build: update boost macros to latest upstream

Fixes: #16803

I opened an [upstream PR](https://github.com/autoconf-archive/autoconf-archive/pull/197) to improve the Boost error reporting, so pull the latest macros.

Github-Pull: #16870
Rebased-From: bb99c4e684bbd3053ecf7a789049b11b29260189

6 files changed, 225 insertions, 203 deletions

diff --git a/build-aux/m4/ax_boost_base.m4 b/build-aux/m4/ax_boost_base.m4
index 650c94fa64..16fa69b41f 100644
--- a/build-aux/m4/ax_boost_base.m4
+++ b/build-aux/m4/ax_boost_base.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#       http://www.gnu.org/software/autoconf-archive/ax_boost_base.html
+#      https://www.gnu.org/software/autoconf-archive/ax_boost_base.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -33,7 +33,15 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 27
+#serial 47
+
+# example boost program (need to pass version)
+m4_define([_AX_BOOST_BASE_PROGRAM],
+          [AC_LANG_PROGRAM([[
+#include <boost/version.hpp>
+]],[[
+(void) ((void)sizeof(char[1 - 2*!!((BOOST_VERSION) < ($1))]));
+]])])
 
 AC_DEFUN([AX_BOOST_BASE],
 [
@@ -44,110 +52,122 @@ AC_ARG_WITH([boost],
      or disable it (ARG=no)
      @<:@ARG=yes@:>@ ])],
     [
-    if test "$withval" = "no"; then
-        want_boost="no"
-    elif test "$withval" = "yes"; then
-        want_boost="yes"
-        ac_boost_path=""
-    else
-        want_boost="yes"
-        ac_boost_path="$withval"
-    fi
+     AS_CASE([$withval],
+       [no],[want_boost="no";_AX_BOOST_BASE_boost_path=""],
+       [yes],[want_boost="yes";_AX_BOOST_BASE_boost_path=""],
+       [want_boost="yes";_AX_BOOST_BASE_boost_path="$withval"])
     ],
     [want_boost="yes"])
 
 
 AC_ARG_WITH([boost-libdir],
-        AS_HELP_STRING([--with-boost-libdir=LIB_DIR],
-        [Force given directory for boost libraries. Note that this will override library path detection, so use this parameter only if default library detection fails and you know exactly where your boost libraries are located.]),
-        [
-        if test -d "$withval"
-        then
-                ac_boost_lib_path="$withval"
-        else
-                AC_MSG_ERROR(--with-boost-libdir expected directory name)
-        fi
-        ],
-        [ac_boost_lib_path=""]
-)
+  [AS_HELP_STRING([--with-boost-libdir=LIB_DIR],
+    [Force given directory for boost libraries.
+     Note that this will override library path detection,
+     so use this parameter only if default library detection fails
+     and you know exactly where your boost libraries are located.])],
+  [
+   AS_IF([test -d "$withval"],
+         [_AX_BOOST_BASE_boost_lib_path="$withval"],
+    [AC_MSG_ERROR([--with-boost-libdir expected directory name])])
+  ],
+  [_AX_BOOST_BASE_boost_lib_path=""])
 
-if test "x$want_boost" = "xyes"; then
-    boost_lib_version_req=ifelse([$1], ,1.20.0,$1)
-    boost_lib_version_req_shorten=`expr $boost_lib_version_req : '\([[0-9]]*\.[[0-9]]*\)'`
-    boost_lib_version_req_major=`expr $boost_lib_version_req : '\([[0-9]]*\)'`
-    boost_lib_version_req_minor=`expr $boost_lib_version_req : '[[0-9]]*\.\([[0-9]]*\)'`
-    boost_lib_version_req_sub_minor=`expr $boost_lib_version_req : '[[0-9]]*\.[[0-9]]*\.\([[0-9]]*\)'`
-    if test "x$boost_lib_version_req_sub_minor" = "x" ; then
-        boost_lib_version_req_sub_minor="0"
-        fi
-    WANT_BOOST_VERSION=`expr $boost_lib_version_req_major \* 100000 \+  $boost_lib_version_req_minor \* 100 \+ $boost_lib_version_req_sub_minor`
-    AC_MSG_CHECKING(for boostlib >= $boost_lib_version_req)
+BOOST_LDFLAGS=""
+BOOST_CPPFLAGS=""
+AS_IF([test "x$want_boost" = "xyes"],
+      [_AX_BOOST_BASE_RUNDETECT([$1],[$2],[$3])])
+AC_SUBST(BOOST_CPPFLAGS)
+AC_SUBST(BOOST_LDFLAGS)
+])
+
+
+# convert a version string in $2 to numeric and affect to polymorphic var $1
+AC_DEFUN([_AX_BOOST_BASE_TONUMERICVERSION],[
+  AS_IF([test "x$2" = "x"],[_AX_BOOST_BASE_TONUMERICVERSION_req="1.20.0"],[_AX_BOOST_BASE_TONUMERICVERSION_req="$2"])
+  _AX_BOOST_BASE_TONUMERICVERSION_req_shorten=`expr $_AX_BOOST_BASE_TONUMERICVERSION_req : '\([[0-9]]*\.[[0-9]]*\)'`
+  _AX_BOOST_BASE_TONUMERICVERSION_req_major=`expr $_AX_BOOST_BASE_TONUMERICVERSION_req : '\([[0-9]]*\)'`
+  AS_IF([test "x$_AX_BOOST_BASE_TONUMERICVERSION_req_major" = "x"],
+        [AC_MSG_ERROR([You should at least specify libboost major version])])
+  _AX_BOOST_BASE_TONUMERICVERSION_req_minor=`expr $_AX_BOOST_BASE_TONUMERICVERSION_req : '[[0-9]]*\.\([[0-9]]*\)'`
+  AS_IF([test "x$_AX_BOOST_BASE_TONUMERICVERSION_req_minor" = "x"],
+        [_AX_BOOST_BASE_TONUMERICVERSION_req_minor="0"])
+  _AX_BOOST_BASE_TONUMERICVERSION_req_sub_minor=`expr $_AX_BOOST_BASE_TONUMERICVERSION_req : '[[0-9]]*\.[[0-9]]*\.\([[0-9]]*\)'`
+  AS_IF([test "X$_AX_BOOST_BASE_TONUMERICVERSION_req_sub_minor" = "X"],
+        [_AX_BOOST_BASE_TONUMERICVERSION_req_sub_minor="0"])
+  _AX_BOOST_BASE_TONUMERICVERSION_RET=`expr $_AX_BOOST_BASE_TONUMERICVERSION_req_major \* 100000 \+  $_AX_BOOST_BASE_TONUMERICVERSION_req_minor \* 100 \+ $_AX_BOOST_BASE_TONUMERICVERSION_req_sub_minor`
+  AS_VAR_SET($1,$_AX_BOOST_BASE_TONUMERICVERSION_RET)
+])
+
+dnl Run the detection of boost should be run only if $want_boost
+AC_DEFUN([_AX_BOOST_BASE_RUNDETECT],[
+    _AX_BOOST_BASE_TONUMERICVERSION(WANT_BOOST_VERSION,[$1])
     succeeded=no
 
+
+    AC_REQUIRE([AC_CANONICAL_HOST])
     dnl On 64-bit systems check for system libraries in both lib64 and lib.
     dnl The former is specified by FHS, but e.g. Debian does not adhere to
     dnl this (as it rises problems for generic multi-arch support).
     dnl The last entry in the list is chosen by default when no libraries
     dnl are found, e.g. when only header-only libraries are installed!
-    libsubdirs="lib"
-    ax_arch=`uname -m`
-    case $ax_arch in
-      x86_64)
-        libsubdirs="lib64 libx32 lib lib64"
-        ;;
-      ppc64|s390x|sparc64|aarch64|ppc64le)
-        libsubdirs="lib64 lib lib64"
-        ;;
-    esac
+    AS_CASE([${host_cpu}],
+      [x86_64],[libsubdirs="lib64 libx32 lib lib64"],
+      [mips*64*],[libsubdirs="lib64 lib32 lib lib64"],
+      [ppc64|powerpc64|s390x|sparc64|aarch64|ppc64le|powerpc64le|riscv64],[libsubdirs="lib64 lib lib64"],
+      [libsubdirs="lib"]
+    )
 
     dnl allow for real multi-arch paths e.g. /usr/lib/x86_64-linux-gnu. Give
     dnl them priority over the other paths since, if libs are found there, they
     dnl are almost assuredly the ones desired.
-    AC_REQUIRE([AC_CANONICAL_HOST])
-    libsubdirs="lib/${host_cpu}-${host_os} $libsubdirs"
-
-    case ${host_cpu} in
-      i?86)
-        libsubdirs="lib/i386-${host_os} $libsubdirs"
-        ;;
-    esac
-
-    dnl some arches may advertise a cpu type that doesn't line up with their
-    dnl prefix's cpu type. For example, uname may report armv7l while libs are
-    dnl installed to /usr/lib/arm-linux-gnueabihf. Try getting the compiler's
-    dnl value for an extra chance of finding the correct path.
-    libsubdirs="lib/`$CXX -dumpmachine 2>/dev/null` $libsubdirs"
+    AS_CASE([${host_cpu}],
+      [i?86],[multiarch_libsubdir="lib/i386-${host_os}"],
+      [multiarch_libsubdir="lib/${host_cpu}-${host_os}"]
+    )
 
     dnl first we check the system location for boost libraries
     dnl this location ist chosen if boost libraries are installed with the --layout=system option
     dnl or if you install boost with RPM
-    if test "$ac_boost_path" != ""; then
-        BOOST_CPPFLAGS="-I$ac_boost_path/include"
-        for ac_boost_path_tmp in $libsubdirs; do
-                if test -d "$ac_boost_path"/"$ac_boost_path_tmp" ; then
-                        BOOST_LDFLAGS="-L$ac_boost_path/$ac_boost_path_tmp"
-                        break
-                fi
-        done
-    elif test "$cross_compiling" != yes; then
-        for ac_boost_path_tmp in /usr /usr/local /opt /opt/local ; do
-            if test -d "$ac_boost_path_tmp/include/boost" && test -r "$ac_boost_path_tmp/include/boost"; then
-                for libsubdir in $libsubdirs ; do
-                    if ls "$ac_boost_path_tmp/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
+    AS_IF([test "x$_AX_BOOST_BASE_boost_path" != "x"],[
+        AC_MSG_CHECKING([for boostlib >= $1 ($WANT_BOOST_VERSION) includes in "$_AX_BOOST_BASE_boost_path/include"])
+         AS_IF([test -d "$_AX_BOOST_BASE_boost_path/include" && test -r "$_AX_BOOST_BASE_boost_path/include"],[
+           AC_MSG_RESULT([yes])
+           BOOST_CPPFLAGS="-I$_AX_BOOST_BASE_boost_path/include"
+           for _AX_BOOST_BASE_boost_path_tmp in $multiarch_libsubdir $libsubdirs; do
+                AC_MSG_CHECKING([for boostlib >= $1 ($WANT_BOOST_VERSION) lib path in "$_AX_BOOST_BASE_boost_path/$_AX_BOOST_BASE_boost_path_tmp"])
+                AS_IF([test -d "$_AX_BOOST_BASE_boost_path/$_AX_BOOST_BASE_boost_path_tmp" && test -r "$_AX_BOOST_BASE_boost_path/$_AX_BOOST_BASE_boost_path_tmp" ],[
+                        AC_MSG_RESULT([yes])
+                        BOOST_LDFLAGS="-L$_AX_BOOST_BASE_boost_path/$_AX_BOOST_BASE_boost_path_tmp";
+                        break;
+                ],
+      [AC_MSG_RESULT([no])])
+           done],[
+      AC_MSG_RESULT([no])])
+    ],[
+        if test X"$cross_compiling" = Xyes; then
+            search_libsubdirs=$multiarch_libsubdir
+        else
+            search_libsubdirs="$multiarch_libsubdir $libsubdirs"
+        fi
+        for _AX_BOOST_BASE_boost_path_tmp in /usr /usr/local /opt /opt/local ; do
+            if test -d "$_AX_BOOST_BASE_boost_path_tmp/include/boost" && test -r "$_AX_BOOST_BASE_boost_path_tmp/include/boost" ; then
+                for libsubdir in $search_libsubdirs ; do
+                    if ls "$_AX_BOOST_BASE_boost_path_tmp/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
                 done
-                BOOST_LDFLAGS="-L$ac_boost_path_tmp/$libsubdir"
-                BOOST_CPPFLAGS="-I$ac_boost_path_tmp/include"
+                BOOST_LDFLAGS="-L$_AX_BOOST_BASE_boost_path_tmp/$libsubdir"
+                BOOST_CPPFLAGS="-I$_AX_BOOST_BASE_boost_path_tmp/include"
                 break;
             fi
         done
-    fi
+    ])
 
     dnl overwrite ld flags if we have required special directory with
     dnl --with-boost-libdir parameter
-    if test "$ac_boost_lib_path" != ""; then
-       BOOST_LDFLAGS="-L$ac_boost_lib_path"
-    fi
+    AS_IF([test "x$_AX_BOOST_BASE_boost_lib_path" != "x"],
+          [BOOST_LDFLAGS="-L$_AX_BOOST_BASE_boost_lib_path"])
 
+    AC_MSG_CHECKING([for boostlib >= $1 ($WANT_BOOST_VERSION)])
     CPPFLAGS_SAVED="$CPPFLAGS"
     CPPFLAGS="$CPPFLAGS $BOOST_CPPFLAGS"
     export CPPFLAGS
@@ -158,15 +178,7 @@ if test "x$want_boost" = "xyes"; then
 
     AC_REQUIRE([AC_PROG_CXX])
     AC_LANG_PUSH(C++)
-        AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-    @%:@include <boost/version.hpp>
-    ]], [[
-    #if BOOST_VERSION >= $WANT_BOOST_VERSION
-    // Everything is okay
-    #else
-    #  error Boost version is too old
-    #endif
-    ]])],[
+        AC_COMPILE_IFELSE([_AX_BOOST_BASE_PROGRAM($WANT_BOOST_VERSION)],[
         AC_MSG_RESULT(yes)
     succeeded=yes
     found_system=yes
@@ -178,40 +190,50 @@ if test "x$want_boost" = "xyes"; then
 
     dnl if we found no boost with system layout we search for boost libraries
     dnl built and installed without the --layout=system option or for a staged(not installed) version
-    if test "x$succeeded" != "xyes"; then
+    if test "x$succeeded" != "xyes" ; then
         CPPFLAGS="$CPPFLAGS_SAVED"
         LDFLAGS="$LDFLAGS_SAVED"
         BOOST_CPPFLAGS=
-        BOOST_LDFLAGS=
+        if test -z "$_AX_BOOST_BASE_boost_lib_path" ; then
+            BOOST_LDFLAGS=
+        fi
         _version=0
-        if test "$ac_boost_path" != ""; then
-            if test -d "$ac_boost_path" && test -r "$ac_boost_path"; then
-                for i in `ls -d $ac_boost_path/include/boost-* 2>/dev/null`; do
-                    _version_tmp=`echo $i | sed "s#$ac_boost_path##" | sed 's/\/include\/boost-//' | sed 's/_/./'`
+        if test -n "$_AX_BOOST_BASE_boost_path" ; then
+            if test -d "$_AX_BOOST_BASE_boost_path" && test -r "$_AX_BOOST_BASE_boost_path"; then
+                for i in `ls -d $_AX_BOOST_BASE_boost_path/include/boost-* 2>/dev/null`; do
+                    _version_tmp=`echo $i | sed "s#$_AX_BOOST_BASE_boost_path##" | sed 's/\/include\/boost-//' | sed 's/_/./'`
                     V_CHECK=`expr $_version_tmp \> $_version`
-                    if test "$V_CHECK" = "1" ; then
+                    if test "x$V_CHECK" = "x1" ; then
                         _version=$_version_tmp
                     fi
                     VERSION_UNDERSCORE=`echo $_version | sed 's/\./_/'`
-                    BOOST_CPPFLAGS="-I$ac_boost_path/include/boost-$VERSION_UNDERSCORE"
+                    BOOST_CPPFLAGS="-I$_AX_BOOST_BASE_boost_path/include/boost-$VERSION_UNDERSCORE"
                 done
                 dnl if nothing found search for layout used in Windows distributions
                 if test -z "$BOOST_CPPFLAGS"; then
-                    if test -d "$ac_boost_path/boost" && test -r "$ac_boost_path/boost"; then
-                        BOOST_CPPFLAGS="-I$ac_boost_path"
+                    if test -d "$_AX_BOOST_BASE_boost_path/boost" && test -r "$_AX_BOOST_BASE_boost_path/boost"; then
+                        BOOST_CPPFLAGS="-I$_AX_BOOST_BASE_boost_path"
                     fi
                 fi
+                dnl if we found something and BOOST_LDFLAGS was unset before
+                dnl (because "$_AX_BOOST_BASE_boost_lib_path" = ""), set it here.
+                if test -n "$BOOST_CPPFLAGS" && test -z "$BOOST_LDFLAGS"; then
+                    for libsubdir in $libsubdirs ; do
+                        if ls "$_AX_BOOST_BASE_boost_path/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
+                    done
+                    BOOST_LDFLAGS="-L$_AX_BOOST_BASE_boost_path/$libsubdir"
+                fi
             fi
         else
-            if test "$cross_compiling" != yes; then
-                for ac_boost_path in /usr /usr/local /opt /opt/local ; do
-                    if test -d "$ac_boost_path" && test -r "$ac_boost_path"; then
-                        for i in `ls -d $ac_boost_path/include/boost-* 2>/dev/null`; do
-                            _version_tmp=`echo $i | sed "s#$ac_boost_path##" | sed 's/\/include\/boost-//' | sed 's/_/./'`
+            if test "x$cross_compiling" != "xyes" ; then
+                for _AX_BOOST_BASE_boost_path in /usr /usr/local /opt /opt/local ; do
+                    if test -d "$_AX_BOOST_BASE_boost_path" && test -r "$_AX_BOOST_BASE_boost_path" ; then
+                        for i in `ls -d $_AX_BOOST_BASE_boost_path/include/boost-* 2>/dev/null`; do
+                            _version_tmp=`echo $i | sed "s#$_AX_BOOST_BASE_boost_path##" | sed 's/\/include\/boost-//' | sed 's/_/./'`
                             V_CHECK=`expr $_version_tmp \> $_version`
-                            if test "$V_CHECK" = "1" ; then
+                            if test "x$V_CHECK" = "x1" ; then
                                 _version=$_version_tmp
-                                best_path=$ac_boost_path
+                                best_path=$_AX_BOOST_BASE_boost_path
                             fi
                         done
                     fi
@@ -219,7 +241,7 @@ if test "x$want_boost" = "xyes"; then
 
                 VERSION_UNDERSCORE=`echo $_version | sed 's/\./_/'`
                 BOOST_CPPFLAGS="-I$best_path/include/boost-$VERSION_UNDERSCORE"
-                if test "$ac_boost_lib_path" = ""; then
+                if test -z "$_AX_BOOST_BASE_boost_lib_path" ; then
                     for libsubdir in $libsubdirs ; do
                         if ls "$best_path/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
                     done
@@ -227,7 +249,7 @@ if test "x$want_boost" = "xyes"; then
                 fi
             fi
 
-            if test "x$BOOST_ROOT" != "x"; then
+            if test -n "$BOOST_ROOT" ; then
                 for libsubdir in $libsubdirs ; do
                     if ls "$BOOST_ROOT/stage/$libsubdir/libboost_"* >/dev/null 2>&1 ; then break; fi
                 done
@@ -236,7 +258,7 @@ if test "x$want_boost" = "xyes"; then
                     stage_version=`echo $version_dir | sed 's/boost_//' | sed 's/_/./g'`
                         stage_version_shorten=`expr $stage_version : '\([[0-9]]*\.[[0-9]]*\)'`
                     V_CHECK=`expr $stage_version_shorten \>\= $_version`
-                    if test "$V_CHECK" = "1" -a "$ac_boost_lib_path" = "" ; then
+                    if test "x$V_CHECK" = "x1" && test -z "$_AX_BOOST_BASE_boost_lib_path" ; then
                         AC_MSG_NOTICE(We will use a staged boost library from $BOOST_ROOT)
                         BOOST_CPPFLAGS="-I$BOOST_ROOT"
                         BOOST_LDFLAGS="-L$BOOST_ROOT/stage/$libsubdir"
@@ -251,15 +273,7 @@ if test "x$want_boost" = "xyes"; then
         export LDFLAGS
 
         AC_LANG_PUSH(C++)
-            AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
-        @%:@include <boost/version.hpp>
-        ]], [[
-        #if BOOST_VERSION >= $WANT_BOOST_VERSION
-        // Everything is okay
-        #else
-        #  error Boost version is too old
-        #endif
-        ]])],[
+            AC_COMPILE_IFELSE([_AX_BOOST_BASE_PROGRAM($WANT_BOOST_VERSION)],[
             AC_MSG_RESULT(yes)
         succeeded=yes
         found_system=yes
@@ -268,17 +282,15 @@ if test "x$want_boost" = "xyes"; then
         AC_LANG_POP([C++])
     fi
 
-    if test "$succeeded" != "yes" ; then
-        if test "$_version" = "0" ; then
-            AC_MSG_NOTICE([[We could not detect the boost libraries (version $boost_lib_version_req_shorten or higher). If you have a staged boost library (still not installed) please specify \$BOOST_ROOT in your environment and do not give a PATH to --with-boost option.  If you are sure you have boost installed, then check your version number looking in <boost/version.hpp>. See http://randspringer.de/boost for more documentation.]])
+    if test "x$succeeded" != "xyes" ; then
+        if test "x$_version" = "x0" ; then
+            AC_MSG_NOTICE([[We could not detect the boost libraries (version $1 or higher). If you have a staged boost library (still not installed) please specify \$BOOST_ROOT in your environment and do not give a PATH to --with-boost option.  If you are sure you have boost installed, then check your version number looking in <boost/version.hpp>. See http://randspringer.de/boost for more documentation.]])
         else
             AC_MSG_NOTICE([Your boost libraries seems to old (version $_version).])
         fi
         # execute ACTION-IF-NOT-FOUND (if present):
         ifelse([$3], , :, [$3])
     else
-        AC_SUBST(BOOST_CPPFLAGS)
-        AC_SUBST(BOOST_LDFLAGS)
         AC_DEFINE(HAVE_BOOST,,[define if the Boost library is available])
         # execute ACTION-IF-FOUND (if present):
         ifelse([$2], , :, [$2])
@@ -286,6 +298,5 @@ if test "x$want_boost" = "xyes"; then
 
     CPPFLAGS="$CPPFLAGS_SAVED"
     LDFLAGS="$LDFLAGS_SAVED"
-fi
 
 ])
diff --git a/build-aux/m4/ax_boost_chrono.m4 b/build-aux/m4/ax_boost_chrono.m4
index 6ea77b9b3e..4cd3b86041 100644
--- a/build-aux/m4/ax_boost_chrono.m4
+++ b/build-aux/m4/ax_boost_chrono.m4
@@ -29,7 +29,7 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 4
+#serial 5
 
 AC_DEFUN([AX_BOOST_CHRONO],
 [
@@ -105,7 +105,7 @@ AC_DEFUN([AX_BOOST_CHRONO],
 
             fi
             if test "x$ax_lib" = "x"; then
-                AC_MSG_ERROR(Could not find a version of the library!)
+                AC_MSG_ERROR(Could not find a version of the Boost::Chrono library!)
             fi
 			if test "x$link_chrono" = "xno"; then
 				AC_MSG_ERROR(Could not link against $ax_lib !)
diff --git a/build-aux/m4/ax_boost_filesystem.m4 b/build-aux/m4/ax_boost_filesystem.m4
index f5c9d56470..12f7bc5e2e 100644
--- a/build-aux/m4/ax_boost_filesystem.m4
+++ b/build-aux/m4/ax_boost_filesystem.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#    http://www.gnu.org/software/autoconf-archive/ax_boost_filesystem.html
+#   https://www.gnu.org/software/autoconf-archive/ax_boost_filesystem.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -31,7 +31,7 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 26
+#serial 28
 
 AC_DEFUN([AX_BOOST_FILESYSTEM],
 [
@@ -80,7 +80,6 @@ AC_DEFUN([AX_BOOST_FILESYSTEM],
 		if test "x$ax_cv_boost_filesystem" = "xyes"; then
 			AC_DEFINE(HAVE_BOOST_FILESYSTEM,,[define if the Boost::Filesystem library is available])
             BOOSTLIBDIR=`echo $BOOST_LDFLAGS | sed -e 's/@<:@^\/@:>@*//'`
-            ax_lib=
             if test "x$ax_boost_user_filesystem_lib" = "x"; then
                 for libextension in `ls -r $BOOSTLIBDIR/libboost_filesystem* 2>/dev/null | sed 's,.*/lib,,' | sed 's,\..*,,'` ; do
                      ax_lib=${libextension}
@@ -105,7 +104,7 @@ AC_DEFUN([AX_BOOST_FILESYSTEM],
 
             fi
             if test "x$ax_lib" = "x"; then
-                AC_MSG_ERROR(Could not find a version of the boost_filesystem library!)
+                AC_MSG_ERROR(Could not find a version of the Boost::Filesystem library!)
             fi
 			if test "x$link_filesystem" != "xyes"; then
 				AC_MSG_ERROR(Could not link against $ax_lib !)
diff --git a/build-aux/m4/ax_boost_system.m4 b/build-aux/m4/ax_boost_system.m4
index 1c05450cbe..323e2a676a 100644
--- a/build-aux/m4/ax_boost_system.m4
+++ b/build-aux/m4/ax_boost_system.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#      http://www.gnu.org/software/autoconf-archive/ax_boost_system.html
+#     https://www.gnu.org/software/autoconf-archive/ax_boost_system.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -31,7 +31,7 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 18
+#serial 20
 
 AC_DEFUN([AX_BOOST_SYSTEM],
 [
@@ -84,7 +84,6 @@ AC_DEFUN([AX_BOOST_SYSTEM],
 
 			LDFLAGS_SAVE=$LDFLAGS
             if test "x$ax_boost_user_system_lib" = "x"; then
-                ax_lib=
                 for libextension in `ls -r $BOOSTLIBDIR/libboost_system* 2>/dev/null | sed 's,.*/lib,,' | sed 's,\..*,,'` ; do
                      ax_lib=${libextension}
 				    AC_CHECK_LIB($ax_lib, exit,
@@ -109,7 +108,7 @@ AC_DEFUN([AX_BOOST_SYSTEM],
 
             fi
             if test "x$ax_lib" = "x"; then
-                AC_MSG_ERROR(Could not find a version of the boost_system library!)
+                AC_MSG_ERROR(Could not find a version of the Boost::System library!)
             fi
 			if test "x$link_system" = "xno"; then
 				AC_MSG_ERROR(Could not link against $ax_lib !)
diff --git a/build-aux/m4/ax_boost_thread.m4 b/build-aux/m4/ax_boost_thread.m4
index 9f0bd0b23c..e9dea43535 100644
--- a/build-aux/m4/ax_boost_thread.m4
+++ b/build-aux/m4/ax_boost_thread.m4
@@ -1,5 +1,5 @@
 # ===========================================================================
-#      http://www.gnu.org/software/autoconf-archive/ax_boost_thread.html
+#     https://www.gnu.org/software/autoconf-archive/ax_boost_thread.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -30,73 +30,75 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 27
+#serial 32
 
 AC_DEFUN([AX_BOOST_THREAD],
 [
-	AC_ARG_WITH([boost-thread],
-	AS_HELP_STRING([--with-boost-thread@<:@=special-lib@:>@],
-                   [use the Thread library from boost - it is possible to specify a certain library for the linker
-                        e.g. --with-boost-thread=boost_thread-gcc-mt ]),
+    AC_ARG_WITH([boost-thread],
+    AS_HELP_STRING([--with-boost-thread@<:@=special-lib@:>@],
+                   [use the Thread library from boost -
+                    it is possible to specify a certain library for the linker
+                    e.g. --with-boost-thread=boost_thread-gcc-mt ]),
         [
-        if test "$withval" = "no"; then
-			want_boost="no"
-        elif test "$withval" = "yes"; then
+        if test "$withval" = "yes"; then
             want_boost="yes"
             ax_boost_user_thread_lib=""
         else
-		    want_boost="yes"
-		ax_boost_user_thread_lib="$withval"
-		fi
+            want_boost="yes"
+            ax_boost_user_thread_lib="$withval"
+        fi
         ],
         [want_boost="yes"]
-	)
+    )
 
-	if test "x$want_boost" = "xyes"; then
+    if test "x$want_boost" = "xyes"; then
         AC_REQUIRE([AC_PROG_CC])
         AC_REQUIRE([AC_CANONICAL_BUILD])
-		CPPFLAGS_SAVED="$CPPFLAGS"
-		CPPFLAGS="$CPPFLAGS $BOOST_CPPFLAGS"
-		export CPPFLAGS
+        CPPFLAGS_SAVED="$CPPFLAGS"
+        CPPFLAGS="$CPPFLAGS $BOOST_CPPFLAGS"
+        export CPPFLAGS
 
-		LDFLAGS_SAVED="$LDFLAGS"
-		LDFLAGS="$LDFLAGS $BOOST_LDFLAGS"
-		export LDFLAGS
+        LDFLAGS_SAVED="$LDFLAGS"
+        LDFLAGS="$LDFLAGS $BOOST_LDFLAGS"
+        export LDFLAGS
 
         AC_CACHE_CHECK(whether the Boost::Thread library is available,
-					   ax_cv_boost_thread,
+                       ax_cv_boost_thread,
         [AC_LANG_PUSH([C++])
-			 CXXFLAGS_SAVE=$CXXFLAGS
+             CXXFLAGS_SAVE=$CXXFLAGS
 
-			 if test "x$host_os" = "xsolaris" ; then
-				 CXXFLAGS="-pthreads $CXXFLAGS"
-			 elif test "x$host_os" = "xmingw32" ; then
-				 CXXFLAGS="-mthreads $CXXFLAGS"
-			 else
-				CXXFLAGS="-pthread $CXXFLAGS"
-			 fi
-			 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[@%:@include <boost/thread/thread.hpp>]],
-                                   [[boost::thread_group thrds;
-                                   return 0;]])],
-                   ax_cv_boost_thread=yes, ax_cv_boost_thread=no)
-			 CXXFLAGS=$CXXFLAGS_SAVE
+             if test "x$host_os" = "xsolaris" ; then
+                 CXXFLAGS="-pthreads $CXXFLAGS"
+             elif test "x$host_os" = "xmingw32" ; then
+                 CXXFLAGS="-mthreads $CXXFLAGS"
+             else
+                CXXFLAGS="-pthread $CXXFLAGS"
+             fi
+             AC_COMPILE_IFELSE([
+                 AC_LANG_PROGRAM(
+                     [[@%:@include <boost/thread/thread.hpp>]],
+                     [[boost::thread_group thrds;
+                       return 0;]])],
+                 ax_cv_boost_thread=yes, ax_cv_boost_thread=no)
+             CXXFLAGS=$CXXFLAGS_SAVE
              AC_LANG_POP([C++])
-		])
-		if test "x$ax_cv_boost_thread" = "xyes"; then
+        ])
+        if test "x$ax_cv_boost_thread" = "xyes"; then
            if test "x$host_os" = "xsolaris" ; then
-			  BOOST_CPPFLAGS="-pthreads $BOOST_CPPFLAGS"
-		   elif test "x$host_os" = "xmingw32" ; then
-			  BOOST_CPPFLAGS="-mthreads $BOOST_CPPFLAGS"
-		   else
-			  BOOST_CPPFLAGS="-pthread $BOOST_CPPFLAGS"
-		   fi
+              BOOST_CPPFLAGS="-pthreads $BOOST_CPPFLAGS"
+           elif test "x$host_os" = "xmingw32" ; then
+              BOOST_CPPFLAGS="-mthreads $BOOST_CPPFLAGS"
+           else
+              BOOST_CPPFLAGS="-pthread $BOOST_CPPFLAGS"
+           fi
 
-			AC_SUBST(BOOST_CPPFLAGS)
+            AC_SUBST(BOOST_CPPFLAGS)
 
-			AC_DEFINE(HAVE_BOOST_THREAD,,[define if the Boost::Thread library is available])
+            AC_DEFINE(HAVE_BOOST_THREAD,,
+                      [define if the Boost::Thread library is available])
             BOOSTLIBDIR=`echo $BOOST_LDFLAGS | sed -e 's/@<:@^\/@:>@*//'`
 
-			LDFLAGS_SAVE=$LDFLAGS
+            LDFLAGS_SAVE=$LDFLAGS
                         case "x$host_os" in
                           *bsd* )
                                LDFLAGS="-pthread $LDFLAGS"
@@ -104,47 +106,58 @@ AC_DEFUN([AX_BOOST_THREAD],
                           ;;
                         esac
             if test "x$ax_boost_user_thread_lib" = "x"; then
-                ax_lib=
                 for libextension in `ls -r $BOOSTLIBDIR/libboost_thread* 2>/dev/null | sed 's,.*/lib,,' | sed 's,\..*,,'`; do
                      ax_lib=${libextension}
-				    AC_CHECK_LIB($ax_lib, exit,
-                                 [BOOST_THREAD_LIB="-l$ax_lib"; AC_SUBST(BOOST_THREAD_LIB) link_thread="yes"; break],
+                    AC_CHECK_LIB($ax_lib, exit,
+                                 [link_thread="yes"; break],
                                  [link_thread="no"])
-				done
+                done
                 if test "x$link_thread" != "xyes"; then
                 for libextension in `ls -r $BOOSTLIBDIR/boost_thread* 2>/dev/null | sed 's,.*/,,' | sed 's,\..*,,'`; do
                      ax_lib=${libextension}
-				    AC_CHECK_LIB($ax_lib, exit,
-                                 [BOOST_THREAD_LIB="-l$ax_lib"; AC_SUBST(BOOST_THREAD_LIB) link_thread="yes"; break],
+                    AC_CHECK_LIB($ax_lib, exit,
+                                 [link_thread="yes"; break],
                                  [link_thread="no"])
-				done
+                done
                 fi
 
             else
                for ax_lib in $ax_boost_user_thread_lib boost_thread-$ax_boost_user_thread_lib; do
-				      AC_CHECK_LIB($ax_lib, exit,
-                                   [BOOST_THREAD_LIB="-l$ax_lib"; AC_SUBST(BOOST_THREAD_LIB) link_thread="yes"; break],
+                      AC_CHECK_LIB($ax_lib, exit,
+                                   [link_thread="yes"; break],
                                    [link_thread="no"])
                   done
 
             fi
             if test "x$ax_lib" = "x"; then
-                AC_MSG_ERROR(Could not find a version of the boost_thread library!)
+                AC_MSG_ERROR(Could not find a version of the Boost::Thread library!)
             fi
-			if test "x$link_thread" = "xno"; then
-				AC_MSG_ERROR(Could not link against $ax_lib !)
-                        else
-                           case "x$host_os" in
-                              *bsd* )
-				BOOST_LDFLAGS="-pthread $BOOST_LDFLAGS"
-                              break;
-                              ;;
-                           esac
-
-			fi
-		fi
+            if test "x$link_thread" = "xno"; then
+                AC_MSG_ERROR(Could not link against $ax_lib !)
+            else
+                BOOST_THREAD_LIB="-l$ax_lib"
+                case "x$host_os" in
+                    *bsd* )
+                        BOOST_LDFLAGS="-pthread $BOOST_LDFLAGS"
+                        break;
+                        ;;
+                    xsolaris )
+                        BOOST_THREAD_LIB="$BOOST_THREAD_LIB -lpthread"
+                        break;
+                        ;;
+                    xmingw32 )
+                        break;
+                        ;;
+                    * )
+                        BOOST_THREAD_LIB="$BOOST_THREAD_LIB -lpthread"
+                        break;
+                        ;;
+                esac
+                AC_SUBST(BOOST_THREAD_LIB)
+            fi
+        fi
 
-		CPPFLAGS="$CPPFLAGS_SAVED"
-	LDFLAGS="$LDFLAGS_SAVED"
-	fi
+        CPPFLAGS="$CPPFLAGS_SAVED"
+        LDFLAGS="$LDFLAGS_SAVED"
+    fi
 ])
diff --git a/build-aux/m4/ax_boost_unit_test_framework.m4 b/build-aux/m4/ax_boost_unit_test_framework.m4
index 3d8e93e964..4cca32fcfd 100644
--- a/build-aux/m4/ax_boost_unit_test_framework.m4
+++ b/build-aux/m4/ax_boost_unit_test_framework.m4
@@ -29,7 +29,7 @@
 #   and this notice are preserved. This file is offered as-is, without any
 #   warranty.
 
-#serial 21
+#serial 22
 
 AC_DEFUN([AX_BOOST_UNIT_TEST_FRAMEWORK],
 [
@@ -124,7 +124,7 @@ AC_DEFUN([AX_BOOST_UNIT_TEST_FRAMEWORK],
                done
             fi
             if test "x$ax_lib" = "x"; then
-                AC_MSG_ERROR(Could not find a version of the library!)
+                AC_MSG_ERROR(Could not find a version of the Boost::Unit_Test_Framework library!)
             fi
 			if test "x$link_unit_test_framework" != "xyes"; then
 				AC_MSG_ERROR(Could not link against $ax_lib !)