Rename feature object_safe_for_dispatch to dyn_compatible_for_dispatch

Author: fmease

compiler/rustc_feature/src/removed.rs

@@ -154,6 +154,10 @@ declare_features! (
     /// then removed. But there was no utility storing it separately, so now
     /// it's in this list.
     (removed, no_stack_check, "1.0.0", None, None),
+    /// Allows making `dyn Trait` well-formed even if `Trait` is not dyn-compatible (object safe).
+    /// Renamed to `dyn_compatible_for_dispatch`.
+    (removed, object_safe_for_dispatch, "CURRENT_RUSTC_VERSION", Some(43561),
+     Some("renamed to `dyn_compatible_for_dispatch`")),
     /// Allows using `#[on_unimplemented(..)]` on traits.
     /// (Moved to `rustc_attrs`.)
     (removed, on_unimplemented, "1.40.0", None, None),

compiler/rustc_feature/src/unstable.rs

@@ -259,6 +259,14 @@ declare_features! (
     (unstable, doc_notable_trait, "1.52.0", Some(45040)),
     /// Allows using the `may_dangle` attribute (RFC 1327).
     (unstable, dropck_eyepatch, "1.10.0", Some(34761)),
+    /// Allows making `dyn Trait` well-formed even if `Trait` is not dyn-compatible[^1].
+    /// In that case, `dyn Trait: Trait` does not hold. Moreover, coercions and
+    /// casts in safe Rust to `dyn Trait` for such a `Trait` is also forbidden.
+    ///
+    /// Renamed from `object_safe_for_dispatch`.
+    ///
+    /// [^1]: Formerly known as "object safe".
+    (unstable, dyn_compatible_for_dispatch, "CURRENT_RUSTC_VERSION", Some(43561)),
     /// Allows using the `#[fundamental]` attribute.
     (unstable, fundamental, "1.0.0", Some(29635)),
     /// Allows using `#[link_name="llvm.*"]`.
@@ -544,13 +552,6 @@ declare_features! (
     (unstable, non_exhaustive_omitted_patterns_lint, "1.57.0", Some(89554)),
     /// Allows `for<T>` binders in where-clauses
     (incomplete, non_lifetime_binders, "1.69.0", Some(108185)),
-    /// Allows making `dyn Trait` well-formed even if `Trait` is not dyn-compatible[^1].
-    /// In that case, `dyn Trait: Trait` does not hold. Moreover, coercions and
-    /// casts in safe Rust to `dyn Trait` for such a `Trait` is also forbidden.
-    ///
-    /// [^1]: Formerly known as "object safe".
-    // FIXME(dyn_compat_renaming): Rename feature.
-    (unstable, object_safe_for_dispatch, "1.40.0", Some(43561)),
     /// Allows using enums in offset_of!
     (unstable, offset_of_enum, "1.75.0", Some(120141)),
     /// Allows using fields with slice type in offset_of!

compiler/rustc_hir_analysis/src/coherence/mod.rs

@@ -199,7 +199,7 @@ fn check_object_overlap<'tcx>(
         for component_def_id in component_def_ids {
             if !tcx.is_dyn_compatible(component_def_id) {
                 // FIXME(dyn_compat_renaming): Rename test and update comment.
-                // Without the 'object_safe_for_dispatch' feature this is an error
+                // Without the 'dyn_compatible_for_dispatch' feature this is an error
                 // which will be reported by wfcheck. Ignore it here.
                 // This is tested by `coherence-impl-trait-for-trait-object-safe.rs`.
                 // With the feature enabled, the trait is not implemented automatically,

compiler/rustc_span/src/symbol.rs

@@ -776,6 +776,7 @@ symbols! {
         dropck_eyepatch,
         dropck_parametricity,
         dylib,
+        dyn_compatible_for_dispatch,
         dyn_metadata,
         dyn_star,
         dyn_trait,

compiler/rustc_trait_selection/src/traits/dyn_compatibility.rs

@@ -639,8 +639,8 @@ fn object_ty_for_trait<'tcx>(
 /// contained by the trait object, because the object that needs to be coerced is behind
 /// a pointer.
 ///
-/// In practice, we cannot use `dyn Trait` explicitly in the obligation because it would result
-/// in a new check that `Trait` is dyn-compatible, creating a cycle (until object_safe_for_dispatch
+/// In practice, we cannot use `dyn Trait` explicitly in the obligation because it would result in
+/// a new check that `Trait` is dyn-compatible, creating a cycle (until dyn_compatible_for_dispatch
 /// is stabilized, see tracking issue <https://github.com/rust-lang/rust/issues/43561>).
 /// Instead, we fudge a little by introducing a new type parameter `U` such that
 /// `Self: Unsize<U>` and `U: Trait + ?Sized`, and use `U` in place of `dyn Trait`.
@@ -674,7 +674,7 @@ fn receiver_is_dispatchable<'tcx>(
 
     // the type `U` in the query
     // use a bogus type parameter to mimic a forall(U) query using u32::MAX for now.
-    // FIXME(mikeyhew) this is a total hack. Once object_safe_for_dispatch is stabilized, we can
+    // FIXME(mikeyhew) this is a total hack. Once dyn_compatible_for_dispatch is stabilized, we can
     // replace this with `dyn Trait`
     let unsized_self_ty: Ty<'tcx> =
         Ty::new_param(tcx, u32::MAX, Symbol::intern("RustaceansAreAwesome"));

compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs

@@ -881,7 +881,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                         }
 
                         if let Some(principal) = data.principal() {
-                            if !self.infcx.tcx.features().object_safe_for_dispatch {
+                            if !self.infcx.tcx.features().dyn_compatible_for_dispatch {
                                 principal.with_self_ty(self.tcx(), self_ty)
                             } else if self.tcx().is_dyn_compatible(principal.def_id()) {
                                 principal.with_self_ty(self.tcx(), self_ty)

compiler/rustc_trait_selection/src/traits/wf.rs

@@ -829,7 +829,7 @@ impl<'a, 'tcx> TypeVisitor<TyCtxt<'tcx>> for WfPredicates<'a, 'tcx> {
                 // obligations that don't refer to Self and
                 // checking those
 
-                let defer_to_coercion = tcx.features().object_safe_for_dispatch;
+                let defer_to_coercion = tcx.features().dyn_compatible_for_dispatch;
 
                 if !defer_to_coercion {
                     if let Some(principal) = data.principal_def_id() {

tests/crashes/120241-2.rs

@@ -1,6 +1,6 @@
 //@ known-bug: #120241
 //@ edition:2021
-#![feature(object_safe_for_dispatch)]
+#![feature(dyn_compatible_for_dispatch)]
 #![feature(unsized_fn_params)]
 
 fn guard(_s: Copy) -> bool {

tests/crashes/120241.rs

@@ -1,6 +1,6 @@
 //@ known-bug: #120241
 //@ edition:2021
-#![feature(object_safe_for_dispatch)]
+#![feature(dyn_compatible_for_dispatch)]
 
 trait B {
     fn f(a: A) -> A;

tests/crashes/120482.rs

@@ -1,6 +1,6 @@
 //@ known-bug: #120482
 //@ edition:2021
-#![feature(object_safe_for_dispatch)]
+#![feature(dyn_compatible_for_dispatch)]
 
 trait B {
     fn bar(&self, x: &Self);