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;
72 use std::cell::{Cell, RefCell};
73 use std::cmp::{self, Ordering};
74 use std::fmt::{self, Show};
75 use std::hash::{Hash, sip, Writer};
79 use collections::enum_set::{EnumSet, CLike};
80 use std::collections::{HashMap, HashSet};
82 use syntax::ast::{CrateNum, DefId, Ident, ItemTrait, LOCAL_CRATE};
83 use syntax::ast::{MutImmutable, MutMutable, Name, NamedField, NodeId};
84 use syntax::ast::{Onceness, StmtExpr, StmtSemi, StructField, UnnamedField};
85 use syntax::ast::{Visibility};
86 use syntax::ast_util::{self, is_local, lit_is_str, local_def, PostExpansionMethod};
87 use syntax::attr::{self, AttrMetaMethods};
88 use syntax::codemap::Span;
89 use syntax::parse::token::{self, InternedString, special_idents};
90 use syntax::{ast, ast_map};
94 pub const INITIAL_DISCRIMINANT_VALUE: Disr = 0;
98 /// The complete set of all analyses described in this module. This is
99 /// produced by the driver and fed to trans and later passes.
100 pub struct CrateAnalysis<'tcx> {
101 pub export_map: ExportMap,
102 pub exported_items: middle::privacy::ExportedItems,
103 pub public_items: middle::privacy::PublicItems,
104 pub ty_cx: ty::ctxt<'tcx>,
105 pub reachable: NodeSet,
107 pub glob_map: Option<GlobMap>,
110 #[derive(Copy, PartialEq, Eq, Hash)]
111 pub struct field<'tcx> {
116 #[derive(Clone, Copy, Show)]
117 pub enum ImplOrTraitItemContainer {
118 TraitContainer(ast::DefId),
119 ImplContainer(ast::DefId),
122 impl ImplOrTraitItemContainer {
123 pub fn id(&self) -> ast::DefId {
125 TraitContainer(id) => id,
126 ImplContainer(id) => id,
131 #[derive(Clone, Show)]
132 pub enum ImplOrTraitItem<'tcx> {
133 MethodTraitItem(Rc<Method<'tcx>>),
134 TypeTraitItem(Rc<AssociatedType>),
137 impl<'tcx> ImplOrTraitItem<'tcx> {
138 fn id(&self) -> ImplOrTraitItemId {
140 MethodTraitItem(ref method) => MethodTraitItemId(method.def_id),
141 TypeTraitItem(ref associated_type) => {
142 TypeTraitItemId(associated_type.def_id)
147 pub fn def_id(&self) -> ast::DefId {
149 MethodTraitItem(ref method) => method.def_id,
150 TypeTraitItem(ref associated_type) => associated_type.def_id,
154 pub fn name(&self) -> ast::Name {
156 MethodTraitItem(ref method) => method.name,
157 TypeTraitItem(ref associated_type) => associated_type.name,
161 pub fn container(&self) -> ImplOrTraitItemContainer {
163 MethodTraitItem(ref method) => method.container,
164 TypeTraitItem(ref associated_type) => associated_type.container,
168 pub fn as_opt_method(&self) -> Option<Rc<Method<'tcx>>> {
170 MethodTraitItem(ref m) => Some((*m).clone()),
171 TypeTraitItem(_) => None
176 #[derive(Clone, Copy, Show)]
177 pub enum ImplOrTraitItemId {
178 MethodTraitItemId(ast::DefId),
179 TypeTraitItemId(ast::DefId),
182 impl ImplOrTraitItemId {
183 pub fn def_id(&self) -> ast::DefId {
185 MethodTraitItemId(def_id) => def_id,
186 TypeTraitItemId(def_id) => def_id,
191 #[derive(Clone, Show)]
192 pub struct Method<'tcx> {
194 pub generics: ty::Generics<'tcx>,
195 pub fty: BareFnTy<'tcx>,
196 pub explicit_self: ExplicitSelfCategory,
197 pub vis: ast::Visibility,
198 pub def_id: ast::DefId,
199 pub container: ImplOrTraitItemContainer,
201 // If this method is provided, we need to know where it came from
202 pub provided_source: Option<ast::DefId>
205 impl<'tcx> Method<'tcx> {
206 pub fn new(name: ast::Name,
207 generics: ty::Generics<'tcx>,
209 explicit_self: ExplicitSelfCategory,
210 vis: ast::Visibility,
212 container: ImplOrTraitItemContainer,
213 provided_source: Option<ast::DefId>)
219 explicit_self: explicit_self,
222 container: container,
223 provided_source: provided_source
227 pub fn container_id(&self) -> ast::DefId {
228 match self.container {
229 TraitContainer(id) => id,
230 ImplContainer(id) => id,
235 #[derive(Clone, Copy, Show)]
236 pub struct AssociatedType {
238 pub vis: ast::Visibility,
239 pub def_id: ast::DefId,
240 pub container: ImplOrTraitItemContainer,
243 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
244 pub struct mt<'tcx> {
246 pub mutbl: ast::Mutability,
249 #[derive(Clone, Copy, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Show)]
250 pub enum TraitStore {
253 /// &Trait and &mut Trait
254 RegionTraitStore(Region, ast::Mutability),
257 #[derive(Clone, Copy, Show)]
258 pub struct field_ty {
261 pub vis: ast::Visibility,
262 pub origin: ast::DefId, // The DefId of the struct in which the field is declared.
265 // Contains information needed to resolve types and (in the future) look up
266 // the types of AST nodes.
267 #[derive(Copy, PartialEq, Eq, Hash)]
268 pub struct creader_cache_key {
275 pub enum ast_ty_to_ty_cache_entry<'tcx> {
276 atttce_unresolved, /* not resolved yet */
277 atttce_resolved(Ty<'tcx>) /* resolved to a type, irrespective of region */
280 #[derive(Clone, PartialEq, RustcDecodable, RustcEncodable)]
281 pub struct ItemVariances {
282 pub types: VecPerParamSpace<Variance>,
283 pub regions: VecPerParamSpace<Variance>,
286 #[derive(Clone, PartialEq, RustcDecodable, RustcEncodable, Show, Copy)]
288 Covariant, // T<A> <: T<B> iff A <: B -- e.g., function return type
289 Invariant, // T<A> <: T<B> iff B == A -- e.g., type of mutable cell
290 Contravariant, // T<A> <: T<B> iff B <: A -- e.g., function param type
291 Bivariant, // T<A> <: T<B> -- e.g., unused type parameter
294 #[derive(Clone, Show)]
295 pub enum AutoAdjustment<'tcx> {
296 AdjustAddEnv(ast::DefId, ty::TraitStore),
297 AdjustReifyFnPointer(ast::DefId), // go from a fn-item type to a fn-pointer type
298 AdjustDerefRef(AutoDerefRef<'tcx>)
301 #[derive(Clone, PartialEq, Show)]
302 pub enum UnsizeKind<'tcx> {
303 // [T, ..n] -> [T], the uint field is n.
305 // An unsize coercion applied to the tail field of a struct.
306 // The uint is the index of the type parameter which is unsized.
307 UnsizeStruct(Box<UnsizeKind<'tcx>>, uint),
308 UnsizeVtable(TyTrait<'tcx>, /* the self type of the trait */ Ty<'tcx>)
311 #[derive(Clone, Show)]
312 pub struct AutoDerefRef<'tcx> {
313 pub autoderefs: uint,
314 pub autoref: Option<AutoRef<'tcx>>
317 #[derive(Clone, PartialEq, Show)]
318 pub enum AutoRef<'tcx> {
319 /// Convert from T to &T
320 /// The third field allows us to wrap other AutoRef adjustments.
321 AutoPtr(Region, ast::Mutability, Option<Box<AutoRef<'tcx>>>),
323 /// Convert [T, ..n] to [T] (or similar, depending on the kind)
324 AutoUnsize(UnsizeKind<'tcx>),
326 /// Convert Box<[T, ..n]> to Box<[T]> or something similar in a Box.
327 /// With DST and Box a library type, this should be replaced by UnsizeStruct.
328 AutoUnsizeUniq(UnsizeKind<'tcx>),
330 /// Convert from T to *T
331 /// Value to thin pointer
332 /// The second field allows us to wrap other AutoRef adjustments.
333 AutoUnsafe(ast::Mutability, Option<Box<AutoRef<'tcx>>>),
336 // Ugly little helper function. The first bool in the returned tuple is true if
337 // there is an 'unsize to trait object' adjustment at the bottom of the
338 // adjustment. If that is surrounded by an AutoPtr, then we also return the
339 // region of the AutoPtr (in the third argument). The second bool is true if the
340 // adjustment is unique.
341 fn autoref_object_region(autoref: &AutoRef) -> (bool, bool, Option<Region>) {
342 fn unsize_kind_is_object(k: &UnsizeKind) -> bool {
344 &UnsizeVtable(..) => true,
345 &UnsizeStruct(box ref k, _) => unsize_kind_is_object(k),
351 &AutoUnsize(ref k) => (unsize_kind_is_object(k), false, None),
352 &AutoUnsizeUniq(ref k) => (unsize_kind_is_object(k), true, None),
353 &AutoPtr(adj_r, _, Some(box ref autoref)) => {
354 let (b, u, r) = autoref_object_region(autoref);
355 if r.is_some() || u {
361 &AutoUnsafe(_, Some(box ref autoref)) => autoref_object_region(autoref),
362 _ => (false, false, None)
366 // If the adjustment introduces a borrowed reference to a trait object, then
367 // returns the region of the borrowed reference.
368 pub fn adjusted_object_region(adj: &AutoAdjustment) -> Option<Region> {
370 &AdjustDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
371 let (b, _, r) = autoref_object_region(autoref);
382 // Returns true if there is a trait cast at the bottom of the adjustment.
383 pub fn adjust_is_object(adj: &AutoAdjustment) -> bool {
385 &AdjustDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
386 let (b, _, _) = autoref_object_region(autoref);
393 // If possible, returns the type expected from the given adjustment. This is not
394 // possible if the adjustment depends on the type of the adjusted expression.
395 pub fn type_of_adjust<'tcx>(cx: &ctxt<'tcx>, adj: &AutoAdjustment<'tcx>) -> Option<Ty<'tcx>> {
396 fn type_of_autoref<'tcx>(cx: &ctxt<'tcx>, autoref: &AutoRef<'tcx>) -> Option<Ty<'tcx>> {
398 &AutoUnsize(ref k) => match k {
399 &UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
400 Some(mk_trait(cx, principal.clone(), bounds.clone()))
404 &AutoUnsizeUniq(ref k) => match k {
405 &UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
406 Some(mk_uniq(cx, mk_trait(cx, principal.clone(), bounds.clone())))
410 &AutoPtr(r, m, Some(box ref autoref)) => {
411 match type_of_autoref(cx, autoref) {
412 Some(ty) => Some(mk_rptr(cx, cx.mk_region(r), mt {mutbl: m, ty: ty})),
416 &AutoUnsafe(m, Some(box ref autoref)) => {
417 match type_of_autoref(cx, autoref) {
418 Some(ty) => Some(mk_ptr(cx, mt {mutbl: m, ty: ty})),
427 &AdjustDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
428 type_of_autoref(cx, autoref)
434 #[derive(Clone, Copy, RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Show)]
435 pub struct param_index {
436 pub space: subst::ParamSpace,
440 #[derive(Clone, Show)]
441 pub enum MethodOrigin<'tcx> {
442 // fully statically resolved method
443 MethodStatic(ast::DefId),
445 // fully statically resolved unboxed closure invocation
446 MethodStaticUnboxedClosure(ast::DefId),
448 // method invoked on a type parameter with a bounded trait
449 MethodTypeParam(MethodParam<'tcx>),
451 // method invoked on a trait instance
452 MethodTraitObject(MethodObject<'tcx>),
456 // details for a method invoked with a receiver whose type is a type parameter
457 // with a bounded trait.
458 #[derive(Clone, Show)]
459 pub struct MethodParam<'tcx> {
460 // the precise trait reference that occurs as a bound -- this may
461 // be a supertrait of what the user actually typed. Note that it
462 // never contains bound regions; those regions should have been
463 // instantiated with fresh variables at this point.
464 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
466 // index of uint in the list of methods for the trait
467 pub method_num: uint,
470 // details for a method invoked with a receiver whose type is an object
471 #[derive(Clone, Show)]
472 pub struct MethodObject<'tcx> {
473 // the (super)trait containing the method to be invoked
474 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
476 // the actual base trait id of the object
477 pub object_trait_id: ast::DefId,
479 // index of the method to be invoked amongst the trait's methods
480 pub method_num: uint,
482 // index into the actual runtime vtable.
483 // the vtable is formed by concatenating together the method lists of
484 // the base object trait and all supertraits; this is the index into
486 pub real_index: uint,
490 pub struct MethodCallee<'tcx> {
491 pub origin: MethodOrigin<'tcx>,
493 pub substs: subst::Substs<'tcx>
496 /// With method calls, we store some extra information in
497 /// side tables (i.e method_map). We use
498 /// MethodCall as a key to index into these tables instead of
499 /// just directly using the expression's NodeId. The reason
500 /// for this being that we may apply adjustments (coercions)
501 /// with the resulting expression also needing to use the
502 /// side tables. The problem with this is that we don't
503 /// assign a separate NodeId to this new expression
504 /// and so it would clash with the base expression if both
505 /// needed to add to the side tables. Thus to disambiguate
506 /// we also keep track of whether there's an adjustment in
508 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
509 pub struct MethodCall {
510 pub expr_id: ast::NodeId,
511 pub adjustment: ExprAdjustment
514 #[derive(Clone, PartialEq, Eq, Hash, Show, RustcEncodable, RustcDecodable, Copy)]
515 pub enum ExprAdjustment {
522 pub fn expr(id: ast::NodeId) -> MethodCall {
525 adjustment: NoAdjustment
529 pub fn autoobject(id: ast::NodeId) -> MethodCall {
532 adjustment: AutoObject
536 pub fn autoderef(expr_id: ast::NodeId, autoderef: uint) -> MethodCall {
539 adjustment: AutoDeref(1 + autoderef)
544 // maps from an expression id that corresponds to a method call to the details
545 // of the method to be invoked
546 pub type MethodMap<'tcx> = RefCell<FnvHashMap<MethodCall, MethodCallee<'tcx>>>;
548 pub type vtable_param_res<'tcx> = Vec<vtable_origin<'tcx>>;
550 // Resolutions for bounds of all parameters, left to right, for a given path.
551 pub type vtable_res<'tcx> = VecPerParamSpace<vtable_param_res<'tcx>>;
554 pub enum vtable_origin<'tcx> {
556 Statically known vtable. def_id gives the impl item
557 from whence comes the vtable, and tys are the type substs.
558 vtable_res is the vtable itself.
560 vtable_static(ast::DefId, subst::Substs<'tcx>, vtable_res<'tcx>),
563 Dynamic vtable, comes from a parameter that has a bound on it:
564 fn foo<T:quux,baz,bar>(a: T) -- a's vtable would have a
567 The first argument is the param index (identifying T in the example),
568 and the second is the bound number (identifying baz)
570 vtable_param(param_index, uint),
573 Vtable automatically generated for an unboxed closure. The def ID is the
574 ID of the closure expression.
576 vtable_unboxed_closure(ast::DefId),
579 Asked to determine the vtable for ty_err. This is the value used
580 for the vtables of `Self` in a virtual call like `foo.bar()`
581 where `foo` is of object type. The same value is also used when
588 // For every explicit cast into an object type, maps from the cast
589 // expr to the associated trait ref.
590 pub type ObjectCastMap<'tcx> = RefCell<NodeMap<ty::PolyTraitRef<'tcx>>>;
592 /// A restriction that certain types must be the same size. The use of
593 /// `transmute` gives rise to these restrictions. These generally
594 /// cannot be checked until trans; therefore, each call to `transmute`
595 /// will push one or more such restriction into the
596 /// `transmute_restrictions` vector during `intrinsicck`. They are
597 /// then checked during `trans` by the fn `check_intrinsics`.
599 pub struct TransmuteRestriction<'tcx> {
600 /// The span whence the restriction comes.
603 /// The type being transmuted from.
604 pub original_from: Ty<'tcx>,
606 /// The type being transmuted to.
607 pub original_to: Ty<'tcx>,
609 /// The type being transmuted from, with all type parameters
610 /// substituted for an arbitrary representative. Not to be shown
612 pub substituted_from: Ty<'tcx>,
614 /// The type being transmuted to, with all type parameters
615 /// substituted for an arbitrary representative. Not to be shown
617 pub substituted_to: Ty<'tcx>,
619 /// NodeId of the transmute intrinsic.
624 pub struct CtxtArenas<'tcx> {
625 type_: TypedArena<TyS<'tcx>>,
626 substs: TypedArena<Substs<'tcx>>,
627 bare_fn: TypedArena<BareFnTy<'tcx>>,
628 region: TypedArena<Region>,
631 impl<'tcx> CtxtArenas<'tcx> {
632 pub fn new() -> CtxtArenas<'tcx> {
634 type_: TypedArena::new(),
635 substs: TypedArena::new(),
636 bare_fn: TypedArena::new(),
637 region: TypedArena::new(),
642 pub struct CommonTypes<'tcx> {
660 /// The data structure to keep track of all the information that typechecker
661 /// generates so that so that it can be reused and doesn't have to be redone
663 pub struct ctxt<'tcx> {
664 /// The arenas that types etc are allocated from.
665 arenas: &'tcx CtxtArenas<'tcx>,
667 /// Specifically use a speedy hash algorithm for this hash map, it's used
669 // FIXME(eddyb) use a FnvHashSet<InternedTy<'tcx>> when equivalent keys can
670 // queried from a HashSet.
671 interner: RefCell<FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>>,
673 // FIXME as above, use a hashset if equivalent elements can be queried.
674 substs_interner: RefCell<FnvHashMap<&'tcx Substs<'tcx>, &'tcx Substs<'tcx>>>,
675 bare_fn_interner: RefCell<FnvHashMap<&'tcx BareFnTy<'tcx>, &'tcx BareFnTy<'tcx>>>,
676 region_interner: RefCell<FnvHashMap<&'tcx Region, &'tcx Region>>,
678 /// Common types, pre-interned for your convenience.
679 pub types: CommonTypes<'tcx>,
684 pub named_region_map: resolve_lifetime::NamedRegionMap,
686 pub region_maps: middle::region::RegionMaps,
688 /// Stores the types for various nodes in the AST. Note that this table
689 /// is not guaranteed to be populated until after typeck. See
690 /// typeck::check::fn_ctxt for details.
691 pub node_types: RefCell<NodeMap<Ty<'tcx>>>,
693 /// Stores the type parameters which were substituted to obtain the type
694 /// of this node. This only applies to nodes that refer to entities
695 /// parameterized by type parameters, such as generic fns, types, or
697 pub item_substs: RefCell<NodeMap<ItemSubsts<'tcx>>>,
699 /// Maps from a trait item to the trait item "descriptor"
700 pub impl_or_trait_items: RefCell<DefIdMap<ImplOrTraitItem<'tcx>>>,
702 /// Maps from a trait def-id to a list of the def-ids of its trait items
703 pub trait_item_def_ids: RefCell<DefIdMap<Rc<Vec<ImplOrTraitItemId>>>>,
705 /// A cache for the trait_items() routine
706 pub trait_items_cache: RefCell<DefIdMap<Rc<Vec<ImplOrTraitItem<'tcx>>>>>,
708 pub impl_trait_cache: RefCell<DefIdMap<Option<Rc<ty::TraitRef<'tcx>>>>>,
710 pub trait_refs: RefCell<NodeMap<Rc<TraitRef<'tcx>>>>,
711 pub trait_defs: RefCell<DefIdMap<Rc<TraitDef<'tcx>>>>,
713 /// Maps from node-id of a trait object cast (like `foo as
714 /// Box<Trait>`) to the trait reference.
715 pub object_cast_map: ObjectCastMap<'tcx>,
717 pub map: ast_map::Map<'tcx>,
718 pub intrinsic_defs: RefCell<DefIdMap<Ty<'tcx>>>,
719 pub freevars: RefCell<FreevarMap>,
720 pub tcache: RefCell<DefIdMap<TypeScheme<'tcx>>>,
721 pub rcache: RefCell<FnvHashMap<creader_cache_key, Ty<'tcx>>>,
722 pub short_names_cache: RefCell<FnvHashMap<Ty<'tcx>, String>>,
723 pub tc_cache: RefCell<FnvHashMap<Ty<'tcx>, TypeContents>>,
724 pub ast_ty_to_ty_cache: RefCell<NodeMap<ast_ty_to_ty_cache_entry<'tcx>>>,
725 pub enum_var_cache: RefCell<DefIdMap<Rc<Vec<Rc<VariantInfo<'tcx>>>>>>,
726 pub ty_param_defs: RefCell<NodeMap<TypeParameterDef<'tcx>>>,
727 pub adjustments: RefCell<NodeMap<AutoAdjustment<'tcx>>>,
728 pub normalized_cache: RefCell<FnvHashMap<Ty<'tcx>, Ty<'tcx>>>,
729 pub lang_items: middle::lang_items::LanguageItems,
730 /// A mapping of fake provided method def_ids to the default implementation
731 pub provided_method_sources: RefCell<DefIdMap<ast::DefId>>,
732 pub struct_fields: RefCell<DefIdMap<Rc<Vec<field_ty>>>>,
734 /// Maps from def-id of a type or region parameter to its
735 /// (inferred) variance.
736 pub item_variance_map: RefCell<DefIdMap<Rc<ItemVariances>>>,
738 /// True if the variance has been computed yet; false otherwise.
739 pub variance_computed: Cell<bool>,
741 /// A mapping from the def ID of an enum or struct type to the def ID
742 /// of the method that implements its destructor. If the type is not
743 /// present in this map, it does not have a destructor. This map is
744 /// populated during the coherence phase of typechecking.
745 pub destructor_for_type: RefCell<DefIdMap<ast::DefId>>,
747 /// A method will be in this list if and only if it is a destructor.
748 pub destructors: RefCell<DefIdSet>,
750 /// Maps a trait onto a list of impls of that trait.
751 pub trait_impls: RefCell<DefIdMap<Rc<RefCell<Vec<ast::DefId>>>>>,
753 /// Maps a DefId of a type to a list of its inherent impls.
754 /// Contains implementations of methods that are inherent to a type.
755 /// Methods in these implementations don't need to be exported.
756 pub inherent_impls: RefCell<DefIdMap<Rc<Vec<ast::DefId>>>>,
758 /// Maps a DefId of an impl to a list of its items.
759 /// Note that this contains all of the impls that we know about,
760 /// including ones in other crates. It's not clear that this is the best
762 pub impl_items: RefCell<DefIdMap<Vec<ImplOrTraitItemId>>>,
764 /// Set of used unsafe nodes (functions or blocks). Unsafe nodes not
765 /// present in this set can be warned about.
766 pub used_unsafe: RefCell<NodeSet>,
768 /// Set of nodes which mark locals as mutable which end up getting used at
769 /// some point. Local variable definitions not in this set can be warned
771 pub used_mut_nodes: RefCell<NodeSet>,
773 /// The set of external nominal types whose implementations have been read.
774 /// This is used for lazy resolution of methods.
775 pub populated_external_types: RefCell<DefIdSet>,
777 /// The set of external traits whose implementations have been read. This
778 /// is used for lazy resolution of traits.
779 pub populated_external_traits: RefCell<DefIdSet>,
782 pub upvar_borrow_map: RefCell<UpvarBorrowMap>,
784 /// These two caches are used by const_eval when decoding external statics
785 /// and variants that are found.
786 pub extern_const_statics: RefCell<DefIdMap<ast::NodeId>>,
787 pub extern_const_variants: RefCell<DefIdMap<ast::NodeId>>,
789 pub method_map: MethodMap<'tcx>,
791 pub dependency_formats: RefCell<dependency_format::Dependencies>,
793 /// Records the type of each unboxed closure. The def ID is the ID of the
794 /// expression defining the unboxed closure.
795 pub unboxed_closures: RefCell<DefIdMap<UnboxedClosure<'tcx>>>,
797 pub node_lint_levels: RefCell<FnvHashMap<(ast::NodeId, lint::LintId),
800 /// The types that must be asserted to be the same size for `transmute`
801 /// to be valid. We gather up these restrictions in the intrinsicck pass
802 /// and check them in trans.
803 pub transmute_restrictions: RefCell<Vec<TransmuteRestriction<'tcx>>>,
805 /// Maps any item's def-id to its stability index.
806 pub stability: RefCell<stability::Index>,
808 /// Maps closures to their capture clauses.
809 pub capture_modes: RefCell<CaptureModeMap>,
811 /// Maps def IDs to true if and only if they're associated types.
812 pub associated_types: RefCell<DefIdMap<bool>>,
814 /// Caches the results of trait selection. This cache is used
815 /// for things that do not have to do with the parameters in scope.
816 pub selection_cache: traits::SelectionCache<'tcx>,
818 /// Caches the representation hints for struct definitions.
819 pub repr_hint_cache: RefCell<DefIdMap<Rc<Vec<attr::ReprAttr>>>>,
821 /// Caches whether types are known to impl Copy. Note that type
822 /// parameters are never placed into this cache, because their
823 /// results are dependent on the parameter environment.
824 pub type_impls_copy_cache: RefCell<HashMap<Ty<'tcx>,bool>>,
826 /// Caches whether types are known to impl Sized. Note that type
827 /// parameters are never placed into this cache, because their
828 /// results are dependent on the parameter environment.
829 pub type_impls_sized_cache: RefCell<HashMap<Ty<'tcx>,bool>>,
831 /// Caches whether traits are object safe
832 pub object_safety_cache: RefCell<DefIdMap<bool>>,
835 // Flags that we track on types. These flags are propagated upwards
836 // through the type during type construction, so that we can quickly
837 // check whether the type has various kinds of types in it without
838 // recursing over the type itself.
840 flags TypeFlags: u32 {
841 const NO_TYPE_FLAGS = 0b0,
842 const HAS_PARAMS = 0b1,
843 const HAS_SELF = 0b10,
844 const HAS_TY_INFER = 0b100,
845 const HAS_RE_INFER = 0b1000,
846 const HAS_RE_LATE_BOUND = 0b10000,
847 const HAS_REGIONS = 0b100000,
848 const HAS_TY_ERR = 0b1000000,
849 const HAS_PROJECTION = 0b10000000,
850 const NEEDS_SUBST = HAS_PARAMS.bits | HAS_SELF.bits | HAS_REGIONS.bits,
854 macro_rules! sty_debug_print {
855 ($ctxt: expr, $($variant: ident),*) => {{
856 // curious inner module to allow variant names to be used as
868 pub fn go(tcx: &ty::ctxt) {
869 let mut total = DebugStat {
871 region_infer: 0, ty_infer: 0, both_infer: 0,
873 $(let mut $variant = total;)*
876 for (_, t) in tcx.interner.borrow().iter() {
877 let variant = match t.sty {
878 ty::ty_bool | ty::ty_char | ty::ty_int(..) | ty::ty_uint(..) |
879 ty::ty_float(..) | ty::ty_str => continue,
880 ty::ty_err => /* unimportant */ continue,
881 $(ty::$variant(..) => &mut $variant,)*
883 let region = t.flags.intersects(ty::HAS_RE_INFER);
884 let ty = t.flags.intersects(ty::HAS_TY_INFER);
888 if region { total.region_infer += 1; variant.region_infer += 1 }
889 if ty { total.ty_infer += 1; variant.ty_infer += 1 }
890 if region && ty { total.both_infer += 1; variant.both_infer += 1 }
892 println!("Ty interner total ty region both");
893 $(println!(" {:18}: {uses:6} {usespc:4.1}%, \
894 {ty:4.1}% {region:5.1}% {both:4.1}%",
895 stringify!($variant),
896 uses = $variant.total,
897 usespc = $variant.total as f64 * 100.0 / total.total as f64,
898 ty = $variant.ty_infer as f64 * 100.0 / total.total as f64,
899 region = $variant.region_infer as f64 * 100.0 / total.total as f64,
900 both = $variant.both_infer as f64 * 100.0 / total.total as f64);
902 println!(" total {uses:6} \
903 {ty:4.1}% {region:5.1}% {both:4.1}%",
905 ty = total.ty_infer as f64 * 100.0 / total.total as f64,
906 region = total.region_infer as f64 * 100.0 / total.total as f64,
907 both = total.both_infer as f64 * 100.0 / total.total as f64)
915 impl<'tcx> ctxt<'tcx> {
916 pub fn print_debug_stats(&self) {
919 ty_enum, ty_uniq, ty_vec, ty_ptr, ty_rptr, ty_bare_fn, ty_trait,
920 ty_struct, ty_unboxed_closure, ty_tup, ty_param, ty_open, ty_infer, ty_projection);
922 println!("Substs interner: #{}", self.substs_interner.borrow().len());
923 println!("BareFnTy interner: #{}", self.bare_fn_interner.borrow().len());
924 println!("Region interner: #{}", self.region_interner.borrow().len());
929 pub struct TyS<'tcx> {
931 pub flags: TypeFlags,
933 // the maximal depth of any bound regions appearing in this type.
937 impl fmt::Show for TypeFlags {
938 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
939 write!(f, "{}", self.bits)
943 impl<'tcx> PartialEq for TyS<'tcx> {
944 fn eq(&self, other: &TyS<'tcx>) -> bool {
945 (self as *const _) == (other as *const _)
948 impl<'tcx> Eq for TyS<'tcx> {}
950 impl<'tcx, S: Writer> Hash<S> for TyS<'tcx> {
951 fn hash(&self, s: &mut S) {
952 (self as *const _).hash(s)
956 pub type Ty<'tcx> = &'tcx TyS<'tcx>;
958 /// An entry in the type interner.
959 pub struct InternedTy<'tcx> {
963 // NB: An InternedTy compares and hashes as a sty.
964 impl<'tcx> PartialEq for InternedTy<'tcx> {
965 fn eq(&self, other: &InternedTy<'tcx>) -> bool {
966 self.ty.sty == other.ty.sty
970 impl<'tcx> Eq for InternedTy<'tcx> {}
972 impl<'tcx, S: Writer> Hash<S> for InternedTy<'tcx> {
973 fn hash(&self, s: &mut S) {
978 impl<'tcx> BorrowFrom<InternedTy<'tcx>> for sty<'tcx> {
979 fn borrow_from<'a>(ty: &'a InternedTy<'tcx>) -> &'a sty<'tcx> {
984 pub fn type_has_params(ty: Ty) -> bool {
985 ty.flags.intersects(HAS_PARAMS)
987 pub fn type_has_self(ty: Ty) -> bool {
988 ty.flags.intersects(HAS_SELF)
990 pub fn type_has_ty_infer(ty: Ty) -> bool {
991 ty.flags.intersects(HAS_TY_INFER)
993 pub fn type_needs_infer(ty: Ty) -> bool {
994 ty.flags.intersects(HAS_TY_INFER | HAS_RE_INFER)
996 pub fn type_has_projection(ty: Ty) -> bool {
997 ty.flags.intersects(HAS_PROJECTION)
1000 pub fn type_has_late_bound_regions(ty: Ty) -> bool {
1001 ty.flags.intersects(HAS_RE_LATE_BOUND)
1004 /// An "escaping region" is a bound region whose binder is not part of `t`.
1006 /// So, for example, consider a type like the following, which has two binders:
1008 /// for<'a> fn(x: for<'b> fn(&'a int, &'b int))
1009 /// ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ outer scope
1010 /// ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ inner scope
1012 /// This type has *bound regions* (`'a`, `'b`), but it does not have escaping regions, because the
1013 /// binders of both `'a` and `'b` are part of the type itself. However, if we consider the *inner
1014 /// fn type*, that type has an escaping region: `'a`.
1016 /// Note that what I'm calling an "escaping region" is often just called a "free region". However,
1017 /// we already use the term "free region". It refers to the regions that we use to represent bound
1018 /// regions on a fn definition while we are typechecking its body.
1020 /// To clarify, conceptually there is no particular difference between an "escaping" region and a
1021 /// "free" region. However, there is a big difference in practice. Basically, when "entering" a
1022 /// binding level, one is generally required to do some sort of processing to a bound region, such
1023 /// as replacing it with a fresh/skolemized region, or making an entry in the environment to
1024 /// represent the scope to which it is attached, etc. An escaping region represents a bound region
1025 /// for which this processing has not yet been done.
1026 pub fn type_has_escaping_regions(ty: Ty) -> bool {
1027 type_escapes_depth(ty, 0)
1030 pub fn type_escapes_depth(ty: Ty, depth: u32) -> bool {
1031 ty.region_depth > depth
1034 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1035 pub struct BareFnTy<'tcx> {
1036 pub unsafety: ast::Unsafety,
1038 pub sig: PolyFnSig<'tcx>,
1041 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1042 pub struct ClosureTy<'tcx> {
1043 pub unsafety: ast::Unsafety,
1044 pub onceness: ast::Onceness,
1045 pub store: TraitStore,
1046 pub bounds: ExistentialBounds<'tcx>,
1047 pub sig: PolyFnSig<'tcx>,
1051 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1052 pub enum FnOutput<'tcx> {
1053 FnConverging(Ty<'tcx>),
1057 impl<'tcx> FnOutput<'tcx> {
1058 pub fn unwrap(self) -> Ty<'tcx> {
1060 ty::FnConverging(t) => t,
1061 ty::FnDiverging => unreachable!()
1066 /// Signature of a function type, which I have arbitrarily
1067 /// decided to use to refer to the input/output types.
1069 /// - `inputs` is the list of arguments and their modes.
1070 /// - `output` is the return type.
1071 /// - `variadic` indicates whether this is a varidic function. (only true for foreign fns)
1072 #[derive(Clone, PartialEq, Eq, Hash)]
1073 pub struct FnSig<'tcx> {
1074 pub inputs: Vec<Ty<'tcx>>,
1075 pub output: FnOutput<'tcx>,
1079 pub type PolyFnSig<'tcx> = Binder<FnSig<'tcx>>;
1081 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
1082 pub struct ParamTy {
1083 pub space: subst::ParamSpace,
1085 pub name: ast::Name,
1088 /// A [De Bruijn index][dbi] is a standard means of representing
1089 /// regions (and perhaps later types) in a higher-ranked setting. In
1090 /// particular, imagine a type like this:
1092 /// for<'a> fn(for<'b> fn(&'b int, &'a int), &'a char)
1095 /// | +------------+ 1 | |
1097 /// +--------------------------------+ 2 |
1099 /// +------------------------------------------+ 1
1101 /// In this type, there are two binders (the outer fn and the inner
1102 /// fn). We need to be able to determine, for any given region, which
1103 /// fn type it is bound by, the inner or the outer one. There are
1104 /// various ways you can do this, but a De Bruijn index is one of the
1105 /// more convenient and has some nice properties. The basic idea is to
1106 /// count the number of binders, inside out. Some examples should help
1107 /// clarify what I mean.
1109 /// Let's start with the reference type `&'b int` that is the first
1110 /// argument to the inner function. This region `'b` is assigned a De
1111 /// Bruijn index of 1, meaning "the innermost binder" (in this case, a
1112 /// fn). The region `'a` that appears in the second argument type (`&'a
1113 /// int`) would then be assigned a De Bruijn index of 2, meaning "the
1114 /// second-innermost binder". (These indices are written on the arrays
1115 /// in the diagram).
1117 /// What is interesting is that De Bruijn index attached to a particular
1118 /// variable will vary depending on where it appears. For example,
1119 /// the final type `&'a char` also refers to the region `'a` declared on
1120 /// the outermost fn. But this time, this reference is not nested within
1121 /// any other binders (i.e., it is not an argument to the inner fn, but
1122 /// rather the outer one). Therefore, in this case, it is assigned a
1123 /// De Bruijn index of 1, because the innermost binder in that location
1124 /// is the outer fn.
1126 /// [dbi]: http://en.wikipedia.org/wiki/De_Bruijn_index
1127 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Show, Copy)]
1128 pub struct DebruijnIndex {
1129 // We maintain the invariant that this is never 0. So 1 indicates
1130 // the innermost binder. To ensure this, create with `DebruijnIndex::new`.
1134 /// Representation of regions:
1135 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Show, Copy)]
1137 // Region bound in a type or fn declaration which will be
1138 // substituted 'early' -- that is, at the same time when type
1139 // parameters are substituted.
1140 ReEarlyBound(/* param id */ ast::NodeId,
1145 // Region bound in a function scope, which will be substituted when the
1146 // function is called.
1147 ReLateBound(DebruijnIndex, BoundRegion),
1149 /// When checking a function body, the types of all arguments and so forth
1150 /// that refer to bound region parameters are modified to refer to free
1151 /// region parameters.
1154 /// A concrete region naming some expression within the current function.
1155 ReScope(region::CodeExtent),
1157 /// Static data that has an "infinite" lifetime. Top in the region lattice.
1160 /// A region variable. Should not exist after typeck.
1161 ReInfer(InferRegion),
1163 /// Empty lifetime is for data that is never accessed.
1164 /// Bottom in the region lattice. We treat ReEmpty somewhat
1165 /// specially; at least right now, we do not generate instances of
1166 /// it during the GLB computations, but rather
1167 /// generate an error instead. This is to improve error messages.
1168 /// The only way to get an instance of ReEmpty is to have a region
1169 /// variable with no constraints.
1173 /// Upvars do not get their own node-id. Instead, we use the pair of
1174 /// the original var id (that is, the root variable that is referenced
1175 /// by the upvar) and the id of the closure expression.
1176 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
1177 pub struct UpvarId {
1178 pub var_id: ast::NodeId,
1179 pub closure_expr_id: ast::NodeId,
1182 #[derive(Clone, PartialEq, Eq, Hash, Show, RustcEncodable, RustcDecodable, Copy)]
1183 pub enum BorrowKind {
1184 /// Data must be immutable and is aliasable.
1187 /// Data must be immutable but not aliasable. This kind of borrow
1188 /// cannot currently be expressed by the user and is used only in
1189 /// implicit closure bindings. It is needed when you the closure
1190 /// is borrowing or mutating a mutable referent, e.g.:
1192 /// let x: &mut int = ...;
1193 /// let y = || *x += 5;
1195 /// If we were to try to translate this closure into a more explicit
1196 /// form, we'd encounter an error with the code as written:
1198 /// struct Env { x: & &mut int }
1199 /// let x: &mut int = ...;
1200 /// let y = (&mut Env { &x }, fn_ptr); // Closure is pair of env and fn
1201 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
1203 /// This is then illegal because you cannot mutate a `&mut` found
1204 /// in an aliasable location. To solve, you'd have to translate with
1205 /// an `&mut` borrow:
1207 /// struct Env { x: & &mut int }
1208 /// let x: &mut int = ...;
1209 /// let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x
1210 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
1212 /// Now the assignment to `**env.x` is legal, but creating a
1213 /// mutable pointer to `x` is not because `x` is not mutable. We
1214 /// could fix this by declaring `x` as `let mut x`. This is ok in
1215 /// user code, if awkward, but extra weird for closures, since the
1216 /// borrow is hidden.
1218 /// So we introduce a "unique imm" borrow -- the referent is
1219 /// immutable, but not aliasable. This solves the problem. For
1220 /// simplicity, we don't give users the way to express this
1221 /// borrow, it's just used when translating closures.
1224 /// Data is mutable and not aliasable.
1228 /// Information describing the borrowing of an upvar. This is computed
1229 /// during `typeck`, specifically by `regionck`. The general idea is
1230 /// that the compiler analyses treat closures like:
1232 /// let closure: &'e fn() = || {
1233 /// x = 1; // upvar x is assigned to
1234 /// use(y); // upvar y is read
1235 /// foo(&z); // upvar z is borrowed immutably
1238 /// as if they were "desugared" to something loosely like:
1240 /// struct Vars<'x,'y,'z> { x: &'x mut int,
1241 /// y: &'y const int,
1243 /// let closure: &'e fn() = {
1244 /// fn f(env: &Vars) {
1249 /// let env: &'e mut Vars<'x,'y,'z> = &mut Vars { x: &'x mut x,
1255 /// This is basically what happens at runtime. The closure is basically
1256 /// an existentially quantified version of the `(env, f)` pair.
1258 /// This data structure indicates the region and mutability of a single
1259 /// one of the `x...z` borrows.
1261 /// It may not be obvious why each borrowed variable gets its own
1262 /// lifetime (in the desugared version of the example, these are indicated
1263 /// by the lifetime parameters `'x`, `'y`, and `'z` in the `Vars` definition).
1264 /// Each such lifetime must encompass the lifetime `'e` of the closure itself,
1265 /// but need not be identical to it. The reason that this makes sense:
1267 /// - Callers are only permitted to invoke the closure, and hence to
1268 /// use the pointers, within the lifetime `'e`, so clearly `'e` must
1269 /// be a sublifetime of `'x...'z`.
1270 /// - The closure creator knows which upvars were borrowed by the closure
1271 /// and thus `x...z` will be reserved for `'x...'z` respectively.
1272 /// - Through mutation, the borrowed upvars can actually escape
1273 /// the closure, so sometimes it is necessary for them to be larger
1274 /// than the closure lifetime itself.
1275 #[derive(PartialEq, Clone, RustcEncodable, RustcDecodable, Show, Copy)]
1276 pub struct UpvarBorrow {
1277 pub kind: BorrowKind,
1278 pub region: ty::Region,
1281 pub type UpvarBorrowMap = FnvHashMap<UpvarId, UpvarBorrow>;
1284 pub fn is_bound(&self) -> bool {
1286 ty::ReEarlyBound(..) => true,
1287 ty::ReLateBound(..) => true,
1292 pub fn escapes_depth(&self, depth: u32) -> bool {
1294 ty::ReLateBound(debruijn, _) => debruijn.depth > depth,
1300 #[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
1301 RustcEncodable, RustcDecodable, Show, Copy)]
1302 /// A "free" region `fr` can be interpreted as "some region
1303 /// at least as big as the scope `fr.scope`".
1304 pub struct FreeRegion {
1305 pub scope: region::CodeExtent,
1306 pub bound_region: BoundRegion
1309 #[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
1310 RustcEncodable, RustcDecodable, Show, Copy)]
1311 pub enum BoundRegion {
1312 /// An anonymous region parameter for a given fn (&T)
1315 /// Named region parameters for functions (a in &'a T)
1317 /// The def-id is needed to distinguish free regions in
1318 /// the event of shadowing.
1319 BrNamed(ast::DefId, ast::Name),
1321 /// Fresh bound identifiers created during GLB computations.
1324 // Anonymous region for the implicit env pointer parameter
1329 // NB: If you change this, you'll probably want to change the corresponding
1330 // AST structure in libsyntax/ast.rs as well.
1331 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1332 pub enum sty<'tcx> {
1336 ty_uint(ast::UintTy),
1337 ty_float(ast::FloatTy),
1338 /// Substs here, possibly against intuition, *may* contain `ty_param`s.
1339 /// That is, even after substitution it is possible that there are type
1340 /// variables. This happens when the `ty_enum` corresponds to an enum
1341 /// definition and not a concrete use of it. To get the correct `ty_enum`
1342 /// from the tcx, use the `NodeId` from the `ast::Ty` and look it up in
1343 /// the `ast_ty_to_ty_cache`. This is probably true for `ty_struct` as
1345 ty_enum(DefId, &'tcx Substs<'tcx>),
1348 ty_vec(Ty<'tcx>, Option<uint>), // Second field is length.
1350 ty_rptr(&'tcx Region, mt<'tcx>),
1352 // If the def-id is Some(_), then this is the type of a specific
1353 // fn item. Otherwise, if None(_), it a fn pointer type.
1354 ty_bare_fn(Option<DefId>, &'tcx BareFnTy<'tcx>),
1356 ty_trait(Box<TyTrait<'tcx>>),
1357 ty_struct(DefId, &'tcx Substs<'tcx>),
1359 ty_unboxed_closure(DefId, &'tcx Region, &'tcx Substs<'tcx>),
1361 ty_tup(Vec<Ty<'tcx>>),
1363 ty_projection(ProjectionTy<'tcx>),
1364 ty_param(ParamTy), // type parameter
1366 ty_open(Ty<'tcx>), // A deref'ed fat pointer, i.e., a dynamically sized value
1367 // and its size. Only ever used in trans. It is not necessary
1368 // earlier since we don't need to distinguish a DST with its
1369 // size (e.g., in a deref) vs a DST with the size elsewhere (
1370 // e.g., in a field).
1372 ty_infer(InferTy), // something used only during inference/typeck
1373 ty_err, // Also only used during inference/typeck, to represent
1374 // the type of an erroneous expression (helps cut down
1375 // on non-useful type error messages)
1378 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1379 pub struct TyTrait<'tcx> {
1380 pub principal: ty::PolyTraitRef<'tcx>,
1381 pub bounds: ExistentialBounds<'tcx>,
1384 impl<'tcx> TyTrait<'tcx> {
1385 pub fn principal_def_id(&self) -> ast::DefId {
1386 self.principal.0.def_id
1389 /// Object types don't have a self-type specified. Therefore, when
1390 /// we convert the principal trait-ref into a normal trait-ref,
1391 /// you must give *some* self-type. A common choice is `mk_err()`
1392 /// or some skolemized type.
1393 pub fn principal_trait_ref_with_self_ty(&self,
1396 -> ty::PolyTraitRef<'tcx>
1398 // otherwise the escaping regions would be captured by the binder
1399 assert!(!self_ty.has_escaping_regions());
1401 ty::Binder(Rc::new(ty::TraitRef {
1402 def_id: self.principal.0.def_id,
1403 substs: tcx.mk_substs(self.principal.0.substs.with_self_ty(self_ty)),
1407 pub fn projection_bounds_with_self_ty(&self,
1410 -> Vec<ty::PolyProjectionPredicate<'tcx>>
1412 // otherwise the escaping regions would be captured by the binders
1413 assert!(!self_ty.has_escaping_regions());
1415 self.bounds.projection_bounds.iter()
1416 .map(|in_poly_projection_predicate| {
1417 let in_projection_ty = &in_poly_projection_predicate.0.projection_ty;
1418 let substs = tcx.mk_substs(in_projection_ty.trait_ref.substs.with_self_ty(self_ty));
1420 Rc::new(ty::TraitRef::new(in_projection_ty.trait_ref.def_id,
1422 let projection_ty = ty::ProjectionTy {
1423 trait_ref: trait_ref,
1424 item_name: in_projection_ty.item_name
1426 ty::Binder(ty::ProjectionPredicate {
1427 projection_ty: projection_ty,
1428 ty: in_poly_projection_predicate.0.ty
1435 /// A complete reference to a trait. These take numerous guises in syntax,
1436 /// but perhaps the most recognizable form is in a where clause:
1440 /// This would be represented by a trait-reference where the def-id is the
1441 /// def-id for the trait `Foo` and the substs defines `T` as parameter 0 in the
1442 /// `SelfSpace` and `U` as parameter 0 in the `TypeSpace`.
1444 /// Trait references also appear in object types like `Foo<U>`, but in
1445 /// that case the `Self` parameter is absent from the substitutions.
1447 /// Note that a `TraitRef` introduces a level of region binding, to
1448 /// account for higher-ranked trait bounds like `T : for<'a> Foo<&'a
1449 /// U>` or higher-ranked object types.
1450 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1451 pub struct TraitRef<'tcx> {
1453 pub substs: &'tcx Substs<'tcx>,
1456 pub type PolyTraitRef<'tcx> = Binder<Rc<TraitRef<'tcx>>>;
1458 impl<'tcx> PolyTraitRef<'tcx> {
1459 pub fn self_ty(&self) -> Ty<'tcx> {
1463 pub fn def_id(&self) -> ast::DefId {
1467 pub fn substs(&self) -> &'tcx Substs<'tcx> {
1471 pub fn input_types(&self) -> &[Ty<'tcx>] {
1472 self.0.input_types()
1475 pub fn to_poly_trait_predicate(&self) -> PolyTraitPredicate<'tcx> {
1476 // Note that we preserve binding levels
1477 Binder(TraitPredicate { trait_ref: self.0.clone() })
1481 /// Binder is a binder for higher-ranked lifetimes. It is part of the
1482 /// compiler's representation for things like `for<'a> Fn(&'a int)`
1483 /// (which would be represented by the type `PolyTraitRef ==
1484 /// Binder<TraitRef>`). Note that when we skolemize, instantiate,
1485 /// erase, or otherwise "discharge" these bound reons, we change the
1486 /// type from `Binder<T>` to just `T` (see
1487 /// e.g. `liberate_late_bound_regions`).
1488 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1489 pub struct Binder<T>(pub T);
1491 #[derive(Clone, Copy, PartialEq)]
1492 pub enum IntVarValue {
1493 IntType(ast::IntTy),
1494 UintType(ast::UintTy),
1497 #[derive(Clone, Copy, Show)]
1498 pub enum terr_vstore_kind {
1505 #[derive(Clone, Copy, Show)]
1506 pub struct expected_found<T> {
1511 // Data structures used in type unification
1512 #[derive(Clone, Copy, Show)]
1513 pub enum type_err<'tcx> {
1515 terr_unsafety_mismatch(expected_found<ast::Unsafety>),
1516 terr_onceness_mismatch(expected_found<Onceness>),
1517 terr_abi_mismatch(expected_found<abi::Abi>),
1519 terr_sigil_mismatch(expected_found<TraitStore>),
1520 terr_box_mutability,
1521 terr_ptr_mutability,
1522 terr_ref_mutability,
1523 terr_vec_mutability,
1524 terr_tuple_size(expected_found<uint>),
1525 terr_fixed_array_size(expected_found<uint>),
1526 terr_ty_param_size(expected_found<uint>),
1528 terr_regions_does_not_outlive(Region, Region),
1529 terr_regions_not_same(Region, Region),
1530 terr_regions_no_overlap(Region, Region),
1531 terr_regions_insufficiently_polymorphic(BoundRegion, Region),
1532 terr_regions_overly_polymorphic(BoundRegion, Region),
1533 terr_trait_stores_differ(terr_vstore_kind, expected_found<TraitStore>),
1534 terr_sorts(expected_found<Ty<'tcx>>),
1535 terr_integer_as_char,
1536 terr_int_mismatch(expected_found<IntVarValue>),
1537 terr_float_mismatch(expected_found<ast::FloatTy>),
1538 terr_traits(expected_found<ast::DefId>),
1539 terr_builtin_bounds(expected_found<BuiltinBounds>),
1540 terr_variadic_mismatch(expected_found<bool>),
1542 terr_convergence_mismatch(expected_found<bool>),
1543 terr_projection_name_mismatched(expected_found<ast::Name>),
1544 terr_projection_bounds_length(expected_found<uint>),
1547 /// Bounds suitable for a named type parameter like `A` in `fn foo<A>`
1548 /// as well as the existential type parameter in an object type.
1549 #[derive(PartialEq, Eq, Hash, Clone, Show)]
1550 pub struct ParamBounds<'tcx> {
1551 pub region_bounds: Vec<ty::Region>,
1552 pub builtin_bounds: BuiltinBounds,
1553 pub trait_bounds: Vec<PolyTraitRef<'tcx>>,
1554 pub projection_bounds: Vec<PolyProjectionPredicate<'tcx>>,
1557 /// Bounds suitable for an existentially quantified type parameter
1558 /// such as those that appear in object types or closure types. The
1559 /// major difference between this case and `ParamBounds` is that
1560 /// general purpose trait bounds are omitted and there must be
1561 /// *exactly one* region.
1562 #[derive(PartialEq, Eq, Hash, Clone, Show)]
1563 pub struct ExistentialBounds<'tcx> {
1564 pub region_bound: ty::Region,
1565 pub builtin_bounds: BuiltinBounds,
1566 pub projection_bounds: Vec<PolyProjectionPredicate<'tcx>>,
1569 pub type BuiltinBounds = EnumSet<BuiltinBound>;
1571 #[derive(Clone, RustcEncodable, PartialEq, Eq, RustcDecodable, Hash,
1574 pub enum BuiltinBound {
1581 pub fn empty_builtin_bounds() -> BuiltinBounds {
1585 pub fn all_builtin_bounds() -> BuiltinBounds {
1586 let mut set = EnumSet::new();
1587 set.insert(BoundSend);
1588 set.insert(BoundSized);
1589 set.insert(BoundSync);
1593 /// An existential bound that does not implement any traits.
1594 pub fn region_existential_bound<'tcx>(r: ty::Region) -> ExistentialBounds<'tcx> {
1595 ty::ExistentialBounds { region_bound: r,
1596 builtin_bounds: empty_builtin_bounds(),
1597 projection_bounds: Vec::new() }
1600 impl CLike for BuiltinBound {
1601 fn to_uint(&self) -> uint {
1604 fn from_uint(v: uint) -> BuiltinBound {
1605 unsafe { mem::transmute(v) }
1609 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1614 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1619 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1620 pub struct FloatVid {
1624 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
1625 pub struct RegionVid {
1629 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1635 /// A `FreshTy` is one that is generated as a replacement for an
1636 /// unbound type variable. This is convenient for caching etc. See
1637 /// `middle::infer::freshen` for more details.
1640 // FIXME -- once integral fallback is impl'd, we should remove
1641 // this type. It's only needed to prevent spurious errors for
1642 // integers whose type winds up never being constrained.
1646 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Show, Copy)]
1647 pub enum UnconstrainedNumeric {
1654 #[derive(Clone, RustcEncodable, RustcDecodable, Eq, Hash, Show, Copy)]
1655 pub enum InferRegion {
1657 ReSkolemized(u32, BoundRegion)
1660 impl cmp::PartialEq for InferRegion {
1661 fn eq(&self, other: &InferRegion) -> bool {
1662 match ((*self), *other) {
1663 (ReVar(rva), ReVar(rvb)) => {
1666 (ReSkolemized(rva, _), ReSkolemized(rvb, _)) => {
1672 fn ne(&self, other: &InferRegion) -> bool {
1673 !((*self) == (*other))
1677 impl fmt::Show for TyVid {
1678 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result{
1679 write!(f, "_#{}t", self.index)
1683 impl fmt::Show for IntVid {
1684 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1685 write!(f, "_#{}i", self.index)
1689 impl fmt::Show for FloatVid {
1690 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1691 write!(f, "_#{}f", self.index)
1695 impl fmt::Show for RegionVid {
1696 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1697 write!(f, "'_#{}r", self.index)
1701 impl<'tcx> fmt::Show for FnSig<'tcx> {
1702 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1703 // grr, without tcx not much we can do.
1708 impl fmt::Show for InferTy {
1709 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1711 TyVar(ref v) => v.fmt(f),
1712 IntVar(ref v) => v.fmt(f),
1713 FloatVar(ref v) => v.fmt(f),
1714 FreshTy(v) => write!(f, "FreshTy({})", v),
1715 FreshIntTy(v) => write!(f, "FreshIntTy({})", v),
1720 impl fmt::Show for IntVarValue {
1721 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1723 IntType(ref v) => v.fmt(f),
1724 UintType(ref v) => v.fmt(f),
1729 #[derive(Clone, Show)]
1730 pub struct TypeParameterDef<'tcx> {
1731 pub name: ast::Name,
1732 pub def_id: ast::DefId,
1733 pub space: subst::ParamSpace,
1735 pub bounds: ParamBounds<'tcx>,
1736 pub default: Option<Ty<'tcx>>,
1739 #[derive(RustcEncodable, RustcDecodable, Clone, Show)]
1740 pub struct RegionParameterDef {
1741 pub name: ast::Name,
1742 pub def_id: ast::DefId,
1743 pub space: subst::ParamSpace,
1745 pub bounds: Vec<ty::Region>,
1748 impl RegionParameterDef {
1749 pub fn to_early_bound_region(&self) -> ty::Region {
1750 ty::ReEarlyBound(self.def_id.node, self.space, self.index, self.name)
1754 /// Information about the formal type/lifetime parameters associated
1755 /// with an item or method. Analogous to ast::Generics.
1756 #[derive(Clone, Show)]
1757 pub struct Generics<'tcx> {
1758 pub types: VecPerParamSpace<TypeParameterDef<'tcx>>,
1759 pub regions: VecPerParamSpace<RegionParameterDef>,
1760 pub predicates: VecPerParamSpace<Predicate<'tcx>>,
1763 impl<'tcx> Generics<'tcx> {
1764 pub fn empty() -> Generics<'tcx> {
1766 types: VecPerParamSpace::empty(),
1767 regions: VecPerParamSpace::empty(),
1768 predicates: VecPerParamSpace::empty(),
1772 pub fn has_type_params(&self, space: subst::ParamSpace) -> bool {
1773 !self.types.is_empty_in(space)
1776 pub fn has_region_params(&self, space: subst::ParamSpace) -> bool {
1777 !self.regions.is_empty_in(space)
1780 pub fn to_bounds(&self, tcx: &ty::ctxt<'tcx>, substs: &Substs<'tcx>)
1781 -> GenericBounds<'tcx> {
1783 predicates: self.predicates.subst(tcx, substs),
1788 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1789 pub enum Predicate<'tcx> {
1790 /// Corresponds to `where Foo : Bar<A,B,C>`. `Foo` here would be
1791 /// the `Self` type of the trait reference and `A`, `B`, and `C`
1792 /// would be the parameters in the `TypeSpace`.
1793 Trait(PolyTraitPredicate<'tcx>),
1795 /// where `T1 == T2`.
1796 Equate(PolyEquatePredicate<'tcx>),
1799 RegionOutlives(PolyRegionOutlivesPredicate),
1802 TypeOutlives(PolyTypeOutlivesPredicate<'tcx>),
1804 /// where <T as TraitRef>::Name == X, approximately.
1805 /// See `ProjectionPredicate` struct for details.
1806 Projection(PolyProjectionPredicate<'tcx>),
1809 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1810 pub struct TraitPredicate<'tcx> {
1811 pub trait_ref: Rc<TraitRef<'tcx>>
1813 pub type PolyTraitPredicate<'tcx> = ty::Binder<TraitPredicate<'tcx>>;
1815 impl<'tcx> TraitPredicate<'tcx> {
1816 pub fn def_id(&self) -> ast::DefId {
1817 self.trait_ref.def_id
1820 pub fn input_types(&self) -> &[Ty<'tcx>] {
1821 self.trait_ref.substs.types.as_slice()
1824 pub fn self_ty(&self) -> Ty<'tcx> {
1825 self.trait_ref.self_ty()
1829 impl<'tcx> PolyTraitPredicate<'tcx> {
1830 pub fn def_id(&self) -> ast::DefId {
1835 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1836 pub struct EquatePredicate<'tcx>(pub Ty<'tcx>, pub Ty<'tcx>); // `0 == 1`
1837 pub type PolyEquatePredicate<'tcx> = ty::Binder<EquatePredicate<'tcx>>;
1839 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1840 pub struct OutlivesPredicate<A,B>(pub A, pub B); // `A : B`
1841 pub type PolyOutlivesPredicate<A,B> = ty::Binder<OutlivesPredicate<A,B>>;
1842 pub type PolyRegionOutlivesPredicate = PolyOutlivesPredicate<ty::Region, ty::Region>;
1843 pub type PolyTypeOutlivesPredicate<'tcx> = PolyOutlivesPredicate<Ty<'tcx>, ty::Region>;
1845 /// This kind of predicate has no *direct* correspondent in the
1846 /// syntax, but it roughly corresponds to the syntactic forms:
1848 /// 1. `T : TraitRef<..., Item=Type>`
1849 /// 2. `<T as TraitRef<...>>::Item == Type` (NYI)
1851 /// In particular, form #1 is "desugared" to the combination of a
1852 /// normal trait predicate (`T : TraitRef<...>`) and one of these
1853 /// predicates. Form #2 is a broader form in that it also permits
1854 /// equality between arbitrary types. Processing an instance of Form
1855 /// #2 eventually yields one of these `ProjectionPredicate`
1856 /// instances to normalize the LHS.
1857 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1858 pub struct ProjectionPredicate<'tcx> {
1859 pub projection_ty: ProjectionTy<'tcx>,
1863 pub type PolyProjectionPredicate<'tcx> = Binder<ProjectionPredicate<'tcx>>;
1865 impl<'tcx> PolyProjectionPredicate<'tcx> {
1866 pub fn sort_key(&self) -> (ast::DefId, ast::Name) {
1867 self.0.projection_ty.sort_key()
1871 /// Represents the projection of an associated type. In explicit UFCS
1872 /// form this would be written `<T as Trait<..>>::N`.
1873 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1874 pub struct ProjectionTy<'tcx> {
1875 /// The trait reference `T as Trait<..>`.
1876 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
1878 /// The name `N` of the associated type.
1879 pub item_name: ast::Name,
1882 impl<'tcx> ProjectionTy<'tcx> {
1883 pub fn sort_key(&self) -> (ast::DefId, ast::Name) {
1884 (self.trait_ref.def_id, self.item_name)
1888 pub trait ToPolyTraitRef<'tcx> {
1889 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx>;
1892 impl<'tcx> ToPolyTraitRef<'tcx> for Rc<TraitRef<'tcx>> {
1893 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1894 assert!(!self.has_escaping_regions());
1895 ty::Binder(self.clone())
1899 impl<'tcx> ToPolyTraitRef<'tcx> for PolyTraitPredicate<'tcx> {
1900 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1901 // We are just preserving the binder levels here
1902 ty::Binder(self.0.trait_ref.clone())
1906 impl<'tcx> ToPolyTraitRef<'tcx> for PolyProjectionPredicate<'tcx> {
1907 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1908 // Note: unlike with TraitRef::to_poly_trait_ref(),
1909 // self.0.trait_ref is permitted to have escaping regions.
1910 // This is because here `self` has a `Binder` and so does our
1911 // return value, so we are preserving the number of binding
1913 ty::Binder(self.0.projection_ty.trait_ref.clone())
1917 pub trait AsPredicate<'tcx> {
1918 fn as_predicate(&self) -> Predicate<'tcx>;
1921 impl<'tcx> AsPredicate<'tcx> for Rc<TraitRef<'tcx>> {
1922 fn as_predicate(&self) -> Predicate<'tcx> {
1923 // we're about to add a binder, so let's check that we don't
1924 // accidentally capture anything, or else that might be some
1925 // weird debruijn accounting.
1926 assert!(!self.has_escaping_regions());
1928 ty::Predicate::Trait(ty::Binder(ty::TraitPredicate {
1929 trait_ref: self.clone()
1934 impl<'tcx> AsPredicate<'tcx> for PolyTraitRef<'tcx> {
1935 fn as_predicate(&self) -> Predicate<'tcx> {
1936 ty::Predicate::Trait(self.to_poly_trait_predicate())
1940 impl<'tcx> AsPredicate<'tcx> for PolyEquatePredicate<'tcx> {
1941 fn as_predicate(&self) -> Predicate<'tcx> {
1942 Predicate::Equate(self.clone())
1946 impl<'tcx> AsPredicate<'tcx> for PolyRegionOutlivesPredicate {
1947 fn as_predicate(&self) -> Predicate<'tcx> {
1948 Predicate::RegionOutlives(self.clone())
1952 impl<'tcx> AsPredicate<'tcx> for PolyTypeOutlivesPredicate<'tcx> {
1953 fn as_predicate(&self) -> Predicate<'tcx> {
1954 Predicate::TypeOutlives(self.clone())
1958 impl<'tcx> AsPredicate<'tcx> for PolyProjectionPredicate<'tcx> {
1959 fn as_predicate(&self) -> Predicate<'tcx> {
1960 Predicate::Projection(self.clone())
1964 impl<'tcx> Predicate<'tcx> {
1965 pub fn has_escaping_regions(&self) -> bool {
1967 Predicate::Trait(ref trait_ref) => trait_ref.has_escaping_regions(),
1968 Predicate::Equate(ref p) => p.has_escaping_regions(),
1969 Predicate::RegionOutlives(ref p) => p.has_escaping_regions(),
1970 Predicate::TypeOutlives(ref p) => p.has_escaping_regions(),
1971 Predicate::Projection(ref p) => p.has_escaping_regions(),
1975 pub fn to_opt_poly_trait_ref(&self) -> Option<PolyTraitRef<'tcx>> {
1977 Predicate::Trait(ref t) => {
1978 Some(t.to_poly_trait_ref())
1980 Predicate::Projection(..) |
1981 Predicate::Equate(..) |
1982 Predicate::RegionOutlives(..) |
1983 Predicate::TypeOutlives(..) => {
1990 /// Represents the bounds declared on a particular set of type
1991 /// parameters. Should eventually be generalized into a flag list of
1992 /// where clauses. You can obtain a `GenericBounds` list from a
1993 /// `Generics` by using the `to_bounds` method. Note that this method
1994 /// reflects an important semantic invariant of `GenericBounds`: while
1995 /// the bounds in a `Generics` are expressed in terms of the bound type
1996 /// parameters of the impl/trait/whatever, a `GenericBounds` instance
1997 /// represented a set of bounds for some particular instantiation,
1998 /// meaning that the generic parameters have been substituted with
2003 /// struct Foo<T,U:Bar<T>> { ... }
2005 /// Here, the `Generics` for `Foo` would contain a list of bounds like
2006 /// `[[], [U:Bar<T>]]`. Now if there were some particular reference
2007 /// like `Foo<int,uint>`, then the `GenericBounds` would be `[[],
2008 /// [uint:Bar<int>]]`.
2009 #[derive(Clone, Show)]
2010 pub struct GenericBounds<'tcx> {
2011 pub predicates: VecPerParamSpace<Predicate<'tcx>>,
2014 impl<'tcx> GenericBounds<'tcx> {
2015 pub fn empty() -> GenericBounds<'tcx> {
2016 GenericBounds { predicates: VecPerParamSpace::empty() }
2019 pub fn has_escaping_regions(&self) -> bool {
2020 self.predicates.any(|p| p.has_escaping_regions())
2023 pub fn is_empty(&self) -> bool {
2024 self.predicates.is_empty()
2028 impl<'tcx> TraitRef<'tcx> {
2029 pub fn new(def_id: ast::DefId, substs: &'tcx Substs<'tcx>) -> TraitRef<'tcx> {
2030 TraitRef { def_id: def_id, substs: substs }
2033 pub fn self_ty(&self) -> Ty<'tcx> {
2034 self.substs.self_ty().unwrap()
2037 pub fn input_types(&self) -> &[Ty<'tcx>] {
2038 // Select only the "input types" from a trait-reference. For
2039 // now this is all the types that appear in the
2040 // trait-reference, but it should eventually exclude
2041 // associated types.
2042 self.substs.types.as_slice()
2046 /// When type checking, we use the `ParameterEnvironment` to track
2047 /// details about the type/lifetime parameters that are in scope.
2048 /// It primarily stores the bounds information.
2050 /// Note: This information might seem to be redundant with the data in
2051 /// `tcx.ty_param_defs`, but it is not. That table contains the
2052 /// parameter definitions from an "outside" perspective, but this
2053 /// struct will contain the bounds for a parameter as seen from inside
2054 /// the function body. Currently the only real distinction is that
2055 /// bound lifetime parameters are replaced with free ones, but in the
2056 /// future I hope to refine the representation of types so as to make
2057 /// more distinctions clearer.
2059 pub struct ParameterEnvironment<'a, 'tcx:'a> {
2060 pub tcx: &'a ctxt<'tcx>,
2062 /// A substitution that can be applied to move from
2063 /// the "outer" view of a type or method to the "inner" view.
2064 /// In general, this means converting from bound parameters to
2065 /// free parameters. Since we currently represent bound/free type
2066 /// parameters in the same way, this only has an effect on regions.
2067 pub free_substs: Substs<'tcx>,
2069 /// Each type parameter has an implicit region bound that
2070 /// indicates it must outlive at least the function body (the user
2071 /// may specify stronger requirements). This field indicates the
2072 /// region of the callee.
2073 pub implicit_region_bound: ty::Region,
2075 /// Obligations that the caller must satisfy. This is basically
2076 /// the set of bounds on the in-scope type parameters, translated
2077 /// into Obligations.
2078 pub caller_bounds: ty::GenericBounds<'tcx>,
2080 /// Caches the results of trait selection. This cache is used
2081 /// for things that have to do with the parameters in scope.
2082 pub selection_cache: traits::SelectionCache<'tcx>,
2085 impl<'a, 'tcx> ParameterEnvironment<'a, 'tcx> {
2086 pub fn for_item(cx: &'a ctxt<'tcx>, id: NodeId) -> ParameterEnvironment<'a, 'tcx> {
2087 match cx.map.find(id) {
2088 Some(ast_map::NodeImplItem(ref impl_item)) => {
2090 ast::MethodImplItem(ref method) => {
2091 let method_def_id = ast_util::local_def(id);
2092 match ty::impl_or_trait_item(cx, method_def_id) {
2093 MethodTraitItem(ref method_ty) => {
2094 let method_generics = &method_ty.generics;
2095 construct_parameter_environment(
2098 method.pe_body().id)
2100 TypeTraitItem(_) => {
2102 .bug("ParameterEnvironment::for_item(): \
2103 can't create a parameter environment \
2104 for type trait items")
2108 ast::TypeImplItem(_) => {
2109 cx.sess.bug("ParameterEnvironment::for_item(): \
2110 can't create a parameter environment \
2111 for type impl items")
2115 Some(ast_map::NodeTraitItem(trait_method)) => {
2116 match *trait_method {
2117 ast::RequiredMethod(ref required) => {
2118 cx.sess.span_bug(required.span,
2119 "ParameterEnvironment::for_item():
2120 can't create a parameter \
2121 environment for required trait \
2124 ast::ProvidedMethod(ref method) => {
2125 let method_def_id = ast_util::local_def(id);
2126 match ty::impl_or_trait_item(cx, method_def_id) {
2127 MethodTraitItem(ref method_ty) => {
2128 let method_generics = &method_ty.generics;
2129 construct_parameter_environment(
2132 method.pe_body().id)
2134 TypeTraitItem(_) => {
2136 .bug("ParameterEnvironment::for_item(): \
2137 can't create a parameter environment \
2138 for type trait items")
2142 ast::TypeTraitItem(_) => {
2143 cx.sess.bug("ParameterEnvironment::from_item(): \
2144 can't create a parameter environment \
2145 for type trait items")
2149 Some(ast_map::NodeItem(item)) => {
2151 ast::ItemFn(_, _, _, _, ref body) => {
2152 // We assume this is a function.
2153 let fn_def_id = ast_util::local_def(id);
2154 let fn_pty = ty::lookup_item_type(cx, fn_def_id);
2156 construct_parameter_environment(cx,
2161 ast::ItemStruct(..) |
2163 ast::ItemConst(..) |
2164 ast::ItemStatic(..) => {
2165 let def_id = ast_util::local_def(id);
2166 let pty = ty::lookup_item_type(cx, def_id);
2167 construct_parameter_environment(cx, &pty.generics, id)
2170 cx.sess.span_bug(item.span,
2171 "ParameterEnvironment::from_item():
2172 can't create a parameter \
2173 environment for this kind of item")
2177 Some(ast_map::NodeExpr(..)) => {
2178 // This is a convenience to allow closures to work.
2179 ParameterEnvironment::for_item(cx, cx.map.get_parent(id))
2182 cx.sess.bug(format!("ParameterEnvironment::from_item(): \
2183 `{}` is not an item",
2184 cx.map.node_to_string(id))[])
2190 /// A "type scheme", in ML terminology, is a type combined with some
2191 /// set of generic types that the type is, well, generic over. In Rust
2192 /// terms, it is the "type" of a fn item or struct -- this type will
2193 /// include various generic parameters that must be substituted when
2194 /// the item/struct is referenced. That is called converting the type
2195 /// scheme to a monotype.
2197 /// - `generics`: the set of type parameters and their bounds
2198 /// - `ty`: the base types, which may reference the parameters defined
2201 /// Note that TypeSchemes are also sometimes called "polytypes" (and
2202 /// in fact this struct used to carry that name, so you may find some
2203 /// stray references in a comment or something). We try to reserve the
2204 /// "poly" prefix to refer to higher-ranked things, as in
2206 #[derive(Clone, Show)]
2207 pub struct TypeScheme<'tcx> {
2208 pub generics: Generics<'tcx>,
2212 /// As `TypeScheme` but for a trait ref.
2213 pub struct TraitDef<'tcx> {
2214 pub unsafety: ast::Unsafety,
2216 /// Generic type definitions. Note that `Self` is listed in here
2217 /// as having a single bound, the trait itself (e.g., in the trait
2218 /// `Eq`, there is a single bound `Self : Eq`). This is so that
2219 /// default methods get to assume that the `Self` parameters
2220 /// implements the trait.
2221 pub generics: Generics<'tcx>,
2223 /// The "supertrait" bounds.
2224 pub bounds: ParamBounds<'tcx>,
2226 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
2228 /// A list of the associated types defined in this trait. Useful
2229 /// for resolving `X::Foo` type markers.
2230 pub associated_type_names: Vec<ast::Name>,
2233 /// Records the substitutions used to translate the polytype for an
2234 /// item into the monotype of an item reference.
2236 pub struct ItemSubsts<'tcx> {
2237 pub substs: Substs<'tcx>,
2240 /// Records information about each unboxed closure.
2242 pub struct UnboxedClosure<'tcx> {
2243 /// The type of the unboxed closure.
2244 pub closure_type: ClosureTy<'tcx>,
2245 /// The kind of unboxed closure this is.
2246 pub kind: UnboxedClosureKind,
2249 #[derive(Clone, Copy, PartialEq, Eq, Show)]
2250 pub enum UnboxedClosureKind {
2251 FnUnboxedClosureKind,
2252 FnMutUnboxedClosureKind,
2253 FnOnceUnboxedClosureKind,
2256 impl UnboxedClosureKind {
2257 pub fn trait_did(&self, cx: &ctxt) -> ast::DefId {
2258 let result = match *self {
2259 FnUnboxedClosureKind => cx.lang_items.require(FnTraitLangItem),
2260 FnMutUnboxedClosureKind => {
2261 cx.lang_items.require(FnMutTraitLangItem)
2263 FnOnceUnboxedClosureKind => {
2264 cx.lang_items.require(FnOnceTraitLangItem)
2268 Ok(trait_did) => trait_did,
2269 Err(err) => cx.sess.fatal(err[]),
2274 pub trait UnboxedClosureTyper<'tcx> {
2275 fn param_env<'a>(&'a self) -> &'a ty::ParameterEnvironment<'a, 'tcx>;
2277 fn unboxed_closure_kind(&self,
2279 -> ty::UnboxedClosureKind;
2281 fn unboxed_closure_type(&self,
2283 substs: &subst::Substs<'tcx>)
2284 -> ty::ClosureTy<'tcx>;
2286 // Returns `None` if the upvar types cannot yet be definitively determined.
2287 fn unboxed_closure_upvars(&self,
2289 substs: &Substs<'tcx>)
2290 -> Option<Vec<UnboxedClosureUpvar<'tcx>>>;
2293 impl<'tcx> CommonTypes<'tcx> {
2294 fn new(arena: &'tcx TypedArena<TyS<'tcx>>,
2295 interner: &mut FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>)
2296 -> CommonTypes<'tcx>
2299 bool: intern_ty(arena, interner, ty_bool),
2300 char: intern_ty(arena, interner, ty_char),
2301 err: intern_ty(arena, interner, ty_err),
2302 int: intern_ty(arena, interner, ty_int(ast::TyI)),
2303 i8: intern_ty(arena, interner, ty_int(ast::TyI8)),
2304 i16: intern_ty(arena, interner, ty_int(ast::TyI16)),
2305 i32: intern_ty(arena, interner, ty_int(ast::TyI32)),
2306 i64: intern_ty(arena, interner, ty_int(ast::TyI64)),
2307 uint: intern_ty(arena, interner, ty_uint(ast::TyU)),
2308 u8: intern_ty(arena, interner, ty_uint(ast::TyU8)),
2309 u16: intern_ty(arena, interner, ty_uint(ast::TyU16)),
2310 u32: intern_ty(arena, interner, ty_uint(ast::TyU32)),
2311 u64: intern_ty(arena, interner, ty_uint(ast::TyU64)),
2312 f32: intern_ty(arena, interner, ty_float(ast::TyF32)),
2313 f64: intern_ty(arena, interner, ty_float(ast::TyF64)),
2318 pub fn mk_ctxt<'tcx>(s: Session,
2319 arenas: &'tcx CtxtArenas<'tcx>,
2321 named_region_map: resolve_lifetime::NamedRegionMap,
2322 map: ast_map::Map<'tcx>,
2323 freevars: RefCell<FreevarMap>,
2324 capture_modes: RefCell<CaptureModeMap>,
2325 region_maps: middle::region::RegionMaps,
2326 lang_items: middle::lang_items::LanguageItems,
2327 stability: stability::Index) -> ctxt<'tcx>
2329 let mut interner = FnvHashMap::new();
2330 let common_types = CommonTypes::new(&arenas.type_, &mut interner);
2334 interner: RefCell::new(interner),
2335 substs_interner: RefCell::new(FnvHashMap::new()),
2336 bare_fn_interner: RefCell::new(FnvHashMap::new()),
2337 region_interner: RefCell::new(FnvHashMap::new()),
2338 types: common_types,
2339 named_region_map: named_region_map,
2340 item_variance_map: RefCell::new(DefIdMap::new()),
2341 variance_computed: Cell::new(false),
2344 region_maps: region_maps,
2345 node_types: RefCell::new(FnvHashMap::new()),
2346 item_substs: RefCell::new(NodeMap::new()),
2347 trait_refs: RefCell::new(NodeMap::new()),
2348 trait_defs: RefCell::new(DefIdMap::new()),
2349 object_cast_map: RefCell::new(NodeMap::new()),
2351 intrinsic_defs: RefCell::new(DefIdMap::new()),
2353 tcache: RefCell::new(DefIdMap::new()),
2354 rcache: RefCell::new(FnvHashMap::new()),
2355 short_names_cache: RefCell::new(FnvHashMap::new()),
2356 tc_cache: RefCell::new(FnvHashMap::new()),
2357 ast_ty_to_ty_cache: RefCell::new(NodeMap::new()),
2358 enum_var_cache: RefCell::new(DefIdMap::new()),
2359 impl_or_trait_items: RefCell::new(DefIdMap::new()),
2360 trait_item_def_ids: RefCell::new(DefIdMap::new()),
2361 trait_items_cache: RefCell::new(DefIdMap::new()),
2362 impl_trait_cache: RefCell::new(DefIdMap::new()),
2363 ty_param_defs: RefCell::new(NodeMap::new()),
2364 adjustments: RefCell::new(NodeMap::new()),
2365 normalized_cache: RefCell::new(FnvHashMap::new()),
2366 lang_items: lang_items,
2367 provided_method_sources: RefCell::new(DefIdMap::new()),
2368 struct_fields: RefCell::new(DefIdMap::new()),
2369 destructor_for_type: RefCell::new(DefIdMap::new()),
2370 destructors: RefCell::new(DefIdSet::new()),
2371 trait_impls: RefCell::new(DefIdMap::new()),
2372 inherent_impls: RefCell::new(DefIdMap::new()),
2373 impl_items: RefCell::new(DefIdMap::new()),
2374 used_unsafe: RefCell::new(NodeSet::new()),
2375 used_mut_nodes: RefCell::new(NodeSet::new()),
2376 populated_external_types: RefCell::new(DefIdSet::new()),
2377 populated_external_traits: RefCell::new(DefIdSet::new()),
2378 upvar_borrow_map: RefCell::new(FnvHashMap::new()),
2379 extern_const_statics: RefCell::new(DefIdMap::new()),
2380 extern_const_variants: RefCell::new(DefIdMap::new()),
2381 method_map: RefCell::new(FnvHashMap::new()),
2382 dependency_formats: RefCell::new(FnvHashMap::new()),
2383 unboxed_closures: RefCell::new(DefIdMap::new()),
2384 node_lint_levels: RefCell::new(FnvHashMap::new()),
2385 transmute_restrictions: RefCell::new(Vec::new()),
2386 stability: RefCell::new(stability),
2387 capture_modes: capture_modes,
2388 associated_types: RefCell::new(DefIdMap::new()),
2389 selection_cache: traits::SelectionCache::new(),
2390 repr_hint_cache: RefCell::new(DefIdMap::new()),
2391 type_impls_copy_cache: RefCell::new(HashMap::new()),
2392 type_impls_sized_cache: RefCell::new(HashMap::new()),
2393 object_safety_cache: RefCell::new(DefIdMap::new()),
2397 // Type constructors
2399 impl<'tcx> ctxt<'tcx> {
2400 pub fn mk_substs(&self, substs: Substs<'tcx>) -> &'tcx Substs<'tcx> {
2401 if let Some(substs) = self.substs_interner.borrow().get(&substs) {
2405 let substs = self.arenas.substs.alloc(substs);
2406 self.substs_interner.borrow_mut().insert(substs, substs);
2410 pub fn mk_bare_fn(&self, bare_fn: BareFnTy<'tcx>) -> &'tcx BareFnTy<'tcx> {
2411 if let Some(bare_fn) = self.bare_fn_interner.borrow().get(&bare_fn) {
2415 let bare_fn = self.arenas.bare_fn.alloc(bare_fn);
2416 self.bare_fn_interner.borrow_mut().insert(bare_fn, bare_fn);
2420 pub fn mk_region(&self, region: Region) -> &'tcx Region {
2421 if let Some(region) = self.region_interner.borrow().get(®ion) {
2425 let region = self.arenas.region.alloc(region);
2426 self.region_interner.borrow_mut().insert(region, region);
2430 pub fn unboxed_closure_kind(&self,
2432 -> ty::UnboxedClosureKind
2434 self.unboxed_closures.borrow()[def_id].kind
2437 pub fn unboxed_closure_type(&self,
2439 substs: &subst::Substs<'tcx>)
2440 -> ty::ClosureTy<'tcx>
2442 self.unboxed_closures.borrow()[def_id].closure_type.subst(self, substs)
2446 // Interns a type/name combination, stores the resulting box in cx.interner,
2447 // and returns the box as cast to an unsafe ptr (see comments for Ty above).
2448 pub fn mk_t<'tcx>(cx: &ctxt<'tcx>, st: sty<'tcx>) -> Ty<'tcx> {
2449 let mut interner = cx.interner.borrow_mut();
2450 intern_ty(&cx.arenas.type_, &mut *interner, st)
2453 fn intern_ty<'tcx>(type_arena: &'tcx TypedArena<TyS<'tcx>>,
2454 interner: &mut FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>,
2458 match interner.get(&st) {
2459 Some(ty) => return *ty,
2463 let flags = FlagComputation::for_sty(&st);
2465 let ty = type_arena.alloc(TyS {
2468 region_depth: flags.depth,
2471 debug!("Interned type: {} Pointer: {}",
2472 ty, ty as *const _);
2474 interner.insert(InternedTy { ty: ty }, ty);
2479 struct FlagComputation {
2482 // maximum depth of any bound region that we have seen thus far
2486 impl FlagComputation {
2487 fn new() -> FlagComputation {
2488 FlagComputation { flags: NO_TYPE_FLAGS, depth: 0 }
2491 fn for_sty(st: &sty) -> FlagComputation {
2492 let mut result = FlagComputation::new();
2497 fn add_flags(&mut self, flags: TypeFlags) {
2498 self.flags = self.flags | flags;
2501 fn add_depth(&mut self, depth: u32) {
2502 if depth > self.depth {
2507 /// Adds the flags/depth from a set of types that appear within the current type, but within a
2509 fn add_bound_computation(&mut self, computation: &FlagComputation) {
2510 self.add_flags(computation.flags);
2512 // The types that contributed to `computation` occured within
2513 // a region binder, so subtract one from the region depth
2514 // within when adding the depth to `self`.
2515 let depth = computation.depth;
2517 self.add_depth(depth - 1);
2521 fn add_sty(&mut self, st: &sty) {
2531 // You might think that we could just return ty_err for
2532 // any type containing ty_err as a component, and get
2533 // rid of the HAS_TY_ERR flag -- likewise for ty_bot (with
2534 // the exception of function types that return bot).
2535 // But doing so caused sporadic memory corruption, and
2536 // neither I (tjc) nor nmatsakis could figure out why,
2537 // so we're doing it this way.
2539 self.add_flags(HAS_TY_ERR)
2542 &ty_param(ref p) => {
2543 if p.space == subst::SelfSpace {
2544 self.add_flags(HAS_SELF);
2546 self.add_flags(HAS_PARAMS);
2550 &ty_unboxed_closure(_, region, substs) => {
2551 self.add_region(*region);
2552 self.add_substs(substs);
2556 self.add_flags(HAS_TY_INFER)
2559 &ty_enum(_, substs) | &ty_struct(_, substs) => {
2560 self.add_substs(substs);
2563 &ty_projection(ref data) => {
2564 self.add_flags(HAS_PROJECTION);
2565 self.add_substs(data.trait_ref.substs);
2568 &ty_trait(box TyTrait { ref principal, ref bounds }) => {
2569 let mut computation = FlagComputation::new();
2570 computation.add_substs(principal.0.substs);
2571 self.add_bound_computation(&computation);
2573 self.add_bounds(bounds);
2576 &ty_uniq(tt) | &ty_vec(tt, _) | &ty_open(tt) => {
2584 &ty_rptr(r, ref m) => {
2585 self.add_region(*r);
2589 &ty_tup(ref ts) => {
2593 &ty_bare_fn(_, ref f) => {
2594 self.add_fn_sig(&f.sig);
2599 fn add_ty(&mut self, ty: Ty) {
2600 self.add_flags(ty.flags);
2601 self.add_depth(ty.region_depth);
2604 fn add_tys(&mut self, tys: &[Ty]) {
2605 for &ty in tys.iter() {
2610 fn add_fn_sig(&mut self, fn_sig: &PolyFnSig) {
2611 let mut computation = FlagComputation::new();
2613 computation.add_tys(fn_sig.0.inputs[]);
2615 if let ty::FnConverging(output) = fn_sig.0.output {
2616 computation.add_ty(output);
2619 self.add_bound_computation(&computation);
2622 fn add_region(&mut self, r: Region) {
2623 self.add_flags(HAS_REGIONS);
2625 ty::ReInfer(_) => { self.add_flags(HAS_RE_INFER); }
2626 ty::ReLateBound(debruijn, _) => {
2627 self.add_flags(HAS_RE_LATE_BOUND);
2628 self.add_depth(debruijn.depth);
2634 fn add_substs(&mut self, substs: &Substs) {
2635 self.add_tys(substs.types.as_slice());
2636 match substs.regions {
2637 subst::ErasedRegions => {}
2638 subst::NonerasedRegions(ref regions) => {
2639 for &r in regions.iter() {
2646 fn add_bounds(&mut self, bounds: &ExistentialBounds) {
2647 self.add_region(bounds.region_bound);
2651 pub fn mk_mach_int<'tcx>(tcx: &ctxt<'tcx>, tm: ast::IntTy) -> Ty<'tcx> {
2653 ast::TyI => tcx.types.int,
2654 ast::TyI8 => tcx.types.i8,
2655 ast::TyI16 => tcx.types.i16,
2656 ast::TyI32 => tcx.types.i32,
2657 ast::TyI64 => tcx.types.i64,
2661 pub fn mk_mach_uint<'tcx>(tcx: &ctxt<'tcx>, tm: ast::UintTy) -> Ty<'tcx> {
2663 ast::TyU => tcx.types.uint,
2664 ast::TyU8 => tcx.types.u8,
2665 ast::TyU16 => tcx.types.u16,
2666 ast::TyU32 => tcx.types.u32,
2667 ast::TyU64 => tcx.types.u64,
2671 pub fn mk_mach_float<'tcx>(tcx: &ctxt<'tcx>, tm: ast::FloatTy) -> Ty<'tcx> {
2673 ast::TyF32 => tcx.types.f32,
2674 ast::TyF64 => tcx.types.f64,
2678 pub fn mk_str<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2682 pub fn mk_str_slice<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, m: ast::Mutability) -> Ty<'tcx> {
2685 ty: mk_t(cx, ty_str),
2690 pub fn mk_enum<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId, substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
2691 // take a copy of substs so that we own the vectors inside
2692 mk_t(cx, ty_enum(did, substs))
2695 pub fn mk_uniq<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_uniq(ty)) }
2697 pub fn mk_ptr<'tcx>(cx: &ctxt<'tcx>, tm: mt<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_ptr(tm)) }
2699 pub fn mk_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, tm: mt<'tcx>) -> Ty<'tcx> {
2700 mk_t(cx, ty_rptr(r, tm))
2703 pub fn mk_mut_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
2704 mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutMutable})
2706 pub fn mk_imm_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
2707 mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutImmutable})
2710 pub fn mk_mut_ptr<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
2711 mk_ptr(cx, mt {ty: ty, mutbl: ast::MutMutable})
2714 pub fn mk_imm_ptr<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
2715 mk_ptr(cx, mt {ty: ty, mutbl: ast::MutImmutable})
2718 pub fn mk_nil_ptr<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2719 mk_ptr(cx, mt {ty: mk_nil(cx), mutbl: ast::MutImmutable})
2722 pub fn mk_vec<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>, sz: Option<uint>) -> Ty<'tcx> {
2723 mk_t(cx, ty_vec(ty, sz))
2726 pub fn mk_slice<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, tm: mt<'tcx>) -> Ty<'tcx> {
2729 ty: mk_vec(cx, tm.ty, None),
2734 pub fn mk_tup<'tcx>(cx: &ctxt<'tcx>, ts: Vec<Ty<'tcx>>) -> Ty<'tcx> {
2735 mk_t(cx, ty_tup(ts))
2738 pub fn mk_nil<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2739 mk_tup(cx, Vec::new())
2742 pub fn mk_closure<'tcx>(cx: &ctxt<'tcx>, fty: ClosureTy<'tcx>) -> Ty<'tcx> {
2746 pub fn mk_bare_fn<'tcx>(cx: &ctxt<'tcx>,
2747 opt_def_id: Option<ast::DefId>,
2748 fty: &'tcx BareFnTy<'tcx>) -> Ty<'tcx> {
2749 mk_t(cx, ty_bare_fn(opt_def_id, fty))
2752 pub fn mk_ctor_fn<'tcx>(cx: &ctxt<'tcx>,
2754 input_tys: &[Ty<'tcx>],
2755 output: Ty<'tcx>) -> Ty<'tcx> {
2756 let input_args = input_tys.iter().map(|ty| *ty).collect();
2759 cx.mk_bare_fn(BareFnTy {
2760 unsafety: ast::Unsafety::Normal,
2762 sig: ty::Binder(FnSig {
2764 output: ty::FnConverging(output),
2770 pub fn mk_trait<'tcx>(cx: &ctxt<'tcx>,
2771 principal: ty::PolyTraitRef<'tcx>,
2772 bounds: ExistentialBounds<'tcx>)
2775 assert!(bound_list_is_sorted(bounds.projection_bounds.as_slice()));
2777 let inner = box TyTrait {
2778 principal: principal,
2781 mk_t(cx, ty_trait(inner))
2784 fn bound_list_is_sorted(bounds: &[ty::PolyProjectionPredicate]) -> bool {
2785 bounds.len() == 0 ||
2786 bounds[1..].iter().enumerate().all(
2787 |(index, bound)| bounds[index].sort_key() <= bound.sort_key())
2790 pub fn sort_bounds_list(bounds: &mut [ty::PolyProjectionPredicate]) {
2791 bounds.sort_by(|a, b| a.sort_key().cmp(&b.sort_key()))
2794 pub fn mk_projection<'tcx>(cx: &ctxt<'tcx>,
2795 trait_ref: Rc<ty::TraitRef<'tcx>>,
2796 item_name: ast::Name)
2798 // take a copy of substs so that we own the vectors inside
2799 let inner = ProjectionTy { trait_ref: trait_ref, item_name: item_name };
2800 mk_t(cx, ty_projection(inner))
2803 pub fn mk_struct<'tcx>(cx: &ctxt<'tcx>, struct_id: ast::DefId,
2804 substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
2805 // take a copy of substs so that we own the vectors inside
2806 mk_t(cx, ty_struct(struct_id, substs))
2809 pub fn mk_unboxed_closure<'tcx>(cx: &ctxt<'tcx>, closure_id: ast::DefId,
2810 region: &'tcx Region, substs: &'tcx Substs<'tcx>)
2812 mk_t(cx, ty_unboxed_closure(closure_id, region, substs))
2815 pub fn mk_var<'tcx>(cx: &ctxt<'tcx>, v: TyVid) -> Ty<'tcx> {
2816 mk_infer(cx, TyVar(v))
2819 pub fn mk_int_var<'tcx>(cx: &ctxt<'tcx>, v: IntVid) -> Ty<'tcx> {
2820 mk_infer(cx, IntVar(v))
2823 pub fn mk_float_var<'tcx>(cx: &ctxt<'tcx>, v: FloatVid) -> Ty<'tcx> {
2824 mk_infer(cx, FloatVar(v))
2827 pub fn mk_infer<'tcx>(cx: &ctxt<'tcx>, it: InferTy) -> Ty<'tcx> {
2828 mk_t(cx, ty_infer(it))
2831 pub fn mk_param<'tcx>(cx: &ctxt<'tcx>,
2832 space: subst::ParamSpace,
2834 name: ast::Name) -> Ty<'tcx> {
2835 mk_t(cx, ty_param(ParamTy { space: space, idx: index, name: name }))
2838 pub fn mk_self_type<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2839 mk_param(cx, subst::SelfSpace, 0, special_idents::type_self.name)
2842 pub fn mk_param_from_def<'tcx>(cx: &ctxt<'tcx>, def: &TypeParameterDef) -> Ty<'tcx> {
2843 mk_param(cx, def.space, def.index, def.name)
2846 pub fn mk_open<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_open(ty)) }
2848 impl<'tcx> TyS<'tcx> {
2849 /// Iterator that walks `self` and any types reachable from
2850 /// `self`, in depth-first order. Note that just walks the types
2851 /// that appear in `self`, it does not descend into the fields of
2852 /// structs or variants. For example:
2856 /// Foo<Bar<int>> => { Foo<Bar<int>>, Bar<int>, int }
2857 /// [int] => { [int], int }
2859 pub fn walk(&'tcx self) -> TypeWalker<'tcx> {
2860 TypeWalker::new(self)
2863 /// Iterator that walks types reachable from `self`, in
2864 /// depth-first order. Note that this is a shallow walk. For
2869 /// Foo<Bar<int>> => { Bar<int>, int }
2870 /// [int] => { int }
2872 pub fn walk_children(&'tcx self) -> TypeWalker<'tcx> {
2873 // Walks type reachable from `self` but not `self
2874 let mut walker = self.walk();
2875 let r = walker.next();
2876 assert_eq!(r, Some(self));
2881 pub fn walk_ty<'tcx, F>(ty_root: Ty<'tcx>, mut f: F)
2882 where F: FnMut(Ty<'tcx>),
2884 for ty in ty_root.walk() {
2889 /// Walks `ty` and any types appearing within `ty`, invoking the
2890 /// callback `f` on each type. If the callback returns false, then the
2891 /// children of the current type are ignored.
2893 /// Note: prefer `ty.walk()` where possible.
2894 pub fn maybe_walk_ty<'tcx,F>(ty_root: Ty<'tcx>, mut f: F)
2895 where F : FnMut(Ty<'tcx>) -> bool
2897 let mut walker = ty_root.walk();
2898 while let Some(ty) = walker.next() {
2900 walker.skip_current_subtree();
2905 // Folds types from the bottom up.
2906 pub fn fold_ty<'tcx, F>(cx: &ctxt<'tcx>, t0: Ty<'tcx>,
2909 F: FnMut(Ty<'tcx>) -> Ty<'tcx>,
2911 let mut f = ty_fold::BottomUpFolder {tcx: cx, fldop: fldop};
2916 pub fn new(space: subst::ParamSpace,
2920 ParamTy { space: space, idx: index, name: name }
2923 pub fn for_self() -> ParamTy {
2924 ParamTy::new(subst::SelfSpace, 0, special_idents::type_self.name)
2927 pub fn for_def(def: &TypeParameterDef) -> ParamTy {
2928 ParamTy::new(def.space, def.index, def.name)
2931 pub fn to_ty<'tcx>(self, tcx: &ty::ctxt<'tcx>) -> Ty<'tcx> {
2932 ty::mk_param(tcx, self.space, self.idx, self.name)
2935 pub fn is_self(&self) -> bool {
2936 self.space == subst::SelfSpace && self.idx == 0
2940 impl<'tcx> ItemSubsts<'tcx> {
2941 pub fn empty() -> ItemSubsts<'tcx> {
2942 ItemSubsts { substs: Substs::empty() }
2945 pub fn is_noop(&self) -> bool {
2946 self.substs.is_noop()
2950 impl<'tcx> ParamBounds<'tcx> {
2951 pub fn empty() -> ParamBounds<'tcx> {
2953 builtin_bounds: empty_builtin_bounds(),
2954 trait_bounds: Vec::new(),
2955 region_bounds: Vec::new(),
2956 projection_bounds: Vec::new(),
2963 pub fn type_is_nil(ty: Ty) -> bool {
2965 ty_tup(ref tys) => tys.is_empty(),
2970 pub fn type_is_error(ty: Ty) -> bool {
2971 ty.flags.intersects(HAS_TY_ERR)
2974 pub fn type_needs_subst(ty: Ty) -> bool {
2975 ty.flags.intersects(NEEDS_SUBST)
2978 pub fn trait_ref_contains_error(tref: &ty::TraitRef) -> bool {
2979 tref.substs.types.any(|&ty| type_is_error(ty))
2982 pub fn type_is_ty_var(ty: Ty) -> bool {
2984 ty_infer(TyVar(_)) => true,
2989 pub fn type_is_bool(ty: Ty) -> bool { ty.sty == ty_bool }
2991 pub fn type_is_self(ty: Ty) -> bool {
2993 ty_param(ref p) => p.space == subst::SelfSpace,
2998 fn type_is_slice(ty: Ty) -> bool {
3000 ty_ptr(mt) | ty_rptr(_, mt) => match mt.ty.sty {
3001 ty_vec(_, None) | ty_str => true,
3008 pub fn type_is_vec(ty: Ty) -> bool {
3011 ty_ptr(mt{ty, ..}) | ty_rptr(_, mt{ty, ..}) |
3012 ty_uniq(ty) => match ty.sty {
3013 ty_vec(_, None) => true,
3020 pub fn type_is_structural(ty: Ty) -> bool {
3022 ty_struct(..) | ty_tup(_) | ty_enum(..) |
3023 ty_vec(_, Some(_)) | ty_unboxed_closure(..) => true,
3024 _ => type_is_slice(ty) | type_is_trait(ty)
3028 pub fn type_is_simd(cx: &ctxt, ty: Ty) -> bool {
3030 ty_struct(did, _) => lookup_simd(cx, did),
3035 pub fn sequence_element_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
3037 ty_vec(ty, _) => ty,
3038 ty_str => mk_mach_uint(cx, ast::TyU8),
3039 ty_open(ty) => sequence_element_type(cx, ty),
3040 _ => cx.sess.bug(format!("sequence_element_type called on non-sequence value: {}",
3041 ty_to_string(cx, ty))[]),
3045 pub fn simd_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
3047 ty_struct(did, substs) => {
3048 let fields = lookup_struct_fields(cx, did);
3049 lookup_field_type(cx, did, fields[0].id, substs)
3051 _ => panic!("simd_type called on invalid type")
3055 pub fn simd_size(cx: &ctxt, ty: Ty) -> uint {
3057 ty_struct(did, _) => {
3058 let fields = lookup_struct_fields(cx, did);
3061 _ => panic!("simd_size called on invalid type")
3065 pub fn type_is_region_ptr(ty: Ty) -> bool {
3067 ty_rptr(..) => true,
3072 pub fn type_is_unsafe_ptr(ty: Ty) -> bool {
3074 ty_ptr(_) => return true,
3079 pub fn type_is_unique(ty: Ty) -> bool {
3081 ty_uniq(_) => match ty.sty {
3082 ty_trait(..) => false,
3090 A scalar type is one that denotes an atomic datum, with no sub-components.
3091 (A ty_ptr is scalar because it represents a non-managed pointer, so its
3092 contents are abstract to rustc.)
3094 pub fn type_is_scalar(ty: Ty) -> bool {
3096 ty_bool | ty_char | ty_int(_) | ty_float(_) | ty_uint(_) |
3097 ty_infer(IntVar(_)) | ty_infer(FloatVar(_)) |
3098 ty_bare_fn(..) | ty_ptr(_) => true,
3099 ty_tup(ref tys) if tys.is_empty() => true,
3104 /// Returns true if this type is a floating point type and false otherwise.
3105 pub fn type_is_floating_point(ty: Ty) -> bool {
3107 ty_float(_) => true,
3112 /// Type contents is how the type checker reasons about kinds.
3113 /// They track what kinds of things are found within a type. You can
3114 /// think of them as kind of an "anti-kind". They track the kinds of values
3115 /// and thinks that are contained in types. Having a larger contents for
3116 /// a type tends to rule that type *out* from various kinds. For example,
3117 /// a type that contains a reference is not sendable.
3119 /// The reason we compute type contents and not kinds is that it is
3120 /// easier for me (nmatsakis) to think about what is contained within
3121 /// a type than to think about what is *not* contained within a type.
3122 #[derive(Clone, Copy)]
3123 pub struct TypeContents {
3127 macro_rules! def_type_content_sets {
3128 (mod $mname:ident { $($name:ident = $bits:expr),+ }) => {
3129 #[allow(non_snake_case)]
3131 use middle::ty::TypeContents;
3133 #[allow(non_upper_case_globals)]
3134 pub const $name: TypeContents = TypeContents { bits: $bits };
3140 def_type_content_sets! {
3142 None = 0b0000_0000__0000_0000__0000,
3144 // Things that are interior to the value (first nibble):
3145 InteriorUnsized = 0b0000_0000__0000_0000__0001,
3146 InteriorUnsafe = 0b0000_0000__0000_0000__0010,
3147 InteriorParam = 0b0000_0000__0000_0000__0100,
3148 // InteriorAll = 0b00000000__00000000__1111,
3150 // Things that are owned by the value (second and third nibbles):
3151 OwnsOwned = 0b0000_0000__0000_0001__0000,
3152 OwnsDtor = 0b0000_0000__0000_0010__0000,
3153 OwnsManaged /* see [1] below */ = 0b0000_0000__0000_0100__0000,
3154 OwnsAll = 0b0000_0000__1111_1111__0000,
3156 // Things that are reachable by the value in any way (fourth nibble):
3157 ReachesBorrowed = 0b0000_0010__0000_0000__0000,
3158 // ReachesManaged /* see [1] below */ = 0b0000_0100__0000_0000__0000,
3159 ReachesMutable = 0b0000_1000__0000_0000__0000,
3160 ReachesFfiUnsafe = 0b0010_0000__0000_0000__0000,
3161 ReachesAll = 0b0011_1111__0000_0000__0000,
3163 // Things that mean drop glue is necessary
3164 NeedsDrop = 0b0000_0000__0000_0111__0000,
3166 // Things that prevent values from being considered sized
3167 Nonsized = 0b0000_0000__0000_0000__0001,
3169 // Bits to set when a managed value is encountered
3171 // [1] Do not set the bits TC::OwnsManaged or
3172 // TC::ReachesManaged directly, instead reference
3173 // TC::Managed to set them both at once.
3174 Managed = 0b0000_0100__0000_0100__0000,
3177 All = 0b1111_1111__1111_1111__1111
3182 pub fn when(&self, cond: bool) -> TypeContents {
3183 if cond {*self} else {TC::None}
3186 pub fn intersects(&self, tc: TypeContents) -> bool {
3187 (self.bits & tc.bits) != 0
3190 pub fn owns_managed(&self) -> bool {
3191 self.intersects(TC::OwnsManaged)
3194 pub fn owns_owned(&self) -> bool {
3195 self.intersects(TC::OwnsOwned)
3198 pub fn is_sized(&self, _: &ctxt) -> bool {
3199 !self.intersects(TC::Nonsized)
3202 pub fn interior_param(&self) -> bool {
3203 self.intersects(TC::InteriorParam)
3206 pub fn interior_unsafe(&self) -> bool {
3207 self.intersects(TC::InteriorUnsafe)
3210 pub fn interior_unsized(&self) -> bool {
3211 self.intersects(TC::InteriorUnsized)
3214 pub fn needs_drop(&self, _: &ctxt) -> bool {
3215 self.intersects(TC::NeedsDrop)
3218 /// Includes only those bits that still apply when indirected through a `Box` pointer
3219 pub fn owned_pointer(&self) -> TypeContents {
3221 *self & (TC::OwnsAll | TC::ReachesAll))
3224 /// Includes only those bits that still apply when indirected through a reference (`&`)
3225 pub fn reference(&self, bits: TypeContents) -> TypeContents {
3227 *self & TC::ReachesAll)
3230 /// Includes only those bits that still apply when indirected through a managed pointer (`@`)
3231 pub fn managed_pointer(&self) -> TypeContents {
3233 *self & TC::ReachesAll)
3236 /// Includes only those bits that still apply when indirected through an unsafe pointer (`*`)
3237 pub fn unsafe_pointer(&self) -> TypeContents {
3238 *self & TC::ReachesAll
3241 pub fn union<T, F>(v: &[T], mut f: F) -> TypeContents where
3242 F: FnMut(&T) -> TypeContents,
3244 v.iter().fold(TC::None, |tc, ty| tc | f(ty))
3247 pub fn has_dtor(&self) -> bool {
3248 self.intersects(TC::OwnsDtor)
3252 impl ops::BitOr for TypeContents {
3253 type Output = TypeContents;
3255 fn bitor(self, other: TypeContents) -> TypeContents {
3256 TypeContents {bits: self.bits | other.bits}
3260 impl ops::BitAnd for TypeContents {
3261 type Output = TypeContents;
3263 fn bitand(self, other: TypeContents) -> TypeContents {
3264 TypeContents {bits: self.bits & other.bits}
3268 impl ops::Sub for TypeContents {
3269 type Output = TypeContents;
3271 fn sub(self, other: TypeContents) -> TypeContents {
3272 TypeContents {bits: self.bits & !other.bits}
3276 impl fmt::Show for TypeContents {
3277 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
3278 write!(f, "TypeContents({:b})", self.bits)
3282 pub fn type_interior_is_unsafe<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
3283 type_contents(cx, ty).interior_unsafe()
3286 pub fn type_contents<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> TypeContents {
3287 return memoized(&cx.tc_cache, ty, |ty| {
3288 tc_ty(cx, ty, &mut FnvHashMap::new())
3291 fn tc_ty<'tcx>(cx: &ctxt<'tcx>,
3293 cache: &mut FnvHashMap<Ty<'tcx>, TypeContents>) -> TypeContents
3295 // Subtle: Note that we are *not* using cx.tc_cache here but rather a
3296 // private cache for this walk. This is needed in the case of cyclic
3299 // struct List { next: Box<Option<List>>, ... }
3301 // When computing the type contents of such a type, we wind up deeply
3302 // recursing as we go. So when we encounter the recursive reference
3303 // to List, we temporarily use TC::None as its contents. Later we'll
3304 // patch up the cache with the correct value, once we've computed it
3305 // (this is basically a co-inductive process, if that helps). So in
3306 // the end we'll compute TC::OwnsOwned, in this case.
3308 // The problem is, as we are doing the computation, we will also
3309 // compute an *intermediate* contents for, e.g., Option<List> of
3310 // TC::None. This is ok during the computation of List itself, but if
3311 // we stored this intermediate value into cx.tc_cache, then later
3312 // requests for the contents of Option<List> would also yield TC::None
3313 // which is incorrect. This value was computed based on the crutch
3314 // value for the type contents of list. The correct value is
3315 // TC::OwnsOwned. This manifested as issue #4821.
3316 match cache.get(&ty) {
3317 Some(tc) => { return *tc; }
3320 match cx.tc_cache.borrow().get(&ty) { // Must check both caches!
3321 Some(tc) => { return *tc; }
3324 cache.insert(ty, TC::None);
3326 let result = match ty.sty {
3327 // uint and int are ffi-unsafe
3328 ty_uint(ast::TyU) | ty_int(ast::TyI) => {
3329 TC::ReachesFfiUnsafe
3332 // Scalar and unique types are sendable, and durable
3333 ty_infer(ty::FreshIntTy(_)) |
3334 ty_bool | ty_int(_) | ty_uint(_) | ty_float(_) |
3335 ty_bare_fn(..) | ty::ty_char => {
3340 TC::ReachesFfiUnsafe | match typ.sty {
3341 ty_str => TC::OwnsOwned,
3342 _ => tc_ty(cx, typ, cache).owned_pointer(),
3346 ty_trait(box TyTrait { ref bounds, .. }) => {
3347 object_contents(bounds) | TC::ReachesFfiUnsafe | TC::Nonsized
3351 tc_ty(cx, mt.ty, cache).unsafe_pointer()
3354 ty_rptr(r, ref mt) => {
3355 TC::ReachesFfiUnsafe | match mt.ty.sty {
3356 ty_str => borrowed_contents(*r, ast::MutImmutable),
3357 ty_vec(..) => tc_ty(cx, mt.ty, cache).reference(borrowed_contents(*r,
3359 _ => tc_ty(cx, mt.ty, cache).reference(borrowed_contents(*r, mt.mutbl)),
3363 ty_vec(ty, Some(_)) => {
3364 tc_ty(cx, ty, cache)
3367 ty_vec(ty, None) => {
3368 tc_ty(cx, ty, cache) | TC::Nonsized
3370 ty_str => TC::Nonsized,
3372 ty_struct(did, substs) => {
3373 let flds = struct_fields(cx, did, substs);
3375 TypeContents::union(flds[],
3376 |f| tc_mt(cx, f.mt, cache));
3378 if !lookup_repr_hints(cx, did).contains(&attr::ReprExtern) {
3379 res = res | TC::ReachesFfiUnsafe;
3382 if ty::has_dtor(cx, did) {
3383 res = res | TC::OwnsDtor;
3385 apply_lang_items(cx, did, res)
3388 ty_unboxed_closure(did, r, substs) => {
3389 // FIXME(#14449): `borrowed_contents` below assumes `&mut`
3391 let param_env = ty::empty_parameter_environment(cx);
3392 let upvars = unboxed_closure_upvars(¶m_env, did, substs).unwrap();
3393 TypeContents::union(upvars.as_slice(),
3394 |f| tc_ty(cx, f.ty, cache))
3395 | borrowed_contents(*r, MutMutable)
3398 ty_tup(ref tys) => {
3399 TypeContents::union(tys[],
3400 |ty| tc_ty(cx, *ty, cache))
3403 ty_enum(did, substs) => {
3404 let variants = substd_enum_variants(cx, did, substs);
3406 TypeContents::union(variants[], |variant| {
3407 TypeContents::union(variant.args[],
3409 tc_ty(cx, *arg_ty, cache)
3413 if ty::has_dtor(cx, did) {
3414 res = res | TC::OwnsDtor;
3417 if variants.len() != 0 {
3418 let repr_hints = lookup_repr_hints(cx, did);
3419 if repr_hints.len() > 1 {
3420 // this is an error later on, but this type isn't safe
3421 res = res | TC::ReachesFfiUnsafe;
3424 match repr_hints.get(0) {
3425 Some(h) => if !h.is_ffi_safe() {
3426 res = res | TC::ReachesFfiUnsafe;
3430 res = res | TC::ReachesFfiUnsafe;
3432 // We allow ReprAny enums if they are eligible for
3433 // the nullable pointer optimization and the
3434 // contained type is an `extern fn`
3436 if variants.len() == 2 {
3437 let mut data_idx = 0;
3439 if variants[0].args.len() == 0 {
3443 if variants[data_idx].args.len() == 1 {
3444 match variants[data_idx].args[0].sty {
3445 ty_bare_fn(..) => { res = res - TC::ReachesFfiUnsafe; }
3455 apply_lang_items(cx, did, res)
3464 let result = tc_ty(cx, ty, cache);
3465 assert!(!result.is_sized(cx));
3466 result.unsafe_pointer() | TC::Nonsized
3471 cx.sess.bug("asked to compute contents of error type");
3475 cache.insert(ty, result);
3479 fn tc_mt<'tcx>(cx: &ctxt<'tcx>,
3481 cache: &mut FnvHashMap<Ty<'tcx>, TypeContents>) -> TypeContents
3483 let mc = TC::ReachesMutable.when(mt.mutbl == MutMutable);
3484 mc | tc_ty(cx, mt.ty, cache)
3487 fn apply_lang_items(cx: &ctxt, did: ast::DefId, tc: TypeContents)
3489 if Some(did) == cx.lang_items.managed_bound() {
3491 } else if Some(did) == cx.lang_items.unsafe_type() {
3492 tc | TC::InteriorUnsafe
3498 /// Type contents due to containing a reference with the region `region` and borrow kind `bk`
3499 fn borrowed_contents(region: ty::Region,
3500 mutbl: ast::Mutability)
3502 let b = match mutbl {
3503 ast::MutMutable => TC::ReachesMutable,
3504 ast::MutImmutable => TC::None,
3506 b | (TC::ReachesBorrowed).when(region != ty::ReStatic)
3509 fn closure_contents(cty: &ClosureTy) -> TypeContents {
3510 // Closure contents are just like trait contents, but with potentially
3512 let st = object_contents(&cty.bounds);
3514 let st = match cty.store {
3518 RegionTraitStore(r, mutbl) => {
3519 st.reference(borrowed_contents(r, mutbl))
3526 fn object_contents(bounds: &ExistentialBounds) -> TypeContents {
3527 // These are the type contents of the (opaque) interior. We
3528 // make no assumptions (other than that it cannot have an
3529 // in-scope type parameter within, which makes no sense).
3530 let mut tc = TC::All - TC::InteriorParam;
3531 for bound in bounds.builtin_bounds.iter() {
3532 tc = tc - match bound {
3533 BoundSync | BoundSend | BoundCopy => TC::None,
3534 BoundSized => TC::Nonsized,
3541 fn type_impls_bound<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3542 cache: &RefCell<HashMap<Ty<'tcx>,bool>>,
3544 bound: ty::BuiltinBound,
3548 assert!(!ty::type_needs_infer(ty));
3550 if !type_has_params(ty) && !type_has_self(ty) {
3551 match cache.borrow().get(&ty) {
3554 debug!("type_impls_bound({}, {}) = {} (cached)",
3555 ty.repr(param_env.tcx),
3563 let infcx = infer::new_infer_ctxt(param_env.tcx);
3565 let is_impld = traits::type_known_to_meet_builtin_bound(&infcx, param_env, ty, bound, span);
3567 debug!("type_impls_bound({}, {}) = {}",
3568 ty.repr(param_env.tcx),
3572 if !type_has_params(ty) && !type_has_self(ty) {
3573 let old_value = cache.borrow_mut().insert(ty, is_impld);
3574 assert!(old_value.is_none());
3580 pub fn type_moves_by_default<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3585 let tcx = param_env.tcx;
3586 !type_impls_bound(param_env, &tcx.type_impls_copy_cache, ty, ty::BoundCopy, span)
3589 pub fn type_is_sized<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3594 let tcx = param_env.tcx;
3595 type_impls_bound(param_env, &tcx.type_impls_sized_cache, ty, ty::BoundSized, span)
3598 pub fn is_ffi_safe<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
3599 !type_contents(cx, ty).intersects(TC::ReachesFfiUnsafe)
3602 // True if instantiating an instance of `r_ty` requires an instance of `r_ty`.
3603 pub fn is_instantiable<'tcx>(cx: &ctxt<'tcx>, r_ty: Ty<'tcx>) -> bool {
3604 fn type_requires<'tcx>(cx: &ctxt<'tcx>, seen: &mut Vec<DefId>,
3605 r_ty: Ty<'tcx>, ty: Ty<'tcx>) -> bool {
3606 debug!("type_requires({}, {})?",
3607 ::util::ppaux::ty_to_string(cx, r_ty),
3608 ::util::ppaux::ty_to_string(cx, ty));
3610 let r = r_ty == ty || subtypes_require(cx, seen, r_ty, ty);
3612 debug!("type_requires({}, {})? {}",
3613 ::util::ppaux::ty_to_string(cx, r_ty),
3614 ::util::ppaux::ty_to_string(cx, ty),
3619 fn subtypes_require<'tcx>(cx: &ctxt<'tcx>, seen: &mut Vec<DefId>,
3620 r_ty: Ty<'tcx>, ty: Ty<'tcx>) -> bool {
3621 debug!("subtypes_require({}, {})?",
3622 ::util::ppaux::ty_to_string(cx, r_ty),
3623 ::util::ppaux::ty_to_string(cx, ty));
3625 let r = match ty.sty {
3626 // fixed length vectors need special treatment compared to
3627 // normal vectors, since they don't necessarily have the
3628 // possibility to have length zero.
3629 ty_vec(_, Some(0)) => false, // don't need no contents
3630 ty_vec(ty, Some(_)) => type_requires(cx, seen, r_ty, ty),
3641 ty_vec(_, None) => {
3644 ty_uniq(typ) | ty_open(typ) => {
3645 type_requires(cx, seen, r_ty, typ)
3647 ty_rptr(_, ref mt) => {
3648 type_requires(cx, seen, r_ty, mt.ty)
3652 false // unsafe ptrs can always be NULL
3659 ty_struct(ref did, _) if seen.contains(did) => {
3663 ty_struct(did, substs) => {
3665 let fields = struct_fields(cx, did, substs);
3666 let r = fields.iter().any(|f| type_requires(cx, seen, r_ty, f.mt.ty));
3667 seen.pop().unwrap();
3673 ty_unboxed_closure(..) => {
3674 // this check is run on type definitions, so we don't expect to see
3675 // inference by-products or unboxed closure types
3676 cx.sess.bug(format!("requires check invoked on inapplicable type: {}", ty)[])
3680 ts.iter().any(|ty| type_requires(cx, seen, r_ty, *ty))
3683 ty_enum(ref did, _) if seen.contains(did) => {
3687 ty_enum(did, substs) => {
3689 let vs = enum_variants(cx, did);
3690 let r = !vs.is_empty() && vs.iter().all(|variant| {
3691 variant.args.iter().any(|aty| {
3692 let sty = aty.subst(cx, substs);
3693 type_requires(cx, seen, r_ty, sty)
3696 seen.pop().unwrap();
3701 debug!("subtypes_require({}, {})? {}",
3702 ::util::ppaux::ty_to_string(cx, r_ty),
3703 ::util::ppaux::ty_to_string(cx, ty),
3709 let mut seen = Vec::new();
3710 !subtypes_require(cx, &mut seen, r_ty, r_ty)
3713 /// Describes whether a type is representable. For types that are not
3714 /// representable, 'SelfRecursive' and 'ContainsRecursive' are used to
3715 /// distinguish between types that are recursive with themselves and types that
3716 /// contain a different recursive type. These cases can therefore be treated
3717 /// differently when reporting errors.
3719 /// The ordering of the cases is significant. They are sorted so that cmp::max
3720 /// will keep the "more erroneous" of two values.
3721 #[derive(Copy, PartialOrd, Ord, Eq, PartialEq, Show)]
3722 pub enum Representability {
3728 /// Check whether a type is representable. This means it cannot contain unboxed
3729 /// structural recursion. This check is needed for structs and enums.
3730 pub fn is_type_representable<'tcx>(cx: &ctxt<'tcx>, sp: Span, ty: Ty<'tcx>)
3731 -> Representability {
3733 // Iterate until something non-representable is found
3734 fn find_nonrepresentable<'tcx, It: Iterator<Item=Ty<'tcx>>>(cx: &ctxt<'tcx>, sp: Span,
3735 seen: &mut Vec<Ty<'tcx>>,
3737 -> Representability {
3738 iter.fold(Representable,
3739 |r, ty| cmp::max(r, is_type_structurally_recursive(cx, sp, seen, ty)))
3742 fn are_inner_types_recursive<'tcx>(cx: &ctxt<'tcx>, sp: Span,
3743 seen: &mut Vec<Ty<'tcx>>, ty: Ty<'tcx>)
3744 -> Representability {
3747 find_nonrepresentable(cx, sp, seen, ts.iter().map(|ty| *ty))
3749 // Fixed-length vectors.
3750 // FIXME(#11924) Behavior undecided for zero-length vectors.
3751 ty_vec(ty, Some(_)) => {
3752 is_type_structurally_recursive(cx, sp, seen, ty)
3754 ty_struct(did, substs) => {
3755 let fields = struct_fields(cx, did, substs);
3756 find_nonrepresentable(cx, sp, seen, fields.iter().map(|f| f.mt.ty))
3758 ty_enum(did, substs) => {
3759 let vs = enum_variants(cx, did);
3760 let iter = vs.iter()
3761 .flat_map(|variant| { variant.args.iter() })
3762 .map(|aty| { aty.subst_spanned(cx, substs, Some(sp)) });
3764 find_nonrepresentable(cx, sp, seen, iter)
3766 ty_unboxed_closure(..) => {
3767 // this check is run on type definitions, so we don't expect to see
3768 // unboxed closure types
3769 cx.sess.bug(format!("requires check invoked on inapplicable type: {}", ty)[])
3775 fn same_struct_or_enum_def_id(ty: Ty, did: DefId) -> bool {
3777 ty_struct(ty_did, _) | ty_enum(ty_did, _) => {
3784 fn same_type<'tcx>(a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
3785 match (&a.sty, &b.sty) {
3786 (&ty_struct(did_a, ref substs_a), &ty_struct(did_b, ref substs_b)) |
3787 (&ty_enum(did_a, ref substs_a), &ty_enum(did_b, ref substs_b)) => {
3792 let types_a = substs_a.types.get_slice(subst::TypeSpace);
3793 let types_b = substs_b.types.get_slice(subst::TypeSpace);
3795 let pairs = types_a.iter().zip(types_b.iter());
3797 pairs.all(|(&a, &b)| same_type(a, b))
3805 // Does the type `ty` directly (without indirection through a pointer)
3806 // contain any types on stack `seen`?
3807 fn is_type_structurally_recursive<'tcx>(cx: &ctxt<'tcx>, sp: Span,
3808 seen: &mut Vec<Ty<'tcx>>,
3809 ty: Ty<'tcx>) -> Representability {
3810 debug!("is_type_structurally_recursive: {}",
3811 ::util::ppaux::ty_to_string(cx, ty));
3814 ty_struct(did, _) | ty_enum(did, _) => {
3816 // Iterate through stack of previously seen types.
3817 let mut iter = seen.iter();
3819 // The first item in `seen` is the type we are actually curious about.
3820 // We want to return SelfRecursive if this type contains itself.
3821 // It is important that we DON'T take generic parameters into account
3822 // for this check, so that Bar<T> in this example counts as SelfRecursive:
3825 // struct Bar<T> { x: Bar<Foo> }
3828 Some(&seen_type) => {
3829 if same_struct_or_enum_def_id(seen_type, did) {
3830 debug!("SelfRecursive: {} contains {}",
3831 ::util::ppaux::ty_to_string(cx, seen_type),
3832 ::util::ppaux::ty_to_string(cx, ty));
3833 return SelfRecursive;
3839 // We also need to know whether the first item contains other types that
3840 // are structurally recursive. If we don't catch this case, we will recurse
3841 // infinitely for some inputs.
3843 // It is important that we DO take generic parameters into account here,
3844 // so that code like this is considered SelfRecursive, not ContainsRecursive:
3846 // struct Foo { Option<Option<Foo>> }
3848 for &seen_type in iter {
3849 if same_type(ty, seen_type) {
3850 debug!("ContainsRecursive: {} contains {}",
3851 ::util::ppaux::ty_to_string(cx, seen_type),
3852 ::util::ppaux::ty_to_string(cx, ty));
3853 return ContainsRecursive;
3858 // For structs and enums, track all previously seen types by pushing them
3859 // onto the 'seen' stack.
3861 let out = are_inner_types_recursive(cx, sp, seen, ty);
3866 // No need to push in other cases.
3867 are_inner_types_recursive(cx, sp, seen, ty)
3872 debug!("is_type_representable: {}",
3873 ::util::ppaux::ty_to_string(cx, ty));
3875 // To avoid a stack overflow when checking an enum variant or struct that
3876 // contains a different, structurally recursive type, maintain a stack
3877 // of seen types and check recursion for each of them (issues #3008, #3779).
3878 let mut seen: Vec<Ty> = Vec::new();
3879 let r = is_type_structurally_recursive(cx, sp, &mut seen, ty);
3880 debug!("is_type_representable: {} is {}",
3881 ::util::ppaux::ty_to_string(cx, ty), r);
3885 pub fn type_is_trait(ty: Ty) -> bool {
3886 type_trait_info(ty).is_some()
3889 pub fn type_trait_info<'tcx>(ty: Ty<'tcx>) -> Option<&'tcx TyTrait<'tcx>> {
3891 ty_uniq(ty) | ty_rptr(_, mt { ty, ..}) | ty_ptr(mt { ty, ..}) => match ty.sty {
3892 ty_trait(ref t) => Some(&**t),
3895 ty_trait(ref t) => Some(&**t),
3900 pub fn type_is_integral(ty: Ty) -> bool {
3902 ty_infer(IntVar(_)) | ty_int(_) | ty_uint(_) => true,
3907 pub fn type_is_fresh(ty: Ty) -> bool {
3909 ty_infer(FreshTy(_)) => true,
3910 ty_infer(FreshIntTy(_)) => true,
3915 pub fn type_is_uint(ty: Ty) -> bool {
3917 ty_infer(IntVar(_)) | ty_uint(ast::TyU) => true,
3922 pub fn type_is_char(ty: Ty) -> bool {
3929 pub fn type_is_bare_fn(ty: Ty) -> bool {
3931 ty_bare_fn(..) => true,
3936 pub fn type_is_bare_fn_item(ty: Ty) -> bool {
3938 ty_bare_fn(Some(_), _) => true,
3943 pub fn type_is_fp(ty: Ty) -> bool {
3945 ty_infer(FloatVar(_)) | ty_float(_) => true,
3950 pub fn type_is_numeric(ty: Ty) -> bool {
3951 return type_is_integral(ty) || type_is_fp(ty);
3954 pub fn type_is_signed(ty: Ty) -> bool {
3961 pub fn type_is_machine(ty: Ty) -> bool {
3963 ty_int(ast::TyI) | ty_uint(ast::TyU) => false,
3964 ty_int(..) | ty_uint(..) | ty_float(..) => true,
3969 // Whether a type is enum like, that is an enum type with only nullary
3971 pub fn type_is_c_like_enum(cx: &ctxt, ty: Ty) -> bool {
3973 ty_enum(did, _) => {
3974 let variants = enum_variants(cx, did);
3975 if variants.len() == 0 {
3978 variants.iter().all(|v| v.args.len() == 0)
3985 // Returns the type and mutability of *ty.
3987 // The parameter `explicit` indicates if this is an *explicit* dereference.
3988 // Some types---notably unsafe ptrs---can only be dereferenced explicitly.
3989 pub fn deref<'tcx>(ty: Ty<'tcx>, explicit: bool) -> Option<mt<'tcx>> {
3994 mutbl: ast::MutImmutable,
3997 ty_rptr(_, mt) => Some(mt),
3998 ty_ptr(mt) if explicit => Some(mt),
4003 pub fn close_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
4005 ty_open(ty) => mk_rptr(cx, cx.mk_region(ReStatic), mt {ty: ty, mutbl:ast::MutImmutable}),
4006 _ => cx.sess.bug(format!("Trying to close a non-open type {}",
4007 ty_to_string(cx, ty))[])
4011 pub fn type_content<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
4014 ty_rptr(_, mt) |ty_ptr(mt) => mt.ty,
4019 // Extract the unsized type in an open type (or just return ty if it is not open).
4020 pub fn unopen_type<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
4027 // Returns the type of ty[i]
4028 pub fn index<'tcx>(ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
4030 ty_vec(ty, _) => Some(ty),
4035 // Returns the type of elements contained within an 'array-like' type.
4036 // This is exactly the same as the above, except it supports strings,
4037 // which can't actually be indexed.
4038 pub fn array_element_ty<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
4040 ty_vec(ty, _) => Some(ty),
4041 ty_str => Some(tcx.types.u8),
4046 /// Returns the type of element at index `i` in tuple or tuple-like type `t`.
4047 /// For an enum `t`, `variant` is None only if `t` is a univariant enum.
4048 pub fn positional_element_ty<'tcx>(cx: &ctxt<'tcx>,
4051 variant: Option<ast::DefId>) -> Option<Ty<'tcx>> {
4053 match (&ty.sty, variant) {
4054 (&ty_tup(ref v), None) => v.get(i).map(|&t| t),
4057 (&ty_struct(def_id, substs), None) => lookup_struct_fields(cx, def_id)
4059 .map(|&t|lookup_item_type(cx, t.id).ty.subst(cx, substs)),
4061 (&ty_enum(def_id, substs), Some(variant_def_id)) => {
4062 let variant_info = enum_variant_with_id(cx, def_id, variant_def_id);
4063 variant_info.args.get(i).map(|t|t.subst(cx, substs))
4066 (&ty_enum(def_id, substs), None) => {
4067 assert!(enum_is_univariant(cx, def_id));
4068 let enum_variants = enum_variants(cx, def_id);
4069 let variant_info = &(*enum_variants)[0];
4070 variant_info.args.get(i).map(|t|t.subst(cx, substs))
4077 /// Returns the type of element at field `n` in struct or struct-like type `t`.
4078 /// For an enum `t`, `variant` must be some def id.
4079 pub fn named_element_ty<'tcx>(cx: &ctxt<'tcx>,
4082 variant: Option<ast::DefId>) -> Option<Ty<'tcx>> {
4084 match (&ty.sty, variant) {
4085 (&ty_struct(def_id, substs), None) => {
4086 let r = lookup_struct_fields(cx, def_id);
4087 r.iter().find(|f| f.name == n)
4088 .map(|&f| lookup_field_type(cx, def_id, f.id, substs))
4090 (&ty_enum(def_id, substs), Some(variant_def_id)) => {
4091 let variant_info = enum_variant_with_id(cx, def_id, variant_def_id);
4092 variant_info.arg_names.as_ref()
4093 .expect("must have struct enum variant if accessing a named fields")
4094 .iter().zip(variant_info.args.iter())
4095 .find(|&(ident, _)| ident.name == n)
4096 .map(|(_ident, arg_t)| arg_t.subst(cx, substs))
4102 pub fn node_id_to_trait_ref<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId)
4103 -> Rc<ty::TraitRef<'tcx>> {
4104 match cx.trait_refs.borrow().get(&id) {
4105 Some(ty) => ty.clone(),
4106 None => cx.sess.bug(
4107 format!("node_id_to_trait_ref: no trait ref for node `{}`",
4108 cx.map.node_to_string(id))[])
4112 pub fn try_node_id_to_type<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Option<Ty<'tcx>> {
4113 cx.node_types.borrow().get(&id).cloned()
4116 pub fn node_id_to_type<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Ty<'tcx> {
4117 match try_node_id_to_type(cx, id) {
4119 None => cx.sess.bug(
4120 format!("node_id_to_type: no type for node `{}`",
4121 cx.map.node_to_string(id))[])
4125 pub fn node_id_to_type_opt<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Option<Ty<'tcx>> {
4126 match cx.node_types.borrow().get(&id) {
4127 Some(&ty) => Some(ty),
4132 pub fn node_id_item_substs<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> ItemSubsts<'tcx> {
4133 match cx.item_substs.borrow().get(&id) {
4134 None => ItemSubsts::empty(),
4135 Some(ts) => ts.clone(),
4139 pub fn fn_is_variadic(fty: Ty) -> bool {
4141 ty_bare_fn(_, ref f) => f.sig.0.variadic,
4143 panic!("fn_is_variadic() called on non-fn type: {}", s)
4148 pub fn ty_fn_sig<'tcx>(fty: Ty<'tcx>) -> &'tcx PolyFnSig<'tcx> {
4150 ty_bare_fn(_, ref f) => &f.sig,
4152 panic!("ty_fn_sig() called on non-fn type: {}", s)
4157 /// Returns the ABI of the given function.
4158 pub fn ty_fn_abi(fty: Ty) -> abi::Abi {
4160 ty_bare_fn(_, ref f) => f.abi,
4161 _ => panic!("ty_fn_abi() called on non-fn type"),
4165 // Type accessors for substructures of types
4166 pub fn ty_fn_args<'tcx>(fty: Ty<'tcx>) -> &'tcx [Ty<'tcx>] {
4167 ty_fn_sig(fty).0.inputs.as_slice()
4170 pub fn ty_closure_store(fty: Ty) -> TraitStore {
4172 ty_unboxed_closure(..) => {
4173 // Close enough for the purposes of all the callers of this
4174 // function (which is soon to be deprecated anyhow).
4178 panic!("ty_closure_store() called on non-closure type: {}", s)
4183 pub fn ty_fn_ret<'tcx>(fty: Ty<'tcx>) -> FnOutput<'tcx> {
4185 ty_bare_fn(_, ref f) => f.sig.0.output,
4187 panic!("ty_fn_ret() called on non-fn type: {}", s)
4192 pub fn is_fn_ty(fty: Ty) -> bool {
4194 ty_bare_fn(..) => true,
4199 pub fn ty_region(tcx: &ctxt,
4203 ty_rptr(r, _) => *r,
4207 format!("ty_region() invoked on an inappropriate ty: {}",
4213 pub fn free_region_from_def(free_id: ast::NodeId, def: &RegionParameterDef)
4216 ty::ReFree(ty::FreeRegion { scope: region::CodeExtent::from_node_id(free_id),
4217 bound_region: ty::BrNamed(def.def_id,
4221 // Returns the type of a pattern as a monotype. Like @expr_ty, this function
4222 // doesn't provide type parameter substitutions.
4223 pub fn pat_ty<'tcx>(cx: &ctxt<'tcx>, pat: &ast::Pat) -> Ty<'tcx> {
4224 return node_id_to_type(cx, pat.id);
4228 // Returns the type of an expression as a monotype.
4230 // NB (1): This is the PRE-ADJUSTMENT TYPE for the expression. That is, in
4231 // some cases, we insert `AutoAdjustment` annotations such as auto-deref or
4232 // auto-ref. The type returned by this function does not consider such
4233 // adjustments. See `expr_ty_adjusted()` instead.
4235 // NB (2): This type doesn't provide type parameter substitutions; e.g. if you
4236 // ask for the type of "id" in "id(3)", it will return "fn(&int) -> int"
4237 // instead of "fn(ty) -> T with T = int".
4238 pub fn expr_ty<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Ty<'tcx> {
4239 return node_id_to_type(cx, expr.id);
4242 pub fn expr_ty_opt<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Option<Ty<'tcx>> {
4243 return node_id_to_type_opt(cx, expr.id);
4246 /// Returns the type of `expr`, considering any `AutoAdjustment`
4247 /// entry recorded for that expression.
4249 /// It would almost certainly be better to store the adjusted ty in with
4250 /// the `AutoAdjustment`, but I opted not to do this because it would
4251 /// require serializing and deserializing the type and, although that's not
4252 /// hard to do, I just hate that code so much I didn't want to touch it
4253 /// unless it was to fix it properly, which seemed a distraction from the
4254 /// task at hand! -nmatsakis
4255 pub fn expr_ty_adjusted<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Ty<'tcx> {
4256 adjust_ty(cx, expr.span, expr.id, expr_ty(cx, expr),
4257 cx.adjustments.borrow().get(&expr.id),
4258 |method_call| cx.method_map.borrow().get(&method_call).map(|method| method.ty))
4261 pub fn expr_span(cx: &ctxt, id: NodeId) -> Span {
4262 match cx.map.find(id) {
4263 Some(ast_map::NodeExpr(e)) => {
4267 cx.sess.bug(format!("Node id {} is not an expr: {}",
4272 cx.sess.bug(format!("Node id {} is not present \
4273 in the node map", id)[]);
4278 pub fn local_var_name_str(cx: &ctxt, id: NodeId) -> InternedString {
4279 match cx.map.find(id) {
4280 Some(ast_map::NodeLocal(pat)) => {
4282 ast::PatIdent(_, ref path1, _) => {
4283 token::get_ident(path1.node)
4287 format!("Variable id {} maps to {}, not local",
4294 cx.sess.bug(format!("Variable id {} maps to {}, not local",
4301 /// See `expr_ty_adjusted`
4302 pub fn adjust_ty<'tcx, F>(cx: &ctxt<'tcx>,
4304 expr_id: ast::NodeId,
4305 unadjusted_ty: Ty<'tcx>,
4306 adjustment: Option<&AutoAdjustment<'tcx>>,
4309 F: FnMut(MethodCall) -> Option<Ty<'tcx>>,
4311 if let ty_err = unadjusted_ty.sty {
4312 return unadjusted_ty;
4315 return match adjustment {
4316 Some(adjustment) => {
4318 AdjustAddEnv(_, store) => {
4319 match unadjusted_ty.sty {
4320 ty::ty_bare_fn(Some(_), ref b) => {
4321 let bounds = ty::ExistentialBounds {
4322 region_bound: ReStatic,
4323 builtin_bounds: all_builtin_bounds(),
4324 projection_bounds: vec!(),
4329 ty::ClosureTy {unsafety: b.unsafety,
4330 onceness: ast::Many,
4338 format!("add_env adjustment on non-fn-item: \
4345 AdjustReifyFnPointer(_) => {
4346 match unadjusted_ty.sty {
4347 ty::ty_bare_fn(Some(_), b) => {
4348 ty::mk_bare_fn(cx, None, b)
4352 format!("AdjustReifyFnPointer adjustment on non-fn-item: \
4359 AdjustDerefRef(ref adj) => {
4360 let mut adjusted_ty = unadjusted_ty;
4362 if !ty::type_is_error(adjusted_ty) {
4363 for i in range(0, adj.autoderefs) {
4364 let method_call = MethodCall::autoderef(expr_id, i);
4365 match method_type(method_call) {
4366 Some(method_ty) => {
4367 if let ty::FnConverging(result_type) = ty_fn_ret(method_ty) {
4368 adjusted_ty = result_type;
4373 match deref(adjusted_ty, true) {
4374 Some(mt) => { adjusted_ty = mt.ty; }
4378 format!("the {}th autoderef failed: \
4381 ty_to_string(cx, adjusted_ty))
4388 adjust_ty_for_autoref(cx, span, adjusted_ty, adj.autoref.as_ref())
4392 None => unadjusted_ty
4396 pub fn adjust_ty_for_autoref<'tcx>(cx: &ctxt<'tcx>,
4399 autoref: Option<&AutoRef<'tcx>>)
4405 Some(&AutoPtr(r, m, ref a)) => {
4406 let adjusted_ty = match a {
4407 &Some(box ref a) => adjust_ty_for_autoref(cx, span, ty, Some(a)),
4410 mk_rptr(cx, cx.mk_region(r), mt {
4416 Some(&AutoUnsafe(m, ref a)) => {
4417 let adjusted_ty = match a {
4418 &Some(box ref a) => adjust_ty_for_autoref(cx, span, ty, Some(a)),
4421 mk_ptr(cx, mt {ty: adjusted_ty, mutbl: m})
4424 Some(&AutoUnsize(ref k)) => unsize_ty(cx, ty, k, span),
4426 Some(&AutoUnsizeUniq(ref k)) => ty::mk_uniq(cx, unsize_ty(cx, ty, k, span)),
4430 // Take a sized type and a sizing adjustment and produce an unsized version of
4432 pub fn unsize_ty<'tcx>(cx: &ctxt<'tcx>,
4434 kind: &UnsizeKind<'tcx>,
4438 &UnsizeLength(len) => match ty.sty {
4439 ty_vec(ty, Some(n)) => {
4441 mk_vec(cx, ty, None)
4443 _ => cx.sess.span_bug(span,
4444 format!("UnsizeLength with bad sty: {}",
4445 ty_to_string(cx, ty))[])
4447 &UnsizeStruct(box ref k, tp_index) => match ty.sty {
4448 ty_struct(did, substs) => {
4449 let ty_substs = substs.types.get_slice(subst::TypeSpace);
4450 let new_ty = unsize_ty(cx, ty_substs[tp_index], k, span);
4451 let mut unsized_substs = substs.clone();
4452 unsized_substs.types.get_mut_slice(subst::TypeSpace)[tp_index] = new_ty;
4453 mk_struct(cx, did, cx.mk_substs(unsized_substs))
4455 _ => cx.sess.span_bug(span,
4456 format!("UnsizeStruct with bad sty: {}",
4457 ty_to_string(cx, ty))[])
4459 &UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
4460 mk_trait(cx, principal.clone(), bounds.clone())
4465 pub fn resolve_expr(tcx: &ctxt, expr: &ast::Expr) -> def::Def {
4466 match tcx.def_map.borrow().get(&expr.id) {
4469 tcx.sess.span_bug(expr.span, format!(
4470 "no def-map entry for expr {}", expr.id)[]);
4475 pub fn expr_is_lval(tcx: &ctxt, e: &ast::Expr) -> bool {
4476 match expr_kind(tcx, e) {
4478 RvalueDpsExpr | RvalueDatumExpr | RvalueStmtExpr => false
4482 /// We categorize expressions into three kinds. The distinction between
4483 /// lvalue/rvalue is fundamental to the language. The distinction between the
4484 /// two kinds of rvalues is an artifact of trans which reflects how we will
4485 /// generate code for that kind of expression. See trans/expr.rs for more
4495 pub fn expr_kind(tcx: &ctxt, expr: &ast::Expr) -> ExprKind {
4496 if tcx.method_map.borrow().contains_key(&MethodCall::expr(expr.id)) {
4497 // Overloaded operations are generally calls, and hence they are
4498 // generated via DPS, but there are a few exceptions:
4499 return match expr.node {
4500 // `a += b` has a unit result.
4501 ast::ExprAssignOp(..) => RvalueStmtExpr,
4503 // the deref method invoked for `*a` always yields an `&T`
4504 ast::ExprUnary(ast::UnDeref, _) => LvalueExpr,
4506 // the index method invoked for `a[i]` always yields an `&T`
4507 ast::ExprIndex(..) => LvalueExpr,
4509 // `for` loops are statements
4510 ast::ExprForLoop(..) => RvalueStmtExpr,
4512 // in the general case, result could be any type, use DPS
4518 ast::ExprPath(..) => {
4519 match resolve_expr(tcx, expr) {
4520 def::DefVariant(tid, vid, _) => {
4521 let variant_info = enum_variant_with_id(tcx, tid, vid);
4522 if variant_info.args.len() > 0u {
4531 def::DefStruct(_) => {
4532 match tcx.node_types.borrow().get(&expr.id) {
4533 Some(ty) => match ty.sty {
4534 ty_bare_fn(..) => RvalueDatumExpr,
4537 // See ExprCast below for why types might be missing.
4538 None => RvalueDatumExpr
4542 // Special case: A unit like struct's constructor must be called without () at the
4543 // end (like `UnitStruct`) which means this is an ExprPath to a DefFn. But in case
4544 // of unit structs this is should not be interpreted as function pointer but as
4545 // call to the constructor.
4546 def::DefFn(_, true) => RvalueDpsExpr,
4548 // Fn pointers are just scalar values.
4549 def::DefFn(..) | def::DefStaticMethod(..) | def::DefMethod(..) => RvalueDatumExpr,
4551 // Note: there is actually a good case to be made that
4552 // DefArg's, particularly those of immediate type, ought to
4553 // considered rvalues.
4554 def::DefStatic(..) |
4556 def::DefLocal(..) => LvalueExpr,
4558 def::DefConst(..) => RvalueDatumExpr,
4563 format!("uncategorized def for expr {}: {}",
4570 ast::ExprUnary(ast::UnDeref, _) |
4571 ast::ExprField(..) |
4572 ast::ExprTupField(..) |
4573 ast::ExprIndex(..) => {
4578 ast::ExprMethodCall(..) |
4579 ast::ExprStruct(..) |
4580 ast::ExprRange(..) |
4583 ast::ExprMatch(..) |
4584 ast::ExprClosure(..) |
4585 ast::ExprBlock(..) |
4586 ast::ExprRepeat(..) |
4587 ast::ExprVec(..) => {
4591 ast::ExprIfLet(..) => {
4592 tcx.sess.span_bug(expr.span, "non-desugared ExprIfLet");
4594 ast::ExprWhileLet(..) => {
4595 tcx.sess.span_bug(expr.span, "non-desugared ExprWhileLet");
4598 ast::ExprLit(ref lit) if lit_is_str(&**lit) => {
4602 ast::ExprCast(..) => {
4603 match tcx.node_types.borrow().get(&expr.id) {
4605 if type_is_trait(ty) {
4612 // Technically, it should not happen that the expr is not
4613 // present within the table. However, it DOES happen
4614 // during type check, because the final types from the
4615 // expressions are not yet recorded in the tcx. At that
4616 // time, though, we are only interested in knowing lvalue
4617 // vs rvalue. It would be better to base this decision on
4618 // the AST type in cast node---but (at the time of this
4619 // writing) it's not easy to distinguish casts to traits
4620 // from other casts based on the AST. This should be
4621 // easier in the future, when casts to traits
4622 // would like @Foo, Box<Foo>, or &Foo.
4628 ast::ExprBreak(..) |
4629 ast::ExprAgain(..) |
4631 ast::ExprWhile(..) |
4633 ast::ExprAssign(..) |
4634 ast::ExprInlineAsm(..) |
4635 ast::ExprAssignOp(..) |
4636 ast::ExprForLoop(..) => {
4640 ast::ExprLit(_) | // Note: LitStr is carved out above
4641 ast::ExprUnary(..) |
4642 ast::ExprBox(None, _) |
4643 ast::ExprAddrOf(..) |
4644 ast::ExprBinary(..) => {
4648 ast::ExprBox(Some(ref place), _) => {
4649 // Special case `Box<T>` for now:
4650 let definition = match tcx.def_map.borrow().get(&place.id) {
4652 None => panic!("no def for place"),
4654 let def_id = definition.def_id();
4655 if tcx.lang_items.exchange_heap() == Some(def_id) {
4662 ast::ExprParen(ref e) => expr_kind(tcx, &**e),
4664 ast::ExprMac(..) => {
4667 "macro expression remains after expansion");
4672 pub fn stmt_node_id(s: &ast::Stmt) -> ast::NodeId {
4674 ast::StmtDecl(_, id) | StmtExpr(_, id) | StmtSemi(_, id) => {
4677 ast::StmtMac(..) => panic!("unexpanded macro in trans")
4681 pub fn field_idx_strict(tcx: &ctxt, name: ast::Name, fields: &[field])
4684 for f in fields.iter() { if f.name == name { return i; } i += 1u; }
4685 tcx.sess.bug(format!(
4686 "no field named `{}` found in the list of fields `{}`",
4687 token::get_name(name),
4689 .map(|f| token::get_name(f.name).get().to_string())
4690 .collect::<Vec<String>>())[]);
4693 pub fn impl_or_trait_item_idx(id: ast::Name, trait_items: &[ImplOrTraitItem])
4695 trait_items.iter().position(|m| m.name() == id)
4698 pub fn ty_sort_string<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> String {
4700 ty_bool | ty_char | ty_int(_) |
4701 ty_uint(_) | ty_float(_) | ty_str => {
4702 ::util::ppaux::ty_to_string(cx, ty)
4704 ty_tup(ref tys) if tys.is_empty() => ::util::ppaux::ty_to_string(cx, ty),
4706 ty_enum(id, _) => format!("enum {}", item_path_str(cx, id)),
4707 ty_uniq(_) => "box".to_string(),
4708 ty_vec(_, Some(n)) => format!("array of {} elements", n),
4709 ty_vec(_, None) => "slice".to_string(),
4710 ty_ptr(_) => "*-ptr".to_string(),
4711 ty_rptr(_, _) => "&-ptr".to_string(),
4712 ty_bare_fn(Some(_), _) => format!("fn item"),
4713 ty_bare_fn(None, _) => "fn pointer".to_string(),
4714 ty_trait(ref inner) => {
4715 format!("trait {}", item_path_str(cx, inner.principal_def_id()))
4717 ty_struct(id, _) => {
4718 format!("struct {}", item_path_str(cx, id))
4720 ty_unboxed_closure(..) => "closure".to_string(),
4721 ty_tup(_) => "tuple".to_string(),
4722 ty_infer(TyVar(_)) => "inferred type".to_string(),
4723 ty_infer(IntVar(_)) => "integral variable".to_string(),
4724 ty_infer(FloatVar(_)) => "floating-point variable".to_string(),
4725 ty_infer(FreshTy(_)) => "skolemized type".to_string(),
4726 ty_infer(FreshIntTy(_)) => "skolemized integral type".to_string(),
4727 ty_projection(_) => "associated type".to_string(),
4728 ty_param(ref p) => {
4729 if p.space == subst::SelfSpace {
4732 "type parameter".to_string()
4735 ty_err => "type error".to_string(),
4736 ty_open(_) => "opened DST".to_string(),
4740 impl<'tcx> Repr<'tcx> for ty::type_err<'tcx> {
4741 fn repr(&self, tcx: &ty::ctxt<'tcx>) -> String {
4742 ty::type_err_to_str(tcx, self)
4746 /// Explains the source of a type err in a short, human readable way. This is meant to be placed
4747 /// in parentheses after some larger message. You should also invoke `note_and_explain_type_err()`
4748 /// afterwards to present additional details, particularly when it comes to lifetime-related
4750 pub fn type_err_to_str<'tcx>(cx: &ctxt<'tcx>, err: &type_err<'tcx>) -> String {
4751 fn tstore_to_closure(s: &TraitStore) -> String {
4753 &UniqTraitStore => "proc".to_string(),
4754 &RegionTraitStore(..) => "closure".to_string()
4759 terr_cyclic_ty => "cyclic type of infinite size".to_string(),
4760 terr_mismatch => "types differ".to_string(),
4761 terr_unsafety_mismatch(values) => {
4762 format!("expected {} fn, found {} fn",
4763 values.expected.to_string(),
4764 values.found.to_string())
4766 terr_abi_mismatch(values) => {
4767 format!("expected {} fn, found {} fn",
4768 values.expected.to_string(),
4769 values.found.to_string())
4771 terr_onceness_mismatch(values) => {
4772 format!("expected {} fn, found {} fn",
4773 values.expected.to_string(),
4774 values.found.to_string())
4776 terr_sigil_mismatch(values) => {
4777 format!("expected {}, found {}",
4778 tstore_to_closure(&values.expected),
4779 tstore_to_closure(&values.found))
4781 terr_mutability => "values differ in mutability".to_string(),
4782 terr_box_mutability => {
4783 "boxed values differ in mutability".to_string()
4785 terr_vec_mutability => "vectors differ in mutability".to_string(),
4786 terr_ptr_mutability => "pointers differ in mutability".to_string(),
4787 terr_ref_mutability => "references differ in mutability".to_string(),
4788 terr_ty_param_size(values) => {
4789 format!("expected a type with {} type params, \
4790 found one with {} type params",
4794 terr_fixed_array_size(values) => {
4795 format!("expected an array with a fixed size of {} elements, \
4796 found one with {} elements",
4800 terr_tuple_size(values) => {
4801 format!("expected a tuple with {} elements, \
4802 found one with {} elements",
4807 "incorrect number of function parameters".to_string()
4809 terr_regions_does_not_outlive(..) => {
4810 "lifetime mismatch".to_string()
4812 terr_regions_not_same(..) => {
4813 "lifetimes are not the same".to_string()
4815 terr_regions_no_overlap(..) => {
4816 "lifetimes do not intersect".to_string()
4818 terr_regions_insufficiently_polymorphic(br, _) => {
4819 format!("expected bound lifetime parameter {}, \
4820 found concrete lifetime",
4821 bound_region_ptr_to_string(cx, br))
4823 terr_regions_overly_polymorphic(br, _) => {
4824 format!("expected concrete lifetime, \
4825 found bound lifetime parameter {}",
4826 bound_region_ptr_to_string(cx, br))
4828 terr_trait_stores_differ(_, ref values) => {
4829 format!("trait storage differs: expected `{}`, found `{}`",
4830 trait_store_to_string(cx, (*values).expected),
4831 trait_store_to_string(cx, (*values).found))
4833 terr_sorts(values) => {
4834 // A naive approach to making sure that we're not reporting silly errors such as:
4835 // (expected closure, found closure).
4836 let expected_str = ty_sort_string(cx, values.expected);
4837 let found_str = ty_sort_string(cx, values.found);
4838 if expected_str == found_str {
4839 format!("expected {}, found a different {}", expected_str, found_str)
4841 format!("expected {}, found {}", expected_str, found_str)
4844 terr_traits(values) => {
4845 format!("expected trait `{}`, found trait `{}`",
4846 item_path_str(cx, values.expected),
4847 item_path_str(cx, values.found))
4849 terr_builtin_bounds(values) => {
4850 if values.expected.is_empty() {
4851 format!("expected no bounds, found `{}`",
4852 values.found.user_string(cx))
4853 } else if values.found.is_empty() {
4854 format!("expected bounds `{}`, found no bounds",
4855 values.expected.user_string(cx))
4857 format!("expected bounds `{}`, found bounds `{}`",
4858 values.expected.user_string(cx),
4859 values.found.user_string(cx))
4862 terr_integer_as_char => {
4863 "expected an integral type, found `char`".to_string()
4865 terr_int_mismatch(ref values) => {
4866 format!("expected `{}`, found `{}`",
4867 values.expected.to_string(),
4868 values.found.to_string())
4870 terr_float_mismatch(ref values) => {
4871 format!("expected `{}`, found `{}`",
4872 values.expected.to_string(),
4873 values.found.to_string())
4875 terr_variadic_mismatch(ref values) => {
4876 format!("expected {} fn, found {} function",
4877 if values.expected { "variadic" } else { "non-variadic" },
4878 if values.found { "variadic" } else { "non-variadic" })
4880 terr_convergence_mismatch(ref values) => {
4881 format!("expected {} fn, found {} function",
4882 if values.expected { "converging" } else { "diverging" },
4883 if values.found { "converging" } else { "diverging" })
4885 terr_projection_name_mismatched(ref values) => {
4886 format!("expected {}, found {}",
4887 token::get_name(values.expected),
4888 token::get_name(values.found))
4890 terr_projection_bounds_length(ref values) => {
4891 format!("expected {} associated type bindings, found {}",
4898 pub fn note_and_explain_type_err(cx: &ctxt, err: &type_err) {
4900 terr_regions_does_not_outlive(subregion, superregion) => {
4901 note_and_explain_region(cx, "", subregion, "...");
4902 note_and_explain_region(cx, "...does not necessarily outlive ",
4905 terr_regions_not_same(region1, region2) => {
4906 note_and_explain_region(cx, "", region1, "...");
4907 note_and_explain_region(cx, "...is not the same lifetime as ",
4910 terr_regions_no_overlap(region1, region2) => {
4911 note_and_explain_region(cx, "", region1, "...");
4912 note_and_explain_region(cx, "...does not overlap ",
4915 terr_regions_insufficiently_polymorphic(_, conc_region) => {
4916 note_and_explain_region(cx,
4917 "concrete lifetime that was found is ",
4920 terr_regions_overly_polymorphic(_, ty::ReInfer(ty::ReVar(_))) => {
4921 // don't bother to print out the message below for
4922 // inference variables, it's not very illuminating.
4924 terr_regions_overly_polymorphic(_, conc_region) => {
4925 note_and_explain_region(cx,
4926 "expected concrete lifetime is ",
4933 pub fn provided_source(cx: &ctxt, id: ast::DefId) -> Option<ast::DefId> {
4934 cx.provided_method_sources.borrow().get(&id).map(|x| *x)
4937 pub fn provided_trait_methods<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
4938 -> Vec<Rc<Method<'tcx>>> {
4940 match cx.map.find(id.node) {
4941 Some(ast_map::NodeItem(item)) => {
4943 ItemTrait(_, _, _, ref ms) => {
4945 ast_util::split_trait_methods(ms[]);
4948 match impl_or_trait_item(
4950 ast_util::local_def(m.id)) {
4951 MethodTraitItem(m) => m,
4952 TypeTraitItem(_) => {
4953 cx.sess.bug("provided_trait_methods(): \
4954 split_trait_methods() put \
4955 associated types in the \
4956 provided method bucket?!")
4962 cx.sess.bug(format!("provided_trait_methods: `{}` is \
4969 cx.sess.bug(format!("provided_trait_methods: `{}` is not a \
4975 csearch::get_provided_trait_methods(cx, id)
4979 /// Helper for looking things up in the various maps that are populated during
4980 /// typeck::collect (e.g., `cx.impl_or_trait_items`, `cx.tcache`, etc). All of
4981 /// these share the pattern that if the id is local, it should have been loaded
4982 /// into the map by the `typeck::collect` phase. If the def-id is external,
4983 /// then we have to go consult the crate loading code (and cache the result for
4985 fn lookup_locally_or_in_crate_store<V, F>(descr: &str,
4987 map: &mut DefIdMap<V>,
4988 load_external: F) -> V where
4992 match map.get(&def_id).cloned() {
4993 Some(v) => { return v; }
4997 if def_id.krate == ast::LOCAL_CRATE {
4998 panic!("No def'n found for {} in tcx.{}", def_id, descr);
5000 let v = load_external();
5001 map.insert(def_id, v.clone());
5005 pub fn trait_item<'tcx>(cx: &ctxt<'tcx>, trait_did: ast::DefId, idx: uint)
5006 -> ImplOrTraitItem<'tcx> {
5007 let method_def_id = (*ty::trait_item_def_ids(cx, trait_did))[idx].def_id();
5008 impl_or_trait_item(cx, method_def_id)
5011 pub fn trait_items<'tcx>(cx: &ctxt<'tcx>, trait_did: ast::DefId)
5012 -> Rc<Vec<ImplOrTraitItem<'tcx>>> {
5013 let mut trait_items = cx.trait_items_cache.borrow_mut();
5014 match trait_items.get(&trait_did).cloned() {
5015 Some(trait_items) => trait_items,
5017 let def_ids = ty::trait_item_def_ids(cx, trait_did);
5018 let items: Rc<Vec<ImplOrTraitItem>> =
5019 Rc::new(def_ids.iter()
5020 .map(|d| impl_or_trait_item(cx, d.def_id()))
5022 trait_items.insert(trait_did, items.clone());
5028 pub fn impl_or_trait_item<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5029 -> ImplOrTraitItem<'tcx> {
5030 lookup_locally_or_in_crate_store("impl_or_trait_items",
5032 &mut *cx.impl_or_trait_items
5035 csearch::get_impl_or_trait_item(cx, id)
5039 /// Returns true if the given ID refers to an associated type and false if it
5040 /// refers to anything else.
5041 pub fn is_associated_type(cx: &ctxt, id: ast::DefId) -> bool {
5042 memoized(&cx.associated_types, id, |id: ast::DefId| {
5043 if id.krate == ast::LOCAL_CRATE {
5044 match cx.impl_or_trait_items.borrow().get(&id) {
5047 TypeTraitItem(_) => true,
5048 MethodTraitItem(_) => false,
5054 csearch::is_associated_type(&cx.sess.cstore, id)
5059 /// Returns the parameter index that the given associated type corresponds to.
5060 pub fn associated_type_parameter_index(cx: &ctxt,
5061 trait_def: &TraitDef,
5062 associated_type_id: ast::DefId)
5064 for type_parameter_def in trait_def.generics.types.iter() {
5065 if type_parameter_def.def_id == associated_type_id {
5066 return type_parameter_def.index as uint
5069 cx.sess.bug("couldn't find associated type parameter index")
5072 #[derive(Copy, PartialEq, Eq)]
5073 pub struct AssociatedTypeInfo {
5074 pub def_id: ast::DefId,
5076 pub name: ast::Name,
5079 impl PartialOrd for AssociatedTypeInfo {
5080 fn partial_cmp(&self, other: &AssociatedTypeInfo) -> Option<Ordering> {
5081 Some(self.index.cmp(&other.index))
5085 impl Ord for AssociatedTypeInfo {
5086 fn cmp(&self, other: &AssociatedTypeInfo) -> Ordering {
5087 self.index.cmp(&other.index)
5091 pub fn trait_item_def_ids(cx: &ctxt, id: ast::DefId)
5092 -> Rc<Vec<ImplOrTraitItemId>> {
5093 lookup_locally_or_in_crate_store("trait_item_def_ids",
5095 &mut *cx.trait_item_def_ids.borrow_mut(),
5097 Rc::new(csearch::get_trait_item_def_ids(&cx.sess.cstore, id))
5101 pub fn impl_trait_ref<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5102 -> Option<Rc<TraitRef<'tcx>>> {
5103 memoized(&cx.impl_trait_cache, id, |id: ast::DefId| {
5104 if id.krate == ast::LOCAL_CRATE {
5105 debug!("(impl_trait_ref) searching for trait impl {}", id);
5106 match cx.map.find(id.node) {
5107 Some(ast_map::NodeItem(item)) => {
5109 ast::ItemImpl(_, _, _, ref opt_trait, _, _) => {
5112 let trait_ref = ty::node_id_to_trait_ref(cx, t.ref_id);
5124 csearch::get_impl_trait(cx, id)
5129 pub fn trait_ref_to_def_id(tcx: &ctxt, tr: &ast::TraitRef) -> ast::DefId {
5130 let def = *tcx.def_map.borrow()
5132 .expect("no def-map entry for trait");
5136 pub fn try_add_builtin_trait(
5138 trait_def_id: ast::DefId,
5139 builtin_bounds: &mut EnumSet<BuiltinBound>)
5142 //! Checks whether `trait_ref` refers to one of the builtin
5143 //! traits, like `Send`, and adds the corresponding
5144 //! bound to the set `builtin_bounds` if so. Returns true if `trait_ref`
5145 //! is a builtin trait.
5147 match tcx.lang_items.to_builtin_kind(trait_def_id) {
5148 Some(bound) => { builtin_bounds.insert(bound); true }
5153 pub fn ty_to_def_id(ty: Ty) -> Option<ast::DefId> {
5156 Some(tt.principal_def_id()),
5159 ty_unboxed_closure(id, _, _) =>
5168 pub struct VariantInfo<'tcx> {
5169 pub args: Vec<Ty<'tcx>>,
5170 pub arg_names: Option<Vec<ast::Ident>>,
5171 pub ctor_ty: Option<Ty<'tcx>>,
5172 pub name: ast::Name,
5178 impl<'tcx> VariantInfo<'tcx> {
5180 /// Creates a new VariantInfo from the corresponding ast representation.
5182 /// Does not do any caching of the value in the type context.
5183 pub fn from_ast_variant(cx: &ctxt<'tcx>,
5184 ast_variant: &ast::Variant,
5185 discriminant: Disr) -> VariantInfo<'tcx> {
5186 let ctor_ty = node_id_to_type(cx, ast_variant.node.id);
5188 match ast_variant.node.kind {
5189 ast::TupleVariantKind(ref args) => {
5190 let arg_tys = if args.len() > 0 {
5191 ty_fn_args(ctor_ty).iter().map(|a| *a).collect()
5196 return VariantInfo {
5199 ctor_ty: Some(ctor_ty),
5200 name: ast_variant.node.name.name,
5201 id: ast_util::local_def(ast_variant.node.id),
5202 disr_val: discriminant,
5203 vis: ast_variant.node.vis
5206 ast::StructVariantKind(ref struct_def) => {
5208 let fields: &[StructField] = struct_def.fields[];
5210 assert!(fields.len() > 0);
5212 let arg_tys = struct_def.fields.iter()
5213 .map(|field| node_id_to_type(cx, field.node.id)).collect();
5214 let arg_names = fields.iter().map(|field| {
5215 match field.node.kind {
5216 NamedField(ident, _) => ident,
5217 UnnamedField(..) => cx.sess.bug(
5218 "enum_variants: all fields in struct must have a name")
5222 return VariantInfo {
5224 arg_names: Some(arg_names),
5226 name: ast_variant.node.name.name,
5227 id: ast_util::local_def(ast_variant.node.id),
5228 disr_val: discriminant,
5229 vis: ast_variant.node.vis
5236 pub fn substd_enum_variants<'tcx>(cx: &ctxt<'tcx>,
5238 substs: &Substs<'tcx>)
5239 -> Vec<Rc<VariantInfo<'tcx>>> {
5240 enum_variants(cx, id).iter().map(|variant_info| {
5241 let substd_args = variant_info.args.iter()
5242 .map(|aty| aty.subst(cx, substs)).collect::<Vec<_>>();
5244 let substd_ctor_ty = variant_info.ctor_ty.subst(cx, substs);
5246 Rc::new(VariantInfo {
5248 ctor_ty: substd_ctor_ty,
5249 ..(**variant_info).clone()
5254 pub fn item_path_str(cx: &ctxt, id: ast::DefId) -> String {
5255 with_path(cx, id, |path| ast_map::path_to_string(path)).to_string()
5261 TraitDtor(DefId, bool)
5265 pub fn is_present(&self) -> bool {
5267 TraitDtor(..) => true,
5272 pub fn has_drop_flag(&self) -> bool {
5275 &TraitDtor(_, flag) => flag
5280 /* If struct_id names a struct with a dtor, return Some(the dtor's id).
5281 Otherwise return none. */
5282 pub fn ty_dtor(cx: &ctxt, struct_id: DefId) -> DtorKind {
5283 match cx.destructor_for_type.borrow().get(&struct_id) {
5284 Some(&method_def_id) => {
5285 let flag = !has_attr(cx, struct_id, "unsafe_no_drop_flag");
5287 TraitDtor(method_def_id, flag)
5293 pub fn has_dtor(cx: &ctxt, struct_id: DefId) -> bool {
5294 cx.destructor_for_type.borrow().contains_key(&struct_id)
5297 pub fn with_path<T, F>(cx: &ctxt, id: ast::DefId, f: F) -> T where
5298 F: FnOnce(ast_map::PathElems) -> T,
5300 if id.krate == ast::LOCAL_CRATE {
5301 cx.map.with_path(id.node, f)
5303 f(ast_map::Values(csearch::get_item_path(cx, id).iter()).chain(None))
5307 pub fn enum_is_univariant(cx: &ctxt, id: ast::DefId) -> bool {
5308 enum_variants(cx, id).len() == 1
5311 pub fn type_is_empty(cx: &ctxt, ty: Ty) -> bool {
5313 ty_enum(did, _) => (*enum_variants(cx, did)).is_empty(),
5318 pub fn enum_variants<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5319 -> Rc<Vec<Rc<VariantInfo<'tcx>>>> {
5320 memoized(&cx.enum_var_cache, id, |id: ast::DefId| {
5321 if ast::LOCAL_CRATE != id.krate {
5322 Rc::new(csearch::get_enum_variants(cx, id))
5325 Although both this code and check_enum_variants in typeck/check
5326 call eval_const_expr, it should never get called twice for the same
5327 expr, since check_enum_variants also updates the enum_var_cache
5329 match cx.map.get(id.node) {
5330 ast_map::NodeItem(ref item) => {
5332 ast::ItemEnum(ref enum_definition, _) => {
5333 let mut last_discriminant: Option<Disr> = None;
5334 Rc::new(enum_definition.variants.iter().map(|variant| {
5336 let mut discriminant = match last_discriminant {
5337 Some(val) => val + 1,
5338 None => INITIAL_DISCRIMINANT_VALUE
5341 match variant.node.disr_expr {
5343 match const_eval::eval_const_expr_partial(cx, &**e) {
5344 Ok(const_eval::const_int(val)) => {
5345 discriminant = val as Disr
5347 Ok(const_eval::const_uint(val)) => {
5348 discriminant = val as Disr
5353 "expected signed integer constant");
5358 format!("expected constant: {}",
5365 last_discriminant = Some(discriminant);
5366 Rc::new(VariantInfo::from_ast_variant(cx, &**variant,
5371 cx.sess.bug("enum_variants: id not bound to an enum")
5375 _ => cx.sess.bug("enum_variants: id not bound to an enum")
5381 // Returns information about the enum variant with the given ID:
5382 pub fn enum_variant_with_id<'tcx>(cx: &ctxt<'tcx>,
5383 enum_id: ast::DefId,
5384 variant_id: ast::DefId)
5385 -> Rc<VariantInfo<'tcx>> {
5386 enum_variants(cx, enum_id).iter()
5387 .find(|variant| variant.id == variant_id)
5388 .expect("enum_variant_with_id(): no variant exists with that ID")
5393 // If the given item is in an external crate, looks up its type and adds it to
5394 // the type cache. Returns the type parameters and type.
5395 pub fn lookup_item_type<'tcx>(cx: &ctxt<'tcx>,
5397 -> TypeScheme<'tcx> {
5398 lookup_locally_or_in_crate_store(
5399 "tcache", did, &mut *cx.tcache.borrow_mut(),
5400 || csearch::get_type(cx, did))
5403 /// Given the did of a trait, returns its canonical trait ref.
5404 pub fn lookup_trait_def<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId)
5405 -> Rc<ty::TraitDef<'tcx>> {
5406 memoized(&cx.trait_defs, did, |did: DefId| {
5407 assert!(did.krate != ast::LOCAL_CRATE);
5408 Rc::new(csearch::get_trait_def(cx, did))
5412 /// Given a reference to a trait, returns the "superbounds" declared
5413 /// on the trait, with appropriate substitutions applied. Basically,
5414 /// this applies a filter to the where clauses on the trait, returning
5415 /// those that have the form:
5417 /// Self : SuperTrait<...>
5419 pub fn predicates_for_trait_ref<'tcx>(tcx: &ctxt<'tcx>,
5420 trait_ref: &PolyTraitRef<'tcx>)
5421 -> Vec<ty::Predicate<'tcx>>
5423 let trait_def = lookup_trait_def(tcx, trait_ref.def_id());
5425 debug!("bounds_for_trait_ref(trait_def={}, trait_ref={})",
5426 trait_def.repr(tcx), trait_ref.repr(tcx));
5428 // The interaction between HRTB and supertraits is not entirely
5429 // obvious. Let me walk you (and myself) through an example.
5431 // Let's start with an easy case. Consider two traits:
5433 // trait Foo<'a> : Bar<'a,'a> { }
5434 // trait Bar<'b,'c> { }
5436 // Now, if we have a trait reference `for<'x> T : Foo<'x>`, then
5437 // we can deduce that `for<'x> T : Bar<'x,'x>`. Basically, if we
5438 // knew that `Foo<'x>` (for any 'x) then we also know that
5439 // `Bar<'x,'x>` (for any 'x). This more-or-less falls out from
5440 // normal substitution.
5442 // In terms of why this is sound, the idea is that whenever there
5443 // is an impl of `T:Foo<'a>`, it must show that `T:Bar<'a,'a>`
5444 // holds. So if there is an impl of `T:Foo<'a>` that applies to
5445 // all `'a`, then we must know that `T:Bar<'a,'a>` holds for all
5448 // Another example to be careful of is this:
5450 // trait Foo1<'a> : for<'b> Bar1<'a,'b> { }
5451 // trait Bar1<'b,'c> { }
5453 // Here, if we have `for<'x> T : Foo1<'x>`, then what do we know?
5454 // The answer is that we know `for<'x,'b> T : Bar1<'x,'b>`. The
5455 // reason is similar to the previous example: any impl of
5456 // `T:Foo1<'x>` must show that `for<'b> T : Bar1<'x, 'b>`. So
5457 // basically we would want to collapse the bound lifetimes from
5458 // the input (`trait_ref`) and the supertraits.
5460 // To achieve this in practice is fairly straightforward. Let's
5461 // consider the more complicated scenario:
5463 // - We start out with `for<'x> T : Foo1<'x>`. In this case, `'x`
5464 // has a De Bruijn index of 1. We want to produce `for<'x,'b> T : Bar1<'x,'b>`,
5465 // where both `'x` and `'b` would have a DB index of 1.
5466 // The substitution from the input trait-ref is therefore going to be
5467 // `'a => 'x` (where `'x` has a DB index of 1).
5468 // - The super-trait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an
5469 // early-bound parameter and `'b' is a late-bound parameter with a
5471 // - If we replace `'a` with `'x` from the input, it too will have
5472 // a DB index of 1, and thus we'll have `for<'x,'b> Bar1<'x,'b>`
5473 // just as we wanted.
5475 // There is only one catch. If we just apply the substitution `'a
5476 // => 'x` to `for<'b> Bar1<'a,'b>`, the substitution code will
5477 // adjust the DB index because we substituting into a binder (it
5478 // tries to be so smart...) resulting in `for<'x> for<'b>
5479 // Bar1<'x,'b>` (we have no syntax for this, so use your
5480 // imagination). Basically the 'x will have DB index of 2 and 'b
5481 // will have DB index of 1. Not quite what we want. So we apply
5482 // the substitution to the *contents* of the trait reference,
5483 // rather than the trait reference itself (put another way, the
5484 // substitution code expects equal binding levels in the values
5485 // from the substitution and the value being substituted into, and
5486 // this trick achieves that).
5488 // Carefully avoid the binder introduced by each trait-ref by
5489 // substituting over the substs, not the trait-refs themselves,
5490 // thus achieving the "collapse" described in the big comment
5492 let trait_bounds: Vec<_> =
5493 trait_def.bounds.trait_bounds
5495 .map(|poly_trait_ref| ty::Binder(poly_trait_ref.0.subst(tcx, trait_ref.substs())))
5498 let projection_bounds: Vec<_> =
5499 trait_def.bounds.projection_bounds
5501 .map(|poly_proj| ty::Binder(poly_proj.0.subst(tcx, trait_ref.substs())))
5504 debug!("bounds_for_trait_ref: trait_bounds={} projection_bounds={}",
5505 trait_bounds.repr(tcx),
5506 projection_bounds.repr(tcx));
5508 // The region bounds and builtin bounds do not currently introduce
5509 // binders so we can just substitute in a straightforward way here.
5511 trait_def.bounds.region_bounds.subst(tcx, trait_ref.substs());
5512 let builtin_bounds =
5513 trait_def.bounds.builtin_bounds.subst(tcx, trait_ref.substs());
5515 let bounds = ty::ParamBounds {
5516 trait_bounds: trait_bounds,
5517 region_bounds: region_bounds,
5518 builtin_bounds: builtin_bounds,
5519 projection_bounds: projection_bounds,
5522 predicates(tcx, trait_ref.self_ty(), &bounds)
5525 pub fn predicates<'tcx>(
5528 bounds: &ParamBounds<'tcx>)
5529 -> Vec<Predicate<'tcx>>
5531 let mut vec = Vec::new();
5533 for builtin_bound in bounds.builtin_bounds.iter() {
5534 match traits::trait_ref_for_builtin_bound(tcx, builtin_bound, param_ty) {
5535 Ok(trait_ref) => { vec.push(trait_ref.as_predicate()); }
5536 Err(ErrorReported) => { }
5540 for ®ion_bound in bounds.region_bounds.iter() {
5541 // account for the binder being introduced below; no need to shift `param_ty`
5542 // because, at present at least, it can only refer to early-bound regions
5543 let region_bound = ty_fold::shift_region(region_bound, 1);
5544 vec.push(ty::Binder(ty::OutlivesPredicate(param_ty, region_bound)).as_predicate());
5547 for bound_trait_ref in bounds.trait_bounds.iter() {
5548 vec.push(bound_trait_ref.as_predicate());
5551 for projection in bounds.projection_bounds.iter() {
5552 vec.push(projection.as_predicate());
5558 /// Iterate over attributes of a definition.
5559 // (This should really be an iterator, but that would require csearch and
5560 // decoder to use iterators instead of higher-order functions.)
5561 pub fn each_attr<F>(tcx: &ctxt, did: DefId, mut f: F) -> bool where
5562 F: FnMut(&ast::Attribute) -> bool,
5565 let item = tcx.map.expect_item(did.node);
5566 item.attrs.iter().all(|attr| f(attr))
5568 info!("getting foreign attrs");
5569 let mut cont = true;
5570 csearch::get_item_attrs(&tcx.sess.cstore, did, |attrs| {
5572 cont = attrs.iter().all(|attr| f(attr));
5580 /// Determine whether an item is annotated with an attribute
5581 pub fn has_attr(tcx: &ctxt, did: DefId, attr: &str) -> bool {
5582 let mut found = false;
5583 each_attr(tcx, did, |item| {
5584 if item.check_name(attr) {
5594 /// Determine whether an item is annotated with `#[repr(packed)]`
5595 pub fn lookup_packed(tcx: &ctxt, did: DefId) -> bool {
5596 lookup_repr_hints(tcx, did).contains(&attr::ReprPacked)
5599 /// Determine whether an item is annotated with `#[simd]`
5600 pub fn lookup_simd(tcx: &ctxt, did: DefId) -> bool {
5601 has_attr(tcx, did, "simd")
5604 /// Obtain the representation annotation for a struct definition.
5605 pub fn lookup_repr_hints(tcx: &ctxt, did: DefId) -> Rc<Vec<attr::ReprAttr>> {
5606 memoized(&tcx.repr_hint_cache, did, |did: DefId| {
5607 Rc::new(if did.krate == LOCAL_CRATE {
5608 let mut acc = Vec::new();
5609 ty::each_attr(tcx, did, |meta| {
5610 acc.extend(attr::find_repr_attrs(tcx.sess.diagnostic(),
5616 csearch::get_repr_attrs(&tcx.sess.cstore, did)
5621 // Look up a field ID, whether or not it's local
5622 // Takes a list of type substs in case the struct is generic
5623 pub fn lookup_field_type<'tcx>(tcx: &ctxt<'tcx>,
5626 substs: &Substs<'tcx>)
5628 let ty = if id.krate == ast::LOCAL_CRATE {
5629 node_id_to_type(tcx, id.node)
5631 let mut tcache = tcx.tcache.borrow_mut();
5632 let pty = tcache.entry(&id).get().unwrap_or_else(
5633 |vacant_entry| vacant_entry.insert(csearch::get_field_type(tcx, struct_id, id)));
5636 ty.subst(tcx, substs)
5639 // Look up the list of field names and IDs for a given struct.
5640 // Panics if the id is not bound to a struct.
5641 pub fn lookup_struct_fields(cx: &ctxt, did: ast::DefId) -> Vec<field_ty> {
5642 if did.krate == ast::LOCAL_CRATE {
5643 let struct_fields = cx.struct_fields.borrow();
5644 match struct_fields.get(&did) {
5645 Some(fields) => (**fields).clone(),
5648 format!("ID not mapped to struct fields: {}",
5649 cx.map.node_to_string(did.node))[]);
5653 csearch::get_struct_fields(&cx.sess.cstore, did)
5657 pub fn is_tuple_struct(cx: &ctxt, did: ast::DefId) -> bool {
5658 let fields = lookup_struct_fields(cx, did);
5659 !fields.is_empty() && fields.iter().all(|f| f.name == token::special_names::unnamed_field)
5662 // Returns a list of fields corresponding to the struct's items. trans uses
5663 // this. Takes a list of substs with which to instantiate field types.
5664 pub fn struct_fields<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId, substs: &Substs<'tcx>)
5665 -> Vec<field<'tcx>> {
5666 lookup_struct_fields(cx, did).iter().map(|f| {
5670 ty: lookup_field_type(cx, did, f.id, substs),
5677 // Returns a list of fields corresponding to the tuple's items. trans uses
5679 pub fn tup_fields<'tcx>(v: &[Ty<'tcx>]) -> Vec<field<'tcx>> {
5680 v.iter().enumerate().map(|(i, &f)| {
5682 name: token::intern(i.to_string()[]),
5691 #[derive(Copy, Clone)]
5692 pub struct UnboxedClosureUpvar<'tcx> {
5698 // Returns a list of `UnboxedClosureUpvar`s for each upvar.
5699 pub fn unboxed_closure_upvars<'tcx>(typer: &mc::Typer<'tcx>,
5700 closure_id: ast::DefId,
5701 substs: &Substs<'tcx>)
5702 -> Option<Vec<UnboxedClosureUpvar<'tcx>>>
5704 // Presently an unboxed closure type cannot "escape" out of a
5705 // function, so we will only encounter ones that originated in the
5706 // local crate or were inlined into it along with some function.
5707 // This may change if abstract return types of some sort are
5709 assert!(closure_id.krate == ast::LOCAL_CRATE);
5710 let tcx = typer.tcx();
5711 let capture_mode = tcx.capture_modes.borrow()[closure_id.node].clone();
5712 match tcx.freevars.borrow().get(&closure_id.node) {
5713 None => Some(vec![]),
5714 Some(ref freevars) => {
5717 let freevar_def_id = freevar.def.def_id();
5718 let freevar_ty = match typer.node_ty(freevar_def_id.node) {
5720 Err(()) => { return None; }
5722 let freevar_ty = freevar_ty.subst(tcx, substs);
5724 match capture_mode {
5725 ast::CaptureByValue => {
5726 Some(UnboxedClosureUpvar { def: freevar.def,
5731 ast::CaptureByRef => {
5732 let upvar_id = ty::UpvarId {
5733 var_id: freevar_def_id.node,
5734 closure_expr_id: closure_id.node
5738 let freevar_ref_ty = match typer.upvar_borrow(upvar_id) {
5741 tcx.mk_region(borrow.region),
5744 mutbl: borrow.kind.to_mutbl_lossy(),
5748 // FIXME(#16640) we should really return None here;
5749 // but that requires better inference integration,
5750 // for now gin up something.
5754 Some(UnboxedClosureUpvar {
5767 pub fn is_binopable<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>, op: ast::BinOp) -> bool {
5768 #![allow(non_upper_case_globals)]
5769 static tycat_other: int = 0;
5770 static tycat_bool: int = 1;
5771 static tycat_char: int = 2;
5772 static tycat_int: int = 3;
5773 static tycat_float: int = 4;
5774 static tycat_raw_ptr: int = 6;
5776 static opcat_add: int = 0;
5777 static opcat_sub: int = 1;
5778 static opcat_mult: int = 2;
5779 static opcat_shift: int = 3;
5780 static opcat_rel: int = 4;
5781 static opcat_eq: int = 5;
5782 static opcat_bit: int = 6;
5783 static opcat_logic: int = 7;
5784 static opcat_mod: int = 8;
5786 fn opcat(op: ast::BinOp) -> int {
5788 ast::BiAdd => opcat_add,
5789 ast::BiSub => opcat_sub,
5790 ast::BiMul => opcat_mult,
5791 ast::BiDiv => opcat_mult,
5792 ast::BiRem => opcat_mod,
5793 ast::BiAnd => opcat_logic,
5794 ast::BiOr => opcat_logic,
5795 ast::BiBitXor => opcat_bit,
5796 ast::BiBitAnd => opcat_bit,
5797 ast::BiBitOr => opcat_bit,
5798 ast::BiShl => opcat_shift,
5799 ast::BiShr => opcat_shift,
5800 ast::BiEq => opcat_eq,
5801 ast::BiNe => opcat_eq,
5802 ast::BiLt => opcat_rel,
5803 ast::BiLe => opcat_rel,
5804 ast::BiGe => opcat_rel,
5805 ast::BiGt => opcat_rel
5809 fn tycat<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> int {
5810 if type_is_simd(cx, ty) {
5811 return tycat(cx, simd_type(cx, ty))
5814 ty_char => tycat_char,
5815 ty_bool => tycat_bool,
5816 ty_int(_) | ty_uint(_) | ty_infer(IntVar(_)) => tycat_int,
5817 ty_float(_) | ty_infer(FloatVar(_)) => tycat_float,
5818 ty_ptr(_) => tycat_raw_ptr,
5823 static t: bool = true;
5824 static f: bool = false;
5827 // +, -, *, shift, rel, ==, bit, logic, mod
5828 /*other*/ [f, f, f, f, f, f, f, f, f],
5829 /*bool*/ [f, f, f, f, t, t, t, t, f],
5830 /*char*/ [f, f, f, f, t, t, f, f, f],
5831 /*int*/ [t, t, t, t, t, t, t, f, t],
5832 /*float*/ [t, t, t, f, t, t, f, f, f],
5833 /*bot*/ [t, t, t, t, t, t, t, t, t],
5834 /*raw ptr*/ [f, f, f, f, t, t, f, f, f]];
5836 return tbl[tycat(cx, ty) as uint ][opcat(op) as uint];
5839 /// Returns an equivalent type with all the typedefs and self regions removed.
5840 pub fn normalize_ty<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
5841 let u = TypeNormalizer(cx).fold_ty(ty);
5844 struct TypeNormalizer<'a, 'tcx: 'a>(&'a ctxt<'tcx>);
5846 impl<'a, 'tcx> TypeFolder<'tcx> for TypeNormalizer<'a, 'tcx> {
5847 fn tcx(&self) -> &ctxt<'tcx> { let TypeNormalizer(c) = *self; c }
5849 fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> {
5850 match self.tcx().normalized_cache.borrow().get(&ty).cloned() {
5855 let t_norm = ty_fold::super_fold_ty(self, ty);
5856 self.tcx().normalized_cache.borrow_mut().insert(ty, t_norm);
5860 fn fold_region(&mut self, _: ty::Region) -> ty::Region {
5864 fn fold_substs(&mut self,
5865 substs: &subst::Substs<'tcx>)
5866 -> subst::Substs<'tcx> {
5867 subst::Substs { regions: subst::ErasedRegions,
5868 types: substs.types.fold_with(self) }
5873 // Returns the repeat count for a repeating vector expression.
5874 pub fn eval_repeat_count(tcx: &ctxt, count_expr: &ast::Expr) -> uint {
5875 match const_eval::eval_const_expr_partial(tcx, count_expr) {
5877 let found = match val {
5878 const_eval::const_uint(count) => return count as uint,
5879 const_eval::const_int(count) if count >= 0 => return count as uint,
5880 const_eval::const_int(_) =>
5882 const_eval::const_float(_) =>
5884 const_eval::const_str(_) =>
5886 const_eval::const_bool(_) =>
5888 const_eval::const_binary(_) =>
5891 tcx.sess.span_err(count_expr.span, format!(
5892 "expected positive integer for repeat count, found {}",
5896 let found = match count_expr.node {
5897 ast::ExprPath(ast::Path {
5901 }) if segments.len() == 1 =>
5904 "non-constant expression"
5906 tcx.sess.span_err(count_expr.span, format!(
5907 "expected constant integer for repeat count, found {}",
5914 // Iterate over a type parameter's bounded traits and any supertraits
5915 // of those traits, ignoring kinds.
5916 // Here, the supertraits are the transitive closure of the supertrait
5917 // relation on the supertraits from each bounded trait's constraint
5919 pub fn each_bound_trait_and_supertraits<'tcx, F>(tcx: &ctxt<'tcx>,
5920 bounds: &[PolyTraitRef<'tcx>],
5923 F: FnMut(PolyTraitRef<'tcx>) -> bool,
5925 for bound_trait_ref in traits::transitive_bounds(tcx, bounds) {
5926 if !f(bound_trait_ref) {
5933 pub fn object_region_bounds<'tcx>(
5935 opt_principal: Option<&PolyTraitRef<'tcx>>, // None for closures
5936 others: BuiltinBounds)
5939 // Since we don't actually *know* the self type for an object,
5940 // this "open(err)" serves as a kind of dummy standin -- basically
5941 // a skolemized type.
5942 let open_ty = ty::mk_infer(tcx, FreshTy(0));
5944 let opt_trait_ref = opt_principal.map_or(Vec::new(), |principal| {
5945 // Note that we preserve the overall binding levels here.
5946 assert!(!open_ty.has_escaping_regions());
5947 let substs = tcx.mk_substs(principal.0.substs.with_self_ty(open_ty));
5948 vec!(ty::Binder(Rc::new(ty::TraitRef::new(principal.0.def_id, substs))))
5951 let param_bounds = ty::ParamBounds {
5952 region_bounds: Vec::new(),
5953 builtin_bounds: others,
5954 trait_bounds: opt_trait_ref,
5955 projection_bounds: Vec::new(), // not relevant to computing region bounds
5958 let predicates = ty::predicates(tcx, open_ty, ¶m_bounds);
5959 ty::required_region_bounds(tcx, open_ty, predicates)
5962 /// Given a set of predicates that apply to an object type, returns
5963 /// the region bounds that the (erased) `Self` type must
5964 /// outlive. Precisely *because* the `Self` type is erased, the
5965 /// parameter `erased_self_ty` must be supplied to indicate what type
5966 /// has been used to represent `Self` in the predicates
5967 /// themselves. This should really be a unique type; `FreshTy(0)` is a
5968 /// popular choice (see `object_region_bounds` above).
5970 /// Requires that trait definitions have been processed so that we can
5971 /// elaborate predicates and walk supertraits.
5972 pub fn required_region_bounds<'tcx>(tcx: &ctxt<'tcx>,
5973 erased_self_ty: Ty<'tcx>,
5974 predicates: Vec<ty::Predicate<'tcx>>)
5977 debug!("required_region_bounds(erased_self_ty={}, predicates={})",
5978 erased_self_ty.repr(tcx),
5979 predicates.repr(tcx));
5981 assert!(!erased_self_ty.has_escaping_regions());
5983 traits::elaborate_predicates(tcx, predicates)
5984 .filter_map(|predicate| {
5986 ty::Predicate::Projection(..) |
5987 ty::Predicate::Trait(..) |
5988 ty::Predicate::Equate(..) |
5989 ty::Predicate::RegionOutlives(..) => {
5992 ty::Predicate::TypeOutlives(ty::Binder(ty::OutlivesPredicate(t, r))) => {
5993 // Search for a bound of the form `erased_self_ty
5994 // : 'a`, but be wary of something like `for<'a>
5995 // erased_self_ty : 'a` (we interpret a
5996 // higher-ranked bound like that as 'static,
5997 // though at present the code in `fulfill.rs`
5998 // considers such bounds to be unsatisfiable, so
5999 // it's kind of a moot point since you could never
6000 // construct such an object, but this seems
6001 // correct even if that code changes).
6002 if t == erased_self_ty && !r.has_escaping_regions() {
6003 if r.has_escaping_regions() {
6017 pub fn get_tydesc_ty<'tcx>(tcx: &ctxt<'tcx>) -> Result<Ty<'tcx>, String> {
6018 tcx.lang_items.require(TyDescStructLangItem).map(|tydesc_lang_item| {
6019 tcx.intrinsic_defs.borrow().get(&tydesc_lang_item).cloned()
6020 .expect("Failed to resolve TyDesc")
6024 pub fn item_variances(tcx: &ctxt, item_id: ast::DefId) -> Rc<ItemVariances> {
6025 lookup_locally_or_in_crate_store(
6026 "item_variance_map", item_id, &mut *tcx.item_variance_map.borrow_mut(),
6027 || Rc::new(csearch::get_item_variances(&tcx.sess.cstore, item_id)))
6030 /// Records a trait-to-implementation mapping.
6031 pub fn record_trait_implementation(tcx: &ctxt,
6032 trait_def_id: DefId,
6033 impl_def_id: DefId) {
6034 match tcx.trait_impls.borrow().get(&trait_def_id) {
6035 Some(impls_for_trait) => {
6036 impls_for_trait.borrow_mut().push(impl_def_id);
6041 tcx.trait_impls.borrow_mut().insert(trait_def_id, Rc::new(RefCell::new(vec!(impl_def_id))));
6044 /// Populates the type context with all the implementations for the given type
6046 pub fn populate_implementations_for_type_if_necessary(tcx: &ctxt,
6047 type_id: ast::DefId) {
6048 if type_id.krate == LOCAL_CRATE {
6051 if tcx.populated_external_types.borrow().contains(&type_id) {
6055 debug!("populate_implementations_for_type_if_necessary: searching for {}", type_id);
6057 let mut inherent_impls = Vec::new();
6058 csearch::each_implementation_for_type(&tcx.sess.cstore, type_id,
6060 let impl_items = csearch::get_impl_items(&tcx.sess.cstore, impl_def_id);
6062 // Record the trait->implementation mappings, if applicable.
6063 let associated_traits = csearch::get_impl_trait(tcx, impl_def_id);
6064 for trait_ref in associated_traits.iter() {
6065 record_trait_implementation(tcx, trait_ref.def_id, impl_def_id);
6068 // For any methods that use a default implementation, add them to
6069 // the map. This is a bit unfortunate.
6070 for impl_item_def_id in impl_items.iter() {
6071 let method_def_id = impl_item_def_id.def_id();
6072 match impl_or_trait_item(tcx, method_def_id) {
6073 MethodTraitItem(method) => {
6074 for &source in method.provided_source.iter() {
6075 tcx.provided_method_sources
6077 .insert(method_def_id, source);
6080 TypeTraitItem(_) => {}
6084 // Store the implementation info.
6085 tcx.impl_items.borrow_mut().insert(impl_def_id, impl_items);
6087 // If this is an inherent implementation, record it.
6088 if associated_traits.is_none() {
6089 inherent_impls.push(impl_def_id);
6093 tcx.inherent_impls.borrow_mut().insert(type_id, Rc::new(inherent_impls));
6094 tcx.populated_external_types.borrow_mut().insert(type_id);
6097 /// Populates the type context with all the implementations for the given
6098 /// trait if necessary.
6099 pub fn populate_implementations_for_trait_if_necessary(
6101 trait_id: ast::DefId) {
6102 if trait_id.krate == LOCAL_CRATE {
6105 if tcx.populated_external_traits.borrow().contains(&trait_id) {
6109 csearch::each_implementation_for_trait(&tcx.sess.cstore, trait_id,
6110 |implementation_def_id| {
6111 let impl_items = csearch::get_impl_items(&tcx.sess.cstore, implementation_def_id);
6113 // Record the trait->implementation mapping.
6114 record_trait_implementation(tcx, trait_id, implementation_def_id);
6116 // For any methods that use a default implementation, add them to
6117 // the map. This is a bit unfortunate.
6118 for impl_item_def_id in impl_items.iter() {
6119 let method_def_id = impl_item_def_id.def_id();
6120 match impl_or_trait_item(tcx, method_def_id) {
6121 MethodTraitItem(method) => {
6122 for &source in method.provided_source.iter() {
6123 tcx.provided_method_sources
6125 .insert(method_def_id, source);
6128 TypeTraitItem(_) => {}
6132 // Store the implementation info.
6133 tcx.impl_items.borrow_mut().insert(implementation_def_id, impl_items);
6136 tcx.populated_external_traits.borrow_mut().insert(trait_id);
6139 /// Given the def_id of an impl, return the def_id of the trait it implements.
6140 /// If it implements no trait, return `None`.
6141 pub fn trait_id_of_impl(tcx: &ctxt,
6143 -> Option<ast::DefId> {
6144 ty::impl_trait_ref(tcx, def_id).map(|tr| tr.def_id)
6147 /// If the given def ID describes a method belonging to an impl, return the
6148 /// ID of the impl that the method belongs to. Otherwise, return `None`.
6149 pub fn impl_of_method(tcx: &ctxt, def_id: ast::DefId)
6150 -> Option<ast::DefId> {
6151 if def_id.krate != LOCAL_CRATE {
6152 return match csearch::get_impl_or_trait_item(tcx,
6153 def_id).container() {
6154 TraitContainer(_) => None,
6155 ImplContainer(def_id) => Some(def_id),
6158 match tcx.impl_or_trait_items.borrow().get(&def_id).cloned() {
6159 Some(trait_item) => {
6160 match trait_item.container() {
6161 TraitContainer(_) => None,
6162 ImplContainer(def_id) => Some(def_id),
6169 /// If the given def ID describes an item belonging to a trait (either a
6170 /// default method or an implementation of a trait method), return the ID of
6171 /// the trait that the method belongs to. Otherwise, return `None`.
6172 pub fn trait_of_item(tcx: &ctxt, def_id: ast::DefId) -> Option<ast::DefId> {
6173 if def_id.krate != LOCAL_CRATE {
6174 return csearch::get_trait_of_item(&tcx.sess.cstore, def_id, tcx);
6176 match tcx.impl_or_trait_items.borrow().get(&def_id).cloned() {
6177 Some(impl_or_trait_item) => {
6178 match impl_or_trait_item.container() {
6179 TraitContainer(def_id) => Some(def_id),
6180 ImplContainer(def_id) => trait_id_of_impl(tcx, def_id),
6187 /// If the given def ID describes an item belonging to a trait, (either a
6188 /// default method or an implementation of a trait method), return the ID of
6189 /// the method inside trait definition (this means that if the given def ID
6190 /// is already that of the original trait method, then the return value is
6192 /// Otherwise, return `None`.
6193 pub fn trait_item_of_item(tcx: &ctxt, def_id: ast::DefId)
6194 -> Option<ImplOrTraitItemId> {
6195 let impl_item = match tcx.impl_or_trait_items.borrow().get(&def_id) {
6196 Some(m) => m.clone(),
6197 None => return None,
6199 let name = impl_item.name();
6200 match trait_of_item(tcx, def_id) {
6201 Some(trait_did) => {
6202 let trait_items = ty::trait_items(tcx, trait_did);
6204 .position(|m| m.name() == name)
6205 .map(|idx| ty::trait_item(tcx, trait_did, idx).id())
6211 /// Creates a hash of the type `Ty` which will be the same no matter what crate
6212 /// context it's calculated within. This is used by the `type_id` intrinsic.
6213 pub fn hash_crate_independent<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>, svh: &Svh) -> u64 {
6214 let mut state = sip::SipState::new();
6215 helper(tcx, ty, svh, &mut state);
6216 return state.result();
6218 fn helper<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>, svh: &Svh, state: &mut sip::SipState) {
6219 macro_rules! byte( ($b:expr) => { ($b as u8).hash(state) } );
6220 macro_rules! hash( ($e:expr) => { $e.hash(state) } );
6222 let region = |&: state: &mut sip::SipState, r: Region| {
6225 ReLateBound(db, BrAnon(i)) => {
6235 tcx.sess.bug("unexpected region found when hashing a type")
6239 let did = |&: state: &mut sip::SipState, did: DefId| {
6240 let h = if ast_util::is_local(did) {
6243 tcx.sess.cstore.get_crate_hash(did.krate)
6245 h.as_str().hash(state);
6246 did.node.hash(state);
6248 let mt = |&: state: &mut sip::SipState, mt: mt| {
6249 mt.mutbl.hash(state);
6251 let fn_sig = |&: state: &mut sip::SipState, sig: &Binder<FnSig<'tcx>>| {
6252 let sig = anonymize_late_bound_regions(tcx, sig);
6253 for a in sig.inputs.iter() { helper(tcx, *a, svh, state); }
6254 if let ty::FnConverging(output) = sig.output {
6255 helper(tcx, output, svh, state);
6258 maybe_walk_ty(ty, |ty| {
6260 ty_bool => byte!(2),
6261 ty_char => byte!(3),
6284 ty_vec(_, Some(n)) => {
6288 ty_vec(_, None) => {
6300 ty_bare_fn(opt_def_id, ref b) => {
6305 fn_sig(state, &b.sig);
6308 ty_trait(ref data) => {
6310 did(state, data.principal_def_id());
6313 let principal = anonymize_late_bound_regions(tcx, &data.principal);
6314 for subty in principal.substs.types.iter() {
6315 helper(tcx, *subty, svh, state);
6320 ty_struct(d, _) => {
6324 ty_tup(ref inner) => {
6332 hash!(token::get_name(p.name));
6334 ty_open(_) => byte!(22),
6335 ty_infer(_) => unreachable!(),
6336 ty_err => byte!(23),
6337 ty_unboxed_closure(d, r, _) => {
6342 ty_projection(ref data) => {
6344 did(state, data.trait_ref.def_id);
6345 hash!(token::get_name(data.item_name));
6354 pub fn to_string(self) -> &'static str {
6357 Contravariant => "-",
6364 /// Construct a parameter environment suitable for static contexts or other contexts where there
6365 /// are no free type/lifetime parameters in scope.
6366 pub fn empty_parameter_environment<'a,'tcx>(cx: &'a ctxt<'tcx>) -> ParameterEnvironment<'a,'tcx> {
6367 ty::ParameterEnvironment { tcx: cx,
6368 free_substs: Substs::empty(),
6369 caller_bounds: GenericBounds::empty(),
6370 implicit_region_bound: ty::ReEmpty,
6371 selection_cache: traits::SelectionCache::new(), }
6374 /// See `ParameterEnvironment` struct def'n for details
6375 pub fn construct_parameter_environment<'a,'tcx>(
6376 tcx: &'a ctxt<'tcx>,
6377 generics: &ty::Generics<'tcx>,
6378 free_id: ast::NodeId)
6379 -> ParameterEnvironment<'a, 'tcx>
6383 // Construct the free substs.
6387 let mut types = VecPerParamSpace::empty();
6388 push_types_from_defs(tcx, &mut types, generics.types.as_slice());
6390 // map bound 'a => free 'a
6391 let mut regions = VecPerParamSpace::empty();
6392 push_region_params(&mut regions, free_id, generics.regions.as_slice());
6394 let free_substs = Substs {
6396 regions: subst::NonerasedRegions(regions)
6399 let free_id_scope = region::CodeExtent::from_node_id(free_id);
6402 // Compute the bounds on Self and the type parameters.
6405 let bounds = generics.to_bounds(tcx, &free_substs);
6406 let bounds = liberate_late_bound_regions(tcx, free_id_scope, &ty::Binder(bounds));
6409 // Compute region bounds. For now, these relations are stored in a
6410 // global table on the tcx, so just enter them there. I'm not
6411 // crazy about this scheme, but it's convenient, at least.
6414 record_region_bounds(tcx, &bounds);
6416 debug!("construct_parameter_environment: free_id={} free_subst={} bounds={}",
6418 free_substs.repr(tcx),
6421 return ty::ParameterEnvironment {
6423 free_substs: free_substs,
6424 implicit_region_bound: ty::ReScope(free_id_scope),
6425 caller_bounds: bounds,
6426 selection_cache: traits::SelectionCache::new(),
6429 fn push_region_params(regions: &mut VecPerParamSpace<ty::Region>,
6430 free_id: ast::NodeId,
6431 region_params: &[RegionParameterDef])
6433 for r in region_params.iter() {
6434 regions.push(r.space, ty::free_region_from_def(free_id, r));
6438 fn push_types_from_defs<'tcx>(tcx: &ty::ctxt<'tcx>,
6439 types: &mut VecPerParamSpace<Ty<'tcx>>,
6440 defs: &[TypeParameterDef<'tcx>]) {
6441 for def in defs.iter() {
6442 debug!("construct_parameter_environment(): push_types_from_defs: def={}",
6444 let ty = ty::mk_param_from_def(tcx, def);
6445 types.push(def.space, ty);
6449 fn record_region_bounds<'tcx>(tcx: &ty::ctxt<'tcx>, bounds: &GenericBounds<'tcx>) {
6450 debug!("record_region_bounds(bounds={})", bounds.repr(tcx));
6452 for predicate in bounds.predicates.iter() {
6454 Predicate::Projection(..) |
6455 Predicate::Trait(..) |
6456 Predicate::Equate(..) |
6457 Predicate::TypeOutlives(..) => {
6458 // No region bounds here
6460 Predicate::RegionOutlives(ty::Binder(ty::OutlivesPredicate(r_a, r_b))) => {
6462 (ty::ReFree(fr_a), ty::ReFree(fr_b)) => {
6463 // Record that `'a:'b`. Or, put another way, `'b <= 'a`.
6464 tcx.region_maps.relate_free_regions(fr_b, fr_a);
6467 // All named regions are instantiated with free regions.
6469 format!("record_region_bounds: non free region: {} / {}",
6471 r_b.repr(tcx)).as_slice());
6481 pub fn from_mutbl(m: ast::Mutability) -> BorrowKind {
6483 ast::MutMutable => MutBorrow,
6484 ast::MutImmutable => ImmBorrow,
6488 /// Returns a mutability `m` such that an `&m T` pointer could be used to obtain this borrow
6489 /// kind. Because borrow kinds are richer than mutabilities, we sometimes have to pick a
6490 /// mutability that is stronger than necessary so that it at least *would permit* the borrow in
6492 pub fn to_mutbl_lossy(self) -> ast::Mutability {
6494 MutBorrow => ast::MutMutable,
6495 ImmBorrow => ast::MutImmutable,
6497 // We have no type corresponding to a unique imm borrow, so
6498 // use `&mut`. It gives all the capabilities of an `&uniq`
6499 // and hence is a safe "over approximation".
6500 UniqueImmBorrow => ast::MutMutable,
6504 pub fn to_user_str(&self) -> &'static str {
6506 MutBorrow => "mutable",
6507 ImmBorrow => "immutable",
6508 UniqueImmBorrow => "uniquely immutable",
6513 impl<'tcx> ctxt<'tcx> {
6514 pub fn capture_mode(&self, closure_expr_id: ast::NodeId)
6515 -> ast::CaptureClause {
6516 self.capture_modes.borrow()[closure_expr_id].clone()
6519 pub fn is_method_call(&self, expr_id: ast::NodeId) -> bool {
6520 self.method_map.borrow().contains_key(&MethodCall::expr(expr_id))
6524 impl<'a,'tcx> mc::Typer<'tcx> for ParameterEnvironment<'a,'tcx> {
6525 fn tcx(&self) -> &ty::ctxt<'tcx> {
6529 fn node_ty(&self, id: ast::NodeId) -> mc::McResult<Ty<'tcx>> {
6530 Ok(ty::node_id_to_type(self.tcx, id))
6533 fn expr_ty_adjusted(&self, expr: &ast::Expr) -> mc::McResult<Ty<'tcx>> {
6534 Ok(ty::expr_ty_adjusted(self.tcx, expr))
6537 fn node_method_ty(&self, method_call: ty::MethodCall) -> Option<Ty<'tcx>> {
6538 self.tcx.method_map.borrow().get(&method_call).map(|method| method.ty)
6541 fn node_method_origin(&self, method_call: ty::MethodCall)
6542 -> Option<ty::MethodOrigin<'tcx>>
6544 self.tcx.method_map.borrow().get(&method_call).map(|method| method.origin.clone())
6547 fn adjustments(&self) -> &RefCell<NodeMap<ty::AutoAdjustment<'tcx>>> {
6548 &self.tcx.adjustments
6551 fn is_method_call(&self, id: ast::NodeId) -> bool {
6552 self.tcx.is_method_call(id)
6555 fn temporary_scope(&self, rvalue_id: ast::NodeId) -> Option<region::CodeExtent> {
6556 self.tcx.region_maps.temporary_scope(rvalue_id)
6559 fn upvar_borrow(&self, upvar_id: ty::UpvarId) -> Option<ty::UpvarBorrow> {
6560 Some(self.tcx.upvar_borrow_map.borrow()[upvar_id].clone())
6563 fn capture_mode(&self, closure_expr_id: ast::NodeId)
6564 -> ast::CaptureClause {
6565 self.tcx.capture_mode(closure_expr_id)
6568 fn type_moves_by_default(&self, span: Span, ty: Ty<'tcx>) -> bool {
6569 type_moves_by_default(self, span, ty)
6573 impl<'a,'tcx> UnboxedClosureTyper<'tcx> for ty::ParameterEnvironment<'a,'tcx> {
6574 fn param_env<'b>(&'b self) -> &'b ty::ParameterEnvironment<'b,'tcx> {
6578 fn unboxed_closure_kind(&self,
6580 -> ty::UnboxedClosureKind
6582 self.tcx.unboxed_closure_kind(def_id)
6585 fn unboxed_closure_type(&self,
6587 substs: &subst::Substs<'tcx>)
6588 -> ty::ClosureTy<'tcx>
6590 self.tcx.unboxed_closure_type(def_id, substs)
6593 fn unboxed_closure_upvars(&self,
6595 substs: &Substs<'tcx>)
6596 -> Option<Vec<UnboxedClosureUpvar<'tcx>>>
6598 unboxed_closure_upvars(self, def_id, substs)
6603 /// The category of explicit self.
6604 #[derive(Clone, Copy, Eq, PartialEq, Show)]
6605 pub enum ExplicitSelfCategory {
6606 StaticExplicitSelfCategory,
6607 ByValueExplicitSelfCategory,
6608 ByReferenceExplicitSelfCategory(Region, ast::Mutability),
6609 ByBoxExplicitSelfCategory,
6612 /// Pushes all the lifetimes in the given type onto the given list. A
6613 /// "lifetime in a type" is a lifetime specified by a reference or a lifetime
6614 /// in a list of type substitutions. This does *not* traverse into nominal
6615 /// types, nor does it resolve fictitious types.
6616 pub fn accumulate_lifetimes_in_type(accumulator: &mut Vec<ty::Region>,
6620 ty_rptr(region, _) => {
6621 accumulator.push(*region)
6623 ty_trait(ref t) => {
6624 accumulator.push_all(t.principal.0.substs.regions().as_slice());
6626 ty_enum(_, substs) |
6627 ty_struct(_, substs) => {
6628 accum_substs(accumulator, substs);
6630 ty_unboxed_closure(_, region, substs) => {
6631 accumulator.push(*region);
6632 accum_substs(accumulator, substs);
6654 fn accum_substs(accumulator: &mut Vec<Region>, substs: &Substs) {
6655 match substs.regions {
6656 subst::ErasedRegions => {}
6657 subst::NonerasedRegions(ref regions) => {
6658 for region in regions.iter() {
6659 accumulator.push(*region)
6666 /// A free variable referred to in a function.
6667 #[derive(Copy, RustcEncodable, RustcDecodable)]
6668 pub struct Freevar {
6669 /// The variable being accessed free.
6672 // First span where it is accessed (there can be multiple).
6676 pub type FreevarMap = NodeMap<Vec<Freevar>>;
6678 pub type CaptureModeMap = NodeMap<ast::CaptureClause>;
6680 // Trait method resolution
6681 pub type TraitMap = NodeMap<Vec<DefId>>;
6683 // Map from the NodeId of a glob import to a list of items which are actually
6685 pub type GlobMap = HashMap<NodeId, HashSet<Name>>;
6687 pub fn with_freevars<T, F>(tcx: &ty::ctxt, fid: ast::NodeId, f: F) -> T where
6688 F: FnOnce(&[Freevar]) -> T,
6690 match tcx.freevars.borrow().get(&fid) {
6696 impl<'tcx> AutoAdjustment<'tcx> {
6697 pub fn is_identity(&self) -> bool {
6699 AdjustAddEnv(..) => false,
6700 AdjustReifyFnPointer(..) => false,
6701 AdjustDerefRef(ref r) => r.is_identity(),
6706 impl<'tcx> AutoDerefRef<'tcx> {
6707 pub fn is_identity(&self) -> bool {
6708 self.autoderefs == 0 && self.autoref.is_none()
6712 /// Replace any late-bound regions bound in `value` with free variants attached to scope-id
6714 pub fn liberate_late_bound_regions<'tcx, T>(
6715 tcx: &ty::ctxt<'tcx>,
6716 scope: region::CodeExtent,
6719 where T : TypeFoldable<'tcx> + Repr<'tcx>
6721 replace_late_bound_regions(
6723 |br, _| ty::ReFree(ty::FreeRegion{scope: scope, bound_region: br})).0
6726 pub fn count_late_bound_regions<'tcx, T>(
6727 tcx: &ty::ctxt<'tcx>,
6730 where T : TypeFoldable<'tcx> + Repr<'tcx>
6732 let (_, skol_map) = replace_late_bound_regions(tcx, value, |_, _| ty::ReStatic);
6736 pub fn binds_late_bound_regions<'tcx, T>(
6737 tcx: &ty::ctxt<'tcx>,
6740 where T : TypeFoldable<'tcx> + Repr<'tcx>
6742 count_late_bound_regions(tcx, value) > 0
6745 /// Replace any late-bound regions bound in `value` with `'static`. Useful in trans but also
6746 /// method lookup and a few other places where precise region relationships are not required.
6747 pub fn erase_late_bound_regions<'tcx, T>(
6748 tcx: &ty::ctxt<'tcx>,
6751 where T : TypeFoldable<'tcx> + Repr<'tcx>
6753 replace_late_bound_regions(tcx, value, |_, _| ty::ReStatic).0
6756 /// Rewrite any late-bound regions so that they are anonymous. Region numbers are
6757 /// assigned starting at 1 and increasing monotonically in the order traversed
6758 /// by the fold operation.
6760 /// The chief purpose of this function is to canonicalize regions so that two
6761 /// `FnSig`s or `TraitRef`s which are equivalent up to region naming will become
6762 /// structurally identical. For example, `for<'a, 'b> fn(&'a int, &'b int)` and
6763 /// `for<'a, 'b> fn(&'b int, &'a int)` will become identical after anonymization.
6764 pub fn anonymize_late_bound_regions<'tcx, T>(
6768 where T : TypeFoldable<'tcx> + Repr<'tcx>,
6770 let mut counter = 0;
6771 replace_late_bound_regions(tcx, sig, |_, db| {
6773 ReLateBound(db, BrAnon(counter))
6777 /// Replaces the late-bound-regions in `value` that are bound by `value`.
6778 pub fn replace_late_bound_regions<'tcx, T, F>(
6779 tcx: &ty::ctxt<'tcx>,
6782 -> (T, FnvHashMap<ty::BoundRegion,ty::Region>)
6783 where T : TypeFoldable<'tcx> + Repr<'tcx>,
6784 F : FnMut(BoundRegion, DebruijnIndex) -> ty::Region,
6786 debug!("replace_late_bound_regions({})", binder.repr(tcx));
6788 let mut map = FnvHashMap::new();
6790 // Note: fold the field `0`, not the binder, so that late-bound
6791 // regions bound by `binder` are considered free.
6792 let value = ty_fold::fold_regions(tcx, &binder.0, |region, current_depth| {
6793 debug!("region={}", region.repr(tcx));
6795 ty::ReLateBound(debruijn, br) if debruijn.depth == current_depth => {
6796 * map.entry(&br).get().unwrap_or_else(
6797 |vacant_entry| vacant_entry.insert(mapf(br, debruijn)))
6805 debug!("resulting map: {} value: {}", map, value.repr(tcx));
6809 impl DebruijnIndex {
6810 pub fn new(depth: u32) -> DebruijnIndex {
6812 DebruijnIndex { depth: depth }
6815 pub fn shifted(&self, amount: u32) -> DebruijnIndex {
6816 DebruijnIndex { depth: self.depth + amount }
6820 impl<'tcx> Repr<'tcx> for AutoAdjustment<'tcx> {
6821 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6823 AdjustAddEnv(def_id, ref trait_store) => {
6824 format!("AdjustAddEnv({},{})", def_id.repr(tcx), trait_store)
6826 AdjustReifyFnPointer(def_id) => {
6827 format!("AdjustAddEnv({})", def_id.repr(tcx))
6829 AdjustDerefRef(ref data) => {
6836 impl<'tcx> Repr<'tcx> for UnsizeKind<'tcx> {
6837 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6839 UnsizeLength(n) => format!("UnsizeLength({})", n),
6840 UnsizeStruct(ref k, n) => format!("UnsizeStruct({},{})", k.repr(tcx), n),
6841 UnsizeVtable(ref a, ref b) => format!("UnsizeVtable({},{})", a.repr(tcx), b.repr(tcx)),
6846 impl<'tcx> Repr<'tcx> for AutoDerefRef<'tcx> {
6847 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6848 format!("AutoDerefRef({}, {})", self.autoderefs, self.autoref.repr(tcx))
6852 impl<'tcx> Repr<'tcx> for AutoRef<'tcx> {
6853 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6855 AutoPtr(a, b, ref c) => {
6856 format!("AutoPtr({},{},{})", a.repr(tcx), b, c.repr(tcx))
6858 AutoUnsize(ref a) => {
6859 format!("AutoUnsize({})", a.repr(tcx))
6861 AutoUnsizeUniq(ref a) => {
6862 format!("AutoUnsizeUniq({})", a.repr(tcx))
6864 AutoUnsafe(ref a, ref b) => {
6865 format!("AutoUnsafe({},{})", a, b.repr(tcx))
6871 impl<'tcx> Repr<'tcx> for TyTrait<'tcx> {
6872 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6873 format!("TyTrait({},{})",
6874 self.principal.repr(tcx),
6875 self.bounds.repr(tcx))
6879 impl<'tcx> Repr<'tcx> for ty::Predicate<'tcx> {
6880 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6882 Predicate::Trait(ref a) => a.repr(tcx),
6883 Predicate::Equate(ref pair) => pair.repr(tcx),
6884 Predicate::RegionOutlives(ref pair) => pair.repr(tcx),
6885 Predicate::TypeOutlives(ref pair) => pair.repr(tcx),
6886 Predicate::Projection(ref pair) => pair.repr(tcx),
6891 impl<'tcx> Repr<'tcx> for vtable_origin<'tcx> {
6892 fn repr(&self, tcx: &ty::ctxt<'tcx>) -> String {
6894 vtable_static(def_id, ref tys, ref vtable_res) => {
6895 format!("vtable_static({}:{}, {}, {})",
6897 ty::item_path_str(tcx, def_id),
6899 vtable_res.repr(tcx))
6902 vtable_param(x, y) => {
6903 format!("vtable_param({}, {})", x, y)
6906 vtable_unboxed_closure(def_id) => {
6907 format!("vtable_unboxed_closure({})", def_id)
6911 format!("vtable_error")
6917 pub fn make_substs_for_receiver_types<'tcx>(tcx: &ty::ctxt<'tcx>,
6918 trait_ref: &ty::TraitRef<'tcx>,
6919 method: &ty::Method<'tcx>)
6920 -> subst::Substs<'tcx>
6923 * Substitutes the values for the receiver's type parameters
6924 * that are found in method, leaving the method's type parameters
6928 let meth_tps: Vec<Ty> =
6929 method.generics.types.get_slice(subst::FnSpace)
6931 .map(|def| ty::mk_param_from_def(tcx, def))
6933 let meth_regions: Vec<ty::Region> =
6934 method.generics.regions.get_slice(subst::FnSpace)
6936 .map(|def| ty::ReEarlyBound(def.def_id.node, def.space,
6937 def.index, def.name))
6939 trait_ref.substs.clone().with_method(meth_tps, meth_regions)
6943 pub enum CopyImplementationError {
6944 FieldDoesNotImplementCopy(ast::Name),
6945 VariantDoesNotImplementCopy(ast::Name),
6949 pub fn can_type_implement_copy<'a,'tcx>(param_env: &ParameterEnvironment<'a, 'tcx>,
6951 self_type: Ty<'tcx>)
6952 -> Result<(),CopyImplementationError>
6954 let tcx = param_env.tcx;
6956 match self_type.sty {
6957 ty::ty_struct(struct_did, substs) => {
6958 let fields = ty::struct_fields(tcx, struct_did, substs);
6959 for field in fields.iter() {
6960 if type_moves_by_default(param_env, span, field.mt.ty) {
6961 return Err(FieldDoesNotImplementCopy(field.name))
6965 ty::ty_enum(enum_did, substs) => {
6966 let enum_variants = ty::enum_variants(tcx, enum_did);
6967 for variant in enum_variants.iter() {
6968 for variant_arg_type in variant.args.iter() {
6969 let substd_arg_type =
6970 variant_arg_type.subst(tcx, substs);
6971 if type_moves_by_default(param_env, span, substd_arg_type) {
6972 return Err(VariantDoesNotImplementCopy(variant.name))
6977 _ => return Err(TypeIsStructural),
6983 // FIXME(#20298) -- all of these types basically walk various
6984 // structures to test whether types/regions are reachable with various
6985 // properties. It should be possible to express them in terms of one
6986 // common "walker" trait or something.
6988 pub trait RegionEscape {
6989 fn has_escaping_regions(&self) -> bool {
6990 self.has_regions_escaping_depth(0)
6993 fn has_regions_escaping_depth(&self, depth: u32) -> bool;
6996 impl<'tcx> RegionEscape for Ty<'tcx> {
6997 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6998 ty::type_escapes_depth(*self, depth)
7002 impl<'tcx,T:RegionEscape> RegionEscape for VecPerParamSpace<T> {
7003 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7004 self.iter_enumerated().any(|(space, _, t)| {
7005 if space == subst::FnSpace {
7006 t.has_regions_escaping_depth(depth+1)
7008 t.has_regions_escaping_depth(depth)
7014 impl<'tcx> RegionEscape for TypeScheme<'tcx> {
7015 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7016 self.ty.has_regions_escaping_depth(depth) ||
7017 self.generics.has_regions_escaping_depth(depth)
7021 impl RegionEscape for Region {
7022 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7023 self.escapes_depth(depth)
7027 impl<'tcx> RegionEscape for Generics<'tcx> {
7028 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7029 self.predicates.has_regions_escaping_depth(depth)
7033 impl<'tcx> RegionEscape for Predicate<'tcx> {
7034 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7036 Predicate::Trait(ref data) => data.has_regions_escaping_depth(depth),
7037 Predicate::Equate(ref data) => data.has_regions_escaping_depth(depth),
7038 Predicate::RegionOutlives(ref data) => data.has_regions_escaping_depth(depth),
7039 Predicate::TypeOutlives(ref data) => data.has_regions_escaping_depth(depth),
7040 Predicate::Projection(ref data) => data.has_regions_escaping_depth(depth),
7045 impl<'tcx> RegionEscape for TraitRef<'tcx> {
7046 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7047 self.substs.types.iter().any(|t| t.has_regions_escaping_depth(depth)) ||
7048 self.substs.regions.has_regions_escaping_depth(depth)
7052 impl<'tcx> RegionEscape for subst::RegionSubsts {
7053 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7055 subst::ErasedRegions => false,
7056 subst::NonerasedRegions(ref r) => {
7057 r.iter().any(|t| t.has_regions_escaping_depth(depth))
7063 impl<'tcx,T:RegionEscape> RegionEscape for Binder<T> {
7064 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7065 self.0.has_regions_escaping_depth(depth + 1)
7069 impl<'tcx> RegionEscape for EquatePredicate<'tcx> {
7070 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7071 self.0.has_regions_escaping_depth(depth) || self.1.has_regions_escaping_depth(depth)
7075 impl<'tcx> RegionEscape for TraitPredicate<'tcx> {
7076 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7077 self.trait_ref.has_regions_escaping_depth(depth)
7081 impl<T:RegionEscape,U:RegionEscape> RegionEscape for OutlivesPredicate<T,U> {
7082 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7083 self.0.has_regions_escaping_depth(depth) || self.1.has_regions_escaping_depth(depth)
7087 impl<'tcx> RegionEscape for ProjectionPredicate<'tcx> {
7088 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7089 self.projection_ty.has_regions_escaping_depth(depth) ||
7090 self.ty.has_regions_escaping_depth(depth)
7094 impl<'tcx> RegionEscape for ProjectionTy<'tcx> {
7095 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7096 self.trait_ref.has_regions_escaping_depth(depth)
7100 impl<'tcx> Repr<'tcx> for ty::ProjectionPredicate<'tcx> {
7101 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7102 format!("ProjectionPredicate({}, {})",
7103 self.projection_ty.repr(tcx),
7108 pub trait HasProjectionTypes {
7109 fn has_projection_types(&self) -> bool;
7112 impl<'tcx,T:HasProjectionTypes> HasProjectionTypes for Vec<T> {
7113 fn has_projection_types(&self) -> bool {
7114 self.iter().any(|p| p.has_projection_types())
7118 impl<'tcx,T:HasProjectionTypes> HasProjectionTypes for VecPerParamSpace<T> {
7119 fn has_projection_types(&self) -> bool {
7120 self.iter().any(|p| p.has_projection_types())
7124 impl<'tcx> HasProjectionTypes for ClosureTy<'tcx> {
7125 fn has_projection_types(&self) -> bool {
7126 self.sig.has_projection_types()
7130 impl<'tcx> HasProjectionTypes for UnboxedClosureUpvar<'tcx> {
7131 fn has_projection_types(&self) -> bool {
7132 self.ty.has_projection_types()
7136 impl<'tcx> HasProjectionTypes for ty::GenericBounds<'tcx> {
7137 fn has_projection_types(&self) -> bool {
7138 self.predicates.has_projection_types()
7142 impl<'tcx> HasProjectionTypes for Predicate<'tcx> {
7143 fn has_projection_types(&self) -> bool {
7145 Predicate::Trait(ref data) => data.has_projection_types(),
7146 Predicate::Equate(ref data) => data.has_projection_types(),
7147 Predicate::RegionOutlives(ref data) => data.has_projection_types(),
7148 Predicate::TypeOutlives(ref data) => data.has_projection_types(),
7149 Predicate::Projection(ref data) => data.has_projection_types(),
7154 impl<'tcx> HasProjectionTypes for TraitPredicate<'tcx> {
7155 fn has_projection_types(&self) -> bool {
7156 self.trait_ref.has_projection_types()
7160 impl<'tcx> HasProjectionTypes for EquatePredicate<'tcx> {
7161 fn has_projection_types(&self) -> bool {
7162 self.0.has_projection_types() || self.1.has_projection_types()
7166 impl HasProjectionTypes for Region {
7167 fn has_projection_types(&self) -> bool {
7172 impl<T:HasProjectionTypes,U:HasProjectionTypes> HasProjectionTypes for OutlivesPredicate<T,U> {
7173 fn has_projection_types(&self) -> bool {
7174 self.0.has_projection_types() || self.1.has_projection_types()
7178 impl<'tcx> HasProjectionTypes for ProjectionPredicate<'tcx> {
7179 fn has_projection_types(&self) -> bool {
7180 self.projection_ty.has_projection_types() || self.ty.has_projection_types()
7184 impl<'tcx> HasProjectionTypes for ProjectionTy<'tcx> {
7185 fn has_projection_types(&self) -> bool {
7186 self.trait_ref.has_projection_types()
7190 impl<'tcx> HasProjectionTypes for Ty<'tcx> {
7191 fn has_projection_types(&self) -> bool {
7192 ty::type_has_projection(*self)
7196 impl<'tcx> HasProjectionTypes for TraitRef<'tcx> {
7197 fn has_projection_types(&self) -> bool {
7198 self.substs.has_projection_types()
7202 impl<'tcx> HasProjectionTypes for subst::Substs<'tcx> {
7203 fn has_projection_types(&self) -> bool {
7204 self.types.iter().any(|t| t.has_projection_types())
7208 impl<'tcx,T> HasProjectionTypes for Option<T>
7209 where T : HasProjectionTypes
7211 fn has_projection_types(&self) -> bool {
7212 self.iter().any(|t| t.has_projection_types())
7216 impl<'tcx,T> HasProjectionTypes for Rc<T>
7217 where T : HasProjectionTypes
7219 fn has_projection_types(&self) -> bool {
7220 (**self).has_projection_types()
7224 impl<'tcx,T> HasProjectionTypes for Box<T>
7225 where T : HasProjectionTypes
7227 fn has_projection_types(&self) -> bool {
7228 (**self).has_projection_types()
7232 impl<T> HasProjectionTypes for Binder<T>
7233 where T : HasProjectionTypes
7235 fn has_projection_types(&self) -> bool {
7236 self.0.has_projection_types()
7240 impl<'tcx> HasProjectionTypes for FnOutput<'tcx> {
7241 fn has_projection_types(&self) -> bool {
7243 FnConverging(t) => t.has_projection_types(),
7244 FnDiverging => false,
7249 impl<'tcx> HasProjectionTypes for FnSig<'tcx> {
7250 fn has_projection_types(&self) -> bool {
7251 self.inputs.iter().any(|t| t.has_projection_types()) ||
7252 self.output.has_projection_types()
7256 impl<'tcx> HasProjectionTypes for BareFnTy<'tcx> {
7257 fn has_projection_types(&self) -> bool {
7258 self.sig.has_projection_types()
7262 pub trait ReferencesError {
7263 fn references_error(&self) -> bool;
7266 impl<T:ReferencesError> ReferencesError for Binder<T> {
7267 fn references_error(&self) -> bool {
7268 self.0.references_error()
7272 impl<T:ReferencesError> ReferencesError for Rc<T> {
7273 fn references_error(&self) -> bool {
7274 (&**self).references_error()
7278 impl<'tcx> ReferencesError for TraitPredicate<'tcx> {
7279 fn references_error(&self) -> bool {
7280 self.trait_ref.references_error()
7284 impl<'tcx> ReferencesError for ProjectionPredicate<'tcx> {
7285 fn references_error(&self) -> bool {
7286 self.projection_ty.trait_ref.references_error() || self.ty.references_error()
7290 impl<'tcx> ReferencesError for TraitRef<'tcx> {
7291 fn references_error(&self) -> bool {
7292 self.input_types().iter().any(|t| t.references_error())
7296 impl<'tcx> ReferencesError for Ty<'tcx> {
7297 fn references_error(&self) -> bool {
7298 type_is_error(*self)
7302 impl<'tcx> ReferencesError for Predicate<'tcx> {
7303 fn references_error(&self) -> bool {
7305 Predicate::Trait(ref data) => data.references_error(),
7306 Predicate::Equate(ref data) => data.references_error(),
7307 Predicate::RegionOutlives(ref data) => data.references_error(),
7308 Predicate::TypeOutlives(ref data) => data.references_error(),
7309 Predicate::Projection(ref data) => data.references_error(),
7314 impl<A,B> ReferencesError for OutlivesPredicate<A,B>
7315 where A : ReferencesError, B : ReferencesError
7317 fn references_error(&self) -> bool {
7318 self.0.references_error() || self.1.references_error()
7322 impl<'tcx> ReferencesError for EquatePredicate<'tcx>
7324 fn references_error(&self) -> bool {
7325 self.0.references_error() || self.1.references_error()
7329 impl ReferencesError for Region
7331 fn references_error(&self) -> bool {
7336 impl<'tcx> Repr<'tcx> for ClosureTy<'tcx> {
7337 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7338 format!("ClosureTy({},{},{},{},{},{})",
7342 self.bounds.repr(tcx),
7348 impl<'tcx> Repr<'tcx> for UnboxedClosureUpvar<'tcx> {
7349 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7350 format!("UnboxedClosureUpvar({},{})",