Update from Gnulib

This incorporates:
2020-05-03 attribute: new module
2020-04-13 explicit_bzero: improve code style
2020-04-13 explicit_bzero: On native Windows, use SecureZeroMemory
2020-04-13 explicit_bzero: use memset_s() when available
2020-04-04 maint: remove a stray inter-word space
* build-aux/config.guess, build-aux/config.sub:
* build-aux/gitlog-to-changelog, build-aux/update-copyright:
* doc/misc/texinfo.tex, lib/explicit_bzero.c, lib/ieee754.in.h:
* lib/nstrftime.c, m4/explicit_bzero.m4, m4/gnulib-common.m4:
Copy from Gnulib.
* lib/attribute.h: New file, copied from Gnulib.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.

5 files changed, 87 insertions, 12 deletions

diff --git a/lib/attribute.h b/lib/attribute.h
new file mode 100644
index 00000000000..8ef9a399ade
--- /dev/null
+++ b/lib/attribute.h
@@ -0,0 +1,58 @@
+/* ATTRIBUTE_* macros for using attributes in GCC and similar compilers
+
+   Copyright 2020 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published
+   by the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+/* Written by Paul Eggert.  */
+
+/* Provide public ATTRIBUTE_* names for the private _GL_ATTRIBUTE_*
+   macros used within Gnulib.  */
+
+#ifndef _GL_ATTRIBUTE_H
+#define _GL_ATTRIBUTE_H
+
+/* C2X standard attributes have macro names that do not begin with
+   'ATTRIBUTE_'.  */
+#define DEPRECATED _GL_ATTRIBUTE_DEPRECATED
+#define FALLTHROUGH _GL_ATTRIBUTE_FALLTHROUGH
+#define MAYBE_UNUSED _GL_ATTRIBUTE_MAYBE_UNUSED
+#define NODISCARD _GL_ATTRIBUTE_NODISCARD
+
+/* Selected GCC attributes; see:
+   https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html
+   These names begin with 'ATTRIBUTE_' to avoid name clashes.  */
+#define ATTRIBUTE_ALLOC_SIZE(args) _GL_ATTRIBUTE_ALLOC_SIZE(args)
+#define ATTRIBUTE_ALWAYS_INLINE _GL_ATTRIBUTE_ALWAYS_INLINE
+#define ATTRIBUTE_ARTIFICIAL _GL_ATTRIBUTE_ARTIFICIAL
+#define ATTRIBUTE_COLD _GL_ATTRIBUTE_COLD
+#define ATTRIBUTE_CONST _GL_ATTRIBUTE_CONST
+#define ATTRIBUTE_DEPRECATED _GL_ATTRIBUTE_DEPRECATED
+#define ATTRIBUTE_ERROR(msg) _GL_ATTRIBUTE_ERROR(msg)
+#define ATTRIBUTE_EXTERNALLY_VISIBLE _GL_ATTRIBUTE_EXTERNALLY_VISIBLE
+#define ATTRIBUTE_FORMAT(spec) _GL_ATTRIBUTE_FORMAT(spec)
+#define ATTRIBUTE_LEAF _GL_ATTRIBUTE_LEAF
+#define ATTRIBUTE_MAY_ALIAS _GL_ATTRIBUTE_MAY_ALIAS
+#define ATTRIBUTE_MALLOC _GL_ATTRIBUTE_MALLOC
+#define ATTRIBUTE_NOINLINE _GL_ATTRIBUTE_NOINLINE
+#define ATTRIBUTE_NONNULL(args) _GL_ATTRIBUTE_NONNULL(args)
+#define ATTRIBUTE_NONSTRING _GL_ATTRIBUTE_NONSTRING
+#define ATTRIBUTE_NOTHROW _GL_ATTRIBUTE_NOTHROW
+#define ATTRIBUTE_PACKED _GL_ATTRIBUTE_PACKED
+#define ATTRIBUTE_PURE _GL_ATTRIBUTE_PURE
+#define ATTRIBUTE_RETURNS_NONNULL _GL_ATTRIBUTE_RETURNS_NONNULL
+#define ATTRIBUTE_SENTINEL(pos) _GL_ATTRIBUTE_SENTINEL(pos)
+#define ATTRIBUTE_WARNING(msg) _GL_ATTRIBUTE_WARNING(msg)
+
+#endif /* _GL_ATTRIBUTE_H */
diff --git a/lib/explicit_bzero.c b/lib/explicit_bzero.c
index c82771fb1e3..b1f5acb7771 100644
--- a/lib/explicit_bzero.c
+++ b/lib/explicit_bzero.c
@@ -25,8 +25,18 @@
 # include <config.h>
 #endif
 
+/* memset_s need this define */
+#if HAVE_MEMSET_S
+# define __STDC_WANT_LIB_EXT1__ 1
+#endif
+
 #include <string.h>
 
+#if defined _WIN32 && !defined __CYGWIN__
+# define  WIN32_LEAN_AND_MEAN
+# include <windows.h>
+#endif
+
 #if _LIBC
 /* glibc-internal users use __explicit_bzero_chk, and explicit_bzero
    redirects to that.  */
@@ -38,8 +48,12 @@
 void
 explicit_bzero (void *s, size_t len)
 {
-#ifdef HAVE_EXPLICIT_MEMSET
-  explicit_memset (s, 0, len);
+#if defined _WIN32 && !defined __CYGWIN__
+  (void) SecureZeroMemory (s, len);
+#elif HAVE_EXPLICIT_MEMSET
+  explicit_memset (s, '\0', len);
+#elif HAVE_MEMSET_S
+  (void) memset_s (s, len, '\0', len);
 #else
   memset (s, '\0', len);
 # if defined __GNUC__ && !defined __clang__
diff --git a/lib/gnulib.mk.in b/lib/gnulib.mk.in
index 0c7c2fb2b66..5c11dfc95ca 100644
--- a/lib/gnulib.mk.in
+++ b/lib/gnulib.mk.in
@@ -1122,6 +1122,7 @@ pdfdir = @pdfdir@
 prefix = @prefix@
 program_transform_name = @program_transform_name@
 psdir = @psdir@
+runstatedir = @runstatedir@
 sbindir = @sbindir@
 sharedstatedir = @sharedstatedir@
 srcdir = @srcdir@
@@ -1208,6 +1209,15 @@ endif
 endif
 ## end   gnulib module at-internal
 
+## begin gnulib module attribute
+ifeq (,$(OMIT_GNULIB_MODULE_attribute))
+
+
+EXTRA_DIST += attribute.h
+
+endif
+## end   gnulib module attribute
+
 ## begin gnulib module binary-io
 ifeq (,$(OMIT_GNULIB_MODULE_binary-io))
 
diff --git a/lib/ieee754.in.h b/lib/ieee754.in.h
index 01ca648905f..d64bb46e9de 100644
--- a/lib/ieee754.in.h
+++ b/lib/ieee754.in.h
@@ -67,7 +67,7 @@ union ieee754_float
 #endif                          /* Little endian.  */
       } ieee;
 
-    /* This format makes it easier to see if a NaN is a signaling NaN.  */
+    /* This format makes it easier to see if a NaN is a signalling NaN.  */
     struct
       {
 #if     __BYTE_ORDER == __BIG_ENDIAN
@@ -118,7 +118,7 @@ union ieee754_double
 #endif                          /* Little endian.  */
       } ieee;
 
-    /* This format makes it easier to see if a NaN is a signaling NaN.  */
+    /* This format makes it easier to see if a NaN is a signalling NaN.  */
     struct
       {
 #if     __BYTE_ORDER == __BIG_ENDIAN
diff --git a/lib/nstrftime.c b/lib/nstrftime.c
index fc5052a549c..28b539dc2f2 100644
--- a/lib/nstrftime.c
+++ b/lib/nstrftime.c
@@ -68,16 +68,9 @@ extern char *tzname[];
 #include <string.h>
 #include <stdbool.h>
 
+#include "attribute.h"
 #include <intprops.h>
 
-#ifndef FALLTHROUGH
-# if __GNUC__ < 7
-#  define FALLTHROUGH ((void) 0)
-# else
-#  define FALLTHROUGH __attribute__ ((__fallthrough__))
-# endif
-#endif
-
 #ifdef COMPILE_WIDE
 # include <endian.h>
 # define CHAR_T wchar_t