Y2038: provide size of default time_t for target architecture

    To determine whether the default time_t interfaces are 32-bit
    and so need conversions, or are 64-bit and so are compatible
    with the internal 64-bit type without conversions, a macro
    giving the size of the  default time_t is also required.
    This macro is called __TIMESIZE.

    This macro can then be used instead of __WORDSIZE in msq-pad.h
    and shm-pad.h files, which in turn allows removing their x86
    variants, and in sem-pad.h files but keeping the x86 variant.

    This patch was tested by running 'make check' on branch master
    then applying this patch and running 'make check' again, and
    checking that both 'make check' yield identical results.
    This was done on x86_64-linux-gnu and i686-linux-gnu.

	* bits/timesize.h: New file.
	* stdlib/Makefile (headers): Add bits/timesize.h.
	* sysdeps/unix/sysv/linux/bits/msq-pad.h
	(__MSQ_PAD_AFTER_TIME): Use __TIMESIZE instead of __WORDSIZE.
	* sysdeps/unix/sysv/linux/bits/sem-pad.h
	(__SEM_PAD_AFTER_TIME): Likewise.
	* sysdeps/unix/sysv/linux/bits/shm-pad.h
	(__SHM_PAD_AFTER_TIME): Likewise.
	* sysdeps/unix/sysv/linux/hppa/bits/msq-pad.h
	(__MSQ_PAD_BEFORE_TIME): Likewise.
	* sysdeps/unix/sysv/linux/hppa/bits/sem-pad.h
	(__SEM_PAD_BEFORE_TIME): Likewise.
	* sysdeps/unix/sysv/linux/hppa/bits/shm-pad.h
	(__SHM_PAD_BEFORE_TIME, __SHM_PAD_BETWEEN_TIME_AND_SEGSZ): Likewise.
	* sysdeps/unix/sysv/linux/mips/bits/msq-pad.h
        (__MSQ_PAD_AFTER_TIME, __MSQ_PAD_BEFORE_TIME): Likewise.
        * sysdeps/unix/sysv/linux/powerpc/bits/msq-pad.h
        (__MSQ_PAD_BEFORE_TIME): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/bits/sem-pad.h
	(__SEM_PAD_BEFORE_TIME): Likewise.
	* sysdeps/unix/sysv/linux/powerpc/bits/shm-pad.h
	(__SHM_PAD_BEFORE_TIME, __SHM_PAD_BETWEEN_TIME_AND_SEGSZ): Likewise.
	* sysdeps/unix/sysv/linux/sparc/bits/msq-pad.h
	(__MSQ_PAD_BEFORE_TIME): Likewise.
	* sysdeps/unix/sysv/linux/sparc/bits/sem-pad.h
	(__SEM_PAD_BEFORE_TIME): Likewise.
	* sysdeps/unix/sysv/linux/sparc/bits/shm-pad.h
	(__SHM_PAD_BEFORE_TIME): Likewise.
	* sysdeps/unix/sysv/linux/x86/bits/msq-pad.h: Delete file.
	* sysdeps/unix/sysv/linux/x86/bits/shm-pad.h: Likewise.
	* sysdeps/unix/sysv/linux/x86/bits/timesize.h: New file.

2 files changed, 6 insertions, 39 deletions

diff --git a/sysdeps/unix/sysv/linux/x86/bits/shm-pad.h b/sysdeps/unix/sysv/linux/x86/bits/shm-pad.h
deleted file mode 100644
index 277a70fe6c..0000000000
--- a/sysdeps/unix/sysv/linux/x86/bits/shm-pad.h
+++ /dev/null
@@ -1,30 +0,0 @@
-/* Define where padding goes in struct shmid_ds.  x86 version.
-   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/>.  */
-
-#ifndef _SYS_SHM_H
-# error "Never use <bits/shm-pad.h> directly; include <sys/shm.h> instead."
-#endif
-
-#ifdef __x86_64__
-# define __SHM_PAD_AFTER_TIME 0
-#else
-# define __SHM_PAD_AFTER_TIME 1
-#endif
-#define __SHM_PAD_BEFORE_TIME 0
-#define __SHM_SEGSZ_AFTER_TIME 0
-#define __SHM_PAD_BETWEEN_TIME_AND_SEGSZ 0
diff --git a/sysdeps/unix/sysv/linux/x86/bits/msq-pad.h b/sysdeps/unix/sysv/linux/x86/bits/timesize.h
index 5d46956c77..8b88ab84b0 100644
--- a/sysdeps/unix/sysv/linux/x86/bits/msq-pad.h
+++ b/sysdeps/unix/sysv/linux/x86/bits/timesize.h
@@ -1,4 +1,4 @@
-/* Define where padding goes in struct msqid_ds.  x86 version.
+/* Bit size of the time_t type at glibc build time, x86-64 and x32 case.
    Copyright (C) 2018 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
@@ -16,13 +16,10 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#ifndef _SYS_MSG_H
-# error "Never use <bits/msq-pad.h> directly; include <sys/msg.h> instead."
-#endif
-
-#ifdef __x86_64__
-# define __MSQ_PAD_AFTER_TIME 0
+#if defined __x86_64__ && defined __ILP32__
+/* For x32, time is 64-bit even though word size is 32-bit.  */
+# define __TIMESIZE	64
 #else
-# define __MSQ_PAD_AFTER_TIME 1
+/* For others, time size is word size.  */
+# define __TIMESIZE	__WORDSIZE
 #endif
-#define __MSQ_PAD_BEFORE_TIME 0