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 /*
  28 SECTION
  29         Targets
  30
  31 DESCRIPTION
  32         Each port of BFD to a different machine requries the creation
  33         of a target back end. All the back end provides to the root
  34         part of BFD is a structure containing pointers to functions
  35         which perform certain low level operations on files. BFD
  36         translates the applications's requests through a pointer into
  37         calls to the back end routines.
  38
  39         When a file is opened with <<bfd_openr>>, its format and
  40         target are unknown. BFD uses various mechanisms to determine
  41         how to interpret the file. The operations performed are:
  42
  43         o First a BFD is created by calling the internal routine
  44         <<new_bfd>>, then <<bfd_find_target>> is called with the
  45         target string supplied to <<bfd_openr>> and the new BFD pointer.
  46
  47         o If a null target string was provided to <<bfd_find_target>>,
  48         it looks up the environment variable <<GNUTARGET>> and uses
  49         that as the target string.
  50
  51         o If the target string is still NULL, or the target string is
  52         <<default>>, then the first item in the target vector is used
  53         as the target type. @xref{bfd_target}.
  54
  55         o Otherwise, the elements in the target vector are inspected
  56         one by one, until a match on target name is found. When found,
  57         that is used.
  58
  59         o Otherwise the error <<invalid_target>> is returned to
  60         <<bfd_openr>>.
  61
  62         o <<bfd_openr>> attempts to open the file using
  63         <<bfd_open_file>>, and returns the BFD.
  64
  65         Once the BFD has been opened and the target selected, the file
  66         format may be determined. This is done by calling
  67         <<bfd_check_format>> on the BFD with a suggested format. The
  68         routine returns <<true>> when the application guesses right.
  69 @menu
  70 @* bfd_target::
  71 @end menu
  72 */
  73
  74
  75 /*
  76
  77 INODE
  78         bfd_target,  , Targets, Targets
  79
  80 SUBSECTION
  81         bfd_target
  82
  83 DESCRIPTION
  84         This structure contains everything that BFD knows about a
  85         target. It includes things like its byte order, name, what
  86         routines to call to do various operations, etc.
  87
  88         Every BFD points to a target structure with its <<xvec>>
  89         member.
  90
  91         Shortcut for declaring fields which are prototyped function
  92         pointers, while avoiding anguish on compilers that don't
  93         support protos.
  94
  95 .#define SDEF(ret, name, arglist) \
  96 .                PROTO(ret,(*name),arglist)
  97 .#define SDEF_FMT(ret, name, arglist) \
  98 .                PROTO(ret,(*name[bfd_type_end]),arglist)
  99
 100         These macros are used to dispatch to functions through the
 101         bfd_target vector. They are used in a number of macros further
 102         down in @file{bfd.h}, and are also used when calling various
 103         routines by hand inside the BFD implementation.  The "arglist"
 104         argument must be parenthesized; it contains all the arguments
 105         to the called function.
 106
 107
 108 .#define BFD_SEND(bfd, message, arglist) \
 109 .               ((*((bfd)->xvec->message)) arglist)
 110
 111         For operations which index on the BFD format
 112
 113 .#define BFD_SEND_FMT(bfd, message, arglist) \
 114 .            (((bfd)->xvec->message[(int)((bfd)->format)]) arglist)
 115
 116         This is the struct which defines the type of BFD this is.  The
 117         <<xvec>> member of the struct <<bfd>> itself points here.  Each
 118         module that implements access to a different target under BFD,
 119         defines one of these.
 120
 121
 122         FIXME, these names should be rationalised with the names of
 123         the entry points which call them. Too bad we can't have one
 124         macro to define them both!
 125
 126 .typedef struct bfd_target
 127 .{
 128
 129 identifies the kind of target, eg SunOS4, Ultrix, etc
 130
 131 .  char *name;
 132
 133 The "flavour" of a back end is a general indication about the contents
 134 of a file.
 135
 136 .  enum target_flavour {
 137 .    bfd_target_unknown_flavour,
 138 .    bfd_target_aout_flavour,
 139 .    bfd_target_coff_flavour,
 140 .    bfd_target_elf_flavour,
 141 .    bfd_target_ieee_flavour,
 142 .    bfd_target_oasys_flavour,
 143 .    bfd_target_srec_flavour} flavour;
 144
 145 The order of bytes within the data area of a file.
 146
 147 .  boolean byteorder_big_p;
 148
 149 The order of bytes within the header parts of a file.
 150
 151 .  boolean header_byteorder_big_p;
 152
 153 This is a mask of all the flags which an executable may have set -
 154 from the set <<NO_FLAGS>>, <<HAS_RELOC>>, ...<<D_PAGED>>.
 155
 156 .  flagword object_flags;
 157
 158 This is a mask of all the flags which a section may have set - from
 159 the set <<SEC_NO_FLAGS>>, <<SEC_ALLOC>>, ...<<SET_NEVER_LOAD>>.
 160
 161 .  flagword section_flags;
 162
 163 The pad character for filenames within an archive header.
 164
 165 .  char ar_pad_char;
 166
 167 The maximum number of characters in an archive header.
 168
 169 . unsigned short ar_max_namelen;
 170
 171 The minimum alignment restriction for any section.
 172
 173 .  unsigned int align_power_min;
 174
 175 Entries for byte swapping for data. These are different to the other
 176 entry points, since they don't take BFD as first arg.  Certain other handlers
 177 could do the same.
 178
 179 .  SDEF (bfd_vma,      bfd_getx64, (bfd_byte *));
 180 .  SDEF (void,         bfd_putx64, (bfd_vma, bfd_byte *));
 181 .  SDEF (bfd_vma, bfd_getx32, (bfd_byte *));
 182 .  SDEF (void,         bfd_putx32, (bfd_vma, bfd_byte *));
 183 .  SDEF (bfd_vma, bfd_getx16, (bfd_byte *));
 184 .  SDEF (void,         bfd_putx16, (bfd_vma, bfd_byte *));
 185
 186 Byte swapping for the headers
 187
 188 .  SDEF (bfd_vma,   bfd_h_getx64, (bfd_byte *));
 189 .  SDEF (void,          bfd_h_putx64, (bfd_vma, bfd_byte *));
 190 .  SDEF (bfd_vma,  bfd_h_getx32, (bfd_byte *));
 191 .  SDEF (void,          bfd_h_putx32, (bfd_vma, bfd_byte *));
 192 .  SDEF (bfd_vma,  bfd_h_getx16, (bfd_byte *));
 193 .  SDEF (void,          bfd_h_putx16, (bfd_vma, bfd_byte *));
 194
 195 Format dependent routines, these turn into vectors of entry points
 196 within the target vector structure; one for each format to check.
 197
 198 Check the format of a file being read.  Return bfd_target * or zero.
 199
 200 .  SDEF_FMT (struct bfd_target *, _bfd_check_format, (bfd *));
 201
 202 Set the format of a file being written.
 203
 204 .  SDEF_FMT (boolean,            _bfd_set_format, (bfd *));
 205
 206 Write cached information into a file being written, at bfd_close.
 207
 208 .  SDEF_FMT (boolean,            _bfd_write_contents, (bfd *));
 209
 210 The following functions are defined in <<JUMP_TABLE>>. The idea is
 211 that the back end writer of <<foo>> names all the routines
 212 <<foo_>>@var{entry_point}, <<JUMP_TABLE>> will built the entries
 213 in this structure in the right order.
 214
 215 Core file entry points
 216
 217 .  SDEF (char *, _core_file_failing_command, (bfd *));
 218 .  SDEF (int,    _core_file_failing_signal, (bfd *));
 219 .  SDEF (boolean, _core_file_matches_executable_p, (bfd *, bfd *));
 220
 221 Archive entry points
 222
 223 . SDEF (boolean, _bfd_slurp_armap, (bfd *));
 224 . SDEF (boolean, _bfd_slurp_extended_name_table, (bfd *));
 225 . SDEF (void,   _bfd_truncate_arname, (bfd *, CONST char *, char *));
 226 . SDEF (boolean, write_armap, (bfd *arch,
 227 .                              unsigned int elength,
 228 .                              struct orl *map,
 229 .                              unsigned int orl_count,
 230 .                              int stridx));
 231
 232 Standard stuff.
 233
 234 .  SDEF (boolean, _close_and_cleanup, (bfd *));
 235 .  SDEF (boolean, _bfd_set_section_contents, (bfd *, sec_ptr, PTR,
 236 .                                            file_ptr, bfd_size_type));
 237 .  SDEF (boolean, _bfd_get_section_contents, (bfd *, sec_ptr, PTR,
 238 .                                            file_ptr, bfd_size_type));
 239 .  SDEF (boolean, _new_section_hook, (bfd *, sec_ptr));
 240
 241 Symbols and reloctions
 242
 243 .  SDEF (unsigned int, _get_symtab_upper_bound, (bfd *));
 244 .  SDEF (unsigned int, _bfd_canonicalize_symtab,
 245 .           (bfd *, struct symbol_cache_entry **));
 246 .  SDEF (unsigned int, _get_reloc_upper_bound, (bfd *, sec_ptr));
 247 .  SDEF (unsigned int, _bfd_canonicalize_reloc, (bfd *, sec_ptr, arelent **,
 248 .                                               struct symbol_cache_entry**));
 249 .  SDEF (struct symbol_cache_entry  *, _bfd_make_empty_symbol, (bfd *));
 250 .  SDEF (void,     _bfd_print_symbol, (bfd *, PTR, struct symbol_cache_entry  *,
 251 .                                      bfd_print_symbol_type));
 252 .#define bfd_print_symbol(b,p,s,e) BFD_SEND(b, _bfd_print_symbol, (b,p,s,e))
 253 .  SDEF (alent *,   _get_lineno, (bfd *, struct symbol_cache_entry  *));
 254 .
 255 .  SDEF (boolean,   _bfd_set_arch_mach, (bfd *, enum bfd_architecture,
 256 .                                       unsigned long));
 257 .
 258 .  SDEF (bfd *,  openr_next_archived_file, (bfd *arch, bfd *prev));
 259 .  SDEF (boolean, _bfd_find_nearest_line,
 260 .        (bfd *abfd, struct sec  *section,
 261 .         struct symbol_cache_entry  **symbols,bfd_vma offset,
 262 .        CONST char **file, CONST char **func, unsigned int *line));
 263 .  SDEF (int,    _bfd_stat_arch_elt, (bfd *, struct stat *));
 264 .
 265 .  SDEF (int,    _bfd_sizeof_headers, (bfd *, boolean));
 266 .
 267 .  SDEF (void, _bfd_debug_info_start, (bfd *));
 268 .  SDEF (void, _bfd_debug_info_end, (bfd *));
 269 .  SDEF (void, _bfd_debug_info_accumulate, (bfd *, struct sec  *));
 270 .  SDEF (bfd_byte *, _bfd_get_relocated_section_contents, (bfd*,struct bfd_seclet_struct *));
 271
 272 Special entry points for gdb to swap in coff symbol table parts
 273
 274 .  SDEF(void, _bfd_coff_swap_aux_in,(
 275 .       bfd            *abfd ,
 276 .       PTR             ext,
 277 .       int             type,
 278 .       int             class ,
 279 .       PTR             in));
 280 .
 281 .  SDEF(void, _bfd_coff_swap_sym_in,(
 282 .       bfd            *abfd ,
 283 .       PTR             ext,
 284 .       PTR             in));
 285 .
 286 .  SDEF(void, _bfd_coff_swap_lineno_in,  (
 287 .       bfd            *abfd,
 288 .       PTR            ext,
 289 .       PTR             in));
 290 .
 291
 292 Special entry points for gas to swap coff parts
 293
 294 . SDEF(unsigned int, _bfd_coff_swap_aux_out,(
 295 .       bfd     *abfd,
 296 .       PTR     in,
 297 .       int     type,
 298 .       int     class,
 299 .       PTR     ext));
 300 .
 301 . SDEF(unsigned int, _bfd_coff_swap_sym_out,(
 302 .      bfd      *abfd,
 303 .      PTR      in,
 304 .      PTR      ext));
 305 .
 306 . SDEF(unsigned int, _bfd_coff_swap_lineno_out,(
 307 .       bfd     *abfd,
 308 .       PTR     in,
 309 .       PTR     ext));
 310 .
 311 . SDEF(unsigned int, _bfd_coff_swap_reloc_out,(
 312 .       bfd     *abfd,
 313 .       PTR     src,
 314 .       PTR     dst));
 315 .
 316 . SDEF(unsigned int, _bfd_coff_swap_filehdr_out,(
 317 .       bfd     *abfd,
 318 .       PTR     in,
 319 .       PTR     out));
 320 .
 321 . SDEF(unsigned int, _bfd_coff_swap_aouthdr_out,(
 322 .       bfd     *abfd,
 323 .       PTR     in,
 324 .       PTR     out));
 325 .
 326 . SDEF(unsigned int, _bfd_coff_swap_scnhdr_out,(
 327 .       bfd     *abfd,
 328 .       PTR     in,
 329 .       PTR     out));
 330 .
 331 .} bfd_target;
 332
 333 */
 334
 335 /* The default is to define a target_vector containing all the targets.
 336    By setting MINIMIZE=1 on the "make" command line, the user can change this
 337    to a vector containing just DEFAULT_VECTOR and any required
 338    traditional-core-file handler.  (This is to save space in the executables.)
 339    The config files can also override the default large vector by giving an
 340    explicit SELECT_VECS macro.  */
 341
 342 #if MINIMIZE && defined(DEFAULT_VECTOR) && !defined(SELECT_VECS)
 343 #ifdef TRAD_CORE
 344 #define SELECT_VECS &DEFAULT_VECTOR,&trad_core_vec
 345 #else
 346 #define SELECT_VECS &DEFAULT_VECTOR
 347 #endif
 348 #endif
 349
 350 /* All known xvecs.  They are listed a second time below, since
 351    we can't intermix extern's and initializers.  */
 352 extern bfd_target ecoff_little_vec;
 353 extern bfd_target ecoff_big_vec;
 354 extern bfd_target sunos_big_vec;
 355 extern bfd_target demo_64_vec;
 356 extern bfd_target srec_vec;
 357 extern bfd_target b_out_vec_little_host;
 358 extern bfd_target b_out_vec_big_host;
 359 extern bfd_target icoff_little_vec;
 360 extern bfd_target icoff_big_vec;
 361 extern bfd_target elf_little_vec;
 362 extern bfd_target elf_big_vec;
 363 extern bfd_target ieee_vec;
 364 extern bfd_target oasys_vec;
 365 extern bfd_target m88kbcs_vec;
 366 extern bfd_target m68kcoff_vec;
 367 extern bfd_target i386coff_vec;
 368 extern bfd_target i386aout_vec;
 369 extern bfd_target a29kcoff_big_vec;
 370 extern bfd_target trad_core_vec;
 371 extern bfd_target rs6000coff_vec;
 372 extern bfd_target h8300coff_vec;
 373
 374 #ifdef DEFAULT_VECTOR
 375 extern bfd_target DEFAULT_VECTOR;
 376 #endif
 377
 378 #ifdef SELECT_VECS
 379
 380 bfd_target *target_vector[] = {
 381         SELECT_VECS,
 382         0
 383 };
 384
 385 #else
 386
 387 bfd_target *target_vector[] = {
 388
 389 #ifdef DEFAULT_VECTOR
 390         &DEFAULT_VECTOR,
 391 #endif
 392
 393         &i386coff_vec,
 394         &i386aout_vec,
 395         &ecoff_little_vec,
 396         &ecoff_big_vec,
 397         &ieee_vec,
 398 #if 0
 399         /* We have no oasys tools anymore, so we can't test any of this
 400            anymore. If you want to test the stuff yourself, go ahead...
 401            steve@cygnus.com */
 402         &oasys_vec,
 403 #endif
 404         &sunos_big_vec,
 405 #ifdef HOST_64_BIT
 406         &demo_64_vec,   /* Only compiled if host has long-long support */
 407 #endif
 408         &h8300coff_vec,
 409         &m88kbcs_vec,
 410         &srec_vec,
 411         &icoff_little_vec,
 412         &icoff_big_vec,
 413         &elf_little_vec,
 414         &elf_big_vec,
 415         &b_out_vec_little_host,
 416         &b_out_vec_big_host,
 417         &m68kcoff_vec,
 418         &a29kcoff_big_vec,
 419         &rs6000coff_vec,
 420
 421 #ifdef  TRAD_CORE
 422         &trad_core_vec,
 423 #endif
 424         NULL, /* end of list marker */
 425 };
 426
 427 #endif
 428
 429 /* default_vector[0] contains either the address of the default vector,
 430    if there is one, or zero if there isn't.  */
 431
 432 bfd_target *default_vector[] = {
 433 #ifdef DEFAULT_VECTOR
 434         &DEFAULT_VECTOR,
 435 #endif
 436         0,
 437 };
 438
 439
 440
 441
 442 /*
 443 FUNCTION
 444         bfd_find_target
 445
 446 DESCRIPTION
 447         Returns a pointer to the transfer vector for the object target
 448         named target_name.  If target_name is NULL, chooses the one in
 449         the environment variable GNUTARGET; if that is null or not
 450         defined thenthe first entry in the target list is chosen.
 451         Passing in the string "default" or setting the environment
 452         variable to "default" will cause the first entry in the target
 453         list to be returned, and "target_defaulted" will be set in the
 454         BFD.  This causes <<bfd_check_format>> to loop over all the
 455         targets to find the one that matches the file being read.
 456
 457 SYNOPSIS
 458         bfd_target *bfd_find_target(CONST char *, bfd *);
 459 */
 460
 461 bfd_target *
 462 DEFUN(bfd_find_target,(target_name, abfd),
 463       CONST char *target_name AND
 464       bfd *abfd)
 465 {
 466   bfd_target **target;
 467   extern char *getenv ();
 468   CONST char *targname = (target_name ? target_name :
 469                           (CONST char *) 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 /*
 490 FUNCTION
 491         bfd_target_list
 492
 493 DESCRIPTION
 494         This function returns a freshly malloced NULL-terminated
 495         vector of the names of all the valid BFD targets. Do not
 496         modify the names
 497
 498 SYNOPSIS
 499         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 }