Ensure that macro resolutions in trait positions get finalized.

src/librustc_resolve/lib.rs

@@ -922,6 +922,10 @@ impl<'a> ModuleData<'a> {
     fn is_local(&self) -> bool {
         self.normal_ancestor_id.is_local()
     }
+
+    fn nearest_item_scope(&'a self) -> Module<'a> {
+        if self.is_trait() { self.parent.unwrap() } else { self }
+    }
 }
 
 impl<'a> fmt::Debug for ModuleData<'a> {

src/librustc_resolve/macros.rs

@@ -172,7 +172,6 @@ impl<'a> base::Resolver for Resolver<'a> {
             expansion: mark,
         };
         expansion.visit_with(&mut visitor);
-        self.current_module.unresolved_invocations.borrow_mut().remove(&mark);
         invocation.expansion.set(visitor.legacy_scope);
     }
 
@@ -390,7 +389,7 @@ impl<'a> Resolver<'a> {
                     Err(Determinacy::Determined)
                 },
             };
-            self.current_module.macro_resolutions.borrow_mut()
+            self.current_module.nearest_item_scope().macro_resolutions.borrow_mut()
                 .push((path.into_boxed_slice(), span));
             return def;
         }
@@ -410,7 +409,7 @@ impl<'a> Resolver<'a> {
             }
         };
 
-        self.current_module.legacy_macro_resolutions.borrow_mut()
+        self.current_module.nearest_item_scope().legacy_macro_resolutions.borrow_mut()
             .push((scope, path[0], span, kind));
 
         result

src/test/compile-fail/issue-40845.rs

@@ -0,0 +1,16 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+trait T { m!(); } //~ ERROR cannot find macro `m!` in this scope
+
+struct S;
+impl S { m!(); } //~ ERROR cannot find macro `m!` in this scope
+
+fn main() {}