diff options
Diffstat (limited to 'compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs')
-rw-r--r-- | compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs | 42 |
1 files changed, 34 insertions, 8 deletions
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs index c09457e1d65..e84da2519ae 100644 --- a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs +++ b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs @@ -80,7 +80,7 @@ use rustc_middle::ty::{self, TyCtxt, TypeVisitableExt}; use rustc_span::Span; use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt; use rustc_trait_selection::traits::outlives_bounds::InferCtxtExt as _; -use rustc_trait_selection::traits::{self, translate_substs, wf, ObligationCtxt}; +use rustc_trait_selection::traits::{self, translate_substs_with_cause, wf, ObligationCtxt}; pub(super) fn check_min_specialization(tcx: TyCtxt<'_>, impl_def_id: LocalDefId) { if let Some(node) = parent_specialization_node(tcx, impl_def_id) { @@ -100,12 +100,19 @@ fn parent_specialization_node(tcx: TyCtxt<'_>, impl1_def_id: LocalDefId) -> Opti // Implementing a normal trait isn't a specialization. return None; } + if trait_def.is_marker { + // Overlapping marker implementations are not really specializations. + return None; + } Some(impl2_node) } /// Check that `impl1` is a sound specialization #[instrument(level = "debug", skip(tcx))] fn check_always_applicable(tcx: TyCtxt<'_>, impl1_def_id: LocalDefId, impl2_node: Node) { + let span = tcx.def_span(impl1_def_id); + check_has_items(tcx, impl1_def_id, impl2_node, span); + if let Some((impl1_substs, impl2_substs)) = get_impl_substs(tcx, impl1_def_id, impl2_node) { let impl2_def_id = impl2_node.def_id(); debug!(?impl2_def_id, ?impl2_substs); @@ -116,7 +123,6 @@ fn check_always_applicable(tcx: TyCtxt<'_>, impl1_def_id: LocalDefId, impl2_node unconstrained_parent_impl_substs(tcx, impl2_def_id, impl2_substs) }; - let span = tcx.def_span(impl1_def_id); check_constness(tcx, impl1_def_id, impl2_node, span); check_static_lifetimes(tcx, &parent_substs, span); check_duplicate_params(tcx, impl1_substs, &parent_substs, span); @@ -124,6 +130,13 @@ fn check_always_applicable(tcx: TyCtxt<'_>, impl1_def_id: LocalDefId, impl2_node } } +fn check_has_items(tcx: TyCtxt<'_>, impl1_def_id: LocalDefId, impl2_node: Node, span: Span) { + if let Node::Impl(impl2_id) = impl2_node && tcx.associated_item_def_ids(impl1_def_id).is_empty() { + let base_impl_span = tcx.def_span(impl2_id); + tcx.sess.emit_err(errors::EmptySpecialization { span, base_impl_span }); + } +} + /// Check that the specializing impl `impl1` is at least as const as the base /// impl `impl2` fn check_constness(tcx: TyCtxt<'_>, impl1_def_id: LocalDefId, impl2_node: Node, span: Span) { @@ -167,8 +180,21 @@ fn get_impl_substs( ocx.assumed_wf_types(param_env, tcx.def_span(impl1_def_id), impl1_def_id); let impl1_substs = InternalSubsts::identity_for_item(tcx, impl1_def_id); - let impl2_substs = - translate_substs(infcx, param_env, impl1_def_id.to_def_id(), impl1_substs, impl2_node); + let impl1_span = tcx.def_span(impl1_def_id); + let impl2_substs = translate_substs_with_cause( + infcx, + param_env, + impl1_def_id.to_def_id(), + impl1_substs, + impl2_node, + |_, span| { + traits::ObligationCause::new( + impl1_span, + impl1_def_id, + traits::ObligationCauseCode::BindingObligation(impl2_node.def_id(), span), + ) + }, + ); let errors = ocx.select_all_or_error(); if !errors.is_empty() { @@ -272,7 +298,7 @@ fn check_duplicate_params<'tcx>( if let (_, [duplicate, ..]) = base_params.partition_dedup() { let param = impl1_substs[duplicate.0 as usize]; tcx.sess - .struct_span_err(span, &format!("specializing impl repeats parameter `{}`", param)) + .struct_span_err(span, format!("specializing impl repeats parameter `{}`", param)) .emit(); } } @@ -464,7 +490,7 @@ fn check_specialization_on<'tcx>(tcx: TyCtxt<'tcx>, predicate: ty::Predicate<'tc tcx.sess .struct_span_err( span, - &format!( + format!( "cannot specialize on trait `{}`", tcx.def_path_str(trait_ref.def_id), ), @@ -479,7 +505,7 @@ fn check_specialization_on<'tcx>(tcx: TyCtxt<'tcx>, predicate: ty::Predicate<'tc tcx.sess .struct_span_err( span, - &format!("cannot specialize on associated type `{projection_ty} == {term}`",), + format!("cannot specialize on associated type `{projection_ty} == {term}`",), ) .emit(); } @@ -495,7 +521,7 @@ fn check_specialization_on<'tcx>(tcx: TyCtxt<'tcx>, predicate: ty::Predicate<'tc } _ => { tcx.sess - .struct_span_err(span, &format!("cannot specialize on predicate `{}`", predicate)) + .struct_span_err(span, format!("cannot specialize on predicate `{}`", predicate)) .emit(); } } |