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         Each port of BFD to a different machine requries the creation
  32         of a target back end. All the back end provides to the root
  33         part of BFD is a structure containing pointers to functions
  34         which perform certain low level operations on files. BFD
  35         translates the applications's requests through a pointer into
  36         calls to the back end routines.
  37
  38         When a file is opened with <<bfd_openr>>, its format and
  39         target are unknown. BFD uses various mechanisms to determine
  40         how to interpret the file. The operations performed are:
  41
  42         o First a BFD is created by calling the internal routine
  43         <<new_bfd>>, then <<bfd_find_target>> is called with the
  44         target string supplied to <<bfd_openr>> and the new BFD pointer.
  45
  46         o If a null target string was provided to <<bfd_find_target>>,
  47         it looks up the environment variable <<GNUTARGET>> and uses
  48         that as the target string.
  49
  50         o If the target string is still NULL, or the target string is
  51         <<default>>, then the first item in the target vector is used
  52         as the target type. @xref{bfd_target}.
  53
  54         o Otherwise, the elements in the target vector are inspected
  55         one by one, until a match on target name is found. When found,
  56         that is used.
  57
  58         o Otherwise the error <<invalid_target>> is returned to
  59         <<bfd_openr>>.
  60
  61         o <<bfd_openr>> attempts to open the file using
  62         <<bfd_open_file>>, and returns the BFD.
  63
  64         Once the BFD has been opened and the target selected, the file
  65         format may be determined. This is done by calling
  66         <<bfd_check_format>> on the BFD with a suggested format. The
  67         routine returns <<true>> when the application guesses right.
  68 @menu
  69 * bfd_target::
  70 @end menu
  71 */
  72
  73
  74 /*
  75
  76 @node bfd_target,  , Targets, Targets
  77
  78 SUBSECTION
  79         bfd_target
  80
  81         This structure contains everything that BFD knows about a
  82         target. It includes things like its byte order, name, what
  83         routines to call to do various operations, etc.
  84
  85         Every BFD points to a target structure with its <<xvec>>
  86         member.
  87
  88         Shortcut for declaring fields which are prototyped function
  89         pointers, while avoiding anguish on compilers that don't
  90         support protos.
  91
  92 .#define SDEF(ret, name, arglist) \
  93 .                PROTO(ret,(*name),arglist)
  94 .#define SDEF_FMT(ret, name, arglist) \
  95 .                PROTO(ret,(*name[bfd_type_end]),arglist)
  96
  97         These macros are used to dispatch to functions through the
  98         bfd_target vector. They are used in a number of macros further
  99         down in @file{bfd.h}, and are also used when calling various
 100         routines by hand inside the BFD implementation.  The "arglist"
 101         argument must be parenthesized; it contains all the arguments
 102         to the called function.
 103
 104
 105 .#define BFD_SEND(bfd, message, arglist) \
 106 .               ((*((bfd)->xvec->message)) arglist)
 107
 108         For operations which index on the BFD format
 109
 110 .#define BFD_SEND_FMT(bfd, message, arglist) \
 111 .            (((bfd)->xvec->message[(int)((bfd)->format)]) arglist)
 112
 113         This is the struct which defines the type of BFD this is.  The
 114         <<xvec>> member of the struct <<bfd>> itself points here.  Each
 115         module that implements access to a different target under BFD,
 116         defines one of these.
 117
 118
 119         FIXME, these names should be rationalised with the names of
 120         the entry points which call them. Too bad we can't have one
 121         macro to define them both!
 122
 123 .typedef struct bfd_target
 124 .{
 125
 126 identifies the kind of target, eg SunOS4, Ultrix, etc
 127
 128 .  char *name;
 129
 130 The "flavour" of a back end is a general indication about the contents
 131 of a file.
 132
 133 .  enum target_flavour {
 134 .    bfd_target_unknown_flavour,
 135 .    bfd_target_aout_flavour,
 136 .    bfd_target_coff_flavour,
 137 .    bfd_target_elf_flavour,
 138 .    bfd_target_ieee_flavour,
 139 .    bfd_target_oasys_flavour,
 140 .    bfd_target_srec_flavour} flavour;
 141
 142 The order of bytes within the data area of a file.
 143
 144 .  boolean byteorder_big_p;
 145
 146 The order of bytes within the header parts of a file.
 147
 148 .  boolean header_byteorder_big_p;
 149
 150 This is a mask of all the flags which an executable may have set -
 151 from the set <<NO_FLAGS>>, <<HAS_RELOC>>, ...<<D_PAGED>>.
 152
 153 .  flagword object_flags;
 154
 155 This is a mask of all the flags which a section may have set - from
 156 the set <<SEC_NO_FLAGS>>, <<SEC_ALLOC>>, ...<<SET_NEVER_LOAD>>.
 157
 158 .  flagword section_flags;
 159
 160 The pad character for filenames within an archive header.
 161
 162 .  char ar_pad_char;
 163
 164 The maximum number of characters in an archive header.
 165
 166 . unsigned short ar_max_namelen;
 167
 168 The minimum alignment restriction for any section.
 169
 170 .  unsigned int align_power_min;
 171
 172 Entries for byte swapping for data. These are different to the other
 173 entry points, since they don't take BFD as first arg.  Certain other handlers
 174 could do the same.
 175
 176 .  SDEF (bfd_vma,      bfd_getx64, (bfd_byte *));
 177 .  SDEF (void,         bfd_putx64, (bfd_vma, bfd_byte *));
 178 .  SDEF (bfd_vma, bfd_getx32, (bfd_byte *));
 179 .  SDEF (void,         bfd_putx32, (bfd_vma, bfd_byte *));
 180 .  SDEF (bfd_vma, bfd_getx16, (bfd_byte *));
 181 .  SDEF (void,         bfd_putx16, (bfd_vma, bfd_byte *));
 182
 183 Byte swapping for the headers
 184
 185 .  SDEF (bfd_vma,   bfd_h_getx64, (bfd_byte *));
 186 .  SDEF (void,          bfd_h_putx64, (bfd_vma, bfd_byte *));
 187 .  SDEF (bfd_vma,  bfd_h_getx32, (bfd_byte *));
 188 .  SDEF (void,          bfd_h_putx32, (bfd_vma, bfd_byte *));
 189 .  SDEF (bfd_vma,  bfd_h_getx16, (bfd_byte *));
 190 .  SDEF (void,          bfd_h_putx16, (bfd_vma, bfd_byte *));
 191
 192 Format dependent routines, these turn into vectors of entry points
 193 within the target vector structure; one for each format to check.
 194
 195 Check the format of a file being read.  Return bfd_target * or zero.
 196
 197 .  SDEF_FMT (struct bfd_target *, _bfd_check_format, (bfd *));
 198
 199 Set the format of a file being written.
 200
 201 .  SDEF_FMT (boolean,            _bfd_set_format, (bfd *));
 202
 203 Write cached information into a file being written, at bfd_close.
 204
 205 .  SDEF_FMT (boolean,            _bfd_write_contents, (bfd *));
 206
 207 The following functions are defined in <<JUMP_TABLE>>. The idea is
 208 that the back end writer of <<foo>> names all the routines
 209 <<foo_>>@var{entry_point}, <<JUMP_TABLE>> will built the entries
 210 in this structure in the right order.
 211
 212 Core file entry points
 213
 214 .  SDEF (char *, _core_file_failing_command, (bfd *));
 215 .  SDEF (int,    _core_file_failing_signal, (bfd *));
 216 .  SDEF (boolean, _core_file_matches_executable_p, (bfd *, bfd *));
 217
 218 Archive entry points
 219
 220 . SDEF (boolean, _bfd_slurp_armap, (bfd *));
 221 . SDEF (boolean, _bfd_slurp_extended_name_table, (bfd *));
 222 . SDEF (void,   _bfd_truncate_arname, (bfd *, CONST char *, char *));
 223 . SDEF (boolean, write_armap, (bfd *arch,
 224 .                              unsigned int elength,
 225 .                              struct orl *map,
 226 .                              unsigned int orl_count,
 227 .                              int stridx));
 228
 229 Standard stuff.
 230
 231 .  SDEF (boolean, _close_and_cleanup, (bfd *));
 232 .  SDEF (boolean, _bfd_set_section_contents, (bfd *, sec_ptr, PTR,
 233 .                                            file_ptr, bfd_size_type));
 234 .  SDEF (boolean, _bfd_get_section_contents, (bfd *, sec_ptr, PTR,
 235 .                                            file_ptr, bfd_size_type));
 236 .  SDEF (boolean, _new_section_hook, (bfd *, sec_ptr));
 237
 238 Symbols and reloctions
 239
 240 .  SDEF (unsigned int, _get_symtab_upper_bound, (bfd *));
 241 .  SDEF (unsigned int, _bfd_canonicalize_symtab,
 242 .           (bfd *, struct symbol_cache_entry **));
 243 .  SDEF (unsigned int, _get_reloc_upper_bound, (bfd *, sec_ptr));
 244 .  SDEF (unsigned int, _bfd_canonicalize_reloc, (bfd *, sec_ptr, arelent **,
 245 .                                               struct symbol_cache_entry**));
 246 .  SDEF (struct symbol_cache_entry  *, _bfd_make_empty_symbol, (bfd *));
 247 .  SDEF (void,     _bfd_print_symbol, (bfd *, PTR, struct symbol_cache_entry  *,
 248 .                                      bfd_print_symbol_type));
 249 .#define bfd_print_symbol(b,p,s,e) BFD_SEND(b, _bfd_print_symbol, (b,p,s,e))
 250 .  SDEF (alent *,   _get_lineno, (bfd *, struct symbol_cache_entry  *));
 251 .
 252 .  SDEF (boolean,   _bfd_set_arch_mach, (bfd *, enum bfd_architecture,
 253 .                                       unsigned long));
 254 .
 255 .  SDEF (bfd *,  openr_next_archived_file, (bfd *arch, bfd *prev));
 256 .  SDEF (boolean, _bfd_find_nearest_line,
 257 .        (bfd *abfd, struct sec  *section,
 258 .         struct symbol_cache_entry  **symbols,bfd_vma offset,
 259 .        CONST char **file, CONST char **func, unsigned int *line));
 260 .  SDEF (int,    _bfd_stat_arch_elt, (bfd *, struct stat *));
 261 .
 262 .  SDEF (int,    _bfd_sizeof_headers, (bfd *, boolean));
 263 .
 264 .  SDEF (void, _bfd_debug_info_start, (bfd *));
 265 .  SDEF (void, _bfd_debug_info_end, (bfd *));
 266 .  SDEF (void, _bfd_debug_info_accumulate, (bfd *, struct sec  *));
 267
 268 Special entry points for gdb to swap in coff symbol table parts
 269
 270 .  SDEF(void, _bfd_coff_swap_aux_in,(
 271 .       bfd            *abfd ,
 272 .       PTR             ext,
 273 .       int             type,
 274 .       int             class ,
 275 .       PTR             in));
 276 .
 277 .  SDEF(void, _bfd_coff_swap_sym_in,(
 278 .       bfd            *abfd ,
 279 .       PTR             ext,
 280 .       PTR             in));
 281 .
 282 .  SDEF(void, _bfd_coff_swap_lineno_in,  (
 283 .       bfd            *abfd,
 284 .       PTR            ext,
 285 .       PTR             in));
 286 .
 287
 288 Special entry points for gas to swap coff parts
 289
 290 . SDEF(unsigned int, _bfd_coff_swap_aux_out,(
 291 .       bfd     *abfd,
 292 .       PTR     in,
 293 .       int     type,
 294 .       int     class,
 295 .       PTR     ext));
 296 .
 297 . SDEF(unsigned int, _bfd_coff_swap_sym_out,(
 298 .      bfd      *abfd,
 299 .      PTR      in,
 300 .      PTR      ext));
 301 .
 302 . SDEF(unsigned int, _bfd_coff_swap_lineno_out,(
 303 .       bfd     *abfd,
 304 .       PTR     in,
 305 .       PTR     ext));
 306 .
 307 . SDEF(unsigned int, _bfd_coff_swap_reloc_out,(
 308 .       bfd     *abfd,
 309 .       PTR     src,
 310 .       PTR     dst));
 311 .
 312 . SDEF(unsigned int, _bfd_coff_swap_filehdr_out,(
 313 .       bfd     *abfd,
 314 .       PTR     in,
 315 .       PTR     out));
 316 .
 317 . SDEF(unsigned int, _bfd_coff_swap_aouthdr_out,(
 318 .       bfd     *abfd,
 319 .       PTR     in,
 320 .       PTR     out));
 321 .
 322 . SDEF(unsigned int, _bfd_coff_swap_scnhdr_out,(
 323 .       bfd     *abfd,
 324 .       PTR     in,
 325 .       PTR     out));
 326 .
 327 .} bfd_target;
 328
 329 */
 330
 331 /* The default is to define a target_vector containing all the targets.
 332    By setting MINIMIZE=1 on the "make" command line, the user can change this
 333    to a vector containing just DEFAULT_VECTOR and any required
 334    traditional-core-file handler.  (This is to save space in the executables.)
 335    The config files can also override the default large vector by giving an
 336    explicit SELECT_VECS macro.  */
 337
 338 #if MINIMIZE && defined(DEFAULT_VECTOR) && !defined(SELECT_VECS)
 339 #ifdef TRAD_CORE
 340 #define SELECT_VECS &DEFAULT_VECTOR,&trad_core_vec
 341 #else
 342 #define SELECT_VECS &DEFAULT_VECTOR
 343 #endif
 344 #endif
 345
 346 /* All known xvecs.  They are listed a second time below, since
 347    we can't intermix extern's and initializers.  */
 348 extern bfd_target ecoff_little_vec;
 349 extern bfd_target ecoff_big_vec;
 350 extern bfd_target sunos_big_vec;
 351 extern bfd_target demo_64_vec;
 352 extern bfd_target srec_vec;
 353 extern bfd_target b_out_vec_little_host;
 354 extern bfd_target b_out_vec_big_host;
 355 extern bfd_target icoff_little_vec;
 356 extern bfd_target icoff_big_vec;
 357 extern bfd_target elf_little_vec;
 358 extern bfd_target elf_big_vec;
 359 extern bfd_target ieee_vec;
 360 extern bfd_target oasys_vec;
 361 extern bfd_target m88kbcs_vec;
 362 extern bfd_target m68kcoff_vec;
 363 extern bfd_target i386coff_vec;
 364 extern bfd_target i386aout_vec;
 365 extern bfd_target a29kcoff_big_vec;
 366 extern bfd_target trad_core_vec;
 367 extern bfd_target rs6000coff_vec;
 368 extern bfd_target h8300coff_vec;
 369
 370 #ifdef DEFAULT_VECTOR
 371 extern bfd_target DEFAULT_VECTOR;
 372 #endif
 373
 374 #ifdef SELECT_VECS
 375
 376 bfd_target *target_vector[] = {
 377         SELECT_VECS,
 378         0
 379 };
 380
 381 #else
 382
 383 bfd_target *target_vector[] = {
 384
 385 #ifdef DEFAULT_VECTOR
 386         &DEFAULT_VECTOR,
 387 #endif
 388
 389         &i386coff_vec,
 390         &i386aout_vec,
 391         &ecoff_little_vec,
 392         &ecoff_big_vec,
 393         &ieee_vec,
 394 #if 0
 395         /* We have no oasys tools anymore, so we can't test any of this
 396            anymore. If you want to test the stuff yourself, go ahead...
 397            steve@cygnus.com */
 398         &oasys_vec,
 399 #endif
 400         &sunos_big_vec,
 401 #ifdef HOST_64_BIT
 402         &demo_64_vec,   /* Only compiled if host has long-long support */
 403 #endif
 404         &h8300coff_vec,
 405         &m88kbcs_vec,
 406         &srec_vec,
 407         &icoff_little_vec,
 408         &icoff_big_vec,
 409         &elf_little_vec,
 410         &elf_big_vec,
 411         &b_out_vec_little_host,
 412         &b_out_vec_big_host,
 413         &m68kcoff_vec,
 414         &a29kcoff_big_vec,
 415         &rs6000coff_vec,
 416
 417 #ifdef  TRAD_CORE
 418         &trad_core_vec,
 419 #endif
 420         NULL, /* end of list marker */
 421 };
 422
 423 #endif
 424
 425 /* default_vector[0] contains either the address of the default vector,
 426    if there is one, or zero if there isn't.  */
 427
 428 bfd_target *default_vector[] = {
 429 #ifdef DEFAULT_VECTOR
 430         &DEFAULT_VECTOR,
 431 #endif
 432         0,
 433 };
 434
 435
 436
 437
 438 /*
 439 FUNCTION
 440         bfd_find_target
 441
 442 DESCRIPTION
 443         Returns a pointer to the transfer vector for the object target
 444         named target_name.  If target_name is NULL, chooses the one in
 445         the environment variable GNUTARGET; if that is null or not
 446         defined thenthe first entry in the target list is chosen.
 447         Passing in the string "default" or setting the environment
 448         variable to "default" will cause the first entry in the target
 449         list to be returned, and "target_defaulted" will be set in the
 450         BFD.  This causes <<bfd_check_format>> to loop over all the
 451         targets to find the one that matches the file being read.
 452
 453 SYNOPSIS
 454         bfd_target *bfd_find_target(CONST char *, bfd *);
 455 */
 456
 457 bfd_target *
 458 DEFUN(bfd_find_target,(target_name, abfd),
 459       CONST char *target_name AND
 460       bfd *abfd)
 461 {
 462   bfd_target **target;
 463   extern char *getenv ();
 464   CONST char *targname = (target_name ? target_name :
 465                           (CONST char *) getenv ("GNUTARGET"));
 466
 467   /* This is safe; the vector cannot be null */
 468   if (targname == NULL || !strcmp (targname, "default")) {
 469     abfd->target_defaulted = true;
 470     return abfd->xvec = target_vector[0];
 471   }
 472
 473   abfd->target_defaulted = false;
 474
 475   for (target = &target_vector[0]; *target != NULL; target++) {
 476     if (!strcmp (targname, (*target)->name))
 477       return abfd->xvec = *target;
 478   }
 479
 480   bfd_error = invalid_target;
 481   return NULL;
 482 }
 483
 484
 485 /*
 486 FUNCTION
 487         bfd_target_list
 488
 489 DESCRIPTION
 490         This function returns a freshly malloced NULL-terminated
 491         vector of the names of all the valid BFD targets. Do not
 492         modify the names
 493
 494 SYNOPSIS
 495         CONST char **bfd_target_list();
 496
 497 */
 498
 499 CONST char **
 500 DEFUN_VOID(bfd_target_list)
 501 {
 502   int vec_length= 0;
 503   bfd_target **target;
 504   CONST  char **name_list, **name_ptr;
 505
 506   for (target = &target_vector[0]; *target != NULL; target++)
 507     vec_length++;
 508
 509   name_ptr =
 510     name_list = (CONST char **) zalloc ((vec_length + 1) * sizeof (char **));
 511
 512   if (name_list == NULL) {
 513     bfd_error = no_memory;
 514     return NULL;
 515   }
 516
 517   for (target = &target_vector[0]; *target != NULL; target++)
 518     *(name_ptr++) = (*target)->name;
 519
 520   return name_list;
 521 }