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
 326 /* The default is to define a target_vector containing just the
 327    DEFAULT_TARGET.  (This is to save space in the executables.)
 328    You can override this by giving an explicit target_vector using
 329    the SELECT_VECTOR macro.
 330    Or define ALL_TARGETS macro to get all of the available targets. */
 331
 332
 333 #if MINIMIZE && defined(DEFAULT_VECTOR) && !defined(SELECT_VECS)
 334 #ifdef TRAD_CORE
 335 #define SELECT_VECS &DEFAULT_VECTOR,&trad_core_vec
 336 #else
 337 #define SELECT_VECS &DEFAULT_VECTOR
 338 #endif
 339 #endif
 340
 341 extern bfd_target ecoff_little_vec;
 342 extern bfd_target ecoff_big_vec;
 343 extern bfd_target sunos_big_vec;
 344 extern bfd_target demo_64_vec;
 345 extern bfd_target srec_vec;
 346 extern bfd_target b_out_vec_little_host;
 347 extern bfd_target b_out_vec_big_host;
 348 extern bfd_target icoff_little_vec;
 349 extern bfd_target icoff_big_vec;
 350 extern bfd_target elf_little_vec;
 351 extern bfd_target elf_big_vec;
 352 extern bfd_target ieee_vec;
 353 extern bfd_target oasys_vec;
 354 extern bfd_target m88kbcs_vec;
 355 extern bfd_target m68kcoff_vec;
 356 extern bfd_target i386coff_vec;
 357 extern bfd_target i386aout_vec;
 358 extern bfd_target a29kcoff_big_vec;
 359 extern bfd_target trad_core_vec;
 360 extern bfd_target rs6000coff_vec;
 361 extern bfd_target h8300coff_vec;
 362
 363 #ifdef DEFAULT_VECTOR
 364 extern bfd_target DEFAULT_VECTOR;
 365 #endif
 366
 367 #ifdef SELECT_VECS
 368
 369 bfd_target *target_vector[] = {
 370 SELECT_VECS,
 371 0
 372
 373 };
 374 #else
 375
 376 #ifdef GNU960
 377 #define ICOFF_LITTLE_VEC        icoff_little_vec
 378 #define ICOFF_BIG_VEC           icoff_big_vec
 379 #define B_OUT_VEC_LITTLE_HOST   b_out_vec_little_host
 380 #define B_OUT_VEC_BIG_HOST      b_out_vec_big_host
 381 #endif /* GNU960 */
 382
 383 #ifndef RESTRICTED
 384 #define ECOFF_LITTLE_VEC        ecoff_little_vec
 385 #define ECOFF_BIG_VEC           ecoff_big_vec
 386 #define ICOFF_LITTLE_VEC        icoff_little_vec
 387 #define ICOFF_BIG_VEC           icoff_big_vec
 388 #define ELF_LITTLE_VEC          elf_little_vec
 389 #define ELF_BIG_VEC             elf_big_vec
 390 #define ZB_OUT_VEC_LITTLE_HOST  b_out_vec_little_host
 391 #define ZB_OUT_VEC_BIG_HOST     b_out_vec_big_host
 392 #define SUNOS_VEC_BIG_HOST      sunos_big_vec
 393 #define DEMO_64_VEC             demo_64_vec
 394
 395 /* We have no oasys tools anymore, so we can't test any of this
 396    anymore. If you want to test the stuff yourself, go ahead...
 397    steve@cygnus.com */
 398 #if 0
 399 #define OASYS_VEC               oasys_vec
 400 #endif
 401
 402 #define IEEE_VEC                ieee_vec
 403 #define M88KBCS_VEC            m88kbcs_vec
 404 #define SREC_VEC                srec_vec
 405 #define M68KCOFF_VEC            m68kcoff_vec
 406 #define I386COFF_VEC            i386coff_vec
 407 #define I386AOUT_VEC            i386aout_vec
 408 #define A29KCOFF_BIG_VEC        a29kcoff_big_vec
 409 #define RS6000COFF_VEC          rs6000coff_vec
 410 #define H8300COFF_VEC           h8300coff_vec
 411 #endif
 412
 413 bfd_target *target_vector[] = {
 414
 415 #ifdef DEFAULT_VECTOR
 416         &DEFAULT_VECTOR,
 417 #endif
 418
 419 #ifdef  I386COFF_VEC
 420         &I386COFF_VEC,
 421 #endif
 422
 423 #ifdef  I386AOUT_VEC
 424         &I386AOUT_VEC,
 425 #endif
 426
 427 #ifdef ECOFF_LITTLE_VEC
 428         &ECOFF_LITTLE_VEC,
 429 #endif
 430
 431 #ifdef ECOFF_BIG_VEC
 432         &ECOFF_BIG_VEC,
 433 #endif
 434
 435 #ifdef IEEE_VEC
 436         &IEEE_VEC,
 437 #endif
 438
 439 #ifdef OASYS_VEC
 440         &OASYS_VEC,
 441 #endif
 442
 443 #ifdef SUNOS_VEC_BIG_HOST
 444         &SUNOS_VEC_BIG_HOST,
 445 #endif
 446
 447 #ifdef HOST_64_BIT
 448 #ifdef DEMO_64_VEC
 449         &DEMO_64_VEC,
 450 #endif
 451 #endif
 452
 453 #ifdef H300COFF_VEC
 454         &h8300coff_vec,
 455 #endif
 456 #ifdef M88KBCS_VEC
 457         &M88KBCS_VEC,
 458 #endif
 459
 460 #ifdef SREC_VEC
 461         &SREC_VEC,
 462 #endif
 463
 464 #ifdef ICOFF_LITTLE_VEC
 465         &ICOFF_LITTLE_VEC,
 466 #endif
 467
 468 #ifdef ICOFF_BIG_VEC
 469         &ICOFF_BIG_VEC,
 470 #endif
 471
 472 #ifdef ELF_LITTLE_VEC
 473         &ELF_LITTLE_VEC,
 474 #endif
 475
 476 #ifdef ELF_BIG_VEC
 477         &ELF_BIG_VEC,
 478 #endif
 479
 480 #ifdef B_OUT_VEC_LITTLE_HOST
 481         &B_OUT_VEC_LITTLE_HOST,
 482 #endif
 483
 484 #ifdef B_OUT_VEC_BIG_HOST
 485         &B_OUT_VEC_BIG_HOST,
 486 #endif
 487
 488 #ifdef  M68KCOFF_VEC
 489         &M68KCOFF_VEC,
 490 #endif
 491
 492 #ifdef  A29KCOFF_BIG_VEC
 493         &A29KCOFF_BIG_VEC,
 494 #endif
 495
 496 #ifdef  TRAD_CORE
 497         &trad_core_vec,
 498 #endif
 499
 500 #ifdef  RS6000COFF_VEC
 501         &RS6000COFF_VEC,
 502 #endif
 503
 504         NULL, /* end of list marker */
 505 };
 506
 507 #endif
 508
 509 /* default_vector[0] contains either the address of the default vector,
 510    if there is one, or zero if there isn't.  */
 511
 512 bfd_target *default_vector[] = {
 513 #ifdef DEFAULT_VECTOR
 514         &DEFAULT_VECTOR,
 515 #endif
 516         0,
 517 };
 518
 519
 520
 521
 522 /*proto*
 523 *i bfd_find_target
 524 Returns a pointer to the transfer vector for the object target
 525 named target_name.  If target_name is NULL, chooses the one in the
 526 environment variable GNUTARGET; if that is null or not defined then
 527 the first entry in the target list is chosen.  Passing in the
 528 string "default" or setting the environment variable to "default"
 529 will cause the first entry in the target list to be returned,
 530 and "target_defaulted" will be set in the BFD.  This causes
 531 @code{bfd_check_format} to loop over all the targets to find the one
 532 that matches the file being read.
 533 *; PROTO(bfd_target *, bfd_find_target,(CONST char *, bfd *));
 534 *-*/
 535
 536 bfd_target *
 537 DEFUN(bfd_find_target,(target_name, abfd),
 538       CONST char *target_name AND
 539       bfd *abfd)
 540 {
 541   bfd_target **target;
 542   extern char *getenv ();
 543   CONST char *targname = (target_name ? target_name :
 544                           (CONST char *) getenv ("GNUTARGET"));
 545
 546   /* This is safe; the vector cannot be null */
 547   if (targname == NULL || !strcmp (targname, "default")) {
 548     abfd->target_defaulted = true;
 549     return abfd->xvec = target_vector[0];
 550   }
 551
 552   abfd->target_defaulted = false;
 553
 554   for (target = &target_vector[0]; *target != NULL; target++) {
 555     if (!strcmp (targname, (*target)->name))
 556       return abfd->xvec = *target;
 557   }
 558
 559   bfd_error = invalid_target;
 560   return NULL;
 561 }
 562
 563
 564 /*proto*
 565 *i bfd_target_list
 566 This function returns a freshly malloced NULL-terminated vector of the
 567 names of all the valid BFD targets. Do not modify the names
 568 *; PROTO(CONST char **,bfd_target_list,());
 569
 570 *-*/
 571
 572 CONST char **
 573 DEFUN_VOID(bfd_target_list)
 574 {
 575   int vec_length= 0;
 576   bfd_target **target;
 577   CONST  char **name_list, **name_ptr;
 578
 579   for (target = &target_vector[0]; *target != NULL; target++)
 580     vec_length++;
 581
 582   name_ptr =
 583     name_list = (CONST char **) zalloc ((vec_length + 1) * sizeof (char **));
 584
 585   if (name_list == NULL) {
 586     bfd_error = no_memory;
 587     return NULL;
 588   }
 589
 590   for (target = &target_vector[0]; *target != NULL; target++)
 591     *(name_ptr++) = (*target)->name;
 592
 593   return name_list;
 594 }