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 #include "bfd.h"
  22 #include "sysdep.h"
  23 #include "libbfd.h"
  24
  25 /*
  26 SECTION
  27         Targets
  28
  29 DESCRIPTION
  30         Each port of BFD to a different machine requries the creation
  31         of a target back end. All the back end provides to the root
  32         part of BFD is a structure containing pointers to functions
  33         which perform certain low level operations on files. BFD
  34         translates the applications's requests through a pointer into
  35         calls to the back end routines.
  36
  37         When a file is opened with <<bfd_openr>>, its format and
  38         target are unknown. BFD uses various mechanisms to determine
  39         how to interpret the file. The operations performed are:
  40
  41         o First a BFD is created by calling the internal routine
  42         <<new_bfd>>, then <<bfd_find_target>> is called with the
  43         target string supplied to <<bfd_openr>> and the new BFD pointer.
  44
  45         o If a null target string was provided to <<bfd_find_target>>,
  46         it looks up the environment variable <<GNUTARGET>> and uses
  47         that as the target string.
  48
  49         o If the target string is still NULL, or the target string is
  50         <<default>>, then the first item in the target vector is used
  51         as the target type. @xref{bfd_target}.
  52
  53         o Otherwise, the elements in the target vector are inspected
  54         one by one, until a match on target name is found. When found,
  55         that is used.
  56
  57         o Otherwise the error <<invalid_target>> is returned to
  58         <<bfd_openr>>.
  59
  60         o <<bfd_openr>> attempts to open the file using
  61         <<bfd_open_file>>, and returns the BFD.
  62
  63         Once the BFD has been opened and the target selected, the file
  64         format may be determined. This is done by calling
  65         <<bfd_check_format>> on the BFD with a suggested format. The
  66         routine returns <<true>> when the application guesses right.
  67 @menu
  68 @* bfd_target::
  69 @end menu
  70 */
  71
  72
  73 /*
  74
  75 INODE
  76         bfd_target,  , Targets, Targets
  77 DOCDD
  78 SUBSECTION
  79         bfd_target
  80
  81 DESCRIPTION
  82         This structure contains everything that BFD knows about a
  83         target. It includes things like its byte order, name, what
  84         routines to call to do various operations, etc.
  85
  86         Every BFD points to a target structure with its <<xvec>>
  87         member.
  88
  89         Shortcut for declaring fields which are prototyped function
  90         pointers, while avoiding anguish on compilers that don't
  91         support protos.
  92
  93 .#define SDEF(ret, name, arglist) \
  94 .                PROTO(ret,(*name),arglist)
  95 .#define SDEF_FMT(ret, name, arglist) \
  96 .                PROTO(ret,(*name[bfd_type_end]),arglist)
  97
  98         These macros are used to dispatch to functions through the
  99         bfd_target vector. They are used in a number of macros further
 100         down in @file{bfd.h}, and are also used when calling various
 101         routines by hand inside the BFD implementation.  The "arglist"
 102         argument must be parenthesized; it contains all the arguments
 103         to the called function.
 104
 105         They make the documentation (more) unpleasant to read, so if
 106         someone wants to fix this and not break the above, please do.
 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,
 145 .    bfd_target_hppa_flavour} flavour;
 146
 147 The order of bytes within the data area of a file.
 148
 149 .  boolean byteorder_big_p;
 150
 151 The order of bytes within the header parts of a file.
 152
 153 .  boolean header_byteorder_big_p;
 154
 155 This is a mask of all the flags which an executable may have set -
 156 from the set <<NO_FLAGS>>, <<HAS_RELOC>>, ...<<D_PAGED>>.
 157
 158 .  flagword object_flags;
 159
 160 This is a mask of all the flags which a section may have set - from
 161 the set <<SEC_NO_FLAGS>>, <<SEC_ALLOC>>, ...<<SET_NEVER_LOAD>>.
 162
 163 .  flagword section_flags;
 164
 165 The pad character for filenames within an archive header.
 166
 167 .  char ar_pad_char;
 168
 169 The maximum number of characters in an archive header.
 170
 171 . unsigned short ar_max_namelen;
 172
 173 The minimum alignment restriction for any section.
 174
 175 .  unsigned int align_power_min;
 176
 177 Entries for byte swapping for data. These are different to the other
 178 entry points, since they don't take BFD as first arg.  Certain other handlers
 179 could do the same.
 180
 181 .  SDEF (bfd_vma,      bfd_getx64, (bfd_byte *));
 182 .  SDEF (void,         bfd_putx64, (bfd_vma, bfd_byte *));
 183 .  SDEF (bfd_vma, bfd_getx32, (bfd_byte *));
 184 .  SDEF (void,         bfd_putx32, (bfd_vma, bfd_byte *));
 185 .  SDEF (bfd_vma, bfd_getx16, (bfd_byte *));
 186 .  SDEF (void,         bfd_putx16, (bfd_vma, bfd_byte *));
 187
 188 Byte swapping for the headers
 189
 190 .  SDEF (bfd_vma,   bfd_h_getx64, (bfd_byte *));
 191 .  SDEF (void,          bfd_h_putx64, (bfd_vma, bfd_byte *));
 192 .  SDEF (bfd_vma,  bfd_h_getx32, (bfd_byte *));
 193 .  SDEF (void,          bfd_h_putx32, (bfd_vma, bfd_byte *));
 194 .  SDEF (bfd_vma,  bfd_h_getx16, (bfd_byte *));
 195 .  SDEF (void,          bfd_h_putx16, (bfd_vma, bfd_byte *));
 196
 197 Format dependent routines, these turn into vectors of entry points
 198 within the target vector structure; one for each format to check.
 199
 200 Check the format of a file being read.  Return bfd_target * or zero.
 201
 202 .  SDEF_FMT (struct bfd_target *, _bfd_check_format, (bfd *));
 203
 204 Set the format of a file being written.
 205
 206 .  SDEF_FMT (boolean,            _bfd_set_format, (bfd *));
 207
 208 Write cached information into a file being written, at bfd_close.
 209
 210 .  SDEF_FMT (boolean,            _bfd_write_contents, (bfd *));
 211
 212 The following functions are defined in <<JUMP_TABLE>>. The idea is
 213 that the back end writer of <<foo>> names all the routines
 214 <<foo_>>@var{entry_point}, <<JUMP_TABLE>> will built the entries
 215 in this structure in the right order.
 216
 217 Core file entry points
 218
 219 .  SDEF (char *, _core_file_failing_command, (bfd *));
 220 .  SDEF (int,    _core_file_failing_signal, (bfd *));
 221 .  SDEF (boolean, _core_file_matches_executable_p, (bfd *, bfd *));
 222
 223 Archive entry points
 224
 225 . SDEF (boolean, _bfd_slurp_armap, (bfd *));
 226 . SDEF (boolean, _bfd_slurp_extended_name_table, (bfd *));
 227 . SDEF (void,   _bfd_truncate_arname, (bfd *, CONST char *, char *));
 228 . SDEF (boolean, write_armap, (bfd *arch,
 229 .                              unsigned int elength,
 230 .                              struct orl *map,
 231 .                              unsigned int orl_count,
 232 .                              int stridx));
 233
 234 Standard stuff.
 235
 236 .  SDEF (boolean, _close_and_cleanup, (bfd *));
 237 .  SDEF (boolean, _bfd_set_section_contents, (bfd *, sec_ptr, PTR,
 238 .                                            file_ptr, bfd_size_type));
 239 .  SDEF (boolean, _bfd_get_section_contents, (bfd *, sec_ptr, PTR,
 240 .                                            file_ptr, bfd_size_type));
 241 .  SDEF (boolean, _new_section_hook, (bfd *, sec_ptr));
 242
 243 Symbols and relocations
 244
 245 .  SDEF (unsigned int, _get_symtab_upper_bound, (bfd *));
 246 .  SDEF (unsigned int, _bfd_canonicalize_symtab,
 247 .           (bfd *, struct symbol_cache_entry **));
 248 .  SDEF (unsigned int, _get_reloc_upper_bound, (bfd *, sec_ptr));
 249 .  SDEF (unsigned int, _bfd_canonicalize_reloc, (bfd *, sec_ptr, arelent **,
 250 .                                               struct symbol_cache_entry**));
 251 .  SDEF (struct symbol_cache_entry  *, _bfd_make_empty_symbol, (bfd *));
 252 .  SDEF (void,     _bfd_print_symbol, (bfd *, PTR, struct symbol_cache_entry  *,
 253 .                                      bfd_print_symbol_type));
 254 .#define bfd_print_symbol(b,p,s,e) BFD_SEND(b, _bfd_print_symbol, (b,p,s,e))
 255 .  SDEF (alent *,   _get_lineno, (bfd *, struct symbol_cache_entry  *));
 256 .
 257 .  SDEF (boolean,   _bfd_set_arch_mach, (bfd *, enum bfd_architecture,
 258 .                                       unsigned long));
 259 .
 260 .  SDEF (bfd *,  openr_next_archived_file, (bfd *arch, bfd *prev));
 261 .  SDEF (boolean, _bfd_find_nearest_line,
 262 .        (bfd *abfd, struct sec  *section,
 263 .         struct symbol_cache_entry  **symbols,bfd_vma offset,
 264 .        CONST char **file, CONST char **func, unsigned int *line));
 265 .  SDEF (int,    _bfd_stat_arch_elt, (bfd *, struct stat *));
 266 .
 267 .  SDEF (int,    _bfd_sizeof_headers, (bfd *, boolean));
 268 .
 269 .  SDEF (void, _bfd_debug_info_start, (bfd *));
 270 .  SDEF (void, _bfd_debug_info_end, (bfd *));
 271 .  SDEF (void, _bfd_debug_info_accumulate, (bfd *, struct sec  *));
 272 .  SDEF (bfd_byte *, _bfd_get_relocated_section_contents, (bfd*,struct bfd_seclet_struct *, bfd_byte *data));
 273 .  SDEF (boolean,_bfd_relax_section,(bfd *, struct sec *, struct symbol_cache_entry **));
 274 Special entry points for gdb to swap in coff symbol table parts
 275
 276 .  SDEF(void, _bfd_coff_swap_aux_in,(
 277 .       bfd            *abfd ,
 278 .       PTR             ext,
 279 .       int             type,
 280 .       int             class ,
 281 .       PTR             in));
 282 .
 283 .  SDEF(void, _bfd_coff_swap_sym_in,(
 284 .       bfd            *abfd ,
 285 .       PTR             ext,
 286 .       PTR             in));
 287 .
 288 .  SDEF(void, _bfd_coff_swap_lineno_in,  (
 289 .       bfd            *abfd,
 290 .       PTR            ext,
 291 .       PTR             in));
 292 .
 293
 294 Special entry points for gas to swap coff parts
 295
 296 . SDEF(unsigned int, _bfd_coff_swap_aux_out,(
 297 .       bfd     *abfd,
 298 .       PTR     in,
 299 .       int     type,
 300 .       int     class,
 301 .       PTR     ext));
 302 .
 303 . SDEF(unsigned int, _bfd_coff_swap_sym_out,(
 304 .      bfd      *abfd,
 305 .      PTR      in,
 306 .      PTR      ext));
 307 .
 308 . SDEF(unsigned int, _bfd_coff_swap_lineno_out,(
 309 .       bfd     *abfd,
 310 .       PTR     in,
 311 .       PTR     ext));
 312 .
 313 . SDEF(unsigned int, _bfd_coff_swap_reloc_out,(
 314 .       bfd     *abfd,
 315 .       PTR     src,
 316 .       PTR     dst));
 317 .
 318 . SDEF(unsigned int, _bfd_coff_swap_filehdr_out,(
 319 .       bfd     *abfd,
 320 .       PTR     in,
 321 .       PTR     out));
 322 .
 323 . SDEF(unsigned int, _bfd_coff_swap_aouthdr_out,(
 324 .       bfd     *abfd,
 325 .       PTR     in,
 326 .       PTR     out));
 327 .
 328 . SDEF(unsigned int, _bfd_coff_swap_scnhdr_out,(
 329 .       bfd     *abfd,
 330 .       PTR     in,
 331 .       PTR     out));
 332 .
 333 . {* See documentation on reloc types.  *}
 334 . SDEF (CONST struct reloc_howto_struct *,
 335 .       reloc_type_lookup,
 336 .       (bfd *abfd, bfd_reloc_code_real_type code));
 337 .
 338 . {* Complete and utter crock, currently used for the assembler
 339 .    when creating COFF files.  *}
 340 . SDEF (asymbol *, _bfd_make_debug_symbol, (
 341 .       bfd *abfd,
 342 .       void *ptr,
 343 .       unsigned long size));
 344
 345 Data for use by back-end routines; e.g., for a.out, includes whether
 346 this particular target maps ZMAGIC files contiguously or with text and
 347 data separated.  Could perhaps also be used to eliminate some of the
 348 above COFF-specific fields.
 349
 350 . PTR backend_data;
 351 .} bfd_target;
 352
 353 */
 354
 355 /* The default is to define a target_vector containing all the targets.
 356    By setting MINIMIZE=1 on the "make" command line, the user can change this
 357    to a vector containing just DEFAULT_VECTOR and any required
 358    traditional-core-file handler.  (This is to save space in the executables.)
 359    The config files can also override the default large vector by giving an
 360    explicit SELECT_VECS macro.  */
 361
 362 #if MINIMIZE && defined(DEFAULT_VECTOR) && !defined(SELECT_VECS)
 363 #ifdef TRAD_CORE
 364 #define SELECT_VECS &DEFAULT_VECTOR,&trad_core_vec
 365 #else
 366 #define SELECT_VECS &DEFAULT_VECTOR
 367 #endif
 368 #endif
 369
 370 /* All known xvecs.  They are listed a second time below, since
 371    we can't intermix extern's and initializers.  */
 372 extern bfd_target ecoff_little_vec;
 373 extern bfd_target ecoff_big_vec;
 374 extern bfd_target sunos_big_vec;
 375 extern bfd_target demo_64_vec;
 376 extern bfd_target srec_vec;
 377 extern bfd_target tekhex_vec;
 378 extern bfd_target b_out_vec_little_host;
 379 extern bfd_target b_out_vec_big_host;
 380 extern bfd_target icoff_little_vec;
 381 extern bfd_target icoff_big_vec;
 382 extern bfd_target elf_little_vec;
 383 extern bfd_target elf_big_vec;
 384 extern bfd_target ieee_vec;
 385 extern bfd_target oasys_vec;
 386 extern bfd_target m88kbcs_vec;
 387 extern bfd_target m68kcoff_vec;
 388 extern bfd_target i386coff_vec;
 389 extern bfd_target i386aout_vec;
 390 extern bfd_target i386linux_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 extern bfd_target z8kcoff_vec;
 396 extern bfd_target we32kcoff_vec;
 397 #ifdef hp9000s800
 398 extern bfd_target hppa_vec;
 399 #endif
 400
 401 #ifdef DEFAULT_VECTOR
 402 extern bfd_target DEFAULT_VECTOR;
 403 #endif
 404
 405 #ifdef SELECT_VECS
 406
 407 bfd_target *target_vector[] = {
 408         SELECT_VECS,
 409         0
 410 };
 411
 412 #else
 413
 414 bfd_target *target_vector[] = {
 415
 416 #ifdef DEFAULT_VECTOR
 417         &DEFAULT_VECTOR,
 418 #endif
 419
 420         &i386coff_vec,
 421         &i386aout_vec,
 422         &ecoff_little_vec,
 423         &ecoff_big_vec,
 424         &ieee_vec,
 425 #if 1
 426         /* We have no oasys tools anymore, so we can't test any of this
 427            anymore. If you want to test the stuff yourself, go ahead...
 428            steve@cygnus.com */
 429         &oasys_vec,
 430 #endif
 431         &sunos_big_vec,
 432 #ifdef HOST_64_BIT
 433         &demo_64_vec,   /* Only compiled if host has long-long support */
 434 #endif
 435         &h8300coff_vec,
 436         &z8kcoff_vec,
 437         &m88kbcs_vec,
 438         &srec_vec,
 439 /*      &tekhex_vec,*/
 440         &icoff_little_vec,
 441         &icoff_big_vec,
 442         &elf_little_vec,
 443         &elf_big_vec,
 444         &b_out_vec_little_host,
 445         &b_out_vec_big_host,
 446         &m68kcoff_vec,
 447         &a29kcoff_big_vec,
 448         &rs6000coff_vec,
 449 #ifdef hp9000s800
 450         &hppa_vec,
 451 #endif
 452         &we32kcoff_vec,
 453
 454 #ifdef  TRAD_CORE
 455         &trad_core_vec,
 456 #endif
 457         NULL, /* end of list marker */
 458 };
 459
 460 #endif
 461
 462 /* default_vector[0] contains either the address of the default vector,
 463    if there is one, or zero if there isn't.  */
 464
 465 bfd_target *default_vector[] = {
 466 #ifdef DEFAULT_VECTOR
 467         &DEFAULT_VECTOR,
 468 #endif
 469         0,
 470 };
 471
 472
 473
 474
 475 /*
 476 FUNCTION
 477         bfd_find_target
 478
 479 DESCRIPTION
 480         Returns a pointer to the transfer vector for the object target
 481         named target_name.  If target_name is NULL, chooses the one in
 482         the environment variable GNUTARGET; if that is null or not
 483         defined thenthe first entry in the target list is chosen.
 484         Passing in the string "default" or setting the environment
 485         variable to "default" will cause the first entry in the target
 486         list to be returned, and "target_defaulted" will be set in the
 487         BFD.  This causes <<bfd_check_format>> to loop over all the
 488         targets to find the one that matches the file being read.
 489
 490 SYNOPSIS
 491         bfd_target *bfd_find_target(CONST char *, bfd *);
 492 */
 493
 494 bfd_target *
 495 DEFUN(bfd_find_target,(target_name, abfd),
 496       CONST char *target_name AND
 497       bfd *abfd)
 498 {
 499   bfd_target **target;
 500   extern char *getenv ();
 501   CONST char *targname = (target_name ? target_name :
 502                           (CONST char *) getenv ("GNUTARGET"));
 503
 504   /* This is safe; the vector cannot be null */
 505   if (targname == NULL || !strcmp (targname, "default")) {
 506     abfd->target_defaulted = true;
 507     return abfd->xvec = target_vector[0];
 508   }
 509
 510   abfd->target_defaulted = false;
 511
 512   for (target = &target_vector[0]; *target != NULL; target++) {
 513     if (!strcmp (targname, (*target)->name))
 514       return abfd->xvec = *target;
 515   }
 516
 517   bfd_error = invalid_target;
 518   return NULL;
 519 }
 520
 521
 522 /*
 523 FUNCTION
 524         bfd_target_list
 525
 526 DESCRIPTION
 527         This function returns a freshly malloced NULL-terminated
 528         vector of the names of all the valid BFD targets. Do not
 529         modify the names
 530
 531 SYNOPSIS
 532         CONST char **bfd_target_list(void);
 533
 534 */
 535
 536 CONST char **
 537 DEFUN_VOID(bfd_target_list)
 538 {
 539   int vec_length= 0;
 540   bfd_target **target;
 541   CONST  char **name_list, **name_ptr;
 542
 543   for (target = &target_vector[0]; *target != NULL; target++)
 544     vec_length++;
 545
 546   name_ptr =
 547     name_list = (CONST char **) zalloc ((vec_length + 1) * sizeof (char **));
 548
 549   if (name_list == NULL) {
 550     bfd_error = no_memory;
 551     return NULL;
 552   }
 553
 554   for (target = &target_vector[0]; *target != NULL; target++)
 555     *(name_ptr++) = (*target)->name;
 556
 557   return name_list;
 558 }