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