From df726a45e18a9e760931f867b995f642131180ad Mon Sep 17 00:00:00 2001
From: Vincent Prouillet <vincent@wearewizards.io>
Date: Thu, 4 Aug 2016 20:27:11 +0100
Subject: [PATCH] Update error format for E0137

---
 src/librustc/middle/entry.rs   | 7 +++++--
 src/test/compile-fail/E0137.rs | 6 ++++--
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/librustc/middle/entry.rs b/src/librustc/middle/entry.rs
index 23a261400ed07..0a363fddd5312 100644
--- a/src/librustc/middle/entry.rs
+++ b/src/librustc/middle/entry.rs
@@ -121,8 +121,11 @@ fn find_item(item: &Item, ctxt: &mut EntryContext, at_root: bool) {
             if ctxt.attr_main_fn.is_none() {
                 ctxt.attr_main_fn = Some((item.id, item.span));
             } else {
-                span_err!(ctxt.session, item.span, E0137,
-                          "multiple functions with a #[main] attribute");
+                struct_span_err!(ctxt.session, item.span, E0137,
+                          "multiple functions with a #[main] attribute")
+                .span_label(item.span, &format!("additional #[main] function"))
+                .span_label(ctxt.attr_main_fn.unwrap().1, &format!("first #[main] function"))
+                .emit();
             }
         },
         EntryPointType::Start => {
diff --git a/src/test/compile-fail/E0137.rs b/src/test/compile-fail/E0137.rs
index 695ce7995a9a4..f45afc9f37bd5 100644
--- a/src/test/compile-fail/E0137.rs
+++ b/src/test/compile-fail/E0137.rs
@@ -11,7 +11,9 @@
 #![feature(main)]
 
 #[main]
-fn foo() {}
+fn foo() {} //~ NOTE first #[main] function
 
 #[main]
-fn f() {} //~ ERROR E0137
+fn f() {}
+//~^ ERROR E0137
+//~| NOTE additional #[main] function