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}
;
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
::collections
::BTreeMap
;
48 use std
::hash
::{Hash, Hasher}
;
49 use std
::ops
::ControlFlow
;
50 use std
::{fmt, ptr, str}
;
52 pub use crate::ty
::diagnostics
::*;
53 pub use rustc_type_ir
::InferTy
::*;
54 pub use rustc_type_ir
::*;
56 pub use self::binding
::BindingMode
;
57 pub use self::binding
::BindingMode
::*;
58 pub use self::closure
::{
59 is_ancestor_or_same_capture
, place_to_string_for_capture
, BorrowKind
, CaptureInfo
,
60 CapturedPlace
, ClosureKind
, MinCaptureInformationMap
, MinCaptureList
,
61 RootVariableMinCaptureList
, UpvarBorrow
, UpvarCapture
, UpvarCaptureMap
, UpvarId
, UpvarListMap
,
62 UpvarPath
, CAPTURE_STRUCT_LOCAL
,
64 pub use self::consts
::{Const, ConstInt, ConstKind, InferConst, ScalarInt, Unevaluated, ValTree}
;
65 pub use self::context
::{
66 tls
, CanonicalUserType
, CanonicalUserTypeAnnotation
, CanonicalUserTypeAnnotations
,
67 CtxtInterners
, DelaySpanBugEmitted
, FreeRegionInfo
, GeneratorInteriorTypeCause
, GlobalCtxt
,
68 Lift
, OnDiskCache
, TyCtxt
, TypeckResults
, UserType
, UserTypeAnnotationIndex
,
70 pub use self::instance
::{Instance, InstanceDef}
;
71 pub use self::list
::List
;
72 pub use self::sty
::BoundRegionKind
::*;
73 pub use self::sty
::RegionKind
::*;
74 pub use self::sty
::TyKind
::*;
76 Binder
, BoundRegion
, BoundRegionKind
, BoundTy
, BoundTyKind
, BoundVar
, BoundVariableKind
,
77 CanonicalPolyFnSig
, ClosureSubsts
, ClosureSubstsParts
, ConstVid
, EarlyBoundRegion
,
78 ExistentialPredicate
, ExistentialProjection
, ExistentialTraitRef
, FnSig
, FreeRegion
, GenSig
,
79 GeneratorSubsts
, GeneratorSubstsParts
, ParamConst
, ParamTy
, PolyExistentialProjection
,
80 PolyExistentialTraitRef
, PolyFnSig
, PolyGenSig
, PolyTraitRef
, ProjectionTy
, Region
, RegionKind
,
81 RegionVid
, TraitRef
, TyKind
, TypeAndMut
, UpvarSubsts
, VarianceDiagInfo
, VarianceDiagMutKind
,
83 pub use self::trait_def
::TraitDef
;
94 pub mod inhabitedness
;
96 pub mod normalize_erasing_regions
;
117 mod structural_impls
;
123 pub struct ResolverOutputs
{
124 pub definitions
: rustc_hir
::definitions
::Definitions
,
125 pub cstore
: Box
<CrateStoreDyn
>,
126 pub visibilities
: FxHashMap
<LocalDefId
, Visibility
>,
127 pub extern_crate_map
: FxHashMap
<LocalDefId
, CrateNum
>,
128 pub maybe_unused_trait_imports
: FxHashSet
<LocalDefId
>,
129 pub maybe_unused_extern_crates
: Vec
<(LocalDefId
, Span
)>,
130 pub export_map
: ExportMap
<LocalDefId
>,
131 pub glob_map
: FxHashMap
<LocalDefId
, FxHashSet
<Symbol
>>,
132 /// Extern prelude entries. The value is `true` if the entry was introduced
133 /// via `extern crate` item and not `--extern` option or compiler built-in.
134 pub extern_prelude
: FxHashMap
<Symbol
, bool
>,
135 pub main_def
: Option
<MainDefinition
>,
136 pub trait_impls
: BTreeMap
<DefId
, Vec
<LocalDefId
>>,
137 /// A list of proc macro LocalDefIds, written out in the order in which
138 /// they are declared in the static array generated by proc_macro_harness.
139 pub proc_macros
: Vec
<LocalDefId
>,
142 #[derive(Clone, Copy, Debug)]
143 pub struct MainDefinition
{
144 pub res
: Res
<ast
::NodeId
>,
149 impl MainDefinition
{
150 pub fn opt_fn_def_id(self) -> Option
<DefId
> {
151 if let Res
::Def(DefKind
::Fn
, def_id
) = self.res { Some(def_id) }
else { None }
155 /// The "header" of an impl is everything outside the body: a Self type, a trait
156 /// ref (in the case of a trait impl), and a set of predicates (from the
157 /// bounds / where-clauses).
158 #[derive(Clone, Debug, TypeFoldable)]
159 pub struct ImplHeader
<'tcx
> {
160 pub impl_def_id
: DefId
,
161 pub self_ty
: Ty
<'tcx
>,
162 pub trait_ref
: Option
<TraitRef
<'tcx
>>,
163 pub predicates
: Vec
<Predicate
<'tcx
>>,
166 #[derive(Copy, Clone, PartialEq, TyEncodable, TyDecodable, HashStable, Debug)]
167 pub enum ImplPolarity
{
168 /// `impl Trait for Type`
170 /// `impl !Trait for Type`
172 /// `#[rustc_reservation_impl] impl Trait for Type`
174 /// This is a "stability hack", not a real Rust feature.
175 /// See #64631 for details.
179 #[derive(Clone, Debug, PartialEq, Eq, Copy, Hash, TyEncodable, TyDecodable, HashStable)]
180 pub enum Visibility
{
181 /// Visible everywhere (including in other crates).
183 /// Visible only in the given crate-local module.
185 /// Not visible anywhere in the local crate. This is the visibility of private external items.
189 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable, TyEncodable, TyDecodable)]
190 pub enum BoundConstness
{
193 /// `T: ~const Trait`
195 /// Requires resolving to const only when we are in a const context.
199 impl fmt
::Display
for BoundConstness
{
200 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
202 Self::NotConst
=> f
.write_str("normal"),
203 Self::ConstIfConst
=> f
.write_str("`~const`"),
220 pub struct ClosureSizeProfileData
<'tcx
> {
221 /// Tuple containing the types of closure captures before the feature `capture_disjoint_fields`
222 pub before_feature_tys
: Ty
<'tcx
>,
223 /// Tuple containing the types of closure captures after the feature `capture_disjoint_fields`
224 pub after_feature_tys
: Ty
<'tcx
>,
227 pub trait DefIdTree
: Copy
{
228 fn parent(self, id
: DefId
) -> Option
<DefId
>;
230 fn is_descendant_of(self, mut descendant
: DefId
, ancestor
: DefId
) -> bool
{
231 if descendant
.krate
!= ancestor
.krate
{
235 while descendant
!= ancestor
{
236 match self.parent(descendant
) {
237 Some(parent
) => descendant
= parent
,
238 None
=> return false,
245 impl<'tcx
> DefIdTree
for TyCtxt
<'tcx
> {
246 fn parent(self, id
: DefId
) -> Option
<DefId
> {
247 self.def_key(id
).parent
.map(|index
| DefId { index, ..id }
)
252 pub fn from_hir(visibility
: &hir
::Visibility
<'_
>, id
: hir
::HirId
, tcx
: TyCtxt
<'_
>) -> Self {
253 match visibility
.node
{
254 hir
::VisibilityKind
::Public
=> Visibility
::Public
,
255 hir
::VisibilityKind
::Crate(_
) => Visibility
::Restricted(DefId
::local(CRATE_DEF_INDEX
)),
256 hir
::VisibilityKind
::Restricted { ref path, .. }
=> match path
.res
{
257 // If there is no resolution, `resolve` will have already reported an error, so
258 // assume that the visibility is public to avoid reporting more privacy errors.
259 Res
::Err
=> Visibility
::Public
,
260 def
=> Visibility
::Restricted(def
.def_id()),
262 hir
::VisibilityKind
::Inherited
=> {
263 Visibility
::Restricted(tcx
.parent_module(id
).to_def_id())
268 /// Returns `true` if an item with this visibility is accessible from the given block.
269 pub fn is_accessible_from
<T
: DefIdTree
>(self, module
: DefId
, tree
: T
) -> bool
{
270 let restriction
= match self {
271 // Public items are visible everywhere.
272 Visibility
::Public
=> return true,
273 // Private items from other crates are visible nowhere.
274 Visibility
::Invisible
=> return false,
275 // Restricted items are visible in an arbitrary local module.
276 Visibility
::Restricted(other
) if other
.krate
!= module
.krate
=> return false,
277 Visibility
::Restricted(module
) => module
,
280 tree
.is_descendant_of(module
, restriction
)
283 /// Returns `true` if this visibility is at least as accessible as the given visibility
284 pub fn is_at_least
<T
: DefIdTree
>(self, vis
: Visibility
, tree
: T
) -> bool
{
285 let vis_restriction
= match vis
{
286 Visibility
::Public
=> return self == Visibility
::Public
,
287 Visibility
::Invisible
=> return true,
288 Visibility
::Restricted(module
) => module
,
291 self.is_accessible_from(vis_restriction
, tree
)
294 // Returns `true` if this item is visible anywhere in the local crate.
295 pub fn is_visible_locally(self) -> bool
{
297 Visibility
::Public
=> true,
298 Visibility
::Restricted(def_id
) => def_id
.is_local(),
299 Visibility
::Invisible
=> false,
304 /// The crate variances map is computed during typeck and contains the
305 /// variance of every item in the local crate. You should not use it
306 /// directly, because to do so will make your pass dependent on the
307 /// HIR of every item in the local crate. Instead, use
308 /// `tcx.variances_of()` to get the variance for a *particular*
310 #[derive(HashStable, Debug)]
311 pub struct CrateVariancesMap
<'tcx
> {
312 /// For each item with generics, maps to a vector of the variance
313 /// of its generics. If an item has no generics, it will have no
315 pub variances
: FxHashMap
<DefId
, &'tcx
[ty
::Variance
]>,
318 // Contains information needed to resolve types and (in the future) look up
319 // the types of AST nodes.
320 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
321 pub struct CReaderCacheKey
{
322 pub cnum
: Option
<CrateNum
>,
326 #[allow(rustc::usage_of_ty_tykind)]
327 pub struct TyS
<'tcx
> {
328 /// This field shouldn't be used directly and may be removed in the future.
329 /// Use `TyS::kind()` instead.
331 /// This field shouldn't be used directly and may be removed in the future.
332 /// Use `TyS::flags()` instead.
335 /// This is a kind of confusing thing: it stores the smallest
338 /// (a) the binder itself captures nothing but
339 /// (b) all the late-bound things within the type are captured
340 /// by some sub-binder.
342 /// So, for a type without any late-bound things, like `u32`, this
343 /// will be *innermost*, because that is the innermost binder that
344 /// captures nothing. But for a type `&'D u32`, where `'D` is a
345 /// late-bound region with De Bruijn index `D`, this would be `D + 1`
346 /// -- the binder itself does not capture `D`, but `D` is captured
347 /// by an inner binder.
349 /// We call this concept an "exclusive" binder `D` because all
350 /// De Bruijn indices within the type are contained within `0..D`
352 outer_exclusive_binder
: ty
::DebruijnIndex
,
355 impl<'tcx
> TyS
<'tcx
> {
356 /// A constructor used only for internal testing.
357 #[allow(rustc::usage_of_ty_tykind)]
358 pub fn make_for_test(
361 outer_exclusive_binder
: ty
::DebruijnIndex
,
363 TyS { kind, flags, outer_exclusive_binder }
367 // `TyS` is used a lot. Make sure it doesn't unintentionally get bigger.
368 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
369 static_assert_size
!(TyS
<'_
>, 40);
371 impl<'tcx
> Ord
for TyS
<'tcx
> {
372 fn cmp(&self, other
: &TyS
<'tcx
>) -> Ordering
{
373 self.kind().cmp(other
.kind())
377 impl<'tcx
> PartialOrd
for TyS
<'tcx
> {
378 fn partial_cmp(&self, other
: &TyS
<'tcx
>) -> Option
<Ordering
> {
379 Some(self.kind().cmp(other
.kind()))
383 impl<'tcx
> PartialEq
for TyS
<'tcx
> {
385 fn eq(&self, other
: &TyS
<'tcx
>) -> bool
{
389 impl<'tcx
> Eq
for TyS
<'tcx
> {}
391 impl<'tcx
> Hash
for TyS
<'tcx
> {
392 fn hash
<H
: Hasher
>(&self, s
: &mut H
) {
393 (self as *const TyS
<'_
>).hash(s
)
397 impl<'a
, 'tcx
> HashStable
<StableHashingContext
<'a
>> for TyS
<'tcx
> {
398 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
402 // The other fields just provide fast access to information that is
403 // also contained in `kind`, so no need to hash them.
406 outer_exclusive_binder
: _
,
409 kind
.hash_stable(hcx
, hasher
);
413 #[rustc_diagnostic_item = "Ty"]
414 pub type Ty
<'tcx
> = &'tcx TyS
<'tcx
>;
416 impl ty
::EarlyBoundRegion
{
417 /// Does this early bound region have a name? Early bound regions normally
418 /// always have names except when using anonymous lifetimes (`'_`).
419 pub fn has_name(&self) -> bool
{
420 self.name
!= kw
::UnderscoreLifetime
425 crate struct PredicateInner
<'tcx
> {
426 kind
: Binder
<'tcx
, PredicateKind
<'tcx
>>,
428 /// See the comment for the corresponding field of [TyS].
429 outer_exclusive_binder
: ty
::DebruijnIndex
,
432 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
433 static_assert_size
!(PredicateInner
<'_
>, 48);
435 #[derive(Clone, Copy, Lift)]
436 pub struct Predicate
<'tcx
> {
437 inner
: &'tcx PredicateInner
<'tcx
>,
440 impl<'tcx
> PartialEq
for Predicate
<'tcx
> {
441 fn eq(&self, other
: &Self) -> bool
{
442 // `self.kind` is always interned.
443 ptr
::eq(self.inner
, other
.inner
)
447 impl Hash
for Predicate
<'_
> {
448 fn hash
<H
: Hasher
>(&self, s
: &mut H
) {
449 (self.inner
as *const PredicateInner
<'_
>).hash(s
)
453 impl<'tcx
> Eq
for Predicate
<'tcx
> {}
455 impl<'tcx
> Predicate
<'tcx
> {
456 /// Gets the inner `Binder<'tcx, PredicateKind<'tcx>>`.
458 pub fn kind(self) -> Binder
<'tcx
, PredicateKind
<'tcx
>> {
463 impl<'a
, 'tcx
> HashStable
<StableHashingContext
<'a
>> for Predicate
<'tcx
> {
464 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
468 // The other fields just provide fast access to information that is
469 // also contained in `kind`, so no need to hash them.
471 outer_exclusive_binder
: _
,
474 kind
.hash_stable(hcx
, hasher
);
478 #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)]
479 #[derive(HashStable, TypeFoldable)]
480 pub enum PredicateKind
<'tcx
> {
481 /// Corresponds to `where Foo: Bar<A, B, C>`. `Foo` here would be
482 /// the `Self` type of the trait reference and `A`, `B`, and `C`
483 /// would be the type parameters.
484 Trait(TraitPredicate
<'tcx
>),
487 RegionOutlives(RegionOutlivesPredicate
<'tcx
>),
490 TypeOutlives(TypeOutlivesPredicate
<'tcx
>),
492 /// `where <T as TraitRef>::Name == X`, approximately.
493 /// See the `ProjectionPredicate` struct for details.
494 Projection(ProjectionPredicate
<'tcx
>),
496 /// No syntax: `T` well-formed.
497 WellFormed(GenericArg
<'tcx
>),
499 /// Trait must be object-safe.
502 /// No direct syntax. May be thought of as `where T: FnFoo<...>`
503 /// for some substitutions `...` and `T` being a closure type.
504 /// Satisfied (or refuted) once we know the closure's kind.
505 ClosureKind(DefId
, SubstsRef
<'tcx
>, ClosureKind
),
509 /// This obligation is created most often when we have two
510 /// unresolved type variables and hence don't have enough
511 /// information to process the subtyping obligation yet.
512 Subtype(SubtypePredicate
<'tcx
>),
514 /// `T1` coerced to `T2`
516 /// Like a subtyping obligation, this is created most often
517 /// when we have two unresolved type variables and hence
518 /// don't have enough information to process the coercion
519 /// obligation yet. At the moment, we actually process coercions
520 /// very much like subtyping and don't handle the full coercion
522 Coerce(CoercePredicate
<'tcx
>),
524 /// Constant initializer must evaluate successfully.
525 ConstEvaluatable(ty
::Unevaluated
<'tcx
, ()>),
527 /// Constants must be equal. The first component is the const that is expected.
528 ConstEquate(&'tcx Const
<'tcx
>, &'tcx Const
<'tcx
>),
530 /// Represents a type found in the environment that we can use for implied bounds.
532 /// Only used for Chalk.
533 TypeWellFormedFromEnv(Ty
<'tcx
>),
536 /// The crate outlives map is computed during typeck and contains the
537 /// outlives of every item in the local crate. You should not use it
538 /// directly, because to do so will make your pass dependent on the
539 /// HIR of every item in the local crate. Instead, use
540 /// `tcx.inferred_outlives_of()` to get the outlives for a *particular*
542 #[derive(HashStable, Debug)]
543 pub struct CratePredicatesMap
<'tcx
> {
544 /// For each struct with outlive bounds, maps to a vector of the
545 /// predicate of its outlive bounds. If an item has no outlives
546 /// bounds, it will have no entry.
547 pub predicates
: FxHashMap
<DefId
, &'tcx
[(Predicate
<'tcx
>, Span
)]>,
550 impl<'tcx
> Predicate
<'tcx
> {
551 /// Performs a substitution suitable for going from a
552 /// poly-trait-ref to supertraits that must hold if that
553 /// poly-trait-ref holds. This is slightly different from a normal
554 /// substitution in terms of what happens with bound regions. See
555 /// lengthy comment below for details.
556 pub fn subst_supertrait(
559 trait_ref
: &ty
::PolyTraitRef
<'tcx
>,
560 ) -> Predicate
<'tcx
> {
561 // The interaction between HRTB and supertraits is not entirely
562 // obvious. Let me walk you (and myself) through an example.
564 // Let's start with an easy case. Consider two traits:
566 // trait Foo<'a>: Bar<'a,'a> { }
567 // trait Bar<'b,'c> { }
569 // Now, if we have a trait reference `for<'x> T: Foo<'x>`, then
570 // we can deduce that `for<'x> T: Bar<'x,'x>`. Basically, if we
571 // knew that `Foo<'x>` (for any 'x) then we also know that
572 // `Bar<'x,'x>` (for any 'x). This more-or-less falls out from
573 // normal substitution.
575 // In terms of why this is sound, the idea is that whenever there
576 // is an impl of `T:Foo<'a>`, it must show that `T:Bar<'a,'a>`
577 // holds. So if there is an impl of `T:Foo<'a>` that applies to
578 // all `'a`, then we must know that `T:Bar<'a,'a>` holds for all
581 // Another example to be careful of is this:
583 // trait Foo1<'a>: for<'b> Bar1<'a,'b> { }
584 // trait Bar1<'b,'c> { }
586 // Here, if we have `for<'x> T: Foo1<'x>`, then what do we know?
587 // The answer is that we know `for<'x,'b> T: Bar1<'x,'b>`. The
588 // reason is similar to the previous example: any impl of
589 // `T:Foo1<'x>` must show that `for<'b> T: Bar1<'x, 'b>`. So
590 // basically we would want to collapse the bound lifetimes from
591 // the input (`trait_ref`) and the supertraits.
593 // To achieve this in practice is fairly straightforward. Let's
594 // consider the more complicated scenario:
596 // - We start out with `for<'x> T: Foo1<'x>`. In this case, `'x`
597 // has a De Bruijn index of 1. We want to produce `for<'x,'b> T: Bar1<'x,'b>`,
598 // where both `'x` and `'b` would have a DB index of 1.
599 // The substitution from the input trait-ref is therefore going to be
600 // `'a => 'x` (where `'x` has a DB index of 1).
601 // - The super-trait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an
602 // early-bound parameter and `'b' is a late-bound parameter with a
604 // - If we replace `'a` with `'x` from the input, it too will have
605 // a DB index of 1, and thus we'll have `for<'x,'b> Bar1<'x,'b>`
606 // just as we wanted.
608 // There is only one catch. If we just apply the substitution `'a
609 // => 'x` to `for<'b> Bar1<'a,'b>`, the substitution code will
610 // adjust the DB index because we substituting into a binder (it
611 // tries to be so smart...) resulting in `for<'x> for<'b>
612 // Bar1<'x,'b>` (we have no syntax for this, so use your
613 // imagination). Basically the 'x will have DB index of 2 and 'b
614 // will have DB index of 1. Not quite what we want. So we apply
615 // the substitution to the *contents* of the trait reference,
616 // rather than the trait reference itself (put another way, the
617 // substitution code expects equal binding levels in the values
618 // from the substitution and the value being substituted into, and
619 // this trick achieves that).
621 // Working through the second example:
622 // trait_ref: for<'x> T: Foo1<'^0.0>; substs: [T, '^0.0]
623 // predicate: for<'b> Self: Bar1<'a, '^0.0>; substs: [Self, 'a, '^0.0]
624 // We want to end up with:
625 // for<'x, 'b> T: Bar1<'^0.0, '^0.1>
627 // 1) We must shift all bound vars in predicate by the length
628 // of trait ref's bound vars. So, we would end up with predicate like
629 // Self: Bar1<'a, '^0.1>
630 // 2) We can then apply the trait substs to this, ending up with
631 // T: Bar1<'^0.0, '^0.1>
632 // 3) Finally, to create the final bound vars, we concatenate the bound
633 // vars of the trait ref with those of the predicate:
635 let bound_pred
= self.kind();
636 let pred_bound_vars
= bound_pred
.bound_vars();
637 let trait_bound_vars
= trait_ref
.bound_vars();
638 // 1) Self: Bar1<'a, '^0.0> -> Self: Bar1<'a, '^0.1>
640 tcx
.shift_bound_var_indices(trait_bound_vars
.len(), bound_pred
.skip_binder());
641 // 2) Self: Bar1<'a, '^0.1> -> T: Bar1<'^0.0, '^0.1>
642 let new
= shifted_pred
.subst(tcx
, trait_ref
.skip_binder().substs
);
643 // 3) ['x] + ['b] -> ['x, 'b]
645 tcx
.mk_bound_variable_kinds(trait_bound_vars
.iter().chain(pred_bound_vars
));
646 tcx
.reuse_or_mk_predicate(self, ty
::Binder
::bind_with_vars(new
, bound_vars
))
650 #[derive(Clone, Copy, PartialEq, Eq, Hash, TyEncodable, TyDecodable)]
651 #[derive(HashStable, TypeFoldable)]
652 pub struct TraitPredicate
<'tcx
> {
653 pub trait_ref
: TraitRef
<'tcx
>,
655 pub constness
: BoundConstness
,
658 pub type PolyTraitPredicate
<'tcx
> = ty
::Binder
<'tcx
, TraitPredicate
<'tcx
>>;
660 impl<'tcx
> TraitPredicate
<'tcx
> {
661 pub fn def_id(self) -> DefId
{
662 self.trait_ref
.def_id
665 pub fn self_ty(self) -> Ty
<'tcx
> {
666 self.trait_ref
.self_ty()
670 impl<'tcx
> PolyTraitPredicate
<'tcx
> {
671 pub fn def_id(self) -> DefId
{
672 // Ok to skip binder since trait `DefId` does not care about regions.
673 self.skip_binder().def_id()
676 pub fn self_ty(self) -> ty
::Binder
<'tcx
, Ty
<'tcx
>> {
677 self.map_bound(|trait_ref
| trait_ref
.self_ty())
681 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, TyEncodable, TyDecodable)]
682 #[derive(HashStable, TypeFoldable)]
683 pub struct OutlivesPredicate
<A
, B
>(pub A
, pub B
); // `A: B`
684 pub type RegionOutlivesPredicate
<'tcx
> = OutlivesPredicate
<ty
::Region
<'tcx
>, ty
::Region
<'tcx
>>;
685 pub type TypeOutlivesPredicate
<'tcx
> = OutlivesPredicate
<Ty
<'tcx
>, ty
::Region
<'tcx
>>;
686 pub type PolyRegionOutlivesPredicate
<'tcx
> = ty
::Binder
<'tcx
, RegionOutlivesPredicate
<'tcx
>>;
687 pub type PolyTypeOutlivesPredicate
<'tcx
> = ty
::Binder
<'tcx
, TypeOutlivesPredicate
<'tcx
>>;
689 /// Encodes that `a` must be a subtype of `b`. The `a_is_expected` flag indicates
690 /// whether the `a` type is the type that we should label as "expected" when
691 /// presenting user diagnostics.
692 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, TyEncodable, TyDecodable)]
693 #[derive(HashStable, TypeFoldable)]
694 pub struct SubtypePredicate
<'tcx
> {
695 pub a_is_expected
: bool
,
699 pub type PolySubtypePredicate
<'tcx
> = ty
::Binder
<'tcx
, SubtypePredicate
<'tcx
>>;
701 /// Encodes that we have to coerce *from* the `a` type to the `b` type.
702 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, TyEncodable, TyDecodable)]
703 #[derive(HashStable, TypeFoldable)]
704 pub struct CoercePredicate
<'tcx
> {
708 pub type PolyCoercePredicate
<'tcx
> = ty
::Binder
<'tcx
, CoercePredicate
<'tcx
>>;
710 /// This kind of predicate has no *direct* correspondent in the
711 /// syntax, but it roughly corresponds to the syntactic forms:
713 /// 1. `T: TraitRef<..., Item = Type>`
714 /// 2. `<T as TraitRef<...>>::Item == Type` (NYI)
716 /// In particular, form #1 is "desugared" to the combination of a
717 /// normal trait predicate (`T: TraitRef<...>`) and one of these
718 /// predicates. Form #2 is a broader form in that it also permits
719 /// equality between arbitrary types. Processing an instance of
720 /// Form #2 eventually yields one of these `ProjectionPredicate`
721 /// instances to normalize the LHS.
722 #[derive(Copy, Clone, PartialEq, Eq, Hash, TyEncodable, TyDecodable)]
723 #[derive(HashStable, TypeFoldable)]
724 pub struct ProjectionPredicate
<'tcx
> {
725 pub projection_ty
: ProjectionTy
<'tcx
>,
729 pub type PolyProjectionPredicate
<'tcx
> = Binder
<'tcx
, ProjectionPredicate
<'tcx
>>;
731 impl<'tcx
> PolyProjectionPredicate
<'tcx
> {
732 /// Returns the `DefId` of the trait of the associated item being projected.
734 pub fn trait_def_id(&self, tcx
: TyCtxt
<'tcx
>) -> DefId
{
735 self.skip_binder().projection_ty
.trait_def_id(tcx
)
738 /// Get the [PolyTraitRef] required for this projection to be well formed.
739 /// Note that for generic associated types the predicates of the associated
740 /// type also need to be checked.
742 pub fn required_poly_trait_ref(&self, tcx
: TyCtxt
<'tcx
>) -> PolyTraitRef
<'tcx
> {
743 // Note: unlike with `TraitRef::to_poly_trait_ref()`,
744 // `self.0.trait_ref` is permitted to have escaping regions.
745 // This is because here `self` has a `Binder` and so does our
746 // return value, so we are preserving the number of binding
748 self.map_bound(|predicate
| predicate
.projection_ty
.trait_ref(tcx
))
751 pub fn ty(&self) -> Binder
<'tcx
, Ty
<'tcx
>> {
752 self.map_bound(|predicate
| predicate
.ty
)
755 /// The `DefId` of the `TraitItem` for the associated type.
757 /// Note that this is not the `DefId` of the `TraitRef` containing this
758 /// associated type, which is in `tcx.associated_item(projection_def_id()).container`.
759 pub fn projection_def_id(&self) -> DefId
{
760 // Ok to skip binder since trait `DefId` does not care about regions.
761 self.skip_binder().projection_ty
.item_def_id
765 pub trait ToPolyTraitRef
<'tcx
> {
766 fn to_poly_trait_ref(&self) -> PolyTraitRef
<'tcx
>;
769 impl<'tcx
> ToPolyTraitRef
<'tcx
> for TraitRef
<'tcx
> {
770 fn to_poly_trait_ref(&self) -> PolyTraitRef
<'tcx
> {
771 ty
::Binder
::dummy(*self)
775 impl<'tcx
> ToPolyTraitRef
<'tcx
> for PolyTraitPredicate
<'tcx
> {
776 fn to_poly_trait_ref(&self) -> PolyTraitRef
<'tcx
> {
777 self.map_bound_ref(|trait_pred
| trait_pred
.trait_ref
)
781 pub trait ToPredicate
<'tcx
> {
782 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
>;
785 impl ToPredicate
<'tcx
> for Binder
<'tcx
, PredicateKind
<'tcx
>> {
787 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
788 tcx
.mk_predicate(self)
792 impl ToPredicate
<'tcx
> for PredicateKind
<'tcx
> {
794 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
795 tcx
.mk_predicate(Binder
::dummy(self))
799 impl<'tcx
> ToPredicate
<'tcx
> for ConstnessAnd
<TraitRef
<'tcx
>> {
800 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
801 PredicateKind
::Trait(ty
::TraitPredicate
{
802 trait_ref
: self.value
,
803 constness
: self.constness
,
809 impl<'tcx
> ToPredicate
<'tcx
> for ConstnessAnd
<PolyTraitRef
<'tcx
>> {
810 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
812 .map_bound(|trait_ref
| {
813 PredicateKind
::Trait(ty
::TraitPredicate { trait_ref, constness: self.constness }
)
819 impl<'tcx
> ToPredicate
<'tcx
> for PolyTraitPredicate
<'tcx
> {
820 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
821 self.map_bound(PredicateKind
::Trait
).to_predicate(tcx
)
825 impl<'tcx
> ToPredicate
<'tcx
> for PolyRegionOutlivesPredicate
<'tcx
> {
826 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
827 self.map_bound(PredicateKind
::RegionOutlives
).to_predicate(tcx
)
831 impl<'tcx
> ToPredicate
<'tcx
> for PolyTypeOutlivesPredicate
<'tcx
> {
832 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
833 self.map_bound(PredicateKind
::TypeOutlives
).to_predicate(tcx
)
837 impl<'tcx
> ToPredicate
<'tcx
> for PolyProjectionPredicate
<'tcx
> {
838 fn to_predicate(self, tcx
: TyCtxt
<'tcx
>) -> Predicate
<'tcx
> {
839 self.map_bound(PredicateKind
::Projection
).to_predicate(tcx
)
843 impl<'tcx
> Predicate
<'tcx
> {
844 pub fn to_opt_poly_trait_ref(self) -> Option
<ConstnessAnd
<PolyTraitRef
<'tcx
>>> {
845 let predicate
= self.kind();
846 match predicate
.skip_binder() {
847 PredicateKind
::Trait(t
) => {
848 Some(ConstnessAnd { constness: t.constness, value: predicate.rebind(t.trait_ref) }
)
850 PredicateKind
::Projection(..)
851 | PredicateKind
::Subtype(..)
852 | PredicateKind
::Coerce(..)
853 | PredicateKind
::RegionOutlives(..)
854 | PredicateKind
::WellFormed(..)
855 | PredicateKind
::ObjectSafe(..)
856 | PredicateKind
::ClosureKind(..)
857 | PredicateKind
::TypeOutlives(..)
858 | PredicateKind
::ConstEvaluatable(..)
859 | PredicateKind
::ConstEquate(..)
860 | PredicateKind
::TypeWellFormedFromEnv(..) => None
,
864 pub fn to_opt_type_outlives(self) -> Option
<PolyTypeOutlivesPredicate
<'tcx
>> {
865 let predicate
= self.kind();
866 match predicate
.skip_binder() {
867 PredicateKind
::TypeOutlives(data
) => Some(predicate
.rebind(data
)),
868 PredicateKind
::Trait(..)
869 | PredicateKind
::Projection(..)
870 | PredicateKind
::Subtype(..)
871 | PredicateKind
::Coerce(..)
872 | PredicateKind
::RegionOutlives(..)
873 | PredicateKind
::WellFormed(..)
874 | PredicateKind
::ObjectSafe(..)
875 | PredicateKind
::ClosureKind(..)
876 | PredicateKind
::ConstEvaluatable(..)
877 | PredicateKind
::ConstEquate(..)
878 | PredicateKind
::TypeWellFormedFromEnv(..) => None
,
883 /// Represents the bounds declared on a particular set of type
884 /// parameters. Should eventually be generalized into a flag list of
885 /// where-clauses. You can obtain an `InstantiatedPredicates` list from a
886 /// `GenericPredicates` by using the `instantiate` method. Note that this method
887 /// reflects an important semantic invariant of `InstantiatedPredicates`: while
888 /// the `GenericPredicates` are expressed in terms of the bound type
889 /// parameters of the impl/trait/whatever, an `InstantiatedPredicates` instance
890 /// represented a set of bounds for some particular instantiation,
891 /// meaning that the generic parameters have been substituted with
896 /// struct Foo<T, U: Bar<T>> { ... }
898 /// Here, the `GenericPredicates` for `Foo` would contain a list of bounds like
899 /// `[[], [U:Bar<T>]]`. Now if there were some particular reference
900 /// like `Foo<isize,usize>`, then the `InstantiatedPredicates` would be `[[],
901 /// [usize:Bar<isize>]]`.
902 #[derive(Clone, Debug, TypeFoldable)]
903 pub struct InstantiatedPredicates
<'tcx
> {
904 pub predicates
: Vec
<Predicate
<'tcx
>>,
905 pub spans
: Vec
<Span
>,
908 impl<'tcx
> InstantiatedPredicates
<'tcx
> {
909 pub fn empty() -> InstantiatedPredicates
<'tcx
> {
910 InstantiatedPredicates { predicates: vec![], spans: vec![] }
913 pub fn is_empty(&self) -> bool
{
914 self.predicates
.is_empty()
918 #[derive(Copy, Clone, Debug, PartialEq, Eq, HashStable, TyEncodable, TyDecodable, TypeFoldable)]
919 pub struct OpaqueTypeKey
<'tcx
> {
921 pub substs
: SubstsRef
<'tcx
>,
924 rustc_index
::newtype_index
! {
925 /// "Universes" are used during type- and trait-checking in the
926 /// presence of `for<..>` binders to control what sets of names are
927 /// visible. Universes are arranged into a tree: the root universe
928 /// contains names that are always visible. Each child then adds a new
929 /// set of names that are visible, in addition to those of its parent.
930 /// We say that the child universe "extends" the parent universe with
933 /// To make this more concrete, consider this program:
937 /// fn bar<T>(x: T) {
938 /// let y: for<'a> fn(&'a u8, Foo) = ...;
942 /// The struct name `Foo` is in the root universe U0. But the type
943 /// parameter `T`, introduced on `bar`, is in an extended universe U1
944 /// -- i.e., within `bar`, we can name both `T` and `Foo`, but outside
945 /// of `bar`, we cannot name `T`. Then, within the type of `y`, the
946 /// region `'a` is in a universe U2 that extends U1, because we can
947 /// name it inside the fn type but not outside.
949 /// Universes are used to do type- and trait-checking around these
950 /// "forall" binders (also called **universal quantification**). The
951 /// idea is that when, in the body of `bar`, we refer to `T` as a
952 /// type, we aren't referring to any type in particular, but rather a
953 /// kind of "fresh" type that is distinct from all other types we have
954 /// actually declared. This is called a **placeholder** type, and we
955 /// use universes to talk about this. In other words, a type name in
956 /// universe 0 always corresponds to some "ground" type that the user
957 /// declared, but a type name in a non-zero universe is a placeholder
958 /// type -- an idealized representative of "types in general" that we
959 /// use for checking generic functions.
960 pub struct UniverseIndex
{
962 DEBUG_FORMAT
= "U{}",
967 pub const ROOT
: UniverseIndex
= UniverseIndex
::from_u32(0);
969 /// Returns the "next" universe index in order -- this new index
970 /// is considered to extend all previous universes. This
971 /// corresponds to entering a `forall` quantifier. So, for
972 /// example, suppose we have this type in universe `U`:
975 /// for<'a> fn(&'a u32)
978 /// Once we "enter" into this `for<'a>` quantifier, we are in a
979 /// new universe that extends `U` -- in this new universe, we can
980 /// name the region `'a`, but that region was not nameable from
981 /// `U` because it was not in scope there.
982 pub fn next_universe(self) -> UniverseIndex
{
983 UniverseIndex
::from_u32(self.private
.checked_add(1).unwrap())
986 /// Returns `true` if `self` can name a name from `other` -- in other words,
987 /// if the set of names in `self` is a superset of those in
988 /// `other` (`self >= other`).
989 pub fn can_name(self, other
: UniverseIndex
) -> bool
{
990 self.private
>= other
.private
993 /// Returns `true` if `self` cannot name some names from `other` -- in other
994 /// words, if the set of names in `self` is a strict subset of
995 /// those in `other` (`self < other`).
996 pub fn cannot_name(self, other
: UniverseIndex
) -> bool
{
997 self.private
< other
.private
1001 /// The "placeholder index" fully defines a placeholder region, type, or const. Placeholders are
1002 /// identified by both a universe, as well as a name residing within that universe. Distinct bound
1003 /// regions/types/consts within the same universe simply have an unknown relationship to one
1005 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TyEncodable, TyDecodable, PartialOrd, Ord)]
1006 pub struct Placeholder
<T
> {
1007 pub universe
: UniverseIndex
,
1011 impl<'a
, T
> HashStable
<StableHashingContext
<'a
>> for Placeholder
<T
>
1013 T
: HashStable
<StableHashingContext
<'a
>>,
1015 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
1016 self.universe
.hash_stable(hcx
, hasher
);
1017 self.name
.hash_stable(hcx
, hasher
);
1021 pub type PlaceholderRegion
= Placeholder
<BoundRegionKind
>;
1023 pub type PlaceholderType
= Placeholder
<BoundVar
>;
1025 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable)]
1026 #[derive(TyEncodable, TyDecodable, PartialOrd, Ord)]
1027 pub struct BoundConst
<'tcx
> {
1032 pub type PlaceholderConst
<'tcx
> = Placeholder
<BoundConst
<'tcx
>>;
1034 /// A `DefId` which, in case it is a const argument, is potentially bundled with
1035 /// the `DefId` of the generic parameter it instantiates.
1037 /// This is used to avoid calls to `type_of` for const arguments during typeck
1038 /// which cause cycle errors.
1043 /// fn foo<const N: usize>(&self) -> [u8; N] { [0; N] }
1044 /// // ^ const parameter
1048 /// fn foo<const M: u8>(&self) -> usize { 42 }
1049 /// // ^ const parameter
1054 /// let _b = a.foo::<{ 3 + 7 }>();
1055 /// // ^^^^^^^^^ const argument
1059 /// Let's look at the call `a.foo::<{ 3 + 7 }>()` here. We do not know
1060 /// which `foo` is used until we know the type of `a`.
1062 /// We only know the type of `a` once we are inside of `typeck(main)`.
1063 /// We also end up normalizing the type of `_b` during `typeck(main)` which
1064 /// requires us to evaluate the const argument.
1066 /// To evaluate that const argument we need to know its type,
1067 /// which we would get using `type_of(const_arg)`. This requires us to
1068 /// resolve `foo` as it can be either `usize` or `u8` in this example.
1069 /// However, resolving `foo` once again requires `typeck(main)` to get the type of `a`,
1070 /// which results in a cycle.
1072 /// In short we must not call `type_of(const_arg)` during `typeck(main)`.
1074 /// When first creating the `ty::Const` of the const argument inside of `typeck` we have
1075 /// already resolved `foo` so we know which const parameter this argument instantiates.
1076 /// This means that we also know the expected result of `type_of(const_arg)` even if we
1077 /// aren't allowed to call that query: it is equal to `type_of(const_param)` which is
1078 /// trivial to compute.
1080 /// If we now want to use that constant in a place which potentionally needs its type
1081 /// we also pass the type of its `const_param`. This is the point of `WithOptConstParam`,
1082 /// except that instead of a `Ty` we bundle the `DefId` of the const parameter.
1083 /// Meaning that we need to use `type_of(const_param_did)` if `const_param_did` is `Some`
1084 /// to get the type of `did`.
1085 #[derive(Copy, Clone, Debug, TypeFoldable, Lift, TyEncodable, TyDecodable)]
1086 #[derive(PartialEq, Eq, PartialOrd, Ord)]
1087 #[derive(Hash, HashStable)]
1088 pub struct WithOptConstParam
<T
> {
1090 /// The `DefId` of the corresponding generic parameter in case `did` is
1091 /// a const argument.
1093 /// Note that even if `did` is a const argument, this may still be `None`.
1094 /// All queries taking `WithOptConstParam` start by calling `tcx.opt_const_param_of(def.did)`
1095 /// to potentially update `param_did` in the case it is `None`.
1096 pub const_param_did
: Option
<DefId
>,
1099 impl<T
> WithOptConstParam
<T
> {
1100 /// Creates a new `WithOptConstParam` setting `const_param_did` to `None`.
1102 pub fn unknown(did
: T
) -> WithOptConstParam
<T
> {
1103 WithOptConstParam { did, const_param_did: None }
1107 impl WithOptConstParam
<LocalDefId
> {
1108 /// Returns `Some((did, param_did))` if `def_id` is a const argument,
1109 /// `None` otherwise.
1111 pub fn try_lookup(did
: LocalDefId
, tcx
: TyCtxt
<'_
>) -> Option
<(LocalDefId
, DefId
)> {
1112 tcx
.opt_const_param_of(did
).map(|param_did
| (did
, param_did
))
1115 /// In case `self` is unknown but `self.did` is a const argument, this returns
1116 /// a `WithOptConstParam` with the correct `const_param_did`.
1118 pub fn try_upgrade(self, tcx
: TyCtxt
<'_
>) -> Option
<WithOptConstParam
<LocalDefId
>> {
1119 if self.const_param_did
.is_none() {
1120 if let const_param_did @
Some(_
) = tcx
.opt_const_param_of(self.did
) {
1121 return Some(WithOptConstParam { did: self.did, const_param_did }
);
1128 pub fn to_global(self) -> WithOptConstParam
<DefId
> {
1129 WithOptConstParam { did: self.did.to_def_id(), const_param_did: self.const_param_did }
1132 pub fn def_id_for_type_of(self) -> DefId
{
1133 if let Some(did
) = self.const_param_did { did }
else { self.did.to_def_id() }
1137 impl WithOptConstParam
<DefId
> {
1138 pub fn as_local(self) -> Option
<WithOptConstParam
<LocalDefId
>> {
1141 .map(|did
| WithOptConstParam { did, const_param_did: self.const_param_did }
)
1144 pub fn as_const_arg(self) -> Option
<(LocalDefId
, DefId
)> {
1145 if let Some(param_did
) = self.const_param_did
{
1146 if let Some(did
) = self.did
.as_local() {
1147 return Some((did
, param_did
));
1154 pub fn is_local(self) -> bool
{
1158 pub fn def_id_for_type_of(self) -> DefId
{
1159 self.const_param_did
.unwrap_or(self.did
)
1163 /// When type checking, we use the `ParamEnv` to track
1164 /// details about the set of where-clauses that are in scope at this
1165 /// particular point.
1166 #[derive(Copy, Clone, Hash, PartialEq, Eq)]
1167 pub struct ParamEnv
<'tcx
> {
1168 /// This packs both caller bounds and the reveal enum into one pointer.
1170 /// Caller bounds are `Obligation`s that the caller must satisfy. This is
1171 /// basically the set of bounds on the in-scope type parameters, translated
1172 /// into `Obligation`s, and elaborated and normalized.
1174 /// Use the `caller_bounds()` method to access.
1176 /// Typically, this is `Reveal::UserFacing`, but during codegen we
1177 /// want `Reveal::All`.
1179 /// Note: This is packed, use the reveal() method to access it.
1180 packed
: CopyTaggedPtr
<&'tcx List
<Predicate
<'tcx
>>, traits
::Reveal
, true>,
1183 unsafe impl rustc_data_structures
::tagged_ptr
::Tag
for traits
::Reveal
{
1184 const BITS
: usize = 1;
1186 fn into_usize(self) -> usize {
1188 traits
::Reveal
::UserFacing
=> 0,
1189 traits
::Reveal
::All
=> 1,
1193 unsafe fn from_usize(ptr
: usize) -> Self {
1195 0 => traits
::Reveal
::UserFacing
,
1196 1 => traits
::Reveal
::All
,
1197 _
=> std
::hint
::unreachable_unchecked(),
1202 impl<'tcx
> fmt
::Debug
for ParamEnv
<'tcx
> {
1203 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
1204 f
.debug_struct("ParamEnv")
1205 .field("caller_bounds", &self.caller_bounds())
1206 .field("reveal", &self.reveal())
1211 impl<'a
, 'tcx
> HashStable
<StableHashingContext
<'a
>> for ParamEnv
<'tcx
> {
1212 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
1213 self.caller_bounds().hash_stable(hcx
, hasher
);
1214 self.reveal().hash_stable(hcx
, hasher
);
1218 impl<'tcx
> TypeFoldable
<'tcx
> for ParamEnv
<'tcx
> {
1219 fn super_fold_with
<F
: ty
::fold
::TypeFolder
<'tcx
>>(self, folder
: &mut F
) -> Self {
1220 ParamEnv
::new(self.caller_bounds().fold_with(folder
), self.reveal().fold_with(folder
))
1223 fn super_visit_with
<V
: TypeVisitor
<'tcx
>>(&self, visitor
: &mut V
) -> ControlFlow
<V
::BreakTy
> {
1224 self.caller_bounds().visit_with(visitor
)?
;
1225 self.reveal().visit_with(visitor
)
1229 impl<'tcx
> ParamEnv
<'tcx
> {
1230 /// Construct a trait environment suitable for contexts where
1231 /// there are no where-clauses in scope. Hidden types (like `impl
1232 /// Trait`) are left hidden, so this is suitable for ordinary
1235 pub fn empty() -> Self {
1236 Self::new(List
::empty(), Reveal
::UserFacing
)
1240 pub fn caller_bounds(self) -> &'tcx List
<Predicate
<'tcx
>> {
1241 self.packed
.pointer()
1245 pub fn reveal(self) -> traits
::Reveal
{
1249 /// Construct a trait environment with no where-clauses in scope
1250 /// where the values of all `impl Trait` and other hidden types
1251 /// are revealed. This is suitable for monomorphized, post-typeck
1252 /// environments like codegen or doing optimizations.
1254 /// N.B., if you want to have predicates in scope, use `ParamEnv::new`,
1255 /// or invoke `param_env.with_reveal_all()`.
1257 pub fn reveal_all() -> Self {
1258 Self::new(List
::empty(), Reveal
::All
)
1261 /// Construct a trait environment with the given set of predicates.
1263 pub fn new(caller_bounds
: &'tcx List
<Predicate
<'tcx
>>, reveal
: Reveal
) -> Self {
1264 ty
::ParamEnv { packed: CopyTaggedPtr::new(caller_bounds, reveal) }
1267 pub fn with_user_facing(mut self) -> Self {
1268 self.packed
.set_tag(Reveal
::UserFacing
);
1272 /// Returns a new parameter environment with the same clauses, but
1273 /// which "reveals" the true results of projections in all cases
1274 /// (even for associated types that are specializable). This is
1275 /// the desired behavior during codegen and certain other special
1276 /// contexts; normally though we want to use `Reveal::UserFacing`,
1277 /// which is the default.
1278 /// All opaque types in the caller_bounds of the `ParamEnv`
1279 /// will be normalized to their underlying types.
1280 /// See PR #65989 and issue #65918 for more details
1281 pub fn with_reveal_all_normalized(self, tcx
: TyCtxt
<'tcx
>) -> Self {
1282 if self.packed
.tag() == traits
::Reveal
::All
{
1286 ParamEnv
::new(tcx
.normalize_opaque_types(self.caller_bounds()), Reveal
::All
)
1289 /// Returns this same environment but with no caller bounds.
1291 pub fn without_caller_bounds(self) -> Self {
1292 Self::new(List
::empty(), self.reveal())
1295 /// Creates a suitable environment in which to perform trait
1296 /// queries on the given value. When type-checking, this is simply
1297 /// the pair of the environment plus value. But when reveal is set to
1298 /// All, then if `value` does not reference any type parameters, we will
1299 /// pair it with the empty environment. This improves caching and is generally
1302 /// N.B., we preserve the environment when type-checking because it
1303 /// is possible for the user to have wacky where-clauses like
1304 /// `where Box<u32>: Copy`, which are clearly never
1305 /// satisfiable. We generally want to behave as if they were true,
1306 /// although the surrounding function is never reachable.
1307 pub fn and
<T
: TypeFoldable
<'tcx
>>(self, value
: T
) -> ParamEnvAnd
<'tcx
, T
> {
1308 match self.reveal() {
1309 Reveal
::UserFacing
=> ParamEnvAnd { param_env: self, value }
,
1312 if value
.is_known_global() {
1313 ParamEnvAnd { param_env: self.without_caller_bounds(), value }
1315 ParamEnvAnd { param_env: self, value }
1322 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TypeFoldable)]
1323 pub struct ConstnessAnd
<T
> {
1324 pub constness
: BoundConstness
,
1328 // FIXME(ecstaticmorse): Audit all occurrences of `without_const().to_predicate(tcx)` to ensure that
1329 // the constness of trait bounds is being propagated correctly.
1330 pub trait WithConstness
: Sized
{
1332 fn with_constness(self, constness
: BoundConstness
) -> ConstnessAnd
<Self> {
1333 ConstnessAnd { constness, value: self }
1337 fn with_const_if_const(self) -> ConstnessAnd
<Self> {
1338 self.with_constness(BoundConstness
::ConstIfConst
)
1342 fn without_const(self) -> ConstnessAnd
<Self> {
1343 self.with_constness(BoundConstness
::NotConst
)
1347 impl<T
> WithConstness
for T {}
1349 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TypeFoldable)]
1350 pub struct ParamEnvAnd
<'tcx
, T
> {
1351 pub param_env
: ParamEnv
<'tcx
>,
1355 impl<'tcx
, T
> ParamEnvAnd
<'tcx
, T
> {
1356 pub fn into_parts(self) -> (ParamEnv
<'tcx
>, T
) {
1357 (self.param_env
, self.value
)
1361 impl<'a
, 'tcx
, T
> HashStable
<StableHashingContext
<'a
>> for ParamEnvAnd
<'tcx
, T
>
1363 T
: HashStable
<StableHashingContext
<'a
>>,
1365 fn hash_stable(&self, hcx
: &mut StableHashingContext
<'a
>, hasher
: &mut StableHasher
) {
1366 let ParamEnvAnd { ref param_env, ref value }
= *self;
1368 param_env
.hash_stable(hcx
, hasher
);
1369 value
.hash_stable(hcx
, hasher
);
1373 #[derive(Copy, Clone, Debug, HashStable)]
1374 pub struct Destructor
{
1375 /// The `DefId` of the destructor method
1380 #[derive(HashStable)]
1381 pub struct VariantFlags
: u32 {
1382 const NO_VARIANT_FLAGS
= 0;
1383 /// Indicates whether the field list of this variant is `#[non_exhaustive]`.
1384 const IS_FIELD_LIST_NON_EXHAUSTIVE
= 1 << 0;
1385 /// Indicates whether this variant was obtained as part of recovering from
1386 /// a syntactic error. May be incomplete or bogus.
1387 const IS_RECOVERED
= 1 << 1;
1391 /// Definition of a variant -- a struct's fields or an enum variant.
1392 #[derive(Debug, HashStable)]
1393 pub struct VariantDef
{
1394 /// `DefId` that identifies the variant itself.
1395 /// If this variant belongs to a struct or union, then this is a copy of its `DefId`.
1397 /// `DefId` that identifies the variant's constructor.
1398 /// If this variant is a struct variant, then this is `None`.
1399 pub ctor_def_id
: Option
<DefId
>,
1400 /// Variant or struct name.
1401 #[stable_hasher(project(name))]
1403 /// Discriminant of this variant.
1404 pub discr
: VariantDiscr
,
1405 /// Fields of this variant.
1406 pub fields
: Vec
<FieldDef
>,
1407 /// Type of constructor of variant.
1408 pub ctor_kind
: CtorKind
,
1409 /// Flags of the variant (e.g. is field list non-exhaustive)?
1410 flags
: VariantFlags
,
1414 /// Creates a new `VariantDef`.
1416 /// `variant_did` is the `DefId` that identifies the enum variant (if this `VariantDef`
1417 /// represents an enum variant).
1419 /// `ctor_did` is the `DefId` that identifies the constructor of unit or
1420 /// tuple-variants/structs. If this is a `struct`-variant then this should be `None`.
1422 /// `parent_did` is the `DefId` of the `AdtDef` representing the enum or struct that
1423 /// owns this variant. It is used for checking if a struct has `#[non_exhaustive]` w/out having
1424 /// to go through the redirect of checking the ctor's attributes - but compiling a small crate
1425 /// requires loading the `AdtDef`s for all the structs in the universe (e.g., coherence for any
1426 /// built-in trait), and we do not want to load attributes twice.
1428 /// If someone speeds up attribute loading to not be a performance concern, they can
1429 /// remove this hack and use the constructor `DefId` everywhere.
1432 variant_did
: Option
<DefId
>,
1433 ctor_def_id
: Option
<DefId
>,
1434 discr
: VariantDiscr
,
1435 fields
: Vec
<FieldDef
>,
1436 ctor_kind
: CtorKind
,
1440 is_field_list_non_exhaustive
: bool
,
1443 "VariantDef::new(ident = {:?}, variant_did = {:?}, ctor_def_id = {:?}, discr = {:?},
1444 fields = {:?}, ctor_kind = {:?}, adt_kind = {:?}, parent_did = {:?})",
1445 ident
, variant_did
, ctor_def_id
, discr
, fields
, ctor_kind
, adt_kind
, parent_did
,
1448 let mut flags
= VariantFlags
::NO_VARIANT_FLAGS
;
1449 if is_field_list_non_exhaustive
{
1450 flags
|= VariantFlags
::IS_FIELD_LIST_NON_EXHAUSTIVE
;
1454 flags
|= VariantFlags
::IS_RECOVERED
;
1458 def_id
: variant_did
.unwrap_or(parent_did
),
1468 /// Is this field list non-exhaustive?
1470 pub fn is_field_list_non_exhaustive(&self) -> bool
{
1471 self.flags
.intersects(VariantFlags
::IS_FIELD_LIST_NON_EXHAUSTIVE
)
1474 /// Was this variant obtained as part of recovering from a syntactic error?
1476 pub fn is_recovered(&self) -> bool
{
1477 self.flags
.intersects(VariantFlags
::IS_RECOVERED
)
1481 #[derive(Copy, Clone, Debug, PartialEq, Eq, TyEncodable, TyDecodable, HashStable)]
1482 pub enum VariantDiscr
{
1483 /// Explicit value for this variant, i.e., `X = 123`.
1484 /// The `DefId` corresponds to the embedded constant.
1487 /// The previous variant's discriminant plus one.
1488 /// For efficiency reasons, the distance from the
1489 /// last `Explicit` discriminant is being stored,
1490 /// or `0` for the first variant, if it has none.
1494 #[derive(Debug, HashStable)]
1495 pub struct FieldDef
{
1497 #[stable_hasher(project(name))]
1499 pub vis
: Visibility
,
1503 #[derive(TyEncodable, TyDecodable, Default, HashStable)]
1504 pub struct ReprFlags
: u8 {
1505 const IS_C
= 1 << 0;
1506 const IS_SIMD
= 1 << 1;
1507 const IS_TRANSPARENT
= 1 << 2;
1508 // Internal only for now. If true, don't reorder fields.
1509 const IS_LINEAR
= 1 << 3;
1510 // If true, don't expose any niche to type's context.
1511 const HIDE_NICHE
= 1 << 4;
1512 // Any of these flags being set prevent field reordering optimisation.
1513 const IS_UNOPTIMISABLE
= ReprFlags
::IS_C
.bits
|
1514 ReprFlags
::IS_SIMD
.bits
|
1515 ReprFlags
::IS_LINEAR
.bits
;
1519 /// Represents the repr options provided by the user,
1520 #[derive(Copy, Clone, Debug, Eq, PartialEq, TyEncodable, TyDecodable, Default, HashStable)]
1521 pub struct ReprOptions
{
1522 pub int
: Option
<attr
::IntType
>,
1523 pub align
: Option
<Align
>,
1524 pub pack
: Option
<Align
>,
1525 pub flags
: ReprFlags
,
1529 pub fn new(tcx
: TyCtxt
<'_
>, did
: DefId
) -> ReprOptions
{
1530 let mut flags
= ReprFlags
::empty();
1531 let mut size
= None
;
1532 let mut max_align
: Option
<Align
> = None
;
1533 let mut min_pack
: Option
<Align
> = None
;
1534 for attr
in tcx
.get_attrs(did
).iter() {
1535 for r
in attr
::find_repr_attrs(&tcx
.sess
, attr
) {
1536 flags
.insert(match r
{
1537 attr
::ReprC
=> ReprFlags
::IS_C
,
1538 attr
::ReprPacked(pack
) => {
1539 let pack
= Align
::from_bytes(pack
as u64).unwrap();
1540 min_pack
= Some(if let Some(min_pack
) = min_pack
{
1547 attr
::ReprTransparent
=> ReprFlags
::IS_TRANSPARENT
,
1548 attr
::ReprNoNiche
=> ReprFlags
::HIDE_NICHE
,
1549 attr
::ReprSimd
=> ReprFlags
::IS_SIMD
,
1550 attr
::ReprInt(i
) => {
1554 attr
::ReprAlign(align
) => {
1555 max_align
= max_align
.max(Some(Align
::from_bytes(align
as u64).unwrap()));
1562 // This is here instead of layout because the choice must make it into metadata.
1563 if !tcx
.consider_optimizing(|| format
!("Reorder fields of {:?}", tcx
.def_path_str(did
))) {
1564 flags
.insert(ReprFlags
::IS_LINEAR
);
1566 ReprOptions { int: size, align: max_align, pack: min_pack, flags }
1570 pub fn simd(&self) -> bool
{
1571 self.flags
.contains(ReprFlags
::IS_SIMD
)
1574 pub fn c(&self) -> bool
{
1575 self.flags
.contains(ReprFlags
::IS_C
)
1578 pub fn packed(&self) -> bool
{
1582 pub fn transparent(&self) -> bool
{
1583 self.flags
.contains(ReprFlags
::IS_TRANSPARENT
)
1586 pub fn linear(&self) -> bool
{
1587 self.flags
.contains(ReprFlags
::IS_LINEAR
)
1590 pub fn hide_niche(&self) -> bool
{
1591 self.flags
.contains(ReprFlags
::HIDE_NICHE
)
1594 /// Returns the discriminant type, given these `repr` options.
1595 /// This must only be called on enums!
1596 pub fn discr_type(&self) -> attr
::IntType
{
1597 self.int
.unwrap_or(attr
::SignedInt(ast
::IntTy
::Isize
))
1600 /// Returns `true` if this `#[repr()]` should inhabit "smart enum
1601 /// layout" optimizations, such as representing `Foo<&T>` as a
1603 pub fn inhibit_enum_layout_opt(&self) -> bool
{
1604 self.c() || self.int
.is_some()
1607 /// Returns `true` if this `#[repr()]` should inhibit struct field reordering
1608 /// optimizations, such as with `repr(C)`, `repr(packed(1))`, or `repr(<int>)`.
1609 pub fn inhibit_struct_field_reordering_opt(&self) -> bool
{
1610 if let Some(pack
) = self.pack
{
1611 if pack
.bytes() == 1 {
1615 self.flags
.intersects(ReprFlags
::IS_UNOPTIMISABLE
) || self.int
.is_some()
1618 /// Returns `true` if this `#[repr()]` should inhibit union ABI optimisations.
1619 pub fn inhibit_union_abi_opt(&self) -> bool
{
1624 impl<'tcx
> FieldDef
{
1625 /// Returns the type of this field. The `subst` is typically obtained
1626 /// via the second field of `TyKind::AdtDef`.
1627 pub fn ty(&self, tcx
: TyCtxt
<'tcx
>, subst
: SubstsRef
<'tcx
>) -> Ty
<'tcx
> {
1628 tcx
.type_of(self.did
).subst(tcx
, subst
)
1632 pub type Attributes
<'tcx
> = &'tcx
[ast
::Attribute
];
1634 #[derive(Debug, PartialEq, Eq)]
1635 pub enum ImplOverlapKind
{
1636 /// These impls are always allowed to overlap.
1638 /// Whether or not the impl is permitted due to the trait being a `#[marker]` trait
1641 /// These impls are allowed to overlap, but that raises
1642 /// an issue #33140 future-compatibility warning.
1644 /// Some background: in Rust 1.0, the trait-object types `Send + Sync` (today's
1645 /// `dyn Send + Sync`) and `Sync + Send` (now `dyn Sync + Send`) were different.
1647 /// The widely-used version 0.1.0 of the crate `traitobject` had accidentally relied
1648 /// that difference, making what reduces to the following set of impls:
1652 /// impl Trait for dyn Send + Sync {}
1653 /// impl Trait for dyn Sync + Send {}
1656 /// Obviously, once we made these types be identical, that code causes a coherence
1657 /// error and a fairly big headache for us. However, luckily for us, the trait
1658 /// `Trait` used in this case is basically a marker trait, and therefore having
1659 /// overlapping impls for it is sound.
1661 /// To handle this, we basically regard the trait as a marker trait, with an additional
1662 /// future-compatibility warning. To avoid accidentally "stabilizing" this feature,
1663 /// it has the following restrictions:
1665 /// 1. The trait must indeed be a marker-like trait (i.e., no items), and must be
1667 /// 2. The trait-ref of both impls must be equal.
1668 /// 3. The trait-ref of both impls must be a trait object type consisting only of
1670 /// 4. Neither of the impls can have any where-clauses.
1672 /// Once `traitobject` 0.1.0 is no longer an active concern, this hack can be removed.
1676 impl<'tcx
> TyCtxt
<'tcx
> {
1677 pub fn typeck_body(self, body
: hir
::BodyId
) -> &'tcx TypeckResults
<'tcx
> {
1678 self.typeck(self.hir().body_owner_def_id(body
))
1681 /// Returns an iterator of the `DefId`s for all body-owners in this
1682 /// crate. If you would prefer to iterate over the bodies
1683 /// themselves, you can do `self.hir().krate().body_ids.iter()`.
1684 pub fn body_owners(self) -> impl Iterator
<Item
= LocalDefId
> + Captures
<'tcx
> + 'tcx
{
1685 self.hir().krate().bodies
.keys().map(move |&body_id
| self.hir().body_owner_def_id(body_id
))
1688 pub fn par_body_owners
<F
: Fn(LocalDefId
) + sync
::Sync
+ sync
::Send
>(self, f
: F
) {
1689 par_iter(&self.hir().krate().bodies
)
1690 .for_each(|(&body_id
, _
)| f(self.hir().body_owner_def_id(body_id
)));
1693 pub fn provided_trait_methods(self, id
: DefId
) -> impl 'tcx
+ Iterator
<Item
= &'tcx AssocItem
> {
1694 self.associated_items(id
)
1695 .in_definition_order()
1696 .filter(|item
| item
.kind
== AssocKind
::Fn
&& item
.defaultness
.has_value())
1699 fn item_name_from_hir(self, def_id
: DefId
) -> Option
<Ident
> {
1700 self.hir().get_if_local(def_id
).and_then(|node
| node
.ident())
1703 fn item_name_from_def_id(self, def_id
: DefId
) -> Option
<Symbol
> {
1704 if def_id
.index
== CRATE_DEF_INDEX
{
1705 Some(self.crate_name(def_id
.krate
))
1707 let def_key
= self.def_key(def_id
);
1708 match def_key
.disambiguated_data
.data
{
1709 // The name of a constructor is that of its parent.
1710 rustc_hir
::definitions
::DefPathData
::Ctor
=> self.item_name_from_def_id(DefId
{
1711 krate
: def_id
.krate
,
1712 index
: def_key
.parent
.unwrap(),
1714 _
=> def_key
.disambiguated_data
.data
.get_opt_name(),
1719 /// Look up the name of an item across crates. This does not look at HIR.
1721 /// When possible, this function should be used for cross-crate lookups over
1722 /// [`opt_item_name`] to avoid invalidating the incremental cache. If you
1723 /// need to handle items without a name, or HIR items that will not be
1724 /// serialized cross-crate, or if you need the span of the item, use
1725 /// [`opt_item_name`] instead.
1727 /// [`opt_item_name`]: Self::opt_item_name
1728 pub fn item_name(self, id
: DefId
) -> Symbol
{
1729 // Look at cross-crate items first to avoid invalidating the incremental cache
1730 // unless we have to.
1731 self.item_name_from_def_id(id
).unwrap_or_else(|| {
1732 bug
!("item_name: no name for {:?}", self.def_path(id
));
1736 /// Look up the name and span of an item or [`Node`].
1738 /// See [`item_name`][Self::item_name] for more information.
1739 pub fn opt_item_name(self, def_id
: DefId
) -> Option
<Ident
> {
1740 // Look at the HIR first so the span will be correct if this is a local item.
1741 self.item_name_from_hir(def_id
)
1742 .or_else(|| self.item_name_from_def_id(def_id
).map(Ident
::with_dummy_span
))
1745 pub fn opt_associated_item(self, def_id
: DefId
) -> Option
<&'tcx AssocItem
> {
1746 if let DefKind
::AssocConst
| DefKind
::AssocFn
| DefKind
::AssocTy
= self.def_kind(def_id
) {
1747 Some(self.associated_item(def_id
))
1753 pub fn field_index(self, hir_id
: hir
::HirId
, typeck_results
: &TypeckResults
<'_
>) -> usize {
1754 typeck_results
.field_indices().get(hir_id
).cloned().expect("no index for a field")
1757 pub fn find_field_index(self, ident
: Ident
, variant
: &VariantDef
) -> Option
<usize> {
1758 variant
.fields
.iter().position(|field
| self.hygienic_eq(ident
, field
.ident
, variant
.def_id
))
1761 /// Returns `true` if the impls are the same polarity and the trait either
1762 /// has no items or is annotated `#[marker]` and prevents item overrides.
1763 pub fn impls_are_allowed_to_overlap(
1767 ) -> Option
<ImplOverlapKind
> {
1768 // If either trait impl references an error, they're allowed to overlap,
1769 // as one of them essentially doesn't exist.
1770 if self.impl_trait_ref(def_id1
).map_or(false, |tr
| tr
.references_error())
1771 || self.impl_trait_ref(def_id2
).map_or(false, |tr
| tr
.references_error())
1773 return Some(ImplOverlapKind
::Permitted { marker: false }
);
1776 match (self.impl_polarity(def_id1
), self.impl_polarity(def_id2
)) {
1777 (ImplPolarity
::Reservation
, _
) | (_
, ImplPolarity
::Reservation
) => {
1778 // `#[rustc_reservation_impl]` impls don't overlap with anything
1780 "impls_are_allowed_to_overlap({:?}, {:?}) = Some(Permitted) (reservations)",
1783 return Some(ImplOverlapKind
::Permitted { marker: false }
);
1785 (ImplPolarity
::Positive
, ImplPolarity
::Negative
)
1786 | (ImplPolarity
::Negative
, ImplPolarity
::Positive
) => {
1787 // `impl AutoTrait for Type` + `impl !AutoTrait for Type`
1789 "impls_are_allowed_to_overlap({:?}, {:?}) - None (differing polarities)",
1794 (ImplPolarity
::Positive
, ImplPolarity
::Positive
)
1795 | (ImplPolarity
::Negative
, ImplPolarity
::Negative
) => {}
1798 let is_marker_overlap
= {
1799 let is_marker_impl
= |def_id
: DefId
| -> bool
{
1800 let trait_ref
= self.impl_trait_ref(def_id
);
1801 trait_ref
.map_or(false, |tr
| self.trait_def(tr
.def_id
).is_marker
)
1803 is_marker_impl(def_id1
) && is_marker_impl(def_id2
)
1806 if is_marker_overlap
{
1808 "impls_are_allowed_to_overlap({:?}, {:?}) = Some(Permitted) (marker overlap)",
1811 Some(ImplOverlapKind
::Permitted { marker: true }
)
1813 if let Some(self_ty1
) = self.issue33140_self_ty(def_id1
) {
1814 if let Some(self_ty2
) = self.issue33140_self_ty(def_id2
) {
1815 if self_ty1
== self_ty2
{
1817 "impls_are_allowed_to_overlap({:?}, {:?}) - issue #33140 HACK",
1820 return Some(ImplOverlapKind
::Issue33140
);
1823 "impls_are_allowed_to_overlap({:?}, {:?}) - found {:?} != {:?}",
1824 def_id1
, def_id2
, self_ty1
, self_ty2
1830 debug
!("impls_are_allowed_to_overlap({:?}, {:?}) = None", def_id1
, def_id2
);
1835 /// Returns `ty::VariantDef` if `res` refers to a struct,
1836 /// or variant or their constructors, panics otherwise.
1837 pub fn expect_variant_res(self, res
: Res
) -> &'tcx VariantDef
{
1839 Res
::Def(DefKind
::Variant
, did
) => {
1840 let enum_did
= self.parent(did
).unwrap();
1841 self.adt_def(enum_did
).variant_with_id(did
)
1843 Res
::Def(DefKind
::Struct
| DefKind
::Union
, did
) => self.adt_def(did
).non_enum_variant(),
1844 Res
::Def(DefKind
::Ctor(CtorOf
::Variant
, ..), variant_ctor_did
) => {
1845 let variant_did
= self.parent(variant_ctor_did
).unwrap();
1846 let enum_did
= self.parent(variant_did
).unwrap();
1847 self.adt_def(enum_did
).variant_with_ctor_id(variant_ctor_did
)
1849 Res
::Def(DefKind
::Ctor(CtorOf
::Struct
, ..), ctor_did
) => {
1850 let struct_did
= self.parent(ctor_did
).expect("struct ctor has no parent");
1851 self.adt_def(struct_did
).non_enum_variant()
1853 _
=> bug
!("expect_variant_res used with unexpected res {:?}", res
),
1857 /// Returns the possibly-auto-generated MIR of a `(DefId, Subst)` pair.
1858 pub fn instance_mir(self, instance
: ty
::InstanceDef
<'tcx
>) -> &'tcx Body
<'tcx
> {
1860 ty
::InstanceDef
::Item(def
) => match self.def_kind(def
.did
) {
1863 | DefKind
::AssocConst
1865 | DefKind
::AnonConst
=> self.mir_for_ctfe_opt_const_arg(def
),
1866 // If the caller wants `mir_for_ctfe` of a function they should not be using
1867 // `instance_mir`, so we'll assume const fn also wants the optimized version.
1869 assert_eq
!(def
.const_param_did
, None
);
1870 self.optimized_mir(def
.did
)
1873 ty
::InstanceDef
::VtableShim(..)
1874 | ty
::InstanceDef
::ReifyShim(..)
1875 | ty
::InstanceDef
::Intrinsic(..)
1876 | ty
::InstanceDef
::FnPtrShim(..)
1877 | ty
::InstanceDef
::Virtual(..)
1878 | ty
::InstanceDef
::ClosureOnceShim { .. }
1879 | ty
::InstanceDef
::DropGlue(..)
1880 | ty
::InstanceDef
::CloneShim(..) => self.mir_shims(instance
),
1884 /// Gets the attributes of a definition.
1885 pub fn get_attrs(self, did
: DefId
) -> Attributes
<'tcx
> {
1886 if let Some(did
) = did
.as_local() {
1887 self.hir().attrs(self.hir().local_def_id_to_hir_id(did
))
1889 self.item_attrs(did
)
1893 /// Determines whether an item is annotated with an attribute.
1894 pub fn has_attr(self, did
: DefId
, attr
: Symbol
) -> bool
{
1895 self.sess
.contains_name(&self.get_attrs(did
), attr
)
1898 /// Returns `true` if this is an `auto trait`.
1899 pub fn trait_is_auto(self, trait_def_id
: DefId
) -> bool
{
1900 self.trait_def(trait_def_id
).has_auto_impl
1903 /// Returns layout of a generator. Layout might be unavailable if the
1904 /// generator is tainted by errors.
1905 pub fn generator_layout(self, def_id
: DefId
) -> Option
<&'tcx GeneratorLayout
<'tcx
>> {
1906 self.optimized_mir(def_id
).generator_layout()
1909 /// Given the `DefId` of an impl, returns the `DefId` of the trait it implements.
1910 /// If it implements no trait, returns `None`.
1911 pub fn trait_id_of_impl(self, def_id
: DefId
) -> Option
<DefId
> {
1912 self.impl_trait_ref(def_id
).map(|tr
| tr
.def_id
)
1915 /// If the given defid describes a method belonging to an impl, returns the
1916 /// `DefId` of the impl that the method belongs to; otherwise, returns `None`.
1917 pub fn impl_of_method(self, def_id
: DefId
) -> Option
<DefId
> {
1918 self.opt_associated_item(def_id
).and_then(|trait_item
| match trait_item
.container
{
1919 TraitContainer(_
) => None
,
1920 ImplContainer(def_id
) => Some(def_id
),
1924 /// Looks up the span of `impl_did` if the impl is local; otherwise returns `Err`
1925 /// with the name of the crate containing the impl.
1926 pub fn span_of_impl(self, impl_did
: DefId
) -> Result
<Span
, Symbol
> {
1927 if let Some(impl_did
) = impl_did
.as_local() {
1928 let hir_id
= self.hir().local_def_id_to_hir_id(impl_did
);
1929 Ok(self.hir().span(hir_id
))
1931 Err(self.crate_name(impl_did
.krate
))
1935 /// Hygienically compares a use-site name (`use_name`) for a field or an associated item with
1936 /// its supposed definition name (`def_name`). The method also needs `DefId` of the supposed
1937 /// definition's parent/scope to perform comparison.
1938 pub fn hygienic_eq(self, use_name
: Ident
, def_name
: Ident
, def_parent_def_id
: DefId
) -> bool
{
1939 // We could use `Ident::eq` here, but we deliberately don't. The name
1940 // comparison fails frequently, and we want to avoid the expensive
1941 // `normalize_to_macros_2_0()` calls required for the span comparison whenever possible.
1942 use_name
.name
== def_name
.name
1946 .hygienic_eq(def_name
.span
.ctxt(), self.expn_that_defined(def_parent_def_id
))
1949 pub fn adjust_ident(self, mut ident
: Ident
, scope
: DefId
) -> Ident
{
1950 ident
.span
.normalize_to_macros_2_0_and_adjust(self.expn_that_defined(scope
));
1954 pub fn adjust_ident_and_get_scope(
1959 ) -> (Ident
, DefId
) {
1962 .normalize_to_macros_2_0_and_adjust(self.expn_that_defined(scope
))
1963 .and_then(|actual_expansion
| actual_expansion
.expn_data().parent_module
)
1964 .unwrap_or_else(|| self.parent_module(block
).to_def_id());
1968 pub fn is_object_safe(self, key
: DefId
) -> bool
{
1969 self.object_safety_violations(key
).is_empty()
1973 /// Yields the parent function's `DefId` if `def_id` is an `impl Trait` definition.
1974 pub fn is_impl_trait_defn(tcx
: TyCtxt
<'_
>, def_id
: DefId
) -> Option
<DefId
> {
1975 if let Some(def_id
) = def_id
.as_local() {
1976 if let Node
::Item(item
) = tcx
.hir().get(tcx
.hir().local_def_id_to_hir_id(def_id
)) {
1977 if let hir
::ItemKind
::OpaqueTy(ref opaque_ty
) = item
.kind
{
1978 return opaque_ty
.impl_trait_fn
;
1985 pub fn int_ty(ity
: ast
::IntTy
) -> IntTy
{
1987 ast
::IntTy
::Isize
=> IntTy
::Isize
,
1988 ast
::IntTy
::I8
=> IntTy
::I8
,
1989 ast
::IntTy
::I16
=> IntTy
::I16
,
1990 ast
::IntTy
::I32
=> IntTy
::I32
,
1991 ast
::IntTy
::I64
=> IntTy
::I64
,
1992 ast
::IntTy
::I128
=> IntTy
::I128
,
1996 pub fn uint_ty(uty
: ast
::UintTy
) -> UintTy
{
1998 ast
::UintTy
::Usize
=> UintTy
::Usize
,
1999 ast
::UintTy
::U8
=> UintTy
::U8
,
2000 ast
::UintTy
::U16
=> UintTy
::U16
,
2001 ast
::UintTy
::U32
=> UintTy
::U32
,
2002 ast
::UintTy
::U64
=> UintTy
::U64
,
2003 ast
::UintTy
::U128
=> UintTy
::U128
,
2007 pub fn float_ty(fty
: ast
::FloatTy
) -> FloatTy
{
2009 ast
::FloatTy
::F32
=> FloatTy
::F32
,
2010 ast
::FloatTy
::F64
=> FloatTy
::F64
,
2014 pub fn ast_int_ty(ity
: IntTy
) -> ast
::IntTy
{
2016 IntTy
::Isize
=> ast
::IntTy
::Isize
,
2017 IntTy
::I8
=> ast
::IntTy
::I8
,
2018 IntTy
::I16
=> ast
::IntTy
::I16
,
2019 IntTy
::I32
=> ast
::IntTy
::I32
,
2020 IntTy
::I64
=> ast
::IntTy
::I64
,
2021 IntTy
::I128
=> ast
::IntTy
::I128
,
2025 pub fn ast_uint_ty(uty
: UintTy
) -> ast
::UintTy
{
2027 UintTy
::Usize
=> ast
::UintTy
::Usize
,
2028 UintTy
::U8
=> ast
::UintTy
::U8
,
2029 UintTy
::U16
=> ast
::UintTy
::U16
,
2030 UintTy
::U32
=> ast
::UintTy
::U32
,
2031 UintTy
::U64
=> ast
::UintTy
::U64
,
2032 UintTy
::U128
=> ast
::UintTy
::U128
,
2036 pub fn provide(providers
: &mut ty
::query
::Providers
) {
2037 closure
::provide(providers
);
2038 context
::provide(providers
);
2039 erase_regions
::provide(providers
);
2040 layout
::provide(providers
);
2041 util
::provide(providers
);
2042 print
::provide(providers
);
2043 super::util
::bug
::provide(providers
);
2044 super::middle
::provide(providers
);
2045 *providers
= ty
::query
::Providers
{
2046 trait_impls_of
: trait_def
::trait_impls_of_provider
,
2047 type_uninhabited_from
: inhabitedness
::type_uninhabited_from
,
2048 const_param_default
: consts
::const_param_default
,
2053 /// A map for the local crate mapping each type to a vector of its
2054 /// inherent impls. This is not meant to be used outside of coherence;
2055 /// rather, you should request the vector for a specific type via
2056 /// `tcx.inherent_impls(def_id)` so as to minimize your dependencies
2057 /// (constructing this map requires touching the entire crate).
2058 #[derive(Clone, Debug, Default, HashStable)]
2059 pub struct CrateInherentImpls
{
2060 pub inherent_impls
: LocalDefIdMap
<Vec
<DefId
>>,
2063 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, TyEncodable, HashStable)]
2064 pub struct SymbolName
<'tcx
> {
2065 /// `&str` gives a consistent ordering, which ensures reproducible builds.
2066 pub name
: &'tcx
str,
2069 impl<'tcx
> SymbolName
<'tcx
> {
2070 pub fn new(tcx
: TyCtxt
<'tcx
>, name
: &str) -> SymbolName
<'tcx
> {
2072 name
: unsafe { str::from_utf8_unchecked(tcx.arena.alloc_slice(name.as_bytes())) }
,
2077 impl<'tcx
> fmt
::Display
for SymbolName
<'tcx
> {
2078 fn fmt(&self, fmt
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
2079 fmt
::Display
::fmt(&self.name
, fmt
)
2083 impl<'tcx
> fmt
::Debug
for SymbolName
<'tcx
> {
2084 fn fmt(&self, fmt
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
2085 fmt
::Display
::fmt(&self.name
, fmt
)