bfd/bfd.c

   1 /* Generic BFD library interface and support routines.
   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 /*
  22 SECTION
  23         <<typedef bfd>>
  24
  25         A BFD is has type <<bfd>>; objects of this type are the
  26         cornerstone of any application using <<libbfd>>. References
  27         though the BFD and to data in the BFD give the entire BFD
  28         functionality.
  29
  30         Here is the struct used to define the type <<bfd>>.  This
  31         contains the major data about the file, and contains pointers
  32         to the rest of the data.
  33
  34 CODE_FRAGMENT
  35 .
  36 .struct _bfd
  37 .{
  38 .    {* The filename the application opened the BFD with.  *}
  39 .    CONST char *filename;
  40 .
  41 .    {* A pointer to the target jump table.             *}
  42 .    struct bfd_target *xvec;
  43 .
  44 .    {* To avoid dragging too many header files into every file that
  45 .       includes `<<bfd.h>>', IOSTREAM has been declared as a "char
  46 .       *", and MTIME as a "long".  Their correct types, to which they
  47 .       are cast when used, are "FILE *" and "time_t".    The iostream
  48 .       is the result of an fopen on the filename. *}
  49 .    char *iostream;
  50 .
  51 .    {* Is the file being cached *}
  52 .
  53 .    boolean cacheable;
  54 .
  55 .    {* Marks whether there was a default target specified when the
  56 .       BFD was opened. This is used to select what matching algorithm
  57 .       to use to chose the back end. *}
  58 .
  59 .    boolean target_defaulted;
  60 .
  61 .    {* The caching routines use these to maintain a
  62 .       least-recently-used list of BFDs *}
  63 .
  64 .    struct _bfd *lru_prev, *lru_next;
  65 .
  66 .    {* When a file is closed by the caching routines, BFD retains
  67 .       state information on the file here:
  68 .     *}
  69 .
  70 .    file_ptr where;
  71 .
  72 .    {* and here:*}
  73 .
  74 .    boolean opened_once;
  75 .
  76 .    {* Set if we have a locally maintained mtime value, rather than
  77 .       getting it from the file each time: *}
  78 .
  79 .    boolean mtime_set;
  80 .
  81 .    {* File modified time, if mtime_set is true: *}
  82 .
  83 .    long mtime;
  84 .
  85 .    {* Reserved for an unimplemented file locking extension.*}
  86 .
  87 .    int ifd;
  88 .
  89 .    {* The format which belongs to the BFD.*}
  90 .
  91 .    bfd_format format;
  92 .
  93 .    {* The direction the BFD was opened with*}
  94 .
  95 .    enum bfd_direction {no_direction = 0,
  96 .                        read_direction = 1,
  97 .                        write_direction = 2,
  98 .                        both_direction = 3} direction;
  99 .
 100 .    {* Format_specific flags*}
 101 .
 102 .    flagword flags;
 103 .
 104 .    {* Currently my_archive is tested before adding origin to
 105 .       anything. I believe that this can become always an add of
 106 .       origin, with origin set to 0 for non archive files.   *}
 107 .
 108 .    file_ptr origin;
 109 .
 110 .    {* Remember when output has begun, to stop strange things
 111 .       happening. *}
 112 .    boolean output_has_begun;
 113 .
 114 .    {* Pointer to linked list of sections*}
 115 .    struct sec  *sections;
 116 .
 117 .    {* The number of sections *}
 118 .    unsigned int section_count;
 119 .
 120 .    {* Stuff only useful for object files:
 121 .       The start address. *}
 122 .    bfd_vma start_address;
 123 .
 124 .    {* Used for input and output*}
 125 .    unsigned int symcount;
 126 .
 127 .    {* Symbol table for output BFD*}
 128 .    struct symbol_cache_entry  **outsymbols;
 129 .
 130 .    {* Pointer to structure which contains architecture information*}
 131 .    struct bfd_arch_info *arch_info;
 132 .
 133 .    {* Stuff only useful for archives:*}
 134 .    PTR arelt_data;
 135 .    struct _bfd *my_archive;
 136 .    struct _bfd *next;
 137 .    struct _bfd *archive_head;
 138 .    boolean has_armap;
 139 .
 140 .    {* Used by the back end to hold private data. *}
 141 .
 142 .    union
 143 .      {
 144 .      struct aout_data_struct *aout_data;
 145 .      struct artdata *aout_ar_data;
 146 .      struct _oasys_data *oasys_obj_data;
 147 .      struct _oasys_ar_data *oasys_ar_data;
 148 .      struct coff_tdata *coff_obj_data;
 149 .      struct ieee_data_struct *ieee_data;
 150 .      struct ieee_ar_data_struct *ieee_ar_data;
 151 .      struct srec_data_struct *srec_data;
 152 .      struct tekhex_data_struct *tekhex_data;
 153 .      struct elf_obj_tdata *elf_obj_data;
 154 .      struct bout_data_struct *bout_data;
 155 .      struct sun_core_struct *sun_core_data;
 156 .      struct trad_core_struct *trad_core_data;
 157 .      struct hppa_data_struct *hppa_data;
 158 .      PTR any;
 159 .      } tdata;
 160 .
 161 .    {* Used by the application to hold private data*}
 162 .    PTR usrdata;
 163 .
 164 .    {* Where all the allocated stuff under this BFD goes *}
 165 .    struct obstack memory;
 166 .
 167 .    {* Is this really needed in addition to usrdata?  *}
 168 .    asymbol **ld_symbols;
 169 .};
 170 .
 171 */
 172
 173 #include "bfd.h"
 174 #include "sysdep.h"
 175 #include "libbfd.h"
 176
 177 #undef strerror
 178 extern char *strerror();
 179
 180
 181 CONST short _bfd_host_big_endian = 0x0100;
 182         /* Accessing the above as (*(char*)&_bfd_host_big_endian), will
 183            return 1 if the host is big-endian, 0 otherwise.
 184            (assuming that a short is two bytes long!!!  FIXME)
 185            (See HOST_IS_BIG_ENDIAN_P in bfd.h.)  */
 186 \f
 187 /** Error handling
 188     o - Most functions return nonzero on success (check doc for
 189         precise semantics); 0 or NULL on error.
 190     o - Internal errors are documented by the value of bfd_error.
 191         If that is system_call_error then check errno.
 192     o - The easiest way to report this to the user is to use bfd_perror.
 193 */
 194
 195 bfd_ec bfd_error = no_error;
 196
 197 CONST char *CONST bfd_errmsgs[] = { "No error",
 198                         "System call error",
 199                         "Invalid target",
 200                         "File in wrong format",
 201                         "Invalid operation",
 202                         "Memory exhausted",
 203                         "No symbols",
 204                         "No relocation info",
 205                         "No more archived files",
 206                         "Malformed archive",
 207                         "Symbol not found",
 208                         "File format not recognized",
 209                         "File format is ambiguous",
 210                         "Section has no contents",
 211                         "Nonrepresentable section on output",
 212                         "Symbol needs debug section which does not exist",
 213                         "Bad value",
 214                         "#<Invalid error code>"
 215                        };
 216
 217 static
 218 void
 219 DEFUN(bfd_nonrepresentable_section,(abfd, name),
 220          CONST  bfd * CONST abfd AND
 221          CONST  char * CONST name)
 222 {
 223   printf("bfd error writing file %s, format %s can't represent section %s\n",
 224          abfd->filename,
 225          abfd->xvec->name,
 226          name);
 227   exit(1);
 228 }
 229
 230 /*ARGSUSED*/
 231 static
 232 void
 233 DEFUN(bfd_undefined_symbol,(relent, seclet),
 234       CONST  arelent *relent AND
 235       CONST  struct bfd_seclet *seclet)
 236 {
 237   asymbol *symbol = *(relent->sym_ptr_ptr);
 238   printf("bfd error relocating, symbol %s is undefined\n",
 239          symbol->name);
 240   exit(1);
 241 }
 242 /*ARGSUSED*/
 243 static
 244 void
 245 DEFUN(bfd_reloc_value_truncated,(relent, seclet),
 246          CONST  arelent *relent AND
 247       struct bfd_seclet *seclet)
 248 {
 249   printf("bfd error relocating, value truncated\n");
 250   exit(1);
 251 }
 252 /*ARGSUSED*/
 253 static
 254 void
 255 DEFUN(bfd_reloc_is_dangerous,(relent, seclet),
 256       CONST  arelent *relent AND
 257      CONST  struct bfd_seclet *seclet)
 258 {
 259   printf("bfd error relocating, dangerous\n");
 260   exit(1);
 261 }
 262
 263 bfd_error_vector_type bfd_error_vector =
 264   {
 265   bfd_nonrepresentable_section ,
 266   bfd_undefined_symbol,
 267   bfd_reloc_value_truncated,
 268   bfd_reloc_is_dangerous,
 269   };
 270
 271
 272 CONST char *
 273 bfd_errmsg (error_tag)
 274      bfd_ec error_tag;
 275 {
 276 #ifndef errno
 277   extern int errno;
 278 #endif
 279   if (error_tag == system_call_error)
 280     return strerror (errno);
 281
 282   if ((((int)error_tag <(int) no_error) ||
 283        ((int)error_tag > (int)invalid_error_code)))
 284     error_tag = invalid_error_code;/* sanity check */
 285
 286   return bfd_errmsgs [(int)error_tag];
 287 }
 288
 289
 290 void bfd_default_error_trap(error_tag)
 291 bfd_ec error_tag;
 292 {
 293   printf("bfd assert fail (%s)\n", bfd_errmsg(error_tag));
 294 }
 295
 296 void (*bfd_error_trap)() = bfd_default_error_trap;
 297 void (*bfd_error_nonrepresentabltrap)() = bfd_default_error_trap;
 298
 299 void
 300 DEFUN(bfd_perror,(message),
 301       CONST char *message)
 302 {
 303   if (bfd_error == system_call_error)
 304     perror((char *)message);            /* must be system error then... */
 305   else {
 306     if (message == NULL || *message == '\0')
 307       fprintf (stderr, "%s\n", bfd_errmsg (bfd_error));
 308     else
 309       fprintf (stderr, "%s: %s\n", message, bfd_errmsg (bfd_error));
 310   }
 311 }
 312
 313  \f
 314 /** Symbols */
 315
 316
 317 /*
 318 FUNCTION
 319         bfd_get_reloc_upper_bound
 320
 321 SYNOPSIS
 322         unsigned int bfd_get_reloc_upper_bound(bfd *abfd, asection *sect);
 323
 324 DESCRIPTION
 325         This function return the number of bytes required to store the
 326         relocation information associated with section <<sect>>
 327         attached to bfd <<abfd>>
 328
 329 */
 330
 331
 332 unsigned int
 333 DEFUN(bfd_get_reloc_upper_bound,(abfd, asect),
 334      bfd *abfd AND
 335      sec_ptr asect)
 336 {
 337   if (abfd->format != bfd_object) {
 338     bfd_error = invalid_operation;
 339     return 0;
 340   }
 341
 342   return BFD_SEND (abfd, _get_reloc_upper_bound, (abfd, asect));
 343 }
 344
 345 /*
 346 FUNCTION
 347         bfd_canonicalize_reloc
 348
 349 SYNOPSIS
 350         unsigned int bfd_canonicalize_reloc
 351                 (bfd *abfd,
 352                 asection *sec,
 353                 arelent **loc,
 354                 asymbol **syms);
 355
 356 DESCRIPTION
 357         This function calls the back end associated with the open
 358         <<abfd>> and translates the external form of the relocation
 359         information attached to <<sec>> into the internal canonical
 360         form.  The table is placed into memory at <<loc>>, which has
 361         been preallocated, usually by a call to
 362         <<bfd_get_reloc_upper_bound>>.
 363
 364         The <<syms>> table is also needed for horrible internal magic
 365         reasons.
 366
 367
 368 */
 369 unsigned int
 370 DEFUN(bfd_canonicalize_reloc,(abfd, asect, location, symbols),
 371      bfd *abfd AND
 372      sec_ptr asect AND
 373      arelent **location AND
 374      asymbol **symbols)
 375 {
 376     if (abfd->format != bfd_object) {
 377             bfd_error = invalid_operation;
 378             return 0;
 379         }
 380     return BFD_SEND (abfd, _bfd_canonicalize_reloc,
 381                      (abfd, asect, location, symbols));
 382   }
 383
 384
 385 /*
 386 FUNCTION
 387         bfd_set_file_flags
 388
 389 SYNOPSIS
 390         boolean bfd_set_file_flags(bfd *abfd, flagword flags);
 391
 392 DESCRIPTION
 393         This function attempts to set the flag word in the referenced
 394         BFD structure to the value supplied.
 395
 396         Possible errors are:
 397         o wrong_format - The target bfd was not of object format.
 398         o invalid_operation - The target bfd was open for reading.
 399         o invalid_operation -
 400         The flag word contained a bit which was not applicable to the
 401         type of file. eg, an attempt was made to set the D_PAGED bit
 402         on a bfd format which does not support demand paging
 403
 404 */
 405
 406 boolean
 407 bfd_set_file_flags (abfd, flags)
 408      bfd *abfd;
 409      flagword flags;
 410 {
 411   if (abfd->format != bfd_object) {
 412     bfd_error = wrong_format;
 413     return false;
 414   }
 415
 416   if (bfd_read_p (abfd)) {
 417     bfd_error = invalid_operation;
 418     return false;
 419   }
 420
 421   bfd_get_file_flags (abfd) = flags;
 422   if ((flags & bfd_applicable_file_flags (abfd)) != flags) {
 423     bfd_error = invalid_operation;
 424     return false;
 425   }
 426
 427 return true;
 428 }
 429
 430 /*
 431 FUNCTION
 432         bfd_set_reloc
 433
 434 SYNOPSIS
 435         void bfd_set_reloc
 436           (bfd *abfd, asection *sec, arelent **rel, unsigned int count)
 437
 438 DESCRIPTION
 439         This function sets the relocation pointer and count within a
 440         section to the supplied values.
 441
 442 */
 443 /*ARGSUSED*/
 444 void
 445 bfd_set_reloc (ignore_abfd, asect, location, count)
 446      bfd *ignore_abfd;
 447      sec_ptr asect;
 448      arelent **location;
 449      unsigned int count;
 450 {
 451   asect->orelocation  = location;
 452   asect->reloc_count = count;
 453 }
 454
 455 void
 456 bfd_assert(file, line)
 457 char *file;
 458 int line;
 459 {
 460   printf("bfd assertion fail %s:%d\n",file,line);
 461 }
 462
 463
 464 /*
 465 FUNCTION
 466         bfd_set_start_address
 467
 468 DESCRIPTION
 469         Marks the entry point of an output BFD.
 470
 471 RETURNS
 472         Returns <<true>> on success, <<false>> otherwise.
 473
 474 SYNOPSIS
 475         boolean bfd_set_start_address(bfd *, bfd_vma);
 476 */
 477
 478 boolean
 479 bfd_set_start_address(abfd, vma)
 480 bfd *abfd;
 481 bfd_vma vma;
 482 {
 483   abfd->start_address = vma;
 484   return true;
 485 }
 486
 487
 488 /*
 489 FUNCTION
 490         The bfd_get_mtime function
 491
 492 SYNOPSIS
 493         long bfd_get_mtime(bfd *);
 494
 495 DESCRIPTION
 496         Return file modification time (as read from file system, or
 497         from archive header for archive members).
 498
 499 */
 500
 501 long
 502 bfd_get_mtime (abfd)
 503      bfd *abfd;
 504 {
 505   FILE *fp;
 506   struct stat buf;
 507
 508   if (abfd->mtime_set)
 509     return abfd->mtime;
 510
 511   fp = bfd_cache_lookup (abfd);
 512   if (0 != fstat (fileno (fp), &buf))
 513     return 0;
 514
 515   abfd->mtime = buf.st_mtime;           /* Save value in case anyone wants it */
 516   return buf.st_mtime;
 517 }
 518
 519 /*
 520 FUNCTION
 521         stuff
 522
 523 DESCRIPTION
 524         stuff which should be documented
 525
 526 .#define bfd_sizeof_headers(abfd, reloc) \
 527 .     BFD_SEND (abfd, _bfd_sizeof_headers, (abfd, reloc))
 528 .
 529 .#define bfd_find_nearest_line(abfd, sec, syms, off, file, func, line) \
 530 .     BFD_SEND (abfd, _bfd_find_nearest_line,  (abfd, sec, syms, off, file, func, line))
 531 .
 532 .       {* Do these three do anything useful at all, for any back end?  *}
 533 .#define bfd_debug_info_start(abfd) \
 534 .        BFD_SEND (abfd, _bfd_debug_info_start, (abfd))
 535 .
 536 .#define bfd_debug_info_end(abfd) \
 537 .        BFD_SEND (abfd, _bfd_debug_info_end, (abfd))
 538 .
 539 .#define bfd_debug_info_accumulate(abfd, section) \
 540 .        BFD_SEND (abfd, _bfd_debug_info_accumulate, (abfd, section))
 541 .
 542 .
 543 .#define bfd_stat_arch_elt(abfd, stat) \
 544 .        BFD_SEND (abfd, _bfd_stat_arch_elt,(abfd, stat))
 545 .
 546 .#define bfd_set_arch_mach(abfd, arch, mach)\
 547 .        BFD_SEND ( abfd, _bfd_set_arch_mach, (abfd, arch, mach))
 548 .
 549 .#define bfd_get_relocated_section_contents(abfd, seclet, data) \
 550 .       BFD_SEND (abfd, _bfd_get_relocated_section_contents, (abfd, seclet, data))
 551 .
 552 .#define bfd_relax_section(abfd, section, symbols) \
 553 .       BFD_SEND (abfd, _bfd_relax_section, (abfd, section, symbols))
 554
 555 */
 556
 557
 558
 559
 560
 561