Compiler & its UI tests: Rename remaining occurrences of "object safe" to "dyn compatible"

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

@@ -1,12 +1,8 @@
-//! "Object safety" refers to the ability for a trait to be converted
-//! to an object. In general, traits may only be converted to an
-//! object if all of their methods meet certain criteria. In particular,
-//! they must:
+//! "Dyn-compatibility"[^1] refers to the ability for a trait to be converted
+//! to a trait object. In general, traits may only be converted to a trait
+//! object if certain criteria are met.
 //!
-//! - have a suitable receiver from which we can extract a vtable and coerce to a "thin" version
-//! that doesn't contain the vtable;
-//! - not reference the erased type `Self` except for in this receiver;
-//! - not have generic type parameters.
+//! [^1]: Formerly known as "object safety".
 
 use std::iter;
 use std::ops::ControlFlow;
@@ -506,8 +502,8 @@ fn virtual_call_violations_for_method<'tcx>(
 
 /// This code checks that `receiver_is_dispatchable` is correctly implemented.
 ///
-/// This check is outlined from the object safety check to avoid cycles with
-/// layout computation, which relies on knowing whether methods are object safe.
+/// This check is outlined from the dyn-compatibility check to avoid cycles with
+/// layout computation, which relies on knowing whether methods are dyn-compatible.
 fn check_receiver_correct<'tcx>(tcx: TyCtxt<'tcx>, trait_def_id: DefId, method: ty::AssocItem) {
  if !is_vtable_safe_method(tcx, trait_def_id, method) {
  return;
@@ -643,8 +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 object safe, 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`.
@@ -678,7 +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"));
@@ -865,7 +861,7 @@ impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for IllegalSelfTypeVisitor<'tcx> {
  }
 
  fn visit_const(&mut self, ct: ty::Const<'tcx>) -> Self::Result {
- // Constants can only influence object safety if they are generic and reference `Self`.
+ // Constants can only influence dyn-compatibility if they are generic and reference `Self`.
  // This is only possible for unevaluated constants, so we walk these here.
  self.tcx.expand_abstract_consts(ct).super_visit_with(self)
  }

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() {

src/tools/tidy/src/issues.txt

@@ -3173,10 +3173,6 @@ ui/nll/user-annotations/issue-55241.rs
 ui/nll/user-annotations/issue-55748-pat-types-constrain-bindings.rs
 ui/nll/user-annotations/issue-57731-ascibed-coupled-types.rs
 ui/numbers-arithmetic/issue-8460.rs
-ui/object-safety/issue-102762.rs
-ui/object-safety/issue-102933.rs
-ui/object-safety/issue-106247.rs
-ui/object-safety/issue-19538.rs
 ui/on-unimplemented/issue-104140.rs
 ui/or-patterns/issue-64879-trailing-before-guard.rs
 ui/or-patterns/issue-67514-irrefutable-param.rs

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);

tests/crashes/125512.rs

@@ -1,6 +1,6 @@
 //@ known-bug: rust-lang/rust#125512
 //@ edition:2021
-#![feature(object_safe_for_dispatch)]
+#![feature(dyn_compatible_for_dispatch)]
 trait B {
  fn f(a: A) -> A;
 }

tests/crashes/128176.rs

@@ -1,7 +1,7 @@
 //@ known-bug: rust-lang/rust#128176
 
 #![feature(generic_const_exprs)]
-#![feature(object_safe_for_dispatch)]
+#![feature(dyn_compatible_for_dispatch)]
 trait X {
  type Y<const N: i16>;
 }

tests/crashes/130521.rs

@@ -1,6 +1,6 @@
 //@ known-bug: #130521
 
-#![feature(object_safe_for_dispatch)]
+#![feature(dyn_compatible_for_dispatch)]
 struct Vtable(dyn Cap);
 
 trait Cap<'a> {}

tests/ui/allocator/dyn-compatible.rs

@@ -0,0 +1,13 @@
+//@ run-pass
+
+// Check that `Allocator` is dyn-compatible, this allows for polymorphic allocators
+
+#![feature(allocator_api)]
+
+use std::alloc::{Allocator, System};
+
+fn ensure_dyn_compatible(_: &dyn Allocator) {}
+
+fn main() {
+ ensure_dyn_compatible(&System);
+}

tests/ui/associated-type-bounds/entails-sized-object-safety.rs → tests/ui/associated-type-bounds/entails-sized-dyn-compatibility.rs

@@ -4,21 +4,21 @@ trait Tr1: Sized { type As1; }
 trait Tr2<'a>: Sized { type As2; }
 
 trait ObjTr1 { fn foo() -> Self where Self: Tr1<As1: Copy>; }
-fn _assert_obj_safe_1(_: Box<dyn ObjTr1>) {}
+fn _assert_dyn_compat_1(_: Box<dyn ObjTr1>) {}
 
 trait ObjTr2 { fn foo() -> Self where Self: Tr1<As1: 'static>; }
-fn _assert_obj_safe_2(_: Box<dyn ObjTr2>) {}
+fn _assert_dyn_compat_2(_: Box<dyn ObjTr2>) {}
 
 trait ObjTr3 { fn foo() -> Self where Self: Tr1<As1: Into<u8> + 'static + Copy>; }
-fn _assert_obj_safe_3(_: Box<dyn ObjTr3>) {}
+fn _assert_dyn_compat_3(_: Box<dyn ObjTr3>) {}
 
 trait ObjTr4 { fn foo() -> Self where Self: Tr1<As1: for<'a> Tr2<'a>>; }
-fn _assert_obj_safe_4(_: Box<dyn ObjTr4>) {}
+fn _assert_dyn_compat_4(_: Box<dyn ObjTr4>) {}
 
 trait ObjTr5 { fn foo() -> Self where for<'a> Self: Tr1<As1: Tr2<'a>>; }
-fn _assert_obj_safe_5(_: Box<dyn ObjTr5>) {}
+fn _assert_dyn_compat_5(_: Box<dyn ObjTr5>) {}
 
 trait ObjTr6 { fn foo() -> Self where Self: for<'a> Tr1<As1: Tr2<'a, As2: for<'b> Tr2<'b>>>; }
-fn _assert_obj_safe_6(_: Box<dyn ObjTr6>) {}
+fn _assert_dyn_compat_6(_: Box<dyn ObjTr6>) {}
 
 fn main() {}

tests/ui/async-await/in-trait/object-safety.stderr → tests/ui/async-await/in-trait/dyn-compatibility.stderr

@@ -1,11 +1,11 @@
 error[E0038]: the trait `Foo` cannot be made into an object
- --> $DIR/object-safety.rs:9:12
+ --> $DIR/dyn-compatibility.rs:9:12
  |
 LL | let x: &dyn Foo = todo!();
  | ^^^^^^^^ `Foo` cannot be made into an object
  |
 note: for a trait to be "dyn-compatible" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
- --> $DIR/object-safety.rs:5:14
+ --> $DIR/dyn-compatibility.rs:5:14
  |
 LL | trait Foo {
  | --- this trait cannot be made into an object...

tests/ui/coherence/coherence-impl-trait-for-trait-object-safe.rs → tests/ui/coherence/coherence-impl-trait-for-trait-dyn-compatible.rs

@@ -1,10 +1,10 @@
 // Test that we give suitable error messages when the user attempts to
 // impl a trait `Trait` for its own object type.
 
-// If the trait is not object-safe, we give a more tailored message
+// If the trait is dyn-incompatible, we give a more tailored message
 // because we're such schnuckels:
-trait NotObjectSafe { fn eq(&self, other: Self); }
-impl NotObjectSafe for dyn NotObjectSafe { }
+trait DynIncompatible { fn eq(&self, other: Self); }
+impl DynIncompatible for dyn DynIncompatible { }
 //~^ ERROR E0038
 //~| ERROR E0046
 

tests/ui/coherence/coherence-impl-trait-for-trait-dyn-compatible.stderr

@@ -0,0 +1,27 @@
+error[E0038]: the trait `DynIncompatible` cannot be made into an object
+ --> $DIR/coherence-impl-trait-for-trait-dyn-compatible.rs:7:26
+ |
+LL | impl DynIncompatible for dyn DynIncompatible { }
+ | ^^^^^^^^^^^^^^^^^^^ `DynIncompatible` cannot be made into an object
+ |
+note: for a trait to be "dyn-compatible" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
+ --> $DIR/coherence-impl-trait-for-trait-dyn-compatible.rs:6:45
+ |
+LL | trait DynIncompatible { fn eq(&self, other: Self); }
+ | --------------- ^^^^ ...because method `eq` references the `Self` type in this parameter
+ | |
+ | this trait cannot be made into an object...
+ = help: consider moving `eq` to another trait
+
+error[E0046]: not all trait items implemented, missing: `eq`
+ --> $DIR/coherence-impl-trait-for-trait-dyn-compatible.rs:7:1
+ |
+LL | trait DynIncompatible { fn eq(&self, other: Self); }
+ | -------------------------- `eq` from trait
+LL | impl DynIncompatible for dyn DynIncompatible { }
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `eq` in implementation
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0038, E0046.
+For more information about an error, try `rustc --explain E0038`.

tests/ui/coherence/coherence-unsafe-trait-object-impl.rs

@@ -1,7 +1,7 @@
 // Check that unsafe trait object do not implement themselves
 // automatically
 
-#![feature(object_safe_for_dispatch)]
+#![feature(dyn_compatible_for_dispatch)]
 
 trait Trait: Sized {
  fn call(&self);

tests/ui/const-generics/adt_const_params/const_param_ty_object_safety.stderr → tests/ui/const-generics/adt_const_params/const_param_ty_dyn_compatibility.stderr

@@ -1,5 +1,5 @@
 error[E0038]: the trait `ConstParamTy_` cannot be made into an object
- --> $DIR/const_param_ty_object_safety.rs:6:12
+ --> $DIR/const_param_ty_dyn_compatibility.rs:6:12
  |
 LL | fn foo(a: &dyn ConstParamTy_) {}
  | ^^^^^^^^^^^^^^^^^ `ConstParamTy_` cannot be made into an object
@@ -14,7 +14,7 @@ LL | fn foo(a: &impl ConstParamTy_) {}
  | ~~~~
 
 error[E0038]: the trait `UnsizedConstParamTy` cannot be made into an object
- --> $DIR/const_param_ty_object_safety.rs:9:12
+ --> $DIR/const_param_ty_dyn_compatibility.rs:9:12
  |
 LL | fn bar(a: &dyn UnsizedConstParamTy) {}
  | ^^^^^^^^^^^^^^^^^^^^^^^ `UnsizedConstParamTy` cannot be made into an object

tests/ui/const-generics/generic_const_exprs/object-safety-err-ret.stderr → tests/ui/const-generics/generic_const_exprs/dyn-compatibility-err-ret.stderr

@@ -1,11 +1,11 @@
 error[E0038]: the trait `Foo` cannot be made into an object
- --> $DIR/object-safety-err-ret.rs:17:16
+ --> $DIR/dyn-compatibility-err-ret.rs:17:16
  |
 LL | fn use_dyn(v: &dyn Foo) {
  | ^^^^^^^ `Foo` cannot be made into an object
  |
 note: for a trait to be "dyn-compatible" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
- --> $DIR/object-safety-err-ret.rs:8:8
+ --> $DIR/dyn-compatibility-err-ret.rs:8:8
  |
 LL | trait Foo {
  | --- this trait cannot be made into an object...
@@ -17,13 +17,13 @@ LL | fn test(&self) -> [u8; bar::<Self>()];
  = help: only type `()` implements the trait, consider using it directly instead
 
 error[E0038]: the trait `Foo` cannot be made into an object
- --> $DIR/object-safety-err-ret.rs:18:5
+ --> $DIR/dyn-compatibility-err-ret.rs:18:5
  |
 LL | v.test();
  | ^^^^^^^^ `Foo` cannot be made into an object
  |
 note: for a trait to be "dyn-compatible" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety>
- --> $DIR/object-safety-err-ret.rs:8:8
+ --> $DIR/dyn-compatibility-err-ret.rs:8:8
  |
 LL | trait Foo {
  | --- this trait cannot be made into an object...