1 files changed, 10 insertions, 0 deletions
diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index 5d7581c8211..9203a558f64 100644
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -1320,3 +1320,13 @@ impl Compiler {
         self.stage >= final_stage
     }
 }
+
+fn envify(s: &str) -> String {
+    s.chars()
+        .map(|c| match c {
+            '-' => '_',
+            c => c,
+        })
+        .flat_map(|c| c.to_uppercase())
+        .collect()
+}