# HG changeset patch
# User Martin von Zweigbergk <martinvonz@google.com>
# Date 2017-01-13 18:11:37
# Node ID df5d3734b3dfb8bfc7e1d11c5e39f53c5345da8f
# Parent  8614546154cbffe8df6a56d53e404491fa092636

check-code: reject module-level @cachefunc

Module-level @cachefunc usage is risky because it can easily create a
memory "leak". Let's reject it completely for now. If a valid usage
comes up in the future, we can always improve the check or reconsider.

diff --git a/contrib/check-code.py b/contrib/check-code.py
--- a/contrib/check-code.py
+++ b/contrib/check-code.py
@@ -325,6 +325,7 @@ pypats = [
     # XXX only catch mutable arguments on the first line of the definition
     (r'def.*[( ]\w+=\{\}', "don't use mutable default arguments"),
     (r'\butil\.Abort\b', "directly use error.Abort"),
+    (r'^@(\w*\.)?cachefunc', "module-level @cachefunc is risky, please avoid"),
     (r'^import Queue', "don't use Queue, use util.queue + util.empty"),
     (r'^import cStringIO', "don't use cStringIO.StringIO, use util.stringio"),
     (r'^import urllib', "don't use urllib, use util.urlreq/util.urlerr"),