Convert lifetime shadowing into a hard error, as promised.

src/librustc/middle/resolve_lifetime.rs

@@ -507,7 +507,7 @@ impl<'a> LifetimeContext<'a> {
                 EarlyScope(_, lifetimes, s) |
                 LateScope(lifetimes, s) => {
                     if let Some((_, lifetime_def)) = search_lifetimes(lifetimes, lifetime) {
-                        self.sess.span_warn(
+                        self.sess.span_err(
                             lifetime.span,
                             &format!("lifetime name `{}` shadows another \
                                      lifetime name that is already in scope",
@@ -516,10 +516,6 @@ impl<'a> LifetimeContext<'a> {
                             lifetime_def.span,
                             &format!("shadowed lifetime `{}` declared here",
                                      token::get_name(lifetime.name)));
-                        self.sess.span_note(
-                            lifetime.span,
-                            "shadowed lifetimes are deprecated \
-                             and will become a hard error before 1.0");
                         return;
                     }
 

src/test/compile-fail/shadowed-lifetime.rs

@@ -15,16 +15,14 @@ struct Foo<'a>(&'a isize);
 impl<'a> Foo<'a> {
     //~^ NOTE shadowed lifetime `'a` declared here
     fn shadow_in_method<'a>(&'a self) -> &'a isize {
-        //~^ WARNING lifetime name `'a` shadows another lifetime name that is already in scope
-        //~| NOTE deprecated
+        //~^ ERROR lifetime name `'a` shadows another lifetime name that is already in scope
         self.0
     }
 
     fn shadow_in_type<'b>(&'b self) -> &'b isize {
         //~^ NOTE shadowed lifetime `'b` declared here
         let x: for<'b> fn(&'b isize) = panic!();
-        //~^ WARNING lifetime name `'b` shadows another lifetime name that is already in scope
-        //~| NOTE deprecated
+        //~^ ERROR lifetime name `'b` shadows another lifetime name that is already in scope
         self.0
     }
 
@@ -35,9 +33,4 @@ impl<'a> Foo<'a> {
 }
 
 fn main() {
-    // intentional error that occurs after `resolve_lifetime` runs,
-    // just to ensure that this test fails to compile; when shadowed
-    // lifetimes become either an error or a proper lint, this will
-    // not be needed.
-    let x: isize = 3_usize; //~ ERROR mismatched types
 }

src/test/run-pass/overloaded-index-assoc-list.rs

@@ -35,7 +35,7 @@ impl<K,V> AssociationList<K,V> {
 impl<'a, K: PartialEq + std::fmt::Debug, V:Clone> Index<&'a K> for AssociationList<K,V> {
     type Output = V;
 
-    fn index<'a>(&'a self, index: &K) -> &'a V {
+    fn index(&self, index: &K) -> &V {
         for pair in &self.pairs {
             if pair.key == *index {
                 return &pair.value