| //! "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 constrained_type_params as ctp; |
| use check::intrinsic::intrisic_operation_unsafety; |
| use lint; |
| use middle::lang_items::SizedTraitLangItem; |
| use middle::resolve_lifetime as rl; |
| use middle::weak_lang_items; |
| use rustc::mir::mono::Linkage; |
| use rustc::ty::query::Providers; |
| use rustc::ty::query::queries; |
| use rustc::ty::subst::Substs; |
| use rustc::ty::util::Discr; |
| use rustc::ty::util::IntTypeExt; |
| use rustc::ty::{self, AdtKind, ToPolyTraitRef, Ty, TyCtxt}; |
| use rustc::ty::{ReprOptions, ToPredicate}; |
| use rustc::util::captures::Captures; |
| use rustc::util::nodemap::FxHashMap; |
| use rustc_data_structures::sync::Lrc; |
| use rustc_target::spec::abi; |
| |
| use syntax::ast; |
| use syntax::ast::{Ident, MetaItemKind}; |
| use syntax::attr::{InlineAttr, list_contains_name, mark_used}; |
| use syntax::source_map::Spanned; |
| use syntax::feature_gate; |
| use syntax::symbol::{keywords, Symbol}; |
| use syntax_pos::{Span, DUMMY_SP}; |
| |
| use rustc::hir::def::{CtorKind, Def}; |
| use rustc::hir::Node; |
| use rustc::hir::def_id::{DefId, LOCAL_CRATE}; |
| use rustc::hir::intravisit::{self, NestedVisitorMap, Visitor}; |
| use rustc::hir::GenericParamKind; |
| use rustc::hir::{self, CodegenFnAttrFlags, CodegenFnAttrs, Unsafety}; |
| |
| use std::iter; |
| |
| struct OnlySelfBounds(bool); |
| |
| /////////////////////////////////////////////////////////////////////////// |
| // Main entry point |
| |
| pub fn collect_item_types<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) { |
| for &module in tcx.hir().krate().modules.keys() { |
| queries::collect_mod_item_types::ensure(tcx, tcx.hir().local_def_id(module)); |
| } |
| } |
| |
| fn collect_mod_item_types<'tcx>(tcx: TyCtxt<'_, 'tcx, 'tcx>, module_def_id: DefId) { |
| tcx.hir().visit_item_likes_in_module( |
| module_def_id, |
| &mut CollectItemTypesVisitor { tcx }.as_deep_visitor() |
| ); |
| } |
| |
| pub fn provide(providers: &mut Providers) { |
| *providers = Providers { |
| type_of, |
| generics_of, |
| predicates_of, |
| predicates_defined_on, |
| explicit_predicates_of, |
| super_predicates_of, |
| type_param_predicates, |
| trait_def, |
| adt_def, |
| fn_sig, |
| impl_trait_ref, |
| impl_polarity, |
| is_foreign_item, |
| codegen_fn_attrs, |
| collect_mod_item_types, |
| ..*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.params { |
| match param.kind { |
| hir::GenericParamKind::Lifetime { .. } => {} |
| hir::GenericParamKind::Type { |
| default: Some(_), .. |
| } => { |
| let def_id = self.tcx.hir().local_def_id(param.id); |
| self.tcx.type_of(def_id); |
| } |
| hir::GenericParamKind::Type { .. } => {} |
| } |
| } |
| intravisit::walk_generics(self, generics); |
| } |
| |
| fn visit_expr(&mut self, expr: &'tcx hir::Expr) { |
| if let hir::ExprKind::Closure(..) = 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_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) |
| -> Lrc<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::GenericParamDef>, |
| ) -> 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) = poly_trait_ref.no_bound_vars() { |
| 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), |
| ) -> Lrc<ty::GenericPredicates<'tcx>> { |
| 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.param_def_id_to_index[&def_id]; |
| let ty = tcx.mk_ty_param(index, tcx.hir().ty_param_name(param_id).as_interned_str()); |
| |
| // 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_else( |
| || Lrc::new(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) { |
| Node::TraitItem(item) => &item.generics, |
| |
| Node::ImplItem(item) => &item.generics, |
| |
| Node::Item(item) => { |
| match item.node { |
| ItemKind::Fn(.., ref generics, _) |
| | ItemKind::Impl(_, _, _, ref generics, ..) |
| | ItemKind::Ty(_, ref generics) |
| | ItemKind::Existential(ExistTy { |
| ref generics, |
| impl_trait_fn: None, |
| .. |
| }) |
| | ItemKind::Enum(_, ref generics) |
| | ItemKind::Struct(_, ref generics) |
| | ItemKind::Union(_, ref generics) => generics, |
| ItemKind::Trait(_, _, ref generics, ..) => { |
| // Implied `Self: Trait` and supertrait bounds. |
| if param_id == item_node_id { |
| let identity_trait_ref = ty::TraitRef::identity(tcx, item_def_id); |
| Lrc::make_mut(&mut result) |
| .predicates |
| .push((identity_trait_ref.to_predicate(), item.span)); |
| } |
| generics |
| } |
| _ => return result, |
| } |
| } |
| |
| Node::ForeignItem(item) => match item.node { |
| ForeignItemKind::Fn(_, _, ref generics) => generics, |
| _ => return result, |
| }, |
| |
| _ => return result, |
| }; |
| |
| let icx = ItemCtxt::new(tcx, item_def_id); |
| Lrc::make_mut(&mut result) |
| .predicates |
| .extend(icx.type_parameter_bounds_in_generics(ast_generics, param_id, ty, |
| OnlySelfBounds(true))); |
| 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>, |
| only_self_bounds: OnlySelfBounds, |
| ) -> Vec<(ty::Predicate<'tcx>, Span)> { |
| let from_ty_params = ast_generics |
| .params |
| .iter() |
| .filter_map(|param| match param.kind { |
| GenericParamKind::Type { .. } if param.id == param_id => Some(¶m.bounds), |
| _ => None, |
| }) |
| .flat_map(|bounds| 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, |
| }) |
| .flat_map(|bp| { |
| let bt = if is_param(self.tcx, &bp.bounded_ty, param_id) { |
| Some(ty) |
| } else if !only_self_bounds.0 { |
| Some(self.to_ty(&bp.bounded_ty)) |
| } else { |
| None |
| }; |
| bp.bounds.iter().filter_map(move |b| bt.map(|bt| (bt, b))) |
| }) |
| .flat_map(|(bt, b)| predicates_from_bound(self, bt, 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::TyKind::Path(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 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.ident, it.id); |
| let def_id = tcx.hir().local_def_id(item_id); |
| match it.node { |
| // These don't define types. |
| hir::ItemKind::ExternCrate(_) |
| | hir::ItemKind::Use(..) |
| | hir::ItemKind::Mod(_) |
| | hir::ItemKind::GlobalAsm(_) => {} |
| hir::ItemKind::ForeignMod(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::ForeignItemKind::Fn(..) = item.node { |
| tcx.fn_sig(def_id); |
| } |
| } |
| } |
| hir::ItemKind::Enum(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::ItemKind::Impl(..) => { |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.impl_trait_ref(def_id); |
| tcx.predicates_of(def_id); |
| } |
| hir::ItemKind::Trait(..) => { |
| 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::ItemKind::TraitAlias(..) => { |
| tcx.generics_of(def_id); |
| tcx.at(it.span).super_predicates_of(def_id); |
| tcx.predicates_of(def_id); |
| } |
| hir::ItemKind::Struct(ref struct_def, _) | hir::ItemKind::Union(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()); |
| } |
| } |
| |
| // Desugared from `impl Trait` -> visited by the function's return type |
| hir::ItemKind::Existential(hir::ExistTy { |
| impl_trait_fn: Some(_), |
| .. |
| }) => {} |
| |
| hir::ItemKind::Existential(..) |
| | hir::ItemKind::Ty(..) |
| | hir::ItemKind::Static(..) |
| | hir::ItemKind::Const(..) |
| | hir::ItemKind::Fn(..) => { |
| tcx.generics_of(def_id); |
| tcx.type_of(def_id); |
| tcx.predicates_of(def_id); |
| if let hir::ItemKind::Fn(..) = 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 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::<Discr<'tcx>>; |
| |
| // fill the discriminant values and field types |
| for variant in variants { |
| let wrapped_discr = prev_discr.map_or(initial, |d| d.wrap_incr(tcx)); |
| prev_discr = Some( |
| if let Some(ref e) = variant.node.disr_expr { |
| let expr_did = tcx.hir().local_def_id(e.id); |
| def.eval_explicit_discr(tcx, expr_did) |
| } 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.ident, 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_variant<'a, 'tcx>( |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| did: DefId, |
| ident: Ident, |
| discr: ty::VariantDiscr, |
| def: &hir::VariantData, |
| adt_kind: ty::AdtKind, |
| attribute_def_id: DefId |
| ) -> ty::VariantDef { |
| let mut seen_fields: FxHashMap<ast::Ident, Span> = Default::default(); |
| 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.ident.modern()).cloned(); |
| if let Some(prev_span) = dup_span { |
| struct_span_err!( |
| tcx.sess, |
| f.span, |
| E0124, |
| "field `{}` is already declared", |
| f.ident |
| ).span_label(f.span, "field already declared") |
| .span_label(prev_span, format!("`{}` first declared here", f.ident)) |
| .emit(); |
| } else { |
| seen_fields.insert(f.ident.modern(), f.span); |
| } |
| |
| ty::FieldDef { |
| did: fid, |
| ident: f.ident, |
| vis: ty::Visibility::from_hir(&f.vis, node_id, tcx), |
| } |
| }) |
| .collect(); |
| ty::VariantDef::new(tcx, |
| did, |
| ident, |
| discr, |
| fields, |
| adt_kind, |
| CtorKind::from_hir(def), |
| attribute_def_id |
| ) |
| } |
| |
| fn adt_def<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> &'tcx ty::AdtDef { |
| use rustc::hir::*; |
| |
| let node_id = tcx.hir().as_local_node_id(def_id).unwrap(); |
| let item = match tcx.hir().get(node_id) { |
| Node::Item(item) => item, |
| _ => bug!(), |
| }; |
| |
| let repr = ReprOptions::new(tcx, def_id); |
| let (kind, variants) = match item.node { |
| ItemKind::Enum(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(ref e) = v.node.disr_expr { |
| distance_from_explicit = 0; |
| ty::VariantDiscr::Explicit(tcx.hir().local_def_id(e.id)) |
| } else { |
| ty::VariantDiscr::Relative(distance_from_explicit) |
| }; |
| distance_from_explicit += 1; |
| |
| convert_variant(tcx, did, v.node.ident, discr, &v.node.data, AdtKind::Enum, |
| did) |
| }) |
| .collect(), |
| ) |
| } |
| ItemKind::Struct(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, |
| std::iter::once(convert_variant( |
| tcx, |
| ctor_id.unwrap_or(def_id), |
| item.ident, |
| ty::VariantDiscr::Relative(0), |
| def, |
| AdtKind::Struct, |
| def_id |
| )).collect(), |
| ) |
| } |
| ItemKind::Union(ref def, _) => ( |
| AdtKind::Union, |
| std::iter::once(convert_variant( |
| tcx, |
| def_id, |
| item.ident, |
| ty::VariantDiscr::Relative(0), |
| def, |
| AdtKind::Union, |
| def_id |
| )).collect(), |
| ), |
| _ => 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, |
| ) -> Lrc<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) { |
| Node::Item(item) => item, |
| _ => bug!("trait_node_id {} is not an item", trait_node_id), |
| }; |
| |
| let (generics, bounds) = match item.node { |
| hir::ItemKind::Trait(.., ref generics, ref supertraits, _) => (generics, supertraits), |
| hir::ItemKind::TraitAlias(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`. |
| // In the case of trait aliases, however, we include all bounds in the where clause, |
| // so e.g., `trait Foo = where u32: PartialEq<Self>` would include `u32: PartialEq<Self>` |
| // as one of its "superpredicates". |
| let is_trait_alias = ty::is_trait_alias(tcx, trait_def_id); |
| let superbounds2 = icx.type_parameter_bounds_in_generics( |
| generics, item.id, self_param_ty, OnlySelfBounds(!is_trait_alias)); |
| |
| // 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 &(pred, span) in &superbounds { |
| debug!("superbound: {:?}", pred); |
| if let ty::Predicate::Trait(bound) = pred { |
| tcx.at(span).super_predicates_of(bound.def_id()); |
| } |
| } |
| |
| Lrc::new(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 (is_auto, unsafety) = match item.node { |
| hir::ItemKind::Trait(is_auto, unsafety, ..) => (is_auto == hir::IsAuto::Yes, unsafety), |
| hir::ItemKind::TraitAlias(..) => (false, hir::Unsafety::Normal), |
| _ => 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.features().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 is_marker = tcx.has_attr(def_id, "marker"); |
| let def_path_hash = tcx.def_path_hash(def_id); |
| let def = ty::TraitDef::new(def_id, unsafety, paren_sugar, is_auto, is_marker, def_path_hash); |
| tcx.alloc_trait_def(def) |
| } |
| |
| fn has_late_bound_regions<'a, 'tcx>( |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| node: Node<'tcx>, |
| ) -> Option<Span> { |
| struct LateBoundRegionsDetector<'a, 'tcx: 'a> { |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| outer_index: ty::DebruijnIndex, |
| 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::TyKind::BareFn(..) => { |
| self.outer_index.shift_in(1); |
| intravisit::walk_ty(self, ty); |
| self.outer_index.shift_out(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.outer_index.shift_in(1); |
| intravisit::walk_poly_trait_ref(self, tr, m); |
| self.outer_index.shift_out(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 < self.outer_index => {} |
| Some(rl::Region::LateBound(..)) |
| | Some(rl::Region::LateBoundAnon(..)) |
| | Some(rl::Region::Free(..)) |
| | None => { |
| 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, |
| outer_index: ty::INNERMOST, |
| has_late_bound_regions: None, |
| }; |
| for param in &generics.params { |
| if let GenericParamKind::Lifetime { .. } = param.kind { |
| let hir_id = tcx.hir().node_to_hir_id(param.id); |
| if tcx.is_late_bound(hir_id) { |
| return Some(param.span); |
| } |
| } |
| } |
| visitor.visit_fn_decl(decl); |
| visitor.has_late_bound_regions |
| } |
| |
| match node { |
| Node::TraitItem(item) => match item.node { |
| hir::TraitItemKind::Method(ref sig, _) => { |
| has_late_bound_regions(tcx, &item.generics, &sig.decl) |
| } |
| _ => None, |
| }, |
| Node::ImplItem(item) => match item.node { |
| hir::ImplItemKind::Method(ref sig, _) => { |
| has_late_bound_regions(tcx, &item.generics, &sig.decl) |
| } |
| _ => None, |
| }, |
| Node::ForeignItem(item) => match item.node { |
| hir::ForeignItemKind::Fn(ref fn_decl, _, ref generics) => { |
| has_late_bound_regions(tcx, generics, fn_decl) |
| } |
| _ => None, |
| }, |
| Node::Item(item) => match item.node { |
| hir::ItemKind::Fn(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::*; |
| |
| 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 { |
| Node::ImplItem(_) | Node::TraitItem(_) | Node::Variant(_) |
| | Node::StructCtor(_) | Node::Field(_) => { |
| let parent_id = tcx.hir().get_parent(node_id); |
| Some(tcx.hir().local_def_id(parent_id)) |
| } |
| Node::Expr(&hir::Expr { |
| node: hir::ExprKind::Closure(..), |
| .. |
| }) => Some(tcx.closure_base_def_id(def_id)), |
| Node::Item(item) => match item.node { |
| ItemKind::Existential(hir::ExistTy { impl_trait_fn, .. }) => impl_trait_fn, |
| _ => None, |
| }, |
| _ => None, |
| }; |
| |
| let mut opt_self = None; |
| let mut allow_defaults = false; |
| |
| let no_generics = hir::Generics::empty(); |
| let ast_generics = match node { |
| Node::TraitItem(item) => &item.generics, |
| |
| Node::ImplItem(item) => &item.generics, |
| |
| Node::Item(item) => { |
| match item.node { |
| ItemKind::Fn(.., ref generics, _) | ItemKind::Impl(_, _, _, ref generics, ..) => { |
| generics |
| } |
| |
| ItemKind::Ty(_, ref generics) |
| | ItemKind::Enum(_, ref generics) |
| | ItemKind::Struct(_, ref generics) |
| | ItemKind::Existential(hir::ExistTy { ref generics, .. }) |
| | ItemKind::Union(_, ref generics) => { |
| allow_defaults = true; |
| generics |
| } |
| |
| ItemKind::Trait(_, _, ref generics, ..) |
| | ItemKind::TraitAlias(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::GenericParamDef { |
| index: 0, |
| name: keywords::SelfUpper.name().as_interned_str(), |
| def_id: tcx.hir().local_def_id(param_id), |
| pure_wrt_drop: false, |
| kind: ty::GenericParamDefKind::Type { |
| has_default: false, |
| object_lifetime_default: rl::Set1::Empty, |
| synthetic: None, |
| }, |
| }); |
| |
| allow_defaults = true; |
| generics |
| } |
| |
| _ => &no_generics, |
| } |
| } |
| |
| Node::ForeignItem(item) => match item.node { |
| ForeignItemKind::Static(..) => &no_generics, |
| ForeignItemKind::Fn(_, _, ref generics) => generics, |
| ForeignItemKind::Type => &no_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_count = parent_def_id.map_or(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_count + generics.params.len() |
| }); |
| |
| let mut params: Vec<_> = opt_self.into_iter().collect(); |
| |
| let early_lifetimes = early_bound_lifetimes_from_generics(tcx, ast_generics); |
| params.extend( |
| early_lifetimes |
| .enumerate() |
| .map(|(i, param)| ty::GenericParamDef { |
| name: param.name.ident().as_interned_str(), |
| index: own_start + i as u32, |
| def_id: tcx.hir().local_def_id(param.id), |
| pure_wrt_drop: param.pure_wrt_drop, |
| kind: ty::GenericParamDefKind::Lifetime, |
| }), |
| ); |
| |
| 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 - has_self as u32 + params.len() as u32; |
| let mut i = 0; |
| params.extend( |
| ast_generics |
| .params |
| .iter() |
| .filter_map(|param| match param.kind { |
| GenericParamKind::Type { |
| ref default, |
| synthetic, |
| .. |
| } => { |
| if param.name.ident().name == keywords::SelfUpper.name() { |
| span_bug!( |
| param.span, |
| "`Self` should not be the name of a regular parameter" |
| ); |
| } |
| |
| if !allow_defaults && default.is_some() { |
| if !tcx.features().default_type_parameter_fallback { |
| tcx.lint_node( |
| lint::builtin::INVALID_TYPE_PARAM_DEFAULT, |
| param.id, |
| param.span, |
| &format!( |
| "defaults for type parameters are only allowed in \ |
| `struct`, `enum`, `type`, or `trait` definitions." |
| ), |
| ); |
| } |
| } |
| |
| let ty_param = ty::GenericParamDef { |
| index: type_start + i as u32, |
| name: param.name.ident().as_interned_str(), |
| def_id: tcx.hir().local_def_id(param.id), |
| pure_wrt_drop: param.pure_wrt_drop, |
| kind: ty::GenericParamDefKind::Type { |
| has_default: default.is_some(), |
| object_lifetime_default: object_lifetime_defaults |
| .as_ref() |
| .map_or(rl::Set1::Empty, |o| o[i]), |
| synthetic, |
| }, |
| }; |
| i += 1; |
| Some(ty_param) |
| } |
| _ => None, |
| }), |
| ); |
| |
| // 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 Node::Expr(&hir::Expr { |
| node: hir::ExprKind::Closure(.., gen), |
| .. |
| }) = node |
| { |
| let dummy_args = if gen.is_some() { |
| &["<yield_ty>", "<return_ty>", "<witness>"][..] |
| } else { |
| &["<closure_kind>", "<closure_signature>"][..] |
| }; |
| |
| params.extend( |
| dummy_args |
| .iter() |
| .enumerate() |
| .map(|(i, &arg)| ty::GenericParamDef { |
| index: type_start + i as u32, |
| name: Symbol::intern(arg).as_interned_str(), |
| def_id, |
| pure_wrt_drop: false, |
| kind: ty::GenericParamDefKind::Type { |
| has_default: false, |
| object_lifetime_default: rl::Set1::Empty, |
| synthetic: None, |
| }, |
| }), |
| ); |
| |
| tcx.with_freevars(node_id, |fv| { |
| params.extend(fv.iter().zip((dummy_args.len() as u32)..).map(|(_, i)| { |
| ty::GenericParamDef { |
| index: type_start + i, |
| name: Symbol::intern("<upvar>").as_interned_str(), |
| def_id, |
| pure_wrt_drop: false, |
| kind: ty::GenericParamDefKind::Type { |
| has_default: false, |
| object_lifetime_default: rl::Set1::Empty, |
| synthetic: None, |
| }, |
| } |
| })); |
| }); |
| } |
| |
| let param_def_id_to_index = params |
| .iter() |
| .map(|param| (param.def_id, param.index)) |
| .collect(); |
| |
| tcx.alloc_generics(ty::Generics { |
| parent: parent_def_id, |
| parent_count, |
| params, |
| param_def_id_to_index, |
| has_self: has_self || parent_has_self, |
| has_late_bound_regions: has_late_bound_regions(tcx, node), |
| }) |
| } |
| |
| fn report_assoc_ty_on_inherent_impl<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, span: Span) { |
| span_err!( |
| tcx.sess, |
| span, |
| E0202, |
| "associated types are not yet supported in inherent impls (see #8995)" |
| ); |
| } |
| |
| fn type_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> Ty<'tcx> { |
| 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) { |
| Node::TraitItem(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"); |
| } |
| }, |
| |
| Node::ImplItem(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::Existential(_) => { |
| if tcx |
| .impl_trait_ref(tcx.hir().get_parent_did(node_id)) |
| .is_none() |
| { |
| report_assoc_ty_on_inherent_impl(tcx, item.span); |
| } |
| |
| find_existential_constraints(tcx, def_id) |
| } |
| ImplItemKind::Type(ref ty) => { |
| if tcx |
| .impl_trait_ref(tcx.hir().get_parent_did(node_id)) |
| .is_none() |
| { |
| report_assoc_ty_on_inherent_impl(tcx, item.span); |
| } |
| |
| icx.to_ty(ty) |
| } |
| }, |
| |
| Node::Item(item) => { |
| match item.node { |
| ItemKind::Static(ref t, ..) |
| | ItemKind::Const(ref t, _) |
| | ItemKind::Ty(ref t, _) |
| | ItemKind::Impl(.., ref t, _) => icx.to_ty(t), |
| ItemKind::Fn(..) => { |
| let substs = Substs::identity_for_item(tcx, def_id); |
| tcx.mk_fn_def(def_id, substs) |
| } |
| ItemKind::Enum(..) | ItemKind::Struct(..) | ItemKind::Union(..) => { |
| let def = tcx.adt_def(def_id); |
| let substs = Substs::identity_for_item(tcx, def_id); |
| tcx.mk_adt(def, substs) |
| } |
| ItemKind::Existential(hir::ExistTy { |
| impl_trait_fn: None, |
| .. |
| }) => find_existential_constraints(tcx, def_id), |
| // existential types desugared from impl Trait |
| ItemKind::Existential(hir::ExistTy { |
| impl_trait_fn: Some(owner), |
| .. |
| }) => { |
| tcx.typeck_tables_of(owner) |
| .concrete_existential_types |
| .get(&def_id) |
| .cloned() |
| .unwrap_or_else(|| { |
| // This can occur if some error in the |
| // owner fn prevented us from populating |
| // the `concrete_existential_types` table. |
| tcx.sess.delay_span_bug( |
| DUMMY_SP, |
| &format!( |
| "owner {:?} has no existential type for {:?} in its tables", |
| owner, def_id, |
| ), |
| ); |
| tcx.types.err |
| }) |
| } |
| ItemKind::Trait(..) |
| | ItemKind::TraitAlias(..) |
| | ItemKind::Mod(..) |
| | ItemKind::ForeignMod(..) |
| | ItemKind::GlobalAsm(..) |
| | ItemKind::ExternCrate(..) |
| | ItemKind::Use(..) => { |
| span_bug!( |
| item.span, |
| "compute_type_of_item: unexpected item type: {:?}", |
| item.node |
| ); |
| } |
| } |
| } |
| |
| Node::ForeignItem(foreign_item) => match foreign_item.node { |
| ForeignItemKind::Fn(..) => { |
| let substs = Substs::identity_for_item(tcx, def_id); |
| tcx.mk_fn_def(def_id, substs) |
| } |
| ForeignItemKind::Static(ref t, _) => icx.to_ty(t), |
| ForeignItemKind::Type => tcx.mk_foreign(def_id), |
| }, |
| |
| Node::StructCtor(&ref def) |
| | Node::Variant(&Spanned { |
| node: hir::VariantKind { 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) |
| } |
| }, |
| |
| Node::Field(field) => icx.to_ty(&field.ty), |
| |
| Node::Expr(&hir::Expr { |
| node: hir::ExprKind::Closure(.., gen), |
| .. |
| }) => { |
| if gen.is_some() { |
| let hir_id = tcx.hir().node_to_hir_id(node_id); |
| return tcx.typeck_tables_of(def_id).node_id_to_type(hir_id); |
| } |
| |
| let substs = ty::ClosureSubsts { |
| substs: Substs::identity_for_item(tcx, def_id), |
| }; |
| |
| tcx.mk_closure(def_id, substs) |
| } |
| |
| Node::AnonConst(_) => match tcx.hir().get(tcx.hir().get_parent_node(node_id)) { |
| Node::Ty(&hir::Ty { |
| node: hir::TyKind::Array(_, ref constant), |
| .. |
| }) |
| | Node::Ty(&hir::Ty { |
| node: hir::TyKind::Typeof(ref constant), |
| .. |
| }) |
| | Node::Expr(&hir::Expr { |
| node: ExprKind::Repeat(_, ref constant), |
| .. |
| }) if constant.id == node_id => |
| { |
| tcx.types.usize |
| } |
| |
| Node::Variant(&Spanned { |
| node: |
| VariantKind { |
| disr_expr: Some(ref e), |
| .. |
| }, |
| .. |
| }) if e.id == node_id => |
| { |
| tcx.adt_def(tcx.hir().get_parent_did(node_id)) |
| .repr |
| .discr_type() |
| .to_ty(tcx) |
| } |
| |
| x => { |
| bug!("unexpected const parent in type_of_def_id(): {:?}", x); |
| } |
| }, |
| |
| Node::GenericParam(param) => match param.kind { |
| hir::GenericParamKind::Type { |
| default: Some(ref ty), |
| .. |
| } => icx.to_ty(ty), |
| _ => bug!("unexpected non-type NodeGenericParam"), |
| }, |
| |
| x => { |
| bug!("unexpected sort of node in type_of_def_id(): {:?}", x); |
| } |
| } |
| } |
| |
| fn find_existential_constraints<'a, 'tcx>( |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId, |
| ) -> ty::Ty<'tcx> { |
| use rustc::hir::*; |
| |
| struct ConstraintLocator<'a, 'tcx: 'a> { |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId, |
| found: Option<(Span, ty::Ty<'tcx>)>, |
| } |
| |
| impl<'a, 'tcx> ConstraintLocator<'a, 'tcx> { |
| fn check(&mut self, def_id: DefId) { |
| trace!("checking {:?}", def_id); |
| // don't try to check items that cannot possibly constrain the type |
| if !self.tcx.has_typeck_tables(def_id) { |
| trace!("no typeck tables for {:?}", def_id); |
| return; |
| } |
| let ty = self |
| .tcx |
| .typeck_tables_of(def_id) |
| .concrete_existential_types |
| .get(&self.def_id) |
| .cloned(); |
| if let Some(ty) = ty { |
| // FIXME(oli-obk): trace the actual span from inference to improve errors |
| let span = self.tcx.def_span(def_id); |
| if let Some((prev_span, prev_ty)) = self.found { |
| if ty != prev_ty { |
| // found different concrete types for the existential type |
| let mut err = self.tcx.sess.struct_span_err( |
| span, |
| "defining existential type use differs from previous", |
| ); |
| err.span_note(prev_span, "previous use here"); |
| err.emit(); |
| } |
| } else { |
| self.found = Some((span, ty)); |
| } |
| } |
| } |
| } |
| |
| impl<'a, 'tcx> intravisit::Visitor<'tcx> for ConstraintLocator<'a, 'tcx> { |
| fn nested_visit_map<'this>(&'this mut self) -> intravisit::NestedVisitorMap<'this, 'tcx> { |
| intravisit::NestedVisitorMap::All(&self.tcx.hir()) |
| } |
| fn visit_item(&mut self, it: &'tcx Item) { |
| let def_id = self.tcx.hir().local_def_id(it.id); |
| // the existential type itself or its children are not within its reveal scope |
| if def_id != self.def_id { |
| self.check(def_id); |
| intravisit::walk_item(self, it); |
| } |
| } |
| fn visit_impl_item(&mut self, it: &'tcx ImplItem) { |
| let def_id = self.tcx.hir().local_def_id(it.id); |
| // the existential type itself or its children are not within its reveal scope |
| if def_id != self.def_id { |
| self.check(def_id); |
| intravisit::walk_impl_item(self, it); |
| } |
| } |
| fn visit_trait_item(&mut self, it: &'tcx TraitItem) { |
| let def_id = self.tcx.hir().local_def_id(it.id); |
| self.check(def_id); |
| intravisit::walk_trait_item(self, it); |
| } |
| } |
| |
| let mut locator = ConstraintLocator { |
| def_id, |
| tcx, |
| found: None, |
| }; |
| let node_id = tcx.hir().as_local_node_id(def_id).unwrap(); |
| let parent = tcx.hir().get_parent(node_id); |
| |
| trace!("parent_id: {:?}", parent); |
| |
| if parent == ast::CRATE_NODE_ID { |
| intravisit::walk_crate(&mut locator, tcx.hir().krate()); |
| } else { |
| trace!("parent: {:?}", tcx.hir().get(parent)); |
| match tcx.hir().get(parent) { |
| Node::Item(ref it) => intravisit::walk_item(&mut locator, it), |
| Node::ImplItem(ref it) => intravisit::walk_impl_item(&mut locator, it), |
| Node::TraitItem(ref it) => intravisit::walk_trait_item(&mut locator, it), |
| other => bug!( |
| "{:?} is not a valid parent of an existential type item", |
| other |
| ), |
| } |
| } |
| |
| match locator.found { |
| Some((_, ty)) => ty, |
| None => { |
| let span = tcx.def_span(def_id); |
| tcx.sess.span_err(span, "could not find defining uses"); |
| tcx.types.err |
| } |
| } |
| } |
| |
| fn fn_sig<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId) -> ty::PolyFnSig<'tcx> { |
| use rustc::hir::*; |
| use rustc::hir::Node::*; |
| |
| 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) { |
| TraitItem(hir::TraitItem { |
| node: TraitItemKind::Method(sig, _), |
| .. |
| }) |
| | ImplItem(hir::ImplItem { |
| node: ImplItemKind::Method(sig, _), |
| .. |
| }) => AstConv::ty_of_fn(&icx, sig.header.unsafety, sig.header.abi, &sig.decl), |
| |
| Item(hir::Item { |
| node: ItemKind::Fn(decl, header, _, _), |
| .. |
| }) => AstConv::ty_of_fn(&icx, header.unsafety, header.abi, decl), |
| |
| ForeignItem(&hir::ForeignItem { |
| node: ForeignItemKind::Fn(ref fn_decl, _, _), |
| .. |
| }) => { |
| let abi = tcx.hir().get_foreign_abi(node_id); |
| compute_sig_of_foreign_fn_decl(tcx, def_id, fn_decl, abi) |
| } |
| |
| StructCtor(&VariantData::Tuple(ref fields, _)) |
| | Variant(&Spanned { |
| node: |
| hir::VariantKind { |
| 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::bind(tcx.mk_fn_sig( |
| inputs, |
| ty, |
| false, |
| hir::Unsafety::Normal, |
| abi::Abi::Rust, |
| )) |
| } |
| |
| Expr(&hir::Expr { |
| node: hir::ExprKind::Closure(..), |
| .. |
| }) => { |
| // Closure signatures are not like other function |
| // signatures and cannot be accessed through `fn_sig`. For |
| // example, a closure signature excludes the `self` |
| // argument. In any case they are embedded within the |
| // closure type as part of the `ClosureSubsts`. |
| // |
| // To get |
| // the signature of a closure, you should use the |
| // `closure_sig` method on the `ClosureSubsts`: |
| // |
| // closure_substs.closure_sig(def_id, tcx) |
| // |
| // or, inside of an inference context, you can use |
| // |
| // infcx.closure_sig(def_id, closure_substs) |
| bug!("to get the signature of a closure, use `closure_sig()` not `fn_sig()`"); |
| } |
| |
| 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::ItemKind::Impl(.., 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::ItemKind::Impl(_, polarity, ..) => polarity, |
| ref item => bug!("impl_polarity: {:?} not an impl", item), |
| } |
| } |
| |
| // Is it marked with ?Sized |
| fn is_unsized<'gcx: 'tcx, 'tcx>( |
| astconv: &dyn AstConv<'gcx, 'tcx>, |
| ast_bounds: &[hir::GenericBound], |
| 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::GenericBound::Trait(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>, |
| generics: &'a hir::Generics, |
| ) -> impl Iterator<Item = &'a hir::GenericParam> + Captures<'tcx> { |
| generics |
| .params |
| .iter() |
| .filter(move |param| match param.kind { |
| GenericParamKind::Lifetime { .. } => { |
| let hir_id = tcx.hir().node_to_hir_id(param.id); |
| !tcx.is_late_bound(hir_id) |
| } |
| _ => false, |
| }) |
| } |
| |
| fn predicates_defined_on<'a, 'tcx>( |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId, |
| ) -> Lrc<ty::GenericPredicates<'tcx>> { |
| debug!("predicates_defined_on({:?})", def_id); |
| let mut result = tcx.explicit_predicates_of(def_id); |
| debug!( |
| "predicates_defined_on: explicit_predicates_of({:?}) = {:?}", |
| def_id, |
| result, |
| ); |
| let inferred_outlives = tcx.inferred_outlives_of(def_id); |
| if !inferred_outlives.is_empty() { |
| let span = tcx.def_span(def_id); |
| debug!( |
| "predicates_defined_on: inferred_outlives_of({:?}) = {:?}", |
| def_id, |
| inferred_outlives, |
| ); |
| Lrc::make_mut(&mut result) |
| .predicates |
| .extend(inferred_outlives.iter().map(|&p| (p, span))); |
| } |
| debug!("predicates_defined_on({:?}) = {:?}", def_id, result); |
| result |
| } |
| |
| fn predicates_of<'a, 'tcx>( |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId, |
| ) -> Lrc<ty::GenericPredicates<'tcx>> { |
| let mut result = tcx.predicates_defined_on(def_id); |
| |
| if tcx.is_trait(def_id) { |
| // For traits, add `Self: Trait` predicate. This is |
| // not part of the predicates that a user writes, but it |
| // is something that one must prove in order to invoke a |
| // method or project an associated type. |
| // |
| // In the chalk setup, this predicate is not part of the |
| // "predicates" for a trait item. But it is useful in |
| // rustc because if you directly (e.g.) invoke a trait |
| // method like `Trait::method(...)`, you must naturally |
| // prove that the trait applies to the types that were |
| // used, and adding the predicate into this list ensures |
| // that this is done. |
| let span = tcx.def_span(def_id); |
| Lrc::make_mut(&mut result) |
| .predicates |
| .push((ty::TraitRef::identity(tcx, def_id).to_predicate(), span)); |
| } |
| debug!("predicates_of(def_id={:?}) = {:?}", def_id, result); |
| result |
| } |
| |
| fn explicit_predicates_of<'a, 'tcx>( |
| tcx: TyCtxt<'a, 'tcx, 'tcx>, |
| def_id: DefId, |
| ) -> Lrc<ty::GenericPredicates<'tcx>> { |
| use rustc::hir::*; |
| use rustc_data_structures::fx::FxHashSet; |
| |
| debug!("explicit_predicates_of(def_id={:?})", def_id); |
| |
| /// A data structure with unique elements, which preserves order of insertion. |
| /// Preserving the order of insertion is important here so as not to break |
| /// compile-fail UI tests. |
| struct UniquePredicates<'tcx> { |
| predicates: Vec<(ty::Predicate<'tcx>, Span)>, |
| uniques: FxHashSet<(ty::Predicate<'tcx>, Span)>, |
| } |
| |
| impl<'tcx> UniquePredicates<'tcx> { |
| fn new() -> Self { |
| UniquePredicates { |
| predicates: vec![], |
| uniques: FxHashSet::default(), |
| } |
| } |
| |
| fn push(&mut self, value: (ty::Predicate<'tcx>, Span)) { |
| if self.uniques.insert(value) { |
| self.predicates.push(value); |
| } |
| } |
| |
| fn extend<I: IntoIterator<Item = (ty::Predicate<'tcx>, Span)>>(&mut self, iter: I) { |
| for value in iter { |
| self.push(value); |
| } |
| } |
| } |
| |
| 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 mut is_default_impl_trait = None; |
| |
| let icx = ItemCtxt::new(tcx, def_id); |
| let no_generics = hir::Generics::empty(); |
| let empty_trait_items = HirVec::new(); |
| |
| let mut predicates = UniquePredicates::new(); |
| |
| let ast_generics = match node { |
| Node::TraitItem(item) => &item.generics, |
| |
| Node::ImplItem(item) => match item.node { |
| ImplItemKind::Existential(ref bounds) => { |
| let substs = Substs::identity_for_item(tcx, def_id); |
| let opaque_ty = tcx.mk_opaque(def_id, substs); |
| |
| // Collect the bounds, i.e., the `A+B+'c` in `impl A+B+'c`. |
| let bounds = compute_bounds( |
| &icx, |
| opaque_ty, |
| bounds, |
| SizedByDefault::Yes, |
| tcx.def_span(def_id), |
| ); |
| |
| predicates.extend(bounds.predicates(tcx, opaque_ty)); |
| &item.generics |
| } |
| _ => &item.generics, |
| }, |
| |
| Node::Item(item) => { |
| match item.node { |
| ItemKind::Impl(_, _, defaultness, ref generics, ..) => { |
| if defaultness.is_default() { |
| is_default_impl_trait = tcx.impl_trait_ref(def_id); |
| } |
| generics |
| } |
| ItemKind::Fn(.., ref generics, _) |
| | ItemKind::Ty(_, ref generics) |
| | ItemKind::Enum(_, ref generics) |
| | ItemKind::Struct(_, ref generics) |
| | ItemKind::Union(_, ref generics) => generics, |
| |
| ItemKind::Trait(_, _, ref generics, .., ref items) => { |
| is_trait = Some((ty::TraitRef::identity(tcx, def_id), items)); |
| generics |
| } |
| ItemKind::TraitAlias(ref generics, _) => { |
| is_trait = Some((ty::TraitRef::identity(tcx, def_id), &empty_trait_items)); |
| generics |
| } |
| ItemKind::Existential(ExistTy { |
| ref bounds, |
| impl_trait_fn, |
| ref generics, |
| }) => { |
| let substs = Substs::identity_for_item(tcx, def_id); |
| let opaque_ty = tcx.mk_opaque(def_id, substs); |
| |
| // Collect the bounds, i.e., the `A+B+'c` in `impl A+B+'c`. |
| let bounds = compute_bounds( |
| &icx, |
| opaque_ty, |
| bounds, |
| SizedByDefault::Yes, |
| tcx.def_span(def_id), |
| ); |
| |
| if impl_trait_fn.is_some() { |
| // impl Trait |
| return Lrc::new(ty::GenericPredicates { |
| parent: None, |
| predicates: bounds.predicates(tcx, opaque_ty), |
| }); |
| } else { |
| // named existential types |
| predicates.extend(bounds.predicates(tcx, opaque_ty)); |
| generics |
| } |
| } |
| |
| _ => &no_generics, |
| } |
| } |
| |
| Node::ForeignItem(item) => match item.node { |
| ForeignItemKind::Static(..) => &no_generics, |
| ForeignItemKind::Fn(_, _, ref generics) => generics, |
| ForeignItemKind::Type => &no_generics, |
| }, |
| |
| _ => &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; |
| |
| // 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.extend(tcx.super_predicates_of(def_id).predicates.iter().cloned()); |
| } |
| |
| // In default impls, we can assume that the self type implements |
| // the trait. So in: |
| // |
| // default impl Foo for Bar { .. } |
| // |
| // we add a default where clause `Foo: Bar`. We do a similar thing for traits |
| // (see below). Recall that a default impl is not itself an impl, but rather a |
| // set of defaults that can be incorporated into another impl. |
| if let Some(trait_ref) = is_default_impl_trait { |
| predicates.push((trait_ref.to_poly_trait_ref().to_predicate(), tcx.def_span(def_id))); |
| } |
| |
| // 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.id), |
| index, |
| name: param.name.ident().as_interned_str(), |
| })); |
| index += 1; |
| |
| match param.kind { |
| GenericParamKind::Lifetime { .. } => { |
| param.bounds.iter().for_each(|bound| match bound { |
| hir::GenericBound::Outlives(lt) => { |
| let bound = AstConv::ast_region_to_region(&icx, <, None); |
| let outlives = ty::Binder::bind(ty::OutlivesPredicate(region, bound)); |
| predicates.push((outlives.to_predicate(), lt.span)); |
| } |
| _ => bug!(), |
| }); |
| } |
| _ => bug!(), |
| } |
| } |
| |
| // Collect the predicates that were written inline by the user on each |
| // type parameter (e.g., `<T:Foo>`). |
| for param in &ast_generics.params { |
| if let GenericParamKind::Type { .. } = param.kind { |
| let name = param.name.ident().as_interned_str(); |
| let param_ty = ty::ParamTy::new(index, name).to_ty(tcx); |
| index += 1; |
| |
| let sized = SizedByDefault::Yes; |
| let bounds = compute_bounds(&icx, param_ty, ¶m.bounds, sized, 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); |
| |
| // Keep the type around in a dummy predicate, in case of no bounds. |
| // That way, `where Ty:` is not a complete noop (see #53696) and `Ty` |
| // is still checked for WF. |
| if bound_pred.bounds.is_empty() { |
| if let ty::Param(_) = ty.sty { |
| // This is a `where T:`, which can be in the HIR from the |
| // transformation that moves `?Sized` to `T`'s declaration. |
| // We can skip the predicate because type parameters are |
| // trivially WF, but also we *should*, to avoid exposing |
| // users who never wrote `where Type:,` themselves, to |
| // compiler/tooling bugs from not handling WF predicates. |
| } else { |
| let span = bound_pred.bounded_ty.span; |
| let predicate = ty::OutlivesPredicate(ty, tcx.mk_region(ty::ReEmpty)); |
| predicates.push( |
| (ty::Predicate::TypeOutlives(ty::Binder::dummy(predicate)), span) |
| ); |
| } |
| } |
| |
| for bound in bound_pred.bounds.iter() { |
| match bound { |
| &hir::GenericBound::Trait(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.extend( |
| iter::once((trait_ref.to_predicate(), poly_trait_ref.span)).chain( |
| projections.iter().map(|&(p, span)| (p.to_predicate(), span) |
| ))); |
| } |
| |
| &hir::GenericBound::Outlives(ref lifetime) => { |
| let region = AstConv::ast_region_to_region(&icx, lifetime, None); |
| let pred = ty::Binder::bind(ty::OutlivesPredicate(ty, region)); |
| predicates.push((ty::Predicate::TypeOutlives(pred), lifetime.span)) |
| } |
| } |
| } |
| } |
| |
| &hir::WherePredicate::RegionPredicate(ref region_pred) => { |
| let r1 = AstConv::ast_region_to_region(&icx, ®ion_pred.lifetime, None); |
| predicates.extend(region_pred.bounds.iter().map(|bound| { |
| let (r2, span) = match bound { |
| hir::GenericBound::Outlives(lt) => { |
| (AstConv::ast_region_to_region(&icx, lt, None), lt.span) |
| } |
| _ => bug!(), |
| }; |
| let pred = ty::Binder::bind(ty::OutlivesPredicate(r1, r2)); |
| |
| (ty::Predicate::RegionOutlives(pred), span) |
| })) |
| } |
| |
| &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() |
| })) |
| } |
| |
| let mut predicates = predicates.predicates; |
| |
| // 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 Node::Item(&Item { |
| node: ItemKind::Impl(..), |
| .. |
| }) = 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), |
| ); |
| } |
| |
| let result = Lrc::new(ty::GenericPredicates { |
| parent: generics.parent, |
| predicates, |
| }); |
| debug!("explicit_predicates_of(def_id={:?}) = {:?}", def_id, result); |
| result |
| } |
| |
| 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 `Send`. |
| pub fn compute_bounds<'gcx: 'tcx, 'tcx>( |
| astconv: &dyn AstConv<'gcx, 'tcx>, |
| param_ty: Ty<'tcx>, |
| ast_bounds: &[hir::GenericBound], |
| sized_by_default: SizedByDefault, |
| span: Span, |
| ) -> Bounds<'tcx> { |
| let mut region_bounds = Vec::new(); |
| let mut trait_bounds = Vec::new(); |
| |
| for ast_bound in ast_bounds { |
| match *ast_bound { |
| hir::GenericBound::Trait(ref b, hir::TraitBoundModifier::None) => trait_bounds.push(b), |
| hir::GenericBound::Trait(_, hir::TraitBoundModifier::Maybe) => {} |
| hir::GenericBound::Outlives(ref l) => region_bounds.push(l), |
| } |
| } |
| |
| let mut projection_bounds = Vec::new(); |
| |
| let mut trait_bounds: Vec<_> = trait_bounds.iter().map(|&bound| { |
| let (poly_trait_ref, _) = astconv.instantiate_poly_trait_ref( |
| bound, |
| param_ty, |
| &mut projection_bounds, |
| ); |
| (poly_trait_ref, bound.span) |
| }).collect(); |
| |
| let region_bounds = region_bounds |
| .into_iter() |
| .map(|r| (astconv.ast_region_to_region(r, None), r.span)) |
| .collect(); |
| |
| trait_bounds.sort_by_key(|(t, _)| t.def_id()); |
| |
| let implicitly_sized = if let SizedByDefault::Yes = sized_by_default { |
| if !is_unsized(astconv, ast_bounds, span) { |
| Some(span) |
| } else { |
| None |
| } |
| } else { |
| None |
| }; |
| |
| Bounds { |
| region_bounds, |
| implicitly_sized, |
| trait_bounds, |
| projection_bounds, |
| } |
| } |
| |
| /// Converts a specific `GenericBound` from the AST into a set of |
| /// predicates that apply to the self-type. A vector is returned |
| /// because this can be anywhere from zero predicates (`T : ?Sized` adds no |
| /// predicates) to one (`T : Foo`) to many (`T : Bar<X=i32>` adds `T : Bar` |
| /// and `<T as Bar>::X == i32`). |
| fn predicates_from_bound<'tcx>( |
| astconv: &dyn AstConv<'tcx, 'tcx>, |
| param_ty: Ty<'tcx>, |
| bound: &hir::GenericBound, |
| ) -> Vec<(ty::Predicate<'tcx>, Span)> { |
| match *bound { |
| hir::GenericBound::Trait(ref tr, hir::TraitBoundModifier::None) => { |
| let mut projections = Vec::new(); |
| let (pred, _) = astconv.instantiate_poly_trait_ref(tr, param_ty, &mut projections); |
| iter::once((pred.to_predicate(), tr.span)).chain( |
| projections |
| .into_iter() |
| .map(|(p, span)| (p.to_predicate(), span)) |
| ).collect() |
| } |
| hir::GenericBound::Outlives(ref lifetime) => { |
| let region = astconv.ast_region_to_region(lifetime, None); |
| let pred = ty::Binder::bind(ty::OutlivesPredicate(param_ty, region)); |
| vec![(ty::Predicate::TypeOutlives(pred), lifetime.span)] |
| } |
| hir::GenericBound::Trait(_, hir::TraitBoundModifier::Maybe) => vec![], |
| } |
| } |
| |
| 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 unsafety = if abi == abi::Abi::RustIntrinsic { |
| intrisic_operation_unsafety(&*tcx.item_name(def_id).as_str()) |
| } else { |
| hir::Unsafety::Unsafe |
| }; |
| let fty = AstConv::ty_of_fn(&ItemCtxt::new(tcx, def_id), unsafety, 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.features().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(Node::ForeignItem(..)) => true, |
| Some(_) => false, |
| _ => bug!("is_foreign_item applied to non-local def-id {:?}", def_id), |
| } |
| } |
| |
| fn from_target_feature( |
| tcx: TyCtxt, |
| id: DefId, |
| attr: &ast::Attribute, |
| whitelist: &FxHashMap<String, Option<String>>, |
| target_features: &mut Vec<Symbol>, |
| ) { |
| let list = match attr.meta_item_list() { |
| Some(list) => list, |
| None => { |
| let msg = "#[target_feature] attribute must be of the form \ |
| #[target_feature(..)]"; |
| tcx.sess.span_err(attr.span, &msg); |
| return; |
| } |
| }; |
| let rust_features = tcx.features(); |
| for item in list { |
| // Only `enable = ...` is accepted in the meta item list |
| if !item.check_name("enable") { |
| let msg = "#[target_feature(..)] only accepts sub-keys of `enable` \ |
| currently"; |
| tcx.sess.span_err(item.span, &msg); |
| continue; |
| } |
| |
| // Must be of the form `enable = "..."` ( a string) |
| let value = match item.value_str() { |
| Some(value) => value, |
| None => { |
| let msg = "#[target_feature] attribute must be of the form \ |
| #[target_feature(enable = \"..\")]"; |
| tcx.sess.span_err(item.span, &msg); |
| continue; |
| } |
| }; |
| |
| // We allow comma separation to enable multiple features |
| target_features.extend(value.as_str().split(',').filter_map(|feature| { |
| // Only allow whitelisted features per platform |
| let feature_gate = match whitelist.get(feature) { |
| Some(g) => g, |
| None => { |
| let msg = format!( |
| "the feature named `{}` is not valid for \ |
| this target", |
| feature |
| ); |
| let mut err = tcx.sess.struct_span_err(item.span, &msg); |
| |
| if feature.starts_with("+") { |
| let valid = whitelist.contains_key(&feature[1..]); |
| if valid { |
| err.help("consider removing the leading `+` in the feature name"); |
| } |
| } |
| err.emit(); |
| return None; |
| } |
| }; |
| |
| // Only allow features whose feature gates have been enabled |
| let allowed = match feature_gate.as_ref().map(|s| &**s) { |
| Some("arm_target_feature") => rust_features.arm_target_feature, |
| Some("aarch64_target_feature") => rust_features.aarch64_target_feature, |
| Some("hexagon_target_feature") => rust_features.hexagon_target_feature, |
| Some("powerpc_target_feature") => rust_features.powerpc_target_feature, |
| Some("mips_target_feature") => rust_features.mips_target_feature, |
| Some("avx512_target_feature") => rust_features.avx512_target_feature, |
| Some("mmx_target_feature") => rust_features.mmx_target_feature, |
| Some("sse4a_target_feature") => rust_features.sse4a_target_feature, |
| Some("tbm_target_feature") => rust_features.tbm_target_feature, |
| Some("wasm_target_feature") => rust_features.wasm_target_feature, |
| Some("cmpxchg16b_target_feature") => rust_features.cmpxchg16b_target_feature, |
| Some("adx_target_feature") => rust_features.adx_target_feature, |
| Some(name) => bug!("unknown target feature gate {}", name), |
| None => true, |
| }; |
| if !allowed && id.is_local() { |
| feature_gate::emit_feature_err( |
| &tcx.sess.parse_sess, |
| feature_gate.as_ref().unwrap(), |
| item.span, |
| feature_gate::GateIssue::Language, |
| &format!("the target feature `{}` is currently unstable", feature), |
| ); |
| } |
| Some(Symbol::intern(feature)) |
| })); |
| } |
| } |
| |
| fn linkage_by_name<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, def_id: DefId, name: &str) -> Linkage { |
| use rustc::mir::mono::Linkage::*; |
| |
| // Use the names from src/llvm/docs/LangRef.rst here. Most types are only |
| // applicable to variable declarations and may not really make sense for |
| // Rust code in the first place but whitelist them anyway and trust that |
| // the user knows what s/he's doing. Who knows, unanticipated use cases |
| // may pop up in the future. |
| // |
| // ghost, dllimport, dllexport and linkonce_odr_autohide are not supported |
| // and don't have to be, LLVM treats them as no-ops. |
| match name { |
| "appending" => Appending, |
| "available_externally" => AvailableExternally, |
| "common" => Common, |
| "extern_weak" => ExternalWeak, |
| "external" => External, |
| "internal" => Internal, |
| "linkonce" => LinkOnceAny, |
| "linkonce_odr" => LinkOnceODR, |
| "private" => Private, |
| "weak" => WeakAny, |
| "weak_odr" => WeakODR, |
| _ => { |
| let span = tcx.hir().span_if_local(def_id); |
| if let Some(span) = span { |
| tcx.sess.span_fatal(span, "invalid linkage specified") |
| } else { |
| tcx.sess |
| .fatal(&format!("invalid linkage specified: {}", name)) |
| } |
| } |
| } |
| } |
| |
| fn codegen_fn_attrs<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, id: DefId) -> CodegenFnAttrs { |
| let attrs = tcx.get_attrs(id); |
| |
| let mut codegen_fn_attrs = CodegenFnAttrs::new(); |
| |
| let whitelist = tcx.target_features_whitelist(LOCAL_CRATE); |
| |
| let mut inline_span = None; |
| for attr in attrs.iter() { |
| if attr.check_name("cold") { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::COLD; |
| } else if attr.check_name("allocator") { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::ALLOCATOR; |
| } else if attr.check_name("unwind") { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::UNWIND; |
| } else if attr.check_name("rustc_allocator_nounwind") { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_ALLOCATOR_NOUNWIND; |
| } else if attr.check_name("naked") { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::NAKED; |
| } else if attr.check_name("no_mangle") { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_MANGLE; |
| } else if attr.check_name("rustc_std_internal_symbol") { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL; |
| } else if attr.check_name("no_debug") { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_DEBUG; |
| } else if attr.check_name("used") { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::USED; |
| } else if attr.check_name("thread_local") { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::THREAD_LOCAL; |
| } else if attr.check_name("inline") { |
| codegen_fn_attrs.inline = attrs.iter().fold(InlineAttr::None, |ia, attr| { |
| if attr.path != "inline" { |
| return ia; |
| } |
| let meta = match attr.meta() { |
| Some(meta) => meta.node, |
| None => return ia, |
| }; |
| match meta { |
| MetaItemKind::Word => { |
| mark_used(attr); |
| InlineAttr::Hint |
| } |
| MetaItemKind::List(ref items) => { |
| mark_used(attr); |
| inline_span = Some(attr.span); |
| if items.len() != 1 { |
| span_err!( |
| tcx.sess.diagnostic(), |
| attr.span, |
| E0534, |
| "expected one argument" |
| ); |
| InlineAttr::None |
| } else if list_contains_name(&items[..], "always") { |
| InlineAttr::Always |
| } else if list_contains_name(&items[..], "never") { |
| InlineAttr::Never |
| } else { |
| span_err!( |
| tcx.sess.diagnostic(), |
| items[0].span, |
| E0535, |
| "invalid argument" |
| ); |
| |
| InlineAttr::None |
| } |
| } |
| _ => ia, |
| } |
| }); |
| } else if attr.check_name("export_name") { |
| if let Some(s) = attr.value_str() { |
| if s.as_str().contains("\0") { |
| // `#[export_name = ...]` will be converted to a null-terminated string, |
| // so it may not contain any null characters. |
| struct_span_err!( |
| tcx.sess, |
| attr.span, |
| E0648, |
| "`export_name` may not contain null characters" |
| ).emit(); |
| } |
| codegen_fn_attrs.export_name = Some(s); |
| } else { |
| struct_span_err!( |
| tcx.sess, |
| attr.span, |
| E0558, |
| "`export_name` attribute has invalid format" |
| ).span_label(attr.span, "did you mean #[export_name=\"*\"]?") |
| .emit(); |
| } |
| } else if attr.check_name("target_feature") { |
| if tcx.fn_sig(id).unsafety() == Unsafety::Normal { |
| let msg = "#[target_feature(..)] can only be applied to \ |
| `unsafe` function"; |
| tcx.sess.span_err(attr.span, msg); |
| } |
| from_target_feature( |
| tcx, |
| id, |
| attr, |
| &whitelist, |
| &mut codegen_fn_attrs.target_features, |
| ); |
| } else if attr.check_name("linkage") { |
| if let Some(val) = attr.value_str() { |
| codegen_fn_attrs.linkage = Some(linkage_by_name(tcx, id, &val.as_str())); |
| } |
| } else if attr.check_name("link_section") { |
| if let Some(val) = attr.value_str() { |
| if val.as_str().bytes().any(|b| b == 0) { |
| let msg = format!( |
| "illegal null byte in link_section \ |
| value: `{}`", |
| &val |
| ); |
| tcx.sess.span_err(attr.span, &msg); |
| } else { |
| codegen_fn_attrs.link_section = Some(val); |
| } |
| } |
| } else if attr.check_name("link_name") { |
| codegen_fn_attrs.link_name = attr.value_str(); |
| } |
| } |
| |
| // If a function uses #[target_feature] it can't be inlined into general |
| // purpose functions as they wouldn't have the right target features |
| // enabled. For that reason we also forbid #[inline(always)] as it can't be |
| // respected. |
| if codegen_fn_attrs.target_features.len() > 0 { |
| if codegen_fn_attrs.inline == InlineAttr::Always { |
| if let Some(span) = inline_span { |
| tcx.sess.span_err( |
| span, |
| "cannot use #[inline(always)] with \ |
| #[target_feature]", |
| ); |
| } |
| } |
| } |
| |
| // Weak lang items have the same semantics as "std internal" symbols in the |
| // sense that they're preserved through all our LTO passes and only |
| // strippable by the linker. |
| // |
| // Additionally weak lang items have predetermined symbol names. |
| if tcx.is_weak_lang_item(id) { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL; |
| } |
| if let Some(name) = weak_lang_items::link_name(&attrs) { |
| codegen_fn_attrs.export_name = Some(name); |
| codegen_fn_attrs.link_name = Some(name); |
| } |
| |
| // Internal symbols to the standard library all have no_mangle semantics in |
| // that they have defined symbol names present in the function name. This |
| // also applies to weak symbols where they all have known symbol names. |
| if codegen_fn_attrs.flags.contains(CodegenFnAttrFlags::RUSTC_STD_INTERNAL_SYMBOL) { |
| codegen_fn_attrs.flags |= CodegenFnAttrFlags::NO_MANGLE; |
| } |
| |
| codegen_fn_attrs |
| } |