update doc.

theano/compile/function_module.py

@@ -580,8 +580,8 @@ class Function(object):
             outputs = self.fn()
         except Exception:
             if hasattr(self.fn, 'position_of_error'):
-                # this is a new vm-provided function
-                # the C VM needs this because the exception manipulation
+                # this is a new vm-provided function or c linker
+                # they need this because the exception manipulation
                 # done by raise_with_op is not implemented in C.
                 if hasattr(self.fn, 'thunks'):
                     # For the CVM

theano/gof/link.py

@@ -63,8 +63,8 @@ def raise_with_op(op, thunk=None, exc_info=None):
 
     Parameters
     ----------
-    op : object
-        The Op object that resulted in the raised exception.
+    op : Apply node
+        The Apply node object that resulted in the raised exception.
     exc_info : tuple, optional
         A tuple containing the exception type, exception object and
         associated traceback, as would be returned by a call to