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, 139 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/scandir64.c b/sysdeps/unix/sysv/linux/scandir64.c
new file mode 100644
index 0000000000..efb502f6e4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/scandir64.c
@@ -0,0 +1,139 @@
+/* Copyright (C) 2000-2018 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/>.  */
+
+#define scandir __no_scandir_decl
+#include <dirent.h>
+#undef scandir
+
+int
+__scandir64 (const char *dir, struct dirent64 ***namelist,
+	   int (*select) (const struct dirent64 *),
+	   int (*cmp) (const struct dirent64 **, const struct dirent64 **))
+{
+  return __scandir64_tail (__opendir (dir), namelist, select, cmp);
+}
+
+#if _DIRENT_MATCHES_DIRENT64
+weak_alias (__scandir64, scandir64)
+weak_alias (__scandir64, scandir)
+#else
+# include <shlib-compat.h>
+versioned_symbol (libc, __scandir64, scandir64, GLIBC_2_2);
+# if SHLIB_COMPAT (libc, GLIBC_2_1, GLIBC_2_2)
+#  include <string.h>
+#  include <errno.h>
+#  include "olddirent.h"
+
+int
+__old_scandir64 (const char *dir, struct __old_dirent64 ***namelist,
+		 int (*select) (const struct __old_dirent64 *),
+		 int (*cmp) (const struct __old_dirent64 **,
+			     const struct __old_dirent64 **))
+{
+  DIR *dp = __opendir (dir);
+  struct __old_dirent64 **v = NULL;
+  size_t vsize = 0;
+  struct scandir_cancel_struct c;
+  struct __old_dirent64 *d;
+  int save;
+
+  if (dp == NULL)
+    return -1;
+
+  save = errno;
+  __set_errno (0);
+
+  c.dp = dp;
+  c.v = NULL;
+  c.cnt = 0;
+  __libc_cleanup_push (__scandir_cancel_handler, &c);
+
+  while ((d = __old_readdir64 (dp)) != NULL)
+    {
+      int use_it = select == NULL;
+
+      if (! use_it)
+	{
+	  use_it = select (d);
+	  /* The select function might have changed errno.  It was
+	     zero before and it need to be again to make the latter
+	     tests work.  */
+	  __set_errno (0);
+	}
+
+      if (use_it)
+	{
+	  struct __old_dirent64 *vnew;
+	  size_t dsize;
+
+	  /* Ignore errors from select or readdir */
+	  __set_errno (0);
+
+	  if (__glibc_unlikely (c.cnt == vsize))
+	    {
+	      struct __old_dirent64 **new;
+	      if (vsize == 0)
+		vsize = 10;
+	      else
+		vsize *= 2;
+	      new = (struct __old_dirent64 **) realloc (v,
+							vsize * sizeof (*v));
+	      if (new == NULL)
+		break;
+	      v = new;
+	      c.v = (void *) v;
+	    }
+
+	  dsize = &d->d_name[_D_ALLOC_NAMLEN (d)] - (char *) d;
+	  vnew = (struct __old_dirent64 *) malloc (dsize);
+	  if (vnew == NULL)
+	    break;
+
+	  v[c.cnt++] = (struct __old_dirent64 *) memcpy (vnew, d, dsize);
+	}
+    }
+
+  if (__builtin_expect (errno, 0) != 0)
+    {
+      save = errno;
+
+      while (c.cnt > 0)
+	free (v[--c.cnt]);
+      free (v);
+      c.cnt = -1;
+    }
+  else
+    {
+      /* Sort the list if we have a comparison function to sort with.  */
+      if (cmp != NULL)
+	qsort (v, c.cnt, sizeof (*v),
+	       (int (*) (const void *, const void *)) cmp);
+
+      *namelist = v;
+    }
+
+  __libc_cleanup_pop (0);
+
+  (void) __closedir (dp);
+  __set_errno (save);
+
+  return c.cnt;
+}
+compat_symbol (libc, __old_scandir64, scandir64, GLIBC_2_1);
+
+# endif /* SHLIB_COMPAT (libc, GLIBC_2_1, GLIBC_2_2)  */
+#endif /* _DIRENT_MATCHES_DIRENT64  */