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 $                              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 $} bfd_target;
 281
 282 *---
 283
 284 */
 285 extern bfd_target ecoff_little_vec;
 286 extern bfd_target ecoff_big_vec;
 287 extern bfd_target sunos_big_vec;
 288 extern bfd_target demo_64_vec;
 289 extern bfd_target srec_vec;
 290 extern bfd_target b_out_vec_little_host;
 291 extern bfd_target b_out_vec_big_host;
 292 extern bfd_target icoff_little_vec;
 293 extern bfd_target icoff_big_vec;
 294 extern bfd_target elf_little_vec;
 295 extern bfd_target elf_big_vec;
 296 extern bfd_target ieee_vec;
 297 extern bfd_target oasys_vec;
 298 extern bfd_target m88k_bcs_vec;
 299 extern bfd_target m68kcoff_vec;
 300 extern bfd_target i386coff_vec;
 301 extern bfd_target i386aout_vec;
 302 extern bfd_target a29kcoff_big_vec;
 303
 304 #ifdef SELECT_VECS
 305
 306 bfd_target *target_vector[] = {
 307 SELECT_VECS,
 308 0
 309
 310 };
 311 #else
 312 #ifdef DEFAULT_VECTOR
 313 extern bfd_target DEFAULT_VECTOR;
 314 #endif
 315
 316 #ifdef GNU960
 317 #define ICOFF_LITTLE_VEC        icoff_little_vec
 318 #define ICOFF_BIG_VEC           icoff_big_vec
 319 #define B_OUT_VEC_LITTLE_HOST   b_out_vec_little_host
 320 #define B_OUT_VEC_BIG_HOST      b_out_vec_big_host
 321 #endif /* GNU960 */
 322
 323 #ifndef RESTRICTED
 324 #define ECOFF_LITTLE_VEC        ecoff_little_vec
 325 #define ECOFF_BIG_VEC           ecoff_big_vec
 326 #define ICOFF_LITTLE_VEC        icoff_little_vec
 327 #define ICOFF_BIG_VEC           icoff_big_vec
 328 #define ELF_LITTLE_VEC          elf_little_vec
 329 #define ELF_BIG_VEC             elf_big_vec
 330 #define ZB_OUT_VEC_LITTLE_HOST  b_out_vec_little_host
 331 #define ZB_OUT_VEC_BIG_HOST     b_out_vec_big_host
 332 #define SUNOS_VEC_BIG_HOST      sunos_big_vec
 333 #define DEMO_64_VEC             demo_64_vec
 334
 335 /* We have no oasys tools anymore, so we can't test any of this
 336    anymore. If you want to test the stuff yourself, go ahead...
 337    steve@cygnus.com */
 338 #if 0
 339 #define OASYS_VEC               oasys_vec
 340 #endif
 341
 342 #define IEEE_VEC                ieee_vec
 343 #define M88K_BCS_VEC            m88k_bcs_vec
 344 #define SREC_VEC                srec_vec
 345 #define M68KCOFF_VEC            m68kcoff_vec
 346 #define I386COFF_VEC            i386coff_vec
 347 #define I386AOUT_VEC            i386aout_vec
 348 #define A29KCOFF_BIG_VEC        a29kcoff_big_vec
 349 #endif
 350
 351 bfd_target *target_vector[] = {
 352
 353 #ifdef DEFAULT_VECTOR
 354         &DEFAULT_VECTOR,
 355 #endif
 356
 357 #ifdef  I386COFF_VEC
 358         &I386COFF_VEC,
 359 #endif
 360
 361 #ifdef  I386AOUT_VEC
 362         &I386AOUT_VEC,
 363 #endif
 364
 365 #ifdef ECOFF_LITTLE_VEC
 366         &ECOFF_LITTLE_VEC,
 367 #endif
 368
 369 #ifdef ECOFF_BIG_VEC
 370         &ECOFF_BIG_VEC,
 371 #endif
 372
 373 #ifdef IEEE_VEC
 374         &IEEE_VEC,
 375 #endif
 376
 377 #ifdef OASYS_VEC
 378         &OASYS_VEC,
 379 #endif
 380
 381 #ifdef SUNOS_VEC_BIG_HOST
 382         &SUNOS_VEC_BIG_HOST,
 383 #endif
 384
 385 #ifdef HOST_64_BIT
 386 #ifdef DEMO_64_VEC
 387         &DEMO_64_VEC,
 388 #endif
 389 #endif
 390
 391 #ifdef M88K_BCS_VEC
 392         &M88K_BCS_VEC,
 393 #endif
 394
 395 #ifdef SREC_VEC
 396         &SREC_VEC,
 397 #endif
 398
 399 #ifdef ICOFF_LITTLE_VEC
 400         &ICOFF_LITTLE_VEC,
 401 #endif
 402
 403 #ifdef ICOFF_BIG_VEC
 404         &ICOFF_BIG_VEC,
 405 #endif
 406
 407 #ifdef ELF_LITTLE_VEC
 408         &ELF_LITTLE_VEC,
 409 #endif
 410
 411 #ifdef ELF_BIG_VEC
 412         &ELF_BIG_VEC,
 413 #endif
 414
 415 #ifdef B_OUT_VEC_LITTLE_HOST
 416         &B_OUT_VEC_LITTLE_HOST,
 417 #endif
 418
 419 #ifdef B_OUT_VEC_BIG_HOST
 420         &B_OUT_VEC_BIG_HOST,
 421 #endif
 422
 423 #ifdef  M68KCOFF_VEC
 424         &M68KCOFF_VEC,
 425 #endif
 426
 427 #ifdef  A29KCOFF_BIG_VEC
 428         &A29KCOFF_BIG_VEC,
 429 #endif
 430
 431 #ifdef  TRAD_CORE
 432         &trad_core_big_vec,
 433         &trad_core_little_vec,
 434 #endif
 435
 436         NULL, /* end of list marker */
 437 };
 438
 439 #endif
 440
 441 /* default_vector[0] contains either the address of the default vector,
 442    if there is one, or zero if there isn't.  */
 443
 444 bfd_target *default_vector[] = {
 445 #ifdef DEFAULT_VECTOR
 446         &DEFAULT_VECTOR,
 447 #endif
 448         0,
 449 };
 450
 451
 452
 453
 454 /*proto*
 455 *i bfd_find_target
 456 Returns a pointer to the transfer vector for the object target
 457 named target_name.  If target_name is NULL, chooses the one in the
 458 environment variable GNUTARGET; if that is null or not defined then
 459 the first entry in the target list is chosen.  Passing in the
 460 string "default" or setting the environment variable to "default"
 461 will cause the first entry in the target list to be returned,
 462 and "target_defaulted" will be set in the BFD.  This causes
 463 @code{bfd_check_format} to loop over all the targets to find the one
 464 that matches the file being read.
 465 *; PROTO(bfd_target *, bfd_find_target,(CONST char *, bfd *));
 466 *-*/
 467
 468 bfd_target *
 469 DEFUN(bfd_find_target,(target_name, abfd),
 470       CONST char *target_name AND
 471       bfd *abfd)
 472 {
 473   bfd_target **target;
 474   extern char *getenv ();
 475   CONST char *targname = (target_name ? target_name : getenv ("GNUTARGET"));
 476
 477   /* This is safe; the vector cannot be null */
 478   if (targname == NULL || !strcmp (targname, "default")) {
 479     abfd->target_defaulted = true;
 480     return abfd->xvec = target_vector[0];
 481   }
 482
 483   abfd->target_defaulted = false;
 484
 485   for (target = &target_vector[0]; *target != NULL; target++) {
 486     if (!strcmp (targname, (*target)->name))
 487       return abfd->xvec = *target;
 488   }
 489
 490   bfd_error = invalid_target;
 491   return NULL;
 492 }
 493
 494
 495 /*proto*
 496 *i bfd_target_list
 497 This function returns a freshly malloced NULL-terminated vector of the
 498 names of all the valid BFD targets. Do not modify the names
 499 *; PROTO(CONST char **,bfd_target_list,());
 500
 501 *-*/
 502
 503 CONST char **
 504 DEFUN_VOID(bfd_target_list)
 505 {
 506   int vec_length= 0;
 507   bfd_target **target;
 508   CONST  char **name_list, **name_ptr;
 509
 510   for (target = &target_vector[0]; *target != NULL; target++)
 511     vec_length++;
 512
 513   name_ptr =
 514     name_list = (CONST char **) zalloc ((vec_length + 1) * sizeof (char **));
 515
 516   if (name_list == NULL) {
 517     bfd_error = no_memory;
 518     return NULL;
 519   }
 520
 521   for (target = &target_vector[0]; *target != NULL; target++)
 522     *(name_ptr++) = (*target)->name;
 523
 524   return name_list;
 525 }