Update ax_python_devel.m4 macro

Also reorder its call in configure.ac which now allows the PYTHON_VERSION
environment variable to be recognized and processed correctly by the
build system.

Correctly add PYTHON_LIBS (correct ouput variable of AX_PYTHON_DEVEL) to the
Makefile for the Python bindings.

Update README.python for use of PYTHON_VERSION.

bindings/Makefile.am

@@ -3,7 +3,7 @@
 # more information on swig at http://www.swig.org
 #
 
-AM_CPPFLAGS = @AM_CPPFLAGS@ -I$(top_srcdir)/bindings @TCL_INCLUDE_SPEC@ @PYTHON_CPPFLAGS@
+AM_CPPFLAGS = @AM_CPPFLAGS@ -I$(top_srcdir)/bindings $(PYTHON_CPPFLAGS) @TCL_INCLUDE_SPEC@
 
 AM_CFLAGS = -fno-strict-aliasing
 
@@ -88,7 +88,7 @@ nodist_pyexec_PYTHON = Hamlib.py
 nodist__Hamlib_la_SOURCES = hamlibpy_wrap.c
 
 _Hamlib_la_LDFLAGS = -no-undefined -module -avoid-version
-_Hamlib_la_LIBADD = $(top_builddir)/src/libhamlib.la
+_Hamlib_la_LIBADD = $(top_builddir)/src/libhamlib.la $(PYTHON_LIBS)
 _Hamlib_ladir = $(pyexecdir)
 _Hamlib_la_LTLIBRARIES = $(pyexec_ltlib)
 
@@ -100,8 +100,8 @@ check-py: all-py
 Hamlib.py: hamlibpy_wrap.c
 
 hamlibpy_wrap.c: hamlib.swg $(SWGDEP)
-	$(SWIG) -python @AM_CPPFLAGS@ -I$(top_srcdir)/bindings -o $@ \
+	$(SWIG) -python $(AM_CPPFLAGS) -I$(top_srcdir)/bindings \
-		`test -f hamlib.swg || echo '$(srcdir)/'`hamlib.swg
+		-o $@ `test -f hamlib.swg || echo '$(srcdir)/'`hamlib.swg
 
 install-py:
 clean-py:

bindings/README.python

@@ -37,6 +37,9 @@ its bindings first:
     make
     make install
 
+NOTE: Over time Python3 will become the default Python interpreter on most
+distributions and the extra step will be needed for Python2 as detailed below.
+
 At this point the Hamlib binaries, development files, and Python2 bindings
 will be installed to their customary locations under $HOME/local.
 
@@ -44,21 +47,20 @@ Examination of the configure script's output will confirm that Python2 is
 found and used as this extract shows:
 
 checking whether to build python binding and demo... yes
-checking for a Python interpreter with version >= 2.1... python
 checking for python... /usr/bin/python
-checking for python version... 2.7
-checking for python platform... linux2
-checking for python script directory... ${prefix}/lib64/python2.7/site-packages
-checking for python extension module directory... ${exec_prefix}/lib64/python2.7/site-packages
-checking for python2.7... (cached) /usr/bin/python
 checking for a version of Python >= '2.1.0'... yes
 checking for the distutils Python package... yes
 checking for Python include path... -I/usr/include/python2.7
 checking for Python library path... -L/usr/lib64 -lpython2.7
 checking for Python site-packages path... /usr/lib64/python2.7/site-packages
-checking python extra libraries...  -lpthread -ldl  -lutil
+checking python extra libraries... -lpthread -ldl  -lutil -lm
 checking python extra linking flags... -Xlinker -export-dynamic
 checking consistency of all components of python development environment... yes
+checking whether /usr/bin/python version is >= 2.1... yes
+checking for /usr/bin/python version... 2.7
+checking for /usr/bin/python platform... linux2
+checking for /usr/bin/python script directory... ${prefix}/lib64/python2.7/site-packages
+checking for /usr/bin/python extension module directory... ${exec_prefix}/lib64/python2.7/site-packages
 
 At this point the file pytest.py in the source bindings directory may be
 run as a test.  If an error is given that the Hamlib module cannot be
@@ -66,37 +68,52 @@ found, see below.
 
 The next step is to configure and build for Python3:
 
+    ../hamlib/configure --with-python-binding PYTHON_VERSION='3.6' --prefix=$HOME/local
+
+If that doesn't work try:
+
     ../hamlib/configure --with-python-binding PYTHON=`which python3` --prefix=$HOME/local
+
+then do the build:
+
+    cd bindings
     make
 
-Here the PYTHON environment variable is set to the first python3 executable
+NOTE: By changing the current directory to 'bindings', only the new Python3
-found in the path (python3 may be a symbolic link, which is fine).  This
+module will be compiled, which speeds things up considerably.
-may be unwanted behavior if multiple versions of Python are installed.
+
+Here the PYTHON_VERSION environment variable is set to the Major.minor version
+of Python we wish to build against.  The build system should be able to set
+everything correctly from this environment variable.  If not, try the second
+example line which sets the PYTHON environment variable to the first python3
+executable found in the path (python3 may be a symbolic link, which is fine).
+This may be unwanted behavior if multiple versions of Python are installed so
+a specific version with the full path may also be provided.
 
 Python3 was found as shown in this configure output extract:
 
 checking whether to build python binding and demo... yes
-checking whether /usr/bin/python3 version is >= 2.1... yes
+checking for python3.6... /usr/bin/python3.6
-checking for /usr/bin/python3 version... 3.6
-checking for /usr/bin/python3 platform... linux
-checking for /usr/bin/python3 script directory... ${prefix}/lib64/python3.6/site-packages
-checking for /usr/bin/python3 extension module directory... ${exec_prefix}/lib64/python3.6/site-packages
-checking for python3.6... /usr/bin/python3
 checking for a version of Python >= '2.1.0'... yes
 checking for the distutils Python package... yes
 checking for Python include path... -I/usr/include/python3.6m
 checking for Python library path... -L/usr/lib64 -lpython3.6m
 checking for Python site-packages path... /usr/lib64/python3.6/site-packages
-checking python extra libraries...  -lpthread -ldl  -lutil
+checking python extra libraries... -lpthread -ldl  -lutil -lm
 checking python extra linking flags... -Xlinker -export-dynamic
 checking consistency of all components of python development environment... yes
+checking whether /usr/bin/python3.6 version is >= 2.1... yes
+checking for /usr/bin/python3.6 version... 3.6
+checking for /usr/bin/python3.6 platform... linux
+checking for /usr/bin/python3.6 script directory... ${prefix}/lib64/python3.6/site-packages
+checking for /usr/bin/python3.6 extension module directory... ${exec_prefix}/lib64/python3.6/site-packages
 
 Since all the Makefiles were regenerated by the second run of configure,
 hamlib will be compiled again.
 
-Next install the Python3 bindings:
+Next install only the Python3 bindings (still in 'bindings' as the current
+directory):
 
-    cd bindings
     make install
 
 In this case, only the generated files in 'bindings' will be installed
@@ -162,6 +179,11 @@ interpreter was started from and various system directories.
 Far more information than this is available in the relevant Python
 documentation, but this should get your scripts working.
 
+Removing (uninstalling) the bindings can be done from the 'bindings'
+directory.  Just be sure that 'configure' is run with the options for either
+Python2 or Python3 first so that 'bindings/Makefile' will generated for the
+version to be removed.
+
 As always, feedback is welcome:
 
    Hamlib Developers <hamlib-developer@lists.sourceforge.net>

bindings/py3test.py

@@ -55,7 +55,7 @@ def StartUp():
     print("Model:\t\t\t%s" % my_rig.caps.model_name)
     print("Manufacturer:\t\t%s" % my_rig.caps.mfg_name)
     print("Backend version:\t%s" % my_rig.caps.version)
-    print("Backend license:\t%s" % my_rig.caps.copyright)
+    print("Backend status:\t\t%s" % Hamlib.rig_strstatus(my_rig.caps.status))
     print("Rig info:\t\t%s" % my_rig.get_info())
 
     my_rig.set_level("VOX",  1)
@@ -75,7 +75,7 @@ def StartUp():
     print("status:\t\t\t%s - %s" % (my_rig.error_status,
                                     Hamlib.rigerror(my_rig.error_status)))
 
-    print("AF level:\t\t%s" % my_rig.get_level_f(Hamlib.RIG_LEVEL_AF))
+    print("AF level:\t\t%0.2f" % my_rig.get_level_f(Hamlib.RIG_LEVEL_AF))
     print("strength:\t\t%s" % my_rig.get_level_i(Hamlib.RIG_LEVEL_STRENGTH))
     print("status:\t\t\t%s" % my_rig.error_status)
     print("status(str):\t\t%s" % Hamlib.rigerror(my_rig.error_status))

bindings/pytest.py

@@ -19,7 +19,7 @@ def StartUp():
     Hamlib.rig_set_debug(Hamlib.RIG_DEBUG_NONE)
 
     # Init RIG_MODEL_DUMMY
-    my_rig = Hamlib.Rig (Hamlib.RIG_MODEL_DUMMY)
+    my_rig = Hamlib.Rig(Hamlib.RIG_MODEL_DUMMY)
     my_rig.set_conf("rig_pathname", "/dev/Rig")
     my_rig.set_conf("retry", "5")
 
@@ -55,7 +55,7 @@ def StartUp():
     print "Model:\t\t\t", my_rig.caps.model_name
     print "Manufacturer:\t\t", my_rig.caps.mfg_name
     print "Backend version:\t", my_rig.caps.version
-    print "Backend license:\t", my_rig.caps.copyright
+    print "Backend status:\t\t", Hamlib.rig_strstatus(my_rig.caps.status)
     print "Rig info:\t\t", my_rig.get_info()
 
     my_rig.set_level("VOX",  1)
@@ -70,7 +70,7 @@ def StartUp():
 
     print "Setting AF to %0.2f...." % (af)
 
-    my_rig.set_level ("AF", af)
+    my_rig.set_level("AF", af)
 
     print "status:\t\t\t%s - %s" % (my_rig.error_status,
                                     Hamlib.rigerror(my_rig.error_status))

configure.ac

@@ -508,8 +508,9 @@ AC_MSG_RESULT([$cf_with_python_binding])
 
 dnl AX_PYTHON_DEVEL from macros/ax_python_devel.m4
 AS_IF([test x"${cf_with_python_binding}" = "xyes"],[
+    dnl Order matters!  AX_PYTHON_DEVEL must be first for PYTHON_VERSION to be honored.
+    AX_PYTHON_DEVEL([">='2.1'"])
     AM_PATH_PYTHON([2.1],, [:])
-    AX_PYTHON_DEVEL
 
     BINDING_LIST="${BINDING_LIST} python"
     BINDING_ALL="${BINDING_ALL} all-py"

macros/ax_python_devel.m4

@@ -1,5 +1,5 @@
 # ===========================================================================
-#      http://www.gnu.org/software/autoconf-archive/ax_python_devel.html
+#     https://www.gnu.org/software/autoconf-archive/ax_python_devel.html
 # ===========================================================================
 #
 # SYNOPSIS
@@ -12,8 +12,8 @@
 #   in your configure.ac.
 #
 #   This macro checks for Python and tries to get the include path to
-#   'Python.h'. It provides the $(PYTHON_CPPFLAGS) and $(PYTHON_LDFLAGS)
+#   'Python.h'. It provides the $(PYTHON_CPPFLAGS) and $(PYTHON_LIBS) output
-#   output variables. It also exports $(PYTHON_EXTRA_LIBS) and
+#   variables. It also exports $(PYTHON_EXTRA_LIBS) and
 #   $(PYTHON_EXTRA_LDFLAGS) for embedding Python in your code.
 #
 #   You can search for some particular version of Python by passing a
@@ -52,7 +52,7 @@
 #   Public License for more details.
 #
 #   You should have received a copy of the GNU General Public License along
-#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#   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
@@ -67,7 +67,7 @@
 #   modified version of the Autoconf Macro, you may extend this special
 #   exception to the GPL to apply to your modified version as well.
 
-#serial 15
+#serial 21
 
 AU_ALIAS([AC_PYTHON_DEVEL], [AX_PYTHON_DEVEL])
 AC_DEFUN([AX_PYTHON_DEVEL],[
@@ -99,7 +99,7 @@ AC_DEFUN([AX_PYTHON_DEVEL],[
 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
-variables PYTHON_CPPFLAGS, PYTHON_LDFLAGS, PYTHON_SITE_PKG,
+variables PYTHON_CPPFLAGS, PYTHON_LIBS, PYTHON_SITE_PKG,
 PYTHON_EXTRA_LIBS and PYTHON_EXTRA_LDFLAGS by hand.
 Moreover, to disable this check, set PYTHON_NOVERSIONCHECK
 to something else than an empty string.
@@ -137,7 +137,7 @@ variable to configure. See ``configure --help'' for reference.
 	#
 	AC_MSG_CHECKING([for the distutils Python package])
 	ac_distutils_result=`$PYTHON -c "import distutils" 2>&1`
-	if test -z "$ac_distutils_result"; then
+	if test $? -eq 0; then
 		AC_MSG_RESULT([yes])
 	else
 		AC_MSG_RESULT([no])
@@ -172,7 +172,7 @@ $ac_distutils_result])
 	# Check for Python library path
 	#
 	AC_MSG_CHECKING([for Python library path])
-	if test -z "$PYTHON_LDFLAGS"; then
+	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 | $PYTHON -
@@ -227,25 +227,25 @@ EOD`
 		then
 			# use the official shared library
 			ac_python_library=`echo "$ac_python_library" | sed "s/^lib//"`
-			PYTHON_LDFLAGS="-L$ac_python_libdir -l$ac_python_library"
+			PYTHON_LIBS="-L$ac_python_libdir -l$ac_python_library"
 		else
 			# old way: use libpython from python_configdir
 			ac_python_libdir=`$PYTHON -c \
 			  "from distutils.sysconfig import get_python_lib as f; \
 			  import os; \
 			  print (os.path.join(f(plat_specific=1, standard_lib=1), 'config'));"`
-			PYTHON_LDFLAGS="-L$ac_python_libdir -lpython$ac_python_version"
+			PYTHON_LIBS="-L$ac_python_libdir -lpython$ac_python_version"
 		fi
 
-		if test -z "PYTHON_LDFLAGS"; then
+		if test -z "PYTHON_LIBS"; then
 			AC_MSG_ERROR([
   Cannot determine location of your Python DSO. Please check it was installed with
-  dynamic libraries enabled, or try setting PYTHON_LDFLAGS by hand.
+  dynamic libraries enabled, or try setting PYTHON_LIBS by hand.
 			])
 		fi
 	fi
-	AC_MSG_RESULT([$PYTHON_LDFLAGS])
+	AC_MSG_RESULT([$PYTHON_LIBS])
-	AC_SUBST([PYTHON_LDFLAGS])
+	AC_SUBST([PYTHON_LIBS])
 
 	#
 	# Check for site packages
@@ -265,7 +265,7 @@ EOD`
 	if test -z "$PYTHON_EXTRA_LIBS"; then
 	   PYTHON_EXTRA_LIBS=`$PYTHON -c "import distutils.sysconfig; \
                 conf = distutils.sysconfig.get_config_var; \
-                print (conf('LOCALMODLIBS') + ' ' + conf('LIBS'))"`
+                print (conf('LIBS') + ' ' + conf('SYSLIBS'))"`
 	fi
 	AC_MSG_RESULT([$PYTHON_EXTRA_LIBS])
 	AC_SUBST(PYTHON_EXTRA_LIBS)
@@ -288,8 +288,10 @@ EOD`
 	AC_MSG_CHECKING([consistency of all components of python development environment])
 	# save current global flags
 	ac_save_LIBS="$LIBS"
+	ac_save_LDFLAGS="$LDFLAGS"
 	ac_save_CPPFLAGS="$CPPFLAGS"
-	LIBS="$ac_save_LIBS $PYTHON_LDFLAGS $PYTHON_EXTRA_LDFLAGS $PYTHON_EXTRA_LIBS"
+	LIBS="$ac_save_LIBS $PYTHON_LIBS $PYTHON_EXTRA_LIBS $PYTHON_EXTRA_LIBS"
+	LDFLAGS="$ac_save_LDFLAGS $PYTHON_EXTRA_LDFLAGS"
 	CPPFLAGS="$ac_save_CPPFLAGS $PYTHON_CPPFLAGS"
 	AC_LANG_PUSH([C])
 	AC_LINK_IFELSE([
@@ -300,6 +302,7 @@ EOD`
 	# turn back to default flags
 	CPPFLAGS="$ac_save_CPPFLAGS"
 	LIBS="$ac_save_LIBS"
+	LDFLAGS="$ac_save_LDFLAGS"
 
 	AC_MSG_RESULT([$pythonexists])
 
@@ -307,8 +310,8 @@ EOD`
 	   AC_MSG_FAILURE([
   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 LDFLAGS environment variable.
+  via the LIBS environment variable.
-  Example: ./configure LDFLAGS="-L/usr/non-standard-path/python/lib"
+  Example: ./configure LIBS="-L/usr/non-standard-path/python/lib"
   ============================================================================
    ERROR!
    You probably have to install the development version of the Python package