Consolidate Linux readdir{64}{_r} implementation

This patch consolidates Linux readdir{64}{_r} implementation on just
the default sysdeps/unix/sysv/linux/readdir{64}{_r}.c ones.  The
default implementation handle the Linux requirements:

  * readdir{_r} is only built for _DIRENT_MATCHES_DIRENT64 being 0.

  * readdir64{_r} is always built and aliased to readdir{_r} for
    ABI that define _DIRENT_MATCHES_DIRENT64.

  * A compat symbol is added for readdir64{_r} for ABI that used to
    export the old non-LFS version.

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.

	* sysdeps/posix/readdir.c (__READDIR, __GETDENTS, DIRENTY_TYPE,
	__READDIR_ALIAS): Undefine after usage.
	* sysdeps/posix/readdir_r.c (__READDIR_R, __GETDENTS, DIRENT_TYPE,
	__READDIR_R_ALIAS): Likewise.
	* sysdeps/unix/sysv/linux/arm/readdir64.c: Remove file.
	* sysdeps/unix/sysv/linux/arm/readdir64_r.c: Likewise.
	* sysdeps/unix/sysv/linux/m68k/readdir64.c: Likewise.
	* sysdeps/unix/sysv/linux/m68k/readdir64_r.c: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/readdir64.c: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/readdir64_r.c: Likewise.
	* sysdeps/unix/sysv/linux/i386/readdir64.c: Likewise.
	* sysdeps/unix/sysv/linux/i386/readdir64_r.c: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/readdir64.c: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/readdir64_r.c: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/readdir64.c: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/readdir64_r.c: Likewise.
	* sysdeps/unix/sysv/linux/wordsize-64/readdir.c: Likewise.
	* sysdeps/unix/sysv/linux/wordsize-64/readdir64.c: Likewise.
	* sysdeps/unix/sysv/linux/wordsize-64/readdir64_r.c: Likewise.
	* sysdeps/unix/sysv/linux/wordsize-64/readdir_r.c: Likewise.
	* sysdeps/unix/sysv/linux/readdir.c: New file.
	* sysdeps/unix/sysv/linux/readdir_r.c: Likewise.
	* sysdeps/unix/sysv/linux/readdir64.c: Add compat symbol if required.
	* sysdeps/unix/sysv/linux/readdir64_r.c: Likewise.

1 files changed, 49 insertions, 2 deletions

diff --git a/sysdeps/unix/sysv/linux/readdir64.c b/sysdeps/unix/sysv/linux/readdir64.c
index 6d154fe988..8f9308b651 100644
--- a/sysdeps/unix/sysv/linux/readdir64.c
+++ b/sysdeps/unix/sysv/linux/readdir64.c
@@ -1,8 +1,55 @@
-#define __READDIR __readdir64
-#define __GETDENTS __getdents64
+/* Read a directory.  Linux LFS version.
+   Copyright (C) 1997-2018 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/>.  */
+
+/* When _DIRENT_MATCHES_DIRENT64 is defined we can alias 'readdir64' to
+   'readdir'.  However the function signatures are not equal due
+   different return types, so we need to suppress {__}readdir so weak
+   and strong alias do not throw conflicting types errors.  */
+#define readdir   __no_readdir_decl
+#define __readdir __no___readdir_decl
+#include <dirent.h>
+
+#define __READDIR   __readdir64
+#define __GETDENTS  __getdents64
 #define DIRENT_TYPE struct dirent64
 
 #include <sysdeps/posix/readdir.c>
 
+#undef __readdir
+#undef readdir
+
 libc_hidden_def (__readdir64)
+#if _DIRENT_MATCHES_DIRENT64
+strong_alias (__readdir64, __readdir)
 weak_alias (__readdir64, readdir64)
+weak_alias (__readdir64, readdir)
+#else
+/* The compat code expects the 'struct direct' with d_ino being a __ino_t
+   instead of __ino64_t.  */
+# include <shlib-compat.h>
+versioned_symbol (libc, __readdir64, readdir64, GLIBC_2_2);
+# if SHLIB_COMPAT(libc, GLIBC_2_1, GLIBC_2_2)
+#  include <olddirent.h>
+#  define __READDIR   attribute_compat_text_section __old_readdir64
+#  define __GETDENTS  __old_getdents64
+#  define DIRENT_TYPE struct __old_dirent64
+#  include <sysdeps/posix/readdir.c>
+libc_hidden_def (__old_readdir64)
+compat_symbol (libc, __old_readdir64, readdir64, GLIBC_2_1);
+# endif /* SHLIB_COMPAT(libc, GLIBC_2_1, GLIBC_2_2)  */
+#endif /* _DIRENT_MATCHES_DIRENT64  */