[python bindings] Fix Cursor.result_type for ObjC method declarations - Bug 36677

[kjteske]

Summary

In cindex.py, Cursor.result_type called into the wrong libclang
function, causing cursors for ObjC method declarations to return invalid
result types. Fixes Bug 36677.

[kjteske]

First time llvm contributor here, so no commit access. @jbcoe, can you commit this for me?

[jbcoe]

Congrats on your first patch! I can commit this for you.

bindings/python/clang/cindex.py

def canonical(self):
             self._canonical = conf.lib.clang_getCanonicalCursor(self)
 
         return self._canonical
 
     @property
     def result_type(self):
         """Retrieve the Type of the result for this Cursor."""
         if not hasattr(self, '_result_type'):
-            self._result_type = conf.lib.clang_getResultType(self.type)
+            self._result_type = conf.lib.clang_getCursorResultType(self)
 
         return self._result_type
 
     @property
     def exception_specification_kind(self):
         '''
         Retrieve the exception specification kind, which is one of the values
         from the ExceptionSpecificationKind enumeration.
#  [CXTUResourceUsage]),
    [Cursor],
    Cursor,
    Cursor.from_result),
 
   ("clang_getCursorReferenceNameRange",
    [Cursor, c_uint, c_uint],
    SourceRange),
 
+  ("clang_getCursorResultType",
+   [Cursor],
+   Type,
+   Type.from_result),
+
   ("clang_getCursorSemanticParent",
    [Cursor],
    Cursor,
    Cursor.from_cursor_result),
 
   ("clang_getCursorSpelling",
    [Cursor],
    _CXString,

bindings/python/tests/cindex/test_cursor.py

class TestCursor(unittest.TestCase):
     def test_result_type(self):
         tu = get_tu('int foo();')
         foo = get_cursor(tu, 'foo')
 
         self.assertIsNotNone(foo)
         t = foo.result_type
         self.assertEqual(t.kind, TypeKind.INT)
 
+    def test_result_type_objc_method_decl(self):
+        code = """\
+        @interface Interface : NSObject
+        -(void)voidMethod;
+        @end
+        """
+        tu = get_tu(code, lang='objc')
+        cursor = get_cursor(tu, 'voidMethod')
+        result_type = cursor.result_type
+        self.assertEqual(cursor.kind, CursorKind.OBJC_INSTANCE_METHOD_DECL)
+        self.assertEqual(result_type.kind, TypeKind.VOID)
+
     def test_availability(self):
         tu = get_tu('class A { A(A const&) = delete; };', lang='cpp')
 
         # AvailabilityKind.AVAILABLE
         cursor = get_cursor(tu, 'A')
         self.assertEqual(cursor.kind, CursorKind.CLASS_DECL)
         self.assertEqual(cursor.availability, AvailabilityKind.AVAILABLE)