Rollup merge of #121620 - nnethercote:fix-even-more-121208-fallout, r=lcnr

Fix more #121208 fallout (round 3)

#121208 converted lots of delayed bugs to bugs. Unsurprisingly, there were a few invalid conversion found via fuzzing.

r? `@lcnr`

Author: GuillaumeGomez

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -1331,7 +1331,7 @@ impl<'a, 'tcx> BoundVarContext<'a, 'tcx> {
             }
         }
 
-        self.tcx.dcx().span_bug(
+        self.tcx.dcx().span_delayed_bug(
             lifetime_ref.ident.span,
             format!("Could not resolve {:?} in scope {:#?}", lifetime_ref, self.scope,),
         );

compiler/rustc_hir_typeck/src/method/probe.rs

@@ -804,10 +804,11 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
         let trait_ref = principal.with_self_ty(self.tcx, self_ty);
         self.elaborate_bounds(iter::once(trait_ref), |this, new_trait_ref, item| {
             if new_trait_ref.has_non_region_bound_vars() {
-                this.dcx().span_bug(
+                this.dcx().span_delayed_bug(
                     this.span,
                     "tried to select method from HRTB with non-lifetime bound vars",
                 );
+                return;
             }
 
             let new_trait_ref = this.instantiate_bound_regions_with_erased(new_trait_ref);

tests/ui/higher-ranked/trait-bounds/span-bug-issue-121597.rs

@@ -0,0 +1,20 @@
+#![allow(incomplete_features)]
+#![feature(non_lifetime_binders)]
+
+trait Foo: for<T> Bar<T> {}
+
+trait Bar<T: ?Sized> {
+    fn method(&self) {}
+}
+
+struct Type2;
+fn needs_bar(_: *mut Type2) {}
+
+fn main() {
+    let x: &dyn Foo = &();
+    //~^ ERROR the trait `Foo` cannot be made into an object
+    //~| ERROR the trait `Foo` cannot be made into an object
+
+    needs_bar(x);
+    //~^ ERROR mismatched types
+}

tests/ui/higher-ranked/trait-bounds/span-bug-issue-121597.stderr

@@ -0,0 +1,49 @@
+error[E0038]: the trait `Foo` cannot be made into an object
+  --> $DIR/span-bug-issue-121597.rs:14:23
+   |
+LL |     let x: &dyn Foo = &();
+   |                       ^^^ `Foo` cannot be made into an object
+   |
+note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
+  --> $DIR/span-bug-issue-121597.rs:4:12
+   |
+LL | trait Foo: for<T> Bar<T> {}
+   |       ---  ^^^^^^^^^^^^^ ...because where clause cannot reference non-lifetime `for<...>` variables
+   |       |
+   |       this trait cannot be made into an object...
+   = note: required for the cast from `&()` to `&dyn Foo`
+
+error[E0038]: the trait `Foo` cannot be made into an object
+  --> $DIR/span-bug-issue-121597.rs:14:12
+   |
+LL |     let x: &dyn Foo = &();
+   |            ^^^^^^^^ `Foo` cannot be made into an object
+   |
+note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
+  --> $DIR/span-bug-issue-121597.rs:4:12
+   |
+LL | trait Foo: for<T> Bar<T> {}
+   |       ---  ^^^^^^^^^^^^^ ...because where clause cannot reference non-lifetime `for<...>` variables
+   |       |
+   |       this trait cannot be made into an object...
+
+error[E0308]: mismatched types
+  --> $DIR/span-bug-issue-121597.rs:18:15
+   |
+LL |     needs_bar(x);
+   |     --------- ^ types differ in mutability
+   |     |
+   |     arguments to this function are incorrect
+   |
+   = note: expected raw pointer `*mut Type2`
+                found reference `&dyn Foo`
+note: function defined here
+  --> $DIR/span-bug-issue-121597.rs:11:4
+   |
+LL | fn needs_bar(_: *mut Type2) {}
+   |    ^^^^^^^^^ -------------
+
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0038, E0308.
+For more information about an error, try `rustc --explain E0038`.

tests/ui/lifetimes/could-not-resolve-issue-121503.rs

@@ -0,0 +1,13 @@
+//@ edition:2018
+
+#![feature(allocator_api)]
+struct Struct;
+impl Struct {
+    async fn box_ref_Struct(self: Box<Self, impl FnMut(&mut Self)>) -> &u32 {
+    //~^ ERROR the trait bound `impl FnMut(&mut Self): Allocator` is not satisfied
+    //~| ERROR Box<Struct, impl FnMut(&mut Self)>` cannot be used as the type of `self` without
+        &1
+    }
+}
+
+fn main() {}

tests/ui/lifetimes/could-not-resolve-issue-121503.stderr

@@ -0,0 +1,28 @@
+error[E0277]: the trait bound `impl FnMut(&mut Self): Allocator` is not satisfied
+  --> $DIR/could-not-resolve-issue-121503.rs:6:5
+   |
+LL |     async fn box_ref_Struct(self: Box<Self, impl FnMut(&mut Self)>) -> &u32 {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Allocator` is not implemented for `impl FnMut(&mut Self)`
+   |
+note: required by a bound in `Box`
+  --> $SRC_DIR/alloc/src/boxed.rs:LL:COL
+help: consider further restricting this bound
+   |
+LL |     async fn box_ref_Struct(self: Box<Self, impl FnMut(&mut Self) + std::alloc::Allocator>) -> &u32 {
+   |                                                                   +++++++++++++++++++++++
+
+error[E0658]: `Box<Struct, impl FnMut(&mut Self)>` cannot be used as the type of `self` without the `arbitrary_self_types` feature
+  --> $DIR/could-not-resolve-issue-121503.rs:6:35
+   |
+LL |     async fn box_ref_Struct(self: Box<Self, impl FnMut(&mut Self)>) -> &u32 {
+   |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: see issue #44874 <https://github.com/rust-lang/rust/issues/44874> for more information
+   = help: add `#![feature(arbitrary_self_types)]` to the crate attributes to enable
+   = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
+   = help: consider changing to `self`, `&self`, `&mut self`, `self: Box<Self>`, `self: Rc<Self>`, `self: Arc<Self>`, or `self: Pin<P>` (where P is one of the previous types except `Self`)
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0277, E0658.
+For more information about an error, try `rustc --explain E0277`.