1 /* bfdlink.h -- header file for BFD link routines 2 Copyright (C) 1993-2014 Free Software Foundation, Inc. 3 Written by Steve Chamberlain and Ian Lance Taylor, Cygnus Support. 4 5 This file is part of BFD, the Binary File Descriptor library. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program; if not, write to the Free Software 19 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 20 MA 02110-1301, USA. */ 21 22 #ifndef BFDLINK_H 23 #define BFDLINK_H 24 25 /* Which symbols to strip during a link. */ 26 enum bfd_link_strip 27 { 28 strip_none, /* Don't strip any symbols. */ 29 strip_debugger, /* Strip debugging symbols. */ 30 strip_some, /* keep_hash is the list of symbols to keep. */ 31 strip_all /* Strip all symbols. */ 32 }; 33 34 /* Which local symbols to discard during a link. This is irrelevant 35 if strip_all is used. */ 36 enum bfd_link_discard 37 { 38 discard_sec_merge, /* Discard local temporary symbols in SEC_MERGE 39 sections. */ 40 discard_none, /* Don't discard any locals. */ 41 discard_l, /* Discard local temporary symbols. */ 42 discard_all /* Discard all locals. */ 43 }; 44 45 /* Describes the type of hash table entry structure being used. 46 Different hash table structure have different fields and so 47 support different linking features. */ 48 enum bfd_link_hash_table_type 49 { 50 bfd_link_generic_hash_table, 51 bfd_link_elf_hash_table 52 }; 53 54 /* These are the possible types of an entry in the BFD link hash 55 table. */ 56 57 enum bfd_link_hash_type 58 { 59 bfd_link_hash_new, /* Symbol is new. */ 60 bfd_link_hash_undefined, /* Symbol seen before, but undefined. */ 61 bfd_link_hash_undefweak, /* Symbol is weak and undefined. */ 62 bfd_link_hash_defined, /* Symbol is defined. */ 63 bfd_link_hash_defweak, /* Symbol is weak and defined. */ 64 bfd_link_hash_common, /* Symbol is common. */ 65 bfd_link_hash_indirect, /* Symbol is an indirect link. */ 66 bfd_link_hash_warning /* Like indirect, but warn if referenced. */ 67 }; 68 69 enum bfd_link_common_skip_ar_symbols 70 { 71 bfd_link_common_skip_none, 72 bfd_link_common_skip_text, 73 bfd_link_common_skip_data, 74 bfd_link_common_skip_all 75 }; 76 77 struct bfd_link_hash_common_entry 78 { 79 unsigned int alignment_power; /* Alignment. */ 80 asection *section; /* Symbol section. */ 81 }; 82 83 /* The linking routines use a hash table which uses this structure for 84 its elements. */ 85 86 struct bfd_link_hash_entry 87 { 88 /* Base hash table entry structure. */ 89 struct bfd_hash_entry root; 90 91 /* Type of this entry. */ 92 ENUM_BITFIELD (bfd_link_hash_type) type : 8; 93 94 unsigned int non_ir_ref : 1; 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 } 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 /* Function to free the hash table on closing BFD. */ 171 void (*hash_table_free) (bfd *); 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 /* If H is a wrapped symbol, ie. the symbol name starts with "__wrap_" 192 and the remainder is found in wrap_hash, return the real symbol. */ 193 194 extern struct bfd_link_hash_entry *unwrap_hash_lookup 195 (struct bfd_link_info *, bfd *, struct bfd_link_hash_entry *); 196 197 /* Traverse a link hash table. */ 198 extern void bfd_link_hash_traverse 199 (struct bfd_link_hash_table *, 200 bfd_boolean (*) (struct bfd_link_hash_entry *, void *), 201 void *); 202 203 /* Add an entry to the undefs list. */ 204 extern void bfd_link_add_undef 205 (struct bfd_link_hash_table *, struct bfd_link_hash_entry *); 206 207 /* Remove symbols from the undefs list that don't belong there. */ 208 extern void bfd_link_repair_undef_list 209 (struct bfd_link_hash_table *table); 210 211 /* Read symbols and cache symbol pointer array in outsymbols. */ 212 extern bfd_boolean bfd_generic_link_read_symbols (bfd *); 213 214 struct bfd_sym_chain 215 { 216 struct bfd_sym_chain *next; 217 const char *name; 218 }; 219 220 /* How to handle unresolved symbols. 221 There are four possibilities which are enumerated below: */ 222 enum report_method 223 { 224 /* This is the initial value when then link_info structure is created. 225 It allows the various stages of the linker to determine whether they 226 allowed to set the value. */ 227 RM_NOT_YET_SET = 0, 228 RM_IGNORE, 229 RM_GENERATE_WARNING, 230 RM_GENERATE_ERROR 231 }; 232 233 typedef enum {with_flags, without_flags} flag_type; 234 235 /* A section flag list. */ 236 struct flag_info_list 237 { 238 flag_type with; 239 const char *name; 240 bfd_boolean valid; 241 struct flag_info_list *next; 242 }; 243 244 /* Section flag info. */ 245 struct flag_info 246 { 247 flagword only_with_flags; 248 flagword not_with_flags; 249 struct flag_info_list *flag_list; 250 bfd_boolean flags_initialized; 251 }; 252 253 struct bfd_elf_dynamic_list; 254 struct bfd_elf_version_tree; 255 256 /* This structure holds all the information needed to communicate 257 between BFD and the linker when doing a link. */ 258 259 struct bfd_link_info 260 { 261 /* TRUE if BFD should generate a shared object (or a pie). */ 262 unsigned int shared: 1; 263 264 /* TRUE if generating an executable, position independent or not. */ 265 unsigned int executable : 1; 266 267 /* TRUE if generating a position independent executable. */ 268 unsigned int pie: 1; 269 270 /* TRUE if BFD should generate a relocatable object file. */ 271 unsigned int relocatable: 1; 272 273 /* TRUE if BFD should pre-bind symbols in a shared object. */ 274 unsigned int symbolic: 1; 275 276 /* TRUE if executable should not contain copy relocs. 277 Setting this true may result in a non-sharable text segment. */ 278 unsigned int nocopyreloc: 1; 279 280 /* TRUE if BFD should export all symbols in the dynamic symbol table 281 of an executable, rather than only those used. */ 282 unsigned int export_dynamic: 1; 283 284 /* TRUE if a default symbol version should be created and used for 285 exported symbols. */ 286 unsigned int create_default_symver: 1; 287 288 /* TRUE if unreferenced sections should be removed. */ 289 unsigned int gc_sections: 1; 290 291 /* TRUE if every symbol should be reported back via the notice 292 callback. */ 293 unsigned int notice_all: 1; 294 295 /* TRUE if the LTO plugin is active. */ 296 unsigned int lto_plugin_active: 1; 297 298 /* TRUE if we are loading LTO outputs. */ 299 unsigned int loading_lto_outputs: 1; 300 301 /* TRUE if global symbols in discarded sections should be stripped. */ 302 unsigned int strip_discarded: 1; 303 304 /* TRUE if all data symbols should be dynamic. */ 305 unsigned int dynamic_data: 1; 306 307 /* Which symbols to strip. */ 308 ENUM_BITFIELD (bfd_link_strip) strip : 2; 309 310 /* Which local symbols to discard. */ 311 ENUM_BITFIELD (bfd_link_discard) discard : 2; 312 313 /* Criteria for skipping symbols when determining 314 whether to include an object from an archive. */ 315 ENUM_BITFIELD (bfd_link_common_skip_ar_symbols) common_skip_ar_symbols : 2; 316 317 /* What to do with unresolved symbols in an object file. 318 When producing executables the default is GENERATE_ERROR. 319 When producing shared libraries the default is IGNORE. The 320 assumption with shared libraries is that the reference will be 321 resolved at load/execution time. */ 322 ENUM_BITFIELD (report_method) unresolved_syms_in_objects : 2; 323 324 /* What to do with unresolved symbols in a shared library. 325 The same defaults apply. */ 326 ENUM_BITFIELD (report_method) unresolved_syms_in_shared_libs : 2; 327 328 /* TRUE if shared objects should be linked directly, not shared. */ 329 unsigned int static_link: 1; 330 331 /* TRUE if symbols should be retained in memory, FALSE if they 332 should be freed and reread. */ 333 unsigned int keep_memory: 1; 334 335 /* TRUE if BFD should generate relocation information in the final 336 executable. */ 337 unsigned int emitrelocations: 1; 338 339 /* TRUE if PT_GNU_RELRO segment should be created. */ 340 unsigned int relro: 1; 341 342 /* TRUE if .eh_frame_hdr section and PT_GNU_EH_FRAME ELF segment 343 should be created. */ 344 unsigned int eh_frame_hdr: 1; 345 346 /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */ 347 unsigned int warn_shared_textrel: 1; 348 349 /* TRUE if we should error when adding a DT_TEXTREL. */ 350 unsigned int error_textrel: 1; 351 352 /* TRUE if .hash section should be created. */ 353 unsigned int emit_hash: 1; 354 355 /* TRUE if .gnu.hash section should be created. */ 356 unsigned int emit_gnu_hash: 1; 357 358 /* If TRUE reduce memory overheads, at the expense of speed. This will 359 cause map file generation to use an O(N^2) algorithm and disable 360 caching ELF symbol buffer. */ 361 unsigned int reduce_memory_overheads: 1; 362 363 /* TRUE if the output file should be in a traditional format. This 364 is equivalent to the setting of the BFD_TRADITIONAL_FORMAT flag 365 on the output file, but may be checked when reading the input 366 files. */ 367 unsigned int traditional_format: 1; 368 369 /* TRUE if non-PLT relocs should be merged into one reloc section 370 and sorted so that relocs against the same symbol come together. */ 371 unsigned int combreloc: 1; 372 373 /* TRUE if a default symbol version should be created and used for 374 imported symbols. */ 375 unsigned int default_imported_symver: 1; 376 377 /* TRUE if the new ELF dynamic tags are enabled. */ 378 unsigned int new_dtags: 1; 379 380 /* FALSE if .eh_frame unwind info should be generated for PLT and other 381 linker created sections, TRUE if it should be omitted. */ 382 unsigned int no_ld_generated_unwind_info: 1; 383 384 /* TRUE if BFD should generate a "task linked" object file, 385 similar to relocatable but also with globals converted to 386 statics. */ 387 unsigned int task_link: 1; 388 389 /* TRUE if ok to have multiple definition. */ 390 unsigned int allow_multiple_definition: 1; 391 392 /* TRUE if ok to have version with no definition. */ 393 unsigned int allow_undefined_version: 1; 394 395 /* TRUE if some symbols have to be dynamic, controlled by 396 --dynamic-list command line options. */ 397 unsigned int dynamic: 1; 398 399 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W|PF_X 400 flags. */ 401 unsigned int execstack: 1; 402 403 /* TRUE if PT_GNU_STACK segment should be created with PF_R|PF_W 404 flags. */ 405 unsigned int noexecstack: 1; 406 407 /* TRUE if we want to produced optimized output files. This might 408 need much more time and therefore must be explicitly selected. */ 409 unsigned int optimize: 1; 410 411 /* TRUE if user should be informed of removed unreferenced sections. */ 412 unsigned int print_gc_sections: 1; 413 414 /* TRUE if we should warn alternate ELF machine code. */ 415 unsigned int warn_alternate_em: 1; 416 417 /* TRUE if the linker script contained an explicit PHDRS command. */ 418 unsigned int user_phdrs: 1; 419 420 /* Char that may appear as the first char of a symbol, but should be 421 skipped (like symbol_leading_char) when looking up symbols in 422 wrap_hash. Used by PowerPC Linux for 'dot' symbols. */ 423 char wrap_char; 424 425 /* Separator between archive and filename in linker script filespecs. */ 426 char path_separator; 427 428 /* Default stack size. Zero means default (often zero itself), -1 429 means explicitly zero-sized. */ 430 bfd_signed_vma stacksize; 431 432 /* Enable or disable target specific optimizations. 433 434 Not all targets have optimizations to enable. 435 436 Normally these optimizations are disabled by default but some targets 437 prefer to enable them by default. So this field is a tri-state variable. 438 The values are: 439 440 zero: Enable the optimizations (either from --relax being specified on 441 the command line or the backend's before_allocation emulation function. 442 443 positive: The user has requested that these optimizations be disabled. 444 (Via the --no-relax command line option). 445 446 negative: The optimizations are disabled. (Set when initializing the 447 args_type structure in ldmain.c:main. */ 448 signed int disable_target_specific_optimizations; 449 450 /* Function callbacks. */ 451 const struct bfd_link_callbacks *callbacks; 452 453 /* Hash table handled by BFD. */ 454 struct bfd_link_hash_table *hash; 455 456 /* Hash table of symbols to keep. This is NULL unless strip is 457 strip_some. */ 458 struct bfd_hash_table *keep_hash; 459 460 /* Hash table of symbols to report back via the notice callback. If 461 this is NULL, and notice_all is FALSE, then no symbols are 462 reported back. */ 463 struct bfd_hash_table *notice_hash; 464 465 /* Hash table of symbols which are being wrapped (the --wrap linker 466 option). If this is NULL, no symbols are being wrapped. */ 467 struct bfd_hash_table *wrap_hash; 468 469 /* Hash table of symbols which may be left unresolved during 470 a link. If this is NULL, no symbols can be left unresolved. */ 471 struct bfd_hash_table *ignore_hash; 472 473 /* The output BFD. */ 474 bfd *output_bfd; 475 476 /* The list of input BFD's involved in the link. These are chained 477 together via the link.next field. */ 478 bfd *input_bfds; 479 bfd **input_bfds_tail; 480 481 /* If a symbol should be created for each input BFD, this is section 482 where those symbols should be placed. It must be a section in 483 the output BFD. It may be NULL, in which case no such symbols 484 will be created. This is to support CREATE_OBJECT_SYMBOLS in the 485 linker command language. */ 486 asection *create_object_symbols_section; 487 488 /* List of global symbol names that are starting points for marking 489 sections against garbage collection. */ 490 struct bfd_sym_chain *gc_sym_list; 491 492 /* If a base output file is wanted, then this points to it */ 493 void *base_file; 494 495 /* The function to call when the executable or shared object is 496 loaded. */ 497 const char *init_function; 498 499 /* The function to call when the executable or shared object is 500 unloaded. */ 501 const char *fini_function; 502 503 /* Number of relaxation passes. Usually only one relaxation pass 504 is needed. But a backend can have as many relaxation passes as 505 necessary. During bfd_relax_section call, it is set to the 506 current pass, starting from 0. */ 507 int relax_pass; 508 509 /* Number of relaxation trips. This number is incremented every 510 time the relaxation pass is restarted due to a previous 511 relaxation returning true in *AGAIN. */ 512 int relax_trip; 513 514 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs 515 should be generated/linked against. Set to 1 if this feature 516 is explicitly requested by the user, -1 if enabled by default. */ 517 int pei386_auto_import; 518 519 /* Non-zero if runtime relocs for DATA items with non-zero addends 520 in pei386 DLLs should be generated. Set to 1 if this feature 521 is explicitly requested by the user, -1 if enabled by default. */ 522 int pei386_runtime_pseudo_reloc; 523 524 /* How many spare .dynamic DT_NULL entries should be added? */ 525 unsigned int spare_dynamic_tags; 526 527 /* May be used to set DT_FLAGS for ELF. */ 528 bfd_vma flags; 529 530 /* May be used to set DT_FLAGS_1 for ELF. */ 531 bfd_vma flags_1; 532 533 /* Start and end of RELRO region. */ 534 bfd_vma relro_start, relro_end; 535 536 /* List of symbols should be dynamic. */ 537 struct bfd_elf_dynamic_list *dynamic_list; 538 539 /* The version information. */ 540 struct bfd_elf_version_tree *version_info; 541 }; 542 543 /* This structures holds a set of callback functions. These are called 544 by the BFD linker routines. Except for the info functions, the first 545 argument to each callback function is the bfd_link_info structure 546 being used and each function returns a boolean value. If the 547 function returns FALSE, then the BFD function which called it should 548 return with a failure indication. */ 549 550 struct bfd_link_callbacks 551 { 552 /* A function which is called when an object is added from an 553 archive. ABFD is the archive element being added. NAME is the 554 name of the symbol which caused the archive element to be pulled 555 in. This function may set *SUBSBFD to point to an alternative 556 BFD from which symbols should in fact be added in place of the 557 original BFD's symbols. */ 558 bfd_boolean (*add_archive_element) 559 (struct bfd_link_info *, bfd *abfd, const char *name, bfd **subsbfd); 560 /* A function which is called when a symbol is found with multiple 561 definitions. H is the symbol which is defined multiple times. 562 NBFD is the new BFD, NSEC is the new section, and NVAL is the new 563 value. NSEC may be bfd_com_section or bfd_ind_section. */ 564 bfd_boolean (*multiple_definition) 565 (struct bfd_link_info *, struct bfd_link_hash_entry *h, 566 bfd *nbfd, asection *nsec, bfd_vma nval); 567 /* A function which is called when a common symbol is defined 568 multiple times. H is the symbol appearing multiple times. 569 NBFD is the BFD of the new symbol. NTYPE is the type of the new 570 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or 571 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE 572 is the size of the new symbol. */ 573 bfd_boolean (*multiple_common) 574 (struct bfd_link_info *, struct bfd_link_hash_entry *h, 575 bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize); 576 /* A function which is called to add a symbol to a set. ENTRY is 577 the link hash table entry for the set itself (e.g., 578 __CTOR_LIST__). RELOC is the relocation to use for an entry in 579 the set when generating a relocatable file, and is also used to 580 get the size of the entry when generating an executable file. 581 ABFD, SEC and VALUE identify the value to add to the set. */ 582 bfd_boolean (*add_to_set) 583 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 584 bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value); 585 /* A function which is called when the name of a g++ constructor or 586 destructor is found. This is only called by some object file 587 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a 588 destructor. This will use BFD_RELOC_CTOR when generating a 589 relocatable file. NAME is the name of the symbol found. ABFD, 590 SECTION and VALUE are the value of the symbol. */ 591 bfd_boolean (*constructor) 592 (struct bfd_link_info *, bfd_boolean constructor, const char *name, 593 bfd *abfd, asection *sec, bfd_vma value); 594 /* A function which is called to issue a linker warning. For 595 example, this is called when there is a reference to a warning 596 symbol. WARNING is the warning to be issued. SYMBOL is the name 597 of the symbol which triggered the warning; it may be NULL if 598 there is none. ABFD, SECTION and ADDRESS identify the location 599 which trigerred the warning; either ABFD or SECTION or both may 600 be NULL if the location is not known. */ 601 bfd_boolean (*warning) 602 (struct bfd_link_info *, const char *warning, const char *symbol, 603 bfd *abfd, asection *section, bfd_vma address); 604 /* A function which is called when a relocation is attempted against 605 an undefined symbol. NAME is the symbol which is undefined. 606 ABFD, SECTION and ADDRESS identify the location from which the 607 reference is made. IS_FATAL indicates whether an undefined symbol is 608 a fatal error or not. In some cases SECTION may be NULL. */ 609 bfd_boolean (*undefined_symbol) 610 (struct bfd_link_info *, const char *name, bfd *abfd, 611 asection *section, bfd_vma address, bfd_boolean is_fatal); 612 /* A function which is called when a reloc overflow occurs. ENTRY is 613 the link hash table entry for the symbol the reloc is against. 614 NAME is the name of the local symbol or section the reloc is 615 against, RELOC_NAME is the name of the relocation, and ADDEND is 616 any addend that is used. ABFD, SECTION and ADDRESS identify the 617 location at which the overflow occurs; if this is the result of a 618 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 619 ABFD will be NULL. */ 620 bfd_boolean (*reloc_overflow) 621 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 622 const char *name, const char *reloc_name, bfd_vma addend, 623 bfd *abfd, asection *section, bfd_vma address); 624 /* A function which is called when a dangerous reloc is performed. 625 MESSAGE is an appropriate message. 626 ABFD, SECTION and ADDRESS identify the location at which the 627 problem occurred; 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 (*reloc_dangerous) 631 (struct bfd_link_info *, const char *message, 632 bfd *abfd, asection *section, bfd_vma address); 633 /* A function which is called when a reloc is found to be attached 634 to a symbol which is not being written out. NAME is the name of 635 the symbol. ABFD, SECTION and ADDRESS identify the location of 636 the reloc; if this is the result of a 637 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 638 ABFD will be NULL. */ 639 bfd_boolean (*unattached_reloc) 640 (struct bfd_link_info *, const char *name, 641 bfd *abfd, asection *section, bfd_vma address); 642 /* A function which is called when a symbol in notice_hash is 643 defined or referenced. H is the symbol, INH the indirect symbol 644 if applicable. ABFD, SECTION and ADDRESS are the (new) value of 645 the symbol. If SECTION is bfd_und_section, this is a reference. 646 FLAGS are the symbol BSF_* flags. */ 647 bfd_boolean (*notice) 648 (struct bfd_link_info *, struct bfd_link_hash_entry *h, 649 struct bfd_link_hash_entry *inh, 650 bfd *abfd, asection *section, bfd_vma address, flagword flags); 651 /* Error or warning link info message. */ 652 void (*einfo) 653 (const char *fmt, ...); 654 /* General link info message. */ 655 void (*info) 656 (const char *fmt, ...); 657 /* Message to be printed in linker map file. */ 658 void (*minfo) 659 (const char *fmt, ...); 660 /* This callback provides a chance for users of the BFD library to 661 override its decision about whether to place two adjacent sections 662 into the same segment. */ 663 bfd_boolean (*override_segment_assignment) 664 (struct bfd_link_info *, bfd * abfd, 665 asection * current_section, asection * previous_section, 666 bfd_boolean new_segment); 667 }; 668 669 /* The linker builds link_order structures which tell the code how to 670 include input data in the output file. */ 671 672 /* These are the types of link_order structures. */ 673 674 enum bfd_link_order_type 675 { 676 bfd_undefined_link_order, /* Undefined. */ 677 bfd_indirect_link_order, /* Built from a section. */ 678 bfd_data_link_order, /* Set to explicit data. */ 679 bfd_section_reloc_link_order, /* Relocate against a section. */ 680 bfd_symbol_reloc_link_order /* Relocate against a symbol. */ 681 }; 682 683 /* This is the link_order structure itself. These form a chain 684 attached to the output section whose contents they are describing. */ 685 686 struct bfd_link_order 687 { 688 /* Next link_order in chain. */ 689 struct bfd_link_order *next; 690 /* Type of link_order. */ 691 enum bfd_link_order_type type; 692 /* Offset within output section. */ 693 bfd_vma offset; 694 /* Size within output section. */ 695 bfd_size_type size; 696 /* Type specific information. */ 697 union 698 { 699 struct 700 { 701 /* Section to include. If this is used, then 702 section->output_section must be the section the 703 link_order is attached to, section->output_offset must 704 equal the link_order offset field, and section->size 705 must equal the link_order size field. Maybe these 706 restrictions should be relaxed someday. */ 707 asection *section; 708 } indirect; 709 struct 710 { 711 /* Size of contents, or zero when contents should be filled by 712 the architecture-dependent fill function. 713 A non-zero value allows filling of the output section 714 with an arbitrary repeated pattern. */ 715 unsigned int size; 716 /* Data to put into file. */ 717 bfd_byte *contents; 718 } data; 719 struct 720 { 721 /* Description of reloc to generate. Used for 722 bfd_section_reloc_link_order and 723 bfd_symbol_reloc_link_order. */ 724 struct bfd_link_order_reloc *p; 725 } reloc; 726 } u; 727 }; 728 729 /* A linker order of type bfd_section_reloc_link_order or 730 bfd_symbol_reloc_link_order means to create a reloc against a 731 section or symbol, respectively. This is used to implement -Ur to 732 generate relocs for the constructor tables. The 733 bfd_link_order_reloc structure describes the reloc that BFD should 734 create. It is similar to a arelent, but I didn't use arelent 735 because the linker does not know anything about most symbols, and 736 any asymbol structure it creates will be partially meaningless. 737 This information could logically be in the bfd_link_order struct, 738 but I didn't want to waste the space since these types of relocs 739 are relatively rare. */ 740 741 struct bfd_link_order_reloc 742 { 743 /* Reloc type. */ 744 bfd_reloc_code_real_type reloc; 745 746 union 747 { 748 /* For type bfd_section_reloc_link_order, this is the section 749 the reloc should be against. This must be a section in the 750 output BFD, not any of the input BFDs. */ 751 asection *section; 752 /* For type bfd_symbol_reloc_link_order, this is the name of the 753 symbol the reloc should be against. */ 754 const char *name; 755 } u; 756 757 /* Addend to use. The object file should contain zero. The BFD 758 backend is responsible for filling in the contents of the object 759 file correctly. For some object file formats (e.g., COFF) the 760 addend must be stored into in the object file, and for some 761 (e.g., SPARC a.out) it is kept in the reloc. */ 762 bfd_vma addend; 763 }; 764 765 /* Allocate a new link_order for a section. */ 766 extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *); 767 768 /* These structures are used to describe version information for the 769 ELF linker. These structures could be manipulated entirely inside 770 BFD, but it would be a pain. Instead, the regular linker sets up 771 these structures, and then passes them into BFD. */ 772 773 /* Glob pattern for a version. */ 774 775 struct bfd_elf_version_expr 776 { 777 /* Next glob pattern for this version. */ 778 struct bfd_elf_version_expr *next; 779 /* Glob pattern. */ 780 const char *pattern; 781 /* Set if pattern is not a glob. */ 782 unsigned int literal : 1; 783 /* Defined by ".symver". */ 784 unsigned int symver : 1; 785 /* Defined by version script. */ 786 unsigned int script : 1; 787 /* Pattern type. */ 788 #define BFD_ELF_VERSION_C_TYPE 1 789 #define BFD_ELF_VERSION_CXX_TYPE 2 790 #define BFD_ELF_VERSION_JAVA_TYPE 4 791 unsigned int mask : 3; 792 }; 793 794 struct bfd_elf_version_expr_head 795 { 796 /* List of all patterns, both wildcards and non-wildcards. */ 797 struct bfd_elf_version_expr *list; 798 /* Hash table for non-wildcards. */ 799 void *htab; 800 /* Remaining patterns. */ 801 struct bfd_elf_version_expr *remaining; 802 /* What kind of pattern types are present in list (bitmask). */ 803 unsigned int mask; 804 }; 805 806 /* Version dependencies. */ 807 808 struct bfd_elf_version_deps 809 { 810 /* Next dependency for this version. */ 811 struct bfd_elf_version_deps *next; 812 /* The version which this version depends upon. */ 813 struct bfd_elf_version_tree *version_needed; 814 }; 815 816 /* A node in the version tree. */ 817 818 struct bfd_elf_version_tree 819 { 820 /* Next version. */ 821 struct bfd_elf_version_tree *next; 822 /* Name of this version. */ 823 const char *name; 824 /* Version number. */ 825 unsigned int vernum; 826 /* Regular expressions for global symbols in this version. */ 827 struct bfd_elf_version_expr_head globals; 828 /* Regular expressions for local symbols in this version. */ 829 struct bfd_elf_version_expr_head locals; 830 /* List of versions which this version depends upon. */ 831 struct bfd_elf_version_deps *deps; 832 /* Index of the version name. This is used within BFD. */ 833 unsigned int name_indx; 834 /* Whether this version tree was used. This is used within BFD. */ 835 int used; 836 /* Matching hook. */ 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 struct bfd_elf_dynamic_list 843 { 844 struct bfd_elf_version_expr_head head; 845 struct bfd_elf_version_expr *(*match) 846 (struct bfd_elf_version_expr_head *head, 847 struct bfd_elf_version_expr *prev, const char *sym); 848 }; 849 850 #endif 851