X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=compiler%2Frustc_trait_selection%2Fsrc%2Ftraits%2Ferror_reporting%2Fmod.rs;h=ef3d300020a39086edaa7cb0f0a2ee80c20f83ba;hb=42afb70f2fc28c52656f49abf4566d17c09123ef;hp=f087afa20bacaabaafa023a54787cb4788820be0;hpb=fc105ef61ffad49d5e7008312d1e5e83333ab6e6;p=rust.git 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 f087afa20ba..ef3d300020a 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs @@ -22,6 +22,7 @@ MultiSpan, Style, }; use rustc_hir as hir; +use rustc_hir::def::Namespace; use rustc_hir::def_id::DefId; use rustc_hir::intravisit::Visitor; use rustc_hir::GenericParam; @@ -34,6 +35,7 @@ use rustc_middle::ty::abstract_const::NotConstEvaluatable; use rustc_middle::ty::error::ExpectedFound; use rustc_middle::ty::fold::{TypeFolder, TypeSuperFoldable}; +use rustc_middle::ty::print::{FmtPrinter, Print}; use rustc_middle::ty::{ self, SubtypePredicate, ToPolyTraitRef, ToPredicate, TraitRef, Ty, TyCtxt, TypeFoldable, TypeVisitable, @@ -109,7 +111,10 @@ fn report_overflow_error( suggest_increasing_limit: bool, ) -> ! where - T: fmt::Display + TypeFoldable<'tcx>; + T: fmt::Display + + TypeFoldable<'tcx> + + Print<'tcx, FmtPrinter<'tcx, 'tcx>, Output = FmtPrinter<'tcx, 'tcx>>, + >>::Error: std::fmt::Debug; fn suggest_new_overflow_limit(&self, err: &mut Diagnostic); @@ -342,16 +347,12 @@ fn type_implements_fn_trait( span: DUMMY_SP, kind: TypeVariableOriginKind::MiscVariable, }); - let substs = self.tcx.mk_substs_trait(ty.skip_binder(), &[var.into()]); + let trait_ref = self.tcx.mk_trait_ref(trait_def_id, [ty.skip_binder(), var]); let obligation = Obligation::new( self.tcx, ObligationCause::dummy(), param_env, - ty.rebind(ty::TraitPredicate { - trait_ref: ty::TraitRef::new(trait_def_id, substs), - constness, - polarity, - }), + ty.rebind(ty::TraitPredicate { trait_ref, constness, polarity }), ); let mut fulfill_cx = >::new_in_snapshot(self.tcx); fulfill_cx.register_predicate_obligation(self, obligation); @@ -468,15 +469,31 @@ fn report_overflow_error( suggest_increasing_limit: bool, ) -> ! where - T: fmt::Display + TypeFoldable<'tcx>, + T: fmt::Display + + TypeFoldable<'tcx> + + Print<'tcx, FmtPrinter<'tcx, 'tcx>, Output = FmtPrinter<'tcx, 'tcx>>, + >>::Error: std::fmt::Debug, { let predicate = self.resolve_vars_if_possible(obligation.predicate.clone()); + let mut pred_str = predicate.to_string(); + if pred_str.len() > 50 { + // We don't need to save the type to a file, we will be talking about this type already + // in a separate note when we explain the obligation, so it will be available that way. + pred_str = predicate + .print(FmtPrinter::new_with_limit( + self.tcx, + Namespace::TypeNS, + rustc_session::Limit(6), + )) + .unwrap() + .into_buffer(); + } let mut err = struct_span_err!( self.tcx.sess, obligation.cause.span, E0275, "overflow evaluating the requirement `{}`", - predicate + pred_str, ); if suggest_increasing_limit { @@ -532,9 +549,12 @@ fn report_selection_error( root_obligation: &PredicateObligation<'tcx>, error: &SelectionError<'tcx>, ) { - self.set_tainted_by_errors(); let tcx = self.tcx; let mut span = obligation.cause.span; + // FIXME: statically guarantee this by tainting after the diagnostic is emitted + self.set_tainted_by_errors( + tcx.sess.delay_span_bug(span, "`report_selection_error` did not emit an error"), + ); let mut err = match *error { SelectionError::Unimplemented => { @@ -977,12 +997,8 @@ fn report_selection_error( if trait_predicate.skip_binder().self_ty().is_never() && self.fallback_has_occurred { - let predicate = trait_predicate.map_bound(|mut trait_pred| { - trait_pred.trait_ref.substs = self.tcx.mk_substs_trait( - self.tcx.mk_unit(), - &trait_pred.trait_ref.substs[1..], - ); - trait_pred + let predicate = trait_predicate.map_bound(|trait_pred| { + trait_pred.with_self_type(self.tcx, self.tcx.mk_unit()) }); let unit_obligation = obligation.with(tcx, predicate); if self.predicate_may_hold(&unit_obligation) { @@ -1152,6 +1168,8 @@ fn report_selection_error( ) } + ty::PredicateKind::Ambiguous => span_bug!(span, "ambiguous"), + ty::PredicateKind::TypeWellFormedFromEnv(..) => span_bug!( span, "TypeWellFormedFromEnv predicate should only exist in the environment" @@ -1705,7 +1723,7 @@ fn type_category(tcx: TyCtxt<'_>, t: Ty<'_>) -> Option { ty::Bool => Some(0), ty::Char => Some(1), ty::Str => Some(2), - ty::Adt(def, _) if tcx.is_diagnostic_item(sym::String, def.did()) => Some(2), + ty::Adt(def, _) if Some(def.did()) == tcx.lang_items().string() => Some(2), ty::Int(..) | ty::Uint(..) | ty::Float(..) @@ -2004,13 +2022,8 @@ fn mk_trait_obligation_with_new_self_ty( param_env: ty::ParamEnv<'tcx>, trait_ref_and_ty: ty::Binder<'tcx, (ty::TraitPredicate<'tcx>, Ty<'tcx>)>, ) -> PredicateObligation<'tcx> { - let trait_pred = trait_ref_and_ty.map_bound_ref(|(tr, new_self_ty)| ty::TraitPredicate { - trait_ref: ty::TraitRef { - substs: self.tcx.mk_substs_trait(*new_self_ty, &tr.trait_ref.substs[1..]), - ..tr.trait_ref - }, - ..*tr - }); + let trait_pred = trait_ref_and_ty + .map_bound(|(tr, new_self_ty)| tr.with_self_type(self.tcx, new_self_ty)); Obligation::new(self.tcx, ObligationCause::dummy(), param_env, trait_pred) } @@ -2060,7 +2073,7 @@ fn maybe_report_ambiguity( // check upstream for type errors and don't add the obligations to // begin with in those cases. if self.tcx.lang_items().sized_trait() == Some(trait_ref.def_id()) { - if !self.is_tainted_by_errors() { + if let None = self.tainted_by_errors() { self.emit_inference_failure_err( body_id, span, @@ -2115,16 +2128,16 @@ fn maybe_report_ambiguity( if impls.len() > 1 && impls.len() < 5 && has_non_region_infer { self.annotate_source_of_ambiguity(&mut err, &impls, predicate); } else { - if self.is_tainted_by_errors() { - err.delay_as_bug(); + if self.tainted_by_errors().is_some() { + err.cancel(); return; } err.note(&format!("cannot satisfy `{}`", predicate)); } } _ => { - if self.is_tainted_by_errors() { - err.delay_as_bug(); + if self.tainted_by_errors().is_some() { + err.cancel(); return; } err.note(&format!("cannot satisfy `{}`", predicate)); @@ -2226,7 +2239,7 @@ fn visit_expr(&mut self, ex: &'v hir::Expr<'v>) { ] = path.segments && data.trait_ref.def_id == *trait_id && self.tcx.trait_of_item(*item_id) == Some(*trait_id) - && !self.is_tainted_by_errors() + && let None = self.tainted_by_errors() { let (verb, noun) = match self.tcx.associated_item(item_id).kind { ty::AssocKind::Const => ("refer to the", "constant"), @@ -2295,7 +2308,7 @@ fn visit_expr(&mut self, ex: &'v hir::Expr<'v>) { // with error messages. if arg.references_error() || self.tcx.sess.has_errors().is_some() - || self.is_tainted_by_errors() + || self.tainted_by_errors().is_some() { return; } @@ -2306,7 +2319,7 @@ fn visit_expr(&mut self, ex: &'v hir::Expr<'v>) { ty::PredicateKind::Subtype(data) => { if data.references_error() || self.tcx.sess.has_errors().is_some() - || self.is_tainted_by_errors() + || self.tainted_by_errors().is_some() { // no need to overload user in such cases return; @@ -2317,7 +2330,7 @@ fn visit_expr(&mut self, ex: &'v hir::Expr<'v>) { self.emit_inference_failure_err(body_id, span, a.into(), ErrorCode::E0282, true) } ty::PredicateKind::Projection(data) => { - if predicate.references_error() || self.is_tainted_by_errors() { + if predicate.references_error() || self.tainted_by_errors().is_some() { return; } let subst = data @@ -2351,7 +2364,7 @@ fn visit_expr(&mut self, ex: &'v hir::Expr<'v>) { } ty::PredicateKind::ConstEvaluatable(data) => { - if predicate.references_error() || self.is_tainted_by_errors() { + if predicate.references_error() || self.tainted_by_errors().is_some() { return; } let subst = data.walk().find(|g| g.is_non_region_infer()); @@ -2378,7 +2391,7 @@ fn visit_expr(&mut self, ex: &'v hir::Expr<'v>) { } } _ => { - if self.tcx.sess.has_errors().is_some() || self.is_tainted_by_errors() { + if self.tcx.sess.has_errors().is_some() || self.tainted_by_errors().is_some() { return; } let mut err = struct_span_err!( @@ -2422,7 +2435,7 @@ fn annotate_source_of_ambiguity( post.sort(); post.dedup(); - if self.is_tainted_by_errors() + if self.tainted_by_errors().is_some() && (crate_names.len() == 1 && spans.len() == 0 && ["`core`", "`alloc`", "`std`"].contains(&crate_names[0].as_str())