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. */ 28enum 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. */ 38enum 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. */ 50enum 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 59enum 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 71enum 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 79struct 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 88struct 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 163struct 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. */ 179extern 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 187extern 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. */ 192extern 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. */ 198extern 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. */ 202extern void bfd_link_repair_undef_list 203 (struct bfd_link_hash_table *table); 204 205/* Read symbols and cache symbol pointer array in outsymbols. */ 206extern bfd_boolean bfd_generic_link_read_symbols (bfd *); 207 208struct 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: */ 216enum 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 227typedef enum {with_flags, without_flags} flag_type; 228 229/* A section flag list. */ 230struct 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. */ 239struct 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 247struct bfd_elf_dynamic_list; 248struct 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 253struct 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 /* Function callbacks. */ 420 const struct bfd_link_callbacks *callbacks; 421 422 /* Hash table handled by BFD. */ 423 struct bfd_link_hash_table *hash; 424 425 /* Hash table of symbols to keep. This is NULL unless strip is 426 strip_some. */ 427 struct bfd_hash_table *keep_hash; 428 429 /* Hash table of symbols to report back via the notice callback. If 430 this is NULL, and notice_all is FALSE, then no symbols are 431 reported back. */ 432 struct bfd_hash_table *notice_hash; 433 434 /* Hash table of symbols which are being wrapped (the --wrap linker 435 option). If this is NULL, no symbols are being wrapped. */ 436 struct bfd_hash_table *wrap_hash; 437 438 /* The output BFD. */ 439 bfd *output_bfd; 440 441 /* The list of input BFD's involved in the link. These are chained 442 together via the link_next field. */ 443 bfd *input_bfds; 444 bfd **input_bfds_tail; 445 446 /* Non-NULL if .note.gnu.build-id section should be created. */ 447 char *emit_note_gnu_build_id; 448 449 /* If a symbol should be created for each input BFD, this is section 450 where those symbols should be placed. It must be a section in 451 the output BFD. It may be NULL, in which case no such symbols 452 will be created. This is to support CREATE_OBJECT_SYMBOLS in the 453 linker command language. */ 454 asection *create_object_symbols_section; 455 456 /* List of global symbol names that are starting points for marking 457 sections against garbage collection. */ 458 struct bfd_sym_chain *gc_sym_list; 459 460 /* If a base output file is wanted, then this points to it */ 461 void *base_file; 462 463 /* The function to call when the executable or shared object is 464 loaded. */ 465 const char *init_function; 466 467 /* The function to call when the executable or shared object is 468 unloaded. */ 469 const char *fini_function; 470 471 /* Number of relaxation passes. Usually only one relaxation pass 472 is needed. But a backend can have as many relaxation passes as 473 necessary. During bfd_relax_section call, it is set to the 474 current pass, starting from 0. */ 475 int relax_pass; 476 477 /* Number of relaxation trips. This number is incremented every 478 time the relaxation pass is restarted due to a previous 479 relaxation returning true in *AGAIN. */ 480 int relax_trip; 481 482 /* Non-zero if auto-import thunks for DATA items in pei386 DLLs 483 should be generated/linked against. Set to 1 if this feature 484 is explicitly requested by the user, -1 if enabled by default. */ 485 int pei386_auto_import; 486 487 /* Non-zero if runtime relocs for DATA items with non-zero addends 488 in pei386 DLLs should be generated. Set to 1 if this feature 489 is explicitly requested by the user, -1 if enabled by default. */ 490 int pei386_runtime_pseudo_reloc; 491 492 /* How many spare .dynamic DT_NULL entries should be added? */ 493 unsigned int spare_dynamic_tags; 494 495 /* May be used to set DT_FLAGS for ELF. */ 496 bfd_vma flags; 497 498 /* May be used to set DT_FLAGS_1 for ELF. */ 499 bfd_vma flags_1; 500 501 /* Start and end of RELRO region. */ 502 bfd_vma relro_start, relro_end; 503 504 /* List of symbols should be dynamic. */ 505 struct bfd_elf_dynamic_list *dynamic_list; 506 507 /* The version information. */ 508 struct bfd_elf_version_tree *version_info; 509}; 510 511/* This structures holds a set of callback functions. These are called 512 by the BFD linker routines. Except for the info functions, the first 513 argument to each callback function is the bfd_link_info structure 514 being used and each function returns a boolean value. If the 515 function returns FALSE, then the BFD function which called it should 516 return with a failure indication. */ 517 518struct bfd_link_callbacks 519{ 520 /* A function which is called when an object is added from an 521 archive. ABFD is the archive element being added. NAME is the 522 name of the symbol which caused the archive element to be pulled 523 in. This function may set *SUBSBFD to point to an alternative 524 BFD from which symbols should in fact be added in place of the 525 original BFD's symbols. */ 526 bfd_boolean (*add_archive_element) 527 (struct bfd_link_info *, bfd *abfd, const char *name, bfd **subsbfd); 528 /* A function which is called when a symbol is found with multiple 529 definitions. H is the symbol which is defined multiple times. 530 NBFD is the new BFD, NSEC is the new section, and NVAL is the new 531 value. NSEC may be bfd_com_section or bfd_ind_section. */ 532 bfd_boolean (*multiple_definition) 533 (struct bfd_link_info *, struct bfd_link_hash_entry *h, 534 bfd *nbfd, asection *nsec, bfd_vma nval); 535 /* A function which is called when a common symbol is defined 536 multiple times. H is the symbol appearing multiple times. 537 NBFD is the BFD of the new symbol. NTYPE is the type of the new 538 symbol, one of bfd_link_hash_defined, bfd_link_hash_common, or 539 bfd_link_hash_indirect. If NTYPE is bfd_link_hash_common, NSIZE 540 is the size of the new symbol. */ 541 bfd_boolean (*multiple_common) 542 (struct bfd_link_info *, struct bfd_link_hash_entry *h, 543 bfd *nbfd, enum bfd_link_hash_type ntype, bfd_vma nsize); 544 /* A function which is called to add a symbol to a set. ENTRY is 545 the link hash table entry for the set itself (e.g., 546 __CTOR_LIST__). RELOC is the relocation to use for an entry in 547 the set when generating a relocatable file, and is also used to 548 get the size of the entry when generating an executable file. 549 ABFD, SEC and VALUE identify the value to add to the set. */ 550 bfd_boolean (*add_to_set) 551 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 552 bfd_reloc_code_real_type reloc, bfd *abfd, asection *sec, bfd_vma value); 553 /* A function which is called when the name of a g++ constructor or 554 destructor is found. This is only called by some object file 555 formats. CONSTRUCTOR is TRUE for a constructor, FALSE for a 556 destructor. This will use BFD_RELOC_CTOR when generating a 557 relocatable file. NAME is the name of the symbol found. ABFD, 558 SECTION and VALUE are the value of the symbol. */ 559 bfd_boolean (*constructor) 560 (struct bfd_link_info *, bfd_boolean constructor, const char *name, 561 bfd *abfd, asection *sec, bfd_vma value); 562 /* A function which is called to issue a linker warning. For 563 example, this is called when there is a reference to a warning 564 symbol. WARNING is the warning to be issued. SYMBOL is the name 565 of the symbol which triggered the warning; it may be NULL if 566 there is none. ABFD, SECTION and ADDRESS identify the location 567 which trigerred the warning; either ABFD or SECTION or both may 568 be NULL if the location is not known. */ 569 bfd_boolean (*warning) 570 (struct bfd_link_info *, const char *warning, const char *symbol, 571 bfd *abfd, asection *section, bfd_vma address); 572 /* A function which is called when a relocation is attempted against 573 an undefined symbol. NAME is the symbol which is undefined. 574 ABFD, SECTION and ADDRESS identify the location from which the 575 reference is made. IS_FATAL indicates whether an undefined symbol is 576 a fatal error or not. In some cases SECTION may be NULL. */ 577 bfd_boolean (*undefined_symbol) 578 (struct bfd_link_info *, const char *name, bfd *abfd, 579 asection *section, bfd_vma address, bfd_boolean is_fatal); 580 /* A function which is called when a reloc overflow occurs. ENTRY is 581 the link hash table entry for the symbol the reloc is against. 582 NAME is the name of the local symbol or section the reloc is 583 against, RELOC_NAME is the name of the relocation, and ADDEND is 584 any addend that is used. ABFD, SECTION and ADDRESS identify the 585 location at which the overflow occurs; if this is the result of a 586 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 587 ABFD will be NULL. */ 588 bfd_boolean (*reloc_overflow) 589 (struct bfd_link_info *, struct bfd_link_hash_entry *entry, 590 const char *name, const char *reloc_name, bfd_vma addend, 591 bfd *abfd, asection *section, bfd_vma address); 592 /* A function which is called when a dangerous reloc is performed. 593 MESSAGE is an appropriate message. 594 ABFD, SECTION and ADDRESS identify the location at which the 595 problem occurred; if this is the result of a 596 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 597 ABFD will be NULL. */ 598 bfd_boolean (*reloc_dangerous) 599 (struct bfd_link_info *, const char *message, 600 bfd *abfd, asection *section, bfd_vma address); 601 /* A function which is called when a reloc is found to be attached 602 to a symbol which is not being written out. NAME is the name of 603 the symbol. ABFD, SECTION and ADDRESS identify the location of 604 the reloc; if this is the result of a 605 bfd_section_reloc_link_order or bfd_symbol_reloc_link_order, then 606 ABFD will be NULL. */ 607 bfd_boolean (*unattached_reloc) 608 (struct bfd_link_info *, const char *name, 609 bfd *abfd, asection *section, bfd_vma address); 610 /* A function which is called when a symbol in notice_hash is 611 defined or referenced. H is the symbol. ABFD, SECTION and 612 ADDRESS are the (new) value of the symbol. If SECTION is 613 bfd_und_section, this is a reference. FLAGS are the symbol 614 BSF_* flags. STRING is the name of the symbol to indirect to if 615 the sym is indirect, or the warning string if a warning sym. */ 616 bfd_boolean (*notice) 617 (struct bfd_link_info *, struct bfd_link_hash_entry *h, 618 bfd *abfd, asection *section, bfd_vma address, flagword flags, 619 const char *string); 620 /* Error or warning link info message. */ 621 void (*einfo) 622 (const char *fmt, ...); 623 /* General link info message. */ 624 void (*info) 625 (const char *fmt, ...); 626 /* Message to be printed in linker map file. */ 627 void (*minfo) 628 (const char *fmt, ...); 629 /* This callback provides a chance for users of the BFD library to 630 override its decision about whether to place two adjacent sections 631 into the same segment. */ 632 bfd_boolean (*override_segment_assignment) 633 (struct bfd_link_info *, bfd * abfd, 634 asection * current_section, asection * previous_section, 635 bfd_boolean new_segment); 636}; 637 638/* The linker builds link_order structures which tell the code how to 639 include input data in the output file. */ 640 641/* These are the types of link_order structures. */ 642 643enum bfd_link_order_type 644{ 645 bfd_undefined_link_order, /* Undefined. */ 646 bfd_indirect_link_order, /* Built from a section. */ 647 bfd_data_link_order, /* Set to explicit data. */ 648 bfd_section_reloc_link_order, /* Relocate against a section. */ 649 bfd_symbol_reloc_link_order /* Relocate against a symbol. */ 650}; 651 652/* This is the link_order structure itself. These form a chain 653 attached to the output section whose contents they are describing. */ 654 655struct bfd_link_order 656{ 657 /* Next link_order in chain. */ 658 struct bfd_link_order *next; 659 /* Type of link_order. */ 660 enum bfd_link_order_type type; 661 /* Offset within output section. */ 662 bfd_vma offset; 663 /* Size within output section. */ 664 bfd_size_type size; 665 /* Type specific information. */ 666 union 667 { 668 struct 669 { 670 /* Section to include. If this is used, then 671 section->output_section must be the section the 672 link_order is attached to, section->output_offset must 673 equal the link_order offset field, and section->size 674 must equal the link_order size field. Maybe these 675 restrictions should be relaxed someday. */ 676 asection *section; 677 } indirect; 678 struct 679 { 680 /* Size of contents, or zero when contents should be filled by 681 the architecture-dependent fill function. 682 A non-zero value allows filling of the output section 683 with an arbitrary repeated pattern. */ 684 unsigned int size; 685 /* Data to put into file. */ 686 bfd_byte *contents; 687 } data; 688 struct 689 { 690 /* Description of reloc to generate. Used for 691 bfd_section_reloc_link_order and 692 bfd_symbol_reloc_link_order. */ 693 struct bfd_link_order_reloc *p; 694 } reloc; 695 } u; 696}; 697 698/* A linker order of type bfd_section_reloc_link_order or 699 bfd_symbol_reloc_link_order means to create a reloc against a 700 section or symbol, respectively. This is used to implement -Ur to 701 generate relocs for the constructor tables. The 702 bfd_link_order_reloc structure describes the reloc that BFD should 703 create. It is similar to a arelent, but I didn't use arelent 704 because the linker does not know anything about most symbols, and 705 any asymbol structure it creates will be partially meaningless. 706 This information could logically be in the bfd_link_order struct, 707 but I didn't want to waste the space since these types of relocs 708 are relatively rare. */ 709 710struct bfd_link_order_reloc 711{ 712 /* Reloc type. */ 713 bfd_reloc_code_real_type reloc; 714 715 union 716 { 717 /* For type bfd_section_reloc_link_order, this is the section 718 the reloc should be against. This must be a section in the 719 output BFD, not any of the input BFDs. */ 720 asection *section; 721 /* For type bfd_symbol_reloc_link_order, this is the name of the 722 symbol the reloc should be against. */ 723 const char *name; 724 } u; 725 726 /* Addend to use. The object file should contain zero. The BFD 727 backend is responsible for filling in the contents of the object 728 file correctly. For some object file formats (e.g., COFF) the 729 addend must be stored into in the object file, and for some 730 (e.g., SPARC a.out) it is kept in the reloc. */ 731 bfd_vma addend; 732}; 733 734/* Allocate a new link_order for a section. */ 735extern struct bfd_link_order *bfd_new_link_order (bfd *, asection *); 736 737/* These structures are used to describe version information for the 738 ELF linker. These structures could be manipulated entirely inside 739 BFD, but it would be a pain. Instead, the regular linker sets up 740 these structures, and then passes them into BFD. */ 741 742/* Glob pattern for a version. */ 743 744struct bfd_elf_version_expr 745{ 746 /* Next glob pattern for this version. */ 747 struct bfd_elf_version_expr *next; 748 /* Glob pattern. */ 749 const char *pattern; 750 /* Set if pattern is not a glob. */ 751 unsigned int literal : 1; 752 /* Defined by ".symver". */ 753 unsigned int symver : 1; 754 /* Defined by version script. */ 755 unsigned int script : 1; 756 /* Pattern type. */ 757#define BFD_ELF_VERSION_C_TYPE 1 758#define BFD_ELF_VERSION_CXX_TYPE 2 759#define BFD_ELF_VERSION_JAVA_TYPE 4 760 unsigned int mask : 3; 761}; 762 763struct bfd_elf_version_expr_head 764{ 765 /* List of all patterns, both wildcards and non-wildcards. */ 766 struct bfd_elf_version_expr *list; 767 /* Hash table for non-wildcards. */ 768 void *htab; 769 /* Remaining patterns. */ 770 struct bfd_elf_version_expr *remaining; 771 /* What kind of pattern types are present in list (bitmask). */ 772 unsigned int mask; 773}; 774 775/* Version dependencies. */ 776 777struct bfd_elf_version_deps 778{ 779 /* Next dependency for this version. */ 780 struct bfd_elf_version_deps *next; 781 /* The version which this version depends upon. */ 782 struct bfd_elf_version_tree *version_needed; 783}; 784 785/* A node in the version tree. */ 786 787struct bfd_elf_version_tree 788{ 789 /* Next version. */ 790 struct bfd_elf_version_tree *next; 791 /* Name of this version. */ 792 const char *name; 793 /* Version number. */ 794 unsigned int vernum; 795 /* Regular expressions for global symbols in this version. */ 796 struct bfd_elf_version_expr_head globals; 797 /* Regular expressions for local symbols in this version. */ 798 struct bfd_elf_version_expr_head locals; 799 /* List of versions which this version depends upon. */ 800 struct bfd_elf_version_deps *deps; 801 /* Index of the version name. This is used within BFD. */ 802 unsigned int name_indx; 803 /* Whether this version tree was used. This is used within BFD. */ 804 int used; 805 /* Matching hook. */ 806 struct bfd_elf_version_expr *(*match) 807 (struct bfd_elf_version_expr_head *head, 808 struct bfd_elf_version_expr *prev, const char *sym); 809}; 810 811struct bfd_elf_dynamic_list 812{ 813 struct bfd_elf_version_expr_head head; 814 struct bfd_elf_version_expr *(*match) 815 (struct bfd_elf_version_expr_head *head, 816 struct bfd_elf_version_expr *prev, const char *sym); 817}; 818 819#endif 820