1 // ignore-tidy-filelength
2 pub use self::fold
::{TypeFoldable, TypeFolder, TypeVisitor}
;
3 pub use self::AssocItemContainer
::*;
4 pub use self::BorrowKind
::*;
5 pub use self::IntVarValue
::*;
6 pub use self::Variance
::*;
8 use crate::hir
::exports
::ExportMap
;
9 use crate::ich
::StableHashingContext
;
10 use crate::infer
::canonical
::Canonical
;
11 use crate::middle
::cstore
::CrateStoreDyn
;
12 use crate::middle
::resolve_lifetime
::ObjectLifetimeDefault
;
13 use crate::mir
::interpret
::ErrorHandled
;
15 use crate::mir
::GeneratorLayout
;
16 use crate::traits
::{self, Reveal}
;
18 use crate::ty
::subst
::{GenericArg, InternalSubsts, Subst, SubstsRef}
;
19 use crate::ty
::util
::{Discr, IntTypeExt}
;
21 use rustc_attr
as attr
;
22 use rustc_data_structures
::captures
::Captures
;
23 use rustc_data_structures
::fingerprint
::Fingerprint
;
24 use rustc_data_structures
::fx
::FxHashMap
;
25 use rustc_data_structures
::fx
::FxHashSet
;
26 use rustc_data_structures
::fx
::FxIndexMap
;
27 use rustc_data_structures
::sorted_map
::SortedIndexMultiMap
;
28 use rustc_data_structures
::stable_hasher
::{HashStable, StableHasher}
;
29 use rustc_data_structures
::sync
::{self, par_iter, ParallelIterator}
;
30 use rustc_data_structures
::tagged_ptr
::CopyTaggedPtr
;
31 use rustc_errors
::ErrorReported
;
33 use rustc_hir
::def
::{CtorKind, CtorOf, DefKind, Namespace, Res}
;
34 use rustc_hir
::def_id
::{CrateNum, DefId, DefIdMap, LocalDefId, CRATE_DEF_INDEX}
;
35 use rustc_hir
::lang_items
::LangItem
;
36 use rustc_hir
::{Constness, Node}
;
37 use rustc_index
::vec
::{Idx, IndexVec}
;
38 use rustc_macros
::HashStable
;
39 use rustc_serialize
::{self, Encodable, Encoder}
;
40 use rustc_session
::DataTypeKind
;
41 use rustc_span
::hygiene
::ExpnId
;
42 use rustc_span
::symbol
::{kw, sym, Ident, Symbol}
;
44 use rustc_target
::abi
::{Align, VariantIdx}
;
46 use std
::cell
::RefCell
;
47 use std
::cmp
::Ordering
;
49 use std
::hash
::{Hash, Hasher}
;
54 pub use self::sty
::BoundRegion
::*;
55 pub use self::sty
::InferTy
::*;
56 pub use self::sty
::RegionKind
;
57 pub use self::sty
::RegionKind
::*;
58 pub use self::sty
::TyKind
::*;
59 pub use self::sty
::{Binder, BoundTy, BoundTyKind, BoundVar, DebruijnIndex, INNERMOST}
;
60 pub use self::sty
::{BoundRegion, EarlyBoundRegion, FreeRegion, Region}
;
61 pub use self::sty
::{CanonicalPolyFnSig, FnSig, GenSig, PolyFnSig, PolyGenSig}
;
62 pub use self::sty
::{ClosureSubsts, GeneratorSubsts, TypeAndMut, UpvarSubsts}
;
63 pub use self::sty
::{ClosureSubstsParts, GeneratorSubstsParts}
;
64 pub use self::sty
::{ConstVid, FloatVid, IntVid, RegionVid, TyVid}
;
65 pub use self::sty
::{ExistentialPredicate, InferTy, ParamConst, ParamTy, ProjectionTy}
;
66 pub use self::sty
::{ExistentialProjection, PolyExistentialProjection}
;
67 pub use self::sty
::{ExistentialTraitRef, PolyExistentialTraitRef}
;
68 pub use self::sty
::{PolyTraitRef, TraitRef, TyKind}
;
69 pub use crate::ty
::diagnostics
::*;
71 pub use self::binding
::BindingMode
;
72 pub use self::binding
::BindingMode
::*;
74 pub use self::context
::{tls, FreeRegionInfo, TyCtxt}
;
75 pub use self::context
::{
76 CanonicalUserType
, CanonicalUserTypeAnnotation
, CanonicalUserTypeAnnotations
,
77 DelaySpanBugEmitted
, ResolvedOpaqueTy
, UserType
, UserTypeAnnotationIndex
,
79 pub use self::context
::{
80 CtxtInterners
, GeneratorInteriorTypeCause
, GlobalCtxt
, Lift
, TypeckResults
,
83 pub use self::instance
::{Instance, InstanceDef}
;
85 pub use self::list
::List
;
87 pub use self::trait_def
::TraitDef
;
89 pub use self::query
::queries
;
91 pub use self::consts
::{Const, ConstInt, ConstKind, InferConst}
;
103 pub mod inhabitedness
;
105 pub mod normalize_erasing_regions
;
121 mod structural_impls
;
126 pub struct ResolverOutputs
{
127 pub definitions
: rustc_hir
::definitions
::Definitions
,
128 pub cstore
: Box
<CrateStoreDyn
>,
129 pub extern_crate_map
: FxHashMap
<LocalDefId
, CrateNum
>,
130 pub maybe_unused_trait_imports
: FxHashSet
<LocalDefId
>,
131 pub maybe_unused_extern_crates
: Vec
<(LocalDefId
, Span
)>,
132 pub export_map
: ExportMap
<LocalDefId
>,
133 pub glob_map
: FxHashMap
<LocalDefId
, FxHashSet
<Symbol
>>,
134 /// Extern prelude entries. The value is `true` if the entry was introduced
135 /// via `extern crate` item and not `--extern` option or compiler built-in.
136 pub extern_prelude
: FxHashMap
<Symbol
, bool
>,
139 #[derive(Clone, Copy, PartialEq, Eq, Debug, HashStable, Hash)]
140 pub enum AssocItemContainer
{
141 TraitContainer(DefId
),
142 ImplContainer(DefId
),
145 impl AssocItemContainer
{
146 /// Asserts that this is the `DefId` of an associated item declared
147 /// in a trait, and returns the trait `DefId`.
148 pub fn assert_trait(&self) -> DefId
{
150 TraitContainer(id
) => id
,
151 _
=> bug
!("associated item has wrong container type: {:?}", self),
155 pub fn id(&self) -> DefId
{
157 TraitContainer(id
) => id
,
158 ImplContainer(id
) => id
,
163 /// The "header" of an impl is everything outside the body: a Self type, a trait
164 /// ref (in the case of a trait impl), and a set of predicates (from the
165 /// bounds / where-clauses).
166 #[derive(Clone, Debug, TypeFoldable)]
167 pub struct ImplHeader
<'tcx
> {
168 pub impl_def_id
: DefId
,
169 pub self_ty
: Ty
<'tcx
>,
170 pub trait_ref
: Option
<TraitRef
<'tcx
>>,
171 pub predicates
: Vec
<Predicate
<'tcx
>>,
174 #[derive(Copy, Clone, PartialEq, TyEncodable, TyDecodable, HashStable)]
175 pub enum ImplPolarity
{
176 /// `impl Trait for Type`
178 /// `impl !Trait for Type`
180 /// `#[rustc_reservation_impl] impl Trait for Type`
182 /// This is a "stability hack", not a real Rust feature.
183 /// See #64631 for details.
187 #[derive(Copy, Clone, Debug, PartialEq, HashStable, Eq, Hash)]
188 pub struct AssocItem
{
190 #[stable_hasher(project(name))]
194 pub defaultness
: hir
::Defaultness
,
195 pub container
: AssocItemContainer
,
197 /// Whether this is a method with an explicit self
198 /// as its first parameter, allowing method calls.
199 pub fn_has_self_parameter
: bool
,
202 #[derive(Copy, Clone, PartialEq, Debug, HashStable, Eq, Hash)]
210 pub fn namespace(&self) -> Namespace
{
212 ty
::AssocKind
::Type
=> Namespace
::TypeNS
,
213 ty
::AssocKind
::Const
| ty
::AssocKind
::Fn
=> Namespace
::ValueNS
,
217 pub fn as_def_kind(&self) -> DefKind
{
219 AssocKind
::Const
=> DefKind
::AssocConst
,
220 AssocKind
::Fn
=> DefKind
::AssocFn
,
221 AssocKind
::Type
=> DefKind
::AssocTy
,
227 pub fn signature(&self, tcx
: TyCtxt
<'_
>) -> String
{
229 ty
::AssocKind
::Fn
=> {
230 // We skip the binder here because the binder would deanonymize all
231 // late-bound regions, and we don't want method signatures to show up
232 // `as for<'r> fn(&'r MyType)`. Pretty-printing handles late-bound
233 // regions just fine, showing `fn(&MyType)`.
234 tcx
.fn_sig(self.def_id
).skip_binder().to_string()
236 ty
::AssocKind
::Type
=> format
!("type {};", self.ident
),
237 ty
::AssocKind
::Const
=> {
238 format
!("const {}: {:?};", self.ident
, tcx
.type_of(self.def_id
))
244 /// A list of `ty::AssocItem`s in definition order that allows for efficient lookup by name.
246 /// When doing lookup by name, we try to postpone hygienic comparison for as long as possible since
247 /// it is relatively expensive. Instead, items are indexed by `Symbol` and hygienic comparison is
248 /// done only on items with the same name.
249 #[derive(Debug, Clone, PartialEq, HashStable)]
250 pub struct AssociatedItems
<'tcx
> {
251 items
: SortedIndexMultiMap
<u32, Symbol
, &'tcx ty
::AssocItem
>,
254 impl<'tcx
> AssociatedItems
<'tcx
> {
255 /// Constructs an `AssociatedItems` map from a series of `ty::AssocItem`s in definition order.
256 pub fn new(items_in_def_order
: impl IntoIterator
<Item
= &'tcx ty
::AssocItem
>) -> Self {
257 let items
= items_in_def_order
.into_iter().map(|item
| (item
.ident
.name
, item
)).collect();
258 AssociatedItems { items }
261 /// Returns a slice of associated items in the order they were defined.
263 /// New code should avoid relying on definition order. If you need a particular associated item
264 /// for a known trait, make that trait a lang item instead of indexing this array.
265 pub fn in_definition_order(&self) -> impl '_
+ Iterator
<Item
= &ty
::AssocItem
> {
266 self.items
.iter().map(|(_
, v
)| *v
)
269 /// Returns an iterator over all associated items with the given name, ignoring hygiene.
270 pub fn filter_by_name_unhygienic(
273 ) -> impl '_
+ Iterator
<Item
= &ty
::AssocItem
> {
274 self.items
.get_by_key(&name
).copied()
277 /// Returns an iterator over all associated items with the given name.
279 /// Multiple items may have the same name if they are in different `Namespace`s. For example,
280 /// an associated type can have the same name as a method. Use one of the `find_by_name_and_*`
281 /// methods below if you know which item you are looking for.
282 pub fn filter_by_name(
286 parent_def_id
: DefId
,
287 ) -> impl 'a
+ Iterator
<Item
= &'a ty
::AssocItem
> {
288 self.filter_by_name_unhygienic(ident
.name
)
289 .filter(move |item
| tcx
.hygienic_eq(ident
, item
.ident
, parent_def_id
))
292 /// Returns the associated item with the given name and `AssocKind`, if one exists.
293 pub fn find_by_name_and_kind(
298 parent_def_id
: DefId
,
299 ) -> Option
<&ty
::AssocItem
> {
300 self.filter_by_name_unhygienic(ident
.name
)
301 .filter(|item
| item
.kind
== kind
)
302 .find(|item
| tcx
.hygienic_eq(ident
, item
.ident
, parent_def_id
))
305 /// Returns the associated item with the given name in the given `Namespace`, if one exists.
306 pub fn find_by_name_and_namespace(
311 parent_def_id
: DefId
,
312 ) -> Option
<&ty
::AssocItem
> {
313 self.filter_by_name_unhygienic(ident
.name
)
314 .filter(|item
| item
.kind
.namespace() == ns
)
315 .find(|item
| tcx
.hygienic_eq(ident
, item
.ident
, parent_def_id
))
319 #[derive(Clone, Debug, PartialEq, Eq, Copy, Hash, TyEncodable, TyDecodable, HashStable)]
320 pub enum Visibility
{
321 /// Visible everywhere (including in other crates).
323 /// Visible only in the given crate-local module.
325 /// Not visible anywhere in the local crate. This is the visibility of private external items.
329 pub trait DefIdTree
: Copy
{
330 fn parent(self, id
: DefId
) -> Option
<DefId
>;
332 fn is_descendant_of(self, mut descendant
: DefId
, ancestor
: DefId
) -> bool
{
333 if descendant
.krate
!= ancestor
.krate
{
337 while descendant
!= ancestor
{
338 match self.parent(descendant
) {
339 Some(parent
) => descendant
= parent
,
340 None
=> return false,
347 impl<'tcx
> DefIdTree
for TyCtxt
<'tcx
> {
348 fn parent(self, id
: DefId
) -> Option
<DefId
> {
349 self.def_key(id
).parent
.map(|index
| DefId { index, ..id }
)
354 pub fn from_hir(visibility
: &hir
::Visibility
<'_
>, id
: hir
::HirId
, tcx
: TyCtxt
<'_
>) -> Self {
355 match visibility
.node
{
356 hir
::VisibilityKind
::Public
=> Visibility
::Public
,
357 hir
::VisibilityKind
::Crate(_
) => Visibility
::Restricted(DefId
::local(CRATE_DEF_INDEX
)),
358 hir
::VisibilityKind
::Restricted { ref path, .. }
=> match path
.res
{
359 // If there is no resolution, `resolve` will have already reported an error, so
360 // assume that the visibility is public to avoid reporting more privacy errors.
361 Res
::Err
=> Visibility
::Public
,
362 def
=> Visibility
::Restricted(def
.def_id()),
364 hir
::VisibilityKind
::Inherited
=> {
365 Visibility
::Restricted(tcx
.parent_module(id
).to_def_id())
370 /// Returns `true` if an item with this visibility is accessible from the given block.
371 pub fn is_accessible_from
<T
: DefIdTree
>(self, module
: DefId
, tree
: T
) -> bool
{
372 let restriction
= match self {
373 // Public items are visible everywhere.
374 Visibility
::Public
=> return true,
375 // Private items from other crates are visible nowhere.
376 Visibility
::Invisible
=> return false,
377 // Restricted items are visible in an arbitrary local module.
378 Visibility
::Restricted(other
) if other
.krate
!= module
.krate
=> return false,
379 Visibility
::Restricted(module
) => module
,
382 tree
.is_descendant_of(module
, restriction
)
385 /// Returns `true` if this visibility is at least as accessible as the given visibility
386 pub fn is_at_least
<T
: DefIdTree
>(self, vis
: Visibility
, tree
: T
) -> bool
{
387 let vis_restriction
= match vis
{
388 Visibility
::Public
=> return self == Visibility
::Public
,
389 Visibility
::Invisible
=> return true,
390 Visibility
::Restricted(module
) => module
,
393 self.is_accessible_from(vis_restriction
, tree
)
396 // Returns `true` if this item is visible anywhere in the local crate.
397 pub fn is_visible_locally(self) -> bool
{
399 Visibility
::Public
=> true,
400 Visibility
::Restricted(def_id
) => def_id
.is_local(),
401 Visibility
::Invisible
=> false,
406 #[derive(Copy, Clone, PartialEq, TyDecodable, TyEncodable, HashStable)]
408 Covariant
, // T<A> <: T<B> iff A <: B -- e.g., function return type
409 Invariant
, // T<A> <: T<B> iff B == A -- e.g., type of mutable cell
410 Contravariant
, // T<A> <: T<B> iff B <: A -- e.g., function param type
411 Bivariant
, // T<A> <: T<B> -- e.g., unused type parameter
414 /// The crate variances map is computed during typeck and contains the
415 /// variance of every item in the local crate. You should not use it
416 /// directly, because to do so will make your pass dependent on the
417 /// HIR of every item in the local crate. Instead, use
418 /// `tcx.variances_of()` to get the variance for a *particular*
420 #[derive(HashStable)]
421 pub struct CrateVariancesMap
<'tcx
> {
422 /// For each item with generics, maps to a vector of the variance
423 /// of its generics. If an item has no generics, it will have no
425 pub variances
: FxHashMap
<DefId
, &'tcx
[ty
::Variance
]>,
429 /// `a.xform(b)` combines the variance of a context with the
430 /// variance of a type with the following meaning. If we are in a
431 /// context with variance `a`, and we encounter a type argument in
432 /// a position with variance `b`, then `a.xform(b)` is the new
433 /// variance with which the argument appears.
439 /// Here, the "ambient" variance starts as covariant. `*mut T` is
440 /// invariant with respect to `T`, so the variance in which the
441 /// `Vec<i32>` appears is `Covariant.xform(Invariant)`, which
442 /// yields `Invariant`. Now, the type `Vec<T>` is covariant with
443 /// respect to its type argument `T`, and hence the variance of
444 /// the `i32` here is `Invariant.xform(Covariant)`, which results
445 /// (again) in `Invariant`.
449 /// fn(*const Vec<i32>, *mut Vec<i32)
451 /// The ambient variance is covariant. A `fn` type is
452 /// contravariant with respect to its parameters, so the variance
453 /// within which both pointer types appear is
454 /// `Covariant.xform(Contravariant)`, or `Contravariant`. `*const
455 /// T` is covariant with respect to `T`, so the variance within
456 /// which the first `Vec<i32>` appears is
457 /// `Contravariant.xform(Covariant)` or `Contravariant`. The same
458 /// is true for its `i32` argument. In the `*mut T` case, the
459 /// variance of `Vec<i32>` is `Contravariant.xform(Invariant)`,
460 /// and hence the outermost type is `Invariant` with respect to
461 /// `Vec<i32>` (and its `i32` argument).
463 /// Source: Figure 1 of "Taming the Wildcards:
464 /// Combining Definition- and Use-Site Variance" published in PLDI'11.
465 pub fn xform(self, v
: ty
::Variance
) -> ty
::Variance
{
467 // Figure 1, column 1.
468 (ty
::Covariant
, ty
::Covariant
) => ty
::Covariant
,
469 (ty
::Covariant
, ty
::Contravariant
) => ty
::Contravariant
,
470 (ty
::Covariant
, ty
::Invariant
) => ty
::Invariant
,
471 (ty
::Covariant
, ty
::Bivariant
) => ty
::Bivariant
,
473 // Figure 1, column 2.
474 (ty
::Contravariant
, ty
::Covariant
) => ty
::Contravariant
,
475 (ty
::Contravariant
, ty
::Contravariant
) => ty
::Covariant
,
476 (ty
::Contravariant
, ty
::Invariant
) => ty
::Invariant
,
477 (ty
::Contravariant
, ty
::Bivariant
) => ty
::Bivariant
,
479 // Figure 1, column 3.
480 (ty
::Invariant
, _
) => ty
::Invariant
,
482 // Figure 1, column 4.
483 (ty
::Bivariant
, _
) => ty
::Bivariant
,
488 // Contains information needed to resolve types and (in the future) look up
489 // the types of AST nodes.
490 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
491 pub struct CReaderCacheKey
{
497 /// Flags that we track on types. These flags are propagated upwards
498 /// through the type during type construction, so that we can quickly check
499 /// whether the type has various kinds of types in it without recursing
500 /// over the type itself.
501 pub struct TypeFlags
: u32 {
502 // Does this have parameters? Used to determine whether substitution is
504 /// Does this have [Param]?
505 const HAS_TY_PARAM
= 1 << 0;
506 /// Does this have [ReEarlyBound]?
507 const HAS_RE_PARAM
= 1 << 1;
508 /// Does this have [ConstKind::Param]?
509 const HAS_CT_PARAM
= 1 << 2;
511 const NEEDS_SUBST
= TypeFlags
::HAS_TY_PARAM
.bits
512 | TypeFlags
::HAS_RE_PARAM
.bits
513 | TypeFlags
::HAS_CT_PARAM
.bits
;
515 /// Does this have [Infer]?
516 const HAS_TY_INFER
= 1 << 3;
517 /// Does this have [ReVar]?
518 const HAS_RE_INFER
= 1 << 4;
519 /// Does this have [ConstKind::Infer]?
520 const HAS_CT_INFER
= 1 << 5;
522 /// Does this have inference variables? Used to determine whether
523 /// inference is required.
524 const NEEDS_INFER
= TypeFlags
::HAS_TY_INFER
.bits
525 | TypeFlags
::HAS_RE_INFER
.bits
526 | TypeFlags
::HAS_CT_INFER
.bits
;
528 /// Does this have [Placeholder]?
529 const HAS_TY_PLACEHOLDER
= 1 << 6;
530 /// Does this have [RePlaceholder]?
531 const HAS_RE_PLACEHOLDER
= 1 << 7;
532 /// Does this have [ConstKind::Placeholder]?
533 const HAS_CT_PLACEHOLDER
= 1 << 8;
535 /// `true` if there are "names" of regions and so forth
536 /// that are local to a particular fn/inferctxt
537 const HAS_FREE_LOCAL_REGIONS
= 1 << 9;
539 /// `true` if there are "names" of types and regions and so forth
540 /// that are local to a particular fn
541 const HAS_FREE_LOCAL_NAMES
= TypeFlags
::HAS_TY_PARAM
.bits
542 | TypeFlags
::HAS_CT_PARAM
.bits
543 | TypeFlags
::HAS_TY_INFER
.bits
544 | TypeFlags
::HAS_CT_INFER
.bits
545 | TypeFlags
::HAS_TY_PLACEHOLDER
.bits
546 | TypeFlags
::HAS_CT_PLACEHOLDER
.bits
547 | TypeFlags
::HAS_FREE_LOCAL_REGIONS
.bits
;
549 /// Does this have [Projection]?
550 const HAS_TY_PROJECTION
= 1 << 10;
551 /// Does this have [Opaque]?
552 const HAS_TY_OPAQUE
= 1 << 11;
553 /// Does this have [ConstKind::Unevaluated]?
554 const HAS_CT_PROJECTION
= 1 << 12;
556 /// Could this type be normalized further?
557 const HAS_PROJECTION
= TypeFlags
::HAS_TY_PROJECTION
.bits
558 | TypeFlags
::HAS_TY_OPAQUE
.bits
559 | TypeFlags
::HAS_CT_PROJECTION
.bits
;
561 /// Is an error type/const reachable?
562 const HAS_ERROR
= 1 << 13;
564 /// Does this have any region that "appears free" in the type?
565 /// Basically anything but [ReLateBound] and [ReErased].
566 const HAS_FREE_REGIONS
= 1 << 14;
568 /// Does this have any [ReLateBound] regions? Used to check
569 /// if a global bound is safe to evaluate.
570 const HAS_RE_LATE_BOUND
= 1 << 15;
572 /// Does this have any [ReErased] regions?
573 const HAS_RE_ERASED
= 1 << 16;
575 /// Does this value have parameters/placeholders/inference variables which could be
576 /// replaced later, in a way that would change the results of `impl` specialization?
577 const STILL_FURTHER_SPECIALIZABLE
= 1 << 17;
581 #[allow(rustc::usage_of_ty_tykind)]
582 pub struct TyS
<'tcx
> {
583 /// This field shouldn't be used directly and may be removed in the future.
584 /// Use `TyS::kind()` instead.
586 /// This field shouldn't be used directly and may be removed in the future.
587 /// Use `TyS::flags()` instead.
590 /// This is a kind of confusing thing: it stores the smallest
593 /// (a) the binder itself captures nothing but
594 /// (b) all the late-bound things within the type are captured
595 /// by some sub-binder.
597 /// So, for a type without any late-bound things, like `u32`, this
598 /// will be *innermost*, because that is the innermost binder that
599 /// captures nothing. But for a type `&'D u32`, where `'D` is a
600 /// late-bound region with De Bruijn index `D`, this would be `D + 1`
601 /// -- the binder itself does not capture `D`, but `D` is captured
602 /// by an inner binder.
604 /// We call this concept an "exclusive" binder `D` because all
605 /// De Bruijn indices within the type are contained within `0..D`
607 outer_exclusive_binder
: ty
::DebruijnIndex
,
610 // `TyS` is used a lot. Make sure it doesn't unintentionally get bigger.
611 #[cfg(target_arch = "x86_64")]
612 static_assert_size
!(TyS
<'_
>, 32);
614 impl<'tcx
> Ord
for TyS
<'tcx
> {
615 fn cmp(&self, other
: &TyS
<'tcx
>) -> Ordering
{
616 self.kind().cmp(other
.kind())
620 impl<'tcx
> PartialOrd
for TyS
<'tcx
> {
621 fn partial_cmp(&self, other
: &TyS
<'tcx
>) -> Option
<Ordering
> {
622 Some(self.kind().cmp(other
.kind()))
626 impl<'tcx
> PartialEq
for TyS
<'tcx
> {
628 fn eq(&self, other
: &TyS
<'tcx
>) -> bool
{
632 impl<'tcx
> Eq
for TyS
<'tcx
> {}
634 impl<'tcx
> Hash
for TyS
<'tcx
> {
635 fn hash
<H
: Hasher
>(&self, s
: &mut H
) {
636 (self as *const TyS
<'_
>).hash(s
)
640 impl<'a
, 'tcx
> HashStable
<StableHashingContext
<'a
>> for TyS
<'tcx
> {
641 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
645 // The other fields just provide fast access to information that is
646 // also contained in `kind`, so no need to hash them.
649 outer_exclusive_binder
: _
,
652 kind
.hash_stable(hcx
, hasher
);
656 #[rustc_diagnostic_item = "Ty"]
657 pub type Ty
<'tcx
> = &'tcx TyS
<'tcx
>;
659 pub type CanonicalTy
<'tcx
> = Canonical
<'tcx
, Ty
<'tcx
>>;
661 #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable, HashStable)]
662 pub struct UpvarPath
{
663 pub hir_id
: hir
::HirId
,
666 /// Upvars do not get their own `NodeId`. Instead, we use the pair of
667 /// the original var ID (that is, the root variable that is referenced
668 /// by the upvar) and the ID of the closure expression.
669 #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable, HashStable)]
671 pub var_path
: UpvarPath
,
672 pub closure_expr_id
: LocalDefId
,
675 #[derive(Clone, PartialEq, Debug, TyEncodable, TyDecodable, Copy, HashStable)]
676 pub enum BorrowKind
{
677 /// Data must be immutable and is aliasable.
680 /// Data must be immutable but not aliasable. This kind of borrow
681 /// cannot currently be expressed by the user and is used only in
682 /// implicit closure bindings. It is needed when the closure
683 /// is borrowing or mutating a mutable referent, e.g.:
686 /// let x: &mut isize = ...;
687 /// let y = || *x += 5;
690 /// If we were to try to translate this closure into a more explicit
691 /// form, we'd encounter an error with the code as written:
694 /// struct Env { x: & &mut isize }
695 /// let x: &mut isize = ...;
696 /// let y = (&mut Env { &x }, fn_ptr); // Closure is pair of env and fn
697 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
700 /// This is then illegal because you cannot mutate a `&mut` found
701 /// in an aliasable location. To solve, you'd have to translate with
702 /// an `&mut` borrow:
705 /// struct Env { x: & &mut isize }
706 /// let x: &mut isize = ...;
707 /// let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x
708 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
711 /// Now the assignment to `**env.x` is legal, but creating a
712 /// mutable pointer to `x` is not because `x` is not mutable. We
713 /// could fix this by declaring `x` as `let mut x`. This is ok in
714 /// user code, if awkward, but extra weird for closures, since the
715 /// borrow is hidden.
717 /// So we introduce a "unique imm" borrow -- the referent is
718 /// immutable, but not aliasable. This solves the problem. For
719 /// simplicity, we don't give users the way to express this
720 /// borrow, it's just used when translating closures.
723 /// Data is mutable and not aliasable.
727 /// Information describing the capture of an upvar. This is computed
728 /// during `typeck`, specifically by `regionck`.
729 #[derive(PartialEq, Clone, Debug, Copy, TyEncodable, TyDecodable, HashStable)]
730 pub enum UpvarCapture
<'tcx
> {
731 /// Upvar is captured by value. This is always true when the
732 /// closure is labeled `move`, but can also be true in other cases
733 /// depending on inference.
735 /// If the upvar was inferred to be captured by value (e.g. `move`
736 /// was not used), then the `Span` points to a usage that
737 /// required it. There may be more than one such usage
738 /// (e.g. `|| { a; a; }`), in which case we pick an
740 ByValue(Option
<Span
>),
742 /// Upvar is captured by reference.
743 ByRef(UpvarBorrow
<'tcx
>),
746 #[derive(PartialEq, Clone, Copy, TyEncodable, TyDecodable, HashStable)]
747 pub struct UpvarBorrow
<'tcx
> {
748 /// The kind of borrow: by-ref upvars have access to shared
749 /// immutable borrows, which are not part of the normal language
751 pub kind
: BorrowKind
,
753 /// Region of the resulting reference.
754 pub region
: ty
::Region
<'tcx
>,
757 pub type UpvarListMap
= FxHashMap
<DefId
, FxIndexMap
<hir
::HirId
, UpvarId
>>;
758 pub type UpvarCaptureMap
<'tcx
> = FxHashMap
<UpvarId
, UpvarCapture
<'tcx
>>;
760 #[derive(Clone, Copy, PartialEq, Eq)]
761 pub enum IntVarValue
{
763 UintType(ast
::UintTy
),
766 #[derive(Clone, Copy, PartialEq, Eq)]
767 pub struct FloatVarValue(pub ast
::FloatTy
);
769 impl ty
::EarlyBoundRegion
{
770 pub fn to_bound_region(&self) -> ty
::BoundRegion
{
771 ty
::BoundRegion
::BrNamed(self.def_id
, self.name
)
774 /// Does this early bound region have a name? Early bound regions normally
775 /// always have names except when using anonymous lifetimes (`'_`).
776 pub fn has_name(&self) -> bool
{
777 self.name
!= kw
::UnderscoreLifetime
781 #[derive(Clone, Debug, TyEncodable, TyDecodable, HashStable)]
782 pub enum GenericParamDefKind
{
786 object_lifetime_default
: ObjectLifetimeDefault
,
787 synthetic
: Option
<hir
::SyntheticTyParamKind
>,
792 impl GenericParamDefKind
{
793 pub fn descr(&self) -> &'
static str {
795 GenericParamDefKind
::Lifetime
=> "lifetime",
796 GenericParamDefKind
::Type { .. }
=> "type",
797 GenericParamDefKind
::Const
=> "constant",
802 #[derive(Clone, Debug, TyEncodable, TyDecodable, HashStable)]
803 pub struct GenericParamDef
{
808 /// `pure_wrt_drop`, set by the (unsafe) `#[may_dangle]` attribute
809 /// on generic parameter `'a`/`T`, asserts data behind the parameter
810 /// `'a`/`T` won't be accessed during the parent type's `Drop` impl.
811 pub pure_wrt_drop
: bool
,
813 pub kind
: GenericParamDefKind
,
816 impl GenericParamDef
{
817 pub fn to_early_bound_region_data(&self) -> ty
::EarlyBoundRegion
{
818 if let GenericParamDefKind
::Lifetime
= self.kind
{
819 ty
::EarlyBoundRegion { def_id: self.def_id, index: self.index, name: self.name }
821 bug
!("cannot convert a non-lifetime parameter def to an early bound region")
825 pub fn to_bound_region(&self) -> ty
::BoundRegion
{
826 if let GenericParamDefKind
::Lifetime
= self.kind
{
827 self.to_early_bound_region_data().to_bound_region()
829 bug
!("cannot convert a non-lifetime parameter def to an early bound region")
835 pub struct GenericParamCount
{
836 pub lifetimes
: usize,
841 /// Information about the formal type/lifetime parameters associated
842 /// with an item or method. Analogous to `hir::Generics`.
844 /// The ordering of parameters is the same as in `Subst` (excluding child generics):
845 /// `Self` (optionally), `Lifetime` params..., `Type` params...
846 #[derive(Clone, Debug, TyEncodable, TyDecodable, HashStable)]
847 pub struct Generics
{
848 pub parent
: Option
<DefId
>,
849 pub parent_count
: usize,
850 pub params
: Vec
<GenericParamDef
>,
852 /// Reverse map to the `index` field of each `GenericParamDef`.
853 #[stable_hasher(ignore)]
854 pub param_def_id_to_index
: FxHashMap
<DefId
, u32>,
857 pub has_late_bound_regions
: Option
<Span
>,
860 impl<'tcx
> Generics
{
861 pub fn count(&self) -> usize {
862 self.parent_count
+ self.params
.len()
865 pub fn own_counts(&self) -> GenericParamCount
{
866 // We could cache this as a property of `GenericParamCount`, but
867 // the aim is to refactor this away entirely eventually and the
868 // presence of this method will be a constant reminder.
869 let mut own_counts
: GenericParamCount
= Default
::default();
871 for param
in &self.params
{
873 GenericParamDefKind
::Lifetime
=> own_counts
.lifetimes
+= 1,
874 GenericParamDefKind
::Type { .. }
=> own_counts
.types
+= 1,
875 GenericParamDefKind
::Const
=> own_counts
.consts
+= 1,
882 pub fn requires_monomorphization(&self, tcx
: TyCtxt
<'tcx
>) -> bool
{
883 if self.own_requires_monomorphization() {
887 if let Some(parent_def_id
) = self.parent
{
888 let parent
= tcx
.generics_of(parent_def_id
);
889 parent
.requires_monomorphization(tcx
)
895 pub fn own_requires_monomorphization(&self) -> bool
{
896 for param
in &self.params
{
898 GenericParamDefKind
::Type { .. }
| GenericParamDefKind
::Const
=> return true,
899 GenericParamDefKind
::Lifetime
=> {}
905 /// Returns the `GenericParamDef` with the given index.
906 pub fn param_at(&'tcx
self, param_index
: usize, tcx
: TyCtxt
<'tcx
>) -> &'tcx GenericParamDef
{
907 if let Some(index
) = param_index
.checked_sub(self.parent_count
) {
910 tcx
.generics_of(self.parent
.expect("parent_count > 0 but no parent?"))
911 .param_at(param_index
, tcx
)
915 /// Returns the `GenericParamDef` associated with this `EarlyBoundRegion`.
918 param
: &EarlyBoundRegion
,
920 ) -> &'tcx GenericParamDef
{
921 let param
= self.param_at(param
.index
as usize, tcx
);
923 GenericParamDefKind
::Lifetime
=> param
,
924 _
=> bug
!("expected lifetime parameter, but found another generic parameter"),
928 /// Returns the `GenericParamDef` associated with this `ParamTy`.
929 pub fn type_param(&'tcx
self, param
: &ParamTy
, tcx
: TyCtxt
<'tcx
>) -> &'tcx GenericParamDef
{
930 let param
= self.param_at(param
.index
as usize, tcx
);
932 GenericParamDefKind
::Type { .. }
=> param
,
933 _
=> bug
!("expected type parameter, but found another generic parameter"),
937 /// Returns the `GenericParamDef` associated with this `ParamConst`.
938 pub fn const_param(&'tcx
self, param
: &ParamConst
, tcx
: TyCtxt
<'tcx
>) -> &GenericParamDef
{
939 let param
= self.param_at(param
.index
as usize, tcx
);
941 GenericParamDefKind
::Const
=> param
,
942 _
=> bug
!("expected const parameter, but found another generic parameter"),
947 /// Bounds on generics.
948 #[derive(Copy, Clone, Default, Debug, TyEncodable, TyDecodable, HashStable)]
949 pub struct GenericPredicates
<'tcx
> {
950 pub parent
: Option
<DefId
>,
951 pub predicates
: &'tcx
[(Predicate
<'tcx
>, Span
)],
954 impl<'tcx
> GenericPredicates
<'tcx
> {
958 substs
: SubstsRef
<'tcx
>,
959 ) -> InstantiatedPredicates
<'tcx
> {
960 let mut instantiated
= InstantiatedPredicates
::empty();
961 self.instantiate_into(tcx
, &mut instantiated
, substs
);
965 pub fn instantiate_own(
968 substs
: SubstsRef
<'tcx
>,
969 ) -> InstantiatedPredicates
<'tcx
> {
970 InstantiatedPredicates
{
971 predicates
: self.predicates
.iter().map(|(p
, _
)| p
.subst(tcx
, substs
)).collect(),
972 spans
: self.predicates
.iter().map(|(_
, sp
)| *sp
).collect(),
979 instantiated
: &mut InstantiatedPredicates
<'tcx
>,
980 substs
: SubstsRef
<'tcx
>,
982 if let Some(def_id
) = self.parent
{
983 tcx
.predicates_of(def_id
).instantiate_into(tcx
, instantiated
, substs
);
985 instantiated
.predicates
.extend(self.predicates
.iter().map(|(p
, _
)| p
.subst(tcx
, substs
)));
986 instantiated
.spans
.extend(self.predicates
.iter().map(|(_
, sp
)| *sp
));
989 pub fn instantiate_identity(&self, tcx
: TyCtxt
<'tcx
>) -> InstantiatedPredicates
<'tcx
> {
990 let mut instantiated
= InstantiatedPredicates
::empty();
991 self.instantiate_identity_into(tcx
, &mut instantiated
);
995 fn instantiate_identity_into(
998 instantiated
: &mut InstantiatedPredicates
<'tcx
>,
1000 if let Some(def_id
) = self.parent
{
1001 tcx
.predicates_of(def_id
).instantiate_identity_into(tcx
, instantiated
);
1003 instantiated
.predicates
.extend(self.predicates
.iter().map(|(p
, _
)| p
));
1004 instantiated
.spans
.extend(self.predicates
.iter().map(|(_
, s
)| s
));
1007 pub fn instantiate_supertrait(
1010 poly_trait_ref
: &ty
::PolyTraitRef
<'tcx
>,
1011 ) -> InstantiatedPredicates
<'tcx
> {
1012 assert_eq
!(self.parent
, None
);
1013 InstantiatedPredicates
{
1017 .map(|(pred
, _
)| pred
.subst_supertrait(tcx
, poly_trait_ref
))
1019 spans
: self.predicates
.iter().map(|(_
, sp
)| *sp
).collect(),
1025 crate struct PredicateInner
<'tcx
> {
1026 kind
: PredicateKind
<'tcx
>,
1028 /// See the comment for the corresponding field of [TyS].
1029 outer_exclusive_binder
: ty
::DebruijnIndex
,
1032 #[cfg(target_arch = "x86_64")]
1033 static_assert_size
!(PredicateInner
<'_
>, 48);
1035 #[derive(Clone, Copy, Lift)]
1036 pub struct Predicate
<'tcx
> {
1037 inner
: &'tcx PredicateInner
<'tcx
>,
1040 impl<'tcx
> PartialEq
for Predicate
<'tcx
> {
1041 fn eq(&self, other
: &Self) -> bool
{
1042 // `self.kind` is always interned.
1043 ptr
::eq(self.inner
, other
.inner
)
1047 impl Hash
for Predicate
<'_
> {
1048 fn hash
<H
: Hasher
>(&self, s
: &mut H
) {
1049 (self.inner
as *const PredicateInner
<'_
>).hash(s
)
1053 impl<'tcx
> Eq
for Predicate
<'tcx
> {}
1055 impl<'tcx
> Predicate
<'tcx
> {
1057 pub fn kind(self) -> &'tcx PredicateKind
<'tcx
> {
1061 /// Returns the inner `PredicateAtom`.
1063 /// The returned atom may contain unbound variables bound to binders skipped in this method.
1064 /// It is safe to reapply binders to the given atom.
1066 /// Note that this method panics in case this predicate has unbound variables.
1067 pub fn skip_binders(self) -> PredicateAtom
<'tcx
> {
1069 &PredicateKind
::ForAll(binder
) => binder
.skip_binder(),
1070 &PredicateKind
::Atom(atom
) => {
1071 debug_assert
!(!atom
.has_escaping_bound_vars());
1077 /// Returns the inner `PredicateAtom`.
1079 /// Note that this method does not check if the predicate has unbound variables.
1081 /// Rebinding the returned atom can causes the previously bound variables
1082 /// to end up at the wrong binding level.
1083 pub fn skip_binders_unchecked(self) -> PredicateAtom
<'tcx
> {
1085 &PredicateKind
::ForAll(binder
) => binder
.skip_binder(),
1086 &PredicateKind
::Atom(atom
) => atom
,
1090 /// Allows using a `Binder<PredicateAtom<'tcx>>` even if the given predicate previously
1091 /// contained unbound variables by shifting these variables outwards.
1092 pub fn bound_atom(self, tcx
: TyCtxt
<'tcx
>) -> Binder
<PredicateAtom
<'tcx
>> {
1094 &PredicateKind
::ForAll(binder
) => binder
,
1095 &PredicateKind
::Atom(atom
) => Binder
::wrap_nonbinding(tcx
, atom
),
1100 impl<'a
, 'tcx
> HashStable
<StableHashingContext
<'a
>> for Predicate
<'tcx
> {
1101 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
1102 let PredicateInner
{
1105 // The other fields just provide fast access to information that is
1106 // also contained in `kind`, so no need to hash them.
1108 outer_exclusive_binder
: _
,
1111 kind
.hash_stable(hcx
, hasher
);
1115 #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)]
1116 #[derive(HashStable, TypeFoldable)]
1117 pub enum PredicateKind
<'tcx
> {
1119 ForAll(Binder
<PredicateAtom
<'tcx
>>),
1120 Atom(PredicateAtom
<'tcx
>),
1123 #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)]
1124 #[derive(HashStable, TypeFoldable)]
1125 pub enum PredicateAtom
<'tcx
> {
1126 /// Corresponds to `where Foo: Bar<A, B, C>`. `Foo` here would be
1127 /// the `Self` type of the trait reference and `A`, `B`, and `C`
1128 /// would be the type parameters.
1130 /// A trait predicate will have `Constness::Const` if it originates
1131 /// from a bound on a `const fn` without the `?const` opt-out (e.g.,
1132 /// `const fn foobar<Foo: Bar>() {}`).
1133 Trait(TraitPredicate
<'tcx
>, Constness
),
1136 RegionOutlives(RegionOutlivesPredicate
<'tcx
>),
1139 TypeOutlives(TypeOutlivesPredicate
<'tcx
>),
1141 /// `where <T as TraitRef>::Name == X`, approximately.
1142 /// See the `ProjectionPredicate` struct for details.
1143 Projection(ProjectionPredicate
<'tcx
>),
1145 /// No syntax: `T` well-formed.
1146 WellFormed(GenericArg
<'tcx
>),
1148 /// Trait must be object-safe.
1151 /// No direct syntax. May be thought of as `where T: FnFoo<...>`
1152 /// for some substitutions `...` and `T` being a closure type.
1153 /// Satisfied (or refuted) once we know the closure's kind.
1154 ClosureKind(DefId
, SubstsRef
<'tcx
>, ClosureKind
),
1157 Subtype(SubtypePredicate
<'tcx
>),
1159 /// Constant initializer must evaluate successfully.
1160 ConstEvaluatable(ty
::WithOptConstParam
<DefId
>, SubstsRef
<'tcx
>),
1162 /// Constants must be equal. The first component is the const that is expected.
1163 ConstEquate(&'tcx Const
<'tcx
>, &'tcx Const
<'tcx
>),
1165 /// Represents a type found in the environment that we can use for implied bounds.
1167 /// Only used for Chalk.
1168 TypeWellFormedFromEnv(Ty
<'tcx
>),
1171 impl<'tcx
> PredicateAtom
<'tcx
> {
1172 /// Wraps `self` with the given qualifier if this predicate has any unbound variables.
1173 pub fn potentially_quantified(
1176 qualifier
: impl FnOnce(Binder
<PredicateAtom
<'tcx
>>) -> PredicateKind
<'tcx
>,
1177 ) -> Predicate
<'tcx
> {
1178 if self.has_escaping_bound_vars() {
1179 qualifier(Binder
::bind(self))
1181 PredicateKind
::Atom(self)
1187 /// The crate outlives map is computed during typeck and contains the
1188 /// outlives of every item in the local crate. You should not use it
1189 /// directly, because to do so will make your pass dependent on the
1190 /// HIR of every item in the local crate. Instead, use
1191 /// `tcx.inferred_outlives_of()` to get the outlives for a *particular*
1193 #[derive(HashStable)]
1194 pub struct CratePredicatesMap
<'tcx
> {
1195 /// For each struct with outlive bounds, maps to a vector of the
1196 /// predicate of its outlive bounds. If an item has no outlives
1197 /// bounds, it will have no entry.
1198 pub predicates
: FxHashMap
<DefId
, &'tcx
[(Predicate
<'tcx
>, Span
)]>,
1201 impl<'tcx
> Predicate
<'tcx
> {
1202 /// Performs a substitution suitable for going from a
1203 /// poly-trait-ref to supertraits that must hold if that
1204 /// poly-trait-ref holds. This is slightly different from a normal
1205 /// substitution in terms of what happens with bound regions. See
1206 /// lengthy comment below for details.
1207 pub fn subst_supertrait(
1210 trait_ref
: &ty
::PolyTraitRef
<'tcx
>,
1211 ) -> Predicate
<'tcx
> {
1212 // The interaction between HRTB and supertraits is not entirely
1213 // obvious. Let me walk you (and myself) through an example.
1215 // Let's start with an easy case. Consider two traits:
1217 // trait Foo<'a>: Bar<'a,'a> { }
1218 // trait Bar<'b,'c> { }
1220 // Now, if we have a trait reference `for<'x> T: Foo<'x>`, then
1221 // we can deduce that `for<'x> T: Bar<'x,'x>`. Basically, if we
1222 // knew that `Foo<'x>` (for any 'x) then we also know that
1223 // `Bar<'x,'x>` (for any 'x). This more-or-less falls out from
1224 // normal substitution.
1226 // In terms of why this is sound, the idea is that whenever there
1227 // is an impl of `T:Foo<'a>`, it must show that `T:Bar<'a,'a>`
1228 // holds. So if there is an impl of `T:Foo<'a>` that applies to
1229 // all `'a`, then we must know that `T:Bar<'a,'a>` holds for all
1232 // Another example to be careful of is this:
1234 // trait Foo1<'a>: for<'b> Bar1<'a,'b> { }
1235 // trait Bar1<'b,'c> { }
1237 // Here, if we have `for<'x> T: Foo1<'x>`, then what do we know?
1238 // The answer is that we know `for<'x,'b> T: Bar1<'x,'b>`. The
1239 // reason is similar to the previous example: any impl of
1240 // `T:Foo1<'x>` must show that `for<'b> T: Bar1<'x, 'b>`. So
1241 // basically we would want to collapse the bound lifetimes from
1242 // the input (`trait_ref`) and the supertraits.
1244 // To achieve this in practice is fairly straightforward. Let's
1245 // consider the more complicated scenario:
1247 // - We start out with `for<'x> T: Foo1<'x>`. In this case, `'x`
1248 // has a De Bruijn index of 1. We want to produce `for<'x,'b> T: Bar1<'x,'b>`,
1249 // where both `'x` and `'b` would have a DB index of 1.
1250 // The substitution from the input trait-ref is therefore going to be
1251 // `'a => 'x` (where `'x` has a DB index of 1).
1252 // - The super-trait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an
1253 // early-bound parameter and `'b' is a late-bound parameter with a
1255 // - If we replace `'a` with `'x` from the input, it too will have
1256 // a DB index of 1, and thus we'll have `for<'x,'b> Bar1<'x,'b>`
1257 // just as we wanted.
1259 // There is only one catch. If we just apply the substitution `'a
1260 // => 'x` to `for<'b> Bar1<'a,'b>`, the substitution code will
1261 // adjust the DB index because we substituting into a binder (it
1262 // tries to be so smart...) resulting in `for<'x> for<'b>
1263 // Bar1<'x,'b>` (we have no syntax for this, so use your
1264 // imagination). Basically the 'x will have DB index of 2 and 'b
1265 // will have DB index of 1. Not quite what we want. So we apply
1266 // the substitution to the *contents* of the trait reference,
1267 // rather than the trait reference itself (put another way, the
1268 // substitution code expects equal binding levels in the values
1269 // from the substitution and the value being substituted into, and
1270 // this trick achieves that).
1271 let substs
= trait_ref
.skip_binder().substs
;
1272 let pred
= self.skip_binders();
1273 let new
= pred
.subst(tcx
, substs
);
1274 if new
!= pred { new.potentially_quantified(tcx, PredicateKind::ForAll) }
else { self }
1278 #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)]
1279 #[derive(HashStable, TypeFoldable)]
1280 pub struct TraitPredicate
<'tcx
> {
1281 pub trait_ref
: TraitRef
<'tcx
>,
1284 pub type PolyTraitPredicate
<'tcx
> = ty
::Binder
<TraitPredicate
<'tcx
>>;
1286 impl<'tcx
> TraitPredicate
<'tcx
> {
1287 pub fn def_id(self) -> DefId
{
1288 self.trait_ref
.def_id
1291 pub fn self_ty(self) -> Ty
<'tcx
> {
1292 self.trait_ref
.self_ty()
1296 impl<'tcx
> PolyTraitPredicate
<'tcx
> {
1297 pub fn def_id(self) -> DefId
{
1298 // Ok to skip binder since trait `DefId` does not care about regions.
1299 self.skip_binder().def_id()
1303 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, TyEncodable, TyDecodable)]
1304 #[derive(HashStable, TypeFoldable)]
1305 pub struct OutlivesPredicate
<A
, B
>(pub A
, pub B
); // `A: B`
1306 pub type PolyOutlivesPredicate
<A
, B
> = ty
::Binder
<OutlivesPredicate
<A
, B
>>;
1307 pub type RegionOutlivesPredicate
<'tcx
> = OutlivesPredicate
<ty
::Region
<'tcx
>, ty
::Region
<'tcx
>>;
1308 pub type TypeOutlivesPredicate
<'tcx
> = OutlivesPredicate
<Ty
<'tcx
>, ty
::Region
<'tcx
>>;
1309 pub type PolyRegionOutlivesPredicate
<'tcx
> = ty
::Binder
<RegionOutlivesPredicate
<'tcx
>>;
1310 pub type PolyTypeOutlivesPredicate
<'tcx
> = ty
::Binder
<TypeOutlivesPredicate
<'tcx
>>;
1312 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, TyEncodable, TyDecodable)]
1313 #[derive(HashStable, TypeFoldable)]
1314 pub struct SubtypePredicate
<'tcx
> {
1315 pub a_is_expected
: bool
,
1319 pub type PolySubtypePredicate
<'tcx
> = ty
::Binder
<SubtypePredicate
<'tcx
>>;
1321 /// This kind of predicate has no *direct* correspondent in the
1322 /// syntax, but it roughly corresponds to the syntactic forms:
1324 /// 1. `T: TraitRef<..., Item = Type>`
1325 /// 2. `<T as TraitRef<...>>::Item == Type` (NYI)
1327 /// In particular, form #1 is "desugared" to the combination of a
1328 /// normal trait predicate (`T: TraitRef<...>`) and one of these
1329 /// predicates. Form #2 is a broader form in that it also permits
1330 /// equality between arbitrary types. Processing an instance of
1331 /// Form #2 eventually yields one of these `ProjectionPredicate`
1332 /// instances to normalize the LHS.
1333 #[derive(Copy, Clone, PartialEq, Eq, Hash, TyEncodable, TyDecodable)]
1334 #[derive(HashStable, TypeFoldable)]
1335 pub struct ProjectionPredicate
<'tcx
> {
1336 pub projection_ty
: ProjectionTy
<'tcx
>,
1340 pub type PolyProjectionPredicate
<'tcx
> = Binder
<ProjectionPredicate
<'tcx
>>;
1342 impl<'tcx
> PolyProjectionPredicate
<'tcx
> {
1343 /// Returns the `DefId` of the associated item being projected.
1344 pub fn item_def_id(&self) -> DefId
{
1345 self.skip_binder().projection_ty
.item_def_id
1349 pub fn to_poly_trait_ref(&self, tcx
: TyCtxt
<'tcx
>) -> PolyTraitRef
<'tcx
> {
1350 // Note: unlike with `TraitRef::to_poly_trait_ref()`,
1351 // `self.0.trait_ref` is permitted to have escaping regions.
1352 // This is because here `self` has a `Binder` and so does our
1353 // return value, so we are preserving the number of binding
1355 self.map_bound(|predicate
| predicate
.projection_ty
.trait_ref(tcx
))
1358 pub fn ty(&self) -> Binder
<Ty
<'tcx
>> {
1359 self.map_bound(|predicate
| predicate
.ty
)
1362 /// The `DefId` of the `TraitItem` for the associated type.
1364 /// Note that this is not the `DefId` of the `TraitRef` containing this
1365 /// associated type, which is in `tcx.associated_item(projection_def_id()).container`.
1366 pub fn projection_def_id(&self) -> DefId
{
1367 // Ok to skip binder since trait `DefId` does not care about regions.
1368 self.skip_binder().projection_ty
.item_def_id
1372 pub trait ToPolyTraitRef
<'tcx
> {
1373 fn to_poly_trait_ref(&self) -> PolyTraitRef
<'tcx
>;
1376 impl<'tcx
> ToPolyTraitRef
<'tcx
> for TraitRef
<'tcx
> {
1377 fn to_poly_trait_ref(&self) -> PolyTraitRef
<'tcx
> {
1378 ty
::Binder
::dummy(*self)
1382 impl<'tcx
> ToPolyTraitRef
<'tcx
> for PolyTraitPredicate
<'tcx
> {
1383 fn to_poly_trait_ref(&self) -> PolyTraitRef
<'tcx
> {
1384 self.map_bound_ref(|trait_pred
| trait_pred
.trait_ref
)
1388 pub trait ToPredicate
<'tcx
> {
1389 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
>;
1392 impl ToPredicate
<'tcx
> for PredicateKind
<'tcx
> {
1394 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
1395 tcx
.mk_predicate(self)
1399 impl ToPredicate
<'tcx
> for PredicateAtom
<'tcx
> {
1401 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
1402 debug_assert
!(!self.has_escaping_bound_vars(), "escaping bound vars for {:?}", self);
1403 tcx
.mk_predicate(PredicateKind
::Atom(self))
1407 impl<'tcx
> ToPredicate
<'tcx
> for ConstnessAnd
<TraitRef
<'tcx
>> {
1408 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
1409 PredicateAtom
::Trait(ty
::TraitPredicate { trait_ref: self.value }
, self.constness
)
1414 impl<'tcx
> ToPredicate
<'tcx
> for ConstnessAnd
<PolyTraitRef
<'tcx
>> {
1415 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
1417 value
: self.value
.map_bound(|trait_ref
| ty
::TraitPredicate { trait_ref }
),
1418 constness
: self.constness
,
1424 impl<'tcx
> ToPredicate
<'tcx
> for ConstnessAnd
<PolyTraitPredicate
<'tcx
>> {
1425 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
1426 PredicateAtom
::Trait(self.value
.skip_binder(), self.constness
)
1427 .potentially_quantified(tcx
, PredicateKind
::ForAll
)
1431 impl<'tcx
> ToPredicate
<'tcx
> for PolyRegionOutlivesPredicate
<'tcx
> {
1432 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
1433 PredicateAtom
::RegionOutlives(self.skip_binder())
1434 .potentially_quantified(tcx
, PredicateKind
::ForAll
)
1438 impl<'tcx
> ToPredicate
<'tcx
> for PolyTypeOutlivesPredicate
<'tcx
> {
1439 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
1440 PredicateAtom
::TypeOutlives(self.skip_binder())
1441 .potentially_quantified(tcx
, PredicateKind
::ForAll
)
1445 impl<'tcx
> ToPredicate
<'tcx
> for PolyProjectionPredicate
<'tcx
> {
1446 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
1447 PredicateAtom
::Projection(self.skip_binder())
1448 .potentially_quantified(tcx
, PredicateKind
::ForAll
)
1452 impl<'tcx
> Predicate
<'tcx
> {
1453 pub fn to_opt_poly_trait_ref(self) -> Option
<PolyTraitRef
<'tcx
>> {
1454 match self.skip_binders() {
1455 PredicateAtom
::Trait(t
, _
) => Some(ty
::Binder
::bind(t
.trait_ref
)),
1456 PredicateAtom
::Projection(..)
1457 | PredicateAtom
::Subtype(..)
1458 | PredicateAtom
::RegionOutlives(..)
1459 | PredicateAtom
::WellFormed(..)
1460 | PredicateAtom
::ObjectSafe(..)
1461 | PredicateAtom
::ClosureKind(..)
1462 | PredicateAtom
::TypeOutlives(..)
1463 | PredicateAtom
::ConstEvaluatable(..)
1464 | PredicateAtom
::ConstEquate(..)
1465 | PredicateAtom
::TypeWellFormedFromEnv(..) => None
,
1469 pub fn to_opt_type_outlives(self) -> Option
<PolyTypeOutlivesPredicate
<'tcx
>> {
1470 match self.skip_binders() {
1471 PredicateAtom
::TypeOutlives(data
) => Some(ty
::Binder
::bind(data
)),
1472 PredicateAtom
::Trait(..)
1473 | PredicateAtom
::Projection(..)
1474 | PredicateAtom
::Subtype(..)
1475 | PredicateAtom
::RegionOutlives(..)
1476 | PredicateAtom
::WellFormed(..)
1477 | PredicateAtom
::ObjectSafe(..)
1478 | PredicateAtom
::ClosureKind(..)
1479 | PredicateAtom
::ConstEvaluatable(..)
1480 | PredicateAtom
::ConstEquate(..)
1481 | PredicateAtom
::TypeWellFormedFromEnv(..) => None
,
1486 /// Represents the bounds declared on a particular set of type
1487 /// parameters. Should eventually be generalized into a flag list of
1488 /// where-clauses. You can obtain a `InstantiatedPredicates` list from a
1489 /// `GenericPredicates` by using the `instantiate` method. Note that this method
1490 /// reflects an important semantic invariant of `InstantiatedPredicates`: while
1491 /// the `GenericPredicates` are expressed in terms of the bound type
1492 /// parameters of the impl/trait/whatever, an `InstantiatedPredicates` instance
1493 /// represented a set of bounds for some particular instantiation,
1494 /// meaning that the generic parameters have been substituted with
1499 /// struct Foo<T, U: Bar<T>> { ... }
1501 /// Here, the `GenericPredicates` for `Foo` would contain a list of bounds like
1502 /// `[[], [U:Bar<T>]]`. Now if there were some particular reference
1503 /// like `Foo<isize,usize>`, then the `InstantiatedPredicates` would be `[[],
1504 /// [usize:Bar<isize>]]`.
1505 #[derive(Clone, Debug, TypeFoldable)]
1506 pub struct InstantiatedPredicates
<'tcx
> {
1507 pub predicates
: Vec
<Predicate
<'tcx
>>,
1508 pub spans
: Vec
<Span
>,
1511 impl<'tcx
> InstantiatedPredicates
<'tcx
> {
1512 pub fn empty() -> InstantiatedPredicates
<'tcx
> {
1513 InstantiatedPredicates { predicates: vec![], spans: vec![] }
1516 pub fn is_empty(&self) -> bool
{
1517 self.predicates
.is_empty()
1521 rustc_index
::newtype_index
! {
1522 /// "Universes" are used during type- and trait-checking in the
1523 /// presence of `for<..>` binders to control what sets of names are
1524 /// visible. Universes are arranged into a tree: the root universe
1525 /// contains names that are always visible. Each child then adds a new
1526 /// set of names that are visible, in addition to those of its parent.
1527 /// We say that the child universe "extends" the parent universe with
1530 /// To make this more concrete, consider this program:
1534 /// fn bar<T>(x: T) {
1535 /// let y: for<'a> fn(&'a u8, Foo) = ...;
1539 /// The struct name `Foo` is in the root universe U0. But the type
1540 /// parameter `T`, introduced on `bar`, is in an extended universe U1
1541 /// -- i.e., within `bar`, we can name both `T` and `Foo`, but outside
1542 /// of `bar`, we cannot name `T`. Then, within the type of `y`, the
1543 /// region `'a` is in a universe U2 that extends U1, because we can
1544 /// name it inside the fn type but not outside.
1546 /// Universes are used to do type- and trait-checking around these
1547 /// "forall" binders (also called **universal quantification**). The
1548 /// idea is that when, in the body of `bar`, we refer to `T` as a
1549 /// type, we aren't referring to any type in particular, but rather a
1550 /// kind of "fresh" type that is distinct from all other types we have
1551 /// actually declared. This is called a **placeholder** type, and we
1552 /// use universes to talk about this. In other words, a type name in
1553 /// universe 0 always corresponds to some "ground" type that the user
1554 /// declared, but a type name in a non-zero universe is a placeholder
1555 /// type -- an idealized representative of "types in general" that we
1556 /// use for checking generic functions.
1557 pub struct UniverseIndex
{
1559 DEBUG_FORMAT
= "U{}",
1563 impl UniverseIndex
{
1564 pub const ROOT
: UniverseIndex
= UniverseIndex
::from_u32(0);
1566 /// Returns the "next" universe index in order -- this new index
1567 /// is considered to extend all previous universes. This
1568 /// corresponds to entering a `forall` quantifier. So, for
1569 /// example, suppose we have this type in universe `U`:
1572 /// for<'a> fn(&'a u32)
1575 /// Once we "enter" into this `for<'a>` quantifier, we are in a
1576 /// new universe that extends `U` -- in this new universe, we can
1577 /// name the region `'a`, but that region was not nameable from
1578 /// `U` because it was not in scope there.
1579 pub fn next_universe(self) -> UniverseIndex
{
1580 UniverseIndex
::from_u32(self.private
.checked_add(1).unwrap())
1583 /// Returns `true` if `self` can name a name from `other` -- in other words,
1584 /// if the set of names in `self` is a superset of those in
1585 /// `other` (`self >= other`).
1586 pub fn can_name(self, other
: UniverseIndex
) -> bool
{
1587 self.private
>= other
.private
1590 /// Returns `true` if `self` cannot name some names from `other` -- in other
1591 /// words, if the set of names in `self` is a strict subset of
1592 /// those in `other` (`self < other`).
1593 pub fn cannot_name(self, other
: UniverseIndex
) -> bool
{
1594 self.private
< other
.private
1598 /// The "placeholder index" fully defines a placeholder region.
1599 /// Placeholder regions are identified by both a **universe** as well
1600 /// as a "bound-region" within that universe. The `bound_region` is
1601 /// basically a name -- distinct bound regions within the same
1602 /// universe are just two regions with an unknown relationship to one
1604 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TyEncodable, TyDecodable, PartialOrd, Ord)]
1605 pub struct Placeholder
<T
> {
1606 pub universe
: UniverseIndex
,
1610 impl<'a
, T
> HashStable
<StableHashingContext
<'a
>> for Placeholder
<T
>
1612 T
: HashStable
<StableHashingContext
<'a
>>,
1614 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
1615 self.universe
.hash_stable(hcx
, hasher
);
1616 self.name
.hash_stable(hcx
, hasher
);
1620 pub type PlaceholderRegion
= Placeholder
<BoundRegion
>;
1622 pub type PlaceholderType
= Placeholder
<BoundVar
>;
1624 pub type PlaceholderConst
= Placeholder
<BoundVar
>;
1626 /// A `DefId` which is potentially bundled with its corresponding generic parameter
1627 /// in case `did` is a const argument.
1629 /// This is used to prevent cycle errors during typeck
1630 /// as `type_of(const_arg)` depends on `typeck(owning_body)`
1631 /// which once again requires the type of its generic arguments.
1633 /// Luckily we only need to deal with const arguments once we
1634 /// know their corresponding parameters. We (ab)use this by
1635 /// calling `type_of(param_did)` for these arguments.
1638 /// #![feature(const_generics)]
1642 /// fn foo<const N: usize>(&self) -> usize { N }
1646 /// fn foo<const N: u8>(&self) -> usize { 42 }
1654 #[derive(Copy, Clone, Debug, TypeFoldable, Lift, TyEncodable, TyDecodable)]
1655 #[derive(PartialEq, Eq, PartialOrd, Ord)]
1656 #[derive(Hash, HashStable)]
1657 pub struct WithOptConstParam
<T
> {
1659 /// The `DefId` of the corresponding generic paramter in case `did` is
1660 /// a const argument.
1662 /// Note that even if `did` is a const argument, this may still be `None`.
1663 /// All queries taking `WithOptConstParam` start by calling `tcx.opt_const_param_of(def.did)`
1664 /// to potentially update `param_did` in case it `None`.
1665 pub const_param_did
: Option
<DefId
>,
1668 impl<T
> WithOptConstParam
<T
> {
1669 /// Creates a new `WithOptConstParam` setting `const_param_did` to `None`.
1671 pub fn unknown(did
: T
) -> WithOptConstParam
<T
> {
1672 WithOptConstParam { did, const_param_did: None }
1676 impl WithOptConstParam
<LocalDefId
> {
1677 /// Returns `Some((did, param_did))` if `def_id` is a const argument,
1678 /// `None` otherwise.
1680 pub fn try_lookup(did
: LocalDefId
, tcx
: TyCtxt
<'_
>) -> Option
<(LocalDefId
, DefId
)> {
1681 tcx
.opt_const_param_of(did
).map(|param_did
| (did
, param_did
))
1684 /// In case `self` is unknown but `self.did` is a const argument, this returns
1685 /// a `WithOptConstParam` with the correct `const_param_did`.
1687 pub fn try_upgrade(self, tcx
: TyCtxt
<'_
>) -> Option
<WithOptConstParam
<LocalDefId
>> {
1688 if self.const_param_did
.is_none() {
1689 if let const_param_did @
Some(_
) = tcx
.opt_const_param_of(self.did
) {
1690 return Some(WithOptConstParam { did: self.did, const_param_did }
);
1697 pub fn to_global(self) -> WithOptConstParam
<DefId
> {
1698 WithOptConstParam { did: self.did.to_def_id(), const_param_did: self.const_param_did }
1701 pub fn def_id_for_type_of(self) -> DefId
{
1702 if let Some(did
) = self.const_param_did { did }
else { self.did.to_def_id() }
1706 impl WithOptConstParam
<DefId
> {
1707 pub fn as_local(self) -> Option
<WithOptConstParam
<LocalDefId
>> {
1710 .map(|did
| WithOptConstParam { did, const_param_did: self.const_param_did }
)
1713 pub fn as_const_arg(self) -> Option
<(LocalDefId
, DefId
)> {
1714 if let Some(param_did
) = self.const_param_did
{
1715 if let Some(did
) = self.did
.as_local() {
1716 return Some((did
, param_did
));
1723 pub fn expect_local(self) -> WithOptConstParam
<LocalDefId
> {
1724 self.as_local().unwrap()
1727 pub fn is_local(self) -> bool
{
1731 pub fn def_id_for_type_of(self) -> DefId
{
1732 self.const_param_did
.unwrap_or(self.did
)
1736 /// When type checking, we use the `ParamEnv` to track
1737 /// details about the set of where-clauses that are in scope at this
1738 /// particular point.
1739 #[derive(Copy, Clone, Hash, PartialEq, Eq)]
1740 pub struct ParamEnv
<'tcx
> {
1741 /// This packs both caller bounds and the reveal enum into one pointer.
1743 /// Caller bounds are `Obligation`s that the caller must satisfy. This is
1744 /// basically the set of bounds on the in-scope type parameters, translated
1745 /// into `Obligation`s, and elaborated and normalized.
1747 /// Use the `caller_bounds()` method to access.
1749 /// Typically, this is `Reveal::UserFacing`, but during codegen we
1750 /// want `Reveal::All`.
1752 /// Note: This is packed, use the reveal() method to access it.
1753 packed
: CopyTaggedPtr
<&'tcx List
<Predicate
<'tcx
>>, traits
::Reveal
, true>,
1756 unsafe impl rustc_data_structures
::tagged_ptr
::Tag
for traits
::Reveal
{
1757 const BITS
: usize = 1;
1758 fn into_usize(self) -> usize {
1760 traits
::Reveal
::UserFacing
=> 0,
1761 traits
::Reveal
::All
=> 1,
1764 unsafe fn from_usize(ptr
: usize) -> Self {
1766 0 => traits
::Reveal
::UserFacing
,
1767 1 => traits
::Reveal
::All
,
1768 _
=> std
::hint
::unreachable_unchecked(),
1773 impl<'tcx
> fmt
::Debug
for ParamEnv
<'tcx
> {
1774 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
1775 f
.debug_struct("ParamEnv")
1776 .field("caller_bounds", &self.caller_bounds())
1777 .field("reveal", &self.reveal())
1782 impl<'a
, 'tcx
> HashStable
<StableHashingContext
<'a
>> for ParamEnv
<'tcx
> {
1783 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
1784 self.caller_bounds().hash_stable(hcx
, hasher
);
1785 self.reveal().hash_stable(hcx
, hasher
);
1789 impl<'tcx
> TypeFoldable
<'tcx
> for ParamEnv
<'tcx
> {
1790 fn super_fold_with
<F
: ty
::fold
::TypeFolder
<'tcx
>>(&self, folder
: &mut F
) -> Self {
1791 ParamEnv
::new(self.caller_bounds().fold_with(folder
), self.reveal().fold_with(folder
))
1794 fn super_visit_with
<V
: TypeVisitor
<'tcx
>>(&self, visitor
: &mut V
) -> bool
{
1795 self.caller_bounds().visit_with(visitor
) || self.reveal().visit_with(visitor
)
1799 impl<'tcx
> ParamEnv
<'tcx
> {
1800 /// Construct a trait environment suitable for contexts where
1801 /// there are no where-clauses in scope. Hidden types (like `impl
1802 /// Trait`) are left hidden, so this is suitable for ordinary
1805 pub fn empty() -> Self {
1806 Self::new(List
::empty(), Reveal
::UserFacing
)
1810 pub fn caller_bounds(self) -> &'tcx List
<Predicate
<'tcx
>> {
1811 self.packed
.pointer()
1815 pub fn reveal(self) -> traits
::Reveal
{
1819 /// Construct a trait environment with no where-clauses in scope
1820 /// where the values of all `impl Trait` and other hidden types
1821 /// are revealed. This is suitable for monomorphized, post-typeck
1822 /// environments like codegen or doing optimizations.
1824 /// N.B., if you want to have predicates in scope, use `ParamEnv::new`,
1825 /// or invoke `param_env.with_reveal_all()`.
1827 pub fn reveal_all() -> Self {
1828 Self::new(List
::empty(), Reveal
::All
)
1831 /// Construct a trait environment with the given set of predicates.
1833 pub fn new(caller_bounds
: &'tcx List
<Predicate
<'tcx
>>, reveal
: Reveal
) -> Self {
1834 ty
::ParamEnv { packed: CopyTaggedPtr::new(caller_bounds, reveal) }
1837 pub fn with_user_facing(mut self) -> Self {
1838 self.packed
.set_tag(Reveal
::UserFacing
);
1842 /// Returns a new parameter environment with the same clauses, but
1843 /// which "reveals" the true results of projections in all cases
1844 /// (even for associated types that are specializable). This is
1845 /// the desired behavior during codegen and certain other special
1846 /// contexts; normally though we want to use `Reveal::UserFacing`,
1847 /// which is the default.
1848 /// All opaque types in the caller_bounds of the `ParamEnv`
1849 /// will be normalized to their underlying types.
1850 /// See PR #65989 and issue #65918 for more details
1851 pub fn with_reveal_all_normalized(self, tcx
: TyCtxt
<'tcx
>) -> Self {
1852 if self.packed
.tag() == traits
::Reveal
::All
{
1856 ParamEnv
::new(tcx
.normalize_opaque_types(self.caller_bounds()), Reveal
::All
)
1859 /// Returns this same environment but with no caller bounds.
1860 pub fn without_caller_bounds(self) -> Self {
1861 Self::new(List
::empty(), self.reveal())
1864 /// Creates a suitable environment in which to perform trait
1865 /// queries on the given value. When type-checking, this is simply
1866 /// the pair of the environment plus value. But when reveal is set to
1867 /// All, then if `value` does not reference any type parameters, we will
1868 /// pair it with the empty environment. This improves caching and is generally
1871 /// N.B., we preserve the environment when type-checking because it
1872 /// is possible for the user to have wacky where-clauses like
1873 /// `where Box<u32>: Copy`, which are clearly never
1874 /// satisfiable. We generally want to behave as if they were true,
1875 /// although the surrounding function is never reachable.
1876 pub fn and
<T
: TypeFoldable
<'tcx
>>(self, value
: T
) -> ParamEnvAnd
<'tcx
, T
> {
1877 match self.reveal() {
1878 Reveal
::UserFacing
=> ParamEnvAnd { param_env: self, value }
,
1881 if value
.is_global() {
1882 ParamEnvAnd { param_env: self.without_caller_bounds(), value }
1884 ParamEnvAnd { param_env: self, value }
1891 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
1892 pub struct ConstnessAnd
<T
> {
1893 pub constness
: Constness
,
1897 // FIXME(ecstaticmorse): Audit all occurrences of `without_const().to_predicate(tcx)` to ensure that
1898 // the constness of trait bounds is being propagated correctly.
1899 pub trait WithConstness
: Sized
{
1901 fn with_constness(self, constness
: Constness
) -> ConstnessAnd
<Self> {
1902 ConstnessAnd { constness, value: self }
1906 fn with_const(self) -> ConstnessAnd
<Self> {
1907 self.with_constness(Constness
::Const
)
1911 fn without_const(self) -> ConstnessAnd
<Self> {
1912 self.with_constness(Constness
::NotConst
)
1916 impl<T
> WithConstness
for T {}
1918 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TypeFoldable)]
1919 pub struct ParamEnvAnd
<'tcx
, T
> {
1920 pub param_env
: ParamEnv
<'tcx
>,
1924 impl<'tcx
, T
> ParamEnvAnd
<'tcx
, T
> {
1925 pub fn into_parts(self) -> (ParamEnv
<'tcx
>, T
) {
1926 (self.param_env
, self.value
)
1930 impl<'a
, 'tcx
, T
> HashStable
<StableHashingContext
<'a
>> for ParamEnvAnd
<'tcx
, T
>
1932 T
: HashStable
<StableHashingContext
<'a
>>,
1934 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
1935 let ParamEnvAnd { ref param_env, ref value }
= *self;
1937 param_env
.hash_stable(hcx
, hasher
);
1938 value
.hash_stable(hcx
, hasher
);
1942 #[derive(Copy, Clone, Debug, HashStable)]
1943 pub struct Destructor
{
1944 /// The `DefId` of the destructor method
1949 #[derive(HashStable)]
1950 pub struct AdtFlags
: u32 {
1951 const NO_ADT_FLAGS
= 0;
1952 /// Indicates whether the ADT is an enum.
1953 const IS_ENUM
= 1 << 0;
1954 /// Indicates whether the ADT is a union.
1955 const IS_UNION
= 1 << 1;
1956 /// Indicates whether the ADT is a struct.
1957 const IS_STRUCT
= 1 << 2;
1958 /// Indicates whether the ADT is a struct and has a constructor.
1959 const HAS_CTOR
= 1 << 3;
1960 /// Indicates whether the type is `PhantomData`.
1961 const IS_PHANTOM_DATA
= 1 << 4;
1962 /// Indicates whether the type has a `#[fundamental]` attribute.
1963 const IS_FUNDAMENTAL
= 1 << 5;
1964 /// Indicates whether the type is `Box`.
1965 const IS_BOX
= 1 << 6;
1966 /// Indicates whether the type is `ManuallyDrop`.
1967 const IS_MANUALLY_DROP
= 1 << 7;
1968 /// Indicates whether the variant list of this ADT is `#[non_exhaustive]`.
1969 /// (i.e., this flag is never set unless this ADT is an enum).
1970 const IS_VARIANT_LIST_NON_EXHAUSTIVE
= 1 << 8;
1975 #[derive(HashStable)]
1976 pub struct VariantFlags
: u32 {
1977 const NO_VARIANT_FLAGS
= 0;
1978 /// Indicates whether the field list of this variant is `#[non_exhaustive]`.
1979 const IS_FIELD_LIST_NON_EXHAUSTIVE
= 1 << 0;
1980 /// Indicates whether this variant was obtained as part of recovering from
1981 /// a syntactic error. May be incomplete or bogus.
1982 const IS_RECOVERED
= 1 << 1;
1986 /// Definition of a variant -- a struct's fields or a enum variant.
1987 #[derive(Debug, HashStable)]
1988 pub struct VariantDef
{
1989 /// `DefId` that identifies the variant itself.
1990 /// If this variant belongs to a struct or union, then this is a copy of its `DefId`.
1992 /// `DefId` that identifies the variant's constructor.
1993 /// If this variant is a struct variant, then this is `None`.
1994 pub ctor_def_id
: Option
<DefId
>,
1995 /// Variant or struct name.
1996 #[stable_hasher(project(name))]
1998 /// Discriminant of this variant.
1999 pub discr
: VariantDiscr
,
2000 /// Fields of this variant.
2001 pub fields
: Vec
<FieldDef
>,
2002 /// Type of constructor of variant.
2003 pub ctor_kind
: CtorKind
,
2004 /// Flags of the variant (e.g. is field list non-exhaustive)?
2005 flags
: VariantFlags
,
2009 /// Creates a new `VariantDef`.
2011 /// `variant_did` is the `DefId` that identifies the enum variant (if this `VariantDef`
2012 /// represents an enum variant).
2014 /// `ctor_did` is the `DefId` that identifies the constructor of unit or
2015 /// tuple-variants/structs. If this is a `struct`-variant then this should be `None`.
2017 /// `parent_did` is the `DefId` of the `AdtDef` representing the enum or struct that
2018 /// owns this variant. It is used for checking if a struct has `#[non_exhaustive]` w/out having
2019 /// to go through the redirect of checking the ctor's attributes - but compiling a small crate
2020 /// requires loading the `AdtDef`s for all the structs in the universe (e.g., coherence for any
2021 /// built-in trait), and we do not want to load attributes twice.
2023 /// If someone speeds up attribute loading to not be a performance concern, they can
2024 /// remove this hack and use the constructor `DefId` everywhere.
2027 variant_did
: Option
<DefId
>,
2028 ctor_def_id
: Option
<DefId
>,
2029 discr
: VariantDiscr
,
2030 fields
: Vec
<FieldDef
>,
2031 ctor_kind
: CtorKind
,
2035 is_field_list_non_exhaustive
: bool
,
2038 "VariantDef::new(ident = {:?}, variant_did = {:?}, ctor_def_id = {:?}, discr = {:?},
2039 fields = {:?}, ctor_kind = {:?}, adt_kind = {:?}, parent_did = {:?})",
2040 ident
, variant_did
, ctor_def_id
, discr
, fields
, ctor_kind
, adt_kind
, parent_did
,
2043 let mut flags
= VariantFlags
::NO_VARIANT_FLAGS
;
2044 if is_field_list_non_exhaustive
{
2045 flags
|= VariantFlags
::IS_FIELD_LIST_NON_EXHAUSTIVE
;
2049 flags
|= VariantFlags
::IS_RECOVERED
;
2053 def_id
: variant_did
.unwrap_or(parent_did
),
2063 /// Is this field list non-exhaustive?
2065 pub fn is_field_list_non_exhaustive(&self) -> bool
{
2066 self.flags
.intersects(VariantFlags
::IS_FIELD_LIST_NON_EXHAUSTIVE
)
2069 /// Was this variant obtained as part of recovering from a syntactic error?
2071 pub fn is_recovered(&self) -> bool
{
2072 self.flags
.intersects(VariantFlags
::IS_RECOVERED
)
2076 #[derive(Copy, Clone, Debug, PartialEq, Eq, TyEncodable, TyDecodable, HashStable)]
2077 pub enum VariantDiscr
{
2078 /// Explicit value for this variant, i.e., `X = 123`.
2079 /// The `DefId` corresponds to the embedded constant.
2082 /// The previous variant's discriminant plus one.
2083 /// For efficiency reasons, the distance from the
2084 /// last `Explicit` discriminant is being stored,
2085 /// or `0` for the first variant, if it has none.
2089 #[derive(Debug, HashStable)]
2090 pub struct FieldDef
{
2092 #[stable_hasher(project(name))]
2094 pub vis
: Visibility
,
2097 /// The definition of a user-defined type, e.g., a `struct`, `enum`, or `union`.
2099 /// These are all interned (by `alloc_adt_def`) into the global arena.
2101 /// The initialism *ADT* stands for an [*algebraic data type (ADT)*][adt].
2102 /// This is slightly wrong because `union`s are not ADTs.
2103 /// Moreover, Rust only allows recursive data types through indirection.
2105 /// [adt]: https://en.wikipedia.org/wiki/Algebraic_data_type
2107 /// The `DefId` of the struct, enum or union item.
2109 /// Variants of the ADT. If this is a struct or union, then there will be a single variant.
2110 pub variants
: IndexVec
<VariantIdx
, VariantDef
>,
2111 /// Flags of the ADT (e.g., is this a struct? is this non-exhaustive?).
2113 /// Repr options provided by the user.
2114 pub repr
: ReprOptions
,
2117 impl PartialOrd
for AdtDef
{
2118 fn partial_cmp(&self, other
: &AdtDef
) -> Option
<Ordering
> {
2119 Some(self.cmp(&other
))
2123 /// There should be only one AdtDef for each `did`, therefore
2124 /// it is fine to implement `Ord` only based on `did`.
2125 impl Ord
for AdtDef
{
2126 fn cmp(&self, other
: &AdtDef
) -> Ordering
{
2127 self.did
.cmp(&other
.did
)
2131 impl PartialEq
for AdtDef
{
2132 // `AdtDef`s are always interned, and this is part of `TyS` equality.
2134 fn eq(&self, other
: &Self) -> bool
{
2135 ptr
::eq(self, other
)
2139 impl Eq
for AdtDef {}
2141 impl Hash
for AdtDef
{
2143 fn hash
<H
: Hasher
>(&self, s
: &mut H
) {
2144 (self as *const AdtDef
).hash(s
)
2148 impl<S
: Encoder
> Encodable
<S
> for AdtDef
{
2149 fn encode(&self, s
: &mut S
) -> Result
<(), S
::Error
> {
2154 impl<'a
> HashStable
<StableHashingContext
<'a
>> for AdtDef
{
2155 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
2157 static CACHE
: RefCell
<FxHashMap
<usize, Fingerprint
>> = Default
::default();
2160 let hash
: Fingerprint
= CACHE
.with(|cache
| {
2161 let addr
= self as *const AdtDef
as usize;
2162 *cache
.borrow_mut().entry(addr
).or_insert_with(|| {
2163 let ty
::AdtDef { did, ref variants, ref flags, ref repr }
= *self;
2165 let mut hasher
= StableHasher
::new();
2166 did
.hash_stable(hcx
, &mut hasher
);
2167 variants
.hash_stable(hcx
, &mut hasher
);
2168 flags
.hash_stable(hcx
, &mut hasher
);
2169 repr
.hash_stable(hcx
, &mut hasher
);
2175 hash
.hash_stable(hcx
, hasher
);
2179 #[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
2186 impl Into
<DataTypeKind
> for AdtKind
{
2187 fn into(self) -> DataTypeKind
{
2189 AdtKind
::Struct
=> DataTypeKind
::Struct
,
2190 AdtKind
::Union
=> DataTypeKind
::Union
,
2191 AdtKind
::Enum
=> DataTypeKind
::Enum
,
2197 #[derive(TyEncodable, TyDecodable, Default, HashStable)]
2198 pub struct ReprFlags
: u8 {
2199 const IS_C
= 1 << 0;
2200 const IS_SIMD
= 1 << 1;
2201 const IS_TRANSPARENT
= 1 << 2;
2202 // Internal only for now. If true, don't reorder fields.
2203 const IS_LINEAR
= 1 << 3;
2204 // If true, don't expose any niche to type's context.
2205 const HIDE_NICHE
= 1 << 4;
2206 // Any of these flags being set prevent field reordering optimisation.
2207 const IS_UNOPTIMISABLE
= ReprFlags
::IS_C
.bits
|
2208 ReprFlags
::IS_SIMD
.bits
|
2209 ReprFlags
::IS_LINEAR
.bits
;
2213 /// Represents the repr options provided by the user,
2214 #[derive(Copy, Clone, Debug, Eq, PartialEq, TyEncodable, TyDecodable, Default, HashStable)]
2215 pub struct ReprOptions
{
2216 pub int
: Option
<attr
::IntType
>,
2217 pub align
: Option
<Align
>,
2218 pub pack
: Option
<Align
>,
2219 pub flags
: ReprFlags
,
2223 pub fn new(tcx
: TyCtxt
<'_
>, did
: DefId
) -> ReprOptions
{
2224 let mut flags
= ReprFlags
::empty();
2225 let mut size
= None
;
2226 let mut max_align
: Option
<Align
> = None
;
2227 let mut min_pack
: Option
<Align
> = None
;
2228 for attr
in tcx
.get_attrs(did
).iter() {
2229 for r
in attr
::find_repr_attrs(&tcx
.sess
, attr
) {
2230 flags
.insert(match r
{
2231 attr
::ReprC
=> ReprFlags
::IS_C
,
2232 attr
::ReprPacked(pack
) => {
2233 let pack
= Align
::from_bytes(pack
as u64).unwrap();
2234 min_pack
= Some(if let Some(min_pack
) = min_pack
{
2241 attr
::ReprTransparent
=> ReprFlags
::IS_TRANSPARENT
,
2242 attr
::ReprNoNiche
=> ReprFlags
::HIDE_NICHE
,
2243 attr
::ReprSimd
=> ReprFlags
::IS_SIMD
,
2244 attr
::ReprInt(i
) => {
2248 attr
::ReprAlign(align
) => {
2249 max_align
= max_align
.max(Some(Align
::from_bytes(align
as u64).unwrap()));
2256 // This is here instead of layout because the choice must make it into metadata.
2257 if !tcx
.consider_optimizing(|| format
!("Reorder fields of {:?}", tcx
.def_path_str(did
))) {
2258 flags
.insert(ReprFlags
::IS_LINEAR
);
2260 ReprOptions { int: size, align: max_align, pack: min_pack, flags }
2264 pub fn simd(&self) -> bool
{
2265 self.flags
.contains(ReprFlags
::IS_SIMD
)
2268 pub fn c(&self) -> bool
{
2269 self.flags
.contains(ReprFlags
::IS_C
)
2272 pub fn packed(&self) -> bool
{
2276 pub fn transparent(&self) -> bool
{
2277 self.flags
.contains(ReprFlags
::IS_TRANSPARENT
)
2280 pub fn linear(&self) -> bool
{
2281 self.flags
.contains(ReprFlags
::IS_LINEAR
)
2284 pub fn hide_niche(&self) -> bool
{
2285 self.flags
.contains(ReprFlags
::HIDE_NICHE
)
2288 /// Returns the discriminant type, given these `repr` options.
2289 /// This must only be called on enums!
2290 pub fn discr_type(&self) -> attr
::IntType
{
2291 self.int
.unwrap_or(attr
::SignedInt(ast
::IntTy
::Isize
))
2294 /// Returns `true` if this `#[repr()]` should inhabit "smart enum
2295 /// layout" optimizations, such as representing `Foo<&T>` as a
2297 pub fn inhibit_enum_layout_opt(&self) -> bool
{
2298 self.c() || self.int
.is_some()
2301 /// Returns `true` if this `#[repr()]` should inhibit struct field reordering
2302 /// optimizations, such as with `repr(C)`, `repr(packed(1))`, or `repr(<int>)`.
2303 pub fn inhibit_struct_field_reordering_opt(&self) -> bool
{
2304 if let Some(pack
) = self.pack
{
2305 if pack
.bytes() == 1 {
2309 self.flags
.intersects(ReprFlags
::IS_UNOPTIMISABLE
) || self.int
.is_some()
2312 /// Returns `true` if this `#[repr()]` should inhibit union ABI optimisations.
2313 pub fn inhibit_union_abi_opt(&self) -> bool
{
2319 /// Creates a new `AdtDef`.
2324 variants
: IndexVec
<VariantIdx
, VariantDef
>,
2327 debug
!("AdtDef::new({:?}, {:?}, {:?}, {:?})", did
, kind
, variants
, repr
);
2328 let mut flags
= AdtFlags
::NO_ADT_FLAGS
;
2330 if kind
== AdtKind
::Enum
&& tcx
.has_attr(did
, sym
::non_exhaustive
) {
2331 debug
!("found non-exhaustive variant list for {:?}", did
);
2332 flags
= flags
| AdtFlags
::IS_VARIANT_LIST_NON_EXHAUSTIVE
;
2335 flags
|= match kind
{
2336 AdtKind
::Enum
=> AdtFlags
::IS_ENUM
,
2337 AdtKind
::Union
=> AdtFlags
::IS_UNION
,
2338 AdtKind
::Struct
=> AdtFlags
::IS_STRUCT
,
2341 if kind
== AdtKind
::Struct
&& variants
[VariantIdx
::new(0)].ctor_def_id
.is_some() {
2342 flags
|= AdtFlags
::HAS_CTOR
;
2345 let attrs
= tcx
.get_attrs(did
);
2346 if tcx
.sess
.contains_name(&attrs
, sym
::fundamental
) {
2347 flags
|= AdtFlags
::IS_FUNDAMENTAL
;
2349 if Some(did
) == tcx
.lang_items().phantom_data() {
2350 flags
|= AdtFlags
::IS_PHANTOM_DATA
;
2352 if Some(did
) == tcx
.lang_items().owned_box() {
2353 flags
|= AdtFlags
::IS_BOX
;
2355 if Some(did
) == tcx
.lang_items().manually_drop() {
2356 flags
|= AdtFlags
::IS_MANUALLY_DROP
;
2359 AdtDef { did, variants, flags, repr }
2362 /// Returns `true` if this is a struct.
2364 pub fn is_struct(&self) -> bool
{
2365 self.flags
.contains(AdtFlags
::IS_STRUCT
)
2368 /// Returns `true` if this is a union.
2370 pub fn is_union(&self) -> bool
{
2371 self.flags
.contains(AdtFlags
::IS_UNION
)
2374 /// Returns `true` if this is a enum.
2376 pub fn is_enum(&self) -> bool
{
2377 self.flags
.contains(AdtFlags
::IS_ENUM
)
2380 /// Returns `true` if the variant list of this ADT is `#[non_exhaustive]`.
2382 pub fn is_variant_list_non_exhaustive(&self) -> bool
{
2383 self.flags
.contains(AdtFlags
::IS_VARIANT_LIST_NON_EXHAUSTIVE
)
2386 /// Returns the kind of the ADT.
2388 pub fn adt_kind(&self) -> AdtKind
{
2391 } else if self.is_union() {
2398 /// Returns a description of this abstract data type.
2399 pub fn descr(&self) -> &'
static str {
2400 match self.adt_kind() {
2401 AdtKind
::Struct
=> "struct",
2402 AdtKind
::Union
=> "union",
2403 AdtKind
::Enum
=> "enum",
2407 /// Returns a description of a variant of this abstract data type.
2409 pub fn variant_descr(&self) -> &'
static str {
2410 match self.adt_kind() {
2411 AdtKind
::Struct
=> "struct",
2412 AdtKind
::Union
=> "union",
2413 AdtKind
::Enum
=> "variant",
2417 /// If this function returns `true`, it implies that `is_struct` must return `true`.
2419 pub fn has_ctor(&self) -> bool
{
2420 self.flags
.contains(AdtFlags
::HAS_CTOR
)
2423 /// Returns `true` if this type is `#[fundamental]` for the purposes
2424 /// of coherence checking.
2426 pub fn is_fundamental(&self) -> bool
{
2427 self.flags
.contains(AdtFlags
::IS_FUNDAMENTAL
)
2430 /// Returns `true` if this is `PhantomData<T>`.
2432 pub fn is_phantom_data(&self) -> bool
{
2433 self.flags
.contains(AdtFlags
::IS_PHANTOM_DATA
)
2436 /// Returns `true` if this is Box<T>.
2438 pub fn is_box(&self) -> bool
{
2439 self.flags
.contains(AdtFlags
::IS_BOX
)
2442 /// Returns `true` if this is `ManuallyDrop<T>`.
2444 pub fn is_manually_drop(&self) -> bool
{
2445 self.flags
.contains(AdtFlags
::IS_MANUALLY_DROP
)
2448 /// Returns `true` if this type has a destructor.
2449 pub fn has_dtor(&self, tcx
: TyCtxt
<'tcx
>) -> bool
{
2450 self.destructor(tcx
).is_some()
2453 /// Asserts this is a struct or union and returns its unique variant.
2454 pub fn non_enum_variant(&self) -> &VariantDef
{
2455 assert
!(self.is_struct() || self.is_union());
2456 &self.variants
[VariantIdx
::new(0)]
2460 pub fn predicates(&self, tcx
: TyCtxt
<'tcx
>) -> GenericPredicates
<'tcx
> {
2461 tcx
.predicates_of(self.did
)
2464 /// Returns an iterator over all fields contained
2467 pub fn all_fields(&self) -> impl Iterator
<Item
= &FieldDef
> + Clone
{
2468 self.variants
.iter().flat_map(|v
| v
.fields
.iter())
2471 pub fn is_payloadfree(&self) -> bool
{
2472 !self.variants
.is_empty() && self.variants
.iter().all(|v
| v
.fields
.is_empty())
2475 /// Return a `VariantDef` given a variant id.
2476 pub fn variant_with_id(&self, vid
: DefId
) -> &VariantDef
{
2477 self.variants
.iter().find(|v
| v
.def_id
== vid
).expect("variant_with_id: unknown variant")
2480 /// Return a `VariantDef` given a constructor id.
2481 pub fn variant_with_ctor_id(&self, cid
: DefId
) -> &VariantDef
{
2484 .find(|v
| v
.ctor_def_id
== Some(cid
))
2485 .expect("variant_with_ctor_id: unknown variant")
2488 /// Return the index of `VariantDef` given a variant id.
2489 pub fn variant_index_with_id(&self, vid
: DefId
) -> VariantIdx
{
2492 .find(|(_
, v
)| v
.def_id
== vid
)
2493 .expect("variant_index_with_id: unknown variant")
2497 /// Return the index of `VariantDef` given a constructor id.
2498 pub fn variant_index_with_ctor_id(&self, cid
: DefId
) -> VariantIdx
{
2501 .find(|(_
, v
)| v
.ctor_def_id
== Some(cid
))
2502 .expect("variant_index_with_ctor_id: unknown variant")
2506 pub fn variant_of_res(&self, res
: Res
) -> &VariantDef
{
2508 Res
::Def(DefKind
::Variant
, vid
) => self.variant_with_id(vid
),
2509 Res
::Def(DefKind
::Ctor(..), cid
) => self.variant_with_ctor_id(cid
),
2510 Res
::Def(DefKind
::Struct
, _
)
2511 | Res
::Def(DefKind
::Union
, _
)
2512 | Res
::Def(DefKind
::TyAlias
, _
)
2513 | Res
::Def(DefKind
::AssocTy
, _
)
2515 | Res
::SelfCtor(..) => self.non_enum_variant(),
2516 _
=> bug
!("unexpected res {:?} in variant_of_res", res
),
2521 pub fn eval_explicit_discr(&self, tcx
: TyCtxt
<'tcx
>, expr_did
: DefId
) -> Option
<Discr
<'tcx
>> {
2522 assert
!(self.is_enum());
2523 let param_env
= tcx
.param_env(expr_did
);
2524 let repr_type
= self.repr
.discr_type();
2525 match tcx
.const_eval_poly(expr_did
) {
2527 let ty
= repr_type
.to_ty(tcx
);
2528 if let Some(b
) = val
.try_to_bits_for_ty(tcx
, param_env
, ty
) {
2529 trace
!("discriminants: {} ({:?})", b
, repr_type
);
2530 Some(Discr { val: b, ty }
)
2532 info
!("invalid enum discriminant: {:#?}", val
);
2533 crate::mir
::interpret
::struct_error(
2534 tcx
.at(tcx
.def_span(expr_did
)),
2535 "constant evaluation of enum discriminant resulted in non-integer",
2542 let msg
= match err
{
2543 ErrorHandled
::Reported(ErrorReported
) | ErrorHandled
::Linted
=> {
2544 "enum discriminant evaluation failed"
2546 ErrorHandled
::TooGeneric
=> "enum discriminant depends on generics",
2548 tcx
.sess
.delay_span_bug(tcx
.def_span(expr_did
), msg
);
2555 pub fn discriminants(
2558 ) -> impl Iterator
<Item
= (VariantIdx
, Discr
<'tcx
>)> + Captures
<'tcx
> {
2559 assert
!(self.is_enum());
2560 let repr_type
= self.repr
.discr_type();
2561 let initial
= repr_type
.initial_discriminant(tcx
);
2562 let mut prev_discr
= None
::<Discr
<'tcx
>>;
2563 self.variants
.iter_enumerated().map(move |(i
, v
)| {
2564 let mut discr
= prev_discr
.map_or(initial
, |d
| d
.wrap_incr(tcx
));
2565 if let VariantDiscr
::Explicit(expr_did
) = v
.discr
{
2566 if let Some(new_discr
) = self.eval_explicit_discr(tcx
, expr_did
) {
2570 prev_discr
= Some(discr
);
2577 pub fn variant_range(&self) -> Range
<VariantIdx
> {
2578 VariantIdx
::new(0)..VariantIdx
::new(self.variants
.len())
2581 /// Computes the discriminant value used by a specific variant.
2582 /// Unlike `discriminants`, this is (amortized) constant-time,
2583 /// only doing at most one query for evaluating an explicit
2584 /// discriminant (the last one before the requested variant),
2585 /// assuming there are no constant-evaluation errors there.
2587 pub fn discriminant_for_variant(
2590 variant_index
: VariantIdx
,
2592 assert
!(self.is_enum());
2593 let (val
, offset
) = self.discriminant_def_for_variant(variant_index
);
2594 let explicit_value
= val
2595 .and_then(|expr_did
| self.eval_explicit_discr(tcx
, expr_did
))
2596 .unwrap_or_else(|| self.repr
.discr_type().initial_discriminant(tcx
));
2597 explicit_value
.checked_add(tcx
, offset
as u128
).0
2600 /// Yields a `DefId` for the discriminant and an offset to add to it
2601 /// Alternatively, if there is no explicit discriminant, returns the
2602 /// inferred discriminant directly.
2603 pub fn discriminant_def_for_variant(&self, variant_index
: VariantIdx
) -> (Option
<DefId
>, u32) {
2604 assert
!(!self.variants
.is_empty());
2605 let mut explicit_index
= variant_index
.as_u32();
2608 match self.variants
[VariantIdx
::from_u32(explicit_index
)].discr
{
2609 ty
::VariantDiscr
::Relative(0) => {
2613 ty
::VariantDiscr
::Relative(distance
) => {
2614 explicit_index
-= distance
;
2616 ty
::VariantDiscr
::Explicit(did
) => {
2617 expr_did
= Some(did
);
2622 (expr_did
, variant_index
.as_u32() - explicit_index
)
2625 pub fn destructor(&self, tcx
: TyCtxt
<'tcx
>) -> Option
<Destructor
> {
2626 tcx
.adt_destructor(self.did
)
2629 /// Returns a list of types such that `Self: Sized` if and only
2630 /// if that type is `Sized`, or `TyErr` if this type is recursive.
2632 /// Oddly enough, checking that the sized-constraint is `Sized` is
2633 /// actually more expressive than checking all members:
2634 /// the `Sized` trait is inductive, so an associated type that references
2635 /// `Self` would prevent its containing ADT from being `Sized`.
2637 /// Due to normalization being eager, this applies even if
2638 /// the associated type is behind a pointer (e.g., issue #31299).
2639 pub fn sized_constraint(&self, tcx
: TyCtxt
<'tcx
>) -> &'tcx
[Ty
<'tcx
>] {
2640 tcx
.adt_sized_constraint(self.did
).0
2644 impl<'tcx
> FieldDef
{
2645 /// Returns the type of this field. The `subst` is typically obtained
2646 /// via the second field of `TyKind::AdtDef`.
2647 pub fn ty(&self, tcx
: TyCtxt
<'tcx
>, subst
: SubstsRef
<'tcx
>) -> Ty
<'tcx
> {
2648 tcx
.type_of(self.did
).subst(tcx
, subst
)
2652 /// Represents the various closure traits in the language. This
2653 /// will determine the type of the environment (`self`, in the
2654 /// desugaring) argument that the closure expects.
2656 /// You can get the environment type of a closure using
2657 /// `tcx.closure_env_ty()`.
2658 #[derive(Clone, Copy, PartialOrd, Ord, PartialEq, Eq, Hash, Debug, TyEncodable, TyDecodable)]
2659 #[derive(HashStable)]
2660 pub enum ClosureKind
{
2661 // Warning: Ordering is significant here! The ordering is chosen
2662 // because the trait Fn is a subtrait of FnMut and so in turn, and
2663 // hence we order it so that Fn < FnMut < FnOnce.
2669 impl<'tcx
> ClosureKind
{
2670 // This is the initial value used when doing upvar inference.
2671 pub const LATTICE_BOTTOM
: ClosureKind
= ClosureKind
::Fn
;
2673 pub fn trait_did(&self, tcx
: TyCtxt
<'tcx
>) -> DefId
{
2675 ClosureKind
::Fn
=> tcx
.require_lang_item(LangItem
::Fn
, None
),
2676 ClosureKind
::FnMut
=> tcx
.require_lang_item(LangItem
::FnMut
, None
),
2677 ClosureKind
::FnOnce
=> tcx
.require_lang_item(LangItem
::FnOnce
, None
),
2681 /// Returns `true` if a type that impls this closure kind
2682 /// must also implement `other`.
2683 pub fn extends(self, other
: ty
::ClosureKind
) -> bool
{
2684 match (self, other
) {
2685 (ClosureKind
::Fn
, ClosureKind
::Fn
) => true,
2686 (ClosureKind
::Fn
, ClosureKind
::FnMut
) => true,
2687 (ClosureKind
::Fn
, ClosureKind
::FnOnce
) => true,
2688 (ClosureKind
::FnMut
, ClosureKind
::FnMut
) => true,
2689 (ClosureKind
::FnMut
, ClosureKind
::FnOnce
) => true,
2690 (ClosureKind
::FnOnce
, ClosureKind
::FnOnce
) => true,
2695 /// Returns the representative scalar type for this closure kind.
2696 /// See `TyS::to_opt_closure_kind` for more details.
2697 pub fn to_ty(self, tcx
: TyCtxt
<'tcx
>) -> Ty
<'tcx
> {
2699 ty
::ClosureKind
::Fn
=> tcx
.types
.i8,
2700 ty
::ClosureKind
::FnMut
=> tcx
.types
.i16,
2701 ty
::ClosureKind
::FnOnce
=> tcx
.types
.i32,
2707 pub fn from_mutbl(m
: hir
::Mutability
) -> BorrowKind
{
2709 hir
::Mutability
::Mut
=> MutBorrow
,
2710 hir
::Mutability
::Not
=> ImmBorrow
,
2714 /// Returns a mutability `m` such that an `&m T` pointer could be used to obtain this borrow
2715 /// kind. Because borrow kinds are richer than mutabilities, we sometimes have to pick a
2716 /// mutability that is stronger than necessary so that it at least *would permit* the borrow in
2718 pub fn to_mutbl_lossy(self) -> hir
::Mutability
{
2720 MutBorrow
=> hir
::Mutability
::Mut
,
2721 ImmBorrow
=> hir
::Mutability
::Not
,
2723 // We have no type corresponding to a unique imm borrow, so
2724 // use `&mut`. It gives all the capabilities of an `&uniq`
2725 // and hence is a safe "over approximation".
2726 UniqueImmBorrow
=> hir
::Mutability
::Mut
,
2730 pub fn to_user_str(&self) -> &'
static str {
2732 MutBorrow
=> "mutable",
2733 ImmBorrow
=> "immutable",
2734 UniqueImmBorrow
=> "uniquely immutable",
2739 pub type Attributes
<'tcx
> = &'tcx
[ast
::Attribute
];
2741 #[derive(Debug, PartialEq, Eq)]
2742 pub enum ImplOverlapKind
{
2743 /// These impls are always allowed to overlap.
2745 /// Whether or not the impl is permitted due to the trait being a `#[marker]` trait
2748 /// These impls are allowed to overlap, but that raises
2749 /// an issue #33140 future-compatibility warning.
2751 /// Some background: in Rust 1.0, the trait-object types `Send + Sync` (today's
2752 /// `dyn Send + Sync`) and `Sync + Send` (now `dyn Sync + Send`) were different.
2754 /// The widely-used version 0.1.0 of the crate `traitobject` had accidentally relied
2755 /// that difference, making what reduces to the following set of impls:
2759 /// impl Trait for dyn Send + Sync {}
2760 /// impl Trait for dyn Sync + Send {}
2763 /// Obviously, once we made these types be identical, that code causes a coherence
2764 /// error and a fairly big headache for us. However, luckily for us, the trait
2765 /// `Trait` used in this case is basically a marker trait, and therefore having
2766 /// overlapping impls for it is sound.
2768 /// To handle this, we basically regard the trait as a marker trait, with an additional
2769 /// future-compatibility warning. To avoid accidentally "stabilizing" this feature,
2770 /// it has the following restrictions:
2772 /// 1. The trait must indeed be a marker-like trait (i.e., no items), and must be
2774 /// 2. The trait-ref of both impls must be equal.
2775 /// 3. The trait-ref of both impls must be a trait object type consisting only of
2777 /// 4. Neither of the impls can have any where-clauses.
2779 /// Once `traitobject` 0.1.0 is no longer an active concern, this hack can be removed.
2783 impl<'tcx
> TyCtxt
<'tcx
> {
2784 pub fn typeck_body(self, body
: hir
::BodyId
) -> &'tcx TypeckResults
<'tcx
> {
2785 self.typeck(self.hir().body_owner_def_id(body
))
2788 /// Returns an iterator of the `DefId`s for all body-owners in this
2789 /// crate. If you would prefer to iterate over the bodies
2790 /// themselves, you can do `self.hir().krate().body_ids.iter()`.
2791 pub fn body_owners(self) -> impl Iterator
<Item
= LocalDefId
> + Captures
<'tcx
> + 'tcx
{
2796 .map(move |&body_id
| self.hir().body_owner_def_id(body_id
))
2799 pub fn par_body_owners
<F
: Fn(LocalDefId
) + sync
::Sync
+ sync
::Send
>(self, f
: F
) {
2800 par_iter(&self.hir().krate().body_ids
)
2801 .for_each(|&body_id
| f(self.hir().body_owner_def_id(body_id
)));
2804 pub fn provided_trait_methods(self, id
: DefId
) -> impl 'tcx
+ Iterator
<Item
= &'tcx AssocItem
> {
2805 self.associated_items(id
)
2806 .in_definition_order()
2807 .filter(|item
| item
.kind
== AssocKind
::Fn
&& item
.defaultness
.has_value())
2810 pub fn opt_item_name(self, def_id
: DefId
) -> Option
<Ident
> {
2813 .and_then(|def_id
| self.hir().get(self.hir().local_def_id_to_hir_id(def_id
)).ident())
2816 pub fn opt_associated_item(self, def_id
: DefId
) -> Option
<&'tcx AssocItem
> {
2817 let is_associated_item
= if let Some(def_id
) = def_id
.as_local() {
2818 match self.hir().get(self.hir().local_def_id_to_hir_id(def_id
)) {
2819 Node
::TraitItem(_
) | Node
::ImplItem(_
) => true,
2823 match self.def_kind(def_id
) {
2824 DefKind
::AssocConst
| DefKind
::AssocFn
| DefKind
::AssocTy
=> true,
2829 is_associated_item
.then(|| self.associated_item(def_id
))
2832 pub fn field_index(self, hir_id
: hir
::HirId
, typeck_results
: &TypeckResults
<'_
>) -> usize {
2833 typeck_results
.field_indices().get(hir_id
).cloned().expect("no index for a field")
2836 pub fn find_field_index(self, ident
: Ident
, variant
: &VariantDef
) -> Option
<usize> {
2837 variant
.fields
.iter().position(|field
| self.hygienic_eq(ident
, field
.ident
, variant
.def_id
))
2840 /// Returns `true` if the impls are the same polarity and the trait either
2841 /// has no items or is annotated `#[marker]` and prevents item overrides.
2842 pub fn impls_are_allowed_to_overlap(
2846 ) -> Option
<ImplOverlapKind
> {
2847 // If either trait impl references an error, they're allowed to overlap,
2848 // as one of them essentially doesn't exist.
2849 if self.impl_trait_ref(def_id1
).map_or(false, |tr
| tr
.references_error())
2850 || self.impl_trait_ref(def_id2
).map_or(false, |tr
| tr
.references_error())
2852 return Some(ImplOverlapKind
::Permitted { marker: false }
);
2855 match (self.impl_polarity(def_id1
), self.impl_polarity(def_id2
)) {
2856 (ImplPolarity
::Reservation
, _
) | (_
, ImplPolarity
::Reservation
) => {
2857 // `#[rustc_reservation_impl]` impls don't overlap with anything
2859 "impls_are_allowed_to_overlap({:?}, {:?}) = Some(Permitted) (reservations)",
2862 return Some(ImplOverlapKind
::Permitted { marker: false }
);
2864 (ImplPolarity
::Positive
, ImplPolarity
::Negative
)
2865 | (ImplPolarity
::Negative
, ImplPolarity
::Positive
) => {
2866 // `impl AutoTrait for Type` + `impl !AutoTrait for Type`
2868 "impls_are_allowed_to_overlap({:?}, {:?}) - None (differing polarities)",
2873 (ImplPolarity
::Positive
, ImplPolarity
::Positive
)
2874 | (ImplPolarity
::Negative
, ImplPolarity
::Negative
) => {}
2877 let is_marker_overlap
= {
2878 let is_marker_impl
= |def_id
: DefId
| -> bool
{
2879 let trait_ref
= self.impl_trait_ref(def_id
);
2880 trait_ref
.map_or(false, |tr
| self.trait_def(tr
.def_id
).is_marker
)
2882 is_marker_impl(def_id1
) && is_marker_impl(def_id2
)
2885 if is_marker_overlap
{
2887 "impls_are_allowed_to_overlap({:?}, {:?}) = Some(Permitted) (marker overlap)",
2890 Some(ImplOverlapKind
::Permitted { marker: true }
)
2892 if let Some(self_ty1
) = self.issue33140_self_ty(def_id1
) {
2893 if let Some(self_ty2
) = self.issue33140_self_ty(def_id2
) {
2894 if self_ty1
== self_ty2
{
2896 "impls_are_allowed_to_overlap({:?}, {:?}) - issue #33140 HACK",
2899 return Some(ImplOverlapKind
::Issue33140
);
2902 "impls_are_allowed_to_overlap({:?}, {:?}) - found {:?} != {:?}",
2903 def_id1
, def_id2
, self_ty1
, self_ty2
2909 debug
!("impls_are_allowed_to_overlap({:?}, {:?}) = None", def_id1
, def_id2
);
2914 /// Returns `ty::VariantDef` if `res` refers to a struct,
2915 /// or variant or their constructors, panics otherwise.
2916 pub fn expect_variant_res(self, res
: Res
) -> &'tcx VariantDef
{
2918 Res
::Def(DefKind
::Variant
, did
) => {
2919 let enum_did
= self.parent(did
).unwrap();
2920 self.adt_def(enum_did
).variant_with_id(did
)
2922 Res
::Def(DefKind
::Struct
| DefKind
::Union
, did
) => self.adt_def(did
).non_enum_variant(),
2923 Res
::Def(DefKind
::Ctor(CtorOf
::Variant
, ..), variant_ctor_did
) => {
2924 let variant_did
= self.parent(variant_ctor_did
).unwrap();
2925 let enum_did
= self.parent(variant_did
).unwrap();
2926 self.adt_def(enum_did
).variant_with_ctor_id(variant_ctor_did
)
2928 Res
::Def(DefKind
::Ctor(CtorOf
::Struct
, ..), ctor_did
) => {
2929 let struct_did
= self.parent(ctor_did
).expect("struct ctor has no parent");
2930 self.adt_def(struct_did
).non_enum_variant()
2932 _
=> bug
!("expect_variant_res used with unexpected res {:?}", res
),
2936 pub fn item_name(self, id
: DefId
) -> Symbol
{
2937 if id
.index
== CRATE_DEF_INDEX
{
2938 self.original_crate_name(id
.krate
)
2940 let def_key
= self.def_key(id
);
2941 match def_key
.disambiguated_data
.data
{
2942 // The name of a constructor is that of its parent.
2943 rustc_hir
::definitions
::DefPathData
::Ctor
=> {
2944 self.item_name(DefId { krate: id.krate, index: def_key.parent.unwrap() }
)
2946 _
=> def_key
.disambiguated_data
.data
.get_opt_name().unwrap_or_else(|| {
2947 bug
!("item_name: no name for {:?}", self.def_path(id
));
2953 /// Returns the possibly-auto-generated MIR of a `(DefId, Subst)` pair.
2954 pub fn instance_mir(self, instance
: ty
::InstanceDef
<'tcx
>) -> &'tcx Body
<'tcx
> {
2956 ty
::InstanceDef
::Item(def
) => {
2957 if let Some((did
, param_did
)) = def
.as_const_arg() {
2958 self.optimized_mir_of_const_arg((did
, param_did
))
2960 self.optimized_mir(def
.did
)
2963 ty
::InstanceDef
::VtableShim(..)
2964 | ty
::InstanceDef
::ReifyShim(..)
2965 | ty
::InstanceDef
::Intrinsic(..)
2966 | ty
::InstanceDef
::FnPtrShim(..)
2967 | ty
::InstanceDef
::Virtual(..)
2968 | ty
::InstanceDef
::ClosureOnceShim { .. }
2969 | ty
::InstanceDef
::DropGlue(..)
2970 | ty
::InstanceDef
::CloneShim(..) => self.mir_shims(instance
),
2974 /// Gets the attributes of a definition.
2975 pub fn get_attrs(self, did
: DefId
) -> Attributes
<'tcx
> {
2976 if let Some(did
) = did
.as_local() {
2977 self.hir().attrs(self.hir().local_def_id_to_hir_id(did
))
2979 self.item_attrs(did
)
2983 /// Determines whether an item is annotated with an attribute.
2984 pub fn has_attr(self, did
: DefId
, attr
: Symbol
) -> bool
{
2985 self.sess
.contains_name(&self.get_attrs(did
), attr
)
2988 /// Returns `true` if this is an `auto trait`.
2989 pub fn trait_is_auto(self, trait_def_id
: DefId
) -> bool
{
2990 self.trait_def(trait_def_id
).has_auto_impl
2993 pub fn generator_layout(self, def_id
: DefId
) -> &'tcx GeneratorLayout
<'tcx
> {
2994 self.optimized_mir(def_id
).generator_layout
.as_ref().unwrap()
2997 /// Given the `DefId` of an impl, returns the `DefId` of the trait it implements.
2998 /// If it implements no trait, returns `None`.
2999 pub fn trait_id_of_impl(self, def_id
: DefId
) -> Option
<DefId
> {
3000 self.impl_trait_ref(def_id
).map(|tr
| tr
.def_id
)
3003 /// If the given defid describes a method belonging to an impl, returns the
3004 /// `DefId` of the impl that the method belongs to; otherwise, returns `None`.
3005 pub fn impl_of_method(self, def_id
: DefId
) -> Option
<DefId
> {
3006 self.opt_associated_item(def_id
).and_then(|trait_item
| match trait_item
.container
{
3007 TraitContainer(_
) => None
,
3008 ImplContainer(def_id
) => Some(def_id
),
3012 /// Looks up the span of `impl_did` if the impl is local; otherwise returns `Err`
3013 /// with the name of the crate containing the impl.
3014 pub fn span_of_impl(self, impl_did
: DefId
) -> Result
<Span
, Symbol
> {
3015 if let Some(impl_did
) = impl_did
.as_local() {
3016 let hir_id
= self.hir().local_def_id_to_hir_id(impl_did
);
3017 Ok(self.hir().span(hir_id
))
3019 Err(self.crate_name(impl_did
.krate
))
3023 /// Hygienically compares a use-site name (`use_name`) for a field or an associated item with
3024 /// its supposed definition name (`def_name`). The method also needs `DefId` of the supposed
3025 /// definition's parent/scope to perform comparison.
3026 pub fn hygienic_eq(self, use_name
: Ident
, def_name
: Ident
, def_parent_def_id
: DefId
) -> bool
{
3027 // We could use `Ident::eq` here, but we deliberately don't. The name
3028 // comparison fails frequently, and we want to avoid the expensive
3029 // `normalize_to_macros_2_0()` calls required for the span comparison whenever possible.
3030 use_name
.name
== def_name
.name
3034 .hygienic_eq(def_name
.span
.ctxt(), self.expansion_that_defined(def_parent_def_id
))
3037 fn expansion_that_defined(self, scope
: DefId
) -> ExpnId
{
3038 match scope
.as_local() {
3039 Some(scope
) => self.hir().definitions().expansion_that_defined(scope
),
3040 None
=> ExpnId
::root(),
3044 pub fn adjust_ident(self, mut ident
: Ident
, scope
: DefId
) -> Ident
{
3045 ident
.span
.normalize_to_macros_2_0_and_adjust(self.expansion_that_defined(scope
));
3049 pub fn adjust_ident_and_get_scope(
3054 ) -> (Ident
, DefId
) {
3056 match ident
.span
.normalize_to_macros_2_0_and_adjust(self.expansion_that_defined(scope
))
3058 Some(actual_expansion
) => {
3059 self.hir().definitions().parent_module_of_macro_def(actual_expansion
)
3061 None
=> self.parent_module(block
).to_def_id(),
3066 pub fn is_object_safe(self, key
: DefId
) -> bool
{
3067 self.object_safety_violations(key
).is_empty()
3071 #[derive(Clone, HashStable)]
3072 pub struct AdtSizedConstraint
<'tcx
>(pub &'tcx
[Ty
<'tcx
>]);
3074 /// Yields the parent function's `DefId` if `def_id` is an `impl Trait` definition.
3075 pub fn is_impl_trait_defn(tcx
: TyCtxt
<'_
>, def_id
: DefId
) -> Option
<DefId
> {
3076 if let Some(def_id
) = def_id
.as_local() {
3077 if let Node
::Item(item
) = tcx
.hir().get(tcx
.hir().local_def_id_to_hir_id(def_id
)) {
3078 if let hir
::ItemKind
::OpaqueTy(ref opaque_ty
) = item
.kind
{
3079 return opaque_ty
.impl_trait_fn
;
3086 pub fn provide(providers
: &mut ty
::query
::Providers
) {
3087 context
::provide(providers
);
3088 erase_regions
::provide(providers
);
3089 layout
::provide(providers
);
3090 util
::provide(providers
);
3091 print
::provide(providers
);
3092 super::util
::bug
::provide(providers
);
3093 *providers
= ty
::query
::Providers
{
3094 trait_impls_of
: trait_def
::trait_impls_of_provider
,
3095 all_local_trait_impls
: trait_def
::all_local_trait_impls
,
3100 /// A map for the local crate mapping each type to a vector of its
3101 /// inherent impls. This is not meant to be used outside of coherence;
3102 /// rather, you should request the vector for a specific type via
3103 /// `tcx.inherent_impls(def_id)` so as to minimize your dependencies
3104 /// (constructing this map requires touching the entire crate).
3105 #[derive(Clone, Debug, Default, HashStable)]
3106 pub struct CrateInherentImpls
{
3107 pub inherent_impls
: DefIdMap
<Vec
<DefId
>>,
3110 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, TyEncodable, HashStable)]
3111 pub struct SymbolName
<'tcx
> {
3112 /// `&str` gives a consistent ordering, which ensures reproducible builds.
3113 pub name
: &'tcx
str,
3116 impl<'tcx
> SymbolName
<'tcx
> {
3117 pub fn new(tcx
: TyCtxt
<'tcx
>, name
: &str) -> SymbolName
<'tcx
> {
3119 name
: unsafe { str::from_utf8_unchecked(tcx.arena.alloc_slice(name.as_bytes())) }
,
3124 impl<'tcx
> fmt
::Display
for SymbolName
<'tcx
> {
3125 fn fmt(&self, fmt
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
3126 fmt
::Display
::fmt(&self.name
, fmt
)
3130 impl<'tcx
> fmt
::Debug
for SymbolName
<'tcx
> {
3131 fn fmt(&self, fmt
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
3132 fmt
::Display
::fmt(&self.name
, fmt
)