Test invalid define_opaques attributes

compiler/rustc_ast_lowering/src/item.rs

@@ -1683,16 +1683,20 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let Some(define_opaque) = define_opaque.as_ref() else {
             return;
         };
-        let define_opaque = define_opaque
-            .iter()
-            // TODO: error reporting for non-local items being mentioned and tests that go through these code paths
-            .map(|(id, _path)| {
-                self.resolver
-                    .get_partial_res(*id)
-                    .unwrap()
-                    .expect_full_res()
-                    .def_id()
-                    .expect_local()
+        let define_opaque = define_opaque.iter().filter_map(|(id, path)| {
+            let res = self.resolver.get_partial_res(*id).unwrap();
+            let Some(did) = res.expect_full_res().opt_def_id() else {
+                self.dcx().span_delayed_bug(path.span, "should have errored in resolve");
+                return None;
+            };
+            let Some(did) = did.as_local() else {
+                self.dcx().span_err(
+                    path.span,
+                    "only opaque types defined in the local crate can be defined",
+                );
+                return None;
+            };
+            Some(did)
         });
         let define_opaque = self.arena.alloc_from_iter(define_opaque);
         self.define_opaque = Some(define_opaque);

tests/ui/type-alias-impl-trait/define_opaques_attr/foreign_type.rs

@@ -0,0 +1,5 @@
+#![feature(type_alias_impl_trait)]
+
+#[define_opaque(String)]
+//~^ ERROR: only opaque types defined in the local crate can be defined
+fn main() {}

tests/ui/type-alias-impl-trait/define_opaques_attr/foreign_type.stderr

@@ -0,0 +1,8 @@
+error: only opaque types defined in the local crate can be defined
+  --> $DIR/foreign_type.rs:3:17
+   |
+LL | #[define_opaque(String)]
+   |                 ^^^^^^
+
+error: aborting due to 1 previous error
+

tests/ui/type-alias-impl-trait/define_opaques_attr/generics.rs

@@ -0,0 +1,13 @@
+#![feature(type_alias_impl_trait)]
+
+type Tait<T> = impl Sized;
+//~^ ERROR: unconstrained opaque type
+
+#[define_opaque(Tait::<()>)]
+//~^ ERROR: expected unsuffixed literal
+fn foo() {}
+
+#[define_opaque(Tait<()>)]
+//~^ ERROR: expected one of `(`, `,`, `::`, or `=`, found `<`
+fn main() {}
+//~^ ERROR: `main` function not found

tests/ui/type-alias-impl-trait/define_opaques_attr/generics.stderr

@@ -0,0 +1,29 @@
+error: expected unsuffixed literal, found `<`
+  --> $DIR/generics.rs:6:23
+   |
+LL | #[define_opaque(Tait::<()>)]
+   |                       ^
+
+error: expected one of `(`, `,`, `::`, or `=`, found `<`
+  --> $DIR/generics.rs:10:21
+   |
+LL | #[define_opaque(Tait<()>)]
+   |                     ^ expected one of `(`, `,`, `::`, or `=`
+
+error[E0601]: `main` function not found in crate `generics`
+  --> $DIR/generics.rs:12:13
+   |
+LL | fn main() {}
+   |             ^ consider adding a `main` function to `$DIR/generics.rs`
+
+error: unconstrained opaque type
+  --> $DIR/generics.rs:3:16
+   |
+LL | type Tait<T> = impl Sized;
+   |                ^^^^^^^^^^
+   |
+   = note: `Tait` must be used in combination with a concrete type within the same crate
+
+error: aborting due to 4 previous errors
+
+For more information about this error, try `rustc --explain E0601`.

tests/ui/type-alias-impl-trait/define_opaques_attr/invalid_path.rs

@@ -0,0 +1,5 @@
+#![feature(type_alias_impl_trait)]
+
+#[define_opaque(Boom)]
+//~^ ERROR: cannot find type alias or associated type
+fn main() {}

tests/ui/type-alias-impl-trait/define_opaques_attr/invalid_path.stderr

@@ -0,0 +1,9 @@
+error[E0412]: cannot find type alias or associated type with opaqaue types `Boom` in this scope
+  --> $DIR/invalid_path.rs:3:17
+   |
+LL | #[define_opaque(Boom)]
+   |                 ^^^^ not found in this scope
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0412`.

tests/ui/type-alias-impl-trait/define_opaques_attr/missing_parens.rs

@@ -0,0 +1,5 @@
+#![feature(type_alias_impl_trait)]
+
+#[define_opaque]
+//~^ ERROR: expected list of type aliases
+fn main() {}

tests/ui/type-alias-impl-trait/define_opaques_attr/missing_parens.stderr

@@ -0,0 +1,8 @@
+error: expected list of type aliases
+  --> $DIR/missing_parens.rs:3:1
+   |
+LL | #[define_opaque]
+   | ^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+

tests/ui/type-alias-impl-trait/define_opaques_attr/no_opaque.rs

@@ -0,0 +1,8 @@
+//@ check-pass
+
+#![feature(type_alias_impl_trait)]
+
+type Thing = ();
+
+#[define_opaque(Thing)]
+fn main() {}

tests/ui/type-alias-impl-trait/define_opaques_attr/non_type.rs

@@ -0,0 +1,7 @@
+#![feature(type_alias_impl_trait)]
+
+fn foo() {}
+
+#[define_opaque(foo)]
+//~^ ERROR: expected type alias or associated type with opaqaue types
+fn main() {}

tests/ui/type-alias-impl-trait/define_opaques_attr/non_type.stderr

@@ -0,0 +1,9 @@
+error[E0573]: expected type alias or associated type with opaqaue types, found function `foo`
+  --> $DIR/non_type.rs:5:17
+   |
+LL | #[define_opaque(foo)]
+   |                 ^^^ not a type alias or associated type with opaqaue types
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0573`.