bfd/targets.c

   1 /* Generic target-file-type support for the BFD library.
   2    Copyright (C) 1990-1991 Free Software Foundation, Inc.
   3    Written by 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 2 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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 /* $Id$ */
  22
  23 #include "bfd.h"
  24 #include "sysdep.h"
  25 #include "libbfd.h"
  26
  27 /*doc*
  28 @section Targets
  29 Each port of BFD to a different machine requries the creation of a
  30 target back end. All the back end provides to the root part of BFD is
  31 a structure containing pointers to functions which perform certain low
  32 level operations on files. BFD translates the applications's requests
  33 through a pointer into calls to the back end routines.
  34
  35 When a file is opened with @code{bfd_openr}, its format and target are
  36 unknown. BFD uses various mechanisms to determine how to interpret the
  37 file. The operations performed are:
  38 @itemize @bullet
  39 @item
  40 First a BFD is created by calling the internal routine
  41 @code{new_bfd}, then @code{bfd_find_target} is called with the target
  42 string supplied to @code{bfd_openr} and the new BFD pointer.
  43 @item
  44 If a null target string was provided to
  45 @code{bfd_find_target}, it looks up the environment variable
  46 @code{GNUTARGET} and uses that as the target string.
  47 @item
  48 If the target string is still NULL, or the target string
  49 is @code{default}, then the first item in the target vector is used as
  50 the target type. @xref{bfd_target}.
  51 @item
  52 Otherwise, the elements in the target vector are
  53 inspected one by one, until a match on target name is found. When
  54 found, that is used.
  55 @item
  56 Otherwise the error @code{invalid_target} is returned to
  57 @code{bfd_openr}.
  58 @item
  59 @code{bfd_openr} attempts to open the file using
  60 @code{bfd_open_file}, and returns the BFD.
  61 @end itemize
  62 Once the BFD has been opened and the target selected, the file format
  63 may be determined. This is done by calling @code{bfd_check_format} on
  64 the BFD with a suggested format. The routine returns @code{true} when
  65 the application guesses right.
  66
  67 @menu
  68 * bfd_target::
  69 @end menu
  70 */
  71
  72
  73 /*proto* bfd_target
  74 @node bfd_target,  , Targets, Targets
  75 @subsection bfd_target
  76 This structure contains everything that BFD knows about a target.
  77 It includes things like its byte order, name, what routines to call
  78 to do various operations, etc.
  79
  80 Every BFD points to a target structure with its "xvec" member.
  81
  82
  83 Shortcut for declaring fields which are prototyped function pointers,
  84 while avoiding anguish on compilers that don't support protos.
  85
  86 $#define SDEF(ret, name, arglist) \
  87 $                PROTO(ret,(*name),arglist)
  88 $#define SDEF_FMT(ret, name, arglist) \
  89 $                PROTO(ret,(*name[bfd_type_end]),arglist)
  90
  91 These macros are used to dispatch to functions through the bfd_target
  92 vector. They are used in a number of macros further down in @file{bfd.h}, and
  93 are also used when calling various routines by hand inside the BFD
  94 implementation.  The "arglist" argument must be parenthesized; it
  95 contains all the arguments to the called function.
  96
  97 $#define BFD_SEND(bfd, message, arglist) \
  98 $               ((*((bfd)->xvec->message)) arglist)
  99
 100 For operations which index on the BFD format
 101
 102 $#define BFD_SEND_FMT(bfd, message, arglist) \
 103 $            (((bfd)->xvec->message[(int)((bfd)->format)]) arglist)
 104
 105 This is the struct which defines the type of BFD this is.  The
 106 "xvec" member of the struct @code{bfd} itself points here.  Each module
 107 that implements access to a different target under BFD, defines
 108 one of these.
 109
 110 FIXME, these names should be rationalised with the names of the
 111 entry points which call them. Too bad we can't have one macro to
 112 define them both!
 113
 114 *+++
 115
 116 $typedef struct bfd_target
 117 ${
 118
 119 identifies the kind of target, eg SunOS4, Ultrix, etc
 120
 121 $  char *name;
 122
 123 The "flavour" of a back end is a general indication about the contents
 124 of a file.
 125
 126 $  enum target_flavour {
 127 $    bfd_target_unknown_flavour,
 128 $    bfd_target_aout_flavour,
 129 $    bfd_target_coff_flavour,
 130 $    bfd_target_elf_flavour,
 131 $    bfd_target_ieee_flavour,
 132 $    bfd_target_oasys_flavour,
 133 $    bfd_target_srec_flavour} flavour;
 134
 135 The order of bytes within the data area of a file.
 136
 137 $  boolean byteorder_big_p;
 138
 139 The order of bytes within the header parts of a file.
 140
 141 $  boolean header_byteorder_big_p;
 142
 143 This is a mask of all the flags which an executable may have set -
 144 from the set @code{NO_FLAGS}, @code{HAS_RELOC}, ...@code{D_PAGED}.
 145
 146 $  flagword object_flags;
 147
 148 This is a mask of all the flags which a section may have set - from
 149 the set @code{SEC_NO_FLAGS}, @code{SEC_ALLOC}, ...@code{SET_NEVER_LOAD}.
 150
 151 $  flagword section_flags;
 152
 153 The pad character for filenames within an archive header.
 154
 155 $  char ar_pad_char;
 156
 157 The maximum number of characters in an archive header.
 158
 159 $ unsigned short ar_max_namelen;
 160
 161 The minimum alignment restriction for any section.
 162
 163 $  unsigned int align_power_min;
 164
 165 Entries for byte swapping for data. These are different to the other
 166 entry points, since they don't take BFD as first arg.  Certain other handlers
 167 could do the same.
 168
 169 $  SDEF (bfd_vma,      bfd_getx64, (bfd_byte *));
 170 $  SDEF (void,         bfd_putx64, (bfd_vma, bfd_byte *));
 171 $  SDEF (bfd_vma, bfd_getx32, (bfd_byte *));
 172 $  SDEF (void,         bfd_putx32, (bfd_vma, bfd_byte *));
 173 $  SDEF (bfd_vma, bfd_getx16, (bfd_byte *));
 174 $  SDEF (void,         bfd_putx16, (bfd_vma, bfd_byte *));
 175
 176 Byte swapping for the headers
 177
 178 $  SDEF (bfd_vma,   bfd_h_getx64, (bfd_byte *));
 179 $  SDEF (void,          bfd_h_putx64, (bfd_vma, bfd_byte *));
 180 $  SDEF (bfd_vma,  bfd_h_getx32, (bfd_byte *));
 181 $  SDEF (void,          bfd_h_putx32, (bfd_vma, bfd_byte *));
 182 $  SDEF (bfd_vma,  bfd_h_getx16, (bfd_byte *));
 183 $  SDEF (void,          bfd_h_putx16, (bfd_vma, bfd_byte *));
 184
 185 Format dependent routines, these turn into vectors of entry points
 186 within the target vector structure; one for each format to check.
 187
 188 Check the format of a file being read.  Return bfd_target * or zero.
 189
 190 $  SDEF_FMT (struct bfd_target *, _bfd_check_format, (bfd *));
 191
 192 Set the format of a file being written.
 193
 194 $  SDEF_FMT (boolean,            _bfd_set_format, (bfd *));
 195
 196 Write cached information into a file being written, at bfd_close.
 197
 198 $  SDEF_FMT (boolean,            _bfd_write_contents, (bfd *));
 199
 200 The following functions are defined in @code{JUMP_TABLE}. The idea is
 201 that the back end writer of @code{foo} names all the routines
 202 @code{foo_}@var{entry_point}, @code{JUMP_TABLE} will built the entries
 203 in this structure in the right order.
 204
 205 Core file entry points
 206
 207 $  SDEF (char *, _core_file_failing_command, (bfd *));
 208 $  SDEF (int,    _core_file_failing_signal, (bfd *));
 209 $  SDEF (boolean, _core_file_matches_executable_p, (bfd *, bfd *));
 210
 211 Archive entry points
 212
 213 $ SDEF (boolean, _bfd_slurp_armap, (bfd *));
 214 $ SDEF (boolean, _bfd_slurp_extended_name_table, (bfd *));
 215 $ SDEF (void,   _bfd_truncate_arname, (bfd *, CONST char *, char *));
 216 $ SDEF (boolean, write_armap, (bfd *arch,
 217 $                              unsigned int elength,
 218 $                              struct orl *map,
 219 $                              unsigned int orl_count,
 220 $                              int stridx));
 221
 222 Standard stuff.
 223
 224 $  SDEF (boolean, _close_and_cleanup, (bfd *));
 225 $  SDEF (boolean, _bfd_set_section_contents, (bfd *, sec_ptr, PTR,
 226 $                                            file_ptr, bfd_size_type));
 227 $  SDEF (boolean, _bfd_get_section_contents, (bfd *, sec_ptr, PTR,
 228 $                                            file_ptr, bfd_size_type));
 229 $  SDEF (boolean, _new_section_hook, (bfd *, sec_ptr));
 230
 231 Symbols and reloctions
 232
 233 $ SDEF (unsigned int, _get_symtab_upper_bound, (bfd *));
 234 $  SDEF (unsigned int, _bfd_canonicalize_symtab,
 235 $           (bfd *, struct symbol_cache_entry **));
 236 $  SDEF (unsigned int, _get_reloc_upper_bound, (bfd *, sec_ptr));
 237 $  SDEF (unsigned int, _bfd_canonicalize_reloc, (bfd *, sec_ptr, arelent **,
 238 $                                               struct symbol_cache_entry**));
 239 $  SDEF (struct symbol_cache_entry  *, _bfd_make_empty_symbol, (bfd *));
 240 $  SDEF (void,     _bfd_print_symbol, (bfd *, PTR, struct symbol_cache_entry  *,
 241 $                                      bfd_print_symbol_type));
 242 $#define bfd_print_symbol(b,p,s,e) BFD_SEND(b, _bfd_print_symbol, (b,p,s,e))
 243 $  SDEF (alent *,   _get_lineno, (bfd *, struct symbol_cache_entry  *));
 244 $
 245 $  SDEF (boolean,   _bfd_set_arch_mach, (bfd *, enum bfd_architecture,
 246 $                                       unsigned long));
 247 $
 248 $  SDEF (bfd *,  openr_next_archived_file, (bfd *arch, bfd *prev));
 249 $  SDEF (boolean, _bfd_find_nearest_line,
 250 $        (bfd *abfd, struct sec  *section,
 251 $         struct symbol_cache_entry  **symbols,bfd_vma offset,
 252 $        CONST char **file, CONST char **func, unsigned int *line));
 253 $  SDEF (int,    _bfd_stat_arch_elt, (bfd *, struct stat *));
 254 $
 255 $  SDEF (int,    _bfd_sizeof_headers, (bfd *, boolean));
 256 $
 257 $  SDEF (void, _bfd_debug_info_start, (bfd *));
 258 $  SDEF (void, _bfd_debug_info_end, (bfd *));
 259 $  SDEF (void, _bfd_debug_info_accumulate, (bfd *, struct sec  *));
 260
 261 Special entry points for gdb to swap in coff symbol table parts
 262
 263 $  SDEF(void, _bfd_coff_swap_aux_in,(
 264 $       bfd            *abfd ,
 265 $       PTR             ext,
 266 $       int             type,
 267 $       int             class ,
 268 $       PTR             in));
 269 $
 270 $  SDEF(void, _bfd_coff_swap_sym_in,(
 271 $       bfd            *abfd ,
 272 $       PTR             ext,
 273 $       PTR             in));
 274 $
 275 $  SDEF(void, _bfd_coff_swap_lineno_in,  (
 276 $       bfd            *abfd,
 277 $       PTR            ext,
 278 $       PTR             in));
 279 $
 280
 281 Special entry points for gas to swap coff parts
 282
 283 $ SDEF(unsigned int, _bfd_coff_swap_aux_out,(
 284 $       bfd     *abfd,
 285 $       PTR     in,
 286 $       int     type,
 287 $       int     class,
 288 $       PTR     ext));
 289 $
 290 $ SDEF(unsigned int, _bfd_coff_swap_sym_out,(
 291 $      bfd      *abfd,
 292 $      PTR      in,
 293 $      PTR      ext));
 294 $
 295 $ SDEF(unsigned int, _bfd_coff_swap_lineno_out,(
 296 $       bfd     *abfd,
 297 $       PTR     in,
 298 $       PTR     ext));
 299 $
 300 $ SDEF(unsigned int, _bfd_coff_swap_reloc_out,(
 301 $       bfd     *abfd,
 302 $       PTR     src,
 303 $       PTR     dst));
 304 $
 305 $ SDEF(unsigned int, _bfd_coff_swap_filehdr_out,(
 306 $       bfd     *abfd,
 307 $       PTR     in,
 308 $       PTR     out));
 309 $
 310 $ SDEF(unsigned int, _bfd_coff_swap_aouthdr_out,(
 311 $       bfd     *abfd,
 312 $       PTR     in,
 313 $       PTR     out));
 314 $
 315 $ SDEF(unsigned int, _bfd_coff_swap_scnhdr_out,(
 316 $       bfd     *abfd,
 317 $       PTR     in,
 318 $       PTR     out));
 319 $
 320 $} bfd_target;
 321
 322 *---
 323
 324 */
 325 extern bfd_target ecoff_little_vec;
 326 extern bfd_target ecoff_big_vec;
 327 extern bfd_target sunos_big_vec;
 328 extern bfd_target demo_64_vec;
 329 extern bfd_target srec_vec;
 330 extern bfd_target b_out_vec_little_host;
 331 extern bfd_target b_out_vec_big_host;
 332 extern bfd_target icoff_little_vec;
 333 extern bfd_target icoff_big_vec;
 334 extern bfd_target elf_little_vec;
 335 extern bfd_target elf_big_vec;
 336 extern bfd_target ieee_vec;
 337 extern bfd_target oasys_vec;
 338 extern bfd_target m88k_bcs_vec;
 339 extern bfd_target m68kcoff_vec;
 340 extern bfd_target i386coff_vec;
 341 extern bfd_target i386aout_vec;
 342 extern bfd_target a29kcoff_big_vec;
 343 extern bfd_target trad_core_vec;
 344 extern bfd_target rs6000coff_vec;
 345
 346 #ifdef SELECT_VECS
 347
 348 bfd_target *target_vector[] = {
 349 SELECT_VECS,
 350 0
 351
 352 };
 353 #else
 354 #ifdef DEFAULT_VECTOR
 355 extern bfd_target DEFAULT_VECTOR;
 356 #endif
 357
 358 #ifdef GNU960
 359 #define ICOFF_LITTLE_VEC        icoff_little_vec
 360 #define ICOFF_BIG_VEC           icoff_big_vec
 361 #define B_OUT_VEC_LITTLE_HOST   b_out_vec_little_host
 362 #define B_OUT_VEC_BIG_HOST      b_out_vec_big_host
 363 #endif /* GNU960 */
 364
 365 #ifndef RESTRICTED
 366 #define ECOFF_LITTLE_VEC        ecoff_little_vec
 367 #define ECOFF_BIG_VEC           ecoff_big_vec
 368 #define ICOFF_LITTLE_VEC        icoff_little_vec
 369 #define ICOFF_BIG_VEC           icoff_big_vec
 370 #define ELF_LITTLE_VEC          elf_little_vec
 371 #define ELF_BIG_VEC             elf_big_vec
 372 #define ZB_OUT_VEC_LITTLE_HOST  b_out_vec_little_host
 373 #define ZB_OUT_VEC_BIG_HOST     b_out_vec_big_host
 374 #define SUNOS_VEC_BIG_HOST      sunos_big_vec
 375 #define DEMO_64_VEC             demo_64_vec
 376
 377 /* We have no oasys tools anymore, so we can't test any of this
 378    anymore. If you want to test the stuff yourself, go ahead...
 379    steve@cygnus.com */
 380 #if 0
 381 #define OASYS_VEC               oasys_vec
 382 #endif
 383
 384 #define IEEE_VEC                ieee_vec
 385 #define M88K_BCS_VEC            m88k_bcs_vec
 386 #define SREC_VEC                srec_vec
 387 #define M68KCOFF_VEC            m68kcoff_vec
 388 #define I386COFF_VEC            i386coff_vec
 389 #define I386AOUT_VEC            i386aout_vec
 390 #define A29KCOFF_BIG_VEC        a29kcoff_big_vec
 391 #define RS6000COFF_VEC          rs6000coff_vec
 392 #endif
 393
 394 bfd_target *target_vector[] = {
 395
 396 #ifdef DEFAULT_VECTOR
 397         &DEFAULT_VECTOR,
 398 #endif
 399
 400 #ifdef  I386COFF_VEC
 401         &I386COFF_VEC,
 402 #endif
 403
 404 #ifdef  I386AOUT_VEC
 405         &I386AOUT_VEC,
 406 #endif
 407
 408 #ifdef ECOFF_LITTLE_VEC
 409         &ECOFF_LITTLE_VEC,
 410 #endif
 411
 412 #ifdef ECOFF_BIG_VEC
 413         &ECOFF_BIG_VEC,
 414 #endif
 415
 416 #ifdef IEEE_VEC
 417         &IEEE_VEC,
 418 #endif
 419
 420 #ifdef OASYS_VEC
 421         &OASYS_VEC,
 422 #endif
 423
 424 #ifdef SUNOS_VEC_BIG_HOST
 425         &SUNOS_VEC_BIG_HOST,
 426 #endif
 427
 428 #ifdef HOST_64_BIT
 429 #ifdef DEMO_64_VEC
 430         &DEMO_64_VEC,
 431 #endif
 432 #endif
 433
 434 #ifdef M88K_BCS_VEC
 435         &M88K_BCS_VEC,
 436 #endif
 437
 438 #ifdef SREC_VEC
 439         &SREC_VEC,
 440 #endif
 441
 442 #ifdef ICOFF_LITTLE_VEC
 443         &ICOFF_LITTLE_VEC,
 444 #endif
 445
 446 #ifdef ICOFF_BIG_VEC
 447         &ICOFF_BIG_VEC,
 448 #endif
 449
 450 #ifdef ELF_LITTLE_VEC
 451         &ELF_LITTLE_VEC,
 452 #endif
 453
 454 #ifdef ELF_BIG_VEC
 455         &ELF_BIG_VEC,
 456 #endif
 457
 458 #ifdef B_OUT_VEC_LITTLE_HOST
 459         &B_OUT_VEC_LITTLE_HOST,
 460 #endif
 461
 462 #ifdef B_OUT_VEC_BIG_HOST
 463         &B_OUT_VEC_BIG_HOST,
 464 #endif
 465
 466 #ifdef  M68KCOFF_VEC
 467         &M68KCOFF_VEC,
 468 #endif
 469
 470 #ifdef  A29KCOFF_BIG_VEC
 471         &A29KCOFF_BIG_VEC,
 472 #endif
 473
 474 #ifdef  TRAD_CORE
 475         &trad_core_vec,
 476 #endif
 477
 478 #ifdef  RS6000COFF_VEC
 479         &RS6000COFF_VEC,
 480 #endif
 481
 482         NULL, /* end of list marker */
 483 };
 484
 485 #endif
 486
 487 /* default_vector[0] contains either the address of the default vector,
 488    if there is one, or zero if there isn't.  */
 489
 490 bfd_target *default_vector[] = {
 491 #ifdef DEFAULT_VECTOR
 492         &DEFAULT_VECTOR,
 493 #endif
 494         0,
 495 };
 496
 497
 498
 499
 500 /*proto*
 501 *i bfd_find_target
 502 Returns a pointer to the transfer vector for the object target
 503 named target_name.  If target_name is NULL, chooses the one in the
 504 environment variable GNUTARGET; if that is null or not defined then
 505 the first entry in the target list is chosen.  Passing in the
 506 string "default" or setting the environment variable to "default"
 507 will cause the first entry in the target list to be returned,
 508 and "target_defaulted" will be set in the BFD.  This causes
 509 @code{bfd_check_format} to loop over all the targets to find the one
 510 that matches the file being read.
 511 *; PROTO(bfd_target *, bfd_find_target,(CONST char *, bfd *));
 512 *-*/
 513
 514 bfd_target *
 515 DEFUN(bfd_find_target,(target_name, abfd),
 516       CONST char *target_name AND
 517       bfd *abfd)
 518 {
 519   bfd_target **target;
 520   extern char *getenv ();
 521   CONST char *targname = (target_name ? target_name : getenv ("GNUTARGET"));
 522
 523   /* This is safe; the vector cannot be null */
 524   if (targname == NULL || !strcmp (targname, "default")) {
 525     abfd->target_defaulted = true;
 526     return abfd->xvec = target_vector[0];
 527   }
 528
 529   abfd->target_defaulted = false;
 530
 531   for (target = &target_vector[0]; *target != NULL; target++) {
 532     if (!strcmp (targname, (*target)->name))
 533       return abfd->xvec = *target;
 534   }
 535
 536   bfd_error = invalid_target;
 537   return NULL;
 538 }
 539
 540
 541 /*proto*
 542 *i bfd_target_list
 543 This function returns a freshly malloced NULL-terminated vector of the
 544 names of all the valid BFD targets. Do not modify the names
 545 *; PROTO(CONST char **,bfd_target_list,());
 546
 547 *-*/
 548
 549 CONST char **
 550 DEFUN_VOID(bfd_target_list)
 551 {
 552   int vec_length= 0;
 553   bfd_target **target;
 554   CONST  char **name_list, **name_ptr;
 555
 556   for (target = &target_vector[0]; *target != NULL; target++)
 557     vec_length++;
 558
 559   name_ptr =
 560     name_list = (CONST char **) zalloc ((vec_length + 1) * sizeof (char **));
 561
 562   if (name_list == NULL) {
 563     bfd_error = no_memory;
 564     return NULL;
 565   }
 566
 567   for (target = &target_vector[0]; *target != NULL; target++)
 568     *(name_ptr++) = (*target)->name;
 569
 570   return name_list;
 571 }