[patch, libfortran] Fix for PR 21593

[Thomas Koenig]

Hi,

this fixes PR 21593.  It is regression-tested on i686-pc-linux-gnu.
I'd appreciate if somebody could actually test it on a system on
which dev_null.f90 fails (Steve?).

2005-07-11  Thomas Koenig  <Thomas.Koenig@online.de>

	io/unix.c:  Add member special_file to type unix_stream.
	(fd_truncate):  Don't call ftruncate or chsize if
	s refers to a special file.
	(fd_to_stream):  initialize s->special_file.

2005-07-11  Thomas Koenig  <Thomas.Koenig@online.de>

	dev_null.f90:  Remove targets.
-------------- next part --------------
Index: unix.c
===================================================================
RCS file: /cvs/gcc/gcc/libgfortran/io/unix.c,v
retrieving revision 1.29
diff -c -p -r1.29 unix.c
*** unix.c	18 Jun 2005 20:09:28 -0000	1.29
--- unix.c	11 Jul 2005 20:39:14 -0000
*************** typedef struct
*** 138,143 ****
--- 138,145 ----
    int prot;
    int ndirty;			/* Dirty bytes starting at dirty_offset */
  
+   int special_file;		/* =1 if the fd refers to a special file */
+ 
    unsigned unbuffered:1, mmaped:1;
  
    char small_buffer[BUFFER_SIZE];
*************** fd_truncate (unix_stream * s)
*** 509,521 ****
      return FAILURE;
  
    /* non-seekable files, like terminals and fifo's fail the lseek.
!      the fd is a regular file at this point */
! 
  #ifdef HAVE_FTRUNCATE
!   if (ftruncate (s->fd, s->logical_offset))
  #else
  #ifdef HAVE_CHSIZE
!   if (chsize (s->fd, s->logical_offset))
  #endif
  #endif
      {
--- 511,524 ----
      return FAILURE;
  
    /* non-seekable files, like terminals and fifo's fail the lseek.
!      Using ftruncate on a seekable special file (like /dev/null)
!      is undefined, so we treat it as if the ftruncate failed.
!   */
  #ifdef HAVE_FTRUNCATE
!   if (s->special_file || ftruncate (s->fd, s->logical_offset))
  #else
  #ifdef HAVE_CHSIZE
!   if (s->special_file || chsize (s->fd, s->logical_offset))
  #endif
  #endif
      {
*************** fd_to_stream (int fd, int prot, int avoi
*** 915,920 ****
--- 918,924 ----
  
    fstat (fd, &statbuf);
    s->file_length = S_ISREG (statbuf.st_mode) ? statbuf.st_size : -1;
+   s->special_file = !S_ISREG (statbuf.st_mode);
  
  #if HAVE_MMAP
    if (avoid_mmap)
-------------- next part --------------
Index: dev_null.f90
===================================================================
RCS file: /cvs/gcc/gcc/gcc/testsuite/gfortran.dg/dev_null.f90,v
retrieving revision 1.2
diff -c -p -r1.2 dev_null.f90
*** dev_null.f90	28 Jun 2005 12:51:09 -0000	1.2
--- dev_null.f90	11 Jul 2005 20:49:37 -0000
***************
*** 1,4 ****
! ! { dg-do run { target *-*-linux* *-*-solaris* } }
  ! This test currently only runs on systems where using ftruncate on
  !   /dev/null fails (errno set to EINVAL). See PR 21593 for details.
  !
--- 1,4 ----
! ! { dg-do run }
  ! This test currently only runs on systems where using ftruncate on
  !   /dev/null fails (errno set to EINVAL). See PR 21593 for details.
  !