1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! "Collection" is the process of determining the type and other external
12 //! details of each item in Rust. Collection is specifically concerned
13 //! with *interprocedural* things -- for example, for a function
14 //! definition, collection will figure out the type and signature of the
15 //! function, but it will not visit the *body* of the function in any way,
16 //! nor examine type annotations on local variables (that's the job of
19 //! Collecting is ultimately defined by a bundle of queries that
20 //! inquire after various facts about the items in the crate (e.g.,
21 //! `type_of`, `generics_of`, `predicates_of`, etc). See the `provide` function
24 //! At present, however, we do run collection across all items in the
25 //! crate as a kind of pass. This should eventually be factored away.
27 use astconv::{AstConv, Bounds};
29 use constrained_type_params as ctp;
30 use middle::lang_items::SizedTraitLangItem;
31 use middle::const_val::ConstVal;
32 use middle::resolve_lifetime as rl;
33 use rustc::traits::Reveal;
34 use rustc::ty::subst::Substs;
35 use rustc::ty::{ToPredicate, ReprOptions};
36 use rustc::ty::{self, AdtKind, ToPolyTraitRef, Ty, TyCtxt};
37 use rustc::ty::maps::Providers;
38 use rustc::ty::util::IntTypeExt;
39 use util::nodemap::FxHashMap;
41 use rustc_const_math::ConstInt;
43 use std::collections::BTreeMap;
45 use syntax::{abi, ast};
46 use syntax::codemap::Spanned;
47 use syntax::symbol::{Symbol, keywords};
48 use syntax_pos::{Span, DUMMY_SP};
50 use rustc::hir::{self, map as hir_map};
51 use rustc::hir::intravisit::{self, Visitor, NestedVisitorMap};
52 use rustc::hir::def::{Def, CtorKind};
53 use rustc::hir::def_id::DefId;
55 ///////////////////////////////////////////////////////////////////////////
58 pub fn collect_item_types<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
59 let mut visitor = CollectItemTypesVisitor { tcx: tcx };
60 tcx.hir.krate().visit_all_item_likes(&mut visitor.as_deep_visitor());
63 pub fn provide(providers: &mut Providers) {
64 *providers = Providers {
69 type_param_predicates,
81 ///////////////////////////////////////////////////////////////////////////
83 /// Context specific to some particular item. This is what implements
84 /// AstConv. It has information about the predicates that are defined
85 /// on the trait. Unfortunately, this predicate information is
86 /// available in various different forms at various points in the
87 /// process. So we can't just store a pointer to e.g. the AST or the
88 /// parsed ty form, we have to be more flexible. To this end, the
89 /// `ItemCtxt` is parameterized by a `DefId` that it uses to satisfy
90 /// `get_type_parameter_bounds` requests, drawing the information from
91 /// the AST (`hir::Generics`), recursively.
92 pub struct ItemCtxt<'a,'tcx:'a> {
93 tcx: TyCtxt<'a, 'tcx, 'tcx>,
97 ///////////////////////////////////////////////////////////////////////////
99 struct CollectItemTypesVisitor<'a, 'tcx: 'a> {
100 tcx: TyCtxt<'a, 'tcx, 'tcx>
103 impl<'a, 'tcx> Visitor<'tcx> for CollectItemTypesVisitor<'a, 'tcx> {
104 fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
105 NestedVisitorMap::OnlyBodies(&self.tcx.hir)
108 fn visit_item(&mut self, item: &'tcx hir::Item) {
109 convert_item(self.tcx, item.id);
110 intravisit::walk_item(self, item);
113 fn visit_generics(&mut self, generics: &'tcx hir::Generics) {
114 for param in &generics.ty_params {
115 if param.default.is_some() {
116 let def_id = self.tcx.hir.local_def_id(param.id);
117 self.tcx.type_of(def_id);
120 intravisit::walk_generics(self, generics);
123 fn visit_expr(&mut self, expr: &'tcx hir::Expr) {
124 if let hir::ExprClosure(..) = expr.node {
125 let def_id = self.tcx.hir.local_def_id(expr.id);
126 self.tcx.generics_of(def_id);
127 self.tcx.type_of(def_id);
129 intravisit::walk_expr(self, expr);
132 fn visit_ty(&mut self, ty: &'tcx hir::Ty) {
133 if let hir::TyImplTrait(..) = ty.node {
134 let def_id = self.tcx.hir.local_def_id(ty.id);
135 self.tcx.generics_of(def_id);
136 self.tcx.predicates_of(def_id);
138 intravisit::walk_ty(self, ty);
141 fn visit_trait_item(&mut self, trait_item: &'tcx hir::TraitItem) {
142 convert_trait_item(self.tcx, trait_item.id);
143 intravisit::walk_trait_item(self, trait_item);
146 fn visit_impl_item(&mut self, impl_item: &'tcx hir::ImplItem) {
147 convert_impl_item(self.tcx, impl_item.id);
148 intravisit::walk_impl_item(self, impl_item);
152 ///////////////////////////////////////////////////////////////////////////
153 // Utility types and common code for the above passes.
155 impl<'a, 'tcx> ItemCtxt<'a, 'tcx> {
156 pub fn new(tcx: TyCtxt<'a, 'tcx, 'tcx>, item_def_id: DefId)
157 -> ItemCtxt<'a,'tcx> {
165 impl<'a,'tcx> ItemCtxt<'a,'tcx> {
166 pub fn to_ty(&self, ast_ty: &hir::Ty) -> Ty<'tcx> {
167 AstConv::ast_ty_to_ty(self, ast_ty)
171 impl<'a, 'tcx> AstConv<'tcx, 'tcx> for ItemCtxt<'a, 'tcx> {
172 fn tcx<'b>(&'b self) -> TyCtxt<'b, 'tcx, 'tcx> { self.tcx }
174 fn get_type_parameter_bounds(&self,
177 -> ty::GenericPredicates<'tcx>
179 self.tcx.at(span).type_param_predicates((self.item_def_id, def_id))
182 fn re_infer(&self, _span: Span, _def: Option<&ty::RegionParameterDef>)
183 -> Option<ty::Region<'tcx>> {
187 fn ty_infer(&self, span: Span) -> Ty<'tcx> {
192 "the type placeholder `_` is not allowed within types on item signatures"
193 ).span_label(span, "not allowed in type signatures")
198 fn projected_ty_from_poly_trait_ref(&self,
201 poly_trait_ref: ty::PolyTraitRef<'tcx>)
204 if let Some(trait_ref) = self.tcx().no_late_bound_regions(&poly_trait_ref) {
205 self.tcx().mk_projection(item_def_id, trait_ref.substs)
207 // no late-bound regions, we can just ignore the binder
208 span_err!(self.tcx().sess, span, E0212,
209 "cannot extract an associated type from a higher-ranked trait bound \
215 fn normalize_ty(&self, _span: Span, ty: Ty<'tcx>) -> Ty<'tcx> {
216 // types in item signatures are not normalized, to avoid undue
221 fn set_tainted_by_errors(&self) {
222 // no obvious place to track this, just let it go
226 fn type_param_predicates<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
227 (item_def_id, def_id): (DefId, DefId))
228 -> ty::GenericPredicates<'tcx> {
229 use rustc::hir::map::*;
232 // In the AST, bounds can derive from two places. Either
233 // written inline like `<T:Foo>` or in a where clause like
236 let param_id = tcx.hir.as_local_node_id(def_id).unwrap();
237 let param_owner = tcx.hir.ty_param_owner(param_id);
238 let param_owner_def_id = tcx.hir.local_def_id(param_owner);
239 let generics = tcx.generics_of(param_owner_def_id);
240 let index = generics.type_param_to_index[&def_id.index];
241 let ty = tcx.mk_param(index, tcx.hir.ty_param_name(param_id));
243 // Don't look for bounds where the type parameter isn't in scope.
244 let parent = if item_def_id == param_owner_def_id {
247 tcx.generics_of(item_def_id).parent
250 let mut result = parent.map_or(ty::GenericPredicates {
254 let icx = ItemCtxt::new(tcx, parent);
255 icx.get_type_parameter_bounds(DUMMY_SP, def_id)
258 let item_node_id = tcx.hir.as_local_node_id(item_def_id).unwrap();
259 let ast_generics = match tcx.hir.get(item_node_id) {
260 NodeTraitItem(item) => {
262 TraitItemKind::Method(ref sig, _) => &sig.generics,
267 NodeImplItem(item) => {
269 ImplItemKind::Method(ref sig, _) => &sig.generics,
276 ItemFn(.., ref generics, _) |
277 ItemImpl(_, _, _, ref generics, ..) |
278 ItemTy(_, ref generics) |
279 ItemEnum(_, ref generics) |
280 ItemStruct(_, ref generics) |
281 ItemUnion(_, ref generics) => generics,
282 ItemTrait(_, ref generics, ..) => {
283 // Implied `Self: Trait` and supertrait bounds.
284 if param_id == item_node_id {
285 result.predicates.push(ty::TraitRef {
287 substs: Substs::identity_for_item(tcx, item_def_id)
296 NodeForeignItem(item) => {
298 ForeignItemFn(_, _, ref generics) => generics,
306 let icx = ItemCtxt::new(tcx, item_def_id);
307 result.predicates.extend(
308 icx.type_parameter_bounds_in_generics(ast_generics, param_id, ty));
312 impl<'a, 'tcx> ItemCtxt<'a, 'tcx> {
313 /// Find bounds from hir::Generics. This requires scanning through the
314 /// AST. We do this to avoid having to convert *all* the bounds, which
315 /// would create artificial cycles. Instead we can only convert the
316 /// bounds for a type parameter `X` if `X::Foo` is used.
317 fn type_parameter_bounds_in_generics(&self,
318 ast_generics: &hir::Generics,
319 param_id: ast::NodeId,
321 -> Vec<ty::Predicate<'tcx>>
324 ast_generics.ty_params
326 .filter(|p| p.id == param_id)
327 .flat_map(|p| p.bounds.iter())
328 .flat_map(|b| predicates_from_bound(self, ty, b));
330 let from_where_clauses =
331 ast_generics.where_clause
334 .filter_map(|wp| match *wp {
335 hir::WherePredicate::BoundPredicate(ref bp) => Some(bp),
338 .filter(|bp| is_param(self.tcx, &bp.bounded_ty, param_id))
339 .flat_map(|bp| bp.bounds.iter())
340 .flat_map(|b| predicates_from_bound(self, ty, b));
342 from_ty_params.chain(from_where_clauses).collect()
346 /// Tests whether this is the AST for a reference to the type
347 /// parameter with id `param_id`. We use this so as to avoid running
348 /// `ast_ty_to_ty`, because we want to avoid triggering an all-out
349 /// conversion of the type to avoid inducing unnecessary cycles.
350 fn is_param<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
352 param_id: ast::NodeId)
355 if let hir::TyPath(hir::QPath::Resolved(None, ref path)) = ast_ty.node {
357 Def::SelfTy(Some(def_id), None) |
358 Def::TyParam(def_id) => {
359 def_id == tcx.hir.local_def_id(param_id)
368 fn ensure_no_ty_param_bounds(tcx: TyCtxt,
370 generics: &hir::Generics,
371 thing: &'static str) {
372 let mut warn = false;
374 for ty_param in generics.ty_params.iter() {
375 for bound in ty_param.bounds.iter() {
377 hir::TraitTyParamBound(..) => {
380 hir::RegionTyParamBound(..) => { }
385 for predicate in generics.where_clause.predicates.iter() {
387 hir::WherePredicate::BoundPredicate(..) => {
390 hir::WherePredicate::RegionPredicate(..) => { }
391 hir::WherePredicate::EqPredicate(..) => { }
396 // According to accepted RFC #XXX, we should
397 // eventually accept these, but it will not be
398 // part of this PR. Still, convert to warning to
399 // make bootstrapping easier.
400 span_warn!(tcx.sess, span, E0122,
401 "trait bounds are not (yet) enforced \
407 fn convert_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, item_id: ast::NodeId) {
408 let it = tcx.hir.expect_item(item_id);
409 debug!("convert: item {} with id {}", it.name, it.id);
410 let def_id = tcx.hir.local_def_id(item_id);
412 // These don't define types.
413 hir::ItemExternCrate(_) |
416 hir::ItemGlobalAsm(_) => {}
417 hir::ItemForeignMod(ref foreign_mod) => {
418 for item in &foreign_mod.items {
419 let def_id = tcx.hir.local_def_id(item.id);
420 tcx.generics_of(def_id);
422 tcx.predicates_of(def_id);
423 if let hir::ForeignItemFn(..) = item.node {
428 hir::ItemEnum(ref enum_definition, _) => {
429 tcx.generics_of(def_id);
431 tcx.predicates_of(def_id);
432 convert_enum_variant_types(tcx, def_id, &enum_definition.variants);
434 hir::ItemDefaultImpl(..) => {
435 tcx.impl_trait_ref(def_id);
437 hir::ItemImpl(..) => {
438 tcx.generics_of(def_id);
440 tcx.impl_trait_ref(def_id);
441 tcx.predicates_of(def_id);
443 hir::ItemTrait(..) => {
444 tcx.generics_of(def_id);
445 tcx.trait_def(def_id);
446 tcx.at(it.span).super_predicates_of(def_id);
447 tcx.predicates_of(def_id);
449 hir::ItemStruct(ref struct_def, _) |
450 hir::ItemUnion(ref struct_def, _) => {
451 tcx.generics_of(def_id);
453 tcx.predicates_of(def_id);
455 for f in struct_def.fields() {
456 let def_id = tcx.hir.local_def_id(f.id);
457 tcx.generics_of(def_id);
459 tcx.predicates_of(def_id);
462 if !struct_def.is_struct() {
463 convert_variant_ctor(tcx, struct_def.id());
466 hir::ItemTy(_, ref generics) => {
467 ensure_no_ty_param_bounds(tcx, it.span, generics, "type");
468 tcx.generics_of(def_id);
470 tcx.predicates_of(def_id);
472 hir::ItemStatic(..) | hir::ItemConst(..) | hir::ItemFn(..) => {
473 tcx.generics_of(def_id);
475 tcx.predicates_of(def_id);
476 if let hir::ItemFn(..) = it.node {
483 fn convert_trait_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, trait_item_id: ast::NodeId) {
484 let trait_item = tcx.hir.expect_trait_item(trait_item_id);
485 let def_id = tcx.hir.local_def_id(trait_item.id);
486 tcx.generics_of(def_id);
488 match trait_item.node {
489 hir::TraitItemKind::Const(..) |
490 hir::TraitItemKind::Type(_, Some(_)) |
491 hir::TraitItemKind::Method(..) => {
493 if let hir::TraitItemKind::Method(..) = trait_item.node {
498 hir::TraitItemKind::Type(_, None) => {}
501 tcx.predicates_of(def_id);
504 fn convert_impl_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, impl_item_id: ast::NodeId) {
505 let def_id = tcx.hir.local_def_id(impl_item_id);
506 tcx.generics_of(def_id);
508 tcx.predicates_of(def_id);
509 if let hir::ImplItemKind::Method(..) = tcx.hir.expect_impl_item(impl_item_id).node {
514 fn convert_variant_ctor<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
515 ctor_id: ast::NodeId) {
516 let def_id = tcx.hir.local_def_id(ctor_id);
517 tcx.generics_of(def_id);
519 tcx.predicates_of(def_id);
522 fn convert_enum_variant_types<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
524 variants: &[hir::Variant]) {
525 let param_env = ty::ParamEnv::empty(Reveal::UserFacing);
526 let def = tcx.adt_def(def_id);
527 let repr_type = def.repr.discr_type();
528 let initial = repr_type.initial_discriminant(tcx);
529 let mut prev_discr = None::<ConstInt>;
531 // fill the discriminant values and field types
532 for variant in variants {
533 let wrapped_discr = prev_discr.map_or(initial, |d| d.wrap_incr());
534 prev_discr = Some(if let Some(e) = variant.node.disr_expr {
535 let expr_did = tcx.hir.local_def_id(e.node_id);
536 let substs = Substs::identity_for_item(tcx, expr_did);
537 let result = tcx.at(variant.span).const_eval(param_env.and((expr_did, substs)));
539 // enum variant evaluation happens before the global constant check
540 // so we need to report the real error
541 if let Err(ref err) = result {
542 err.report(tcx, variant.span, "enum discriminant");
546 Ok(&ty::Const { val: ConstVal::Integral(x), .. }) => Some(x),
549 } else if let Some(discr) = repr_type.disr_incr(tcx, prev_discr) {
552 struct_span_err!(tcx.sess, variant.span, E0370,
553 "enum discriminant overflowed")
554 .span_label(variant.span, format!("overflowed on value after {}",
555 prev_discr.unwrap()))
556 .note(&format!("explicitly set `{} = {}` if that is desired outcome",
557 variant.node.name, wrapped_discr))
560 }.unwrap_or(wrapped_discr));
562 for f in variant.node.data.fields() {
563 let def_id = tcx.hir.local_def_id(f.id);
564 tcx.generics_of(def_id);
566 tcx.predicates_of(def_id);
569 // Convert the ctor, if any. This also registers the variant as
571 convert_variant_ctor(tcx, variant.node.data.id());
575 fn convert_struct_variant<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
578 discr: ty::VariantDiscr,
579 def: &hir::VariantData)
581 let mut seen_fields: FxHashMap<ast::Name, Span> = FxHashMap();
582 let node_id = tcx.hir.as_local_node_id(did).unwrap();
583 let fields = def.fields().iter().map(|f| {
584 let fid = tcx.hir.local_def_id(f.id);
585 let dup_span = seen_fields.get(&f.name).cloned();
586 if let Some(prev_span) = dup_span {
587 struct_span_err!(tcx.sess, f.span, E0124,
588 "field `{}` is already declared",
590 .span_label(f.span, "field already declared")
591 .span_label(prev_span, format!("`{}` first declared here", f.name))
594 seen_fields.insert(f.name, f.span);
600 vis: ty::Visibility::from_hir(&f.vis, node_id, tcx)
608 ctor_kind: CtorKind::from_hir(def),
612 fn adt_def<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
614 -> &'tcx ty::AdtDef {
615 use rustc::hir::map::*;
618 let node_id = tcx.hir.as_local_node_id(def_id).unwrap();
619 let item = match tcx.hir.get(node_id) {
620 NodeItem(item) => item,
624 let repr = ReprOptions::new(tcx, def_id);
625 let (kind, variants) = match item.node {
626 ItemEnum(ref def, _) => {
627 let mut distance_from_explicit = 0;
628 (AdtKind::Enum, def.variants.iter().map(|v| {
629 let did = tcx.hir.local_def_id(v.node.data.id());
630 let discr = if let Some(e) = v.node.disr_expr {
631 distance_from_explicit = 0;
632 ty::VariantDiscr::Explicit(tcx.hir.local_def_id(e.node_id))
634 ty::VariantDiscr::Relative(distance_from_explicit)
636 distance_from_explicit += 1;
638 convert_struct_variant(tcx, did, v.node.name, discr, &v.node.data)
641 ItemStruct(ref def, _) => {
642 // Use separate constructor id for unit/tuple structs and reuse did for braced structs.
643 let ctor_id = if !def.is_struct() {
644 Some(tcx.hir.local_def_id(def.id()))
648 (AdtKind::Struct, vec![
649 convert_struct_variant(tcx, ctor_id.unwrap_or(def_id), item.name,
650 ty::VariantDiscr::Relative(0), def)
653 ItemUnion(ref def, _) => {
654 (AdtKind::Union, vec![
655 convert_struct_variant(tcx, def_id, item.name,
656 ty::VariantDiscr::Relative(0), def)
661 tcx.alloc_adt_def(def_id, kind, variants, repr)
664 /// Ensures that the super-predicates of the trait with def-id
665 /// trait_def_id are converted and stored. This also ensures that
666 /// the transitive super-predicates are converted;
667 fn super_predicates_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
669 -> ty::GenericPredicates<'tcx> {
670 debug!("super_predicates(trait_def_id={:?})", trait_def_id);
671 let trait_node_id = tcx.hir.as_local_node_id(trait_def_id).unwrap();
673 let item = match tcx.hir.get(trait_node_id) {
674 hir_map::NodeItem(item) => item,
675 _ => bug!("trait_node_id {} is not an item", trait_node_id)
678 let (generics, bounds) = match item.node {
679 hir::ItemTrait(_, ref generics, ref supertraits, _) => (generics, supertraits),
680 _ => span_bug!(item.span,
681 "super_predicates invoked on non-trait"),
684 let icx = ItemCtxt::new(tcx, trait_def_id);
686 // Convert the bounds that follow the colon, e.g. `Bar+Zed` in `trait Foo : Bar+Zed`.
687 let self_param_ty = tcx.mk_self_type();
688 let superbounds1 = compute_bounds(&icx,
694 let superbounds1 = superbounds1.predicates(tcx, self_param_ty);
696 // Convert any explicit superbounds in the where clause,
697 // e.g. `trait Foo where Self : Bar`:
698 let superbounds2 = icx.type_parameter_bounds_in_generics(generics, item.id, self_param_ty);
700 // Combine the two lists to form the complete set of superbounds:
701 let superbounds: Vec<_> = superbounds1.into_iter().chain(superbounds2).collect();
703 // Now require that immediate supertraits are converted,
704 // which will, in turn, reach indirect supertraits.
705 for bound in superbounds.iter().filter_map(|p| p.to_opt_poly_trait_ref()) {
706 tcx.at(item.span).super_predicates_of(bound.def_id());
709 ty::GenericPredicates {
711 predicates: superbounds
715 fn trait_def<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
717 -> &'tcx ty::TraitDef {
718 let node_id = tcx.hir.as_local_node_id(def_id).unwrap();
719 let item = tcx.hir.expect_item(node_id);
721 let unsafety = match item.node {
722 hir::ItemTrait(unsafety, ..) => unsafety,
723 _ => span_bug!(item.span, "trait_def_of_item invoked on non-trait"),
726 let paren_sugar = tcx.has_attr(def_id, "rustc_paren_sugar");
727 if paren_sugar && !tcx.sess.features.borrow().unboxed_closures {
728 let mut err = tcx.sess.struct_span_err(
730 "the `#[rustc_paren_sugar]` attribute is a temporary means of controlling \
731 which traits can use parenthetical notation");
733 "add `#![feature(unboxed_closures)]` to \
734 the crate attributes to use it");
738 let def_path_hash = tcx.def_path_hash(def_id);
739 let has_default_impl = tcx.hir.trait_is_auto(def_id);
740 let def = ty::TraitDef::new(def_id,
745 tcx.alloc_trait_def(def)
748 fn has_late_bound_regions<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
749 node: hir_map::Node<'tcx>)
751 struct LateBoundRegionsDetector<'a, 'tcx: 'a> {
752 tcx: TyCtxt<'a, 'tcx, 'tcx>,
754 has_late_bound_regions: Option<Span>,
757 impl<'a, 'tcx> Visitor<'tcx> for LateBoundRegionsDetector<'a, 'tcx> {
758 fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
759 NestedVisitorMap::None
762 fn visit_ty(&mut self, ty: &'tcx hir::Ty) {
763 if self.has_late_bound_regions.is_some() { return }
765 hir::TyBareFn(..) => {
766 self.binder_depth += 1;
767 intravisit::walk_ty(self, ty);
768 self.binder_depth -= 1;
770 _ => intravisit::walk_ty(self, ty)
774 fn visit_poly_trait_ref(&mut self,
775 tr: &'tcx hir::PolyTraitRef,
776 m: hir::TraitBoundModifier) {
777 if self.has_late_bound_regions.is_some() { return }
778 self.binder_depth += 1;
779 intravisit::walk_poly_trait_ref(self, tr, m);
780 self.binder_depth -= 1;
783 fn visit_lifetime(&mut self, lt: &'tcx hir::Lifetime) {
784 if self.has_late_bound_regions.is_some() { return }
786 let hir_id = self.tcx.hir.node_to_hir_id(lt.id);
787 match self.tcx.named_region(hir_id) {
788 Some(rl::Region::Static) | Some(rl::Region::EarlyBound(..)) => {}
789 Some(rl::Region::LateBound(debruijn, _)) |
790 Some(rl::Region::LateBoundAnon(debruijn, _))
791 if debruijn.depth < self.binder_depth => {}
792 _ => self.has_late_bound_regions = Some(lt.span),
797 fn has_late_bound_regions<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
798 generics: &'tcx hir::Generics,
799 decl: &'tcx hir::FnDecl)
801 let mut visitor = LateBoundRegionsDetector {
802 tcx, binder_depth: 1, has_late_bound_regions: None
804 for lifetime in &generics.lifetimes {
805 let hir_id = tcx.hir.node_to_hir_id(lifetime.lifetime.id);
806 if tcx.is_late_bound(hir_id) {
807 return Some(lifetime.lifetime.span);
810 visitor.visit_fn_decl(decl);
811 visitor.has_late_bound_regions
815 hir_map::NodeTraitItem(item) => match item.node {
816 hir::TraitItemKind::Method(ref sig, _) =>
817 has_late_bound_regions(tcx, &sig.generics, &sig.decl),
820 hir_map::NodeImplItem(item) => match item.node {
821 hir::ImplItemKind::Method(ref sig, _) =>
822 has_late_bound_regions(tcx, &sig.generics, &sig.decl),
825 hir_map::NodeForeignItem(item) => match item.node {
826 hir::ForeignItemFn(ref fn_decl, _, ref generics) =>
827 has_late_bound_regions(tcx, generics, fn_decl),
830 hir_map::NodeItem(item) => match item.node {
831 hir::ItemFn(ref fn_decl, .., ref generics, _) =>
832 has_late_bound_regions(tcx, generics, fn_decl),
839 fn generics_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
841 -> &'tcx ty::Generics {
842 use rustc::hir::map::*;
845 let node_id = tcx.hir.as_local_node_id(def_id).unwrap();
847 let node = tcx.hir.get(node_id);
848 let parent_def_id = match node {
854 let parent_id = tcx.hir.get_parent(node_id);
855 Some(tcx.hir.local_def_id(parent_id))
857 NodeExpr(&hir::Expr { node: hir::ExprClosure(..), .. }) => {
858 Some(tcx.closure_base_def_id(def_id))
860 NodeTy(&hir::Ty { node: hir::TyImplTrait(..), .. }) => {
861 let mut parent_id = node_id;
863 match tcx.hir.get(parent_id) {
864 NodeItem(_) | NodeImplItem(_) | NodeTraitItem(_) => break,
866 parent_id = tcx.hir.get_parent_node(parent_id);
870 Some(tcx.hir.local_def_id(parent_id))
875 let mut opt_self = None;
876 let mut allow_defaults = false;
878 let no_generics = hir::Generics::empty();
879 let ast_generics = match node {
880 NodeTraitItem(item) => {
882 TraitItemKind::Method(ref sig, _) => &sig.generics,
887 NodeImplItem(item) => {
889 ImplItemKind::Method(ref sig, _) => &sig.generics,
896 ItemFn(.., ref generics, _) |
897 ItemImpl(_, _, _, ref generics, ..) => generics,
899 ItemTy(_, ref generics) |
900 ItemEnum(_, ref generics) |
901 ItemStruct(_, ref generics) |
902 ItemUnion(_, ref generics) => {
903 allow_defaults = true;
907 ItemTrait(_, ref generics, ..) => {
908 // Add in the self type parameter.
910 // Something of a hack: use the node id for the trait, also as
911 // the node id for the Self type parameter.
912 let param_id = item.id;
914 opt_self = Some(ty::TypeParameterDef {
916 name: keywords::SelfType.name(),
917 def_id: tcx.hir.local_def_id(param_id),
919 object_lifetime_default: rl::Set1::Empty,
920 pure_wrt_drop: false,
923 allow_defaults = true;
931 NodeForeignItem(item) => {
933 ForeignItemStatic(..) => &no_generics,
934 ForeignItemFn(_, _, ref generics) => generics
941 let has_self = opt_self.is_some();
942 let mut parent_has_self = false;
943 let mut own_start = has_self as u32;
944 let (parent_regions, parent_types) = parent_def_id.map_or((0, 0), |def_id| {
945 let generics = tcx.generics_of(def_id);
946 assert_eq!(has_self, false);
947 parent_has_self = generics.has_self;
948 own_start = generics.count() as u32;
949 (generics.parent_regions + generics.regions.len() as u32,
950 generics.parent_types + generics.types.len() as u32)
953 let early_lifetimes = early_bound_lifetimes_from_generics(tcx, ast_generics);
954 let regions = early_lifetimes.enumerate().map(|(i, l)| {
955 ty::RegionParameterDef {
956 name: l.lifetime.name.name(),
957 index: own_start + i as u32,
958 def_id: tcx.hir.local_def_id(l.lifetime.id),
959 pure_wrt_drop: l.pure_wrt_drop,
961 }).collect::<Vec<_>>();
963 let hir_id = tcx.hir.node_to_hir_id(node_id);
964 let object_lifetime_defaults = tcx.object_lifetime_defaults(hir_id);
966 // Now create the real type parameters.
967 let type_start = own_start + regions.len() as u32;
968 let types = ast_generics.ty_params.iter().enumerate().map(|(i, p)| {
969 if p.name == keywords::SelfType.name() {
970 span_bug!(p.span, "`Self` should not be the name of a regular parameter");
973 if !allow_defaults && p.default.is_some() {
974 if !tcx.sess.features.borrow().default_type_parameter_fallback {
976 lint::builtin::INVALID_TYPE_PARAM_DEFAULT,
979 &format!("defaults for type parameters are only allowed in `struct`, \
980 `enum`, `type`, or `trait` definitions."));
984 ty::TypeParameterDef {
985 index: type_start + i as u32,
987 def_id: tcx.hir.local_def_id(p.id),
988 has_default: p.default.is_some(),
989 object_lifetime_default:
990 object_lifetime_defaults.as_ref().map_or(rl::Set1::Empty, |o| o[i]),
991 pure_wrt_drop: p.pure_wrt_drop,
994 let mut types: Vec<_> = opt_self.into_iter().chain(types).collect();
996 // provide junk type parameter defs - the only place that
997 // cares about anything but the length is instantiation,
998 // and we don't do that for closures.
999 if let NodeExpr(&hir::Expr { node: hir::ExprClosure(..), .. }) = node {
1000 tcx.with_freevars(node_id, |fv| {
1001 types.extend(fv.iter().enumerate().map(|(i, _)| ty::TypeParameterDef {
1002 index: type_start + i as u32,
1003 name: Symbol::intern("<upvar>"),
1006 object_lifetime_default: rl::Set1::Empty,
1007 pure_wrt_drop: false,
1012 let mut type_param_to_index = BTreeMap::new();
1013 for param in &types {
1014 type_param_to_index.insert(param.def_id.index, param.index);
1017 tcx.alloc_generics(ty::Generics {
1018 parent: parent_def_id,
1023 type_param_to_index,
1024 has_self: has_self || parent_has_self,
1025 has_late_bound_regions: has_late_bound_regions(tcx, node),
1029 fn type_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
1032 use rustc::hir::map::*;
1035 let node_id = tcx.hir.as_local_node_id(def_id).unwrap();
1037 let icx = ItemCtxt::new(tcx, def_id);
1039 match tcx.hir.get(node_id) {
1040 NodeTraitItem(item) => {
1042 TraitItemKind::Method(..) => {
1043 let substs = Substs::identity_for_item(tcx, def_id);
1044 tcx.mk_fn_def(def_id, substs)
1046 TraitItemKind::Const(ref ty, _) |
1047 TraitItemKind::Type(_, Some(ref ty)) => icx.to_ty(ty),
1048 TraitItemKind::Type(_, None) => {
1049 span_bug!(item.span, "associated type missing default");
1054 NodeImplItem(item) => {
1056 ImplItemKind::Method(..) => {
1057 let substs = Substs::identity_for_item(tcx, def_id);
1058 tcx.mk_fn_def(def_id, substs)
1060 ImplItemKind::Const(ref ty, _) => icx.to_ty(ty),
1061 ImplItemKind::Type(ref ty) => {
1062 if tcx.impl_trait_ref(tcx.hir.get_parent_did(node_id)).is_none() {
1063 span_err!(tcx.sess, item.span, E0202,
1064 "associated types are not allowed in inherent impls");
1074 ItemStatic(ref t, ..) | ItemConst(ref t, _) |
1075 ItemTy(ref t, _) | ItemImpl(.., ref t, _) => {
1079 let substs = Substs::identity_for_item(tcx, def_id);
1080 tcx.mk_fn_def(def_id, substs)
1085 let def = tcx.adt_def(def_id);
1086 let substs = Substs::identity_for_item(tcx, def_id);
1087 tcx.mk_adt(def, substs)
1089 ItemDefaultImpl(..) |
1092 ItemForeignMod(..) |
1094 ItemExternCrate(..) |
1098 "compute_type_of_item: unexpected item type: {:?}",
1104 NodeForeignItem(foreign_item) => {
1105 match foreign_item.node {
1106 ForeignItemFn(..) => {
1107 let substs = Substs::identity_for_item(tcx, def_id);
1108 tcx.mk_fn_def(def_id, substs)
1110 ForeignItemStatic(ref t, _) => icx.to_ty(t)
1114 NodeStructCtor(&ref def) |
1115 NodeVariant(&Spanned { node: hir::Variant_ { data: ref def, .. }, .. }) => {
1117 VariantData::Unit(..) | VariantData::Struct(..) => {
1118 tcx.type_of(tcx.hir.get_parent_did(node_id))
1120 VariantData::Tuple(..) => {
1121 let substs = Substs::identity_for_item(tcx, def_id);
1122 tcx.mk_fn_def(def_id, substs)
1127 NodeField(field) => icx.to_ty(&field.ty),
1129 NodeExpr(&hir::Expr { node: hir::ExprClosure(.., is_generator), .. }) => {
1131 let hir_id = tcx.hir.node_to_hir_id(node_id);
1132 return tcx.typeck_tables_of(def_id).node_id_to_type(hir_id);
1135 tcx.mk_closure(def_id, Substs::for_item(
1138 let region = def.to_early_bound_region_data();
1139 tcx.mk_region(ty::ReEarlyBound(region))
1141 |def, _| tcx.mk_param_from_def(def)
1145 NodeExpr(_) => match tcx.hir.get(tcx.hir.get_parent_node(node_id)) {
1146 NodeTy(&hir::Ty { node: TyArray(_, body), .. }) |
1147 NodeTy(&hir::Ty { node: TyTypeof(body), .. }) |
1148 NodeExpr(&hir::Expr { node: ExprRepeat(_, body), .. })
1149 if body.node_id == node_id => tcx.types.usize,
1151 NodeVariant(&Spanned { node: Variant_ { disr_expr: Some(e), .. }, .. })
1152 if e.node_id == node_id => {
1153 tcx.adt_def(tcx.hir.get_parent_did(node_id))
1154 .repr.discr_type().to_ty(tcx)
1158 bug!("unexpected expr parent in type_of_def_id(): {:?}", x);
1162 NodeTyParam(&hir::TyParam { default: Some(ref ty), .. }) => {
1166 NodeTy(&hir::Ty { node: TyImplTrait(..), .. }) => {
1167 let owner = tcx.hir.get_parent_did(node_id);
1168 let hir_id = tcx.hir.node_to_hir_id(node_id);
1169 tcx.typeck_tables_of(owner).node_id_to_type(hir_id)
1173 bug!("unexpected sort of node in type_of_def_id(): {:?}", x);
1178 fn fn_sig<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
1180 -> ty::PolyFnSig<'tcx> {
1181 use rustc::hir::map::*;
1184 let node_id = tcx.hir.as_local_node_id(def_id).unwrap();
1186 let icx = ItemCtxt::new(tcx, def_id);
1188 match tcx.hir.get(node_id) {
1189 NodeTraitItem(&hir::TraitItem { node: TraitItemKind::Method(ref sig, _), .. }) |
1190 NodeImplItem(&hir::ImplItem { node: ImplItemKind::Method(ref sig, _), .. }) => {
1191 AstConv::ty_of_fn(&icx, sig.unsafety, sig.abi, &sig.decl)
1194 NodeItem(&hir::Item { node: ItemFn(ref decl, unsafety, _, abi, _, _), .. }) => {
1195 AstConv::ty_of_fn(&icx, unsafety, abi, decl)
1198 NodeForeignItem(&hir::ForeignItem { node: ForeignItemFn(ref fn_decl, _, _), .. }) => {
1199 let abi = tcx.hir.get_foreign_abi(node_id);
1200 compute_sig_of_foreign_fn_decl(tcx, def_id, fn_decl, abi)
1203 NodeStructCtor(&VariantData::Tuple(ref fields, _)) |
1204 NodeVariant(&Spanned { node: hir::Variant_ {
1205 data: VariantData::Tuple(ref fields, _), ..
1207 let ty = tcx.type_of(tcx.hir.get_parent_did(node_id));
1208 let inputs = fields.iter().map(|f| {
1209 tcx.type_of(tcx.hir.local_def_id(f.id))
1211 ty::Binder(tcx.mk_fn_sig(
1215 hir::Unsafety::Normal,
1220 NodeExpr(&hir::Expr { node: hir::ExprClosure(..), hir_id, .. }) => {
1221 tcx.typeck_tables_of(def_id).closure_tys()[hir_id]
1225 bug!("unexpected sort of node in fn_sig(): {:?}", x);
1230 fn impl_trait_ref<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
1232 -> Option<ty::TraitRef<'tcx>> {
1233 let icx = ItemCtxt::new(tcx, def_id);
1235 let node_id = tcx.hir.as_local_node_id(def_id).unwrap();
1236 match tcx.hir.expect_item(node_id).node {
1237 hir::ItemDefaultImpl(_, ref ast_trait_ref) => {
1238 Some(AstConv::instantiate_mono_trait_ref(&icx,
1240 tcx.mk_self_type()))
1242 hir::ItemImpl(.., ref opt_trait_ref, _, _) => {
1243 opt_trait_ref.as_ref().map(|ast_trait_ref| {
1244 let selfty = tcx.type_of(def_id);
1245 AstConv::instantiate_mono_trait_ref(&icx, ast_trait_ref, selfty)
1252 fn impl_polarity<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
1254 -> hir::ImplPolarity {
1255 let node_id = tcx.hir.as_local_node_id(def_id).unwrap();
1256 match tcx.hir.expect_item(node_id).node {
1257 hir::ItemImpl(_, polarity, ..) => polarity,
1258 ref item => bug!("impl_polarity: {:?} not an impl", item)
1262 // Is it marked with ?Sized
1263 fn is_unsized<'gcx: 'tcx, 'tcx>(astconv: &AstConv<'gcx, 'tcx>,
1264 ast_bounds: &[hir::TyParamBound],
1267 let tcx = astconv.tcx();
1269 // Try to find an unbound in bounds.
1270 let mut unbound = None;
1271 for ab in ast_bounds {
1272 if let &hir::TraitTyParamBound(ref ptr, hir::TraitBoundModifier::Maybe) = ab {
1273 if unbound.is_none() {
1274 unbound = Some(ptr.trait_ref.clone());
1276 span_err!(tcx.sess, span, E0203,
1277 "type parameter has more than one relaxed default \
1278 bound, only one is supported");
1283 let kind_id = tcx.lang_items().require(SizedTraitLangItem);
1286 // FIXME(#8559) currently requires the unbound to be built-in.
1287 if let Ok(kind_id) = kind_id {
1288 if tpb.path.def != Def::Trait(kind_id) {
1289 tcx.sess.span_warn(span,
1290 "default bound relaxed for a type parameter, but \
1291 this does nothing because the given bound is not \
1292 a default. Only `?Sized` is supported");
1296 _ if kind_id.is_ok() => {
1299 // No lang item for Sized, so we can't add it as a bound.
1306 /// Returns the early-bound lifetimes declared in this generics
1307 /// listing. For anything other than fns/methods, this is just all
1308 /// the lifetimes that are declared. For fns or methods, we have to
1309 /// screen out those that do not appear in any where-clauses etc using
1310 /// `resolve_lifetime::early_bound_lifetimes`.
1311 fn early_bound_lifetimes_from_generics<'a, 'tcx>(
1312 tcx: TyCtxt<'a, 'tcx, 'tcx>,
1313 ast_generics: &'a hir::Generics)
1314 -> impl Iterator<Item=&'a hir::LifetimeDef>
1320 let hir_id = tcx.hir.node_to_hir_id(l.lifetime.id);
1321 !tcx.is_late_bound(hir_id)
1325 fn predicates_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
1327 -> ty::GenericPredicates<'tcx> {
1328 use rustc::hir::map::*;
1331 let node_id = tcx.hir.as_local_node_id(def_id).unwrap();
1332 let node = tcx.hir.get(node_id);
1334 let mut is_trait = None;
1336 let icx = ItemCtxt::new(tcx, def_id);
1337 let no_generics = hir::Generics::empty();
1338 let ast_generics = match node {
1339 NodeTraitItem(item) => {
1341 TraitItemKind::Method(ref sig, _) => &sig.generics,
1346 NodeImplItem(item) => {
1348 ImplItemKind::Method(ref sig, _) => &sig.generics,
1355 ItemFn(.., ref generics, _) |
1356 ItemImpl(_, _, _, ref generics, ..) |
1357 ItemTy(_, ref generics) |
1358 ItemEnum(_, ref generics) |
1359 ItemStruct(_, ref generics) |
1360 ItemUnion(_, ref generics) => {
1364 ItemTrait(_, ref generics, .., ref items) => {
1365 is_trait = Some((ty::TraitRef {
1367 substs: Substs::identity_for_item(tcx, def_id)
1376 NodeForeignItem(item) => {
1378 ForeignItemStatic(..) => &no_generics,
1379 ForeignItemFn(_, _, ref generics) => generics
1383 NodeTy(&Ty { node: TyImplTrait(ref bounds), span, .. }) => {
1384 let substs = Substs::identity_for_item(tcx, def_id);
1385 let anon_ty = tcx.mk_anon(def_id, substs);
1387 // Collect the bounds, i.e. the `A+B+'c` in `impl A+B+'c`.
1388 let bounds = compute_bounds(&icx, anon_ty, bounds,
1389 SizedByDefault::Yes,
1391 return ty::GenericPredicates {
1393 predicates: bounds.predicates(tcx, anon_ty)
1400 let generics = tcx.generics_of(def_id);
1401 let parent_count = generics.parent_count() as u32;
1402 let has_own_self = generics.has_self && parent_count == 0;
1404 let mut predicates = vec![];
1406 // Below we'll consider the bounds on the type parameters (including `Self`)
1407 // and the explicit where-clauses, but to get the full set of predicates
1408 // on a trait we need to add in the supertrait bounds and bounds found on
1409 // associated types.
1410 if let Some((trait_ref, _)) = is_trait {
1411 predicates = tcx.super_predicates_of(def_id).predicates;
1413 // Add in a predicate that `Self:Trait` (where `Trait` is the
1414 // current trait). This is needed for builtin bounds.
1415 predicates.push(trait_ref.to_poly_trait_ref().to_predicate());
1418 // Collect the region predicates that were declared inline as
1419 // well. In the case of parameters declared on a fn or method, we
1420 // have to be careful to only iterate over early-bound regions.
1421 let mut index = parent_count + has_own_self as u32;
1422 for param in early_bound_lifetimes_from_generics(tcx, ast_generics) {
1423 let region = tcx.mk_region(ty::ReEarlyBound(ty::EarlyBoundRegion {
1424 def_id: tcx.hir.local_def_id(param.lifetime.id),
1426 name: param.lifetime.name.name(),
1430 for bound in ¶m.bounds {
1431 let bound_region = AstConv::ast_region_to_region(&icx, bound, None);
1432 let outlives = ty::Binder(ty::OutlivesPredicate(region, bound_region));
1433 predicates.push(outlives.to_predicate());
1437 // Collect the predicates that were written inline by the user on each
1438 // type parameter (e.g., `<T:Foo>`).
1439 for param in &ast_generics.ty_params {
1440 let param_ty = ty::ParamTy::new(index, param.name).to_ty(tcx);
1443 let bounds = compute_bounds(&icx,
1446 SizedByDefault::Yes,
1448 predicates.extend(bounds.predicates(tcx, param_ty));
1451 // Add in the bounds that appear in the where-clause
1452 let where_clause = &ast_generics.where_clause;
1453 for predicate in &where_clause.predicates {
1455 &hir::WherePredicate::BoundPredicate(ref bound_pred) => {
1456 let ty = icx.to_ty(&bound_pred.bounded_ty);
1458 for bound in bound_pred.bounds.iter() {
1460 &hir::TyParamBound::TraitTyParamBound(ref poly_trait_ref, _) => {
1461 let mut projections = Vec::new();
1464 AstConv::instantiate_poly_trait_ref(&icx,
1469 predicates.push(trait_ref.to_predicate());
1471 for projection in &projections {
1472 predicates.push(projection.to_predicate());
1476 &hir::TyParamBound::RegionTyParamBound(ref lifetime) => {
1477 let region = AstConv::ast_region_to_region(&icx,
1480 let pred = ty::Binder(ty::OutlivesPredicate(ty, region));
1481 predicates.push(ty::Predicate::TypeOutlives(pred))
1487 &hir::WherePredicate::RegionPredicate(ref region_pred) => {
1488 let r1 = AstConv::ast_region_to_region(&icx, ®ion_pred.lifetime, None);
1489 for bound in ®ion_pred.bounds {
1490 let r2 = AstConv::ast_region_to_region(&icx, bound, None);
1491 let pred = ty::Binder(ty::OutlivesPredicate(r1, r2));
1492 predicates.push(ty::Predicate::RegionOutlives(pred))
1496 &hir::WherePredicate::EqPredicate(..) => {
1502 // Add predicates from associated type bounds.
1503 if let Some((self_trait_ref, trait_items)) = is_trait {
1504 predicates.extend(trait_items.iter().flat_map(|trait_item_ref| {
1505 let trait_item = tcx.hir.trait_item(trait_item_ref.id);
1506 let bounds = match trait_item.node {
1507 hir::TraitItemKind::Type(ref bounds, _) => bounds,
1509 return vec![].into_iter();
1513 let assoc_ty = tcx.mk_projection(
1514 tcx.hir.local_def_id(trait_item.id),
1515 self_trait_ref.substs,
1518 let bounds = compute_bounds(&ItemCtxt::new(tcx, def_id),
1521 SizedByDefault::Yes,
1524 bounds.predicates(tcx, assoc_ty).into_iter()
1528 // Subtle: before we store the predicates into the tcx, we
1529 // sort them so that predicates like `T: Foo<Item=U>` come
1530 // before uses of `U`. This avoids false ambiguity errors
1531 // in trait checking. See `setup_constraining_predicates`
1533 if let NodeItem(&Item { node: ItemImpl(..), .. }) = node {
1534 let self_ty = tcx.type_of(def_id);
1535 let trait_ref = tcx.impl_trait_ref(def_id);
1536 ctp::setup_constraining_predicates(tcx,
1539 &mut ctp::parameters_for_impl(self_ty, trait_ref));
1542 ty::GenericPredicates {
1543 parent: generics.parent,
1548 pub enum SizedByDefault { Yes, No, }
1550 /// Translate the AST's notion of ty param bounds (which are an enum consisting of a newtyped Ty or
1551 /// a region) to ty's notion of ty param bounds, which can either be user-defined traits, or the
1552 /// built-in trait (formerly known as kind): Send.
1553 pub fn compute_bounds<'gcx: 'tcx, 'tcx>(astconv: &AstConv<'gcx, 'tcx>,
1555 ast_bounds: &[hir::TyParamBound],
1556 sized_by_default: SizedByDefault,
1560 let mut region_bounds = vec![];
1561 let mut trait_bounds = vec![];
1562 for ast_bound in ast_bounds {
1564 hir::TraitTyParamBound(ref b, hir::TraitBoundModifier::None) => {
1565 trait_bounds.push(b);
1567 hir::TraitTyParamBound(_, hir::TraitBoundModifier::Maybe) => {}
1568 hir::RegionTyParamBound(ref l) => {
1569 region_bounds.push(l);
1574 let mut projection_bounds = vec![];
1576 let mut trait_bounds: Vec<_> = trait_bounds.iter().map(|&bound| {
1577 astconv.instantiate_poly_trait_ref(bound,
1579 &mut projection_bounds)
1582 let region_bounds = region_bounds.into_iter().map(|r| {
1583 astconv.ast_region_to_region(r, None)
1586 trait_bounds.sort_by(|a,b| a.def_id().cmp(&b.def_id()));
1588 let implicitly_sized = if let SizedByDefault::Yes = sized_by_default {
1589 !is_unsized(astconv, ast_bounds, span)
1602 /// Converts a specific TyParamBound from the AST into a set of
1603 /// predicates that apply to the self-type. A vector is returned
1604 /// because this can be anywhere from 0 predicates (`T:?Sized` adds no
1605 /// predicates) to 1 (`T:Foo`) to many (`T:Bar<X=i32>` adds `T:Bar`
1606 /// and `<T as Bar>::X == i32`).
1607 fn predicates_from_bound<'tcx>(astconv: &AstConv<'tcx, 'tcx>,
1609 bound: &hir::TyParamBound)
1610 -> Vec<ty::Predicate<'tcx>>
1613 hir::TraitTyParamBound(ref tr, hir::TraitBoundModifier::None) => {
1614 let mut projections = Vec::new();
1615 let pred = astconv.instantiate_poly_trait_ref(tr,
1618 projections.into_iter()
1619 .map(|p| p.to_predicate())
1620 .chain(Some(pred.to_predicate()))
1623 hir::RegionTyParamBound(ref lifetime) => {
1624 let region = astconv.ast_region_to_region(lifetime, None);
1625 let pred = ty::Binder(ty::OutlivesPredicate(param_ty, region));
1626 vec![ty::Predicate::TypeOutlives(pred)]
1628 hir::TraitTyParamBound(_, hir::TraitBoundModifier::Maybe) => {
1634 fn compute_sig_of_foreign_fn_decl<'a, 'tcx>(
1635 tcx: TyCtxt<'a, 'tcx, 'tcx>,
1639 -> ty::PolyFnSig<'tcx>
1641 let fty = AstConv::ty_of_fn(&ItemCtxt::new(tcx, def_id), hir::Unsafety::Unsafe, abi, decl);
1643 // feature gate SIMD types in FFI, since I (huonw) am not sure the
1644 // ABIs are handled at all correctly.
1645 if abi != abi::Abi::RustIntrinsic && abi != abi::Abi::PlatformIntrinsic
1646 && !tcx.sess.features.borrow().simd_ffi {
1647 let check = |ast_ty: &hir::Ty, ty: Ty| {
1649 tcx.sess.struct_span_err(ast_ty.span,
1650 &format!("use of SIMD type `{}` in FFI is highly experimental and \
1651 may result in invalid code",
1652 tcx.hir.node_to_pretty_string(ast_ty.id)))
1653 .help("add #![feature(simd_ffi)] to the crate attributes to enable")
1657 for (input, ty) in decl.inputs.iter().zip(*fty.inputs().skip_binder()) {
1660 if let hir::Return(ref ty) = decl.output {
1661 check(&ty, *fty.output().skip_binder())
1668 fn is_foreign_item<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
1671 match tcx.hir.get_if_local(def_id) {
1672 Some(hir_map::NodeForeignItem(..)) => true,
1674 _ => bug!("is_foreign_item applied to non-local def-id {:?}", def_id)
1678 fn is_default_impl<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
1681 match tcx.hir.get_if_local(def_id) {
1682 Some(hir_map::NodeItem(&hir::Item { node: hir::ItemDefaultImpl(..), .. }))
1685 _ => bug!("is_default_impl applied to non-local def-id {:?}", def_id)