Erase regions from CallArgument, add test + bless

Author: compiler-errors

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -1630,7 +1630,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
 
             let op_arg_ty = self.normalize(op_arg_ty, term_location);
             let category = if from_hir_call {
-                ConstraintCategory::CallArgument(func_ty)
+                ConstraintCategory::CallArgument(self.infcx.tcx.erase_regions(func_ty))
             } else {
                 ConstraintCategory::Boring
             };

src/test/ui/associated-types/cache/project-fn-ret-invariant.oneuse.stderr

@@ -15,19 +15,19 @@ LL |     let a = bar(f, x);
    = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance
 
 error: lifetime may not live long enough
-  --> $DIR/project-fn-ret-invariant.rs:40:13
+  --> $DIR/project-fn-ret-invariant.rs:42:13
    |
 LL | fn baz<'a, 'b>(x: Type<'a>, y: Type<'b>) -> (Type<'a>, Type<'b>) {
    |        --  -- lifetime `'b` defined here
    |        |
    |        lifetime `'a` defined here
-LL |     let f = foo; // <-- No consistent type can be inferred for `f` here.
-LL |     let a = bar(f, x);
+...
+LL |     let b = bar(f, y);
    |             ^^^^^^^^^ argument requires that `'b` must outlive `'a`
    |
    = help: consider adding the following bound: `'b: 'a`
-   = note: requirement occurs because of a function pointer to `foo`
-   = note: the function `foo` is invariant over the parameter `'a`
+   = note: requirement occurs because of the type `Type<'_>`, which makes the generic argument `'_` invariant
+   = note: the struct `Type<'a>` is invariant over the parameter `'a`
    = help: see <https://doc.rust-lang.org/nomicon/subtyping.html> for more information about variance
 
 help: `'a` and `'b` must be the same: replace one with the other

src/test/ui/associated-types/cache/project-fn-ret-invariant.rs

@@ -39,8 +39,8 @@ fn baz<'a, 'b>(x: Type<'a>, y: Type<'b>) -> (Type<'a>, Type<'b>) {
     let f = foo; // <-- No consistent type can be inferred for `f` here.
     let a = bar(f, x);
     //[oneuse]~^ ERROR lifetime may not live long enough
-    //[oneuse]~| ERROR lifetime may not live long enough
     let b = bar(f, y);
+    //[oneuse]~^ ERROR lifetime may not live long enough
     (a, b)
 }
 

src/test/ui/borrowck/issue-103624.rs

@@ -0,0 +1,31 @@
+// edition:2021
+
+struct StructA {
+    b: StructB,
+}
+
+async fn spawn_blocking<T>(f: impl (Fn() -> T) + Send + Sync + 'static) -> T {
+    todo!()
+}
+
+impl StructA {
+    async fn foo(&self) {
+        let bar = self.b.bar().await;
+        spawn_blocking(move || {
+            //~^ ERROR borrowed data escapes outside of associated function
+            self.b;
+            //~^ ERROR cannot move out of `self.b`, as `self` is a captured variable in an `Fn` closure
+        })
+        .await;
+    }
+}
+
+struct StructB {}
+
+impl StructB {
+    async fn bar(&self) -> Option<u8> {
+        None
+    }
+}
+
+fn main() {}

src/test/ui/borrowck/issue-103624.stderr

@@ -0,0 +1,35 @@
+error[E0507]: cannot move out of `self.b`, as `self` is a captured variable in an `Fn` closure
+  --> $DIR/issue-103624.rs:16:13
+   |
+LL |     async fn foo(&self) {
+   |                  ----- captured outer variable
+LL |         let bar = self.b.bar().await;
+LL |         spawn_blocking(move || {
+   |                        ------- captured by this `Fn` closure
+LL |
+LL |             self.b;
+   |             ^^^^^^ move occurs because `self.b` has type `StructB`, which does not implement the `Copy` trait
+
+error[E0521]: borrowed data escapes outside of associated function
+  --> $DIR/issue-103624.rs:14:9
+   |
+LL |       async fn foo(&self) {
+   |                    -----
+   |                    |
+   |                    `self` is a reference that is only valid in the associated function body
+   |                    let's call the lifetime of this reference `'1`
+LL |           let bar = self.b.bar().await;
+LL | /         spawn_blocking(move || {
+LL | |
+LL | |             self.b;
+LL | |
+LL | |         })
+   | |          ^
+   | |          |
+   | |__________`self` escapes the associated function body here
+   |            argument requires that `'1` must outlive `'static`
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0507, E0521.
+For more information about an error, try `rustc --explain E0507`.