2 files changed, 252 insertions, 110 deletions

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index e37201c..4ee5f77 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -155,6 +155,7 @@ jobs:
             PYTHON_EXEC_PREFIX=`$PYTHON3_BIN -c "import distutils.sysconfig; print(distutils.sysconfig.get_config_var('exec_prefix'))"`
             PYTHON_LIBS_PATH=$PYTHON_EXEC_PREFIX/lib
             PYTHON_FRAMEWORK_PATH=$PYTHON_EXEC_PREFIX/Python3
+            export PYTHON_CPPFLAGS="-I$PYTHON_EXEC_PREFIX/Headers"
             export PYTHON_LIBS="-L$PYTHON_LIBS_PATH -lpython$PYTHON_VER"
             export PYTHON_EXTRA_LDFLAGS="-Wl,-stack_size,1000000  -framework CoreFoundation $PYTHON_FRAMEWORK_PATH"
           fi
diff --git a/m4/ax_python_devel.m4 b/m4/ax_python_devel.m4
index 44dbd83..935056c 100644
--- a/m4/ax_python_devel.m4
+++ b/m4/ax_python_devel.m4
@@ -4,7 +4,7 @@
 #
 # SYNOPSIS
 #
-#   AX_PYTHON_DEVEL([version])
+#   AX_PYTHON_DEVEL([version[,optional]])
 #
 # DESCRIPTION
 #
@@ -23,6 +23,11 @@
 #   version number. Don't use "PYTHON_VERSION" for this: that environment
 #   variable is declared as precious and thus reserved for the end-user.
 #
+#   By default this will fail if it does not detect a development version of
+#   python.  If you want it to continue, set optional to true, like
+#   AX_PYTHON_DEVEL([], [true]).  The ax_python_devel_found variable will be
+#   "no" if it fails.
+#
 #   This macro should work for all versions of Python >= 2.1.0. As an end
 #   user, you can disable the check for the python version by setting the
 #   PYTHON_NOVERSIONCHECK environment variable to something else than the
@@ -67,10 +72,18 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 21
+#serial 37
 
 AU_ALIAS([AC_PYTHON_DEVEL], [AX_PYTHON_DEVEL])
 AC_DEFUN([AX_PYTHON_DEVEL],[
+        # Get whether it's optional
+        if test -z "$2"; then
+           ax_python_devel_optional=false
+        else
+           ax_python_devel_optional=$2
+        fi
+        ax_python_devel_found=yes
+
         #
         # Allow the use of a (user set) custom python version
         #
@@ -81,21 +94,26 @@ AC_DEFUN([AX_PYTHON_DEVEL],[
 
         AC_PATH_PROG([PYTHON],[python[$PYTHON_VERSION]])
         if test -z "$PYTHON"; then
-           AC_MSG_ERROR([Cannot find python$PYTHON_VERSION in your system path])
+           AC_MSG_WARN([Cannot find python$PYTHON_VERSION in your system path])
+           if ! $ax_python_devel_optional; then
+              AC_MSG_ERROR([Giving up, python development not available])
+           fi
+           ax_python_devel_found=no
            PYTHON_VERSION=""
         fi
 
-        #
-        # Check for a version of Python >= 2.1.0
-        #
-        AC_MSG_CHECKING([for a version of Python >= '2.1.0'])
-        ac_supports_python_ver=`$PYTHON -c "import sys; \
+        if test $ax_python_devel_found = yes; then
+           #
+           # Check for a version of Python >= 2.1.0
+           #
+           AC_MSG_CHECKING([for a version of Python >= '2.1.0'])
+           ac_supports_python_ver=`$PYTHON -c "import sys; \
                 ver = sys.version.split ()[[0]]; \
                 print (ver >= '2.1.0')"`
-        if test "$ac_supports_python_ver" != "True"; then
+           if test "$ac_supports_python_ver" != "True"; then
                 if test -z "$PYTHON_NOVERSIONCHECK"; then
                         AC_MSG_RESULT([no])
-                        AC_MSG_FAILURE([
+                        AC_MSG_WARN([
 This version of the AC@&t@_PYTHON_DEVEL macro
 doesn't work properly with versions of Python before
 2.1.0. You may need to re-run configure, setting the
@@ -104,58 +122,119 @@ PYTHON_EXTRA_LIBS and PYTHON_EXTRA_LDFLAGS by hand.
 Moreover, to disable this check, set PYTHON_NOVERSIONCHECK
 to something else than an empty string.
 ])
+                        if ! $ax_python_devel_optional; then
+                           AC_MSG_FAILURE([Giving up])
+                        fi
+                        ax_python_devel_found=no
+                        PYTHON_VERSION=""
                 else
                         AC_MSG_RESULT([skip at user request])
                 fi
-        else
+           else
                 AC_MSG_RESULT([yes])
+           fi
         fi
 
-        #
-        # if the macro parameter ``version'' is set, honour it
-        #
-        if test -n "$1"; then
+        if test $ax_python_devel_found = yes; then
+           #
+           # If the macro parameter ``version'' is set, honour it.
+           # A Python shim class, VPy, is used to implement correct version comparisons via
+           # string expressions, since e.g. a naive textual ">= 2.7.3" won't work for
+           # Python 2.7.10 (the ".1" being evaluated as less than ".3").
+           #
+           if test -n "$1"; then
                 AC_MSG_CHECKING([for a version of Python $1])
-                ac_supports_python_ver=`$PYTHON -c "import sys; \
-                        ver = sys.version.split ()[[0]]; \
+                cat << EOF > ax_python_devel_vpy.py
+class VPy:
+    def vtup(self, s):
+        return tuple(map(int, s.strip().replace("rc", ".").split(".")))
+    def __init__(self):
+        import sys
+        self.vpy = tuple(sys.version_info)[[:3]]
+    def __eq__(self, s):
+        return self.vpy == self.vtup(s)
+    def __ne__(self, s):
+        return self.vpy != self.vtup(s)
+    def __lt__(self, s):
+        return self.vpy < self.vtup(s)
+    def __gt__(self, s):
+        return self.vpy > self.vtup(s)
+    def __le__(self, s):
+        return self.vpy <= self.vtup(s)
+    def __ge__(self, s):
+        return self.vpy >= self.vtup(s)
+EOF
+                ac_supports_python_ver=`$PYTHON -c "import ax_python_devel_vpy; \
+                        ver = ax_python_devel_vpy.VPy(); \
                         print (ver $1)"`
+                rm -rf ax_python_devel_vpy*.py* __pycache__/ax_python_devel_vpy*.py*
                 if test "$ac_supports_python_ver" = "True"; then
-                   AC_MSG_RESULT([yes])
+                        AC_MSG_RESULT([yes])
                 else
                         AC_MSG_RESULT([no])
-                        AC_MSG_ERROR([this package requires Python $1.
+                        AC_MSG_WARN([this package requires Python $1.
 If you have it installed, but it isn't the default Python
 interpreter in your system path, please pass the PYTHON_VERSION
 variable to configure. See ``configure --help'' for reference.
 ])
+                        if ! $ax_python_devel_optional; then
+                           AC_MSG_ERROR([Giving up])
+                        fi
+                        ax_python_devel_found=no
                         PYTHON_VERSION=""
                 fi
+           fi
         fi
 
-        #
-        # Check if you have distutils, else fail
-        #
-        AC_MSG_CHECKING([for the distutils Python package])
-        ac_distutils_result=`$PYTHON -c "import distutils" 2>&1`
-        if test $? -eq 0; then
+        if test $ax_python_devel_found = yes; then
+           #
+           # Check if you have distutils, else fail
+           #
+           AC_MSG_CHECKING([for the sysconfig Python package])
+           ac_sysconfig_result=`$PYTHON -c "import sysconfig" 2>&1`
+           if test $? -eq 0; then
                 AC_MSG_RESULT([yes])
-        else
+                IMPORT_SYSCONFIG="import sysconfig"
+           else
                 AC_MSG_RESULT([no])
-                AC_MSG_ERROR([cannot import Python module "distutils".
+
+                AC_MSG_CHECKING([for the distutils Python package])
+                ac_sysconfig_result=`$PYTHON -c "from distutils import sysconfig" 2>&1`
+                if test $? -eq 0; then
+                        AC_MSG_RESULT([yes])
+                        IMPORT_SYSCONFIG="from distutils import sysconfig"
+                else
+                        AC_MSG_WARN([cannot import Python module "distutils".
 Please check your Python installation. The error was:
-$ac_distutils_result])
-                PYTHON_VERSION=""
+$ac_sysconfig_result])
+                        if ! $ax_python_devel_optional; then
+                           AC_MSG_ERROR([Giving up])
+                        fi
+                        ax_python_devel_found=no
+                        PYTHON_VERSION=""
+                fi
+           fi
         fi
 
-        #
-        # Check for Python include path
-        #
-        AC_MSG_CHECKING([for Python include path])
-        if test -z "$PYTHON_CPPFLAGS"; then
-                python_path=`$PYTHON -c "import distutils.sysconfig; \
-                        print (distutils.sysconfig.get_python_inc ());"`
-                plat_python_path=`$PYTHON -c "import distutils.sysconfig; \
-                        print (distutils.sysconfig.get_python_inc (plat_specific=1));"`
+        if test $ax_python_devel_found = yes; then
+           #
+           # Check for Python include path
+           #
+           AC_MSG_CHECKING([for Python include path])
+           if test -z "$PYTHON_CPPFLAGS"; then
+                if test "$IMPORT_SYSCONFIG" = "import sysconfig"; then
+                        # sysconfig module has different functions
+                        python_path=`$PYTHON -c "$IMPORT_SYSCONFIG; \
+                                print (sysconfig.get_path ('include'));"`
+                        plat_python_path=`$PYTHON -c "$IMPORT_SYSCONFIG; \
+                                print (sysconfig.get_path ('platinclude'));"`
+                else
+                        # old distutils way
+                        python_path=`$PYTHON -c "$IMPORT_SYSCONFIG; \
+                                print (sysconfig.get_python_inc ());"`
+                        plat_python_path=`$PYTHON -c "$IMPORT_SYSCONFIG; \
+                                print (sysconfig.get_python_inc (plat_specific=1));"`
+                fi
                 if test -n "${python_path}"; then
                         if test "${plat_python_path}" != "${python_path}"; then
                                 python_path="-I$python_path -I$plat_python_path"
@@ -164,22 +243,22 @@ $ac_distutils_result])
                         fi
                 fi
                 PYTHON_CPPFLAGS=$python_path
-        fi
-        AC_MSG_RESULT([$PYTHON_CPPFLAGS])
-        AC_SUBST([PYTHON_CPPFLAGS])
+           fi
+           AC_MSG_RESULT([$PYTHON_CPPFLAGS])
+           AC_SUBST([PYTHON_CPPFLAGS])
 
-        #
-        # Check for Python library path
-        #
-        AC_MSG_CHECKING([for Python library path])
-        if test -z "$PYTHON_LIBS"; then
+           #
+           # Check for Python library path
+           #
+           AC_MSG_CHECKING([for Python library path])
+           if test -z "$PYTHON_LIBS"; then
                 # (makes two attempts to ensure we've got a version number
                 # from the interpreter)
                 ac_python_version=`cat<<EOD | $PYTHON -
 
 # join all versioning strings, on some systems
 # major/minor numbers could be in different list elements
-from distutils.sysconfig import *
+from sysconfig import *
 e = get_config_var('VERSION')
 if e is not None:
         print(e)
@@ -190,7 +269,7 @@ EOD`
                                 ac_python_version=$PYTHON_VERSION
                         else
                                 ac_python_version=`$PYTHON -c "import sys; \
-                                        print (sys.version[[:3]])"`
+                                        print ("%d.%d" % sys.version_info[[:2]])"`
                         fi
                 fi
 
@@ -202,8 +281,8 @@ EOD`
                 ac_python_libdir=`cat<<EOD | $PYTHON -
 
 # There should be only one
-import distutils.sysconfig
-e = distutils.sysconfig.get_config_var('LIBDIR')
+$IMPORT_SYSCONFIG
+e = sysconfig.get_config_var('LIBDIR')
 if e is not None:
         print (e)
 EOD`
@@ -211,8 +290,8 @@ EOD`
                 # Now, for the library:
                 ac_python_library=`cat<<EOD | $PYTHON -
 
-import distutils.sysconfig
-c = distutils.sysconfig.get_config_vars()
+$IMPORT_SYSCONFIG
+c = sysconfig.get_config_vars()
 if 'LDVERSION' in c:
         print ('python'+c[['LDVERSION']])
 else:
@@ -231,83 +310,140 @@ EOD`
                 else
                         # old way: use libpython from python_configdir
                         ac_python_libdir=`$PYTHON -c \
-                          "from distutils.sysconfig import get_python_lib as f; \
+                          "from sysconfig import get_python_lib as f; \
                           import os; \
                           print (os.path.join(f(plat_specific=1, standard_lib=1), 'config'));"`
                         PYTHON_LIBS="-L$ac_python_libdir -lpython$ac_python_version"
                 fi
 
-                if test -z "PYTHON_LIBS"; then
-                        AC_MSG_ERROR([
+                if test -z "$PYTHON_LIBS"; then
+                        AC_MSG_WARN([
   Cannot determine location of your Python DSO. Please check it was installed with
   dynamic libraries enabled, or try setting PYTHON_LIBS by hand.
                         ])
+                        if ! $ax_python_devel_optional; then
+                           AC_MSG_ERROR([Giving up])
+                        fi
+                        ax_python_devel_found=no
+                        PYTHON_VERSION=""
                 fi
+           fi
         fi
-        AC_MSG_RESULT([$PYTHON_LIBS])
-        AC_SUBST([PYTHON_LIBS])
 
-        #
-        # Check for site packages
-        #
-        AC_MSG_CHECKING([for Python site-packages path])
-        if test -z "$PYTHON_SITE_PKG"; then
-                PYTHON_SITE_PKG=`$PYTHON -c "import distutils.sysconfig; \
-                        print (distutils.sysconfig.get_python_lib(0,0));"`
-        fi
-        AC_MSG_RESULT([$PYTHON_SITE_PKG])
-        AC_SUBST([PYTHON_SITE_PKG])
+        if test $ax_python_devel_found = yes; then
+           AC_MSG_RESULT([$PYTHON_LIBS])
+           AC_SUBST([PYTHON_LIBS])
 
-        #
-        # libraries which must be linked in when embedding
-        #
-        AC_MSG_CHECKING(python extra libraries)
-        if test -z "$PYTHON_EXTRA_LIBS"; then
-           PYTHON_EXTRA_LIBS=`$PYTHON -c "import distutils.sysconfig; \
-                conf = distutils.sysconfig.get_config_var; \
+           #
+           # Check for site packages
+           #
+           AC_MSG_CHECKING([for Python site-packages path])
+           if test -z "$PYTHON_SITE_PKG"; then
+                if test "$IMPORT_SYSCONFIG" = "import sysconfig"; then
+                        PYTHON_SITE_PKG=`$PYTHON -c "
+$IMPORT_SYSCONFIG;
+if hasattr(sysconfig, 'get_default_scheme'):
+    scheme = sysconfig.get_default_scheme()
+else:
+    scheme = sysconfig._get_default_scheme()
+if scheme == 'posix_local':
+    # Debian's default scheme installs to /usr/local/ but we want to find headers in /usr/
+    scheme = 'posix_prefix'
+prefix = '$prefix'
+if prefix == 'NONE':
+    prefix = '$ac_default_prefix'
+sitedir = sysconfig.get_path('purelib', scheme, vars={'base': prefix})
+print(sitedir)"`
+                else
+                        # distutils.sysconfig way
+                        PYTHON_SITE_PKG=`$PYTHON -c "$IMPORT_SYSCONFIG; \
+                                print (sysconfig.get_python_lib(0,0));"`
+                fi
+           fi
+           AC_MSG_RESULT([$PYTHON_SITE_PKG])
+           AC_SUBST([PYTHON_SITE_PKG])
+
+           #
+           # Check for platform-specific site packages
+           #
+           AC_MSG_CHECKING([for Python platform specific site-packages path])
+           if test -z "$PYTHON_PLATFORM_SITE_PKG"; then
+                if test "$IMPORT_SYSCONFIG" = "import sysconfig"; then
+                        PYTHON_PLATFORM_SITE_PKG=`$PYTHON -c "
+$IMPORT_SYSCONFIG;
+if hasattr(sysconfig, 'get_default_scheme'):
+    scheme = sysconfig.get_default_scheme()
+else:
+    scheme = sysconfig._get_default_scheme()
+if scheme == 'posix_local':
+    # Debian's default scheme installs to /usr/local/ but we want to find headers in /usr/
+    scheme = 'posix_prefix'
+prefix = '$prefix'
+if prefix == 'NONE':
+    prefix = '$ac_default_prefix'
+sitedir = sysconfig.get_path('platlib', scheme, vars={'platbase': prefix})
+print(sitedir)"`
+                else
+                        # distutils.sysconfig way
+                        PYTHON_PLATFORM_SITE_PKG=`$PYTHON -c "$IMPORT_SYSCONFIG; \
+                                print (sysconfig.get_python_lib(1,0));"`
+                fi
+           fi
+           AC_MSG_RESULT([$PYTHON_PLATFORM_SITE_PKG])
+           AC_SUBST([PYTHON_PLATFORM_SITE_PKG])
+
+           #
+           # libraries which must be linked in when embedding
+           #
+           AC_MSG_CHECKING(python extra libraries)
+           if test -z "$PYTHON_EXTRA_LIBS"; then
+              PYTHON_EXTRA_LIBS=`$PYTHON -c "$IMPORT_SYSCONFIG; \
+                conf = sysconfig.get_config_var; \
                 print (conf('LIBS') + ' ' + conf('SYSLIBS'))"`
-        fi
-        AC_MSG_RESULT([$PYTHON_EXTRA_LIBS])
-        AC_SUBST(PYTHON_EXTRA_LIBS)
+           fi
+           AC_MSG_RESULT([$PYTHON_EXTRA_LIBS])
+           AC_SUBST(PYTHON_EXTRA_LIBS)
 
-        #
-        # linking flags needed when embedding
-        #
-        AC_MSG_CHECKING(python extra linking flags)
-        if test -z "$PYTHON_EXTRA_LDFLAGS"; then
-                PYTHON_EXTRA_LDFLAGS=`$PYTHON -c "import distutils.sysconfig; \
-                        conf = distutils.sysconfig.get_config_var; \
+           #
+           # linking flags needed when embedding
+           #
+           AC_MSG_CHECKING(python extra linking flags)
+           if test -z "$PYTHON_EXTRA_LDFLAGS"; then
+                PYTHON_EXTRA_LDFLAGS=`$PYTHON -c "$IMPORT_SYSCONFIG; \
+                        conf = sysconfig.get_config_var; \
                         print (conf('LINKFORSHARED'))"`
-        fi
-        AC_MSG_RESULT([$PYTHON_EXTRA_LDFLAGS])
-        AC_SUBST(PYTHON_EXTRA_LDFLAGS)
+                # Hack for macos, it sticks this in here.
+                PYTHON_EXTRA_LDFLAGS=`echo $PYTHON_EXTRA_LDFLAGS | sed 's/CoreFoundation.*$/CoreFoundation/'`
+           fi
+           AC_MSG_RESULT([$PYTHON_EXTRA_LDFLAGS])
+           AC_SUBST(PYTHON_EXTRA_LDFLAGS)
 
-        #
-        # final check to see if everything compiles alright
-        #
-        AC_MSG_CHECKING([consistency of all components of python development environment])
-        # save current global flags
-        ac_save_LIBS="$LIBS"
-        ac_save_LDFLAGS="$LDFLAGS"
-        ac_save_CPPFLAGS="$CPPFLAGS"
-        LIBS="$ac_save_LIBS $PYTHON_LIBS $PYTHON_EXTRA_LIBS $PYTHON_EXTRA_LIBS"
-        LDFLAGS="$ac_save_LDFLAGS $PYTHON_EXTRA_LDFLAGS"
-        CPPFLAGS="$ac_save_CPPFLAGS $PYTHON_CPPFLAGS"
-        AC_LANG_PUSH([C])
-        AC_LINK_IFELSE([
+           #
+           # final check to see if everything compiles alright
+           #
+           AC_MSG_CHECKING([consistency of all components of python development environment])
+           # save current global flags
+           ac_save_LIBS="$LIBS"
+           ac_save_LDFLAGS="$LDFLAGS"
+           ac_save_CPPFLAGS="$CPPFLAGS"
+           LIBS="$ac_save_LIBS $PYTHON_LIBS $PYTHON_EXTRA_LIBS"
+           LDFLAGS="$ac_save_LDFLAGS $PYTHON_EXTRA_LDFLAGS"
+           CPPFLAGS="$ac_save_CPPFLAGS $PYTHON_CPPFLAGS"
+           AC_LANG_PUSH([C])
+           AC_LINK_IFELSE([
                 AC_LANG_PROGRAM([[#include <Python.h>]],
                                 [[Py_Initialize();]])
                 ],[pythonexists=yes],[pythonexists=no])
-        AC_LANG_POP([C])
-        # turn back to default flags
-        CPPFLAGS="$ac_save_CPPFLAGS"
-        LIBS="$ac_save_LIBS"
-        LDFLAGS="$ac_save_LDFLAGS"
+           AC_LANG_POP([C])
+           # turn back to default flags
+           CPPFLAGS="$ac_save_CPPFLAGS"
+           LIBS="$ac_save_LIBS"
+           LDFLAGS="$ac_save_LDFLAGS"
 
-        AC_MSG_RESULT([$pythonexists])
+           AC_MSG_RESULT([$pythonexists])
 
-        if test ! "x$pythonexists" = "xyes"; then
-           AC_MSG_FAILURE([
+           if test ! "x$pythonexists" = "xyes"; then
+              AC_MSG_WARN([
   Could not link test program to Python. Maybe the main Python library has been
   installed in some non-standard library path. If so, pass it to configure,
   via the LIBS environment variable.
@@ -317,8 +453,13 @@ EOD`
    You probably have to install the development version of the Python package
    for your distribution.  The exact name of this package varies among them.
   ============================================================================
-           ])
-          PYTHON_VERSION=""
+              ])
+              if ! $ax_python_devel_optional; then
+                 AC_MSG_ERROR([Giving up])
+              fi
+              ax_python_devel_found=no
+              PYTHON_VERSION=""
+           fi
         fi
 
         #