diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src')
19 files changed, 404 insertions, 195 deletions
diff --git a/compiler/rustc_trait_selection/src/infer.rs b/compiler/rustc_trait_selection/src/infer.rs index 911cc0b88c4..fcf86da08f4 100644 --- a/compiler/rustc_trait_selection/src/infer.rs +++ b/compiler/rustc_trait_selection/src/infer.rs @@ -41,7 +41,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> { fn type_is_copy_modulo_regions(&self, param_env: ty::ParamEnv<'tcx>, ty: Ty<'tcx>) -> bool { let ty = self.resolve_vars_if_possible(ty); - if !(param_env, ty).needs_infer() { + if !(param_env, ty).has_infer() { return ty.is_copy_modulo_regions(self.tcx, param_env); } diff --git a/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs b/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs index 1a566e87dc8..996dc329dcb 100644 --- a/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs +++ b/compiler/rustc_trait_selection/src/solve/assembly/structural_traits.rs @@ -91,14 +91,15 @@ pub(in crate::solve) fn replace_erased_lifetimes_with_bound_vars<'tcx>( ) -> ty::Binder<'tcx, Ty<'tcx>> { debug_assert!(!ty.has_late_bound_regions()); let mut counter = 0; - let ty = tcx.fold_regions(ty, |mut r, current_depth| { - if let ty::ReErased = r.kind() { + let ty = tcx.fold_regions(ty, |r, current_depth| match r.kind() { + ty::ReErased => { let br = ty::BoundRegion { var: ty::BoundVar::from_u32(counter), kind: ty::BrAnon(None) }; counter += 1; - r = tcx.mk_re_late_bound(current_depth, br); + tcx.mk_re_late_bound(current_depth, br) } - r + // All free regions should be erased here. + r => bug!("unexpected region: {r:?}"), }); let bound_vars = tcx.mk_bound_variable_kinds_from_iter( (0..counter).map(|_| ty::BoundVariableKind::Region(ty::BrAnon(None))), diff --git a/compiler/rustc_trait_selection/src/solve/canonicalize.rs b/compiler/rustc_trait_selection/src/solve/canonicalize.rs index 976849696e3..ff4bff10cc8 100644 --- a/compiler/rustc_trait_selection/src/solve/canonicalize.rs +++ b/compiler/rustc_trait_selection/src/solve/canonicalize.rs @@ -69,7 +69,7 @@ impl<'a, 'tcx> Canonicalizer<'a, 'tcx> { }; let value = value.fold_with(&mut canonicalizer); - assert!(!value.needs_infer()); + assert!(!value.has_infer()); assert!(!value.has_placeholders()); let (max_universe, variables) = canonicalizer.finalize(); diff --git a/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs b/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs index bd52957d162..63a73f8d50d 100644 --- a/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs +++ b/compiler/rustc_trait_selection/src/solve/eval_ctxt.rs @@ -3,7 +3,8 @@ use rustc_infer::infer::at::ToTrace; use rustc_infer::infer::canonical::CanonicalVarValues; use rustc_infer::infer::type_variable::{TypeVariableOrigin, TypeVariableOriginKind}; use rustc_infer::infer::{ - DefineOpaqueTypes, InferCtxt, InferOk, LateBoundRegionConversionTime, TyCtxtInferExt, + DefineOpaqueTypes, InferCtxt, InferOk, LateBoundRegionConversionTime, RegionVariableOrigin, + TyCtxtInferExt, }; use rustc_infer::traits::query::NoSolution; use rustc_infer::traits::ObligationCause; @@ -223,18 +224,20 @@ impl<'a, 'tcx> EvalCtxt<'a, 'tcx> { { debug!("rerunning goal to check result is stable"); let (_orig_values, canonical_goal) = self.canonicalize_goal(goal); - let canonical_response = + let new_canonical_response = EvalCtxt::evaluate_canonical_goal(self.tcx(), self.search_graph, canonical_goal)?; - if !canonical_response.value.var_values.is_identity() { + if !new_canonical_response.value.var_values.is_identity() { bug!( "unstable result: re-canonicalized goal={canonical_goal:#?} \ - response={canonical_response:#?}" + first_response={canonical_response:#?} \ + second_response={new_canonical_response:#?}" ); } - if certainty != canonical_response.value.certainty { + if certainty != new_canonical_response.value.certainty { bug!( "unstable certainty: {certainty:#?} re-canonicalized goal={canonical_goal:#?} \ - response={canonical_response:#?}" + first_response={canonical_response:#?} \ + second_response={new_canonical_response:#?}" ); } } @@ -434,6 +437,10 @@ impl<'tcx> EvalCtxt<'_, 'tcx> { }) } + pub(super) fn next_region_infer(&self) -> ty::Region<'tcx> { + self.infcx.next_region_var(RegionVariableOrigin::MiscVariable(DUMMY_SP)) + } + pub(super) fn next_const_infer(&self, ty: Ty<'tcx>) -> ty::Const<'tcx> { self.infcx.next_const_var( ty, diff --git a/compiler/rustc_trait_selection/src/solve/eval_ctxt/canonical.rs b/compiler/rustc_trait_selection/src/solve/eval_ctxt/canonical.rs index 226d29687e3..67ad7fb4bd2 100644 --- a/compiler/rustc_trait_selection/src/solve/eval_ctxt/canonical.rs +++ b/compiler/rustc_trait_selection/src/solve/eval_ctxt/canonical.rs @@ -16,7 +16,7 @@ use rustc_infer::infer::canonical::query_response::make_query_region_constraints use rustc_infer::infer::canonical::CanonicalVarValues; use rustc_infer::infer::canonical::{CanonicalExt, QueryRegionConstraints}; use rustc_middle::traits::query::NoSolution; -use rustc_middle::traits::solve::{ExternalConstraints, ExternalConstraintsData}; +use rustc_middle::traits::solve::{ExternalConstraints, ExternalConstraintsData, MaybeCause}; use rustc_middle::ty::{self, BoundVar, GenericArgKind}; use rustc_span::DUMMY_SP; use std::iter; @@ -60,9 +60,27 @@ impl<'tcx> EvalCtxt<'_, 'tcx> { let certainty = certainty.unify_with(goals_certainty); - let external_constraints = self.compute_external_query_constraints()?; + let response = match certainty { + Certainty::Yes | Certainty::Maybe(MaybeCause::Ambiguity) => { + let external_constraints = self.compute_external_query_constraints()?; + Response { var_values: self.var_values, external_constraints, certainty } + } + Certainty::Maybe(MaybeCause::Overflow) => { + // If we have overflow, it's probable that we're substituting a type + // into itself infinitely and any partial substitutions in the query + // response are probably not useful anyways, so just return an empty + // query response. + // + // This may prevent us from potentially useful inference, e.g. + // 2 candidates, one ambiguous and one overflow, which both + // have the same inference constraints. + // + // Changing this to retain some constraints in the future + // won't be a breaking change, so this is good enough for now. + return Ok(self.make_ambiguous_response_no_constraints(MaybeCause::Overflow)); + } + }; - let response = Response { var_values: self.var_values, external_constraints, certainty }; let canonical = Canonicalizer::canonicalize( self.infcx, CanonicalizeMode::Response { max_input_universe: self.max_input_universe }, @@ -72,6 +90,40 @@ impl<'tcx> EvalCtxt<'_, 'tcx> { Ok(canonical) } + /// Constructs a totally unconstrained, ambiguous response to a goal. + /// + /// Take care when using this, since often it's useful to respond with + /// ambiguity but return constrained variables to guide inference. + pub(in crate::solve) fn make_ambiguous_response_no_constraints( + &self, + maybe_cause: MaybeCause, + ) -> CanonicalResponse<'tcx> { + let unconstrained_response = Response { + var_values: CanonicalVarValues { + var_values: self.tcx().mk_substs_from_iter(self.var_values.var_values.iter().map( + |arg| -> ty::GenericArg<'tcx> { + match arg.unpack() { + GenericArgKind::Lifetime(_) => self.next_region_infer().into(), + GenericArgKind::Type(_) => self.next_ty_infer().into(), + GenericArgKind::Const(ct) => self.next_const_infer(ct.ty()).into(), + } + }, + )), + }, + external_constraints: self + .tcx() + .mk_external_constraints(ExternalConstraintsData::default()), + certainty: Certainty::Maybe(maybe_cause), + }; + + Canonicalizer::canonicalize( + self.infcx, + CanonicalizeMode::Response { max_input_universe: self.max_input_universe }, + &mut Default::default(), + unconstrained_response, + ) + } + #[instrument(level = "debug", skip(self), ret)] fn compute_external_query_constraints(&self) -> Result<ExternalConstraints<'tcx>, NoSolution> { // Cannot use `take_registered_region_obligations` as we may compute the response diff --git a/compiler/rustc_trait_selection/src/solve/mod.rs b/compiler/rustc_trait_selection/src/solve/mod.rs index 19bcbd46144..d94679fef28 100644 --- a/compiler/rustc_trait_selection/src/solve/mod.rs +++ b/compiler/rustc_trait_selection/src/solve/mod.rs @@ -340,17 +340,17 @@ impl<'tcx> EvalCtxt<'_, 'tcx> { if responses.is_empty() { return Err(NoSolution); } - let certainty = responses.iter().fold(Certainty::AMBIGUOUS, |certainty, response| { - certainty.unify_with(response.value.certainty) - }); - - let response = self.evaluate_added_goals_and_make_canonical_response(certainty); - if let Ok(response) = response { - assert!(response.has_no_inference_or_external_constraints()); - Ok(response) - } else { - bug!("failed to make floundered response: {responses:?}"); - } + + let Certainty::Maybe(maybe_cause) = responses.iter().fold( + Certainty::AMBIGUOUS, + |certainty, response| { + certainty.unify_with(response.value.certainty) + }, + ) else { + bug!("expected flounder response to be ambiguous") + }; + + Ok(self.make_ambiguous_response_no_constraints(maybe_cause)) } } diff --git a/compiler/rustc_trait_selection/src/solve/trait_goals.rs b/compiler/rustc_trait_selection/src/solve/trait_goals.rs index 8e7097ce4a7..c97473e6241 100644 --- a/compiler/rustc_trait_selection/src/solve/trait_goals.rs +++ b/compiler/rustc_trait_selection/src/solve/trait_goals.rs @@ -86,8 +86,9 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ) -> QueryResult<'tcx> { if let Some(poly_trait_pred) = assumption.to_opt_poly_trait_pred() && poly_trait_pred.def_id() == goal.predicate.def_id() + && poly_trait_pred.polarity() == goal.predicate.polarity { - // FIXME: Constness and polarity + // FIXME: Constness ecx.probe(|ecx| { let assumption_trait_pred = ecx.instantiate_binder_with_infer(poly_trait_pred); @@ -111,6 +112,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ) -> QueryResult<'tcx> { if let Some(poly_trait_pred) = assumption.to_opt_poly_trait_pred() && poly_trait_pred.def_id() == goal.predicate.def_id() + && poly_trait_pred.polarity() == goal.predicate.polarity { // FIXME: Constness and polarity ecx.probe(|ecx| { @@ -147,6 +149,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + if let Some(result) = ecx.disqualify_auto_trait_candidate_due_to_possible_impl(goal) { return result; } @@ -161,6 +167,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + let tcx = ecx.tcx(); ecx.probe(|ecx| { @@ -176,6 +186,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + ecx.probe_and_evaluate_goal_for_constituent_tys( goal, structural_traits::instantiate_constituent_tys_for_sized_trait, @@ -186,6 +200,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + ecx.probe_and_evaluate_goal_for_constituent_tys( goal, structural_traits::instantiate_constituent_tys_for_copy_clone_trait, @@ -196,6 +214,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + if goal.predicate.self_ty().has_non_region_infer() { return ecx.evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS); } @@ -217,6 +239,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + if let ty::FnPtr(..) = goal.predicate.self_ty().kind() { ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) } else { @@ -229,6 +255,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { goal: Goal<'tcx, Self>, goal_kind: ty::ClosureKind, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + let tcx = ecx.tcx(); let tupled_inputs_and_output = match structural_traits::extract_tupled_inputs_and_output_from_callable( @@ -259,6 +289,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + if let ty::Tuple(..) = goal.predicate.self_ty().kind() { ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) } else { @@ -268,8 +302,12 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { fn consider_builtin_pointee_candidate( ecx: &mut EvalCtxt<'_, 'tcx>, - _goal: Goal<'tcx, Self>, + goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) } @@ -277,6 +315,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + let ty::Generator(def_id, _, _) = *goal.predicate.self_ty().kind() else { return Err(NoSolution); }; @@ -297,6 +339,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + let self_ty = goal.predicate.self_ty(); let ty::Generator(def_id, substs, _) = *self_ty.kind() else { return Err(NoSolution); @@ -326,6 +372,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + let tcx = ecx.tcx(); let a_ty = goal.predicate.self_ty(); let b_ty = goal.predicate.trait_ref.substs.type_at(1); @@ -447,6 +497,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> Vec<CanonicalResponse<'tcx>> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return vec![]; + } + let tcx = ecx.tcx(); let a_ty = goal.predicate.self_ty(); @@ -521,8 +575,12 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { fn consider_builtin_discriminant_kind_candidate( ecx: &mut EvalCtxt<'_, 'tcx>, - _goal: Goal<'tcx, Self>, + goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + // `DiscriminantKind` is automatically implemented for every type. ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes) } @@ -531,6 +589,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + if !goal.param_env.is_const() { // `Destruct` is automatically implemented for every type in // non-const environments. @@ -545,6 +607,10 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> { ecx: &mut EvalCtxt<'_, 'tcx>, goal: Goal<'tcx, Self>, ) -> QueryResult<'tcx> { + if goal.predicate.polarity != ty::ImplPolarity::Positive { + return Err(NoSolution); + } + // `rustc_transmute` does not have support for type or const params if goal.has_non_region_placeholders() { return Err(NoSolution); diff --git a/compiler/rustc_trait_selection/src/traits/coherence.rs b/compiler/rustc_trait_selection/src/traits/coherence.rs index 20c2605f219..b7690f79933 100644 --- a/compiler/rustc_trait_selection/src/traits/coherence.rs +++ b/compiler/rustc_trait_selection/src/traits/coherence.rs @@ -582,7 +582,7 @@ fn orphan_check_trait_ref<'tcx>( trait_ref: ty::TraitRef<'tcx>, in_crate: InCrate, ) -> Result<(), OrphanCheckErr<'tcx>> { - if trait_ref.needs_infer() && trait_ref.needs_subst() { + if trait_ref.has_infer() && trait_ref.has_param() { bug!( "can't orphan check a trait ref with both params and inference variables {:?}", trait_ref diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs index ce187fbdf84..69b3c1e7eff 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs @@ -271,7 +271,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> { let underscores = vec!["_"; expected_args.len()].join(", "); err.span_suggestion_verbose( closure_arg_span.unwrap_or(found_span), - &format!( + format!( "consider changing the closure to take and ignore the expected argument{}", pluralize!(expected_args.len()) ), @@ -575,7 +575,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { Limit(0) => Limit(2), limit => limit * 2, }; - err.help(&format!( + err.help(format!( "consider increasing the recursion limit by adding a \ `#![recursion_limit = \"{}\"]` attribute to your crate (`{}`)", suggested_limit, @@ -737,7 +737,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { if is_try_conversion && let Some(ret_span) = self.return_type_span(&obligation) { err.span_label( ret_span, - &format!( + format!( "expected `{}` because of this", trait_ref.skip_binder().self_ty() ), @@ -780,7 +780,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { err.emit(); return; } - if let Some(ref s) = label { + if let Some(s) = label { // If it has a custom `#[rustc_on_unimplemented]` // error message, let's display it as the label! err.span_label(span, s); @@ -788,7 +788,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { // When the self type is a type param We don't need to "the trait // `std::marker::Sized` is not implemented for `T`" as we will point // at the type param with a label to suggest constraining it. - err.help(&explanation); + err.help(explanation); } } else if let Some(custom_explanation) = safe_transmute_explanation { err.span_label(span, custom_explanation); @@ -811,13 +811,13 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { ); if let Some((msg, span)) = type_def { - err.span_label(span, &msg); + err.span_label(span, msg); } - if let Some(ref s) = note { + if let Some(s) = note { // If it has a custom `#[rustc_on_unimplemented]` note, let's display it - err.note(s.as_str()); + err.note(s); } - if let Some(ref s) = parent_label { + if let Some(s) = parent_label { let body = obligation.cause.body_id; err.span_label(tcx.def_span(body), s); } @@ -1028,7 +1028,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { // which bounds actually failed to hold. self.tcx.sess.struct_span_err( span, - &format!("the type `{}` is not well-formed", ty), + format!("the type `{}` is not well-formed", ty), ) } } @@ -1071,7 +1071,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { ty::PredicateKind::Clause(ty::Clause::ConstArgHasType(ct, ty)) => { let mut diag = self.tcx.sess.struct_span_err( span, - &format!("the constant `{}` is not of type `{}`", ct, ty), + format!("the constant `{}` is not of type `{}`", ct, ty), ); self.note_type_err( &mut diag, @@ -1835,7 +1835,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { candidates.sort(); candidates.dedup(); let end = if candidates.len() <= 9 { candidates.len() } else { 8 }; - err.help(&format!( + err.help(format!( "the following {other}types implement trait `{}`:{}{}", trait_ref.print_only_trait_path(), candidates[..end].join(""), @@ -2026,7 +2026,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { "perhaps two different versions of crate `{}` are being used?", trait_crate ); - err.note(&crate_msg); + err.note(crate_msg); suggested = true; } suggested @@ -2158,7 +2158,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { err.cancel(); return; } - err.note(&format!("cannot satisfy `{}`", predicate)); + err.note(format!("cannot satisfy `{}`", predicate)); let impl_candidates = self.find_similar_impl_candidates( predicate.to_opt_poly_trait_pred().unwrap(), ); @@ -2178,7 +2178,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { err.cancel(); return; } - err.note(&format!("cannot satisfy `{}`", predicate)); + err.note(format!("cannot satisfy `{}`", predicate)); } } @@ -2223,9 +2223,9 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { err.cancel(); err = self.tcx.sess.struct_span_err_with_code( span, - &format!( + format!( "cannot {verb} associated {noun} on trait without specifying the corresponding `impl` type", - ), + ), rustc_errors::error_code!(E0790), ); @@ -2332,7 +2332,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { ErrorCode::E0284, true, ); - err.note(&format!("cannot satisfy `{}`", predicate)); + err.note(format!("cannot satisfy `{}`", predicate)); err } else { // If we can't find a substitution, just print a generic error @@ -2343,7 +2343,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { "type annotations needed: cannot satisfy `{}`", predicate, ); - err.span_label(span, &format!("cannot satisfy `{}`", predicate)); + err.span_label(span, format!("cannot satisfy `{}`", predicate)); err } } @@ -2371,7 +2371,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { "type annotations needed: cannot satisfy `{}`", predicate, ); - err.span_label(span, &format!("cannot satisfy `{}`", predicate)); + err.span_label(span, format!("cannot satisfy `{}`", predicate)); err } } @@ -2386,7 +2386,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { "type annotations needed: cannot satisfy `{}`", predicate, ); - err.span_label(span, &format!("cannot satisfy `{}`", predicate)); + err.span_label(span, format!("cannot satisfy `{}`", predicate)); err } }; @@ -2459,13 +2459,13 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { match (spans.len(), crates.len(), crate_names.len()) { (0, 0, 0) => { - err.note(&format!("cannot satisfy `{}`", predicate)); + err.note(format!("cannot satisfy `{}`", predicate)); } (0, _, 1) => { - err.note(&format!("{} in the `{}` crate{}", msg, crates[0], post,)); + err.note(format!("{} in the `{}` crate{}", msg, crates[0], post,)); } (0, _, _) => { - err.note(&format!( + err.note(format!( "{} in the following crates: {}{}", msg, crate_names.join(", "), @@ -2474,19 +2474,17 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { } (_, 0, 0) => { let span: MultiSpan = spans.into(); - err.span_note(span, &msg); + err.span_note(span, msg); } (_, 1, 1) => { let span: MultiSpan = spans.into(); - err.span_note(span, &msg); - err.note( - &format!("and another `impl` found in the `{}` crate{}", crates[0], post,), - ); + err.span_note(span, msg); + err.note(format!("and another `impl` found in the `{}` crate{}", crates[0], post,)); } _ => { let span: MultiSpan = spans.into(); - err.span_note(span, &msg); - err.note(&format!( + err.span_note(span, msg); + err.note(format!( "and more `impl`s found in the following crates: {}{}", crate_names.join(", "), post, @@ -2657,7 +2655,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { } err.span_help( multispan, - &format!( + format!( "you could relax the implicit `Sized` bound on `{T}` if it were \ used through indirection like `&{T}` or `Box<{T}>`", T = param.name.ident(), @@ -2882,7 +2880,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { .fn_trait_kind_from_def_id(trait_ref.def_id()) .expect("expected to map DefId to ClosureKind"); if !implemented_kind.extends(selected_kind) { - err.note(&format!( + err.note(format!( "`{}` implements `{}`, but it must implement `{}`, which is more general", trait_ref.skip_binder().self_ty(), implemented_kind, @@ -2899,7 +2897,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { if expected.len() != given.len() { // Note number of types that were expected and given err.note( - &format!( + format!( "expected a closure taking {} argument{}, but one taking {} argument{} was given", given.len(), pluralize!(given.len()), @@ -2942,7 +2940,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { unsatisfied_const = UnsatisfiedConst(true); err.span_note( span, - &format!( + format!( "the trait `{}` is implemented for `{}`, \ but that implementation is not `const`", non_const_predicate.print_modifiers_and_trait_path(), @@ -3171,7 +3169,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { let mut err = self.tcx.sess.struct_span_err(span, "unconstrained generic constant"); let const_span = self.tcx.def_span(uv.def); match self.tcx.sess.source_map().span_to_snippet(const_span) { - Ok(snippet) => err.help(&format!( + Ok(snippet) => err.help(format!( "try adding a `where` bound using this expression: `where [(); {}]:`", snippet )), diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs index c969e5d4975..08220c4fe9f 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs @@ -515,7 +515,7 @@ fn suggest_restriction<'tcx>( err.span_suggestion_verbose( sp, - &format!("consider further restricting {}", msg), + format!("consider further restricting {}", msg), suggestion, Applicability::MachineApplicable, ); @@ -964,7 +964,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { // a more general note. err.span_suggestion_verbose( obligation.cause.span.shrink_to_hi(), - &msg, + msg, format!("({args})"), Applicability::HasPlaceholders, ); @@ -994,7 +994,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { } _ => return false, }; - err.help(&format!("{msg}: `{name}({args})`")); + err.help(format!("{msg}: `{name}({args})`")); } true } @@ -1334,7 +1334,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { let msg = format!("the trait bound `{}` is not satisfied", old_pred); if has_custom_message { - err.note(&msg); + err.note(msg); } else { err.message = vec![(rustc_errors::DiagnosticMessage::Str(msg), Style::NoStyle)]; @@ -1358,7 +1358,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { } else { let is_mut = mut_ref_self_ty_satisfies_pred || ref_inner_ty_mut; let sugg_prefix = format!("&{}", if is_mut { "mut " } else { "" }); - let sugg_msg = &format!( + let sugg_msg = format!( "consider{} borrowing here", if is_mut { " mutably" } else { "" } ); @@ -1452,7 +1452,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { err.span_suggestion( obligation.cause.span.shrink_to_lo(), - &format!( + format!( "consider borrowing the value, since `&{self_ty}` can be coerced into `{object_ty}`" ), "&", @@ -1505,7 +1505,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { }; err.multipart_suggestion_verbose( - &msg, + msg, suggestions, Applicability::MachineApplicable, ); @@ -1583,55 +1583,68 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { } fn suggest_remove_await(&self, obligation: &PredicateObligation<'tcx>, err: &mut Diagnostic) { - let span = obligation.cause.span; - - if let ObligationCauseCode::AwaitableExpr(hir_id) = obligation.cause.code().peel_derives() { - let hir = self.tcx.hir(); - if let Some(hir::Node::Expr(expr)) = hir_id.and_then(|hir_id| hir.find(hir_id)) { - // FIXME: use `obligation.predicate.kind()...trait_ref.self_ty()` to see if we have `()` - // and if not maybe suggest doing something else? If we kept the expression around we - // could also check if it is an fn call (very likely) and suggest changing *that*, if - // it is from the local crate. + let hir = self.tcx.hir(); + if let ObligationCauseCode::AwaitableExpr(Some(hir_id)) = obligation.cause.code().peel_derives() + && let hir::Node::Expr(expr) = hir.get(*hir_id) + { + // FIXME: use `obligation.predicate.kind()...trait_ref.self_ty()` to see if we have `()` + // and if not maybe suggest doing something else? If we kept the expression around we + // could also check if it is an fn call (very likely) and suggest changing *that*, if + // it is from the local crate. + + // use nth(1) to skip one layer of desugaring from `IntoIter::into_iter` + if let Some((_, hir::Node::Expr(await_expr))) = hir.parent_iter(*hir_id).nth(1) + && let Some(expr_span) = expr.span.find_ancestor_inside(await_expr.span) + { + let removal_span = self.tcx + .sess + .source_map() + .span_extend_while(expr_span, char::is_whitespace) + .unwrap_or(expr_span) + .shrink_to_hi() + .to(await_expr.span.shrink_to_hi()); err.span_suggestion( - span, + removal_span, "remove the `.await`", "", Applicability::MachineApplicable, ); - // FIXME: account for associated `async fn`s. - if let hir::Expr { span, kind: hir::ExprKind::Call(base, _), .. } = expr { - if let ty::PredicateKind::Clause(ty::Clause::Trait(pred)) = - obligation.predicate.kind().skip_binder() + } else { + err.span_label(obligation.cause.span, "remove the `.await`"); + } + // FIXME: account for associated `async fn`s. + if let hir::Expr { span, kind: hir::ExprKind::Call(base, _), .. } = expr { + if let ty::PredicateKind::Clause(ty::Clause::Trait(pred)) = + obligation.predicate.kind().skip_binder() + { + err.span_label(*span, format!("this call returns `{}`", pred.self_ty())); + } + if let Some(typeck_results) = &self.typeck_results + && let ty = typeck_results.expr_ty_adjusted(base) + && let ty::FnDef(def_id, _substs) = ty.kind() + && let Some(hir::Node::Item(hir::Item { ident, span, vis_span, .. })) = + hir.get_if_local(*def_id) { - err.span_label(*span, &format!("this call returns `{}`", pred.self_ty())); - } - if let Some(typeck_results) = &self.typeck_results - && let ty = typeck_results.expr_ty_adjusted(base) - && let ty::FnDef(def_id, _substs) = ty.kind() - && let Some(hir::Node::Item(hir::Item { ident, span, vis_span, .. })) = - hir.get_if_local(*def_id) - { - let msg = format!( - "alternatively, consider making `fn {}` asynchronous", - ident + let msg = format!( + "alternatively, consider making `fn {}` asynchronous", + ident + ); + if vis_span.is_empty() { + err.span_suggestion_verbose( + span.shrink_to_lo(), + msg, + "async ", + Applicability::MaybeIncorrect, + ); + } else { + err.span_suggestion_verbose( + vis_span.shrink_to_hi(), + msg, + " async", + Applicability::MaybeIncorrect, ); - if vis_span.is_empty() { - err.span_suggestion_verbose( - span.shrink_to_lo(), - &msg, - "async ", - Applicability::MaybeIncorrect, - ); - } else { - err.span_suggestion_verbose( - vis_span.shrink_to_hi(), - &msg, - " async", - Applicability::MaybeIncorrect, - ); - } } - } + } } } } @@ -1704,7 +1717,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { Applicability::MachineApplicable, ); } else { - err.note(&format!( + err.note(format!( "`{}` is implemented for `{:?}`, but not for `{:?}`", trait_pred.print_modifiers_and_trait_path(), suggested_ty, @@ -1741,7 +1754,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { { err.span_label( expr.span, - &format!( + format!( "this expression has type `{}`, which implements `{}`", ty, trait_pred.print_modifiers_and_trait_path() @@ -1933,7 +1946,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { // Suggest `-> impl Trait`. err.span_suggestion( ret_ty.span, - &format!( + format!( "use `impl {1}` as the return type, as all return paths are of type `{}`, \ which implements `{1}`", last_ty, trait_obj, @@ -1968,13 +1981,13 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { } else { // This is currently not possible to trigger because E0038 takes precedence, but // leave it in for completeness in case anything changes in an earlier stage. - err.note(&format!( + err.note(format!( "if trait `{}` were object-safe, you could return a trait object", trait_obj, )); } err.note(trait_obj_msg); - err.note(&format!( + err.note(format!( "if all the returned values were of the same type you could use `impl {}` as the \ return type", trait_obj, @@ -2014,7 +2027,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { } else { err.span_label( expr.span, - &format!("this returned value is of type `{}`", ty), + format!("this returned value is of type `{}`", ty), ); } } @@ -2164,7 +2177,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { ) { if let Some(assoc_item) = self.tcx.opt_associated_item(item_def_id) { if let ty::AssocKind::Const | ty::AssocKind::Type = assoc_item.kind { - err.note(&format!( + err.note(format!( "{}s cannot be accessed directly on a `trait`, they can only be \ accessed through a specific `impl`", self.tcx.def_kind_descr(assoc_item.kind.as_def_kind(), item_def_id) @@ -2594,7 +2607,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { } err.span_note( span, - &format!( + format!( "{} {} as this value is used across {}", future_or_generator, trait_explanation, an_await_or_yield ), @@ -2615,7 +2628,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { ); err.span_note( span, - &format!( + format!( "future {not_trait} as it awaits another future which {not_trait}", not_trait = trait_explanation ), @@ -2717,7 +2730,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { let mut span = MultiSpan::from_span(upvar_span); span.push_span_label(upvar_span, span_label); - err.span_note(span, &span_note); + err.span_note(span, span_note); } } @@ -2781,15 +2794,15 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { err.note("only the last element of a tuple may have a dynamically sized type"); } ObligationCauseCode::ProjectionWf(data) => { - err.note(&format!("required so that the projection `{data}` is well-formed")); + err.note(format!("required so that the projection `{data}` is well-formed")); } ObligationCauseCode::ReferenceOutlivesReferent(ref_ty) => { - err.note(&format!( + err.note(format!( "required so that reference `{ref_ty}` does not outlive its referent" )); } ObligationCauseCode::ObjectTypeBound(object_ty, region) => { - err.note(&format!( + err.note(format!( "required so that the lifetime bound of `{}` for `{}` is satisfied", region, object_ty, )); @@ -2825,9 +2838,9 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { if span.is_visible(sm) { let msg = format!("required by this bound in `{short_item_name}`"); multispan.push_span_label(span, msg); - err.span_note(multispan, &descr); + err.span_note(multispan, descr); } else { - err.span_note(tcx.def_span(item_def_id), &descr); + err.span_note(tcx.def_span(item_def_id), descr); } } ObligationCauseCode::ObjectCastObligation(concrete_ty, object_ty) => { @@ -2835,24 +2848,24 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { self.tcx.short_ty_string(self.resolve_vars_if_possible(concrete_ty)); let (object_ty, object_file) = self.tcx.short_ty_string(self.resolve_vars_if_possible(object_ty)); - err.note(&with_forced_trimmed_paths!(format!( + err.note(with_forced_trimmed_paths!(format!( "required for the cast from `{concrete_ty}` to the object type `{object_ty}`", ))); if let Some(file) = concrete_file { - err.note(&format!( + err.note(format!( "the full name for the casted type has been written to '{}'", file.display(), )); } if let Some(file) = object_file { - err.note(&format!( + err.note(format!( "the full name for the object type has been written to '{}'", file.display(), )); } } ObligationCauseCode::Coercion { source: _, target } => { - err.note(&format!("required by cast to type `{}`", self.ty_to_string(target))); + err.note(format!("required by cast to type `{}`", self.ty_to_string(target))); } ObligationCauseCode::RepeatElementCopy { is_const_fn } => { err.note( @@ -3055,8 +3068,8 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { )); match ty.kind() { ty::Adt(def, _) => match self.tcx.opt_item_ident(def.did()) { - Some(ident) => err.span_note(ident.span, &msg), - None => err.note(&msg), + Some(ident) => err.span_note(ident.span, msg), + None => err.note(msg), }, ty::Alias(ty::Opaque, ty::AliasTy { def_id, .. }) => { // If the previous type is async fn, this is the future generated by the body of an async function. @@ -3077,7 +3090,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { { break 'print; } - err.span_note(self.tcx.def_span(def_id), &msg) + err.span_note(self.tcx.def_span(def_id), msg) } ty::GeneratorWitness(bound_tys) => { use std::fmt::Write; @@ -3113,7 +3126,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { let kind = tcx.generator_kind(def_id).unwrap().descr(); err.span_note( sp, - with_forced_trimmed_paths!(&format!( + with_forced_trimmed_paths!(format!( "required because it's used within this {kind}", )), ) @@ -3123,7 +3136,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { "required because it's used within this closure", ), ty::Str => err.note("`str` is considered to contain a `[u8]` slice for auto trait purposes"), - _ => err.note(&msg), + _ => err.note(msg), }; } } @@ -3177,7 +3190,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { // FIXME: we should do something else so that it works even on crate foreign // auto traits. is_auto_trait = matches!(is_auto, hir::IsAuto::Yes); - err.span_note(ident.span, &msg); + err.span_note(ident.span, msg); } Some(Node::Item(hir::Item { kind: hir::ItemKind::Impl(hir::Impl { of_trait, self_ty, .. }), @@ -3206,15 +3219,15 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { "unsatisfied trait bound introduced here", ); } - err.span_note(spans, &msg); + err.span_note(spans, msg); } _ => { - err.note(&msg); + err.note(msg); } }; if let Some(file) = file { - err.note(&format!( + err.note(format!( "the full type name has been written to '{}'", file.display(), )); @@ -3254,19 +3267,19 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { parent_trait_pred = child_trait_pred; } if count > 0 { - err.note(&format!( + err.note(format!( "{} redundant requirement{} hidden", count, pluralize!(count) )); let (self_ty, file) = self.tcx.short_ty_string(parent_trait_pred.skip_binder().self_ty()); - err.note(&format!( + err.note(format!( "required for `{self_ty}` to implement `{}`", parent_trait_pred.print_modifiers_and_trait_path() )); if let Some(file) = file { - err.note(&format!( + err.note(format!( "the full type name has been written to '{}'", file.display(), )); @@ -3347,7 +3360,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { { assoc_span.push_span_label(ident.span, "in this trait"); } - err.span_note(assoc_span, &msg); + err.span_note(assoc_span, msg); } ObligationCauseCode::TrivialBound => { err.help("see issue #48214"); @@ -3503,7 +3516,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { if can_derive { err.span_suggestion_verbose( self.tcx.def_span(adt.did()).shrink_to_lo(), - &format!( + format!( "consider annotating `{}` with `#[derive({})]`", trait_pred.skip_binder().self_ty(), diagnostic_name, @@ -3890,7 +3903,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { .map(|trait_ref| trait_ref.trait_ref.self_ty()) .find(|t| is_slice(*t)) { - let msg = &format!("convert the array to a `{}` slice instead", slice_ty); + let msg = format!("convert the array to a `{}` slice instead", slice_ty); if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(span) { let mut suggestions = vec![]; @@ -4111,7 +4124,7 @@ fn suggest_trait_object_return_type_alternatives( ) { err.span_suggestion( ret_ty, - &format!( + format!( "use `impl {}` as the return type if all return paths have the same type but you \ want to expose only the trait in the signature", trait_obj, @@ -4121,7 +4134,7 @@ fn suggest_trait_object_return_type_alternatives( ); if is_object_safe { err.multipart_suggestion( - &format!( + format!( "use a boxed trait object if all return paths implement trait `{}`", trait_obj, ), diff --git a/compiler/rustc_trait_selection/src/traits/misc.rs b/compiler/rustc_trait_selection/src/traits/misc.rs index 63949843aed..2210ef975e6 100644 --- a/compiler/rustc_trait_selection/src/traits/misc.rs +++ b/compiler/rustc_trait_selection/src/traits/misc.rs @@ -2,13 +2,14 @@ use crate::traits::{self, ObligationCause, ObligationCtxt}; +use hir::LangItem; use rustc_data_structures::fx::FxIndexSet; use rustc_hir as hir; use rustc_infer::infer::canonical::Canonical; use rustc_infer::infer::{RegionResolutionError, TyCtxtInferExt}; use rustc_infer::traits::query::NoSolution; use rustc_infer::{infer::outlives::env::OutlivesEnvironment, traits::FulfillmentError}; -use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt, TypeVisitableExt}; +use rustc_middle::ty::{self, AdtDef, GenericArg, List, ParamEnv, Ty, TyCtxt, TypeVisitableExt}; use rustc_span::DUMMY_SP; use super::outlives_bounds::InferCtxtExt; @@ -19,6 +20,11 @@ pub enum CopyImplementationError<'tcx> { HasDestructor, } +pub enum ConstParamTyImplementationError<'tcx> { + InfrigingFields(Vec<(&'tcx ty::FieldDef, Ty<'tcx>, InfringingFieldsReason<'tcx>)>), + NotAnAdtOrBuiltinAllowed, +} + pub enum InfringingFieldsReason<'tcx> { Fulfill(Vec<FulfillmentError<'tcx>>), Regions(Vec<RegionResolutionError<'tcx>>), @@ -27,7 +33,10 @@ pub enum InfringingFieldsReason<'tcx> { /// Checks that the fields of the type (an ADT) all implement copy. /// /// If fields don't implement copy, return an error containing a list of -/// those violating fields. If it's not an ADT, returns `Err(NotAnAdt)`. +/// those violating fields. +/// +/// If it's not an ADT, int ty, `bool`, float ty, `char`, raw pointer, `!`, +/// a reference or an array returns `Err(NotAnAdt)`. pub fn type_allowed_to_implement_copy<'tcx>( tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>, @@ -47,12 +56,82 @@ pub fn type_allowed_to_implement_copy<'tcx>( | ty::Ref(_, _, hir::Mutability::Not) | ty::Array(..) => return Ok(()), - ty::Adt(adt, substs) => (adt, substs), + &ty::Adt(adt, substs) => (adt, substs), _ => return Err(CopyImplementationError::NotAnAdt), }; - let copy_def_id = tcx.require_lang_item(hir::LangItem::Copy, Some(parent_cause.span)); + all_fields_implement_trait( + tcx, + param_env, + self_type, + adt, + substs, + parent_cause, + hir::LangItem::Copy, + ) + .map_err(CopyImplementationError::InfringingFields)?; + + if adt.has_dtor(tcx) { + return Err(CopyImplementationError::HasDestructor); + } + + Ok(()) +} + +/// Checks that the fields of the type (an ADT) all implement `ConstParamTy`. +/// +/// If fields don't implement `ConstParamTy`, return an error containing a list of +/// those violating fields. +/// +/// If it's not an ADT, int ty, `bool` or `char`, returns `Err(NotAnAdtOrBuiltinAllowed)`. +pub fn type_allowed_to_implement_const_param_ty<'tcx>( + tcx: TyCtxt<'tcx>, + param_env: ty::ParamEnv<'tcx>, + self_type: Ty<'tcx>, + parent_cause: ObligationCause<'tcx>, +) -> Result<(), ConstParamTyImplementationError<'tcx>> { + let (adt, substs) = match self_type.kind() { + // `core` provides these impls. + ty::Uint(_) + | ty::Int(_) + | ty::Bool + | ty::Char + | ty::Str + | ty::Array(..) + | ty::Slice(_) + | ty::Ref(.., hir::Mutability::Not) => return Ok(()), + + &ty::Adt(adt, substs) => (adt, substs), + + _ => return Err(ConstParamTyImplementationError::NotAnAdtOrBuiltinAllowed), + }; + + all_fields_implement_trait( + tcx, + param_env, + self_type, + adt, + substs, + parent_cause, + hir::LangItem::ConstParamTy, + ) + .map_err(ConstParamTyImplementationError::InfrigingFields)?; + + Ok(()) +} + +/// Check that all fields of a given `adt` implement `lang_item` trait. +pub fn all_fields_implement_trait<'tcx>( + tcx: TyCtxt<'tcx>, + param_env: ty::ParamEnv<'tcx>, + self_type: Ty<'tcx>, + adt: AdtDef<'tcx>, + substs: &'tcx List<GenericArg<'tcx>>, + parent_cause: ObligationCause<'tcx>, + lang_item: LangItem, +) -> Result<(), Vec<(&'tcx ty::FieldDef, Ty<'tcx>, InfringingFieldsReason<'tcx>)>> { + let trait_def_id = tcx.require_lang_item(lang_item, Some(parent_cause.span)); let mut infringing = Vec::new(); for variant in adt.variants() { @@ -93,7 +172,7 @@ pub fn type_allowed_to_implement_copy<'tcx>( // between expected and found const-generic types. Don't report an // additional copy error here, since it's not typically useful. if !normalization_errors.is_empty() || ty.references_error() { - tcx.sess.delay_span_bug(field_span, format!("couldn't normalize struct field `{unnormalized_ty}` when checking Copy implementation")); + tcx.sess.delay_span_bug(field_span, format!("couldn't normalize struct field `{unnormalized_ty}` when checking {tr} implementation", tr = tcx.def_path_str(trait_def_id))); continue; } @@ -101,7 +180,7 @@ pub fn type_allowed_to_implement_copy<'tcx>( ObligationCause::dummy_with_span(field_ty_span), param_env, ty, - copy_def_id, + trait_def_id, ); let errors = ocx.select_all_or_error(); if !errors.is_empty() { @@ -124,15 +203,7 @@ pub fn type_allowed_to_implement_copy<'tcx>( } } - if !infringing.is_empty() { - return Err(CopyImplementationError::InfringingFields(infringing)); - } - - if adt.has_dtor(tcx) { - return Err(CopyImplementationError::HasDestructor); - } - - Ok(()) + if infringing.is_empty() { Ok(()) } else { Err(infringing) } } pub fn check_tys_might_be_eq<'tcx>( diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs index 4c9df5d9d0a..0e8c74a6765 100644 --- a/compiler/rustc_trait_selection/src/traits/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/mod.rs @@ -414,7 +414,7 @@ fn subst_and_check_impossible_predicates<'tcx>( predicates.push(ty::Binder::dummy(trait_ref).to_predicate(tcx)); } - predicates.retain(|predicate| !predicate.needs_subst()); + predicates.retain(|predicate| !predicate.has_param()); let result = impossible_predicates(tcx, predicates); debug!("subst_and_check_impossible_predicates(key={:?}) = {:?}", key, result); diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs index b8ad1925e4e..384b6ae93a1 100644 --- a/compiler/rustc_trait_selection/src/traits/object_safety.rs +++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs @@ -297,8 +297,8 @@ fn bounds_reference_self(tcx: TyCtxt<'_>, trait_def_id: DefId) -> SmallVec<[Span tcx.associated_items(trait_def_id) .in_definition_order() .filter(|item| item.kind == ty::AssocKind::Type) - .flat_map(|item| tcx.explicit_item_bounds(item.def_id)) - .filter_map(|pred_span| predicate_references_self(tcx, *pred_span)) + .flat_map(|item| tcx.explicit_item_bounds(item.def_id).subst_identity_iter_copied()) + .filter_map(|pred_span| predicate_references_self(tcx, pred_span)) .collect() } @@ -525,7 +525,7 @@ fn virtual_call_violation_for_method<'tcx>( // #78372 tcx.sess.delay_span_bug( tcx.def_span(method.def_id), - &format!("error: {}\n while computing layout for type {:?}", err, ty), + format!("error: {}\n while computing layout for type {:?}", err, ty), ); None } @@ -541,7 +541,7 @@ fn virtual_call_violation_for_method<'tcx>( abi => { tcx.sess.delay_span_bug( tcx.def_span(method.def_id), - &format!( + format!( "receiver when `Self = ()` should have a Scalar ABI; found {:?}", abi ), @@ -560,7 +560,7 @@ fn virtual_call_violation_for_method<'tcx>( abi => { tcx.sess.delay_span_bug( tcx.def_span(method.def_id), - &format!( + format!( "receiver when `Self = {}` should have a ScalarPair ABI; found {:?}", trait_object_ty, abi ), diff --git a/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs b/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs index e01a57ea4fe..0db80232891 100644 --- a/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs +++ b/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs @@ -60,7 +60,7 @@ impl<'a, 'tcx: 'a> InferCtxtExt<'a, 'tcx> for InferCtxt<'tcx> { // We may however encounter unconstrained lifetime variables in invalid // code. See #110161 for context. assert!(!ty.has_non_region_infer()); - if ty.needs_infer() { + if ty.has_infer() { self.tcx.sess.delay_span_bug( self.tcx.def_span(body_id), "skipped implied_outlives_bounds due to unconstrained lifetimes", diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs index ea45412e47f..4369b257f5f 100644 --- a/compiler/rustc_trait_selection/src/traits/project.rs +++ b/compiler/rustc_trait_selection/src/traits/project.rs @@ -1749,7 +1749,7 @@ fn assemble_candidates_from_impls<'cx, 'tcx>( // These traits have no associated types. selcx.tcx().sess.delay_span_bug( obligation.cause.span, - &format!("Cannot project an associated type from `{:?}`", impl_source), + format!("Cannot project an associated type from `{:?}`", impl_source), ); return Err(()); } diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs index 8f1b05c1190..1f8e756043d 100644 --- a/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs +++ b/compiler/rustc_trait_selection/src/traits/query/type_op/custom.rs @@ -79,7 +79,7 @@ pub fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>( if !errors.is_empty() { infcx.tcx.sess.diagnostic().delay_span_bug( DUMMY_SP, - &format!("errors selecting obligation during MIR typeck: {:?}", errors), + format!("errors selecting obligation during MIR typeck: {:?}", errors), ); } diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs index 081e4d7cfa4..9890e990eeb 100644 --- a/compiler/rustc_trait_selection/src/traits/select/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs @@ -67,7 +67,7 @@ impl IntercrateAmbiguityCause { /// Emits notes when the overlap is caused by complex intercrate ambiguities. /// See #23980 for details. pub fn add_intercrate_ambiguity_hint(&self, err: &mut Diagnostic) { - err.note(&self.intercrate_ambiguity_hint()); + err.note(self.intercrate_ambiguity_hint()); } pub fn intercrate_ambiguity_hint(&self) -> String { @@ -449,7 +449,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { debug!(?stack, ?candidates, "winnowed to {} candidates", candidates.len()); - let needs_infer = stack.obligation.predicate.has_non_region_infer(); + let has_non_region_infer = stack.obligation.predicate.has_non_region_infer(); // If there are STILL multiple candidates, we can further // reduce the list by dropping duplicates -- including @@ -461,7 +461,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { self.candidate_should_be_dropped_in_favor_of( &candidates[i], &candidates[j], - needs_infer, + has_non_region_infer, ) == DropVictim::Yes }); if should_drop_i { @@ -1000,7 +1000,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { ) -> Result<EvaluationResult, OverflowError> { if !self.is_intercrate() && obligation.is_global() - && obligation.param_env.caller_bounds().iter().all(|bound| bound.needs_subst()) + && obligation.param_env.caller_bounds().iter().all(|bound| bound.has_param()) { // If a param env has no global bounds, global obligations do not // depend on its particular value in order to work, so we can clear @@ -1330,7 +1330,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { } if self.can_use_global_caches(param_env) { - if !trait_pred.needs_infer() { + if !trait_pred.has_infer() { debug!(?trait_pred, ?result, "insert_evaluation_cache global"); // This may overwrite the cache with the same value // FIXME: Due to #50507 this overwrites the different values @@ -1516,7 +1516,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { // If there are any inference variables in the `ParamEnv`, then we // always use a cache local to this particular scope. Otherwise, we // switch to a global cache. - if param_env.needs_infer() { + if param_env.has_infer() { return false; } @@ -1587,7 +1587,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { return false; } match result { - Ok(Some(SelectionCandidate::ParamCandidate(trait_ref))) => !trait_ref.needs_infer(), + Ok(Some(SelectionCandidate::ParamCandidate(trait_ref))) => !trait_ref.has_infer(), _ => true, } } @@ -1613,8 +1613,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { if self.can_use_global_caches(param_env) { if let Err(Overflow(OverflowError::Canonical)) = candidate { // Don't cache overflow globally; we only produce this in certain modes. - } else if !pred.needs_infer() { - if !candidate.needs_infer() { + } else if !pred.has_infer() { + if !candidate.has_infer() { debug!(?pred, ?candidate, "insert_candidate_cache global"); // This may overwrite the cache with the same value. tcx.selection_cache.insert((param_env, pred), dep_node, candidate); @@ -1724,7 +1724,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { .map(|InferOk { obligations: _, value: () }| { // This method is called within a probe, so we can't have // inference variables and placeholders escape. - if !trait_bound.needs_infer() && !trait_bound.has_placeholders() { + if !trait_bound.has_infer() && !trait_bound.has_placeholders() { Some(trait_bound) } else { None @@ -1840,7 +1840,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> { &mut self, victim: &EvaluatedCandidate<'tcx>, other: &EvaluatedCandidate<'tcx>, - needs_infer: bool, + has_non_region_infer: bool, ) -> DropVictim { if victim.candidate == other.candidate { return DropVictim::Yes; @@ -1956,7 +1956,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> { | (ObjectCandidate(i), ObjectCandidate(j)) => { // Arbitrarily pick the lower numbered candidate for backwards // compatibility reasons. Don't let this affect inference. - DropVictim::drop_if(i < j && !needs_infer) + DropVictim::drop_if(i < j && !has_non_region_infer) } (ObjectCandidate(_), ProjectionCandidate(..)) | (ProjectionCandidate(..), ObjectCandidate(_)) => { @@ -2062,7 +2062,8 @@ impl<'tcx> SelectionContext<'_, 'tcx> { // existence of multiple marker trait impls tells us nothing // about which one should actually apply. DropVictim::drop_if( - !needs_infer && other.evaluation.must_apply_considering_regions(), + !has_non_region_infer + && other.evaluation.must_apply_considering_regions(), ) } None => DropVictim::No, @@ -2448,7 +2449,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> { // for a variable being generalized... let guar = self.infcx.tcx.sess.delay_span_bug( obligation.cause.span, - &format!( + format!( "Impl {:?} was matchable against {:?} but now is not", impl_def_id, obligation ), @@ -3006,16 +3007,16 @@ fn bind_generator_hidden_types_above<'tcx>( // Only remap erased regions if we use them. if considering_regions { - ty = tcx.fold_regions(ty, |mut r, current_depth| { - if let ty::ReErased = r.kind() { + ty = tcx.fold_regions(ty, |r, current_depth| match r.kind() { + ty::ReErased => { let br = ty::BoundRegion { var: ty::BoundVar::from_u32(counter), kind: ty::BrAnon(None), }; counter += 1; - r = tcx.mk_re_late_bound(current_depth, br); + tcx.mk_re_late_bound(current_depth, br) } - r + r => bug!("unexpected region: {r:?}"), }) } diff --git a/compiler/rustc_trait_selection/src/traits/specialize/mod.rs b/compiler/rustc_trait_selection/src/traits/specialize/mod.rs index 8546bbe52dc..233d35aed38 100644 --- a/compiler/rustc_trait_selection/src/traits/specialize/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/specialize/mod.rs @@ -373,7 +373,7 @@ fn report_conflicting_impls<'tcx>( } None => format!("conflicting implementation in crate `{}`", cname), }; - err.note(&msg); + err.note(msg); } } diff --git a/compiler/rustc_trait_selection/src/traits/vtable.rs b/compiler/rustc_trait_selection/src/traits/vtable.rs index a4e9928f8b2..c56e7c7cadd 100644 --- a/compiler/rustc_trait_selection/src/traits/vtable.rs +++ b/compiler/rustc_trait_selection/src/traits/vtable.rs @@ -353,8 +353,8 @@ pub(crate) fn vtable_trait_upcasting_coercion_new_vptr_slot<'tcx>( ), ) -> Option<usize> { let (source, target) = key; - assert!(matches!(&source.kind(), &ty::Dynamic(..)) && !source.needs_infer()); - assert!(matches!(&target.kind(), &ty::Dynamic(..)) && !target.needs_infer()); + assert!(matches!(&source.kind(), &ty::Dynamic(..)) && !source.has_infer()); + assert!(matches!(&target.kind(), &ty::Dynamic(..)) && !target.has_infer()); // this has been typecked-before, so diagnostics is not really needed. let unsize_trait_did = tcx.require_lang_item(LangItem::Unsize, None); |