Support future uses of traits with associated types in rooting analysis (#34359)

* crown: Support Rc<T::Promise> and callback objects parameterized over a trait..

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

* crown: Verify that attributes match between trait associated types and impls.

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

* crown: Check type aliases as part of associated type checks.

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

* crown: Add periods to all diagnostic messages.

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

* Tidy.

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

* Fix compile-fail test expectations.

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

---------

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

support/crown/tests/compile-fail/missing_allow_in_rc.rs

@@ -0,0 +1,30 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+//@rustc-env:RUSTC_BOOTSTRAP=1
+
+#![allow(dead_code)]
+
+use std::rc::Rc;
+
+trait TypeHolderTrait {
+    #[crown::unrooted_must_root_lint::must_root]
+    type F;
+    //~^ ERROR: Mismatched use of #[crown::unrooted_must_root_lint::allow_unrooted_interior_in_rc] between associated type declaration and impl definition. [crown::unrooted_must_root]
+}
+
+struct TypeHolder;
+impl TypeHolderTrait for TypeHolder {
+    type F = Foo;
+}
+
+#[crown::unrooted_must_root_lint::must_root]
+#[crown::unrooted_must_root_lint::allow_unrooted_in_rc]
+struct Foo;
+
+fn foo<T: TypeHolderTrait>() -> Rc<T::F> {
+    //~^ ERROR: Type must be rooted. [crown::unrooted_must_root]
+    unimplemented!()
+}
+
+fn main() {}

support/crown/tests/compile-fail/missing_unrooted_interior.rs

@@ -0,0 +1,17 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+//@rustc-env:RUSTC_BOOTSTRAP=1
+
+#![allow(dead_code)]
+
+#[crown::unrooted_must_root_lint::must_root]
+struct MustBeRooted;
+
+struct CanBeUnrooted {
+    val: MustBeRooted,
+    //~^ ERROR: Type must be rooted, use #[crown::unrooted_must_root_lint::must_root] on the struct definition to propagate. [crown::unrooted_must_root]
+}
+
+
+fn main() {}

support/crown/tests/compile-fail/missing_unrooted_interior_on_trait.rs

@@ -0,0 +1,25 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+//@rustc-env:RUSTC_BOOTSTRAP=1
+
+#![allow(dead_code)]
+
+trait TypeHolderTrait {
+    #[crown::unrooted_must_root_lint::must_root]
+    type F: Default;
+}
+
+struct TypeHolder;
+impl TypeHolderTrait for TypeHolder {
+    type F = Foo;
+}
+
+#[crown::unrooted_must_root_lint::must_root]
+#[derive(Default)]
+struct Foo;
+
+struct MustBeRooted<T: TypeHolderTrait>(T::F);
+//~^ ERROR: Type must be rooted, use #[crown::unrooted_must_root_lint::must_root] on the struct definition to propagate. [crown::unrooted_must_root]
+
+fn main() {}

support/crown/tests/compile-fail/trait_type_impl_must_root.rs

@@ -18,4 +18,4 @@ impl Trait for TypeHolder {
     type F = Foo;
 }
 
-fn main() {}
+fn main() {}

support/crown/tests/compile-fail/type_holder_user_must_root.rs

@@ -11,6 +11,7 @@ struct Bar<TH: TypeHolderTrait>(TH::F);
 trait TypeHolderTrait {
     #[crown::unrooted_must_root_lint::must_root]
     type F;
+    //~^ Mismatched use of #[crown::unrooted_must_root_lint::must_root] between associated type declaration and impl definition. [crown::unrooted_must_root]
 }
 
 struct TypeHolder;

support/crown/tests/run-pass/allow_interior_trait.rs

@@ -0,0 +1,28 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+//@rustc-env:RUSTC_BOOTSTRAP=1
+
+#![allow(dead_code)]
+
+trait TypeHolderTrait {
+    #[crown::unrooted_must_root_lint::must_root]
+    type F;
+}
+
+struct TypeHolder;
+impl TypeHolderTrait for TypeHolder {
+    type F = Foo;
+}
+
+
+#[crown::unrooted_must_root_lint::must_root]
+struct Foo;
+
+#[crown::unrooted_must_root_lint::must_root]
+struct MustBeRooted<T: TypeHolderTrait>(T::F);
+
+#[crown::unrooted_must_root_lint::allow_unrooted_interior]
+struct CanBeUnrooted<T: TypeHolderTrait>(MustBeRooted<T>);
+
+fn main() {}

support/crown/tests/run-pass/allow_trait_in_rc.rs

@@ -0,0 +1,29 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+//@rustc-env:RUSTC_BOOTSTRAP=1
+
+#![allow(dead_code)]
+
+use std::rc::Rc;
+
+trait TypeHolderTrait {
+    #[crown::unrooted_must_root_lint::must_root]
+    #[crown::unrooted_must_root_lint::allow_unrooted_in_rc]
+    type F;
+}
+
+struct TypeHolder;
+impl TypeHolderTrait for TypeHolder {
+    type F = Foo;
+}
+
+#[crown::unrooted_must_root_lint::must_root]
+#[crown::unrooted_must_root_lint::allow_unrooted_in_rc]
+struct Foo;
+
+fn foo<T: TypeHolderTrait>() -> Rc<T::F> {
+    unimplemented!()
+}
+
+fn main() {}

support/crown/tests/run-pass/allowed_interior.rs

@@ -0,0 +1,16 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+//@rustc-env:RUSTC_BOOTSTRAP=1
+
+#![allow(dead_code)]
+
+#[crown::unrooted_must_root_lint::must_root]
+struct MustBeRooted;
+
+#[crown::unrooted_must_root_lint::allow_unrooted_interior]
+struct CanBeUnrooted {
+    val: MustBeRooted,
+}
+
+fn main() {}