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 operatios 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_ieee_flavour_enum,
 126 $    bfd_target_oasys_flavour_enum,
 127 $    bfd_target_srec_flavour_enum} flavour;
 128
 129 The order of bytes within the data area of a file.
 130
 131 $  boolean byteorder_big_p;
 132
 133 The order of bytes within the header parts of a file.
 134
 135 $  boolean header_byteorder_big_p;
 136
 137 This is a mask of all the flags which an executable may have set -
 138 from the set @code{NO_FLAGS}, @code{HAS_RELOC}, ...@code{D_PAGED}.
 139
 140 $  flagword object_flags;
 141
 142 This is a mask of all the flags which a section may have set - from
 143 the set @code{SEC_NO_FLAGS}, @code{SEC_ALLOC}, ...@code{SET_NEVER_LOAD}.
 144
 145 $  flagword section_flags;
 146
 147 The pad character for filenames within an archive header.
 148
 149 $  char ar_pad_char;
 150
 151 The maximum number of characters in an archive header.
 152
 153 $ unsigned short ar_max_namelen;
 154
 155 The minimum alignment restriction for any section.
 156
 157 $  unsigned int align_power_min;
 158
 159 Entries for byte swapping for data. These are different to the other
 160 entry points, since they don't take BFD as first arg.  Certain other handlers
 161 could do the same.
 162
 163 $  SDEF (bfd_vma,      bfd_getx64, (bfd_byte *));
 164 $  SDEF (void,         bfd_putx64, (bfd_vma, bfd_byte *));
 165 $  SDEF (bfd_vma, bfd_getx32, (bfd_byte *));
 166 $  SDEF (void,         bfd_putx32, (bfd_vma, bfd_byte *));
 167 $  SDEF (bfd_vma, bfd_getx16, (bfd_byte *));
 168 $  SDEF (void,         bfd_putx16, (bfd_vma, bfd_byte *));
 169
 170 Byte swapping for the headers
 171
 172 $  SDEF (bfd_vma,   bfd_h_getx64, (bfd_byte *));
 173 $  SDEF (void,          bfd_h_putx64, (bfd_vma, bfd_byte *));
 174 $  SDEF (bfd_vma,  bfd_h_getx32, (bfd_byte *));
 175 $  SDEF (void,          bfd_h_putx32, (bfd_vma, bfd_byte *));
 176 $  SDEF (bfd_vma,  bfd_h_getx16, (bfd_byte *));
 177 $  SDEF (void,          bfd_h_putx16, (bfd_vma, bfd_byte *));
 178
 179 Format dependent routines, these turn into vectors of entry points
 180 within the target vector structure; one for each format to check.
 181
 182 Check the format of a file being read.  Return bfd_target * or zero.
 183
 184 $  SDEF_FMT (struct bfd_target *, _bfd_check_format, (bfd *));
 185
 186 Set the format of a file being written.
 187
 188 $  SDEF_FMT (boolean,            _bfd_set_format, (bfd *));
 189
 190 Write cached information into a file being written, at bfd_close.
 191
 192 $  SDEF_FMT (boolean,            _bfd_write_contents, (bfd *));
 193
 194 The following functions are defined in @code{JUMP_TABLE}. The idea is
 195 that the back end writer of @code{foo} names all the routines
 196 @code{foo_}@var{entry_point}, @code{JUMP_TABLE} will built the entries
 197 in this structure in the right order.
 198
 199 Core file entry points
 200
 201 $  SDEF (char *, _core_file_failing_command, (bfd *));
 202 $  SDEF (int,    _core_file_failing_signal, (bfd *));
 203 $  SDEF (boolean, _core_file_matches_executable_p, (bfd *, bfd *));
 204
 205 Archive entry points
 206
 207 $ SDEF (boolean, _bfd_slurp_armap, (bfd *));
 208 $ SDEF (boolean, _bfd_slurp_extended_name_table, (bfd *));
 209 $ SDEF (void,   _bfd_truncate_arname, (bfd *, CONST char *, char *));
 210 $ SDEF (boolean, write_armap, (bfd *arch,
 211 $                              unsigned int elength,
 212 $                              struct orl *map,
 213 $                              int orl_count,
 214 $                              int stridx));
 215
 216 Standard stuff.
 217
 218 $  SDEF (boolean, _close_and_cleanup, (bfd *));
 219 $  SDEF (boolean, _bfd_set_section_contents, (bfd *, sec_ptr, PTR,
 220 $                                            file_ptr, bfd_size_type));
 221 $  SDEF (boolean, _bfd_get_section_contents, (bfd *, sec_ptr, PTR,
 222 $                                            file_ptr, bfd_size_type));
 223 $  SDEF (boolean, _new_section_hook, (bfd *, sec_ptr));
 224
 225 Symbols and reloctions
 226
 227 $ SDEF (unsigned int, _get_symtab_upper_bound, (bfd *));
 228 $  SDEF (unsigned int, _bfd_canonicalize_symtab,
 229 $           (bfd *, struct symbol_cache_entry **));
 230 $  SDEF (unsigned int, _get_reloc_upper_bound, (bfd *, sec_ptr));
 231 $  SDEF (unsigned int, _bfd_canonicalize_reloc, (bfd *, sec_ptr, arelent **,
 232 $                                               struct symbol_cache_entry**));
 233 $  SDEF (struct symbol_cache_entry  *, _bfd_make_empty_symbol, (bfd *));
 234 $  SDEF (void,     _bfd_print_symbol, (bfd *, PTR, struct symbol_cache_entry  *,
 235 $                                      bfd_print_symbol_enum_type));
 236 $#define bfd_print_symbol(b,p,s,e) BFD_SEND(b, _bfd_print_symbol, (b,p,s,e))
 237 $  SDEF (alent *,   _get_lineno, (bfd *, struct symbol_cache_entry  *));
 238 $
 239 $  SDEF (boolean,   _bfd_set_arch_mach, (bfd *, enum bfd_architecture,
 240 $                                       unsigned long));
 241 $
 242 $  SDEF (bfd *,  openr_next_archived_file, (bfd *arch, bfd *prev));
 243 $  SDEF (boolean, _bfd_find_nearest_line,
 244 $        (bfd *abfd, struct sec  *section,
 245 $         struct symbol_cache_entry  **symbols,bfd_vma offset,
 246 $        CONST char **file, CONST char **func, unsigned int *line));
 247 $  SDEF (int,    _bfd_stat_arch_elt, (bfd *, struct stat *));
 248 $
 249 $  SDEF (int,    _bfd_sizeof_headers, (bfd *, boolean));
 250 $
 251 $  SDEF (void, _bfd_debug_info_start, (bfd *));
 252 $  SDEF (void, _bfd_debug_info_end, (bfd *));
 253 $  SDEF (void, _bfd_debug_info_accumulate, (bfd *, struct sec  *));
 254
 255 Special entry points for gdb to swap in coff symbol table parts
 256
 257 $  SDEF(void, _bfd_coff_swap_aux_in,(
 258 $       bfd            *abfd ,
 259 $       PTR             ext,
 260 $       int             type,
 261 $       int             class ,
 262 $       PTR             in));
 263 $
 264 $  SDEF(void, _bfd_coff_swap_sym_in,(
 265 $       bfd            *abfd ,
 266 $       PTR             ext,
 267 $       PTR             in));
 268 $
 269 $  SDEF(void, _bfd_coff_swap_lineno_in,  (
 270 $       bfd            *abfd,
 271 $       PTR            ext,
 272 $       PTR             in));
 273 $
 274 $} bfd_target;
 275
 276 *---
 277
 278 */
 279 extern bfd_target ecoff_little_vec;
 280 extern bfd_target ecoff_big_vec;
 281 extern bfd_target sunos_big_vec;
 282 extern bfd_target demo_64_vec;
 283 extern bfd_target srec_vec;
 284 extern bfd_target b_out_vec_little_host;
 285 extern bfd_target b_out_vec_big_host;
 286 extern bfd_target icoff_little_vec;
 287 extern bfd_target icoff_big_vec;
 288 extern bfd_target ieee_vec;
 289 extern bfd_target oasys_vec;
 290 extern bfd_target m88k_bcs_vec;
 291 extern bfd_target m68kcoff_vec;
 292 extern bfd_target i386coff_vec;
 293 extern bfd_target a29kcoff_big_vec;
 294
 295 #ifdef SELECT_VECS
 296
 297 bfd_target *target_vector[] = {
 298 SELECT_VECS,
 299 0
 300
 301 };
 302 #else
 303 #ifdef DEFAULT_VECTOR
 304 extern bfd_target DEFAULT_VECTOR;
 305 #endif
 306
 307 #ifdef GNU960
 308 #define ICOFF_LITTLE_VEC        icoff_little_vec
 309 #define ICOFF_BIG_VEC           icoff_big_vec
 310 #define B_OUT_VEC_LITTLE_HOST   b_out_vec_little_host
 311 #define B_OUT_VEC_BIG_HOST      b_out_vec_big_host
 312 #endif /* GNU960 */
 313
 314 #ifndef RESTRICTED
 315 #define ECOFF_LITTLE_VEC        ecoff_little_vec
 316 #define ECOFF_BIG_VEC           ecoff_big_vec
 317 #define ICOFF_LITTLE_VEC        icoff_little_vec
 318 #define ICOFF_BIG_VEC           icoff_big_vec
 319 #define ZB_OUT_VEC_LITTLE_HOST  b_out_vec_little_host
 320 #define ZB_OUT_VEC_BIG_HOST     b_out_vec_big_host
 321 #define SUNOS_VEC_BIG_HOST      sunos_big_vec
 322 #define DEMO_64_VEC             demo_64_vec
 323 #define OASYS_VEC               oasys_vec
 324 #define IEEE_VEC                ieee_vec
 325 #define M88K_BCS_VEC            m88k_bcs_vec
 326 #define SREC_VEC                srec_vec
 327 #define M68KCOFF_VEC            m68kcoff_vec
 328 #define I386COFF_VEC            i386coff_vec
 329 #define A29KCOFF_BIG_VEC        a29kcoff_big_vec
 330 #endif
 331
 332 bfd_target *target_vector[] = {
 333
 334 #ifdef DEFAULT_VECTOR
 335         &DEFAULT_VECTOR,
 336 #endif /* DEFAULT_VECTOR */
 337
 338 #ifdef  I386COFF_VEC
 339         &I386COFF_VEC,
 340 #endif  /* I386COFF_VEC */
 341
 342 #ifdef ECOFF_LITTLE_VEC
 343         &ECOFF_LITTLE_VEC,
 344 #endif
 345
 346 #ifdef ECOFF_BIG_VEC
 347         &ECOFF_BIG_VEC,
 348 #endif
 349 #ifdef IEEE_VEC
 350         &IEEE_VEC,
 351 #endif /* IEEE_VEC */
 352
 353 #ifdef OASYS_VEC
 354         &OASYS_VEC,
 355 #endif /* OASYS_VEC */
 356
 357 #ifdef SUNOS_VEC_BIG_HOST
 358         &SUNOS_VEC_BIG_HOST,
 359 #endif /* SUNOS_BIG_VEC */
 360
 361
 362 #ifdef HOST_64_BIT
 363 #ifdef DEMO_64_VEC
 364         &DEMO_64_VEC,
 365 #endif
 366 #endif
 367
 368 #ifdef M88K_BCS_VEC
 369         &M88K_BCS_VEC,
 370 #endif /* M88K_BCS_VEC */
 371
 372 #ifdef SREC_VEC
 373         &SREC_VEC,
 374 #endif /* SREC_VEC */
 375
 376 #ifdef ICOFF_LITTLE_VEC
 377         &ICOFF_LITTLE_VEC,
 378 #endif /* ICOFF_LITTLE_VEC */
 379
 380 #ifdef ICOFF_BIG_VEC
 381         &ICOFF_BIG_VEC,
 382 #endif /* ICOFF_BIG_VEC */
 383
 384 #ifdef B_OUT_VEC_LITTLE_HOST
 385         &B_OUT_VEC_LITTLE_HOST,
 386 #endif /* B_OUT_VEC_LITTLE_HOST */
 387
 388 #ifdef B_OUT_VEC_BIG_HOST
 389         &B_OUT_VEC_BIG_HOST,
 390 #endif /* B_OUT_VEC_BIG_HOST */
 391
 392 #ifdef  M68KCOFF_VEC
 393         &M68KCOFF_VEC,
 394 #endif  /* M68KCOFF_VEC */
 395
 396 #ifdef  A29KCOFF_BIG_VEC
 397         &A29KCOFF_BIG_VEC,
 398 #endif  /* A29KCOFF_BIG_VEC */
 399
 400         NULL, /* end of list marker */
 401 };
 402
 403 #endif
 404
 405 /* default_vector[0] contains either the address of the default vector,
 406    if there is one, or zero if there isn't.  */
 407
 408 bfd_target *default_vector[] = {
 409 #ifdef DEFAULT_VECTOR
 410         &DEFAULT_VECTOR,
 411 #endif
 412         0,
 413 };
 414
 415
 416
 417
 418 /*proto*
 419 *i bfd_find_target
 420 Returns a pointer to the transfer vector for the object target
 421 named target_name.  If target_name is NULL, chooses the one in the
 422 environment variable GNUTARGET; if that is null or not defined then
 423 the first entry in the target list is chosen.  Passing in the
 424 string "default" or setting the environment variable to "default"
 425 will cause the first entry in the target list to be returned,
 426 and "target_defaulted" will be set in the BFD.  This causes
 427 @code{bfd_check_format} to loop over all the targets to find the one
 428 that matches the file being read.
 429 *; PROTO(bfd_target *, bfd_find_target,(CONST char *, bfd *));
 430 *-*/
 431
 432 bfd_target *
 433 DEFUN(bfd_find_target,(target_name, abfd),
 434       CONST char *target_name AND
 435       bfd *abfd)
 436 {
 437   bfd_target **target;
 438   extern char *getenv ();
 439   CONST char *targname = (target_name ? target_name : getenv ("GNUTARGET"));
 440
 441   /* This is safe; the vector cannot be null */
 442   if (targname == NULL || !strcmp (targname, "default")) {
 443     abfd->target_defaulted = true;
 444     return abfd->xvec = target_vector[0];
 445   }
 446
 447   abfd->target_defaulted = false;
 448
 449   for (target = &target_vector[0]; *target != NULL; target++) {
 450     if (!strcmp (targname, (*target)->name))
 451       return abfd->xvec = *target;
 452   }
 453
 454   bfd_error = invalid_target;
 455   return NULL;
 456 }
 457
 458
 459 /*proto*
 460 *i bfd_target_list
 461 This function returns a freshly malloced NULL-terminated vector of the
 462 names of all the valid BFD targets. Do not modify the names
 463 *; PROTO(CONST char **,bfd_target_list,());
 464
 465 *-*/
 466
 467 CONST char **
 468 DEFUN_VOID(bfd_target_list)
 469 {
 470   int vec_length= 0;
 471   bfd_target **target;
 472   CONST  char **name_list, **name_ptr;
 473
 474   for (target = &target_vector[0]; *target != NULL; target++)
 475     vec_length++;
 476
 477   name_ptr =
 478     name_list = (CONST char **) zalloc ((vec_length + 1) * sizeof (char **));
 479
 480   if (name_list == NULL) {
 481     bfd_error = no_memory;
 482     return NULL;
 483   }
 484
 485   for (target = &target_vector[0]; *target != NULL; target++)
 486     *(name_ptr++) = (*target)->name;
 487
 488   return name_list;
 489 }