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 <sysdep.h>
  24 #include "bfd.h"
  25 #include "libbfd.h"
  26
  27 /*doc*
  28 @section Targets
  29 Each port of BFD to a different machine requries the creation of a
  30 target back end. All the back end provides to the root part of BFD is
  31 a structure containing pointers to functions which perform certain low
  32 level operations on files. BFD translates the applications's requests
  33 through a pointer into calls to the back end routines.
  34
  35 When a file is opened with @code{bfd_openr}, its format and target are
  36 unknown. BFD uses various mechanisms to determine how to interpret the
  37 file. The operations performed are:
  38 @itemize @bullet
  39 @item
  40 First a BFD is created by calling the internal routine
  41 @code{new_bfd}, then @code{bfd_find_target} is called with the target
  42 string supplied to @code{bfd_openr} and the new BFD pointer.
  43 @item
  44 If a null target string was provided to
  45 @code{bfd_find_target}, it looks up the environment variable
  46 @code{GNUTARGET} and uses that as the target string.
  47 @item
  48 If the target string is still NULL, or the target string
  49 is @code{default}, then the first item in the target vector is used as
  50 the target type. @xref{bfd_target}.
  51 @item
  52 Otherwise, the elements in the target vector are
  53 inspected one by one, until a match on target name is found. When
  54 found, that is used.
  55 @item
  56 Otherwise the error @code{invalid_target} is returned to
  57 @code{bfd_openr}.
  58 @item
  59 @code{bfd_openr} attempts to open the file using
  60 @code{bfd_open_file}, and returns the BFD.
  61 @end itemize
  62 Once the BFD has been opened and the target selected, the file format
  63 may be determined. This is done by calling @code{bfd_check_format} on
  64 the BFD with a suggested format. The routine returns @code{true} when
  65 the application guesses right.
  66 */
  67
  68
  69 /*proto* bfd_target
  70 @node bfd_target
  71 @subsection bfd_target
  72 This structure contains everything that BFD knows about a target.
  73 It includes things like its byte order, name, what routines to call
  74 to do various operations, etc.
  75
  76 Every BFD points to a target structure with its "xvec" member.
  77
  78
  79 Shortcut for declaring fields which are prototyped function pointers,
  80 while avoiding anguish on compilers that don't support protos.
  81
  82 $#define SDEF(ret, name, arglist) \
  83 $                PROTO(ret,(*name),arglist)
  84 $#define SDEF_FMT(ret, name, arglist) \
  85 $                PROTO(ret,(*name[bfd_type_end]),arglist)
  86
  87 These macros are used to dispatch to functions through the bfd_target
  88 vector. They are used in a number of macros further down in @file{bfd.h}, and
  89 are also used when calling various routines by hand inside the BFD
  90 implementation.  The "arglist" argument must be parenthesized; it
  91 contains all the arguments to the called function.
  92
  93 $#define BFD_SEND(bfd, message, arglist) \
  94 $               ((*((bfd)->xvec->message)) arglist)
  95
  96 For operations which index on the BFD format
  97
  98 $#define BFD_SEND_FMT(bfd, message, arglist) \
  99 $            (((bfd)->xvec->message[(int)((bfd)->format)]) arglist)
 100
 101 This is the struct which defines the type of BFD this is.  The
 102 "xvec" member of the struct @code{bfd} itself points here.  Each module
 103 that implements access to a different target under BFD, defines
 104 one of these.
 105
 106 FIXME, these names should be rationalised with the names of the
 107 entry points which call them. Too bad we can't have one macro to
 108 define them both!
 109
 110 *+++
 111
 112 $typedef struct bfd_target
 113 ${
 114
 115 identifies the kind of target, eg SunOS4, Ultrix, etc
 116
 117 $  char *name;
 118
 119 The "flavour" of a back end is a general indication about the contents
 120 of a file.
 121
 122 $  enum target_flavour_enum {
 123 $    bfd_target_aout_flavour_enum,
 124 $    bfd_target_coff_flavour_enum,
 125 $    bfd_target_elf_flavour_enum,
 126 $    bfd_target_ieee_flavour_enum,
 127 $    bfd_target_oasys_flavour_enum,
 128 $    bfd_target_srec_flavour_enum} flavour;
 129
 130 The order of bytes within the data area of a file.
 131
 132 $  boolean byteorder_big_p;
 133
 134 The order of bytes within the header parts of a file.
 135
 136 $  boolean header_byteorder_big_p;
 137
 138 This is a mask of all the flags which an executable may have set -
 139 from the set @code{NO_FLAGS}, @code{HAS_RELOC}, ...@code{D_PAGED}.
 140
 141 $  flagword object_flags;
 142
 143 This is a mask of all the flags which a section may have set - from
 144 the set @code{SEC_NO_FLAGS}, @code{SEC_ALLOC}, ...@code{SET_NEVER_LOAD}.
 145
 146 $  flagword section_flags;
 147
 148 The pad character for filenames within an archive header.
 149
 150 $  char ar_pad_char;
 151
 152 The maximum number of characters in an archive header.
 153
 154 $ unsigned short ar_max_namelen;
 155
 156 The minimum alignment restriction for any section.
 157
 158 $  unsigned int align_power_min;
 159
 160 Entries for byte swapping for data. These are different to the other
 161 entry points, since they don't take BFD as first arg.  Certain other handlers
 162 could do the same.
 163
 164 $  SDEF (bfd_vma,      bfd_getx64, (bfd_byte *));
 165 $  SDEF (void,         bfd_putx64, (bfd_vma, bfd_byte *));
 166 $  SDEF (bfd_vma, bfd_getx32, (bfd_byte *));
 167 $  SDEF (void,         bfd_putx32, (bfd_vma, bfd_byte *));
 168 $  SDEF (bfd_vma, bfd_getx16, (bfd_byte *));
 169 $  SDEF (void,         bfd_putx16, (bfd_vma, bfd_byte *));
 170
 171 Byte swapping for the headers
 172
 173 $  SDEF (bfd_vma,   bfd_h_getx64, (bfd_byte *));
 174 $  SDEF (void,          bfd_h_putx64, (bfd_vma, bfd_byte *));
 175 $  SDEF (bfd_vma,  bfd_h_getx32, (bfd_byte *));
 176 $  SDEF (void,          bfd_h_putx32, (bfd_vma, bfd_byte *));
 177 $  SDEF (bfd_vma,  bfd_h_getx16, (bfd_byte *));
 178 $  SDEF (void,          bfd_h_putx16, (bfd_vma, bfd_byte *));
 179
 180 Format dependent routines, these turn into vectors of entry points
 181 within the target vector structure; one for each format to check.
 182
 183 Check the format of a file being read.  Return bfd_target * or zero.
 184
 185 $  SDEF_FMT (struct bfd_target *, _bfd_check_format, (bfd *));
 186
 187 Set the format of a file being written.
 188
 189 $  SDEF_FMT (boolean,            _bfd_set_format, (bfd *));
 190
 191 Write cached information into a file being written, at bfd_close.
 192
 193 $  SDEF_FMT (boolean,            _bfd_write_contents, (bfd *));
 194
 195 The following functions are defined in @code{JUMP_TABLE}. The idea is
 196 that the back end writer of @code{foo} names all the routines
 197 @code{foo_}@var{entry_point}, @code{JUMP_TABLE} will built the entries
 198 in this structure in the right order.
 199
 200 Core file entry points
 201
 202 $  SDEF (char *, _core_file_failing_command, (bfd *));
 203 $  SDEF (int,    _core_file_failing_signal, (bfd *));
 204 $  SDEF (boolean, _core_file_matches_executable_p, (bfd *, bfd *));
 205
 206 Archive entry points
 207
 208 $ SDEF (boolean, _bfd_slurp_armap, (bfd *));
 209 $ SDEF (boolean, _bfd_slurp_extended_name_table, (bfd *));
 210 $ SDEF (void,   _bfd_truncate_arname, (bfd *, CONST char *, char *));
 211 $ SDEF (boolean, write_armap, (bfd *arch,
 212 $                              unsigned int elength,
 213 $                              struct orl *map,
 214 $                              int orl_count,
 215 $                              int stridx));
 216
 217 Standard stuff.
 218
 219 $  SDEF (boolean, _close_and_cleanup, (bfd *));
 220 $  SDEF (boolean, _bfd_set_section_contents, (bfd *, sec_ptr, PTR,
 221 $                                            file_ptr, bfd_size_type));
 222 $  SDEF (boolean, _bfd_get_section_contents, (bfd *, sec_ptr, PTR,
 223 $                                            file_ptr, bfd_size_type));
 224 $  SDEF (boolean, _new_section_hook, (bfd *, sec_ptr));
 225
 226 Symbols and reloctions
 227
 228 $ SDEF (unsigned int, _get_symtab_upper_bound, (bfd *));
 229 $  SDEF (unsigned int, _bfd_canonicalize_symtab,
 230 $           (bfd *, struct symbol_cache_entry **));
 231 $  SDEF (unsigned int, _get_reloc_upper_bound, (bfd *, sec_ptr));
 232 $  SDEF (unsigned int, _bfd_canonicalize_reloc, (bfd *, sec_ptr, arelent **,
 233 $                                               struct symbol_cache_entry**));
 234 $  SDEF (struct symbol_cache_entry  *, _bfd_make_empty_symbol, (bfd *));
 235 $  SDEF (void,     _bfd_print_symbol, (bfd *, PTR, struct symbol_cache_entry  *,
 236 $                                      bfd_print_symbol_enum_type));
 237 $#define bfd_print_symbol(b,p,s,e) BFD_SEND(b, _bfd_print_symbol, (b,p,s,e))
 238 $  SDEF (alent *,   _get_lineno, (bfd *, struct symbol_cache_entry  *));
 239 $
 240 $  SDEF (boolean,   _bfd_set_arch_mach, (bfd *, enum bfd_architecture,
 241 $                                       unsigned long));
 242 $
 243 $  SDEF (bfd *,  openr_next_archived_file, (bfd *arch, bfd *prev));
 244 $  SDEF (boolean, _bfd_find_nearest_line,
 245 $        (bfd *abfd, struct sec  *section,
 246 $         struct symbol_cache_entry  **symbols,bfd_vma offset,
 247 $        CONST char **file, CONST char **func, unsigned int *line));
 248 $  SDEF (int,    _bfd_stat_arch_elt, (bfd *, struct stat *));
 249 $
 250 $  SDEF (int,    _bfd_sizeof_headers, (bfd *, boolean));
 251 $
 252 $  SDEF (void, _bfd_debug_info_start, (bfd *));
 253 $  SDEF (void, _bfd_debug_info_end, (bfd *));
 254 $  SDEF (void, _bfd_debug_info_accumulate, (bfd *, struct sec  *));
 255
 256 Special entry points for gdb to swap in coff symbol table parts
 257
 258 $  SDEF(void, _bfd_coff_swap_aux_in,(
 259 $       bfd            *abfd ,
 260 $       PTR             ext,
 261 $       int             type,
 262 $       int             class ,
 263 $       PTR             in));
 264 $
 265 $  SDEF(void, _bfd_coff_swap_sym_in,(
 266 $       bfd            *abfd ,
 267 $       PTR             ext,
 268 $       PTR             in));
 269 $
 270 $  SDEF(void, _bfd_coff_swap_lineno_in,  (
 271 $       bfd            *abfd,
 272 $       PTR            ext,
 273 $       PTR             in));
 274 $
 275 $} bfd_target;
 276
 277 *---
 278
 279 */
 280 extern bfd_target ecoff_little_vec;
 281 extern bfd_target ecoff_big_vec;
 282 extern bfd_target sunos_big_vec;
 283 extern bfd_target demo_64_vec;
 284 extern bfd_target srec_vec;
 285 extern bfd_target b_out_vec_little_host;
 286 extern bfd_target b_out_vec_big_host;
 287 extern bfd_target icoff_little_vec;
 288 extern bfd_target icoff_big_vec;
 289 extern bfd_target elf_little_vec;
 290 extern bfd_target elf_big_vec;
 291 extern bfd_target ieee_vec;
 292 extern bfd_target oasys_vec;
 293 extern bfd_target m88k_bcs_vec;
 294 extern bfd_target m68kcoff_vec;
 295 extern bfd_target i386coff_vec;
 296 extern bfd_target a29kcoff_big_vec;
 297
 298 #ifdef SELECT_VECS
 299
 300 bfd_target *target_vector[] = {
 301 SELECT_VECS,
 302 0
 303
 304 };
 305 #else
 306 #ifdef DEFAULT_VECTOR
 307 extern bfd_target DEFAULT_VECTOR;
 308 #endif
 309
 310 #ifdef GNU960
 311 #define ICOFF_LITTLE_VEC        icoff_little_vec
 312 #define ICOFF_BIG_VEC           icoff_big_vec
 313 #define B_OUT_VEC_LITTLE_HOST   b_out_vec_little_host
 314 #define B_OUT_VEC_BIG_HOST      b_out_vec_big_host
 315 #endif /* GNU960 */
 316
 317 #ifndef RESTRICTED
 318 #define ECOFF_LITTLE_VEC        ecoff_little_vec
 319 #define ECOFF_BIG_VEC           ecoff_big_vec
 320 #define ICOFF_LITTLE_VEC        icoff_little_vec
 321 #define ICOFF_BIG_VEC           icoff_big_vec
 322 #define ELF_LITTLE_VEC          elf_little_vec
 323 #define ELF_BIG_VEC             elf_big_vec
 324 #define ZB_OUT_VEC_LITTLE_HOST  b_out_vec_little_host
 325 #define ZB_OUT_VEC_BIG_HOST     b_out_vec_big_host
 326 #define SUNOS_VEC_BIG_HOST      sunos_big_vec
 327 #define DEMO_64_VEC             demo_64_vec
 328 #define OASYS_VEC               oasys_vec
 329 #define IEEE_VEC                ieee_vec
 330 #define M88K_BCS_VEC            m88k_bcs_vec
 331 #define SREC_VEC                srec_vec
 332 #define M68KCOFF_VEC            m68kcoff_vec
 333 #define I386COFF_VEC            i386coff_vec
 334 #define A29KCOFF_BIG_VEC        a29kcoff_big_vec
 335 #endif
 336
 337 bfd_target *target_vector[] = {
 338
 339 #ifdef DEFAULT_VECTOR
 340         &DEFAULT_VECTOR,
 341 #endif /* DEFAULT_VECTOR */
 342
 343 #ifdef  I386COFF_VEC
 344         &I386COFF_VEC,
 345 #endif  /* I386COFF_VEC */
 346
 347 #ifdef ECOFF_LITTLE_VEC
 348         &ECOFF_LITTLE_VEC,
 349 #endif
 350
 351 #ifdef ECOFF_BIG_VEC
 352         &ECOFF_BIG_VEC,
 353 #endif
 354 #ifdef IEEE_VEC
 355         &IEEE_VEC,
 356 #endif /* IEEE_VEC */
 357
 358 #ifdef OASYS_VEC
 359         &OASYS_VEC,
 360 #endif /* OASYS_VEC */
 361
 362 #ifdef SUNOS_VEC_BIG_HOST
 363         &SUNOS_VEC_BIG_HOST,
 364 #endif /* SUNOS_BIG_VEC */
 365
 366
 367 #ifdef HOST_64_BIT
 368 #ifdef DEMO_64_VEC
 369         &DEMO_64_VEC,
 370 #endif
 371 #endif
 372
 373 #ifdef M88K_BCS_VEC
 374         &M88K_BCS_VEC,
 375 #endif /* M88K_BCS_VEC */
 376
 377 #ifdef SREC_VEC
 378         &SREC_VEC,
 379 #endif /* SREC_VEC */
 380
 381 #ifdef ICOFF_LITTLE_VEC
 382         &ICOFF_LITTLE_VEC,
 383 #endif /* ICOFF_LITTLE_VEC */
 384
 385 #ifdef ICOFF_BIG_VEC
 386         &ICOFF_BIG_VEC,
 387 #endif /* ICOFF_BIG_VEC */
 388
 389 #ifdef ELF_LITTLE_VEC
 390         &ELF_LITTLE_VEC,
 391 #endif /* ELF_LITTLE_VEC */
 392
 393 #ifdef ELF_BIG_VEC
 394         &ELF_BIG_VEC,
 395 #endif /* ELF_BIG_VEC */
 396
 397 #ifdef B_OUT_VEC_LITTLE_HOST
 398         &B_OUT_VEC_LITTLE_HOST,
 399 #endif /* B_OUT_VEC_LITTLE_HOST */
 400
 401 #ifdef B_OUT_VEC_BIG_HOST
 402         &B_OUT_VEC_BIG_HOST,
 403 #endif /* B_OUT_VEC_BIG_HOST */
 404
 405 #ifdef  M68KCOFF_VEC
 406         &M68KCOFF_VEC,
 407 #endif  /* M68KCOFF_VEC */
 408
 409 #ifdef  A29KCOFF_BIG_VEC
 410         &A29KCOFF_BIG_VEC,
 411 #endif  /* A29KCOFF_BIG_VEC */
 412
 413         NULL, /* end of list marker */
 414 };
 415
 416 #endif
 417
 418 /* default_vector[0] contains either the address of the default vector,
 419    if there is one, or zero if there isn't.  */
 420
 421 bfd_target *default_vector[] = {
 422 #ifdef DEFAULT_VECTOR
 423         &DEFAULT_VECTOR,
 424 #endif
 425         0,
 426 };
 427
 428
 429
 430
 431 /*proto*
 432 *i bfd_find_target
 433 Returns a pointer to the transfer vector for the object target
 434 named target_name.  If target_name is NULL, chooses the one in the
 435 environment variable GNUTARGET; if that is null or not defined then
 436 the first entry in the target list is chosen.  Passing in the
 437 string "default" or setting the environment variable to "default"
 438 will cause the first entry in the target list to be returned,
 439 and "target_defaulted" will be set in the BFD.  This causes
 440 @code{bfd_check_format} to loop over all the targets to find the one
 441 that matches the file being read.
 442 *; PROTO(bfd_target *, bfd_find_target,(CONST char *, bfd *));
 443 *-*/
 444
 445 bfd_target *
 446 DEFUN(bfd_find_target,(target_name, abfd),
 447       CONST char *target_name AND
 448       bfd *abfd)
 449 {
 450   bfd_target **target;
 451   extern char *getenv ();
 452   CONST char *targname = (target_name ? target_name : getenv ("GNUTARGET"));
 453
 454   /* This is safe; the vector cannot be null */
 455   if (targname == NULL || !strcmp (targname, "default")) {
 456     abfd->target_defaulted = true;
 457     return abfd->xvec = target_vector[0];
 458   }
 459
 460   abfd->target_defaulted = false;
 461
 462   for (target = &target_vector[0]; *target != NULL; target++) {
 463     if (!strcmp (targname, (*target)->name))
 464       return abfd->xvec = *target;
 465   }
 466
 467   bfd_error = invalid_target;
 468   return NULL;
 469 }
 470
 471
 472 /*proto*
 473 *i bfd_target_list
 474 This function returns a freshly malloced NULL-terminated vector of the
 475 names of all the valid BFD targets. Do not modify the names
 476 *; PROTO(CONST char **,bfd_target_list,());
 477
 478 *-*/
 479
 480 CONST char **
 481 DEFUN_VOID(bfd_target_list)
 482 {
 483   int vec_length= 0;
 484   bfd_target **target;
 485   CONST  char **name_list, **name_ptr;
 486
 487   for (target = &target_vector[0]; *target != NULL; target++)
 488     vec_length++;
 489
 490   name_ptr =
 491     name_list = (CONST char **) zalloc ((vec_length + 1) * sizeof (char **));
 492
 493   if (name_list == NULL) {
 494     bfd_error = no_memory;
 495     return NULL;
 496   }
 497
 498   for (target = &target_vector[0]; *target != NULL; target++)
 499     *(name_ptr++) = (*target)->name;
 500
 501   return name_list;
 502 }