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 trait onto a list of negative impls of that trait.
754 pub trait_negative_impls: RefCell<DefIdMap<Rc<RefCell<Vec<ast::DefId>>>>>,
756 /// Maps a DefId of a type to a list of its inherent impls.
757 /// Contains implementations of methods that are inherent to a type.
758 /// Methods in these implementations don't need to be exported.
759 pub inherent_impls: RefCell<DefIdMap<Rc<Vec<ast::DefId>>>>,
761 /// Maps a DefId of an impl to a list of its items.
762 /// Note that this contains all of the impls that we know about,
763 /// including ones in other crates. It's not clear that this is the best
765 pub impl_items: RefCell<DefIdMap<Vec<ImplOrTraitItemId>>>,
767 /// Set of used unsafe nodes (functions or blocks). Unsafe nodes not
768 /// present in this set can be warned about.
769 pub used_unsafe: RefCell<NodeSet>,
771 /// Set of nodes which mark locals as mutable which end up getting used at
772 /// some point. Local variable definitions not in this set can be warned
774 pub used_mut_nodes: RefCell<NodeSet>,
776 /// The set of external nominal types whose implementations have been read.
777 /// This is used for lazy resolution of methods.
778 pub populated_external_types: RefCell<DefIdSet>,
780 /// The set of external traits whose implementations have been read. This
781 /// is used for lazy resolution of traits.
782 pub populated_external_traits: RefCell<DefIdSet>,
785 pub upvar_borrow_map: RefCell<UpvarBorrowMap>,
787 /// These two caches are used by const_eval when decoding external statics
788 /// and variants that are found.
789 pub extern_const_statics: RefCell<DefIdMap<ast::NodeId>>,
790 pub extern_const_variants: RefCell<DefIdMap<ast::NodeId>>,
792 pub method_map: MethodMap<'tcx>,
794 pub dependency_formats: RefCell<dependency_format::Dependencies>,
796 /// Records the type of each unboxed closure. The def ID is the ID of the
797 /// expression defining the unboxed closure.
798 pub unboxed_closures: RefCell<DefIdMap<UnboxedClosure<'tcx>>>,
800 pub node_lint_levels: RefCell<FnvHashMap<(ast::NodeId, lint::LintId),
803 /// The types that must be asserted to be the same size for `transmute`
804 /// to be valid. We gather up these restrictions in the intrinsicck pass
805 /// and check them in trans.
806 pub transmute_restrictions: RefCell<Vec<TransmuteRestriction<'tcx>>>,
808 /// Maps any item's def-id to its stability index.
809 pub stability: RefCell<stability::Index>,
811 /// Maps closures to their capture clauses.
812 pub capture_modes: RefCell<CaptureModeMap>,
814 /// Maps def IDs to true if and only if they're associated types.
815 pub associated_types: RefCell<DefIdMap<bool>>,
817 /// Caches the results of trait selection. This cache is used
818 /// for things that do not have to do with the parameters in scope.
819 pub selection_cache: traits::SelectionCache<'tcx>,
821 /// Caches the representation hints for struct definitions.
822 pub repr_hint_cache: RefCell<DefIdMap<Rc<Vec<attr::ReprAttr>>>>,
824 /// Caches whether types are known to impl Copy. Note that type
825 /// parameters are never placed into this cache, because their
826 /// results are dependent on the parameter environment.
827 pub type_impls_copy_cache: RefCell<HashMap<Ty<'tcx>,bool>>,
829 /// Caches whether types are known to impl Sized. Note that type
830 /// parameters are never placed into this cache, because their
831 /// results are dependent on the parameter environment.
832 pub type_impls_sized_cache: RefCell<HashMap<Ty<'tcx>,bool>>,
834 /// Caches whether traits are object safe
835 pub object_safety_cache: RefCell<DefIdMap<bool>>,
838 // Flags that we track on types. These flags are propagated upwards
839 // through the type during type construction, so that we can quickly
840 // check whether the type has various kinds of types in it without
841 // recursing over the type itself.
843 flags TypeFlags: u32 {
844 const NO_TYPE_FLAGS = 0b0,
845 const HAS_PARAMS = 0b1,
846 const HAS_SELF = 0b10,
847 const HAS_TY_INFER = 0b100,
848 const HAS_RE_INFER = 0b1000,
849 const HAS_RE_LATE_BOUND = 0b10000,
850 const HAS_REGIONS = 0b100000,
851 const HAS_TY_ERR = 0b1000000,
852 const HAS_PROJECTION = 0b10000000,
853 const NEEDS_SUBST = HAS_PARAMS.bits | HAS_SELF.bits | HAS_REGIONS.bits,
857 macro_rules! sty_debug_print {
858 ($ctxt: expr, $($variant: ident),*) => {{
859 // curious inner module to allow variant names to be used as
871 pub fn go(tcx: &ty::ctxt) {
872 let mut total = DebugStat {
874 region_infer: 0, ty_infer: 0, both_infer: 0,
876 $(let mut $variant = total;)*
879 for (_, t) in tcx.interner.borrow().iter() {
880 let variant = match t.sty {
881 ty::ty_bool | ty::ty_char | ty::ty_int(..) | ty::ty_uint(..) |
882 ty::ty_float(..) | ty::ty_str => continue,
883 ty::ty_err => /* unimportant */ continue,
884 $(ty::$variant(..) => &mut $variant,)*
886 let region = t.flags.intersects(ty::HAS_RE_INFER);
887 let ty = t.flags.intersects(ty::HAS_TY_INFER);
891 if region { total.region_infer += 1; variant.region_infer += 1 }
892 if ty { total.ty_infer += 1; variant.ty_infer += 1 }
893 if region && ty { total.both_infer += 1; variant.both_infer += 1 }
895 println!("Ty interner total ty region both");
896 $(println!(" {:18}: {uses:6} {usespc:4.1}%, \
897 {ty:4.1}% {region:5.1}% {both:4.1}%",
898 stringify!($variant),
899 uses = $variant.total,
900 usespc = $variant.total as f64 * 100.0 / total.total as f64,
901 ty = $variant.ty_infer as f64 * 100.0 / total.total as f64,
902 region = $variant.region_infer as f64 * 100.0 / total.total as f64,
903 both = $variant.both_infer as f64 * 100.0 / total.total as f64);
905 println!(" total {uses:6} \
906 {ty:4.1}% {region:5.1}% {both:4.1}%",
908 ty = total.ty_infer as f64 * 100.0 / total.total as f64,
909 region = total.region_infer as f64 * 100.0 / total.total as f64,
910 both = total.both_infer as f64 * 100.0 / total.total as f64)
918 impl<'tcx> ctxt<'tcx> {
919 pub fn print_debug_stats(&self) {
922 ty_enum, ty_uniq, ty_vec, ty_ptr, ty_rptr, ty_bare_fn, ty_trait,
923 ty_struct, ty_unboxed_closure, ty_tup, ty_param, ty_open, ty_infer, ty_projection);
925 println!("Substs interner: #{}", self.substs_interner.borrow().len());
926 println!("BareFnTy interner: #{}", self.bare_fn_interner.borrow().len());
927 println!("Region interner: #{}", self.region_interner.borrow().len());
932 pub struct TyS<'tcx> {
934 pub flags: TypeFlags,
936 // the maximal depth of any bound regions appearing in this type.
940 impl fmt::Show for TypeFlags {
941 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
942 write!(f, "{}", self.bits)
946 impl<'tcx> PartialEq for TyS<'tcx> {
947 fn eq(&self, other: &TyS<'tcx>) -> bool {
948 (self as *const _) == (other as *const _)
951 impl<'tcx> Eq for TyS<'tcx> {}
954 impl<'tcx, S: Writer> Hash<S> for TyS<'tcx> {
955 fn hash(&self, s: &mut S) {
956 (self as *const _).hash(s)
960 impl<'tcx, S: Writer + Hasher> Hash<S> for TyS<'tcx> {
961 fn hash(&self, s: &mut S) {
962 (self as *const _).hash(s)
966 pub type Ty<'tcx> = &'tcx TyS<'tcx>;
968 /// An entry in the type interner.
969 pub struct InternedTy<'tcx> {
973 // NB: An InternedTy compares and hashes as a sty.
974 impl<'tcx> PartialEq for InternedTy<'tcx> {
975 fn eq(&self, other: &InternedTy<'tcx>) -> bool {
976 self.ty.sty == other.ty.sty
980 impl<'tcx> Eq for InternedTy<'tcx> {}
982 impl<'tcx, S: Writer + Hasher> Hash<S> for InternedTy<'tcx> {
983 fn hash(&self, s: &mut S) {
988 impl<'tcx> BorrowFrom<InternedTy<'tcx>> for sty<'tcx> {
989 fn borrow_from<'a>(ty: &'a InternedTy<'tcx>) -> &'a sty<'tcx> {
994 pub fn type_has_params(ty: Ty) -> bool {
995 ty.flags.intersects(HAS_PARAMS)
997 pub fn type_has_self(ty: Ty) -> bool {
998 ty.flags.intersects(HAS_SELF)
1000 pub fn type_has_ty_infer(ty: Ty) -> bool {
1001 ty.flags.intersects(HAS_TY_INFER)
1003 pub fn type_needs_infer(ty: Ty) -> bool {
1004 ty.flags.intersects(HAS_TY_INFER | HAS_RE_INFER)
1006 pub fn type_has_projection(ty: Ty) -> bool {
1007 ty.flags.intersects(HAS_PROJECTION)
1010 pub fn type_has_late_bound_regions(ty: Ty) -> bool {
1011 ty.flags.intersects(HAS_RE_LATE_BOUND)
1014 /// An "escaping region" is a bound region whose binder is not part of `t`.
1016 /// So, for example, consider a type like the following, which has two binders:
1018 /// for<'a> fn(x: for<'b> fn(&'a int, &'b int))
1019 /// ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ outer scope
1020 /// ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ inner scope
1022 /// This type has *bound regions* (`'a`, `'b`), but it does not have escaping regions, because the
1023 /// binders of both `'a` and `'b` are part of the type itself. However, if we consider the *inner
1024 /// fn type*, that type has an escaping region: `'a`.
1026 /// Note that what I'm calling an "escaping region" is often just called a "free region". However,
1027 /// we already use the term "free region". It refers to the regions that we use to represent bound
1028 /// regions on a fn definition while we are typechecking its body.
1030 /// To clarify, conceptually there is no particular difference between an "escaping" region and a
1031 /// "free" region. However, there is a big difference in practice. Basically, when "entering" a
1032 /// binding level, one is generally required to do some sort of processing to a bound region, such
1033 /// as replacing it with a fresh/skolemized region, or making an entry in the environment to
1034 /// represent the scope to which it is attached, etc. An escaping region represents a bound region
1035 /// for which this processing has not yet been done.
1036 pub fn type_has_escaping_regions(ty: Ty) -> bool {
1037 type_escapes_depth(ty, 0)
1040 pub fn type_escapes_depth(ty: Ty, depth: u32) -> bool {
1041 ty.region_depth > depth
1044 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1045 pub struct BareFnTy<'tcx> {
1046 pub unsafety: ast::Unsafety,
1048 pub sig: PolyFnSig<'tcx>,
1051 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1052 pub struct ClosureTy<'tcx> {
1053 pub unsafety: ast::Unsafety,
1054 pub onceness: ast::Onceness,
1055 pub store: TraitStore,
1056 pub bounds: ExistentialBounds<'tcx>,
1057 pub sig: PolyFnSig<'tcx>,
1061 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
1062 pub enum FnOutput<'tcx> {
1063 FnConverging(Ty<'tcx>),
1067 impl<'tcx> FnOutput<'tcx> {
1068 pub fn diverges(&self) -> bool {
1069 *self == FnDiverging
1072 pub fn unwrap(self) -> Ty<'tcx> {
1074 ty::FnConverging(t) => t,
1075 ty::FnDiverging => unreachable!()
1080 pub type PolyFnOutput<'tcx> = Binder<FnOutput<'tcx>>;
1082 impl<'tcx> PolyFnOutput<'tcx> {
1083 pub fn diverges(&self) -> bool {
1088 /// Signature of a function type, which I have arbitrarily
1089 /// decided to use to refer to the input/output types.
1091 /// - `inputs` is the list of arguments and their modes.
1092 /// - `output` is the return type.
1093 /// - `variadic` indicates whether this is a variadic function. (only true for foreign fns)
1094 #[derive(Clone, PartialEq, Eq, Hash)]
1095 pub struct FnSig<'tcx> {
1096 pub inputs: Vec<Ty<'tcx>>,
1097 pub output: FnOutput<'tcx>,
1101 pub type PolyFnSig<'tcx> = Binder<FnSig<'tcx>>;
1103 impl<'tcx> PolyFnSig<'tcx> {
1104 pub fn inputs(&self) -> ty::Binder<Vec<Ty<'tcx>>> {
1105 ty::Binder(self.0.inputs.clone())
1107 pub fn input(&self, index: uint) -> ty::Binder<Ty<'tcx>> {
1108 ty::Binder(self.0.inputs[index])
1110 pub fn output(&self) -> ty::Binder<FnOutput<'tcx>> {
1111 ty::Binder(self.0.output.clone())
1113 pub fn variadic(&self) -> bool {
1118 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
1119 pub struct ParamTy {
1120 pub space: subst::ParamSpace,
1122 pub name: ast::Name,
1125 /// A [De Bruijn index][dbi] is a standard means of representing
1126 /// regions (and perhaps later types) in a higher-ranked setting. In
1127 /// particular, imagine a type like this:
1129 /// for<'a> fn(for<'b> fn(&'b int, &'a int), &'a char)
1132 /// | +------------+ 1 | |
1134 /// +--------------------------------+ 2 |
1136 /// +------------------------------------------+ 1
1138 /// In this type, there are two binders (the outer fn and the inner
1139 /// fn). We need to be able to determine, for any given region, which
1140 /// fn type it is bound by, the inner or the outer one. There are
1141 /// various ways you can do this, but a De Bruijn index is one of the
1142 /// more convenient and has some nice properties. The basic idea is to
1143 /// count the number of binders, inside out. Some examples should help
1144 /// clarify what I mean.
1146 /// Let's start with the reference type `&'b int` that is the first
1147 /// argument to the inner function. This region `'b` is assigned a De
1148 /// Bruijn index of 1, meaning "the innermost binder" (in this case, a
1149 /// fn). The region `'a` that appears in the second argument type (`&'a
1150 /// int`) would then be assigned a De Bruijn index of 2, meaning "the
1151 /// second-innermost binder". (These indices are written on the arrays
1152 /// in the diagram).
1154 /// What is interesting is that De Bruijn index attached to a particular
1155 /// variable will vary depending on where it appears. For example,
1156 /// the final type `&'a char` also refers to the region `'a` declared on
1157 /// the outermost fn. But this time, this reference is not nested within
1158 /// any other binders (i.e., it is not an argument to the inner fn, but
1159 /// rather the outer one). Therefore, in this case, it is assigned a
1160 /// De Bruijn index of 1, because the innermost binder in that location
1161 /// is the outer fn.
1163 /// [dbi]: http://en.wikipedia.org/wiki/De_Bruijn_index
1164 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Show, Copy)]
1165 pub struct DebruijnIndex {
1166 // We maintain the invariant that this is never 0. So 1 indicates
1167 // the innermost binder. To ensure this, create with `DebruijnIndex::new`.
1171 /// Representation of regions:
1172 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Show, Copy)]
1174 // Region bound in a type or fn declaration which will be
1175 // substituted 'early' -- that is, at the same time when type
1176 // parameters are substituted.
1177 ReEarlyBound(/* param id */ ast::NodeId,
1182 // Region bound in a function scope, which will be substituted when the
1183 // function is called.
1184 ReLateBound(DebruijnIndex, BoundRegion),
1186 /// When checking a function body, the types of all arguments and so forth
1187 /// that refer to bound region parameters are modified to refer to free
1188 /// region parameters.
1191 /// A concrete region naming some expression within the current function.
1192 ReScope(region::CodeExtent),
1194 /// Static data that has an "infinite" lifetime. Top in the region lattice.
1197 /// A region variable. Should not exist after typeck.
1198 ReInfer(InferRegion),
1200 /// Empty lifetime is for data that is never accessed.
1201 /// Bottom in the region lattice. We treat ReEmpty somewhat
1202 /// specially; at least right now, we do not generate instances of
1203 /// it during the GLB computations, but rather
1204 /// generate an error instead. This is to improve error messages.
1205 /// The only way to get an instance of ReEmpty is to have a region
1206 /// variable with no constraints.
1210 /// Upvars do not get their own node-id. Instead, we use the pair of
1211 /// the original var id (that is, the root variable that is referenced
1212 /// by the upvar) and the id of the closure expression.
1213 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
1214 pub struct UpvarId {
1215 pub var_id: ast::NodeId,
1216 pub closure_expr_id: ast::NodeId,
1219 #[derive(Clone, PartialEq, Eq, Hash, Show, RustcEncodable, RustcDecodable, Copy)]
1220 pub enum BorrowKind {
1221 /// Data must be immutable and is aliasable.
1224 /// Data must be immutable but not aliasable. This kind of borrow
1225 /// cannot currently be expressed by the user and is used only in
1226 /// implicit closure bindings. It is needed when you the closure
1227 /// is borrowing or mutating a mutable referent, e.g.:
1229 /// let x: &mut int = ...;
1230 /// let y = || *x += 5;
1232 /// If we were to try to translate this closure into a more explicit
1233 /// form, we'd encounter an error with the code as written:
1235 /// struct Env { x: & &mut int }
1236 /// let x: &mut int = ...;
1237 /// let y = (&mut Env { &x }, fn_ptr); // Closure is pair of env and fn
1238 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
1240 /// This is then illegal because you cannot mutate a `&mut` found
1241 /// in an aliasable location. To solve, you'd have to translate with
1242 /// an `&mut` borrow:
1244 /// struct Env { x: & &mut int }
1245 /// let x: &mut int = ...;
1246 /// let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x
1247 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
1249 /// Now the assignment to `**env.x` is legal, but creating a
1250 /// mutable pointer to `x` is not because `x` is not mutable. We
1251 /// could fix this by declaring `x` as `let mut x`. This is ok in
1252 /// user code, if awkward, but extra weird for closures, since the
1253 /// borrow is hidden.
1255 /// So we introduce a "unique imm" borrow -- the referent is
1256 /// immutable, but not aliasable. This solves the problem. For
1257 /// simplicity, we don't give users the way to express this
1258 /// borrow, it's just used when translating closures.
1261 /// Data is mutable and not aliasable.
1265 /// Information describing the borrowing of an upvar. This is computed
1266 /// during `typeck`, specifically by `regionck`. The general idea is
1267 /// that the compiler analyses treat closures like:
1269 /// let closure: &'e fn() = || {
1270 /// x = 1; // upvar x is assigned to
1271 /// use(y); // upvar y is read
1272 /// foo(&z); // upvar z is borrowed immutably
1275 /// as if they were "desugared" to something loosely like:
1277 /// struct Vars<'x,'y,'z> { x: &'x mut int,
1278 /// y: &'y const int,
1280 /// let closure: &'e fn() = {
1281 /// fn f(env: &Vars) {
1286 /// let env: &'e mut Vars<'x,'y,'z> = &mut Vars { x: &'x mut x,
1292 /// This is basically what happens at runtime. The closure is basically
1293 /// an existentially quantified version of the `(env, f)` pair.
1295 /// This data structure indicates the region and mutability of a single
1296 /// one of the `x...z` borrows.
1298 /// It may not be obvious why each borrowed variable gets its own
1299 /// lifetime (in the desugared version of the example, these are indicated
1300 /// by the lifetime parameters `'x`, `'y`, and `'z` in the `Vars` definition).
1301 /// Each such lifetime must encompass the lifetime `'e` of the closure itself,
1302 /// but need not be identical to it. The reason that this makes sense:
1304 /// - Callers are only permitted to invoke the closure, and hence to
1305 /// use the pointers, within the lifetime `'e`, so clearly `'e` must
1306 /// be a sublifetime of `'x...'z`.
1307 /// - The closure creator knows which upvars were borrowed by the closure
1308 /// and thus `x...z` will be reserved for `'x...'z` respectively.
1309 /// - Through mutation, the borrowed upvars can actually escape
1310 /// the closure, so sometimes it is necessary for them to be larger
1311 /// than the closure lifetime itself.
1312 #[derive(PartialEq, Clone, RustcEncodable, RustcDecodable, Show, Copy)]
1313 pub struct UpvarBorrow {
1314 pub kind: BorrowKind,
1315 pub region: ty::Region,
1318 pub type UpvarBorrowMap = FnvHashMap<UpvarId, UpvarBorrow>;
1321 pub fn is_bound(&self) -> bool {
1323 ty::ReEarlyBound(..) => true,
1324 ty::ReLateBound(..) => true,
1329 pub fn escapes_depth(&self, depth: u32) -> bool {
1331 ty::ReLateBound(debruijn, _) => debruijn.depth > depth,
1337 #[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
1338 RustcEncodable, RustcDecodable, Show, Copy)]
1339 /// A "free" region `fr` can be interpreted as "some region
1340 /// at least as big as the scope `fr.scope`".
1341 pub struct FreeRegion {
1342 pub scope: region::CodeExtent,
1343 pub bound_region: BoundRegion
1346 #[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
1347 RustcEncodable, RustcDecodable, Show, Copy)]
1348 pub enum BoundRegion {
1349 /// An anonymous region parameter for a given fn (&T)
1352 /// Named region parameters for functions (a in &'a T)
1354 /// The def-id is needed to distinguish free regions in
1355 /// the event of shadowing.
1356 BrNamed(ast::DefId, ast::Name),
1358 /// Fresh bound identifiers created during GLB computations.
1361 // Anonymous region for the implicit env pointer parameter
1366 // NB: If you change this, you'll probably want to change the corresponding
1367 // AST structure in libsyntax/ast.rs as well.
1368 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1369 pub enum sty<'tcx> {
1373 ty_uint(ast::UintTy),
1374 ty_float(ast::FloatTy),
1375 /// Substs here, possibly against intuition, *may* contain `ty_param`s.
1376 /// That is, even after substitution it is possible that there are type
1377 /// variables. This happens when the `ty_enum` corresponds to an enum
1378 /// definition and not a concrete use of it. To get the correct `ty_enum`
1379 /// from the tcx, use the `NodeId` from the `ast::Ty` and look it up in
1380 /// the `ast_ty_to_ty_cache`. This is probably true for `ty_struct` as
1382 ty_enum(DefId, &'tcx Substs<'tcx>),
1385 ty_vec(Ty<'tcx>, Option<uint>), // Second field is length.
1387 ty_rptr(&'tcx Region, mt<'tcx>),
1389 // If the def-id is Some(_), then this is the type of a specific
1390 // fn item. Otherwise, if None(_), it a fn pointer type.
1391 ty_bare_fn(Option<DefId>, &'tcx BareFnTy<'tcx>),
1393 ty_trait(Box<TyTrait<'tcx>>),
1394 ty_struct(DefId, &'tcx Substs<'tcx>),
1396 ty_unboxed_closure(DefId, &'tcx Region, &'tcx Substs<'tcx>),
1398 ty_tup(Vec<Ty<'tcx>>),
1400 ty_projection(ProjectionTy<'tcx>),
1401 ty_param(ParamTy), // type parameter
1403 ty_open(Ty<'tcx>), // A deref'ed fat pointer, i.e., a dynamically sized value
1404 // and its size. Only ever used in trans. It is not necessary
1405 // earlier since we don't need to distinguish a DST with its
1406 // size (e.g., in a deref) vs a DST with the size elsewhere (
1407 // e.g., in a field).
1409 ty_infer(InferTy), // something used only during inference/typeck
1410 ty_err, // Also only used during inference/typeck, to represent
1411 // the type of an erroneous expression (helps cut down
1412 // on non-useful type error messages)
1415 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1416 pub struct TyTrait<'tcx> {
1417 pub principal: ty::PolyTraitRef<'tcx>,
1418 pub bounds: ExistentialBounds<'tcx>,
1421 impl<'tcx> TyTrait<'tcx> {
1422 pub fn principal_def_id(&self) -> ast::DefId {
1423 self.principal.0.def_id
1426 /// Object types don't have a self-type specified. Therefore, when
1427 /// we convert the principal trait-ref into a normal trait-ref,
1428 /// you must give *some* self-type. A common choice is `mk_err()`
1429 /// or some skolemized type.
1430 pub fn principal_trait_ref_with_self_ty(&self,
1433 -> ty::PolyTraitRef<'tcx>
1435 // otherwise the escaping regions would be captured by the binder
1436 assert!(!self_ty.has_escaping_regions());
1438 ty::Binder(Rc::new(ty::TraitRef {
1439 def_id: self.principal.0.def_id,
1440 substs: tcx.mk_substs(self.principal.0.substs.with_self_ty(self_ty)),
1444 pub fn projection_bounds_with_self_ty(&self,
1447 -> Vec<ty::PolyProjectionPredicate<'tcx>>
1449 // otherwise the escaping regions would be captured by the binders
1450 assert!(!self_ty.has_escaping_regions());
1452 self.bounds.projection_bounds.iter()
1453 .map(|in_poly_projection_predicate| {
1454 let in_projection_ty = &in_poly_projection_predicate.0.projection_ty;
1455 let substs = tcx.mk_substs(in_projection_ty.trait_ref.substs.with_self_ty(self_ty));
1457 Rc::new(ty::TraitRef::new(in_projection_ty.trait_ref.def_id,
1459 let projection_ty = ty::ProjectionTy {
1460 trait_ref: trait_ref,
1461 item_name: in_projection_ty.item_name
1463 ty::Binder(ty::ProjectionPredicate {
1464 projection_ty: projection_ty,
1465 ty: in_poly_projection_predicate.0.ty
1472 /// A complete reference to a trait. These take numerous guises in syntax,
1473 /// but perhaps the most recognizable form is in a where clause:
1477 /// This would be represented by a trait-reference where the def-id is the
1478 /// def-id for the trait `Foo` and the substs defines `T` as parameter 0 in the
1479 /// `SelfSpace` and `U` as parameter 0 in the `TypeSpace`.
1481 /// Trait references also appear in object types like `Foo<U>`, but in
1482 /// that case the `Self` parameter is absent from the substitutions.
1484 /// Note that a `TraitRef` introduces a level of region binding, to
1485 /// account for higher-ranked trait bounds like `T : for<'a> Foo<&'a
1486 /// U>` or higher-ranked object types.
1487 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1488 pub struct TraitRef<'tcx> {
1490 pub substs: &'tcx Substs<'tcx>,
1493 pub type PolyTraitRef<'tcx> = Binder<Rc<TraitRef<'tcx>>>;
1495 impl<'tcx> PolyTraitRef<'tcx> {
1496 pub fn self_ty(&self) -> Ty<'tcx> {
1500 pub fn def_id(&self) -> ast::DefId {
1504 pub fn substs(&self) -> &'tcx Substs<'tcx> {
1505 // FIXME(#20664) every use of this fn is probably a bug, it should yield Binder<>
1509 pub fn input_types(&self) -> &[Ty<'tcx>] {
1510 // FIXME(#20664) every use of this fn is probably a bug, it should yield Binder<>
1511 self.0.input_types()
1514 pub fn to_poly_trait_predicate(&self) -> PolyTraitPredicate<'tcx> {
1515 // Note that we preserve binding levels
1516 Binder(TraitPredicate { trait_ref: self.0.clone() })
1520 /// Binder is a binder for higher-ranked lifetimes. It is part of the
1521 /// compiler's representation for things like `for<'a> Fn(&'a int)`
1522 /// (which would be represented by the type `PolyTraitRef ==
1523 /// Binder<TraitRef>`). Note that when we skolemize, instantiate,
1524 /// erase, or otherwise "discharge" these bound reons, we change the
1525 /// type from `Binder<T>` to just `T` (see
1526 /// e.g. `liberate_late_bound_regions`).
1527 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1528 pub struct Binder<T>(pub T);
1530 #[derive(Clone, Copy, PartialEq)]
1531 pub enum IntVarValue {
1532 IntType(ast::IntTy),
1533 UintType(ast::UintTy),
1536 #[derive(Clone, Copy, Show)]
1537 pub enum terr_vstore_kind {
1544 #[derive(Clone, Copy, Show)]
1545 pub struct expected_found<T> {
1550 // Data structures used in type unification
1551 #[derive(Clone, Copy, Show)]
1552 pub enum type_err<'tcx> {
1554 terr_unsafety_mismatch(expected_found<ast::Unsafety>),
1555 terr_onceness_mismatch(expected_found<Onceness>),
1556 terr_abi_mismatch(expected_found<abi::Abi>),
1558 terr_sigil_mismatch(expected_found<TraitStore>),
1559 terr_box_mutability,
1560 terr_ptr_mutability,
1561 terr_ref_mutability,
1562 terr_vec_mutability,
1563 terr_tuple_size(expected_found<uint>),
1564 terr_fixed_array_size(expected_found<uint>),
1565 terr_ty_param_size(expected_found<uint>),
1567 terr_regions_does_not_outlive(Region, Region),
1568 terr_regions_not_same(Region, Region),
1569 terr_regions_no_overlap(Region, Region),
1570 terr_regions_insufficiently_polymorphic(BoundRegion, Region),
1571 terr_regions_overly_polymorphic(BoundRegion, Region),
1572 terr_trait_stores_differ(terr_vstore_kind, expected_found<TraitStore>),
1573 terr_sorts(expected_found<Ty<'tcx>>),
1574 terr_integer_as_char,
1575 terr_int_mismatch(expected_found<IntVarValue>),
1576 terr_float_mismatch(expected_found<ast::FloatTy>),
1577 terr_traits(expected_found<ast::DefId>),
1578 terr_builtin_bounds(expected_found<BuiltinBounds>),
1579 terr_variadic_mismatch(expected_found<bool>),
1581 terr_convergence_mismatch(expected_found<bool>),
1582 terr_projection_name_mismatched(expected_found<ast::Name>),
1583 terr_projection_bounds_length(expected_found<uint>),
1586 /// Bounds suitable for a named type parameter like `A` in `fn foo<A>`
1587 /// as well as the existential type parameter in an object type.
1588 #[derive(PartialEq, Eq, Hash, Clone, Show)]
1589 pub struct ParamBounds<'tcx> {
1590 pub region_bounds: Vec<ty::Region>,
1591 pub builtin_bounds: BuiltinBounds,
1592 pub trait_bounds: Vec<PolyTraitRef<'tcx>>,
1593 pub projection_bounds: Vec<PolyProjectionPredicate<'tcx>>,
1596 /// Bounds suitable for an existentially quantified type parameter
1597 /// such as those that appear in object types or closure types. The
1598 /// major difference between this case and `ParamBounds` is that
1599 /// general purpose trait bounds are omitted and there must be
1600 /// *exactly one* region.
1601 #[derive(PartialEq, Eq, Hash, Clone, Show)]
1602 pub struct ExistentialBounds<'tcx> {
1603 pub region_bound: ty::Region,
1604 pub builtin_bounds: BuiltinBounds,
1605 pub projection_bounds: Vec<PolyProjectionPredicate<'tcx>>,
1608 pub type BuiltinBounds = EnumSet<BuiltinBound>;
1610 #[derive(Clone, RustcEncodable, PartialEq, Eq, RustcDecodable, Hash,
1613 pub enum BuiltinBound {
1620 pub fn empty_builtin_bounds() -> BuiltinBounds {
1624 pub fn all_builtin_bounds() -> BuiltinBounds {
1625 let mut set = EnumSet::new();
1626 set.insert(BoundSend);
1627 set.insert(BoundSized);
1628 set.insert(BoundSync);
1632 /// An existential bound that does not implement any traits.
1633 pub fn region_existential_bound<'tcx>(r: ty::Region) -> ExistentialBounds<'tcx> {
1634 ty::ExistentialBounds { region_bound: r,
1635 builtin_bounds: empty_builtin_bounds(),
1636 projection_bounds: Vec::new() }
1639 impl CLike for BuiltinBound {
1640 fn to_uint(&self) -> uint {
1643 fn from_uint(v: uint) -> BuiltinBound {
1644 unsafe { mem::transmute(v) }
1648 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1653 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1658 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1659 pub struct FloatVid {
1663 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
1664 pub struct RegionVid {
1668 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1674 /// A `FreshTy` is one that is generated as a replacement for an
1675 /// unbound type variable. This is convenient for caching etc. See
1676 /// `middle::infer::freshen` for more details.
1679 // FIXME -- once integral fallback is impl'd, we should remove
1680 // this type. It's only needed to prevent spurious errors for
1681 // integers whose type winds up never being constrained.
1685 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Show, Copy)]
1686 pub enum UnconstrainedNumeric {
1693 #[derive(Clone, RustcEncodable, RustcDecodable, Eq, Hash, Show, Copy)]
1694 pub enum InferRegion {
1696 ReSkolemized(u32, BoundRegion)
1699 impl cmp::PartialEq for InferRegion {
1700 fn eq(&self, other: &InferRegion) -> bool {
1701 match ((*self), *other) {
1702 (ReVar(rva), ReVar(rvb)) => {
1705 (ReSkolemized(rva, _), ReSkolemized(rvb, _)) => {
1711 fn ne(&self, other: &InferRegion) -> bool {
1712 !((*self) == (*other))
1716 impl fmt::Show for TyVid {
1717 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result{
1718 write!(f, "_#{}t", self.index)
1722 impl fmt::Show for IntVid {
1723 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1724 write!(f, "_#{}i", self.index)
1728 impl fmt::Show for FloatVid {
1729 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1730 write!(f, "_#{}f", self.index)
1734 impl fmt::Show for RegionVid {
1735 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1736 write!(f, "'_#{}r", self.index)
1740 impl<'tcx> fmt::Show for FnSig<'tcx> {
1741 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1742 write!(f, "({:?}; variadic: {})->{:?}", self.inputs, self.variadic, self.output)
1746 impl fmt::Show for InferTy {
1747 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1749 TyVar(ref v) => v.fmt(f),
1750 IntVar(ref v) => v.fmt(f),
1751 FloatVar(ref v) => v.fmt(f),
1752 FreshTy(v) => write!(f, "FreshTy({:?})", v),
1753 FreshIntTy(v) => write!(f, "FreshIntTy({:?})", v),
1758 impl fmt::Show for IntVarValue {
1759 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1761 IntType(ref v) => v.fmt(f),
1762 UintType(ref v) => v.fmt(f),
1767 #[derive(Clone, Show)]
1768 pub struct TypeParameterDef<'tcx> {
1769 pub name: ast::Name,
1770 pub def_id: ast::DefId,
1771 pub space: subst::ParamSpace,
1773 pub bounds: ParamBounds<'tcx>,
1774 pub default: Option<Ty<'tcx>>,
1777 #[derive(RustcEncodable, RustcDecodable, Clone, Show)]
1778 pub struct RegionParameterDef {
1779 pub name: ast::Name,
1780 pub def_id: ast::DefId,
1781 pub space: subst::ParamSpace,
1783 pub bounds: Vec<ty::Region>,
1786 impl RegionParameterDef {
1787 pub fn to_early_bound_region(&self) -> ty::Region {
1788 ty::ReEarlyBound(self.def_id.node, self.space, self.index, self.name)
1792 /// Information about the formal type/lifetime parameters associated
1793 /// with an item or method. Analogous to ast::Generics.
1794 #[derive(Clone, Show)]
1795 pub struct Generics<'tcx> {
1796 pub types: VecPerParamSpace<TypeParameterDef<'tcx>>,
1797 pub regions: VecPerParamSpace<RegionParameterDef>,
1798 pub predicates: VecPerParamSpace<Predicate<'tcx>>,
1801 impl<'tcx> Generics<'tcx> {
1802 pub fn empty() -> Generics<'tcx> {
1804 types: VecPerParamSpace::empty(),
1805 regions: VecPerParamSpace::empty(),
1806 predicates: VecPerParamSpace::empty(),
1810 pub fn has_type_params(&self, space: subst::ParamSpace) -> bool {
1811 !self.types.is_empty_in(space)
1814 pub fn has_region_params(&self, space: subst::ParamSpace) -> bool {
1815 !self.regions.is_empty_in(space)
1818 pub fn is_empty(&self) -> bool {
1819 self.types.is_empty() && self.regions.is_empty()
1822 pub fn to_bounds(&self, tcx: &ty::ctxt<'tcx>, substs: &Substs<'tcx>)
1823 -> GenericBounds<'tcx> {
1825 predicates: self.predicates.subst(tcx, substs),
1830 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1831 pub enum Predicate<'tcx> {
1832 /// Corresponds to `where Foo : Bar<A,B,C>`. `Foo` here would be
1833 /// the `Self` type of the trait reference and `A`, `B`, and `C`
1834 /// would be the parameters in the `TypeSpace`.
1835 Trait(PolyTraitPredicate<'tcx>),
1837 /// where `T1 == T2`.
1838 Equate(PolyEquatePredicate<'tcx>),
1841 RegionOutlives(PolyRegionOutlivesPredicate),
1844 TypeOutlives(PolyTypeOutlivesPredicate<'tcx>),
1846 /// where <T as TraitRef>::Name == X, approximately.
1847 /// See `ProjectionPredicate` struct for details.
1848 Projection(PolyProjectionPredicate<'tcx>),
1851 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1852 pub struct TraitPredicate<'tcx> {
1853 pub trait_ref: Rc<TraitRef<'tcx>>
1855 pub type PolyTraitPredicate<'tcx> = ty::Binder<TraitPredicate<'tcx>>;
1857 impl<'tcx> TraitPredicate<'tcx> {
1858 pub fn def_id(&self) -> ast::DefId {
1859 self.trait_ref.def_id
1862 pub fn input_types(&self) -> &[Ty<'tcx>] {
1863 self.trait_ref.substs.types.as_slice()
1866 pub fn self_ty(&self) -> Ty<'tcx> {
1867 self.trait_ref.self_ty()
1871 impl<'tcx> PolyTraitPredicate<'tcx> {
1872 pub fn def_id(&self) -> ast::DefId {
1877 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1878 pub struct EquatePredicate<'tcx>(pub Ty<'tcx>, pub Ty<'tcx>); // `0 == 1`
1879 pub type PolyEquatePredicate<'tcx> = ty::Binder<EquatePredicate<'tcx>>;
1881 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1882 pub struct OutlivesPredicate<A,B>(pub A, pub B); // `A : B`
1883 pub type PolyOutlivesPredicate<A,B> = ty::Binder<OutlivesPredicate<A,B>>;
1884 pub type PolyRegionOutlivesPredicate = PolyOutlivesPredicate<ty::Region, ty::Region>;
1885 pub type PolyTypeOutlivesPredicate<'tcx> = PolyOutlivesPredicate<Ty<'tcx>, ty::Region>;
1887 /// This kind of predicate has no *direct* correspondent in the
1888 /// syntax, but it roughly corresponds to the syntactic forms:
1890 /// 1. `T : TraitRef<..., Item=Type>`
1891 /// 2. `<T as TraitRef<...>>::Item == Type` (NYI)
1893 /// In particular, form #1 is "desugared" to the combination of a
1894 /// normal trait predicate (`T : TraitRef<...>`) and one of these
1895 /// predicates. Form #2 is a broader form in that it also permits
1896 /// equality between arbitrary types. Processing an instance of Form
1897 /// \#2 eventually yields one of these `ProjectionPredicate`
1898 /// instances to normalize the LHS.
1899 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1900 pub struct ProjectionPredicate<'tcx> {
1901 pub projection_ty: ProjectionTy<'tcx>,
1905 pub type PolyProjectionPredicate<'tcx> = Binder<ProjectionPredicate<'tcx>>;
1907 impl<'tcx> PolyProjectionPredicate<'tcx> {
1908 pub fn item_name(&self) -> ast::Name {
1909 self.0.projection_ty.item_name // safe to skip the binder to access a name
1912 pub fn sort_key(&self) -> (ast::DefId, ast::Name) {
1913 self.0.projection_ty.sort_key()
1917 /// Represents the projection of an associated type. In explicit UFCS
1918 /// form this would be written `<T as Trait<..>>::N`.
1919 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1920 pub struct ProjectionTy<'tcx> {
1921 /// The trait reference `T as Trait<..>`.
1922 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
1924 /// The name `N` of the associated type.
1925 pub item_name: ast::Name,
1928 impl<'tcx> ProjectionTy<'tcx> {
1929 pub fn sort_key(&self) -> (ast::DefId, ast::Name) {
1930 (self.trait_ref.def_id, self.item_name)
1934 pub trait ToPolyTraitRef<'tcx> {
1935 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx>;
1938 impl<'tcx> ToPolyTraitRef<'tcx> for Rc<TraitRef<'tcx>> {
1939 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1940 assert!(!self.has_escaping_regions());
1941 ty::Binder(self.clone())
1945 impl<'tcx> ToPolyTraitRef<'tcx> for PolyTraitPredicate<'tcx> {
1946 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1947 // We are just preserving the binder levels here
1948 ty::Binder(self.0.trait_ref.clone())
1952 impl<'tcx> ToPolyTraitRef<'tcx> for PolyProjectionPredicate<'tcx> {
1953 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1954 // Note: unlike with TraitRef::to_poly_trait_ref(),
1955 // self.0.trait_ref is permitted to have escaping regions.
1956 // This is because here `self` has a `Binder` and so does our
1957 // return value, so we are preserving the number of binding
1959 ty::Binder(self.0.projection_ty.trait_ref.clone())
1963 pub trait AsPredicate<'tcx> {
1964 fn as_predicate(&self) -> Predicate<'tcx>;
1967 impl<'tcx> AsPredicate<'tcx> for Rc<TraitRef<'tcx>> {
1968 fn as_predicate(&self) -> Predicate<'tcx> {
1969 // we're about to add a binder, so let's check that we don't
1970 // accidentally capture anything, or else that might be some
1971 // weird debruijn accounting.
1972 assert!(!self.has_escaping_regions());
1974 ty::Predicate::Trait(ty::Binder(ty::TraitPredicate {
1975 trait_ref: self.clone()
1980 impl<'tcx> AsPredicate<'tcx> for PolyTraitRef<'tcx> {
1981 fn as_predicate(&self) -> Predicate<'tcx> {
1982 ty::Predicate::Trait(self.to_poly_trait_predicate())
1986 impl<'tcx> AsPredicate<'tcx> for PolyEquatePredicate<'tcx> {
1987 fn as_predicate(&self) -> Predicate<'tcx> {
1988 Predicate::Equate(self.clone())
1992 impl<'tcx> AsPredicate<'tcx> for PolyRegionOutlivesPredicate {
1993 fn as_predicate(&self) -> Predicate<'tcx> {
1994 Predicate::RegionOutlives(self.clone())
1998 impl<'tcx> AsPredicate<'tcx> for PolyTypeOutlivesPredicate<'tcx> {
1999 fn as_predicate(&self) -> Predicate<'tcx> {
2000 Predicate::TypeOutlives(self.clone())
2004 impl<'tcx> AsPredicate<'tcx> for PolyProjectionPredicate<'tcx> {
2005 fn as_predicate(&self) -> Predicate<'tcx> {
2006 Predicate::Projection(self.clone())
2010 impl<'tcx> Predicate<'tcx> {
2011 pub fn has_escaping_regions(&self) -> bool {
2013 Predicate::Trait(ref trait_ref) => trait_ref.has_escaping_regions(),
2014 Predicate::Equate(ref p) => p.has_escaping_regions(),
2015 Predicate::RegionOutlives(ref p) => p.has_escaping_regions(),
2016 Predicate::TypeOutlives(ref p) => p.has_escaping_regions(),
2017 Predicate::Projection(ref p) => p.has_escaping_regions(),
2021 pub fn to_opt_poly_trait_ref(&self) -> Option<PolyTraitRef<'tcx>> {
2023 Predicate::Trait(ref t) => {
2024 Some(t.to_poly_trait_ref())
2026 Predicate::Projection(..) |
2027 Predicate::Equate(..) |
2028 Predicate::RegionOutlives(..) |
2029 Predicate::TypeOutlives(..) => {
2036 /// Represents the bounds declared on a particular set of type
2037 /// parameters. Should eventually be generalized into a flag list of
2038 /// where clauses. You can obtain a `GenericBounds` list from a
2039 /// `Generics` by using the `to_bounds` method. Note that this method
2040 /// reflects an important semantic invariant of `GenericBounds`: while
2041 /// the bounds in a `Generics` are expressed in terms of the bound type
2042 /// parameters of the impl/trait/whatever, a `GenericBounds` instance
2043 /// represented a set of bounds for some particular instantiation,
2044 /// meaning that the generic parameters have been substituted with
2049 /// struct Foo<T,U:Bar<T>> { ... }
2051 /// Here, the `Generics` for `Foo` would contain a list of bounds like
2052 /// `[[], [U:Bar<T>]]`. Now if there were some particular reference
2053 /// like `Foo<int,uint>`, then the `GenericBounds` would be `[[],
2054 /// [uint:Bar<int>]]`.
2055 #[derive(Clone, Show)]
2056 pub struct GenericBounds<'tcx> {
2057 pub predicates: VecPerParamSpace<Predicate<'tcx>>,
2060 impl<'tcx> GenericBounds<'tcx> {
2061 pub fn empty() -> GenericBounds<'tcx> {
2062 GenericBounds { predicates: VecPerParamSpace::empty() }
2065 pub fn has_escaping_regions(&self) -> bool {
2066 self.predicates.any(|p| p.has_escaping_regions())
2069 pub fn is_empty(&self) -> bool {
2070 self.predicates.is_empty()
2074 impl<'tcx> TraitRef<'tcx> {
2075 pub fn new(def_id: ast::DefId, substs: &'tcx Substs<'tcx>) -> TraitRef<'tcx> {
2076 TraitRef { def_id: def_id, substs: substs }
2079 pub fn self_ty(&self) -> Ty<'tcx> {
2080 self.substs.self_ty().unwrap()
2083 pub fn input_types(&self) -> &[Ty<'tcx>] {
2084 // Select only the "input types" from a trait-reference. For
2085 // now this is all the types that appear in the
2086 // trait-reference, but it should eventually exclude
2087 // associated types.
2088 self.substs.types.as_slice()
2092 /// When type checking, we use the `ParameterEnvironment` to track
2093 /// details about the type/lifetime parameters that are in scope.
2094 /// It primarily stores the bounds information.
2096 /// Note: This information might seem to be redundant with the data in
2097 /// `tcx.ty_param_defs`, but it is not. That table contains the
2098 /// parameter definitions from an "outside" perspective, but this
2099 /// struct will contain the bounds for a parameter as seen from inside
2100 /// the function body. Currently the only real distinction is that
2101 /// bound lifetime parameters are replaced with free ones, but in the
2102 /// future I hope to refine the representation of types so as to make
2103 /// more distinctions clearer.
2105 pub struct ParameterEnvironment<'a, 'tcx:'a> {
2106 pub tcx: &'a ctxt<'tcx>,
2108 /// A substitution that can be applied to move from
2109 /// the "outer" view of a type or method to the "inner" view.
2110 /// In general, this means converting from bound parameters to
2111 /// free parameters. Since we currently represent bound/free type
2112 /// parameters in the same way, this only has an effect on regions.
2113 pub free_substs: Substs<'tcx>,
2115 /// Each type parameter has an implicit region bound that
2116 /// indicates it must outlive at least the function body (the user
2117 /// may specify stronger requirements). This field indicates the
2118 /// region of the callee.
2119 pub implicit_region_bound: ty::Region,
2121 /// Obligations that the caller must satisfy. This is basically
2122 /// the set of bounds on the in-scope type parameters, translated
2123 /// into Obligations.
2124 pub caller_bounds: ty::GenericBounds<'tcx>,
2126 /// Caches the results of trait selection. This cache is used
2127 /// for things that have to do with the parameters in scope.
2128 pub selection_cache: traits::SelectionCache<'tcx>,
2131 impl<'a, 'tcx> ParameterEnvironment<'a, 'tcx> {
2132 pub fn for_item(cx: &'a ctxt<'tcx>, id: NodeId) -> ParameterEnvironment<'a, 'tcx> {
2133 match cx.map.find(id) {
2134 Some(ast_map::NodeImplItem(ref impl_item)) => {
2136 ast::MethodImplItem(ref method) => {
2137 let method_def_id = ast_util::local_def(id);
2138 match ty::impl_or_trait_item(cx, method_def_id) {
2139 MethodTraitItem(ref method_ty) => {
2140 let method_generics = &method_ty.generics;
2141 construct_parameter_environment(
2144 method.pe_body().id)
2146 TypeTraitItem(_) => {
2148 .bug("ParameterEnvironment::for_item(): \
2149 can't create a parameter environment \
2150 for type trait items")
2154 ast::TypeImplItem(_) => {
2155 cx.sess.bug("ParameterEnvironment::for_item(): \
2156 can't create a parameter environment \
2157 for type impl items")
2161 Some(ast_map::NodeTraitItem(trait_method)) => {
2162 match *trait_method {
2163 ast::RequiredMethod(ref required) => {
2164 cx.sess.span_bug(required.span,
2165 "ParameterEnvironment::for_item():
2166 can't create a parameter \
2167 environment for required trait \
2170 ast::ProvidedMethod(ref method) => {
2171 let method_def_id = ast_util::local_def(id);
2172 match ty::impl_or_trait_item(cx, method_def_id) {
2173 MethodTraitItem(ref method_ty) => {
2174 let method_generics = &method_ty.generics;
2175 construct_parameter_environment(
2178 method.pe_body().id)
2180 TypeTraitItem(_) => {
2182 .bug("ParameterEnvironment::for_item(): \
2183 can't create a parameter environment \
2184 for type trait items")
2188 ast::TypeTraitItem(_) => {
2189 cx.sess.bug("ParameterEnvironment::from_item(): \
2190 can't create a parameter environment \
2191 for type trait items")
2195 Some(ast_map::NodeItem(item)) => {
2197 ast::ItemFn(_, _, _, _, ref body) => {
2198 // We assume this is a function.
2199 let fn_def_id = ast_util::local_def(id);
2200 let fn_pty = ty::lookup_item_type(cx, fn_def_id);
2202 construct_parameter_environment(cx,
2207 ast::ItemStruct(..) |
2209 ast::ItemConst(..) |
2210 ast::ItemStatic(..) => {
2211 let def_id = ast_util::local_def(id);
2212 let pty = ty::lookup_item_type(cx, def_id);
2213 construct_parameter_environment(cx, &pty.generics, id)
2216 cx.sess.span_bug(item.span,
2217 "ParameterEnvironment::from_item():
2218 can't create a parameter \
2219 environment for this kind of item")
2223 Some(ast_map::NodeExpr(..)) => {
2224 // This is a convenience to allow closures to work.
2225 ParameterEnvironment::for_item(cx, cx.map.get_parent(id))
2228 cx.sess.bug(&format!("ParameterEnvironment::from_item(): \
2229 `{}` is not an item",
2230 cx.map.node_to_string(id))[])
2236 /// A "type scheme", in ML terminology, is a type combined with some
2237 /// set of generic types that the type is, well, generic over. In Rust
2238 /// terms, it is the "type" of a fn item or struct -- this type will
2239 /// include various generic parameters that must be substituted when
2240 /// the item/struct is referenced. That is called converting the type
2241 /// scheme to a monotype.
2243 /// - `generics`: the set of type parameters and their bounds
2244 /// - `ty`: the base types, which may reference the parameters defined
2247 /// Note that TypeSchemes are also sometimes called "polytypes" (and
2248 /// in fact this struct used to carry that name, so you may find some
2249 /// stray references in a comment or something). We try to reserve the
2250 /// "poly" prefix to refer to higher-ranked things, as in
2252 #[derive(Clone, Show)]
2253 pub struct TypeScheme<'tcx> {
2254 pub generics: Generics<'tcx>,
2258 /// As `TypeScheme` but for a trait ref.
2259 pub struct TraitDef<'tcx> {
2260 pub unsafety: ast::Unsafety,
2262 /// Generic type definitions. Note that `Self` is listed in here
2263 /// as having a single bound, the trait itself (e.g., in the trait
2264 /// `Eq`, there is a single bound `Self : Eq`). This is so that
2265 /// default methods get to assume that the `Self` parameters
2266 /// implements the trait.
2267 pub generics: Generics<'tcx>,
2269 /// The "supertrait" bounds.
2270 pub bounds: ParamBounds<'tcx>,
2272 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
2274 /// A list of the associated types defined in this trait. Useful
2275 /// for resolving `X::Foo` type markers.
2276 pub associated_type_names: Vec<ast::Name>,
2279 /// Records the substitutions used to translate the polytype for an
2280 /// item into the monotype of an item reference.
2282 pub struct ItemSubsts<'tcx> {
2283 pub substs: Substs<'tcx>,
2286 /// Records information about each unboxed closure.
2288 pub struct UnboxedClosure<'tcx> {
2289 /// The type of the unboxed closure.
2290 pub closure_type: ClosureTy<'tcx>,
2291 /// The kind of unboxed closure this is.
2292 pub kind: UnboxedClosureKind,
2295 #[derive(Clone, Copy, PartialEq, Eq, Show)]
2296 pub enum UnboxedClosureKind {
2297 FnUnboxedClosureKind,
2298 FnMutUnboxedClosureKind,
2299 FnOnceUnboxedClosureKind,
2302 impl UnboxedClosureKind {
2303 pub fn trait_did(&self, cx: &ctxt) -> ast::DefId {
2304 let result = match *self {
2305 FnUnboxedClosureKind => cx.lang_items.require(FnTraitLangItem),
2306 FnMutUnboxedClosureKind => {
2307 cx.lang_items.require(FnMutTraitLangItem)
2309 FnOnceUnboxedClosureKind => {
2310 cx.lang_items.require(FnOnceTraitLangItem)
2314 Ok(trait_did) => trait_did,
2315 Err(err) => cx.sess.fatal(&err[]),
2320 pub trait UnboxedClosureTyper<'tcx> {
2321 fn param_env<'a>(&'a self) -> &'a ty::ParameterEnvironment<'a, 'tcx>;
2323 fn unboxed_closure_kind(&self,
2325 -> ty::UnboxedClosureKind;
2327 fn unboxed_closure_type(&self,
2329 substs: &subst::Substs<'tcx>)
2330 -> ty::ClosureTy<'tcx>;
2332 // Returns `None` if the upvar types cannot yet be definitively determined.
2333 fn unboxed_closure_upvars(&self,
2335 substs: &Substs<'tcx>)
2336 -> Option<Vec<UnboxedClosureUpvar<'tcx>>>;
2339 impl<'tcx> CommonTypes<'tcx> {
2340 fn new(arena: &'tcx TypedArena<TyS<'tcx>>,
2341 interner: &mut FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>)
2342 -> CommonTypes<'tcx>
2345 bool: intern_ty(arena, interner, ty_bool),
2346 char: intern_ty(arena, interner, ty_char),
2347 err: intern_ty(arena, interner, ty_err),
2348 int: intern_ty(arena, interner, ty_int(ast::TyIs(false))),
2349 i8: intern_ty(arena, interner, ty_int(ast::TyI8)),
2350 i16: intern_ty(arena, interner, ty_int(ast::TyI16)),
2351 i32: intern_ty(arena, interner, ty_int(ast::TyI32)),
2352 i64: intern_ty(arena, interner, ty_int(ast::TyI64)),
2353 uint: intern_ty(arena, interner, ty_uint(ast::TyUs(false))),
2354 u8: intern_ty(arena, interner, ty_uint(ast::TyU8)),
2355 u16: intern_ty(arena, interner, ty_uint(ast::TyU16)),
2356 u32: intern_ty(arena, interner, ty_uint(ast::TyU32)),
2357 u64: intern_ty(arena, interner, ty_uint(ast::TyU64)),
2358 f32: intern_ty(arena, interner, ty_float(ast::TyF32)),
2359 f64: intern_ty(arena, interner, ty_float(ast::TyF64)),
2364 pub fn mk_ctxt<'tcx>(s: Session,
2365 arenas: &'tcx CtxtArenas<'tcx>,
2367 named_region_map: resolve_lifetime::NamedRegionMap,
2368 map: ast_map::Map<'tcx>,
2369 freevars: RefCell<FreevarMap>,
2370 capture_modes: RefCell<CaptureModeMap>,
2371 region_maps: middle::region::RegionMaps,
2372 lang_items: middle::lang_items::LanguageItems,
2373 stability: stability::Index) -> ctxt<'tcx>
2375 let mut interner = FnvHashMap::new();
2376 let common_types = CommonTypes::new(&arenas.type_, &mut interner);
2380 interner: RefCell::new(interner),
2381 substs_interner: RefCell::new(FnvHashMap::new()),
2382 bare_fn_interner: RefCell::new(FnvHashMap::new()),
2383 region_interner: RefCell::new(FnvHashMap::new()),
2384 types: common_types,
2385 named_region_map: named_region_map,
2386 item_variance_map: RefCell::new(DefIdMap::new()),
2387 variance_computed: Cell::new(false),
2390 region_maps: region_maps,
2391 node_types: RefCell::new(FnvHashMap::new()),
2392 item_substs: RefCell::new(NodeMap::new()),
2393 trait_refs: RefCell::new(NodeMap::new()),
2394 trait_defs: RefCell::new(DefIdMap::new()),
2395 object_cast_map: RefCell::new(NodeMap::new()),
2397 intrinsic_defs: RefCell::new(DefIdMap::new()),
2399 tcache: RefCell::new(DefIdMap::new()),
2400 rcache: RefCell::new(FnvHashMap::new()),
2401 short_names_cache: RefCell::new(FnvHashMap::new()),
2402 tc_cache: RefCell::new(FnvHashMap::new()),
2403 ast_ty_to_ty_cache: RefCell::new(NodeMap::new()),
2404 enum_var_cache: RefCell::new(DefIdMap::new()),
2405 impl_or_trait_items: RefCell::new(DefIdMap::new()),
2406 trait_item_def_ids: RefCell::new(DefIdMap::new()),
2407 trait_items_cache: RefCell::new(DefIdMap::new()),
2408 impl_trait_cache: RefCell::new(DefIdMap::new()),
2409 ty_param_defs: RefCell::new(NodeMap::new()),
2410 adjustments: RefCell::new(NodeMap::new()),
2411 normalized_cache: RefCell::new(FnvHashMap::new()),
2412 lang_items: lang_items,
2413 provided_method_sources: RefCell::new(DefIdMap::new()),
2414 struct_fields: RefCell::new(DefIdMap::new()),
2415 destructor_for_type: RefCell::new(DefIdMap::new()),
2416 destructors: RefCell::new(DefIdSet::new()),
2417 trait_impls: RefCell::new(DefIdMap::new()),
2418 trait_negative_impls: RefCell::new(DefIdMap::new()),
2419 inherent_impls: RefCell::new(DefIdMap::new()),
2420 impl_items: RefCell::new(DefIdMap::new()),
2421 used_unsafe: RefCell::new(NodeSet::new()),
2422 used_mut_nodes: RefCell::new(NodeSet::new()),
2423 populated_external_types: RefCell::new(DefIdSet::new()),
2424 populated_external_traits: RefCell::new(DefIdSet::new()),
2425 upvar_borrow_map: RefCell::new(FnvHashMap::new()),
2426 extern_const_statics: RefCell::new(DefIdMap::new()),
2427 extern_const_variants: RefCell::new(DefIdMap::new()),
2428 method_map: RefCell::new(FnvHashMap::new()),
2429 dependency_formats: RefCell::new(FnvHashMap::new()),
2430 unboxed_closures: RefCell::new(DefIdMap::new()),
2431 node_lint_levels: RefCell::new(FnvHashMap::new()),
2432 transmute_restrictions: RefCell::new(Vec::new()),
2433 stability: RefCell::new(stability),
2434 capture_modes: capture_modes,
2435 associated_types: RefCell::new(DefIdMap::new()),
2436 selection_cache: traits::SelectionCache::new(),
2437 repr_hint_cache: RefCell::new(DefIdMap::new()),
2438 type_impls_copy_cache: RefCell::new(HashMap::new()),
2439 type_impls_sized_cache: RefCell::new(HashMap::new()),
2440 object_safety_cache: RefCell::new(DefIdMap::new()),
2444 // Type constructors
2446 impl<'tcx> ctxt<'tcx> {
2447 pub fn mk_substs(&self, substs: Substs<'tcx>) -> &'tcx Substs<'tcx> {
2448 if let Some(substs) = self.substs_interner.borrow().get(&substs) {
2452 let substs = self.arenas.substs.alloc(substs);
2453 self.substs_interner.borrow_mut().insert(substs, substs);
2457 pub fn mk_bare_fn(&self, bare_fn: BareFnTy<'tcx>) -> &'tcx BareFnTy<'tcx> {
2458 if let Some(bare_fn) = self.bare_fn_interner.borrow().get(&bare_fn) {
2462 let bare_fn = self.arenas.bare_fn.alloc(bare_fn);
2463 self.bare_fn_interner.borrow_mut().insert(bare_fn, bare_fn);
2467 pub fn mk_region(&self, region: Region) -> &'tcx Region {
2468 if let Some(region) = self.region_interner.borrow().get(®ion) {
2472 let region = self.arenas.region.alloc(region);
2473 self.region_interner.borrow_mut().insert(region, region);
2477 pub fn unboxed_closure_kind(&self,
2479 -> ty::UnboxedClosureKind
2481 self.unboxed_closures.borrow()[def_id].kind
2484 pub fn unboxed_closure_type(&self,
2486 substs: &subst::Substs<'tcx>)
2487 -> ty::ClosureTy<'tcx>
2489 self.unboxed_closures.borrow()[def_id].closure_type.subst(self, substs)
2493 // Interns a type/name combination, stores the resulting box in cx.interner,
2494 // and returns the box as cast to an unsafe ptr (see comments for Ty above).
2495 pub fn mk_t<'tcx>(cx: &ctxt<'tcx>, st: sty<'tcx>) -> Ty<'tcx> {
2496 let mut interner = cx.interner.borrow_mut();
2497 intern_ty(&cx.arenas.type_, &mut *interner, st)
2500 fn intern_ty<'tcx>(type_arena: &'tcx TypedArena<TyS<'tcx>>,
2501 interner: &mut FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>,
2505 match interner.get(&st) {
2506 Some(ty) => return *ty,
2510 let flags = FlagComputation::for_sty(&st);
2512 let ty = type_arena.alloc(TyS {
2515 region_depth: flags.depth,
2518 debug!("Interned type: {:?} Pointer: {:?}",
2519 ty, ty as *const _);
2521 interner.insert(InternedTy { ty: ty }, ty);
2526 struct FlagComputation {
2529 // maximum depth of any bound region that we have seen thus far
2533 impl FlagComputation {
2534 fn new() -> FlagComputation {
2535 FlagComputation { flags: NO_TYPE_FLAGS, depth: 0 }
2538 fn for_sty(st: &sty) -> FlagComputation {
2539 let mut result = FlagComputation::new();
2544 fn add_flags(&mut self, flags: TypeFlags) {
2545 self.flags = self.flags | flags;
2548 fn add_depth(&mut self, depth: u32) {
2549 if depth > self.depth {
2554 /// Adds the flags/depth from a set of types that appear within the current type, but within a
2556 fn add_bound_computation(&mut self, computation: &FlagComputation) {
2557 self.add_flags(computation.flags);
2559 // The types that contributed to `computation` occured within
2560 // a region binder, so subtract one from the region depth
2561 // within when adding the depth to `self`.
2562 let depth = computation.depth;
2564 self.add_depth(depth - 1);
2568 fn add_sty(&mut self, st: &sty) {
2578 // You might think that we could just return ty_err for
2579 // any type containing ty_err as a component, and get
2580 // rid of the HAS_TY_ERR flag -- likewise for ty_bot (with
2581 // the exception of function types that return bot).
2582 // But doing so caused sporadic memory corruption, and
2583 // neither I (tjc) nor nmatsakis could figure out why,
2584 // so we're doing it this way.
2586 self.add_flags(HAS_TY_ERR)
2589 &ty_param(ref p) => {
2590 if p.space == subst::SelfSpace {
2591 self.add_flags(HAS_SELF);
2593 self.add_flags(HAS_PARAMS);
2597 &ty_unboxed_closure(_, region, substs) => {
2598 self.add_region(*region);
2599 self.add_substs(substs);
2603 self.add_flags(HAS_TY_INFER)
2606 &ty_enum(_, substs) | &ty_struct(_, substs) => {
2607 self.add_substs(substs);
2610 &ty_projection(ref data) => {
2611 self.add_flags(HAS_PROJECTION);
2612 self.add_projection_ty(data);
2615 &ty_trait(box TyTrait { ref principal, ref bounds }) => {
2616 let mut computation = FlagComputation::new();
2617 computation.add_substs(principal.0.substs);
2618 for projection_bound in bounds.projection_bounds.iter() {
2619 let mut proj_computation = FlagComputation::new();
2620 proj_computation.add_projection_predicate(&projection_bound.0);
2621 computation.add_bound_computation(&proj_computation);
2623 self.add_bound_computation(&computation);
2625 self.add_bounds(bounds);
2628 &ty_uniq(tt) | &ty_vec(tt, _) | &ty_open(tt) => {
2636 &ty_rptr(r, ref m) => {
2637 self.add_region(*r);
2641 &ty_tup(ref ts) => {
2642 self.add_tys(&ts[]);
2645 &ty_bare_fn(_, ref f) => {
2646 self.add_fn_sig(&f.sig);
2651 fn add_ty(&mut self, ty: Ty) {
2652 self.add_flags(ty.flags);
2653 self.add_depth(ty.region_depth);
2656 fn add_tys(&mut self, tys: &[Ty]) {
2657 for &ty in tys.iter() {
2662 fn add_fn_sig(&mut self, fn_sig: &PolyFnSig) {
2663 let mut computation = FlagComputation::new();
2665 computation.add_tys(&fn_sig.0.inputs[]);
2667 if let ty::FnConverging(output) = fn_sig.0.output {
2668 computation.add_ty(output);
2671 self.add_bound_computation(&computation);
2674 fn add_region(&mut self, r: Region) {
2675 self.add_flags(HAS_REGIONS);
2677 ty::ReInfer(_) => { self.add_flags(HAS_RE_INFER); }
2678 ty::ReLateBound(debruijn, _) => {
2679 self.add_flags(HAS_RE_LATE_BOUND);
2680 self.add_depth(debruijn.depth);
2686 fn add_projection_predicate(&mut self, projection_predicate: &ProjectionPredicate) {
2687 self.add_projection_ty(&projection_predicate.projection_ty);
2688 self.add_ty(projection_predicate.ty);
2691 fn add_projection_ty(&mut self, projection_ty: &ProjectionTy) {
2692 self.add_substs(projection_ty.trait_ref.substs);
2695 fn add_substs(&mut self, substs: &Substs) {
2696 self.add_tys(substs.types.as_slice());
2697 match substs.regions {
2698 subst::ErasedRegions => {}
2699 subst::NonerasedRegions(ref regions) => {
2700 for &r in regions.iter() {
2707 fn add_bounds(&mut self, bounds: &ExistentialBounds) {
2708 self.add_region(bounds.region_bound);
2712 pub fn mk_mach_int<'tcx>(tcx: &ctxt<'tcx>, tm: ast::IntTy) -> Ty<'tcx> {
2714 ast::TyIs(_) => tcx.types.int,
2715 ast::TyI8 => tcx.types.i8,
2716 ast::TyI16 => tcx.types.i16,
2717 ast::TyI32 => tcx.types.i32,
2718 ast::TyI64 => tcx.types.i64,
2722 pub fn mk_mach_uint<'tcx>(tcx: &ctxt<'tcx>, tm: ast::UintTy) -> Ty<'tcx> {
2724 ast::TyUs(_) => tcx.types.uint,
2725 ast::TyU8 => tcx.types.u8,
2726 ast::TyU16 => tcx.types.u16,
2727 ast::TyU32 => tcx.types.u32,
2728 ast::TyU64 => tcx.types.u64,
2732 pub fn mk_mach_float<'tcx>(tcx: &ctxt<'tcx>, tm: ast::FloatTy) -> Ty<'tcx> {
2734 ast::TyF32 => tcx.types.f32,
2735 ast::TyF64 => tcx.types.f64,
2739 pub fn mk_str<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2743 pub fn mk_str_slice<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, m: ast::Mutability) -> Ty<'tcx> {
2746 ty: mk_t(cx, ty_str),
2751 pub fn mk_enum<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId, substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
2752 // take a copy of substs so that we own the vectors inside
2753 mk_t(cx, ty_enum(did, substs))
2756 pub fn mk_uniq<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_uniq(ty)) }
2758 pub fn mk_ptr<'tcx>(cx: &ctxt<'tcx>, tm: mt<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_ptr(tm)) }
2760 pub fn mk_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, tm: mt<'tcx>) -> Ty<'tcx> {
2761 mk_t(cx, ty_rptr(r, tm))
2764 pub fn mk_mut_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
2765 mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutMutable})
2767 pub fn mk_imm_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
2768 mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutImmutable})
2771 pub fn mk_mut_ptr<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
2772 mk_ptr(cx, mt {ty: ty, mutbl: ast::MutMutable})
2775 pub fn mk_imm_ptr<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
2776 mk_ptr(cx, mt {ty: ty, mutbl: ast::MutImmutable})
2779 pub fn mk_nil_ptr<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2780 mk_ptr(cx, mt {ty: mk_nil(cx), mutbl: ast::MutImmutable})
2783 pub fn mk_vec<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>, sz: Option<uint>) -> Ty<'tcx> {
2784 mk_t(cx, ty_vec(ty, sz))
2787 pub fn mk_slice<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, tm: mt<'tcx>) -> Ty<'tcx> {
2790 ty: mk_vec(cx, tm.ty, None),
2795 pub fn mk_tup<'tcx>(cx: &ctxt<'tcx>, ts: Vec<Ty<'tcx>>) -> Ty<'tcx> {
2796 mk_t(cx, ty_tup(ts))
2799 pub fn mk_nil<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2800 mk_tup(cx, Vec::new())
2803 pub fn mk_bare_fn<'tcx>(cx: &ctxt<'tcx>,
2804 opt_def_id: Option<ast::DefId>,
2805 fty: &'tcx BareFnTy<'tcx>) -> Ty<'tcx> {
2806 mk_t(cx, ty_bare_fn(opt_def_id, fty))
2809 pub fn mk_ctor_fn<'tcx>(cx: &ctxt<'tcx>,
2811 input_tys: &[Ty<'tcx>],
2812 output: Ty<'tcx>) -> Ty<'tcx> {
2813 let input_args = input_tys.iter().map(|ty| *ty).collect();
2816 cx.mk_bare_fn(BareFnTy {
2817 unsafety: ast::Unsafety::Normal,
2819 sig: ty::Binder(FnSig {
2821 output: ty::FnConverging(output),
2827 pub fn mk_trait<'tcx>(cx: &ctxt<'tcx>,
2828 principal: ty::PolyTraitRef<'tcx>,
2829 bounds: ExistentialBounds<'tcx>)
2832 assert!(bound_list_is_sorted(bounds.projection_bounds.as_slice()));
2834 let inner = box TyTrait {
2835 principal: principal,
2838 mk_t(cx, ty_trait(inner))
2841 fn bound_list_is_sorted(bounds: &[ty::PolyProjectionPredicate]) -> bool {
2842 bounds.len() == 0 ||
2843 bounds[1..].iter().enumerate().all(
2844 |(index, bound)| bounds[index].sort_key() <= bound.sort_key())
2847 pub fn sort_bounds_list(bounds: &mut [ty::PolyProjectionPredicate]) {
2848 bounds.sort_by(|a, b| a.sort_key().cmp(&b.sort_key()))
2851 pub fn mk_projection<'tcx>(cx: &ctxt<'tcx>,
2852 trait_ref: Rc<ty::TraitRef<'tcx>>,
2853 item_name: ast::Name)
2855 // take a copy of substs so that we own the vectors inside
2856 let inner = ProjectionTy { trait_ref: trait_ref, item_name: item_name };
2857 mk_t(cx, ty_projection(inner))
2860 pub fn mk_struct<'tcx>(cx: &ctxt<'tcx>, struct_id: ast::DefId,
2861 substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
2862 // take a copy of substs so that we own the vectors inside
2863 mk_t(cx, ty_struct(struct_id, substs))
2866 pub fn mk_unboxed_closure<'tcx>(cx: &ctxt<'tcx>, closure_id: ast::DefId,
2867 region: &'tcx Region, substs: &'tcx Substs<'tcx>)
2869 mk_t(cx, ty_unboxed_closure(closure_id, region, substs))
2872 pub fn mk_var<'tcx>(cx: &ctxt<'tcx>, v: TyVid) -> Ty<'tcx> {
2873 mk_infer(cx, TyVar(v))
2876 pub fn mk_int_var<'tcx>(cx: &ctxt<'tcx>, v: IntVid) -> Ty<'tcx> {
2877 mk_infer(cx, IntVar(v))
2880 pub fn mk_float_var<'tcx>(cx: &ctxt<'tcx>, v: FloatVid) -> Ty<'tcx> {
2881 mk_infer(cx, FloatVar(v))
2884 pub fn mk_infer<'tcx>(cx: &ctxt<'tcx>, it: InferTy) -> Ty<'tcx> {
2885 mk_t(cx, ty_infer(it))
2888 pub fn mk_param<'tcx>(cx: &ctxt<'tcx>,
2889 space: subst::ParamSpace,
2891 name: ast::Name) -> Ty<'tcx> {
2892 mk_t(cx, ty_param(ParamTy { space: space, idx: index, name: name }))
2895 pub fn mk_self_type<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2896 mk_param(cx, subst::SelfSpace, 0, special_idents::type_self.name)
2899 pub fn mk_param_from_def<'tcx>(cx: &ctxt<'tcx>, def: &TypeParameterDef) -> Ty<'tcx> {
2900 mk_param(cx, def.space, def.index, def.name)
2903 pub fn mk_open<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_open(ty)) }
2905 impl<'tcx> TyS<'tcx> {
2906 /// Iterator that walks `self` and any types reachable from
2907 /// `self`, in depth-first order. Note that just walks the types
2908 /// that appear in `self`, it does not descend into the fields of
2909 /// structs or variants. For example:
2913 /// Foo<Bar<int>> => { Foo<Bar<int>>, Bar<int>, int }
2914 /// [int] => { [int], int }
2916 pub fn walk(&'tcx self) -> TypeWalker<'tcx> {
2917 TypeWalker::new(self)
2920 /// Iterator that walks types reachable from `self`, in
2921 /// depth-first order. Note that this is a shallow walk. For
2926 /// Foo<Bar<int>> => { Bar<int>, int }
2927 /// [int] => { int }
2929 pub fn walk_children(&'tcx self) -> TypeWalker<'tcx> {
2930 // Walks type reachable from `self` but not `self
2931 let mut walker = self.walk();
2932 let r = walker.next();
2933 assert_eq!(r, Some(self));
2938 pub fn walk_ty<'tcx, F>(ty_root: Ty<'tcx>, mut f: F)
2939 where F: FnMut(Ty<'tcx>),
2941 for ty in ty_root.walk() {
2946 /// Walks `ty` and any types appearing within `ty`, invoking the
2947 /// callback `f` on each type. If the callback returns false, then the
2948 /// children of the current type are ignored.
2950 /// Note: prefer `ty.walk()` where possible.
2951 pub fn maybe_walk_ty<'tcx,F>(ty_root: Ty<'tcx>, mut f: F)
2952 where F : FnMut(Ty<'tcx>) -> bool
2954 let mut walker = ty_root.walk();
2955 while let Some(ty) = walker.next() {
2957 walker.skip_current_subtree();
2962 // Folds types from the bottom up.
2963 pub fn fold_ty<'tcx, F>(cx: &ctxt<'tcx>, t0: Ty<'tcx>,
2966 F: FnMut(Ty<'tcx>) -> Ty<'tcx>,
2968 let mut f = ty_fold::BottomUpFolder {tcx: cx, fldop: fldop};
2973 pub fn new(space: subst::ParamSpace,
2977 ParamTy { space: space, idx: index, name: name }
2980 pub fn for_self() -> ParamTy {
2981 ParamTy::new(subst::SelfSpace, 0, special_idents::type_self.name)
2984 pub fn for_def(def: &TypeParameterDef) -> ParamTy {
2985 ParamTy::new(def.space, def.index, def.name)
2988 pub fn to_ty<'tcx>(self, tcx: &ty::ctxt<'tcx>) -> Ty<'tcx> {
2989 ty::mk_param(tcx, self.space, self.idx, self.name)
2992 pub fn is_self(&self) -> bool {
2993 self.space == subst::SelfSpace && self.idx == 0
2997 impl<'tcx> ItemSubsts<'tcx> {
2998 pub fn empty() -> ItemSubsts<'tcx> {
2999 ItemSubsts { substs: Substs::empty() }
3002 pub fn is_noop(&self) -> bool {
3003 self.substs.is_noop()
3007 impl<'tcx> ParamBounds<'tcx> {
3008 pub fn empty() -> ParamBounds<'tcx> {
3010 builtin_bounds: empty_builtin_bounds(),
3011 trait_bounds: Vec::new(),
3012 region_bounds: Vec::new(),
3013 projection_bounds: Vec::new(),
3020 pub fn type_is_nil(ty: Ty) -> bool {
3022 ty_tup(ref tys) => tys.is_empty(),
3027 pub fn type_is_error(ty: Ty) -> bool {
3028 ty.flags.intersects(HAS_TY_ERR)
3031 pub fn type_needs_subst(ty: Ty) -> bool {
3032 ty.flags.intersects(NEEDS_SUBST)
3035 pub fn trait_ref_contains_error(tref: &ty::TraitRef) -> bool {
3036 tref.substs.types.any(|&ty| type_is_error(ty))
3039 pub fn type_is_ty_var(ty: Ty) -> bool {
3041 ty_infer(TyVar(_)) => true,
3046 pub fn type_is_bool(ty: Ty) -> bool { ty.sty == ty_bool }
3048 pub fn type_is_self(ty: Ty) -> bool {
3050 ty_param(ref p) => p.space == subst::SelfSpace,
3055 fn type_is_slice(ty: Ty) -> bool {
3057 ty_ptr(mt) | ty_rptr(_, mt) => match mt.ty.sty {
3058 ty_vec(_, None) | ty_str => true,
3065 pub fn type_is_vec(ty: Ty) -> bool {
3068 ty_ptr(mt{ty, ..}) | ty_rptr(_, mt{ty, ..}) |
3069 ty_uniq(ty) => match ty.sty {
3070 ty_vec(_, None) => true,
3077 pub fn type_is_structural(ty: Ty) -> bool {
3079 ty_struct(..) | ty_tup(_) | ty_enum(..) |
3080 ty_vec(_, Some(_)) | ty_unboxed_closure(..) => true,
3081 _ => type_is_slice(ty) | type_is_trait(ty)
3085 pub fn type_is_simd(cx: &ctxt, ty: Ty) -> bool {
3087 ty_struct(did, _) => lookup_simd(cx, did),
3092 pub fn sequence_element_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
3094 ty_vec(ty, _) => ty,
3095 ty_str => mk_mach_uint(cx, ast::TyU8),
3096 ty_open(ty) => sequence_element_type(cx, ty),
3097 _ => cx.sess.bug(&format!("sequence_element_type called on non-sequence value: {}",
3098 ty_to_string(cx, ty))[]),
3102 pub fn simd_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
3104 ty_struct(did, substs) => {
3105 let fields = lookup_struct_fields(cx, did);
3106 lookup_field_type(cx, did, fields[0].id, substs)
3108 _ => panic!("simd_type called on invalid type")
3112 pub fn simd_size(cx: &ctxt, ty: Ty) -> uint {
3114 ty_struct(did, _) => {
3115 let fields = lookup_struct_fields(cx, did);
3118 _ => panic!("simd_size called on invalid type")
3122 pub fn type_is_region_ptr(ty: Ty) -> bool {
3124 ty_rptr(..) => true,
3129 pub fn type_is_unsafe_ptr(ty: Ty) -> bool {
3131 ty_ptr(_) => return true,
3136 pub fn type_is_unique(ty: Ty) -> bool {
3138 ty_uniq(_) => match ty.sty {
3139 ty_trait(..) => false,
3147 A scalar type is one that denotes an atomic datum, with no sub-components.
3148 (A ty_ptr is scalar because it represents a non-managed pointer, so its
3149 contents are abstract to rustc.)
3151 pub fn type_is_scalar(ty: Ty) -> bool {
3153 ty_bool | ty_char | ty_int(_) | ty_float(_) | ty_uint(_) |
3154 ty_infer(IntVar(_)) | ty_infer(FloatVar(_)) |
3155 ty_bare_fn(..) | ty_ptr(_) => true,
3156 ty_tup(ref tys) if tys.is_empty() => true,
3161 /// Returns true if this type is a floating point type and false otherwise.
3162 pub fn type_is_floating_point(ty: Ty) -> bool {
3164 ty_float(_) => true,
3169 /// Type contents is how the type checker reasons about kinds.
3170 /// They track what kinds of things are found within a type. You can
3171 /// think of them as kind of an "anti-kind". They track the kinds of values
3172 /// and thinks that are contained in types. Having a larger contents for
3173 /// a type tends to rule that type *out* from various kinds. For example,
3174 /// a type that contains a reference is not sendable.
3176 /// The reason we compute type contents and not kinds is that it is
3177 /// easier for me (nmatsakis) to think about what is contained within
3178 /// a type than to think about what is *not* contained within a type.
3179 #[derive(Clone, Copy)]
3180 pub struct TypeContents {
3184 macro_rules! def_type_content_sets {
3185 (mod $mname:ident { $($name:ident = $bits:expr),+ }) => {
3186 #[allow(non_snake_case)]
3188 use middle::ty::TypeContents;
3190 #[allow(non_upper_case_globals)]
3191 pub const $name: TypeContents = TypeContents { bits: $bits };
3197 def_type_content_sets! {
3199 None = 0b0000_0000__0000_0000__0000,
3201 // Things that are interior to the value (first nibble):
3202 InteriorUnsized = 0b0000_0000__0000_0000__0001,
3203 InteriorUnsafe = 0b0000_0000__0000_0000__0010,
3204 InteriorParam = 0b0000_0000__0000_0000__0100,
3205 // InteriorAll = 0b00000000__00000000__1111,
3207 // Things that are owned by the value (second and third nibbles):
3208 OwnsOwned = 0b0000_0000__0000_0001__0000,
3209 OwnsDtor = 0b0000_0000__0000_0010__0000,
3210 OwnsManaged /* see [1] below */ = 0b0000_0000__0000_0100__0000,
3211 OwnsAll = 0b0000_0000__1111_1111__0000,
3213 // Things that are reachable by the value in any way (fourth nibble):
3214 ReachesBorrowed = 0b0000_0010__0000_0000__0000,
3215 // ReachesManaged /* see [1] below */ = 0b0000_0100__0000_0000__0000,
3216 ReachesMutable = 0b0000_1000__0000_0000__0000,
3217 ReachesFfiUnsafe = 0b0010_0000__0000_0000__0000,
3218 ReachesAll = 0b0011_1111__0000_0000__0000,
3220 // Things that mean drop glue is necessary
3221 NeedsDrop = 0b0000_0000__0000_0111__0000,
3223 // Things that prevent values from being considered sized
3224 Nonsized = 0b0000_0000__0000_0000__0001,
3226 // Bits to set when a managed value is encountered
3228 // [1] Do not set the bits TC::OwnsManaged or
3229 // TC::ReachesManaged directly, instead reference
3230 // TC::Managed to set them both at once.
3231 Managed = 0b0000_0100__0000_0100__0000,
3234 All = 0b1111_1111__1111_1111__1111
3239 pub fn when(&self, cond: bool) -> TypeContents {
3240 if cond {*self} else {TC::None}
3243 pub fn intersects(&self, tc: TypeContents) -> bool {
3244 (self.bits & tc.bits) != 0
3247 pub fn owns_managed(&self) -> bool {
3248 self.intersects(TC::OwnsManaged)
3251 pub fn owns_owned(&self) -> bool {
3252 self.intersects(TC::OwnsOwned)
3255 pub fn is_sized(&self, _: &ctxt) -> bool {
3256 !self.intersects(TC::Nonsized)
3259 pub fn interior_param(&self) -> bool {
3260 self.intersects(TC::InteriorParam)
3263 pub fn interior_unsafe(&self) -> bool {
3264 self.intersects(TC::InteriorUnsafe)
3267 pub fn interior_unsized(&self) -> bool {
3268 self.intersects(TC::InteriorUnsized)
3271 pub fn needs_drop(&self, _: &ctxt) -> bool {
3272 self.intersects(TC::NeedsDrop)
3275 /// Includes only those bits that still apply when indirected through a `Box` pointer
3276 pub fn owned_pointer(&self) -> TypeContents {
3278 *self & (TC::OwnsAll | TC::ReachesAll))
3281 /// Includes only those bits that still apply when indirected through a reference (`&`)
3282 pub fn reference(&self, bits: TypeContents) -> TypeContents {
3284 *self & TC::ReachesAll)
3287 /// Includes only those bits that still apply when indirected through a managed pointer (`@`)
3288 pub fn managed_pointer(&self) -> TypeContents {
3290 *self & TC::ReachesAll)
3293 /// Includes only those bits that still apply when indirected through an unsafe pointer (`*`)
3294 pub fn unsafe_pointer(&self) -> TypeContents {
3295 *self & TC::ReachesAll
3298 pub fn union<T, F>(v: &[T], mut f: F) -> TypeContents where
3299 F: FnMut(&T) -> TypeContents,
3301 v.iter().fold(TC::None, |tc, ty| tc | f(ty))
3304 pub fn has_dtor(&self) -> bool {
3305 self.intersects(TC::OwnsDtor)
3309 impl ops::BitOr for TypeContents {
3310 type Output = TypeContents;
3312 fn bitor(self, other: TypeContents) -> TypeContents {
3313 TypeContents {bits: self.bits | other.bits}
3317 impl ops::BitAnd for TypeContents {
3318 type Output = TypeContents;
3320 fn bitand(self, other: TypeContents) -> TypeContents {
3321 TypeContents {bits: self.bits & other.bits}
3325 impl ops::Sub for TypeContents {
3326 type Output = TypeContents;
3328 fn sub(self, other: TypeContents) -> TypeContents {
3329 TypeContents {bits: self.bits & !other.bits}
3333 impl fmt::Show for TypeContents {
3334 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
3335 write!(f, "TypeContents({:b})", self.bits)
3339 pub fn type_interior_is_unsafe<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
3340 type_contents(cx, ty).interior_unsafe()
3343 pub fn type_contents<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> TypeContents {
3344 return memoized(&cx.tc_cache, ty, |ty| {
3345 tc_ty(cx, ty, &mut FnvHashMap::new())
3348 fn tc_ty<'tcx>(cx: &ctxt<'tcx>,
3350 cache: &mut FnvHashMap<Ty<'tcx>, TypeContents>) -> TypeContents
3352 // Subtle: Note that we are *not* using cx.tc_cache here but rather a
3353 // private cache for this walk. This is needed in the case of cyclic
3356 // struct List { next: Box<Option<List>>, ... }
3358 // When computing the type contents of such a type, we wind up deeply
3359 // recursing as we go. So when we encounter the recursive reference
3360 // to List, we temporarily use TC::None as its contents. Later we'll
3361 // patch up the cache with the correct value, once we've computed it
3362 // (this is basically a co-inductive process, if that helps). So in
3363 // the end we'll compute TC::OwnsOwned, in this case.
3365 // The problem is, as we are doing the computation, we will also
3366 // compute an *intermediate* contents for, e.g., Option<List> of
3367 // TC::None. This is ok during the computation of List itself, but if
3368 // we stored this intermediate value into cx.tc_cache, then later
3369 // requests for the contents of Option<List> would also yield TC::None
3370 // which is incorrect. This value was computed based on the crutch
3371 // value for the type contents of list. The correct value is
3372 // TC::OwnsOwned. This manifested as issue #4821.
3373 match cache.get(&ty) {
3374 Some(tc) => { return *tc; }
3377 match cx.tc_cache.borrow().get(&ty) { // Must check both caches!
3378 Some(tc) => { return *tc; }
3381 cache.insert(ty, TC::None);
3383 let result = match ty.sty {
3384 // uint and int are ffi-unsafe
3385 ty_uint(ast::TyUs(_)) | ty_int(ast::TyIs(_)) => {
3386 TC::ReachesFfiUnsafe
3389 // Scalar and unique types are sendable, and durable
3390 ty_infer(ty::FreshIntTy(_)) |
3391 ty_bool | ty_int(_) | ty_uint(_) | ty_float(_) |
3392 ty_bare_fn(..) | ty::ty_char => {
3397 TC::ReachesFfiUnsafe | match typ.sty {
3398 ty_str => TC::OwnsOwned,
3399 _ => tc_ty(cx, typ, cache).owned_pointer(),
3403 ty_trait(box TyTrait { ref bounds, .. }) => {
3404 object_contents(bounds) | TC::ReachesFfiUnsafe | TC::Nonsized
3408 tc_ty(cx, mt.ty, cache).unsafe_pointer()
3411 ty_rptr(r, ref mt) => {
3412 TC::ReachesFfiUnsafe | match mt.ty.sty {
3413 ty_str => borrowed_contents(*r, ast::MutImmutable),
3414 ty_vec(..) => tc_ty(cx, mt.ty, cache).reference(borrowed_contents(*r,
3416 _ => tc_ty(cx, mt.ty, cache).reference(borrowed_contents(*r, mt.mutbl)),
3420 ty_vec(ty, Some(_)) => {
3421 tc_ty(cx, ty, cache)
3424 ty_vec(ty, None) => {
3425 tc_ty(cx, ty, cache) | TC::Nonsized
3427 ty_str => TC::Nonsized,
3429 ty_struct(did, substs) => {
3430 let flds = struct_fields(cx, did, substs);
3432 TypeContents::union(&flds[],
3433 |f| tc_mt(cx, f.mt, cache));
3435 if !lookup_repr_hints(cx, did).contains(&attr::ReprExtern) {
3436 res = res | TC::ReachesFfiUnsafe;
3439 if ty::has_dtor(cx, did) {
3440 res = res | TC::OwnsDtor;
3442 apply_lang_items(cx, did, res)
3445 ty_unboxed_closure(did, r, substs) => {
3446 // FIXME(#14449): `borrowed_contents` below assumes `&mut`
3448 let param_env = ty::empty_parameter_environment(cx);
3449 let upvars = unboxed_closure_upvars(¶m_env, did, substs).unwrap();
3450 TypeContents::union(upvars.as_slice(),
3451 |f| tc_ty(cx, f.ty, cache))
3452 | borrowed_contents(*r, MutMutable)
3455 ty_tup(ref tys) => {
3456 TypeContents::union(&tys[],
3457 |ty| tc_ty(cx, *ty, cache))
3460 ty_enum(did, substs) => {
3461 let variants = substd_enum_variants(cx, did, substs);
3463 TypeContents::union(&variants[], |variant| {
3464 TypeContents::union(&variant.args[],
3466 tc_ty(cx, *arg_ty, cache)
3470 if ty::has_dtor(cx, did) {
3471 res = res | TC::OwnsDtor;
3474 if variants.len() != 0 {
3475 let repr_hints = lookup_repr_hints(cx, did);
3476 if repr_hints.len() > 1 {
3477 // this is an error later on, but this type isn't safe
3478 res = res | TC::ReachesFfiUnsafe;
3481 match repr_hints.get(0) {
3482 Some(h) => if !h.is_ffi_safe() {
3483 res = res | TC::ReachesFfiUnsafe;
3487 res = res | TC::ReachesFfiUnsafe;
3489 // We allow ReprAny enums if they are eligible for
3490 // the nullable pointer optimization and the
3491 // contained type is an `extern fn`
3493 if variants.len() == 2 {
3494 let mut data_idx = 0;
3496 if variants[0].args.len() == 0 {
3500 if variants[data_idx].args.len() == 1 {
3501 match variants[data_idx].args[0].sty {
3502 ty_bare_fn(..) => { res = res - TC::ReachesFfiUnsafe; }
3512 apply_lang_items(cx, did, res)
3521 let result = tc_ty(cx, ty, cache);
3522 assert!(!result.is_sized(cx));
3523 result.unsafe_pointer() | TC::Nonsized
3528 cx.sess.bug("asked to compute contents of error type");
3532 cache.insert(ty, result);
3536 fn tc_mt<'tcx>(cx: &ctxt<'tcx>,
3538 cache: &mut FnvHashMap<Ty<'tcx>, TypeContents>) -> TypeContents
3540 let mc = TC::ReachesMutable.when(mt.mutbl == MutMutable);
3541 mc | tc_ty(cx, mt.ty, cache)
3544 fn apply_lang_items(cx: &ctxt, did: ast::DefId, tc: TypeContents)
3546 if Some(did) == cx.lang_items.managed_bound() {
3548 } else if Some(did) == cx.lang_items.unsafe_type() {
3549 tc | TC::InteriorUnsafe
3555 /// Type contents due to containing a reference with the region `region` and borrow kind `bk`
3556 fn borrowed_contents(region: ty::Region,
3557 mutbl: ast::Mutability)
3559 let b = match mutbl {
3560 ast::MutMutable => TC::ReachesMutable,
3561 ast::MutImmutable => TC::None,
3563 b | (TC::ReachesBorrowed).when(region != ty::ReStatic)
3566 fn object_contents(bounds: &ExistentialBounds) -> TypeContents {
3567 // These are the type contents of the (opaque) interior. We
3568 // make no assumptions (other than that it cannot have an
3569 // in-scope type parameter within, which makes no sense).
3570 let mut tc = TC::All - TC::InteriorParam;
3571 for bound in bounds.builtin_bounds.iter() {
3572 tc = tc - match bound {
3573 BoundSync | BoundSend | BoundCopy => TC::None,
3574 BoundSized => TC::Nonsized,
3581 fn type_impls_bound<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3582 cache: &RefCell<HashMap<Ty<'tcx>,bool>>,
3584 bound: ty::BuiltinBound,
3588 assert!(!ty::type_needs_infer(ty));
3590 if !type_has_params(ty) && !type_has_self(ty) {
3591 match cache.borrow().get(&ty) {
3594 debug!("type_impls_bound({}, {:?}) = {:?} (cached)",
3595 ty.repr(param_env.tcx),
3603 let infcx = infer::new_infer_ctxt(param_env.tcx);
3605 let is_impld = traits::type_known_to_meet_builtin_bound(&infcx, param_env, ty, bound, span);
3607 debug!("type_impls_bound({}, {:?}) = {:?}",
3608 ty.repr(param_env.tcx),
3612 if !type_has_params(ty) && !type_has_self(ty) {
3613 let old_value = cache.borrow_mut().insert(ty, is_impld);
3614 assert!(old_value.is_none());
3620 pub fn type_moves_by_default<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3625 let tcx = param_env.tcx;
3626 !type_impls_bound(param_env, &tcx.type_impls_copy_cache, ty, ty::BoundCopy, span)
3629 pub fn type_is_sized<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3634 let tcx = param_env.tcx;
3635 type_impls_bound(param_env, &tcx.type_impls_sized_cache, ty, ty::BoundSized, span)
3638 pub fn is_ffi_safe<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
3639 !type_contents(cx, ty).intersects(TC::ReachesFfiUnsafe)
3642 // True if instantiating an instance of `r_ty` requires an instance of `r_ty`.
3643 pub fn is_instantiable<'tcx>(cx: &ctxt<'tcx>, r_ty: Ty<'tcx>) -> bool {
3644 fn type_requires<'tcx>(cx: &ctxt<'tcx>, seen: &mut Vec<DefId>,
3645 r_ty: Ty<'tcx>, ty: Ty<'tcx>) -> bool {
3646 debug!("type_requires({:?}, {:?})?",
3647 ::util::ppaux::ty_to_string(cx, r_ty),
3648 ::util::ppaux::ty_to_string(cx, ty));
3650 let r = r_ty == ty || subtypes_require(cx, seen, r_ty, ty);
3652 debug!("type_requires({:?}, {:?})? {:?}",
3653 ::util::ppaux::ty_to_string(cx, r_ty),
3654 ::util::ppaux::ty_to_string(cx, ty),
3659 fn subtypes_require<'tcx>(cx: &ctxt<'tcx>, seen: &mut Vec<DefId>,
3660 r_ty: Ty<'tcx>, ty: Ty<'tcx>) -> bool {
3661 debug!("subtypes_require({:?}, {:?})?",
3662 ::util::ppaux::ty_to_string(cx, r_ty),
3663 ::util::ppaux::ty_to_string(cx, ty));
3665 let r = match ty.sty {
3666 // fixed length vectors need special treatment compared to
3667 // normal vectors, since they don't necessarily have the
3668 // possibility to have length zero.
3669 ty_vec(_, Some(0)) => false, // don't need no contents
3670 ty_vec(ty, Some(_)) => type_requires(cx, seen, r_ty, ty),
3681 ty_vec(_, None) => {
3684 ty_uniq(typ) | ty_open(typ) => {
3685 type_requires(cx, seen, r_ty, typ)
3687 ty_rptr(_, ref mt) => {
3688 type_requires(cx, seen, r_ty, mt.ty)
3692 false // unsafe ptrs can always be NULL
3699 ty_struct(ref did, _) if seen.contains(did) => {
3703 ty_struct(did, substs) => {
3705 let fields = struct_fields(cx, did, substs);
3706 let r = fields.iter().any(|f| type_requires(cx, seen, r_ty, f.mt.ty));
3707 seen.pop().unwrap();
3713 ty_unboxed_closure(..) => {
3714 // this check is run on type definitions, so we don't expect to see
3715 // inference by-products or unboxed closure types
3716 cx.sess.bug(format!("requires check invoked on inapplicable type: {:?}",
3721 ts.iter().any(|ty| type_requires(cx, seen, r_ty, *ty))
3724 ty_enum(ref did, _) if seen.contains(did) => {
3728 ty_enum(did, substs) => {
3730 let vs = enum_variants(cx, did);
3731 let r = !vs.is_empty() && vs.iter().all(|variant| {
3732 variant.args.iter().any(|aty| {
3733 let sty = aty.subst(cx, substs);
3734 type_requires(cx, seen, r_ty, sty)
3737 seen.pop().unwrap();
3742 debug!("subtypes_require({:?}, {:?})? {:?}",
3743 ::util::ppaux::ty_to_string(cx, r_ty),
3744 ::util::ppaux::ty_to_string(cx, ty),
3750 let mut seen = Vec::new();
3751 !subtypes_require(cx, &mut seen, r_ty, r_ty)
3754 /// Describes whether a type is representable. For types that are not
3755 /// representable, 'SelfRecursive' and 'ContainsRecursive' are used to
3756 /// distinguish between types that are recursive with themselves and types that
3757 /// contain a different recursive type. These cases can therefore be treated
3758 /// differently when reporting errors.
3760 /// The ordering of the cases is significant. They are sorted so that cmp::max
3761 /// will keep the "more erroneous" of two values.
3762 #[derive(Copy, PartialOrd, Ord, Eq, PartialEq, Show)]
3763 pub enum Representability {
3769 /// Check whether a type is representable. This means it cannot contain unboxed
3770 /// structural recursion. This check is needed for structs and enums.
3771 pub fn is_type_representable<'tcx>(cx: &ctxt<'tcx>, sp: Span, ty: Ty<'tcx>)
3772 -> Representability {
3774 // Iterate until something non-representable is found
3775 fn find_nonrepresentable<'tcx, It: Iterator<Item=Ty<'tcx>>>(cx: &ctxt<'tcx>, sp: Span,
3776 seen: &mut Vec<Ty<'tcx>>,
3778 -> Representability {
3779 iter.fold(Representable,
3780 |r, ty| cmp::max(r, is_type_structurally_recursive(cx, sp, seen, ty)))
3783 fn are_inner_types_recursive<'tcx>(cx: &ctxt<'tcx>, sp: Span,
3784 seen: &mut Vec<Ty<'tcx>>, ty: Ty<'tcx>)
3785 -> Representability {
3788 find_nonrepresentable(cx, sp, seen, ts.iter().map(|ty| *ty))
3790 // Fixed-length vectors.
3791 // FIXME(#11924) Behavior undecided for zero-length vectors.
3792 ty_vec(ty, Some(_)) => {
3793 is_type_structurally_recursive(cx, sp, seen, ty)
3795 ty_struct(did, substs) => {
3796 let fields = struct_fields(cx, did, substs);
3797 find_nonrepresentable(cx, sp, seen, fields.iter().map(|f| f.mt.ty))
3799 ty_enum(did, substs) => {
3800 let vs = enum_variants(cx, did);
3801 let iter = vs.iter()
3802 .flat_map(|variant| { variant.args.iter() })
3803 .map(|aty| { aty.subst_spanned(cx, substs, Some(sp)) });
3805 find_nonrepresentable(cx, sp, seen, iter)
3807 ty_unboxed_closure(..) => {
3808 // this check is run on type definitions, so we don't expect to see
3809 // unboxed closure types
3810 cx.sess.bug(format!("requires check invoked on inapplicable type: {:?}",
3817 fn same_struct_or_enum_def_id(ty: Ty, did: DefId) -> bool {
3819 ty_struct(ty_did, _) | ty_enum(ty_did, _) => {
3826 fn same_type<'tcx>(a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
3827 match (&a.sty, &b.sty) {
3828 (&ty_struct(did_a, ref substs_a), &ty_struct(did_b, ref substs_b)) |
3829 (&ty_enum(did_a, ref substs_a), &ty_enum(did_b, ref substs_b)) => {
3834 let types_a = substs_a.types.get_slice(subst::TypeSpace);
3835 let types_b = substs_b.types.get_slice(subst::TypeSpace);
3837 let pairs = types_a.iter().zip(types_b.iter());
3839 pairs.all(|(&a, &b)| same_type(a, b))
3847 // Does the type `ty` directly (without indirection through a pointer)
3848 // contain any types on stack `seen`?
3849 fn is_type_structurally_recursive<'tcx>(cx: &ctxt<'tcx>, sp: Span,
3850 seen: &mut Vec<Ty<'tcx>>,
3851 ty: Ty<'tcx>) -> Representability {
3852 debug!("is_type_structurally_recursive: {:?}",
3853 ::util::ppaux::ty_to_string(cx, ty));
3856 ty_struct(did, _) | ty_enum(did, _) => {
3858 // Iterate through stack of previously seen types.
3859 let mut iter = seen.iter();
3861 // The first item in `seen` is the type we are actually curious about.
3862 // We want to return SelfRecursive if this type contains itself.
3863 // It is important that we DON'T take generic parameters into account
3864 // for this check, so that Bar<T> in this example counts as SelfRecursive:
3867 // struct Bar<T> { x: Bar<Foo> }
3870 Some(&seen_type) => {
3871 if same_struct_or_enum_def_id(seen_type, did) {
3872 debug!("SelfRecursive: {:?} contains {:?}",
3873 ::util::ppaux::ty_to_string(cx, seen_type),
3874 ::util::ppaux::ty_to_string(cx, ty));
3875 return SelfRecursive;
3881 // We also need to know whether the first item contains other types that
3882 // are structurally recursive. If we don't catch this case, we will recurse
3883 // infinitely for some inputs.
3885 // It is important that we DO take generic parameters into account here,
3886 // so that code like this is considered SelfRecursive, not ContainsRecursive:
3888 // struct Foo { Option<Option<Foo>> }
3890 for &seen_type in iter {
3891 if same_type(ty, seen_type) {
3892 debug!("ContainsRecursive: {:?} contains {:?}",
3893 ::util::ppaux::ty_to_string(cx, seen_type),
3894 ::util::ppaux::ty_to_string(cx, ty));
3895 return ContainsRecursive;
3900 // For structs and enums, track all previously seen types by pushing them
3901 // onto the 'seen' stack.
3903 let out = are_inner_types_recursive(cx, sp, seen, ty);
3908 // No need to push in other cases.
3909 are_inner_types_recursive(cx, sp, seen, ty)
3914 debug!("is_type_representable: {:?}",
3915 ::util::ppaux::ty_to_string(cx, ty));
3917 // To avoid a stack overflow when checking an enum variant or struct that
3918 // contains a different, structurally recursive type, maintain a stack
3919 // of seen types and check recursion for each of them (issues #3008, #3779).
3920 let mut seen: Vec<Ty> = Vec::new();
3921 let r = is_type_structurally_recursive(cx, sp, &mut seen, ty);
3922 debug!("is_type_representable: {:?} is {:?}",
3923 ::util::ppaux::ty_to_string(cx, ty), r);
3927 pub fn type_is_trait(ty: Ty) -> bool {
3928 type_trait_info(ty).is_some()
3931 pub fn type_trait_info<'tcx>(ty: Ty<'tcx>) -> Option<&'tcx TyTrait<'tcx>> {
3933 ty_uniq(ty) | ty_rptr(_, mt { ty, ..}) | ty_ptr(mt { ty, ..}) => match ty.sty {
3934 ty_trait(ref t) => Some(&**t),
3937 ty_trait(ref t) => Some(&**t),
3942 pub fn type_is_integral(ty: Ty) -> bool {
3944 ty_infer(IntVar(_)) | ty_int(_) | ty_uint(_) => true,
3949 pub fn type_is_fresh(ty: Ty) -> bool {
3951 ty_infer(FreshTy(_)) => true,
3952 ty_infer(FreshIntTy(_)) => true,
3957 pub fn type_is_uint(ty: Ty) -> bool {
3959 ty_infer(IntVar(_)) | ty_uint(ast::TyUs(_)) => true,
3964 pub fn type_is_char(ty: Ty) -> bool {
3971 pub fn type_is_bare_fn(ty: Ty) -> bool {
3973 ty_bare_fn(..) => true,
3978 pub fn type_is_bare_fn_item(ty: Ty) -> bool {
3980 ty_bare_fn(Some(_), _) => true,
3985 pub fn type_is_fp(ty: Ty) -> bool {
3987 ty_infer(FloatVar(_)) | ty_float(_) => true,
3992 pub fn type_is_numeric(ty: Ty) -> bool {
3993 return type_is_integral(ty) || type_is_fp(ty);
3996 pub fn type_is_signed(ty: Ty) -> bool {
4003 pub fn type_is_machine(ty: Ty) -> bool {
4005 ty_int(ast::TyIs(_)) | ty_uint(ast::TyUs(_)) => false,
4006 ty_int(..) | ty_uint(..) | ty_float(..) => true,
4011 // Whether a type is enum like, that is an enum type with only nullary
4013 pub fn type_is_c_like_enum(cx: &ctxt, ty: Ty) -> bool {
4015 ty_enum(did, _) => {
4016 let variants = enum_variants(cx, did);
4017 if variants.len() == 0 {
4020 variants.iter().all(|v| v.args.len() == 0)
4027 // Returns the type and mutability of *ty.
4029 // The parameter `explicit` indicates if this is an *explicit* dereference.
4030 // Some types---notably unsafe ptrs---can only be dereferenced explicitly.
4031 pub fn deref<'tcx>(ty: Ty<'tcx>, explicit: bool) -> Option<mt<'tcx>> {
4036 mutbl: ast::MutImmutable,
4039 ty_rptr(_, mt) => Some(mt),
4040 ty_ptr(mt) if explicit => Some(mt),
4045 pub fn close_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
4047 ty_open(ty) => mk_rptr(cx, cx.mk_region(ReStatic), mt {ty: ty, mutbl:ast::MutImmutable}),
4048 _ => cx.sess.bug(&format!("Trying to close a non-open type {}",
4049 ty_to_string(cx, ty))[])
4053 pub fn type_content<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
4056 ty_rptr(_, mt) |ty_ptr(mt) => mt.ty,
4061 // Extract the unsized type in an open type (or just return ty if it is not open).
4062 pub fn unopen_type<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
4069 // Returns the type of ty[i]
4070 pub fn index<'tcx>(ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
4072 ty_vec(ty, _) => Some(ty),
4077 // Returns the type of elements contained within an 'array-like' type.
4078 // This is exactly the same as the above, except it supports strings,
4079 // which can't actually be indexed.
4080 pub fn array_element_ty<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
4082 ty_vec(ty, _) => Some(ty),
4083 ty_str => Some(tcx.types.u8),
4088 /// Returns the type of element at index `i` in tuple or tuple-like type `t`.
4089 /// For an enum `t`, `variant` is None only if `t` is a univariant enum.
4090 pub fn positional_element_ty<'tcx>(cx: &ctxt<'tcx>,
4093 variant: Option<ast::DefId>) -> Option<Ty<'tcx>> {
4095 match (&ty.sty, variant) {
4096 (&ty_tup(ref v), None) => v.get(i).map(|&t| t),
4099 (&ty_struct(def_id, substs), None) => lookup_struct_fields(cx, def_id)
4101 .map(|&t|lookup_item_type(cx, t.id).ty.subst(cx, substs)),
4103 (&ty_enum(def_id, substs), Some(variant_def_id)) => {
4104 let variant_info = enum_variant_with_id(cx, def_id, variant_def_id);
4105 variant_info.args.get(i).map(|t|t.subst(cx, substs))
4108 (&ty_enum(def_id, substs), None) => {
4109 assert!(enum_is_univariant(cx, def_id));
4110 let enum_variants = enum_variants(cx, def_id);
4111 let variant_info = &(*enum_variants)[0];
4112 variant_info.args.get(i).map(|t|t.subst(cx, substs))
4119 /// Returns the type of element at field `n` in struct or struct-like type `t`.
4120 /// For an enum `t`, `variant` must be some def id.
4121 pub fn named_element_ty<'tcx>(cx: &ctxt<'tcx>,
4124 variant: Option<ast::DefId>) -> Option<Ty<'tcx>> {
4126 match (&ty.sty, variant) {
4127 (&ty_struct(def_id, substs), None) => {
4128 let r = lookup_struct_fields(cx, def_id);
4129 r.iter().find(|f| f.name == n)
4130 .map(|&f| lookup_field_type(cx, def_id, f.id, substs))
4132 (&ty_enum(def_id, substs), Some(variant_def_id)) => {
4133 let variant_info = enum_variant_with_id(cx, def_id, variant_def_id);
4134 variant_info.arg_names.as_ref()
4135 .expect("must have struct enum variant if accessing a named fields")
4136 .iter().zip(variant_info.args.iter())
4137 .find(|&(ident, _)| ident.name == n)
4138 .map(|(_ident, arg_t)| arg_t.subst(cx, substs))
4144 pub fn node_id_to_trait_ref<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId)
4145 -> Rc<ty::TraitRef<'tcx>> {
4146 match cx.trait_refs.borrow().get(&id) {
4147 Some(ty) => ty.clone(),
4148 None => cx.sess.bug(
4149 &format!("node_id_to_trait_ref: no trait ref for node `{}`",
4150 cx.map.node_to_string(id))[])
4154 pub fn node_id_to_type<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Ty<'tcx> {
4155 match node_id_to_type_opt(cx, id) {
4157 None => cx.sess.bug(
4158 &format!("node_id_to_type: no type for node `{}`",
4159 cx.map.node_to_string(id))[])
4163 pub fn node_id_to_type_opt<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Option<Ty<'tcx>> {
4164 match cx.node_types.borrow().get(&id) {
4165 Some(&ty) => Some(ty),
4170 pub fn node_id_item_substs<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> ItemSubsts<'tcx> {
4171 match cx.item_substs.borrow().get(&id) {
4172 None => ItemSubsts::empty(),
4173 Some(ts) => ts.clone(),
4177 pub fn fn_is_variadic(fty: Ty) -> bool {
4179 ty_bare_fn(_, ref f) => f.sig.0.variadic,
4181 panic!("fn_is_variadic() called on non-fn type: {:?}", s)
4186 pub fn ty_fn_sig<'tcx>(fty: Ty<'tcx>) -> &'tcx PolyFnSig<'tcx> {
4188 ty_bare_fn(_, ref f) => &f.sig,
4190 panic!("ty_fn_sig() called on non-fn type: {:?}", s)
4195 /// Returns the ABI of the given function.
4196 pub fn ty_fn_abi(fty: Ty) -> abi::Abi {
4198 ty_bare_fn(_, ref f) => f.abi,
4199 _ => panic!("ty_fn_abi() called on non-fn type"),
4203 // Type accessors for substructures of types
4204 pub fn ty_fn_args<'tcx>(fty: Ty<'tcx>) -> ty::Binder<Vec<Ty<'tcx>>> {
4205 ty_fn_sig(fty).inputs()
4208 pub fn ty_closure_store(fty: Ty) -> TraitStore {
4210 ty_unboxed_closure(..) => {
4211 // Close enough for the purposes of all the callers of this
4212 // function (which is soon to be deprecated anyhow).
4216 panic!("ty_closure_store() called on non-closure type: {:?}", s)
4221 pub fn ty_fn_ret<'tcx>(fty: Ty<'tcx>) -> Binder<FnOutput<'tcx>> {
4223 ty_bare_fn(_, ref f) => f.sig.output(),
4225 panic!("ty_fn_ret() called on non-fn type: {:?}", s)
4230 pub fn is_fn_ty(fty: Ty) -> bool {
4232 ty_bare_fn(..) => true,
4237 pub fn ty_region(tcx: &ctxt,
4241 ty_rptr(r, _) => *r,
4245 &format!("ty_region() invoked on an inappropriate ty: {:?}",
4251 pub fn free_region_from_def(free_id: ast::NodeId, def: &RegionParameterDef)
4254 ty::ReFree(ty::FreeRegion { scope: region::CodeExtent::from_node_id(free_id),
4255 bound_region: ty::BrNamed(def.def_id,
4259 // Returns the type of a pattern as a monotype. Like @expr_ty, this function
4260 // doesn't provide type parameter substitutions.
4261 pub fn pat_ty<'tcx>(cx: &ctxt<'tcx>, pat: &ast::Pat) -> Ty<'tcx> {
4262 return node_id_to_type(cx, pat.id);
4266 // Returns the type of an expression as a monotype.
4268 // NB (1): This is the PRE-ADJUSTMENT TYPE for the expression. That is, in
4269 // some cases, we insert `AutoAdjustment` annotations such as auto-deref or
4270 // auto-ref. The type returned by this function does not consider such
4271 // adjustments. See `expr_ty_adjusted()` instead.
4273 // NB (2): This type doesn't provide type parameter substitutions; e.g. if you
4274 // ask for the type of "id" in "id(3)", it will return "fn(&int) -> int"
4275 // instead of "fn(ty) -> T with T = int".
4276 pub fn expr_ty<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Ty<'tcx> {
4277 return node_id_to_type(cx, expr.id);
4280 pub fn expr_ty_opt<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Option<Ty<'tcx>> {
4281 return node_id_to_type_opt(cx, expr.id);
4284 /// Returns the type of `expr`, considering any `AutoAdjustment`
4285 /// entry recorded for that expression.
4287 /// It would almost certainly be better to store the adjusted ty in with
4288 /// the `AutoAdjustment`, but I opted not to do this because it would
4289 /// require serializing and deserializing the type and, although that's not
4290 /// hard to do, I just hate that code so much I didn't want to touch it
4291 /// unless it was to fix it properly, which seemed a distraction from the
4292 /// task at hand! -nmatsakis
4293 pub fn expr_ty_adjusted<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Ty<'tcx> {
4294 adjust_ty(cx, expr.span, expr.id, expr_ty(cx, expr),
4295 cx.adjustments.borrow().get(&expr.id),
4296 |method_call| cx.method_map.borrow().get(&method_call).map(|method| method.ty))
4299 pub fn expr_span(cx: &ctxt, id: NodeId) -> Span {
4300 match cx.map.find(id) {
4301 Some(ast_map::NodeExpr(e)) => {
4305 cx.sess.bug(&format!("Node id {} is not an expr: {:?}",
4310 cx.sess.bug(&format!("Node id {} is not present \
4311 in the node map", id)[]);
4316 pub fn local_var_name_str(cx: &ctxt, id: NodeId) -> InternedString {
4317 match cx.map.find(id) {
4318 Some(ast_map::NodeLocal(pat)) => {
4320 ast::PatIdent(_, ref path1, _) => {
4321 token::get_ident(path1.node)
4325 &format!("Variable id {} maps to {:?}, not local",
4332 cx.sess.bug(&format!("Variable id {} maps to {:?}, not local",
4339 /// See `expr_ty_adjusted`
4340 pub fn adjust_ty<'tcx, F>(cx: &ctxt<'tcx>,
4342 expr_id: ast::NodeId,
4343 unadjusted_ty: Ty<'tcx>,
4344 adjustment: Option<&AutoAdjustment<'tcx>>,
4347 F: FnMut(MethodCall) -> Option<Ty<'tcx>>,
4349 if let ty_err = unadjusted_ty.sty {
4350 return unadjusted_ty;
4353 return match adjustment {
4354 Some(adjustment) => {
4356 AdjustReifyFnPointer(_) => {
4357 match unadjusted_ty.sty {
4358 ty::ty_bare_fn(Some(_), b) => {
4359 ty::mk_bare_fn(cx, None, b)
4363 &format!("AdjustReifyFnPointer adjustment on non-fn-item: \
4370 AdjustDerefRef(ref adj) => {
4371 let mut adjusted_ty = unadjusted_ty;
4373 if !ty::type_is_error(adjusted_ty) {
4374 for i in range(0, adj.autoderefs) {
4375 let method_call = MethodCall::autoderef(expr_id, i);
4376 match method_type(method_call) {
4377 Some(method_ty) => {
4378 // overloaded deref operators have all late-bound
4379 // regions fully instantiated and coverge
4381 ty::assert_no_late_bound_regions(cx,
4382 &ty_fn_ret(method_ty));
4383 adjusted_ty = fn_ret.unwrap();
4387 match deref(adjusted_ty, true) {
4388 Some(mt) => { adjusted_ty = mt.ty; }
4392 &format!("the {}th autoderef failed: \
4395 ty_to_string(cx, adjusted_ty))
4402 adjust_ty_for_autoref(cx, span, adjusted_ty, adj.autoref.as_ref())
4406 None => unadjusted_ty
4410 pub fn adjust_ty_for_autoref<'tcx>(cx: &ctxt<'tcx>,
4413 autoref: Option<&AutoRef<'tcx>>)
4419 Some(&AutoPtr(r, 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_rptr(cx, cx.mk_region(r), mt {
4430 Some(&AutoUnsafe(m, ref a)) => {
4431 let adjusted_ty = match a {
4432 &Some(box ref a) => adjust_ty_for_autoref(cx, span, ty, Some(a)),
4435 mk_ptr(cx, mt {ty: adjusted_ty, mutbl: m})
4438 Some(&AutoUnsize(ref k)) => unsize_ty(cx, ty, k, span),
4440 Some(&AutoUnsizeUniq(ref k)) => ty::mk_uniq(cx, unsize_ty(cx, ty, k, span)),
4444 // Take a sized type and a sizing adjustment and produce an unsized version of
4446 pub fn unsize_ty<'tcx>(cx: &ctxt<'tcx>,
4448 kind: &UnsizeKind<'tcx>,
4452 &UnsizeLength(len) => match ty.sty {
4453 ty_vec(ty, Some(n)) => {
4455 mk_vec(cx, ty, None)
4457 _ => cx.sess.span_bug(span,
4458 &format!("UnsizeLength with bad sty: {:?}",
4459 ty_to_string(cx, ty))[])
4461 &UnsizeStruct(box ref k, tp_index) => match ty.sty {
4462 ty_struct(did, substs) => {
4463 let ty_substs = substs.types.get_slice(subst::TypeSpace);
4464 let new_ty = unsize_ty(cx, ty_substs[tp_index], k, span);
4465 let mut unsized_substs = substs.clone();
4466 unsized_substs.types.get_mut_slice(subst::TypeSpace)[tp_index] = new_ty;
4467 mk_struct(cx, did, cx.mk_substs(unsized_substs))
4469 _ => cx.sess.span_bug(span,
4470 &format!("UnsizeStruct with bad sty: {:?}",
4471 ty_to_string(cx, ty))[])
4473 &UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
4474 mk_trait(cx, principal.clone(), bounds.clone())
4479 pub fn resolve_expr(tcx: &ctxt, expr: &ast::Expr) -> def::Def {
4480 match tcx.def_map.borrow().get(&expr.id) {
4483 tcx.sess.span_bug(expr.span, &format!(
4484 "no def-map entry for expr {}", expr.id)[]);
4489 pub fn expr_is_lval(tcx: &ctxt, e: &ast::Expr) -> bool {
4490 match expr_kind(tcx, e) {
4492 RvalueDpsExpr | RvalueDatumExpr | RvalueStmtExpr => false
4496 /// We categorize expressions into three kinds. The distinction between
4497 /// lvalue/rvalue is fundamental to the language. The distinction between the
4498 /// two kinds of rvalues is an artifact of trans which reflects how we will
4499 /// generate code for that kind of expression. See trans/expr.rs for more
4509 pub fn expr_kind(tcx: &ctxt, expr: &ast::Expr) -> ExprKind {
4510 if tcx.method_map.borrow().contains_key(&MethodCall::expr(expr.id)) {
4511 // Overloaded operations are generally calls, and hence they are
4512 // generated via DPS, but there are a few exceptions:
4513 return match expr.node {
4514 // `a += b` has a unit result.
4515 ast::ExprAssignOp(..) => RvalueStmtExpr,
4517 // the deref method invoked for `*a` always yields an `&T`
4518 ast::ExprUnary(ast::UnDeref, _) => LvalueExpr,
4520 // the index method invoked for `a[i]` always yields an `&T`
4521 ast::ExprIndex(..) => LvalueExpr,
4523 // `for` loops are statements
4524 ast::ExprForLoop(..) => RvalueStmtExpr,
4526 // in the general case, result could be any type, use DPS
4532 ast::ExprPath(_) | ast::ExprQPath(_) => {
4533 match resolve_expr(tcx, expr) {
4534 def::DefVariant(tid, vid, _) => {
4535 let variant_info = enum_variant_with_id(tcx, tid, vid);
4536 if variant_info.args.len() > 0u {
4545 def::DefStruct(_) => {
4546 match tcx.node_types.borrow().get(&expr.id) {
4547 Some(ty) => match ty.sty {
4548 ty_bare_fn(..) => RvalueDatumExpr,
4551 // See ExprCast below for why types might be missing.
4552 None => RvalueDatumExpr
4556 // Special case: A unit like struct's constructor must be called without () at the
4557 // end (like `UnitStruct`) which means this is an ExprPath to a DefFn. But in case
4558 // of unit structs this is should not be interpreted as function pointer but as
4559 // call to the constructor.
4560 def::DefFn(_, true) => RvalueDpsExpr,
4562 // Fn pointers are just scalar values.
4563 def::DefFn(..) | def::DefStaticMethod(..) | def::DefMethod(..) => RvalueDatumExpr,
4565 // Note: there is actually a good case to be made that
4566 // DefArg's, particularly those of immediate type, ought to
4567 // considered rvalues.
4568 def::DefStatic(..) |
4570 def::DefLocal(..) => LvalueExpr,
4572 def::DefConst(..) => RvalueDatumExpr,
4577 &format!("uncategorized def for expr {}: {:?}",
4584 ast::ExprUnary(ast::UnDeref, _) |
4585 ast::ExprField(..) |
4586 ast::ExprTupField(..) |
4587 ast::ExprIndex(..) => {
4592 ast::ExprMethodCall(..) |
4593 ast::ExprStruct(..) |
4594 ast::ExprRange(..) |
4597 ast::ExprMatch(..) |
4598 ast::ExprClosure(..) |
4599 ast::ExprBlock(..) |
4600 ast::ExprRepeat(..) |
4601 ast::ExprVec(..) => {
4605 ast::ExprIfLet(..) => {
4606 tcx.sess.span_bug(expr.span, "non-desugared ExprIfLet");
4608 ast::ExprWhileLet(..) => {
4609 tcx.sess.span_bug(expr.span, "non-desugared ExprWhileLet");
4612 ast::ExprLit(ref lit) if lit_is_str(&**lit) => {
4616 ast::ExprCast(..) => {
4617 match tcx.node_types.borrow().get(&expr.id) {
4619 if type_is_trait(ty) {
4626 // Technically, it should not happen that the expr is not
4627 // present within the table. However, it DOES happen
4628 // during type check, because the final types from the
4629 // expressions are not yet recorded in the tcx. At that
4630 // time, though, we are only interested in knowing lvalue
4631 // vs rvalue. It would be better to base this decision on
4632 // the AST type in cast node---but (at the time of this
4633 // writing) it's not easy to distinguish casts to traits
4634 // from other casts based on the AST. This should be
4635 // easier in the future, when casts to traits
4636 // would like @Foo, Box<Foo>, or &Foo.
4642 ast::ExprBreak(..) |
4643 ast::ExprAgain(..) |
4645 ast::ExprWhile(..) |
4647 ast::ExprAssign(..) |
4648 ast::ExprInlineAsm(..) |
4649 ast::ExprAssignOp(..) |
4650 ast::ExprForLoop(..) => {
4654 ast::ExprLit(_) | // Note: LitStr is carved out above
4655 ast::ExprUnary(..) |
4656 ast::ExprBox(None, _) |
4657 ast::ExprAddrOf(..) |
4658 ast::ExprBinary(..) => {
4662 ast::ExprBox(Some(ref place), _) => {
4663 // Special case `Box<T>` for now:
4664 let definition = match tcx.def_map.borrow().get(&place.id) {
4666 None => panic!("no def for place"),
4668 let def_id = definition.def_id();
4669 if tcx.lang_items.exchange_heap() == Some(def_id) {
4676 ast::ExprParen(ref e) => expr_kind(tcx, &**e),
4678 ast::ExprMac(..) => {
4681 "macro expression remains after expansion");
4686 pub fn stmt_node_id(s: &ast::Stmt) -> ast::NodeId {
4688 ast::StmtDecl(_, id) | StmtExpr(_, id) | StmtSemi(_, id) => {
4691 ast::StmtMac(..) => panic!("unexpanded macro in trans")
4695 pub fn field_idx_strict(tcx: &ctxt, name: ast::Name, fields: &[field])
4698 for f in fields.iter() { if f.name == name { return i; } i += 1u; }
4699 tcx.sess.bug(&format!(
4700 "no field named `{}` found in the list of fields `{:?}`",
4701 token::get_name(name),
4703 .map(|f| token::get_name(f.name).get().to_string())
4704 .collect::<Vec<String>>())[]);
4707 pub fn impl_or_trait_item_idx(id: ast::Name, trait_items: &[ImplOrTraitItem])
4709 trait_items.iter().position(|m| m.name() == id)
4712 pub fn ty_sort_string<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> String {
4714 ty_bool | ty_char | ty_int(_) |
4715 ty_uint(_) | ty_float(_) | ty_str => {
4716 ::util::ppaux::ty_to_string(cx, ty)
4718 ty_tup(ref tys) if tys.is_empty() => ::util::ppaux::ty_to_string(cx, ty),
4720 ty_enum(id, _) => format!("enum `{}`", item_path_str(cx, id)),
4721 ty_uniq(_) => "box".to_string(),
4722 ty_vec(_, Some(n)) => format!("array of {} elements", n),
4723 ty_vec(_, None) => "slice".to_string(),
4724 ty_ptr(_) => "*-ptr".to_string(),
4725 ty_rptr(_, _) => "&-ptr".to_string(),
4726 ty_bare_fn(Some(_), _) => format!("fn item"),
4727 ty_bare_fn(None, _) => "fn pointer".to_string(),
4728 ty_trait(ref inner) => {
4729 format!("trait {}", item_path_str(cx, inner.principal_def_id()))
4731 ty_struct(id, _) => {
4732 format!("struct `{}`", item_path_str(cx, id))
4734 ty_unboxed_closure(..) => "closure".to_string(),
4735 ty_tup(_) => "tuple".to_string(),
4736 ty_infer(TyVar(_)) => "inferred type".to_string(),
4737 ty_infer(IntVar(_)) => "integral variable".to_string(),
4738 ty_infer(FloatVar(_)) => "floating-point variable".to_string(),
4739 ty_infer(FreshTy(_)) => "skolemized type".to_string(),
4740 ty_infer(FreshIntTy(_)) => "skolemized integral type".to_string(),
4741 ty_projection(_) => "associated type".to_string(),
4742 ty_param(ref p) => {
4743 if p.space == subst::SelfSpace {
4746 "type parameter".to_string()
4749 ty_err => "type error".to_string(),
4750 ty_open(_) => "opened DST".to_string(),
4754 impl<'tcx> Repr<'tcx> for ty::type_err<'tcx> {
4755 fn repr(&self, tcx: &ty::ctxt<'tcx>) -> String {
4756 ty::type_err_to_str(tcx, self)
4760 /// Explains the source of a type err in a short, human readable way. This is meant to be placed
4761 /// in parentheses after some larger message. You should also invoke `note_and_explain_type_err()`
4762 /// afterwards to present additional details, particularly when it comes to lifetime-related
4764 pub fn type_err_to_str<'tcx>(cx: &ctxt<'tcx>, err: &type_err<'tcx>) -> String {
4765 fn tstore_to_closure(s: &TraitStore) -> String {
4767 &UniqTraitStore => "proc".to_string(),
4768 &RegionTraitStore(..) => "closure".to_string()
4773 terr_cyclic_ty => "cyclic type of infinite size".to_string(),
4774 terr_mismatch => "types differ".to_string(),
4775 terr_unsafety_mismatch(values) => {
4776 format!("expected {} fn, found {} fn",
4780 terr_abi_mismatch(values) => {
4781 format!("expected {} fn, found {} fn",
4785 terr_onceness_mismatch(values) => {
4786 format!("expected {} fn, found {} fn",
4790 terr_sigil_mismatch(values) => {
4791 format!("expected {}, found {}",
4792 tstore_to_closure(&values.expected),
4793 tstore_to_closure(&values.found))
4795 terr_mutability => "values differ in mutability".to_string(),
4796 terr_box_mutability => {
4797 "boxed values differ in mutability".to_string()
4799 terr_vec_mutability => "vectors differ in mutability".to_string(),
4800 terr_ptr_mutability => "pointers differ in mutability".to_string(),
4801 terr_ref_mutability => "references differ in mutability".to_string(),
4802 terr_ty_param_size(values) => {
4803 format!("expected a type with {} type params, \
4804 found one with {} type params",
4808 terr_fixed_array_size(values) => {
4809 format!("expected an array with a fixed size of {} elements, \
4810 found one with {} elements",
4814 terr_tuple_size(values) => {
4815 format!("expected a tuple with {} elements, \
4816 found one with {} elements",
4821 "incorrect number of function parameters".to_string()
4823 terr_regions_does_not_outlive(..) => {
4824 "lifetime mismatch".to_string()
4826 terr_regions_not_same(..) => {
4827 "lifetimes are not the same".to_string()
4829 terr_regions_no_overlap(..) => {
4830 "lifetimes do not intersect".to_string()
4832 terr_regions_insufficiently_polymorphic(br, _) => {
4833 format!("expected bound lifetime parameter {}, \
4834 found concrete lifetime",
4835 bound_region_ptr_to_string(cx, br))
4837 terr_regions_overly_polymorphic(br, _) => {
4838 format!("expected concrete lifetime, \
4839 found bound lifetime parameter {}",
4840 bound_region_ptr_to_string(cx, br))
4842 terr_trait_stores_differ(_, ref values) => {
4843 format!("trait storage differs: expected `{}`, found `{}`",
4844 trait_store_to_string(cx, (*values).expected),
4845 trait_store_to_string(cx, (*values).found))
4847 terr_sorts(values) => {
4848 // A naive approach to making sure that we're not reporting silly errors such as:
4849 // (expected closure, found closure).
4850 let expected_str = ty_sort_string(cx, values.expected);
4851 let found_str = ty_sort_string(cx, values.found);
4852 if expected_str == found_str {
4853 format!("expected {}, found a different {}", expected_str, found_str)
4855 format!("expected {}, found {}", expected_str, found_str)
4858 terr_traits(values) => {
4859 format!("expected trait `{}`, found trait `{}`",
4860 item_path_str(cx, values.expected),
4861 item_path_str(cx, values.found))
4863 terr_builtin_bounds(values) => {
4864 if values.expected.is_empty() {
4865 format!("expected no bounds, found `{}`",
4866 values.found.user_string(cx))
4867 } else if values.found.is_empty() {
4868 format!("expected bounds `{}`, found no bounds",
4869 values.expected.user_string(cx))
4871 format!("expected bounds `{}`, found bounds `{}`",
4872 values.expected.user_string(cx),
4873 values.found.user_string(cx))
4876 terr_integer_as_char => {
4877 "expected an integral type, found `char`".to_string()
4879 terr_int_mismatch(ref values) => {
4880 format!("expected `{:?}`, found `{:?}`",
4884 terr_float_mismatch(ref values) => {
4885 format!("expected `{:?}`, found `{:?}`",
4889 terr_variadic_mismatch(ref values) => {
4890 format!("expected {} fn, found {} function",
4891 if values.expected { "variadic" } else { "non-variadic" },
4892 if values.found { "variadic" } else { "non-variadic" })
4894 terr_convergence_mismatch(ref values) => {
4895 format!("expected {} fn, found {} function",
4896 if values.expected { "converging" } else { "diverging" },
4897 if values.found { "converging" } else { "diverging" })
4899 terr_projection_name_mismatched(ref values) => {
4900 format!("expected {}, found {}",
4901 token::get_name(values.expected),
4902 token::get_name(values.found))
4904 terr_projection_bounds_length(ref values) => {
4905 format!("expected {} associated type bindings, found {}",
4912 pub fn note_and_explain_type_err(cx: &ctxt, err: &type_err) {
4914 terr_regions_does_not_outlive(subregion, superregion) => {
4915 note_and_explain_region(cx, "", subregion, "...");
4916 note_and_explain_region(cx, "...does not necessarily outlive ",
4919 terr_regions_not_same(region1, region2) => {
4920 note_and_explain_region(cx, "", region1, "...");
4921 note_and_explain_region(cx, "...is not the same lifetime as ",
4924 terr_regions_no_overlap(region1, region2) => {
4925 note_and_explain_region(cx, "", region1, "...");
4926 note_and_explain_region(cx, "...does not overlap ",
4929 terr_regions_insufficiently_polymorphic(_, conc_region) => {
4930 note_and_explain_region(cx,
4931 "concrete lifetime that was found is ",
4934 terr_regions_overly_polymorphic(_, ty::ReInfer(ty::ReVar(_))) => {
4935 // don't bother to print out the message below for
4936 // inference variables, it's not very illuminating.
4938 terr_regions_overly_polymorphic(_, conc_region) => {
4939 note_and_explain_region(cx,
4940 "expected concrete lifetime is ",
4947 pub fn provided_source(cx: &ctxt, id: ast::DefId) -> Option<ast::DefId> {
4948 cx.provided_method_sources.borrow().get(&id).map(|x| *x)
4951 pub fn provided_trait_methods<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
4952 -> Vec<Rc<Method<'tcx>>> {
4954 match cx.map.find(id.node) {
4955 Some(ast_map::NodeItem(item)) => {
4957 ItemTrait(_, _, _, ref ms) => {
4959 ast_util::split_trait_methods(&ms[]);
4962 match impl_or_trait_item(
4964 ast_util::local_def(m.id)) {
4965 MethodTraitItem(m) => m,
4966 TypeTraitItem(_) => {
4967 cx.sess.bug("provided_trait_methods(): \
4968 split_trait_methods() put \
4969 associated types in the \
4970 provided method bucket?!")
4976 cx.sess.bug(&format!("provided_trait_methods: `{:?}` is \
4983 cx.sess.bug(&format!("provided_trait_methods: `{:?}` is not a \
4989 csearch::get_provided_trait_methods(cx, id)
4993 /// Helper for looking things up in the various maps that are populated during
4994 /// typeck::collect (e.g., `cx.impl_or_trait_items`, `cx.tcache`, etc). All of
4995 /// these share the pattern that if the id is local, it should have been loaded
4996 /// into the map by the `typeck::collect` phase. If the def-id is external,
4997 /// then we have to go consult the crate loading code (and cache the result for
4999 fn lookup_locally_or_in_crate_store<V, F>(descr: &str,
5001 map: &mut DefIdMap<V>,
5002 load_external: F) -> V where
5006 match map.get(&def_id).cloned() {
5007 Some(v) => { return v; }
5011 if def_id.krate == ast::LOCAL_CRATE {
5012 panic!("No def'n found for {:?} in tcx.{}", def_id, descr);
5014 let v = load_external();
5015 map.insert(def_id, v.clone());
5019 pub fn trait_item<'tcx>(cx: &ctxt<'tcx>, trait_did: ast::DefId, idx: uint)
5020 -> ImplOrTraitItem<'tcx> {
5021 let method_def_id = (*ty::trait_item_def_ids(cx, trait_did))[idx].def_id();
5022 impl_or_trait_item(cx, method_def_id)
5025 pub fn trait_items<'tcx>(cx: &ctxt<'tcx>, trait_did: ast::DefId)
5026 -> Rc<Vec<ImplOrTraitItem<'tcx>>> {
5027 let mut trait_items = cx.trait_items_cache.borrow_mut();
5028 match trait_items.get(&trait_did).cloned() {
5029 Some(trait_items) => trait_items,
5031 let def_ids = ty::trait_item_def_ids(cx, trait_did);
5032 let items: Rc<Vec<ImplOrTraitItem>> =
5033 Rc::new(def_ids.iter()
5034 .map(|d| impl_or_trait_item(cx, d.def_id()))
5036 trait_items.insert(trait_did, items.clone());
5042 pub fn trait_impl_polarity<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5043 -> Option<ast::ImplPolarity> {
5044 if id.krate == ast::LOCAL_CRATE {
5045 match cx.map.find(id.node) {
5046 Some(ast_map::NodeItem(item)) => {
5048 ast::ItemImpl(_, polarity, _, _, _, _) => Some(polarity),
5055 csearch::get_impl_polarity(cx, id)
5059 pub fn impl_or_trait_item<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5060 -> ImplOrTraitItem<'tcx> {
5061 lookup_locally_or_in_crate_store("impl_or_trait_items",
5063 &mut *cx.impl_or_trait_items
5066 csearch::get_impl_or_trait_item(cx, id)
5070 /// Returns true if the given ID refers to an associated type and false if it
5071 /// refers to anything else.
5072 pub fn is_associated_type(cx: &ctxt, id: ast::DefId) -> bool {
5073 memoized(&cx.associated_types, id, |id: ast::DefId| {
5074 if id.krate == ast::LOCAL_CRATE {
5075 match cx.impl_or_trait_items.borrow().get(&id) {
5078 TypeTraitItem(_) => true,
5079 MethodTraitItem(_) => false,
5085 csearch::is_associated_type(&cx.sess.cstore, id)
5090 /// Returns the parameter index that the given associated type corresponds to.
5091 pub fn associated_type_parameter_index(cx: &ctxt,
5092 trait_def: &TraitDef,
5093 associated_type_id: ast::DefId)
5095 for type_parameter_def in trait_def.generics.types.iter() {
5096 if type_parameter_def.def_id == associated_type_id {
5097 return type_parameter_def.index as uint
5100 cx.sess.bug("couldn't find associated type parameter index")
5103 #[derive(Copy, PartialEq, Eq)]
5104 pub struct AssociatedTypeInfo {
5105 pub def_id: ast::DefId,
5107 pub name: ast::Name,
5110 impl PartialOrd for AssociatedTypeInfo {
5111 fn partial_cmp(&self, other: &AssociatedTypeInfo) -> Option<Ordering> {
5112 Some(self.index.cmp(&other.index))
5116 impl Ord for AssociatedTypeInfo {
5117 fn cmp(&self, other: &AssociatedTypeInfo) -> Ordering {
5118 self.index.cmp(&other.index)
5122 pub fn trait_item_def_ids(cx: &ctxt, id: ast::DefId)
5123 -> Rc<Vec<ImplOrTraitItemId>> {
5124 lookup_locally_or_in_crate_store("trait_item_def_ids",
5126 &mut *cx.trait_item_def_ids.borrow_mut(),
5128 Rc::new(csearch::get_trait_item_def_ids(&cx.sess.cstore, id))
5132 pub fn impl_trait_ref<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5133 -> Option<Rc<TraitRef<'tcx>>> {
5134 memoized(&cx.impl_trait_cache, id, |id: ast::DefId| {
5135 if id.krate == ast::LOCAL_CRATE {
5136 debug!("(impl_trait_ref) searching for trait impl {:?}", id);
5137 match cx.map.find(id.node) {
5138 Some(ast_map::NodeItem(item)) => {
5140 ast::ItemImpl(_, _, _, ref opt_trait, _, _) => {
5143 let trait_ref = ty::node_id_to_trait_ref(cx, t.ref_id);
5155 csearch::get_impl_trait(cx, id)
5160 pub fn trait_ref_to_def_id(tcx: &ctxt, tr: &ast::TraitRef) -> ast::DefId {
5161 let def = *tcx.def_map.borrow()
5163 .expect("no def-map entry for trait");
5167 pub fn try_add_builtin_trait(
5169 trait_def_id: ast::DefId,
5170 builtin_bounds: &mut EnumSet<BuiltinBound>)
5173 //! Checks whether `trait_ref` refers to one of the builtin
5174 //! traits, like `Send`, and adds the corresponding
5175 //! bound to the set `builtin_bounds` if so. Returns true if `trait_ref`
5176 //! is a builtin trait.
5178 match tcx.lang_items.to_builtin_kind(trait_def_id) {
5179 Some(bound) => { builtin_bounds.insert(bound); true }
5184 pub fn ty_to_def_id(ty: Ty) -> Option<ast::DefId> {
5187 Some(tt.principal_def_id()),
5190 ty_unboxed_closure(id, _, _) =>
5199 pub struct VariantInfo<'tcx> {
5200 pub args: Vec<Ty<'tcx>>,
5201 pub arg_names: Option<Vec<ast::Ident>>,
5202 pub ctor_ty: Option<Ty<'tcx>>,
5203 pub name: ast::Name,
5209 impl<'tcx> VariantInfo<'tcx> {
5211 /// Creates a new VariantInfo from the corresponding ast representation.
5213 /// Does not do any caching of the value in the type context.
5214 pub fn from_ast_variant(cx: &ctxt<'tcx>,
5215 ast_variant: &ast::Variant,
5216 discriminant: Disr) -> VariantInfo<'tcx> {
5217 let ctor_ty = node_id_to_type(cx, ast_variant.node.id);
5219 match ast_variant.node.kind {
5220 ast::TupleVariantKind(ref args) => {
5221 let arg_tys = if args.len() > 0 {
5222 // the regions in the argument types come from the
5223 // enum def'n, and hence will all be early bound
5224 ty::assert_no_late_bound_regions(cx, &ty_fn_args(ctor_ty))
5229 return VariantInfo {
5232 ctor_ty: Some(ctor_ty),
5233 name: ast_variant.node.name.name,
5234 id: ast_util::local_def(ast_variant.node.id),
5235 disr_val: discriminant,
5236 vis: ast_variant.node.vis
5239 ast::StructVariantKind(ref struct_def) => {
5240 let fields: &[StructField] = &struct_def.fields[];
5242 assert!(fields.len() > 0);
5244 let arg_tys = struct_def.fields.iter()
5245 .map(|field| node_id_to_type(cx, field.node.id)).collect();
5246 let arg_names = fields.iter().map(|field| {
5247 match field.node.kind {
5248 NamedField(ident, _) => ident,
5249 UnnamedField(..) => cx.sess.bug(
5250 "enum_variants: all fields in struct must have a name")
5254 return VariantInfo {
5256 arg_names: Some(arg_names),
5258 name: ast_variant.node.name.name,
5259 id: ast_util::local_def(ast_variant.node.id),
5260 disr_val: discriminant,
5261 vis: ast_variant.node.vis
5268 pub fn substd_enum_variants<'tcx>(cx: &ctxt<'tcx>,
5270 substs: &Substs<'tcx>)
5271 -> Vec<Rc<VariantInfo<'tcx>>> {
5272 enum_variants(cx, id).iter().map(|variant_info| {
5273 let substd_args = variant_info.args.iter()
5274 .map(|aty| aty.subst(cx, substs)).collect::<Vec<_>>();
5276 let substd_ctor_ty = variant_info.ctor_ty.subst(cx, substs);
5278 Rc::new(VariantInfo {
5280 ctor_ty: substd_ctor_ty,
5281 ..(**variant_info).clone()
5286 pub fn item_path_str(cx: &ctxt, id: ast::DefId) -> String {
5287 with_path(cx, id, |path| ast_map::path_to_string(path)).to_string()
5293 TraitDtor(DefId, bool)
5297 pub fn is_present(&self) -> bool {
5299 TraitDtor(..) => true,
5304 pub fn has_drop_flag(&self) -> bool {
5307 &TraitDtor(_, flag) => flag
5312 /* If struct_id names a struct with a dtor, return Some(the dtor's id).
5313 Otherwise return none. */
5314 pub fn ty_dtor(cx: &ctxt, struct_id: DefId) -> DtorKind {
5315 match cx.destructor_for_type.borrow().get(&struct_id) {
5316 Some(&method_def_id) => {
5317 let flag = !has_attr(cx, struct_id, "unsafe_no_drop_flag");
5319 TraitDtor(method_def_id, flag)
5325 pub fn has_dtor(cx: &ctxt, struct_id: DefId) -> bool {
5326 cx.destructor_for_type.borrow().contains_key(&struct_id)
5329 pub fn with_path<T, F>(cx: &ctxt, id: ast::DefId, f: F) -> T where
5330 F: FnOnce(ast_map::PathElems) -> T,
5332 if id.krate == ast::LOCAL_CRATE {
5333 cx.map.with_path(id.node, f)
5335 f(ast_map::Values(csearch::get_item_path(cx, id).iter()).chain(None))
5339 pub fn enum_is_univariant(cx: &ctxt, id: ast::DefId) -> bool {
5340 enum_variants(cx, id).len() == 1
5343 pub fn type_is_empty(cx: &ctxt, ty: Ty) -> bool {
5345 ty_enum(did, _) => (*enum_variants(cx, did)).is_empty(),
5350 pub fn enum_variants<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5351 -> Rc<Vec<Rc<VariantInfo<'tcx>>>> {
5352 memoized(&cx.enum_var_cache, id, |id: ast::DefId| {
5353 if ast::LOCAL_CRATE != id.krate {
5354 Rc::new(csearch::get_enum_variants(cx, id))
5357 Although both this code and check_enum_variants in typeck/check
5358 call eval_const_expr, it should never get called twice for the same
5359 expr, since check_enum_variants also updates the enum_var_cache
5361 match cx.map.get(id.node) {
5362 ast_map::NodeItem(ref item) => {
5364 ast::ItemEnum(ref enum_definition, _) => {
5365 let mut last_discriminant: Option<Disr> = None;
5366 Rc::new(enum_definition.variants.iter().map(|variant| {
5368 let mut discriminant = match last_discriminant {
5369 Some(val) => val + 1,
5370 None => INITIAL_DISCRIMINANT_VALUE
5373 match variant.node.disr_expr {
5375 match const_eval::eval_const_expr_partial(cx, &**e) {
5376 Ok(const_eval::const_int(val)) => {
5377 discriminant = val as Disr
5379 Ok(const_eval::const_uint(val)) => {
5380 discriminant = val as Disr
5385 "expected signed integer constant");
5390 &format!("expected constant: {}",
5397 last_discriminant = Some(discriminant);
5398 Rc::new(VariantInfo::from_ast_variant(cx, &**variant,
5403 cx.sess.bug("enum_variants: id not bound to an enum")
5407 _ => cx.sess.bug("enum_variants: id not bound to an enum")
5413 // Returns information about the enum variant with the given ID:
5414 pub fn enum_variant_with_id<'tcx>(cx: &ctxt<'tcx>,
5415 enum_id: ast::DefId,
5416 variant_id: ast::DefId)
5417 -> Rc<VariantInfo<'tcx>> {
5418 enum_variants(cx, enum_id).iter()
5419 .find(|variant| variant.id == variant_id)
5420 .expect("enum_variant_with_id(): no variant exists with that ID")
5425 // If the given item is in an external crate, looks up its type and adds it to
5426 // the type cache. Returns the type parameters and type.
5427 pub fn lookup_item_type<'tcx>(cx: &ctxt<'tcx>,
5429 -> TypeScheme<'tcx> {
5430 lookup_locally_or_in_crate_store(
5431 "tcache", did, &mut *cx.tcache.borrow_mut(),
5432 || csearch::get_type(cx, did))
5435 /// Given the did of a trait, returns its canonical trait ref.
5436 pub fn lookup_trait_def<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId)
5437 -> Rc<ty::TraitDef<'tcx>> {
5438 memoized(&cx.trait_defs, did, |did: DefId| {
5439 assert!(did.krate != ast::LOCAL_CRATE);
5440 Rc::new(csearch::get_trait_def(cx, did))
5444 /// Given a reference to a trait, returns the "superbounds" declared
5445 /// on the trait, with appropriate substitutions applied. Basically,
5446 /// this applies a filter to the where clauses on the trait, returning
5447 /// those that have the form:
5449 /// Self : SuperTrait<...>
5451 pub fn predicates_for_trait_ref<'tcx>(tcx: &ctxt<'tcx>,
5452 trait_ref: &PolyTraitRef<'tcx>)
5453 -> Vec<ty::Predicate<'tcx>>
5455 let trait_def = lookup_trait_def(tcx, trait_ref.def_id());
5457 debug!("bounds_for_trait_ref(trait_def={:?}, trait_ref={:?})",
5458 trait_def.repr(tcx), trait_ref.repr(tcx));
5460 // The interaction between HRTB and supertraits is not entirely
5461 // obvious. Let me walk you (and myself) through an example.
5463 // Let's start with an easy case. Consider two traits:
5465 // trait Foo<'a> : Bar<'a,'a> { }
5466 // trait Bar<'b,'c> { }
5468 // Now, if we have a trait reference `for<'x> T : Foo<'x>`, then
5469 // we can deduce that `for<'x> T : Bar<'x,'x>`. Basically, if we
5470 // knew that `Foo<'x>` (for any 'x) then we also know that
5471 // `Bar<'x,'x>` (for any 'x). This more-or-less falls out from
5472 // normal substitution.
5474 // In terms of why this is sound, the idea is that whenever there
5475 // is an impl of `T:Foo<'a>`, it must show that `T:Bar<'a,'a>`
5476 // holds. So if there is an impl of `T:Foo<'a>` that applies to
5477 // all `'a`, then we must know that `T:Bar<'a,'a>` holds for all
5480 // Another example to be careful of is this:
5482 // trait Foo1<'a> : for<'b> Bar1<'a,'b> { }
5483 // trait Bar1<'b,'c> { }
5485 // Here, if we have `for<'x> T : Foo1<'x>`, then what do we know?
5486 // The answer is that we know `for<'x,'b> T : Bar1<'x,'b>`. The
5487 // reason is similar to the previous example: any impl of
5488 // `T:Foo1<'x>` must show that `for<'b> T : Bar1<'x, 'b>`. So
5489 // basically we would want to collapse the bound lifetimes from
5490 // the input (`trait_ref`) and the supertraits.
5492 // To achieve this in practice is fairly straightforward. Let's
5493 // consider the more complicated scenario:
5495 // - We start out with `for<'x> T : Foo1<'x>`. In this case, `'x`
5496 // has a De Bruijn index of 1. We want to produce `for<'x,'b> T : Bar1<'x,'b>`,
5497 // where both `'x` and `'b` would have a DB index of 1.
5498 // The substitution from the input trait-ref is therefore going to be
5499 // `'a => 'x` (where `'x` has a DB index of 1).
5500 // - The super-trait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an
5501 // early-bound parameter and `'b' is a late-bound parameter with a
5503 // - If we replace `'a` with `'x` from the input, it too will have
5504 // a DB index of 1, and thus we'll have `for<'x,'b> Bar1<'x,'b>`
5505 // just as we wanted.
5507 // There is only one catch. If we just apply the substitution `'a
5508 // => 'x` to `for<'b> Bar1<'a,'b>`, the substitution code will
5509 // adjust the DB index because we substituting into a binder (it
5510 // tries to be so smart...) resulting in `for<'x> for<'b>
5511 // Bar1<'x,'b>` (we have no syntax for this, so use your
5512 // imagination). Basically the 'x will have DB index of 2 and 'b
5513 // will have DB index of 1. Not quite what we want. So we apply
5514 // the substitution to the *contents* of the trait reference,
5515 // rather than the trait reference itself (put another way, the
5516 // substitution code expects equal binding levels in the values
5517 // from the substitution and the value being substituted into, and
5518 // this trick achieves that).
5520 // Carefully avoid the binder introduced by each trait-ref by
5521 // substituting over the substs, not the trait-refs themselves,
5522 // thus achieving the "collapse" described in the big comment
5524 let trait_bounds: Vec<_> =
5525 trait_def.bounds.trait_bounds
5527 .map(|poly_trait_ref| ty::Binder(poly_trait_ref.0.subst(tcx, trait_ref.substs())))
5530 let projection_bounds: Vec<_> =
5531 trait_def.bounds.projection_bounds
5533 .map(|poly_proj| ty::Binder(poly_proj.0.subst(tcx, trait_ref.substs())))
5536 debug!("bounds_for_trait_ref: trait_bounds={} projection_bounds={}",
5537 trait_bounds.repr(tcx),
5538 projection_bounds.repr(tcx));
5540 // The region bounds and builtin bounds do not currently introduce
5541 // binders so we can just substitute in a straightforward way here.
5543 trait_def.bounds.region_bounds.subst(tcx, trait_ref.substs());
5544 let builtin_bounds =
5545 trait_def.bounds.builtin_bounds.subst(tcx, trait_ref.substs());
5547 let bounds = ty::ParamBounds {
5548 trait_bounds: trait_bounds,
5549 region_bounds: region_bounds,
5550 builtin_bounds: builtin_bounds,
5551 projection_bounds: projection_bounds,
5554 predicates(tcx, trait_ref.self_ty(), &bounds)
5557 pub fn predicates<'tcx>(
5560 bounds: &ParamBounds<'tcx>)
5561 -> Vec<Predicate<'tcx>>
5563 let mut vec = Vec::new();
5565 for builtin_bound in bounds.builtin_bounds.iter() {
5566 match traits::trait_ref_for_builtin_bound(tcx, builtin_bound, param_ty) {
5567 Ok(trait_ref) => { vec.push(trait_ref.as_predicate()); }
5568 Err(ErrorReported) => { }
5572 for ®ion_bound in bounds.region_bounds.iter() {
5573 // account for the binder being introduced below; no need to shift `param_ty`
5574 // because, at present at least, it can only refer to early-bound regions
5575 let region_bound = ty_fold::shift_region(region_bound, 1);
5576 vec.push(ty::Binder(ty::OutlivesPredicate(param_ty, region_bound)).as_predicate());
5579 for bound_trait_ref in bounds.trait_bounds.iter() {
5580 vec.push(bound_trait_ref.as_predicate());
5583 for projection in bounds.projection_bounds.iter() {
5584 vec.push(projection.as_predicate());
5590 /// Get the attributes of a definition.
5591 pub fn get_attrs<'tcx>(tcx: &'tcx ctxt, did: DefId)
5592 -> CowVec<'tcx, ast::Attribute> {
5594 let item = tcx.map.expect_item(did.node);
5595 Cow::Borrowed(&item.attrs[])
5597 Cow::Owned(csearch::get_item_attrs(&tcx.sess.cstore, did))
5601 /// Determine whether an item is annotated with an attribute
5602 pub fn has_attr(tcx: &ctxt, did: DefId, attr: &str) -> bool {
5603 get_attrs(tcx, did).iter().any(|item| item.check_name(attr))
5606 /// Determine whether an item is annotated with `#[repr(packed)]`
5607 pub fn lookup_packed(tcx: &ctxt, did: DefId) -> bool {
5608 lookup_repr_hints(tcx, did).contains(&attr::ReprPacked)
5611 /// Determine whether an item is annotated with `#[simd]`
5612 pub fn lookup_simd(tcx: &ctxt, did: DefId) -> bool {
5613 has_attr(tcx, did, "simd")
5616 /// Obtain the representation annotation for a struct definition.
5617 pub fn lookup_repr_hints(tcx: &ctxt, did: DefId) -> Rc<Vec<attr::ReprAttr>> {
5618 memoized(&tcx.repr_hint_cache, did, |did: DefId| {
5619 Rc::new(if did.krate == LOCAL_CRATE {
5620 get_attrs(tcx, did).iter().flat_map(|meta| {
5621 attr::find_repr_attrs(tcx.sess.diagnostic(), meta).into_iter()
5624 csearch::get_repr_attrs(&tcx.sess.cstore, did)
5629 // Look up a field ID, whether or not it's local
5630 // Takes a list of type substs in case the struct is generic
5631 pub fn lookup_field_type<'tcx>(tcx: &ctxt<'tcx>,
5634 substs: &Substs<'tcx>)
5636 let ty = if id.krate == ast::LOCAL_CRATE {
5637 node_id_to_type(tcx, id.node)
5639 let mut tcache = tcx.tcache.borrow_mut();
5640 let pty = tcache.entry(id).get().unwrap_or_else(
5641 |vacant_entry| vacant_entry.insert(csearch::get_field_type(tcx, struct_id, id)));
5644 ty.subst(tcx, substs)
5647 // Look up the list of field names and IDs for a given struct.
5648 // Panics if the id is not bound to a struct.
5649 pub fn lookup_struct_fields(cx: &ctxt, did: ast::DefId) -> Vec<field_ty> {
5650 if did.krate == ast::LOCAL_CRATE {
5651 let struct_fields = cx.struct_fields.borrow();
5652 match struct_fields.get(&did) {
5653 Some(fields) => (**fields).clone(),
5656 &format!("ID not mapped to struct fields: {}",
5657 cx.map.node_to_string(did.node))[]);
5661 csearch::get_struct_fields(&cx.sess.cstore, did)
5665 pub fn is_tuple_struct(cx: &ctxt, did: ast::DefId) -> bool {
5666 let fields = lookup_struct_fields(cx, did);
5667 !fields.is_empty() && fields.iter().all(|f| f.name == token::special_names::unnamed_field)
5670 // Returns a list of fields corresponding to the struct's items. trans uses
5671 // this. Takes a list of substs with which to instantiate field types.
5672 pub fn struct_fields<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId, substs: &Substs<'tcx>)
5673 -> Vec<field<'tcx>> {
5674 lookup_struct_fields(cx, did).iter().map(|f| {
5678 ty: lookup_field_type(cx, did, f.id, substs),
5685 // Returns a list of fields corresponding to the tuple's items. trans uses
5687 pub fn tup_fields<'tcx>(v: &[Ty<'tcx>]) -> Vec<field<'tcx>> {
5688 v.iter().enumerate().map(|(i, &f)| {
5690 name: token::intern(&i.to_string()[]),
5699 #[derive(Copy, Clone)]
5700 pub struct UnboxedClosureUpvar<'tcx> {
5706 // Returns a list of `UnboxedClosureUpvar`s for each upvar.
5707 pub fn unboxed_closure_upvars<'tcx>(typer: &mc::Typer<'tcx>,
5708 closure_id: ast::DefId,
5709 substs: &Substs<'tcx>)
5710 -> Option<Vec<UnboxedClosureUpvar<'tcx>>>
5712 // Presently an unboxed closure type cannot "escape" out of a
5713 // function, so we will only encounter ones that originated in the
5714 // local crate or were inlined into it along with some function.
5715 // This may change if abstract return types of some sort are
5717 assert!(closure_id.krate == ast::LOCAL_CRATE);
5718 let tcx = typer.tcx();
5719 let capture_mode = tcx.capture_modes.borrow()[closure_id.node].clone();
5720 match tcx.freevars.borrow().get(&closure_id.node) {
5721 None => Some(vec![]),
5722 Some(ref freevars) => {
5725 let freevar_def_id = freevar.def.def_id();
5726 let freevar_ty = match typer.node_ty(freevar_def_id.node) {
5728 Err(()) => { return None; }
5730 let freevar_ty = freevar_ty.subst(tcx, substs);
5732 match capture_mode {
5733 ast::CaptureByValue => {
5734 Some(UnboxedClosureUpvar { def: freevar.def,
5739 ast::CaptureByRef => {
5740 let upvar_id = ty::UpvarId {
5741 var_id: freevar_def_id.node,
5742 closure_expr_id: closure_id.node
5746 let freevar_ref_ty = match typer.upvar_borrow(upvar_id) {
5749 tcx.mk_region(borrow.region),
5752 mutbl: borrow.kind.to_mutbl_lossy(),
5756 // FIXME(#16640) we should really return None here;
5757 // but that requires better inference integration,
5758 // for now gin up something.
5762 Some(UnboxedClosureUpvar {
5775 pub fn is_binopable<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>, op: ast::BinOp) -> bool {
5776 #![allow(non_upper_case_globals)]
5777 static tycat_other: int = 0;
5778 static tycat_bool: int = 1;
5779 static tycat_char: int = 2;
5780 static tycat_int: int = 3;
5781 static tycat_float: int = 4;
5782 static tycat_raw_ptr: int = 6;
5784 static opcat_add: int = 0;
5785 static opcat_sub: int = 1;
5786 static opcat_mult: int = 2;
5787 static opcat_shift: int = 3;
5788 static opcat_rel: int = 4;
5789 static opcat_eq: int = 5;
5790 static opcat_bit: int = 6;
5791 static opcat_logic: int = 7;
5792 static opcat_mod: int = 8;
5794 fn opcat(op: ast::BinOp) -> int {
5796 ast::BiAdd => opcat_add,
5797 ast::BiSub => opcat_sub,
5798 ast::BiMul => opcat_mult,
5799 ast::BiDiv => opcat_mult,
5800 ast::BiRem => opcat_mod,
5801 ast::BiAnd => opcat_logic,
5802 ast::BiOr => opcat_logic,
5803 ast::BiBitXor => opcat_bit,
5804 ast::BiBitAnd => opcat_bit,
5805 ast::BiBitOr => opcat_bit,
5806 ast::BiShl => opcat_shift,
5807 ast::BiShr => opcat_shift,
5808 ast::BiEq => opcat_eq,
5809 ast::BiNe => opcat_eq,
5810 ast::BiLt => opcat_rel,
5811 ast::BiLe => opcat_rel,
5812 ast::BiGe => opcat_rel,
5813 ast::BiGt => opcat_rel
5817 fn tycat<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> int {
5818 if type_is_simd(cx, ty) {
5819 return tycat(cx, simd_type(cx, ty))
5822 ty_char => tycat_char,
5823 ty_bool => tycat_bool,
5824 ty_int(_) | ty_uint(_) | ty_infer(IntVar(_)) => tycat_int,
5825 ty_float(_) | ty_infer(FloatVar(_)) => tycat_float,
5826 ty_ptr(_) => tycat_raw_ptr,
5831 static t: bool = true;
5832 static f: bool = false;
5835 // +, -, *, shift, rel, ==, bit, logic, mod
5836 /*other*/ [f, f, f, f, f, f, f, f, f],
5837 /*bool*/ [f, f, f, f, t, t, t, t, f],
5838 /*char*/ [f, f, f, f, t, t, f, f, f],
5839 /*int*/ [t, t, t, t, t, t, t, f, t],
5840 /*float*/ [t, t, t, f, t, t, f, f, f],
5841 /*bot*/ [t, t, t, t, t, t, t, t, t],
5842 /*raw ptr*/ [f, f, f, f, t, t, f, f, f]];
5844 return tbl[tycat(cx, ty) as uint ][opcat(op) as uint];
5847 // Returns the repeat count for a repeating vector expression.
5848 pub fn eval_repeat_count(tcx: &ctxt, count_expr: &ast::Expr) -> uint {
5849 match const_eval::eval_const_expr_partial(tcx, count_expr) {
5851 let found = match val {
5852 const_eval::const_uint(count) => return count as uint,
5853 const_eval::const_int(count) if count >= 0 => return count as uint,
5854 const_eval::const_int(_) =>
5856 const_eval::const_float(_) =>
5858 const_eval::const_str(_) =>
5860 const_eval::const_bool(_) =>
5862 const_eval::const_binary(_) =>
5865 tcx.sess.span_err(count_expr.span, &format!(
5866 "expected positive integer for repeat count, found {}",
5870 let found = match count_expr.node {
5871 ast::ExprPath(ast::Path {
5875 }) if segments.len() == 1 =>
5878 "non-constant expression"
5880 tcx.sess.span_err(count_expr.span, &format!(
5881 "expected constant integer for repeat count, found {}",
5888 // Iterate over a type parameter's bounded traits and any supertraits
5889 // of those traits, ignoring kinds.
5890 // Here, the supertraits are the transitive closure of the supertrait
5891 // relation on the supertraits from each bounded trait's constraint
5893 pub fn each_bound_trait_and_supertraits<'tcx, F>(tcx: &ctxt<'tcx>,
5894 bounds: &[PolyTraitRef<'tcx>],
5897 F: FnMut(PolyTraitRef<'tcx>) -> bool,
5899 for bound_trait_ref in traits::transitive_bounds(tcx, bounds) {
5900 if !f(bound_trait_ref) {
5907 pub fn object_region_bounds<'tcx>(
5909 opt_principal: Option<&PolyTraitRef<'tcx>>, // None for closures
5910 others: BuiltinBounds)
5913 // Since we don't actually *know* the self type for an object,
5914 // this "open(err)" serves as a kind of dummy standin -- basically
5915 // a skolemized type.
5916 let open_ty = ty::mk_infer(tcx, FreshTy(0));
5918 let opt_trait_ref = opt_principal.map_or(Vec::new(), |principal| {
5919 // Note that we preserve the overall binding levels here.
5920 assert!(!open_ty.has_escaping_regions());
5921 let substs = tcx.mk_substs(principal.0.substs.with_self_ty(open_ty));
5922 vec!(ty::Binder(Rc::new(ty::TraitRef::new(principal.0.def_id, substs))))
5925 let param_bounds = ty::ParamBounds {
5926 region_bounds: Vec::new(),
5927 builtin_bounds: others,
5928 trait_bounds: opt_trait_ref,
5929 projection_bounds: Vec::new(), // not relevant to computing region bounds
5932 let predicates = ty::predicates(tcx, open_ty, ¶m_bounds);
5933 ty::required_region_bounds(tcx, open_ty, predicates)
5936 /// Given a set of predicates that apply to an object type, returns
5937 /// the region bounds that the (erased) `Self` type must
5938 /// outlive. Precisely *because* the `Self` type is erased, the
5939 /// parameter `erased_self_ty` must be supplied to indicate what type
5940 /// has been used to represent `Self` in the predicates
5941 /// themselves. This should really be a unique type; `FreshTy(0)` is a
5942 /// popular choice (see `object_region_bounds` above).
5944 /// Requires that trait definitions have been processed so that we can
5945 /// elaborate predicates and walk supertraits.
5946 pub fn required_region_bounds<'tcx>(tcx: &ctxt<'tcx>,
5947 erased_self_ty: Ty<'tcx>,
5948 predicates: Vec<ty::Predicate<'tcx>>)
5951 debug!("required_region_bounds(erased_self_ty={:?}, predicates={:?})",
5952 erased_self_ty.repr(tcx),
5953 predicates.repr(tcx));
5955 assert!(!erased_self_ty.has_escaping_regions());
5957 traits::elaborate_predicates(tcx, predicates)
5958 .filter_map(|predicate| {
5960 ty::Predicate::Projection(..) |
5961 ty::Predicate::Trait(..) |
5962 ty::Predicate::Equate(..) |
5963 ty::Predicate::RegionOutlives(..) => {
5966 ty::Predicate::TypeOutlives(ty::Binder(ty::OutlivesPredicate(t, r))) => {
5967 // Search for a bound of the form `erased_self_ty
5968 // : 'a`, but be wary of something like `for<'a>
5969 // erased_self_ty : 'a` (we interpret a
5970 // higher-ranked bound like that as 'static,
5971 // though at present the code in `fulfill.rs`
5972 // considers such bounds to be unsatisfiable, so
5973 // it's kind of a moot point since you could never
5974 // construct such an object, but this seems
5975 // correct even if that code changes).
5976 if t == erased_self_ty && !r.has_escaping_regions() {
5977 if r.has_escaping_regions() {
5991 pub fn get_tydesc_ty<'tcx>(tcx: &ctxt<'tcx>) -> Result<Ty<'tcx>, String> {
5992 tcx.lang_items.require(TyDescStructLangItem).map(|tydesc_lang_item| {
5993 tcx.intrinsic_defs.borrow().get(&tydesc_lang_item).cloned()
5994 .expect("Failed to resolve TyDesc")
5998 pub fn item_variances(tcx: &ctxt, item_id: ast::DefId) -> Rc<ItemVariances> {
5999 lookup_locally_or_in_crate_store(
6000 "item_variance_map", item_id, &mut *tcx.item_variance_map.borrow_mut(),
6001 || Rc::new(csearch::get_item_variances(&tcx.sess.cstore, item_id)))
6004 /// Records a trait-to-implementation mapping.
6005 pub fn record_trait_implementation(tcx: &ctxt,
6006 trait_def_id: DefId,
6007 impl_def_id: DefId) {
6009 let trait_impls = match trait_impl_polarity(tcx, impl_def_id) {
6010 Some(ast::ImplPolarity::Positive) => &tcx.trait_impls,
6011 Some(ast::ImplPolarity::Negative) => &tcx.trait_negative_impls,
6012 _ => tcx.sess.bug(&format!("tried to record a non-impl item with id {:?}",
6016 match trait_impls.borrow().get(&trait_def_id) {
6017 Some(impls_for_trait) => {
6018 impls_for_trait.borrow_mut().push(impl_def_id);
6024 trait_impls.borrow_mut().insert(trait_def_id, Rc::new(RefCell::new(vec!(impl_def_id))));
6027 /// Populates the type context with all the implementations for the given type
6029 pub fn populate_implementations_for_type_if_necessary(tcx: &ctxt,
6030 type_id: ast::DefId) {
6031 if type_id.krate == LOCAL_CRATE {
6034 if tcx.populated_external_types.borrow().contains(&type_id) {
6038 debug!("populate_implementations_for_type_if_necessary: searching for {:?}", type_id);
6040 let mut inherent_impls = Vec::new();
6041 csearch::each_implementation_for_type(&tcx.sess.cstore, type_id,
6043 let impl_items = csearch::get_impl_items(&tcx.sess.cstore, impl_def_id);
6045 // Record the trait->implementation mappings, if applicable.
6046 let associated_traits = csearch::get_impl_trait(tcx, impl_def_id);
6047 for trait_ref in associated_traits.iter() {
6048 record_trait_implementation(tcx, trait_ref.def_id, impl_def_id);
6051 // For any methods that use a default implementation, add them to
6052 // the map. This is a bit unfortunate.
6053 for impl_item_def_id in impl_items.iter() {
6054 let method_def_id = impl_item_def_id.def_id();
6055 match impl_or_trait_item(tcx, method_def_id) {
6056 MethodTraitItem(method) => {
6057 for &source in method.provided_source.iter() {
6058 tcx.provided_method_sources
6060 .insert(method_def_id, source);
6063 TypeTraitItem(_) => {}
6067 // Store the implementation info.
6068 tcx.impl_items.borrow_mut().insert(impl_def_id, impl_items);
6070 // If this is an inherent implementation, record it.
6071 if associated_traits.is_none() {
6072 inherent_impls.push(impl_def_id);
6076 tcx.inherent_impls.borrow_mut().insert(type_id, Rc::new(inherent_impls));
6077 tcx.populated_external_types.borrow_mut().insert(type_id);
6080 /// Populates the type context with all the implementations for the given
6081 /// trait if necessary.
6082 pub fn populate_implementations_for_trait_if_necessary(
6084 trait_id: ast::DefId) {
6085 if trait_id.krate == LOCAL_CRATE {
6088 if tcx.populated_external_traits.borrow().contains(&trait_id) {
6092 csearch::each_implementation_for_trait(&tcx.sess.cstore, trait_id,
6093 |implementation_def_id| {
6094 let impl_items = csearch::get_impl_items(&tcx.sess.cstore, implementation_def_id);
6096 // Record the trait->implementation mapping.
6097 record_trait_implementation(tcx, trait_id, implementation_def_id);
6099 // For any methods that use a default implementation, add them to
6100 // the map. This is a bit unfortunate.
6101 for impl_item_def_id in impl_items.iter() {
6102 let method_def_id = impl_item_def_id.def_id();
6103 match impl_or_trait_item(tcx, method_def_id) {
6104 MethodTraitItem(method) => {
6105 for &source in method.provided_source.iter() {
6106 tcx.provided_method_sources
6108 .insert(method_def_id, source);
6111 TypeTraitItem(_) => {}
6115 // Store the implementation info.
6116 tcx.impl_items.borrow_mut().insert(implementation_def_id, impl_items);
6119 tcx.populated_external_traits.borrow_mut().insert(trait_id);
6122 /// Given the def_id of an impl, return the def_id of the trait it implements.
6123 /// If it implements no trait, return `None`.
6124 pub fn trait_id_of_impl(tcx: &ctxt,
6126 -> Option<ast::DefId> {
6127 ty::impl_trait_ref(tcx, def_id).map(|tr| tr.def_id)
6130 /// If the given def ID describes a method belonging to an impl, return the
6131 /// ID of the impl that the method belongs to. Otherwise, return `None`.
6132 pub fn impl_of_method(tcx: &ctxt, def_id: ast::DefId)
6133 -> Option<ast::DefId> {
6134 if def_id.krate != LOCAL_CRATE {
6135 return match csearch::get_impl_or_trait_item(tcx,
6136 def_id).container() {
6137 TraitContainer(_) => None,
6138 ImplContainer(def_id) => Some(def_id),
6141 match tcx.impl_or_trait_items.borrow().get(&def_id).cloned() {
6142 Some(trait_item) => {
6143 match trait_item.container() {
6144 TraitContainer(_) => None,
6145 ImplContainer(def_id) => Some(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 trait that the method belongs to. Otherwise, return `None`.
6155 pub fn trait_of_item(tcx: &ctxt, def_id: ast::DefId) -> Option<ast::DefId> {
6156 if def_id.krate != LOCAL_CRATE {
6157 return csearch::get_trait_of_item(&tcx.sess.cstore, def_id, tcx);
6159 match tcx.impl_or_trait_items.borrow().get(&def_id).cloned() {
6160 Some(impl_or_trait_item) => {
6161 match impl_or_trait_item.container() {
6162 TraitContainer(def_id) => Some(def_id),
6163 ImplContainer(def_id) => trait_id_of_impl(tcx, def_id),
6170 /// If the given def ID describes an item belonging to a trait, (either a
6171 /// default method or an implementation of a trait method), return the ID of
6172 /// the method inside trait definition (this means that if the given def ID
6173 /// is already that of the original trait method, then the return value is
6175 /// Otherwise, return `None`.
6176 pub fn trait_item_of_item(tcx: &ctxt, def_id: ast::DefId)
6177 -> Option<ImplOrTraitItemId> {
6178 let impl_item = match tcx.impl_or_trait_items.borrow().get(&def_id) {
6179 Some(m) => m.clone(),
6180 None => return None,
6182 let name = impl_item.name();
6183 match trait_of_item(tcx, def_id) {
6184 Some(trait_did) => {
6185 let trait_items = ty::trait_items(tcx, trait_did);
6187 .position(|m| m.name() == name)
6188 .map(|idx| ty::trait_item(tcx, trait_did, idx).id())
6194 /// Creates a hash of the type `Ty` which will be the same no matter what crate
6195 /// context it's calculated within. This is used by the `type_id` intrinsic.
6196 pub fn hash_crate_independent<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>, svh: &Svh) -> u64 {
6197 let mut state = SipHasher::new();
6198 helper(tcx, ty, svh, &mut state);
6199 return state.finish();
6201 fn helper<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>, svh: &Svh,
6202 state: &mut SipHasher) {
6203 macro_rules! byte { ($b:expr) => { ($b as u8).hash(state) } }
6204 macro_rules! hash { ($e:expr) => { $e.hash(state) } }
6206 let region = |&: state: &mut SipHasher, r: Region| {
6209 ReLateBound(db, BrAnon(i)) => {
6219 tcx.sess.bug("unexpected region found when hashing a type")
6223 let did = |&: state: &mut SipHasher, did: DefId| {
6224 let h = if ast_util::is_local(did) {
6227 tcx.sess.cstore.get_crate_hash(did.krate)
6229 h.as_str().hash(state);
6230 did.node.hash(state);
6232 let mt = |&: state: &mut SipHasher, mt: mt| {
6233 mt.mutbl.hash(state);
6235 let fn_sig = |&: state: &mut SipHasher, sig: &Binder<FnSig<'tcx>>| {
6236 let sig = anonymize_late_bound_regions(tcx, sig).0;
6237 for a in sig.inputs.iter() { helper(tcx, *a, svh, state); }
6238 if let ty::FnConverging(output) = sig.output {
6239 helper(tcx, output, svh, state);
6242 maybe_walk_ty(ty, |ty| {
6244 ty_bool => byte!(2),
6245 ty_char => byte!(3),
6268 ty_vec(_, Some(n)) => {
6272 ty_vec(_, None) => {
6284 ty_bare_fn(opt_def_id, ref b) => {
6289 fn_sig(state, &b.sig);
6292 ty_trait(ref data) => {
6294 did(state, data.principal_def_id());
6297 let principal = anonymize_late_bound_regions(tcx, &data.principal).0;
6298 for subty in principal.substs.types.iter() {
6299 helper(tcx, *subty, svh, state);
6304 ty_struct(d, _) => {
6308 ty_tup(ref inner) => {
6316 hash!(token::get_name(p.name));
6318 ty_open(_) => byte!(22),
6319 ty_infer(_) => unreachable!(),
6320 ty_err => byte!(23),
6321 ty_unboxed_closure(d, r, _) => {
6326 ty_projection(ref data) => {
6328 did(state, data.trait_ref.def_id);
6329 hash!(token::get_name(data.item_name));
6338 pub fn to_string(self) -> &'static str {
6341 Contravariant => "-",
6348 /// Construct a parameter environment suitable for static contexts or other contexts where there
6349 /// are no free type/lifetime parameters in scope.
6350 pub fn empty_parameter_environment<'a,'tcx>(cx: &'a ctxt<'tcx>) -> ParameterEnvironment<'a,'tcx> {
6351 ty::ParameterEnvironment { tcx: cx,
6352 free_substs: Substs::empty(),
6353 caller_bounds: GenericBounds::empty(),
6354 implicit_region_bound: ty::ReEmpty,
6355 selection_cache: traits::SelectionCache::new(), }
6358 /// See `ParameterEnvironment` struct def'n for details
6359 pub fn construct_parameter_environment<'a,'tcx>(
6360 tcx: &'a ctxt<'tcx>,
6361 generics: &ty::Generics<'tcx>,
6362 free_id: ast::NodeId)
6363 -> ParameterEnvironment<'a, 'tcx>
6367 // Construct the free substs.
6371 let mut types = VecPerParamSpace::empty();
6372 push_types_from_defs(tcx, &mut types, generics.types.as_slice());
6374 // map bound 'a => free 'a
6375 let mut regions = VecPerParamSpace::empty();
6376 push_region_params(&mut regions, free_id, generics.regions.as_slice());
6378 let free_substs = Substs {
6380 regions: subst::NonerasedRegions(regions)
6383 let free_id_scope = region::CodeExtent::from_node_id(free_id);
6386 // Compute the bounds on Self and the type parameters.
6389 let bounds = generics.to_bounds(tcx, &free_substs);
6390 let bounds = liberate_late_bound_regions(tcx, free_id_scope, &ty::Binder(bounds));
6393 // Compute region bounds. For now, these relations are stored in a
6394 // global table on the tcx, so just enter them there. I'm not
6395 // crazy about this scheme, but it's convenient, at least.
6398 record_region_bounds(tcx, &bounds);
6400 debug!("construct_parameter_environment: free_id={:?} free_subst={:?} bounds={:?}",
6402 free_substs.repr(tcx),
6405 return ty::ParameterEnvironment {
6407 free_substs: free_substs,
6408 implicit_region_bound: ty::ReScope(free_id_scope),
6409 caller_bounds: bounds,
6410 selection_cache: traits::SelectionCache::new(),
6413 fn push_region_params(regions: &mut VecPerParamSpace<ty::Region>,
6414 free_id: ast::NodeId,
6415 region_params: &[RegionParameterDef])
6417 for r in region_params.iter() {
6418 regions.push(r.space, ty::free_region_from_def(free_id, r));
6422 fn push_types_from_defs<'tcx>(tcx: &ty::ctxt<'tcx>,
6423 types: &mut VecPerParamSpace<Ty<'tcx>>,
6424 defs: &[TypeParameterDef<'tcx>]) {
6425 for def in defs.iter() {
6426 debug!("construct_parameter_environment(): push_types_from_defs: def={:?}",
6428 let ty = ty::mk_param_from_def(tcx, def);
6429 types.push(def.space, ty);
6433 fn record_region_bounds<'tcx>(tcx: &ty::ctxt<'tcx>, bounds: &GenericBounds<'tcx>) {
6434 debug!("record_region_bounds(bounds={:?})", bounds.repr(tcx));
6436 for predicate in bounds.predicates.iter() {
6438 Predicate::Projection(..) |
6439 Predicate::Trait(..) |
6440 Predicate::Equate(..) |
6441 Predicate::TypeOutlives(..) => {
6442 // No region bounds here
6444 Predicate::RegionOutlives(ty::Binder(ty::OutlivesPredicate(r_a, r_b))) => {
6446 (ty::ReFree(fr_a), ty::ReFree(fr_b)) => {
6447 // Record that `'a:'b`. Or, put another way, `'b <= 'a`.
6448 tcx.region_maps.relate_free_regions(fr_b, fr_a);
6451 // All named regions are instantiated with free regions.
6453 format!("record_region_bounds: non free region: {} / {}",
6455 r_b.repr(tcx)).as_slice());
6465 pub fn from_mutbl(m: ast::Mutability) -> BorrowKind {
6467 ast::MutMutable => MutBorrow,
6468 ast::MutImmutable => ImmBorrow,
6472 /// Returns a mutability `m` such that an `&m T` pointer could be used to obtain this borrow
6473 /// kind. Because borrow kinds are richer than mutabilities, we sometimes have to pick a
6474 /// mutability that is stronger than necessary so that it at least *would permit* the borrow in
6476 pub fn to_mutbl_lossy(self) -> ast::Mutability {
6478 MutBorrow => ast::MutMutable,
6479 ImmBorrow => ast::MutImmutable,
6481 // We have no type corresponding to a unique imm borrow, so
6482 // use `&mut`. It gives all the capabilities of an `&uniq`
6483 // and hence is a safe "over approximation".
6484 UniqueImmBorrow => ast::MutMutable,
6488 pub fn to_user_str(&self) -> &'static str {
6490 MutBorrow => "mutable",
6491 ImmBorrow => "immutable",
6492 UniqueImmBorrow => "uniquely immutable",
6497 impl<'tcx> ctxt<'tcx> {
6498 pub fn capture_mode(&self, closure_expr_id: ast::NodeId)
6499 -> ast::CaptureClause {
6500 self.capture_modes.borrow()[closure_expr_id].clone()
6503 pub fn is_method_call(&self, expr_id: ast::NodeId) -> bool {
6504 self.method_map.borrow().contains_key(&MethodCall::expr(expr_id))
6508 impl<'a,'tcx> mc::Typer<'tcx> for ParameterEnvironment<'a,'tcx> {
6509 fn tcx(&self) -> &ty::ctxt<'tcx> {
6513 fn node_ty(&self, id: ast::NodeId) -> mc::McResult<Ty<'tcx>> {
6514 Ok(ty::node_id_to_type(self.tcx, id))
6517 fn expr_ty_adjusted(&self, expr: &ast::Expr) -> mc::McResult<Ty<'tcx>> {
6518 Ok(ty::expr_ty_adjusted(self.tcx, expr))
6521 fn node_method_ty(&self, method_call: ty::MethodCall) -> Option<Ty<'tcx>> {
6522 self.tcx.method_map.borrow().get(&method_call).map(|method| method.ty)
6525 fn node_method_origin(&self, method_call: ty::MethodCall)
6526 -> Option<ty::MethodOrigin<'tcx>>
6528 self.tcx.method_map.borrow().get(&method_call).map(|method| method.origin.clone())
6531 fn adjustments(&self) -> &RefCell<NodeMap<ty::AutoAdjustment<'tcx>>> {
6532 &self.tcx.adjustments
6535 fn is_method_call(&self, id: ast::NodeId) -> bool {
6536 self.tcx.is_method_call(id)
6539 fn temporary_scope(&self, rvalue_id: ast::NodeId) -> Option<region::CodeExtent> {
6540 self.tcx.region_maps.temporary_scope(rvalue_id)
6543 fn upvar_borrow(&self, upvar_id: ty::UpvarId) -> Option<ty::UpvarBorrow> {
6544 Some(self.tcx.upvar_borrow_map.borrow()[upvar_id].clone())
6547 fn capture_mode(&self, closure_expr_id: ast::NodeId)
6548 -> ast::CaptureClause {
6549 self.tcx.capture_mode(closure_expr_id)
6552 fn type_moves_by_default(&self, span: Span, ty: Ty<'tcx>) -> bool {
6553 type_moves_by_default(self, span, ty)
6557 impl<'a,'tcx> UnboxedClosureTyper<'tcx> for ty::ParameterEnvironment<'a,'tcx> {
6558 fn param_env<'b>(&'b self) -> &'b ty::ParameterEnvironment<'b,'tcx> {
6562 fn unboxed_closure_kind(&self,
6564 -> ty::UnboxedClosureKind
6566 self.tcx.unboxed_closure_kind(def_id)
6569 fn unboxed_closure_type(&self,
6571 substs: &subst::Substs<'tcx>)
6572 -> ty::ClosureTy<'tcx>
6574 self.tcx.unboxed_closure_type(def_id, substs)
6577 fn unboxed_closure_upvars(&self,
6579 substs: &Substs<'tcx>)
6580 -> Option<Vec<UnboxedClosureUpvar<'tcx>>>
6582 unboxed_closure_upvars(self, def_id, substs)
6587 /// The category of explicit self.
6588 #[derive(Clone, Copy, Eq, PartialEq, Show)]
6589 pub enum ExplicitSelfCategory {
6590 StaticExplicitSelfCategory,
6591 ByValueExplicitSelfCategory,
6592 ByReferenceExplicitSelfCategory(Region, ast::Mutability),
6593 ByBoxExplicitSelfCategory,
6596 /// Pushes all the lifetimes in the given type onto the given list. A
6597 /// "lifetime in a type" is a lifetime specified by a reference or a lifetime
6598 /// in a list of type substitutions. This does *not* traverse into nominal
6599 /// types, nor does it resolve fictitious types.
6600 pub fn accumulate_lifetimes_in_type(accumulator: &mut Vec<ty::Region>,
6604 ty_rptr(region, _) => {
6605 accumulator.push(*region)
6607 ty_trait(ref t) => {
6608 accumulator.push_all(t.principal.0.substs.regions().as_slice());
6610 ty_enum(_, substs) |
6611 ty_struct(_, substs) => {
6612 accum_substs(accumulator, substs);
6614 ty_unboxed_closure(_, region, substs) => {
6615 accumulator.push(*region);
6616 accum_substs(accumulator, substs);
6638 fn accum_substs(accumulator: &mut Vec<Region>, substs: &Substs) {
6639 match substs.regions {
6640 subst::ErasedRegions => {}
6641 subst::NonerasedRegions(ref regions) => {
6642 for region in regions.iter() {
6643 accumulator.push(*region)
6650 /// A free variable referred to in a function.
6651 #[derive(Copy, RustcEncodable, RustcDecodable)]
6652 pub struct Freevar {
6653 /// The variable being accessed free.
6656 // First span where it is accessed (there can be multiple).
6660 pub type FreevarMap = NodeMap<Vec<Freevar>>;
6662 pub type CaptureModeMap = NodeMap<ast::CaptureClause>;
6664 // Trait method resolution
6665 pub type TraitMap = NodeMap<Vec<DefId>>;
6667 // Map from the NodeId of a glob import to a list of items which are actually
6669 pub type GlobMap = HashMap<NodeId, HashSet<Name>>;
6671 pub fn with_freevars<T, F>(tcx: &ty::ctxt, fid: ast::NodeId, f: F) -> T where
6672 F: FnOnce(&[Freevar]) -> T,
6674 match tcx.freevars.borrow().get(&fid) {
6680 impl<'tcx> AutoAdjustment<'tcx> {
6681 pub fn is_identity(&self) -> bool {
6683 AdjustReifyFnPointer(..) => false,
6684 AdjustDerefRef(ref r) => r.is_identity(),
6689 impl<'tcx> AutoDerefRef<'tcx> {
6690 pub fn is_identity(&self) -> bool {
6691 self.autoderefs == 0 && self.autoref.is_none()
6695 /// Replace any late-bound regions bound in `value` with free variants attached to scope-id
6697 pub fn liberate_late_bound_regions<'tcx, T>(
6698 tcx: &ty::ctxt<'tcx>,
6699 scope: region::CodeExtent,
6702 where T : TypeFoldable<'tcx> + Repr<'tcx>
6704 replace_late_bound_regions(
6706 |br| ty::ReFree(ty::FreeRegion{scope: scope, bound_region: br})).0
6709 pub fn count_late_bound_regions<'tcx, T>(
6710 tcx: &ty::ctxt<'tcx>,
6713 where T : TypeFoldable<'tcx> + Repr<'tcx>
6715 let (_, skol_map) = replace_late_bound_regions(tcx, value, |_| ty::ReStatic);
6719 pub fn binds_late_bound_regions<'tcx, T>(
6720 tcx: &ty::ctxt<'tcx>,
6723 where T : TypeFoldable<'tcx> + Repr<'tcx>
6725 count_late_bound_regions(tcx, value) > 0
6728 pub fn assert_no_late_bound_regions<'tcx, T>(
6729 tcx: &ty::ctxt<'tcx>,
6732 where T : TypeFoldable<'tcx> + Repr<'tcx> + Clone
6734 assert!(!binds_late_bound_regions(tcx, value));
6738 /// Replace any late-bound regions bound in `value` with `'static`. Useful in trans but also
6739 /// method lookup and a few other places where precise region relationships are not required.
6740 pub fn erase_late_bound_regions<'tcx, T>(
6741 tcx: &ty::ctxt<'tcx>,
6744 where T : TypeFoldable<'tcx> + Repr<'tcx>
6746 replace_late_bound_regions(tcx, value, |_| ty::ReStatic).0
6749 /// Rewrite any late-bound regions so that they are anonymous. Region numbers are
6750 /// assigned starting at 1 and increasing monotonically in the order traversed
6751 /// by the fold operation.
6753 /// The chief purpose of this function is to canonicalize regions so that two
6754 /// `FnSig`s or `TraitRef`s which are equivalent up to region naming will become
6755 /// structurally identical. For example, `for<'a, 'b> fn(&'a int, &'b int)` and
6756 /// `for<'a, 'b> fn(&'b int, &'a int)` will become identical after anonymization.
6757 pub fn anonymize_late_bound_regions<'tcx, T>(
6761 where T : TypeFoldable<'tcx> + Repr<'tcx>,
6763 let mut counter = 0;
6764 ty::Binder(replace_late_bound_regions(tcx, sig, |_| {
6766 ReLateBound(ty::DebruijnIndex::new(1), BrAnon(counter))
6770 /// Replaces the late-bound-regions in `value` that are bound by `value`.
6771 pub fn replace_late_bound_regions<'tcx, T, F>(
6772 tcx: &ty::ctxt<'tcx>,
6775 -> (T, FnvHashMap<ty::BoundRegion,ty::Region>)
6776 where T : TypeFoldable<'tcx> + Repr<'tcx>,
6777 F : FnMut(BoundRegion) -> ty::Region,
6779 debug!("replace_late_bound_regions({})", binder.repr(tcx));
6781 let mut map = FnvHashMap::new();
6783 // Note: fold the field `0`, not the binder, so that late-bound
6784 // regions bound by `binder` are considered free.
6785 let value = ty_fold::fold_regions(tcx, &binder.0, |region, current_depth| {
6786 debug!("region={}", region.repr(tcx));
6788 ty::ReLateBound(debruijn, br) if debruijn.depth == current_depth => {
6790 * map.entry(br).get().unwrap_or_else(
6791 |vacant_entry| vacant_entry.insert(mapf(br)));
6793 if let ty::ReLateBound(debruijn1, br) = region {
6794 // If the callback returns a late-bound region,
6795 // that region should always use depth 1. Then we
6796 // adjust it to the correct depth.
6797 assert_eq!(debruijn1.depth, 1);
6798 ty::ReLateBound(debruijn, br)
6809 debug!("resulting map: {:?} value: {:?}", map, value.repr(tcx));
6813 impl DebruijnIndex {
6814 pub fn new(depth: u32) -> DebruijnIndex {
6816 DebruijnIndex { depth: depth }
6819 pub fn shifted(&self, amount: u32) -> DebruijnIndex {
6820 DebruijnIndex { depth: self.depth + amount }
6824 impl<'tcx> Repr<'tcx> for AutoAdjustment<'tcx> {
6825 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6827 AdjustReifyFnPointer(def_id) => {
6828 format!("AdjustReifyFnPointer({})", def_id.repr(tcx))
6830 AdjustDerefRef(ref data) => {
6837 impl<'tcx> Repr<'tcx> for UnsizeKind<'tcx> {
6838 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6840 UnsizeLength(n) => format!("UnsizeLength({})", n),
6841 UnsizeStruct(ref k, n) => format!("UnsizeStruct({},{})", k.repr(tcx), n),
6842 UnsizeVtable(ref a, ref b) => format!("UnsizeVtable({},{})", a.repr(tcx), b.repr(tcx)),
6847 impl<'tcx> Repr<'tcx> for AutoDerefRef<'tcx> {
6848 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6849 format!("AutoDerefRef({}, {})", self.autoderefs, self.autoref.repr(tcx))
6853 impl<'tcx> Repr<'tcx> for AutoRef<'tcx> {
6854 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6856 AutoPtr(a, b, ref c) => {
6857 format!("AutoPtr({},{:?},{})", a.repr(tcx), b, c.repr(tcx))
6859 AutoUnsize(ref a) => {
6860 format!("AutoUnsize({})", a.repr(tcx))
6862 AutoUnsizeUniq(ref a) => {
6863 format!("AutoUnsizeUniq({})", a.repr(tcx))
6865 AutoUnsafe(ref a, ref b) => {
6866 format!("AutoUnsafe({:?},{})", a, b.repr(tcx))
6872 impl<'tcx> Repr<'tcx> for TyTrait<'tcx> {
6873 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6874 format!("TyTrait({},{})",
6875 self.principal.repr(tcx),
6876 self.bounds.repr(tcx))
6880 impl<'tcx> Repr<'tcx> for ty::Predicate<'tcx> {
6881 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6883 Predicate::Trait(ref a) => a.repr(tcx),
6884 Predicate::Equate(ref pair) => pair.repr(tcx),
6885 Predicate::RegionOutlives(ref pair) => pair.repr(tcx),
6886 Predicate::TypeOutlives(ref pair) => pair.repr(tcx),
6887 Predicate::Projection(ref pair) => pair.repr(tcx),
6892 impl<'tcx> Repr<'tcx> for vtable_origin<'tcx> {
6893 fn repr(&self, tcx: &ty::ctxt<'tcx>) -> String {
6895 vtable_static(def_id, ref tys, ref vtable_res) => {
6896 format!("vtable_static({:?}:{}, {}, {})",
6898 ty::item_path_str(tcx, def_id),
6900 vtable_res.repr(tcx))
6903 vtable_param(x, y) => {
6904 format!("vtable_param({:?}, {})", x, y)
6907 vtable_unboxed_closure(def_id) => {
6908 format!("vtable_unboxed_closure({:?})", def_id)
6912 format!("vtable_error")
6918 pub fn make_substs_for_receiver_types<'tcx>(tcx: &ty::ctxt<'tcx>,
6919 trait_ref: &ty::TraitRef<'tcx>,
6920 method: &ty::Method<'tcx>)
6921 -> subst::Substs<'tcx>
6924 * Substitutes the values for the receiver's type parameters
6925 * that are found in method, leaving the method's type parameters
6929 let meth_tps: Vec<Ty> =
6930 method.generics.types.get_slice(subst::FnSpace)
6932 .map(|def| ty::mk_param_from_def(tcx, def))
6934 let meth_regions: Vec<ty::Region> =
6935 method.generics.regions.get_slice(subst::FnSpace)
6937 .map(|def| ty::ReEarlyBound(def.def_id.node, def.space,
6938 def.index, def.name))
6940 trait_ref.substs.clone().with_method(meth_tps, meth_regions)
6944 pub enum CopyImplementationError {
6945 FieldDoesNotImplementCopy(ast::Name),
6946 VariantDoesNotImplementCopy(ast::Name),
6951 pub fn can_type_implement_copy<'a,'tcx>(param_env: &ParameterEnvironment<'a, 'tcx>,
6953 self_type: Ty<'tcx>)
6954 -> Result<(),CopyImplementationError>
6956 let tcx = param_env.tcx;
6958 let did = match self_type.sty {
6959 ty::ty_struct(struct_did, substs) => {
6960 let fields = ty::struct_fields(tcx, struct_did, substs);
6961 for field in fields.iter() {
6962 if type_moves_by_default(param_env, span, field.mt.ty) {
6963 return Err(FieldDoesNotImplementCopy(field.name))
6968 ty::ty_enum(enum_did, substs) => {
6969 let enum_variants = ty::enum_variants(tcx, enum_did);
6970 for variant in enum_variants.iter() {
6971 for variant_arg_type in variant.args.iter() {
6972 let substd_arg_type =
6973 variant_arg_type.subst(tcx, substs);
6974 if type_moves_by_default(param_env, span, substd_arg_type) {
6975 return Err(VariantDoesNotImplementCopy(variant.name))
6981 _ => return Err(TypeIsStructural),
6984 if ty::has_dtor(tcx, did) {
6985 return Err(TypeHasDestructor)
6991 // FIXME(#20298) -- all of these types basically walk various
6992 // structures to test whether types/regions are reachable with various
6993 // properties. It should be possible to express them in terms of one
6994 // common "walker" trait or something.
6996 pub trait RegionEscape {
6997 fn has_escaping_regions(&self) -> bool {
6998 self.has_regions_escaping_depth(0)
7001 fn has_regions_escaping_depth(&self, depth: u32) -> bool;
7004 impl<'tcx> RegionEscape for Ty<'tcx> {
7005 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7006 ty::type_escapes_depth(*self, depth)
7010 impl<'tcx> RegionEscape for Substs<'tcx> {
7011 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7012 self.types.has_regions_escaping_depth(depth) ||
7013 self.regions.has_regions_escaping_depth(depth)
7017 impl<'tcx,T:RegionEscape> RegionEscape for VecPerParamSpace<T> {
7018 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7019 self.iter_enumerated().any(|(space, _, t)| {
7020 if space == subst::FnSpace {
7021 t.has_regions_escaping_depth(depth+1)
7023 t.has_regions_escaping_depth(depth)
7029 impl<'tcx> RegionEscape for TypeScheme<'tcx> {
7030 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7031 self.ty.has_regions_escaping_depth(depth) ||
7032 self.generics.has_regions_escaping_depth(depth)
7036 impl RegionEscape for Region {
7037 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7038 self.escapes_depth(depth)
7042 impl<'tcx> RegionEscape for Generics<'tcx> {
7043 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7044 self.predicates.has_regions_escaping_depth(depth)
7048 impl<'tcx> RegionEscape for Predicate<'tcx> {
7049 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7051 Predicate::Trait(ref data) => data.has_regions_escaping_depth(depth),
7052 Predicate::Equate(ref data) => data.has_regions_escaping_depth(depth),
7053 Predicate::RegionOutlives(ref data) => data.has_regions_escaping_depth(depth),
7054 Predicate::TypeOutlives(ref data) => data.has_regions_escaping_depth(depth),
7055 Predicate::Projection(ref data) => data.has_regions_escaping_depth(depth),
7060 impl<'tcx> RegionEscape for TraitRef<'tcx> {
7061 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7062 self.substs.types.iter().any(|t| t.has_regions_escaping_depth(depth)) ||
7063 self.substs.regions.has_regions_escaping_depth(depth)
7067 impl<'tcx> RegionEscape for subst::RegionSubsts {
7068 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7070 subst::ErasedRegions => false,
7071 subst::NonerasedRegions(ref r) => {
7072 r.iter().any(|t| t.has_regions_escaping_depth(depth))
7078 impl<'tcx,T:RegionEscape> RegionEscape for Binder<T> {
7079 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7080 self.0.has_regions_escaping_depth(depth + 1)
7084 impl<'tcx> RegionEscape for EquatePredicate<'tcx> {
7085 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7086 self.0.has_regions_escaping_depth(depth) || self.1.has_regions_escaping_depth(depth)
7090 impl<'tcx> RegionEscape for TraitPredicate<'tcx> {
7091 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7092 self.trait_ref.has_regions_escaping_depth(depth)
7096 impl<T:RegionEscape,U:RegionEscape> RegionEscape for OutlivesPredicate<T,U> {
7097 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7098 self.0.has_regions_escaping_depth(depth) || self.1.has_regions_escaping_depth(depth)
7102 impl<'tcx> RegionEscape for ProjectionPredicate<'tcx> {
7103 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7104 self.projection_ty.has_regions_escaping_depth(depth) ||
7105 self.ty.has_regions_escaping_depth(depth)
7109 impl<'tcx> RegionEscape for ProjectionTy<'tcx> {
7110 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7111 self.trait_ref.has_regions_escaping_depth(depth)
7115 impl<'tcx> Repr<'tcx> for ty::ProjectionPredicate<'tcx> {
7116 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7117 format!("ProjectionPredicate({}, {})",
7118 self.projection_ty.repr(tcx),
7123 pub trait HasProjectionTypes {
7124 fn has_projection_types(&self) -> bool;
7127 impl<'tcx,T:HasProjectionTypes> HasProjectionTypes for Vec<T> {
7128 fn has_projection_types(&self) -> bool {
7129 self.iter().any(|p| p.has_projection_types())
7133 impl<'tcx,T:HasProjectionTypes> HasProjectionTypes for VecPerParamSpace<T> {
7134 fn has_projection_types(&self) -> bool {
7135 self.iter().any(|p| p.has_projection_types())
7139 impl<'tcx> HasProjectionTypes for ClosureTy<'tcx> {
7140 fn has_projection_types(&self) -> bool {
7141 self.sig.has_projection_types()
7145 impl<'tcx> HasProjectionTypes for UnboxedClosureUpvar<'tcx> {
7146 fn has_projection_types(&self) -> bool {
7147 self.ty.has_projection_types()
7151 impl<'tcx> HasProjectionTypes for ty::GenericBounds<'tcx> {
7152 fn has_projection_types(&self) -> bool {
7153 self.predicates.has_projection_types()
7157 impl<'tcx> HasProjectionTypes for Predicate<'tcx> {
7158 fn has_projection_types(&self) -> bool {
7160 Predicate::Trait(ref data) => data.has_projection_types(),
7161 Predicate::Equate(ref data) => data.has_projection_types(),
7162 Predicate::RegionOutlives(ref data) => data.has_projection_types(),
7163 Predicate::TypeOutlives(ref data) => data.has_projection_types(),
7164 Predicate::Projection(ref data) => data.has_projection_types(),
7169 impl<'tcx> HasProjectionTypes for TraitPredicate<'tcx> {
7170 fn has_projection_types(&self) -> bool {
7171 self.trait_ref.has_projection_types()
7175 impl<'tcx> HasProjectionTypes for EquatePredicate<'tcx> {
7176 fn has_projection_types(&self) -> bool {
7177 self.0.has_projection_types() || self.1.has_projection_types()
7181 impl HasProjectionTypes for Region {
7182 fn has_projection_types(&self) -> bool {
7187 impl<T:HasProjectionTypes,U:HasProjectionTypes> HasProjectionTypes for OutlivesPredicate<T,U> {
7188 fn has_projection_types(&self) -> bool {
7189 self.0.has_projection_types() || self.1.has_projection_types()
7193 impl<'tcx> HasProjectionTypes for ProjectionPredicate<'tcx> {
7194 fn has_projection_types(&self) -> bool {
7195 self.projection_ty.has_projection_types() || self.ty.has_projection_types()
7199 impl<'tcx> HasProjectionTypes for ProjectionTy<'tcx> {
7200 fn has_projection_types(&self) -> bool {
7201 self.trait_ref.has_projection_types()
7205 impl<'tcx> HasProjectionTypes for Ty<'tcx> {
7206 fn has_projection_types(&self) -> bool {
7207 ty::type_has_projection(*self)
7211 impl<'tcx> HasProjectionTypes for TraitRef<'tcx> {
7212 fn has_projection_types(&self) -> bool {
7213 self.substs.has_projection_types()
7217 impl<'tcx> HasProjectionTypes for subst::Substs<'tcx> {
7218 fn has_projection_types(&self) -> bool {
7219 self.types.iter().any(|t| t.has_projection_types())
7223 impl<'tcx,T> HasProjectionTypes for Option<T>
7224 where T : HasProjectionTypes
7226 fn has_projection_types(&self) -> bool {
7227 self.iter().any(|t| t.has_projection_types())
7231 impl<'tcx,T> HasProjectionTypes for Rc<T>
7232 where T : HasProjectionTypes
7234 fn has_projection_types(&self) -> bool {
7235 (**self).has_projection_types()
7239 impl<'tcx,T> HasProjectionTypes for Box<T>
7240 where T : HasProjectionTypes
7242 fn has_projection_types(&self) -> bool {
7243 (**self).has_projection_types()
7247 impl<T> HasProjectionTypes for Binder<T>
7248 where T : HasProjectionTypes
7250 fn has_projection_types(&self) -> bool {
7251 self.0.has_projection_types()
7255 impl<'tcx> HasProjectionTypes for FnOutput<'tcx> {
7256 fn has_projection_types(&self) -> bool {
7258 FnConverging(t) => t.has_projection_types(),
7259 FnDiverging => false,
7264 impl<'tcx> HasProjectionTypes for FnSig<'tcx> {
7265 fn has_projection_types(&self) -> bool {
7266 self.inputs.iter().any(|t| t.has_projection_types()) ||
7267 self.output.has_projection_types()
7271 impl<'tcx> HasProjectionTypes for field<'tcx> {
7272 fn has_projection_types(&self) -> bool {
7273 self.mt.ty.has_projection_types()
7277 impl<'tcx> HasProjectionTypes for BareFnTy<'tcx> {
7278 fn has_projection_types(&self) -> bool {
7279 self.sig.has_projection_types()
7283 pub trait ReferencesError {
7284 fn references_error(&self) -> bool;
7287 impl<T:ReferencesError> ReferencesError for Binder<T> {
7288 fn references_error(&self) -> bool {
7289 self.0.references_error()
7293 impl<T:ReferencesError> ReferencesError for Rc<T> {
7294 fn references_error(&self) -> bool {
7295 (&**self).references_error()
7299 impl<'tcx> ReferencesError for TraitPredicate<'tcx> {
7300 fn references_error(&self) -> bool {
7301 self.trait_ref.references_error()
7305 impl<'tcx> ReferencesError for ProjectionPredicate<'tcx> {
7306 fn references_error(&self) -> bool {
7307 self.projection_ty.trait_ref.references_error() || self.ty.references_error()
7311 impl<'tcx> ReferencesError for TraitRef<'tcx> {
7312 fn references_error(&self) -> bool {
7313 self.input_types().iter().any(|t| t.references_error())
7317 impl<'tcx> ReferencesError for Ty<'tcx> {
7318 fn references_error(&self) -> bool {
7319 type_is_error(*self)
7323 impl<'tcx> ReferencesError for Predicate<'tcx> {
7324 fn references_error(&self) -> bool {
7326 Predicate::Trait(ref data) => data.references_error(),
7327 Predicate::Equate(ref data) => data.references_error(),
7328 Predicate::RegionOutlives(ref data) => data.references_error(),
7329 Predicate::TypeOutlives(ref data) => data.references_error(),
7330 Predicate::Projection(ref data) => data.references_error(),
7335 impl<A,B> ReferencesError for OutlivesPredicate<A,B>
7336 where A : ReferencesError, B : ReferencesError
7338 fn references_error(&self) -> bool {
7339 self.0.references_error() || self.1.references_error()
7343 impl<'tcx> ReferencesError for EquatePredicate<'tcx>
7345 fn references_error(&self) -> bool {
7346 self.0.references_error() || self.1.references_error()
7350 impl ReferencesError for Region
7352 fn references_error(&self) -> bool {
7357 impl<'tcx> Repr<'tcx> for ClosureTy<'tcx> {
7358 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7359 format!("ClosureTy({},{},{:?},{},{},{})",
7363 self.bounds.repr(tcx),
7369 impl<'tcx> Repr<'tcx> for UnboxedClosureUpvar<'tcx> {
7370 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7371 format!("UnboxedClosureUpvar({},{})",
7377 impl<'tcx> Repr<'tcx> for field<'tcx> {
7378 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7379 format!("field({},{})",
7380 self.name.repr(tcx),
7385 impl<'a, 'tcx> Repr<'tcx> for ParameterEnvironment<'a, 'tcx> {
7386 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7387 format!("ParameterEnvironment(\
7389 implicit_region_bound={}, \
7391 self.free_substs.repr(tcx),
7392 self.implicit_region_bound.repr(tcx),
7393 self.caller_bounds.repr(tcx))