---

yaml
---
r: 118309
b: refs/heads/try
c: 862cd65
h: refs/heads/master
i:
  118307: 8d0091a
v: v3

Author: sfackler

[refs]

@@ -2,7 +2,7 @@
 refs/heads/master: 3770c42a4959cbabc73da52abc7e3db96657974e
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: d6736a1440d42f6af967a8a20ab8d73522112b72
-refs/heads/try: 42a18bd985e103484abbe801082b0593f1a43019
+refs/heads/try: 862cd65dcadf34b5ab59063be151ab801fc7bfe1
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
 refs/heads/try2: 147ecfdd8221e4a4d4e090486829a06da1e0ca3c

branches/try/src/librustc/middle/lint.rs

@@ -1124,6 +1124,20 @@ fn check_unused_attribute(cx: &Context, attr: &ast::Attribute) {
         "unstable",
     ];
 
+    static CRATE_ATTRS: &'static [&'static str] = &'static [
+        "crate_type",
+        "feature",
+        "no_start",
+        "no_main",
+        "no_std",
+        "crate_id",
+        "desc",
+        "comment",
+        "license",
+        "copyright",
+        "no_builtins",
+    ];
+
     for &name in ATTRIBUTE_WHITELIST.iter() {
         if attr.check_name(name) {
             break;
@@ -1132,6 +1146,15 @@ fn check_unused_attribute(cx: &Context, attr: &ast::Attribute) {
 
     if !attr::is_used(attr) {
         cx.span_lint(UnusedAttribute, attr.span, "unused attribute");
+        if CRATE_ATTRS.contains(&attr.name().get()) {
+            let msg = match attr.node.style {
+                ast::AttrOuter => "crate-level attribute should be an inner \
+                                  attribute: add an exclamation mark: #![foo]",
+                ast::AttrInner => "crate-level attribute should be in the \
+                                   root module",
+            };
+            cx.span_lint(UnusedAttribute, attr.span, msg);
+        }
     }
 }
 

branches/try/src/test/compile-fail/lint-misplaced-attr.rs

@@ -15,6 +15,8 @@
 
 mod a {
     #![crate_type = "bin"] //~ ERROR unused attribute
+                           //~^ ERROR should be in the root module
 }
 
 #[crate_type = "bin"] fn main() {} //~ ERROR unused attribute
+                                   //~^ ERROR should be an inner