bfd/opncls.c

   1 /* Copyright (C) 1990, 1991 Free Software Foundation, Inc.
   2
   3 This file is part of BFD, the Binary File Diddler.
   4
   5 BFD is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation; either version 1, or (at your option)
   8 any later version.
   9
  10 BFD is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with BFD; see the file COPYING.  If not, write to
  17 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  18
  19 /* $Id$ */
  20
  21 /*** opncls.c -- open and close a bfd. */
  22
  23 #include "sysdep.h"
  24 #include "bfd.h"
  25 #include "libbfd.h"
  26
  27
  28
  29 extern void bfd_cache_init();
  30 FILE *bfd_open_file();
  31
  32 /* fdopen is a loser -- we should use stdio exclusively.  Unfortunately
  33    if we do that we can't use fcntl.  */
  34 \f
  35 /** Locking
  36
  37    Locking is loosely controlled by the preprocessor variable
  38    BFD_LOCKS.  I say loosely because Unix barely understands locking
  39    -- at least in BSD it doesn't affect programs which don't
  40    explicitly use it!  That is to say it's practically useless, though
  41    if everyone uses this library you'll be OK.
  42
  43    From among the many and varied lock facilities available, (none of
  44    which, of course, knows about any other) we use the fcntl locks,
  45    because they're Posix.
  46
  47    The reason that bfd_openr and bfd_fdopenr exist, yet only bfd_openw
  48    exists is because of locking.  When we do output, we lock the
  49    filename file for output, then open a temporary file which does not
  50    actually get its correct filename until closing time.  This is
  51    safest, but requires the asymmetry in read and write entry points.
  52
  53    Perhaps, since unix has so many different kinds of locking anyway,
  54    we should use the emacs lock scheme?... */
  55 \f
  56
  57 #define obstack_chunk_alloc malloc
  58 #define obstack_chunk_free free
  59
  60 bfd *new_bfd()
  61 {
  62   struct obstack tmp;
  63   bfd *nbfd;
  64   obstack_begin(&tmp,128);
  65
  66   nbfd = (bfd *)obstack_alloc(&tmp,sizeof(bfd));
  67   nbfd->memory = tmp;
  68
  69   nbfd->direction = no_direction;
  70   nbfd->iostream = NULL;
  71   nbfd->where = 0;
  72   nbfd->sections = (asection *)NULL;
  73   nbfd->format = bfd_unknown;
  74   nbfd->my_archive = (bfd *)NULL;
  75   nbfd->origin = 0;
  76   nbfd->opened_once = false;
  77   nbfd->output_has_begun = false;
  78   nbfd->section_count = 0;
  79   nbfd->usrdata = (PTR)NULL;
  80   nbfd->sections = (asection *)NULL;
  81   nbfd->cacheable = false;
  82   nbfd->flags = NO_FLAGS;
  83   return nbfd;
  84 }
  85 bfd *new_bfd_contained_in(obfd)
  86 bfd *obfd;
  87 {
  88         bfd *nbfd = new_bfd();
  89         nbfd->xvec = obfd->xvec;
  90         nbfd->my_archive = obfd;
  91         nbfd->direction = read_direction;
  92         return nbfd;
  93 }
  94
  95 /** bfd_openr, bfd_fdopenr -- open for reading.
  96   Returns a pointer to a freshly-allocated bfd on success, or NULL. */
  97
  98 bfd *
  99 DEFUN(bfd_openr, (filename, target),
 100       CONST char *filename AND
 101       CONST char *target)
 102 {
 103   bfd *nbfd;
 104   bfd_target *target_vec;
 105
 106   target_vec = bfd_find_target (target);
 107   if (target_vec == NULL) {
 108     bfd_error = invalid_target;
 109     return NULL;
 110   }
 111
 112   bfd_error = system_call_error;
 113   nbfd = new_bfd();
 114   if (nbfd == NULL) {
 115     bfd_error = no_memory;
 116     return NULL;
 117   }
 118
 119   nbfd->filename = filename;
 120   nbfd->xvec = target_vec;
 121   nbfd->direction = read_direction;
 122
 123   if (bfd_open_file (nbfd) == NULL) {
 124     bfd_error = system_call_error;      /* File didn't exist, or some such */
 125     bfd_release(nbfd,0);
 126     return NULL;
 127   }
 128   return nbfd;
 129 }
 130
 131
 132 /* Don't try to `optimize' this function:
 133
 134    o - We lock using stack space so that interrupting the locking
 135        won't cause a storage leak.
 136    o - We open the file stream last, since we don't want to have to
 137        close it if anything goes wrong.  Closing the stream means closing
 138        the file descriptor too, even though we didn't open it.
 139  */
 140
 141 bfd *
 142 DEFUN(bfd_fdopenr,(filename, target, fd),
 143       CONST char *filename AND
 144       CONST char *target AND
 145       int fd)
 146 {
 147   bfd *nbfd;
 148   bfd_target *target_vec;
 149   int fdflags;
 150 #ifdef BFD_LOCKS
 151   struct flock lock, *lockp = &lock;
 152 #endif
 153
 154   target_vec = bfd_find_target (target);
 155   if (target_vec == NULL) {
 156     bfd_error = invalid_target;
 157     return NULL;
 158   }
 159
 160   bfd_error = system_call_error;
 161
 162   fdflags = fcntl (fd, F_GETFL);
 163   if (fdflags == -1) return NULL;
 164
 165 #ifdef BFD_LOCKS
 166   lockp->l_type = F_RDLCK;
 167   if (fcntl (fd, F_SETLKW, lockp) == -1) return NULL;
 168 #endif
 169
 170   nbfd = new_bfd();
 171
 172   if (nbfd == NULL) {
 173     bfd_error = no_memory;
 174     return NULL;
 175   }
 176 #ifdef BFD_LOCKS
 177   nbfd->lock = (struct flock *) (nbfd + 1);
 178 #endif
 179   /* if the fd were open for read only, this still would not hurt: */
 180   nbfd->iostream = (char *) fdopen (fd, "r+");
 181   if (nbfd->iostream == NULL) {
 182     free (nbfd);
 183     return NULL;
 184   }
 185
 186   /* OK, put everything where it belongs */
 187
 188   nbfd->filename = filename;
 189   nbfd->xvec = target_vec;
 190
 191   /* As a special case we allow a FD open for read/write to
 192      be written through, although doing so requires that we end
 193      the previous clause with a preposition.  */
 194   switch (fdflags & O_ACCMODE) {
 195   case O_RDONLY: nbfd->direction = read_direction; break;
 196   case O_WRONLY: nbfd->direction = write_direction; break;
 197   case O_RDWR: nbfd->direction = both_direction; break;
 198   default: abort ();
 199   }
 200
 201 #ifdef BFD_LOCKS
 202   memcpy (nbfd->lock, lockp, sizeof (struct flock))
 203 #endif
 204
 205     bfd_cache_init (nbfd);
 206
 207   return nbfd;
 208 }
 209 \f
 210 /** bfd_openw -- open for writing.
 211   Returns a pointer to a freshly-allocated bfd on success, or NULL.
 212
 213   See comment by bfd_fdopenr before you try to modify this function. */
 214
 215 bfd *
 216 DEFUN(bfd_openw,(filename, target),
 217       CONST char *filename AND
 218       CONST char *target)
 219 {
 220   bfd *nbfd;
 221   bfd_target *target_vec;
 222
 223   target_vec = bfd_find_target (target);
 224   if (target_vec == NULL) return NULL;
 225
 226   bfd_error = system_call_error;
 227
 228   /* nbfd has to point to head of malloc'ed block so that bfd_close may
 229      reclaim it correctly. */
 230
 231   nbfd = new_bfd();
 232   if (nbfd == NULL) {
 233     bfd_error = no_memory;
 234     return NULL;
 235   }
 236
 237   nbfd->filename = filename;
 238   nbfd->xvec = target_vec;
 239   nbfd->direction = write_direction;
 240
 241   if (bfd_open_file (nbfd) == NULL) {
 242     bfd_error = system_call_error;      /* File not writeable, etc */
 243     free (nbfd);
 244     return NULL;
 245   }
 246   return nbfd;
 247 }
 248
 249
 250 \f
 251 /** Close up shop, get your deposit back. */
 252 boolean
 253 bfd_close (abfd)
 254      bfd *abfd;
 255 {
 256   if (BFD_SEND (abfd, _close_and_cleanup, (abfd)) != true) return false;
 257
 258   bfd_cache_close(abfd);
 259 /* If the file was open for writing and is now executable
 260   make it so */
 261   if (abfd->direction == write_direction
 262       && abfd->flags & EXEC_P) {
 263     struct stat buf;
 264     stat(abfd->filename, &buf);
 265     chmod(abfd->filename,buf.st_mode | S_IXUSR | S_IXGRP | S_IXOTH);
 266   }
 267   obstack_free(&abfd->memory, (PTR)0);
 268   return true;
 269 }
 270 /*
 271  called to create a bfd with no ascociated file or target
 272  */
 273 bfd *
 274 DEFUN(bfd_create,(filename, template),
 275       CONST char *filename AND
 276       CONST bfd *template)
 277 {
 278   bfd *nbfd = new_bfd();
 279   if (nbfd == (bfd *)NULL) {
 280     bfd_error = no_memory;
 281     return (bfd *)NULL;
 282   }
 283   nbfd->filename = filename;
 284   if(template) {
 285     nbfd->xvec = template->xvec;
 286   }
 287   nbfd->direction = no_direction;
 288   bfd_set_format(nbfd, bfd_object);
 289   return nbfd;
 290
 291
 292
 293 }
 294
 295 DEFUN(PTR bfd_alloc, (abfd, size),
 296       bfd *abfd AND
 297       size_t size)
 298 {
 299   PTR *res = obstack_alloc(&(abfd->memory),size);
 300   return res;
 301 }
 302
 303 DEFUN(PTR bfd_zalloc,(abfd, size),
 304       bfd *abfd AND
 305       size_t size)
 306 {
 307   PTR res = bfd_alloc(abfd, size);
 308   memset(res, 0, size);
 309   return res;
 310 }
 311
 312 DEFUN(PTR bfd_realloc,(abfd, old, size),
 313       bfd *abfd AND
 314       PTR old AND
 315       size_t size)
 316 {
 317   PTR res = bfd_alloc(abfd, size);
 318   memcpy(res, old, size);
 319   return res;
 320 }
 321
 322
 323 DEFUN(size_t bfd_alloc_size,(abfd),
 324       bfd *abfd)
 325 {
 326   struct _obstack_chunk *chunk = abfd->memory.chunk;
 327   size_t size = 0;
 328   while (chunk) {
 329     size += chunk->limit - &(chunk->contents[0]);
 330     chunk = chunk->prev;
 331   }
 332   return size;
 333 }