remove `TypeError::ObjectUnsafeCoercion`

[rust.git] / compiler / rustc_hir_typeck / src / coercion.rs

diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index 43c7127b0d4c56b0e8495508eb2e9f51fa784d0d..121dd4a1be1ca8c89d52e5768ba3953883a2e777 100644 (file)
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -46,7 +46,7 @@
 use rustc_hir_analysis::astconv::AstConv;
 use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind};
 use rustc_infer::infer::{Coercion, InferOk, InferResult};
-use rustc_infer::traits::{Obligation, TraitEngine, TraitEngineExt};
+use rustc_infer::traits::Obligation;
 use rustc_middle::lint::in_external_macro;
 use rustc_middle::ty::adjustment::{
     Adjust, Adjustment, AllowTwoPhase, AutoBorrow, AutoBorrowMutability, PointerCast,
@@ -62,8 +62,7 @@
 use rustc_target::spec::abi::Abi;
 use rustc_trait_selection::infer::InferCtxtExt as _;
 use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _;
-use rustc_trait_selection::traits::TraitEngineExt as _;
-use rustc_trait_selection::traits::{self, ObligationCause, ObligationCauseCode};
+use rustc_trait_selection::traits::{self, ObligationCause, ObligationCauseCode, ObligationCtxt};
 
 use smallvec::{smallvec, SmallVec};
 use std::ops::Deref;
@@ -200,10 +199,6 @@ fn coerce(&self, a: Ty<'tcx>, b: Ty<'tcx>) -> CoerceResult<'tcx> {
                 debug!("coerce: unsize successful");
                 return unsize;
             }
-            Err(TypeError::ObjectUnsafeCoercion(did)) => {
-                debug!("coerce: unsize not object safe");
-                return Err(TypeError::ObjectUnsafeCoercion(did));
-            }
             Err(error) => {
                 debug!(?error, "coerce: unsize failed");
             }
@@ -589,7 +584,7 @@ fn coerce_unsized(&self, mut source: Ty<'tcx>, mut target: Ty<'tcx>) -> CoerceRe
             }
             _ => None,
         };
-        let coerce_source = reborrow.as_ref().map_or(source, |&(_, ref r)| r.target);
+        let coerce_source = reborrow.as_ref().map_or(source, |(_, r)| r.target);
 
         // Setup either a subtyping or a LUB relationship between
         // the `CoerceUnsized` target type and the expected type.
@@ -756,20 +751,9 @@ fn coerce_dyn_star(
 
         if let ty::Dynamic(a_data, _, _) = a.kind()
             && let ty::Dynamic(b_data, _, _) = b.kind()
+            && a_data.principal_def_id() == b_data.principal_def_id()
         {
-            if a_data.principal_def_id() == b_data.principal_def_id() {
-                return self.unify_and(a, b, |_| vec![]);
-            } else if !self.tcx().features().trait_upcasting {
-                let mut err = feature_err(
-                    &self.tcx.sess.parse_sess,
-                    sym::trait_upcasting,
-                    self.cause.span,
-                    &format!(
-                        "cannot cast `{a}` to `{b}`, trait upcasting coercion is experimental"
-                    ),
-                );
-                err.emit();
-            }
+            return self.unify_and(a, b, |_| vec![]);
         }
 
         // Check the obligations of the cast -- for example, when casting
@@ -797,19 +781,16 @@ fn coerce_dyn_star(
             ])
             .collect();
 
-        // Enforce that the type is `usize`/pointer-sized. For now, only those
-        // can be coerced to `dyn*`, except for `dyn* -> dyn*` upcasts.
-        if !a.is_dyn_star() {
-            obligations.push(Obligation::new(
-                self.tcx,
-                self.cause.clone(),
-                self.param_env,
-                ty::Binder::dummy(
-                    self.tcx.at(self.cause.span).mk_trait_ref(hir::LangItem::PointerSized, [a]),
-                )
-                .to_poly_trait_predicate(),
-            ));
-        }
+        // Enforce that the type is `usize`/pointer-sized.
+        obligations.push(Obligation::new(
+            self.tcx,
+            self.cause.clone(),
+            self.param_env,
+            ty::Binder::dummy(
+                self.tcx.at(self.cause.span).mk_trait_ref(hir::LangItem::PointerSized, [a]),
+            )
+            .to_poly_trait_predicate(),
+        ));
 
         Ok(InferOk {
             value: (vec![Adjustment { kind: Adjust::DynStar, target: b }], b),
@@ -1055,9 +1036,9 @@ pub fn can_coerce(&self, expr_ty: Ty<'tcx>, target: Ty<'tcx>) -> bool {
             let Ok(ok) = coerce.coerce(source, target) else {
                 return false;
             };
-            let mut fcx = <dyn TraitEngine<'tcx>>::new_in_snapshot(self.tcx);
-            fcx.register_predicate_obligations(self, ok.obligations);
-            fcx.select_where_possible(&self).is_empty()
+            let ocx = ObligationCtxt::new_in_snapshot(self);
+            ocx.register_obligations(ok.obligations);
+            ocx.select_where_possible().is_empty()
         })
     }
 
@@ -1127,15 +1108,14 @@ fn try_find_coercion_lub<E>(
         // Special-case that coercion alone cannot handle:
         // Function items or non-capturing closures of differing IDs or InternalSubsts.
         let (a_sig, b_sig) = {
-            #[allow(rustc::usage_of_ty_tykind)]
-            let is_capturing_closure = |ty: &ty::TyKind<'tcx>| {
-                if let &ty::Closure(closure_def_id, _substs) = ty {
+            let is_capturing_closure = |ty: Ty<'tcx>| {
+                if let &ty::Closure(closure_def_id, _substs) = ty.kind() {
                     self.tcx.upvars_mentioned(closure_def_id.expect_local()).is_some()
                 } else {
                     false
                 }
             };
-            if is_capturing_closure(prev_ty.kind()) || is_capturing_closure(new_ty.kind()) {
+            if is_capturing_closure(prev_ty) || is_capturing_closure(new_ty) {
                 (None, None)
             } else {
                 match (prev_ty.kind(), new_ty.kind()) {