PING! Also, PING for parts 2/3 and 3/3 of this (loosely related) patch series:
http://gcc.gnu.org/ml/gcc-patches/2011-10/msg01642.html http://gcc.gnu.org/ml/gcc-patches/2011-10/msg01644.html On Tue, Oct 18, 2011 at 17:42, Janne Blomqvist <blomqvist.ja...@gmail.com> wrote: > Hi, > > in a few places in libgfortran we have some code for handling special > and/or non-seekable files differently. The problem is that special > files don't all have some nice consistent behavior. E.g. wrt. seeking, > some allow seeking just fine, others allow some seeks and not others, > others allow them but always return an offset of 0, and yet others > fail the seek completely. > > The Fortran standard doesn't really help here except for noting that > some files may not be positionable, and thus statements requiring the > file position to be modified may fail on such files. > > Obviously, libgfortran itself cannot enumerate all the possible > variations for how a special file may behave, and trying to impose > some kind of least common denominator may hide essential capability. > Having thought about this, my conclusion is that the only thing that > makes sense is that we do what the caller asks us to do, and if that > fails, we report the error back to the caller and let the caller > handle it. The attached patch implements this. > > Regtested on x86_64-unknown-linux-gnu, Ok for trunk? > > 2011-10-18 Janne Blomqvist <j...@gcc.gnu.org> > > * io/file_pos.c (st_rewind): Handle regular and special files > identically. > * io/intrinsics.c (fseek_sub): Don't check whether we think the > file is seekable, just do what the caller says. > * io/transfer.c (skip_record): First try to seek, then fallback to > reading and throwing away what we read. > * io/unit.c (update_position): Don't check whether file is > seekable, just try to do what we're told. > (unit_truncate): Likewise. > * io/unix.c (struct unix_stream): Remove special_file flag. > (buf_flush): Remove code for handling unseekable files. > (buf_seek): Likewise. > (fd_to_stream): Use buffered IO only for regular files. > (file_length): Remove is_seekable() call. > (is_seekable): Remove function. > (is_special): Likewise. > * io/unix.h: Remove prototypes for is_seekable and is_special. > > > -- > Janne Blomqvist > -- Janne Blomqvist
