diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/librustc_infer/infer/region_constraints/mod.rs | 4 | ||||
| -rw-r--r-- | src/librustc_trait_selection/traits/select/mod.rs | 31 | ||||
| -rw-r--r-- | src/librustc_trait_selection/traits/specialize/mod.rs | 2 | ||||
| -rw-r--r-- | src/librustc_typeck/check/compare_method.rs | 32 |
4 files changed, 34 insertions, 35 deletions
diff --git a/src/librustc_infer/infer/region_constraints/mod.rs b/src/librustc_infer/infer/region_constraints/mod.rs index 90d61a78f9b..42a6a6ff40a 100644 --- a/src/librustc_infer/infer/region_constraints/mod.rs +++ b/src/librustc_infer/infer/region_constraints/mod.rs @@ -290,7 +290,7 @@ pub(crate) enum UndoLog<'tcx> { /// We added a GLB/LUB "combination variable". AddCombination(CombineMapType, TwoRegions<'tcx>), - /// During skolemization, we sometimes purge entries from the undo + /// During freshening, we sometimes purge entries from the undo /// log in a kind of minisnapshot (unlike other snapshots, this /// purging actually takes place *on success*). In that case, we /// replace the corresponding entry with `Noop` so as to avoid the @@ -489,7 +489,7 @@ impl<'tcx> RegionConstraintCollector<'_, 'tcx> { } /// Removes all the edges to/from the placeholder regions that are - /// in `skols`. This is used after a higher-ranked operation + /// in `placeholders`. This is used after a higher-ranked operation /// completes to remove all trace of the placeholder regions /// created in that time. pub fn pop_placeholders(&mut self, placeholders: &FxHashSet<ty::Region<'tcx>>) { diff --git a/src/librustc_trait_selection/traits/select/mod.rs b/src/librustc_trait_selection/traits/select/mod.rs index 3fd566eab43..c3b1079fb12 100644 --- a/src/librustc_trait_selection/traits/select/mod.rs +++ b/src/librustc_trait_selection/traits/select/mod.rs @@ -1754,27 +1754,26 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { ) -> Vec<PredicateObligation<'tcx>> { // Because the types were potentially derived from // higher-ranked obligations they may reference late-bound - // regions. For example, `for<'a> Foo<&'a int> : Copy` would - // yield a type like `for<'a> &'a int`. In general, we + // regions. For example, `for<'a> Foo<&'a i32> : Copy` would + // yield a type like `for<'a> &'a i32`. In general, we // maintain the invariant that we never manipulate bound // regions, so we have to process these bound regions somehow. // // The strategy is to: // // 1. Instantiate those regions to placeholder regions (e.g., - // `for<'a> &'a int` becomes `&0 int`. - // 2. Produce something like `&'0 int : Copy` - // 3. Re-bind the regions back to `for<'a> &'a int : Copy` + // `for<'a> &'a int` becomes `&0 i32`. + // 2. Produce something like `&'0 i32 : Copy` + // 3. Re-bind the regions back to `for<'a> &'a i32 : Copy` types - .skip_binder() + .skip_binder() // binder moved -\ .iter() .flat_map(|ty| { - // binder moved -\ let ty: ty::Binder<Ty<'tcx>> = ty::Binder::bind(ty); // <----/ self.infcx.commit_unconditionally(|_| { - let (skol_ty, _) = self.infcx.replace_bound_vars_with_placeholders(&ty); + let (placeholder_ty, _) = self.infcx.replace_bound_vars_with_placeholders(&ty); let Normalized { value: normalized_ty, mut obligations } = ensure_sufficient_stack(|| { project::normalize_with_depth( @@ -1782,10 +1781,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { param_env, cause.clone(), recursion_depth, - &skol_ty, + &placeholder_ty, ) }); - let skol_obligation = predicate_for_trait_def( + let placeholder_obligation = predicate_for_trait_def( self.tcx(), param_env, cause.clone(), @@ -1794,7 +1793,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { normalized_ty, &[], ); - obligations.push(skol_obligation); + obligations.push(placeholder_obligation); obligations }) }) @@ -1844,9 +1843,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { return Err(()); } - let (skol_obligation, placeholder_map) = + let (placeholder_obligation, placeholder_map) = self.infcx().replace_bound_vars_with_placeholders(&obligation.predicate); - let skol_obligation_trait_ref = skol_obligation.trait_ref; + let placeholder_obligation_trait_ref = placeholder_obligation.trait_ref; let impl_substs = self.infcx.fresh_substs_for_item(obligation.cause.span, impl_def_id); @@ -1865,14 +1864,14 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { debug!( "match_impl(impl_def_id={:?}, obligation={:?}, \ - impl_trait_ref={:?}, skol_obligation_trait_ref={:?})", - impl_def_id, obligation, impl_trait_ref, skol_obligation_trait_ref + impl_trait_ref={:?}, placeholder_obligation_trait_ref={:?})", + impl_def_id, obligation, impl_trait_ref, placeholder_obligation_trait_ref ); let InferOk { obligations, .. } = self .infcx .at(&obligation.cause, obligation.param_env) - .eq(skol_obligation_trait_ref, impl_trait_ref) + .eq(placeholder_obligation_trait_ref, impl_trait_ref) .map_err(|e| debug!("match_impl: failed eq_trait_refs due to `{}`", e))?; nested_obligations.extend(obligations); diff --git a/src/librustc_trait_selection/traits/specialize/mod.rs b/src/librustc_trait_selection/traits/specialize/mod.rs index 2b596be9542..42901102c10 100644 --- a/src/librustc_trait_selection/traits/specialize/mod.rs +++ b/src/librustc_trait_selection/traits/specialize/mod.rs @@ -130,7 +130,7 @@ pub(super) fn specializes(tcx: TyCtxt<'_>, (impl1_def_id, impl2_def_id): (DefId, // We determine whether there's a subset relationship by: // - // - skolemizing impl1, + // - replacing bound vars with placeholders in impl1, // - assuming the where clauses for impl1, // - instantiating impl2 with fresh inference variables, // - unifying, diff --git a/src/librustc_typeck/check/compare_method.rs b/src/librustc_typeck/check/compare_method.rs index b39cfcb3775..1d47e64630c 100644 --- a/src/librustc_typeck/check/compare_method.rs +++ b/src/librustc_typeck/check/compare_method.rs @@ -91,14 +91,14 @@ fn compare_predicate_entailment<'tcx>( // This code is best explained by example. Consider a trait: // - // trait Trait<'t,T> { - // fn method<'a,M>(t: &'t T, m: &'a M) -> Self; + // trait Trait<'t, T> { + // fn method<'a, M>(t: &'t T, m: &'a M) -> Self; // } // // And an impl: // // impl<'i, 'j, U> Trait<'j, &'i U> for Foo { - // fn method<'b,N>(t: &'j &'i U, m: &'b N) -> Foo; + // fn method<'b, N>(t: &'j &'i U, m: &'b N) -> Foo; // } // // We wish to decide if those two method types are compatible. @@ -116,9 +116,9 @@ fn compare_predicate_entailment<'tcx>( // regions (Note: but only early-bound regions, i.e., those // declared on the impl or used in type parameter bounds). // - // impl_to_skol_substs = {'i => 'i0, U => U0, N => N0 } + // impl_to_placeholder_substs = {'i => 'i0, U => U0, N => N0 } // - // Now we can apply skol_substs to the type of the impl method + // Now we can apply placeholder_substs to the type of the impl method // to yield a new function type in terms of our fresh, placeholder // types: // @@ -127,11 +127,11 @@ fn compare_predicate_entailment<'tcx>( // We now want to extract and substitute the type of the *trait* // method and compare it. To do so, we must create a compound // substitution by combining trait_to_impl_substs and - // impl_to_skol_substs, and also adding a mapping for the method + // impl_to_placeholder_substs, and also adding a mapping for the method // type parameters. We extend the mapping to also include // the method parameters. // - // trait_to_skol_substs = { T => &'i0 U0, Self => Foo, M => N0 } + // trait_to_placeholder_substs = { T => &'i0 U0, Self => Foo, M => N0 } // // Applying this to the trait method type yields: // @@ -145,20 +145,20 @@ fn compare_predicate_entailment<'tcx>( // satisfied by the implementation's method. // // We do this by creating a parameter environment which contains a - // substitution corresponding to impl_to_skol_substs. We then build - // trait_to_skol_substs and use it to convert the predicates contained + // substitution corresponding to impl_to_placeholder_substs. We then build + // trait_to_placeholder_substs and use it to convert the predicates contained // in the trait_m.generics to the placeholder form. // // Finally we register each of these predicates as an obligation in // a fresh FulfillmentCtxt, and invoke select_all_or_error. // Create mapping from impl to placeholder. - let impl_to_skol_substs = InternalSubsts::identity_for_item(tcx, impl_m.def_id); + let impl_to_placeholder_substs = InternalSubsts::identity_for_item(tcx, impl_m.def_id); // Create mapping from trait to placeholder. - let trait_to_skol_substs = - impl_to_skol_substs.rebase_onto(tcx, impl_m.container.id(), trait_to_impl_substs); - debug!("compare_impl_method: trait_to_skol_substs={:?}", trait_to_skol_substs); + let trait_to_placeholder_substs = + impl_to_placeholder_substs.rebase_onto(tcx, impl_m.container.id(), trait_to_impl_substs); + debug!("compare_impl_method: trait_to_placeholder_substs={:?}", trait_to_placeholder_substs); let impl_m_generics = tcx.generics_of(impl_m.def_id); let trait_m_generics = tcx.generics_of(trait_m.def_id); @@ -194,7 +194,7 @@ fn compare_predicate_entailment<'tcx>( // if all constraints hold. hybrid_preds .predicates - .extend(trait_m_predicates.instantiate_own(tcx, trait_to_skol_substs).predicates); + .extend(trait_m_predicates.instantiate_own(tcx, trait_to_placeholder_substs).predicates); // Construct trait parameter environment and then shift it into the placeholder viewpoint. // The key step here is to update the caller_bounds's predicates to be @@ -220,7 +220,7 @@ fn compare_predicate_entailment<'tcx>( let mut selcx = traits::SelectionContext::new(&infcx); - let impl_m_own_bounds = impl_m_predicates.instantiate_own(tcx, impl_to_skol_substs); + let impl_m_own_bounds = impl_m_predicates.instantiate_own(tcx, impl_to_placeholder_substs); let (impl_m_own_bounds, _) = infcx.replace_bound_vars_with_fresh_vars( impl_m_span, infer::HigherRankedType, @@ -261,7 +261,7 @@ fn compare_predicate_entailment<'tcx>( debug!("compare_impl_method: impl_fty={:?}", impl_fty); let trait_sig = tcx.liberate_late_bound_regions(impl_m.def_id, &tcx.fn_sig(trait_m.def_id)); - let trait_sig = trait_sig.subst(tcx, trait_to_skol_substs); + let trait_sig = trait_sig.subst(tcx, trait_to_placeholder_substs); let trait_sig = inh.normalize_associated_types_in(impl_m_span, impl_m_hir_id, param_env, &trait_sig); let trait_fty = tcx.mk_fn_ptr(ty::Binder::bind(trait_sig)); |