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         They make the documentation (more) unpleasant to read, so if
 108         someone wants to fix this and not break the above, please do.
 109
 110 .#define BFD_SEND(bfd, message, arglist) \
 111 .               ((*((bfd)->xvec->message)) arglist)
 112
 113         For operations which index on the BFD format
 114
 115 .#define BFD_SEND_FMT(bfd, message, arglist) \
 116 .            (((bfd)->xvec->message[(int)((bfd)->format)]) arglist)
 117
 118         This is the struct which defines the type of BFD this is.  The
 119         <<xvec>> member of the struct <<bfd>> itself points here.  Each
 120         module that implements access to a different target under BFD,
 121         defines one of these.
 122
 123
 124         FIXME, these names should be rationalised with the names of
 125         the entry points which call them. Too bad we can't have one
 126         macro to define them both!
 127
 128 .typedef struct bfd_target
 129 .{
 130
 131 Identifies the kind of target, eg SunOS4, Ultrix, etc.
 132
 133 .  char *name;
 134
 135 The "flavour" of a back end is a general indication about the contents
 136 of a file.
 137
 138 .  enum target_flavour {
 139 .    bfd_target_unknown_flavour,
 140 .    bfd_target_aout_flavour,
 141 .    bfd_target_coff_flavour,
 142 .    bfd_target_elf_flavour,
 143 .    bfd_target_ieee_flavour,
 144 .    bfd_target_oasys_flavour,
 145 .    bfd_target_tekhex_flavour,
 146 .    bfd_target_srec_flavour} flavour;
 147
 148 The order of bytes within the data area of a file.
 149
 150 .  boolean byteorder_big_p;
 151
 152 The order of bytes within the header parts of a file.
 153
 154 .  boolean header_byteorder_big_p;
 155
 156 This is a mask of all the flags which an executable may have set -
 157 from the set <<NO_FLAGS>>, <<HAS_RELOC>>, ...<<D_PAGED>>.
 158
 159 .  flagword object_flags;
 160
 161 This is a mask of all the flags which a section may have set - from
 162 the set <<SEC_NO_FLAGS>>, <<SEC_ALLOC>>, ...<<SET_NEVER_LOAD>>.
 163
 164 .  flagword section_flags;
 165
 166 The pad character for filenames within an archive header.
 167
 168 .  char ar_pad_char;
 169
 170 The maximum number of characters in an archive header.
 171
 172 . unsigned short ar_max_namelen;
 173
 174 The minimum alignment restriction for any section.
 175
 176 .  unsigned int align_power_min;
 177
 178 Entries for byte swapping for data. These are different to the other
 179 entry points, since they don't take BFD as first arg.  Certain other handlers
 180 could do the same.
 181
 182 .  SDEF (bfd_vma,      bfd_getx64, (bfd_byte *));
 183 .  SDEF (void,         bfd_putx64, (bfd_vma, bfd_byte *));
 184 .  SDEF (bfd_vma, bfd_getx32, (bfd_byte *));
 185 .  SDEF (void,         bfd_putx32, (bfd_vma, bfd_byte *));
 186 .  SDEF (bfd_vma, bfd_getx16, (bfd_byte *));
 187 .  SDEF (void,         bfd_putx16, (bfd_vma, bfd_byte *));
 188
 189 Byte swapping for the headers
 190
 191 .  SDEF (bfd_vma,   bfd_h_getx64, (bfd_byte *));
 192 .  SDEF (void,          bfd_h_putx64, (bfd_vma, bfd_byte *));
 193 .  SDEF (bfd_vma,  bfd_h_getx32, (bfd_byte *));
 194 .  SDEF (void,          bfd_h_putx32, (bfd_vma, bfd_byte *));
 195 .  SDEF (bfd_vma,  bfd_h_getx16, (bfd_byte *));
 196 .  SDEF (void,          bfd_h_putx16, (bfd_vma, bfd_byte *));
 197
 198 Format dependent routines, these turn into vectors of entry points
 199 within the target vector structure; one for each format to check.
 200
 201 Check the format of a file being read.  Return bfd_target * or zero.
 202
 203 .  SDEF_FMT (struct bfd_target *, _bfd_check_format, (bfd *));
 204
 205 Set the format of a file being written.
 206
 207 .  SDEF_FMT (boolean,            _bfd_set_format, (bfd *));
 208
 209 Write cached information into a file being written, at bfd_close.
 210
 211 .  SDEF_FMT (boolean,            _bfd_write_contents, (bfd *));
 212
 213 The following functions are defined in <<JUMP_TABLE>>. The idea is
 214 that the back end writer of <<foo>> names all the routines
 215 <<foo_>>@var{entry_point}, <<JUMP_TABLE>> will built the entries
 216 in this structure in the right order.
 217
 218 Core file entry points
 219
 220 .  SDEF (char *, _core_file_failing_command, (bfd *));
 221 .  SDEF (int,    _core_file_failing_signal, (bfd *));
 222 .  SDEF (boolean, _core_file_matches_executable_p, (bfd *, bfd *));
 223
 224 Archive entry points
 225
 226 . SDEF (boolean, _bfd_slurp_armap, (bfd *));
 227 . SDEF (boolean, _bfd_slurp_extended_name_table, (bfd *));
 228 . SDEF (void,   _bfd_truncate_arname, (bfd *, CONST char *, char *));
 229 . SDEF (boolean, write_armap, (bfd *arch,
 230 .                              unsigned int elength,
 231 .                              struct orl *map,
 232 .                              unsigned int orl_count,
 233 .                              int stridx));
 234
 235 Standard stuff.
 236
 237 .  SDEF (boolean, _close_and_cleanup, (bfd *));
 238 .  SDEF (boolean, _bfd_set_section_contents, (bfd *, sec_ptr, PTR,
 239 .                                            file_ptr, bfd_size_type));
 240 .  SDEF (boolean, _bfd_get_section_contents, (bfd *, sec_ptr, PTR,
 241 .                                            file_ptr, bfd_size_type));
 242 .  SDEF (boolean, _new_section_hook, (bfd *, sec_ptr));
 243
 244 Symbols and relocations
 245
 246 .  SDEF (unsigned int, _get_symtab_upper_bound, (bfd *));
 247 .  SDEF (unsigned int, _bfd_canonicalize_symtab,
 248 .           (bfd *, struct symbol_cache_entry **));
 249 .  SDEF (unsigned int, _get_reloc_upper_bound, (bfd *, sec_ptr));
 250 .  SDEF (unsigned int, _bfd_canonicalize_reloc, (bfd *, sec_ptr, arelent **,
 251 .                                               struct symbol_cache_entry**));
 252 .  SDEF (struct symbol_cache_entry  *, _bfd_make_empty_symbol, (bfd *));
 253 .  SDEF (void,     _bfd_print_symbol, (bfd *, PTR, struct symbol_cache_entry  *,
 254 .                                      bfd_print_symbol_type));
 255 .#define bfd_print_symbol(b,p,s,e) BFD_SEND(b, _bfd_print_symbol, (b,p,s,e))
 256 .  SDEF (alent *,   _get_lineno, (bfd *, struct symbol_cache_entry  *));
 257 .
 258 .  SDEF (boolean,   _bfd_set_arch_mach, (bfd *, enum bfd_architecture,
 259 .                                       unsigned long));
 260 .
 261 .  SDEF (bfd *,  openr_next_archived_file, (bfd *arch, bfd *prev));
 262 .  SDEF (boolean, _bfd_find_nearest_line,
 263 .        (bfd *abfd, struct sec  *section,
 264 .         struct symbol_cache_entry  **symbols,bfd_vma offset,
 265 .        CONST char **file, CONST char **func, unsigned int *line));
 266 .  SDEF (int,    _bfd_stat_arch_elt, (bfd *, struct stat *));
 267 .
 268 .  SDEF (int,    _bfd_sizeof_headers, (bfd *, boolean));
 269 .
 270 .  SDEF (void, _bfd_debug_info_start, (bfd *));
 271 .  SDEF (void, _bfd_debug_info_end, (bfd *));
 272 .  SDEF (void, _bfd_debug_info_accumulate, (bfd *, struct sec  *));
 273 .  SDEF (bfd_byte *, _bfd_get_relocated_section_contents, (bfd*,struct bfd_seclet_struct *, bfd_byte *data));
 274 .  SDEF (boolean,_bfd_relax_section,(bfd *, struct sec *, struct symbol_cache_entry **));
 275 Special entry points for gdb to swap in coff symbol table parts
 276
 277 .  SDEF(void, _bfd_coff_swap_aux_in,(
 278 .       bfd            *abfd ,
 279 .       PTR             ext,
 280 .       int             type,
 281 .       int             class ,
 282 .       PTR             in));
 283 .
 284 .  SDEF(void, _bfd_coff_swap_sym_in,(
 285 .       bfd            *abfd ,
 286 .       PTR             ext,
 287 .       PTR             in));
 288 .
 289 .  SDEF(void, _bfd_coff_swap_lineno_in,  (
 290 .       bfd            *abfd,
 291 .       PTR            ext,
 292 .       PTR             in));
 293 .
 294
 295 Special entry points for gas to swap coff parts
 296
 297 . SDEF(unsigned int, _bfd_coff_swap_aux_out,(
 298 .       bfd     *abfd,
 299 .       PTR     in,
 300 .       int     type,
 301 .       int     class,
 302 .       PTR     ext));
 303 .
 304 . SDEF(unsigned int, _bfd_coff_swap_sym_out,(
 305 .      bfd      *abfd,
 306 .      PTR      in,
 307 .      PTR      ext));
 308 .
 309 . SDEF(unsigned int, _bfd_coff_swap_lineno_out,(
 310 .       bfd     *abfd,
 311 .       PTR     in,
 312 .       PTR     ext));
 313 .
 314 . SDEF(unsigned int, _bfd_coff_swap_reloc_out,(
 315 .       bfd     *abfd,
 316 .       PTR     src,
 317 .       PTR     dst));
 318 .
 319 . SDEF(unsigned int, _bfd_coff_swap_filehdr_out,(
 320 .       bfd     *abfd,
 321 .       PTR     in,
 322 .       PTR     out));
 323 .
 324 . SDEF(unsigned int, _bfd_coff_swap_aouthdr_out,(
 325 .       bfd     *abfd,
 326 .       PTR     in,
 327 .       PTR     out));
 328 .
 329 . SDEF(unsigned int, _bfd_coff_swap_scnhdr_out,(
 330 .       bfd     *abfd,
 331 .       PTR     in,
 332 .       PTR     out));
 333 .
 334 . {* See documentation on reloc types.  *}
 335 . SDEF (CONST struct reloc_howto_struct *,
 336 .       reloc_type_lookup,
 337 .       (bfd *abfd, bfd_reloc_code_type code));
 338 .
 339 . {* Complete and utter crock, currently used for the assembler
 340 .    when creating COFF files.  *}
 341 . SDEF (asymbol *, _bfd_make_debug_symbol, (
 342 .       bfd *abfd,
 343 .       void *ptr,
 344 .       unsigned long size));
 345
 346 Data for use by back-end routines; e.g., for a.out, includes whether
 347 this particular target maps ZMAGIC files contiguously or with text and
 348 data separated.  Could perhaps also be used to eliminate some of the
 349 above COFF-specific fields.
 350
 351 . PTR backend_data;
 352 .} bfd_target;
 353
 354 */
 355
 356 /* The default is to define a target_vector containing all the targets.
 357    By setting MINIMIZE=1 on the "make" command line, the user can change this
 358    to a vector containing just DEFAULT_VECTOR and any required
 359    traditional-core-file handler.  (This is to save space in the executables.)
 360    The config files can also override the default large vector by giving an
 361    explicit SELECT_VECS macro.  */
 362
 363 #if MINIMIZE && defined(DEFAULT_VECTOR) && !defined(SELECT_VECS)
 364 #ifdef TRAD_CORE
 365 #define SELECT_VECS &DEFAULT_VECTOR,&trad_core_vec
 366 #else
 367 #define SELECT_VECS &DEFAULT_VECTOR
 368 #endif
 369 #endif
 370
 371 /* All known xvecs.  They are listed a second time below, since
 372    we can't intermix extern's and initializers.  */
 373 extern bfd_target ecoff_little_vec;
 374 extern bfd_target ecoff_big_vec;
 375 extern bfd_target sunos_big_vec;
 376 extern bfd_target demo_64_vec;
 377 extern bfd_target srec_vec;
 378 extern bfd_target tekhex_vec;
 379 extern bfd_target b_out_vec_little_host;
 380 extern bfd_target b_out_vec_big_host;
 381 extern bfd_target icoff_little_vec;
 382 extern bfd_target icoff_big_vec;
 383 extern bfd_target elf_little_vec;
 384 extern bfd_target elf_big_vec;
 385 extern bfd_target ieee_vec;
 386 extern bfd_target oasys_vec;
 387 extern bfd_target m88kbcs_vec;
 388 extern bfd_target m68kcoff_vec;
 389 extern bfd_target i386coff_vec;
 390 extern bfd_target i386aout_vec;
 391 extern bfd_target a29kcoff_big_vec;
 392 extern bfd_target trad_core_vec;
 393 extern bfd_target rs6000coff_vec;
 394 extern bfd_target h8300coff_vec;
 395
 396 #ifdef DEFAULT_VECTOR
 397 extern bfd_target DEFAULT_VECTOR;
 398 #endif
 399
 400 #ifdef SELECT_VECS
 401
 402 bfd_target *target_vector[] = {
 403         SELECT_VECS,
 404         0
 405 };
 406
 407 #else
 408
 409 bfd_target *target_vector[] = {
 410
 411 #ifdef DEFAULT_VECTOR
 412         &DEFAULT_VECTOR,
 413 #endif
 414
 415         &i386coff_vec,
 416         &i386aout_vec,
 417         &ecoff_little_vec,
 418         &ecoff_big_vec,
 419         &ieee_vec,
 420 #if 1
 421         /* We have no oasys tools anymore, so we can't test any of this
 422            anymore. If you want to test the stuff yourself, go ahead...
 423            steve@cygnus.com */
 424         &oasys_vec,
 425 #endif
 426         &sunos_big_vec,
 427 #ifdef HOST_64_BIT
 428         &demo_64_vec,   /* Only compiled if host has long-long support */
 429 #endif
 430         &h8300coff_vec,
 431         &m88kbcs_vec,
 432         &srec_vec,
 433 /*      &tekhex_vec,*/
 434         &icoff_little_vec,
 435         &icoff_big_vec,
 436         &elf_little_vec,
 437         &elf_big_vec,
 438         &b_out_vec_little_host,
 439         &b_out_vec_big_host,
 440         &m68kcoff_vec,
 441         &a29kcoff_big_vec,
 442         &rs6000coff_vec,
 443
 444 #ifdef  TRAD_CORE
 445         &trad_core_vec,
 446 #endif
 447         NULL, /* end of list marker */
 448 };
 449
 450 #endif
 451
 452 /* default_vector[0] contains either the address of the default vector,
 453    if there is one, or zero if there isn't.  */
 454
 455 bfd_target *default_vector[] = {
 456 #ifdef DEFAULT_VECTOR
 457         &DEFAULT_VECTOR,
 458 #endif
 459         0,
 460 };
 461
 462
 463
 464
 465 /*
 466 FUNCTION
 467         bfd_find_target
 468
 469 DESCRIPTION
 470         Returns a pointer to the transfer vector for the object target
 471         named target_name.  If target_name is NULL, chooses the one in
 472         the environment variable GNUTARGET; if that is null or not
 473         defined thenthe first entry in the target list is chosen.
 474         Passing in the string "default" or setting the environment
 475         variable to "default" will cause the first entry in the target
 476         list to be returned, and "target_defaulted" will be set in the
 477         BFD.  This causes <<bfd_check_format>> to loop over all the
 478         targets to find the one that matches the file being read.
 479
 480 SYNOPSIS
 481         bfd_target *bfd_find_target(CONST char *, bfd *);
 482 */
 483
 484 bfd_target *
 485 DEFUN(bfd_find_target,(target_name, abfd),
 486       CONST char *target_name AND
 487       bfd *abfd)
 488 {
 489   bfd_target **target;
 490   extern char *getenv ();
 491   CONST char *targname = (target_name ? target_name :
 492                           (CONST char *) getenv ("GNUTARGET"));
 493
 494   /* This is safe; the vector cannot be null */
 495   if (targname == NULL || !strcmp (targname, "default")) {
 496     abfd->target_defaulted = true;
 497     return abfd->xvec = target_vector[0];
 498   }
 499
 500   abfd->target_defaulted = false;
 501
 502   for (target = &target_vector[0]; *target != NULL; target++) {
 503     if (!strcmp (targname, (*target)->name))
 504       return abfd->xvec = *target;
 505   }
 506
 507   bfd_error = invalid_target;
 508   return NULL;
 509 }
 510
 511
 512 /*
 513 FUNCTION
 514         bfd_target_list
 515
 516 DESCRIPTION
 517         This function returns a freshly malloced NULL-terminated
 518         vector of the names of all the valid BFD targets. Do not
 519         modify the names
 520
 521 SYNOPSIS
 522         CONST char **bfd_target_list(void);
 523
 524 */
 525
 526 CONST char **
 527 DEFUN_VOID(bfd_target_list)
 528 {
 529   int vec_length= 0;
 530   bfd_target **target;
 531   CONST  char **name_list, **name_ptr;
 532
 533   for (target = &target_vector[0]; *target != NULL; target++)
 534     vec_length++;
 535
 536   name_ptr =
 537     name_list = (CONST char **) zalloc ((vec_length + 1) * sizeof (char **));
 538
 539   if (name_list == NULL) {
 540     bfd_error = no_memory;
 541     return NULL;
 542   }
 543
 544   for (target = &target_vector[0]; *target != NULL; target++)
 545     *(name_ptr++) = (*target)->name;
 546
 547   return name_list;
 548 }