bfd/libbfd.c

   1 /* Assorted BFD support routines, only used internally.
   2    Copyright 1990, 1991, 1992 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 #include "bfd.h"
  22 #include "sysdep.h"
  23 #include "libbfd.h"
  24
  25 /*
  26 SECTION
  27         libbfd
  28
  29 DESCRIPTION
  30         This file contains various routines which are used within BFD.
  31         They are not intended for export, but are documented here for
  32         completeness.
  33 */
  34
  35 boolean
  36 DEFUN(_bfd_dummy_new_section_hook,(ignore, ignore_newsect),
  37       bfd *ignore AND
  38       asection *ignore_newsect)
  39 {
  40   return true;
  41 }
  42
  43 boolean
  44 DEFUN(bfd_false ,(ignore),
  45       bfd *ignore)
  46 {
  47   return false;
  48 }
  49
  50 boolean
  51 DEFUN(bfd_true,(ignore),
  52       bfd *ignore)
  53 {
  54   return true;
  55 }
  56
  57 PTR
  58 DEFUN(bfd_nullvoidptr,(ignore),
  59       bfd *ignore)
  60 {
  61   return (PTR)NULL;
  62 }
  63
  64 int
  65 DEFUN(bfd_0,(ignore),
  66       bfd *ignore)
  67 {
  68   return 0;
  69 }
  70
  71 unsigned int
  72 DEFUN(bfd_0u,(ignore),
  73       bfd *ignore)
  74 {
  75    return 0;
  76 }
  77
  78 void
  79 DEFUN(bfd_void,(ignore),
  80       bfd *ignore)
  81 {
  82 }
  83
  84 boolean
  85 DEFUN(_bfd_dummy_core_file_matches_executable_p,(ignore_core_bfd, ignore_exec_bfd),
  86       bfd *ignore_core_bfd AND
  87       bfd *ignore_exec_bfd)
  88 {
  89   bfd_error = invalid_operation;
  90   return false;
  91 }
  92
  93 /* of course you can't initialize a function to be the same as another, grr */
  94
  95 char *
  96 DEFUN(_bfd_dummy_core_file_failing_command,(ignore_abfd),
  97       bfd *ignore_abfd)
  98 {
  99   return (char *)NULL;
 100 }
 101
 102 int
 103 DEFUN(_bfd_dummy_core_file_failing_signal,(ignore_abfd),
 104      bfd *ignore_abfd)
 105 {
 106   return 0;
 107 }
 108
 109 bfd_target *
 110 DEFUN(_bfd_dummy_target,(ignore_abfd),
 111      bfd *ignore_abfd)
 112 {
 113   return 0;
 114 }
 115 \f
 116 /** zalloc -- allocate and clear storage */
 117
 118
 119 #ifndef zalloc
 120 char *
 121 DEFUN(zalloc,(size),
 122       bfd_size_type size)
 123 {
 124   char *ptr = (char *) malloc ((int)size);
 125
 126   if ((ptr != NULL) && (size != 0))
 127    memset(ptr,0, size);
 128
 129   return ptr;
 130 }
 131 #endif
 132
 133 /*
 134 INTERNAL_FUNCTION
 135         bfd_xmalloc
 136
 137 SYNOPSIS
 138         PTR  bfd_xmalloc( bfd_size_type size);
 139
 140 DESCRIPTION
 141         Like malloc, but exit if no more memory.
 142
 143 */
 144
 145 /** There is major inconsistency in how running out of memory is handled.
 146   Some routines return a NULL, and set bfd_error to no_memory.
 147   However, obstack routines can't do this ... */
 148
 149
 150 DEFUN(PTR bfd_xmalloc,(size),
 151       bfd_size_type size)
 152 {
 153   static CONST char no_memory_message[] = "Virtual memory exhausted!\n";
 154   PTR ptr;
 155   if (size == 0) size = 1;
 156   ptr = (PTR)malloc(size);
 157   if (!ptr)
 158     {
 159       write (2, no_memory_message, sizeof(no_memory_message)-1);
 160       exit (-1);
 161     }
 162   return ptr;
 163 }
 164 \f
 165 /* Some IO code */
 166
 167
 168 /* Note that archive entries don't have streams; they share their parent's.
 169    This allows someone to play with the iostream behind BFD's back.
 170
 171    Also, note that the origin pointer points to the beginning of a file's
 172    contents (0 for non-archive elements).  For archive entries this is the
 173    first octet in the file, NOT the beginning of the archive header. */
 174
 175 static
 176 int DEFUN(real_read,(where, a,b, file),
 177           PTR where AND
 178           int a AND
 179           int b AND
 180           FILE *file)
 181 {
 182   return fread(where, a,b,file);
 183 }
 184 bfd_size_type
 185 DEFUN(bfd_read,(ptr, size, nitems, abfd),
 186       PTR ptr AND
 187       bfd_size_type size AND
 188       bfd_size_type nitems AND
 189       bfd *abfd)
 190 {
 191   int nread;
 192   nread = real_read (ptr, 1, (int)(size*nitems), bfd_cache_lookup(abfd));
 193 #ifdef FILE_OFFSET_IS_CHAR_INDEX
 194   if (nread > 0)
 195     abfd->where += nread;
 196 #endif
 197   return nread;
 198 }
 199
 200 bfd_size_type
 201 DEFUN(bfd_write,(ptr, size, nitems, abfd),
 202       CONST PTR ptr AND
 203       bfd_size_type size AND
 204       bfd_size_type nitems AND
 205       bfd *abfd)
 206 {
 207   int nwrote = fwrite (ptr, 1, (int)(size*nitems), bfd_cache_lookup(abfd));
 208 #ifdef FILE_OFFSET_IS_CHAR_INDEX
 209   if (nwrote > 0)
 210     abfd->where += nwrote;
 211 #endif
 212   return nwrote;
 213 }
 214
 215 /*
 216 INTERNAL_FUNCTION
 217         bfd_write_bigendian_4byte_int
 218
 219 SYNOPSIS
 220         void bfd_write_bigendian_4byte_int(bfd *abfd,  int i);
 221
 222 DESCRIPTION
 223         Writes a 4 byte integer to the outputing bfd, in big endian
 224         mode regardless of what else is going on.  This is usefull in
 225         archives.
 226
 227 */
 228 void
 229 DEFUN(bfd_write_bigendian_4byte_int,(abfd, i),
 230       bfd *abfd AND
 231       int i)
 232 {
 233   bfd_byte buffer[4];
 234   _do_putb32(i, buffer);
 235   bfd_write((PTR)buffer, 4, 1, abfd);
 236 }
 237
 238 long
 239 DEFUN(bfd_tell,(abfd),
 240       bfd *abfd)
 241 {
 242   file_ptr ptr;
 243
 244   ptr = ftell (bfd_cache_lookup(abfd));
 245
 246   if (abfd->my_archive)
 247     ptr -= abfd->origin;
 248   abfd->where = ptr;
 249   return ptr;
 250 }
 251
 252 int
 253 DEFUN(bfd_seek,(abfd, position, direction),
 254       bfd * CONST abfd AND
 255       CONST file_ptr position AND
 256       CONST int direction)
 257 {
 258   int result;
 259   FILE *f;
 260   file_ptr file_position;
 261   /* For the time being, a BFD may not seek to it's end.  The problem
 262      is that we don't easily have a way to recognize the end of an
 263      element in an archive. */
 264
 265   BFD_ASSERT (direction == SEEK_SET || direction == SEEK_CUR);
 266
 267   if (direction == SEEK_CUR && position == 0)
 268     return 0;
 269 #ifdef FILE_OFFSET_IS_CHAR_INDEX
 270   if (abfd->format != bfd_archive && abfd->my_archive == 0)
 271     {
 272 #ifndef NDEBUG
 273       /* Explanation for this code: I'm only about 95+% sure that the above
 274          conditions are sufficient and that all i/o calls are properly
 275          adjusting the `where' field.  So this is sort of an `assert'
 276          that the `where' field is correct.  If we can go a while without
 277          tripping the abort, we can probably safely disable this code,
 278          so that the real optimizations happen.  */
 279       file_ptr where_am_i_now;
 280       where_am_i_now = ftell (bfd_cache_lookup (abfd));
 281       if (abfd->my_archive)
 282         where_am_i_now -= abfd->origin;
 283       if (where_am_i_now != abfd->where)
 284         abort ();
 285 #endif
 286       if (direction == SEEK_SET && position == abfd->where)
 287         return 0;
 288     }
 289   else
 290     {
 291       /* We need something smarter to optimize access to archives.
 292          Currently, anything inside an archive is read via the file
 293          handle for the archive.  Which means that a bfd_seek on one
 294          component affects the `current position' in the archive, as
 295          well as in any other component.
 296
 297          It might be sufficient to put a spike through the cache
 298          abstraction, and look to the archive for the file position,
 299          but I think we should try for something cleaner.
 300
 301          In the meantime, no optimization for archives.  */
 302     }
 303 #endif
 304
 305   f = bfd_cache_lookup (abfd);
 306   file_position = position;
 307   if (direction == SEEK_SET && abfd->my_archive != NULL)
 308     file_position += abfd->origin;
 309
 310   result = fseek (f, file_position, direction);
 311
 312   if (result != 0)
 313     /* Force redetermination of `where' field.  */
 314     bfd_tell (abfd);
 315   else
 316     {
 317 #ifdef FILE_OFFSET_IS_CHAR_INDEX
 318       /* Adjust `where' field.  */
 319       if (direction == SEEK_SET)
 320         abfd->where = position;
 321       else
 322         abfd->where += position;
 323 #endif
 324     }
 325   return result;
 326 }
 327 \f
 328 /** Make a string table */
 329
 330 /*>bfd.h<
 331  Add string to table pointed to by table, at location starting with free_ptr.
 332    resizes the table if necessary (if it's NULL, creates it, ignoring
 333    table_length).  Updates free_ptr, table, table_length */
 334
 335 boolean
 336 DEFUN(bfd_add_to_string_table,(table, new_string, table_length, free_ptr),
 337       char **table AND
 338       char *new_string AND
 339       unsigned int *table_length AND
 340       char **free_ptr)
 341 {
 342   size_t string_length = strlen (new_string) + 1; /* include null here */
 343   char *base = *table;
 344   size_t space_length = *table_length;
 345   unsigned int offset = (base ? *free_ptr - base : 0);
 346
 347   if (base == NULL) {
 348     /* Avoid a useless regrow if we can (but of course we still
 349        take it next time */
 350     space_length = (string_length < DEFAULT_STRING_SPACE_SIZE ?
 351                     DEFAULT_STRING_SPACE_SIZE : string_length+1);
 352     base = zalloc (space_length);
 353
 354     if (base == NULL) {
 355       bfd_error = no_memory;
 356       return false;
 357     }
 358   }
 359
 360   if ((size_t)(offset + string_length) >= space_length) {
 361     /* Make sure we will have enough space */
 362     while ((size_t)(offset + string_length) >= space_length)
 363       space_length += space_length/2; /* grow by 50% */
 364
 365     base = (char *) realloc (base, space_length);
 366     if (base == NULL) {
 367       bfd_error = no_memory;
 368       return false;
 369     }
 370
 371   }
 372
 373   memcpy (base + offset, new_string, string_length);
 374   *table = base;
 375   *table_length = space_length;
 376   *free_ptr = base + offset + string_length;
 377
 378   return true;
 379 }
 380 \f
 381 /** The do-it-yourself (byte) sex-change kit */
 382
 383 /* The middle letter e.g. get<b>short indicates Big or Little endian
 384    target machine.  It doesn't matter what the byte order of the host
 385    machine is; these routines work for either.  */
 386
 387 /* FIXME: Should these take a count argument?
 388    Answer (gnu@cygnus.com):  No, but perhaps they should be inline
 389                              functions in swap.h #ifdef __GNUC__.
 390                              Gprof them later and find out.  */
 391
 392 /*
 393 FUNCTION
 394         bfd_put_size
 395 FUNCTION
 396         bfd_get_size
 397
 398 DESCRIPTION
 399         These macros as used for reading and writing raw data in
 400         sections; each access (except for bytes) is vectored through
 401         the target format of the BFD and mangled accordingly. The
 402         mangling performs any necessary endian translations and
 403         removes alignment restrictions.
 404
 405 .#define bfd_put_8(abfd, val, ptr) \
 406 .                (*((char *)ptr) = (char)val)
 407 .#define bfd_get_8(abfd, ptr) \
 408 .                (*((char *)ptr))
 409 .#define bfd_put_16(abfd, val, ptr) \
 410 .                BFD_SEND(abfd, bfd_putx16, (val,ptr))
 411 .#define bfd_get_16(abfd, ptr) \
 412 .                BFD_SEND(abfd, bfd_getx16, (ptr))
 413 .#define bfd_put_32(abfd, val, ptr) \
 414 .                BFD_SEND(abfd, bfd_putx32, (val,ptr))
 415 .#define bfd_get_32(abfd, ptr) \
 416 .                BFD_SEND(abfd, bfd_getx32, (ptr))
 417 .#define bfd_put_64(abfd, val, ptr) \
 418 .                BFD_SEND(abfd, bfd_putx64, (val, ptr))
 419 .#define bfd_get_64(abfd, ptr) \
 420 .                BFD_SEND(abfd, bfd_getx64, (ptr))
 421
 422 */
 423
 424 /*
 425 FUNCTION
 426         bfd_h_put_size
 427 FUNCTION
 428         bfd_h_get_size
 429
 430 DESCRIPTION
 431         These macros have the same function as their <<bfd_get_x>>
 432         bretherin, except that they are used for removing information
 433         for the header records of object files. Believe it or not,
 434         some object files keep their header records in big endian
 435         order, and their data in little endan order.
 436
 437 .#define bfd_h_put_8(abfd, val, ptr) \
 438 .                (*((char *)ptr) = (char)val)
 439 .#define bfd_h_get_8(abfd, ptr) \
 440 .                (*((char *)ptr))
 441 .#define bfd_h_put_16(abfd, val, ptr) \
 442 .                BFD_SEND(abfd, bfd_h_putx16,(val,ptr))
 443 .#define bfd_h_get_16(abfd, ptr) \
 444 .                BFD_SEND(abfd, bfd_h_getx16,(ptr))
 445 .#define bfd_h_put_32(abfd, val, ptr) \
 446 .                BFD_SEND(abfd, bfd_h_putx32,(val,ptr))
 447 .#define bfd_h_get_32(abfd, ptr) \
 448 .                BFD_SEND(abfd, bfd_h_getx32,(ptr))
 449 .#define bfd_h_put_64(abfd, val, ptr) \
 450 .                BFD_SEND(abfd, bfd_h_putx64,(val, ptr))
 451 .#define bfd_h_get_64(abfd, ptr) \
 452 .                BFD_SEND(abfd, bfd_h_getx64,(ptr))
 453
 454 */
 455
 456 bfd_vma
 457 DEFUN(_do_getb16,(addr),
 458       register bfd_byte *addr)
 459 {
 460         return (addr[0] << 8) | addr[1];
 461 }
 462
 463 bfd_vma
 464 DEFUN(_do_getl16,(addr),
 465       register bfd_byte *addr)
 466 {
 467         return (addr[1] << 8) | addr[0];
 468 }
 469
 470 void
 471 DEFUN(_do_putb16,(data, addr),
 472       bfd_vma data AND
 473       register bfd_byte *addr)
 474 {
 475         addr[0] = (bfd_byte)(data >> 8);
 476         addr[1] = (bfd_byte )data;
 477 }
 478
 479 void
 480 DEFUN(_do_putl16,(data, addr),
 481       bfd_vma data AND
 482       register bfd_byte *addr)
 483 {
 484         addr[0] = (bfd_byte )data;
 485         addr[1] = (bfd_byte)(data >> 8);
 486 }
 487
 488 bfd_vma
 489 DEFUN(_do_getb32,(addr),
 490       register bfd_byte *addr)
 491 {
 492         return ((((addr[0] << 8) | addr[1]) << 8) | addr[2]) << 8 | addr[3];
 493 }
 494
 495 bfd_vma
 496 _do_getl32 (addr)
 497         register bfd_byte *addr;
 498 {
 499         return ((((addr[3] << 8) | addr[2]) << 8) | addr[1]) << 8 | addr[0];
 500 }
 501
 502 bfd_vma
 503 DEFUN(_do_getb64,(addr),
 504       register bfd_byte *addr)
 505 {
 506 #ifdef HOST_64_BIT
 507   bfd_vma low, high;
 508
 509   high= ((((((((addr[0]) << 8) |
 510               addr[1]) << 8) |
 511             addr[2]) << 8) |
 512           addr[3]) );
 513
 514   low = ((((((((addr[4]) << 8) |
 515               addr[5]) << 8) |
 516             addr[6]) << 8) |
 517           addr[7]));
 518
 519   return high << 32 | low;
 520 #else
 521   BFD_FAIL();
 522   return 0;
 523 #endif
 524
 525 }
 526
 527 bfd_vma
 528 DEFUN(_do_getl64,(addr),
 529       register bfd_byte *addr)
 530 {
 531
 532 #ifdef HOST_64_BIT
 533   bfd_vma low, high;
 534   high= (((((((addr[7] << 8) |
 535               addr[6]) << 8) |
 536             addr[5]) << 8) |
 537           addr[4]));
 538
 539   low = (((((((addr[3] << 8) |
 540               addr[2]) << 8) |
 541             addr[1]) << 8) |
 542           addr[0]) );
 543
 544   return high << 32 | low;
 545 #else
 546   BFD_FAIL();
 547   return 0;
 548 #endif
 549
 550 }
 551
 552 void
 553 DEFUN(_do_putb32,(data, addr),
 554       bfd_vma data AND
 555       register bfd_byte *addr)
 556 {
 557         addr[0] = (bfd_byte)(data >> 24);
 558         addr[1] = (bfd_byte)(data >> 16);
 559         addr[2] = (bfd_byte)(data >>  8);
 560         addr[3] = (bfd_byte)data;
 561 }
 562
 563 void
 564 DEFUN(_do_putl32,(data, addr),
 565       bfd_vma data AND
 566       register bfd_byte *addr)
 567 {
 568         addr[0] = (bfd_byte)data;
 569         addr[1] = (bfd_byte)(data >>  8);
 570         addr[2] = (bfd_byte)(data >> 16);
 571         addr[3] = (bfd_byte)(data >> 24);
 572 }
 573 void
 574 DEFUN(_do_putb64,(data, addr),
 575         bfd_vma data AND
 576         register bfd_byte *addr)
 577 {
 578 #ifdef HOST_64_BIT
 579   addr[0] = (bfd_byte)(data >> (7*8));
 580   addr[1] = (bfd_byte)(data >> (6*8));
 581   addr[2] = (bfd_byte)(data >> (5*8));
 582   addr[3] = (bfd_byte)(data >> (4*8));
 583   addr[4] = (bfd_byte)(data >> (3*8));
 584   addr[5] = (bfd_byte)(data >> (2*8));
 585   addr[6] = (bfd_byte)(data >> (1*8));
 586   addr[7] = (bfd_byte)(data >> (0*8));
 587 #else
 588   BFD_FAIL();
 589 #endif
 590
 591 }
 592
 593 void
 594 DEFUN(_do_putl64,(data, addr),
 595       bfd_vma data AND
 596       register bfd_byte *addr)
 597 {
 598 #ifdef HOST_64_BIT
 599   addr[7] = (bfd_byte)(data >> (7*8));
 600   addr[6] = (bfd_byte)(data >> (6*8));
 601   addr[5] = (bfd_byte)(data >> (5*8));
 602   addr[4] = (bfd_byte)(data >> (4*8));
 603   addr[3] = (bfd_byte)(data >> (3*8));
 604   addr[2] = (bfd_byte)(data >> (2*8));
 605   addr[1] = (bfd_byte)(data >> (1*8));
 606   addr[0] = (bfd_byte)(data >> (0*8));
 607 #else
 608   BFD_FAIL();
 609 #endif
 610
 611 }
 612
 613 \f
 614 /* Default implementation */
 615
 616 boolean
 617 DEFUN(bfd_generic_get_section_contents, (abfd, section, location, offset, count),
 618       bfd *abfd AND
 619       sec_ptr section AND
 620       PTR location AND
 621       file_ptr offset AND
 622       bfd_size_type count)
 623 {
 624     if (count == 0)
 625         return true;
 626     if ((bfd_size_type)(offset+count) > section->_raw_size
 627         || bfd_seek(abfd, (file_ptr)(section->filepos + offset), SEEK_SET) == -1
 628         || bfd_read(location, (bfd_size_type)1, count, abfd) != count)
 629         return (false); /* on error */
 630     return (true);
 631 }
 632
 633 /* This generic function can only be used in implementations where creating
 634    NEW sections is disallowed.  It is useful in patching existing sections
 635    in read-write files, though.  See other set_section_contents functions
 636    to see why it doesn't work for new sections.  */
 637 boolean
 638 DEFUN(bfd_generic_set_section_contents, (abfd, section, location, offset, count),
 639       bfd *abfd AND
 640       sec_ptr section AND
 641       PTR location AND
 642       file_ptr offset AND
 643       bfd_size_type count)
 644 {
 645     if (count == 0)
 646         return true;
 647     if ((bfd_size_type)(offset+count) > bfd_get_section_size_after_reloc(section)
 648         || bfd_seek(abfd, (file_ptr)(section->filepos + offset), SEEK_SET) == -1
 649         || bfd_write(location, (bfd_size_type)1, count, abfd) != count)
 650         return (false); /* on error */
 651     return (true);
 652 }
 653
 654 /*
 655 INTERNAL_FUNCTION
 656         bfd_log2
 657
 658 DESCRIPTION
 659         Return the log base 2 of the value supplied, rounded up. eg an
 660         arg of 1025 would return 11.
 661
 662 SYNOPSIS
 663         bfd_vma bfd_log2(bfd_vma x);
 664 */
 665
 666 bfd_vma bfd_log2(x)
 667 bfd_vma x;
 668 {
 669   bfd_vma  result = 0;
 670   while ( (bfd_vma)(1<< result) < x)
 671     result++;
 672   return result;
 673 }