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_oasys_flavour,
 139 .    bfd_target_tekhex_flavour,
 140 .    bfd_target_srec_flavour,
 141 .    bfd_target_hppa_flavour} flavour;
 142
 143 The order of bytes within the data area of a file.
 144
 145 .  boolean byteorder_big_p;
 146
 147 The order of bytes within the header parts of a file.
 148
 149 .  boolean header_byteorder_big_p;
 150
 151 This is a mask of all the flags which an executable may have set -
 152 from the set <<NO_FLAGS>>, <<HAS_RELOC>>, ...<<D_PAGED>>.
 153
 154 .  flagword object_flags;
 155
 156 This is a mask of all the flags which a section may have set - from
 157 the set <<SEC_NO_FLAGS>>, <<SEC_ALLOC>>, ...<<SET_NEVER_LOAD>>.
 158
 159 .  flagword section_flags;
 160
 161 The character normally found at the front of a symbol
 162 (if any), perhaps _.
 163
 164 .  char symbol_leading_char;
 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 .  bfd_vma      (*bfd_getx64) PARAMS ((bfd_byte *));
 183 .  bfd_signed_vma (*bfd_getx_signed_64) PARAMS ((bfd_byte *));
 184 .  void         (*bfd_putx64) PARAMS ((bfd_vma, bfd_byte *));
 185 .  bfd_vma      (*bfd_getx32) PARAMS ((bfd_byte *));
 186 .  bfd_signed_vma (*bfd_getx_signed_32) PARAMS ((bfd_byte *));
 187 .  void         (*bfd_putx32) PARAMS ((bfd_vma, bfd_byte *));
 188 .  bfd_vma      (*bfd_getx16) PARAMS ((bfd_byte *));
 189 .  bfd_signed_vma (*bfd_getx_signed_16) PARAMS ((bfd_byte *));
 190 .  void         (*bfd_putx16) PARAMS ((bfd_vma, bfd_byte *));
 191
 192 Byte swapping for the headers
 193
 194 .  bfd_vma      (*bfd_h_getx64) PARAMS ((bfd_byte *));
 195 .  bfd_signed_vma (*bfd_h_getx_signed_64) PARAMS ((bfd_byte *));
 196 .  void         (*bfd_h_putx64) PARAMS ((bfd_vma, bfd_byte *));
 197 .  bfd_vma      (*bfd_h_getx32) PARAMS ((bfd_byte *));
 198 .  bfd_signed_vma (*bfd_h_getx_signed_32) PARAMS ((bfd_byte *));
 199 .  void         (*bfd_h_putx32) PARAMS ((bfd_vma, bfd_byte *));
 200 .  bfd_vma      (*bfd_h_getx16) PARAMS ((bfd_byte *));
 201 .  bfd_signed_vma (*bfd_h_getx_signed_16) PARAMS ((bfd_byte *));
 202 .  void         (*bfd_h_putx16) PARAMS ((bfd_vma, bfd_byte *));
 203
 204 Format dependent routines: these are vectors of entry points
 205 within the target vector structure, one for each format to check.
 206
 207 Check the format of a file being read.  Return bfd_target * or zero.
 208
 209 .  struct bfd_target * (*_bfd_check_format[bfd_type_end]) PARAMS ((bfd *));
 210
 211 Set the format of a file being written.
 212
 213 .  boolean             (*_bfd_set_format[bfd_type_end]) PARAMS ((bfd *));
 214
 215 Write cached information into a file being written, at bfd_close.
 216
 217 .  boolean             (*_bfd_write_contents[bfd_type_end]) PARAMS ((bfd *));
 218
 219 The following functions are defined in <<JUMP_TABLE>>. The idea is
 220 that the back end writer of <<foo>> names all the routines
 221 <<foo_>>@var{entry_point}, <<JUMP_TABLE>> will built the entries
 222 in this structure in the right order.
 223
 224 Core file entry points
 225
 226 .  char *   (*_core_file_failing_command) PARAMS ((bfd *));
 227 .  int      (*_core_file_failing_signal) PARAMS ((bfd *));
 228 .  boolean  (*_core_file_matches_executable_p) PARAMS ((bfd *, bfd *));
 229
 230 Archive entry points
 231
 232 .  boolean  (*_bfd_slurp_armap) PARAMS ((bfd *));
 233 .  boolean  (*_bfd_slurp_extended_name_table) PARAMS ((bfd *));
 234 .  void     (*_bfd_truncate_arname) PARAMS ((bfd *, CONST char *, char *));
 235 .  boolean  (*write_armap) PARAMS ((bfd *arch,
 236 .                              unsigned int elength,
 237 .                              struct orl *map,
 238 .                              unsigned int orl_count,
 239 .                              int stridx));
 240
 241 Standard stuff.
 242
 243 .  boolean       (*_close_and_cleanup) PARAMS ((bfd *));
 244 .  boolean       (*_bfd_set_section_contents) PARAMS ((bfd *, sec_ptr, PTR,
 245 .                                            file_ptr, bfd_size_type));
 246 .  boolean       (*_bfd_get_section_contents) PARAMS ((bfd *, sec_ptr, PTR,
 247 .                                            file_ptr, bfd_size_type));
 248 .  boolean       (*_new_section_hook) PARAMS ((bfd *, sec_ptr));
 249
 250 Symbols and relocations
 251
 252 .  unsigned int  (*_get_symtab_upper_bound) PARAMS ((bfd *));
 253 .  unsigned int  (*_bfd_canonicalize_symtab) PARAMS ((bfd *,
 254 .                                              struct symbol_cache_entry **));
 255 .  unsigned int  (*_get_reloc_upper_bound) PARAMS ((bfd *, sec_ptr));
 256 .  unsigned int  (*_bfd_canonicalize_reloc) PARAMS ((bfd *, sec_ptr, arelent **,
 257 .                                              struct symbol_cache_entry **));
 258 .  struct symbol_cache_entry  *
 259 .                (*_bfd_make_empty_symbol) PARAMS ((bfd *));
 260 .  void          (*_bfd_print_symbol) PARAMS ((bfd *, PTR,
 261 .                                      struct symbol_cache_entry *,
 262 .                                      bfd_print_symbol_type));
 263 .#define bfd_print_symbol(b,p,s,e) BFD_SEND(b, _bfd_print_symbol, (b,p,s,e))
 264
 265 .  alent *    (*_get_lineno) PARAMS ((bfd *, struct symbol_cache_entry *));
 266 .
 267 .  boolean    (*_bfd_set_arch_mach) PARAMS ((bfd *, enum bfd_architecture,
 268 .                    unsigned long));
 269 .
 270 .  bfd *      (*openr_next_archived_file) PARAMS ((bfd *arch, bfd *prev));
 271 .
 272 .  boolean    (*_bfd_find_nearest_line) PARAMS ((bfd *abfd,
 273 .                    struct sec *section, struct symbol_cache_entry **symbols,
 274 .                    bfd_vma offset, CONST char **file, CONST char **func,
 275 .                    unsigned int *line));
 276 .
 277 .  int        (*_bfd_stat_arch_elt) PARAMS ((bfd *, struct stat *));
 278 .
 279 .  int        (*_bfd_sizeof_headers) PARAMS ((bfd *, boolean));
 280 .
 281 .  void       (*_bfd_debug_info_start) PARAMS ((bfd *));
 282 .  void       (*_bfd_debug_info_end) PARAMS ((bfd *));
 283 .  void       (*_bfd_debug_info_accumulate) PARAMS ((bfd *, struct sec *));
 284 .
 285 .  bfd_byte * (*_bfd_get_relocated_section_contents) PARAMS ((bfd *,
 286 .                    struct bfd_seclet *, bfd_byte *data,
 287 .                    boolean relocateable));
 288 .
 289 .  boolean    (*_bfd_relax_section) PARAMS ((bfd *, struct sec *,
 290 .                    struct symbol_cache_entry **));
 291 .
 292 .  boolean    (*_bfd_seclet_link) PARAMS ((bfd *, PTR data,
 293 .                     boolean relocateable));
 294
 295 . {* See documentation on reloc types.  *}
 296 . CONST struct reloc_howto_struct *
 297 .       (*reloc_type_lookup) PARAMS ((bfd *abfd,
 298 .                                     bfd_reloc_code_real_type code));
 299 .
 300 . {* Back-door to allow format-aware applications to create debug symbols
 301 .    while using BFD for everything else.  Currently used by the assembler
 302 .    when creating COFF files.  *}
 303 . asymbol *  (*_bfd_make_debug_symbol) PARAMS ((
 304 .       bfd *abfd,
 305 .       void *ptr,
 306 .       unsigned long size));
 307
 308 Data for use by back-end routines, which isn't generic enough to belong
 309 in this structure.
 310
 311 . PTR backend_data;
 312 .} bfd_target;
 313
 314 */
 315
 316 /* The default is to define a target_vector containing all the targets.
 317    By setting MINIMIZE=1 on the "make" command line, the user can change this
 318    to a vector containing just DEFAULT_VECTOR and any required
 319    traditional-core-file handler.  (This is to save space in the executables.)
 320    The config files can also override the default large vector by giving an
 321    explicit SELECT_VECS macro.  */
 322
 323 #if MINIMIZE && defined(DEFAULT_VECTOR) && !defined(SELECT_VECS)
 324 #ifdef TRAD_CORE
 325 #define SELECT_VECS &DEFAULT_VECTOR,&trad_core_vec
 326 #else
 327 #ifdef SCO_CORE
 328 #define SELECT_VECS &DEFAULT_VECTOR,&sco_core_vec
 329 #else
 330 #ifdef AIX386_CORE
 331 #define SELECT_VECS &DEFAULT_VECTOR,&aix386_core_vec
 332 #else
 333 #define SELECT_VECS &DEFAULT_VECTOR
 334 #endif
 335 #endif
 336 #endif
 337 #endif
 338
 339 /* All known xvecs.  They are listed a second time below, since
 340    we can't intermix extern's and initializers.  */
 341 extern bfd_target ecoff_little_vec;
 342 extern bfd_target ecoff_big_vec;
 343 extern bfd_target aout_mips_little_vec;
 344 extern bfd_target aout_mips_big_vec;
 345 extern bfd_target sunos_big_vec;
 346 extern bfd_target demo_64_vec;
 347 extern bfd_target srec_vec;
 348 extern bfd_target symbolsrec_vec;
 349 extern bfd_target tekhex_vec;
 350 extern bfd_target a_out_adobe_vec;
 351 extern bfd_target b_out_vec_little_host;
 352 extern bfd_target b_out_vec_big_host;
 353 extern bfd_target icoff_little_vec;
 354 extern bfd_target icoff_big_vec;
 355 extern bfd_target elf32_sparc_vec;
 356 extern bfd_target elf32_i386_vec;
 357 extern bfd_target elf32_m68k_vec;
 358 extern bfd_target elf32_i860_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 i386linux_vec;
 366 extern bfd_target a29kcoff_big_vec;
 367 extern bfd_target trad_core_vec;
 368 extern bfd_target sco_core_vec;
 369 extern bfd_target aix386_core_vec;
 370 extern bfd_target rs6000coff_vec;
 371 extern bfd_target h8300coff_vec;
 372 extern bfd_target h8500coff_vec;
 373 extern bfd_target z8kcoff_vec;
 374 extern bfd_target we32kcoff_vec;
 375 #ifdef HOST_HPPAHPUX
 376 extern bfd_target hppa_vec;
 377 #endif
 378
 379 #ifdef DEFAULT_VECTOR
 380 extern bfd_target DEFAULT_VECTOR;
 381 #endif
 382
 383
 384 bfd_target *target_vector[] = {
 385
 386 #ifdef SELECT_VECS
 387
 388         SELECT_VECS,
 389
 390 #else /* not SELECT_VECS */
 391
 392 #ifdef DEFAULT_VECTOR
 393         &DEFAULT_VECTOR,
 394 #endif
 395
 396         &i386coff_vec,
 397         &i386aout_vec,
 398         &ecoff_little_vec,
 399         &ecoff_big_vec,
 400         &aout_mips_little_vec,
 401         &aout_mips_big_vec,
 402         &ieee_vec,
 403 #if 0
 404         /* We have no oasys tools anymore, so we can't test any of this
 405            anymore. If you want to test the stuff yourself, go ahead...
 406            steve@cygnus.com
 407            Worse, since there is no magic number for archives, there
 408            can annoying target mis-matches.  */
 409         &oasys_vec,
 410 #endif
 411         &sunos_big_vec,
 412 #ifdef HOST_64_BIT
 413         &demo_64_vec,   /* Only compiled if host has long-long support */
 414 #endif
 415         &h8300coff_vec,
 416         &z8kcoff_vec,
 417         &m88kbcs_vec,
 418         &srec_vec,
 419         &symbolsrec_vec,
 420 /*      &tekhex_vec,*/
 421         &icoff_little_vec,
 422         &icoff_big_vec,
 423         &elf32_sparc_vec,
 424         &elf32_i386_vec,
 425         &elf32_m68k_vec,
 426         &elf32_i860_vec,
 427         &a_out_adobe_vec,
 428         &b_out_vec_little_host,
 429         &b_out_vec_big_host,
 430         &m68kcoff_vec,
 431         &a29kcoff_big_vec,
 432         &rs6000coff_vec,
 433 #ifdef HOST_HPPAHPUX
 434         &hppa_vec,
 435 #endif
 436         &we32kcoff_vec,
 437
 438 #ifdef  TRAD_CORE
 439         &trad_core_vec,
 440 #endif
 441 #ifdef  SCO_CORE
 442         &sco_core_vec,
 443 #endif
 444 #ifdef AIX386_CORE
 445   &aix386_core_vec,
 446 #endif
 447
 448 #endif /* not SELECT_VECS */
 449         NULL, /* end of list marker */
 450 };
 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 #ifdef NATIVE_HPPAHPUX_COMPILER
 531   /* The native compiler on the HP9000/700 has a bug which causes it
 532      to loop endlessly when compiling this file.  This avoids it.  */
 533   volatile
 534 #endif
 535     bfd_target **target;
 536   CONST  char **name_list, **name_ptr;
 537
 538   for (target = &target_vector[0]; *target != NULL; target++)
 539     vec_length++;
 540
 541   name_ptr =
 542     name_list = (CONST char **) zalloc ((vec_length + 1) * sizeof (char **));
 543
 544   if (name_list == NULL) {
 545     bfd_error = no_memory;
 546     return NULL;
 547   }
 548
 549   for (target = &target_vector[0]; *target != NULL; target++)
 550     *(name_ptr++) = (*target)->name;
 551
 552   return name_list;
 553 }