1 files changed, 213 insertions, 0 deletions
diff --git a/src/test/ui/generic-associated-types/self-outlives-lint.rs b/src/test/ui/generic-associated-types/self-outlives-lint.rs
new file mode 100644
index 000000000..300907adb
--- /dev/null
+++ b/src/test/ui/generic-associated-types/self-outlives-lint.rs
@@ -0,0 +1,213 @@
+#![feature(generic_associated_types)]
+
+// check-fail
+
+use std::fmt::Debug;
+
+// We have a `&'a self`, so we need a `Self: 'a`
+trait Iterable {
+    type Item<'x>;
+    //~^ missing required
+    fn iter<'a>(&'a self) -> Self::Item<'a>;
+}
+
+/*
+impl<T> Iterable for T {
+    type Item<'a> = &'a T;
+    fn iter<'a>(&'a self) -> Self::Item<'a> {
+        self
+    }
+}
+*/
+
+// We have a `&'a T`, so we need a `T: 'x`
+trait Deserializer<T> {
+    type Out<'x>;
+    //~^ missing required
+    fn deserialize<'a>(&self, input: &'a T) -> Self::Out<'a>;
+}
+
+/*
+impl<T> Deserializer<T> for () {
+    type Out<'a> = &'a T;
+    fn deserialize<'a>(&self, input: &'a T) -> Self::Out<'a> { input }
+}
+*/
+
+// We have a `&'b T` and a `'b: 'a`, so it is implied that `T: 'a`. Therefore, we need a `T: 'x`
+trait Deserializer2<T> {
+    type Out<'x>;
+    //~^ missing required
+    fn deserialize2<'a, 'b: 'a>(&self, input1: &'b T) -> Self::Out<'a>;
+}
+
+// We have a `&'a T` and a `&'b U`, so we need a `T: 'x` and a `U: 'y`
+trait Deserializer3<T, U> {
+    type Out<'x, 'y>;
+    //~^ missing required
+    fn deserialize2<'a, 'b>(&self, input: &'a T, input2: &'b U) -> Self::Out<'a, 'b>;
+}
+
+// `T` is a param on the function, so it can't be named by the associated type
+trait Deserializer4 {
+    type Out<'x>;
+    fn deserialize<'a, T>(&self, input: &'a T) -> Self::Out<'a>;
+}
+
+struct Wrap<T>(T);
+
+// We pass `Wrap<T>` and we see `&'z Wrap<T>`, so we require `D: 'x`
+trait Des {
+    type Out<'x, D>;
+    //~^ missing required
+    fn des<'z, T>(&self, data: &'z Wrap<T>) -> Self::Out<'z, Wrap<T>>;
+}
+/*
+impl Des for () {
+    type Out<'x, D> = &'x D; // Not okay
+    fn des<'a, T>(&self, data: &'a Wrap<T>) -> Self::Out<'a, Wrap<T>> {
+        data
+    }
+}
+*/
+
+// We have `T` and `'z` as GAT substs. Because of `&'z Wrap<T>`, there is an
+// implied bound that `T: 'z`, so we require `D: 'x`
+trait Des2 {
+    type Out<'x, D>;
+    //~^ missing required
+    fn des<'z, T>(&self, data: &'z Wrap<T>) -> Self::Out<'z, T>;
+}
+/*
+impl Des2 for () {
+    type Out<'x, D> = &'x D;
+    fn des<'a, T>(&self, data: &'a Wrap<T>) -> Self::Out<'a, T> {
+        &data.0
+    }
+}
+*/
+
+// We see `&'z T`, so we require `D: 'x`
+trait Des3 {
+    type Out<'x, D>;
+    //~^ missing required
+    fn des<'z, T>(&self, data: &'z T) -> Self::Out<'z, T>;
+}
+/*
+impl Des3 for () {
+    type Out<'x, D> = &'x D;
+    fn des<'a, T>(&self, data: &'a T) -> Self::Out<'a, T> {
+          data
+    }
+}
+*/
+
+// Similar case to before, except with GAT.
+trait NoGat<'a> {
+    type Bar;
+    fn method(&'a self) -> Self::Bar;
+}
+
+// Lifetime is not on function; except `Self: 'a`
+// FIXME: we require two bounds (`where Self: 'a, Self: 'b`) when we should only require one
+trait TraitLifetime<'a> {
+    type Bar<'b>;
+    //~^ missing required
+    fn method(&'a self) -> Self::Bar<'a>;
+}
+
+// Like above, but we have a where clause that can prove what we want
+// FIXME: we require two bounds (`where Self: 'a, Self: 'b`) when we should only require one
+trait TraitLifetimeWhere<'a> where Self: 'a {
+    type Bar<'b>;
+    //~^ missing required
+    fn method(&'a self) -> Self::Bar<'a>;
+}
+
+// Explicit bound instead of implicit; we want to still error
+trait ExplicitBound {
+    type Bar<'b>;
+    //~^ missing required
+    fn method<'b>(&self, token: &'b ()) -> Self::Bar<'b> where Self: 'b;
+}
+
+// The use of the GAT here is not in the return, we don't want to error
+trait NotInReturn {
+    type Bar<'b>;
+    fn method<'b>(&'b self) where Self::Bar<'b>: Debug;
+}
+
+// We obviously error for `Iterator`, but we should also error for `Item`
+trait IterableTwo {
+    type Item<'a>;
+    //~^ missing required
+    type Iterator<'a>: Iterator<Item = Self::Item<'a>>;
+    //~^ missing required
+    fn iter<'a>(&'a self) -> Self::Iterator<'a>;
+}
+
+trait IterableTwoWhere {
+    type Item<'a>;
+    //~^ missing required
+    type Iterator<'a>: Iterator<Item = Self::Item<'a>> where Self: 'a;
+    fn iter<'a>(&'a self) -> Self::Iterator<'a>;
+}
+
+// We also should report region outlives clauses. Here, we know that `'y: 'x`,
+// because of `&'x &'y`, so we require that `'b: 'a`.
+trait RegionOutlives {
+    type Bar<'a, 'b>;
+    //~^ missing required
+    fn foo<'x, 'y>(&self, input: &'x &'y ()) -> Self::Bar<'x, 'y>;
+}
+
+/*
+impl Foo for () {
+    type Bar<'a, 'b> = &'a &'b ();
+    fn foo<'x, 'y>(&self, input: &'x &'y ()) -> Self::Bar<'x, 'y> {
+        input
+    }
+}
+*/
+
+// Similar to the above, except with explicit bounds
+trait ExplicitRegionOutlives<'ctx> {
+    type Fut<'out>;
+    //~^ missing required
+
+    fn test<'out>(ctx: &'ctx i32) -> Self::Fut<'out>
+    where
+        'ctx: 'out;
+}
+
+
+// If there are multiple methods that return the GAT, require a set of clauses
+// that can be satisfied by *all* methods
+trait MultipleMethods {
+    type Bar<'me>;
+
+    fn gimme<'a>(&'a self) -> Self::Bar<'a>;
+    fn gimme_default(&self) -> Self::Bar<'static>;
+}
+
+// We would normally require `Self: 'a`, but we can prove that `Self: 'static`
+// because of the the bounds on the trait, so the bound is proven
+trait Trait: 'static {
+    type Assoc<'a>;
+    fn make_assoc(_: &u32) -> Self::Assoc<'_>;
+}
+
+// We ignore `'static` lifetimes for any lints
+trait StaticReturn<'a> {
+    type Y<'b>;
+    fn foo(&self) -> Self::Y<'static>;
+}
+
+// Same as above, but with extra method that takes GAT - just make sure this works
+trait StaticReturnAndTakes<'a> {
+    type Y<'b>;
+    fn foo(&self) -> Self::Y<'static>;
+    fn bar<'b>(&self, arg: Self::Y<'b>);
+}
+
+fn main() {}