diff options
| author | Matthew Kelly <matthew.kelly2@gmail.com> | 2022-09-26 19:59:52 -0400 |
|---|---|---|
| committer | Matthew Kelly <matthew.kelly2@gmail.com> | 2022-09-26 19:59:52 -0400 |
| commit | 24aab524cbafec7ff8c7cd54ba4f6fb18216c623 (patch) | |
| tree | b0fd92c686ed3fe2b3a5a010c0dc32a6a54d3ea1 /compiler/rustc_trait_selection/src | |
| parent | eda2a401457ba645a32bdc5b9e7e90214e3e4e24 (diff) | |
| parent | 8b705839cd656d202e920efa8769cbe43a5ee269 (diff) | |
Merge remote-tracking branch 'origin/master' into mpk/add-long-error-message-for-E0311
Diffstat (limited to 'compiler/rustc_trait_selection/src')
26 files changed, 727 insertions, 354 deletions
diff --git a/compiler/rustc_trait_selection/src/autoderef.rs b/compiler/rustc_trait_selection/src/autoderef.rs index 8b7e8984a8a..36ab8f3bd88 100644 --- a/compiler/rustc_trait_selection/src/autoderef.rs +++ b/compiler/rustc_trait_selection/src/autoderef.rs @@ -1,6 +1,6 @@ +use crate::errors::AutoDerefReachedRecursionLimit; use crate::traits::query::evaluate_obligation::InferCtxtExt; use crate::traits::{self, TraitEngine}; -use rustc_errors::struct_span_err; use rustc_hir as hir; use rustc_infer::infer::InferCtxt; use rustc_middle::ty::{self, TraitRef, Ty, TyCtxt}; @@ -222,19 +222,10 @@ pub fn report_autoderef_recursion_limit_error<'tcx>(tcx: TyCtxt<'tcx>, span: Spa Limit(0) => Limit(2), limit => limit * 2, }; - struct_span_err!( - tcx.sess, + tcx.sess.emit_err(AutoDerefReachedRecursionLimit { span, - E0055, - "reached the recursion limit while auto-dereferencing `{:?}`", - ty - ) - .span_label(span, "deref recursion limit reached") - .help(&format!( - "consider increasing the recursion limit by adding a \ - `#![recursion_limit = \"{}\"]` attribute to your crate (`{}`)", + ty, suggested_limit, - tcx.crate_name(LOCAL_CRATE), - )) - .emit(); + crate_name: tcx.crate_name(LOCAL_CRATE), + }); } diff --git a/compiler/rustc_trait_selection/src/errors.rs b/compiler/rustc_trait_selection/src/errors.rs new file mode 100644 index 00000000000..61793468594 --- /dev/null +++ b/compiler/rustc_trait_selection/src/errors.rs @@ -0,0 +1,102 @@ +use rustc_errors::{fluent, ErrorGuaranteed, Handler, IntoDiagnostic}; +use rustc_macros::Diagnostic; +use rustc_middle::ty::{self, PolyTraitRef, Ty}; +use rustc_session::Limit; +use rustc_span::{Span, Symbol}; + +#[derive(Diagnostic)] +#[diag(trait_selection::dump_vtable_entries)] +pub struct DumpVTableEntries<'a> { + #[primary_span] + pub span: Span, + pub trait_ref: PolyTraitRef<'a>, + pub entries: String, +} + +#[derive(Diagnostic)] +#[diag(trait_selection::unable_to_construct_constant_value)] +pub struct UnableToConstructConstantValue<'a> { + #[primary_span] + pub span: Span, + pub unevaluated: ty::UnevaluatedConst<'a>, +} + +#[derive(Diagnostic)] +#[help] +#[diag(trait_selection::auto_deref_reached_recursion_limit, code = "E0055")] +pub struct AutoDerefReachedRecursionLimit<'a> { + #[primary_span] + #[label] + pub span: Span, + pub ty: Ty<'a>, + pub suggested_limit: Limit, + pub crate_name: Symbol, +} + +#[derive(Diagnostic)] +#[diag(trait_selection::empty_on_clause_in_rustc_on_unimplemented, code = "E0232")] +pub struct EmptyOnClauseInOnUnimplemented { + #[primary_span] + #[label] + pub span: Span, +} + +#[derive(Diagnostic)] +#[diag(trait_selection::invalid_on_clause_in_rustc_on_unimplemented, code = "E0232")] +pub struct InvalidOnClauseInOnUnimplemented { + #[primary_span] + #[label] + pub span: Span, +} + +#[derive(Diagnostic)] +#[diag(trait_selection::no_value_in_rustc_on_unimplemented, code = "E0232")] +#[note] +pub struct NoValueInOnUnimplemented { + #[primary_span] + #[label] + pub span: Span, +} + +pub struct NegativePositiveConflict<'a> { + pub impl_span: Span, + pub trait_desc: &'a str, + pub self_desc: &'a Option<String>, + pub negative_impl_span: Result<Span, Symbol>, + pub positive_impl_span: Result<Span, Symbol>, +} + +impl IntoDiagnostic<'_> for NegativePositiveConflict<'_> { + fn into_diagnostic( + self, + handler: &Handler, + ) -> rustc_errors::DiagnosticBuilder<'_, ErrorGuaranteed> { + let mut diag = handler.struct_err(fluent::trait_selection::negative_positive_conflict); + diag.set_arg("trait_desc", self.trait_desc); + diag.set_arg( + "self_desc", + self.self_desc.clone().map_or_else(|| String::from("none"), |ty| ty), + ); + diag.set_span(self.impl_span); + diag.code(rustc_errors::error_code!(E0751)); + match self.negative_impl_span { + Ok(span) => { + diag.span_label(span, fluent::trait_selection::negative_implementation_here); + } + Err(cname) => { + diag.note(fluent::trait_selection::negative_implementation_in_crate); + diag.set_arg("negative_impl_cname", cname.to_string()); + } + } + match self.positive_impl_span { + Ok(span) => { + diag.span_label(span, fluent::trait_selection::positive_implementation_here); + } + Err(cname) => { + diag.note(fluent::trait_selection::positive_implementation_in_crate); + diag.set_arg("positive_impl_cname", cname.to_string()); + } + } + diag + } +} diff --git a/compiler/rustc_trait_selection/src/infer.rs b/compiler/rustc_trait_selection/src/infer.rs index 9d30374f8b8..ba403ab2da2 100644 --- a/compiler/rustc_trait_selection/src/infer.rs +++ b/compiler/rustc_trait_selection/src/infer.rs @@ -24,6 +24,13 @@ pub trait InferCtxtExt<'tcx> { span: Span, ) -> bool; + fn type_is_sized_modulo_regions( + &self, + param_env: ty::ParamEnv<'tcx>, + ty: Ty<'tcx>, + span: Span, + ) -> bool; + fn partially_normalize_associated_types_in<T>( &self, cause: ObligationCause<'tcx>, @@ -74,6 +81,16 @@ impl<'cx, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'cx, 'tcx> { traits::type_known_to_meet_bound_modulo_regions(self, param_env, ty, copy_def_id, span) } + fn type_is_sized_modulo_regions( + &self, + param_env: ty::ParamEnv<'tcx>, + ty: Ty<'tcx>, + span: Span, + ) -> bool { + let lang_item = self.tcx.require_lang_item(LangItem::Sized, None); + traits::type_known_to_meet_bound_modulo_regions(self, param_env, ty, lang_item, span) + } + /// Normalizes associated types in `value`, potentially returning /// new obligations that must further be processed. fn partially_normalize_associated_types_in<T>( diff --git a/compiler/rustc_trait_selection/src/lib.rs b/compiler/rustc_trait_selection/src/lib.rs index 77cc2c164c3..5d52aa07523 100644 --- a/compiler/rustc_trait_selection/src/lib.rs +++ b/compiler/rustc_trait_selection/src/lib.rs @@ -16,9 +16,7 @@ #![feature(control_flow_enum)] #![feature(drain_filter)] #![feature(hash_drain_filter)] -#![cfg_attr(bootstrap, feature(label_break_value))] #![feature(let_chains)] -#![feature(let_else)] #![feature(if_let_guard)] #![feature(never_type)] #![feature(type_alias_impl_trait)] @@ -37,5 +35,6 @@ extern crate rustc_middle; extern crate smallvec; pub mod autoderef; +pub mod errors; pub mod infer; pub mod traits; diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs index 4bab9935501..6ed4f1b8c49 100644 --- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs +++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs @@ -3,13 +3,14 @@ use super::*; +use crate::errors::UnableToConstructConstantValue; use crate::infer::region_constraints::{Constraint, RegionConstraintData}; use crate::infer::InferCtxt; use crate::traits::project::ProjectAndUnifyResult; use rustc_middle::mir::interpret::ErrorHandled; use rustc_middle::ty::fold::{TypeFolder, TypeSuperFoldable}; use rustc_middle::ty::visit::TypeVisitable; -use rustc_middle::ty::{Region, RegionVid, Term}; +use rustc_middle::ty::{Region, RegionVid}; use rustc_data_structures::fx::{FxHashMap, FxHashSet}; @@ -611,7 +612,7 @@ impl<'tcx> AutoTraitFinder<'tcx> { } fn is_self_referential_projection(&self, p: ty::PolyProjectionPredicate<'_>) -> bool { - if let Term::Ty(ty) = p.term().skip_binder() { + if let Some(ty) = p.term().skip_binder().ty() { matches!(ty.kind(), ty::Projection(proj) if proj == &p.skip_binder().projection_ty) } else { false @@ -830,8 +831,11 @@ impl<'tcx> AutoTraitFinder<'tcx> { Ok(None) => { let tcx = self.tcx; let def_id = unevaluated.def.did; - let reported = tcx.sess.struct_span_err(tcx.def_span(def_id), &format!("unable to construct a constant value for the unevaluated constant {:?}", unevaluated)).emit(); - + let reported = + tcx.sess.emit_err(UnableToConstructConstantValue { + span: tcx.def_span(def_id), + unevaluated: unevaluated, + }); Err(ErrorHandled::Reported(reported)) } Err(err) => Err(err), diff --git a/compiler/rustc_trait_selection/src/traits/codegen.rs b/compiler/rustc_trait_selection/src/traits/codegen.rs index c0700748c79..0155798c8b6 100644 --- a/compiler/rustc_trait_selection/src/traits/codegen.rs +++ b/compiler/rustc_trait_selection/src/traits/codegen.rs @@ -4,10 +4,12 @@ // general routines. use crate::infer::{DefiningAnchor, TyCtxtInferExt}; +use crate::traits::error_reporting::InferCtxtExt; use crate::traits::{ ImplSource, Obligation, ObligationCause, SelectionContext, TraitEngine, TraitEngineExt, Unimplemented, }; +use rustc_infer::traits::FulfillmentErrorCode; use rustc_middle::traits::CodegenObligationError; use rustc_middle::ty::{self, TyCtxt}; @@ -18,8 +20,7 @@ use rustc_middle::ty::{self, TyCtxt}; /// obligations *could be* resolved if we wanted to. /// /// This also expects that `trait_ref` is fully normalized. -#[instrument(level = "debug", skip(tcx))] -pub fn codegen_fulfill_obligation<'tcx>( +pub fn codegen_select_candidate<'tcx>( tcx: TyCtxt<'tcx>, (param_env, trait_ref): (ty::ParamEnv<'tcx>, ty::PolyTraitRef<'tcx>), ) -> Result<&'tcx ImplSource<'tcx, ()>, CodegenObligationError> { @@ -63,6 +64,14 @@ pub fn codegen_fulfill_obligation<'tcx>( // optimization to stop iterating early. let errors = fulfill_cx.select_all_or_error(&infcx); if !errors.is_empty() { + // `rustc_monomorphize::collector` assumes there are no type errors. + // Cycle errors are the only post-monomorphization errors possible; emit them now so + // `rustc_ty_utils::resolve_associated_item` doesn't return `None` post-monomorphization. + for err in errors { + if let FulfillmentErrorCode::CodeCycle(cycle) = err.code { + infcx.report_overflow_error_cycle(&cycle); + } + } return Err(CodegenObligationError::FulfillmentError); } @@ -74,7 +83,6 @@ pub fn codegen_fulfill_obligation<'tcx>( // (ouz-a) This is required for `type-alias-impl-trait/assoc-projection-ice.rs` to pass let _ = infcx.inner.borrow_mut().opaque_type_storage.take_opaque_types(); - debug!("Cache miss: {trait_ref:?} => {impl_source:?}"); Ok(&*tcx.arena.alloc(impl_source)) }) } diff --git a/compiler/rustc_trait_selection/src/traits/coherence.rs b/compiler/rustc_trait_selection/src/traits/coherence.rs index 292787d4dbb..94de8abce19 100644 --- a/compiler/rustc_trait_selection/src/traits/coherence.rs +++ b/compiler/rustc_trait_selection/src/traits/coherence.rs @@ -22,7 +22,6 @@ use rustc_infer::infer::{InferCtxt, TyCtxtInferExt}; use rustc_infer::traits::util; use rustc_middle::traits::specialization_graph::OverlapMode; use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams}; -use rustc_middle::ty::subst::Subst; use rustc_middle::ty::visit::TypeVisitable; use rustc_middle::ty::{self, ImplSubject, Ty, TyCtxt, TypeVisitor}; use rustc_span::symbol::sym; diff --git a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs index 254bc4ab663..dc585fca34f 100644 --- a/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs +++ b/compiler/rustc_trait_selection/src/traits/const_evaluatable.rs @@ -138,7 +138,7 @@ impl<'tcx> ConstUnifyCtxt<'tcx> { #[instrument(skip(tcx), level = "debug")] pub fn try_unify_abstract_consts<'tcx>( tcx: TyCtxt<'tcx>, - (a, b): (ty::Unevaluated<'tcx, ()>, ty::Unevaluated<'tcx, ()>), + (a, b): (ty::UnevaluatedConst<'tcx>, ty::UnevaluatedConst<'tcx>), param_env: ty::ParamEnv<'tcx>, ) -> bool { (|| { @@ -161,7 +161,7 @@ pub fn try_unify_abstract_consts<'tcx>( #[instrument(skip(infcx), level = "debug")] pub fn is_const_evaluatable<'cx, 'tcx>( infcx: &InferCtxt<'cx, 'tcx>, - uv: ty::Unevaluated<'tcx, ()>, + uv: ty::UnevaluatedConst<'tcx>, param_env: ty::ParamEnv<'tcx>, span: Span, ) -> Result<(), NotConstEvaluatable> { @@ -183,7 +183,7 @@ pub fn is_const_evaluatable<'cx, 'tcx>( FailureKind::Concrete => {} } } - let concrete = infcx.const_eval_resolve(param_env, uv.expand(), Some(span)); + let concrete = infcx.const_eval_resolve(param_env, uv, Some(span)); match concrete { Err(ErrorHandled::TooGeneric) => { Err(NotConstEvaluatable::Error(infcx.tcx.sess.delay_span_bug( @@ -210,7 +210,7 @@ pub fn is_const_evaluatable<'cx, 'tcx>( // and hopefully soon change this to an error. // // See #74595 for more details about this. - let concrete = infcx.const_eval_resolve(param_env, uv.expand(), Some(span)); + let concrete = infcx.const_eval_resolve(param_env, uv, Some(span)); match concrete { // If we're evaluating a foreign constant, under a nightly compiler without generic 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 e4af7022239..b0cabc6275f 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs @@ -349,7 +349,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { message, label, note, - enclosing_scope, + parent_label, append_const_msg, } = self.on_unimplemented_note(trait_ref, &obligation); let have_alt_message = message.is_some() || label.is_some(); @@ -450,12 +450,27 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { { "consider using `()`, or a `Result`".to_owned() } else { - format!( - "{}the trait `{}` is not implemented for `{}`", - pre_message, - trait_predicate.print_modifiers_and_trait_path(), - trait_ref.skip_binder().self_ty(), - ) + let ty_desc = match trait_ref.skip_binder().self_ty().kind() { + ty::FnDef(_, _) => Some("fn item"), + ty::Closure(_, _) => Some("closure"), + _ => None, + }; + + match ty_desc { + Some(desc) => format!( + "{}the trait `{}` is not implemented for {} `{}`", + pre_message, + trait_predicate.print_modifiers_and_trait_path(), + desc, + trait_ref.skip_binder().self_ty(), + ), + None => format!( + "{}the trait `{}` is not implemented for `{}`", + pre_message, + trait_predicate.print_modifiers_and_trait_path(), + trait_ref.skip_binder().self_ty(), + ), + } }; if self.suggest_add_reference_to_arg( @@ -515,7 +530,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { // If it has a custom `#[rustc_on_unimplemented]` note, let's display it err.note(s.as_str()); } - if let Some(ref s) = enclosing_scope { + if let Some(ref s) = parent_label { let body = tcx .hir() .opt_local_def_id(obligation.cause.body_id) @@ -524,11 +539,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { hir_id: obligation.cause.body_id, }) }); - - let enclosing_scope_span = - tcx.hir().span_with_body(tcx.hir().local_def_id_to_hir_id(body)); - - err.span_label(enclosing_scope_span, s); + err.span_label(tcx.def_span(body), s); } self.suggest_floating_point_literal(&obligation, &mut err, &trait_ref); @@ -1529,6 +1540,9 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> { } diag.emit(); } + FulfillmentErrorCode::CodeCycle(ref cycle) => { + self.report_overflow_error_cycle(cycle); + } } } @@ -1805,13 +1819,21 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> { return false; } if candidates.len() == 1 { + let ty_desc = match candidates[0].self_ty().kind() { + ty::FnPtr(_) => Some("fn pointer"), + _ => None, + }; + let the_desc = match ty_desc { + Some(desc) => format!(" implemented for {} `", desc), + None => " implemented for `".to_string(), + }; err.highlighted_help(vec![ ( format!("the trait `{}` ", candidates[0].print_only_trait_path()), Style::NoStyle, ), ("is".to_string(), Style::Highlight), - (" implemented for `".to_string(), Style::NoStyle), + (the_desc, Style::NoStyle), (candidates[0].self_ty().to_string(), Style::Highlight), ("`".to_string(), Style::NoStyle), ]); @@ -1878,7 +1900,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> { // types, too. self.tcx .visibility(def.did()) - .is_accessible_from(body_id.owner.to_def_id(), self.tcx) + .is_accessible_from(body_id.owner.def_id, self.tcx) } else { true } @@ -2014,7 +2036,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> { let predicate = self.resolve_vars_if_possible(obligation.predicate); let span = obligation.cause.span; - debug!(?predicate, obligation.cause.code = tracing::field::debug(&obligation.cause.code())); + debug!(?predicate, obligation.cause.code = ?obligation.cause.code()); // Ambiguity errors are often caused as fallout from earlier errors. // We ignore them if this `infcx` is tainted in some cases below. @@ -2191,12 +2213,12 @@ impl<'a, 'tcx> InferCtxtPrivExt<'a, 'tcx> for InferCtxt<'a, 'tcx> { && let [ .., trait_path_segment @ hir::PathSegment { - res: Some(rustc_hir::def::Res::Def(rustc_hir::def::DefKind::Trait, trait_id)), + res: rustc_hir::def::Res::Def(rustc_hir::def::DefKind::Trait, trait_id), .. }, hir::PathSegment { ident: assoc_item_name, - res: Some(rustc_hir::def::Res::Def(_, item_id)), + res: rustc_hir::def::Res::Def(_, item_id), .. } ] = path.segments diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs index 6b03555bc69..07e470dc2ae 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs @@ -4,7 +4,7 @@ use super::{ use crate::infer::InferCtxt; use rustc_hir as hir; use rustc_hir::def_id::DefId; -use rustc_middle::ty::subst::{Subst, SubstsRef}; +use rustc_middle::ty::SubstsRef; use rustc_middle::ty::{self, GenericParamDefKind}; use rustc_span::symbol::sym; use std::iter; @@ -256,7 +256,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { } } } - if let ty::Dynamic(traits, _) = self_ty.kind() { + if let ty::Dynamic(traits, _, _) = self_ty.kind() { for t in traits.iter() { if let ty::ExistentialPredicate::Trait(trait_ref) = t.skip_binder() { flags.push((sym::_Self, Some(self.tcx.def_path_str(trait_ref.def_id)))) 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 02adae5bde1..fff26547be0 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs @@ -25,8 +25,7 @@ use rustc_middle::hir::map; use rustc_middle::ty::{ self, suggest_arbitrary_trait_bound, suggest_constraining_type_param, AdtKind, DefIdTree, GeneratorDiagnosticData, GeneratorInteriorTypeCause, Infer, InferTy, IsSuggestable, - ProjectionPredicate, ToPredicate, Ty, TyCtxt, TypeFoldable, TypeFolder, TypeSuperFoldable, - TypeVisitable, + ToPredicate, Ty, TyCtxt, TypeFoldable, TypeFolder, TypeSuperFoldable, TypeVisitable, }; use rustc_middle::ty::{TypeAndMut, TypeckResults}; use rustc_session::Limit; @@ -174,7 +173,7 @@ pub trait InferCtxtExt<'tcx> { &self, err: &mut Diagnostic, trait_pred: ty::PolyTraitPredicate<'tcx>, - proj_pred: Option<ty::PolyProjectionPredicate<'tcx>>, + associated_item: Option<(&'static str, Ty<'tcx>)>, body_id: hir::HirId, ); @@ -467,7 +466,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { &self, mut err: &mut Diagnostic, trait_pred: ty::PolyTraitPredicate<'tcx>, - proj_pred: Option<ty::PolyProjectionPredicate<'tcx>>, + associated_ty: Option<(&'static str, Ty<'tcx>)>, body_id: hir::HirId, ) { let trait_pred = self.resolve_numeric_literals_with_default(trait_pred); @@ -604,21 +603,18 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { trait_pred.print_modifiers_and_trait_path().to_string() ); - if let Some(proj_pred) = proj_pred { - let ProjectionPredicate { projection_ty, term } = proj_pred.skip_binder(); - let item = self.tcx.associated_item(projection_ty.item_def_id); - + if let Some((name, term)) = associated_ty { // FIXME: this case overlaps with code in TyCtxt::note_and_explain_type_err. // That should be extracted into a helper function. if constraint.ends_with('>') { constraint = format!( - "{}, {}={}>", + "{}, {} = {}>", &constraint[..constraint.len() - 1], - item.name, + name, term ); } else { - constraint.push_str(&format!("<{}={}>", item.name, term)); + constraint.push_str(&format!("<{} = {}>", name, term)); } } @@ -648,7 +644,13 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { .. }) if !param_ty => { // Missing generic type parameter bound. - if suggest_arbitrary_trait_bound(self.tcx, generics, &mut err, trait_pred) { + if suggest_arbitrary_trait_bound( + self.tcx, + generics, + &mut err, + trait_pred, + associated_ty, + ) { return; } } @@ -657,7 +659,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { _ => {} } - hir_id = self.tcx.hir().local_def_id_to_hir_id(self.tcx.hir().get_parent_item(hir_id)); + hir_id = self.tcx.hir().get_parent_item(hir_id).into(); } } @@ -774,7 +776,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { // Get the local name of this closure. This can be inaccurate because // of the possibility of reassignment, but this should be good enough. match &kind { - hir::PatKind::Binding(hir::BindingAnnotation::Unannotated, _, ident, None) => { + hir::PatKind::Binding(hir::BindingAnnotation::NONE, _, ident, None) => { Some(ident.name) } _ => { @@ -1065,7 +1067,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { self_ty: Ty<'tcx>, object_ty: Ty<'tcx>, ) { - let ty::Dynamic(predicates, _) = object_ty.kind() else { return; }; + let ty::Dynamic(predicates, _, ty::Dyn) = object_ty.kind() else { return; }; let self_ref_ty = self.tcx.mk_imm_ref(self.tcx.lifetimes.re_erased, self_ty); for predicate in predicates.iter() { @@ -1158,8 +1160,8 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { // 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. - err.span_suggestion_verbose( - expr.span.shrink_to_hi().with_hi(span.hi()), + err.span_suggestion( + span, "remove the `.await`", "", Applicability::MachineApplicable, @@ -1363,7 +1365,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { let trait_pred = self.resolve_vars_if_possible(trait_pred); let ty = trait_pred.skip_binder().self_ty(); let is_object_safe = match ty.kind() { - ty::Dynamic(predicates, _) => { + ty::Dynamic(predicates, _, ty::Dyn) => { // If the `dyn Trait` is not object safe, do not suggest `Box<dyn Trait>`. predicates .principal_def_id() @@ -1423,7 +1425,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { let mut spans_and_needs_box = vec![]; match liberated_sig.output().kind() { - ty::Dynamic(predicates, _) => { + ty::Dynamic(predicates, _, _) => { let cause = ObligationCause::misc(ret_ty.span, fn_hir_id); let param_env = ty::ParamEnv::empty(); @@ -2254,7 +2256,8 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { | ObligationCauseCode::QuestionMark | ObligationCauseCode::CheckAssociatedTypeBounds { .. } | ObligationCauseCode::LetElse - | ObligationCauseCode::BinOp { .. } => {} + | ObligationCauseCode::BinOp { .. } + | ObligationCauseCode::AscribeUserTypeProvePredicate(..) => {} ObligationCauseCode::SliceOrArrayElem => { err.note("slice and array elements must have `Sized` type"); } @@ -2709,14 +2712,15 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { let parent_id = hir.get_parent_item(arg_hir_id); let typeck_results: &TypeckResults<'tcx> = match &in_progress_typeck_results { Some(t) if t.hir_owner == parent_id => t, - _ => self.tcx.typeck(parent_id), + _ => self.tcx.typeck(parent_id.def_id), }; - let ty = typeck_results.expr_ty_adjusted(expr); - let span = expr.peel_blocks().span; + let expr = expr.peel_blocks(); + let ty = typeck_results.expr_ty_adjusted_opt(expr).unwrap_or(tcx.ty_error()); + let span = expr.span; if Some(span) != err.span.primary_span() { err.span_label( span, - &if ty.references_error() { + if ty.references_error() { String::new() } else { format!("this tail expression is of type `{:?}`", ty) diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs index d840677f1ca..6f3a9412dde 100644 --- a/compiler/rustc_trait_selection/src/traits/fulfill.rs +++ b/compiler/rustc_trait_selection/src/traits/fulfill.rs @@ -25,10 +25,9 @@ use super::Unimplemented; use super::{FulfillmentError, FulfillmentErrorCode}; use super::{ObligationCause, PredicateObligation}; -use crate::traits::error_reporting::InferCtxtExt as _; use crate::traits::project::PolyProjectionObligation; use crate::traits::project::ProjectionCacheKeyExt as _; -use crate::traits::query::evaluate_obligation::InferCtxtExt as _; +use crate::traits::query::evaluate_obligation::InferCtxtExt; impl<'tcx> ForestObligation for PendingPredicateObligation<'tcx> { /// Note that we include both the `ParamEnv` and the `Predicate`, @@ -135,7 +134,7 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentContext<'tcx> { /// `SomeTrait` or a where-clause that lets us unify `$0` with /// something concrete. If this fails, we'll unify `$0` with /// `projection_ty` again. - #[tracing::instrument(level = "debug", skip(self, infcx, param_env, cause))] + #[instrument(level = "debug", skip(self, infcx, param_env, cause))] fn normalize_projection_type( &mut self, infcx: &InferCtxt<'_, 'tcx>, @@ -224,6 +223,7 @@ fn mk_pending(os: Vec<PredicateObligation<'_>>) -> Vec<PendingPredicateObligatio impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> { type Obligation = PendingPredicateObligation<'tcx>; type Error = FulfillmentErrorCode<'tcx>; + type OUT = Outcome<Self::Obligation, Self::Error>; /// Identifies whether a predicate obligation needs processing. /// @@ -427,16 +427,14 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> { obligation.param_env, Binder::dummy(subtype), ) { - None => { + Err((a, b)) => { // None means that both are unresolved. - pending_obligation.stalled_on = vec![ - TyOrConstInferVar::maybe_from_ty(subtype.a).unwrap(), - TyOrConstInferVar::maybe_from_ty(subtype.b).unwrap(), - ]; + pending_obligation.stalled_on = + vec![TyOrConstInferVar::Ty(a), TyOrConstInferVar::Ty(b)]; ProcessResult::Unchanged } - Some(Ok(ok)) => ProcessResult::Changed(mk_pending(ok.obligations)), - Some(Err(err)) => { + Ok(Ok(ok)) => ProcessResult::Changed(mk_pending(ok.obligations)), + Ok(Err(err)) => { let expected_found = ExpectedFound::new(subtype.a_is_expected, subtype.a, subtype.b); ProcessResult::Error(FulfillmentErrorCode::CodeSubtypeError( @@ -453,16 +451,14 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> { obligation.param_env, Binder::dummy(coerce), ) { - None => { + Err((a, b)) => { // None means that both are unresolved. - pending_obligation.stalled_on = vec![ - TyOrConstInferVar::maybe_from_ty(coerce.a).unwrap(), - TyOrConstInferVar::maybe_from_ty(coerce.b).unwrap(), - ]; + pending_obligation.stalled_on = + vec![TyOrConstInferVar::Ty(a), TyOrConstInferVar::Ty(b)]; ProcessResult::Unchanged } - Some(Ok(ok)) => ProcessResult::Changed(mk_pending(ok.obligations)), - Some(Err(err)) => { + Ok(Ok(ok)) => ProcessResult::Changed(mk_pending(ok.obligations)), + Ok(Err(err)) => { let expected_found = ExpectedFound::new(false, coerce.a, coerce.b); ProcessResult::Error(FulfillmentErrorCode::CodeSubtypeError( expected_found, @@ -509,11 +505,7 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> { if let (ty::ConstKind::Unevaluated(a), ty::ConstKind::Unevaluated(b)) = (c1.kind(), c2.kind()) { - if infcx.try_unify_abstract_consts( - a.shrink(), - b.shrink(), - obligation.param_env, - ) { + if infcx.try_unify_abstract_consts(a, b, obligation.param_env) { return ProcessResult::Changed(vec![]); } } @@ -602,14 +594,16 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> { &mut self, cycle: I, _marker: PhantomData<&'c PendingPredicateObligation<'tcx>>, - ) where + ) -> Result<(), FulfillmentErrorCode<'tcx>> + where I: Clone + Iterator<Item = &'c PendingPredicateObligation<'tcx>>, { if self.selcx.coinductive_match(cycle.clone().map(|s| s.obligation.predicate)) { debug!("process_child_obligations: coinductive match"); + Ok(()) } else { let cycle: Vec<_> = cycle.map(|c| c.obligation.clone()).collect(); - self.selcx.infcx().report_overflow_error_cycle(&cycle); + Err(FulfillmentErrorCode::CodeCycle(cycle)) } } } diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs index e11ea7751aa..8da68c225d8 100644 --- a/compiler/rustc_trait_selection/src/traits/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/mod.rs @@ -23,6 +23,7 @@ mod structural_match; mod util; pub mod wf; +use crate::errors::DumpVTableEntries; use crate::infer::outlives::env::OutlivesEnvironment; use crate::infer::{InferCtxt, TyCtxtInferExt}; use crate::traits::error_reporting::InferCtxtExt as _; @@ -33,12 +34,11 @@ use rustc_hir::def_id::DefId; use rustc_hir::lang_items::LangItem; use rustc_infer::traits::TraitEngineExt as _; use rustc_middle::ty::fold::TypeFoldable; -use rustc_middle::ty::subst::{InternalSubsts, SubstsRef}; use rustc_middle::ty::visit::TypeVisitable; use rustc_middle::ty::{ - self, DefIdTree, GenericParamDefKind, Subst, ToPredicate, Ty, TyCtxt, TypeSuperVisitable, - VtblEntry, + self, DefIdTree, GenericParamDefKind, ToPredicate, Ty, TyCtxt, TypeSuperVisitable, VtblEntry, }; +use rustc_middle::ty::{InternalSubsts, SubstsRef}; use rustc_span::{sym, Span}; use smallvec::SmallVec; @@ -129,7 +129,7 @@ pub fn predicates_for_generics<'tcx>( move |(idx, (predicate, span))| Obligation { cause: cause(idx, span), recursion_depth: 0, - param_env: param_env, + param_env, predicate, }, ) @@ -763,8 +763,11 @@ fn dump_vtable_entries<'tcx>( trait_ref: ty::PolyTraitRef<'tcx>, entries: &[VtblEntry<'tcx>], ) { - let msg = format!("vtable entries for `{}`: {:#?}", trait_ref, entries); - tcx.sess.struct_span_err(sp, &msg).emit(); + tcx.sess.emit_err(DumpVTableEntries { + span: sp, + trait_ref, + entries: format!("{:#?}", entries), + }); } fn own_existential_vtable_entries<'tcx>( @@ -967,7 +970,7 @@ pub fn provide(providers: &mut ty::query::Providers) { *providers = ty::query::Providers { specialization_graph_of: specialize::specialization_graph_provider, specializes: specialize::specializes, - codegen_fulfill_obligation: codegen::codegen_fulfill_obligation, + codegen_select_candidate: codegen::codegen_select_candidate, own_existential_vtable_entries, vtable_entries, vtable_trait_upcasting_coercion_new_vptr_slot, diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs index 612f5130908..2773b61e9ba 100644 --- a/compiler/rustc_trait_selection/src/traits/object_safety.rs +++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs @@ -13,14 +13,15 @@ use super::elaborate_predicates; use crate::infer::TyCtxtInferExt; use crate::traits::query::evaluate_obligation::InferCtxtExt; use crate::traits::{self, Obligation, ObligationCause}; +use hir::def::DefKind; use rustc_errors::{FatalError, MultiSpan}; use rustc_hir as hir; use rustc_hir::def_id::DefId; use rustc_middle::ty::abstract_const::{walk_abstract_const, AbstractConst}; -use rustc_middle::ty::subst::{GenericArg, InternalSubsts, Subst}; use rustc_middle::ty::{ self, EarlyBinder, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, TypeVisitor, }; +use rustc_middle::ty::{GenericArg, InternalSubsts}; use rustc_middle::ty::{Predicate, ToPredicate}; use rustc_session::lint::builtin::WHERE_CLAUSES_OBJECT_SAFETY; use rustc_span::symbol::Symbol; @@ -431,6 +432,9 @@ fn virtual_call_violation_for_method<'tcx>( if contains_illegal_self_type_reference(tcx, trait_def_id, sig.output()) { return Some(MethodViolationCode::ReferencesSelfOutput); } + if contains_illegal_impl_trait_in_trait(tcx, sig.output()) { + return Some(MethodViolationCode::ReferencesImplTraitInTrait); + } // We can't monomorphize things like `fn foo<A>(...)`. let own_counts = tcx.generics_of(method.def_id).own_counts(); @@ -596,7 +600,7 @@ fn object_ty_for_trait<'tcx>( let existential_predicates = tcx .mk_poly_existential_predicates(iter::once(trait_predicate).chain(projection_predicates)); - let object_ty = tcx.mk_dynamic(existential_predicates, lifetime); + let object_ty = tcx.mk_dynamic(existential_predicates, lifetime, ty::Dyn); debug!("object_ty_for_trait: object_ty=`{}`", object_ty); @@ -793,6 +797,12 @@ fn contains_illegal_self_type_reference<'tcx, T: TypeVisitable<'tcx>>( ControlFlow::CONTINUE } } + ty::Projection(ref data) + if self.tcx.def_kind(data.item_def_id) == DefKind::ImplTraitPlaceholder => + { + // We'll deny these later in their own pass + ControlFlow::CONTINUE + } ty::Projection(ref data) => { // This is a projected type `<Foo as SomeTrait>::X`. @@ -828,7 +838,10 @@ fn contains_illegal_self_type_reference<'tcx, T: TypeVisitable<'tcx>>( } } - fn visit_unevaluated(&mut self, uv: ty::Unevaluated<'tcx>) -> ControlFlow<Self::BreakTy> { + fn visit_ty_unevaluated( + &mut self, + uv: ty::UnevaluatedConst<'tcx>, + ) -> ControlFlow<Self::BreakTy> { // Constants can only influence object safety if they reference `Self`. // This is only possible for unevaluated constants, so we walk these here. // @@ -842,7 +855,7 @@ fn contains_illegal_self_type_reference<'tcx, T: TypeVisitable<'tcx>>( // This shouldn't really matter though as we can't really use any // constants which are not considered const evaluatable. use rustc_middle::ty::abstract_const::Node; - if let Ok(Some(ct)) = AbstractConst::new(self.tcx, uv.shrink()) { + if let Ok(Some(ct)) = AbstractConst::new(self.tcx, uv) { walk_abstract_const(self.tcx, ct, |node| match node.root(self.tcx) { Node::Leaf(leaf) => self.visit_const(leaf), Node::Cast(_, _, ty) => self.visit_ty(ty), @@ -861,6 +874,22 @@ fn contains_illegal_self_type_reference<'tcx, T: TypeVisitable<'tcx>>( .is_break() } +pub fn contains_illegal_impl_trait_in_trait<'tcx>( + tcx: TyCtxt<'tcx>, + ty: ty::Binder<'tcx, Ty<'tcx>>, +) -> bool { + // FIXME(RPITIT): Perhaps we should use a visitor here? + ty.skip_binder().walk().any(|arg| { + if let ty::GenericArgKind::Type(ty) = arg.unpack() + && let ty::Projection(proj) = ty.kind() + { + tcx.def_kind(proj.item_def_id) == DefKind::ImplTraitPlaceholder + } else { + false + } + }) +} + pub fn provide(providers: &mut ty::query::Providers) { *providers = ty::query::Providers { object_safety_violations, ..*providers }; } diff --git a/compiler/rustc_trait_selection/src/traits/on_unimplemented.rs b/compiler/rustc_trait_selection/src/traits/on_unimplemented.rs index 9227bbf011d..4a4f34b7680 100644 --- a/compiler/rustc_trait_selection/src/traits/on_unimplemented.rs +++ b/compiler/rustc_trait_selection/src/traits/on_unimplemented.rs @@ -8,6 +8,10 @@ use rustc_parse_format::{ParseMode, Parser, Piece, Position}; use rustc_span::symbol::{kw, sym, Symbol}; use rustc_span::{Span, DUMMY_SP}; +use crate::errors::{ + EmptyOnClauseInOnUnimplemented, InvalidOnClauseInOnUnimplemented, NoValueInOnUnimplemented, +}; + #[derive(Clone, Debug)] pub struct OnUnimplementedFormatString(Symbol); @@ -18,7 +22,7 @@ pub struct OnUnimplementedDirective { pub message: Option<OnUnimplementedFormatString>, pub label: Option<OnUnimplementedFormatString>, pub note: Option<OnUnimplementedFormatString>, - pub enclosing_scope: Option<OnUnimplementedFormatString>, + pub parent_label: Option<OnUnimplementedFormatString>, pub append_const_msg: Option<Option<Symbol>>, } @@ -27,7 +31,7 @@ pub struct OnUnimplementedNote { pub message: Option<String>, pub label: Option<String>, pub note: Option<String>, - pub enclosing_scope: Option<String>, + pub parent_label: Option<String>, /// Append a message for `~const Trait` errors. `None` means not requested and /// should fallback to a generic message, `Some(None)` suggests using the default /// appended message, `Some(Some(s))` suggests use the `s` message instead of the @@ -35,21 +39,6 @@ pub struct OnUnimplementedNote { pub append_const_msg: Option<Option<Symbol>>, } -fn parse_error( - tcx: TyCtxt<'_>, - span: Span, - message: &str, - label: &str, - note: Option<&str>, -) -> ErrorGuaranteed { - let mut diag = struct_span_err!(tcx.sess, span, E0232, "{}", message); - diag.span_label(span, label); - if let Some(note) = note { - diag.note(note); - } - diag.emit() -} - impl<'tcx> OnUnimplementedDirective { fn parse( tcx: TyCtxt<'tcx>, @@ -70,25 +59,9 @@ impl<'tcx> OnUnimplementedDirective { } else { let cond = item_iter .next() - .ok_or_else(|| { - parse_error( - tcx, - span, - "empty `on`-clause in `#[rustc_on_unimplemented]`", - "empty on-clause here", - None, - ) - })? + .ok_or_else(|| tcx.sess.emit_err(EmptyOnClauseInOnUnimplemented { span }))? .meta_item() - .ok_or_else(|| { - parse_error( - tcx, - span, - "invalid `on`-clause in `#[rustc_on_unimplemented]`", - "invalid on-clause here", - None, - ) - })?; + .ok_or_else(|| tcx.sess.emit_err(InvalidOnClauseInOnUnimplemented { span }))?; attr::eval_condition(cond, &tcx.sess.parse_sess, Some(tcx.features()), &mut |cfg| { if let Some(value) = cfg.value && let Err(guar) = parse_value(value) { errored = Some(guar); @@ -101,7 +74,7 @@ impl<'tcx> OnUnimplementedDirective { let mut message = None; let mut label = None; let mut note = None; - let mut enclosing_scope = None; + let mut parent_label = None; let mut subcommands = vec![]; let mut append_const_msg = None; @@ -121,9 +94,9 @@ impl<'tcx> OnUnimplementedDirective { note = parse_value(note_)?; continue; } - } else if item.has_name(sym::enclosing_scope) && enclosing_scope.is_none() { - if let Some(enclosing_scope_) = item.value_str() { - enclosing_scope = parse_value(enclosing_scope_)?; + } else if item.has_name(sym::parent_label) && parent_label.is_none() { + if let Some(parent_label_) = item.value_str() { + parent_label = parse_value(parent_label_)?; continue; } } else if item.has_name(sym::on) @@ -150,13 +123,7 @@ impl<'tcx> OnUnimplementedDirective { } // nothing found - parse_error( - tcx, - item.span(), - "this attribute must have a valid value", - "expected value here", - Some(r#"eg `#[rustc_on_unimplemented(message="foo")]`"#), - ); + tcx.sess.emit_err(NoValueInOnUnimplemented { span: item.span() }); } if let Some(reported) = errored { @@ -168,7 +135,7 @@ impl<'tcx> OnUnimplementedDirective { message, label, note, - enclosing_scope, + parent_label, append_const_msg, }) } @@ -193,7 +160,7 @@ impl<'tcx> OnUnimplementedDirective { attr.span, )?), note: None, - enclosing_scope: None, + parent_label: None, append_const_msg: None, })) } else { @@ -214,7 +181,7 @@ impl<'tcx> OnUnimplementedDirective { let mut message = None; let mut label = None; let mut note = None; - let mut enclosing_scope = None; + let mut parent_label = None; let mut append_const_msg = None; info!("evaluate({:?}, trait_ref={:?}, options={:?})", self, trait_ref, options); @@ -250,8 +217,8 @@ impl<'tcx> OnUnimplementedDirective { note = Some(note_.clone()); } - if let Some(ref enclosing_scope_) = command.enclosing_scope { - enclosing_scope = Some(enclosing_scope_.clone()); + if let Some(ref parent_label_) = command.parent_label { + parent_label = Some(parent_label_.clone()); } append_const_msg = command.append_const_msg; @@ -261,7 +228,7 @@ impl<'tcx> OnUnimplementedDirective { label: label.map(|l| l.format(tcx, trait_ref, &options_map)), message: message.map(|m| m.format(tcx, trait_ref, &options_map)), note: note.map(|n| n.format(tcx, trait_ref, &options_map)), - enclosing_scope: enclosing_scope.map(|e_s| e_s.format(tcx, trait_ref, &options_map)), + parent_label: parent_label.map(|e_s| e_s.format(tcx, trait_ref, &options_map)), append_const_msg, } } diff --git a/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs b/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs index a4b54018228..3008dfcadde 100644 --- a/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs +++ b/compiler/rustc_trait_selection/src/traits/outlives_bounds.rs @@ -46,7 +46,7 @@ impl<'a, 'cx, 'tcx: 'a> InferCtxtExt<'a, 'tcx> for InferCtxt<'cx, 'tcx> { /// Note that this may cause outlives obligations to be injected /// into the inference context with this body-id. /// - `ty`, the type that we are supposed to assume is WF. - #[instrument(level = "debug", skip(self, param_env, body_id))] + #[instrument(level = "debug", skip(self, param_env, body_id), ret)] fn implied_outlives_bounds( &self, param_env: ty::ParamEnv<'tcx>, @@ -71,6 +71,7 @@ impl<'a, 'cx, 'tcx: 'a> InferCtxtExt<'a, 'tcx> for InferCtxt<'cx, 'tcx> { let TypeOpOutput { output, constraints, .. } = result; if let Some(constraints) = constraints { + debug!(?constraints); // Instantiation may have produced new inference variables and constraints on those // variables. Process these constraints. let mut fulfill_cx = <dyn TraitEngine<'tcx>>::new(self.tcx); diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs index 444ca6471e2..07b65a9748d 100644 --- a/compiler/rustc_trait_selection/src/traits/project.rs +++ b/compiler/rustc_trait_selection/src/traits/project.rs @@ -30,8 +30,8 @@ use rustc_hir::lang_items::LangItem; use rustc_infer::infer::resolve::OpportunisticRegionResolver; use rustc_middle::traits::select::OverflowError; use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable}; -use rustc_middle::ty::subst::Subst; use rustc_middle::ty::visit::{MaxUniverse, TypeVisitable}; +use rustc_middle::ty::DefIdTree; use rustc_middle::ty::{self, Term, ToPredicate, Ty, TyCtxt}; use rustc_span::symbol::sym; @@ -70,6 +70,8 @@ enum ProjectionCandidate<'tcx> { /// From an "impl" (or a "pseudo-impl" returned by select) Select(Selection<'tcx>), + + ImplTraitInTrait(ImplSourceUserDefinedData<'tcx, PredicateObligation<'tcx>>), } enum ProjectionCandidateSet<'tcx> { @@ -231,7 +233,7 @@ pub(super) fn poly_project_and_unify_type<'cx, 'tcx>( /// If successful, this may result in additional obligations. /// /// See [poly_project_and_unify_type] for an explanation of the return value. -#[tracing::instrument(level = "debug", skip(selcx))] +#[instrument(level = "debug", skip(selcx))] fn project_and_unify_type<'cx, 'tcx>( selcx: &mut SelectionContext<'cx, 'tcx>, obligation: &ProjectionObligation<'tcx>, @@ -497,7 +499,7 @@ impl<'a, 'b, 'tcx> TypeFolder<'tcx> for AssocTypeNormalizer<'a, 'b, 'tcx> { // This is really important. While we *can* handle this, this has // severe performance implications for large opaque types with // late-bound regions. See `issue-88862` benchmark. - ty::Opaque(def_id, substs) if !substs.has_escaping_bound_vars() => { + ty::Opaque(def_id, substs) => { // Only normalize `impl Trait` outside of type inference, usually in codegen. match self.param_env.reveal() { Reveal::UserFacing => ty.super_fold_with(self), @@ -552,7 +554,7 @@ impl<'a, 'b, 'tcx> TypeFolder<'tcx> for AssocTypeNormalizer<'a, 'b, 'tcx> { ) .ok() .flatten() - .unwrap_or_else(|| ty::Term::Ty(ty.super_fold_with(self))) + .unwrap_or_else(|| ty.super_fold_with(self).into()) }; // For cases like #95134 we would like to catch overflows early // otherwise they slip away away and cause ICE. @@ -635,13 +637,18 @@ impl<'a, 'b, 'tcx> TypeFolder<'tcx> for AssocTypeNormalizer<'a, 'b, 'tcx> { #[instrument(skip(self), level = "debug")] fn fold_const(&mut self, constant: ty::Const<'tcx>) -> ty::Const<'tcx> { - if self.selcx.tcx().lazy_normalization() || !self.eager_inference_replacement { + let tcx = self.selcx.tcx(); + if tcx.lazy_normalization() { constant } else { let constant = constant.super_fold_with(self); - debug!(?constant); - debug!("self.param_env: {:?}", self.param_env); - constant.eval(self.selcx.tcx(), self.param_env) + debug!(?constant, ?self.param_env); + with_replaced_escaping_bound_vars( + self.selcx.infcx(), + &mut self.universes, + constant, + |constant| constant.eval(tcx, self.param_env), + ) } } @@ -671,6 +678,41 @@ pub struct BoundVarReplacer<'me, 'tcx> { universe_indices: &'me mut Vec<Option<ty::UniverseIndex>>, } +/// Executes `f` on `value` after replacing all escaping bound variables with placeholders +/// and then replaces these placeholders with the original bound variables in the result. +/// +/// In most places, bound variables should be replaced right when entering a binder, making +/// this function unnecessary. However, normalization currently does not do that, so we have +/// to do this lazily. +/// +/// You should not add any additional uses of this function, at least not without first +/// discussing it with t-types. +/// +/// FIXME(@lcnr): We may even consider experimenting with eagerly replacing bound vars during +/// normalization as well, at which point this function will be unnecessary and can be removed. +pub fn with_replaced_escaping_bound_vars<'a, 'tcx, T: TypeFoldable<'tcx>, R: TypeFoldable<'tcx>>( + infcx: &'a InferCtxt<'a, 'tcx>, + universe_indices: &'a mut Vec<Option<ty::UniverseIndex>>, + value: T, + f: impl FnOnce(T) -> R, +) -> R { + if value.has_escaping_bound_vars() { + let (value, mapped_regions, mapped_types, mapped_consts) = + BoundVarReplacer::replace_bound_vars(infcx, universe_indices, value); + let result = f(value); + PlaceholderReplacer::replace_placeholders( + infcx, + mapped_regions, + mapped_types, + mapped_consts, + universe_indices, + result, + ) + } else { + f(value) + } +} + impl<'me, 'tcx> BoundVarReplacer<'me, 'tcx> { /// Returns `Some` if we *were* able to replace bound vars. If there are any bound vars that /// use a binding level above `universe_indices.len()`, we fail. @@ -1206,7 +1248,7 @@ impl<'tcx> Progress<'tcx> { /// /// IMPORTANT: /// - `obligation` must be fully normalized -#[tracing::instrument(level = "info", skip(selcx))] +#[instrument(level = "info", skip(selcx))] fn project<'cx, 'tcx>( selcx: &mut SelectionContext<'cx, 'tcx>, obligation: &ProjectionTyObligation<'tcx>, @@ -1225,6 +1267,8 @@ fn project<'cx, 'tcx>( let mut candidates = ProjectionCandidateSet::None; + assemble_candidate_for_impl_trait_in_trait(selcx, obligation, &mut candidates); + // Make sure that the following procedures are kept in order. ParamEnv // needs to be first because it has highest priority, and Select checks // the return value of push_candidate which assumes it's ran at last. @@ -1263,6 +1307,48 @@ fn project<'cx, 'tcx>( } } +/// If the predicate's item is an `ImplTraitPlaceholder`, we do a select on the +/// corresponding trait ref. If this yields an `impl`, then we're able to project +/// to a concrete type, since we have an `impl`'s method to provide the RPITIT. +fn assemble_candidate_for_impl_trait_in_trait<'cx, 'tcx>( + selcx: &mut SelectionContext<'cx, 'tcx>, + obligation: &ProjectionTyObligation<'tcx>, + candidate_set: &mut ProjectionCandidateSet<'tcx>, +) { + let tcx = selcx.tcx(); + if tcx.def_kind(obligation.predicate.item_def_id) == DefKind::ImplTraitPlaceholder { + let trait_fn_def_id = tcx.impl_trait_in_trait_parent(obligation.predicate.item_def_id); + let trait_def_id = tcx.parent(trait_fn_def_id); + let trait_substs = + obligation.predicate.substs.truncate_to(tcx, tcx.generics_of(trait_def_id)); + // FIXME(named-returns): Binders + let trait_predicate = + ty::Binder::dummy(ty::TraitRef { def_id: trait_def_id, substs: trait_substs }) + .to_poly_trait_predicate(); + + let _ = + selcx.infcx().commit_if_ok(|_| match selcx.select(&obligation.with(trait_predicate)) { + Ok(Some(super::ImplSource::UserDefined(data))) => { + candidate_set.push_candidate(ProjectionCandidate::ImplTraitInTrait(data)); + Ok(()) + } + Ok(None) => { + candidate_set.mark_ambiguous(); + return Err(()); + } + Ok(Some(_)) => { + // Don't know enough about the impl to provide a useful signature + return Err(()); + } + Err(e) => { + debug!(error = ?e, "selection error"); + candidate_set.mark_error(e); + return Err(()); + } + }); + } +} + /// The first thing we have to do is scan through the parameter /// environment to see whether there are any projection predicates /// there that can answer this question. @@ -1368,7 +1454,7 @@ fn assemble_candidates_from_object_ty<'cx, 'tcx>( ); } -#[tracing::instrument( +#[instrument( level = "debug", skip(selcx, candidate_set, ctor, env_predicates, potentially_unnormalized_candidates) )] @@ -1419,12 +1505,17 @@ fn assemble_candidates_from_predicates<'cx, 'tcx>( } } -#[tracing::instrument(level = "debug", skip(selcx, obligation, candidate_set))] +#[instrument(level = "debug", skip(selcx, obligation, candidate_set))] fn assemble_candidates_from_impls<'cx, 'tcx>( selcx: &mut SelectionContext<'cx, 'tcx>, obligation: &ProjectionTyObligation<'tcx>, candidate_set: &mut ProjectionCandidateSet<'tcx>, ) { + // Can't assemble candidate from impl for RPITIT + if selcx.tcx().def_kind(obligation.predicate.item_def_id) == DefKind::ImplTraitPlaceholder { + return; + } + // If we are resolving `<T as TraitRef<...>>::Item == Type`, // start out by selecting the predicate `T as TraitRef<...>`: let poly_trait_ref = ty::Binder::dummy(obligation.predicate.trait_ref(selcx.tcx())); @@ -1659,7 +1750,8 @@ fn assemble_candidates_from_impls<'cx, 'tcx>( super::ImplSource::AutoImpl(..) | super::ImplSource::Builtin(..) | super::ImplSource::TraitUpcasting(_) - | super::ImplSource::ConstDestruct(_) => { + | super::ImplSource::ConstDestruct(_) + | super::ImplSource::Tuple => { // These traits have no associated types. selcx.tcx().sess.delay_span_bug( obligation.cause.span, @@ -1700,6 +1792,9 @@ fn confirm_candidate<'cx, 'tcx>( ProjectionCandidate::Select(impl_source) => { confirm_select_candidate(selcx, obligation, impl_source) } + ProjectionCandidate::ImplTraitInTrait(data) => { + confirm_impl_trait_in_trait_candidate(selcx, obligation, data) + } }; // When checking for cycle during evaluation, we compare predicates with @@ -1734,7 +1829,8 @@ fn confirm_select_candidate<'cx, 'tcx>( | super::ImplSource::Builtin(..) | super::ImplSource::TraitUpcasting(_) | super::ImplSource::TraitAlias(..) - | super::ImplSource::ConstDestruct(_) => { + | super::ImplSource::ConstDestruct(_) + | super::ImplSource::Tuple => { // we don't create Select candidates with this kind of resolution span_bug!( obligation.cause.span, @@ -2045,7 +2141,7 @@ fn confirm_impl_candidate<'cx, 'tcx>( let identity_substs = crate::traits::InternalSubsts::identity_for_item(tcx, assoc_ty.item.def_id); let did = ty::WithOptConstParam::unknown(assoc_ty.item.def_id); - let kind = ty::ConstKind::Unevaluated(ty::Unevaluated::new(did, identity_substs)); + let kind = ty::ConstKind::Unevaluated(ty::UnevaluatedConst::new(did, identity_substs)); ty.map_bound(|ty| tcx.mk_const(ty::ConstS { ty, kind }).into()) } else { ty.map_bound(|ty| ty.into()) @@ -2062,10 +2158,74 @@ fn confirm_impl_candidate<'cx, 'tcx>( } } +fn confirm_impl_trait_in_trait_candidate<'tcx>( + selcx: &mut SelectionContext<'_, 'tcx>, + obligation: &ProjectionTyObligation<'tcx>, + data: ImplSourceUserDefinedData<'tcx, PredicateObligation<'tcx>>, +) -> Progress<'tcx> { + let tcx = selcx.tcx(); + let mut obligations = data.nested; + + let trait_fn_def_id = tcx.impl_trait_in_trait_parent(obligation.predicate.item_def_id); + let Ok(leaf_def) = assoc_def(selcx, data.impl_def_id, trait_fn_def_id) else { + return Progress { term: tcx.ty_error().into(), obligations }; + }; + if !leaf_def.item.defaultness(tcx).has_value() { + return Progress { term: tcx.ty_error().into(), obligations }; + } + + let impl_fn_def_id = leaf_def.item.def_id; + let impl_fn_substs = obligation.predicate.substs.rebase_onto(tcx, trait_fn_def_id, data.substs); + + let cause = ObligationCause::new( + obligation.cause.span, + obligation.cause.body_id, + super::ItemObligation(impl_fn_def_id), + ); + let predicates = normalize_with_depth_to( + selcx, + obligation.param_env, + cause.clone(), + obligation.recursion_depth + 1, + tcx.predicates_of(impl_fn_def_id).instantiate(tcx, impl_fn_substs), + &mut obligations, + ); + obligations.extend(std::iter::zip(predicates.predicates, predicates.spans).map( + |(pred, span)| { + Obligation::with_depth( + ObligationCause::new( + obligation.cause.span, + obligation.cause.body_id, + if span.is_dummy() { + super::ItemObligation(impl_fn_def_id) + } else { + super::BindingObligation(impl_fn_def_id, span) + }, + ), + obligation.recursion_depth + 1, + obligation.param_env, + pred, + ) + }, + )); + + let ty = super::normalize_to( + selcx, + obligation.param_env, + cause.clone(), + tcx.bound_trait_impl_trait_tys(impl_fn_def_id) + .map_bound(|tys| { + tys.map_or_else(|_| tcx.ty_error(), |tys| tys[&obligation.predicate.item_def_id]) + }) + .subst(tcx, impl_fn_substs), + &mut obligations, + ); + + Progress { term: ty.into(), obligations } +} + // Get obligations corresponding to the predicates from the where-clause of the // associated type itself. -// Note: `feature(generic_associated_types)` is required to write such -// predicates, even for non-generic associated types. fn assoc_ty_own_obligations<'cx, 'tcx>( selcx: &mut SelectionContext<'cx, 'tcx>, obligation: &ProjectionTyObligation<'tcx>, diff --git a/compiler/rustc_trait_selection/src/traits/query/normalize.rs b/compiler/rustc_trait_selection/src/traits/query/normalize.rs index 61c556b726d..31e7fb67f0e 100644 --- a/compiler/rustc_trait_selection/src/traits/query/normalize.rs +++ b/compiler/rustc_trait_selection/src/traits/query/normalize.rs @@ -6,14 +6,13 @@ use crate::infer::at::At; use crate::infer::canonical::OriginalQueryValues; use crate::infer::{InferCtxt, InferOk}; use crate::traits::error_reporting::InferCtxtExt; -use crate::traits::project::needs_normalization; +use crate::traits::project::{needs_normalization, BoundVarReplacer, PlaceholderReplacer}; use crate::traits::{Obligation, ObligationCause, PredicateObligation, Reveal}; use rustc_data_structures::sso::SsoHashMap; use rustc_data_structures::stack::ensure_sufficient_stack; use rustc_infer::traits::Normalized; use rustc_middle::mir; use rustc_middle::ty::fold::{FallibleTypeFolder, TypeFoldable, TypeSuperFoldable}; -use rustc_middle::ty::subst::Subst; use rustc_middle::ty::visit::{TypeSuperVisitable, TypeVisitable}; use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitor}; @@ -48,10 +47,11 @@ impl<'cx, 'tcx> AtExt<'tcx> for At<'cx, 'tcx> { T: TypeFoldable<'tcx>, { debug!( - "normalize::<{}>(value={:?}, param_env={:?})", + "normalize::<{}>(value={:?}, param_env={:?}, cause={:?})", std::any::type_name::<T>(), value, self.param_env, + self.cause, ); if !needs_normalization(&value, self.param_env.reveal()) { return Ok(Normalized { value, obligations: vec![] }); @@ -198,7 +198,7 @@ impl<'cx, 'tcx> FallibleTypeFolder<'tcx> for QueryNormalizer<'cx, 'tcx> { // This is really important. While we *can* handle this, this has // severe performance implications for large opaque types with // late-bound regions. See `issue-88862` benchmark. - ty::Opaque(def_id, substs) if !substs.has_escaping_bound_vars() => { + ty::Opaque(def_id, substs) => { // Only normalize `impl Trait` outside of type inference, usually in codegen. match self.param_env.reveal() { Reveal::UserFacing => ty.try_super_fold_with(self), @@ -283,11 +283,7 @@ impl<'cx, 'tcx> FallibleTypeFolder<'tcx> for QueryNormalizer<'cx, 'tcx> { let tcx = self.infcx.tcx; let infcx = self.infcx; let (data, mapped_regions, mapped_types, mapped_consts) = - crate::traits::project::BoundVarReplacer::replace_bound_vars( - infcx, - &mut self.universes, - data, - ); + BoundVarReplacer::replace_bound_vars(infcx, &mut self.universes, data); let data = data.try_fold_with(self)?; let mut orig_values = OriginalQueryValues::default(); @@ -313,8 +309,7 @@ impl<'cx, 'tcx> FallibleTypeFolder<'tcx> for QueryNormalizer<'cx, 'tcx> { debug!("QueryNormalizer: result = {:#?}", result); debug!("QueryNormalizer: obligations = {:#?}", obligations); self.obligations.extend(obligations); - - let res = crate::traits::project::PlaceholderReplacer::replace_placeholders( + let res = PlaceholderReplacer::replace_placeholders( infcx, mapped_regions, mapped_types, @@ -343,30 +338,20 @@ impl<'cx, 'tcx> FallibleTypeFolder<'tcx> for QueryNormalizer<'cx, 'tcx> { constant: ty::Const<'tcx>, ) -> Result<ty::Const<'tcx>, Self::Error> { let constant = constant.try_super_fold_with(self)?; - Ok(constant.eval(self.infcx.tcx, self.param_env)) + debug!(?constant, ?self.param_env); + Ok(crate::traits::project::with_replaced_escaping_bound_vars( + self.infcx, + &mut self.universes, + constant, + |constant| constant.eval(self.infcx.tcx, self.param_env), + )) } fn try_fold_mir_const( &mut self, constant: mir::ConstantKind<'tcx>, ) -> Result<mir::ConstantKind<'tcx>, Self::Error> { - Ok(match constant { - mir::ConstantKind::Ty(c) => { - let const_folded = c.try_super_fold_with(self)?; - match const_folded.kind() { - ty::ConstKind::Value(valtree) => { - let tcx = self.infcx.tcx; - let ty = const_folded.ty(); - let const_val = tcx.valtree_to_const_val((ty, valtree)); - debug!(?ty, ?valtree, ?const_val); - - mir::ConstantKind::Val(const_val, ty) - } - _ => mir::ConstantKind::Ty(const_folded), - } - } - mir::ConstantKind::Val(_, _) => constant.try_super_fold_with(self)?, - }) + constant.try_super_fold_with(self) } #[inline] 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 f6e196e3141..18988861add 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 @@ -23,7 +23,7 @@ impl<F, G> CustomTypeOp<F, G> { } } -impl<'tcx, F, R, G> super::TypeOp<'tcx> for CustomTypeOp<F, G> +impl<'tcx, F, R: fmt::Debug, G> super::TypeOp<'tcx> for CustomTypeOp<F, G> where F: for<'a, 'cx> FnOnce(&'a InferCtxt<'cx, 'tcx>) -> Fallible<InferOk<'tcx, R>>, G: Fn() -> String, @@ -89,8 +89,8 @@ pub fn scrape_region_constraints<'tcx, Op: super::TypeOp<'tcx, Output = R>, R>( infcx.tcx, region_obligations .iter() - .map(|r_o| (r_o.sup_type, r_o.sub_region)) - .map(|(ty, r)| (infcx.resolve_vars_if_possible(ty), r)), + .map(|r_o| (r_o.sup_type, r_o.sub_region, r_o.origin.to_constraint_category())) + .map(|(ty, r, cc)| (infcx.resolve_vars_if_possible(ty), r, cc)), ®ion_constraint_data, ); diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs index 578e1d00cf9..8a79165702c 100644 --- a/compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/query/type_op/mod.rs @@ -26,7 +26,7 @@ pub use rustc_middle::traits::query::type_op::*; /// extract out the resulting region constraints (or an error if it /// cannot be completed). pub trait TypeOp<'tcx>: Sized + fmt::Debug { - type Output; + type Output: fmt::Debug; type ErrorInfo; /// Processes the operation and all resulting obligations, diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs index d67bd6292b4..451427a6980 100644 --- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs +++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs @@ -28,7 +28,7 @@ use super::SelectionCandidate::{self, *}; use super::{EvaluatedCandidate, SelectionCandidateSet, SelectionContext, TraitObligationStack}; impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { - #[instrument(level = "debug", skip(self))] + #[instrument(level = "debug", skip(self), ret)] pub(super) fn candidate_from_obligation<'o>( &mut self, stack: &TraitObligationStack<'o, 'tcx>, @@ -48,7 +48,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { if let Some(c) = self.check_candidate_cache(stack.obligation.param_env, cache_fresh_trait_pred) { - debug!(candidate = ?c, "CACHE HIT"); + debug!("CACHE HIT"); return c; } @@ -61,7 +61,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let (candidate, dep_node) = self.in_task(|this| this.candidate_from_obligation_no_cache(stack)); - debug!(?candidate, "CACHE MISS"); + debug!("CACHE MISS"); self.insert_candidate_cache( stack.obligation.param_env, cache_fresh_trait_pred, @@ -309,6 +309,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { // User-defined transmutability impls are permitted. self.assemble_candidates_from_impls(obligation, &mut candidates); self.assemble_candidates_for_transmutability(obligation, &mut candidates); + } else if lang_items.tuple_trait() == Some(def_id) { + self.assemble_candidate_for_tuple(obligation, &mut candidates); } else { if lang_items.clone_trait() == Some(def_id) { // Same builtin conditions as `Copy`, i.e., every type which has builtin support @@ -337,7 +339,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { Ok(candidates) } - #[tracing::instrument(level = "debug", skip(self, candidates))] + #[instrument(level = "debug", skip(self, candidates))] fn assemble_candidates_from_projected_tys( &mut self, obligation: &TraitObligation<'tcx>, @@ -360,14 +362,16 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { .infcx .probe(|_| self.match_projection_obligation_against_definition_bounds(obligation)); - candidates.vec.extend(result.into_iter().map(ProjectionCandidate)); + candidates + .vec + .extend(result.into_iter().map(|(idx, constness)| ProjectionCandidate(idx, constness))); } /// Given an obligation like `<SomeTrait for T>`, searches the obligations that the caller /// supplied to find out whether it is listed among them. /// /// Never affects the inference environment. - #[tracing::instrument(level = "debug", skip(self, stack, candidates))] + #[instrument(level = "debug", skip(self, stack, candidates))] fn assemble_candidates_from_caller_bounds<'o>( &mut self, stack: &TraitObligationStack<'o, 'tcx>, @@ -880,7 +884,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { }; } - #[tracing::instrument(level = "debug", skip(self, obligation, candidates))] + #[instrument(level = "debug", skip(self, obligation, candidates))] fn assemble_candidates_for_transmutability( &mut self, obligation: &TraitObligation<'tcx>, @@ -898,7 +902,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { candidates.vec.push(TransmutabilityCandidate); } - #[tracing::instrument(level = "debug", skip(self, obligation, candidates))] + #[instrument(level = "debug", skip(self, obligation, candidates))] fn assemble_candidates_for_trait_alias( &mut self, obligation: &TraitObligation<'tcx>, @@ -917,7 +921,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { /// Assembles the trait which are built-in to the language itself: /// `Copy`, `Clone` and `Sized`. - #[tracing::instrument(level = "debug", skip(self, candidates))] + #[instrument(level = "debug", skip(self, candidates))] fn assemble_builtin_bound_candidates( &mut self, conditions: BuiltinImplConditions<'tcx>, @@ -1009,4 +1013,46 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { } } } + + fn assemble_candidate_for_tuple( + &mut self, + obligation: &TraitObligation<'tcx>, + candidates: &mut SelectionCandidateSet<'tcx>, + ) { + let self_ty = self.infcx().shallow_resolve(obligation.self_ty().skip_binder()); + match self_ty.kind() { + ty::Tuple(_) => { + candidates.vec.push(TupleCandidate); + } + ty::Infer(ty::TyVar(_)) => { + candidates.ambiguous = true; + } + ty::Bool + | ty::Char + | ty::Int(_) + | ty::Uint(_) + | ty::Float(_) + | ty::Adt(_, _) + | ty::Foreign(_) + | ty::Str + | ty::Array(_, _) + | ty::Slice(_) + | ty::RawPtr(_) + | ty::Ref(_, _, _) + | ty::FnDef(_, _) + | ty::FnPtr(_) + | ty::Dynamic(_, _, _) + | ty::Closure(_, _) + | ty::Generator(_, _, _) + | ty::GeneratorWitness(_) + | ty::Never + | ty::Projection(_) + | ty::Opaque(_, _) + | ty::Param(_) + | ty::Bound(_, _) + | ty::Error(_) + | ty::Infer(_) + | ty::Placeholder(_) => {} + } + } } diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs index 2a1099fc82a..27fbfb6dd21 100644 --- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs +++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs @@ -11,8 +11,8 @@ use rustc_hir::lang_items::LangItem; use rustc_index::bit_set::GrowableBitSet; use rustc_infer::infer::InferOk; use rustc_infer::infer::LateBoundRegionConversionTime::HigherRankedType; -use rustc_middle::ty::subst::{GenericArg, GenericArgKind, InternalSubsts, Subst, SubstsRef}; use rustc_middle::ty::{self, GenericParamDefKind, Ty, TyCtxt}; +use rustc_middle::ty::{GenericArg, GenericArgKind, InternalSubsts, SubstsRef}; use rustc_middle::ty::{ToPolyTraitRef, ToPredicate}; use rustc_span::def_id::DefId; @@ -68,10 +68,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { ImplSource::AutoImpl(data) } - ProjectionCandidate(idx) => { + ProjectionCandidate(idx, constness) => { let obligations = self.confirm_projection_candidate(obligation, idx)?; - // FIXME(jschievink): constness - ImplSource::Param(obligations, ty::BoundConstness::NotConst) + ImplSource::Param(obligations, constness) } ObjectCandidate(idx) => { @@ -126,6 +125,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let data = self.confirm_const_destruct_candidate(obligation, def_id)?; ImplSource::ConstDestruct(data) } + + TupleCandidate => ImplSource::Tuple, }; if !obligation.predicate.is_const_if_const() { @@ -279,29 +280,17 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let predicate = obligation.predicate; let type_at = |i| predicate.map_bound(|p| p.trait_ref.substs.type_at(i)); - let bool_at = |i| { - predicate - .skip_binder() - .trait_ref - .substs - .const_at(i) - .try_eval_bool(self.tcx(), obligation.param_env) - .unwrap_or(true) - }; + let const_at = |i| predicate.skip_binder().trait_ref.substs.const_at(i); let src_and_dst = predicate.map_bound(|p| rustc_transmute::Types { - src: p.trait_ref.substs.type_at(1), dst: p.trait_ref.substs.type_at(0), + src: p.trait_ref.substs.type_at(1), }); let scope = type_at(2).skip_binder(); - let assume = rustc_transmute::Assume { - alignment: bool_at(3), - lifetimes: bool_at(4), - validity: bool_at(5), - visibility: bool_at(6), - }; + let assume = + rustc_transmute::Assume::from_const(self.infcx.tcx, obligation.param_env, const_at(3)); let cause = obligation.cause.clone(); @@ -629,7 +618,36 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { ) .map_bound(|(trait_ref, _)| trait_ref); - let nested = self.confirm_poly_trait_refs(obligation, trait_ref)?; + let mut nested = self.confirm_poly_trait_refs(obligation, trait_ref)?; + + // Confirm the `type Output: Sized;` bound that is present on `FnOnce` + let cause = obligation.derived_cause(BuiltinDerivedObligation); + // The binder on the Fn obligation is "less" important than the one on + // the signature, as evidenced by how we treat it during projection. + // The safe thing to do here is to liberate it, though, which should + // have no worse effect than skipping the binder here. + let liberated_fn_ty = self.infcx.replace_bound_vars_with_placeholders(obligation.self_ty()); + let output_ty = self + .infcx + .replace_bound_vars_with_placeholders(liberated_fn_ty.fn_sig(self.tcx()).output()); + let output_ty = normalize_with_depth_to( + self, + obligation.param_env, + cause.clone(), + obligation.recursion_depth, + output_ty, + &mut nested, + ); + let tr = ty::Binder::dummy(ty::TraitRef::new( + self.tcx().require_lang_item(LangItem::Sized, None), + self.tcx().mk_substs_trait(output_ty, &[]), + )); + nested.push(Obligation::new( + cause, + obligation.param_env, + tr.to_poly_trait_predicate().to_predicate(self.tcx()), + )); + Ok(ImplSourceFnPointerData { fn_ty: self_ty, nested }) } @@ -794,7 +812,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let upcast_trait_ref; match (source.kind(), target.kind()) { // TraitA+Kx+'a -> TraitB+Ky+'b (trait upcasting coercion). - (&ty::Dynamic(ref data_a, r_a), &ty::Dynamic(ref data_b, r_b)) => { + (&ty::Dynamic(ref data_a, r_a, repr_a), &ty::Dynamic(ref data_b, r_b, repr_b)) + if repr_a == repr_b => + { // See `assemble_candidates_for_unsizing` for more info. // We already checked the compatibility of auto traits within `assemble_candidates_for_unsizing`. let principal_a = data_a.principal().unwrap(); @@ -820,7 +840,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { .map(ty::Binder::dummy), ); let existential_predicates = tcx.mk_poly_existential_predicates(iter); - let source_trait = tcx.mk_dynamic(existential_predicates, r_b); + let source_trait = tcx.mk_dynamic(existential_predicates, r_b, repr_b); // Require that the traits involved in this upcast are **equal**; // only the **lifetime bound** is changed. @@ -898,7 +918,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let mut nested = vec![]; match (source.kind(), target.kind()) { // Trait+Kx+'a -> Trait+Ky+'b (auto traits and lifetime subtyping). - (&ty::Dynamic(ref data_a, r_a), &ty::Dynamic(ref data_b, r_b)) => { + (&ty::Dynamic(ref data_a, r_a, ty::Dyn), &ty::Dynamic(ref data_b, r_b, ty::Dyn)) => { // See `assemble_candidates_for_unsizing` for more info. // We already checked the compatibility of auto traits within `assemble_candidates_for_unsizing`. let iter = data_a @@ -917,7 +937,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { .map(ty::Binder::dummy), ); let existential_predicates = tcx.mk_poly_existential_predicates(iter); - let source_trait = tcx.mk_dynamic(existential_predicates, r_b); + let source_trait = tcx.mk_dynamic(existential_predicates, r_b, ty::Dyn); // Require that the traits involved in this upcast are **equal**; // only the **lifetime bound** is changed. @@ -944,7 +964,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { } // `T` -> `Trait` - (_, &ty::Dynamic(ref data, r)) => { + (_, &ty::Dynamic(ref data, r, ty::Dyn)) => { let mut object_dids = data.auto_traits().chain(data.principal_def_id()); if let Some(did) = object_dids.find(|did| !tcx.is_object_safe(*did)) { return Err(TraitNotObjectSafe(did)); @@ -1047,9 +1067,25 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { return Err(Unimplemented); } - // Extract `TailField<T>` and `TailField<U>` from `Struct<T>` and `Struct<U>`. - let source_tail = tail_field_ty.subst(tcx, substs_a); - let target_tail = tail_field_ty.subst(tcx, substs_b); + // Extract `TailField<T>` and `TailField<U>` from `Struct<T>` and `Struct<U>`, + // normalizing in the process, since `type_of` returns something directly from + // astconv (which means it's un-normalized). + let source_tail = normalize_with_depth_to( + self, + obligation.param_env, + obligation.cause.clone(), + obligation.recursion_depth + 1, + tail_field_ty.subst(tcx, substs_a), + &mut nested, + ); + let target_tail = normalize_with_depth_to( + self, + obligation.param_env, + obligation.cause.clone(), + obligation.recursion_depth + 1, + tail_field_ty.subst(tcx, substs_b), + &mut nested, + ); // Check that the source struct with the target's // unsizing parameters is equal to the target. @@ -1188,6 +1224,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { | ty::Never | ty::Foreign(_) => {} + // `ManuallyDrop` is trivially drop + ty::Adt(def, _) if Some(def.did()) == tcx.lang_items().manually_drop() => {} + // These types are built-in, so we can fast-track by registering // nested predicates for their constituent type(s) ty::Array(ty, _) | ty::Slice(ty) => { diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs index 46b50dd92f1..5e32a27cdb1 100644 --- a/compiler/rustc_trait_selection/src/traits/select/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs @@ -37,7 +37,7 @@ use rustc_middle::ty::fast_reject::{DeepRejectCtxt, TreatParams}; use rustc_middle::ty::fold::BottomUpFolder; use rustc_middle::ty::print::with_no_trimmed_paths; use rustc_middle::ty::relate::TypeRelation; -use rustc_middle::ty::subst::{Subst, SubstsRef}; +use rustc_middle::ty::SubstsRef; use rustc_middle::ty::{self, EarlyBinder, PolyProjectionPredicate, ToPolyTraitRef, ToPredicate}; use rustc_middle::ty::{Ty, TyCtxt, TypeFoldable, TypeVisitable}; use rustc_span::symbol::sym; @@ -226,13 +226,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { } pub fn intercrate(infcx: &'cx InferCtxt<'cx, 'tcx>) -> SelectionContext<'cx, 'tcx> { - SelectionContext { - infcx, - freshener: infcx.freshener_keep_static(), - intercrate: true, - intercrate_ambiguity_causes: None, - query_mode: TraitQueryMode::Standard, - } + SelectionContext { intercrate: true, ..SelectionContext::new(infcx) } } pub fn with_query_mode( @@ -240,13 +234,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { query_mode: TraitQueryMode, ) -> SelectionContext<'cx, 'tcx> { debug!(?query_mode, "with_query_mode"); - SelectionContext { - infcx, - freshener: infcx.freshener_keep_static(), - intercrate: false, - intercrate_ambiguity_causes: None, - query_mode, - } + SelectionContext { query_mode, ..SelectionContext::new(infcx) } } /// Enables tracking of intercrate ambiguity causes. See @@ -295,7 +283,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { /// Attempts to satisfy the obligation. If successful, this will affect the surrounding /// type environment by performing unification. - #[instrument(level = "debug", skip(self))] + #[instrument(level = "debug", skip(self), ret)] pub fn select( &mut self, obligation: &TraitObligation<'tcx>, @@ -325,10 +313,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { Err(SelectionError::Overflow(OverflowError::Canonical)) } Err(e) => Err(e), - Ok(candidate) => { - debug!(?candidate, "confirmed"); - Ok(Some(candidate)) - } + Ok(candidate) => Ok(Some(candidate)), } } @@ -435,6 +420,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { level = "debug", skip(self, previous_stack), fields(previous_stack = ?previous_stack.head()) + ret, )] fn evaluate_predicate_recursively<'o>( &mut self, @@ -450,7 +436,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { None => self.check_recursion_limit(&obligation, &obligation)?, } - let result = ensure_sufficient_stack(|| { + ensure_sufficient_stack(|| { let bound_predicate = obligation.predicate.kind(); match bound_predicate.skip_binder() { ty::PredicateKind::Trait(t) => { @@ -464,15 +450,15 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let p = bound_predicate.rebind(p); // Does this code ever run? match self.infcx.subtype_predicate(&obligation.cause, obligation.param_env, p) { - Some(Ok(InferOk { mut obligations, .. })) => { + Ok(Ok(InferOk { mut obligations, .. })) => { self.add_depth(obligations.iter_mut(), obligation.recursion_depth); self.evaluate_predicates_recursively( previous_stack, obligations.into_iter(), ) } - Some(Err(_)) => Ok(EvaluatedToErr), - None => Ok(EvaluatedToAmbig), + Ok(Err(_)) => Ok(EvaluatedToErr), + Err(..) => Ok(EvaluatedToAmbig), } } @@ -480,15 +466,15 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let p = bound_predicate.rebind(p); // Does this code ever run? match self.infcx.coerce_predicate(&obligation.cause, obligation.param_env, p) { - Some(Ok(InferOk { mut obligations, .. })) => { + Ok(Ok(InferOk { mut obligations, .. })) => { self.add_depth(obligations.iter_mut(), obligation.recursion_depth); self.evaluate_predicates_recursively( previous_stack, obligations.into_iter(), ) } - Some(Err(_)) => Ok(EvaluatedToErr), - None => Ok(EvaluatedToAmbig), + Ok(Err(_)) => Ok(EvaluatedToErr), + Err(..) => Ok(EvaluatedToAmbig), } } @@ -701,11 +687,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { if let (ty::ConstKind::Unevaluated(a), ty::ConstKind::Unevaluated(b)) = (c1.kind(), c2.kind()) { - if self.infcx.try_unify_abstract_consts( - a.shrink(), - b.shrink(), - obligation.param_env, - ) { + if self.infcx.try_unify_abstract_consts(a, b, obligation.param_env) { return Ok(EvaluatedToOk); } } @@ -760,14 +742,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { bug!("TypeWellFormedFromEnv is only used for chalk") } } - }); - - debug!("finished: {:?} from {:?}", result, obligation); - - result + }) } - #[instrument(skip(self, previous_stack), level = "debug")] + #[instrument(skip(self, previous_stack), level = "debug", ret)] fn evaluate_trait_predicate_recursively<'o>( &mut self, previous_stack: TraitObligationStackList<'o, 'tcx>, @@ -798,12 +776,12 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { // If a trait predicate is in the (local or global) evaluation cache, // then we know it holds without cycles. if let Some(result) = self.check_evaluation_cache(param_env, fresh_trait_pred) { - debug!(?result, "CACHE HIT"); + debug!("CACHE HIT"); return Ok(result); } if let Some(result) = stack.cache().get_provisional(fresh_trait_pred) { - debug!(?result, "PROVISIONAL CACHE HIT"); + debug!("PROVISIONAL CACHE HIT"); stack.update_reached_depth(result.reached_depth); return Ok(result.result); } @@ -826,11 +804,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let reached_depth = stack.reached_depth.get(); if reached_depth >= stack.depth { - debug!(?result, "CACHE MISS"); + debug!("CACHE MISS"); self.insert_evaluation_cache(param_env, fresh_trait_pred, dep_node, result); stack.cache().on_completion(stack.dfn); } else { - debug!(?result, "PROVISIONAL"); + debug!("PROVISIONAL"); debug!( "caching provisionally because {:?} \ is a cycle participant (at depth {}, reached depth {})", @@ -1023,7 +1001,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { #[instrument( level = "debug", skip(self, stack), - fields(depth = stack.obligation.recursion_depth) + fields(depth = stack.obligation.recursion_depth), + ret )] fn evaluate_candidate<'o>( &mut self, @@ -1056,7 +1035,6 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { result = result.max(EvaluatedToOkModuloRegions); } - debug!(?result); Ok(result) } @@ -1202,6 +1180,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { ImplCandidate(def_id) if tcx.constness(def_id) == hir::Constness::Const => {} // const param ParamCandidate(trait_pred) if trait_pred.is_const_if_const() => {} + // const projection + ProjectionCandidate(_, ty::BoundConstness::ConstIfConst) => {} // auto trait impl AutoImplCandidate(..) => {} // generator, this will raise error in other places @@ -1405,11 +1385,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { /// a projection, look at the bounds of `T::Bar`, see if we can find a /// `Baz` bound. We return indexes into the list returned by /// `tcx.item_bounds` for any applicable bounds. - #[instrument(level = "debug", skip(self))] + #[instrument(level = "debug", skip(self), ret)] fn match_projection_obligation_against_definition_bounds( &mut self, obligation: &TraitObligation<'tcx>, - ) -> smallvec::SmallVec<[usize; 2]> { + ) -> smallvec::SmallVec<[(usize, ty::BoundConstness); 2]> { let poly_trait_predicate = self.infcx().resolve_vars_if_possible(obligation.predicate); let placeholder_trait_predicate = self.infcx().replace_bound_vars_with_placeholders(poly_trait_predicate); @@ -1435,7 +1415,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { // unnecessary ambiguity. let mut distinct_normalized_bounds = FxHashSet::default(); - let matching_bounds = bounds + bounds .iter() .enumerate() .filter_map(|(idx, bound)| { @@ -1457,15 +1437,12 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { _ => false, } }) { - return Some(idx); + return Some((idx, pred.constness)); } } None }) - .collect(); - - debug!(?matching_bounds); - matching_bounds + .collect() } /// Equates the trait in `obligation` with trait bound. If the two traits @@ -1618,7 +1595,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { }; // (*) Prefer `BuiltinCandidate { has_nested: false }`, `PointeeCandidate`, - // `DiscriminantKindCandidate`, and `ConstDestructCandidate` to anything else. + // `DiscriminantKindCandidate`, `ConstDestructCandidate`, and `TupleCandidate` + // to anything else. // // This is a fix for #53123 and prevents winnowing from accidentally extending the // lifetime of a variable. @@ -1638,7 +1616,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { BuiltinCandidate { has_nested: false } | DiscriminantKindCandidate | PointeeCandidate - | ConstDestructCandidate(_), + | ConstDestructCandidate(_) + | TupleCandidate, _, ) => true, ( @@ -1646,7 +1625,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { BuiltinCandidate { has_nested: false } | DiscriminantKindCandidate | PointeeCandidate - | ConstDestructCandidate(_), + | ConstDestructCandidate(_) + | TupleCandidate, ) => false, (ParamCandidate(other), ParamCandidate(victim)) => { @@ -1693,9 +1673,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { | BuiltinCandidate { .. } | TraitAliasCandidate(..) | ObjectCandidate(_) - | ProjectionCandidate(_), + | ProjectionCandidate(..), ) => !is_global(cand), - (ObjectCandidate(_) | ProjectionCandidate(_), ParamCandidate(ref cand)) => { + (ObjectCandidate(_) | ProjectionCandidate(..), ParamCandidate(ref cand)) => { // Prefer these to a global where-clause bound // (see issue #50825). is_global(cand) @@ -1717,20 +1697,20 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { is_global(cand) && other.evaluation.must_apply_modulo_regions() } - (ProjectionCandidate(i), ProjectionCandidate(j)) + (ProjectionCandidate(i, _), ProjectionCandidate(j, _)) | (ObjectCandidate(i), ObjectCandidate(j)) => { // Arbitrarily pick the lower numbered candidate for backwards // compatibility reasons. Don't let this affect inference. i < j && !needs_infer } - (ObjectCandidate(_), ProjectionCandidate(_)) - | (ProjectionCandidate(_), ObjectCandidate(_)) => { + (ObjectCandidate(_), ProjectionCandidate(..)) + | (ProjectionCandidate(..), ObjectCandidate(_)) => { bug!("Have both object and projection candidate") } // Arbitrarily give projection and object candidates priority. ( - ObjectCandidate(_) | ProjectionCandidate(_), + ObjectCandidate(_) | ProjectionCandidate(..), ImplCandidate(..) | ClosureCandidate | GeneratorCandidate @@ -1752,7 +1732,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { | TraitUpcastingUnsizeCandidate(_) | BuiltinCandidate { .. } | TraitAliasCandidate(..), - ObjectCandidate(_) | ProjectionCandidate(_), + ObjectCandidate(_) | ProjectionCandidate(..), ) => false, (&ImplCandidate(other_def), &ImplCandidate(victim_def)) => { @@ -1871,6 +1851,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { | ty::Array(..) | ty::Closure(..) | ty::Never + | ty::Dynamic(_, _, ty::DynStar) | ty::Error(_) => { // safe for everything Where(ty::Binder::dummy(Vec::new())) @@ -1937,8 +1918,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { ty::Dynamic(..) | ty::Str | ty::Slice(..) - | ty::Generator(..) - | ty::GeneratorWitness(..) + | ty::Generator(_, _, hir::Movability::Static) | ty::Foreign(..) | ty::Ref(_, _, hir::Mutability::Mut) => None, @@ -1947,6 +1927,43 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { Where(obligation.predicate.rebind(tys.iter().collect())) } + ty::Generator(_, substs, hir::Movability::Movable) => { + if self.tcx().features().generator_clone { + let resolved_upvars = + self.infcx.shallow_resolve(substs.as_generator().tupled_upvars_ty()); + let resolved_witness = + self.infcx.shallow_resolve(substs.as_generator().witness()); + if resolved_upvars.is_ty_var() || resolved_witness.is_ty_var() { + // Not yet resolved. + Ambiguous + } else { + let all = substs + .as_generator() + .upvar_tys() + .chain(iter::once(substs.as_generator().witness())) + .collect::<Vec<_>>(); + Where(obligation.predicate.rebind(all)) + } + } else { + None + } + } + + ty::GeneratorWitness(binder) => { + let witness_tys = binder.skip_binder(); + for witness_ty in witness_tys.iter() { + let resolved = self.infcx.shallow_resolve(witness_ty); + if resolved.is_ty_var() { + return Ambiguous; + } + } + // (*) binder moved here + let all_vars = self.tcx().mk_bound_variable_kinds( + obligation.predicate.bound_vars().iter().chain(binder.bound_vars().iter()), + ); + Where(ty::Binder::bind_with_vars(witness_tys.to_vec(), all_vars)) + } + ty::Closure(_, substs) => { // (*) binder moved here let ty = self.infcx.shallow_resolve(substs.as_closure().tupled_upvars_ty()); @@ -2153,7 +2170,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { } } - #[tracing::instrument(level = "debug", skip(self))] + #[instrument(level = "debug", skip(self), ret)] fn match_impl( &mut self, impl_def_id: DefId, @@ -2194,17 +2211,16 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { .at(&cause, obligation.param_env) .define_opaque_types(false) .eq(placeholder_obligation_trait_ref, impl_trait_ref) - .map_err(|e| debug!("match_impl: failed eq_trait_refs due to `{}`", e))?; + .map_err(|e| debug!("match_impl: failed eq_trait_refs due to `{e}`"))?; nested_obligations.extend(obligations); if !self.intercrate && self.tcx().impl_polarity(impl_def_id) == ty::ImplPolarity::Reservation { - debug!("match_impl: reservation impls only apply in intercrate mode"); + debug!("reservation impls only apply in intercrate mode"); return Err(()); } - debug!(?impl_substs, ?nested_obligations, "match_impl: success"); Ok(Normalized { value: impl_substs, obligations: nested_obligations }) } @@ -2335,7 +2351,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { /// impl or trait. The obligations are substituted and fully /// normalized. This is used when confirming an impl or default /// impl. - #[tracing::instrument(level = "debug", skip(self, cause, param_env))] + #[instrument(level = "debug", skip(self, cause, param_env))] fn impl_or_trait_obligations( &mut self, cause: &ObligationCause<'tcx>, diff --git a/compiler/rustc_trait_selection/src/traits/specialize/mod.rs b/compiler/rustc_trait_selection/src/traits/specialize/mod.rs index 0f76fef0eee..56a88749c46 100644 --- a/compiler/rustc_trait_selection/src/traits/specialize/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/specialize/mod.rs @@ -12,14 +12,15 @@ pub mod specialization_graph; use specialization_graph::GraphExt; +use crate::errors::NegativePositiveConflict; use crate::infer::{InferCtxt, InferOk, TyCtxtInferExt}; use crate::traits::select::IntercrateAmbiguityCause; use crate::traits::{self, coherence, FutureCompatOverlapErrorKind, ObligationCause}; use rustc_data_structures::fx::{FxHashSet, FxIndexSet}; use rustc_errors::{struct_span_err, EmissionGuarantee, LintDiagnosticBuilder}; use rustc_hir::def_id::{DefId, LocalDefId}; -use rustc_middle::ty::subst::{InternalSubsts, Subst, SubstsRef}; use rustc_middle::ty::{self, ImplSubject, TyCtxt}; +use rustc_middle::ty::{InternalSubsts, SubstsRef}; use rustc_session::lint::builtin::COHERENCE_LEAK_CHECK; use rustc_session::lint::builtin::ORDER_DEPENDENT_TRAIT_OBJECTS; use rustc_span::{Span, DUMMY_SP}; @@ -327,35 +328,13 @@ fn report_negative_positive_conflict( positive_impl_def_id: DefId, sg: &mut specialization_graph::Graph, ) { - let impl_span = tcx.def_span(local_impl_def_id); - - let mut err = struct_span_err!( - tcx.sess, - impl_span, - E0751, - "found both positive and negative implementation of trait `{}`{}:", - overlap.trait_desc, - overlap.self_desc.clone().map_or_else(String::new, |ty| format!(" for type `{}`", ty)) - ); - - match tcx.span_of_impl(negative_impl_def_id) { - Ok(span) => { - err.span_label(span, "negative implementation here"); - } - Err(cname) => { - err.note(&format!("negative implementation in crate `{}`", cname)); - } - } - - match tcx.span_of_impl(positive_impl_def_id) { - Ok(span) => { - err.span_label(span, "positive implementation here"); - } - Err(cname) => { - err.note(&format!("positive implementation in crate `{}`", cname)); - } - } - + let mut err = tcx.sess.create_err(NegativePositiveConflict { + impl_span: tcx.def_span(local_impl_def_id), + trait_desc: &overlap.trait_desc, + self_desc: &overlap.self_desc, + negative_impl_span: tcx.span_of_impl(negative_impl_def_id), + positive_impl_span: tcx.span_of_impl(positive_impl_def_id), + }); sg.has_errored = Some(err.emit()); } diff --git a/compiler/rustc_trait_selection/src/traits/util.rs b/compiler/rustc_trait_selection/src/traits/util.rs index 0f5dff01c66..5206e9f649b 100644 --- a/compiler/rustc_trait_selection/src/traits/util.rs +++ b/compiler/rustc_trait_selection/src/traits/util.rs @@ -5,8 +5,8 @@ use smallvec::SmallVec; use rustc_data_structures::fx::FxHashSet; use rustc_hir::def_id::DefId; -use rustc_middle::ty::subst::{GenericArg, Subst, SubstsRef}; use rustc_middle::ty::{self, ImplSubject, ToPredicate, Ty, TyCtxt, TypeVisitable}; +use rustc_middle::ty::{GenericArg, SubstsRef}; use super::{Normalized, Obligation, ObligationCause, PredicateObligation, SelectionContext}; pub use rustc_infer::traits::{self, util::*}; diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs index 4bd179d2391..9722b48a68a 100644 --- a/compiler/rustc_trait_selection/src/traits/wf.rs +++ b/compiler/rustc_trait_selection/src/traits/wf.rs @@ -101,6 +101,7 @@ pub fn trait_obligations<'a, 'tcx>( wf.normalize(infcx) } +#[instrument(skip(infcx), ret)] pub fn predicate_obligations<'a, 'tcx>( infcx: &InferCtxt<'a, 'tcx>, param_env: ty::ParamEnv<'tcx>, @@ -129,9 +130,9 @@ pub fn predicate_obligations<'a, 'tcx>( } ty::PredicateKind::Projection(t) => { wf.compute_projection(t.projection_ty); - wf.compute(match t.term { - ty::Term::Ty(ty) => ty.into(), - ty::Term::Const(c) => c.into(), + wf.compute(match t.term.unpack() { + ty::TermKind::Ty(ty) => ty.into(), + ty::TermKind::Const(c) => c.into(), }) } ty::PredicateKind::WellFormed(arg) => { @@ -391,7 +392,8 @@ impl<'tcx> WfPredicates<'tcx> { // `i32: Clone` // `i32: Copy` // ] - let obligations = self.nominal_obligations(data.item_def_id, data.substs); + // Projection types do not require const predicates. + let obligations = self.nominal_obligations_without_const(data.item_def_id, data.substs); self.out.extend(obligations); let tcx = self.tcx(); @@ -434,11 +436,13 @@ impl<'tcx> WfPredicates<'tcx> { } /// Pushes all the predicates needed to validate that `ty` is WF into `out`. + #[instrument(level = "debug", skip(self))] fn compute(&mut self, arg: GenericArg<'tcx>) { let mut walker = arg.walk(); let param_env = self.param_env; let depth = self.recursion_depth; while let Some(arg) = walker.next() { + debug!(?arg, ?self.out); let ty = match arg.unpack() { GenericArgKind::Type(ty) => ty, @@ -453,7 +457,7 @@ impl<'tcx> WfPredicates<'tcx> { self.out.extend(obligations); let predicate = - ty::Binder::dummy(ty::PredicateKind::ConstEvaluatable(uv.shrink())) + ty::Binder::dummy(ty::PredicateKind::ConstEvaluatable(uv)) .to_predicate(self.tcx()); let cause = self.cause(traits::WellFormed(None)); self.out.push(traits::Obligation::with_depth( @@ -488,6 +492,8 @@ impl<'tcx> WfPredicates<'tcx> { } }; + debug!("wf bounds for ty={:?} ty.kind={:#?}", ty, ty.kind()); + match *ty.kind() { ty::Bool | ty::Char @@ -634,7 +640,7 @@ impl<'tcx> WfPredicates<'tcx> { } } - ty::Dynamic(data, r) => { + ty::Dynamic(data, r, _) => { // WfObject // // Here, we defer WF checking due to higher-ranked @@ -686,6 +692,8 @@ impl<'tcx> WfPredicates<'tcx> { )); } } + + debug!(?self.out); } } @@ -841,7 +849,7 @@ pub fn object_region_bounds<'tcx>( /// /// Requires that trait definitions have been processed so that we can /// elaborate predicates and walk supertraits. -#[instrument(skip(tcx, predicates), level = "debug")] +#[instrument(skip(tcx, predicates), level = "debug", ret)] pub(crate) fn required_region_bounds<'tcx>( tcx: TyCtxt<'tcx>, erased_self_ty: Ty<'tcx>, |