Merge tag 'upstream/4.14' into tizentizen_6.5.m2_releasetizen_6.0.m2_releasetizen_5.5.m2_releasesubmit/tizen_6.5/20211028.163501submit/tizen_6.0_hotfix/20201103.115102submit/tizen_6.0_hotfix/20201102.192902submit/tizen_6.0/20201029.205502submit/tizen_5.5_wearable_hotfix/20201026.184307submit/tizen_5.5_mobile_hotfix/20201026.185107submit/tizen_5.5/20191031.000007submit/tizen/20190904.070216submit/tizen/20190829.061506accepted/tizen/unified/20190904.110630accepted/tizen/6.5/unified/20211029.014057accepted/tizen/6.0/unified/hotfix/20201103.050702accepted/tizen/6.0/unified/hotfix/20201102.234932accepted/tizen/6.0/unified/20201030.110146accepted/tizen/5.5/unified/wearable/hotfix/20201027.100357accepted/tizen/5.5/unified/mobile/hotfix/20201027.074057accepted/tizen/5.5/unified/20191031.011500tizen_6.5tizen_6.0_hotfixtizen_6.0tizen_5.5_wearable_hotfixtizen_5.5_tvtizen_5.5_mobile_hotfixtizen_5.5accepted/tizen_6.5_unifiedaccepted/tizen_6.0_unified_hotfixaccepted/tizen_6.0_unifiedaccepted/tizen_5.5_unified_wearable_hotfixaccepted/tizen_5.5_unified_mobile_hotfixaccepted/tizen_5.5_unified

Change-Id: I6d4b47b2072db8e7c45daa6e269e2f0cc6f54a7f

25 files changed, 2862 insertions, 0 deletions

diff --git a/m4-gl/00gnulib.m4 b/m4-gl/00gnulib.m4
new file mode 100644
index 0000000..e3e0fb6
--- /dev/null
+++ b/m4-gl/00gnulib.m4
@@ -0,0 +1,46 @@
+# 00gnulib.m4 serial 3
+dnl Copyright (C) 2009-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl This file must be named something that sorts before all other
+dnl gnulib-provided .m4 files.  It is needed until such time as we can
+dnl assume Autoconf 2.64, with its improved AC_DEFUN_ONCE and
+dnl m4_divert semantics.
+
+# Until autoconf 2.63, handling of the diversion stack required m4_init
+# to be called first; but this does not happen with aclocal.  Wrapping
+# the entire execution in another layer of the diversion stack fixes this.
+# Worse, prior to autoconf 2.62, m4_wrap depended on the underlying m4
+# for whether it was FIFO or LIFO; in order to properly balance with
+# m4_init, we need to undo our push just before anything wrapped within
+# the m4_init body.  The way to ensure this is to wrap both sides of
+# m4_init with a one-shot macro that does the pop at the right time.
+m4_ifndef([_m4_divert_diversion],
+[m4_divert_push([KILL])
+m4_define([gl_divert_fixup], [m4_divert_pop()m4_define([$0])])
+m4_define([m4_init],
+  [gl_divert_fixup()]m4_defn([m4_init])[gl_divert_fixup()])])
+
+
+# AC_DEFUN_ONCE([NAME], VALUE)
+# ----------------------------
+# Define NAME to expand to VALUE on the first use (whether by direct
+# expansion, or by AC_REQUIRE), and to nothing on all subsequent uses.
+# Avoid bugs in AC_REQUIRE in Autoconf 2.63 and earlier.  This
+# definition is slower than the version in Autoconf 2.64, because it
+# can only use interfaces that existed since 2.59; but it achieves the
+# same effect.  Quoting is necessary to avoid confusing Automake.
+m4_version_prereq([2.63.263], [],
+[m4_define([AC][_DEFUN_ONCE],
+  [AC][_DEFUN([$1],
+    [AC_REQUIRE([_gl_DEFUN_ONCE([$1])],
+      [m4_indir([_gl_DEFUN_ONCE([$1])])])])]dnl
+[AC][_DEFUN([_gl_DEFUN_ONCE([$1])], [$2])])])
+
+# gl_00GNULIB
+# -----------
+# Witness macro that this file has been included.  Needed to force
+# Automake to include this file prior to all other gnulib .m4 files.
+AC_DEFUN([gl_00GNULIB])
diff --git a/m4-gl/__inline.m4 b/m4-gl/__inline.m4
new file mode 100644
index 0000000..e1aa310
--- /dev/null
+++ b/m4-gl/__inline.m4
@@ -0,0 +1,22 @@
+# Test for __inline keyword
+dnl Copyright 2017-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl___INLINE],
+[
+  AC_CACHE_CHECK([whether the compiler supports the __inline keyword],
+    [gl_cv_c___inline],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+         [[typedef int foo_t;
+           static __inline foo_t foo (void) { return 0; }]],
+         [[return foo ();]])],
+       [gl_cv_c___inline=yes],
+       [gl_cv_c___inline=no])])
+  if test $gl_cv_c___inline = yes; then
+    AC_DEFINE([HAVE___INLINE], [1],
+      [Define to 1 if the compiler supports the keyword '__inline'.])
+  fi
+])
diff --git a/m4-gl/absolute-header.m4 b/m4-gl/absolute-header.m4
new file mode 100644
index 0000000..a8f2cba
--- /dev/null
+++ b/m4-gl/absolute-header.m4
@@ -0,0 +1,102 @@
+# absolute-header.m4 serial 16
+dnl Copyright (C) 2006-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Derek Price.
+
+# gl_ABSOLUTE_HEADER(HEADER1 HEADER2 ...)
+# ---------------------------------------
+# Find the absolute name of a header file, testing first if the header exists.
+# If the header were sys/inttypes.h, this macro would define
+# ABSOLUTE_SYS_INTTYPES_H to the '""' quoted absolute name of sys/inttypes.h
+# in config.h
+# (e.g. '#define ABSOLUTE_SYS_INTTYPES_H "///usr/include/sys/inttypes.h"').
+# The three "///" are to pacify Sun C 5.8, which otherwise would say
+# "warning: #include of /usr/include/... may be non-portable".
+# Use '""', not '<>', so that the /// cannot be confused with a C99 comment.
+# Note: This macro assumes that the header file is not empty after
+# preprocessing, i.e. it does not only define preprocessor macros but also
+# provides some type/enum definitions or function/variable declarations.
+AC_DEFUN([gl_ABSOLUTE_HEADER],
+[AC_REQUIRE([AC_CANONICAL_HOST])
+AC_LANG_PREPROC_REQUIRE()dnl
+dnl FIXME: gl_absolute_header and ac_header_exists must be used unquoted
+dnl until we can assume autoconf 2.64 or newer.
+m4_foreach_w([gl_HEADER_NAME], [$1],
+  [AS_VAR_PUSHDEF([gl_absolute_header],
+                  [gl_cv_absolute_]m4_defn([gl_HEADER_NAME]))dnl
+  AC_CACHE_CHECK([absolute name of <]m4_defn([gl_HEADER_NAME])[>],
+    m4_defn([gl_absolute_header]),
+    [AS_VAR_PUSHDEF([ac_header_exists],
+                    [ac_cv_header_]m4_defn([gl_HEADER_NAME]))dnl
+    AC_CHECK_HEADERS_ONCE(m4_defn([gl_HEADER_NAME]))dnl
+    if test AS_VAR_GET(ac_header_exists) = yes; then
+      gl_ABSOLUTE_HEADER_ONE(m4_defn([gl_HEADER_NAME]))
+    fi
+    AS_VAR_POPDEF([ac_header_exists])dnl
+    ])dnl
+  AC_DEFINE_UNQUOTED(AS_TR_CPP([ABSOLUTE_]m4_defn([gl_HEADER_NAME])),
+                     ["AS_VAR_GET(gl_absolute_header)"],
+                     [Define this to an absolute name of <]m4_defn([gl_HEADER_NAME])[>.])
+  AS_VAR_POPDEF([gl_absolute_header])dnl
+])dnl
+])# gl_ABSOLUTE_HEADER
+
+# gl_ABSOLUTE_HEADER_ONE(HEADER)
+# ------------------------------
+# Like gl_ABSOLUTE_HEADER, except that:
+#   - it assumes that the header exists,
+#   - it uses the current CPPFLAGS,
+#   - it does not cache the result,
+#   - it is silent.
+AC_DEFUN([gl_ABSOLUTE_HEADER_ONE],
+[
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_LANG_CONFTEST([AC_LANG_SOURCE([[#include <]]m4_dquote([$1])[[>]])])
+  dnl AIX "xlc -E" and "cc -E" omit #line directives for header files
+  dnl that contain only a #include of other header files and no
+  dnl non-comment tokens of their own. This leads to a failure to
+  dnl detect the absolute name of <dirent.h>, <signal.h>, <poll.h>
+  dnl and others. The workaround is to force preservation of comments
+  dnl through option -C. This ensures all necessary #line directives
+  dnl are present. GCC supports option -C as well.
+  case "$host_os" in
+    aix*) gl_absname_cpp="$ac_cpp -C" ;;
+    *)    gl_absname_cpp="$ac_cpp" ;;
+  esac
+changequote(,)
+  case "$host_os" in
+    mingw*)
+      dnl For the sake of native Windows compilers (excluding gcc),
+      dnl treat backslash as a directory separator, like /.
+      dnl Actually, these compilers use a double-backslash as
+      dnl directory separator, inside the
+      dnl   # line "filename"
+      dnl directives.
+      gl_dirsep_regex='[/\\]'
+      ;;
+    *)
+      gl_dirsep_regex='\/'
+      ;;
+  esac
+  dnl A sed expression that turns a string into a basic regular
+  dnl expression, for use within "/.../".
+  gl_make_literal_regex_sed='s,[]$^\\.*/[],\\&,g'
+  gl_header_literal_regex=`echo '$1' \
+                           | sed -e "$gl_make_literal_regex_sed"`
+  gl_absolute_header_sed="/${gl_dirsep_regex}${gl_header_literal_regex}/"'{
+      s/.*"\(.*'"${gl_dirsep_regex}${gl_header_literal_regex}"'\)".*/\1/
+      s|^/[^/]|//&|
+      p
+      q
+    }'
+changequote([,])
+  dnl eval is necessary to expand gl_absname_cpp.
+  dnl Ultrix and Pyramid sh refuse to redirect output of eval,
+  dnl so use subshell.
+  AS_VAR_SET([gl_cv_absolute_]AS_TR_SH([[$1]]),
+[`(eval "$gl_absname_cpp conftest.$ac_ext") 2>&AS_MESSAGE_LOG_FD |
+  sed -n "$gl_absolute_header_sed"`])
+])
diff --git a/m4-gl/extensions.m4 b/m4-gl/extensions.m4
new file mode 100644
index 0000000..fd1ce81
--- /dev/null
+++ b/m4-gl/extensions.m4
@@ -0,0 +1,189 @@
+# serial 18  -*- Autoconf -*-
+# Enable extensions on systems that normally disable them.
+
+# Copyright (C) 2003, 2006-2019 Free Software Foundation, Inc.
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# This definition of AC_USE_SYSTEM_EXTENSIONS is stolen from git
+# Autoconf.  Perhaps we can remove this once we can assume Autoconf
+# 2.70 or later everywhere, but since Autoconf mutates rapidly
+# enough in this area it's likely we'll need to redefine
+# AC_USE_SYSTEM_EXTENSIONS for quite some time.
+
+# If autoconf reports a warning
+#     warning: AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS
+# or  warning: AC_RUN_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS
+# the fix is
+#   1) to ensure that AC_USE_SYSTEM_EXTENSIONS is never directly invoked
+#      but always AC_REQUIREd,
+#   2) to ensure that for each occurrence of
+#        AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+#      or
+#        AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+#      the corresponding gnulib module description has 'extensions' among
+#      its dependencies. This will ensure that the gl_USE_SYSTEM_EXTENSIONS
+#      invocation occurs in gl_EARLY, not in gl_INIT.
+
+# AC_USE_SYSTEM_EXTENSIONS
+# ------------------------
+# Enable extensions on systems that normally disable them,
+# typically due to standards-conformance issues.
+#
+# Remember that #undef in AH_VERBATIM gets replaced with #define by
+# AC_DEFINE.  The goal here is to define all known feature-enabling
+# macros, then, if reports of conflicts are made, disable macros that
+# cause problems on some platforms (such as __EXTENSIONS__).
+AC_DEFUN_ONCE([AC_USE_SYSTEM_EXTENSIONS],
+[AC_BEFORE([$0], [AC_COMPILE_IFELSE])dnl
+AC_BEFORE([$0], [AC_RUN_IFELSE])dnl
+
+  AC_CHECK_HEADER([minix/config.h], [MINIX=yes], [MINIX=])
+  if test "$MINIX" = yes; then
+    AC_DEFINE([_POSIX_SOURCE], [1],
+      [Define to 1 if you need to in order for 'stat' and other
+       things to work.])
+    AC_DEFINE([_POSIX_1_SOURCE], [2],
+      [Define to 2 if the system does not provide POSIX.1 features
+       except with this defined.])
+    AC_DEFINE([_MINIX], [1],
+      [Define to 1 if on MINIX.])
+    AC_DEFINE([_NETBSD_SOURCE], [1],
+      [Define to 1 to make NetBSD features available.  MINIX 3 needs this.])
+  fi
+
+dnl Use a different key than __EXTENSIONS__, as that name broke existing
+dnl configure.ac when using autoheader 2.62.
+  AH_VERBATIM([USE_SYSTEM_EXTENSIONS],
+[/* Enable extensions on AIX 3, Interix.  */
+#ifndef _ALL_SOURCE
+# undef _ALL_SOURCE
+#endif
+/* Enable general extensions on macOS.  */
+#ifndef _DARWIN_C_SOURCE
+# undef _DARWIN_C_SOURCE
+#endif
+/* Enable GNU extensions on systems that have them.  */
+#ifndef _GNU_SOURCE
+# undef _GNU_SOURCE
+#endif
+/* Enable NetBSD extensions on NetBSD.  */
+#ifndef _NETBSD_SOURCE
+# undef _NETBSD_SOURCE
+#endif
+/* Enable OpenBSD extensions on NetBSD.  */
+#ifndef _OPENBSD_SOURCE
+# undef _OPENBSD_SOURCE
+#endif
+/* Enable threading extensions on Solaris.  */
+#ifndef _POSIX_PTHREAD_SEMANTICS
+# undef _POSIX_PTHREAD_SEMANTICS
+#endif
+/* Enable extensions specified by ISO/IEC TS 18661-5:2014.  */
+#ifndef __STDC_WANT_IEC_60559_ATTRIBS_EXT__
+# undef __STDC_WANT_IEC_60559_ATTRIBS_EXT__
+#endif
+/* Enable extensions specified by ISO/IEC TS 18661-1:2014.  */
+#ifndef __STDC_WANT_IEC_60559_BFP_EXT__
+# undef __STDC_WANT_IEC_60559_BFP_EXT__
+#endif
+/* Enable extensions specified by ISO/IEC TS 18661-2:2015.  */
+#ifndef __STDC_WANT_IEC_60559_DFP_EXT__
+# undef __STDC_WANT_IEC_60559_DFP_EXT__
+#endif
+/* Enable extensions specified by ISO/IEC TS 18661-4:2015.  */
+#ifndef __STDC_WANT_IEC_60559_FUNCS_EXT__
+# undef __STDC_WANT_IEC_60559_FUNCS_EXT__
+#endif
+/* Enable extensions specified by ISO/IEC TS 18661-3:2015.  */
+#ifndef __STDC_WANT_IEC_60559_TYPES_EXT__
+# undef __STDC_WANT_IEC_60559_TYPES_EXT__
+#endif
+/* Enable extensions specified by ISO/IEC TR 24731-2:2010.  */
+#ifndef __STDC_WANT_LIB_EXT2__
+# undef __STDC_WANT_LIB_EXT2__
+#endif
+/* Enable extensions specified by ISO/IEC 24747:2009.  */
+#ifndef __STDC_WANT_MATH_SPEC_FUNCS__
+# undef __STDC_WANT_MATH_SPEC_FUNCS__
+#endif
+/* Enable extensions on HP NonStop.  */
+#ifndef _TANDEM_SOURCE
+# undef _TANDEM_SOURCE
+#endif
+/* Enable X/Open extensions if necessary.  HP-UX 11.11 defines
+   mbstate_t only if _XOPEN_SOURCE is defined to 500, regardless of
+   whether compiling with -Ae or -D_HPUX_SOURCE=1.  */
+#ifndef _XOPEN_SOURCE
+# undef _XOPEN_SOURCE
+#endif
+/* Enable X/Open compliant socket functions that do not require linking
+   with -lxnet on HP-UX 11.11.  */
+#ifndef _HPUX_ALT_XOPEN_SOCKET_API
+# undef _HPUX_ALT_XOPEN_SOCKET_API
+#endif
+/* Enable general extensions on Solaris.  */
+#ifndef __EXTENSIONS__
+# undef __EXTENSIONS__
+#endif
+])
+  AC_CACHE_CHECK([whether it is safe to define __EXTENSIONS__],
+    [ac_cv_safe_to_define___extensions__],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM([[
+#         define __EXTENSIONS__ 1
+          ]AC_INCLUDES_DEFAULT])],
+       [ac_cv_safe_to_define___extensions__=yes],
+       [ac_cv_safe_to_define___extensions__=no])])
+  test $ac_cv_safe_to_define___extensions__ = yes &&
+    AC_DEFINE([__EXTENSIONS__])
+  AC_DEFINE([_ALL_SOURCE])
+  AC_DEFINE([_DARWIN_C_SOURCE])
+  AC_DEFINE([_GNU_SOURCE])
+  AC_DEFINE([_NETBSD_SOURCE])
+  AC_DEFINE([_OPENBSD_SOURCE])
+  AC_DEFINE([_POSIX_PTHREAD_SEMANTICS])
+  AC_DEFINE([__STDC_WANT_IEC_60559_ATTRIBS_EXT__])
+  AC_DEFINE([__STDC_WANT_IEC_60559_BFP_EXT__])
+  AC_DEFINE([__STDC_WANT_IEC_60559_DFP_EXT__])
+  AC_DEFINE([__STDC_WANT_IEC_60559_FUNCS_EXT__])
+  AC_DEFINE([__STDC_WANT_IEC_60559_TYPES_EXT__])
+  AC_DEFINE([__STDC_WANT_LIB_EXT2__])
+  AC_DEFINE([__STDC_WANT_MATH_SPEC_FUNCS__])
+  AC_DEFINE([_TANDEM_SOURCE])
+  AC_CACHE_CHECK([whether _XOPEN_SOURCE should be defined],
+    [ac_cv_should_define__xopen_source],
+    [ac_cv_should_define__xopen_source=no
+     AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM([[
+          #include <wchar.h>
+          mbstate_t x;]])],
+       [],
+       [AC_COMPILE_IFELSE(
+          [AC_LANG_PROGRAM([[
+             #define _XOPEN_SOURCE 500
+             #include <wchar.h>
+             mbstate_t x;]])],
+          [ac_cv_should_define__xopen_source=yes])])])
+  test $ac_cv_should_define__xopen_source = yes &&
+    AC_DEFINE([_XOPEN_SOURCE], [500])
+  AC_DEFINE([_HPUX_ALT_XOPEN_SOCKET_API])
+])# AC_USE_SYSTEM_EXTENSIONS
+
+# gl_USE_SYSTEM_EXTENSIONS
+# ------------------------
+# Enable extensions on systems that normally disable them,
+# typically due to standards-conformance issues.
+AC_DEFUN_ONCE([gl_USE_SYSTEM_EXTENSIONS],
+[
+  dnl Require this macro before AC_USE_SYSTEM_EXTENSIONS.
+  dnl gnulib does not need it. But if it gets required by third-party macros
+  dnl after AC_USE_SYSTEM_EXTENSIONS is required, autoconf 2.62..2.63 emit a
+  dnl warning: "AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS".
+  dnl Note: We can do this only for one of the macros AC_AIX, AC_GNU_SOURCE,
+  dnl AC_MINIX. If people still use AC_AIX or AC_MINIX, they are out of luck.
+  AC_REQUIRE([AC_GNU_SOURCE])
+
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+])
diff --git a/m4-gl/extern-inline.m4 b/m4-gl/extern-inline.m4
new file mode 100644
index 0000000..ec9f221
--- /dev/null
+++ b/m4-gl/extern-inline.m4
@@ -0,0 +1,114 @@
+dnl 'extern inline' a la ISO C99.
+
+dnl Copyright 2012-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_EXTERN_INLINE],
+[
+  AH_VERBATIM([extern_inline],
+[/* Please see the Gnulib manual for how to use these macros.
+
+   Suppress extern inline with HP-UX cc, as it appears to be broken; see
+   <https://lists.gnu.org/r/bug-texinfo/2013-02/msg00030.html>.
+
+   Suppress extern inline with Sun C in standards-conformance mode, as it
+   mishandles inline functions that call each other.  E.g., for 'inline void f
+   (void) { } inline void g (void) { f (); }', c99 incorrectly complains
+   'reference to static identifier "f" in extern inline function'.
+   This bug was observed with Sun C 5.12 SunOS_i386 2011/11/16.
+
+   Suppress extern inline (with or without __attribute__ ((__gnu_inline__)))
+   on configurations that mistakenly use 'static inline' to implement
+   functions or macros in standard C headers like <ctype.h>.  For example,
+   if isdigit is mistakenly implemented via a static inline function,
+   a program containing an extern inline function that calls isdigit
+   may not work since the C standard prohibits extern inline functions
+   from calling static functions (ISO C 99 section 6.7.4.(3).
+   This bug is known to occur on:
+
+     OS X 10.8 and earlier; see:
+     https://lists.gnu.org/r/bug-gnulib/2012-12/msg00023.html
+
+     DragonFly; see
+     http://muscles.dragonflybsd.org/bulk/bleeding-edge-potential/latest-per-pkg/ah-tty-0.3.12.log
+
+     FreeBSD; see:
+     https://lists.gnu.org/r/bug-gnulib/2014-07/msg00104.html
+
+   OS X 10.9 has a macro __header_inline indicating the bug is fixed for C and
+   for clang but remains for g++; see <https://trac.macports.org/ticket/41033>.
+   Assume DragonFly and FreeBSD will be similar.
+
+   GCC 4.3 and above with -std=c99 or -std=gnu99 implements ISO C99
+   inline semantics, unless -fgnu89-inline is used.  It defines a macro
+   __GNUC_STDC_INLINE__ to indicate this situation or a macro
+   __GNUC_GNU_INLINE__ to indicate the opposite situation.
+   GCC 4.2 with -std=c99 or -std=gnu99 implements the GNU C inline
+   semantics but warns, unless -fgnu89-inline is used:
+     warning: C99 inline functions are not supported; using GNU89
+     warning: to disable this warning use -fgnu89-inline or the gnu_inline function attribute
+   It defines a macro __GNUC_GNU_INLINE__ to indicate this situation.
+ */
+#if (((defined __APPLE__ && defined __MACH__) \
+      || defined __DragonFly__ || defined __FreeBSD__) \
+     && (defined __header_inline \
+         ? (defined __cplusplus && defined __GNUC_STDC_INLINE__ \
+            && ! defined __clang__) \
+         : ((! defined _DONT_USE_CTYPE_INLINE_ \
+             && (defined __GNUC__ || defined __cplusplus)) \
+            || (defined _FORTIFY_SOURCE && 0 < _FORTIFY_SOURCE \
+                && defined __GNUC__ && ! defined __cplusplus))))
+# define _GL_EXTERN_INLINE_STDHEADER_BUG
+#endif
+#if ((__GNUC__ \
+      ? defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__ \
+      : (199901L <= __STDC_VERSION__ \
+         && !defined __HP_cc \
+         && !defined __PGI \
+         && !(defined __SUNPRO_C && __STDC__))) \
+     && !defined _GL_EXTERN_INLINE_STDHEADER_BUG)
+# define _GL_INLINE inline
+# define _GL_EXTERN_INLINE extern inline
+# define _GL_EXTERN_INLINE_IN_USE
+#elif (2 < __GNUC__ + (7 <= __GNUC_MINOR__) && !defined __STRICT_ANSI__ \
+       && !defined _GL_EXTERN_INLINE_STDHEADER_BUG)
+# if defined __GNUC_GNU_INLINE__ && __GNUC_GNU_INLINE__
+   /* __gnu_inline__ suppresses a GCC 4.2 diagnostic.  */
+#  define _GL_INLINE extern inline __attribute__ ((__gnu_inline__))
+# else
+#  define _GL_INLINE extern inline
+# endif
+# define _GL_EXTERN_INLINE extern
+# define _GL_EXTERN_INLINE_IN_USE
+#else
+# define _GL_INLINE static _GL_UNUSED
+# define _GL_EXTERN_INLINE static _GL_UNUSED
+#endif
+
+/* In GCC 4.6 (inclusive) to 5.1 (exclusive),
+   suppress bogus "no previous prototype for 'FOO'"
+   and "no previous declaration for 'FOO'" diagnostics,
+   when FOO is an inline function in the header; see
+   <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54113> and
+   <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63877>.  */
+#if __GNUC__ == 4 && 6 <= __GNUC_MINOR__
+# if defined __GNUC_STDC_INLINE__ && __GNUC_STDC_INLINE__
+#  define _GL_INLINE_HEADER_CONST_PRAGMA
+# else
+#  define _GL_INLINE_HEADER_CONST_PRAGMA \
+     _Pragma ("GCC diagnostic ignored \"-Wsuggest-attribute=const\"")
+# endif
+# define _GL_INLINE_HEADER_BEGIN \
+    _Pragma ("GCC diagnostic push") \
+    _Pragma ("GCC diagnostic ignored \"-Wmissing-prototypes\"") \
+    _Pragma ("GCC diagnostic ignored \"-Wmissing-declarations\"") \
+    _GL_INLINE_HEADER_CONST_PRAGMA
+# define _GL_INLINE_HEADER_END \
+    _Pragma ("GCC diagnostic pop")
+#else
+# define _GL_INLINE_HEADER_BEGIN
+# define _GL_INLINE_HEADER_END
+#endif])
+])
diff --git a/m4-gl/gnulib-common.m4 b/m4-gl/gnulib-common.m4
new file mode 100644
index 0000000..57b94ed
--- /dev/null
+++ b/m4-gl/gnulib-common.m4
@@ -0,0 +1,424 @@
+# gnulib-common.m4 serial 44
+dnl Copyright (C) 2007-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_PREREQ([2.62])
+
+# gl_COMMON
+# is expanded unconditionally through gnulib-tool magic.
+AC_DEFUN([gl_COMMON], [
+  dnl Use AC_REQUIRE here, so that the code is expanded once only.
+  AC_REQUIRE([gl_00GNULIB])
+  AC_REQUIRE([gl_COMMON_BODY])
+])
+AC_DEFUN([gl_COMMON_BODY], [
+  AH_VERBATIM([_Noreturn],
+[/* The _Noreturn keyword of C11.  */
+#ifndef _Noreturn
+# if (defined __cplusplus \
+      && ((201103 <= __cplusplus && !(__GNUC__ == 4 && __GNUC_MINOR__ == 7)) \
+          || (defined _MSC_VER && 1900 <= _MSC_VER)))
+#  define _Noreturn [[noreturn]]
+# elif ((!defined __cplusplus || defined __clang__) \
+        && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0)  \
+            || 4 < __GNUC__ + (7 <= __GNUC_MINOR__)))
+   /* _Noreturn works as-is.  */
+# elif 2 < __GNUC__ + (8 <= __GNUC_MINOR__) || 0x5110 <= __SUNPRO_C
+#  define _Noreturn __attribute__ ((__noreturn__))
+# elif 1200 <= (defined _MSC_VER ? _MSC_VER : 0)
+#  define _Noreturn __declspec (noreturn)
+# else
+#  define _Noreturn
+# endif
+#endif
+])
+  AH_VERBATIM([isoc99_inline],
+[/* Work around a bug in Apple GCC 4.0.1 build 5465: In C99 mode, it supports
+   the ISO C 99 semantics of 'extern inline' (unlike the GNU C semantics of
+   earlier versions), but does not display it by setting __GNUC_STDC_INLINE__.
+   __APPLE__ && __MACH__ test for Mac OS X.
+   __APPLE_CC__ tests for the Apple compiler and its version.
+   __STDC_VERSION__ tests for the C99 mode.  */
+#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__))
+#else
+# define _GL_UNUSED
+#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
+#else
+# define _GL_UNUSED_LABEL
+#endif
+
+/* The __pure__ attribute was added in gcc 2.96.  */
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
+# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
+#else
+# define _GL_ATTRIBUTE_PURE /* empty */
+#endif
+
+/* The __const__ attribute was added in gcc 2.95.  */
+#if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95)
+# define _GL_ATTRIBUTE_CONST __attribute__ ((__const__))
+#else
+# define _GL_ATTRIBUTE_CONST /* empty */
+#endif
+
+/* The __malloc__ attribute was added in gcc 3.  */
+#if 3 <= __GNUC__
+# define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
+#else
+# define _GL_ATTRIBUTE_MALLOC /* empty */
+#endif
+])
+  AH_VERBATIM([async_safe],
+[/* The _GL_ASYNC_SAFE marker should be attached to functions that are
+   signal handlers (for signals other than SIGABRT, SIGPIPE) or can be
+   invoked from such signal handlers.  Such functions have some restrictions:
+     * All functions that it calls should be marked _GL_ASYNC_SAFE as well,
+       or should be listed as async-signal-safe in POSIX
+       <http://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html#tag_15_04>
+       section 2.4.3.  Note that malloc(), sprintf(), and fwrite(), in
+       particular, are NOT async-signal-safe.
+     * All memory locations (variables and struct fields) that these functions
+       access must be marked 'volatile'.  This holds for both read and write
+       accesses.  Otherwise the compiler might optimize away stores to and
+       reads from such locations that occur in the program, depending on its
+       data flow analysis.  For example, when the program contains a loop
+       that is intended to inspect a variable set from within a signal handler
+           while (!signal_occurred)
+             ;
+       the compiler is allowed to transform this into an endless loop if the
+       variable 'signal_occurred' is not declared 'volatile'.
+   Additionally, recall that:
+     * A signal handler should not modify errno (except if it is a handler
+       for a fatal signal and ends by raising the same signal again, thus
+       provoking the termination of the process).  If it invokes a function
+       that may clobber errno, it needs to save and restore the value of
+       errno.  */
+#define _GL_ASYNC_SAFE
+])
+  dnl Preparation for running test programs:
+  dnl Tell glibc to write diagnostics from -D_FORTIFY_SOURCE=2 to stderr, not
+  dnl to /dev/tty, so they can be redirected to log files.  Such diagnostics
+  dnl arise e.g., in the macros gl_PRINTF_DIRECTIVE_N, gl_SNPRINTF_DIRECTIVE_N.
+  LIBC_FATAL_STDERR_=1
+  export LIBC_FATAL_STDERR_
+])
+
+# gl_MODULE_INDICATOR_CONDITION
+# expands to a C preprocessor expression that evaluates to 1 or 0, depending
+# whether a gnulib module that has been requested shall be considered present
+# or not.
+m4_define([gl_MODULE_INDICATOR_CONDITION], [1])
+
+# gl_MODULE_INDICATOR_SET_VARIABLE([modulename])
+# sets the shell variable that indicates the presence of the given module to
+# a C preprocessor expression that will evaluate to 1.
+AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE],
+[
+  gl_MODULE_INDICATOR_SET_VARIABLE_AUX(
+    [GNULIB_[]m4_translit([[$1]],
+                          [abcdefghijklmnopqrstuvwxyz./-],
+                          [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])],
+    [gl_MODULE_INDICATOR_CONDITION])
+])
+
+# gl_MODULE_INDICATOR_SET_VARIABLE_AUX([variable])
+# modifies the shell variable to include the gl_MODULE_INDICATOR_CONDITION.
+# The shell variable's value is a C preprocessor expression that evaluates
+# to 0 or 1.
+AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX],
+[
+  m4_if(m4_defn([gl_MODULE_INDICATOR_CONDITION]), [1],
+    [
+     dnl Simplify the expression VALUE || 1 to 1.
+     $1=1
+    ],
+    [gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([$1],
+                                             [gl_MODULE_INDICATOR_CONDITION])])
+])
+
+# gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([variable], [condition])
+# modifies the shell variable to include the given condition.  The shell
+# variable's value is a C preprocessor expression that evaluates to 0 or 1.
+AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR],
+[
+  dnl Simplify the expression 1 || CONDITION to 1.
+  if test "$[]$1" != 1; then
+    dnl Simplify the expression 0 || CONDITION to CONDITION.
+    if test "$[]$1" = 0; then
+      $1=$2
+    else
+      $1="($[]$1 || $2)"
+    fi
+  fi
+])
+
+# gl_MODULE_INDICATOR([modulename])
+# defines a C macro indicating the presence of the given module
+# in a location where it can be used.
+#                                             |  Value  |   Value   |
+#                                             | in lib/ | in tests/ |
+# --------------------------------------------+---------+-----------+
+# Module present among main modules:          |    1    |     1     |
+# --------------------------------------------+---------+-----------+
+# Module present among tests-related modules: |    0    |     1     |
+# --------------------------------------------+---------+-----------+
+# Module not present at all:                  |    0    |     0     |
+# --------------------------------------------+---------+-----------+
+AC_DEFUN([gl_MODULE_INDICATOR],
+[
+  AC_DEFINE_UNQUOTED([GNULIB_]m4_translit([[$1]],
+      [abcdefghijklmnopqrstuvwxyz./-],
+      [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]),
+    [gl_MODULE_INDICATOR_CONDITION],
+    [Define to a C preprocessor expression that evaluates to 1 or 0,
+     depending whether the gnulib module $1 shall be considered present.])
+])
+
+# gl_MODULE_INDICATOR_FOR_TESTS([modulename])
+# defines a C macro indicating the presence of the given module
+# in lib or tests. This is useful to determine whether the module
+# should be tested.
+#                                             |  Value  |   Value   |
+#                                             | in lib/ | in tests/ |
+# --------------------------------------------+---------+-----------+
+# Module present among main modules:          |    1    |     1     |
+# --------------------------------------------+---------+-----------+
+# Module present among tests-related modules: |    1    |     1     |
+# --------------------------------------------+---------+-----------+
+# Module not present at all:                  |    0    |     0     |
+# --------------------------------------------+---------+-----------+
+AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS],
+[
+  AC_DEFINE([GNULIB_TEST_]m4_translit([[$1]],
+      [abcdefghijklmnopqrstuvwxyz./-],
+      [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]), [1],
+    [Define to 1 when the gnulib module $1 should be tested.])
+])
+
+# gl_ASSERT_NO_GNULIB_POSIXCHECK
+# asserts that there will never be a need to #define GNULIB_POSIXCHECK.
+# and thereby enables an optimization of configure and config.h.
+# Used by Emacs.
+AC_DEFUN([gl_ASSERT_NO_GNULIB_POSIXCHECK],
+[
+  dnl Override gl_WARN_ON_USE_PREPARE.
+  dnl But hide this definition from 'aclocal'.
+  AC_DEFUN([gl_W][ARN_ON_USE_PREPARE], [])
+])
+
+# gl_ASSERT_NO_GNULIB_TESTS
+# asserts that there will be no gnulib tests in the scope of the configure.ac
+# and thereby enables an optimization of config.h.
+# Used by Emacs.
+AC_DEFUN([gl_ASSERT_NO_GNULIB_TESTS],
+[
+  dnl Override gl_MODULE_INDICATOR_FOR_TESTS.
+  AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS], [])
+])
+
+# Test whether <features.h> exists.
+# Set HAVE_FEATURES_H.
+AC_DEFUN([gl_FEATURES_H],
+[
+  AC_CHECK_HEADERS_ONCE([features.h])
+  if test $ac_cv_header_features_h = yes; then
+    HAVE_FEATURES_H=1
+  else
+    HAVE_FEATURES_H=0
+  fi
+  AC_SUBST([HAVE_FEATURES_H])
+])
+
+# AS_VAR_IF(VAR, VALUE, [IF-MATCH], [IF-NOT-MATCH])
+# ----------------------------------------------------
+# Backport of autoconf-2.63b's macro.
+# Remove this macro when we can assume autoconf >= 2.64.
+m4_ifndef([AS_VAR_IF],
+[m4_define([AS_VAR_IF],
+[AS_IF([test x"AS_VAR_GET([$1])" = x""$2], [$3], [$4])])])
+
+# gl_PROG_CC_C99
+# Modifies the value of the shell variable CC in an attempt to make $CC
+# understand ISO C99 source code.
+# This is like AC_PROG_CC_C99, except that
+# - AC_PROG_CC_C99 does not mix well with AC_PROG_CC_STDC
+#   <https://lists.gnu.org/r/bug-gnulib/2011-09/msg00367.html>,
+#   but many more packages use AC_PROG_CC_STDC than AC_PROG_CC_C99
+#   <https://lists.gnu.org/r/bug-gnulib/2011-09/msg00441.html>.
+# Remaining problems:
+# - When AC_PROG_CC_STDC is invoked twice, it adds the C99 enabling options
+#   to CC twice
+#   <https://lists.gnu.org/r/bug-gnulib/2011-09/msg00431.html>.
+# - AC_PROG_CC_STDC is likely to change now that C11 is an ISO standard.
+AC_DEFUN([gl_PROG_CC_C99],
+[
+  dnl Change that version number to the minimum Autoconf version that supports
+  dnl mixing AC_PROG_CC_C99 calls with AC_PROG_CC_STDC calls.
+  m4_version_prereq([9.0],
+    [AC_REQUIRE([AC_PROG_CC_C99])],
+    [AC_REQUIRE([AC_PROG_CC_STDC])])
+])
+
+# gl_PROG_AR_RANLIB
+# Determines the values for AR, ARFLAGS, RANLIB that fit with the compiler.
+# The user can set the variables AR, ARFLAGS, RANLIB if he wants to override
+# the values.
+AC_DEFUN([gl_PROG_AR_RANLIB],
+[
+  dnl Minix 3 comes with two toolchains: The Amsterdam Compiler Kit compiler
+  dnl as "cc", and GCC as "gcc". They have different object file formats and
+  dnl library formats. In particular, the GNU binutils programs ar and ranlib
+  dnl produce libraries that work only with gcc, not with cc.
+  AC_REQUIRE([AC_PROG_CC])
+  dnl The '][' hides this use from 'aclocal'.
+  AC_BEFORE([$0], [A][M_PROG_AR])
+  AC_CACHE_CHECK([for Minix Amsterdam compiler], [gl_cv_c_amsterdam_compiler],
+    [
+      AC_EGREP_CPP([Amsterdam],
+        [
+#ifdef __ACK__
+Amsterdam
+#endif
+        ],
+        [gl_cv_c_amsterdam_compiler=yes],
+        [gl_cv_c_amsterdam_compiler=no])
+    ])
+
+  dnl Don't compete with AM_PROG_AR's decision about AR/ARFLAGS if we are not
+  dnl building with __ACK__.
+  if test $gl_cv_c_amsterdam_compiler = yes; then
+    if test -z "$AR"; then
+      AR='cc -c.a'
+    fi
+    if test -z "$ARFLAGS"; then
+      ARFLAGS='-o'
+    fi
+  else
+    dnl AM_PROG_AR was added in automake v1.11.2.  AM_PROG_AR does not AC_SUBST
+    dnl ARFLAGS variable (it is filed into Makefile.in directly by automake
+    dnl script on-demand, if not specified by ./configure of course).
+    dnl Don't AC_REQUIRE the AM_PROG_AR otherwise the code for __ACK__ above
+    dnl will be ignored.  Also, pay attention to call AM_PROG_AR in else block
+    dnl because AM_PROG_AR is written so it could re-set AR variable even for
+    dnl __ACK__.  It may seem like its easier to avoid calling the macro here,
+    dnl but we need to AC_SUBST both AR/ARFLAGS (thus those must have some good
+    dnl default value and automake should usually know them).
+    dnl
+    dnl The '][' hides this use from 'aclocal'.
+    m4_ifdef([A][M_PROG_AR], [A][M_PROG_AR], [:])
+  fi
+
+  dnl In case the code above has not helped with setting AR/ARFLAGS, use
+  dnl Automake-documented default values for AR and ARFLAGS, but prefer
+  dnl ${host}-ar over ar (useful for cross-compiling).
+  AC_CHECK_TOOL([AR], [ar], [ar])
+  if test -z "$ARFLAGS"; then
+    ARFLAGS='cr'
+  fi
+
+  AC_SUBST([AR])
+  AC_SUBST([ARFLAGS])
+  if test -z "$RANLIB"; then
+    if test $gl_cv_c_amsterdam_compiler = yes; then
+      RANLIB=':'
+    else
+      dnl Use the ranlib program if it is available.
+      AC_PROG_RANLIB
+    fi
+  fi
+  AC_SUBST([RANLIB])
+])
+
+# AC_C_RESTRICT
+# This definition is copied from post-2.69 Autoconf and overrides the
+# AC_C_RESTRICT macro from autoconf 2.60..2.69.  It can be removed
+# once autoconf >= 2.70 can be assumed.  It's painful to check version
+# numbers, and in practice this macro is more up-to-date than Autoconf
+# is, so override Autoconf unconditionally.
+AC_DEFUN([AC_C_RESTRICT],
+[AC_CACHE_CHECK([for C/C++ restrict keyword], [ac_cv_c_restrict],
+  [ac_cv_c_restrict=no
+   # The order here caters to the fact that C++ does not require restrict.
+   for ac_kw in __restrict __restrict__ _Restrict restrict; do
+     AC_COMPILE_IFELSE(
+      [AC_LANG_PROGRAM(
+         [[typedef int *int_ptr;
+           int foo (int_ptr $ac_kw ip) { return ip[0]; }
+           int bar (int [$ac_kw]); /* Catch GCC bug 14050.  */
+           int bar (int ip[$ac_kw]) { return ip[0]; }
+         ]],
+         [[int s[1];
+           int *$ac_kw t = s;
+           t[0] = 0;
+           return foo (t) + bar (t);
+         ]])],
+      [ac_cv_c_restrict=$ac_kw])
+     test "$ac_cv_c_restrict" != no && break
+   done
+  ])
+ AH_VERBATIM([restrict],
+[/* Define to the equivalent of the C99 'restrict' keyword, or to
+   nothing if this is not supported.  Do not define if restrict is
+   supported directly.  */
+#undef restrict
+/* Work around a bug in Sun C++: it does not support _Restrict or
+   __restrict__, even though the corresponding Sun C compiler ends up with
+   "#define restrict _Restrict" or "#define restrict __restrict__" in the
+   previous line.  Perhaps some future version of Sun C++ will work with
+   restrict; if so, hopefully it defines __RESTRICT like Sun C does.  */
+#if defined __SUNPRO_CC && !defined __RESTRICT
+# define _Restrict
+# define __restrict__
+#endif])
+ case $ac_cv_c_restrict in
+   restrict) ;;
+   no) AC_DEFINE([restrict], []) ;;
+   *)  AC_DEFINE_UNQUOTED([restrict], [$ac_cv_c_restrict]) ;;
+ esac
+])# AC_C_RESTRICT
+
+# gl_BIGENDIAN
+# is like AC_C_BIGENDIAN, except that it can be AC_REQUIREd.
+# Note that AC_REQUIRE([AC_C_BIGENDIAN]) does not work reliably because some
+# macros invoke AC_C_BIGENDIAN with arguments.
+AC_DEFUN([gl_BIGENDIAN],
+[
+  AC_C_BIGENDIAN
+])
+
+# gl_CACHE_VAL_SILENT(cache-id, command-to-set-it)
+# is like AC_CACHE_VAL(cache-id, command-to-set-it), except that it does not
+# output a spurious "(cached)" mark in the midst of other configure output.
+# This macro should be used instead of AC_CACHE_VAL when it is not surrounded
+# by an AC_MSG_CHECKING/AC_MSG_RESULT pair.
+AC_DEFUN([gl_CACHE_VAL_SILENT],
+[
+  saved_as_echo_n="$as_echo_n"
+  as_echo_n=':'
+  AC_CACHE_VAL([$1], [$2])
+  as_echo_n="$saved_as_echo_n"
+])
+
+# AS_VAR_COPY was added in autoconf 2.63b
+m4_define_default([AS_VAR_COPY],
+[AS_LITERAL_IF([$1[]$2], [$1=$$2], [eval $1=\$$2])])
diff --git a/m4-gl/gnulib-comp.m4 b/m4-gl/gnulib-comp.m4
new file mode 100644
index 0000000..3503171
--- /dev/null
+++ b/m4-gl/gnulib-comp.m4
@@ -0,0 +1,307 @@
+# DO NOT EDIT! GENERATED AUTOMATICALLY!
+# Copyright (C) 2002-2019 Free Software Foundation, Inc.
+#
+# 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
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This file 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 file.  If not, see <https://www.gnu.org/licenses/>.
+#
+# As a special exception to the GNU General Public License,
+# this file may be distributed as part of a program that
+# contains a configuration script generated by Autoconf, under
+# the same distribution terms as the rest of that program.
+#
+# Generated by gnulib-tool.
+#
+# This file represents the compiled summary of the specification in
+# gnulib-cache.m4. It lists the computed macro invocations that need
+# to be invoked from configure.ac.
+# In projects that use version control, this file can be treated like
+# other built files.
+
+
+# This macro should be invoked from ./configure.ac, in the section
+# "Checks for programs", right after AC_PROG_CC, and certainly before
+# any checks for libraries, header files, types and library functions.
+AC_DEFUN([gl_EARLY],
+[
+  m4_pattern_forbid([^gl_[A-Z]])dnl the gnulib macro namespace
+  m4_pattern_allow([^gl_ES$])dnl a valid locale name
+  m4_pattern_allow([^gl_LIBOBJS$])dnl a variable
+  m4_pattern_allow([^gl_LTLIBOBJS$])dnl a variable
+
+  # Pre-early section.
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+  AC_REQUIRE([gl_PROG_AR_RANLIB])
+
+  # Code from module absolute-header:
+  # Code from module extensions:
+  # Code from module extern-inline:
+  # Code from module gnumakefile:
+  # Code from module hash-pjw-bare:
+  # Code from module include_next:
+  # Code from module intprops:
+  # Code from module lib-symbol-versions:
+  # Code from module lib-symbol-visibility:
+  # Code from module libc-config:
+  # Code from module limits-h:
+  # Code from module maintainer-makefile:
+  # Code from module minmax:
+  # Code from module multiarch:
+  # Code from module snippet/arg-nonnull:
+  # Code from module snippet/c++defs:
+  # Code from module snippet/warn-on-use:
+  # Code from module ssize_t:
+  # Code from module stddef:
+  # Code from module stdint:
+  # Code from module string:
+  # Code from module strverscmp:
+  # Code from module sys_types:
+  # Code from module useless-if-before-free:
+  # Code from module valgrind-tests:
+  # Code from module vc-list-files:
+])
+
+# This macro should be invoked from ./configure.ac, in the section
+# "Check for header files, types and library functions".
+AC_DEFUN([gl_INIT],
+[
+  AM_CONDITIONAL([GL_COND_LIBTOOL], [true])
+  gl_cond_libtool=true
+  gl_m4_base='m4-gl'
+  m4_pushdef([AC_LIBOBJ], m4_defn([gl_LIBOBJ]))
+  m4_pushdef([AC_REPLACE_FUNCS], m4_defn([gl_REPLACE_FUNCS]))
+  m4_pushdef([AC_LIBSOURCES], m4_defn([gl_LIBSOURCES]))
+  m4_pushdef([gl_LIBSOURCES_LIST], [])
+  m4_pushdef([gl_LIBSOURCES_DIR], [])
+  gl_COMMON
+  gl_source_base='lib/gl'
+  AC_REQUIRE([gl_EXTERN_INLINE])
+  # Autoconf 2.61a.99 and earlier don't support linking a file only
+  # in VPATH builds.  But since GNUmakefile is for maintainer use
+  # only, it does not matter if we skip the link with older autoconf.
+  # Automake 1.10.1 and earlier try to remove GNUmakefile in non-VPATH
+  # builds, so use a shell variable to bypass this.
+  GNUmakefile=GNUmakefile
+  m4_if(m4_version_compare([2.61a.100],
+          m4_defn([m4_PACKAGE_VERSION])), [1], [],
+        [AC_CONFIG_LINKS([$GNUmakefile:$GNUmakefile], [],
+          [GNUmakefile=$GNUmakefile])])
+  gl_LD_VERSION_SCRIPT
+  gl_VISIBILITY
+  gl___INLINE
+  gl_LIMITS_H
+  AC_CONFIG_COMMANDS_PRE([m4_ifdef([AH_HEADER],
+    [AC_SUBST([CONFIG_INCLUDE], m4_defn([AH_HEADER]))])])
+  AC_REQUIRE([AC_PROG_SED])
+  AC_REQUIRE([AC_PROG_GREP])
+  gl_MINMAX
+  gl_MULTIARCH
+  gt_TYPE_SSIZE_T
+  gl_STDDEF_H
+  gl_STDINT_H
+  gl_HEADER_STRING_H
+  gl_FUNC_STRVERSCMP
+  if test $HAVE_STRVERSCMP = 0; then
+    AC_LIBOBJ([strverscmp])
+    gl_PREREQ_STRVERSCMP
+  fi
+  gl_STRING_MODULE_INDICATOR([strverscmp])
+  gl_SYS_TYPES_H
+  AC_PROG_MKDIR_P
+  gl_VALGRIND_TESTS
+  # End of code from modules
+  m4_ifval(gl_LIBSOURCES_LIST, [
+    m4_syscmd([test ! -d ]m4_defn([gl_LIBSOURCES_DIR])[ ||
+      for gl_file in ]gl_LIBSOURCES_LIST[ ; do
+        if test ! -r ]m4_defn([gl_LIBSOURCES_DIR])[/$gl_file ; then
+          echo "missing file ]m4_defn([gl_LIBSOURCES_DIR])[/$gl_file" >&2
+          exit 1
+        fi
+      done])dnl
+      m4_if(m4_sysval, [0], [],
+        [AC_FATAL([expected source file, required through AC_LIBSOURCES, not found])])
+  ])
+  m4_popdef([gl_LIBSOURCES_DIR])
+  m4_popdef([gl_LIBSOURCES_LIST])
+  m4_popdef([AC_LIBSOURCES])
+  m4_popdef([AC_REPLACE_FUNCS])
+  m4_popdef([AC_LIBOBJ])
+  AC_CONFIG_COMMANDS_PRE([
+    gl_libobjs=
+    gl_ltlibobjs=
+    if test -n "$gl_LIBOBJS"; then
+      # Remove the extension.
+      sed_drop_objext='s/\.o$//;s/\.obj$//'
+      for i in `for i in $gl_LIBOBJS; do echo "$i"; done | sed -e "$sed_drop_objext" | sort | uniq`; do
+        gl_libobjs="$gl_libobjs $i.$ac_objext"
+        gl_ltlibobjs="$gl_ltlibobjs $i.lo"
+      done
+    fi
+    AC_SUBST([gl_LIBOBJS], [$gl_libobjs])
+    AC_SUBST([gl_LTLIBOBJS], [$gl_ltlibobjs])
+  ])
+  gltests_libdeps=
+  gltests_ltlibdeps=
+  m4_pushdef([AC_LIBOBJ], m4_defn([gltests_LIBOBJ]))
+  m4_pushdef([AC_REPLACE_FUNCS], m4_defn([gltests_REPLACE_FUNCS]))
+  m4_pushdef([AC_LIBSOURCES], m4_defn([gltests_LIBSOURCES]))
+  m4_pushdef([gltests_LIBSOURCES_LIST], [])
+  m4_pushdef([gltests_LIBSOURCES_DIR], [])
+  gl_COMMON
+  gl_source_base='tests-gl'
+changequote(,)dnl
+  gltests_WITNESS=IN_`echo "${PACKAGE-$PACKAGE_TARNAME}" | LC_ALL=C tr abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ | LC_ALL=C sed -e 's/[^A-Z0-9_]/_/g'`_GNULIB_TESTS
+changequote([, ])dnl
+  AC_SUBST([gltests_WITNESS])
+  gl_module_indicator_condition=$gltests_WITNESS
+  m4_pushdef([gl_MODULE_INDICATOR_CONDITION], [$gl_module_indicator_condition])
+  gl_VALGRIND_TESTS
+  m4_popdef([gl_MODULE_INDICATOR_CONDITION])
+  m4_ifval(gltests_LIBSOURCES_LIST, [
+    m4_syscmd([test ! -d ]m4_defn([gltests_LIBSOURCES_DIR])[ ||
+      for gl_file in ]gltests_LIBSOURCES_LIST[ ; do
+        if test ! -r ]m4_defn([gltests_LIBSOURCES_DIR])[/$gl_file ; then
+          echo "missing file ]m4_defn([gltests_LIBSOURCES_DIR])[/$gl_file" >&2
+          exit 1
+        fi
+      done])dnl
+      m4_if(m4_sysval, [0], [],
+        [AC_FATAL([expected source file, required through AC_LIBSOURCES, not found])])
+  ])
+  m4_popdef([gltests_LIBSOURCES_DIR])
+  m4_popdef([gltests_LIBSOURCES_LIST])
+  m4_popdef([AC_LIBSOURCES])
+  m4_popdef([AC_REPLACE_FUNCS])
+  m4_popdef([AC_LIBOBJ])
+  AC_CONFIG_COMMANDS_PRE([
+    gltests_libobjs=
+    gltests_ltlibobjs=
+    if test -n "$gltests_LIBOBJS"; then
+      # Remove the extension.
+      sed_drop_objext='s/\.o$//;s/\.obj$//'
+      for i in `for i in $gltests_LIBOBJS; do echo "$i"; done | sed -e "$sed_drop_objext" | sort | uniq`; do
+        gltests_libobjs="$gltests_libobjs $i.$ac_objext"
+        gltests_ltlibobjs="$gltests_ltlibobjs $i.lo"
+      done
+    fi
+    AC_SUBST([gltests_LIBOBJS], [$gltests_libobjs])
+    AC_SUBST([gltests_LTLIBOBJS], [$gltests_ltlibobjs])
+  ])
+  LIBTESTS_LIBDEPS="$gltests_libdeps"
+  AC_SUBST([LIBTESTS_LIBDEPS])
+])
+
+# Like AC_LIBOBJ, except that the module name goes
+# into gl_LIBOBJS instead of into LIBOBJS.
+AC_DEFUN([gl_LIBOBJ], [
+  AS_LITERAL_IF([$1], [gl_LIBSOURCES([$1.c])])dnl
+  gl_LIBOBJS="$gl_LIBOBJS $1.$ac_objext"
+])
+
+# Like AC_REPLACE_FUNCS, except that the module name goes
+# into gl_LIBOBJS instead of into LIBOBJS.
+AC_DEFUN([gl_REPLACE_FUNCS], [
+  m4_foreach_w([gl_NAME], [$1], [AC_LIBSOURCES(gl_NAME[.c])])dnl
+  AC_CHECK_FUNCS([$1], , [gl_LIBOBJ($ac_func)])
+])
+
+# Like AC_LIBSOURCES, except the directory where the source file is
+# expected is derived from the gnulib-tool parameterization,
+# and alloca is special cased (for the alloca-opt module).
+# We could also entirely rely on EXTRA_lib..._SOURCES.
+AC_DEFUN([gl_LIBSOURCES], [
+  m4_foreach([_gl_NAME], [$1], [
+    m4_if(_gl_NAME, [alloca.c], [], [
+      m4_define([gl_LIBSOURCES_DIR], [lib/gl])
+      m4_append([gl_LIBSOURCES_LIST], _gl_NAME, [ ])
+    ])
+  ])
+])
+
+# Like AC_LIBOBJ, except that the module name goes
+# into gltests_LIBOBJS instead of into LIBOBJS.
+AC_DEFUN([gltests_LIBOBJ], [
+  AS_LITERAL_IF([$1], [gltests_LIBSOURCES([$1.c])])dnl
+  gltests_LIBOBJS="$gltests_LIBOBJS $1.$ac_objext"
+])
+
+# Like AC_REPLACE_FUNCS, except that the module name goes
+# into gltests_LIBOBJS instead of into LIBOBJS.
+AC_DEFUN([gltests_REPLACE_FUNCS], [
+  m4_foreach_w([gl_NAME], [$1], [AC_LIBSOURCES(gl_NAME[.c])])dnl
+  AC_CHECK_FUNCS([$1], , [gltests_LIBOBJ($ac_func)])
+])
+
+# Like AC_LIBSOURCES, except the directory where the source file is
+# expected is derived from the gnulib-tool parameterization,
+# and alloca is special cased (for the alloca-opt module).
+# We could also entirely rely on EXTRA_lib..._SOURCES.
+AC_DEFUN([gltests_LIBSOURCES], [
+  m4_foreach([_gl_NAME], [$1], [
+    m4_if(_gl_NAME, [alloca.c], [], [
+      m4_define([gltests_LIBSOURCES_DIR], [tests-gl])
+      m4_append([gltests_LIBSOURCES_LIST], _gl_NAME, [ ])
+    ])
+  ])
+])
+
+# This macro records the list of files which have been installed by
+# gnulib-tool and may be removed by future gnulib-tool invocations.
+AC_DEFUN([gl_FILE_LIST], [
+  build-aux/useless-if-before-free
+  build-aux/vc-list-files
+  lib/arg-nonnull.h
+  lib/c++defs.h
+  lib/cdefs.h
+  lib/hash-pjw-bare.c
+  lib/hash-pjw-bare.h
+  lib/intprops.h
+  lib/libc-config.h
+  lib/limits.in.h
+  lib/minmax.h
+  lib/stddef.in.h
+  lib/stdint.in.h
+  lib/string.in.h
+  lib/strverscmp.c
+  lib/sys_types.in.h
+  lib/warn-on-use.h
+  m4/00gnulib.m4
+  m4/__inline.m4
+  m4/absolute-header.m4
+  m4/extensions.m4
+  m4/extern-inline.m4
+  m4/gnulib-common.m4
+  m4/include_next.m4
+  m4/ld-version-script.m4
+  m4/limits-h.m4
+  m4/longlong.m4
+  m4/minmax.m4
+  m4/multiarch.m4
+  m4/off_t.m4
+  m4/ssize_t.m4
+  m4/stddef_h.m4
+  m4/stdint.m4
+  m4/string_h.m4
+  m4/strverscmp.m4
+  m4/sys_types_h.m4
+  m4/valgrind-tests.m4
+  m4/visibility.m4
+  m4/warn-on-use.m4
+  m4/wchar_t.m4
+  m4/wint_t.m4
+  tests=lib/arg-nonnull.h
+  tests=lib/c++defs.h
+  tests=lib/dummy.c
+  tests=lib/warn-on-use.h
+  top/GNUmakefile
+  top/maint.mk
+])
diff --git a/m4-gl/include_next.m4 b/m4-gl/include_next.m4
new file mode 100644
index 0000000..86eb2c9
--- /dev/null
+++ b/m4-gl/include_next.m4
@@ -0,0 +1,224 @@
+# include_next.m4 serial 24
+dnl Copyright (C) 2006-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Paul Eggert and Derek Price.
+
+dnl Sets INCLUDE_NEXT, INCLUDE_NEXT_AS_FIRST_DIRECTIVE, PRAGMA_SYSTEM_HEADER,
+dnl and PRAGMA_COLUMNS.
+dnl
+dnl INCLUDE_NEXT expands to 'include_next' if the compiler supports it, or to
+dnl 'include' otherwise.
+dnl
+dnl INCLUDE_NEXT_AS_FIRST_DIRECTIVE expands to 'include_next' if the compiler
+dnl supports it in the special case that it is the first include directive in
+dnl the given file, or to 'include' otherwise.
+dnl
+dnl PRAGMA_SYSTEM_HEADER can be used in files that contain #include_next,
+dnl so as to avoid GCC warnings when the gcc option -pedantic is used.
+dnl '#pragma GCC system_header' has the same effect as if the file was found
+dnl through the include search path specified with '-isystem' options (as
+dnl opposed to the search path specified with '-I' options). Namely, gcc
+dnl does not warn about some things, and on some systems (Solaris and Interix)
+dnl __STDC__ evaluates to 0 instead of to 1. The latter is an undesired side
+dnl effect; we are therefore careful to use 'defined __STDC__' or '1' instead
+dnl of plain '__STDC__'.
+dnl
+dnl PRAGMA_COLUMNS can be used in files that override system header files, so
+dnl as to avoid compilation errors on HP NonStop systems when the gnulib file
+dnl is included by a system header file that does a "#pragma COLUMNS 80" (which
+dnl has the effect of truncating the lines of that file and all files that it
+dnl includes to 80 columns) and the gnulib file has lines longer than 80
+dnl columns.
+
+AC_DEFUN([gl_INCLUDE_NEXT],
+[
+  AC_LANG_PREPROC_REQUIRE()
+  AC_CACHE_CHECK([whether the preprocessor supports include_next],
+    [gl_cv_have_include_next],
+    [rm -rf conftestd1a conftestd1b conftestd2
+     mkdir conftestd1a conftestd1b conftestd2
+     dnl IBM C 9.0, 10.1 (original versions, prior to the 2009-01 updates) on
+     dnl AIX 6.1 support include_next when used as first preprocessor directive
+     dnl in a file, but not when preceded by another include directive. Check
+     dnl for this bug by including <stdio.h>.
+     dnl Additionally, with this same compiler, include_next is a no-op when
+     dnl used in a header file that was included by specifying its absolute
+     dnl file name. Despite these two bugs, include_next is used in the
+     dnl compiler's <math.h>. By virtue of the second bug, we need to use
+     dnl include_next as well in this case.
+     cat <<EOF > conftestd1a/conftest.h
+#define DEFINED_IN_CONFTESTD1
+#include_next <conftest.h>
+#ifdef DEFINED_IN_CONFTESTD2
+int foo;
+#else
+#error "include_next doesn't work"
+#endif
+EOF
+     cat <<EOF > conftestd1b/conftest.h
+#define DEFINED_IN_CONFTESTD1
+#include <stdio.h>
+#include_next <conftest.h>
+#ifdef DEFINED_IN_CONFTESTD2
+int foo;
+#else
+#error "include_next doesn't work"
+#endif
+EOF
+     cat <<EOF > conftestd2/conftest.h
+#ifndef DEFINED_IN_CONFTESTD1
+#error "include_next test doesn't work"
+#endif
+#define DEFINED_IN_CONFTESTD2
+EOF
+     gl_save_CPPFLAGS="$CPPFLAGS"
+     CPPFLAGS="$gl_save_CPPFLAGS -Iconftestd1b -Iconftestd2"
+dnl We intentionally avoid using AC_LANG_SOURCE here.
+     AC_COMPILE_IFELSE([AC_LANG_DEFINES_PROVIDED[#include <conftest.h>]],
+       [gl_cv_have_include_next=yes],
+       [CPPFLAGS="$gl_save_CPPFLAGS -Iconftestd1a -Iconftestd2"
+        AC_COMPILE_IFELSE([AC_LANG_DEFINES_PROVIDED[#include <conftest.h>]],
+          [gl_cv_have_include_next=buggy],
+          [gl_cv_have_include_next=no])
+       ])
+     CPPFLAGS="$gl_save_CPPFLAGS"
+     rm -rf conftestd1a conftestd1b conftestd2
+    ])
+  PRAGMA_SYSTEM_HEADER=
+  if test $gl_cv_have_include_next = yes; then
+    INCLUDE_NEXT=include_next
+    INCLUDE_NEXT_AS_FIRST_DIRECTIVE=include_next
+    if test -n "$GCC"; then
+      PRAGMA_SYSTEM_HEADER='#pragma GCC system_header'
+    fi
+  else
+    if test $gl_cv_have_include_next = buggy; then
+      INCLUDE_NEXT=include
+      INCLUDE_NEXT_AS_FIRST_DIRECTIVE=include_next
+    else
+      INCLUDE_NEXT=include
+      INCLUDE_NEXT_AS_FIRST_DIRECTIVE=include
+    fi
+  fi
+  AC_SUBST([INCLUDE_NEXT])
+  AC_SUBST([INCLUDE_NEXT_AS_FIRST_DIRECTIVE])
+  AC_SUBST([PRAGMA_SYSTEM_HEADER])
+  AC_CACHE_CHECK([whether system header files limit the line length],
+    [gl_cv_pragma_columns],
+    [dnl HP NonStop systems, which define __TANDEM, have this misfeature.
+     AC_EGREP_CPP([choke me],
+       [
+#ifdef __TANDEM
+choke me
+#endif
+       ],
+       [gl_cv_pragma_columns=yes],
+       [gl_cv_pragma_columns=no])
+    ])
+  if test $gl_cv_pragma_columns = yes; then
+    PRAGMA_COLUMNS="#pragma COLUMNS 10000"
+  else
+    PRAGMA_COLUMNS=
+  fi
+  AC_SUBST([PRAGMA_COLUMNS])
+])
+
+# gl_CHECK_NEXT_HEADERS(HEADER1 HEADER2 ...)
+# ------------------------------------------
+# For each arg foo.h, if #include_next works, define NEXT_FOO_H to be
+# '<foo.h>'; otherwise define it to be
+# '"///usr/include/foo.h"', or whatever other absolute file name is suitable.
+# Also, if #include_next works as first preprocessing directive in a file,
+# define NEXT_AS_FIRST_DIRECTIVE_FOO_H to be '<foo.h>'; otherwise define it to
+# be
+# '"///usr/include/foo.h"', or whatever other absolute file name is suitable.
+# That way, a header file with the following line:
+#       #@INCLUDE_NEXT@ @NEXT_FOO_H@
+# or
+#       #@INCLUDE_NEXT_AS_FIRST_DIRECTIVE@ @NEXT_AS_FIRST_DIRECTIVE_FOO_H@
+# behaves (after sed substitution) as if it contained
+#       #include_next <foo.h>
+# even if the compiler does not support include_next.
+# The three "///" are to pacify Sun C 5.8, which otherwise would say
+# "warning: #include of /usr/include/... may be non-portable".
+# Use '""', not '<>', so that the /// cannot be confused with a C99 comment.
+# Note: This macro assumes that the header file is not empty after
+# preprocessing, i.e. it does not only define preprocessor macros but also
+# provides some type/enum definitions or function/variable declarations.
+#
+# This macro also checks whether each header exists, by invoking
+# AC_CHECK_HEADERS_ONCE or AC_CHECK_HEADERS on each argument.
+AC_DEFUN([gl_CHECK_NEXT_HEADERS],
+[
+  gl_NEXT_HEADERS_INTERNAL([$1], [check])
+])
+
+# gl_NEXT_HEADERS(HEADER1 HEADER2 ...)
+# ------------------------------------
+# Like gl_CHECK_NEXT_HEADERS, except do not check whether the headers exist.
+# This is suitable for headers like <stddef.h> that are standardized by C89
+# and therefore can be assumed to exist.
+AC_DEFUN([gl_NEXT_HEADERS],
+[
+  gl_NEXT_HEADERS_INTERNAL([$1], [assume])
+])
+
+# The guts of gl_CHECK_NEXT_HEADERS and gl_NEXT_HEADERS.
+AC_DEFUN([gl_NEXT_HEADERS_INTERNAL],
+[
+  AC_REQUIRE([gl_INCLUDE_NEXT])
+  AC_REQUIRE([AC_CANONICAL_HOST])
+
+  m4_if([$2], [check],
+    [AC_CHECK_HEADERS_ONCE([$1])
+    ])
+
+dnl FIXME: gl_next_header and gl_header_exists must be used unquoted
+dnl until we can assume autoconf 2.64 or newer.
+  m4_foreach_w([gl_HEADER_NAME], [$1],
+    [AS_VAR_PUSHDEF([gl_next_header],
+                    [gl_cv_next_]m4_defn([gl_HEADER_NAME]))
+     if test $gl_cv_have_include_next = yes; then
+       AS_VAR_SET(gl_next_header, ['<'gl_HEADER_NAME'>'])
+     else
+       AC_CACHE_CHECK(
+         [absolute name of <]m4_defn([gl_HEADER_NAME])[>],
+         m4_defn([gl_next_header]),
+         [m4_if([$2], [check],
+            [AS_VAR_PUSHDEF([gl_header_exists],
+                            [ac_cv_header_]m4_defn([gl_HEADER_NAME]))
+             if test AS_VAR_GET(gl_header_exists) = yes; then
+             AS_VAR_POPDEF([gl_header_exists])
+            ])
+           gl_ABSOLUTE_HEADER_ONE(gl_HEADER_NAME)
+           AS_VAR_COPY([gl_header], [gl_cv_absolute_]AS_TR_SH(gl_HEADER_NAME))
+           AS_VAR_SET(gl_next_header, ['"'$gl_header'"'])
+          m4_if([$2], [check],
+            [else
+               AS_VAR_SET(gl_next_header, ['<'gl_HEADER_NAME'>'])
+             fi
+            ])
+         ])
+     fi
+     AC_SUBST(
+       AS_TR_CPP([NEXT_]m4_defn([gl_HEADER_NAME])),
+       [AS_VAR_GET(gl_next_header)])
+     if test $gl_cv_have_include_next = yes || test $gl_cv_have_include_next = buggy; then
+       # INCLUDE_NEXT_AS_FIRST_DIRECTIVE='include_next'
+       gl_next_as_first_directive='<'gl_HEADER_NAME'>'
+     else
+       # INCLUDE_NEXT_AS_FIRST_DIRECTIVE='include'
+       gl_next_as_first_directive=AS_VAR_GET(gl_next_header)
+     fi
+     AC_SUBST(
+       AS_TR_CPP([NEXT_AS_FIRST_DIRECTIVE_]m4_defn([gl_HEADER_NAME])),
+       [$gl_next_as_first_directive])
+     AS_VAR_POPDEF([gl_next_header])])
+])
+
+# Autoconf 2.68 added warnings for our use of AC_COMPILE_IFELSE;
+# this fallback is safe for all earlier autoconf versions.
+m4_define_default([AC_LANG_DEFINES_PROVIDED])
diff --git a/m4-gl/ld-version-script.m4 b/m4-gl/ld-version-script.m4
new file mode 100644
index 0000000..048c536
--- /dev/null
+++ b/m4-gl/ld-version-script.m4
@@ -0,0 +1,48 @@
+# ld-version-script.m4 serial 4
+dnl Copyright (C) 2008-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Simon Josefsson
+
+# FIXME: The test below returns a false positive for mingw
+# cross-compiles, 'local:' statements does not reduce number of
+# exported symbols in a DLL.  Use --disable-ld-version-script to work
+# around the problem.
+
+# gl_LD_VERSION_SCRIPT
+# --------------------
+# Check if LD supports linker scripts, and define automake conditional
+# HAVE_LD_VERSION_SCRIPT if so.
+AC_DEFUN([gl_LD_VERSION_SCRIPT],
+[
+  AC_ARG_ENABLE([ld-version-script],
+    [AS_HELP_STRING([--enable-ld-version-script],
+       [enable linker version script (default is enabled when possible)])],
+    [have_ld_version_script=$enableval],
+    [AC_CACHE_CHECK([if LD -Wl,--version-script works],
+       [gl_cv_sys_ld_version_script],
+       [gl_cv_sys_ld_version_script=no
+        save_LDFLAGS=$LDFLAGS
+        LDFLAGS="$LDFLAGS -Wl,--version-script=conftest.map"
+        echo foo >conftest.map
+        AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])],
+          [],
+          [cat > conftest.map <<EOF
+VERS_1 {
+        global: sym;
+};
+
+VERS_2 {
+        global: sym;
+} VERS_1;
+EOF
+           AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])],
+             [gl_cv_sys_ld_version_script=yes])])
+        rm -f conftest.map
+        LDFLAGS=$save_LDFLAGS])
+     have_ld_version_script=$gl_cv_sys_ld_version_script])
+  AM_CONDITIONAL([HAVE_LD_VERSION_SCRIPT],
+    [test "$have_ld_version_script" = yes])
+])
diff --git a/m4-gl/limits-h.m4 b/m4-gl/limits-h.m4
new file mode 100644
index 0000000..68f724c
--- /dev/null
+++ b/m4-gl/limits-h.m4
@@ -0,0 +1,43 @@
+dnl Check whether limits.h has needed features.
+
+dnl Copyright 2016-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Paul Eggert.
+
+AC_DEFUN_ONCE([gl_LIMITS_H],
+[
+  gl_CHECK_NEXT_HEADERS([limits.h])
+
+  AC_CACHE_CHECK([whether limits.h has LLONG_MAX, WORD_BIT, ULLONG_WIDTH etc.],
+    [gl_cv_header_limits_width],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#ifndef __STDC_WANT_IEC_60559_BFP_EXT__
+             #define __STDC_WANT_IEC_60559_BFP_EXT__ 1
+            #endif
+            #include <limits.h>
+            long long llm = LLONG_MAX;
+            int wb = WORD_BIT;
+            int ullw = ULLONG_WIDTH;
+          ]])],
+       [gl_cv_header_limits_width=yes],
+       [gl_cv_header_limits_width=no])])
+  if test "$gl_cv_header_limits_width" = yes; then
+    LIMITS_H=
+  else
+    LIMITS_H=limits.h
+  fi
+  AC_SUBST([LIMITS_H])
+  AM_CONDITIONAL([GL_GENERATE_LIMITS_H], [test -n "$LIMITS_H"])
+])
+
+dnl Unconditionally enables the replacement of <limits.h>.
+AC_DEFUN([gl_REPLACE_LIMITS_H],
+[
+  AC_REQUIRE([gl_LIMITS_H])
+  LIMITS_H='limits.h'
+  AM_CONDITIONAL([GL_GENERATE_LIMITS_H], [test -n "$LIMITS_H"])
+])
diff --git a/m4-gl/longlong.m4 b/m4-gl/longlong.m4
new file mode 100644
index 0000000..08d0e36
--- /dev/null
+++ b/m4-gl/longlong.m4
@@ -0,0 +1,113 @@
+# longlong.m4 serial 18
+dnl Copyright (C) 1999-2007, 2009-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Paul Eggert.
+
+AC_PREREQ([2.62])
+
+# Define HAVE_LONG_LONG_INT if 'long long int' works.
+# This can be faster than what's in Autoconf 2.62 through 2.68.
+
+# Note: If the type 'long long int' exists but is only 32 bits large
+# (as on some very old compilers), HAVE_LONG_LONG_INT will not be
+# defined. In this case you can treat 'long long int' like 'long int'.
+
+AC_DEFUN([AC_TYPE_LONG_LONG_INT],
+[
+  AC_REQUIRE([AC_TYPE_UNSIGNED_LONG_LONG_INT])
+  AC_CACHE_CHECK([for long long int], [ac_cv_type_long_long_int],
+     [ac_cv_type_long_long_int=yes
+      if test "x${ac_cv_prog_cc_c99-no}" = xno; then
+        ac_cv_type_long_long_int=$ac_cv_type_unsigned_long_long_int
+        if test $ac_cv_type_long_long_int = yes; then
+          dnl Catch a bug in Tandem NonStop Kernel (OSS) cc -O circa 2004.
+          dnl If cross compiling, assume the bug is not important, since
+          dnl nobody cross compiles for this platform as far as we know.
+          AC_RUN_IFELSE(
+            [AC_LANG_PROGRAM(
+               [[@%:@include <limits.h>
+                 @%:@ifndef LLONG_MAX
+                 @%:@ define HALF \
+                          (1LL << (sizeof (long long int) * CHAR_BIT - 2))
+                 @%:@ define LLONG_MAX (HALF - 1 + HALF)
+                 @%:@endif]],
+               [[long long int n = 1;
+                 int i;
+                 for (i = 0; ; i++)
+                   {
+                     long long int m = n << i;
+                     if (m >> i != n)
+                       return 1;
+                     if (LLONG_MAX / 2 < m)
+                       break;
+                   }
+                 return 0;]])],
+            [],
+            [ac_cv_type_long_long_int=no],
+            [:])
+        fi
+      fi])
+  if test $ac_cv_type_long_long_int = yes; then
+    AC_DEFINE([HAVE_LONG_LONG_INT], [1],
+      [Define to 1 if the system has the type 'long long int'.])
+  fi
+])
+
+# Define HAVE_UNSIGNED_LONG_LONG_INT if 'unsigned long long int' works.
+# This can be faster than what's in Autoconf 2.62 through 2.68.
+
+# Note: If the type 'unsigned long long int' exists but is only 32 bits
+# large (as on some very old compilers), AC_TYPE_UNSIGNED_LONG_LONG_INT
+# will not be defined. In this case you can treat 'unsigned long long int'
+# like 'unsigned long int'.
+
+AC_DEFUN([AC_TYPE_UNSIGNED_LONG_LONG_INT],
+[
+  AC_CACHE_CHECK([for unsigned long long int],
+    [ac_cv_type_unsigned_long_long_int],
+    [ac_cv_type_unsigned_long_long_int=yes
+     if test "x${ac_cv_prog_cc_c99-no}" = xno; then
+       AC_LINK_IFELSE(
+         [_AC_TYPE_LONG_LONG_SNIPPET],
+         [],
+         [ac_cv_type_unsigned_long_long_int=no])
+     fi])
+  if test $ac_cv_type_unsigned_long_long_int = yes; then
+    AC_DEFINE([HAVE_UNSIGNED_LONG_LONG_INT], [1],
+      [Define to 1 if the system has the type 'unsigned long long int'.])
+  fi
+])
+
+# Expands to a C program that can be used to test for simultaneous support
+# of 'long long' and 'unsigned long long'. We don't want to say that
+# 'long long' is available if 'unsigned long long' is not, or vice versa,
+# because too many programs rely on the symmetry between signed and unsigned
+# integer types (excluding 'bool').
+AC_DEFUN([_AC_TYPE_LONG_LONG_SNIPPET],
+[
+  AC_LANG_PROGRAM(
+    [[/* For now, do not test the preprocessor; as of 2007 there are too many
+         implementations with broken preprocessors.  Perhaps this can
+         be revisited in 2012.  In the meantime, code should not expect
+         #if to work with literals wider than 32 bits.  */
+      /* Test literals.  */
+      long long int ll = 9223372036854775807ll;
+      long long int nll = -9223372036854775807LL;
+      unsigned long long int ull = 18446744073709551615ULL;
+      /* Test constant expressions.   */
+      typedef int a[((-9223372036854775807LL < 0 && 0 < 9223372036854775807ll)
+                     ? 1 : -1)];
+      typedef int b[(18446744073709551615ULL <= (unsigned long long int) -1
+                     ? 1 : -1)];
+      int i = 63;]],
+    [[/* Test availability of runtime routines for shift and division.  */
+      long long int llmax = 9223372036854775807ll;
+      unsigned long long int ullmax = 18446744073709551615ull;
+      return ((ll << 63) | (ll >> 63) | (ll < i) | (ll > i)
+              | (llmax / ll) | (llmax % ll)
+              | (ull << 63) | (ull >> 63) | (ull << i) | (ull >> i)
+              | (ullmax / ull) | (ullmax % ull));]])
+])
diff --git a/m4-gl/minmax.m4 b/m4-gl/minmax.m4
new file mode 100644
index 0000000..1e0d30b
--- /dev/null
+++ b/m4-gl/minmax.m4
@@ -0,0 +1,44 @@
+# minmax.m4 serial 4
+dnl Copyright (C) 2005, 2009-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_PREREQ([2.53])
+
+AC_DEFUN([gl_MINMAX],
+[
+  AC_REQUIRE([gl_PREREQ_MINMAX])
+])
+
+# Prerequisites of lib/minmax.h.
+AC_DEFUN([gl_PREREQ_MINMAX],
+[
+  gl_MINMAX_IN_HEADER([limits.h])
+  gl_MINMAX_IN_HEADER([sys/param.h])
+])
+
+dnl gl_MINMAX_IN_HEADER(HEADER)
+dnl The parameter has to be a literal header name; it cannot be macro,
+dnl nor a shell variable. (Because autoheader collects only AC_DEFINE
+dnl invocations with a literal macro name.)
+AC_DEFUN([gl_MINMAX_IN_HEADER],
+[
+  m4_pushdef([header], AS_TR_SH([$1]))
+  m4_pushdef([HEADER], AS_TR_CPP([$1]))
+  AC_CACHE_CHECK([whether <$1> defines MIN and MAX],
+    [gl_cv_minmax_in_]header,
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#include <$1>
+            int x = MIN (42, 17);]],
+          [[]])],
+       [gl_cv_minmax_in_]header[=yes],
+       [gl_cv_minmax_in_]header[=no])])
+  if test $gl_cv_minmax_in_[]header = yes; then
+    AC_DEFINE([HAVE_MINMAX_IN_]HEADER, 1,
+      [Define to 1 if <$1> defines the MIN and MAX macros.])
+  fi
+  m4_popdef([HEADER])
+  m4_popdef([header])
+])
diff --git a/m4-gl/multiarch.m4 b/m4-gl/multiarch.m4
new file mode 100644
index 0000000..d48316e
--- /dev/null
+++ b/m4-gl/multiarch.m4
@@ -0,0 +1,62 @@
+# multiarch.m4 serial 7
+dnl Copyright (C) 2008-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+# Determine whether the compiler is or may be producing universal binaries.
+#
+# On Mac OS X 10.5 and later systems, the user can create libraries and
+# executables that work on multiple system types--known as "fat" or
+# "universal" binaries--by specifying multiple '-arch' options to the
+# compiler but only a single '-arch' option to the preprocessor.  Like
+# this:
+#
+#     ./configure CC="gcc -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
+#                 CXX="g++ -arch i386 -arch x86_64 -arch ppc -arch ppc64" \
+#                 CPP="gcc -E" CXXCPP="g++ -E"
+#
+# Detect this situation and set APPLE_UNIVERSAL_BUILD accordingly.
+
+AC_DEFUN_ONCE([gl_MULTIARCH],
+[
+  dnl Code similar to autoconf-2.63 AC_C_BIGENDIAN.
+  gl_cv_c_multiarch=no
+  AC_COMPILE_IFELSE(
+    [AC_LANG_SOURCE(
+      [[#ifndef __APPLE_CC__
+         not a universal capable compiler
+        #endif
+        typedef int dummy;
+      ]])],
+    [
+     dnl Check for potential -arch flags.  It is not universal unless
+     dnl there are at least two -arch flags with different values.
+     arch=
+     prev=
+     for word in ${CC} ${CFLAGS} ${CPPFLAGS} ${LDFLAGS}; do
+       if test -n "$prev"; then
+         case $word in
+           i?86 | x86_64 | ppc | ppc64)
+             if test -z "$arch" || test "$arch" = "$word"; then
+               arch="$word"
+             else
+               gl_cv_c_multiarch=yes
+             fi
+             ;;
+         esac
+         prev=
+       else
+         if test "x$word" = "x-arch"; then
+           prev=arch
+         fi
+       fi
+     done
+    ])
+  if test $gl_cv_c_multiarch = yes; then
+    APPLE_UNIVERSAL_BUILD=1
+  else
+    APPLE_UNIVERSAL_BUILD=0
+  fi
+  AC_SUBST([APPLE_UNIVERSAL_BUILD])
+])
diff --git a/m4-gl/off_t.m4 b/m4-gl/off_t.m4
new file mode 100644
index 0000000..711a2d4
--- /dev/null
+++ b/m4-gl/off_t.m4
@@ -0,0 +1,18 @@
+# off_t.m4 serial 1
+dnl Copyright (C) 2012-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl Check whether to override the 'off_t' type.
+dnl Set WINDOWS_64_BIT_OFF_T.
+
+AC_DEFUN([gl_TYPE_OFF_T],
+[
+  m4_ifdef([gl_LARGEFILE], [
+    AC_REQUIRE([gl_LARGEFILE])
+  ], [
+    WINDOWS_64_BIT_OFF_T=0
+  ])
+  AC_SUBST([WINDOWS_64_BIT_OFF_T])
+])
diff --git a/m4-gl/ssize_t.m4 b/m4-gl/ssize_t.m4
new file mode 100644
index 0000000..38bcee1
--- /dev/null
+++ b/m4-gl/ssize_t.m4
@@ -0,0 +1,23 @@
+# ssize_t.m4 serial 5 (gettext-0.18.2)
+dnl Copyright (C) 2001-2003, 2006, 2010-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+dnl Test whether ssize_t is defined.
+
+AC_DEFUN([gt_TYPE_SSIZE_T],
+[
+  AC_CACHE_CHECK([for ssize_t], [gt_cv_ssize_t],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#include <sys/types.h>]],
+          [[int x = sizeof (ssize_t *) + sizeof (ssize_t);
+            return !x;]])],
+       [gt_cv_ssize_t=yes], [gt_cv_ssize_t=no])])
+  if test $gt_cv_ssize_t = no; then
+    AC_DEFINE([ssize_t], [int],
+              [Define as a signed type of the same size as size_t.])
+  fi
+])
diff --git a/m4-gl/stddef_h.m4 b/m4-gl/stddef_h.m4
new file mode 100644
index 0000000..979e3cf
--- /dev/null
+++ b/m4-gl/stddef_h.m4
@@ -0,0 +1,72 @@
+dnl A placeholder for <stddef.h>, for platforms that have issues.
+# stddef_h.m4 serial 6
+dnl Copyright (C) 2009-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_STDDEF_H],
+[
+  AC_REQUIRE([gl_STDDEF_H_DEFAULTS])
+  AC_REQUIRE([gt_TYPE_WCHAR_T])
+  STDDEF_H=
+
+  dnl Test whether the type max_align_t exists and whether its alignment
+  dnl "is as great as is supported by the implementation in all contexts".
+  AC_CACHE_CHECK([for good max_align_t],
+    [gl_cv_type_max_align_t],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#include <stddef.h>
+            unsigned int s = sizeof (max_align_t);
+            #if defined __GNUC__ || defined __IBM__ALIGNOF__
+            int check1[2 * (__alignof__ (double) <= __alignof__ (max_align_t)) - 1];
+            int check2[2 * (__alignof__ (long double) <= __alignof__ (max_align_t)) - 1];
+            #endif
+          ]])],
+       [gl_cv_type_max_align_t=yes],
+       [gl_cv_type_max_align_t=no])
+    ])
+  if test $gl_cv_type_max_align_t = no; then
+    HAVE_MAX_ALIGN_T=0
+    STDDEF_H=stddef.h
+  fi
+
+  if test $gt_cv_c_wchar_t = no; then
+    HAVE_WCHAR_T=0
+    STDDEF_H=stddef.h
+  fi
+
+  AC_CACHE_CHECK([whether NULL can be used in arbitrary expressions],
+    [gl_cv_decl_null_works],
+    [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stddef.h>
+      int test[2 * (sizeof NULL == sizeof (void *)) -1];
+]])],
+      [gl_cv_decl_null_works=yes],
+      [gl_cv_decl_null_works=no])])
+  if test $gl_cv_decl_null_works = no; then
+    REPLACE_NULL=1
+    STDDEF_H=stddef.h
+  fi
+
+  AC_SUBST([STDDEF_H])
+  AM_CONDITIONAL([GL_GENERATE_STDDEF_H], [test -n "$STDDEF_H"])
+  if test -n "$STDDEF_H"; then
+    gl_NEXT_HEADERS([stddef.h])
+  fi
+])
+
+AC_DEFUN([gl_STDDEF_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_STDDEF_H_DEFAULTS])
+  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
+])
+
+AC_DEFUN([gl_STDDEF_H_DEFAULTS],
+[
+  dnl Assume proper GNU behavior unless another module says otherwise.
+  REPLACE_NULL=0;                AC_SUBST([REPLACE_NULL])
+  HAVE_MAX_ALIGN_T=1;            AC_SUBST([HAVE_MAX_ALIGN_T])
+  HAVE_WCHAR_T=1;                AC_SUBST([HAVE_WCHAR_T])
+])
diff --git a/m4-gl/stdint.m4 b/m4-gl/stdint.m4
new file mode 100644
index 0000000..11d8e8e
--- /dev/null
+++ b/m4-gl/stdint.m4
@@ -0,0 +1,544 @@
+# stdint.m4 serial 53
+dnl Copyright (C) 2001-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Paul Eggert and Bruno Haible.
+dnl Test whether <stdint.h> is supported or must be substituted.
+
+AC_PREREQ([2.61])
+
+AC_DEFUN_ONCE([gl_STDINT_H],
+[
+  AC_PREREQ([2.59])dnl
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+
+  AC_REQUIRE([gl_LIMITS_H])
+  AC_REQUIRE([gt_TYPE_WINT_T])
+
+  dnl Check for long long int and unsigned long long int.
+  AC_REQUIRE([AC_TYPE_LONG_LONG_INT])
+  if test $ac_cv_type_long_long_int = yes; then
+    HAVE_LONG_LONG_INT=1
+  else
+    HAVE_LONG_LONG_INT=0
+  fi
+  AC_SUBST([HAVE_LONG_LONG_INT])
+  AC_REQUIRE([AC_TYPE_UNSIGNED_LONG_LONG_INT])
+  if test $ac_cv_type_unsigned_long_long_int = yes; then
+    HAVE_UNSIGNED_LONG_LONG_INT=1
+  else
+    HAVE_UNSIGNED_LONG_LONG_INT=0
+  fi
+  AC_SUBST([HAVE_UNSIGNED_LONG_LONG_INT])
+
+  dnl Check for <wchar.h>, in the same way as gl_WCHAR_H does.
+  AC_CHECK_HEADERS_ONCE([wchar.h])
+  if test $ac_cv_header_wchar_h = yes; then
+    HAVE_WCHAR_H=1
+  else
+    HAVE_WCHAR_H=0
+  fi
+  AC_SUBST([HAVE_WCHAR_H])
+
+  dnl Check for <inttypes.h>.
+  dnl AC_INCLUDES_DEFAULT defines $ac_cv_header_inttypes_h.
+  if test $ac_cv_header_inttypes_h = yes; then
+    HAVE_INTTYPES_H=1
+  else
+    HAVE_INTTYPES_H=0
+  fi
+  AC_SUBST([HAVE_INTTYPES_H])
+
+  dnl Check for <sys/types.h>.
+  dnl AC_INCLUDES_DEFAULT defines $ac_cv_header_sys_types_h.
+  if test $ac_cv_header_sys_types_h = yes; then
+    HAVE_SYS_TYPES_H=1
+  else
+    HAVE_SYS_TYPES_H=0
+  fi
+  AC_SUBST([HAVE_SYS_TYPES_H])
+
+  gl_CHECK_NEXT_HEADERS([stdint.h])
+  if test $ac_cv_header_stdint_h = yes; then
+    HAVE_STDINT_H=1
+  else
+    HAVE_STDINT_H=0
+  fi
+  AC_SUBST([HAVE_STDINT_H])
+
+  dnl Now see whether we need a substitute <stdint.h>.
+  if test $ac_cv_header_stdint_h = yes; then
+    AC_CACHE_CHECK([whether stdint.h conforms to C99],
+      [gl_cv_header_working_stdint_h],
+      [gl_cv_header_working_stdint_h=no
+       AC_COMPILE_IFELSE([
+         AC_LANG_PROGRAM([[
+#define _GL_JUST_INCLUDE_SYSTEM_STDINT_H 1 /* work if build isn't clean */
+#define __STDC_CONSTANT_MACROS 1
+#define __STDC_LIMIT_MACROS 1
+#include <stdint.h>
+/* Dragonfly defines WCHAR_MIN, WCHAR_MAX only in <wchar.h>.  */
+#if !(defined WCHAR_MIN && defined WCHAR_MAX)
+#error "WCHAR_MIN, WCHAR_MAX not defined in <stdint.h>"
+#endif
+]
+gl_STDINT_INCLUDES
+[
+#ifdef INT8_MAX
+int8_t a1 = INT8_MAX;
+int8_t a1min = INT8_MIN;
+#endif
+#ifdef INT16_MAX
+int16_t a2 = INT16_MAX;
+int16_t a2min = INT16_MIN;
+#endif
+#ifdef INT32_MAX
+int32_t a3 = INT32_MAX;
+int32_t a3min = INT32_MIN;
+#endif
+#ifdef INT64_MAX
+int64_t a4 = INT64_MAX;
+int64_t a4min = INT64_MIN;
+#endif
+#ifdef UINT8_MAX
+uint8_t b1 = UINT8_MAX;
+#else
+typedef int b1[(unsigned char) -1 != 255 ? 1 : -1];
+#endif
+#ifdef UINT16_MAX
+uint16_t b2 = UINT16_MAX;
+#endif
+#ifdef UINT32_MAX
+uint32_t b3 = UINT32_MAX;
+#endif
+#ifdef UINT64_MAX
+uint64_t b4 = UINT64_MAX;
+#endif
+int_least8_t c1 = INT8_C (0x7f);
+int_least8_t c1max = INT_LEAST8_MAX;
+int_least8_t c1min = INT_LEAST8_MIN;
+int_least16_t c2 = INT16_C (0x7fff);
+int_least16_t c2max = INT_LEAST16_MAX;
+int_least16_t c2min = INT_LEAST16_MIN;
+int_least32_t c3 = INT32_C (0x7fffffff);
+int_least32_t c3max = INT_LEAST32_MAX;
+int_least32_t c3min = INT_LEAST32_MIN;
+int_least64_t c4 = INT64_C (0x7fffffffffffffff);
+int_least64_t c4max = INT_LEAST64_MAX;
+int_least64_t c4min = INT_LEAST64_MIN;
+uint_least8_t d1 = UINT8_C (0xff);
+uint_least8_t d1max = UINT_LEAST8_MAX;
+uint_least16_t d2 = UINT16_C (0xffff);
+uint_least16_t d2max = UINT_LEAST16_MAX;
+uint_least32_t d3 = UINT32_C (0xffffffff);
+uint_least32_t d3max = UINT_LEAST32_MAX;
+uint_least64_t d4 = UINT64_C (0xffffffffffffffff);
+uint_least64_t d4max = UINT_LEAST64_MAX;
+int_fast8_t e1 = INT_FAST8_MAX;
+int_fast8_t e1min = INT_FAST8_MIN;
+int_fast16_t e2 = INT_FAST16_MAX;
+int_fast16_t e2min = INT_FAST16_MIN;
+int_fast32_t e3 = INT_FAST32_MAX;
+int_fast32_t e3min = INT_FAST32_MIN;
+int_fast64_t e4 = INT_FAST64_MAX;
+int_fast64_t e4min = INT_FAST64_MIN;
+uint_fast8_t f1 = UINT_FAST8_MAX;
+uint_fast16_t f2 = UINT_FAST16_MAX;
+uint_fast32_t f3 = UINT_FAST32_MAX;
+uint_fast64_t f4 = UINT_FAST64_MAX;
+#ifdef INTPTR_MAX
+intptr_t g = INTPTR_MAX;
+intptr_t gmin = INTPTR_MIN;
+#endif
+#ifdef UINTPTR_MAX
+uintptr_t h = UINTPTR_MAX;
+#endif
+intmax_t i = INTMAX_MAX;
+uintmax_t j = UINTMAX_MAX;
+
+/* Check that SIZE_MAX has the correct type, if possible.  */
+#if 201112 <= __STDC_VERSION__
+int k = _Generic (SIZE_MAX, size_t: 0);
+#elif (2 <= __GNUC__ || defined __IBM__TYPEOF__ \
+       || (0x5110 <= __SUNPRO_C && !__STDC__))
+extern size_t k;
+extern __typeof__ (SIZE_MAX) k;
+#endif
+
+#include <limits.h> /* for CHAR_BIT */
+#define TYPE_MINIMUM(t) \
+  ((t) ((t) 0 < (t) -1 ? (t) 0 : ~ TYPE_MAXIMUM (t)))
+#define TYPE_MAXIMUM(t) \
+  ((t) ((t) 0 < (t) -1 \
+        ? (t) -1 \
+        : ((((t) 1 << (sizeof (t) * CHAR_BIT - 2)) - 1) * 2 + 1)))
+struct s {
+  int check_PTRDIFF:
+      PTRDIFF_MIN == TYPE_MINIMUM (ptrdiff_t)
+      && PTRDIFF_MAX == TYPE_MAXIMUM (ptrdiff_t)
+      ? 1 : -1;
+  /* Detect bug in FreeBSD 6.0 / ia64.  */
+  int check_SIG_ATOMIC:
+      SIG_ATOMIC_MIN == TYPE_MINIMUM (sig_atomic_t)
+      && SIG_ATOMIC_MAX == TYPE_MAXIMUM (sig_atomic_t)
+      ? 1 : -1;
+  int check_SIZE: SIZE_MAX == TYPE_MAXIMUM (size_t) ? 1 : -1;
+  int check_WCHAR:
+      WCHAR_MIN == TYPE_MINIMUM (wchar_t)
+      && WCHAR_MAX == TYPE_MAXIMUM (wchar_t)
+      ? 1 : -1;
+  /* Detect bug in mingw.  */
+  int check_WINT:
+      WINT_MIN == TYPE_MINIMUM (wint_t)
+      && WINT_MAX == TYPE_MAXIMUM (wint_t)
+      ? 1 : -1;
+
+  /* Detect bugs in glibc 2.4 and Solaris 10 stdint.h, among others.  */
+  int check_UINT8_C:
+        (-1 < UINT8_C (0)) == (-1 < (uint_least8_t) 0) ? 1 : -1;
+  int check_UINT16_C:
+        (-1 < UINT16_C (0)) == (-1 < (uint_least16_t) 0) ? 1 : -1;
+
+  /* Detect bugs in OpenBSD 3.9 stdint.h.  */
+#ifdef UINT8_MAX
+  int check_uint8: (uint8_t) -1 == UINT8_MAX ? 1 : -1;
+#endif
+#ifdef UINT16_MAX
+  int check_uint16: (uint16_t) -1 == UINT16_MAX ? 1 : -1;
+#endif
+#ifdef UINT32_MAX
+  int check_uint32: (uint32_t) -1 == UINT32_MAX ? 1 : -1;
+#endif
+#ifdef UINT64_MAX
+  int check_uint64: (uint64_t) -1 == UINT64_MAX ? 1 : -1;
+#endif
+  int check_uint_least8: (uint_least8_t) -1 == UINT_LEAST8_MAX ? 1 : -1;
+  int check_uint_least16: (uint_least16_t) -1 == UINT_LEAST16_MAX ? 1 : -1;
+  int check_uint_least32: (uint_least32_t) -1 == UINT_LEAST32_MAX ? 1 : -1;
+  int check_uint_least64: (uint_least64_t) -1 == UINT_LEAST64_MAX ? 1 : -1;
+  int check_uint_fast8: (uint_fast8_t) -1 == UINT_FAST8_MAX ? 1 : -1;
+  int check_uint_fast16: (uint_fast16_t) -1 == UINT_FAST16_MAX ? 1 : -1;
+  int check_uint_fast32: (uint_fast32_t) -1 == UINT_FAST32_MAX ? 1 : -1;
+  int check_uint_fast64: (uint_fast64_t) -1 == UINT_FAST64_MAX ? 1 : -1;
+  int check_uintptr: (uintptr_t) -1 == UINTPTR_MAX ? 1 : -1;
+  int check_uintmax: (uintmax_t) -1 == UINTMAX_MAX ? 1 : -1;
+  int check_size: (size_t) -1 == SIZE_MAX ? 1 : -1;
+};
+         ]])],
+         [dnl Determine whether the various *_MIN, *_MAX macros are usable
+          dnl in preprocessor expression. We could do it by compiling a test
+          dnl program for each of these macros. It is faster to run a program
+          dnl that inspects the macro expansion.
+          dnl This detects a bug on HP-UX 11.23/ia64.
+          AC_RUN_IFELSE([
+            AC_LANG_PROGRAM([[
+#define _GL_JUST_INCLUDE_SYSTEM_STDINT_H 1 /* work if build isn't clean */
+#define __STDC_CONSTANT_MACROS 1
+#define __STDC_LIMIT_MACROS 1
+#include <stdint.h>
+]
+gl_STDINT_INCLUDES
+[
+#include <stdio.h>
+#include <string.h>
+#define MVAL(macro) MVAL1(macro)
+#define MVAL1(expression) #expression
+static const char *macro_values[] =
+  {
+#ifdef INT8_MAX
+    MVAL (INT8_MAX),
+#endif
+#ifdef INT16_MAX
+    MVAL (INT16_MAX),
+#endif
+#ifdef INT32_MAX
+    MVAL (INT32_MAX),
+#endif
+#ifdef INT64_MAX
+    MVAL (INT64_MAX),
+#endif
+#ifdef UINT8_MAX
+    MVAL (UINT8_MAX),
+#endif
+#ifdef UINT16_MAX
+    MVAL (UINT16_MAX),
+#endif
+#ifdef UINT32_MAX
+    MVAL (UINT32_MAX),
+#endif
+#ifdef UINT64_MAX
+    MVAL (UINT64_MAX),
+#endif
+    NULL
+  };
+]], [[
+  const char **mv;
+  for (mv = macro_values; *mv != NULL; mv++)
+    {
+      const char *value = *mv;
+      /* Test whether it looks like a cast expression.  */
+      if (strncmp (value, "((unsigned int)"/*)*/, 15) == 0
+          || strncmp (value, "((unsigned short)"/*)*/, 17) == 0
+          || strncmp (value, "((unsigned char)"/*)*/, 16) == 0
+          || strncmp (value, "((int)"/*)*/, 6) == 0
+          || strncmp (value, "((signed short)"/*)*/, 15) == 0
+          || strncmp (value, "((signed char)"/*)*/, 14) == 0)
+        return mv - macro_values + 1;
+    }
+  return 0;
+]])],
+              [gl_cv_header_working_stdint_h=yes],
+              [],
+              [case "$host_os" in
+                         # Guess yes on native Windows.
+                 mingw*) gl_cv_header_working_stdint_h="guessing yes" ;;
+                         # In general, assume it works.
+                 *)      gl_cv_header_working_stdint_h="guessing yes" ;;
+               esac
+              ])
+         ])
+      ])
+  fi
+
+  HAVE_C99_STDINT_H=0
+  HAVE_SYS_BITYPES_H=0
+  HAVE_SYS_INTTYPES_H=0
+  STDINT_H=stdint.h
+  case "$gl_cv_header_working_stdint_h" in
+    *yes)
+      HAVE_C99_STDINT_H=1
+      dnl Now see whether the system <stdint.h> works without
+      dnl __STDC_CONSTANT_MACROS/__STDC_LIMIT_MACROS defined.
+      AC_CACHE_CHECK([whether stdint.h predates C++11],
+        [gl_cv_header_stdint_predates_cxx11_h],
+        [gl_cv_header_stdint_predates_cxx11_h=yes
+         AC_COMPILE_IFELSE([
+           AC_LANG_PROGRAM([[
+#define _GL_JUST_INCLUDE_SYSTEM_STDINT_H 1 /* work if build isn't clean */
+#include <stdint.h>
+]
+gl_STDINT_INCLUDES
+[
+intmax_t im = INTMAX_MAX;
+int32_t i32 = INT32_C (0x7fffffff);
+           ]])],
+           [gl_cv_header_stdint_predates_cxx11_h=no])])
+
+      if test "$gl_cv_header_stdint_predates_cxx11_h" = yes; then
+        AC_DEFINE([__STDC_CONSTANT_MACROS], [1],
+                  [Define to 1 if the system <stdint.h> predates C++11.])
+        AC_DEFINE([__STDC_LIMIT_MACROS], [1],
+                  [Define to 1 if the system <stdint.h> predates C++11.])
+      fi
+      AC_CACHE_CHECK([whether stdint.h has UINTMAX_WIDTH etc.],
+        [gl_cv_header_stdint_width],
+        [gl_cv_header_stdint_width=no
+         AC_COMPILE_IFELSE(
+           [AC_LANG_PROGRAM([[
+              /* Work if build is not clean.  */
+              #define _GL_JUST_INCLUDE_SYSTEM_STDINT_H 1
+              #ifndef __STDC_WANT_IEC_60559_BFP_EXT__
+               #define __STDC_WANT_IEC_60559_BFP_EXT__ 1
+              #endif
+              #include <stdint.h>
+              ]gl_STDINT_INCLUDES[
+              int iw = UINTMAX_WIDTH;
+              ]])],
+           [gl_cv_header_stdint_width=yes])])
+      if test "$gl_cv_header_stdint_width" = yes; then
+        STDINT_H=
+      fi
+      ;;
+    *)
+      dnl Check for <sys/inttypes.h>, and for
+      dnl <sys/bitypes.h> (used in Linux libc4 >= 4.6.7 and libc5).
+      AC_CHECK_HEADERS([sys/inttypes.h sys/bitypes.h])
+      if test $ac_cv_header_sys_inttypes_h = yes; then
+        HAVE_SYS_INTTYPES_H=1
+      fi
+      if test $ac_cv_header_sys_bitypes_h = yes; then
+        HAVE_SYS_BITYPES_H=1
+      fi
+      gl_STDINT_TYPE_PROPERTIES
+      ;;
+  esac
+
+  dnl The substitute stdint.h needs the substitute limit.h's _GL_INTEGER_WIDTH.
+  gl_REPLACE_LIMITS_H
+
+  AC_SUBST([HAVE_C99_STDINT_H])
+  AC_SUBST([HAVE_SYS_BITYPES_H])
+  AC_SUBST([HAVE_SYS_INTTYPES_H])
+  AC_SUBST([STDINT_H])
+  AM_CONDITIONAL([GL_GENERATE_STDINT_H], [test -n "$STDINT_H"])
+])
+
+dnl gl_STDINT_BITSIZEOF(TYPES, INCLUDES)
+dnl Determine the size of each of the given types in bits.
+AC_DEFUN([gl_STDINT_BITSIZEOF],
+[
+  dnl Use a shell loop, to avoid bloating configure, and
+  dnl - extra AH_TEMPLATE calls, so that autoheader knows what to put into
+  dnl   config.h.in,
+  dnl - extra AC_SUBST calls, so that the right substitutions are made.
+  m4_foreach_w([gltype], [$1],
+    [AH_TEMPLATE([BITSIZEOF_]m4_translit(gltype,[abcdefghijklmnopqrstuvwxyz ],[ABCDEFGHIJKLMNOPQRSTUVWXYZ_]),
+       [Define to the number of bits in type ']gltype['.])])
+  for gltype in $1 ; do
+    AC_CACHE_CHECK([for bit size of $gltype], [gl_cv_bitsizeof_${gltype}],
+      [AC_COMPUTE_INT([result], [sizeof ($gltype) * CHAR_BIT],
+         [$2
+#include <limits.h>], [result=unknown])
+       eval gl_cv_bitsizeof_${gltype}=\$result
+      ])
+    eval result=\$gl_cv_bitsizeof_${gltype}
+    if test $result = unknown; then
+      dnl Use a nonempty default, because some compilers, such as IRIX 5 cc,
+      dnl do a syntax check even on unused #if conditions and give an error
+      dnl on valid C code like this:
+      dnl   #if 0
+      dnl   # if  > 32
+      dnl   # endif
+      dnl   #endif
+      result=0
+    fi
+    GLTYPE=`echo "$gltype" | tr 'abcdefghijklmnopqrstuvwxyz ' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ_'`
+    AC_DEFINE_UNQUOTED([BITSIZEOF_${GLTYPE}], [$result])
+    eval BITSIZEOF_${GLTYPE}=\$result
+  done
+  m4_foreach_w([gltype], [$1],
+    [AC_SUBST([BITSIZEOF_]m4_translit(gltype,[abcdefghijklmnopqrstuvwxyz ],[ABCDEFGHIJKLMNOPQRSTUVWXYZ_]))])
+])
+
+dnl gl_CHECK_TYPES_SIGNED(TYPES, INCLUDES)
+dnl Determine the signedness of each of the given types.
+dnl Define HAVE_SIGNED_TYPE if type is signed.
+AC_DEFUN([gl_CHECK_TYPES_SIGNED],
+[
+  dnl Use a shell loop, to avoid bloating configure, and
+  dnl - extra AH_TEMPLATE calls, so that autoheader knows what to put into
+  dnl   config.h.in,
+  dnl - extra AC_SUBST calls, so that the right substitutions are made.
+  m4_foreach_w([gltype], [$1],
+    [AH_TEMPLATE([HAVE_SIGNED_]m4_translit(gltype,[abcdefghijklmnopqrstuvwxyz ],[ABCDEFGHIJKLMNOPQRSTUVWXYZ_]),
+       [Define to 1 if ']gltype[' is a signed integer type.])])
+  for gltype in $1 ; do
+    AC_CACHE_CHECK([whether $gltype is signed], [gl_cv_type_${gltype}_signed],
+      [AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM([$2[
+            int verify[2 * (($gltype) -1 < ($gltype) 0) - 1];]])],
+         result=yes, result=no)
+       eval gl_cv_type_${gltype}_signed=\$result
+      ])
+    eval result=\$gl_cv_type_${gltype}_signed
+    GLTYPE=`echo $gltype | tr 'abcdefghijklmnopqrstuvwxyz ' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ_'`
+    if test "$result" = yes; then
+      AC_DEFINE_UNQUOTED([HAVE_SIGNED_${GLTYPE}], [1])
+      eval HAVE_SIGNED_${GLTYPE}=1
+    else
+      eval HAVE_SIGNED_${GLTYPE}=0
+    fi
+  done
+  m4_foreach_w([gltype], [$1],
+    [AC_SUBST([HAVE_SIGNED_]m4_translit(gltype,[abcdefghijklmnopqrstuvwxyz ],[ABCDEFGHIJKLMNOPQRSTUVWXYZ_]))])
+])
+
+dnl gl_INTEGER_TYPE_SUFFIX(TYPES, INCLUDES)
+dnl Determine the suffix to use for integer constants of the given types.
+dnl Define t_SUFFIX for each such type.
+AC_DEFUN([gl_INTEGER_TYPE_SUFFIX],
+[
+  dnl Use a shell loop, to avoid bloating configure, and
+  dnl - extra AH_TEMPLATE calls, so that autoheader knows what to put into
+  dnl   config.h.in,
+  dnl - extra AC_SUBST calls, so that the right substitutions are made.
+  m4_foreach_w([gltype], [$1],
+    [AH_TEMPLATE(m4_translit(gltype,[abcdefghijklmnopqrstuvwxyz ],[ABCDEFGHIJKLMNOPQRSTUVWXYZ_])[_SUFFIX],
+       [Define to l, ll, u, ul, ull, etc., as suitable for
+        constants of type ']gltype['.])])
+  for gltype in $1 ; do
+    AC_CACHE_CHECK([for $gltype integer literal suffix],
+      [gl_cv_type_${gltype}_suffix],
+      [eval gl_cv_type_${gltype}_suffix=no
+       eval result=\$gl_cv_type_${gltype}_signed
+       if test "$result" = yes; then
+         glsufu=
+       else
+         glsufu=u
+       fi
+       for glsuf in "$glsufu" ${glsufu}l ${glsufu}ll ${glsufu}i64; do
+         case $glsuf in
+           '')  gltype1='int';;
+           l)   gltype1='long int';;
+           ll)  gltype1='long long int';;
+           i64) gltype1='__int64';;
+           u)   gltype1='unsigned int';;
+           ul)  gltype1='unsigned long int';;
+           ull) gltype1='unsigned long long int';;
+           ui64)gltype1='unsigned __int64';;
+         esac
+         AC_COMPILE_IFELSE(
+           [AC_LANG_PROGRAM([$2[
+              extern $gltype foo;
+              extern $gltype1 foo;]])],
+           [eval gl_cv_type_${gltype}_suffix=\$glsuf])
+         eval result=\$gl_cv_type_${gltype}_suffix
+         test "$result" != no && break
+       done])
+    GLTYPE=`echo $gltype | tr 'abcdefghijklmnopqrstuvwxyz ' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ_'`
+    eval result=\$gl_cv_type_${gltype}_suffix
+    test "$result" = no && result=
+    eval ${GLTYPE}_SUFFIX=\$result
+    AC_DEFINE_UNQUOTED([${GLTYPE}_SUFFIX], [$result])
+  done
+  m4_foreach_w([gltype], [$1],
+    [AC_SUBST(m4_translit(gltype,[abcdefghijklmnopqrstuvwxyz ],[ABCDEFGHIJKLMNOPQRSTUVWXYZ_])[_SUFFIX])])
+])
+
+dnl gl_STDINT_INCLUDES
+AC_DEFUN([gl_STDINT_INCLUDES],
+[[
+  /* BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+     included before <wchar.h>.  */
+  #include <stddef.h>
+  #include <signal.h>
+  #if HAVE_WCHAR_H
+  # include <stdio.h>
+  # include <time.h>
+  # include <wchar.h>
+  #endif
+]])
+
+dnl gl_STDINT_TYPE_PROPERTIES
+dnl Compute HAVE_SIGNED_t, BITSIZEOF_t and t_SUFFIX, for all the types t
+dnl of interest to stdint.in.h.
+AC_DEFUN([gl_STDINT_TYPE_PROPERTIES],
+[
+  AC_REQUIRE([gl_MULTIARCH])
+  if test $APPLE_UNIVERSAL_BUILD = 0; then
+    gl_STDINT_BITSIZEOF([ptrdiff_t size_t],
+      [gl_STDINT_INCLUDES])
+  fi
+  gl_STDINT_BITSIZEOF([sig_atomic_t wchar_t wint_t],
+    [gl_STDINT_INCLUDES])
+  gl_CHECK_TYPES_SIGNED([sig_atomic_t wchar_t wint_t],
+    [gl_STDINT_INCLUDES])
+  gl_cv_type_ptrdiff_t_signed=yes
+  gl_cv_type_size_t_signed=no
+  if test $APPLE_UNIVERSAL_BUILD = 0; then
+    gl_INTEGER_TYPE_SUFFIX([ptrdiff_t size_t],
+      [gl_STDINT_INCLUDES])
+  fi
+  gl_INTEGER_TYPE_SUFFIX([sig_atomic_t wchar_t wint_t],
+    [gl_STDINT_INCLUDES])
+
+  dnl If wint_t is smaller than 'int', it cannot satisfy the ISO C 99
+  dnl requirement that wint_t is "unchanged by default argument promotions".
+  dnl In this case gnulib's <wchar.h> and <wctype.h> override wint_t.
+  dnl Set the variable BITSIZEOF_WINT_T accordingly.
+  if test $GNULIB_OVERRIDES_WINT_T = 1; then
+    BITSIZEOF_WINT_T=32
+  fi
+])
diff --git a/m4-gl/string_h.m4 b/m4-gl/string_h.m4
new file mode 100644
index 0000000..0c0e3a7
--- /dev/null
+++ b/m4-gl/string_h.m4
@@ -0,0 +1,122 @@
+# Configure a GNU-like replacement for <string.h>.
+
+# Copyright (C) 2007-2019 Free Software Foundation, Inc.
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+# serial 22
+
+# Written by Paul Eggert.
+
+AC_DEFUN([gl_HEADER_STRING_H],
+[
+  dnl Use AC_REQUIRE here, so that the default behavior below is expanded
+  dnl once only, before all statements that occur in other macros.
+  AC_REQUIRE([gl_HEADER_STRING_H_BODY])
+])
+
+AC_DEFUN([gl_HEADER_STRING_H_BODY],
+[
+  AC_REQUIRE([AC_C_RESTRICT])
+  AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
+  gl_NEXT_HEADERS([string.h])
+
+  dnl Check for declarations of anything we want to poison if the
+  dnl corresponding gnulib module is not in use, and which is not
+  dnl guaranteed by C89.
+  gl_WARN_ON_USE_PREPARE([[#include <string.h>
+    ]],
+    [ffsl ffsll memmem mempcpy memrchr rawmemchr stpcpy stpncpy strchrnul
+     strdup strncat strndup strnlen strpbrk strsep strcasestr strtok_r
+     strerror_r strsignal strverscmp])
+])
+
+AC_DEFUN([gl_STRING_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
+  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
+  dnl Define it also as a C macro, for the benefit of the unit tests.
+  gl_MODULE_INDICATOR_FOR_TESTS([$1])
+])
+
+AC_DEFUN([gl_HEADER_STRING_H_DEFAULTS],
+[
+  GNULIB_EXPLICIT_BZERO=0; AC_SUBST([GNULIB_EXPLICIT_BZERO])
+  GNULIB_FFSL=0;        AC_SUBST([GNULIB_FFSL])
+  GNULIB_FFSLL=0;       AC_SUBST([GNULIB_FFSLL])
+  GNULIB_MEMCHR=0;      AC_SUBST([GNULIB_MEMCHR])
+  GNULIB_MEMMEM=0;      AC_SUBST([GNULIB_MEMMEM])
+  GNULIB_MEMPCPY=0;     AC_SUBST([GNULIB_MEMPCPY])
+  GNULIB_MEMRCHR=0;     AC_SUBST([GNULIB_MEMRCHR])
+  GNULIB_RAWMEMCHR=0;   AC_SUBST([GNULIB_RAWMEMCHR])
+  GNULIB_STPCPY=0;      AC_SUBST([GNULIB_STPCPY])
+  GNULIB_STPNCPY=0;     AC_SUBST([GNULIB_STPNCPY])
+  GNULIB_STRCHRNUL=0;   AC_SUBST([GNULIB_STRCHRNUL])
+  GNULIB_STRDUP=0;      AC_SUBST([GNULIB_STRDUP])
+  GNULIB_STRNCAT=0;     AC_SUBST([GNULIB_STRNCAT])
+  GNULIB_STRNDUP=0;     AC_SUBST([GNULIB_STRNDUP])
+  GNULIB_STRNLEN=0;     AC_SUBST([GNULIB_STRNLEN])
+  GNULIB_STRPBRK=0;     AC_SUBST([GNULIB_STRPBRK])
+  GNULIB_STRSEP=0;      AC_SUBST([GNULIB_STRSEP])
+  GNULIB_STRSTR=0;      AC_SUBST([GNULIB_STRSTR])
+  GNULIB_STRCASESTR=0;  AC_SUBST([GNULIB_STRCASESTR])
+  GNULIB_STRTOK_R=0;    AC_SUBST([GNULIB_STRTOK_R])
+  GNULIB_MBSLEN=0;      AC_SUBST([GNULIB_MBSLEN])
+  GNULIB_MBSNLEN=0;     AC_SUBST([GNULIB_MBSNLEN])
+  GNULIB_MBSCHR=0;      AC_SUBST([GNULIB_MBSCHR])
+  GNULIB_MBSRCHR=0;     AC_SUBST([GNULIB_MBSRCHR])
+  GNULIB_MBSSTR=0;      AC_SUBST([GNULIB_MBSSTR])
+  GNULIB_MBSCASECMP=0;  AC_SUBST([GNULIB_MBSCASECMP])
+  GNULIB_MBSNCASECMP=0; AC_SUBST([GNULIB_MBSNCASECMP])
+  GNULIB_MBSPCASECMP=0; AC_SUBST([GNULIB_MBSPCASECMP])
+  GNULIB_MBSCASESTR=0;  AC_SUBST([GNULIB_MBSCASESTR])
+  GNULIB_MBSCSPN=0;     AC_SUBST([GNULIB_MBSCSPN])
+  GNULIB_MBSPBRK=0;     AC_SUBST([GNULIB_MBSPBRK])
+  GNULIB_MBSSPN=0;      AC_SUBST([GNULIB_MBSSPN])
+  GNULIB_MBSSEP=0;      AC_SUBST([GNULIB_MBSSEP])
+  GNULIB_MBSTOK_R=0;    AC_SUBST([GNULIB_MBSTOK_R])
+  GNULIB_STRERROR=0;    AC_SUBST([GNULIB_STRERROR])
+  GNULIB_STRERROR_R=0;  AC_SUBST([GNULIB_STRERROR_R])
+  GNULIB_STRSIGNAL=0;   AC_SUBST([GNULIB_STRSIGNAL])
+  GNULIB_STRVERSCMP=0;  AC_SUBST([GNULIB_STRVERSCMP])
+  HAVE_MBSLEN=0;        AC_SUBST([HAVE_MBSLEN])
+  dnl Assume proper GNU behavior unless another module says otherwise.
+  HAVE_EXPLICIT_BZERO=1;        AC_SUBST([HAVE_EXPLICIT_BZERO])
+  HAVE_FFSL=1;                  AC_SUBST([HAVE_FFSL])
+  HAVE_FFSLL=1;                 AC_SUBST([HAVE_FFSLL])
+  HAVE_MEMCHR=1;                AC_SUBST([HAVE_MEMCHR])
+  HAVE_DECL_MEMMEM=1;           AC_SUBST([HAVE_DECL_MEMMEM])
+  HAVE_MEMPCPY=1;               AC_SUBST([HAVE_MEMPCPY])
+  HAVE_DECL_MEMRCHR=1;          AC_SUBST([HAVE_DECL_MEMRCHR])
+  HAVE_RAWMEMCHR=1;             AC_SUBST([HAVE_RAWMEMCHR])
+  HAVE_STPCPY=1;                AC_SUBST([HAVE_STPCPY])
+  HAVE_STPNCPY=1;               AC_SUBST([HAVE_STPNCPY])
+  HAVE_STRCHRNUL=1;             AC_SUBST([HAVE_STRCHRNUL])
+  HAVE_DECL_STRDUP=1;           AC_SUBST([HAVE_DECL_STRDUP])
+  HAVE_DECL_STRNDUP=1;          AC_SUBST([HAVE_DECL_STRNDUP])
+  HAVE_DECL_STRNLEN=1;          AC_SUBST([HAVE_DECL_STRNLEN])
+  HAVE_STRPBRK=1;               AC_SUBST([HAVE_STRPBRK])
+  HAVE_STRSEP=1;                AC_SUBST([HAVE_STRSEP])
+  HAVE_STRCASESTR=1;            AC_SUBST([HAVE_STRCASESTR])
+  HAVE_DECL_STRTOK_R=1;         AC_SUBST([HAVE_DECL_STRTOK_R])
+  HAVE_DECL_STRERROR_R=1;       AC_SUBST([HAVE_DECL_STRERROR_R])
+  HAVE_DECL_STRSIGNAL=1;        AC_SUBST([HAVE_DECL_STRSIGNAL])
+  HAVE_STRVERSCMP=1;            AC_SUBST([HAVE_STRVERSCMP])
+  REPLACE_MEMCHR=0;             AC_SUBST([REPLACE_MEMCHR])
+  REPLACE_MEMMEM=0;             AC_SUBST([REPLACE_MEMMEM])
+  REPLACE_STPNCPY=0;            AC_SUBST([REPLACE_STPNCPY])
+  REPLACE_STRCHRNUL=0;          AC_SUBST([REPLACE_STRCHRNUL])
+  REPLACE_STRDUP=0;             AC_SUBST([REPLACE_STRDUP])
+  REPLACE_STRNCAT=0;            AC_SUBST([REPLACE_STRNCAT])
+  REPLACE_STRNDUP=0;            AC_SUBST([REPLACE_STRNDUP])
+  REPLACE_STRNLEN=0;            AC_SUBST([REPLACE_STRNLEN])
+  REPLACE_STRSTR=0;             AC_SUBST([REPLACE_STRSTR])
+  REPLACE_STRCASESTR=0;         AC_SUBST([REPLACE_STRCASESTR])
+  REPLACE_STRTOK_R=0;           AC_SUBST([REPLACE_STRTOK_R])
+  REPLACE_STRERROR=0;           AC_SUBST([REPLACE_STRERROR])
+  REPLACE_STRERROR_R=0;         AC_SUBST([REPLACE_STRERROR_R])
+  REPLACE_STRSIGNAL=0;          AC_SUBST([REPLACE_STRSIGNAL])
+  UNDEFINE_STRTOK_R=0;          AC_SUBST([UNDEFINE_STRTOK_R])
+])
diff --git a/m4-gl/strverscmp.m4 b/m4-gl/strverscmp.m4
new file mode 100644
index 0000000..ec66cdf
--- /dev/null
+++ b/m4-gl/strverscmp.m4
@@ -0,0 +1,22 @@
+# strverscmp.m4 serial 8
+dnl Copyright (C) 2002, 2005-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_STRVERSCMP],
+[
+  dnl Persuade glibc <string.h> to declare strverscmp().
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
+  AC_REQUIRE([gl_HEADER_STRING_H_DEFAULTS])
+  AC_CHECK_FUNCS([strverscmp])
+  if test $ac_cv_func_strverscmp = no; then
+    HAVE_STRVERSCMP=0
+  fi
+])
+
+# Prerequisites of lib/strverscmp.c.
+AC_DEFUN([gl_PREREQ_STRVERSCMP], [
+  :
+])
diff --git a/m4-gl/sys_types_h.m4 b/m4-gl/sys_types_h.m4
new file mode 100644
index 0000000..be06559
--- /dev/null
+++ b/m4-gl/sys_types_h.m4
@@ -0,0 +1,60 @@
+# sys_types_h.m4 serial 9
+dnl Copyright (C) 2011-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN_ONCE([gl_SYS_TYPES_H],
+[
+  dnl Use sane struct stat types in OpenVMS 8.2 and later.
+  AC_DEFINE([_USE_STD_STAT], 1, [For standard stat data types on VMS.])
+
+  AC_REQUIRE([gl_SYS_TYPES_H_DEFAULTS])
+  gl_NEXT_HEADERS([sys/types.h])
+
+  dnl Ensure the type pid_t gets defined.
+  AC_REQUIRE([AC_TYPE_PID_T])
+
+  dnl Ensure the type mode_t gets defined.
+  AC_REQUIRE([AC_TYPE_MODE_T])
+
+  dnl Whether to override the 'off_t' type.
+  AC_REQUIRE([gl_TYPE_OFF_T])
+
+  dnl Whether to override the 'dev_t' and 'ino_t' types.
+  m4_ifdef([gl_WINDOWS_STAT_INODES], [
+    AC_REQUIRE([gl_WINDOWS_STAT_INODES])
+  ], [
+    WINDOWS_STAT_INODES=0
+  ])
+  AC_SUBST([WINDOWS_STAT_INODES])
+])
+
+AC_DEFUN([gl_SYS_TYPES_H_DEFAULTS],
+[
+])
+
+# This works around a buggy version in autoconf <= 2.69.
+# See <https://lists.gnu.org/r/autoconf/2016-08/msg00014.html>
+
+m4_version_prereq([2.70], [], [
+
+# This is taken from the following Autoconf patch:
+# https://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=e17a30e987d7ee695fb4294a82d987ec3dc9b974
+
+m4_undefine([AC_HEADER_MAJOR])
+AC_DEFUN([AC_HEADER_MAJOR],
+[AC_CHECK_HEADERS_ONCE([sys/types.h])
+AC_CHECK_HEADER([sys/mkdev.h],
+  [AC_DEFINE([MAJOR_IN_MKDEV], [1],
+    [Define to 1 if `major', `minor', and `makedev' are declared in
+     <mkdev.h>.])])
+if test $ac_cv_header_sys_mkdev_h = no; then
+  AC_CHECK_HEADER([sys/sysmacros.h],
+    [AC_DEFINE([MAJOR_IN_SYSMACROS], [1],
+      [Define to 1 if `major', `minor', and `makedev' are declared in
+       <sysmacros.h>.])])
+fi
+])
+
+])
diff --git a/m4-gl/valgrind-tests.m4 b/m4-gl/valgrind-tests.m4
new file mode 100644
index 0000000..ea138a1
--- /dev/null
+++ b/m4-gl/valgrind-tests.m4
@@ -0,0 +1,37 @@
+# valgrind-tests.m4 serial 4
+dnl Copyright (C) 2008-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Simon Josefsson
+
+# gl_VALGRIND_TESTS()
+# -------------------
+# Check if valgrind is available, and set VALGRIND to it if available.
+AC_DEFUN([gl_VALGRIND_TESTS],
+[
+  AC_ARG_ENABLE([valgrind-tests],
+    AS_HELP_STRING([--disable-valgrind-tests],
+                   [don't try to run self tests under valgrind]),
+    [opt_valgrind_tests=$enableval], [opt_valgrind_tests=yes])
+
+  # Run self-tests under valgrind?
+  if test "$opt_valgrind_tests" = "yes" && test "$cross_compiling" = no; then
+    AC_CHECK_PROGS([VALGRIND], [valgrind])
+
+    if test "$VALGRIND"; then
+      AC_CACHE_CHECK([for valgrind options for tests],
+        [gl_cv_opt_valgrind_tests],
+        [gl_cv_opt_valgrind_tests="-q --error-exitcode=1 --leak-check=full"
+         $VALGRIND $gl_valgrind_opts ls > /dev/null 2>&1 ||
+           gl_cv_opt_valgrind_tests=no])
+
+      if test "$gl_cv_opt_valgrind_tests" != no; then
+        VALGRIND="$VALGRIND $gl_cv_opt_valgrind_tests"
+      else
+        VALGRIND=
+      fi
+    fi
+  fi
+])
diff --git a/m4-gl/visibility.m4 b/m4-gl/visibility.m4
new file mode 100644
index 0000000..8c266a8
--- /dev/null
+++ b/m4-gl/visibility.m4
@@ -0,0 +1,77 @@
+# visibility.m4 serial 6
+dnl Copyright (C) 2005, 2008, 2010-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+
+dnl Tests whether the compiler supports the command-line option
+dnl -fvisibility=hidden and the function and variable attributes
+dnl __attribute__((__visibility__("hidden"))) and
+dnl __attribute__((__visibility__("default"))).
+dnl Does *not* test for __visibility__("protected") - which has tricky
+dnl semantics (see the 'vismain' test in glibc) and does not exist e.g. on
+dnl Mac OS X.
+dnl Does *not* test for __visibility__("internal") - which has processor
+dnl dependent semantics.
+dnl Does *not* test for #pragma GCC visibility push(hidden) - which is
+dnl "really only recommended for legacy code".
+dnl Set the variable CFLAG_VISIBILITY.
+dnl Defines and sets the variable HAVE_VISIBILITY.
+
+AC_DEFUN([gl_VISIBILITY],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  CFLAG_VISIBILITY=
+  HAVE_VISIBILITY=0
+  if test -n "$GCC"; then
+    dnl First, check whether -Werror can be added to the command line, or
+    dnl whether it leads to an error because of some other option that the
+    dnl user has put into $CC $CFLAGS $CPPFLAGS.
+    AC_CACHE_CHECK([whether the -Werror option is usable],
+      [gl_cv_cc_vis_werror],
+      [gl_save_CFLAGS="$CFLAGS"
+       CFLAGS="$CFLAGS -Werror"
+       AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM([[]], [[]])],
+         [gl_cv_cc_vis_werror=yes],
+         [gl_cv_cc_vis_werror=no])
+       CFLAGS="$gl_save_CFLAGS"
+      ])
+    dnl Now check whether visibility declarations are supported.
+    AC_CACHE_CHECK([for simple visibility declarations],
+      [gl_cv_cc_visibility],
+      [gl_save_CFLAGS="$CFLAGS"
+       CFLAGS="$CFLAGS -fvisibility=hidden"
+       dnl We use the option -Werror and a function dummyfunc, because on some
+       dnl platforms (Cygwin 1.7) the use of -fvisibility triggers a warning
+       dnl "visibility attribute not supported in this configuration; ignored"
+       dnl at the first function definition in every compilation unit, and we
+       dnl don't want to use the option in this case.
+       if test $gl_cv_cc_vis_werror = yes; then
+         CFLAGS="$CFLAGS -Werror"
+       fi
+       AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM(
+            [[extern __attribute__((__visibility__("hidden"))) int hiddenvar;
+              extern __attribute__((__visibility__("default"))) int exportedvar;
+              extern __attribute__((__visibility__("hidden"))) int hiddenfunc (void);
+              extern __attribute__((__visibility__("default"))) int exportedfunc (void);
+              void dummyfunc (void) {}
+            ]],
+            [[]])],
+         [gl_cv_cc_visibility=yes],
+         [gl_cv_cc_visibility=no])
+       CFLAGS="$gl_save_CFLAGS"
+      ])
+    if test $gl_cv_cc_visibility = yes; then
+      CFLAG_VISIBILITY="-fvisibility=hidden"
+      HAVE_VISIBILITY=1
+    fi
+  fi
+  AC_SUBST([CFLAG_VISIBILITY])
+  AC_SUBST([HAVE_VISIBILITY])
+  AC_DEFINE_UNQUOTED([HAVE_VISIBILITY], [$HAVE_VISIBILITY],
+    [Define to 1 or 0, depending whether the compiler supports simple visibility declarations.])
+])
diff --git a/m4-gl/warn-on-use.m4 b/m4-gl/warn-on-use.m4
new file mode 100644
index 0000000..7ebe2d3
--- /dev/null
+++ b/m4-gl/warn-on-use.m4
@@ -0,0 +1,51 @@
+# warn-on-use.m4 serial 6
+dnl Copyright (C) 2010-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+# gl_WARN_ON_USE_PREPARE(INCLUDES, NAMES)
+# ---------------------------------------
+# If the module 'posixcheck' is in use:
+#
+# For each whitespace-separated element in the list of NAMES, define
+# HAVE_RAW_DECL_name if the function has a declaration among INCLUDES
+# even after being undefined as a macro.
+#
+# See warn-on-use.h for some hints on how to poison function names, as
+# well as ideas on poisoning global variables and macros.  NAMES may
+# include global variables, but remember that only functions work with
+# _GL_WARN_ON_USE.  Typically, INCLUDES only needs to list a single
+# header, but if the replacement header pulls in other headers because
+# some systems declare functions in the wrong header, then INCLUDES
+# should do likewise.
+#
+# It is generally safe to assume declarations for functions declared
+# in the intersection of C89 and C11 (such as printf) without
+# needing gl_WARN_ON_USE_PREPARE.
+AC_DEFUN([gl_WARN_ON_USE_PREPARE],
+[
+  m4_ifdef([gl_POSIXCHECK],
+    [m4_foreach_w([gl_decl], [$2],
+       [AH_TEMPLATE([HAVE_RAW_DECL_]AS_TR_CPP(m4_defn([gl_decl])),
+         [Define to 1 if ]m4_defn([gl_decl])[ is declared even after
+          undefining macros.])])dnl
+dnl FIXME: gl_Symbol must be used unquoted until we can assume
+dnl autoconf 2.64 or newer.
+     for gl_func in m4_flatten([$2]); do
+       AS_VAR_PUSHDEF([gl_Symbol], [gl_cv_have_raw_decl_$gl_func])dnl
+       AC_CACHE_CHECK([whether $gl_func is declared without a macro],
+         gl_Symbol,
+         [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([$1],
+[@%:@undef $gl_func
+  (void) $gl_func;])],
+           [AS_VAR_SET(gl_Symbol, [yes])], [AS_VAR_SET(gl_Symbol, [no])])])
+       AS_VAR_IF(gl_Symbol, [yes],
+         [AC_DEFINE_UNQUOTED(AS_TR_CPP([HAVE_RAW_DECL_$gl_func]), [1])
+          dnl shortcut - if the raw declaration exists, then set a cache
+          dnl variable to allow skipping any later AC_CHECK_DECL efforts
+          eval ac_cv_have_decl_$gl_func=yes])
+       AS_VAR_POPDEF([gl_Symbol])dnl
+     done
+    ])
+])
diff --git a/m4-gl/wchar_t.m4 b/m4-gl/wchar_t.m4
new file mode 100644
index 0000000..5db5815
--- /dev/null
+++ b/m4-gl/wchar_t.m4
@@ -0,0 +1,24 @@
+# wchar_t.m4 serial 4 (gettext-0.18.2)
+dnl Copyright (C) 2002-2003, 2008-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+dnl Test whether <stddef.h> has the 'wchar_t' type.
+dnl Prerequisite: AC_PROG_CC
+
+AC_DEFUN([gt_TYPE_WCHAR_T],
+[
+  AC_CACHE_CHECK([for wchar_t], [gt_cv_c_wchar_t],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#include <stddef.h>
+            wchar_t foo = (wchar_t)'\0';]],
+          [[]])],
+       [gt_cv_c_wchar_t=yes],
+       [gt_cv_c_wchar_t=no])])
+  if test $gt_cv_c_wchar_t = yes; then
+    AC_DEFINE([HAVE_WCHAR_T], [1], [Define if you have the 'wchar_t' type.])
+  fi
+])
diff --git a/m4-gl/wint_t.m4 b/m4-gl/wint_t.m4
new file mode 100644
index 0000000..61e8a23
--- /dev/null
+++ b/m4-gl/wint_t.m4
@@ -0,0 +1,74 @@
+# wint_t.m4 serial 7
+dnl Copyright (C) 2003, 2007-2019 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+dnl Test whether <wchar.h> has the 'wint_t' type and whether gnulib's
+dnl <wchar.h> or <wctype.h> would, if present, override 'wint_t'.
+dnl Prerequisite: AC_PROG_CC
+
+AC_DEFUN([gt_TYPE_WINT_T],
+[
+  AC_CACHE_CHECK([for wint_t], [gt_cv_c_wint_t],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be included
+   before <wchar.h>.  */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+            wint_t foo = (wchar_t)'\0';]],
+          [[]])],
+       [gt_cv_c_wint_t=yes],
+       [gt_cv_c_wint_t=no])])
+  if test $gt_cv_c_wint_t = yes; then
+    AC_DEFINE([HAVE_WINT_T], [1], [Define if you have the 'wint_t' type.])
+
+    dnl Determine whether gnulib's <wchar.h> or <wctype.h> would, if present,
+    dnl override 'wint_t'.
+    AC_CACHE_CHECK([whether wint_t is too small],
+      [gl_cv_type_wint_t_too_small],
+      [AC_COMPILE_IFELSE(
+           [AC_LANG_PROGRAM([[
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+#if !(defined __GLIBC__ && !defined __UCLIBC__)
+# include <stddef.h>
+# include <stdio.h>
+# include <time.h>
+#endif
+#include <wchar.h>
+              int verify[sizeof (wint_t) < sizeof (int) ? -1 : 1];
+              ]])],
+           [gl_cv_type_wint_t_too_small=no],
+           [gl_cv_type_wint_t_too_small=yes])])
+    if test $gl_cv_type_wint_t_too_small = yes; then
+      GNULIB_OVERRIDES_WINT_T=1
+    else
+      GNULIB_OVERRIDES_WINT_T=0
+    fi
+  else
+    GNULIB_OVERRIDES_WINT_T=0
+  fi
+  AC_SUBST([GNULIB_OVERRIDES_WINT_T])
+])
+
+dnl Prerequisites of the 'wint_t' override.
+AC_DEFUN([gl_TYPE_WINT_T_PREREQ],
+[
+  AC_CHECK_HEADERS_ONCE([crtdefs.h])
+  if test $ac_cv_header_crtdefs_h = yes; then
+    HAVE_CRTDEFS_H=1
+  else
+    HAVE_CRTDEFS_H=0
+  fi
+  AC_SUBST([HAVE_CRTDEFS_H])
+])