bfd/targets.c

   1 /* Generic target-file-type support for the BFD library.
   2    Copyright 1990, 1991, 1992 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, and <<target_defaulted>> is set to
  52         cause <<bfd_check_format>> to loop through all the targets.
  53         @xref{bfd_target}.  @xref{Formats}.
  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.
  68         If <<target_defaulted>> has been set, each possible target
  69         type is tried to see if it recognizes the specified format.  The
  70         routine returns <<true>> when the application guesses right.
  71 @menu
  72 @* bfd_target::
  73 @end menu
  74 */
  75
  76
  77 /*
  78
  79 INODE
  80         bfd_target,  , Targets, Targets
  81 DOCDD
  82 SUBSECTION
  83         bfd_target
  84
  85 DESCRIPTION
  86         This structure contains everything that BFD knows about a
  87         target. It includes things like its byte order, name, what
  88         routines to call to do various operations, etc.
  89
  90         Every BFD points to a target structure with its <<xvec>>
  91         member.
  92
  93         Shortcut for declaring fields which are prototyped function
  94         pointers, while avoiding anguish on compilers that don't
  95         support protos.
  96
  97 .#define SDEF(ret, name, arglist) \
  98 .                PROTO(ret,(*name),arglist)
  99 .#define SDEF_FMT(ret, name, arglist) \
 100 .                PROTO(ret,(*name[bfd_type_end]),arglist)
 101
 102         These macros are used to dispatch to functions through the
 103         bfd_target vector. They are used in a number of macros further
 104         down in @file{bfd.h}, and are also used when calling various
 105         routines by hand inside the BFD implementation.  The "arglist"
 106         argument must be parenthesized; it contains all the arguments
 107         to the called function.
 108
 109         They make the documentation (more) unpleasant to read, so if
 110         someone wants to fix this and not break the above, please do.
 111
 112 .#define BFD_SEND(bfd, message, arglist) \
 113 .               ((*((bfd)->xvec->message)) arglist)
 114
 115         For operations which index on the BFD format
 116
 117 .#define BFD_SEND_FMT(bfd, message, arglist) \
 118 .            (((bfd)->xvec->message[(int)((bfd)->format)]) arglist)
 119
 120         This is the struct which defines the type of BFD this is.  The
 121         <<xvec>> member of the struct <<bfd>> itself points here.  Each
 122         module that implements access to a different target under BFD,
 123         defines one of these.
 124
 125
 126         FIXME, these names should be rationalised with the names of
 127         the entry points which call them. Too bad we can't have one
 128         macro to define them both!
 129
 130 .typedef struct bfd_target
 131 .{
 132
 133 Identifies the kind of target, eg SunOS4, Ultrix, etc.
 134
 135 .  char *name;
 136
 137 The "flavour" of a back end is a general indication about the contents
 138 of a file.
 139
 140 .  enum target_flavour {
 141 .    bfd_target_unknown_flavour,
 142 .    bfd_target_aout_flavour,
 143 .    bfd_target_coff_flavour,
 144 .    bfd_target_elf_flavour,
 145 .    bfd_target_ieee_flavour,
 146 .    bfd_target_oasys_flavour,
 147 .    bfd_target_tekhex_flavour,
 148 .    bfd_target_srec_flavour,
 149 .    bfd_target_hppa_flavour} flavour;
 150
 151 The order of bytes within the data area of a file.
 152
 153 .  boolean byteorder_big_p;
 154
 155 The order of bytes within the header parts of a file.
 156
 157 .  boolean header_byteorder_big_p;
 158
 159 This is a mask of all the flags which an executable may have set -
 160 from the set <<NO_FLAGS>>, <<HAS_RELOC>>, ...<<D_PAGED>>.
 161
 162 .  flagword object_flags;
 163
 164 This is a mask of all the flags which a section may have set - from
 165 the set <<SEC_NO_FLAGS>>, <<SEC_ALLOC>>, ...<<SET_NEVER_LOAD>>.
 166
 167 .  flagword section_flags;
 168
 169 The pad character for filenames within an archive header.
 170
 171 .  char ar_pad_char;
 172
 173 The maximum number of characters in an archive header.
 174
 175 . unsigned short ar_max_namelen;
 176
 177 The minimum alignment restriction for any section.
 178
 179 .  unsigned int align_power_min;
 180
 181 Entries for byte swapping for data. These are different to the other
 182 entry points, since they don't take BFD as first arg.  Certain other handlers
 183 could do the same.
 184
 185 .  SDEF (bfd_vma,      bfd_getx64, (bfd_byte *));
 186 .  SDEF (void,         bfd_putx64, (bfd_vma, bfd_byte *));
 187 .  SDEF (bfd_vma, bfd_getx32, (bfd_byte *));
 188 .  SDEF (void,         bfd_putx32, (bfd_vma, bfd_byte *));
 189 .  SDEF (bfd_vma, bfd_getx16, (bfd_byte *));
 190 .  SDEF (void,         bfd_putx16, (bfd_vma, bfd_byte *));
 191
 192 Byte swapping for the headers
 193
 194 .  SDEF (bfd_vma,   bfd_h_getx64, (bfd_byte *));
 195 .  SDEF (void,          bfd_h_putx64, (bfd_vma, bfd_byte *));
 196 .  SDEF (bfd_vma,  bfd_h_getx32, (bfd_byte *));
 197 .  SDEF (void,          bfd_h_putx32, (bfd_vma, bfd_byte *));
 198 .  SDEF (bfd_vma,  bfd_h_getx16, (bfd_byte *));
 199 .  SDEF (void,          bfd_h_putx16, (bfd_vma, bfd_byte *));
 200
 201 Format dependent routines, these turn into vectors of entry points
 202 within the target vector structure; one for each format to check.
 203
 204 Check the format of a file being read.  Return bfd_target * or zero.
 205
 206 .  SDEF_FMT (struct bfd_target *, _bfd_check_format, (bfd *));
 207
 208 Set the format of a file being written.
 209
 210 .  SDEF_FMT (boolean,            _bfd_set_format, (bfd *));
 211
 212 Write cached information into a file being written, at bfd_close.
 213
 214 .  SDEF_FMT (boolean,            _bfd_write_contents, (bfd *));
 215
 216 The following functions are defined in <<JUMP_TABLE>>. The idea is
 217 that the back end writer of <<foo>> names all the routines
 218 <<foo_>>@var{entry_point}, <<JUMP_TABLE>> will built the entries
 219 in this structure in the right order.
 220
 221 Core file entry points
 222
 223 .  SDEF (char *, _core_file_failing_command, (bfd *));
 224 .  SDEF (int,    _core_file_failing_signal, (bfd *));
 225 .  SDEF (boolean, _core_file_matches_executable_p, (bfd *, bfd *));
 226
 227 Archive entry points
 228
 229 . SDEF (boolean, _bfd_slurp_armap, (bfd *));
 230 . SDEF (boolean, _bfd_slurp_extended_name_table, (bfd *));
 231 . SDEF (void,   _bfd_truncate_arname, (bfd *, CONST char *, char *));
 232 . SDEF (boolean, write_armap, (bfd *arch,
 233 .                              unsigned int elength,
 234 .                              struct orl *map,
 235 .                              unsigned int orl_count,
 236 .                              int stridx));
 237
 238 Standard stuff.
 239
 240 .  SDEF (boolean, _close_and_cleanup, (bfd *));
 241 .  SDEF (boolean, _bfd_set_section_contents, (bfd *, sec_ptr, PTR,
 242 .                                            file_ptr, bfd_size_type));
 243 .  SDEF (boolean, _bfd_get_section_contents, (bfd *, sec_ptr, PTR,
 244 .                                            file_ptr, bfd_size_type));
 245 .  SDEF (boolean, _new_section_hook, (bfd *, sec_ptr));
 246
 247 Symbols and relocations
 248
 249 .  SDEF (unsigned int, _get_symtab_upper_bound, (bfd *));
 250 .  SDEF (unsigned int, _bfd_canonicalize_symtab,
 251 .           (bfd *, struct symbol_cache_entry **));
 252 .  SDEF (unsigned int, _get_reloc_upper_bound, (bfd *, sec_ptr));
 253 .  SDEF (unsigned int, _bfd_canonicalize_reloc, (bfd *, sec_ptr, arelent **,
 254 .                                               struct symbol_cache_entry**));
 255 .  SDEF (struct symbol_cache_entry  *, _bfd_make_empty_symbol, (bfd *));
 256 .  SDEF (void,     _bfd_print_symbol, (bfd *, PTR, struct symbol_cache_entry  *,
 257 .                                      bfd_print_symbol_type));
 258 .#define bfd_print_symbol(b,p,s,e) BFD_SEND(b, _bfd_print_symbol, (b,p,s,e))
 259 .  SDEF (alent *,   _get_lineno, (bfd *, struct symbol_cache_entry  *));
 260 .
 261 .  SDEF (boolean,   _bfd_set_arch_mach, (bfd *, enum bfd_architecture,
 262 .                                       unsigned long));
 263 .
 264 .  SDEF (bfd *,  openr_next_archived_file, (bfd *arch, bfd *prev));
 265 .  SDEF (boolean, _bfd_find_nearest_line,
 266 .        (bfd *abfd, struct sec  *section,
 267 .         struct symbol_cache_entry  **symbols,bfd_vma offset,
 268 .        CONST char **file, CONST char **func, unsigned int *line));
 269 .  SDEF (int,    _bfd_stat_arch_elt, (bfd *, struct stat *));
 270 .
 271 .  SDEF (int,    _bfd_sizeof_headers, (bfd *, boolean));
 272 .
 273 .  SDEF (void, _bfd_debug_info_start, (bfd *));
 274 .  SDEF (void, _bfd_debug_info_end, (bfd *));
 275 .  SDEF (void, _bfd_debug_info_accumulate, (bfd *, struct sec  *));
 276 .  SDEF (bfd_byte *, _bfd_get_relocated_section_contents, (bfd*,struct bfd_seclet_struct *, bfd_byte *data));
 277 .  SDEF (boolean,_bfd_relax_section,(bfd *, struct sec *, struct symbol_cache_entry **));
 278 Special entry points for gdb to swap in coff symbol table parts
 279
 280 .  SDEF(void, _bfd_coff_swap_aux_in,(
 281 .       bfd            *abfd ,
 282 .       PTR             ext,
 283 .       int             type,
 284 .       int             class ,
 285 .       PTR             in));
 286 .
 287 .  SDEF(void, _bfd_coff_swap_sym_in,(
 288 .       bfd            *abfd ,
 289 .       PTR             ext,
 290 .       PTR             in));
 291 .
 292 .  SDEF(void, _bfd_coff_swap_lineno_in,  (
 293 .       bfd            *abfd,
 294 .       PTR            ext,
 295 .       PTR             in));
 296 .
 297
 298 Special entry points for gas to swap coff parts
 299
 300 . SDEF(unsigned int, _bfd_coff_swap_aux_out,(
 301 .       bfd     *abfd,
 302 .       PTR     in,
 303 .       int     type,
 304 .       int     class,
 305 .       PTR     ext));
 306 .
 307 . SDEF(unsigned int, _bfd_coff_swap_sym_out,(
 308 .      bfd      *abfd,
 309 .      PTR      in,
 310 .      PTR      ext));
 311 .
 312 . SDEF(unsigned int, _bfd_coff_swap_lineno_out,(
 313 .       bfd     *abfd,
 314 .       PTR     in,
 315 .       PTR     ext));
 316 .
 317 . SDEF(unsigned int, _bfd_coff_swap_reloc_out,(
 318 .       bfd     *abfd,
 319 .       PTR     src,
 320 .       PTR     dst));
 321 .
 322 . SDEF(unsigned int, _bfd_coff_swap_filehdr_out,(
 323 .       bfd     *abfd,
 324 .       PTR     in,
 325 .       PTR     out));
 326 .
 327 . SDEF(unsigned int, _bfd_coff_swap_aouthdr_out,(
 328 .       bfd     *abfd,
 329 .       PTR     in,
 330 .       PTR     out));
 331 .
 332 . SDEF(unsigned int, _bfd_coff_swap_scnhdr_out,(
 333 .       bfd     *abfd,
 334 .       PTR     in,
 335 .       PTR     out));
 336 .
 337 . {* See documentation on reloc types.  *}
 338 . SDEF (CONST struct reloc_howto_struct *,
 339 .       reloc_type_lookup,
 340 .       (bfd *abfd, bfd_reloc_code_real_type code));
 341 .
 342 . {* Complete and utter crock, currently used for the assembler
 343 .    when creating COFF files.  *}
 344 . SDEF (asymbol *, _bfd_make_debug_symbol, (
 345 .       bfd *abfd,
 346 .       void *ptr,
 347 .       unsigned long size));
 348
 349 Data for use by back-end routines; e.g., for a.out, includes whether
 350 this particular target maps ZMAGIC files contiguously or with text and
 351 data separated.  Could perhaps also be used to eliminate some of the
 352 above COFF-specific fields.
 353
 354 . PTR backend_data;
 355 .} bfd_target;
 356
 357 */
 358
 359 /* The default is to define a target_vector containing all the targets.
 360    By setting MINIMIZE=1 on the "make" command line, the user can change this
 361    to a vector containing just DEFAULT_VECTOR and any required
 362    traditional-core-file handler.  (This is to save space in the executables.)
 363    The config files can also override the default large vector by giving an
 364    explicit SELECT_VECS macro.  */
 365
 366 #if MINIMIZE && defined(DEFAULT_VECTOR) && !defined(SELECT_VECS)
 367 #ifdef TRAD_CORE
 368 #define SELECT_VECS &DEFAULT_VECTOR,&trad_core_vec
 369 #else
 370 #define SELECT_VECS &DEFAULT_VECTOR
 371 #endif
 372 #endif
 373
 374 /* All known xvecs.  They are listed a second time below, since
 375    we can't intermix extern's and initializers.  */
 376 extern bfd_target ecoff_little_vec;
 377 extern bfd_target ecoff_big_vec;
 378 extern bfd_target sunos_big_vec;
 379 extern bfd_target demo_64_vec;
 380 extern bfd_target srec_vec;
 381 extern bfd_target tekhex_vec;
 382 extern bfd_target a_out_adobe_vec;
 383 extern bfd_target b_out_vec_little_host;
 384 extern bfd_target b_out_vec_big_host;
 385 extern bfd_target icoff_little_vec;
 386 extern bfd_target icoff_big_vec;
 387 extern bfd_target elf_little_vec;
 388 extern bfd_target elf_big_vec;
 389 extern bfd_target ieee_vec;
 390 extern bfd_target oasys_vec;
 391 extern bfd_target m88kbcs_vec;
 392 extern bfd_target m68kcoff_vec;
 393 extern bfd_target i386coff_vec;
 394 extern bfd_target i386aout_vec;
 395 extern bfd_target i386linux_vec;
 396 extern bfd_target a29kcoff_big_vec;
 397 extern bfd_target trad_core_vec;
 398 extern bfd_target rs6000coff_vec;
 399 extern bfd_target h8300coff_vec;
 400 extern bfd_target z8kcoff_vec;
 401 extern bfd_target we32kcoff_vec;
 402 #ifdef hp9000s800
 403 extern bfd_target hppa_vec;
 404 #endif
 405
 406 #ifdef DEFAULT_VECTOR
 407 extern bfd_target DEFAULT_VECTOR;
 408 #endif
 409
 410 #ifdef SELECT_VECS
 411
 412 bfd_target *target_vector[] = {
 413         SELECT_VECS,
 414         0
 415 };
 416
 417 #else
 418
 419 bfd_target *target_vector[] = {
 420
 421 #ifdef DEFAULT_VECTOR
 422         &DEFAULT_VECTOR,
 423 #endif
 424
 425         &i386coff_vec,
 426         &i386aout_vec,
 427         &ecoff_little_vec,
 428         &ecoff_big_vec,
 429         &ieee_vec,
 430 #if 0
 431         /* We have no oasys tools anymore, so we can't test any of this
 432            anymore. If you want to test the stuff yourself, go ahead...
 433            steve@cygnus.com
 434            Worse, since there is no magic number for archives, there
 435            can annoying target mis-matches.  */
 436         &oasys_vec,
 437 #endif
 438         &sunos_big_vec,
 439 #ifdef HOST_64_BIT
 440         &demo_64_vec,   /* Only compiled if host has long-long support */
 441 #endif
 442         &h8300coff_vec,
 443         &z8kcoff_vec,
 444         &m88kbcs_vec,
 445         &srec_vec,
 446 /*      &tekhex_vec,*/
 447         &icoff_little_vec,
 448         &icoff_big_vec,
 449         &elf_little_vec,
 450         &elf_big_vec,
 451         &a_out_adobe_vec,
 452         &b_out_vec_little_host,
 453         &b_out_vec_big_host,
 454         &m68kcoff_vec,
 455         &a29kcoff_big_vec,
 456         &rs6000coff_vec,
 457 #ifdef hp9000s800
 458         &hppa_vec,
 459 #endif
 460         &we32kcoff_vec,
 461
 462 #ifdef  TRAD_CORE
 463         &trad_core_vec,
 464 #endif
 465         NULL, /* end of list marker */
 466 };
 467
 468 #endif
 469
 470 /* default_vector[0] contains either the address of the default vector,
 471    if there is one, or zero if there isn't.  */
 472
 473 bfd_target *default_vector[] = {
 474 #ifdef DEFAULT_VECTOR
 475         &DEFAULT_VECTOR,
 476 #endif
 477         0,
 478 };
 479
 480
 481
 482
 483 /*
 484 FUNCTION
 485         bfd_find_target
 486
 487 DESCRIPTION
 488         Returns a pointer to the transfer vector for the object target
 489         named target_name.  If target_name is NULL, chooses the one in
 490         the environment variable GNUTARGET; if that is null or not
 491         defined thenthe first entry in the target list is chosen.
 492         Passing in the string "default" or setting the environment
 493         variable to "default" will cause the first entry in the target
 494         list to be returned, and "target_defaulted" will be set in the
 495         BFD.  This causes <<bfd_check_format>> to loop over all the
 496         targets to find the one that matches the file being read.
 497
 498 SYNOPSIS
 499         bfd_target *bfd_find_target(CONST char *, bfd *);
 500 */
 501
 502 bfd_target *
 503 DEFUN(bfd_find_target,(target_name, abfd),
 504       CONST char *target_name AND
 505       bfd *abfd)
 506 {
 507   bfd_target **target;
 508   extern char *getenv ();
 509   CONST char *targname = (target_name ? target_name :
 510                           (CONST char *) getenv ("GNUTARGET"));
 511
 512   /* This is safe; the vector cannot be null */
 513   if (targname == NULL || !strcmp (targname, "default")) {
 514     abfd->target_defaulted = true;
 515     return abfd->xvec = target_vector[0];
 516   }
 517
 518   abfd->target_defaulted = false;
 519
 520   for (target = &target_vector[0]; *target != NULL; target++) {
 521     if (!strcmp (targname, (*target)->name))
 522       return abfd->xvec = *target;
 523   }
 524
 525   bfd_error = invalid_target;
 526   return NULL;
 527 }
 528
 529
 530 /*
 531 FUNCTION
 532         bfd_target_list
 533
 534 DESCRIPTION
 535         This function returns a freshly malloced NULL-terminated
 536         vector of the names of all the valid BFD targets. Do not
 537         modify the names
 538
 539 SYNOPSIS
 540         CONST char **bfd_target_list(void);
 541
 542 */
 543
 544 CONST char **
 545 DEFUN_VOID(bfd_target_list)
 546 {
 547   int vec_length= 0;
 548   bfd_target **target;
 549   CONST  char **name_list, **name_ptr;
 550
 551   for (target = &target_vector[0]; *target != NULL; target++)
 552     vec_length++;
 553
 554   name_ptr =
 555     name_list = (CONST char **) zalloc ((vec_length + 1) * sizeof (char **));
 556
 557   if (name_list == NULL) {
 558     bfd_error = no_memory;
 559     return NULL;
 560   }
 561
 562   for (target = &target_vector[0]; *target != NULL; target++)
 563     *(name_ptr++) = (*target)->name;
 564
 565   return name_list;
 566 }