Initial revision

bfd/opncls.c

@@ -0,0 +1,281 @@
+/* Copyright (C) 1990, 1991 Free Software Foundation, Inc.
+
+This file is part of BFD, the Binary File Diddler.
+
+BFD is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 1, or (at your option)
+any later version.
+
+BFD is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with BFD; see the file COPYING.  If not, write to
+the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+/* $Id$ */
+
+/*** opncls.c -- open and close a bfd. */
+
+#include "sysdep.h"
+#include "bfd.h"
+#include "libbfd.h"
+
+
+extern void bfd_cache_init();
+FILE *bfd_open_file();
+
+/* fdopen is a loser -- we should use stdio exclusively.  Unfortunately
+   if we do that we can't use fcntl.  */
+
+/** Locking 
+
+   Locking is loosely controlled by the preprocessor variable
+   BFD_LOCKS.  I say loosely because Unix barely understands locking
+   -- at least in BSD it doesn't affect programs which don't
+   explicitly use it!  That is to say it's practically useless, though
+   if everyone uses this library you'll be OK.
+
+   From among the many and varied lock facilities available, (none of
+   which, of course, knows about any other) we use the fcntl locks,
+   because they're Posix.
+
+   The reason that bfd_openr and bfd_fdopenr exist, yet only bfd_openw
+   exists is because of locking.  When we do output, we lock the
+   filename file for output, then open a temporary file which does not
+   actually get its correct filename until closing time.  This is
+   safest, but requires the asymmetry in read and write entry points.
+
+   Perhaps, since unix has so many different kinds of locking anyway,
+   we should use the emacs lock scheme?... */
+
+
+bfd *new_bfd()
+{
+  bfd *nbfd = (bfd *)zalloc(sizeof(bfd));
+
+  nbfd->direction = no_direction;
+  nbfd->iostream = NULL;
+  nbfd->where = 0;
+  nbfd->sections = (asection *)NULL;
+  nbfd->format = bfd_unknown;
+  nbfd->my_archive = (bfd *)NULL;
+  nbfd->origin = 0;				   
+  nbfd->opened_once = false;
+  nbfd->output_has_begun = false;
+  nbfd->section_count = 0;
+  nbfd->usrdata = (void *)NULL;
+  nbfd->sections = (asection *)NULL;
+  nbfd->cacheable = false;
+  nbfd->flags = NO_FLAGS;
+  return nbfd;
+}
+bfd *new_bfd_contained_in(obfd)
+bfd *obfd;
+{
+	bfd *nbfd = new_bfd(obfd);
+	nbfd->xvec = obfd->xvec;
+	nbfd->my_archive = obfd;
+	nbfd->direction = read_direction;
+	return nbfd;
+}
+
+/** bfd_openr, bfd_fdopenr -- open for reading.
+  Returns a pointer to a freshly-allocated bfd on success, or NULL. */
+
+bfd *
+bfd_openr (filename, target)
+     char *filename;
+     char *target;
+{
+  bfd *nbfd;
+  bfd_target *target_vec;
+
+  target_vec = bfd_find_target (target);
+  if (target_vec == NULL) {
+    bfd_error = invalid_target;
+    return NULL;
+  }
+
+  bfd_error = system_call_error;
+  nbfd = new_bfd();
+  if (nbfd == NULL) {
+    bfd_error = no_memory;
+    return NULL;
+  }
+
+  nbfd->filename = filename;
+  nbfd->xvec = target_vec;
+  nbfd->direction = read_direction; 
+
+  if (bfd_open_file (nbfd) == NULL) {
+    bfd_error = system_call_error;	/* File didn't exist, or some such */
+    free (nbfd);
+    return NULL;
+  }
+  return nbfd;
+}
+
+
+/* Don't try to `optimize' this function:
+
+   o - We lock using stack space so that interrupting the locking
+       won't cause a storage leak.
+   o - We open the file stream last, since we don't want to have to
+       close it if anything goes wrong.  Closing the stream means closing
+       the file descriptor too, even though we didn't open it.
+ */
+
+bfd *
+bfd_fdopenr (filename, target, fd)
+     char *filename;
+     char *target;
+     int fd;
+{
+  bfd *nbfd;
+  bfd_target *target_vec;
+  int fdflags;
+#ifdef BFD_LOCKS
+  struct flock lock, *lockp = &lock;
+#endif
+
+  target_vec = bfd_find_target (target);
+  if (target_vec == NULL) {
+    bfd_error = invalid_target;
+    return NULL;
+  }
+
+  bfd_error = system_call_error;
+  
+  fdflags = fcntl (fd, F_GETFL);
+  if (fdflags == -1) return NULL;
+
+#ifdef BFD_LOCKS
+  lockp->l_type = F_RDLCK;
+  if (fcntl (fd, F_SETLKW, lockp) == -1) return NULL;
+#endif
+
+  nbfd = new_bfd();
+
+  if (nbfd == NULL) {
+    bfd_error = no_memory;
+    return NULL;
+  }
+#ifdef BFD_LOCKS
+  nbfd->lock = (struct flock *) (nbfd + 1);
+#endif
+  /* if the fd were open for read only, this still would not hurt: */
+  nbfd->iostream = (char *) fdopen (fd, "r+"); 
+  if (nbfd->iostream == NULL) {
+    free (nbfd);
+    return NULL;
+  }
+  
+  /* OK, put everything where it belongs */
+
+  nbfd->filename = filename;
+  nbfd->xvec = target_vec;
+
+  /* As a special case we allow a FD open for read/write to
+     be written through, although doing so requires that we end
+     the previous clause with a preposition.  */
+  switch (fdflags & O_ACCMODE) {
+  case O_RDONLY: nbfd->direction = read_direction; break;
+  case O_WRONLY: nbfd->direction = write_direction; break;  
+  case O_RDWR: nbfd->direction = both_direction; break;
+  default: abort ();
+  }
+				   
+#ifdef BFD_LOCKS
+  memcpy (nbfd->lock, lockp, sizeof (struct flock))
+#endif
+
+    bfd_cache_init (nbfd);
+
+  return nbfd;
+}
+
+/** bfd_openw -- open for writing.
+  Returns a pointer to a freshly-allocated bfd on success, or NULL.
+
+  See comment by bfd_fdopenr before you try to modify this function. */
+
+bfd *
+bfd_openw (filename, target)
+     char *filename;
+     char *target;
+{
+  bfd *nbfd;
+  bfd_target *target_vec;
+  
+  target_vec = bfd_find_target (target);
+  if (target_vec == NULL) return NULL;
+
+  bfd_error = system_call_error;
+
+  /* nbfd has to point to head of malloc'ed block so that bfd_close may
+     reclaim it correctly. */
+
+  nbfd = new_bfd();
+  if (nbfd == NULL) {
+    bfd_error = no_memory;
+    return NULL;
+  }
+
+  nbfd->filename = filename;
+  nbfd->xvec = target_vec;
+  nbfd->direction = write_direction;
+
+  if (bfd_open_file (nbfd) == NULL) {
+    bfd_error = system_call_error;	/* File not writeable, etc */
+    free (nbfd);
+    return NULL;
+  }
+  return nbfd;
+}
+
+
+
+/** Close up shop, get your deposit back. */
+boolean
+bfd_close (abfd)
+     bfd *abfd;
+{
+  if (BFD_SEND (abfd, _close_and_cleanup, (abfd)) != true) return false;
+
+  bfd_cache_close(abfd);
+/* If the file was open for writing and is now executable
+  make it so */
+  if (abfd->direction == write_direction 
+      && abfd->flags & EXEC_P) {
+    struct stat buf;
+    stat(abfd->filename, &buf);
+    chmod(abfd->filename,buf.st_mode | S_IXUSR | S_IXGRP | S_IXOTH);
+  }
+  free (abfd);
+  return true;
+}
+/* 
+ called to create a bfd with no ascociated file or target 
+ */
+bfd *
+bfd_create(filename, template)
+char *filename;
+bfd *template;
+{
+  bfd *nbfd = new_bfd();
+  if (nbfd == (bfd *)NULL) {
+    bfd_error = no_memory;
+    return (bfd *)NULL;
+  }
+  nbfd->filename = filename;
+  nbfd->xvec = template->xvec;
+  nbfd->direction = no_direction;
+  return nbfd;
+
+
+
+}