Move common dirent implementation from sysdeps/unix to sysdeps/posix.

sysdeps/posix/readdir_r.c

@@ -0,0 +1,137 @@
+/* Copyright (C) 1991,92,93,94,95,96,97,98,99,2000,02,10
+	Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <limits.h>
+#include <stddef.h>
+#include <string.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <assert.h>
+
+#include <dirstream.h>
+
+#ifndef __READDIR_R
+# define __READDIR_R __readdir_r
+# define __GETDENTS __getdents
+# define DIRENT_TYPE struct dirent
+# define __READDIR_R_ALIAS
+#endif
+
+/* Read a directory entry from DIRP.  */
+int
+__READDIR_R (DIR *dirp, DIRENT_TYPE *entry, DIRENT_TYPE **result)
+{
+  DIRENT_TYPE *dp;
+  size_t reclen;
+  const int saved_errno = errno;
+
+  __libc_lock_lock (dirp->lock);
+
+  do
+    {
+      if (dirp->offset >= dirp->size)
+	{
+	  /* We've emptied out our buffer.  Refill it.  */
+
+	  size_t maxread;
+	  ssize_t bytes;
+
+#ifndef _DIRENT_HAVE_D_RECLEN
+	  /* Fixed-size struct; must read one at a time (see below).  */
+	  maxread = sizeof *dp;
+#else
+	  maxread = dirp->allocation;
+#endif
+
+	  bytes = __GETDENTS (dirp->fd, dirp->data, maxread);
+	  if (bytes <= 0)
+	    {
+	      /* On some systems getdents fails with ENOENT when the
+		 open directory has been rmdir'd already.  POSIX.1
+		 requires that we treat this condition like normal EOF.  */
+	      if (bytes < 0 && errno == ENOENT)
+		{
+		  bytes = 0;
+		  __set_errno (saved_errno);
+		}
+
+	      dp = NULL;
+	      /* Reclen != 0 signals that an error occurred.  */
+	      reclen = bytes != 0;
+	      break;
+	    }
+	  dirp->size = (size_t) bytes;
+
+	  /* Reset the offset into the buffer.  */
+	  dirp->offset = 0;
+	}
+
+      dp = (DIRENT_TYPE *) &dirp->data[dirp->offset];
+
+#ifdef _DIRENT_HAVE_D_RECLEN
+      reclen = dp->d_reclen;
+#else
+      /* The only version of `struct dirent*' that lacks `d_reclen'
+	 is fixed-size.  */
+      assert (sizeof dp->d_name > 1);
+      reclen = sizeof *dp;
+      /* The name is not terminated if it is the largest possible size.
+	 Clobber the following byte to ensure proper null termination.  We
+	 read just one entry at a time above so we know that byte will not
+	 be used later.  */
+      dp->d_name[sizeof dp->d_name] = '\0';
+#endif
+
+      dirp->offset += reclen;
+
+#ifdef _DIRENT_HAVE_D_OFF
+      dirp->filepos = dp->d_off;
+#else
+      dirp->filepos += reclen;
+#endif
+
+      /* Skip deleted files.  */
+    }
+  while (dp->d_ino == 0);
+
+  if (dp != NULL)
+    {
+#ifdef GETDENTS_64BIT_ALIGNED
+      /* The d_reclen value might include padding which is not part of
+	 the DIRENT_TYPE data structure.  */
+      reclen = MIN (reclen,
+		    offsetof (DIRENT_TYPE, d_name) + sizeof (dp->d_name));
+#endif
+      *result = memcpy (entry, dp, reclen);
+#ifdef GETDENTS_64BIT_ALIGNED
+      entry->d_reclen = reclen;
+#endif
+    }
+  else
+    *result = NULL;
+
+  __libc_lock_unlock (dirp->lock);
+
+  return dp != NULL ? 0 : reclen ? errno : 0;
+}
+
+#ifdef __READDIR_R_ALIAS
+weak_alias (__readdir_r, readdir_r)
+#endif