Restore node.op._op_use_c_code after changing it.

theano/gof/cc.py

@@ -1222,11 +1222,15 @@ class OpWiseCLinker(link.LocalLinker):
             for node in order:
                 # Maker sure we use the C version of the code whenever
                 # possible
+                old_value = node.op._op_use_c_code
+                try:
                     node.op._op_use_c_code = True
                     thunks += [node.op.make_thunk(node,
                                         storage_map,
                                         compute_map,
                                         no_recycling)]
+                finally:
+                    node.op._op_use_c_code = old_value
 
             for node_idx, node in enumerate(order):
 

theano/gof/link.py

@@ -401,11 +401,15 @@ class PerformLinker(LocalLinker):
         for node in order:
             # Maker sure we don't use C version of the code, but rather only
             # the python version
+            old_value = node.op._op_use_c_code
+            try:
                 node.op._op_use_c_code = False
                 thunks += [node.op.make_thunk(node,
                                     storage_map,
                                     compute_map,
                                     no_recycling)]
+            finally:
+                node.op._op_use_c_code = old_value
 
         computed, last_user = gc_helper(order)
         if self.allow_gc: