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 .      struct hppa_core_struct *hppa_core_data;
 159 .      PTR any;
 160 .      } tdata;
 161 .
 162 .    {* Used by the application to hold private data*}
 163 .    PTR usrdata;
 164 .
 165 .    {* Where all the allocated stuff under this BFD goes *}
 166 .    struct obstack memory;
 167 .
 168 .    {* Is this really needed in addition to usrdata?  *}
 169 .    asymbol **ld_symbols;
 170 .};
 171 .
 172 */
 173
 174 #include "bfd.h"
 175 #include "sysdep.h"
 176 #include "libbfd.h"
 177
 178 #undef strerror
 179 extern char *strerror();
 180
 181
 182 CONST short _bfd_host_big_endian = 0x0100;
 183         /* Accessing the above as (*(char*)&_bfd_host_big_endian), will
 184            return 1 if the host is big-endian, 0 otherwise.
 185            (assuming that a short is two bytes long!!!  FIXME)
 186            (See HOST_IS_BIG_ENDIAN_P in bfd.h.)  */
 187 \f
 188 /** Error handling
 189     o - Most functions return nonzero on success (check doc for
 190         precise semantics); 0 or NULL on error.
 191     o - Internal errors are documented by the value of bfd_error.
 192         If that is system_call_error then check errno.
 193     o - The easiest way to report this to the user is to use bfd_perror.
 194 */
 195
 196 bfd_ec bfd_error = no_error;
 197
 198 CONST char *CONST bfd_errmsgs[] = { "No error",
 199                         "System call error",
 200                         "Invalid target",
 201                         "File in wrong format",
 202                         "Invalid operation",
 203                         "Memory exhausted",
 204                         "No symbols",
 205                         "No relocation info",
 206                         "No more archived files",
 207                         "Malformed archive",
 208                         "Symbol not found",
 209                         "File format not recognized",
 210                         "File format is ambiguous",
 211                         "Section has no contents",
 212                         "Nonrepresentable section on output",
 213                         "Symbol needs debug section which does not exist",
 214                         "Bad value",
 215                         "#<Invalid error code>"
 216                        };
 217
 218 static
 219 void
 220 DEFUN(bfd_nonrepresentable_section,(abfd, name),
 221          CONST  bfd * CONST abfd AND
 222          CONST  char * CONST name)
 223 {
 224   printf("bfd error writing file %s, format %s can't represent section %s\n",
 225          abfd->filename,
 226          abfd->xvec->name,
 227          name);
 228   exit(1);
 229 }
 230
 231 /*ARGSUSED*/
 232 static
 233 void
 234 DEFUN(bfd_undefined_symbol,(relent, seclet),
 235       CONST  arelent *relent AND
 236       CONST  struct bfd_seclet *seclet)
 237 {
 238   asymbol *symbol = *(relent->sym_ptr_ptr);
 239   printf("bfd error relocating, symbol %s is undefined\n",
 240          symbol->name);
 241   exit(1);
 242 }
 243 /*ARGSUSED*/
 244 static
 245 void
 246 DEFUN(bfd_reloc_value_truncated,(relent, seclet),
 247          CONST  arelent *relent AND
 248       struct bfd_seclet *seclet)
 249 {
 250   printf("bfd error relocating, value truncated\n");
 251   exit(1);
 252 }
 253 /*ARGSUSED*/
 254 static
 255 void
 256 DEFUN(bfd_reloc_is_dangerous,(relent, seclet),
 257       CONST  arelent *relent AND
 258      CONST  struct bfd_seclet *seclet)
 259 {
 260   printf("bfd error relocating, dangerous\n");
 261   exit(1);
 262 }
 263
 264 bfd_error_vector_type bfd_error_vector =
 265   {
 266   bfd_nonrepresentable_section ,
 267   bfd_undefined_symbol,
 268   bfd_reloc_value_truncated,
 269   bfd_reloc_is_dangerous,
 270   };
 271
 272
 273 CONST char *
 274 bfd_errmsg (error_tag)
 275      bfd_ec error_tag;
 276 {
 277 #ifndef errno
 278   extern int errno;
 279 #endif
 280   if (error_tag == system_call_error)
 281     return strerror (errno);
 282
 283   if ((((int)error_tag <(int) no_error) ||
 284        ((int)error_tag > (int)invalid_error_code)))
 285     error_tag = invalid_error_code;/* sanity check */
 286
 287   return bfd_errmsgs [(int)error_tag];
 288 }
 289
 290
 291 void bfd_default_error_trap(error_tag)
 292 bfd_ec error_tag;
 293 {
 294   printf("bfd assert fail (%s)\n", bfd_errmsg(error_tag));
 295 }
 296
 297 void (*bfd_error_trap)() = bfd_default_error_trap;
 298 void (*bfd_error_nonrepresentabltrap)() = bfd_default_error_trap;
 299
 300 void
 301 DEFUN(bfd_perror,(message),
 302       CONST char *message)
 303 {
 304   if (bfd_error == system_call_error)
 305     perror((char *)message);            /* must be system error then... */
 306   else {
 307     if (message == NULL || *message == '\0')
 308       fprintf (stderr, "%s\n", bfd_errmsg (bfd_error));
 309     else
 310       fprintf (stderr, "%s: %s\n", message, bfd_errmsg (bfd_error));
 311   }
 312 }
 313
 314  \f
 315 /** Symbols */
 316
 317
 318 /*
 319 FUNCTION
 320         bfd_get_reloc_upper_bound
 321
 322 SYNOPSIS
 323         unsigned int bfd_get_reloc_upper_bound(bfd *abfd, asection *sect);
 324
 325 DESCRIPTION
 326         This function return the number of bytes required to store the
 327         relocation information associated with section <<sect>>
 328         attached to bfd <<abfd>>
 329
 330 */
 331
 332
 333 unsigned int
 334 DEFUN(bfd_get_reloc_upper_bound,(abfd, asect),
 335      bfd *abfd AND
 336      sec_ptr asect)
 337 {
 338   if (abfd->format != bfd_object) {
 339     bfd_error = invalid_operation;
 340     return 0;
 341   }
 342
 343   return BFD_SEND (abfd, _get_reloc_upper_bound, (abfd, asect));
 344 }
 345
 346 /*
 347 FUNCTION
 348         bfd_canonicalize_reloc
 349
 350 SYNOPSIS
 351         unsigned int bfd_canonicalize_reloc
 352                 (bfd *abfd,
 353                 asection *sec,
 354                 arelent **loc,
 355                 asymbol **syms);
 356
 357 DESCRIPTION
 358         This function calls the back end associated with the open
 359         <<abfd>> and translates the external form of the relocation
 360         information attached to <<sec>> into the internal canonical
 361         form.  The table is placed into memory at <<loc>>, which has
 362         been preallocated, usually by a call to
 363         <<bfd_get_reloc_upper_bound>>.
 364
 365         The <<syms>> table is also needed for horrible internal magic
 366         reasons.
 367
 368
 369 */
 370 unsigned int
 371 DEFUN(bfd_canonicalize_reloc,(abfd, asect, location, symbols),
 372      bfd *abfd AND
 373      sec_ptr asect AND
 374      arelent **location AND
 375      asymbol **symbols)
 376 {
 377     if (abfd->format != bfd_object) {
 378             bfd_error = invalid_operation;
 379             return 0;
 380         }
 381     return BFD_SEND (abfd, _bfd_canonicalize_reloc,
 382                      (abfd, asect, location, symbols));
 383   }
 384
 385
 386 /*
 387 FUNCTION
 388         bfd_set_file_flags
 389
 390 SYNOPSIS
 391         boolean bfd_set_file_flags(bfd *abfd, flagword flags);
 392
 393 DESCRIPTION
 394         This function attempts to set the flag word in the referenced
 395         BFD structure to the value supplied.
 396
 397         Possible errors are:
 398         o wrong_format - The target bfd was not of object format.
 399         o invalid_operation - The target bfd was open for reading.
 400         o invalid_operation -
 401         The flag word contained a bit which was not applicable to the
 402         type of file. eg, an attempt was made to set the D_PAGED bit
 403         on a bfd format which does not support demand paging
 404
 405 */
 406
 407 boolean
 408 bfd_set_file_flags (abfd, flags)
 409      bfd *abfd;
 410      flagword flags;
 411 {
 412   if (abfd->format != bfd_object) {
 413     bfd_error = wrong_format;
 414     return false;
 415   }
 416
 417   if (bfd_read_p (abfd)) {
 418     bfd_error = invalid_operation;
 419     return false;
 420   }
 421
 422   bfd_get_file_flags (abfd) = flags;
 423   if ((flags & bfd_applicable_file_flags (abfd)) != flags) {
 424     bfd_error = invalid_operation;
 425     return false;
 426   }
 427
 428 return true;
 429 }
 430
 431 /*
 432 FUNCTION
 433         bfd_set_reloc
 434
 435 SYNOPSIS
 436         void bfd_set_reloc
 437           (bfd *abfd, asection *sec, arelent **rel, unsigned int count)
 438
 439 DESCRIPTION
 440         This function sets the relocation pointer and count within a
 441         section to the supplied values.
 442
 443 */
 444 /*ARGSUSED*/
 445 void
 446 bfd_set_reloc (ignore_abfd, asect, location, count)
 447      bfd *ignore_abfd;
 448      sec_ptr asect;
 449      arelent **location;
 450      unsigned int count;
 451 {
 452   asect->orelocation  = location;
 453   asect->reloc_count = count;
 454 }
 455
 456 void
 457 bfd_assert(file, line)
 458 char *file;
 459 int line;
 460 {
 461   printf("bfd assertion fail %s:%d\n",file,line);
 462 }
 463
 464
 465 /*
 466 FUNCTION
 467         bfd_set_start_address
 468
 469 DESCRIPTION
 470         Marks the entry point of an output BFD.
 471
 472 RETURNS
 473         Returns <<true>> on success, <<false>> otherwise.
 474
 475 SYNOPSIS
 476         boolean bfd_set_start_address(bfd *, bfd_vma);
 477 */
 478
 479 boolean
 480 bfd_set_start_address(abfd, vma)
 481 bfd *abfd;
 482 bfd_vma vma;
 483 {
 484   abfd->start_address = vma;
 485   return true;
 486 }
 487
 488
 489 /*
 490 FUNCTION
 491         The bfd_get_mtime function
 492
 493 SYNOPSIS
 494         long bfd_get_mtime(bfd *);
 495
 496 DESCRIPTION
 497         Return file modification time (as read from file system, or
 498         from archive header for archive members).
 499
 500 */
 501
 502 long
 503 bfd_get_mtime (abfd)
 504      bfd *abfd;
 505 {
 506   FILE *fp;
 507   struct stat buf;
 508
 509   if (abfd->mtime_set)
 510     return abfd->mtime;
 511
 512   fp = bfd_cache_lookup (abfd);
 513   if (0 != fstat (fileno (fp), &buf))
 514     return 0;
 515
 516   abfd->mtime = buf.st_mtime;           /* Save value in case anyone wants it */
 517   return buf.st_mtime;
 518 }
 519
 520 /*
 521 FUNCTION
 522         stuff
 523
 524 DESCRIPTION
 525         stuff which should be documented
 526
 527 .#define bfd_sizeof_headers(abfd, reloc) \
 528 .     BFD_SEND (abfd, _bfd_sizeof_headers, (abfd, reloc))
 529 .
 530 .#define bfd_find_nearest_line(abfd, sec, syms, off, file, func, line) \
 531 .     BFD_SEND (abfd, _bfd_find_nearest_line,  (abfd, sec, syms, off, file, func, line))
 532 .
 533 .       {* Do these three do anything useful at all, for any back end?  *}
 534 .#define bfd_debug_info_start(abfd) \
 535 .        BFD_SEND (abfd, _bfd_debug_info_start, (abfd))
 536 .
 537 .#define bfd_debug_info_end(abfd) \
 538 .        BFD_SEND (abfd, _bfd_debug_info_end, (abfd))
 539 .
 540 .#define bfd_debug_info_accumulate(abfd, section) \
 541 .        BFD_SEND (abfd, _bfd_debug_info_accumulate, (abfd, section))
 542 .
 543 .
 544 .#define bfd_stat_arch_elt(abfd, stat) \
 545 .        BFD_SEND (abfd, _bfd_stat_arch_elt,(abfd, stat))
 546 .
 547 .#define bfd_set_arch_mach(abfd, arch, mach)\
 548 .        BFD_SEND ( abfd, _bfd_set_arch_mach, (abfd, arch, mach))
 549 .
 550 .#define bfd_get_relocated_section_contents(abfd, seclet, data) \
 551 .       BFD_SEND (abfd, _bfd_get_relocated_section_contents, (abfd, seclet, data))
 552 .
 553 .#define bfd_relax_section(abfd, section, symbols) \
 554 .       BFD_SEND (abfd, _bfd_relax_section, (abfd, section, symbols))
 555
 556 */
 557
 558
 559
 560
 561
 562