bfd/libbfd.c

   1 /* Assorted BFD support routines, only used internally.
   2    Copyright 1990, 91, 92, 93, 94, 95, 96, 97, 98, 1999
   3    Free Software Foundation, Inc.
   4    Written by Cygnus Support.
   5
   6 This file is part of BFD, the Binary File Descriptor library.
   7
   8 This program is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2 of the License, or
  11 (at your option) any later version.
  12
  13 This program is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with this program; if not, write to the Free Software
  20 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  21
  22 #include "bfd.h"
  23 #include "sysdep.h"
  24 #include "libbfd.h"
  25
  26 #ifndef HAVE_GETPAGESIZE
  27 #define getpagesize() 2048
  28 #endif
  29
  30 static int real_read PARAMS ((PTR, size_t, size_t, FILE *));
  31
  32 /*
  33 SECTION
  34         Internal functions
  35
  36 DESCRIPTION
  37         These routines are used within BFD.
  38         They are not intended for export, but are documented here for
  39         completeness.
  40 */
  41
  42 /* A routine which is used in target vectors for unsupported
  43    operations.  */
  44
  45 /*ARGSUSED*/
  46 boolean
  47 bfd_false (ignore)
  48      bfd *ignore ATTRIBUTE_UNUSED;
  49 {
  50   bfd_set_error (bfd_error_invalid_operation);
  51   return false;
  52 }
  53
  54 /* A routine which is used in target vectors for supported operations
  55    which do not actually do anything.  */
  56
  57 /*ARGSUSED*/
  58 boolean
  59 bfd_true (ignore)
  60      bfd *ignore ATTRIBUTE_UNUSED;
  61 {
  62   return true;
  63 }
  64
  65 /* A routine which is used in target vectors for unsupported
  66    operations which return a pointer value.  */
  67
  68 /*ARGSUSED*/
  69 PTR
  70 bfd_nullvoidptr (ignore)
  71      bfd *ignore ATTRIBUTE_UNUSED;
  72 {
  73   bfd_set_error (bfd_error_invalid_operation);
  74   return NULL;
  75 }
  76
  77 /*ARGSUSED*/
  78 int
  79 bfd_0 (ignore)
  80      bfd *ignore ATTRIBUTE_UNUSED;
  81 {
  82   return 0;
  83 }
  84
  85 /*ARGSUSED*/
  86 unsigned int
  87 bfd_0u (ignore)
  88      bfd *ignore ATTRIBUTE_UNUSED;
  89 {
  90    return 0;
  91 }
  92
  93 /*ARGUSED*/
  94 long
  95 bfd_0l (ignore)
  96      bfd *ignore ATTRIBUTE_UNUSED;
  97 {
  98   return 0;
  99 }
 100
 101 /* A routine which is used in target vectors for unsupported
 102    operations which return -1 on error.  */
 103
 104 /*ARGSUSED*/
 105 long
 106 _bfd_n1 (ignore_abfd)
 107      bfd *ignore_abfd ATTRIBUTE_UNUSED;
 108 {
 109   bfd_set_error (bfd_error_invalid_operation);
 110   return -1;
 111 }
 112
 113 /*ARGSUSED*/
 114 void
 115 bfd_void (ignore)
 116      bfd *ignore ATTRIBUTE_UNUSED;
 117 {
 118 }
 119
 120 /*ARGSUSED*/
 121 boolean
 122 _bfd_nocore_core_file_matches_executable_p (ignore_core_bfd, ignore_exec_bfd)
 123      bfd *ignore_core_bfd ATTRIBUTE_UNUSED;
 124      bfd *ignore_exec_bfd ATTRIBUTE_UNUSED;
 125 {
 126   bfd_set_error (bfd_error_invalid_operation);
 127   return false;
 128 }
 129
 130 /* Routine to handle core_file_failing_command entry point for targets
 131    without core file support.  */
 132
 133 /*ARGSUSED*/
 134 char *
 135 _bfd_nocore_core_file_failing_command (ignore_abfd)
 136      bfd *ignore_abfd ATTRIBUTE_UNUSED;
 137 {
 138   bfd_set_error (bfd_error_invalid_operation);
 139   return (char *)NULL;
 140 }
 141
 142 /* Routine to handle core_file_failing_signal entry point for targets
 143    without core file support.  */
 144
 145 /*ARGSUSED*/
 146 int
 147 _bfd_nocore_core_file_failing_signal (ignore_abfd)
 148      bfd *ignore_abfd ATTRIBUTE_UNUSED;
 149 {
 150   bfd_set_error (bfd_error_invalid_operation);
 151   return 0;
 152 }
 153
 154 /*ARGSUSED*/
 155 const bfd_target *
 156 _bfd_dummy_target (ignore_abfd)
 157      bfd *ignore_abfd ATTRIBUTE_UNUSED;
 158 {
 159   bfd_set_error (bfd_error_wrong_format);
 160   return 0;
 161 }
 162 \f
 163 /* Allocate memory using malloc.  */
 164
 165 PTR
 166 bfd_malloc (size)
 167      size_t size;
 168 {
 169   PTR ptr;
 170
 171   ptr = (PTR) malloc (size);
 172   if (ptr == NULL && size != 0)
 173     bfd_set_error (bfd_error_no_memory);
 174   return ptr;
 175 }
 176
 177 /* Reallocate memory using realloc.  */
 178
 179 PTR
 180 bfd_realloc (ptr, size)
 181      PTR ptr;
 182      size_t size;
 183 {
 184   PTR ret;
 185
 186   if (ptr == NULL)
 187     ret = malloc (size);
 188   else
 189     ret = realloc (ptr, size);
 190
 191   if (ret == NULL)
 192     bfd_set_error (bfd_error_no_memory);
 193
 194   return ret;
 195 }
 196
 197 /* Allocate memory using malloc and clear it.  */
 198
 199 PTR
 200 bfd_zmalloc (size)
 201      size_t size;
 202 {
 203   PTR ptr;
 204
 205   ptr = (PTR) malloc (size);
 206
 207   if (size != 0)
 208     {
 209       if (ptr == NULL)
 210         bfd_set_error (bfd_error_no_memory);
 211       else
 212         memset (ptr, 0, size);
 213     }
 214
 215   return ptr;
 216 }
 217 \f
 218 /* Some IO code */
 219
 220
 221 /* Note that archive entries don't have streams; they share their parent's.
 222    This allows someone to play with the iostream behind BFD's back.
 223
 224    Also, note that the origin pointer points to the beginning of a file's
 225    contents (0 for non-archive elements).  For archive entries this is the
 226    first octet in the file, NOT the beginning of the archive header. */
 227
 228 static int
 229 real_read (where, a,b, file)
 230      PTR where;
 231      size_t a;
 232      size_t b;
 233      FILE *file;
 234 {
 235   /* FIXME - this looks like an optimization, but it's really to cover
 236      up for a feature of some OSs (not solaris - sigh) that
 237      ld/pe-dll.c takes advantage of (apparently) when it creates BFDs
 238      internally and tries to link against them.  BFD seems to be smart
 239      enough to realize there are no symbol records in the "file" that
 240      doesn't exist but attempts to read them anyway.  On Solaris,
 241      attempting to read zero bytes from a NULL file results in a core
 242      dump, but on other platforms it just returns zero bytes read.
 243      This makes it to something reasonable. - DJ */
 244   if (a == 0 || b == 0)
 245     return 0;
 246
 247 #if defined (__VAX) && defined (VMS)
 248   /* Apparently fread on Vax VMS does not keep the record length
 249      information.  */
 250   return read (fileno (file), where, a * b);
 251 #else
 252   return fread (where, a, b, file);
 253 #endif
 254 }
 255
 256 /* Return value is amount read (FIXME: how are errors and end of file dealt
 257    with?  We never call bfd_set_error, which is probably a mistake).  */
 258
 259 bfd_size_type
 260 bfd_read (ptr, size, nitems, abfd)
 261      PTR ptr;
 262      bfd_size_type size;
 263      bfd_size_type nitems;
 264      bfd *abfd;
 265 {
 266   int nread;
 267
 268   if ((abfd->flags & BFD_IN_MEMORY) != 0)
 269     {
 270       struct bfd_in_memory *bim;
 271       bfd_size_type get;
 272
 273       bim = (struct bfd_in_memory *) abfd->iostream;
 274       get = size * nitems;
 275       if (abfd->where + get > bim->size)
 276         {
 277           if (bim->size < (bfd_size_type) abfd->where)
 278             get = 0;
 279           else
 280             get = bim->size - abfd->where;
 281           bfd_set_error (bfd_error_file_truncated);
 282         }
 283       memcpy (ptr, bim->buffer + abfd->where, get);
 284       abfd->where += get;
 285       return get;
 286     }
 287
 288   nread = real_read (ptr, 1, (size_t)(size*nitems), bfd_cache_lookup(abfd));
 289   if (nread > 0)
 290     abfd->where += nread;
 291
 292   /* Set bfd_error if we did not read as much data as we expected.
 293
 294      If the read failed due to an error set the bfd_error_system_call,
 295      else set bfd_error_file_truncated.
 296
 297      A BFD backend may wish to override bfd_error_file_truncated to
 298      provide something more useful (eg. no_symbols or wrong_format).  */
 299   if (nread != (int) (size * nitems))
 300     {
 301       if (ferror (bfd_cache_lookup (abfd)))
 302         bfd_set_error (bfd_error_system_call);
 303       else
 304         bfd_set_error (bfd_error_file_truncated);
 305     }
 306
 307   return nread;
 308 }
 309
 310 /* The window support stuff should probably be broken out into
 311    another file....  */
 312 /* The idea behind the next and refcount fields is that one mapped
 313    region can suffice for multiple read-only windows or multiple
 314    non-overlapping read-write windows.  It's not implemented yet
 315    though.  */
 316 struct _bfd_window_internal {
 317   struct _bfd_window_internal *next;
 318   PTR data;
 319   bfd_size_type size;
 320   int refcount : 31;            /* should be enough... */
 321   unsigned mapped : 1;          /* 1 = mmap, 0 = malloc */
 322 };
 323
 324 void
 325 bfd_init_window (windowp)
 326      bfd_window *windowp;
 327 {
 328   windowp->data = 0;
 329   windowp->i = 0;
 330   windowp->size = 0;
 331 }
 332 \f
 333 /* Currently, if USE_MMAP is undefined, none if the window stuff is
 334    used.  Okay, so it's mis-named.  At least the command-line option
 335    "--without-mmap" is more obvious than "--without-windows" or some
 336    such.  */
 337 #ifdef USE_MMAP
 338
 339 #undef HAVE_MPROTECT /* code's not tested yet */
 340
 341 #if HAVE_MMAP || HAVE_MPROTECT || HAVE_MADVISE
 342 #include <sys/mman.h>
 343 #endif
 344
 345 #ifndef MAP_FILE
 346 #define MAP_FILE 0
 347 #endif
 348
 349 static int debug_windows;
 350
 351 void
 352 bfd_free_window (windowp)
 353      bfd_window *windowp;
 354 {
 355   bfd_window_internal *i = windowp->i;
 356   windowp->i = 0;
 357   windowp->data = 0;
 358   if (i == 0)
 359     return;
 360   i->refcount--;
 361   if (debug_windows)
 362     fprintf (stderr, "freeing window @%p<%p,%lx,%p>\n",
 363              windowp, windowp->data, windowp->size, windowp->i);
 364   if (i->refcount != 0)
 365     return;
 366
 367   if (i->mapped)
 368     {
 369 #ifdef HAVE_MMAP
 370       munmap (i->data, i->size);
 371       goto no_free;
 372 #else
 373       abort ();
 374 #endif
 375     }
 376 #ifdef HAVE_MPROTECT
 377   mprotect (i->data, i->size, PROT_READ | PROT_WRITE);
 378 #endif
 379   free (i->data);
 380 #ifdef HAVE_MMAP
 381  no_free:
 382 #endif
 383   i->data = 0;
 384   /* There should be no more references to i at this point.  */
 385   free (i);
 386 }
 387
 388 static int ok_to_map = 1;
 389
 390 boolean
 391 bfd_get_file_window (abfd, offset, size, windowp, writable)
 392      bfd *abfd;
 393      file_ptr offset;
 394      bfd_size_type size;
 395      bfd_window *windowp;
 396      boolean writable;
 397 {
 398   static size_t pagesize;
 399   bfd_window_internal *i = windowp->i;
 400   size_t size_to_alloc = size;
 401
 402   if (debug_windows)
 403     fprintf (stderr, "bfd_get_file_window (%p, %6ld, %6ld, %p<%p,%lx,%p>, %d)",
 404              abfd, (long) offset, (long) size,
 405              windowp, windowp->data, (unsigned long) windowp->size,
 406              windowp->i, writable);
 407
 408   /* Make sure we know the page size, so we can be friendly to mmap.  */
 409   if (pagesize == 0)
 410     pagesize = getpagesize ();
 411   if (pagesize == 0)
 412     abort ();
 413
 414   if (i == 0)
 415     {
 416       windowp->i = i = (bfd_window_internal *) bfd_zmalloc (sizeof (bfd_window_internal));
 417       if (i == 0)
 418         return false;
 419       i->data = 0;
 420     }
 421 #ifdef HAVE_MMAP
 422   if (ok_to_map
 423       && (i->data == 0 || i->mapped == 1)
 424       && (abfd->flags & BFD_IN_MEMORY) == 0)
 425     {
 426       file_ptr file_offset, offset2;
 427       size_t real_size;
 428       int fd;
 429       FILE *f;
 430
 431       /* Find the real file and the real offset into it.  */
 432       while (abfd->my_archive != NULL)
 433         {
 434           offset += abfd->origin;
 435           abfd = abfd->my_archive;
 436         }
 437       f = bfd_cache_lookup (abfd);
 438       fd = fileno (f);
 439
 440       /* Compute offsets and size for mmap and for the user's data.  */
 441       offset2 = offset % pagesize;
 442       if (offset2 < 0)
 443         abort ();
 444       file_offset = offset - offset2;
 445       real_size = offset + size - file_offset;
 446       real_size = real_size + pagesize - 1;
 447       real_size -= real_size % pagesize;
 448
 449       /* If we're re-using a memory region, make sure it's big enough.  */
 450       if (i->data && i->size < size)
 451         {
 452           munmap (i->data, i->size);
 453           i->data = 0;
 454         }
 455       i->data = mmap (i->data, real_size,
 456                       writable ? PROT_WRITE | PROT_READ : PROT_READ,
 457                       (writable
 458                        ? MAP_FILE | MAP_PRIVATE
 459                        : MAP_FILE | MAP_SHARED),
 460                       fd, file_offset);
 461       if (i->data == (PTR) -1)
 462         {
 463           /* An error happened.  Report it, or try using malloc, or
 464              something.  */
 465           bfd_set_error (bfd_error_system_call);
 466           i->data = 0;
 467           windowp->data = 0;
 468           if (debug_windows)
 469             fprintf (stderr, "\t\tmmap failed!\n");
 470           return false;
 471         }
 472       if (debug_windows)
 473         fprintf (stderr, "\n\tmapped %ld at %p, offset is %ld\n",
 474                  (long) real_size, i->data, (long) offset2);
 475       i->size = real_size;
 476       windowp->data = (PTR) ((bfd_byte *) i->data + offset2);
 477       windowp->size = size;
 478       i->mapped = 1;
 479       return true;
 480     }
 481   else if (debug_windows)
 482     {
 483       if (ok_to_map)
 484         fprintf (stderr, _("not mapping: data=%lx mapped=%d\n"),
 485                  (unsigned long) i->data, (int) i->mapped);
 486       else
 487         fprintf (stderr, _("not mapping: env var not set\n"));
 488     }
 489 #else
 490   ok_to_map = 0;
 491 #endif
 492
 493 #ifdef HAVE_MPROTECT
 494   if (!writable)
 495     {
 496       size_to_alloc += pagesize - 1;
 497       size_to_alloc -= size_to_alloc % pagesize;
 498     }
 499 #endif
 500   if (debug_windows)
 501     fprintf (stderr, "\n\t%s(%6ld)",
 502              i->data ? "realloc" : " malloc", (long) size_to_alloc);
 503   i->data = (PTR) bfd_realloc (i->data, size_to_alloc);
 504   if (debug_windows)
 505     fprintf (stderr, "\t-> %p\n", i->data);
 506   i->refcount = 1;
 507   if (i->data == NULL)
 508     {
 509       if (size_to_alloc == 0)
 510         return true;
 511       bfd_set_error (bfd_error_no_memory);
 512       return false;
 513     }
 514   if (bfd_seek (abfd, offset, SEEK_SET) != 0)
 515     return false;
 516   i->size = bfd_read (i->data, size, 1, abfd);
 517   if (i->size != size)
 518     return false;
 519   i->mapped = 0;
 520 #ifdef HAVE_MPROTECT
 521   if (!writable)
 522     {
 523       if (debug_windows)
 524         fprintf (stderr, "\tmprotect (%p, %ld, PROT_READ)\n", i->data,
 525                  (long) i->size);
 526       mprotect (i->data, i->size, PROT_READ);
 527     }
 528 #endif
 529   windowp->data = i->data;
 530   windowp->size = i->size;
 531   return true;
 532 }
 533
 534 #endif /* USE_MMAP */
 535 \f
 536 bfd_size_type
 537 bfd_write (ptr, size, nitems, abfd)
 538      CONST PTR ptr;
 539      bfd_size_type size;
 540      bfd_size_type nitems;
 541      bfd *abfd;
 542 {
 543   long nwrote;
 544
 545   if ((abfd->flags & BFD_IN_MEMORY) != 0)
 546     {
 547       struct bfd_in_memory *bim = (struct bfd_in_memory *) (abfd->iostream);
 548       size *= nitems;
 549       if (abfd->where + size > bim->size)
 550         {
 551           long newsize, oldsize = (bim->size + 127) & ~127;
 552           bim->size = abfd->where + size;
 553           /* Round up to cut down on memory fragmentation */
 554           newsize = (bim->size + 127) & ~127;
 555           if (newsize > oldsize)
 556             {
 557               bim->buffer = bfd_realloc (bim->buffer, newsize);
 558               if (bim->buffer == 0)
 559                 {
 560                   bim->size = 0;
 561                   return 0;
 562                 }
 563             }
 564         }
 565       memcpy (bim->buffer + abfd->where, ptr, size);
 566       abfd->where += size;
 567       return size;
 568     }
 569
 570   nwrote = fwrite (ptr, 1, (size_t) (size * nitems),
 571                    bfd_cache_lookup (abfd));
 572   if (nwrote > 0)
 573     abfd->where += nwrote;
 574   if ((bfd_size_type) nwrote != size * nitems)
 575     {
 576 #ifdef ENOSPC
 577       if (nwrote >= 0)
 578         errno = ENOSPC;
 579 #endif
 580       bfd_set_error (bfd_error_system_call);
 581     }
 582   return nwrote;
 583 }
 584
 585 /*
 586 INTERNAL_FUNCTION
 587         bfd_write_bigendian_4byte_int
 588
 589 SYNOPSIS
 590         void bfd_write_bigendian_4byte_int(bfd *abfd,  int i);
 591
 592 DESCRIPTION
 593         Write a 4 byte integer @var{i} to the output BFD @var{abfd}, in big
 594         endian order regardless of what else is going on.  This is useful in
 595         archives.
 596
 597 */
 598 void
 599 bfd_write_bigendian_4byte_int (abfd, i)
 600      bfd *abfd;
 601      int i;
 602 {
 603   bfd_byte buffer[4];
 604   bfd_putb32(i, buffer);
 605   if (bfd_write((PTR)buffer, 4, 1, abfd) != 4)
 606     abort ();
 607 }
 608
 609 long
 610 bfd_tell (abfd)
 611      bfd *abfd;
 612 {
 613   file_ptr ptr;
 614
 615   if ((abfd->flags & BFD_IN_MEMORY) != 0)
 616     return abfd->where;
 617
 618   ptr = ftell (bfd_cache_lookup(abfd));
 619
 620   if (abfd->my_archive)
 621     ptr -= abfd->origin;
 622   abfd->where = ptr;
 623   return ptr;
 624 }
 625
 626 int
 627 bfd_flush (abfd)
 628      bfd *abfd;
 629 {
 630   if ((abfd->flags & BFD_IN_MEMORY) != 0)
 631     return 0;
 632   return fflush (bfd_cache_lookup(abfd));
 633 }
 634
 635 /* Returns 0 for success, negative value for failure (in which case
 636    bfd_get_error can retrieve the error code).  */
 637 int
 638 bfd_stat (abfd, statbuf)
 639      bfd *abfd;
 640      struct stat *statbuf;
 641 {
 642   FILE *f;
 643   int result;
 644
 645   if ((abfd->flags & BFD_IN_MEMORY) != 0)
 646     abort ();
 647
 648   f = bfd_cache_lookup (abfd);
 649   if (f == NULL)
 650     {
 651       bfd_set_error (bfd_error_system_call);
 652       return -1;
 653     }
 654   result = fstat (fileno (f), statbuf);
 655   if (result < 0)
 656     bfd_set_error (bfd_error_system_call);
 657   return result;
 658 }
 659
 660 /* Returns 0 for success, nonzero for failure (in which case bfd_get_error
 661    can retrieve the error code).  */
 662
 663 int
 664 bfd_seek (abfd, position, direction)
 665      bfd *abfd;
 666      file_ptr position;
 667      int direction;
 668 {
 669   int result;
 670   FILE *f;
 671   file_ptr file_position;
 672   /* For the time being, a BFD may not seek to it's end.  The problem
 673      is that we don't easily have a way to recognize the end of an
 674      element in an archive. */
 675
 676   BFD_ASSERT (direction == SEEK_SET || direction == SEEK_CUR);
 677
 678   if (direction == SEEK_CUR && position == 0)
 679     return 0;
 680
 681   if ((abfd->flags & BFD_IN_MEMORY) != 0)
 682     {
 683       struct bfd_in_memory *bim;
 684
 685       bim = (struct bfd_in_memory *) abfd->iostream;
 686
 687       if (direction == SEEK_SET)
 688         abfd->where = position;
 689       else
 690         abfd->where += position;
 691
 692       if ((bfd_size_type) abfd->where > bim->size)
 693         {
 694           abfd->where = bim->size;
 695           bfd_set_error (bfd_error_file_truncated);
 696           return -1;
 697         }
 698
 699       return 0;
 700     }
 701
 702   if (abfd->format != bfd_archive && abfd->my_archive == 0)
 703     {
 704 #if 0
 705       /* Explanation for this code: I'm only about 95+% sure that the above
 706          conditions are sufficient and that all i/o calls are properly
 707          adjusting the `where' field.  So this is sort of an `assert'
 708          that the `where' field is correct.  If we can go a while without
 709          tripping the abort, we can probably safely disable this code,
 710          so that the real optimizations happen.  */
 711       file_ptr where_am_i_now;
 712       where_am_i_now = ftell (bfd_cache_lookup (abfd));
 713       if (abfd->my_archive)
 714         where_am_i_now -= abfd->origin;
 715       if (where_am_i_now != abfd->where)
 716         abort ();
 717 #endif
 718       if (direction == SEEK_SET && position == abfd->where)
 719         return 0;
 720     }
 721   else
 722     {
 723       /* We need something smarter to optimize access to archives.
 724          Currently, anything inside an archive is read via the file
 725          handle for the archive.  Which means that a bfd_seek on one
 726          component affects the `current position' in the archive, as
 727          well as in any other component.
 728
 729          It might be sufficient to put a spike through the cache
 730          abstraction, and look to the archive for the file position,
 731          but I think we should try for something cleaner.
 732
 733          In the meantime, no optimization for archives.  */
 734     }
 735
 736   f = bfd_cache_lookup (abfd);
 737   file_position = position;
 738   if (direction == SEEK_SET && abfd->my_archive != NULL)
 739     file_position += abfd->origin;
 740
 741   result = fseek (f, file_position, direction);
 742
 743   if (result != 0)
 744     {
 745       int hold_errno = errno;
 746
 747       /* Force redetermination of `where' field.  */
 748       bfd_tell (abfd);
 749
 750       /* An EINVAL error probably means that the file offset was
 751          absurd.  */
 752       if (hold_errno == EINVAL)
 753         bfd_set_error (bfd_error_file_truncated);
 754       else
 755         {
 756           bfd_set_error (bfd_error_system_call);
 757           errno = hold_errno;
 758         }
 759     }
 760   else
 761     {
 762       /* Adjust `where' field.  */
 763       if (direction == SEEK_SET)
 764         abfd->where = position;
 765       else
 766         abfd->where += position;
 767     }
 768   return result;
 769 }
 770 \f
 771 /** The do-it-yourself (byte) sex-change kit */
 772
 773 /* The middle letter e.g. get<b>short indicates Big or Little endian
 774    target machine.  It doesn't matter what the byte order of the host
 775    machine is; these routines work for either.  */
 776
 777 /* FIXME: Should these take a count argument?
 778    Answer (gnu@cygnus.com):  No, but perhaps they should be inline
 779                              functions in swap.h #ifdef __GNUC__.
 780                              Gprof them later and find out.  */
 781
 782 /*
 783 FUNCTION
 784         bfd_put_size
 785 FUNCTION
 786         bfd_get_size
 787
 788 DESCRIPTION
 789         These macros as used for reading and writing raw data in
 790         sections; each access (except for bytes) is vectored through
 791         the target format of the BFD and mangled accordingly. The
 792         mangling performs any necessary endian translations and
 793         removes alignment restrictions.  Note that types accepted and
 794         returned by these macros are identical so they can be swapped
 795         around in macros---for example, @file{libaout.h} defines <<GET_WORD>>
 796         to either <<bfd_get_32>> or <<bfd_get_64>>.
 797
 798         In the put routines, @var{val} must be a <<bfd_vma>>.  If we are on a
 799         system without prototypes, the caller is responsible for making
 800         sure that is true, with a cast if necessary.  We don't cast
 801         them in the macro definitions because that would prevent <<lint>>
 802         or <<gcc -Wall>> from detecting sins such as passing a pointer.
 803         To detect calling these with less than a <<bfd_vma>>, use
 804         <<gcc -Wconversion>> on a host with 64 bit <<bfd_vma>>'s.
 805
 806 .
 807 .{* Byte swapping macros for user section data.  *}
 808 .
 809 .#define bfd_put_8(abfd, val, ptr) \
 810 .                ((void) (*((unsigned char *)(ptr)) = (unsigned char)(val)))
 811 .#define bfd_put_signed_8 \
 812 .               bfd_put_8
 813 .#define bfd_get_8(abfd, ptr) \
 814 .                (*(unsigned char *)(ptr))
 815 .#define bfd_get_signed_8(abfd, ptr) \
 816 .               ((*(unsigned char *)(ptr) ^ 0x80) - 0x80)
 817 .
 818 .#define bfd_put_16(abfd, val, ptr) \
 819 .                BFD_SEND(abfd, bfd_putx16, ((val),(ptr)))
 820 .#define bfd_put_signed_16 \
 821 .                bfd_put_16
 822 .#define bfd_get_16(abfd, ptr) \
 823 .                BFD_SEND(abfd, bfd_getx16, (ptr))
 824 .#define bfd_get_signed_16(abfd, ptr) \
 825 .                BFD_SEND (abfd, bfd_getx_signed_16, (ptr))
 826 .
 827 .#define bfd_put_32(abfd, val, ptr) \
 828 .                BFD_SEND(abfd, bfd_putx32, ((val),(ptr)))
 829 .#define bfd_put_signed_32 \
 830 .                bfd_put_32
 831 .#define bfd_get_32(abfd, ptr) \
 832 .                BFD_SEND(abfd, bfd_getx32, (ptr))
 833 .#define bfd_get_signed_32(abfd, ptr) \
 834 .                BFD_SEND(abfd, bfd_getx_signed_32, (ptr))
 835 .
 836 .#define bfd_put_64(abfd, val, ptr) \
 837 .                BFD_SEND(abfd, bfd_putx64, ((val), (ptr)))
 838 .#define bfd_put_signed_64 \
 839 .                bfd_put_64
 840 .#define bfd_get_64(abfd, ptr) \
 841 .                BFD_SEND(abfd, bfd_getx64, (ptr))
 842 .#define bfd_get_signed_64(abfd, ptr) \
 843 .                BFD_SEND(abfd, bfd_getx_signed_64, (ptr))
 844 .
 845 .#define bfd_get(bits, abfd, ptr)                               \
 846 .                ((bits) == 8 ? bfd_get_8 (abfd, ptr)           \
 847 .                : (bits) == 16 ? bfd_get_16 (abfd, ptr)        \
 848 .                : (bits) == 32 ? bfd_get_32 (abfd, ptr)        \
 849 .                : (bits) == 64 ? bfd_get_64 (abfd, ptr)        \
 850 .                : (abort (), (bfd_vma) - 1))
 851 .
 852 .#define bfd_put(bits, abfd, val, ptr)                          \
 853 .                ((bits) == 8 ? bfd_put_8 (abfd, val, ptr)      \
 854 .                : (bits) == 16 ? bfd_put_16 (abfd, val, ptr)   \
 855 .                : (bits) == 32 ? bfd_put_32 (abfd, val, ptr)   \
 856 .                : (bits) == 64 ? bfd_put_64 (abfd, val, ptr)   \
 857 .                : (abort (), (void) 0))
 858 .
 859 */
 860
 861 /*
 862 FUNCTION
 863         bfd_h_put_size
 864         bfd_h_get_size
 865
 866 DESCRIPTION
 867         These macros have the same function as their <<bfd_get_x>>
 868         bretheren, except that they are used for removing information
 869         for the header records of object files. Believe it or not,
 870         some object files keep their header records in big endian
 871         order and their data in little endian order.
 872 .
 873 .{* Byte swapping macros for file header data.  *}
 874 .
 875 .#define bfd_h_put_8(abfd, val, ptr) \
 876 .               bfd_put_8 (abfd, val, ptr)
 877 .#define bfd_h_put_signed_8(abfd, val, ptr) \
 878 .               bfd_put_8 (abfd, val, ptr)
 879 .#define bfd_h_get_8(abfd, ptr) \
 880 .               bfd_get_8 (abfd, ptr)
 881 .#define bfd_h_get_signed_8(abfd, ptr) \
 882 .               bfd_get_signed_8 (abfd, ptr)
 883 .
 884 .#define bfd_h_put_16(abfd, val, ptr) \
 885 .                BFD_SEND(abfd, bfd_h_putx16,(val,ptr))
 886 .#define bfd_h_put_signed_16 \
 887 .                bfd_h_put_16
 888 .#define bfd_h_get_16(abfd, ptr) \
 889 .                BFD_SEND(abfd, bfd_h_getx16,(ptr))
 890 .#define bfd_h_get_signed_16(abfd, ptr) \
 891 .                BFD_SEND(abfd, bfd_h_getx_signed_16, (ptr))
 892 .
 893 .#define bfd_h_put_32(abfd, val, ptr) \
 894 .                BFD_SEND(abfd, bfd_h_putx32,(val,ptr))
 895 .#define bfd_h_put_signed_32 \
 896 .                bfd_h_put_32
 897 .#define bfd_h_get_32(abfd, ptr) \
 898 .                BFD_SEND(abfd, bfd_h_getx32,(ptr))
 899 .#define bfd_h_get_signed_32(abfd, ptr) \
 900 .                BFD_SEND(abfd, bfd_h_getx_signed_32, (ptr))
 901 .
 902 .#define bfd_h_put_64(abfd, val, ptr) \
 903 .                BFD_SEND(abfd, bfd_h_putx64,(val, ptr))
 904 .#define bfd_h_put_signed_64 \
 905 .                bfd_h_put_64
 906 .#define bfd_h_get_64(abfd, ptr) \
 907 .                BFD_SEND(abfd, bfd_h_getx64,(ptr))
 908 .#define bfd_h_get_signed_64(abfd, ptr) \
 909 .                BFD_SEND(abfd, bfd_h_getx_signed_64, (ptr))
 910 .
 911 */
 912
 913 /* Sign extension to bfd_signed_vma.  */
 914 #define COERCE16(x) (((bfd_signed_vma) (x) ^ 0x8000) - 0x8000)
 915 #define COERCE32(x) \
 916   ((bfd_signed_vma) (long) (((unsigned long) (x) ^ 0x80000000) - 0x80000000))
 917 #define EIGHT_GAZILLION (((BFD_HOST_64_BIT)0x80000000) << 32)
 918 #define COERCE64(x) \
 919   (((bfd_signed_vma) (x) ^ EIGHT_GAZILLION) - EIGHT_GAZILLION)
 920
 921 bfd_vma
 922 bfd_getb16 (addr)
 923      register const bfd_byte *addr;
 924 {
 925   return (addr[0] << 8) | addr[1];
 926 }
 927
 928 bfd_vma
 929 bfd_getl16 (addr)
 930      register const bfd_byte *addr;
 931 {
 932   return (addr[1] << 8) | addr[0];
 933 }
 934
 935 bfd_signed_vma
 936 bfd_getb_signed_16 (addr)
 937      register const bfd_byte *addr;
 938 {
 939   return COERCE16((addr[0] << 8) | addr[1]);
 940 }
 941
 942 bfd_signed_vma
 943 bfd_getl_signed_16 (addr)
 944      register const bfd_byte *addr;
 945 {
 946   return COERCE16((addr[1] << 8) | addr[0]);
 947 }
 948
 949 void
 950 bfd_putb16 (data, addr)
 951      bfd_vma data;
 952      register bfd_byte *addr;
 953 {
 954   addr[0] = (bfd_byte)(data >> 8);
 955   addr[1] = (bfd_byte )data;
 956 }
 957
 958 void
 959 bfd_putl16 (data, addr)
 960      bfd_vma data;
 961      register bfd_byte *addr;
 962 {
 963   addr[0] = (bfd_byte )data;
 964   addr[1] = (bfd_byte)(data >> 8);
 965 }
 966
 967 bfd_vma
 968 bfd_getb32 (addr)
 969      register const bfd_byte *addr;
 970 {
 971   unsigned long v;
 972
 973   v = (unsigned long) addr[0] << 24;
 974   v |= (unsigned long) addr[1] << 16;
 975   v |= (unsigned long) addr[2] << 8;
 976   v |= (unsigned long) addr[3];
 977   return (bfd_vma) v;
 978 }
 979
 980 bfd_vma
 981 bfd_getl32 (addr)
 982      register const bfd_byte *addr;
 983 {
 984   unsigned long v;
 985
 986   v = (unsigned long) addr[0];
 987   v |= (unsigned long) addr[1] << 8;
 988   v |= (unsigned long) addr[2] << 16;
 989   v |= (unsigned long) addr[3] << 24;
 990   return (bfd_vma) v;
 991 }
 992
 993 bfd_signed_vma
 994 bfd_getb_signed_32 (addr)
 995      register const bfd_byte *addr;
 996 {
 997   unsigned long v;
 998
 999   v = (unsigned long) addr[0] << 24;
1000   v |= (unsigned long) addr[1] << 16;
1001   v |= (unsigned long) addr[2] << 8;
1002   v |= (unsigned long) addr[3];
1003   return COERCE32 (v);
1004 }
1005
1006 bfd_signed_vma
1007 bfd_getl_signed_32 (addr)
1008      register const bfd_byte *addr;
1009 {
1010   unsigned long v;
1011
1012   v = (unsigned long) addr[0];
1013   v |= (unsigned long) addr[1] << 8;
1014   v |= (unsigned long) addr[2] << 16;
1015   v |= (unsigned long) addr[3] << 24;
1016   return COERCE32 (v);
1017 }
1018
1019 bfd_vma
1020 bfd_getb64 (addr)
1021      register const bfd_byte *addr ATTRIBUTE_UNUSED;
1022 {
1023 #ifdef BFD64
1024   bfd_vma low, high;
1025
1026   high= ((((((((addr[0]) << 8) |
1027               addr[1]) << 8) |
1028             addr[2]) << 8) |
1029           addr[3]) );
1030
1031   low = (((((((((bfd_vma)addr[4]) << 8) |
1032               addr[5]) << 8) |
1033             addr[6]) << 8) |
1034           addr[7]));
1035
1036   return high << 32 | low;
1037 #else
1038   BFD_FAIL();
1039   return 0;
1040 #endif
1041 }
1042
1043 bfd_vma
1044 bfd_getl64 (addr)
1045      register const bfd_byte *addr ATTRIBUTE_UNUSED;
1046 {
1047 #ifdef BFD64
1048   bfd_vma low, high;
1049   high= (((((((addr[7] << 8) |
1050               addr[6]) << 8) |
1051             addr[5]) << 8) |
1052           addr[4]));
1053
1054   low = ((((((((bfd_vma)addr[3] << 8) |
1055               addr[2]) << 8) |
1056             addr[1]) << 8) |
1057           addr[0]) );
1058
1059   return high << 32 | low;
1060 #else
1061   BFD_FAIL();
1062   return 0;
1063 #endif
1064
1065 }
1066
1067 bfd_signed_vma
1068 bfd_getb_signed_64 (addr)
1069      register const bfd_byte *addr ATTRIBUTE_UNUSED;
1070 {
1071 #ifdef BFD64
1072   bfd_vma low, high;
1073
1074   high= ((((((((addr[0]) << 8) |
1075               addr[1]) << 8) |
1076             addr[2]) << 8) |
1077           addr[3]) );
1078
1079   low = (((((((((bfd_vma)addr[4]) << 8) |
1080               addr[5]) << 8) |
1081             addr[6]) << 8) |
1082           addr[7]));
1083
1084   return COERCE64(high << 32 | low);
1085 #else
1086   BFD_FAIL();
1087   return 0;
1088 #endif
1089 }
1090
1091 bfd_signed_vma
1092 bfd_getl_signed_64 (addr)
1093      register const bfd_byte *addr ATTRIBUTE_UNUSED;
1094 {
1095 #ifdef BFD64
1096   bfd_vma low, high;
1097   high= (((((((addr[7] << 8) |
1098               addr[6]) << 8) |
1099             addr[5]) << 8) |
1100           addr[4]));
1101
1102   low = ((((((((bfd_vma)addr[3] << 8) |
1103               addr[2]) << 8) |
1104             addr[1]) << 8) |
1105           addr[0]) );
1106
1107   return COERCE64(high << 32 | low);
1108 #else
1109   BFD_FAIL();
1110   return 0;
1111 #endif
1112 }
1113
1114 void
1115 bfd_putb32 (data, addr)
1116      bfd_vma data;
1117      register bfd_byte *addr;
1118 {
1119         addr[0] = (bfd_byte)(data >> 24);
1120         addr[1] = (bfd_byte)(data >> 16);
1121         addr[2] = (bfd_byte)(data >>  8);
1122         addr[3] = (bfd_byte)data;
1123 }
1124
1125 void
1126 bfd_putl32 (data, addr)
1127      bfd_vma data;
1128      register bfd_byte *addr;
1129 {
1130         addr[0] = (bfd_byte)data;
1131         addr[1] = (bfd_byte)(data >>  8);
1132         addr[2] = (bfd_byte)(data >> 16);
1133         addr[3] = (bfd_byte)(data >> 24);
1134 }
1135
1136 void
1137 bfd_putb64 (data, addr)
1138      bfd_vma data ATTRIBUTE_UNUSED;
1139      register bfd_byte *addr ATTRIBUTE_UNUSED;
1140 {
1141 #ifdef BFD64
1142   addr[0] = (bfd_byte)(data >> (7*8));
1143   addr[1] = (bfd_byte)(data >> (6*8));
1144   addr[2] = (bfd_byte)(data >> (5*8));
1145   addr[3] = (bfd_byte)(data >> (4*8));
1146   addr[4] = (bfd_byte)(data >> (3*8));
1147   addr[5] = (bfd_byte)(data >> (2*8));
1148   addr[6] = (bfd_byte)(data >> (1*8));
1149   addr[7] = (bfd_byte)(data >> (0*8));
1150 #else
1151   BFD_FAIL();
1152 #endif
1153 }
1154
1155 void
1156 bfd_putl64 (data, addr)
1157      bfd_vma data ATTRIBUTE_UNUSED;
1158      register bfd_byte *addr ATTRIBUTE_UNUSED;
1159 {
1160 #ifdef BFD64
1161   addr[7] = (bfd_byte)(data >> (7*8));
1162   addr[6] = (bfd_byte)(data >> (6*8));
1163   addr[5] = (bfd_byte)(data >> (5*8));
1164   addr[4] = (bfd_byte)(data >> (4*8));
1165   addr[3] = (bfd_byte)(data >> (3*8));
1166   addr[2] = (bfd_byte)(data >> (2*8));
1167   addr[1] = (bfd_byte)(data >> (1*8));
1168   addr[0] = (bfd_byte)(data >> (0*8));
1169 #else
1170   BFD_FAIL();
1171 #endif
1172 }
1173 \f
1174 /* Default implementation */
1175
1176 boolean
1177 _bfd_generic_get_section_contents (abfd, section, location, offset, count)
1178      bfd *abfd;
1179      sec_ptr section;
1180      PTR location;
1181      file_ptr offset;
1182      bfd_size_type count;
1183 {
1184   if (count == 0)
1185     return true;
1186
1187   if ((bfd_size_type) (offset + count) > section->_raw_size)
1188     {
1189       bfd_set_error (bfd_error_invalid_operation);
1190       return false;
1191     }
1192
1193   if (bfd_seek (abfd, section->filepos + offset, SEEK_SET) != 0
1194       || bfd_read (location, (bfd_size_type) 1, count, abfd) != count)
1195     return false;
1196
1197   return true;
1198 }
1199
1200 boolean
1201 _bfd_generic_get_section_contents_in_window (abfd, section, w, offset, count)
1202      bfd *abfd ATTRIBUTE_UNUSED;
1203      sec_ptr section ATTRIBUTE_UNUSED;
1204      bfd_window *w ATTRIBUTE_UNUSED;
1205      file_ptr offset ATTRIBUTE_UNUSED;
1206      bfd_size_type count ATTRIBUTE_UNUSED;
1207 {
1208 #ifdef USE_MMAP
1209   if (count == 0)
1210     return true;
1211   if (abfd->xvec->_bfd_get_section_contents != _bfd_generic_get_section_contents)
1212     {
1213       /* We don't know what changes the bfd's get_section_contents
1214          method may have to make.  So punt trying to map the file
1215          window, and let get_section_contents do its thing.  */
1216       /* @@ FIXME : If the internal window has a refcount of 1 and was
1217          allocated with malloc instead of mmap, just reuse it.  */
1218       bfd_free_window (w);
1219       w->i = (bfd_window_internal *) bfd_zmalloc (sizeof (bfd_window_internal));
1220       if (w->i == NULL)
1221         return false;
1222       w->i->data = (PTR) bfd_malloc ((size_t) count);
1223       if (w->i->data == NULL)
1224         {
1225           free (w->i);
1226           w->i = NULL;
1227           return false;
1228         }
1229       w->i->mapped = 0;
1230       w->i->refcount = 1;
1231       w->size = w->i->size = count;
1232       w->data = w->i->data;
1233       return bfd_get_section_contents (abfd, section, w->data, offset, count);
1234     }
1235   if ((bfd_size_type) (offset+count) > section->_raw_size
1236       || (bfd_get_file_window (abfd, section->filepos + offset, count, w, true)
1237           == false))
1238     return false;
1239   return true;
1240 #else
1241   abort ();
1242 #endif
1243 }
1244
1245 /* This generic function can only be used in implementations where creating
1246    NEW sections is disallowed.  It is useful in patching existing sections
1247    in read-write files, though.  See other set_section_contents functions
1248    to see why it doesn't work for new sections.  */
1249 boolean
1250 _bfd_generic_set_section_contents (abfd, section, location, offset, count)
1251      bfd *abfd;
1252      sec_ptr section;
1253      PTR location;
1254      file_ptr offset;
1255      bfd_size_type count;
1256 {
1257   if (count == 0)
1258     return true;
1259
1260   if (bfd_seek (abfd, (file_ptr) (section->filepos + offset), SEEK_SET) == -1
1261       || bfd_write (location, (bfd_size_type) 1, count, abfd) != count)
1262     return false;
1263
1264   return true;
1265 }
1266
1267 /*
1268 INTERNAL_FUNCTION
1269         bfd_log2
1270
1271 SYNOPSIS
1272         unsigned int bfd_log2(bfd_vma x);
1273
1274 DESCRIPTION
1275         Return the log base 2 of the value supplied, rounded up.  E.g., an
1276         @var{x} of 1025 returns 11.
1277 */
1278
1279 unsigned int
1280 bfd_log2 (x)
1281      bfd_vma x;
1282 {
1283   unsigned int result = 0;
1284
1285   while ((x = (x >> 1)) != 0)
1286     ++result;
1287   return result;
1288 }
1289
1290 boolean
1291 bfd_generic_is_local_label_name (abfd, name)
1292      bfd *abfd;
1293      const char *name;
1294 {
1295   char locals_prefix = (bfd_get_symbol_leading_char (abfd) == '_') ? 'L' : '.';
1296
1297   return (name[0] == locals_prefix);
1298 }
1299
1300 /*  Can be used from / for bfd_merge_private_bfd_data to check that
1301     endianness matches between input and output file.  Returns
1302     true for a match, otherwise returns false and emits an error.  */
1303 boolean
1304 _bfd_generic_verify_endian_match (ibfd, obfd)
1305      bfd *ibfd;
1306      bfd *obfd;
1307 {
1308   if (ibfd->xvec->byteorder != obfd->xvec->byteorder
1309       && obfd->xvec->byteorder != BFD_ENDIAN_UNKNOWN)
1310     {
1311       (*_bfd_error_handler)
1312         ("%s: compiled for a %s endian system and target is %s endian",
1313          bfd_get_filename (ibfd),
1314          bfd_big_endian (ibfd) ? "big" : "little",
1315          bfd_big_endian (obfd) ? "big" : "little");
1316
1317       bfd_set_error (bfd_error_wrong_format);
1318       return false;
1319     }
1320
1321   return true;
1322 }