Auto merge of #96695 - JohnTitor:rollup-oo4fc1h, r=JohnTitor

Rollup of 6 pull requests

Successful merges:

 - #96597 (openbsd: unbreak build on native platform)
 - #96662 (Fix typo in lint levels doc)
 - #96668 (Fix flaky rustdoc-ui test because it did not replace time result)
 - #96679 (Quick fix for #96223.)
 - #96684 (Update `ProjectionElem::Downcast` documentation)
 - #96686 (Add some TAIT-related tests)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

compiler/rustc_middle/src/mir/mod.rs

@@ -2017,9 +2017,7 @@ pub enum ProjectionElem<V, T> {
         from_end: bool,
     },
 
-    /// "Downcast" to a variant of an ADT. Currently, we only introduce
-    /// this for ADTs with more than one variant. It may be better to
-    /// just introduce it always, or always for enums.
+    /// "Downcast" to a variant of an enum or a generator.
     ///
     /// The included Symbol is the name of the variant, used for printing MIR.
     Downcast(Option<Symbol>, VariantIdx),

compiler/rustc_middle/src/mir/tcx.rs

@@ -12,7 +12,7 @@ use rustc_target::abi::VariantIdx;
 #[derive(Copy, Clone, Debug, TypeFoldable)]
 pub struct PlaceTy<'tcx> {
     pub ty: Ty<'tcx>,
-    /// Downcast to a particular variant of an enum, if included.
+    /// Downcast to a particular variant of an enum or a generator, if included.
     pub variant_index: Option<VariantIdx>,
 }
 

compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs

@@ -866,7 +866,13 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
                 return false;
             }
 
-            let orig_ty = old_pred.self_ty().skip_binder();
+            // This is a quick fix to resolve an ICE (#96223).
+            // This change should probably be deeper.
+            // As suggested by @jackh726, `mk_trait_obligation_with_new_self_ty` could take a `Binder<(TraitRef, Ty)>
+            // instead of `Binder<Ty>` leading to some changes to its call places.
+            let Some(orig_ty) = old_pred.self_ty().no_bound_vars() else {
+                return false;
+            };
             let mk_result = |new_ty| {
                 let obligation =
                     self.mk_trait_obligation_with_new_self_ty(param_env, old_pred, new_ty);

src/bootstrap/builder.rs

@@ -1405,7 +1405,8 @@ impl<'a> Builder<'a> {
         // FIXME(davidtwco): #[cfg(not(bootstrap))] - #95612 needs to be in the bootstrap compiler
         // for this conditional to be removed.
         if !target.contains("windows") || compiler.stage >= 1 {
-            if target.contains("linux") || target.contains("windows") {
+            if target.contains("linux") || target.contains("windows") || target.contains("openbsd")
+            {
                 rustflags.arg("-Zunstable-options");
             }
             match self.config.rust_split_debuginfo {

src/doc/rustc/src/lints/levels.md

@@ -100,9 +100,8 @@ This lint level gives you that.
 'force-warn' does for 'warn'. It's the same as 'deny' in that a lint at this
 level will produce an error, but unlike the 'deny' level, the 'forbid' level
 can not be overridden to be anything lower than an error.  However, lint
-levels may still be capped with `--cap-lints` (see below) so `rustc --cap-
-lints warn` will make lints set to 'forbid' just
-warn.
+levels may still be capped with `--cap-lints` (see below) so `rustc --cap-lints warn`
+will make lints set to 'forbid' just warn.
 
 ## Configuring warning levels
 

src/test/rustdoc-ui/block-doc-comment.rs

@@ -1,5 +1,6 @@
 // check-pass
 // compile-flags:--test
+// normalize-stdout-test "finished in \d+\.\d+s" -> "finished in $$TIME"
 
 // This test ensures that no code block is detected in the doc comments.
 

src/test/rustdoc-ui/block-doc-comment.stdout

@@ -1,5 +1,5 @@
 
 running 0 tests
 
-test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
+test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in $TIME
 

src/test/ui/suggestions/issue-96223.rs

@@ -0,0 +1,52 @@
+// Previously ICEd because we didn't properly track binders in suggestions
+// check-fail
+
+pub trait Foo<'de>: Sized {}
+
+pub trait Bar<'a>: 'static {
+    type Inner: 'a;
+}
+
+pub trait Fubar {
+    type Bar: for<'a> Bar<'a>;
+}
+
+pub struct Baz<T>(pub T);
+
+impl<'de, T> Foo<'de> for Baz<T> where T: Foo<'de> {}
+
+struct Empty;
+
+impl<M> Dummy<M> for Empty
+where
+    M: Fubar,
+    for<'de> Baz<<M::Bar as Bar<'de>>::Inner>: Foo<'de>,
+{
+}
+
+pub trait Dummy<M>
+where
+    M: Fubar,
+{
+}
+
+pub struct EmptyBis<'a>(&'a [u8]);
+
+impl<'a> Bar<'a> for EmptyBis<'static> {
+    type Inner = EmptyBis<'a>;
+}
+
+pub struct EmptyMarker;
+
+impl Fubar for EmptyMarker {
+    type Bar = EmptyBis<'static>;
+}
+
+fn icey_bounds<D: Dummy<EmptyMarker>>(p: &D) {}
+
+fn trigger_ice() {
+    let p = Empty;
+    icey_bounds(&p); //~ERROR the trait bound
+}
+
+fn main() {}

src/test/ui/suggestions/issue-96223.stderr

@@ -0,0 +1,28 @@
+error[E0277]: the trait bound `for<'de> EmptyBis<'de>: Foo<'_>` is not satisfied
+  --> $DIR/issue-96223.rs:49:17
+   |
+LL |     icey_bounds(&p);
+   |     ----------- ^^ the trait `for<'de> Foo<'_>` is not implemented for `EmptyBis<'de>`
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = help: the trait `Foo<'de>` is implemented for `Baz<T>`
+note: required because of the requirements on the impl of `for<'de> Foo<'de>` for `Baz<EmptyBis<'de>>`
+  --> $DIR/issue-96223.rs:16:14
+   |
+LL | impl<'de, T> Foo<'de> for Baz<T> where T: Foo<'de> {}
+   |              ^^^^^^^^     ^^^^^^
+note: required because of the requirements on the impl of `Dummy<EmptyMarker>` for `Empty`
+  --> $DIR/issue-96223.rs:20:9
+   |
+LL | impl<M> Dummy<M> for Empty
+   |         ^^^^^^^^     ^^^^^
+note: required by a bound in `icey_bounds`
+  --> $DIR/issue-96223.rs:45:19
+   |
+LL | fn icey_bounds<D: Dummy<EmptyMarker>>(p: &D) {}
+   |                   ^^^^^^^^^^^^^^^^^^ required by this bound in `icey_bounds`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.

src/test/ui/type-alias-impl-trait/issue-53398-cyclic-types.rs

@@ -0,0 +1,9 @@
+#![feature(type_alias_impl_trait)]
+
+type Foo = impl Fn() -> Foo;
+
+fn foo() -> Foo {
+    foo //~ ERROR: overflow evaluating the requirement `fn() -> Foo {foo}: Sized`
+}
+
+fn main() {}