| // Copyright 2012-2014 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. |
| |
| //! "Collection" is the process of determining the type and other external |
| //! details of each item in Rust. Collection is specifically concerned |
| //! with *interprocedural* things -- for example, for a function |
| //! definition, collection will figure out the type and signature of the |
| //! function, but it will not visit the *body* of the function in any way, |
| //! nor examine type annotations on local variables (that's the job of |
| //! type *checking*). |
| //! |
| //! Collecting is ultimately defined by a bundle of queries that |
| //! inquire after various facts about the items in the crate (e.g., |
| //! `type_of`, `generics_of`, `predicates_of`, etc). See the `provide` function |
| //! for the full set. |
| //! |
| //! At present, however, we do run collection across all items in the |
| //! crate as a kind of pass. This should eventually be factored away. |
| |
| use astconv::{AstConv, Bounds}; |
| use lint; |
| use constrained_type_params as ctp; |
| use middle::lang_items::SizedTraitLangItem; |
| use middle::const_val::ConstVal; |
| use middle::resolve_lifetime as rl; |
| use rustc::traits::Reveal; |
| use rustc::ty::subst::Substs; |
| use rustc::ty::{ToPredicate, ReprOptions}; |
| use rustc::ty::{self, AdtKind, ToPolyTraitRef, Ty, TyCtxt}; |
| use rustc::ty::maps::Providers; |
| use rustc::ty::util::IntTypeExt; |
| use util::nodemap::FxHashMap; |
| |
| use rustc_const_math::ConstInt; |
| |
| use std::collections::BTreeMap; |
| |
| use syntax::{abi, ast}; |
| use syntax::codemap::Spanned; |
| use syntax::symbol::{Symbol, keywords}; |
| use syntax_pos::{Span, DUMMY_SP}; |
| |
| use rustc::hir::{self, map as hir_map}; |
| use rustc::hir::intravisit::{self, Visitor, NestedVisitorMap}; |
| use rustc::hir::def::{Def, CtorKind}; |
| use rustc::hir::def_id::DefId; |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // Main entry point |
| |
| pub fn collect_item_types<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) { |
| let mut visitor = CollectItemTypesVisitor { tcx: tcx }; |
| tcx.hir.krate().visit_all_item_likes(&mut visitor.as_deep_visitor()); |
| } |
| |
| pub fn provide(providers: &mut Providers) { |
| *providers = Providers { |
| type_of, |
| generics_of, |
| predicates_of, |
| super_predicates_of, |
| type_param_predicates, |
| trait_def, |
| adt_def, |
| fn_sig, |
| impl_trait_ref, |
| impl_polarity, |
| is_foreign_item, |
| is_default_impl, |
| ..*providers |
| }; |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| /// Context specific to some particular item. This is what implements |
| /// AstConv. It has information about the predicates that are defined |
| /// on the trait. Unfortunately, this predicate information is |
| /// available in various different forms at various points in the |
| /// process. So we can't just store a pointer to e.g. the AST or the |
| /// parsed ty form, we have to be more flexible. To this end, the |
| /// `ItemCtxt` is parameterized by a `DefId` that it uses to satisfy |
| /// `get_type_parameter_bounds` requests, drawing the information from |
| /// the AST (`hir::Generics`), recursively. |
| pub struct ItemCtxt<'a,'tcx:'a> { |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| item_def_id: DefId, |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| |
| struct CollectItemTypesVisitor<'a, 'tcx: 'a> { |
| tcx: TyCtxt<'a, 'tcx, 'tcx> |
| } |
| |
| impl<'a, 'tcx> Visitor<'tcx> for CollectItemTypesVisitor<'a, 'tcx> { |
| fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> { |
| NestedVisitorMap::OnlyBodies(&self.tcx.hir) |
| } |
| |
| fn visit_item(&mut self, item: &'tcx hir::Item) { |
| convert_item(self.tcx, item.id); |
| intravisit::walk_item(self, item); |
| } |
| |
| fn visit_generics(&mut self, generics: &'tcx hir::Generics) { |
| for param in &generics.ty_params { |
| if param.default.is_some() { |
| let def_id = self.tcx.hir.local_def_id(param.id); |
| self.tcx.type_of(def_id); |
| } |
| } |
| intravisit::walk_generics(self, generics); |
| } |
| |
| fn visit_expr(&mut self, expr: &'tcx hir::Expr) { |
| if let hir::ExprClosure(..) = expr.node { |
| let def_id = self.tcx.hir.local_def_id(expr.id); |
| self.tcx.generics_of(def_id); |
| self.tcx.type_of(def_id); |
| } |
| intravisit::walk_expr(self, expr); |
| } |
| |
| fn visit_ty(&mut self, ty: &'tcx hir::Ty) { |
| if let hir::TyImplTrait(..) = ty.node { |
| let def_id = self.tcx.hir.local_def_id(ty.id); |
| self.tcx.generics_of(def_id); |
| self.tcx.predicates_of(def_id); |
| } |
| intravisit::walk_ty(self, ty); |
| } |
| |
| fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem) { |
| convert_trait_item(self.tcx, trait_item.id); |
| intravisit::walk_trait_item(self, trait_item); |
| } |
| |
| fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem) { |
| convert_impl_item(self.tcx, impl_item.id); |
| intravisit::walk_impl_item(self, impl_item); |
| } |
| } |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // Utility types and common code for the above passes. |
| |
| impl<'a, 'tcx> ItemCtxt<'a, 'tcx> { |
| pub fn new(tcx: TyCtxt<'a, 'tcx, 'tcx>, item_def_id: DefId) |
| -> ItemCtxt<'a,'tcx> { |
| ItemCtxt { |
| tcx, |
| item_def_id, |
| } |
| } |
| } |
| |
| impl<'a,'tcx> ItemCtxt<'a,'tcx> { |
| pub fn to_ty(&self, ast_ty: &hir::Ty) -> Ty<'tcx> { |
| AstConv::ast_ty_to_ty(self, ast_ty) |
| } |
| } |
| |
| impl<'a, 'tcx> AstConv<'tcx, 'tcx> for ItemCtxt<'a, 'tcx> { |
| fn tcx<'b>(&'b self) -> TyCtxt<'b, 'tcx, 'tcx> { self.tcx } |
| |
| fn get_type_parameter_bounds(&self, |
| span: Span, |
| def_id: DefId) |
| -> ty::GenericPredicates<'tcx> |
| { |
| self.tcx.at(span).type_param_predicates((self.item_def_id, def_id)) |
| } |
| |
| fn re_infer(&self, _span: Span, _def: Option<&ty::RegionParameterDef>) |
| -> Option<ty::Region<'tcx>> { |
| None |
| } |
| |
| fn ty_infer(&self, span: Span) -> Ty<'tcx> { |
| struct_span_err!( |
| self.tcx().sess, |
| span, |
| E0121, |
| "the type placeholder `_` is not allowed within types on item signatures" |
| ).span_label(span, "not allowed in type signatures") |
| .emit(); |
| self.tcx().types.err |
| } |
| |
| fn projected_ty_from_poly_trait_ref(&self, |
| span: Span, |
| item_def_id: DefId, |
| poly_trait_ref: ty::PolyTraitRef<'tcx>) |
| -> Ty<'tcx> |
| { |
| if let Some(trait_ref) = self.tcx().no_late_bound_regions(&poly_trait_ref) { |
| self.tcx().mk_projection(item_def_id, trait_ref.substs) |
| } else { |
| // no late-bound regions, we can just ignore the binder |
| span_err!(self.tcx().sess, span, E0212, |
| "cannot extract an associated type from a higher-ranked trait bound \ |
| in this context"); |
| self.tcx().types.err |
| } |
| } |
| |
| fn normalize_ty(&self, _span: Span, ty: Ty<'tcx>) -> Ty<'tcx> { |
| // types in item signatures are not normalized, to avoid undue |
| // dependencies. |
| ty |
| } |
| |
| fn set_tainted_by_errors(&self) { |
| // no obvious place to track this, just let it go |
| } |
| |
| fn record_ty(&self, _hir_id: hir::HirId, _ty: Ty<'tcx>, _span: Span) { |
| // no place to record types from signatures? |
| } |
| } |
| |
| fn type_param_predicates<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| (item_def_id, def_id): (DefId, DefId)) |
| -> ty::GenericPredicates<'tcx> { |
| use rustc::hir::map::*; |
| use rustc::hir::*; |
| |
| // In the AST, bounds can derive from two places. Either |
| // written inline like `<T:Foo>` or in a where clause like |
| // `where T:Foo`. |
| |
| let param_id = tcx.hir.as_local_node_id(def_id).unwrap(); |
| let param_owner = tcx.hir.ty_param_owner(param_id); |
| let param_owner_def_id = tcx.hir.local_def_id(param_owner); |
| let generics = tcx.generics_of(param_owner_def_id); |
| let index = generics.type_param_to_index[&def_id.index]; |
| let ty = tcx.mk_param(index, tcx.hir.ty_param_name(param_id)); |
| |
| // Don't look for bounds where the type parameter isn't in scope. |
| let parent = if item_def_id == param_owner_def_id { |
| None |
| } else { |
| tcx.generics_of(item_def_id).parent |
| }; |
| |
| let mut result = parent.map_or(ty::GenericPredicates { |
| parent: None, |
| predicates: vec![] |
| }, |parent| { |
| let icx = ItemCtxt::new(tcx, parent); |
| icx.get_type_parameter_bounds(DUMMY_SP, def_id) |
| }); |
| |
| let item_node_id = tcx.hir.as_local_node_id(item_def_id).unwrap(); |
| let ast_generics = match tcx.hir.get(item_node_id) { |
| NodeTraitItem(item) => { |
| match item.node { |
| TraitItemKind::Method(ref sig, _) => &sig.generics, |
| _ => return result |
| } |
| } |
| |
| NodeImplItem(item) => { |
| match item.node { |
| ImplItemKind::Method(ref sig, _) => &sig.generics, |
| _ => return result |
| } |
| } |
| |
| NodeItem(item) => { |
| match item.node { |
| ItemFn(.., ref generics, _) | |
| ItemImpl(_, _, _, ref generics, ..) | |
| ItemTy(_, ref generics) | |
| ItemEnum(_, ref generics) | |
| ItemStruct(_, ref generics) | |
| ItemUnion(_, ref generics) => generics, |
| ItemTrait(_, ref generics, ..) => { |
| // Implied `Self: Trait` and supertrait bounds. |
| if param_id == item_node_id { |
| result.predicates.push(ty::TraitRef { |
| def_id: item_def_id, |
| substs: Substs::identity_for_item(tcx, item_def_id) |
| }.to_predicate()); |
| } |
| generics |
| } |
| _ => return result |
| } |
| } |
| |
| NodeForeignItem(item) => { |
| match item.node { |
| ForeignItemFn(_, _, ref generics) => generics, |
| _ => return result |
| } |
| } |
| |
| _ => return result |
| }; |
| |
| let icx = ItemCtxt::new(tcx, item_def_id); |
| result.predicates.extend( |
| icx.type_parameter_bounds_in_generics(ast_generics, param_id, ty)); |
| result |
| } |
| |
| impl<'a, 'tcx> ItemCtxt<'a, 'tcx> { |
| /// Find bounds from hir::Generics. This requires scanning through the |
| /// AST. We do this to avoid having to convert *all* the bounds, which |
| /// would create artificial cycles. Instead we can only convert the |
| /// bounds for a type parameter `X` if `X::Foo` is used. |
| fn type_parameter_bounds_in_generics(&self, |
| ast_generics: &hir::Generics, |
| param_id: ast::NodeId, |
| ty: Ty<'tcx>) |
| -> Vec<ty::Predicate<'tcx>> |
| { |
| let from_ty_params = |
| ast_generics.ty_params |
| .iter() |
| .filter(|p| p.id == param_id) |
| .flat_map(|p| p.bounds.iter()) |
| .flat_map(|b| predicates_from_bound(self, ty, b)); |
| |
| let from_where_clauses = |
| ast_generics.where_clause |
| .predicates |
| .iter() |
| .filter_map(|wp| match *wp { |
| hir::WherePredicate::BoundPredicate(ref bp) => Some(bp), |
| _ => None |
| }) |
| .filter(|bp| is_param(self.tcx, &bp.bounded_ty, param_id)) |
| .flat_map(|bp| bp.bounds.iter()) |
| .flat_map(|b| predicates_from_bound(self, ty, b)); |
| |
| from_ty_params.chain(from_where_clauses).collect() |
| } |
| } |
| |
| /// Tests whether this is the AST for a reference to the type |
| /// parameter with id `param_id`. We use this so as to avoid running |
| /// `ast_ty_to_ty`, because we want to avoid triggering an all-out |
| /// conversion of the type to avoid inducing unnecessary cycles. |
| fn is_param<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| ast_ty: &hir::Ty, |
| param_id: ast::NodeId) |
| -> bool |
| { |
| if let hir::TyPath(hir::QPath::Resolved(None, ref path)) = ast_ty.node { |
| match path.def { |
| Def::SelfTy(Some(def_id), None) | |
| Def::TyParam(def_id) => { |
| def_id == tcx.hir.local_def_id(param_id) |
| } |
| _ => false |
| } |
| } else { |
| false |
| } |
| } |
| |
| fn ensure_no_ty_param_bounds(tcx: TyCtxt, |
| span: Span, |
| generics: &hir::Generics, |
| thing: &'static str) { |
| let mut warn = false; |
| |
| for ty_param in generics.ty_params.iter() { |
| for bound in ty_param.bounds.iter() { |
| match *bound { |
| hir::TraitTyParamBound(..) => { |
| warn = true; |
| } |
| hir::RegionTyParamBound(..) => { } |
| } |
| } |
| } |
| |
| for predicate in generics.where_clause.predicates.iter() { |
| match *predicate { |
| hir::WherePredicate::BoundPredicate(..) => { |
| warn = true; |
| } |
| hir::WherePredicate::RegionPredicate(..) => { } |
| hir::WherePredicate::EqPredicate(..) => { } |
| } |
| } |
| |
| if warn { |
| // According to accepted RFC #XXX, we should |
| // eventually accept these, but it will not be |
| // part of this PR. Still, convert to warning to |
| // make bootstrapping easier. |
| span_warn!(tcx.sess, span, E0122, |
| "trait bounds are not (yet) enforced \ |
| in {} definitions", |
| thing); |
| } |
| } |
| |
| fn convert_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, item_id: ast::NodeId) { |
| let it = tcx.hir.expect_item(item_id); |
| debug!("convert: item {} with id {}", it.name, it.id); |
| let def_id = tcx.hir.local_def_id(item_id); |
| match it.node { |
| // These don't define types. |
| hir::ItemExternCrate(_) | |
| hir::ItemUse(..) | |
| hir::ItemMod(_) | |
| hir::ItemGlobalAsm(_) => {} |
| hir::ItemForeignMod(ref foreign_mod) => { |
| for item in &foreign_mod.items { |
| let def_id = tcx.hir.local_def_id(item.id); |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.predicates_of(def_id); |
| if let hir::ForeignItemFn(..) = item.node { |
| tcx.fn_sig(def_id); |
| } |
| } |
| } |
| hir::ItemEnum(ref enum_definition, _) => { |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.predicates_of(def_id); |
| convert_enum_variant_types(tcx, def_id, &enum_definition.variants); |
| }, |
| hir::ItemDefaultImpl(..) => { |
| tcx.impl_trait_ref(def_id); |
| } |
| hir::ItemImpl(..) => { |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.impl_trait_ref(def_id); |
| tcx.predicates_of(def_id); |
| }, |
| hir::ItemTrait(..) => { |
| tcx.generics_of(def_id); |
| tcx.trait_def(def_id); |
| tcx.at(it.span).super_predicates_of(def_id); |
| tcx.predicates_of(def_id); |
| }, |
| hir::ItemStruct(ref struct_def, _) | |
| hir::ItemUnion(ref struct_def, _) => { |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.predicates_of(def_id); |
| |
| for f in struct_def.fields() { |
| let def_id = tcx.hir.local_def_id(f.id); |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.predicates_of(def_id); |
| } |
| |
| if !struct_def.is_struct() { |
| convert_variant_ctor(tcx, struct_def.id()); |
| } |
| }, |
| hir::ItemTy(_, ref generics) => { |
| ensure_no_ty_param_bounds(tcx, it.span, generics, "type"); |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.predicates_of(def_id); |
| } |
| hir::ItemStatic(..) | hir::ItemConst(..) | hir::ItemFn(..) => { |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.predicates_of(def_id); |
| if let hir::ItemFn(..) = it.node { |
| tcx.fn_sig(def_id); |
| } |
| } |
| } |
| } |
| |
| fn convert_trait_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, trait_item_id: ast::NodeId) { |
| let trait_item = tcx.hir.expect_trait_item(trait_item_id); |
| let def_id = tcx.hir.local_def_id(trait_item.id); |
| tcx.generics_of(def_id); |
| |
| match trait_item.node { |
| hir::TraitItemKind::Const(..) | |
| hir::TraitItemKind::Type(_, Some(_)) | |
| hir::TraitItemKind::Method(..) => { |
| tcx.type_of(def_id); |
| if let hir::TraitItemKind::Method(..) = trait_item.node { |
| tcx.fn_sig(def_id); |
| } |
| } |
| |
| hir::TraitItemKind::Type(_, None) => {} |
| }; |
| |
| tcx.predicates_of(def_id); |
| } |
| |
| fn convert_impl_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, impl_item_id: ast::NodeId) { |
| let def_id = tcx.hir.local_def_id(impl_item_id); |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.predicates_of(def_id); |
| if let hir::ImplItemKind::Method(..) = tcx.hir.expect_impl_item(impl_item_id).node { |
| tcx.fn_sig(def_id); |
| } |
| } |
| |
| fn convert_variant_ctor<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| ctor_id: ast::NodeId) { |
| let def_id = tcx.hir.local_def_id(ctor_id); |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.predicates_of(def_id); |
| } |
| |
| fn convert_enum_variant_types<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId, |
| variants: &[hir::Variant]) { |
| let param_env = ty::ParamEnv::empty(Reveal::UserFacing); |
| let def = tcx.adt_def(def_id); |
| let repr_type = def.repr.discr_type(); |
| let initial = repr_type.initial_discriminant(tcx); |
| let mut prev_discr = None::<ConstInt>; |
| |
| // fill the discriminant values and field types |
| for variant in variants { |
| let wrapped_discr = prev_discr.map_or(initial, |d| d.wrap_incr()); |
| prev_discr = Some(if let Some(e) = variant.node.disr_expr { |
| let expr_did = tcx.hir.local_def_id(e.node_id); |
| let substs = Substs::identity_for_item(tcx, expr_did); |
| let result = tcx.at(variant.span).const_eval(param_env.and((expr_did, substs))); |
| |
| // enum variant evaluation happens before the global constant check |
| // so we need to report the real error |
| if let Err(ref err) = result { |
| err.report(tcx, variant.span, "enum discriminant"); |
| } |
| |
| match result { |
| Ok(&ty::Const { val: ConstVal::Integral(x), .. }) => Some(x), |
| _ => None |
| } |
| } else if let Some(discr) = repr_type.disr_incr(tcx, prev_discr) { |
| Some(discr) |
| } else { |
| struct_span_err!(tcx.sess, variant.span, E0370, |
| "enum discriminant overflowed") |
| .span_label(variant.span, format!("overflowed on value after {}", |
| prev_discr.unwrap())) |
| .note(&format!("explicitly set `{} = {}` if that is desired outcome", |
| variant.node.name, wrapped_discr)) |
| .emit(); |
| None |
| }.unwrap_or(wrapped_discr)); |
| |
| for f in variant.node.data.fields() { |
| let def_id = tcx.hir.local_def_id(f.id); |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.predicates_of(def_id); |
| } |
| |
| // Convert the ctor, if any. This also registers the variant as |
| // an item. |
| convert_variant_ctor(tcx, variant.node.data.id()); |
| } |
| } |
| |
| fn convert_struct_variant<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| did: DefId, |
| name: ast::Name, |
| discr: ty::VariantDiscr, |
| def: &hir::VariantData) |
| -> ty::VariantDef { |
| let mut seen_fields: FxHashMap<ast::Name, Span> = FxHashMap(); |
| let node_id = tcx.hir.as_local_node_id(did).unwrap(); |
| let fields = def.fields().iter().map(|f| { |
| let fid = tcx.hir.local_def_id(f.id); |
| let dup_span = seen_fields.get(&f.name).cloned(); |
| if let Some(prev_span) = dup_span { |
| struct_span_err!(tcx.sess, f.span, E0124, |
| "field `{}` is already declared", |
| f.name) |
| .span_label(f.span, "field already declared") |
| .span_label(prev_span, format!("`{}` first declared here", f.name)) |
| .emit(); |
| } else { |
| seen_fields.insert(f.name, f.span); |
| } |
| |
| ty::FieldDef { |
| did: fid, |
| name: f.name, |
| vis: ty::Visibility::from_hir(&f.vis, node_id, tcx) |
| } |
| }).collect(); |
| ty::VariantDef { |
| did, |
| name, |
| discr, |
| fields, |
| ctor_kind: CtorKind::from_hir(def), |
| } |
| } |
| |
| fn adt_def<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId) |
| -> &'tcx ty::AdtDef { |
| use rustc::hir::map::*; |
| use rustc::hir::*; |
| |
| let node_id = tcx.hir.as_local_node_id(def_id).unwrap(); |
| let item = match tcx.hir.get(node_id) { |
| NodeItem(item) => item, |
| _ => bug!() |
| }; |
| |
| let repr = ReprOptions::new(tcx, def_id); |
| let (kind, variants) = match item.node { |
| ItemEnum(ref def, _) => { |
| let mut distance_from_explicit = 0; |
| (AdtKind::Enum, def.variants.iter().map(|v| { |
| let did = tcx.hir.local_def_id(v.node.data.id()); |
| let discr = if let Some(e) = v.node.disr_expr { |
| distance_from_explicit = 0; |
| ty::VariantDiscr::Explicit(tcx.hir.local_def_id(e.node_id)) |
| } else { |
| ty::VariantDiscr::Relative(distance_from_explicit) |
| }; |
| distance_from_explicit += 1; |
| |
| convert_struct_variant(tcx, did, v.node.name, discr, &v.node.data) |
| }).collect()) |
| } |
| ItemStruct(ref def, _) => { |
| // Use separate constructor id for unit/tuple structs and reuse did for braced structs. |
| let ctor_id = if !def.is_struct() { |
| Some(tcx.hir.local_def_id(def.id())) |
| } else { |
| None |
| }; |
| (AdtKind::Struct, vec![ |
| convert_struct_variant(tcx, ctor_id.unwrap_or(def_id), item.name, |
| ty::VariantDiscr::Relative(0), def) |
| ]) |
| } |
| ItemUnion(ref def, _) => { |
| (AdtKind::Union, vec![ |
| convert_struct_variant(tcx, def_id, item.name, |
| ty::VariantDiscr::Relative(0), def) |
| ]) |
| } |
| _ => bug!() |
| }; |
| tcx.alloc_adt_def(def_id, kind, variants, repr) |
| } |
| |
| /// Ensures that the super-predicates of the trait with def-id |
| /// trait_def_id are converted and stored. This also ensures that |
| /// the transitive super-predicates are converted; |
| fn super_predicates_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| trait_def_id: DefId) |
| -> ty::GenericPredicates<'tcx> { |
| debug!("super_predicates(trait_def_id={:?})", trait_def_id); |
| let trait_node_id = tcx.hir.as_local_node_id(trait_def_id).unwrap(); |
| |
| let item = match tcx.hir.get(trait_node_id) { |
| hir_map::NodeItem(item) => item, |
| _ => bug!("trait_node_id {} is not an item", trait_node_id) |
| }; |
| |
| let (generics, bounds) = match item.node { |
| hir::ItemTrait(_, ref generics, ref supertraits, _) => (generics, supertraits), |
| _ => span_bug!(item.span, |
| "super_predicates invoked on non-trait"), |
| }; |
| |
| let icx = ItemCtxt::new(tcx, trait_def_id); |
| |
| // Convert the bounds that follow the colon, e.g. `Bar+Zed` in `trait Foo : Bar+Zed`. |
| let self_param_ty = tcx.mk_self_type(); |
| let superbounds1 = compute_bounds(&icx, |
| self_param_ty, |
| bounds, |
| SizedByDefault::No, |
| item.span); |
| |
| let superbounds1 = superbounds1.predicates(tcx, self_param_ty); |
| |
| // Convert any explicit superbounds in the where clause, |
| // e.g. `trait Foo where Self : Bar`: |
| let superbounds2 = icx.type_parameter_bounds_in_generics(generics, item.id, self_param_ty); |
| |
| // Combine the two lists to form the complete set of superbounds: |
| let superbounds: Vec<_> = superbounds1.into_iter().chain(superbounds2).collect(); |
| |
| // Now require that immediate supertraits are converted, |
| // which will, in turn, reach indirect supertraits. |
| for bound in superbounds.iter().filter_map(|p| p.to_opt_poly_trait_ref()) { |
| tcx.at(item.span).super_predicates_of(bound.def_id()); |
| } |
| |
| ty::GenericPredicates { |
| parent: None, |
| predicates: superbounds |
| } |
| } |
| |
| fn trait_def<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId) |
| -> &'tcx ty::TraitDef { |
| let node_id = tcx.hir.as_local_node_id(def_id).unwrap(); |
| let item = tcx.hir.expect_item(node_id); |
| |
| let unsafety = match item.node { |
| hir::ItemTrait(unsafety, ..) => unsafety, |
| _ => span_bug!(item.span, "trait_def_of_item invoked on non-trait"), |
| }; |
| |
| let paren_sugar = tcx.has_attr(def_id, "rustc_paren_sugar"); |
| if paren_sugar && !tcx.sess.features.borrow().unboxed_closures { |
| let mut err = tcx.sess.struct_span_err( |
| item.span, |
| "the `#[rustc_paren_sugar]` attribute is a temporary means of controlling \ |
| which traits can use parenthetical notation"); |
| help!(&mut err, |
| "add `#![feature(unboxed_closures)]` to \ |
| the crate attributes to use it"); |
| err.emit(); |
| } |
| |
| let def_path_hash = tcx.def_path_hash(def_id); |
| let has_default_impl = tcx.hir.trait_is_auto(def_id); |
| let def = ty::TraitDef::new(def_id, |
| unsafety, |
| paren_sugar, |
| has_default_impl, |
| def_path_hash); |
| tcx.alloc_trait_def(def) |
| } |
| |
| fn has_late_bound_regions<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| node: hir_map::Node<'tcx>) |
| -> Option<Span> { |
| struct LateBoundRegionsDetector<'a, 'tcx: 'a> { |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| binder_depth: u32, |
| has_late_bound_regions: Option<Span>, |
| } |
| |
| impl<'a, 'tcx> Visitor<'tcx> for LateBoundRegionsDetector<'a, 'tcx> { |
| fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> { |
| NestedVisitorMap::None |
| } |
| |
| fn visit_ty(&mut self, ty: &'tcx hir::Ty) { |
| if self.has_late_bound_regions.is_some() { return } |
| match ty.node { |
| hir::TyBareFn(..) => { |
| self.binder_depth += 1; |
| intravisit::walk_ty(self, ty); |
| self.binder_depth -= 1; |
| } |
| _ => intravisit::walk_ty(self, ty) |
| } |
| } |
| |
| fn visit_poly_trait_ref(&mut self, |
| tr: &'tcx hir::PolyTraitRef, |
| m: hir::TraitBoundModifier) { |
| if self.has_late_bound_regions.is_some() { return } |
| self.binder_depth += 1; |
| intravisit::walk_poly_trait_ref(self, tr, m); |
| self.binder_depth -= 1; |
| } |
| |
| fn visit_lifetime(&mut self, lt: &'tcx hir::Lifetime) { |
| if self.has_late_bound_regions.is_some() { return } |
| |
| let hir_id = self.tcx.hir.node_to_hir_id(lt.id); |
| match self.tcx.named_region(hir_id) { |
| Some(rl::Region::Static) | Some(rl::Region::EarlyBound(..)) => {} |
| Some(rl::Region::LateBound(debruijn, _)) | |
| Some(rl::Region::LateBoundAnon(debruijn, _)) |
| if debruijn.depth < self.binder_depth => {} |
| _ => self.has_late_bound_regions = Some(lt.span), |
| } |
| } |
| } |
| |
| fn has_late_bound_regions<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| generics: &'tcx hir::Generics, |
| decl: &'tcx hir::FnDecl) |
| -> Option<Span> { |
| let mut visitor = LateBoundRegionsDetector { |
| tcx, binder_depth: 1, has_late_bound_regions: None |
| }; |
| for lifetime in &generics.lifetimes { |
| let hir_id = tcx.hir.node_to_hir_id(lifetime.lifetime.id); |
| if tcx.is_late_bound(hir_id) { |
| return Some(lifetime.lifetime.span); |
| } |
| } |
| visitor.visit_fn_decl(decl); |
| visitor.has_late_bound_regions |
| } |
| |
| match node { |
| hir_map::NodeTraitItem(item) => match item.node { |
| hir::TraitItemKind::Method(ref sig, _) => |
| has_late_bound_regions(tcx, &sig.generics, &sig.decl), |
| _ => None, |
| }, |
| hir_map::NodeImplItem(item) => match item.node { |
| hir::ImplItemKind::Method(ref sig, _) => |
| has_late_bound_regions(tcx, &sig.generics, &sig.decl), |
| _ => None, |
| }, |
| hir_map::NodeForeignItem(item) => match item.node { |
| hir::ForeignItemFn(ref fn_decl, _, ref generics) => |
| has_late_bound_regions(tcx, generics, fn_decl), |
| _ => None, |
| }, |
| hir_map::NodeItem(item) => match item.node { |
| hir::ItemFn(ref fn_decl, .., ref generics, _) => |
| has_late_bound_regions(tcx, generics, fn_decl), |
| _ => None, |
| }, |
| _ => None |
| } |
| } |
| |
| fn generics_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId) |
| -> &'tcx ty::Generics { |
| use rustc::hir::map::*; |
| use rustc::hir::*; |
| |
| let node_id = tcx.hir.as_local_node_id(def_id).unwrap(); |
| |
| let node = tcx.hir.get(node_id); |
| let parent_def_id = match node { |
| NodeImplItem(_) | |
| NodeTraitItem(_) | |
| NodeVariant(_) | |
| NodeStructCtor(_) | |
| NodeField(_) => { |
| let parent_id = tcx.hir.get_parent(node_id); |
| Some(tcx.hir.local_def_id(parent_id)) |
| } |
| NodeExpr(&hir::Expr { node: hir::ExprClosure(..), .. }) => { |
| Some(tcx.closure_base_def_id(def_id)) |
| } |
| NodeTy(&hir::Ty { node: hir::TyImplTrait(..), .. }) => { |
| let mut parent_id = node_id; |
| loop { |
| match tcx.hir.get(parent_id) { |
| NodeItem(_) | NodeImplItem(_) | NodeTraitItem(_) => break, |
| _ => { |
| parent_id = tcx.hir.get_parent_node(parent_id); |
| } |
| } |
| } |
| Some(tcx.hir.local_def_id(parent_id)) |
| } |
| _ => None |
| }; |
| |
| let mut opt_self = None; |
| let mut allow_defaults = false; |
| |
| let no_generics = hir::Generics::empty(); |
| let ast_generics = match node { |
| NodeTraitItem(item) => { |
| match item.node { |
| TraitItemKind::Method(ref sig, _) => &sig.generics, |
| _ => &no_generics |
| } |
| } |
| |
| NodeImplItem(item) => { |
| match item.node { |
| ImplItemKind::Method(ref sig, _) => &sig.generics, |
| _ => &no_generics |
| } |
| } |
| |
| NodeItem(item) => { |
| match item.node { |
| ItemFn(.., ref generics, _) | |
| ItemImpl(_, _, _, ref generics, ..) => generics, |
| |
| ItemTy(_, ref generics) | |
| ItemEnum(_, ref generics) | |
| ItemStruct(_, ref generics) | |
| ItemUnion(_, ref generics) => { |
| allow_defaults = true; |
| generics |
| } |
| |
| ItemTrait(_, ref generics, ..) => { |
| // Add in the self type parameter. |
| // |
| // Something of a hack: use the node id for the trait, also as |
| // the node id for the Self type parameter. |
| let param_id = item.id; |
| |
| opt_self = Some(ty::TypeParameterDef { |
| index: 0, |
| name: keywords::SelfType.name(), |
| def_id: tcx.hir.local_def_id(param_id), |
| has_default: false, |
| object_lifetime_default: rl::Set1::Empty, |
| pure_wrt_drop: false, |
| synthetic: None, |
| }); |
| |
| allow_defaults = true; |
| generics |
| } |
| |
| _ => &no_generics |
| } |
| } |
| |
| NodeForeignItem(item) => { |
| match item.node { |
| ForeignItemStatic(..) => &no_generics, |
| ForeignItemFn(_, _, ref generics) => generics |
| } |
| } |
| |
| _ => &no_generics |
| }; |
| |
| let has_self = opt_self.is_some(); |
| let mut parent_has_self = false; |
| let mut own_start = has_self as u32; |
| let (parent_regions, parent_types) = parent_def_id.map_or((0, 0), |def_id| { |
| let generics = tcx.generics_of(def_id); |
| assert_eq!(has_self, false); |
| parent_has_self = generics.has_self; |
| own_start = generics.count() as u32; |
| (generics.parent_regions + generics.regions.len() as u32, |
| generics.parent_types + generics.types.len() as u32) |
| }); |
| |
| let early_lifetimes = early_bound_lifetimes_from_generics(tcx, ast_generics); |
| let regions = early_lifetimes.enumerate().map(|(i, l)| { |
| ty::RegionParameterDef { |
| name: l.lifetime.name.name(), |
| index: own_start + i as u32, |
| def_id: tcx.hir.local_def_id(l.lifetime.id), |
| pure_wrt_drop: l.pure_wrt_drop, |
| } |
| }).collect::<Vec<_>>(); |
| |
| let hir_id = tcx.hir.node_to_hir_id(node_id); |
| let object_lifetime_defaults = tcx.object_lifetime_defaults(hir_id); |
| |
| // Now create the real type parameters. |
| let type_start = own_start + regions.len() as u32; |
| let types = ast_generics.ty_params.iter().enumerate().map(|(i, p)| { |
| if p.name == keywords::SelfType.name() { |
| span_bug!(p.span, "`Self` should not be the name of a regular parameter"); |
| } |
| |
| if !allow_defaults && p.default.is_some() { |
| if !tcx.sess.features.borrow().default_type_parameter_fallback { |
| tcx.lint_node( |
| lint::builtin::INVALID_TYPE_PARAM_DEFAULT, |
| p.id, |
| p.span, |
| &format!("defaults for type parameters are only allowed in `struct`, \ |
| `enum`, `type`, or `trait` definitions.")); |
| } |
| } |
| |
| ty::TypeParameterDef { |
| index: type_start + i as u32, |
| name: p.name, |
| def_id: tcx.hir.local_def_id(p.id), |
| has_default: p.default.is_some(), |
| object_lifetime_default: |
| object_lifetime_defaults.as_ref().map_or(rl::Set1::Empty, |o| o[i]), |
| pure_wrt_drop: p.pure_wrt_drop, |
| synthetic: p.synthetic, |
| } |
| }); |
| let mut types: Vec<_> = opt_self.into_iter().chain(types).collect(); |
| |
| // provide junk type parameter defs - the only place that |
| // cares about anything but the length is instantiation, |
| // and we don't do that for closures. |
| if let NodeExpr(&hir::Expr { node: hir::ExprClosure(..), .. }) = node { |
| tcx.with_freevars(node_id, |fv| { |
| types.extend(fv.iter().enumerate().map(|(i, _)| ty::TypeParameterDef { |
| index: type_start + i as u32, |
| name: Symbol::intern("<upvar>"), |
| def_id, |
| has_default: false, |
| object_lifetime_default: rl::Set1::Empty, |
| pure_wrt_drop: false, |
| synthetic: None, |
| })); |
| }); |
| } |
| |
| let mut type_param_to_index = BTreeMap::new(); |
| for param in &types { |
| type_param_to_index.insert(param.def_id.index, param.index); |
| } |
| |
| tcx.alloc_generics(ty::Generics { |
| parent: parent_def_id, |
| parent_regions, |
| parent_types, |
| regions, |
| types, |
| type_param_to_index, |
| has_self: has_self || parent_has_self, |
| has_late_bound_regions: has_late_bound_regions(tcx, node), |
| }) |
| } |
| |
| fn type_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId) |
| -> Ty<'tcx> { |
| use rustc::hir::map::*; |
| use rustc::hir::*; |
| |
| let node_id = tcx.hir.as_local_node_id(def_id).unwrap(); |
| |
| let icx = ItemCtxt::new(tcx, def_id); |
| |
| match tcx.hir.get(node_id) { |
| NodeTraitItem(item) => { |
| match item.node { |
| TraitItemKind::Method(..) => { |
| let substs = Substs::identity_for_item(tcx, def_id); |
| tcx.mk_fn_def(def_id, substs) |
| } |
| TraitItemKind::Const(ref ty, _) | |
| TraitItemKind::Type(_, Some(ref ty)) => icx.to_ty(ty), |
| TraitItemKind::Type(_, None) => { |
| span_bug!(item.span, "associated type missing default"); |
| } |
| } |
| } |
| |
| NodeImplItem(item) => { |
| match item.node { |
| ImplItemKind::Method(..) => { |
| let substs = Substs::identity_for_item(tcx, def_id); |
| tcx.mk_fn_def(def_id, substs) |
| } |
| ImplItemKind::Const(ref ty, _) => icx.to_ty(ty), |
| ImplItemKind::Type(ref ty) => { |
| if tcx.impl_trait_ref(tcx.hir.get_parent_did(node_id)).is_none() { |
| span_err!(tcx.sess, item.span, E0202, |
| "associated types are not allowed in inherent impls"); |
| } |
| |
| icx.to_ty(ty) |
| } |
| } |
| } |
| |
| NodeItem(item) => { |
| match item.node { |
| ItemStatic(ref t, ..) | ItemConst(ref t, _) | |
| ItemTy(ref t, _) | ItemImpl(.., ref t, _) => { |
| icx.to_ty(t) |
| } |
| ItemFn(..) => { |
| let substs = Substs::identity_for_item(tcx, def_id); |
| tcx.mk_fn_def(def_id, substs) |
| } |
| ItemEnum(..) | |
| ItemStruct(..) | |
| ItemUnion(..) => { |
| let def = tcx.adt_def(def_id); |
| let substs = Substs::identity_for_item(tcx, def_id); |
| tcx.mk_adt(def, substs) |
| } |
| ItemDefaultImpl(..) | |
| ItemTrait(..) | |
| ItemMod(..) | |
| ItemForeignMod(..) | |
| ItemGlobalAsm(..) | |
| ItemExternCrate(..) | |
| ItemUse(..) => { |
| span_bug!( |
| item.span, |
| "compute_type_of_item: unexpected item type: {:?}", |
| item.node); |
| } |
| } |
| } |
| |
| NodeForeignItem(foreign_item) => { |
| match foreign_item.node { |
| ForeignItemFn(..) => { |
| let substs = Substs::identity_for_item(tcx, def_id); |
| tcx.mk_fn_def(def_id, substs) |
| } |
| ForeignItemStatic(ref t, _) => icx.to_ty(t) |
| } |
| } |
| |
| NodeStructCtor(&ref def) | |
| NodeVariant(&Spanned { node: hir::Variant_ { data: ref def, .. }, .. }) => { |
| match *def { |
| VariantData::Unit(..) | VariantData::Struct(..) => { |
| tcx.type_of(tcx.hir.get_parent_did(node_id)) |
| } |
| VariantData::Tuple(..) => { |
| let substs = Substs::identity_for_item(tcx, def_id); |
| tcx.mk_fn_def(def_id, substs) |
| } |
| } |
| } |
| |
| NodeField(field) => icx.to_ty(&field.ty), |
| |
| NodeExpr(&hir::Expr { node: hir::ExprClosure(.., is_generator), .. }) => { |
| if is_generator { |
| let hir_id = tcx.hir.node_to_hir_id(node_id); |
| return tcx.typeck_tables_of(def_id).node_id_to_type(hir_id); |
| } |
| |
| tcx.mk_closure(def_id, Substs::for_item( |
| tcx, def_id, |
| |def, _| { |
| let region = def.to_early_bound_region_data(); |
| tcx.mk_region(ty::ReEarlyBound(region)) |
| }, |
| |def, _| tcx.mk_param_from_def(def) |
| )) |
| } |
| |
| NodeExpr(_) => match tcx.hir.get(tcx.hir.get_parent_node(node_id)) { |
| NodeTy(&hir::Ty { node: TyArray(_, body), .. }) | |
| NodeTy(&hir::Ty { node: TyTypeof(body), .. }) | |
| NodeExpr(&hir::Expr { node: ExprRepeat(_, body), .. }) |
| if body.node_id == node_id => tcx.types.usize, |
| |
| NodeVariant(&Spanned { node: Variant_ { disr_expr: Some(e), .. }, .. }) |
| if e.node_id == node_id => { |
| tcx.adt_def(tcx.hir.get_parent_did(node_id)) |
| .repr.discr_type().to_ty(tcx) |
| } |
| |
| x => { |
| bug!("unexpected expr parent in type_of_def_id(): {:?}", x); |
| } |
| }, |
| |
| NodeTyParam(&hir::TyParam { default: Some(ref ty), .. }) => { |
| icx.to_ty(ty) |
| } |
| |
| NodeTy(&hir::Ty { node: TyImplTrait(..), .. }) => { |
| let owner = tcx.hir.get_parent_did(node_id); |
| let hir_id = tcx.hir.node_to_hir_id(node_id); |
| tcx.typeck_tables_of(owner).node_id_to_type(hir_id) |
| } |
| |
| x => { |
| bug!("unexpected sort of node in type_of_def_id(): {:?}", x); |
| } |
| } |
| } |
| |
| fn fn_sig<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId) |
| -> ty::PolyFnSig<'tcx> { |
| use rustc::hir::map::*; |
| use rustc::hir::*; |
| |
| let node_id = tcx.hir.as_local_node_id(def_id).unwrap(); |
| |
| let icx = ItemCtxt::new(tcx, def_id); |
| |
| match tcx.hir.get(node_id) { |
| NodeTraitItem(&hir::TraitItem { node: TraitItemKind::Method(ref sig, _), .. }) | |
| NodeImplItem(&hir::ImplItem { node: ImplItemKind::Method(ref sig, _), .. }) => { |
| AstConv::ty_of_fn(&icx, sig.unsafety, sig.abi, &sig.decl) |
| } |
| |
| NodeItem(&hir::Item { node: ItemFn(ref decl, unsafety, _, abi, _, _), .. }) => { |
| AstConv::ty_of_fn(&icx, unsafety, abi, decl) |
| } |
| |
| NodeForeignItem(&hir::ForeignItem { node: ForeignItemFn(ref fn_decl, _, _), .. }) => { |
| let abi = tcx.hir.get_foreign_abi(node_id); |
| compute_sig_of_foreign_fn_decl(tcx, def_id, fn_decl, abi) |
| } |
| |
| NodeStructCtor(&VariantData::Tuple(ref fields, _)) | |
| NodeVariant(&Spanned { node: hir::Variant_ { |
| data: VariantData::Tuple(ref fields, _), .. |
| }, .. }) => { |
| let ty = tcx.type_of(tcx.hir.get_parent_did(node_id)); |
| let inputs = fields.iter().map(|f| { |
| tcx.type_of(tcx.hir.local_def_id(f.id)) |
| }); |
| ty::Binder(tcx.mk_fn_sig( |
| inputs, |
| ty, |
| false, |
| hir::Unsafety::Normal, |
| abi::Abi::Rust |
| )) |
| } |
| |
| NodeExpr(&hir::Expr { node: hir::ExprClosure(..), hir_id, .. }) => { |
| tcx.typeck_tables_of(def_id).closure_tys()[hir_id] |
| } |
| |
| x => { |
| bug!("unexpected sort of node in fn_sig(): {:?}", x); |
| } |
| } |
| } |
| |
| fn impl_trait_ref<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId) |
| -> Option<ty::TraitRef<'tcx>> { |
| let icx = ItemCtxt::new(tcx, def_id); |
| |
| let node_id = tcx.hir.as_local_node_id(def_id).unwrap(); |
| match tcx.hir.expect_item(node_id).node { |
| hir::ItemDefaultImpl(_, ref ast_trait_ref) => { |
| Some(AstConv::instantiate_mono_trait_ref(&icx, |
| ast_trait_ref, |
| tcx.mk_self_type())) |
| } |
| hir::ItemImpl(.., ref opt_trait_ref, _, _) => { |
| opt_trait_ref.as_ref().map(|ast_trait_ref| { |
| let selfty = tcx.type_of(def_id); |
| AstConv::instantiate_mono_trait_ref(&icx, ast_trait_ref, selfty) |
| }) |
| } |
| _ => bug!() |
| } |
| } |
| |
| fn impl_polarity<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId) |
| -> hir::ImplPolarity { |
| let node_id = tcx.hir.as_local_node_id(def_id).unwrap(); |
| match tcx.hir.expect_item(node_id).node { |
| hir::ItemImpl(_, polarity, ..) => polarity, |
| ref item => bug!("impl_polarity: {:?} not an impl", item) |
| } |
| } |
| |
| // Is it marked with ?Sized |
| fn is_unsized<'gcx: 'tcx, 'tcx>(astconv: &AstConv<'gcx, 'tcx>, |
| ast_bounds: &[hir::TyParamBound], |
| span: Span) -> bool |
| { |
| let tcx = astconv.tcx(); |
| |
| // Try to find an unbound in bounds. |
| let mut unbound = None; |
| for ab in ast_bounds { |
| if let &hir::TraitTyParamBound(ref ptr, hir::TraitBoundModifier::Maybe) = ab { |
| if unbound.is_none() { |
| unbound = Some(ptr.trait_ref.clone()); |
| } else { |
| span_err!(tcx.sess, span, E0203, |
| "type parameter has more than one relaxed default \ |
| bound, only one is supported"); |
| } |
| } |
| } |
| |
| let kind_id = tcx.lang_items().require(SizedTraitLangItem); |
| match unbound { |
| Some(ref tpb) => { |
| // FIXME(#8559) currently requires the unbound to be built-in. |
| if let Ok(kind_id) = kind_id { |
| if tpb.path.def != Def::Trait(kind_id) { |
| tcx.sess.span_warn(span, |
| "default bound relaxed for a type parameter, but \ |
| this does nothing because the given bound is not \ |
| a default. Only `?Sized` is supported"); |
| } |
| } |
| } |
| _ if kind_id.is_ok() => { |
| return false; |
| } |
| // No lang item for Sized, so we can't add it as a bound. |
| None => {} |
| } |
| |
| true |
| } |
| |
| /// Returns the early-bound lifetimes declared in this generics |
| /// listing. For anything other than fns/methods, this is just all |
| /// the lifetimes that are declared. For fns or methods, we have to |
| /// screen out those that do not appear in any where-clauses etc using |
| /// `resolve_lifetime::early_bound_lifetimes`. |
| fn early_bound_lifetimes_from_generics<'a, 'tcx>( |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| ast_generics: &'a hir::Generics) |
| -> impl Iterator<Item=&'a hir::LifetimeDef> |
| { |
| ast_generics |
| .lifetimes |
| .iter() |
| .filter(move |l| { |
| let hir_id = tcx.hir.node_to_hir_id(l.lifetime.id); |
| !tcx.is_late_bound(hir_id) |
| }) |
| } |
| |
| fn predicates_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId) |
| -> ty::GenericPredicates<'tcx> { |
| let explicit = explicit_predicates_of(tcx, def_id); |
| ty::GenericPredicates { |
| parent: explicit.parent, |
| predicates: [&explicit.predicates[..], &tcx.inferred_outlives_of(def_id)[..]].concat() |
| } |
| } |
| |
| fn explicit_predicates_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId) |
| -> ty::GenericPredicates<'tcx> { |
| use rustc::hir::map::*; |
| use rustc::hir::*; |
| |
| let node_id = tcx.hir.as_local_node_id(def_id).unwrap(); |
| let node = tcx.hir.get(node_id); |
| |
| let mut is_trait = None; |
| |
| let icx = ItemCtxt::new(tcx, def_id); |
| let no_generics = hir::Generics::empty(); |
| let ast_generics = match node { |
| NodeTraitItem(item) => { |
| match item.node { |
| TraitItemKind::Method(ref sig, _) => &sig.generics, |
| _ => &no_generics |
| } |
| } |
| |
| NodeImplItem(item) => { |
| match item.node { |
| ImplItemKind::Method(ref sig, _) => &sig.generics, |
| _ => &no_generics |
| } |
| } |
| |
| NodeItem(item) => { |
| match item.node { |
| ItemFn(.., ref generics, _) | |
| ItemImpl(_, _, _, ref generics, ..) | |
| ItemTy(_, ref generics) | |
| ItemEnum(_, ref generics) | |
| ItemStruct(_, ref generics) | |
| ItemUnion(_, ref generics) => { |
| generics |
| } |
| |
| ItemTrait(_, ref generics, .., ref items) => { |
| is_trait = Some((ty::TraitRef { |
| def_id, |
| substs: Substs::identity_for_item(tcx, def_id) |
| }, items)); |
| generics |
| } |
| |
| _ => &no_generics |
| } |
| } |
| |
| NodeForeignItem(item) => { |
| match item.node { |
| ForeignItemStatic(..) => &no_generics, |
| ForeignItemFn(_, _, ref generics) => generics |
| } |
| } |
| |
| NodeTy(&Ty { node: TyImplTrait(ref bounds), span, .. }) => { |
| let substs = Substs::identity_for_item(tcx, def_id); |
| let anon_ty = tcx.mk_anon(def_id, substs); |
| |
| // Collect the bounds, i.e. the `A+B+'c` in `impl A+B+'c`. |
| let bounds = compute_bounds(&icx, anon_ty, bounds, |
| SizedByDefault::Yes, |
| span); |
| return ty::GenericPredicates { |
| parent: None, |
| predicates: bounds.predicates(tcx, anon_ty) |
| }; |
| } |
| |
| _ => &no_generics |
| }; |
| |
| let generics = tcx.generics_of(def_id); |
| let parent_count = generics.parent_count() as u32; |
| let has_own_self = generics.has_self && parent_count == 0; |
| |
| let mut predicates = vec![]; |
| |
| // Below we'll consider the bounds on the type parameters (including `Self`) |
| // and the explicit where-clauses, but to get the full set of predicates |
| // on a trait we need to add in the supertrait bounds and bounds found on |
| // associated types. |
| if let Some((trait_ref, _)) = is_trait { |
| predicates = tcx.super_predicates_of(def_id).predicates; |
| |
| // Add in a predicate that `Self:Trait` (where `Trait` is the |
| // current trait). This is needed for builtin bounds. |
| predicates.push(trait_ref.to_poly_trait_ref().to_predicate()); |
| } |
| |
| // Collect the region predicates that were declared inline as |
| // well. In the case of parameters declared on a fn or method, we |
| // have to be careful to only iterate over early-bound regions. |
| let mut index = parent_count + has_own_self as u32; |
| for param in early_bound_lifetimes_from_generics(tcx, ast_generics) { |
| let region = tcx.mk_region(ty::ReEarlyBound(ty::EarlyBoundRegion { |
| def_id: tcx.hir.local_def_id(param.lifetime.id), |
| index, |
| name: param.lifetime.name.name(), |
| })); |
| index += 1; |
| |
| for bound in ¶m.bounds { |
| let bound_region = AstConv::ast_region_to_region(&icx, bound, None); |
| let outlives = ty::Binder(ty::OutlivesPredicate(region, bound_region)); |
| predicates.push(outlives.to_predicate()); |
| } |
| } |
| |
| // Collect the predicates that were written inline by the user on each |
| // type parameter (e.g., `<T:Foo>`). |
| for param in &ast_generics.ty_params { |
| let param_ty = ty::ParamTy::new(index, param.name).to_ty(tcx); |
| index += 1; |
| |
| let bounds = compute_bounds(&icx, |
| param_ty, |
| ¶m.bounds, |
| SizedByDefault::Yes, |
| param.span); |
| predicates.extend(bounds.predicates(tcx, param_ty)); |
| } |
| |
| // Add in the bounds that appear in the where-clause |
| let where_clause = &ast_generics.where_clause; |
| for predicate in &where_clause.predicates { |
| match predicate { |
| &hir::WherePredicate::BoundPredicate(ref bound_pred) => { |
| let ty = icx.to_ty(&bound_pred.bounded_ty); |
| |
| for bound in bound_pred.bounds.iter() { |
| match bound { |
| &hir::TyParamBound::TraitTyParamBound(ref poly_trait_ref, _) => { |
| let mut projections = Vec::new(); |
| |
| let trait_ref = |
| AstConv::instantiate_poly_trait_ref(&icx, |
| poly_trait_ref, |
| ty, |
| &mut projections); |
| |
| predicates.push(trait_ref.to_predicate()); |
| |
| for projection in &projections { |
| predicates.push(projection.to_predicate()); |
| } |
| } |
| |
| &hir::TyParamBound::RegionTyParamBound(ref lifetime) => { |
| let region = AstConv::ast_region_to_region(&icx, |
| lifetime, |
| None); |
| let pred = ty::Binder(ty::OutlivesPredicate(ty, region)); |
| predicates.push(ty::Predicate::TypeOutlives(pred)) |
| } |
| } |
| } |
| } |
| |
| &hir::WherePredicate::RegionPredicate(ref region_pred) => { |
| let r1 = AstConv::ast_region_to_region(&icx, ®ion_pred.lifetime, None); |
| for bound in ®ion_pred.bounds { |
| let r2 = AstConv::ast_region_to_region(&icx, bound, None); |
| let pred = ty::Binder(ty::OutlivesPredicate(r1, r2)); |
| predicates.push(ty::Predicate::RegionOutlives(pred)) |
| } |
| } |
| |
| &hir::WherePredicate::EqPredicate(..) => { |
| // FIXME(#20041) |
| } |
| } |
| } |
| |
| // Add predicates from associated type bounds. |
| if let Some((self_trait_ref, trait_items)) = is_trait { |
| predicates.extend(trait_items.iter().flat_map(|trait_item_ref| { |
| let trait_item = tcx.hir.trait_item(trait_item_ref.id); |
| let bounds = match trait_item.node { |
| hir::TraitItemKind::Type(ref bounds, _) => bounds, |
| _ => { |
| return vec![].into_iter(); |
| } |
| }; |
| |
| let assoc_ty = tcx.mk_projection( |
| tcx.hir.local_def_id(trait_item.id), |
| self_trait_ref.substs, |
| ); |
| |
| let bounds = compute_bounds(&ItemCtxt::new(tcx, def_id), |
| assoc_ty, |
| bounds, |
| SizedByDefault::Yes, |
| trait_item.span); |
| |
| bounds.predicates(tcx, assoc_ty).into_iter() |
| })) |
| } |
| |
| // Subtle: before we store the predicates into the tcx, we |
| // sort them so that predicates like `T: Foo<Item=U>` come |
| // before uses of `U`. This avoids false ambiguity errors |
| // in trait checking. See `setup_constraining_predicates` |
| // for details. |
| if let NodeItem(&Item { node: ItemImpl(..), .. }) = node { |
| let self_ty = tcx.type_of(def_id); |
| let trait_ref = tcx.impl_trait_ref(def_id); |
| ctp::setup_constraining_predicates(tcx, |
| &mut predicates, |
| trait_ref, |
| &mut ctp::parameters_for_impl(self_ty, trait_ref)); |
| } |
| |
| ty::GenericPredicates { |
| parent: generics.parent, |
| predicates, |
| } |
| } |
| |
| pub enum SizedByDefault { Yes, No, } |
| |
| /// Translate the AST's notion of ty param bounds (which are an enum consisting of a newtyped Ty or |
| /// a region) to ty's notion of ty param bounds, which can either be user-defined traits, or the |
| /// built-in trait (formerly known as kind): Send. |
| pub fn compute_bounds<'gcx: 'tcx, 'tcx>(astconv: &AstConv<'gcx, 'tcx>, |
| param_ty: Ty<'tcx>, |
| ast_bounds: &[hir::TyParamBound], |
| sized_by_default: SizedByDefault, |
| span: Span) |
| -> Bounds<'tcx> |
| { |
| let mut region_bounds = vec![]; |
| let mut trait_bounds = vec![]; |
| for ast_bound in ast_bounds { |
| match *ast_bound { |
| hir::TraitTyParamBound(ref b, hir::TraitBoundModifier::None) => { |
| trait_bounds.push(b); |
| } |
| hir::TraitTyParamBound(_, hir::TraitBoundModifier::Maybe) => {} |
| hir::RegionTyParamBound(ref l) => { |
| region_bounds.push(l); |
| } |
| } |
| } |
| |
| let mut projection_bounds = vec![]; |
| |
| let mut trait_bounds: Vec<_> = trait_bounds.iter().map(|&bound| { |
| astconv.instantiate_poly_trait_ref(bound, |
| param_ty, |
| &mut projection_bounds) |
| }).collect(); |
| |
| let region_bounds = region_bounds.into_iter().map(|r| { |
| astconv.ast_region_to_region(r, None) |
| }).collect(); |
| |
| trait_bounds.sort_by(|a,b| a.def_id().cmp(&b.def_id())); |
| |
| let implicitly_sized = if let SizedByDefault::Yes = sized_by_default { |
| !is_unsized(astconv, ast_bounds, span) |
| } else { |
| false |
| }; |
| |
| Bounds { |
| region_bounds, |
| implicitly_sized, |
| trait_bounds, |
| projection_bounds, |
| } |
| } |
| |
| /// Converts a specific TyParamBound from the AST into a set of |
| /// predicates that apply to the self-type. A vector is returned |
| /// because this can be anywhere from 0 predicates (`T:?Sized` adds no |
| /// predicates) to 1 (`T:Foo`) to many (`T:Bar<X=i32>` adds `T:Bar` |
| /// and `<T as Bar>::X == i32`). |
| fn predicates_from_bound<'tcx>(astconv: &AstConv<'tcx, 'tcx>, |
| param_ty: Ty<'tcx>, |
| bound: &hir::TyParamBound) |
| -> Vec<ty::Predicate<'tcx>> |
| { |
| match *bound { |
| hir::TraitTyParamBound(ref tr, hir::TraitBoundModifier::None) => { |
| let mut projections = Vec::new(); |
| let pred = astconv.instantiate_poly_trait_ref(tr, |
| param_ty, |
| &mut projections); |
| projections.into_iter() |
| .map(|p| p.to_predicate()) |
| .chain(Some(pred.to_predicate())) |
| .collect() |
| } |
| hir::RegionTyParamBound(ref lifetime) => { |
| let region = astconv.ast_region_to_region(lifetime, None); |
| let pred = ty::Binder(ty::OutlivesPredicate(param_ty, region)); |
| vec![ty::Predicate::TypeOutlives(pred)] |
| } |
| hir::TraitTyParamBound(_, hir::TraitBoundModifier::Maybe) => { |
| Vec::new() |
| } |
| } |
| } |
| |
| fn compute_sig_of_foreign_fn_decl<'a, 'tcx>( |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId, |
| decl: &hir::FnDecl, |
| abi: abi::Abi) |
| -> ty::PolyFnSig<'tcx> |
| { |
| let fty = AstConv::ty_of_fn(&ItemCtxt::new(tcx, def_id), hir::Unsafety::Unsafe, abi, decl); |
| |
| // feature gate SIMD types in FFI, since I (huonw) am not sure the |
| // ABIs are handled at all correctly. |
| if abi != abi::Abi::RustIntrinsic && abi != abi::Abi::PlatformIntrinsic |
| && !tcx.sess.features.borrow().simd_ffi { |
| let check = |ast_ty: &hir::Ty, ty: Ty| { |
| if ty.is_simd() { |
| tcx.sess.struct_span_err(ast_ty.span, |
| &format!("use of SIMD type `{}` in FFI is highly experimental and \ |
| may result in invalid code", |
| tcx.hir.node_to_pretty_string(ast_ty.id))) |
| .help("add #![feature(simd_ffi)] to the crate attributes to enable") |
| .emit(); |
| } |
| }; |
| for (input, ty) in decl.inputs.iter().zip(*fty.inputs().skip_binder()) { |
| check(&input, ty) |
| } |
| if let hir::Return(ref ty) = decl.output { |
| check(&ty, *fty.output().skip_binder()) |
| } |
| } |
| |
| fty |
| } |
| |
| fn is_foreign_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId) |
| -> bool { |
| match tcx.hir.get_if_local(def_id) { |
| Some(hir_map::NodeForeignItem(..)) => true, |
| Some(_) => false, |
| _ => bug!("is_foreign_item applied to non-local def-id {:?}", def_id) |
| } |
| } |
| |
| fn is_default_impl<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId) |
| -> bool { |
| match tcx.hir.get_if_local(def_id) { |
| Some(hir_map::NodeItem(&hir::Item { node: hir::ItemDefaultImpl(..), .. })) |
| => true, |
| Some(_) => false, |
| _ => bug!("is_default_impl applied to non-local def-id {:?}", def_id) |
| } |
| } |
