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 .  void         (*bfd_putx64) PARAMS ((bfd_vma, bfd_byte *));
 184 .  bfd_vma      (*bfd_getx32) PARAMS ((bfd_byte *));
 185 .  void         (*bfd_putx32) PARAMS ((bfd_vma, bfd_byte *));
 186 .  bfd_vma      (*bfd_getx16) PARAMS ((bfd_byte *));
 187 .  void         (*bfd_putx16) PARAMS ((bfd_vma, bfd_byte *));
 188
 189 Byte swapping for the headers
 190
 191 .  bfd_vma      (*bfd_h_getx64) PARAMS ((bfd_byte *));
 192 .  void         (*bfd_h_putx64) PARAMS ((bfd_vma, bfd_byte *));
 193 .  bfd_vma      (*bfd_h_getx32) PARAMS ((bfd_byte *));
 194 .  void         (*bfd_h_putx32) PARAMS ((bfd_vma, bfd_byte *));
 195 .  bfd_vma      (*bfd_h_getx16) PARAMS ((bfd_byte *));
 196 .  void         (*bfd_h_putx16) PARAMS ((bfd_vma, bfd_byte *));
 197
 198 Format dependent routines: these are vectors of entry points
 199 within the target vector structure, one for each format to check.
 200
 201 Check the format of a file being read.  Return bfd_target * or zero.
 202
 203 .  struct bfd_target * (*_bfd_check_format[bfd_type_end]) PARAMS ((bfd *));
 204
 205 Set the format of a file being written.
 206
 207 .  boolean             (*_bfd_set_format[bfd_type_end]) PARAMS ((bfd *));
 208
 209 Write cached information into a file being written, at bfd_close.
 210
 211 .  boolean             (*_bfd_write_contents[bfd_type_end]) PARAMS ((bfd *));
 212
 213 The following functions are defined in <<JUMP_TABLE>>. The idea is
 214 that the back end writer of <<foo>> names all the routines
 215 <<foo_>>@var{entry_point}, <<JUMP_TABLE>> will built the entries
 216 in this structure in the right order.
 217
 218 Core file entry points
 219
 220 .  char *   (*_core_file_failing_command) PARAMS ((bfd *));
 221 .  int      (*_core_file_failing_signal) PARAMS ((bfd *));
 222 .  boolean  (*_core_file_matches_executable_p) PARAMS ((bfd *, bfd *));
 223
 224 Archive entry points
 225
 226 .  boolean  (*_bfd_slurp_armap) PARAMS ((bfd *));
 227 .  boolean  (*_bfd_slurp_extended_name_table) PARAMS ((bfd *));
 228 .  void     (*_bfd_truncate_arname) PARAMS ((bfd *, CONST char *, char *));
 229 .  boolean  (*write_armap) PARAMS ((bfd *arch,
 230 .                              unsigned int elength,
 231 .                              struct orl *map,
 232 .                              unsigned int orl_count,
 233 .                              int stridx));
 234
 235 Standard stuff.
 236
 237 .  boolean       (*_close_and_cleanup) PARAMS ((bfd *));
 238 .  boolean       (*_bfd_set_section_contents) PARAMS ((bfd *, sec_ptr, PTR,
 239 .                                            file_ptr, bfd_size_type));
 240 .  boolean       (*_bfd_get_section_contents) PARAMS ((bfd *, sec_ptr, PTR,
 241 .                                            file_ptr, bfd_size_type));
 242 .  boolean       (*_new_section_hook) PARAMS ((bfd *, sec_ptr));
 243
 244 Symbols and relocations
 245
 246 .  unsigned int  (*_get_symtab_upper_bound) PARAMS ((bfd *));
 247 .  unsigned int  (*_bfd_canonicalize_symtab) PARAMS ((bfd *,
 248 .                                              struct symbol_cache_entry **));
 249 .  unsigned int  (*_get_reloc_upper_bound) PARAMS ((bfd *, sec_ptr));
 250 .  unsigned int  (*_bfd_canonicalize_reloc) PARAMS ((bfd *, sec_ptr, arelent **,
 251 .                                              struct symbol_cache_entry **));
 252 .  struct symbol_cache_entry  *
 253 .                (*_bfd_make_empty_symbol) PARAMS ((bfd *));
 254 .  void          (*_bfd_print_symbol) PARAMS ((bfd *, PTR,
 255 .                                      struct symbol_cache_entry *,
 256 .                                      bfd_print_symbol_type));
 257 .#define bfd_print_symbol(b,p,s,e) BFD_SEND(b, _bfd_print_symbol, (b,p,s,e))
 258
 259 .  alent *    (*_get_lineno) PARAMS ((bfd *, struct symbol_cache_entry *));
 260 .
 261 .  boolean    (*_bfd_set_arch_mach) PARAMS ((bfd *, enum bfd_architecture,
 262 .                    unsigned long));
 263 .
 264 .  bfd *      (*openr_next_archived_file) PARAMS ((bfd *arch, bfd *prev));
 265 .
 266 .  boolean    (*_bfd_find_nearest_line) PARAMS ((bfd *abfd,
 267 .                    struct sec *section, struct symbol_cache_entry **symbols,
 268 .                    bfd_vma offset, CONST char **file, CONST char **func,
 269 .                    unsigned int *line));
 270 .
 271 .  int        (*_bfd_stat_arch_elt) PARAMS ((bfd *, struct stat *));
 272 .
 273 .  int        (*_bfd_sizeof_headers) PARAMS ((bfd *, boolean));
 274 .
 275 .  void       (*_bfd_debug_info_start) PARAMS ((bfd *));
 276 .  void       (*_bfd_debug_info_end) PARAMS ((bfd *));
 277 .  void       (*_bfd_debug_info_accumulate) PARAMS ((bfd *, struct sec *));
 278 .
 279 .  bfd_byte * (*_bfd_get_relocated_section_contents) PARAMS ((bfd *,
 280 .                    struct bfd_seclet *, bfd_byte *data,
 281 .                    boolean relocateable));
 282 .
 283 .  boolean    (*_bfd_relax_section) PARAMS ((bfd *, struct sec *,
 284 .                    struct symbol_cache_entry **));
 285 .
 286 .  boolean    (*_bfd_seclet_link) PARAMS ((bfd *, PTR data,
 287 .                     boolean relocateable));
 288
 289 . {* See documentation on reloc types.  *}
 290 . CONST struct reloc_howto_struct *
 291 .       (*reloc_type_lookup) PARAMS ((bfd *abfd,
 292 .                                     bfd_reloc_code_real_type code));
 293 .
 294 . {* Back-door to allow format-aware applications to create debug symbols
 295 .    while using BFD for everything else.  Currently used by the assembler
 296 .    when creating COFF files.  *}
 297 . asymbol *  (*_bfd_make_debug_symbol) PARAMS ((
 298 .       bfd *abfd,
 299 .       void *ptr,
 300 .       unsigned long size));
 301
 302 Data for use by back-end routines; e.g., for a.out, includes whether
 303 this particular target maps ZMAGIC files contiguously or with text and
 304 data separated.  Could perhaps also be used to eliminate some of the
 305 above COFF-specific fields.
 306
 307 . PTR backend_data;
 308 .} bfd_target;
 309
 310 */
 311
 312 /* The default is to define a target_vector containing all the targets.
 313    By setting MINIMIZE=1 on the "make" command line, the user can change this
 314    to a vector containing just DEFAULT_VECTOR and any required
 315    traditional-core-file handler.  (This is to save space in the executables.)
 316    The config files can also override the default large vector by giving an
 317    explicit SELECT_VECS macro.  */
 318
 319 #if MINIMIZE && defined(DEFAULT_VECTOR) && !defined(SELECT_VECS)
 320 #ifdef TRAD_CORE
 321 #define SELECT_VECS &DEFAULT_VECTOR,&trad_core_vec
 322 #else
 323 #ifdef SCO_CORE
 324 #define SELECT_VECS &DEFAULT_VECTOR,&sco_core_vec
 325 #else
 326 #ifdef AIX386_CORE
 327 #define SELECT_VECS &DEFAULT_VECTOR,&aix386_core_vec
 328 #else
 329 #define SELECT_VECS &DEFAULT_VECTOR
 330 #endif
 331 #endif
 332 #endif
 333 #endif
 334
 335 /* All known xvecs.  They are listed a second time below, since
 336    we can't intermix extern's and initializers.  */
 337 extern bfd_target ecoff_little_vec;
 338 extern bfd_target ecoff_big_vec;
 339 extern bfd_target aout_mips_little_vec;
 340 extern bfd_target aout_mips_big_vec;
 341 extern bfd_target sunos_big_vec;
 342 extern bfd_target demo_64_vec;
 343 extern bfd_target srec_vec;
 344 extern bfd_target symbolsrec_vec;
 345 extern bfd_target tekhex_vec;
 346 extern bfd_target a_out_adobe_vec;
 347 extern bfd_target b_out_vec_little_host;
 348 extern bfd_target b_out_vec_big_host;
 349 extern bfd_target icoff_little_vec;
 350 extern bfd_target icoff_big_vec;
 351 extern bfd_target elf_little_vec;
 352 extern bfd_target elf_big_vec;
 353 extern bfd_target ieee_vec;
 354 extern bfd_target oasys_vec;
 355 extern bfd_target m88kbcs_vec;
 356 extern bfd_target m68kcoff_vec;
 357 extern bfd_target i386coff_vec;
 358 extern bfd_target i386aout_vec;
 359 extern bfd_target i386linux_vec;
 360 extern bfd_target a29kcoff_big_vec;
 361 extern bfd_target trad_core_vec;
 362 extern bfd_target sco_core_vec;
 363 extern bfd_target aix386_core_vec;
 364 extern bfd_target rs6000coff_vec;
 365 extern bfd_target h8300coff_vec;
 366 extern bfd_target h8500coff_vec;
 367 extern bfd_target z8kcoff_vec;
 368 extern bfd_target we32kcoff_vec;
 369 #ifdef HOST_HPPAHPUX
 370 extern bfd_target hppa_vec;
 371 #endif
 372
 373 #ifdef DEFAULT_VECTOR
 374 extern bfd_target DEFAULT_VECTOR;
 375 #endif
 376
 377
 378 bfd_target *target_vector[] = {
 379
 380 #ifdef SELECT_VECS
 381         SELECT_VECS,
 382 #else /* SELECT_VECS */
 383
 384 #ifdef DEFAULT_VECTOR
 385         &DEFAULT_VECTOR,
 386 #endif
 387
 388         &i386coff_vec,
 389         &i386aout_vec,
 390         &ecoff_little_vec,
 391         &ecoff_big_vec,
 392         &aout_mips_little_vec,
 393         &aout_mips_big_vec,
 394         &ieee_vec,
 395 #if 0
 396         /* We have no oasys tools anymore, so we can't test any of this
 397            anymore. If you want to test the stuff yourself, go ahead...
 398            steve@cygnus.com
 399            Worse, since there is no magic number for archives, there
 400            can annoying target mis-matches.  */
 401         &oasys_vec,
 402 #endif
 403         &sunos_big_vec,
 404 #ifdef HOST_64_BIT
 405         &demo_64_vec,   /* Only compiled if host has long-long support */
 406 #endif
 407         &h8300coff_vec,
 408         &z8kcoff_vec,
 409         &m88kbcs_vec,
 410         &srec_vec,
 411         &symbolsrec_vec,
 412 /*      &tekhex_vec,*/
 413         &icoff_little_vec,
 414         &icoff_big_vec,
 415         &elf_little_vec,
 416         &elf_big_vec,
 417         &a_out_adobe_vec,
 418         &b_out_vec_little_host,
 419         &b_out_vec_big_host,
 420         &m68kcoff_vec,
 421         &a29kcoff_big_vec,
 422         &rs6000coff_vec,
 423 #ifdef HOST_HPPAHPUX
 424         &hppa_vec,
 425 #endif
 426         &we32kcoff_vec,
 427
 428 #ifdef  TRAD_CORE
 429         &trad_core_vec,
 430 #endif
 431 #ifdef  SCO_CORE
 432         &sco_core_vec,
 433 #endif
 434 #ifdef AIX386_CORE
 435   &aix386_core_vec,
 436 #endif
 437
 438 #endif /* SELECT_VECS */
 439         NULL, /* end of list marker */
 440 };
 441
 442 /* default_vector[0] contains either the address of the default vector,
 443    if there is one, or zero if there isn't.  */
 444
 445 bfd_target *default_vector[] = {
 446 #ifdef DEFAULT_VECTOR
 447         &DEFAULT_VECTOR,
 448 #endif
 449         0,
 450 };
 451
 452
 453
 454
 455 /*
 456 FUNCTION
 457         bfd_find_target
 458
 459 DESCRIPTION
 460         Returns a pointer to the transfer vector for the object target
 461         named target_name.  If target_name is NULL, chooses the one in
 462         the environment variable GNUTARGET; if that is null or not
 463         defined thenthe first entry in the target list is chosen.
 464         Passing in the string "default" or setting the environment
 465         variable to "default" will cause the first entry in the target
 466         list to be returned, and "target_defaulted" will be set in the
 467         BFD.  This causes <<bfd_check_format>> to loop over all the
 468         targets to find the one that matches the file being read.
 469
 470 SYNOPSIS
 471         bfd_target *bfd_find_target(CONST char *, bfd *);
 472 */
 473
 474 bfd_target *
 475 DEFUN(bfd_find_target,(target_name, abfd),
 476       CONST char *target_name AND
 477       bfd *abfd)
 478 {
 479   bfd_target **target;
 480   extern char *getenv ();
 481   CONST char *targname = (target_name ? target_name :
 482                           (CONST char *) getenv ("GNUTARGET"));
 483
 484   /* This is safe; the vector cannot be null */
 485   if (targname == NULL || !strcmp (targname, "default")) {
 486     abfd->target_defaulted = true;
 487     return abfd->xvec = target_vector[0];
 488   }
 489
 490   abfd->target_defaulted = false;
 491
 492   for (target = &target_vector[0]; *target != NULL; target++) {
 493     if (!strcmp (targname, (*target)->name))
 494       return abfd->xvec = *target;
 495   }
 496
 497   bfd_error = invalid_target;
 498   return NULL;
 499 }
 500
 501
 502 /*
 503 FUNCTION
 504         bfd_target_list
 505
 506 DESCRIPTION
 507         This function returns a freshly malloced NULL-terminated
 508         vector of the names of all the valid BFD targets. Do not
 509         modify the names
 510
 511 SYNOPSIS
 512         CONST char **bfd_target_list(void);
 513
 514 */
 515
 516 CONST char **
 517 DEFUN_VOID(bfd_target_list)
 518 {
 519   int vec_length= 0;
 520 #ifdef NATIVE_HPPAHPUX_COMPILER
 521   /* The native compiler on the HP9000/700 has a bug which causes it
 522      to loop endlessly when compiling this file.  This avoids it.  */
 523   volatile
 524 #endif
 525     bfd_target **target;
 526   CONST  char **name_list, **name_ptr;
 527
 528   for (target = &target_vector[0]; *target != NULL; target++)
 529     vec_length++;
 530
 531   name_ptr =
 532     name_list = (CONST char **) zalloc ((vec_length + 1) * sizeof (char **));
 533
 534   if (name_list == NULL) {
 535     bfd_error = no_memory;
 536     return NULL;
 537   }
 538
 539   for (target = &target_vector[0]; *target != NULL; target++)
 540     *(name_ptr++) = (*target)->name;
 541
 542   return name_list;
 543 }