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_tekhex_flavour,
 144 .    bfd_target_srec_flavour} flavour;
 145
 146 The order of bytes within the data area of a file.
 147
 148 .  boolean byteorder_big_p;
 149
 150 The order of bytes within the header parts of a file.
 151
 152 .  boolean header_byteorder_big_p;
 153
 154 This is a mask of all the flags which an executable may have set -
 155 from the set <<NO_FLAGS>>, <<HAS_RELOC>>, ...<<D_PAGED>>.
 156
 157 .  flagword object_flags;
 158
 159 This is a mask of all the flags which a section may have set - from
 160 the set <<SEC_NO_FLAGS>>, <<SEC_ALLOC>>, ...<<SET_NEVER_LOAD>>.
 161
 162 .  flagword section_flags;
 163
 164 The pad character for filenames within an archive header.
 165
 166 .  char ar_pad_char;
 167
 168 The maximum number of characters in an archive header.
 169
 170 . unsigned short ar_max_namelen;
 171
 172 The minimum alignment restriction for any section.
 173
 174 .  unsigned int align_power_min;
 175
 176 Entries for byte swapping for data. These are different to the other
 177 entry points, since they don't take BFD as first arg.  Certain other handlers
 178 could do the same.
 179
 180 .  SDEF (bfd_vma,      bfd_getx64, (bfd_byte *));
 181 .  SDEF (void,         bfd_putx64, (bfd_vma, bfd_byte *));
 182 .  SDEF (bfd_vma, bfd_getx32, (bfd_byte *));
 183 .  SDEF (void,         bfd_putx32, (bfd_vma, bfd_byte *));
 184 .  SDEF (bfd_vma, bfd_getx16, (bfd_byte *));
 185 .  SDEF (void,         bfd_putx16, (bfd_vma, bfd_byte *));
 186
 187 Byte swapping for the headers
 188
 189 .  SDEF (bfd_vma,   bfd_h_getx64, (bfd_byte *));
 190 .  SDEF (void,          bfd_h_putx64, (bfd_vma, bfd_byte *));
 191 .  SDEF (bfd_vma,  bfd_h_getx32, (bfd_byte *));
 192 .  SDEF (void,          bfd_h_putx32, (bfd_vma, bfd_byte *));
 193 .  SDEF (bfd_vma,  bfd_h_getx16, (bfd_byte *));
 194 .  SDEF (void,          bfd_h_putx16, (bfd_vma, bfd_byte *));
 195
 196 Format dependent routines, these turn into vectors of entry points
 197 within the target vector structure; one for each format to check.
 198
 199 Check the format of a file being read.  Return bfd_target * or zero.
 200
 201 .  SDEF_FMT (struct bfd_target *, _bfd_check_format, (bfd *));
 202
 203 Set the format of a file being written.
 204
 205 .  SDEF_FMT (boolean,            _bfd_set_format, (bfd *));
 206
 207 Write cached information into a file being written, at bfd_close.
 208
 209 .  SDEF_FMT (boolean,            _bfd_write_contents, (bfd *));
 210
 211 The following functions are defined in <<JUMP_TABLE>>. The idea is
 212 that the back end writer of <<foo>> names all the routines
 213 <<foo_>>@var{entry_point}, <<JUMP_TABLE>> will built the entries
 214 in this structure in the right order.
 215
 216 Core file entry points
 217
 218 .  SDEF (char *, _core_file_failing_command, (bfd *));
 219 .  SDEF (int,    _core_file_failing_signal, (bfd *));
 220 .  SDEF (boolean, _core_file_matches_executable_p, (bfd *, bfd *));
 221
 222 Archive entry points
 223
 224 . SDEF (boolean, _bfd_slurp_armap, (bfd *));
 225 . SDEF (boolean, _bfd_slurp_extended_name_table, (bfd *));
 226 . SDEF (void,   _bfd_truncate_arname, (bfd *, CONST char *, char *));
 227 . SDEF (boolean, write_armap, (bfd *arch,
 228 .                              unsigned int elength,
 229 .                              struct orl *map,
 230 .                              unsigned int orl_count,
 231 .                              int stridx));
 232
 233 Standard stuff.
 234
 235 .  SDEF (boolean, _close_and_cleanup, (bfd *));
 236 .  SDEF (boolean, _bfd_set_section_contents, (bfd *, sec_ptr, PTR,
 237 .                                            file_ptr, bfd_size_type));
 238 .  SDEF (boolean, _bfd_get_section_contents, (bfd *, sec_ptr, PTR,
 239 .                                            file_ptr, bfd_size_type));
 240 .  SDEF (boolean, _new_section_hook, (bfd *, sec_ptr));
 241
 242 Symbols and reloctions
 243
 244 .  SDEF (unsigned int, _get_symtab_upper_bound, (bfd *));
 245 .  SDEF (unsigned int, _bfd_canonicalize_symtab,
 246 .           (bfd *, struct symbol_cache_entry **));
 247 .  SDEF (unsigned int, _get_reloc_upper_bound, (bfd *, sec_ptr));
 248 .  SDEF (unsigned int, _bfd_canonicalize_reloc, (bfd *, sec_ptr, arelent **,
 249 .                                               struct symbol_cache_entry**));
 250 .  SDEF (struct symbol_cache_entry  *, _bfd_make_empty_symbol, (bfd *));
 251 .  SDEF (void,     _bfd_print_symbol, (bfd *, PTR, struct symbol_cache_entry  *,
 252 .                                      bfd_print_symbol_type));
 253 .#define bfd_print_symbol(b,p,s,e) BFD_SEND(b, _bfd_print_symbol, (b,p,s,e))
 254 .  SDEF (alent *,   _get_lineno, (bfd *, struct symbol_cache_entry  *));
 255 .
 256 .  SDEF (boolean,   _bfd_set_arch_mach, (bfd *, enum bfd_architecture,
 257 .                                       unsigned long));
 258 .
 259 .  SDEF (bfd *,  openr_next_archived_file, (bfd *arch, bfd *prev));
 260 .  SDEF (boolean, _bfd_find_nearest_line,
 261 .        (bfd *abfd, struct sec  *section,
 262 .         struct symbol_cache_entry  **symbols,bfd_vma offset,
 263 .        CONST char **file, CONST char **func, unsigned int *line));
 264 .  SDEF (int,    _bfd_stat_arch_elt, (bfd *, struct stat *));
 265 .
 266 .  SDEF (int,    _bfd_sizeof_headers, (bfd *, boolean));
 267 .
 268 .  SDEF (void, _bfd_debug_info_start, (bfd *));
 269 .  SDEF (void, _bfd_debug_info_end, (bfd *));
 270 .  SDEF (void, _bfd_debug_info_accumulate, (bfd *, struct sec  *));
 271 .  SDEF (bfd_byte *, _bfd_get_relocated_section_contents, (bfd*,struct bfd_seclet_struct *));
 272 .  SDEF (boolean,_bfd_relax_section,(bfd *, struct sec *, struct symbol_cache_entry **));
 273 Special entry points for gdb to swap in coff symbol table parts
 274
 275 .  SDEF(void, _bfd_coff_swap_aux_in,(
 276 .       bfd            *abfd ,
 277 .       PTR             ext,
 278 .       int             type,
 279 .       int             class ,
 280 .       PTR             in));
 281 .
 282 .  SDEF(void, _bfd_coff_swap_sym_in,(
 283 .       bfd            *abfd ,
 284 .       PTR             ext,
 285 .       PTR             in));
 286 .
 287 .  SDEF(void, _bfd_coff_swap_lineno_in,  (
 288 .       bfd            *abfd,
 289 .       PTR            ext,
 290 .       PTR             in));
 291 .
 292
 293 Special entry points for gas to swap coff parts
 294
 295 . SDEF(unsigned int, _bfd_coff_swap_aux_out,(
 296 .       bfd     *abfd,
 297 .       PTR     in,
 298 .       int     type,
 299 .       int     class,
 300 .       PTR     ext));
 301 .
 302 . SDEF(unsigned int, _bfd_coff_swap_sym_out,(
 303 .      bfd      *abfd,
 304 .      PTR      in,
 305 .      PTR      ext));
 306 .
 307 . SDEF(unsigned int, _bfd_coff_swap_lineno_out,(
 308 .       bfd     *abfd,
 309 .       PTR     in,
 310 .       PTR     ext));
 311 .
 312 . SDEF(unsigned int, _bfd_coff_swap_reloc_out,(
 313 .       bfd     *abfd,
 314 .       PTR     src,
 315 .       PTR     dst));
 316 .
 317 . SDEF(unsigned int, _bfd_coff_swap_filehdr_out,(
 318 .       bfd     *abfd,
 319 .       PTR     in,
 320 .       PTR     out));
 321 .
 322 . SDEF(unsigned int, _bfd_coff_swap_aouthdr_out,(
 323 .       bfd     *abfd,
 324 .       PTR     in,
 325 .       PTR     out));
 326 .
 327 . SDEF(unsigned int, _bfd_coff_swap_scnhdr_out,(
 328 .       bfd     *abfd,
 329 .       PTR     in,
 330 .       PTR     out));
 331 .
 332 .} bfd_target;
 333
 334 */
 335
 336 /* The default is to define a target_vector containing all the targets.
 337    By setting MINIMIZE=1 on the "make" command line, the user can change this
 338    to a vector containing just DEFAULT_VECTOR and any required
 339    traditional-core-file handler.  (This is to save space in the executables.)
 340    The config files can also override the default large vector by giving an
 341    explicit SELECT_VECS macro.  */
 342
 343 #if MINIMIZE && defined(DEFAULT_VECTOR) && !defined(SELECT_VECS)
 344 #ifdef TRAD_CORE
 345 #define SELECT_VECS &DEFAULT_VECTOR,&trad_core_vec
 346 #else
 347 #define SELECT_VECS &DEFAULT_VECTOR
 348 #endif
 349 #endif
 350
 351 /* All known xvecs.  They are listed a second time below, since
 352    we can't intermix extern's and initializers.  */
 353 extern bfd_target ecoff_little_vec;
 354 extern bfd_target ecoff_big_vec;
 355 extern bfd_target sunos_big_vec;
 356 extern bfd_target demo_64_vec;
 357 extern bfd_target srec_vec;
 358 extern bfd_target tekhex_vec;
 359 extern bfd_target b_out_vec_little_host;
 360 extern bfd_target b_out_vec_big_host;
 361 extern bfd_target icoff_little_vec;
 362 extern bfd_target icoff_big_vec;
 363 extern bfd_target elf_little_vec;
 364 extern bfd_target elf_big_vec;
 365 extern bfd_target ieee_vec;
 366 extern bfd_target oasys_vec;
 367 extern bfd_target m88kbcs_vec;
 368 extern bfd_target m68kcoff_vec;
 369 extern bfd_target i386coff_vec;
 370 extern bfd_target i386aout_vec;
 371 extern bfd_target a29kcoff_big_vec;
 372 extern bfd_target trad_core_vec;
 373 extern bfd_target rs6000coff_vec;
 374 extern bfd_target h8300coff_vec;
 375
 376 #ifdef DEFAULT_VECTOR
 377 extern bfd_target DEFAULT_VECTOR;
 378 #endif
 379
 380 #ifdef SELECT_VECS
 381
 382 bfd_target *target_vector[] = {
 383         SELECT_VECS,
 384         0
 385 };
 386
 387 #else
 388
 389 bfd_target *target_vector[] = {
 390
 391 #ifdef DEFAULT_VECTOR
 392         &DEFAULT_VECTOR,
 393 #endif
 394
 395         &i386coff_vec,
 396         &i386aout_vec,
 397         &ecoff_little_vec,
 398         &ecoff_big_vec,
 399         &ieee_vec,
 400 #if 0
 401         /* We have no oasys tools anymore, so we can't test any of this
 402            anymore. If you want to test the stuff yourself, go ahead...
 403            steve@cygnus.com */
 404         &oasys_vec,
 405 #endif
 406         &sunos_big_vec,
 407 #ifdef HOST_64_BIT
 408         &demo_64_vec,   /* Only compiled if host has long-long support */
 409 #endif
 410         &h8300coff_vec,
 411         &m88kbcs_vec,
 412         &srec_vec,
 413 /*      &tekhex_vec,*/
 414         &icoff_little_vec,
 415         &icoff_big_vec,
 416         &elf_little_vec,
 417         &elf_big_vec,
 418         &b_out_vec_little_host,
 419         &b_out_vec_big_host,
 420         &m68kcoff_vec,
 421         &a29kcoff_big_vec,
 422         &rs6000coff_vec,
 423
 424 #ifdef  TRAD_CORE
 425         &trad_core_vec,
 426 #endif
 427         NULL, /* end of list marker */
 428 };
 429
 430 #endif
 431
 432 /* default_vector[0] contains either the address of the default vector,
 433    if there is one, or zero if there isn't.  */
 434
 435 bfd_target *default_vector[] = {
 436 #ifdef DEFAULT_VECTOR
 437         &DEFAULT_VECTOR,
 438 #endif
 439         0,
 440 };
 441
 442
 443
 444
 445 /*
 446 FUNCTION
 447         bfd_find_target
 448
 449 DESCRIPTION
 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
 452         the environment variable GNUTARGET; if that is null or not
 453         defined thenthe first entry in the target list is chosen.
 454         Passing in the string "default" or setting the environment
 455         variable to "default" will cause the first entry in the target
 456         list to be returned, and "target_defaulted" will be set in the
 457         BFD.  This causes <<bfd_check_format>> to loop over all the
 458         targets to find the one that matches the file being read.
 459
 460 SYNOPSIS
 461         bfd_target *bfd_find_target(CONST char *, bfd *);
 462 */
 463
 464 bfd_target *
 465 DEFUN(bfd_find_target,(target_name, abfd),
 466       CONST char *target_name AND
 467       bfd *abfd)
 468 {
 469   bfd_target **target;
 470   extern char *getenv ();
 471   CONST char *targname = (target_name ? target_name :
 472                           (CONST char *) getenv ("GNUTARGET"));
 473
 474   /* This is safe; the vector cannot be null */
 475   if (targname == NULL || !strcmp (targname, "default")) {
 476     abfd->target_defaulted = true;
 477     return abfd->xvec = target_vector[0];
 478   }
 479
 480   abfd->target_defaulted = false;
 481
 482   for (target = &target_vector[0]; *target != NULL; target++) {
 483     if (!strcmp (targname, (*target)->name))
 484       return abfd->xvec = *target;
 485   }
 486
 487   bfd_error = invalid_target;
 488   return NULL;
 489 }
 490
 491
 492 /*
 493 FUNCTION
 494         bfd_target_list
 495
 496 DESCRIPTION
 497         This function returns a freshly malloced NULL-terminated
 498         vector of the names of all the valid BFD targets. Do not
 499         modify the names
 500
 501 SYNOPSIS
 502         CONST char **bfd_target_list(void);
 503
 504 */
 505
 506 CONST char **
 507 DEFUN_VOID(bfd_target_list)
 508 {
 509   int vec_length= 0;
 510   bfd_target **target;
 511   CONST  char **name_list, **name_ptr;
 512
 513   for (target = &target_vector[0]; *target != NULL; target++)
 514     vec_length++;
 515
 516   name_ptr =
 517     name_list = (CONST char **) zalloc ((vec_length + 1) * sizeof (char **));
 518
 519   if (name_list == NULL) {
 520     bfd_error = no_memory;
 521     return NULL;
 522   }
 523
 524   for (target = &target_vector[0]; *target != NULL; target++)
 525     *(name_ptr++) = (*target)->name;
 526
 527   return name_list;
 528 }