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::Debug 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> {}
950 impl<'tcx, S: Writer + Hasher> Hash<S> for TyS<'tcx> {
951 fn hash(&self, s: &mut S) {
952 (self as *const _).hash(s)
956 pub type Ty<'tcx> = &'tcx TyS<'tcx>;
958 /// An entry in the type interner.
959 pub struct InternedTy<'tcx> {
963 // NB: An InternedTy compares and hashes as a sty.
964 impl<'tcx> PartialEq for InternedTy<'tcx> {
965 fn eq(&self, other: &InternedTy<'tcx>) -> bool {
966 self.ty.sty == other.ty.sty
970 impl<'tcx> Eq for InternedTy<'tcx> {}
972 impl<'tcx, S: Writer + Hasher> Hash<S> for InternedTy<'tcx> {
973 fn hash(&self, s: &mut S) {
978 impl<'tcx> BorrowFrom<InternedTy<'tcx>> for sty<'tcx> {
979 fn borrow_from<'a>(ty: &'a InternedTy<'tcx>) -> &'a sty<'tcx> {
984 pub fn type_has_params(ty: Ty) -> bool {
985 ty.flags.intersects(HAS_PARAMS)
987 pub fn type_has_self(ty: Ty) -> bool {
988 ty.flags.intersects(HAS_SELF)
990 pub fn type_has_ty_infer(ty: Ty) -> bool {
991 ty.flags.intersects(HAS_TY_INFER)
993 pub fn type_needs_infer(ty: Ty) -> bool {
994 ty.flags.intersects(HAS_TY_INFER | HAS_RE_INFER)
996 pub fn type_has_projection(ty: Ty) -> bool {
997 ty.flags.intersects(HAS_PROJECTION)
1000 pub fn type_has_late_bound_regions(ty: Ty) -> bool {
1001 ty.flags.intersects(HAS_RE_LATE_BOUND)
1004 /// An "escaping region" is a bound region whose binder is not part of `t`.
1006 /// So, for example, consider a type like the following, which has two binders:
1008 /// for<'a> fn(x: for<'b> fn(&'a int, &'b int))
1009 /// ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ outer scope
1010 /// ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ inner scope
1012 /// This type has *bound regions* (`'a`, `'b`), but it does not have escaping regions, because the
1013 /// binders of both `'a` and `'b` are part of the type itself. However, if we consider the *inner
1014 /// fn type*, that type has an escaping region: `'a`.
1016 /// Note that what I'm calling an "escaping region" is often just called a "free region". However,
1017 /// we already use the term "free region". It refers to the regions that we use to represent bound
1018 /// regions on a fn definition while we are typechecking its body.
1020 /// To clarify, conceptually there is no particular difference between an "escaping" region and a
1021 /// "free" region. However, there is a big difference in practice. Basically, when "entering" a
1022 /// binding level, one is generally required to do some sort of processing to a bound region, such
1023 /// as replacing it with a fresh/skolemized region, or making an entry in the environment to
1024 /// represent the scope to which it is attached, etc. An escaping region represents a bound region
1025 /// for which this processing has not yet been done.
1026 pub fn type_has_escaping_regions(ty: Ty) -> bool {
1027 type_escapes_depth(ty, 0)
1030 pub fn type_escapes_depth(ty: Ty, depth: u32) -> bool {
1031 ty.region_depth > depth
1034 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1035 pub struct BareFnTy<'tcx> {
1036 pub unsafety: ast::Unsafety,
1038 pub sig: PolyFnSig<'tcx>,
1041 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1042 pub struct ClosureTy<'tcx> {
1043 pub unsafety: ast::Unsafety,
1044 pub onceness: ast::Onceness,
1045 pub store: TraitStore,
1046 pub bounds: ExistentialBounds<'tcx>,
1047 pub sig: PolyFnSig<'tcx>,
1051 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
1052 pub enum FnOutput<'tcx> {
1053 FnConverging(Ty<'tcx>),
1057 impl<'tcx> FnOutput<'tcx> {
1058 pub fn diverges(&self) -> bool {
1059 *self == FnDiverging
1062 pub fn unwrap(self) -> Ty<'tcx> {
1064 ty::FnConverging(t) => t,
1065 ty::FnDiverging => unreachable!()
1070 pub type PolyFnOutput<'tcx> = Binder<FnOutput<'tcx>>;
1072 impl<'tcx> PolyFnOutput<'tcx> {
1073 pub fn diverges(&self) -> bool {
1078 /// Signature of a function type, which I have arbitrarily
1079 /// decided to use to refer to the input/output types.
1081 /// - `inputs` is the list of arguments and their modes.
1082 /// - `output` is the return type.
1083 /// - `variadic` indicates whether this is a variadic function. (only true for foreign fns)
1084 #[derive(Clone, PartialEq, Eq, Hash)]
1085 pub struct FnSig<'tcx> {
1086 pub inputs: Vec<Ty<'tcx>>,
1087 pub output: FnOutput<'tcx>,
1091 pub type PolyFnSig<'tcx> = Binder<FnSig<'tcx>>;
1093 impl<'tcx> PolyFnSig<'tcx> {
1094 pub fn inputs(&self) -> ty::Binder<Vec<Ty<'tcx>>> {
1095 ty::Binder(self.0.inputs.clone())
1097 pub fn input(&self, index: uint) -> ty::Binder<Ty<'tcx>> {
1098 ty::Binder(self.0.inputs[index])
1100 pub fn output(&self) -> ty::Binder<FnOutput<'tcx>> {
1101 ty::Binder(self.0.output.clone())
1103 pub fn variadic(&self) -> bool {
1108 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
1109 pub struct ParamTy {
1110 pub space: subst::ParamSpace,
1112 pub name: ast::Name,
1115 /// A [De Bruijn index][dbi] is a standard means of representing
1116 /// regions (and perhaps later types) in a higher-ranked setting. In
1117 /// particular, imagine a type like this:
1119 /// for<'a> fn(for<'b> fn(&'b int, &'a int), &'a char)
1122 /// | +------------+ 1 | |
1124 /// +--------------------------------+ 2 |
1126 /// +------------------------------------------+ 1
1128 /// In this type, there are two binders (the outer fn and the inner
1129 /// fn). We need to be able to determine, for any given region, which
1130 /// fn type it is bound by, the inner or the outer one. There are
1131 /// various ways you can do this, but a De Bruijn index is one of the
1132 /// more convenient and has some nice properties. The basic idea is to
1133 /// count the number of binders, inside out. Some examples should help
1134 /// clarify what I mean.
1136 /// Let's start with the reference type `&'b int` that is the first
1137 /// argument to the inner function. This region `'b` is assigned a De
1138 /// Bruijn index of 1, meaning "the innermost binder" (in this case, a
1139 /// fn). The region `'a` that appears in the second argument type (`&'a
1140 /// int`) would then be assigned a De Bruijn index of 2, meaning "the
1141 /// second-innermost binder". (These indices are written on the arrays
1142 /// in the diagram).
1144 /// What is interesting is that De Bruijn index attached to a particular
1145 /// variable will vary depending on where it appears. For example,
1146 /// the final type `&'a char` also refers to the region `'a` declared on
1147 /// the outermost fn. But this time, this reference is not nested within
1148 /// any other binders (i.e., it is not an argument to the inner fn, but
1149 /// rather the outer one). Therefore, in this case, it is assigned a
1150 /// De Bruijn index of 1, because the innermost binder in that location
1151 /// is the outer fn.
1153 /// [dbi]: http://en.wikipedia.org/wiki/De_Bruijn_index
1154 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Show, Copy)]
1155 pub struct DebruijnIndex {
1156 // We maintain the invariant that this is never 0. So 1 indicates
1157 // the innermost binder. To ensure this, create with `DebruijnIndex::new`.
1161 /// Representation of regions:
1162 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Show, Copy)]
1164 // Region bound in a type or fn declaration which will be
1165 // substituted 'early' -- that is, at the same time when type
1166 // parameters are substituted.
1167 ReEarlyBound(/* param id */ ast::NodeId,
1172 // Region bound in a function scope, which will be substituted when the
1173 // function is called.
1174 ReLateBound(DebruijnIndex, BoundRegion),
1176 /// When checking a function body, the types of all arguments and so forth
1177 /// that refer to bound region parameters are modified to refer to free
1178 /// region parameters.
1181 /// A concrete region naming some expression within the current function.
1182 ReScope(region::CodeExtent),
1184 /// Static data that has an "infinite" lifetime. Top in the region lattice.
1187 /// A region variable. Should not exist after typeck.
1188 ReInfer(InferRegion),
1190 /// Empty lifetime is for data that is never accessed.
1191 /// Bottom in the region lattice. We treat ReEmpty somewhat
1192 /// specially; at least right now, we do not generate instances of
1193 /// it during the GLB computations, but rather
1194 /// generate an error instead. This is to improve error messages.
1195 /// The only way to get an instance of ReEmpty is to have a region
1196 /// variable with no constraints.
1200 /// Upvars do not get their own node-id. Instead, we use the pair of
1201 /// the original var id (that is, the root variable that is referenced
1202 /// by the upvar) and the id of the closure expression.
1203 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
1204 pub struct UpvarId {
1205 pub var_id: ast::NodeId,
1206 pub closure_expr_id: ast::NodeId,
1209 #[derive(Clone, PartialEq, Eq, Hash, Show, RustcEncodable, RustcDecodable, Copy)]
1210 pub enum BorrowKind {
1211 /// Data must be immutable and is aliasable.
1214 /// Data must be immutable but not aliasable. This kind of borrow
1215 /// cannot currently be expressed by the user and is used only in
1216 /// implicit closure bindings. It is needed when you the closure
1217 /// is borrowing or mutating a mutable referent, e.g.:
1219 /// let x: &mut int = ...;
1220 /// let y = || *x += 5;
1222 /// If we were to try to translate this closure into a more explicit
1223 /// form, we'd encounter an error with the code as written:
1225 /// struct Env { x: & &mut int }
1226 /// let x: &mut int = ...;
1227 /// let y = (&mut Env { &x }, fn_ptr); // Closure is pair of env and fn
1228 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
1230 /// This is then illegal because you cannot mutate a `&mut` found
1231 /// in an aliasable location. To solve, you'd have to translate with
1232 /// an `&mut` borrow:
1234 /// struct Env { x: & &mut int }
1235 /// let x: &mut int = ...;
1236 /// let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x
1237 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
1239 /// Now the assignment to `**env.x` is legal, but creating a
1240 /// mutable pointer to `x` is not because `x` is not mutable. We
1241 /// could fix this by declaring `x` as `let mut x`. This is ok in
1242 /// user code, if awkward, but extra weird for closures, since the
1243 /// borrow is hidden.
1245 /// So we introduce a "unique imm" borrow -- the referent is
1246 /// immutable, but not aliasable. This solves the problem. For
1247 /// simplicity, we don't give users the way to express this
1248 /// borrow, it's just used when translating closures.
1251 /// Data is mutable and not aliasable.
1255 /// Information describing the borrowing of an upvar. This is computed
1256 /// during `typeck`, specifically by `regionck`. The general idea is
1257 /// that the compiler analyses treat closures like:
1259 /// let closure: &'e fn() = || {
1260 /// x = 1; // upvar x is assigned to
1261 /// use(y); // upvar y is read
1262 /// foo(&z); // upvar z is borrowed immutably
1265 /// as if they were "desugared" to something loosely like:
1267 /// struct Vars<'x,'y,'z> { x: &'x mut int,
1268 /// y: &'y const int,
1270 /// let closure: &'e fn() = {
1271 /// fn f(env: &Vars) {
1276 /// let env: &'e mut Vars<'x,'y,'z> = &mut Vars { x: &'x mut x,
1282 /// This is basically what happens at runtime. The closure is basically
1283 /// an existentially quantified version of the `(env, f)` pair.
1285 /// This data structure indicates the region and mutability of a single
1286 /// one of the `x...z` borrows.
1288 /// It may not be obvious why each borrowed variable gets its own
1289 /// lifetime (in the desugared version of the example, these are indicated
1290 /// by the lifetime parameters `'x`, `'y`, and `'z` in the `Vars` definition).
1291 /// Each such lifetime must encompass the lifetime `'e` of the closure itself,
1292 /// but need not be identical to it. The reason that this makes sense:
1294 /// - Callers are only permitted to invoke the closure, and hence to
1295 /// use the pointers, within the lifetime `'e`, so clearly `'e` must
1296 /// be a sublifetime of `'x...'z`.
1297 /// - The closure creator knows which upvars were borrowed by the closure
1298 /// and thus `x...z` will be reserved for `'x...'z` respectively.
1299 /// - Through mutation, the borrowed upvars can actually escape
1300 /// the closure, so sometimes it is necessary for them to be larger
1301 /// than the closure lifetime itself.
1302 #[derive(PartialEq, Clone, RustcEncodable, RustcDecodable, Show, Copy)]
1303 pub struct UpvarBorrow {
1304 pub kind: BorrowKind,
1305 pub region: ty::Region,
1308 pub type UpvarBorrowMap = FnvHashMap<UpvarId, UpvarBorrow>;
1311 pub fn is_bound(&self) -> bool {
1313 ty::ReEarlyBound(..) => true,
1314 ty::ReLateBound(..) => true,
1319 pub fn escapes_depth(&self, depth: u32) -> bool {
1321 ty::ReLateBound(debruijn, _) => debruijn.depth > depth,
1327 #[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
1328 RustcEncodable, RustcDecodable, Show, Copy)]
1329 /// A "free" region `fr` can be interpreted as "some region
1330 /// at least as big as the scope `fr.scope`".
1331 pub struct FreeRegion {
1332 pub scope: region::CodeExtent,
1333 pub bound_region: BoundRegion
1336 #[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
1337 RustcEncodable, RustcDecodable, Show, Copy)]
1338 pub enum BoundRegion {
1339 /// An anonymous region parameter for a given fn (&T)
1342 /// Named region parameters for functions (a in &'a T)
1344 /// The def-id is needed to distinguish free regions in
1345 /// the event of shadowing.
1346 BrNamed(ast::DefId, ast::Name),
1348 /// Fresh bound identifiers created during GLB computations.
1351 // Anonymous region for the implicit env pointer parameter
1356 // NB: If you change this, you'll probably want to change the corresponding
1357 // AST structure in libsyntax/ast.rs as well.
1358 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1359 pub enum sty<'tcx> {
1363 ty_uint(ast::UintTy),
1364 ty_float(ast::FloatTy),
1365 /// Substs here, possibly against intuition, *may* contain `ty_param`s.
1366 /// That is, even after substitution it is possible that there are type
1367 /// variables. This happens when the `ty_enum` corresponds to an enum
1368 /// definition and not a concrete use of it. To get the correct `ty_enum`
1369 /// from the tcx, use the `NodeId` from the `ast::Ty` and look it up in
1370 /// the `ast_ty_to_ty_cache`. This is probably true for `ty_struct` as
1372 ty_enum(DefId, &'tcx Substs<'tcx>),
1375 ty_vec(Ty<'tcx>, Option<uint>), // Second field is length.
1377 ty_rptr(&'tcx Region, mt<'tcx>),
1379 // If the def-id is Some(_), then this is the type of a specific
1380 // fn item. Otherwise, if None(_), it a fn pointer type.
1381 ty_bare_fn(Option<DefId>, &'tcx BareFnTy<'tcx>),
1383 ty_trait(Box<TyTrait<'tcx>>),
1384 ty_struct(DefId, &'tcx Substs<'tcx>),
1386 ty_unboxed_closure(DefId, &'tcx Region, &'tcx Substs<'tcx>),
1388 ty_tup(Vec<Ty<'tcx>>),
1390 ty_projection(ProjectionTy<'tcx>),
1391 ty_param(ParamTy), // type parameter
1393 ty_open(Ty<'tcx>), // A deref'ed fat pointer, i.e., a dynamically sized value
1394 // and its size. Only ever used in trans. It is not necessary
1395 // earlier since we don't need to distinguish a DST with its
1396 // size (e.g., in a deref) vs a DST with the size elsewhere (
1397 // e.g., in a field).
1399 ty_infer(InferTy), // something used only during inference/typeck
1400 ty_err, // Also only used during inference/typeck, to represent
1401 // the type of an erroneous expression (helps cut down
1402 // on non-useful type error messages)
1405 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1406 pub struct TyTrait<'tcx> {
1407 pub principal: ty::PolyTraitRef<'tcx>,
1408 pub bounds: ExistentialBounds<'tcx>,
1411 impl<'tcx> TyTrait<'tcx> {
1412 pub fn principal_def_id(&self) -> ast::DefId {
1413 self.principal.0.def_id
1416 /// Object types don't have a self-type specified. Therefore, when
1417 /// we convert the principal trait-ref into a normal trait-ref,
1418 /// you must give *some* self-type. A common choice is `mk_err()`
1419 /// or some skolemized type.
1420 pub fn principal_trait_ref_with_self_ty(&self,
1423 -> ty::PolyTraitRef<'tcx>
1425 // otherwise the escaping regions would be captured by the binder
1426 assert!(!self_ty.has_escaping_regions());
1428 ty::Binder(Rc::new(ty::TraitRef {
1429 def_id: self.principal.0.def_id,
1430 substs: tcx.mk_substs(self.principal.0.substs.with_self_ty(self_ty)),
1434 pub fn projection_bounds_with_self_ty(&self,
1437 -> Vec<ty::PolyProjectionPredicate<'tcx>>
1439 // otherwise the escaping regions would be captured by the binders
1440 assert!(!self_ty.has_escaping_regions());
1442 self.bounds.projection_bounds.iter()
1443 .map(|in_poly_projection_predicate| {
1444 let in_projection_ty = &in_poly_projection_predicate.0.projection_ty;
1445 let substs = tcx.mk_substs(in_projection_ty.trait_ref.substs.with_self_ty(self_ty));
1447 Rc::new(ty::TraitRef::new(in_projection_ty.trait_ref.def_id,
1449 let projection_ty = ty::ProjectionTy {
1450 trait_ref: trait_ref,
1451 item_name: in_projection_ty.item_name
1453 ty::Binder(ty::ProjectionPredicate {
1454 projection_ty: projection_ty,
1455 ty: in_poly_projection_predicate.0.ty
1462 /// A complete reference to a trait. These take numerous guises in syntax,
1463 /// but perhaps the most recognizable form is in a where clause:
1467 /// This would be represented by a trait-reference where the def-id is the
1468 /// def-id for the trait `Foo` and the substs defines `T` as parameter 0 in the
1469 /// `SelfSpace` and `U` as parameter 0 in the `TypeSpace`.
1471 /// Trait references also appear in object types like `Foo<U>`, but in
1472 /// that case the `Self` parameter is absent from the substitutions.
1474 /// Note that a `TraitRef` introduces a level of region binding, to
1475 /// account for higher-ranked trait bounds like `T : for<'a> Foo<&'a
1476 /// U>` or higher-ranked object types.
1477 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1478 pub struct TraitRef<'tcx> {
1480 pub substs: &'tcx Substs<'tcx>,
1483 pub type PolyTraitRef<'tcx> = Binder<Rc<TraitRef<'tcx>>>;
1485 impl<'tcx> PolyTraitRef<'tcx> {
1486 pub fn self_ty(&self) -> Ty<'tcx> {
1490 pub fn def_id(&self) -> ast::DefId {
1494 pub fn substs(&self) -> &'tcx Substs<'tcx> {
1495 // FIXME(#20664) every use of this fn is probably a bug, it should yield Binder<>
1499 pub fn input_types(&self) -> &[Ty<'tcx>] {
1500 // FIXME(#20664) every use of this fn is probably a bug, it should yield Binder<>
1501 self.0.input_types()
1504 pub fn to_poly_trait_predicate(&self) -> PolyTraitPredicate<'tcx> {
1505 // Note that we preserve binding levels
1506 Binder(TraitPredicate { trait_ref: self.0.clone() })
1510 /// Binder is a binder for higher-ranked lifetimes. It is part of the
1511 /// compiler's representation for things like `for<'a> Fn(&'a int)`
1512 /// (which would be represented by the type `PolyTraitRef ==
1513 /// Binder<TraitRef>`). Note that when we skolemize, instantiate,
1514 /// erase, or otherwise "discharge" these bound reons, we change the
1515 /// type from `Binder<T>` to just `T` (see
1516 /// e.g. `liberate_late_bound_regions`).
1517 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1518 pub struct Binder<T>(pub T);
1520 #[derive(Clone, Copy, PartialEq)]
1521 pub enum IntVarValue {
1522 IntType(ast::IntTy),
1523 UintType(ast::UintTy),
1526 #[derive(Clone, Copy, Show)]
1527 pub enum terr_vstore_kind {
1534 #[derive(Clone, Copy, Show)]
1535 pub struct expected_found<T> {
1540 // Data structures used in type unification
1541 #[derive(Clone, Copy, Show)]
1542 pub enum type_err<'tcx> {
1544 terr_unsafety_mismatch(expected_found<ast::Unsafety>),
1545 terr_onceness_mismatch(expected_found<Onceness>),
1546 terr_abi_mismatch(expected_found<abi::Abi>),
1548 terr_sigil_mismatch(expected_found<TraitStore>),
1549 terr_box_mutability,
1550 terr_ptr_mutability,
1551 terr_ref_mutability,
1552 terr_vec_mutability,
1553 terr_tuple_size(expected_found<uint>),
1554 terr_fixed_array_size(expected_found<uint>),
1555 terr_ty_param_size(expected_found<uint>),
1557 terr_regions_does_not_outlive(Region, Region),
1558 terr_regions_not_same(Region, Region),
1559 terr_regions_no_overlap(Region, Region),
1560 terr_regions_insufficiently_polymorphic(BoundRegion, Region),
1561 terr_regions_overly_polymorphic(BoundRegion, Region),
1562 terr_trait_stores_differ(terr_vstore_kind, expected_found<TraitStore>),
1563 terr_sorts(expected_found<Ty<'tcx>>),
1564 terr_integer_as_char,
1565 terr_int_mismatch(expected_found<IntVarValue>),
1566 terr_float_mismatch(expected_found<ast::FloatTy>),
1567 terr_traits(expected_found<ast::DefId>),
1568 terr_builtin_bounds(expected_found<BuiltinBounds>),
1569 terr_variadic_mismatch(expected_found<bool>),
1571 terr_convergence_mismatch(expected_found<bool>),
1572 terr_projection_name_mismatched(expected_found<ast::Name>),
1573 terr_projection_bounds_length(expected_found<uint>),
1576 /// Bounds suitable for a named type parameter like `A` in `fn foo<A>`
1577 /// as well as the existential type parameter in an object type.
1578 #[derive(PartialEq, Eq, Hash, Clone, Show)]
1579 pub struct ParamBounds<'tcx> {
1580 pub region_bounds: Vec<ty::Region>,
1581 pub builtin_bounds: BuiltinBounds,
1582 pub trait_bounds: Vec<PolyTraitRef<'tcx>>,
1583 pub projection_bounds: Vec<PolyProjectionPredicate<'tcx>>,
1586 /// Bounds suitable for an existentially quantified type parameter
1587 /// such as those that appear in object types or closure types. The
1588 /// major difference between this case and `ParamBounds` is that
1589 /// general purpose trait bounds are omitted and there must be
1590 /// *exactly one* region.
1591 #[derive(PartialEq, Eq, Hash, Clone, Show)]
1592 pub struct ExistentialBounds<'tcx> {
1593 pub region_bound: ty::Region,
1594 pub builtin_bounds: BuiltinBounds,
1595 pub projection_bounds: Vec<PolyProjectionPredicate<'tcx>>,
1598 pub type BuiltinBounds = EnumSet<BuiltinBound>;
1600 #[derive(Clone, RustcEncodable, PartialEq, Eq, RustcDecodable, Hash,
1603 pub enum BuiltinBound {
1610 pub fn empty_builtin_bounds() -> BuiltinBounds {
1614 pub fn all_builtin_bounds() -> BuiltinBounds {
1615 let mut set = EnumSet::new();
1616 set.insert(BoundSend);
1617 set.insert(BoundSized);
1618 set.insert(BoundSync);
1622 /// An existential bound that does not implement any traits.
1623 pub fn region_existential_bound<'tcx>(r: ty::Region) -> ExistentialBounds<'tcx> {
1624 ty::ExistentialBounds { region_bound: r,
1625 builtin_bounds: empty_builtin_bounds(),
1626 projection_bounds: Vec::new() }
1629 impl CLike for BuiltinBound {
1630 fn to_uint(&self) -> uint {
1633 fn from_uint(v: uint) -> BuiltinBound {
1634 unsafe { mem::transmute(v) }
1638 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1643 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1648 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1649 pub struct FloatVid {
1653 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
1654 pub struct RegionVid {
1658 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1664 /// A `FreshTy` is one that is generated as a replacement for an
1665 /// unbound type variable. This is convenient for caching etc. See
1666 /// `middle::infer::freshen` for more details.
1669 // FIXME -- once integral fallback is impl'd, we should remove
1670 // this type. It's only needed to prevent spurious errors for
1671 // integers whose type winds up never being constrained.
1675 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Show, Copy)]
1676 pub enum UnconstrainedNumeric {
1683 #[derive(Clone, RustcEncodable, RustcDecodable, Eq, Hash, Show, Copy)]
1684 pub enum InferRegion {
1686 ReSkolemized(u32, BoundRegion)
1689 impl cmp::PartialEq for InferRegion {
1690 fn eq(&self, other: &InferRegion) -> bool {
1691 match ((*self), *other) {
1692 (ReVar(rva), ReVar(rvb)) => {
1695 (ReSkolemized(rva, _), ReSkolemized(rvb, _)) => {
1701 fn ne(&self, other: &InferRegion) -> bool {
1702 !((*self) == (*other))
1706 impl fmt::Debug for TyVid {
1707 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result{
1708 write!(f, "_#{}t", self.index)
1712 impl fmt::Debug for IntVid {
1713 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1714 write!(f, "_#{}i", self.index)
1718 impl fmt::Debug for FloatVid {
1719 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1720 write!(f, "_#{}f", self.index)
1724 impl fmt::Debug for RegionVid {
1725 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1726 write!(f, "'_#{}r", self.index)
1730 impl<'tcx> fmt::Debug for FnSig<'tcx> {
1731 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1732 write!(f, "({:?}; variadic: {})->{:?}", self.inputs, self.variadic, self.output)
1736 impl fmt::Debug for InferTy {
1737 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1739 TyVar(ref v) => v.fmt(f),
1740 IntVar(ref v) => v.fmt(f),
1741 FloatVar(ref v) => v.fmt(f),
1742 FreshTy(v) => write!(f, "FreshTy({:?})", v),
1743 FreshIntTy(v) => write!(f, "FreshIntTy({:?})", v),
1748 impl fmt::Debug for IntVarValue {
1749 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1751 IntType(ref v) => v.fmt(f),
1752 UintType(ref v) => v.fmt(f),
1757 #[derive(Clone, Show)]
1758 pub struct TypeParameterDef<'tcx> {
1759 pub name: ast::Name,
1760 pub def_id: ast::DefId,
1761 pub space: subst::ParamSpace,
1763 pub bounds: ParamBounds<'tcx>,
1764 pub default: Option<Ty<'tcx>>,
1767 #[derive(RustcEncodable, RustcDecodable, Clone, Show)]
1768 pub struct RegionParameterDef {
1769 pub name: ast::Name,
1770 pub def_id: ast::DefId,
1771 pub space: subst::ParamSpace,
1773 pub bounds: Vec<ty::Region>,
1776 impl RegionParameterDef {
1777 pub fn to_early_bound_region(&self) -> ty::Region {
1778 ty::ReEarlyBound(self.def_id.node, self.space, self.index, self.name)
1782 /// Information about the formal type/lifetime parameters associated
1783 /// with an item or method. Analogous to ast::Generics.
1784 #[derive(Clone, Show)]
1785 pub struct Generics<'tcx> {
1786 pub types: VecPerParamSpace<TypeParameterDef<'tcx>>,
1787 pub regions: VecPerParamSpace<RegionParameterDef>,
1788 pub predicates: VecPerParamSpace<Predicate<'tcx>>,
1791 impl<'tcx> Generics<'tcx> {
1792 pub fn empty() -> Generics<'tcx> {
1794 types: VecPerParamSpace::empty(),
1795 regions: VecPerParamSpace::empty(),
1796 predicates: VecPerParamSpace::empty(),
1800 pub fn has_type_params(&self, space: subst::ParamSpace) -> bool {
1801 !self.types.is_empty_in(space)
1804 pub fn has_region_params(&self, space: subst::ParamSpace) -> bool {
1805 !self.regions.is_empty_in(space)
1808 pub fn is_empty(&self) -> bool {
1809 self.types.is_empty() && self.regions.is_empty()
1812 pub fn to_bounds(&self, tcx: &ty::ctxt<'tcx>, substs: &Substs<'tcx>)
1813 -> GenericBounds<'tcx> {
1815 predicates: self.predicates.subst(tcx, substs),
1820 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1821 pub enum Predicate<'tcx> {
1822 /// Corresponds to `where Foo : Bar<A,B,C>`. `Foo` here would be
1823 /// the `Self` type of the trait reference and `A`, `B`, and `C`
1824 /// would be the parameters in the `TypeSpace`.
1825 Trait(PolyTraitPredicate<'tcx>),
1827 /// where `T1 == T2`.
1828 Equate(PolyEquatePredicate<'tcx>),
1831 RegionOutlives(PolyRegionOutlivesPredicate),
1834 TypeOutlives(PolyTypeOutlivesPredicate<'tcx>),
1836 /// where <T as TraitRef>::Name == X, approximately.
1837 /// See `ProjectionPredicate` struct for details.
1838 Projection(PolyProjectionPredicate<'tcx>),
1841 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1842 pub struct TraitPredicate<'tcx> {
1843 pub trait_ref: Rc<TraitRef<'tcx>>
1845 pub type PolyTraitPredicate<'tcx> = ty::Binder<TraitPredicate<'tcx>>;
1847 impl<'tcx> TraitPredicate<'tcx> {
1848 pub fn def_id(&self) -> ast::DefId {
1849 self.trait_ref.def_id
1852 pub fn input_types(&self) -> &[Ty<'tcx>] {
1853 self.trait_ref.substs.types.as_slice()
1856 pub fn self_ty(&self) -> Ty<'tcx> {
1857 self.trait_ref.self_ty()
1861 impl<'tcx> PolyTraitPredicate<'tcx> {
1862 pub fn def_id(&self) -> ast::DefId {
1867 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1868 pub struct EquatePredicate<'tcx>(pub Ty<'tcx>, pub Ty<'tcx>); // `0 == 1`
1869 pub type PolyEquatePredicate<'tcx> = ty::Binder<EquatePredicate<'tcx>>;
1871 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1872 pub struct OutlivesPredicate<A,B>(pub A, pub B); // `A : B`
1873 pub type PolyOutlivesPredicate<A,B> = ty::Binder<OutlivesPredicate<A,B>>;
1874 pub type PolyRegionOutlivesPredicate = PolyOutlivesPredicate<ty::Region, ty::Region>;
1875 pub type PolyTypeOutlivesPredicate<'tcx> = PolyOutlivesPredicate<Ty<'tcx>, ty::Region>;
1877 /// This kind of predicate has no *direct* correspondent in the
1878 /// syntax, but it roughly corresponds to the syntactic forms:
1880 /// 1. `T : TraitRef<..., Item=Type>`
1881 /// 2. `<T as TraitRef<...>>::Item == Type` (NYI)
1883 /// In particular, form #1 is "desugared" to the combination of a
1884 /// normal trait predicate (`T : TraitRef<...>`) and one of these
1885 /// predicates. Form #2 is a broader form in that it also permits
1886 /// equality between arbitrary types. Processing an instance of Form
1887 /// #2 eventually yields one of these `ProjectionPredicate`
1888 /// instances to normalize the LHS.
1889 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1890 pub struct ProjectionPredicate<'tcx> {
1891 pub projection_ty: ProjectionTy<'tcx>,
1895 pub type PolyProjectionPredicate<'tcx> = Binder<ProjectionPredicate<'tcx>>;
1897 impl<'tcx> PolyProjectionPredicate<'tcx> {
1898 pub fn item_name(&self) -> ast::Name {
1899 self.0.projection_ty.item_name // safe to skip the binder to access a name
1902 pub fn sort_key(&self) -> (ast::DefId, ast::Name) {
1903 self.0.projection_ty.sort_key()
1907 /// Represents the projection of an associated type. In explicit UFCS
1908 /// form this would be written `<T as Trait<..>>::N`.
1909 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1910 pub struct ProjectionTy<'tcx> {
1911 /// The trait reference `T as Trait<..>`.
1912 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
1914 /// The name `N` of the associated type.
1915 pub item_name: ast::Name,
1918 impl<'tcx> ProjectionTy<'tcx> {
1919 pub fn sort_key(&self) -> (ast::DefId, ast::Name) {
1920 (self.trait_ref.def_id, self.item_name)
1924 pub trait ToPolyTraitRef<'tcx> {
1925 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx>;
1928 impl<'tcx> ToPolyTraitRef<'tcx> for Rc<TraitRef<'tcx>> {
1929 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1930 assert!(!self.has_escaping_regions());
1931 ty::Binder(self.clone())
1935 impl<'tcx> ToPolyTraitRef<'tcx> for PolyTraitPredicate<'tcx> {
1936 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1937 // We are just preserving the binder levels here
1938 ty::Binder(self.0.trait_ref.clone())
1942 impl<'tcx> ToPolyTraitRef<'tcx> for PolyProjectionPredicate<'tcx> {
1943 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1944 // Note: unlike with TraitRef::to_poly_trait_ref(),
1945 // self.0.trait_ref is permitted to have escaping regions.
1946 // This is because here `self` has a `Binder` and so does our
1947 // return value, so we are preserving the number of binding
1949 ty::Binder(self.0.projection_ty.trait_ref.clone())
1953 pub trait AsPredicate<'tcx> {
1954 fn as_predicate(&self) -> Predicate<'tcx>;
1957 impl<'tcx> AsPredicate<'tcx> for Rc<TraitRef<'tcx>> {
1958 fn as_predicate(&self) -> Predicate<'tcx> {
1959 // we're about to add a binder, so let's check that we don't
1960 // accidentally capture anything, or else that might be some
1961 // weird debruijn accounting.
1962 assert!(!self.has_escaping_regions());
1964 ty::Predicate::Trait(ty::Binder(ty::TraitPredicate {
1965 trait_ref: self.clone()
1970 impl<'tcx> AsPredicate<'tcx> for PolyTraitRef<'tcx> {
1971 fn as_predicate(&self) -> Predicate<'tcx> {
1972 ty::Predicate::Trait(self.to_poly_trait_predicate())
1976 impl<'tcx> AsPredicate<'tcx> for PolyEquatePredicate<'tcx> {
1977 fn as_predicate(&self) -> Predicate<'tcx> {
1978 Predicate::Equate(self.clone())
1982 impl<'tcx> AsPredicate<'tcx> for PolyRegionOutlivesPredicate {
1983 fn as_predicate(&self) -> Predicate<'tcx> {
1984 Predicate::RegionOutlives(self.clone())
1988 impl<'tcx> AsPredicate<'tcx> for PolyTypeOutlivesPredicate<'tcx> {
1989 fn as_predicate(&self) -> Predicate<'tcx> {
1990 Predicate::TypeOutlives(self.clone())
1994 impl<'tcx> AsPredicate<'tcx> for PolyProjectionPredicate<'tcx> {
1995 fn as_predicate(&self) -> Predicate<'tcx> {
1996 Predicate::Projection(self.clone())
2000 impl<'tcx> Predicate<'tcx> {
2001 pub fn has_escaping_regions(&self) -> bool {
2003 Predicate::Trait(ref trait_ref) => trait_ref.has_escaping_regions(),
2004 Predicate::Equate(ref p) => p.has_escaping_regions(),
2005 Predicate::RegionOutlives(ref p) => p.has_escaping_regions(),
2006 Predicate::TypeOutlives(ref p) => p.has_escaping_regions(),
2007 Predicate::Projection(ref p) => p.has_escaping_regions(),
2011 pub fn to_opt_poly_trait_ref(&self) -> Option<PolyTraitRef<'tcx>> {
2013 Predicate::Trait(ref t) => {
2014 Some(t.to_poly_trait_ref())
2016 Predicate::Projection(..) |
2017 Predicate::Equate(..) |
2018 Predicate::RegionOutlives(..) |
2019 Predicate::TypeOutlives(..) => {
2026 /// Represents the bounds declared on a particular set of type
2027 /// parameters. Should eventually be generalized into a flag list of
2028 /// where clauses. You can obtain a `GenericBounds` list from a
2029 /// `Generics` by using the `to_bounds` method. Note that this method
2030 /// reflects an important semantic invariant of `GenericBounds`: while
2031 /// the bounds in a `Generics` are expressed in terms of the bound type
2032 /// parameters of the impl/trait/whatever, a `GenericBounds` instance
2033 /// represented a set of bounds for some particular instantiation,
2034 /// meaning that the generic parameters have been substituted with
2039 /// struct Foo<T,U:Bar<T>> { ... }
2041 /// Here, the `Generics` for `Foo` would contain a list of bounds like
2042 /// `[[], [U:Bar<T>]]`. Now if there were some particular reference
2043 /// like `Foo<int,uint>`, then the `GenericBounds` would be `[[],
2044 /// [uint:Bar<int>]]`.
2045 #[derive(Clone, Show)]
2046 pub struct GenericBounds<'tcx> {
2047 pub predicates: VecPerParamSpace<Predicate<'tcx>>,
2050 impl<'tcx> GenericBounds<'tcx> {
2051 pub fn empty() -> GenericBounds<'tcx> {
2052 GenericBounds { predicates: VecPerParamSpace::empty() }
2055 pub fn has_escaping_regions(&self) -> bool {
2056 self.predicates.any(|p| p.has_escaping_regions())
2059 pub fn is_empty(&self) -> bool {
2060 self.predicates.is_empty()
2064 impl<'tcx> TraitRef<'tcx> {
2065 pub fn new(def_id: ast::DefId, substs: &'tcx Substs<'tcx>) -> TraitRef<'tcx> {
2066 TraitRef { def_id: def_id, substs: substs }
2069 pub fn self_ty(&self) -> Ty<'tcx> {
2070 self.substs.self_ty().unwrap()
2073 pub fn input_types(&self) -> &[Ty<'tcx>] {
2074 // Select only the "input types" from a trait-reference. For
2075 // now this is all the types that appear in the
2076 // trait-reference, but it should eventually exclude
2077 // associated types.
2078 self.substs.types.as_slice()
2082 /// When type checking, we use the `ParameterEnvironment` to track
2083 /// details about the type/lifetime parameters that are in scope.
2084 /// It primarily stores the bounds information.
2086 /// Note: This information might seem to be redundant with the data in
2087 /// `tcx.ty_param_defs`, but it is not. That table contains the
2088 /// parameter definitions from an "outside" perspective, but this
2089 /// struct will contain the bounds for a parameter as seen from inside
2090 /// the function body. Currently the only real distinction is that
2091 /// bound lifetime parameters are replaced with free ones, but in the
2092 /// future I hope to refine the representation of types so as to make
2093 /// more distinctions clearer.
2095 pub struct ParameterEnvironment<'a, 'tcx:'a> {
2096 pub tcx: &'a ctxt<'tcx>,
2098 /// A substitution that can be applied to move from
2099 /// the "outer" view of a type or method to the "inner" view.
2100 /// In general, this means converting from bound parameters to
2101 /// free parameters. Since we currently represent bound/free type
2102 /// parameters in the same way, this only has an effect on regions.
2103 pub free_substs: Substs<'tcx>,
2105 /// Each type parameter has an implicit region bound that
2106 /// indicates it must outlive at least the function body (the user
2107 /// may specify stronger requirements). This field indicates the
2108 /// region of the callee.
2109 pub implicit_region_bound: ty::Region,
2111 /// Obligations that the caller must satisfy. This is basically
2112 /// the set of bounds on the in-scope type parameters, translated
2113 /// into Obligations.
2114 pub caller_bounds: ty::GenericBounds<'tcx>,
2116 /// Caches the results of trait selection. This cache is used
2117 /// for things that have to do with the parameters in scope.
2118 pub selection_cache: traits::SelectionCache<'tcx>,
2121 impl<'a, 'tcx> ParameterEnvironment<'a, 'tcx> {
2122 pub fn for_item(cx: &'a ctxt<'tcx>, id: NodeId) -> ParameterEnvironment<'a, 'tcx> {
2123 match cx.map.find(id) {
2124 Some(ast_map::NodeImplItem(ref impl_item)) => {
2126 ast::MethodImplItem(ref method) => {
2127 let method_def_id = ast_util::local_def(id);
2128 match ty::impl_or_trait_item(cx, method_def_id) {
2129 MethodTraitItem(ref method_ty) => {
2130 let method_generics = &method_ty.generics;
2131 construct_parameter_environment(
2134 method.pe_body().id)
2136 TypeTraitItem(_) => {
2138 .bug("ParameterEnvironment::for_item(): \
2139 can't create a parameter environment \
2140 for type trait items")
2144 ast::TypeImplItem(_) => {
2145 cx.sess.bug("ParameterEnvironment::for_item(): \
2146 can't create a parameter environment \
2147 for type impl items")
2151 Some(ast_map::NodeTraitItem(trait_method)) => {
2152 match *trait_method {
2153 ast::RequiredMethod(ref required) => {
2154 cx.sess.span_bug(required.span,
2155 "ParameterEnvironment::for_item():
2156 can't create a parameter \
2157 environment for required trait \
2160 ast::ProvidedMethod(ref method) => {
2161 let method_def_id = ast_util::local_def(id);
2162 match ty::impl_or_trait_item(cx, method_def_id) {
2163 MethodTraitItem(ref method_ty) => {
2164 let method_generics = &method_ty.generics;
2165 construct_parameter_environment(
2168 method.pe_body().id)
2170 TypeTraitItem(_) => {
2172 .bug("ParameterEnvironment::for_item(): \
2173 can't create a parameter environment \
2174 for type trait items")
2178 ast::TypeTraitItem(_) => {
2179 cx.sess.bug("ParameterEnvironment::from_item(): \
2180 can't create a parameter environment \
2181 for type trait items")
2185 Some(ast_map::NodeItem(item)) => {
2187 ast::ItemFn(_, _, _, _, ref body) => {
2188 // We assume this is a function.
2189 let fn_def_id = ast_util::local_def(id);
2190 let fn_pty = ty::lookup_item_type(cx, fn_def_id);
2192 construct_parameter_environment(cx,
2197 ast::ItemStruct(..) |
2199 ast::ItemConst(..) |
2200 ast::ItemStatic(..) => {
2201 let def_id = ast_util::local_def(id);
2202 let pty = ty::lookup_item_type(cx, def_id);
2203 construct_parameter_environment(cx, &pty.generics, id)
2206 cx.sess.span_bug(item.span,
2207 "ParameterEnvironment::from_item():
2208 can't create a parameter \
2209 environment for this kind of item")
2213 Some(ast_map::NodeExpr(..)) => {
2214 // This is a convenience to allow closures to work.
2215 ParameterEnvironment::for_item(cx, cx.map.get_parent(id))
2218 cx.sess.bug(&format!("ParameterEnvironment::from_item(): \
2219 `{}` is not an item",
2220 cx.map.node_to_string(id))[])
2226 /// A "type scheme", in ML terminology, is a type combined with some
2227 /// set of generic types that the type is, well, generic over. In Rust
2228 /// terms, it is the "type" of a fn item or struct -- this type will
2229 /// include various generic parameters that must be substituted when
2230 /// the item/struct is referenced. That is called converting the type
2231 /// scheme to a monotype.
2233 /// - `generics`: the set of type parameters and their bounds
2234 /// - `ty`: the base types, which may reference the parameters defined
2237 /// Note that TypeSchemes are also sometimes called "polytypes" (and
2238 /// in fact this struct used to carry that name, so you may find some
2239 /// stray references in a comment or something). We try to reserve the
2240 /// "poly" prefix to refer to higher-ranked things, as in
2242 #[derive(Clone, Show)]
2243 pub struct TypeScheme<'tcx> {
2244 pub generics: Generics<'tcx>,
2248 /// As `TypeScheme` but for a trait ref.
2249 pub struct TraitDef<'tcx> {
2250 pub unsafety: ast::Unsafety,
2252 /// Generic type definitions. Note that `Self` is listed in here
2253 /// as having a single bound, the trait itself (e.g., in the trait
2254 /// `Eq`, there is a single bound `Self : Eq`). This is so that
2255 /// default methods get to assume that the `Self` parameters
2256 /// implements the trait.
2257 pub generics: Generics<'tcx>,
2259 /// The "supertrait" bounds.
2260 pub bounds: ParamBounds<'tcx>,
2262 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
2264 /// A list of the associated types defined in this trait. Useful
2265 /// for resolving `X::Foo` type markers.
2266 pub associated_type_names: Vec<ast::Name>,
2269 /// Records the substitutions used to translate the polytype for an
2270 /// item into the monotype of an item reference.
2272 pub struct ItemSubsts<'tcx> {
2273 pub substs: Substs<'tcx>,
2276 /// Records information about each unboxed closure.
2278 pub struct UnboxedClosure<'tcx> {
2279 /// The type of the unboxed closure.
2280 pub closure_type: ClosureTy<'tcx>,
2281 /// The kind of unboxed closure this is.
2282 pub kind: UnboxedClosureKind,
2285 #[derive(Clone, Copy, PartialEq, Eq, Show)]
2286 pub enum UnboxedClosureKind {
2287 FnUnboxedClosureKind,
2288 FnMutUnboxedClosureKind,
2289 FnOnceUnboxedClosureKind,
2292 impl UnboxedClosureKind {
2293 pub fn trait_did(&self, cx: &ctxt) -> ast::DefId {
2294 let result = match *self {
2295 FnUnboxedClosureKind => cx.lang_items.require(FnTraitLangItem),
2296 FnMutUnboxedClosureKind => {
2297 cx.lang_items.require(FnMutTraitLangItem)
2299 FnOnceUnboxedClosureKind => {
2300 cx.lang_items.require(FnOnceTraitLangItem)
2304 Ok(trait_did) => trait_did,
2305 Err(err) => cx.sess.fatal(&err[]),
2310 pub trait UnboxedClosureTyper<'tcx> {
2311 fn param_env<'a>(&'a self) -> &'a ty::ParameterEnvironment<'a, 'tcx>;
2313 fn unboxed_closure_kind(&self,
2315 -> ty::UnboxedClosureKind;
2317 fn unboxed_closure_type(&self,
2319 substs: &subst::Substs<'tcx>)
2320 -> ty::ClosureTy<'tcx>;
2322 // Returns `None` if the upvar types cannot yet be definitively determined.
2323 fn unboxed_closure_upvars(&self,
2325 substs: &Substs<'tcx>)
2326 -> Option<Vec<UnboxedClosureUpvar<'tcx>>>;
2329 impl<'tcx> CommonTypes<'tcx> {
2330 fn new(arena: &'tcx TypedArena<TyS<'tcx>>,
2331 interner: &mut FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>)
2332 -> CommonTypes<'tcx>
2335 bool: intern_ty(arena, interner, ty_bool),
2336 char: intern_ty(arena, interner, ty_char),
2337 err: intern_ty(arena, interner, ty_err),
2338 int: intern_ty(arena, interner, ty_int(ast::TyIs(false))),
2339 i8: intern_ty(arena, interner, ty_int(ast::TyI8)),
2340 i16: intern_ty(arena, interner, ty_int(ast::TyI16)),
2341 i32: intern_ty(arena, interner, ty_int(ast::TyI32)),
2342 i64: intern_ty(arena, interner, ty_int(ast::TyI64)),
2343 uint: intern_ty(arena, interner, ty_uint(ast::TyUs(false))),
2344 u8: intern_ty(arena, interner, ty_uint(ast::TyU8)),
2345 u16: intern_ty(arena, interner, ty_uint(ast::TyU16)),
2346 u32: intern_ty(arena, interner, ty_uint(ast::TyU32)),
2347 u64: intern_ty(arena, interner, ty_uint(ast::TyU64)),
2348 f32: intern_ty(arena, interner, ty_float(ast::TyF32)),
2349 f64: intern_ty(arena, interner, ty_float(ast::TyF64)),
2354 pub fn mk_ctxt<'tcx>(s: Session,
2355 arenas: &'tcx CtxtArenas<'tcx>,
2357 named_region_map: resolve_lifetime::NamedRegionMap,
2358 map: ast_map::Map<'tcx>,
2359 freevars: RefCell<FreevarMap>,
2360 capture_modes: RefCell<CaptureModeMap>,
2361 region_maps: middle::region::RegionMaps,
2362 lang_items: middle::lang_items::LanguageItems,
2363 stability: stability::Index) -> ctxt<'tcx>
2365 let mut interner = FnvHashMap();
2366 let common_types = CommonTypes::new(&arenas.type_, &mut interner);
2370 interner: RefCell::new(interner),
2371 substs_interner: RefCell::new(FnvHashMap()),
2372 bare_fn_interner: RefCell::new(FnvHashMap()),
2373 region_interner: RefCell::new(FnvHashMap()),
2374 types: common_types,
2375 named_region_map: named_region_map,
2376 item_variance_map: RefCell::new(DefIdMap()),
2377 variance_computed: Cell::new(false),
2380 region_maps: region_maps,
2381 node_types: RefCell::new(FnvHashMap()),
2382 item_substs: RefCell::new(NodeMap()),
2383 trait_refs: RefCell::new(NodeMap()),
2384 trait_defs: RefCell::new(DefIdMap()),
2385 object_cast_map: RefCell::new(NodeMap()),
2387 intrinsic_defs: RefCell::new(DefIdMap()),
2389 tcache: RefCell::new(DefIdMap()),
2390 rcache: RefCell::new(FnvHashMap()),
2391 short_names_cache: RefCell::new(FnvHashMap()),
2392 tc_cache: RefCell::new(FnvHashMap()),
2393 ast_ty_to_ty_cache: RefCell::new(NodeMap()),
2394 enum_var_cache: RefCell::new(DefIdMap()),
2395 impl_or_trait_items: RefCell::new(DefIdMap()),
2396 trait_item_def_ids: RefCell::new(DefIdMap()),
2397 trait_items_cache: RefCell::new(DefIdMap()),
2398 impl_trait_cache: RefCell::new(DefIdMap()),
2399 ty_param_defs: RefCell::new(NodeMap()),
2400 adjustments: RefCell::new(NodeMap()),
2401 normalized_cache: RefCell::new(FnvHashMap()),
2402 lang_items: lang_items,
2403 provided_method_sources: RefCell::new(DefIdMap()),
2404 struct_fields: RefCell::new(DefIdMap()),
2405 destructor_for_type: RefCell::new(DefIdMap()),
2406 destructors: RefCell::new(DefIdSet()),
2407 trait_impls: RefCell::new(DefIdMap()),
2408 inherent_impls: RefCell::new(DefIdMap()),
2409 impl_items: RefCell::new(DefIdMap()),
2410 used_unsafe: RefCell::new(NodeSet()),
2411 used_mut_nodes: RefCell::new(NodeSet()),
2412 populated_external_types: RefCell::new(DefIdSet()),
2413 populated_external_traits: RefCell::new(DefIdSet()),
2414 upvar_borrow_map: RefCell::new(FnvHashMap()),
2415 extern_const_statics: RefCell::new(DefIdMap()),
2416 extern_const_variants: RefCell::new(DefIdMap()),
2417 method_map: RefCell::new(FnvHashMap()),
2418 dependency_formats: RefCell::new(FnvHashMap()),
2419 unboxed_closures: RefCell::new(DefIdMap()),
2420 node_lint_levels: RefCell::new(FnvHashMap()),
2421 transmute_restrictions: RefCell::new(Vec::new()),
2422 stability: RefCell::new(stability),
2423 capture_modes: capture_modes,
2424 associated_types: RefCell::new(DefIdMap()),
2425 selection_cache: traits::SelectionCache::new(),
2426 repr_hint_cache: RefCell::new(DefIdMap()),
2427 type_impls_copy_cache: RefCell::new(HashMap::new()),
2428 type_impls_sized_cache: RefCell::new(HashMap::new()),
2429 object_safety_cache: RefCell::new(DefIdMap()),
2433 // Type constructors
2435 impl<'tcx> ctxt<'tcx> {
2436 pub fn mk_substs(&self, substs: Substs<'tcx>) -> &'tcx Substs<'tcx> {
2437 if let Some(substs) = self.substs_interner.borrow().get(&substs) {
2441 let substs = self.arenas.substs.alloc(substs);
2442 self.substs_interner.borrow_mut().insert(substs, substs);
2446 pub fn mk_bare_fn(&self, bare_fn: BareFnTy<'tcx>) -> &'tcx BareFnTy<'tcx> {
2447 if let Some(bare_fn) = self.bare_fn_interner.borrow().get(&bare_fn) {
2451 let bare_fn = self.arenas.bare_fn.alloc(bare_fn);
2452 self.bare_fn_interner.borrow_mut().insert(bare_fn, bare_fn);
2456 pub fn mk_region(&self, region: Region) -> &'tcx Region {
2457 if let Some(region) = self.region_interner.borrow().get(®ion) {
2461 let region = self.arenas.region.alloc(region);
2462 self.region_interner.borrow_mut().insert(region, region);
2466 pub fn unboxed_closure_kind(&self,
2468 -> ty::UnboxedClosureKind
2470 self.unboxed_closures.borrow()[def_id].kind
2473 pub fn unboxed_closure_type(&self,
2475 substs: &subst::Substs<'tcx>)
2476 -> ty::ClosureTy<'tcx>
2478 self.unboxed_closures.borrow()[def_id].closure_type.subst(self, substs)
2482 // Interns a type/name combination, stores the resulting box in cx.interner,
2483 // and returns the box as cast to an unsafe ptr (see comments for Ty above).
2484 pub fn mk_t<'tcx>(cx: &ctxt<'tcx>, st: sty<'tcx>) -> Ty<'tcx> {
2485 let mut interner = cx.interner.borrow_mut();
2486 intern_ty(&cx.arenas.type_, &mut *interner, st)
2489 fn intern_ty<'tcx>(type_arena: &'tcx TypedArena<TyS<'tcx>>,
2490 interner: &mut FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>,
2494 match interner.get(&st) {
2495 Some(ty) => return *ty,
2499 let flags = FlagComputation::for_sty(&st);
2501 let ty = type_arena.alloc(TyS {
2504 region_depth: flags.depth,
2507 debug!("Interned type: {:?} Pointer: {:?}",
2508 ty, ty as *const _);
2510 interner.insert(InternedTy { ty: ty }, ty);
2515 struct FlagComputation {
2518 // maximum depth of any bound region that we have seen thus far
2522 impl FlagComputation {
2523 fn new() -> FlagComputation {
2524 FlagComputation { flags: NO_TYPE_FLAGS, depth: 0 }
2527 fn for_sty(st: &sty) -> FlagComputation {
2528 let mut result = FlagComputation::new();
2533 fn add_flags(&mut self, flags: TypeFlags) {
2534 self.flags = self.flags | flags;
2537 fn add_depth(&mut self, depth: u32) {
2538 if depth > self.depth {
2543 /// Adds the flags/depth from a set of types that appear within the current type, but within a
2545 fn add_bound_computation(&mut self, computation: &FlagComputation) {
2546 self.add_flags(computation.flags);
2548 // The types that contributed to `computation` occured within
2549 // a region binder, so subtract one from the region depth
2550 // within when adding the depth to `self`.
2551 let depth = computation.depth;
2553 self.add_depth(depth - 1);
2557 fn add_sty(&mut self, st: &sty) {
2567 // You might think that we could just return ty_err for
2568 // any type containing ty_err as a component, and get
2569 // rid of the HAS_TY_ERR flag -- likewise for ty_bot (with
2570 // the exception of function types that return bot).
2571 // But doing so caused sporadic memory corruption, and
2572 // neither I (tjc) nor nmatsakis could figure out why,
2573 // so we're doing it this way.
2575 self.add_flags(HAS_TY_ERR)
2578 &ty_param(ref p) => {
2579 if p.space == subst::SelfSpace {
2580 self.add_flags(HAS_SELF);
2582 self.add_flags(HAS_PARAMS);
2586 &ty_unboxed_closure(_, region, substs) => {
2587 self.add_region(*region);
2588 self.add_substs(substs);
2592 self.add_flags(HAS_TY_INFER)
2595 &ty_enum(_, substs) | &ty_struct(_, substs) => {
2596 self.add_substs(substs);
2599 &ty_projection(ref data) => {
2600 self.add_flags(HAS_PROJECTION);
2601 self.add_projection_ty(data);
2604 &ty_trait(box TyTrait { ref principal, ref bounds }) => {
2605 let mut computation = FlagComputation::new();
2606 computation.add_substs(principal.0.substs);
2607 for projection_bound in bounds.projection_bounds.iter() {
2608 let mut proj_computation = FlagComputation::new();
2609 proj_computation.add_projection_predicate(&projection_bound.0);
2610 computation.add_bound_computation(&proj_computation);
2612 self.add_bound_computation(&computation);
2614 self.add_bounds(bounds);
2617 &ty_uniq(tt) | &ty_vec(tt, _) | &ty_open(tt) => {
2625 &ty_rptr(r, ref m) => {
2626 self.add_region(*r);
2630 &ty_tup(ref ts) => {
2631 self.add_tys(&ts[]);
2634 &ty_bare_fn(_, ref f) => {
2635 self.add_fn_sig(&f.sig);
2640 fn add_ty(&mut self, ty: Ty) {
2641 self.add_flags(ty.flags);
2642 self.add_depth(ty.region_depth);
2645 fn add_tys(&mut self, tys: &[Ty]) {
2646 for &ty in tys.iter() {
2651 fn add_fn_sig(&mut self, fn_sig: &PolyFnSig) {
2652 let mut computation = FlagComputation::new();
2654 computation.add_tys(&fn_sig.0.inputs[]);
2656 if let ty::FnConverging(output) = fn_sig.0.output {
2657 computation.add_ty(output);
2660 self.add_bound_computation(&computation);
2663 fn add_region(&mut self, r: Region) {
2664 self.add_flags(HAS_REGIONS);
2666 ty::ReInfer(_) => { self.add_flags(HAS_RE_INFER); }
2667 ty::ReLateBound(debruijn, _) => {
2668 self.add_flags(HAS_RE_LATE_BOUND);
2669 self.add_depth(debruijn.depth);
2675 fn add_projection_predicate(&mut self, projection_predicate: &ProjectionPredicate) {
2676 self.add_projection_ty(&projection_predicate.projection_ty);
2677 self.add_ty(projection_predicate.ty);
2680 fn add_projection_ty(&mut self, projection_ty: &ProjectionTy) {
2681 self.add_substs(projection_ty.trait_ref.substs);
2684 fn add_substs(&mut self, substs: &Substs) {
2685 self.add_tys(substs.types.as_slice());
2686 match substs.regions {
2687 subst::ErasedRegions => {}
2688 subst::NonerasedRegions(ref regions) => {
2689 for &r in regions.iter() {
2696 fn add_bounds(&mut self, bounds: &ExistentialBounds) {
2697 self.add_region(bounds.region_bound);
2701 pub fn mk_mach_int<'tcx>(tcx: &ctxt<'tcx>, tm: ast::IntTy) -> Ty<'tcx> {
2703 ast::TyIs(_) => tcx.types.int,
2704 ast::TyI8 => tcx.types.i8,
2705 ast::TyI16 => tcx.types.i16,
2706 ast::TyI32 => tcx.types.i32,
2707 ast::TyI64 => tcx.types.i64,
2711 pub fn mk_mach_uint<'tcx>(tcx: &ctxt<'tcx>, tm: ast::UintTy) -> Ty<'tcx> {
2713 ast::TyUs(_) => tcx.types.uint,
2714 ast::TyU8 => tcx.types.u8,
2715 ast::TyU16 => tcx.types.u16,
2716 ast::TyU32 => tcx.types.u32,
2717 ast::TyU64 => tcx.types.u64,
2721 pub fn mk_mach_float<'tcx>(tcx: &ctxt<'tcx>, tm: ast::FloatTy) -> Ty<'tcx> {
2723 ast::TyF32 => tcx.types.f32,
2724 ast::TyF64 => tcx.types.f64,
2728 pub fn mk_str<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2732 pub fn mk_str_slice<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, m: ast::Mutability) -> Ty<'tcx> {
2735 ty: mk_t(cx, ty_str),
2740 pub fn mk_enum<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId, substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
2741 // take a copy of substs so that we own the vectors inside
2742 mk_t(cx, ty_enum(did, substs))
2745 pub fn mk_uniq<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_uniq(ty)) }
2747 pub fn mk_ptr<'tcx>(cx: &ctxt<'tcx>, tm: mt<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_ptr(tm)) }
2749 pub fn mk_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, tm: mt<'tcx>) -> Ty<'tcx> {
2750 mk_t(cx, ty_rptr(r, tm))
2753 pub fn mk_mut_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
2754 mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutMutable})
2756 pub fn mk_imm_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
2757 mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutImmutable})
2760 pub fn mk_mut_ptr<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
2761 mk_ptr(cx, mt {ty: ty, mutbl: ast::MutMutable})
2764 pub fn mk_imm_ptr<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
2765 mk_ptr(cx, mt {ty: ty, mutbl: ast::MutImmutable})
2768 pub fn mk_nil_ptr<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2769 mk_ptr(cx, mt {ty: mk_nil(cx), mutbl: ast::MutImmutable})
2772 pub fn mk_vec<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>, sz: Option<uint>) -> Ty<'tcx> {
2773 mk_t(cx, ty_vec(ty, sz))
2776 pub fn mk_slice<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, tm: mt<'tcx>) -> Ty<'tcx> {
2779 ty: mk_vec(cx, tm.ty, None),
2784 pub fn mk_tup<'tcx>(cx: &ctxt<'tcx>, ts: Vec<Ty<'tcx>>) -> Ty<'tcx> {
2785 mk_t(cx, ty_tup(ts))
2788 pub fn mk_nil<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2789 mk_tup(cx, Vec::new())
2792 pub fn mk_bare_fn<'tcx>(cx: &ctxt<'tcx>,
2793 opt_def_id: Option<ast::DefId>,
2794 fty: &'tcx BareFnTy<'tcx>) -> Ty<'tcx> {
2795 mk_t(cx, ty_bare_fn(opt_def_id, fty))
2798 pub fn mk_ctor_fn<'tcx>(cx: &ctxt<'tcx>,
2800 input_tys: &[Ty<'tcx>],
2801 output: Ty<'tcx>) -> Ty<'tcx> {
2802 let input_args = input_tys.iter().map(|ty| *ty).collect();
2805 cx.mk_bare_fn(BareFnTy {
2806 unsafety: ast::Unsafety::Normal,
2808 sig: ty::Binder(FnSig {
2810 output: ty::FnConverging(output),
2816 pub fn mk_trait<'tcx>(cx: &ctxt<'tcx>,
2817 principal: ty::PolyTraitRef<'tcx>,
2818 bounds: ExistentialBounds<'tcx>)
2821 assert!(bound_list_is_sorted(bounds.projection_bounds.as_slice()));
2823 let inner = box TyTrait {
2824 principal: principal,
2827 mk_t(cx, ty_trait(inner))
2830 fn bound_list_is_sorted(bounds: &[ty::PolyProjectionPredicate]) -> bool {
2831 bounds.len() == 0 ||
2832 bounds[1..].iter().enumerate().all(
2833 |(index, bound)| bounds[index].sort_key() <= bound.sort_key())
2836 pub fn sort_bounds_list(bounds: &mut [ty::PolyProjectionPredicate]) {
2837 bounds.sort_by(|a, b| a.sort_key().cmp(&b.sort_key()))
2840 pub fn mk_projection<'tcx>(cx: &ctxt<'tcx>,
2841 trait_ref: Rc<ty::TraitRef<'tcx>>,
2842 item_name: ast::Name)
2844 // take a copy of substs so that we own the vectors inside
2845 let inner = ProjectionTy { trait_ref: trait_ref, item_name: item_name };
2846 mk_t(cx, ty_projection(inner))
2849 pub fn mk_struct<'tcx>(cx: &ctxt<'tcx>, struct_id: ast::DefId,
2850 substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
2851 // take a copy of substs so that we own the vectors inside
2852 mk_t(cx, ty_struct(struct_id, substs))
2855 pub fn mk_unboxed_closure<'tcx>(cx: &ctxt<'tcx>, closure_id: ast::DefId,
2856 region: &'tcx Region, substs: &'tcx Substs<'tcx>)
2858 mk_t(cx, ty_unboxed_closure(closure_id, region, substs))
2861 pub fn mk_var<'tcx>(cx: &ctxt<'tcx>, v: TyVid) -> Ty<'tcx> {
2862 mk_infer(cx, TyVar(v))
2865 pub fn mk_int_var<'tcx>(cx: &ctxt<'tcx>, v: IntVid) -> Ty<'tcx> {
2866 mk_infer(cx, IntVar(v))
2869 pub fn mk_float_var<'tcx>(cx: &ctxt<'tcx>, v: FloatVid) -> Ty<'tcx> {
2870 mk_infer(cx, FloatVar(v))
2873 pub fn mk_infer<'tcx>(cx: &ctxt<'tcx>, it: InferTy) -> Ty<'tcx> {
2874 mk_t(cx, ty_infer(it))
2877 pub fn mk_param<'tcx>(cx: &ctxt<'tcx>,
2878 space: subst::ParamSpace,
2880 name: ast::Name) -> Ty<'tcx> {
2881 mk_t(cx, ty_param(ParamTy { space: space, idx: index, name: name }))
2884 pub fn mk_self_type<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2885 mk_param(cx, subst::SelfSpace, 0, special_idents::type_self.name)
2888 pub fn mk_param_from_def<'tcx>(cx: &ctxt<'tcx>, def: &TypeParameterDef) -> Ty<'tcx> {
2889 mk_param(cx, def.space, def.index, def.name)
2892 pub fn mk_open<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_open(ty)) }
2894 impl<'tcx> TyS<'tcx> {
2895 /// Iterator that walks `self` and any types reachable from
2896 /// `self`, in depth-first order. Note that just walks the types
2897 /// that appear in `self`, it does not descend into the fields of
2898 /// structs or variants. For example:
2902 /// Foo<Bar<int>> => { Foo<Bar<int>>, Bar<int>, int }
2903 /// [int] => { [int], int }
2905 pub fn walk(&'tcx self) -> TypeWalker<'tcx> {
2906 TypeWalker::new(self)
2909 /// Iterator that walks types reachable from `self`, in
2910 /// depth-first order. Note that this is a shallow walk. For
2915 /// Foo<Bar<int>> => { Bar<int>, int }
2916 /// [int] => { int }
2918 pub fn walk_children(&'tcx self) -> TypeWalker<'tcx> {
2919 // Walks type reachable from `self` but not `self
2920 let mut walker = self.walk();
2921 let r = walker.next();
2922 assert_eq!(r, Some(self));
2927 pub fn walk_ty<'tcx, F>(ty_root: Ty<'tcx>, mut f: F)
2928 where F: FnMut(Ty<'tcx>),
2930 for ty in ty_root.walk() {
2935 /// Walks `ty` and any types appearing within `ty`, invoking the
2936 /// callback `f` on each type. If the callback returns false, then the
2937 /// children of the current type are ignored.
2939 /// Note: prefer `ty.walk()` where possible.
2940 pub fn maybe_walk_ty<'tcx,F>(ty_root: Ty<'tcx>, mut f: F)
2941 where F : FnMut(Ty<'tcx>) -> bool
2943 let mut walker = ty_root.walk();
2944 while let Some(ty) = walker.next() {
2946 walker.skip_current_subtree();
2951 // Folds types from the bottom up.
2952 pub fn fold_ty<'tcx, F>(cx: &ctxt<'tcx>, t0: Ty<'tcx>,
2955 F: FnMut(Ty<'tcx>) -> Ty<'tcx>,
2957 let mut f = ty_fold::BottomUpFolder {tcx: cx, fldop: fldop};
2962 pub fn new(space: subst::ParamSpace,
2966 ParamTy { space: space, idx: index, name: name }
2969 pub fn for_self() -> ParamTy {
2970 ParamTy::new(subst::SelfSpace, 0, special_idents::type_self.name)
2973 pub fn for_def(def: &TypeParameterDef) -> ParamTy {
2974 ParamTy::new(def.space, def.index, def.name)
2977 pub fn to_ty<'tcx>(self, tcx: &ty::ctxt<'tcx>) -> Ty<'tcx> {
2978 ty::mk_param(tcx, self.space, self.idx, self.name)
2981 pub fn is_self(&self) -> bool {
2982 self.space == subst::SelfSpace && self.idx == 0
2986 impl<'tcx> ItemSubsts<'tcx> {
2987 pub fn empty() -> ItemSubsts<'tcx> {
2988 ItemSubsts { substs: Substs::empty() }
2991 pub fn is_noop(&self) -> bool {
2992 self.substs.is_noop()
2996 impl<'tcx> ParamBounds<'tcx> {
2997 pub fn empty() -> ParamBounds<'tcx> {
2999 builtin_bounds: empty_builtin_bounds(),
3000 trait_bounds: Vec::new(),
3001 region_bounds: Vec::new(),
3002 projection_bounds: Vec::new(),
3009 pub fn type_is_nil(ty: Ty) -> bool {
3011 ty_tup(ref tys) => tys.is_empty(),
3016 pub fn type_is_error(ty: Ty) -> bool {
3017 ty.flags.intersects(HAS_TY_ERR)
3020 pub fn type_needs_subst(ty: Ty) -> bool {
3021 ty.flags.intersects(NEEDS_SUBST)
3024 pub fn trait_ref_contains_error(tref: &ty::TraitRef) -> bool {
3025 tref.substs.types.any(|&ty| type_is_error(ty))
3028 pub fn type_is_ty_var(ty: Ty) -> bool {
3030 ty_infer(TyVar(_)) => true,
3035 pub fn type_is_bool(ty: Ty) -> bool { ty.sty == ty_bool }
3037 pub fn type_is_self(ty: Ty) -> bool {
3039 ty_param(ref p) => p.space == subst::SelfSpace,
3044 fn type_is_slice(ty: Ty) -> bool {
3046 ty_ptr(mt) | ty_rptr(_, mt) => match mt.ty.sty {
3047 ty_vec(_, None) | ty_str => true,
3054 pub fn type_is_vec(ty: Ty) -> bool {
3057 ty_ptr(mt{ty, ..}) | ty_rptr(_, mt{ty, ..}) |
3058 ty_uniq(ty) => match ty.sty {
3059 ty_vec(_, None) => true,
3066 pub fn type_is_structural(ty: Ty) -> bool {
3068 ty_struct(..) | ty_tup(_) | ty_enum(..) |
3069 ty_vec(_, Some(_)) | ty_unboxed_closure(..) => true,
3070 _ => type_is_slice(ty) | type_is_trait(ty)
3074 pub fn type_is_simd(cx: &ctxt, ty: Ty) -> bool {
3076 ty_struct(did, _) => lookup_simd(cx, did),
3081 pub fn sequence_element_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
3083 ty_vec(ty, _) => ty,
3084 ty_str => mk_mach_uint(cx, ast::TyU8),
3085 ty_open(ty) => sequence_element_type(cx, ty),
3086 _ => cx.sess.bug(&format!("sequence_element_type called on non-sequence value: {}",
3087 ty_to_string(cx, ty))[]),
3091 pub fn simd_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
3093 ty_struct(did, substs) => {
3094 let fields = lookup_struct_fields(cx, did);
3095 lookup_field_type(cx, did, fields[0].id, substs)
3097 _ => panic!("simd_type called on invalid type")
3101 pub fn simd_size(cx: &ctxt, ty: Ty) -> uint {
3103 ty_struct(did, _) => {
3104 let fields = lookup_struct_fields(cx, did);
3107 _ => panic!("simd_size called on invalid type")
3111 pub fn type_is_region_ptr(ty: Ty) -> bool {
3113 ty_rptr(..) => true,
3118 pub fn type_is_unsafe_ptr(ty: Ty) -> bool {
3120 ty_ptr(_) => return true,
3125 pub fn type_is_unique(ty: Ty) -> bool {
3127 ty_uniq(_) => match ty.sty {
3128 ty_trait(..) => false,
3136 A scalar type is one that denotes an atomic datum, with no sub-components.
3137 (A ty_ptr is scalar because it represents a non-managed pointer, so its
3138 contents are abstract to rustc.)
3140 pub fn type_is_scalar(ty: Ty) -> bool {
3142 ty_bool | ty_char | ty_int(_) | ty_float(_) | ty_uint(_) |
3143 ty_infer(IntVar(_)) | ty_infer(FloatVar(_)) |
3144 ty_bare_fn(..) | ty_ptr(_) => true,
3145 ty_tup(ref tys) if tys.is_empty() => true,
3150 /// Returns true if this type is a floating point type and false otherwise.
3151 pub fn type_is_floating_point(ty: Ty) -> bool {
3153 ty_float(_) => true,
3158 /// Type contents is how the type checker reasons about kinds.
3159 /// They track what kinds of things are found within a type. You can
3160 /// think of them as kind of an "anti-kind". They track the kinds of values
3161 /// and thinks that are contained in types. Having a larger contents for
3162 /// a type tends to rule that type *out* from various kinds. For example,
3163 /// a type that contains a reference is not sendable.
3165 /// The reason we compute type contents and not kinds is that it is
3166 /// easier for me (nmatsakis) to think about what is contained within
3167 /// a type than to think about what is *not* contained within a type.
3168 #[derive(Clone, Copy)]
3169 pub struct TypeContents {
3173 macro_rules! def_type_content_sets {
3174 (mod $mname:ident { $($name:ident = $bits:expr),+ }) => {
3175 #[allow(non_snake_case)]
3177 use middle::ty::TypeContents;
3179 #[allow(non_upper_case_globals)]
3180 pub const $name: TypeContents = TypeContents { bits: $bits };
3186 def_type_content_sets! {
3188 None = 0b0000_0000__0000_0000__0000,
3190 // Things that are interior to the value (first nibble):
3191 InteriorUnsized = 0b0000_0000__0000_0000__0001,
3192 InteriorUnsafe = 0b0000_0000__0000_0000__0010,
3193 InteriorParam = 0b0000_0000__0000_0000__0100,
3194 // InteriorAll = 0b00000000__00000000__1111,
3196 // Things that are owned by the value (second and third nibbles):
3197 OwnsOwned = 0b0000_0000__0000_0001__0000,
3198 OwnsDtor = 0b0000_0000__0000_0010__0000,
3199 OwnsManaged /* see [1] below */ = 0b0000_0000__0000_0100__0000,
3200 OwnsAll = 0b0000_0000__1111_1111__0000,
3202 // Things that are reachable by the value in any way (fourth nibble):
3203 ReachesBorrowed = 0b0000_0010__0000_0000__0000,
3204 // ReachesManaged /* see [1] below */ = 0b0000_0100__0000_0000__0000,
3205 ReachesMutable = 0b0000_1000__0000_0000__0000,
3206 ReachesFfiUnsafe = 0b0010_0000__0000_0000__0000,
3207 ReachesAll = 0b0011_1111__0000_0000__0000,
3209 // Things that mean drop glue is necessary
3210 NeedsDrop = 0b0000_0000__0000_0111__0000,
3212 // Things that prevent values from being considered sized
3213 Nonsized = 0b0000_0000__0000_0000__0001,
3215 // Bits to set when a managed value is encountered
3217 // [1] Do not set the bits TC::OwnsManaged or
3218 // TC::ReachesManaged directly, instead reference
3219 // TC::Managed to set them both at once.
3220 Managed = 0b0000_0100__0000_0100__0000,
3223 All = 0b1111_1111__1111_1111__1111
3228 pub fn when(&self, cond: bool) -> TypeContents {
3229 if cond {*self} else {TC::None}
3232 pub fn intersects(&self, tc: TypeContents) -> bool {
3233 (self.bits & tc.bits) != 0
3236 pub fn owns_managed(&self) -> bool {
3237 self.intersects(TC::OwnsManaged)
3240 pub fn owns_owned(&self) -> bool {
3241 self.intersects(TC::OwnsOwned)
3244 pub fn is_sized(&self, _: &ctxt) -> bool {
3245 !self.intersects(TC::Nonsized)
3248 pub fn interior_param(&self) -> bool {
3249 self.intersects(TC::InteriorParam)
3252 pub fn interior_unsafe(&self) -> bool {
3253 self.intersects(TC::InteriorUnsafe)
3256 pub fn interior_unsized(&self) -> bool {
3257 self.intersects(TC::InteriorUnsized)
3260 pub fn needs_drop(&self, _: &ctxt) -> bool {
3261 self.intersects(TC::NeedsDrop)
3264 /// Includes only those bits that still apply when indirected through a `Box` pointer
3265 pub fn owned_pointer(&self) -> TypeContents {
3267 *self & (TC::OwnsAll | TC::ReachesAll))
3270 /// Includes only those bits that still apply when indirected through a reference (`&`)
3271 pub fn reference(&self, bits: TypeContents) -> TypeContents {
3273 *self & TC::ReachesAll)
3276 /// Includes only those bits that still apply when indirected through a managed pointer (`@`)
3277 pub fn managed_pointer(&self) -> TypeContents {
3279 *self & TC::ReachesAll)
3282 /// Includes only those bits that still apply when indirected through an unsafe pointer (`*`)
3283 pub fn unsafe_pointer(&self) -> TypeContents {
3284 *self & TC::ReachesAll
3287 pub fn union<T, F>(v: &[T], mut f: F) -> TypeContents where
3288 F: FnMut(&T) -> TypeContents,
3290 v.iter().fold(TC::None, |tc, ty| tc | f(ty))
3293 pub fn has_dtor(&self) -> bool {
3294 self.intersects(TC::OwnsDtor)
3298 impl ops::BitOr for TypeContents {
3299 type Output = TypeContents;
3301 fn bitor(self, other: TypeContents) -> TypeContents {
3302 TypeContents {bits: self.bits | other.bits}
3306 impl ops::BitAnd for TypeContents {
3307 type Output = TypeContents;
3309 fn bitand(self, other: TypeContents) -> TypeContents {
3310 TypeContents {bits: self.bits & other.bits}
3314 impl ops::Sub for TypeContents {
3315 type Output = TypeContents;
3317 fn sub(self, other: TypeContents) -> TypeContents {
3318 TypeContents {bits: self.bits & !other.bits}
3322 impl fmt::Debug for TypeContents {
3323 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
3324 write!(f, "TypeContents({:b})", self.bits)
3328 pub fn type_interior_is_unsafe<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
3329 type_contents(cx, ty).interior_unsafe()
3332 pub fn type_contents<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> TypeContents {
3333 return memoized(&cx.tc_cache, ty, |ty| {
3334 tc_ty(cx, ty, &mut FnvHashMap())
3337 fn tc_ty<'tcx>(cx: &ctxt<'tcx>,
3339 cache: &mut FnvHashMap<Ty<'tcx>, TypeContents>) -> TypeContents
3341 // Subtle: Note that we are *not* using cx.tc_cache here but rather a
3342 // private cache for this walk. This is needed in the case of cyclic
3345 // struct List { next: Box<Option<List>>, ... }
3347 // When computing the type contents of such a type, we wind up deeply
3348 // recursing as we go. So when we encounter the recursive reference
3349 // to List, we temporarily use TC::None as its contents. Later we'll
3350 // patch up the cache with the correct value, once we've computed it
3351 // (this is basically a co-inductive process, if that helps). So in
3352 // the end we'll compute TC::OwnsOwned, in this case.
3354 // The problem is, as we are doing the computation, we will also
3355 // compute an *intermediate* contents for, e.g., Option<List> of
3356 // TC::None. This is ok during the computation of List itself, but if
3357 // we stored this intermediate value into cx.tc_cache, then later
3358 // requests for the contents of Option<List> would also yield TC::None
3359 // which is incorrect. This value was computed based on the crutch
3360 // value for the type contents of list. The correct value is
3361 // TC::OwnsOwned. This manifested as issue #4821.
3362 match cache.get(&ty) {
3363 Some(tc) => { return *tc; }
3366 match cx.tc_cache.borrow().get(&ty) { // Must check both caches!
3367 Some(tc) => { return *tc; }
3370 cache.insert(ty, TC::None);
3372 let result = match ty.sty {
3373 // uint and int are ffi-unsafe
3374 ty_uint(ast::TyUs(_)) | ty_int(ast::TyIs(_)) => {
3375 TC::ReachesFfiUnsafe
3378 // Scalar and unique types are sendable, and durable
3379 ty_infer(ty::FreshIntTy(_)) |
3380 ty_bool | ty_int(_) | ty_uint(_) | ty_float(_) |
3381 ty_bare_fn(..) | ty::ty_char => {
3386 TC::ReachesFfiUnsafe | match typ.sty {
3387 ty_str => TC::OwnsOwned,
3388 _ => tc_ty(cx, typ, cache).owned_pointer(),
3392 ty_trait(box TyTrait { ref bounds, .. }) => {
3393 object_contents(bounds) | TC::ReachesFfiUnsafe | TC::Nonsized
3397 tc_ty(cx, mt.ty, cache).unsafe_pointer()
3400 ty_rptr(r, ref mt) => {
3401 TC::ReachesFfiUnsafe | match mt.ty.sty {
3402 ty_str => borrowed_contents(*r, ast::MutImmutable),
3403 ty_vec(..) => tc_ty(cx, mt.ty, cache).reference(borrowed_contents(*r,
3405 _ => tc_ty(cx, mt.ty, cache).reference(borrowed_contents(*r, mt.mutbl)),
3409 ty_vec(ty, Some(_)) => {
3410 tc_ty(cx, ty, cache)
3413 ty_vec(ty, None) => {
3414 tc_ty(cx, ty, cache) | TC::Nonsized
3416 ty_str => TC::Nonsized,
3418 ty_struct(did, substs) => {
3419 let flds = struct_fields(cx, did, substs);
3421 TypeContents::union(&flds[],
3422 |f| tc_mt(cx, f.mt, cache));
3424 if !lookup_repr_hints(cx, did).contains(&attr::ReprExtern) {
3425 res = res | TC::ReachesFfiUnsafe;
3428 if ty::has_dtor(cx, did) {
3429 res = res | TC::OwnsDtor;
3431 apply_lang_items(cx, did, res)
3434 ty_unboxed_closure(did, r, substs) => {
3435 // FIXME(#14449): `borrowed_contents` below assumes `&mut`
3437 let param_env = ty::empty_parameter_environment(cx);
3438 let upvars = unboxed_closure_upvars(¶m_env, did, substs).unwrap();
3439 TypeContents::union(upvars.as_slice(),
3440 |f| tc_ty(cx, f.ty, cache))
3441 | borrowed_contents(*r, MutMutable)
3444 ty_tup(ref tys) => {
3445 TypeContents::union(&tys[],
3446 |ty| tc_ty(cx, *ty, cache))
3449 ty_enum(did, substs) => {
3450 let variants = substd_enum_variants(cx, did, substs);
3452 TypeContents::union(&variants[], |variant| {
3453 TypeContents::union(&variant.args[],
3455 tc_ty(cx, *arg_ty, cache)
3459 if ty::has_dtor(cx, did) {
3460 res = res | TC::OwnsDtor;
3463 if variants.len() != 0 {
3464 let repr_hints = lookup_repr_hints(cx, did);
3465 if repr_hints.len() > 1 {
3466 // this is an error later on, but this type isn't safe
3467 res = res | TC::ReachesFfiUnsafe;
3470 match repr_hints.get(0) {
3471 Some(h) => if !h.is_ffi_safe() {
3472 res = res | TC::ReachesFfiUnsafe;
3476 res = res | TC::ReachesFfiUnsafe;
3478 // We allow ReprAny enums if they are eligible for
3479 // the nullable pointer optimization and the
3480 // contained type is an `extern fn`
3482 if variants.len() == 2 {
3483 let mut data_idx = 0;
3485 if variants[0].args.len() == 0 {
3489 if variants[data_idx].args.len() == 1 {
3490 match variants[data_idx].args[0].sty {
3491 ty_bare_fn(..) => { res = res - TC::ReachesFfiUnsafe; }
3501 apply_lang_items(cx, did, res)
3510 let result = tc_ty(cx, ty, cache);
3511 assert!(!result.is_sized(cx));
3512 result.unsafe_pointer() | TC::Nonsized
3517 cx.sess.bug("asked to compute contents of error type");
3521 cache.insert(ty, result);
3525 fn tc_mt<'tcx>(cx: &ctxt<'tcx>,
3527 cache: &mut FnvHashMap<Ty<'tcx>, TypeContents>) -> TypeContents
3529 let mc = TC::ReachesMutable.when(mt.mutbl == MutMutable);
3530 mc | tc_ty(cx, mt.ty, cache)
3533 fn apply_lang_items(cx: &ctxt, did: ast::DefId, tc: TypeContents)
3535 if Some(did) == cx.lang_items.managed_bound() {
3537 } else if Some(did) == cx.lang_items.unsafe_type() {
3538 tc | TC::InteriorUnsafe
3544 /// Type contents due to containing a reference with the region `region` and borrow kind `bk`
3545 fn borrowed_contents(region: ty::Region,
3546 mutbl: ast::Mutability)
3548 let b = match mutbl {
3549 ast::MutMutable => TC::ReachesMutable,
3550 ast::MutImmutable => TC::None,
3552 b | (TC::ReachesBorrowed).when(region != ty::ReStatic)
3555 fn object_contents(bounds: &ExistentialBounds) -> TypeContents {
3556 // These are the type contents of the (opaque) interior. We
3557 // make no assumptions (other than that it cannot have an
3558 // in-scope type parameter within, which makes no sense).
3559 let mut tc = TC::All - TC::InteriorParam;
3560 for bound in bounds.builtin_bounds.iter() {
3561 tc = tc - match bound {
3562 BoundSync | BoundSend | BoundCopy => TC::None,
3563 BoundSized => TC::Nonsized,
3570 fn type_impls_bound<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3571 cache: &RefCell<HashMap<Ty<'tcx>,bool>>,
3573 bound: ty::BuiltinBound,
3577 assert!(!ty::type_needs_infer(ty));
3579 if !type_has_params(ty) && !type_has_self(ty) {
3580 match cache.borrow().get(&ty) {
3583 debug!("type_impls_bound({}, {:?}) = {:?} (cached)",
3584 ty.repr(param_env.tcx),
3592 let infcx = infer::new_infer_ctxt(param_env.tcx);
3594 let is_impld = traits::type_known_to_meet_builtin_bound(&infcx, param_env, ty, bound, span);
3596 debug!("type_impls_bound({}, {:?}) = {:?}",
3597 ty.repr(param_env.tcx),
3601 if !type_has_params(ty) && !type_has_self(ty) {
3602 let old_value = cache.borrow_mut().insert(ty, is_impld);
3603 assert!(old_value.is_none());
3609 pub fn type_moves_by_default<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3614 let tcx = param_env.tcx;
3615 !type_impls_bound(param_env, &tcx.type_impls_copy_cache, ty, ty::BoundCopy, span)
3618 pub fn type_is_sized<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3623 let tcx = param_env.tcx;
3624 type_impls_bound(param_env, &tcx.type_impls_sized_cache, ty, ty::BoundSized, span)
3627 pub fn is_ffi_safe<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
3628 !type_contents(cx, ty).intersects(TC::ReachesFfiUnsafe)
3631 // True if instantiating an instance of `r_ty` requires an instance of `r_ty`.
3632 pub fn is_instantiable<'tcx>(cx: &ctxt<'tcx>, r_ty: Ty<'tcx>) -> bool {
3633 fn type_requires<'tcx>(cx: &ctxt<'tcx>, seen: &mut Vec<DefId>,
3634 r_ty: Ty<'tcx>, ty: Ty<'tcx>) -> bool {
3635 debug!("type_requires({:?}, {:?})?",
3636 ::util::ppaux::ty_to_string(cx, r_ty),
3637 ::util::ppaux::ty_to_string(cx, ty));
3639 let r = r_ty == ty || subtypes_require(cx, seen, r_ty, ty);
3641 debug!("type_requires({:?}, {:?})? {:?}",
3642 ::util::ppaux::ty_to_string(cx, r_ty),
3643 ::util::ppaux::ty_to_string(cx, ty),
3648 fn subtypes_require<'tcx>(cx: &ctxt<'tcx>, seen: &mut Vec<DefId>,
3649 r_ty: Ty<'tcx>, ty: Ty<'tcx>) -> bool {
3650 debug!("subtypes_require({:?}, {:?})?",
3651 ::util::ppaux::ty_to_string(cx, r_ty),
3652 ::util::ppaux::ty_to_string(cx, ty));
3654 let r = match ty.sty {
3655 // fixed length vectors need special treatment compared to
3656 // normal vectors, since they don't necessarily have the
3657 // possibility to have length zero.
3658 ty_vec(_, Some(0)) => false, // don't need no contents
3659 ty_vec(ty, Some(_)) => type_requires(cx, seen, r_ty, ty),
3670 ty_vec(_, None) => {
3673 ty_uniq(typ) | ty_open(typ) => {
3674 type_requires(cx, seen, r_ty, typ)
3676 ty_rptr(_, ref mt) => {
3677 type_requires(cx, seen, r_ty, mt.ty)
3681 false // unsafe ptrs can always be NULL
3688 ty_struct(ref did, _) if seen.contains(did) => {
3692 ty_struct(did, substs) => {
3694 let fields = struct_fields(cx, did, substs);
3695 let r = fields.iter().any(|f| type_requires(cx, seen, r_ty, f.mt.ty));
3696 seen.pop().unwrap();
3702 ty_unboxed_closure(..) => {
3703 // this check is run on type definitions, so we don't expect to see
3704 // inference by-products or unboxed closure types
3705 cx.sess.bug(format!("requires check invoked on inapplicable type: {:?}",
3710 ts.iter().any(|ty| type_requires(cx, seen, r_ty, *ty))
3713 ty_enum(ref did, _) if seen.contains(did) => {
3717 ty_enum(did, substs) => {
3719 let vs = enum_variants(cx, did);
3720 let r = !vs.is_empty() && vs.iter().all(|variant| {
3721 variant.args.iter().any(|aty| {
3722 let sty = aty.subst(cx, substs);
3723 type_requires(cx, seen, r_ty, sty)
3726 seen.pop().unwrap();
3731 debug!("subtypes_require({:?}, {:?})? {:?}",
3732 ::util::ppaux::ty_to_string(cx, r_ty),
3733 ::util::ppaux::ty_to_string(cx, ty),
3739 let mut seen = Vec::new();
3740 !subtypes_require(cx, &mut seen, r_ty, r_ty)
3743 /// Describes whether a type is representable. For types that are not
3744 /// representable, 'SelfRecursive' and 'ContainsRecursive' are used to
3745 /// distinguish between types that are recursive with themselves and types that
3746 /// contain a different recursive type. These cases can therefore be treated
3747 /// differently when reporting errors.
3749 /// The ordering of the cases is significant. They are sorted so that cmp::max
3750 /// will keep the "more erroneous" of two values.
3751 #[derive(Copy, PartialOrd, Ord, Eq, PartialEq, Show)]
3752 pub enum Representability {
3758 /// Check whether a type is representable. This means it cannot contain unboxed
3759 /// structural recursion. This check is needed for structs and enums.
3760 pub fn is_type_representable<'tcx>(cx: &ctxt<'tcx>, sp: Span, ty: Ty<'tcx>)
3761 -> Representability {
3763 // Iterate until something non-representable is found
3764 fn find_nonrepresentable<'tcx, It: Iterator<Item=Ty<'tcx>>>(cx: &ctxt<'tcx>, sp: Span,
3765 seen: &mut Vec<Ty<'tcx>>,
3767 -> Representability {
3768 iter.fold(Representable,
3769 |r, ty| cmp::max(r, is_type_structurally_recursive(cx, sp, seen, ty)))
3772 fn are_inner_types_recursive<'tcx>(cx: &ctxt<'tcx>, sp: Span,
3773 seen: &mut Vec<Ty<'tcx>>, ty: Ty<'tcx>)
3774 -> Representability {
3777 find_nonrepresentable(cx, sp, seen, ts.iter().map(|ty| *ty))
3779 // Fixed-length vectors.
3780 // FIXME(#11924) Behavior undecided for zero-length vectors.
3781 ty_vec(ty, Some(_)) => {
3782 is_type_structurally_recursive(cx, sp, seen, ty)
3784 ty_struct(did, substs) => {
3785 let fields = struct_fields(cx, did, substs);
3786 find_nonrepresentable(cx, sp, seen, fields.iter().map(|f| f.mt.ty))
3788 ty_enum(did, substs) => {
3789 let vs = enum_variants(cx, did);
3790 let iter = vs.iter()
3791 .flat_map(|variant| { variant.args.iter() })
3792 .map(|aty| { aty.subst_spanned(cx, substs, Some(sp)) });
3794 find_nonrepresentable(cx, sp, seen, iter)
3796 ty_unboxed_closure(..) => {
3797 // this check is run on type definitions, so we don't expect to see
3798 // unboxed closure types
3799 cx.sess.bug(format!("requires check invoked on inapplicable type: {:?}",
3806 fn same_struct_or_enum_def_id(ty: Ty, did: DefId) -> bool {
3808 ty_struct(ty_did, _) | ty_enum(ty_did, _) => {
3815 fn same_type<'tcx>(a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
3816 match (&a.sty, &b.sty) {
3817 (&ty_struct(did_a, ref substs_a), &ty_struct(did_b, ref substs_b)) |
3818 (&ty_enum(did_a, ref substs_a), &ty_enum(did_b, ref substs_b)) => {
3823 let types_a = substs_a.types.get_slice(subst::TypeSpace);
3824 let types_b = substs_b.types.get_slice(subst::TypeSpace);
3826 let pairs = types_a.iter().zip(types_b.iter());
3828 pairs.all(|(&a, &b)| same_type(a, b))
3836 // Does the type `ty` directly (without indirection through a pointer)
3837 // contain any types on stack `seen`?
3838 fn is_type_structurally_recursive<'tcx>(cx: &ctxt<'tcx>, sp: Span,
3839 seen: &mut Vec<Ty<'tcx>>,
3840 ty: Ty<'tcx>) -> Representability {
3841 debug!("is_type_structurally_recursive: {:?}",
3842 ::util::ppaux::ty_to_string(cx, ty));
3845 ty_struct(did, _) | ty_enum(did, _) => {
3847 // Iterate through stack of previously seen types.
3848 let mut iter = seen.iter();
3850 // The first item in `seen` is the type we are actually curious about.
3851 // We want to return SelfRecursive if this type contains itself.
3852 // It is important that we DON'T take generic parameters into account
3853 // for this check, so that Bar<T> in this example counts as SelfRecursive:
3856 // struct Bar<T> { x: Bar<Foo> }
3859 Some(&seen_type) => {
3860 if same_struct_or_enum_def_id(seen_type, did) {
3861 debug!("SelfRecursive: {:?} contains {:?}",
3862 ::util::ppaux::ty_to_string(cx, seen_type),
3863 ::util::ppaux::ty_to_string(cx, ty));
3864 return SelfRecursive;
3870 // We also need to know whether the first item contains other types that
3871 // are structurally recursive. If we don't catch this case, we will recurse
3872 // infinitely for some inputs.
3874 // It is important that we DO take generic parameters into account here,
3875 // so that code like this is considered SelfRecursive, not ContainsRecursive:
3877 // struct Foo { Option<Option<Foo>> }
3879 for &seen_type in iter {
3880 if same_type(ty, seen_type) {
3881 debug!("ContainsRecursive: {:?} contains {:?}",
3882 ::util::ppaux::ty_to_string(cx, seen_type),
3883 ::util::ppaux::ty_to_string(cx, ty));
3884 return ContainsRecursive;
3889 // For structs and enums, track all previously seen types by pushing them
3890 // onto the 'seen' stack.
3892 let out = are_inner_types_recursive(cx, sp, seen, ty);
3897 // No need to push in other cases.
3898 are_inner_types_recursive(cx, sp, seen, ty)
3903 debug!("is_type_representable: {:?}",
3904 ::util::ppaux::ty_to_string(cx, ty));
3906 // To avoid a stack overflow when checking an enum variant or struct that
3907 // contains a different, structurally recursive type, maintain a stack
3908 // of seen types and check recursion for each of them (issues #3008, #3779).
3909 let mut seen: Vec<Ty> = Vec::new();
3910 let r = is_type_structurally_recursive(cx, sp, &mut seen, ty);
3911 debug!("is_type_representable: {:?} is {:?}",
3912 ::util::ppaux::ty_to_string(cx, ty), r);
3916 pub fn type_is_trait(ty: Ty) -> bool {
3917 type_trait_info(ty).is_some()
3920 pub fn type_trait_info<'tcx>(ty: Ty<'tcx>) -> Option<&'tcx TyTrait<'tcx>> {
3922 ty_uniq(ty) | ty_rptr(_, mt { ty, ..}) | ty_ptr(mt { ty, ..}) => match ty.sty {
3923 ty_trait(ref t) => Some(&**t),
3926 ty_trait(ref t) => Some(&**t),
3931 pub fn type_is_integral(ty: Ty) -> bool {
3933 ty_infer(IntVar(_)) | ty_int(_) | ty_uint(_) => true,
3938 pub fn type_is_fresh(ty: Ty) -> bool {
3940 ty_infer(FreshTy(_)) => true,
3941 ty_infer(FreshIntTy(_)) => true,
3946 pub fn type_is_uint(ty: Ty) -> bool {
3948 ty_infer(IntVar(_)) | ty_uint(ast::TyUs(_)) => true,
3953 pub fn type_is_char(ty: Ty) -> bool {
3960 pub fn type_is_bare_fn(ty: Ty) -> bool {
3962 ty_bare_fn(..) => true,
3967 pub fn type_is_bare_fn_item(ty: Ty) -> bool {
3969 ty_bare_fn(Some(_), _) => true,
3974 pub fn type_is_fp(ty: Ty) -> bool {
3976 ty_infer(FloatVar(_)) | ty_float(_) => true,
3981 pub fn type_is_numeric(ty: Ty) -> bool {
3982 return type_is_integral(ty) || type_is_fp(ty);
3985 pub fn type_is_signed(ty: Ty) -> bool {
3992 pub fn type_is_machine(ty: Ty) -> bool {
3994 ty_int(ast::TyIs(_)) | ty_uint(ast::TyUs(_)) => false,
3995 ty_int(..) | ty_uint(..) | ty_float(..) => true,
4000 // Whether a type is enum like, that is an enum type with only nullary
4002 pub fn type_is_c_like_enum(cx: &ctxt, ty: Ty) -> bool {
4004 ty_enum(did, _) => {
4005 let variants = enum_variants(cx, did);
4006 if variants.len() == 0 {
4009 variants.iter().all(|v| v.args.len() == 0)
4016 // Returns the type and mutability of *ty.
4018 // The parameter `explicit` indicates if this is an *explicit* dereference.
4019 // Some types---notably unsafe ptrs---can only be dereferenced explicitly.
4020 pub fn deref<'tcx>(ty: Ty<'tcx>, explicit: bool) -> Option<mt<'tcx>> {
4025 mutbl: ast::MutImmutable,
4028 ty_rptr(_, mt) => Some(mt),
4029 ty_ptr(mt) if explicit => Some(mt),
4034 pub fn close_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
4036 ty_open(ty) => mk_rptr(cx, cx.mk_region(ReStatic), mt {ty: ty, mutbl:ast::MutImmutable}),
4037 _ => cx.sess.bug(&format!("Trying to close a non-open type {}",
4038 ty_to_string(cx, ty))[])
4042 pub fn type_content<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
4045 ty_rptr(_, mt) |ty_ptr(mt) => mt.ty,
4050 // Extract the unsized type in an open type (or just return ty if it is not open).
4051 pub fn unopen_type<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
4058 // Returns the type of ty[i]
4059 pub fn index<'tcx>(ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
4061 ty_vec(ty, _) => Some(ty),
4066 // Returns the type of elements contained within an 'array-like' type.
4067 // This is exactly the same as the above, except it supports strings,
4068 // which can't actually be indexed.
4069 pub fn array_element_ty<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
4071 ty_vec(ty, _) => Some(ty),
4072 ty_str => Some(tcx.types.u8),
4077 /// Returns the type of element at index `i` in tuple or tuple-like type `t`.
4078 /// For an enum `t`, `variant` is None only if `t` is a univariant enum.
4079 pub fn positional_element_ty<'tcx>(cx: &ctxt<'tcx>,
4082 variant: Option<ast::DefId>) -> Option<Ty<'tcx>> {
4084 match (&ty.sty, variant) {
4085 (&ty_tup(ref v), None) => v.get(i).map(|&t| t),
4088 (&ty_struct(def_id, substs), None) => lookup_struct_fields(cx, def_id)
4090 .map(|&t|lookup_item_type(cx, t.id).ty.subst(cx, substs)),
4092 (&ty_enum(def_id, substs), Some(variant_def_id)) => {
4093 let variant_info = enum_variant_with_id(cx, def_id, variant_def_id);
4094 variant_info.args.get(i).map(|t|t.subst(cx, substs))
4097 (&ty_enum(def_id, substs), None) => {
4098 assert!(enum_is_univariant(cx, def_id));
4099 let enum_variants = enum_variants(cx, def_id);
4100 let variant_info = &(*enum_variants)[0];
4101 variant_info.args.get(i).map(|t|t.subst(cx, substs))
4108 /// Returns the type of element at field `n` in struct or struct-like type `t`.
4109 /// For an enum `t`, `variant` must be some def id.
4110 pub fn named_element_ty<'tcx>(cx: &ctxt<'tcx>,
4113 variant: Option<ast::DefId>) -> Option<Ty<'tcx>> {
4115 match (&ty.sty, variant) {
4116 (&ty_struct(def_id, substs), None) => {
4117 let r = lookup_struct_fields(cx, def_id);
4118 r.iter().find(|f| f.name == n)
4119 .map(|&f| lookup_field_type(cx, def_id, f.id, substs))
4121 (&ty_enum(def_id, substs), Some(variant_def_id)) => {
4122 let variant_info = enum_variant_with_id(cx, def_id, variant_def_id);
4123 variant_info.arg_names.as_ref()
4124 .expect("must have struct enum variant if accessing a named fields")
4125 .iter().zip(variant_info.args.iter())
4126 .find(|&(ident, _)| ident.name == n)
4127 .map(|(_ident, arg_t)| arg_t.subst(cx, substs))
4133 pub fn node_id_to_trait_ref<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId)
4134 -> Rc<ty::TraitRef<'tcx>> {
4135 match cx.trait_refs.borrow().get(&id) {
4136 Some(ty) => ty.clone(),
4137 None => cx.sess.bug(
4138 &format!("node_id_to_trait_ref: no trait ref for node `{}`",
4139 cx.map.node_to_string(id))[])
4143 pub fn node_id_to_type<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Ty<'tcx> {
4144 match node_id_to_type_opt(cx, id) {
4146 None => cx.sess.bug(
4147 &format!("node_id_to_type: no type for node `{}`",
4148 cx.map.node_to_string(id))[])
4152 pub fn node_id_to_type_opt<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Option<Ty<'tcx>> {
4153 match cx.node_types.borrow().get(&id) {
4154 Some(&ty) => Some(ty),
4159 pub fn node_id_item_substs<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> ItemSubsts<'tcx> {
4160 match cx.item_substs.borrow().get(&id) {
4161 None => ItemSubsts::empty(),
4162 Some(ts) => ts.clone(),
4166 pub fn fn_is_variadic(fty: Ty) -> bool {
4168 ty_bare_fn(_, ref f) => f.sig.0.variadic,
4170 panic!("fn_is_variadic() called on non-fn type: {:?}", s)
4175 pub fn ty_fn_sig<'tcx>(fty: Ty<'tcx>) -> &'tcx PolyFnSig<'tcx> {
4177 ty_bare_fn(_, ref f) => &f.sig,
4179 panic!("ty_fn_sig() called on non-fn type: {:?}", s)
4184 /// Returns the ABI of the given function.
4185 pub fn ty_fn_abi(fty: Ty) -> abi::Abi {
4187 ty_bare_fn(_, ref f) => f.abi,
4188 _ => panic!("ty_fn_abi() called on non-fn type"),
4192 // Type accessors for substructures of types
4193 pub fn ty_fn_args<'tcx>(fty: Ty<'tcx>) -> ty::Binder<Vec<Ty<'tcx>>> {
4194 ty_fn_sig(fty).inputs()
4197 pub fn ty_closure_store(fty: Ty) -> TraitStore {
4199 ty_unboxed_closure(..) => {
4200 // Close enough for the purposes of all the callers of this
4201 // function (which is soon to be deprecated anyhow).
4205 panic!("ty_closure_store() called on non-closure type: {:?}", s)
4210 pub fn ty_fn_ret<'tcx>(fty: Ty<'tcx>) -> Binder<FnOutput<'tcx>> {
4212 ty_bare_fn(_, ref f) => f.sig.output(),
4214 panic!("ty_fn_ret() called on non-fn type: {:?}", s)
4219 pub fn is_fn_ty(fty: Ty) -> bool {
4221 ty_bare_fn(..) => true,
4226 pub fn ty_region(tcx: &ctxt,
4230 ty_rptr(r, _) => *r,
4234 &format!("ty_region() invoked on an inappropriate ty: {:?}",
4240 pub fn free_region_from_def(free_id: ast::NodeId, def: &RegionParameterDef)
4243 ty::ReFree(ty::FreeRegion { scope: region::CodeExtent::from_node_id(free_id),
4244 bound_region: ty::BrNamed(def.def_id,
4248 // Returns the type of a pattern as a monotype. Like @expr_ty, this function
4249 // doesn't provide type parameter substitutions.
4250 pub fn pat_ty<'tcx>(cx: &ctxt<'tcx>, pat: &ast::Pat) -> Ty<'tcx> {
4251 return node_id_to_type(cx, pat.id);
4255 // Returns the type of an expression as a monotype.
4257 // NB (1): This is the PRE-ADJUSTMENT TYPE for the expression. That is, in
4258 // some cases, we insert `AutoAdjustment` annotations such as auto-deref or
4259 // auto-ref. The type returned by this function does not consider such
4260 // adjustments. See `expr_ty_adjusted()` instead.
4262 // NB (2): This type doesn't provide type parameter substitutions; e.g. if you
4263 // ask for the type of "id" in "id(3)", it will return "fn(&int) -> int"
4264 // instead of "fn(ty) -> T with T = int".
4265 pub fn expr_ty<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Ty<'tcx> {
4266 return node_id_to_type(cx, expr.id);
4269 pub fn expr_ty_opt<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Option<Ty<'tcx>> {
4270 return node_id_to_type_opt(cx, expr.id);
4273 /// Returns the type of `expr`, considering any `AutoAdjustment`
4274 /// entry recorded for that expression.
4276 /// It would almost certainly be better to store the adjusted ty in with
4277 /// the `AutoAdjustment`, but I opted not to do this because it would
4278 /// require serializing and deserializing the type and, although that's not
4279 /// hard to do, I just hate that code so much I didn't want to touch it
4280 /// unless it was to fix it properly, which seemed a distraction from the
4281 /// task at hand! -nmatsakis
4282 pub fn expr_ty_adjusted<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Ty<'tcx> {
4283 adjust_ty(cx, expr.span, expr.id, expr_ty(cx, expr),
4284 cx.adjustments.borrow().get(&expr.id),
4285 |method_call| cx.method_map.borrow().get(&method_call).map(|method| method.ty))
4288 pub fn expr_span(cx: &ctxt, id: NodeId) -> Span {
4289 match cx.map.find(id) {
4290 Some(ast_map::NodeExpr(e)) => {
4294 cx.sess.bug(&format!("Node id {} is not an expr: {:?}",
4299 cx.sess.bug(&format!("Node id {} is not present \
4300 in the node map", id)[]);
4305 pub fn local_var_name_str(cx: &ctxt, id: NodeId) -> InternedString {
4306 match cx.map.find(id) {
4307 Some(ast_map::NodeLocal(pat)) => {
4309 ast::PatIdent(_, ref path1, _) => {
4310 token::get_ident(path1.node)
4314 &format!("Variable id {} maps to {:?}, not local",
4321 cx.sess.bug(&format!("Variable id {} maps to {:?}, not local",
4328 /// See `expr_ty_adjusted`
4329 pub fn adjust_ty<'tcx, F>(cx: &ctxt<'tcx>,
4331 expr_id: ast::NodeId,
4332 unadjusted_ty: Ty<'tcx>,
4333 adjustment: Option<&AutoAdjustment<'tcx>>,
4336 F: FnMut(MethodCall) -> Option<Ty<'tcx>>,
4338 if let ty_err = unadjusted_ty.sty {
4339 return unadjusted_ty;
4342 return match adjustment {
4343 Some(adjustment) => {
4345 AdjustReifyFnPointer(_) => {
4346 match unadjusted_ty.sty {
4347 ty::ty_bare_fn(Some(_), b) => {
4348 ty::mk_bare_fn(cx, None, b)
4352 &format!("AdjustReifyFnPointer adjustment on non-fn-item: \
4359 AdjustDerefRef(ref adj) => {
4360 let mut adjusted_ty = unadjusted_ty;
4362 if !ty::type_is_error(adjusted_ty) {
4363 for i in range(0, adj.autoderefs) {
4364 let method_call = MethodCall::autoderef(expr_id, i);
4365 match method_type(method_call) {
4366 Some(method_ty) => {
4367 // overloaded deref operators have all late-bound
4368 // regions fully instantiated and coverge
4370 ty::assert_no_late_bound_regions(cx,
4371 &ty_fn_ret(method_ty));
4372 adjusted_ty = fn_ret.unwrap();
4376 match deref(adjusted_ty, true) {
4377 Some(mt) => { adjusted_ty = mt.ty; }
4381 &format!("the {}th autoderef failed: \
4384 ty_to_string(cx, adjusted_ty))
4391 adjust_ty_for_autoref(cx, span, adjusted_ty, adj.autoref.as_ref())
4395 None => unadjusted_ty
4399 pub fn adjust_ty_for_autoref<'tcx>(cx: &ctxt<'tcx>,
4402 autoref: Option<&AutoRef<'tcx>>)
4408 Some(&AutoPtr(r, m, ref a)) => {
4409 let adjusted_ty = match a {
4410 &Some(box ref a) => adjust_ty_for_autoref(cx, span, ty, Some(a)),
4413 mk_rptr(cx, cx.mk_region(r), mt {
4419 Some(&AutoUnsafe(m, ref a)) => {
4420 let adjusted_ty = match a {
4421 &Some(box ref a) => adjust_ty_for_autoref(cx, span, ty, Some(a)),
4424 mk_ptr(cx, mt {ty: adjusted_ty, mutbl: m})
4427 Some(&AutoUnsize(ref k)) => unsize_ty(cx, ty, k, span),
4429 Some(&AutoUnsizeUniq(ref k)) => ty::mk_uniq(cx, unsize_ty(cx, ty, k, span)),
4433 // Take a sized type and a sizing adjustment and produce an unsized version of
4435 pub fn unsize_ty<'tcx>(cx: &ctxt<'tcx>,
4437 kind: &UnsizeKind<'tcx>,
4441 &UnsizeLength(len) => match ty.sty {
4442 ty_vec(ty, Some(n)) => {
4444 mk_vec(cx, ty, None)
4446 _ => cx.sess.span_bug(span,
4447 &format!("UnsizeLength with bad sty: {:?}",
4448 ty_to_string(cx, ty))[])
4450 &UnsizeStruct(box ref k, tp_index) => match ty.sty {
4451 ty_struct(did, substs) => {
4452 let ty_substs = substs.types.get_slice(subst::TypeSpace);
4453 let new_ty = unsize_ty(cx, ty_substs[tp_index], k, span);
4454 let mut unsized_substs = substs.clone();
4455 unsized_substs.types.get_mut_slice(subst::TypeSpace)[tp_index] = new_ty;
4456 mk_struct(cx, did, cx.mk_substs(unsized_substs))
4458 _ => cx.sess.span_bug(span,
4459 &format!("UnsizeStruct with bad sty: {:?}",
4460 ty_to_string(cx, ty))[])
4462 &UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
4463 mk_trait(cx, principal.clone(), bounds.clone())
4468 pub fn resolve_expr(tcx: &ctxt, expr: &ast::Expr) -> def::Def {
4469 match tcx.def_map.borrow().get(&expr.id) {
4472 tcx.sess.span_bug(expr.span, &format!(
4473 "no def-map entry for expr {}", expr.id)[]);
4478 pub fn expr_is_lval(tcx: &ctxt, e: &ast::Expr) -> bool {
4479 match expr_kind(tcx, e) {
4481 RvalueDpsExpr | RvalueDatumExpr | RvalueStmtExpr => false
4485 /// We categorize expressions into three kinds. The distinction between
4486 /// lvalue/rvalue is fundamental to the language. The distinction between the
4487 /// two kinds of rvalues is an artifact of trans which reflects how we will
4488 /// generate code for that kind of expression. See trans/expr.rs for more
4498 pub fn expr_kind(tcx: &ctxt, expr: &ast::Expr) -> ExprKind {
4499 if tcx.method_map.borrow().contains_key(&MethodCall::expr(expr.id)) {
4500 // Overloaded operations are generally calls, and hence they are
4501 // generated via DPS, but there are a few exceptions:
4502 return match expr.node {
4503 // `a += b` has a unit result.
4504 ast::ExprAssignOp(..) => RvalueStmtExpr,
4506 // the deref method invoked for `*a` always yields an `&T`
4507 ast::ExprUnary(ast::UnDeref, _) => LvalueExpr,
4509 // the index method invoked for `a[i]` always yields an `&T`
4510 ast::ExprIndex(..) => LvalueExpr,
4512 // `for` loops are statements
4513 ast::ExprForLoop(..) => RvalueStmtExpr,
4515 // in the general case, result could be any type, use DPS
4521 ast::ExprPath(_) | ast::ExprQPath(_) => {
4522 match resolve_expr(tcx, expr) {
4523 def::DefVariant(tid, vid, _) => {
4524 let variant_info = enum_variant_with_id(tcx, tid, vid);
4525 if variant_info.args.len() > 0u {
4534 def::DefStruct(_) => {
4535 match tcx.node_types.borrow().get(&expr.id) {
4536 Some(ty) => match ty.sty {
4537 ty_bare_fn(..) => RvalueDatumExpr,
4540 // See ExprCast below for why types might be missing.
4541 None => RvalueDatumExpr
4545 // Special case: A unit like struct's constructor must be called without () at the
4546 // end (like `UnitStruct`) which means this is an ExprPath to a DefFn. But in case
4547 // of unit structs this is should not be interpreted as function pointer but as
4548 // call to the constructor.
4549 def::DefFn(_, true) => RvalueDpsExpr,
4551 // Fn pointers are just scalar values.
4552 def::DefFn(..) | def::DefStaticMethod(..) | def::DefMethod(..) => RvalueDatumExpr,
4554 // Note: there is actually a good case to be made that
4555 // DefArg's, particularly those of immediate type, ought to
4556 // considered rvalues.
4557 def::DefStatic(..) |
4559 def::DefLocal(..) => LvalueExpr,
4561 def::DefConst(..) => RvalueDatumExpr,
4566 &format!("uncategorized def for expr {}: {:?}",
4573 ast::ExprUnary(ast::UnDeref, _) |
4574 ast::ExprField(..) |
4575 ast::ExprTupField(..) |
4576 ast::ExprIndex(..) => {
4581 ast::ExprMethodCall(..) |
4582 ast::ExprStruct(..) |
4583 ast::ExprRange(..) |
4586 ast::ExprMatch(..) |
4587 ast::ExprClosure(..) |
4588 ast::ExprBlock(..) |
4589 ast::ExprRepeat(..) |
4590 ast::ExprVec(..) => {
4594 ast::ExprIfLet(..) => {
4595 tcx.sess.span_bug(expr.span, "non-desugared ExprIfLet");
4597 ast::ExprWhileLet(..) => {
4598 tcx.sess.span_bug(expr.span, "non-desugared ExprWhileLet");
4601 ast::ExprLit(ref lit) if lit_is_str(&**lit) => {
4605 ast::ExprCast(..) => {
4606 match tcx.node_types.borrow().get(&expr.id) {
4608 if type_is_trait(ty) {
4615 // Technically, it should not happen that the expr is not
4616 // present within the table. However, it DOES happen
4617 // during type check, because the final types from the
4618 // expressions are not yet recorded in the tcx. At that
4619 // time, though, we are only interested in knowing lvalue
4620 // vs rvalue. It would be better to base this decision on
4621 // the AST type in cast node---but (at the time of this
4622 // writing) it's not easy to distinguish casts to traits
4623 // from other casts based on the AST. This should be
4624 // easier in the future, when casts to traits
4625 // would like @Foo, Box<Foo>, or &Foo.
4631 ast::ExprBreak(..) |
4632 ast::ExprAgain(..) |
4634 ast::ExprWhile(..) |
4636 ast::ExprAssign(..) |
4637 ast::ExprInlineAsm(..) |
4638 ast::ExprAssignOp(..) |
4639 ast::ExprForLoop(..) => {
4643 ast::ExprLit(_) | // Note: LitStr is carved out above
4644 ast::ExprUnary(..) |
4645 ast::ExprBox(None, _) |
4646 ast::ExprAddrOf(..) |
4647 ast::ExprBinary(..) => {
4651 ast::ExprBox(Some(ref place), _) => {
4652 // Special case `Box<T>` for now:
4653 let definition = match tcx.def_map.borrow().get(&place.id) {
4655 None => panic!("no def for place"),
4657 let def_id = definition.def_id();
4658 if tcx.lang_items.exchange_heap() == Some(def_id) {
4665 ast::ExprParen(ref e) => expr_kind(tcx, &**e),
4667 ast::ExprMac(..) => {
4670 "macro expression remains after expansion");
4675 pub fn stmt_node_id(s: &ast::Stmt) -> ast::NodeId {
4677 ast::StmtDecl(_, id) | StmtExpr(_, id) | StmtSemi(_, id) => {
4680 ast::StmtMac(..) => panic!("unexpanded macro in trans")
4684 pub fn field_idx_strict(tcx: &ctxt, name: ast::Name, fields: &[field])
4687 for f in fields.iter() { if f.name == name { return i; } i += 1u; }
4688 tcx.sess.bug(&format!(
4689 "no field named `{}` found in the list of fields `{:?}`",
4690 token::get_name(name),
4692 .map(|f| token::get_name(f.name).get().to_string())
4693 .collect::<Vec<String>>())[]);
4696 pub fn impl_or_trait_item_idx(id: ast::Name, trait_items: &[ImplOrTraitItem])
4698 trait_items.iter().position(|m| m.name() == id)
4701 pub fn ty_sort_string<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> String {
4703 ty_bool | ty_char | ty_int(_) |
4704 ty_uint(_) | ty_float(_) | ty_str => {
4705 ::util::ppaux::ty_to_string(cx, ty)
4707 ty_tup(ref tys) if tys.is_empty() => ::util::ppaux::ty_to_string(cx, ty),
4709 ty_enum(id, _) => format!("enum `{}`", item_path_str(cx, id)),
4710 ty_uniq(_) => "box".to_string(),
4711 ty_vec(_, Some(n)) => format!("array of {} elements", n),
4712 ty_vec(_, None) => "slice".to_string(),
4713 ty_ptr(_) => "*-ptr".to_string(),
4714 ty_rptr(_, _) => "&-ptr".to_string(),
4715 ty_bare_fn(Some(_), _) => format!("fn item"),
4716 ty_bare_fn(None, _) => "fn pointer".to_string(),
4717 ty_trait(ref inner) => {
4718 format!("trait {}", item_path_str(cx, inner.principal_def_id()))
4720 ty_struct(id, _) => {
4721 format!("struct `{}`", item_path_str(cx, id))
4723 ty_unboxed_closure(..) => "closure".to_string(),
4724 ty_tup(_) => "tuple".to_string(),
4725 ty_infer(TyVar(_)) => "inferred type".to_string(),
4726 ty_infer(IntVar(_)) => "integral variable".to_string(),
4727 ty_infer(FloatVar(_)) => "floating-point variable".to_string(),
4728 ty_infer(FreshTy(_)) => "skolemized type".to_string(),
4729 ty_infer(FreshIntTy(_)) => "skolemized integral type".to_string(),
4730 ty_projection(_) => "associated type".to_string(),
4731 ty_param(ref p) => {
4732 if p.space == subst::SelfSpace {
4735 "type parameter".to_string()
4738 ty_err => "type error".to_string(),
4739 ty_open(_) => "opened DST".to_string(),
4743 impl<'tcx> Repr<'tcx> for ty::type_err<'tcx> {
4744 fn repr(&self, tcx: &ty::ctxt<'tcx>) -> String {
4745 ty::type_err_to_str(tcx, self)
4749 /// Explains the source of a type err in a short, human readable way. This is meant to be placed
4750 /// in parentheses after some larger message. You should also invoke `note_and_explain_type_err()`
4751 /// afterwards to present additional details, particularly when it comes to lifetime-related
4753 pub fn type_err_to_str<'tcx>(cx: &ctxt<'tcx>, err: &type_err<'tcx>) -> String {
4754 fn tstore_to_closure(s: &TraitStore) -> String {
4756 &UniqTraitStore => "proc".to_string(),
4757 &RegionTraitStore(..) => "closure".to_string()
4762 terr_cyclic_ty => "cyclic type of infinite size".to_string(),
4763 terr_mismatch => "types differ".to_string(),
4764 terr_unsafety_mismatch(values) => {
4765 format!("expected {} fn, found {} fn",
4769 terr_abi_mismatch(values) => {
4770 format!("expected {} fn, found {} fn",
4774 terr_onceness_mismatch(values) => {
4775 format!("expected {} fn, found {} fn",
4779 terr_sigil_mismatch(values) => {
4780 format!("expected {}, found {}",
4781 tstore_to_closure(&values.expected),
4782 tstore_to_closure(&values.found))
4784 terr_mutability => "values differ in mutability".to_string(),
4785 terr_box_mutability => {
4786 "boxed values differ in mutability".to_string()
4788 terr_vec_mutability => "vectors differ in mutability".to_string(),
4789 terr_ptr_mutability => "pointers differ in mutability".to_string(),
4790 terr_ref_mutability => "references differ in mutability".to_string(),
4791 terr_ty_param_size(values) => {
4792 format!("expected a type with {} type params, \
4793 found one with {} type params",
4797 terr_fixed_array_size(values) => {
4798 format!("expected an array with a fixed size of {} elements, \
4799 found one with {} elements",
4803 terr_tuple_size(values) => {
4804 format!("expected a tuple with {} elements, \
4805 found one with {} elements",
4810 "incorrect number of function parameters".to_string()
4812 terr_regions_does_not_outlive(..) => {
4813 "lifetime mismatch".to_string()
4815 terr_regions_not_same(..) => {
4816 "lifetimes are not the same".to_string()
4818 terr_regions_no_overlap(..) => {
4819 "lifetimes do not intersect".to_string()
4821 terr_regions_insufficiently_polymorphic(br, _) => {
4822 format!("expected bound lifetime parameter {}, \
4823 found concrete lifetime",
4824 bound_region_ptr_to_string(cx, br))
4826 terr_regions_overly_polymorphic(br, _) => {
4827 format!("expected concrete lifetime, \
4828 found bound lifetime parameter {}",
4829 bound_region_ptr_to_string(cx, br))
4831 terr_trait_stores_differ(_, ref values) => {
4832 format!("trait storage differs: expected `{}`, found `{}`",
4833 trait_store_to_string(cx, (*values).expected),
4834 trait_store_to_string(cx, (*values).found))
4836 terr_sorts(values) => {
4837 // A naive approach to making sure that we're not reporting silly errors such as:
4838 // (expected closure, found closure).
4839 let expected_str = ty_sort_string(cx, values.expected);
4840 let found_str = ty_sort_string(cx, values.found);
4841 if expected_str == found_str {
4842 format!("expected {}, found a different {}", expected_str, found_str)
4844 format!("expected {}, found {}", expected_str, found_str)
4847 terr_traits(values) => {
4848 format!("expected trait `{}`, found trait `{}`",
4849 item_path_str(cx, values.expected),
4850 item_path_str(cx, values.found))
4852 terr_builtin_bounds(values) => {
4853 if values.expected.is_empty() {
4854 format!("expected no bounds, found `{}`",
4855 values.found.user_string(cx))
4856 } else if values.found.is_empty() {
4857 format!("expected bounds `{}`, found no bounds",
4858 values.expected.user_string(cx))
4860 format!("expected bounds `{}`, found bounds `{}`",
4861 values.expected.user_string(cx),
4862 values.found.user_string(cx))
4865 terr_integer_as_char => {
4866 "expected an integral type, found `char`".to_string()
4868 terr_int_mismatch(ref values) => {
4869 format!("expected `{:?}`, found `{:?}`",
4873 terr_float_mismatch(ref values) => {
4874 format!("expected `{:?}`, found `{:?}`",
4878 terr_variadic_mismatch(ref values) => {
4879 format!("expected {} fn, found {} function",
4880 if values.expected { "variadic" } else { "non-variadic" },
4881 if values.found { "variadic" } else { "non-variadic" })
4883 terr_convergence_mismatch(ref values) => {
4884 format!("expected {} fn, found {} function",
4885 if values.expected { "converging" } else { "diverging" },
4886 if values.found { "converging" } else { "diverging" })
4888 terr_projection_name_mismatched(ref values) => {
4889 format!("expected {}, found {}",
4890 token::get_name(values.expected),
4891 token::get_name(values.found))
4893 terr_projection_bounds_length(ref values) => {
4894 format!("expected {} associated type bindings, found {}",
4901 pub fn note_and_explain_type_err(cx: &ctxt, err: &type_err) {
4903 terr_regions_does_not_outlive(subregion, superregion) => {
4904 note_and_explain_region(cx, "", subregion, "...");
4905 note_and_explain_region(cx, "...does not necessarily outlive ",
4908 terr_regions_not_same(region1, region2) => {
4909 note_and_explain_region(cx, "", region1, "...");
4910 note_and_explain_region(cx, "...is not the same lifetime as ",
4913 terr_regions_no_overlap(region1, region2) => {
4914 note_and_explain_region(cx, "", region1, "...");
4915 note_and_explain_region(cx, "...does not overlap ",
4918 terr_regions_insufficiently_polymorphic(_, conc_region) => {
4919 note_and_explain_region(cx,
4920 "concrete lifetime that was found is ",
4923 terr_regions_overly_polymorphic(_, ty::ReInfer(ty::ReVar(_))) => {
4924 // don't bother to print out the message below for
4925 // inference variables, it's not very illuminating.
4927 terr_regions_overly_polymorphic(_, conc_region) => {
4928 note_and_explain_region(cx,
4929 "expected concrete lifetime is ",
4936 pub fn provided_source(cx: &ctxt, id: ast::DefId) -> Option<ast::DefId> {
4937 cx.provided_method_sources.borrow().get(&id).map(|x| *x)
4940 pub fn provided_trait_methods<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
4941 -> Vec<Rc<Method<'tcx>>> {
4943 match cx.map.find(id.node) {
4944 Some(ast_map::NodeItem(item)) => {
4946 ItemTrait(_, _, _, ref ms) => {
4948 ast_util::split_trait_methods(&ms[]);
4951 match impl_or_trait_item(
4953 ast_util::local_def(m.id)) {
4954 MethodTraitItem(m) => m,
4955 TypeTraitItem(_) => {
4956 cx.sess.bug("provided_trait_methods(): \
4957 split_trait_methods() put \
4958 associated types in the \
4959 provided method bucket?!")
4965 cx.sess.bug(&format!("provided_trait_methods: `{:?}` is \
4972 cx.sess.bug(&format!("provided_trait_methods: `{:?}` is not a \
4978 csearch::get_provided_trait_methods(cx, id)
4982 /// Helper for looking things up in the various maps that are populated during
4983 /// typeck::collect (e.g., `cx.impl_or_trait_items`, `cx.tcache`, etc). All of
4984 /// these share the pattern that if the id is local, it should have been loaded
4985 /// into the map by the `typeck::collect` phase. If the def-id is external,
4986 /// then we have to go consult the crate loading code (and cache the result for
4988 fn lookup_locally_or_in_crate_store<V, F>(descr: &str,
4990 map: &mut DefIdMap<V>,
4991 load_external: F) -> V where
4995 match map.get(&def_id).cloned() {
4996 Some(v) => { return v; }
5000 if def_id.krate == ast::LOCAL_CRATE {
5001 panic!("No def'n found for {:?} in tcx.{}", def_id, descr);
5003 let v = load_external();
5004 map.insert(def_id, v.clone());
5008 pub fn trait_item<'tcx>(cx: &ctxt<'tcx>, trait_did: ast::DefId, idx: uint)
5009 -> ImplOrTraitItem<'tcx> {
5010 let method_def_id = (*ty::trait_item_def_ids(cx, trait_did))[idx].def_id();
5011 impl_or_trait_item(cx, method_def_id)
5014 pub fn trait_items<'tcx>(cx: &ctxt<'tcx>, trait_did: ast::DefId)
5015 -> Rc<Vec<ImplOrTraitItem<'tcx>>> {
5016 let mut trait_items = cx.trait_items_cache.borrow_mut();
5017 match trait_items.get(&trait_did).cloned() {
5018 Some(trait_items) => trait_items,
5020 let def_ids = ty::trait_item_def_ids(cx, trait_did);
5021 let items: Rc<Vec<ImplOrTraitItem>> =
5022 Rc::new(def_ids.iter()
5023 .map(|d| impl_or_trait_item(cx, d.def_id()))
5025 trait_items.insert(trait_did, items.clone());
5031 pub fn trait_impl_polarity<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5032 -> Option<ast::ImplPolarity> {
5033 if id.krate == ast::LOCAL_CRATE {
5034 match cx.map.find(id.node) {
5035 Some(ast_map::NodeItem(item)) => {
5037 ast::ItemImpl(_, polarity, _, _, _, _) => Some(polarity),
5044 csearch::get_impl_polarity(cx, id)
5048 pub fn impl_or_trait_item<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5049 -> ImplOrTraitItem<'tcx> {
5050 lookup_locally_or_in_crate_store("impl_or_trait_items",
5052 &mut *cx.impl_or_trait_items
5055 csearch::get_impl_or_trait_item(cx, id)
5059 /// Returns true if the given ID refers to an associated type and false if it
5060 /// refers to anything else.
5061 pub fn is_associated_type(cx: &ctxt, id: ast::DefId) -> bool {
5062 memoized(&cx.associated_types, id, |id: ast::DefId| {
5063 if id.krate == ast::LOCAL_CRATE {
5064 match cx.impl_or_trait_items.borrow().get(&id) {
5067 TypeTraitItem(_) => true,
5068 MethodTraitItem(_) => false,
5074 csearch::is_associated_type(&cx.sess.cstore, id)
5079 /// Returns the parameter index that the given associated type corresponds to.
5080 pub fn associated_type_parameter_index(cx: &ctxt,
5081 trait_def: &TraitDef,
5082 associated_type_id: ast::DefId)
5084 for type_parameter_def in trait_def.generics.types.iter() {
5085 if type_parameter_def.def_id == associated_type_id {
5086 return type_parameter_def.index as uint
5089 cx.sess.bug("couldn't find associated type parameter index")
5092 #[derive(Copy, PartialEq, Eq)]
5093 pub struct AssociatedTypeInfo {
5094 pub def_id: ast::DefId,
5096 pub name: ast::Name,
5099 impl PartialOrd for AssociatedTypeInfo {
5100 fn partial_cmp(&self, other: &AssociatedTypeInfo) -> Option<Ordering> {
5101 Some(self.index.cmp(&other.index))
5105 impl Ord for AssociatedTypeInfo {
5106 fn cmp(&self, other: &AssociatedTypeInfo) -> Ordering {
5107 self.index.cmp(&other.index)
5111 pub fn trait_item_def_ids(cx: &ctxt, id: ast::DefId)
5112 -> Rc<Vec<ImplOrTraitItemId>> {
5113 lookup_locally_or_in_crate_store("trait_item_def_ids",
5115 &mut *cx.trait_item_def_ids.borrow_mut(),
5117 Rc::new(csearch::get_trait_item_def_ids(&cx.sess.cstore, id))
5121 pub fn impl_trait_ref<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5122 -> Option<Rc<TraitRef<'tcx>>> {
5123 memoized(&cx.impl_trait_cache, id, |id: ast::DefId| {
5124 if id.krate == ast::LOCAL_CRATE {
5125 debug!("(impl_trait_ref) searching for trait impl {:?}", id);
5126 match cx.map.find(id.node) {
5127 Some(ast_map::NodeItem(item)) => {
5129 ast::ItemImpl(_, _, _, ref opt_trait, _, _) => {
5132 let trait_ref = ty::node_id_to_trait_ref(cx, t.ref_id);
5144 csearch::get_impl_trait(cx, id)
5149 pub fn trait_ref_to_def_id(tcx: &ctxt, tr: &ast::TraitRef) -> ast::DefId {
5150 let def = *tcx.def_map.borrow()
5152 .expect("no def-map entry for trait");
5156 pub fn try_add_builtin_trait(
5158 trait_def_id: ast::DefId,
5159 builtin_bounds: &mut EnumSet<BuiltinBound>)
5162 //! Checks whether `trait_ref` refers to one of the builtin
5163 //! traits, like `Send`, and adds the corresponding
5164 //! bound to the set `builtin_bounds` if so. Returns true if `trait_ref`
5165 //! is a builtin trait.
5167 match tcx.lang_items.to_builtin_kind(trait_def_id) {
5168 Some(bound) => { builtin_bounds.insert(bound); true }
5173 pub fn ty_to_def_id(ty: Ty) -> Option<ast::DefId> {
5176 Some(tt.principal_def_id()),
5179 ty_unboxed_closure(id, _, _) =>
5188 pub struct VariantInfo<'tcx> {
5189 pub args: Vec<Ty<'tcx>>,
5190 pub arg_names: Option<Vec<ast::Ident>>,
5191 pub ctor_ty: Option<Ty<'tcx>>,
5192 pub name: ast::Name,
5198 impl<'tcx> VariantInfo<'tcx> {
5200 /// Creates a new VariantInfo from the corresponding ast representation.
5202 /// Does not do any caching of the value in the type context.
5203 pub fn from_ast_variant(cx: &ctxt<'tcx>,
5204 ast_variant: &ast::Variant,
5205 discriminant: Disr) -> VariantInfo<'tcx> {
5206 let ctor_ty = node_id_to_type(cx, ast_variant.node.id);
5208 match ast_variant.node.kind {
5209 ast::TupleVariantKind(ref args) => {
5210 let arg_tys = if args.len() > 0 {
5211 // the regions in the argument types come from the
5212 // enum def'n, and hence will all be early bound
5213 ty::assert_no_late_bound_regions(cx, &ty_fn_args(ctor_ty))
5218 return VariantInfo {
5221 ctor_ty: Some(ctor_ty),
5222 name: ast_variant.node.name.name,
5223 id: ast_util::local_def(ast_variant.node.id),
5224 disr_val: discriminant,
5225 vis: ast_variant.node.vis
5228 ast::StructVariantKind(ref struct_def) => {
5229 let fields: &[StructField] = &struct_def.fields[];
5231 assert!(fields.len() > 0);
5233 let arg_tys = struct_def.fields.iter()
5234 .map(|field| node_id_to_type(cx, field.node.id)).collect();
5235 let arg_names = fields.iter().map(|field| {
5236 match field.node.kind {
5237 NamedField(ident, _) => ident,
5238 UnnamedField(..) => cx.sess.bug(
5239 "enum_variants: all fields in struct must have a name")
5243 return VariantInfo {
5245 arg_names: Some(arg_names),
5247 name: ast_variant.node.name.name,
5248 id: ast_util::local_def(ast_variant.node.id),
5249 disr_val: discriminant,
5250 vis: ast_variant.node.vis
5257 pub fn substd_enum_variants<'tcx>(cx: &ctxt<'tcx>,
5259 substs: &Substs<'tcx>)
5260 -> Vec<Rc<VariantInfo<'tcx>>> {
5261 enum_variants(cx, id).iter().map(|variant_info| {
5262 let substd_args = variant_info.args.iter()
5263 .map(|aty| aty.subst(cx, substs)).collect::<Vec<_>>();
5265 let substd_ctor_ty = variant_info.ctor_ty.subst(cx, substs);
5267 Rc::new(VariantInfo {
5269 ctor_ty: substd_ctor_ty,
5270 ..(**variant_info).clone()
5275 pub fn item_path_str(cx: &ctxt, id: ast::DefId) -> String {
5276 with_path(cx, id, |path| ast_map::path_to_string(path)).to_string()
5282 TraitDtor(DefId, bool)
5286 pub fn is_present(&self) -> bool {
5288 TraitDtor(..) => true,
5293 pub fn has_drop_flag(&self) -> bool {
5296 &TraitDtor(_, flag) => flag
5301 /* If struct_id names a struct with a dtor, return Some(the dtor's id).
5302 Otherwise return none. */
5303 pub fn ty_dtor(cx: &ctxt, struct_id: DefId) -> DtorKind {
5304 match cx.destructor_for_type.borrow().get(&struct_id) {
5305 Some(&method_def_id) => {
5306 let flag = !has_attr(cx, struct_id, "unsafe_no_drop_flag");
5308 TraitDtor(method_def_id, flag)
5314 pub fn has_dtor(cx: &ctxt, struct_id: DefId) -> bool {
5315 cx.destructor_for_type.borrow().contains_key(&struct_id)
5318 pub fn with_path<T, F>(cx: &ctxt, id: ast::DefId, f: F) -> T where
5319 F: FnOnce(ast_map::PathElems) -> T,
5321 if id.krate == ast::LOCAL_CRATE {
5322 cx.map.with_path(id.node, f)
5324 f(ast_map::Values(csearch::get_item_path(cx, id).iter()).chain(None))
5328 pub fn enum_is_univariant(cx: &ctxt, id: ast::DefId) -> bool {
5329 enum_variants(cx, id).len() == 1
5332 pub fn type_is_empty(cx: &ctxt, ty: Ty) -> bool {
5334 ty_enum(did, _) => (*enum_variants(cx, did)).is_empty(),
5339 pub fn enum_variants<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5340 -> Rc<Vec<Rc<VariantInfo<'tcx>>>> {
5341 memoized(&cx.enum_var_cache, id, |id: ast::DefId| {
5342 if ast::LOCAL_CRATE != id.krate {
5343 Rc::new(csearch::get_enum_variants(cx, id))
5346 Although both this code and check_enum_variants in typeck/check
5347 call eval_const_expr, it should never get called twice for the same
5348 expr, since check_enum_variants also updates the enum_var_cache
5350 match cx.map.get(id.node) {
5351 ast_map::NodeItem(ref item) => {
5353 ast::ItemEnum(ref enum_definition, _) => {
5354 let mut last_discriminant: Option<Disr> = None;
5355 Rc::new(enum_definition.variants.iter().map(|variant| {
5357 let mut discriminant = match last_discriminant {
5358 Some(val) => val + 1,
5359 None => INITIAL_DISCRIMINANT_VALUE
5362 match variant.node.disr_expr {
5364 match const_eval::eval_const_expr_partial(cx, &**e) {
5365 Ok(const_eval::const_int(val)) => {
5366 discriminant = val as Disr
5368 Ok(const_eval::const_uint(val)) => {
5369 discriminant = val as Disr
5374 "expected signed integer constant");
5379 &format!("expected constant: {}",
5386 last_discriminant = Some(discriminant);
5387 Rc::new(VariantInfo::from_ast_variant(cx, &**variant,
5392 cx.sess.bug("enum_variants: id not bound to an enum")
5396 _ => cx.sess.bug("enum_variants: id not bound to an enum")
5402 // Returns information about the enum variant with the given ID:
5403 pub fn enum_variant_with_id<'tcx>(cx: &ctxt<'tcx>,
5404 enum_id: ast::DefId,
5405 variant_id: ast::DefId)
5406 -> Rc<VariantInfo<'tcx>> {
5407 enum_variants(cx, enum_id).iter()
5408 .find(|variant| variant.id == variant_id)
5409 .expect("enum_variant_with_id(): no variant exists with that ID")
5414 // If the given item is in an external crate, looks up its type and adds it to
5415 // the type cache. Returns the type parameters and type.
5416 pub fn lookup_item_type<'tcx>(cx: &ctxt<'tcx>,
5418 -> TypeScheme<'tcx> {
5419 lookup_locally_or_in_crate_store(
5420 "tcache", did, &mut *cx.tcache.borrow_mut(),
5421 || csearch::get_type(cx, did))
5424 /// Given the did of a trait, returns its canonical trait ref.
5425 pub fn lookup_trait_def<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId)
5426 -> Rc<ty::TraitDef<'tcx>> {
5427 memoized(&cx.trait_defs, did, |did: DefId| {
5428 assert!(did.krate != ast::LOCAL_CRATE);
5429 Rc::new(csearch::get_trait_def(cx, did))
5433 /// Given a reference to a trait, returns the "superbounds" declared
5434 /// on the trait, with appropriate substitutions applied. Basically,
5435 /// this applies a filter to the where clauses on the trait, returning
5436 /// those that have the form:
5438 /// Self : SuperTrait<...>
5440 pub fn predicates_for_trait_ref<'tcx>(tcx: &ctxt<'tcx>,
5441 trait_ref: &PolyTraitRef<'tcx>)
5442 -> Vec<ty::Predicate<'tcx>>
5444 let trait_def = lookup_trait_def(tcx, trait_ref.def_id());
5446 debug!("bounds_for_trait_ref(trait_def={:?}, trait_ref={:?})",
5447 trait_def.repr(tcx), trait_ref.repr(tcx));
5449 // The interaction between HRTB and supertraits is not entirely
5450 // obvious. Let me walk you (and myself) through an example.
5452 // Let's start with an easy case. Consider two traits:
5454 // trait Foo<'a> : Bar<'a,'a> { }
5455 // trait Bar<'b,'c> { }
5457 // Now, if we have a trait reference `for<'x> T : Foo<'x>`, then
5458 // we can deduce that `for<'x> T : Bar<'x,'x>`. Basically, if we
5459 // knew that `Foo<'x>` (for any 'x) then we also know that
5460 // `Bar<'x,'x>` (for any 'x). This more-or-less falls out from
5461 // normal substitution.
5463 // In terms of why this is sound, the idea is that whenever there
5464 // is an impl of `T:Foo<'a>`, it must show that `T:Bar<'a,'a>`
5465 // holds. So if there is an impl of `T:Foo<'a>` that applies to
5466 // all `'a`, then we must know that `T:Bar<'a,'a>` holds for all
5469 // Another example to be careful of is this:
5471 // trait Foo1<'a> : for<'b> Bar1<'a,'b> { }
5472 // trait Bar1<'b,'c> { }
5474 // Here, if we have `for<'x> T : Foo1<'x>`, then what do we know?
5475 // The answer is that we know `for<'x,'b> T : Bar1<'x,'b>`. The
5476 // reason is similar to the previous example: any impl of
5477 // `T:Foo1<'x>` must show that `for<'b> T : Bar1<'x, 'b>`. So
5478 // basically we would want to collapse the bound lifetimes from
5479 // the input (`trait_ref`) and the supertraits.
5481 // To achieve this in practice is fairly straightforward. Let's
5482 // consider the more complicated scenario:
5484 // - We start out with `for<'x> T : Foo1<'x>`. In this case, `'x`
5485 // has a De Bruijn index of 1. We want to produce `for<'x,'b> T : Bar1<'x,'b>`,
5486 // where both `'x` and `'b` would have a DB index of 1.
5487 // The substitution from the input trait-ref is therefore going to be
5488 // `'a => 'x` (where `'x` has a DB index of 1).
5489 // - The super-trait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an
5490 // early-bound parameter and `'b' is a late-bound parameter with a
5492 // - If we replace `'a` with `'x` from the input, it too will have
5493 // a DB index of 1, and thus we'll have `for<'x,'b> Bar1<'x,'b>`
5494 // just as we wanted.
5496 // There is only one catch. If we just apply the substitution `'a
5497 // => 'x` to `for<'b> Bar1<'a,'b>`, the substitution code will
5498 // adjust the DB index because we substituting into a binder (it
5499 // tries to be so smart...) resulting in `for<'x> for<'b>
5500 // Bar1<'x,'b>` (we have no syntax for this, so use your
5501 // imagination). Basically the 'x will have DB index of 2 and 'b
5502 // will have DB index of 1. Not quite what we want. So we apply
5503 // the substitution to the *contents* of the trait reference,
5504 // rather than the trait reference itself (put another way, the
5505 // substitution code expects equal binding levels in the values
5506 // from the substitution and the value being substituted into, and
5507 // this trick achieves that).
5509 // Carefully avoid the binder introduced by each trait-ref by
5510 // substituting over the substs, not the trait-refs themselves,
5511 // thus achieving the "collapse" described in the big comment
5513 let trait_bounds: Vec<_> =
5514 trait_def.bounds.trait_bounds
5516 .map(|poly_trait_ref| ty::Binder(poly_trait_ref.0.subst(tcx, trait_ref.substs())))
5519 let projection_bounds: Vec<_> =
5520 trait_def.bounds.projection_bounds
5522 .map(|poly_proj| ty::Binder(poly_proj.0.subst(tcx, trait_ref.substs())))
5525 debug!("bounds_for_trait_ref: trait_bounds={} projection_bounds={}",
5526 trait_bounds.repr(tcx),
5527 projection_bounds.repr(tcx));
5529 // The region bounds and builtin bounds do not currently introduce
5530 // binders so we can just substitute in a straightforward way here.
5532 trait_def.bounds.region_bounds.subst(tcx, trait_ref.substs());
5533 let builtin_bounds =
5534 trait_def.bounds.builtin_bounds.subst(tcx, trait_ref.substs());
5536 let bounds = ty::ParamBounds {
5537 trait_bounds: trait_bounds,
5538 region_bounds: region_bounds,
5539 builtin_bounds: builtin_bounds,
5540 projection_bounds: projection_bounds,
5543 predicates(tcx, trait_ref.self_ty(), &bounds)
5546 pub fn predicates<'tcx>(
5549 bounds: &ParamBounds<'tcx>)
5550 -> Vec<Predicate<'tcx>>
5552 let mut vec = Vec::new();
5554 for builtin_bound in bounds.builtin_bounds.iter() {
5555 match traits::trait_ref_for_builtin_bound(tcx, builtin_bound, param_ty) {
5556 Ok(trait_ref) => { vec.push(trait_ref.as_predicate()); }
5557 Err(ErrorReported) => { }
5561 for ®ion_bound in bounds.region_bounds.iter() {
5562 // account for the binder being introduced below; no need to shift `param_ty`
5563 // because, at present at least, it can only refer to early-bound regions
5564 let region_bound = ty_fold::shift_region(region_bound, 1);
5565 vec.push(ty::Binder(ty::OutlivesPredicate(param_ty, region_bound)).as_predicate());
5568 for bound_trait_ref in bounds.trait_bounds.iter() {
5569 vec.push(bound_trait_ref.as_predicate());
5572 for projection in bounds.projection_bounds.iter() {
5573 vec.push(projection.as_predicate());
5579 /// Get the attributes of a definition.
5580 pub fn get_attrs<'tcx>(tcx: &'tcx ctxt, did: DefId)
5581 -> CowVec<'tcx, ast::Attribute> {
5583 let item = tcx.map.expect_item(did.node);
5584 Cow::Borrowed(&item.attrs[])
5586 Cow::Owned(csearch::get_item_attrs(&tcx.sess.cstore, did))
5590 /// Determine whether an item is annotated with an attribute
5591 pub fn has_attr(tcx: &ctxt, did: DefId, attr: &str) -> bool {
5592 get_attrs(tcx, did).iter().any(|item| item.check_name(attr))
5595 /// Determine whether an item is annotated with `#[repr(packed)]`
5596 pub fn lookup_packed(tcx: &ctxt, did: DefId) -> bool {
5597 lookup_repr_hints(tcx, did).contains(&attr::ReprPacked)
5600 /// Determine whether an item is annotated with `#[simd]`
5601 pub fn lookup_simd(tcx: &ctxt, did: DefId) -> bool {
5602 has_attr(tcx, did, "simd")
5605 /// Obtain the representation annotation for a struct definition.
5606 pub fn lookup_repr_hints(tcx: &ctxt, did: DefId) -> Rc<Vec<attr::ReprAttr>> {
5607 memoized(&tcx.repr_hint_cache, did, |did: DefId| {
5608 Rc::new(if did.krate == LOCAL_CRATE {
5609 get_attrs(tcx, did).iter().flat_map(|meta| {
5610 attr::find_repr_attrs(tcx.sess.diagnostic(), meta).into_iter()
5613 csearch::get_repr_attrs(&tcx.sess.cstore, did)
5618 // Look up a field ID, whether or not it's local
5619 // Takes a list of type substs in case the struct is generic
5620 pub fn lookup_field_type<'tcx>(tcx: &ctxt<'tcx>,
5623 substs: &Substs<'tcx>)
5625 let ty = if id.krate == ast::LOCAL_CRATE {
5626 node_id_to_type(tcx, id.node)
5628 let mut tcache = tcx.tcache.borrow_mut();
5629 let pty = tcache.entry(id).get().unwrap_or_else(
5630 |vacant_entry| vacant_entry.insert(csearch::get_field_type(tcx, struct_id, id)));
5633 ty.subst(tcx, substs)
5636 // Look up the list of field names and IDs for a given struct.
5637 // Panics if the id is not bound to a struct.
5638 pub fn lookup_struct_fields(cx: &ctxt, did: ast::DefId) -> Vec<field_ty> {
5639 if did.krate == ast::LOCAL_CRATE {
5640 let struct_fields = cx.struct_fields.borrow();
5641 match struct_fields.get(&did) {
5642 Some(fields) => (**fields).clone(),
5645 &format!("ID not mapped to struct fields: {}",
5646 cx.map.node_to_string(did.node))[]);
5650 csearch::get_struct_fields(&cx.sess.cstore, did)
5654 pub fn is_tuple_struct(cx: &ctxt, did: ast::DefId) -> bool {
5655 let fields = lookup_struct_fields(cx, did);
5656 !fields.is_empty() && fields.iter().all(|f| f.name == token::special_names::unnamed_field)
5659 // Returns a list of fields corresponding to the struct's items. trans uses
5660 // this. Takes a list of substs with which to instantiate field types.
5661 pub fn struct_fields<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId, substs: &Substs<'tcx>)
5662 -> Vec<field<'tcx>> {
5663 lookup_struct_fields(cx, did).iter().map(|f| {
5667 ty: lookup_field_type(cx, did, f.id, substs),
5674 // Returns a list of fields corresponding to the tuple's items. trans uses
5676 pub fn tup_fields<'tcx>(v: &[Ty<'tcx>]) -> Vec<field<'tcx>> {
5677 v.iter().enumerate().map(|(i, &f)| {
5679 name: token::intern(&i.to_string()[]),
5688 #[derive(Copy, Clone)]
5689 pub struct UnboxedClosureUpvar<'tcx> {
5695 // Returns a list of `UnboxedClosureUpvar`s for each upvar.
5696 pub fn unboxed_closure_upvars<'tcx>(typer: &mc::Typer<'tcx>,
5697 closure_id: ast::DefId,
5698 substs: &Substs<'tcx>)
5699 -> Option<Vec<UnboxedClosureUpvar<'tcx>>>
5701 // Presently an unboxed closure type cannot "escape" out of a
5702 // function, so we will only encounter ones that originated in the
5703 // local crate or were inlined into it along with some function.
5704 // This may change if abstract return types of some sort are
5706 assert!(closure_id.krate == ast::LOCAL_CRATE);
5707 let tcx = typer.tcx();
5708 let capture_mode = tcx.capture_modes.borrow()[closure_id.node].clone();
5709 match tcx.freevars.borrow().get(&closure_id.node) {
5710 None => Some(vec![]),
5711 Some(ref freevars) => {
5714 let freevar_def_id = freevar.def.def_id();
5715 let freevar_ty = match typer.node_ty(freevar_def_id.node) {
5717 Err(()) => { return None; }
5719 let freevar_ty = freevar_ty.subst(tcx, substs);
5721 match capture_mode {
5722 ast::CaptureByValue => {
5723 Some(UnboxedClosureUpvar { def: freevar.def,
5728 ast::CaptureByRef => {
5729 let upvar_id = ty::UpvarId {
5730 var_id: freevar_def_id.node,
5731 closure_expr_id: closure_id.node
5735 let freevar_ref_ty = match typer.upvar_borrow(upvar_id) {
5738 tcx.mk_region(borrow.region),
5741 mutbl: borrow.kind.to_mutbl_lossy(),
5745 // FIXME(#16640) we should really return None here;
5746 // but that requires better inference integration,
5747 // for now gin up something.
5751 Some(UnboxedClosureUpvar {
5764 pub fn is_binopable<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>, op: ast::BinOp) -> bool {
5765 #![allow(non_upper_case_globals)]
5766 static tycat_other: int = 0;
5767 static tycat_bool: int = 1;
5768 static tycat_char: int = 2;
5769 static tycat_int: int = 3;
5770 static tycat_float: int = 4;
5771 static tycat_raw_ptr: int = 6;
5773 static opcat_add: int = 0;
5774 static opcat_sub: int = 1;
5775 static opcat_mult: int = 2;
5776 static opcat_shift: int = 3;
5777 static opcat_rel: int = 4;
5778 static opcat_eq: int = 5;
5779 static opcat_bit: int = 6;
5780 static opcat_logic: int = 7;
5781 static opcat_mod: int = 8;
5783 fn opcat(op: ast::BinOp) -> int {
5785 ast::BiAdd => opcat_add,
5786 ast::BiSub => opcat_sub,
5787 ast::BiMul => opcat_mult,
5788 ast::BiDiv => opcat_mult,
5789 ast::BiRem => opcat_mod,
5790 ast::BiAnd => opcat_logic,
5791 ast::BiOr => opcat_logic,
5792 ast::BiBitXor => opcat_bit,
5793 ast::BiBitAnd => opcat_bit,
5794 ast::BiBitOr => opcat_bit,
5795 ast::BiShl => opcat_shift,
5796 ast::BiShr => opcat_shift,
5797 ast::BiEq => opcat_eq,
5798 ast::BiNe => opcat_eq,
5799 ast::BiLt => opcat_rel,
5800 ast::BiLe => opcat_rel,
5801 ast::BiGe => opcat_rel,
5802 ast::BiGt => opcat_rel
5806 fn tycat<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> int {
5807 if type_is_simd(cx, ty) {
5808 return tycat(cx, simd_type(cx, ty))
5811 ty_char => tycat_char,
5812 ty_bool => tycat_bool,
5813 ty_int(_) | ty_uint(_) | ty_infer(IntVar(_)) => tycat_int,
5814 ty_float(_) | ty_infer(FloatVar(_)) => tycat_float,
5815 ty_ptr(_) => tycat_raw_ptr,
5820 static t: bool = true;
5821 static f: bool = false;
5824 // +, -, *, shift, rel, ==, bit, logic, mod
5825 /*other*/ [f, f, f, f, f, f, f, f, f],
5826 /*bool*/ [f, f, f, f, t, t, t, t, f],
5827 /*char*/ [f, f, f, f, t, t, f, f, f],
5828 /*int*/ [t, t, t, t, t, t, t, f, t],
5829 /*float*/ [t, t, t, f, t, t, f, f, f],
5830 /*bot*/ [t, t, t, t, t, t, t, t, t],
5831 /*raw ptr*/ [f, f, f, f, t, t, f, f, f]];
5833 return tbl[tycat(cx, ty) as uint ][opcat(op) as uint];
5836 // Returns the repeat count for a repeating vector expression.
5837 pub fn eval_repeat_count(tcx: &ctxt, count_expr: &ast::Expr) -> uint {
5838 match const_eval::eval_const_expr_partial(tcx, count_expr) {
5840 let found = match val {
5841 const_eval::const_uint(count) => return count as uint,
5842 const_eval::const_int(count) if count >= 0 => return count as uint,
5843 const_eval::const_int(_) =>
5845 const_eval::const_float(_) =>
5847 const_eval::const_str(_) =>
5849 const_eval::const_bool(_) =>
5851 const_eval::const_binary(_) =>
5854 tcx.sess.span_err(count_expr.span, &format!(
5855 "expected positive integer for repeat count, found {}",
5859 let found = match count_expr.node {
5860 ast::ExprPath(ast::Path {
5864 }) if segments.len() == 1 =>
5867 "non-constant expression"
5869 tcx.sess.span_err(count_expr.span, &format!(
5870 "expected constant integer for repeat count, found {}",
5877 // Iterate over a type parameter's bounded traits and any supertraits
5878 // of those traits, ignoring kinds.
5879 // Here, the supertraits are the transitive closure of the supertrait
5880 // relation on the supertraits from each bounded trait's constraint
5882 pub fn each_bound_trait_and_supertraits<'tcx, F>(tcx: &ctxt<'tcx>,
5883 bounds: &[PolyTraitRef<'tcx>],
5886 F: FnMut(PolyTraitRef<'tcx>) -> bool,
5888 for bound_trait_ref in traits::transitive_bounds(tcx, bounds) {
5889 if !f(bound_trait_ref) {
5896 pub fn object_region_bounds<'tcx>(
5898 opt_principal: Option<&PolyTraitRef<'tcx>>, // None for closures
5899 others: BuiltinBounds)
5902 // Since we don't actually *know* the self type for an object,
5903 // this "open(err)" serves as a kind of dummy standin -- basically
5904 // a skolemized type.
5905 let open_ty = ty::mk_infer(tcx, FreshTy(0));
5907 let opt_trait_ref = opt_principal.map_or(Vec::new(), |principal| {
5908 // Note that we preserve the overall binding levels here.
5909 assert!(!open_ty.has_escaping_regions());
5910 let substs = tcx.mk_substs(principal.0.substs.with_self_ty(open_ty));
5911 vec!(ty::Binder(Rc::new(ty::TraitRef::new(principal.0.def_id, substs))))
5914 let param_bounds = ty::ParamBounds {
5915 region_bounds: Vec::new(),
5916 builtin_bounds: others,
5917 trait_bounds: opt_trait_ref,
5918 projection_bounds: Vec::new(), // not relevant to computing region bounds
5921 let predicates = ty::predicates(tcx, open_ty, ¶m_bounds);
5922 ty::required_region_bounds(tcx, open_ty, predicates)
5925 /// Given a set of predicates that apply to an object type, returns
5926 /// the region bounds that the (erased) `Self` type must
5927 /// outlive. Precisely *because* the `Self` type is erased, the
5928 /// parameter `erased_self_ty` must be supplied to indicate what type
5929 /// has been used to represent `Self` in the predicates
5930 /// themselves. This should really be a unique type; `FreshTy(0)` is a
5931 /// popular choice (see `object_region_bounds` above).
5933 /// Requires that trait definitions have been processed so that we can
5934 /// elaborate predicates and walk supertraits.
5935 pub fn required_region_bounds<'tcx>(tcx: &ctxt<'tcx>,
5936 erased_self_ty: Ty<'tcx>,
5937 predicates: Vec<ty::Predicate<'tcx>>)
5940 debug!("required_region_bounds(erased_self_ty={:?}, predicates={:?})",
5941 erased_self_ty.repr(tcx),
5942 predicates.repr(tcx));
5944 assert!(!erased_self_ty.has_escaping_regions());
5946 traits::elaborate_predicates(tcx, predicates)
5947 .filter_map(|predicate| {
5949 ty::Predicate::Projection(..) |
5950 ty::Predicate::Trait(..) |
5951 ty::Predicate::Equate(..) |
5952 ty::Predicate::RegionOutlives(..) => {
5955 ty::Predicate::TypeOutlives(ty::Binder(ty::OutlivesPredicate(t, r))) => {
5956 // Search for a bound of the form `erased_self_ty
5957 // : 'a`, but be wary of something like `for<'a>
5958 // erased_self_ty : 'a` (we interpret a
5959 // higher-ranked bound like that as 'static,
5960 // though at present the code in `fulfill.rs`
5961 // considers such bounds to be unsatisfiable, so
5962 // it's kind of a moot point since you could never
5963 // construct such an object, but this seems
5964 // correct even if that code changes).
5965 if t == erased_self_ty && !r.has_escaping_regions() {
5966 if r.has_escaping_regions() {
5980 pub fn get_tydesc_ty<'tcx>(tcx: &ctxt<'tcx>) -> Result<Ty<'tcx>, String> {
5981 tcx.lang_items.require(TyDescStructLangItem).map(|tydesc_lang_item| {
5982 tcx.intrinsic_defs.borrow().get(&tydesc_lang_item).cloned()
5983 .expect("Failed to resolve TyDesc")
5987 pub fn item_variances(tcx: &ctxt, item_id: ast::DefId) -> Rc<ItemVariances> {
5988 lookup_locally_or_in_crate_store(
5989 "item_variance_map", item_id, &mut *tcx.item_variance_map.borrow_mut(),
5990 || Rc::new(csearch::get_item_variances(&tcx.sess.cstore, item_id)))
5993 /// Records a trait-to-implementation mapping.
5994 pub fn record_trait_implementation(tcx: &ctxt,
5995 trait_def_id: DefId,
5996 impl_def_id: DefId) {
5998 match tcx.trait_impls.borrow().get(&trait_def_id) {
5999 Some(impls_for_trait) => {
6000 impls_for_trait.borrow_mut().push(impl_def_id);
6006 tcx.trait_impls.borrow_mut().insert(trait_def_id, Rc::new(RefCell::new(vec!(impl_def_id))));
6009 /// Populates the type context with all the implementations for the given type
6011 pub fn populate_implementations_for_type_if_necessary(tcx: &ctxt,
6012 type_id: ast::DefId) {
6013 if type_id.krate == LOCAL_CRATE {
6016 if tcx.populated_external_types.borrow().contains(&type_id) {
6020 debug!("populate_implementations_for_type_if_necessary: searching for {:?}", type_id);
6022 let mut inherent_impls = Vec::new();
6023 csearch::each_implementation_for_type(&tcx.sess.cstore, type_id,
6025 let impl_items = csearch::get_impl_items(&tcx.sess.cstore, impl_def_id);
6027 // Record the trait->implementation mappings, if applicable.
6028 let associated_traits = csearch::get_impl_trait(tcx, impl_def_id);
6029 for trait_ref in associated_traits.iter() {
6030 record_trait_implementation(tcx, trait_ref.def_id, impl_def_id);
6033 // For any methods that use a default implementation, add them to
6034 // the map. This is a bit unfortunate.
6035 for impl_item_def_id in impl_items.iter() {
6036 let method_def_id = impl_item_def_id.def_id();
6037 match impl_or_trait_item(tcx, method_def_id) {
6038 MethodTraitItem(method) => {
6039 for &source in method.provided_source.iter() {
6040 tcx.provided_method_sources
6042 .insert(method_def_id, source);
6045 TypeTraitItem(_) => {}
6049 // Store the implementation info.
6050 tcx.impl_items.borrow_mut().insert(impl_def_id, impl_items);
6052 // If this is an inherent implementation, record it.
6053 if associated_traits.is_none() {
6054 inherent_impls.push(impl_def_id);
6058 tcx.inherent_impls.borrow_mut().insert(type_id, Rc::new(inherent_impls));
6059 tcx.populated_external_types.borrow_mut().insert(type_id);
6062 /// Populates the type context with all the implementations for the given
6063 /// trait if necessary.
6064 pub fn populate_implementations_for_trait_if_necessary(
6066 trait_id: ast::DefId) {
6067 if trait_id.krate == LOCAL_CRATE {
6070 if tcx.populated_external_traits.borrow().contains(&trait_id) {
6074 csearch::each_implementation_for_trait(&tcx.sess.cstore, trait_id,
6075 |implementation_def_id| {
6076 let impl_items = csearch::get_impl_items(&tcx.sess.cstore, implementation_def_id);
6078 // Record the trait->implementation mapping.
6079 record_trait_implementation(tcx, trait_id, implementation_def_id);
6081 // For any methods that use a default implementation, add them to
6082 // the map. This is a bit unfortunate.
6083 for impl_item_def_id in impl_items.iter() {
6084 let method_def_id = impl_item_def_id.def_id();
6085 match impl_or_trait_item(tcx, method_def_id) {
6086 MethodTraitItem(method) => {
6087 for &source in method.provided_source.iter() {
6088 tcx.provided_method_sources
6090 .insert(method_def_id, source);
6093 TypeTraitItem(_) => {}
6097 // Store the implementation info.
6098 tcx.impl_items.borrow_mut().insert(implementation_def_id, impl_items);
6101 tcx.populated_external_traits.borrow_mut().insert(trait_id);
6104 /// Given the def_id of an impl, return the def_id of the trait it implements.
6105 /// If it implements no trait, return `None`.
6106 pub fn trait_id_of_impl(tcx: &ctxt,
6108 -> Option<ast::DefId> {
6109 ty::impl_trait_ref(tcx, def_id).map(|tr| tr.def_id)
6112 /// If the given def ID describes a method belonging to an impl, return the
6113 /// ID of the impl that the method belongs to. Otherwise, return `None`.
6114 pub fn impl_of_method(tcx: &ctxt, def_id: ast::DefId)
6115 -> Option<ast::DefId> {
6116 if def_id.krate != LOCAL_CRATE {
6117 return match csearch::get_impl_or_trait_item(tcx,
6118 def_id).container() {
6119 TraitContainer(_) => None,
6120 ImplContainer(def_id) => Some(def_id),
6123 match tcx.impl_or_trait_items.borrow().get(&def_id).cloned() {
6124 Some(trait_item) => {
6125 match trait_item.container() {
6126 TraitContainer(_) => None,
6127 ImplContainer(def_id) => Some(def_id),
6134 /// If the given def ID describes an item belonging to a trait (either a
6135 /// default method or an implementation of a trait method), return the ID of
6136 /// the trait that the method belongs to. Otherwise, return `None`.
6137 pub fn trait_of_item(tcx: &ctxt, def_id: ast::DefId) -> Option<ast::DefId> {
6138 if def_id.krate != LOCAL_CRATE {
6139 return csearch::get_trait_of_item(&tcx.sess.cstore, def_id, tcx);
6141 match tcx.impl_or_trait_items.borrow().get(&def_id).cloned() {
6142 Some(impl_or_trait_item) => {
6143 match impl_or_trait_item.container() {
6144 TraitContainer(def_id) => Some(def_id),
6145 ImplContainer(def_id) => trait_id_of_impl(tcx, def_id),
6152 /// If the given def ID describes an item belonging to a trait, (either a
6153 /// default method or an implementation of a trait method), return the ID of
6154 /// the method inside trait definition (this means that if the given def ID
6155 /// is already that of the original trait method, then the return value is
6157 /// Otherwise, return `None`.
6158 pub fn trait_item_of_item(tcx: &ctxt, def_id: ast::DefId)
6159 -> Option<ImplOrTraitItemId> {
6160 let impl_item = match tcx.impl_or_trait_items.borrow().get(&def_id) {
6161 Some(m) => m.clone(),
6162 None => return None,
6164 let name = impl_item.name();
6165 match trait_of_item(tcx, def_id) {
6166 Some(trait_did) => {
6167 let trait_items = ty::trait_items(tcx, trait_did);
6169 .position(|m| m.name() == name)
6170 .map(|idx| ty::trait_item(tcx, trait_did, idx).id())
6176 /// Creates a hash of the type `Ty` which will be the same no matter what crate
6177 /// context it's calculated within. This is used by the `type_id` intrinsic.
6178 pub fn hash_crate_independent<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>, svh: &Svh) -> u64 {
6179 let mut state = SipHasher::new();
6180 helper(tcx, ty, svh, &mut state);
6181 return state.finish();
6183 fn helper<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>, svh: &Svh,
6184 state: &mut SipHasher) {
6185 macro_rules! byte { ($b:expr) => { ($b as u8).hash(state) } }
6186 macro_rules! hash { ($e:expr) => { $e.hash(state) } }
6188 let region = |&: state: &mut SipHasher, r: Region| {
6191 ReLateBound(db, BrAnon(i)) => {
6201 tcx.sess.bug("unexpected region found when hashing a type")
6205 let did = |&: state: &mut SipHasher, did: DefId| {
6206 let h = if ast_util::is_local(did) {
6209 tcx.sess.cstore.get_crate_hash(did.krate)
6211 h.as_str().hash(state);
6212 did.node.hash(state);
6214 let mt = |&: state: &mut SipHasher, mt: mt| {
6215 mt.mutbl.hash(state);
6217 let fn_sig = |&: state: &mut SipHasher, sig: &Binder<FnSig<'tcx>>| {
6218 let sig = anonymize_late_bound_regions(tcx, sig).0;
6219 for a in sig.inputs.iter() { helper(tcx, *a, svh, state); }
6220 if let ty::FnConverging(output) = sig.output {
6221 helper(tcx, output, svh, state);
6224 maybe_walk_ty(ty, |ty| {
6226 ty_bool => byte!(2),
6227 ty_char => byte!(3),
6250 ty_vec(_, Some(n)) => {
6254 ty_vec(_, None) => {
6266 ty_bare_fn(opt_def_id, ref b) => {
6271 fn_sig(state, &b.sig);
6274 ty_trait(ref data) => {
6276 did(state, data.principal_def_id());
6279 let principal = anonymize_late_bound_regions(tcx, &data.principal).0;
6280 for subty in principal.substs.types.iter() {
6281 helper(tcx, *subty, svh, state);
6286 ty_struct(d, _) => {
6290 ty_tup(ref inner) => {
6298 hash!(token::get_name(p.name));
6300 ty_open(_) => byte!(22),
6301 ty_infer(_) => unreachable!(),
6302 ty_err => byte!(23),
6303 ty_unboxed_closure(d, r, _) => {
6308 ty_projection(ref data) => {
6310 did(state, data.trait_ref.def_id);
6311 hash!(token::get_name(data.item_name));
6320 pub fn to_string(self) -> &'static str {
6323 Contravariant => "-",
6330 /// Construct a parameter environment suitable for static contexts or other contexts where there
6331 /// are no free type/lifetime parameters in scope.
6332 pub fn empty_parameter_environment<'a,'tcx>(cx: &'a ctxt<'tcx>) -> ParameterEnvironment<'a,'tcx> {
6333 ty::ParameterEnvironment { tcx: cx,
6334 free_substs: Substs::empty(),
6335 caller_bounds: GenericBounds::empty(),
6336 implicit_region_bound: ty::ReEmpty,
6337 selection_cache: traits::SelectionCache::new(), }
6340 /// See `ParameterEnvironment` struct def'n for details
6341 pub fn construct_parameter_environment<'a,'tcx>(
6342 tcx: &'a ctxt<'tcx>,
6343 generics: &ty::Generics<'tcx>,
6344 free_id: ast::NodeId)
6345 -> ParameterEnvironment<'a, 'tcx>
6349 // Construct the free substs.
6353 let mut types = VecPerParamSpace::empty();
6354 push_types_from_defs(tcx, &mut types, generics.types.as_slice());
6356 // map bound 'a => free 'a
6357 let mut regions = VecPerParamSpace::empty();
6358 push_region_params(&mut regions, free_id, generics.regions.as_slice());
6360 let free_substs = Substs {
6362 regions: subst::NonerasedRegions(regions)
6365 let free_id_scope = region::CodeExtent::from_node_id(free_id);
6368 // Compute the bounds on Self and the type parameters.
6371 let bounds = generics.to_bounds(tcx, &free_substs);
6372 let bounds = liberate_late_bound_regions(tcx, free_id_scope, &ty::Binder(bounds));
6375 // Compute region bounds. For now, these relations are stored in a
6376 // global table on the tcx, so just enter them there. I'm not
6377 // crazy about this scheme, but it's convenient, at least.
6380 record_region_bounds(tcx, &bounds);
6382 debug!("construct_parameter_environment: free_id={:?} free_subst={:?} bounds={:?}",
6384 free_substs.repr(tcx),
6387 return ty::ParameterEnvironment {
6389 free_substs: free_substs,
6390 implicit_region_bound: ty::ReScope(free_id_scope),
6391 caller_bounds: bounds,
6392 selection_cache: traits::SelectionCache::new(),
6395 fn push_region_params(regions: &mut VecPerParamSpace<ty::Region>,
6396 free_id: ast::NodeId,
6397 region_params: &[RegionParameterDef])
6399 for r in region_params.iter() {
6400 regions.push(r.space, ty::free_region_from_def(free_id, r));
6404 fn push_types_from_defs<'tcx>(tcx: &ty::ctxt<'tcx>,
6405 types: &mut VecPerParamSpace<Ty<'tcx>>,
6406 defs: &[TypeParameterDef<'tcx>]) {
6407 for def in defs.iter() {
6408 debug!("construct_parameter_environment(): push_types_from_defs: def={:?}",
6410 let ty = ty::mk_param_from_def(tcx, def);
6411 types.push(def.space, ty);
6415 fn record_region_bounds<'tcx>(tcx: &ty::ctxt<'tcx>, bounds: &GenericBounds<'tcx>) {
6416 debug!("record_region_bounds(bounds={:?})", bounds.repr(tcx));
6418 for predicate in bounds.predicates.iter() {
6420 Predicate::Projection(..) |
6421 Predicate::Trait(..) |
6422 Predicate::Equate(..) |
6423 Predicate::TypeOutlives(..) => {
6424 // No region bounds here
6426 Predicate::RegionOutlives(ty::Binder(ty::OutlivesPredicate(r_a, r_b))) => {
6428 (ty::ReFree(fr_a), ty::ReFree(fr_b)) => {
6429 // Record that `'a:'b`. Or, put another way, `'b <= 'a`.
6430 tcx.region_maps.relate_free_regions(fr_b, fr_a);
6433 // All named regions are instantiated with free regions.
6435 format!("record_region_bounds: non free region: {} / {}",
6437 r_b.repr(tcx)).as_slice());
6447 pub fn from_mutbl(m: ast::Mutability) -> BorrowKind {
6449 ast::MutMutable => MutBorrow,
6450 ast::MutImmutable => ImmBorrow,
6454 /// Returns a mutability `m` such that an `&m T` pointer could be used to obtain this borrow
6455 /// kind. Because borrow kinds are richer than mutabilities, we sometimes have to pick a
6456 /// mutability that is stronger than necessary so that it at least *would permit* the borrow in
6458 pub fn to_mutbl_lossy(self) -> ast::Mutability {
6460 MutBorrow => ast::MutMutable,
6461 ImmBorrow => ast::MutImmutable,
6463 // We have no type corresponding to a unique imm borrow, so
6464 // use `&mut`. It gives all the capabilities of an `&uniq`
6465 // and hence is a safe "over approximation".
6466 UniqueImmBorrow => ast::MutMutable,
6470 pub fn to_user_str(&self) -> &'static str {
6472 MutBorrow => "mutable",
6473 ImmBorrow => "immutable",
6474 UniqueImmBorrow => "uniquely immutable",
6479 impl<'tcx> ctxt<'tcx> {
6480 pub fn capture_mode(&self, closure_expr_id: ast::NodeId)
6481 -> ast::CaptureClause {
6482 self.capture_modes.borrow()[closure_expr_id].clone()
6485 pub fn is_method_call(&self, expr_id: ast::NodeId) -> bool {
6486 self.method_map.borrow().contains_key(&MethodCall::expr(expr_id))
6490 impl<'a,'tcx> mc::Typer<'tcx> for ParameterEnvironment<'a,'tcx> {
6491 fn tcx(&self) -> &ty::ctxt<'tcx> {
6495 fn node_ty(&self, id: ast::NodeId) -> mc::McResult<Ty<'tcx>> {
6496 Ok(ty::node_id_to_type(self.tcx, id))
6499 fn expr_ty_adjusted(&self, expr: &ast::Expr) -> mc::McResult<Ty<'tcx>> {
6500 Ok(ty::expr_ty_adjusted(self.tcx, expr))
6503 fn node_method_ty(&self, method_call: ty::MethodCall) -> Option<Ty<'tcx>> {
6504 self.tcx.method_map.borrow().get(&method_call).map(|method| method.ty)
6507 fn node_method_origin(&self, method_call: ty::MethodCall)
6508 -> Option<ty::MethodOrigin<'tcx>>
6510 self.tcx.method_map.borrow().get(&method_call).map(|method| method.origin.clone())
6513 fn adjustments(&self) -> &RefCell<NodeMap<ty::AutoAdjustment<'tcx>>> {
6514 &self.tcx.adjustments
6517 fn is_method_call(&self, id: ast::NodeId) -> bool {
6518 self.tcx.is_method_call(id)
6521 fn temporary_scope(&self, rvalue_id: ast::NodeId) -> Option<region::CodeExtent> {
6522 self.tcx.region_maps.temporary_scope(rvalue_id)
6525 fn upvar_borrow(&self, upvar_id: ty::UpvarId) -> Option<ty::UpvarBorrow> {
6526 Some(self.tcx.upvar_borrow_map.borrow()[upvar_id].clone())
6529 fn capture_mode(&self, closure_expr_id: ast::NodeId)
6530 -> ast::CaptureClause {
6531 self.tcx.capture_mode(closure_expr_id)
6534 fn type_moves_by_default(&self, span: Span, ty: Ty<'tcx>) -> bool {
6535 type_moves_by_default(self, span, ty)
6539 impl<'a,'tcx> UnboxedClosureTyper<'tcx> for ty::ParameterEnvironment<'a,'tcx> {
6540 fn param_env<'b>(&'b self) -> &'b ty::ParameterEnvironment<'b,'tcx> {
6544 fn unboxed_closure_kind(&self,
6546 -> ty::UnboxedClosureKind
6548 self.tcx.unboxed_closure_kind(def_id)
6551 fn unboxed_closure_type(&self,
6553 substs: &subst::Substs<'tcx>)
6554 -> ty::ClosureTy<'tcx>
6556 self.tcx.unboxed_closure_type(def_id, substs)
6559 fn unboxed_closure_upvars(&self,
6561 substs: &Substs<'tcx>)
6562 -> Option<Vec<UnboxedClosureUpvar<'tcx>>>
6564 unboxed_closure_upvars(self, def_id, substs)
6569 /// The category of explicit self.
6570 #[derive(Clone, Copy, Eq, PartialEq, Show)]
6571 pub enum ExplicitSelfCategory {
6572 StaticExplicitSelfCategory,
6573 ByValueExplicitSelfCategory,
6574 ByReferenceExplicitSelfCategory(Region, ast::Mutability),
6575 ByBoxExplicitSelfCategory,
6578 /// Pushes all the lifetimes in the given type onto the given list. A
6579 /// "lifetime in a type" is a lifetime specified by a reference or a lifetime
6580 /// in a list of type substitutions. This does *not* traverse into nominal
6581 /// types, nor does it resolve fictitious types.
6582 pub fn accumulate_lifetimes_in_type(accumulator: &mut Vec<ty::Region>,
6586 ty_rptr(region, _) => {
6587 accumulator.push(*region)
6589 ty_trait(ref t) => {
6590 accumulator.push_all(t.principal.0.substs.regions().as_slice());
6592 ty_enum(_, substs) |
6593 ty_struct(_, substs) => {
6594 accum_substs(accumulator, substs);
6596 ty_unboxed_closure(_, region, substs) => {
6597 accumulator.push(*region);
6598 accum_substs(accumulator, substs);
6620 fn accum_substs(accumulator: &mut Vec<Region>, substs: &Substs) {
6621 match substs.regions {
6622 subst::ErasedRegions => {}
6623 subst::NonerasedRegions(ref regions) => {
6624 for region in regions.iter() {
6625 accumulator.push(*region)
6632 /// A free variable referred to in a function.
6633 #[derive(Copy, RustcEncodable, RustcDecodable)]
6634 pub struct Freevar {
6635 /// The variable being accessed free.
6638 // First span where it is accessed (there can be multiple).
6642 pub type FreevarMap = NodeMap<Vec<Freevar>>;
6644 pub type CaptureModeMap = NodeMap<ast::CaptureClause>;
6646 // Trait method resolution
6647 pub type TraitMap = NodeMap<Vec<DefId>>;
6649 // Map from the NodeId of a glob import to a list of items which are actually
6651 pub type GlobMap = HashMap<NodeId, HashSet<Name>>;
6653 pub fn with_freevars<T, F>(tcx: &ty::ctxt, fid: ast::NodeId, f: F) -> T where
6654 F: FnOnce(&[Freevar]) -> T,
6656 match tcx.freevars.borrow().get(&fid) {
6662 impl<'tcx> AutoAdjustment<'tcx> {
6663 pub fn is_identity(&self) -> bool {
6665 AdjustReifyFnPointer(..) => false,
6666 AdjustDerefRef(ref r) => r.is_identity(),
6671 impl<'tcx> AutoDerefRef<'tcx> {
6672 pub fn is_identity(&self) -> bool {
6673 self.autoderefs == 0 && self.autoref.is_none()
6677 /// Replace any late-bound regions bound in `value` with free variants attached to scope-id
6679 pub fn liberate_late_bound_regions<'tcx, T>(
6680 tcx: &ty::ctxt<'tcx>,
6681 scope: region::CodeExtent,
6684 where T : TypeFoldable<'tcx> + Repr<'tcx>
6686 replace_late_bound_regions(
6688 |br| ty::ReFree(ty::FreeRegion{scope: scope, bound_region: br})).0
6691 pub fn count_late_bound_regions<'tcx, T>(
6692 tcx: &ty::ctxt<'tcx>,
6695 where T : TypeFoldable<'tcx> + Repr<'tcx>
6697 let (_, skol_map) = replace_late_bound_regions(tcx, value, |_| ty::ReStatic);
6701 pub fn binds_late_bound_regions<'tcx, T>(
6702 tcx: &ty::ctxt<'tcx>,
6705 where T : TypeFoldable<'tcx> + Repr<'tcx>
6707 count_late_bound_regions(tcx, value) > 0
6710 pub fn assert_no_late_bound_regions<'tcx, T>(
6711 tcx: &ty::ctxt<'tcx>,
6714 where T : TypeFoldable<'tcx> + Repr<'tcx> + Clone
6716 assert!(!binds_late_bound_regions(tcx, value));
6720 /// Replace any late-bound regions bound in `value` with `'static`. Useful in trans but also
6721 /// method lookup and a few other places where precise region relationships are not required.
6722 pub fn erase_late_bound_regions<'tcx, T>(
6723 tcx: &ty::ctxt<'tcx>,
6726 where T : TypeFoldable<'tcx> + Repr<'tcx>
6728 replace_late_bound_regions(tcx, value, |_| ty::ReStatic).0
6731 /// Rewrite any late-bound regions so that they are anonymous. Region numbers are
6732 /// assigned starting at 1 and increasing monotonically in the order traversed
6733 /// by the fold operation.
6735 /// The chief purpose of this function is to canonicalize regions so that two
6736 /// `FnSig`s or `TraitRef`s which are equivalent up to region naming will become
6737 /// structurally identical. For example, `for<'a, 'b> fn(&'a int, &'b int)` and
6738 /// `for<'a, 'b> fn(&'b int, &'a int)` will become identical after anonymization.
6739 pub fn anonymize_late_bound_regions<'tcx, T>(
6743 where T : TypeFoldable<'tcx> + Repr<'tcx>,
6745 let mut counter = 0;
6746 ty::Binder(replace_late_bound_regions(tcx, sig, |_| {
6748 ReLateBound(ty::DebruijnIndex::new(1), BrAnon(counter))
6752 /// Replaces the late-bound-regions in `value` that are bound by `value`.
6753 pub fn replace_late_bound_regions<'tcx, T, F>(
6754 tcx: &ty::ctxt<'tcx>,
6757 -> (T, FnvHashMap<ty::BoundRegion,ty::Region>)
6758 where T : TypeFoldable<'tcx> + Repr<'tcx>,
6759 F : FnMut(BoundRegion) -> ty::Region,
6761 debug!("replace_late_bound_regions({})", binder.repr(tcx));
6763 let mut map = FnvHashMap();
6765 // Note: fold the field `0`, not the binder, so that late-bound
6766 // regions bound by `binder` are considered free.
6767 let value = ty_fold::fold_regions(tcx, &binder.0, |region, current_depth| {
6768 debug!("region={}", region.repr(tcx));
6770 ty::ReLateBound(debruijn, br) if debruijn.depth == current_depth => {
6772 * map.entry(br).get().unwrap_or_else(
6773 |vacant_entry| vacant_entry.insert(mapf(br)));
6775 if let ty::ReLateBound(debruijn1, br) = region {
6776 // If the callback returns a late-bound region,
6777 // that region should always use depth 1. Then we
6778 // adjust it to the correct depth.
6779 assert_eq!(debruijn1.depth, 1);
6780 ty::ReLateBound(debruijn, br)
6791 debug!("resulting map: {:?} value: {:?}", map, value.repr(tcx));
6795 impl DebruijnIndex {
6796 pub fn new(depth: u32) -> DebruijnIndex {
6798 DebruijnIndex { depth: depth }
6801 pub fn shifted(&self, amount: u32) -> DebruijnIndex {
6802 DebruijnIndex { depth: self.depth + amount }
6806 impl<'tcx> Repr<'tcx> for AutoAdjustment<'tcx> {
6807 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6809 AdjustReifyFnPointer(def_id) => {
6810 format!("AdjustReifyFnPointer({})", def_id.repr(tcx))
6812 AdjustDerefRef(ref data) => {
6819 impl<'tcx> Repr<'tcx> for UnsizeKind<'tcx> {
6820 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6822 UnsizeLength(n) => format!("UnsizeLength({})", n),
6823 UnsizeStruct(ref k, n) => format!("UnsizeStruct({},{})", k.repr(tcx), n),
6824 UnsizeVtable(ref a, ref b) => format!("UnsizeVtable({},{})", a.repr(tcx), b.repr(tcx)),
6829 impl<'tcx> Repr<'tcx> for AutoDerefRef<'tcx> {
6830 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6831 format!("AutoDerefRef({}, {})", self.autoderefs, self.autoref.repr(tcx))
6835 impl<'tcx> Repr<'tcx> for AutoRef<'tcx> {
6836 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6838 AutoPtr(a, b, ref c) => {
6839 format!("AutoPtr({},{:?},{})", a.repr(tcx), b, c.repr(tcx))
6841 AutoUnsize(ref a) => {
6842 format!("AutoUnsize({})", a.repr(tcx))
6844 AutoUnsizeUniq(ref a) => {
6845 format!("AutoUnsizeUniq({})", a.repr(tcx))
6847 AutoUnsafe(ref a, ref b) => {
6848 format!("AutoUnsafe({:?},{})", a, b.repr(tcx))
6854 impl<'tcx> Repr<'tcx> for TyTrait<'tcx> {
6855 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6856 format!("TyTrait({},{})",
6857 self.principal.repr(tcx),
6858 self.bounds.repr(tcx))
6862 impl<'tcx> Repr<'tcx> for ty::Predicate<'tcx> {
6863 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6865 Predicate::Trait(ref a) => a.repr(tcx),
6866 Predicate::Equate(ref pair) => pair.repr(tcx),
6867 Predicate::RegionOutlives(ref pair) => pair.repr(tcx),
6868 Predicate::TypeOutlives(ref pair) => pair.repr(tcx),
6869 Predicate::Projection(ref pair) => pair.repr(tcx),
6874 impl<'tcx> Repr<'tcx> for vtable_origin<'tcx> {
6875 fn repr(&self, tcx: &ty::ctxt<'tcx>) -> String {
6877 vtable_static(def_id, ref tys, ref vtable_res) => {
6878 format!("vtable_static({:?}:{}, {}, {})",
6880 ty::item_path_str(tcx, def_id),
6882 vtable_res.repr(tcx))
6885 vtable_param(x, y) => {
6886 format!("vtable_param({:?}, {})", x, y)
6889 vtable_unboxed_closure(def_id) => {
6890 format!("vtable_unboxed_closure({:?})", def_id)
6894 format!("vtable_error")
6900 pub fn make_substs_for_receiver_types<'tcx>(tcx: &ty::ctxt<'tcx>,
6901 trait_ref: &ty::TraitRef<'tcx>,
6902 method: &ty::Method<'tcx>)
6903 -> subst::Substs<'tcx>
6906 * Substitutes the values for the receiver's type parameters
6907 * that are found in method, leaving the method's type parameters
6911 let meth_tps: Vec<Ty> =
6912 method.generics.types.get_slice(subst::FnSpace)
6914 .map(|def| ty::mk_param_from_def(tcx, def))
6916 let meth_regions: Vec<ty::Region> =
6917 method.generics.regions.get_slice(subst::FnSpace)
6919 .map(|def| ty::ReEarlyBound(def.def_id.node, def.space,
6920 def.index, def.name))
6922 trait_ref.substs.clone().with_method(meth_tps, meth_regions)
6926 pub enum CopyImplementationError {
6927 FieldDoesNotImplementCopy(ast::Name),
6928 VariantDoesNotImplementCopy(ast::Name),
6933 pub fn can_type_implement_copy<'a,'tcx>(param_env: &ParameterEnvironment<'a, 'tcx>,
6935 self_type: Ty<'tcx>)
6936 -> Result<(),CopyImplementationError>
6938 let tcx = param_env.tcx;
6940 let did = match self_type.sty {
6941 ty::ty_struct(struct_did, substs) => {
6942 let fields = ty::struct_fields(tcx, struct_did, substs);
6943 for field in fields.iter() {
6944 if type_moves_by_default(param_env, span, field.mt.ty) {
6945 return Err(FieldDoesNotImplementCopy(field.name))
6950 ty::ty_enum(enum_did, substs) => {
6951 let enum_variants = ty::enum_variants(tcx, enum_did);
6952 for variant in enum_variants.iter() {
6953 for variant_arg_type in variant.args.iter() {
6954 let substd_arg_type =
6955 variant_arg_type.subst(tcx, substs);
6956 if type_moves_by_default(param_env, span, substd_arg_type) {
6957 return Err(VariantDoesNotImplementCopy(variant.name))
6963 _ => return Err(TypeIsStructural),
6966 if ty::has_dtor(tcx, did) {
6967 return Err(TypeHasDestructor)
6973 // FIXME(#20298) -- all of these types basically walk various
6974 // structures to test whether types/regions are reachable with various
6975 // properties. It should be possible to express them in terms of one
6976 // common "walker" trait or something.
6978 pub trait RegionEscape {
6979 fn has_escaping_regions(&self) -> bool {
6980 self.has_regions_escaping_depth(0)
6983 fn has_regions_escaping_depth(&self, depth: u32) -> bool;
6986 impl<'tcx> RegionEscape for Ty<'tcx> {
6987 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6988 ty::type_escapes_depth(*self, depth)
6992 impl<'tcx> RegionEscape for Substs<'tcx> {
6993 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6994 self.types.has_regions_escaping_depth(depth) ||
6995 self.regions.has_regions_escaping_depth(depth)
6999 impl<'tcx,T:RegionEscape> RegionEscape for VecPerParamSpace<T> {
7000 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7001 self.iter_enumerated().any(|(space, _, t)| {
7002 if space == subst::FnSpace {
7003 t.has_regions_escaping_depth(depth+1)
7005 t.has_regions_escaping_depth(depth)
7011 impl<'tcx> RegionEscape for TypeScheme<'tcx> {
7012 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7013 self.ty.has_regions_escaping_depth(depth) ||
7014 self.generics.has_regions_escaping_depth(depth)
7018 impl RegionEscape for Region {
7019 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7020 self.escapes_depth(depth)
7024 impl<'tcx> RegionEscape for Generics<'tcx> {
7025 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7026 self.predicates.has_regions_escaping_depth(depth)
7030 impl<'tcx> RegionEscape for Predicate<'tcx> {
7031 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7033 Predicate::Trait(ref data) => data.has_regions_escaping_depth(depth),
7034 Predicate::Equate(ref data) => data.has_regions_escaping_depth(depth),
7035 Predicate::RegionOutlives(ref data) => data.has_regions_escaping_depth(depth),
7036 Predicate::TypeOutlives(ref data) => data.has_regions_escaping_depth(depth),
7037 Predicate::Projection(ref data) => data.has_regions_escaping_depth(depth),
7042 impl<'tcx> RegionEscape for TraitRef<'tcx> {
7043 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7044 self.substs.types.iter().any(|t| t.has_regions_escaping_depth(depth)) ||
7045 self.substs.regions.has_regions_escaping_depth(depth)
7049 impl<'tcx> RegionEscape for subst::RegionSubsts {
7050 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7052 subst::ErasedRegions => false,
7053 subst::NonerasedRegions(ref r) => {
7054 r.iter().any(|t| t.has_regions_escaping_depth(depth))
7060 impl<'tcx,T:RegionEscape> RegionEscape for Binder<T> {
7061 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7062 self.0.has_regions_escaping_depth(depth + 1)
7066 impl<'tcx> RegionEscape for EquatePredicate<'tcx> {
7067 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7068 self.0.has_regions_escaping_depth(depth) || self.1.has_regions_escaping_depth(depth)
7072 impl<'tcx> RegionEscape for TraitPredicate<'tcx> {
7073 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7074 self.trait_ref.has_regions_escaping_depth(depth)
7078 impl<T:RegionEscape,U:RegionEscape> RegionEscape for OutlivesPredicate<T,U> {
7079 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7080 self.0.has_regions_escaping_depth(depth) || self.1.has_regions_escaping_depth(depth)
7084 impl<'tcx> RegionEscape for ProjectionPredicate<'tcx> {
7085 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7086 self.projection_ty.has_regions_escaping_depth(depth) ||
7087 self.ty.has_regions_escaping_depth(depth)
7091 impl<'tcx> RegionEscape for ProjectionTy<'tcx> {
7092 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7093 self.trait_ref.has_regions_escaping_depth(depth)
7097 impl<'tcx> Repr<'tcx> for ty::ProjectionPredicate<'tcx> {
7098 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7099 format!("ProjectionPredicate({}, {})",
7100 self.projection_ty.repr(tcx),
7105 pub trait HasProjectionTypes {
7106 fn has_projection_types(&self) -> bool;
7109 impl<'tcx,T:HasProjectionTypes> HasProjectionTypes for Vec<T> {
7110 fn has_projection_types(&self) -> bool {
7111 self.iter().any(|p| p.has_projection_types())
7115 impl<'tcx,T:HasProjectionTypes> HasProjectionTypes for VecPerParamSpace<T> {
7116 fn has_projection_types(&self) -> bool {
7117 self.iter().any(|p| p.has_projection_types())
7121 impl<'tcx> HasProjectionTypes for ClosureTy<'tcx> {
7122 fn has_projection_types(&self) -> bool {
7123 self.sig.has_projection_types()
7127 impl<'tcx> HasProjectionTypes for UnboxedClosureUpvar<'tcx> {
7128 fn has_projection_types(&self) -> bool {
7129 self.ty.has_projection_types()
7133 impl<'tcx> HasProjectionTypes for ty::GenericBounds<'tcx> {
7134 fn has_projection_types(&self) -> bool {
7135 self.predicates.has_projection_types()
7139 impl<'tcx> HasProjectionTypes for Predicate<'tcx> {
7140 fn has_projection_types(&self) -> bool {
7142 Predicate::Trait(ref data) => data.has_projection_types(),
7143 Predicate::Equate(ref data) => data.has_projection_types(),
7144 Predicate::RegionOutlives(ref data) => data.has_projection_types(),
7145 Predicate::TypeOutlives(ref data) => data.has_projection_types(),
7146 Predicate::Projection(ref data) => data.has_projection_types(),
7151 impl<'tcx> HasProjectionTypes for TraitPredicate<'tcx> {
7152 fn has_projection_types(&self) -> bool {
7153 self.trait_ref.has_projection_types()
7157 impl<'tcx> HasProjectionTypes for EquatePredicate<'tcx> {
7158 fn has_projection_types(&self) -> bool {
7159 self.0.has_projection_types() || self.1.has_projection_types()
7163 impl HasProjectionTypes for Region {
7164 fn has_projection_types(&self) -> bool {
7169 impl<T:HasProjectionTypes,U:HasProjectionTypes> HasProjectionTypes for OutlivesPredicate<T,U> {
7170 fn has_projection_types(&self) -> bool {
7171 self.0.has_projection_types() || self.1.has_projection_types()
7175 impl<'tcx> HasProjectionTypes for ProjectionPredicate<'tcx> {
7176 fn has_projection_types(&self) -> bool {
7177 self.projection_ty.has_projection_types() || self.ty.has_projection_types()
7181 impl<'tcx> HasProjectionTypes for ProjectionTy<'tcx> {
7182 fn has_projection_types(&self) -> bool {
7183 self.trait_ref.has_projection_types()
7187 impl<'tcx> HasProjectionTypes for Ty<'tcx> {
7188 fn has_projection_types(&self) -> bool {
7189 ty::type_has_projection(*self)
7193 impl<'tcx> HasProjectionTypes for TraitRef<'tcx> {
7194 fn has_projection_types(&self) -> bool {
7195 self.substs.has_projection_types()
7199 impl<'tcx> HasProjectionTypes for subst::Substs<'tcx> {
7200 fn has_projection_types(&self) -> bool {
7201 self.types.iter().any(|t| t.has_projection_types())
7205 impl<'tcx,T> HasProjectionTypes for Option<T>
7206 where T : HasProjectionTypes
7208 fn has_projection_types(&self) -> bool {
7209 self.iter().any(|t| t.has_projection_types())
7213 impl<'tcx,T> HasProjectionTypes for Rc<T>
7214 where T : HasProjectionTypes
7216 fn has_projection_types(&self) -> bool {
7217 (**self).has_projection_types()
7221 impl<'tcx,T> HasProjectionTypes for Box<T>
7222 where T : HasProjectionTypes
7224 fn has_projection_types(&self) -> bool {
7225 (**self).has_projection_types()
7229 impl<T> HasProjectionTypes for Binder<T>
7230 where T : HasProjectionTypes
7232 fn has_projection_types(&self) -> bool {
7233 self.0.has_projection_types()
7237 impl<'tcx> HasProjectionTypes for FnOutput<'tcx> {
7238 fn has_projection_types(&self) -> bool {
7240 FnConverging(t) => t.has_projection_types(),
7241 FnDiverging => false,
7246 impl<'tcx> HasProjectionTypes for FnSig<'tcx> {
7247 fn has_projection_types(&self) -> bool {
7248 self.inputs.iter().any(|t| t.has_projection_types()) ||
7249 self.output.has_projection_types()
7253 impl<'tcx> HasProjectionTypes for field<'tcx> {
7254 fn has_projection_types(&self) -> bool {
7255 self.mt.ty.has_projection_types()
7259 impl<'tcx> HasProjectionTypes for BareFnTy<'tcx> {
7260 fn has_projection_types(&self) -> bool {
7261 self.sig.has_projection_types()
7265 pub trait ReferencesError {
7266 fn references_error(&self) -> bool;
7269 impl<T:ReferencesError> ReferencesError for Binder<T> {
7270 fn references_error(&self) -> bool {
7271 self.0.references_error()
7275 impl<T:ReferencesError> ReferencesError for Rc<T> {
7276 fn references_error(&self) -> bool {
7277 (&**self).references_error()
7281 impl<'tcx> ReferencesError for TraitPredicate<'tcx> {
7282 fn references_error(&self) -> bool {
7283 self.trait_ref.references_error()
7287 impl<'tcx> ReferencesError for ProjectionPredicate<'tcx> {
7288 fn references_error(&self) -> bool {
7289 self.projection_ty.trait_ref.references_error() || self.ty.references_error()
7293 impl<'tcx> ReferencesError for TraitRef<'tcx> {
7294 fn references_error(&self) -> bool {
7295 self.input_types().iter().any(|t| t.references_error())
7299 impl<'tcx> ReferencesError for Ty<'tcx> {
7300 fn references_error(&self) -> bool {
7301 type_is_error(*self)
7305 impl<'tcx> ReferencesError for Predicate<'tcx> {
7306 fn references_error(&self) -> bool {
7308 Predicate::Trait(ref data) => data.references_error(),
7309 Predicate::Equate(ref data) => data.references_error(),
7310 Predicate::RegionOutlives(ref data) => data.references_error(),
7311 Predicate::TypeOutlives(ref data) => data.references_error(),
7312 Predicate::Projection(ref data) => data.references_error(),
7317 impl<A,B> ReferencesError for OutlivesPredicate<A,B>
7318 where A : ReferencesError, B : ReferencesError
7320 fn references_error(&self) -> bool {
7321 self.0.references_error() || self.1.references_error()
7325 impl<'tcx> ReferencesError for EquatePredicate<'tcx>
7327 fn references_error(&self) -> bool {
7328 self.0.references_error() || self.1.references_error()
7332 impl ReferencesError for Region
7334 fn references_error(&self) -> bool {
7339 impl<'tcx> Repr<'tcx> for ClosureTy<'tcx> {
7340 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7341 format!("ClosureTy({},{},{:?},{},{},{})",
7345 self.bounds.repr(tcx),
7351 impl<'tcx> Repr<'tcx> for UnboxedClosureUpvar<'tcx> {
7352 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7353 format!("UnboxedClosureUpvar({},{})",
7359 impl<'tcx> Repr<'tcx> for field<'tcx> {
7360 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7361 format!("field({},{})",
7362 self.name.repr(tcx),
7367 impl<'a, 'tcx> Repr<'tcx> for ParameterEnvironment<'a, 'tcx> {
7368 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7369 format!("ParameterEnvironment(\
7371 implicit_region_bound={}, \
7373 self.free_substs.repr(tcx),
7374 self.implicit_region_bound.repr(tcx),
7375 self.caller_bounds.repr(tcx))