Add a __version__ attribute onto the module

When building a module from inside the git tree, the version
will also be "tagged" with the latest commit hash

Change-Id: Ic4b3d4072afcfccbb7bcbe09afc49f950d25e535

Author: R. Tyler Ballance

setup.py

@@ -11,6 +11,15 @@
 except ImportError:
     from distutils.core import setup, Extension
 
+version = '0.3.6'
+if os.path.exists('.git'):
+    try:
+        commit = subprocess.Popen(['git', 'log', '--max-count=1', '--format=%h'], stdout=subprocess.PIPE).communicate()[0]
+        version = '%s-%s' % (version, commit.strip())
+    except:
+        pass
+
+
 base_modules = [
     Extension('yajl',  [
                 'yajl.c',
@@ -26,7 +35,7 @@
                 'yajl/src/yajl_parser.c',
             ],
             include_dirs=('.', 'includes/', 'yajl/src'),
-            extra_compile_args=['-Wall',],
+            extra_compile_args=['-Wall', '-DMOD_VERSION="%s"' % version],
             language='c'),
         ]
 
@@ -37,7 +46,7 @@
 setup_kwargs = dict(
     name = 'yajl',
     description = '''A CPython module for Yet-Another-Json-Library''',
-    version = '0.3.6',
+    version = version,
     author = 'R. Tyler Ballance',
     author_email = '[email protected]',
     url = 'http://rtyler.github.com/py-yajl',

yajl.c

@@ -409,6 +409,9 @@ PyMODINIT_FUNC PyInit_yajl(void)
 );
 #endif
 
+    PyObject *version = PyUnicode_FromString(MOD_VERSION);
+    PyModule_AddObject(module, "__version__", version);
+
     YajlDecoderType.tp_new = PyType_GenericNew;
     if (PyType_Ready(&YajlDecoderType) < 0) {
         goto bad_exit;