Re: new exports

[Corinna Vinschen <corinna-cygwin at cygwin dot com>]

On Sep 24 21:40, Eric Blake wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Followup to my faccessat patch.  Here's several functions exported by
> Linux which are trivial to support in cygwin, and which coreutils would
> like to use.  POSIX allows us to copy Linux' behavior about refusing to
> implement fchmodat(,AT_SYMLINK_NOFOLLOW) (aka BSD lchmod), so if/until we
> implement lchmod, we should not mistakenly change the permissions on the
> file the symlink is pointing to.  I've also posted a newlib patch to
> declare e[uid]access.
> 
> 2009-09-24  Eric Blake  <ebb9@byu.net>
> 
> 	* syscalls.cc (fchownat): lchmod is not yet implemented.
> 	(euidaccess): New function.
> 	* path.cc (realpath): Update comment.
> 	(canonicalize_file_name): New function.
> 	* include/cygwin/stdlib.h (canonicalize_file_name): Declare it.
> 	* include/cygwin/version.h (CYGWIN_VERSION_API_MINOR): Bump.
> 	* cygwin.din: Export canonicalize_file_name, eaccess, euidaccess.
> 	* posix.sgml: Mention them.

This is basically ok since it doesn't change any existing functionality
anyway.  Three points:

- Could you please add a patch to winsup/doc/new-features.sgml as
  well, adding the new entry points to the "other new APIs" paragraph in
  the file access related section?
  
- Please add the year 2008 to the copyright dates of include/cygwin/stdlib.h.
  Another one I forgot back then.  Thanks.

> @@ -3880,9 +3888,13 @@ fchmodat (int dirfd, const char *pathname, mode_t mode, int flags)
>    myfault efault;
>    if (efault.faulted (EFAULT))
>      return -1;
> -  if (flags & ~AT_SYMLINK_NOFOLLOW)
> +  if (flags)
>      {
> -      set_errno (EINVAL);
> +      /* BSD has lchmod, but Linux does not.  POSIX says
> +	 AT_SYMLINK_NOFOLLOW is allowed to fail with EOPNOTSUPP, but
> +	 only if pathname was a symlink; but Linux blindly fails with
> +	 ENOTSUP even for non-symlinks.  */
> +      set_errno ((flags & ~AT_SYMLINK_NOFOLLOW) ? EINVAL : ENOTSUP);
>        return -1;

- Please use EOPNOTSUPP, rather than ENOTSUP.  Linux doesn't actually
  have ENOTSUP.  It defines ENOTSUP == EOPNOTSUPP, see
  /usr/include/bits/errno.h.  The comment can simply refer to POSIX
  instead of to Linux.


Thanks,
Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat