bfd/targets.c

   1 /* Copyright (C) 1990, 1991 Free Software Foundation, Inc.
   2
   3 This file is part of BFD, the Binary File Diddler.
   4
   5 BFD is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation; either version 1, or (at your option)
   8 any later version.
   9
  10 BFD is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with BFD; see the file COPYING.  If not, write to
  17 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  18
  19 /* $Id$ */
  20
  21
  22 #include <sysdep.h>
  23 #include "bfd.h"
  24 #include "libbfd.h"
  25
  26 /*doc*
  27 @section Targets
  28 Each port of BFD to a different machine requries the creation of a
  29 target back end. All the back end provides to the root part of bfd is
  30 a structure containing pointers to functions which perform certain low
  31 level operations on files. BFD translates the applications's requests
  32 through a pointer into calls to the back end routines.
  33
  34 When a file is opened with @code{bfd_openr}, its format and target are
  35 unknown. BFD uses various mechanisms to determine how to interpret the
  36 file. The operatios performed are:
  37 @itemize @bullet
  38 @item
  39 First a bfd is created by calling the internal routine
  40 @code{new_bfd}, then @code{bfd_find_target} is called with the target
  41 string supplied to @code{bfd_openr} and the new bfd pointer.
  42 @item
  43 If a null target string was provided to
  44 @code{bfd_find_target}, it looks up the environment variable
  45 @code{GNUTARGET} and uses that as the target string.
  46 @item
  47 If the target string is still NULL, or the target string
  48 is @code{default}, then the first item in the target vector is used as
  49 the target type. @xref{targets}.
  50 @item
  51 Otherwise, the elements in the target vector are
  52 inspected one by one, until a match on target name is found. When
  53 found, that is used.
  54 @item
  55 Otherwise the error @code{invalid_target} is returned to
  56 @code{bfd_openr}.
  57 @item
  58 @code{bfd_openr} attempts to open the file using
  59 @code{bfd_open_file}, and returns the bfd.
  60 @end itemize
  61 Once the bfd has been opened and the target selected, the file format
  62 may be determined. This is done by calling @code{bfd_check_format} on
  63 the bfd with a suggested format. The routine returns @code{true} when
  64 the application guesses right.
  65 */
  66
  67
  68 /*proto* bfd_target
  69 @node bfd_target
  70 @subsection bfd_target
  71 This structure contains everything that BFD knows about a target.
  72 It includes things like its byte order, name, what routines to call
  73 to do various operations, etc.
  74
  75 Every BFD points to a target structure with its "xvec" member.
  76
  77
  78 Shortcut for declaring fields which are prototyped function pointers,
  79 while avoiding anguish on compilers that don't support protos.
  80
  81 $#define SDEF(ret, name, arglist) \
  82 $                PROTO(ret,(*name),arglist)
  83 $#define SDEF_FMT(ret, name, arglist) \
  84 $                PROTO(ret,(*name[bfd_type_end]),arglist)
  85
  86 These macros are used to dispatch to functions through the bfd_target
  87 vector. They are used in a number of macros further down in bfd.h, and
  88 are also used when calling various routines by hand inside the bfd
  89 implementation.  The "arglist" argument must be parenthesized; it
  90 contains all the arguments to the called function.
  91
  92 $#define BFD_SEND(bfd, message, arglist) \
  93 $               ((*((bfd)->xvec->message)) arglist)
  94
  95 For operations which index on the bfd format
  96
  97 $#define BFD_SEND_FMT(bfd, message, arglist) \
  98 $            (((bfd)->xvec->message[(int)((bfd)->format)]) arglist)
  99
 100 This is the struct which defines the type of BFD this is.  The
 101 "xvec" member of the struct bfd itself points here.  Each module
 102 that implements access to a different target under BFD, defines
 103 one of these.
 104
 105 FIXME, these names should be rationalised with the names of the
 106 entry points which call them. Too bad we can't have one macro to
 107 define them both!
 108
 109 *+++
 110
 111 $typedef struct bfd_target
 112 ${
 113
 114 identifies the kind of target, eg SunOS4, Ultrix, etc
 115
 116 $  char *name;
 117
 118 The "flavour" of a back end is a general indication about the contents
 119 of a file.
 120
 121 $  enum target_flavour_enum {
 122 $    bfd_target_aout_flavour_enum,
 123 $    bfd_target_coff_flavour_enum,
 124 $    bfd_target_ieee_flavour_enum,
 125 $    bfd_target_oasys_flavour_enum,
 126 $    bfd_target_srec_flavour_enum} flavour;
 127
 128 The order of bytes within the data area of a file.
 129
 130 $  boolean byteorder_big_p;
 131
 132 The order of bytes within the header parts of a file.
 133
 134 $  boolean header_byteorder_big_p;
 135
 136 This is a mask of all the flags which an executable may have set -
 137 from the set @code{NO_FLAGS}, @code{HAS_RELOC}, ...@code{D_PAGED}.
 138
 139 $  flagword object_flags;
 140
 141 This is a mask of all the flags which a section may have set - from
 142 the set @code{SEC_NO_FLAGS}, @code{SEC_ALLOC}, ...@code{SET_NEVER_LOAD}.
 143
 144 $  flagword section_flags;
 145
 146 The pad character for filenames within an archive header.
 147
 148 $  char ar_pad_char;
 149
 150 The maximum number of characters in an archive header.
 151
 152 $ unsigned short ar_max_namelen;
 153
 154 The minimum alignment restriction for any section.
 155
 156 $  unsigned int align_power_min;
 157
 158 Entries for byte swapping for data. These are different to the other
 159 entry points, since they don't take bfd as first arg.  Certain other handlers
 160 could do the same.
 161
 162 $  SDEF (bfd_vma,      bfd_getx64, (bfd_byte *));
 163 $  SDEF (void,         bfd_putx64, (bfd_vma, bfd_byte *));
 164 $  SDEF (bfd_vma, bfd_getx32, (bfd_byte *));
 165 $  SDEF (void,         bfd_putx32, (bfd_vma, bfd_byte *));
 166 $  SDEF (bfd_vma, bfd_getx16, (bfd_byte *));
 167 $  SDEF (void,         bfd_putx16, (bfd_vma, bfd_byte *));
 168
 169 Byte swapping for the headers
 170
 171 $  SDEF (bfd_64_type,   bfd_h_getx64, (bfd_byte *));
 172 $  SDEF (void,          bfd_h_putx64, (bfd_vma, bfd_byte *));
 173 $  SDEF (bfd_vma,  bfd_h_getx32, (bfd_byte *));
 174 $  SDEF (void,          bfd_h_putx32, (bfd_vma, bfd_byte *));
 175 $  SDEF (bfd_vma,  bfd_h_getx16, (bfd_byte *));
 176 $  SDEF (void,          bfd_h_putx16, (bfd_vma, bfd_byte *));
 177
 178 Format dependent routines, these turn into vectors of entry points
 179 within the target vector structure; one for each format to check.
 180
 181 Check the format of a file being read.  Return bfd_target * or zero.
 182
 183 $  SDEF_FMT (struct bfd_target *, _bfd_check_format, (bfd *));
 184
 185 Set the format of a file being written.
 186
 187 $  SDEF_FMT (boolean,            _bfd_set_format, (bfd *));
 188
 189 Write cached information into a file being written, at bfd_close.
 190
 191 $  SDEF_FMT (boolean,            _bfd_write_contents, (bfd *));
 192
 193 The following functions are defined in @code{JUMP_TABLE}. The idea is
 194 that the back end writer of @code{foo} names all the routines
 195 @code{foo_}@var{entry_point}, @code{JUMP_TABLE} will built the entries
 196 in this structure in the right order.
 197
 198 Core file entry points
 199
 200 $  SDEF (char *, _core_file_failing_command, (bfd *));
 201 $  SDEF (int,    _core_file_failing_signal, (bfd *));
 202 $  SDEF (boolean, _core_file_matches_executable_p, (bfd *, bfd *));
 203
 204 Archive entry points
 205
 206 $ SDEF (boolean, _bfd_slurp_armap, (bfd *));
 207 $ SDEF (boolean, _bfd_slurp_extended_name_table, (bfd *));
 208 $ SDEF (void,   _bfd_truncate_arname, (bfd *, CONST char *, char *));
 209 $ SDEF (boolean, write_armap, (bfd *arch,
 210 $                              unsigned int elength,
 211 $                              struct orl *map,
 212 $                              int orl_count,
 213 $                              int stridx));
 214
 215 Standard stuff.
 216
 217 $  SDEF (boolean, _close_and_cleanup, (bfd *));
 218 $  SDEF (boolean, _bfd_set_section_contents, (bfd *, sec_ptr, PTR,
 219 $                                            file_ptr, bfd_size_type));
 220 $  SDEF (boolean, _bfd_get_section_contents, (bfd *, sec_ptr, PTR,
 221 $                                            file_ptr, bfd_size_type));
 222 $  SDEF (boolean, _new_section_hook, (bfd *, sec_ptr));
 223
 224 Symbols and reloctions
 225
 226 $ SDEF (unsigned int, _get_symtab_upper_bound, (bfd *));
 227 $  SDEF (unsigned int, _bfd_canonicalize_symtab,
 228 $           (bfd *, struct symbol_cache_entry **));
 229 $  SDEF (unsigned int, _get_reloc_upper_bound, (bfd *, sec_ptr));
 230 $  SDEF (unsigned int, _bfd_canonicalize_reloc, (bfd *, sec_ptr, arelent **,
 231 $                                               struct symbol_cache_entry**));
 232 $  SDEF (struct symbol_cache_entry  *, _bfd_make_empty_symbol, (bfd *));
 233 $  SDEF (void,     _bfd_print_symbol, (bfd *, PTR, struct symbol_cache_entry  *,
 234 $                                      bfd_print_symbol_enum_type));
 235 $#define bfd_print_symbol(b,p,s,e) BFD_SEND(b, _bfd_print_symbol, (b,p,s,e))
 236 $  SDEF (alent *,   _get_lineno, (bfd *, struct symbol_cache_entry  *));
 237 $
 238 $  SDEF (boolean,   _bfd_set_arch_mach, (bfd *, enum bfd_architecture,
 239 $                                       unsigned long));
 240 $
 241 $  SDEF (bfd *,  openr_next_archived_file, (bfd *arch, bfd *prev));
 242 $  SDEF (boolean, _bfd_find_nearest_line,
 243 $        (bfd *abfd, struct sec  *section,
 244 $         struct symbol_cache_entry  **symbols,bfd_vma offset,
 245 $        CONST char **file, CONST char **func, unsigned int *line));
 246 $  SDEF (int,    _bfd_stat_arch_elt, (bfd *, struct stat *));
 247 $
 248 $  SDEF (int,    _bfd_sizeof_headers, (bfd *, boolean));
 249 $
 250 $  SDEF (void, _bfd_debug_info_start, (bfd *));
 251 $  SDEF (void, _bfd_debug_info_end, (bfd *));
 252 $  SDEF (void, _bfd_debug_info_accumulate, (bfd *, struct sec  *));
 253
 254 Special entry points for gdb to swap in coff symbol table parts
 255
 256 $  SDEF(void, _bfd_coff_swap_aux_in,(
 257 $       bfd            *abfd ,
 258 $       PTR             ext,
 259 $       int             type,
 260 $       int             class ,
 261 $       PTR             in));
 262 $
 263 $  SDEF(void, _bfd_coff_swap_sym_in,(
 264 $       bfd            *abfd ,
 265 $       PTR             ext,
 266 $       PTR             in));
 267 $
 268 $  SDEF(void, _bfd_coff_swap_lineno_in,  (
 269 $       bfd            *abfd,
 270 $       PTR            ext,
 271 $       PTR             in));
 272 $
 273 $} bfd_target;
 274
 275 *---
 276
 277 */
 278 extern bfd_target ecoff_little_vec;
 279 extern bfd_target ecoff_big_vec;
 280 extern bfd_target sunos_big_vec;
 281 extern bfd_target demo_64_vec;
 282 extern bfd_target srec_vec;
 283 extern bfd_target b_out_vec_little_host;
 284 extern bfd_target b_out_vec_big_host;
 285 extern bfd_target icoff_little_vec;
 286 extern bfd_target icoff_big_vec;
 287 extern bfd_target ieee_vec;
 288 extern bfd_target oasys_vec;
 289 extern bfd_target m88k_bcs_vec;
 290 extern bfd_target m68kcoff_vec;
 291 extern bfd_target i386coff_vec;
 292 extern bfd_target a29kcoff_big_vec;
 293 #ifdef DEFAULT_VECTOR
 294 extern bfd_target DEFAULT_VECTOR;
 295 #endif
 296
 297 #ifdef GNU960
 298 #define ICOFF_LITTLE_VEC        icoff_little_vec
 299 #define ICOFF_BIG_VEC           icoff_big_vec
 300 #define B_OUT_VEC_LITTLE_HOST   b_out_vec_little_host
 301 #define B_OUT_VEC_BIG_HOST      b_out_vec_big_host
 302 #endif /* GNU960 */
 303
 304 #ifndef RESTRICTED
 305 #define ECOFF_LITTLE_VEC        ecoff_little_vec
 306 #define ECOFF_BIG_VEC           ecoff_big_vec
 307 #define ICOFF_LITTLE_VEC        icoff_little_vec
 308 #define ICOFF_BIG_VEC           icoff_big_vec
 309 #define ZB_OUT_VEC_LITTLE_HOST  b_out_vec_little_host
 310 #define ZB_OUT_VEC_BIG_HOST     b_out_vec_big_host
 311 #define SUNOS_VEC_BIG_HOST      sunos_big_vec
 312 #define DEMO_64_VEC             demo_64_vec
 313 #define OASYS_VEC               oasys_vec
 314 #define IEEE_VEC                ieee_vec
 315 #define M88K_BCS_VEC            m88k_bcs_vec
 316 #define SREC_VEC                srec_vec
 317 #define M68KCOFF_VEC            m68kcoff_vec
 318 #define I386COFF_VEC            i386coff_vec
 319 #define A29KCOFF_BIG_VEC        a29kcoff_big_vec
 320 #endif
 321 bfd_target *target_vector[] = {
 322
 323 #ifdef DEFAULT_VECTOR
 324         &DEFAULT_VECTOR,
 325 #endif /* DEFAULT_VECTOR */
 326
 327 #ifdef  I386COFF_VEC
 328         &I386COFF_VEC,
 329 #endif  /* I386COFF_VEC */
 330
 331 #ifdef ECOFF_LITTLE_VEC
 332         &ECOFF_LITTLE_VEC,
 333 #endif
 334
 335 #ifdef ECOFF_BIG_VEC
 336         &ECOFF_BIG_VEC,
 337 #endif
 338 #ifdef IEEE_VEC
 339         &IEEE_VEC,
 340 #endif /* IEEE_VEC */
 341
 342 #ifdef OASYS_VEC
 343         &OASYS_VEC,
 344 #endif /* OASYS_VEC */
 345
 346 #ifdef SUNOS_VEC_BIG_HOST
 347         &SUNOS_VEC_BIG_HOST,
 348 #endif /* SUNOS_BIG_VEC */
 349
 350
 351 #ifdef HOST_64_BIT
 352 #ifdef DEMO_64_VEC
 353         &DEMO_64_VEC,
 354 #endif
 355 #endif
 356
 357 #ifdef M88K_BCS_VEC
 358         &M88K_BCS_VEC,
 359 #endif /* M88K_BCS_VEC */
 360
 361 #ifdef SREC_VEC
 362         &SREC_VEC,
 363 #endif /* SREC_VEC */
 364
 365 #ifdef ICOFF_LITTLE_VEC
 366         &ICOFF_LITTLE_VEC,
 367 #endif /* ICOFF_LITTLE_VEC */
 368
 369 #ifdef ICOFF_BIG_VEC
 370         &ICOFF_BIG_VEC,
 371 #endif /* ICOFF_BIG_VEC */
 372
 373 #ifdef B_OUT_VEC_LITTLE_HOST
 374         &B_OUT_VEC_LITTLE_HOST,
 375 #endif /* B_OUT_VEC_LITTLE_HOST */
 376
 377 #ifdef B_OUT_VEC_BIG_HOST
 378         &B_OUT_VEC_BIG_HOST,
 379 #endif /* B_OUT_VEC_BIG_HOST */
 380
 381 #ifdef  M68KCOFF_VEC
 382         &M68KCOFF_VEC,
 383 #endif  /* M68KCOFF_VEC */
 384
 385 #ifdef  A29KCOFF_BIG_VEC
 386         &A29KCOFF_BIG_VEC,
 387 #endif  /* A29KCOFF_BIG_VEC */
 388
 389         NULL, /* end of list marker */
 390 };
 391
 392
 393 /* default_vector[0] contains either the address of the default vector,
 394    if there is one, or zero if there isn't.  */
 395
 396 bfd_target *default_vector[] = {
 397 #ifdef DEFAULT_VECTOR
 398         &DEFAULT_VECTOR,
 399 #endif
 400         0,
 401 };
 402
 403
 404
 405
 406 /*proto*
 407 *i bfd_find_target
 408 Returns a pointer to the transfer vector for the object target
 409 named target_name.  If target_name is NULL, chooses the one in the
 410 environment variable GNUTARGET; if that is null or not defined then
 411 the first entry in the target list is chosen.  Passing in the
 412 string "default" or setting the environment variable to "default"
 413 will cause the first entry in the target list to be returned,
 414 and "target_defaulted" will be set in the bfd.  This causes
 415 bfd_check_format to loop over all the targets to find the one
 416 that matches the file being read.
 417 *; PROTO(bfd_target *, bfd_find_target,(CONST char *, bfd *));
 418 *-*/
 419
 420 bfd_target *
 421 DEFUN(bfd_find_target,(target_name, abfd),
 422       CONST char *target_name AND
 423       bfd *abfd)
 424 {
 425   bfd_target **target;
 426   extern char *getenv ();
 427   CONST char *targname = (target_name ? target_name : getenv ("GNUTARGET"));
 428
 429   /* This is safe; the vector cannot be null */
 430   if (targname == NULL || !strcmp (targname, "default")) {
 431     abfd->target_defaulted = true;
 432     return abfd->xvec = target_vector[0];
 433   }
 434
 435   abfd->target_defaulted = false;
 436
 437   for (target = &target_vector[0]; *target != NULL; target++) {
 438     if (!strcmp (targname, (*target)->name))
 439       return abfd->xvec = *target;
 440   }
 441
 442   bfd_error = invalid_target;
 443   return NULL;
 444 }
 445
 446
 447 /*proto*
 448 *i bfd_target_list
 449 This function returns a freshly malloced NULL-terminated vector of the
 450 names of all the valid bfd targets. Do not modify the names
 451 *; PROTO(CONST char **,bfd_target_list,());
 452
 453 *-*/
 454
 455 CONST char **
 456 DEFUN_VOID(bfd_target_list)
 457 {
 458   int vec_length= 0;
 459   bfd_target **target;
 460 CONST  char **name_list, **name_ptr;
 461
 462   for (target = &target_vector[0]; *target != NULL; target++)
 463     vec_length++;
 464
 465   name_ptr =
 466     name_list = (CONST char **) zalloc ((vec_length + 1) * sizeof (char **));
 467
 468   if (name_list == NULL) {
 469     bfd_error = no_memory;
 470     return NULL;
 471   }
 472
 473
 474
 475   for (target = &target_vector[0]; *target != NULL; target++)
 476     *(name_ptr++) = (*target)->name;
 477
 478   return name_list;
 479 }