[v3,1/3] bits/sem.h: Split out struct semid_ds

diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 60dc5cf9e5..cd6721bdbb 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -86,7 +86,7 @@  sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \
 		  bits/siginfo-arch.h bits/siginfo-consts-arch.h \
 		  bits/procfs.h bits/procfs-id.h bits/procfs-extra.h \
 		  bits/procfs-prregset.h bits/mman-map-flags-generic.h \
-		  bits/msq-pad.h bits/sem-pad.h bits/shmlba.h bits/shm-pad.h \
+		  bits/msq-pad.h bits/semid_ds_t.h bits/sem-pad.h bits/shmlba.h bits/shm-pad.h \
 		  bits/termios-struct.h bits/termios-c_cc.h \
 		  bits/termios-c_iflag.h bits/termios-c_oflag.h \
 		  bits/termios-baud.h bits/termios-c_cflag.h \
diff --git a/sysdeps/unix/sysv/linux/bits/sem.h b/sysdeps/unix/sysv/linux/bits/sem.h
index e0f4155c67..5c2f6be4c3 100644
--- a/sysdeps/unix/sysv/linux/bits/sem.h
+++ b/sysdeps/unix/sysv/linux/bits/sem.h
@@ -21,6 +21,7 @@ 
 
 #include <sys/types.h>
 #include <bits/sem-pad.h>
+#include <bits/semid_ds_t.h>
 
 /* Flags for `semop'.  */
 #define SEM_UNDO	0x1000		/* undo the operation on exit */
@@ -34,29 +35,6 @@ 
 #define SETVAL		16		/* set semval */
 #define SETALL		17		/* set all semval's */
 
-
-#if __SEM_PAD_BEFORE_TIME
-# define __SEM_PAD_TIME(NAME, RES)				\
-  __syscall_ulong_t __glibc_reserved ## RES; __time_t NAME
-#elif __SEM_PAD_AFTER_TIME
-# define __SEM_PAD_TIME(NAME, RES)				\
-  __time_t NAME; __syscall_ulong_t __glibc_reserved ## RES
-#else
-# define __SEM_PAD_TIME(NAME, RES)		\
-  __time_t NAME
-#endif
-
-/* Data structure describing a set of semaphores.  */
-struct semid_ds
-{
-  struct ipc_perm sem_perm;		/* operation permission struct */
-  __SEM_PAD_TIME (sem_otime, 1);	/* last semop() time */
-  __SEM_PAD_TIME (sem_ctime, 2);	/* last time changed by semctl() */
-  __syscall_ulong_t sem_nsems;		/* number of semaphores in set */
-  __syscall_ulong_t __glibc_reserved3;
-  __syscall_ulong_t __glibc_reserved4;
-};
-
 /* The user should define a union like the following to use it for arguments
    for `semctl'.
 
diff --git a/sysdeps/unix/sysv/linux/bits/semid_ds_t.h b/sysdeps/unix/sysv/linux/bits/semid_ds_t.h
new file mode 100644
index 0000000000..baed55ca8b
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/bits/semid_ds_t.h
@@ -0,0 +1,43 @@ 
+/* Generic implementation of the semaphore struct semid_ds
+   Copyright (C) 1995-2020 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
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_SEM_H
+# error "Never include <bits/semid_ds_t.h> directly; use <sys/sem.h> instead."
+#endif
+
+#if __SEM_PAD_BEFORE_TIME
+# define __SEM_PAD_TIME(NAME, RES)        \
+  __syscall_ulong_t __glibc_reserved ## RES; __time_t NAME
+#elif __SEM_PAD_AFTER_TIME
+# define __SEM_PAD_TIME(NAME, RES)        \
+  __time_t NAME; __syscall_ulong_t __glibc_reserved ## RES
+#else
+# define __SEM_PAD_TIME(NAME, RES)    \
+  __time_t NAME
+#endif
+
+/* Data structure describing a set of semaphores.  */
+struct semid_ds
+{
+  struct ipc_perm sem_perm;		/* operation permission struct */
+  __SEM_PAD_TIME (sem_otime, 1);	/* last semop() time */
+  __SEM_PAD_TIME (sem_ctime, 2);	/* last time changed by semctl() */
+  __syscall_ulong_t sem_nsems;		/* number of semaphores in set */
+  __syscall_ulong_t __glibc_reserved3;
+  __syscall_ulong_t __glibc_reserved4;
+};