2004-04-21 Andrew Cagney <cagney@redhat.com>

	* opncls.c (_bfd_new_bfd_contained_in): Copy "iovec".
	(struct opncls, opncls_btell, opncls_bseek, opncls_bread)
	(opncls_bwrite, opncls_bclose, opncls_bflush)
	(opncls_bstat, opncls_iovec, bfd_openr_iovec): Implement a
	bfd iovec that uses function callbacks.
	(bfd_close): Use the iovec's bclose.
	* cache.c (cache_btell, cache_bseek, cache_bread, cache_bwrite)
	(cache_bclose, cache_bflush, cache_bstat)
	(cache_iovec): New functions and global variable, implement a
	cache "iovec", where applicable set bfd_error.
	(bfd_cache_init, bfd_cache_close): Set/test the bfd's iovec.
	* bfdio.c (struct bfd_iovec): Define.
	(real_read): Delete function.
	(bfd_bread, bfd_bread, bfd_bwrite, bfd_tell, bfd_flush, bfd_stat)
	(bfd_seek, bfd_get_mtime, bfd_get_size): Use the bfd's "iovec",
	assume that bread and bwrite set bfd_error.
	* bfd.c (struct bfd): Add "iovec", update comments.
	* bfd-in2.h, libbfd.h: Re-generate.

1 files changed, 39 insertions, 63 deletions

diff --git a/bfd/bfdio.c b/bfd/bfdio.c
index a90cb33ea5..53534f4f66 100644
--- a/bfd/bfdio.c
+++ b/bfd/bfdio.c
@@ -62,37 +62,41 @@ real_fseek (FILE *file, file_ptr offset, int whence)
 #endif
 }
 
-/* Note that archive entries don't have streams; they share their parent's.
-   This allows someone to play with the iostream behind BFD's back.
+/*
+INTERNAL_DEFINITION
+	struct bfd_iovec
 
-   Also, note that the origin pointer points to the beginning of a file's
-   contents (0 for non-archive elements).  For archive entries this is the
-   first octet in the file, NOT the beginning of the archive header.  */
+DESCRIPTION
 
-static size_t
-real_read (void *where, size_t a, size_t b, FILE *file)
-{
-  /* FIXME - this looks like an optimization, but it's really to cover
-     up for a feature of some OSs (not solaris - sigh) that
-     ld/pe-dll.c takes advantage of (apparently) when it creates BFDs
-     internally and tries to link against them.  BFD seems to be smart
-     enough to realize there are no symbol records in the "file" that
-     doesn't exist but attempts to read them anyway.  On Solaris,
-     attempting to read zero bytes from a NULL file results in a core
-     dump, but on other platforms it just returns zero bytes read.
-     This makes it to something reasonable. - DJ */
-  if (a == 0 || b == 0)
-    return 0;
+	The <<struct bfd_iovec>> contains the internal file I/O class.
+	Each <<BFD>> has an instance of this class and all file I/O is
+	routed through it (it is assumed that the instance implements
+	all methods listed below).
+
+.struct bfd_iovec
+.{
+.  {* To avoid problems with macros, a "b" rather than "f"
+.     prefix is prepended to each method name.  *}
+.  {* Attempt to read/write NBYTES on ABFD's IOSTREAM storing/fetching
+.     bytes starting at PTR.  Return the number of bytes actually
+.     transfered (a read past end-of-file returns less than NBYTES),
+.     or -1 (setting <<bfd_error>>) if an error occurs.  *}
+.  file_ptr (*bread) (struct bfd *abfd, void *ptr, file_ptr nbytes);
+.  file_ptr (*bwrite) (struct bfd *abfd, const void *ptr,
+.                      file_ptr nbytes);
+.  {* Return the current IOSTREAM file offset, or -1 (setting <<bfd_error>>
+.     if an error occurs.  *}
+.  file_ptr (*btell) (struct bfd *abfd);
+.  {* For the following, on successful completion a value of 0 is returned.
+.     Otherwise, a value of -1 is returned (and  <<bfd_error>> is set).  *}
+.  int (*bseek) (struct bfd *abfd, file_ptr offset, int whence);
+.  int (*bclose) (struct bfd *abfd);
+.  int (*bflush) (struct bfd *abfd);
+.  int (*bstat) (struct bfd *abfd, struct stat *sb);
+.};
 
+*/
 
-#if defined (__VAX) && defined (VMS)
-  /* Apparently fread on Vax VMS does not keep the record length
-     information.  */
-  return read (fileno (file), where, a * b);
-#else
-  return fread (where, a, b, file);
-#endif
-}
 
 /* Return value is amount read.  */
 
@@ -121,25 +125,10 @@ bfd_bread (void *ptr, bfd_size_type size, bfd *abfd)
       return get;
     }
 
-  nread = real_read (ptr, 1, (size_t) size, bfd_cache_lookup (abfd));
+  nread = abfd->iovec->bread (abfd, ptr, size);
   if (nread != (size_t) -1)
     abfd->where += nread;
 
-  /* Set bfd_error if we did not read as much data as we expected.
-
-     If the read failed due to an error set the bfd_error_system_call,
-     else set bfd_error_file_truncated.
-
-     A BFD backend may wish to override bfd_error_file_truncated to
-     provide something more useful (eg. no_symbols or wrong_format).  */
-  if (nread != size)
-    {
-      if (ferror (bfd_cache_lookup (abfd)))
-	bfd_set_error (bfd_error_system_call);
-      else
-	bfd_set_error (bfd_error_file_truncated);
-    }
-
   return nread;
 }
 
@@ -175,7 +164,7 @@ bfd_bwrite (const void *ptr, bfd_size_type size, bfd *abfd)
       return size;
     }
 
-  nwrote = fwrite (ptr, 1, (size_t) size, bfd_cache_lookup (abfd));
+  nwrote = abfd->iovec->bwrite (abfd, ptr, size);
   if (nwrote != (size_t) -1)
     abfd->where += nwrote;
   if (nwrote != size)
@@ -196,7 +185,7 @@ bfd_tell (bfd *abfd)
   if ((abfd->flags & BFD_IN_MEMORY) != 0)
     return abfd->where;
 
-  ptr = real_ftell (bfd_cache_lookup (abfd));
+  ptr = abfd->iovec->btell (abfd);
 
   if (abfd->my_archive)
     ptr -= abfd->origin;
@@ -209,7 +198,7 @@ bfd_flush (bfd *abfd)
 {
   if ((abfd->flags & BFD_IN_MEMORY) != 0)
     return 0;
-  return fflush (bfd_cache_lookup(abfd));
+  return abfd->iovec->bflush (abfd);
 }
 
 /* Returns 0 for success, negative value for failure (in which case
@@ -217,19 +206,12 @@ bfd_flush (bfd *abfd)
 int
 bfd_stat (bfd *abfd, struct stat *statbuf)
 {
-  FILE *f;
   int result;
 
   if ((abfd->flags & BFD_IN_MEMORY) != 0)
     abort ();
 
-  f = bfd_cache_lookup (abfd);
-  if (f == NULL)
-    {
-      bfd_set_error (bfd_error_system_call);
-      return -1;
-    }
-  result = fstat (fileno (f), statbuf);
+  result = abfd->iovec->bstat (abfd, statbuf);
   if (result < 0)
     bfd_set_error (bfd_error_system_call);
   return result;
@@ -242,7 +224,6 @@ int
 bfd_seek (bfd *abfd, file_ptr position, int direction)
 {
   int result;
-  FILE *f;
   file_ptr file_position;
   /* For the time being, a BFD may not seek to it's end.  The problem
      is that we don't easily have a way to recognize the end of an
@@ -328,12 +309,11 @@ bfd_seek (bfd *abfd, file_ptr position, int direction)
 	 In the meantime, no optimization for archives.  */
     }
 
-  f = bfd_cache_lookup (abfd);
   file_position = position;
   if (direction == SEEK_SET && abfd->my_archive != NULL)
     file_position += abfd->origin;
 
-  result = real_fseek (f, file_position, direction);
+  result = abfd->iovec->bseek (abfd, file_position, direction);
   if (result != 0)
     {
       int hold_errno = errno;
@@ -378,14 +358,12 @@ DESCRIPTION
 long
 bfd_get_mtime (bfd *abfd)
 {
-  FILE *fp;
   struct stat buf;
 
   if (abfd->mtime_set)
     return abfd->mtime;
 
-  fp = bfd_cache_lookup (abfd);
-  if (0 != fstat (fileno (fp), &buf))
+  if (abfd->iovec->bstat (abfd, &buf) != 0)
     return 0;
 
   abfd->mtime = buf.st_mtime;		/* Save value in case anyone wants it */
@@ -428,14 +406,12 @@ DESCRIPTION
 long
 bfd_get_size (bfd *abfd)
 {
-  FILE *fp;
   struct stat buf;
 
   if ((abfd->flags & BFD_IN_MEMORY) != 0)
     return ((struct bfd_in_memory *) abfd->iostream)->size;
 
-  fp = bfd_cache_lookup (abfd);
-  if (0 != fstat (fileno (fp), & buf))
+  if (abfd->iovec->bstat (abfd, &buf) != 0)
     return 0;
 
   return buf.st_size;