diff --git a/tools/build_rules/empty_main.bzl b/tools/build_rules/empty_main.bzl
new file mode 100644
index 0000000..050907c
--- /dev/null
+++ b/tools/build_rules/empty_main.bzl
@@ -0,0 +1,5 @@
+'''Returns a select which is either srcs or an empty main function.'''
+def empty_main_if_asan(srcs):
+  return select({
+    '//conditions:default': srcs,
+  })