13 files changed, 326 insertions, 71 deletions

diff --git a/build-aux/config.guess b/build-aux/config.guess
index 45001cfecde..11fda528bc7 100755
--- a/build-aux/config.guess
+++ b/build-aux/config.guess
@@ -2,7 +2,7 @@
 # Attempt to guess a canonical system name.
 #   Copyright 1992-2020 Free Software Foundation, Inc.
 
-timestamp='2020-01-01'
+timestamp='2020-04-26'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@@ -1629,6 +1629,12 @@ copies of config.guess and config.sub with the latest versions from:
   https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess
 and
   https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub
+EOF
+
+year=`echo $timestamp | sed 's,-.*,,'`
+# shellcheck disable=SC2003
+if test "`expr "\`date +%Y\`" - "$year"`" -lt 3 ; then
+   cat >&2 <<EOF
 
 If $0 has already been updated, send the following data and any
 information you think might be pertinent to config-patches@gnu.org to
@@ -1656,6 +1662,7 @@ UNAME_RELEASE = "$UNAME_RELEASE"
 UNAME_SYSTEM  = "$UNAME_SYSTEM"
 UNAME_VERSION = "$UNAME_VERSION"
 EOF
+fi
 
 exit 1
 
diff --git a/build-aux/config.sub b/build-aux/config.sub
index f02d43ad500..a0d12275ac5 100755
--- a/build-aux/config.sub
+++ b/build-aux/config.sub
@@ -2,7 +2,7 @@
 # Configuration validation subroutine script.
 #   Copyright 1992-2020 Free Software Foundation, Inc.
 
-timestamp='2020-01-01'
+timestamp='2020-04-24'
 
 # This file is free software; you can redistribute it and/or modify it
 # under the terms of the GNU General Public License as published by
@@ -1366,7 +1366,7 @@ case $os in
              | skyos* | haiku* | rdos* | toppers* | drops* | es* \
              | onefs* | tirtos* | phoenix* | fuchsia* | redox* | bme* \
              | midnightbsd* | amdhsa* | unleashed* | emscripten* | wasi* \
-             | nsk* | powerunix)
+             | nsk* | powerunix*)
         # Remember, each alternative MUST END IN *, to match a version number.
                 ;;
         qnx*)
diff --git a/build-aux/gitlog-to-changelog b/build-aux/gitlog-to-changelog
index 511276757f5..be8082e7ffd 100755
--- a/build-aux/gitlog-to-changelog
+++ b/build-aux/gitlog-to-changelog
@@ -31,11 +31,11 @@
 # are valid code in both sh and perl.  When executed by sh, they re-execute
 # the script through the perl program found in $PATH.  The '-x' option
 # is essential as well; without it, perl would re-execute the script
-# through /bin/sh.  When executed by  perl, the next two lines are a no-op.
+# through /bin/sh.  When executed by perl, the next two lines are a no-op.
 eval 'exec perl -wSx "$0" "$@"'
      if 0;
 
-my $VERSION = '2018-03-07 03:47'; # UTC
+my $VERSION = '2020-04-04 15:07'; # UTC
 # The definition above must lie within the first 8 lines in order
 # for the Emacs time-stamp write hook (at end) to update it.
 # If you change this file with Emacs, please let the write hook
diff --git a/build-aux/update-copyright b/build-aux/update-copyright
index 4f79b56be78..d9b7f683a08 100755
--- a/build-aux/update-copyright
+++ b/build-aux/update-copyright
@@ -133,11 +133,11 @@
 # are valid code in both sh and perl.  When executed by sh, they re-execute
 # the script through the perl program found in $PATH.  The '-x' option
 # is essential as well; without it, perl would re-execute the script
-# through /bin/sh.  When executed by  perl, the next two lines are a no-op.
+# through /bin/sh.  When executed by perl, the next two lines are a no-op.
 eval 'exec perl -wSx -0777 -pi "$0" "$@"'
      if 0;
 
-my $VERSION = '2018-03-07.03:47'; # UTC
+my $VERSION = '2020-04-04.15:07'; # UTC
 # The definition above must lie within the first 8 lines in order
 # for the Emacs time-stamp write hook (at end) to update it.
 # If you change this file with Emacs, please let the write hook
diff --git a/doc/misc/texinfo.tex b/doc/misc/texinfo.tex
index deca5991870..427494cbbfc 100644
--- a/doc/misc/texinfo.tex
+++ b/doc/misc/texinfo.tex
@@ -3,7 +3,7 @@
 % Load plain if necessary, i.e., if running under initex.
 \expandafter\ifx\csname fmtname\endcsname\relax\input plain\fi
 %
-\def\texinfoversion{2020-02-11.09}
+\def\texinfoversion{2020-05-02.00}
 %
 % Copyright 1985, 1986, 1988, 1990-2019 Free Software Foundation, Inc.
 %
@@ -349,34 +349,19 @@
   \ifodd\pageno  \advance\hoffset by \bindingoffset
   \else \advance\hoffset by -\bindingoffset\fi
   %
+  \checkchapterpage
+  %
   % Retrieve the information for the headings from the marks in the page,
   % and call Plain TeX's \makeheadline and \makefootline, which use the
   % values in \headline and \footline.
   %
-  % This is used to check if we are on the first page of a chapter.
-  \ifcase1\the\savedtopmark\fi
-  \let\prevchaptername\thischaptername
-  \ifcase0\firstmark\fi
-  \let\curchaptername\thischaptername
-  %
-  \ifodd\pageno \getoddheadingmarks \else \getevenheadingmarks \fi
-  %
-  \ifx\curchaptername\prevchaptername
-    \let\thischapterheading\thischapter
-  \else
-    % \thischapterheading is the same as \thischapter except it is blank
-    % for the first page of a chapter.  This is to prevent the chapter name
-    % being shown twice.
-    \def\thischapterheading{}%
-  \fi
-  %
   % Common context changes for both heading and footing.
   % Do this outside of the \shipout so @code etc. will be expanded in
   % the headline as they should be, not taken literally (outputting ''code).
   \def\commonheadfootline{\let\hsize=\txipagewidth \texinfochars}
   %
+  \ifodd\pageno \getoddheadingmarks \else \getevenheadingmarks \fi
   \global\setbox\headlinebox = \vbox{\commonheadfootline \makeheadline}%
-  %
   \ifodd\pageno \getoddfootingmarks \else \getevenfootingmarks \fi
   \global\setbox\footlinebox = \vbox{\commonheadfootline \makefootline}%
   %
@@ -423,6 +408,24 @@
 \ifr@ggedbottom \kern-\dimen@ \vfil \fi}
 }
 
+% Check if we are on the first page of a chapter.
+\def\checkchapterpage{%
+  % Get the chapter that was current at the end of the last page
+  \ifcase1\the\savedtopmark\fi
+  \let\prevchaptername\thischaptername
+  %
+  \ifodd\pageno \getoddheadingmarks \else \getevenheadingmarks \fi
+  \let\curchaptername\thischaptername
+  %
+  \ifx\curchaptername\prevchaptername
+    \let\thischapterheading\thischapter
+  \else
+    % \thischapterheading is the same as \thischapter except it is blank
+    % for the first page of a chapter.  This is to prevent the chapter name
+    % being shown twice.
+    \def\thischapterheading{}%
+  \fi
+}
 
 % Argument parsing
 
@@ -3101,10 +3104,10 @@ end
 
 % Allow a ragged right output to aid breaking long URL's.  There can
 % be a break at the \allowbreak with no extra glue (if the existing stretch in
-% the line is sufficent), a break at the \penalty100 with extra glue added
+% the line is sufficient), a break at the \penalty100 with extra glue added
 % at the end of the line, or no break at all here.
 %   Changing the value of the penalty and/or the amount of stretch affects how
-% preferrable one choice is over the other.
+% preferable one choice is over the other.
 \def\urefallowbreak{%
   \allowbreak
   \hskip 0pt plus 2 em\relax
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
diff --git a/m4/explicit_bzero.m4 b/m4/explicit_bzero.m4
index 507816affdb..a415e7b4f5e 100644
--- a/m4/explicit_bzero.m4
+++ b/m4/explicit_bzero.m4
@@ -19,4 +19,5 @@ AC_DEFUN([gl_FUNC_EXPLICIT_BZERO],
 AC_DEFUN([gl_PREREQ_EXPLICIT_BZERO],
 [
   AC_CHECK_FUNCS([explicit_memset])
+  AC_CHECK_FUNCS_ONCE([memset_s])
 ])
diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4
index b4795c18aeb..b0010d0e351 100644
--- a/m4/gnulib-common.m4
+++ b/m4/gnulib-common.m4
@@ -1,4 +1,4 @@
-# gnulib-common.m4 serial 48
+# gnulib-common.m4 serial 49
 dnl Copyright (C) 2007-2020 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -15,6 +15,15 @@ AC_DEFUN([gl_COMMON], [
   AC_REQUIRE([gl_ZZGNULIB])
 ])
 AC_DEFUN([gl_COMMON_BODY], [
+  AH_VERBATIM([_GL_GNUC_PREREQ],
+[/* True if the compiler says it groks GNU C version MAJOR.MINOR.  */
+#if defined __GNUC__ && defined __GNUC_MINOR__
+# define _GL_GNUC_PREREQ(major, minor) \
+    ((major) < __GNUC__ + ((minor) <= __GNUC_MINOR__))
+#else
+# define _GL_GNUC_PREREQ(major, minor) 0
+#endif
+])
   AH_VERBATIM([_Noreturn],
 [/* The _Noreturn keyword of C11.  */
 #ifndef _Noreturn
@@ -31,12 +40,12 @@ AC_DEFUN([gl_COMMON_BODY], [
 #  define _Noreturn [[noreturn]]
 # elif ((!defined __cplusplus || defined __clang__) \
         && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0)  \
-            || 4 < __GNUC__ + (7 <= __GNUC_MINOR__) \
+            || _GL_GNUC_PREREQ (4, 7) \
             || (defined __apple_build_version__ \
                 ? 6000000 <= __apple_build_version__ \
                 : 3 < __clang_major__ + (5 <= __clang_minor__))))
    /* _Noreturn works as-is.  */
-# elif 2 < __GNUC__ + (8 <= __GNUC_MINOR__) || 0x5110 <= __SUNPRO_C
+# elif _GL_GNUC_PREREQ (2, 8) || 0x5110 <= __SUNPRO_C
 #  define _Noreturn __attribute__ ((__noreturn__))
 # elif 1200 <= (defined _MSC_VER ? _MSC_VER : 0)
 #  define _Noreturn __declspec (noreturn)
@@ -55,48 +64,206 @@ AC_DEFUN([gl_COMMON_BODY], [
 #if defined __APPLE__ && defined __MACH__ && __APPLE_CC__ >= 5465 && !defined __cplusplus && __STDC_VERSION__ >= 199901L && !defined __GNUC_STDC_INLINE__
 # define __GNUC_STDC_INLINE__ 1
 #endif])
-  AH_VERBATIM([unused_parameter],
-[/* Define as a marker that can be attached to declarations that might not
-    be used.  This helps to reduce warnings, such as from
-    GCC -Wunused-parameter.  */
-#if __GNUC__ >= 3 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 7)
-# define _GL_UNUSED __attribute__ ((__unused__))
+  AH_VERBATIM([attribute],
+[/* Attributes.  */
+#ifdef __has_attribute
+# define _GL_HAS_ATTRIBUTE(attr) __has_attribute (__##attr##__)
 #else
-# define _GL_UNUSED
+# define _GL_HAS_ATTRIBUTE(attr) _GL_ATTR_##attr
+# define _GL_ATTR_alloc_size _GL_GNUC_PREREQ (4, 3)
+# define _GL_ATTR_always_inline _GL_GNUC_PREREQ (3, 2)
+# define _GL_ATTR_artificial _GL_GNUC_PREREQ (4, 3)
+# define _GL_ATTR_cold _GL_GNUC_PREREQ (4, 3)
+# define _GL_ATTR_const _GL_GNUC_PREREQ (2, 95)
+# define _GL_ATTR_deprecated _GL_GNUC_PREREQ (3, 1)
+# define _GL_ATTR_error _GL_GNUC_PREREQ (4, 3)
+# define _GL_ATTR_externally_visible _GL_GNUC_PREREQ (4, 1)
+# define _GL_ATTR_fallthrough _GL_GNUC_PREREQ (7, 0)
+# define _GL_ATTR_format _GL_GNUC_PREREQ (2, 7)
+# define _GL_ATTR_leaf _GL_GNUC_PREREQ (4, 6)
+# ifdef _ICC
+#  define _GL_ATTR_may_alias 0
+# else
+#  define _GL_ATTR_may_alias _GL_GNUC_PREREQ (3, 3)
+# endif
+# define _GL_ATTR_malloc _GL_GNUC_PREREQ (3, 0)
+# define _GL_ATTR_noinline _GL_GNUC_PREREQ (3, 1)
+# define _GL_ATTR_nonnull _GL_GNUC_PREREQ (3, 3)
+# define _GL_ATTR_nonstring _GL_GNUC_PREREQ (8, 0)
+# define _GL_ATTR_nothrow _GL_GNUC_PREREQ (3, 3)
+# define _GL_ATTR_packed _GL_GNUC_PREREQ (2, 7)
+# define _GL_ATTR_pure _GL_GNUC_PREREQ (2, 96)
+# define _GL_ATTR_returns_nonnull _GL_GNUC_PREREQ (4, 9)
+# define _GL_ATTR_sentinel _GL_GNUC_PREREQ (4, 0)
+# define _GL_ATTR_unused _GL_GNUC_PREREQ (2, 7)
+# define _GL_ATTR_warn_unused_result_GL_GNUC_PREREQ (3, 4)
 #endif
-/* The name _UNUSED_PARAMETER_ is an earlier spelling, although the name
-   is a misnomer outside of parameter lists.  */
-#define _UNUSED_PARAMETER_ _GL_UNUSED
-
-/* gcc supports the "unused" attribute on possibly unused labels, and
-   g++ has since version 4.5.  Note to support C++ as well as C,
-   _GL_UNUSED_LABEL should be used with a trailing ;  */
-#if !defined __cplusplus || __GNUC__ > 4 \
-    || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
-# define _GL_UNUSED_LABEL _GL_UNUSED
+
+]dnl There is no _GL_ATTRIBUTE_ALIGNED; use stdalign's _Alignas instead.
+[
+#if _GL_HAS_ATTRIBUTE (alloc_size)
+# define _GL_ATTRIBUTE_ALLOC_SIZE(args) __attribute__ ((__alloc_size__ args))
 #else
-# define _GL_UNUSED_LABEL
+# define _GL_ATTRIBUTE_ALLOC_SIZE(args)
 #endif
 
-/* The __pure__ attribute was added in gcc 2.96.  */
-#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
-# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
+#if _GL_HAS_ATTRIBUTE (always_inline)
+# define _GL_ATTRIBUTE_ALWAYS_INLINE __attribute__ ((__always_inline__))
 #else
-# define _GL_ATTRIBUTE_PURE /* empty */
+# define _GL_ATTRIBUTE_ALWAYS_INLINE
 #endif
 
-/* The __const__ attribute was added in gcc 2.95.  */
-#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95)
+#if _GL_HAS_ATTRIBUTE (artificial)
+# define _GL_ATTRIBUTE_ARTIFICIAL __attribute__ ((__artificial__))
+#else
+# define _GL_ATTRIBUTE_ARTIFICIAL
+#endif
+
+/* Avoid __attribute__ ((cold)) on MinGW; see thread starting at
+   <https://lists.gnu.org/r/emacs-devel/2019-04/msg01152.html>. */
+#if _GL_HAS_ATTRIBUTE (cold) && !defined __MINGW32__
+# define _GL_ATTRIBUTE_COLD __attribute__ ((cold))
+#else
+# define _GL_ATTRIBUTE_COLD
+#endif
+
+#if _GL_HAS_ATTRIBUTE (const)
 # define _GL_ATTRIBUTE_CONST __attribute__ ((__const__))
 #else
-# define _GL_ATTRIBUTE_CONST /* empty */
+# define _GL_ATTRIBUTE_CONST
 #endif
 
-/* The __malloc__ attribute was added in gcc 3.  */
-#if 3 <= __GNUC__
+#if 201710L < __STDC_VERSION__
+# define _GL_ATTRIBUTE_DEPRECATED [[__deprecated__]]
+#elif _GL_HAS_ATTRIBUTE (deprecated)
+# define _GL_ATTRIBUTE_DEPRECATED __attribute__ ((__deprecated__))
+#else
+# define _GL_ATTRIBUTE_DEPRECATED
+#endif
+
+#if _GL_HAS_ATTRIBUTE (error)
+# define _GL_ATTRIBUTE_ERROR(msg) __attribute__((__error__ (msg)))
+# define _GL_ATTRIBUTE_WARNING(msg) __attribute__((__warning__ (msg)))
+#else
+# define _GL_ATTRIBUTE_ERROR(msg)
+# define _GL_ATTRIBUTE_WARNING(msg)
+#endif
+
+#if _GL_HAS_ATTRIBUTE (externally_visible)
+# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE __attribute__ ((externally_visible))
+#else
+# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE
+#endif
+
+/* FALLTHROUGH is special, because it always expands to something.  */
+#if 201710L < __STDC_VERSION__
+# define _GL_ATTRIBUTE_FALLTHROUGH [[__fallthrough__]]
+#elif _GL_HAS_ATTRIBUTE (fallthrough)
+# define _GL_ATTRIBUTE_FALLTHROUGH __attribute__ ((__fallthrough__))
+#else
+# define _GL_ATTRIBUTE_FALLTHROUGH ((void) 0)
+#endif
+
+#if _GL_HAS_ATTRIBUTE (format)
+# define _GL_ATTRIBUTE_FORMAT(spec) __attribute__ ((__format__ spec))
+#else
+# define _GL_ATTRIBUTE_FORMAT(spec)
+#endif
+
+#if _GL_HAS_ATTRIBUTE (leaf)
+# define _GL_ATTRIBUTE_LEAF __attribute__ ((__leaf__))
+#else
+# define _GL_ATTRIBUTE_LEAF
+#endif
+
+#if _GL_HAS_ATTRIBUTE (may_alias)
+# define _GL_ATTRIBUTE_MAY_ALIAS __attribute__ ((__may_alias__))
+#else
+# define _GL_ATTRIBUTE_MAY_ALIAS
+#endif
+
+#if 201710L < __STDC_VERSION__
+# define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]]
+#elif _GL_HAS_ATTRIBUTE (unused)
+# define _GL_ATTRIBUTE_MAYBE_UNUSED __attribute__ ((__unused__))
+#else
+# define _GL_ATTRIBUTE_MAYBE_UNUSED
+#endif
+/* Earlier spellings of this macro.  */
+#define _GL_UNUSED _GL_ATTRIBUTE_MAYBE_UNUSED
+#define _UNUSED_PARAMETER_ _GL_ATTRIBUTE_MAYBE_UNUSED
+
+#if _GL_HAS_ATTRIBUTE (malloc)
 # define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
 #else
-# define _GL_ATTRIBUTE_MALLOC /* empty */
+# define _GL_ATTRIBUTE_MALLOC
+#endif
+
+#if 201710L < __STDC_VERSION__
+# define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]]
+#elif _GL_HAS_ATTRIBUTE (warn_unused_result)
+# define _GL_ATTRIBUTE_NODISCARD __attribute__ ((__warn_unused_result__))
+#else
+# define _GL_ATTRIBUTE_NODISCARD
+#endif
+
+#if _GL_HAS_ATTRIBUTE (noinline)
+# define _GL_ATTRIBUTE_NOINLINE __attribute__ ((__noinline__))
+#else
+# define _GL_ATTRIBUTE_NOINLINE
+#endif
+
+#if _GL_HAS_ATTRIBUTE (nonnull)
+# define _GL_ATTRIBUTE_NONNULL(args) __attribute__ ((__nonnull__ args))
+#else
+# define _GL_ATTRIBUTE_NONNULL(args)
+#endif
+
+#if _GL_HAS_ATTRIBUTE (nonstring)
+# define _GL_ATTRIBUTE_NONSTRING __attribute__ ((__nonstring__))
+#else
+# define _GL_ATTRIBUTE_NONSTRING
+#endif
+
+/* There is no _GL_ATTRIBUTE_NORETURN; use _Noreturn instead.  */
+
+#if _GL_HAS_ATTRIBUTE (nothrow) && !defined __cplusplus
+# define _GL_ATTRIBUTE_NOTHROW __attribute__ ((__nothrow__))
+#else
+# define _GL_ATTRIBUTE_NOTHROW
+#endif
+
+#if _GL_HAS_ATTRIBUTE (packed)
+# define _GL_ATTRIBUTE_PACKED __attribute__ ((__packed__))
+#else
+# define _GL_ATTRIBUTE_PACKED
+#endif
+
+#if _GL_HAS_ATTRIBUTE (pure)
+# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
+#else
+# define _GL_ATTRIBUTE_PURE
+#endif
+
+#if _GL_HAS_ATTRIBUTE (returns_nonnull)
+# define _GL_ATTRIBUTE_RETURNS_NONNULL __attribute__ ((__returns_nonnull__))
+#else
+# define _GL_ATTRIBUTE_RETURNS_NONNULL
+#endif
+
+#if _GL_HAS_ATTRIBUTE (sentinel)
+# define _GL_ATTRIBUTE_SENTINEL(pos) __attribute__ ((__sentinel__ pos))
+#else
+# define _GL_ATTRIBUTE_SENTINEL(pos)
+#endif
+
+]dnl There is no _GL_ATTRIBUTE_VISIBILITY; see m4/visibility.m4 instead.
+[
+/* To support C++ as well as C, use _GL_UNUSED_LABEL with trailing ';'.  */
+#if !defined __cplusplus || _GL_GNUC_PREREQ (4, 5)
+# define _GL_UNUSED_LABEL _GL_ATTRIBUTE_MAYBE_UNUSED
+#else
+# define _GL_UNUSED_LABEL
 #endif
 ])
   AH_VERBATIM([async_safe],
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index d5faa9a1950..37170247884 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -47,6 +47,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module alloca-opt:
   # Code from module allocator:
   # Code from module at-internal:
+  # Code from module attribute:
   # Code from module binary-io:
   # Code from module builtin-expect:
   # Code from module byteswap:
@@ -934,6 +935,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/allocator.h
   lib/arg-nonnull.h
   lib/at-func.c
+  lib/attribute.h
   lib/binary-io.c
   lib/binary-io.h
   lib/byteswap.in.h