hurd: Fix dirfd symbol exposition from ftw

dirfd is XOPEN2K8 only, it should not be exposed along ftw which is earlier.

	* include/dirent.h (__dirfd): New declaration.
	* dirent/dirfd.c (dirfd): Rename to __dirfd, and redefine as weak
	alias.
	* sysdeps/posix/dirfd/dirfd.c (dirfd): Likewise.
	* sysdeps/mach/hurd/dirfd.c (dirfd): Likewise.
	* io/ftw.c (open_dir_stream, ftw_dir): Use __dirfd instead of dirfd.

ChangeLog

@@ -1,3 +1,12 @@
+2017-09-27  Samuel Thibault  <samuel.thibault@ens-lyon.org>
+
+	* include/dirent.h (__dirfd): New declaration.
+	* dirent/dirfd.c (dirfd): Rename to __dirfd, and redefine as weak
+	alias.
+	* sysdeps/posix/dirfd/dirfd.c (dirfd): Likewise.
+	* sysdeps/mach/hurd/dirfd.c (dirfd): Likewise.
+	* io/ftw.c (open_dir_stream, ftw_dir): Use __dirfd instead of dirfd.
+
 2017-09-26  H.J. Lu  <hongjiu.lu@intel.com>
 
 	[BZ #18822]

dirent/dirfd.c

@@ -21,10 +21,11 @@
 #include <errno.h>
 
 int
-dirfd (DIR *dirp)
+__dirfd (DIR *dirp)
 {
   __set_errno (ENOSYS);
   return -1;
 }
 
+weak_alias (__dirfd, dirfd)
 stub_warning (dirfd)

include/dirent.h

@@ -46,6 +46,7 @@ extern int __versionsort64 (const struct dirent64 **a,
 extern DIR *__alloc_dir (int fd, bool close_fd, int flags,
 			 const struct stat64 *statp) attribute_hidden;
 extern __typeof (rewinddir) __rewinddir;
+extern __typeof (dirfd) __dirfd;
 
 extern void __scandir_cancel_handler (void *arg) attribute_hidden;
 extern int __scandir_tail (DIR *dp,

io/ftw.c

@@ -361,7 +361,7 @@ open_dir_stream (int *dfdp, struct ftw_data *data, struct dir_data *dirp)
 	result = -1;
       else
 	{
-	  dirp->streamfd = dirfd (dirp->stream);
+	  dirp->streamfd = __dirfd (dirp->stream);
 	  dirp->content = NULL;
 	  data->dirstreams[data->actdir] = dirp;
 
@@ -518,7 +518,7 @@ fail:
   /* If necessary, change to this directory.  */
   if (data->flags & FTW_CHDIR)
     {
-      if (__fchdir (dirfd (dir.stream)) < 0)
+      if (__fchdir (__dirfd (dir.stream)) < 0)
 	{
 	  result = -1;
 	  goto fail;
@@ -602,7 +602,7 @@ fail:
       /* Change back to the parent directory.  */
       int done = 0;
       if (old_dir->stream != NULL)
-	if (__fchdir (dirfd (old_dir->stream)) == 0)
+	if (__fchdir (__dirfd (old_dir->stream)) == 0)
 	  done = 1;
 
       if (!done)

sysdeps/mach/hurd/dirfd.c

@@ -22,7 +22,7 @@
 #include <errno.h>
 
 int
-dirfd (DIR *dirp)
+__dirfd (DIR *dirp)
 {
   int fd;
 
@@ -41,3 +41,5 @@ dirfd (DIR *dirp)
 
   return fd;
 }
+
+weak_alias (__dirfd, dirfd)

sysdeps/posix/dirfd.c

@@ -22,7 +22,9 @@
 #undef dirfd
 
 int
-dirfd (DIR *dirp)
+__dirfd (DIR *dirp)
 {
   return dirp->fd;
 }
+
+weak_alias (__dirfd, dirfd)