build: Tune M4 macros for our needs.

* m4/ax_python_devel.m4: Do not emit 'HAVE_PYTHON'.
* m4/python.m4 (_AM_PYTHON_INTERPRETER_LIST): Add newer Python
versions, drop older ones.  Also, sort the list with older versions at
the front, newer and generic versions towards the end.  This makes the
algorithm pick the lowest version that meets the version requirement.

Signed-off-by: Justus Winter <justus@g10code.com>

diff --git a/m4/ax_python_devel.m4 b/m4/ax_python_devel.m4
index de992c8..b990d5b 100644 (file)
--- a/m4/ax_python_devel.m4
+++ b/m4/ax_python_devel.m4
@@ -195,8 +195,11 @@ EOD`
                fi
 
                # Make the versioning information available to the compiler
-               AC_DEFINE_UNQUOTED([HAVE_PYTHON], ["$ac_python_version"],
-                                   [If available, contains the Python version number currently in use.])
+
+               # JW: We don't need it and it interferes with the hack
+               # to detect multiple Pyhton versions
+               #AC_DEFINE_UNQUOTED([HAVE_PYTHON], ["$ac_python_version"],
+                #                  [If available, contains the Python version number currently in use.])
 
                # First, the library directory:
                ac_python_libdir=`cat<<EOD | $PYTHON -

diff --git a/m4/python.m4 b/m4/python.m4
index 790e68b..13962f4 100644 (file)
--- a/m4/python.m4
+++ b/m4/python.m4
@@ -37,8 +37,8 @@ AC_DEFUN([AM_PATH_PYTHON],
   dnl Find a Python interpreter.  Python versions prior to 2.0 are not
   dnl supported. (2.0 was released on October 16, 2000).
   m4_define_default([_AM_PYTHON_INTERPRETER_LIST],
-[python python2 python3 python3.3 python3.2 python3.1 python3.0 python2.7 dnl
- python2.6 python2.5 python2.4 python2.3 python2.2 python2.1 python2.0])
+[python2.7 python2 python3.0 python3.1 python3.2 python3.3 python3.4 dnl
+ python3.5 python3.6 python3.7 python3.8 python3 python])
 
   AC_ARG_VAR([PYTHON], [the Python interpreter])