Auto merge of #44782 - estebank:issue-36700, r=GuillaumeGomez

Point at parameter type on E0301

On "the parameter type `T` may not live long enough" error, point to the
parameter type suggesting lifetime bindings:

```
error[E0310]: the parameter type `T` may not live long enough
  --> $DIR/lifetime-doesnt-live-long-enough.rs:28:5
   |
27 | struct Foo<T> {
   |            - help: consider adding an explicit lifetime bound `T: 'static`...
28 |     foo: &'static T
   |     ^^^^^^^^^^^^^^^
   |
note: ...so that the reference type `&'static T` does not outlive the data it points at
  --> $DIR/lifetime-doesnt-live-long-enough.rs:28:5
   |
28 |     foo: &'static T
   |     ^^^^^^^^^^^^^^^
```

Fix #36700.

2 files changed, 61 insertions, 0 deletions

diff --git a/src/test/ui/lifetimes/lifetime-doesnt-live-long-enough.rs b/src/test/ui/lifetimes/lifetime-doesnt-live-long-enough.rs
new file mode 100644
index 00000000000..465b4271035
--- /dev/null
+++ b/src/test/ui/lifetimes/lifetime-doesnt-live-long-enough.rs
@@ -0,0 +1,31 @@
+// Copyright 2014 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 ListItem<'a> {
+    fn list_name() -> &'a str;
+}
+
+trait Collection { fn len(&self) -> usize; }
+
+struct List<'a, T: ListItem<'a>> {
+    slice: &'a [T]
+}
+
+impl<'a, T: ListItem<'a>> Collection for List<'a, T> {
+    fn len(&self) -> usize {
+        0
+    }
+}
+
+struct Foo<T> {
+    foo: &'static T
+}
+
+fn main() {}
diff --git a/src/test/ui/lifetimes/lifetime-doesnt-live-long-enough.stderr b/src/test/ui/lifetimes/lifetime-doesnt-live-long-enough.stderr
new file mode 100644
index 00000000000..e17a660c591
--- /dev/null
+++ b/src/test/ui/lifetimes/lifetime-doesnt-live-long-enough.stderr
@@ -0,0 +1,30 @@
+error[E0309]: the parameter type `T` may not live long enough
+  --> $DIR/lifetime-doesnt-live-long-enough.rs:18:5
+   |
+17 | struct List<'a, T: ListItem<'a>> {
+   |                 -- help: consider adding an explicit lifetime bound `T: 'a`...
+18 |     slice: &'a [T]
+   |     ^^^^^^^^^^^^^^
+   |
+note: ...so that the reference type `&'a [T]` does not outlive the data it points at
+  --> $DIR/lifetime-doesnt-live-long-enough.rs:18:5
+   |
+18 |     slice: &'a [T]
+   |     ^^^^^^^^^^^^^^
+
+error[E0310]: the parameter type `T` may not live long enough
+  --> $DIR/lifetime-doesnt-live-long-enough.rs:28:5
+   |
+27 | struct Foo<T> {
+   |            - help: consider adding an explicit lifetime bound `T: 'static`...
+28 |     foo: &'static T
+   |     ^^^^^^^^^^^^^^^
+   |
+note: ...so that the reference type `&'static T` does not outlive the data it points at
+  --> $DIR/lifetime-doesnt-live-long-enough.rs:28:5
+   |
+28 |     foo: &'static T
+   |     ^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+