targets.texi revision 1.1.1.3
1@section Targets 2 3 4@strong{Description}@* 5Each port of BFD to a different machine requires the creation 6of a target back end. All the back end provides to the root 7part of BFD is a structure containing pointers to functions 8which perform certain low level operations on files. BFD 9translates the applications's requests through a pointer into 10calls to the back end routines. 11 12When a file is opened with @code{bfd_openr}, its format and 13target are unknown. BFD uses various mechanisms to determine 14how to interpret the file. The operations performed are: 15 16@itemize @bullet 17 18@item 19Create a BFD by calling the internal routine 20@code{_bfd_new_bfd}, then call @code{bfd_find_target} with the 21target string supplied to @code{bfd_openr} and the new BFD pointer. 22 23@item 24If a null target string was provided to @code{bfd_find_target}, 25look up the environment variable @code{GNUTARGET} and use 26that as the target string. 27 28@item 29If the target string is still @code{NULL}, or the target string is 30@code{default}, then use the first item in the target vector 31as the target type, and set @code{target_defaulted} in the BFD to 32cause @code{bfd_check_format} to loop through all the targets. 33@xref{bfd_target}. @xref{Formats}. 34 35@item 36Otherwise, inspect the elements in the target vector 37one by one, until a match on target name is found. When found, 38use it. 39 40@item 41Otherwise return the error @code{bfd_error_invalid_target} to 42@code{bfd_openr}. 43 44@item 45@code{bfd_openr} attempts to open the file using 46@code{bfd_open_file}, and returns the BFD. 47@end itemize 48Once the BFD has been opened and the target selected, the file 49format may be determined. This is done by calling 50@code{bfd_check_format} on the BFD with a suggested format. 51If @code{target_defaulted} has been set, each possible target 52type is tried to see if it recognizes the specified format. 53@code{bfd_check_format} returns @code{TRUE} when the caller guesses right. 54@menu 55* bfd_target:: 56@end menu 57 58@node bfd_target, , Targets, Targets 59 60@subsection bfd_target 61 62 63@strong{Description}@* 64This structure contains everything that BFD knows about a 65target. It includes things like its byte order, name, and which 66routines to call to do various operations. 67 68Every BFD points to a target structure with its @code{xvec} 69member. 70 71The macros below are used to dispatch to functions through the 72@code{bfd_target} vector. They are used in a number of macros further 73down in @file{bfd.h}, and are also used when calling various 74routines by hand inside the BFD implementation. The @var{arglist} 75argument must be parenthesized; it contains all the arguments 76to the called function. 77 78They make the documentation (more) unpleasant to read, so if 79someone wants to fix this and not break the above, please do. 80@example 81#define BFD_SEND(bfd, message, arglist) \ 82 ((*((bfd)->xvec->message)) arglist) 83 84#ifdef DEBUG_BFD_SEND 85#undef BFD_SEND 86#define BFD_SEND(bfd, message, arglist) \ 87 (((bfd) && (bfd)->xvec && (bfd)->xvec->message) ? \ 88 ((*((bfd)->xvec->message)) arglist) : \ 89 (bfd_assert (__FILE__,__LINE__), NULL)) 90#endif 91@end example 92For operations which index on the BFD format: 93@example 94#define BFD_SEND_FMT(bfd, message, arglist) \ 95 (((bfd)->xvec->message[(int) ((bfd)->format)]) arglist) 96 97#ifdef DEBUG_BFD_SEND 98#undef BFD_SEND_FMT 99#define BFD_SEND_FMT(bfd, message, arglist) \ 100 (((bfd) && (bfd)->xvec && (bfd)->xvec->message) ? \ 101 (((bfd)->xvec->message[(int) ((bfd)->format)]) arglist) : \ 102 (bfd_assert (__FILE__,__LINE__), NULL)) 103#endif 104 105@end example 106This is the structure which defines the type of BFD this is. The 107@code{xvec} member of the struct @code{bfd} itself points here. Each 108module that implements access to a different target under BFD, 109defines one of these. 110 111FIXME, these names should be rationalised with the names of 112the entry points which call them. Too bad we can't have one 113macro to define them both! 114@example 115enum bfd_flavour 116@{ 117 bfd_target_unknown_flavour, 118 bfd_target_aout_flavour, 119 bfd_target_coff_flavour, 120 bfd_target_ecoff_flavour, 121 bfd_target_xcoff_flavour, 122 bfd_target_elf_flavour, 123 bfd_target_ieee_flavour, 124 bfd_target_nlm_flavour, 125 bfd_target_oasys_flavour, 126 bfd_target_tekhex_flavour, 127 bfd_target_srec_flavour, 128 bfd_target_verilog_flavour, 129 bfd_target_ihex_flavour, 130 bfd_target_som_flavour, 131 bfd_target_os9k_flavour, 132 bfd_target_versados_flavour, 133 bfd_target_msdos_flavour, 134 bfd_target_ovax_flavour, 135 bfd_target_evax_flavour, 136 bfd_target_mmo_flavour, 137 bfd_target_mach_o_flavour, 138 bfd_target_pef_flavour, 139 bfd_target_pef_xlib_flavour, 140 bfd_target_sym_flavour 141@}; 142 143enum bfd_endian @{ BFD_ENDIAN_BIG, BFD_ENDIAN_LITTLE, BFD_ENDIAN_UNKNOWN @}; 144 145/* Forward declaration. */ 146typedef struct bfd_link_info _bfd_link_info; 147 148/* Forward declaration. */ 149typedef struct flag_info flag_info; 150 151typedef struct bfd_target 152@{ 153 /* Identifies the kind of target, e.g., SunOS4, Ultrix, etc. */ 154 char *name; 155 156 /* The "flavour" of a back end is a general indication about 157 the contents of a file. */ 158 enum bfd_flavour flavour; 159 160 /* The order of bytes within the data area of a file. */ 161 enum bfd_endian byteorder; 162 163 /* The order of bytes within the header parts of a file. */ 164 enum bfd_endian header_byteorder; 165 166 /* A mask of all the flags which an executable may have set - 167 from the set @code{BFD_NO_FLAGS}, @code{HAS_RELOC}, ...@code{D_PAGED}. */ 168 flagword object_flags; 169 170 /* A mask of all the flags which a section may have set - from 171 the set @code{SEC_NO_FLAGS}, @code{SEC_ALLOC}, ...@code{SET_NEVER_LOAD}. */ 172 flagword section_flags; 173 174 /* The character normally found at the front of a symbol. 175 (if any), perhaps `_'. */ 176 char symbol_leading_char; 177 178 /* The pad character for file names within an archive header. */ 179 char ar_pad_char; 180 181 /* The maximum number of characters in an archive header. */ 182 unsigned char ar_max_namelen; 183 184 /* How well this target matches, used to select between various 185 possible targets when more than one target matches. */ 186 unsigned char match_priority; 187 188 /* Entries for byte swapping for data. These are different from the 189 other entry points, since they don't take a BFD as the first argument. 190 Certain other handlers could do the same. */ 191 bfd_uint64_t (*bfd_getx64) (const void *); 192 bfd_int64_t (*bfd_getx_signed_64) (const void *); 193 void (*bfd_putx64) (bfd_uint64_t, void *); 194 bfd_vma (*bfd_getx32) (const void *); 195 bfd_signed_vma (*bfd_getx_signed_32) (const void *); 196 void (*bfd_putx32) (bfd_vma, void *); 197 bfd_vma (*bfd_getx16) (const void *); 198 bfd_signed_vma (*bfd_getx_signed_16) (const void *); 199 void (*bfd_putx16) (bfd_vma, void *); 200 201 /* Byte swapping for the headers. */ 202 bfd_uint64_t (*bfd_h_getx64) (const void *); 203 bfd_int64_t (*bfd_h_getx_signed_64) (const void *); 204 void (*bfd_h_putx64) (bfd_uint64_t, void *); 205 bfd_vma (*bfd_h_getx32) (const void *); 206 bfd_signed_vma (*bfd_h_getx_signed_32) (const void *); 207 void (*bfd_h_putx32) (bfd_vma, void *); 208 bfd_vma (*bfd_h_getx16) (const void *); 209 bfd_signed_vma (*bfd_h_getx_signed_16) (const void *); 210 void (*bfd_h_putx16) (bfd_vma, void *); 211 212 /* Format dependent routines: these are vectors of entry points 213 within the target vector structure, one for each format to check. */ 214 215 /* Check the format of a file being read. Return a @code{bfd_target *} or zero. */ 216 const struct bfd_target *(*_bfd_check_format[bfd_type_end]) (bfd *); 217 218 /* Set the format of a file being written. */ 219 bfd_boolean (*_bfd_set_format[bfd_type_end]) (bfd *); 220 221 /* Write cached information into a file being written, at @code{bfd_close}. */ 222 bfd_boolean (*_bfd_write_contents[bfd_type_end]) (bfd *); 223 224@end example 225The general target vector. These vectors are initialized using the 226BFD_JUMP_TABLE macros. 227@example 228 229 /* Generic entry points. */ 230#define BFD_JUMP_TABLE_GENERIC(NAME) \ 231 NAME##_close_and_cleanup, \ 232 NAME##_bfd_free_cached_info, \ 233 NAME##_new_section_hook, \ 234 NAME##_get_section_contents, \ 235 NAME##_get_section_contents_in_window 236 237 /* Called when the BFD is being closed to do any necessary cleanup. */ 238 bfd_boolean (*_close_and_cleanup) (bfd *); 239 /* Ask the BFD to free all cached information. */ 240 bfd_boolean (*_bfd_free_cached_info) (bfd *); 241 /* Called when a new section is created. */ 242 bfd_boolean (*_new_section_hook) (bfd *, sec_ptr); 243 /* Read the contents of a section. */ 244 bfd_boolean (*_bfd_get_section_contents) 245 (bfd *, sec_ptr, void *, file_ptr, bfd_size_type); 246 bfd_boolean (*_bfd_get_section_contents_in_window) 247 (bfd *, sec_ptr, bfd_window *, file_ptr, bfd_size_type); 248 249 /* Entry points to copy private data. */ 250#define BFD_JUMP_TABLE_COPY(NAME) \ 251 NAME##_bfd_copy_private_bfd_data, \ 252 NAME##_bfd_merge_private_bfd_data, \ 253 _bfd_generic_init_private_section_data, \ 254 NAME##_bfd_copy_private_section_data, \ 255 NAME##_bfd_copy_private_symbol_data, \ 256 NAME##_bfd_copy_private_header_data, \ 257 NAME##_bfd_set_private_flags, \ 258 NAME##_bfd_print_private_bfd_data 259 260 /* Called to copy BFD general private data from one object file 261 to another. */ 262 bfd_boolean (*_bfd_copy_private_bfd_data) (bfd *, bfd *); 263 /* Called to merge BFD general private data from one object file 264 to a common output file when linking. */ 265 bfd_boolean (*_bfd_merge_private_bfd_data) (bfd *, bfd *); 266 /* Called to initialize BFD private section data from one object file 267 to another. */ 268#define bfd_init_private_section_data(ibfd, isec, obfd, osec, link_info) \ 269 BFD_SEND (obfd, _bfd_init_private_section_data, (ibfd, isec, obfd, osec, link_info)) 270 bfd_boolean (*_bfd_init_private_section_data) 271 (bfd *, sec_ptr, bfd *, sec_ptr, struct bfd_link_info *); 272 /* Called to copy BFD private section data from one object file 273 to another. */ 274 bfd_boolean (*_bfd_copy_private_section_data) 275 (bfd *, sec_ptr, bfd *, sec_ptr); 276 /* Called to copy BFD private symbol data from one symbol 277 to another. */ 278 bfd_boolean (*_bfd_copy_private_symbol_data) 279 (bfd *, asymbol *, bfd *, asymbol *); 280 /* Called to copy BFD private header data from one object file 281 to another. */ 282 bfd_boolean (*_bfd_copy_private_header_data) 283 (bfd *, bfd *); 284 /* Called to set private backend flags. */ 285 bfd_boolean (*_bfd_set_private_flags) (bfd *, flagword); 286 287 /* Called to print private BFD data. */ 288 bfd_boolean (*_bfd_print_private_bfd_data) (bfd *, void *); 289 290 /* Core file entry points. */ 291#define BFD_JUMP_TABLE_CORE(NAME) \ 292 NAME##_core_file_failing_command, \ 293 NAME##_core_file_failing_signal, \ 294 NAME##_core_file_matches_executable_p, \ 295 NAME##_core_file_pid 296 297 char * (*_core_file_failing_command) (bfd *); 298 int (*_core_file_failing_signal) (bfd *); 299 bfd_boolean (*_core_file_matches_executable_p) (bfd *, bfd *); 300 int (*_core_file_pid) (bfd *); 301 302 /* Archive entry points. */ 303#define BFD_JUMP_TABLE_ARCHIVE(NAME) \ 304 NAME##_slurp_armap, \ 305 NAME##_slurp_extended_name_table, \ 306 NAME##_construct_extended_name_table, \ 307 NAME##_truncate_arname, \ 308 NAME##_write_armap, \ 309 NAME##_read_ar_hdr, \ 310 NAME##_write_ar_hdr, \ 311 NAME##_openr_next_archived_file, \ 312 NAME##_get_elt_at_index, \ 313 NAME##_generic_stat_arch_elt, \ 314 NAME##_update_armap_timestamp 315 316 bfd_boolean (*_bfd_slurp_armap) (bfd *); 317 bfd_boolean (*_bfd_slurp_extended_name_table) (bfd *); 318 bfd_boolean (*_bfd_construct_extended_name_table) 319 (bfd *, char **, bfd_size_type *, const char **); 320 void (*_bfd_truncate_arname) (bfd *, const char *, char *); 321 bfd_boolean (*write_armap) 322 (bfd *, unsigned int, struct orl *, unsigned int, int); 323 void * (*_bfd_read_ar_hdr_fn) (bfd *); 324 bfd_boolean (*_bfd_write_ar_hdr_fn) (bfd *, bfd *); 325 bfd * (*openr_next_archived_file) (bfd *, bfd *); 326#define bfd_get_elt_at_index(b,i) BFD_SEND (b, _bfd_get_elt_at_index, (b,i)) 327 bfd * (*_bfd_get_elt_at_index) (bfd *, symindex); 328 int (*_bfd_stat_arch_elt) (bfd *, struct stat *); 329 bfd_boolean (*_bfd_update_armap_timestamp) (bfd *); 330 331 /* Entry points used for symbols. */ 332#define BFD_JUMP_TABLE_SYMBOLS(NAME) \ 333 NAME##_get_symtab_upper_bound, \ 334 NAME##_canonicalize_symtab, \ 335 NAME##_make_empty_symbol, \ 336 NAME##_print_symbol, \ 337 NAME##_get_symbol_info, \ 338 NAME##_bfd_is_local_label_name, \ 339 NAME##_bfd_is_target_special_symbol, \ 340 NAME##_get_lineno, \ 341 NAME##_find_nearest_line, \ 342 _bfd_generic_find_nearest_line_discriminator, \ 343 _bfd_generic_find_line, \ 344 NAME##_find_inliner_info, \ 345 NAME##_bfd_make_debug_symbol, \ 346 NAME##_read_minisymbols, \ 347 NAME##_minisymbol_to_symbol 348 349 long (*_bfd_get_symtab_upper_bound) (bfd *); 350 long (*_bfd_canonicalize_symtab) 351 (bfd *, struct bfd_symbol **); 352 struct bfd_symbol * 353 (*_bfd_make_empty_symbol) (bfd *); 354 void (*_bfd_print_symbol) 355 (bfd *, void *, struct bfd_symbol *, bfd_print_symbol_type); 356#define bfd_print_symbol(b,p,s,e) BFD_SEND (b, _bfd_print_symbol, (b,p,s,e)) 357 void (*_bfd_get_symbol_info) 358 (bfd *, struct bfd_symbol *, symbol_info *); 359#define bfd_get_symbol_info(b,p,e) BFD_SEND (b, _bfd_get_symbol_info, (b,p,e)) 360 bfd_boolean (*_bfd_is_local_label_name) (bfd *, const char *); 361 bfd_boolean (*_bfd_is_target_special_symbol) (bfd *, asymbol *); 362 alent * (*_get_lineno) (bfd *, struct bfd_symbol *); 363 bfd_boolean (*_bfd_find_nearest_line) 364 (bfd *, struct bfd_section *, struct bfd_symbol **, bfd_vma, 365 const char **, const char **, unsigned int *); 366 bfd_boolean (*_bfd_find_nearest_line_discriminator) 367 (bfd *, struct bfd_section *, struct bfd_symbol **, bfd_vma, 368 const char **, const char **, unsigned int *, unsigned int *); 369 bfd_boolean (*_bfd_find_line) 370 (bfd *, struct bfd_symbol **, struct bfd_symbol *, 371 const char **, unsigned int *); 372 bfd_boolean (*_bfd_find_inliner_info) 373 (bfd *, const char **, const char **, unsigned int *); 374 /* Back-door to allow format-aware applications to create debug symbols 375 while using BFD for everything else. Currently used by the assembler 376 when creating COFF files. */ 377 asymbol * (*_bfd_make_debug_symbol) 378 (bfd *, void *, unsigned long size); 379#define bfd_read_minisymbols(b, d, m, s) \ 380 BFD_SEND (b, _read_minisymbols, (b, d, m, s)) 381 long (*_read_minisymbols) 382 (bfd *, bfd_boolean, void **, unsigned int *); 383#define bfd_minisymbol_to_symbol(b, d, m, f) \ 384 BFD_SEND (b, _minisymbol_to_symbol, (b, d, m, f)) 385 asymbol * (*_minisymbol_to_symbol) 386 (bfd *, bfd_boolean, const void *, asymbol *); 387 388 /* Routines for relocs. */ 389#define BFD_JUMP_TABLE_RELOCS(NAME) \ 390 NAME##_get_reloc_upper_bound, \ 391 NAME##_canonicalize_reloc, \ 392 NAME##_bfd_reloc_type_lookup, \ 393 NAME##_bfd_reloc_name_lookup 394 395 long (*_get_reloc_upper_bound) (bfd *, sec_ptr); 396 long (*_bfd_canonicalize_reloc) 397 (bfd *, sec_ptr, arelent **, struct bfd_symbol **); 398 /* See documentation on reloc types. */ 399 reloc_howto_type * 400 (*reloc_type_lookup) (bfd *, bfd_reloc_code_real_type); 401 reloc_howto_type * 402 (*reloc_name_lookup) (bfd *, const char *); 403 404 405 /* Routines used when writing an object file. */ 406#define BFD_JUMP_TABLE_WRITE(NAME) \ 407 NAME##_set_arch_mach, \ 408 NAME##_set_section_contents 409 410 bfd_boolean (*_bfd_set_arch_mach) 411 (bfd *, enum bfd_architecture, unsigned long); 412 bfd_boolean (*_bfd_set_section_contents) 413 (bfd *, sec_ptr, const void *, file_ptr, bfd_size_type); 414 415 /* Routines used by the linker. */ 416#define BFD_JUMP_TABLE_LINK(NAME) \ 417 NAME##_sizeof_headers, \ 418 NAME##_bfd_get_relocated_section_contents, \ 419 NAME##_bfd_relax_section, \ 420 NAME##_bfd_link_hash_table_create, \ 421 NAME##_bfd_link_hash_table_free, \ 422 NAME##_bfd_link_add_symbols, \ 423 NAME##_bfd_link_just_syms, \ 424 NAME##_bfd_copy_link_hash_symbol_type, \ 425 NAME##_bfd_final_link, \ 426 NAME##_bfd_link_split_section, \ 427 NAME##_bfd_gc_sections, \ 428 NAME##_bfd_lookup_section_flags, \ 429 NAME##_bfd_merge_sections, \ 430 NAME##_bfd_is_group_section, \ 431 NAME##_bfd_discard_group, \ 432 NAME##_section_already_linked, \ 433 NAME##_bfd_define_common_symbol 434 435 int (*_bfd_sizeof_headers) (bfd *, struct bfd_link_info *); 436 bfd_byte * (*_bfd_get_relocated_section_contents) 437 (bfd *, struct bfd_link_info *, struct bfd_link_order *, 438 bfd_byte *, bfd_boolean, struct bfd_symbol **); 439 440 bfd_boolean (*_bfd_relax_section) 441 (bfd *, struct bfd_section *, struct bfd_link_info *, bfd_boolean *); 442 443 /* Create a hash table for the linker. Different backends store 444 different information in this table. */ 445 struct bfd_link_hash_table * 446 (*_bfd_link_hash_table_create) (bfd *); 447 448 /* Release the memory associated with the linker hash table. */ 449 void (*_bfd_link_hash_table_free) (struct bfd_link_hash_table *); 450 451 /* Add symbols from this object file into the hash table. */ 452 bfd_boolean (*_bfd_link_add_symbols) (bfd *, struct bfd_link_info *); 453 454 /* Indicate that we are only retrieving symbol values from this section. */ 455 void (*_bfd_link_just_syms) (asection *, struct bfd_link_info *); 456 457 /* Copy the symbol type of a linker hash table entry. */ 458#define bfd_copy_link_hash_symbol_type(b, t, f) \ 459 BFD_SEND (b, _bfd_copy_link_hash_symbol_type, (b, t, f)) 460 void (*_bfd_copy_link_hash_symbol_type) 461 (bfd *, struct bfd_link_hash_entry *, struct bfd_link_hash_entry *); 462 463 /* Do a link based on the link_order structures attached to each 464 section of the BFD. */ 465 bfd_boolean (*_bfd_final_link) (bfd *, struct bfd_link_info *); 466 467 /* Should this section be split up into smaller pieces during linking. */ 468 bfd_boolean (*_bfd_link_split_section) (bfd *, struct bfd_section *); 469 470 /* Remove sections that are not referenced from the output. */ 471 bfd_boolean (*_bfd_gc_sections) (bfd *, struct bfd_link_info *); 472 473 /* Sets the bitmask of allowed and disallowed section flags. */ 474 bfd_boolean (*_bfd_lookup_section_flags) (struct bfd_link_info *, 475 struct flag_info *, 476 asection *); 477 478 /* Attempt to merge SEC_MERGE sections. */ 479 bfd_boolean (*_bfd_merge_sections) (bfd *, struct bfd_link_info *); 480 481 /* Is this section a member of a group? */ 482 bfd_boolean (*_bfd_is_group_section) (bfd *, const struct bfd_section *); 483 484 /* Discard members of a group. */ 485 bfd_boolean (*_bfd_discard_group) (bfd *, struct bfd_section *); 486 487 /* Check if SEC has been already linked during a reloceatable or 488 final link. */ 489 bfd_boolean (*_section_already_linked) (bfd *, asection *, 490 struct bfd_link_info *); 491 492 /* Define a common symbol. */ 493 bfd_boolean (*_bfd_define_common_symbol) (bfd *, struct bfd_link_info *, 494 struct bfd_link_hash_entry *); 495 496 /* Routines to handle dynamic symbols and relocs. */ 497#define BFD_JUMP_TABLE_DYNAMIC(NAME) \ 498 NAME##_get_dynamic_symtab_upper_bound, \ 499 NAME##_canonicalize_dynamic_symtab, \ 500 NAME##_get_synthetic_symtab, \ 501 NAME##_get_dynamic_reloc_upper_bound, \ 502 NAME##_canonicalize_dynamic_reloc 503 504 /* Get the amount of memory required to hold the dynamic symbols. */ 505 long (*_bfd_get_dynamic_symtab_upper_bound) (bfd *); 506 /* Read in the dynamic symbols. */ 507 long (*_bfd_canonicalize_dynamic_symtab) 508 (bfd *, struct bfd_symbol **); 509 /* Create synthetized symbols. */ 510 long (*_bfd_get_synthetic_symtab) 511 (bfd *, long, struct bfd_symbol **, long, struct bfd_symbol **, 512 struct bfd_symbol **); 513 /* Get the amount of memory required to hold the dynamic relocs. */ 514 long (*_bfd_get_dynamic_reloc_upper_bound) (bfd *); 515 /* Read in the dynamic relocs. */ 516 long (*_bfd_canonicalize_dynamic_reloc) 517 (bfd *, arelent **, struct bfd_symbol **); 518 519@end example 520A pointer to an alternative bfd_target in case the current one is not 521satisfactory. This can happen when the target cpu supports both big 522and little endian code, and target chosen by the linker has the wrong 523endianness. The function open_output() in ld/ldlang.c uses this field 524to find an alternative output format that is suitable. 525@example 526 /* Opposite endian version of this target. */ 527 const struct bfd_target * alternative_target; 528 529 /* Data for use by back-end routines, which isn't 530 generic enough to belong in this structure. */ 531 const void *backend_data; 532 533@} bfd_target; 534 535@end example 536 537@findex bfd_set_default_target 538@subsubsection @code{bfd_set_default_target} 539@strong{Synopsis} 540@example 541bfd_boolean bfd_set_default_target (const char *name); 542@end example 543@strong{Description}@* 544Set the default target vector to use when recognizing a BFD. 545This takes the name of the target, which may be a BFD target 546name or a configuration triplet. 547 548@findex bfd_find_target 549@subsubsection @code{bfd_find_target} 550@strong{Synopsis} 551@example 552const bfd_target *bfd_find_target (const char *target_name, bfd *abfd); 553@end example 554@strong{Description}@* 555Return a pointer to the transfer vector for the object target 556named @var{target_name}. If @var{target_name} is @code{NULL}, 557choose the one in the environment variable @code{GNUTARGET}; if 558that is null or not defined, then choose the first entry in the 559target list. Passing in the string "default" or setting the 560environment variable to "default" will cause the first entry in 561the target list to be returned, and "target_defaulted" will be 562set in the BFD if @var{abfd} isn't @code{NULL}. This causes 563@code{bfd_check_format} to loop over all the targets to find the 564one that matches the file being read. 565 566@findex bfd_get_target_info 567@subsubsection @code{bfd_get_target_info} 568@strong{Synopsis} 569@example 570const bfd_target *bfd_get_target_info (const char *target_name, 571 bfd *abfd, 572 bfd_boolean *is_bigendian, 573 int *underscoring, 574 const char **def_target_arch); 575@end example 576@strong{Description}@* 577Return a pointer to the transfer vector for the object target 578named @var{target_name}. If @var{target_name} is @code{NULL}, 579choose the one in the environment variable @code{GNUTARGET}; if 580that is null or not defined, then choose the first entry in the 581target list. Passing in the string "default" or setting the 582environment variable to "default" will cause the first entry in 583the target list to be returned, and "target_defaulted" will be 584set in the BFD if @var{abfd} isn't @code{NULL}. This causes 585@code{bfd_check_format} to loop over all the targets to find the 586one that matches the file being read. 587If @var{is_bigendian} is not @code{NULL}, then set this value to target's 588endian mode. True for big-endian, FALSE for little-endian or for 589invalid target. 590If @var{underscoring} is not @code{NULL}, then set this value to target's 591underscoring mode. Zero for none-underscoring, -1 for invalid target, 592else the value of target vector's symbol underscoring. 593If @var{def_target_arch} is not @code{NULL}, then set it to the architecture 594string specified by the target_name. 595 596@findex bfd_target_list 597@subsubsection @code{bfd_target_list} 598@strong{Synopsis} 599@example 600const char ** bfd_target_list (void); 601@end example 602@strong{Description}@* 603Return a freshly malloced NULL-terminated 604vector of the names of all the valid BFD targets. Do not 605modify the names. 606 607@findex bfd_seach_for_target 608@subsubsection @code{bfd_seach_for_target} 609@strong{Synopsis} 610@example 611const bfd_target *bfd_search_for_target 612 (int (*search_func) (const bfd_target *, void *), 613 void *); 614@end example 615@strong{Description}@* 616Return a pointer to the first transfer vector in the list of 617transfer vectors maintained by BFD that produces a non-zero 618result when passed to the function @var{search_func}. The 619parameter @var{data} is passed, unexamined, to the search 620function. 621 622