1 //! Defines how the compiler represents types internally.
3 //! Two important entities in this module are:
5 //! - [`rustc_middle::ty::Ty`], used to represent the semantics of a type.
6 //! - [`rustc_middle::ty::TyCtxt`], the central data structure in the compiler.
8 //! For more information, see ["The `ty` module: representing types"] in the ructc-dev-guide.
10 //! ["The `ty` module: representing types"]: https://rustc-dev-guide.rust-lang.org/ty.html
12 pub use self::fold
::{TypeFoldable, TypeFolder, TypeVisitor}
;
13 pub use self::AssocItemContainer
::*;
14 pub use self::BorrowKind
::*;
15 pub use self::IntVarValue
::*;
16 pub use self::Variance
::*;
22 use crate::hir
::exports
::ExportMap
;
23 use crate::ich
::StableHashingContext
;
24 use crate::middle
::cstore
::CrateStoreDyn
;
25 use crate::mir
::{Body, GeneratorLayout}
;
26 use crate::traits
::{self, Reveal}
;
28 use crate::ty
::subst
::{GenericArg, InternalSubsts, Subst, SubstsRef}
;
29 use crate::ty
::util
::Discr
;
31 use rustc_attr
as attr
;
32 use rustc_data_structures
::captures
::Captures
;
33 use rustc_data_structures
::fx
::{FxHashMap, FxHashSet}
;
34 use rustc_data_structures
::stable_hasher
::{HashStable, StableHasher}
;
35 use rustc_data_structures
::sync
::{self, par_iter, ParallelIterator}
;
36 use rustc_data_structures
::tagged_ptr
::CopyTaggedPtr
;
38 use rustc_hir
::def
::{CtorKind, CtorOf, DefKind, Res}
;
39 use rustc_hir
::def_id
::{CrateNum, DefId, LocalDefId, LocalDefIdMap, CRATE_DEF_INDEX}
;
40 use rustc_hir
::{Constness, Node}
;
41 use rustc_macros
::HashStable
;
42 use rustc_span
::symbol
::{kw, Ident, Symbol}
;
44 use rustc_target
::abi
::Align
;
46 use std
::cmp
::Ordering
;
47 use std
::hash
::{Hash, Hasher}
;
48 use std
::ops
::ControlFlow
;
49 use std
::{fmt, ptr, str}
;
51 pub use crate::ty
::diagnostics
::*;
52 pub use rustc_type_ir
::InferTy
::*;
53 pub use rustc_type_ir
::*;
55 pub use self::binding
::BindingMode
;
56 pub use self::binding
::BindingMode
::*;
57 pub use self::consts
::{Const, ConstInt, ConstKind, InferConst, ScalarInt, Unevaluated, ValTree}
;
58 pub use self::context
::{
59 tls
, CanonicalUserType
, CanonicalUserTypeAnnotation
, CanonicalUserTypeAnnotations
,
60 CtxtInterners
, DelaySpanBugEmitted
, FreeRegionInfo
, GeneratorInteriorTypeCause
, GlobalCtxt
,
61 Lift
, TyCtxt
, TypeckResults
, UserType
, UserTypeAnnotationIndex
,
63 pub use self::instance
::{Instance, InstanceDef}
;
64 pub use self::list
::List
;
65 pub use self::sty
::BoundRegionKind
::*;
66 pub use self::sty
::RegionKind
::*;
67 pub use self::sty
::TyKind
::*;
69 Binder
, BoundRegion
, BoundRegionKind
, BoundTy
, BoundTyKind
, BoundVar
, BoundVariableKind
,
70 CanonicalPolyFnSig
, ClosureSubsts
, ClosureSubstsParts
, ConstVid
, EarlyBoundRegion
,
71 ExistentialPredicate
, ExistentialProjection
, ExistentialTraitRef
, FnSig
, FreeRegion
, GenSig
,
72 GeneratorSubsts
, GeneratorSubstsParts
, ParamConst
, ParamTy
, PolyExistentialProjection
,
73 PolyExistentialTraitRef
, PolyFnSig
, PolyGenSig
, PolyTraitRef
, ProjectionTy
, Region
, RegionKind
,
74 RegionVid
, TraitRef
, TyKind
, TypeAndMut
, UpvarSubsts
, VarianceDiagInfo
, VarianceDiagMutKind
,
76 pub use self::trait_def
::TraitDef
;
87 pub mod inhabitedness
;
89 pub mod normalize_erasing_regions
;
109 mod structural_impls
;
114 pub struct ResolverOutputs
{
115 pub definitions
: rustc_hir
::definitions
::Definitions
,
116 pub cstore
: Box
<CrateStoreDyn
>,
117 pub visibilities
: FxHashMap
<LocalDefId
, Visibility
>,
118 pub extern_crate_map
: FxHashMap
<LocalDefId
, CrateNum
>,
119 pub maybe_unused_trait_imports
: FxHashSet
<LocalDefId
>,
120 pub maybe_unused_extern_crates
: Vec
<(LocalDefId
, Span
)>,
121 pub export_map
: ExportMap
<LocalDefId
>,
122 pub glob_map
: FxHashMap
<LocalDefId
, FxHashSet
<Symbol
>>,
123 /// Extern prelude entries. The value is `true` if the entry was introduced
124 /// via `extern crate` item and not `--extern` option or compiler built-in.
125 pub extern_prelude
: FxHashMap
<Symbol
, bool
>,
126 pub main_def
: Option
<MainDefinition
>,
129 #[derive(Clone, Copy)]
130 pub struct MainDefinition
{
131 pub res
: Res
<ast
::NodeId
>,
136 impl MainDefinition
{
137 pub fn opt_fn_def_id(self) -> Option
<DefId
> {
138 if let Res
::Def(DefKind
::Fn
, def_id
) = self.res { Some(def_id) }
else { None }
142 /// The "header" of an impl is everything outside the body: a Self type, a trait
143 /// ref (in the case of a trait impl), and a set of predicates (from the
144 /// bounds / where-clauses).
145 #[derive(Clone, Debug, TypeFoldable)]
146 pub struct ImplHeader
<'tcx
> {
147 pub impl_def_id
: DefId
,
148 pub self_ty
: Ty
<'tcx
>,
149 pub trait_ref
: Option
<TraitRef
<'tcx
>>,
150 pub predicates
: Vec
<Predicate
<'tcx
>>,
153 #[derive(Copy, Clone, PartialEq, TyEncodable, TyDecodable, HashStable, Debug)]
154 pub enum ImplPolarity
{
155 /// `impl Trait for Type`
157 /// `impl !Trait for Type`
159 /// `#[rustc_reservation_impl] impl Trait for Type`
161 /// This is a "stability hack", not a real Rust feature.
162 /// See #64631 for details.
166 #[derive(Clone, Debug, PartialEq, Eq, Copy, Hash, TyEncodable, TyDecodable, HashStable)]
167 pub enum Visibility
{
168 /// Visible everywhere (including in other crates).
170 /// Visible only in the given crate-local module.
172 /// Not visible anywhere in the local crate. This is the visibility of private external items.
176 pub trait DefIdTree
: Copy
{
177 fn parent(self, id
: DefId
) -> Option
<DefId
>;
179 fn is_descendant_of(self, mut descendant
: DefId
, ancestor
: DefId
) -> bool
{
180 if descendant
.krate
!= ancestor
.krate
{
184 while descendant
!= ancestor
{
185 match self.parent(descendant
) {
186 Some(parent
) => descendant
= parent
,
187 None
=> return false,
194 impl<'tcx
> DefIdTree
for TyCtxt
<'tcx
> {
195 fn parent(self, id
: DefId
) -> Option
<DefId
> {
196 self.def_key(id
).parent
.map(|index
| DefId { index, ..id }
)
201 pub fn from_hir(visibility
: &hir
::Visibility
<'_
>, id
: hir
::HirId
, tcx
: TyCtxt
<'_
>) -> Self {
202 match visibility
.node
{
203 hir
::VisibilityKind
::Public
=> Visibility
::Public
,
204 hir
::VisibilityKind
::Crate(_
) => Visibility
::Restricted(DefId
::local(CRATE_DEF_INDEX
)),
205 hir
::VisibilityKind
::Restricted { ref path, .. }
=> match path
.res
{
206 // If there is no resolution, `resolve` will have already reported an error, so
207 // assume that the visibility is public to avoid reporting more privacy errors.
208 Res
::Err
=> Visibility
::Public
,
209 def
=> Visibility
::Restricted(def
.def_id()),
211 hir
::VisibilityKind
::Inherited
=> {
212 Visibility
::Restricted(tcx
.parent_module(id
).to_def_id())
217 /// Returns `true` if an item with this visibility is accessible from the given block.
218 pub fn is_accessible_from
<T
: DefIdTree
>(self, module
: DefId
, tree
: T
) -> bool
{
219 let restriction
= match self {
220 // Public items are visible everywhere.
221 Visibility
::Public
=> return true,
222 // Private items from other crates are visible nowhere.
223 Visibility
::Invisible
=> return false,
224 // Restricted items are visible in an arbitrary local module.
225 Visibility
::Restricted(other
) if other
.krate
!= module
.krate
=> return false,
226 Visibility
::Restricted(module
) => module
,
229 tree
.is_descendant_of(module
, restriction
)
232 /// Returns `true` if this visibility is at least as accessible as the given visibility
233 pub fn is_at_least
<T
: DefIdTree
>(self, vis
: Visibility
, tree
: T
) -> bool
{
234 let vis_restriction
= match vis
{
235 Visibility
::Public
=> return self == Visibility
::Public
,
236 Visibility
::Invisible
=> return true,
237 Visibility
::Restricted(module
) => module
,
240 self.is_accessible_from(vis_restriction
, tree
)
243 // Returns `true` if this item is visible anywhere in the local crate.
244 pub fn is_visible_locally(self) -> bool
{
246 Visibility
::Public
=> true,
247 Visibility
::Restricted(def_id
) => def_id
.is_local(),
248 Visibility
::Invisible
=> false,
253 /// The crate variances map is computed during typeck and contains the
254 /// variance of every item in the local crate. You should not use it
255 /// directly, because to do so will make your pass dependent on the
256 /// HIR of every item in the local crate. Instead, use
257 /// `tcx.variances_of()` to get the variance for a *particular*
259 #[derive(HashStable, Debug)]
260 pub struct CrateVariancesMap
<'tcx
> {
261 /// For each item with generics, maps to a vector of the variance
262 /// of its generics. If an item has no generics, it will have no
264 pub variances
: FxHashMap
<DefId
, &'tcx
[ty
::Variance
]>,
267 // Contains information needed to resolve types and (in the future) look up
268 // the types of AST nodes.
269 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
270 pub struct CReaderCacheKey
{
271 pub cnum
: Option
<CrateNum
>,
275 #[allow(rustc::usage_of_ty_tykind)]
276 pub struct TyS
<'tcx
> {
277 /// This field shouldn't be used directly and may be removed in the future.
278 /// Use `TyS::kind()` instead.
280 /// This field shouldn't be used directly and may be removed in the future.
281 /// Use `TyS::flags()` instead.
284 /// This is a kind of confusing thing: it stores the smallest
287 /// (a) the binder itself captures nothing but
288 /// (b) all the late-bound things within the type are captured
289 /// by some sub-binder.
291 /// So, for a type without any late-bound things, like `u32`, this
292 /// will be *innermost*, because that is the innermost binder that
293 /// captures nothing. But for a type `&'D u32`, where `'D` is a
294 /// late-bound region with De Bruijn index `D`, this would be `D + 1`
295 /// -- the binder itself does not capture `D`, but `D` is captured
296 /// by an inner binder.
298 /// We call this concept an "exclusive" binder `D` because all
299 /// De Bruijn indices within the type are contained within `0..D`
301 outer_exclusive_binder
: ty
::DebruijnIndex
,
304 impl<'tcx
> TyS
<'tcx
> {
305 /// A constructor used only for internal testing.
306 #[allow(rustc::usage_of_ty_tykind)]
307 pub fn make_for_test(
310 outer_exclusive_binder
: ty
::DebruijnIndex
,
312 TyS { kind, flags, outer_exclusive_binder }
316 // `TyS` is used a lot. Make sure it doesn't unintentionally get bigger.
317 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
318 static_assert_size
!(TyS
<'_
>, 40);
320 impl<'tcx
> Ord
for TyS
<'tcx
> {
321 fn cmp(&self, other
: &TyS
<'tcx
>) -> Ordering
{
322 self.kind().cmp(other
.kind())
326 impl<'tcx
> PartialOrd
for TyS
<'tcx
> {
327 fn partial_cmp(&self, other
: &TyS
<'tcx
>) -> Option
<Ordering
> {
328 Some(self.kind().cmp(other
.kind()))
332 impl<'tcx
> PartialEq
for TyS
<'tcx
> {
334 fn eq(&self, other
: &TyS
<'tcx
>) -> bool
{
338 impl<'tcx
> Eq
for TyS
<'tcx
> {}
340 impl<'tcx
> Hash
for TyS
<'tcx
> {
341 fn hash
<H
: Hasher
>(&self, s
: &mut H
) {
342 (self as *const TyS
<'_
>).hash(s
)
346 impl<'a
, 'tcx
> HashStable
<StableHashingContext
<'a
>> for TyS
<'tcx
> {
347 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
351 // The other fields just provide fast access to information that is
352 // also contained in `kind`, so no need to hash them.
355 outer_exclusive_binder
: _
,
358 kind
.hash_stable(hcx
, hasher
);
362 #[rustc_diagnostic_item = "Ty"]
363 pub type Ty
<'tcx
> = &'tcx TyS
<'tcx
>;
365 impl ty
::EarlyBoundRegion
{
366 /// Does this early bound region have a name? Early bound regions normally
367 /// always have names except when using anonymous lifetimes (`'_`).
368 pub fn has_name(&self) -> bool
{
369 self.name
!= kw
::UnderscoreLifetime
374 crate struct PredicateInner
<'tcx
> {
375 kind
: Binder
<'tcx
, PredicateKind
<'tcx
>>,
377 /// See the comment for the corresponding field of [TyS].
378 outer_exclusive_binder
: ty
::DebruijnIndex
,
381 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
382 static_assert_size
!(PredicateInner
<'_
>, 48);
384 #[derive(Clone, Copy, Lift)]
385 pub struct Predicate
<'tcx
> {
386 inner
: &'tcx PredicateInner
<'tcx
>,
389 impl<'tcx
> PartialEq
for Predicate
<'tcx
> {
390 fn eq(&self, other
: &Self) -> bool
{
391 // `self.kind` is always interned.
392 ptr
::eq(self.inner
, other
.inner
)
396 impl Hash
for Predicate
<'_
> {
397 fn hash
<H
: Hasher
>(&self, s
: &mut H
) {
398 (self.inner
as *const PredicateInner
<'_
>).hash(s
)
402 impl<'tcx
> Eq
for Predicate
<'tcx
> {}
404 impl<'tcx
> Predicate
<'tcx
> {
405 /// Gets the inner `Binder<'tcx, PredicateKind<'tcx>>`.
407 pub fn kind(self) -> Binder
<'tcx
, PredicateKind
<'tcx
>> {
412 impl<'a
, 'tcx
> HashStable
<StableHashingContext
<'a
>> for Predicate
<'tcx
> {
413 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
417 // The other fields just provide fast access to information that is
418 // also contained in `kind`, so no need to hash them.
420 outer_exclusive_binder
: _
,
423 kind
.hash_stable(hcx
, hasher
);
427 #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)]
428 #[derive(HashStable, TypeFoldable)]
429 pub enum PredicateKind
<'tcx
> {
430 /// Corresponds to `where Foo: Bar<A, B, C>`. `Foo` here would be
431 /// the `Self` type of the trait reference and `A`, `B`, and `C`
432 /// would be the type parameters.
434 /// A trait predicate will have `Constness::Const` if it originates
435 /// from a bound on a `const fn` without the `?const` opt-out (e.g.,
436 /// `const fn foobar<Foo: Bar>() {}`).
437 Trait(TraitPredicate
<'tcx
>, Constness
),
440 RegionOutlives(RegionOutlivesPredicate
<'tcx
>),
443 TypeOutlives(TypeOutlivesPredicate
<'tcx
>),
445 /// `where <T as TraitRef>::Name == X`, approximately.
446 /// See the `ProjectionPredicate` struct for details.
447 Projection(ProjectionPredicate
<'tcx
>),
449 /// No syntax: `T` well-formed.
450 WellFormed(GenericArg
<'tcx
>),
452 /// Trait must be object-safe.
455 /// No direct syntax. May be thought of as `where T: FnFoo<...>`
456 /// for some substitutions `...` and `T` being a closure type.
457 /// Satisfied (or refuted) once we know the closure's kind.
458 ClosureKind(DefId
, SubstsRef
<'tcx
>, ClosureKind
),
461 Subtype(SubtypePredicate
<'tcx
>),
463 /// Constant initializer must evaluate successfully.
464 ConstEvaluatable(ty
::WithOptConstParam
<DefId
>, SubstsRef
<'tcx
>),
466 /// Constants must be equal. The first component is the const that is expected.
467 ConstEquate(&'tcx Const
<'tcx
>, &'tcx Const
<'tcx
>),
469 /// Represents a type found in the environment that we can use for implied bounds.
471 /// Only used for Chalk.
472 TypeWellFormedFromEnv(Ty
<'tcx
>),
475 /// The crate outlives map is computed during typeck and contains the
476 /// outlives of every item in the local crate. You should not use it
477 /// directly, because to do so will make your pass dependent on the
478 /// HIR of every item in the local crate. Instead, use
479 /// `tcx.inferred_outlives_of()` to get the outlives for a *particular*
481 #[derive(HashStable, Debug)]
482 pub struct CratePredicatesMap
<'tcx
> {
483 /// For each struct with outlive bounds, maps to a vector of the
484 /// predicate of its outlive bounds. If an item has no outlives
485 /// bounds, it will have no entry.
486 pub predicates
: FxHashMap
<DefId
, &'tcx
[(Predicate
<'tcx
>, Span
)]>,
489 impl<'tcx
> Predicate
<'tcx
> {
490 /// Performs a substitution suitable for going from a
491 /// poly-trait-ref to supertraits that must hold if that
492 /// poly-trait-ref holds. This is slightly different from a normal
493 /// substitution in terms of what happens with bound regions. See
494 /// lengthy comment below for details.
495 pub fn subst_supertrait(
498 trait_ref
: &ty
::PolyTraitRef
<'tcx
>,
499 ) -> Predicate
<'tcx
> {
500 // The interaction between HRTB and supertraits is not entirely
501 // obvious. Let me walk you (and myself) through an example.
503 // Let's start with an easy case. Consider two traits:
505 // trait Foo<'a>: Bar<'a,'a> { }
506 // trait Bar<'b,'c> { }
508 // Now, if we have a trait reference `for<'x> T: Foo<'x>`, then
509 // we can deduce that `for<'x> T: Bar<'x,'x>`. Basically, if we
510 // knew that `Foo<'x>` (for any 'x) then we also know that
511 // `Bar<'x,'x>` (for any 'x). This more-or-less falls out from
512 // normal substitution.
514 // In terms of why this is sound, the idea is that whenever there
515 // is an impl of `T:Foo<'a>`, it must show that `T:Bar<'a,'a>`
516 // holds. So if there is an impl of `T:Foo<'a>` that applies to
517 // all `'a`, then we must know that `T:Bar<'a,'a>` holds for all
520 // Another example to be careful of is this:
522 // trait Foo1<'a>: for<'b> Bar1<'a,'b> { }
523 // trait Bar1<'b,'c> { }
525 // Here, if we have `for<'x> T: Foo1<'x>`, then what do we know?
526 // The answer is that we know `for<'x,'b> T: Bar1<'x,'b>`. The
527 // reason is similar to the previous example: any impl of
528 // `T:Foo1<'x>` must show that `for<'b> T: Bar1<'x, 'b>`. So
529 // basically we would want to collapse the bound lifetimes from
530 // the input (`trait_ref`) and the supertraits.
532 // To achieve this in practice is fairly straightforward. Let's
533 // consider the more complicated scenario:
535 // - We start out with `for<'x> T: Foo1<'x>`. In this case, `'x`
536 // has a De Bruijn index of 1. We want to produce `for<'x,'b> T: Bar1<'x,'b>`,
537 // where both `'x` and `'b` would have a DB index of 1.
538 // The substitution from the input trait-ref is therefore going to be
539 // `'a => 'x` (where `'x` has a DB index of 1).
540 // - The super-trait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an
541 // early-bound parameter and `'b' is a late-bound parameter with a
543 // - If we replace `'a` with `'x` from the input, it too will have
544 // a DB index of 1, and thus we'll have `for<'x,'b> Bar1<'x,'b>`
545 // just as we wanted.
547 // There is only one catch. If we just apply the substitution `'a
548 // => 'x` to `for<'b> Bar1<'a,'b>`, the substitution code will
549 // adjust the DB index because we substituting into a binder (it
550 // tries to be so smart...) resulting in `for<'x> for<'b>
551 // Bar1<'x,'b>` (we have no syntax for this, so use your
552 // imagination). Basically the 'x will have DB index of 2 and 'b
553 // will have DB index of 1. Not quite what we want. So we apply
554 // the substitution to the *contents* of the trait reference,
555 // rather than the trait reference itself (put another way, the
556 // substitution code expects equal binding levels in the values
557 // from the substitution and the value being substituted into, and
558 // this trick achieves that).
560 // Working through the second example:
561 // trait_ref: for<'x> T: Foo1<'^0.0>; substs: [T, '^0.0]
562 // predicate: for<'b> Self: Bar1<'a, '^0.0>; substs: [Self, 'a, '^0.0]
563 // We want to end up with:
564 // for<'x, 'b> T: Bar1<'^0.0, '^0.1>
566 // 1) We must shift all bound vars in predicate by the length
567 // of trait ref's bound vars. So, we would end up with predicate like
568 // Self: Bar1<'a, '^0.1>
569 // 2) We can then apply the trait substs to this, ending up with
570 // T: Bar1<'^0.0, '^0.1>
571 // 3) Finally, to create the final bound vars, we concatenate the bound
572 // vars of the trait ref with those of the predicate:
574 let bound_pred
= self.kind();
575 let pred_bound_vars
= bound_pred
.bound_vars();
576 let trait_bound_vars
= trait_ref
.bound_vars();
577 // 1) Self: Bar1<'a, '^0.0> -> Self: Bar1<'a, '^0.1>
579 tcx
.shift_bound_var_indices(trait_bound_vars
.len(), bound_pred
.skip_binder());
580 // 2) Self: Bar1<'a, '^0.1> -> T: Bar1<'^0.0, '^0.1>
581 let new
= shifted_pred
.subst(tcx
, trait_ref
.skip_binder().substs
);
582 // 3) ['x] + ['b] -> ['x, 'b]
584 tcx
.mk_bound_variable_kinds(trait_bound_vars
.iter().chain(pred_bound_vars
));
585 tcx
.reuse_or_mk_predicate(self, ty
::Binder
::bind_with_vars(new
, bound_vars
))
589 #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)]
590 #[derive(HashStable, TypeFoldable)]
591 pub struct TraitPredicate
<'tcx
> {
592 pub trait_ref
: TraitRef
<'tcx
>,
595 pub type PolyTraitPredicate
<'tcx
> = ty
::Binder
<'tcx
, TraitPredicate
<'tcx
>>;
597 impl<'tcx
> TraitPredicate
<'tcx
> {
598 pub fn def_id(self) -> DefId
{
599 self.trait_ref
.def_id
602 pub fn self_ty(self) -> Ty
<'tcx
> {
603 self.trait_ref
.self_ty()
607 impl<'tcx
> PolyTraitPredicate
<'tcx
> {
608 pub fn def_id(self) -> DefId
{
609 // Ok to skip binder since trait `DefId` does not care about regions.
610 self.skip_binder().def_id()
613 pub fn self_ty(self) -> ty
::Binder
<'tcx
, Ty
<'tcx
>> {
614 self.map_bound(|trait_ref
| trait_ref
.self_ty())
618 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, TyEncodable, TyDecodable)]
619 #[derive(HashStable, TypeFoldable)]
620 pub struct OutlivesPredicate
<A
, B
>(pub A
, pub B
); // `A: B`
621 pub type RegionOutlivesPredicate
<'tcx
> = OutlivesPredicate
<ty
::Region
<'tcx
>, ty
::Region
<'tcx
>>;
622 pub type TypeOutlivesPredicate
<'tcx
> = OutlivesPredicate
<Ty
<'tcx
>, ty
::Region
<'tcx
>>;
623 pub type PolyRegionOutlivesPredicate
<'tcx
> = ty
::Binder
<'tcx
, RegionOutlivesPredicate
<'tcx
>>;
624 pub type PolyTypeOutlivesPredicate
<'tcx
> = ty
::Binder
<'tcx
, TypeOutlivesPredicate
<'tcx
>>;
626 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, TyEncodable, TyDecodable)]
627 #[derive(HashStable, TypeFoldable)]
628 pub struct SubtypePredicate
<'tcx
> {
629 pub a_is_expected
: bool
,
633 pub type PolySubtypePredicate
<'tcx
> = ty
::Binder
<'tcx
, SubtypePredicate
<'tcx
>>;
635 /// This kind of predicate has no *direct* correspondent in the
636 /// syntax, but it roughly corresponds to the syntactic forms:
638 /// 1. `T: TraitRef<..., Item = Type>`
639 /// 2. `<T as TraitRef<...>>::Item == Type` (NYI)
641 /// In particular, form #1 is "desugared" to the combination of a
642 /// normal trait predicate (`T: TraitRef<...>`) and one of these
643 /// predicates. Form #2 is a broader form in that it also permits
644 /// equality between arbitrary types. Processing an instance of
645 /// Form #2 eventually yields one of these `ProjectionPredicate`
646 /// instances to normalize the LHS.
647 #[derive(Copy, Clone, PartialEq, Eq, Hash, TyEncodable, TyDecodable)]
648 #[derive(HashStable, TypeFoldable)]
649 pub struct ProjectionPredicate
<'tcx
> {
650 pub projection_ty
: ProjectionTy
<'tcx
>,
654 pub type PolyProjectionPredicate
<'tcx
> = Binder
<'tcx
, ProjectionPredicate
<'tcx
>>;
656 impl<'tcx
> PolyProjectionPredicate
<'tcx
> {
657 /// Returns the `DefId` of the trait of the associated item being projected.
659 pub fn trait_def_id(&self, tcx
: TyCtxt
<'tcx
>) -> DefId
{
660 self.skip_binder().projection_ty
.trait_def_id(tcx
)
663 /// Get the [PolyTraitRef] required for this projection to be well formed.
664 /// Note that for generic associated types the predicates of the associated
665 /// type also need to be checked.
667 pub fn required_poly_trait_ref(&self, tcx
: TyCtxt
<'tcx
>) -> PolyTraitRef
<'tcx
> {
668 // Note: unlike with `TraitRef::to_poly_trait_ref()`,
669 // `self.0.trait_ref` is permitted to have escaping regions.
670 // This is because here `self` has a `Binder` and so does our
671 // return value, so we are preserving the number of binding
673 self.map_bound(|predicate
| predicate
.projection_ty
.trait_ref(tcx
))
676 pub fn ty(&self) -> Binder
<'tcx
, Ty
<'tcx
>> {
677 self.map_bound(|predicate
| predicate
.ty
)
680 /// The `DefId` of the `TraitItem` for the associated type.
682 /// Note that this is not the `DefId` of the `TraitRef` containing this
683 /// associated type, which is in `tcx.associated_item(projection_def_id()).container`.
684 pub fn projection_def_id(&self) -> DefId
{
685 // Ok to skip binder since trait `DefId` does not care about regions.
686 self.skip_binder().projection_ty
.item_def_id
690 pub trait ToPolyTraitRef
<'tcx
> {
691 fn to_poly_trait_ref(&self) -> PolyTraitRef
<'tcx
>;
694 impl<'tcx
> ToPolyTraitRef
<'tcx
> for TraitRef
<'tcx
> {
695 fn to_poly_trait_ref(&self) -> PolyTraitRef
<'tcx
> {
696 ty
::Binder
::dummy(*self)
700 impl<'tcx
> ToPolyTraitRef
<'tcx
> for PolyTraitPredicate
<'tcx
> {
701 fn to_poly_trait_ref(&self) -> PolyTraitRef
<'tcx
> {
702 self.map_bound_ref(|trait_pred
| trait_pred
.trait_ref
)
706 pub trait ToPredicate
<'tcx
> {
707 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
>;
710 impl ToPredicate
<'tcx
> for Binder
<'tcx
, PredicateKind
<'tcx
>> {
712 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
713 tcx
.mk_predicate(self)
717 impl ToPredicate
<'tcx
> for PredicateKind
<'tcx
> {
719 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
720 tcx
.mk_predicate(Binder
::dummy(self))
724 impl<'tcx
> ToPredicate
<'tcx
> for ConstnessAnd
<TraitRef
<'tcx
>> {
725 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
726 PredicateKind
::Trait(ty
::TraitPredicate { trait_ref: self.value }
, self.constness
)
731 impl<'tcx
> ToPredicate
<'tcx
> for ConstnessAnd
<PolyTraitRef
<'tcx
>> {
732 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
734 .map_bound(|trait_ref
| {
735 PredicateKind
::Trait(ty
::TraitPredicate { trait_ref }
, self.constness
)
741 impl<'tcx
> ToPredicate
<'tcx
> for ConstnessAnd
<PolyTraitPredicate
<'tcx
>> {
742 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
743 self.value
.map_bound(|value
| PredicateKind
::Trait(value
, self.constness
)).to_predicate(tcx
)
747 impl<'tcx
> ToPredicate
<'tcx
> for PolyRegionOutlivesPredicate
<'tcx
> {
748 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
749 self.map_bound(PredicateKind
::RegionOutlives
).to_predicate(tcx
)
753 impl<'tcx
> ToPredicate
<'tcx
> for PolyTypeOutlivesPredicate
<'tcx
> {
754 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
755 self.map_bound(PredicateKind
::TypeOutlives
).to_predicate(tcx
)
759 impl<'tcx
> ToPredicate
<'tcx
> for PolyProjectionPredicate
<'tcx
> {
760 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
761 self.map_bound(PredicateKind
::Projection
).to_predicate(tcx
)
765 impl<'tcx
> Predicate
<'tcx
> {
766 pub fn to_opt_poly_trait_ref(self) -> Option
<ConstnessAnd
<PolyTraitRef
<'tcx
>>> {
767 let predicate
= self.kind();
768 match predicate
.skip_binder() {
769 PredicateKind
::Trait(t
, constness
) => {
770 Some(ConstnessAnd { constness, value: predicate.rebind(t.trait_ref) }
)
772 PredicateKind
::Projection(..)
773 | PredicateKind
::Subtype(..)
774 | PredicateKind
::RegionOutlives(..)
775 | PredicateKind
::WellFormed(..)
776 | PredicateKind
::ObjectSafe(..)
777 | PredicateKind
::ClosureKind(..)
778 | PredicateKind
::TypeOutlives(..)
779 | PredicateKind
::ConstEvaluatable(..)
780 | PredicateKind
::ConstEquate(..)
781 | PredicateKind
::TypeWellFormedFromEnv(..) => None
,
785 pub fn to_opt_type_outlives(self) -> Option
<PolyTypeOutlivesPredicate
<'tcx
>> {
786 let predicate
= self.kind();
787 match predicate
.skip_binder() {
788 PredicateKind
::TypeOutlives(data
) => Some(predicate
.rebind(data
)),
789 PredicateKind
::Trait(..)
790 | PredicateKind
::Projection(..)
791 | PredicateKind
::Subtype(..)
792 | PredicateKind
::RegionOutlives(..)
793 | PredicateKind
::WellFormed(..)
794 | PredicateKind
::ObjectSafe(..)
795 | PredicateKind
::ClosureKind(..)
796 | PredicateKind
::ConstEvaluatable(..)
797 | PredicateKind
::ConstEquate(..)
798 | PredicateKind
::TypeWellFormedFromEnv(..) => None
,
803 /// Represents the bounds declared on a particular set of type
804 /// parameters. Should eventually be generalized into a flag list of
805 /// where-clauses. You can obtain a `InstantiatedPredicates` list from a
806 /// `GenericPredicates` by using the `instantiate` method. Note that this method
807 /// reflects an important semantic invariant of `InstantiatedPredicates`: while
808 /// the `GenericPredicates` are expressed in terms of the bound type
809 /// parameters of the impl/trait/whatever, an `InstantiatedPredicates` instance
810 /// represented a set of bounds for some particular instantiation,
811 /// meaning that the generic parameters have been substituted with
816 /// struct Foo<T, U: Bar<T>> { ... }
818 /// Here, the `GenericPredicates` for `Foo` would contain a list of bounds like
819 /// `[[], [U:Bar<T>]]`. Now if there were some particular reference
820 /// like `Foo<isize,usize>`, then the `InstantiatedPredicates` would be `[[],
821 /// [usize:Bar<isize>]]`.
822 #[derive(Clone, Debug, TypeFoldable)]
823 pub struct InstantiatedPredicates
<'tcx
> {
824 pub predicates
: Vec
<Predicate
<'tcx
>>,
825 pub spans
: Vec
<Span
>,
828 impl<'tcx
> InstantiatedPredicates
<'tcx
> {
829 pub fn empty() -> InstantiatedPredicates
<'tcx
> {
830 InstantiatedPredicates { predicates: vec![], spans: vec![] }
833 pub fn is_empty(&self) -> bool
{
834 self.predicates
.is_empty()
838 #[derive(Copy, Clone, Debug, PartialEq, Eq, HashStable, TyEncodable, TyDecodable)]
839 pub struct OpaqueTypeKey
<'tcx
> {
841 pub substs
: SubstsRef
<'tcx
>,
844 rustc_index
::newtype_index
! {
845 /// "Universes" are used during type- and trait-checking in the
846 /// presence of `for<..>` binders to control what sets of names are
847 /// visible. Universes are arranged into a tree: the root universe
848 /// contains names that are always visible. Each child then adds a new
849 /// set of names that are visible, in addition to those of its parent.
850 /// We say that the child universe "extends" the parent universe with
853 /// To make this more concrete, consider this program:
857 /// fn bar<T>(x: T) {
858 /// let y: for<'a> fn(&'a u8, Foo) = ...;
862 /// The struct name `Foo` is in the root universe U0. But the type
863 /// parameter `T`, introduced on `bar`, is in an extended universe U1
864 /// -- i.e., within `bar`, we can name both `T` and `Foo`, but outside
865 /// of `bar`, we cannot name `T`. Then, within the type of `y`, the
866 /// region `'a` is in a universe U2 that extends U1, because we can
867 /// name it inside the fn type but not outside.
869 /// Universes are used to do type- and trait-checking around these
870 /// "forall" binders (also called **universal quantification**). The
871 /// idea is that when, in the body of `bar`, we refer to `T` as a
872 /// type, we aren't referring to any type in particular, but rather a
873 /// kind of "fresh" type that is distinct from all other types we have
874 /// actually declared. This is called a **placeholder** type, and we
875 /// use universes to talk about this. In other words, a type name in
876 /// universe 0 always corresponds to some "ground" type that the user
877 /// declared, but a type name in a non-zero universe is a placeholder
878 /// type -- an idealized representative of "types in general" that we
879 /// use for checking generic functions.
880 pub struct UniverseIndex
{
882 DEBUG_FORMAT
= "U{}",
887 pub const ROOT
: UniverseIndex
= UniverseIndex
::from_u32(0);
889 /// Returns the "next" universe index in order -- this new index
890 /// is considered to extend all previous universes. This
891 /// corresponds to entering a `forall` quantifier. So, for
892 /// example, suppose we have this type in universe `U`:
895 /// for<'a> fn(&'a u32)
898 /// Once we "enter" into this `for<'a>` quantifier, we are in a
899 /// new universe that extends `U` -- in this new universe, we can
900 /// name the region `'a`, but that region was not nameable from
901 /// `U` because it was not in scope there.
902 pub fn next_universe(self) -> UniverseIndex
{
903 UniverseIndex
::from_u32(self.private
.checked_add(1).unwrap())
906 /// Returns `true` if `self` can name a name from `other` -- in other words,
907 /// if the set of names in `self` is a superset of those in
908 /// `other` (`self >= other`).
909 pub fn can_name(self, other
: UniverseIndex
) -> bool
{
910 self.private
>= other
.private
913 /// Returns `true` if `self` cannot name some names from `other` -- in other
914 /// words, if the set of names in `self` is a strict subset of
915 /// those in `other` (`self < other`).
916 pub fn cannot_name(self, other
: UniverseIndex
) -> bool
{
917 self.private
< other
.private
921 /// The "placeholder index" fully defines a placeholder region, type, or const. Placeholders are
922 /// identified by both a universe, as well as a name residing within that universe. Distinct bound
923 /// regions/types/consts within the same universe simply have an unknown relationship to one
925 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TyEncodable, TyDecodable, PartialOrd, Ord)]
926 pub struct Placeholder
<T
> {
927 pub universe
: UniverseIndex
,
931 impl<'a
, T
> HashStable
<StableHashingContext
<'a
>> for Placeholder
<T
>
933 T
: HashStable
<StableHashingContext
<'a
>>,
935 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
936 self.universe
.hash_stable(hcx
, hasher
);
937 self.name
.hash_stable(hcx
, hasher
);
941 pub type PlaceholderRegion
= Placeholder
<BoundRegionKind
>;
943 pub type PlaceholderType
= Placeholder
<BoundVar
>;
945 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable)]
946 #[derive(TyEncodable, TyDecodable, PartialOrd, Ord)]
947 pub struct BoundConst
<'tcx
> {
952 pub type PlaceholderConst
<'tcx
> = Placeholder
<BoundConst
<'tcx
>>;
954 /// A `DefId` which, in case it is a const argument, is potentially bundled with
955 /// the `DefId` of the generic parameter it instantiates.
957 /// This is used to avoid calls to `type_of` for const arguments during typeck
958 /// which cause cycle errors.
963 /// fn foo<const N: usize>(&self) -> [u8; N] { [0; N] }
964 /// // ^ const parameter
968 /// fn foo<const M: u8>(&self) -> usize { 42 }
969 /// // ^ const parameter
974 /// let _b = a.foo::<{ 3 + 7 }>();
975 /// // ^^^^^^^^^ const argument
979 /// Let's look at the call `a.foo::<{ 3 + 7 }>()` here. We do not know
980 /// which `foo` is used until we know the type of `a`.
982 /// We only know the type of `a` once we are inside of `typeck(main)`.
983 /// We also end up normalizing the type of `_b` during `typeck(main)` which
984 /// requires us to evaluate the const argument.
986 /// To evaluate that const argument we need to know its type,
987 /// which we would get using `type_of(const_arg)`. This requires us to
988 /// resolve `foo` as it can be either `usize` or `u8` in this example.
989 /// However, resolving `foo` once again requires `typeck(main)` to get the type of `a`,
990 /// which results in a cycle.
992 /// In short we must not call `type_of(const_arg)` during `typeck(main)`.
994 /// When first creating the `ty::Const` of the const argument inside of `typeck` we have
995 /// already resolved `foo` so we know which const parameter this argument instantiates.
996 /// This means that we also know the expected result of `type_of(const_arg)` even if we
997 /// aren't allowed to call that query: it is equal to `type_of(const_param)` which is
998 /// trivial to compute.
1000 /// If we now want to use that constant in a place which potentionally needs its type
1001 /// we also pass the type of its `const_param`. This is the point of `WithOptConstParam`,
1002 /// except that instead of a `Ty` we bundle the `DefId` of the const parameter.
1003 /// Meaning that we need to use `type_of(const_param_did)` if `const_param_did` is `Some`
1004 /// to get the type of `did`.
1005 #[derive(Copy, Clone, Debug, TypeFoldable, Lift, TyEncodable, TyDecodable)]
1006 #[derive(PartialEq, Eq, PartialOrd, Ord)]
1007 #[derive(Hash, HashStable)]
1008 pub struct WithOptConstParam
<T
> {
1010 /// The `DefId` of the corresponding generic parameter in case `did` is
1011 /// a const argument.
1013 /// Note that even if `did` is a const argument, this may still be `None`.
1014 /// All queries taking `WithOptConstParam` start by calling `tcx.opt_const_param_of(def.did)`
1015 /// to potentially update `param_did` in the case it is `None`.
1016 pub const_param_did
: Option
<DefId
>,
1019 impl<T
> WithOptConstParam
<T
> {
1020 /// Creates a new `WithOptConstParam` setting `const_param_did` to `None`.
1022 pub fn unknown(did
: T
) -> WithOptConstParam
<T
> {
1023 WithOptConstParam { did, const_param_did: None }
1027 impl WithOptConstParam
<LocalDefId
> {
1028 /// Returns `Some((did, param_did))` if `def_id` is a const argument,
1029 /// `None` otherwise.
1031 pub fn try_lookup(did
: LocalDefId
, tcx
: TyCtxt
<'_
>) -> Option
<(LocalDefId
, DefId
)> {
1032 tcx
.opt_const_param_of(did
).map(|param_did
| (did
, param_did
))
1035 /// In case `self` is unknown but `self.did` is a const argument, this returns
1036 /// a `WithOptConstParam` with the correct `const_param_did`.
1038 pub fn try_upgrade(self, tcx
: TyCtxt
<'_
>) -> Option
<WithOptConstParam
<LocalDefId
>> {
1039 if self.const_param_did
.is_none() {
1040 if let const_param_did @
Some(_
) = tcx
.opt_const_param_of(self.did
) {
1041 return Some(WithOptConstParam { did: self.did, const_param_did }
);
1048 pub fn to_global(self) -> WithOptConstParam
<DefId
> {
1049 WithOptConstParam { did: self.did.to_def_id(), const_param_did: self.const_param_did }
1052 pub fn def_id_for_type_of(self) -> DefId
{
1053 if let Some(did
) = self.const_param_did { did }
else { self.did.to_def_id() }
1057 impl WithOptConstParam
<DefId
> {
1058 pub fn as_local(self) -> Option
<WithOptConstParam
<LocalDefId
>> {
1061 .map(|did
| WithOptConstParam { did, const_param_did: self.const_param_did }
)
1064 pub fn as_const_arg(self) -> Option
<(LocalDefId
, DefId
)> {
1065 if let Some(param_did
) = self.const_param_did
{
1066 if let Some(did
) = self.did
.as_local() {
1067 return Some((did
, param_did
));
1074 pub fn is_local(self) -> bool
{
1078 pub fn def_id_for_type_of(self) -> DefId
{
1079 self.const_param_did
.unwrap_or(self.did
)
1083 /// When type checking, we use the `ParamEnv` to track
1084 /// details about the set of where-clauses that are in scope at this
1085 /// particular point.
1086 #[derive(Copy, Clone, Hash, PartialEq, Eq)]
1087 pub struct ParamEnv
<'tcx
> {
1088 /// This packs both caller bounds and the reveal enum into one pointer.
1090 /// Caller bounds are `Obligation`s that the caller must satisfy. This is
1091 /// basically the set of bounds on the in-scope type parameters, translated
1092 /// into `Obligation`s, and elaborated and normalized.
1094 /// Use the `caller_bounds()` method to access.
1096 /// Typically, this is `Reveal::UserFacing`, but during codegen we
1097 /// want `Reveal::All`.
1099 /// Note: This is packed, use the reveal() method to access it.
1100 packed
: CopyTaggedPtr
<&'tcx List
<Predicate
<'tcx
>>, traits
::Reveal
, true>,
1103 unsafe impl rustc_data_structures
::tagged_ptr
::Tag
for traits
::Reveal
{
1104 const BITS
: usize = 1;
1106 fn into_usize(self) -> usize {
1108 traits
::Reveal
::UserFacing
=> 0,
1109 traits
::Reveal
::All
=> 1,
1113 unsafe fn from_usize(ptr
: usize) -> Self {
1115 0 => traits
::Reveal
::UserFacing
,
1116 1 => traits
::Reveal
::All
,
1117 _
=> std
::hint
::unreachable_unchecked(),
1122 impl<'tcx
> fmt
::Debug
for ParamEnv
<'tcx
> {
1123 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
1124 f
.debug_struct("ParamEnv")
1125 .field("caller_bounds", &self.caller_bounds())
1126 .field("reveal", &self.reveal())
1131 impl<'a
, 'tcx
> HashStable
<StableHashingContext
<'a
>> for ParamEnv
<'tcx
> {
1132 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
1133 self.caller_bounds().hash_stable(hcx
, hasher
);
1134 self.reveal().hash_stable(hcx
, hasher
);
1138 impl<'tcx
> TypeFoldable
<'tcx
> for ParamEnv
<'tcx
> {
1139 fn super_fold_with
<F
: ty
::fold
::TypeFolder
<'tcx
>>(self, folder
: &mut F
) -> Self {
1140 ParamEnv
::new(self.caller_bounds().fold_with(folder
), self.reveal().fold_with(folder
))
1143 fn super_visit_with
<V
: TypeVisitor
<'tcx
>>(&self, visitor
: &mut V
) -> ControlFlow
<V
::BreakTy
> {
1144 self.caller_bounds().visit_with(visitor
)?
;
1145 self.reveal().visit_with(visitor
)
1149 impl<'tcx
> ParamEnv
<'tcx
> {
1150 /// Construct a trait environment suitable for contexts where
1151 /// there are no where-clauses in scope. Hidden types (like `impl
1152 /// Trait`) are left hidden, so this is suitable for ordinary
1155 pub fn empty() -> Self {
1156 Self::new(List
::empty(), Reveal
::UserFacing
)
1160 pub fn caller_bounds(self) -> &'tcx List
<Predicate
<'tcx
>> {
1161 self.packed
.pointer()
1165 pub fn reveal(self) -> traits
::Reveal
{
1169 /// Construct a trait environment with no where-clauses in scope
1170 /// where the values of all `impl Trait` and other hidden types
1171 /// are revealed. This is suitable for monomorphized, post-typeck
1172 /// environments like codegen or doing optimizations.
1174 /// N.B., if you want to have predicates in scope, use `ParamEnv::new`,
1175 /// or invoke `param_env.with_reveal_all()`.
1177 pub fn reveal_all() -> Self {
1178 Self::new(List
::empty(), Reveal
::All
)
1181 /// Construct a trait environment with the given set of predicates.
1183 pub fn new(caller_bounds
: &'tcx List
<Predicate
<'tcx
>>, reveal
: Reveal
) -> Self {
1184 ty
::ParamEnv { packed: CopyTaggedPtr::new(caller_bounds, reveal) }
1187 pub fn with_user_facing(mut self) -> Self {
1188 self.packed
.set_tag(Reveal
::UserFacing
);
1192 /// Returns a new parameter environment with the same clauses, but
1193 /// which "reveals" the true results of projections in all cases
1194 /// (even for associated types that are specializable). This is
1195 /// the desired behavior during codegen and certain other special
1196 /// contexts; normally though we want to use `Reveal::UserFacing`,
1197 /// which is the default.
1198 /// All opaque types in the caller_bounds of the `ParamEnv`
1199 /// will be normalized to their underlying types.
1200 /// See PR #65989 and issue #65918 for more details
1201 pub fn with_reveal_all_normalized(self, tcx
: TyCtxt
<'tcx
>) -> Self {
1202 if self.packed
.tag() == traits
::Reveal
::All
{
1206 ParamEnv
::new(tcx
.normalize_opaque_types(self.caller_bounds()), Reveal
::All
)
1209 /// Returns this same environment but with no caller bounds.
1211 pub fn without_caller_bounds(self) -> Self {
1212 Self::new(List
::empty(), self.reveal())
1215 /// Creates a suitable environment in which to perform trait
1216 /// queries on the given value. When type-checking, this is simply
1217 /// the pair of the environment plus value. But when reveal is set to
1218 /// All, then if `value` does not reference any type parameters, we will
1219 /// pair it with the empty environment. This improves caching and is generally
1222 /// N.B., we preserve the environment when type-checking because it
1223 /// is possible for the user to have wacky where-clauses like
1224 /// `where Box<u32>: Copy`, which are clearly never
1225 /// satisfiable. We generally want to behave as if they were true,
1226 /// although the surrounding function is never reachable.
1227 pub fn and
<T
: TypeFoldable
<'tcx
>>(self, value
: T
) -> ParamEnvAnd
<'tcx
, T
> {
1228 match self.reveal() {
1229 Reveal
::UserFacing
=> ParamEnvAnd { param_env: self, value }
,
1232 if value
.is_global() {
1233 ParamEnvAnd { param_env: self.without_caller_bounds(), value }
1235 ParamEnvAnd { param_env: self, value }
1242 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TypeFoldable)]
1243 pub struct ConstnessAnd
<T
> {
1244 pub constness
: Constness
,
1248 // FIXME(ecstaticmorse): Audit all occurrences of `without_const().to_predicate(tcx)` to ensure that
1249 // the constness of trait bounds is being propagated correctly.
1250 pub trait WithConstness
: Sized
{
1252 fn with_constness(self, constness
: Constness
) -> ConstnessAnd
<Self> {
1253 ConstnessAnd { constness, value: self }
1257 fn with_const(self) -> ConstnessAnd
<Self> {
1258 self.with_constness(Constness
::Const
)
1262 fn without_const(self) -> ConstnessAnd
<Self> {
1263 self.with_constness(Constness
::NotConst
)
1267 impl<T
> WithConstness
for T {}
1269 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TypeFoldable)]
1270 pub struct ParamEnvAnd
<'tcx
, T
> {
1271 pub param_env
: ParamEnv
<'tcx
>,
1275 impl<'tcx
, T
> ParamEnvAnd
<'tcx
, T
> {
1276 pub fn into_parts(self) -> (ParamEnv
<'tcx
>, T
) {
1277 (self.param_env
, self.value
)
1281 impl<'a
, 'tcx
, T
> HashStable
<StableHashingContext
<'a
>> for ParamEnvAnd
<'tcx
, T
>
1283 T
: HashStable
<StableHashingContext
<'a
>>,
1285 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
1286 let ParamEnvAnd { ref param_env, ref value }
= *self;
1288 param_env
.hash_stable(hcx
, hasher
);
1289 value
.hash_stable(hcx
, hasher
);
1293 #[derive(Copy, Clone, Debug, HashStable)]
1294 pub struct Destructor
{
1295 /// The `DefId` of the destructor method
1300 #[derive(HashStable)]
1301 pub struct VariantFlags
: u32 {
1302 const NO_VARIANT_FLAGS
= 0;
1303 /// Indicates whether the field list of this variant is `#[non_exhaustive]`.
1304 const IS_FIELD_LIST_NON_EXHAUSTIVE
= 1 << 0;
1305 /// Indicates whether this variant was obtained as part of recovering from
1306 /// a syntactic error. May be incomplete or bogus.
1307 const IS_RECOVERED
= 1 << 1;
1311 /// Definition of a variant -- a struct's fields or a enum variant.
1312 #[derive(Debug, HashStable)]
1313 pub struct VariantDef
{
1314 /// `DefId` that identifies the variant itself.
1315 /// If this variant belongs to a struct or union, then this is a copy of its `DefId`.
1317 /// `DefId` that identifies the variant's constructor.
1318 /// If this variant is a struct variant, then this is `None`.
1319 pub ctor_def_id
: Option
<DefId
>,
1320 /// Variant or struct name.
1321 #[stable_hasher(project(name))]
1323 /// Discriminant of this variant.
1324 pub discr
: VariantDiscr
,
1325 /// Fields of this variant.
1326 pub fields
: Vec
<FieldDef
>,
1327 /// Type of constructor of variant.
1328 pub ctor_kind
: CtorKind
,
1329 /// Flags of the variant (e.g. is field list non-exhaustive)?
1330 flags
: VariantFlags
,
1334 /// Creates a new `VariantDef`.
1336 /// `variant_did` is the `DefId` that identifies the enum variant (if this `VariantDef`
1337 /// represents an enum variant).
1339 /// `ctor_did` is the `DefId` that identifies the constructor of unit or
1340 /// tuple-variants/structs. If this is a `struct`-variant then this should be `None`.
1342 /// `parent_did` is the `DefId` of the `AdtDef` representing the enum or struct that
1343 /// owns this variant. It is used for checking if a struct has `#[non_exhaustive]` w/out having
1344 /// to go through the redirect of checking the ctor's attributes - but compiling a small crate
1345 /// requires loading the `AdtDef`s for all the structs in the universe (e.g., coherence for any
1346 /// built-in trait), and we do not want to load attributes twice.
1348 /// If someone speeds up attribute loading to not be a performance concern, they can
1349 /// remove this hack and use the constructor `DefId` everywhere.
1352 variant_did
: Option
<DefId
>,
1353 ctor_def_id
: Option
<DefId
>,
1354 discr
: VariantDiscr
,
1355 fields
: Vec
<FieldDef
>,
1356 ctor_kind
: CtorKind
,
1360 is_field_list_non_exhaustive
: bool
,
1363 "VariantDef::new(ident = {:?}, variant_did = {:?}, ctor_def_id = {:?}, discr = {:?},
1364 fields = {:?}, ctor_kind = {:?}, adt_kind = {:?}, parent_did = {:?})",
1365 ident
, variant_did
, ctor_def_id
, discr
, fields
, ctor_kind
, adt_kind
, parent_did
,
1368 let mut flags
= VariantFlags
::NO_VARIANT_FLAGS
;
1369 if is_field_list_non_exhaustive
{
1370 flags
|= VariantFlags
::IS_FIELD_LIST_NON_EXHAUSTIVE
;
1374 flags
|= VariantFlags
::IS_RECOVERED
;
1378 def_id
: variant_did
.unwrap_or(parent_did
),
1388 /// Is this field list non-exhaustive?
1390 pub fn is_field_list_non_exhaustive(&self) -> bool
{
1391 self.flags
.intersects(VariantFlags
::IS_FIELD_LIST_NON_EXHAUSTIVE
)
1394 /// Was this variant obtained as part of recovering from a syntactic error?
1396 pub fn is_recovered(&self) -> bool
{
1397 self.flags
.intersects(VariantFlags
::IS_RECOVERED
)
1401 #[derive(Copy, Clone, Debug, PartialEq, Eq, TyEncodable, TyDecodable, HashStable)]
1402 pub enum VariantDiscr
{
1403 /// Explicit value for this variant, i.e., `X = 123`.
1404 /// The `DefId` corresponds to the embedded constant.
1407 /// The previous variant's discriminant plus one.
1408 /// For efficiency reasons, the distance from the
1409 /// last `Explicit` discriminant is being stored,
1410 /// or `0` for the first variant, if it has none.
1414 #[derive(Debug, HashStable)]
1415 pub struct FieldDef
{
1417 #[stable_hasher(project(name))]
1419 pub vis
: Visibility
,
1423 #[derive(TyEncodable, TyDecodable, Default, HashStable)]
1424 pub struct ReprFlags
: u8 {
1425 const IS_C
= 1 << 0;
1426 const IS_SIMD
= 1 << 1;
1427 const IS_TRANSPARENT
= 1 << 2;
1428 // Internal only for now. If true, don't reorder fields.
1429 const IS_LINEAR
= 1 << 3;
1430 // If true, don't expose any niche to type's context.
1431 const HIDE_NICHE
= 1 << 4;
1432 // Any of these flags being set prevent field reordering optimisation.
1433 const IS_UNOPTIMISABLE
= ReprFlags
::IS_C
.bits
|
1434 ReprFlags
::IS_SIMD
.bits
|
1435 ReprFlags
::IS_LINEAR
.bits
;
1439 /// Represents the repr options provided by the user,
1440 #[derive(Copy, Clone, Debug, Eq, PartialEq, TyEncodable, TyDecodable, Default, HashStable)]
1441 pub struct ReprOptions
{
1442 pub int
: Option
<attr
::IntType
>,
1443 pub align
: Option
<Align
>,
1444 pub pack
: Option
<Align
>,
1445 pub flags
: ReprFlags
,
1449 pub fn new(tcx
: TyCtxt
<'_
>, did
: DefId
) -> ReprOptions
{
1450 let mut flags
= ReprFlags
::empty();
1451 let mut size
= None
;
1452 let mut max_align
: Option
<Align
> = None
;
1453 let mut min_pack
: Option
<Align
> = None
;
1454 for attr
in tcx
.get_attrs(did
).iter() {
1455 for r
in attr
::find_repr_attrs(&tcx
.sess
, attr
) {
1456 flags
.insert(match r
{
1457 attr
::ReprC
=> ReprFlags
::IS_C
,
1458 attr
::ReprPacked(pack
) => {
1459 let pack
= Align
::from_bytes(pack
as u64).unwrap();
1460 min_pack
= Some(if let Some(min_pack
) = min_pack
{
1467 attr
::ReprTransparent
=> ReprFlags
::IS_TRANSPARENT
,
1468 attr
::ReprNoNiche
=> ReprFlags
::HIDE_NICHE
,
1469 attr
::ReprSimd
=> ReprFlags
::IS_SIMD
,
1470 attr
::ReprInt(i
) => {
1474 attr
::ReprAlign(align
) => {
1475 max_align
= max_align
.max(Some(Align
::from_bytes(align
as u64).unwrap()));
1482 // This is here instead of layout because the choice must make it into metadata.
1483 if !tcx
.consider_optimizing(|| format
!("Reorder fields of {:?}", tcx
.def_path_str(did
))) {
1484 flags
.insert(ReprFlags
::IS_LINEAR
);
1486 ReprOptions { int: size, align: max_align, pack: min_pack, flags }
1490 pub fn simd(&self) -> bool
{
1491 self.flags
.contains(ReprFlags
::IS_SIMD
)
1494 pub fn c(&self) -> bool
{
1495 self.flags
.contains(ReprFlags
::IS_C
)
1498 pub fn packed(&self) -> bool
{
1502 pub fn transparent(&self) -> bool
{
1503 self.flags
.contains(ReprFlags
::IS_TRANSPARENT
)
1506 pub fn linear(&self) -> bool
{
1507 self.flags
.contains(ReprFlags
::IS_LINEAR
)
1510 pub fn hide_niche(&self) -> bool
{
1511 self.flags
.contains(ReprFlags
::HIDE_NICHE
)
1514 /// Returns the discriminant type, given these `repr` options.
1515 /// This must only be called on enums!
1516 pub fn discr_type(&self) -> attr
::IntType
{
1517 self.int
.unwrap_or(attr
::SignedInt(ast
::IntTy
::Isize
))
1520 /// Returns `true` if this `#[repr()]` should inhabit "smart enum
1521 /// layout" optimizations, such as representing `Foo<&T>` as a
1523 pub fn inhibit_enum_layout_opt(&self) -> bool
{
1524 self.c() || self.int
.is_some()
1527 /// Returns `true` if this `#[repr()]` should inhibit struct field reordering
1528 /// optimizations, such as with `repr(C)`, `repr(packed(1))`, or `repr(<int>)`.
1529 pub fn inhibit_struct_field_reordering_opt(&self) -> bool
{
1530 if let Some(pack
) = self.pack
{
1531 if pack
.bytes() == 1 {
1535 self.flags
.intersects(ReprFlags
::IS_UNOPTIMISABLE
) || self.int
.is_some()
1538 /// Returns `true` if this `#[repr()]` should inhibit union ABI optimisations.
1539 pub fn inhibit_union_abi_opt(&self) -> bool
{
1544 impl<'tcx
> FieldDef
{
1545 /// Returns the type of this field. The `subst` is typically obtained
1546 /// via the second field of `TyKind::AdtDef`.
1547 pub fn ty(&self, tcx
: TyCtxt
<'tcx
>, subst
: SubstsRef
<'tcx
>) -> Ty
<'tcx
> {
1548 tcx
.type_of(self.did
).subst(tcx
, subst
)
1552 pub type Attributes
<'tcx
> = &'tcx
[ast
::Attribute
];
1554 #[derive(Debug, PartialEq, Eq)]
1555 pub enum ImplOverlapKind
{
1556 /// These impls are always allowed to overlap.
1558 /// Whether or not the impl is permitted due to the trait being a `#[marker]` trait
1561 /// These impls are allowed to overlap, but that raises
1562 /// an issue #33140 future-compatibility warning.
1564 /// Some background: in Rust 1.0, the trait-object types `Send + Sync` (today's
1565 /// `dyn Send + Sync`) and `Sync + Send` (now `dyn Sync + Send`) were different.
1567 /// The widely-used version 0.1.0 of the crate `traitobject` had accidentally relied
1568 /// that difference, making what reduces to the following set of impls:
1572 /// impl Trait for dyn Send + Sync {}
1573 /// impl Trait for dyn Sync + Send {}
1576 /// Obviously, once we made these types be identical, that code causes a coherence
1577 /// error and a fairly big headache for us. However, luckily for us, the trait
1578 /// `Trait` used in this case is basically a marker trait, and therefore having
1579 /// overlapping impls for it is sound.
1581 /// To handle this, we basically regard the trait as a marker trait, with an additional
1582 /// future-compatibility warning. To avoid accidentally "stabilizing" this feature,
1583 /// it has the following restrictions:
1585 /// 1. The trait must indeed be a marker-like trait (i.e., no items), and must be
1587 /// 2. The trait-ref of both impls must be equal.
1588 /// 3. The trait-ref of both impls must be a trait object type consisting only of
1590 /// 4. Neither of the impls can have any where-clauses.
1592 /// Once `traitobject` 0.1.0 is no longer an active concern, this hack can be removed.
1596 impl<'tcx
> TyCtxt
<'tcx
> {
1597 pub fn typeck_body(self, body
: hir
::BodyId
) -> &'tcx TypeckResults
<'tcx
> {
1598 self.typeck(self.hir().body_owner_def_id(body
))
1601 /// Returns an iterator of the `DefId`s for all body-owners in this
1602 /// crate. If you would prefer to iterate over the bodies
1603 /// themselves, you can do `self.hir().krate().body_ids.iter()`.
1604 pub fn body_owners(self) -> impl Iterator
<Item
= LocalDefId
> + Captures
<'tcx
> + 'tcx
{
1609 .map(move |&body_id
| self.hir().body_owner_def_id(body_id
))
1612 pub fn par_body_owners
<F
: Fn(LocalDefId
) + sync
::Sync
+ sync
::Send
>(self, f
: F
) {
1613 par_iter(&self.hir().krate().body_ids
)
1614 .for_each(|&body_id
| f(self.hir().body_owner_def_id(body_id
)));
1617 pub fn provided_trait_methods(self, id
: DefId
) -> impl 'tcx
+ Iterator
<Item
= &'tcx AssocItem
> {
1618 self.associated_items(id
)
1619 .in_definition_order()
1620 .filter(|item
| item
.kind
== AssocKind
::Fn
&& item
.defaultness
.has_value())
1623 fn item_name_from_hir(self, def_id
: DefId
) -> Option
<Ident
> {
1624 self.hir().get_if_local(def_id
).and_then(|node
| node
.ident())
1627 fn item_name_from_def_id(self, def_id
: DefId
) -> Option
<Symbol
> {
1628 if def_id
.index
== CRATE_DEF_INDEX
{
1629 Some(self.crate_name(def_id
.krate
))
1631 let def_key
= self.def_key(def_id
);
1632 match def_key
.disambiguated_data
.data
{
1633 // The name of a constructor is that of its parent.
1634 rustc_hir
::definitions
::DefPathData
::Ctor
=> self.item_name_from_def_id(DefId
{
1635 krate
: def_id
.krate
,
1636 index
: def_key
.parent
.unwrap(),
1638 _
=> def_key
.disambiguated_data
.data
.get_opt_name(),
1643 /// Look up the name of an item across crates. This does not look at HIR.
1645 /// When possible, this function should be used for cross-crate lookups over
1646 /// [`opt_item_name`] to avoid invalidating the incremental cache. If you
1647 /// need to handle items without a name, or HIR items that will not be
1648 /// serialized cross-crate, or if you need the span of the item, use
1649 /// [`opt_item_name`] instead.
1651 /// [`opt_item_name`]: Self::opt_item_name
1652 pub fn item_name(self, id
: DefId
) -> Symbol
{
1653 // Look at cross-crate items first to avoid invalidating the incremental cache
1654 // unless we have to.
1655 self.item_name_from_def_id(id
).unwrap_or_else(|| {
1656 bug
!("item_name: no name for {:?}", self.def_path(id
));
1660 /// Look up the name and span of an item or [`Node`].
1662 /// See [`item_name`][Self::item_name] for more information.
1663 pub fn opt_item_name(self, def_id
: DefId
) -> Option
<Ident
> {
1664 // Look at the HIR first so the span will be correct if this is a local item.
1665 self.item_name_from_hir(def_id
)
1666 .or_else(|| self.item_name_from_def_id(def_id
).map(Ident
::with_dummy_span
))
1669 pub fn opt_associated_item(self, def_id
: DefId
) -> Option
<&'tcx AssocItem
> {
1670 if let DefKind
::AssocConst
| DefKind
::AssocFn
| DefKind
::AssocTy
= self.def_kind(def_id
) {
1671 Some(self.associated_item(def_id
))
1677 pub fn field_index(self, hir_id
: hir
::HirId
, typeck_results
: &TypeckResults
<'_
>) -> usize {
1678 typeck_results
.field_indices().get(hir_id
).cloned().expect("no index for a field")
1681 pub fn find_field_index(self, ident
: Ident
, variant
: &VariantDef
) -> Option
<usize> {
1682 variant
.fields
.iter().position(|field
| self.hygienic_eq(ident
, field
.ident
, variant
.def_id
))
1685 /// Returns `true` if the impls are the same polarity and the trait either
1686 /// has no items or is annotated `#[marker]` and prevents item overrides.
1687 pub fn impls_are_allowed_to_overlap(
1691 ) -> Option
<ImplOverlapKind
> {
1692 // If either trait impl references an error, they're allowed to overlap,
1693 // as one of them essentially doesn't exist.
1694 if self.impl_trait_ref(def_id1
).map_or(false, |tr
| tr
.references_error())
1695 || self.impl_trait_ref(def_id2
).map_or(false, |tr
| tr
.references_error())
1697 return Some(ImplOverlapKind
::Permitted { marker: false }
);
1700 match (self.impl_polarity(def_id1
), self.impl_polarity(def_id2
)) {
1701 (ImplPolarity
::Reservation
, _
) | (_
, ImplPolarity
::Reservation
) => {
1702 // `#[rustc_reservation_impl]` impls don't overlap with anything
1704 "impls_are_allowed_to_overlap({:?}, {:?}) = Some(Permitted) (reservations)",
1707 return Some(ImplOverlapKind
::Permitted { marker: false }
);
1709 (ImplPolarity
::Positive
, ImplPolarity
::Negative
)
1710 | (ImplPolarity
::Negative
, ImplPolarity
::Positive
) => {
1711 // `impl AutoTrait for Type` + `impl !AutoTrait for Type`
1713 "impls_are_allowed_to_overlap({:?}, {:?}) - None (differing polarities)",
1718 (ImplPolarity
::Positive
, ImplPolarity
::Positive
)
1719 | (ImplPolarity
::Negative
, ImplPolarity
::Negative
) => {}
1722 let is_marker_overlap
= {
1723 let is_marker_impl
= |def_id
: DefId
| -> bool
{
1724 let trait_ref
= self.impl_trait_ref(def_id
);
1725 trait_ref
.map_or(false, |tr
| self.trait_def(tr
.def_id
).is_marker
)
1727 is_marker_impl(def_id1
) && is_marker_impl(def_id2
)
1730 if is_marker_overlap
{
1732 "impls_are_allowed_to_overlap({:?}, {:?}) = Some(Permitted) (marker overlap)",
1735 Some(ImplOverlapKind
::Permitted { marker: true }
)
1737 if let Some(self_ty1
) = self.issue33140_self_ty(def_id1
) {
1738 if let Some(self_ty2
) = self.issue33140_self_ty(def_id2
) {
1739 if self_ty1
== self_ty2
{
1741 "impls_are_allowed_to_overlap({:?}, {:?}) - issue #33140 HACK",
1744 return Some(ImplOverlapKind
::Issue33140
);
1747 "impls_are_allowed_to_overlap({:?}, {:?}) - found {:?} != {:?}",
1748 def_id1
, def_id2
, self_ty1
, self_ty2
1754 debug
!("impls_are_allowed_to_overlap({:?}, {:?}) = None", def_id1
, def_id2
);
1759 /// Returns `ty::VariantDef` if `res` refers to a struct,
1760 /// or variant or their constructors, panics otherwise.
1761 pub fn expect_variant_res(self, res
: Res
) -> &'tcx VariantDef
{
1763 Res
::Def(DefKind
::Variant
, did
) => {
1764 let enum_did
= self.parent(did
).unwrap();
1765 self.adt_def(enum_did
).variant_with_id(did
)
1767 Res
::Def(DefKind
::Struct
| DefKind
::Union
, did
) => self.adt_def(did
).non_enum_variant(),
1768 Res
::Def(DefKind
::Ctor(CtorOf
::Variant
, ..), variant_ctor_did
) => {
1769 let variant_did
= self.parent(variant_ctor_did
).unwrap();
1770 let enum_did
= self.parent(variant_did
).unwrap();
1771 self.adt_def(enum_did
).variant_with_ctor_id(variant_ctor_did
)
1773 Res
::Def(DefKind
::Ctor(CtorOf
::Struct
, ..), ctor_did
) => {
1774 let struct_did
= self.parent(ctor_did
).expect("struct ctor has no parent");
1775 self.adt_def(struct_did
).non_enum_variant()
1777 _
=> bug
!("expect_variant_res used with unexpected res {:?}", res
),
1781 /// Returns the possibly-auto-generated MIR of a `(DefId, Subst)` pair.
1782 pub fn instance_mir(self, instance
: ty
::InstanceDef
<'tcx
>) -> &'tcx Body
<'tcx
> {
1784 ty
::InstanceDef
::Item(def
) => match self.def_kind(def
.did
) {
1787 | DefKind
::AssocConst
1789 | DefKind
::AnonConst
=> self.mir_for_ctfe_opt_const_arg(def
),
1790 // If the caller wants `mir_for_ctfe` of a function they should not be using
1791 // `instance_mir`, so we'll assume const fn also wants the optimized version.
1793 assert_eq
!(def
.const_param_did
, None
);
1794 self.optimized_mir(def
.did
)
1797 ty
::InstanceDef
::VtableShim(..)
1798 | ty
::InstanceDef
::ReifyShim(..)
1799 | ty
::InstanceDef
::Intrinsic(..)
1800 | ty
::InstanceDef
::FnPtrShim(..)
1801 | ty
::InstanceDef
::Virtual(..)
1802 | ty
::InstanceDef
::ClosureOnceShim { .. }
1803 | ty
::InstanceDef
::DropGlue(..)
1804 | ty
::InstanceDef
::CloneShim(..) => self.mir_shims(instance
),
1808 /// Gets the attributes of a definition.
1809 pub fn get_attrs(self, did
: DefId
) -> Attributes
<'tcx
> {
1810 if let Some(did
) = did
.as_local() {
1811 self.hir().attrs(self.hir().local_def_id_to_hir_id(did
))
1813 self.item_attrs(did
)
1817 /// Determines whether an item is annotated with an attribute.
1818 pub fn has_attr(self, did
: DefId
, attr
: Symbol
) -> bool
{
1819 self.sess
.contains_name(&self.get_attrs(did
), attr
)
1822 /// Returns `true` if this is an `auto trait`.
1823 pub fn trait_is_auto(self, trait_def_id
: DefId
) -> bool
{
1824 self.trait_def(trait_def_id
).has_auto_impl
1827 /// Returns layout of a generator. Layout might be unavailable if the
1828 /// generator is tainted by errors.
1829 pub fn generator_layout(self, def_id
: DefId
) -> Option
<&'tcx GeneratorLayout
<'tcx
>> {
1830 self.optimized_mir(def_id
).generator_layout()
1833 /// Given the `DefId` of an impl, returns the `DefId` of the trait it implements.
1834 /// If it implements no trait, returns `None`.
1835 pub fn trait_id_of_impl(self, def_id
: DefId
) -> Option
<DefId
> {
1836 self.impl_trait_ref(def_id
).map(|tr
| tr
.def_id
)
1839 /// If the given defid describes a method belonging to an impl, returns the
1840 /// `DefId` of the impl that the method belongs to; otherwise, returns `None`.
1841 pub fn impl_of_method(self, def_id
: DefId
) -> Option
<DefId
> {
1842 self.opt_associated_item(def_id
).and_then(|trait_item
| match trait_item
.container
{
1843 TraitContainer(_
) => None
,
1844 ImplContainer(def_id
) => Some(def_id
),
1848 /// Looks up the span of `impl_did` if the impl is local; otherwise returns `Err`
1849 /// with the name of the crate containing the impl.
1850 pub fn span_of_impl(self, impl_did
: DefId
) -> Result
<Span
, Symbol
> {
1851 if let Some(impl_did
) = impl_did
.as_local() {
1852 let hir_id
= self.hir().local_def_id_to_hir_id(impl_did
);
1853 Ok(self.hir().span(hir_id
))
1855 Err(self.crate_name(impl_did
.krate
))
1859 /// Hygienically compares a use-site name (`use_name`) for a field or an associated item with
1860 /// its supposed definition name (`def_name`). The method also needs `DefId` of the supposed
1861 /// definition's parent/scope to perform comparison.
1862 pub fn hygienic_eq(self, use_name
: Ident
, def_name
: Ident
, def_parent_def_id
: DefId
) -> bool
{
1863 // We could use `Ident::eq` here, but we deliberately don't. The name
1864 // comparison fails frequently, and we want to avoid the expensive
1865 // `normalize_to_macros_2_0()` calls required for the span comparison whenever possible.
1866 use_name
.name
== def_name
.name
1870 .hygienic_eq(def_name
.span
.ctxt(), self.expn_that_defined(def_parent_def_id
))
1873 pub fn adjust_ident(self, mut ident
: Ident
, scope
: DefId
) -> Ident
{
1874 ident
.span
.normalize_to_macros_2_0_and_adjust(self.expn_that_defined(scope
));
1878 pub fn adjust_ident_and_get_scope(
1883 ) -> (Ident
, DefId
) {
1885 match ident
.span
.normalize_to_macros_2_0_and_adjust(self.expn_that_defined(scope
)) {
1886 Some(actual_expansion
) => {
1887 self.hir().definitions().parent_module_of_macro_def(actual_expansion
)
1889 None
=> self.parent_module(block
).to_def_id(),
1894 pub fn is_object_safe(self, key
: DefId
) -> bool
{
1895 self.object_safety_violations(key
).is_empty()
1899 /// Yields the parent function's `DefId` if `def_id` is an `impl Trait` definition.
1900 pub fn is_impl_trait_defn(tcx
: TyCtxt
<'_
>, def_id
: DefId
) -> Option
<DefId
> {
1901 if let Some(def_id
) = def_id
.as_local() {
1902 if let Node
::Item(item
) = tcx
.hir().get(tcx
.hir().local_def_id_to_hir_id(def_id
)) {
1903 if let hir
::ItemKind
::OpaqueTy(ref opaque_ty
) = item
.kind
{
1904 return opaque_ty
.impl_trait_fn
;
1911 pub fn int_ty(ity
: ast
::IntTy
) -> IntTy
{
1913 ast
::IntTy
::Isize
=> IntTy
::Isize
,
1914 ast
::IntTy
::I8
=> IntTy
::I8
,
1915 ast
::IntTy
::I16
=> IntTy
::I16
,
1916 ast
::IntTy
::I32
=> IntTy
::I32
,
1917 ast
::IntTy
::I64
=> IntTy
::I64
,
1918 ast
::IntTy
::I128
=> IntTy
::I128
,
1922 pub fn uint_ty(uty
: ast
::UintTy
) -> UintTy
{
1924 ast
::UintTy
::Usize
=> UintTy
::Usize
,
1925 ast
::UintTy
::U8
=> UintTy
::U8
,
1926 ast
::UintTy
::U16
=> UintTy
::U16
,
1927 ast
::UintTy
::U32
=> UintTy
::U32
,
1928 ast
::UintTy
::U64
=> UintTy
::U64
,
1929 ast
::UintTy
::U128
=> UintTy
::U128
,
1933 pub fn float_ty(fty
: ast
::FloatTy
) -> FloatTy
{
1935 ast
::FloatTy
::F32
=> FloatTy
::F32
,
1936 ast
::FloatTy
::F64
=> FloatTy
::F64
,
1940 pub fn ast_int_ty(ity
: IntTy
) -> ast
::IntTy
{
1942 IntTy
::Isize
=> ast
::IntTy
::Isize
,
1943 IntTy
::I8
=> ast
::IntTy
::I8
,
1944 IntTy
::I16
=> ast
::IntTy
::I16
,
1945 IntTy
::I32
=> ast
::IntTy
::I32
,
1946 IntTy
::I64
=> ast
::IntTy
::I64
,
1947 IntTy
::I128
=> ast
::IntTy
::I128
,
1951 pub fn ast_uint_ty(uty
: UintTy
) -> ast
::UintTy
{
1953 UintTy
::Usize
=> ast
::UintTy
::Usize
,
1954 UintTy
::U8
=> ast
::UintTy
::U8
,
1955 UintTy
::U16
=> ast
::UintTy
::U16
,
1956 UintTy
::U32
=> ast
::UintTy
::U32
,
1957 UintTy
::U64
=> ast
::UintTy
::U64
,
1958 UintTy
::U128
=> ast
::UintTy
::U128
,
1962 pub fn provide(providers
: &mut ty
::query
::Providers
) {
1963 context
::provide(providers
);
1964 erase_regions
::provide(providers
);
1965 layout
::provide(providers
);
1966 util
::provide(providers
);
1967 print
::provide(providers
);
1968 super::util
::bug
::provide(providers
);
1969 *providers
= ty
::query
::Providers
{
1970 trait_impls_of
: trait_def
::trait_impls_of_provider
,
1971 type_uninhabited_from
: inhabitedness
::type_uninhabited_from
,
1972 const_param_default
: consts
::const_param_default
,
1977 /// A map for the local crate mapping each type to a vector of its
1978 /// inherent impls. This is not meant to be used outside of coherence;
1979 /// rather, you should request the vector for a specific type via
1980 /// `tcx.inherent_impls(def_id)` so as to minimize your dependencies
1981 /// (constructing this map requires touching the entire crate).
1982 #[derive(Clone, Debug, Default, HashStable)]
1983 pub struct CrateInherentImpls
{
1984 pub inherent_impls
: LocalDefIdMap
<Vec
<DefId
>>,
1987 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, TyEncodable, HashStable)]
1988 pub struct SymbolName
<'tcx
> {
1989 /// `&str` gives a consistent ordering, which ensures reproducible builds.
1990 pub name
: &'tcx
str,
1993 impl<'tcx
> SymbolName
<'tcx
> {
1994 pub fn new(tcx
: TyCtxt
<'tcx
>, name
: &str) -> SymbolName
<'tcx
> {
1996 name
: unsafe { str::from_utf8_unchecked(tcx.arena.alloc_slice(name.as_bytes())) }
,
2001 impl<'tcx
> fmt
::Display
for SymbolName
<'tcx
> {
2002 fn fmt(&self, fmt
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
2003 fmt
::Display
::fmt(&self.name
, fmt
)
2007 impl<'tcx
> fmt
::Debug
for SymbolName
<'tcx
> {
2008 fn fmt(&self, fmt
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
2009 fmt
::Display
::fmt(&self.name
, fmt
)