Auto merge of #98109 - nikomatsakis:issue-98095, r=jackh726

fix universes in the NLL type tests

In the NLL code, we were not accommodating universes in the
`type_test` logic.

Fixes #98095.

r? `@compiler-errors`

This breaks some tests, however, so the purpose of this branch is more explanatory and perhaps to do a crater run.

20 files changed, 280 insertions, 146 deletions

diff --git a/src/test/ui/borrowck/issue-71546.rs b/src/test/ui/borrowck/issue-71546.rs
index b20c39193de..42100edeaa7 100644
--- a/src/test/ui/borrowck/issue-71546.rs
+++ b/src/test/ui/borrowck/issue-71546.rs
@@ -1,4 +1,8 @@
 // Regression test for #71546.
+//
+// Made to pass as part of fixing #98095.
+//
+// check-pass
 
 pub fn serialize_as_csv<V>(value: &V) -> Result<String, &str>
 where
@@ -6,15 +10,7 @@ where
     for<'a> &'a V: IntoIterator,
     for<'a> <&'a V as IntoIterator>::Item: ToString + 'static,
 {
-    let csv_str: String = value
-        //~^ ERROR higher-ranked lifetime error
-        //~| ERROR higher-ranked lifetime error
-        //~| ERROR higher-ranked lifetime error
-        .into_iter()
-        .map(|elem| elem.to_string())
-        //~^ ERROR higher-ranked lifetime error
-        .collect::<String>();
-        //~^ ERROR higher-ranked lifetime error
+    let csv_str: String = value.into_iter().map(|elem| elem.to_string()).collect::<String>();
     Ok(csv_str)
 }
 
diff --git a/src/test/ui/borrowck/issue-71546.stderr b/src/test/ui/borrowck/issue-71546.stderr
deleted file mode 100644
index b8d79f0939b..00000000000
--- a/src/test/ui/borrowck/issue-71546.stderr
+++ /dev/null
@@ -1,59 +0,0 @@
-error: higher-ranked lifetime error
-  --> $DIR/issue-71546.rs:9:27
-   |
-LL |       let csv_str: String = value
-   |  ___________________________^
-LL | |
-LL | |
-LL | |
-LL | |         .into_iter()
-LL | |         .map(|elem| elem.to_string())
-   | |_____________________________________^
-   |
-   = note: could not prove for<'r> [closure@$DIR/issue-71546.rs:14:14: 14:37] well-formed
-
-error: higher-ranked lifetime error
-  --> $DIR/issue-71546.rs:9:27
-   |
-LL |       let csv_str: String = value
-   |  ___________________________^
-LL | |
-LL | |
-LL | |
-LL | |         .into_iter()
-LL | |         .map(|elem| elem.to_string())
-   | |_____________________________________^
-   |
-   = note: could not prove for<'r, 's> Map<<&'r V as IntoIterator>::IntoIter, [closure@$DIR/issue-71546.rs:14:14: 14:37]> well-formed
-
-error: higher-ranked lifetime error
-  --> $DIR/issue-71546.rs:9:27
-   |
-LL |       let csv_str: String = value
-   |  ___________________________^
-LL | |
-LL | |
-LL | |
-...  |
-LL | |
-LL | |         .collect::<String>();
-   | |____________________________^
-   |
-   = note: could not prove for<'r, 's> Map<<&'r V as IntoIterator>::IntoIter, [closure@$DIR/issue-71546.rs:14:14: 14:37]> well-formed
-
-error: higher-ranked lifetime error
-  --> $DIR/issue-71546.rs:14:14
-   |
-LL |         .map(|elem| elem.to_string())
-   |              ^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: could not prove for<'a> <&'a V as IntoIterator>::Item: 'static
-
-error: higher-ranked lifetime error
-  --> $DIR/issue-71546.rs:16:10
-   |
-LL |         .collect::<String>();
-   |          ^^^^^^^
-
-error: aborting due to 5 previous errors
-
diff --git a/src/test/ui/generic-associated-types/collectivity-regression.rs b/src/test/ui/generic-associated-types/collectivity-regression.rs
new file mode 100644
index 00000000000..fb736843907
--- /dev/null
+++ b/src/test/ui/generic-associated-types/collectivity-regression.rs
@@ -0,0 +1,24 @@
+// Regression test from https://github.com/rust-lang/rust/pull/98109
+
+#![feature(generic_associated_types)]
+
+pub trait Get {
+    type Value<'a>
+    where
+        Self: 'a;
+}
+
+fn multiply_at<T>(x: T)
+where
+    for<'a> T: Get<Value<'a> = ()>,
+{
+    || {
+        //~^ `T` does not live long enough
+        //
+        // FIXME(#98437). This regressed at some point and
+        // probably should work.
+        let _x = x;
+    };
+}
+
+fn main() {}
diff --git a/src/test/ui/generic-associated-types/collectivity-regression.stderr b/src/test/ui/generic-associated-types/collectivity-regression.stderr
new file mode 100644
index 00000000000..a858dd7fddc
--- /dev/null
+++ b/src/test/ui/generic-associated-types/collectivity-regression.stderr
@@ -0,0 +1,14 @@
+error: `T` does not live long enough
+  --> $DIR/collectivity-regression.rs:15:5
+   |
+LL | /     || {
+LL | |
+LL | |         //
+LL | |         // FIXME(#98437). This regressed at some point and
+LL | |         // probably should work.
+LL | |         let _x = x;
+LL | |     };
+   | |_____^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/generic-associated-types/issue-86483.rs b/src/test/ui/generic-associated-types/issue-86483.rs
index a8b54c354e3..07dd0bffd46 100644
--- a/src/test/ui/generic-associated-types/issue-86483.rs
+++ b/src/test/ui/generic-associated-types/issue-86483.rs
@@ -1,14 +1,16 @@
 // Regression test of #86483.
+//
+// Made to pass as part of fixing #98095.
+//
+// check-pass
 
 #![feature(generic_associated_types)]
 
-pub trait IceIce<T> //~ ERROR: the parameter type `T` may not live long enough
+pub trait IceIce<T>
 where
     for<'a> T: 'a,
 {
     type Ice<'v>: IntoIterator<Item = &'v T>;
-    //~^ ERROR: the parameter type `T` may not live long enough
-    //~| ERROR: the parameter type `T` may not live long enough
 }
 
 fn main() {}
diff --git a/src/test/ui/generic-associated-types/issue-86483.stderr b/src/test/ui/generic-associated-types/issue-86483.stderr
deleted file mode 100644
index a13dc043dc5..00000000000
--- a/src/test/ui/generic-associated-types/issue-86483.stderr
+++ /dev/null
@@ -1,50 +0,0 @@
-error[E0311]: the parameter type `T` may not live long enough
-  --> $DIR/issue-86483.rs:5:1
-   |
-LL | / pub trait IceIce<T>
-LL | | where
-LL | |     for<'a> T: 'a,
-LL | | {
-...  |
-LL | |
-LL | | }
-   | |_^
-   |
-   = note: ...so that the type `T` will meet its required lifetime bounds...
-note: ...that is required by this bound
-  --> $DIR/issue-86483.rs:7:16
-   |
-LL |     for<'a> T: 'a,
-   |                ^^
-help: consider adding an explicit lifetime bound...
-   |
-LL |     for<'a> T: 'a + 'a,
-   |                   ++++
-
-error[E0311]: the parameter type `T` may not live long enough
-  --> $DIR/issue-86483.rs:9:5
-   |
-LL |     type Ice<'v>: IntoIterator<Item = &'v T>;
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ...so that the type `T` will meet its required lifetime bounds...
-   |
-note: ...that is required by this bound
-  --> $DIR/issue-86483.rs:7:16
-   |
-LL |     for<'a> T: 'a,
-   |                ^^
-help: consider adding an explicit lifetime bound...
-   |
-LL |     for<'a> T: 'a + 'a,
-   |                   ++++
-
-error[E0309]: the parameter type `T` may not live long enough
-  --> $DIR/issue-86483.rs:9:32
-   |
-LL |     type Ice<'v>: IntoIterator<Item = &'v T>;
-   |                                ^^^^^^^^^^^^ - help: consider adding a where clause: `where T: 'v`
-   |                                |
-   |                                ...so that the reference type `&'v T` does not outlive the data it points at
-
-error: aborting due to 3 previous errors
-
-For more information about this error, try `rustc --explain E0309`.
diff --git a/src/test/ui/generic-associated-types/issue-91139.rs b/src/test/ui/generic-associated-types/issue-91139.rs
index 03dc8ef93fe..092fa939c30 100644
--- a/src/test/ui/generic-associated-types/issue-91139.rs
+++ b/src/test/ui/generic-associated-types/issue-91139.rs
@@ -1,5 +1,3 @@
-//check-pass
-
 #![feature(generic_associated_types)]
 
 trait Foo<T> {
@@ -16,6 +14,22 @@ impl<T> Foo<T> for () {
 
 fn foo<T>() {
     let _: for<'a> fn(<() as Foo<T>>::Type<'a>, &'a T) = |_, _| ();
+    //~^ ERROR `T` does not live long enough
+    //~| ERROR `T` does not live long enough
+    //~| ERROR `T` does not live long enough
+    //~| ERROR `T` does not live long enough
+    //~| ERROR `T` does not live long enough
+    //~| ERROR `T` does not live long enough
+    //~| ERROR `T` does not live long enough
+    //~| ERROR `T` does not live long enough
+    //
+    // FIXME: This error is bogus, but it arises because we try to validate
+    // that `<() as Foo<T>>::Type<'a>` is valid, which requires proving
+    // that `T: 'a`. Since `'a` is higher-ranked, this becomes
+    // `for<'a> T: 'a`, which is not true. Of course, the error is bogus
+    // because there *ought* to be an implied bound stating that `'a` is
+    // not any lifetime but specifically
+    // "some `'a` such that `<() as Foo<T>>::Type<'a>" is valid".
 }
 
 pub fn main() {}
diff --git a/src/test/ui/generic-associated-types/issue-91139.stderr b/src/test/ui/generic-associated-types/issue-91139.stderr
new file mode 100644
index 00000000000..6c5092978c8
--- /dev/null
+++ b/src/test/ui/generic-associated-types/issue-91139.stderr
@@ -0,0 +1,50 @@
+error: `T` does not live long enough
+  --> $DIR/issue-91139.rs:16:12
+   |
+LL |     let _: for<'a> fn(<() as Foo<T>>::Type<'a>, &'a T) = |_, _| ();
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: `T` does not live long enough
+  --> $DIR/issue-91139.rs:16:12
+   |
+LL |     let _: for<'a> fn(<() as Foo<T>>::Type<'a>, &'a T) = |_, _| ();
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: `T` does not live long enough
+  --> $DIR/issue-91139.rs:16:12
+   |
+LL |     let _: for<'a> fn(<() as Foo<T>>::Type<'a>, &'a T) = |_, _| ();
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: `T` does not live long enough
+  --> $DIR/issue-91139.rs:16:12
+   |
+LL |     let _: for<'a> fn(<() as Foo<T>>::Type<'a>, &'a T) = |_, _| ();
+   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: `T` does not live long enough
+  --> $DIR/issue-91139.rs:16:58
+   |
+LL |     let _: for<'a> fn(<() as Foo<T>>::Type<'a>, &'a T) = |_, _| ();
+   |                                                          ^^^^^^^^^
+
+error: `T` does not live long enough
+  --> $DIR/issue-91139.rs:16:58
+   |
+LL |     let _: for<'a> fn(<() as Foo<T>>::Type<'a>, &'a T) = |_, _| ();
+   |                                                          ^^^^^^^^^
+
+error: `T` does not live long enough
+  --> $DIR/issue-91139.rs:16:58
+   |
+LL |     let _: for<'a> fn(<() as Foo<T>>::Type<'a>, &'a T) = |_, _| ();
+   |                                                          ^^^^^^^^^
+
+error: `T` does not live long enough
+  --> $DIR/issue-91139.rs:16:58
+   |
+LL |     let _: for<'a> fn(<() as Foo<T>>::Type<'a>, &'a T) = |_, _| ();
+   |                                                          ^^^^^^^^^
+
+error: aborting due to 8 previous errors
+
diff --git a/src/test/ui/generic-associated-types/issue-92096.rs b/src/test/ui/generic-associated-types/issue-92096.rs
index bfe0fc15fd3..377b8164ad5 100644
--- a/src/test/ui/generic-associated-types/issue-92096.rs
+++ b/src/test/ui/generic-associated-types/issue-92096.rs
@@ -1,5 +1,4 @@
 // edition:2018
-// check-pass
 
 #![feature(generic_associated_types)]
 
@@ -18,6 +17,14 @@ where
     C: Client + Send + Sync,
 {
     async move { c.connect().await }
+    //~^ ERROR `C` does not live long enough
+    //
+    // FIXME(#71723). This is because we infer at some point a value of
+    //
+    // impl Future<Output = <C as Client>::Connection<'_>>
+    //
+    // and then we somehow fail the WF check because `where C: 'a` is not known,
+    // but I'm not entirely sure how that comes about.
 }
 
 fn main() {}
diff --git a/src/test/ui/generic-associated-types/issue-92096.stderr b/src/test/ui/generic-associated-types/issue-92096.stderr
new file mode 100644
index 00000000000..ca61a0f435e
--- /dev/null
+++ b/src/test/ui/generic-associated-types/issue-92096.stderr
@@ -0,0 +1,8 @@
+error: `C` does not live long enough
+  --> $DIR/issue-92096.rs:19:5
+   |
+LL |     async move { c.connect().await }
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/higher-rank-trait-bounds/issue-88586-hr-self-outlives-in-trait-def.rs b/src/test/ui/higher-rank-trait-bounds/issue-88586-hr-self-outlives-in-trait-def.rs
index b50f56b03d9..92b7c5deb81 100644
--- a/src/test/ui/higher-rank-trait-bounds/issue-88586-hr-self-outlives-in-trait-def.rs
+++ b/src/test/ui/higher-rank-trait-bounds/issue-88586-hr-self-outlives-in-trait-def.rs
@@ -1,10 +1,12 @@
 // Regression test for #88586: a higher-ranked outlives bound on Self in a trait
 // definition caused an ICE when debug_assertions were enabled.
 //
-// FIXME: The error output in the absence of the ICE is unhelpful; this should be improved.
+// Made to pass as part of fixing #98095.
+//
+// check-pass
 
-trait A where for<'a> Self: 'a
-//~^ ERROR the parameter type `Self` may not live long enough
+trait A where
+    for<'a> Self: 'a,
 {
 }
 
diff --git a/src/test/ui/higher-rank-trait-bounds/issue-88586-hr-self-outlives-in-trait-def.stderr b/src/test/ui/higher-rank-trait-bounds/issue-88586-hr-self-outlives-in-trait-def.stderr
deleted file mode 100644
index 18618ffcc86..00000000000
--- a/src/test/ui/higher-rank-trait-bounds/issue-88586-hr-self-outlives-in-trait-def.stderr
+++ /dev/null
@@ -1,19 +0,0 @@
-error[E0311]: the parameter type `Self` may not live long enough
-  --> $DIR/issue-88586-hr-self-outlives-in-trait-def.rs:6:1
-   |
-LL | / trait A where for<'a> Self: 'a
-LL | |
-LL | | {
-LL | | }
-   | |_^
-   |
-   = help: consider adding an explicit lifetime bound `Self: 'a`...
-   = note: ...so that the type `Self` will meet its required lifetime bounds...
-note: ...that is required by this bound
-  --> $DIR/issue-88586-hr-self-outlives-in-trait-def.rs:6:29
-   |
-LL | trait A where for<'a> Self: 'a
-   |                             ^^
-
-error: aborting due to previous error
-
diff --git a/src/test/ui/nll/snocat-regression.rs b/src/test/ui/nll/snocat-regression.rs
new file mode 100644
index 00000000000..b2e5995aa5b
--- /dev/null
+++ b/src/test/ui/nll/snocat-regression.rs
@@ -0,0 +1,16 @@
+// Regression test from https://github.com/rust-lang/rust/pull/98109
+
+pub fn negotiate<S>(link: S)
+where
+    for<'a> &'a S: 'a,
+{
+    || {
+        //~^ ERROR `S` does not live long enough
+        //
+        // FIXME(#98437). This regressed at some point and
+        // probably should work.
+        let _x = link;
+    };
+}
+
+fn main() {}
diff --git a/src/test/ui/nll/snocat-regression.stderr b/src/test/ui/nll/snocat-regression.stderr
new file mode 100644
index 00000000000..0868984734d
--- /dev/null
+++ b/src/test/ui/nll/snocat-regression.stderr
@@ -0,0 +1,14 @@
+error: `S` does not live long enough
+  --> $DIR/snocat-regression.rs:7:5
+   |
+LL | /     || {
+LL | |
+LL | |         //
+LL | |         // FIXME(#98437). This regressed at some point and
+LL | |         // probably should work.
+LL | |         let _x = link;
+LL | |     };
+   | |_____^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/nll/type-test-universe.rs b/src/test/ui/nll/type-test-universe.rs
new file mode 100644
index 00000000000..f9801c07d7b
--- /dev/null
+++ b/src/test/ui/nll/type-test-universe.rs
@@ -0,0 +1,21 @@
+// Regression test for #98095: make sure that
+// we detect that S needs to outlive 'static.
+
+fn outlives_forall<T>()
+where
+    for<'u> T: 'u,
+{
+}
+
+fn test1<S>() {
+    outlives_forall::<S>();
+    //~^ ERROR `S` does not live long enough
+}
+
+struct Value<'a>(&'a ());
+fn test2<'a>() {
+    outlives_forall::<Value<'a>>();
+    //~^ ERROR lifetime may not live long enough
+}
+
+fn main() {}
diff --git a/src/test/ui/nll/type-test-universe.stderr b/src/test/ui/nll/type-test-universe.stderr
new file mode 100644
index 00000000000..242486c360a
--- /dev/null
+++ b/src/test/ui/nll/type-test-universe.stderr
@@ -0,0 +1,16 @@
+error: `S` does not live long enough
+  --> $DIR/type-test-universe.rs:11:5
+   |
+LL |     outlives_forall::<S>();
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+
+error: lifetime may not live long enough
+  --> $DIR/type-test-universe.rs:17:5
+   |
+LL | fn test2<'a>() {
+   |          -- lifetime `'a` defined here
+LL |     outlives_forall::<Value<'a>>();
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ requires that `'a` must outlive `'static`
+
+error: aborting due to 2 previous errors
+
diff --git a/src/test/ui/nll/vimwiki-core-regression.rs b/src/test/ui/nll/vimwiki-core-regression.rs
new file mode 100644
index 00000000000..0a4ed7e0a40
--- /dev/null
+++ b/src/test/ui/nll/vimwiki-core-regression.rs
@@ -0,0 +1,37 @@
+// check-pass
+//
+// Regression test from crater run for
+// <https://github.com/rust-lang/rust/pull/98109>.
+
+
+pub trait ElementLike {}
+
+pub struct Located<T> where T: ElementLike {
+    inner: T,
+}
+
+pub struct BlockElement<'a>(&'a str);
+
+impl ElementLike for BlockElement<'_> {}
+
+
+pub struct Page<'a> {
+    /// Comprised of the elements within a page
+    pub elements: Vec<Located<BlockElement<'a>>>,
+}
+
+impl<'a, __IdxT> std::ops::Index<__IdxT> for Page<'a> where
+    Vec<Located<BlockElement<'a>>>: std::ops::Index<__IdxT>
+{
+    type Output =
+        <Vec<Located<BlockElement<'a>>> as
+        std::ops::Index<__IdxT>>::Output;
+
+    #[inline]
+    fn index(&self, idx: __IdxT) -> &Self::Output {
+        <Vec<Located<BlockElement<'a>>> as
+                std::ops::Index<__IdxT>>::index(&self.elements, idx)
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/regions/forall-wf-ref-reflexive.rs b/src/test/ui/regions/forall-wf-ref-reflexive.rs
new file mode 100644
index 00000000000..9c37d72d56b
--- /dev/null
+++ b/src/test/ui/regions/forall-wf-ref-reflexive.rs
@@ -0,0 +1,18 @@
+// Test that we consider `for<'a> &'a T: 'a` to be sufficient to prove
+// that `for<'a> &'a T: 'a`.
+//
+// FIXME. Except we don't!
+
+#![allow(warnings)]
+
+fn self_wf2<T>()
+where
+    for<'a> &'a T: 'a,
+{
+    self_wf2::<T>();
+    //~^ ERROR `T` does not live long enough
+    //
+    // FIXME. This ought to be accepted, presumably.
+}
+
+fn main() {}
diff --git a/src/test/ui/regions/forall-wf-ref-reflexive.stderr b/src/test/ui/regions/forall-wf-ref-reflexive.stderr
new file mode 100644
index 00000000000..3d059ccec72
--- /dev/null
+++ b/src/test/ui/regions/forall-wf-ref-reflexive.stderr
@@ -0,0 +1,8 @@
+error: `T` does not live long enough
+  --> $DIR/forall-wf-ref-reflexive.rs:12:5
+   |
+LL |     self_wf2::<T>();
+   |     ^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
diff --git a/src/test/ui/regions/forall-wf-reflexive.rs b/src/test/ui/regions/forall-wf-reflexive.rs
new file mode 100644
index 00000000000..8e6b8224b31
--- /dev/null
+++ b/src/test/ui/regions/forall-wf-reflexive.rs
@@ -0,0 +1,15 @@
+// Test that we consider `for<'a> T: 'a` to be sufficient to prove
+// that `for<'a> T: 'a`.
+//
+// check-pass
+
+#![allow(warnings)]
+
+fn self_wf1<T>()
+where
+    for<'a> T: 'a,
+{
+    self_wf1::<T>();
+}
+
+fn main() {}