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 AdjustReifyFnPointer(ast::DefId), // go from a fn-item type to a fn-pointer type
297 AdjustDerefRef(AutoDerefRef<'tcx>)
300 #[derive(Clone, PartialEq, Show)]
301 pub enum UnsizeKind<'tcx> {
302 // [T, ..n] -> [T], the uint field is n.
304 // An unsize coercion applied to the tail field of a struct.
305 // The uint is the index of the type parameter which is unsized.
306 UnsizeStruct(Box<UnsizeKind<'tcx>>, uint),
307 UnsizeVtable(TyTrait<'tcx>, /* the self type of the trait */ Ty<'tcx>)
310 #[derive(Clone, Show)]
311 pub struct AutoDerefRef<'tcx> {
312 pub autoderefs: uint,
313 pub autoref: Option<AutoRef<'tcx>>
316 #[derive(Clone, PartialEq, Show)]
317 pub enum AutoRef<'tcx> {
318 /// Convert from T to &T
319 /// The third field allows us to wrap other AutoRef adjustments.
320 AutoPtr(Region, ast::Mutability, Option<Box<AutoRef<'tcx>>>),
322 /// Convert [T, ..n] to [T] (or similar, depending on the kind)
323 AutoUnsize(UnsizeKind<'tcx>),
325 /// Convert Box<[T, ..n]> to Box<[T]> or something similar in a Box.
326 /// With DST and Box a library type, this should be replaced by UnsizeStruct.
327 AutoUnsizeUniq(UnsizeKind<'tcx>),
329 /// Convert from T to *T
330 /// Value to thin pointer
331 /// The second field allows us to wrap other AutoRef adjustments.
332 AutoUnsafe(ast::Mutability, Option<Box<AutoRef<'tcx>>>),
335 // Ugly little helper function. The first bool in the returned tuple is true if
336 // there is an 'unsize to trait object' adjustment at the bottom of the
337 // adjustment. If that is surrounded by an AutoPtr, then we also return the
338 // region of the AutoPtr (in the third argument). The second bool is true if the
339 // adjustment is unique.
340 fn autoref_object_region(autoref: &AutoRef) -> (bool, bool, Option<Region>) {
341 fn unsize_kind_is_object(k: &UnsizeKind) -> bool {
343 &UnsizeVtable(..) => true,
344 &UnsizeStruct(box ref k, _) => unsize_kind_is_object(k),
350 &AutoUnsize(ref k) => (unsize_kind_is_object(k), false, None),
351 &AutoUnsizeUniq(ref k) => (unsize_kind_is_object(k), true, None),
352 &AutoPtr(adj_r, _, Some(box ref autoref)) => {
353 let (b, u, r) = autoref_object_region(autoref);
354 if r.is_some() || u {
360 &AutoUnsafe(_, Some(box ref autoref)) => autoref_object_region(autoref),
361 _ => (false, false, None)
365 // If the adjustment introduces a borrowed reference to a trait object, then
366 // returns the region of the borrowed reference.
367 pub fn adjusted_object_region(adj: &AutoAdjustment) -> Option<Region> {
369 &AdjustDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
370 let (b, _, r) = autoref_object_region(autoref);
381 // Returns true if there is a trait cast at the bottom of the adjustment.
382 pub fn adjust_is_object(adj: &AutoAdjustment) -> bool {
384 &AdjustDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
385 let (b, _, _) = autoref_object_region(autoref);
392 // If possible, returns the type expected from the given adjustment. This is not
393 // possible if the adjustment depends on the type of the adjusted expression.
394 pub fn type_of_adjust<'tcx>(cx: &ctxt<'tcx>, adj: &AutoAdjustment<'tcx>) -> Option<Ty<'tcx>> {
395 fn type_of_autoref<'tcx>(cx: &ctxt<'tcx>, autoref: &AutoRef<'tcx>) -> Option<Ty<'tcx>> {
397 &AutoUnsize(ref k) => match k {
398 &UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
399 Some(mk_trait(cx, principal.clone(), bounds.clone()))
403 &AutoUnsizeUniq(ref k) => match k {
404 &UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
405 Some(mk_uniq(cx, mk_trait(cx, principal.clone(), bounds.clone())))
409 &AutoPtr(r, m, Some(box ref autoref)) => {
410 match type_of_autoref(cx, autoref) {
411 Some(ty) => Some(mk_rptr(cx, cx.mk_region(r), mt {mutbl: m, ty: ty})),
415 &AutoUnsafe(m, Some(box ref autoref)) => {
416 match type_of_autoref(cx, autoref) {
417 Some(ty) => Some(mk_ptr(cx, mt {mutbl: m, ty: ty})),
426 &AdjustDerefRef(AutoDerefRef{autoref: Some(ref autoref), ..}) => {
427 type_of_autoref(cx, autoref)
433 #[derive(Clone, Copy, RustcEncodable, RustcDecodable, PartialEq, PartialOrd, Show)]
434 pub struct param_index {
435 pub space: subst::ParamSpace,
439 #[derive(Clone, Show)]
440 pub enum MethodOrigin<'tcx> {
441 // fully statically resolved method
442 MethodStatic(ast::DefId),
444 // fully statically resolved unboxed closure invocation
445 MethodStaticUnboxedClosure(ast::DefId),
447 // method invoked on a type parameter with a bounded trait
448 MethodTypeParam(MethodParam<'tcx>),
450 // method invoked on a trait instance
451 MethodTraitObject(MethodObject<'tcx>),
455 // details for a method invoked with a receiver whose type is a type parameter
456 // with a bounded trait.
457 #[derive(Clone, Show)]
458 pub struct MethodParam<'tcx> {
459 // the precise trait reference that occurs as a bound -- this may
460 // be a supertrait of what the user actually typed. Note that it
461 // never contains bound regions; those regions should have been
462 // instantiated with fresh variables at this point.
463 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
465 // index of uint in the list of methods for the trait
466 pub method_num: uint,
469 // details for a method invoked with a receiver whose type is an object
470 #[derive(Clone, Show)]
471 pub struct MethodObject<'tcx> {
472 // the (super)trait containing the method to be invoked
473 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
475 // the actual base trait id of the object
476 pub object_trait_id: ast::DefId,
478 // index of the method to be invoked amongst the trait's methods
479 pub method_num: uint,
481 // index into the actual runtime vtable.
482 // the vtable is formed by concatenating together the method lists of
483 // the base object trait and all supertraits; this is the index into
485 pub real_index: uint,
489 pub struct MethodCallee<'tcx> {
490 pub origin: MethodOrigin<'tcx>,
492 pub substs: subst::Substs<'tcx>
495 /// With method calls, we store some extra information in
496 /// side tables (i.e method_map). We use
497 /// MethodCall as a key to index into these tables instead of
498 /// just directly using the expression's NodeId. The reason
499 /// for this being that we may apply adjustments (coercions)
500 /// with the resulting expression also needing to use the
501 /// side tables. The problem with this is that we don't
502 /// assign a separate NodeId to this new expression
503 /// and so it would clash with the base expression if both
504 /// needed to add to the side tables. Thus to disambiguate
505 /// we also keep track of whether there's an adjustment in
507 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
508 pub struct MethodCall {
509 pub expr_id: ast::NodeId,
510 pub adjustment: ExprAdjustment
513 #[derive(Clone, PartialEq, Eq, Hash, Show, RustcEncodable, RustcDecodable, Copy)]
514 pub enum ExprAdjustment {
521 pub fn expr(id: ast::NodeId) -> MethodCall {
524 adjustment: NoAdjustment
528 pub fn autoobject(id: ast::NodeId) -> MethodCall {
531 adjustment: AutoObject
535 pub fn autoderef(expr_id: ast::NodeId, autoderef: uint) -> MethodCall {
538 adjustment: AutoDeref(1 + autoderef)
543 // maps from an expression id that corresponds to a method call to the details
544 // of the method to be invoked
545 pub type MethodMap<'tcx> = RefCell<FnvHashMap<MethodCall, MethodCallee<'tcx>>>;
547 pub type vtable_param_res<'tcx> = Vec<vtable_origin<'tcx>>;
549 // Resolutions for bounds of all parameters, left to right, for a given path.
550 pub type vtable_res<'tcx> = VecPerParamSpace<vtable_param_res<'tcx>>;
553 pub enum vtable_origin<'tcx> {
555 Statically known vtable. def_id gives the impl item
556 from whence comes the vtable, and tys are the type substs.
557 vtable_res is the vtable itself.
559 vtable_static(ast::DefId, subst::Substs<'tcx>, vtable_res<'tcx>),
562 Dynamic vtable, comes from a parameter that has a bound on it:
563 fn foo<T:quux,baz,bar>(a: T) -- a's vtable would have a
566 The first argument is the param index (identifying T in the example),
567 and the second is the bound number (identifying baz)
569 vtable_param(param_index, uint),
572 Vtable automatically generated for an unboxed closure. The def ID is the
573 ID of the closure expression.
575 vtable_unboxed_closure(ast::DefId),
578 Asked to determine the vtable for ty_err. This is the value used
579 for the vtables of `Self` in a virtual call like `foo.bar()`
580 where `foo` is of object type. The same value is also used when
587 // For every explicit cast into an object type, maps from the cast
588 // expr to the associated trait ref.
589 pub type ObjectCastMap<'tcx> = RefCell<NodeMap<ty::PolyTraitRef<'tcx>>>;
591 /// A restriction that certain types must be the same size. The use of
592 /// `transmute` gives rise to these restrictions. These generally
593 /// cannot be checked until trans; therefore, each call to `transmute`
594 /// will push one or more such restriction into the
595 /// `transmute_restrictions` vector during `intrinsicck`. They are
596 /// then checked during `trans` by the fn `check_intrinsics`.
598 pub struct TransmuteRestriction<'tcx> {
599 /// The span whence the restriction comes.
602 /// The type being transmuted from.
603 pub original_from: Ty<'tcx>,
605 /// The type being transmuted to.
606 pub original_to: Ty<'tcx>,
608 /// The type being transmuted from, with all type parameters
609 /// substituted for an arbitrary representative. Not to be shown
611 pub substituted_from: Ty<'tcx>,
613 /// The type being transmuted to, with all type parameters
614 /// substituted for an arbitrary representative. Not to be shown
616 pub substituted_to: Ty<'tcx>,
618 /// NodeId of the transmute intrinsic.
623 pub struct CtxtArenas<'tcx> {
624 type_: TypedArena<TyS<'tcx>>,
625 substs: TypedArena<Substs<'tcx>>,
626 bare_fn: TypedArena<BareFnTy<'tcx>>,
627 region: TypedArena<Region>,
630 impl<'tcx> CtxtArenas<'tcx> {
631 pub fn new() -> CtxtArenas<'tcx> {
633 type_: TypedArena::new(),
634 substs: TypedArena::new(),
635 bare_fn: TypedArena::new(),
636 region: TypedArena::new(),
641 pub struct CommonTypes<'tcx> {
659 /// The data structure to keep track of all the information that typechecker
660 /// generates so that so that it can be reused and doesn't have to be redone
662 pub struct ctxt<'tcx> {
663 /// The arenas that types etc are allocated from.
664 arenas: &'tcx CtxtArenas<'tcx>,
666 /// Specifically use a speedy hash algorithm for this hash map, it's used
668 // FIXME(eddyb) use a FnvHashSet<InternedTy<'tcx>> when equivalent keys can
669 // queried from a HashSet.
670 interner: RefCell<FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>>,
672 // FIXME as above, use a hashset if equivalent elements can be queried.
673 substs_interner: RefCell<FnvHashMap<&'tcx Substs<'tcx>, &'tcx Substs<'tcx>>>,
674 bare_fn_interner: RefCell<FnvHashMap<&'tcx BareFnTy<'tcx>, &'tcx BareFnTy<'tcx>>>,
675 region_interner: RefCell<FnvHashMap<&'tcx Region, &'tcx Region>>,
677 /// Common types, pre-interned for your convenience.
678 pub types: CommonTypes<'tcx>,
683 pub named_region_map: resolve_lifetime::NamedRegionMap,
685 pub region_maps: middle::region::RegionMaps,
687 /// Stores the types for various nodes in the AST. Note that this table
688 /// is not guaranteed to be populated until after typeck. See
689 /// typeck::check::fn_ctxt for details.
690 pub node_types: RefCell<NodeMap<Ty<'tcx>>>,
692 /// Stores the type parameters which were substituted to obtain the type
693 /// of this node. This only applies to nodes that refer to entities
694 /// parameterized by type parameters, such as generic fns, types, or
696 pub item_substs: RefCell<NodeMap<ItemSubsts<'tcx>>>,
698 /// Maps from a trait item to the trait item "descriptor"
699 pub impl_or_trait_items: RefCell<DefIdMap<ImplOrTraitItem<'tcx>>>,
701 /// Maps from a trait def-id to a list of the def-ids of its trait items
702 pub trait_item_def_ids: RefCell<DefIdMap<Rc<Vec<ImplOrTraitItemId>>>>,
704 /// A cache for the trait_items() routine
705 pub trait_items_cache: RefCell<DefIdMap<Rc<Vec<ImplOrTraitItem<'tcx>>>>>,
707 pub impl_trait_cache: RefCell<DefIdMap<Option<Rc<ty::TraitRef<'tcx>>>>>,
709 pub trait_refs: RefCell<NodeMap<Rc<TraitRef<'tcx>>>>,
710 pub trait_defs: RefCell<DefIdMap<Rc<TraitDef<'tcx>>>>,
712 /// Maps from node-id of a trait object cast (like `foo as
713 /// Box<Trait>`) to the trait reference.
714 pub object_cast_map: ObjectCastMap<'tcx>,
716 pub map: ast_map::Map<'tcx>,
717 pub intrinsic_defs: RefCell<DefIdMap<Ty<'tcx>>>,
718 pub freevars: RefCell<FreevarMap>,
719 pub tcache: RefCell<DefIdMap<TypeScheme<'tcx>>>,
720 pub rcache: RefCell<FnvHashMap<creader_cache_key, Ty<'tcx>>>,
721 pub short_names_cache: RefCell<FnvHashMap<Ty<'tcx>, String>>,
722 pub tc_cache: RefCell<FnvHashMap<Ty<'tcx>, TypeContents>>,
723 pub ast_ty_to_ty_cache: RefCell<NodeMap<ast_ty_to_ty_cache_entry<'tcx>>>,
724 pub enum_var_cache: RefCell<DefIdMap<Rc<Vec<Rc<VariantInfo<'tcx>>>>>>,
725 pub ty_param_defs: RefCell<NodeMap<TypeParameterDef<'tcx>>>,
726 pub adjustments: RefCell<NodeMap<AutoAdjustment<'tcx>>>,
727 pub normalized_cache: RefCell<FnvHashMap<Ty<'tcx>, Ty<'tcx>>>,
728 pub lang_items: middle::lang_items::LanguageItems,
729 /// A mapping of fake provided method def_ids to the default implementation
730 pub provided_method_sources: RefCell<DefIdMap<ast::DefId>>,
731 pub struct_fields: RefCell<DefIdMap<Rc<Vec<field_ty>>>>,
733 /// Maps from def-id of a type or region parameter to its
734 /// (inferred) variance.
735 pub item_variance_map: RefCell<DefIdMap<Rc<ItemVariances>>>,
737 /// True if the variance has been computed yet; false otherwise.
738 pub variance_computed: Cell<bool>,
740 /// A mapping from the def ID of an enum or struct type to the def ID
741 /// of the method that implements its destructor. If the type is not
742 /// present in this map, it does not have a destructor. This map is
743 /// populated during the coherence phase of typechecking.
744 pub destructor_for_type: RefCell<DefIdMap<ast::DefId>>,
746 /// A method will be in this list if and only if it is a destructor.
747 pub destructors: RefCell<DefIdSet>,
749 /// Maps a trait onto a list of impls of that trait.
750 pub trait_impls: RefCell<DefIdMap<Rc<RefCell<Vec<ast::DefId>>>>>,
752 /// Maps a DefId of a type to a list of its inherent impls.
753 /// Contains implementations of methods that are inherent to a type.
754 /// Methods in these implementations don't need to be exported.
755 pub inherent_impls: RefCell<DefIdMap<Rc<Vec<ast::DefId>>>>,
757 /// Maps a DefId of an impl to a list of its items.
758 /// Note that this contains all of the impls that we know about,
759 /// including ones in other crates. It's not clear that this is the best
761 pub impl_items: RefCell<DefIdMap<Vec<ImplOrTraitItemId>>>,
763 /// Set of used unsafe nodes (functions or blocks). Unsafe nodes not
764 /// present in this set can be warned about.
765 pub used_unsafe: RefCell<NodeSet>,
767 /// Set of nodes which mark locals as mutable which end up getting used at
768 /// some point. Local variable definitions not in this set can be warned
770 pub used_mut_nodes: RefCell<NodeSet>,
772 /// The set of external nominal types whose implementations have been read.
773 /// This is used for lazy resolution of methods.
774 pub populated_external_types: RefCell<DefIdSet>,
776 /// The set of external traits whose implementations have been read. This
777 /// is used for lazy resolution of traits.
778 pub populated_external_traits: RefCell<DefIdSet>,
781 pub upvar_borrow_map: RefCell<UpvarBorrowMap>,
783 /// These two caches are used by const_eval when decoding external statics
784 /// and variants that are found.
785 pub extern_const_statics: RefCell<DefIdMap<ast::NodeId>>,
786 pub extern_const_variants: RefCell<DefIdMap<ast::NodeId>>,
788 pub method_map: MethodMap<'tcx>,
790 pub dependency_formats: RefCell<dependency_format::Dependencies>,
792 /// Records the type of each unboxed closure. The def ID is the ID of the
793 /// expression defining the unboxed closure.
794 pub unboxed_closures: RefCell<DefIdMap<UnboxedClosure<'tcx>>>,
796 pub node_lint_levels: RefCell<FnvHashMap<(ast::NodeId, lint::LintId),
799 /// The types that must be asserted to be the same size for `transmute`
800 /// to be valid. We gather up these restrictions in the intrinsicck pass
801 /// and check them in trans.
802 pub transmute_restrictions: RefCell<Vec<TransmuteRestriction<'tcx>>>,
804 /// Maps any item's def-id to its stability index.
805 pub stability: RefCell<stability::Index>,
807 /// Maps closures to their capture clauses.
808 pub capture_modes: RefCell<CaptureModeMap>,
810 /// Maps def IDs to true if and only if they're associated types.
811 pub associated_types: RefCell<DefIdMap<bool>>,
813 /// Caches the results of trait selection. This cache is used
814 /// for things that do not have to do with the parameters in scope.
815 pub selection_cache: traits::SelectionCache<'tcx>,
817 /// Caches the representation hints for struct definitions.
818 pub repr_hint_cache: RefCell<DefIdMap<Rc<Vec<attr::ReprAttr>>>>,
820 /// Caches whether types are known to impl Copy. Note that type
821 /// parameters are never placed into this cache, because their
822 /// results are dependent on the parameter environment.
823 pub type_impls_copy_cache: RefCell<HashMap<Ty<'tcx>,bool>>,
825 /// Caches whether types are known to impl Sized. Note that type
826 /// parameters are never placed into this cache, because their
827 /// results are dependent on the parameter environment.
828 pub type_impls_sized_cache: RefCell<HashMap<Ty<'tcx>,bool>>,
830 /// Caches whether traits are object safe
831 pub object_safety_cache: RefCell<DefIdMap<bool>>,
834 // Flags that we track on types. These flags are propagated upwards
835 // through the type during type construction, so that we can quickly
836 // check whether the type has various kinds of types in it without
837 // recursing over the type itself.
839 flags TypeFlags: u32 {
840 const NO_TYPE_FLAGS = 0b0,
841 const HAS_PARAMS = 0b1,
842 const HAS_SELF = 0b10,
843 const HAS_TY_INFER = 0b100,
844 const HAS_RE_INFER = 0b1000,
845 const HAS_RE_LATE_BOUND = 0b10000,
846 const HAS_REGIONS = 0b100000,
847 const HAS_TY_ERR = 0b1000000,
848 const HAS_PROJECTION = 0b10000000,
849 const NEEDS_SUBST = HAS_PARAMS.bits | HAS_SELF.bits | HAS_REGIONS.bits,
853 macro_rules! sty_debug_print {
854 ($ctxt: expr, $($variant: ident),*) => {{
855 // curious inner module to allow variant names to be used as
867 pub fn go(tcx: &ty::ctxt) {
868 let mut total = DebugStat {
870 region_infer: 0, ty_infer: 0, both_infer: 0,
872 $(let mut $variant = total;)*
875 for (_, t) in tcx.interner.borrow().iter() {
876 let variant = match t.sty {
877 ty::ty_bool | ty::ty_char | ty::ty_int(..) | ty::ty_uint(..) |
878 ty::ty_float(..) | ty::ty_str => continue,
879 ty::ty_err => /* unimportant */ continue,
880 $(ty::$variant(..) => &mut $variant,)*
882 let region = t.flags.intersects(ty::HAS_RE_INFER);
883 let ty = t.flags.intersects(ty::HAS_TY_INFER);
887 if region { total.region_infer += 1; variant.region_infer += 1 }
888 if ty { total.ty_infer += 1; variant.ty_infer += 1 }
889 if region && ty { total.both_infer += 1; variant.both_infer += 1 }
891 println!("Ty interner total ty region both");
892 $(println!(" {:18}: {uses:6} {usespc:4.1}%, \
893 {ty:4.1}% {region:5.1}% {both:4.1}%",
894 stringify!($variant),
895 uses = $variant.total,
896 usespc = $variant.total as f64 * 100.0 / total.total as f64,
897 ty = $variant.ty_infer as f64 * 100.0 / total.total as f64,
898 region = $variant.region_infer as f64 * 100.0 / total.total as f64,
899 both = $variant.both_infer as f64 * 100.0 / total.total as f64);
901 println!(" total {uses:6} \
902 {ty:4.1}% {region:5.1}% {both:4.1}%",
904 ty = total.ty_infer as f64 * 100.0 / total.total as f64,
905 region = total.region_infer as f64 * 100.0 / total.total as f64,
906 both = total.both_infer as f64 * 100.0 / total.total as f64)
914 impl<'tcx> ctxt<'tcx> {
915 pub fn print_debug_stats(&self) {
918 ty_enum, ty_uniq, ty_vec, ty_ptr, ty_rptr, ty_bare_fn, ty_trait,
919 ty_struct, ty_unboxed_closure, ty_tup, ty_param, ty_open, ty_infer, ty_projection);
921 println!("Substs interner: #{}", self.substs_interner.borrow().len());
922 println!("BareFnTy interner: #{}", self.bare_fn_interner.borrow().len());
923 println!("Region interner: #{}", self.region_interner.borrow().len());
928 pub struct TyS<'tcx> {
930 pub flags: TypeFlags,
932 // the maximal depth of any bound regions appearing in this type.
936 impl fmt::Show for TypeFlags {
937 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
938 write!(f, "{}", self.bits)
942 impl<'tcx> PartialEq for TyS<'tcx> {
943 fn eq(&self, other: &TyS<'tcx>) -> bool {
944 (self as *const _) == (other as *const _)
947 impl<'tcx> Eq for TyS<'tcx> {}
949 impl<'tcx, S: Writer> Hash<S> for TyS<'tcx> {
950 fn hash(&self, s: &mut S) {
951 (self as *const _).hash(s)
955 pub type Ty<'tcx> = &'tcx TyS<'tcx>;
957 /// An entry in the type interner.
958 pub struct InternedTy<'tcx> {
962 // NB: An InternedTy compares and hashes as a sty.
963 impl<'tcx> PartialEq for InternedTy<'tcx> {
964 fn eq(&self, other: &InternedTy<'tcx>) -> bool {
965 self.ty.sty == other.ty.sty
969 impl<'tcx> Eq for InternedTy<'tcx> {}
971 impl<'tcx, S: Writer> Hash<S> for InternedTy<'tcx> {
972 fn hash(&self, s: &mut S) {
977 impl<'tcx> BorrowFrom<InternedTy<'tcx>> for sty<'tcx> {
978 fn borrow_from<'a>(ty: &'a InternedTy<'tcx>) -> &'a sty<'tcx> {
983 pub fn type_has_params(ty: Ty) -> bool {
984 ty.flags.intersects(HAS_PARAMS)
986 pub fn type_has_self(ty: Ty) -> bool {
987 ty.flags.intersects(HAS_SELF)
989 pub fn type_has_ty_infer(ty: Ty) -> bool {
990 ty.flags.intersects(HAS_TY_INFER)
992 pub fn type_needs_infer(ty: Ty) -> bool {
993 ty.flags.intersects(HAS_TY_INFER | HAS_RE_INFER)
995 pub fn type_has_projection(ty: Ty) -> bool {
996 ty.flags.intersects(HAS_PROJECTION)
999 pub fn type_has_late_bound_regions(ty: Ty) -> bool {
1000 ty.flags.intersects(HAS_RE_LATE_BOUND)
1003 /// An "escaping region" is a bound region whose binder is not part of `t`.
1005 /// So, for example, consider a type like the following, which has two binders:
1007 /// for<'a> fn(x: for<'b> fn(&'a int, &'b int))
1008 /// ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ outer scope
1009 /// ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ inner scope
1011 /// This type has *bound regions* (`'a`, `'b`), but it does not have escaping regions, because the
1012 /// binders of both `'a` and `'b` are part of the type itself. However, if we consider the *inner
1013 /// fn type*, that type has an escaping region: `'a`.
1015 /// Note that what I'm calling an "escaping region" is often just called a "free region". However,
1016 /// we already use the term "free region". It refers to the regions that we use to represent bound
1017 /// regions on a fn definition while we are typechecking its body.
1019 /// To clarify, conceptually there is no particular difference between an "escaping" region and a
1020 /// "free" region. However, there is a big difference in practice. Basically, when "entering" a
1021 /// binding level, one is generally required to do some sort of processing to a bound region, such
1022 /// as replacing it with a fresh/skolemized region, or making an entry in the environment to
1023 /// represent the scope to which it is attached, etc. An escaping region represents a bound region
1024 /// for which this processing has not yet been done.
1025 pub fn type_has_escaping_regions(ty: Ty) -> bool {
1026 type_escapes_depth(ty, 0)
1029 pub fn type_escapes_depth(ty: Ty, depth: u32) -> bool {
1030 ty.region_depth > depth
1033 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1034 pub struct BareFnTy<'tcx> {
1035 pub unsafety: ast::Unsafety,
1037 pub sig: PolyFnSig<'tcx>,
1040 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1041 pub struct ClosureTy<'tcx> {
1042 pub unsafety: ast::Unsafety,
1043 pub onceness: ast::Onceness,
1044 pub store: TraitStore,
1045 pub bounds: ExistentialBounds<'tcx>,
1046 pub sig: PolyFnSig<'tcx>,
1050 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1051 pub enum FnOutput<'tcx> {
1052 FnConverging(Ty<'tcx>),
1056 impl<'tcx> FnOutput<'tcx> {
1057 pub fn unwrap(self) -> Ty<'tcx> {
1059 ty::FnConverging(t) => t,
1060 ty::FnDiverging => unreachable!()
1065 /// Signature of a function type, which I have arbitrarily
1066 /// decided to use to refer to the input/output types.
1068 /// - `inputs` is the list of arguments and their modes.
1069 /// - `output` is the return type.
1070 /// - `variadic` indicates whether this is a variadic function. (only true for foreign fns)
1071 #[derive(Clone, PartialEq, Eq, Hash)]
1072 pub struct FnSig<'tcx> {
1073 pub inputs: Vec<Ty<'tcx>>,
1074 pub output: FnOutput<'tcx>,
1078 pub type PolyFnSig<'tcx> = Binder<FnSig<'tcx>>;
1080 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
1081 pub struct ParamTy {
1082 pub space: subst::ParamSpace,
1084 pub name: ast::Name,
1087 /// A [De Bruijn index][dbi] is a standard means of representing
1088 /// regions (and perhaps later types) in a higher-ranked setting. In
1089 /// particular, imagine a type like this:
1091 /// for<'a> fn(for<'b> fn(&'b int, &'a int), &'a char)
1094 /// | +------------+ 1 | |
1096 /// +--------------------------------+ 2 |
1098 /// +------------------------------------------+ 1
1100 /// In this type, there are two binders (the outer fn and the inner
1101 /// fn). We need to be able to determine, for any given region, which
1102 /// fn type it is bound by, the inner or the outer one. There are
1103 /// various ways you can do this, but a De Bruijn index is one of the
1104 /// more convenient and has some nice properties. The basic idea is to
1105 /// count the number of binders, inside out. Some examples should help
1106 /// clarify what I mean.
1108 /// Let's start with the reference type `&'b int` that is the first
1109 /// argument to the inner function. This region `'b` is assigned a De
1110 /// Bruijn index of 1, meaning "the innermost binder" (in this case, a
1111 /// fn). The region `'a` that appears in the second argument type (`&'a
1112 /// int`) would then be assigned a De Bruijn index of 2, meaning "the
1113 /// second-innermost binder". (These indices are written on the arrays
1114 /// in the diagram).
1116 /// What is interesting is that De Bruijn index attached to a particular
1117 /// variable will vary depending on where it appears. For example,
1118 /// the final type `&'a char` also refers to the region `'a` declared on
1119 /// the outermost fn. But this time, this reference is not nested within
1120 /// any other binders (i.e., it is not an argument to the inner fn, but
1121 /// rather the outer one). Therefore, in this case, it is assigned a
1122 /// De Bruijn index of 1, because the innermost binder in that location
1123 /// is the outer fn.
1125 /// [dbi]: http://en.wikipedia.org/wiki/De_Bruijn_index
1126 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Show, Copy)]
1127 pub struct DebruijnIndex {
1128 // We maintain the invariant that this is never 0. So 1 indicates
1129 // the innermost binder. To ensure this, create with `DebruijnIndex::new`.
1133 /// Representation of regions:
1134 #[derive(Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, Show, Copy)]
1136 // Region bound in a type or fn declaration which will be
1137 // substituted 'early' -- that is, at the same time when type
1138 // parameters are substituted.
1139 ReEarlyBound(/* param id */ ast::NodeId,
1144 // Region bound in a function scope, which will be substituted when the
1145 // function is called.
1146 ReLateBound(DebruijnIndex, BoundRegion),
1148 /// When checking a function body, the types of all arguments and so forth
1149 /// that refer to bound region parameters are modified to refer to free
1150 /// region parameters.
1153 /// A concrete region naming some expression within the current function.
1154 ReScope(region::CodeExtent),
1156 /// Static data that has an "infinite" lifetime. Top in the region lattice.
1159 /// A region variable. Should not exist after typeck.
1160 ReInfer(InferRegion),
1162 /// Empty lifetime is for data that is never accessed.
1163 /// Bottom in the region lattice. We treat ReEmpty somewhat
1164 /// specially; at least right now, we do not generate instances of
1165 /// it during the GLB computations, but rather
1166 /// generate an error instead. This is to improve error messages.
1167 /// The only way to get an instance of ReEmpty is to have a region
1168 /// variable with no constraints.
1172 /// Upvars do not get their own node-id. Instead, we use the pair of
1173 /// the original var id (that is, the root variable that is referenced
1174 /// by the upvar) and the id of the closure expression.
1175 #[derive(Clone, Copy, PartialEq, Eq, Hash, Show)]
1176 pub struct UpvarId {
1177 pub var_id: ast::NodeId,
1178 pub closure_expr_id: ast::NodeId,
1181 #[derive(Clone, PartialEq, Eq, Hash, Show, RustcEncodable, RustcDecodable, Copy)]
1182 pub enum BorrowKind {
1183 /// Data must be immutable and is aliasable.
1186 /// Data must be immutable but not aliasable. This kind of borrow
1187 /// cannot currently be expressed by the user and is used only in
1188 /// implicit closure bindings. It is needed when you the closure
1189 /// is borrowing or mutating a mutable referent, e.g.:
1191 /// let x: &mut int = ...;
1192 /// let y = || *x += 5;
1194 /// If we were to try to translate this closure into a more explicit
1195 /// form, we'd encounter an error with the code as written:
1197 /// struct Env { x: & &mut int }
1198 /// let x: &mut int = ...;
1199 /// let y = (&mut Env { &x }, fn_ptr); // Closure is pair of env and fn
1200 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
1202 /// This is then illegal because you cannot mutate a `&mut` found
1203 /// in an aliasable location. To solve, you'd have to translate with
1204 /// an `&mut` borrow:
1206 /// struct Env { x: & &mut int }
1207 /// let x: &mut int = ...;
1208 /// let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x
1209 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
1211 /// Now the assignment to `**env.x` is legal, but creating a
1212 /// mutable pointer to `x` is not because `x` is not mutable. We
1213 /// could fix this by declaring `x` as `let mut x`. This is ok in
1214 /// user code, if awkward, but extra weird for closures, since the
1215 /// borrow is hidden.
1217 /// So we introduce a "unique imm" borrow -- the referent is
1218 /// immutable, but not aliasable. This solves the problem. For
1219 /// simplicity, we don't give users the way to express this
1220 /// borrow, it's just used when translating closures.
1223 /// Data is mutable and not aliasable.
1227 /// Information describing the borrowing of an upvar. This is computed
1228 /// during `typeck`, specifically by `regionck`. The general idea is
1229 /// that the compiler analyses treat closures like:
1231 /// let closure: &'e fn() = || {
1232 /// x = 1; // upvar x is assigned to
1233 /// use(y); // upvar y is read
1234 /// foo(&z); // upvar z is borrowed immutably
1237 /// as if they were "desugared" to something loosely like:
1239 /// struct Vars<'x,'y,'z> { x: &'x mut int,
1240 /// y: &'y const int,
1242 /// let closure: &'e fn() = {
1243 /// fn f(env: &Vars) {
1248 /// let env: &'e mut Vars<'x,'y,'z> = &mut Vars { x: &'x mut x,
1254 /// This is basically what happens at runtime. The closure is basically
1255 /// an existentially quantified version of the `(env, f)` pair.
1257 /// This data structure indicates the region and mutability of a single
1258 /// one of the `x...z` borrows.
1260 /// It may not be obvious why each borrowed variable gets its own
1261 /// lifetime (in the desugared version of the example, these are indicated
1262 /// by the lifetime parameters `'x`, `'y`, and `'z` in the `Vars` definition).
1263 /// Each such lifetime must encompass the lifetime `'e` of the closure itself,
1264 /// but need not be identical to it. The reason that this makes sense:
1266 /// - Callers are only permitted to invoke the closure, and hence to
1267 /// use the pointers, within the lifetime `'e`, so clearly `'e` must
1268 /// be a sublifetime of `'x...'z`.
1269 /// - The closure creator knows which upvars were borrowed by the closure
1270 /// and thus `x...z` will be reserved for `'x...'z` respectively.
1271 /// - Through mutation, the borrowed upvars can actually escape
1272 /// the closure, so sometimes it is necessary for them to be larger
1273 /// than the closure lifetime itself.
1274 #[derive(PartialEq, Clone, RustcEncodable, RustcDecodable, Show, Copy)]
1275 pub struct UpvarBorrow {
1276 pub kind: BorrowKind,
1277 pub region: ty::Region,
1280 pub type UpvarBorrowMap = FnvHashMap<UpvarId, UpvarBorrow>;
1283 pub fn is_bound(&self) -> bool {
1285 ty::ReEarlyBound(..) => true,
1286 ty::ReLateBound(..) => true,
1291 pub fn escapes_depth(&self, depth: u32) -> bool {
1293 ty::ReLateBound(debruijn, _) => debruijn.depth > depth,
1299 #[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
1300 RustcEncodable, RustcDecodable, Show, Copy)]
1301 /// A "free" region `fr` can be interpreted as "some region
1302 /// at least as big as the scope `fr.scope`".
1303 pub struct FreeRegion {
1304 pub scope: region::CodeExtent,
1305 pub bound_region: BoundRegion
1308 #[derive(Clone, PartialEq, PartialOrd, Eq, Ord, Hash,
1309 RustcEncodable, RustcDecodable, Show, Copy)]
1310 pub enum BoundRegion {
1311 /// An anonymous region parameter for a given fn (&T)
1314 /// Named region parameters for functions (a in &'a T)
1316 /// The def-id is needed to distinguish free regions in
1317 /// the event of shadowing.
1318 BrNamed(ast::DefId, ast::Name),
1320 /// Fresh bound identifiers created during GLB computations.
1323 // Anonymous region for the implicit env pointer parameter
1328 // NB: If you change this, you'll probably want to change the corresponding
1329 // AST structure in libsyntax/ast.rs as well.
1330 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1331 pub enum sty<'tcx> {
1335 ty_uint(ast::UintTy),
1336 ty_float(ast::FloatTy),
1337 /// Substs here, possibly against intuition, *may* contain `ty_param`s.
1338 /// That is, even after substitution it is possible that there are type
1339 /// variables. This happens when the `ty_enum` corresponds to an enum
1340 /// definition and not a concrete use of it. To get the correct `ty_enum`
1341 /// from the tcx, use the `NodeId` from the `ast::Ty` and look it up in
1342 /// the `ast_ty_to_ty_cache`. This is probably true for `ty_struct` as
1344 ty_enum(DefId, &'tcx Substs<'tcx>),
1347 ty_vec(Ty<'tcx>, Option<uint>), // Second field is length.
1349 ty_rptr(&'tcx Region, mt<'tcx>),
1351 // If the def-id is Some(_), then this is the type of a specific
1352 // fn item. Otherwise, if None(_), it a fn pointer type.
1353 ty_bare_fn(Option<DefId>, &'tcx BareFnTy<'tcx>),
1355 ty_trait(Box<TyTrait<'tcx>>),
1356 ty_struct(DefId, &'tcx Substs<'tcx>),
1358 ty_unboxed_closure(DefId, &'tcx Region, &'tcx Substs<'tcx>),
1360 ty_tup(Vec<Ty<'tcx>>),
1362 ty_projection(ProjectionTy<'tcx>),
1363 ty_param(ParamTy), // type parameter
1365 ty_open(Ty<'tcx>), // A deref'ed fat pointer, i.e., a dynamically sized value
1366 // and its size. Only ever used in trans. It is not necessary
1367 // earlier since we don't need to distinguish a DST with its
1368 // size (e.g., in a deref) vs a DST with the size elsewhere (
1369 // e.g., in a field).
1371 ty_infer(InferTy), // something used only during inference/typeck
1372 ty_err, // Also only used during inference/typeck, to represent
1373 // the type of an erroneous expression (helps cut down
1374 // on non-useful type error messages)
1377 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1378 pub struct TyTrait<'tcx> {
1379 pub principal: ty::PolyTraitRef<'tcx>,
1380 pub bounds: ExistentialBounds<'tcx>,
1383 impl<'tcx> TyTrait<'tcx> {
1384 pub fn principal_def_id(&self) -> ast::DefId {
1385 self.principal.0.def_id
1388 /// Object types don't have a self-type specified. Therefore, when
1389 /// we convert the principal trait-ref into a normal trait-ref,
1390 /// you must give *some* self-type. A common choice is `mk_err()`
1391 /// or some skolemized type.
1392 pub fn principal_trait_ref_with_self_ty(&self,
1395 -> ty::PolyTraitRef<'tcx>
1397 // otherwise the escaping regions would be captured by the binder
1398 assert!(!self_ty.has_escaping_regions());
1400 ty::Binder(Rc::new(ty::TraitRef {
1401 def_id: self.principal.0.def_id,
1402 substs: tcx.mk_substs(self.principal.0.substs.with_self_ty(self_ty)),
1406 pub fn projection_bounds_with_self_ty(&self,
1409 -> Vec<ty::PolyProjectionPredicate<'tcx>>
1411 // otherwise the escaping regions would be captured by the binders
1412 assert!(!self_ty.has_escaping_regions());
1414 self.bounds.projection_bounds.iter()
1415 .map(|in_poly_projection_predicate| {
1416 let in_projection_ty = &in_poly_projection_predicate.0.projection_ty;
1417 let substs = tcx.mk_substs(in_projection_ty.trait_ref.substs.with_self_ty(self_ty));
1419 Rc::new(ty::TraitRef::new(in_projection_ty.trait_ref.def_id,
1421 let projection_ty = ty::ProjectionTy {
1422 trait_ref: trait_ref,
1423 item_name: in_projection_ty.item_name
1425 ty::Binder(ty::ProjectionPredicate {
1426 projection_ty: projection_ty,
1427 ty: in_poly_projection_predicate.0.ty
1434 /// A complete reference to a trait. These take numerous guises in syntax,
1435 /// but perhaps the most recognizable form is in a where clause:
1439 /// This would be represented by a trait-reference where the def-id is the
1440 /// def-id for the trait `Foo` and the substs defines `T` as parameter 0 in the
1441 /// `SelfSpace` and `U` as parameter 0 in the `TypeSpace`.
1443 /// Trait references also appear in object types like `Foo<U>`, but in
1444 /// that case the `Self` parameter is absent from the substitutions.
1446 /// Note that a `TraitRef` introduces a level of region binding, to
1447 /// account for higher-ranked trait bounds like `T : for<'a> Foo<&'a
1448 /// U>` or higher-ranked object types.
1449 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1450 pub struct TraitRef<'tcx> {
1452 pub substs: &'tcx Substs<'tcx>,
1455 pub type PolyTraitRef<'tcx> = Binder<Rc<TraitRef<'tcx>>>;
1457 impl<'tcx> PolyTraitRef<'tcx> {
1458 pub fn self_ty(&self) -> Ty<'tcx> {
1462 pub fn def_id(&self) -> ast::DefId {
1466 pub fn substs(&self) -> &'tcx Substs<'tcx> {
1470 pub fn input_types(&self) -> &[Ty<'tcx>] {
1471 self.0.input_types()
1474 pub fn to_poly_trait_predicate(&self) -> PolyTraitPredicate<'tcx> {
1475 // Note that we preserve binding levels
1476 Binder(TraitPredicate { trait_ref: self.0.clone() })
1480 /// Binder is a binder for higher-ranked lifetimes. It is part of the
1481 /// compiler's representation for things like `for<'a> Fn(&'a int)`
1482 /// (which would be represented by the type `PolyTraitRef ==
1483 /// Binder<TraitRef>`). Note that when we skolemize, instantiate,
1484 /// erase, or otherwise "discharge" these bound reons, we change the
1485 /// type from `Binder<T>` to just `T` (see
1486 /// e.g. `liberate_late_bound_regions`).
1487 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1488 pub struct Binder<T>(pub T);
1490 #[derive(Clone, Copy, PartialEq)]
1491 pub enum IntVarValue {
1492 IntType(ast::IntTy),
1493 UintType(ast::UintTy),
1496 #[derive(Clone, Copy, Show)]
1497 pub enum terr_vstore_kind {
1504 #[derive(Clone, Copy, Show)]
1505 pub struct expected_found<T> {
1510 // Data structures used in type unification
1511 #[derive(Clone, Copy, Show)]
1512 pub enum type_err<'tcx> {
1514 terr_unsafety_mismatch(expected_found<ast::Unsafety>),
1515 terr_onceness_mismatch(expected_found<Onceness>),
1516 terr_abi_mismatch(expected_found<abi::Abi>),
1518 terr_sigil_mismatch(expected_found<TraitStore>),
1519 terr_box_mutability,
1520 terr_ptr_mutability,
1521 terr_ref_mutability,
1522 terr_vec_mutability,
1523 terr_tuple_size(expected_found<uint>),
1524 terr_fixed_array_size(expected_found<uint>),
1525 terr_ty_param_size(expected_found<uint>),
1527 terr_regions_does_not_outlive(Region, Region),
1528 terr_regions_not_same(Region, Region),
1529 terr_regions_no_overlap(Region, Region),
1530 terr_regions_insufficiently_polymorphic(BoundRegion, Region),
1531 terr_regions_overly_polymorphic(BoundRegion, Region),
1532 terr_trait_stores_differ(terr_vstore_kind, expected_found<TraitStore>),
1533 terr_sorts(expected_found<Ty<'tcx>>),
1534 terr_integer_as_char,
1535 terr_int_mismatch(expected_found<IntVarValue>),
1536 terr_float_mismatch(expected_found<ast::FloatTy>),
1537 terr_traits(expected_found<ast::DefId>),
1538 terr_builtin_bounds(expected_found<BuiltinBounds>),
1539 terr_variadic_mismatch(expected_found<bool>),
1541 terr_convergence_mismatch(expected_found<bool>),
1542 terr_projection_name_mismatched(expected_found<ast::Name>),
1543 terr_projection_bounds_length(expected_found<uint>),
1546 /// Bounds suitable for a named type parameter like `A` in `fn foo<A>`
1547 /// as well as the existential type parameter in an object type.
1548 #[derive(PartialEq, Eq, Hash, Clone, Show)]
1549 pub struct ParamBounds<'tcx> {
1550 pub region_bounds: Vec<ty::Region>,
1551 pub builtin_bounds: BuiltinBounds,
1552 pub trait_bounds: Vec<PolyTraitRef<'tcx>>,
1553 pub projection_bounds: Vec<PolyProjectionPredicate<'tcx>>,
1556 /// Bounds suitable for an existentially quantified type parameter
1557 /// such as those that appear in object types or closure types. The
1558 /// major difference between this case and `ParamBounds` is that
1559 /// general purpose trait bounds are omitted and there must be
1560 /// *exactly one* region.
1561 #[derive(PartialEq, Eq, Hash, Clone, Show)]
1562 pub struct ExistentialBounds<'tcx> {
1563 pub region_bound: ty::Region,
1564 pub builtin_bounds: BuiltinBounds,
1565 pub projection_bounds: Vec<PolyProjectionPredicate<'tcx>>,
1568 pub type BuiltinBounds = EnumSet<BuiltinBound>;
1570 #[derive(Clone, RustcEncodable, PartialEq, Eq, RustcDecodable, Hash,
1573 pub enum BuiltinBound {
1580 pub fn empty_builtin_bounds() -> BuiltinBounds {
1584 pub fn all_builtin_bounds() -> BuiltinBounds {
1585 let mut set = EnumSet::new();
1586 set.insert(BoundSend);
1587 set.insert(BoundSized);
1588 set.insert(BoundSync);
1592 /// An existential bound that does not implement any traits.
1593 pub fn region_existential_bound<'tcx>(r: ty::Region) -> ExistentialBounds<'tcx> {
1594 ty::ExistentialBounds { region_bound: r,
1595 builtin_bounds: empty_builtin_bounds(),
1596 projection_bounds: Vec::new() }
1599 impl CLike for BuiltinBound {
1600 fn to_uint(&self) -> uint {
1603 fn from_uint(v: uint) -> BuiltinBound {
1604 unsafe { mem::transmute(v) }
1608 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1613 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1618 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1619 pub struct FloatVid {
1623 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
1624 pub struct RegionVid {
1628 #[derive(Clone, Copy, PartialEq, Eq, Hash)]
1634 /// A `FreshTy` is one that is generated as a replacement for an
1635 /// unbound type variable. This is convenient for caching etc. See
1636 /// `middle::infer::freshen` for more details.
1639 // FIXME -- once integral fallback is impl'd, we should remove
1640 // this type. It's only needed to prevent spurious errors for
1641 // integers whose type winds up never being constrained.
1645 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Show, Copy)]
1646 pub enum UnconstrainedNumeric {
1653 #[derive(Clone, RustcEncodable, RustcDecodable, Eq, Hash, Show, Copy)]
1654 pub enum InferRegion {
1656 ReSkolemized(u32, BoundRegion)
1659 impl cmp::PartialEq for InferRegion {
1660 fn eq(&self, other: &InferRegion) -> bool {
1661 match ((*self), *other) {
1662 (ReVar(rva), ReVar(rvb)) => {
1665 (ReSkolemized(rva, _), ReSkolemized(rvb, _)) => {
1671 fn ne(&self, other: &InferRegion) -> bool {
1672 !((*self) == (*other))
1676 impl fmt::Show for TyVid {
1677 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result{
1678 write!(f, "_#{}t", self.index)
1682 impl fmt::Show for IntVid {
1683 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1684 write!(f, "_#{}i", self.index)
1688 impl fmt::Show for FloatVid {
1689 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1690 write!(f, "_#{}f", self.index)
1694 impl fmt::Show for RegionVid {
1695 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1696 write!(f, "'_#{}r", self.index)
1700 impl<'tcx> fmt::Show for FnSig<'tcx> {
1701 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1702 // grr, without tcx not much we can do.
1707 impl fmt::Show for InferTy {
1708 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1710 TyVar(ref v) => v.fmt(f),
1711 IntVar(ref v) => v.fmt(f),
1712 FloatVar(ref v) => v.fmt(f),
1713 FreshTy(v) => write!(f, "FreshTy({})", v),
1714 FreshIntTy(v) => write!(f, "FreshIntTy({})", v),
1719 impl fmt::Show for IntVarValue {
1720 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1722 IntType(ref v) => v.fmt(f),
1723 UintType(ref v) => v.fmt(f),
1728 #[derive(Clone, Show)]
1729 pub struct TypeParameterDef<'tcx> {
1730 pub name: ast::Name,
1731 pub def_id: ast::DefId,
1732 pub space: subst::ParamSpace,
1734 pub bounds: ParamBounds<'tcx>,
1735 pub default: Option<Ty<'tcx>>,
1738 #[derive(RustcEncodable, RustcDecodable, Clone, Show)]
1739 pub struct RegionParameterDef {
1740 pub name: ast::Name,
1741 pub def_id: ast::DefId,
1742 pub space: subst::ParamSpace,
1744 pub bounds: Vec<ty::Region>,
1747 impl RegionParameterDef {
1748 pub fn to_early_bound_region(&self) -> ty::Region {
1749 ty::ReEarlyBound(self.def_id.node, self.space, self.index, self.name)
1753 /// Information about the formal type/lifetime parameters associated
1754 /// with an item or method. Analogous to ast::Generics.
1755 #[derive(Clone, Show)]
1756 pub struct Generics<'tcx> {
1757 pub types: VecPerParamSpace<TypeParameterDef<'tcx>>,
1758 pub regions: VecPerParamSpace<RegionParameterDef>,
1759 pub predicates: VecPerParamSpace<Predicate<'tcx>>,
1762 impl<'tcx> Generics<'tcx> {
1763 pub fn empty() -> Generics<'tcx> {
1765 types: VecPerParamSpace::empty(),
1766 regions: VecPerParamSpace::empty(),
1767 predicates: VecPerParamSpace::empty(),
1771 pub fn has_type_params(&self, space: subst::ParamSpace) -> bool {
1772 !self.types.is_empty_in(space)
1775 pub fn has_region_params(&self, space: subst::ParamSpace) -> bool {
1776 !self.regions.is_empty_in(space)
1779 pub fn is_empty(&self) -> bool {
1780 self.types.is_empty() && self.regions.is_empty()
1783 pub fn to_bounds(&self, tcx: &ty::ctxt<'tcx>, substs: &Substs<'tcx>)
1784 -> GenericBounds<'tcx> {
1786 predicates: self.predicates.subst(tcx, substs),
1791 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1792 pub enum Predicate<'tcx> {
1793 /// Corresponds to `where Foo : Bar<A,B,C>`. `Foo` here would be
1794 /// the `Self` type of the trait reference and `A`, `B`, and `C`
1795 /// would be the parameters in the `TypeSpace`.
1796 Trait(PolyTraitPredicate<'tcx>),
1798 /// where `T1 == T2`.
1799 Equate(PolyEquatePredicate<'tcx>),
1802 RegionOutlives(PolyRegionOutlivesPredicate),
1805 TypeOutlives(PolyTypeOutlivesPredicate<'tcx>),
1807 /// where <T as TraitRef>::Name == X, approximately.
1808 /// See `ProjectionPredicate` struct for details.
1809 Projection(PolyProjectionPredicate<'tcx>),
1812 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1813 pub struct TraitPredicate<'tcx> {
1814 pub trait_ref: Rc<TraitRef<'tcx>>
1816 pub type PolyTraitPredicate<'tcx> = ty::Binder<TraitPredicate<'tcx>>;
1818 impl<'tcx> TraitPredicate<'tcx> {
1819 pub fn def_id(&self) -> ast::DefId {
1820 self.trait_ref.def_id
1823 pub fn input_types(&self) -> &[Ty<'tcx>] {
1824 self.trait_ref.substs.types.as_slice()
1827 pub fn self_ty(&self) -> Ty<'tcx> {
1828 self.trait_ref.self_ty()
1832 impl<'tcx> PolyTraitPredicate<'tcx> {
1833 pub fn def_id(&self) -> ast::DefId {
1838 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1839 pub struct EquatePredicate<'tcx>(pub Ty<'tcx>, pub Ty<'tcx>); // `0 == 1`
1840 pub type PolyEquatePredicate<'tcx> = ty::Binder<EquatePredicate<'tcx>>;
1842 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1843 pub struct OutlivesPredicate<A,B>(pub A, pub B); // `A : B`
1844 pub type PolyOutlivesPredicate<A,B> = ty::Binder<OutlivesPredicate<A,B>>;
1845 pub type PolyRegionOutlivesPredicate = PolyOutlivesPredicate<ty::Region, ty::Region>;
1846 pub type PolyTypeOutlivesPredicate<'tcx> = PolyOutlivesPredicate<Ty<'tcx>, ty::Region>;
1848 /// This kind of predicate has no *direct* correspondent in the
1849 /// syntax, but it roughly corresponds to the syntactic forms:
1851 /// 1. `T : TraitRef<..., Item=Type>`
1852 /// 2. `<T as TraitRef<...>>::Item == Type` (NYI)
1854 /// In particular, form #1 is "desugared" to the combination of a
1855 /// normal trait predicate (`T : TraitRef<...>`) and one of these
1856 /// predicates. Form #2 is a broader form in that it also permits
1857 /// equality between arbitrary types. Processing an instance of Form
1858 /// #2 eventually yields one of these `ProjectionPredicate`
1859 /// instances to normalize the LHS.
1860 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1861 pub struct ProjectionPredicate<'tcx> {
1862 pub projection_ty: ProjectionTy<'tcx>,
1866 pub type PolyProjectionPredicate<'tcx> = Binder<ProjectionPredicate<'tcx>>;
1868 impl<'tcx> PolyProjectionPredicate<'tcx> {
1869 pub fn sort_key(&self) -> (ast::DefId, ast::Name) {
1870 self.0.projection_ty.sort_key()
1874 /// Represents the projection of an associated type. In explicit UFCS
1875 /// form this would be written `<T as Trait<..>>::N`.
1876 #[derive(Clone, PartialEq, Eq, Hash, Show)]
1877 pub struct ProjectionTy<'tcx> {
1878 /// The trait reference `T as Trait<..>`.
1879 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
1881 /// The name `N` of the associated type.
1882 pub item_name: ast::Name,
1885 impl<'tcx> ProjectionTy<'tcx> {
1886 pub fn sort_key(&self) -> (ast::DefId, ast::Name) {
1887 (self.trait_ref.def_id, self.item_name)
1891 pub trait ToPolyTraitRef<'tcx> {
1892 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx>;
1895 impl<'tcx> ToPolyTraitRef<'tcx> for Rc<TraitRef<'tcx>> {
1896 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1897 assert!(!self.has_escaping_regions());
1898 ty::Binder(self.clone())
1902 impl<'tcx> ToPolyTraitRef<'tcx> for PolyTraitPredicate<'tcx> {
1903 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1904 // We are just preserving the binder levels here
1905 ty::Binder(self.0.trait_ref.clone())
1909 impl<'tcx> ToPolyTraitRef<'tcx> for PolyProjectionPredicate<'tcx> {
1910 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1911 // Note: unlike with TraitRef::to_poly_trait_ref(),
1912 // self.0.trait_ref is permitted to have escaping regions.
1913 // This is because here `self` has a `Binder` and so does our
1914 // return value, so we are preserving the number of binding
1916 ty::Binder(self.0.projection_ty.trait_ref.clone())
1920 pub trait AsPredicate<'tcx> {
1921 fn as_predicate(&self) -> Predicate<'tcx>;
1924 impl<'tcx> AsPredicate<'tcx> for Rc<TraitRef<'tcx>> {
1925 fn as_predicate(&self) -> Predicate<'tcx> {
1926 // we're about to add a binder, so let's check that we don't
1927 // accidentally capture anything, or else that might be some
1928 // weird debruijn accounting.
1929 assert!(!self.has_escaping_regions());
1931 ty::Predicate::Trait(ty::Binder(ty::TraitPredicate {
1932 trait_ref: self.clone()
1937 impl<'tcx> AsPredicate<'tcx> for PolyTraitRef<'tcx> {
1938 fn as_predicate(&self) -> Predicate<'tcx> {
1939 ty::Predicate::Trait(self.to_poly_trait_predicate())
1943 impl<'tcx> AsPredicate<'tcx> for PolyEquatePredicate<'tcx> {
1944 fn as_predicate(&self) -> Predicate<'tcx> {
1945 Predicate::Equate(self.clone())
1949 impl<'tcx> AsPredicate<'tcx> for PolyRegionOutlivesPredicate {
1950 fn as_predicate(&self) -> Predicate<'tcx> {
1951 Predicate::RegionOutlives(self.clone())
1955 impl<'tcx> AsPredicate<'tcx> for PolyTypeOutlivesPredicate<'tcx> {
1956 fn as_predicate(&self) -> Predicate<'tcx> {
1957 Predicate::TypeOutlives(self.clone())
1961 impl<'tcx> AsPredicate<'tcx> for PolyProjectionPredicate<'tcx> {
1962 fn as_predicate(&self) -> Predicate<'tcx> {
1963 Predicate::Projection(self.clone())
1967 impl<'tcx> Predicate<'tcx> {
1968 pub fn has_escaping_regions(&self) -> bool {
1970 Predicate::Trait(ref trait_ref) => trait_ref.has_escaping_regions(),
1971 Predicate::Equate(ref p) => p.has_escaping_regions(),
1972 Predicate::RegionOutlives(ref p) => p.has_escaping_regions(),
1973 Predicate::TypeOutlives(ref p) => p.has_escaping_regions(),
1974 Predicate::Projection(ref p) => p.has_escaping_regions(),
1978 pub fn to_opt_poly_trait_ref(&self) -> Option<PolyTraitRef<'tcx>> {
1980 Predicate::Trait(ref t) => {
1981 Some(t.to_poly_trait_ref())
1983 Predicate::Projection(..) |
1984 Predicate::Equate(..) |
1985 Predicate::RegionOutlives(..) |
1986 Predicate::TypeOutlives(..) => {
1993 /// Represents the bounds declared on a particular set of type
1994 /// parameters. Should eventually be generalized into a flag list of
1995 /// where clauses. You can obtain a `GenericBounds` list from a
1996 /// `Generics` by using the `to_bounds` method. Note that this method
1997 /// reflects an important semantic invariant of `GenericBounds`: while
1998 /// the bounds in a `Generics` are expressed in terms of the bound type
1999 /// parameters of the impl/trait/whatever, a `GenericBounds` instance
2000 /// represented a set of bounds for some particular instantiation,
2001 /// meaning that the generic parameters have been substituted with
2006 /// struct Foo<T,U:Bar<T>> { ... }
2008 /// Here, the `Generics` for `Foo` would contain a list of bounds like
2009 /// `[[], [U:Bar<T>]]`. Now if there were some particular reference
2010 /// like `Foo<int,uint>`, then the `GenericBounds` would be `[[],
2011 /// [uint:Bar<int>]]`.
2012 #[derive(Clone, Show)]
2013 pub struct GenericBounds<'tcx> {
2014 pub predicates: VecPerParamSpace<Predicate<'tcx>>,
2017 impl<'tcx> GenericBounds<'tcx> {
2018 pub fn empty() -> GenericBounds<'tcx> {
2019 GenericBounds { predicates: VecPerParamSpace::empty() }
2022 pub fn has_escaping_regions(&self) -> bool {
2023 self.predicates.any(|p| p.has_escaping_regions())
2026 pub fn is_empty(&self) -> bool {
2027 self.predicates.is_empty()
2031 impl<'tcx> TraitRef<'tcx> {
2032 pub fn new(def_id: ast::DefId, substs: &'tcx Substs<'tcx>) -> TraitRef<'tcx> {
2033 TraitRef { def_id: def_id, substs: substs }
2036 pub fn self_ty(&self) -> Ty<'tcx> {
2037 self.substs.self_ty().unwrap()
2040 pub fn input_types(&self) -> &[Ty<'tcx>] {
2041 // Select only the "input types" from a trait-reference. For
2042 // now this is all the types that appear in the
2043 // trait-reference, but it should eventually exclude
2044 // associated types.
2045 self.substs.types.as_slice()
2049 /// When type checking, we use the `ParameterEnvironment` to track
2050 /// details about the type/lifetime parameters that are in scope.
2051 /// It primarily stores the bounds information.
2053 /// Note: This information might seem to be redundant with the data in
2054 /// `tcx.ty_param_defs`, but it is not. That table contains the
2055 /// parameter definitions from an "outside" perspective, but this
2056 /// struct will contain the bounds for a parameter as seen from inside
2057 /// the function body. Currently the only real distinction is that
2058 /// bound lifetime parameters are replaced with free ones, but in the
2059 /// future I hope to refine the representation of types so as to make
2060 /// more distinctions clearer.
2062 pub struct ParameterEnvironment<'a, 'tcx:'a> {
2063 pub tcx: &'a ctxt<'tcx>,
2065 /// A substitution that can be applied to move from
2066 /// the "outer" view of a type or method to the "inner" view.
2067 /// In general, this means converting from bound parameters to
2068 /// free parameters. Since we currently represent bound/free type
2069 /// parameters in the same way, this only has an effect on regions.
2070 pub free_substs: Substs<'tcx>,
2072 /// Each type parameter has an implicit region bound that
2073 /// indicates it must outlive at least the function body (the user
2074 /// may specify stronger requirements). This field indicates the
2075 /// region of the callee.
2076 pub implicit_region_bound: ty::Region,
2078 /// Obligations that the caller must satisfy. This is basically
2079 /// the set of bounds on the in-scope type parameters, translated
2080 /// into Obligations.
2081 pub caller_bounds: ty::GenericBounds<'tcx>,
2083 /// Caches the results of trait selection. This cache is used
2084 /// for things that have to do with the parameters in scope.
2085 pub selection_cache: traits::SelectionCache<'tcx>,
2088 impl<'a, 'tcx> ParameterEnvironment<'a, 'tcx> {
2089 pub fn for_item(cx: &'a ctxt<'tcx>, id: NodeId) -> ParameterEnvironment<'a, 'tcx> {
2090 match cx.map.find(id) {
2091 Some(ast_map::NodeImplItem(ref impl_item)) => {
2093 ast::MethodImplItem(ref method) => {
2094 let method_def_id = ast_util::local_def(id);
2095 match ty::impl_or_trait_item(cx, method_def_id) {
2096 MethodTraitItem(ref method_ty) => {
2097 let method_generics = &method_ty.generics;
2098 construct_parameter_environment(
2101 method.pe_body().id)
2103 TypeTraitItem(_) => {
2105 .bug("ParameterEnvironment::for_item(): \
2106 can't create a parameter environment \
2107 for type trait items")
2111 ast::TypeImplItem(_) => {
2112 cx.sess.bug("ParameterEnvironment::for_item(): \
2113 can't create a parameter environment \
2114 for type impl items")
2118 Some(ast_map::NodeTraitItem(trait_method)) => {
2119 match *trait_method {
2120 ast::RequiredMethod(ref required) => {
2121 cx.sess.span_bug(required.span,
2122 "ParameterEnvironment::for_item():
2123 can't create a parameter \
2124 environment for required trait \
2127 ast::ProvidedMethod(ref method) => {
2128 let method_def_id = ast_util::local_def(id);
2129 match ty::impl_or_trait_item(cx, method_def_id) {
2130 MethodTraitItem(ref method_ty) => {
2131 let method_generics = &method_ty.generics;
2132 construct_parameter_environment(
2135 method.pe_body().id)
2137 TypeTraitItem(_) => {
2139 .bug("ParameterEnvironment::for_item(): \
2140 can't create a parameter environment \
2141 for type trait items")
2145 ast::TypeTraitItem(_) => {
2146 cx.sess.bug("ParameterEnvironment::from_item(): \
2147 can't create a parameter environment \
2148 for type trait items")
2152 Some(ast_map::NodeItem(item)) => {
2154 ast::ItemFn(_, _, _, _, ref body) => {
2155 // We assume this is a function.
2156 let fn_def_id = ast_util::local_def(id);
2157 let fn_pty = ty::lookup_item_type(cx, fn_def_id);
2159 construct_parameter_environment(cx,
2164 ast::ItemStruct(..) |
2166 ast::ItemConst(..) |
2167 ast::ItemStatic(..) => {
2168 let def_id = ast_util::local_def(id);
2169 let pty = ty::lookup_item_type(cx, def_id);
2170 construct_parameter_environment(cx, &pty.generics, id)
2173 cx.sess.span_bug(item.span,
2174 "ParameterEnvironment::from_item():
2175 can't create a parameter \
2176 environment for this kind of item")
2180 Some(ast_map::NodeExpr(..)) => {
2181 // This is a convenience to allow closures to work.
2182 ParameterEnvironment::for_item(cx, cx.map.get_parent(id))
2185 cx.sess.bug(format!("ParameterEnvironment::from_item(): \
2186 `{}` is not an item",
2187 cx.map.node_to_string(id))[])
2193 /// A "type scheme", in ML terminology, is a type combined with some
2194 /// set of generic types that the type is, well, generic over. In Rust
2195 /// terms, it is the "type" of a fn item or struct -- this type will
2196 /// include various generic parameters that must be substituted when
2197 /// the item/struct is referenced. That is called converting the type
2198 /// scheme to a monotype.
2200 /// - `generics`: the set of type parameters and their bounds
2201 /// - `ty`: the base types, which may reference the parameters defined
2204 /// Note that TypeSchemes are also sometimes called "polytypes" (and
2205 /// in fact this struct used to carry that name, so you may find some
2206 /// stray references in a comment or something). We try to reserve the
2207 /// "poly" prefix to refer to higher-ranked things, as in
2209 #[derive(Clone, Show)]
2210 pub struct TypeScheme<'tcx> {
2211 pub generics: Generics<'tcx>,
2215 /// As `TypeScheme` but for a trait ref.
2216 pub struct TraitDef<'tcx> {
2217 pub unsafety: ast::Unsafety,
2219 /// Generic type definitions. Note that `Self` is listed in here
2220 /// as having a single bound, the trait itself (e.g., in the trait
2221 /// `Eq`, there is a single bound `Self : Eq`). This is so that
2222 /// default methods get to assume that the `Self` parameters
2223 /// implements the trait.
2224 pub generics: Generics<'tcx>,
2226 /// The "supertrait" bounds.
2227 pub bounds: ParamBounds<'tcx>,
2229 pub trait_ref: Rc<ty::TraitRef<'tcx>>,
2231 /// A list of the associated types defined in this trait. Useful
2232 /// for resolving `X::Foo` type markers.
2233 pub associated_type_names: Vec<ast::Name>,
2236 /// Records the substitutions used to translate the polytype for an
2237 /// item into the monotype of an item reference.
2239 pub struct ItemSubsts<'tcx> {
2240 pub substs: Substs<'tcx>,
2243 /// Records information about each unboxed closure.
2245 pub struct UnboxedClosure<'tcx> {
2246 /// The type of the unboxed closure.
2247 pub closure_type: ClosureTy<'tcx>,
2248 /// The kind of unboxed closure this is.
2249 pub kind: UnboxedClosureKind,
2252 #[derive(Clone, Copy, PartialEq, Eq, Show)]
2253 pub enum UnboxedClosureKind {
2254 FnUnboxedClosureKind,
2255 FnMutUnboxedClosureKind,
2256 FnOnceUnboxedClosureKind,
2259 impl UnboxedClosureKind {
2260 pub fn trait_did(&self, cx: &ctxt) -> ast::DefId {
2261 let result = match *self {
2262 FnUnboxedClosureKind => cx.lang_items.require(FnTraitLangItem),
2263 FnMutUnboxedClosureKind => {
2264 cx.lang_items.require(FnMutTraitLangItem)
2266 FnOnceUnboxedClosureKind => {
2267 cx.lang_items.require(FnOnceTraitLangItem)
2271 Ok(trait_did) => trait_did,
2272 Err(err) => cx.sess.fatal(err[]),
2277 pub trait UnboxedClosureTyper<'tcx> {
2278 fn param_env<'a>(&'a self) -> &'a ty::ParameterEnvironment<'a, 'tcx>;
2280 fn unboxed_closure_kind(&self,
2282 -> ty::UnboxedClosureKind;
2284 fn unboxed_closure_type(&self,
2286 substs: &subst::Substs<'tcx>)
2287 -> ty::ClosureTy<'tcx>;
2289 // Returns `None` if the upvar types cannot yet be definitively determined.
2290 fn unboxed_closure_upvars(&self,
2292 substs: &Substs<'tcx>)
2293 -> Option<Vec<UnboxedClosureUpvar<'tcx>>>;
2296 impl<'tcx> CommonTypes<'tcx> {
2297 fn new(arena: &'tcx TypedArena<TyS<'tcx>>,
2298 interner: &mut FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>)
2299 -> CommonTypes<'tcx>
2302 bool: intern_ty(arena, interner, ty_bool),
2303 char: intern_ty(arena, interner, ty_char),
2304 err: intern_ty(arena, interner, ty_err),
2305 int: intern_ty(arena, interner, ty_int(ast::TyI)),
2306 i8: intern_ty(arena, interner, ty_int(ast::TyI8)),
2307 i16: intern_ty(arena, interner, ty_int(ast::TyI16)),
2308 i32: intern_ty(arena, interner, ty_int(ast::TyI32)),
2309 i64: intern_ty(arena, interner, ty_int(ast::TyI64)),
2310 uint: intern_ty(arena, interner, ty_uint(ast::TyU)),
2311 u8: intern_ty(arena, interner, ty_uint(ast::TyU8)),
2312 u16: intern_ty(arena, interner, ty_uint(ast::TyU16)),
2313 u32: intern_ty(arena, interner, ty_uint(ast::TyU32)),
2314 u64: intern_ty(arena, interner, ty_uint(ast::TyU64)),
2315 f32: intern_ty(arena, interner, ty_float(ast::TyF32)),
2316 f64: intern_ty(arena, interner, ty_float(ast::TyF64)),
2321 pub fn mk_ctxt<'tcx>(s: Session,
2322 arenas: &'tcx CtxtArenas<'tcx>,
2324 named_region_map: resolve_lifetime::NamedRegionMap,
2325 map: ast_map::Map<'tcx>,
2326 freevars: RefCell<FreevarMap>,
2327 capture_modes: RefCell<CaptureModeMap>,
2328 region_maps: middle::region::RegionMaps,
2329 lang_items: middle::lang_items::LanguageItems,
2330 stability: stability::Index) -> ctxt<'tcx>
2332 let mut interner = FnvHashMap::new();
2333 let common_types = CommonTypes::new(&arenas.type_, &mut interner);
2337 interner: RefCell::new(interner),
2338 substs_interner: RefCell::new(FnvHashMap::new()),
2339 bare_fn_interner: RefCell::new(FnvHashMap::new()),
2340 region_interner: RefCell::new(FnvHashMap::new()),
2341 types: common_types,
2342 named_region_map: named_region_map,
2343 item_variance_map: RefCell::new(DefIdMap::new()),
2344 variance_computed: Cell::new(false),
2347 region_maps: region_maps,
2348 node_types: RefCell::new(FnvHashMap::new()),
2349 item_substs: RefCell::new(NodeMap::new()),
2350 trait_refs: RefCell::new(NodeMap::new()),
2351 trait_defs: RefCell::new(DefIdMap::new()),
2352 object_cast_map: RefCell::new(NodeMap::new()),
2354 intrinsic_defs: RefCell::new(DefIdMap::new()),
2356 tcache: RefCell::new(DefIdMap::new()),
2357 rcache: RefCell::new(FnvHashMap::new()),
2358 short_names_cache: RefCell::new(FnvHashMap::new()),
2359 tc_cache: RefCell::new(FnvHashMap::new()),
2360 ast_ty_to_ty_cache: RefCell::new(NodeMap::new()),
2361 enum_var_cache: RefCell::new(DefIdMap::new()),
2362 impl_or_trait_items: RefCell::new(DefIdMap::new()),
2363 trait_item_def_ids: RefCell::new(DefIdMap::new()),
2364 trait_items_cache: RefCell::new(DefIdMap::new()),
2365 impl_trait_cache: RefCell::new(DefIdMap::new()),
2366 ty_param_defs: RefCell::new(NodeMap::new()),
2367 adjustments: RefCell::new(NodeMap::new()),
2368 normalized_cache: RefCell::new(FnvHashMap::new()),
2369 lang_items: lang_items,
2370 provided_method_sources: RefCell::new(DefIdMap::new()),
2371 struct_fields: RefCell::new(DefIdMap::new()),
2372 destructor_for_type: RefCell::new(DefIdMap::new()),
2373 destructors: RefCell::new(DefIdSet::new()),
2374 trait_impls: RefCell::new(DefIdMap::new()),
2375 inherent_impls: RefCell::new(DefIdMap::new()),
2376 impl_items: RefCell::new(DefIdMap::new()),
2377 used_unsafe: RefCell::new(NodeSet::new()),
2378 used_mut_nodes: RefCell::new(NodeSet::new()),
2379 populated_external_types: RefCell::new(DefIdSet::new()),
2380 populated_external_traits: RefCell::new(DefIdSet::new()),
2381 upvar_borrow_map: RefCell::new(FnvHashMap::new()),
2382 extern_const_statics: RefCell::new(DefIdMap::new()),
2383 extern_const_variants: RefCell::new(DefIdMap::new()),
2384 method_map: RefCell::new(FnvHashMap::new()),
2385 dependency_formats: RefCell::new(FnvHashMap::new()),
2386 unboxed_closures: RefCell::new(DefIdMap::new()),
2387 node_lint_levels: RefCell::new(FnvHashMap::new()),
2388 transmute_restrictions: RefCell::new(Vec::new()),
2389 stability: RefCell::new(stability),
2390 capture_modes: capture_modes,
2391 associated_types: RefCell::new(DefIdMap::new()),
2392 selection_cache: traits::SelectionCache::new(),
2393 repr_hint_cache: RefCell::new(DefIdMap::new()),
2394 type_impls_copy_cache: RefCell::new(HashMap::new()),
2395 type_impls_sized_cache: RefCell::new(HashMap::new()),
2396 object_safety_cache: RefCell::new(DefIdMap::new()),
2400 // Type constructors
2402 impl<'tcx> ctxt<'tcx> {
2403 pub fn mk_substs(&self, substs: Substs<'tcx>) -> &'tcx Substs<'tcx> {
2404 if let Some(substs) = self.substs_interner.borrow().get(&substs) {
2408 let substs = self.arenas.substs.alloc(substs);
2409 self.substs_interner.borrow_mut().insert(substs, substs);
2413 pub fn mk_bare_fn(&self, bare_fn: BareFnTy<'tcx>) -> &'tcx BareFnTy<'tcx> {
2414 if let Some(bare_fn) = self.bare_fn_interner.borrow().get(&bare_fn) {
2418 let bare_fn = self.arenas.bare_fn.alloc(bare_fn);
2419 self.bare_fn_interner.borrow_mut().insert(bare_fn, bare_fn);
2423 pub fn mk_region(&self, region: Region) -> &'tcx Region {
2424 if let Some(region) = self.region_interner.borrow().get(®ion) {
2428 let region = self.arenas.region.alloc(region);
2429 self.region_interner.borrow_mut().insert(region, region);
2433 pub fn unboxed_closure_kind(&self,
2435 -> ty::UnboxedClosureKind
2437 self.unboxed_closures.borrow()[def_id].kind
2440 pub fn unboxed_closure_type(&self,
2442 substs: &subst::Substs<'tcx>)
2443 -> ty::ClosureTy<'tcx>
2445 self.unboxed_closures.borrow()[def_id].closure_type.subst(self, substs)
2449 // Interns a type/name combination, stores the resulting box in cx.interner,
2450 // and returns the box as cast to an unsafe ptr (see comments for Ty above).
2451 pub fn mk_t<'tcx>(cx: &ctxt<'tcx>, st: sty<'tcx>) -> Ty<'tcx> {
2452 let mut interner = cx.interner.borrow_mut();
2453 intern_ty(&cx.arenas.type_, &mut *interner, st)
2456 fn intern_ty<'tcx>(type_arena: &'tcx TypedArena<TyS<'tcx>>,
2457 interner: &mut FnvHashMap<InternedTy<'tcx>, Ty<'tcx>>,
2461 match interner.get(&st) {
2462 Some(ty) => return *ty,
2466 let flags = FlagComputation::for_sty(&st);
2468 let ty = type_arena.alloc(TyS {
2471 region_depth: flags.depth,
2474 debug!("Interned type: {} Pointer: {}",
2475 ty, ty as *const _);
2477 interner.insert(InternedTy { ty: ty }, ty);
2482 struct FlagComputation {
2485 // maximum depth of any bound region that we have seen thus far
2489 impl FlagComputation {
2490 fn new() -> FlagComputation {
2491 FlagComputation { flags: NO_TYPE_FLAGS, depth: 0 }
2494 fn for_sty(st: &sty) -> FlagComputation {
2495 let mut result = FlagComputation::new();
2500 fn add_flags(&mut self, flags: TypeFlags) {
2501 self.flags = self.flags | flags;
2504 fn add_depth(&mut self, depth: u32) {
2505 if depth > self.depth {
2510 /// Adds the flags/depth from a set of types that appear within the current type, but within a
2512 fn add_bound_computation(&mut self, computation: &FlagComputation) {
2513 self.add_flags(computation.flags);
2515 // The types that contributed to `computation` occured within
2516 // a region binder, so subtract one from the region depth
2517 // within when adding the depth to `self`.
2518 let depth = computation.depth;
2520 self.add_depth(depth - 1);
2524 fn add_sty(&mut self, st: &sty) {
2534 // You might think that we could just return ty_err for
2535 // any type containing ty_err as a component, and get
2536 // rid of the HAS_TY_ERR flag -- likewise for ty_bot (with
2537 // the exception of function types that return bot).
2538 // But doing so caused sporadic memory corruption, and
2539 // neither I (tjc) nor nmatsakis could figure out why,
2540 // so we're doing it this way.
2542 self.add_flags(HAS_TY_ERR)
2545 &ty_param(ref p) => {
2546 if p.space == subst::SelfSpace {
2547 self.add_flags(HAS_SELF);
2549 self.add_flags(HAS_PARAMS);
2553 &ty_unboxed_closure(_, region, substs) => {
2554 self.add_region(*region);
2555 self.add_substs(substs);
2559 self.add_flags(HAS_TY_INFER)
2562 &ty_enum(_, substs) | &ty_struct(_, substs) => {
2563 self.add_substs(substs);
2566 &ty_projection(ref data) => {
2567 self.add_flags(HAS_PROJECTION);
2568 self.add_substs(data.trait_ref.substs);
2571 &ty_trait(box TyTrait { ref principal, ref bounds }) => {
2572 let mut computation = FlagComputation::new();
2573 computation.add_substs(principal.0.substs);
2574 self.add_bound_computation(&computation);
2576 self.add_bounds(bounds);
2579 &ty_uniq(tt) | &ty_vec(tt, _) | &ty_open(tt) => {
2587 &ty_rptr(r, ref m) => {
2588 self.add_region(*r);
2592 &ty_tup(ref ts) => {
2596 &ty_bare_fn(_, ref f) => {
2597 self.add_fn_sig(&f.sig);
2602 fn add_ty(&mut self, ty: Ty) {
2603 self.add_flags(ty.flags);
2604 self.add_depth(ty.region_depth);
2607 fn add_tys(&mut self, tys: &[Ty]) {
2608 for &ty in tys.iter() {
2613 fn add_fn_sig(&mut self, fn_sig: &PolyFnSig) {
2614 let mut computation = FlagComputation::new();
2616 computation.add_tys(fn_sig.0.inputs[]);
2618 if let ty::FnConverging(output) = fn_sig.0.output {
2619 computation.add_ty(output);
2622 self.add_bound_computation(&computation);
2625 fn add_region(&mut self, r: Region) {
2626 self.add_flags(HAS_REGIONS);
2628 ty::ReInfer(_) => { self.add_flags(HAS_RE_INFER); }
2629 ty::ReLateBound(debruijn, _) => {
2630 self.add_flags(HAS_RE_LATE_BOUND);
2631 self.add_depth(debruijn.depth);
2637 fn add_substs(&mut self, substs: &Substs) {
2638 self.add_tys(substs.types.as_slice());
2639 match substs.regions {
2640 subst::ErasedRegions => {}
2641 subst::NonerasedRegions(ref regions) => {
2642 for &r in regions.iter() {
2649 fn add_bounds(&mut self, bounds: &ExistentialBounds) {
2650 self.add_region(bounds.region_bound);
2654 pub fn mk_mach_int<'tcx>(tcx: &ctxt<'tcx>, tm: ast::IntTy) -> Ty<'tcx> {
2656 ast::TyI => tcx.types.int,
2657 ast::TyI8 => tcx.types.i8,
2658 ast::TyI16 => tcx.types.i16,
2659 ast::TyI32 => tcx.types.i32,
2660 ast::TyI64 => tcx.types.i64,
2664 pub fn mk_mach_uint<'tcx>(tcx: &ctxt<'tcx>, tm: ast::UintTy) -> Ty<'tcx> {
2666 ast::TyU => tcx.types.uint,
2667 ast::TyU8 => tcx.types.u8,
2668 ast::TyU16 => tcx.types.u16,
2669 ast::TyU32 => tcx.types.u32,
2670 ast::TyU64 => tcx.types.u64,
2674 pub fn mk_mach_float<'tcx>(tcx: &ctxt<'tcx>, tm: ast::FloatTy) -> Ty<'tcx> {
2676 ast::TyF32 => tcx.types.f32,
2677 ast::TyF64 => tcx.types.f64,
2681 pub fn mk_str<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2685 pub fn mk_str_slice<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, m: ast::Mutability) -> Ty<'tcx> {
2688 ty: mk_t(cx, ty_str),
2693 pub fn mk_enum<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId, substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
2694 // take a copy of substs so that we own the vectors inside
2695 mk_t(cx, ty_enum(did, substs))
2698 pub fn mk_uniq<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_uniq(ty)) }
2700 pub fn mk_ptr<'tcx>(cx: &ctxt<'tcx>, tm: mt<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_ptr(tm)) }
2702 pub fn mk_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, tm: mt<'tcx>) -> Ty<'tcx> {
2703 mk_t(cx, ty_rptr(r, tm))
2706 pub fn mk_mut_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
2707 mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutMutable})
2709 pub fn mk_imm_rptr<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, ty: Ty<'tcx>) -> Ty<'tcx> {
2710 mk_rptr(cx, r, mt {ty: ty, mutbl: ast::MutImmutable})
2713 pub fn mk_mut_ptr<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
2714 mk_ptr(cx, mt {ty: ty, mutbl: ast::MutMutable})
2717 pub fn mk_imm_ptr<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
2718 mk_ptr(cx, mt {ty: ty, mutbl: ast::MutImmutable})
2721 pub fn mk_nil_ptr<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2722 mk_ptr(cx, mt {ty: mk_nil(cx), mutbl: ast::MutImmutable})
2725 pub fn mk_vec<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>, sz: Option<uint>) -> Ty<'tcx> {
2726 mk_t(cx, ty_vec(ty, sz))
2729 pub fn mk_slice<'tcx>(cx: &ctxt<'tcx>, r: &'tcx Region, tm: mt<'tcx>) -> Ty<'tcx> {
2732 ty: mk_vec(cx, tm.ty, None),
2737 pub fn mk_tup<'tcx>(cx: &ctxt<'tcx>, ts: Vec<Ty<'tcx>>) -> Ty<'tcx> {
2738 mk_t(cx, ty_tup(ts))
2741 pub fn mk_nil<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2742 mk_tup(cx, Vec::new())
2745 pub fn mk_bare_fn<'tcx>(cx: &ctxt<'tcx>,
2746 opt_def_id: Option<ast::DefId>,
2747 fty: &'tcx BareFnTy<'tcx>) -> Ty<'tcx> {
2748 mk_t(cx, ty_bare_fn(opt_def_id, fty))
2751 pub fn mk_ctor_fn<'tcx>(cx: &ctxt<'tcx>,
2753 input_tys: &[Ty<'tcx>],
2754 output: Ty<'tcx>) -> Ty<'tcx> {
2755 let input_args = input_tys.iter().map(|ty| *ty).collect();
2758 cx.mk_bare_fn(BareFnTy {
2759 unsafety: ast::Unsafety::Normal,
2761 sig: ty::Binder(FnSig {
2763 output: ty::FnConverging(output),
2769 pub fn mk_trait<'tcx>(cx: &ctxt<'tcx>,
2770 principal: ty::PolyTraitRef<'tcx>,
2771 bounds: ExistentialBounds<'tcx>)
2774 assert!(bound_list_is_sorted(bounds.projection_bounds.as_slice()));
2776 let inner = box TyTrait {
2777 principal: principal,
2780 mk_t(cx, ty_trait(inner))
2783 fn bound_list_is_sorted(bounds: &[ty::PolyProjectionPredicate]) -> bool {
2784 bounds.len() == 0 ||
2785 bounds[1..].iter().enumerate().all(
2786 |(index, bound)| bounds[index].sort_key() <= bound.sort_key())
2789 pub fn sort_bounds_list(bounds: &mut [ty::PolyProjectionPredicate]) {
2790 bounds.sort_by(|a, b| a.sort_key().cmp(&b.sort_key()))
2793 pub fn mk_projection<'tcx>(cx: &ctxt<'tcx>,
2794 trait_ref: Rc<ty::TraitRef<'tcx>>,
2795 item_name: ast::Name)
2797 // take a copy of substs so that we own the vectors inside
2798 let inner = ProjectionTy { trait_ref: trait_ref, item_name: item_name };
2799 mk_t(cx, ty_projection(inner))
2802 pub fn mk_struct<'tcx>(cx: &ctxt<'tcx>, struct_id: ast::DefId,
2803 substs: &'tcx Substs<'tcx>) -> Ty<'tcx> {
2804 // take a copy of substs so that we own the vectors inside
2805 mk_t(cx, ty_struct(struct_id, substs))
2808 pub fn mk_unboxed_closure<'tcx>(cx: &ctxt<'tcx>, closure_id: ast::DefId,
2809 region: &'tcx Region, substs: &'tcx Substs<'tcx>)
2811 mk_t(cx, ty_unboxed_closure(closure_id, region, substs))
2814 pub fn mk_var<'tcx>(cx: &ctxt<'tcx>, v: TyVid) -> Ty<'tcx> {
2815 mk_infer(cx, TyVar(v))
2818 pub fn mk_int_var<'tcx>(cx: &ctxt<'tcx>, v: IntVid) -> Ty<'tcx> {
2819 mk_infer(cx, IntVar(v))
2822 pub fn mk_float_var<'tcx>(cx: &ctxt<'tcx>, v: FloatVid) -> Ty<'tcx> {
2823 mk_infer(cx, FloatVar(v))
2826 pub fn mk_infer<'tcx>(cx: &ctxt<'tcx>, it: InferTy) -> Ty<'tcx> {
2827 mk_t(cx, ty_infer(it))
2830 pub fn mk_param<'tcx>(cx: &ctxt<'tcx>,
2831 space: subst::ParamSpace,
2833 name: ast::Name) -> Ty<'tcx> {
2834 mk_t(cx, ty_param(ParamTy { space: space, idx: index, name: name }))
2837 pub fn mk_self_type<'tcx>(cx: &ctxt<'tcx>) -> Ty<'tcx> {
2838 mk_param(cx, subst::SelfSpace, 0, special_idents::type_self.name)
2841 pub fn mk_param_from_def<'tcx>(cx: &ctxt<'tcx>, def: &TypeParameterDef) -> Ty<'tcx> {
2842 mk_param(cx, def.space, def.index, def.name)
2845 pub fn mk_open<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> { mk_t(cx, ty_open(ty)) }
2847 impl<'tcx> TyS<'tcx> {
2848 /// Iterator that walks `self` and any types reachable from
2849 /// `self`, in depth-first order. Note that just walks the types
2850 /// that appear in `self`, it does not descend into the fields of
2851 /// structs or variants. For example:
2855 /// Foo<Bar<int>> => { Foo<Bar<int>>, Bar<int>, int }
2856 /// [int] => { [int], int }
2858 pub fn walk(&'tcx self) -> TypeWalker<'tcx> {
2859 TypeWalker::new(self)
2862 /// Iterator that walks types reachable from `self`, in
2863 /// depth-first order. Note that this is a shallow walk. For
2868 /// Foo<Bar<int>> => { Bar<int>, int }
2869 /// [int] => { int }
2871 pub fn walk_children(&'tcx self) -> TypeWalker<'tcx> {
2872 // Walks type reachable from `self` but not `self
2873 let mut walker = self.walk();
2874 let r = walker.next();
2875 assert_eq!(r, Some(self));
2880 pub fn walk_ty<'tcx, F>(ty_root: Ty<'tcx>, mut f: F)
2881 where F: FnMut(Ty<'tcx>),
2883 for ty in ty_root.walk() {
2888 /// Walks `ty` and any types appearing within `ty`, invoking the
2889 /// callback `f` on each type. If the callback returns false, then the
2890 /// children of the current type are ignored.
2892 /// Note: prefer `ty.walk()` where possible.
2893 pub fn maybe_walk_ty<'tcx,F>(ty_root: Ty<'tcx>, mut f: F)
2894 where F : FnMut(Ty<'tcx>) -> bool
2896 let mut walker = ty_root.walk();
2897 while let Some(ty) = walker.next() {
2899 walker.skip_current_subtree();
2904 // Folds types from the bottom up.
2905 pub fn fold_ty<'tcx, F>(cx: &ctxt<'tcx>, t0: Ty<'tcx>,
2908 F: FnMut(Ty<'tcx>) -> Ty<'tcx>,
2910 let mut f = ty_fold::BottomUpFolder {tcx: cx, fldop: fldop};
2915 pub fn new(space: subst::ParamSpace,
2919 ParamTy { space: space, idx: index, name: name }
2922 pub fn for_self() -> ParamTy {
2923 ParamTy::new(subst::SelfSpace, 0, special_idents::type_self.name)
2926 pub fn for_def(def: &TypeParameterDef) -> ParamTy {
2927 ParamTy::new(def.space, def.index, def.name)
2930 pub fn to_ty<'tcx>(self, tcx: &ty::ctxt<'tcx>) -> Ty<'tcx> {
2931 ty::mk_param(tcx, self.space, self.idx, self.name)
2934 pub fn is_self(&self) -> bool {
2935 self.space == subst::SelfSpace && self.idx == 0
2939 impl<'tcx> ItemSubsts<'tcx> {
2940 pub fn empty() -> ItemSubsts<'tcx> {
2941 ItemSubsts { substs: Substs::empty() }
2944 pub fn is_noop(&self) -> bool {
2945 self.substs.is_noop()
2949 impl<'tcx> ParamBounds<'tcx> {
2950 pub fn empty() -> ParamBounds<'tcx> {
2952 builtin_bounds: empty_builtin_bounds(),
2953 trait_bounds: Vec::new(),
2954 region_bounds: Vec::new(),
2955 projection_bounds: Vec::new(),
2962 pub fn type_is_nil(ty: Ty) -> bool {
2964 ty_tup(ref tys) => tys.is_empty(),
2969 pub fn type_is_error(ty: Ty) -> bool {
2970 ty.flags.intersects(HAS_TY_ERR)
2973 pub fn type_needs_subst(ty: Ty) -> bool {
2974 ty.flags.intersects(NEEDS_SUBST)
2977 pub fn trait_ref_contains_error(tref: &ty::TraitRef) -> bool {
2978 tref.substs.types.any(|&ty| type_is_error(ty))
2981 pub fn type_is_ty_var(ty: Ty) -> bool {
2983 ty_infer(TyVar(_)) => true,
2988 pub fn type_is_bool(ty: Ty) -> bool { ty.sty == ty_bool }
2990 pub fn type_is_self(ty: Ty) -> bool {
2992 ty_param(ref p) => p.space == subst::SelfSpace,
2997 fn type_is_slice(ty: Ty) -> bool {
2999 ty_ptr(mt) | ty_rptr(_, mt) => match mt.ty.sty {
3000 ty_vec(_, None) | ty_str => true,
3007 pub fn type_is_vec(ty: Ty) -> bool {
3010 ty_ptr(mt{ty, ..}) | ty_rptr(_, mt{ty, ..}) |
3011 ty_uniq(ty) => match ty.sty {
3012 ty_vec(_, None) => true,
3019 pub fn type_is_structural(ty: Ty) -> bool {
3021 ty_struct(..) | ty_tup(_) | ty_enum(..) |
3022 ty_vec(_, Some(_)) | ty_unboxed_closure(..) => true,
3023 _ => type_is_slice(ty) | type_is_trait(ty)
3027 pub fn type_is_simd(cx: &ctxt, ty: Ty) -> bool {
3029 ty_struct(did, _) => lookup_simd(cx, did),
3034 pub fn sequence_element_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
3036 ty_vec(ty, _) => ty,
3037 ty_str => mk_mach_uint(cx, ast::TyU8),
3038 ty_open(ty) => sequence_element_type(cx, ty),
3039 _ => cx.sess.bug(format!("sequence_element_type called on non-sequence value: {}",
3040 ty_to_string(cx, ty))[]),
3044 pub fn simd_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
3046 ty_struct(did, substs) => {
3047 let fields = lookup_struct_fields(cx, did);
3048 lookup_field_type(cx, did, fields[0].id, substs)
3050 _ => panic!("simd_type called on invalid type")
3054 pub fn simd_size(cx: &ctxt, ty: Ty) -> uint {
3056 ty_struct(did, _) => {
3057 let fields = lookup_struct_fields(cx, did);
3060 _ => panic!("simd_size called on invalid type")
3064 pub fn type_is_region_ptr(ty: Ty) -> bool {
3066 ty_rptr(..) => true,
3071 pub fn type_is_unsafe_ptr(ty: Ty) -> bool {
3073 ty_ptr(_) => return true,
3078 pub fn type_is_unique(ty: Ty) -> bool {
3080 ty_uniq(_) => match ty.sty {
3081 ty_trait(..) => false,
3089 A scalar type is one that denotes an atomic datum, with no sub-components.
3090 (A ty_ptr is scalar because it represents a non-managed pointer, so its
3091 contents are abstract to rustc.)
3093 pub fn type_is_scalar(ty: Ty) -> bool {
3095 ty_bool | ty_char | ty_int(_) | ty_float(_) | ty_uint(_) |
3096 ty_infer(IntVar(_)) | ty_infer(FloatVar(_)) |
3097 ty_bare_fn(..) | ty_ptr(_) => true,
3098 ty_tup(ref tys) if tys.is_empty() => true,
3103 /// Returns true if this type is a floating point type and false otherwise.
3104 pub fn type_is_floating_point(ty: Ty) -> bool {
3106 ty_float(_) => true,
3111 /// Type contents is how the type checker reasons about kinds.
3112 /// They track what kinds of things are found within a type. You can
3113 /// think of them as kind of an "anti-kind". They track the kinds of values
3114 /// and thinks that are contained in types. Having a larger contents for
3115 /// a type tends to rule that type *out* from various kinds. For example,
3116 /// a type that contains a reference is not sendable.
3118 /// The reason we compute type contents and not kinds is that it is
3119 /// easier for me (nmatsakis) to think about what is contained within
3120 /// a type than to think about what is *not* contained within a type.
3121 #[derive(Clone, Copy)]
3122 pub struct TypeContents {
3126 macro_rules! def_type_content_sets {
3127 (mod $mname:ident { $($name:ident = $bits:expr),+ }) => {
3128 #[allow(non_snake_case)]
3130 use middle::ty::TypeContents;
3132 #[allow(non_upper_case_globals)]
3133 pub const $name: TypeContents = TypeContents { bits: $bits };
3139 def_type_content_sets! {
3141 None = 0b0000_0000__0000_0000__0000,
3143 // Things that are interior to the value (first nibble):
3144 InteriorUnsized = 0b0000_0000__0000_0000__0001,
3145 InteriorUnsafe = 0b0000_0000__0000_0000__0010,
3146 InteriorParam = 0b0000_0000__0000_0000__0100,
3147 // InteriorAll = 0b00000000__00000000__1111,
3149 // Things that are owned by the value (second and third nibbles):
3150 OwnsOwned = 0b0000_0000__0000_0001__0000,
3151 OwnsDtor = 0b0000_0000__0000_0010__0000,
3152 OwnsManaged /* see [1] below */ = 0b0000_0000__0000_0100__0000,
3153 OwnsAll = 0b0000_0000__1111_1111__0000,
3155 // Things that are reachable by the value in any way (fourth nibble):
3156 ReachesBorrowed = 0b0000_0010__0000_0000__0000,
3157 // ReachesManaged /* see [1] below */ = 0b0000_0100__0000_0000__0000,
3158 ReachesMutable = 0b0000_1000__0000_0000__0000,
3159 ReachesFfiUnsafe = 0b0010_0000__0000_0000__0000,
3160 ReachesAll = 0b0011_1111__0000_0000__0000,
3162 // Things that mean drop glue is necessary
3163 NeedsDrop = 0b0000_0000__0000_0111__0000,
3165 // Things that prevent values from being considered sized
3166 Nonsized = 0b0000_0000__0000_0000__0001,
3168 // Bits to set when a managed value is encountered
3170 // [1] Do not set the bits TC::OwnsManaged or
3171 // TC::ReachesManaged directly, instead reference
3172 // TC::Managed to set them both at once.
3173 Managed = 0b0000_0100__0000_0100__0000,
3176 All = 0b1111_1111__1111_1111__1111
3181 pub fn when(&self, cond: bool) -> TypeContents {
3182 if cond {*self} else {TC::None}
3185 pub fn intersects(&self, tc: TypeContents) -> bool {
3186 (self.bits & tc.bits) != 0
3189 pub fn owns_managed(&self) -> bool {
3190 self.intersects(TC::OwnsManaged)
3193 pub fn owns_owned(&self) -> bool {
3194 self.intersects(TC::OwnsOwned)
3197 pub fn is_sized(&self, _: &ctxt) -> bool {
3198 !self.intersects(TC::Nonsized)
3201 pub fn interior_param(&self) -> bool {
3202 self.intersects(TC::InteriorParam)
3205 pub fn interior_unsafe(&self) -> bool {
3206 self.intersects(TC::InteriorUnsafe)
3209 pub fn interior_unsized(&self) -> bool {
3210 self.intersects(TC::InteriorUnsized)
3213 pub fn needs_drop(&self, _: &ctxt) -> bool {
3214 self.intersects(TC::NeedsDrop)
3217 /// Includes only those bits that still apply when indirected through a `Box` pointer
3218 pub fn owned_pointer(&self) -> TypeContents {
3220 *self & (TC::OwnsAll | TC::ReachesAll))
3223 /// Includes only those bits that still apply when indirected through a reference (`&`)
3224 pub fn reference(&self, bits: TypeContents) -> TypeContents {
3226 *self & TC::ReachesAll)
3229 /// Includes only those bits that still apply when indirected through a managed pointer (`@`)
3230 pub fn managed_pointer(&self) -> TypeContents {
3232 *self & TC::ReachesAll)
3235 /// Includes only those bits that still apply when indirected through an unsafe pointer (`*`)
3236 pub fn unsafe_pointer(&self) -> TypeContents {
3237 *self & TC::ReachesAll
3240 pub fn union<T, F>(v: &[T], mut f: F) -> TypeContents where
3241 F: FnMut(&T) -> TypeContents,
3243 v.iter().fold(TC::None, |tc, ty| tc | f(ty))
3246 pub fn has_dtor(&self) -> bool {
3247 self.intersects(TC::OwnsDtor)
3251 impl ops::BitOr for TypeContents {
3252 type Output = TypeContents;
3254 fn bitor(self, other: TypeContents) -> TypeContents {
3255 TypeContents {bits: self.bits | other.bits}
3259 impl ops::BitAnd for TypeContents {
3260 type Output = TypeContents;
3262 fn bitand(self, other: TypeContents) -> TypeContents {
3263 TypeContents {bits: self.bits & other.bits}
3267 impl ops::Sub for TypeContents {
3268 type Output = TypeContents;
3270 fn sub(self, other: TypeContents) -> TypeContents {
3271 TypeContents {bits: self.bits & !other.bits}
3275 impl fmt::Show for TypeContents {
3276 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
3277 write!(f, "TypeContents({:b})", self.bits)
3281 pub fn type_interior_is_unsafe<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
3282 type_contents(cx, ty).interior_unsafe()
3285 pub fn type_contents<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> TypeContents {
3286 return memoized(&cx.tc_cache, ty, |ty| {
3287 tc_ty(cx, ty, &mut FnvHashMap::new())
3290 fn tc_ty<'tcx>(cx: &ctxt<'tcx>,
3292 cache: &mut FnvHashMap<Ty<'tcx>, TypeContents>) -> TypeContents
3294 // Subtle: Note that we are *not* using cx.tc_cache here but rather a
3295 // private cache for this walk. This is needed in the case of cyclic
3298 // struct List { next: Box<Option<List>>, ... }
3300 // When computing the type contents of such a type, we wind up deeply
3301 // recursing as we go. So when we encounter the recursive reference
3302 // to List, we temporarily use TC::None as its contents. Later we'll
3303 // patch up the cache with the correct value, once we've computed it
3304 // (this is basically a co-inductive process, if that helps). So in
3305 // the end we'll compute TC::OwnsOwned, in this case.
3307 // The problem is, as we are doing the computation, we will also
3308 // compute an *intermediate* contents for, e.g., Option<List> of
3309 // TC::None. This is ok during the computation of List itself, but if
3310 // we stored this intermediate value into cx.tc_cache, then later
3311 // requests for the contents of Option<List> would also yield TC::None
3312 // which is incorrect. This value was computed based on the crutch
3313 // value for the type contents of list. The correct value is
3314 // TC::OwnsOwned. This manifested as issue #4821.
3315 match cache.get(&ty) {
3316 Some(tc) => { return *tc; }
3319 match cx.tc_cache.borrow().get(&ty) { // Must check both caches!
3320 Some(tc) => { return *tc; }
3323 cache.insert(ty, TC::None);
3325 let result = match ty.sty {
3326 // uint and int are ffi-unsafe
3327 ty_uint(ast::TyU) | ty_int(ast::TyI) => {
3328 TC::ReachesFfiUnsafe
3331 // Scalar and unique types are sendable, and durable
3332 ty_infer(ty::FreshIntTy(_)) |
3333 ty_bool | ty_int(_) | ty_uint(_) | ty_float(_) |
3334 ty_bare_fn(..) | ty::ty_char => {
3339 TC::ReachesFfiUnsafe | match typ.sty {
3340 ty_str => TC::OwnsOwned,
3341 _ => tc_ty(cx, typ, cache).owned_pointer(),
3345 ty_trait(box TyTrait { ref bounds, .. }) => {
3346 object_contents(bounds) | TC::ReachesFfiUnsafe | TC::Nonsized
3350 tc_ty(cx, mt.ty, cache).unsafe_pointer()
3353 ty_rptr(r, ref mt) => {
3354 TC::ReachesFfiUnsafe | match mt.ty.sty {
3355 ty_str => borrowed_contents(*r, ast::MutImmutable),
3356 ty_vec(..) => tc_ty(cx, mt.ty, cache).reference(borrowed_contents(*r,
3358 _ => tc_ty(cx, mt.ty, cache).reference(borrowed_contents(*r, mt.mutbl)),
3362 ty_vec(ty, Some(_)) => {
3363 tc_ty(cx, ty, cache)
3366 ty_vec(ty, None) => {
3367 tc_ty(cx, ty, cache) | TC::Nonsized
3369 ty_str => TC::Nonsized,
3371 ty_struct(did, substs) => {
3372 let flds = struct_fields(cx, did, substs);
3374 TypeContents::union(flds[],
3375 |f| tc_mt(cx, f.mt, cache));
3377 if !lookup_repr_hints(cx, did).contains(&attr::ReprExtern) {
3378 res = res | TC::ReachesFfiUnsafe;
3381 if ty::has_dtor(cx, did) {
3382 res = res | TC::OwnsDtor;
3384 apply_lang_items(cx, did, res)
3387 ty_unboxed_closure(did, r, substs) => {
3388 // FIXME(#14449): `borrowed_contents` below assumes `&mut`
3390 let param_env = ty::empty_parameter_environment(cx);
3391 let upvars = unboxed_closure_upvars(¶m_env, did, substs).unwrap();
3392 TypeContents::union(upvars.as_slice(),
3393 |f| tc_ty(cx, f.ty, cache))
3394 | borrowed_contents(*r, MutMutable)
3397 ty_tup(ref tys) => {
3398 TypeContents::union(tys[],
3399 |ty| tc_ty(cx, *ty, cache))
3402 ty_enum(did, substs) => {
3403 let variants = substd_enum_variants(cx, did, substs);
3405 TypeContents::union(variants[], |variant| {
3406 TypeContents::union(variant.args[],
3408 tc_ty(cx, *arg_ty, cache)
3412 if ty::has_dtor(cx, did) {
3413 res = res | TC::OwnsDtor;
3416 if variants.len() != 0 {
3417 let repr_hints = lookup_repr_hints(cx, did);
3418 if repr_hints.len() > 1 {
3419 // this is an error later on, but this type isn't safe
3420 res = res | TC::ReachesFfiUnsafe;
3423 match repr_hints.get(0) {
3424 Some(h) => if !h.is_ffi_safe() {
3425 res = res | TC::ReachesFfiUnsafe;
3429 res = res | TC::ReachesFfiUnsafe;
3431 // We allow ReprAny enums if they are eligible for
3432 // the nullable pointer optimization and the
3433 // contained type is an `extern fn`
3435 if variants.len() == 2 {
3436 let mut data_idx = 0;
3438 if variants[0].args.len() == 0 {
3442 if variants[data_idx].args.len() == 1 {
3443 match variants[data_idx].args[0].sty {
3444 ty_bare_fn(..) => { res = res - TC::ReachesFfiUnsafe; }
3454 apply_lang_items(cx, did, res)
3463 let result = tc_ty(cx, ty, cache);
3464 assert!(!result.is_sized(cx));
3465 result.unsafe_pointer() | TC::Nonsized
3470 cx.sess.bug("asked to compute contents of error type");
3474 cache.insert(ty, result);
3478 fn tc_mt<'tcx>(cx: &ctxt<'tcx>,
3480 cache: &mut FnvHashMap<Ty<'tcx>, TypeContents>) -> TypeContents
3482 let mc = TC::ReachesMutable.when(mt.mutbl == MutMutable);
3483 mc | tc_ty(cx, mt.ty, cache)
3486 fn apply_lang_items(cx: &ctxt, did: ast::DefId, tc: TypeContents)
3488 if Some(did) == cx.lang_items.managed_bound() {
3490 } else if Some(did) == cx.lang_items.unsafe_type() {
3491 tc | TC::InteriorUnsafe
3497 /// Type contents due to containing a reference with the region `region` and borrow kind `bk`
3498 fn borrowed_contents(region: ty::Region,
3499 mutbl: ast::Mutability)
3501 let b = match mutbl {
3502 ast::MutMutable => TC::ReachesMutable,
3503 ast::MutImmutable => TC::None,
3505 b | (TC::ReachesBorrowed).when(region != ty::ReStatic)
3508 fn object_contents(bounds: &ExistentialBounds) -> TypeContents {
3509 // These are the type contents of the (opaque) interior. We
3510 // make no assumptions (other than that it cannot have an
3511 // in-scope type parameter within, which makes no sense).
3512 let mut tc = TC::All - TC::InteriorParam;
3513 for bound in bounds.builtin_bounds.iter() {
3514 tc = tc - match bound {
3515 BoundSync | BoundSend | BoundCopy => TC::None,
3516 BoundSized => TC::Nonsized,
3523 fn type_impls_bound<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3524 cache: &RefCell<HashMap<Ty<'tcx>,bool>>,
3526 bound: ty::BuiltinBound,
3530 assert!(!ty::type_needs_infer(ty));
3532 if !type_has_params(ty) && !type_has_self(ty) {
3533 match cache.borrow().get(&ty) {
3536 debug!("type_impls_bound({}, {}) = {} (cached)",
3537 ty.repr(param_env.tcx),
3545 let infcx = infer::new_infer_ctxt(param_env.tcx);
3547 let is_impld = traits::type_known_to_meet_builtin_bound(&infcx, param_env, ty, bound, span);
3549 debug!("type_impls_bound({}, {}) = {}",
3550 ty.repr(param_env.tcx),
3554 if !type_has_params(ty) && !type_has_self(ty) {
3555 let old_value = cache.borrow_mut().insert(ty, is_impld);
3556 assert!(old_value.is_none());
3562 pub fn type_moves_by_default<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3567 let tcx = param_env.tcx;
3568 !type_impls_bound(param_env, &tcx.type_impls_copy_cache, ty, ty::BoundCopy, span)
3571 pub fn type_is_sized<'a,'tcx>(param_env: &ParameterEnvironment<'a,'tcx>,
3576 let tcx = param_env.tcx;
3577 type_impls_bound(param_env, &tcx.type_impls_sized_cache, ty, ty::BoundSized, span)
3580 pub fn is_ffi_safe<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> bool {
3581 !type_contents(cx, ty).intersects(TC::ReachesFfiUnsafe)
3584 // True if instantiating an instance of `r_ty` requires an instance of `r_ty`.
3585 pub fn is_instantiable<'tcx>(cx: &ctxt<'tcx>, r_ty: Ty<'tcx>) -> bool {
3586 fn type_requires<'tcx>(cx: &ctxt<'tcx>, seen: &mut Vec<DefId>,
3587 r_ty: Ty<'tcx>, ty: Ty<'tcx>) -> bool {
3588 debug!("type_requires({}, {})?",
3589 ::util::ppaux::ty_to_string(cx, r_ty),
3590 ::util::ppaux::ty_to_string(cx, ty));
3592 let r = r_ty == ty || subtypes_require(cx, seen, r_ty, ty);
3594 debug!("type_requires({}, {})? {}",
3595 ::util::ppaux::ty_to_string(cx, r_ty),
3596 ::util::ppaux::ty_to_string(cx, ty),
3601 fn subtypes_require<'tcx>(cx: &ctxt<'tcx>, seen: &mut Vec<DefId>,
3602 r_ty: Ty<'tcx>, ty: Ty<'tcx>) -> bool {
3603 debug!("subtypes_require({}, {})?",
3604 ::util::ppaux::ty_to_string(cx, r_ty),
3605 ::util::ppaux::ty_to_string(cx, ty));
3607 let r = match ty.sty {
3608 // fixed length vectors need special treatment compared to
3609 // normal vectors, since they don't necessarily have the
3610 // possibility to have length zero.
3611 ty_vec(_, Some(0)) => false, // don't need no contents
3612 ty_vec(ty, Some(_)) => type_requires(cx, seen, r_ty, ty),
3623 ty_vec(_, None) => {
3626 ty_uniq(typ) | ty_open(typ) => {
3627 type_requires(cx, seen, r_ty, typ)
3629 ty_rptr(_, ref mt) => {
3630 type_requires(cx, seen, r_ty, mt.ty)
3634 false // unsafe ptrs can always be NULL
3641 ty_struct(ref did, _) if seen.contains(did) => {
3645 ty_struct(did, substs) => {
3647 let fields = struct_fields(cx, did, substs);
3648 let r = fields.iter().any(|f| type_requires(cx, seen, r_ty, f.mt.ty));
3649 seen.pop().unwrap();
3655 ty_unboxed_closure(..) => {
3656 // this check is run on type definitions, so we don't expect to see
3657 // inference by-products or unboxed closure types
3658 cx.sess.bug(format!("requires check invoked on inapplicable type: {}", ty)[])
3662 ts.iter().any(|ty| type_requires(cx, seen, r_ty, *ty))
3665 ty_enum(ref did, _) if seen.contains(did) => {
3669 ty_enum(did, substs) => {
3671 let vs = enum_variants(cx, did);
3672 let r = !vs.is_empty() && vs.iter().all(|variant| {
3673 variant.args.iter().any(|aty| {
3674 let sty = aty.subst(cx, substs);
3675 type_requires(cx, seen, r_ty, sty)
3678 seen.pop().unwrap();
3683 debug!("subtypes_require({}, {})? {}",
3684 ::util::ppaux::ty_to_string(cx, r_ty),
3685 ::util::ppaux::ty_to_string(cx, ty),
3691 let mut seen = Vec::new();
3692 !subtypes_require(cx, &mut seen, r_ty, r_ty)
3695 /// Describes whether a type is representable. For types that are not
3696 /// representable, 'SelfRecursive' and 'ContainsRecursive' are used to
3697 /// distinguish between types that are recursive with themselves and types that
3698 /// contain a different recursive type. These cases can therefore be treated
3699 /// differently when reporting errors.
3701 /// The ordering of the cases is significant. They are sorted so that cmp::max
3702 /// will keep the "more erroneous" of two values.
3703 #[derive(Copy, PartialOrd, Ord, Eq, PartialEq, Show)]
3704 pub enum Representability {
3710 /// Check whether a type is representable. This means it cannot contain unboxed
3711 /// structural recursion. This check is needed for structs and enums.
3712 pub fn is_type_representable<'tcx>(cx: &ctxt<'tcx>, sp: Span, ty: Ty<'tcx>)
3713 -> Representability {
3715 // Iterate until something non-representable is found
3716 fn find_nonrepresentable<'tcx, It: Iterator<Item=Ty<'tcx>>>(cx: &ctxt<'tcx>, sp: Span,
3717 seen: &mut Vec<Ty<'tcx>>,
3719 -> Representability {
3720 iter.fold(Representable,
3721 |r, ty| cmp::max(r, is_type_structurally_recursive(cx, sp, seen, ty)))
3724 fn are_inner_types_recursive<'tcx>(cx: &ctxt<'tcx>, sp: Span,
3725 seen: &mut Vec<Ty<'tcx>>, ty: Ty<'tcx>)
3726 -> Representability {
3729 find_nonrepresentable(cx, sp, seen, ts.iter().map(|ty| *ty))
3731 // Fixed-length vectors.
3732 // FIXME(#11924) Behavior undecided for zero-length vectors.
3733 ty_vec(ty, Some(_)) => {
3734 is_type_structurally_recursive(cx, sp, seen, ty)
3736 ty_struct(did, substs) => {
3737 let fields = struct_fields(cx, did, substs);
3738 find_nonrepresentable(cx, sp, seen, fields.iter().map(|f| f.mt.ty))
3740 ty_enum(did, substs) => {
3741 let vs = enum_variants(cx, did);
3742 let iter = vs.iter()
3743 .flat_map(|variant| { variant.args.iter() })
3744 .map(|aty| { aty.subst_spanned(cx, substs, Some(sp)) });
3746 find_nonrepresentable(cx, sp, seen, iter)
3748 ty_unboxed_closure(..) => {
3749 // this check is run on type definitions, so we don't expect to see
3750 // unboxed closure types
3751 cx.sess.bug(format!("requires check invoked on inapplicable type: {}", ty)[])
3757 fn same_struct_or_enum_def_id(ty: Ty, did: DefId) -> bool {
3759 ty_struct(ty_did, _) | ty_enum(ty_did, _) => {
3766 fn same_type<'tcx>(a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
3767 match (&a.sty, &b.sty) {
3768 (&ty_struct(did_a, ref substs_a), &ty_struct(did_b, ref substs_b)) |
3769 (&ty_enum(did_a, ref substs_a), &ty_enum(did_b, ref substs_b)) => {
3774 let types_a = substs_a.types.get_slice(subst::TypeSpace);
3775 let types_b = substs_b.types.get_slice(subst::TypeSpace);
3777 let pairs = types_a.iter().zip(types_b.iter());
3779 pairs.all(|(&a, &b)| same_type(a, b))
3787 // Does the type `ty` directly (without indirection through a pointer)
3788 // contain any types on stack `seen`?
3789 fn is_type_structurally_recursive<'tcx>(cx: &ctxt<'tcx>, sp: Span,
3790 seen: &mut Vec<Ty<'tcx>>,
3791 ty: Ty<'tcx>) -> Representability {
3792 debug!("is_type_structurally_recursive: {}",
3793 ::util::ppaux::ty_to_string(cx, ty));
3796 ty_struct(did, _) | ty_enum(did, _) => {
3798 // Iterate through stack of previously seen types.
3799 let mut iter = seen.iter();
3801 // The first item in `seen` is the type we are actually curious about.
3802 // We want to return SelfRecursive if this type contains itself.
3803 // It is important that we DON'T take generic parameters into account
3804 // for this check, so that Bar<T> in this example counts as SelfRecursive:
3807 // struct Bar<T> { x: Bar<Foo> }
3810 Some(&seen_type) => {
3811 if same_struct_or_enum_def_id(seen_type, did) {
3812 debug!("SelfRecursive: {} contains {}",
3813 ::util::ppaux::ty_to_string(cx, seen_type),
3814 ::util::ppaux::ty_to_string(cx, ty));
3815 return SelfRecursive;
3821 // We also need to know whether the first item contains other types that
3822 // are structurally recursive. If we don't catch this case, we will recurse
3823 // infinitely for some inputs.
3825 // It is important that we DO take generic parameters into account here,
3826 // so that code like this is considered SelfRecursive, not ContainsRecursive:
3828 // struct Foo { Option<Option<Foo>> }
3830 for &seen_type in iter {
3831 if same_type(ty, seen_type) {
3832 debug!("ContainsRecursive: {} contains {}",
3833 ::util::ppaux::ty_to_string(cx, seen_type),
3834 ::util::ppaux::ty_to_string(cx, ty));
3835 return ContainsRecursive;
3840 // For structs and enums, track all previously seen types by pushing them
3841 // onto the 'seen' stack.
3843 let out = are_inner_types_recursive(cx, sp, seen, ty);
3848 // No need to push in other cases.
3849 are_inner_types_recursive(cx, sp, seen, ty)
3854 debug!("is_type_representable: {}",
3855 ::util::ppaux::ty_to_string(cx, ty));
3857 // To avoid a stack overflow when checking an enum variant or struct that
3858 // contains a different, structurally recursive type, maintain a stack
3859 // of seen types and check recursion for each of them (issues #3008, #3779).
3860 let mut seen: Vec<Ty> = Vec::new();
3861 let r = is_type_structurally_recursive(cx, sp, &mut seen, ty);
3862 debug!("is_type_representable: {} is {}",
3863 ::util::ppaux::ty_to_string(cx, ty), r);
3867 pub fn type_is_trait(ty: Ty) -> bool {
3868 type_trait_info(ty).is_some()
3871 pub fn type_trait_info<'tcx>(ty: Ty<'tcx>) -> Option<&'tcx TyTrait<'tcx>> {
3873 ty_uniq(ty) | ty_rptr(_, mt { ty, ..}) | ty_ptr(mt { ty, ..}) => match ty.sty {
3874 ty_trait(ref t) => Some(&**t),
3877 ty_trait(ref t) => Some(&**t),
3882 pub fn type_is_integral(ty: Ty) -> bool {
3884 ty_infer(IntVar(_)) | ty_int(_) | ty_uint(_) => true,
3889 pub fn type_is_fresh(ty: Ty) -> bool {
3891 ty_infer(FreshTy(_)) => true,
3892 ty_infer(FreshIntTy(_)) => true,
3897 pub fn type_is_uint(ty: Ty) -> bool {
3899 ty_infer(IntVar(_)) | ty_uint(ast::TyU) => true,
3904 pub fn type_is_char(ty: Ty) -> bool {
3911 pub fn type_is_bare_fn(ty: Ty) -> bool {
3913 ty_bare_fn(..) => true,
3918 pub fn type_is_bare_fn_item(ty: Ty) -> bool {
3920 ty_bare_fn(Some(_), _) => true,
3925 pub fn type_is_fp(ty: Ty) -> bool {
3927 ty_infer(FloatVar(_)) | ty_float(_) => true,
3932 pub fn type_is_numeric(ty: Ty) -> bool {
3933 return type_is_integral(ty) || type_is_fp(ty);
3936 pub fn type_is_signed(ty: Ty) -> bool {
3943 pub fn type_is_machine(ty: Ty) -> bool {
3945 ty_int(ast::TyI) | ty_uint(ast::TyU) => false,
3946 ty_int(..) | ty_uint(..) | ty_float(..) => true,
3951 // Whether a type is enum like, that is an enum type with only nullary
3953 pub fn type_is_c_like_enum(cx: &ctxt, ty: Ty) -> bool {
3955 ty_enum(did, _) => {
3956 let variants = enum_variants(cx, did);
3957 if variants.len() == 0 {
3960 variants.iter().all(|v| v.args.len() == 0)
3967 // Returns the type and mutability of *ty.
3969 // The parameter `explicit` indicates if this is an *explicit* dereference.
3970 // Some types---notably unsafe ptrs---can only be dereferenced explicitly.
3971 pub fn deref<'tcx>(ty: Ty<'tcx>, explicit: bool) -> Option<mt<'tcx>> {
3976 mutbl: ast::MutImmutable,
3979 ty_rptr(_, mt) => Some(mt),
3980 ty_ptr(mt) if explicit => Some(mt),
3985 pub fn close_type<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
3987 ty_open(ty) => mk_rptr(cx, cx.mk_region(ReStatic), mt {ty: ty, mutbl:ast::MutImmutable}),
3988 _ => cx.sess.bug(format!("Trying to close a non-open type {}",
3989 ty_to_string(cx, ty))[])
3993 pub fn type_content<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
3996 ty_rptr(_, mt) |ty_ptr(mt) => mt.ty,
4001 // Extract the unsized type in an open type (or just return ty if it is not open).
4002 pub fn unopen_type<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
4009 // Returns the type of ty[i]
4010 pub fn index<'tcx>(ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
4012 ty_vec(ty, _) => Some(ty),
4017 // Returns the type of elements contained within an 'array-like' type.
4018 // This is exactly the same as the above, except it supports strings,
4019 // which can't actually be indexed.
4020 pub fn array_element_ty<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Option<Ty<'tcx>> {
4022 ty_vec(ty, _) => Some(ty),
4023 ty_str => Some(tcx.types.u8),
4028 /// Returns the type of element at index `i` in tuple or tuple-like type `t`.
4029 /// For an enum `t`, `variant` is None only if `t` is a univariant enum.
4030 pub fn positional_element_ty<'tcx>(cx: &ctxt<'tcx>,
4033 variant: Option<ast::DefId>) -> Option<Ty<'tcx>> {
4035 match (&ty.sty, variant) {
4036 (&ty_tup(ref v), None) => v.get(i).map(|&t| t),
4039 (&ty_struct(def_id, substs), None) => lookup_struct_fields(cx, def_id)
4041 .map(|&t|lookup_item_type(cx, t.id).ty.subst(cx, substs)),
4043 (&ty_enum(def_id, substs), Some(variant_def_id)) => {
4044 let variant_info = enum_variant_with_id(cx, def_id, variant_def_id);
4045 variant_info.args.get(i).map(|t|t.subst(cx, substs))
4048 (&ty_enum(def_id, substs), None) => {
4049 assert!(enum_is_univariant(cx, def_id));
4050 let enum_variants = enum_variants(cx, def_id);
4051 let variant_info = &(*enum_variants)[0];
4052 variant_info.args.get(i).map(|t|t.subst(cx, substs))
4059 /// Returns the type of element at field `n` in struct or struct-like type `t`.
4060 /// For an enum `t`, `variant` must be some def id.
4061 pub fn named_element_ty<'tcx>(cx: &ctxt<'tcx>,
4064 variant: Option<ast::DefId>) -> Option<Ty<'tcx>> {
4066 match (&ty.sty, variant) {
4067 (&ty_struct(def_id, substs), None) => {
4068 let r = lookup_struct_fields(cx, def_id);
4069 r.iter().find(|f| f.name == n)
4070 .map(|&f| lookup_field_type(cx, def_id, f.id, substs))
4072 (&ty_enum(def_id, substs), Some(variant_def_id)) => {
4073 let variant_info = enum_variant_with_id(cx, def_id, variant_def_id);
4074 variant_info.arg_names.as_ref()
4075 .expect("must have struct enum variant if accessing a named fields")
4076 .iter().zip(variant_info.args.iter())
4077 .find(|&(ident, _)| ident.name == n)
4078 .map(|(_ident, arg_t)| arg_t.subst(cx, substs))
4084 pub fn node_id_to_trait_ref<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId)
4085 -> Rc<ty::TraitRef<'tcx>> {
4086 match cx.trait_refs.borrow().get(&id) {
4087 Some(ty) => ty.clone(),
4088 None => cx.sess.bug(
4089 format!("node_id_to_trait_ref: no trait ref for node `{}`",
4090 cx.map.node_to_string(id))[])
4094 pub fn try_node_id_to_type<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Option<Ty<'tcx>> {
4095 cx.node_types.borrow().get(&id).cloned()
4098 pub fn node_id_to_type<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Ty<'tcx> {
4099 match try_node_id_to_type(cx, id) {
4101 None => cx.sess.bug(
4102 format!("node_id_to_type: no type for node `{}`",
4103 cx.map.node_to_string(id))[])
4107 pub fn node_id_to_type_opt<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> Option<Ty<'tcx>> {
4108 match cx.node_types.borrow().get(&id) {
4109 Some(&ty) => Some(ty),
4114 pub fn node_id_item_substs<'tcx>(cx: &ctxt<'tcx>, id: ast::NodeId) -> ItemSubsts<'tcx> {
4115 match cx.item_substs.borrow().get(&id) {
4116 None => ItemSubsts::empty(),
4117 Some(ts) => ts.clone(),
4121 pub fn fn_is_variadic(fty: Ty) -> bool {
4123 ty_bare_fn(_, ref f) => f.sig.0.variadic,
4125 panic!("fn_is_variadic() called on non-fn type: {}", s)
4130 pub fn ty_fn_sig<'tcx>(fty: Ty<'tcx>) -> &'tcx PolyFnSig<'tcx> {
4132 ty_bare_fn(_, ref f) => &f.sig,
4134 panic!("ty_fn_sig() called on non-fn type: {}", s)
4139 /// Returns the ABI of the given function.
4140 pub fn ty_fn_abi(fty: Ty) -> abi::Abi {
4142 ty_bare_fn(_, ref f) => f.abi,
4143 _ => panic!("ty_fn_abi() called on non-fn type"),
4147 // Type accessors for substructures of types
4148 pub fn ty_fn_args<'tcx>(fty: Ty<'tcx>) -> &'tcx [Ty<'tcx>] {
4149 ty_fn_sig(fty).0.inputs.as_slice()
4152 pub fn ty_closure_store(fty: Ty) -> TraitStore {
4154 ty_unboxed_closure(..) => {
4155 // Close enough for the purposes of all the callers of this
4156 // function (which is soon to be deprecated anyhow).
4160 panic!("ty_closure_store() called on non-closure type: {}", s)
4165 pub fn ty_fn_ret<'tcx>(fty: Ty<'tcx>) -> FnOutput<'tcx> {
4167 ty_bare_fn(_, ref f) => f.sig.0.output,
4169 panic!("ty_fn_ret() called on non-fn type: {}", s)
4174 pub fn is_fn_ty(fty: Ty) -> bool {
4176 ty_bare_fn(..) => true,
4181 pub fn ty_region(tcx: &ctxt,
4185 ty_rptr(r, _) => *r,
4189 format!("ty_region() invoked on an inappropriate ty: {}",
4195 pub fn free_region_from_def(free_id: ast::NodeId, def: &RegionParameterDef)
4198 ty::ReFree(ty::FreeRegion { scope: region::CodeExtent::from_node_id(free_id),
4199 bound_region: ty::BrNamed(def.def_id,
4203 // Returns the type of a pattern as a monotype. Like @expr_ty, this function
4204 // doesn't provide type parameter substitutions.
4205 pub fn pat_ty<'tcx>(cx: &ctxt<'tcx>, pat: &ast::Pat) -> Ty<'tcx> {
4206 return node_id_to_type(cx, pat.id);
4210 // Returns the type of an expression as a monotype.
4212 // NB (1): This is the PRE-ADJUSTMENT TYPE for the expression. That is, in
4213 // some cases, we insert `AutoAdjustment` annotations such as auto-deref or
4214 // auto-ref. The type returned by this function does not consider such
4215 // adjustments. See `expr_ty_adjusted()` instead.
4217 // NB (2): This type doesn't provide type parameter substitutions; e.g. if you
4218 // ask for the type of "id" in "id(3)", it will return "fn(&int) -> int"
4219 // instead of "fn(ty) -> T with T = int".
4220 pub fn expr_ty<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Ty<'tcx> {
4221 return node_id_to_type(cx, expr.id);
4224 pub fn expr_ty_opt<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Option<Ty<'tcx>> {
4225 return node_id_to_type_opt(cx, expr.id);
4228 /// Returns the type of `expr`, considering any `AutoAdjustment`
4229 /// entry recorded for that expression.
4231 /// It would almost certainly be better to store the adjusted ty in with
4232 /// the `AutoAdjustment`, but I opted not to do this because it would
4233 /// require serializing and deserializing the type and, although that's not
4234 /// hard to do, I just hate that code so much I didn't want to touch it
4235 /// unless it was to fix it properly, which seemed a distraction from the
4236 /// task at hand! -nmatsakis
4237 pub fn expr_ty_adjusted<'tcx>(cx: &ctxt<'tcx>, expr: &ast::Expr) -> Ty<'tcx> {
4238 adjust_ty(cx, expr.span, expr.id, expr_ty(cx, expr),
4239 cx.adjustments.borrow().get(&expr.id),
4240 |method_call| cx.method_map.borrow().get(&method_call).map(|method| method.ty))
4243 pub fn expr_span(cx: &ctxt, id: NodeId) -> Span {
4244 match cx.map.find(id) {
4245 Some(ast_map::NodeExpr(e)) => {
4249 cx.sess.bug(format!("Node id {} is not an expr: {}",
4254 cx.sess.bug(format!("Node id {} is not present \
4255 in the node map", id)[]);
4260 pub fn local_var_name_str(cx: &ctxt, id: NodeId) -> InternedString {
4261 match cx.map.find(id) {
4262 Some(ast_map::NodeLocal(pat)) => {
4264 ast::PatIdent(_, ref path1, _) => {
4265 token::get_ident(path1.node)
4269 format!("Variable id {} maps to {}, not local",
4276 cx.sess.bug(format!("Variable id {} maps to {}, not local",
4283 /// See `expr_ty_adjusted`
4284 pub fn adjust_ty<'tcx, F>(cx: &ctxt<'tcx>,
4286 expr_id: ast::NodeId,
4287 unadjusted_ty: Ty<'tcx>,
4288 adjustment: Option<&AutoAdjustment<'tcx>>,
4291 F: FnMut(MethodCall) -> Option<Ty<'tcx>>,
4293 if let ty_err = unadjusted_ty.sty {
4294 return unadjusted_ty;
4297 return match adjustment {
4298 Some(adjustment) => {
4300 AdjustReifyFnPointer(_) => {
4301 match unadjusted_ty.sty {
4302 ty::ty_bare_fn(Some(_), b) => {
4303 ty::mk_bare_fn(cx, None, b)
4307 format!("AdjustReifyFnPointer adjustment on non-fn-item: \
4314 AdjustDerefRef(ref adj) => {
4315 let mut adjusted_ty = unadjusted_ty;
4317 if !ty::type_is_error(adjusted_ty) {
4318 for i in range(0, adj.autoderefs) {
4319 let method_call = MethodCall::autoderef(expr_id, i);
4320 match method_type(method_call) {
4321 Some(method_ty) => {
4322 if let ty::FnConverging(result_type) = ty_fn_ret(method_ty) {
4323 adjusted_ty = result_type;
4328 match deref(adjusted_ty, true) {
4329 Some(mt) => { adjusted_ty = mt.ty; }
4333 format!("the {}th autoderef failed: \
4336 ty_to_string(cx, adjusted_ty))
4343 adjust_ty_for_autoref(cx, span, adjusted_ty, adj.autoref.as_ref())
4347 None => unadjusted_ty
4351 pub fn adjust_ty_for_autoref<'tcx>(cx: &ctxt<'tcx>,
4354 autoref: Option<&AutoRef<'tcx>>)
4360 Some(&AutoPtr(r, m, ref a)) => {
4361 let adjusted_ty = match a {
4362 &Some(box ref a) => adjust_ty_for_autoref(cx, span, ty, Some(a)),
4365 mk_rptr(cx, cx.mk_region(r), mt {
4371 Some(&AutoUnsafe(m, ref a)) => {
4372 let adjusted_ty = match a {
4373 &Some(box ref a) => adjust_ty_for_autoref(cx, span, ty, Some(a)),
4376 mk_ptr(cx, mt {ty: adjusted_ty, mutbl: m})
4379 Some(&AutoUnsize(ref k)) => unsize_ty(cx, ty, k, span),
4381 Some(&AutoUnsizeUniq(ref k)) => ty::mk_uniq(cx, unsize_ty(cx, ty, k, span)),
4385 // Take a sized type and a sizing adjustment and produce an unsized version of
4387 pub fn unsize_ty<'tcx>(cx: &ctxt<'tcx>,
4389 kind: &UnsizeKind<'tcx>,
4393 &UnsizeLength(len) => match ty.sty {
4394 ty_vec(ty, Some(n)) => {
4396 mk_vec(cx, ty, None)
4398 _ => cx.sess.span_bug(span,
4399 format!("UnsizeLength with bad sty: {}",
4400 ty_to_string(cx, ty))[])
4402 &UnsizeStruct(box ref k, tp_index) => match ty.sty {
4403 ty_struct(did, substs) => {
4404 let ty_substs = substs.types.get_slice(subst::TypeSpace);
4405 let new_ty = unsize_ty(cx, ty_substs[tp_index], k, span);
4406 let mut unsized_substs = substs.clone();
4407 unsized_substs.types.get_mut_slice(subst::TypeSpace)[tp_index] = new_ty;
4408 mk_struct(cx, did, cx.mk_substs(unsized_substs))
4410 _ => cx.sess.span_bug(span,
4411 format!("UnsizeStruct with bad sty: {}",
4412 ty_to_string(cx, ty))[])
4414 &UnsizeVtable(TyTrait { ref principal, ref bounds }, _) => {
4415 mk_trait(cx, principal.clone(), bounds.clone())
4420 pub fn resolve_expr(tcx: &ctxt, expr: &ast::Expr) -> def::Def {
4421 match tcx.def_map.borrow().get(&expr.id) {
4424 tcx.sess.span_bug(expr.span, format!(
4425 "no def-map entry for expr {}", expr.id)[]);
4430 pub fn expr_is_lval(tcx: &ctxt, e: &ast::Expr) -> bool {
4431 match expr_kind(tcx, e) {
4433 RvalueDpsExpr | RvalueDatumExpr | RvalueStmtExpr => false
4437 /// We categorize expressions into three kinds. The distinction between
4438 /// lvalue/rvalue is fundamental to the language. The distinction between the
4439 /// two kinds of rvalues is an artifact of trans which reflects how we will
4440 /// generate code for that kind of expression. See trans/expr.rs for more
4450 pub fn expr_kind(tcx: &ctxt, expr: &ast::Expr) -> ExprKind {
4451 if tcx.method_map.borrow().contains_key(&MethodCall::expr(expr.id)) {
4452 // Overloaded operations are generally calls, and hence they are
4453 // generated via DPS, but there are a few exceptions:
4454 return match expr.node {
4455 // `a += b` has a unit result.
4456 ast::ExprAssignOp(..) => RvalueStmtExpr,
4458 // the deref method invoked for `*a` always yields an `&T`
4459 ast::ExprUnary(ast::UnDeref, _) => LvalueExpr,
4461 // the index method invoked for `a[i]` always yields an `&T`
4462 ast::ExprIndex(..) => LvalueExpr,
4464 // `for` loops are statements
4465 ast::ExprForLoop(..) => RvalueStmtExpr,
4467 // in the general case, result could be any type, use DPS
4473 ast::ExprPath(..) => {
4474 match resolve_expr(tcx, expr) {
4475 def::DefVariant(tid, vid, _) => {
4476 let variant_info = enum_variant_with_id(tcx, tid, vid);
4477 if variant_info.args.len() > 0u {
4486 def::DefStruct(_) => {
4487 match tcx.node_types.borrow().get(&expr.id) {
4488 Some(ty) => match ty.sty {
4489 ty_bare_fn(..) => RvalueDatumExpr,
4492 // See ExprCast below for why types might be missing.
4493 None => RvalueDatumExpr
4497 // Special case: A unit like struct's constructor must be called without () at the
4498 // end (like `UnitStruct`) which means this is an ExprPath to a DefFn. But in case
4499 // of unit structs this is should not be interpreted as function pointer but as
4500 // call to the constructor.
4501 def::DefFn(_, true) => RvalueDpsExpr,
4503 // Fn pointers are just scalar values.
4504 def::DefFn(..) | def::DefStaticMethod(..) | def::DefMethod(..) => RvalueDatumExpr,
4506 // Note: there is actually a good case to be made that
4507 // DefArg's, particularly those of immediate type, ought to
4508 // considered rvalues.
4509 def::DefStatic(..) |
4511 def::DefLocal(..) => LvalueExpr,
4513 def::DefConst(..) => RvalueDatumExpr,
4518 format!("uncategorized def for expr {}: {}",
4525 ast::ExprUnary(ast::UnDeref, _) |
4526 ast::ExprField(..) |
4527 ast::ExprTupField(..) |
4528 ast::ExprIndex(..) => {
4533 ast::ExprMethodCall(..) |
4534 ast::ExprStruct(..) |
4535 ast::ExprRange(..) |
4538 ast::ExprMatch(..) |
4539 ast::ExprClosure(..) |
4540 ast::ExprBlock(..) |
4541 ast::ExprRepeat(..) |
4542 ast::ExprVec(..) => {
4546 ast::ExprIfLet(..) => {
4547 tcx.sess.span_bug(expr.span, "non-desugared ExprIfLet");
4549 ast::ExprWhileLet(..) => {
4550 tcx.sess.span_bug(expr.span, "non-desugared ExprWhileLet");
4553 ast::ExprLit(ref lit) if lit_is_str(&**lit) => {
4557 ast::ExprCast(..) => {
4558 match tcx.node_types.borrow().get(&expr.id) {
4560 if type_is_trait(ty) {
4567 // Technically, it should not happen that the expr is not
4568 // present within the table. However, it DOES happen
4569 // during type check, because the final types from the
4570 // expressions are not yet recorded in the tcx. At that
4571 // time, though, we are only interested in knowing lvalue
4572 // vs rvalue. It would be better to base this decision on
4573 // the AST type in cast node---but (at the time of this
4574 // writing) it's not easy to distinguish casts to traits
4575 // from other casts based on the AST. This should be
4576 // easier in the future, when casts to traits
4577 // would like @Foo, Box<Foo>, or &Foo.
4583 ast::ExprBreak(..) |
4584 ast::ExprAgain(..) |
4586 ast::ExprWhile(..) |
4588 ast::ExprAssign(..) |
4589 ast::ExprInlineAsm(..) |
4590 ast::ExprAssignOp(..) |
4591 ast::ExprForLoop(..) => {
4595 ast::ExprLit(_) | // Note: LitStr is carved out above
4596 ast::ExprUnary(..) |
4597 ast::ExprBox(None, _) |
4598 ast::ExprAddrOf(..) |
4599 ast::ExprBinary(..) => {
4603 ast::ExprBox(Some(ref place), _) => {
4604 // Special case `Box<T>` for now:
4605 let definition = match tcx.def_map.borrow().get(&place.id) {
4607 None => panic!("no def for place"),
4609 let def_id = definition.def_id();
4610 if tcx.lang_items.exchange_heap() == Some(def_id) {
4617 ast::ExprParen(ref e) => expr_kind(tcx, &**e),
4619 ast::ExprMac(..) => {
4622 "macro expression remains after expansion");
4627 pub fn stmt_node_id(s: &ast::Stmt) -> ast::NodeId {
4629 ast::StmtDecl(_, id) | StmtExpr(_, id) | StmtSemi(_, id) => {
4632 ast::StmtMac(..) => panic!("unexpanded macro in trans")
4636 pub fn field_idx_strict(tcx: &ctxt, name: ast::Name, fields: &[field])
4639 for f in fields.iter() { if f.name == name { return i; } i += 1u; }
4640 tcx.sess.bug(format!(
4641 "no field named `{}` found in the list of fields `{}`",
4642 token::get_name(name),
4644 .map(|f| token::get_name(f.name).get().to_string())
4645 .collect::<Vec<String>>())[]);
4648 pub fn impl_or_trait_item_idx(id: ast::Name, trait_items: &[ImplOrTraitItem])
4650 trait_items.iter().position(|m| m.name() == id)
4653 pub fn ty_sort_string<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> String {
4655 ty_bool | ty_char | ty_int(_) |
4656 ty_uint(_) | ty_float(_) | ty_str => {
4657 ::util::ppaux::ty_to_string(cx, ty)
4659 ty_tup(ref tys) if tys.is_empty() => ::util::ppaux::ty_to_string(cx, ty),
4661 ty_enum(id, _) => format!("enum {}", item_path_str(cx, id)),
4662 ty_uniq(_) => "box".to_string(),
4663 ty_vec(_, Some(n)) => format!("array of {} elements", n),
4664 ty_vec(_, None) => "slice".to_string(),
4665 ty_ptr(_) => "*-ptr".to_string(),
4666 ty_rptr(_, _) => "&-ptr".to_string(),
4667 ty_bare_fn(Some(_), _) => format!("fn item"),
4668 ty_bare_fn(None, _) => "fn pointer".to_string(),
4669 ty_trait(ref inner) => {
4670 format!("trait {}", item_path_str(cx, inner.principal_def_id()))
4672 ty_struct(id, _) => {
4673 format!("struct {}", item_path_str(cx, id))
4675 ty_unboxed_closure(..) => "closure".to_string(),
4676 ty_tup(_) => "tuple".to_string(),
4677 ty_infer(TyVar(_)) => "inferred type".to_string(),
4678 ty_infer(IntVar(_)) => "integral variable".to_string(),
4679 ty_infer(FloatVar(_)) => "floating-point variable".to_string(),
4680 ty_infer(FreshTy(_)) => "skolemized type".to_string(),
4681 ty_infer(FreshIntTy(_)) => "skolemized integral type".to_string(),
4682 ty_projection(_) => "associated type".to_string(),
4683 ty_param(ref p) => {
4684 if p.space == subst::SelfSpace {
4687 "type parameter".to_string()
4690 ty_err => "type error".to_string(),
4691 ty_open(_) => "opened DST".to_string(),
4695 impl<'tcx> Repr<'tcx> for ty::type_err<'tcx> {
4696 fn repr(&self, tcx: &ty::ctxt<'tcx>) -> String {
4697 ty::type_err_to_str(tcx, self)
4701 /// Explains the source of a type err in a short, human readable way. This is meant to be placed
4702 /// in parentheses after some larger message. You should also invoke `note_and_explain_type_err()`
4703 /// afterwards to present additional details, particularly when it comes to lifetime-related
4705 pub fn type_err_to_str<'tcx>(cx: &ctxt<'tcx>, err: &type_err<'tcx>) -> String {
4706 fn tstore_to_closure(s: &TraitStore) -> String {
4708 &UniqTraitStore => "proc".to_string(),
4709 &RegionTraitStore(..) => "closure".to_string()
4714 terr_cyclic_ty => "cyclic type of infinite size".to_string(),
4715 terr_mismatch => "types differ".to_string(),
4716 terr_unsafety_mismatch(values) => {
4717 format!("expected {} fn, found {} fn",
4718 values.expected.to_string(),
4719 values.found.to_string())
4721 terr_abi_mismatch(values) => {
4722 format!("expected {} fn, found {} fn",
4723 values.expected.to_string(),
4724 values.found.to_string())
4726 terr_onceness_mismatch(values) => {
4727 format!("expected {} fn, found {} fn",
4728 values.expected.to_string(),
4729 values.found.to_string())
4731 terr_sigil_mismatch(values) => {
4732 format!("expected {}, found {}",
4733 tstore_to_closure(&values.expected),
4734 tstore_to_closure(&values.found))
4736 terr_mutability => "values differ in mutability".to_string(),
4737 terr_box_mutability => {
4738 "boxed values differ in mutability".to_string()
4740 terr_vec_mutability => "vectors differ in mutability".to_string(),
4741 terr_ptr_mutability => "pointers differ in mutability".to_string(),
4742 terr_ref_mutability => "references differ in mutability".to_string(),
4743 terr_ty_param_size(values) => {
4744 format!("expected a type with {} type params, \
4745 found one with {} type params",
4749 terr_fixed_array_size(values) => {
4750 format!("expected an array with a fixed size of {} elements, \
4751 found one with {} elements",
4755 terr_tuple_size(values) => {
4756 format!("expected a tuple with {} elements, \
4757 found one with {} elements",
4762 "incorrect number of function parameters".to_string()
4764 terr_regions_does_not_outlive(..) => {
4765 "lifetime mismatch".to_string()
4767 terr_regions_not_same(..) => {
4768 "lifetimes are not the same".to_string()
4770 terr_regions_no_overlap(..) => {
4771 "lifetimes do not intersect".to_string()
4773 terr_regions_insufficiently_polymorphic(br, _) => {
4774 format!("expected bound lifetime parameter {}, \
4775 found concrete lifetime",
4776 bound_region_ptr_to_string(cx, br))
4778 terr_regions_overly_polymorphic(br, _) => {
4779 format!("expected concrete lifetime, \
4780 found bound lifetime parameter {}",
4781 bound_region_ptr_to_string(cx, br))
4783 terr_trait_stores_differ(_, ref values) => {
4784 format!("trait storage differs: expected `{}`, found `{}`",
4785 trait_store_to_string(cx, (*values).expected),
4786 trait_store_to_string(cx, (*values).found))
4788 terr_sorts(values) => {
4789 // A naive approach to making sure that we're not reporting silly errors such as:
4790 // (expected closure, found closure).
4791 let expected_str = ty_sort_string(cx, values.expected);
4792 let found_str = ty_sort_string(cx, values.found);
4793 if expected_str == found_str {
4794 format!("expected {}, found a different {}", expected_str, found_str)
4796 format!("expected {}, found {}", expected_str, found_str)
4799 terr_traits(values) => {
4800 format!("expected trait `{}`, found trait `{}`",
4801 item_path_str(cx, values.expected),
4802 item_path_str(cx, values.found))
4804 terr_builtin_bounds(values) => {
4805 if values.expected.is_empty() {
4806 format!("expected no bounds, found `{}`",
4807 values.found.user_string(cx))
4808 } else if values.found.is_empty() {
4809 format!("expected bounds `{}`, found no bounds",
4810 values.expected.user_string(cx))
4812 format!("expected bounds `{}`, found bounds `{}`",
4813 values.expected.user_string(cx),
4814 values.found.user_string(cx))
4817 terr_integer_as_char => {
4818 "expected an integral type, found `char`".to_string()
4820 terr_int_mismatch(ref values) => {
4821 format!("expected `{}`, found `{}`",
4822 values.expected.to_string(),
4823 values.found.to_string())
4825 terr_float_mismatch(ref values) => {
4826 format!("expected `{}`, found `{}`",
4827 values.expected.to_string(),
4828 values.found.to_string())
4830 terr_variadic_mismatch(ref values) => {
4831 format!("expected {} fn, found {} function",
4832 if values.expected { "variadic" } else { "non-variadic" },
4833 if values.found { "variadic" } else { "non-variadic" })
4835 terr_convergence_mismatch(ref values) => {
4836 format!("expected {} fn, found {} function",
4837 if values.expected { "converging" } else { "diverging" },
4838 if values.found { "converging" } else { "diverging" })
4840 terr_projection_name_mismatched(ref values) => {
4841 format!("expected {}, found {}",
4842 token::get_name(values.expected),
4843 token::get_name(values.found))
4845 terr_projection_bounds_length(ref values) => {
4846 format!("expected {} associated type bindings, found {}",
4853 pub fn note_and_explain_type_err(cx: &ctxt, err: &type_err) {
4855 terr_regions_does_not_outlive(subregion, superregion) => {
4856 note_and_explain_region(cx, "", subregion, "...");
4857 note_and_explain_region(cx, "...does not necessarily outlive ",
4860 terr_regions_not_same(region1, region2) => {
4861 note_and_explain_region(cx, "", region1, "...");
4862 note_and_explain_region(cx, "...is not the same lifetime as ",
4865 terr_regions_no_overlap(region1, region2) => {
4866 note_and_explain_region(cx, "", region1, "...");
4867 note_and_explain_region(cx, "...does not overlap ",
4870 terr_regions_insufficiently_polymorphic(_, conc_region) => {
4871 note_and_explain_region(cx,
4872 "concrete lifetime that was found is ",
4875 terr_regions_overly_polymorphic(_, ty::ReInfer(ty::ReVar(_))) => {
4876 // don't bother to print out the message below for
4877 // inference variables, it's not very illuminating.
4879 terr_regions_overly_polymorphic(_, conc_region) => {
4880 note_and_explain_region(cx,
4881 "expected concrete lifetime is ",
4888 pub fn provided_source(cx: &ctxt, id: ast::DefId) -> Option<ast::DefId> {
4889 cx.provided_method_sources.borrow().get(&id).map(|x| *x)
4892 pub fn provided_trait_methods<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
4893 -> Vec<Rc<Method<'tcx>>> {
4895 match cx.map.find(id.node) {
4896 Some(ast_map::NodeItem(item)) => {
4898 ItemTrait(_, _, _, ref ms) => {
4900 ast_util::split_trait_methods(ms[]);
4903 match impl_or_trait_item(
4905 ast_util::local_def(m.id)) {
4906 MethodTraitItem(m) => m,
4907 TypeTraitItem(_) => {
4908 cx.sess.bug("provided_trait_methods(): \
4909 split_trait_methods() put \
4910 associated types in the \
4911 provided method bucket?!")
4917 cx.sess.bug(format!("provided_trait_methods: `{}` is \
4924 cx.sess.bug(format!("provided_trait_methods: `{}` is not a \
4930 csearch::get_provided_trait_methods(cx, id)
4934 /// Helper for looking things up in the various maps that are populated during
4935 /// typeck::collect (e.g., `cx.impl_or_trait_items`, `cx.tcache`, etc). All of
4936 /// these share the pattern that if the id is local, it should have been loaded
4937 /// into the map by the `typeck::collect` phase. If the def-id is external,
4938 /// then we have to go consult the crate loading code (and cache the result for
4940 fn lookup_locally_or_in_crate_store<V, F>(descr: &str,
4942 map: &mut DefIdMap<V>,
4943 load_external: F) -> V where
4947 match map.get(&def_id).cloned() {
4948 Some(v) => { return v; }
4952 if def_id.krate == ast::LOCAL_CRATE {
4953 panic!("No def'n found for {} in tcx.{}", def_id, descr);
4955 let v = load_external();
4956 map.insert(def_id, v.clone());
4960 pub fn trait_item<'tcx>(cx: &ctxt<'tcx>, trait_did: ast::DefId, idx: uint)
4961 -> ImplOrTraitItem<'tcx> {
4962 let method_def_id = (*ty::trait_item_def_ids(cx, trait_did))[idx].def_id();
4963 impl_or_trait_item(cx, method_def_id)
4966 pub fn trait_items<'tcx>(cx: &ctxt<'tcx>, trait_did: ast::DefId)
4967 -> Rc<Vec<ImplOrTraitItem<'tcx>>> {
4968 let mut trait_items = cx.trait_items_cache.borrow_mut();
4969 match trait_items.get(&trait_did).cloned() {
4970 Some(trait_items) => trait_items,
4972 let def_ids = ty::trait_item_def_ids(cx, trait_did);
4973 let items: Rc<Vec<ImplOrTraitItem>> =
4974 Rc::new(def_ids.iter()
4975 .map(|d| impl_or_trait_item(cx, d.def_id()))
4977 trait_items.insert(trait_did, items.clone());
4983 pub fn impl_or_trait_item<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
4984 -> ImplOrTraitItem<'tcx> {
4985 lookup_locally_or_in_crate_store("impl_or_trait_items",
4987 &mut *cx.impl_or_trait_items
4990 csearch::get_impl_or_trait_item(cx, id)
4994 /// Returns true if the given ID refers to an associated type and false if it
4995 /// refers to anything else.
4996 pub fn is_associated_type(cx: &ctxt, id: ast::DefId) -> bool {
4997 memoized(&cx.associated_types, id, |id: ast::DefId| {
4998 if id.krate == ast::LOCAL_CRATE {
4999 match cx.impl_or_trait_items.borrow().get(&id) {
5002 TypeTraitItem(_) => true,
5003 MethodTraitItem(_) => false,
5009 csearch::is_associated_type(&cx.sess.cstore, id)
5014 /// Returns the parameter index that the given associated type corresponds to.
5015 pub fn associated_type_parameter_index(cx: &ctxt,
5016 trait_def: &TraitDef,
5017 associated_type_id: ast::DefId)
5019 for type_parameter_def in trait_def.generics.types.iter() {
5020 if type_parameter_def.def_id == associated_type_id {
5021 return type_parameter_def.index as uint
5024 cx.sess.bug("couldn't find associated type parameter index")
5027 #[derive(Copy, PartialEq, Eq)]
5028 pub struct AssociatedTypeInfo {
5029 pub def_id: ast::DefId,
5031 pub name: ast::Name,
5034 impl PartialOrd for AssociatedTypeInfo {
5035 fn partial_cmp(&self, other: &AssociatedTypeInfo) -> Option<Ordering> {
5036 Some(self.index.cmp(&other.index))
5040 impl Ord for AssociatedTypeInfo {
5041 fn cmp(&self, other: &AssociatedTypeInfo) -> Ordering {
5042 self.index.cmp(&other.index)
5046 pub fn trait_item_def_ids(cx: &ctxt, id: ast::DefId)
5047 -> Rc<Vec<ImplOrTraitItemId>> {
5048 lookup_locally_or_in_crate_store("trait_item_def_ids",
5050 &mut *cx.trait_item_def_ids.borrow_mut(),
5052 Rc::new(csearch::get_trait_item_def_ids(&cx.sess.cstore, id))
5056 pub fn impl_trait_ref<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5057 -> Option<Rc<TraitRef<'tcx>>> {
5058 memoized(&cx.impl_trait_cache, id, |id: ast::DefId| {
5059 if id.krate == ast::LOCAL_CRATE {
5060 debug!("(impl_trait_ref) searching for trait impl {}", id);
5061 match cx.map.find(id.node) {
5062 Some(ast_map::NodeItem(item)) => {
5064 ast::ItemImpl(_, _, _, ref opt_trait, _, _) => {
5067 let trait_ref = ty::node_id_to_trait_ref(cx, t.ref_id);
5079 csearch::get_impl_trait(cx, id)
5084 pub fn trait_ref_to_def_id(tcx: &ctxt, tr: &ast::TraitRef) -> ast::DefId {
5085 let def = *tcx.def_map.borrow()
5087 .expect("no def-map entry for trait");
5091 pub fn try_add_builtin_trait(
5093 trait_def_id: ast::DefId,
5094 builtin_bounds: &mut EnumSet<BuiltinBound>)
5097 //! Checks whether `trait_ref` refers to one of the builtin
5098 //! traits, like `Send`, and adds the corresponding
5099 //! bound to the set `builtin_bounds` if so. Returns true if `trait_ref`
5100 //! is a builtin trait.
5102 match tcx.lang_items.to_builtin_kind(trait_def_id) {
5103 Some(bound) => { builtin_bounds.insert(bound); true }
5108 pub fn ty_to_def_id(ty: Ty) -> Option<ast::DefId> {
5111 Some(tt.principal_def_id()),
5114 ty_unboxed_closure(id, _, _) =>
5123 pub struct VariantInfo<'tcx> {
5124 pub args: Vec<Ty<'tcx>>,
5125 pub arg_names: Option<Vec<ast::Ident>>,
5126 pub ctor_ty: Option<Ty<'tcx>>,
5127 pub name: ast::Name,
5133 impl<'tcx> VariantInfo<'tcx> {
5135 /// Creates a new VariantInfo from the corresponding ast representation.
5137 /// Does not do any caching of the value in the type context.
5138 pub fn from_ast_variant(cx: &ctxt<'tcx>,
5139 ast_variant: &ast::Variant,
5140 discriminant: Disr) -> VariantInfo<'tcx> {
5141 let ctor_ty = node_id_to_type(cx, ast_variant.node.id);
5143 match ast_variant.node.kind {
5144 ast::TupleVariantKind(ref args) => {
5145 let arg_tys = if args.len() > 0 {
5146 ty_fn_args(ctor_ty).iter().map(|a| *a).collect()
5151 return VariantInfo {
5154 ctor_ty: Some(ctor_ty),
5155 name: ast_variant.node.name.name,
5156 id: ast_util::local_def(ast_variant.node.id),
5157 disr_val: discriminant,
5158 vis: ast_variant.node.vis
5161 ast::StructVariantKind(ref struct_def) => {
5163 let fields: &[StructField] = struct_def.fields[];
5165 assert!(fields.len() > 0);
5167 let arg_tys = struct_def.fields.iter()
5168 .map(|field| node_id_to_type(cx, field.node.id)).collect();
5169 let arg_names = fields.iter().map(|field| {
5170 match field.node.kind {
5171 NamedField(ident, _) => ident,
5172 UnnamedField(..) => cx.sess.bug(
5173 "enum_variants: all fields in struct must have a name")
5177 return VariantInfo {
5179 arg_names: Some(arg_names),
5181 name: ast_variant.node.name.name,
5182 id: ast_util::local_def(ast_variant.node.id),
5183 disr_val: discriminant,
5184 vis: ast_variant.node.vis
5191 pub fn substd_enum_variants<'tcx>(cx: &ctxt<'tcx>,
5193 substs: &Substs<'tcx>)
5194 -> Vec<Rc<VariantInfo<'tcx>>> {
5195 enum_variants(cx, id).iter().map(|variant_info| {
5196 let substd_args = variant_info.args.iter()
5197 .map(|aty| aty.subst(cx, substs)).collect::<Vec<_>>();
5199 let substd_ctor_ty = variant_info.ctor_ty.subst(cx, substs);
5201 Rc::new(VariantInfo {
5203 ctor_ty: substd_ctor_ty,
5204 ..(**variant_info).clone()
5209 pub fn item_path_str(cx: &ctxt, id: ast::DefId) -> String {
5210 with_path(cx, id, |path| ast_map::path_to_string(path)).to_string()
5216 TraitDtor(DefId, bool)
5220 pub fn is_present(&self) -> bool {
5222 TraitDtor(..) => true,
5227 pub fn has_drop_flag(&self) -> bool {
5230 &TraitDtor(_, flag) => flag
5235 /* If struct_id names a struct with a dtor, return Some(the dtor's id).
5236 Otherwise return none. */
5237 pub fn ty_dtor(cx: &ctxt, struct_id: DefId) -> DtorKind {
5238 match cx.destructor_for_type.borrow().get(&struct_id) {
5239 Some(&method_def_id) => {
5240 let flag = !has_attr(cx, struct_id, "unsafe_no_drop_flag");
5242 TraitDtor(method_def_id, flag)
5248 pub fn has_dtor(cx: &ctxt, struct_id: DefId) -> bool {
5249 cx.destructor_for_type.borrow().contains_key(&struct_id)
5252 pub fn with_path<T, F>(cx: &ctxt, id: ast::DefId, f: F) -> T where
5253 F: FnOnce(ast_map::PathElems) -> T,
5255 if id.krate == ast::LOCAL_CRATE {
5256 cx.map.with_path(id.node, f)
5258 f(ast_map::Values(csearch::get_item_path(cx, id).iter()).chain(None))
5262 pub fn enum_is_univariant(cx: &ctxt, id: ast::DefId) -> bool {
5263 enum_variants(cx, id).len() == 1
5266 pub fn type_is_empty(cx: &ctxt, ty: Ty) -> bool {
5268 ty_enum(did, _) => (*enum_variants(cx, did)).is_empty(),
5273 pub fn enum_variants<'tcx>(cx: &ctxt<'tcx>, id: ast::DefId)
5274 -> Rc<Vec<Rc<VariantInfo<'tcx>>>> {
5275 memoized(&cx.enum_var_cache, id, |id: ast::DefId| {
5276 if ast::LOCAL_CRATE != id.krate {
5277 Rc::new(csearch::get_enum_variants(cx, id))
5280 Although both this code and check_enum_variants in typeck/check
5281 call eval_const_expr, it should never get called twice for the same
5282 expr, since check_enum_variants also updates the enum_var_cache
5284 match cx.map.get(id.node) {
5285 ast_map::NodeItem(ref item) => {
5287 ast::ItemEnum(ref enum_definition, _) => {
5288 let mut last_discriminant: Option<Disr> = None;
5289 Rc::new(enum_definition.variants.iter().map(|variant| {
5291 let mut discriminant = match last_discriminant {
5292 Some(val) => val + 1,
5293 None => INITIAL_DISCRIMINANT_VALUE
5296 match variant.node.disr_expr {
5298 match const_eval::eval_const_expr_partial(cx, &**e) {
5299 Ok(const_eval::const_int(val)) => {
5300 discriminant = val as Disr
5302 Ok(const_eval::const_uint(val)) => {
5303 discriminant = val as Disr
5308 "expected signed integer constant");
5313 format!("expected constant: {}",
5320 last_discriminant = Some(discriminant);
5321 Rc::new(VariantInfo::from_ast_variant(cx, &**variant,
5326 cx.sess.bug("enum_variants: id not bound to an enum")
5330 _ => cx.sess.bug("enum_variants: id not bound to an enum")
5336 // Returns information about the enum variant with the given ID:
5337 pub fn enum_variant_with_id<'tcx>(cx: &ctxt<'tcx>,
5338 enum_id: ast::DefId,
5339 variant_id: ast::DefId)
5340 -> Rc<VariantInfo<'tcx>> {
5341 enum_variants(cx, enum_id).iter()
5342 .find(|variant| variant.id == variant_id)
5343 .expect("enum_variant_with_id(): no variant exists with that ID")
5348 // If the given item is in an external crate, looks up its type and adds it to
5349 // the type cache. Returns the type parameters and type.
5350 pub fn lookup_item_type<'tcx>(cx: &ctxt<'tcx>,
5352 -> TypeScheme<'tcx> {
5353 lookup_locally_or_in_crate_store(
5354 "tcache", did, &mut *cx.tcache.borrow_mut(),
5355 || csearch::get_type(cx, did))
5358 /// Given the did of a trait, returns its canonical trait ref.
5359 pub fn lookup_trait_def<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId)
5360 -> Rc<ty::TraitDef<'tcx>> {
5361 memoized(&cx.trait_defs, did, |did: DefId| {
5362 assert!(did.krate != ast::LOCAL_CRATE);
5363 Rc::new(csearch::get_trait_def(cx, did))
5367 /// Given a reference to a trait, returns the "superbounds" declared
5368 /// on the trait, with appropriate substitutions applied. Basically,
5369 /// this applies a filter to the where clauses on the trait, returning
5370 /// those that have the form:
5372 /// Self : SuperTrait<...>
5374 pub fn predicates_for_trait_ref<'tcx>(tcx: &ctxt<'tcx>,
5375 trait_ref: &PolyTraitRef<'tcx>)
5376 -> Vec<ty::Predicate<'tcx>>
5378 let trait_def = lookup_trait_def(tcx, trait_ref.def_id());
5380 debug!("bounds_for_trait_ref(trait_def={}, trait_ref={})",
5381 trait_def.repr(tcx), trait_ref.repr(tcx));
5383 // The interaction between HRTB and supertraits is not entirely
5384 // obvious. Let me walk you (and myself) through an example.
5386 // Let's start with an easy case. Consider two traits:
5388 // trait Foo<'a> : Bar<'a,'a> { }
5389 // trait Bar<'b,'c> { }
5391 // Now, if we have a trait reference `for<'x> T : Foo<'x>`, then
5392 // we can deduce that `for<'x> T : Bar<'x,'x>`. Basically, if we
5393 // knew that `Foo<'x>` (for any 'x) then we also know that
5394 // `Bar<'x,'x>` (for any 'x). This more-or-less falls out from
5395 // normal substitution.
5397 // In terms of why this is sound, the idea is that whenever there
5398 // is an impl of `T:Foo<'a>`, it must show that `T:Bar<'a,'a>`
5399 // holds. So if there is an impl of `T:Foo<'a>` that applies to
5400 // all `'a`, then we must know that `T:Bar<'a,'a>` holds for all
5403 // Another example to be careful of is this:
5405 // trait Foo1<'a> : for<'b> Bar1<'a,'b> { }
5406 // trait Bar1<'b,'c> { }
5408 // Here, if we have `for<'x> T : Foo1<'x>`, then what do we know?
5409 // The answer is that we know `for<'x,'b> T : Bar1<'x,'b>`. The
5410 // reason is similar to the previous example: any impl of
5411 // `T:Foo1<'x>` must show that `for<'b> T : Bar1<'x, 'b>`. So
5412 // basically we would want to collapse the bound lifetimes from
5413 // the input (`trait_ref`) and the supertraits.
5415 // To achieve this in practice is fairly straightforward. Let's
5416 // consider the more complicated scenario:
5418 // - We start out with `for<'x> T : Foo1<'x>`. In this case, `'x`
5419 // has a De Bruijn index of 1. We want to produce `for<'x,'b> T : Bar1<'x,'b>`,
5420 // where both `'x` and `'b` would have a DB index of 1.
5421 // The substitution from the input trait-ref is therefore going to be
5422 // `'a => 'x` (where `'x` has a DB index of 1).
5423 // - The super-trait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an
5424 // early-bound parameter and `'b' is a late-bound parameter with a
5426 // - If we replace `'a` with `'x` from the input, it too will have
5427 // a DB index of 1, and thus we'll have `for<'x,'b> Bar1<'x,'b>`
5428 // just as we wanted.
5430 // There is only one catch. If we just apply the substitution `'a
5431 // => 'x` to `for<'b> Bar1<'a,'b>`, the substitution code will
5432 // adjust the DB index because we substituting into a binder (it
5433 // tries to be so smart...) resulting in `for<'x> for<'b>
5434 // Bar1<'x,'b>` (we have no syntax for this, so use your
5435 // imagination). Basically the 'x will have DB index of 2 and 'b
5436 // will have DB index of 1. Not quite what we want. So we apply
5437 // the substitution to the *contents* of the trait reference,
5438 // rather than the trait reference itself (put another way, the
5439 // substitution code expects equal binding levels in the values
5440 // from the substitution and the value being substituted into, and
5441 // this trick achieves that).
5443 // Carefully avoid the binder introduced by each trait-ref by
5444 // substituting over the substs, not the trait-refs themselves,
5445 // thus achieving the "collapse" described in the big comment
5447 let trait_bounds: Vec<_> =
5448 trait_def.bounds.trait_bounds
5450 .map(|poly_trait_ref| ty::Binder(poly_trait_ref.0.subst(tcx, trait_ref.substs())))
5453 let projection_bounds: Vec<_> =
5454 trait_def.bounds.projection_bounds
5456 .map(|poly_proj| ty::Binder(poly_proj.0.subst(tcx, trait_ref.substs())))
5459 debug!("bounds_for_trait_ref: trait_bounds={} projection_bounds={}",
5460 trait_bounds.repr(tcx),
5461 projection_bounds.repr(tcx));
5463 // The region bounds and builtin bounds do not currently introduce
5464 // binders so we can just substitute in a straightforward way here.
5466 trait_def.bounds.region_bounds.subst(tcx, trait_ref.substs());
5467 let builtin_bounds =
5468 trait_def.bounds.builtin_bounds.subst(tcx, trait_ref.substs());
5470 let bounds = ty::ParamBounds {
5471 trait_bounds: trait_bounds,
5472 region_bounds: region_bounds,
5473 builtin_bounds: builtin_bounds,
5474 projection_bounds: projection_bounds,
5477 predicates(tcx, trait_ref.self_ty(), &bounds)
5480 pub fn predicates<'tcx>(
5483 bounds: &ParamBounds<'tcx>)
5484 -> Vec<Predicate<'tcx>>
5486 let mut vec = Vec::new();
5488 for builtin_bound in bounds.builtin_bounds.iter() {
5489 match traits::trait_ref_for_builtin_bound(tcx, builtin_bound, param_ty) {
5490 Ok(trait_ref) => { vec.push(trait_ref.as_predicate()); }
5491 Err(ErrorReported) => { }
5495 for ®ion_bound in bounds.region_bounds.iter() {
5496 // account for the binder being introduced below; no need to shift `param_ty`
5497 // because, at present at least, it can only refer to early-bound regions
5498 let region_bound = ty_fold::shift_region(region_bound, 1);
5499 vec.push(ty::Binder(ty::OutlivesPredicate(param_ty, region_bound)).as_predicate());
5502 for bound_trait_ref in bounds.trait_bounds.iter() {
5503 vec.push(bound_trait_ref.as_predicate());
5506 for projection in bounds.projection_bounds.iter() {
5507 vec.push(projection.as_predicate());
5513 /// Iterate over attributes of a definition.
5514 // (This should really be an iterator, but that would require csearch and
5515 // decoder to use iterators instead of higher-order functions.)
5516 pub fn each_attr<F>(tcx: &ctxt, did: DefId, mut f: F) -> bool where
5517 F: FnMut(&ast::Attribute) -> bool,
5520 let item = tcx.map.expect_item(did.node);
5521 item.attrs.iter().all(|attr| f(attr))
5523 info!("getting foreign attrs");
5524 let mut cont = true;
5525 csearch::get_item_attrs(&tcx.sess.cstore, did, |attrs| {
5527 cont = attrs.iter().all(|attr| f(attr));
5535 /// Determine whether an item is annotated with an attribute
5536 pub fn has_attr(tcx: &ctxt, did: DefId, attr: &str) -> bool {
5537 let mut found = false;
5538 each_attr(tcx, did, |item| {
5539 if item.check_name(attr) {
5549 /// Determine whether an item is annotated with `#[repr(packed)]`
5550 pub fn lookup_packed(tcx: &ctxt, did: DefId) -> bool {
5551 lookup_repr_hints(tcx, did).contains(&attr::ReprPacked)
5554 /// Determine whether an item is annotated with `#[simd]`
5555 pub fn lookup_simd(tcx: &ctxt, did: DefId) -> bool {
5556 has_attr(tcx, did, "simd")
5559 /// Obtain the representation annotation for a struct definition.
5560 pub fn lookup_repr_hints(tcx: &ctxt, did: DefId) -> Rc<Vec<attr::ReprAttr>> {
5561 memoized(&tcx.repr_hint_cache, did, |did: DefId| {
5562 Rc::new(if did.krate == LOCAL_CRATE {
5563 let mut acc = Vec::new();
5564 ty::each_attr(tcx, did, |meta| {
5565 acc.extend(attr::find_repr_attrs(tcx.sess.diagnostic(),
5571 csearch::get_repr_attrs(&tcx.sess.cstore, did)
5576 // Look up a field ID, whether or not it's local
5577 // Takes a list of type substs in case the struct is generic
5578 pub fn lookup_field_type<'tcx>(tcx: &ctxt<'tcx>,
5581 substs: &Substs<'tcx>)
5583 let ty = if id.krate == ast::LOCAL_CRATE {
5584 node_id_to_type(tcx, id.node)
5586 let mut tcache = tcx.tcache.borrow_mut();
5587 let pty = tcache.entry(&id).get().unwrap_or_else(
5588 |vacant_entry| vacant_entry.insert(csearch::get_field_type(tcx, struct_id, id)));
5591 ty.subst(tcx, substs)
5594 // Look up the list of field names and IDs for a given struct.
5595 // Panics if the id is not bound to a struct.
5596 pub fn lookup_struct_fields(cx: &ctxt, did: ast::DefId) -> Vec<field_ty> {
5597 if did.krate == ast::LOCAL_CRATE {
5598 let struct_fields = cx.struct_fields.borrow();
5599 match struct_fields.get(&did) {
5600 Some(fields) => (**fields).clone(),
5603 format!("ID not mapped to struct fields: {}",
5604 cx.map.node_to_string(did.node))[]);
5608 csearch::get_struct_fields(&cx.sess.cstore, did)
5612 pub fn is_tuple_struct(cx: &ctxt, did: ast::DefId) -> bool {
5613 let fields = lookup_struct_fields(cx, did);
5614 !fields.is_empty() && fields.iter().all(|f| f.name == token::special_names::unnamed_field)
5617 // Returns a list of fields corresponding to the struct's items. trans uses
5618 // this. Takes a list of substs with which to instantiate field types.
5619 pub fn struct_fields<'tcx>(cx: &ctxt<'tcx>, did: ast::DefId, substs: &Substs<'tcx>)
5620 -> Vec<field<'tcx>> {
5621 lookup_struct_fields(cx, did).iter().map(|f| {
5625 ty: lookup_field_type(cx, did, f.id, substs),
5632 // Returns a list of fields corresponding to the tuple's items. trans uses
5634 pub fn tup_fields<'tcx>(v: &[Ty<'tcx>]) -> Vec<field<'tcx>> {
5635 v.iter().enumerate().map(|(i, &f)| {
5637 name: token::intern(i.to_string()[]),
5646 #[derive(Copy, Clone)]
5647 pub struct UnboxedClosureUpvar<'tcx> {
5653 // Returns a list of `UnboxedClosureUpvar`s for each upvar.
5654 pub fn unboxed_closure_upvars<'tcx>(typer: &mc::Typer<'tcx>,
5655 closure_id: ast::DefId,
5656 substs: &Substs<'tcx>)
5657 -> Option<Vec<UnboxedClosureUpvar<'tcx>>>
5659 // Presently an unboxed closure type cannot "escape" out of a
5660 // function, so we will only encounter ones that originated in the
5661 // local crate or were inlined into it along with some function.
5662 // This may change if abstract return types of some sort are
5664 assert!(closure_id.krate == ast::LOCAL_CRATE);
5665 let tcx = typer.tcx();
5666 let capture_mode = tcx.capture_modes.borrow()[closure_id.node].clone();
5667 match tcx.freevars.borrow().get(&closure_id.node) {
5668 None => Some(vec![]),
5669 Some(ref freevars) => {
5672 let freevar_def_id = freevar.def.def_id();
5673 let freevar_ty = match typer.node_ty(freevar_def_id.node) {
5675 Err(()) => { return None; }
5677 let freevar_ty = freevar_ty.subst(tcx, substs);
5679 match capture_mode {
5680 ast::CaptureByValue => {
5681 Some(UnboxedClosureUpvar { def: freevar.def,
5686 ast::CaptureByRef => {
5687 let upvar_id = ty::UpvarId {
5688 var_id: freevar_def_id.node,
5689 closure_expr_id: closure_id.node
5693 let freevar_ref_ty = match typer.upvar_borrow(upvar_id) {
5696 tcx.mk_region(borrow.region),
5699 mutbl: borrow.kind.to_mutbl_lossy(),
5703 // FIXME(#16640) we should really return None here;
5704 // but that requires better inference integration,
5705 // for now gin up something.
5709 Some(UnboxedClosureUpvar {
5722 pub fn is_binopable<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>, op: ast::BinOp) -> bool {
5723 #![allow(non_upper_case_globals)]
5724 static tycat_other: int = 0;
5725 static tycat_bool: int = 1;
5726 static tycat_char: int = 2;
5727 static tycat_int: int = 3;
5728 static tycat_float: int = 4;
5729 static tycat_raw_ptr: int = 6;
5731 static opcat_add: int = 0;
5732 static opcat_sub: int = 1;
5733 static opcat_mult: int = 2;
5734 static opcat_shift: int = 3;
5735 static opcat_rel: int = 4;
5736 static opcat_eq: int = 5;
5737 static opcat_bit: int = 6;
5738 static opcat_logic: int = 7;
5739 static opcat_mod: int = 8;
5741 fn opcat(op: ast::BinOp) -> int {
5743 ast::BiAdd => opcat_add,
5744 ast::BiSub => opcat_sub,
5745 ast::BiMul => opcat_mult,
5746 ast::BiDiv => opcat_mult,
5747 ast::BiRem => opcat_mod,
5748 ast::BiAnd => opcat_logic,
5749 ast::BiOr => opcat_logic,
5750 ast::BiBitXor => opcat_bit,
5751 ast::BiBitAnd => opcat_bit,
5752 ast::BiBitOr => opcat_bit,
5753 ast::BiShl => opcat_shift,
5754 ast::BiShr => opcat_shift,
5755 ast::BiEq => opcat_eq,
5756 ast::BiNe => opcat_eq,
5757 ast::BiLt => opcat_rel,
5758 ast::BiLe => opcat_rel,
5759 ast::BiGe => opcat_rel,
5760 ast::BiGt => opcat_rel
5764 fn tycat<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> int {
5765 if type_is_simd(cx, ty) {
5766 return tycat(cx, simd_type(cx, ty))
5769 ty_char => tycat_char,
5770 ty_bool => tycat_bool,
5771 ty_int(_) | ty_uint(_) | ty_infer(IntVar(_)) => tycat_int,
5772 ty_float(_) | ty_infer(FloatVar(_)) => tycat_float,
5773 ty_ptr(_) => tycat_raw_ptr,
5778 static t: bool = true;
5779 static f: bool = false;
5782 // +, -, *, shift, rel, ==, bit, logic, mod
5783 /*other*/ [f, f, f, f, f, f, f, f, f],
5784 /*bool*/ [f, f, f, f, t, t, t, t, f],
5785 /*char*/ [f, f, f, f, t, t, f, f, f],
5786 /*int*/ [t, t, t, t, t, t, t, f, t],
5787 /*float*/ [t, t, t, f, t, t, f, f, f],
5788 /*bot*/ [t, t, t, t, t, t, t, t, t],
5789 /*raw ptr*/ [f, f, f, f, t, t, f, f, f]];
5791 return tbl[tycat(cx, ty) as uint ][opcat(op) as uint];
5794 /// Returns an equivalent type with all the typedefs and self regions removed.
5795 pub fn normalize_ty<'tcx>(cx: &ctxt<'tcx>, ty: Ty<'tcx>) -> Ty<'tcx> {
5796 let u = TypeNormalizer(cx).fold_ty(ty);
5799 struct TypeNormalizer<'a, 'tcx: 'a>(&'a ctxt<'tcx>);
5801 impl<'a, 'tcx> TypeFolder<'tcx> for TypeNormalizer<'a, 'tcx> {
5802 fn tcx(&self) -> &ctxt<'tcx> { let TypeNormalizer(c) = *self; c }
5804 fn fold_ty(&mut self, ty: Ty<'tcx>) -> Ty<'tcx> {
5805 match self.tcx().normalized_cache.borrow().get(&ty).cloned() {
5810 let t_norm = ty_fold::super_fold_ty(self, ty);
5811 self.tcx().normalized_cache.borrow_mut().insert(ty, t_norm);
5815 fn fold_region(&mut self, _: ty::Region) -> ty::Region {
5819 fn fold_substs(&mut self,
5820 substs: &subst::Substs<'tcx>)
5821 -> subst::Substs<'tcx> {
5822 subst::Substs { regions: subst::ErasedRegions,
5823 types: substs.types.fold_with(self) }
5828 // Returns the repeat count for a repeating vector expression.
5829 pub fn eval_repeat_count(tcx: &ctxt, count_expr: &ast::Expr) -> uint {
5830 match const_eval::eval_const_expr_partial(tcx, count_expr) {
5832 let found = match val {
5833 const_eval::const_uint(count) => return count as uint,
5834 const_eval::const_int(count) if count >= 0 => return count as uint,
5835 const_eval::const_int(_) =>
5837 const_eval::const_float(_) =>
5839 const_eval::const_str(_) =>
5841 const_eval::const_bool(_) =>
5843 const_eval::const_binary(_) =>
5846 tcx.sess.span_err(count_expr.span, format!(
5847 "expected positive integer for repeat count, found {}",
5851 let found = match count_expr.node {
5852 ast::ExprPath(ast::Path {
5856 }) if segments.len() == 1 =>
5859 "non-constant expression"
5861 tcx.sess.span_err(count_expr.span, format!(
5862 "expected constant integer for repeat count, found {}",
5869 // Iterate over a type parameter's bounded traits and any supertraits
5870 // of those traits, ignoring kinds.
5871 // Here, the supertraits are the transitive closure of the supertrait
5872 // relation on the supertraits from each bounded trait's constraint
5874 pub fn each_bound_trait_and_supertraits<'tcx, F>(tcx: &ctxt<'tcx>,
5875 bounds: &[PolyTraitRef<'tcx>],
5878 F: FnMut(PolyTraitRef<'tcx>) -> bool,
5880 for bound_trait_ref in traits::transitive_bounds(tcx, bounds) {
5881 if !f(bound_trait_ref) {
5888 pub fn object_region_bounds<'tcx>(
5890 opt_principal: Option<&PolyTraitRef<'tcx>>, // None for closures
5891 others: BuiltinBounds)
5894 // Since we don't actually *know* the self type for an object,
5895 // this "open(err)" serves as a kind of dummy standin -- basically
5896 // a skolemized type.
5897 let open_ty = ty::mk_infer(tcx, FreshTy(0));
5899 let opt_trait_ref = opt_principal.map_or(Vec::new(), |principal| {
5900 // Note that we preserve the overall binding levels here.
5901 assert!(!open_ty.has_escaping_regions());
5902 let substs = tcx.mk_substs(principal.0.substs.with_self_ty(open_ty));
5903 vec!(ty::Binder(Rc::new(ty::TraitRef::new(principal.0.def_id, substs))))
5906 let param_bounds = ty::ParamBounds {
5907 region_bounds: Vec::new(),
5908 builtin_bounds: others,
5909 trait_bounds: opt_trait_ref,
5910 projection_bounds: Vec::new(), // not relevant to computing region bounds
5913 let predicates = ty::predicates(tcx, open_ty, ¶m_bounds);
5914 ty::required_region_bounds(tcx, open_ty, predicates)
5917 /// Given a set of predicates that apply to an object type, returns
5918 /// the region bounds that the (erased) `Self` type must
5919 /// outlive. Precisely *because* the `Self` type is erased, the
5920 /// parameter `erased_self_ty` must be supplied to indicate what type
5921 /// has been used to represent `Self` in the predicates
5922 /// themselves. This should really be a unique type; `FreshTy(0)` is a
5923 /// popular choice (see `object_region_bounds` above).
5925 /// Requires that trait definitions have been processed so that we can
5926 /// elaborate predicates and walk supertraits.
5927 pub fn required_region_bounds<'tcx>(tcx: &ctxt<'tcx>,
5928 erased_self_ty: Ty<'tcx>,
5929 predicates: Vec<ty::Predicate<'tcx>>)
5932 debug!("required_region_bounds(erased_self_ty={}, predicates={})",
5933 erased_self_ty.repr(tcx),
5934 predicates.repr(tcx));
5936 assert!(!erased_self_ty.has_escaping_regions());
5938 traits::elaborate_predicates(tcx, predicates)
5939 .filter_map(|predicate| {
5941 ty::Predicate::Projection(..) |
5942 ty::Predicate::Trait(..) |
5943 ty::Predicate::Equate(..) |
5944 ty::Predicate::RegionOutlives(..) => {
5947 ty::Predicate::TypeOutlives(ty::Binder(ty::OutlivesPredicate(t, r))) => {
5948 // Search for a bound of the form `erased_self_ty
5949 // : 'a`, but be wary of something like `for<'a>
5950 // erased_self_ty : 'a` (we interpret a
5951 // higher-ranked bound like that as 'static,
5952 // though at present the code in `fulfill.rs`
5953 // considers such bounds to be unsatisfiable, so
5954 // it's kind of a moot point since you could never
5955 // construct such an object, but this seems
5956 // correct even if that code changes).
5957 if t == erased_self_ty && !r.has_escaping_regions() {
5958 if r.has_escaping_regions() {
5972 pub fn get_tydesc_ty<'tcx>(tcx: &ctxt<'tcx>) -> Result<Ty<'tcx>, String> {
5973 tcx.lang_items.require(TyDescStructLangItem).map(|tydesc_lang_item| {
5974 tcx.intrinsic_defs.borrow().get(&tydesc_lang_item).cloned()
5975 .expect("Failed to resolve TyDesc")
5979 pub fn item_variances(tcx: &ctxt, item_id: ast::DefId) -> Rc<ItemVariances> {
5980 lookup_locally_or_in_crate_store(
5981 "item_variance_map", item_id, &mut *tcx.item_variance_map.borrow_mut(),
5982 || Rc::new(csearch::get_item_variances(&tcx.sess.cstore, item_id)))
5985 /// Records a trait-to-implementation mapping.
5986 pub fn record_trait_implementation(tcx: &ctxt,
5987 trait_def_id: DefId,
5988 impl_def_id: DefId) {
5989 match tcx.trait_impls.borrow().get(&trait_def_id) {
5990 Some(impls_for_trait) => {
5991 impls_for_trait.borrow_mut().push(impl_def_id);
5996 tcx.trait_impls.borrow_mut().insert(trait_def_id, Rc::new(RefCell::new(vec!(impl_def_id))));
5999 /// Populates the type context with all the implementations for the given type
6001 pub fn populate_implementations_for_type_if_necessary(tcx: &ctxt,
6002 type_id: ast::DefId) {
6003 if type_id.krate == LOCAL_CRATE {
6006 if tcx.populated_external_types.borrow().contains(&type_id) {
6010 debug!("populate_implementations_for_type_if_necessary: searching for {}", type_id);
6012 let mut inherent_impls = Vec::new();
6013 csearch::each_implementation_for_type(&tcx.sess.cstore, type_id,
6015 let impl_items = csearch::get_impl_items(&tcx.sess.cstore, impl_def_id);
6017 // Record the trait->implementation mappings, if applicable.
6018 let associated_traits = csearch::get_impl_trait(tcx, impl_def_id);
6019 for trait_ref in associated_traits.iter() {
6020 record_trait_implementation(tcx, trait_ref.def_id, impl_def_id);
6023 // For any methods that use a default implementation, add them to
6024 // the map. This is a bit unfortunate.
6025 for impl_item_def_id in impl_items.iter() {
6026 let method_def_id = impl_item_def_id.def_id();
6027 match impl_or_trait_item(tcx, method_def_id) {
6028 MethodTraitItem(method) => {
6029 for &source in method.provided_source.iter() {
6030 tcx.provided_method_sources
6032 .insert(method_def_id, source);
6035 TypeTraitItem(_) => {}
6039 // Store the implementation info.
6040 tcx.impl_items.borrow_mut().insert(impl_def_id, impl_items);
6042 // If this is an inherent implementation, record it.
6043 if associated_traits.is_none() {
6044 inherent_impls.push(impl_def_id);
6048 tcx.inherent_impls.borrow_mut().insert(type_id, Rc::new(inherent_impls));
6049 tcx.populated_external_types.borrow_mut().insert(type_id);
6052 /// Populates the type context with all the implementations for the given
6053 /// trait if necessary.
6054 pub fn populate_implementations_for_trait_if_necessary(
6056 trait_id: ast::DefId) {
6057 if trait_id.krate == LOCAL_CRATE {
6060 if tcx.populated_external_traits.borrow().contains(&trait_id) {
6064 csearch::each_implementation_for_trait(&tcx.sess.cstore, trait_id,
6065 |implementation_def_id| {
6066 let impl_items = csearch::get_impl_items(&tcx.sess.cstore, implementation_def_id);
6068 // Record the trait->implementation mapping.
6069 record_trait_implementation(tcx, trait_id, implementation_def_id);
6071 // For any methods that use a default implementation, add them to
6072 // the map. This is a bit unfortunate.
6073 for impl_item_def_id in impl_items.iter() {
6074 let method_def_id = impl_item_def_id.def_id();
6075 match impl_or_trait_item(tcx, method_def_id) {
6076 MethodTraitItem(method) => {
6077 for &source in method.provided_source.iter() {
6078 tcx.provided_method_sources
6080 .insert(method_def_id, source);
6083 TypeTraitItem(_) => {}
6087 // Store the implementation info.
6088 tcx.impl_items.borrow_mut().insert(implementation_def_id, impl_items);
6091 tcx.populated_external_traits.borrow_mut().insert(trait_id);
6094 /// Given the def_id of an impl, return the def_id of the trait it implements.
6095 /// If it implements no trait, return `None`.
6096 pub fn trait_id_of_impl(tcx: &ctxt,
6098 -> Option<ast::DefId> {
6099 ty::impl_trait_ref(tcx, def_id).map(|tr| tr.def_id)
6102 /// If the given def ID describes a method belonging to an impl, return the
6103 /// ID of the impl that the method belongs to. Otherwise, return `None`.
6104 pub fn impl_of_method(tcx: &ctxt, def_id: ast::DefId)
6105 -> Option<ast::DefId> {
6106 if def_id.krate != LOCAL_CRATE {
6107 return match csearch::get_impl_or_trait_item(tcx,
6108 def_id).container() {
6109 TraitContainer(_) => None,
6110 ImplContainer(def_id) => Some(def_id),
6113 match tcx.impl_or_trait_items.borrow().get(&def_id).cloned() {
6114 Some(trait_item) => {
6115 match trait_item.container() {
6116 TraitContainer(_) => None,
6117 ImplContainer(def_id) => Some(def_id),
6124 /// If the given def ID describes an item belonging to a trait (either a
6125 /// default method or an implementation of a trait method), return the ID of
6126 /// the trait that the method belongs to. Otherwise, return `None`.
6127 pub fn trait_of_item(tcx: &ctxt, def_id: ast::DefId) -> Option<ast::DefId> {
6128 if def_id.krate != LOCAL_CRATE {
6129 return csearch::get_trait_of_item(&tcx.sess.cstore, def_id, tcx);
6131 match tcx.impl_or_trait_items.borrow().get(&def_id).cloned() {
6132 Some(impl_or_trait_item) => {
6133 match impl_or_trait_item.container() {
6134 TraitContainer(def_id) => Some(def_id),
6135 ImplContainer(def_id) => trait_id_of_impl(tcx, def_id),
6142 /// If the given def ID describes an item belonging to a trait, (either a
6143 /// default method or an implementation of a trait method), return the ID of
6144 /// the method inside trait definition (this means that if the given def ID
6145 /// is already that of the original trait method, then the return value is
6147 /// Otherwise, return `None`.
6148 pub fn trait_item_of_item(tcx: &ctxt, def_id: ast::DefId)
6149 -> Option<ImplOrTraitItemId> {
6150 let impl_item = match tcx.impl_or_trait_items.borrow().get(&def_id) {
6151 Some(m) => m.clone(),
6152 None => return None,
6154 let name = impl_item.name();
6155 match trait_of_item(tcx, def_id) {
6156 Some(trait_did) => {
6157 let trait_items = ty::trait_items(tcx, trait_did);
6159 .position(|m| m.name() == name)
6160 .map(|idx| ty::trait_item(tcx, trait_did, idx).id())
6166 /// Creates a hash of the type `Ty` which will be the same no matter what crate
6167 /// context it's calculated within. This is used by the `type_id` intrinsic.
6168 pub fn hash_crate_independent<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>, svh: &Svh) -> u64 {
6169 let mut state = sip::SipState::new();
6170 helper(tcx, ty, svh, &mut state);
6171 return state.result();
6173 fn helper<'tcx>(tcx: &ctxt<'tcx>, ty: Ty<'tcx>, svh: &Svh, state: &mut sip::SipState) {
6174 macro_rules! byte { ($b:expr) => { ($b as u8).hash(state) } }
6175 macro_rules! hash { ($e:expr) => { $e.hash(state) } }
6177 let region = |&: state: &mut sip::SipState, r: Region| {
6180 ReLateBound(db, BrAnon(i)) => {
6190 tcx.sess.bug("unexpected region found when hashing a type")
6194 let did = |&: state: &mut sip::SipState, did: DefId| {
6195 let h = if ast_util::is_local(did) {
6198 tcx.sess.cstore.get_crate_hash(did.krate)
6200 h.as_str().hash(state);
6201 did.node.hash(state);
6203 let mt = |&: state: &mut sip::SipState, mt: mt| {
6204 mt.mutbl.hash(state);
6206 let fn_sig = |&: state: &mut sip::SipState, sig: &Binder<FnSig<'tcx>>| {
6207 let sig = anonymize_late_bound_regions(tcx, sig);
6208 for a in sig.inputs.iter() { helper(tcx, *a, svh, state); }
6209 if let ty::FnConverging(output) = sig.output {
6210 helper(tcx, output, svh, state);
6213 maybe_walk_ty(ty, |ty| {
6215 ty_bool => byte!(2),
6216 ty_char => byte!(3),
6239 ty_vec(_, Some(n)) => {
6243 ty_vec(_, None) => {
6255 ty_bare_fn(opt_def_id, ref b) => {
6260 fn_sig(state, &b.sig);
6263 ty_trait(ref data) => {
6265 did(state, data.principal_def_id());
6268 let principal = anonymize_late_bound_regions(tcx, &data.principal);
6269 for subty in principal.substs.types.iter() {
6270 helper(tcx, *subty, svh, state);
6275 ty_struct(d, _) => {
6279 ty_tup(ref inner) => {
6287 hash!(token::get_name(p.name));
6289 ty_open(_) => byte!(22),
6290 ty_infer(_) => unreachable!(),
6291 ty_err => byte!(23),
6292 ty_unboxed_closure(d, r, _) => {
6297 ty_projection(ref data) => {
6299 did(state, data.trait_ref.def_id);
6300 hash!(token::get_name(data.item_name));
6309 pub fn to_string(self) -> &'static str {
6312 Contravariant => "-",
6319 /// Construct a parameter environment suitable for static contexts or other contexts where there
6320 /// are no free type/lifetime parameters in scope.
6321 pub fn empty_parameter_environment<'a,'tcx>(cx: &'a ctxt<'tcx>) -> ParameterEnvironment<'a,'tcx> {
6322 ty::ParameterEnvironment { tcx: cx,
6323 free_substs: Substs::empty(),
6324 caller_bounds: GenericBounds::empty(),
6325 implicit_region_bound: ty::ReEmpty,
6326 selection_cache: traits::SelectionCache::new(), }
6329 /// See `ParameterEnvironment` struct def'n for details
6330 pub fn construct_parameter_environment<'a,'tcx>(
6331 tcx: &'a ctxt<'tcx>,
6332 generics: &ty::Generics<'tcx>,
6333 free_id: ast::NodeId)
6334 -> ParameterEnvironment<'a, 'tcx>
6338 // Construct the free substs.
6342 let mut types = VecPerParamSpace::empty();
6343 push_types_from_defs(tcx, &mut types, generics.types.as_slice());
6345 // map bound 'a => free 'a
6346 let mut regions = VecPerParamSpace::empty();
6347 push_region_params(&mut regions, free_id, generics.regions.as_slice());
6349 let free_substs = Substs {
6351 regions: subst::NonerasedRegions(regions)
6354 let free_id_scope = region::CodeExtent::from_node_id(free_id);
6357 // Compute the bounds on Self and the type parameters.
6360 let bounds = generics.to_bounds(tcx, &free_substs);
6361 let bounds = liberate_late_bound_regions(tcx, free_id_scope, &ty::Binder(bounds));
6364 // Compute region bounds. For now, these relations are stored in a
6365 // global table on the tcx, so just enter them there. I'm not
6366 // crazy about this scheme, but it's convenient, at least.
6369 record_region_bounds(tcx, &bounds);
6371 debug!("construct_parameter_environment: free_id={} free_subst={} bounds={}",
6373 free_substs.repr(tcx),
6376 return ty::ParameterEnvironment {
6378 free_substs: free_substs,
6379 implicit_region_bound: ty::ReScope(free_id_scope),
6380 caller_bounds: bounds,
6381 selection_cache: traits::SelectionCache::new(),
6384 fn push_region_params(regions: &mut VecPerParamSpace<ty::Region>,
6385 free_id: ast::NodeId,
6386 region_params: &[RegionParameterDef])
6388 for r in region_params.iter() {
6389 regions.push(r.space, ty::free_region_from_def(free_id, r));
6393 fn push_types_from_defs<'tcx>(tcx: &ty::ctxt<'tcx>,
6394 types: &mut VecPerParamSpace<Ty<'tcx>>,
6395 defs: &[TypeParameterDef<'tcx>]) {
6396 for def in defs.iter() {
6397 debug!("construct_parameter_environment(): push_types_from_defs: def={}",
6399 let ty = ty::mk_param_from_def(tcx, def);
6400 types.push(def.space, ty);
6404 fn record_region_bounds<'tcx>(tcx: &ty::ctxt<'tcx>, bounds: &GenericBounds<'tcx>) {
6405 debug!("record_region_bounds(bounds={})", bounds.repr(tcx));
6407 for predicate in bounds.predicates.iter() {
6409 Predicate::Projection(..) |
6410 Predicate::Trait(..) |
6411 Predicate::Equate(..) |
6412 Predicate::TypeOutlives(..) => {
6413 // No region bounds here
6415 Predicate::RegionOutlives(ty::Binder(ty::OutlivesPredicate(r_a, r_b))) => {
6417 (ty::ReFree(fr_a), ty::ReFree(fr_b)) => {
6418 // Record that `'a:'b`. Or, put another way, `'b <= 'a`.
6419 tcx.region_maps.relate_free_regions(fr_b, fr_a);
6422 // All named regions are instantiated with free regions.
6424 format!("record_region_bounds: non free region: {} / {}",
6426 r_b.repr(tcx)).as_slice());
6436 pub fn from_mutbl(m: ast::Mutability) -> BorrowKind {
6438 ast::MutMutable => MutBorrow,
6439 ast::MutImmutable => ImmBorrow,
6443 /// Returns a mutability `m` such that an `&m T` pointer could be used to obtain this borrow
6444 /// kind. Because borrow kinds are richer than mutabilities, we sometimes have to pick a
6445 /// mutability that is stronger than necessary so that it at least *would permit* the borrow in
6447 pub fn to_mutbl_lossy(self) -> ast::Mutability {
6449 MutBorrow => ast::MutMutable,
6450 ImmBorrow => ast::MutImmutable,
6452 // We have no type corresponding to a unique imm borrow, so
6453 // use `&mut`. It gives all the capabilities of an `&uniq`
6454 // and hence is a safe "over approximation".
6455 UniqueImmBorrow => ast::MutMutable,
6459 pub fn to_user_str(&self) -> &'static str {
6461 MutBorrow => "mutable",
6462 ImmBorrow => "immutable",
6463 UniqueImmBorrow => "uniquely immutable",
6468 impl<'tcx> ctxt<'tcx> {
6469 pub fn capture_mode(&self, closure_expr_id: ast::NodeId)
6470 -> ast::CaptureClause {
6471 self.capture_modes.borrow()[closure_expr_id].clone()
6474 pub fn is_method_call(&self, expr_id: ast::NodeId) -> bool {
6475 self.method_map.borrow().contains_key(&MethodCall::expr(expr_id))
6479 impl<'a,'tcx> mc::Typer<'tcx> for ParameterEnvironment<'a,'tcx> {
6480 fn tcx(&self) -> &ty::ctxt<'tcx> {
6484 fn node_ty(&self, id: ast::NodeId) -> mc::McResult<Ty<'tcx>> {
6485 Ok(ty::node_id_to_type(self.tcx, id))
6488 fn expr_ty_adjusted(&self, expr: &ast::Expr) -> mc::McResult<Ty<'tcx>> {
6489 Ok(ty::expr_ty_adjusted(self.tcx, expr))
6492 fn node_method_ty(&self, method_call: ty::MethodCall) -> Option<Ty<'tcx>> {
6493 self.tcx.method_map.borrow().get(&method_call).map(|method| method.ty)
6496 fn node_method_origin(&self, method_call: ty::MethodCall)
6497 -> Option<ty::MethodOrigin<'tcx>>
6499 self.tcx.method_map.borrow().get(&method_call).map(|method| method.origin.clone())
6502 fn adjustments(&self) -> &RefCell<NodeMap<ty::AutoAdjustment<'tcx>>> {
6503 &self.tcx.adjustments
6506 fn is_method_call(&self, id: ast::NodeId) -> bool {
6507 self.tcx.is_method_call(id)
6510 fn temporary_scope(&self, rvalue_id: ast::NodeId) -> Option<region::CodeExtent> {
6511 self.tcx.region_maps.temporary_scope(rvalue_id)
6514 fn upvar_borrow(&self, upvar_id: ty::UpvarId) -> Option<ty::UpvarBorrow> {
6515 Some(self.tcx.upvar_borrow_map.borrow()[upvar_id].clone())
6518 fn capture_mode(&self, closure_expr_id: ast::NodeId)
6519 -> ast::CaptureClause {
6520 self.tcx.capture_mode(closure_expr_id)
6523 fn type_moves_by_default(&self, span: Span, ty: Ty<'tcx>) -> bool {
6524 type_moves_by_default(self, span, ty)
6528 impl<'a,'tcx> UnboxedClosureTyper<'tcx> for ty::ParameterEnvironment<'a,'tcx> {
6529 fn param_env<'b>(&'b self) -> &'b ty::ParameterEnvironment<'b,'tcx> {
6533 fn unboxed_closure_kind(&self,
6535 -> ty::UnboxedClosureKind
6537 self.tcx.unboxed_closure_kind(def_id)
6540 fn unboxed_closure_type(&self,
6542 substs: &subst::Substs<'tcx>)
6543 -> ty::ClosureTy<'tcx>
6545 self.tcx.unboxed_closure_type(def_id, substs)
6548 fn unboxed_closure_upvars(&self,
6550 substs: &Substs<'tcx>)
6551 -> Option<Vec<UnboxedClosureUpvar<'tcx>>>
6553 unboxed_closure_upvars(self, def_id, substs)
6558 /// The category of explicit self.
6559 #[derive(Clone, Copy, Eq, PartialEq, Show)]
6560 pub enum ExplicitSelfCategory {
6561 StaticExplicitSelfCategory,
6562 ByValueExplicitSelfCategory,
6563 ByReferenceExplicitSelfCategory(Region, ast::Mutability),
6564 ByBoxExplicitSelfCategory,
6567 /// Pushes all the lifetimes in the given type onto the given list. A
6568 /// "lifetime in a type" is a lifetime specified by a reference or a lifetime
6569 /// in a list of type substitutions. This does *not* traverse into nominal
6570 /// types, nor does it resolve fictitious types.
6571 pub fn accumulate_lifetimes_in_type(accumulator: &mut Vec<ty::Region>,
6575 ty_rptr(region, _) => {
6576 accumulator.push(*region)
6578 ty_trait(ref t) => {
6579 accumulator.push_all(t.principal.0.substs.regions().as_slice());
6581 ty_enum(_, substs) |
6582 ty_struct(_, substs) => {
6583 accum_substs(accumulator, substs);
6585 ty_unboxed_closure(_, region, substs) => {
6586 accumulator.push(*region);
6587 accum_substs(accumulator, substs);
6609 fn accum_substs(accumulator: &mut Vec<Region>, substs: &Substs) {
6610 match substs.regions {
6611 subst::ErasedRegions => {}
6612 subst::NonerasedRegions(ref regions) => {
6613 for region in regions.iter() {
6614 accumulator.push(*region)
6621 /// A free variable referred to in a function.
6622 #[derive(Copy, RustcEncodable, RustcDecodable)]
6623 pub struct Freevar {
6624 /// The variable being accessed free.
6627 // First span where it is accessed (there can be multiple).
6631 pub type FreevarMap = NodeMap<Vec<Freevar>>;
6633 pub type CaptureModeMap = NodeMap<ast::CaptureClause>;
6635 // Trait method resolution
6636 pub type TraitMap = NodeMap<Vec<DefId>>;
6638 // Map from the NodeId of a glob import to a list of items which are actually
6640 pub type GlobMap = HashMap<NodeId, HashSet<Name>>;
6642 pub fn with_freevars<T, F>(tcx: &ty::ctxt, fid: ast::NodeId, f: F) -> T where
6643 F: FnOnce(&[Freevar]) -> T,
6645 match tcx.freevars.borrow().get(&fid) {
6651 impl<'tcx> AutoAdjustment<'tcx> {
6652 pub fn is_identity(&self) -> bool {
6654 AdjustReifyFnPointer(..) => false,
6655 AdjustDerefRef(ref r) => r.is_identity(),
6660 impl<'tcx> AutoDerefRef<'tcx> {
6661 pub fn is_identity(&self) -> bool {
6662 self.autoderefs == 0 && self.autoref.is_none()
6666 /// Replace any late-bound regions bound in `value` with free variants attached to scope-id
6668 pub fn liberate_late_bound_regions<'tcx, T>(
6669 tcx: &ty::ctxt<'tcx>,
6670 scope: region::CodeExtent,
6673 where T : TypeFoldable<'tcx> + Repr<'tcx>
6675 replace_late_bound_regions(
6677 |br, _| ty::ReFree(ty::FreeRegion{scope: scope, bound_region: br})).0
6680 pub fn count_late_bound_regions<'tcx, T>(
6681 tcx: &ty::ctxt<'tcx>,
6684 where T : TypeFoldable<'tcx> + Repr<'tcx>
6686 let (_, skol_map) = replace_late_bound_regions(tcx, value, |_, _| ty::ReStatic);
6690 pub fn binds_late_bound_regions<'tcx, T>(
6691 tcx: &ty::ctxt<'tcx>,
6694 where T : TypeFoldable<'tcx> + Repr<'tcx>
6696 count_late_bound_regions(tcx, value) > 0
6699 /// Replace any late-bound regions bound in `value` with `'static`. Useful in trans but also
6700 /// method lookup and a few other places where precise region relationships are not required.
6701 pub fn erase_late_bound_regions<'tcx, T>(
6702 tcx: &ty::ctxt<'tcx>,
6705 where T : TypeFoldable<'tcx> + Repr<'tcx>
6707 replace_late_bound_regions(tcx, value, |_, _| ty::ReStatic).0
6710 /// Rewrite any late-bound regions so that they are anonymous. Region numbers are
6711 /// assigned starting at 1 and increasing monotonically in the order traversed
6712 /// by the fold operation.
6714 /// The chief purpose of this function is to canonicalize regions so that two
6715 /// `FnSig`s or `TraitRef`s which are equivalent up to region naming will become
6716 /// structurally identical. For example, `for<'a, 'b> fn(&'a int, &'b int)` and
6717 /// `for<'a, 'b> fn(&'b int, &'a int)` will become identical after anonymization.
6718 pub fn anonymize_late_bound_regions<'tcx, T>(
6722 where T : TypeFoldable<'tcx> + Repr<'tcx>,
6724 let mut counter = 0;
6725 replace_late_bound_regions(tcx, sig, |_, db| {
6727 ReLateBound(db, BrAnon(counter))
6731 /// Replaces the late-bound-regions in `value` that are bound by `value`.
6732 pub fn replace_late_bound_regions<'tcx, T, F>(
6733 tcx: &ty::ctxt<'tcx>,
6736 -> (T, FnvHashMap<ty::BoundRegion,ty::Region>)
6737 where T : TypeFoldable<'tcx> + Repr<'tcx>,
6738 F : FnMut(BoundRegion, DebruijnIndex) -> ty::Region,
6740 debug!("replace_late_bound_regions({})", binder.repr(tcx));
6742 let mut map = FnvHashMap::new();
6744 // Note: fold the field `0`, not the binder, so that late-bound
6745 // regions bound by `binder` are considered free.
6746 let value = ty_fold::fold_regions(tcx, &binder.0, |region, current_depth| {
6747 debug!("region={}", region.repr(tcx));
6749 ty::ReLateBound(debruijn, br) if debruijn.depth == current_depth => {
6750 * map.entry(&br).get().unwrap_or_else(
6751 |vacant_entry| vacant_entry.insert(mapf(br, debruijn)))
6759 debug!("resulting map: {} value: {}", map, value.repr(tcx));
6763 impl DebruijnIndex {
6764 pub fn new(depth: u32) -> DebruijnIndex {
6766 DebruijnIndex { depth: depth }
6769 pub fn shifted(&self, amount: u32) -> DebruijnIndex {
6770 DebruijnIndex { depth: self.depth + amount }
6774 impl<'tcx> Repr<'tcx> for AutoAdjustment<'tcx> {
6775 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6777 AdjustReifyFnPointer(def_id) => {
6778 format!("AdjustReifyFnPointer({})", def_id.repr(tcx))
6780 AdjustDerefRef(ref data) => {
6787 impl<'tcx> Repr<'tcx> for UnsizeKind<'tcx> {
6788 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6790 UnsizeLength(n) => format!("UnsizeLength({})", n),
6791 UnsizeStruct(ref k, n) => format!("UnsizeStruct({},{})", k.repr(tcx), n),
6792 UnsizeVtable(ref a, ref b) => format!("UnsizeVtable({},{})", a.repr(tcx), b.repr(tcx)),
6797 impl<'tcx> Repr<'tcx> for AutoDerefRef<'tcx> {
6798 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6799 format!("AutoDerefRef({}, {})", self.autoderefs, self.autoref.repr(tcx))
6803 impl<'tcx> Repr<'tcx> for AutoRef<'tcx> {
6804 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6806 AutoPtr(a, b, ref c) => {
6807 format!("AutoPtr({},{},{})", a.repr(tcx), b, c.repr(tcx))
6809 AutoUnsize(ref a) => {
6810 format!("AutoUnsize({})", a.repr(tcx))
6812 AutoUnsizeUniq(ref a) => {
6813 format!("AutoUnsizeUniq({})", a.repr(tcx))
6815 AutoUnsafe(ref a, ref b) => {
6816 format!("AutoUnsafe({},{})", a, b.repr(tcx))
6822 impl<'tcx> Repr<'tcx> for TyTrait<'tcx> {
6823 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6824 format!("TyTrait({},{})",
6825 self.principal.repr(tcx),
6826 self.bounds.repr(tcx))
6830 impl<'tcx> Repr<'tcx> for ty::Predicate<'tcx> {
6831 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
6833 Predicate::Trait(ref a) => a.repr(tcx),
6834 Predicate::Equate(ref pair) => pair.repr(tcx),
6835 Predicate::RegionOutlives(ref pair) => pair.repr(tcx),
6836 Predicate::TypeOutlives(ref pair) => pair.repr(tcx),
6837 Predicate::Projection(ref pair) => pair.repr(tcx),
6842 impl<'tcx> Repr<'tcx> for vtable_origin<'tcx> {
6843 fn repr(&self, tcx: &ty::ctxt<'tcx>) -> String {
6845 vtable_static(def_id, ref tys, ref vtable_res) => {
6846 format!("vtable_static({}:{}, {}, {})",
6848 ty::item_path_str(tcx, def_id),
6850 vtable_res.repr(tcx))
6853 vtable_param(x, y) => {
6854 format!("vtable_param({}, {})", x, y)
6857 vtable_unboxed_closure(def_id) => {
6858 format!("vtable_unboxed_closure({})", def_id)
6862 format!("vtable_error")
6868 pub fn make_substs_for_receiver_types<'tcx>(tcx: &ty::ctxt<'tcx>,
6869 trait_ref: &ty::TraitRef<'tcx>,
6870 method: &ty::Method<'tcx>)
6871 -> subst::Substs<'tcx>
6874 * Substitutes the values for the receiver's type parameters
6875 * that are found in method, leaving the method's type parameters
6879 let meth_tps: Vec<Ty> =
6880 method.generics.types.get_slice(subst::FnSpace)
6882 .map(|def| ty::mk_param_from_def(tcx, def))
6884 let meth_regions: Vec<ty::Region> =
6885 method.generics.regions.get_slice(subst::FnSpace)
6887 .map(|def| ty::ReEarlyBound(def.def_id.node, def.space,
6888 def.index, def.name))
6890 trait_ref.substs.clone().with_method(meth_tps, meth_regions)
6894 pub enum CopyImplementationError {
6895 FieldDoesNotImplementCopy(ast::Name),
6896 VariantDoesNotImplementCopy(ast::Name),
6900 pub fn can_type_implement_copy<'a,'tcx>(param_env: &ParameterEnvironment<'a, 'tcx>,
6902 self_type: Ty<'tcx>)
6903 -> Result<(),CopyImplementationError>
6905 let tcx = param_env.tcx;
6907 match self_type.sty {
6908 ty::ty_struct(struct_did, substs) => {
6909 let fields = ty::struct_fields(tcx, struct_did, substs);
6910 for field in fields.iter() {
6911 if type_moves_by_default(param_env, span, field.mt.ty) {
6912 return Err(FieldDoesNotImplementCopy(field.name))
6916 ty::ty_enum(enum_did, substs) => {
6917 let enum_variants = ty::enum_variants(tcx, enum_did);
6918 for variant in enum_variants.iter() {
6919 for variant_arg_type in variant.args.iter() {
6920 let substd_arg_type =
6921 variant_arg_type.subst(tcx, substs);
6922 if type_moves_by_default(param_env, span, substd_arg_type) {
6923 return Err(VariantDoesNotImplementCopy(variant.name))
6928 _ => return Err(TypeIsStructural),
6934 // FIXME(#20298) -- all of these types basically walk various
6935 // structures to test whether types/regions are reachable with various
6936 // properties. It should be possible to express them in terms of one
6937 // common "walker" trait or something.
6939 pub trait RegionEscape {
6940 fn has_escaping_regions(&self) -> bool {
6941 self.has_regions_escaping_depth(0)
6944 fn has_regions_escaping_depth(&self, depth: u32) -> bool;
6947 impl<'tcx> RegionEscape for Ty<'tcx> {
6948 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6949 ty::type_escapes_depth(*self, depth)
6953 impl<'tcx,T:RegionEscape> RegionEscape for VecPerParamSpace<T> {
6954 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6955 self.iter_enumerated().any(|(space, _, t)| {
6956 if space == subst::FnSpace {
6957 t.has_regions_escaping_depth(depth+1)
6959 t.has_regions_escaping_depth(depth)
6965 impl<'tcx> RegionEscape for TypeScheme<'tcx> {
6966 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6967 self.ty.has_regions_escaping_depth(depth) ||
6968 self.generics.has_regions_escaping_depth(depth)
6972 impl RegionEscape for Region {
6973 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6974 self.escapes_depth(depth)
6978 impl<'tcx> RegionEscape for Generics<'tcx> {
6979 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6980 self.predicates.has_regions_escaping_depth(depth)
6984 impl<'tcx> RegionEscape for Predicate<'tcx> {
6985 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6987 Predicate::Trait(ref data) => data.has_regions_escaping_depth(depth),
6988 Predicate::Equate(ref data) => data.has_regions_escaping_depth(depth),
6989 Predicate::RegionOutlives(ref data) => data.has_regions_escaping_depth(depth),
6990 Predicate::TypeOutlives(ref data) => data.has_regions_escaping_depth(depth),
6991 Predicate::Projection(ref data) => data.has_regions_escaping_depth(depth),
6996 impl<'tcx> RegionEscape for TraitRef<'tcx> {
6997 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
6998 self.substs.types.iter().any(|t| t.has_regions_escaping_depth(depth)) ||
6999 self.substs.regions.has_regions_escaping_depth(depth)
7003 impl<'tcx> RegionEscape for subst::RegionSubsts {
7004 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7006 subst::ErasedRegions => false,
7007 subst::NonerasedRegions(ref r) => {
7008 r.iter().any(|t| t.has_regions_escaping_depth(depth))
7014 impl<'tcx,T:RegionEscape> RegionEscape for Binder<T> {
7015 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7016 self.0.has_regions_escaping_depth(depth + 1)
7020 impl<'tcx> RegionEscape for EquatePredicate<'tcx> {
7021 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7022 self.0.has_regions_escaping_depth(depth) || self.1.has_regions_escaping_depth(depth)
7026 impl<'tcx> RegionEscape for TraitPredicate<'tcx> {
7027 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7028 self.trait_ref.has_regions_escaping_depth(depth)
7032 impl<T:RegionEscape,U:RegionEscape> RegionEscape for OutlivesPredicate<T,U> {
7033 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7034 self.0.has_regions_escaping_depth(depth) || self.1.has_regions_escaping_depth(depth)
7038 impl<'tcx> RegionEscape for ProjectionPredicate<'tcx> {
7039 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7040 self.projection_ty.has_regions_escaping_depth(depth) ||
7041 self.ty.has_regions_escaping_depth(depth)
7045 impl<'tcx> RegionEscape for ProjectionTy<'tcx> {
7046 fn has_regions_escaping_depth(&self, depth: u32) -> bool {
7047 self.trait_ref.has_regions_escaping_depth(depth)
7051 impl<'tcx> Repr<'tcx> for ty::ProjectionPredicate<'tcx> {
7052 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7053 format!("ProjectionPredicate({}, {})",
7054 self.projection_ty.repr(tcx),
7059 pub trait HasProjectionTypes {
7060 fn has_projection_types(&self) -> bool;
7063 impl<'tcx,T:HasProjectionTypes> HasProjectionTypes for Vec<T> {
7064 fn has_projection_types(&self) -> bool {
7065 self.iter().any(|p| p.has_projection_types())
7069 impl<'tcx,T:HasProjectionTypes> HasProjectionTypes for VecPerParamSpace<T> {
7070 fn has_projection_types(&self) -> bool {
7071 self.iter().any(|p| p.has_projection_types())
7075 impl<'tcx> HasProjectionTypes for ClosureTy<'tcx> {
7076 fn has_projection_types(&self) -> bool {
7077 self.sig.has_projection_types()
7081 impl<'tcx> HasProjectionTypes for UnboxedClosureUpvar<'tcx> {
7082 fn has_projection_types(&self) -> bool {
7083 self.ty.has_projection_types()
7087 impl<'tcx> HasProjectionTypes for ty::GenericBounds<'tcx> {
7088 fn has_projection_types(&self) -> bool {
7089 self.predicates.has_projection_types()
7093 impl<'tcx> HasProjectionTypes for Predicate<'tcx> {
7094 fn has_projection_types(&self) -> bool {
7096 Predicate::Trait(ref data) => data.has_projection_types(),
7097 Predicate::Equate(ref data) => data.has_projection_types(),
7098 Predicate::RegionOutlives(ref data) => data.has_projection_types(),
7099 Predicate::TypeOutlives(ref data) => data.has_projection_types(),
7100 Predicate::Projection(ref data) => data.has_projection_types(),
7105 impl<'tcx> HasProjectionTypes for TraitPredicate<'tcx> {
7106 fn has_projection_types(&self) -> bool {
7107 self.trait_ref.has_projection_types()
7111 impl<'tcx> HasProjectionTypes for EquatePredicate<'tcx> {
7112 fn has_projection_types(&self) -> bool {
7113 self.0.has_projection_types() || self.1.has_projection_types()
7117 impl HasProjectionTypes for Region {
7118 fn has_projection_types(&self) -> bool {
7123 impl<T:HasProjectionTypes,U:HasProjectionTypes> HasProjectionTypes for OutlivesPredicate<T,U> {
7124 fn has_projection_types(&self) -> bool {
7125 self.0.has_projection_types() || self.1.has_projection_types()
7129 impl<'tcx> HasProjectionTypes for ProjectionPredicate<'tcx> {
7130 fn has_projection_types(&self) -> bool {
7131 self.projection_ty.has_projection_types() || self.ty.has_projection_types()
7135 impl<'tcx> HasProjectionTypes for ProjectionTy<'tcx> {
7136 fn has_projection_types(&self) -> bool {
7137 self.trait_ref.has_projection_types()
7141 impl<'tcx> HasProjectionTypes for Ty<'tcx> {
7142 fn has_projection_types(&self) -> bool {
7143 ty::type_has_projection(*self)
7147 impl<'tcx> HasProjectionTypes for TraitRef<'tcx> {
7148 fn has_projection_types(&self) -> bool {
7149 self.substs.has_projection_types()
7153 impl<'tcx> HasProjectionTypes for subst::Substs<'tcx> {
7154 fn has_projection_types(&self) -> bool {
7155 self.types.iter().any(|t| t.has_projection_types())
7159 impl<'tcx,T> HasProjectionTypes for Option<T>
7160 where T : HasProjectionTypes
7162 fn has_projection_types(&self) -> bool {
7163 self.iter().any(|t| t.has_projection_types())
7167 impl<'tcx,T> HasProjectionTypes for Rc<T>
7168 where T : HasProjectionTypes
7170 fn has_projection_types(&self) -> bool {
7171 (**self).has_projection_types()
7175 impl<'tcx,T> HasProjectionTypes for Box<T>
7176 where T : HasProjectionTypes
7178 fn has_projection_types(&self) -> bool {
7179 (**self).has_projection_types()
7183 impl<T> HasProjectionTypes for Binder<T>
7184 where T : HasProjectionTypes
7186 fn has_projection_types(&self) -> bool {
7187 self.0.has_projection_types()
7191 impl<'tcx> HasProjectionTypes for FnOutput<'tcx> {
7192 fn has_projection_types(&self) -> bool {
7194 FnConverging(t) => t.has_projection_types(),
7195 FnDiverging => false,
7200 impl<'tcx> HasProjectionTypes for FnSig<'tcx> {
7201 fn has_projection_types(&self) -> bool {
7202 self.inputs.iter().any(|t| t.has_projection_types()) ||
7203 self.output.has_projection_types()
7207 impl<'tcx> HasProjectionTypes for BareFnTy<'tcx> {
7208 fn has_projection_types(&self) -> bool {
7209 self.sig.has_projection_types()
7213 pub trait ReferencesError {
7214 fn references_error(&self) -> bool;
7217 impl<T:ReferencesError> ReferencesError for Binder<T> {
7218 fn references_error(&self) -> bool {
7219 self.0.references_error()
7223 impl<T:ReferencesError> ReferencesError for Rc<T> {
7224 fn references_error(&self) -> bool {
7225 (&**self).references_error()
7229 impl<'tcx> ReferencesError for TraitPredicate<'tcx> {
7230 fn references_error(&self) -> bool {
7231 self.trait_ref.references_error()
7235 impl<'tcx> ReferencesError for ProjectionPredicate<'tcx> {
7236 fn references_error(&self) -> bool {
7237 self.projection_ty.trait_ref.references_error() || self.ty.references_error()
7241 impl<'tcx> ReferencesError for TraitRef<'tcx> {
7242 fn references_error(&self) -> bool {
7243 self.input_types().iter().any(|t| t.references_error())
7247 impl<'tcx> ReferencesError for Ty<'tcx> {
7248 fn references_error(&self) -> bool {
7249 type_is_error(*self)
7253 impl<'tcx> ReferencesError for Predicate<'tcx> {
7254 fn references_error(&self) -> bool {
7256 Predicate::Trait(ref data) => data.references_error(),
7257 Predicate::Equate(ref data) => data.references_error(),
7258 Predicate::RegionOutlives(ref data) => data.references_error(),
7259 Predicate::TypeOutlives(ref data) => data.references_error(),
7260 Predicate::Projection(ref data) => data.references_error(),
7265 impl<A,B> ReferencesError for OutlivesPredicate<A,B>
7266 where A : ReferencesError, B : ReferencesError
7268 fn references_error(&self) -> bool {
7269 self.0.references_error() || self.1.references_error()
7273 impl<'tcx> ReferencesError for EquatePredicate<'tcx>
7275 fn references_error(&self) -> bool {
7276 self.0.references_error() || self.1.references_error()
7280 impl ReferencesError for Region
7282 fn references_error(&self) -> bool {
7287 impl<'tcx> Repr<'tcx> for ClosureTy<'tcx> {
7288 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7289 format!("ClosureTy({},{},{},{},{},{})",
7293 self.bounds.repr(tcx),
7299 impl<'tcx> Repr<'tcx> for UnboxedClosureUpvar<'tcx> {
7300 fn repr(&self, tcx: &ctxt<'tcx>) -> String {
7301 format!("UnboxedClosureUpvar({},{})",