fix lifetime shadowing check in GATs

rust-lang · Feb 7, 2020 · 953f6ec · 953f6ec
1 parent b5e21db
commit 953f6ec
Show file tree

Hide file tree

Showing 3 changed files with 25 additions and 6 deletions.
diff --git a/src/librustc_resolve/lifetimes.rs b/src/librustc_resolve/lifetimes.rs
@@ -747,7 +747,8 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
  track_lifetime_uses: true,
  opaque_type_parent: true,
  };
- self.with(scope, |_old_scope, this| {
+ self.with(scope, |old_scope, this| {
+ this.check_lifetime_params(old_scope, &generics.params);
  this.visit_generics(generics);
  for bound in bounds {
  this.visit_param_bound(bound);
@@ -804,7 +805,8 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
  track_lifetime_uses: true,
  opaque_type_parent: true,
  };
- self.with(scope, |_old_scope, this| {
+ self.with(scope, |old_scope, this| {
+ this.check_lifetime_params(old_scope, &generics.params);
  this.visit_generics(generics);
  this.visit_ty(ty);
  });

diff --git a/src/test/ui/generic-associated-types/shadowing.rs b/src/test/ui/generic-associated-types/shadowing.rs
@@ -2,17 +2,17 @@
 #![feature(generic_associated_types)]
 
 trait Shadow<'a> {
- //FIXME(#44265): The lifetime parameter shadowing should cause an error.
  type Bar<'a>;
+ //~^ ERROR lifetime name `'a` shadows a lifetime name that is already in scope
 }
 
 trait NoShadow<'a> {
  type Bar<'b>; // OK
 }
 
 impl<'a> NoShadow<'a> for &'a u32 {
- //FIXME(#44265): The lifetime parameter shadowing should cause an error.
  type Bar<'a> = i32;
+ //~^ ERROR lifetime name `'a` shadows a lifetime name that is already in scope
 }
 
 trait ShadowT<T> {

diff --git a/src/test/ui/generic-associated-types/shadowing.stderr b/src/test/ui/generic-associated-types/shadowing.stderr
@@ -14,6 +14,22 @@ LL | impl<T> NoShadowT<T> for Option<T> {
 LL | type Bar<T> = i32;
  | ^ already used
 
+error[E0496]: lifetime name `'a` shadows a lifetime name that is already in scope
+ --> $DIR/shadowing.rs:5:14
+ |
+LL | trait Shadow<'a> {
+ | -- first declared here
+LL | type Bar<'a>;
+ | ^^ lifetime 'a already in scope
+
+error[E0496]: lifetime name `'a` shadows a lifetime name that is already in scope
+ --> $DIR/shadowing.rs:14:14
+ |
+LL | impl<'a> NoShadow<'a> for &'a u32 {
+ | -- first declared here
+LL | type Bar<'a> = i32;
+ | ^^ lifetime 'a already in scope
+
 error: type-generic associated types are not yet implemented
  --> $DIR/shadowing.rs:19:5
  |
@@ -30,6 +46,7 @@ LL | type Bar<U>; // OK
  |
  = note: for more information, see https://github.com/rust-lang/rust/issues/44265
 
-error: aborting due to 4 previous errors
+error: aborting due to 6 previous errors
 
-For more information about this error, try `rustc --explain E0403`.
+Some errors have detailed explanations: E0403, E0496.
+For more information about an error, try `rustc --explain E0403`.