Consolidate scandir{at}{64} implementation

This patch consolidates scandir{at}{64} implementation on just
the default dirent/scandir{at}{64}{_r}.c ones.  It changes the logic
to follow the conventions used on other code consolidation:

  * scandir{at} is only built for _DIRENT_MATCHES_DIRENT64 being 0.

  * scandir{at}{64} is always built and aliased to getdents for ABIs
    that define _DIRENT_MATCHES_DIRENT64 to 1.

Also on Linux the compat symbol for old non-LFS dirent64 definition
requires a platform-specific scandir64.c.

Checked on aarch64-linux-gnu, x86_64-linux-gnu, i686-linux-gnu,
sparcv9-linux-gnu, sparc64-linux-gnu, powerpc-linux-gnu, and
powerpc64le-linux-gnu.

	* dirent/scandir-tail-common.c: New file.
	* dirent/scandir-tail.c: Use scandir-tail-common.c.
	(__scandir_tail): Build iff _DIRENT_MATCHES_DIRENT64 is not defined.
	* dirent/scandir.c: Use scandir-tail-common.c.
	* dirent/scandirat.c: Likewise.
	* dirent/scandir64-tail.c: Use scandir-tail-common.c.
	* dirent/scandir64.c (scandir64): Always build and alias to scandir
	if _DIRENT_MATCHES_DIRENT64 is defined.
	* dirent/scandirat64.c (scandirat64): Likewise.
	* include/dirent.h (__scandir_tail): Only define iff
	_DIRENT_MATCHES_DIRENT64 is not defined.
	(__scandir64_tail): Define regardless.
	(__scandirat, scandirat64): Remove libc_hidden_proto.
	* sysdeps/unix/sysv/linux/arm/scandir64.c: Remove file.
	* sysdeps/unix/sysv/linux/m68k/scandir64.c: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/scandir64.c: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/scandir64.c: Likewise.
	* sysdeps/unix/sysv/linux/i386/scandir64.c: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/scandir64.c: Likewise.
	* sysdeps/unix/sysv/linux/scandir64.c: New file.

1 files changed, 6 insertions, 89 deletions

diff --git a/dirent/scandir-tail.c b/dirent/scandir-tail.c
index 67c9c92d65..7395dc4a26 100644
--- a/dirent/scandir-tail.c
+++ b/dirent/scandir-tail.c
@@ -17,96 +17,13 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <dirent.h>
-#include <errno.h>
-#include <stdlib.h>
-#include <string.h>
-#include <libc-lock.h>
 
-#ifndef SCANDIR_TAIL
-# define SCANDIR_TAIL	__scandir_tail
-# define READDIR	__readdir
-# define DIRENT_TYPE	struct dirent
-#endif
-
-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 set errno to non-zero on
-	     success.  It was zero before and it needs to be again to
-	     make the later tests work.  */
-	  __set_errno (0);
-
-          if (!selected)
-            continue;
-        }
+#if !_DIRENT_MATCHES_DIRENT64
 
-      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;
-        }
+# define SCANDIR_TAIL  __scandir_tail
+# define READDIR       __readdir
+# define DIRENT_TYPE   struct dirent
 
-      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);
+# include <dirent/scandir-tail-common.c>
 
-      /* Ignore errors from readdir, malloc or realloc.  These functions
-	 might have set errno to non-zero on success.  It was zero before
-	 and it needs to be again to make the latter tests work.  */
-      __set_errno (0);
-    }
-
-  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;
-}
+#endif