Rollup merge of #105983 - compiler-errors:issue-105981, r=tmiasko

Add a missing early return in drop tracking `handle_uninhabited_return`

This return is needed so we don't call `Ty::is_inhabited_from` from a type with ty/ct vars in it.

Fixes #105981

compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs

@@ -233,6 +233,7 @@ impl<'a, 'tcx> DropRangeVisitor<'a, 'tcx> {
             self.tcx()
                 .sess
                 .delay_span_bug(expr.span, format!("could not resolve infer vars in `{ty}`"));
+            return;
         }
         let ty = self.tcx().erase_regions(ty);
         let m = self.tcx().parent_module(expr.hir_id).to_def_id();

src/test/ui/generator/unresolved-ct-var-drop-tracking.rs

@@ -0,0 +1,15 @@
+// incremental
+// edition:2021
+// compile-flags: -Zdrop-tracking
+
+fn main() {
+    let _ = async {
+        let s = std::array::from_fn(|_| ()).await;
+        //~^ ERROR `[(); _]` is not a future
+        //~| ERROR type inside `async` block must be known in this context
+        //~| ERROR type inside `async` block must be known in this context
+        //~| ERROR type inside `async` block must be known in this context
+        //~| ERROR type inside `async` block must be known in this context
+        //~| ERROR type inside `async` block must be known in this context
+    };
+}

src/test/ui/generator/unresolved-ct-var-drop-tracking.stderr

@@ -0,0 +1,78 @@
+error[E0277]: `[(); _]` is not a future
+  --> $DIR/unresolved-ct-var-drop-tracking.rs:7:44
+   |
+LL |         let s = std::array::from_fn(|_| ()).await;
+   |                 ---------------------------^^^^^^
+   |                 |                          |
+   |                 |                          `[(); _]` is not a future
+   |                 |                          help: remove the `.await`
+   |                 this call returns `[(); _]`
+   |
+   = help: the trait `Future` is not implemented for `[(); _]`
+   = note: [(); _] must be a future or must implement `IntoFuture` to be awaited
+   = note: required for `[(); _]` to implement `IntoFuture`
+
+error[E0698]: type inside `async` block must be known in this context
+  --> $DIR/unresolved-ct-var-drop-tracking.rs:7:17
+   |
+LL |         let s = std::array::from_fn(|_| ()).await;
+   |                 ^^^^^^^^^^^^^^^^^^^ cannot infer the value of const parameter `N` declared on the function `from_fn`
+   |
+note: the type is part of the `async` block because of this `await`
+  --> $DIR/unresolved-ct-var-drop-tracking.rs:7:44
+   |
+LL |         let s = std::array::from_fn(|_| ()).await;
+   |                                            ^^^^^^
+
+error[E0698]: type inside `async` block must be known in this context
+  --> $DIR/unresolved-ct-var-drop-tracking.rs:7:17
+   |
+LL |         let s = std::array::from_fn(|_| ()).await;
+   |                 ^^^^^^^^^^^^^^^^^^^ cannot infer the value of const parameter `N` declared on the function `from_fn`
+   |
+note: the type is part of the `async` block because of this `await`
+  --> $DIR/unresolved-ct-var-drop-tracking.rs:7:44
+   |
+LL |         let s = std::array::from_fn(|_| ()).await;
+   |                                            ^^^^^^
+
+error[E0698]: type inside `async` block must be known in this context
+  --> $DIR/unresolved-ct-var-drop-tracking.rs:7:17
+   |
+LL |         let s = std::array::from_fn(|_| ()).await;
+   |                 ^^^^^^^^^^^^^^^^^^^ cannot infer the value of const parameter `N` declared on the function `from_fn`
+   |
+note: the type is part of the `async` block because of this `await`
+  --> $DIR/unresolved-ct-var-drop-tracking.rs:7:44
+   |
+LL |         let s = std::array::from_fn(|_| ()).await;
+   |                                            ^^^^^^
+
+error[E0698]: type inside `async` block must be known in this context
+  --> $DIR/unresolved-ct-var-drop-tracking.rs:7:17
+   |
+LL |         let s = std::array::from_fn(|_| ()).await;
+   |                 ^^^^^^^^^^^^^^^^^^^ cannot infer the value of const parameter `N` declared on the function `from_fn`
+   |
+note: the type is part of the `async` block because of this `await`
+  --> $DIR/unresolved-ct-var-drop-tracking.rs:7:44
+   |
+LL |         let s = std::array::from_fn(|_| ()).await;
+   |                                            ^^^^^^
+
+error[E0698]: type inside `async` block must be known in this context
+  --> $DIR/unresolved-ct-var-drop-tracking.rs:7:17
+   |
+LL |         let s = std::array::from_fn(|_| ()).await;
+   |                 ^^^^^^^^^^^^^^^^^^^ cannot infer the value of const parameter `N` declared on the function `from_fn`
+   |
+note: the type is part of the `async` block because of this `await`
+  --> $DIR/unresolved-ct-var-drop-tracking.rs:7:44
+   |
+LL |         let s = std::array::from_fn(|_| ()).await;
+   |                                            ^^^^^^
+
+error: aborting due to 6 previous errors
+
+Some errors have detailed explanations: E0277, E0698.
+For more information about an error, try `rustc --explain E0277`.