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.

7 files changed, 149 insertions, 162 deletions

diff --git a/dirent/scandir-tail-common.c b/dirent/scandir-tail-common.c
new file mode 100644
index 0000000000..f89cf77b56
--- /dev/null
+++ b/dirent/scandir-tail-common.c
@@ -0,0 +1,103 @@
+/* Common implementation for scandir{at}.
+   Copyright (C) 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/>.  */
+
+#include <string.h>
+#include <errno.h>
+
+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 (__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);
+
+      /* 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;
+}
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
diff --git a/dirent/scandir.c b/dirent/scandir.c
index b24e15724c..6d8352dc9c 100644
--- a/dirent/scandir.c
+++ b/dirent/scandir.c
@@ -15,31 +15,14 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-/* We need to avoid the header declaration of scandir64, because
-   the types don't match scandir and then the compiler will
-   complain about the mismatch when we do the alias below.  */
-#define scandir64       __renamed_scandir64
-
 #include <dirent.h>
 
-#undef  scandir64
-
-#ifndef SCANDIR
-# define SCANDIR        scandir
-# define SCANDIR_TAIL   __scandir_tail
-# define DIRENT_TYPE    struct dirent
-#endif
-
-
+#if !_DIRENT_MATCHES_DIRENT64
 int
-SCANDIR (const char *dir,
-	 DIRENT_TYPE ***namelist,
-	 int (*select) (const DIRENT_TYPE *),
-	 int (*cmp) (const DIRENT_TYPE **, const DIRENT_TYPE **))
+scandir (const char *dir, struct dirent ***namelist,
+	 int (*select) (const struct dirent *),
+	 int (*cmp) (const struct dirent **, const struct dirent **))
 {
-  return SCANDIR_TAIL (__opendir (dir), namelist, select, cmp);
+  return __scandir_tail (__opendir (dir), namelist, select, cmp);
 }
-
-#if _DIRENT_MATCHES_DIRENT64
-weak_alias (scandir, scandir64)
 #endif
diff --git a/dirent/scandir64-tail.c b/dirent/scandir64-tail.c
index 8d5cc07748..4e873d47d6 100644
--- a/dirent/scandir64-tail.c
+++ b/dirent/scandir64-tail.c
@@ -18,9 +18,7 @@
 
 #include <dirent.h>
 
-#if !_DIRENT_MATCHES_DIRENT64
-# define SCANDIR_TAIL   __scandir64_tail
-# define READDIR        __readdir64
-# define DIRENT_TYPE    struct dirent64
-# include <scandir-tail.c>
-#endif
+#define SCANDIR_TAIL   __scandir64_tail
+#define READDIR        __readdir64
+#define DIRENT_TYPE    struct dirent64
+#include <scandir-tail-common.c>
diff --git a/dirent/scandir64.c b/dirent/scandir64.c
index 0c63fa97ef..6bdd4628ad 100644
--- a/dirent/scandir64.c
+++ b/dirent/scandir64.c
@@ -15,15 +15,18 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#define scandir __no_scandir_decl
 #include <dirent.h>
-
-/* scandir.c defines scandir64 as an alias if _DIRENT_MATCHES_DIRENT64.  */
-#if !_DIRENT_MATCHES_DIRENT64
-
-# define SCANDIR        scandir64
-# define SCANDIR_TAIL   __scandir64_tail
-# define DIRENT_TYPE    struct dirent64
-
-# include <dirent/scandir.c>
-
+#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, scandir)
 #endif
diff --git a/dirent/scandirat.c b/dirent/scandirat.c
index 96a1b0ed30..8dad1e8a21 100644
--- a/dirent/scandirat.c
+++ b/dirent/scandirat.c
@@ -15,35 +15,15 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-/* We need to avoid the header declaration of scandir64, because
-   the types don't match scandir and then the compiler will
-   complain about the mismatch when we do the alias below.  */
-#define scandirat64       __renamed_scandirat64
-
 #include <dirent.h>
 
-#undef  scandirat64
-
-#ifndef SCANDIRAT
-# define SCANDIRAT	__scandirat
-# define SCANDIR_TAIL	__scandir_tail
-# define DIRENT_TYPE	struct dirent
-# define SCANDIRAT_WEAK_ALIAS
-#endif
-
+#if !_DIRENT_MATCHES_DIRENT64
 int
-SCANDIRAT (int dfd, const char *dir,
-	   DIRENT_TYPE ***namelist,
-	   int (*select) (const DIRENT_TYPE *),
-	   int (*cmp) (const DIRENT_TYPE **, const DIRENT_TYPE **))
+__scandirat (int dfd, const char *dir, struct dirent ***namelist,
+	     int (*select) (const struct dirent *),
+	     int (*cmp) (const struct dirent **, const struct dirent **))
 {
-  return SCANDIR_TAIL (__opendirat (dfd, dir), namelist, select, cmp);
+  return __scandir_tail (__opendirat (dfd, dir), namelist, select, cmp);
 }
-libc_hidden_def (SCANDIRAT)
-#ifdef SCANDIRAT_WEAK_ALIAS
 weak_alias (__scandirat, scandirat)
 #endif
-
-#if _DIRENT_MATCHES_DIRENT64
-weak_alias (scandirat, scandirat64)
-#endif
diff --git a/dirent/scandirat64.c b/dirent/scandirat64.c
index 520ae7cad7..7e5e209cdf 100644
--- a/dirent/scandirat64.c
+++ b/dirent/scandirat64.c
@@ -15,15 +15,18 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#define scandirat __no_scandirat_decl
 #include <dirent.h>
-
-/* scandirat.c defines scandirat64 as an alias if _DIRENT_MATCHES_DIRENT64.  */
-#if !_DIRENT_MATCHES_DIRENT64
-
-# define SCANDIRAT      scandirat64
-# define SCANDIR_TAIL   __scandir64_tail
-# define DIRENT_TYPE    struct dirent64
-
-# include <scandirat.c>
-
+#undef scandirat
+
+int
+scandirat64 (int dfd, const char *dir, struct dirent64 ***namelist,
+	     int (*select) (const struct dirent64 *),
+	     int (*cmp) (const struct dirent64 **, const struct dirent64 **))
+{
+  return __scandir64_tail (__opendirat (dfd, dir), namelist, select, cmp);
+}
+
+#if _DIRENT_MATCHES_DIRENT64
+weak_alias (scandirat64, scandirat)
 #endif