- Update macro with changes from Alan W. Irwin. Thanks, Alan!

git-svn-id: svn://svn.gna.org/svn/sgpemv2/trunk@579 3ecf2c5c-341e-0410-92b4-d18e462d057c

plugins/pyloader/m4/ac_python_devel.m4

@@ -1,25 +1,26 @@
 dnl @synopsis AC_PYTHON_DEVEL([version])
 dnl
-dnl Checks for Python and tries to get the include path to 'Python.h'.
+dnl Note: Defines as a precious variable "PYTHON_VERSION". Don't 
-dnl It provides the $(PYTHON_CPPFLAGS) and $(PYTHON_LDFLAGS) output
+dnl override it in your configure.ac.
-dnl variables.
+dnl
-dnl Also exports $(PYTHON_EXTRA_LIBS) and $(PYTHON_EXTRA_LDFLAGS)
+dnl This macro checks for Python and tries to get the include path to 
+dnl 'Python.h'. It provides the $(PYTHON_CPPFLAGS) and $(PYTHON_LDFLAGS) 
+dnl output variables.
+dnl It also exports $(PYTHON_EXTRA_LIBS) and $(PYTHON_EXTRA_LDFLAGS)
 dnl for embedding Python in your code.
 dnl
 dnl You can search for some particular version of Python by passing a
 dnl parameter to this macro, for example ">= '2.3.1'", or "== '2.4'".
 dnl Please note that you *have* to pass also an operator along
 dnl with the version to match, and pay special attention to the 
-dnl single quotes surrounding the version number.
+dnl single quotes surrounding the version number. 
+dnl Don't use "PYTHON_VERSION" for this: that environment variable is 
+dnl declared as precious and thus reserved for the end-user.
 dnl
-dnl If the user wants to employ a particular version of Python, she can
+dnl This macro should work for all versions of Python >= 2.1.0. As
-dnl now pass to configure the PYTHON_VERSION environment variable.
+dnl an end user, you can disable the check for the python version 
-dnl This is only limited by the macro parameter set by the packager.
+dnl by setting the PYTHON_NOVERSIONCHECK environment variable 
-dnl
+dnl to something else than the empty string.
-dnl This macro should work for all versions of Python >= 2.1.0. You can 
-dnl disable the check for the python version by setting the 
-dnl PYTHON_NOVERSIONCHECK environment variable to something else
-dnl than the empty string.
 dnl
 dnl If you need to use this macro for an older Python version, please 
 dnl contact the authors. We're always open for feedback.
@@ -46,6 +47,7 @@ AC_DEFUN([AC_PYTHON_DEVEL],[
 	AC_PATH_PROG([PYTHON],[python[$PYTHON_VERSION]])
 	if test -z "$PYTHON"; then
 	   AC_MSG_ERROR([Cannot find python$PYTHON_VERSION in your system path])
+	   PYTHON_VERSION=""
 	fi
 
 	#
@@ -66,7 +68,7 @@ variables PYTHON_CPPFLAGS, PYTHON_LDFLAGS, 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.
-])dnl
+])
 		else
 			AC_MSG_RESULT([skip at user request])
 		fi
@@ -90,7 +92,8 @@ to something else than an empty string.
 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.
-])dnl
+])
+			PYTHON_VERSION=""
 		fi
 	fi
 
@@ -106,6 +109,7 @@ variable to configure. See ``configure --help'' for reference.
 		AC_MSG_ERROR([cannot import Python module "distutils".
 Please check your Python installation. The error was:
 $ac_distutils_result])
+		PYTHON_VERSION=""
 	fi
 
 	#
@@ -188,7 +192,7 @@ $ac_distutils_result])
 	#	
 	# final check to see if everything compiles alright
 	#
-	AC_MSG_CHECKING([whether collected informations are consistent])
+	AC_MSG_CHECKING([consistency of all components of python development environment])
 	AC_LANG_PUSH([C])
 	# save current global flags
 	LIBS="$ac_save_LIBS $PYTHON_LDFLAGS"
@@ -206,12 +210,14 @@ $ac_distutils_result])
   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.
+  Example: ./configure LDFLAGS="-L/usr/non-standard-path/python/lib"
   ============================================================================
    ERROR!
    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=""
 	fi
 	AC_LANG_POP
 	# turn back to default flags