Flesh out tests more

tests/ui/borrowck/alias-liveness/gat-static.rs

@@ -8,7 +8,7 @@ trait Foo {
     fn assoc(&mut self) -> Self::Assoc<'_>;
 }
 
-fn test<T>(mut t: T)
+fn overlapping_mut<T>(mut t: T)
 where
     T: Foo,
     for<'a> T::Assoc<'a>: 'static,
@@ -17,4 +17,13 @@ where
     let b = t.assoc();
 }
 
+fn live_past_borrow<T>(mut t: T)
+where
+    T: Foo,
+    for<'a> T::Assoc<'a>: 'static {
+    let x = t.assoc();
+    drop(t);
+    drop(x);
+}
+
 fn main() {}

tests/ui/borrowck/alias-liveness/higher-ranked-outlives-for-capture.rs

@@ -0,0 +1,16 @@
+// known-bug: #42940
+
+trait Captures<'a> {}
+impl<T> Captures<'_> for T {}
+
+trait Outlives<'a>: 'a {}
+impl<'a, T: 'a> Outlives<'a> for T {}
+
+// Test that we treat `for<'a> Opaque: 'a` as `Opaque: 'static`
+fn test<'o>(v: &'o Vec<i32>) -> impl Captures<'o> + for<'a> Outlives<'a> {}
+
+fn statik() -> impl Sized {
+    test(&vec![])
+}
+
+fn main() {}

tests/ui/borrowck/alias-liveness/higher-ranked-outlives-for-capture.stderr

@@ -0,0 +1,16 @@
+error[E0716]: temporary value dropped while borrowed
+  --> $DIR/higher-ranked-outlives-for-capture.rs:13:11
+   |
+LL |     test(&vec![])
+   |     ------^^^^^^-
+   |     |     |
+   |     |     creates a temporary value which is freed while still in use
+   |     argument requires that borrow lasts for `'static`
+LL | }
+   | - temporary value is freed at the end of this statement
+   |
+   = note: this error originates in the macro `vec` (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0716`.

tests/ui/borrowck/alias-liveness/higher-ranked.rs

@@ -0,0 +1,16 @@
+// check-pass
+
+trait Captures<'a> {}
+impl<T> Captures<'_> for T {}
+
+trait Outlives<'a>: 'a {}
+impl<'a, T: 'a> Outlives<'a> for T {}
+
+// Test that we treat `for<'a> Opaque: 'a` as `Opaque: 'static`
+fn test<'o>(v: &'o Vec<i32>) -> impl Captures<'o> + for<'a> Outlives<'a> {}
+
+fn opaque_doesnt_use_temporary() {
+    let a = test(&vec![]);
+}
+
+fn main() {}

tests/ui/borrowck/alias-liveness/opaque-capture.rs

@@ -0,0 +1,17 @@
+// check-pass
+
+// Check that opaques capturing early and late-bound vars correctly mark
+// regions required to be live using the item bounds.
+
+trait Captures<'a> {}
+impl<T> Captures<'_> for T {}
+
+fn captures_temp_late<'a>(x: &'a Vec<i32>) -> impl Sized + Captures<'a> + 'static {}
+fn captures_temp_early<'a: 'a>(x: &'a Vec<i32>) -> impl Sized + Captures<'a> + 'static {}
+
+fn test() {
+    let x = captures_temp_early(&vec![]);
+    let y = captures_temp_late(&vec![]);
+}
+
+fn main() {}

tests/ui/borrowck/alias-liveness/opaque-type-param.rs

@@ -0,0 +1,14 @@
+// known-bug: #42940
+
+trait Trait {}
+impl Trait for () {}
+
+fn foo<'a>(s: &'a str) -> impl Trait + 'static {
+    bar(s)
+}
+
+fn bar<P: AsRef<str>>(s: P) -> impl Trait + 'static {
+    ()
+}
+
+fn main() {}

tests/ui/borrowck/alias-liveness/opaque-type-param.stderr

@@ -0,0 +1,13 @@
+error[E0700]: hidden type for `impl Trait + 'static` captures lifetime that does not appear in bounds
+  --> $DIR/opaque-type-param.rs:7:5
+   |
+LL | fn foo<'a>(s: &'a str) -> impl Trait + 'static {
+   |        --                 -------------------- opaque type defined here
+   |        |
+   |        hidden type `impl Trait + 'static` captures the lifetime `'a` as defined here
+LL |     bar(s)
+   |     ^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0700`.

tests/ui/borrowck/alias-liveness/rpit-static.rs

@@ -3,12 +3,20 @@
 trait Captures<'a> {}
 impl<T> Captures<'_> for T {}
 
-fn foo(x: &i32) -> impl Sized + Captures<'_> + 'static {}
+fn foo(x: &mut i32) -> impl Sized + Captures<'_> + 'static {}
 
-fn main() {
+fn overlapping_mut() {
+    let i = &mut 1;
+    let x = foo(i);
+    let y = foo(i);
+}
+
+fn live_past_borrow() {
     let y;
     {
-        let x = 1;
-        y = foo(&x);
+        let x = &mut 1;
+        y = foo(x);
     }
 }
+
+fn main() {}

tests/ui/borrowck/alias-liveness/rpitit-static.rs

@@ -4,7 +4,13 @@ trait Foo {
     fn rpitit(&mut self) -> impl Sized + 'static;
 }
 
-fn test<T: Foo>(mut t: T) {
+fn live_past_borrow<T: Foo>(mut t: T) {
+    let x = t.rpitit();
+    drop(t);
+    drop(x);
+}
+
+fn overlapping_mut<T: Foo>(mut t: T) {
     let a = t.rpitit();
     let b = t.rpitit();
 }

tests/ui/borrowck/alias-liveness/rtn-static.rs

@@ -7,9 +7,15 @@ trait Foo {
     fn borrow(&mut self) -> impl Sized + '_;
 }
 
+fn live_past_borrow<T: Foo<borrow(): 'static>>(mut t: T) {
+    let x = t.borrow();
+    drop(t);
+    drop(x);
+}
+
 // Test that the `'_` item bound in `borrow` does not cause us to
 // overlook the `'static` RTN bound.
-fn test<T: Foo<borrow(): 'static>>(mut t: T) {
+fn overlapping_mut<T: Foo<borrow(): 'static>>(mut t: T) {
     let x = t.borrow();
     let x = t.borrow();
 }

tests/ui/impl-trait/bivariant-lifetime-liveness.rs

@@ -0,0 +1,15 @@
+// check-pass
+// issue: 116794
+
+// Uncaptured lifetimes should not be required to be live.
+
+struct Invariant<T>(*mut T);
+
+fn opaque<'a: 'a>(_: &'a str) -> Invariant<impl Sized> {
+    Invariant(&mut ())
+}
+
+fn main() {
+    let x = opaque(&String::new());
+    drop(x);
+}