only print LEAK REPORT if there is a leak

diff --git a/src/librustc_mir/interpret/memory.rs b/src/librustc_mir/interpret/memory.rs
index dc8b035f43afdcf22532da98e25fed902def7530..eccdc5b03261b8dbbe8f47ba040d1b434e2cb09c 100644 (file)
--- a/src/librustc_mir/interpret/memory.rs
+++ b/src/librustc_mir/interpret/memory.rs
@@ -752,12 +752,14 @@ pub fn dump_allocs(&self, mut allocs: Vec<AllocId>) {
     }
 
     pub fn leak_report(&self) -> usize {
-        eprintln!("### LEAK REPORT ###");
         let leaks: Vec<_> = self.alloc_map.filter_map_collect(|&id, &(kind, _)| {
             if kind.may_leak() { None } else { Some(id) }
         });
         let n = leaks.len();
-        self.dump_allocs(leaks);
+        if n > 0 {
+            eprintln!("### LEAK REPORT ###");
+            self.dump_allocs(leaks);
+        }
         n
     }