Refactor scandir/scandirat to use common tail.

1 files changed, 110 insertions, 0 deletions

diff --git a/dirent/scandir-tail.c b/dirent/scandir-tail.c
new file mode 100644
index 0000000..4560834
--- /dev/null
+++ b/dirent/scandir-tail.c
@@ -0,0 +1,110 @@
+/* Logic guts of scandir*.
+   Copyright (C) 1992-2015 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 <dirent.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <bits/libc-lock.h>
+
+#ifndef SCANDIR_TAIL
+# define SCANDIR_TAIL	__scandir_tail
+# define READDIR	__readdir
+# define DIRENT_TYPE	struct dirent
+#endif
+
+internal_function
+int
+SCANDIR_TAIL (DIR *dp,
+              DIRENT_TYPE ***namelist,
+              int (*select) (const DIRENT_TYPE *),
+              int (*cmp) (const DIRENT_TYPE **, const DIRENT_TYPE **))
+{
+  if (dp == NULL)
+    return -1;
+
+  int save = errno;
+  __set_errno (0);
+
+  int result;
+  struct scandir_cancel_struct c = { .dp = dp };
+  __libc_cleanup_push (&__scandir_cancel_handler, &c);
+
+  DIRENT_TYPE **v = NULL;
+  size_t vsize = 0;
+  DIRENT_TYPE *d;
+  while ((d = READDIR (dp)) != NULL)
+    {
+      if (select != NULL)
+        {
+          int selected = (*select) (d);
+
+	  /* The SELECT function might have changed errno.  It was
+	     zero before and it need to be again to make the later
+	     tests work.  */
+	  __set_errno (0);
+
+          if (!selected)
+            continue;
+        }
+      else
+        __set_errno (0);
+
+      if (__glibc_unlikely (c.cnt == vsize))
+        {
+          if (vsize == 0)
+            vsize = 10;
+          else
+            vsize *= 2;
+          DIRENT_TYPE **new = realloc (v, vsize * sizeof *v);
+          if (new == NULL)
+            break;
+          c.v = v = new;
+        }
+
+      size_t dsize = &d->d_name[_D_ALLOC_NAMLEN (d)] - (char *) d;
+      DIRENT_TYPE *vnew = malloc (dsize);
+      if (vnew == NULL)
+        break;
+      v[c.cnt++] = (DIRENT_TYPE *) memcpy (vnew, d, dsize);
+    }
+
+  if (__glibc_likely (errno == 0))
+    {
+      __closedir (dp);
+
+      /* Sort the list if we have a comparison function to sort with.  */
+      if (cmp != NULL)
+	qsort (v, c.cnt, sizeof *v, (__compar_fn_t) cmp);
+
+      *namelist = v;
+      result = c.cnt;
+    }
+  else
+    {
+      /* This frees everything and calls closedir.  */
+      __scandir_cancel_handler (&c);
+      result = -1;
+    }
+
+  __libc_cleanup_pop (0);
+
+  if (result >= 0)
+    __set_errno (save);
+  return result;
+}