| // Copyright 2014 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| use check::{Inherited, FnCtxt}; |
| use constrained_type_params::{identify_constrained_type_params, Parameter}; |
| |
| use hir::def_id::DefId; |
| use rustc::traits::{self, ObligationCauseCode}; |
| use rustc::ty::{self, Lift, Ty, TyCtxt}; |
| use rustc::ty::util::ExplicitSelf; |
| use rustc::util::nodemap::{FxHashSet, FxHashMap}; |
| use rustc::middle::lang_items; |
| |
| use syntax::ast; |
| use syntax::feature_gate::{self, GateIssue}; |
| use syntax_pos::Span; |
| use errors::{DiagnosticBuilder, DiagnosticId}; |
| |
| use rustc::hir::intravisit::{self, Visitor, NestedVisitorMap}; |
| use rustc::hir; |
| |
| pub struct CheckTypeWellFormedVisitor<'a, 'tcx:'a> { |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| code: ObligationCauseCode<'tcx>, |
| } |
| |
| /// Helper type of a temporary returned by .for_item(...). |
| /// Necessary because we can't write the following bound: |
| /// F: for<'b, 'tcx> where 'gcx: 'tcx FnOnce(FnCtxt<'b, 'gcx, 'tcx>). |
| struct CheckWfFcxBuilder<'a, 'gcx: 'a+'tcx, 'tcx: 'a> { |
| inherited: super::InheritedBuilder<'a, 'gcx, 'tcx>, |
| code: ObligationCauseCode<'gcx>, |
| id: ast::NodeId, |
| span: Span, |
| param_env: ty::ParamEnv<'tcx>, |
| } |
| |
| impl<'a, 'gcx, 'tcx> CheckWfFcxBuilder<'a, 'gcx, 'tcx> { |
| fn with_fcx<F>(&'tcx mut self, f: F) where |
| F: for<'b> FnOnce(&FnCtxt<'b, 'gcx, 'tcx>, |
| &mut CheckTypeWellFormedVisitor<'b, 'gcx>) -> Vec<Ty<'tcx>> |
| { |
| let code = self.code.clone(); |
| let id = self.id; |
| let span = self.span; |
| let param_env = self.param_env; |
| self.inherited.enter(|inh| { |
| let fcx = FnCtxt::new(&inh, param_env, id); |
| let wf_tys = f(&fcx, &mut CheckTypeWellFormedVisitor { |
| tcx: fcx.tcx.global_tcx(), |
| code, |
| }); |
| fcx.select_all_obligations_or_error(); |
| fcx.regionck_item(id, span, &wf_tys); |
| }); |
| } |
| } |
| |
| impl<'a, 'gcx> CheckTypeWellFormedVisitor<'a, 'gcx> { |
| pub fn new(tcx: TyCtxt<'a, 'gcx, 'gcx>) |
| -> CheckTypeWellFormedVisitor<'a, 'gcx> { |
| CheckTypeWellFormedVisitor { |
| tcx, |
| code: ObligationCauseCode::MiscObligation |
| } |
| } |
| |
| /// Checks that the field types (in a struct def'n) or argument types (in an enum def'n) are |
| /// well-formed, meaning that they do not require any constraints not declared in the struct |
| /// definition itself. For example, this definition would be illegal: |
| /// |
| /// struct Ref<'a, T> { x: &'a T } |
| /// |
| /// because the type did not declare that `T:'a`. |
| /// |
| /// We do this check as a pre-pass before checking fn bodies because if these constraints are |
| /// not included it frequently leads to confusing errors in fn bodies. So it's better to check |
| /// the types first. |
| fn check_item_well_formed(&mut self, item: &hir::Item) { |
| let tcx = self.tcx; |
| debug!("check_item_well_formed(it.id={}, it.name={})", |
| item.id, |
| tcx.item_path_str(tcx.hir.local_def_id(item.id))); |
| |
| match item.node { |
| // Right now we check that every default trait implementation |
| // has an implementation of itself. Basically, a case like: |
| // |
| // `impl Trait for T {}` |
| // |
| // has a requirement of `T: Trait` which was required for default |
| // method implementations. Although this could be improved now that |
| // there's a better infrastructure in place for this, it's being left |
| // for a follow-up work. |
| // |
| // Since there's such a requirement, we need to check *just* positive |
| // implementations, otherwise things like: |
| // |
| // impl !Send for T {} |
| // |
| // won't be allowed unless there's an *explicit* implementation of `Send` |
| // for `T` |
| hir::ItemImpl(_, polarity, defaultness, _, ref trait_ref, ref self_ty, _) => { |
| let is_auto = tcx.impl_trait_ref(tcx.hir.local_def_id(item.id)) |
| .map_or(false, |trait_ref| tcx.trait_is_auto(trait_ref.def_id)); |
| if let (hir::Defaultness::Default { .. }, true) = (defaultness, is_auto) { |
| tcx.sess.span_err(item.span, "impls of auto traits cannot be default"); |
| } |
| if polarity == hir::ImplPolarity::Positive { |
| self.check_impl(item, self_ty, trait_ref); |
| } else { |
| // FIXME(#27579) what amount of WF checking do we need for neg impls? |
| if trait_ref.is_some() && !is_auto { |
| span_err!(tcx.sess, item.span, E0192, |
| "negative impls are only allowed for \ |
| auto traits (e.g., `Send` and `Sync`)") |
| } |
| } |
| } |
| hir::ItemFn(..) => { |
| self.check_item_fn(item); |
| } |
| hir::ItemStatic(..) => { |
| self.check_item_type(item); |
| } |
| hir::ItemConst(..) => { |
| self.check_item_type(item); |
| } |
| hir::ItemStruct(ref struct_def, ref ast_generics) => { |
| self.check_type_defn(item, false, |fcx| { |
| vec![fcx.non_enum_variant(struct_def)] |
| }); |
| |
| self.check_variances_for_type_defn(item, ast_generics); |
| } |
| hir::ItemUnion(ref struct_def, ref ast_generics) => { |
| self.check_type_defn(item, true, |fcx| { |
| vec![fcx.non_enum_variant(struct_def)] |
| }); |
| |
| self.check_variances_for_type_defn(item, ast_generics); |
| } |
| hir::ItemEnum(ref enum_def, ref ast_generics) => { |
| self.check_type_defn(item, true, |fcx| { |
| fcx.enum_variants(enum_def) |
| }); |
| |
| self.check_variances_for_type_defn(item, ast_generics); |
| } |
| hir::ItemTrait(..) => { |
| self.check_trait(item); |
| } |
| _ => {} |
| } |
| } |
| |
| fn check_associated_item(&mut self, |
| item_id: ast::NodeId, |
| span: Span, |
| sig_if_method: Option<&hir::MethodSig>) { |
| let code = self.code.clone(); |
| self.for_id(item_id, span).with_fcx(|fcx, this| { |
| let item = fcx.tcx.associated_item(fcx.tcx.hir.local_def_id(item_id)); |
| |
| let (mut implied_bounds, self_ty) = match item.container { |
| ty::TraitContainer(_) => (vec![], fcx.tcx.mk_self_type()), |
| ty::ImplContainer(def_id) => (fcx.impl_implied_bounds(def_id, span), |
| fcx.tcx.type_of(def_id)) |
| }; |
| |
| match item.kind { |
| ty::AssociatedKind::Const => { |
| let ty = fcx.tcx.type_of(item.def_id); |
| let ty = fcx.normalize_associated_types_in(span, &ty); |
| fcx.register_wf_obligation(ty, span, code.clone()); |
| } |
| ty::AssociatedKind::Method => { |
| reject_shadowing_type_parameters(fcx.tcx, item.def_id); |
| let sig = fcx.tcx.fn_sig(item.def_id); |
| let sig = fcx.normalize_associated_types_in(span, &sig); |
| let predicates = fcx.tcx.predicates_of(item.def_id) |
| .instantiate_identity(fcx.tcx); |
| let predicates = fcx.normalize_associated_types_in(span, &predicates); |
| this.check_fn_or_method(fcx, span, sig, &predicates, |
| item.def_id, &mut implied_bounds); |
| let sig_if_method = sig_if_method.expect("bad signature for method"); |
| this.check_method_receiver(fcx, sig_if_method, &item, self_ty); |
| } |
| ty::AssociatedKind::Type => { |
| if item.defaultness.has_value() { |
| let ty = fcx.tcx.type_of(item.def_id); |
| let ty = fcx.normalize_associated_types_in(span, &ty); |
| fcx.register_wf_obligation(ty, span, code.clone()); |
| } |
| } |
| } |
| |
| implied_bounds |
| }) |
| } |
| |
| fn for_item<'tcx>(&self, item: &hir::Item) |
| -> CheckWfFcxBuilder<'a, 'gcx, 'tcx> { |
| self.for_id(item.id, item.span) |
| } |
| |
| fn for_id<'tcx>(&self, id: ast::NodeId, span: Span) |
| -> CheckWfFcxBuilder<'a, 'gcx, 'tcx> { |
| let def_id = self.tcx.hir.local_def_id(id); |
| CheckWfFcxBuilder { |
| inherited: Inherited::build(self.tcx, def_id), |
| code: self.code.clone(), |
| id, |
| span, |
| param_env: self.tcx.param_env(def_id), |
| } |
| } |
| |
| /// In a type definition, we check that to ensure that the types of the fields are well-formed. |
| fn check_type_defn<F>(&mut self, item: &hir::Item, all_sized: bool, mut lookup_fields: F) |
| where F: for<'fcx, 'tcx> FnMut(&FnCtxt<'fcx, 'gcx, 'tcx>) -> Vec<AdtVariant<'tcx>> |
| { |
| self.for_item(item).with_fcx(|fcx, this| { |
| let variants = lookup_fields(fcx); |
| let def_id = fcx.tcx.hir.local_def_id(item.id); |
| let packed = fcx.tcx.adt_def(def_id).repr.packed(); |
| |
| for variant in &variants { |
| // For DST, or when drop needs to copy things around, all |
| // intermediate types must be sized. |
| let needs_drop_copy = || { |
| packed && { |
| let ty = variant.fields.last().unwrap().ty; |
| let ty = fcx.tcx.erase_regions(&ty).lift_to_tcx(this.tcx) |
| .unwrap_or_else(|| { |
| span_bug!(item.span, "inference variables in {:?}", ty) |
| }); |
| ty.needs_drop(this.tcx, this.tcx.param_env(def_id)) |
| } |
| }; |
| let unsized_len = if |
| all_sized || |
| variant.fields.is_empty() || |
| needs_drop_copy() |
| { |
| 0 |
| } else { |
| 1 |
| }; |
| for field in &variant.fields[..variant.fields.len() - unsized_len] { |
| fcx.register_bound( |
| field.ty, |
| fcx.tcx.require_lang_item(lang_items::SizedTraitLangItem), |
| traits::ObligationCause::new(field.span, |
| fcx.body_id, |
| traits::FieldSized(match item.node.adt_kind() { |
| Some(i) => i, |
| None => bug!(), |
| }))); |
| } |
| |
| // All field types must be well-formed. |
| for field in &variant.fields { |
| fcx.register_wf_obligation(field.ty, field.span, this.code.clone()) |
| } |
| } |
| |
| let predicates = fcx.tcx.predicates_of(def_id).instantiate_identity(fcx.tcx); |
| let predicates = fcx.normalize_associated_types_in(item.span, &predicates); |
| this.check_where_clauses(fcx, item.span, &predicates); |
| |
| vec![] // no implied bounds in a struct def'n |
| }); |
| } |
| |
| fn check_trait(&mut self, item: &hir::Item) { |
| let trait_def_id = self.tcx.hir.local_def_id(item.id); |
| self.for_item(item).with_fcx(|fcx, this| { |
| let predicates = fcx.tcx.predicates_of(trait_def_id).instantiate_identity(fcx.tcx); |
| let predicates = fcx.normalize_associated_types_in(item.span, &predicates); |
| this.check_where_clauses(fcx, item.span, &predicates); |
| vec![] |
| }); |
| } |
| |
| fn check_item_fn(&mut self, item: &hir::Item) { |
| self.for_item(item).with_fcx(|fcx, this| { |
| let def_id = fcx.tcx.hir.local_def_id(item.id); |
| let sig = fcx.tcx.fn_sig(def_id); |
| let sig = fcx.normalize_associated_types_in(item.span, &sig); |
| |
| let predicates = fcx.tcx.predicates_of(def_id).instantiate_identity(fcx.tcx); |
| let predicates = fcx.normalize_associated_types_in(item.span, &predicates); |
| |
| let mut implied_bounds = vec![]; |
| this.check_fn_or_method(fcx, item.span, sig, &predicates, |
| def_id, &mut implied_bounds); |
| implied_bounds |
| }) |
| } |
| |
| fn check_item_type(&mut self, |
| item: &hir::Item) |
| { |
| debug!("check_item_type: {:?}", item); |
| |
| self.for_item(item).with_fcx(|fcx, this| { |
| let ty = fcx.tcx.type_of(fcx.tcx.hir.local_def_id(item.id)); |
| let item_ty = fcx.normalize_associated_types_in(item.span, &ty); |
| |
| fcx.register_wf_obligation(item_ty, item.span, this.code.clone()); |
| |
| vec![] // no implied bounds in a const etc |
| }); |
| } |
| |
| fn check_impl(&mut self, |
| item: &hir::Item, |
| ast_self_ty: &hir::Ty, |
| ast_trait_ref: &Option<hir::TraitRef>) |
| { |
| debug!("check_impl: {:?}", item); |
| |
| self.for_item(item).with_fcx(|fcx, this| { |
| let item_def_id = fcx.tcx.hir.local_def_id(item.id); |
| |
| match *ast_trait_ref { |
| Some(ref ast_trait_ref) => { |
| let trait_ref = fcx.tcx.impl_trait_ref(item_def_id).unwrap(); |
| let trait_ref = |
| fcx.normalize_associated_types_in( |
| ast_trait_ref.path.span, &trait_ref); |
| let obligations = |
| ty::wf::trait_obligations(fcx, |
| fcx.param_env, |
| fcx.body_id, |
| &trait_ref, |
| ast_trait_ref.path.span); |
| for obligation in obligations { |
| fcx.register_predicate(obligation); |
| } |
| } |
| None => { |
| let self_ty = fcx.tcx.type_of(item_def_id); |
| let self_ty = fcx.normalize_associated_types_in(item.span, &self_ty); |
| fcx.register_wf_obligation(self_ty, ast_self_ty.span, this.code.clone()); |
| } |
| } |
| |
| let predicates = fcx.tcx.predicates_of(item_def_id).instantiate_identity(fcx.tcx); |
| let predicates = fcx.normalize_associated_types_in(item.span, &predicates); |
| this.check_where_clauses(fcx, item.span, &predicates); |
| |
| fcx.impl_implied_bounds(item_def_id, item.span) |
| }); |
| } |
| |
| fn check_where_clauses<'fcx, 'tcx>(&mut self, |
| fcx: &FnCtxt<'fcx, 'gcx, 'tcx>, |
| span: Span, |
| predicates: &ty::InstantiatedPredicates<'tcx>) |
| { |
| let obligations = |
| predicates.predicates |
| .iter() |
| .flat_map(|p| ty::wf::predicate_obligations(fcx, |
| fcx.param_env, |
| fcx.body_id, |
| p, |
| span)); |
| |
| for obligation in obligations { |
| fcx.register_predicate(obligation); |
| } |
| } |
| |
| fn check_fn_or_method<'fcx, 'tcx>(&mut self, |
| fcx: &FnCtxt<'fcx, 'gcx, 'tcx>, |
| span: Span, |
| sig: ty::PolyFnSig<'tcx>, |
| predicates: &ty::InstantiatedPredicates<'tcx>, |
| def_id: DefId, |
| implied_bounds: &mut Vec<Ty<'tcx>>) |
| { |
| let sig = fcx.normalize_associated_types_in(span, &sig); |
| let sig = fcx.tcx.liberate_late_bound_regions(def_id, &sig); |
| |
| for input_ty in sig.inputs() { |
| fcx.register_wf_obligation(&input_ty, span, self.code.clone()); |
| } |
| implied_bounds.extend(sig.inputs()); |
| |
| fcx.register_wf_obligation(sig.output(), span, self.code.clone()); |
| |
| // FIXME(#25759) return types should not be implied bounds |
| implied_bounds.push(sig.output()); |
| |
| self.check_where_clauses(fcx, span, predicates); |
| } |
| |
| fn check_method_receiver<'fcx, 'tcx>(&mut self, |
| fcx: &FnCtxt<'fcx, 'gcx, 'tcx>, |
| method_sig: &hir::MethodSig, |
| method: &ty::AssociatedItem, |
| self_ty: Ty<'tcx>) |
| { |
| // check that the method has a valid receiver type, given the type `Self` |
| debug!("check_method_receiver({:?}, self_ty={:?})", |
| method, self_ty); |
| |
| if !method.method_has_self_argument { |
| return; |
| } |
| |
| let span = method_sig.decl.inputs[0].span; |
| |
| let sig = fcx.tcx.fn_sig(method.def_id); |
| let sig = fcx.normalize_associated_types_in(span, &sig); |
| let sig = fcx.tcx.liberate_late_bound_regions(method.def_id, &sig); |
| |
| debug!("check_method_receiver: sig={:?}", sig); |
| |
| let self_ty = fcx.normalize_associated_types_in(span, &self_ty); |
| let self_ty = fcx.tcx.liberate_late_bound_regions( |
| method.def_id, |
| &ty::Binder(self_ty) |
| ); |
| |
| let self_arg_ty = sig.inputs()[0]; |
| |
| let cause = fcx.cause(span, ObligationCauseCode::MethodReceiver); |
| let self_arg_ty = fcx.normalize_associated_types_in(span, &self_arg_ty); |
| let self_arg_ty = fcx.tcx.liberate_late_bound_regions( |
| method.def_id, |
| &ty::Binder(self_arg_ty) |
| ); |
| |
| let mut autoderef = fcx.autoderef(span, self_arg_ty).include_raw_pointers(); |
| |
| loop { |
| if let Some((potential_self_ty, _)) = autoderef.next() { |
| debug!("check_method_receiver: potential self type `{:?}` to match `{:?}`", |
| potential_self_ty, self_ty); |
| |
| if fcx.infcx.can_eq(fcx.param_env, self_ty, potential_self_ty).is_ok() { |
| autoderef.finalize(); |
| if let Some(mut err) = fcx.demand_eqtype_with_origin( |
| &cause, self_ty, potential_self_ty) { |
| err.emit(); |
| } |
| break |
| } |
| } else { |
| fcx.tcx.sess.diagnostic().mut_span_err( |
| span, &format!("invalid `self` type: {:?}", self_arg_ty)) |
| .note(&format!("type must be `{:?}` or a type that dereferences to it`", self_ty)) |
| .help("consider changing to `self`, `&self`, `&mut self`, or `self: Box<Self>`") |
| .code(DiagnosticId::Error("E0307".into())) |
| .emit(); |
| return |
| } |
| } |
| |
| let is_self_ty = |ty| fcx.infcx.can_eq(fcx.param_env, self_ty, ty).is_ok(); |
| let self_kind = ExplicitSelf::determine(self_arg_ty, is_self_ty); |
| |
| if !fcx.tcx.sess.features.borrow().arbitrary_self_types { |
| match self_kind { |
| ExplicitSelf::ByValue | |
| ExplicitSelf::ByReference(_, _) | |
| ExplicitSelf::ByBox => (), |
| |
| ExplicitSelf::ByRawPointer(_) => { |
| feature_gate::feature_err( |
| &fcx.tcx.sess.parse_sess, |
| "arbitrary_self_types", |
| span, |
| GateIssue::Language, |
| "raw pointer `self` is unstable") |
| .help("consider changing to `self`, `&self`, `&mut self`, or `self: Box<Self>`") |
| .emit(); |
| } |
| |
| ExplicitSelf::Other => { |
| feature_gate::feature_err( |
| &fcx.tcx.sess.parse_sess, |
| "arbitrary_self_types", |
| span, |
| GateIssue::Language,"arbitrary `self` types are unstable") |
| .help("consider changing to `self`, `&self`, `&mut self`, or `self: Box<Self>`") |
| .emit(); |
| } |
| } |
| } |
| } |
| |
| fn check_variances_for_type_defn(&self, |
| item: &hir::Item, |
| ast_generics: &hir::Generics) |
| { |
| let item_def_id = self.tcx.hir.local_def_id(item.id); |
| let ty = self.tcx.type_of(item_def_id); |
| if self.tcx.has_error_field(ty) { |
| return; |
| } |
| |
| let ty_predicates = self.tcx.predicates_of(item_def_id); |
| assert_eq!(ty_predicates.parent, None); |
| let variances = self.tcx.variances_of(item_def_id); |
| |
| let mut constrained_parameters: FxHashSet<_> = |
| variances.iter().enumerate() |
| .filter(|&(_, &variance)| variance != ty::Bivariant) |
| .map(|(index, _)| Parameter(index as u32)) |
| .collect(); |
| |
| identify_constrained_type_params(self.tcx, |
| ty_predicates.predicates.as_slice(), |
| None, |
| &mut constrained_parameters); |
| |
| for (index, _) in variances.iter().enumerate() { |
| if constrained_parameters.contains(&Parameter(index as u32)) { |
| continue; |
| } |
| |
| let (span, name) = match ast_generics.params[index] { |
| hir::GenericParam::Lifetime(ref ld) => (ld.lifetime.span, ld.lifetime.name.name()), |
| hir::GenericParam::Type(ref tp) => (tp.span, tp.name), |
| }; |
| self.report_bivariance(span, name); |
| } |
| } |
| |
| fn report_bivariance(&self, |
| span: Span, |
| param_name: ast::Name) |
| { |
| let mut err = error_392(self.tcx, span, param_name); |
| |
| let suggested_marker_id = self.tcx.lang_items().phantom_data(); |
| match suggested_marker_id { |
| Some(def_id) => { |
| err.help( |
| &format!("consider removing `{}` or using a marker such as `{}`", |
| param_name, |
| self.tcx.item_path_str(def_id))); |
| } |
| None => { |
| // no lang items, no help! |
| } |
| } |
| err.emit(); |
| } |
| } |
| |
| fn reject_shadowing_type_parameters(tcx: TyCtxt, def_id: DefId) { |
| let generics = tcx.generics_of(def_id); |
| let parent = tcx.generics_of(generics.parent.unwrap()); |
| let impl_params: FxHashMap<_, _> = parent.types |
| .iter() |
| .map(|tp| (tp.name, tp.def_id)) |
| .collect(); |
| |
| for method_param in &generics.types { |
| if impl_params.contains_key(&method_param.name) { |
| // Tighten up the span to focus on only the shadowing type |
| let type_span = tcx.def_span(method_param.def_id); |
| |
| // The expectation here is that the original trait declaration is |
| // local so it should be okay to just unwrap everything. |
| let trait_def_id = impl_params[&method_param.name]; |
| let trait_decl_span = tcx.def_span(trait_def_id); |
| error_194(tcx, type_span, trait_decl_span, method_param.name); |
| } |
| } |
| } |
| |
| impl<'a, 'tcx, 'v> Visitor<'v> for CheckTypeWellFormedVisitor<'a, 'tcx> { |
| fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'v> { |
| NestedVisitorMap::None |
| } |
| |
| fn visit_item(&mut self, i: &hir::Item) { |
| debug!("visit_item: {:?}", i); |
| self.check_item_well_formed(i); |
| intravisit::walk_item(self, i); |
| } |
| |
| fn visit_trait_item(&mut self, trait_item: &'v hir::TraitItem) { |
| debug!("visit_trait_item: {:?}", trait_item); |
| let method_sig = match trait_item.node { |
| hir::TraitItemKind::Method(ref sig, _) => Some(sig), |
| _ => None |
| }; |
| self.check_associated_item(trait_item.id, trait_item.span, method_sig); |
| intravisit::walk_trait_item(self, trait_item) |
| } |
| |
| fn visit_impl_item(&mut self, impl_item: &'v hir::ImplItem) { |
| debug!("visit_impl_item: {:?}", impl_item); |
| let method_sig = match impl_item.node { |
| hir::ImplItemKind::Method(ref sig, _) => Some(sig), |
| _ => None |
| }; |
| self.check_associated_item(impl_item.id, impl_item.span, method_sig); |
| intravisit::walk_impl_item(self, impl_item) |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // ADT |
| |
| struct AdtVariant<'tcx> { |
| fields: Vec<AdtField<'tcx>>, |
| } |
| |
| struct AdtField<'tcx> { |
| ty: Ty<'tcx>, |
| span: Span, |
| } |
| |
| impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> { |
| fn non_enum_variant(&self, struct_def: &hir::VariantData) -> AdtVariant<'tcx> { |
| let fields = |
| struct_def.fields().iter() |
| .map(|field| { |
| let field_ty = self.tcx.type_of(self.tcx.hir.local_def_id(field.id)); |
| let field_ty = self.normalize_associated_types_in(field.span, |
| &field_ty); |
| AdtField { ty: field_ty, span: field.span } |
| }) |
| .collect(); |
| AdtVariant { fields: fields } |
| } |
| |
| fn enum_variants(&self, enum_def: &hir::EnumDef) -> Vec<AdtVariant<'tcx>> { |
| enum_def.variants.iter() |
| .map(|variant| self.non_enum_variant(&variant.node.data)) |
| .collect() |
| } |
| |
| fn impl_implied_bounds(&self, impl_def_id: DefId, span: Span) -> Vec<Ty<'tcx>> { |
| match self.tcx.impl_trait_ref(impl_def_id) { |
| Some(ref trait_ref) => { |
| // Trait impl: take implied bounds from all types that |
| // appear in the trait reference. |
| let trait_ref = self.normalize_associated_types_in(span, trait_ref); |
| trait_ref.substs.types().collect() |
| } |
| |
| None => { |
| // Inherent impl: take implied bounds from the self type. |
| let self_ty = self.tcx.type_of(impl_def_id); |
| let self_ty = self.normalize_associated_types_in(span, &self_ty); |
| vec![self_ty] |
| } |
| } |
| } |
| } |
| |
| fn error_392<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, span: Span, param_name: ast::Name) |
| -> DiagnosticBuilder<'tcx> { |
| let mut err = struct_span_err!(tcx.sess, span, E0392, |
| "parameter `{}` is never used", param_name); |
| err.span_label(span, "unused type parameter"); |
| err |
| } |
| |
| fn error_194(tcx: TyCtxt, span: Span, trait_decl_span: Span, name: ast::Name) { |
| struct_span_err!(tcx.sess, span, E0194, |
| "type parameter `{}` shadows another type parameter of the same name", |
| name) |
| .span_label(span, "shadows another type parameter") |
| .span_label(trait_decl_span, format!("first `{}` declared here", name)) |
| .emit(); |
| } |
