Remove autotools build system

3 files changed, 0 insertions, 1762 deletions

diff --git a/buildutil/attributes.m4 b/buildutil/attributes.m4
deleted file mode 100644
index 51ac88b..0000000
--- a/buildutil/attributes.m4
+++ /dev/null
@@ -1,292 +0,0 @@
-dnl Macros to check the presence of generic (non-typed) symbols.
-dnl Copyright (c) 2006-2008 Diego Pettenò <flameeyes@gmail.com>
-dnl Copyright (c) 2006-2008 xine project
-dnl Copyright (c) 2012 Lucas De Marchi <lucas.de.marchi@gmail.com>
-dnl
-dnl This program is free software; you can redistribute it and/or modify
-dnl it under the terms of the GNU General Public License as published by
-dnl the Free Software Foundation; either version 2, or (at your option)
-dnl any later version.
-dnl
-dnl This program is distributed in the hope that it will be useful,
-dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
-dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-dnl GNU General Public License for more details.
-dnl
-dnl You should have received a copy of the GNU General Public License
-dnl along with this program; if not, write to the Free Software
-dnl Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
-dnl 02110-1301, USA.
-dnl
-dnl As a special exception, the copyright owners of the
-dnl macro gives unlimited permission to copy, distribute and modify the
-dnl configure scripts that are the output of Autoconf when processing the
-dnl Macro. You need not follow the terms of the GNU General Public
-dnl License when using or distributing such scripts, even though portions
-dnl of the text of the Macro appear in them. The GNU General Public
-dnl License (GPL) does govern all other use of the material that
-dnl constitutes the Autoconf Macro.
-dnl
-dnl This special exception to the GPL applies to versions of the
-dnl Autoconf Macro released by this project. When you make and
-dnl distribute a modified version of the Autoconf Macro, you may extend
-dnl this special exception to the GPL to apply to your modified version as
-dnl well.
-
-dnl Check if FLAG in ENV-VAR is supported by compiler and append it
-dnl to WHERE-TO-APPEND variable. Note that we invert -Wno-* checks to
-dnl -W* as gcc cannot test for negated warnings. If a C snippet is passed,
-dnl use it, otherwise use a simple main() definition that just returns 0.
-dnl CC_CHECK_FLAG_APPEND([WHERE-TO-APPEND], [ENV-VAR], [FLAG], [C-SNIPPET])
-
-AC_DEFUN([CC_CHECK_FLAG_APPEND], [
-  AC_CACHE_CHECK([if $CC supports flag $3 in envvar $2],
-                 AS_TR_SH([cc_cv_$2_$3]),
-          [eval "AS_TR_SH([cc_save_$2])='${$2}'"
-           eval "AS_TR_SH([$2])='${cc_save_$2} -Werror `echo "$3" | sed 's/^-Wno-/-W/'`'"
-           AC_LINK_IFELSE([AC_LANG_SOURCE(ifelse([$4], [],
-                                                 [int main(void) { return 0; } ],
-                                                 [$4]))],
-                          [eval "AS_TR_SH([cc_cv_$2_$3])='yes'"],
-                          [eval "AS_TR_SH([cc_cv_$2_$3])='no'"])
-           eval "AS_TR_SH([$2])='$cc_save_$2'"])
-
-  AS_IF([eval test x$]AS_TR_SH([cc_cv_$2_$3])[ = xyes],
-        [eval "$1='${$1} $3'"])
-])
-
-dnl CC_CHECK_FLAGS_APPEND([WHERE-TO-APPEND], [ENV-VAR], [FLAG1 FLAG2], [C-SNIPPET])
-AC_DEFUN([CC_CHECK_FLAGS_APPEND], [
-  for flag in [$3]; do
-    CC_CHECK_FLAG_APPEND([$1], [$2], $flag, [$4])
-  done
-])
-
-dnl Check if the flag is supported by linker (cacheable)
-dnl CC_CHECK_LDFLAGS([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND])
-
-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([int main() { return 1; }],
-       [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])
-])
-
-dnl define the LDFLAGS_NOUNDEFINED variable with the correct value for
-dnl the current linker to avoid undefined references in a shared object.
-AC_DEFUN([CC_NOUNDEFINED], [
-  dnl We check $host for which systems to enable this for.
-  AC_REQUIRE([AC_CANONICAL_HOST])
-
-  case $host in
-     dnl FreeBSD (et al.) does not complete linking for shared objects when pthreads
-     dnl are requested, as different implementations are present; to avoid problems
-     dnl use -Wl,-z,defs only for those platform not behaving this way.
-     *-freebsd* | *-openbsd*) ;;
-     *)
-        dnl First of all check for the --no-undefined variant of GNU ld. This allows
-        dnl for a much more readable command line, so that people can understand what
-        dnl it does without going to look for what the heck -z defs does.
-        for possible_flags in "-Wl,--no-undefined" "-Wl,-z,defs"; do
-           CC_CHECK_LDFLAGS([$possible_flags], [LDFLAGS_NOUNDEFINED="$possible_flags"])
-           break
-        done
-     ;;
-  esac
-
-  AC_SUBST([LDFLAGS_NOUNDEFINED])
-])
-
-dnl Check for a -Werror flag or equivalent. -Werror is the GCC
-dnl and ICC flag that tells the compiler to treat all the warnings
-dnl as fatal. We usually need this option to make sure that some
-dnl constructs (like attributes) are not simply ignored.
-dnl
-dnl Other compilers don't support -Werror per se, but they support
-dnl an equivalent flag:
-dnl  - Sun Studio compiler supports -errwarn=%all
-AC_DEFUN([CC_CHECK_WERROR], [
-  AC_CACHE_CHECK(
-    [for $CC way to treat warnings as errors],
-    [cc_cv_werror],
-    [CC_CHECK_CFLAGS_SILENT([-Werror], [cc_cv_werror=-Werror],
-      [CC_CHECK_CFLAGS_SILENT([-errwarn=%all], [cc_cv_werror=-errwarn=%all])])
-    ])
-])
-
-AC_DEFUN([CC_CHECK_ATTRIBUTE], [
-  AC_REQUIRE([CC_CHECK_WERROR])
-  AC_CACHE_CHECK([if $CC supports __attribute__(( ifelse([$2], , [$1], [$2]) ))],
-    AS_TR_SH([cc_cv_attribute_$1]),
-    [ac_save_CFLAGS="$CFLAGS"
-     CFLAGS="$CFLAGS $cc_cv_werror"
-     AC_COMPILE_IFELSE([AC_LANG_SOURCE([$3])],
-       [eval "AS_TR_SH([cc_cv_attribute_$1])='yes'"],
-       [eval "AS_TR_SH([cc_cv_attribute_$1])='no'"])
-     CFLAGS="$ac_save_CFLAGS"
-    ])
-
-  AS_IF([eval test x$]AS_TR_SH([cc_cv_attribute_$1])[ = xyes],
-    [AC_DEFINE(
-       AS_TR_CPP([SUPPORT_ATTRIBUTE_$1]), 1,
-         [Define this if the compiler supports __attribute__(( ifelse([$2], , [$1], [$2]) ))]
-         )
-     $4],
-    [$5])
-])
-
-AC_DEFUN([CC_ATTRIBUTE_CONSTRUCTOR], [
-  CC_CHECK_ATTRIBUTE(
-    [constructor],,
-    [void __attribute__((constructor)) ctor() { int a; }],
-    [$1], [$2])
-])
-
-AC_DEFUN([CC_ATTRIBUTE_FORMAT], [
-  CC_CHECK_ATTRIBUTE(
-    [format], [format(printf, n, n)],
-    [void __attribute__((format(printf, 1, 2))) printflike(const char *fmt, ...) { fmt = (void *)0; }],
-    [$1], [$2])
-])
-
-AC_DEFUN([CC_ATTRIBUTE_FORMAT_ARG], [
-  CC_CHECK_ATTRIBUTE(
-    [format_arg], [format_arg(printf)],
-    [char *__attribute__((format_arg(1))) gettextlike(const char *fmt) { fmt = (void *)0; }],
-    [$1], [$2])
-])
-
-AC_DEFUN([CC_ATTRIBUTE_VISIBILITY], [
-  CC_CHECK_ATTRIBUTE(
-    [visibility_$1], [visibility("$1")],
-    [void __attribute__((visibility("$1"))) $1_function() { }],
-    [$2], [$3])
-])
-
-AC_DEFUN([CC_ATTRIBUTE_NONNULL], [
-  CC_CHECK_ATTRIBUTE(
-    [nonnull], [nonnull()],
-    [void __attribute__((nonnull())) some_function(void *foo, void *bar) { foo = (void*)0; bar = (void*)0; }],
-    [$1], [$2])
-])
-
-AC_DEFUN([CC_ATTRIBUTE_UNUSED], [
-  CC_CHECK_ATTRIBUTE(
-    [unused], ,
-    [void some_function(void *foo, __attribute__((unused)) void *bar);],
-    [$1], [$2])
-])
-
-AC_DEFUN([CC_ATTRIBUTE_SENTINEL], [
-  CC_CHECK_ATTRIBUTE(
-    [sentinel], ,
-    [void some_function(void *foo, ...) __attribute__((sentinel));],
-    [$1], [$2])
-])
-
-AC_DEFUN([CC_ATTRIBUTE_DEPRECATED], [
-  CC_CHECK_ATTRIBUTE(
-    [deprecated], ,
-    [void some_function(void *foo, ...) __attribute__((deprecated));],
-    [$1], [$2])
-])
-
-AC_DEFUN([CC_ATTRIBUTE_ALIAS], [
-  CC_CHECK_ATTRIBUTE(
-    [alias], [weak, alias],
-    [void other_function(void *foo) { }
-     void some_function(void *foo) __attribute__((weak, alias("other_function")));],
-    [$1], [$2])
-])
-
-AC_DEFUN([CC_ATTRIBUTE_MALLOC], [
-  CC_CHECK_ATTRIBUTE(
-    [malloc], ,
-    [void * __attribute__((malloc)) my_alloc(int n);],
-    [$1], [$2])
-])
-
-AC_DEFUN([CC_ATTRIBUTE_PACKED], [
-  CC_CHECK_ATTRIBUTE(
-    [packed], ,
-    [struct astructure { char a; int b; long c; void *d; } __attribute__((packed));],
-    [$1], [$2])
-])
-
-AC_DEFUN([CC_ATTRIBUTE_CONST], [
-  CC_CHECK_ATTRIBUTE(
-    [const], ,
-    [int __attribute__((const)) twopow(int n) { return 1 << n; } ],
-    [$1], [$2])
-])
-
-AC_DEFUN([CC_FLAG_VISIBILITY], [
-  AC_REQUIRE([CC_CHECK_WERROR])
-  AC_CACHE_CHECK([if $CC supports -fvisibility=hidden],
-    [cc_cv_flag_visibility],
-    [cc_flag_visibility_save_CFLAGS="$CFLAGS"
-     CFLAGS="$CFLAGS $cc_cv_werror"
-     CC_CHECK_CFLAGS_SILENT([-fvisibility=hidden],
-     cc_cv_flag_visibility='yes',
-     cc_cv_flag_visibility='no')
-     CFLAGS="$cc_flag_visibility_save_CFLAGS"])
-
-  AS_IF([test "x$cc_cv_flag_visibility" = "xyes"],
-    [AC_DEFINE([SUPPORT_FLAG_VISIBILITY], 1,
-       [Define this if the compiler supports the -fvisibility flag])
-     $1],
-    [$2])
-])
-
-AC_DEFUN([CC_FUNC_EXPECT], [
-  AC_REQUIRE([CC_CHECK_WERROR])
-  AC_CACHE_CHECK([if compiler has __builtin_expect function],
-    [cc_cv_func_expect],
-    [ac_save_CFLAGS="$CFLAGS"
-     CFLAGS="$CFLAGS $cc_cv_werror"
-     AC_COMPILE_IFELSE([AC_LANG_SOURCE(
-       [int some_function() {
-        int a = 3;
-        return (int)__builtin_expect(a, 3);
-     }])],
-       [cc_cv_func_expect=yes],
-       [cc_cv_func_expect=no])
-     CFLAGS="$ac_save_CFLAGS"
-    ])
-
-  AS_IF([test "x$cc_cv_func_expect" = "xyes"],
-    [AC_DEFINE([SUPPORT__BUILTIN_EXPECT], 1,
-     [Define this if the compiler supports __builtin_expect() function])
-     $1],
-    [$2])
-])
-
-AC_DEFUN([CC_ATTRIBUTE_ALIGNED], [
-  AC_REQUIRE([CC_CHECK_WERROR])
-  AC_CACHE_CHECK([highest __attribute__ ((aligned ())) supported],
-    [cc_cv_attribute_aligned],
-    [ac_save_CFLAGS="$CFLAGS"
-     CFLAGS="$CFLAGS $cc_cv_werror"
-     for cc_attribute_align_try in 64 32 16 8 4 2; do
-        AC_COMPILE_IFELSE([AC_LANG_SOURCE([
-          int main() {
-            static char c __attribute__ ((aligned($cc_attribute_align_try))) = 0;
-            return c;
-          }])], [cc_cv_attribute_aligned=$cc_attribute_align_try; break])
-     done
-     CFLAGS="$ac_save_CFLAGS"
-  ])
-
-  if test "x$cc_cv_attribute_aligned" != "x"; then
-     AC_DEFINE_UNQUOTED([ATTRIBUTE_ALIGNED_MAX], [$cc_cv_attribute_aligned],
-       [Define the highest alignment supported])
-  fi
-])
diff --git a/buildutil/ax_cxx_compile_stdcxx.m4 b/buildutil/ax_cxx_compile_stdcxx.m4
deleted file mode 100644
index 9e9eaed..0000000
--- a/buildutil/ax_cxx_compile_stdcxx.m4
+++ /dev/null
@@ -1,948 +0,0 @@
-# ===========================================================================
-#  https://www.gnu.org/software/autoconf-archive/ax_cxx_compile_stdcxx.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_CXX_COMPILE_STDCXX(VERSION, [ext|noext], [mandatory|optional])
-#
-# DESCRIPTION
-#
-#   Check for baseline language coverage in the compiler for the specified
-#   version of the C++ standard.  If necessary, add switches to CXX and
-#   CXXCPP to enable support.  VERSION may be '11' (for the C++11 standard)
-#   or '14' (for the C++14 standard).
-#
-#   The second argument, if specified, indicates whether you insist on an
-#   extended mode (e.g. -std=gnu++11) or a strict conformance mode (e.g.
-#   -std=c++11).  If neither is specified, you get whatever works, with
-#   preference for an extended mode.
-#
-#   The third argument, if specified 'mandatory' or if left unspecified,
-#   indicates that baseline support for the specified C++ standard is
-#   required and that the macro should error out if no mode with that
-#   support is found.  If specified 'optional', then configuration proceeds
-#   regardless, after defining HAVE_CXX${VERSION} if and only if a
-#   supporting mode is found.
-#
-# LICENSE
-#
-#   Copyright (c) 2008 Benjamin Kosnik <bkoz@redhat.com>
-#   Copyright (c) 2012 Zack Weinberg <zackw@panix.com>
-#   Copyright (c) 2013 Roy Stogner <roystgnr@ices.utexas.edu>
-#   Copyright (c) 2014, 2015 Google Inc.; contributed by Alexey Sokolov <sokolov@google.com>
-#   Copyright (c) 2015 Paul Norman <penorman@mac.com>
-#   Copyright (c) 2015 Moritz Klammler <moritz@klammler.eu>
-#   Copyright (c) 2016, 2018 Krzesimir Nowak <qdlacz@gmail.com>
-#
-#   Copying and distribution of this file, with or without modification, are
-#   permitted in any medium without royalty provided the copyright notice
-#   and this notice are preserved.  This file is offered as-is, without any
-#   warranty.
-
-#serial 10
-
-dnl  This macro is based on the code from the AX_CXX_COMPILE_STDCXX_11 macro
-dnl  (serial version number 13).
-
-AC_DEFUN([AX_CXX_COMPILE_STDCXX], [dnl
-  m4_if([$1], [11], [ax_cxx_compile_alternatives="11 0x"],
-        [$1], [14], [ax_cxx_compile_alternatives="14 1y"],
-        [$1], [17], [ax_cxx_compile_alternatives="17 1z"],
-        [m4_fatal([invalid first argument `$1' to AX_CXX_COMPILE_STDCXX])])dnl
-  m4_if([$2], [], [],
-        [$2], [ext], [],
-        [$2], [noext], [],
-        [m4_fatal([invalid second argument `$2' to AX_CXX_COMPILE_STDCXX])])dnl
-  m4_if([$3], [], [ax_cxx_compile_cxx$1_required=true],
-        [$3], [mandatory], [ax_cxx_compile_cxx$1_required=true],
-        [$3], [optional], [ax_cxx_compile_cxx$1_required=false],
-        [m4_fatal([invalid third argument `$3' to AX_CXX_COMPILE_STDCXX])])
-  AC_LANG_PUSH([C++])dnl
-  ac_success=no
-
-  m4_if([$2], [noext], [], [dnl
-  if test x$ac_success = xno; then
-    for alternative in ${ax_cxx_compile_alternatives}; do
-      switch="-std=gnu++${alternative}"
-      cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch])
-      AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch,
-                     $cachevar,
-        [ac_save_CXX="$CXX"
-         CXX="$CXX $switch"
-         AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])],
-          [eval $cachevar=yes],
-          [eval $cachevar=no])
-         CXX="$ac_save_CXX"])
-      if eval test x\$$cachevar = xyes; then
-        CXX="$CXX $switch"
-        if test -n "$CXXCPP" ; then
-          CXXCPP="$CXXCPP $switch"
-        fi
-        ac_success=yes
-        break
-      fi
-    done
-  fi])
-
-  m4_if([$2], [ext], [], [dnl
-  if test x$ac_success = xno; then
-    dnl HP's aCC needs +std=c++11 according to:
-    dnl http://h21007.www2.hp.com/portal/download/files/unprot/aCxx/PDF_Release_Notes/769149-001.pdf
-    dnl Cray's crayCC needs "-h std=c++11"
-    for alternative in ${ax_cxx_compile_alternatives}; do
-      for switch in -std=c++${alternative} +std=c++${alternative} "-h std=c++${alternative}"; do
-        cachevar=AS_TR_SH([ax_cv_cxx_compile_cxx$1_$switch])
-        AC_CACHE_CHECK(whether $CXX supports C++$1 features with $switch,
-                       $cachevar,
-          [ac_save_CXX="$CXX"
-           CXX="$CXX $switch"
-           AC_COMPILE_IFELSE([AC_LANG_SOURCE([_AX_CXX_COMPILE_STDCXX_testbody_$1])],
-            [eval $cachevar=yes],
-            [eval $cachevar=no])
-           CXX="$ac_save_CXX"])
-        if eval test x\$$cachevar = xyes; then
-          CXX="$CXX $switch"
-          if test -n "$CXXCPP" ; then
-            CXXCPP="$CXXCPP $switch"
-          fi
-          ac_success=yes
-          break
-        fi
-      done
-      if test x$ac_success = xyes; then
-        break
-      fi
-    done
-  fi])
-  AC_LANG_POP([C++])
-  if test x$ax_cxx_compile_cxx$1_required = xtrue; then
-    if test x$ac_success = xno; then
-      AC_MSG_ERROR([*** A compiler with support for C++$1 language features is required.])
-    fi
-  fi
-  if test x$ac_success = xno; then
-    HAVE_CXX$1=0
-    AC_MSG_NOTICE([No compiler with C++$1 support was found])
-  else
-    HAVE_CXX$1=1
-    AC_DEFINE(HAVE_CXX$1,1,
-              [define if the compiler supports basic C++$1 syntax])
-  fi
-  AC_SUBST(HAVE_CXX$1)
-])
-
-
-dnl  Test body for checking C++11 support
-
-m4_define([_AX_CXX_COMPILE_STDCXX_testbody_11],
-  _AX_CXX_COMPILE_STDCXX_testbody_new_in_11
-)
-
-
-dnl  Test body for checking C++14 support
-
-m4_define([_AX_CXX_COMPILE_STDCXX_testbody_14],
-  _AX_CXX_COMPILE_STDCXX_testbody_new_in_11
-  _AX_CXX_COMPILE_STDCXX_testbody_new_in_14
-)
-
-m4_define([_AX_CXX_COMPILE_STDCXX_testbody_17],
-  _AX_CXX_COMPILE_STDCXX_testbody_new_in_11
-  _AX_CXX_COMPILE_STDCXX_testbody_new_in_14
-  _AX_CXX_COMPILE_STDCXX_testbody_new_in_17
-)
-
-dnl  Tests for new features in C++11
-
-m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_11], [[
-
-// If the compiler admits that it is not ready for C++11, why torture it?
-// Hopefully, this will speed up the test.
-
-#ifndef __cplusplus
-
-#error "This is not a C++ compiler"
-
-#elif __cplusplus < 201103L
-
-#error "This is not a C++11 compiler"
-
-#else
-
-namespace cxx11
-{
-
-  namespace test_static_assert
-  {
-
-    template <typename T>
-    struct check
-    {
-      static_assert(sizeof(int) <= sizeof(T), "not big enough");
-    };
-
-  }
-
-  namespace test_final_override
-  {
-
-    struct Base
-    {
-      virtual void f() {}
-    };
-
-    struct Derived : public Base
-    {
-      virtual void f() override {}
-    };
-
-  }
-
-  namespace test_double_right_angle_brackets
-  {
-
-    template < typename T >
-    struct check {};
-
-    typedef check<void> single_type;
-    typedef check<check<void>> double_type;
-    typedef check<check<check<void>>> triple_type;
-    typedef check<check<check<check<void>>>> quadruple_type;
-
-  }
-
-  namespace test_decltype
-  {
-
-    int
-    f()
-    {
-      int a = 1;
-      decltype(a) b = 2;
-      return a + b;
-    }
-
-  }
-
-  namespace test_type_deduction
-  {
-
-    template < typename T1, typename T2 >
-    struct is_same
-    {
-      static const bool value = false;
-    };
-
-    template < typename T >
-    struct is_same<T, T>
-    {
-      static const bool value = true;
-    };
-
-    template < typename T1, typename T2 >
-    auto
-    add(T1 a1, T2 a2) -> decltype(a1 + a2)
-    {
-      return a1 + a2;
-    }
-
-    int
-    test(const int c, volatile int v)
-    {
-      static_assert(is_same<int, decltype(0)>::value == true, "");
-      static_assert(is_same<int, decltype(c)>::value == false, "");
-      static_assert(is_same<int, decltype(v)>::value == false, "");
-      auto ac = c;
-      auto av = v;
-      auto sumi = ac + av + 'x';
-      auto sumf = ac + av + 1.0;
-      static_assert(is_same<int, decltype(ac)>::value == true, "");
-      static_assert(is_same<int, decltype(av)>::value == true, "");
-      static_assert(is_same<int, decltype(sumi)>::value == true, "");
-      static_assert(is_same<int, decltype(sumf)>::value == false, "");
-      static_assert(is_same<int, decltype(add(c, v))>::value == true, "");
-      return (sumf > 0.0) ? sumi : add(c, v);
-    }
-
-  }
-
-  namespace test_noexcept
-  {
-
-    int f() { return 0; }
-    int g() noexcept { return 0; }
-
-    static_assert(noexcept(f()) == false, "");
-    static_assert(noexcept(g()) == true, "");
-
-  }
-
-  namespace test_constexpr
-  {
-
-    template < typename CharT >
-    unsigned long constexpr
-    strlen_c_r(const CharT *const s, const unsigned long acc) noexcept
-    {
-      return *s ? strlen_c_r(s + 1, acc + 1) : acc;
-    }
-
-    template < typename CharT >
-    unsigned long constexpr
-    strlen_c(const CharT *const s) noexcept
-    {
-      return strlen_c_r(s, 0UL);
-    }
-
-    static_assert(strlen_c("") == 0UL, "");
-    static_assert(strlen_c("1") == 1UL, "");
-    static_assert(strlen_c("example") == 7UL, "");
-    static_assert(strlen_c("another\0example") == 7UL, "");
-
-  }
-
-  namespace test_rvalue_references
-  {
-
-    template < int N >
-    struct answer
-    {
-      static constexpr int value = N;
-    };
-
-    answer<1> f(int&)       { return answer<1>(); }
-    answer<2> f(const int&) { return answer<2>(); }
-    answer<3> f(int&&)      { return answer<3>(); }
-
-    void
-    test()
-    {
-      int i = 0;
-      const int c = 0;
-      static_assert(decltype(f(i))::value == 1, "");
-      static_assert(decltype(f(c))::value == 2, "");
-      static_assert(decltype(f(0))::value == 3, "");
-    }
-
-  }
-
-  namespace test_uniform_initialization
-  {
-
-    struct test
-    {
-      static const int zero {};
-      static const int one {1};
-    };
-
-    static_assert(test::zero == 0, "");
-    static_assert(test::one == 1, "");
-
-  }
-
-  namespace test_lambdas
-  {
-
-    void
-    test1()
-    {
-      auto lambda1 = [](){};
-      auto lambda2 = lambda1;
-      lambda1();
-      lambda2();
-    }
-
-    int
-    test2()
-    {
-      auto a = [](int i, int j){ return i + j; }(1, 2);
-      auto b = []() -> int { return '0'; }();
-      auto c = [=](){ return a + b; }();
-      auto d = [&](){ return c; }();
-      auto e = [a, &b](int x) mutable {
-        const auto identity = [](int y){ return y; };
-        for (auto i = 0; i < a; ++i)
-          a += b--;
-        return x + identity(a + b);
-      }(0);
-      return a + b + c + d + e;
-    }
-
-    int
-    test3()
-    {
-      const auto nullary = [](){ return 0; };
-      const auto unary = [](int x){ return x; };
-      using nullary_t = decltype(nullary);
-      using unary_t = decltype(unary);
-      const auto higher1st = [](nullary_t f){ return f(); };
-      const auto higher2nd = [unary](nullary_t f1){
-        return [unary, f1](unary_t f2){ return f2(unary(f1())); };
-      };
-      return higher1st(nullary) + higher2nd(nullary)(unary);
-    }
-
-  }
-
-  namespace test_variadic_templates
-  {
-
-    template <int...>
-    struct sum;
-
-    template <int N0, int... N1toN>
-    struct sum<N0, N1toN...>
-    {
-      static constexpr auto value = N0 + sum<N1toN...>::value;
-    };
-
-    template <>
-    struct sum<>
-    {
-      static constexpr auto value = 0;
-    };
-
-    static_assert(sum<>::value == 0, "");
-    static_assert(sum<1>::value == 1, "");
-    static_assert(sum<23>::value == 23, "");
-    static_assert(sum<1, 2>::value == 3, "");
-    static_assert(sum<5, 5, 11>::value == 21, "");
-    static_assert(sum<2, 3, 5, 7, 11, 13>::value == 41, "");
-
-  }
-
-  // http://stackoverflow.com/questions/13728184/template-aliases-and-sfinae
-  // Clang 3.1 fails with headers of libstd++ 4.8.3 when using std::function
-  // because of this.
-  namespace test_template_alias_sfinae
-  {
-
-    struct foo {};
-
-    template<typename T>
-    using member = typename T::member_type;
-
-    template<typename T>
-    void func(...) {}
-
-    template<typename T>
-    void func(member<T>*) {}
-
-    void test();
-
-    void test() { func<foo>(0); }
-
-  }
-
-}  // namespace cxx11
-
-#endif  // __cplusplus >= 201103L
-
-]])
-
-
-dnl  Tests for new features in C++14
-
-m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_14], [[
-
-// If the compiler admits that it is not ready for C++14, why torture it?
-// Hopefully, this will speed up the test.
-
-#ifndef __cplusplus
-
-#error "This is not a C++ compiler"
-
-#elif __cplusplus < 201402L
-
-#error "This is not a C++14 compiler"
-
-#else
-
-namespace cxx14
-{
-
-  namespace test_polymorphic_lambdas
-  {
-
-    int
-    test()
-    {
-      const auto lambda = [](auto&&... args){
-        const auto istiny = [](auto x){
-          return (sizeof(x) == 1UL) ? 1 : 0;
-        };
-        const int aretiny[] = { istiny(args)... };
-        return aretiny[0];
-      };
-      return lambda(1, 1L, 1.0f, '1');
-    }
-
-  }
-
-  namespace test_binary_literals
-  {
-
-    constexpr auto ivii = 0b0000000000101010;
-    static_assert(ivii == 42, "wrong value");
-
-  }
-
-  namespace test_generalized_constexpr
-  {
-
-    template < typename CharT >
-    constexpr unsigned long
-    strlen_c(const CharT *const s) noexcept
-    {
-      auto length = 0UL;
-      for (auto p = s; *p; ++p)
-        ++length;
-      return length;
-    }
-
-    static_assert(strlen_c("") == 0UL, "");
-    static_assert(strlen_c("x") == 1UL, "");
-    static_assert(strlen_c("test") == 4UL, "");
-    static_assert(strlen_c("another\0test") == 7UL, "");
-
-  }
-
-  namespace test_lambda_init_capture
-  {
-
-    int
-    test()
-    {
-      auto x = 0;
-      const auto lambda1 = [a = x](int b){ return a + b; };
-      const auto lambda2 = [a = lambda1(x)](){ return a; };
-      return lambda2();
-    }
-
-  }
-
-  namespace test_digit_separators
-  {
-
-    constexpr auto ten_million = 100'000'000;
-    static_assert(ten_million == 100000000, "");
-
-  }
-
-  namespace test_return_type_deduction
-  {
-
-    auto f(int& x) { return x; }
-    decltype(auto) g(int& x) { return x; }
-
-    template < typename T1, typename T2 >
-    struct is_same
-    {
-      static constexpr auto value = false;
-    };
-
-    template < typename T >
-    struct is_same<T, T>
-    {
-      static constexpr auto value = true;
-    };
-
-    int
-    test()
-    {
-      auto x = 0;
-      static_assert(is_same<int, decltype(f(x))>::value, "");
-      static_assert(is_same<int&, decltype(g(x))>::value, "");
-      return x;
-    }
-
-  }
-
-}  // namespace cxx14
-
-#endif  // __cplusplus >= 201402L
-
-]])
-
-
-dnl  Tests for new features in C++17
-
-m4_define([_AX_CXX_COMPILE_STDCXX_testbody_new_in_17], [[
-
-// If the compiler admits that it is not ready for C++17, why torture it?
-// Hopefully, this will speed up the test.
-
-#ifndef __cplusplus
-
-#error "This is not a C++ compiler"
-
-#elif __cplusplus < 201703L
-
-#error "This is not a C++17 compiler"
-
-#else
-
-#include <initializer_list>
-#include <utility>
-#include <type_traits>
-
-namespace cxx17
-{
-
-  namespace test_constexpr_lambdas
-  {
-
-    constexpr int foo = [](){return 42;}();
-
-  }
-
-  namespace test::nested_namespace::definitions
-  {
-
-  }
-
-  namespace test_fold_expression
-  {
-
-    template<typename... Args>
-    int multiply(Args... args)
-    {
-      return (args * ... * 1);
-    }
-
-    template<typename... Args>
-    bool all(Args... args)
-    {
-      return (args && ...);
-    }
-
-  }
-
-  namespace test_extended_static_assert
-  {
-
-    static_assert (true);
-
-  }
-
-  namespace test_auto_brace_init_list
-  {
-
-    auto foo = {5};
-    auto bar {5};
-
-    static_assert(std::is_same<std::initializer_list<int>, decltype(foo)>::value);
-    static_assert(std::is_same<int, decltype(bar)>::value);
-  }
-
-  namespace test_typename_in_template_template_parameter
-  {
-
-    template<template<typename> typename X> struct D;
-
-  }
-
-  namespace test_fallthrough_nodiscard_maybe_unused_attributes
-  {
-
-    int f1()
-    {
-      return 42;
-    }
-
-    [[nodiscard]] int f2()
-    {
-      [[maybe_unused]] auto unused = f1();
-
-      switch (f1())
-      {
-      case 17:
-        f1();
-        [[fallthrough]];
-      case 42:
-        f1();
-      }
-      return f1();
-    }
-
-  }
-
-  namespace test_extended_aggregate_initialization
-  {
-
-    struct base1
-    {
-      int b1, b2 = 42;
-    };
-
-    struct base2
-    {
-      base2() {
-        b3 = 42;
-      }
-      int b3;
-    };
-
-    struct derived : base1, base2
-    {
-        int d;
-    };
-
-    derived d1 {{1, 2}, {}, 4};  // full initialization
-    derived d2 {{}, {}, 4};      // value-initialized bases
-
-  }
-
-  namespace test_general_range_based_for_loop
-  {
-
-    struct iter
-    {
-      int i;
-
-      int& operator* ()
-      {
-        return i;
-      }
-
-      const int& operator* () const
-      {
-        return i;
-      }
-
-      iter& operator++()
-      {
-        ++i;
-        return *this;
-      }
-    };
-
-    struct sentinel
-    {
-      int i;
-    };
-
-    bool operator== (const iter& i, const sentinel& s)
-    {
-      return i.i == s.i;
-    }
-
-    bool operator!= (const iter& i, const sentinel& s)
-    {
-      return !(i == s);
-    }
-
-    struct range
-    {
-      iter begin() const
-      {
-        return {0};
-      }
-
-      sentinel end() const
-      {
-        return {5};
-      }
-    };
-
-    void f()
-    {
-      range r {};
-
-      for (auto i : r)
-      {
-        [[maybe_unused]] auto v = i;
-      }
-    }
-
-  }
-
-  namespace test_lambda_capture_asterisk_this_by_value
-  {
-
-    struct t
-    {
-      int i;
-      int foo()
-      {
-        return [*this]()
-        {
-          return i;
-        }();
-      }
-    };
-
-  }
-
-  namespace test_enum_class_construction
-  {
-
-    enum class byte : unsigned char
-    {};
-
-    byte foo {42};
-
-  }
-
-  namespace test_constexpr_if
-  {
-
-    template <bool cond>
-    int f ()
-    {
-      if constexpr(cond)
-      {
-        return 13;
-      }
-      else
-      {
-        return 42;
-      }
-    }
-
-  }
-
-  namespace test_selection_statement_with_initializer
-  {
-
-    int f()
-    {
-      return 13;
-    }
-
-    int f2()
-    {
-      if (auto i = f(); i > 0)
-      {
-        return 3;
-      }
-
-      switch (auto i = f(); i + 4)
-      {
-      case 17:
-        return 2;
-
-      default:
-        return 1;
-      }
-    }
-
-  }
-
-  namespace test_template_argument_deduction_for_class_templates
-  {
-
-    template <typename T1, typename T2>
-    struct pair
-    {
-      pair (T1 p1, T2 p2)
-        : m1 {p1},
-          m2 {p2}
-      {}
-
-      T1 m1;
-      T2 m2;
-    };
-
-    void f()
-    {
-      [[maybe_unused]] auto p = pair{13, 42u};
-    }
-
-  }
-
-  namespace test_non_type_auto_template_parameters
-  {
-
-    template <auto n>
-    struct B
-    {};
-
-    B<5> b1;
-    B<'a'> b2;
-
-  }
-
-  namespace test_structured_bindings
-  {
-
-    int arr[2] = { 1, 2 };
-    std::pair<int, int> pr = { 1, 2 };
-
-    auto f1() -> int(&)[2]
-    {
-      return arr;
-    }
-
-    auto f2() -> std::pair<int, int>&
-    {
-      return pr;
-    }
-
-    struct S
-    {
-      int x1 : 2;
-      volatile double y1;
-    };
-
-    S f3()
-    {
-      return {};
-    }
-
-    auto [ x1, y1 ] = f1();
-    auto& [ xr1, yr1 ] = f1();
-    auto [ x2, y2 ] = f2();
-    auto& [ xr2, yr2 ] = f2();
-    const auto [ x3, y3 ] = f3();
-
-  }
-
-  namespace test_exception_spec_type_system
-  {
-
-    struct Good {};
-    struct Bad {};
-
-    void g1() noexcept;
-    void g2();
-
-    template<typename T>
-    Bad
-    f(T*, T*);
-
-    template<typename T1, typename T2>
-    Good
-    f(T1*, T2*);
-
-    static_assert (std::is_same_v<Good, decltype(f(g1, g2))>);
-
-  }
-
-  namespace test_inline_variables
-  {
-
-    template<class T> void f(T)
-    {}
-
-    template<class T> inline T g(T)
-    {
-      return T{};
-    }
-
-    template<> inline void f<>(int)
-    {}
-
-    template<> int g<>(int)
-    {
-      return 5;
-    }
-
-  }
-
-}  // namespace cxx17
-
-#endif  // __cplusplus < 201703L
-
-]])
diff --git a/buildutil/ax_pthread.m4 b/buildutil/ax_pthread.m4
deleted file mode 100644
index 9f35d13..0000000
--- a/buildutil/ax_pthread.m4
+++ /dev/null
@@ -1,522 +0,0 @@
-# ===========================================================================
-#        https://www.gnu.org/software/autoconf-archive/ax_pthread.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
-#
-# DESCRIPTION
-#
-#   This macro figures out how to build C programs using POSIX threads. It
-#   sets the PTHREAD_LIBS output variable to the threads library and linker
-#   flags, and the PTHREAD_CFLAGS output variable to any special C compiler
-#   flags that are needed. (The user can also force certain compiler
-#   flags/libs to be tested by setting these environment variables.)
-#
-#   Also sets PTHREAD_CC and PTHREAD_CXX to any special C compiler that is
-#   needed for multi-threaded programs (defaults to the value of CC
-#   respectively CXX otherwise). (This is necessary on e.g. AIX to use the
-#   special cc_r/CC_r compiler alias.)
-#
-#   NOTE: You are assumed to not only compile your program with these flags,
-#   but also to link with them as well. For example, you might link with
-#   $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS $LIBS
-#   $PTHREAD_CXX $CXXFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS $LIBS
-#
-#   If you are only building threaded programs, you may wish to use these
-#   variables in your default LIBS, CFLAGS, and CC:
-#
-#     LIBS="$PTHREAD_LIBS $LIBS"
-#     CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
-#     CXXFLAGS="$CXXFLAGS $PTHREAD_CFLAGS"
-#     CC="$PTHREAD_CC"
-#     CXX="$PTHREAD_CXX"
-#
-#   In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute constant
-#   has a nonstandard name, this macro defines PTHREAD_CREATE_JOINABLE to
-#   that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
-#
-#   Also HAVE_PTHREAD_PRIO_INHERIT is defined if pthread is found and the
-#   PTHREAD_PRIO_INHERIT symbol is defined when compiling with
-#   PTHREAD_CFLAGS.
-#
-#   ACTION-IF-FOUND is a list of shell commands to run if a threads library
-#   is found, and ACTION-IF-NOT-FOUND is a list of commands to run it if it
-#   is not found. If ACTION-IF-FOUND is not specified, the default action
-#   will define HAVE_PTHREAD.
-#
-#   Please let the authors know if this macro fails on any platform, or if
-#   you have any other suggestions or comments. This macro was based on work
-#   by SGJ on autoconf scripts for FFTW (http://www.fftw.org/) (with help
-#   from M. Frigo), as well as ac_pthread and hb_pthread macros posted by
-#   Alejandro Forero Cuervo to the autoconf macro repository. We are also
-#   grateful for the helpful feedback of numerous users.
-#
-#   Updated for Autoconf 2.68 by Daniel Richard G.
-#
-# LICENSE
-#
-#   Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu>
-#   Copyright (c) 2011 Daniel Richard G. <skunk@iSKUNK.ORG>
-#   Copyright (c) 2019 Marc Stevens <marc.stevens@cwi.nl>
-#
-#   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 31
-
-AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD])
-AC_DEFUN([AX_PTHREAD], [
-AC_REQUIRE([AC_CANONICAL_HOST])
-AC_REQUIRE([AC_PROG_CC])
-AC_REQUIRE([AC_PROG_SED])
-AC_LANG_PUSH([C])
-ax_pthread_ok=no
-
-# We used to check for pthread.h first, but this fails if pthread.h
-# requires special compiler flags (e.g. on Tru64 or Sequent).
-# It gets checked for in the link test anyway.
-
-# First of all, check if the user has set any of the PTHREAD_LIBS,
-# etcetera environment variables, and if threads linking works using
-# them:
-if test "x$PTHREAD_CFLAGS$PTHREAD_LIBS" != "x"; then
-        ax_pthread_save_CC="$CC"
-        ax_pthread_save_CFLAGS="$CFLAGS"
-        ax_pthread_save_LIBS="$LIBS"
-        AS_IF([test "x$PTHREAD_CC" != "x"], [CC="$PTHREAD_CC"])
-        AS_IF([test "x$PTHREAD_CXX" != "x"], [CXX="$PTHREAD_CXX"])
-        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
-        LIBS="$PTHREAD_LIBS $LIBS"
-        AC_MSG_CHECKING([for pthread_join using $CC $PTHREAD_CFLAGS $PTHREAD_LIBS])
-        AC_LINK_IFELSE([AC_LANG_CALL([], [pthread_join])], [ax_pthread_ok=yes])
-        AC_MSG_RESULT([$ax_pthread_ok])
-        if test "x$ax_pthread_ok" = "xno"; then
-                PTHREAD_LIBS=""
-                PTHREAD_CFLAGS=""
-        fi
-        CC="$ax_pthread_save_CC"
-        CFLAGS="$ax_pthread_save_CFLAGS"
-        LIBS="$ax_pthread_save_LIBS"
-fi
-
-# We must check for the threads library under a number of different
-# names; the ordering is very important because some systems
-# (e.g. DEC) have both -lpthread and -lpthreads, where one of the
-# libraries is broken (non-POSIX).
-
-# Create a list of thread flags to try. Items with a "," contain both
-# C compiler flags (before ",") and linker flags (after ","). Other items
-# starting with a "-" are C compiler flags, and remaining items are
-# library names, except for "none" which indicates that we try without
-# any flags at all, and "pthread-config" which is a program returning
-# the flags for the Pth emulation library.
-
-ax_pthread_flags="pthreads none -Kthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
-
-# The ordering *is* (sometimes) important.  Some notes on the
-# individual items follow:
-
-# pthreads: AIX (must check this before -lpthread)
-# none: in case threads are in libc; should be tried before -Kthread and
-#       other compiler flags to prevent continual compiler warnings
-# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
-# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads), Tru64
-#           (Note: HP C rejects this with "bad form for `-t' option")
-# -pthreads: Solaris/gcc (Note: HP C also rejects)
-# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
-#      doesn't hurt to check since this sometimes defines pthreads and
-#      -D_REENTRANT too), HP C (must be checked before -lpthread, which
-#      is present but should not be used directly; and before -mthreads,
-#      because the compiler interprets this as "-mt" + "-hreads")
-# -mthreads: Mingw32/gcc, Lynx/gcc
-# pthread: Linux, etcetera
-# --thread-safe: KAI C++
-# pthread-config: use pthread-config program (for GNU Pth library)
-
-case $host_os in
-
-        freebsd*)
-
-        # -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
-        # lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
-
-        ax_pthread_flags="-kthread lthread $ax_pthread_flags"
-        ;;
-
-        hpux*)
-
-        # From the cc(1) man page: "[-mt] Sets various -D flags to enable
-        # multi-threading and also sets -lpthread."
-
-        ax_pthread_flags="-mt -pthread pthread $ax_pthread_flags"
-        ;;
-
-        openedition*)
-
-        # IBM z/OS requires a feature-test macro to be defined in order to
-        # enable POSIX threads at all, so give the user a hint if this is
-        # not set. (We don't define these ourselves, as they can affect
-        # other portions of the system API in unpredictable ways.)
-
-        AC_EGREP_CPP([AX_PTHREAD_ZOS_MISSING],
-            [
-#            if !defined(_OPEN_THREADS) && !defined(_UNIX03_THREADS)
-             AX_PTHREAD_ZOS_MISSING
-#            endif
-            ],
-            [AC_MSG_WARN([IBM z/OS requires -D_OPEN_THREADS or -D_UNIX03_THREADS to enable pthreads support.])])
-        ;;
-
-        solaris*)
-
-        # On Solaris (at least, for some versions), libc contains stubbed
-        # (non-functional) versions of the pthreads routines, so link-based
-        # tests will erroneously succeed. (N.B.: The stubs are missing
-        # pthread_cleanup_push, or rather a function called by this macro,
-        # so we could check for that, but who knows whether they'll stub
-        # that too in a future libc.)  So we'll check first for the
-        # standard Solaris way of linking pthreads (-mt -lpthread).
-
-        ax_pthread_flags="-mt,-lpthread pthread $ax_pthread_flags"
-        ;;
-esac
-
-# Are we compiling with Clang?
-
-AC_CACHE_CHECK([whether $CC is Clang],
-    [ax_cv_PTHREAD_CLANG],
-    [ax_cv_PTHREAD_CLANG=no
-     # Note that Autoconf sets GCC=yes for Clang as well as GCC
-     if test "x$GCC" = "xyes"; then
-        AC_EGREP_CPP([AX_PTHREAD_CC_IS_CLANG],
-            [/* Note: Clang 2.7 lacks __clang_[a-z]+__ */
-#            if defined(__clang__) && defined(__llvm__)
-             AX_PTHREAD_CC_IS_CLANG
-#            endif
-            ],
-            [ax_cv_PTHREAD_CLANG=yes])
-     fi
-    ])
-ax_pthread_clang="$ax_cv_PTHREAD_CLANG"
-
-
-# GCC generally uses -pthread, or -pthreads on some platforms (e.g. SPARC)
-
-# Note that for GCC and Clang -pthread generally implies -lpthread,
-# except when -nostdlib is passed.
-# This is problematic using libtool to build C++ shared libraries with pthread:
-# [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=25460
-# [2] https://bugzilla.redhat.com/show_bug.cgi?id=661333
-# [3] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=468555
-# To solve this, first try -pthread together with -lpthread for GCC
-
-AS_IF([test "x$GCC" = "xyes"],
-      [ax_pthread_flags="-pthread,-lpthread -pthread -pthreads $ax_pthread_flags"])
-
-# Clang takes -pthread (never supported any other flag), but we'll try with -lpthread first
-
-AS_IF([test "x$ax_pthread_clang" = "xyes"],
-      [ax_pthread_flags="-pthread,-lpthread -pthread"])
-
-
-# The presence of a feature test macro requesting re-entrant function
-# definitions is, on some systems, a strong hint that pthreads support is
-# correctly enabled
-
-case $host_os in
-        darwin* | hpux* | linux* | osf* | solaris*)
-        ax_pthread_check_macro="_REENTRANT"
-        ;;
-
-        aix*)
-        ax_pthread_check_macro="_THREAD_SAFE"
-        ;;
-
-        *)
-        ax_pthread_check_macro="--"
-        ;;
-esac
-AS_IF([test "x$ax_pthread_check_macro" = "x--"],
-      [ax_pthread_check_cond=0],
-      [ax_pthread_check_cond="!defined($ax_pthread_check_macro)"])
-
-
-if test "x$ax_pthread_ok" = "xno"; then
-for ax_pthread_try_flag in $ax_pthread_flags; do
-
-        case $ax_pthread_try_flag in
-                none)
-                AC_MSG_CHECKING([whether pthreads work without any flags])
-                ;;
-
-                *,*)
-                PTHREAD_CFLAGS=`echo $ax_pthread_try_flag | sed "s/^\(.*\),\(.*\)$/\1/"`
-                PTHREAD_LIBS=`echo $ax_pthread_try_flag | sed "s/^\(.*\),\(.*\)$/\2/"`
-                AC_MSG_CHECKING([whether pthreads work with "$PTHREAD_CFLAGS" and "$PTHREAD_LIBS"])
-                ;;
-
-                -*)
-                AC_MSG_CHECKING([whether pthreads work with $ax_pthread_try_flag])
-                PTHREAD_CFLAGS="$ax_pthread_try_flag"
-                ;;
-
-                pthread-config)
-                AC_CHECK_PROG([ax_pthread_config], [pthread-config], [yes], [no])
-                AS_IF([test "x$ax_pthread_config" = "xno"], [continue])
-                PTHREAD_CFLAGS="`pthread-config --cflags`"
-                PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
-                ;;
-
-                *)
-                AC_MSG_CHECKING([for the pthreads library -l$ax_pthread_try_flag])
-                PTHREAD_LIBS="-l$ax_pthread_try_flag"
-                ;;
-        esac
-
-        ax_pthread_save_CFLAGS="$CFLAGS"
-        ax_pthread_save_LIBS="$LIBS"
-        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
-        LIBS="$PTHREAD_LIBS $LIBS"
-
-        # Check for various functions.  We must include pthread.h,
-        # since some functions may be macros.  (On the Sequent, we
-        # need a special flag -Kthread to make this header compile.)
-        # We check for pthread_join because it is in -lpthread on IRIX
-        # while pthread_create is in libc.  We check for pthread_attr_init
-        # due to DEC craziness with -lpthreads.  We check for
-        # pthread_cleanup_push because it is one of the few pthread
-        # functions on Solaris that doesn't have a non-functional libc stub.
-        # We try pthread_create on general principles.
-
-        AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>
-#                       if $ax_pthread_check_cond
-#                        error "$ax_pthread_check_macro must be defined"
-#                       endif
-                        static void *some_global = NULL;
-                        static void routine(void *a)
-                          {
-                             /* To avoid any unused-parameter or
-                                unused-but-set-parameter warning.  */
-                             some_global = a;
-                          }
-                        static void *start_routine(void *a) { return a; }],
-                       [pthread_t th; pthread_attr_t attr;
-                        pthread_create(&th, 0, start_routine, 0);
-                        pthread_join(th, 0);
-                        pthread_attr_init(&attr);
-                        pthread_cleanup_push(routine, 0);
-                        pthread_cleanup_pop(0) /* ; */])],
-            [ax_pthread_ok=yes],
-            [])
-
-        CFLAGS="$ax_pthread_save_CFLAGS"
-        LIBS="$ax_pthread_save_LIBS"
-
-        AC_MSG_RESULT([$ax_pthread_ok])
-        AS_IF([test "x$ax_pthread_ok" = "xyes"], [break])
-
-        PTHREAD_LIBS=""
-        PTHREAD_CFLAGS=""
-done
-fi
-
-
-# Clang needs special handling, because older versions handle the -pthread
-# option in a rather... idiosyncratic way
-
-if test "x$ax_pthread_clang" = "xyes"; then
-
-        # Clang takes -pthread; it has never supported any other flag
-
-        # (Note 1: This will need to be revisited if a system that Clang
-        # supports has POSIX threads in a separate library.  This tends not
-        # to be the way of modern systems, but it's conceivable.)
-
-        # (Note 2: On some systems, notably Darwin, -pthread is not needed
-        # to get POSIX threads support; the API is always present and
-        # active.  We could reasonably leave PTHREAD_CFLAGS empty.  But
-        # -pthread does define _REENTRANT, and while the Darwin headers
-        # ignore this macro, third-party headers might not.)
-
-        # However, older versions of Clang make a point of warning the user
-        # that, in an invocation where only linking and no compilation is
-        # taking place, the -pthread option has no effect ("argument unused
-        # during compilation").  They expect -pthread to be passed in only
-        # when source code is being compiled.
-        #
-        # Problem is, this is at odds with the way Automake and most other
-        # C build frameworks function, which is that the same flags used in
-        # compilation (CFLAGS) are also used in linking.  Many systems
-        # supported by AX_PTHREAD require exactly this for POSIX threads
-        # support, and in fact it is often not straightforward to specify a
-        # flag that is used only in the compilation phase and not in
-        # linking.  Such a scenario is extremely rare in practice.
-        #
-        # Even though use of the -pthread flag in linking would only print
-        # a warning, this can be a nuisance for well-run software projects
-        # that build with -Werror.  So if the active version of Clang has
-        # this misfeature, we search for an option to squash it.
-
-        AC_CACHE_CHECK([whether Clang needs flag to prevent "argument unused" warning when linking with -pthread],
-            [ax_cv_PTHREAD_CLANG_NO_WARN_FLAG],
-            [ax_cv_PTHREAD_CLANG_NO_WARN_FLAG=unknown
-             # Create an alternate version of $ac_link that compiles and
-             # links in two steps (.c -> .o, .o -> exe) instead of one
-             # (.c -> exe), because the warning occurs only in the second
-             # step
-             ax_pthread_save_ac_link="$ac_link"
-             ax_pthread_sed='s/conftest\.\$ac_ext/conftest.$ac_objext/g'
-             ax_pthread_link_step=`AS_ECHO(["$ac_link"]) | sed "$ax_pthread_sed"`
-             ax_pthread_2step_ac_link="($ac_compile) && (echo ==== >&5) && ($ax_pthread_link_step)"
-             ax_pthread_save_CFLAGS="$CFLAGS"
-             for ax_pthread_try in '' -Qunused-arguments -Wno-unused-command-line-argument unknown; do
-                AS_IF([test "x$ax_pthread_try" = "xunknown"], [break])
-                CFLAGS="-Werror -Wunknown-warning-option $ax_pthread_try -pthread $ax_pthread_save_CFLAGS"
-                ac_link="$ax_pthread_save_ac_link"
-                AC_LINK_IFELSE([AC_LANG_SOURCE([[int main(void){return 0;}]])],
-                    [ac_link="$ax_pthread_2step_ac_link"
-                     AC_LINK_IFELSE([AC_LANG_SOURCE([[int main(void){return 0;}]])],
-                         [break])
-                    ])
-             done
-             ac_link="$ax_pthread_save_ac_link"
-             CFLAGS="$ax_pthread_save_CFLAGS"
-             AS_IF([test "x$ax_pthread_try" = "x"], [ax_pthread_try=no])
-             ax_cv_PTHREAD_CLANG_NO_WARN_FLAG="$ax_pthread_try"
-            ])
-
-        case "$ax_cv_PTHREAD_CLANG_NO_WARN_FLAG" in
-                no | unknown) ;;
-                *) PTHREAD_CFLAGS="$ax_cv_PTHREAD_CLANG_NO_WARN_FLAG $PTHREAD_CFLAGS" ;;
-        esac
-
-fi # $ax_pthread_clang = yes
-
-
-
-# Various other checks:
-if test "x$ax_pthread_ok" = "xyes"; then
-        ax_pthread_save_CFLAGS="$CFLAGS"
-        ax_pthread_save_LIBS="$LIBS"
-        CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
-        LIBS="$PTHREAD_LIBS $LIBS"
-
-        # Detect AIX lossage: JOINABLE attribute is called UNDETACHED.
-        AC_CACHE_CHECK([for joinable pthread attribute],
-            [ax_cv_PTHREAD_JOINABLE_ATTR],
-            [ax_cv_PTHREAD_JOINABLE_ATTR=unknown
-             for ax_pthread_attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
-                 AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <pthread.h>],
-                                                 [int attr = $ax_pthread_attr; return attr /* ; */])],
-                                [ax_cv_PTHREAD_JOINABLE_ATTR=$ax_pthread_attr; break],
-                                [])
-             done
-            ])
-        AS_IF([test "x$ax_cv_PTHREAD_JOINABLE_ATTR" != "xunknown" && \
-               test "x$ax_cv_PTHREAD_JOINABLE_ATTR" != "xPTHREAD_CREATE_JOINABLE" && \
-               test "x$ax_pthread_joinable_attr_defined" != "xyes"],
-              [AC_DEFINE_UNQUOTED([PTHREAD_CREATE_JOINABLE],
-                                  [$ax_cv_PTHREAD_JOINABLE_ATTR],
-                                  [Define to necessary symbol if this constant
-                                   uses a non-standard name on your system.])
-               ax_pthread_joinable_attr_defined=yes
-              ])
-
-        AC_CACHE_CHECK([whether more special flags are required for pthreads],
-            [ax_cv_PTHREAD_SPECIAL_FLAGS],
-            [ax_cv_PTHREAD_SPECIAL_FLAGS=no
-             case $host_os in
-             solaris*)
-             ax_cv_PTHREAD_SPECIAL_FLAGS="-D_POSIX_PTHREAD_SEMANTICS"
-             ;;
-             esac
-            ])
-        AS_IF([test "x$ax_cv_PTHREAD_SPECIAL_FLAGS" != "xno" && \
-               test "x$ax_pthread_special_flags_added" != "xyes"],
-              [PTHREAD_CFLAGS="$ax_cv_PTHREAD_SPECIAL_FLAGS $PTHREAD_CFLAGS"
-               ax_pthread_special_flags_added=yes])
-
-        AC_CACHE_CHECK([for PTHREAD_PRIO_INHERIT],
-            [ax_cv_PTHREAD_PRIO_INHERIT],
-            [AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <pthread.h>]],
-                                             [[int i = PTHREAD_PRIO_INHERIT;
-                                               return i;]])],
-                            [ax_cv_PTHREAD_PRIO_INHERIT=yes],
-                            [ax_cv_PTHREAD_PRIO_INHERIT=no])
-            ])
-        AS_IF([test "x$ax_cv_PTHREAD_PRIO_INHERIT" = "xyes" && \
-               test "x$ax_pthread_prio_inherit_defined" != "xyes"],
-              [AC_DEFINE([HAVE_PTHREAD_PRIO_INHERIT], [1], [Have PTHREAD_PRIO_INHERIT.])
-               ax_pthread_prio_inherit_defined=yes
-              ])
-
-        CFLAGS="$ax_pthread_save_CFLAGS"
-        LIBS="$ax_pthread_save_LIBS"
-
-        # More AIX lossage: compile with *_r variant
-        if test "x$GCC" != "xyes"; then
-            case $host_os in
-                aix*)
-                AS_CASE(["x/$CC"],
-                    [x*/c89|x*/c89_128|x*/c99|x*/c99_128|x*/cc|x*/cc128|x*/xlc|x*/xlc_v6|x*/xlc128|x*/xlc128_v6],
-                    [#handle absolute path differently from PATH based program lookup
-                     AS_CASE(["x$CC"],
-                         [x/*],
-                         [
-			   AS_IF([AS_EXECUTABLE_P([${CC}_r])],[PTHREAD_CC="${CC}_r"])
-			   AS_IF([test "x${CXX}" != "x"], [AS_IF([AS_EXECUTABLE_P([${CXX}_r])],[PTHREAD_CXX="${CXX}_r"])])
-			 ],
-                         [
-			   AC_CHECK_PROGS([PTHREAD_CC],[${CC}_r],[$CC])
-			   AS_IF([test "x${CXX}" != "x"], [AC_CHECK_PROGS([PTHREAD_CXX],[${CXX}_r],[$CXX])])
-			 ]
-                     )
-                    ])
-                ;;
-            esac
-        fi
-fi
-
-test -n "$PTHREAD_CC" || PTHREAD_CC="$CC"
-test -n "$PTHREAD_CXX" || PTHREAD_CXX="$CXX"
-
-AC_SUBST([PTHREAD_LIBS])
-AC_SUBST([PTHREAD_CFLAGS])
-AC_SUBST([PTHREAD_CC])
-AC_SUBST([PTHREAD_CXX])
-
-# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
-if test "x$ax_pthread_ok" = "xyes"; then
-        ifelse([$1],,[AC_DEFINE([HAVE_PTHREAD],[1],[Define if you have POSIX threads libraries and header files.])],[$1])
-        :
-else
-        ax_pthread_ok=no
-        $2
-fi
-AC_LANG_POP
-])dnl AX_PTHREAD