bfd/targets.c

   1 /* Generic target-file-type support for the BFD library.
   2    Copyright 1990, 1991, 1992, 1993 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         These macros are used to dispatch to functions through the
  94         bfd_target vector. They are used in a number of macros further
  95         down in @file{bfd.h}, and are also used when calling various
  96         routines by hand inside the BFD implementation.  The "arglist"
  97         argument must be parenthesized; it contains all the arguments
  98         to the called function.
  99
 100         They make the documentation (more) unpleasant to read, so if
 101         someone wants to fix this and not break the above, please do.
 102
 103 .#define BFD_SEND(bfd, message, arglist) \
 104 .               ((*((bfd)->xvec->message)) arglist)
 105
 106         For operations which index on the BFD format
 107
 108 .#define BFD_SEND_FMT(bfd, message, arglist) \
 109 .            (((bfd)->xvec->message[(int)((bfd)->format)]) arglist)
 110
 111         This is the struct which defines the type of BFD this is.  The
 112         <<xvec>> member of the struct <<bfd>> itself points here.  Each
 113         module that implements access to a different target under BFD,
 114         defines one of these.
 115
 116
 117         FIXME, these names should be rationalised with the names of
 118         the entry points which call them. Too bad we can't have one
 119         macro to define them both!
 120
 121 .typedef struct bfd_target
 122 .{
 123
 124 Identifies the kind of target, eg SunOS4, Ultrix, etc.
 125
 126 .  char *name;
 127
 128 The "flavour" of a back end is a general indication about the contents
 129 of a file.
 130
 131 .  enum target_flavour {
 132 .    bfd_target_unknown_flavour,
 133 .    bfd_target_aout_flavour,
 134 .    bfd_target_coff_flavour,
 135 .    bfd_target_ecoff_flavour,
 136 .    bfd_target_elf_flavour,
 137 .    bfd_target_ieee_flavour,
 138 .    bfd_target_nlm_flavour,
 139 .    bfd_target_oasys_flavour,
 140 .    bfd_target_tekhex_flavour,
 141 .    bfd_target_srec_flavour,
 142 .    bfd_target_hppa_flavour} flavour;
 143
 144 The order of bytes within the data area of a file.
 145
 146 .  boolean byteorder_big_p;
 147
 148 The order of bytes within the header parts of a file.
 149
 150 .  boolean header_byteorder_big_p;
 151
 152 This is a mask of all the flags which an executable may have set -
 153 from the set <<NO_FLAGS>>, <<HAS_RELOC>>, ...<<D_PAGED>>.
 154
 155 .  flagword object_flags;
 156
 157 This is a mask of all the flags which a section may have set - from
 158 the set <<SEC_NO_FLAGS>>, <<SEC_ALLOC>>, ...<<SET_NEVER_LOAD>>.
 159
 160 .  flagword section_flags;
 161
 162 The character normally found at the front of a symbol
 163 (if any), perhaps _.
 164
 165 .  char symbol_leading_char;
 166
 167 The pad character for filenames within an archive header.
 168
 169 .  char ar_pad_char;
 170
 171 The maximum number of characters in an archive header.
 172
 173 .  unsigned short ar_max_namelen;
 174
 175 The minimum alignment restriction for any section.
 176
 177 .  unsigned int align_power_min;
 178
 179 Entries for byte swapping for data. These are different to the other
 180 entry points, since they don't take BFD as first arg.  Certain other handlers
 181 could do the same.
 182
 183 .  bfd_vma      (*bfd_getx64) PARAMS ((bfd_byte *));
 184 .  bfd_signed_vma (*bfd_getx_signed_64) PARAMS ((bfd_byte *));
 185 .  void         (*bfd_putx64) PARAMS ((bfd_vma, bfd_byte *));
 186 .  bfd_vma      (*bfd_getx32) PARAMS ((bfd_byte *));
 187 .  bfd_signed_vma (*bfd_getx_signed_32) PARAMS ((bfd_byte *));
 188 .  void         (*bfd_putx32) PARAMS ((bfd_vma, bfd_byte *));
 189 .  bfd_vma      (*bfd_getx16) PARAMS ((bfd_byte *));
 190 .  bfd_signed_vma (*bfd_getx_signed_16) PARAMS ((bfd_byte *));
 191 .  void         (*bfd_putx16) PARAMS ((bfd_vma, bfd_byte *));
 192
 193 Byte swapping for the headers
 194
 195 .  bfd_vma      (*bfd_h_getx64) PARAMS ((bfd_byte *));
 196 .  bfd_signed_vma (*bfd_h_getx_signed_64) PARAMS ((bfd_byte *));
 197 .  void         (*bfd_h_putx64) PARAMS ((bfd_vma, bfd_byte *));
 198 .  bfd_vma      (*bfd_h_getx32) PARAMS ((bfd_byte *));
 199 .  bfd_signed_vma (*bfd_h_getx_signed_32) PARAMS ((bfd_byte *));
 200 .  void         (*bfd_h_putx32) PARAMS ((bfd_vma, bfd_byte *));
 201 .  bfd_vma      (*bfd_h_getx16) PARAMS ((bfd_byte *));
 202 .  bfd_signed_vma (*bfd_h_getx_signed_16) PARAMS ((bfd_byte *));
 203 .  void         (*bfd_h_putx16) PARAMS ((bfd_vma, bfd_byte *));
 204
 205 Format dependent routines: these are vectors of entry points
 206 within the target vector structure, one for each format to check.
 207
 208 Check the format of a file being read.  Return bfd_target * or zero.
 209
 210 .  struct bfd_target * (*_bfd_check_format[bfd_type_end]) PARAMS ((bfd *));
 211
 212 Set the format of a file being written.
 213
 214 .  boolean             (*_bfd_set_format[bfd_type_end]) PARAMS ((bfd *));
 215
 216 Write cached information into a file being written, at bfd_close.
 217
 218 .  boolean             (*_bfd_write_contents[bfd_type_end]) PARAMS ((bfd *));
 219
 220 The following functions are defined in <<JUMP_TABLE>>. The idea is
 221 that the back end writer of <<foo>> names all the routines
 222 <<foo_>>@var{entry_point}, <<JUMP_TABLE>> will built the entries
 223 in this structure in the right order.
 224
 225 Core file entry points
 226
 227 .  char *   (*_core_file_failing_command) PARAMS ((bfd *));
 228 .  int      (*_core_file_failing_signal) PARAMS ((bfd *));
 229 .  boolean  (*_core_file_matches_executable_p) PARAMS ((bfd *, bfd *));
 230
 231 Archive entry points
 232
 233 .  boolean  (*_bfd_slurp_armap) PARAMS ((bfd *));
 234 .  boolean  (*_bfd_slurp_extended_name_table) PARAMS ((bfd *));
 235 .  void     (*_bfd_truncate_arname) PARAMS ((bfd *, CONST char *, char *));
 236 .  boolean  (*write_armap) PARAMS ((bfd *arch,
 237 .                              unsigned int elength,
 238 .                              struct orl *map,
 239 .                              unsigned int orl_count,
 240 .                              int stridx));
 241
 242 Standard stuff.
 243
 244 .  boolean       (*_close_and_cleanup) PARAMS ((bfd *));
 245 .  boolean       (*_bfd_set_section_contents) PARAMS ((bfd *, sec_ptr, PTR,
 246 .                                            file_ptr, bfd_size_type));
 247 .  boolean       (*_bfd_get_section_contents) PARAMS ((bfd *, sec_ptr, PTR,
 248 .                                            file_ptr, bfd_size_type));
 249 .  boolean       (*_new_section_hook) PARAMS ((bfd *, sec_ptr));
 250
 251 Symbols and relocations
 252
 253 .  unsigned int  (*_get_symtab_upper_bound) PARAMS ((bfd *));
 254 .  unsigned int  (*_bfd_canonicalize_symtab) PARAMS ((bfd *,
 255 .                                              struct symbol_cache_entry **));
 256 .  unsigned int  (*_get_reloc_upper_bound) PARAMS ((bfd *, sec_ptr));
 257 .  unsigned int  (*_bfd_canonicalize_reloc) PARAMS ((bfd *, sec_ptr, arelent **,
 258 .                                              struct symbol_cache_entry **));
 259 .  struct symbol_cache_entry  *
 260 .                (*_bfd_make_empty_symbol) PARAMS ((bfd *));
 261 .  void          (*_bfd_print_symbol) PARAMS ((bfd *, PTR,
 262 .                                      struct symbol_cache_entry *,
 263 .                                      bfd_print_symbol_type));
 264 .#define bfd_print_symbol(b,p,s,e) BFD_SEND(b, _bfd_print_symbol, (b,p,s,e))
 265 .  void          (*_bfd_get_symbol_info) PARAMS ((bfd *,
 266 .                                      struct symbol_cache_entry *,
 267 .                                      symbol_info *));
 268 .#define bfd_get_symbol_info(b,p,e) BFD_SEND(b, _bfd_get_symbol_info, (b,p,e))
 269
 270 .  alent *    (*_get_lineno) PARAMS ((bfd *, struct symbol_cache_entry *));
 271 .
 272 .  boolean    (*_bfd_set_arch_mach) PARAMS ((bfd *, enum bfd_architecture,
 273 .                    unsigned long));
 274 .
 275 .  bfd *      (*openr_next_archived_file) PARAMS ((bfd *arch, bfd *prev));
 276 .
 277 .  boolean    (*_bfd_find_nearest_line) PARAMS ((bfd *abfd,
 278 .                    struct sec *section, struct symbol_cache_entry **symbols,
 279 .                    bfd_vma offset, CONST char **file, CONST char **func,
 280 .                    unsigned int *line));
 281 .
 282 .  int        (*_bfd_stat_arch_elt) PARAMS ((bfd *, struct stat *));
 283 .
 284 .  int        (*_bfd_sizeof_headers) PARAMS ((bfd *, boolean));
 285 .
 286 .  void       (*_bfd_debug_info_start) PARAMS ((bfd *));
 287 .  void       (*_bfd_debug_info_end) PARAMS ((bfd *));
 288 .  void       (*_bfd_debug_info_accumulate) PARAMS ((bfd *, struct sec *));
 289 .
 290 .  bfd_byte * (*_bfd_get_relocated_section_contents) PARAMS ((bfd *,
 291 .                    struct bfd_seclet *, bfd_byte *data,
 292 .                    boolean relocateable));
 293 .
 294 .  boolean    (*_bfd_relax_section) PARAMS ((bfd *, struct sec *,
 295 .                    struct symbol_cache_entry **));
 296 .
 297 .  boolean    (*_bfd_seclet_link) PARAMS ((bfd *, PTR data,
 298 .                     boolean relocateable));
 299
 300 . {* See documentation on reloc types.  *}
 301 . CONST struct reloc_howto_struct *
 302 .       (*reloc_type_lookup) PARAMS ((bfd *abfd,
 303 .                                     bfd_reloc_code_real_type code));
 304 .
 305 . {* Back-door to allow format-aware applications to create debug symbols
 306 .    while using BFD for everything else.  Currently used by the assembler
 307 .    when creating COFF files.  *}
 308 . asymbol *  (*_bfd_make_debug_symbol) PARAMS ((
 309 .       bfd *abfd,
 310 .       void *ptr,
 311 .       unsigned long size));
 312
 313 Data for use by back-end routines, which isn't generic enough to belong
 314 in this structure.
 315
 316 . PTR backend_data;
 317 .} bfd_target;
 318
 319 */
 320
 321 /* All known xvecs.  They are listed a second time below, since
 322    we can't intermix extern's and initializers.  */
 323 extern bfd_target i386lynx_vec;
 324 extern bfd_target ecoff_little_vec;
 325 extern bfd_target ecoff_big_vec;
 326 extern bfd_target aout_mips_little_vec;
 327 extern bfd_target aout_mips_big_vec;
 328 extern bfd_target sunos_big_vec;
 329 extern bfd_target demo_64_vec;
 330 extern bfd_target srec_vec;
 331 extern bfd_target symbolsrec_vec;
 332 extern bfd_target tekhex_vec;
 333 extern bfd_target a_out_adobe_vec;
 334 extern bfd_target b_out_vec_little_host;
 335 extern bfd_target b_out_vec_big_host;
 336 extern bfd_target icoff_little_vec;
 337 extern bfd_target icoff_big_vec;
 338 extern bfd_target bfd_elf32_sparc_vec;
 339 extern bfd_target bfd_elf32_i386_vec;
 340 extern bfd_target bfd_elf32_m68k_vec;
 341 extern bfd_target bfd_elf32_i860_vec;
 342 extern bfd_target bfd_elf32_m88k_vec;
 343 extern bfd_target bfd_elf32_bigmips_vec;
 344 extern bfd_target bfd_elf32_littlemips_vec;
 345 extern bfd_target bfd_elf32_big_generic_vec;
 346 extern bfd_target bfd_elf32_little_generic_vec;
 347 extern bfd_target bfd_elf64_big_generic_vec;
 348 extern bfd_target bfd_elf64_little_generic_vec;
 349 extern bfd_target nlm32_i386_vec;
 350 extern bfd_target nlm32_big_generic_vec;
 351 extern bfd_target nlm32_little_generic_vec;
 352 extern bfd_target nlm64_big_generic_vec;
 353 extern bfd_target nlm64_little_generic_vec;
 354 extern bfd_target ieee_vec;
 355 extern bfd_target oasys_vec;
 356 extern bfd_target m88kbcs_vec;
 357 extern bfd_target m68kcoff_vec;
 358 extern bfd_target m68kcoffun_vec;
 359 extern bfd_target i386coff_vec;
 360 extern bfd_target i386aout_vec;
 361 extern bfd_target i386linux_vec;
 362 extern bfd_target a29kcoff_big_vec;
 363 extern bfd_target trad_core_vec;
 364 extern bfd_target sco_core_vec;
 365 extern bfd_target aix386_core_vec;
 366 extern bfd_target hpux_core_vec;
 367 extern bfd_target rs6000coff_vec;
 368 extern bfd_target h8300coff_vec;
 369 extern bfd_target h8500coff_vec;
 370 extern bfd_target z8kcoff_vec;
 371 extern bfd_target we32kcoff_vec;
 372 extern bfd_target shcoff_vec;
 373 extern bfd_target hp300hpux_vec;
 374 extern bfd_target hp300bsd_vec;
 375 extern bfd_target hppa_vec;
 376
 377 bfd_target *target_vector[] = {
 378
 379 #ifdef SELECT_VECS
 380
 381         SELECT_VECS,
 382
 383 #else /* not SELECT_VECS */
 384
 385         &i386coff_vec,
 386         &i386aout_vec,
 387         &i386lynx_vec,
 388         &ecoff_little_vec,
 389         &ecoff_big_vec,
 390         &aout_mips_little_vec,
 391         &aout_mips_big_vec,
 392         &ieee_vec,
 393 #if 0
 394         /* We have no oasys tools anymore, so we can't test any of this
 395            anymore. If you want to test the stuff yourself, go ahead...
 396            steve@cygnus.com
 397            Worse, since there is no magic number for archives, there
 398            can be annoying target mis-matches.  */
 399         &oasys_vec,
 400 #endif
 401         &sunos_big_vec,
 402 #ifdef BFD64
 403         &demo_64_vec,   /* Only compiled if host has long-long support */
 404 #endif
 405         &h8300coff_vec,
 406         &z8kcoff_vec,
 407         &m88kbcs_vec,
 408         &srec_vec,
 409         &symbolsrec_vec,
 410 #if 0
 411         &tekhex_vec,
 412 #endif
 413         &icoff_little_vec,
 414         &icoff_big_vec,
 415         &bfd_elf32_sparc_vec,
 416         &bfd_elf32_i386_vec,
 417         &bfd_elf32_m68k_vec,
 418         &bfd_elf32_i860_vec,
 419         &bfd_elf32_m88k_vec,
 420         &bfd_elf32_littlemips_vec,
 421         &bfd_elf32_bigmips_vec,
 422         &bfd_elf32_little_generic_vec,
 423         &bfd_elf32_big_generic_vec,
 424         &nlm32_i386_vec,
 425         &nlm32_little_generic_vec,
 426         &nlm32_big_generic_vec,
 427 #ifdef BFD64
 428         &bfd_elf64_little_generic_vec,
 429         &bfd_elf64_big_generic_vec,
 430         &nlm64_little_generic_vec,
 431         &nlm64_big_generic_vec,
 432 #endif
 433         &a_out_adobe_vec,
 434         &b_out_vec_little_host,
 435         &b_out_vec_big_host,
 436         &m68kcoff_vec,
 437         &m68kcoffun_vec,
 438         &a29kcoff_big_vec,
 439         &rs6000coff_vec,
 440 #if defined (HOST_HPPAHPUX) || defined (HOST_HPPABSD)
 441         &hppa_vec,
 442 #endif
 443         &hp300hpux_vec,
 444         &hp300bsd_vec,
 445         &we32kcoff_vec,
 446
 447 #endif /* not SELECT_VECS */
 448
 449 /* Add any required traditional-core-file-handler.  */
 450
 451 #ifdef  TRAD_CORE
 452         &trad_core_vec,
 453 #endif
 454 #ifdef  SCO_CORE
 455         &sco_core_vec,
 456 #endif
 457 #ifdef AIX386_CORE
 458         &aix386_core_vec,
 459 #endif
 460 #ifdef HPUX_CORE
 461         &hpux_core_vec,
 462 #endif
 463
 464         NULL /* end of list marker */
 465 };
 466
 467 /* default_vector[0] contains either the address of the default vector,
 468    if there is one, or zero if there isn't.  */
 469
 470 bfd_target *default_vector[] = {
 471 #ifdef DEFAULT_VECTOR
 472         &DEFAULT_VECTOR,
 473 #endif
 474         NULL
 475 };
 476
 477
 478
 479
 480 /*
 481 FUNCTION
 482         bfd_find_target
 483
 484 DESCRIPTION
 485         Returns a pointer to the transfer vector for the object target
 486         named target_name.  If target_name is NULL, chooses the one in
 487         the environment variable GNUTARGET; if that is null or not
 488         defined thenthe first entry in the target list is chosen.
 489         Passing in the string "default" or setting the environment
 490         variable to "default" will cause the first entry in the target
 491         list to be returned, and "target_defaulted" will be set in the
 492         BFD.  This causes <<bfd_check_format>> to loop over all the
 493         targets to find the one that matches the file being read.
 494
 495 SYNOPSIS
 496         bfd_target *bfd_find_target(CONST char *, bfd *);
 497 */
 498
 499 bfd_target *
 500 DEFUN(bfd_find_target,(target_name, abfd),
 501       CONST char *target_name AND
 502       bfd *abfd)
 503 {
 504   bfd_target **target;
 505   extern char *getenv ();
 506   CONST char *targname = (target_name ? target_name :
 507                           (CONST char *) getenv ("GNUTARGET"));
 508
 509   /* This is safe; the vector cannot be null */
 510   if (targname == NULL || !strcmp (targname, "default")) {
 511     abfd->target_defaulted = true;
 512     return abfd->xvec = target_vector[0];
 513   }
 514
 515   abfd->target_defaulted = false;
 516
 517   for (target = &target_vector[0]; *target != NULL; target++) {
 518     if (!strcmp (targname, (*target)->name))
 519       return abfd->xvec = *target;
 520   }
 521
 522   bfd_error = invalid_target;
 523   return NULL;
 524 }
 525
 526
 527 /*
 528 FUNCTION
 529         bfd_target_list
 530
 531 DESCRIPTION
 532         This function returns a freshly malloced NULL-terminated
 533         vector of the names of all the valid BFD targets. Do not
 534         modify the names
 535
 536 SYNOPSIS
 537         CONST char **bfd_target_list(void);
 538
 539 */
 540
 541 CONST char **
 542 DEFUN_VOID(bfd_target_list)
 543 {
 544   int vec_length= 0;
 545 #ifdef NATIVE_HPPAHPUX_COMPILER
 546   /* The native compiler on the HP9000/700 has a bug which causes it
 547      to loop endlessly when compiling this file.  This avoids it.  */
 548   volatile
 549 #endif
 550     bfd_target **target;
 551   CONST  char **name_list, **name_ptr;
 552
 553   for (target = &target_vector[0]; *target != NULL; target++)
 554     vec_length++;
 555
 556   name_ptr =
 557     name_list = (CONST char **) zalloc ((vec_length + 1) * sizeof (char **));
 558
 559   if (name_list == NULL) {
 560     bfd_error = no_memory;
 561     return NULL;
 562   }
 563
 564   for (target = &target_vector[0]; *target != NULL; target++)
 565     *(name_ptr++) = (*target)->name;
 566
 567   return name_list;
 568 }