Adding upstream version 2.1.6.upstream/2.1.6

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

20 files changed, 1655 insertions, 0 deletions

diff --git a/m4/00gnulib.m4 b/m4/00gnulib.m4
new file mode 100644
index 0000000..14628c3
--- /dev/null
+++ b/m4/00gnulib.m4
@@ -0,0 +1,85 @@
+# 00gnulib.m4 serial 8
+dnl Copyright (C) 2009-2020 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+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 the clang fix has
+dnl been included in Autoconf.
+
+# The following definitions arrange to use a compiler option
+# -Werror=implicit-function-declaration in AC_CHECK_DECL, when the
+# compiler is clang.  Without it, clang implicitly declares "known"
+# library functions in C mode, but not in C++ mode, which would cause
+# Gnulib to omit a declaration and thus later produce an error in C++
+# mode.  As of clang 9.0, these "known" functions are identified through
+# LIBBUILTIN invocations in the LLVM source file
+# llvm/tools/clang/include/clang/Basic/Builtins.def.
+# It's not possible to AC_REQUIRE the extra tests from AC_CHECK_DECL,
+# because AC_CHECK_DECL, like other Autoconf built-ins, is not supposed
+# to AC_REQUIRE anything: some configure.ac files have their first
+# AC_CHECK_DECL executed conditionally.  Therefore append the extra tests
+# to AC_PROG_CC.
+AC_DEFUN([gl_COMPILER_CLANG],
+[
+dnl AC_REQUIRE([AC_PROG_CC])
+  AC_CACHE_CHECK([whether the compiler is clang],
+    [gl_cv_compiler_clang],
+    [dnl Use _AC_COMPILE_IFELSE instead of AC_EGREP_CPP, to avoid error
+     dnl "circular dependency of AC_LANG_COMPILER(C)" if AC_PROG_CC has
+     dnl not yet been invoked.
+     _AC_COMPILE_IFELSE(
+        [AC_LANG_PROGRAM([[
+           #ifdef __clang__
+           barfbarf
+           #endif
+           ]],[[]])
+        ],
+        [gl_cv_compiler_clang=no],
+        [gl_cv_compiler_clang=yes])
+    ])
+])
+AC_DEFUN([gl_COMPILER_PREPARE_CHECK_DECL],
+[
+dnl AC_REQUIRE([AC_PROG_CC])
+dnl AC_REQUIRE([gl_COMPILER_CLANG])
+  AC_CACHE_CHECK([for compiler option needed when checking for declarations],
+    [gl_cv_compiler_check_decl_option],
+    [if test $gl_cv_compiler_clang = yes; then
+       dnl Test whether the compiler supports the option
+       dnl '-Werror=implicit-function-declaration'.
+       save_ac_compile="$ac_compile"
+       ac_compile="$ac_compile -Werror=implicit-function-declaration"
+       dnl Use _AC_COMPILE_IFELSE instead of AC_COMPILE_IFELSE, to avoid a
+       dnl warning "AC_COMPILE_IFELSE was called before AC_USE_SYSTEM_EXTENSIONS".
+       _AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[]],[[]])],
+         [gl_cv_compiler_check_decl_option='-Werror=implicit-function-declaration'],
+         [gl_cv_compiler_check_decl_option=none])
+       ac_compile="$save_ac_compile"
+     else
+       gl_cv_compiler_check_decl_option=none
+     fi
+    ])
+  if test "x$gl_cv_compiler_check_decl_option" != xnone; then
+    ac_compile_for_check_decl="$ac_compile $gl_cv_compiler_check_decl_option"
+  else
+    ac_compile_for_check_decl="$ac_compile"
+  fi
+])
+dnl Redefine _AC_CHECK_DECL_BODY so that it references ac_compile_for_check_decl
+dnl instead of ac_compile.  If, for whatever reason, the override of AC_PROG_CC
+dnl in zzgnulib.m4 is inactive, use the original ac_compile.
+m4_define([_AC_CHECK_DECL_BODY],
+[  ac_save_ac_compile="$ac_compile"
+  if test -n "$ac_compile_for_check_decl"; then
+    ac_compile="$ac_compile_for_check_decl"
+  fi]
+m4_defn([_AC_CHECK_DECL_BODY])[  ac_compile="$ac_save_ac_compile"
+])
+
+# 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/CC_CHECK_LDFLAGS.m4 b/m4/CC_CHECK_LDFLAGS.m4
new file mode 100644
index 0000000..be20df3
--- /dev/null
+++ b/m4/CC_CHECK_LDFLAGS.m4
@@ -0,0 +1,21 @@
+dnl Check if the flag is supported by linker (cacheable)
+dnl CC_CHECK_LDFLAGS([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND])
+dnl
+dnl Origin (declared license: GPLv2+ with less restrictive exception):
+dnl https://git.gnome.org/browse/glib/tree/m4macros/attributes.m4?h=2.49.1
+dnl (AC_LANG_PROGRAM substituted by Jan Pokorny <jpokorny@redhat.com>)
+
+AC_DEFUN([CC_CHECK_LDFLAGS], [
+  AC_CACHE_CHECK([if $CC supports $1 flag],
+    AS_TR_SH([cc_cv_ldflags_$1]),
+    [ac_save_LDFLAGS="$LDFLAGS"
+     LDFLAGS="$LDFLAGS $1"
+     AC_LINK_IFELSE([AC_LANG_PROGRAM([[]], [[]])],
+       [eval "AS_TR_SH([cc_cv_ldflags_$1])='yes'"],
+       [eval "AS_TR_SH([cc_cv_ldflags_$1])="])
+     LDFLAGS="$ac_save_LDFLAGS"
+    ])
+
+  AS_IF([eval test x$]AS_TR_SH([cc_cv_ldflags_$1])[ = xyes],
+    [$2], [$3])
+])
diff --git a/m4/CHECK_ENUM_VALUE.m4 b/m4/CHECK_ENUM_VALUE.m4
new file mode 100644
index 0000000..50bbe23
--- /dev/null
+++ b/m4/CHECK_ENUM_VALUE.m4
@@ -0,0 +1,21 @@
+# CHECK_ENUM_VALUE([HEADER], [ENUM_NAME], [ENUM_VALUE])
+#
+# Define HAVE_[ENUM_NAME]_[ENUM_VALUE] if the specified enum value is
+# available.
+dnl
+dnl Copyright 2018-2020 the Pacemaker project contributors
+dnl
+dnl The version control history for this file may have further details.
+dnl
+dnl This source code is licensed under the GNU General Public License version 2
+dnl or later (GPLv2+) WITHOUT ANY WARRANTY.
+
+AC_DEFUN([CHECK_ENUM_VALUE], [
+    AC_MSG_CHECKING(whether $1 defines enum $2 value $3)
+    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <$1>],
+                                       [enum $2 check_$2_$3 = $3])],
+                      [AC_DEFINE_UNQUOTED(HAVE_$2_$3, 1,
+                                          [Whether enum $2 supports $3])
+                       AC_MSG_RESULT(yes)],
+                      [AC_MSG_RESULT(no)])
+])
diff --git a/m4/CONFIG_FILES_EXEC.m4 b/m4/CONFIG_FILES_EXEC.m4
new file mode 100644
index 0000000..290ba21
--- /dev/null
+++ b/m4/CONFIG_FILES_EXEC.m4
@@ -0,0 +1,24 @@
+#
+# Copyright 2021 the Pacemaker project contributors
+#
+# The version control history for this file may have further details.
+#
+# This source code is licensed under the GNU General Public License version 2
+# or later (GPLv2+) WITHOUT ANY WARRANTY.
+
+# CONFIG_FILE_EXEC(FILE [...])
+#
+# Mark single FILE as configure-generated, and make it executable once created.
+#
+AC_DEFUN([CONFIG_FILE_EXEC], [AC_CONFIG_FILES([$1], [chmod +x "$1"])])
+
+# CONFIG_FILES_EXEC(FILE [...])
+#
+# Mark multiple FILEs as configure-generated, and make them executable.
+#
+AC_DEFUN([CONFIG_FILES_EXEC], [
+    m4_case([$#], [0], [],
+                  [1], [CONFIG_FILE_EXEC([$1])],
+                  [CONFIG_FILE_EXEC([$1])
+                   CONFIG_FILES_EXEC(m4_shift($@))])
+])
diff --git a/m4/PKG_CHECK_VAR.m4 b/m4/PKG_CHECK_VAR.m4
new file mode 100644
index 0000000..2221a69
--- /dev/null
+++ b/m4/PKG_CHECK_VAR.m4
@@ -0,0 +1,24 @@
+dnl PKG_CHECK_VAR(VARIABLE, MODULE, CONFIG-VARIABLE,
+dnl [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+dnl -------------------------------------------
+dnl Since: 0.28
+dnl
+dnl Retrieves the value of the pkg-config variable for the given module.
+dnl
+dnl Origin (declared license: GPLv2+ with less restrictive exception):
+dnl https://cgit.freedesktop.org/pkg-config/tree/pkg.m4.in?h=pkg-config-0.29.1#n261
+dnl (AS_VAR_COPY replaced with backward-compatible equivalent and guard
+dnl to prefer system-wide variant by Jan Pokorny <jpokorny@redhat.com>)
+
+m4_ifndef([PKG_CHECK_VAR],[
+AC_DEFUN([PKG_CHECK_VAR],
+[AC_REQUIRE([PKG_PROG_PKG_CONFIG])dnl
+AC_ARG_VAR([$1], [value of $3 for $2, overriding pkg-config])dnl
+
+_PKG_CONFIG([$1], [variable="][$3]["], [$2])
+dnl AS_VAR_COPY([$1], [pkg_cv_][$1])
+$1=AS_VAR_GET([pkg_cv_][$1])
+
+AS_VAR_IF([$1], [""], [$5], [$4])dnl
+])dnl PKG_CHECK_VAR
+])dnl m4_ifndef
diff --git a/m4/REQUIRE_FUNC.m4 b/m4/REQUIRE_FUNC.m4
new file mode 100644
index 0000000..2b6986a
--- /dev/null
+++ b/m4/REQUIRE_FUNC.m4
@@ -0,0 +1,16 @@
+# REQUIRE_FUNC([FUNC])
+#
+# Error if a standard C library function can't be found
+#
+dnl
+dnl Copyright 2021 the Pacemaker project contributors
+dnl
+dnl The version control history for this file may have further details.
+dnl
+dnl This source code is licensed under the GNU General Public License version 2
+dnl or later (GPLv2+) WITHOUT ANY WARRANTY.
+
+dnl Usage: REQUIRE_FUNC(function-name)
+AC_DEFUN([REQUIRE_FUNC], [
+    AC_CHECK_FUNC([$1], [], [AC_MSG_ERROR(Could not find required C function $1)])
+])
diff --git a/m4/REQUIRE_HEADER.m4 b/m4/REQUIRE_HEADER.m4
new file mode 100644
index 0000000..d723458
--- /dev/null
+++ b/m4/REQUIRE_HEADER.m4
@@ -0,0 +1,16 @@
+# REQUIRE_HEADER([HEADER])
+#
+# Error if a C header file can't be found
+#
+dnl
+dnl Copyright 2020 the Pacemaker project contributors
+dnl
+dnl The version control history for this file may have further details.
+dnl
+dnl This source code is licensed under the GNU General Public License version 2
+dnl or later (GPLv2+) WITHOUT ANY WARRANTY.
+
+dnl Usage: REQUIRE_HEADER(header-file, [prerequisite-includes])
+AC_DEFUN([REQUIRE_HEADER], [
+    AC_CHECK_HEADERS([$1], [], [AC_MSG_ERROR(Could not find required C header $1)], [$2])
+])
diff --git a/m4/REQUIRE_LIB.m4 b/m4/REQUIRE_LIB.m4
new file mode 100644
index 0000000..1c874eb
--- /dev/null
+++ b/m4/REQUIRE_LIB.m4
@@ -0,0 +1,15 @@
+#
+# Copyright 2021 the Pacemaker project contributors
+#
+# The version control history for this file may have further details.
+#
+# This source code is licensed under the GNU General Public License version 2
+# or later (GPLv2+) WITHOUT ANY WARRANTY.
+
+# REQUIRE_LIB(LIBRARY, FUNCTION)
+#
+# Error if a C library can't be found or doesn't contain a specified function
+#
+AC_DEFUN([REQUIRE_LIB], [
+    AC_CHECK_LIB([$1],[$2],,[AC_MSG_FAILURE([Unable to find required C library lib$1])])
+])
diff --git a/m4/ax_check_link_flag.m4 b/m4/ax_check_link_flag.m4
new file mode 100644
index 0000000..819409a
--- /dev/null
+++ b/m4/ax_check_link_flag.m4
@@ -0,0 +1,74 @@
+# ===========================================================================
+#    https://www.gnu.org/software/autoconf-archive/ax_check_link_flag.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_CHECK_LINK_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
+#
+# DESCRIPTION
+#
+#   Check whether the given FLAG works with the linker or gives an error.
+#   (Warnings, however, are ignored)
+#
+#   ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
+#   success/failure.
+#
+#   If EXTRA-FLAGS is defined, it is added to the linker's default flags
+#   when the check is done.  The check is thus made with the flags: "LDFLAGS
+#   EXTRA-FLAGS FLAG".  This can for example be used to force the linker to
+#   issue an error when a bad flag is given.
+#
+#   INPUT gives an alternative input source to AC_LINK_IFELSE.
+#
+#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
+#   macro in sync with AX_CHECK_{PREPROC,COMPILE}_FLAG.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+#   This program is free software: you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <https://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 5
+
+AC_DEFUN([AX_CHECK_LINK_FLAG],
+[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
+AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_ldflags_$4_$1])dnl
+AC_CACHE_CHECK([whether the linker accepts $1], CACHEVAR, [
+  ax_check_save_flags=$LDFLAGS
+  LDFLAGS="$LDFLAGS $4 $1"
+  AC_LINK_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
+    [AS_VAR_SET(CACHEVAR,[yes])],
+    [AS_VAR_SET(CACHEVAR,[no])])
+  LDFLAGS=$ax_check_save_flags])
+AS_VAR_IF(CACHEVAR,yes,
+  [m4_default([$2], :)],
+  [m4_default([$3], :)])
+AS_VAR_POPDEF([CACHEVAR])dnl
+])dnl AX_CHECK_LINK_FLAGS
diff --git a/m4/byteswap.m4 b/m4/byteswap.m4
new file mode 100644
index 0000000..0f43994
--- /dev/null
+++ b/m4/byteswap.m4
@@ -0,0 +1,19 @@
+# byteswap.m4 serial 4
+dnl Copyright (C) 2005, 2007, 2009-2020 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl Written by Oskar Liljeblad.
+
+AC_DEFUN([gl_BYTESWAP],
+[
+  dnl Prerequisites of lib/byteswap.in.h.
+  AC_CHECK_HEADERS([byteswap.h], [
+    BYTESWAP_H=''
+  ], [
+    BYTESWAP_H='byteswap.h'
+  ])
+  AC_SUBST([BYTESWAP_H])
+  AM_CONDITIONAL([GL_GENERATE_BYTESWAP_H], [test -n "$BYTESWAP_H"])
+])
diff --git a/m4/extern-inline.m4 b/m4/extern-inline.m4
new file mode 100644
index 0000000..75c5008
--- /dev/null
+++ b/m4/extern-inline.m4
@@ -0,0 +1,114 @@
+dnl 'extern inline' a la ISO C99.
+
+dnl Copyright 2012-2020 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+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/clang-master-potential/20141111_102002/logs/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-openssl.m4 b/m4/gl-openssl.m4
new file mode 100644
index 0000000..e950904
--- /dev/null
+++ b/m4/gl-openssl.m4
@@ -0,0 +1,66 @@
+# gl-openssl.m4 serial 5
+dnl Copyright (C) 2013-2020 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_SET_CRYPTO_CHECK_DEFAULT],
+[
+  m4_define([gl_CRYPTO_CHECK_DEFAULT], [$1])
+])
+gl_SET_CRYPTO_CHECK_DEFAULT([no])
+
+AC_DEFUN([gl_CRYPTO_CHECK],
+[
+  dnl gnulib users set this before gl_INIT with gl_SET_CRYPTO_CHECK_DEFAULT()
+  m4_divert_once([DEFAULTS], [with_openssl_default='gl_CRYPTO_CHECK_DEFAULT'])
+
+  dnl Only clear once, so crypto routines can be checked for individually
+  m4_divert_once([DEFAULTS], [LIB_CRYPTO=])
+
+  AC_ARG_WITH([openssl],
+    [AS_HELP_STRING([--with-openssl],
+      [use libcrypto hash routines. Valid ARGs are:
+       'yes', 'no',
+       'auto' => use if any version available,
+       'auto-gpl-compat' => use if gpl compatible version available,
+       'optional' => use if available and warn if not available;
+       default is ']gl_CRYPTO_CHECK_DEFAULT['.
+       Note also --with-linux-crypto, which will enable
+       use of kernel crypto routines, which have precedence])],
+    [],
+    [with_openssl=$with_openssl_default])
+
+  AC_SUBST([LIB_CRYPTO])
+  if test "x$with_openssl" != xno; then
+    if test "x$with_openssl" = xauto-gpl-compat; then
+      AC_CACHE_CHECK([whether openssl is GPL compatible],
+                     [gl_cv_openssl_gpl_compat],
+        [AC_COMPILE_IFELSE(
+           [AC_LANG_PROGRAM([[
+                #include <openssl/opensslv.h>
+                #if OPENSSL_VERSION_MAJOR < 3
+                  #error "openssl >= version 3 not found"
+                #endif
+              ]])],
+           [gl_cv_openssl_gpl_compat=yes],
+           [gl_cv_openssl_gpl_compat=no])])
+    fi
+    if test "x$with_openssl" != xauto-gpl-compat ||
+       test "x$gl_cv_openssl_gpl_compat" = xyes; then
+      AC_CHECK_LIB([crypto], [$1],
+        [AC_CHECK_HEADERS(
+           m4_if([$1], [MD5], [openssl/md5.h], [openssl/sha.h]),
+           [LIB_CRYPTO=-lcrypto
+            AC_DEFINE([HAVE_OPENSSL_$1], [1],
+              [Define to 1 if libcrypto is used for $1.])])])
+    fi
+    if test "x$LIB_CRYPTO" = x; then
+      if test "x$with_openssl" = xyes; then
+        AC_MSG_ERROR([openssl development library not found for $1])
+      elif test "x$with_openssl" = xoptional; then
+        AC_MSG_WARN([openssl development library not found for $1])
+      fi
+    fi
+  fi
+])
diff --git a/m4/gnulib-cache.m4 b/m4/gnulib-cache.m4
new file mode 100644
index 0000000..56cc36b
--- /dev/null
+++ b/m4/gnulib-cache.m4
@@ -0,0 +1,63 @@
+# Copyright (C) 2002-2020 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 specification of how gnulib-tool is used.
+# It acts as a cache: It is written and read by gnulib-tool.
+# In projects that use version control, this file is meant to be put under
+# version control, like the configure.ac and various Makefile.am files.
+
+
+# Specification in the form of a command-line invocation:
+# gnulib-tool --import \
+#  --lib=libgnu \
+#  --source-base=lib/gnu \
+#  --m4-base=m4 \
+#  --doc-base=doc \
+#  --tests-base=tests \
+#  --aux-dir=. \
+#  --lgpl=2 \
+#  --no-conditional-dependencies \
+#  --libtool \
+#  --macro-prefix=gl \
+#  --no-vc-files \
+#  --avoid=stdint \
+#  crypto/md5-buffer
+
+# Specification in the form of a few gnulib-tool.m4 macro invocations:
+gl_LOCAL_DIR([])
+gl_MODULES([
+  crypto/md5-buffer
+])
+gl_AVOID([ stdint])
+gl_SOURCE_BASE([lib/gnu])
+gl_M4_BASE([m4])
+gl_PO_BASE([])
+gl_DOC_BASE([doc])
+gl_TESTS_BASE([tests])
+gl_LIB([libgnu])
+gl_LGPL([2])
+gl_MAKEFILE_NAME([])
+gl_LIBTOOL
+gl_MACRO_PREFIX([gl])
+gl_PO_DOMAIN([])
+gl_WITNESS_C_MACRO([])
+gl_VC_FILES([false])
diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4
new file mode 100644
index 0000000..8a40713
--- /dev/null
+++ b/m4/gnulib-common.m4
@@ -0,0 +1,723 @@
+# gnulib-common.m4 serial 62
+dnl Copyright (C) 2007-2020 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+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_REQUIRE([gl_ZZGNULIB])
+])
+AC_DEFUN([gl_COMMON_BODY], [
+  AH_VERBATIM([_GL_GNUC_PREREQ],
+[/* True if the compiler says it groks GNU C version MAJOR.MINOR.  */
+#if defined __GNUC__ && defined __GNUC_MINOR__
+# define _GL_GNUC_PREREQ(major, minor) \
+    ((major) < __GNUC__ + ((minor) <= __GNUC_MINOR__))
+#else
+# define _GL_GNUC_PREREQ(major, minor) 0
+#endif
+])
+  AH_VERBATIM([_Noreturn],
+[/* The _Noreturn keyword of C11.  */
+#ifndef _Noreturn
+# if (defined __cplusplus \
+      && ((201103 <= __cplusplus && !(__GNUC__ == 4 && __GNUC_MINOR__ == 7)) \
+          || (defined _MSC_VER && 1900 <= _MSC_VER)) \
+      && 0)
+    /* [[noreturn]] is not practically usable, because with it the syntax
+         extern _Noreturn void func (...);
+       would not be valid; such a declaration would only be valid with 'extern'
+       and '_Noreturn' swapped, or without the 'extern' keyword.  However, some
+       AIX system header files and several gnulib header files use precisely
+       this syntax with 'extern'.  */
+#  define _Noreturn [[noreturn]]
+# elif ((!defined __cplusplus || defined __clang__) \
+        && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0)  \
+            || _GL_GNUC_PREREQ (4, 7) \
+            || (defined __apple_build_version__ \
+                ? 6000000 <= __apple_build_version__ \
+                : 3 < __clang_major__ + (5 <= __clang_minor__))))
+   /* _Noreturn works as-is.  */
+# elif _GL_GNUC_PREREQ (2, 8) || defined __clang__ || 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([attribute],
+[/* Attributes.  */
+#ifdef __has_attribute
+# define _GL_HAS_ATTRIBUTE(attr) __has_attribute (__##attr##__)
+#else
+# define _GL_HAS_ATTRIBUTE(attr) _GL_ATTR_##attr
+# define _GL_ATTR_alloc_size _GL_GNUC_PREREQ (4, 3)
+# define _GL_ATTR_always_inline _GL_GNUC_PREREQ (3, 2)
+# define _GL_ATTR_artificial _GL_GNUC_PREREQ (4, 3)
+# define _GL_ATTR_cold _GL_GNUC_PREREQ (4, 3)
+# define _GL_ATTR_const _GL_GNUC_PREREQ (2, 95)
+# define _GL_ATTR_deprecated _GL_GNUC_PREREQ (3, 1)
+# define _GL_ATTR_diagnose_if 0
+# define _GL_ATTR_error _GL_GNUC_PREREQ (4, 3)
+# define _GL_ATTR_externally_visible _GL_GNUC_PREREQ (4, 1)
+# define _GL_ATTR_fallthrough _GL_GNUC_PREREQ (7, 0)
+# define _GL_ATTR_format _GL_GNUC_PREREQ (2, 7)
+# define _GL_ATTR_leaf _GL_GNUC_PREREQ (4, 6)
+# ifdef _ICC
+#  define _GL_ATTR_may_alias 0
+# else
+#  define _GL_ATTR_may_alias _GL_GNUC_PREREQ (3, 3)
+# endif
+# define _GL_ATTR_malloc _GL_GNUC_PREREQ (3, 0)
+# define _GL_ATTR_noinline _GL_GNUC_PREREQ (3, 1)
+# define _GL_ATTR_nonnull _GL_GNUC_PREREQ (3, 3)
+# define _GL_ATTR_nonstring _GL_GNUC_PREREQ (8, 0)
+# define _GL_ATTR_nothrow _GL_GNUC_PREREQ (3, 3)
+# define _GL_ATTR_packed _GL_GNUC_PREREQ (2, 7)
+# define _GL_ATTR_pure _GL_GNUC_PREREQ (2, 96)
+# define _GL_ATTR_returns_nonnull _GL_GNUC_PREREQ (4, 9)
+# define _GL_ATTR_sentinel _GL_GNUC_PREREQ (4, 0)
+# define _GL_ATTR_unused _GL_GNUC_PREREQ (2, 7)
+# define _GL_ATTR_warn_unused_result _GL_GNUC_PREREQ (3, 4)
+#endif
+
+]dnl There is no _GL_ATTRIBUTE_ALIGNED; use stdalign's _Alignas instead.
+[
+#if _GL_HAS_ATTRIBUTE (alloc_size)
+# define _GL_ATTRIBUTE_ALLOC_SIZE(args) __attribute__ ((__alloc_size__ args))
+#else
+# define _GL_ATTRIBUTE_ALLOC_SIZE(args)
+#endif
+
+#if _GL_HAS_ATTRIBUTE (always_inline)
+# define _GL_ATTRIBUTE_ALWAYS_INLINE __attribute__ ((__always_inline__))
+#else
+# define _GL_ATTRIBUTE_ALWAYS_INLINE
+#endif
+
+#if _GL_HAS_ATTRIBUTE (artificial)
+# define _GL_ATTRIBUTE_ARTIFICIAL __attribute__ ((__artificial__))
+#else
+# define _GL_ATTRIBUTE_ARTIFICIAL
+#endif
+
+/* Avoid __attribute__ ((cold)) on MinGW; see thread starting at
+   <https://lists.gnu.org/r/emacs-devel/2019-04/msg01152.html>.
+   Also, Oracle Studio 12.6 requires 'cold' not '__cold__'.  */
+#if _GL_HAS_ATTRIBUTE (cold) && !defined __MINGW32__
+# ifndef __SUNPRO_C
+#  define _GL_ATTRIBUTE_COLD __attribute__ ((__cold__))
+# else
+#  define _GL_ATTRIBUTE_COLD __attribute__ ((cold))
+# endif
+#else
+# define _GL_ATTRIBUTE_COLD
+#endif
+
+#if _GL_HAS_ATTRIBUTE (const)
+# define _GL_ATTRIBUTE_CONST __attribute__ ((__const__))
+#else
+# define _GL_ATTRIBUTE_CONST
+#endif
+
+#if 201710L < __STDC_VERSION__
+# define _GL_ATTRIBUTE_DEPRECATED [[__deprecated__]]
+#elif _GL_HAS_ATTRIBUTE (deprecated)
+# define _GL_ATTRIBUTE_DEPRECATED __attribute__ ((__deprecated__))
+#else
+# define _GL_ATTRIBUTE_DEPRECATED
+#endif
+
+#if _GL_HAS_ATTRIBUTE (error)
+# define _GL_ATTRIBUTE_ERROR(msg) __attribute__ ((__error__ (msg)))
+# define _GL_ATTRIBUTE_WARNING(msg) __attribute__ ((__warning__ (msg)))
+#elif _GL_HAS_ATTRIBUTE (diagnose_if)
+# define _GL_ATTRIBUTE_ERROR(msg) __attribute__ ((__diagnose_if__ (1, msg, "error")))
+# define _GL_ATTRIBUTE_WARNING(msg) __attribute__ ((__diagnose_if__ (1, msg, "warning")))
+#else
+# define _GL_ATTRIBUTE_ERROR(msg)
+# define _GL_ATTRIBUTE_WARNING(msg)
+#endif
+
+#if _GL_HAS_ATTRIBUTE (externally_visible)
+# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE __attribute__ ((externally_visible))
+#else
+# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE
+#endif
+
+/* FALLTHROUGH is special, because it always expands to something.  */
+#if 201710L < __STDC_VERSION__
+# define _GL_ATTRIBUTE_FALLTHROUGH [[__fallthrough__]]
+#elif _GL_HAS_ATTRIBUTE (fallthrough)
+# define _GL_ATTRIBUTE_FALLTHROUGH __attribute__ ((__fallthrough__))
+#else
+# define _GL_ATTRIBUTE_FALLTHROUGH ((void) 0)
+#endif
+
+#if _GL_HAS_ATTRIBUTE (format)
+# define _GL_ATTRIBUTE_FORMAT(spec) __attribute__ ((__format__ spec))
+#else
+# define _GL_ATTRIBUTE_FORMAT(spec)
+#endif
+
+#if _GL_HAS_ATTRIBUTE (leaf)
+# define _GL_ATTRIBUTE_LEAF __attribute__ ((__leaf__))
+#else
+# define _GL_ATTRIBUTE_LEAF
+#endif
+
+/* Oracle Studio 12.6 mishandles may_alias despite __has_attribute OK.  */
+#if _GL_HAS_ATTRIBUTE (may_alias) && !defined __SUNPRO_C
+# define _GL_ATTRIBUTE_MAY_ALIAS __attribute__ ((__may_alias__))
+#else
+# define _GL_ATTRIBUTE_MAY_ALIAS
+#endif
+
+#if 201710L < __STDC_VERSION__
+# define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]]
+#elif _GL_HAS_ATTRIBUTE (unused)
+# define _GL_ATTRIBUTE_MAYBE_UNUSED __attribute__ ((__unused__))
+#else
+# define _GL_ATTRIBUTE_MAYBE_UNUSED
+#endif
+/* Earlier spellings of this macro.  */
+#define _GL_UNUSED _GL_ATTRIBUTE_MAYBE_UNUSED
+#define _UNUSED_PARAMETER_ _GL_ATTRIBUTE_MAYBE_UNUSED
+
+#if _GL_HAS_ATTRIBUTE (malloc)
+# define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
+#else
+# define _GL_ATTRIBUTE_MALLOC
+#endif
+
+#if 201710L < __STDC_VERSION__
+# define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]]
+#elif _GL_HAS_ATTRIBUTE (warn_unused_result)
+# define _GL_ATTRIBUTE_NODISCARD __attribute__ ((__warn_unused_result__))
+#else
+# define _GL_ATTRIBUTE_NODISCARD
+#endif
+
+#if _GL_HAS_ATTRIBUTE (noinline)
+# define _GL_ATTRIBUTE_NOINLINE __attribute__ ((__noinline__))
+#else
+# define _GL_ATTRIBUTE_NOINLINE
+#endif
+
+#if _GL_HAS_ATTRIBUTE (nonnull)
+# define _GL_ATTRIBUTE_NONNULL(args) __attribute__ ((__nonnull__ args))
+#else
+# define _GL_ATTRIBUTE_NONNULL(args)
+#endif
+
+#if _GL_HAS_ATTRIBUTE (nonstring)
+# define _GL_ATTRIBUTE_NONSTRING __attribute__ ((__nonstring__))
+#else
+# define _GL_ATTRIBUTE_NONSTRING
+#endif
+
+/* There is no _GL_ATTRIBUTE_NORETURN; use _Noreturn instead.  */
+
+#if _GL_HAS_ATTRIBUTE (nothrow) && !defined __cplusplus
+# define _GL_ATTRIBUTE_NOTHROW __attribute__ ((__nothrow__))
+#else
+# define _GL_ATTRIBUTE_NOTHROW
+#endif
+
+#if _GL_HAS_ATTRIBUTE (packed)
+# define _GL_ATTRIBUTE_PACKED __attribute__ ((__packed__))
+#else
+# define _GL_ATTRIBUTE_PACKED
+#endif
+
+#if _GL_HAS_ATTRIBUTE (pure)
+# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
+#else
+# define _GL_ATTRIBUTE_PURE
+#endif
+
+#if _GL_HAS_ATTRIBUTE (returns_nonnull)
+# define _GL_ATTRIBUTE_RETURNS_NONNULL __attribute__ ((__returns_nonnull__))
+#else
+# define _GL_ATTRIBUTE_RETURNS_NONNULL
+#endif
+
+#if _GL_HAS_ATTRIBUTE (sentinel)
+# define _GL_ATTRIBUTE_SENTINEL(pos) __attribute__ ((__sentinel__ pos))
+#else
+# define _GL_ATTRIBUTE_SENTINEL(pos)
+#endif
+
+]dnl There is no _GL_ATTRIBUTE_VISIBILITY; see m4/visibility.m4 instead.
+[
+/* To support C++ as well as C, use _GL_UNUSED_LABEL with trailing ';'.  */
+#if !defined __cplusplus || _GL_GNUC_PREREQ (4, 5)
+# define _GL_UNUSED_LABEL _GL_ATTRIBUTE_MAYBE_UNUSED
+#else
+# define _GL_UNUSED_LABEL
+#endif
+])
+  AH_VERBATIM([async_safe],
+[/* 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
+       <https://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
+])
+  AH_VERBATIM([micro_optimizations],
+[/* _GL_CMP (n1, n2) performs a three-valued comparison on n1 vs. n2, where
+   n1 and n2 are expressions without side effects, that evaluate to real
+   numbers (excluding NaN).
+   It returns
+     1  if n1 > n2
+     0  if n1 == n2
+     -1 if n1 < n2
+   The naïve code   (n1 > n2 ? 1 : n1 < n2 ? -1 : 0)  produces a conditional
+   jump with nearly all GCC versions up to GCC 10.
+   This variant     (n1 < n2 ? -1 : n1 > n2)  produces a conditional with many
+   GCC versions up to GCC 9.
+   The better code  (n1 > n2) - (n1 < n2)  from Hacker's Delight § 2-9
+   avoids conditional jumps in all GCC versions >= 3.4.  */
+#define _GL_CMP(n1, n2) (((n1) > (n2)) - ((n1) < (n2)))
+])
+  dnl Hint which direction to take regarding cross-compilation guesses:
+  dnl When a user installs a program on a platform they are not intimately
+  dnl familiar with, --enable-cross-guesses=conservative is the appropriate
+  dnl choice.  It implements the "If we don't know, assume the worst" principle.
+  dnl However, when an operating system developer (on a platform which is not
+  dnl yet known to gnulib) builds packages for their platform, they want to
+  dnl expose, not hide, possible platform bugs; in this case,
+  dnl --enable-cross-guesses=risky is the appropriate choice.
+  dnl Sets the variables
+  dnl gl_cross_guess_normal    (to be used when 'yes' is good and 'no' is bad),
+  dnl gl_cross_guess_inverted  (to be used when 'no' is good and 'yes' is bad).
+  AC_ARG_ENABLE([cross-guesses],
+    [AS_HELP_STRING([--enable-cross-guesses={conservative|risky}],
+       [specify policy for cross-compilation guesses])],
+    [if test "x$enableval" != xconservative && test "x$enableval" != xrisky; then
+       AC_MSG_WARN([invalid argument supplied to --enable-cross-guesses])
+       enableval=conservative
+     fi
+     gl_cross_guesses="$enableval"],
+    [gl_cross_guesses=conservative])
+  if test $gl_cross_guesses = risky; then
+    gl_cross_guess_normal="guessing yes"
+    gl_cross_guess_inverted="guessing no"
+  else
+    gl_cross_guess_normal="guessing no"
+    gl_cross_guess_inverted="guessing yes"
+  fi
+  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])
+])
+
+# gl_PROG_CC_C99
+# Modifies the value of the shell variable CC in an attempt to make $CC
+# understand ISO C99 source code.
+AC_DEFUN([gl_PROG_CC_C99],
+[
+  dnl Just use AC_PROG_CC_C99.
+  dnl When AC_PROG_CC_C99 and AC_PROG_CC_STDC are used together, the substituted
+  dnl value of CC will contain the C99 enabling options twice. But this is only
+  dnl a cosmetic problem.
+  dnl With Autoconf >= 2.69c, use AC_PROG_CC since it implies AC_PROG_CC_C99;
+  dnl this avoids a "warning: The macro `AC_PROG_CC_C99' is obsolete."
+  m4_version_prereq([2.69c],
+    [AC_REQUIRE([AC_PROG_CC])],
+    [AC_REQUIRE([AC_PROG_CC_C99])])
+])
+
+# 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 older versions of Sun C++, which did not
+   #define __restrict__ or support _Restrict or __restrict__
+   even though the corresponding Sun C compiler ended up with
+   "#define restrict _Restrict" or "#define restrict __restrict__"
+   in the previous line.  This workaround can be removed once
+   we assume Oracle Developer Studio 12.5 (2016) or later.  */
+#if defined __SUNPRO_CC && !defined __RESTRICT && !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
+])
+
+# A temporary file descriptor.
+# Must be less than 10, because dash 0.5.8 does not support redirections
+# with multi-digit file descriptors.
+m4_define([GL_TMP_FD], 9)
+
+# gl_SILENT(command)
+# executes command, but without the normal configure output.
+# This is useful when you want to invoke AC_CACHE_CHECK (or AC_CHECK_FUNC etc.)
+# inside another AC_CACHE_CHECK.
+AC_DEFUN([gl_SILENT],
+[
+  exec GL_TMP_FD>&AS_MESSAGE_FD AS_MESSAGE_FD>/dev/null
+  $1
+  exec AS_MESSAGE_FD>&GL_TMP_FD GL_TMP_FD>&-
+])
+
+# 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],
+[
+  gl_SILENT([
+    AC_CACHE_VAL([$1], [$2])
+  ])
+])
+
+dnl Expands to some code for use in .c programs that, on native Windows, defines
+dnl the Microsoft deprecated alias function names to the underscore-prefixed
+dnl actual function names. With this macro, these function names are available
+dnl without linking with '-loldnames' and without generating warnings.
+dnl Usage: Use it after all system header files are included.
+dnl          #include <...>
+dnl          #include <...>
+dnl          ]GL_MDA_DEFINES[
+dnl          ...
+AC_DEFUN([GL_MDA_DEFINES],[
+AC_REQUIRE([_GL_MDA_DEFINES])
+[$gl_mda_defines]
+])
+AC_DEFUN([_GL_MDA_DEFINES],
+[gl_mda_defines='
+#if defined _WIN32 && !defined __CYGWIN__
+#define access    _access
+#define chdir     _chdir
+#define chmod     _chmod
+#define close     _close
+#define creat     _creat
+#define dup       _dup
+#define dup2      _dup2
+#define ecvt      _ecvt
+#define execl     _execl
+#define execle    _execle
+#define execlp    _execlp
+#define execv     _execv
+#define execve    _execve
+#define execvp    _execvp
+#define execvpe   _execvpe
+#define fcloseall _fcloseall
+#define fcvt      _fcvt
+#define fdopen    _fdopen
+#define fileno    _fileno
+#define gcvt      _gcvt
+#define getcwd    _getcwd
+#define getpid    _getpid
+#define getw      _getw
+#define isatty    _isatty
+#define j0        _j0
+#define j1        _j1
+#define jn        _jn
+#define lfind     _lfind
+#define lsearch   _lsearch
+#define lseek     _lseek
+#define memccpy   _memccpy
+#define mkdir     _mkdir
+#define mktemp    _mktemp
+#define open      _open
+#define putenv    _putenv
+#define putw      _putw
+#define read      _read
+#define rmdir     _rmdir
+#define strdup    _strdup
+#define swab      _swab
+#define tempnam   _tempnam
+#define tzset     _tzset
+#define umask     _umask
+#define unlink    _unlink
+#define utime     _utime
+#define wcsdup    _wcsdup
+#define write     _write
+#define y0        _y0
+#define y1        _y1
+#define yn        _yn
+#endif
+'
+])
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
new file mode 100644
index 0000000..4d1ae74
--- /dev/null
+++ b/m4/gnulib-comp.m4
@@ -0,0 +1,221 @@
+# DO NOT EDIT! GENERATED AUTOMATICALLY!
+# Copyright (C) 2002-2020 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$])dnl a variable
+
+  # Pre-early section.
+  AC_REQUIRE([gl_PROG_AR_RANLIB])
+
+  # Code from module byteswap:
+  # Code from module c99:
+  # Code from module crypto/md5-buffer:
+  # Code from module extern-inline:
+  # Code from module std-gnu11:
+  # Code from module stdalign:
+])
+
+# This macro should be invoked from ./configure.ac, in the section
+# "Check for header files, types and library functions".
+AC_DEFUN([gl_INIT],
+[
+  AM_CONDITIONAL([GL_COND_LIBTOOL], [true])
+  gl_cond_libtool=true
+  gl_m4_base='m4'
+  m4_pushdef([AC_LIBOBJ], m4_defn([gl_LIBOBJ]))
+  m4_pushdef([AC_REPLACE_FUNCS], m4_defn([gl_REPLACE_FUNCS]))
+  m4_pushdef([AC_LIBSOURCES], m4_defn([gl_LIBSOURCES]))
+  m4_pushdef([gl_LIBSOURCES_LIST], [])
+  m4_pushdef([gl_LIBSOURCES_DIR], [])
+  gl_COMMON
+  gl_source_base='lib/gnu'
+  gl_BYTESWAP
+  AC_REQUIRE([AC_C_RESTRICT])
+  gl_MD5
+  AC_REQUIRE([gl_EXTERN_INLINE])
+  gl_STDALIGN_H
+  # End of code from modules
+  m4_ifval(gl_LIBSOURCES_LIST, [
+    m4_syscmd([test ! -d ]m4_defn([gl_LIBSOURCES_DIR])[ ||
+      for gl_file in ]gl_LIBSOURCES_LIST[ ; do
+        if test ! -r ]m4_defn([gl_LIBSOURCES_DIR])[/$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], [$gl_ltlibobjs])
+  ])
+  gltests_libdeps=
+  gltests_ltlibdeps=
+  m4_pushdef([AC_LIBOBJ], m4_defn([gltests_LIBOBJ]))
+  m4_pushdef([AC_REPLACE_FUNCS], m4_defn([gltests_REPLACE_FUNCS]))
+  m4_pushdef([AC_LIBSOURCES], m4_defn([gltests_LIBSOURCES]))
+  m4_pushdef([gltests_LIBSOURCES_LIST], [])
+  m4_pushdef([gltests_LIBSOURCES_DIR], [])
+  gl_COMMON
+  gl_source_base='tests'
+changequote(,)dnl
+  gltests_WITNESS=IN_`echo "${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], [$gl_module_indicator_condition])
+  m4_popdef([gl_MODULE_INDICATOR_CONDITION])
+  m4_ifval(gltests_LIBSOURCES_LIST, [
+    m4_syscmd([test ! -d ]m4_defn([gltests_LIBSOURCES_DIR])[ ||
+      for gl_file in ]gltests_LIBSOURCES_LIST[ ; do
+        if test ! -r ]m4_defn([gltests_LIBSOURCES_DIR])[/$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])
+  ])
+])
+
+# 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/gnu])
+      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])
+      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], [
+  lib/byteswap.in.h
+  lib/gl_openssl.h
+  lib/md5.c
+  lib/md5.h
+  lib/stdalign.in.h
+  m4/00gnulib.m4
+  m4/byteswap.m4
+  m4/extern-inline.m4
+  m4/gl-openssl.m4
+  m4/gnulib-common.m4
+  m4/md5.m4
+  m4/std-gnu11.m4
+  m4/stdalign.m4
+  m4/zzgnulib.m4
+])
diff --git a/m4/gnulib-tool.m4 b/m4/gnulib-tool.m4
new file mode 100644
index 0000000..9e1744f
--- /dev/null
+++ b/m4/gnulib-tool.m4
@@ -0,0 +1,57 @@
+# gnulib-tool.m4 serial 2
+dnl Copyright (C) 2004-2005, 2009-2020 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl The following macros need not be invoked explicitly.
+dnl Invoking them does nothing except to declare default arguments
+dnl for "gnulib-tool --import".
+
+dnl Usage: gl_LOCAL_DIR([DIR])
+AC_DEFUN([gl_LOCAL_DIR], [])
+
+dnl Usage: gl_MODULES([module1 module2 ...])
+AC_DEFUN([gl_MODULES], [])
+
+dnl Usage: gl_AVOID([module1 module2 ...])
+AC_DEFUN([gl_AVOID], [])
+
+dnl Usage: gl_SOURCE_BASE([DIR])
+AC_DEFUN([gl_SOURCE_BASE], [])
+
+dnl Usage: gl_M4_BASE([DIR])
+AC_DEFUN([gl_M4_BASE], [])
+
+dnl Usage: gl_PO_BASE([DIR])
+AC_DEFUN([gl_PO_BASE], [])
+
+dnl Usage: gl_DOC_BASE([DIR])
+AC_DEFUN([gl_DOC_BASE], [])
+
+dnl Usage: gl_TESTS_BASE([DIR])
+AC_DEFUN([gl_TESTS_BASE], [])
+
+dnl Usage: gl_WITH_TESTS
+AC_DEFUN([gl_WITH_TESTS], [])
+
+dnl Usage: gl_LIB([LIBNAME])
+AC_DEFUN([gl_LIB], [])
+
+dnl Usage: gl_LGPL or gl_LGPL([VERSION])
+AC_DEFUN([gl_LGPL], [])
+
+dnl Usage: gl_MAKEFILE_NAME([FILENAME])
+AC_DEFUN([gl_MAKEFILE_NAME], [])
+
+dnl Usage: gl_LIBTOOL
+AC_DEFUN([gl_LIBTOOL], [])
+
+dnl Usage: gl_MACRO_PREFIX([PREFIX])
+AC_DEFUN([gl_MACRO_PREFIX], [])
+
+dnl Usage: gl_PO_DOMAIN([DOMAIN])
+AC_DEFUN([gl_PO_DOMAIN], [])
+
+dnl Usage: gl_VC_FILES([BOOLEAN])
+AC_DEFUN([gl_VC_FILES], [])
diff --git a/m4/md5.m4 b/m4/md5.m4
new file mode 100644
index 0000000..ca213ed
--- /dev/null
+++ b/m4/md5.m4
@@ -0,0 +1,14 @@
+# md5.m4 serial 14
+dnl Copyright (C) 2002-2006, 2008-2020 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_MD5],
+[
+  dnl Prerequisites of lib/md5.c.
+  AC_REQUIRE([gl_BIGENDIAN])
+
+  dnl Determine HAVE_OPENSSL_MD5 and LIB_CRYPTO
+  gl_CRYPTO_CHECK([MD5])
+])
diff --git a/m4/stdalign.m4 b/m4/stdalign.m4
new file mode 100644
index 0000000..dcf778e
--- /dev/null
+++ b/m4/stdalign.m4
@@ -0,0 +1,57 @@
+# Check for stdalign.h that conforms to C11.
+
+dnl Copyright 2011-2020 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+# Prepare for substituting <stdalign.h> if it is not supported.
+
+AC_DEFUN([gl_STDALIGN_H],
+[
+  AC_CACHE_CHECK([for working stdalign.h],
+    [gl_cv_header_working_stdalign_h],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[#include <stdalign.h>
+            #include <stddef.h>
+
+            /* Test that alignof yields a result consistent with offsetof.
+               This catches GCC bug 52023
+               <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52023>.  */
+            #ifdef __cplusplus
+               template <class t> struct alignof_helper { char a; t b; };
+            # define ao(type) offsetof (alignof_helper<type>, b)
+            #else
+            # define ao(type) offsetof (struct { char a; type b; }, b)
+            #endif
+            char test_double[ao (double) % _Alignof (double) == 0 ? 1 : -1];
+            char test_long[ao (long int) % _Alignof (long int) == 0 ? 1 : -1];
+            char test_alignof[alignof (double) == _Alignof (double) ? 1 : -1];
+
+            /* Test _Alignas only on platforms where gnulib can help.  */
+            #if \
+                ((defined __cplusplus && 201103 <= __cplusplus) \
+                 || (defined __APPLE__ && defined __MACH__ \
+                     ? 4 < __GNUC__ + (1 <= __GNUC_MINOR__) \
+                     : __GNUC__) \
+                 || (__ia64 && (61200 <= __HP_cc || 61200 <= __HP_aCC)) \
+                 || __ICC || 0x590 <= __SUNPRO_C || 0x0600 <= __xlC__ \
+                 || 1300 <= _MSC_VER)
+              struct alignas_test { char c; char alignas (8) alignas_8; };
+              char test_alignas[offsetof (struct alignas_test, alignas_8) == 8
+                                ? 1 : -1];
+            #endif
+          ]])],
+       [gl_cv_header_working_stdalign_h=yes],
+       [gl_cv_header_working_stdalign_h=no])])
+
+  if test $gl_cv_header_working_stdalign_h = yes; then
+    STDALIGN_H=''
+  else
+    STDALIGN_H='stdalign.h'
+  fi
+
+  AC_SUBST([STDALIGN_H])
+  AM_CONDITIONAL([GL_GENERATE_STDALIGN_H], [test -n "$STDALIGN_H"])
+])
diff --git a/m4/version.m4 b/m4/version.m4
new file mode 100644
index 0000000..24dc5ac
--- /dev/null
+++ b/m4/version.m4
@@ -0,0 +1,2 @@
+m4_define([VERSION_NUMBER], [2.1.6])
+m4_define([PCMK_URL], [https://ClusterLabs.org/pacemaker/])
diff --git a/m4/zzgnulib.m4 b/m4/zzgnulib.m4
new file mode 100644
index 0000000..98fa68f
--- /dev/null
+++ b/m4/zzgnulib.m4
@@ -0,0 +1,23 @@
+# zzgnulib.m4 serial 1
+dnl Copyright (C) 2020 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl This file must be named something that sorts after all other
+dnl package- or gnulib-provided .m4 files - at least for those packages
+dnl that redefine AC_PROG_CC.
+
+dnl Redefine AC_PROG_CC so that it ends with invocations of gl_COMPILER_CLANG
+dnl and gl_COMPILER_PREPARE_CHECK_DECL.
+m4_define([AC_PROG_CC],
+  m4_defn([AC_PROG_CC])[
+gl_COMPILER_CLANG
+gl_COMPILER_PREPARE_CHECK_DECL
+])
+
+# gl_ZZGNULIB
+# -----------
+# Witness macro that this file has been included.  Needed to force
+# Automake to include this file after all other gnulib .m4 files.
+AC_DEFUN([gl_ZZGNULIB])