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 #![allow(non_camel_case_types)]
13 pub use self::terr_vstore_kind::*;
14 pub use self::type_err::*;
15 pub use self::BuiltinBound::*;
16 pub use self::InferTy::*;
17 pub use self::InferRegion::*;
18 pub use self::ImplOrTraitItemId::*;
19 pub use self::ClosureKind::*;
20 pub use self::ast_ty_to_ty_cache_entry::*;
21 pub use self::Variance::*;
22 pub use self::AutoAdjustment::*;
23 pub use self::Representability::*;
24 pub use self::UnsizeKind::*;
25 pub use self::AutoRef::*;
26 pub use self::ExprKind::*;
27 pub use self::DtorKind::*;
28 pub use self::ExplicitSelfCategory::*;
29 pub use self::FnOutput::*;
30 pub use self::Region::*;
31 pub use self::ImplOrTraitItemContainer::*;
32 pub use self::BorrowKind::*;
33 pub use self::ImplOrTraitItem::*;
34 pub use self::BoundRegion::*;
36 pub use self::IntVarValue::*;
37 pub use self::ExprAdjustment::*;
38 pub use self::vtable_origin::*;
39 pub use self::MethodOrigin::*;
40 pub use self::CopyImplementationError::*;
45 use metadata::csearch;
47 use middle::check_const;
48 use middle::const_eval;
49 use middle::def::{self, DefMap, ExportMap};
50 use middle::dependency_format;
51 use middle::lang_items::{FnTraitLangItem, FnMutTraitLangItem};
52 use middle::lang_items::{FnOnceTraitLangItem, TyDescStructLangItem};
53 use middle::mem_categorization as mc;
55 use middle::resolve_lifetime;
57 use middle::stability;
58 use middle::subst::{self, Subst, Substs, VecPerParamSpace};
61 use middle::ty_fold::{self, TypeFoldable, TypeFolder};
62 use middle::ty_walk::TypeWalker;
63 use util::ppaux::{note_and_explain_region, bound_region_ptr_to_string};
64 use util::ppaux::ty_to_string;
65 use util::ppaux::{Repr, UserString};
66 use util::common::{memoized, ErrorReported};
67 use util::nodemap::{NodeMap, NodeSet, DefIdMap, DefIdSet};
68 use util::nodemap::{FnvHashMap};
70 use arena::TypedArena;
71 use std::borrow::{BorrowFrom, Cow};
72 use std::cell::{Cell, RefCell};
75 use std::hash::{Hash, Writer, SipHasher, Hasher};
80 use collections::enum_set::{EnumSet, CLike};
81 use std::collections::{HashMap, HashSet};
83 use syntax::ast::{CrateNum, DefId, Ident, ItemTrait, LOCAL_CRATE};
84 use syntax::ast::{MutImmutable, MutMutable, Name, NamedField, NodeId};
85 use syntax::ast::{StmtExpr, StmtSemi, StructField, UnnamedField, Visibility};
86 use syntax::ast_util::{self, is_local, lit_is_str, local_def, PostExpansionMethod};
87 use syntax::attr::{self, AttrMetaMethods};
88 use syntax::codemap::Span;
89 use syntax::parse::token::{self, InternedString, special_idents};
90 use syntax::{ast, ast_map};
94 pub const INITIAL_DISCRIMINANT_VALUE: Disr = 0;
98 /// The complete set of all analyses described in this module. This is
99 /// produced by the driver and fed to trans and later passes.
100 pub struct CrateAnalysis<'tcx> {
101 pub export_map: ExportMap,
102 pub exported_items: middle::privacy::ExportedItems,
103 pub public_items: middle::privacy::PublicItems,
104 pub ty_cx: ty::ctxt<'tcx>,
105 pub reachable: NodeSet,
107 pub glob_map: Option<GlobMap>,
110 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
111 pub struct field<'tcx> {
116 #[derive(Clone, Copy, Debug)]
117 pub enum ImplOrTraitItemContainer {
118 TraitContainer(ast::DefId),
119 ImplContainer(ast::DefId),
122 impl ImplOrTraitItemContainer {
123 pub fn id(&self) -> ast::DefId {
125 TraitContainer(id) => id,
126 ImplContainer(id) => id,
131 #[derive(Clone, Debug)]
132 pub enum ImplOrTraitItem<'tcx> {
133 MethodTraitItem(Rc<Method<'tcx>>),
134 TypeTraitItem(Rc<AssociatedType>),
137 impl<'tcx> ImplOrTraitItem<'tcx> {
138 fn id(&self) -> ImplOrTraitItemId {
140 MethodTraitItem(ref method) => MethodTraitItemId(method.def_id),
141 TypeTraitItem(ref associated_type) => {
142 TypeTraitItemId(associated_type.def_id)
147 pub fn def_id(&self) -> ast::DefId {
149 MethodTraitItem(ref method) => method.def_id,
150 TypeTraitItem(ref associated_type) => associated_type.def_id,
154 pub fn name(&self) -> ast::Name {
156 MethodTraitItem(ref method) => method.name,
157 TypeTraitItem(ref associated_type) => associated_type.name,
161 pub fn container(&self) -> ImplOrTraitItemContainer {
163 MethodTraitItem(ref method) => method.container,
164 TypeTraitItem(ref associated_type) => associated_type.container,
168 pub fn as_opt_method(&self) -> Option<Rc<Method<'tcx>>> {
170 MethodTraitItem(ref m) => Some((*m).clone()),
171 TypeTraitItem(_) => None
176 #[derive(Clone, Copy, Debug)]
177 pub enum ImplOrTraitItemId {
178 MethodTraitItemId(ast::DefId),
179 TypeTraitItemId(ast::DefId),
182 impl ImplOrTraitItemId {
183 pub fn def_id(&self) -> ast::DefId {
185 MethodTraitItemId(def_id) => def_id,
186 TypeTraitItemId(def_id) => def_id,
191 #[derive(Clone, Debug)]
192 pub struct Method<'tcx> {
194 pub generics: Generics<'tcx>,
195 pub predicates: GenericPredicates<'tcx>,
196 pub fty: BareFnTy<'tcx>,
197 pub explicit_self: ExplicitSelfCategory,
198 pub vis: ast::Visibility,
199 pub def_id: ast::DefId,
200 pub container: ImplOrTraitItemContainer,
202 // If this method is provided, we need to know where it came from
203 pub provided_source: Option<ast::DefId>
206 impl<'tcx> Method<'tcx> {
207 pub fn new(name: ast::Name,
208 generics: ty::Generics<'tcx>,
209 predicates: GenericPredicates<'tcx>,
211 explicit_self: ExplicitSelfCategory,
212 vis: ast::Visibility,
214 container: ImplOrTraitItemContainer,
215 provided_source: Option<ast::DefId>)
220 predicates: predicates,
222 explicit_self: explicit_self,
225 container: container,
226 provided_source: provided_source
230 pub fn container_id(&self) -> ast::DefId {
231 match self.container {
232 TraitContainer(id) => id,
233 ImplContainer(id) => id,
238 #[derive(Clone, Copy, Debug)]
239 pub struct AssociatedType {
241 pub vis: ast::Visibility,
242 pub def_id: ast::DefId,
243 pub container: ImplOrTraitItemContainer,
246 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
247 pub struct mt<'tcx> {
249 pub mutbl: ast::Mutability,
252 #[derive(Clone, Copy, Debug)]
253 pub struct field_ty {
256 pub vis: ast::Visibility,
257 pub origin: ast::DefId, // The DefId of the struct in which the field is declared.
260 // Contains information needed to resolve types and (in the future) look up
261 // the types of AST nodes.
262 #[derive(Copy, PartialEq, Eq, Hash)]
263 pub struct creader_cache_key {
270 pub enum ast_ty_to_ty_cache_entry<'tcx> {
271 atttce_unresolved, /* not resolved yet */
272 atttce_resolved(Ty<'tcx>) /* resolved to a type, irrespective of region */
275 #[derive(Clone, PartialEq, RustcDecodable, RustcEncodable)]
276 pub struct ItemVariances {
277 pub types: VecPerParamSpace<Variance>,
278 pub regions: VecPerParamSpace<Variance>,
281 #[derive(Clone, PartialEq, RustcDecodable, RustcEncodable, Debug, Copy)]
283 Covariant, // T<A> <: T<B> iff A <: B -- e.g., function return type
284 Invariant, // T<A> <: T<B> iff B == A -- e.g., type of mutable cell
285 Contravariant, // T<A> <: T<B> iff B <: A -- e.g., function param type
286 Bivariant, // T<A> <: T<B> -- e.g., unused type parameter
289 #[derive(Clone, Debug)]
290 pub enum AutoAdjustment<'tcx> {
291 AdjustReifyFnPointer(ast::DefId), // go from a fn-item type to a fn-pointer type
292 AdjustDerefRef(AutoDerefRef<'tcx>)
295 #[derive(Clone, PartialEq, Debug)]
296 pub enum UnsizeKind<'tcx> {
297 // [T, ..n] -> [T], the uint field is n.
299 // An unsize coercion applied to the tail field of a struct.
300 // The uint is the index of the type parameter which is unsized.
301 UnsizeStruct(Box<UnsizeKind<'tcx>>, uint),
302 UnsizeVtable(TyTrait<'tcx>, /* the self type of the trait */ Ty<'tcx>)
305 #[derive(Clone, Debug)]
306 pub struct AutoDerefRef<'tcx> {
307 pub autoderefs: uint,
308 pub autoref: Option<AutoRef<'tcx>>
311 #[derive(Clone, PartialEq, Debug)]
312 pub enum AutoRef<'tcx> {
313 /// Convert from T to &T
314 /// The third field allows us to wrap other AutoRef adjustments.
315 AutoPtr(Region, ast::Mutability, Option<Box<AutoRef<'tcx>>>),
317 /// Convert [T, ..n] to [T] (or similar, depending on the kind)
318 AutoUnsize(UnsizeKind<'tcx>),
320 /// Convert Box<[T, ..n]> to Box<[T]> or something similar in a Box.
321 /// With DST and Box a library type, this should be replaced by UnsizeStruct.
322 AutoUnsizeUniq(UnsizeKind<'tcx>),
324 /// Convert from T to *T
325 /// Value to thin pointer
326 /// The second field allows us to wrap other AutoRef adjustments.
327 AutoUnsafe(ast::Mutability, Option<Box<AutoRef<'tcx>>>),
330 // Ugly little helper function. The first bool in the returned tuple is true if
331 // there is an 'unsize to trait object' adjustment at the bottom of the
332 // adjustment. If that is surrounded by an AutoPtr, then we also return the
333 // region of the AutoPtr (in the third argument). The second bool is true if the
334 // adjustment is unique.
335 fn autoref_object_region(autoref: &AutoRef) -> (bool, bool, Option<Region>) {
336 fn unsize_kind_is_object(k: &UnsizeKind) -> bool {
338 &UnsizeVtable(..) => true,
339 &UnsizeStruct(box ref k, _) => unsize_kind_is_object(k),
345 &AutoUnsize(ref k) => (unsize_kind_is_object(k), false, None),
346 &AutoUnsizeUniq(ref k) => (unsize_kind_is_object(k), true, None),
347 &AutoPtr(adj_r, _, Some(box ref autoref)) => {
348 let (b, u, r) = autoref_object_region(autoref);
349 if r.is_some() || u {
355 &AutoUnsafe(_, Some(box ref autoref)) => autoref_object_region(autoref),
356 _ => (false, false, None)
360 // If the adjustment introduces a borrowed reference to a trait object, then
361 // returns the region of the borrowed reference.
362 pub fn adjusted_object_region(adj: &AutoAdjustment) -> Option<Region> {
364 &AdjustDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
365 let (b, _, r) = autoref_object_region(autoref);
376 // Returns true if there is a trait cast at the bottom of the adjustment.
377 pub fn adjust_is_object(adj: &AutoAdjustment) -> bool {
379 &AdjustDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
380 let (b, _, _) = autoref_object_region(autoref);
387 // If possible, returns the type expected from the given adjustment. This is not
388 // possible if the adjustment depends on the type of the adjusted expression.
389 pub fn type_of_adjust<'tcx>(cx: &ctxt<'tcx>, adj: &AutoAdjustment<'tcx>) -> Option<Ty<'tcx>> {
390 fn type_of_autoref<'tcx>(cx: &ctxt<'tcx>, autoref: &AutoRef<'tcx>) -> Option<Ty<'tcx>> {
392 &AutoUnsize(ref k) => match k {
393 &UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
394 Some(mk_trait(cx, principal.clone(), bounds.clone()))
398 &AutoUnsizeUniq(ref k) => match k {
399 &UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
400 Some(mk_uniq(cx, mk_trait(cx, principal.clone(), bounds.clone())))
404 &AutoPtr(r, m, Some(box ref autoref)) => {
405 match type_of_autoref(cx, autoref) {
406 Some(ty) => Some(mk_rptr(cx, cx.mk_region(r), mt {mutbl: m, ty: ty})),
410 &AutoUnsafe(m, Some(box ref autoref)) => {
411 match type_of_autoref(cx, autoref) {
412 Some(ty) => Some(mk_ptr(cx, mt {mutbl: m, ty: ty})),
421 &AdjustDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
422 type_of_autoref(cx, autoref)
428 #[derive(Clone, Copy, RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Debug)]
429 pub struct param_index {
430 pub space: subst::ParamSpace,
434 #[derive(Clone, Debug)]
435 pub enum MethodOrigin<'tcx> {
436 // fully statically resolved method
437 MethodStatic(ast::DefId),
439 // fully statically resolved closure invocation
440 MethodStaticClosure(ast::DefId),
442 // method invoked on a type parameter with a bounded trait
443 MethodTypeParam(MethodParam<'tcx>),
445 // method invoked on a trait instance
446 MethodTraitObject(MethodObject<'tcx>),
450 // details for a method invoked with a receiver whose type is a type parameter
451 // with a bounded trait.
452 #[derive(Clone, Debug)]
453 pub struct MethodParam<'tcx> {
454 // the precise trait reference that occurs as a bound -- this may
455 // be a supertrait of what the user actually typed. Note that it
456 // never contains bound regions; those regions should have been
457 // instantiated with fresh variables at this point.
458 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
460 // index of uint in the list of trait items. Note that this is NOT
461 // the index into the vtable, because the list of trait items
462 // includes associated types.
463 pub method_num: uint,
465 /// The impl for the trait from which the method comes. This
466 /// should only be used for certain linting/heuristic purposes
467 /// since there is no guarantee that this is Some in every
468 /// situation that it could/should be.
469 pub impl_def_id: Option<ast::DefId>,
472 // details for a method invoked with a receiver whose type is an object
473 #[derive(Clone, Debug)]
474 pub struct MethodObject<'tcx> {
475 // the (super)trait containing the method to be invoked
476 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
478 // the actual base trait id of the object
479 pub object_trait_id: ast::DefId,
481 // index of the method to be invoked amongst the trait's items
482 pub method_num: uint,
484 // index into the actual runtime vtable.
485 // the vtable is formed by concatenating together the method lists of
486 // the base object trait and all supertraits; this is the index into
488 pub vtable_index: uint,
492 pub struct MethodCallee<'tcx> {
493 pub origin: MethodOrigin<'tcx>,
495 pub substs: subst::Substs<'tcx>
498 /// With method calls, we store some extra information in
499 /// side tables (i.e method_map). We use
500 /// MethodCall as a key to index into these tables instead of
501 /// just directly using the expression's NodeId. The reason
502 /// for this being that we may apply adjustments (coercions)
503 /// with the resulting expression also needing to use the
504 /// side tables. The problem with this is that we don't
505 /// assign a separate NodeId to this new expression
506 /// and so it would clash with the base expression if both
507 /// needed to add to the side tables. Thus to disambiguate
508 /// we also keep track of whether there's an adjustment in
510 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
511 pub struct MethodCall {
512 pub expr_id: ast::NodeId,
513 pub adjustment: ExprAdjustment
516 #[derive(Clone, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable, Copy)]
517 pub enum ExprAdjustment {
524 pub fn expr(id: ast::NodeId) -> MethodCall {
527 adjustment: NoAdjustment
531 pub fn autoobject(id: ast::NodeId) -> MethodCall {
534 adjustment: AutoObject
538 pub fn autoderef(expr_id: ast::NodeId, autoderef: uint) -> MethodCall {
541 adjustment: AutoDeref(1 + autoderef)
546 // maps from an expression id that corresponds to a method call to the details
547 // of the method to be invoked
548 pub type MethodMap<'tcx> = RefCell<FnvHashMap<MethodCall, MethodCallee<'tcx>>>;
550 pub type vtable_param_res<'tcx> = Vec<vtable_origin<'tcx>>;
552 // Resolutions for bounds of all parameters, left to right, for a given path.
553 pub type vtable_res<'tcx> = VecPerParamSpace<vtable_param_res<'tcx>>;
556 pub enum vtable_origin<'tcx> {
558 Statically known vtable. def_id gives the impl item
559 from whence comes the vtable, and tys are the type substs.
560 vtable_res is the vtable itself.
562 vtable_static(ast::DefId, subst::Substs<'tcx>, vtable_res<'tcx>),
565 Dynamic vtable, comes from a parameter that has a bound on it:
566 fn foo<T:quux,baz,bar>(a: T) -- a's vtable would have a
569 The first argument is the param index (identifying T in the example),
570 and the second is the bound number (identifying baz)
572 vtable_param(param_index, uint),
575 Vtable automatically generated for a closure. The def ID is the
576 ID of the closure expression.
578 vtable_closure(ast::DefId),
581 Asked to determine the vtable for ty_err. This is the value used
582 for the vtables of `Self` in a virtual call like `foo.bar()`
583 where `foo` is of object type. The same value is also used when
590 // For every explicit cast into an object type, maps from the cast
591 // expr to the associated trait ref.
592 pub type ObjectCastMap<'tcx> = RefCell<NodeMap<ty::PolyTraitRef<'tcx>>>;
594 /// A restriction that certain types must be the same size. The use of
595 /// `transmute` gives rise to these restrictions. These generally
596 /// cannot be checked until trans; therefore, each call to `transmute`
597 /// will push one or more such restriction into the
598 /// `transmute_restrictions` vector during `intrinsicck`. They are
599 /// then checked during `trans` by the fn `check_intrinsics`.
601 pub struct TransmuteRestriction<'tcx> {
602 /// The span whence the restriction comes.
605 /// The type being transmuted from.
606 pub original_from: Ty<'tcx>,
608 /// The type being transmuted to.
609 pub original_to: Ty<'tcx>,
611 /// The type being transmuted from, with all type parameters
612 /// substituted for an arbitrary representative. Not to be shown
614 pub substituted_from: Ty<'tcx>,
616 /// The type being transmuted to, with all type parameters
617 /// substituted for an arbitrary representative. Not to be shown
619 pub substituted_to: Ty<'tcx>,
621 /// NodeId of the transmute intrinsic.
626 pub struct CtxtArenas<'tcx> {
627 type_: TypedArena<TyS<'tcx>>,
628 substs: TypedArena<Substs<'tcx>>,
629 bare_fn: TypedArena<BareFnTy<'tcx>>,
630 region: TypedArena<Region>,
633 impl<'tcx> CtxtArenas<'tcx> {
634 pub fn new() -> CtxtArenas<'tcx> {
636 type_: TypedArena::new(),
637 substs: TypedArena::new(),
638 bare_fn: TypedArena::new(),
639 region: TypedArena::new(),
644 pub struct CommonTypes<'tcx> {
662 /// The data structure to keep track of all the information that typechecker
663 /// generates so that so that it can be reused and doesn't have to be redone
665 pub struct ctxt<'tcx> {
666 /// The arenas that types etc are allocated from.
667 arenas: &'tcx CtxtArenas<'tcx>,
669 /// Specifically use a speedy hash algorithm for this hash map, it's used
671 // FIXME(eddyb) use a FnvHashSet<InternedTy<'tcx>> when equivalent keys can
672 // queried from a HashSet.
673 interner: RefCell<FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>>,
675 // FIXME as above, use a hashset if equivalent elements can be queried.
676 substs_interner: RefCell<FnvHashMap<&'tcx Substs<'tcx>, &'tcx Substs<'tcx>>>,
677 bare_fn_interner: RefCell<FnvHashMap<&'tcx BareFnTy<'tcx>, &'tcx BareFnTy<'tcx>>>,
678 region_interner: RefCell<FnvHashMap<&'tcx Region, &'tcx Region>>,
680 /// Common types, pre-interned for your convenience.
681 pub types: CommonTypes<'tcx>,
686 pub named_region_map: resolve_lifetime::NamedRegionMap,
688 pub region_maps: middle::region::RegionMaps,
690 /// Stores the types for various nodes in the AST. Note that this table
691 /// is not guaranteed to be populated until after typeck. See
692 /// typeck::check::fn_ctxt for details.
693 pub node_types: RefCell<NodeMap<Ty<'tcx>>>,
695 /// Stores the type parameters which were substituted to obtain the type
696 /// of this node. This only applies to nodes that refer to entities
697 /// parameterized by type parameters, such as generic fns, types, or
699 pub item_substs: RefCell<NodeMap<ItemSubsts<'tcx>>>,
701 /// Maps from a trait item to the trait item "descriptor"
702 pub impl_or_trait_items: RefCell<DefIdMap<ImplOrTraitItem<'tcx>>>,
704 /// Maps from a trait def-id to a list of the def-ids of its trait items
705 pub trait_item_def_ids: RefCell<DefIdMap<Rc<Vec<ImplOrTraitItemId>>>>,
707 /// A cache for the trait_items() routine
708 pub trait_items_cache: RefCell<DefIdMap<Rc<Vec<ImplOrTraitItem<'tcx>>>>>,
710 pub impl_trait_cache: RefCell<DefIdMap<Option<Rc<ty::TraitRef<'tcx>>>>>,
712 pub trait_refs: RefCell<NodeMap<Rc<TraitRef<'tcx>>>>,
713 pub trait_defs: RefCell<DefIdMap<Rc<TraitDef<'tcx>>>>,
715 /// Maps from the def-id of an item (trait/struct/enum/fn) to its
716 /// associated predicates.
717 pub predicates: RefCell<DefIdMap<GenericPredicates<'tcx>>>,
719 /// Maps from node-id of a trait object cast (like `foo as
720 /// Box<Trait>`) to the trait reference.
721 pub object_cast_map: ObjectCastMap<'tcx>,
723 pub map: ast_map::Map<'tcx>,
724 pub intrinsic_defs: RefCell<DefIdMap<Ty<'tcx>>>,
725 pub freevars: RefCell<FreevarMap>,
726 pub tcache: RefCell<DefIdMap<TypeScheme<'tcx>>>,
727 pub rcache: RefCell<FnvHashMap<creader_cache_key, Ty<'tcx>>>,
728 pub short_names_cache: RefCell<FnvHashMap<Ty<'tcx>, String>>,
729 pub tc_cache: RefCell<FnvHashMap<Ty<'tcx>, TypeContents>>,
730 pub ast_ty_to_ty_cache: RefCell<NodeMap<ast_ty_to_ty_cache_entry<'tcx>>>,
731 pub enum_var_cache: RefCell<DefIdMap<Rc<Vec<Rc<VariantInfo<'tcx>>>>>>,
732 pub ty_param_defs: RefCell<NodeMap<TypeParameterDef<'tcx>>>,
733 pub adjustments: RefCell<NodeMap<AutoAdjustment<'tcx>>>,
734 pub normalized_cache: RefCell<FnvHashMap<Ty<'tcx>, Ty<'tcx>>>,
735 pub lang_items: middle::lang_items::LanguageItems,
736 /// A mapping of fake provided method def_ids to the default implementation
737 pub provided_method_sources: RefCell<DefIdMap<ast::DefId>>,
738 pub struct_fields: RefCell<DefIdMap<Rc<Vec<field_ty>>>>,
740 /// Maps from def-id of a type or region parameter to its
741 /// (inferred) variance.
742 pub item_variance_map: RefCell<DefIdMap<Rc<ItemVariances>>>,
744 /// True if the variance has been computed yet; false otherwise.
745 pub variance_computed: Cell<bool>,
747 /// A mapping from the def ID of an enum or struct type to the def ID
748 /// of the method that implements its destructor. If the type is not
749 /// present in this map, it does not have a destructor. This map is
750 /// populated during the coherence phase of typechecking.
751 pub destructor_for_type: RefCell<DefIdMap<ast::DefId>>,
753 /// A method will be in this list if and only if it is a destructor.
754 pub destructors: RefCell<DefIdSet>,
756 /// Maps a trait onto a list of impls of that trait.
757 pub trait_impls: RefCell<DefIdMap<Rc<RefCell<Vec<ast::DefId>>>>>,
759 /// Maps a DefId of a type to a list of its inherent impls.
760 /// Contains implementations of methods that are inherent to a type.
761 /// Methods in these implementations don't need to be exported.
762 pub inherent_impls: RefCell<DefIdMap<Rc<Vec<ast::DefId>>>>,
764 /// Maps a DefId of an impl to a list of its items.
765 /// Note that this contains all of the impls that we know about,
766 /// including ones in other crates. It's not clear that this is the best
768 pub impl_items: RefCell<DefIdMap<Vec<ImplOrTraitItemId>>>,
770 /// Set of used unsafe nodes (functions or blocks). Unsafe nodes not
771 /// present in this set can be warned about.
772 pub used_unsafe: RefCell<NodeSet>,
774 /// Set of nodes which mark locals as mutable which end up getting used at
775 /// some point. Local variable definitions not in this set can be warned
777 pub used_mut_nodes: RefCell<NodeSet>,
779 /// The set of external nominal types whose implementations have been read.
780 /// This is used for lazy resolution of methods.
781 pub populated_external_types: RefCell<DefIdSet>,
783 /// The set of external traits whose implementations have been read. This
784 /// is used for lazy resolution of traits.
785 pub populated_external_traits: RefCell<DefIdSet>,
788 pub upvar_capture_map: RefCell<UpvarCaptureMap>,
790 /// These two caches are used by const_eval when decoding external statics
791 /// and variants that are found.
792 pub extern_const_statics: RefCell<DefIdMap<ast::NodeId>>,
793 pub extern_const_variants: RefCell<DefIdMap<ast::NodeId>>,
795 pub method_map: MethodMap<'tcx>,
797 pub dependency_formats: RefCell<dependency_format::Dependencies>,
799 /// Records the type of each closure. The def ID is the ID of the
800 /// expression defining the closure.
801 pub closure_kinds: RefCell<DefIdMap<ClosureKind>>,
803 /// Records the type of each closure. The def ID is the ID of the
804 /// expression defining the closure.
805 pub closure_tys: RefCell<DefIdMap<ClosureTy<'tcx>>>,
807 pub node_lint_levels: RefCell<FnvHashMap<(ast::NodeId, lint::LintId),
810 /// The types that must be asserted to be the same size for `transmute`
811 /// to be valid. We gather up these restrictions in the intrinsicck pass
812 /// and check them in trans.
813 pub transmute_restrictions: RefCell<Vec<TransmuteRestriction<'tcx>>>,
815 /// Maps any item's def-id to its stability index.
816 pub stability: RefCell<stability::Index>,
818 /// Maps def IDs to true if and only if they're associated types.
819 pub associated_types: RefCell<DefIdMap<bool>>,
821 /// Caches the results of trait selection. This cache is used
822 /// for things that do not have to do with the parameters in scope.
823 pub selection_cache: traits::SelectionCache<'tcx>,
825 /// Caches the representation hints for struct definitions.
826 pub repr_hint_cache: RefCell<DefIdMap<Rc<Vec<attr::ReprAttr>>>>,
828 /// Caches whether types are known to impl Copy. Note that type
829 /// parameters are never placed into this cache, because their
830 /// results are dependent on the parameter environment.
831 pub type_impls_copy_cache: RefCell<HashMap<Ty<'tcx>,bool>>,
833 /// Caches whether types are known to impl Sized. Note that type
834 /// parameters are never placed into this cache, because their
835 /// results are dependent on the parameter environment.
836 pub type_impls_sized_cache: RefCell<HashMap<Ty<'tcx>,bool>>,
838 /// Caches whether traits are object safe
839 pub object_safety_cache: RefCell<DefIdMap<bool>>,
841 /// Maps Expr NodeId's to their constant qualification.
842 pub const_qualif_map: RefCell<NodeMap<check_const::ConstQualif>>,
845 // Flags that we track on types. These flags are propagated upwards
846 // through the type during type construction, so that we can quickly
847 // check whether the type has various kinds of types in it without
848 // recursing over the type itself.
850 flags TypeFlags: u32 {
851 const NO_TYPE_FLAGS = 0b0,
852 const HAS_PARAMS = 0b1,
853 const HAS_SELF = 0b10,
854 const HAS_TY_INFER = 0b100,
855 const HAS_RE_INFER = 0b1000,
856 const HAS_RE_LATE_BOUND = 0b10000,
857 const HAS_REGIONS = 0b100000,
858 const HAS_TY_ERR = 0b1000000,
859 const HAS_PROJECTION = 0b10000000,
860 const NEEDS_SUBST = HAS_PARAMS.bits | HAS_SELF.bits | HAS_REGIONS.bits,
864 macro_rules! sty_debug_print {
865 ($ctxt: expr, $($variant: ident),*) => {{
866 // curious inner module to allow variant names to be used as
878 pub fn go(tcx: &ty::ctxt) {
879 let mut total = DebugStat {
881 region_infer: 0, ty_infer: 0, both_infer: 0,
883 $(let mut $variant = total;)*
886 for (_, t) in &*tcx.interner.borrow() {
887 let variant = match t.sty {
888 ty::ty_bool | ty::ty_char | ty::ty_int(..) | ty::ty_uint(..) |
889 ty::ty_float(..) | ty::ty_str => continue,
890 ty::ty_err => /* unimportant */ continue,
891 $(ty::$variant(..) => &mut $variant,)*
893 let region = t.flags.intersects(ty::HAS_RE_INFER);
894 let ty = t.flags.intersects(ty::HAS_TY_INFER);
898 if region { total.region_infer += 1; variant.region_infer += 1 }
899 if ty { total.ty_infer += 1; variant.ty_infer += 1 }
900 if region && ty { total.both_infer += 1; variant.both_infer += 1 }
902 println!("Ty interner total ty region both");
903 $(println!(" {:18}: {uses:6} {usespc:4.1}%, \
904 {ty:4.1}% {region:5.1}% {both:4.1}%",
905 stringify!($variant),
906 uses = $variant.total,
907 usespc = $variant.total as f64 * 100.0 / total.total as f64,
908 ty = $variant.ty_infer as f64 * 100.0 / total.total as f64,
909 region = $variant.region_infer as f64 * 100.0 / total.total as f64,
910 both = $variant.both_infer as f64 * 100.0 / total.total as f64);
912 println!(" total {uses:6} \
913 {ty:4.1}% {region:5.1}% {both:4.1}%",
915 ty = total.ty_infer as f64 * 100.0 / total.total as f64,
916 region = total.region_infer as f64 * 100.0 / total.total as f64,
917 both = total.both_infer as f64 * 100.0 / total.total as f64)
925 impl<'tcx> ctxt<'tcx> {
926 pub fn print_debug_stats(&self) {
929 ty_enum, ty_uniq, ty_vec, ty_ptr, ty_rptr, ty_bare_fn, ty_trait,
930 ty_struct, ty_closure, ty_tup, ty_param, ty_open, ty_infer, ty_projection);
932 println!("Substs interner: #{}", self.substs_interner.borrow().len());
933 println!("BareFnTy interner: #{}", self.bare_fn_interner.borrow().len());
934 println!("Region interner: #{}", self.region_interner.borrow().len());
939 pub struct TyS<'tcx> {
941 pub flags: TypeFlags,
943 // the maximal depth of any bound regions appearing in this type.
947 impl fmt::Debug for TypeFlags {
948 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
949 write!(f, "{}", self.bits)
953 impl<'tcx> PartialEq for TyS<'tcx> {
954 fn eq(&self, other: &TyS<'tcx>) -> bool {
955 // (self as *const _) == (other as *const _)
956 (self as *const TyS<'tcx>) == (other as *const TyS<'tcx>)
959 impl<'tcx> Eq for TyS<'tcx> {}
961 impl<'tcx, S: Writer + Hasher> Hash<S> for TyS<'tcx> {
962 fn hash(&self, s: &mut S) {
963 (self as *const _).hash(s)
967 pub type Ty<'tcx> = &'tcx TyS<'tcx>;
969 /// An entry in the type interner.
970 pub struct InternedTy<'tcx> {
974 // NB: An InternedTy compares and hashes as a sty.
975 impl<'tcx> PartialEq for InternedTy<'tcx> {
976 fn eq(&self, other: &InternedTy<'tcx>) -> bool {
977 self.ty.sty == other.ty.sty
981 impl<'tcx> Eq for InternedTy<'tcx> {}
983 impl<'tcx, S: Writer + Hasher> Hash<S> for InternedTy<'tcx> {
984 fn hash(&self, s: &mut S) {
989 impl<'tcx> BorrowFrom<InternedTy<'tcx>> for sty<'tcx> {
990 fn borrow_from<'a>(ty: &'a InternedTy<'tcx>) -> &'a sty<'tcx> {
995 pub fn type_has_params(ty: Ty) -> bool {
996 ty.flags.intersects(HAS_PARAMS)
998 pub fn type_has_self(ty: Ty) -> bool {
999 ty.flags.intersects(HAS_SELF)
1001 pub fn type_has_ty_infer(ty: Ty) -> bool {
1002 ty.flags.intersects(HAS_TY_INFER)
1004 pub fn type_needs_infer(ty: Ty) -> bool {
1005 ty.flags.intersects(HAS_TY_INFER | HAS_RE_INFER)
1007 pub fn type_has_projection(ty: Ty) -> bool {
1008 ty.flags.intersects(HAS_PROJECTION)
1011 pub fn type_has_late_bound_regions(ty: Ty) -> bool {
1012 ty.flags.intersects(HAS_RE_LATE_BOUND)
1015 /// An "escaping region" is a bound region whose binder is not part of `t`.
1017 /// So, for example, consider a type like the following, which has two binders:
1019 /// for<'a> fn(x: for<'b> fn(&'a int, &'b int))
1020 /// ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ outer scope
1021 /// ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ inner scope
1023 /// This type has *bound regions* (`'a`, `'b`), but it does not have escaping regions, because the
1024 /// binders of both `'a` and `'b` are part of the type itself. However, if we consider the *inner
1025 /// fn type*, that type has an escaping region: `'a`.
1027 /// Note that what I'm calling an "escaping region" is often just called a "free region". However,
1028 /// we already use the term "free region". It refers to the regions that we use to represent bound
1029 /// regions on a fn definition while we are typechecking its body.
1031 /// To clarify, conceptually there is no particular difference between an "escaping" region and a
1032 /// "free" region. However, there is a big difference in practice. Basically, when "entering" a
1033 /// binding level, one is generally required to do some sort of processing to a bound region, such
1034 /// as replacing it with a fresh/skolemized region, or making an entry in the environment to
1035 /// represent the scope to which it is attached, etc. An escaping region represents a bound region
1036 /// for which this processing has not yet been done.
1037 pub fn type_has_escaping_regions(ty: Ty) -> bool {
1038 type_escapes_depth(ty, 0)
1041 pub fn type_escapes_depth(ty: Ty, depth: u32) -> bool {
1042 ty.region_depth > depth
1045 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
1046 pub struct BareFnTy<'tcx> {
1047 pub unsafety: ast::Unsafety,
1049 pub sig: PolyFnSig<'tcx>,
1052 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
1053 pub struct ClosureTy<'tcx> {
1054 pub unsafety: ast::Unsafety,
1056 pub sig: PolyFnSig<'tcx>,
1059 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
1060 pub enum FnOutput<'tcx> {
1061 FnConverging(Ty<'tcx>),
1065 impl<'tcx> FnOutput<'tcx> {
1066 pub fn diverges(&self) -> bool {
1067 *self == FnDiverging
1070 pub fn unwrap(self) -> Ty<'tcx> {
1072 ty::FnConverging(t) => t,
1073 ty::FnDiverging => unreachable!()
1078 pub type PolyFnOutput<'tcx> = Binder<FnOutput<'tcx>>;
1080 impl<'tcx> PolyFnOutput<'tcx> {
1081 pub fn diverges(&self) -> bool {
1086 /// Signature of a function type, which I have arbitrarily
1087 /// decided to use to refer to the input/output types.
1089 /// - `inputs` is the list of arguments and their modes.
1090 /// - `output` is the return type.
1091 /// - `variadic` indicates whether this is a variadic function. (only true for foreign fns)
1092 #[derive(Clone, PartialEq, Eq, Hash)]
1093 pub struct FnSig<'tcx> {
1094 pub inputs: Vec<Ty<'tcx>>,
1095 pub output: FnOutput<'tcx>,
1099 pub type PolyFnSig<'tcx> = Binder<FnSig<'tcx>>;
1101 impl<'tcx> PolyFnSig<'tcx> {
1102 pub fn inputs(&self) -> ty::Binder<Vec<Ty<'tcx>>> {
1103 ty::Binder(self.0.inputs.clone())
1105 pub fn input(&self, index: uint) -> ty::Binder<Ty<'tcx>> {
1106 ty::Binder(self.0.inputs[index])
1108 pub fn output(&self) -> ty::Binder<FnOutput<'tcx>> {
1109 ty::Binder(self.0.output.clone())
1111 pub fn variadic(&self) -> bool {
1116 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
1117 pub struct ParamTy {
1118 pub space: subst::ParamSpace,
1120 pub name: ast::Name,
1123 /// A [De Bruijn index][dbi] is a standard means of representing
1124 /// regions (and perhaps later types) in a higher-ranked setting. In
1125 /// particular, imagine a type like this:
1127 /// for<'a> fn(for<'b> fn(&'b int, &'a int), &'a char)
1130 /// | +------------+ 1 | |
1132 /// +--------------------------------+ 2 |
1134 /// +------------------------------------------+ 1
1136 /// In this type, there are two binders (the outer fn and the inner
1137 /// fn). We need to be able to determine, for any given region, which
1138 /// fn type it is bound by, the inner or the outer one. There are
1139 /// various ways you can do this, but a De Bruijn index is one of the
1140 /// more convenient and has some nice properties. The basic idea is to
1141 /// count the number of binders, inside out. Some examples should help
1142 /// clarify what I mean.
1144 /// Let's start with the reference type `&'b int` that is the first
1145 /// argument to the inner function. This region `'b` is assigned a De
1146 /// Bruijn index of 1, meaning "the innermost binder" (in this case, a
1147 /// fn). The region `'a` that appears in the second argument type (`&'a
1148 /// int`) would then be assigned a De Bruijn index of 2, meaning "the
1149 /// second-innermost binder". (These indices are written on the arrays
1150 /// in the diagram).
1152 /// What is interesting is that De Bruijn index attached to a particular
1153 /// variable will vary depending on where it appears. For example,
1154 /// the final type `&'a char` also refers to the region `'a` declared on
1155 /// the outermost fn. But this time, this reference is not nested within
1156 /// any other binders (i.e., it is not an argument to the inner fn, but
1157 /// rather the outer one). Therefore, in this case, it is assigned a
1158 /// De Bruijn index of 1, because the innermost binder in that location
1159 /// is the outer fn.
1161 /// [dbi]: http://en.wikipedia.org/wiki/De_Bruijn_index
1162 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Debug, Copy)]
1163 pub struct DebruijnIndex {
1164 // We maintain the invariant that this is never 0. So 1 indicates
1165 // the innermost binder. To ensure this, create with `DebruijnIndex::new`.
1169 /// Representation of regions:
1170 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Debug, Copy)]
1172 // Region bound in a type or fn declaration which will be
1173 // substituted 'early' -- that is, at the same time when type
1174 // parameters are substituted.
1175 ReEarlyBound(/* param id */ ast::NodeId,
1180 // Region bound in a function scope, which will be substituted when the
1181 // function is called.
1182 ReLateBound(DebruijnIndex, BoundRegion),
1184 /// When checking a function body, the types of all arguments and so forth
1185 /// that refer to bound region parameters are modified to refer to free
1186 /// region parameters.
1189 /// A concrete region naming some statically determined extent
1190 /// (e.g. an expression or sequence of statements) within the
1191 /// current function.
1192 ReScope(region::CodeExtent),
1194 /// Static data that has an "infinite" lifetime. Top in the region lattice.
1197 /// A region variable. Should not exist after typeck.
1198 ReInfer(InferRegion),
1200 /// Empty lifetime is for data that is never accessed.
1201 /// Bottom in the region lattice. We treat ReEmpty somewhat
1202 /// specially; at least right now, we do not generate instances of
1203 /// it during the GLB computations, but rather
1204 /// generate an error instead. This is to improve error messages.
1205 /// The only way to get an instance of ReEmpty is to have a region
1206 /// variable with no constraints.
1210 /// Upvars do not get their own node-id. Instead, we use the pair of
1211 /// the original var id (that is, the root variable that is referenced
1212 /// by the upvar) and the id of the closure expression.
1213 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
1214 pub struct UpvarId {
1215 pub var_id: ast::NodeId,
1216 pub closure_expr_id: ast::NodeId,
1219 #[derive(Clone, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable, Copy)]
1220 pub enum BorrowKind {
1221 /// Data must be immutable and is aliasable.
1224 /// Data must be immutable but not aliasable. This kind of borrow
1225 /// cannot currently be expressed by the user and is used only in
1226 /// implicit closure bindings. It is needed when you the closure
1227 /// is borrowing or mutating a mutable referent, e.g.:
1229 /// let x: &mut int = ...;
1230 /// let y = || *x += 5;
1232 /// If we were to try to translate this closure into a more explicit
1233 /// form, we'd encounter an error with the code as written:
1235 /// struct Env { x: & &mut int }
1236 /// let x: &mut int = ...;
1237 /// let y = (&mut Env { &x }, fn_ptr); // Closure is pair of env and fn
1238 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
1240 /// This is then illegal because you cannot mutate a `&mut` found
1241 /// in an aliasable location. To solve, you'd have to translate with
1242 /// an `&mut` borrow:
1244 /// struct Env { x: & &mut int }
1245 /// let x: &mut int = ...;
1246 /// let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x
1247 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
1249 /// Now the assignment to `**env.x` is legal, but creating a
1250 /// mutable pointer to `x` is not because `x` is not mutable. We
1251 /// could fix this by declaring `x` as `let mut x`. This is ok in
1252 /// user code, if awkward, but extra weird for closures, since the
1253 /// borrow is hidden.
1255 /// So we introduce a "unique imm" borrow -- the referent is
1256 /// immutable, but not aliasable. This solves the problem. For
1257 /// simplicity, we don't give users the way to express this
1258 /// borrow, it's just used when translating closures.
1261 /// Data is mutable and not aliasable.
1265 /// Information describing the capture of an upvar. This is computed
1266 /// during `typeck`, specifically by `regionck`.
1267 #[derive(PartialEq, Clone, RustcEncodable, RustcDecodable, Debug, Copy)]
1268 pub enum UpvarCapture {
1269 /// Upvar is captured by value. This is always true when the
1270 /// closure is labeled `move`, but can also be true in other cases
1271 /// depending on inference.
1274 /// Upvar is captured by reference.
1278 #[derive(PartialEq, Clone, RustcEncodable, RustcDecodable, Debug, Copy)]
1279 pub struct UpvarBorrow {
1280 /// The kind of borrow: by-ref upvars have access to shared
1281 /// immutable borrows, which are not part of the normal language
1283 pub kind: BorrowKind,
1285 /// Region of the resulting reference.
1286 pub region: ty::Region,
1289 pub type UpvarCaptureMap = FnvHashMap<UpvarId, UpvarCapture>;
1292 pub fn is_bound(&self) -> bool {
1294 ty::ReEarlyBound(..) => true,
1295 ty::ReLateBound(..) => true,
1300 pub fn escapes_depth(&self, depth: u32) -> bool {
1302 ty::ReLateBound(debruijn, _) => debruijn.depth > depth,
1308 #[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
1309 RustcEncodable, RustcDecodable, Debug, Copy)]
1310 /// A "free" region `fr` can be interpreted as "some region
1311 /// at least as big as the scope `fr.scope`".
1312 pub struct FreeRegion {
1313 pub scope: region::DestructionScopeData,
1314 pub bound_region: BoundRegion
1317 #[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
1318 RustcEncodable, RustcDecodable, Debug, Copy)]
1319 pub enum BoundRegion {
1320 /// An anonymous region parameter for a given fn (&T)
1323 /// Named region parameters for functions (a in &'a T)
1325 /// The def-id is needed to distinguish free regions in
1326 /// the event of shadowing.
1327 BrNamed(ast::DefId, ast::Name),
1329 /// Fresh bound identifiers created during GLB computations.
1332 // Anonymous region for the implicit env pointer parameter
1337 // NB: If you change this, you'll probably want to change the corresponding
1338 // AST structure in libsyntax/ast.rs as well.
1339 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
1340 pub enum sty<'tcx> {
1344 ty_uint(ast::UintTy),
1345 ty_float(ast::FloatTy),
1346 /// Substs here, possibly against intuition, *may* contain `ty_param`s.
1347 /// That is, even after substitution it is possible that there are type
1348 /// variables. This happens when the `ty_enum` corresponds to an enum
1349 /// definition and not a concrete use of it. To get the correct `ty_enum`
1350 /// from the tcx, use the `NodeId` from the `ast::Ty` and look it up in
1351 /// the `ast_ty_to_ty_cache`. This is probably true for `ty_struct` as
1353 ty_enum(DefId, &'tcx Substs<'tcx>),
1356 ty_vec(Ty<'tcx>, Option<uint>), // Second field is length.
1358 ty_rptr(&'tcx Region, mt<'tcx>),
1360 // If the def-id is Some(_), then this is the type of a specific
1361 // fn item. Otherwise, if None(_), it a fn pointer type.
1362 ty_bare_fn(Option<DefId>, &'tcx BareFnTy<'tcx>),
1364 ty_trait(Box<TyTrait<'tcx>>),
1365 ty_struct(DefId, &'tcx Substs<'tcx>),
1367 ty_closure(DefId, &'tcx Region, &'tcx Substs<'tcx>),
1369 ty_tup(Vec<Ty<'tcx>>),
1371 ty_projection(ProjectionTy<'tcx>),
1372 ty_param(ParamTy), // type parameter
1374 ty_open(Ty<'tcx>), // A deref'ed fat pointer, i.e., a dynamically sized value
1375 // and its size. Only ever used in trans. It is not necessary
1376 // earlier since we don't need to distinguish a DST with its
1377 // size (e.g., in a deref) vs a DST with the size elsewhere (
1378 // e.g., in a field).
1380 ty_infer(InferTy), // something used only during inference/typeck
1381 ty_err, // Also only used during inference/typeck, to represent
1382 // the type of an erroneous expression (helps cut down
1383 // on non-useful type error messages)
1386 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
1387 pub struct TyTrait<'tcx> {
1388 pub principal: ty::PolyTraitRef<'tcx>,
1389 pub bounds: ExistentialBounds<'tcx>,
1392 impl<'tcx> TyTrait<'tcx> {
1393 pub fn principal_def_id(&self) -> ast::DefId {
1394 self.principal.0.def_id
1397 /// Object types don't have a self-type specified. Therefore, when
1398 /// we convert the principal trait-ref into a normal trait-ref,
1399 /// you must give *some* self-type. A common choice is `mk_err()`
1400 /// or some skolemized type.
1401 pub fn principal_trait_ref_with_self_ty(&self,
1404 -> ty::PolyTraitRef<'tcx>
1406 // otherwise the escaping regions would be captured by the binder
1407 assert!(!self_ty.has_escaping_regions());
1409 ty::Binder(Rc::new(ty::TraitRef {
1410 def_id: self.principal.0.def_id,
1411 substs: tcx.mk_substs(self.principal.0.substs.with_self_ty(self_ty)),
1415 pub fn projection_bounds_with_self_ty(&self,
1418 -> Vec<ty::PolyProjectionPredicate<'tcx>>
1420 // otherwise the escaping regions would be captured by the binders
1421 assert!(!self_ty.has_escaping_regions());
1423 self.bounds.projection_bounds.iter()
1424 .map(|in_poly_projection_predicate| {
1425 let in_projection_ty = &in_poly_projection_predicate.0.projection_ty;
1426 let substs = tcx.mk_substs(in_projection_ty.trait_ref.substs.with_self_ty(self_ty));
1428 Rc::new(ty::TraitRef::new(in_projection_ty.trait_ref.def_id,
1430 let projection_ty = ty::ProjectionTy {
1431 trait_ref: trait_ref,
1432 item_name: in_projection_ty.item_name
1434 ty::Binder(ty::ProjectionPredicate {
1435 projection_ty: projection_ty,
1436 ty: in_poly_projection_predicate.0.ty
1443 /// A complete reference to a trait. These take numerous guises in syntax,
1444 /// but perhaps the most recognizable form is in a where clause:
1448 /// This would be represented by a trait-reference where the def-id is the
1449 /// def-id for the trait `Foo` and the substs defines `T` as parameter 0 in the
1450 /// `SelfSpace` and `U` as parameter 0 in the `TypeSpace`.
1452 /// Trait references also appear in object types like `Foo<U>`, but in
1453 /// that case the `Self` parameter is absent from the substitutions.
1455 /// Note that a `TraitRef` introduces a level of region binding, to
1456 /// account for higher-ranked trait bounds like `T : for<'a> Foo<&'a
1457 /// U>` or higher-ranked object types.
1458 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
1459 pub struct TraitRef<'tcx> {
1461 pub substs: &'tcx Substs<'tcx>,
1464 pub type PolyTraitRef<'tcx> = Binder<Rc<TraitRef<'tcx>>>;
1466 impl<'tcx> PolyTraitRef<'tcx> {
1467 pub fn self_ty(&self) -> Ty<'tcx> {
1471 pub fn def_id(&self) -> ast::DefId {
1475 pub fn substs(&self) -> &'tcx Substs<'tcx> {
1476 // FIXME(#20664) every use of this fn is probably a bug, it should yield Binder<>
1480 pub fn input_types(&self) -> &[Ty<'tcx>] {
1481 // FIXME(#20664) every use of this fn is probably a bug, it should yield Binder<>
1482 self.0.input_types()
1485 pub fn to_poly_trait_predicate(&self) -> PolyTraitPredicate<'tcx> {
1486 // Note that we preserve binding levels
1487 Binder(TraitPredicate { trait_ref: self.0.clone() })
1491 /// Binder is a binder for higher-ranked lifetimes. It is part of the
1492 /// compiler's representation for things like `for<'a> Fn(&'a int)`
1493 /// (which would be represented by the type `PolyTraitRef ==
1494 /// Binder<TraitRef>`). Note that when we skolemize, instantiate,
1495 /// erase, or otherwise "discharge" these bound regions, we change the
1496 /// type from `Binder<T>` to just `T` (see
1497 /// e.g. `liberate_late_bound_regions`).
1498 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
1499 pub struct Binder<T>(pub T);
1501 #[derive(Clone, Copy, PartialEq)]
1502 pub enum IntVarValue {
1503 IntType(ast::IntTy),
1504 UintType(ast::UintTy),
1507 #[derive(Clone, Copy, Debug)]
1508 pub enum terr_vstore_kind {
1515 #[derive(Clone, Copy, Debug)]
1516 pub struct expected_found<T> {
1521 // Data structures used in type unification
1522 #[derive(Clone, Copy, Debug)]
1523 pub enum type_err<'tcx> {
1525 terr_unsafety_mismatch(expected_found<ast::Unsafety>),
1526 terr_abi_mismatch(expected_found<abi::Abi>),
1528 terr_box_mutability,
1529 terr_ptr_mutability,
1530 terr_ref_mutability,
1531 terr_vec_mutability,
1532 terr_tuple_size(expected_found<uint>),
1533 terr_fixed_array_size(expected_found<uint>),
1534 terr_ty_param_size(expected_found<uint>),
1536 terr_regions_does_not_outlive(Region, Region),
1537 terr_regions_not_same(Region, Region),
1538 terr_regions_no_overlap(Region, Region),
1539 terr_regions_insufficiently_polymorphic(BoundRegion, Region),
1540 terr_regions_overly_polymorphic(BoundRegion, Region),
1541 terr_sorts(expected_found<Ty<'tcx>>),
1542 terr_integer_as_char,
1543 terr_int_mismatch(expected_found<IntVarValue>),
1544 terr_float_mismatch(expected_found<ast::FloatTy>),
1545 terr_traits(expected_found<ast::DefId>),
1546 terr_builtin_bounds(expected_found<BuiltinBounds>),
1547 terr_variadic_mismatch(expected_found<bool>),
1549 terr_convergence_mismatch(expected_found<bool>),
1550 terr_projection_name_mismatched(expected_found<ast::Name>),
1551 terr_projection_bounds_length(expected_found<uint>),
1554 /// Bounds suitable for a named type parameter like `A` in `fn foo<A>`
1555 /// as well as the existential type parameter in an object type.
1556 #[derive(PartialEq, Eq, Hash, Clone, Debug)]
1557 pub struct ParamBounds<'tcx> {
1558 pub region_bounds: Vec<ty::Region>,
1559 pub builtin_bounds: BuiltinBounds,
1560 pub trait_bounds: Vec<PolyTraitRef<'tcx>>,
1561 pub projection_bounds: Vec<PolyProjectionPredicate<'tcx>>,
1564 /// Bounds suitable for an existentially quantified type parameter
1565 /// such as those that appear in object types or closure types. The
1566 /// major difference between this case and `ParamBounds` is that
1567 /// general purpose trait bounds are omitted and there must be
1568 /// *exactly one* region.
1569 #[derive(PartialEq, Eq, Hash, Clone, Debug)]
1570 pub struct ExistentialBounds<'tcx> {
1571 pub region_bound: ty::Region,
1572 pub builtin_bounds: BuiltinBounds,
1573 pub projection_bounds: Vec<PolyProjectionPredicate<'tcx>>,
1576 pub type BuiltinBounds = EnumSet<BuiltinBound>;
1578 #[derive(Clone, RustcEncodable, PartialEq, Eq, RustcDecodable, Hash,
1581 pub enum BuiltinBound {
1588 pub fn empty_builtin_bounds() -> BuiltinBounds {
1592 pub fn all_builtin_bounds() -> BuiltinBounds {
1593 let mut set = EnumSet::new();
1594 set.insert(BoundSend);
1595 set.insert(BoundSized);
1596 set.insert(BoundSync);
1600 /// An existential bound that does not implement any traits.
1601 pub fn region_existential_bound<'tcx>(r: ty::Region) -> ExistentialBounds<'tcx> {
1602 ty::ExistentialBounds { region_bound: r,
1603 builtin_bounds: empty_builtin_bounds(),
1604 projection_bounds: Vec::new() }
1607 impl CLike for BuiltinBound {
1608 fn to_usize(&self) -> uint {
1611 fn from_usize(v: uint) -> BuiltinBound {
1612 unsafe { mem::transmute(v) }
1616 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1621 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1626 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1627 pub struct FloatVid {
1631 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
1632 pub struct RegionVid {
1636 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1642 /// A `FreshTy` is one that is generated as a replacement for an
1643 /// unbound type variable. This is convenient for caching etc. See
1644 /// `middle::infer::freshen` for more details.
1647 // FIXME -- once integral fallback is impl'd, we should remove
1648 // this type. It's only needed to prevent spurious errors for
1649 // integers whose type winds up never being constrained.
1653 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Debug, Copy)]
1654 pub enum UnconstrainedNumeric {
1661 #[derive(Clone, RustcEncodable, RustcDecodable, Eq, Hash, Debug, Copy)]
1662 pub enum InferRegion {
1664 ReSkolemized(u32, BoundRegion)
1667 impl cmp::PartialEq for InferRegion {
1668 fn eq(&self, other: &InferRegion) -> bool {
1669 match ((*self), *other) {
1670 (ReVar(rva), ReVar(rvb)) => {
1673 (ReSkolemized(rva, _), ReSkolemized(rvb, _)) => {
1679 fn ne(&self, other: &InferRegion) -> bool {
1680 !((*self) == (*other))
1684 impl fmt::Debug for TyVid {
1685 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result{
1686 write!(f, "_#{}t", self.index)
1690 impl fmt::Debug for IntVid {
1691 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1692 write!(f, "_#{}i", self.index)
1696 impl fmt::Debug for FloatVid {
1697 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1698 write!(f, "_#{}f", self.index)
1702 impl fmt::Debug for RegionVid {
1703 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1704 write!(f, "'_#{}r", self.index)
1708 impl<'tcx> fmt::Debug for FnSig<'tcx> {
1709 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1710 write!(f, "({:?}; variadic: {})->{:?}", self.inputs, self.variadic, self.output)
1714 impl fmt::Debug for InferTy {
1715 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1717 TyVar(ref v) => v.fmt(f),
1718 IntVar(ref v) => v.fmt(f),
1719 FloatVar(ref v) => v.fmt(f),
1720 FreshTy(v) => write!(f, "FreshTy({:?})", v),
1721 FreshIntTy(v) => write!(f, "FreshIntTy({:?})", v),
1726 impl fmt::Debug for IntVarValue {
1727 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1729 IntType(ref v) => v.fmt(f),
1730 UintType(ref v) => v.fmt(f),
1735 /// Default region to use for the bound of objects that are
1736 /// supplied as the value for this type parameter. This is derived
1737 /// from `T:'a` annotations appearing in the type definition. If
1738 /// this is `None`, then the default is inherited from the
1739 /// surrounding context. See RFC #599 for details.
1740 #[derive(Copy, Clone, Debug)]
1741 pub enum ObjectLifetimeDefault {
1742 /// Require an explicit annotation. Occurs when multiple
1743 /// `T:'a` constraints are found.
1746 /// Use the given region as the default.
1750 #[derive(Clone, Debug)]
1751 pub struct TypeParameterDef<'tcx> {
1752 pub name: ast::Name,
1753 pub def_id: ast::DefId,
1754 pub space: subst::ParamSpace,
1756 pub bounds: ParamBounds<'tcx>,
1757 pub default: Option<Ty<'tcx>>,
1758 pub object_lifetime_default: Option<ObjectLifetimeDefault>,
1761 #[derive(RustcEncodable, RustcDecodable, Clone, Debug)]
1762 pub struct RegionParameterDef {
1763 pub name: ast::Name,
1764 pub def_id: ast::DefId,
1765 pub space: subst::ParamSpace,
1767 pub bounds: Vec<ty::Region>,
1770 impl RegionParameterDef {
1771 pub fn to_early_bound_region(&self) -> ty::Region {
1772 ty::ReEarlyBound(self.def_id.node, self.space, self.index, self.name)
1776 /// Information about the formal type/lifetime parameters associated
1777 /// with an item or method. Analogous to ast::Generics.
1778 #[derive(Clone, Debug)]
1779 pub struct Generics<'tcx> {
1780 pub types: VecPerParamSpace<TypeParameterDef<'tcx>>,
1781 pub regions: VecPerParamSpace<RegionParameterDef>,
1784 impl<'tcx> Generics<'tcx> {
1785 pub fn empty() -> Generics<'tcx> {
1787 types: VecPerParamSpace::empty(),
1788 regions: VecPerParamSpace::empty(),
1792 pub fn is_empty(&self) -> bool {
1793 self.types.is_empty() && self.regions.is_empty()
1796 pub fn has_type_params(&self, space: subst::ParamSpace) -> bool {
1797 !self.types.is_empty_in(space)
1800 pub fn has_region_params(&self, space: subst::ParamSpace) -> bool {
1801 !self.regions.is_empty_in(space)
1805 /// Bounds on generics.
1806 #[derive(Clone, Debug)]
1807 pub struct GenericPredicates<'tcx> {
1808 pub predicates: VecPerParamSpace<Predicate<'tcx>>,
1811 impl<'tcx> GenericPredicates<'tcx> {
1812 pub fn empty() -> GenericPredicates<'tcx> {
1814 predicates: VecPerParamSpace::empty(),
1818 pub fn instantiate(&self, tcx: &ty::ctxt<'tcx>, substs: &Substs<'tcx>)
1819 -> InstantiatedPredicates<'tcx> {
1820 InstantiatedPredicates {
1821 predicates: self.predicates.subst(tcx, substs),
1826 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
1827 pub enum Predicate<'tcx> {
1828 /// Corresponds to `where Foo : Bar<A,B,C>`. `Foo` here would be
1829 /// the `Self` type of the trait reference and `A`, `B`, and `C`
1830 /// would be the parameters in the `TypeSpace`.
1831 Trait(PolyTraitPredicate<'tcx>),
1833 /// where `T1 == T2`.
1834 Equate(PolyEquatePredicate<'tcx>),
1837 RegionOutlives(PolyRegionOutlivesPredicate),
1840 TypeOutlives(PolyTypeOutlivesPredicate<'tcx>),
1842 /// where <T as TraitRef>::Name == X, approximately.
1843 /// See `ProjectionPredicate` struct for details.
1844 Projection(PolyProjectionPredicate<'tcx>),
1847 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
1848 pub struct TraitPredicate<'tcx> {
1849 pub trait_ref: Rc<TraitRef<'tcx>>
1851 pub type PolyTraitPredicate<'tcx> = ty::Binder<TraitPredicate<'tcx>>;
1853 impl<'tcx> TraitPredicate<'tcx> {
1854 pub fn def_id(&self) -> ast::DefId {
1855 self.trait_ref.def_id
1858 pub fn input_types(&self) -> &[Ty<'tcx>] {
1859 self.trait_ref.substs.types.as_slice()
1862 pub fn self_ty(&self) -> Ty<'tcx> {
1863 self.trait_ref.self_ty()
1867 impl<'tcx> PolyTraitPredicate<'tcx> {
1868 pub fn def_id(&self) -> ast::DefId {
1873 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
1874 pub struct EquatePredicate<'tcx>(pub Ty<'tcx>, pub Ty<'tcx>); // `0 == 1`
1875 pub type PolyEquatePredicate<'tcx> = ty::Binder<EquatePredicate<'tcx>>;
1877 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
1878 pub struct OutlivesPredicate<A,B>(pub A, pub B); // `A : B`
1879 pub type PolyOutlivesPredicate<A,B> = ty::Binder<OutlivesPredicate<A,B>>;
1880 pub type PolyRegionOutlivesPredicate = PolyOutlivesPredicate<ty::Region, ty::Region>;
1881 pub type PolyTypeOutlivesPredicate<'tcx> = PolyOutlivesPredicate<Ty<'tcx>, ty::Region>;
1883 /// This kind of predicate has no *direct* correspondent in the
1884 /// syntax, but it roughly corresponds to the syntactic forms:
1886 /// 1. `T : TraitRef<..., Item=Type>`
1887 /// 2. `<T as TraitRef<...>>::Item == Type` (NYI)
1889 /// In particular, form #1 is "desugared" to the combination of a
1890 /// normal trait predicate (`T : TraitRef<...>`) and one of these
1891 /// predicates. Form #2 is a broader form in that it also permits
1892 /// equality between arbitrary types. Processing an instance of Form
1893 /// #2 eventually yields one of these `ProjectionPredicate`
1894 /// instances to normalize the LHS.
1895 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
1896 pub struct ProjectionPredicate<'tcx> {
1897 pub projection_ty: ProjectionTy<'tcx>,
1901 pub type PolyProjectionPredicate<'tcx> = Binder<ProjectionPredicate<'tcx>>;
1903 impl<'tcx> PolyProjectionPredicate<'tcx> {
1904 pub fn item_name(&self) -> ast::Name {
1905 self.0.projection_ty.item_name // safe to skip the binder to access a name
1908 pub fn sort_key(&self) -> (ast::DefId, ast::Name) {
1909 self.0.projection_ty.sort_key()
1913 /// Represents the projection of an associated type. In explicit UFCS
1914 /// form this would be written `<T as Trait<..>>::N`.
1915 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
1916 pub struct ProjectionTy<'tcx> {
1917 /// The trait reference `T as Trait<..>`.
1918 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
1920 /// The name `N` of the associated type.
1921 pub item_name: ast::Name,
1924 impl<'tcx> ProjectionTy<'tcx> {
1925 pub fn sort_key(&self) -> (ast::DefId, ast::Name) {
1926 (self.trait_ref.def_id, self.item_name)
1930 pub trait ToPolyTraitRef<'tcx> {
1931 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx>;
1934 impl<'tcx> ToPolyTraitRef<'tcx> for Rc<TraitRef<'tcx>> {
1935 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1936 assert!(!self.has_escaping_regions());
1937 ty::Binder(self.clone())
1941 impl<'tcx> ToPolyTraitRef<'tcx> for PolyTraitPredicate<'tcx> {
1942 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1943 // We are just preserving the binder levels here
1944 ty::Binder(self.0.trait_ref.clone())
1948 impl<'tcx> ToPolyTraitRef<'tcx> for PolyProjectionPredicate<'tcx> {
1949 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1950 // Note: unlike with TraitRef::to_poly_trait_ref(),
1951 // self.0.trait_ref is permitted to have escaping regions.
1952 // This is because here `self` has a `Binder` and so does our
1953 // return value, so we are preserving the number of binding
1955 ty::Binder(self.0.projection_ty.trait_ref.clone())
1959 pub trait AsPredicate<'tcx> {
1960 fn as_predicate(&self) -> Predicate<'tcx>;
1963 impl<'tcx> AsPredicate<'tcx> for Rc<TraitRef<'tcx>> {
1964 fn as_predicate(&self) -> Predicate<'tcx> {
1965 // we're about to add a binder, so let's check that we don't
1966 // accidentally capture anything, or else that might be some
1967 // weird debruijn accounting.
1968 assert!(!self.has_escaping_regions());
1970 ty::Predicate::Trait(ty::Binder(ty::TraitPredicate {
1971 trait_ref: self.clone()
1976 impl<'tcx> AsPredicate<'tcx> for PolyTraitRef<'tcx> {
1977 fn as_predicate(&self) -> Predicate<'tcx> {
1978 ty::Predicate::Trait(self.to_poly_trait_predicate())
1982 impl<'tcx> AsPredicate<'tcx> for PolyEquatePredicate<'tcx> {
1983 fn as_predicate(&self) -> Predicate<'tcx> {
1984 Predicate::Equate(self.clone())
1988 impl<'tcx> AsPredicate<'tcx> for PolyRegionOutlivesPredicate {
1989 fn as_predicate(&self) -> Predicate<'tcx> {
1990 Predicate::RegionOutlives(self.clone())
1994 impl<'tcx> AsPredicate<'tcx> for PolyTypeOutlivesPredicate<'tcx> {
1995 fn as_predicate(&self) -> Predicate<'tcx> {
1996 Predicate::TypeOutlives(self.clone())
2000 impl<'tcx> AsPredicate<'tcx> for PolyProjectionPredicate<'tcx> {
2001 fn as_predicate(&self) -> Predicate<'tcx> {
2002 Predicate::Projection(self.clone())
2006 impl<'tcx> Predicate<'tcx> {
2007 pub fn has_escaping_regions(&self) -> bool {
2009 Predicate::Trait(ref trait_ref) => trait_ref.has_escaping_regions(),
2010 Predicate::Equate(ref p) => p.has_escaping_regions(),
2011 Predicate::RegionOutlives(ref p) => p.has_escaping_regions(),
2012 Predicate::TypeOutlives(ref p) => p.has_escaping_regions(),
2013 Predicate::Projection(ref p) => p.has_escaping_regions(),
2017 pub fn to_opt_poly_trait_ref(&self) -> Option<PolyTraitRef<'tcx>> {
2019 Predicate::Trait(ref t) => {
2020 Some(t.to_poly_trait_ref())
2022 Predicate::Projection(..) |
2023 Predicate::Equate(..) |
2024 Predicate::RegionOutlives(..) |
2025 Predicate::TypeOutlives(..) => {
2032 /// Represents the bounds declared on a particular set of type
2033 /// parameters. Should eventually be generalized into a flag list of
2034 /// where clauses. You can obtain a `InstantiatedPredicates` list from a
2035 /// `GenericPredicates` by using the `instantiate` method. Note that this method
2036 /// reflects an important semantic invariant of `InstantiatedPredicates`: while
2037 /// the `GenericPredicates` are expressed in terms of the bound type
2038 /// parameters of the impl/trait/whatever, an `InstantiatedPredicates` instance
2039 /// represented a set of bounds for some particular instantiation,
2040 /// meaning that the generic parameters have been substituted with
2045 /// struct Foo<T,U:Bar<T>> { ... }
2047 /// Here, the `GenericPredicates` for `Foo` would contain a list of bounds like
2048 /// `[[], [U:Bar<T>]]`. Now if there were some particular reference
2049 /// like `Foo<int,uint>`, then the `InstantiatedPredicates` would be `[[],
2050 /// [uint:Bar<int>]]`.
2051 #[derive(Clone, Debug)]
2052 pub struct InstantiatedPredicates<'tcx> {
2053 pub predicates: VecPerParamSpace<Predicate<'tcx>>,
2056 impl<'tcx> InstantiatedPredicates<'tcx> {
2057 pub fn empty() -> InstantiatedPredicates<'tcx> {
2058 InstantiatedPredicates { predicates: VecPerParamSpace::empty() }
2061 pub fn has_escaping_regions(&self) -> bool {
2062 self.predicates.any(|p| p.has_escaping_regions())
2065 pub fn is_empty(&self) -> bool {
2066 self.predicates.is_empty()
2070 impl<'tcx> TraitRef<'tcx> {
2071 pub fn new(def_id: ast::DefId, substs: &'tcx Substs<'tcx>) -> TraitRef<'tcx> {
2072 TraitRef { def_id: def_id, substs: substs }
2075 pub fn self_ty(&self) -> Ty<'tcx> {
2076 self.substs.self_ty().unwrap()
2079 pub fn input_types(&self) -> &[Ty<'tcx>] {
2080 // Select only the "input types" from a trait-reference. For
2081 // now this is all the types that appear in the
2082 // trait-reference, but it should eventually exclude
2083 // associated types.
2084 self.substs.types.as_slice()
2088 /// When type checking, we use the `ParameterEnvironment` to track
2089 /// details about the type/lifetime parameters that are in scope.
2090 /// It primarily stores the bounds information.
2092 /// Note: This information might seem to be redundant with the data in
2093 /// `tcx.ty_param_defs`, but it is not. That table contains the
2094 /// parameter definitions from an "outside" perspective, but this
2095 /// struct will contain the bounds for a parameter as seen from inside
2096 /// the function body. Currently the only real distinction is that
2097 /// bound lifetime parameters are replaced with free ones, but in the
2098 /// future I hope to refine the representation of types so as to make
2099 /// more distinctions clearer.
2101 pub struct ParameterEnvironment<'a, 'tcx:'a> {
2102 pub tcx: &'a ctxt<'tcx>,
2104 /// See `construct_free_substs` for details.
2105 pub free_substs: Substs<'tcx>,
2107 /// Each type parameter has an implicit region bound that
2108 /// indicates it must outlive at least the function body (the user
2109 /// may specify stronger requirements). This field indicates the
2110 /// region of the callee.
2111 pub implicit_region_bound: ty::Region,
2113 /// Obligations that the caller must satisfy. This is basically
2114 /// the set of bounds on the in-scope type parameters, translated
2115 /// into Obligations.
2116 pub caller_bounds: Vec<ty::Predicate<'tcx>>,
2118 /// Caches the results of trait selection. This cache is used
2119 /// for things that have to do with the parameters in scope.
2120 pub selection_cache: traits::SelectionCache<'tcx>,
2123 impl<'a, 'tcx> ParameterEnvironment<'a, 'tcx> {
2124 pub fn with_caller_bounds(&self,
2125 caller_bounds: Vec<ty::Predicate<'tcx>>)
2126 -> ParameterEnvironment<'a,'tcx>
2128 ParameterEnvironment {
2130 free_substs: self.free_substs.clone(),
2131 implicit_region_bound: self.implicit_region_bound,
2132 caller_bounds: caller_bounds,
2133 selection_cache: traits::SelectionCache::new(),
2137 pub fn for_item(cx: &'a ctxt<'tcx>, id: NodeId) -> ParameterEnvironment<'a, 'tcx> {
2138 match cx.map.find(id) {
2139 Some(ast_map::NodeImplItem(ref impl_item)) => {
2141 ast::MethodImplItem(ref method) => {
2142 let method_def_id = ast_util::local_def(id);
2143 match ty::impl_or_trait_item(cx, method_def_id) {
2144 MethodTraitItem(ref method_ty) => {
2145 let method_generics = &method_ty.generics;
2146 let method_bounds = &method_ty.predicates;
2147 construct_parameter_environment(
2152 method.pe_body().id)
2154 TypeTraitItem(_) => {
2156 .bug("ParameterEnvironment::for_item(): \
2157 can't create a parameter environment \
2158 for type trait items")
2162 ast::TypeImplItem(_) => {
2163 cx.sess.bug("ParameterEnvironment::for_item(): \
2164 can't create a parameter environment \
2165 for type impl items")
2169 Some(ast_map::NodeTraitItem(trait_method)) => {
2170 match *trait_method {
2171 ast::RequiredMethod(ref required) => {
2172 cx.sess.span_bug(required.span,
2173 "ParameterEnvironment::for_item():
2174 can't create a parameter \
2175 environment for required trait \
2178 ast::ProvidedMethod(ref method) => {
2179 let method_def_id = ast_util::local_def(id);
2180 match ty::impl_or_trait_item(cx, method_def_id) {
2181 MethodTraitItem(ref method_ty) => {
2182 let method_generics = &method_ty.generics;
2183 let method_bounds = &method_ty.predicates;
2184 construct_parameter_environment(
2189 method.pe_body().id)
2191 TypeTraitItem(_) => {
2193 .bug("ParameterEnvironment::for_item(): \
2194 can't create a parameter environment \
2195 for type trait items")
2199 ast::TypeTraitItem(_) => {
2200 cx.sess.bug("ParameterEnvironment::from_item(): \
2201 can't create a parameter environment \
2202 for type trait items")
2206 Some(ast_map::NodeItem(item)) => {
2208 ast::ItemFn(_, _, _, _, ref body) => {
2209 // We assume this is a function.
2210 let fn_def_id = ast_util::local_def(id);
2211 let fn_scheme = lookup_item_type(cx, fn_def_id);
2212 let fn_predicates = lookup_predicates(cx, fn_def_id);
2214 construct_parameter_environment(cx,
2216 &fn_scheme.generics,
2221 ast::ItemStruct(..) |
2223 ast::ItemConst(..) |
2224 ast::ItemStatic(..) => {
2225 let def_id = ast_util::local_def(id);
2226 let scheme = lookup_item_type(cx, def_id);
2227 let predicates = lookup_predicates(cx, def_id);
2228 construct_parameter_environment(cx,
2235 cx.sess.span_bug(item.span,
2236 "ParameterEnvironment::from_item():
2237 can't create a parameter \
2238 environment for this kind of item")
2242 Some(ast_map::NodeExpr(..)) => {
2243 // This is a convenience to allow closures to work.
2244 ParameterEnvironment::for_item(cx, cx.map.get_parent(id))
2247 cx.sess.bug(&format!("ParameterEnvironment::from_item(): \
2248 `{}` is not an item",
2249 cx.map.node_to_string(id))[])
2255 /// A "type scheme", in ML terminology, is a type combined with some
2256 /// set of generic types that the type is, well, generic over. In Rust
2257 /// terms, it is the "type" of a fn item or struct -- this type will
2258 /// include various generic parameters that must be substituted when
2259 /// the item/struct is referenced. That is called converting the type
2260 /// scheme to a monotype.
2262 /// - `generics`: the set of type parameters and their bounds
2263 /// - `ty`: the base types, which may reference the parameters defined
2266 /// Note that TypeSchemes are also sometimes called "polytypes" (and
2267 /// in fact this struct used to carry that name, so you may find some
2268 /// stray references in a comment or something). We try to reserve the
2269 /// "poly" prefix to refer to higher-ranked things, as in
2272 /// Note that each item also comes with predicates, see
2273 /// `lookup_predicates`.
2274 #[derive(Clone, Debug)]
2275 pub struct TypeScheme<'tcx> {
2276 pub generics: Generics<'tcx>,
2280 /// As `TypeScheme` but for a trait ref.
2281 pub struct TraitDef<'tcx> {
2282 pub unsafety: ast::Unsafety,
2284 /// If `true`, then this trait had the `#[rustc_paren_sugar]`
2285 /// attribute, indicating that it should be used with `Foo()`
2286 /// sugar. This is a temporary thing -- eventually any trait wil
2287 /// be usable with the sugar (or without it).
2288 pub paren_sugar: bool,
2290 /// Generic type definitions. Note that `Self` is listed in here
2291 /// as having a single bound, the trait itself (e.g., in the trait
2292 /// `Eq`, there is a single bound `Self : Eq`). This is so that
2293 /// default methods get to assume that the `Self` parameters
2294 /// implements the trait.
2295 pub generics: Generics<'tcx>,
2297 /// The "supertrait" bounds.
2298 pub bounds: ParamBounds<'tcx>,
2300 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
2302 /// A list of the associated types defined in this trait. Useful
2303 /// for resolving `X::Foo` type markers.
2304 pub associated_type_names: Vec<ast::Name>,
2307 /// Records the substitutions used to translate the polytype for an
2308 /// item into the monotype of an item reference.
2310 pub struct ItemSubsts<'tcx> {
2311 pub substs: Substs<'tcx>,
2314 #[derive(Clone, Copy, PartialEq, Eq, Debug, RustcEncodable, RustcDecodable)]
2315 pub enum ClosureKind {
2322 pub fn trait_did(&self, cx: &ctxt) -> ast::DefId {
2323 let result = match *self {
2324 FnClosureKind => cx.lang_items.require(FnTraitLangItem),
2325 FnMutClosureKind => {
2326 cx.lang_items.require(FnMutTraitLangItem)
2328 FnOnceClosureKind => {
2329 cx.lang_items.require(FnOnceTraitLangItem)
2333 Ok(trait_did) => trait_did,
2334 Err(err) => cx.sess.fatal(&err[]),
2339 pub trait ClosureTyper<'tcx> {
2340 fn tcx(&self) -> &ty::ctxt<'tcx> {
2341 self.param_env().tcx
2344 fn param_env<'a>(&'a self) -> &'a ty::ParameterEnvironment<'a, 'tcx>;
2346 /// Is this a `Fn`, `FnMut` or `FnOnce` closure? During typeck,
2347 /// returns `None` if the kind of this closure has not yet been
2349 fn closure_kind(&self,
2351 -> Option<ty::ClosureKind>;
2353 /// Returns the argument/return types of this closure.
2354 fn closure_type(&self,
2356 substs: &subst::Substs<'tcx>)
2357 -> ty::ClosureTy<'tcx>;
2359 /// Returns the set of all upvars and their transformed
2360 /// types. During typeck, maybe return `None` if the upvar types
2361 /// have not yet been inferred.
2362 fn closure_upvars(&self,
2364 substs: &Substs<'tcx>)
2365 -> Option<Vec<ClosureUpvar<'tcx>>>;
2368 impl<'tcx> CommonTypes<'tcx> {
2369 fn new(arena: &'tcx TypedArena<TyS<'tcx>>,
2370 interner: &mut FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>)
2371 -> CommonTypes<'tcx>
2374 bool: intern_ty(arena, interner, ty_bool),
2375 char: intern_ty(arena, interner, ty_char),
2376 err: intern_ty(arena, interner, ty_err),
2377 int: intern_ty(arena, interner, ty_int(ast::TyIs(false))),
2378 i8: intern_ty(arena, interner, ty_int(ast::TyI8)),
2379 i16: intern_ty(arena, interner, ty_int(ast::TyI16)),
2380 i32: intern_ty(arena, interner, ty_int(ast::TyI32)),
2381 i64: intern_ty(arena, interner, ty_int(ast::TyI64)),
2382 uint: intern_ty(arena, interner, ty_uint(ast::TyUs(false))),
2383 u8: intern_ty(arena, interner, ty_uint(ast::TyU8)),
2384 u16: intern_ty(arena, interner, ty_uint(ast::TyU16)),
2385 u32: intern_ty(arena, interner, ty_uint(ast::TyU32)),
2386 u64: intern_ty(arena, interner, ty_uint(ast::TyU64)),
2387 f32: intern_ty(arena, interner, ty_float(ast::TyF32)),
2388 f64: intern_ty(arena, interner, ty_float(ast::TyF64)),
2393 pub fn mk_ctxt<'tcx>(s: Session,
2394 arenas: &'tcx CtxtArenas<'tcx>,
2396 named_region_map: resolve_lifetime::NamedRegionMap,
2397 map: ast_map::Map<'tcx>,
2398 freevars: RefCell<FreevarMap>,
2399 region_maps: middle::region::RegionMaps,
2400 lang_items: middle::lang_items::LanguageItems,
2401 stability: stability::Index) -> ctxt<'tcx>
2403 let mut interner = FnvHashMap();
2404 let common_types = CommonTypes::new(&arenas.type_, &mut interner);
2408 interner: RefCell::new(interner),
2409 substs_interner: RefCell::new(FnvHashMap()),
2410 bare_fn_interner: RefCell::new(FnvHashMap()),
2411 region_interner: RefCell::new(FnvHashMap()),
2412 types: common_types,
2413 named_region_map: named_region_map,
2414 item_variance_map: RefCell::new(DefIdMap()),
2415 variance_computed: Cell::new(false),
2418 region_maps: region_maps,
2419 node_types: RefCell::new(FnvHashMap()),
2420 item_substs: RefCell::new(NodeMap()),
2421 trait_refs: RefCell::new(NodeMap()),
2422 trait_defs: RefCell::new(DefIdMap()),
2423 predicates: RefCell::new(DefIdMap()),
2424 object_cast_map: RefCell::new(NodeMap()),
2426 intrinsic_defs: RefCell::new(DefIdMap()),
2428 tcache: RefCell::new(DefIdMap()),
2429 rcache: RefCell::new(FnvHashMap()),
2430 short_names_cache: RefCell::new(FnvHashMap()),
2431 tc_cache: RefCell::new(FnvHashMap()),
2432 ast_ty_to_ty_cache: RefCell::new(NodeMap()),
2433 enum_var_cache: RefCell::new(DefIdMap()),
2434 impl_or_trait_items: RefCell::new(DefIdMap()),
2435 trait_item_def_ids: RefCell::new(DefIdMap()),
2436 trait_items_cache: RefCell::new(DefIdMap()),
2437 impl_trait_cache: RefCell::new(DefIdMap()),
2438 ty_param_defs: RefCell::new(NodeMap()),
2439 adjustments: RefCell::new(NodeMap()),
2440 normalized_cache: RefCell::new(FnvHashMap()),
2441 lang_items: lang_items,
2442 provided_method_sources: RefCell::new(DefIdMap()),
2443 struct_fields: RefCell::new(DefIdMap()),
2444 destructor_for_type: RefCell::new(DefIdMap()),
2445 destructors: RefCell::new(DefIdSet()),
2446 trait_impls: RefCell::new(DefIdMap()),
2447 inherent_impls: RefCell::new(DefIdMap()),
2448 impl_items: RefCell::new(DefIdMap()),
2449 used_unsafe: RefCell::new(NodeSet()),
2450 used_mut_nodes: RefCell::new(NodeSet()),
2451 populated_external_types: RefCell::new(DefIdSet()),
2452 populated_external_traits: RefCell::new(DefIdSet()),
2453 upvar_capture_map: RefCell::new(FnvHashMap()),
2454 extern_const_statics: RefCell::new(DefIdMap()),
2455 extern_const_variants: RefCell::new(DefIdMap()),
2456 method_map: RefCell::new(FnvHashMap()),
2457 dependency_formats: RefCell::new(FnvHashMap()),
2458 closure_kinds: RefCell::new(DefIdMap()),
2459 closure_tys: RefCell::new(DefIdMap()),
2460 node_lint_levels: RefCell::new(FnvHashMap()),
2461 transmute_restrictions: RefCell::new(Vec::new()),
2462 stability: RefCell::new(stability),
2463 associated_types: RefCell::new(DefIdMap()),
2464 selection_cache: traits::SelectionCache::new(),
2465 repr_hint_cache: RefCell::new(DefIdMap()),
2466 type_impls_copy_cache: RefCell::new(HashMap::new()),
2467 type_impls_sized_cache: RefCell::new(HashMap::new()),
2468 object_safety_cache: RefCell::new(DefIdMap()),
2469 const_qualif_map: RefCell::new(NodeMap()),
2473 // Type constructors
2475 impl<'tcx> ctxt<'tcx> {
2476 pub fn mk_substs(&self, substs: Substs<'tcx>) -> &'tcx Substs<'tcx> {
2477 if let Some(substs) = self.substs_interner.borrow().get(&substs) {
2481 let substs = self.arenas.substs.alloc(substs);
2482 self.substs_interner.borrow_mut().insert(substs, substs);
2486 pub fn mk_bare_fn(&self, bare_fn: BareFnTy<'tcx>) -> &'tcx BareFnTy<'tcx> {
2487 if let Some(bare_fn) = self.bare_fn_interner.borrow().get(&bare_fn) {
2491 let bare_fn = self.arenas.bare_fn.alloc(bare_fn);
2492 self.bare_fn_interner.borrow_mut().insert(bare_fn, bare_fn);
2496 pub fn mk_region(&self, region: Region) -> &'tcx Region {
2497 if let Some(region) = self.region_interner.borrow().get(®ion) {
2501 let region = self.arenas.region.alloc(region);
2502 self.region_interner.borrow_mut().insert(region, region);
2506 pub fn closure_kind(&self, def_id: ast::DefId) -> ty::ClosureKind {
2507 self.closure_kinds.borrow()[def_id]
2510 pub fn closure_type(&self,
2512 substs: &subst::Substs<'tcx>)
2513 -> ty::ClosureTy<'tcx>
2515 self.closure_tys.borrow()[def_id].subst(self, substs)
2519 // Interns a type/name combination, stores the resulting box in cx.interner,
2520 // and returns the box as cast to an unsafe ptr (see comments for Ty above).
2521 pub fn mk_t<'tcx>(cx: &ctxt<'tcx>, st: sty<'tcx>) -> Ty<'tcx> {
2522 let mut interner = cx.interner.borrow_mut();
2523 intern_ty(&cx.arenas.type_, &mut *interner, st)
2526 fn intern_ty<'tcx>(type_arena: &'tcx TypedArena<TyS<'tcx>>,
2527 interner: &mut FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>,
2531 match interner.get(&st) {
2532 Some(ty) => return *ty,
2536 let flags = FlagComputation::for_sty(&st);
2539 () => type_arena.alloc(TyS { sty: st,
2541 region_depth: flags.depth, }),
2544 debug!("Interned type: {:?} Pointer: {:?}",
2545 ty, ty as *const _);
2547 interner.insert(InternedTy { ty: ty }, ty);
2552 struct FlagComputation {
2555 // maximum depth of any bound region that we have seen thus far
2559 impl FlagComputation {
2560 fn new() -> FlagComputation {
2561 FlagComputation { flags: NO_TYPE_FLAGS, depth: 0 }
2564 fn for_sty(st: &sty) -> FlagComputation {
2565 let mut result = FlagComputation::new();
2570 fn add_flags(&mut self, flags: TypeFlags) {
2571 self.flags = self.flags | flags;
2574 fn add_depth(&mut self, depth: u32) {
2575 if depth > self.depth {
2580 /// Adds the flags/depth from a set of types that appear within the current type, but within a
2582 fn add_bound_computation(&mut self, computation: &FlagComputation) {
2583 self.add_flags(computation.flags);
2585 // The types that contributed to `computation` occurred within
2586 // a region binder, so subtract one from the region depth
2587 // within when adding the depth to `self`.
2588 let depth = computation.depth;
2590 self.add_depth(depth - 1);
2594 fn add_sty(&mut self, st: &sty) {
2604 // You might think that we could just return ty_err for
2605 // any type containing ty_err as a component, and get
2606 // rid of the HAS_TY_ERR flag -- likewise for ty_bot (with
2607 // the exception of function types that return bot).
2608 // But doing so caused sporadic memory corruption, and
2609 // neither I (tjc) nor nmatsakis could figure out why,
2610 // so we're doing it this way.
2612 self.add_flags(HAS_TY_ERR)
2615 &ty_param(ref p) => {
2616 if p.space == subst::SelfSpace {
2617 self.add_flags(HAS_SELF);
2619 self.add_flags(HAS_PARAMS);
2623 &ty_closure(_, region, substs) => {
2624 self.add_region(*region);
2625 self.add_substs(substs);
2629 self.add_flags(HAS_TY_INFER)
2632 &ty_enum(_, substs) | &ty_struct(_, substs) => {
2633 self.add_substs(substs);
2636 &ty_projection(ref data) => {
2637 self.add_flags(HAS_PROJECTION);
2638 self.add_projection_ty(data);
2641 &ty_trait(box TyTrait { ref principal, ref bounds }) => {
2642 let mut computation = FlagComputation::new();
2643 computation.add_substs(principal.0.substs);
2644 for projection_bound in &bounds.projection_bounds {
2645 let mut proj_computation = FlagComputation::new();
2646 proj_computation.add_projection_predicate(&projection_bound.0);
2647 computation.add_bound_computation(&proj_computation);
2649 self.add_bound_computation(&computation);
2651 self.add_bounds(bounds);
2654 &ty_uniq(tt) | &ty_vec(tt, _) | &ty_open(tt) => {
2662 &ty_rptr(r, ref m) => {
2663 self.add_region(*r);
2667 &ty_tup(ref ts) => {
2668 self.add_tys(&ts[]);
2671 &ty_bare_fn(_, ref f) => {
2672 self.add_fn_sig(&f.sig);
2677 fn add_ty(&mut self, ty: Ty) {
2678 self.add_flags(ty.flags);
2679 self.add_depth(ty.region_depth);
2682 fn add_tys(&mut self, tys: &[Ty]) {
2688 fn add_fn_sig(&mut self, fn_sig: &PolyFnSig) {
2689 let mut computation = FlagComputation::new();
2691 computation.add_tys(&fn_sig.0.inputs[]);
2693 if let ty::FnConverging(output) = fn_sig.0.output {
2694 computation.add_ty(output);
2697 self.add_bound_computation(&computation);
2700 fn add_region(&mut self, r: Region) {
2701 self.add_flags(HAS_REGIONS);
2703 ty::ReInfer(_) => { self.add_flags(HAS_RE_INFER); }
2704 ty::ReLateBound(debruijn, _) => {
2705 self.add_flags(HAS_RE_LATE_BOUND);
2706 self.add_depth(debruijn.depth);
2712 fn add_projection_predicate(&mut self, projection_predicate: &ProjectionPredicate) {
2713 self.add_projection_ty(&projection_predicate.projection_ty);
2714 self.add_ty(projection_predicate.ty);
2717 fn add_projection_ty(&mut self, projection_ty: &ProjectionTy) {
2718 self.add_substs(projection_ty.trait_ref.substs);
2721 fn add_substs(&mut self, substs: &Substs) {
2722 self.add_tys(substs.types.as_slice());
2723 match substs.regions {
2724 subst::ErasedRegions => {}
2725 subst::NonerasedRegions(ref regions) => {
2726 for &r in regions.iter() {
2733 fn add_bounds(&mut self, bounds: &ExistentialBounds) {
2734 self.add_region(bounds.region_bound);
2738 pub fn mk_mach_int<'tcx>(tcx: &ctxt<'tcx>, tm: ast::IntTy) -> Ty<'tcx> {
2740 ast::TyIs(_) => tcx.types.int,
2741 ast::TyI8 => tcx.types.i8,
2742 ast::TyI16 => tcx.types.i16,
2743 ast::TyI32 => tcx.types.i32,
2744 ast::TyI64 => tcx.types.i64,
2748 pub fn mk_mach_uint<'tcx>(tcx: &ctxt<'tcx>, tm: ast::UintTy) -> Ty<'tcx> {
2750 ast::TyUs(_) => tcx.types.uint,
2751 ast::TyU8 => tcx.types.u8,
2752 ast::TyU16 => tcx.types.u16,
2753 ast::TyU32 => tcx.types.u32,
2754 ast::TyU64 => tcx.types.u64,
2758 pub fn mk_mach_float<'tcx>(tcx: &ctxt<'tcx>, tm: ast::FloatTy) -> Ty<'tcx> {
2760 ast::TyF32 => tcx.types.f32,
2761 ast::TyF64 => tcx.types.f64,
2765 pub fn mk_str<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2769 pub fn mk_str_slice<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, m: ast::Mutability) -> Ty<'tcx> {
2772 ty: mk_t(cx, ty_str),
2777 pub fn mk_enum<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId, substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
2778 // take a copy of substs so that we own the vectors inside
2779 mk_t(cx, ty_enum(did, substs))
2782 pub fn mk_uniq<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_uniq(ty)) }
2784 pub fn mk_ptr<'tcx>(cx: &ctxt<'tcx>, tm: mt<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_ptr(tm)) }
2786 pub fn mk_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, tm: mt<'tcx>) -> Ty<'tcx> {
2787 mk_t(cx, ty_rptr(r, tm))
2790 pub fn mk_mut_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
2791 mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutMutable})
2793 pub fn mk_imm_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
2794 mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutImmutable})
2797 pub fn mk_mut_ptr<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
2798 mk_ptr(cx, mt {ty: ty, mutbl: ast::MutMutable})
2801 pub fn mk_imm_ptr<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
2802 mk_ptr(cx, mt {ty: ty, mutbl: ast::MutImmutable})
2805 pub fn mk_nil_ptr<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2806 mk_ptr(cx, mt {ty: mk_nil(cx), mutbl: ast::MutImmutable})
2809 pub fn mk_vec<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>, sz: Option<uint>) -> Ty<'tcx> {
2810 mk_t(cx, ty_vec(ty, sz))
2813 pub fn mk_slice<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, tm: mt<'tcx>) -> Ty<'tcx> {
2816 ty: mk_vec(cx, tm.ty, None),
2821 pub fn mk_tup<'tcx>(cx: &ctxt<'tcx>, ts: Vec<Ty<'tcx>>) -> Ty<'tcx> {
2822 mk_t(cx, ty_tup(ts))
2825 pub fn mk_nil<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2826 mk_tup(cx, Vec::new())
2829 pub fn mk_bare_fn<'tcx>(cx: &ctxt<'tcx>,
2830 opt_def_id: Option<ast::DefId>,
2831 fty: &'tcx BareFnTy<'tcx>) -> Ty<'tcx> {
2832 mk_t(cx, ty_bare_fn(opt_def_id, fty))
2835 pub fn mk_ctor_fn<'tcx>(cx: &ctxt<'tcx>,
2837 input_tys: &[Ty<'tcx>],
2838 output: Ty<'tcx>) -> Ty<'tcx> {
2839 let input_args = input_tys.iter().map(|ty| *ty).collect();
2842 cx.mk_bare_fn(BareFnTy {
2843 unsafety: ast::Unsafety::Normal,
2845 sig: ty::Binder(FnSig {
2847 output: ty::FnConverging(output),
2853 pub fn mk_trait<'tcx>(cx: &ctxt<'tcx>,
2854 principal: ty::PolyTraitRef<'tcx>,
2855 bounds: ExistentialBounds<'tcx>)
2858 assert!(bound_list_is_sorted(&bounds.projection_bounds));
2860 let inner = box TyTrait {
2861 principal: principal,
2864 mk_t(cx, ty_trait(inner))
2867 fn bound_list_is_sorted(bounds: &[ty::PolyProjectionPredicate]) -> bool {
2868 bounds.len() == 0 ||
2869 bounds[1..].iter().enumerate().all(
2870 |(index, bound)| bounds[index].sort_key() <= bound.sort_key())
2873 pub fn sort_bounds_list(bounds: &mut [ty::PolyProjectionPredicate]) {
2874 bounds.sort_by(|a, b| a.sort_key().cmp(&b.sort_key()))
2877 pub fn mk_projection<'tcx>(cx: &ctxt<'tcx>,
2878 trait_ref: Rc<ty::TraitRef<'tcx>>,
2879 item_name: ast::Name)
2881 // take a copy of substs so that we own the vectors inside
2882 let inner = ProjectionTy { trait_ref: trait_ref, item_name: item_name };
2883 mk_t(cx, ty_projection(inner))
2886 pub fn mk_struct<'tcx>(cx: &ctxt<'tcx>, struct_id: ast::DefId,
2887 substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
2888 // take a copy of substs so that we own the vectors inside
2889 mk_t(cx, ty_struct(struct_id, substs))
2892 pub fn mk_closure<'tcx>(cx: &ctxt<'tcx>, closure_id: ast::DefId,
2893 region: &'tcx Region, substs: &'tcx Substs<'tcx>)
2895 mk_t(cx, ty_closure(closure_id, region, substs))
2898 pub fn mk_var<'tcx>(cx: &ctxt<'tcx>, v: TyVid) -> Ty<'tcx> {
2899 mk_infer(cx, TyVar(v))
2902 pub fn mk_int_var<'tcx>(cx: &ctxt<'tcx>, v: IntVid) -> Ty<'tcx> {
2903 mk_infer(cx, IntVar(v))
2906 pub fn mk_float_var<'tcx>(cx: &ctxt<'tcx>, v: FloatVid) -> Ty<'tcx> {
2907 mk_infer(cx, FloatVar(v))
2910 pub fn mk_infer<'tcx>(cx: &ctxt<'tcx>, it: InferTy) -> Ty<'tcx> {
2911 mk_t(cx, ty_infer(it))
2914 pub fn mk_param<'tcx>(cx: &ctxt<'tcx>,
2915 space: subst::ParamSpace,
2917 name: ast::Name) -> Ty<'tcx> {
2918 mk_t(cx, ty_param(ParamTy { space: space, idx: index, name: name }))
2921 pub fn mk_self_type<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2922 mk_param(cx, subst::SelfSpace, 0, special_idents::type_self.name)
2925 pub fn mk_param_from_def<'tcx>(cx: &ctxt<'tcx>, def: &TypeParameterDef) -> Ty<'tcx> {
2926 mk_param(cx, def.space, def.index, def.name)
2929 pub fn mk_open<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_open(ty)) }
2931 impl<'tcx> TyS<'tcx> {
2932 /// Iterator that walks `self` and any types reachable from
2933 /// `self`, in depth-first order. Note that just walks the types
2934 /// that appear in `self`, it does not descend into the fields of
2935 /// structs or variants. For example:
2939 /// Foo<Bar<int>> => { Foo<Bar<int>>, Bar<int>, int }
2940 /// [int] => { [int], int }
2942 pub fn walk(&'tcx self) -> TypeWalker<'tcx> {
2943 TypeWalker::new(self)
2946 /// Iterator that walks types reachable from `self`, in
2947 /// depth-first order. Note that this is a shallow walk. For
2952 /// Foo<Bar<int>> => { Bar<int>, int }
2953 /// [int] => { int }
2955 pub fn walk_children(&'tcx self) -> TypeWalker<'tcx> {
2956 // Walks type reachable from `self` but not `self
2957 let mut walker = self.walk();
2958 let r = walker.next();
2959 assert_eq!(r, Some(self));
2964 pub fn walk_ty<'tcx, F>(ty_root: Ty<'tcx>, mut f: F)
2965 where F: FnMut(Ty<'tcx>),
2967 for ty in ty_root.walk() {
2972 /// Walks `ty` and any types appearing within `ty`, invoking the
2973 /// callback `f` on each type. If the callback returns false, then the
2974 /// children of the current type are ignored.
2976 /// Note: prefer `ty.walk()` where possible.
2977 pub fn maybe_walk_ty<'tcx,F>(ty_root: Ty<'tcx>, mut f: F)
2978 where F : FnMut(Ty<'tcx>) -> bool
2980 let mut walker = ty_root.walk();
2981 while let Some(ty) = walker.next() {
2983 walker.skip_current_subtree();
2988 // Folds types from the bottom up.
2989 pub fn fold_ty<'tcx, F>(cx: &ctxt<'tcx>, t0: Ty<'tcx>,
2992 F: FnMut(Ty<'tcx>) -> Ty<'tcx>,
2994 let mut f = ty_fold::BottomUpFolder {tcx: cx, fldop: fldop};
2999 pub fn new(space: subst::ParamSpace,
3003 ParamTy { space: space, idx: index, name: name }
3006 pub fn for_self() -> ParamTy {
3007 ParamTy::new(subst::SelfSpace, 0, special_idents::type_self.name)
3010 pub fn for_def(def: &TypeParameterDef) -> ParamTy {
3011 ParamTy::new(def.space, def.index, def.name)
3014 pub fn to_ty<'tcx>(self, tcx: &ty::ctxt<'tcx>) -> Ty<'tcx> {
3015 ty::mk_param(tcx, self.space, self.idx, self.name)
3018 pub fn is_self(&self) -> bool {
3019 self.space == subst::SelfSpace && self.idx == 0
3023 impl<'tcx> ItemSubsts<'tcx> {
3024 pub fn empty() -> ItemSubsts<'tcx> {
3025 ItemSubsts { substs: Substs::empty() }
3028 pub fn is_noop(&self) -> bool {
3029 self.substs.is_noop()
3033 impl<'tcx> ParamBounds<'tcx> {
3034 pub fn empty() -> ParamBounds<'tcx> {
3036 builtin_bounds: empty_builtin_bounds(),
3037 trait_bounds: Vec::new(),
3038 region_bounds: Vec::new(),
3039 projection_bounds: Vec::new(),
3046 pub fn type_is_nil(ty: Ty) -> bool {
3048 ty_tup(ref tys) => tys.is_empty(),
3053 pub fn type_is_error(ty: Ty) -> bool {
3054 ty.flags.intersects(HAS_TY_ERR)
3057 pub fn type_needs_subst(ty: Ty) -> bool {
3058 ty.flags.intersects(NEEDS_SUBST)
3061 pub fn trait_ref_contains_error(tref: &ty::TraitRef) -> bool {
3062 tref.substs.types.any(|&ty| type_is_error(ty))
3065 pub fn type_is_ty_var(ty: Ty) -> bool {
3067 ty_infer(TyVar(_)) => true,
3072 pub fn type_is_bool(ty: Ty) -> bool { ty.sty == ty_bool }
3074 pub fn type_is_self(ty: Ty) -> bool {
3076 ty_param(ref p) => p.space == subst::SelfSpace,
3081 fn type_is_slice(ty: Ty) -> bool {
3083 ty_ptr(mt) | ty_rptr(_, mt) => match mt.ty.sty {
3084 ty_vec(_, None) | ty_str => true,
3091 pub fn type_is_vec(ty: Ty) -> bool {
3094 ty_ptr(mt{ty, ..}) | ty_rptr(_, mt{ty, ..}) |
3095 ty_uniq(ty) => match ty.sty {
3096 ty_vec(_, None) => true,
3103 pub fn type_is_structural(ty: Ty) -> bool {
3105 ty_struct(..) | ty_tup(_) | ty_enum(..) |
3106 ty_vec(_, Some(_)) | ty_closure(..) => true,
3107 _ => type_is_slice(ty) | type_is_trait(ty)
3111 pub fn type_is_simd(cx: &ctxt, ty: Ty) -> bool {
3113 ty_struct(did, _) => lookup_simd(cx, did),
3118 pub fn sequence_element_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
3120 ty_vec(ty, _) => ty,
3121 ty_str => mk_mach_uint(cx, ast::TyU8),
3122 ty_open(ty) => sequence_element_type(cx, ty),
3123 _ => cx.sess.bug(&format!("sequence_element_type called on non-sequence value: {}",
3124 ty_to_string(cx, ty))[]),
3128 pub fn simd_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
3130 ty_struct(did, substs) => {
3131 let fields = lookup_struct_fields(cx, did);
3132 lookup_field_type(cx, did, fields[0].id, substs)
3134 _ => panic!("simd_type called on invalid type")
3138 pub fn simd_size(cx: &ctxt, ty: Ty) -> uint {
3140 ty_struct(did, _) => {
3141 let fields = lookup_struct_fields(cx, did);
3144 _ => panic!("simd_size called on invalid type")
3148 pub fn type_is_region_ptr(ty: Ty) -> bool {
3150 ty_rptr(..) => true,
3155 pub fn type_is_unsafe_ptr(ty: Ty) -> bool {
3157 ty_ptr(_) => return true,
3162 pub fn type_is_unique(ty: Ty) -> bool {
3170 A scalar type is one that denotes an atomic datum, with no sub-components.
3171 (A ty_ptr is scalar because it represents a non-managed pointer, so its
3172 contents are abstract to rustc.)
3174 pub fn type_is_scalar(ty: Ty) -> bool {
3176 ty_bool | ty_char | ty_int(_) | ty_float(_) | ty_uint(_) |
3177 ty_infer(IntVar(_)) | ty_infer(FloatVar(_)) |
3178 ty_bare_fn(..) | ty_ptr(_) => true,
3183 /// Returns true if this type is a floating point type and false otherwise.
3184 pub fn type_is_floating_point(ty: Ty) -> bool {
3186 ty_float(_) => true,
3191 /// Type contents is how the type checker reasons about kinds.
3192 /// They track what kinds of things are found within a type. You can
3193 /// think of them as kind of an "anti-kind". They track the kinds of values
3194 /// and thinks that are contained in types. Having a larger contents for
3195 /// a type tends to rule that type *out* from various kinds. For example,
3196 /// a type that contains a reference is not sendable.
3198 /// The reason we compute type contents and not kinds is that it is
3199 /// easier for me (nmatsakis) to think about what is contained within
3200 /// a type than to think about what is *not* contained within a type.
3201 #[derive(Clone, Copy)]
3202 pub struct TypeContents {
3206 macro_rules! def_type_content_sets {
3207 (mod $mname:ident { $($name:ident = $bits:expr),+ }) => {
3208 #[allow(non_snake_case)]
3210 use middle::ty::TypeContents;
3212 #[allow(non_upper_case_globals)]
3213 pub const $name: TypeContents = TypeContents { bits: $bits };
3219 def_type_content_sets! {
3221 None = 0b0000_0000__0000_0000__0000,
3223 // Things that are interior to the value (first nibble):
3224 InteriorUnsized = 0b0000_0000__0000_0000__0001,
3225 InteriorUnsafe = 0b0000_0000__0000_0000__0010,
3226 InteriorParam = 0b0000_0000__0000_0000__0100,
3227 // InteriorAll = 0b00000000__00000000__1111,
3229 // Things that are owned by the value (second and third nibbles):
3230 OwnsOwned = 0b0000_0000__0000_0001__0000,
3231 OwnsDtor = 0b0000_0000__0000_0010__0000,
3232 OwnsManaged /* see [1] below */ = 0b0000_0000__0000_0100__0000,
3233 OwnsAll = 0b0000_0000__1111_1111__0000,
3235 // Things that are reachable by the value in any way (fourth nibble):
3236 ReachesBorrowed = 0b0000_0010__0000_0000__0000,
3237 // ReachesManaged /* see [1] below */ = 0b0000_0100__0000_0000__0000,
3238 ReachesMutable = 0b0000_1000__0000_0000__0000,
3239 ReachesFfiUnsafe = 0b0010_0000__0000_0000__0000,
3240 ReachesAll = 0b0011_1111__0000_0000__0000,
3242 // Things that mean drop glue is necessary
3243 NeedsDrop = 0b0000_0000__0000_0111__0000,
3245 // Things that prevent values from being considered sized
3246 Nonsized = 0b0000_0000__0000_0000__0001,
3248 // Bits to set when a managed value is encountered
3250 // [1] Do not set the bits TC::OwnsManaged or
3251 // TC::ReachesManaged directly, instead reference
3252 // TC::Managed to set them both at once.
3253 Managed = 0b0000_0100__0000_0100__0000,
3256 All = 0b1111_1111__1111_1111__1111
3261 pub fn when(&self, cond: bool) -> TypeContents {
3262 if cond {*self} else {TC::None}
3265 pub fn intersects(&self, tc: TypeContents) -> bool {
3266 (self.bits & tc.bits) != 0
3269 pub fn owns_managed(&self) -> bool {
3270 self.intersects(TC::OwnsManaged)
3273 pub fn owns_owned(&self) -> bool {
3274 self.intersects(TC::OwnsOwned)
3277 pub fn is_sized(&self, _: &ctxt) -> bool {
3278 !self.intersects(TC::Nonsized)
3281 pub fn interior_param(&self) -> bool {
3282 self.intersects(TC::InteriorParam)
3285 pub fn interior_unsafe(&self) -> bool {
3286 self.intersects(TC::InteriorUnsafe)
3289 pub fn interior_unsized(&self) -> bool {
3290 self.intersects(TC::InteriorUnsized)
3293 pub fn needs_drop(&self, _: &ctxt) -> bool {
3294 self.intersects(TC::NeedsDrop)
3297 /// Includes only those bits that still apply when indirected through a `Box` pointer
3298 pub fn owned_pointer(&self) -> TypeContents {
3300 *self & (TC::OwnsAll | TC::ReachesAll))
3303 /// Includes only those bits that still apply when indirected through a reference (`&`)
3304 pub fn reference(&self, bits: TypeContents) -> TypeContents {
3306 *self & TC::ReachesAll)
3309 /// Includes only those bits that still apply when indirected through a managed pointer (`@`)
3310 pub fn managed_pointer(&self) -> TypeContents {
3312 *self & TC::ReachesAll)
3315 /// Includes only those bits that still apply when indirected through an unsafe pointer (`*`)
3316 pub fn unsafe_pointer(&self) -> TypeContents {
3317 *self & TC::ReachesAll
3320 pub fn union<T, F>(v: &[T], mut f: F) -> TypeContents where
3321 F: FnMut(&T) -> TypeContents,
3323 v.iter().fold(TC::None, |tc, ty| tc | f(ty))
3326 pub fn has_dtor(&self) -> bool {
3327 self.intersects(TC::OwnsDtor)
3331 impl ops::BitOr for TypeContents {
3332 type Output = TypeContents;
3334 fn bitor(self, other: TypeContents) -> TypeContents {
3335 TypeContents {bits: self.bits | other.bits}
3339 impl ops::BitAnd for TypeContents {
3340 type Output = TypeContents;
3342 fn bitand(self, other: TypeContents) -> TypeContents {
3343 TypeContents {bits: self.bits & other.bits}
3347 impl ops::Sub for TypeContents {
3348 type Output = TypeContents;
3350 fn sub(self, other: TypeContents) -> TypeContents {
3351 TypeContents {bits: self.bits & !other.bits}
3355 impl fmt::Debug for TypeContents {
3356 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
3357 write!(f, "TypeContents({:b})", self.bits)
3361 pub fn type_interior_is_unsafe<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
3362 type_contents(cx, ty).interior_unsafe()
3365 pub fn type_contents<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> TypeContents {
3366 return memoized(&cx.tc_cache, ty, |ty| {
3367 tc_ty(cx, ty, &mut FnvHashMap())
3370 fn tc_ty<'tcx>(cx: &ctxt<'tcx>,
3372 cache: &mut FnvHashMap<Ty<'tcx>, TypeContents>) -> TypeContents
3374 // Subtle: Note that we are *not* using cx.tc_cache here but rather a
3375 // private cache for this walk. This is needed in the case of cyclic
3378 // struct List { next: Box<Option<List>>, ... }
3380 // When computing the type contents of such a type, we wind up deeply
3381 // recursing as we go. So when we encounter the recursive reference
3382 // to List, we temporarily use TC::None as its contents. Later we'll
3383 // patch up the cache with the correct value, once we've computed it
3384 // (this is basically a co-inductive process, if that helps). So in
3385 // the end we'll compute TC::OwnsOwned, in this case.
3387 // The problem is, as we are doing the computation, we will also
3388 // compute an *intermediate* contents for, e.g., Option<List> of
3389 // TC::None. This is ok during the computation of List itself, but if
3390 // we stored this intermediate value into cx.tc_cache, then later
3391 // requests for the contents of Option<List> would also yield TC::None
3392 // which is incorrect. This value was computed based on the crutch
3393 // value for the type contents of list. The correct value is
3394 // TC::OwnsOwned. This manifested as issue #4821.
3395 match cache.get(&ty) {
3396 Some(tc) => { return *tc; }
3399 match cx.tc_cache.borrow().get(&ty) { // Must check both caches!
3400 Some(tc) => { return *tc; }
3403 cache.insert(ty, TC::None);
3405 let result = match ty.sty {
3406 // uint and int are ffi-unsafe
3407 ty_uint(ast::TyUs(_)) | ty_int(ast::TyIs(_)) => {
3408 TC::ReachesFfiUnsafe
3411 // Scalar and unique types are sendable, and durable
3412 ty_infer(ty::FreshIntTy(_)) |
3413 ty_bool | ty_int(_) | ty_uint(_) | ty_float(_) |
3414 ty_bare_fn(..) | ty::ty_char => {
3419 TC::ReachesFfiUnsafe | match typ.sty {
3420 ty_str => TC::OwnsOwned,
3421 _ => tc_ty(cx, typ, cache).owned_pointer(),
3425 ty_trait(box TyTrait { ref bounds, .. }) => {
3426 object_contents(bounds) | TC::ReachesFfiUnsafe | TC::Nonsized
3430 tc_ty(cx, mt.ty, cache).unsafe_pointer()
3433 ty_rptr(r, ref mt) => {
3434 TC::ReachesFfiUnsafe | match mt.ty.sty {
3435 ty_str => borrowed_contents(*r, ast::MutImmutable),
3436 ty_vec(..) => tc_ty(cx, mt.ty, cache).reference(borrowed_contents(*r,
3438 _ => tc_ty(cx, mt.ty, cache).reference(borrowed_contents(*r, mt.mutbl)),
3442 ty_vec(ty, Some(_)) => {
3443 tc_ty(cx, ty, cache)
3446 ty_vec(ty, None) => {
3447 tc_ty(cx, ty, cache) | TC::Nonsized
3449 ty_str => TC::Nonsized,
3451 ty_struct(did, substs) => {
3452 let flds = struct_fields(cx, did, substs);
3454 TypeContents::union(&flds[],
3455 |f| tc_mt(cx, f.mt, cache));
3457 if !lookup_repr_hints(cx, did).contains(&attr::ReprExtern) {
3458 res = res | TC::ReachesFfiUnsafe;
3461 if ty::has_dtor(cx, did) {
3462 res = res | TC::OwnsDtor;
3464 apply_lang_items(cx, did, res)
3467 ty_closure(did, r, substs) => {
3468 // FIXME(#14449): `borrowed_contents` below assumes `&mut` closure.
3469 let param_env = ty::empty_parameter_environment(cx);
3470 let upvars = closure_upvars(¶m_env, did, substs).unwrap();
3471 TypeContents::union(&upvars,
3472 |f| tc_ty(cx, &f.ty, cache))
3473 | borrowed_contents(*r, MutMutable)
3476 ty_tup(ref tys) => {
3477 TypeContents::union(&tys[],
3478 |ty| tc_ty(cx, *ty, cache))
3481 ty_enum(did, substs) => {
3482 let variants = substd_enum_variants(cx, did, substs);
3484 TypeContents::union(&variants[], |variant| {
3485 TypeContents::union(&variant.args[],
3487 tc_ty(cx, *arg_ty, cache)
3491 if ty::has_dtor(cx, did) {
3492 res = res | TC::OwnsDtor;
3495 if variants.len() != 0 {
3496 let repr_hints = lookup_repr_hints(cx, did);
3497 if repr_hints.len() > 1 {
3498 // this is an error later on, but this type isn't safe
3499 res = res | TC::ReachesFfiUnsafe;
3502 match repr_hints.get(0) {
3503 Some(h) => if !h.is_ffi_safe() {
3504 res = res | TC::ReachesFfiUnsafe;
3508 res = res | TC::ReachesFfiUnsafe;
3510 // We allow ReprAny enums if they are eligible for
3511 // the nullable pointer optimization and the
3512 // contained type is an `extern fn`
3514 if variants.len() == 2 {
3515 let mut data_idx = 0;
3517 if variants[0].args.len() == 0 {
3521 if variants[data_idx].args.len() == 1 {
3522 match variants[data_idx].args[0].sty {
3523 ty_bare_fn(..) => { res = res - TC::ReachesFfiUnsafe; }
3533 apply_lang_items(cx, did, res)
3542 let result = tc_ty(cx, ty, cache);
3543 assert!(!result.is_sized(cx));
3544 result.unsafe_pointer() | TC::Nonsized
3549 cx.sess.bug("asked to compute contents of error type");
3553 cache.insert(ty, result);
3557 fn tc_mt<'tcx>(cx: &ctxt<'tcx>,
3559 cache: &mut FnvHashMap<Ty<'tcx>, TypeContents>) -> TypeContents
3561 let mc = TC::ReachesMutable.when(mt.mutbl == MutMutable);
3562 mc | tc_ty(cx, mt.ty, cache)
3565 fn apply_lang_items(cx: &ctxt, did: ast::DefId, tc: TypeContents)
3567 if Some(did) == cx.lang_items.managed_bound() {
3569 } else if Some(did) == cx.lang_items.unsafe_cell_type() {
3570 tc | TC::InteriorUnsafe
3576 /// Type contents due to containing a reference with the region `region` and borrow kind `bk`
3577 fn borrowed_contents(region: ty::Region,
3578 mutbl: ast::Mutability)
3580 let b = match mutbl {
3581 ast::MutMutable => TC::ReachesMutable,
3582 ast::MutImmutable => TC::None,
3584 b | (TC::ReachesBorrowed).when(region != ty::ReStatic)
3587 fn object_contents(bounds: &ExistentialBounds) -> TypeContents {
3588 // These are the type contents of the (opaque) interior. We
3589 // make no assumptions (other than that it cannot have an
3590 // in-scope type parameter within, which makes no sense).
3591 let mut tc = TC::All - TC::InteriorParam;
3592 for bound in &bounds.builtin_bounds {
3593 tc = tc - match bound {
3594 BoundSync | BoundSend | BoundCopy => TC::None,
3595 BoundSized => TC::Nonsized,
3602 fn type_impls_bound<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3603 cache: &RefCell<HashMap<Ty<'tcx>,bool>>,
3605 bound: ty::BuiltinBound,
3609 assert!(!ty::type_needs_infer(ty));
3611 if !type_has_params(ty) && !type_has_self(ty) {
3612 match cache.borrow().get(&ty) {
3615 debug!("type_impls_bound({}, {:?}) = {:?} (cached)",
3616 ty.repr(param_env.tcx),
3624 let infcx = infer::new_infer_ctxt(param_env.tcx);
3626 let is_impld = traits::type_known_to_meet_builtin_bound(&infcx, param_env, ty, bound, span);
3628 debug!("type_impls_bound({}, {:?}) = {:?}",
3629 ty.repr(param_env.tcx),
3633 if !type_has_params(ty) && !type_has_self(ty) {
3634 let old_value = cache.borrow_mut().insert(ty, is_impld);
3635 assert!(old_value.is_none());
3641 pub fn type_moves_by_default<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3646 let tcx = param_env.tcx;
3647 !type_impls_bound(param_env, &tcx.type_impls_copy_cache, ty, ty::BoundCopy, span)
3650 pub fn type_is_sized<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3655 let tcx = param_env.tcx;
3656 type_impls_bound(param_env, &tcx.type_impls_sized_cache, ty, ty::BoundSized, span)
3659 pub fn is_ffi_safe<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
3660 !type_contents(cx, ty).intersects(TC::ReachesFfiUnsafe)
3663 // True if instantiating an instance of `r_ty` requires an instance of `r_ty`.
3664 pub fn is_instantiable<'tcx>(cx: &ctxt<'tcx>, r_ty: Ty<'tcx>) -> bool {
3665 fn type_requires<'tcx>(cx: &ctxt<'tcx>, seen: &mut Vec<DefId>,
3666 r_ty: Ty<'tcx>, ty: Ty<'tcx>) -> bool {
3667 debug!("type_requires({:?}, {:?})?",
3668 ::util::ppaux::ty_to_string(cx, r_ty),
3669 ::util::ppaux::ty_to_string(cx, ty));
3671 let r = r_ty == ty || subtypes_require(cx, seen, r_ty, ty);
3673 debug!("type_requires({:?}, {:?})? {:?}",
3674 ::util::ppaux::ty_to_string(cx, r_ty),
3675 ::util::ppaux::ty_to_string(cx, ty),
3680 fn subtypes_require<'tcx>(cx: &ctxt<'tcx>, seen: &mut Vec<DefId>,
3681 r_ty: Ty<'tcx>, ty: Ty<'tcx>) -> bool {
3682 debug!("subtypes_require({:?}, {:?})?",
3683 ::util::ppaux::ty_to_string(cx, r_ty),
3684 ::util::ppaux::ty_to_string(cx, ty));
3686 let r = match ty.sty {
3687 // fixed length vectors need special treatment compared to
3688 // normal vectors, since they don't necessarily have the
3689 // possibility to have length zero.
3690 ty_vec(_, Some(0)) => false, // don't need no contents
3691 ty_vec(ty, Some(_)) => type_requires(cx, seen, r_ty, ty),
3702 ty_vec(_, None) => {
3705 ty_uniq(typ) | ty_open(typ) => {
3706 type_requires(cx, seen, r_ty, typ)
3708 ty_rptr(_, ref mt) => {
3709 type_requires(cx, seen, r_ty, mt.ty)
3713 false // unsafe ptrs can always be NULL
3720 ty_struct(ref did, _) if seen.contains(did) => {
3724 ty_struct(did, substs) => {
3726 let fields = struct_fields(cx, did, substs);
3727 let r = fields.iter().any(|f| type_requires(cx, seen, r_ty, f.mt.ty));
3728 seen.pop().unwrap();
3735 // this check is run on type definitions, so we don't expect to see
3736 // inference by-products or closure types
3737 cx.sess.bug(&format!("requires check invoked on inapplicable type: {:?}", ty))
3741 ts.iter().any(|ty| type_requires(cx, seen, r_ty, *ty))
3744 ty_enum(ref did, _) if seen.contains(did) => {
3748 ty_enum(did, substs) => {
3750 let vs = enum_variants(cx, did);
3751 let r = !vs.is_empty() && vs.iter().all(|variant| {
3752 variant.args.iter().any(|aty| {
3753 let sty = aty.subst(cx, substs);
3754 type_requires(cx, seen, r_ty, sty)
3757 seen.pop().unwrap();
3762 debug!("subtypes_require({:?}, {:?})? {:?}",
3763 ::util::ppaux::ty_to_string(cx, r_ty),
3764 ::util::ppaux::ty_to_string(cx, ty),
3770 let mut seen = Vec::new();
3771 !subtypes_require(cx, &mut seen, r_ty, r_ty)
3774 /// Describes whether a type is representable. For types that are not
3775 /// representable, 'SelfRecursive' and 'ContainsRecursive' are used to
3776 /// distinguish between types that are recursive with themselves and types that
3777 /// contain a different recursive type. These cases can therefore be treated
3778 /// differently when reporting errors.
3780 /// The ordering of the cases is significant. They are sorted so that cmp::max
3781 /// will keep the "more erroneous" of two values.
3782 #[derive(Copy, PartialOrd, Ord, Eq, PartialEq, Debug)]
3783 pub enum Representability {
3789 /// Check whether a type is representable. This means it cannot contain unboxed
3790 /// structural recursion. This check is needed for structs and enums.
3791 pub fn is_type_representable<'tcx>(cx: &ctxt<'tcx>, sp: Span, ty: Ty<'tcx>)
3792 -> Representability {
3794 // Iterate until something non-representable is found
3795 fn find_nonrepresentable<'tcx, It: Iterator<Item=Ty<'tcx>>>(cx: &ctxt<'tcx>, sp: Span,
3796 seen: &mut Vec<Ty<'tcx>>,
3798 -> Representability {
3799 iter.fold(Representable,
3800 |r, ty| cmp::max(r, is_type_structurally_recursive(cx, sp, seen, ty)))
3803 fn are_inner_types_recursive<'tcx>(cx: &ctxt<'tcx>, sp: Span,
3804 seen: &mut Vec<Ty<'tcx>>, ty: Ty<'tcx>)
3805 -> Representability {
3808 find_nonrepresentable(cx, sp, seen, ts.iter().map(|ty| *ty))
3810 // Fixed-length vectors.
3811 // FIXME(#11924) Behavior undecided for zero-length vectors.
3812 ty_vec(ty, Some(_)) => {
3813 is_type_structurally_recursive(cx, sp, seen, ty)
3815 ty_struct(did, substs) => {
3816 let fields = struct_fields(cx, did, substs);
3817 find_nonrepresentable(cx, sp, seen, fields.iter().map(|f| f.mt.ty))
3819 ty_enum(did, substs) => {
3820 let vs = enum_variants(cx, did);
3821 let iter = vs.iter()
3822 .flat_map(|variant| { variant.args.iter() })
3823 .map(|aty| { aty.subst_spanned(cx, substs, Some(sp)) });
3825 find_nonrepresentable(cx, sp, seen, iter)
3828 // this check is run on type definitions, so we don't expect
3829 // to see closure types
3830 cx.sess.bug(&format!("requires check invoked on inapplicable type: {:?}", ty))
3836 fn same_struct_or_enum_def_id(ty: Ty, did: DefId) -> bool {
3838 ty_struct(ty_did, _) | ty_enum(ty_did, _) => {
3845 fn same_type<'tcx>(a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
3846 match (&a.sty, &b.sty) {
3847 (&ty_struct(did_a, ref substs_a), &ty_struct(did_b, ref substs_b)) |
3848 (&ty_enum(did_a, ref substs_a), &ty_enum(did_b, ref substs_b)) => {
3853 let types_a = substs_a.types.get_slice(subst::TypeSpace);
3854 let types_b = substs_b.types.get_slice(subst::TypeSpace);
3856 let pairs = types_a.iter().zip(types_b.iter());
3858 pairs.all(|(&a, &b)| same_type(a, b))
3866 // Does the type `ty` directly (without indirection through a pointer)
3867 // contain any types on stack `seen`?
3868 fn is_type_structurally_recursive<'tcx>(cx: &ctxt<'tcx>, sp: Span,
3869 seen: &mut Vec<Ty<'tcx>>,
3870 ty: Ty<'tcx>) -> Representability {
3871 debug!("is_type_structurally_recursive: {:?}",
3872 ::util::ppaux::ty_to_string(cx, ty));
3875 ty_struct(did, _) | ty_enum(did, _) => {
3877 // Iterate through stack of previously seen types.
3878 let mut iter = seen.iter();
3880 // The first item in `seen` is the type we are actually curious about.
3881 // We want to return SelfRecursive if this type contains itself.
3882 // It is important that we DON'T take generic parameters into account
3883 // for this check, so that Bar<T> in this example counts as SelfRecursive:
3886 // struct Bar<T> { x: Bar<Foo> }
3889 Some(&seen_type) => {
3890 if same_struct_or_enum_def_id(seen_type, did) {
3891 debug!("SelfRecursive: {:?} contains {:?}",
3892 ::util::ppaux::ty_to_string(cx, seen_type),
3893 ::util::ppaux::ty_to_string(cx, ty));
3894 return SelfRecursive;
3900 // We also need to know whether the first item contains other types that
3901 // are structurally recursive. If we don't catch this case, we will recurse
3902 // infinitely for some inputs.
3904 // It is important that we DO take generic parameters into account here,
3905 // so that code like this is considered SelfRecursive, not ContainsRecursive:
3907 // struct Foo { Option<Option<Foo>> }
3909 for &seen_type in iter {
3910 if same_type(ty, seen_type) {
3911 debug!("ContainsRecursive: {:?} contains {:?}",
3912 ::util::ppaux::ty_to_string(cx, seen_type),
3913 ::util::ppaux::ty_to_string(cx, ty));
3914 return ContainsRecursive;
3919 // For structs and enums, track all previously seen types by pushing them
3920 // onto the 'seen' stack.
3922 let out = are_inner_types_recursive(cx, sp, seen, ty);
3927 // No need to push in other cases.
3928 are_inner_types_recursive(cx, sp, seen, ty)
3933 debug!("is_type_representable: {:?}",
3934 ::util::ppaux::ty_to_string(cx, ty));
3936 // To avoid a stack overflow when checking an enum variant or struct that
3937 // contains a different, structurally recursive type, maintain a stack
3938 // of seen types and check recursion for each of them (issues #3008, #3779).
3939 let mut seen: Vec<Ty> = Vec::new();
3940 let r = is_type_structurally_recursive(cx, sp, &mut seen, ty);
3941 debug!("is_type_representable: {:?} is {:?}",
3942 ::util::ppaux::ty_to_string(cx, ty), r);
3946 pub fn type_is_trait(ty: Ty) -> bool {
3947 type_trait_info(ty).is_some()
3950 pub fn type_trait_info<'tcx>(ty: Ty<'tcx>) -> Option<&'tcx TyTrait<'tcx>> {
3952 ty_uniq(ty) | ty_rptr(_, mt { ty, ..}) | ty_ptr(mt { ty, ..}) => match ty.sty {
3953 ty_trait(ref t) => Some(&**t),
3956 ty_trait(ref t) => Some(&**t),
3961 pub fn type_is_integral(ty: Ty) -> bool {
3963 ty_infer(IntVar(_)) | ty_int(_) | ty_uint(_) => true,
3968 pub fn type_is_fresh(ty: Ty) -> bool {
3970 ty_infer(FreshTy(_)) => true,
3971 ty_infer(FreshIntTy(_)) => true,
3976 pub fn type_is_uint(ty: Ty) -> bool {
3978 ty_infer(IntVar(_)) | ty_uint(ast::TyUs(_)) => true,
3983 pub fn type_is_char(ty: Ty) -> bool {
3990 pub fn type_is_bare_fn(ty: Ty) -> bool {
3992 ty_bare_fn(..) => true,
3997 pub fn type_is_bare_fn_item(ty: Ty) -> bool {
3999 ty_bare_fn(Some(_), _) => true,
4004 pub fn type_is_fp(ty: Ty) -> bool {
4006 ty_infer(FloatVar(_)) | ty_float(_) => true,
4011 pub fn type_is_numeric(ty: Ty) -> bool {
4012 return type_is_integral(ty) || type_is_fp(ty);
4015 pub fn type_is_signed(ty: Ty) -> bool {
4022 pub fn type_is_machine(ty: Ty) -> bool {
4024 ty_int(ast::TyIs(_)) | ty_uint(ast::TyUs(_)) => false,
4025 ty_int(..) | ty_uint(..) | ty_float(..) => true,
4030 // Whether a type is enum like, that is an enum type with only nullary
4032 pub fn type_is_c_like_enum(cx: &ctxt, ty: Ty) -> bool {
4034 ty_enum(did, _) => {
4035 let variants = enum_variants(cx, did);
4036 if variants.len() == 0 {
4039 variants.iter().all(|v| v.args.len() == 0)
4046 // Returns the type and mutability of *ty.
4048 // The parameter `explicit` indicates if this is an *explicit* dereference.
4049 // Some types---notably unsafe ptrs---can only be dereferenced explicitly.
4050 pub fn deref<'tcx>(ty: Ty<'tcx>, explicit: bool) -> Option<mt<'tcx>> {
4055 mutbl: ast::MutImmutable,
4058 ty_rptr(_, mt) => Some(mt),
4059 ty_ptr(mt) if explicit => Some(mt),
4064 pub fn close_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
4066 ty_open(ty) => mk_rptr(cx, cx.mk_region(ReStatic), mt {ty: ty, mutbl:ast::MutImmutable}),
4067 _ => cx.sess.bug(&format!("Trying to close a non-open type {}",
4068 ty_to_string(cx, ty))[])
4072 pub fn type_content<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
4075 ty_rptr(_, mt) |ty_ptr(mt) => mt.ty,
4080 // Extract the unsized type in an open type (or just return ty if it is not open).
4081 pub fn unopen_type<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
4088 // Returns the type of ty[i]
4089 pub fn index<'tcx>(ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
4091 ty_vec(ty, _) => Some(ty),
4096 // Returns the type of elements contained within an 'array-like' type.
4097 // This is exactly the same as the above, except it supports strings,
4098 // which can't actually be indexed.
4099 pub fn array_element_ty<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
4101 ty_vec(ty, _) => Some(ty),
4102 ty_str => Some(tcx.types.u8),
4107 /// Returns the type of element at index `i` in tuple or tuple-like type `t`.
4108 /// For an enum `t`, `variant` is None only if `t` is a univariant enum.
4109 pub fn positional_element_ty<'tcx>(cx: &ctxt<'tcx>,
4112 variant: Option<ast::DefId>) -> Option<Ty<'tcx>> {
4114 match (&ty.sty, variant) {
4115 (&ty_tup(ref v), None) => v.get(i).map(|&t| t),
4118 (&ty_struct(def_id, substs), None) => lookup_struct_fields(cx, def_id)
4120 .map(|&t|lookup_item_type(cx, t.id).ty.subst(cx, substs)),
4122 (&ty_enum(def_id, substs), Some(variant_def_id)) => {
4123 let variant_info = enum_variant_with_id(cx, def_id, variant_def_id);
4124 variant_info.args.get(i).map(|t|t.subst(cx, substs))
4127 (&ty_enum(def_id, substs), None) => {
4128 assert!(enum_is_univariant(cx, def_id));
4129 let enum_variants = enum_variants(cx, def_id);
4130 let variant_info = &(*enum_variants)[0];
4131 variant_info.args.get(i).map(|t|t.subst(cx, substs))
4138 /// Returns the type of element at field `n` in struct or struct-like type `t`.
4139 /// For an enum `t`, `variant` must be some def id.
4140 pub fn named_element_ty<'tcx>(cx: &ctxt<'tcx>,
4143 variant: Option<ast::DefId>) -> Option<Ty<'tcx>> {
4145 match (&ty.sty, variant) {
4146 (&ty_struct(def_id, substs), None) => {
4147 let r = lookup_struct_fields(cx, def_id);
4148 r.iter().find(|f| f.name == n)
4149 .map(|&f| lookup_field_type(cx, def_id, f.id, substs))
4151 (&ty_enum(def_id, substs), Some(variant_def_id)) => {
4152 let variant_info = enum_variant_with_id(cx, def_id, variant_def_id);
4153 variant_info.arg_names.as_ref()
4154 .expect("must have struct enum variant if accessing a named fields")
4155 .iter().zip(variant_info.args.iter())
4156 .find(|&(ident, _)| ident.name == n)
4157 .map(|(_ident, arg_t)| arg_t.subst(cx, substs))
4163 pub fn node_id_to_trait_ref<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId)
4164 -> Rc<ty::TraitRef<'tcx>> {
4165 match cx.trait_refs.borrow().get(&id) {
4166 Some(ty) => ty.clone(),
4167 None => cx.sess.bug(
4168 &format!("node_id_to_trait_ref: no trait ref for node `{}`",
4169 cx.map.node_to_string(id))[])
4173 pub fn node_id_to_type<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Ty<'tcx> {
4174 match node_id_to_type_opt(cx, id) {
4176 None => cx.sess.bug(
4177 &format!("node_id_to_type: no type for node `{}`",
4178 cx.map.node_to_string(id))[])
4182 pub fn node_id_to_type_opt<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Option<Ty<'tcx>> {
4183 match cx.node_types.borrow().get(&id) {
4184 Some(&ty) => Some(ty),
4189 pub fn node_id_item_substs<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> ItemSubsts<'tcx> {
4190 match cx.item_substs.borrow().get(&id) {
4191 None => ItemSubsts::empty(),
4192 Some(ts) => ts.clone(),
4196 pub fn fn_is_variadic(fty: Ty) -> bool {
4198 ty_bare_fn(_, ref f) => f.sig.0.variadic,
4200 panic!("fn_is_variadic() called on non-fn type: {:?}", s)
4205 pub fn ty_fn_sig<'tcx>(fty: Ty<'tcx>) -> &'tcx PolyFnSig<'tcx> {
4207 ty_bare_fn(_, ref f) => &f.sig,
4209 panic!("ty_fn_sig() called on non-fn type: {:?}", s)
4214 /// Returns the ABI of the given function.
4215 pub fn ty_fn_abi(fty: Ty) -> abi::Abi {
4217 ty_bare_fn(_, ref f) => f.abi,
4218 _ => panic!("ty_fn_abi() called on non-fn type"),
4222 // Type accessors for substructures of types
4223 pub fn ty_fn_args<'tcx>(fty: Ty<'tcx>) -> ty::Binder<Vec<Ty<'tcx>>> {
4224 ty_fn_sig(fty).inputs()
4227 pub fn ty_fn_ret<'tcx>(fty: Ty<'tcx>) -> Binder<FnOutput<'tcx>> {
4229 ty_bare_fn(_, ref f) => f.sig.output(),
4231 panic!("ty_fn_ret() called on non-fn type: {:?}", s)
4236 pub fn is_fn_ty(fty: Ty) -> bool {
4238 ty_bare_fn(..) => true,
4243 pub fn ty_region(tcx: &ctxt,
4247 ty_rptr(r, _) => *r,
4251 &format!("ty_region() invoked on an inappropriate ty: {:?}",
4257 pub fn free_region_from_def(outlives_extent: region::DestructionScopeData,
4258 def: &RegionParameterDef)
4262 ty::ReFree(ty::FreeRegion { scope: outlives_extent,
4263 bound_region: ty::BrNamed(def.def_id,
4265 debug!("free_region_from_def returns {:?}", ret);
4269 // Returns the type of a pattern as a monotype. Like @expr_ty, this function
4270 // doesn't provide type parameter substitutions.
4271 pub fn pat_ty<'tcx>(cx: &ctxt<'tcx>, pat: &ast::Pat) -> Ty<'tcx> {
4272 return node_id_to_type(cx, pat.id);
4276 // Returns the type of an expression as a monotype.
4278 // NB (1): This is the PRE-ADJUSTMENT TYPE for the expression. That is, in
4279 // some cases, we insert `AutoAdjustment` annotations such as auto-deref or
4280 // auto-ref. The type returned by this function does not consider such
4281 // adjustments. See `expr_ty_adjusted()` instead.
4283 // NB (2): This type doesn't provide type parameter substitutions; e.g. if you
4284 // ask for the type of "id" in "id(3)", it will return "fn(&int) -> int"
4285 // instead of "fn(ty) -> T with T = int".
4286 pub fn expr_ty<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Ty<'tcx> {
4287 return node_id_to_type(cx, expr.id);
4290 pub fn expr_ty_opt<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Option<Ty<'tcx>> {
4291 return node_id_to_type_opt(cx, expr.id);
4294 /// Returns the type of `expr`, considering any `AutoAdjustment`
4295 /// entry recorded for that expression.
4297 /// It would almost certainly be better to store the adjusted ty in with
4298 /// the `AutoAdjustment`, but I opted not to do this because it would
4299 /// require serializing and deserializing the type and, although that's not
4300 /// hard to do, I just hate that code so much I didn't want to touch it
4301 /// unless it was to fix it properly, which seemed a distraction from the
4302 /// task at hand! -nmatsakis
4303 pub fn expr_ty_adjusted<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Ty<'tcx> {
4304 adjust_ty(cx, expr.span, expr.id, expr_ty(cx, expr),
4305 cx.adjustments.borrow().get(&expr.id),
4306 |method_call| cx.method_map.borrow().get(&method_call).map(|method| method.ty))
4309 pub fn expr_span(cx: &ctxt, id: NodeId) -> Span {
4310 match cx.map.find(id) {
4311 Some(ast_map::NodeExpr(e)) => {
4315 cx.sess.bug(&format!("Node id {} is not an expr: {:?}",
4320 cx.sess.bug(&format!("Node id {} is not present \
4321 in the node map", id)[]);
4326 pub fn local_var_name_str(cx: &ctxt, id: NodeId) -> InternedString {
4327 match cx.map.find(id) {
4328 Some(ast_map::NodeLocal(pat)) => {
4330 ast::PatIdent(_, ref path1, _) => {
4331 token::get_ident(path1.node)
4335 &format!("Variable id {} maps to {:?}, not local",
4342 cx.sess.bug(&format!("Variable id {} maps to {:?}, not local",
4349 /// See `expr_ty_adjusted`
4350 pub fn adjust_ty<'tcx, F>(cx: &ctxt<'tcx>,
4352 expr_id: ast::NodeId,
4353 unadjusted_ty: Ty<'tcx>,
4354 adjustment: Option<&AutoAdjustment<'tcx>>,
4357 F: FnMut(MethodCall) -> Option<Ty<'tcx>>,
4359 if let ty_err = unadjusted_ty.sty {
4360 return unadjusted_ty;
4363 return match adjustment {
4364 Some(adjustment) => {
4366 AdjustReifyFnPointer(_) => {
4367 match unadjusted_ty.sty {
4368 ty::ty_bare_fn(Some(_), b) => {
4369 ty::mk_bare_fn(cx, None, b)
4373 &format!("AdjustReifyFnPointer adjustment on non-fn-item: \
4380 AdjustDerefRef(ref adj) => {
4381 let mut adjusted_ty = unadjusted_ty;
4383 if !ty::type_is_error(adjusted_ty) {
4384 for i in 0..adj.autoderefs {
4385 let method_call = MethodCall::autoderef(expr_id, i);
4386 match method_type(method_call) {
4387 Some(method_ty) => {
4388 // overloaded deref operators have all late-bound
4389 // regions fully instantiated and coverge
4391 ty::no_late_bound_regions(cx,
4392 &ty_fn_ret(method_ty)).unwrap();
4393 adjusted_ty = fn_ret.unwrap();
4397 match deref(adjusted_ty, true) {
4398 Some(mt) => { adjusted_ty = mt.ty; }
4402 &format!("the {}th autoderef failed: \
4405 ty_to_string(cx, adjusted_ty))
4412 adjust_ty_for_autoref(cx, span, adjusted_ty, adj.autoref.as_ref())
4416 None => unadjusted_ty
4420 pub fn adjust_ty_for_autoref<'tcx>(cx: &ctxt<'tcx>,
4423 autoref: Option<&AutoRef<'tcx>>)
4429 Some(&AutoPtr(r, m, ref a)) => {
4430 let adjusted_ty = match a {
4431 &Some(box ref a) => adjust_ty_for_autoref(cx, span, ty, Some(a)),
4434 mk_rptr(cx, cx.mk_region(r), mt {
4440 Some(&AutoUnsafe(m, ref a)) => {
4441 let adjusted_ty = match a {
4442 &Some(box ref a) => adjust_ty_for_autoref(cx, span, ty, Some(a)),
4445 mk_ptr(cx, mt {ty: adjusted_ty, mutbl: m})
4448 Some(&AutoUnsize(ref k)) => unsize_ty(cx, ty, k, span),
4450 Some(&AutoUnsizeUniq(ref k)) => ty::mk_uniq(cx, unsize_ty(cx, ty, k, span)),
4454 // Take a sized type and a sizing adjustment and produce an unsized version of
4456 pub fn unsize_ty<'tcx>(cx: &ctxt<'tcx>,
4458 kind: &UnsizeKind<'tcx>,
4462 &UnsizeLength(len) => match ty.sty {
4463 ty_vec(ty, Some(n)) => {
4465 mk_vec(cx, ty, None)
4467 _ => cx.sess.span_bug(span,
4468 &format!("UnsizeLength with bad sty: {:?}",
4469 ty_to_string(cx, ty))[])
4471 &UnsizeStruct(box ref k, tp_index) => match ty.sty {
4472 ty_struct(did, substs) => {
4473 let ty_substs = substs.types.get_slice(subst::TypeSpace);
4474 let new_ty = unsize_ty(cx, ty_substs[tp_index], k, span);
4475 let mut unsized_substs = substs.clone();
4476 unsized_substs.types.get_mut_slice(subst::TypeSpace)[tp_index] = new_ty;
4477 mk_struct(cx, did, cx.mk_substs(unsized_substs))
4479 _ => cx.sess.span_bug(span,
4480 &format!("UnsizeStruct with bad sty: {:?}",
4481 ty_to_string(cx, ty))[])
4483 &UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
4484 mk_trait(cx, principal.clone(), bounds.clone())
4489 pub fn resolve_expr(tcx: &ctxt, expr: &ast::Expr) -> def::Def {
4490 match tcx.def_map.borrow().get(&expr.id) {
4493 tcx.sess.span_bug(expr.span, &format!(
4494 "no def-map entry for expr {}", expr.id)[]);
4499 pub fn expr_is_lval(tcx: &ctxt, e: &ast::Expr) -> bool {
4500 match expr_kind(tcx, e) {
4502 RvalueDpsExpr | RvalueDatumExpr | RvalueStmtExpr => false
4506 /// We categorize expressions into three kinds. The distinction between
4507 /// lvalue/rvalue is fundamental to the language. The distinction between the
4508 /// two kinds of rvalues is an artifact of trans which reflects how we will
4509 /// generate code for that kind of expression. See trans/expr.rs for more
4519 pub fn expr_kind(tcx: &ctxt, expr: &ast::Expr) -> ExprKind {
4520 if tcx.method_map.borrow().contains_key(&MethodCall::expr(expr.id)) {
4521 // Overloaded operations are generally calls, and hence they are
4522 // generated via DPS, but there are a few exceptions:
4523 return match expr.node {
4524 // `a += b` has a unit result.
4525 ast::ExprAssignOp(..) => RvalueStmtExpr,
4527 // the deref method invoked for `*a` always yields an `&T`
4528 ast::ExprUnary(ast::UnDeref, _) => LvalueExpr,
4530 // the index method invoked for `a[i]` always yields an `&T`
4531 ast::ExprIndex(..) => LvalueExpr,
4533 // in the general case, result could be any type, use DPS
4539 ast::ExprPath(_) | ast::ExprQPath(_) => {
4540 match resolve_expr(tcx, expr) {
4541 def::DefVariant(tid, vid, _) => {
4542 let variant_info = enum_variant_with_id(tcx, tid, vid);
4543 if variant_info.args.len() > 0 {
4552 def::DefStruct(_) => {
4553 match tcx.node_types.borrow().get(&expr.id) {
4554 Some(ty) => match ty.sty {
4555 ty_bare_fn(..) => RvalueDatumExpr,
4558 // See ExprCast below for why types might be missing.
4559 None => RvalueDatumExpr
4563 // Special case: A unit like struct's constructor must be called without () at the
4564 // end (like `UnitStruct`) which means this is an ExprPath to a DefFn. But in case
4565 // of unit structs this is should not be interpreted as function pointer but as
4566 // call to the constructor.
4567 def::DefFn(_, true) => RvalueDpsExpr,
4569 // Fn pointers are just scalar values.
4570 def::DefFn(..) | def::DefStaticMethod(..) | def::DefMethod(..) => RvalueDatumExpr,
4572 // Note: there is actually a good case to be made that
4573 // DefArg's, particularly those of immediate type, ought to
4574 // considered rvalues.
4575 def::DefStatic(..) |
4577 def::DefLocal(..) => LvalueExpr,
4579 def::DefConst(..) => RvalueDatumExpr,
4584 &format!("uncategorized def for expr {}: {:?}",
4591 ast::ExprUnary(ast::UnDeref, _) |
4592 ast::ExprField(..) |
4593 ast::ExprTupField(..) |
4594 ast::ExprIndex(..) => {
4599 ast::ExprMethodCall(..) |
4600 ast::ExprStruct(..) |
4601 ast::ExprRange(..) |
4604 ast::ExprMatch(..) |
4605 ast::ExprClosure(..) |
4606 ast::ExprBlock(..) |
4607 ast::ExprRepeat(..) |
4608 ast::ExprVec(..) => {
4612 ast::ExprIfLet(..) => {
4613 tcx.sess.span_bug(expr.span, "non-desugared ExprIfLet");
4615 ast::ExprWhileLet(..) => {
4616 tcx.sess.span_bug(expr.span, "non-desugared ExprWhileLet");
4619 ast::ExprForLoop(..) => {
4620 tcx.sess.span_bug(expr.span, "non-desugared ExprForLoop");
4623 ast::ExprLit(ref lit) if lit_is_str(&**lit) => {
4627 ast::ExprCast(..) => {
4628 match tcx.node_types.borrow().get(&expr.id) {
4630 if type_is_trait(ty) {
4637 // Technically, it should not happen that the expr is not
4638 // present within the table. However, it DOES happen
4639 // during type check, because the final types from the
4640 // expressions are not yet recorded in the tcx. At that
4641 // time, though, we are only interested in knowing lvalue
4642 // vs rvalue. It would be better to base this decision on
4643 // the AST type in cast node---but (at the time of this
4644 // writing) it's not easy to distinguish casts to traits
4645 // from other casts based on the AST. This should be
4646 // easier in the future, when casts to traits
4647 // would like @Foo, Box<Foo>, or &Foo.
4653 ast::ExprBreak(..) |
4654 ast::ExprAgain(..) |
4656 ast::ExprWhile(..) |
4658 ast::ExprAssign(..) |
4659 ast::ExprInlineAsm(..) |
4660 ast::ExprAssignOp(..) => {
4664 ast::ExprLit(_) | // Note: LitStr is carved out above
4665 ast::ExprUnary(..) |
4666 ast::ExprBox(None, _) |
4667 ast::ExprAddrOf(..) |
4668 ast::ExprBinary(..) => {
4672 ast::ExprBox(Some(ref place), _) => {
4673 // Special case `Box<T>` for now:
4674 let definition = match tcx.def_map.borrow().get(&place.id) {
4676 None => panic!("no def for place"),
4678 let def_id = definition.def_id();
4679 if tcx.lang_items.exchange_heap() == Some(def_id) {
4686 ast::ExprParen(ref e) => expr_kind(tcx, &**e),
4688 ast::ExprMac(..) => {
4691 "macro expression remains after expansion");
4696 pub fn stmt_node_id(s: &ast::Stmt) -> ast::NodeId {
4698 ast::StmtDecl(_, id) | StmtExpr(_, id) | StmtSemi(_, id) => {
4701 ast::StmtMac(..) => panic!("unexpanded macro in trans")
4705 pub fn field_idx_strict(tcx: &ctxt, name: ast::Name, fields: &[field])
4708 for f in fields { if f.name == name { return i; } i += 1; }
4709 tcx.sess.bug(&format!(
4710 "no field named `{}` found in the list of fields `{:?}`",
4711 token::get_name(name),
4713 .map(|f| token::get_name(f.name).to_string())
4714 .collect::<Vec<String>>())[]);
4717 pub fn impl_or_trait_item_idx(id: ast::Name, trait_items: &[ImplOrTraitItem])
4719 trait_items.iter().position(|m| m.name() == id)
4722 pub fn ty_sort_string<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> String {
4724 ty_bool | ty_char | ty_int(_) |
4725 ty_uint(_) | ty_float(_) | ty_str => {
4726 ::util::ppaux::ty_to_string(cx, ty)
4728 ty_tup(ref tys) if tys.is_empty() => ::util::ppaux::ty_to_string(cx, ty),
4730 ty_enum(id, _) => format!("enum `{}`", item_path_str(cx, id)),
4731 ty_uniq(_) => "box".to_string(),
4732 ty_vec(_, Some(n)) => format!("array of {} elements", n),
4733 ty_vec(_, None) => "slice".to_string(),
4734 ty_ptr(_) => "*-ptr".to_string(),
4735 ty_rptr(_, _) => "&-ptr".to_string(),
4736 ty_bare_fn(Some(_), _) => format!("fn item"),
4737 ty_bare_fn(None, _) => "fn pointer".to_string(),
4738 ty_trait(ref inner) => {
4739 format!("trait {}", item_path_str(cx, inner.principal_def_id()))
4741 ty_struct(id, _) => {
4742 format!("struct `{}`", item_path_str(cx, id))
4744 ty_closure(..) => "closure".to_string(),
4745 ty_tup(_) => "tuple".to_string(),
4746 ty_infer(TyVar(_)) => "inferred type".to_string(),
4747 ty_infer(IntVar(_)) => "integral variable".to_string(),
4748 ty_infer(FloatVar(_)) => "floating-point variable".to_string(),
4749 ty_infer(FreshTy(_)) => "skolemized type".to_string(),
4750 ty_infer(FreshIntTy(_)) => "skolemized integral type".to_string(),
4751 ty_projection(_) => "associated type".to_string(),
4752 ty_param(ref p) => {
4753 if p.space == subst::SelfSpace {
4756 "type parameter".to_string()
4759 ty_err => "type error".to_string(),
4760 ty_open(_) => "opened DST".to_string(),
4764 impl<'tcx> Repr<'tcx> for ty::type_err<'tcx> {
4765 fn repr(&self, tcx: &ty::ctxt<'tcx>) -> String {
4766 ty::type_err_to_str(tcx, self)
4770 /// Explains the source of a type err in a short, human readable way. This is meant to be placed
4771 /// in parentheses after some larger message. You should also invoke `note_and_explain_type_err()`
4772 /// afterwards to present additional details, particularly when it comes to lifetime-related
4774 pub fn type_err_to_str<'tcx>(cx: &ctxt<'tcx>, err: &type_err<'tcx>) -> String {
4776 terr_cyclic_ty => "cyclic type of infinite size".to_string(),
4777 terr_mismatch => "types differ".to_string(),
4778 terr_unsafety_mismatch(values) => {
4779 format!("expected {} fn, found {} fn",
4783 terr_abi_mismatch(values) => {
4784 format!("expected {} fn, found {} fn",
4788 terr_mutability => "values differ in mutability".to_string(),
4789 terr_box_mutability => {
4790 "boxed values differ in mutability".to_string()
4792 terr_vec_mutability => "vectors differ in mutability".to_string(),
4793 terr_ptr_mutability => "pointers differ in mutability".to_string(),
4794 terr_ref_mutability => "references differ in mutability".to_string(),
4795 terr_ty_param_size(values) => {
4796 format!("expected a type with {} type params, \
4797 found one with {} type params",
4801 terr_fixed_array_size(values) => {
4802 format!("expected an array with a fixed size of {} elements, \
4803 found one with {} elements",
4807 terr_tuple_size(values) => {
4808 format!("expected a tuple with {} elements, \
4809 found one with {} elements",
4814 "incorrect number of function parameters".to_string()
4816 terr_regions_does_not_outlive(..) => {
4817 "lifetime mismatch".to_string()
4819 terr_regions_not_same(..) => {
4820 "lifetimes are not the same".to_string()
4822 terr_regions_no_overlap(..) => {
4823 "lifetimes do not intersect".to_string()
4825 terr_regions_insufficiently_polymorphic(br, _) => {
4826 format!("expected bound lifetime parameter {}, \
4827 found concrete lifetime",
4828 bound_region_ptr_to_string(cx, br))
4830 terr_regions_overly_polymorphic(br, _) => {
4831 format!("expected concrete lifetime, \
4832 found bound lifetime parameter {}",
4833 bound_region_ptr_to_string(cx, br))
4835 terr_sorts(values) => {
4836 // A naive approach to making sure that we're not reporting silly errors such as:
4837 // (expected closure, found closure).
4838 let expected_str = ty_sort_string(cx, values.expected);
4839 let found_str = ty_sort_string(cx, values.found);
4840 if expected_str == found_str {
4841 format!("expected {}, found a different {}", expected_str, found_str)
4843 format!("expected {}, found {}", expected_str, found_str)
4846 terr_traits(values) => {
4847 format!("expected trait `{}`, found trait `{}`",
4848 item_path_str(cx, values.expected),
4849 item_path_str(cx, values.found))
4851 terr_builtin_bounds(values) => {
4852 if values.expected.is_empty() {
4853 format!("expected no bounds, found `{}`",
4854 values.found.user_string(cx))
4855 } else if values.found.is_empty() {
4856 format!("expected bounds `{}`, found no bounds",
4857 values.expected.user_string(cx))
4859 format!("expected bounds `{}`, found bounds `{}`",
4860 values.expected.user_string(cx),
4861 values.found.user_string(cx))
4864 terr_integer_as_char => {
4865 "expected an integral type, found `char`".to_string()
4867 terr_int_mismatch(ref values) => {
4868 format!("expected `{:?}`, found `{:?}`",
4872 terr_float_mismatch(ref values) => {
4873 format!("expected `{:?}`, found `{:?}`",
4877 terr_variadic_mismatch(ref values) => {
4878 format!("expected {} fn, found {} function",
4879 if values.expected { "variadic" } else { "non-variadic" },
4880 if values.found { "variadic" } else { "non-variadic" })
4882 terr_convergence_mismatch(ref values) => {
4883 format!("expected {} fn, found {} function",
4884 if values.expected { "converging" } else { "diverging" },
4885 if values.found { "converging" } else { "diverging" })
4887 terr_projection_name_mismatched(ref values) => {
4888 format!("expected {}, found {}",
4889 token::get_name(values.expected),
4890 token::get_name(values.found))
4892 terr_projection_bounds_length(ref values) => {
4893 format!("expected {} associated type bindings, found {}",
4900 pub fn note_and_explain_type_err(cx: &ctxt, err: &type_err) {
4902 terr_regions_does_not_outlive(subregion, superregion) => {
4903 note_and_explain_region(cx, "", subregion, "...");
4904 note_and_explain_region(cx, "...does not necessarily outlive ",
4907 terr_regions_not_same(region1, region2) => {
4908 note_and_explain_region(cx, "", region1, "...");
4909 note_and_explain_region(cx, "...is not the same lifetime as ",
4912 terr_regions_no_overlap(region1, region2) => {
4913 note_and_explain_region(cx, "", region1, "...");
4914 note_and_explain_region(cx, "...does not overlap ",
4917 terr_regions_insufficiently_polymorphic(_, conc_region) => {
4918 note_and_explain_region(cx,
4919 "concrete lifetime that was found is ",
4922 terr_regions_overly_polymorphic(_, ty::ReInfer(ty::ReVar(_))) => {
4923 // don't bother to print out the message below for
4924 // inference variables, it's not very illuminating.
4926 terr_regions_overly_polymorphic(_, conc_region) => {
4927 note_and_explain_region(cx,
4928 "expected concrete lifetime is ",
4935 pub fn provided_source(cx: &ctxt, id: ast::DefId) -> Option<ast::DefId> {
4936 cx.provided_method_sources.borrow().get(&id).map(|x| *x)
4939 pub fn provided_trait_methods<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
4940 -> Vec<Rc<Method<'tcx>>> {
4942 match cx.map.find(id.node) {
4943 Some(ast_map::NodeItem(item)) => {
4945 ItemTrait(_, _, _, ref ms) => {
4947 ast_util::split_trait_methods(&ms[]);
4950 match impl_or_trait_item(
4952 ast_util::local_def(m.id)) {
4953 MethodTraitItem(m) => m,
4954 TypeTraitItem(_) => {
4955 cx.sess.bug("provided_trait_methods(): \
4956 split_trait_methods() put \
4957 associated types in the \
4958 provided method bucket?!")
4964 cx.sess.bug(&format!("provided_trait_methods: `{:?}` is \
4971 cx.sess.bug(&format!("provided_trait_methods: `{:?}` is not a \
4977 csearch::get_provided_trait_methods(cx, id)
4981 /// Helper for looking things up in the various maps that are populated during
4982 /// typeck::collect (e.g., `cx.impl_or_trait_items`, `cx.tcache`, etc). All of
4983 /// these share the pattern that if the id is local, it should have been loaded
4984 /// into the map by the `typeck::collect` phase. If the def-id is external,
4985 /// then we have to go consult the crate loading code (and cache the result for
4987 fn lookup_locally_or_in_crate_store<V, F>(descr: &str,
4989 map: &mut DefIdMap<V>,
4990 load_external: F) -> V where
4994 match map.get(&def_id).cloned() {
4995 Some(v) => { return v; }
4999 if def_id.krate == ast::LOCAL_CRATE {
5000 panic!("No def'n found for {:?} in tcx.{}", def_id, descr);
5002 let v = load_external();
5003 map.insert(def_id, v.clone());
5007 pub fn trait_item<'tcx>(cx: &ctxt<'tcx>, trait_did: ast::DefId, idx: uint)
5008 -> ImplOrTraitItem<'tcx> {
5009 let method_def_id = (*ty::trait_item_def_ids(cx, trait_did))[idx].def_id();
5010 impl_or_trait_item(cx, method_def_id)
5013 pub fn trait_items<'tcx>(cx: &ctxt<'tcx>, trait_did: ast::DefId)
5014 -> Rc<Vec<ImplOrTraitItem<'tcx>>> {
5015 let mut trait_items = cx.trait_items_cache.borrow_mut();
5016 match trait_items.get(&trait_did).cloned() {
5017 Some(trait_items) => trait_items,
5019 let def_ids = ty::trait_item_def_ids(cx, trait_did);
5020 let items: Rc<Vec<ImplOrTraitItem>> =
5021 Rc::new(def_ids.iter()
5022 .map(|d| impl_or_trait_item(cx, d.def_id()))
5024 trait_items.insert(trait_did, items.clone());
5030 pub fn trait_impl_polarity<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5031 -> Option<ast::ImplPolarity> {
5032 if id.krate == ast::LOCAL_CRATE {
5033 match cx.map.find(id.node) {
5034 Some(ast_map::NodeItem(item)) => {
5036 ast::ItemImpl(_, polarity, _, _, _, _) => Some(polarity),
5043 csearch::get_impl_polarity(cx, id)
5047 pub fn impl_or_trait_item<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5048 -> ImplOrTraitItem<'tcx> {
5049 lookup_locally_or_in_crate_store("impl_or_trait_items",
5051 &mut *cx.impl_or_trait_items
5054 csearch::get_impl_or_trait_item(cx, id)
5058 /// Returns true if the given ID refers to an associated type and false if it
5059 /// refers to anything else.
5060 pub fn is_associated_type(cx: &ctxt, id: ast::DefId) -> bool {
5061 memoized(&cx.associated_types, id, |id: ast::DefId| {
5062 if id.krate == ast::LOCAL_CRATE {
5063 match cx.impl_or_trait_items.borrow().get(&id) {
5066 TypeTraitItem(_) => true,
5067 MethodTraitItem(_) => false,
5073 csearch::is_associated_type(&cx.sess.cstore, id)
5078 /// Returns the parameter index that the given associated type corresponds to.
5079 pub fn associated_type_parameter_index(cx: &ctxt,
5080 trait_def: &TraitDef,
5081 associated_type_id: ast::DefId)
5083 for type_parameter_def in trait_def.generics.types.iter() {
5084 if type_parameter_def.def_id == associated_type_id {
5085 return type_parameter_def.index as uint
5088 cx.sess.bug("couldn't find associated type parameter index")
5091 pub fn trait_item_def_ids(cx: &ctxt, id: ast::DefId)
5092 -> Rc<Vec<ImplOrTraitItemId>> {
5093 lookup_locally_or_in_crate_store("trait_item_def_ids",
5095 &mut *cx.trait_item_def_ids.borrow_mut(),
5097 Rc::new(csearch::get_trait_item_def_ids(&cx.sess.cstore, id))
5101 pub fn impl_trait_ref<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5102 -> Option<Rc<TraitRef<'tcx>>> {
5103 memoized(&cx.impl_trait_cache, id, |id: ast::DefId| {
5104 if id.krate == ast::LOCAL_CRATE {
5105 debug!("(impl_trait_ref) searching for trait impl {:?}", id);
5106 match cx.map.find(id.node) {
5107 Some(ast_map::NodeItem(item)) => {
5109 ast::ItemImpl(_, _, _, ref opt_trait, _, _) => {
5112 let trait_ref = ty::node_id_to_trait_ref(cx, t.ref_id);
5124 csearch::get_impl_trait(cx, id)
5129 pub fn trait_ref_to_def_id(tcx: &ctxt, tr: &ast::TraitRef) -> ast::DefId {
5130 let def = *tcx.def_map.borrow()
5132 .expect("no def-map entry for trait");
5136 pub fn try_add_builtin_trait(
5138 trait_def_id: ast::DefId,
5139 builtin_bounds: &mut EnumSet<BuiltinBound>)
5142 //! Checks whether `trait_ref` refers to one of the builtin
5143 //! traits, like `Send`, and adds the corresponding
5144 //! bound to the set `builtin_bounds` if so. Returns true if `trait_ref`
5145 //! is a builtin trait.
5147 match tcx.lang_items.to_builtin_kind(trait_def_id) {
5148 Some(bound) => { builtin_bounds.insert(bound); true }
5153 pub fn ty_to_def_id(ty: Ty) -> Option<ast::DefId> {
5156 Some(tt.principal_def_id()),
5159 ty_closure(id, _, _) =>
5168 pub struct VariantInfo<'tcx> {
5169 pub args: Vec<Ty<'tcx>>,
5170 pub arg_names: Option<Vec<ast::Ident>>,
5171 pub ctor_ty: Option<Ty<'tcx>>,
5172 pub name: ast::Name,
5178 impl<'tcx> VariantInfo<'tcx> {
5180 /// Creates a new VariantInfo from the corresponding ast representation.
5182 /// Does not do any caching of the value in the type context.
5183 pub fn from_ast_variant(cx: &ctxt<'tcx>,
5184 ast_variant: &ast::Variant,
5185 discriminant: Disr) -> VariantInfo<'tcx> {
5186 let ctor_ty = node_id_to_type(cx, ast_variant.node.id);
5188 match ast_variant.node.kind {
5189 ast::TupleVariantKind(ref args) => {
5190 let arg_tys = if args.len() > 0 {
5191 // the regions in the argument types come from the
5192 // enum def'n, and hence will all be early bound
5193 ty::no_late_bound_regions(cx, &ty_fn_args(ctor_ty)).unwrap()
5198 return VariantInfo {
5201 ctor_ty: Some(ctor_ty),
5202 name: ast_variant.node.name.name,
5203 id: ast_util::local_def(ast_variant.node.id),
5204 disr_val: discriminant,
5205 vis: ast_variant.node.vis
5208 ast::StructVariantKind(ref struct_def) => {
5209 let fields: &[StructField] = &struct_def.fields[];
5211 assert!(fields.len() > 0);
5213 let arg_tys = struct_def.fields.iter()
5214 .map(|field| node_id_to_type(cx, field.node.id)).collect();
5215 let arg_names = fields.iter().map(|field| {
5216 match field.node.kind {
5217 NamedField(ident, _) => ident,
5218 UnnamedField(..) => cx.sess.bug(
5219 "enum_variants: all fields in struct must have a name")
5223 return VariantInfo {
5225 arg_names: Some(arg_names),
5227 name: ast_variant.node.name.name,
5228 id: ast_util::local_def(ast_variant.node.id),
5229 disr_val: discriminant,
5230 vis: ast_variant.node.vis
5237 pub fn substd_enum_variants<'tcx>(cx: &ctxt<'tcx>,
5239 substs: &Substs<'tcx>)
5240 -> Vec<Rc<VariantInfo<'tcx>>> {
5241 enum_variants(cx, id).iter().map(|variant_info| {
5242 let substd_args = variant_info.args.iter()
5243 .map(|aty| aty.subst(cx, substs)).collect::<Vec<_>>();
5245 let substd_ctor_ty = variant_info.ctor_ty.subst(cx, substs);
5247 Rc::new(VariantInfo {
5249 ctor_ty: substd_ctor_ty,
5250 ..(**variant_info).clone()
5255 pub fn item_path_str(cx: &ctxt, id: ast::DefId) -> String {
5256 with_path(cx, id, |path| ast_map::path_to_string(path)).to_string()
5262 TraitDtor(DefId, bool)
5266 pub fn is_present(&self) -> bool {
5268 TraitDtor(..) => true,
5273 pub fn has_drop_flag(&self) -> bool {
5276 &TraitDtor(_, flag) => flag
5281 /* If struct_id names a struct with a dtor, return Some(the dtor's id).
5282 Otherwise return none. */
5283 pub fn ty_dtor(cx: &ctxt, struct_id: DefId) -> DtorKind {
5284 match cx.destructor_for_type.borrow().get(&struct_id) {
5285 Some(&method_def_id) => {
5286 let flag = !has_attr(cx, struct_id, "unsafe_no_drop_flag");
5288 TraitDtor(method_def_id, flag)
5294 pub fn has_dtor(cx: &ctxt, struct_id: DefId) -> bool {
5295 cx.destructor_for_type.borrow().contains_key(&struct_id)
5298 pub fn with_path<T, F>(cx: &ctxt, id: ast::DefId, f: F) -> T where
5299 F: FnOnce(ast_map::PathElems) -> T,
5301 if id.krate == ast::LOCAL_CRATE {
5302 cx.map.with_path(id.node, f)
5304 f(csearch::get_item_path(cx, id).iter().cloned().chain(None))
5308 pub fn enum_is_univariant(cx: &ctxt, id: ast::DefId) -> bool {
5309 enum_variants(cx, id).len() == 1
5312 pub fn type_is_empty(cx: &ctxt, ty: Ty) -> bool {
5314 ty_enum(did, _) => (*enum_variants(cx, did)).is_empty(),
5319 pub fn enum_variants<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5320 -> Rc<Vec<Rc<VariantInfo<'tcx>>>> {
5321 memoized(&cx.enum_var_cache, id, |id: ast::DefId| {
5322 if ast::LOCAL_CRATE != id.krate {
5323 Rc::new(csearch::get_enum_variants(cx, id))
5326 Although both this code and check_enum_variants in typeck/check
5327 call eval_const_expr, it should never get called twice for the same
5328 expr, since check_enum_variants also updates the enum_var_cache
5330 match cx.map.get(id.node) {
5331 ast_map::NodeItem(ref item) => {
5333 ast::ItemEnum(ref enum_definition, _) => {
5334 let mut last_discriminant: Option<Disr> = None;
5335 Rc::new(enum_definition.variants.iter().map(|variant| {
5337 let mut discriminant = match last_discriminant {
5338 Some(val) => val + 1,
5339 None => INITIAL_DISCRIMINANT_VALUE
5342 if let Some(ref e) = variant.node.disr_expr {
5343 // Preserve all values, and prefer signed.
5344 let ty = Some(cx.types.i64);
5345 match const_eval::eval_const_expr_partial(cx, &**e, ty) {
5346 Ok(const_eval::const_int(val)) => {
5347 discriminant = val as Disr;
5349 Ok(const_eval::const_uint(val)) => {
5350 discriminant = val as Disr;
5353 span_err!(cx.sess, e.span, E0304,
5354 "expected signed integer constant");
5357 span_err!(cx.sess, e.span, E0305,
5358 "expected constant: {}", err);
5363 last_discriminant = Some(discriminant);
5364 Rc::new(VariantInfo::from_ast_variant(cx, &**variant,
5369 cx.sess.bug("enum_variants: id not bound to an enum")
5373 _ => cx.sess.bug("enum_variants: id not bound to an enum")
5379 // Returns information about the enum variant with the given ID:
5380 pub fn enum_variant_with_id<'tcx>(cx: &ctxt<'tcx>,
5381 enum_id: ast::DefId,
5382 variant_id: ast::DefId)
5383 -> Rc<VariantInfo<'tcx>> {
5384 enum_variants(cx, enum_id).iter()
5385 .find(|variant| variant.id == variant_id)
5386 .expect("enum_variant_with_id(): no variant exists with that ID")
5391 // If the given item is in an external crate, looks up its type and adds it to
5392 // the type cache. Returns the type parameters and type.
5393 pub fn lookup_item_type<'tcx>(cx: &ctxt<'tcx>,
5395 -> TypeScheme<'tcx> {
5396 lookup_locally_or_in_crate_store(
5397 "tcache", did, &mut *cx.tcache.borrow_mut(),
5398 || csearch::get_type(cx, did))
5401 /// Given the did of a trait, returns its canonical trait ref.
5402 pub fn lookup_trait_def<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId)
5403 -> Rc<TraitDef<'tcx>> {
5404 memoized(&cx.trait_defs, did, |did: DefId| {
5405 assert!(did.krate != ast::LOCAL_CRATE);
5406 Rc::new(csearch::get_trait_def(cx, did))
5410 /// Given the did of a trait, returns its full set of predicates.
5411 pub fn lookup_predicates<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId)
5412 -> GenericPredicates<'tcx>
5414 memoized(&cx.predicates, did, |did: DefId| {
5415 assert!(did.krate != ast::LOCAL_CRATE);
5416 csearch::get_predicates(cx, did)
5420 /// Given a reference to a trait, returns the "superbounds" declared
5421 /// on the trait, with appropriate substitutions applied. Basically,
5422 /// this applies a filter to the where clauses on the trait, returning
5423 /// those that have the form:
5425 /// Self : SuperTrait<...>
5427 pub fn predicates_for_trait_ref<'tcx>(tcx: &ctxt<'tcx>,
5428 trait_ref: &PolyTraitRef<'tcx>)
5429 -> Vec<ty::Predicate<'tcx>>
5431 let trait_def = lookup_trait_def(tcx, trait_ref.def_id());
5433 debug!("bounds_for_trait_ref(trait_def={:?}, trait_ref={:?})",
5434 trait_def.repr(tcx), trait_ref.repr(tcx));
5436 // The interaction between HRTB and supertraits is not entirely
5437 // obvious. Let me walk you (and myself) through an example.
5439 // Let's start with an easy case. Consider two traits:
5441 // trait Foo<'a> : Bar<'a,'a> { }
5442 // trait Bar<'b,'c> { }
5444 // Now, if we have a trait reference `for<'x> T : Foo<'x>`, then
5445 // we can deduce that `for<'x> T : Bar<'x,'x>`. Basically, if we
5446 // knew that `Foo<'x>` (for any 'x) then we also know that
5447 // `Bar<'x,'x>` (for any 'x). This more-or-less falls out from
5448 // normal substitution.
5450 // In terms of why this is sound, the idea is that whenever there
5451 // is an impl of `T:Foo<'a>`, it must show that `T:Bar<'a,'a>`
5452 // holds. So if there is an impl of `T:Foo<'a>` that applies to
5453 // all `'a`, then we must know that `T:Bar<'a,'a>` holds for all
5456 // Another example to be careful of is this:
5458 // trait Foo1<'a> : for<'b> Bar1<'a,'b> { }
5459 // trait Bar1<'b,'c> { }
5461 // Here, if we have `for<'x> T : Foo1<'x>`, then what do we know?
5462 // The answer is that we know `for<'x,'b> T : Bar1<'x,'b>`. The
5463 // reason is similar to the previous example: any impl of
5464 // `T:Foo1<'x>` must show that `for<'b> T : Bar1<'x, 'b>`. So
5465 // basically we would want to collapse the bound lifetimes from
5466 // the input (`trait_ref`) and the supertraits.
5468 // To achieve this in practice is fairly straightforward. Let's
5469 // consider the more complicated scenario:
5471 // - We start out with `for<'x> T : Foo1<'x>`. In this case, `'x`
5472 // has a De Bruijn index of 1. We want to produce `for<'x,'b> T : Bar1<'x,'b>`,
5473 // where both `'x` and `'b` would have a DB index of 1.
5474 // The substitution from the input trait-ref is therefore going to be
5475 // `'a => 'x` (where `'x` has a DB index of 1).
5476 // - The super-trait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an
5477 // early-bound parameter and `'b' is a late-bound parameter with a
5479 // - If we replace `'a` with `'x` from the input, it too will have
5480 // a DB index of 1, and thus we'll have `for<'x,'b> Bar1<'x,'b>`
5481 // just as we wanted.
5483 // There is only one catch. If we just apply the substitution `'a
5484 // => 'x` to `for<'b> Bar1<'a,'b>`, the substitution code will
5485 // adjust the DB index because we substituting into a binder (it
5486 // tries to be so smart...) resulting in `for<'x> for<'b>
5487 // Bar1<'x,'b>` (we have no syntax for this, so use your
5488 // imagination). Basically the 'x will have DB index of 2 and 'b
5489 // will have DB index of 1. Not quite what we want. So we apply
5490 // the substitution to the *contents* of the trait reference,
5491 // rather than the trait reference itself (put another way, the
5492 // substitution code expects equal binding levels in the values
5493 // from the substitution and the value being substituted into, and
5494 // this trick achieves that).
5496 // Carefully avoid the binder introduced by each trait-ref by
5497 // substituting over the substs, not the trait-refs themselves,
5498 // thus achieving the "collapse" described in the big comment
5500 let trait_bounds: Vec<_> =
5501 trait_def.bounds.trait_bounds
5503 .map(|poly_trait_ref| ty::Binder(poly_trait_ref.0.subst(tcx, trait_ref.substs())))
5506 let projection_bounds: Vec<_> =
5507 trait_def.bounds.projection_bounds
5509 .map(|poly_proj| ty::Binder(poly_proj.0.subst(tcx, trait_ref.substs())))
5512 debug!("bounds_for_trait_ref: trait_bounds={} projection_bounds={}",
5513 trait_bounds.repr(tcx),
5514 projection_bounds.repr(tcx));
5516 // The region bounds and builtin bounds do not currently introduce
5517 // binders so we can just substitute in a straightforward way here.
5519 trait_def.bounds.region_bounds.subst(tcx, trait_ref.substs());
5520 let builtin_bounds =
5521 trait_def.bounds.builtin_bounds.subst(tcx, trait_ref.substs());
5523 let bounds = ty::ParamBounds {
5524 trait_bounds: trait_bounds,
5525 region_bounds: region_bounds,
5526 builtin_bounds: builtin_bounds,
5527 projection_bounds: projection_bounds,
5530 predicates(tcx, trait_ref.self_ty(), &bounds)
5533 pub fn predicates<'tcx>(
5536 bounds: &ParamBounds<'tcx>)
5537 -> Vec<Predicate<'tcx>>
5539 let mut vec = Vec::new();
5541 for builtin_bound in &bounds.builtin_bounds {
5542 match traits::trait_ref_for_builtin_bound(tcx, builtin_bound, param_ty) {
5543 Ok(trait_ref) => { vec.push(trait_ref.as_predicate()); }
5544 Err(ErrorReported) => { }
5548 for ®ion_bound in &bounds.region_bounds {
5549 // account for the binder being introduced below; no need to shift `param_ty`
5550 // because, at present at least, it can only refer to early-bound regions
5551 let region_bound = ty_fold::shift_region(region_bound, 1);
5552 vec.push(ty::Binder(ty::OutlivesPredicate(param_ty, region_bound)).as_predicate());
5555 for bound_trait_ref in &bounds.trait_bounds {
5556 vec.push(bound_trait_ref.as_predicate());
5559 for projection in &bounds.projection_bounds {
5560 vec.push(projection.as_predicate());
5566 /// Get the attributes of a definition.
5567 pub fn get_attrs<'tcx>(tcx: &'tcx ctxt, did: DefId)
5568 -> CowVec<'tcx, ast::Attribute> {
5570 let item = tcx.map.expect_item(did.node);
5571 Cow::Borrowed(&item.attrs[])
5573 Cow::Owned(csearch::get_item_attrs(&tcx.sess.cstore, did))
5577 /// Determine whether an item is annotated with an attribute
5578 pub fn has_attr(tcx: &ctxt, did: DefId, attr: &str) -> bool {
5579 get_attrs(tcx, did).iter().any(|item| item.check_name(attr))
5582 /// Determine whether an item is annotated with `#[repr(packed)]`
5583 pub fn lookup_packed(tcx: &ctxt, did: DefId) -> bool {
5584 lookup_repr_hints(tcx, did).contains(&attr::ReprPacked)
5587 /// Determine whether an item is annotated with `#[simd]`
5588 pub fn lookup_simd(tcx: &ctxt, did: DefId) -> bool {
5589 has_attr(tcx, did, "simd")
5592 /// Obtain the representation annotation for a struct definition.
5593 pub fn lookup_repr_hints(tcx: &ctxt, did: DefId) -> Rc<Vec<attr::ReprAttr>> {
5594 memoized(&tcx.repr_hint_cache, did, |did: DefId| {
5595 Rc::new(if did.krate == LOCAL_CRATE {
5596 get_attrs(tcx, did).iter().flat_map(|meta| {
5597 attr::find_repr_attrs(tcx.sess.diagnostic(), meta).into_iter()
5600 csearch::get_repr_attrs(&tcx.sess.cstore, did)
5605 // Look up a field ID, whether or not it's local
5606 // Takes a list of type substs in case the struct is generic
5607 pub fn lookup_field_type<'tcx>(tcx: &ctxt<'tcx>,
5610 substs: &Substs<'tcx>)
5612 let ty = if id.krate == ast::LOCAL_CRATE {
5613 node_id_to_type(tcx, id.node)
5615 let mut tcache = tcx.tcache.borrow_mut();
5616 let pty = tcache.entry(id).get().unwrap_or_else(
5617 |vacant_entry| vacant_entry.insert(csearch::get_field_type(tcx, struct_id, id)));
5620 ty.subst(tcx, substs)
5623 // Look up the list of field names and IDs for a given struct.
5624 // Panics if the id is not bound to a struct.
5625 pub fn lookup_struct_fields(cx: &ctxt, did: ast::DefId) -> Vec<field_ty> {
5626 if did.krate == ast::LOCAL_CRATE {
5627 let struct_fields = cx.struct_fields.borrow();
5628 match struct_fields.get(&did) {
5629 Some(fields) => (**fields).clone(),
5632 &format!("ID not mapped to struct fields: {}",
5633 cx.map.node_to_string(did.node))[]);
5637 csearch::get_struct_fields(&cx.sess.cstore, did)
5641 pub fn is_tuple_struct(cx: &ctxt, did: ast::DefId) -> bool {
5642 let fields = lookup_struct_fields(cx, did);
5643 !fields.is_empty() && fields.iter().all(|f| f.name == token::special_names::unnamed_field)
5646 // Returns a list of fields corresponding to the struct's items. trans uses
5647 // this. Takes a list of substs with which to instantiate field types.
5648 pub fn struct_fields<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId, substs: &Substs<'tcx>)
5649 -> Vec<field<'tcx>> {
5650 lookup_struct_fields(cx, did).iter().map(|f| {
5654 ty: lookup_field_type(cx, did, f.id, substs),
5661 // Returns a list of fields corresponding to the tuple's items. trans uses
5663 pub fn tup_fields<'tcx>(v: &[Ty<'tcx>]) -> Vec<field<'tcx>> {
5664 v.iter().enumerate().map(|(i, &f)| {
5666 name: token::intern(&i.to_string()[]),
5675 #[derive(Copy, Clone)]
5676 pub struct ClosureUpvar<'tcx> {
5682 // Returns a list of `ClosureUpvar`s for each upvar.
5683 pub fn closure_upvars<'tcx>(typer: &mc::Typer<'tcx>,
5684 closure_id: ast::DefId,
5685 substs: &Substs<'tcx>)
5686 -> Option<Vec<ClosureUpvar<'tcx>>>
5688 // Presently an unboxed closure type cannot "escape" out of a
5689 // function, so we will only encounter ones that originated in the
5690 // local crate or were inlined into it along with some function.
5691 // This may change if abstract return types of some sort are
5693 assert!(closure_id.krate == ast::LOCAL_CRATE);
5694 let tcx = typer.tcx();
5695 match tcx.freevars.borrow().get(&closure_id.node) {
5696 None => Some(vec![]),
5697 Some(ref freevars) => {
5700 let freevar_def_id = freevar.def.def_id();
5701 let freevar_ty = match typer.node_ty(freevar_def_id.node) {
5703 Err(()) => { return None; }
5705 let freevar_ty = freevar_ty.subst(tcx, substs);
5707 let upvar_id = ty::UpvarId {
5708 var_id: freevar_def_id.node,
5709 closure_expr_id: closure_id.node
5712 typer.upvar_capture(upvar_id).map(|capture| {
5713 let freevar_ref_ty = match capture {
5714 UpvarCapture::ByValue => {
5717 UpvarCapture::ByRef(borrow) => {
5719 tcx.mk_region(borrow.region),
5722 mutbl: borrow.kind.to_mutbl_lossy(),
5739 pub fn is_binopable<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>, op: ast::BinOp) -> bool {
5740 #![allow(non_upper_case_globals)]
5741 static tycat_other: int = 0;
5742 static tycat_bool: int = 1;
5743 static tycat_char: int = 2;
5744 static tycat_int: int = 3;
5745 static tycat_float: int = 4;
5746 static tycat_raw_ptr: int = 6;
5748 static opcat_add: int = 0;
5749 static opcat_sub: int = 1;
5750 static opcat_mult: int = 2;
5751 static opcat_shift: int = 3;
5752 static opcat_rel: int = 4;
5753 static opcat_eq: int = 5;
5754 static opcat_bit: int = 6;
5755 static opcat_logic: int = 7;
5756 static opcat_mod: int = 8;
5758 fn opcat(op: ast::BinOp) -> int {
5760 ast::BiAdd => opcat_add,
5761 ast::BiSub => opcat_sub,
5762 ast::BiMul => opcat_mult,
5763 ast::BiDiv => opcat_mult,
5764 ast::BiRem => opcat_mod,
5765 ast::BiAnd => opcat_logic,
5766 ast::BiOr => opcat_logic,
5767 ast::BiBitXor => opcat_bit,
5768 ast::BiBitAnd => opcat_bit,
5769 ast::BiBitOr => opcat_bit,
5770 ast::BiShl => opcat_shift,
5771 ast::BiShr => opcat_shift,
5772 ast::BiEq => opcat_eq,
5773 ast::BiNe => opcat_eq,
5774 ast::BiLt => opcat_rel,
5775 ast::BiLe => opcat_rel,
5776 ast::BiGe => opcat_rel,
5777 ast::BiGt => opcat_rel
5781 fn tycat<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> int {
5782 if type_is_simd(cx, ty) {
5783 return tycat(cx, simd_type(cx, ty))
5786 ty_char => tycat_char,
5787 ty_bool => tycat_bool,
5788 ty_int(_) | ty_uint(_) | ty_infer(IntVar(_)) => tycat_int,
5789 ty_float(_) | ty_infer(FloatVar(_)) => tycat_float,
5790 ty_ptr(_) => tycat_raw_ptr,
5795 static t: bool = true;
5796 static f: bool = false;
5799 // +, -, *, shift, rel, ==, bit, logic, mod
5800 /*other*/ [f, f, f, f, f, f, f, f, f],
5801 /*bool*/ [f, f, f, f, t, t, t, t, f],
5802 /*char*/ [f, f, f, f, t, t, f, f, f],
5803 /*int*/ [t, t, t, t, t, t, t, f, t],
5804 /*float*/ [t, t, t, f, t, t, f, f, f],
5805 /*bot*/ [t, t, t, t, t, t, t, t, t],
5806 /*raw ptr*/ [f, f, f, f, t, t, f, f, f]];
5808 return tbl[tycat(cx, ty) as uint ][opcat(op) as uint];
5811 // Returns the repeat count for a repeating vector expression.
5812 pub fn eval_repeat_count(tcx: &ctxt, count_expr: &ast::Expr) -> uint {
5813 match const_eval::eval_const_expr_partial(tcx, count_expr, Some(tcx.types.uint)) {
5815 let found = match val {
5816 const_eval::const_uint(count) => return count as uint,
5817 const_eval::const_int(count) if count >= 0 => return count as uint,
5818 const_eval::const_int(_) =>
5820 const_eval::const_float(_) =>
5822 const_eval::const_str(_) =>
5824 const_eval::const_bool(_) =>
5826 const_eval::const_binary(_) =>
5829 span_err!(tcx.sess, count_expr.span, E0306,
5830 "expected positive integer for repeat count, found {}",
5834 let found = match count_expr.node {
5835 ast::ExprPath(ast::Path {
5839 }) if segments.len() == 1 =>
5842 "non-constant expression"
5844 span_err!(tcx.sess, count_expr.span, E0307,
5845 "expected constant integer for repeat count, found {}",
5852 // Iterate over a type parameter's bounded traits and any supertraits
5853 // of those traits, ignoring kinds.
5854 // Here, the supertraits are the transitive closure of the supertrait
5855 // relation on the supertraits from each bounded trait's constraint
5857 pub fn each_bound_trait_and_supertraits<'tcx, F>(tcx: &ctxt<'tcx>,
5858 bounds: &[PolyTraitRef<'tcx>],
5861 F: FnMut(PolyTraitRef<'tcx>) -> bool,
5863 for bound_trait_ref in traits::transitive_bounds(tcx, bounds) {
5864 if !f(bound_trait_ref) {
5871 /// Given a set of predicates that apply to an object type, returns
5872 /// the region bounds that the (erased) `Self` type must
5873 /// outlive. Precisely *because* the `Self` type is erased, the
5874 /// parameter `erased_self_ty` must be supplied to indicate what type
5875 /// has been used to represent `Self` in the predicates
5876 /// themselves. This should really be a unique type; `FreshTy(0)` is a
5879 /// Requires that trait definitions have been processed so that we can
5880 /// elaborate predicates and walk supertraits.
5881 pub fn required_region_bounds<'tcx>(tcx: &ctxt<'tcx>,
5882 erased_self_ty: Ty<'tcx>,
5883 predicates: Vec<ty::Predicate<'tcx>>)
5886 debug!("required_region_bounds(erased_self_ty={:?}, predicates={:?})",
5887 erased_self_ty.repr(tcx),
5888 predicates.repr(tcx));
5890 assert!(!erased_self_ty.has_escaping_regions());
5892 traits::elaborate_predicates(tcx, predicates)
5893 .filter_map(|predicate| {
5895 ty::Predicate::Projection(..) |
5896 ty::Predicate::Trait(..) |
5897 ty::Predicate::Equate(..) |
5898 ty::Predicate::RegionOutlives(..) => {
5901 ty::Predicate::TypeOutlives(ty::Binder(ty::OutlivesPredicate(t, r))) => {
5902 // Search for a bound of the form `erased_self_ty
5903 // : 'a`, but be wary of something like `for<'a>
5904 // erased_self_ty : 'a` (we interpret a
5905 // higher-ranked bound like that as 'static,
5906 // though at present the code in `fulfill.rs`
5907 // considers such bounds to be unsatisfiable, so
5908 // it's kind of a moot point since you could never
5909 // construct such an object, but this seems
5910 // correct even if that code changes).
5911 if t == erased_self_ty && !r.has_escaping_regions() {
5912 if r.has_escaping_regions() {
5926 pub fn get_tydesc_ty<'tcx>(tcx: &ctxt<'tcx>) -> Result<Ty<'tcx>, String> {
5927 tcx.lang_items.require(TyDescStructLangItem).map(|tydesc_lang_item| {
5928 tcx.intrinsic_defs.borrow().get(&tydesc_lang_item).cloned()
5929 .expect("Failed to resolve TyDesc")
5933 pub fn item_variances(tcx: &ctxt, item_id: ast::DefId) -> Rc<ItemVariances> {
5934 lookup_locally_or_in_crate_store(
5935 "item_variance_map", item_id, &mut *tcx.item_variance_map.borrow_mut(),
5936 || Rc::new(csearch::get_item_variances(&tcx.sess.cstore, item_id)))
5939 /// Records a trait-to-implementation mapping.
5940 pub fn record_trait_implementation(tcx: &ctxt,
5941 trait_def_id: DefId,
5942 impl_def_id: DefId) {
5944 match tcx.trait_impls.borrow().get(&trait_def_id) {
5945 Some(impls_for_trait) => {
5946 impls_for_trait.borrow_mut().push(impl_def_id);
5952 tcx.trait_impls.borrow_mut().insert(trait_def_id, Rc::new(RefCell::new(vec!(impl_def_id))));
5955 /// Populates the type context with all the implementations for the given type
5957 pub fn populate_implementations_for_type_if_necessary(tcx: &ctxt,
5958 type_id: ast::DefId) {
5959 if type_id.krate == LOCAL_CRATE {
5962 if tcx.populated_external_types.borrow().contains(&type_id) {
5966 debug!("populate_implementations_for_type_if_necessary: searching for {:?}", type_id);
5968 let mut inherent_impls = Vec::new();
5969 csearch::each_implementation_for_type(&tcx.sess.cstore, type_id,
5971 let impl_items = csearch::get_impl_items(&tcx.sess.cstore, impl_def_id);
5973 // Record the trait->implementation mappings, if applicable.
5974 let associated_traits = csearch::get_impl_trait(tcx, impl_def_id);
5975 if let Some(ref trait_ref) = associated_traits {
5976 record_trait_implementation(tcx, trait_ref.def_id, impl_def_id);
5979 // For any methods that use a default implementation, add them to
5980 // the map. This is a bit unfortunate.
5981 for impl_item_def_id in &impl_items {
5982 let method_def_id = impl_item_def_id.def_id();
5983 match impl_or_trait_item(tcx, method_def_id) {
5984 MethodTraitItem(method) => {
5985 if let Some(source) = method.provided_source {
5986 tcx.provided_method_sources
5988 .insert(method_def_id, source);
5991 TypeTraitItem(_) => {}
5995 // Store the implementation info.
5996 tcx.impl_items.borrow_mut().insert(impl_def_id, impl_items);
5998 // If this is an inherent implementation, record it.
5999 if associated_traits.is_none() {
6000 inherent_impls.push(impl_def_id);
6004 tcx.inherent_impls.borrow_mut().insert(type_id, Rc::new(inherent_impls));
6005 tcx.populated_external_types.borrow_mut().insert(type_id);
6008 /// Populates the type context with all the implementations for the given
6009 /// trait if necessary.
6010 pub fn populate_implementations_for_trait_if_necessary(
6012 trait_id: ast::DefId) {
6013 if trait_id.krate == LOCAL_CRATE {
6016 if tcx.populated_external_traits.borrow().contains(&trait_id) {
6020 csearch::each_implementation_for_trait(&tcx.sess.cstore, trait_id,
6021 |implementation_def_id| {
6022 let impl_items = csearch::get_impl_items(&tcx.sess.cstore, implementation_def_id);
6024 // Record the trait->implementation mapping.
6025 record_trait_implementation(tcx, trait_id, implementation_def_id);
6027 // For any methods that use a default implementation, add them to
6028 // the map. This is a bit unfortunate.
6029 for impl_item_def_id in &impl_items {
6030 let method_def_id = impl_item_def_id.def_id();
6031 match impl_or_trait_item(tcx, method_def_id) {
6032 MethodTraitItem(method) => {
6033 if let Some(source) = method.provided_source {
6034 tcx.provided_method_sources
6036 .insert(method_def_id, source);
6039 TypeTraitItem(_) => {}
6043 // Store the implementation info.
6044 tcx.impl_items.borrow_mut().insert(implementation_def_id, impl_items);
6047 tcx.populated_external_traits.borrow_mut().insert(trait_id);
6050 /// Given the def_id of an impl, return the def_id of the trait it implements.
6051 /// If it implements no trait, return `None`.
6052 pub fn trait_id_of_impl(tcx: &ctxt,
6054 -> Option<ast::DefId> {
6055 ty::impl_trait_ref(tcx, def_id).map(|tr| tr.def_id)
6058 /// If the given def ID describes a method belonging to an impl, return the
6059 /// ID of the impl that the method belongs to. Otherwise, return `None`.
6060 pub fn impl_of_method(tcx: &ctxt, def_id: ast::DefId)
6061 -> Option<ast::DefId> {
6062 if def_id.krate != LOCAL_CRATE {
6063 return match csearch::get_impl_or_trait_item(tcx,
6064 def_id).container() {
6065 TraitContainer(_) => None,
6066 ImplContainer(def_id) => Some(def_id),
6069 match tcx.impl_or_trait_items.borrow().get(&def_id).cloned() {
6070 Some(trait_item) => {
6071 match trait_item.container() {
6072 TraitContainer(_) => None,
6073 ImplContainer(def_id) => Some(def_id),
6080 /// If the given def ID describes an item belonging to a trait (either a
6081 /// default method or an implementation of a trait method), return the ID of
6082 /// the trait that the method belongs to. Otherwise, return `None`.
6083 pub fn trait_of_item(tcx: &ctxt, def_id: ast::DefId) -> Option<ast::DefId> {
6084 if def_id.krate != LOCAL_CRATE {
6085 return csearch::get_trait_of_item(&tcx.sess.cstore, def_id, tcx);
6087 match tcx.impl_or_trait_items.borrow().get(&def_id).cloned() {
6088 Some(impl_or_trait_item) => {
6089 match impl_or_trait_item.container() {
6090 TraitContainer(def_id) => Some(def_id),
6091 ImplContainer(def_id) => trait_id_of_impl(tcx, def_id),
6098 /// If the given def ID describes an item belonging to a trait, (either a
6099 /// default method or an implementation of a trait method), return the ID of
6100 /// the method inside trait definition (this means that if the given def ID
6101 /// is already that of the original trait method, then the return value is
6103 /// Otherwise, return `None`.
6104 pub fn trait_item_of_item(tcx: &ctxt, def_id: ast::DefId)
6105 -> Option<ImplOrTraitItemId> {
6106 let impl_item = match tcx.impl_or_trait_items.borrow().get(&def_id) {
6107 Some(m) => m.clone(),
6108 None => return None,
6110 let name = impl_item.name();
6111 match trait_of_item(tcx, def_id) {
6112 Some(trait_did) => {
6113 let trait_items = ty::trait_items(tcx, trait_did);
6115 .position(|m| m.name() == name)
6116 .map(|idx| ty::trait_item(tcx, trait_did, idx).id())
6122 /// Creates a hash of the type `Ty` which will be the same no matter what crate
6123 /// context it's calculated within. This is used by the `type_id` intrinsic.
6124 pub fn hash_crate_independent<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>, svh: &Svh) -> u64 {
6125 let mut state = SipHasher::new();
6126 helper(tcx, ty, svh, &mut state);
6127 return state.finish();
6129 fn helper<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>, svh: &Svh,
6130 state: &mut SipHasher) {
6131 macro_rules! byte { ($b:expr) => { ($b as u8).hash(state) } }
6132 macro_rules! hash { ($e:expr) => { $e.hash(state) } }
6134 let region = |state: &mut SipHasher, r: Region| {
6137 ReLateBound(db, BrAnon(i)) => {
6147 tcx.sess.bug("unexpected region found when hashing a type")
6151 let did = |state: &mut SipHasher, did: DefId| {
6152 let h = if ast_util::is_local(did) {
6155 tcx.sess.cstore.get_crate_hash(did.krate)
6157 h.as_str().hash(state);
6158 did.node.hash(state);
6160 let mt = |state: &mut SipHasher, mt: mt| {
6161 mt.mutbl.hash(state);
6163 let fn_sig = |state: &mut SipHasher, sig: &Binder<FnSig<'tcx>>| {
6164 let sig = anonymize_late_bound_regions(tcx, sig).0;
6165 for a in &sig.inputs { helper(tcx, *a, svh, state); }
6166 if let ty::FnConverging(output) = sig.output {
6167 helper(tcx, output, svh, state);
6170 maybe_walk_ty(ty, |ty| {
6172 ty_bool => byte!(2),
6173 ty_char => byte!(3),
6196 ty_vec(_, Some(n)) => {
6200 ty_vec(_, None) => {
6212 ty_bare_fn(opt_def_id, ref b) => {
6217 fn_sig(state, &b.sig);
6220 ty_trait(ref data) => {
6222 did(state, data.principal_def_id());
6225 let principal = anonymize_late_bound_regions(tcx, &data.principal).0;
6226 for subty in principal.substs.types.iter() {
6227 helper(tcx, *subty, svh, state);
6232 ty_struct(d, _) => {
6236 ty_tup(ref inner) => {
6244 hash!(token::get_name(p.name));
6246 ty_open(_) => byte!(22),
6247 ty_infer(_) => unreachable!(),
6248 ty_err => byte!(23),
6249 ty_closure(d, r, _) => {
6254 ty_projection(ref data) => {
6256 did(state, data.trait_ref.def_id);
6257 hash!(token::get_name(data.item_name));
6266 pub fn to_string(self) -> &'static str {
6269 Contravariant => "-",
6276 /// Construct a parameter environment suitable for static contexts or other contexts where there
6277 /// are no free type/lifetime parameters in scope.
6278 pub fn empty_parameter_environment<'a,'tcx>(cx: &'a ctxt<'tcx>) -> ParameterEnvironment<'a,'tcx> {
6279 ty::ParameterEnvironment { tcx: cx,
6280 free_substs: Substs::empty(),
6281 caller_bounds: Vec::new(),
6282 implicit_region_bound: ty::ReEmpty,
6283 selection_cache: traits::SelectionCache::new(), }
6286 /// Constructs and returns a substitution that can be applied to move from
6287 /// the "outer" view of a type or method to the "inner" view.
6288 /// In general, this means converting from bound parameters to
6289 /// free parameters. Since we currently represent bound/free type
6290 /// parameters in the same way, this only has an effect on regions.
6291 pub fn construct_free_substs<'a,'tcx>(
6292 tcx: &'a ctxt<'tcx>,
6293 generics: &Generics<'tcx>,
6294 free_id: ast::NodeId)
6298 let mut types = VecPerParamSpace::empty();
6299 push_types_from_defs(tcx, &mut types, generics.types.as_slice());
6301 let free_id_outlive = region::DestructionScopeData::new(free_id);
6303 // map bound 'a => free 'a
6304 let mut regions = VecPerParamSpace::empty();
6305 push_region_params(&mut regions, free_id_outlive, generics.regions.as_slice());
6309 regions: subst::NonerasedRegions(regions)
6312 fn push_region_params(regions: &mut VecPerParamSpace<ty::Region>,
6313 all_outlive_extent: region::DestructionScopeData,
6314 region_params: &[RegionParameterDef])
6316 for r in region_params {
6317 regions.push(r.space, ty::free_region_from_def(all_outlive_extent, r));
6321 fn push_types_from_defs<'tcx>(tcx: &ty::ctxt<'tcx>,
6322 types: &mut VecPerParamSpace<Ty<'tcx>>,
6323 defs: &[TypeParameterDef<'tcx>]) {
6325 debug!("construct_parameter_environment(): push_types_from_defs: def={:?}",
6327 let ty = ty::mk_param_from_def(tcx, def);
6328 types.push(def.space, ty);
6333 /// See `ParameterEnvironment` struct def'n for details
6334 pub fn construct_parameter_environment<'a,'tcx>(
6335 tcx: &'a ctxt<'tcx>,
6337 generics: &ty::Generics<'tcx>,
6338 generic_predicates: &ty::GenericPredicates<'tcx>,
6339 free_id: ast::NodeId)
6340 -> ParameterEnvironment<'a, 'tcx>
6343 // Construct the free substs.
6346 let free_substs = construct_free_substs(tcx, generics, free_id);
6347 let free_id_outlive = region::DestructionScopeData::new(free_id);
6350 // Compute the bounds on Self and the type parameters.
6353 let bounds = generic_predicates.instantiate(tcx, &free_substs);
6354 let bounds = liberate_late_bound_regions(tcx, free_id_outlive, &ty::Binder(bounds));
6355 let predicates = bounds.predicates.into_vec();
6358 // Compute region bounds. For now, these relations are stored in a
6359 // global table on the tcx, so just enter them there. I'm not
6360 // crazy about this scheme, but it's convenient, at least.
6363 record_region_bounds(tcx, &*predicates);
6365 debug!("construct_parameter_environment: free_id={:?} free_subst={:?} predicates={:?}",
6367 free_substs.repr(tcx),
6368 predicates.repr(tcx));
6371 // Finally, we have to normalize the bounds in the environment, in
6372 // case they contain any associated type projections. This process
6373 // can yield errors if the put in illegal associated types, like
6374 // `<i32 as Foo>::Bar` where `i32` does not implement `Foo`. We
6375 // report these errors right here; this doesn't actually feel
6376 // right to me, because constructing the environment feels like a
6377 // kind of a "idempotent" action, but I'm not sure where would be
6378 // a better place. In practice, we construct environments for
6379 // every fn once during type checking, and we'll abort if there
6380 // are any errors at that point, so after type checking you can be
6381 // sure that this will succeed without errors anyway.
6384 let unnormalized_env = ty::ParameterEnvironment {
6386 free_substs: free_substs,
6387 implicit_region_bound: ty::ReScope(free_id_outlive.to_code_extent()),
6388 caller_bounds: predicates,
6389 selection_cache: traits::SelectionCache::new(),
6392 let cause = traits::ObligationCause::misc(span, free_id);
6393 return traits::normalize_param_env_or_error(unnormalized_env, cause);
6395 fn record_region_bounds<'tcx>(tcx: &ty::ctxt<'tcx>, predicates: &[ty::Predicate<'tcx>]) {
6396 debug!("record_region_bounds(predicates={:?})", predicates.repr(tcx));
6398 for predicate in predicates {
6400 Predicate::Projection(..) |
6401 Predicate::Trait(..) |
6402 Predicate::Equate(..) |
6403 Predicate::TypeOutlives(..) => {
6404 // No region bounds here
6406 Predicate::RegionOutlives(ty::Binder(ty::OutlivesPredicate(r_a, r_b))) => {
6408 (ty::ReFree(fr_a), ty::ReFree(fr_b)) => {
6409 // Record that `'a:'b`. Or, put another way, `'b <= 'a`.
6410 tcx.region_maps.relate_free_regions(fr_b, fr_a);
6413 // All named regions are instantiated with free regions.
6415 &format!("record_region_bounds: non free region: {} / {}",
6427 pub fn from_mutbl(m: ast::Mutability) -> BorrowKind {
6429 ast::MutMutable => MutBorrow,
6430 ast::MutImmutable => ImmBorrow,
6434 /// Returns a mutability `m` such that an `&m T` pointer could be used to obtain this borrow
6435 /// kind. Because borrow kinds are richer than mutabilities, we sometimes have to pick a
6436 /// mutability that is stronger than necessary so that it at least *would permit* the borrow in
6438 pub fn to_mutbl_lossy(self) -> ast::Mutability {
6440 MutBorrow => ast::MutMutable,
6441 ImmBorrow => ast::MutImmutable,
6443 // We have no type corresponding to a unique imm borrow, so
6444 // use `&mut`. It gives all the capabilities of an `&uniq`
6445 // and hence is a safe "over approximation".
6446 UniqueImmBorrow => ast::MutMutable,
6450 pub fn to_user_str(&self) -> &'static str {
6452 MutBorrow => "mutable",
6453 ImmBorrow => "immutable",
6454 UniqueImmBorrow => "uniquely immutable",
6459 impl<'tcx> ctxt<'tcx> {
6460 pub fn is_method_call(&self, expr_id: ast::NodeId) -> bool {
6461 self.method_map.borrow().contains_key(&MethodCall::expr(expr_id))
6464 pub fn upvar_capture(&self, upvar_id: ty::UpvarId) -> Option<ty::UpvarCapture> {
6465 Some(self.upvar_capture_map.borrow()[upvar_id].clone())
6469 impl<'a,'tcx> mc::Typer<'tcx> for ParameterEnvironment<'a,'tcx> {
6470 fn node_ty(&self, id: ast::NodeId) -> mc::McResult<Ty<'tcx>> {
6471 Ok(ty::node_id_to_type(self.tcx, id))
6474 fn expr_ty_adjusted(&self, expr: &ast::Expr) -> mc::McResult<Ty<'tcx>> {
6475 Ok(ty::expr_ty_adjusted(self.tcx, expr))
6478 fn node_method_ty(&self, method_call: ty::MethodCall) -> Option<Ty<'tcx>> {
6479 self.tcx.method_map.borrow().get(&method_call).map(|method| method.ty)
6482 fn node_method_origin(&self, method_call: ty::MethodCall)
6483 -> Option<ty::MethodOrigin<'tcx>>
6485 self.tcx.method_map.borrow().get(&method_call).map(|method| method.origin.clone())
6488 fn adjustments(&self) -> &RefCell<NodeMap<ty::AutoAdjustment<'tcx>>> {
6489 &self.tcx.adjustments
6492 fn is_method_call(&self, id: ast::NodeId) -> bool {
6493 self.tcx.is_method_call(id)
6496 fn temporary_scope(&self, rvalue_id: ast::NodeId) -> Option<region::CodeExtent> {
6497 self.tcx.region_maps.temporary_scope(rvalue_id)
6500 fn upvar_capture(&self, upvar_id: ty::UpvarId) -> Option<ty::UpvarCapture> {
6501 self.tcx.upvar_capture(upvar_id)
6504 fn type_moves_by_default(&self, span: Span, ty: Ty<'tcx>) -> bool {
6505 type_moves_by_default(self, span, ty)
6509 impl<'a,'tcx> ClosureTyper<'tcx> for ty::ParameterEnvironment<'a,'tcx> {
6510 fn param_env<'b>(&'b self) -> &'b ty::ParameterEnvironment<'b,'tcx> {
6514 fn closure_kind(&self,
6516 -> Option<ty::ClosureKind>
6518 Some(self.tcx.closure_kind(def_id))
6521 fn closure_type(&self,
6523 substs: &subst::Substs<'tcx>)
6524 -> ty::ClosureTy<'tcx>
6526 self.tcx.closure_type(def_id, substs)
6529 fn closure_upvars(&self,
6531 substs: &Substs<'tcx>)
6532 -> Option<Vec<ClosureUpvar<'tcx>>>
6534 closure_upvars(self, def_id, substs)
6539 /// The category of explicit self.
6540 #[derive(Clone, Copy, Eq, PartialEq, Debug)]
6541 pub enum ExplicitSelfCategory {
6542 StaticExplicitSelfCategory,
6543 ByValueExplicitSelfCategory,
6544 ByReferenceExplicitSelfCategory(Region, ast::Mutability),
6545 ByBoxExplicitSelfCategory,
6548 /// Pushes all the lifetimes in the given type onto the given list. A
6549 /// "lifetime in a type" is a lifetime specified by a reference or a lifetime
6550 /// in a list of type substitutions. This does *not* traverse into nominal
6551 /// types, nor does it resolve fictitious types.
6552 pub fn accumulate_lifetimes_in_type(accumulator: &mut Vec<ty::Region>,
6556 ty_rptr(region, _) => {
6557 accumulator.push(*region)
6559 ty_trait(ref t) => {
6560 accumulator.push_all(t.principal.0.substs.regions().as_slice());
6562 ty_enum(_, substs) |
6563 ty_struct(_, substs) => {
6564 accum_substs(accumulator, substs);
6566 ty_closure(_, region, substs) => {
6567 accumulator.push(*region);
6568 accum_substs(accumulator, substs);
6590 fn accum_substs(accumulator: &mut Vec<Region>, substs: &Substs) {
6591 match substs.regions {
6592 subst::ErasedRegions => {}
6593 subst::NonerasedRegions(ref regions) => {
6594 for region in regions.iter() {
6595 accumulator.push(*region)
6602 /// A free variable referred to in a function.
6603 #[derive(Copy, RustcEncodable, RustcDecodable)]
6604 pub struct Freevar {
6605 /// The variable being accessed free.
6608 // First span where it is accessed (there can be multiple).
6612 pub type FreevarMap = NodeMap<Vec<Freevar>>;
6614 pub type CaptureModeMap = NodeMap<ast::CaptureClause>;
6616 // Trait method resolution
6617 pub type TraitMap = NodeMap<Vec<DefId>>;
6619 // Map from the NodeId of a glob import to a list of items which are actually
6621 pub type GlobMap = HashMap<NodeId, HashSet<Name>>;
6623 pub fn with_freevars<T, F>(tcx: &ty::ctxt, fid: ast::NodeId, f: F) -> T where
6624 F: FnOnce(&[Freevar]) -> T,
6626 match tcx.freevars.borrow().get(&fid) {
6632 impl<'tcx> AutoAdjustment<'tcx> {
6633 pub fn is_identity(&self) -> bool {
6635 AdjustReifyFnPointer(..) => false,
6636 AdjustDerefRef(ref r) => r.is_identity(),
6641 impl<'tcx> AutoDerefRef<'tcx> {
6642 pub fn is_identity(&self) -> bool {
6643 self.autoderefs == 0 && self.autoref.is_none()
6647 /// Replace any late-bound regions bound in `value` with free variants attached to scope-id
6649 pub fn liberate_late_bound_regions<'tcx, T>(
6650 tcx: &ty::ctxt<'tcx>,
6651 all_outlive_scope: region::DestructionScopeData,
6654 where T : TypeFoldable<'tcx> + Repr<'tcx>
6656 replace_late_bound_regions(
6658 |br| ty::ReFree(ty::FreeRegion{scope: all_outlive_scope, bound_region: br})).0
6661 pub fn count_late_bound_regions<'tcx, T>(
6662 tcx: &ty::ctxt<'tcx>,
6665 where T : TypeFoldable<'tcx> + Repr<'tcx>
6667 let (_, skol_map) = replace_late_bound_regions(tcx, value, |_| ty::ReStatic);
6671 pub fn binds_late_bound_regions<'tcx, T>(
6672 tcx: &ty::ctxt<'tcx>,
6675 where T : TypeFoldable<'tcx> + Repr<'tcx>
6677 count_late_bound_regions(tcx, value) > 0
6680 pub fn no_late_bound_regions<'tcx, T>(
6681 tcx: &ty::ctxt<'tcx>,
6684 where T : TypeFoldable<'tcx> + Repr<'tcx> + Clone
6686 if binds_late_bound_regions(tcx, value) {
6689 Some(value.0.clone())
6693 /// Replace any late-bound regions bound in `value` with `'static`. Useful in trans but also
6694 /// method lookup and a few other places where precise region relationships are not required.
6695 pub fn erase_late_bound_regions<'tcx, T>(
6696 tcx: &ty::ctxt<'tcx>,
6699 where T : TypeFoldable<'tcx> + Repr<'tcx>
6701 replace_late_bound_regions(tcx, value, |_| ty::ReStatic).0
6704 /// Rewrite any late-bound regions so that they are anonymous. Region numbers are
6705 /// assigned starting at 1 and increasing monotonically in the order traversed
6706 /// by the fold operation.
6708 /// The chief purpose of this function is to canonicalize regions so that two
6709 /// `FnSig`s or `TraitRef`s which are equivalent up to region naming will become
6710 /// structurally identical. For example, `for<'a, 'b> fn(&'a int, &'b int)` and
6711 /// `for<'a, 'b> fn(&'b int, &'a int)` will become identical after anonymization.
6712 pub fn anonymize_late_bound_regions<'tcx, T>(
6716 where T : TypeFoldable<'tcx> + Repr<'tcx>,
6718 let mut counter = 0;
6719 ty::Binder(replace_late_bound_regions(tcx, sig, |_| {
6721 ReLateBound(ty::DebruijnIndex::new(1), BrAnon(counter))
6725 /// Replaces the late-bound-regions in `value` that are bound by `value`.
6726 pub fn replace_late_bound_regions<'tcx, T, F>(
6727 tcx: &ty::ctxt<'tcx>,
6730 -> (T, FnvHashMap<ty::BoundRegion,ty::Region>)
6731 where T : TypeFoldable<'tcx> + Repr<'tcx>,
6732 F : FnMut(BoundRegion) -> ty::Region,
6734 debug!("replace_late_bound_regions({})", binder.repr(tcx));
6736 let mut map = FnvHashMap();
6738 // Note: fold the field `0`, not the binder, so that late-bound
6739 // regions bound by `binder` are considered free.
6740 let value = ty_fold::fold_regions(tcx, &binder.0, |region, current_depth| {
6741 debug!("region={}", region.repr(tcx));
6743 ty::ReLateBound(debruijn, br) if debruijn.depth == current_depth => {
6745 * map.entry(br).get().unwrap_or_else(
6746 |vacant_entry| vacant_entry.insert(mapf(br)));
6748 if let ty::ReLateBound(debruijn1, br) = region {
6749 // If the callback returns a late-bound region,
6750 // that region should always use depth 1. Then we
6751 // adjust it to the correct depth.
6752 assert_eq!(debruijn1.depth, 1);
6753 ty::ReLateBound(debruijn, br)
6764 debug!("resulting map: {:?} value: {:?}", map, value.repr(tcx));
6768 impl DebruijnIndex {
6769 pub fn new(depth: u32) -> DebruijnIndex {
6771 DebruijnIndex { depth: depth }
6774 pub fn shifted(&self, amount: u32) -> DebruijnIndex {
6775 DebruijnIndex { depth: self.depth + amount }
6779 impl<'tcx> Repr<'tcx> for AutoAdjustment<'tcx> {
6780 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6782 AdjustReifyFnPointer(def_id) => {
6783 format!("AdjustReifyFnPointer({})", def_id.repr(tcx))
6785 AdjustDerefRef(ref data) => {
6792 impl<'tcx> Repr<'tcx> for UnsizeKind<'tcx> {
6793 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6795 UnsizeLength(n) => format!("UnsizeLength({})", n),
6796 UnsizeStruct(ref k, n) => format!("UnsizeStruct({},{})", k.repr(tcx), n),
6797 UnsizeVtable(ref a, ref b) => format!("UnsizeVtable({},{})", a.repr(tcx), b.repr(tcx)),
6802 impl<'tcx> Repr<'tcx> for AutoDerefRef<'tcx> {
6803 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6804 format!("AutoDerefRef({}, {})", self.autoderefs, self.autoref.repr(tcx))
6808 impl<'tcx> Repr<'tcx> for AutoRef<'tcx> {
6809 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6811 AutoPtr(a, b, ref c) => {
6812 format!("AutoPtr({},{:?},{})", a.repr(tcx), b, c.repr(tcx))
6814 AutoUnsize(ref a) => {
6815 format!("AutoUnsize({})", a.repr(tcx))
6817 AutoUnsizeUniq(ref a) => {
6818 format!("AutoUnsizeUniq({})", a.repr(tcx))
6820 AutoUnsafe(ref a, ref b) => {
6821 format!("AutoUnsafe({:?},{})", a, b.repr(tcx))
6827 impl<'tcx> Repr<'tcx> for TyTrait<'tcx> {
6828 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6829 format!("TyTrait({},{})",
6830 self.principal.repr(tcx),
6831 self.bounds.repr(tcx))
6835 impl<'tcx> Repr<'tcx> for ty::Predicate<'tcx> {
6836 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6838 Predicate::Trait(ref a) => a.repr(tcx),
6839 Predicate::Equate(ref pair) => pair.repr(tcx),
6840 Predicate::RegionOutlives(ref pair) => pair.repr(tcx),
6841 Predicate::TypeOutlives(ref pair) => pair.repr(tcx),
6842 Predicate::Projection(ref pair) => pair.repr(tcx),
6847 impl<'tcx> Repr<'tcx> for vtable_origin<'tcx> {
6848 fn repr(&self, tcx: &ty::ctxt<'tcx>) -> String {
6850 vtable_static(def_id, ref tys, ref vtable_res) => {
6851 format!("vtable_static({:?}:{}, {}, {})",
6853 ty::item_path_str(tcx, def_id),
6855 vtable_res.repr(tcx))
6858 vtable_param(x, y) => {
6859 format!("vtable_param({:?}, {})", x, y)
6862 vtable_closure(def_id) => {
6863 format!("vtable_closure({:?})", def_id)
6867 format!("vtable_error")
6873 pub fn make_substs_for_receiver_types<'tcx>(tcx: &ty::ctxt<'tcx>,
6874 trait_ref: &ty::TraitRef<'tcx>,
6875 method: &ty::Method<'tcx>)
6876 -> subst::Substs<'tcx>
6879 * Substitutes the values for the receiver's type parameters
6880 * that are found in method, leaving the method's type parameters
6884 let meth_tps: Vec<Ty> =
6885 method.generics.types.get_slice(subst::FnSpace)
6887 .map(|def| ty::mk_param_from_def(tcx, def))
6889 let meth_regions: Vec<ty::Region> =
6890 method.generics.regions.get_slice(subst::FnSpace)
6892 .map(|def| ty::ReEarlyBound(def.def_id.node, def.space,
6893 def.index, def.name))
6895 trait_ref.substs.clone().with_method(meth_tps, meth_regions)
6899 pub enum CopyImplementationError {
6900 FieldDoesNotImplementCopy(ast::Name),
6901 VariantDoesNotImplementCopy(ast::Name),
6906 pub fn can_type_implement_copy<'a,'tcx>(param_env: &ParameterEnvironment<'a, 'tcx>,
6908 self_type: Ty<'tcx>)
6909 -> Result<(),CopyImplementationError>
6911 let tcx = param_env.tcx;
6913 let did = match self_type.sty {
6914 ty::ty_struct(struct_did, substs) => {
6915 let fields = ty::struct_fields(tcx, struct_did, substs);
6916 for field in &fields {
6917 if type_moves_by_default(param_env, span, field.mt.ty) {
6918 return Err(FieldDoesNotImplementCopy(field.name))
6923 ty::ty_enum(enum_did, substs) => {
6924 let enum_variants = ty::enum_variants(tcx, enum_did);
6925 for variant in &*enum_variants {
6926 for variant_arg_type in &variant.args {
6927 let substd_arg_type =
6928 variant_arg_type.subst(tcx, substs);
6929 if type_moves_by_default(param_env, span, substd_arg_type) {
6930 return Err(VariantDoesNotImplementCopy(variant.name))
6936 _ => return Err(TypeIsStructural),
6939 if ty::has_dtor(tcx, did) {
6940 return Err(TypeHasDestructor)
6946 // FIXME(#20298) -- all of these types basically walk various
6947 // structures to test whether types/regions are reachable with various
6948 // properties. It should be possible to express them in terms of one
6949 // common "walker" trait or something.
6951 pub trait RegionEscape {
6952 fn has_escaping_regions(&self) -> bool {
6953 self.has_regions_escaping_depth(0)
6956 fn has_regions_escaping_depth(&self, depth: u32) -> bool;
6959 impl<'tcx> RegionEscape for Ty<'tcx> {
6960 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6961 ty::type_escapes_depth(*self, depth)
6965 impl<'tcx> RegionEscape for Substs<'tcx> {
6966 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6967 self.types.has_regions_escaping_depth(depth) ||
6968 self.regions.has_regions_escaping_depth(depth)
6972 impl<'tcx,T:RegionEscape> RegionEscape for VecPerParamSpace<T> {
6973 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6974 self.iter_enumerated().any(|(space, _, t)| {
6975 if space == subst::FnSpace {
6976 t.has_regions_escaping_depth(depth+1)
6978 t.has_regions_escaping_depth(depth)
6984 impl<'tcx> RegionEscape for TypeScheme<'tcx> {
6985 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6986 self.ty.has_regions_escaping_depth(depth)
6990 impl RegionEscape for Region {
6991 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6992 self.escapes_depth(depth)
6996 impl<'tcx> RegionEscape for GenericPredicates<'tcx> {
6997 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6998 self.predicates.has_regions_escaping_depth(depth)
7002 impl<'tcx> RegionEscape for Predicate<'tcx> {
7003 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7005 Predicate::Trait(ref data) => data.has_regions_escaping_depth(depth),
7006 Predicate::Equate(ref data) => data.has_regions_escaping_depth(depth),
7007 Predicate::RegionOutlives(ref data) => data.has_regions_escaping_depth(depth),
7008 Predicate::TypeOutlives(ref data) => data.has_regions_escaping_depth(depth),
7009 Predicate::Projection(ref data) => data.has_regions_escaping_depth(depth),
7014 impl<'tcx> RegionEscape for TraitRef<'tcx> {
7015 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7016 self.substs.types.iter().any(|t| t.has_regions_escaping_depth(depth)) ||
7017 self.substs.regions.has_regions_escaping_depth(depth)
7021 impl<'tcx> RegionEscape for subst::RegionSubsts {
7022 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7024 subst::ErasedRegions => false,
7025 subst::NonerasedRegions(ref r) => {
7026 r.iter().any(|t| t.has_regions_escaping_depth(depth))
7032 impl<'tcx,T:RegionEscape> RegionEscape for Binder<T> {
7033 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7034 self.0.has_regions_escaping_depth(depth + 1)
7038 impl<'tcx> RegionEscape for EquatePredicate<'tcx> {
7039 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7040 self.0.has_regions_escaping_depth(depth) || self.1.has_regions_escaping_depth(depth)
7044 impl<'tcx> RegionEscape for TraitPredicate<'tcx> {
7045 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7046 self.trait_ref.has_regions_escaping_depth(depth)
7050 impl<T:RegionEscape,U:RegionEscape> RegionEscape for OutlivesPredicate<T,U> {
7051 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7052 self.0.has_regions_escaping_depth(depth) || self.1.has_regions_escaping_depth(depth)
7056 impl<'tcx> RegionEscape for ProjectionPredicate<'tcx> {
7057 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7058 self.projection_ty.has_regions_escaping_depth(depth) ||
7059 self.ty.has_regions_escaping_depth(depth)
7063 impl<'tcx> RegionEscape for ProjectionTy<'tcx> {
7064 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7065 self.trait_ref.has_regions_escaping_depth(depth)
7069 impl<'tcx> Repr<'tcx> for ty::ProjectionPredicate<'tcx> {
7070 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7071 format!("ProjectionPredicate({}, {})",
7072 self.projection_ty.repr(tcx),
7077 pub trait HasProjectionTypes {
7078 fn has_projection_types(&self) -> bool;
7081 impl<'tcx,T:HasProjectionTypes> HasProjectionTypes for Vec<T> {
7082 fn has_projection_types(&self) -> bool {
7083 self.iter().any(|p| p.has_projection_types())
7087 impl<'tcx,T:HasProjectionTypes> HasProjectionTypes for VecPerParamSpace<T> {
7088 fn has_projection_types(&self) -> bool {
7089 self.iter().any(|p| p.has_projection_types())
7093 impl<'tcx> HasProjectionTypes for ClosureTy<'tcx> {
7094 fn has_projection_types(&self) -> bool {
7095 self.sig.has_projection_types()
7099 impl<'tcx> HasProjectionTypes for ClosureUpvar<'tcx> {
7100 fn has_projection_types(&self) -> bool {
7101 self.ty.has_projection_types()
7105 impl<'tcx> HasProjectionTypes for ty::InstantiatedPredicates<'tcx> {
7106 fn has_projection_types(&self) -> bool {
7107 self.predicates.has_projection_types()
7111 impl<'tcx> HasProjectionTypes for Predicate<'tcx> {
7112 fn has_projection_types(&self) -> bool {
7114 Predicate::Trait(ref data) => data.has_projection_types(),
7115 Predicate::Equate(ref data) => data.has_projection_types(),
7116 Predicate::RegionOutlives(ref data) => data.has_projection_types(),
7117 Predicate::TypeOutlives(ref data) => data.has_projection_types(),
7118 Predicate::Projection(ref data) => data.has_projection_types(),
7123 impl<'tcx> HasProjectionTypes for TraitPredicate<'tcx> {
7124 fn has_projection_types(&self) -> bool {
7125 self.trait_ref.has_projection_types()
7129 impl<'tcx> HasProjectionTypes for EquatePredicate<'tcx> {
7130 fn has_projection_types(&self) -> bool {
7131 self.0.has_projection_types() || self.1.has_projection_types()
7135 impl HasProjectionTypes for Region {
7136 fn has_projection_types(&self) -> bool {
7141 impl<T:HasProjectionTypes,U:HasProjectionTypes> HasProjectionTypes for OutlivesPredicate<T,U> {
7142 fn has_projection_types(&self) -> bool {
7143 self.0.has_projection_types() || self.1.has_projection_types()
7147 impl<'tcx> HasProjectionTypes for ProjectionPredicate<'tcx> {
7148 fn has_projection_types(&self) -> bool {
7149 self.projection_ty.has_projection_types() || self.ty.has_projection_types()
7153 impl<'tcx> HasProjectionTypes for ProjectionTy<'tcx> {
7154 fn has_projection_types(&self) -> bool {
7155 self.trait_ref.has_projection_types()
7159 impl<'tcx> HasProjectionTypes for Ty<'tcx> {
7160 fn has_projection_types(&self) -> bool {
7161 ty::type_has_projection(*self)
7165 impl<'tcx> HasProjectionTypes for TraitRef<'tcx> {
7166 fn has_projection_types(&self) -> bool {
7167 self.substs.has_projection_types()
7171 impl<'tcx> HasProjectionTypes for subst::Substs<'tcx> {
7172 fn has_projection_types(&self) -> bool {
7173 self.types.iter().any(|t| t.has_projection_types())
7177 impl<'tcx,T> HasProjectionTypes for Option<T>
7178 where T : HasProjectionTypes
7180 fn has_projection_types(&self) -> bool {
7181 self.iter().any(|t| t.has_projection_types())
7185 impl<'tcx,T> HasProjectionTypes for Rc<T>
7186 where T : HasProjectionTypes
7188 fn has_projection_types(&self) -> bool {
7189 (**self).has_projection_types()
7193 impl<'tcx,T> HasProjectionTypes for Box<T>
7194 where T : HasProjectionTypes
7196 fn has_projection_types(&self) -> bool {
7197 (**self).has_projection_types()
7201 impl<T> HasProjectionTypes for Binder<T>
7202 where T : HasProjectionTypes
7204 fn has_projection_types(&self) -> bool {
7205 self.0.has_projection_types()
7209 impl<'tcx> HasProjectionTypes for FnOutput<'tcx> {
7210 fn has_projection_types(&self) -> bool {
7212 FnConverging(t) => t.has_projection_types(),
7213 FnDiverging => false,
7218 impl<'tcx> HasProjectionTypes for FnSig<'tcx> {
7219 fn has_projection_types(&self) -> bool {
7220 self.inputs.iter().any(|t| t.has_projection_types()) ||
7221 self.output.has_projection_types()
7225 impl<'tcx> HasProjectionTypes for field<'tcx> {
7226 fn has_projection_types(&self) -> bool {
7227 self.mt.ty.has_projection_types()
7231 impl<'tcx> HasProjectionTypes for BareFnTy<'tcx> {
7232 fn has_projection_types(&self) -> bool {
7233 self.sig.has_projection_types()
7237 pub trait ReferencesError {
7238 fn references_error(&self) -> bool;
7241 impl<T:ReferencesError> ReferencesError for Binder<T> {
7242 fn references_error(&self) -> bool {
7243 self.0.references_error()
7247 impl<T:ReferencesError> ReferencesError for Rc<T> {
7248 fn references_error(&self) -> bool {
7249 (&**self).references_error()
7253 impl<'tcx> ReferencesError for TraitPredicate<'tcx> {
7254 fn references_error(&self) -> bool {
7255 self.trait_ref.references_error()
7259 impl<'tcx> ReferencesError for ProjectionPredicate<'tcx> {
7260 fn references_error(&self) -> bool {
7261 self.projection_ty.trait_ref.references_error() || self.ty.references_error()
7265 impl<'tcx> ReferencesError for TraitRef<'tcx> {
7266 fn references_error(&self) -> bool {
7267 self.input_types().iter().any(|t| t.references_error())
7271 impl<'tcx> ReferencesError for Ty<'tcx> {
7272 fn references_error(&self) -> bool {
7273 type_is_error(*self)
7277 impl<'tcx> ReferencesError for Predicate<'tcx> {
7278 fn references_error(&self) -> bool {
7280 Predicate::Trait(ref data) => data.references_error(),
7281 Predicate::Equate(ref data) => data.references_error(),
7282 Predicate::RegionOutlives(ref data) => data.references_error(),
7283 Predicate::TypeOutlives(ref data) => data.references_error(),
7284 Predicate::Projection(ref data) => data.references_error(),
7289 impl<A,B> ReferencesError for OutlivesPredicate<A,B>
7290 where A : ReferencesError, B : ReferencesError
7292 fn references_error(&self) -> bool {
7293 self.0.references_error() || self.1.references_error()
7297 impl<'tcx> ReferencesError for EquatePredicate<'tcx>
7299 fn references_error(&self) -> bool {
7300 self.0.references_error() || self.1.references_error()
7304 impl ReferencesError for Region
7306 fn references_error(&self) -> bool {
7311 impl<'tcx> Repr<'tcx> for ClosureTy<'tcx> {
7312 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7313 format!("ClosureTy({},{},{})",
7320 impl<'tcx> Repr<'tcx> for ClosureUpvar<'tcx> {
7321 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7322 format!("ClosureUpvar({},{})",
7328 impl<'tcx> Repr<'tcx> for field<'tcx> {
7329 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7330 format!("field({},{})",
7331 self.name.repr(tcx),
7336 impl<'a, 'tcx> Repr<'tcx> for ParameterEnvironment<'a, 'tcx> {
7337 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7338 format!("ParameterEnvironment(\
7340 implicit_region_bound={}, \
7342 self.free_substs.repr(tcx),
7343 self.implicit_region_bound.repr(tcx),
7344 self.caller_bounds.repr(tcx))
7348 impl<'tcx> Repr<'tcx> for ObjectLifetimeDefault {
7349 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7351 ObjectLifetimeDefault::Ambiguous => format!("Ambiguous"),
7352 ObjectLifetimeDefault::Specific(ref r) => r.repr(tcx),