python3: Add compatibility header file with necessary macros

Signed-off-by: Lumir Balhar <lbalhar@redhat.com>
Signed-off-by: Jiri Kastner <jkastner@redhat.com>

python-schedutils/py3compat.h

diff --git a/python-schedutils/py3compat.h b/python-schedutils/py3compat.h
new file mode 100644
index 0000000..625cddf
--- /dev/null
+++ b/python-schedutils/py3compat.h
@@ -0,0 +1,60 @@
+/*
+   Python 3 compatibility macros
+   Copyright (C) Petr Viktorin <pviktori@redhat.com> 2015
+*/
+
+#include <Python.h>
+
+#if PY_MAJOR_VERSION >= 3
+
+/***** Python 3 *****/
+
+#define IS_PY3 1
+
+/* Ints */
+
+#define PyInt_AsLong PyLong_AsLong
+
+/* Strings */
+
+#define PyStr_FromString PyUnicode_FromString
+
+/* Module init */
+
+#define MODULE_INIT_FUNC(name) \
+    PyMODINIT_FUNC PyInit_ ## name(void); \
+    PyMODINIT_FUNC PyInit_ ## name(void)
+
+#else
+
+/***** Python 2 *****/
+
+#define IS_PY3 0
+
+/* Strings */
+
+#define PyStr_FromString PyString_FromString
+
+/* Module init */
+
+#define PyModuleDef_HEAD_INIT 0
+
+typedef struct PyModuleDef {
+    int m_base;
+    const char* m_name;
+    const char* m_doc;
+    Py_ssize_t m_size;
+    PyMethodDef *m_methods;
+} PyModuleDef;
+
+#define PyModule_Create(def) \
+    Py_InitModule3((def)->m_name, (def)->m_methods, (def)->m_doc)
+
+#define MODULE_INIT_FUNC(name) \
+    static PyObject *PyInit_ ## name(void); \
+    void init ## name(void); \
+    void init ## name(void) { PyInit_ ## name(); } \
+    static PyObject *PyInit_ ## name(void)
+
+
+#endif