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::UnboxedClosureKind::*;
20 pub use self::TraitStore::*;
21 pub use self::ast_ty_to_ty_cache_entry::*;
22 pub use self::Variance::*;
23 pub use self::AutoAdjustment::*;
24 pub use self::Representability::*;
25 pub use self::UnsizeKind::*;
26 pub use self::AutoRef::*;
27 pub use self::ExprKind::*;
28 pub use self::DtorKind::*;
29 pub use self::ExplicitSelfCategory::*;
30 pub use self::FnOutput::*;
31 pub use self::Region::*;
32 pub use self::ImplOrTraitItemContainer::*;
33 pub use self::BorrowKind::*;
34 pub use self::ImplOrTraitItem::*;
35 pub use self::BoundRegion::*;
37 pub use self::IntVarValue::*;
38 pub use self::ExprAdjustment::*;
39 pub use self::vtable_origin::*;
40 pub use self::MethodOrigin::*;
41 pub use self::CopyImplementationError::*;
46 use metadata::csearch;
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::{trait_store_to_string, 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};
73 use std::cmp::{self, Ordering};
74 use std::fmt::{self, Show};
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::{Onceness, StmtExpr, StmtSemi, StructField, UnnamedField};
86 use syntax::ast::{Visibility};
87 use syntax::ast_util::{self, is_local, lit_is_str, local_def, PostExpansionMethod};
88 use syntax::attr::{self, AttrMetaMethods};
89 use syntax::codemap::Span;
90 use syntax::parse::token::{self, InternedString, special_idents};
91 use syntax::{ast, ast_map};
95 pub const INITIAL_DISCRIMINANT_VALUE: Disr = 0;
99 /// The complete set of all analyses described in this module. This is
100 /// produced by the driver and fed to trans and later passes.
101 pub struct CrateAnalysis<'tcx> {
102 pub export_map: ExportMap,
103 pub exported_items: middle::privacy::ExportedItems,
104 pub public_items: middle::privacy::PublicItems,
105 pub ty_cx: ty::ctxt<'tcx>,
106 pub reachable: NodeSet,
108 pub glob_map: Option<GlobMap>,
111 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
112 pub struct field<'tcx> {
117 #[derive(Clone, Copy, Show)]
118 pub enum ImplOrTraitItemContainer {
119 TraitContainer(ast::DefId),
120 ImplContainer(ast::DefId),
123 impl ImplOrTraitItemContainer {
124 pub fn id(&self) -> ast::DefId {
126 TraitContainer(id) => id,
127 ImplContainer(id) => id,
132 #[derive(Clone, Show)]
133 pub enum ImplOrTraitItem<'tcx> {
134 MethodTraitItem(Rc<Method<'tcx>>),
135 TypeTraitItem(Rc<AssociatedType>),
138 impl<'tcx> ImplOrTraitItem<'tcx> {
139 fn id(&self) -> ImplOrTraitItemId {
141 MethodTraitItem(ref method) => MethodTraitItemId(method.def_id),
142 TypeTraitItem(ref associated_type) => {
143 TypeTraitItemId(associated_type.def_id)
148 pub fn def_id(&self) -> ast::DefId {
150 MethodTraitItem(ref method) => method.def_id,
151 TypeTraitItem(ref associated_type) => associated_type.def_id,
155 pub fn name(&self) -> ast::Name {
157 MethodTraitItem(ref method) => method.name,
158 TypeTraitItem(ref associated_type) => associated_type.name,
162 pub fn container(&self) -> ImplOrTraitItemContainer {
164 MethodTraitItem(ref method) => method.container,
165 TypeTraitItem(ref associated_type) => associated_type.container,
169 pub fn as_opt_method(&self) -> Option<Rc<Method<'tcx>>> {
171 MethodTraitItem(ref m) => Some((*m).clone()),
172 TypeTraitItem(_) => None
177 #[derive(Clone, Copy, Show)]
178 pub enum ImplOrTraitItemId {
179 MethodTraitItemId(ast::DefId),
180 TypeTraitItemId(ast::DefId),
183 impl ImplOrTraitItemId {
184 pub fn def_id(&self) -> ast::DefId {
186 MethodTraitItemId(def_id) => def_id,
187 TypeTraitItemId(def_id) => def_id,
192 #[derive(Clone, Show)]
193 pub struct Method<'tcx> {
195 pub generics: ty::Generics<'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>,
210 explicit_self: ExplicitSelfCategory,
211 vis: ast::Visibility,
213 container: ImplOrTraitItemContainer,
214 provided_source: Option<ast::DefId>)
220 explicit_self: explicit_self,
223 container: container,
224 provided_source: provided_source
228 pub fn container_id(&self) -> ast::DefId {
229 match self.container {
230 TraitContainer(id) => id,
231 ImplContainer(id) => id,
236 #[derive(Clone, Copy, Show)]
237 pub struct AssociatedType {
239 pub vis: ast::Visibility,
240 pub def_id: ast::DefId,
241 pub container: ImplOrTraitItemContainer,
244 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
245 pub struct mt<'tcx> {
247 pub mutbl: ast::Mutability,
250 #[derive(Clone, Copy, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Show)]
251 pub enum TraitStore {
254 /// &Trait and &mut Trait
255 RegionTraitStore(Region, ast::Mutability),
258 #[derive(Clone, Copy, Show)]
259 pub struct field_ty {
262 pub vis: ast::Visibility,
263 pub origin: ast::DefId, // The DefId of the struct in which the field is declared.
266 // Contains information needed to resolve types and (in the future) look up
267 // the types of AST nodes.
268 #[derive(Copy, PartialEq, Eq, Hash)]
269 pub struct creader_cache_key {
276 pub enum ast_ty_to_ty_cache_entry<'tcx> {
277 atttce_unresolved, /* not resolved yet */
278 atttce_resolved(Ty<'tcx>) /* resolved to a type, irrespective of region */
281 #[derive(Clone, PartialEq, RustcDecodable, RustcEncodable)]
282 pub struct ItemVariances {
283 pub types: VecPerParamSpace<Variance>,
284 pub regions: VecPerParamSpace<Variance>,
287 #[derive(Clone, PartialEq, RustcDecodable, RustcEncodable, Show, Copy)]
289 Covariant, // T<A> <: T<B> iff A <: B -- e.g., function return type
290 Invariant, // T<A> <: T<B> iff B == A -- e.g., type of mutable cell
291 Contravariant, // T<A> <: T<B> iff B <: A -- e.g., function param type
292 Bivariant, // T<A> <: T<B> -- e.g., unused type parameter
295 #[derive(Clone, Show)]
296 pub enum AutoAdjustment<'tcx> {
297 AdjustReifyFnPointer(ast::DefId), // go from a fn-item type to a fn-pointer type
298 AdjustDerefRef(AutoDerefRef<'tcx>)
301 #[derive(Clone, PartialEq, Show)]
302 pub enum UnsizeKind<'tcx> {
303 // [T, ..n] -> [T], the uint field is n.
305 // An unsize coercion applied to the tail field of a struct.
306 // The uint is the index of the type parameter which is unsized.
307 UnsizeStruct(Box<UnsizeKind<'tcx>>, uint),
308 UnsizeVtable(TyTrait<'tcx>, /* the self type of the trait */ Ty<'tcx>)
311 #[derive(Clone, Show)]
312 pub struct AutoDerefRef<'tcx> {
313 pub autoderefs: uint,
314 pub autoref: Option<AutoRef<'tcx>>
317 #[derive(Clone, PartialEq, Show)]
318 pub enum AutoRef<'tcx> {
319 /// Convert from T to &T
320 /// The third field allows us to wrap other AutoRef adjustments.
321 AutoPtr(Region, ast::Mutability, Option<Box<AutoRef<'tcx>>>),
323 /// Convert [T, ..n] to [T] (or similar, depending on the kind)
324 AutoUnsize(UnsizeKind<'tcx>),
326 /// Convert Box<[T, ..n]> to Box<[T]> or something similar in a Box.
327 /// With DST and Box a library type, this should be replaced by UnsizeStruct.
328 AutoUnsizeUniq(UnsizeKind<'tcx>),
330 /// Convert from T to *T
331 /// Value to thin pointer
332 /// The second field allows us to wrap other AutoRef adjustments.
333 AutoUnsafe(ast::Mutability, Option<Box<AutoRef<'tcx>>>),
336 // Ugly little helper function. The first bool in the returned tuple is true if
337 // there is an 'unsize to trait object' adjustment at the bottom of the
338 // adjustment. If that is surrounded by an AutoPtr, then we also return the
339 // region of the AutoPtr (in the third argument). The second bool is true if the
340 // adjustment is unique.
341 fn autoref_object_region(autoref: &AutoRef) -> (bool, bool, Option<Region>) {
342 fn unsize_kind_is_object(k: &UnsizeKind) -> bool {
344 &UnsizeVtable(..) => true,
345 &UnsizeStruct(box ref k, _) => unsize_kind_is_object(k),
351 &AutoUnsize(ref k) => (unsize_kind_is_object(k), false, None),
352 &AutoUnsizeUniq(ref k) => (unsize_kind_is_object(k), true, None),
353 &AutoPtr(adj_r, _, Some(box ref autoref)) => {
354 let (b, u, r) = autoref_object_region(autoref);
355 if r.is_some() || u {
361 &AutoUnsafe(_, Some(box ref autoref)) => autoref_object_region(autoref),
362 _ => (false, false, None)
366 // If the adjustment introduces a borrowed reference to a trait object, then
367 // returns the region of the borrowed reference.
368 pub fn adjusted_object_region(adj: &AutoAdjustment) -> Option<Region> {
370 &AdjustDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
371 let (b, _, r) = autoref_object_region(autoref);
382 // Returns true if there is a trait cast at the bottom of the adjustment.
383 pub fn adjust_is_object(adj: &AutoAdjustment) -> bool {
385 &AdjustDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
386 let (b, _, _) = autoref_object_region(autoref);
393 // If possible, returns the type expected from the given adjustment. This is not
394 // possible if the adjustment depends on the type of the adjusted expression.
395 pub fn type_of_adjust<'tcx>(cx: &ctxt<'tcx>, adj: &AutoAdjustment<'tcx>) -> Option<Ty<'tcx>> {
396 fn type_of_autoref<'tcx>(cx: &ctxt<'tcx>, autoref: &AutoRef<'tcx>) -> Option<Ty<'tcx>> {
398 &AutoUnsize(ref k) => match k {
399 &UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
400 Some(mk_trait(cx, principal.clone(), bounds.clone()))
404 &AutoUnsizeUniq(ref k) => match k {
405 &UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
406 Some(mk_uniq(cx, mk_trait(cx, principal.clone(), bounds.clone())))
410 &AutoPtr(r, m, Some(box ref autoref)) => {
411 match type_of_autoref(cx, autoref) {
412 Some(ty) => Some(mk_rptr(cx, cx.mk_region(r), mt {mutbl: m, ty: ty})),
416 &AutoUnsafe(m, Some(box ref autoref)) => {
417 match type_of_autoref(cx, autoref) {
418 Some(ty) => Some(mk_ptr(cx, mt {mutbl: m, ty: ty})),
427 &AdjustDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
428 type_of_autoref(cx, autoref)
434 #[derive(Clone, Copy, RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Show)]
435 pub struct param_index {
436 pub space: subst::ParamSpace,
440 #[derive(Clone, Show)]
441 pub enum MethodOrigin<'tcx> {
442 // fully statically resolved method
443 MethodStatic(ast::DefId),
445 // fully statically resolved unboxed closure invocation
446 MethodStaticUnboxedClosure(ast::DefId),
448 // method invoked on a type parameter with a bounded trait
449 MethodTypeParam(MethodParam<'tcx>),
451 // method invoked on a trait instance
452 MethodTraitObject(MethodObject<'tcx>),
456 // details for a method invoked with a receiver whose type is a type parameter
457 // with a bounded trait.
458 #[derive(Clone, Show)]
459 pub struct MethodParam<'tcx> {
460 // the precise trait reference that occurs as a bound -- this may
461 // be a supertrait of what the user actually typed. Note that it
462 // never contains bound regions; those regions should have been
463 // instantiated with fresh variables at this point.
464 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
466 // index of uint in the list of methods for the trait
467 pub method_num: uint,
470 // details for a method invoked with a receiver whose type is an object
471 #[derive(Clone, Show)]
472 pub struct MethodObject<'tcx> {
473 // the (super)trait containing the method to be invoked
474 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
476 // the actual base trait id of the object
477 pub object_trait_id: ast::DefId,
479 // index of the method to be invoked amongst the trait's methods
480 pub method_num: uint,
482 // index into the actual runtime vtable.
483 // the vtable is formed by concatenating together the method lists of
484 // the base object trait and all supertraits; this is the index into
486 pub real_index: uint,
490 pub struct MethodCallee<'tcx> {
491 pub origin: MethodOrigin<'tcx>,
493 pub substs: subst::Substs<'tcx>
496 /// With method calls, we store some extra information in
497 /// side tables (i.e method_map). We use
498 /// MethodCall as a key to index into these tables instead of
499 /// just directly using the expression's NodeId. The reason
500 /// for this being that we may apply adjustments (coercions)
501 /// with the resulting expression also needing to use the
502 /// side tables. The problem with this is that we don't
503 /// assign a separate NodeId to this new expression
504 /// and so it would clash with the base expression if both
505 /// needed to add to the side tables. Thus to disambiguate
506 /// we also keep track of whether there's an adjustment in
508 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
509 pub struct MethodCall {
510 pub expr_id: ast::NodeId,
511 pub adjustment: ExprAdjustment
514 #[derive(Clone, PartialEq, Eq, Hash, Show, RustcEncodable, RustcDecodable, Copy)]
515 pub enum ExprAdjustment {
522 pub fn expr(id: ast::NodeId) -> MethodCall {
525 adjustment: NoAdjustment
529 pub fn autoobject(id: ast::NodeId) -> MethodCall {
532 adjustment: AutoObject
536 pub fn autoderef(expr_id: ast::NodeId, autoderef: uint) -> MethodCall {
539 adjustment: AutoDeref(1 + autoderef)
544 // maps from an expression id that corresponds to a method call to the details
545 // of the method to be invoked
546 pub type MethodMap<'tcx> = RefCell<FnvHashMap<MethodCall, MethodCallee<'tcx>>>;
548 pub type vtable_param_res<'tcx> = Vec<vtable_origin<'tcx>>;
550 // Resolutions for bounds of all parameters, left to right, for a given path.
551 pub type vtable_res<'tcx> = VecPerParamSpace<vtable_param_res<'tcx>>;
554 pub enum vtable_origin<'tcx> {
556 Statically known vtable. def_id gives the impl item
557 from whence comes the vtable, and tys are the type substs.
558 vtable_res is the vtable itself.
560 vtable_static(ast::DefId, subst::Substs<'tcx>, vtable_res<'tcx>),
563 Dynamic vtable, comes from a parameter that has a bound on it:
564 fn foo<T:quux,baz,bar>(a: T) -- a's vtable would have a
567 The first argument is the param index (identifying T in the example),
568 and the second is the bound number (identifying baz)
570 vtable_param(param_index, uint),
573 Vtable automatically generated for an unboxed closure. The def ID is the
574 ID of the closure expression.
576 vtable_unboxed_closure(ast::DefId),
579 Asked to determine the vtable for ty_err. This is the value used
580 for the vtables of `Self` in a virtual call like `foo.bar()`
581 where `foo` is of object type. The same value is also used when
588 // For every explicit cast into an object type, maps from the cast
589 // expr to the associated trait ref.
590 pub type ObjectCastMap<'tcx> = RefCell<NodeMap<ty::PolyTraitRef<'tcx>>>;
592 /// A restriction that certain types must be the same size. The use of
593 /// `transmute` gives rise to these restrictions. These generally
594 /// cannot be checked until trans; therefore, each call to `transmute`
595 /// will push one or more such restriction into the
596 /// `transmute_restrictions` vector during `intrinsicck`. They are
597 /// then checked during `trans` by the fn `check_intrinsics`.
599 pub struct TransmuteRestriction<'tcx> {
600 /// The span whence the restriction comes.
603 /// The type being transmuted from.
604 pub original_from: Ty<'tcx>,
606 /// The type being transmuted to.
607 pub original_to: Ty<'tcx>,
609 /// The type being transmuted from, with all type parameters
610 /// substituted for an arbitrary representative. Not to be shown
612 pub substituted_from: Ty<'tcx>,
614 /// The type being transmuted to, with all type parameters
615 /// substituted for an arbitrary representative. Not to be shown
617 pub substituted_to: Ty<'tcx>,
619 /// NodeId of the transmute intrinsic.
624 pub struct CtxtArenas<'tcx> {
625 type_: TypedArena<TyS<'tcx>>,
626 substs: TypedArena<Substs<'tcx>>,
627 bare_fn: TypedArena<BareFnTy<'tcx>>,
628 region: TypedArena<Region>,
631 impl<'tcx> CtxtArenas<'tcx> {
632 pub fn new() -> CtxtArenas<'tcx> {
634 type_: TypedArena::new(),
635 substs: TypedArena::new(),
636 bare_fn: TypedArena::new(),
637 region: TypedArena::new(),
642 pub struct CommonTypes<'tcx> {
660 /// The data structure to keep track of all the information that typechecker
661 /// generates so that so that it can be reused and doesn't have to be redone
663 pub struct ctxt<'tcx> {
664 /// The arenas that types etc are allocated from.
665 arenas: &'tcx CtxtArenas<'tcx>,
667 /// Specifically use a speedy hash algorithm for this hash map, it's used
669 // FIXME(eddyb) use a FnvHashSet<InternedTy<'tcx>> when equivalent keys can
670 // queried from a HashSet.
671 interner: RefCell<FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>>,
673 // FIXME as above, use a hashset if equivalent elements can be queried.
674 substs_interner: RefCell<FnvHashMap<&'tcx Substs<'tcx>, &'tcx Substs<'tcx>>>,
675 bare_fn_interner: RefCell<FnvHashMap<&'tcx BareFnTy<'tcx>, &'tcx BareFnTy<'tcx>>>,
676 region_interner: RefCell<FnvHashMap<&'tcx Region, &'tcx Region>>,
678 /// Common types, pre-interned for your convenience.
679 pub types: CommonTypes<'tcx>,
684 pub named_region_map: resolve_lifetime::NamedRegionMap,
686 pub region_maps: middle::region::RegionMaps,
688 /// Stores the types for various nodes in the AST. Note that this table
689 /// is not guaranteed to be populated until after typeck. See
690 /// typeck::check::fn_ctxt for details.
691 pub node_types: RefCell<NodeMap<Ty<'tcx>>>,
693 /// Stores the type parameters which were substituted to obtain the type
694 /// of this node. This only applies to nodes that refer to entities
695 /// parameterized by type parameters, such as generic fns, types, or
697 pub item_substs: RefCell<NodeMap<ItemSubsts<'tcx>>>,
699 /// Maps from a trait item to the trait item "descriptor"
700 pub impl_or_trait_items: RefCell<DefIdMap<ImplOrTraitItem<'tcx>>>,
702 /// Maps from a trait def-id to a list of the def-ids of its trait items
703 pub trait_item_def_ids: RefCell<DefIdMap<Rc<Vec<ImplOrTraitItemId>>>>,
705 /// A cache for the trait_items() routine
706 pub trait_items_cache: RefCell<DefIdMap<Rc<Vec<ImplOrTraitItem<'tcx>>>>>,
708 pub impl_trait_cache: RefCell<DefIdMap<Option<Rc<ty::TraitRef<'tcx>>>>>,
710 pub trait_refs: RefCell<NodeMap<Rc<TraitRef<'tcx>>>>,
711 pub trait_defs: RefCell<DefIdMap<Rc<TraitDef<'tcx>>>>,
713 /// Maps from node-id of a trait object cast (like `foo as
714 /// Box<Trait>`) to the trait reference.
715 pub object_cast_map: ObjectCastMap<'tcx>,
717 pub map: ast_map::Map<'tcx>,
718 pub intrinsic_defs: RefCell<DefIdMap<Ty<'tcx>>>,
719 pub freevars: RefCell<FreevarMap>,
720 pub tcache: RefCell<DefIdMap<TypeScheme<'tcx>>>,
721 pub rcache: RefCell<FnvHashMap<creader_cache_key, Ty<'tcx>>>,
722 pub short_names_cache: RefCell<FnvHashMap<Ty<'tcx>, String>>,
723 pub tc_cache: RefCell<FnvHashMap<Ty<'tcx>, TypeContents>>,
724 pub ast_ty_to_ty_cache: RefCell<NodeMap<ast_ty_to_ty_cache_entry<'tcx>>>,
725 pub enum_var_cache: RefCell<DefIdMap<Rc<Vec<Rc<VariantInfo<'tcx>>>>>>,
726 pub ty_param_defs: RefCell<NodeMap<TypeParameterDef<'tcx>>>,
727 pub adjustments: RefCell<NodeMap<AutoAdjustment<'tcx>>>,
728 pub normalized_cache: RefCell<FnvHashMap<Ty<'tcx>, Ty<'tcx>>>,
729 pub lang_items: middle::lang_items::LanguageItems,
730 /// A mapping of fake provided method def_ids to the default implementation
731 pub provided_method_sources: RefCell<DefIdMap<ast::DefId>>,
732 pub struct_fields: RefCell<DefIdMap<Rc<Vec<field_ty>>>>,
734 /// Maps from def-id of a type or region parameter to its
735 /// (inferred) variance.
736 pub item_variance_map: RefCell<DefIdMap<Rc<ItemVariances>>>,
738 /// True if the variance has been computed yet; false otherwise.
739 pub variance_computed: Cell<bool>,
741 /// A mapping from the def ID of an enum or struct type to the def ID
742 /// of the method that implements its destructor. If the type is not
743 /// present in this map, it does not have a destructor. This map is
744 /// populated during the coherence phase of typechecking.
745 pub destructor_for_type: RefCell<DefIdMap<ast::DefId>>,
747 /// A method will be in this list if and only if it is a destructor.
748 pub destructors: RefCell<DefIdSet>,
750 /// Maps a trait onto a list of impls of that trait.
751 pub trait_impls: RefCell<DefIdMap<Rc<RefCell<Vec<ast::DefId>>>>>,
753 /// Maps a DefId of a type to a list of its inherent impls.
754 /// Contains implementations of methods that are inherent to a type.
755 /// Methods in these implementations don't need to be exported.
756 pub inherent_impls: RefCell<DefIdMap<Rc<Vec<ast::DefId>>>>,
758 /// Maps a DefId of an impl to a list of its items.
759 /// Note that this contains all of the impls that we know about,
760 /// including ones in other crates. It's not clear that this is the best
762 pub impl_items: RefCell<DefIdMap<Vec<ImplOrTraitItemId>>>,
764 /// Set of used unsafe nodes (functions or blocks). Unsafe nodes not
765 /// present in this set can be warned about.
766 pub used_unsafe: RefCell<NodeSet>,
768 /// Set of nodes which mark locals as mutable which end up getting used at
769 /// some point. Local variable definitions not in this set can be warned
771 pub used_mut_nodes: RefCell<NodeSet>,
773 /// The set of external nominal types whose implementations have been read.
774 /// This is used for lazy resolution of methods.
775 pub populated_external_types: RefCell<DefIdSet>,
777 /// The set of external traits whose implementations have been read. This
778 /// is used for lazy resolution of traits.
779 pub populated_external_traits: RefCell<DefIdSet>,
782 pub upvar_borrow_map: RefCell<UpvarBorrowMap>,
784 /// These two caches are used by const_eval when decoding external statics
785 /// and variants that are found.
786 pub extern_const_statics: RefCell<DefIdMap<ast::NodeId>>,
787 pub extern_const_variants: RefCell<DefIdMap<ast::NodeId>>,
789 pub method_map: MethodMap<'tcx>,
791 pub dependency_formats: RefCell<dependency_format::Dependencies>,
793 /// Records the type of each unboxed closure. The def ID is the ID of the
794 /// expression defining the unboxed closure.
795 pub unboxed_closures: RefCell<DefIdMap<UnboxedClosure<'tcx>>>,
797 pub node_lint_levels: RefCell<FnvHashMap<(ast::NodeId, lint::LintId),
800 /// The types that must be asserted to be the same size for `transmute`
801 /// to be valid. We gather up these restrictions in the intrinsicck pass
802 /// and check them in trans.
803 pub transmute_restrictions: RefCell<Vec<TransmuteRestriction<'tcx>>>,
805 /// Maps any item's def-id to its stability index.
806 pub stability: RefCell<stability::Index>,
808 /// Maps closures to their capture clauses.
809 pub capture_modes: RefCell<CaptureModeMap>,
811 /// Maps def IDs to true if and only if they're associated types.
812 pub associated_types: RefCell<DefIdMap<bool>>,
814 /// Caches the results of trait selection. This cache is used
815 /// for things that do not have to do with the parameters in scope.
816 pub selection_cache: traits::SelectionCache<'tcx>,
818 /// Caches the representation hints for struct definitions.
819 pub repr_hint_cache: RefCell<DefIdMap<Rc<Vec<attr::ReprAttr>>>>,
821 /// Caches whether types are known to impl Copy. Note that type
822 /// parameters are never placed into this cache, because their
823 /// results are dependent on the parameter environment.
824 pub type_impls_copy_cache: RefCell<HashMap<Ty<'tcx>,bool>>,
826 /// Caches whether types are known to impl Sized. Note that type
827 /// parameters are never placed into this cache, because their
828 /// results are dependent on the parameter environment.
829 pub type_impls_sized_cache: RefCell<HashMap<Ty<'tcx>,bool>>,
831 /// Caches whether traits are object safe
832 pub object_safety_cache: RefCell<DefIdMap<bool>>,
835 // Flags that we track on types. These flags are propagated upwards
836 // through the type during type construction, so that we can quickly
837 // check whether the type has various kinds of types in it without
838 // recursing over the type itself.
840 flags TypeFlags: u32 {
841 const NO_TYPE_FLAGS = 0b0,
842 const HAS_PARAMS = 0b1,
843 const HAS_SELF = 0b10,
844 const HAS_TY_INFER = 0b100,
845 const HAS_RE_INFER = 0b1000,
846 const HAS_RE_LATE_BOUND = 0b10000,
847 const HAS_REGIONS = 0b100000,
848 const HAS_TY_ERR = 0b1000000,
849 const HAS_PROJECTION = 0b10000000,
850 const NEEDS_SUBST = HAS_PARAMS.bits | HAS_SELF.bits | HAS_REGIONS.bits,
854 macro_rules! sty_debug_print {
855 ($ctxt: expr, $($variant: ident),*) => {{
856 // curious inner module to allow variant names to be used as
868 pub fn go(tcx: &ty::ctxt) {
869 let mut total = DebugStat {
871 region_infer: 0, ty_infer: 0, both_infer: 0,
873 $(let mut $variant = total;)*
876 for (_, t) in tcx.interner.borrow().iter() {
877 let variant = match t.sty {
878 ty::ty_bool | ty::ty_char | ty::ty_int(..) | ty::ty_uint(..) |
879 ty::ty_float(..) | ty::ty_str => continue,
880 ty::ty_err => /* unimportant */ continue,
881 $(ty::$variant(..) => &mut $variant,)*
883 let region = t.flags.intersects(ty::HAS_RE_INFER);
884 let ty = t.flags.intersects(ty::HAS_TY_INFER);
888 if region { total.region_infer += 1; variant.region_infer += 1 }
889 if ty { total.ty_infer += 1; variant.ty_infer += 1 }
890 if region && ty { total.both_infer += 1; variant.both_infer += 1 }
892 println!("Ty interner total ty region both");
893 $(println!(" {:18}: {uses:6} {usespc:4.1}%, \
894 {ty:4.1}% {region:5.1}% {both:4.1}%",
895 stringify!($variant),
896 uses = $variant.total,
897 usespc = $variant.total as f64 * 100.0 / total.total as f64,
898 ty = $variant.ty_infer as f64 * 100.0 / total.total as f64,
899 region = $variant.region_infer as f64 * 100.0 / total.total as f64,
900 both = $variant.both_infer as f64 * 100.0 / total.total as f64);
902 println!(" total {uses:6} \
903 {ty:4.1}% {region:5.1}% {both:4.1}%",
905 ty = total.ty_infer as f64 * 100.0 / total.total as f64,
906 region = total.region_infer as f64 * 100.0 / total.total as f64,
907 both = total.both_infer as f64 * 100.0 / total.total as f64)
915 impl<'tcx> ctxt<'tcx> {
916 pub fn print_debug_stats(&self) {
919 ty_enum, ty_uniq, ty_vec, ty_ptr, ty_rptr, ty_bare_fn, ty_trait,
920 ty_struct, ty_unboxed_closure, ty_tup, ty_param, ty_open, ty_infer, ty_projection);
922 println!("Substs interner: #{}", self.substs_interner.borrow().len());
923 println!("BareFnTy interner: #{}", self.bare_fn_interner.borrow().len());
924 println!("Region interner: #{}", self.region_interner.borrow().len());
929 pub struct TyS<'tcx> {
931 pub flags: TypeFlags,
933 // the maximal depth of any bound regions appearing in this type.
937 impl fmt::Show for TypeFlags {
938 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
939 write!(f, "{}", self.bits)
943 impl<'tcx> PartialEq for TyS<'tcx> {
944 fn eq(&self, other: &TyS<'tcx>) -> bool {
945 (self as *const _) == (other as *const _)
948 impl<'tcx> Eq for TyS<'tcx> {}
951 impl<'tcx, S: Writer> Hash<S> for TyS<'tcx> {
952 fn hash(&self, s: &mut S) {
953 (self as *const _).hash(s)
957 impl<'tcx, S: Writer + Hasher> Hash<S> for TyS<'tcx> {
958 fn hash(&self, s: &mut S) {
959 (self as *const _).hash(s)
963 pub type Ty<'tcx> = &'tcx TyS<'tcx>;
965 /// An entry in the type interner.
966 pub struct InternedTy<'tcx> {
970 // NB: An InternedTy compares and hashes as a sty.
971 impl<'tcx> PartialEq for InternedTy<'tcx> {
972 fn eq(&self, other: &InternedTy<'tcx>) -> bool {
973 self.ty.sty == other.ty.sty
977 impl<'tcx> Eq for InternedTy<'tcx> {}
979 impl<'tcx, S: Writer + Hasher> Hash<S> for InternedTy<'tcx> {
980 fn hash(&self, s: &mut S) {
985 impl<'tcx> BorrowFrom<InternedTy<'tcx>> for sty<'tcx> {
986 fn borrow_from<'a>(ty: &'a InternedTy<'tcx>) -> &'a sty<'tcx> {
991 pub fn type_has_params(ty: Ty) -> bool {
992 ty.flags.intersects(HAS_PARAMS)
994 pub fn type_has_self(ty: Ty) -> bool {
995 ty.flags.intersects(HAS_SELF)
997 pub fn type_has_ty_infer(ty: Ty) -> bool {
998 ty.flags.intersects(HAS_TY_INFER)
1000 pub fn type_needs_infer(ty: Ty) -> bool {
1001 ty.flags.intersects(HAS_TY_INFER | HAS_RE_INFER)
1003 pub fn type_has_projection(ty: Ty) -> bool {
1004 ty.flags.intersects(HAS_PROJECTION)
1007 pub fn type_has_late_bound_regions(ty: Ty) -> bool {
1008 ty.flags.intersects(HAS_RE_LATE_BOUND)
1011 /// An "escaping region" is a bound region whose binder is not part of `t`.
1013 /// So, for example, consider a type like the following, which has two binders:
1015 /// for<'a> fn(x: for<'b> fn(&'a int, &'b int))
1016 /// ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ outer scope
1017 /// ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ inner scope
1019 /// This type has *bound regions* (`'a`, `'b`), but it does not have escaping regions, because the
1020 /// binders of both `'a` and `'b` are part of the type itself. However, if we consider the *inner
1021 /// fn type*, that type has an escaping region: `'a`.
1023 /// Note that what I'm calling an "escaping region" is often just called a "free region". However,
1024 /// we already use the term "free region". It refers to the regions that we use to represent bound
1025 /// regions on a fn definition while we are typechecking its body.
1027 /// To clarify, conceptually there is no particular difference between an "escaping" region and a
1028 /// "free" region. However, there is a big difference in practice. Basically, when "entering" a
1029 /// binding level, one is generally required to do some sort of processing to a bound region, such
1030 /// as replacing it with a fresh/skolemized region, or making an entry in the environment to
1031 /// represent the scope to which it is attached, etc. An escaping region represents a bound region
1032 /// for which this processing has not yet been done.
1033 pub fn type_has_escaping_regions(ty: Ty) -> bool {
1034 type_escapes_depth(ty, 0)
1037 pub fn type_escapes_depth(ty: Ty, depth: u32) -> bool {
1038 ty.region_depth > depth
1041 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1042 pub struct BareFnTy<'tcx> {
1043 pub unsafety: ast::Unsafety,
1045 pub sig: PolyFnSig<'tcx>,
1048 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1049 pub struct ClosureTy<'tcx> {
1050 pub unsafety: ast::Unsafety,
1051 pub onceness: ast::Onceness,
1052 pub store: TraitStore,
1053 pub bounds: ExistentialBounds<'tcx>,
1054 pub sig: PolyFnSig<'tcx>,
1058 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
1059 pub enum FnOutput<'tcx> {
1060 FnConverging(Ty<'tcx>),
1064 impl<'tcx> FnOutput<'tcx> {
1065 pub fn diverges(&self) -> bool {
1066 *self == FnDiverging
1069 pub fn unwrap(self) -> Ty<'tcx> {
1071 ty::FnConverging(t) => t,
1072 ty::FnDiverging => unreachable!()
1077 pub type PolyFnOutput<'tcx> = Binder<FnOutput<'tcx>>;
1079 impl<'tcx> PolyFnOutput<'tcx> {
1080 pub fn diverges(&self) -> bool {
1085 /// Signature of a function type, which I have arbitrarily
1086 /// decided to use to refer to the input/output types.
1088 /// - `inputs` is the list of arguments and their modes.
1089 /// - `output` is the return type.
1090 /// - `variadic` indicates whether this is a variadic function. (only true for foreign fns)
1091 #[derive(Clone, PartialEq, Eq, Hash)]
1092 pub struct FnSig<'tcx> {
1093 pub inputs: Vec<Ty<'tcx>>,
1094 pub output: FnOutput<'tcx>,
1098 pub type PolyFnSig<'tcx> = Binder<FnSig<'tcx>>;
1100 impl<'tcx> PolyFnSig<'tcx> {
1101 pub fn inputs(&self) -> ty::Binder<Vec<Ty<'tcx>>> {
1102 ty::Binder(self.0.inputs.clone())
1104 pub fn input(&self, index: uint) -> ty::Binder<Ty<'tcx>> {
1105 ty::Binder(self.0.inputs[index])
1107 pub fn output(&self) -> ty::Binder<FnOutput<'tcx>> {
1108 ty::Binder(self.0.output.clone())
1110 pub fn variadic(&self) -> bool {
1115 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
1116 pub struct ParamTy {
1117 pub space: subst::ParamSpace,
1119 pub name: ast::Name,
1122 /// A [De Bruijn index][dbi] is a standard means of representing
1123 /// regions (and perhaps later types) in a higher-ranked setting. In
1124 /// particular, imagine a type like this:
1126 /// for<'a> fn(for<'b> fn(&'b int, &'a int), &'a char)
1129 /// | +------------+ 1 | |
1131 /// +--------------------------------+ 2 |
1133 /// +------------------------------------------+ 1
1135 /// In this type, there are two binders (the outer fn and the inner
1136 /// fn). We need to be able to determine, for any given region, which
1137 /// fn type it is bound by, the inner or the outer one. There are
1138 /// various ways you can do this, but a De Bruijn index is one of the
1139 /// more convenient and has some nice properties. The basic idea is to
1140 /// count the number of binders, inside out. Some examples should help
1141 /// clarify what I mean.
1143 /// Let's start with the reference type `&'b int` that is the first
1144 /// argument to the inner function. This region `'b` is assigned a De
1145 /// Bruijn index of 1, meaning "the innermost binder" (in this case, a
1146 /// fn). The region `'a` that appears in the second argument type (`&'a
1147 /// int`) would then be assigned a De Bruijn index of 2, meaning "the
1148 /// second-innermost binder". (These indices are written on the arrays
1149 /// in the diagram).
1151 /// What is interesting is that De Bruijn index attached to a particular
1152 /// variable will vary depending on where it appears. For example,
1153 /// the final type `&'a char` also refers to the region `'a` declared on
1154 /// the outermost fn. But this time, this reference is not nested within
1155 /// any other binders (i.e., it is not an argument to the inner fn, but
1156 /// rather the outer one). Therefore, in this case, it is assigned a
1157 /// De Bruijn index of 1, because the innermost binder in that location
1158 /// is the outer fn.
1160 /// [dbi]: http://en.wikipedia.org/wiki/De_Bruijn_index
1161 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Show, Copy)]
1162 pub struct DebruijnIndex {
1163 // We maintain the invariant that this is never 0. So 1 indicates
1164 // the innermost binder. To ensure this, create with `DebruijnIndex::new`.
1168 /// Representation of regions:
1169 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Show, Copy)]
1171 // Region bound in a type or fn declaration which will be
1172 // substituted 'early' -- that is, at the same time when type
1173 // parameters are substituted.
1174 ReEarlyBound(/* param id */ ast::NodeId,
1179 // Region bound in a function scope, which will be substituted when the
1180 // function is called.
1181 ReLateBound(DebruijnIndex, BoundRegion),
1183 /// When checking a function body, the types of all arguments and so forth
1184 /// that refer to bound region parameters are modified to refer to free
1185 /// region parameters.
1188 /// A concrete region naming some expression within the current function.
1189 ReScope(region::CodeExtent),
1191 /// Static data that has an "infinite" lifetime. Top in the region lattice.
1194 /// A region variable. Should not exist after typeck.
1195 ReInfer(InferRegion),
1197 /// Empty lifetime is for data that is never accessed.
1198 /// Bottom in the region lattice. We treat ReEmpty somewhat
1199 /// specially; at least right now, we do not generate instances of
1200 /// it during the GLB computations, but rather
1201 /// generate an error instead. This is to improve error messages.
1202 /// The only way to get an instance of ReEmpty is to have a region
1203 /// variable with no constraints.
1207 /// Upvars do not get their own node-id. Instead, we use the pair of
1208 /// the original var id (that is, the root variable that is referenced
1209 /// by the upvar) and the id of the closure expression.
1210 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
1211 pub struct UpvarId {
1212 pub var_id: ast::NodeId,
1213 pub closure_expr_id: ast::NodeId,
1216 #[derive(Clone, PartialEq, Eq, Hash, Show, RustcEncodable, RustcDecodable, Copy)]
1217 pub enum BorrowKind {
1218 /// Data must be immutable and is aliasable.
1221 /// Data must be immutable but not aliasable. This kind of borrow
1222 /// cannot currently be expressed by the user and is used only in
1223 /// implicit closure bindings. It is needed when you the closure
1224 /// is borrowing or mutating a mutable referent, e.g.:
1226 /// let x: &mut int = ...;
1227 /// let y = || *x += 5;
1229 /// If we were to try to translate this closure into a more explicit
1230 /// form, we'd encounter an error with the code as written:
1232 /// struct Env { x: & &mut int }
1233 /// let x: &mut int = ...;
1234 /// let y = (&mut Env { &x }, fn_ptr); // Closure is pair of env and fn
1235 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
1237 /// This is then illegal because you cannot mutate a `&mut` found
1238 /// in an aliasable location. To solve, you'd have to translate with
1239 /// an `&mut` borrow:
1241 /// struct Env { x: & &mut int }
1242 /// let x: &mut int = ...;
1243 /// let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x
1244 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
1246 /// Now the assignment to `**env.x` is legal, but creating a
1247 /// mutable pointer to `x` is not because `x` is not mutable. We
1248 /// could fix this by declaring `x` as `let mut x`. This is ok in
1249 /// user code, if awkward, but extra weird for closures, since the
1250 /// borrow is hidden.
1252 /// So we introduce a "unique imm" borrow -- the referent is
1253 /// immutable, but not aliasable. This solves the problem. For
1254 /// simplicity, we don't give users the way to express this
1255 /// borrow, it's just used when translating closures.
1258 /// Data is mutable and not aliasable.
1262 /// Information describing the borrowing of an upvar. This is computed
1263 /// during `typeck`, specifically by `regionck`. The general idea is
1264 /// that the compiler analyses treat closures like:
1266 /// let closure: &'e fn() = || {
1267 /// x = 1; // upvar x is assigned to
1268 /// use(y); // upvar y is read
1269 /// foo(&z); // upvar z is borrowed immutably
1272 /// as if they were "desugared" to something loosely like:
1274 /// struct Vars<'x,'y,'z> { x: &'x mut int,
1275 /// y: &'y const int,
1277 /// let closure: &'e fn() = {
1278 /// fn f(env: &Vars) {
1283 /// let env: &'e mut Vars<'x,'y,'z> = &mut Vars { x: &'x mut x,
1289 /// This is basically what happens at runtime. The closure is basically
1290 /// an existentially quantified version of the `(env, f)` pair.
1292 /// This data structure indicates the region and mutability of a single
1293 /// one of the `x...z` borrows.
1295 /// It may not be obvious why each borrowed variable gets its own
1296 /// lifetime (in the desugared version of the example, these are indicated
1297 /// by the lifetime parameters `'x`, `'y`, and `'z` in the `Vars` definition).
1298 /// Each such lifetime must encompass the lifetime `'e` of the closure itself,
1299 /// but need not be identical to it. The reason that this makes sense:
1301 /// - Callers are only permitted to invoke the closure, and hence to
1302 /// use the pointers, within the lifetime `'e`, so clearly `'e` must
1303 /// be a sublifetime of `'x...'z`.
1304 /// - The closure creator knows which upvars were borrowed by the closure
1305 /// and thus `x...z` will be reserved for `'x...'z` respectively.
1306 /// - Through mutation, the borrowed upvars can actually escape
1307 /// the closure, so sometimes it is necessary for them to be larger
1308 /// than the closure lifetime itself.
1309 #[derive(PartialEq, Clone, RustcEncodable, RustcDecodable, Show, Copy)]
1310 pub struct UpvarBorrow {
1311 pub kind: BorrowKind,
1312 pub region: ty::Region,
1315 pub type UpvarBorrowMap = FnvHashMap<UpvarId, UpvarBorrow>;
1318 pub fn is_bound(&self) -> bool {
1320 ty::ReEarlyBound(..) => true,
1321 ty::ReLateBound(..) => true,
1326 pub fn escapes_depth(&self, depth: u32) -> bool {
1328 ty::ReLateBound(debruijn, _) => debruijn.depth > depth,
1334 #[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
1335 RustcEncodable, RustcDecodable, Show, Copy)]
1336 /// A "free" region `fr` can be interpreted as "some region
1337 /// at least as big as the scope `fr.scope`".
1338 pub struct FreeRegion {
1339 pub scope: region::CodeExtent,
1340 pub bound_region: BoundRegion
1343 #[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
1344 RustcEncodable, RustcDecodable, Show, Copy)]
1345 pub enum BoundRegion {
1346 /// An anonymous region parameter for a given fn (&T)
1349 /// Named region parameters for functions (a in &'a T)
1351 /// The def-id is needed to distinguish free regions in
1352 /// the event of shadowing.
1353 BrNamed(ast::DefId, ast::Name),
1355 /// Fresh bound identifiers created during GLB computations.
1358 // Anonymous region for the implicit env pointer parameter
1363 // NB: If you change this, you'll probably want to change the corresponding
1364 // AST structure in libsyntax/ast.rs as well.
1365 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1366 pub enum sty<'tcx> {
1370 ty_uint(ast::UintTy),
1371 ty_float(ast::FloatTy),
1372 /// Substs here, possibly against intuition, *may* contain `ty_param`s.
1373 /// That is, even after substitution it is possible that there are type
1374 /// variables. This happens when the `ty_enum` corresponds to an enum
1375 /// definition and not a concrete use of it. To get the correct `ty_enum`
1376 /// from the tcx, use the `NodeId` from the `ast::Ty` and look it up in
1377 /// the `ast_ty_to_ty_cache`. This is probably true for `ty_struct` as
1379 ty_enum(DefId, &'tcx Substs<'tcx>),
1382 ty_vec(Ty<'tcx>, Option<uint>), // Second field is length.
1384 ty_rptr(&'tcx Region, mt<'tcx>),
1386 // If the def-id is Some(_), then this is the type of a specific
1387 // fn item. Otherwise, if None(_), it a fn pointer type.
1388 ty_bare_fn(Option<DefId>, &'tcx BareFnTy<'tcx>),
1390 ty_trait(Box<TyTrait<'tcx>>),
1391 ty_struct(DefId, &'tcx Substs<'tcx>),
1393 ty_unboxed_closure(DefId, &'tcx Region, &'tcx Substs<'tcx>),
1395 ty_tup(Vec<Ty<'tcx>>),
1397 ty_projection(ProjectionTy<'tcx>),
1398 ty_param(ParamTy), // type parameter
1400 ty_open(Ty<'tcx>), // A deref'ed fat pointer, i.e., a dynamically sized value
1401 // and its size. Only ever used in trans. It is not necessary
1402 // earlier since we don't need to distinguish a DST with its
1403 // size (e.g., in a deref) vs a DST with the size elsewhere (
1404 // e.g., in a field).
1406 ty_infer(InferTy), // something used only during inference/typeck
1407 ty_err, // Also only used during inference/typeck, to represent
1408 // the type of an erroneous expression (helps cut down
1409 // on non-useful type error messages)
1412 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1413 pub struct TyTrait<'tcx> {
1414 pub principal: ty::PolyTraitRef<'tcx>,
1415 pub bounds: ExistentialBounds<'tcx>,
1418 impl<'tcx> TyTrait<'tcx> {
1419 pub fn principal_def_id(&self) -> ast::DefId {
1420 self.principal.0.def_id
1423 /// Object types don't have a self-type specified. Therefore, when
1424 /// we convert the principal trait-ref into a normal trait-ref,
1425 /// you must give *some* self-type. A common choice is `mk_err()`
1426 /// or some skolemized type.
1427 pub fn principal_trait_ref_with_self_ty(&self,
1430 -> ty::PolyTraitRef<'tcx>
1432 // otherwise the escaping regions would be captured by the binder
1433 assert!(!self_ty.has_escaping_regions());
1435 ty::Binder(Rc::new(ty::TraitRef {
1436 def_id: self.principal.0.def_id,
1437 substs: tcx.mk_substs(self.principal.0.substs.with_self_ty(self_ty)),
1441 pub fn projection_bounds_with_self_ty(&self,
1444 -> Vec<ty::PolyProjectionPredicate<'tcx>>
1446 // otherwise the escaping regions would be captured by the binders
1447 assert!(!self_ty.has_escaping_regions());
1449 self.bounds.projection_bounds.iter()
1450 .map(|in_poly_projection_predicate| {
1451 let in_projection_ty = &in_poly_projection_predicate.0.projection_ty;
1452 let substs = tcx.mk_substs(in_projection_ty.trait_ref.substs.with_self_ty(self_ty));
1454 Rc::new(ty::TraitRef::new(in_projection_ty.trait_ref.def_id,
1456 let projection_ty = ty::ProjectionTy {
1457 trait_ref: trait_ref,
1458 item_name: in_projection_ty.item_name
1460 ty::Binder(ty::ProjectionPredicate {
1461 projection_ty: projection_ty,
1462 ty: in_poly_projection_predicate.0.ty
1469 /// A complete reference to a trait. These take numerous guises in syntax,
1470 /// but perhaps the most recognizable form is in a where clause:
1474 /// This would be represented by a trait-reference where the def-id is the
1475 /// def-id for the trait `Foo` and the substs defines `T` as parameter 0 in the
1476 /// `SelfSpace` and `U` as parameter 0 in the `TypeSpace`.
1478 /// Trait references also appear in object types like `Foo<U>`, but in
1479 /// that case the `Self` parameter is absent from the substitutions.
1481 /// Note that a `TraitRef` introduces a level of region binding, to
1482 /// account for higher-ranked trait bounds like `T : for<'a> Foo<&'a
1483 /// U>` or higher-ranked object types.
1484 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1485 pub struct TraitRef<'tcx> {
1487 pub substs: &'tcx Substs<'tcx>,
1490 pub type PolyTraitRef<'tcx> = Binder<Rc<TraitRef<'tcx>>>;
1492 impl<'tcx> PolyTraitRef<'tcx> {
1493 pub fn self_ty(&self) -> Ty<'tcx> {
1497 pub fn def_id(&self) -> ast::DefId {
1501 pub fn substs(&self) -> &'tcx Substs<'tcx> {
1502 // FIXME(#20664) every use of this fn is probably a bug, it should yield Binder<>
1506 pub fn input_types(&self) -> &[Ty<'tcx>] {
1507 // FIXME(#20664) every use of this fn is probably a bug, it should yield Binder<>
1508 self.0.input_types()
1511 pub fn to_poly_trait_predicate(&self) -> PolyTraitPredicate<'tcx> {
1512 // Note that we preserve binding levels
1513 Binder(TraitPredicate { trait_ref: self.0.clone() })
1517 /// Binder is a binder for higher-ranked lifetimes. It is part of the
1518 /// compiler's representation for things like `for<'a> Fn(&'a int)`
1519 /// (which would be represented by the type `PolyTraitRef ==
1520 /// Binder<TraitRef>`). Note that when we skolemize, instantiate,
1521 /// erase, or otherwise "discharge" these bound reons, we change the
1522 /// type from `Binder<T>` to just `T` (see
1523 /// e.g. `liberate_late_bound_regions`).
1524 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1525 pub struct Binder<T>(pub T);
1527 #[derive(Clone, Copy, PartialEq)]
1528 pub enum IntVarValue {
1529 IntType(ast::IntTy),
1530 UintType(ast::UintTy),
1533 #[derive(Clone, Copy, Show)]
1534 pub enum terr_vstore_kind {
1541 #[derive(Clone, Copy, Show)]
1542 pub struct expected_found<T> {
1547 // Data structures used in type unification
1548 #[derive(Clone, Copy, Show)]
1549 pub enum type_err<'tcx> {
1551 terr_unsafety_mismatch(expected_found<ast::Unsafety>),
1552 terr_onceness_mismatch(expected_found<Onceness>),
1553 terr_abi_mismatch(expected_found<abi::Abi>),
1555 terr_sigil_mismatch(expected_found<TraitStore>),
1556 terr_box_mutability,
1557 terr_ptr_mutability,
1558 terr_ref_mutability,
1559 terr_vec_mutability,
1560 terr_tuple_size(expected_found<uint>),
1561 terr_fixed_array_size(expected_found<uint>),
1562 terr_ty_param_size(expected_found<uint>),
1564 terr_regions_does_not_outlive(Region, Region),
1565 terr_regions_not_same(Region, Region),
1566 terr_regions_no_overlap(Region, Region),
1567 terr_regions_insufficiently_polymorphic(BoundRegion, Region),
1568 terr_regions_overly_polymorphic(BoundRegion, Region),
1569 terr_trait_stores_differ(terr_vstore_kind, expected_found<TraitStore>),
1570 terr_sorts(expected_found<Ty<'tcx>>),
1571 terr_integer_as_char,
1572 terr_int_mismatch(expected_found<IntVarValue>),
1573 terr_float_mismatch(expected_found<ast::FloatTy>),
1574 terr_traits(expected_found<ast::DefId>),
1575 terr_builtin_bounds(expected_found<BuiltinBounds>),
1576 terr_variadic_mismatch(expected_found<bool>),
1578 terr_convergence_mismatch(expected_found<bool>),
1579 terr_projection_name_mismatched(expected_found<ast::Name>),
1580 terr_projection_bounds_length(expected_found<uint>),
1583 /// Bounds suitable for a named type parameter like `A` in `fn foo<A>`
1584 /// as well as the existential type parameter in an object type.
1585 #[derive(PartialEq, Eq, Hash, Clone, Show)]
1586 pub struct ParamBounds<'tcx> {
1587 pub region_bounds: Vec<ty::Region>,
1588 pub builtin_bounds: BuiltinBounds,
1589 pub trait_bounds: Vec<PolyTraitRef<'tcx>>,
1590 pub projection_bounds: Vec<PolyProjectionPredicate<'tcx>>,
1593 /// Bounds suitable for an existentially quantified type parameter
1594 /// such as those that appear in object types or closure types. The
1595 /// major difference between this case and `ParamBounds` is that
1596 /// general purpose trait bounds are omitted and there must be
1597 /// *exactly one* region.
1598 #[derive(PartialEq, Eq, Hash, Clone, Show)]
1599 pub struct ExistentialBounds<'tcx> {
1600 pub region_bound: ty::Region,
1601 pub builtin_bounds: BuiltinBounds,
1602 pub projection_bounds: Vec<PolyProjectionPredicate<'tcx>>,
1605 pub type BuiltinBounds = EnumSet<BuiltinBound>;
1607 #[derive(Clone, RustcEncodable, PartialEq, Eq, RustcDecodable, Hash,
1610 pub enum BuiltinBound {
1617 pub fn empty_builtin_bounds() -> BuiltinBounds {
1621 pub fn all_builtin_bounds() -> BuiltinBounds {
1622 let mut set = EnumSet::new();
1623 set.insert(BoundSend);
1624 set.insert(BoundSized);
1625 set.insert(BoundSync);
1629 /// An existential bound that does not implement any traits.
1630 pub fn region_existential_bound<'tcx>(r: ty::Region) -> ExistentialBounds<'tcx> {
1631 ty::ExistentialBounds { region_bound: r,
1632 builtin_bounds: empty_builtin_bounds(),
1633 projection_bounds: Vec::new() }
1636 impl CLike for BuiltinBound {
1637 fn to_uint(&self) -> uint {
1640 fn from_uint(v: uint) -> BuiltinBound {
1641 unsafe { mem::transmute(v) }
1645 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1650 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1655 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1656 pub struct FloatVid {
1660 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
1661 pub struct RegionVid {
1665 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1671 /// A `FreshTy` is one that is generated as a replacement for an
1672 /// unbound type variable. This is convenient for caching etc. See
1673 /// `middle::infer::freshen` for more details.
1676 // FIXME -- once integral fallback is impl'd, we should remove
1677 // this type. It's only needed to prevent spurious errors for
1678 // integers whose type winds up never being constrained.
1682 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Show, Copy)]
1683 pub enum UnconstrainedNumeric {
1690 #[derive(Clone, RustcEncodable, RustcDecodable, Eq, Hash, Show, Copy)]
1691 pub enum InferRegion {
1693 ReSkolemized(u32, BoundRegion)
1696 impl cmp::PartialEq for InferRegion {
1697 fn eq(&self, other: &InferRegion) -> bool {
1698 match ((*self), *other) {
1699 (ReVar(rva), ReVar(rvb)) => {
1702 (ReSkolemized(rva, _), ReSkolemized(rvb, _)) => {
1708 fn ne(&self, other: &InferRegion) -> bool {
1709 !((*self) == (*other))
1713 impl fmt::Show for TyVid {
1714 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result{
1715 write!(f, "_#{}t", self.index)
1719 impl fmt::Show for IntVid {
1720 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1721 write!(f, "_#{}i", self.index)
1725 impl fmt::Show for FloatVid {
1726 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1727 write!(f, "_#{}f", self.index)
1731 impl fmt::Show for RegionVid {
1732 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1733 write!(f, "'_#{}r", self.index)
1737 impl<'tcx> fmt::Show for FnSig<'tcx> {
1738 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1739 write!(f, "({:?}; variadic: {})->{:?}", self.inputs, self.variadic, self.output)
1743 impl fmt::Show for InferTy {
1744 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1746 TyVar(ref v) => v.fmt(f),
1747 IntVar(ref v) => v.fmt(f),
1748 FloatVar(ref v) => v.fmt(f),
1749 FreshTy(v) => write!(f, "FreshTy({:?})", v),
1750 FreshIntTy(v) => write!(f, "FreshIntTy({:?})", v),
1755 impl fmt::Show for IntVarValue {
1756 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1758 IntType(ref v) => v.fmt(f),
1759 UintType(ref v) => v.fmt(f),
1764 #[derive(Clone, Show)]
1765 pub struct TypeParameterDef<'tcx> {
1766 pub name: ast::Name,
1767 pub def_id: ast::DefId,
1768 pub space: subst::ParamSpace,
1770 pub bounds: ParamBounds<'tcx>,
1771 pub default: Option<Ty<'tcx>>,
1774 #[derive(RustcEncodable, RustcDecodable, Clone, Show)]
1775 pub struct RegionParameterDef {
1776 pub name: ast::Name,
1777 pub def_id: ast::DefId,
1778 pub space: subst::ParamSpace,
1780 pub bounds: Vec<ty::Region>,
1783 impl RegionParameterDef {
1784 pub fn to_early_bound_region(&self) -> ty::Region {
1785 ty::ReEarlyBound(self.def_id.node, self.space, self.index, self.name)
1789 /// Information about the formal type/lifetime parameters associated
1790 /// with an item or method. Analogous to ast::Generics.
1791 #[derive(Clone, Show)]
1792 pub struct Generics<'tcx> {
1793 pub types: VecPerParamSpace<TypeParameterDef<'tcx>>,
1794 pub regions: VecPerParamSpace<RegionParameterDef>,
1795 pub predicates: VecPerParamSpace<Predicate<'tcx>>,
1798 impl<'tcx> Generics<'tcx> {
1799 pub fn empty() -> Generics<'tcx> {
1801 types: VecPerParamSpace::empty(),
1802 regions: VecPerParamSpace::empty(),
1803 predicates: VecPerParamSpace::empty(),
1807 pub fn has_type_params(&self, space: subst::ParamSpace) -> bool {
1808 !self.types.is_empty_in(space)
1811 pub fn has_region_params(&self, space: subst::ParamSpace) -> bool {
1812 !self.regions.is_empty_in(space)
1815 pub fn is_empty(&self) -> bool {
1816 self.types.is_empty() && self.regions.is_empty()
1819 pub fn to_bounds(&self, tcx: &ty::ctxt<'tcx>, substs: &Substs<'tcx>)
1820 -> GenericBounds<'tcx> {
1822 predicates: self.predicates.subst(tcx, substs),
1827 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1828 pub enum Predicate<'tcx> {
1829 /// Corresponds to `where Foo : Bar<A,B,C>`. `Foo` here would be
1830 /// the `Self` type of the trait reference and `A`, `B`, and `C`
1831 /// would be the parameters in the `TypeSpace`.
1832 Trait(PolyTraitPredicate<'tcx>),
1834 /// where `T1 == T2`.
1835 Equate(PolyEquatePredicate<'tcx>),
1838 RegionOutlives(PolyRegionOutlivesPredicate),
1841 TypeOutlives(PolyTypeOutlivesPredicate<'tcx>),
1843 /// where <T as TraitRef>::Name == X, approximately.
1844 /// See `ProjectionPredicate` struct for details.
1845 Projection(PolyProjectionPredicate<'tcx>),
1848 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1849 pub struct TraitPredicate<'tcx> {
1850 pub trait_ref: Rc<TraitRef<'tcx>>
1852 pub type PolyTraitPredicate<'tcx> = ty::Binder<TraitPredicate<'tcx>>;
1854 impl<'tcx> TraitPredicate<'tcx> {
1855 pub fn def_id(&self) -> ast::DefId {
1856 self.trait_ref.def_id
1859 pub fn input_types(&self) -> &[Ty<'tcx>] {
1860 self.trait_ref.substs.types.as_slice()
1863 pub fn self_ty(&self) -> Ty<'tcx> {
1864 self.trait_ref.self_ty()
1868 impl<'tcx> PolyTraitPredicate<'tcx> {
1869 pub fn def_id(&self) -> ast::DefId {
1874 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1875 pub struct EquatePredicate<'tcx>(pub Ty<'tcx>, pub Ty<'tcx>); // `0 == 1`
1876 pub type PolyEquatePredicate<'tcx> = ty::Binder<EquatePredicate<'tcx>>;
1878 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1879 pub struct OutlivesPredicate<A,B>(pub A, pub B); // `A : B`
1880 pub type PolyOutlivesPredicate<A,B> = ty::Binder<OutlivesPredicate<A,B>>;
1881 pub type PolyRegionOutlivesPredicate = PolyOutlivesPredicate<ty::Region, ty::Region>;
1882 pub type PolyTypeOutlivesPredicate<'tcx> = PolyOutlivesPredicate<Ty<'tcx>, ty::Region>;
1884 /// This kind of predicate has no *direct* correspondent in the
1885 /// syntax, but it roughly corresponds to the syntactic forms:
1887 /// 1. `T : TraitRef<..., Item=Type>`
1888 /// 2. `<T as TraitRef<...>>::Item == Type` (NYI)
1890 /// In particular, form #1 is "desugared" to the combination of a
1891 /// normal trait predicate (`T : TraitRef<...>`) and one of these
1892 /// predicates. Form #2 is a broader form in that it also permits
1893 /// equality between arbitrary types. Processing an instance of Form
1894 /// \#2 eventually yields one of these `ProjectionPredicate`
1895 /// instances to normalize the LHS.
1896 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1897 pub struct ProjectionPredicate<'tcx> {
1898 pub projection_ty: ProjectionTy<'tcx>,
1902 pub type PolyProjectionPredicate<'tcx> = Binder<ProjectionPredicate<'tcx>>;
1904 impl<'tcx> PolyProjectionPredicate<'tcx> {
1905 pub fn item_name(&self) -> ast::Name {
1906 self.0.projection_ty.item_name // safe to skip the binder to access a name
1909 pub fn sort_key(&self) -> (ast::DefId, ast::Name) {
1910 self.0.projection_ty.sort_key()
1914 /// Represents the projection of an associated type. In explicit UFCS
1915 /// form this would be written `<T as Trait<..>>::N`.
1916 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1917 pub struct ProjectionTy<'tcx> {
1918 /// The trait reference `T as Trait<..>`.
1919 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
1921 /// The name `N` of the associated type.
1922 pub item_name: ast::Name,
1925 impl<'tcx> ProjectionTy<'tcx> {
1926 pub fn sort_key(&self) -> (ast::DefId, ast::Name) {
1927 (self.trait_ref.def_id, self.item_name)
1931 pub trait ToPolyTraitRef<'tcx> {
1932 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx>;
1935 impl<'tcx> ToPolyTraitRef<'tcx> for Rc<TraitRef<'tcx>> {
1936 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1937 assert!(!self.has_escaping_regions());
1938 ty::Binder(self.clone())
1942 impl<'tcx> ToPolyTraitRef<'tcx> for PolyTraitPredicate<'tcx> {
1943 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1944 // We are just preserving the binder levels here
1945 ty::Binder(self.0.trait_ref.clone())
1949 impl<'tcx> ToPolyTraitRef<'tcx> for PolyProjectionPredicate<'tcx> {
1950 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1951 // Note: unlike with TraitRef::to_poly_trait_ref(),
1952 // self.0.trait_ref is permitted to have escaping regions.
1953 // This is because here `self` has a `Binder` and so does our
1954 // return value, so we are preserving the number of binding
1956 ty::Binder(self.0.projection_ty.trait_ref.clone())
1960 pub trait AsPredicate<'tcx> {
1961 fn as_predicate(&self) -> Predicate<'tcx>;
1964 impl<'tcx> AsPredicate<'tcx> for Rc<TraitRef<'tcx>> {
1965 fn as_predicate(&self) -> Predicate<'tcx> {
1966 // we're about to add a binder, so let's check that we don't
1967 // accidentally capture anything, or else that might be some
1968 // weird debruijn accounting.
1969 assert!(!self.has_escaping_regions());
1971 ty::Predicate::Trait(ty::Binder(ty::TraitPredicate {
1972 trait_ref: self.clone()
1977 impl<'tcx> AsPredicate<'tcx> for PolyTraitRef<'tcx> {
1978 fn as_predicate(&self) -> Predicate<'tcx> {
1979 ty::Predicate::Trait(self.to_poly_trait_predicate())
1983 impl<'tcx> AsPredicate<'tcx> for PolyEquatePredicate<'tcx> {
1984 fn as_predicate(&self) -> Predicate<'tcx> {
1985 Predicate::Equate(self.clone())
1989 impl<'tcx> AsPredicate<'tcx> for PolyRegionOutlivesPredicate {
1990 fn as_predicate(&self) -> Predicate<'tcx> {
1991 Predicate::RegionOutlives(self.clone())
1995 impl<'tcx> AsPredicate<'tcx> for PolyTypeOutlivesPredicate<'tcx> {
1996 fn as_predicate(&self) -> Predicate<'tcx> {
1997 Predicate::TypeOutlives(self.clone())
2001 impl<'tcx> AsPredicate<'tcx> for PolyProjectionPredicate<'tcx> {
2002 fn as_predicate(&self) -> Predicate<'tcx> {
2003 Predicate::Projection(self.clone())
2007 impl<'tcx> Predicate<'tcx> {
2008 pub fn has_escaping_regions(&self) -> bool {
2010 Predicate::Trait(ref trait_ref) => trait_ref.has_escaping_regions(),
2011 Predicate::Equate(ref p) => p.has_escaping_regions(),
2012 Predicate::RegionOutlives(ref p) => p.has_escaping_regions(),
2013 Predicate::TypeOutlives(ref p) => p.has_escaping_regions(),
2014 Predicate::Projection(ref p) => p.has_escaping_regions(),
2018 pub fn to_opt_poly_trait_ref(&self) -> Option<PolyTraitRef<'tcx>> {
2020 Predicate::Trait(ref t) => {
2021 Some(t.to_poly_trait_ref())
2023 Predicate::Projection(..) |
2024 Predicate::Equate(..) |
2025 Predicate::RegionOutlives(..) |
2026 Predicate::TypeOutlives(..) => {
2033 /// Represents the bounds declared on a particular set of type
2034 /// parameters. Should eventually be generalized into a flag list of
2035 /// where clauses. You can obtain a `GenericBounds` list from a
2036 /// `Generics` by using the `to_bounds` method. Note that this method
2037 /// reflects an important semantic invariant of `GenericBounds`: while
2038 /// the bounds in a `Generics` are expressed in terms of the bound type
2039 /// parameters of the impl/trait/whatever, a `GenericBounds` instance
2040 /// represented a set of bounds for some particular instantiation,
2041 /// meaning that the generic parameters have been substituted with
2046 /// struct Foo<T,U:Bar<T>> { ... }
2048 /// Here, the `Generics` for `Foo` would contain a list of bounds like
2049 /// `[[], [U:Bar<T>]]`. Now if there were some particular reference
2050 /// like `Foo<int,uint>`, then the `GenericBounds` would be `[[],
2051 /// [uint:Bar<int>]]`.
2052 #[derive(Clone, Show)]
2053 pub struct GenericBounds<'tcx> {
2054 pub predicates: VecPerParamSpace<Predicate<'tcx>>,
2057 impl<'tcx> GenericBounds<'tcx> {
2058 pub fn empty() -> GenericBounds<'tcx> {
2059 GenericBounds { predicates: VecPerParamSpace::empty() }
2062 pub fn has_escaping_regions(&self) -> bool {
2063 self.predicates.any(|p| p.has_escaping_regions())
2066 pub fn is_empty(&self) -> bool {
2067 self.predicates.is_empty()
2071 impl<'tcx> TraitRef<'tcx> {
2072 pub fn new(def_id: ast::DefId, substs: &'tcx Substs<'tcx>) -> TraitRef<'tcx> {
2073 TraitRef { def_id: def_id, substs: substs }
2076 pub fn self_ty(&self) -> Ty<'tcx> {
2077 self.substs.self_ty().unwrap()
2080 pub fn input_types(&self) -> &[Ty<'tcx>] {
2081 // Select only the "input types" from a trait-reference. For
2082 // now this is all the types that appear in the
2083 // trait-reference, but it should eventually exclude
2084 // associated types.
2085 self.substs.types.as_slice()
2089 /// When type checking, we use the `ParameterEnvironment` to track
2090 /// details about the type/lifetime parameters that are in scope.
2091 /// It primarily stores the bounds information.
2093 /// Note: This information might seem to be redundant with the data in
2094 /// `tcx.ty_param_defs`, but it is not. That table contains the
2095 /// parameter definitions from an "outside" perspective, but this
2096 /// struct will contain the bounds for a parameter as seen from inside
2097 /// the function body. Currently the only real distinction is that
2098 /// bound lifetime parameters are replaced with free ones, but in the
2099 /// future I hope to refine the representation of types so as to make
2100 /// more distinctions clearer.
2102 pub struct ParameterEnvironment<'a, 'tcx:'a> {
2103 pub tcx: &'a ctxt<'tcx>,
2105 /// A substitution that can be applied to move from
2106 /// the "outer" view of a type or method to the "inner" view.
2107 /// In general, this means converting from bound parameters to
2108 /// free parameters. Since we currently represent bound/free type
2109 /// parameters in the same way, this only has an effect on regions.
2110 pub free_substs: Substs<'tcx>,
2112 /// Each type parameter has an implicit region bound that
2113 /// indicates it must outlive at least the function body (the user
2114 /// may specify stronger requirements). This field indicates the
2115 /// region of the callee.
2116 pub implicit_region_bound: ty::Region,
2118 /// Obligations that the caller must satisfy. This is basically
2119 /// the set of bounds on the in-scope type parameters, translated
2120 /// into Obligations.
2121 pub caller_bounds: ty::GenericBounds<'tcx>,
2123 /// Caches the results of trait selection. This cache is used
2124 /// for things that have to do with the parameters in scope.
2125 pub selection_cache: traits::SelectionCache<'tcx>,
2128 impl<'a, 'tcx> ParameterEnvironment<'a, 'tcx> {
2129 pub fn for_item(cx: &'a ctxt<'tcx>, id: NodeId) -> ParameterEnvironment<'a, 'tcx> {
2130 match cx.map.find(id) {
2131 Some(ast_map::NodeImplItem(ref impl_item)) => {
2133 ast::MethodImplItem(ref method) => {
2134 let method_def_id = ast_util::local_def(id);
2135 match ty::impl_or_trait_item(cx, method_def_id) {
2136 MethodTraitItem(ref method_ty) => {
2137 let method_generics = &method_ty.generics;
2138 construct_parameter_environment(
2141 method.pe_body().id)
2143 TypeTraitItem(_) => {
2145 .bug("ParameterEnvironment::for_item(): \
2146 can't create a parameter environment \
2147 for type trait items")
2151 ast::TypeImplItem(_) => {
2152 cx.sess.bug("ParameterEnvironment::for_item(): \
2153 can't create a parameter environment \
2154 for type impl items")
2158 Some(ast_map::NodeTraitItem(trait_method)) => {
2159 match *trait_method {
2160 ast::RequiredMethod(ref required) => {
2161 cx.sess.span_bug(required.span,
2162 "ParameterEnvironment::for_item():
2163 can't create a parameter \
2164 environment for required trait \
2167 ast::ProvidedMethod(ref method) => {
2168 let method_def_id = ast_util::local_def(id);
2169 match ty::impl_or_trait_item(cx, method_def_id) {
2170 MethodTraitItem(ref method_ty) => {
2171 let method_generics = &method_ty.generics;
2172 construct_parameter_environment(
2175 method.pe_body().id)
2177 TypeTraitItem(_) => {
2179 .bug("ParameterEnvironment::for_item(): \
2180 can't create a parameter environment \
2181 for type trait items")
2185 ast::TypeTraitItem(_) => {
2186 cx.sess.bug("ParameterEnvironment::from_item(): \
2187 can't create a parameter environment \
2188 for type trait items")
2192 Some(ast_map::NodeItem(item)) => {
2194 ast::ItemFn(_, _, _, _, ref body) => {
2195 // We assume this is a function.
2196 let fn_def_id = ast_util::local_def(id);
2197 let fn_pty = ty::lookup_item_type(cx, fn_def_id);
2199 construct_parameter_environment(cx,
2204 ast::ItemStruct(..) |
2206 ast::ItemConst(..) |
2207 ast::ItemStatic(..) => {
2208 let def_id = ast_util::local_def(id);
2209 let pty = ty::lookup_item_type(cx, def_id);
2210 construct_parameter_environment(cx, &pty.generics, id)
2213 cx.sess.span_bug(item.span,
2214 "ParameterEnvironment::from_item():
2215 can't create a parameter \
2216 environment for this kind of item")
2220 Some(ast_map::NodeExpr(..)) => {
2221 // This is a convenience to allow closures to work.
2222 ParameterEnvironment::for_item(cx, cx.map.get_parent(id))
2225 cx.sess.bug(&format!("ParameterEnvironment::from_item(): \
2226 `{}` is not an item",
2227 cx.map.node_to_string(id))[])
2233 /// A "type scheme", in ML terminology, is a type combined with some
2234 /// set of generic types that the type is, well, generic over. In Rust
2235 /// terms, it is the "type" of a fn item or struct -- this type will
2236 /// include various generic parameters that must be substituted when
2237 /// the item/struct is referenced. That is called converting the type
2238 /// scheme to a monotype.
2240 /// - `generics`: the set of type parameters and their bounds
2241 /// - `ty`: the base types, which may reference the parameters defined
2244 /// Note that TypeSchemes are also sometimes called "polytypes" (and
2245 /// in fact this struct used to carry that name, so you may find some
2246 /// stray references in a comment or something). We try to reserve the
2247 /// "poly" prefix to refer to higher-ranked things, as in
2249 #[derive(Clone, Show)]
2250 pub struct TypeScheme<'tcx> {
2251 pub generics: Generics<'tcx>,
2255 /// As `TypeScheme` but for a trait ref.
2256 pub struct TraitDef<'tcx> {
2257 pub unsafety: ast::Unsafety,
2259 /// Generic type definitions. Note that `Self` is listed in here
2260 /// as having a single bound, the trait itself (e.g., in the trait
2261 /// `Eq`, there is a single bound `Self : Eq`). This is so that
2262 /// default methods get to assume that the `Self` parameters
2263 /// implements the trait.
2264 pub generics: Generics<'tcx>,
2266 /// The "supertrait" bounds.
2267 pub bounds: ParamBounds<'tcx>,
2269 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
2271 /// A list of the associated types defined in this trait. Useful
2272 /// for resolving `X::Foo` type markers.
2273 pub associated_type_names: Vec<ast::Name>,
2276 /// Records the substitutions used to translate the polytype for an
2277 /// item into the monotype of an item reference.
2279 pub struct ItemSubsts<'tcx> {
2280 pub substs: Substs<'tcx>,
2283 /// Records information about each unboxed closure.
2285 pub struct UnboxedClosure<'tcx> {
2286 /// The type of the unboxed closure.
2287 pub closure_type: ClosureTy<'tcx>,
2288 /// The kind of unboxed closure this is.
2289 pub kind: UnboxedClosureKind,
2292 #[derive(Clone, Copy, PartialEq, Eq, Show)]
2293 pub enum UnboxedClosureKind {
2294 FnUnboxedClosureKind,
2295 FnMutUnboxedClosureKind,
2296 FnOnceUnboxedClosureKind,
2299 impl UnboxedClosureKind {
2300 pub fn trait_did(&self, cx: &ctxt) -> ast::DefId {
2301 let result = match *self {
2302 FnUnboxedClosureKind => cx.lang_items.require(FnTraitLangItem),
2303 FnMutUnboxedClosureKind => {
2304 cx.lang_items.require(FnMutTraitLangItem)
2306 FnOnceUnboxedClosureKind => {
2307 cx.lang_items.require(FnOnceTraitLangItem)
2311 Ok(trait_did) => trait_did,
2312 Err(err) => cx.sess.fatal(&err[]),
2317 pub trait UnboxedClosureTyper<'tcx> {
2318 fn param_env<'a>(&'a self) -> &'a ty::ParameterEnvironment<'a, 'tcx>;
2320 fn unboxed_closure_kind(&self,
2322 -> ty::UnboxedClosureKind;
2324 fn unboxed_closure_type(&self,
2326 substs: &subst::Substs<'tcx>)
2327 -> ty::ClosureTy<'tcx>;
2329 // Returns `None` if the upvar types cannot yet be definitively determined.
2330 fn unboxed_closure_upvars(&self,
2332 substs: &Substs<'tcx>)
2333 -> Option<Vec<UnboxedClosureUpvar<'tcx>>>;
2336 impl<'tcx> CommonTypes<'tcx> {
2337 fn new(arena: &'tcx TypedArena<TyS<'tcx>>,
2338 interner: &mut FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>)
2339 -> CommonTypes<'tcx>
2342 bool: intern_ty(arena, interner, ty_bool),
2343 char: intern_ty(arena, interner, ty_char),
2344 err: intern_ty(arena, interner, ty_err),
2345 int: intern_ty(arena, interner, ty_int(ast::TyIs(false))),
2346 i8: intern_ty(arena, interner, ty_int(ast::TyI8)),
2347 i16: intern_ty(arena, interner, ty_int(ast::TyI16)),
2348 i32: intern_ty(arena, interner, ty_int(ast::TyI32)),
2349 i64: intern_ty(arena, interner, ty_int(ast::TyI64)),
2350 uint: intern_ty(arena, interner, ty_uint(ast::TyUs(false))),
2351 u8: intern_ty(arena, interner, ty_uint(ast::TyU8)),
2352 u16: intern_ty(arena, interner, ty_uint(ast::TyU16)),
2353 u32: intern_ty(arena, interner, ty_uint(ast::TyU32)),
2354 u64: intern_ty(arena, interner, ty_uint(ast::TyU64)),
2355 f32: intern_ty(arena, interner, ty_float(ast::TyF32)),
2356 f64: intern_ty(arena, interner, ty_float(ast::TyF64)),
2361 pub fn mk_ctxt<'tcx>(s: Session,
2362 arenas: &'tcx CtxtArenas<'tcx>,
2364 named_region_map: resolve_lifetime::NamedRegionMap,
2365 map: ast_map::Map<'tcx>,
2366 freevars: RefCell<FreevarMap>,
2367 capture_modes: RefCell<CaptureModeMap>,
2368 region_maps: middle::region::RegionMaps,
2369 lang_items: middle::lang_items::LanguageItems,
2370 stability: stability::Index) -> ctxt<'tcx>
2372 let mut interner = FnvHashMap::new();
2373 let common_types = CommonTypes::new(&arenas.type_, &mut interner);
2377 interner: RefCell::new(interner),
2378 substs_interner: RefCell::new(FnvHashMap::new()),
2379 bare_fn_interner: RefCell::new(FnvHashMap::new()),
2380 region_interner: RefCell::new(FnvHashMap::new()),
2381 types: common_types,
2382 named_region_map: named_region_map,
2383 item_variance_map: RefCell::new(DefIdMap::new()),
2384 variance_computed: Cell::new(false),
2387 region_maps: region_maps,
2388 node_types: RefCell::new(FnvHashMap::new()),
2389 item_substs: RefCell::new(NodeMap::new()),
2390 trait_refs: RefCell::new(NodeMap::new()),
2391 trait_defs: RefCell::new(DefIdMap::new()),
2392 object_cast_map: RefCell::new(NodeMap::new()),
2394 intrinsic_defs: RefCell::new(DefIdMap::new()),
2396 tcache: RefCell::new(DefIdMap::new()),
2397 rcache: RefCell::new(FnvHashMap::new()),
2398 short_names_cache: RefCell::new(FnvHashMap::new()),
2399 tc_cache: RefCell::new(FnvHashMap::new()),
2400 ast_ty_to_ty_cache: RefCell::new(NodeMap::new()),
2401 enum_var_cache: RefCell::new(DefIdMap::new()),
2402 impl_or_trait_items: RefCell::new(DefIdMap::new()),
2403 trait_item_def_ids: RefCell::new(DefIdMap::new()),
2404 trait_items_cache: RefCell::new(DefIdMap::new()),
2405 impl_trait_cache: RefCell::new(DefIdMap::new()),
2406 ty_param_defs: RefCell::new(NodeMap::new()),
2407 adjustments: RefCell::new(NodeMap::new()),
2408 normalized_cache: RefCell::new(FnvHashMap::new()),
2409 lang_items: lang_items,
2410 provided_method_sources: RefCell::new(DefIdMap::new()),
2411 struct_fields: RefCell::new(DefIdMap::new()),
2412 destructor_for_type: RefCell::new(DefIdMap::new()),
2413 destructors: RefCell::new(DefIdSet::new()),
2414 trait_impls: RefCell::new(DefIdMap::new()),
2415 inherent_impls: RefCell::new(DefIdMap::new()),
2416 impl_items: RefCell::new(DefIdMap::new()),
2417 used_unsafe: RefCell::new(NodeSet::new()),
2418 used_mut_nodes: RefCell::new(NodeSet::new()),
2419 populated_external_types: RefCell::new(DefIdSet::new()),
2420 populated_external_traits: RefCell::new(DefIdSet::new()),
2421 upvar_borrow_map: RefCell::new(FnvHashMap::new()),
2422 extern_const_statics: RefCell::new(DefIdMap::new()),
2423 extern_const_variants: RefCell::new(DefIdMap::new()),
2424 method_map: RefCell::new(FnvHashMap::new()),
2425 dependency_formats: RefCell::new(FnvHashMap::new()),
2426 unboxed_closures: RefCell::new(DefIdMap::new()),
2427 node_lint_levels: RefCell::new(FnvHashMap::new()),
2428 transmute_restrictions: RefCell::new(Vec::new()),
2429 stability: RefCell::new(stability),
2430 capture_modes: capture_modes,
2431 associated_types: RefCell::new(DefIdMap::new()),
2432 selection_cache: traits::SelectionCache::new(),
2433 repr_hint_cache: RefCell::new(DefIdMap::new()),
2434 type_impls_copy_cache: RefCell::new(HashMap::new()),
2435 type_impls_sized_cache: RefCell::new(HashMap::new()),
2436 object_safety_cache: RefCell::new(DefIdMap::new()),
2440 // Type constructors
2442 impl<'tcx> ctxt<'tcx> {
2443 pub fn mk_substs(&self, substs: Substs<'tcx>) -> &'tcx Substs<'tcx> {
2444 if let Some(substs) = self.substs_interner.borrow().get(&substs) {
2448 let substs = self.arenas.substs.alloc(substs);
2449 self.substs_interner.borrow_mut().insert(substs, substs);
2453 pub fn mk_bare_fn(&self, bare_fn: BareFnTy<'tcx>) -> &'tcx BareFnTy<'tcx> {
2454 if let Some(bare_fn) = self.bare_fn_interner.borrow().get(&bare_fn) {
2458 let bare_fn = self.arenas.bare_fn.alloc(bare_fn);
2459 self.bare_fn_interner.borrow_mut().insert(bare_fn, bare_fn);
2463 pub fn mk_region(&self, region: Region) -> &'tcx Region {
2464 if let Some(region) = self.region_interner.borrow().get(®ion) {
2468 let region = self.arenas.region.alloc(region);
2469 self.region_interner.borrow_mut().insert(region, region);
2473 pub fn unboxed_closure_kind(&self,
2475 -> ty::UnboxedClosureKind
2477 self.unboxed_closures.borrow()[def_id].kind
2480 pub fn unboxed_closure_type(&self,
2482 substs: &subst::Substs<'tcx>)
2483 -> ty::ClosureTy<'tcx>
2485 self.unboxed_closures.borrow()[def_id].closure_type.subst(self, substs)
2489 // Interns a type/name combination, stores the resulting box in cx.interner,
2490 // and returns the box as cast to an unsafe ptr (see comments for Ty above).
2491 pub fn mk_t<'tcx>(cx: &ctxt<'tcx>, st: sty<'tcx>) -> Ty<'tcx> {
2492 let mut interner = cx.interner.borrow_mut();
2493 intern_ty(&cx.arenas.type_, &mut *interner, st)
2496 fn intern_ty<'tcx>(type_arena: &'tcx TypedArena<TyS<'tcx>>,
2497 interner: &mut FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>,
2501 match interner.get(&st) {
2502 Some(ty) => return *ty,
2506 let flags = FlagComputation::for_sty(&st);
2508 let ty = type_arena.alloc(TyS {
2511 region_depth: flags.depth,
2514 debug!("Interned type: {:?} Pointer: {:?}",
2515 ty, ty as *const _);
2517 interner.insert(InternedTy { ty: ty }, ty);
2522 struct FlagComputation {
2525 // maximum depth of any bound region that we have seen thus far
2529 impl FlagComputation {
2530 fn new() -> FlagComputation {
2531 FlagComputation { flags: NO_TYPE_FLAGS, depth: 0 }
2534 fn for_sty(st: &sty) -> FlagComputation {
2535 let mut result = FlagComputation::new();
2540 fn add_flags(&mut self, flags: TypeFlags) {
2541 self.flags = self.flags | flags;
2544 fn add_depth(&mut self, depth: u32) {
2545 if depth > self.depth {
2550 /// Adds the flags/depth from a set of types that appear within the current type, but within a
2552 fn add_bound_computation(&mut self, computation: &FlagComputation) {
2553 self.add_flags(computation.flags);
2555 // The types that contributed to `computation` occured within
2556 // a region binder, so subtract one from the region depth
2557 // within when adding the depth to `self`.
2558 let depth = computation.depth;
2560 self.add_depth(depth - 1);
2564 fn add_sty(&mut self, st: &sty) {
2574 // You might think that we could just return ty_err for
2575 // any type containing ty_err as a component, and get
2576 // rid of the HAS_TY_ERR flag -- likewise for ty_bot (with
2577 // the exception of function types that return bot).
2578 // But doing so caused sporadic memory corruption, and
2579 // neither I (tjc) nor nmatsakis could figure out why,
2580 // so we're doing it this way.
2582 self.add_flags(HAS_TY_ERR)
2585 &ty_param(ref p) => {
2586 if p.space == subst::SelfSpace {
2587 self.add_flags(HAS_SELF);
2589 self.add_flags(HAS_PARAMS);
2593 &ty_unboxed_closure(_, region, substs) => {
2594 self.add_region(*region);
2595 self.add_substs(substs);
2599 self.add_flags(HAS_TY_INFER)
2602 &ty_enum(_, substs) | &ty_struct(_, substs) => {
2603 self.add_substs(substs);
2606 &ty_projection(ref data) => {
2607 self.add_flags(HAS_PROJECTION);
2608 self.add_substs(data.trait_ref.substs);
2611 &ty_trait(box TyTrait { ref principal, ref bounds }) => {
2612 let mut computation = FlagComputation::new();
2613 computation.add_substs(principal.0.substs);
2614 self.add_bound_computation(&computation);
2616 self.add_bounds(bounds);
2619 &ty_uniq(tt) | &ty_vec(tt, _) | &ty_open(tt) => {
2627 &ty_rptr(r, ref m) => {
2628 self.add_region(*r);
2632 &ty_tup(ref ts) => {
2633 self.add_tys(&ts[]);
2636 &ty_bare_fn(_, ref f) => {
2637 self.add_fn_sig(&f.sig);
2642 fn add_ty(&mut self, ty: Ty) {
2643 self.add_flags(ty.flags);
2644 self.add_depth(ty.region_depth);
2647 fn add_tys(&mut self, tys: &[Ty]) {
2648 for &ty in tys.iter() {
2653 fn add_fn_sig(&mut self, fn_sig: &PolyFnSig) {
2654 let mut computation = FlagComputation::new();
2656 computation.add_tys(&fn_sig.0.inputs[]);
2658 if let ty::FnConverging(output) = fn_sig.0.output {
2659 computation.add_ty(output);
2662 self.add_bound_computation(&computation);
2665 fn add_region(&mut self, r: Region) {
2666 self.add_flags(HAS_REGIONS);
2668 ty::ReInfer(_) => { self.add_flags(HAS_RE_INFER); }
2669 ty::ReLateBound(debruijn, _) => {
2670 self.add_flags(HAS_RE_LATE_BOUND);
2671 self.add_depth(debruijn.depth);
2677 fn add_substs(&mut self, substs: &Substs) {
2678 self.add_tys(substs.types.as_slice());
2679 match substs.regions {
2680 subst::ErasedRegions => {}
2681 subst::NonerasedRegions(ref regions) => {
2682 for &r in regions.iter() {
2689 fn add_bounds(&mut self, bounds: &ExistentialBounds) {
2690 self.add_region(bounds.region_bound);
2694 pub fn mk_mach_int<'tcx>(tcx: &ctxt<'tcx>, tm: ast::IntTy) -> Ty<'tcx> {
2696 ast::TyIs(_) => tcx.types.int,
2697 ast::TyI8 => tcx.types.i8,
2698 ast::TyI16 => tcx.types.i16,
2699 ast::TyI32 => tcx.types.i32,
2700 ast::TyI64 => tcx.types.i64,
2704 pub fn mk_mach_uint<'tcx>(tcx: &ctxt<'tcx>, tm: ast::UintTy) -> Ty<'tcx> {
2706 ast::TyUs(_) => tcx.types.uint,
2707 ast::TyU8 => tcx.types.u8,
2708 ast::TyU16 => tcx.types.u16,
2709 ast::TyU32 => tcx.types.u32,
2710 ast::TyU64 => tcx.types.u64,
2714 pub fn mk_mach_float<'tcx>(tcx: &ctxt<'tcx>, tm: ast::FloatTy) -> Ty<'tcx> {
2716 ast::TyF32 => tcx.types.f32,
2717 ast::TyF64 => tcx.types.f64,
2721 pub fn mk_str<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2725 pub fn mk_str_slice<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, m: ast::Mutability) -> Ty<'tcx> {
2728 ty: mk_t(cx, ty_str),
2733 pub fn mk_enum<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId, substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
2734 // take a copy of substs so that we own the vectors inside
2735 mk_t(cx, ty_enum(did, substs))
2738 pub fn mk_uniq<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_uniq(ty)) }
2740 pub fn mk_ptr<'tcx>(cx: &ctxt<'tcx>, tm: mt<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_ptr(tm)) }
2742 pub fn mk_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, tm: mt<'tcx>) -> Ty<'tcx> {
2743 mk_t(cx, ty_rptr(r, tm))
2746 pub fn mk_mut_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
2747 mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutMutable})
2749 pub fn mk_imm_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
2750 mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutImmutable})
2753 pub fn mk_mut_ptr<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
2754 mk_ptr(cx, mt {ty: ty, mutbl: ast::MutMutable})
2757 pub fn mk_imm_ptr<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
2758 mk_ptr(cx, mt {ty: ty, mutbl: ast::MutImmutable})
2761 pub fn mk_nil_ptr<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2762 mk_ptr(cx, mt {ty: mk_nil(cx), mutbl: ast::MutImmutable})
2765 pub fn mk_vec<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>, sz: Option<uint>) -> Ty<'tcx> {
2766 mk_t(cx, ty_vec(ty, sz))
2769 pub fn mk_slice<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, tm: mt<'tcx>) -> Ty<'tcx> {
2772 ty: mk_vec(cx, tm.ty, None),
2777 pub fn mk_tup<'tcx>(cx: &ctxt<'tcx>, ts: Vec<Ty<'tcx>>) -> Ty<'tcx> {
2778 mk_t(cx, ty_tup(ts))
2781 pub fn mk_nil<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2782 mk_tup(cx, Vec::new())
2785 pub fn mk_bare_fn<'tcx>(cx: &ctxt<'tcx>,
2786 opt_def_id: Option<ast::DefId>,
2787 fty: &'tcx BareFnTy<'tcx>) -> Ty<'tcx> {
2788 mk_t(cx, ty_bare_fn(opt_def_id, fty))
2791 pub fn mk_ctor_fn<'tcx>(cx: &ctxt<'tcx>,
2793 input_tys: &[Ty<'tcx>],
2794 output: Ty<'tcx>) -> Ty<'tcx> {
2795 let input_args = input_tys.iter().map(|ty| *ty).collect();
2798 cx.mk_bare_fn(BareFnTy {
2799 unsafety: ast::Unsafety::Normal,
2801 sig: ty::Binder(FnSig {
2803 output: ty::FnConverging(output),
2809 pub fn mk_trait<'tcx>(cx: &ctxt<'tcx>,
2810 principal: ty::PolyTraitRef<'tcx>,
2811 bounds: ExistentialBounds<'tcx>)
2814 assert!(bound_list_is_sorted(bounds.projection_bounds.as_slice()));
2816 let inner = box TyTrait {
2817 principal: principal,
2820 mk_t(cx, ty_trait(inner))
2823 fn bound_list_is_sorted(bounds: &[ty::PolyProjectionPredicate]) -> bool {
2824 bounds.len() == 0 ||
2825 bounds[1..].iter().enumerate().all(
2826 |(index, bound)| bounds[index].sort_key() <= bound.sort_key())
2829 pub fn sort_bounds_list(bounds: &mut [ty::PolyProjectionPredicate]) {
2830 bounds.sort_by(|a, b| a.sort_key().cmp(&b.sort_key()))
2833 pub fn mk_projection<'tcx>(cx: &ctxt<'tcx>,
2834 trait_ref: Rc<ty::TraitRef<'tcx>>,
2835 item_name: ast::Name)
2837 // take a copy of substs so that we own the vectors inside
2838 let inner = ProjectionTy { trait_ref: trait_ref, item_name: item_name };
2839 mk_t(cx, ty_projection(inner))
2842 pub fn mk_struct<'tcx>(cx: &ctxt<'tcx>, struct_id: ast::DefId,
2843 substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
2844 // take a copy of substs so that we own the vectors inside
2845 mk_t(cx, ty_struct(struct_id, substs))
2848 pub fn mk_unboxed_closure<'tcx>(cx: &ctxt<'tcx>, closure_id: ast::DefId,
2849 region: &'tcx Region, substs: &'tcx Substs<'tcx>)
2851 mk_t(cx, ty_unboxed_closure(closure_id, region, substs))
2854 pub fn mk_var<'tcx>(cx: &ctxt<'tcx>, v: TyVid) -> Ty<'tcx> {
2855 mk_infer(cx, TyVar(v))
2858 pub fn mk_int_var<'tcx>(cx: &ctxt<'tcx>, v: IntVid) -> Ty<'tcx> {
2859 mk_infer(cx, IntVar(v))
2862 pub fn mk_float_var<'tcx>(cx: &ctxt<'tcx>, v: FloatVid) -> Ty<'tcx> {
2863 mk_infer(cx, FloatVar(v))
2866 pub fn mk_infer<'tcx>(cx: &ctxt<'tcx>, it: InferTy) -> Ty<'tcx> {
2867 mk_t(cx, ty_infer(it))
2870 pub fn mk_param<'tcx>(cx: &ctxt<'tcx>,
2871 space: subst::ParamSpace,
2873 name: ast::Name) -> Ty<'tcx> {
2874 mk_t(cx, ty_param(ParamTy { space: space, idx: index, name: name }))
2877 pub fn mk_self_type<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2878 mk_param(cx, subst::SelfSpace, 0, special_idents::type_self.name)
2881 pub fn mk_param_from_def<'tcx>(cx: &ctxt<'tcx>, def: &TypeParameterDef) -> Ty<'tcx> {
2882 mk_param(cx, def.space, def.index, def.name)
2885 pub fn mk_open<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_open(ty)) }
2887 impl<'tcx> TyS<'tcx> {
2888 /// Iterator that walks `self` and any types reachable from
2889 /// `self`, in depth-first order. Note that just walks the types
2890 /// that appear in `self`, it does not descend into the fields of
2891 /// structs or variants. For example:
2895 /// Foo<Bar<int>> => { Foo<Bar<int>>, Bar<int>, int }
2896 /// [int] => { [int], int }
2898 pub fn walk(&'tcx self) -> TypeWalker<'tcx> {
2899 TypeWalker::new(self)
2902 /// Iterator that walks types reachable from `self`, in
2903 /// depth-first order. Note that this is a shallow walk. For
2908 /// Foo<Bar<int>> => { Bar<int>, int }
2909 /// [int] => { int }
2911 pub fn walk_children(&'tcx self) -> TypeWalker<'tcx> {
2912 // Walks type reachable from `self` but not `self
2913 let mut walker = self.walk();
2914 let r = walker.next();
2915 assert_eq!(r, Some(self));
2920 pub fn walk_ty<'tcx, F>(ty_root: Ty<'tcx>, mut f: F)
2921 where F: FnMut(Ty<'tcx>),
2923 for ty in ty_root.walk() {
2928 /// Walks `ty` and any types appearing within `ty`, invoking the
2929 /// callback `f` on each type. If the callback returns false, then the
2930 /// children of the current type are ignored.
2932 /// Note: prefer `ty.walk()` where possible.
2933 pub fn maybe_walk_ty<'tcx,F>(ty_root: Ty<'tcx>, mut f: F)
2934 where F : FnMut(Ty<'tcx>) -> bool
2936 let mut walker = ty_root.walk();
2937 while let Some(ty) = walker.next() {
2939 walker.skip_current_subtree();
2944 // Folds types from the bottom up.
2945 pub fn fold_ty<'tcx, F>(cx: &ctxt<'tcx>, t0: Ty<'tcx>,
2948 F: FnMut(Ty<'tcx>) -> Ty<'tcx>,
2950 let mut f = ty_fold::BottomUpFolder {tcx: cx, fldop: fldop};
2955 pub fn new(space: subst::ParamSpace,
2959 ParamTy { space: space, idx: index, name: name }
2962 pub fn for_self() -> ParamTy {
2963 ParamTy::new(subst::SelfSpace, 0, special_idents::type_self.name)
2966 pub fn for_def(def: &TypeParameterDef) -> ParamTy {
2967 ParamTy::new(def.space, def.index, def.name)
2970 pub fn to_ty<'tcx>(self, tcx: &ty::ctxt<'tcx>) -> Ty<'tcx> {
2971 ty::mk_param(tcx, self.space, self.idx, self.name)
2974 pub fn is_self(&self) -> bool {
2975 self.space == subst::SelfSpace && self.idx == 0
2979 impl<'tcx> ItemSubsts<'tcx> {
2980 pub fn empty() -> ItemSubsts<'tcx> {
2981 ItemSubsts { substs: Substs::empty() }
2984 pub fn is_noop(&self) -> bool {
2985 self.substs.is_noop()
2989 impl<'tcx> ParamBounds<'tcx> {
2990 pub fn empty() -> ParamBounds<'tcx> {
2992 builtin_bounds: empty_builtin_bounds(),
2993 trait_bounds: Vec::new(),
2994 region_bounds: Vec::new(),
2995 projection_bounds: Vec::new(),
3002 pub fn type_is_nil(ty: Ty) -> bool {
3004 ty_tup(ref tys) => tys.is_empty(),
3009 pub fn type_is_error(ty: Ty) -> bool {
3010 ty.flags.intersects(HAS_TY_ERR)
3013 pub fn type_needs_subst(ty: Ty) -> bool {
3014 ty.flags.intersects(NEEDS_SUBST)
3017 pub fn trait_ref_contains_error(tref: &ty::TraitRef) -> bool {
3018 tref.substs.types.any(|&ty| type_is_error(ty))
3021 pub fn type_is_ty_var(ty: Ty) -> bool {
3023 ty_infer(TyVar(_)) => true,
3028 pub fn type_is_bool(ty: Ty) -> bool { ty.sty == ty_bool }
3030 pub fn type_is_self(ty: Ty) -> bool {
3032 ty_param(ref p) => p.space == subst::SelfSpace,
3037 fn type_is_slice(ty: Ty) -> bool {
3039 ty_ptr(mt) | ty_rptr(_, mt) => match mt.ty.sty {
3040 ty_vec(_, None) | ty_str => true,
3047 pub fn type_is_vec(ty: Ty) -> bool {
3050 ty_ptr(mt{ty, ..}) | ty_rptr(_, mt{ty, ..}) |
3051 ty_uniq(ty) => match ty.sty {
3052 ty_vec(_, None) => true,
3059 pub fn type_is_structural(ty: Ty) -> bool {
3061 ty_struct(..) | ty_tup(_) | ty_enum(..) |
3062 ty_vec(_, Some(_)) | ty_unboxed_closure(..) => true,
3063 _ => type_is_slice(ty) | type_is_trait(ty)
3067 pub fn type_is_simd(cx: &ctxt, ty: Ty) -> bool {
3069 ty_struct(did, _) => lookup_simd(cx, did),
3074 pub fn sequence_element_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
3076 ty_vec(ty, _) => ty,
3077 ty_str => mk_mach_uint(cx, ast::TyU8),
3078 ty_open(ty) => sequence_element_type(cx, ty),
3079 _ => cx.sess.bug(&format!("sequence_element_type called on non-sequence value: {}",
3080 ty_to_string(cx, ty))[]),
3084 pub fn simd_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
3086 ty_struct(did, substs) => {
3087 let fields = lookup_struct_fields(cx, did);
3088 lookup_field_type(cx, did, fields[0].id, substs)
3090 _ => panic!("simd_type called on invalid type")
3094 pub fn simd_size(cx: &ctxt, ty: Ty) -> uint {
3096 ty_struct(did, _) => {
3097 let fields = lookup_struct_fields(cx, did);
3100 _ => panic!("simd_size called on invalid type")
3104 pub fn type_is_region_ptr(ty: Ty) -> bool {
3106 ty_rptr(..) => true,
3111 pub fn type_is_unsafe_ptr(ty: Ty) -> bool {
3113 ty_ptr(_) => return true,
3118 pub fn type_is_unique(ty: Ty) -> bool {
3120 ty_uniq(_) => match ty.sty {
3121 ty_trait(..) => false,
3129 A scalar type is one that denotes an atomic datum, with no sub-components.
3130 (A ty_ptr is scalar because it represents a non-managed pointer, so its
3131 contents are abstract to rustc.)
3133 pub fn type_is_scalar(ty: Ty) -> bool {
3135 ty_bool | ty_char | ty_int(_) | ty_float(_) | ty_uint(_) |
3136 ty_infer(IntVar(_)) | ty_infer(FloatVar(_)) |
3137 ty_bare_fn(..) | ty_ptr(_) => true,
3138 ty_tup(ref tys) if tys.is_empty() => true,
3143 /// Returns true if this type is a floating point type and false otherwise.
3144 pub fn type_is_floating_point(ty: Ty) -> bool {
3146 ty_float(_) => true,
3151 /// Type contents is how the type checker reasons about kinds.
3152 /// They track what kinds of things are found within a type. You can
3153 /// think of them as kind of an "anti-kind". They track the kinds of values
3154 /// and thinks that are contained in types. Having a larger contents for
3155 /// a type tends to rule that type *out* from various kinds. For example,
3156 /// a type that contains a reference is not sendable.
3158 /// The reason we compute type contents and not kinds is that it is
3159 /// easier for me (nmatsakis) to think about what is contained within
3160 /// a type than to think about what is *not* contained within a type.
3161 #[derive(Clone, Copy)]
3162 pub struct TypeContents {
3166 macro_rules! def_type_content_sets {
3167 (mod $mname:ident { $($name:ident = $bits:expr),+ }) => {
3168 #[allow(non_snake_case)]
3170 use middle::ty::TypeContents;
3172 #[allow(non_upper_case_globals)]
3173 pub const $name: TypeContents = TypeContents { bits: $bits };
3179 def_type_content_sets! {
3181 None = 0b0000_0000__0000_0000__0000,
3183 // Things that are interior to the value (first nibble):
3184 InteriorUnsized = 0b0000_0000__0000_0000__0001,
3185 InteriorUnsafe = 0b0000_0000__0000_0000__0010,
3186 InteriorParam = 0b0000_0000__0000_0000__0100,
3187 // InteriorAll = 0b00000000__00000000__1111,
3189 // Things that are owned by the value (second and third nibbles):
3190 OwnsOwned = 0b0000_0000__0000_0001__0000,
3191 OwnsDtor = 0b0000_0000__0000_0010__0000,
3192 OwnsManaged /* see [1] below */ = 0b0000_0000__0000_0100__0000,
3193 OwnsAll = 0b0000_0000__1111_1111__0000,
3195 // Things that are reachable by the value in any way (fourth nibble):
3196 ReachesBorrowed = 0b0000_0010__0000_0000__0000,
3197 // ReachesManaged /* see [1] below */ = 0b0000_0100__0000_0000__0000,
3198 ReachesMutable = 0b0000_1000__0000_0000__0000,
3199 ReachesFfiUnsafe = 0b0010_0000__0000_0000__0000,
3200 ReachesAll = 0b0011_1111__0000_0000__0000,
3202 // Things that mean drop glue is necessary
3203 NeedsDrop = 0b0000_0000__0000_0111__0000,
3205 // Things that prevent values from being considered sized
3206 Nonsized = 0b0000_0000__0000_0000__0001,
3208 // Bits to set when a managed value is encountered
3210 // [1] Do not set the bits TC::OwnsManaged or
3211 // TC::ReachesManaged directly, instead reference
3212 // TC::Managed to set them both at once.
3213 Managed = 0b0000_0100__0000_0100__0000,
3216 All = 0b1111_1111__1111_1111__1111
3221 pub fn when(&self, cond: bool) -> TypeContents {
3222 if cond {*self} else {TC::None}
3225 pub fn intersects(&self, tc: TypeContents) -> bool {
3226 (self.bits & tc.bits) != 0
3229 pub fn owns_managed(&self) -> bool {
3230 self.intersects(TC::OwnsManaged)
3233 pub fn owns_owned(&self) -> bool {
3234 self.intersects(TC::OwnsOwned)
3237 pub fn is_sized(&self, _: &ctxt) -> bool {
3238 !self.intersects(TC::Nonsized)
3241 pub fn interior_param(&self) -> bool {
3242 self.intersects(TC::InteriorParam)
3245 pub fn interior_unsafe(&self) -> bool {
3246 self.intersects(TC::InteriorUnsafe)
3249 pub fn interior_unsized(&self) -> bool {
3250 self.intersects(TC::InteriorUnsized)
3253 pub fn needs_drop(&self, _: &ctxt) -> bool {
3254 self.intersects(TC::NeedsDrop)
3257 /// Includes only those bits that still apply when indirected through a `Box` pointer
3258 pub fn owned_pointer(&self) -> TypeContents {
3260 *self & (TC::OwnsAll | TC::ReachesAll))
3263 /// Includes only those bits that still apply when indirected through a reference (`&`)
3264 pub fn reference(&self, bits: TypeContents) -> TypeContents {
3266 *self & TC::ReachesAll)
3269 /// Includes only those bits that still apply when indirected through a managed pointer (`@`)
3270 pub fn managed_pointer(&self) -> TypeContents {
3272 *self & TC::ReachesAll)
3275 /// Includes only those bits that still apply when indirected through an unsafe pointer (`*`)
3276 pub fn unsafe_pointer(&self) -> TypeContents {
3277 *self & TC::ReachesAll
3280 pub fn union<T, F>(v: &[T], mut f: F) -> TypeContents where
3281 F: FnMut(&T) -> TypeContents,
3283 v.iter().fold(TC::None, |tc, ty| tc | f(ty))
3286 pub fn has_dtor(&self) -> bool {
3287 self.intersects(TC::OwnsDtor)
3291 impl ops::BitOr for TypeContents {
3292 type Output = TypeContents;
3294 fn bitor(self, other: TypeContents) -> TypeContents {
3295 TypeContents {bits: self.bits | other.bits}
3299 impl ops::BitAnd for TypeContents {
3300 type Output = TypeContents;
3302 fn bitand(self, other: TypeContents) -> TypeContents {
3303 TypeContents {bits: self.bits & other.bits}
3307 impl ops::Sub for TypeContents {
3308 type Output = TypeContents;
3310 fn sub(self, other: TypeContents) -> TypeContents {
3311 TypeContents {bits: self.bits & !other.bits}
3315 impl fmt::Show for TypeContents {
3316 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
3317 write!(f, "TypeContents({:b})", self.bits)
3321 pub fn type_interior_is_unsafe<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
3322 type_contents(cx, ty).interior_unsafe()
3325 pub fn type_contents<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> TypeContents {
3326 return memoized(&cx.tc_cache, ty, |ty| {
3327 tc_ty(cx, ty, &mut FnvHashMap::new())
3330 fn tc_ty<'tcx>(cx: &ctxt<'tcx>,
3332 cache: &mut FnvHashMap<Ty<'tcx>, TypeContents>) -> TypeContents
3334 // Subtle: Note that we are *not* using cx.tc_cache here but rather a
3335 // private cache for this walk. This is needed in the case of cyclic
3338 // struct List { next: Box<Option<List>>, ... }
3340 // When computing the type contents of such a type, we wind up deeply
3341 // recursing as we go. So when we encounter the recursive reference
3342 // to List, we temporarily use TC::None as its contents. Later we'll
3343 // patch up the cache with the correct value, once we've computed it
3344 // (this is basically a co-inductive process, if that helps). So in
3345 // the end we'll compute TC::OwnsOwned, in this case.
3347 // The problem is, as we are doing the computation, we will also
3348 // compute an *intermediate* contents for, e.g., Option<List> of
3349 // TC::None. This is ok during the computation of List itself, but if
3350 // we stored this intermediate value into cx.tc_cache, then later
3351 // requests for the contents of Option<List> would also yield TC::None
3352 // which is incorrect. This value was computed based on the crutch
3353 // value for the type contents of list. The correct value is
3354 // TC::OwnsOwned. This manifested as issue #4821.
3355 match cache.get(&ty) {
3356 Some(tc) => { return *tc; }
3359 match cx.tc_cache.borrow().get(&ty) { // Must check both caches!
3360 Some(tc) => { return *tc; }
3363 cache.insert(ty, TC::None);
3365 let result = match ty.sty {
3366 // uint and int are ffi-unsafe
3367 ty_uint(ast::TyUs(_)) | ty_int(ast::TyIs(_)) => {
3368 TC::ReachesFfiUnsafe
3371 // Scalar and unique types are sendable, and durable
3372 ty_infer(ty::FreshIntTy(_)) |
3373 ty_bool | ty_int(_) | ty_uint(_) | ty_float(_) |
3374 ty_bare_fn(..) | ty::ty_char => {
3379 TC::ReachesFfiUnsafe | match typ.sty {
3380 ty_str => TC::OwnsOwned,
3381 _ => tc_ty(cx, typ, cache).owned_pointer(),
3385 ty_trait(box TyTrait { ref bounds, .. }) => {
3386 object_contents(bounds) | TC::ReachesFfiUnsafe | TC::Nonsized
3390 tc_ty(cx, mt.ty, cache).unsafe_pointer()
3393 ty_rptr(r, ref mt) => {
3394 TC::ReachesFfiUnsafe | match mt.ty.sty {
3395 ty_str => borrowed_contents(*r, ast::MutImmutable),
3396 ty_vec(..) => tc_ty(cx, mt.ty, cache).reference(borrowed_contents(*r,
3398 _ => tc_ty(cx, mt.ty, cache).reference(borrowed_contents(*r, mt.mutbl)),
3402 ty_vec(ty, Some(_)) => {
3403 tc_ty(cx, ty, cache)
3406 ty_vec(ty, None) => {
3407 tc_ty(cx, ty, cache) | TC::Nonsized
3409 ty_str => TC::Nonsized,
3411 ty_struct(did, substs) => {
3412 let flds = struct_fields(cx, did, substs);
3414 TypeContents::union(&flds[],
3415 |f| tc_mt(cx, f.mt, cache));
3417 if !lookup_repr_hints(cx, did).contains(&attr::ReprExtern) {
3418 res = res | TC::ReachesFfiUnsafe;
3421 if ty::has_dtor(cx, did) {
3422 res = res | TC::OwnsDtor;
3424 apply_lang_items(cx, did, res)
3427 ty_unboxed_closure(did, r, substs) => {
3428 // FIXME(#14449): `borrowed_contents` below assumes `&mut`
3430 let param_env = ty::empty_parameter_environment(cx);
3431 let upvars = unboxed_closure_upvars(¶m_env, did, substs).unwrap();
3432 TypeContents::union(upvars.as_slice(),
3433 |f| tc_ty(cx, f.ty, cache))
3434 | borrowed_contents(*r, MutMutable)
3437 ty_tup(ref tys) => {
3438 TypeContents::union(&tys[],
3439 |ty| tc_ty(cx, *ty, cache))
3442 ty_enum(did, substs) => {
3443 let variants = substd_enum_variants(cx, did, substs);
3445 TypeContents::union(&variants[], |variant| {
3446 TypeContents::union(&variant.args[],
3448 tc_ty(cx, *arg_ty, cache)
3452 if ty::has_dtor(cx, did) {
3453 res = res | TC::OwnsDtor;
3456 if variants.len() != 0 {
3457 let repr_hints = lookup_repr_hints(cx, did);
3458 if repr_hints.len() > 1 {
3459 // this is an error later on, but this type isn't safe
3460 res = res | TC::ReachesFfiUnsafe;
3463 match repr_hints.get(0) {
3464 Some(h) => if !h.is_ffi_safe() {
3465 res = res | TC::ReachesFfiUnsafe;
3469 res = res | TC::ReachesFfiUnsafe;
3471 // We allow ReprAny enums if they are eligible for
3472 // the nullable pointer optimization and the
3473 // contained type is an `extern fn`
3475 if variants.len() == 2 {
3476 let mut data_idx = 0;
3478 if variants[0].args.len() == 0 {
3482 if variants[data_idx].args.len() == 1 {
3483 match variants[data_idx].args[0].sty {
3484 ty_bare_fn(..) => { res = res - TC::ReachesFfiUnsafe; }
3494 apply_lang_items(cx, did, res)
3503 let result = tc_ty(cx, ty, cache);
3504 assert!(!result.is_sized(cx));
3505 result.unsafe_pointer() | TC::Nonsized
3510 cx.sess.bug("asked to compute contents of error type");
3514 cache.insert(ty, result);
3518 fn tc_mt<'tcx>(cx: &ctxt<'tcx>,
3520 cache: &mut FnvHashMap<Ty<'tcx>, TypeContents>) -> TypeContents
3522 let mc = TC::ReachesMutable.when(mt.mutbl == MutMutable);
3523 mc | tc_ty(cx, mt.ty, cache)
3526 fn apply_lang_items(cx: &ctxt, did: ast::DefId, tc: TypeContents)
3528 if Some(did) == cx.lang_items.managed_bound() {
3530 } else if Some(did) == cx.lang_items.unsafe_type() {
3531 tc | TC::InteriorUnsafe
3537 /// Type contents due to containing a reference with the region `region` and borrow kind `bk`
3538 fn borrowed_contents(region: ty::Region,
3539 mutbl: ast::Mutability)
3541 let b = match mutbl {
3542 ast::MutMutable => TC::ReachesMutable,
3543 ast::MutImmutable => TC::None,
3545 b | (TC::ReachesBorrowed).when(region != ty::ReStatic)
3548 fn object_contents(bounds: &ExistentialBounds) -> TypeContents {
3549 // These are the type contents of the (opaque) interior. We
3550 // make no assumptions (other than that it cannot have an
3551 // in-scope type parameter within, which makes no sense).
3552 let mut tc = TC::All - TC::InteriorParam;
3553 for bound in bounds.builtin_bounds.iter() {
3554 tc = tc - match bound {
3555 BoundSync | BoundSend | BoundCopy => TC::None,
3556 BoundSized => TC::Nonsized,
3563 fn type_impls_bound<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3564 cache: &RefCell<HashMap<Ty<'tcx>,bool>>,
3566 bound: ty::BuiltinBound,
3570 assert!(!ty::type_needs_infer(ty));
3572 if !type_has_params(ty) && !type_has_self(ty) {
3573 match cache.borrow().get(&ty) {
3576 debug!("type_impls_bound({}, {:?}) = {:?} (cached)",
3577 ty.repr(param_env.tcx),
3585 let infcx = infer::new_infer_ctxt(param_env.tcx);
3587 let is_impld = traits::type_known_to_meet_builtin_bound(&infcx, param_env, ty, bound, span);
3589 debug!("type_impls_bound({}, {:?}) = {:?}",
3590 ty.repr(param_env.tcx),
3594 if !type_has_params(ty) && !type_has_self(ty) {
3595 let old_value = cache.borrow_mut().insert(ty, is_impld);
3596 assert!(old_value.is_none());
3602 pub fn type_moves_by_default<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3607 let tcx = param_env.tcx;
3608 !type_impls_bound(param_env, &tcx.type_impls_copy_cache, ty, ty::BoundCopy, span)
3611 pub fn type_is_sized<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3616 let tcx = param_env.tcx;
3617 type_impls_bound(param_env, &tcx.type_impls_sized_cache, ty, ty::BoundSized, span)
3620 pub fn is_ffi_safe<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
3621 !type_contents(cx, ty).intersects(TC::ReachesFfiUnsafe)
3624 // True if instantiating an instance of `r_ty` requires an instance of `r_ty`.
3625 pub fn is_instantiable<'tcx>(cx: &ctxt<'tcx>, r_ty: Ty<'tcx>) -> bool {
3626 fn type_requires<'tcx>(cx: &ctxt<'tcx>, seen: &mut Vec<DefId>,
3627 r_ty: Ty<'tcx>, ty: Ty<'tcx>) -> bool {
3628 debug!("type_requires({:?}, {:?})?",
3629 ::util::ppaux::ty_to_string(cx, r_ty),
3630 ::util::ppaux::ty_to_string(cx, ty));
3632 let r = r_ty == ty || subtypes_require(cx, seen, r_ty, ty);
3634 debug!("type_requires({:?}, {:?})? {:?}",
3635 ::util::ppaux::ty_to_string(cx, r_ty),
3636 ::util::ppaux::ty_to_string(cx, ty),
3641 fn subtypes_require<'tcx>(cx: &ctxt<'tcx>, seen: &mut Vec<DefId>,
3642 r_ty: Ty<'tcx>, ty: Ty<'tcx>) -> bool {
3643 debug!("subtypes_require({:?}, {:?})?",
3644 ::util::ppaux::ty_to_string(cx, r_ty),
3645 ::util::ppaux::ty_to_string(cx, ty));
3647 let r = match ty.sty {
3648 // fixed length vectors need special treatment compared to
3649 // normal vectors, since they don't necessarily have the
3650 // possibility to have length zero.
3651 ty_vec(_, Some(0)) => false, // don't need no contents
3652 ty_vec(ty, Some(_)) => type_requires(cx, seen, r_ty, ty),
3663 ty_vec(_, None) => {
3666 ty_uniq(typ) | ty_open(typ) => {
3667 type_requires(cx, seen, r_ty, typ)
3669 ty_rptr(_, ref mt) => {
3670 type_requires(cx, seen, r_ty, mt.ty)
3674 false // unsafe ptrs can always be NULL
3681 ty_struct(ref did, _) if seen.contains(did) => {
3685 ty_struct(did, substs) => {
3687 let fields = struct_fields(cx, did, substs);
3688 let r = fields.iter().any(|f| type_requires(cx, seen, r_ty, f.mt.ty));
3689 seen.pop().unwrap();
3695 ty_unboxed_closure(..) => {
3696 // this check is run on type definitions, so we don't expect to see
3697 // inference by-products or unboxed closure types
3698 cx.sess.bug(format!("requires check invoked on inapplicable type: {:?}",
3703 ts.iter().any(|ty| type_requires(cx, seen, r_ty, *ty))
3706 ty_enum(ref did, _) if seen.contains(did) => {
3710 ty_enum(did, substs) => {
3712 let vs = enum_variants(cx, did);
3713 let r = !vs.is_empty() && vs.iter().all(|variant| {
3714 variant.args.iter().any(|aty| {
3715 let sty = aty.subst(cx, substs);
3716 type_requires(cx, seen, r_ty, sty)
3719 seen.pop().unwrap();
3724 debug!("subtypes_require({:?}, {:?})? {:?}",
3725 ::util::ppaux::ty_to_string(cx, r_ty),
3726 ::util::ppaux::ty_to_string(cx, ty),
3732 let mut seen = Vec::new();
3733 !subtypes_require(cx, &mut seen, r_ty, r_ty)
3736 /// Describes whether a type is representable. For types that are not
3737 /// representable, 'SelfRecursive' and 'ContainsRecursive' are used to
3738 /// distinguish between types that are recursive with themselves and types that
3739 /// contain a different recursive type. These cases can therefore be treated
3740 /// differently when reporting errors.
3742 /// The ordering of the cases is significant. They are sorted so that cmp::max
3743 /// will keep the "more erroneous" of two values.
3744 #[derive(Copy, PartialOrd, Ord, Eq, PartialEq, Show)]
3745 pub enum Representability {
3751 /// Check whether a type is representable. This means it cannot contain unboxed
3752 /// structural recursion. This check is needed for structs and enums.
3753 pub fn is_type_representable<'tcx>(cx: &ctxt<'tcx>, sp: Span, ty: Ty<'tcx>)
3754 -> Representability {
3756 // Iterate until something non-representable is found
3757 fn find_nonrepresentable<'tcx, It: Iterator<Item=Ty<'tcx>>>(cx: &ctxt<'tcx>, sp: Span,
3758 seen: &mut Vec<Ty<'tcx>>,
3760 -> Representability {
3761 iter.fold(Representable,
3762 |r, ty| cmp::max(r, is_type_structurally_recursive(cx, sp, seen, ty)))
3765 fn are_inner_types_recursive<'tcx>(cx: &ctxt<'tcx>, sp: Span,
3766 seen: &mut Vec<Ty<'tcx>>, ty: Ty<'tcx>)
3767 -> Representability {
3770 find_nonrepresentable(cx, sp, seen, ts.iter().map(|ty| *ty))
3772 // Fixed-length vectors.
3773 // FIXME(#11924) Behavior undecided for zero-length vectors.
3774 ty_vec(ty, Some(_)) => {
3775 is_type_structurally_recursive(cx, sp, seen, ty)
3777 ty_struct(did, substs) => {
3778 let fields = struct_fields(cx, did, substs);
3779 find_nonrepresentable(cx, sp, seen, fields.iter().map(|f| f.mt.ty))
3781 ty_enum(did, substs) => {
3782 let vs = enum_variants(cx, did);
3783 let iter = vs.iter()
3784 .flat_map(|variant| { variant.args.iter() })
3785 .map(|aty| { aty.subst_spanned(cx, substs, Some(sp)) });
3787 find_nonrepresentable(cx, sp, seen, iter)
3789 ty_unboxed_closure(..) => {
3790 // this check is run on type definitions, so we don't expect to see
3791 // unboxed closure types
3792 cx.sess.bug(format!("requires check invoked on inapplicable type: {:?}",
3799 fn same_struct_or_enum_def_id(ty: Ty, did: DefId) -> bool {
3801 ty_struct(ty_did, _) | ty_enum(ty_did, _) => {
3808 fn same_type<'tcx>(a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
3809 match (&a.sty, &b.sty) {
3810 (&ty_struct(did_a, ref substs_a), &ty_struct(did_b, ref substs_b)) |
3811 (&ty_enum(did_a, ref substs_a), &ty_enum(did_b, ref substs_b)) => {
3816 let types_a = substs_a.types.get_slice(subst::TypeSpace);
3817 let types_b = substs_b.types.get_slice(subst::TypeSpace);
3819 let pairs = types_a.iter().zip(types_b.iter());
3821 pairs.all(|(&a, &b)| same_type(a, b))
3829 // Does the type `ty` directly (without indirection through a pointer)
3830 // contain any types on stack `seen`?
3831 fn is_type_structurally_recursive<'tcx>(cx: &ctxt<'tcx>, sp: Span,
3832 seen: &mut Vec<Ty<'tcx>>,
3833 ty: Ty<'tcx>) -> Representability {
3834 debug!("is_type_structurally_recursive: {:?}",
3835 ::util::ppaux::ty_to_string(cx, ty));
3838 ty_struct(did, _) | ty_enum(did, _) => {
3840 // Iterate through stack of previously seen types.
3841 let mut iter = seen.iter();
3843 // The first item in `seen` is the type we are actually curious about.
3844 // We want to return SelfRecursive if this type contains itself.
3845 // It is important that we DON'T take generic parameters into account
3846 // for this check, so that Bar<T> in this example counts as SelfRecursive:
3849 // struct Bar<T> { x: Bar<Foo> }
3852 Some(&seen_type) => {
3853 if same_struct_or_enum_def_id(seen_type, did) {
3854 debug!("SelfRecursive: {:?} contains {:?}",
3855 ::util::ppaux::ty_to_string(cx, seen_type),
3856 ::util::ppaux::ty_to_string(cx, ty));
3857 return SelfRecursive;
3863 // We also need to know whether the first item contains other types that
3864 // are structurally recursive. If we don't catch this case, we will recurse
3865 // infinitely for some inputs.
3867 // It is important that we DO take generic parameters into account here,
3868 // so that code like this is considered SelfRecursive, not ContainsRecursive:
3870 // struct Foo { Option<Option<Foo>> }
3872 for &seen_type in iter {
3873 if same_type(ty, seen_type) {
3874 debug!("ContainsRecursive: {:?} contains {:?}",
3875 ::util::ppaux::ty_to_string(cx, seen_type),
3876 ::util::ppaux::ty_to_string(cx, ty));
3877 return ContainsRecursive;
3882 // For structs and enums, track all previously seen types by pushing them
3883 // onto the 'seen' stack.
3885 let out = are_inner_types_recursive(cx, sp, seen, ty);
3890 // No need to push in other cases.
3891 are_inner_types_recursive(cx, sp, seen, ty)
3896 debug!("is_type_representable: {:?}",
3897 ::util::ppaux::ty_to_string(cx, ty));
3899 // To avoid a stack overflow when checking an enum variant or struct that
3900 // contains a different, structurally recursive type, maintain a stack
3901 // of seen types and check recursion for each of them (issues #3008, #3779).
3902 let mut seen: Vec<Ty> = Vec::new();
3903 let r = is_type_structurally_recursive(cx, sp, &mut seen, ty);
3904 debug!("is_type_representable: {:?} is {:?}",
3905 ::util::ppaux::ty_to_string(cx, ty), r);
3909 pub fn type_is_trait(ty: Ty) -> bool {
3910 type_trait_info(ty).is_some()
3913 pub fn type_trait_info<'tcx>(ty: Ty<'tcx>) -> Option<&'tcx TyTrait<'tcx>> {
3915 ty_uniq(ty) | ty_rptr(_, mt { ty, ..}) | ty_ptr(mt { ty, ..}) => match ty.sty {
3916 ty_trait(ref t) => Some(&**t),
3919 ty_trait(ref t) => Some(&**t),
3924 pub fn type_is_integral(ty: Ty) -> bool {
3926 ty_infer(IntVar(_)) | ty_int(_) | ty_uint(_) => true,
3931 pub fn type_is_fresh(ty: Ty) -> bool {
3933 ty_infer(FreshTy(_)) => true,
3934 ty_infer(FreshIntTy(_)) => true,
3939 pub fn type_is_uint(ty: Ty) -> bool {
3941 ty_infer(IntVar(_)) | ty_uint(ast::TyUs(_)) => true,
3946 pub fn type_is_char(ty: Ty) -> bool {
3953 pub fn type_is_bare_fn(ty: Ty) -> bool {
3955 ty_bare_fn(..) => true,
3960 pub fn type_is_bare_fn_item(ty: Ty) -> bool {
3962 ty_bare_fn(Some(_), _) => true,
3967 pub fn type_is_fp(ty: Ty) -> bool {
3969 ty_infer(FloatVar(_)) | ty_float(_) => true,
3974 pub fn type_is_numeric(ty: Ty) -> bool {
3975 return type_is_integral(ty) || type_is_fp(ty);
3978 pub fn type_is_signed(ty: Ty) -> bool {
3985 pub fn type_is_machine(ty: Ty) -> bool {
3987 ty_int(ast::TyIs(_)) | ty_uint(ast::TyUs(_)) => false,
3988 ty_int(..) | ty_uint(..) | ty_float(..) => true,
3993 // Whether a type is enum like, that is an enum type with only nullary
3995 pub fn type_is_c_like_enum(cx: &ctxt, ty: Ty) -> bool {
3997 ty_enum(did, _) => {
3998 let variants = enum_variants(cx, did);
3999 if variants.len() == 0 {
4002 variants.iter().all(|v| v.args.len() == 0)
4009 // Returns the type and mutability of *ty.
4011 // The parameter `explicit` indicates if this is an *explicit* dereference.
4012 // Some types---notably unsafe ptrs---can only be dereferenced explicitly.
4013 pub fn deref<'tcx>(ty: Ty<'tcx>, explicit: bool) -> Option<mt<'tcx>> {
4018 mutbl: ast::MutImmutable,
4021 ty_rptr(_, mt) => Some(mt),
4022 ty_ptr(mt) if explicit => Some(mt),
4027 pub fn close_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
4029 ty_open(ty) => mk_rptr(cx, cx.mk_region(ReStatic), mt {ty: ty, mutbl:ast::MutImmutable}),
4030 _ => cx.sess.bug(&format!("Trying to close a non-open type {}",
4031 ty_to_string(cx, ty))[])
4035 pub fn type_content<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
4038 ty_rptr(_, mt) |ty_ptr(mt) => mt.ty,
4043 // Extract the unsized type in an open type (or just return ty if it is not open).
4044 pub fn unopen_type<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
4051 // Returns the type of ty[i]
4052 pub fn index<'tcx>(ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
4054 ty_vec(ty, _) => Some(ty),
4059 // Returns the type of elements contained within an 'array-like' type.
4060 // This is exactly the same as the above, except it supports strings,
4061 // which can't actually be indexed.
4062 pub fn array_element_ty<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
4064 ty_vec(ty, _) => Some(ty),
4065 ty_str => Some(tcx.types.u8),
4070 /// Returns the type of element at index `i` in tuple or tuple-like type `t`.
4071 /// For an enum `t`, `variant` is None only if `t` is a univariant enum.
4072 pub fn positional_element_ty<'tcx>(cx: &ctxt<'tcx>,
4075 variant: Option<ast::DefId>) -> Option<Ty<'tcx>> {
4077 match (&ty.sty, variant) {
4078 (&ty_tup(ref v), None) => v.get(i).map(|&t| t),
4081 (&ty_struct(def_id, substs), None) => lookup_struct_fields(cx, def_id)
4083 .map(|&t|lookup_item_type(cx, t.id).ty.subst(cx, substs)),
4085 (&ty_enum(def_id, substs), Some(variant_def_id)) => {
4086 let variant_info = enum_variant_with_id(cx, def_id, variant_def_id);
4087 variant_info.args.get(i).map(|t|t.subst(cx, substs))
4090 (&ty_enum(def_id, substs), None) => {
4091 assert!(enum_is_univariant(cx, def_id));
4092 let enum_variants = enum_variants(cx, def_id);
4093 let variant_info = &(*enum_variants)[0];
4094 variant_info.args.get(i).map(|t|t.subst(cx, substs))
4101 /// Returns the type of element at field `n` in struct or struct-like type `t`.
4102 /// For an enum `t`, `variant` must be some def id.
4103 pub fn named_element_ty<'tcx>(cx: &ctxt<'tcx>,
4106 variant: Option<ast::DefId>) -> Option<Ty<'tcx>> {
4108 match (&ty.sty, variant) {
4109 (&ty_struct(def_id, substs), None) => {
4110 let r = lookup_struct_fields(cx, def_id);
4111 r.iter().find(|f| f.name == n)
4112 .map(|&f| lookup_field_type(cx, def_id, f.id, substs))
4114 (&ty_enum(def_id, substs), Some(variant_def_id)) => {
4115 let variant_info = enum_variant_with_id(cx, def_id, variant_def_id);
4116 variant_info.arg_names.as_ref()
4117 .expect("must have struct enum variant if accessing a named fields")
4118 .iter().zip(variant_info.args.iter())
4119 .find(|&(ident, _)| ident.name == n)
4120 .map(|(_ident, arg_t)| arg_t.subst(cx, substs))
4126 pub fn node_id_to_trait_ref<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId)
4127 -> Rc<ty::TraitRef<'tcx>> {
4128 match cx.trait_refs.borrow().get(&id) {
4129 Some(ty) => ty.clone(),
4130 None => cx.sess.bug(
4131 &format!("node_id_to_trait_ref: no trait ref for node `{}`",
4132 cx.map.node_to_string(id))[])
4136 pub fn try_node_id_to_type<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Option<Ty<'tcx>> {
4137 cx.node_types.borrow().get(&id).cloned()
4140 pub fn node_id_to_type<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Ty<'tcx> {
4141 match try_node_id_to_type(cx, id) {
4143 None => cx.sess.bug(
4144 &format!("node_id_to_type: no type for node `{}`",
4145 cx.map.node_to_string(id))[])
4149 pub fn node_id_to_type_opt<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Option<Ty<'tcx>> {
4150 match cx.node_types.borrow().get(&id) {
4151 Some(&ty) => Some(ty),
4156 pub fn node_id_item_substs<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> ItemSubsts<'tcx> {
4157 match cx.item_substs.borrow().get(&id) {
4158 None => ItemSubsts::empty(),
4159 Some(ts) => ts.clone(),
4163 pub fn fn_is_variadic(fty: Ty) -> bool {
4165 ty_bare_fn(_, ref f) => f.sig.0.variadic,
4167 panic!("fn_is_variadic() called on non-fn type: {:?}", s)
4172 pub fn ty_fn_sig<'tcx>(fty: Ty<'tcx>) -> &'tcx PolyFnSig<'tcx> {
4174 ty_bare_fn(_, ref f) => &f.sig,
4176 panic!("ty_fn_sig() called on non-fn type: {:?}", s)
4181 /// Returns the ABI of the given function.
4182 pub fn ty_fn_abi(fty: Ty) -> abi::Abi {
4184 ty_bare_fn(_, ref f) => f.abi,
4185 _ => panic!("ty_fn_abi() called on non-fn type"),
4189 // Type accessors for substructures of types
4190 pub fn ty_fn_args<'tcx>(fty: Ty<'tcx>) -> ty::Binder<Vec<Ty<'tcx>>> {
4191 ty_fn_sig(fty).inputs()
4194 pub fn ty_closure_store(fty: Ty) -> TraitStore {
4196 ty_unboxed_closure(..) => {
4197 // Close enough for the purposes of all the callers of this
4198 // function (which is soon to be deprecated anyhow).
4202 panic!("ty_closure_store() called on non-closure type: {:?}", s)
4207 pub fn ty_fn_ret<'tcx>(fty: Ty<'tcx>) -> Binder<FnOutput<'tcx>> {
4209 ty_bare_fn(_, ref f) => f.sig.output(),
4211 panic!("ty_fn_ret() called on non-fn type: {:?}", s)
4216 pub fn is_fn_ty(fty: Ty) -> bool {
4218 ty_bare_fn(..) => true,
4223 pub fn ty_region(tcx: &ctxt,
4227 ty_rptr(r, _) => *r,
4231 &format!("ty_region() invoked on an inappropriate ty: {:?}",
4237 pub fn free_region_from_def(free_id: ast::NodeId, def: &RegionParameterDef)
4240 ty::ReFree(ty::FreeRegion { scope: region::CodeExtent::from_node_id(free_id),
4241 bound_region: ty::BrNamed(def.def_id,
4245 // Returns the type of a pattern as a monotype. Like @expr_ty, this function
4246 // doesn't provide type parameter substitutions.
4247 pub fn pat_ty<'tcx>(cx: &ctxt<'tcx>, pat: &ast::Pat) -> Ty<'tcx> {
4248 return node_id_to_type(cx, pat.id);
4252 // Returns the type of an expression as a monotype.
4254 // NB (1): This is the PRE-ADJUSTMENT TYPE for the expression. That is, in
4255 // some cases, we insert `AutoAdjustment` annotations such as auto-deref or
4256 // auto-ref. The type returned by this function does not consider such
4257 // adjustments. See `expr_ty_adjusted()` instead.
4259 // NB (2): This type doesn't provide type parameter substitutions; e.g. if you
4260 // ask for the type of "id" in "id(3)", it will return "fn(&int) -> int"
4261 // instead of "fn(ty) -> T with T = int".
4262 pub fn expr_ty<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Ty<'tcx> {
4263 return node_id_to_type(cx, expr.id);
4266 pub fn expr_ty_opt<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Option<Ty<'tcx>> {
4267 return node_id_to_type_opt(cx, expr.id);
4270 /// Returns the type of `expr`, considering any `AutoAdjustment`
4271 /// entry recorded for that expression.
4273 /// It would almost certainly be better to store the adjusted ty in with
4274 /// the `AutoAdjustment`, but I opted not to do this because it would
4275 /// require serializing and deserializing the type and, although that's not
4276 /// hard to do, I just hate that code so much I didn't want to touch it
4277 /// unless it was to fix it properly, which seemed a distraction from the
4278 /// task at hand! -nmatsakis
4279 pub fn expr_ty_adjusted<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Ty<'tcx> {
4280 adjust_ty(cx, expr.span, expr.id, expr_ty(cx, expr),
4281 cx.adjustments.borrow().get(&expr.id),
4282 |method_call| cx.method_map.borrow().get(&method_call).map(|method| method.ty))
4285 pub fn expr_span(cx: &ctxt, id: NodeId) -> Span {
4286 match cx.map.find(id) {
4287 Some(ast_map::NodeExpr(e)) => {
4291 cx.sess.bug(&format!("Node id {} is not an expr: {:?}",
4296 cx.sess.bug(&format!("Node id {} is not present \
4297 in the node map", id)[]);
4302 pub fn local_var_name_str(cx: &ctxt, id: NodeId) -> InternedString {
4303 match cx.map.find(id) {
4304 Some(ast_map::NodeLocal(pat)) => {
4306 ast::PatIdent(_, ref path1, _) => {
4307 token::get_ident(path1.node)
4311 &format!("Variable id {} maps to {:?}, not local",
4318 cx.sess.bug(&format!("Variable id {} maps to {:?}, not local",
4325 /// See `expr_ty_adjusted`
4326 pub fn adjust_ty<'tcx, F>(cx: &ctxt<'tcx>,
4328 expr_id: ast::NodeId,
4329 unadjusted_ty: Ty<'tcx>,
4330 adjustment: Option<&AutoAdjustment<'tcx>>,
4333 F: FnMut(MethodCall) -> Option<Ty<'tcx>>,
4335 if let ty_err = unadjusted_ty.sty {
4336 return unadjusted_ty;
4339 return match adjustment {
4340 Some(adjustment) => {
4342 AdjustReifyFnPointer(_) => {
4343 match unadjusted_ty.sty {
4344 ty::ty_bare_fn(Some(_), b) => {
4345 ty::mk_bare_fn(cx, None, b)
4349 &format!("AdjustReifyFnPointer adjustment on non-fn-item: \
4356 AdjustDerefRef(ref adj) => {
4357 let mut adjusted_ty = unadjusted_ty;
4359 if !ty::type_is_error(adjusted_ty) {
4360 for i in range(0, adj.autoderefs) {
4361 let method_call = MethodCall::autoderef(expr_id, i);
4362 match method_type(method_call) {
4363 Some(method_ty) => {
4364 // overloaded deref operators have all late-bound
4365 // regions fully instantiated and coverge
4367 ty::assert_no_late_bound_regions(cx,
4368 &ty_fn_ret(method_ty));
4369 adjusted_ty = fn_ret.unwrap();
4373 match deref(adjusted_ty, true) {
4374 Some(mt) => { adjusted_ty = mt.ty; }
4378 &format!("the {}th autoderef failed: \
4381 ty_to_string(cx, adjusted_ty))
4388 adjust_ty_for_autoref(cx, span, adjusted_ty, adj.autoref.as_ref())
4392 None => unadjusted_ty
4396 pub fn adjust_ty_for_autoref<'tcx>(cx: &ctxt<'tcx>,
4399 autoref: Option<&AutoRef<'tcx>>)
4405 Some(&AutoPtr(r, m, ref a)) => {
4406 let adjusted_ty = match a {
4407 &Some(box ref a) => adjust_ty_for_autoref(cx, span, ty, Some(a)),
4410 mk_rptr(cx, cx.mk_region(r), mt {
4416 Some(&AutoUnsafe(m, ref a)) => {
4417 let adjusted_ty = match a {
4418 &Some(box ref a) => adjust_ty_for_autoref(cx, span, ty, Some(a)),
4421 mk_ptr(cx, mt {ty: adjusted_ty, mutbl: m})
4424 Some(&AutoUnsize(ref k)) => unsize_ty(cx, ty, k, span),
4426 Some(&AutoUnsizeUniq(ref k)) => ty::mk_uniq(cx, unsize_ty(cx, ty, k, span)),
4430 // Take a sized type and a sizing adjustment and produce an unsized version of
4432 pub fn unsize_ty<'tcx>(cx: &ctxt<'tcx>,
4434 kind: &UnsizeKind<'tcx>,
4438 &UnsizeLength(len) => match ty.sty {
4439 ty_vec(ty, Some(n)) => {
4441 mk_vec(cx, ty, None)
4443 _ => cx.sess.span_bug(span,
4444 &format!("UnsizeLength with bad sty: {:?}",
4445 ty_to_string(cx, ty))[])
4447 &UnsizeStruct(box ref k, tp_index) => match ty.sty {
4448 ty_struct(did, substs) => {
4449 let ty_substs = substs.types.get_slice(subst::TypeSpace);
4450 let new_ty = unsize_ty(cx, ty_substs[tp_index], k, span);
4451 let mut unsized_substs = substs.clone();
4452 unsized_substs.types.get_mut_slice(subst::TypeSpace)[tp_index] = new_ty;
4453 mk_struct(cx, did, cx.mk_substs(unsized_substs))
4455 _ => cx.sess.span_bug(span,
4456 &format!("UnsizeStruct with bad sty: {:?}",
4457 ty_to_string(cx, ty))[])
4459 &UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
4460 mk_trait(cx, principal.clone(), bounds.clone())
4465 pub fn resolve_expr(tcx: &ctxt, expr: &ast::Expr) -> def::Def {
4466 match tcx.def_map.borrow().get(&expr.id) {
4469 tcx.sess.span_bug(expr.span, &format!(
4470 "no def-map entry for expr {}", expr.id)[]);
4475 pub fn expr_is_lval(tcx: &ctxt, e: &ast::Expr) -> bool {
4476 match expr_kind(tcx, e) {
4478 RvalueDpsExpr | RvalueDatumExpr | RvalueStmtExpr => false
4482 /// We categorize expressions into three kinds. The distinction between
4483 /// lvalue/rvalue is fundamental to the language. The distinction between the
4484 /// two kinds of rvalues is an artifact of trans which reflects how we will
4485 /// generate code for that kind of expression. See trans/expr.rs for more
4495 pub fn expr_kind(tcx: &ctxt, expr: &ast::Expr) -> ExprKind {
4496 if tcx.method_map.borrow().contains_key(&MethodCall::expr(expr.id)) {
4497 // Overloaded operations are generally calls, and hence they are
4498 // generated via DPS, but there are a few exceptions:
4499 return match expr.node {
4500 // `a += b` has a unit result.
4501 ast::ExprAssignOp(..) => RvalueStmtExpr,
4503 // the deref method invoked for `*a` always yields an `&T`
4504 ast::ExprUnary(ast::UnDeref, _) => LvalueExpr,
4506 // the index method invoked for `a[i]` always yields an `&T`
4507 ast::ExprIndex(..) => LvalueExpr,
4509 // `for` loops are statements
4510 ast::ExprForLoop(..) => RvalueStmtExpr,
4512 // in the general case, result could be any type, use DPS
4518 ast::ExprPath(_) | ast::ExprQPath(_) => {
4519 match resolve_expr(tcx, expr) {
4520 def::DefVariant(tid, vid, _) => {
4521 let variant_info = enum_variant_with_id(tcx, tid, vid);
4522 if variant_info.args.len() > 0u {
4531 def::DefStruct(_) => {
4532 match tcx.node_types.borrow().get(&expr.id) {
4533 Some(ty) => match ty.sty {
4534 ty_bare_fn(..) => RvalueDatumExpr,
4537 // See ExprCast below for why types might be missing.
4538 None => RvalueDatumExpr
4542 // Special case: A unit like struct's constructor must be called without () at the
4543 // end (like `UnitStruct`) which means this is an ExprPath to a DefFn. But in case
4544 // of unit structs this is should not be interpreted as function pointer but as
4545 // call to the constructor.
4546 def::DefFn(_, true) => RvalueDpsExpr,
4548 // Fn pointers are just scalar values.
4549 def::DefFn(..) | def::DefStaticMethod(..) | def::DefMethod(..) => RvalueDatumExpr,
4551 // Note: there is actually a good case to be made that
4552 // DefArg's, particularly those of immediate type, ought to
4553 // considered rvalues.
4554 def::DefStatic(..) |
4556 def::DefLocal(..) => LvalueExpr,
4558 def::DefConst(..) => RvalueDatumExpr,
4563 &format!("uncategorized def for expr {}: {:?}",
4570 ast::ExprUnary(ast::UnDeref, _) |
4571 ast::ExprField(..) |
4572 ast::ExprTupField(..) |
4573 ast::ExprIndex(..) => {
4578 ast::ExprMethodCall(..) |
4579 ast::ExprStruct(..) |
4580 ast::ExprRange(..) |
4583 ast::ExprMatch(..) |
4584 ast::ExprClosure(..) |
4585 ast::ExprBlock(..) |
4586 ast::ExprRepeat(..) |
4587 ast::ExprVec(..) => {
4591 ast::ExprIfLet(..) => {
4592 tcx.sess.span_bug(expr.span, "non-desugared ExprIfLet");
4594 ast::ExprWhileLet(..) => {
4595 tcx.sess.span_bug(expr.span, "non-desugared ExprWhileLet");
4598 ast::ExprLit(ref lit) if lit_is_str(&**lit) => {
4602 ast::ExprCast(..) => {
4603 match tcx.node_types.borrow().get(&expr.id) {
4605 if type_is_trait(ty) {
4612 // Technically, it should not happen that the expr is not
4613 // present within the table. However, it DOES happen
4614 // during type check, because the final types from the
4615 // expressions are not yet recorded in the tcx. At that
4616 // time, though, we are only interested in knowing lvalue
4617 // vs rvalue. It would be better to base this decision on
4618 // the AST type in cast node---but (at the time of this
4619 // writing) it's not easy to distinguish casts to traits
4620 // from other casts based on the AST. This should be
4621 // easier in the future, when casts to traits
4622 // would like @Foo, Box<Foo>, or &Foo.
4628 ast::ExprBreak(..) |
4629 ast::ExprAgain(..) |
4631 ast::ExprWhile(..) |
4633 ast::ExprAssign(..) |
4634 ast::ExprInlineAsm(..) |
4635 ast::ExprAssignOp(..) |
4636 ast::ExprForLoop(..) => {
4640 ast::ExprLit(_) | // Note: LitStr is carved out above
4641 ast::ExprUnary(..) |
4642 ast::ExprBox(None, _) |
4643 ast::ExprAddrOf(..) |
4644 ast::ExprBinary(..) => {
4648 ast::ExprBox(Some(ref place), _) => {
4649 // Special case `Box<T>` for now:
4650 let definition = match tcx.def_map.borrow().get(&place.id) {
4652 None => panic!("no def for place"),
4654 let def_id = definition.def_id();
4655 if tcx.lang_items.exchange_heap() == Some(def_id) {
4662 ast::ExprParen(ref e) => expr_kind(tcx, &**e),
4664 ast::ExprMac(..) => {
4667 "macro expression remains after expansion");
4672 pub fn stmt_node_id(s: &ast::Stmt) -> ast::NodeId {
4674 ast::StmtDecl(_, id) | StmtExpr(_, id) | StmtSemi(_, id) => {
4677 ast::StmtMac(..) => panic!("unexpanded macro in trans")
4681 pub fn field_idx_strict(tcx: &ctxt, name: ast::Name, fields: &[field])
4684 for f in fields.iter() { if f.name == name { return i; } i += 1u; }
4685 tcx.sess.bug(&format!(
4686 "no field named `{}` found in the list of fields `{:?}`",
4687 token::get_name(name),
4689 .map(|f| token::get_name(f.name).get().to_string())
4690 .collect::<Vec<String>>())[]);
4693 pub fn impl_or_trait_item_idx(id: ast::Name, trait_items: &[ImplOrTraitItem])
4695 trait_items.iter().position(|m| m.name() == id)
4698 pub fn ty_sort_string<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> String {
4700 ty_bool | ty_char | ty_int(_) |
4701 ty_uint(_) | ty_float(_) | ty_str => {
4702 ::util::ppaux::ty_to_string(cx, ty)
4704 ty_tup(ref tys) if tys.is_empty() => ::util::ppaux::ty_to_string(cx, ty),
4706 ty_enum(id, _) => format!("enum `{}`", item_path_str(cx, id)),
4707 ty_uniq(_) => "box".to_string(),
4708 ty_vec(_, Some(n)) => format!("array of {} elements", n),
4709 ty_vec(_, None) => "slice".to_string(),
4710 ty_ptr(_) => "*-ptr".to_string(),
4711 ty_rptr(_, _) => "&-ptr".to_string(),
4712 ty_bare_fn(Some(_), _) => format!("fn item"),
4713 ty_bare_fn(None, _) => "fn pointer".to_string(),
4714 ty_trait(ref inner) => {
4715 format!("trait {}", item_path_str(cx, inner.principal_def_id()))
4717 ty_struct(id, _) => {
4718 format!("struct `{}`", item_path_str(cx, id))
4720 ty_unboxed_closure(..) => "closure".to_string(),
4721 ty_tup(_) => "tuple".to_string(),
4722 ty_infer(TyVar(_)) => "inferred type".to_string(),
4723 ty_infer(IntVar(_)) => "integral variable".to_string(),
4724 ty_infer(FloatVar(_)) => "floating-point variable".to_string(),
4725 ty_infer(FreshTy(_)) => "skolemized type".to_string(),
4726 ty_infer(FreshIntTy(_)) => "skolemized integral type".to_string(),
4727 ty_projection(_) => "associated type".to_string(),
4728 ty_param(ref p) => {
4729 if p.space == subst::SelfSpace {
4732 "type parameter".to_string()
4735 ty_err => "type error".to_string(),
4736 ty_open(_) => "opened DST".to_string(),
4740 impl<'tcx> Repr<'tcx> for ty::type_err<'tcx> {
4741 fn repr(&self, tcx: &ty::ctxt<'tcx>) -> String {
4742 ty::type_err_to_str(tcx, self)
4746 /// Explains the source of a type err in a short, human readable way. This is meant to be placed
4747 /// in parentheses after some larger message. You should also invoke `note_and_explain_type_err()`
4748 /// afterwards to present additional details, particularly when it comes to lifetime-related
4750 pub fn type_err_to_str<'tcx>(cx: &ctxt<'tcx>, err: &type_err<'tcx>) -> String {
4751 fn tstore_to_closure(s: &TraitStore) -> String {
4753 &UniqTraitStore => "proc".to_string(),
4754 &RegionTraitStore(..) => "closure".to_string()
4759 terr_cyclic_ty => "cyclic type of infinite size".to_string(),
4760 terr_mismatch => "types differ".to_string(),
4761 terr_unsafety_mismatch(values) => {
4762 format!("expected {} fn, found {} fn",
4766 terr_abi_mismatch(values) => {
4767 format!("expected {} fn, found {} fn",
4771 terr_onceness_mismatch(values) => {
4772 format!("expected {} fn, found {} fn",
4776 terr_sigil_mismatch(values) => {
4777 format!("expected {}, found {}",
4778 tstore_to_closure(&values.expected),
4779 tstore_to_closure(&values.found))
4781 terr_mutability => "values differ in mutability".to_string(),
4782 terr_box_mutability => {
4783 "boxed values differ in mutability".to_string()
4785 terr_vec_mutability => "vectors differ in mutability".to_string(),
4786 terr_ptr_mutability => "pointers differ in mutability".to_string(),
4787 terr_ref_mutability => "references differ in mutability".to_string(),
4788 terr_ty_param_size(values) => {
4789 format!("expected a type with {} type params, \
4790 found one with {} type params",
4794 terr_fixed_array_size(values) => {
4795 format!("expected an array with a fixed size of {} elements, \
4796 found one with {} elements",
4800 terr_tuple_size(values) => {
4801 format!("expected a tuple with {} elements, \
4802 found one with {} elements",
4807 "incorrect number of function parameters".to_string()
4809 terr_regions_does_not_outlive(..) => {
4810 "lifetime mismatch".to_string()
4812 terr_regions_not_same(..) => {
4813 "lifetimes are not the same".to_string()
4815 terr_regions_no_overlap(..) => {
4816 "lifetimes do not intersect".to_string()
4818 terr_regions_insufficiently_polymorphic(br, _) => {
4819 format!("expected bound lifetime parameter {}, \
4820 found concrete lifetime",
4821 bound_region_ptr_to_string(cx, br))
4823 terr_regions_overly_polymorphic(br, _) => {
4824 format!("expected concrete lifetime, \
4825 found bound lifetime parameter {}",
4826 bound_region_ptr_to_string(cx, br))
4828 terr_trait_stores_differ(_, ref values) => {
4829 format!("trait storage differs: expected `{}`, found `{}`",
4830 trait_store_to_string(cx, (*values).expected),
4831 trait_store_to_string(cx, (*values).found))
4833 terr_sorts(values) => {
4834 // A naive approach to making sure that we're not reporting silly errors such as:
4835 // (expected closure, found closure).
4836 let expected_str = ty_sort_string(cx, values.expected);
4837 let found_str = ty_sort_string(cx, values.found);
4838 if expected_str == found_str {
4839 format!("expected {}, found a different {}", expected_str, found_str)
4841 format!("expected {}, found {}", expected_str, found_str)
4844 terr_traits(values) => {
4845 format!("expected trait `{}`, found trait `{}`",
4846 item_path_str(cx, values.expected),
4847 item_path_str(cx, values.found))
4849 terr_builtin_bounds(values) => {
4850 if values.expected.is_empty() {
4851 format!("expected no bounds, found `{}`",
4852 values.found.user_string(cx))
4853 } else if values.found.is_empty() {
4854 format!("expected bounds `{}`, found no bounds",
4855 values.expected.user_string(cx))
4857 format!("expected bounds `{}`, found bounds `{}`",
4858 values.expected.user_string(cx),
4859 values.found.user_string(cx))
4862 terr_integer_as_char => {
4863 "expected an integral type, found `char`".to_string()
4865 terr_int_mismatch(ref values) => {
4866 format!("expected `{:?}`, found `{:?}`",
4870 terr_float_mismatch(ref values) => {
4871 format!("expected `{:?}`, found `{:?}`",
4875 terr_variadic_mismatch(ref values) => {
4876 format!("expected {} fn, found {} function",
4877 if values.expected { "variadic" } else { "non-variadic" },
4878 if values.found { "variadic" } else { "non-variadic" })
4880 terr_convergence_mismatch(ref values) => {
4881 format!("expected {} fn, found {} function",
4882 if values.expected { "converging" } else { "diverging" },
4883 if values.found { "converging" } else { "diverging" })
4885 terr_projection_name_mismatched(ref values) => {
4886 format!("expected {}, found {}",
4887 token::get_name(values.expected),
4888 token::get_name(values.found))
4890 terr_projection_bounds_length(ref values) => {
4891 format!("expected {} associated type bindings, found {}",
4898 pub fn note_and_explain_type_err(cx: &ctxt, err: &type_err) {
4900 terr_regions_does_not_outlive(subregion, superregion) => {
4901 note_and_explain_region(cx, "", subregion, "...");
4902 note_and_explain_region(cx, "...does not necessarily outlive ",
4905 terr_regions_not_same(region1, region2) => {
4906 note_and_explain_region(cx, "", region1, "...");
4907 note_and_explain_region(cx, "...is not the same lifetime as ",
4910 terr_regions_no_overlap(region1, region2) => {
4911 note_and_explain_region(cx, "", region1, "...");
4912 note_and_explain_region(cx, "...does not overlap ",
4915 terr_regions_insufficiently_polymorphic(_, conc_region) => {
4916 note_and_explain_region(cx,
4917 "concrete lifetime that was found is ",
4920 terr_regions_overly_polymorphic(_, ty::ReInfer(ty::ReVar(_))) => {
4921 // don't bother to print out the message below for
4922 // inference variables, it's not very illuminating.
4924 terr_regions_overly_polymorphic(_, conc_region) => {
4925 note_and_explain_region(cx,
4926 "expected concrete lifetime is ",
4933 pub fn provided_source(cx: &ctxt, id: ast::DefId) -> Option<ast::DefId> {
4934 cx.provided_method_sources.borrow().get(&id).map(|x| *x)
4937 pub fn provided_trait_methods<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
4938 -> Vec<Rc<Method<'tcx>>> {
4940 match cx.map.find(id.node) {
4941 Some(ast_map::NodeItem(item)) => {
4943 ItemTrait(_, _, _, ref ms) => {
4945 ast_util::split_trait_methods(&ms[]);
4948 match impl_or_trait_item(
4950 ast_util::local_def(m.id)) {
4951 MethodTraitItem(m) => m,
4952 TypeTraitItem(_) => {
4953 cx.sess.bug("provided_trait_methods(): \
4954 split_trait_methods() put \
4955 associated types in the \
4956 provided method bucket?!")
4962 cx.sess.bug(&format!("provided_trait_methods: `{:?}` is \
4969 cx.sess.bug(&format!("provided_trait_methods: `{:?}` is not a \
4975 csearch::get_provided_trait_methods(cx, id)
4979 /// Helper for looking things up in the various maps that are populated during
4980 /// typeck::collect (e.g., `cx.impl_or_trait_items`, `cx.tcache`, etc). All of
4981 /// these share the pattern that if the id is local, it should have been loaded
4982 /// into the map by the `typeck::collect` phase. If the def-id is external,
4983 /// then we have to go consult the crate loading code (and cache the result for
4985 fn lookup_locally_or_in_crate_store<V, F>(descr: &str,
4987 map: &mut DefIdMap<V>,
4988 load_external: F) -> V where
4992 match map.get(&def_id).cloned() {
4993 Some(v) => { return v; }
4997 if def_id.krate == ast::LOCAL_CRATE {
4998 panic!("No def'n found for {:?} in tcx.{}", def_id, descr);
5000 let v = load_external();
5001 map.insert(def_id, v.clone());
5005 pub fn trait_item<'tcx>(cx: &ctxt<'tcx>, trait_did: ast::DefId, idx: uint)
5006 -> ImplOrTraitItem<'tcx> {
5007 let method_def_id = (*ty::trait_item_def_ids(cx, trait_did))[idx].def_id();
5008 impl_or_trait_item(cx, method_def_id)
5011 pub fn trait_items<'tcx>(cx: &ctxt<'tcx>, trait_did: ast::DefId)
5012 -> Rc<Vec<ImplOrTraitItem<'tcx>>> {
5013 let mut trait_items = cx.trait_items_cache.borrow_mut();
5014 match trait_items.get(&trait_did).cloned() {
5015 Some(trait_items) => trait_items,
5017 let def_ids = ty::trait_item_def_ids(cx, trait_did);
5018 let items: Rc<Vec<ImplOrTraitItem>> =
5019 Rc::new(def_ids.iter()
5020 .map(|d| impl_or_trait_item(cx, d.def_id()))
5022 trait_items.insert(trait_did, items.clone());
5028 pub fn impl_or_trait_item<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5029 -> ImplOrTraitItem<'tcx> {
5030 lookup_locally_or_in_crate_store("impl_or_trait_items",
5032 &mut *cx.impl_or_trait_items
5035 csearch::get_impl_or_trait_item(cx, id)
5039 /// Returns true if the given ID refers to an associated type and false if it
5040 /// refers to anything else.
5041 pub fn is_associated_type(cx: &ctxt, id: ast::DefId) -> bool {
5042 memoized(&cx.associated_types, id, |id: ast::DefId| {
5043 if id.krate == ast::LOCAL_CRATE {
5044 match cx.impl_or_trait_items.borrow().get(&id) {
5047 TypeTraitItem(_) => true,
5048 MethodTraitItem(_) => false,
5054 csearch::is_associated_type(&cx.sess.cstore, id)
5059 /// Returns the parameter index that the given associated type corresponds to.
5060 pub fn associated_type_parameter_index(cx: &ctxt,
5061 trait_def: &TraitDef,
5062 associated_type_id: ast::DefId)
5064 for type_parameter_def in trait_def.generics.types.iter() {
5065 if type_parameter_def.def_id == associated_type_id {
5066 return type_parameter_def.index as uint
5069 cx.sess.bug("couldn't find associated type parameter index")
5072 #[derive(Copy, PartialEq, Eq)]
5073 pub struct AssociatedTypeInfo {
5074 pub def_id: ast::DefId,
5076 pub name: ast::Name,
5079 impl PartialOrd for AssociatedTypeInfo {
5080 fn partial_cmp(&self, other: &AssociatedTypeInfo) -> Option<Ordering> {
5081 Some(self.index.cmp(&other.index))
5085 impl Ord for AssociatedTypeInfo {
5086 fn cmp(&self, other: &AssociatedTypeInfo) -> Ordering {
5087 self.index.cmp(&other.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_unboxed_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::assert_no_late_bound_regions(cx, &ty_fn_args(ctor_ty))
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(ast_map::Values(csearch::get_item_path(cx, id).iter()).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 match variant.node.disr_expr {
5344 match const_eval::eval_const_expr_partial(cx, &**e) {
5345 Ok(const_eval::const_int(val)) => {
5346 discriminant = val as Disr
5348 Ok(const_eval::const_uint(val)) => {
5349 discriminant = val as Disr
5354 "expected signed integer constant");
5359 &format!("expected constant: {}",
5366 last_discriminant = Some(discriminant);
5367 Rc::new(VariantInfo::from_ast_variant(cx, &**variant,
5372 cx.sess.bug("enum_variants: id not bound to an enum")
5376 _ => cx.sess.bug("enum_variants: id not bound to an enum")
5382 // Returns information about the enum variant with the given ID:
5383 pub fn enum_variant_with_id<'tcx>(cx: &ctxt<'tcx>,
5384 enum_id: ast::DefId,
5385 variant_id: ast::DefId)
5386 -> Rc<VariantInfo<'tcx>> {
5387 enum_variants(cx, enum_id).iter()
5388 .find(|variant| variant.id == variant_id)
5389 .expect("enum_variant_with_id(): no variant exists with that ID")
5394 // If the given item is in an external crate, looks up its type and adds it to
5395 // the type cache. Returns the type parameters and type.
5396 pub fn lookup_item_type<'tcx>(cx: &ctxt<'tcx>,
5398 -> TypeScheme<'tcx> {
5399 lookup_locally_or_in_crate_store(
5400 "tcache", did, &mut *cx.tcache.borrow_mut(),
5401 || csearch::get_type(cx, did))
5404 /// Given the did of a trait, returns its canonical trait ref.
5405 pub fn lookup_trait_def<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId)
5406 -> Rc<ty::TraitDef<'tcx>> {
5407 memoized(&cx.trait_defs, did, |did: DefId| {
5408 assert!(did.krate != ast::LOCAL_CRATE);
5409 Rc::new(csearch::get_trait_def(cx, did))
5413 /// Given a reference to a trait, returns the "superbounds" declared
5414 /// on the trait, with appropriate substitutions applied. Basically,
5415 /// this applies a filter to the where clauses on the trait, returning
5416 /// those that have the form:
5418 /// Self : SuperTrait<...>
5420 pub fn predicates_for_trait_ref<'tcx>(tcx: &ctxt<'tcx>,
5421 trait_ref: &PolyTraitRef<'tcx>)
5422 -> Vec<ty::Predicate<'tcx>>
5424 let trait_def = lookup_trait_def(tcx, trait_ref.def_id());
5426 debug!("bounds_for_trait_ref(trait_def={:?}, trait_ref={:?})",
5427 trait_def.repr(tcx), trait_ref.repr(tcx));
5429 // The interaction between HRTB and supertraits is not entirely
5430 // obvious. Let me walk you (and myself) through an example.
5432 // Let's start with an easy case. Consider two traits:
5434 // trait Foo<'a> : Bar<'a,'a> { }
5435 // trait Bar<'b,'c> { }
5437 // Now, if we have a trait reference `for<'x> T : Foo<'x>`, then
5438 // we can deduce that `for<'x> T : Bar<'x,'x>`. Basically, if we
5439 // knew that `Foo<'x>` (for any 'x) then we also know that
5440 // `Bar<'x,'x>` (for any 'x). This more-or-less falls out from
5441 // normal substitution.
5443 // In terms of why this is sound, the idea is that whenever there
5444 // is an impl of `T:Foo<'a>`, it must show that `T:Bar<'a,'a>`
5445 // holds. So if there is an impl of `T:Foo<'a>` that applies to
5446 // all `'a`, then we must know that `T:Bar<'a,'a>` holds for all
5449 // Another example to be careful of is this:
5451 // trait Foo1<'a> : for<'b> Bar1<'a,'b> { }
5452 // trait Bar1<'b,'c> { }
5454 // Here, if we have `for<'x> T : Foo1<'x>`, then what do we know?
5455 // The answer is that we know `for<'x,'b> T : Bar1<'x,'b>`. The
5456 // reason is similar to the previous example: any impl of
5457 // `T:Foo1<'x>` must show that `for<'b> T : Bar1<'x, 'b>`. So
5458 // basically we would want to collapse the bound lifetimes from
5459 // the input (`trait_ref`) and the supertraits.
5461 // To achieve this in practice is fairly straightforward. Let's
5462 // consider the more complicated scenario:
5464 // - We start out with `for<'x> T : Foo1<'x>`. In this case, `'x`
5465 // has a De Bruijn index of 1. We want to produce `for<'x,'b> T : Bar1<'x,'b>`,
5466 // where both `'x` and `'b` would have a DB index of 1.
5467 // The substitution from the input trait-ref is therefore going to be
5468 // `'a => 'x` (where `'x` has a DB index of 1).
5469 // - The super-trait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an
5470 // early-bound parameter and `'b' is a late-bound parameter with a
5472 // - If we replace `'a` with `'x` from the input, it too will have
5473 // a DB index of 1, and thus we'll have `for<'x,'b> Bar1<'x,'b>`
5474 // just as we wanted.
5476 // There is only one catch. If we just apply the substitution `'a
5477 // => 'x` to `for<'b> Bar1<'a,'b>`, the substitution code will
5478 // adjust the DB index because we substituting into a binder (it
5479 // tries to be so smart...) resulting in `for<'x> for<'b>
5480 // Bar1<'x,'b>` (we have no syntax for this, so use your
5481 // imagination). Basically the 'x will have DB index of 2 and 'b
5482 // will have DB index of 1. Not quite what we want. So we apply
5483 // the substitution to the *contents* of the trait reference,
5484 // rather than the trait reference itself (put another way, the
5485 // substitution code expects equal binding levels in the values
5486 // from the substitution and the value being substituted into, and
5487 // this trick achieves that).
5489 // Carefully avoid the binder introduced by each trait-ref by
5490 // substituting over the substs, not the trait-refs themselves,
5491 // thus achieving the "collapse" described in the big comment
5493 let trait_bounds: Vec<_> =
5494 trait_def.bounds.trait_bounds
5496 .map(|poly_trait_ref| ty::Binder(poly_trait_ref.0.subst(tcx, trait_ref.substs())))
5499 let projection_bounds: Vec<_> =
5500 trait_def.bounds.projection_bounds
5502 .map(|poly_proj| ty::Binder(poly_proj.0.subst(tcx, trait_ref.substs())))
5505 debug!("bounds_for_trait_ref: trait_bounds={} projection_bounds={}",
5506 trait_bounds.repr(tcx),
5507 projection_bounds.repr(tcx));
5509 // The region bounds and builtin bounds do not currently introduce
5510 // binders so we can just substitute in a straightforward way here.
5512 trait_def.bounds.region_bounds.subst(tcx, trait_ref.substs());
5513 let builtin_bounds =
5514 trait_def.bounds.builtin_bounds.subst(tcx, trait_ref.substs());
5516 let bounds = ty::ParamBounds {
5517 trait_bounds: trait_bounds,
5518 region_bounds: region_bounds,
5519 builtin_bounds: builtin_bounds,
5520 projection_bounds: projection_bounds,
5523 predicates(tcx, trait_ref.self_ty(), &bounds)
5526 pub fn predicates<'tcx>(
5529 bounds: &ParamBounds<'tcx>)
5530 -> Vec<Predicate<'tcx>>
5532 let mut vec = Vec::new();
5534 for builtin_bound in bounds.builtin_bounds.iter() {
5535 match traits::trait_ref_for_builtin_bound(tcx, builtin_bound, param_ty) {
5536 Ok(trait_ref) => { vec.push(trait_ref.as_predicate()); }
5537 Err(ErrorReported) => { }
5541 for ®ion_bound in bounds.region_bounds.iter() {
5542 // account for the binder being introduced below; no need to shift `param_ty`
5543 // because, at present at least, it can only refer to early-bound regions
5544 let region_bound = ty_fold::shift_region(region_bound, 1);
5545 vec.push(ty::Binder(ty::OutlivesPredicate(param_ty, region_bound)).as_predicate());
5548 for bound_trait_ref in bounds.trait_bounds.iter() {
5549 vec.push(bound_trait_ref.as_predicate());
5552 for projection in bounds.projection_bounds.iter() {
5553 vec.push(projection.as_predicate());
5559 /// Get the attributes of a definition.
5560 pub fn get_attrs<'tcx>(tcx: &'tcx ctxt, did: DefId)
5561 -> CowVec<'tcx, ast::Attribute> {
5563 let item = tcx.map.expect_item(did.node);
5564 Cow::Borrowed(&item.attrs[])
5566 Cow::Owned(csearch::get_item_attrs(&tcx.sess.cstore, did))
5570 /// Determine whether an item is annotated with an attribute
5571 pub fn has_attr(tcx: &ctxt, did: DefId, attr: &str) -> bool {
5572 get_attrs(tcx, did).iter().any(|item| item.check_name(attr))
5575 /// Determine whether an item is annotated with `#[repr(packed)]`
5576 pub fn lookup_packed(tcx: &ctxt, did: DefId) -> bool {
5577 lookup_repr_hints(tcx, did).contains(&attr::ReprPacked)
5580 /// Determine whether an item is annotated with `#[simd]`
5581 pub fn lookup_simd(tcx: &ctxt, did: DefId) -> bool {
5582 has_attr(tcx, did, "simd")
5585 /// Obtain the representation annotation for a struct definition.
5586 pub fn lookup_repr_hints(tcx: &ctxt, did: DefId) -> Rc<Vec<attr::ReprAttr>> {
5587 memoized(&tcx.repr_hint_cache, did, |did: DefId| {
5588 Rc::new(if did.krate == LOCAL_CRATE {
5589 get_attrs(tcx, did).iter().flat_map(|meta| {
5590 attr::find_repr_attrs(tcx.sess.diagnostic(), meta).into_iter()
5593 csearch::get_repr_attrs(&tcx.sess.cstore, did)
5598 // Look up a field ID, whether or not it's local
5599 // Takes a list of type substs in case the struct is generic
5600 pub fn lookup_field_type<'tcx>(tcx: &ctxt<'tcx>,
5603 substs: &Substs<'tcx>)
5605 let ty = if id.krate == ast::LOCAL_CRATE {
5606 node_id_to_type(tcx, id.node)
5608 let mut tcache = tcx.tcache.borrow_mut();
5609 let pty = tcache.entry(id).get().unwrap_or_else(
5610 |vacant_entry| vacant_entry.insert(csearch::get_field_type(tcx, struct_id, id)));
5613 ty.subst(tcx, substs)
5616 // Look up the list of field names and IDs for a given struct.
5617 // Panics if the id is not bound to a struct.
5618 pub fn lookup_struct_fields(cx: &ctxt, did: ast::DefId) -> Vec<field_ty> {
5619 if did.krate == ast::LOCAL_CRATE {
5620 let struct_fields = cx.struct_fields.borrow();
5621 match struct_fields.get(&did) {
5622 Some(fields) => (**fields).clone(),
5625 &format!("ID not mapped to struct fields: {}",
5626 cx.map.node_to_string(did.node))[]);
5630 csearch::get_struct_fields(&cx.sess.cstore, did)
5634 pub fn is_tuple_struct(cx: &ctxt, did: ast::DefId) -> bool {
5635 let fields = lookup_struct_fields(cx, did);
5636 !fields.is_empty() && fields.iter().all(|f| f.name == token::special_names::unnamed_field)
5639 // Returns a list of fields corresponding to the struct's items. trans uses
5640 // this. Takes a list of substs with which to instantiate field types.
5641 pub fn struct_fields<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId, substs: &Substs<'tcx>)
5642 -> Vec<field<'tcx>> {
5643 lookup_struct_fields(cx, did).iter().map(|f| {
5647 ty: lookup_field_type(cx, did, f.id, substs),
5654 // Returns a list of fields corresponding to the tuple's items. trans uses
5656 pub fn tup_fields<'tcx>(v: &[Ty<'tcx>]) -> Vec<field<'tcx>> {
5657 v.iter().enumerate().map(|(i, &f)| {
5659 name: token::intern(&i.to_string()[]),
5668 #[derive(Copy, Clone)]
5669 pub struct UnboxedClosureUpvar<'tcx> {
5675 // Returns a list of `UnboxedClosureUpvar`s for each upvar.
5676 pub fn unboxed_closure_upvars<'tcx>(typer: &mc::Typer<'tcx>,
5677 closure_id: ast::DefId,
5678 substs: &Substs<'tcx>)
5679 -> Option<Vec<UnboxedClosureUpvar<'tcx>>>
5681 // Presently an unboxed closure type cannot "escape" out of a
5682 // function, so we will only encounter ones that originated in the
5683 // local crate or were inlined into it along with some function.
5684 // This may change if abstract return types of some sort are
5686 assert!(closure_id.krate == ast::LOCAL_CRATE);
5687 let tcx = typer.tcx();
5688 let capture_mode = tcx.capture_modes.borrow()[closure_id.node].clone();
5689 match tcx.freevars.borrow().get(&closure_id.node) {
5690 None => Some(vec![]),
5691 Some(ref freevars) => {
5694 let freevar_def_id = freevar.def.def_id();
5695 let freevar_ty = match typer.node_ty(freevar_def_id.node) {
5697 Err(()) => { return None; }
5699 let freevar_ty = freevar_ty.subst(tcx, substs);
5701 match capture_mode {
5702 ast::CaptureByValue => {
5703 Some(UnboxedClosureUpvar { def: freevar.def,
5708 ast::CaptureByRef => {
5709 let upvar_id = ty::UpvarId {
5710 var_id: freevar_def_id.node,
5711 closure_expr_id: closure_id.node
5715 let freevar_ref_ty = match typer.upvar_borrow(upvar_id) {
5718 tcx.mk_region(borrow.region),
5721 mutbl: borrow.kind.to_mutbl_lossy(),
5725 // FIXME(#16640) we should really return None here;
5726 // but that requires better inference integration,
5727 // for now gin up something.
5731 Some(UnboxedClosureUpvar {
5744 pub fn is_binopable<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>, op: ast::BinOp) -> bool {
5745 #![allow(non_upper_case_globals)]
5746 static tycat_other: int = 0;
5747 static tycat_bool: int = 1;
5748 static tycat_char: int = 2;
5749 static tycat_int: int = 3;
5750 static tycat_float: int = 4;
5751 static tycat_raw_ptr: int = 6;
5753 static opcat_add: int = 0;
5754 static opcat_sub: int = 1;
5755 static opcat_mult: int = 2;
5756 static opcat_shift: int = 3;
5757 static opcat_rel: int = 4;
5758 static opcat_eq: int = 5;
5759 static opcat_bit: int = 6;
5760 static opcat_logic: int = 7;
5761 static opcat_mod: int = 8;
5763 fn opcat(op: ast::BinOp) -> int {
5765 ast::BiAdd => opcat_add,
5766 ast::BiSub => opcat_sub,
5767 ast::BiMul => opcat_mult,
5768 ast::BiDiv => opcat_mult,
5769 ast::BiRem => opcat_mod,
5770 ast::BiAnd => opcat_logic,
5771 ast::BiOr => opcat_logic,
5772 ast::BiBitXor => opcat_bit,
5773 ast::BiBitAnd => opcat_bit,
5774 ast::BiBitOr => opcat_bit,
5775 ast::BiShl => opcat_shift,
5776 ast::BiShr => opcat_shift,
5777 ast::BiEq => opcat_eq,
5778 ast::BiNe => opcat_eq,
5779 ast::BiLt => opcat_rel,
5780 ast::BiLe => opcat_rel,
5781 ast::BiGe => opcat_rel,
5782 ast::BiGt => opcat_rel
5786 fn tycat<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> int {
5787 if type_is_simd(cx, ty) {
5788 return tycat(cx, simd_type(cx, ty))
5791 ty_char => tycat_char,
5792 ty_bool => tycat_bool,
5793 ty_int(_) | ty_uint(_) | ty_infer(IntVar(_)) => tycat_int,
5794 ty_float(_) | ty_infer(FloatVar(_)) => tycat_float,
5795 ty_ptr(_) => tycat_raw_ptr,
5800 static t: bool = true;
5801 static f: bool = false;
5804 // +, -, *, shift, rel, ==, bit, logic, mod
5805 /*other*/ [f, f, f, f, f, f, f, f, f],
5806 /*bool*/ [f, f, f, f, t, t, t, t, f],
5807 /*char*/ [f, f, f, f, t, t, f, f, f],
5808 /*int*/ [t, t, t, t, t, t, t, f, t],
5809 /*float*/ [t, t, t, f, t, t, f, f, f],
5810 /*bot*/ [t, t, t, t, t, t, t, t, t],
5811 /*raw ptr*/ [f, f, f, f, t, t, f, f, f]];
5813 return tbl[tycat(cx, ty) as uint ][opcat(op) as uint];
5816 // Returns the repeat count for a repeating vector expression.
5817 pub fn eval_repeat_count(tcx: &ctxt, count_expr: &ast::Expr) -> uint {
5818 match const_eval::eval_const_expr_partial(tcx, count_expr) {
5820 let found = match val {
5821 const_eval::const_uint(count) => return count as uint,
5822 const_eval::const_int(count) if count >= 0 => return count as uint,
5823 const_eval::const_int(_) =>
5825 const_eval::const_float(_) =>
5827 const_eval::const_str(_) =>
5829 const_eval::const_bool(_) =>
5831 const_eval::const_binary(_) =>
5834 tcx.sess.span_err(count_expr.span, &format!(
5835 "expected positive integer for repeat count, found {}",
5839 let found = match count_expr.node {
5840 ast::ExprPath(ast::Path {
5844 }) if segments.len() == 1 =>
5847 "non-constant expression"
5849 tcx.sess.span_err(count_expr.span, &format!(
5850 "expected constant integer for repeat count, found {}",
5857 // Iterate over a type parameter's bounded traits and any supertraits
5858 // of those traits, ignoring kinds.
5859 // Here, the supertraits are the transitive closure of the supertrait
5860 // relation on the supertraits from each bounded trait's constraint
5862 pub fn each_bound_trait_and_supertraits<'tcx, F>(tcx: &ctxt<'tcx>,
5863 bounds: &[PolyTraitRef<'tcx>],
5866 F: FnMut(PolyTraitRef<'tcx>) -> bool,
5868 for bound_trait_ref in traits::transitive_bounds(tcx, bounds) {
5869 if !f(bound_trait_ref) {
5876 pub fn object_region_bounds<'tcx>(
5878 opt_principal: Option<&PolyTraitRef<'tcx>>, // None for closures
5879 others: BuiltinBounds)
5882 // Since we don't actually *know* the self type for an object,
5883 // this "open(err)" serves as a kind of dummy standin -- basically
5884 // a skolemized type.
5885 let open_ty = ty::mk_infer(tcx, FreshTy(0));
5887 let opt_trait_ref = opt_principal.map_or(Vec::new(), |principal| {
5888 // Note that we preserve the overall binding levels here.
5889 assert!(!open_ty.has_escaping_regions());
5890 let substs = tcx.mk_substs(principal.0.substs.with_self_ty(open_ty));
5891 vec!(ty::Binder(Rc::new(ty::TraitRef::new(principal.0.def_id, substs))))
5894 let param_bounds = ty::ParamBounds {
5895 region_bounds: Vec::new(),
5896 builtin_bounds: others,
5897 trait_bounds: opt_trait_ref,
5898 projection_bounds: Vec::new(), // not relevant to computing region bounds
5901 let predicates = ty::predicates(tcx, open_ty, ¶m_bounds);
5902 ty::required_region_bounds(tcx, open_ty, predicates)
5905 /// Given a set of predicates that apply to an object type, returns
5906 /// the region bounds that the (erased) `Self` type must
5907 /// outlive. Precisely *because* the `Self` type is erased, the
5908 /// parameter `erased_self_ty` must be supplied to indicate what type
5909 /// has been used to represent `Self` in the predicates
5910 /// themselves. This should really be a unique type; `FreshTy(0)` is a
5911 /// popular choice (see `object_region_bounds` above).
5913 /// Requires that trait definitions have been processed so that we can
5914 /// elaborate predicates and walk supertraits.
5915 pub fn required_region_bounds<'tcx>(tcx: &ctxt<'tcx>,
5916 erased_self_ty: Ty<'tcx>,
5917 predicates: Vec<ty::Predicate<'tcx>>)
5920 debug!("required_region_bounds(erased_self_ty={:?}, predicates={:?})",
5921 erased_self_ty.repr(tcx),
5922 predicates.repr(tcx));
5924 assert!(!erased_self_ty.has_escaping_regions());
5926 traits::elaborate_predicates(tcx, predicates)
5927 .filter_map(|predicate| {
5929 ty::Predicate::Projection(..) |
5930 ty::Predicate::Trait(..) |
5931 ty::Predicate::Equate(..) |
5932 ty::Predicate::RegionOutlives(..) => {
5935 ty::Predicate::TypeOutlives(ty::Binder(ty::OutlivesPredicate(t, r))) => {
5936 // Search for a bound of the form `erased_self_ty
5937 // : 'a`, but be wary of something like `for<'a>
5938 // erased_self_ty : 'a` (we interpret a
5939 // higher-ranked bound like that as 'static,
5940 // though at present the code in `fulfill.rs`
5941 // considers such bounds to be unsatisfiable, so
5942 // it's kind of a moot point since you could never
5943 // construct such an object, but this seems
5944 // correct even if that code changes).
5945 if t == erased_self_ty && !r.has_escaping_regions() {
5946 if r.has_escaping_regions() {
5960 pub fn get_tydesc_ty<'tcx>(tcx: &ctxt<'tcx>) -> Result<Ty<'tcx>, String> {
5961 tcx.lang_items.require(TyDescStructLangItem).map(|tydesc_lang_item| {
5962 tcx.intrinsic_defs.borrow().get(&tydesc_lang_item).cloned()
5963 .expect("Failed to resolve TyDesc")
5967 pub fn item_variances(tcx: &ctxt, item_id: ast::DefId) -> Rc<ItemVariances> {
5968 lookup_locally_or_in_crate_store(
5969 "item_variance_map", item_id, &mut *tcx.item_variance_map.borrow_mut(),
5970 || Rc::new(csearch::get_item_variances(&tcx.sess.cstore, item_id)))
5973 /// Records a trait-to-implementation mapping.
5974 pub fn record_trait_implementation(tcx: &ctxt,
5975 trait_def_id: DefId,
5976 impl_def_id: DefId) {
5977 match tcx.trait_impls.borrow().get(&trait_def_id) {
5978 Some(impls_for_trait) => {
5979 impls_for_trait.borrow_mut().push(impl_def_id);
5984 tcx.trait_impls.borrow_mut().insert(trait_def_id, Rc::new(RefCell::new(vec!(impl_def_id))));
5987 /// Populates the type context with all the implementations for the given type
5989 pub fn populate_implementations_for_type_if_necessary(tcx: &ctxt,
5990 type_id: ast::DefId) {
5991 if type_id.krate == LOCAL_CRATE {
5994 if tcx.populated_external_types.borrow().contains(&type_id) {
5998 debug!("populate_implementations_for_type_if_necessary: searching for {:?}", type_id);
6000 let mut inherent_impls = Vec::new();
6001 csearch::each_implementation_for_type(&tcx.sess.cstore, type_id,
6003 let impl_items = csearch::get_impl_items(&tcx.sess.cstore, impl_def_id);
6005 // Record the trait->implementation mappings, if applicable.
6006 let associated_traits = csearch::get_impl_trait(tcx, impl_def_id);
6007 for trait_ref in associated_traits.iter() {
6008 record_trait_implementation(tcx, trait_ref.def_id, impl_def_id);
6011 // For any methods that use a default implementation, add them to
6012 // the map. This is a bit unfortunate.
6013 for impl_item_def_id in impl_items.iter() {
6014 let method_def_id = impl_item_def_id.def_id();
6015 match impl_or_trait_item(tcx, method_def_id) {
6016 MethodTraitItem(method) => {
6017 for &source in method.provided_source.iter() {
6018 tcx.provided_method_sources
6020 .insert(method_def_id, source);
6023 TypeTraitItem(_) => {}
6027 // Store the implementation info.
6028 tcx.impl_items.borrow_mut().insert(impl_def_id, impl_items);
6030 // If this is an inherent implementation, record it.
6031 if associated_traits.is_none() {
6032 inherent_impls.push(impl_def_id);
6036 tcx.inherent_impls.borrow_mut().insert(type_id, Rc::new(inherent_impls));
6037 tcx.populated_external_types.borrow_mut().insert(type_id);
6040 /// Populates the type context with all the implementations for the given
6041 /// trait if necessary.
6042 pub fn populate_implementations_for_trait_if_necessary(
6044 trait_id: ast::DefId) {
6045 if trait_id.krate == LOCAL_CRATE {
6048 if tcx.populated_external_traits.borrow().contains(&trait_id) {
6052 csearch::each_implementation_for_trait(&tcx.sess.cstore, trait_id,
6053 |implementation_def_id| {
6054 let impl_items = csearch::get_impl_items(&tcx.sess.cstore, implementation_def_id);
6056 // Record the trait->implementation mapping.
6057 record_trait_implementation(tcx, trait_id, implementation_def_id);
6059 // For any methods that use a default implementation, add them to
6060 // the map. This is a bit unfortunate.
6061 for impl_item_def_id in impl_items.iter() {
6062 let method_def_id = impl_item_def_id.def_id();
6063 match impl_or_trait_item(tcx, method_def_id) {
6064 MethodTraitItem(method) => {
6065 for &source in method.provided_source.iter() {
6066 tcx.provided_method_sources
6068 .insert(method_def_id, source);
6071 TypeTraitItem(_) => {}
6075 // Store the implementation info.
6076 tcx.impl_items.borrow_mut().insert(implementation_def_id, impl_items);
6079 tcx.populated_external_traits.borrow_mut().insert(trait_id);
6082 /// Given the def_id of an impl, return the def_id of the trait it implements.
6083 /// If it implements no trait, return `None`.
6084 pub fn trait_id_of_impl(tcx: &ctxt,
6086 -> Option<ast::DefId> {
6087 ty::impl_trait_ref(tcx, def_id).map(|tr| tr.def_id)
6090 /// If the given def ID describes a method belonging to an impl, return the
6091 /// ID of the impl that the method belongs to. Otherwise, return `None`.
6092 pub fn impl_of_method(tcx: &ctxt, def_id: ast::DefId)
6093 -> Option<ast::DefId> {
6094 if def_id.krate != LOCAL_CRATE {
6095 return match csearch::get_impl_or_trait_item(tcx,
6096 def_id).container() {
6097 TraitContainer(_) => None,
6098 ImplContainer(def_id) => Some(def_id),
6101 match tcx.impl_or_trait_items.borrow().get(&def_id).cloned() {
6102 Some(trait_item) => {
6103 match trait_item.container() {
6104 TraitContainer(_) => None,
6105 ImplContainer(def_id) => Some(def_id),
6112 /// If the given def ID describes an item belonging to a trait (either a
6113 /// default method or an implementation of a trait method), return the ID of
6114 /// the trait that the method belongs to. Otherwise, return `None`.
6115 pub fn trait_of_item(tcx: &ctxt, def_id: ast::DefId) -> Option<ast::DefId> {
6116 if def_id.krate != LOCAL_CRATE {
6117 return csearch::get_trait_of_item(&tcx.sess.cstore, def_id, tcx);
6119 match tcx.impl_or_trait_items.borrow().get(&def_id).cloned() {
6120 Some(impl_or_trait_item) => {
6121 match impl_or_trait_item.container() {
6122 TraitContainer(def_id) => Some(def_id),
6123 ImplContainer(def_id) => trait_id_of_impl(tcx, def_id),
6130 /// If the given def ID describes an item belonging to a trait, (either a
6131 /// default method or an implementation of a trait method), return the ID of
6132 /// the method inside trait definition (this means that if the given def ID
6133 /// is already that of the original trait method, then the return value is
6135 /// Otherwise, return `None`.
6136 pub fn trait_item_of_item(tcx: &ctxt, def_id: ast::DefId)
6137 -> Option<ImplOrTraitItemId> {
6138 let impl_item = match tcx.impl_or_trait_items.borrow().get(&def_id) {
6139 Some(m) => m.clone(),
6140 None => return None,
6142 let name = impl_item.name();
6143 match trait_of_item(tcx, def_id) {
6144 Some(trait_did) => {
6145 let trait_items = ty::trait_items(tcx, trait_did);
6147 .position(|m| m.name() == name)
6148 .map(|idx| ty::trait_item(tcx, trait_did, idx).id())
6154 /// Creates a hash of the type `Ty` which will be the same no matter what crate
6155 /// context it's calculated within. This is used by the `type_id` intrinsic.
6156 pub fn hash_crate_independent<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>, svh: &Svh) -> u64 {
6157 let mut state = SipHasher::new();
6158 helper(tcx, ty, svh, &mut state);
6159 return state.finish();
6161 fn helper<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>, svh: &Svh,
6162 state: &mut SipHasher) {
6163 macro_rules! byte { ($b:expr) => { ($b as u8).hash(state) } }
6164 macro_rules! hash { ($e:expr) => { $e.hash(state) } }
6166 let region = |&: state: &mut SipHasher, r: Region| {
6169 ReLateBound(db, BrAnon(i)) => {
6179 tcx.sess.bug("unexpected region found when hashing a type")
6183 let did = |&: state: &mut SipHasher, did: DefId| {
6184 let h = if ast_util::is_local(did) {
6187 tcx.sess.cstore.get_crate_hash(did.krate)
6189 h.as_str().hash(state);
6190 did.node.hash(state);
6192 let mt = |&: state: &mut SipHasher, mt: mt| {
6193 mt.mutbl.hash(state);
6195 let fn_sig = |&: state: &mut SipHasher, sig: &Binder<FnSig<'tcx>>| {
6196 let sig = anonymize_late_bound_regions(tcx, sig).0;
6197 for a in sig.inputs.iter() { helper(tcx, *a, svh, state); }
6198 if let ty::FnConverging(output) = sig.output {
6199 helper(tcx, output, svh, state);
6202 maybe_walk_ty(ty, |ty| {
6204 ty_bool => byte!(2),
6205 ty_char => byte!(3),
6228 ty_vec(_, Some(n)) => {
6232 ty_vec(_, None) => {
6244 ty_bare_fn(opt_def_id, ref b) => {
6249 fn_sig(state, &b.sig);
6252 ty_trait(ref data) => {
6254 did(state, data.principal_def_id());
6257 let principal = anonymize_late_bound_regions(tcx, &data.principal).0;
6258 for subty in principal.substs.types.iter() {
6259 helper(tcx, *subty, svh, state);
6264 ty_struct(d, _) => {
6268 ty_tup(ref inner) => {
6276 hash!(token::get_name(p.name));
6278 ty_open(_) => byte!(22),
6279 ty_infer(_) => unreachable!(),
6280 ty_err => byte!(23),
6281 ty_unboxed_closure(d, r, _) => {
6286 ty_projection(ref data) => {
6288 did(state, data.trait_ref.def_id);
6289 hash!(token::get_name(data.item_name));
6298 pub fn to_string(self) -> &'static str {
6301 Contravariant => "-",
6308 /// Construct a parameter environment suitable for static contexts or other contexts where there
6309 /// are no free type/lifetime parameters in scope.
6310 pub fn empty_parameter_environment<'a,'tcx>(cx: &'a ctxt<'tcx>) -> ParameterEnvironment<'a,'tcx> {
6311 ty::ParameterEnvironment { tcx: cx,
6312 free_substs: Substs::empty(),
6313 caller_bounds: GenericBounds::empty(),
6314 implicit_region_bound: ty::ReEmpty,
6315 selection_cache: traits::SelectionCache::new(), }
6318 /// See `ParameterEnvironment` struct def'n for details
6319 pub fn construct_parameter_environment<'a,'tcx>(
6320 tcx: &'a ctxt<'tcx>,
6321 generics: &ty::Generics<'tcx>,
6322 free_id: ast::NodeId)
6323 -> ParameterEnvironment<'a, 'tcx>
6327 // Construct the free substs.
6331 let mut types = VecPerParamSpace::empty();
6332 push_types_from_defs(tcx, &mut types, generics.types.as_slice());
6334 // map bound 'a => free 'a
6335 let mut regions = VecPerParamSpace::empty();
6336 push_region_params(&mut regions, free_id, generics.regions.as_slice());
6338 let free_substs = Substs {
6340 regions: subst::NonerasedRegions(regions)
6343 let free_id_scope = region::CodeExtent::from_node_id(free_id);
6346 // Compute the bounds on Self and the type parameters.
6349 let bounds = generics.to_bounds(tcx, &free_substs);
6350 let bounds = liberate_late_bound_regions(tcx, free_id_scope, &ty::Binder(bounds));
6353 // Compute region bounds. For now, these relations are stored in a
6354 // global table on the tcx, so just enter them there. I'm not
6355 // crazy about this scheme, but it's convenient, at least.
6358 record_region_bounds(tcx, &bounds);
6360 debug!("construct_parameter_environment: free_id={:?} free_subst={:?} bounds={:?}",
6362 free_substs.repr(tcx),
6365 return ty::ParameterEnvironment {
6367 free_substs: free_substs,
6368 implicit_region_bound: ty::ReScope(free_id_scope),
6369 caller_bounds: bounds,
6370 selection_cache: traits::SelectionCache::new(),
6373 fn push_region_params(regions: &mut VecPerParamSpace<ty::Region>,
6374 free_id: ast::NodeId,
6375 region_params: &[RegionParameterDef])
6377 for r in region_params.iter() {
6378 regions.push(r.space, ty::free_region_from_def(free_id, r));
6382 fn push_types_from_defs<'tcx>(tcx: &ty::ctxt<'tcx>,
6383 types: &mut VecPerParamSpace<Ty<'tcx>>,
6384 defs: &[TypeParameterDef<'tcx>]) {
6385 for def in defs.iter() {
6386 debug!("construct_parameter_environment(): push_types_from_defs: def={:?}",
6388 let ty = ty::mk_param_from_def(tcx, def);
6389 types.push(def.space, ty);
6393 fn record_region_bounds<'tcx>(tcx: &ty::ctxt<'tcx>, bounds: &GenericBounds<'tcx>) {
6394 debug!("record_region_bounds(bounds={:?})", bounds.repr(tcx));
6396 for predicate in bounds.predicates.iter() {
6398 Predicate::Projection(..) |
6399 Predicate::Trait(..) |
6400 Predicate::Equate(..) |
6401 Predicate::TypeOutlives(..) => {
6402 // No region bounds here
6404 Predicate::RegionOutlives(ty::Binder(ty::OutlivesPredicate(r_a, r_b))) => {
6406 (ty::ReFree(fr_a), ty::ReFree(fr_b)) => {
6407 // Record that `'a:'b`. Or, put another way, `'b <= 'a`.
6408 tcx.region_maps.relate_free_regions(fr_b, fr_a);
6411 // All named regions are instantiated with free regions.
6413 format!("record_region_bounds: non free region: {} / {}",
6415 r_b.repr(tcx)).as_slice());
6425 pub fn from_mutbl(m: ast::Mutability) -> BorrowKind {
6427 ast::MutMutable => MutBorrow,
6428 ast::MutImmutable => ImmBorrow,
6432 /// Returns a mutability `m` such that an `&m T` pointer could be used to obtain this borrow
6433 /// kind. Because borrow kinds are richer than mutabilities, we sometimes have to pick a
6434 /// mutability that is stronger than necessary so that it at least *would permit* the borrow in
6436 pub fn to_mutbl_lossy(self) -> ast::Mutability {
6438 MutBorrow => ast::MutMutable,
6439 ImmBorrow => ast::MutImmutable,
6441 // We have no type corresponding to a unique imm borrow, so
6442 // use `&mut`. It gives all the capabilities of an `&uniq`
6443 // and hence is a safe "over approximation".
6444 UniqueImmBorrow => ast::MutMutable,
6448 pub fn to_user_str(&self) -> &'static str {
6450 MutBorrow => "mutable",
6451 ImmBorrow => "immutable",
6452 UniqueImmBorrow => "uniquely immutable",
6457 impl<'tcx> ctxt<'tcx> {
6458 pub fn capture_mode(&self, closure_expr_id: ast::NodeId)
6459 -> ast::CaptureClause {
6460 self.capture_modes.borrow()[closure_expr_id].clone()
6463 pub fn is_method_call(&self, expr_id: ast::NodeId) -> bool {
6464 self.method_map.borrow().contains_key(&MethodCall::expr(expr_id))
6468 impl<'a,'tcx> mc::Typer<'tcx> for ParameterEnvironment<'a,'tcx> {
6469 fn tcx(&self) -> &ty::ctxt<'tcx> {
6473 fn node_ty(&self, id: ast::NodeId) -> mc::McResult<Ty<'tcx>> {
6474 Ok(ty::node_id_to_type(self.tcx, id))
6477 fn expr_ty_adjusted(&self, expr: &ast::Expr) -> mc::McResult<Ty<'tcx>> {
6478 Ok(ty::expr_ty_adjusted(self.tcx, expr))
6481 fn node_method_ty(&self, method_call: ty::MethodCall) -> Option<Ty<'tcx>> {
6482 self.tcx.method_map.borrow().get(&method_call).map(|method| method.ty)
6485 fn node_method_origin(&self, method_call: ty::MethodCall)
6486 -> Option<ty::MethodOrigin<'tcx>>
6488 self.tcx.method_map.borrow().get(&method_call).map(|method| method.origin.clone())
6491 fn adjustments(&self) -> &RefCell<NodeMap<ty::AutoAdjustment<'tcx>>> {
6492 &self.tcx.adjustments
6495 fn is_method_call(&self, id: ast::NodeId) -> bool {
6496 self.tcx.is_method_call(id)
6499 fn temporary_scope(&self, rvalue_id: ast::NodeId) -> Option<region::CodeExtent> {
6500 self.tcx.region_maps.temporary_scope(rvalue_id)
6503 fn upvar_borrow(&self, upvar_id: ty::UpvarId) -> Option<ty::UpvarBorrow> {
6504 Some(self.tcx.upvar_borrow_map.borrow()[upvar_id].clone())
6507 fn capture_mode(&self, closure_expr_id: ast::NodeId)
6508 -> ast::CaptureClause {
6509 self.tcx.capture_mode(closure_expr_id)
6512 fn type_moves_by_default(&self, span: Span, ty: Ty<'tcx>) -> bool {
6513 type_moves_by_default(self, span, ty)
6517 impl<'a,'tcx> UnboxedClosureTyper<'tcx> for ty::ParameterEnvironment<'a,'tcx> {
6518 fn param_env<'b>(&'b self) -> &'b ty::ParameterEnvironment<'b,'tcx> {
6522 fn unboxed_closure_kind(&self,
6524 -> ty::UnboxedClosureKind
6526 self.tcx.unboxed_closure_kind(def_id)
6529 fn unboxed_closure_type(&self,
6531 substs: &subst::Substs<'tcx>)
6532 -> ty::ClosureTy<'tcx>
6534 self.tcx.unboxed_closure_type(def_id, substs)
6537 fn unboxed_closure_upvars(&self,
6539 substs: &Substs<'tcx>)
6540 -> Option<Vec<UnboxedClosureUpvar<'tcx>>>
6542 unboxed_closure_upvars(self, def_id, substs)
6547 /// The category of explicit self.
6548 #[derive(Clone, Copy, Eq, PartialEq, Show)]
6549 pub enum ExplicitSelfCategory {
6550 StaticExplicitSelfCategory,
6551 ByValueExplicitSelfCategory,
6552 ByReferenceExplicitSelfCategory(Region, ast::Mutability),
6553 ByBoxExplicitSelfCategory,
6556 /// Pushes all the lifetimes in the given type onto the given list. A
6557 /// "lifetime in a type" is a lifetime specified by a reference or a lifetime
6558 /// in a list of type substitutions. This does *not* traverse into nominal
6559 /// types, nor does it resolve fictitious types.
6560 pub fn accumulate_lifetimes_in_type(accumulator: &mut Vec<ty::Region>,
6564 ty_rptr(region, _) => {
6565 accumulator.push(*region)
6567 ty_trait(ref t) => {
6568 accumulator.push_all(t.principal.0.substs.regions().as_slice());
6570 ty_enum(_, substs) |
6571 ty_struct(_, substs) => {
6572 accum_substs(accumulator, substs);
6574 ty_unboxed_closure(_, region, substs) => {
6575 accumulator.push(*region);
6576 accum_substs(accumulator, substs);
6598 fn accum_substs(accumulator: &mut Vec<Region>, substs: &Substs) {
6599 match substs.regions {
6600 subst::ErasedRegions => {}
6601 subst::NonerasedRegions(ref regions) => {
6602 for region in regions.iter() {
6603 accumulator.push(*region)
6610 /// A free variable referred to in a function.
6611 #[derive(Copy, RustcEncodable, RustcDecodable)]
6612 pub struct Freevar {
6613 /// The variable being accessed free.
6616 // First span where it is accessed (there can be multiple).
6620 pub type FreevarMap = NodeMap<Vec<Freevar>>;
6622 pub type CaptureModeMap = NodeMap<ast::CaptureClause>;
6624 // Trait method resolution
6625 pub type TraitMap = NodeMap<Vec<DefId>>;
6627 // Map from the NodeId of a glob import to a list of items which are actually
6629 pub type GlobMap = HashMap<NodeId, HashSet<Name>>;
6631 pub fn with_freevars<T, F>(tcx: &ty::ctxt, fid: ast::NodeId, f: F) -> T where
6632 F: FnOnce(&[Freevar]) -> T,
6634 match tcx.freevars.borrow().get(&fid) {
6640 impl<'tcx> AutoAdjustment<'tcx> {
6641 pub fn is_identity(&self) -> bool {
6643 AdjustReifyFnPointer(..) => false,
6644 AdjustDerefRef(ref r) => r.is_identity(),
6649 impl<'tcx> AutoDerefRef<'tcx> {
6650 pub fn is_identity(&self) -> bool {
6651 self.autoderefs == 0 && self.autoref.is_none()
6655 /// Replace any late-bound regions bound in `value` with free variants attached to scope-id
6657 pub fn liberate_late_bound_regions<'tcx, T>(
6658 tcx: &ty::ctxt<'tcx>,
6659 scope: region::CodeExtent,
6662 where T : TypeFoldable<'tcx> + Repr<'tcx>
6664 replace_late_bound_regions(
6666 |br| ty::ReFree(ty::FreeRegion{scope: scope, bound_region: br})).0
6669 pub fn count_late_bound_regions<'tcx, T>(
6670 tcx: &ty::ctxt<'tcx>,
6673 where T : TypeFoldable<'tcx> + Repr<'tcx>
6675 let (_, skol_map) = replace_late_bound_regions(tcx, value, |_| ty::ReStatic);
6679 pub fn binds_late_bound_regions<'tcx, T>(
6680 tcx: &ty::ctxt<'tcx>,
6683 where T : TypeFoldable<'tcx> + Repr<'tcx>
6685 count_late_bound_regions(tcx, value) > 0
6688 pub fn assert_no_late_bound_regions<'tcx, T>(
6689 tcx: &ty::ctxt<'tcx>,
6692 where T : TypeFoldable<'tcx> + Repr<'tcx> + Clone
6694 assert!(!binds_late_bound_regions(tcx, value));
6698 /// Replace any late-bound regions bound in `value` with `'static`. Useful in trans but also
6699 /// method lookup and a few other places where precise region relationships are not required.
6700 pub fn erase_late_bound_regions<'tcx, T>(
6701 tcx: &ty::ctxt<'tcx>,
6704 where T : TypeFoldable<'tcx> + Repr<'tcx>
6706 replace_late_bound_regions(tcx, value, |_| ty::ReStatic).0
6709 /// Rewrite any late-bound regions so that they are anonymous. Region numbers are
6710 /// assigned starting at 1 and increasing monotonically in the order traversed
6711 /// by the fold operation.
6713 /// The chief purpose of this function is to canonicalize regions so that two
6714 /// `FnSig`s or `TraitRef`s which are equivalent up to region naming will become
6715 /// structurally identical. For example, `for<'a, 'b> fn(&'a int, &'b int)` and
6716 /// `for<'a, 'b> fn(&'b int, &'a int)` will become identical after anonymization.
6717 pub fn anonymize_late_bound_regions<'tcx, T>(
6721 where T : TypeFoldable<'tcx> + Repr<'tcx>,
6723 let mut counter = 0;
6724 ty::Binder(replace_late_bound_regions(tcx, sig, |_| {
6726 ReLateBound(ty::DebruijnIndex::new(1), BrAnon(counter))
6730 /// Replaces the late-bound-regions in `value` that are bound by `value`.
6731 pub fn replace_late_bound_regions<'tcx, T, F>(
6732 tcx: &ty::ctxt<'tcx>,
6735 -> (T, FnvHashMap<ty::BoundRegion,ty::Region>)
6736 where T : TypeFoldable<'tcx> + Repr<'tcx>,
6737 F : FnMut(BoundRegion) -> ty::Region,
6739 debug!("replace_late_bound_regions({})", binder.repr(tcx));
6741 let mut map = FnvHashMap::new();
6743 // Note: fold the field `0`, not the binder, so that late-bound
6744 // regions bound by `binder` are considered free.
6745 let value = ty_fold::fold_regions(tcx, &binder.0, |region, current_depth| {
6746 debug!("region={}", region.repr(tcx));
6748 ty::ReLateBound(debruijn, br) if debruijn.depth == current_depth => {
6750 * map.entry(br).get().unwrap_or_else(
6751 |vacant_entry| vacant_entry.insert(mapf(br)));
6753 if let ty::ReLateBound(debruijn1, br) = region {
6754 // If the callback returns a late-bound region,
6755 // that region should always use depth 1. Then we
6756 // adjust it to the correct depth.
6757 assert_eq!(debruijn1.depth, 1);
6758 ty::ReLateBound(debruijn, br)
6769 debug!("resulting map: {:?} value: {:?}", map, value.repr(tcx));
6773 impl DebruijnIndex {
6774 pub fn new(depth: u32) -> DebruijnIndex {
6776 DebruijnIndex { depth: depth }
6779 pub fn shifted(&self, amount: u32) -> DebruijnIndex {
6780 DebruijnIndex { depth: self.depth + amount }
6784 impl<'tcx> Repr<'tcx> for AutoAdjustment<'tcx> {
6785 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6787 AdjustReifyFnPointer(def_id) => {
6788 format!("AdjustReifyFnPointer({})", def_id.repr(tcx))
6790 AdjustDerefRef(ref data) => {
6797 impl<'tcx> Repr<'tcx> for UnsizeKind<'tcx> {
6798 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6800 UnsizeLength(n) => format!("UnsizeLength({})", n),
6801 UnsizeStruct(ref k, n) => format!("UnsizeStruct({},{})", k.repr(tcx), n),
6802 UnsizeVtable(ref a, ref b) => format!("UnsizeVtable({},{})", a.repr(tcx), b.repr(tcx)),
6807 impl<'tcx> Repr<'tcx> for AutoDerefRef<'tcx> {
6808 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6809 format!("AutoDerefRef({}, {})", self.autoderefs, self.autoref.repr(tcx))
6813 impl<'tcx> Repr<'tcx> for AutoRef<'tcx> {
6814 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6816 AutoPtr(a, b, ref c) => {
6817 format!("AutoPtr({},{:?},{})", a.repr(tcx), b, c.repr(tcx))
6819 AutoUnsize(ref a) => {
6820 format!("AutoUnsize({})", a.repr(tcx))
6822 AutoUnsizeUniq(ref a) => {
6823 format!("AutoUnsizeUniq({})", a.repr(tcx))
6825 AutoUnsafe(ref a, ref b) => {
6826 format!("AutoUnsafe({:?},{})", a, b.repr(tcx))
6832 impl<'tcx> Repr<'tcx> for TyTrait<'tcx> {
6833 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6834 format!("TyTrait({},{})",
6835 self.principal.repr(tcx),
6836 self.bounds.repr(tcx))
6840 impl<'tcx> Repr<'tcx> for ty::Predicate<'tcx> {
6841 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6843 Predicate::Trait(ref a) => a.repr(tcx),
6844 Predicate::Equate(ref pair) => pair.repr(tcx),
6845 Predicate::RegionOutlives(ref pair) => pair.repr(tcx),
6846 Predicate::TypeOutlives(ref pair) => pair.repr(tcx),
6847 Predicate::Projection(ref pair) => pair.repr(tcx),
6852 impl<'tcx> Repr<'tcx> for vtable_origin<'tcx> {
6853 fn repr(&self, tcx: &ty::ctxt<'tcx>) -> String {
6855 vtable_static(def_id, ref tys, ref vtable_res) => {
6856 format!("vtable_static({:?}:{}, {}, {})",
6858 ty::item_path_str(tcx, def_id),
6860 vtable_res.repr(tcx))
6863 vtable_param(x, y) => {
6864 format!("vtable_param({:?}, {})", x, y)
6867 vtable_unboxed_closure(def_id) => {
6868 format!("vtable_unboxed_closure({:?})", def_id)
6872 format!("vtable_error")
6878 pub fn make_substs_for_receiver_types<'tcx>(tcx: &ty::ctxt<'tcx>,
6879 trait_ref: &ty::TraitRef<'tcx>,
6880 method: &ty::Method<'tcx>)
6881 -> subst::Substs<'tcx>
6884 * Substitutes the values for the receiver's type parameters
6885 * that are found in method, leaving the method's type parameters
6889 let meth_tps: Vec<Ty> =
6890 method.generics.types.get_slice(subst::FnSpace)
6892 .map(|def| ty::mk_param_from_def(tcx, def))
6894 let meth_regions: Vec<ty::Region> =
6895 method.generics.regions.get_slice(subst::FnSpace)
6897 .map(|def| ty::ReEarlyBound(def.def_id.node, def.space,
6898 def.index, def.name))
6900 trait_ref.substs.clone().with_method(meth_tps, meth_regions)
6904 pub enum CopyImplementationError {
6905 FieldDoesNotImplementCopy(ast::Name),
6906 VariantDoesNotImplementCopy(ast::Name),
6911 pub fn can_type_implement_copy<'a,'tcx>(param_env: &ParameterEnvironment<'a, 'tcx>,
6913 self_type: Ty<'tcx>)
6914 -> Result<(),CopyImplementationError>
6916 let tcx = param_env.tcx;
6918 let did = match self_type.sty {
6919 ty::ty_struct(struct_did, substs) => {
6920 let fields = ty::struct_fields(tcx, struct_did, substs);
6921 for field in fields.iter() {
6922 if type_moves_by_default(param_env, span, field.mt.ty) {
6923 return Err(FieldDoesNotImplementCopy(field.name))
6928 ty::ty_enum(enum_did, substs) => {
6929 let enum_variants = ty::enum_variants(tcx, enum_did);
6930 for variant in enum_variants.iter() {
6931 for variant_arg_type in variant.args.iter() {
6932 let substd_arg_type =
6933 variant_arg_type.subst(tcx, substs);
6934 if type_moves_by_default(param_env, span, substd_arg_type) {
6935 return Err(VariantDoesNotImplementCopy(variant.name))
6941 _ => return Err(TypeIsStructural),
6944 if ty::has_dtor(tcx, did) {
6945 return Err(TypeHasDestructor)
6951 // FIXME(#20298) -- all of these types basically walk various
6952 // structures to test whether types/regions are reachable with various
6953 // properties. It should be possible to express them in terms of one
6954 // common "walker" trait or something.
6956 pub trait RegionEscape {
6957 fn has_escaping_regions(&self) -> bool {
6958 self.has_regions_escaping_depth(0)
6961 fn has_regions_escaping_depth(&self, depth: u32) -> bool;
6964 impl<'tcx> RegionEscape for Ty<'tcx> {
6965 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6966 ty::type_escapes_depth(*self, depth)
6970 impl<'tcx> RegionEscape for Substs<'tcx> {
6971 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6972 self.types.has_regions_escaping_depth(depth) ||
6973 self.regions.has_regions_escaping_depth(depth)
6977 impl<'tcx,T:RegionEscape> RegionEscape for VecPerParamSpace<T> {
6978 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6979 self.iter_enumerated().any(|(space, _, t)| {
6980 if space == subst::FnSpace {
6981 t.has_regions_escaping_depth(depth+1)
6983 t.has_regions_escaping_depth(depth)
6989 impl<'tcx> RegionEscape for TypeScheme<'tcx> {
6990 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6991 self.ty.has_regions_escaping_depth(depth) ||
6992 self.generics.has_regions_escaping_depth(depth)
6996 impl RegionEscape for Region {
6997 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6998 self.escapes_depth(depth)
7002 impl<'tcx> RegionEscape for Generics<'tcx> {
7003 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7004 self.predicates.has_regions_escaping_depth(depth)
7008 impl<'tcx> RegionEscape for Predicate<'tcx> {
7009 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7011 Predicate::Trait(ref data) => data.has_regions_escaping_depth(depth),
7012 Predicate::Equate(ref data) => data.has_regions_escaping_depth(depth),
7013 Predicate::RegionOutlives(ref data) => data.has_regions_escaping_depth(depth),
7014 Predicate::TypeOutlives(ref data) => data.has_regions_escaping_depth(depth),
7015 Predicate::Projection(ref data) => data.has_regions_escaping_depth(depth),
7020 impl<'tcx> RegionEscape for TraitRef<'tcx> {
7021 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7022 self.substs.types.iter().any(|t| t.has_regions_escaping_depth(depth)) ||
7023 self.substs.regions.has_regions_escaping_depth(depth)
7027 impl<'tcx> RegionEscape for subst::RegionSubsts {
7028 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7030 subst::ErasedRegions => false,
7031 subst::NonerasedRegions(ref r) => {
7032 r.iter().any(|t| t.has_regions_escaping_depth(depth))
7038 impl<'tcx,T:RegionEscape> RegionEscape for Binder<T> {
7039 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7040 self.0.has_regions_escaping_depth(depth + 1)
7044 impl<'tcx> RegionEscape for EquatePredicate<'tcx> {
7045 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7046 self.0.has_regions_escaping_depth(depth) || self.1.has_regions_escaping_depth(depth)
7050 impl<'tcx> RegionEscape for TraitPredicate<'tcx> {
7051 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7052 self.trait_ref.has_regions_escaping_depth(depth)
7056 impl<T:RegionEscape,U:RegionEscape> RegionEscape for OutlivesPredicate<T,U> {
7057 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7058 self.0.has_regions_escaping_depth(depth) || self.1.has_regions_escaping_depth(depth)
7062 impl<'tcx> RegionEscape for ProjectionPredicate<'tcx> {
7063 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7064 self.projection_ty.has_regions_escaping_depth(depth) ||
7065 self.ty.has_regions_escaping_depth(depth)
7069 impl<'tcx> RegionEscape for ProjectionTy<'tcx> {
7070 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7071 self.trait_ref.has_regions_escaping_depth(depth)
7075 impl<'tcx> Repr<'tcx> for ty::ProjectionPredicate<'tcx> {
7076 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7077 format!("ProjectionPredicate({}, {})",
7078 self.projection_ty.repr(tcx),
7083 pub trait HasProjectionTypes {
7084 fn has_projection_types(&self) -> bool;
7087 impl<'tcx,T:HasProjectionTypes> HasProjectionTypes for Vec<T> {
7088 fn has_projection_types(&self) -> bool {
7089 self.iter().any(|p| p.has_projection_types())
7093 impl<'tcx,T:HasProjectionTypes> HasProjectionTypes for VecPerParamSpace<T> {
7094 fn has_projection_types(&self) -> bool {
7095 self.iter().any(|p| p.has_projection_types())
7099 impl<'tcx> HasProjectionTypes for ClosureTy<'tcx> {
7100 fn has_projection_types(&self) -> bool {
7101 self.sig.has_projection_types()
7105 impl<'tcx> HasProjectionTypes for UnboxedClosureUpvar<'tcx> {
7106 fn has_projection_types(&self) -> bool {
7107 self.ty.has_projection_types()
7111 impl<'tcx> HasProjectionTypes for ty::GenericBounds<'tcx> {
7112 fn has_projection_types(&self) -> bool {
7113 self.predicates.has_projection_types()
7117 impl<'tcx> HasProjectionTypes for Predicate<'tcx> {
7118 fn has_projection_types(&self) -> bool {
7120 Predicate::Trait(ref data) => data.has_projection_types(),
7121 Predicate::Equate(ref data) => data.has_projection_types(),
7122 Predicate::RegionOutlives(ref data) => data.has_projection_types(),
7123 Predicate::TypeOutlives(ref data) => data.has_projection_types(),
7124 Predicate::Projection(ref data) => data.has_projection_types(),
7129 impl<'tcx> HasProjectionTypes for TraitPredicate<'tcx> {
7130 fn has_projection_types(&self) -> bool {
7131 self.trait_ref.has_projection_types()
7135 impl<'tcx> HasProjectionTypes for EquatePredicate<'tcx> {
7136 fn has_projection_types(&self) -> bool {
7137 self.0.has_projection_types() || self.1.has_projection_types()
7141 impl HasProjectionTypes for Region {
7142 fn has_projection_types(&self) -> bool {
7147 impl<T:HasProjectionTypes,U:HasProjectionTypes> HasProjectionTypes for OutlivesPredicate<T,U> {
7148 fn has_projection_types(&self) -> bool {
7149 self.0.has_projection_types() || self.1.has_projection_types()
7153 impl<'tcx> HasProjectionTypes for ProjectionPredicate<'tcx> {
7154 fn has_projection_types(&self) -> bool {
7155 self.projection_ty.has_projection_types() || self.ty.has_projection_types()
7159 impl<'tcx> HasProjectionTypes for ProjectionTy<'tcx> {
7160 fn has_projection_types(&self) -> bool {
7161 self.trait_ref.has_projection_types()
7165 impl<'tcx> HasProjectionTypes for Ty<'tcx> {
7166 fn has_projection_types(&self) -> bool {
7167 ty::type_has_projection(*self)
7171 impl<'tcx> HasProjectionTypes for TraitRef<'tcx> {
7172 fn has_projection_types(&self) -> bool {
7173 self.substs.has_projection_types()
7177 impl<'tcx> HasProjectionTypes for subst::Substs<'tcx> {
7178 fn has_projection_types(&self) -> bool {
7179 self.types.iter().any(|t| t.has_projection_types())
7183 impl<'tcx,T> HasProjectionTypes for Option<T>
7184 where T : HasProjectionTypes
7186 fn has_projection_types(&self) -> bool {
7187 self.iter().any(|t| t.has_projection_types())
7191 impl<'tcx,T> HasProjectionTypes for Rc<T>
7192 where T : HasProjectionTypes
7194 fn has_projection_types(&self) -> bool {
7195 (**self).has_projection_types()
7199 impl<'tcx,T> HasProjectionTypes for Box<T>
7200 where T : HasProjectionTypes
7202 fn has_projection_types(&self) -> bool {
7203 (**self).has_projection_types()
7207 impl<T> HasProjectionTypes for Binder<T>
7208 where T : HasProjectionTypes
7210 fn has_projection_types(&self) -> bool {
7211 self.0.has_projection_types()
7215 impl<'tcx> HasProjectionTypes for FnOutput<'tcx> {
7216 fn has_projection_types(&self) -> bool {
7218 FnConverging(t) => t.has_projection_types(),
7219 FnDiverging => false,
7224 impl<'tcx> HasProjectionTypes for FnSig<'tcx> {
7225 fn has_projection_types(&self) -> bool {
7226 self.inputs.iter().any(|t| t.has_projection_types()) ||
7227 self.output.has_projection_types()
7231 impl<'tcx> HasProjectionTypes for field<'tcx> {
7232 fn has_projection_types(&self) -> bool {
7233 self.mt.ty.has_projection_types()
7237 impl<'tcx> HasProjectionTypes for BareFnTy<'tcx> {
7238 fn has_projection_types(&self) -> bool {
7239 self.sig.has_projection_types()
7243 pub trait ReferencesError {
7244 fn references_error(&self) -> bool;
7247 impl<T:ReferencesError> ReferencesError for Binder<T> {
7248 fn references_error(&self) -> bool {
7249 self.0.references_error()
7253 impl<T:ReferencesError> ReferencesError for Rc<T> {
7254 fn references_error(&self) -> bool {
7255 (&**self).references_error()
7259 impl<'tcx> ReferencesError for TraitPredicate<'tcx> {
7260 fn references_error(&self) -> bool {
7261 self.trait_ref.references_error()
7265 impl<'tcx> ReferencesError for ProjectionPredicate<'tcx> {
7266 fn references_error(&self) -> bool {
7267 self.projection_ty.trait_ref.references_error() || self.ty.references_error()
7271 impl<'tcx> ReferencesError for TraitRef<'tcx> {
7272 fn references_error(&self) -> bool {
7273 self.input_types().iter().any(|t| t.references_error())
7277 impl<'tcx> ReferencesError for Ty<'tcx> {
7278 fn references_error(&self) -> bool {
7279 type_is_error(*self)
7283 impl<'tcx> ReferencesError for Predicate<'tcx> {
7284 fn references_error(&self) -> bool {
7286 Predicate::Trait(ref data) => data.references_error(),
7287 Predicate::Equate(ref data) => data.references_error(),
7288 Predicate::RegionOutlives(ref data) => data.references_error(),
7289 Predicate::TypeOutlives(ref data) => data.references_error(),
7290 Predicate::Projection(ref data) => data.references_error(),
7295 impl<A,B> ReferencesError for OutlivesPredicate<A,B>
7296 where A : ReferencesError, B : ReferencesError
7298 fn references_error(&self) -> bool {
7299 self.0.references_error() || self.1.references_error()
7303 impl<'tcx> ReferencesError for EquatePredicate<'tcx>
7305 fn references_error(&self) -> bool {
7306 self.0.references_error() || self.1.references_error()
7310 impl ReferencesError for Region
7312 fn references_error(&self) -> bool {
7317 impl<'tcx> Repr<'tcx> for ClosureTy<'tcx> {
7318 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7319 format!("ClosureTy({},{},{:?},{},{},{})",
7323 self.bounds.repr(tcx),
7329 impl<'tcx> Repr<'tcx> for UnboxedClosureUpvar<'tcx> {
7330 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7331 format!("UnboxedClosureUpvar({},{})",
7337 impl<'tcx> Repr<'tcx> for field<'tcx> {
7338 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7339 format!("field({},{})",
7340 self.name.repr(tcx),
7345 impl<'a, 'tcx> Repr<'tcx> for ParameterEnvironment<'a, 'tcx> {
7346 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7347 format!("ParameterEnvironment(\
7349 implicit_region_bound={}, \
7351 self.free_substs.repr(tcx),
7352 self.implicit_region_bound.repr(tcx),
7353 self.caller_bounds.repr(tcx))