use compile_time_env option in cythonize for PY_MAJOR_VERSION

Author: videlec

cypari2/convert.pyx

@@ -55,8 +55,6 @@ from .stack cimport new_gen
 cdef extern from *:
     Py_ssize_t* Py_SIZE_PTR "&Py_SIZE"(object)
 
-include "system.pxi"
-
 ####################################
 # Integers
 ####################################

cypari2/gen.pyx

@@ -84,10 +84,7 @@ from .pari_instance cimport (prec_bits_to_words, prec_words_to_bits,
 from .stack cimport new_gen, new_gen_noclear, clear_stack
 from .closure cimport objtoclosure
 
-
 include 'auto_gen.pxi'
-include 'system.pxi'
-
 
 @cython.final
 cdef class Gen(Gen_auto):

cypari2/pari_instance.pyx

@@ -239,8 +239,6 @@ from .convert cimport new_gen_from_double
 from .handle_error cimport _pari_init_error_handling
 from .closure cimport _pari_init_closure
 
-include "system.pxi"
-
 # Default precision (in PARI words) for the PARI library interface,
 # when no explicit precision is given and the inputs are exact.
 cdef long prec = prec_bits_to_words(53)

setup.py

@@ -28,14 +28,9 @@ def finalize_options(self):
         from autogen import rebuild
         rebuild()
 
-        # Write compilation constants in system.pxi
-        import sys
-        with open('cypari2/system.pxi', 'w') as output:
-            output.write('DEF PY_MAJOR_VERSION = %d\n' % sys.version_info.major)
-            output.write('DEF PY_MINOR_VERSION = %d\n' % sys.version_info.minor)
-
         self.distribution.ext_modules[:] = cythonize(
-            self.distribution.ext_modules, include_path=sys.path)
+            self.distribution.ext_modules, include_path=sys.path,
+            compile_time_env={'PY_MAJOR_VERSION': sys.version_info.major})
         _build_ext.finalize_options(self)