introduce custom postprocessing code to (partly) deal with module initialization; add selftests for same

3 files changed, 176 insertions, 36 deletions

diff --git a/2to3c b/2to3c
index ede6fb2..ae3233a 100755
--- a/2to3c
+++ b/2to3c
@@ -3,10 +3,12 @@
 def get_fixers():
     from fixes.typeobject import FixTypeobjectInitializers
     from fixes import CocciFix
+    from fixes.initmodule import FixInitModule
     fixes = [FixTypeobjectInitializers()]
     for filename in ['RO.cocci', 'int-to-long.cocci', 'ob_type.cocci', 
-                     'repr.cocci', 'init-module.cocci']:
+                     'repr.cocci']:
         fixes.append(CocciFix(filename))
+    fixes.append(FixInitModule())
     return fixes
 
 def fixup_content(content):
diff --git a/fixes/init-module.cocci b/fixes/init-module.cocci
index afeb89a..ca3bcc9 100644
--- a/fixes/init-module.cocci
+++ b/fixes/init-module.cocci
@@ -10,13 +10,43 @@ T FN(void) {
    ...
 }
 
+
+
+@@
+identifier MOD_VAR;
+expression MODULE_NAME, MODULE_METHODS, MODULE_DOC;
+expression E;
+@@
+   if (E) {
+-     return;
++     return MOD_ERROR_VAL;
+   }
+   ...
+   MOD_VAR = Py_InitModule3(MODULE_NAME, MODULE_METHODS, MODULE_DOC); 
+
+
+@@
+identifier MOD_VAR;
+expression MODULE_NAME, MODULE_METHODS, MODULE_DOC;
+expression E;
+@@
+   MOD_VAR = Py_InitModule3(MODULE_NAME, MODULE_METHODS, MODULE_DOC); 
+   ...
+   if (E) {
+-     return;
++     return MOD_ERROR_VAL;
+   }
+
+
 @@
 type mod_init_fn.T;
 identifier  mod_init_fn.FN;
 identifier  mod_init_fn.MOD_VAR;
 expression MODULE_NAME, MODULE_METHODS, MODULE_DOC;
+expression E;
+statement list SL;
 @@
-+ #if PY_MAJOR_VERSION >= 3
++struct __HASH_IF_PY_MAJOR_VERSION_ge_3;
 +static struct PyModuleDef moduledef = {
 +        PyModuleDef_HEAD_INIT,
 +        MODULE_NAME,     /* m_name */
@@ -28,45 +58,21 @@ expression MODULE_NAME, MODULE_METHODS, MODULE_DOC;
 +        NULL,        /* m_clear */
 +        NULL,        /* m_free */
 +};
-+#define MOD_ERROR_VAL NULL
-+#else
-+#endif
++struct __HASH_DEFINE__MOD_ERROR_VAL__NULL;
++struct __HASH_ELSE;
++struct __HASH_DEFINE__MOD_ERROR_VAL__;
++struct __HASH_ENDIF;
 
-T FN(void) {
+ T FN(void) {
    ...
 
-+ #if PY_MAJOR_VERSION >= 3
++__HASH_IF_PY_MAJOR_VERSION_ge_3;
 +    MOD_VAR = PyModule_Create(&moduledef);
-+ #else
++__HASH_ELSE;
      MOD_VAR = Py_InitModule3(MODULE_NAME, MODULE_METHODS, MODULE_DOC);
-+ #endif
-
-    ...
-}
-
-
++__HASH_ENDIF;
 
-@@
-type mod_init_fn.T;
-identifier mod_init_fn.FN;
-expression E;
-@@
-T FN(void) {
    ...
--  if (E) return;
-+  if (E) return MOD_ERROR_VAL;
-   ...
-}
+ }
+
 
-@@
-type mod_init_fn.T;
-identifier mod_init_fn.FN;
-identifier mod_init_fn.MOD_VAR;
-@@
-T FN(void) {
-   ...
--  return;
-+ #if PY_MAJOR_VERSION >= 3
-+  return MOD_VAR;
-+ #endif
-}
diff --git a/fixes/initmodule.py b/fixes/initmodule.py
new file mode 100644
index 0000000..c106079
--- /dev/null
+++ b/fixes/initmodule.py
@@ -0,0 +1,132 @@
+from fixes import CocciFix, FixTest
+class FixInitModule(CocciFix):
+    def __init__(self):
+        CocciFix.__init__(self, 'init-module.cocci')
+
+    def preprocess(self, string):
+        # FIXME
+        return string
+
+    def postprocess(self, string):
+        for (before, after) in [('struct __HASH_IF_PY_MAJOR_VERSION_ge_3;',
+                                 '#if PY_MAJOR_VERSION > 3'),
+                                ('struct __HASH_ELSE;',
+                                 '#else'),
+                                ('struct __HASH_DEFINE__MOD_ERROR_VAL__NULL;',
+                                 '#define MOD_ERROR_VAL NULL'),
+                                ('struct __HASH_DEFINE__MOD_ERROR_VAL__;',
+                                 '#define MOD_ERROR_VAL'),
+                                ('struct __HASH_ENDIF;',
+                                 '#endif'),
+                                ('__HASH_IF_PY_MAJOR_VERSION_ge_3;',
+                                 '#if PY_MAJOR_VERSION > 3'),
+                                ('__HASH_ELSE;',
+                                 '#else'),
+                                ('__HASH_ENDIF;',
+                                 '#endif'),
+                                ]:
+            string = string.replace(before, after)
+
+        # etc
+        return string
+
+    def transform(self, string):
+        # FIXME: preprocess
+        string = self.preprocess(string)
+        #print 'input:', repr(string)
+        string = CocciFix.transform(self, string)
+        #print 'output:', repr(string)
+        string = self.postprocess(string)
+        return string
+
+#import unittest
+class TestFixups(FixTest):
+    def setUp(self):
+        self.fixer = FixInitModule()
+
+    def test_fixups(self):
+        self.assertTransformsTo(self.fixer,
+                                '''
+PyMODINIT_FUNC
+initxx(void)
+{
+    PyObject *m;
+
+    if (something_that_can_fail() < 0)
+        return;
+
+    m = Py_InitModule3("xx", xx_methods, module_doc);
+    if (m == NULL)
+        return;
+
+    PyModule_AddObject(m, "Null", (PyObject *)&Null_Type);
+}
+''',
+                                '''
+#if PY_MAJOR_VERSION > 3
+static struct PyModuleDef moduledef = {
+    PyModuleDef_HEAD_INIT,
+    "xx",/* m_name */
+    module_doc,/* m_doc */
+    0,/* m_size */
+    xx_methods,/* m_methods */
+    NULL,/* m_reload */
+    NULL,/* m_traverse */
+    NULL,/* m_clear */
+    NULL,/* m_free */
+};
+#define MOD_ERROR_VAL NULL
+#else
+#define MOD_ERROR_VAL
+#endif
+PyMODINIT_FUNC
+initxx(void)
+{
+    PyObject *m;
+
+    if (something_that_can_fail() < 0)
+        return MOD_ERROR_VAL;
+
+    #if PY_MAJOR_VERSION > 3
+    m = PyModule_Create(&moduledef);
+    #else
+    m = Py_InitModule3("xx", xx_methods, module_doc);
+    #endif
+    if (m == NULL)
+        return MOD_ERROR_VAL;
+
+    PyModule_AddObject(m, "Null", (PyObject *)&Null_Type);
+}
+''')
+# FIXME: this should have a trailing:
+'''
+    #if PY_MAJOR_VERSION > 3
+    return m;
+    #endif
+'''
+# but I haven't figured out how to get spatch to add that whilst correctly
+# handling error paths
+
+# Some code that isn't handled yet:
+# Multiple error-handling paths:
+'''
+PyMODINIT_FUNC
+initxx(void)
+{
+    PyObject *m;
+
+    if (something_that_can_fail() < 0)
+        return;
+
+    m = Py_InitModule3("xx", xx_methods, module_doc);
+    if (m == NULL)
+        return;
+
+    if (PyType_Ready(&Null_Type) < 0)
+        return;
+    PyModule_AddObject(m, "Null", (PyObject *)&Null_Type);
+}
+'''
+
+if __name__ == '__main__':
+    unittest.main()