element being added. NAME is the 483 name of the symbol which caused the archive element to be pulled 484 in. */ 485 bfd_boolean (*add_archive_element) 486 (struct bfd_link_info *, bfd *abfd, const char *name); 487 /* A function which is called when a symbol is found with multiple 488 definitions. NAME is the symbol which is defined multiple times. 489 OBFD is the old BFD, OSEC is the old section, OVAL is the old 490 value, NBFD is the new BFD, NSEC is the new section, and NVAL is 491 the new value. OBFD may be NULL. OSEC and NSEC may be 492 bfd_com_section or bfd_ind_section. */ 493 bfd_boolean (*multiple_definition) 494 (struct bfd_link_info *, const char *name, 495 bfd *obfd, asection *osec, bfd_vma oval, 496 bfd *nbfd, asection *nsec, bfd_vma nval); 497 /* A function which is called when a common symbol is defined 498 multiple times. NAME is the symbol appearing multiple times. 499 OBFD is the BFD of the existing symbol; it may be NULL if this is 500 not known. OTYPE is the type of the existing symbol, which may 501 be bfd_link_hash_defined, bfd_link_hash_defweak, 502 bfd_link_hash_common, or bfd_link_hash_indirect. If OTYPE is 503 bfd_link_hash_common, OSIZE is the size of the existing symbol. 504 NBFD is the BFD of the new symbol. NTYPE is the type of the new 505 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or 506 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE 507 is the size of the new symbol. */ 508 bfd_boolean (*multiple_common) 509 (struct bfd_link_info *, const char *name, 510 bfd *obfd, enum bfd_link_hash_type otype, bfd_vma osize, 511 bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize); 512 /* A function which is called to add a symbol to a set. ENTRY is 513 the link hash table entry for the set itself (e.g., 514 __CTOR_LIST__). RELOC is the relocation to use for an entry in 515 the set when generating a relocatable file, and is also used to 516 get the size of the entry when generating an executable file. 517 ABFD, SEC and VALUE identify the value to add to the set. */ 518 bfd_boolean (*add_to_set) 519 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 520 bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value); 521 /* A function which is called when the name of a g++ constructor or 522 destructor is found. This is only called by some object file 523 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a 524 destructor. This will use BFD_RELOC_CTOR when generating a 525 relocatable file. NAME is the name of the symbol found. ABFD, 526 SECTION and VALUE are the value of the symbol. */ 527 bfd_boolean (*constructor) 528 (struct bfd_link_info *, bfd_boolean constructor, const char *name, 529 bfd *abfd, asection *sec, bfd_vma value); 530 /* A function which is called to issue a linker warning. For 531 example, this is called when there is a reference to a warning 532 symbol. WARNING is the warning to be issued. SYMBOL is the name 533 of the symbol which triggered the warning; it may be NULL if 534 there is none. ABFD, SECTION and ADDRESS identify the location 535 which trigerred the warning; either ABFD or SECTION or both may 536 be NULL if the location is not known. */ 537 bfd_boolean (*warning) 538 (struct bfd_link_info *, const char *warning, const char *symbol, 539 bfd *abfd, asection *section, bfd_vma address); 540 /* A function which is called when a relocation is attempted against 541 an undefined symbol. NAME is the symbol which is undefined. 542 ABFD, SECTION and ADDRESS identify the location from which the 543 reference is made. FATAL indicates whether an undefined symbol is 544 a fatal error or not. In some cases SECTION may be NULL. */ 545 bfd_boolean (*undefined_symbol) 546 (struct bfd_link_info *, const char *name, bfd *abfd, 547 asection *section, bfd_vma address, bfd_boolean fatal); 548 /* A function which is called when a reloc overflow occurs. ENTRY is 549 the link hash table entry for the symbol the reloc is against. 550 NAME is the name of the local symbol or section the reloc is 551 against, RELOC_NAME is the name of the relocation, and ADDEND is 552 any addend that is used. ABFD, SECTION and ADDRESS identify the 553 location at which the overflow occurs; if this is the result of a 554 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 555 ABFD will be NULL. */ 556 bfd_boolean (*reloc_overflow) 557 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 558 const char *name, const char *reloc_name, bfd_vma addend, 559 bfd *abfd, asection *section, bfd_vma address); 560 /* A function which is called when a dangerous reloc is performed. 561 MESSAGE is an appropriate message. 562 ABFD, SECTION and ADDRESS identify the location at which the 563 problem occurred; if this is the result of a 564 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 565 ABFD will be NULL. */ 566 bfd_boolean (*reloc_dangerous) 567 (struct bfd_link_info *, const char *message, 568 bfd *abfd, asection *section, bfd_vma address); 569 /* A function which is called when a reloc is found to be attached 570 to a symbol which is not being written out. NAME is the name of 571 the symbol. ABFD, SECTION and ADDRESS identify the location of 572 the reloc; if this is the result of a 573 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 574 ABFD will be NULL. */ 575 bfd_boolean (*unattached_reloc) 576 (struct bfd_link_info *, const char *name, 577 bfd *abfd, asection *section, bfd_vma address); 578 /* A function which is called when a symbol in notice_hash is 579 defined or referenced. NAME is the symbol. ABFD, SECTION and 580 ADDRESS are the value of the symbol. If SECTION is 581 bfd_und_section, this is a reference. */ 582 bfd_boolean (*notice) 583 (struct bfd_link_info *, const char *name, 584 bfd *abfd, asection *section, bfd_vma address); 585 /* Error or warning link info message. */ 586 void (*einfo) 587 (const char *fmt, ...); 588 /* General link info message. */ 589 void (*info) 590 (const char *fmt, ...); 591 /* Message to be printed in linker map file. */ 592 void (*minfo) 593 (const char *fmt, ...); 594 /* This callback provides a chance for users of the BFD library to 595 override its decision about whether to place two adjacent sections 596 into the same segment. */ 597 bfd_boolean (*override_segment_assignment) 598 (struct bfd_link_info *, bfd * abfd, 599 asection * current_section, asection * previous_section, 600 bfd_boolean new_segment); 601 }; 602 603 /* The linker builds link_order structures which tell the code how to 604 include input data in the output file. */ 605 606 /* These are the types of link_order structures. */ 607 608 enum bfd_link_order_type 609 { 610 bfd_undefined_link_order, /* Undefined. */ 611 bfd_indirect_link_order, /* Built from a section. */ 612 bfd_data_link_order, /* Set to explicit data. */ 613 bfd_section_reloc_link_order, /* Relocate against a section. */ 614 bfd_symbol_reloc_link_order /* Relocate against a symbol. */ 615 }; 616 617 /* This is the link_order structure itself. These form a chain 618 attached to the output section whose contents they are describing. */ 619 620 struct bfd_link_order 621 { 622 /* Next link_order in chain. */ 623 struct bfd_link_order *next; 624 /* Type of link_order. */ 625 enum bfd_link_order_type type; 626 /* Offset within output section. */ 627 bfd_vma offset; 628 /* Size within output section. */ 629 bfd_size_type size; 630 /* Type specific information. */ 631 union 632 { 633 struct 634 { 635 /* Section to include. If this is used, then 636 section->output_section must be the section the 637 link_order is attached to, section->output_offset must 638 equal the link_order offset field, and section->size 639 must equal the link_order size field. Maybe these 640 restrictions should be relaxed someday. */ 641 asection *section; 642 } indirect; 643 struct 644 { 645 /* Size of contents, or zero when contents size == size 646 within output section. 647 A non-zero value allows filling of the output section 648 with an arbitrary repeated pattern. */ 649 unsigned int size; 650 /* Data to put into file. */ 651 bfd_byte *contents; 652 } data; 653 struct 654 { 655 /* Description of reloc to generate. Used for 656 bfd_section_reloc_link_order and 657 bfd_symbol_reloc_link_order. */ 658 struct bfd_link_order_reloc *p; 659 } reloc; 660 } u; 661 }; 662 663 /* A linker order of type bfd_section_reloc_link_order or 664 bfd_symbol_reloc_link_order means to create a reloc against a 665 section or symbol, respectively. This is used to implement -Ur to 666 generate relocs for the constructor tables. The 667 bfd_link_order_reloc structure describes the reloc that BFD should 668 create. It is similar to a arelent, but I didn't use arelent 669 because the linker does not know anything about most symbols, and 670 any asymbol structure it creates will be partially meaningless. 671 This information could logically be in the bfd_link_order struct, 672 but I didn't want to waste the space since these types of relocs 673 are relatively rare. */ 674 675 struct bfd_link_order_reloc 676 { 677 /* Reloc type. */ 678 bfd_reloc_code_real_type reloc; 679 680 union 681 { 682 /* For type bfd_section_reloc_link_order, this is the section 683 the reloc should be against. This must be a section in the 684 output BFD, not any of the input BFDs. */ 685 asection *section; 686 /* For type bfd_symbol_reloc_link_order, this is the name of the 687 symbol the reloc should be against. */ 688 const char *name; 689 } u; 690 691 /* Addend to use. The object file should contain zero. The BFD 692 backend is responsible for filling in the contents of the object 693 file correctly. For some object file formats (e.g., COFF) the 694 addend must be stored into in the object file, and for some 695 (e.g., SPARC a.out) it is kept in the reloc. */ 696 bfd_vma addend; 697 }; 698 699 /* Allocate a new link_order for a section. */ 700 extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *); 701 702 /* These structures are used to describe version information for the 703 ELF linker. These structures could be manipulated entirely inside 704 BFD, but it would be a pain. Instead, the regular linker sets up 705 these structures, and then passes them into BFD. */ 706 707 /* Glob pattern for a version. */ 708 709 struct bfd_elf_version_expr 710 { 711 /* Next glob pattern for this version. */ 712 struct bfd_elf_version_expr *next; 713 /* Glob pattern. */ 714 const char *pattern; 715 /* Set if pattern is not a glob. */ 716 unsigned int literal : 1; 717 /* Defined by ".symver". */ 718 unsigned int symver : 1; 719 /* Defined by version script. */ 720 unsigned int script : 1; 721 /* Pattern type. */ 722 #define BFD_ELF_VERSION_C_TYPE 1 723 #define BFD_ELF_VERSION_CXX_TYPE 2 724 #define BFD_ELF_VERSION_JAVA_TYPE 4 725 unsigned int mask : 3; 726 }; 727 728 struct bfd_elf_version_expr_head 729 { 730 /* List of all patterns, both wildcards and non-wildcards. */ 731 struct bfd_elf_version_expr *list; 732 /* Hash table for non-wildcards. */ 733 void *htab; 734 /* Remaining patterns. */ 735 struct bfd_elf_version_expr *remaining; 736 /* What kind of pattern types are present in list (bitmask). */ 737 unsigned int mask; 738 }; 739 740 /* Version dependencies. */ 741 742 struct bfd_elf_version_deps 743 { 744 /* Next dependency for this version. */ 745 struct bfd_elf_version_deps *next; 746 /* The version which this version depends upon. */ 747 struct bfd_elf_version_tree *version_needed; 748 }; 749 750 /* A node in the version tree. */ 751 752 struct bfd_elf_version_tree 753 { 754 /* Next version. */ 755 struct bfd_elf_version_tree *next; 756 /* Name of this version. */ 757 const char *name; 758 /* Version number. */ 759 unsigned int vernum; 760 /* Regular expressions for global symbols in this version. */ 761 struct bfd_elf_version_expr_head globals; 762 /* Regular expressions for local symbols in this version. */ 763 struct bfd_elf_version_expr_head locals; 764 /* List of versions which this version depends upon. */ 765 struct bfd_elf_version_deps *deps; 766 /* Index of the version name. This is used within BFD. */ 767 unsigned int name_indx; 768 /* Whether this version tree was used. This is used within BFD. */ 769 int used; 770 /* Matching hook. */ 771 struct bfd_elf_version_expr *(*match) 772 (struct bfd_elf_version_expr_head *head, 773 struct bfd_elf_version_expr *prev, const char *sym); 774 }; 775 776 struct bfd_elf_dynamic_list 777 { 778 struct bfd_elf_version_expr_head head; 779 struct bfd_elf_version_expr *(*match) 780 (struct bfd_elf_version_expr_head *head, 781 struct bfd_elf_version_expr *prev, const char *sym); 782 }; 783 784 #endif 785