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, 2010, 2011 4 Free Software Foundation, Inc. 5 Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support. 6 7 This file is part of BFD, the Binary File Descriptor library. 8 9 This program is free software; you can redistribute it and/or modify 10 it under the terms of the GNU General Public License as published by 11 the Free Software Foundation; either version 3 of the License, or 12 (at your option) any later version. 13 14 This program is distributed in the hope that it will be useful, 15 but WITHOUT ANY WARRANTY; without even the implied warranty of 16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 GNU General Public License for more details. 18 19 You should have received a copy of the GNU General Public License 20 along with this program; if not, write to the Free Software 21 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 22 MA 02110-1301, USA. */ 23 24 #ifndef BFDLINK_H 25 #define BFDLINK_H 26 27 /* Which symbols to strip during a link. */ 28 enum bfd_link_strip 29 { 30 strip_none, /* Don't strip any symbols. */ 31 strip_debugger, /* Strip debugging symbols. */ 32 strip_some, /* keep_hash is the list of symbols to keep. */ 33 strip_all /* Strip all symbols. */ 34 }; 35 36 /* Which local symbols to discard during a link. This is irrelevant 37 if strip_all is used. */ 38 enum bfd_link_discard 39 { 40 discard_sec_merge, /* Discard local temporary symbols in SEC_MERGE 41 sections. */ 42 discard_none, /* Don't discard any locals. */ 43 discard_l, /* Discard local temporary symbols. */ 44 discard_all /* Discard all locals. */ 45 }; 46 47 /* Describes the type of hash table entry structure being used. 48 Different hash table structure have different fields and so 49 support different linking features. */ 50 enum bfd_link_hash_table_type 51 { 52 bfd_link_generic_hash_table, 53 bfd_link_elf_hash_table 54 }; 55 56 /* 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_symbols 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_BITFIELD (bfd_link_hash_type) type : 8; 95 96 unsigned int non_ir_ref : 1; 97 98 /* A union of information depending upon the type. */ 99 union 100 { 101 /* Nothing is kept for bfd_hash_new. */ 102 /* bfd_link_hash_undefined, bfd_link_hash_undefweak. */ 103 struct 104 { 105 /* Undefined and common symbols are kept in a linked list through 106 this field. This field is present in all of the union element 107 so that we don't need to remove entries from the list when we 108 change their type. Removing entries would either require the 109 list to be doubly linked, which would waste more memory, or 110 require a traversal. When an undefined or common symbol is 111 created, it should be added to this list, the head of which is in 112 the link hash table itself. As symbols are defined, they need 113 not be removed from the list; anything which reads the list must 114 doublecheck the symbol type. 115 116 Weak symbols are not kept on this list. 117 118 Defined and defweak symbols use this field as a reference marker. 119 If the field is not NULL, or this structure is the tail of the 120 undefined symbol list, the symbol has been referenced. If the 121 symbol is undefined and becomes defined, this field will 122 automatically be non-NULL since the symbol will have been on the 123 undefined symbol list. */ 124 struct bfd_link_hash_entry *next; 125 bfd *abfd; /* BFD symbol was found in. */ 126 } undef; 127 /* bfd_link_hash_defined, bfd_link_hash_defweak. */ 128 struct 129 { 130 struct bfd_link_hash_entry *next; 131 asection *section; /* Symbol section. */ 132 bfd_vma value; /* Symbol value. */ 133 } def; 134 /* bfd_link_hash_indirect, bfd_link_hash_warning. */ 135 struct 136 { 137 struct bfd_link_hash_entry *next; 138 struct bfd_link_hash_entry *link; /* Real symbol. */ 139 const char *warning; /* Warning (bfd_link_hash_warning only). */ 140 } i; 141 /* bfd_link_hash_common. */ 142 struct 143 { 144 struct bfd_link_hash_entry *next; 145 /* The linker needs to know three things about common 146 symbols: the size, the alignment, and the section in 147 which the symbol should be placed. We store the size 148 here, and we allocate a small structure to hold the 149 section and the alignment. The alignment is stored as a 150 power of two. We don't store all the information 151 directly because we don't want to increase the size of 152 the union; this structure is a major space user in the 153 linker. */ 154 struct bfd_link_hash_common_entry *p; 155 bfd_size_type size; /* Common symbol size. */ 156 } c; 157 } u; 158 }; 159 160 /* This is the link hash table. It is a derived class of 161 bfd_hash_table. */ 162 163 struct bfd_link_hash_table 164 { 165 /* The hash table itself. */ 166 struct bfd_hash_table table; 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 /* Read symbols and cache symbol pointer array in outsymbols. */ 206 extern bfd_boolean bfd_generic_link_read_symbols (bfd *); 207 208 struct bfd_sym_chain 209 { 210 struct bfd_sym_chain *next; 211 const char *name; 212 }; 213 214 /* 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 typedef enum {with_flags, without_flags} flag_type; 228 229 /* A section flag list. */ 230 struct flag_info_list 231 { 232 flag_type with; 233 const char *name; 234 bfd_boolean valid; 235 struct flag_info_list *next; 236 }; 237 238 /* Section flag info. */ 239 struct flag_info 240 { 241 flagword only_with_flags; 242 flagword not_with_flags; 243 struct flag_info_list *flag_list; 244 bfd_boolean flags_initialized; 245 }; 246 247 struct bfd_elf_dynamic_list; 248 struct bfd_elf_version_tree; 249 250 /* This structure holds all the information needed to communicate 251 between BFD and the linker when doing a link. */ 252 253 struct bfd_link_info 254 { 255 /* TRUE if BFD should generate a shared object (or a pie). */ 256 unsigned int shared: 1; 257 258 /* TRUE if generating an executable, position independent or not. */ 259 unsigned int executable : 1; 260 261 /* TRUE if generating a position independent executable. */ 262 unsigned int pie: 1; 263 264 /* TRUE if BFD should generate a relocatable object file. */ 265 unsigned int relocatable: 1; 266 267 /* TRUE if BFD should pre-bind symbols in a shared object. */ 268 unsigned int symbolic: 1; 269 270 /* TRUE if executable should not contain copy relocs. 271 Setting this true may result in a non-sharable text segment. */ 272 unsigned int nocopyreloc: 1; 273 274 /* TRUE if BFD should export all symbols in the dynamic symbol table 275 of an executable, rather than only those used. */ 276 unsigned int export_dynamic: 1; 277 278 /* TRUE if a default symbol version should be created and used for 279 exported symbols. */ 280 unsigned int create_default_symver: 1; 281 282 /* TRUE if unreferenced sections should be removed. */ 283 unsigned int gc_sections: 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 we are loading LTO outputs. */ 290 unsigned int loading_lto_outputs: 1; 291 292 /* TRUE if global symbols in discarded sections should be stripped. */ 293 unsigned int strip_discarded: 1; 294 295 /* TRUE if all data symbols should be dynamic. */ 296 unsigned int dynamic_data: 1; 297 298 /* Which symbols to strip. */ 299 ENUM_BITFIELD (bfd_link_strip) strip : 2; 300 301 /* Which local symbols to discard. */ 302 ENUM_BITFIELD (bfd_link_discard) discard : 2; 303 304 /* Criteria for skipping symbols when determining 305 whether to include an object from an archive. */ 306 ENUM_BITFIELD (bfd_link_common_skip_ar_symbols) common_skip_ar_symbols : 2; 307 308 /* What to do with unresolved symbols in an object file. 309 When producing executables the default is GENERATE_ERROR. 310 When producing shared libraries the default is IGNORE. The 311 assumption with shared libraries is that the reference will be 312 resolved at load/execution time. */ 313 ENUM_BITFIELD (report_method) unresolved_syms_in_objects : 2; 314 315 /* What to do with unresolved symbols in a shared library. 316 The same defaults apply. */ 317 ENUM_BITFIELD (report_method) unresolved_syms_in_shared_libs : 2; 318 319 /* TRUE if shared objects should be linked directly, not shared. */ 320 unsigned int static_link: 1; 321 322 /* TRUE if symbols should be retained in memory, FALSE if they 323 should be freed and reread. */ 324 unsigned int keep_memory: 1; 325 326 /* TRUE if BFD should generate relocation information in the final 327 executable. */ 328 unsigned int emitrelocations: 1; 329 330 /* TRUE if PT_GNU_RELRO segment should be created. */ 331 unsigned int relro: 1; 332 333 /* TRUE if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment 334 should be created. */ 335 unsigned int eh_frame_hdr: 1; 336 337 /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */ 338 unsigned int warn_shared_textrel: 1; 339 340 /* TRUE if we should error when adding a DT_TEXTREL. */ 341 unsigned int error_textrel: 1; 342 343 /* TRUE if .hash section should be created. */ 344 unsigned int emit_hash: 1; 345 346 /* TRUE if .gnu.hash section should be created. */ 347 unsigned int emit_gnu_hash: 1; 348 349 /* If TRUE reduce memory overheads, at the expense of speed. This will 350 cause map file generation to use an O(N^2) algorithm and disable 351 caching ELF symbol buffer. */ 352 unsigned int reduce_memory_overheads: 1; 353 354 /* TRUE if the output file should be in a traditional format. This 355 is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag 356 on the output file, but may be checked when reading the input 357 files. */ 358 unsigned int traditional_format: 1; 359 360 /* TRUE if non-PLT relocs should be merged into one reloc section 361 and sorted so that relocs against the same symbol come together. */ 362 unsigned int combreloc: 1; 363 364 /* TRUE if a default symbol version should be created and used for 365 imported symbols. */ 366 unsigned int default_imported_symver: 1; 367 368 /* TRUE if the new ELF dynamic tags are enabled. */ 369 unsigned int new_dtags: 1; 370 371 /* FALSE if .eh_frame unwind info should be generated for PLT and other 372 linker created sections, TRUE if it should be omitted. */ 373 unsigned int no_ld_generated_unwind_info: 1; 374 375 /* TRUE if BFD should generate a "task linked" object file, 376 similar to relocatable but also with globals converted to 377 statics. */ 378 unsigned int task_link: 1; 379 380 /* TRUE if ok to have multiple definition. */ 381 unsigned int allow_multiple_definition: 1; 382 383 /* TRUE if ok to have version with no definition. */ 384 unsigned int allow_undefined_version: 1; 385 386 /* TRUE if some symbols have to be dynamic, controlled by 387 --dynamic-list command line options. */ 388 unsigned int dynamic: 1; 389 390 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X 391 flags. */ 392 unsigned int execstack: 1; 393 394 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W 395 flags. */ 396 unsigned int noexecstack: 1; 397 398 /* TRUE if we want to produced optimized output files. This might 399 need much more time and therefore must be explicitly selected. */ 400 unsigned int optimize: 1; 401 402 /* TRUE if user should be informed of removed unreferenced sections. */ 403 unsigned int print_gc_sections: 1; 404 405 /* TRUE if we should warn alternate ELF machine code. */ 406 unsigned int warn_alternate_em: 1; 407 408 /* TRUE if the linker script contained an explicit PHDRS command. */ 409 unsigned int user_phdrs: 1; 410 411 /* Char that may appear as the first char of a symbol, but should be 412 skipped (like symbol_leading_char) when looking up symbols in 413 wrap_hash. Used by PowerPC Linux for 'dot' symbols. */ 414 char wrap_char; 415 416 /* Separator between archive and filename in linker script filespecs. */ 417 char path_separator; 418 419 /* Default stack size. Zero means default (often zero itself), -1 420 means explicitly zero-sized. */ 421 bfd_signed_vma stacksize; 422 423 /* Enable or disable target specific optimizations. 424 425 Not all targets have optimizations to enable. 426 427 Normally these optimizations are disabled by default but some targets 428 prefer to enable them by default. So this field is a tri-state variable. 429 The values are: 430 431 zero: Enable the optimizations (either from --relax being specified on 432 the command line or the backend's before_allocation emulation function. 433 434 positive: The user has requested that these optimizations be disabled. 435 (Via the --no-relax command line option). 436 437 negative: The optimizations are disabled. (Set when initializing the 438 args_type structure in ldmain.c:main. */ 439 signed int disable_target_specific_optimizations; 440 441 /* Function callbacks. */ 442 const struct bfd_link_callbacks *callbacks; 443 444 /* Hash table handled by BFD. */ 445 struct bfd_link_hash_table *hash; 446 447 /* Hash table of symbols to keep. This is NULL unless strip is 448 strip_some. */ 449 struct bfd_hash_table *keep_hash; 450 451 /* Hash table of symbols to report back via the notice callback. If 452 this is NULL, and notice_all is FALSE, then no symbols are 453 reported back. */ 454 struct bfd_hash_table *notice_hash; 455 456 /* Hash table of symbols which are being wrapped (the --wrap linker 457 option). If this is NULL, no symbols are being wrapped. */ 458 struct bfd_hash_table *wrap_hash; 459 460 /* Hash table of symbols which may be left unresolved during 461 a link. If this is NULL, no symbols can be left unresolved. */ 462 struct bfd_hash_table *ignore_hash; 463 464 /* The output BFD. */ 465 bfd *output_bfd; 466 467 /* The list of input BFD's involved in the link. These are chained 468 together via the link_next field. */ 469 bfd *input_bfds; 470 bfd **input_bfds_tail; 471 472 /* If a symbol should be created for each input BFD, this is section 473 where those symbols should be placed. It must be a section in 474 the output BFD. It may be NULL, in which case no such symbols 475 will be created. This is to support CREATE_OBJECT_SYMBOLS in the 476 linker command language. */ 477 asection *create_object_symbols_section; 478 479 /* List of global symbol names that are starting points for marking 480 sections against garbage collection. */ 481 struct bfd_sym_chain *gc_sym_list; 482 483 /* If a base output file is wanted, then this points to it */ 484 void *base_file; 485 486 /* The function to call when the executable or shared object is 487 loaded. */ 488 const char *init_function; 489 490 /* The function to call when the executable or shared object is 491 unloaded. */ 492 const char *fini_function; 493 494 /* Number of relaxation passes. Usually only one relaxation pass 495 is needed. But a backend can have as many relaxation passes as 496 necessary. During bfd_relax_section call, it is set to the 497 current pass, starting from 0. */ 498 int relax_pass; 499 500 /* Number of relaxation trips. This number is incremented every 501 time the relaxation pass is restarted due to a previous 502 relaxation returning true in *AGAIN. */ 503 int relax_trip; 504 505 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs 506 should be generated/linked against. Set to 1 if this feature 507 is explicitly requested by the user, -1 if enabled by default. */ 508 int pei386_auto_import; 509 510 /* Non-zero if runtime relocs for DATA items with non-zero addends 511 in pei386 DLLs should be generated. Set to 1 if this feature 512 is explicitly requested by the user, -1 if enabled by default. */ 513 int pei386_runtime_pseudo_reloc; 514 515 /* How many spare .dynamic DT_NULL entries should be added? */ 516 unsigned int spare_dynamic_tags; 517 518 /* May be used to set DT_FLAGS for ELF. */ 519 bfd_vma flags; 520 521 /* May be used to set DT_FLAGS_1 for ELF. */ 522 bfd_vma flags_1; 523 524 /* Start and end of RELRO region. */ 525 bfd_vma relro_start, relro_end; 526 527 /* List of symbols should be dynamic. */ 528 struct bfd_elf_dynamic_list *dynamic_list; 529 530 /* The version information. */ 531 struct bfd_elf_version_tree *version_info; 532 }; 533 534 /* This structures holds a set of callback functions. These are called 535 by the BFD linker routines. Except for the info functions, the first 536 argument to each callback function is the bfd_link_info structure 537 being used and each function returns a boolean value. If the 538 function returns FALSE, then the BFD function which called it should 539 return with a failure indication. */ 540 541 struct bfd_link_callbacks 542 { 543 /* A function which is called when an object is added from an 544 archive. ABFD is the archive element being added. NAME is the 545 name of the symbol which caused the archive element to be pulled 546 in. This function may set *SUBSBFD to point to an alternative 547 BFD from which symbols should in fact be added in place of the 548 original BFD's symbols. */ 549 bfd_boolean (*add_archive_element) 550 (struct bfd_link_info *, bfd *abfd, const char *name, bfd **subsbfd); 551 /* A function which is called when a symbol is found with multiple 552 definitions. H is the symbol which is defined multiple times. 553 NBFD is the new BFD, NSEC is the new section, and NVAL is the new 554 value. NSEC may be bfd_com_section or bfd_ind_section. */ 555 bfd_boolean (*multiple_definition) 556 (struct bfd_link_info *, struct bfd_link_hash_entry *h, 557 bfd *nbfd, asection *nsec, bfd_vma nval); 558 /* A function which is called when a common symbol is defined 559 multiple times. H is the symbol appearing multiple times. 560 NBFD is the BFD of the new symbol. NTYPE is the type of the new 561 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or 562 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE 563 is the size of the new symbol. */ 564 bfd_boolean (*multiple_common) 565 (struct bfd_link_info *, struct bfd_link_hash_entry *h, 566 bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize); 567 /* A function which is called to add a symbol to a set. ENTRY is 568 the link hash table entry for the set itself (e.g., 569 __CTOR_LIST__). RELOC is the relocation to use for an entry in 570 the set when generating a relocatable file, and is also used to 571 get the size of the entry when generating an executable file. 572 ABFD, SEC and VALUE identify the value to add to the set. */ 573 bfd_boolean (*add_to_set) 574 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 575 bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value); 576 /* A function which is called when the name of a g++ constructor or 577 destructor is found. This is only called by some object file 578 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a 579 destructor. This will use BFD_RELOC_CTOR when generating a 580 relocatable file. NAME is the name of the symbol found. ABFD, 581 SECTION and VALUE are the value of the symbol. */ 582 bfd_boolean (*constructor) 583 (struct bfd_link_info *, bfd_boolean constructor, const char *name, 584 bfd *abfd, asection *sec, bfd_vma value); 585 /* A function which is called to issue a linker warning. For 586 example, this is called when there is a reference to a warning 587 symbol. WARNING is the warning to be issued. SYMBOL is the name 588 of the symbol which triggered the warning; it may be NULL if 589 there is none. ABFD, SECTION and ADDRESS identify the location 590 which trigerred the warning; either ABFD or SECTION or both may 591 be NULL if the location is not known. */ 592 bfd_boolean (*warning) 593 (struct bfd_link_info *, const char *warning, const char *symbol, 594 bfd *abfd, asection *section, bfd_vma address); 595 /* A function which is called when a relocation is attempted against 596 an undefined symbol. NAME is the symbol which is undefined. 597 ABFD, SECTION and ADDRESS identify the location from which the 598 reference is made. IS_FATAL indicates whether an undefined symbol is 599 a fatal error or not. In some cases SECTION may be NULL. */ 600 bfd_boolean (*undefined_symbol) 601 (struct bfd_link_info *, const char *name, bfd *abfd, 602 asection *section, bfd_vma address, bfd_boolean is_fatal); 603 /* A function which is called when a reloc overflow occurs. ENTRY is 604 the link hash table entry for the symbol the reloc is against. 605 NAME is the name of the local symbol or section the reloc is 606 against, RELOC_NAME is the name of the relocation, and ADDEND is 607 any addend that is used. ABFD, SECTION and ADDRESS identify the 608 location at which the overflow occurs; if this is the result of a 609 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 610 ABFD will be NULL. */ 611 bfd_boolean (*reloc_overflow) 612 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 613 const char *name, const char *reloc_name, bfd_vma addend, 614 bfd *abfd, asection *section, bfd_vma address); 615 /* A function which is called when a dangerous reloc is performed. 616 MESSAGE is an appropriate message. 617 ABFD, SECTION and ADDRESS identify the location at which the 618 problem occurred; if this is the result of a 619 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 620 ABFD will be NULL. */ 621 bfd_boolean (*reloc_dangerous) 622 (struct bfd_link_info *, const char *message, 623 bfd *abfd, asection *section, bfd_vma address); 624 /* A function which is called when a reloc is found to be attached 625 to a symbol which is not being written out. NAME is the name of 626 the symbol. ABFD, SECTION and ADDRESS identify the location of 627 the reloc; if this is the result of a 628 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 629 ABFD will be NULL. */ 630 bfd_boolean (*unattached_reloc) 631 (struct bfd_link_info *, const char *name, 632 bfd *abfd, asection *section, bfd_vma address); 633 /* A function which is called when a symbol in notice_hash is 634 defined or referenced. H is the symbol. ABFD, SECTION and 635 ADDRESS are the (new) value of the symbol. If SECTION is 636 bfd_und_section, this is a reference. FLAGS are the symbol 637 BSF_* flags. STRING is the name of the symbol to indirect to if 638 the sym is indirect, or the warning string if a warning sym. */ 639 bfd_boolean (*notice) 640 (struct bfd_link_info *, struct bfd_link_hash_entry *h, 641 bfd *abfd, asection *section, bfd_vma address, flagword flags, 642 const char *string); 643 /* Error or warning link info message. */ 644 void (*einfo) 645 (const char *fmt, ...); 646 /* General link info message. */ 647 void (*info) 648 (const char *fmt, ...); 649 /* Message to be printed in linker map file. */ 650 void (*minfo) 651 (const char *fmt, ...); 652 /* This callback provides a chance for users of the BFD library to 653 override its decision about whether to place two adjacent sections 654 into the same segment. */ 655 bfd_boolean (*override_segment_assignment) 656 (struct bfd_link_info *, bfd * abfd, 657 asection * current_section, asection * previous_section, 658 bfd_boolean new_segment); 659 }; 660 661 /* The linker builds link_order structures which tell the code how to 662 include input data in the output file. */ 663 664 /* These are the types of link_order structures. */ 665 666 enum bfd_link_order_type 667 { 668 bfd_undefined_link_order, /* Undefined. */ 669 bfd_indirect_link_order, /* Built from a section. */ 670 bfd_data_link_order, /* Set to explicit data. */ 671 bfd_section_reloc_link_order, /* Relocate against a section. */ 672 bfd_symbol_reloc_link_order /* Relocate against a symbol. */ 673 }; 674 675 /* This is the link_order structure itself. These form a chain 676 attached to the output section whose contents they are describing. */ 677 678 struct bfd_link_order 679 { 680 /* Next link_order in chain. */ 681 struct bfd_link_order *next; 682 /* Type of link_order. */ 683 enum bfd_link_order_type type; 684 /* Offset within output section. */ 685 bfd_vma offset; 686 /* Size within output section. */ 687 bfd_size_type size; 688 /* Type specific information. */ 689 union 690 { 691 struct 692 { 693 /* Section to include. If this is used, then 694 section->output_section must be the section the 695 link_order is attached to, section->output_offset must 696 equal the link_order offset field, and section->size 697 must equal the link_order size field. Maybe these 698 restrictions should be relaxed someday. */ 699 asection *section; 700 } indirect; 701 struct 702 { 703 /* Size of contents, or zero when contents should be filled by 704 the architecture-dependent fill function. 705 A non-zero value allows filling of the output section 706 with an arbitrary repeated pattern. */ 707 unsigned int size; 708 /* Data to put into file. */ 709 bfd_byte *contents; 710 } data; 711 struct 712 { 713 /* Description of reloc to generate. Used for 714 bfd_section_reloc_link_order and 715 bfd_symbol_reloc_link_order. */ 716 struct bfd_link_order_reloc *p; 717 } reloc; 718 } u; 719 }; 720 721 /* A linker order of type bfd_section_reloc_link_order or 722 bfd_symbol_reloc_link_order means to create a reloc against a 723 section or symbol, respectively. This is used to implement -Ur to 724 generate relocs for the constructor tables. The 725 bfd_link_order_reloc structure describes the reloc that BFD should 726 create. It is similar to a arelent, but I didn't use arelent 727 because the linker does not know anything about most symbols, and 728 any asymbol structure it creates will be partially meaningless. 729 This information could logically be in the bfd_link_order struct, 730 but I didn't want to waste the space since these types of relocs 731 are relatively rare. */ 732 733 struct bfd_link_order_reloc 734 { 735 /* Reloc type. */ 736 bfd_reloc_code_real_type reloc; 737 738 union 739 { 740 /* For type bfd_section_reloc_link_order, this is the section 741 the reloc should be against. This must be a section in the 742 output BFD, not any of the input BFDs. */ 743 asection *section; 744 /* For type bfd_symbol_reloc_link_order, this is the name of the 745 symbol the reloc should be against. */ 746 const char *name; 747 } u; 748 749 /* Addend to use. The object file should contain zero. The BFD 750 backend is responsible for filling in the contents of the object 751 file correctly. For some object file formats (e.g., COFF) the 752 addend must be stored into in the object file, and for some 753 (e.g., SPARC a.out) it is kept in the reloc. */ 754 bfd_vma addend; 755 }; 756 757 /* Allocate a new link_order for a section. */ 758 extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *); 759 760 /* These structures are used to describe version information for the 761 ELF linker. These structures could be manipulated entirely inside 762 BFD, but it would be a pain. Instead, the regular linker sets up 763 these structures, and then passes them into BFD. */ 764 765 /* Glob pattern for a version. */ 766 767 struct bfd_elf_version_expr 768 { 769 /* Next glob pattern for this version. */ 770 struct bfd_elf_version_expr *next; 771 /* Glob pattern. */ 772 const char *pattern; 773 /* Set if pattern is not a glob. */ 774 unsigned int literal : 1; 775 /* Defined by ".symver". */ 776 unsigned int symver : 1; 777 /* Defined by version script. */ 778 unsigned int script : 1; 779 /* Pattern type. */ 780 #define BFD_ELF_VERSION_C_TYPE 1 781 #define BFD_ELF_VERSION_CXX_TYPE 2 782 #define BFD_ELF_VERSION_JAVA_TYPE 4 783 unsigned int mask : 3; 784 }; 785 786 struct bfd_elf_version_expr_head 787 { 788 /* List of all patterns, both wildcards and non-wildcards. */ 789 struct bfd_elf_version_expr *list; 790 /* Hash table for non-wildcards. */ 791 void *htab; 792 /* Remaining patterns. */ 793 struct bfd_elf_version_expr *remaining; 794 /* What kind of pattern types are present in list (bitmask). */ 795 unsigned int mask; 796 }; 797 798 /* Version dependencies. */ 799 800 struct bfd_elf_version_deps 801 { 802 /* Next dependency for this version. */ 803 struct bfd_elf_version_deps *next; 804 /* The version which this version depends upon. */ 805 struct bfd_elf_version_tree *version_needed; 806 }; 807 808 /* A node in the version tree. */ 809 810 struct bfd_elf_version_tree 811 { 812 /* Next version. */ 813 struct bfd_elf_version_tree *next; 814 /* Name of this version. */ 815 const char *name; 816 /* Version number. */ 817 unsigned int vernum; 818 /* Regular expressions for global symbols in this version. */ 819 struct bfd_elf_version_expr_head globals; 820 /* Regular expressions for local symbols in this version. */ 821 struct bfd_elf_version_expr_head locals; 822 /* List of versions which this version depends upon. */ 823 struct bfd_elf_version_deps *deps; 824 /* Index of the version name. This is used within BFD. */ 825 unsigned int name_indx; 826 /* Whether this version tree was used. This is used within BFD. */ 827 int used; 828 /* Matching hook. */ 829 struct bfd_elf_version_expr *(*match) 830 (struct bfd_elf_version_expr_head *head, 831 struct bfd_elf_version_expr *prev, const char *sym); 832 }; 833 834 struct bfd_elf_dynamic_list 835 { 836 struct bfd_elf_version_expr_head head; 837 struct bfd_elf_version_expr *(*match) 838 (struct bfd_elf_version_expr_head *head, 839 struct bfd_elf_version_expr *prev, const char *sym); 840 }; 841 842 #endif 843