From 0539e82bab014b24b956752cc4301b1cba8edc0f Mon Sep 17 00:00:00 2001
From: Melody Horn <melody@boringcactus.com>
Date: Mon, 5 Apr 2021 12:08:46 -0600
Subject: warn when expanding undefined macro

---
 src/makefile/macro.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/makefile/macro.rs b/src/makefile/macro.rs
index 4d58e07..f62d21d 100644
--- a/src/makefile/macro.rs
+++ b/src/makefile/macro.rs
@@ -113,7 +113,10 @@ impl<'parent, 'lookup> Set<'parent, 'lookup> {
                         self.lookup_internal(name)?
                     } else {
                         self.get(name).map_or_else(
-                            || Ok(String::new()),
+                            || {
+                                log::warn!("undefined macro {}", name);
+                                Ok(String::new())
+                            },
                             |(_, macro_value)| self.expand(macro_value),
                         )?
                     };
-- 
cgit v1.2.3