diff options
Diffstat (limited to 'compiler/rustc_hir_typeck/src/method/mod.rs')
-rw-r--r-- | compiler/rustc_hir_typeck/src/method/mod.rs | 248 |
1 files changed, 88 insertions, 160 deletions
diff --git a/compiler/rustc_hir_typeck/src/method/mod.rs b/compiler/rustc_hir_typeck/src/method/mod.rs index a2ca5c3b7..b810a967a 100644 --- a/compiler/rustc_hir_typeck/src/method/mod.rs +++ b/compiler/rustc_hir_typeck/src/method/mod.rs @@ -11,7 +11,7 @@ pub use self::suggest::SelfSource; pub use self::MethodError::*; use crate::errors::OpMethodGenericParams; -use crate::{Expectation, FnCtxt}; +use crate::FnCtxt; use rustc_data_structures::sync::Lrc; use rustc_errors::{Applicability, Diagnostic}; use rustc_hir as hir; @@ -57,7 +57,12 @@ pub enum MethodError<'tcx> { PrivateMatch(DefKind, DefId, Vec<DefId>), // Found a `Self: Sized` bound where `Self` is a trait object. - IllegalSizedBound(Vec<DefId>, bool, Span), + IllegalSizedBound { + candidates: Vec<DefId>, + needs_mut: bool, + bound_span: Span, + self_expr: &'tcx hir::Expr<'tcx>, + }, // Found a match, but the return type is wrong BadReturnType, @@ -92,10 +97,12 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { self_ty: Ty<'tcx>, call_expr_id: hir::HirId, allow_private: bool, + return_type: Option<Ty<'tcx>>, ) -> bool { match self.probe_for_name( probe::Mode::MethodCall, method_name, + return_type, IsSuggestion(false), self_ty, call_expr_id, @@ -112,8 +119,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { Err(NoMatch(..)) => false, Err(Ambiguity(..)) => true, Err(PrivateMatch(..)) => allow_private, - Err(IllegalSizedBound(..)) => true, - Err(BadReturnType) => bug!("no return type expectations but got BadReturnType"), + Err(IllegalSizedBound { .. }) => true, + Err(BadReturnType) => false, } } @@ -125,17 +132,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { msg: &str, method_name: Ident, self_ty: Ty<'tcx>, - call_expr: &hir::Expr<'_>, + call_expr: &hir::Expr<'tcx>, span: Option<Span>, ) { let params = self - .probe_for_name( - probe::Mode::MethodCall, + .lookup_probe_for_diagnostic( method_name, - IsSuggestion(true), self_ty, - call_expr.hir_id, + call_expr, ProbeScope::TraitsInScope, + None, ) .map(|pick| { let sig = self.tcx.fn_sig(pick.item.def_id); @@ -192,8 +198,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { self.tcx.check_stability(pick.item.def_id, Some(call_expr.hir_id), span, None); - let result = - self.confirm_method(span, self_expr, call_expr, self_ty, pick.clone(), segment); + let result = self.confirm_method(span, self_expr, call_expr, self_ty, &pick, segment); debug!("result = {:?}", result); if let Some(span) = result.illegal_sized_bound { @@ -210,34 +215,39 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { ProbeScope::TraitsInScope, ) { Ok(ref new_pick) if pick.differs_from(new_pick) => { - needs_mut = true; + needs_mut = new_pick.self_ty.ref_mutability() != self_ty.ref_mutability(); } _ => {} } } // We probe again, taking all traits into account (not only those in scope). - let candidates = - match self.lookup_probe(segment.ident, self_ty, call_expr, ProbeScope::AllTraits) { - // If we find a different result the caller probably forgot to import a trait. - Ok(ref new_pick) if pick.differs_from(new_pick) => { - vec![new_pick.item.container_id(self.tcx)] - } - Err(Ambiguity(ref sources)) => sources - .iter() - .filter_map(|source| { - match *source { - // Note: this cannot come from an inherent impl, - // because the first probing succeeded. - CandidateSource::Impl(def) => self.tcx.trait_id_of_impl(def), - CandidateSource::Trait(_) => None, - } - }) - .collect(), - _ => Vec::new(), - }; - - return Err(IllegalSizedBound(candidates, needs_mut, span)); + let candidates = match self.lookup_probe_for_diagnostic( + segment.ident, + self_ty, + call_expr, + ProbeScope::AllTraits, + None, + ) { + // If we find a different result the caller probably forgot to import a trait. + Ok(ref new_pick) if pick.differs_from(new_pick) => { + vec![new_pick.item.container_id(self.tcx)] + } + Err(Ambiguity(ref sources)) => sources + .iter() + .filter_map(|source| { + match *source { + // Note: this cannot come from an inherent impl, + // because the first probing succeeded. + CandidateSource::Impl(def) => self.tcx.trait_id_of_impl(def), + CandidateSource::Trait(_) => None, + } + }) + .collect(), + _ => Vec::new(), + }; + + return Err(IllegalSizedBound { candidates, needs_mut, bound_span: span, self_expr }); } Ok(result.callee) @@ -248,12 +258,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { &self, method_name: Ident, self_ty: Ty<'tcx>, - call_expr: &'tcx hir::Expr<'tcx>, + call_expr: &hir::Expr<'_>, scope: ProbeScope, ) -> probe::PickResult<'tcx> { let pick = self.probe_for_name( probe::Mode::MethodCall, method_name, + None, IsSuggestion(false), self_ty, call_expr.hir_id, @@ -263,53 +274,32 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { Ok(pick) } - pub(super) fn obligation_for_method( + pub fn lookup_probe_for_diagnostic( &self, - span: Span, - trait_def_id: DefId, + method_name: Ident, self_ty: Ty<'tcx>, - opt_input_types: Option<&[Ty<'tcx>]>, - ) -> (traits::Obligation<'tcx, ty::Predicate<'tcx>>, &'tcx ty::List<ty::subst::GenericArg<'tcx>>) - { - // Construct a trait-reference `self_ty : Trait<input_tys>` - let substs = InternalSubsts::for_item(self.tcx, trait_def_id, |param, _| { - match param.kind { - GenericParamDefKind::Lifetime | GenericParamDefKind::Const { .. } => {} - GenericParamDefKind::Type { .. } => { - if param.index == 0 { - return self_ty.into(); - } else if let Some(input_types) = opt_input_types { - return input_types[param.index as usize - 1].into(); - } - } - } - self.var_for_def(span, param) - }); - - let trait_ref = ty::TraitRef::new(trait_def_id, substs); - - // Construct an obligation - let poly_trait_ref = ty::Binder::dummy(trait_ref); - ( - traits::Obligation::misc( - self.tcx, - span, - self.body_id, - self.param_env, - poly_trait_ref.without_const(), - ), - substs, - ) + call_expr: &hir::Expr<'_>, + scope: ProbeScope, + return_type: Option<Ty<'tcx>>, + ) -> probe::PickResult<'tcx> { + let pick = self.probe_for_name( + probe::Mode::MethodCall, + method_name, + return_type, + IsSuggestion(true), + self_ty, + call_expr.hir_id, + scope, + )?; + Ok(pick) } - pub(super) fn obligation_for_op_method( + pub(super) fn obligation_for_method( &self, - span: Span, + cause: ObligationCause<'tcx>, trait_def_id: DefId, self_ty: Ty<'tcx>, - opt_input_type: Option<Ty<'tcx>>, - opt_input_expr: Option<&'tcx hir::Expr<'tcx>>, - expected: Expectation<'tcx>, + opt_input_types: Option<&[Ty<'tcx>]>, ) -> (traits::Obligation<'tcx, ty::Predicate<'tcx>>, &'tcx ty::List<ty::subst::GenericArg<'tcx>>) { // Construct a trait-reference `self_ty : Trait<input_tys>` @@ -319,35 +309,24 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { GenericParamDefKind::Type { .. } => { if param.index == 0 { return self_ty.into(); - } else if let Some(input_type) = opt_input_type { - return input_type.into(); + } else if let Some(input_types) = opt_input_types { + return input_types[param.index as usize - 1].into(); } } } - self.var_for_def(span, param) + self.var_for_def(cause.span, param) }); - let trait_ref = ty::TraitRef::new(trait_def_id, substs); + let trait_ref = self.tcx.mk_trait_ref(trait_def_id, substs); // Construct an obligation let poly_trait_ref = ty::Binder::dummy(trait_ref); - let output_ty = expected.only_has_type(self).and_then(|ty| (!ty.needs_infer()).then(|| ty)); - ( traits::Obligation::new( self.tcx, - traits::ObligationCause::new( - span, - self.body_id, - traits::BinOp { - rhs_span: opt_input_expr.map(|expr| expr.span), - is_lit: opt_input_expr - .map_or(false, |expr| matches!(expr.kind, hir::ExprKind::Lit(_))), - output_ty, - }, - ), + cause, self.param_env, - poly_trait_ref, + poly_trait_ref.without_const(), ), substs, ) @@ -358,55 +337,18 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { /// In particular, it doesn't really do any probing: it simply constructs /// an obligation for a particular trait with the given self type and checks /// whether that trait is implemented. - #[instrument(level = "debug", skip(self, span))] + #[instrument(level = "debug", skip(self))] pub(super) fn lookup_method_in_trait( &self, - span: Span, + cause: ObligationCause<'tcx>, m_name: Ident, trait_def_id: DefId, self_ty: Ty<'tcx>, opt_input_types: Option<&[Ty<'tcx>]>, ) -> Option<InferOk<'tcx, MethodCallee<'tcx>>> { let (obligation, substs) = - self.obligation_for_method(span, trait_def_id, self_ty, opt_input_types); - self.construct_obligation_for_trait( - span, - m_name, - trait_def_id, - obligation, - substs, - None, - false, - ) - } - - pub(super) fn lookup_op_method_in_trait( - &self, - span: Span, - m_name: Ident, - trait_def_id: DefId, - self_ty: Ty<'tcx>, - opt_input_type: Option<Ty<'tcx>>, - opt_input_expr: Option<&'tcx hir::Expr<'tcx>>, - expected: Expectation<'tcx>, - ) -> Option<InferOk<'tcx, MethodCallee<'tcx>>> { - let (obligation, substs) = self.obligation_for_op_method( - span, - trait_def_id, - self_ty, - opt_input_type, - opt_input_expr, - expected, - ); - self.construct_obligation_for_trait( - span, - m_name, - trait_def_id, - obligation, - substs, - opt_input_expr, - true, - ) + self.obligation_for_method(cause, trait_def_id, self_ty, opt_input_types); + self.construct_obligation_for_trait(m_name, trait_def_id, obligation, substs) } // FIXME(#18741): it seems likely that we can consolidate some of this @@ -414,13 +356,10 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // of this method is basically the same as confirmation. fn construct_obligation_for_trait( &self, - span: Span, m_name: Ident, trait_def_id: DefId, obligation: traits::PredicateObligation<'tcx>, substs: &'tcx ty::List<ty::subst::GenericArg<'tcx>>, - opt_input_expr: Option<&'tcx hir::Expr<'tcx>>, - is_op: bool, ) -> Option<InferOk<'tcx, MethodCallee<'tcx>>> { debug!(?obligation); @@ -436,7 +375,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { let tcx = self.tcx; let Some(method_item) = self.associated_value(trait_def_id, m_name) else { tcx.sess.delay_span_bug( - span, + obligation.cause.span, "operator trait does not have corresponding operator method", ); return None; @@ -457,29 +396,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // Instantiate late-bound regions and substitute the trait // parameters into the method type to get the actual method type. // - // N.B., instantiate late-bound regions first so that - // `instantiate_type_scheme` can normalize associated types that - // may reference those regions. + // N.B., instantiate late-bound regions before normalizing the + // function signature so that normalization does not need to deal + // with bound regions. let fn_sig = tcx.bound_fn_sig(def_id); let fn_sig = fn_sig.subst(self.tcx, substs); - let fn_sig = self.replace_bound_vars_with_fresh_vars(span, infer::FnCall, fn_sig); - - let cause = if is_op { - ObligationCause::new( - span, - self.body_id, - traits::BinOp { - rhs_span: opt_input_expr.map(|expr| expr.span), - is_lit: opt_input_expr - .map_or(false, |expr| matches!(expr.kind, hir::ExprKind::Lit(_))), - output_ty: None, - }, - ) - } else { - traits::ObligationCause::misc(span, self.body_id) - }; + let fn_sig = + self.replace_bound_vars_with_fresh_vars(obligation.cause.span, infer::FnCall, fn_sig); - let InferOk { value, obligations: o } = self.at(&cause, self.param_env).normalize(fn_sig); + let InferOk { value, obligations: o } = + self.at(&obligation.cause, self.param_env).normalize(fn_sig); let fn_sig = { obligations.extend(o); value @@ -487,7 +413,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // Register obligations for the parameters. This will include the // `Self` parameter, which in turn has a bound of the main trait, - // so this also effectively registers `obligation` as well. (We + // so this also effectively registers `obligation` as well. (We // used to register `obligation` explicitly, but that resulted in // double error messages being reported.) // @@ -495,7 +421,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { // any late-bound regions appearing in its bounds. let bounds = self.tcx.predicates_of(def_id).instantiate(self.tcx, substs); - let InferOk { value, obligations: o } = self.at(&cause, self.param_env).normalize(bounds); + let InferOk { value, obligations: o } = + self.at(&obligation.cause, self.param_env).normalize(bounds); let bounds = { obligations.extend(o); value @@ -503,7 +430,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { assert!(!bounds.has_escaping_bound_vars()); - let predicates_cause = cause.clone(); + let predicates_cause = obligation.cause.clone(); obligations.extend(traits::predicates_for_generics( move |_, _| predicates_cause.clone(), self.param_env, @@ -518,7 +445,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { ); obligations.push(traits::Obligation::new( tcx, - cause, + obligation.cause, self.param_env, ty::Binder::dummy(ty::PredicateKind::WellFormed(method_ty.into())), )); @@ -584,6 +511,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> { let pick = self.probe_for_name( probe::Mode::Path, method_name, + None, IsSuggestion(false), self_ty, expr_id, |