1 // ignore-tidy-filelength
3 pub use self::Variance::*;
4 pub use self::AssocItemContainer::*;
5 pub use self::BorrowKind::*;
6 pub use self::IntVarValue::*;
7 pub use self::fold::{TypeFoldable, TypeVisitor};
9 use crate::hir::{map as hir_map, GlobMap, TraitMap};
11 use crate::hir::def::{Res, DefKind, CtorOf, CtorKind, ExportMap};
12 use crate::hir::def_id::{CrateNum, DefId, LocalDefId, CRATE_DEF_INDEX, LOCAL_CRATE};
13 use rustc_data_structures::svh::Svh;
14 use rustc_macros::HashStable;
15 use crate::ich::Fingerprint;
16 use crate::ich::StableHashingContext;
17 use crate::infer::canonical::Canonical;
18 use crate::middle::cstore::CrateStoreDyn;
19 use crate::middle::lang_items::{FnTraitLangItem, FnMutTraitLangItem, FnOnceTraitLangItem};
20 use crate::middle::resolve_lifetime::ObjectLifetimeDefault;
22 use crate::mir::interpret::{GlobalId, ErrorHandled};
23 use crate::mir::GeneratorLayout;
24 use crate::session::CrateDisambiguator;
25 use crate::traits::{self, Reveal};
27 use crate::ty::layout::VariantIdx;
28 use crate::ty::subst::{Subst, InternalSubsts, SubstsRef};
29 use crate::ty::util::{IntTypeExt, Discr};
30 use crate::ty::walk::TypeWalker;
31 use crate::util::captures::Captures;
32 use crate::util::nodemap::{NodeMap, NodeSet, DefIdMap, FxHashMap};
33 use arena::SyncDroplessArena;
34 use crate::session::DataTypeKind;
36 use rustc_serialize::{self, Encodable, Encoder};
37 use rustc_target::abi::Align;
38 use std::cell::RefCell;
39 use std::cmp::{self, Ordering};
41 use std::hash::{Hash, Hasher};
43 use rustc_data_structures::sync::{self, Lrc, ParallelIterator, par_iter};
47 use syntax::ast::{self, Name, Ident, NodeId};
49 use syntax_pos::symbol::{kw, sym, Symbol};
50 use syntax_pos::hygiene::ExpnId;
54 use rustc_data_structures::fx::{FxIndexMap};
55 use rustc_data_structures::stable_hasher::{StableHasher, HashStable};
56 use rustc_index::vec::{Idx, IndexVec};
60 pub use self::sty::{Binder, BoundTy, BoundTyKind, BoundVar, DebruijnIndex, INNERMOST};
61 pub use self::sty::{FnSig, GenSig, CanonicalPolyFnSig, PolyFnSig, PolyGenSig};
62 pub use self::sty::{InferTy, ParamTy, ParamConst, InferConst, ProjectionTy, ExistentialPredicate};
63 pub use self::sty::{ClosureSubsts, GeneratorSubsts, UpvarSubsts, TypeAndMut};
64 pub use self::sty::{TraitRef, TyKind, PolyTraitRef};
65 pub use self::sty::{ExistentialTraitRef, PolyExistentialTraitRef};
66 pub use self::sty::{ExistentialProjection, PolyExistentialProjection, Const};
67 pub use self::sty::{BoundRegion, EarlyBoundRegion, FreeRegion, Region};
68 pub use self::sty::RegionKind;
69 pub use self::sty::{TyVid, IntVid, FloatVid, ConstVid, RegionVid};
70 pub use self::sty::BoundRegion::*;
71 pub use self::sty::InferTy::*;
72 pub use self::sty::RegionKind::*;
73 pub use self::sty::TyKind::*;
75 pub use self::binding::BindingMode;
76 pub use self::binding::BindingMode::*;
78 pub use self::context::{TyCtxt, FreeRegionInfo, AllArenas, tls, keep_local};
79 pub use self::context::{Lift, GeneratorInteriorTypeCause, TypeckTables, CtxtInterners, GlobalCtxt};
80 pub use self::context::{
81 UserTypeAnnotationIndex, UserType, CanonicalUserType,
82 CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, ResolvedOpaqueTy,
85 pub use self::instance::{Instance, InstanceDef};
87 pub use self::structural_match::search_for_structural_match_violation;
88 pub use self::structural_match::type_marked_structural;
89 pub use self::structural_match::NonStructuralMatchTy;
91 pub use self::trait_def::TraitDef;
93 pub use self::query::queries;
106 pub mod inhabitedness;
122 mod structural_impls;
123 mod structural_match;
128 pub struct ResolverOutputs {
129 pub definitions: hir_map::Definitions,
130 pub cstore: Box<CrateStoreDyn>,
131 pub extern_crate_map: NodeMap<CrateNum>,
132 pub trait_map: TraitMap,
133 pub maybe_unused_trait_imports: NodeSet,
134 pub maybe_unused_extern_crates: Vec<(NodeId, Span)>,
135 pub export_map: ExportMap<NodeId>,
136 pub glob_map: GlobMap,
137 /// Extern prelude entries. The value is `true` if the entry was introduced
138 /// via `extern crate` item and not `--extern` option or compiler built-in.
139 pub extern_prelude: FxHashMap<Name, bool>,
142 #[derive(Clone, Copy, PartialEq, Eq, Debug, HashStable)]
143 pub enum AssocItemContainer {
144 TraitContainer(DefId),
145 ImplContainer(DefId),
148 impl AssocItemContainer {
149 /// Asserts that this is the `DefId` of an associated item declared
150 /// in a trait, and returns the trait `DefId`.
151 pub fn assert_trait(&self) -> DefId {
153 TraitContainer(id) => id,
154 _ => bug!("associated item has wrong container type: {:?}", self)
158 pub fn id(&self) -> DefId {
160 TraitContainer(id) => id,
161 ImplContainer(id) => id,
166 /// The "header" of an impl is everything outside the body: a Self type, a trait
167 /// ref (in the case of a trait impl), and a set of predicates (from the
168 /// bounds / where-clauses).
169 #[derive(Clone, Debug, TypeFoldable)]
170 pub struct ImplHeader<'tcx> {
171 pub impl_def_id: DefId,
172 pub self_ty: Ty<'tcx>,
173 pub trait_ref: Option<TraitRef<'tcx>>,
174 pub predicates: Vec<Predicate<'tcx>>,
177 #[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, HashStable)]
178 pub enum ImplPolarity {
179 /// `impl Trait for Type`
181 /// `impl !Trait for Type`
183 /// `#[rustc_reservation_impl] impl Trait for Type`
185 /// This is a "stability hack", not a real Rust feature.
186 /// See #64631 for details.
190 #[derive(Copy, Clone, Debug, PartialEq, HashStable)]
191 pub struct AssocItem {
193 #[stable_hasher(project(name))]
197 pub defaultness: hir::Defaultness,
198 pub container: AssocItemContainer,
200 /// Whether this is a method with an explicit self
201 /// as its first argument, allowing method calls.
202 pub method_has_self_argument: bool,
205 #[derive(Copy, Clone, PartialEq, Debug, HashStable)]
214 pub fn def_kind(&self) -> DefKind {
216 AssocKind::Const => DefKind::AssocConst,
217 AssocKind::Method => DefKind::Method,
218 AssocKind::Type => DefKind::AssocTy,
219 AssocKind::OpaqueTy => DefKind::AssocOpaqueTy,
223 /// Tests whether the associated item admits a non-trivial implementation
225 pub fn relevant_for_never(&self) -> bool {
227 AssocKind::OpaqueTy |
229 AssocKind::Type => true,
230 // FIXME(canndrew): Be more thorough here, check if any argument is uninhabited.
231 AssocKind::Method => !self.method_has_self_argument,
235 pub fn signature(&self, tcx: TyCtxt<'_>) -> String {
237 ty::AssocKind::Method => {
238 // We skip the binder here because the binder would deanonymize all
239 // late-bound regions, and we don't want method signatures to show up
240 // `as for<'r> fn(&'r MyType)`. Pretty-printing handles late-bound
241 // regions just fine, showing `fn(&MyType)`.
242 tcx.fn_sig(self.def_id).skip_binder().to_string()
244 ty::AssocKind::Type => format!("type {};", self.ident),
245 // FIXME(type_alias_impl_trait): we should print bounds here too.
246 ty::AssocKind::OpaqueTy => format!("type {};", self.ident),
247 ty::AssocKind::Const => {
248 format!("const {}: {:?};", self.ident, tcx.type_of(self.def_id))
254 #[derive(Clone, Debug, PartialEq, Eq, Copy, RustcEncodable, RustcDecodable, HashStable)]
255 pub enum Visibility {
256 /// Visible everywhere (including in other crates).
258 /// Visible only in the given crate-local module.
260 /// Not visible anywhere in the local crate. This is the visibility of private external items.
264 pub trait DefIdTree: Copy {
265 fn parent(self, id: DefId) -> Option<DefId>;
267 fn is_descendant_of(self, mut descendant: DefId, ancestor: DefId) -> bool {
268 if descendant.krate != ancestor.krate {
272 while descendant != ancestor {
273 match self.parent(descendant) {
274 Some(parent) => descendant = parent,
275 None => return false,
282 impl<'tcx> DefIdTree for TyCtxt<'tcx> {
283 fn parent(self, id: DefId) -> Option<DefId> {
284 self.def_key(id).parent.map(|index| DefId { index: index, ..id })
289 pub fn from_hir(visibility: &hir::Visibility, id: hir::HirId, tcx: TyCtxt<'_>) -> Self {
290 match visibility.node {
291 hir::VisibilityKind::Public => Visibility::Public,
292 hir::VisibilityKind::Crate(_) => Visibility::Restricted(DefId::local(CRATE_DEF_INDEX)),
293 hir::VisibilityKind::Restricted { ref path, .. } => match path.res {
294 // If there is no resolution, `resolve` will have already reported an error, so
295 // assume that the visibility is public to avoid reporting more privacy errors.
296 Res::Err => Visibility::Public,
297 def => Visibility::Restricted(def.def_id()),
299 hir::VisibilityKind::Inherited => {
300 Visibility::Restricted(tcx.hir().get_module_parent(id))
305 /// Returns `true` if an item with this visibility is accessible from the given block.
306 pub fn is_accessible_from<T: DefIdTree>(self, module: DefId, tree: T) -> bool {
307 let restriction = match self {
308 // Public items are visible everywhere.
309 Visibility::Public => return true,
310 // Private items from other crates are visible nowhere.
311 Visibility::Invisible => return false,
312 // Restricted items are visible in an arbitrary local module.
313 Visibility::Restricted(other) if other.krate != module.krate => return false,
314 Visibility::Restricted(module) => module,
317 tree.is_descendant_of(module, restriction)
320 /// Returns `true` if this visibility is at least as accessible as the given visibility
321 pub fn is_at_least<T: DefIdTree>(self, vis: Visibility, tree: T) -> bool {
322 let vis_restriction = match vis {
323 Visibility::Public => return self == Visibility::Public,
324 Visibility::Invisible => return true,
325 Visibility::Restricted(module) => module,
328 self.is_accessible_from(vis_restriction, tree)
331 // Returns `true` if this item is visible anywhere in the local crate.
332 pub fn is_visible_locally(self) -> bool {
334 Visibility::Public => true,
335 Visibility::Restricted(def_id) => def_id.is_local(),
336 Visibility::Invisible => false,
341 #[derive(Copy, Clone, PartialEq, RustcDecodable, RustcEncodable, HashStable)]
343 Covariant, // T<A> <: T<B> iff A <: B -- e.g., function return type
344 Invariant, // T<A> <: T<B> iff B == A -- e.g., type of mutable cell
345 Contravariant, // T<A> <: T<B> iff B <: A -- e.g., function param type
346 Bivariant, // T<A> <: T<B> -- e.g., unused type parameter
349 /// The crate variances map is computed during typeck and contains the
350 /// variance of every item in the local crate. You should not use it
351 /// directly, because to do so will make your pass dependent on the
352 /// HIR of every item in the local crate. Instead, use
353 /// `tcx.variances_of()` to get the variance for a *particular*
355 #[derive(HashStable)]
356 pub struct CrateVariancesMap<'tcx> {
357 /// For each item with generics, maps to a vector of the variance
358 /// of its generics. If an item has no generics, it will have no
360 pub variances: FxHashMap<DefId, &'tcx [ty::Variance]>,
364 /// `a.xform(b)` combines the variance of a context with the
365 /// variance of a type with the following meaning. If we are in a
366 /// context with variance `a`, and we encounter a type argument in
367 /// a position with variance `b`, then `a.xform(b)` is the new
368 /// variance with which the argument appears.
374 /// Here, the "ambient" variance starts as covariant. `*mut T` is
375 /// invariant with respect to `T`, so the variance in which the
376 /// `Vec<i32>` appears is `Covariant.xform(Invariant)`, which
377 /// yields `Invariant`. Now, the type `Vec<T>` is covariant with
378 /// respect to its type argument `T`, and hence the variance of
379 /// the `i32` here is `Invariant.xform(Covariant)`, which results
380 /// (again) in `Invariant`.
384 /// fn(*const Vec<i32>, *mut Vec<i32)
386 /// The ambient variance is covariant. A `fn` type is
387 /// contravariant with respect to its parameters, so the variance
388 /// within which both pointer types appear is
389 /// `Covariant.xform(Contravariant)`, or `Contravariant`. `*const
390 /// T` is covariant with respect to `T`, so the variance within
391 /// which the first `Vec<i32>` appears is
392 /// `Contravariant.xform(Covariant)` or `Contravariant`. The same
393 /// is true for its `i32` argument. In the `*mut T` case, the
394 /// variance of `Vec<i32>` is `Contravariant.xform(Invariant)`,
395 /// and hence the outermost type is `Invariant` with respect to
396 /// `Vec<i32>` (and its `i32` argument).
398 /// Source: Figure 1 of "Taming the Wildcards:
399 /// Combining Definition- and Use-Site Variance" published in PLDI'11.
400 pub fn xform(self, v: ty::Variance) -> ty::Variance {
402 // Figure 1, column 1.
403 (ty::Covariant, ty::Covariant) => ty::Covariant,
404 (ty::Covariant, ty::Contravariant) => ty::Contravariant,
405 (ty::Covariant, ty::Invariant) => ty::Invariant,
406 (ty::Covariant, ty::Bivariant) => ty::Bivariant,
408 // Figure 1, column 2.
409 (ty::Contravariant, ty::Covariant) => ty::Contravariant,
410 (ty::Contravariant, ty::Contravariant) => ty::Covariant,
411 (ty::Contravariant, ty::Invariant) => ty::Invariant,
412 (ty::Contravariant, ty::Bivariant) => ty::Bivariant,
414 // Figure 1, column 3.
415 (ty::Invariant, _) => ty::Invariant,
417 // Figure 1, column 4.
418 (ty::Bivariant, _) => ty::Bivariant,
423 // Contains information needed to resolve types and (in the future) look up
424 // the types of AST nodes.
425 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
426 pub struct CReaderCacheKey {
431 // Flags that we track on types. These flags are propagated upwards
432 // through the type during type construction, so that we can quickly
433 // check whether the type has various kinds of types in it without
434 // recursing over the type itself.
436 pub struct TypeFlags: u32 {
437 const HAS_PARAMS = 1 << 0;
438 const HAS_TY_INFER = 1 << 1;
439 const HAS_RE_INFER = 1 << 2;
440 const HAS_RE_PLACEHOLDER = 1 << 3;
442 /// Does this have any `ReEarlyBound` regions? Used to
443 /// determine whether substitition is required, since those
444 /// represent regions that are bound in a `ty::Generics` and
445 /// hence may be substituted.
446 const HAS_RE_EARLY_BOUND = 1 << 4;
448 /// Does this have any region that "appears free" in the type?
449 /// Basically anything but `ReLateBound` and `ReErased`.
450 const HAS_FREE_REGIONS = 1 << 5;
452 /// Is an error type reachable?
453 const HAS_TY_ERR = 1 << 6;
454 const HAS_PROJECTION = 1 << 7;
456 // FIXME: Rename this to the actual property since it's used for generators too
457 const HAS_TY_CLOSURE = 1 << 8;
459 /// `true` if there are "names" of types and regions and so forth
460 /// that are local to a particular fn
461 const HAS_FREE_LOCAL_NAMES = 1 << 9;
463 /// Present if the type belongs in a local type context.
464 /// Only set for Infer other than Fresh.
465 const KEEP_IN_LOCAL_TCX = 1 << 10;
467 /// Does this have any `ReLateBound` regions? Used to check
468 /// if a global bound is safe to evaluate.
469 const HAS_RE_LATE_BOUND = 1 << 11;
471 const HAS_TY_PLACEHOLDER = 1 << 12;
473 const HAS_CT_INFER = 1 << 13;
474 const HAS_CT_PLACEHOLDER = 1 << 14;
476 const NEEDS_SUBST = TypeFlags::HAS_PARAMS.bits |
477 TypeFlags::HAS_RE_EARLY_BOUND.bits;
479 /// Flags representing the nominal content of a type,
480 /// computed by FlagsComputation. If you add a new nominal
481 /// flag, it should be added here too.
482 const NOMINAL_FLAGS = TypeFlags::HAS_PARAMS.bits |
483 TypeFlags::HAS_TY_INFER.bits |
484 TypeFlags::HAS_RE_INFER.bits |
485 TypeFlags::HAS_RE_PLACEHOLDER.bits |
486 TypeFlags::HAS_RE_EARLY_BOUND.bits |
487 TypeFlags::HAS_FREE_REGIONS.bits |
488 TypeFlags::HAS_TY_ERR.bits |
489 TypeFlags::HAS_PROJECTION.bits |
490 TypeFlags::HAS_TY_CLOSURE.bits |
491 TypeFlags::HAS_FREE_LOCAL_NAMES.bits |
492 TypeFlags::KEEP_IN_LOCAL_TCX.bits |
493 TypeFlags::HAS_RE_LATE_BOUND.bits |
494 TypeFlags::HAS_TY_PLACEHOLDER.bits |
495 TypeFlags::HAS_CT_INFER.bits |
496 TypeFlags::HAS_CT_PLACEHOLDER.bits;
500 #[allow(rustc::usage_of_ty_tykind)]
501 pub struct TyS<'tcx> {
502 pub kind: TyKind<'tcx>,
503 pub flags: TypeFlags,
505 /// This is a kind of confusing thing: it stores the smallest
508 /// (a) the binder itself captures nothing but
509 /// (b) all the late-bound things within the type are captured
510 /// by some sub-binder.
512 /// So, for a type without any late-bound things, like `u32`, this
513 /// will be *innermost*, because that is the innermost binder that
514 /// captures nothing. But for a type `&'D u32`, where `'D` is a
515 /// late-bound region with De Bruijn index `D`, this would be `D + 1`
516 /// -- the binder itself does not capture `D`, but `D` is captured
517 /// by an inner binder.
519 /// We call this concept an "exclusive" binder `D` because all
520 /// De Bruijn indices within the type are contained within `0..D`
522 outer_exclusive_binder: ty::DebruijnIndex,
525 // `TyS` is used a lot. Make sure it doesn't unintentionally get bigger.
526 #[cfg(target_arch = "x86_64")]
527 static_assert_size!(TyS<'_>, 32);
529 impl<'tcx> Ord for TyS<'tcx> {
530 fn cmp(&self, other: &TyS<'tcx>) -> Ordering {
531 self.kind.cmp(&other.kind)
535 impl<'tcx> PartialOrd for TyS<'tcx> {
536 fn partial_cmp(&self, other: &TyS<'tcx>) -> Option<Ordering> {
537 Some(self.kind.cmp(&other.kind))
541 impl<'tcx> PartialEq for TyS<'tcx> {
543 fn eq(&self, other: &TyS<'tcx>) -> bool {
547 impl<'tcx> Eq for TyS<'tcx> {}
549 impl<'tcx> Hash for TyS<'tcx> {
550 fn hash<H: Hasher>(&self, s: &mut H) {
551 (self as *const TyS<'_>).hash(s)
555 impl<'tcx> TyS<'tcx> {
556 pub fn is_primitive_ty(&self) -> bool {
563 Infer(InferTy::IntVar(_)) |
564 Infer(InferTy::FloatVar(_)) |
565 Infer(InferTy::FreshIntTy(_)) |
566 Infer(InferTy::FreshFloatTy(_)) => true,
567 Ref(_, x, _) => x.is_primitive_ty(),
572 pub fn is_suggestable(&self) -> bool {
580 Projection(..) => false,
586 impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for ty::TyS<'tcx> {
587 fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
591 // The other fields just provide fast access to information that is
592 // also contained in `kind`, so no need to hash them.
595 outer_exclusive_binder: _,
598 kind.hash_stable(hcx, hasher);
602 #[rustc_diagnostic_item = "Ty"]
603 pub type Ty<'tcx> = &'tcx TyS<'tcx>;
605 impl<'tcx> rustc_serialize::UseSpecializedEncodable for Ty<'tcx> {}
606 impl<'tcx> rustc_serialize::UseSpecializedDecodable for Ty<'tcx> {}
608 pub type CanonicalTy<'tcx> = Canonical<'tcx, Ty<'tcx>>;
611 /// A dummy type used to force `List` to be unsized while not requiring references to it be wide
613 type OpaqueListContents;
616 /// A wrapper for slices with the additional invariant
617 /// that the slice is interned and no other slice with
618 /// the same contents can exist in the same context.
619 /// This means we can use pointer for both
620 /// equality comparisons and hashing.
621 /// Note: `Slice` was already taken by the `Ty`.
626 opaque: OpaqueListContents,
629 unsafe impl<T: Sync> Sync for List<T> {}
631 impl<T: Copy> List<T> {
633 fn from_arena<'tcx>(arena: &'tcx SyncDroplessArena, slice: &[T]) -> &'tcx List<T> {
634 assert!(!mem::needs_drop::<T>());
635 assert!(mem::size_of::<T>() != 0);
636 assert!(slice.len() != 0);
638 // Align up the size of the len (usize) field
639 let align = mem::align_of::<T>();
640 let align_mask = align - 1;
641 let offset = mem::size_of::<usize>();
642 let offset = (offset + align_mask) & !align_mask;
644 let size = offset + slice.len() * mem::size_of::<T>();
646 let mem = arena.alloc_raw(
648 cmp::max(mem::align_of::<T>(), mem::align_of::<usize>()));
650 let result = &mut *(mem.as_mut_ptr() as *mut List<T>);
652 result.len = slice.len();
654 // Write the elements
655 let arena_slice = slice::from_raw_parts_mut(result.data.as_mut_ptr(), result.len);
656 arena_slice.copy_from_slice(slice);
663 impl<T: fmt::Debug> fmt::Debug for List<T> {
664 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
669 impl<T: Encodable> Encodable for List<T> {
671 fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
676 impl<T> Ord for List<T> where T: Ord {
677 fn cmp(&self, other: &List<T>) -> Ordering {
678 if self == other { Ordering::Equal } else {
679 <[T] as Ord>::cmp(&**self, &**other)
684 impl<T> PartialOrd for List<T> where T: PartialOrd {
685 fn partial_cmp(&self, other: &List<T>) -> Option<Ordering> {
686 if self == other { Some(Ordering::Equal) } else {
687 <[T] as PartialOrd>::partial_cmp(&**self, &**other)
692 impl<T: PartialEq> PartialEq for List<T> {
694 fn eq(&self, other: &List<T>) -> bool {
698 impl<T: Eq> Eq for List<T> {}
700 impl<T> Hash for List<T> {
702 fn hash<H: Hasher>(&self, s: &mut H) {
703 (self as *const List<T>).hash(s)
707 impl<T> Deref for List<T> {
710 fn deref(&self) -> &[T] {
715 impl<T> AsRef<[T]> for List<T> {
717 fn as_ref(&self) -> &[T] {
719 slice::from_raw_parts(self.data.as_ptr(), self.len)
724 impl<'a, T> IntoIterator for &'a List<T> {
726 type IntoIter = <&'a [T] as IntoIterator>::IntoIter;
728 fn into_iter(self) -> Self::IntoIter {
733 impl<'tcx> rustc_serialize::UseSpecializedDecodable for &'tcx List<Ty<'tcx>> {}
737 pub fn empty<'a>() -> &'a List<T> {
738 #[repr(align(64), C)]
739 struct EmptySlice([u8; 64]);
740 static EMPTY_SLICE: EmptySlice = EmptySlice([0; 64]);
741 assert!(mem::align_of::<T>() <= 64);
743 &*(&EMPTY_SLICE as *const _ as *const List<T>)
748 #[derive(Clone, Copy, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, HashStable)]
749 pub struct UpvarPath {
750 pub hir_id: hir::HirId,
753 /// Upvars do not get their own `NodeId`. Instead, we use the pair of
754 /// the original var ID (that is, the root variable that is referenced
755 /// by the upvar) and the ID of the closure expression.
756 #[derive(Clone, Copy, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, HashStable)]
758 pub var_path: UpvarPath,
759 pub closure_expr_id: LocalDefId,
762 #[derive(Clone, PartialEq, Debug, RustcEncodable, RustcDecodable, Copy, HashStable)]
763 pub enum BorrowKind {
764 /// Data must be immutable and is aliasable.
767 /// Data must be immutable but not aliasable. This kind of borrow
768 /// cannot currently be expressed by the user and is used only in
769 /// implicit closure bindings. It is needed when the closure
770 /// is borrowing or mutating a mutable referent, e.g.:
772 /// let x: &mut isize = ...;
773 /// let y = || *x += 5;
775 /// If we were to try to translate this closure into a more explicit
776 /// form, we'd encounter an error with the code as written:
778 /// struct Env { x: & &mut isize }
779 /// let x: &mut isize = ...;
780 /// let y = (&mut Env { &x }, fn_ptr); // Closure is pair of env and fn
781 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
783 /// This is then illegal because you cannot mutate a `&mut` found
784 /// in an aliasable location. To solve, you'd have to translate with
785 /// an `&mut` borrow:
787 /// struct Env { x: & &mut isize }
788 /// let x: &mut isize = ...;
789 /// let y = (&mut Env { &mut x }, fn_ptr); // changed from &x to &mut x
790 /// fn fn_ptr(env: &mut Env) { **env.x += 5; }
792 /// Now the assignment to `**env.x` is legal, but creating a
793 /// mutable pointer to `x` is not because `x` is not mutable. We
794 /// could fix this by declaring `x` as `let mut x`. This is ok in
795 /// user code, if awkward, but extra weird for closures, since the
796 /// borrow is hidden.
798 /// So we introduce a "unique imm" borrow -- the referent is
799 /// immutable, but not aliasable. This solves the problem. For
800 /// simplicity, we don't give users the way to express this
801 /// borrow, it's just used when translating closures.
804 /// Data is mutable and not aliasable.
808 /// Information describing the capture of an upvar. This is computed
809 /// during `typeck`, specifically by `regionck`.
810 #[derive(PartialEq, Clone, Debug, Copy, RustcEncodable, RustcDecodable, HashStable)]
811 pub enum UpvarCapture<'tcx> {
812 /// Upvar is captured by value. This is always true when the
813 /// closure is labeled `move`, but can also be true in other cases
814 /// depending on inference.
817 /// Upvar is captured by reference.
818 ByRef(UpvarBorrow<'tcx>),
821 #[derive(PartialEq, Clone, Copy, RustcEncodable, RustcDecodable, HashStable)]
822 pub struct UpvarBorrow<'tcx> {
823 /// The kind of borrow: by-ref upvars have access to shared
824 /// immutable borrows, which are not part of the normal language
826 pub kind: BorrowKind,
828 /// Region of the resulting reference.
829 pub region: ty::Region<'tcx>,
832 pub type UpvarListMap = FxHashMap<DefId, FxIndexMap<hir::HirId, UpvarId>>;
833 pub type UpvarCaptureMap<'tcx> = FxHashMap<UpvarId, UpvarCapture<'tcx>>;
835 #[derive(Copy, Clone, TypeFoldable)]
836 pub struct ClosureUpvar<'tcx> {
842 #[derive(Clone, Copy, PartialEq, Eq)]
843 pub enum IntVarValue {
845 UintType(ast::UintTy),
848 #[derive(Clone, Copy, PartialEq, Eq)]
849 pub struct FloatVarValue(pub ast::FloatTy);
851 impl ty::EarlyBoundRegion {
852 pub fn to_bound_region(&self) -> ty::BoundRegion {
853 ty::BoundRegion::BrNamed(self.def_id, self.name)
856 /// Does this early bound region have a name? Early bound regions normally
857 /// always have names except when using anonymous lifetimes (`'_`).
858 pub fn has_name(&self) -> bool {
859 self.name != kw::UnderscoreLifetime
863 #[derive(Clone, Debug, RustcEncodable, RustcDecodable, HashStable)]
864 pub enum GenericParamDefKind {
868 object_lifetime_default: ObjectLifetimeDefault,
869 synthetic: Option<hir::SyntheticTyParamKind>,
874 #[derive(Clone, RustcEncodable, RustcDecodable, HashStable)]
875 pub struct GenericParamDef {
880 /// `pure_wrt_drop`, set by the (unsafe) `#[may_dangle]` attribute
881 /// on generic parameter `'a`/`T`, asserts data behind the parameter
882 /// `'a`/`T` won't be accessed during the parent type's `Drop` impl.
883 pub pure_wrt_drop: bool,
885 pub kind: GenericParamDefKind,
888 impl GenericParamDef {
889 pub fn to_early_bound_region_data(&self) -> ty::EarlyBoundRegion {
890 if let GenericParamDefKind::Lifetime = self.kind {
891 ty::EarlyBoundRegion {
897 bug!("cannot convert a non-lifetime parameter def to an early bound region")
901 pub fn to_bound_region(&self) -> ty::BoundRegion {
902 if let GenericParamDefKind::Lifetime = self.kind {
903 self.to_early_bound_region_data().to_bound_region()
905 bug!("cannot convert a non-lifetime parameter def to an early bound region")
911 pub struct GenericParamCount {
912 pub lifetimes: usize,
917 /// Information about the formal type/lifetime parameters associated
918 /// with an item or method. Analogous to `hir::Generics`.
920 /// The ordering of parameters is the same as in `Subst` (excluding child generics):
921 /// `Self` (optionally), `Lifetime` params..., `Type` params...
922 #[derive(Clone, Debug, RustcEncodable, RustcDecodable, HashStable)]
923 pub struct Generics {
924 pub parent: Option<DefId>,
925 pub parent_count: usize,
926 pub params: Vec<GenericParamDef>,
928 /// Reverse map to the `index` field of each `GenericParamDef`.
929 #[stable_hasher(ignore)]
930 pub param_def_id_to_index: FxHashMap<DefId, u32>,
933 pub has_late_bound_regions: Option<Span>,
936 impl<'tcx> Generics {
937 pub fn count(&self) -> usize {
938 self.parent_count + self.params.len()
941 pub fn own_counts(&self) -> GenericParamCount {
942 // We could cache this as a property of `GenericParamCount`, but
943 // the aim is to refactor this away entirely eventually and the
944 // presence of this method will be a constant reminder.
945 let mut own_counts: GenericParamCount = Default::default();
947 for param in &self.params {
949 GenericParamDefKind::Lifetime => own_counts.lifetimes += 1,
950 GenericParamDefKind::Type { .. } => own_counts.types += 1,
951 GenericParamDefKind::Const => own_counts.consts += 1,
958 pub fn requires_monomorphization(&self, tcx: TyCtxt<'tcx>) -> bool {
959 if self.own_requires_monomorphization() {
963 if let Some(parent_def_id) = self.parent {
964 let parent = tcx.generics_of(parent_def_id);
965 parent.requires_monomorphization(tcx)
971 pub fn own_requires_monomorphization(&self) -> bool {
972 for param in &self.params {
974 GenericParamDefKind::Type { .. } | GenericParamDefKind::Const => return true,
975 GenericParamDefKind::Lifetime => {}
983 param: &EarlyBoundRegion,
985 ) -> &'tcx GenericParamDef {
986 if let Some(index) = param.index.checked_sub(self.parent_count as u32) {
987 let param = &self.params[index as usize];
989 GenericParamDefKind::Lifetime => param,
990 _ => bug!("expected lifetime parameter, but found another generic parameter")
993 tcx.generics_of(self.parent.expect("parent_count > 0 but no parent?"))
994 .region_param(param, tcx)
998 /// Returns the `GenericParamDef` associated with this `ParamTy`.
999 pub fn type_param(&'tcx self, param: &ParamTy, tcx: TyCtxt<'tcx>) -> &'tcx GenericParamDef {
1000 if let Some(index) = param.index.checked_sub(self.parent_count as u32) {
1001 let param = &self.params[index as usize];
1003 GenericParamDefKind::Type { .. } => param,
1004 _ => bug!("expected type parameter, but found another generic parameter")
1007 tcx.generics_of(self.parent.expect("parent_count > 0 but no parent?"))
1008 .type_param(param, tcx)
1012 /// Returns the `ConstParameterDef` associated with this `ParamConst`.
1013 pub fn const_param(&'tcx self, param: &ParamConst, tcx: TyCtxt<'tcx>) -> &GenericParamDef {
1014 if let Some(index) = param.index.checked_sub(self.parent_count as u32) {
1015 let param = &self.params[index as usize];
1017 GenericParamDefKind::Const => param,
1018 _ => bug!("expected const parameter, but found another generic parameter")
1021 tcx.generics_of(self.parent.expect("parent_count>0 but no parent?"))
1022 .const_param(param, tcx)
1027 /// Bounds on generics.
1028 #[derive(Copy, Clone, Default, Debug, RustcEncodable, RustcDecodable, HashStable)]
1029 pub struct GenericPredicates<'tcx> {
1030 pub parent: Option<DefId>,
1031 pub predicates: &'tcx [(Predicate<'tcx>, Span)],
1034 impl<'tcx> GenericPredicates<'tcx> {
1038 substs: SubstsRef<'tcx>,
1039 ) -> InstantiatedPredicates<'tcx> {
1040 let mut instantiated = InstantiatedPredicates::empty();
1041 self.instantiate_into(tcx, &mut instantiated, substs);
1045 pub fn instantiate_own(
1048 substs: SubstsRef<'tcx>,
1049 ) -> InstantiatedPredicates<'tcx> {
1050 InstantiatedPredicates {
1051 predicates: self.predicates.iter().map(|(p, _)| p.subst(tcx, substs)).collect(),
1055 fn instantiate_into(
1058 instantiated: &mut InstantiatedPredicates<'tcx>,
1059 substs: SubstsRef<'tcx>,
1061 if let Some(def_id) = self.parent {
1062 tcx.predicates_of(def_id).instantiate_into(tcx, instantiated, substs);
1064 instantiated.predicates.extend(
1065 self.predicates.iter().map(|(p, _)| p.subst(tcx, substs)),
1069 pub fn instantiate_identity(&self, tcx: TyCtxt<'tcx>) -> InstantiatedPredicates<'tcx> {
1070 let mut instantiated = InstantiatedPredicates::empty();
1071 self.instantiate_identity_into(tcx, &mut instantiated);
1075 fn instantiate_identity_into(
1078 instantiated: &mut InstantiatedPredicates<'tcx>,
1080 if let Some(def_id) = self.parent {
1081 tcx.predicates_of(def_id).instantiate_identity_into(tcx, instantiated);
1083 instantiated.predicates.extend(self.predicates.iter().map(|&(p, _)| p))
1086 pub fn instantiate_supertrait(
1089 poly_trait_ref: &ty::PolyTraitRef<'tcx>,
1090 ) -> InstantiatedPredicates<'tcx> {
1091 assert_eq!(self.parent, None);
1092 InstantiatedPredicates {
1093 predicates: self.predicates.iter().map(|(pred, _)| {
1094 pred.subst_supertrait(tcx, poly_trait_ref)
1100 #[derive(Clone, Copy, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable,
1101 HashStable, TypeFoldable)]
1102 pub enum Predicate<'tcx> {
1103 /// Corresponds to `where Foo: Bar<A, B, C>`. `Foo` here would be
1104 /// the `Self` type of the trait reference and `A`, `B`, and `C`
1105 /// would be the type parameters.
1106 Trait(PolyTraitPredicate<'tcx>),
1109 RegionOutlives(PolyRegionOutlivesPredicate<'tcx>),
1112 TypeOutlives(PolyTypeOutlivesPredicate<'tcx>),
1114 /// `where <T as TraitRef>::Name == X`, approximately.
1115 /// See the `ProjectionPredicate` struct for details.
1116 Projection(PolyProjectionPredicate<'tcx>),
1118 /// No syntax: `T` well-formed.
1119 WellFormed(Ty<'tcx>),
1121 /// Trait must be object-safe.
1124 /// No direct syntax. May be thought of as `where T: FnFoo<...>`
1125 /// for some substitutions `...` and `T` being a closure type.
1126 /// Satisfied (or refuted) once we know the closure's kind.
1127 ClosureKind(DefId, SubstsRef<'tcx>, ClosureKind),
1130 Subtype(PolySubtypePredicate<'tcx>),
1132 /// Constant initializer must evaluate successfully.
1133 ConstEvaluatable(DefId, SubstsRef<'tcx>),
1136 /// The crate outlives map is computed during typeck and contains the
1137 /// outlives of every item in the local crate. You should not use it
1138 /// directly, because to do so will make your pass dependent on the
1139 /// HIR of every item in the local crate. Instead, use
1140 /// `tcx.inferred_outlives_of()` to get the outlives for a *particular*
1142 #[derive(HashStable)]
1143 pub struct CratePredicatesMap<'tcx> {
1144 /// For each struct with outlive bounds, maps to a vector of the
1145 /// predicate of its outlive bounds. If an item has no outlives
1146 /// bounds, it will have no entry.
1147 pub predicates: FxHashMap<DefId, &'tcx [(ty::Predicate<'tcx>, Span)]>,
1150 impl<'tcx> AsRef<Predicate<'tcx>> for Predicate<'tcx> {
1151 fn as_ref(&self) -> &Predicate<'tcx> {
1156 impl<'tcx> Predicate<'tcx> {
1157 /// Performs a substitution suitable for going from a
1158 /// poly-trait-ref to supertraits that must hold if that
1159 /// poly-trait-ref holds. This is slightly different from a normal
1160 /// substitution in terms of what happens with bound regions. See
1161 /// lengthy comment below for details.
1162 pub fn subst_supertrait(
1165 trait_ref: &ty::PolyTraitRef<'tcx>,
1166 ) -> ty::Predicate<'tcx> {
1167 // The interaction between HRTB and supertraits is not entirely
1168 // obvious. Let me walk you (and myself) through an example.
1170 // Let's start with an easy case. Consider two traits:
1172 // trait Foo<'a>: Bar<'a,'a> { }
1173 // trait Bar<'b,'c> { }
1175 // Now, if we have a trait reference `for<'x> T: Foo<'x>`, then
1176 // we can deduce that `for<'x> T: Bar<'x,'x>`. Basically, if we
1177 // knew that `Foo<'x>` (for any 'x) then we also know that
1178 // `Bar<'x,'x>` (for any 'x). This more-or-less falls out from
1179 // normal substitution.
1181 // In terms of why this is sound, the idea is that whenever there
1182 // is an impl of `T:Foo<'a>`, it must show that `T:Bar<'a,'a>`
1183 // holds. So if there is an impl of `T:Foo<'a>` that applies to
1184 // all `'a`, then we must know that `T:Bar<'a,'a>` holds for all
1187 // Another example to be careful of is this:
1189 // trait Foo1<'a>: for<'b> Bar1<'a,'b> { }
1190 // trait Bar1<'b,'c> { }
1192 // Here, if we have `for<'x> T: Foo1<'x>`, then what do we know?
1193 // The answer is that we know `for<'x,'b> T: Bar1<'x,'b>`. The
1194 // reason is similar to the previous example: any impl of
1195 // `T:Foo1<'x>` must show that `for<'b> T: Bar1<'x, 'b>`. So
1196 // basically we would want to collapse the bound lifetimes from
1197 // the input (`trait_ref`) and the supertraits.
1199 // To achieve this in practice is fairly straightforward. Let's
1200 // consider the more complicated scenario:
1202 // - We start out with `for<'x> T: Foo1<'x>`. In this case, `'x`
1203 // has a De Bruijn index of 1. We want to produce `for<'x,'b> T: Bar1<'x,'b>`,
1204 // where both `'x` and `'b` would have a DB index of 1.
1205 // The substitution from the input trait-ref is therefore going to be
1206 // `'a => 'x` (where `'x` has a DB index of 1).
1207 // - The super-trait-ref is `for<'b> Bar1<'a,'b>`, where `'a` is an
1208 // early-bound parameter and `'b' is a late-bound parameter with a
1210 // - If we replace `'a` with `'x` from the input, it too will have
1211 // a DB index of 1, and thus we'll have `for<'x,'b> Bar1<'x,'b>`
1212 // just as we wanted.
1214 // There is only one catch. If we just apply the substitution `'a
1215 // => 'x` to `for<'b> Bar1<'a,'b>`, the substitution code will
1216 // adjust the DB index because we substituting into a binder (it
1217 // tries to be so smart...) resulting in `for<'x> for<'b>
1218 // Bar1<'x,'b>` (we have no syntax for this, so use your
1219 // imagination). Basically the 'x will have DB index of 2 and 'b
1220 // will have DB index of 1. Not quite what we want. So we apply
1221 // the substitution to the *contents* of the trait reference,
1222 // rather than the trait reference itself (put another way, the
1223 // substitution code expects equal binding levels in the values
1224 // from the substitution and the value being substituted into, and
1225 // this trick achieves that).
1227 let substs = &trait_ref.skip_binder().substs;
1229 Predicate::Trait(ref binder) =>
1230 Predicate::Trait(binder.map_bound(|data| data.subst(tcx, substs))),
1231 Predicate::Subtype(ref binder) =>
1232 Predicate::Subtype(binder.map_bound(|data| data.subst(tcx, substs))),
1233 Predicate::RegionOutlives(ref binder) =>
1234 Predicate::RegionOutlives(binder.map_bound(|data| data.subst(tcx, substs))),
1235 Predicate::TypeOutlives(ref binder) =>
1236 Predicate::TypeOutlives(binder.map_bound(|data| data.subst(tcx, substs))),
1237 Predicate::Projection(ref binder) =>
1238 Predicate::Projection(binder.map_bound(|data| data.subst(tcx, substs))),
1239 Predicate::WellFormed(data) =>
1240 Predicate::WellFormed(data.subst(tcx, substs)),
1241 Predicate::ObjectSafe(trait_def_id) =>
1242 Predicate::ObjectSafe(trait_def_id),
1243 Predicate::ClosureKind(closure_def_id, closure_substs, kind) =>
1244 Predicate::ClosureKind(closure_def_id, closure_substs.subst(tcx, substs), kind),
1245 Predicate::ConstEvaluatable(def_id, const_substs) =>
1246 Predicate::ConstEvaluatable(def_id, const_substs.subst(tcx, substs)),
1251 #[derive(Clone, Copy, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable,
1252 HashStable, TypeFoldable)]
1253 pub struct TraitPredicate<'tcx> {
1254 pub trait_ref: TraitRef<'tcx>
1257 pub type PolyTraitPredicate<'tcx> = ty::Binder<TraitPredicate<'tcx>>;
1259 impl<'tcx> TraitPredicate<'tcx> {
1260 pub fn def_id(&self) -> DefId {
1261 self.trait_ref.def_id
1264 pub fn input_types<'a>(&'a self) -> impl DoubleEndedIterator<Item = Ty<'tcx>> + 'a {
1265 self.trait_ref.input_types()
1268 pub fn self_ty(&self) -> Ty<'tcx> {
1269 self.trait_ref.self_ty()
1273 impl<'tcx> PolyTraitPredicate<'tcx> {
1274 pub fn def_id(&self) -> DefId {
1275 // Ok to skip binder since trait `DefId` does not care about regions.
1276 self.skip_binder().def_id()
1280 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord,
1281 Hash, Debug, RustcEncodable, RustcDecodable, HashStable, TypeFoldable)]
1282 pub struct OutlivesPredicate<A, B>(pub A, pub B); // `A: B`
1283 pub type PolyOutlivesPredicate<A, B> = ty::Binder<OutlivesPredicate<A, B>>;
1284 pub type RegionOutlivesPredicate<'tcx> = OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>;
1285 pub type TypeOutlivesPredicate<'tcx> = OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>>;
1286 pub type PolyRegionOutlivesPredicate<'tcx> = ty::Binder<RegionOutlivesPredicate<'tcx>>;
1287 pub type PolyTypeOutlivesPredicate<'tcx> = ty::Binder<TypeOutlivesPredicate<'tcx>>;
1289 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug, RustcEncodable, RustcDecodable,
1290 HashStable, TypeFoldable)]
1291 pub struct SubtypePredicate<'tcx> {
1292 pub a_is_expected: bool,
1296 pub type PolySubtypePredicate<'tcx> = ty::Binder<SubtypePredicate<'tcx>>;
1298 /// This kind of predicate has no *direct* correspondent in the
1299 /// syntax, but it roughly corresponds to the syntactic forms:
1301 /// 1. `T: TraitRef<..., Item = Type>`
1302 /// 2. `<T as TraitRef<...>>::Item == Type` (NYI)
1304 /// In particular, form #1 is "desugared" to the combination of a
1305 /// normal trait predicate (`T: TraitRef<...>`) and one of these
1306 /// predicates. Form #2 is a broader form in that it also permits
1307 /// equality between arbitrary types. Processing an instance of
1308 /// Form #2 eventually yields one of these `ProjectionPredicate`
1309 /// instances to normalize the LHS.
1310 #[derive(Copy, Clone, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable,
1311 HashStable, TypeFoldable)]
1312 pub struct ProjectionPredicate<'tcx> {
1313 pub projection_ty: ProjectionTy<'tcx>,
1317 pub type PolyProjectionPredicate<'tcx> = Binder<ProjectionPredicate<'tcx>>;
1319 impl<'tcx> PolyProjectionPredicate<'tcx> {
1320 /// Returns the `DefId` of the associated item being projected.
1321 pub fn item_def_id(&self) -> DefId {
1322 self.skip_binder().projection_ty.item_def_id
1326 pub fn to_poly_trait_ref(&self, tcx: TyCtxt<'_>) -> PolyTraitRef<'tcx> {
1327 // Note: unlike with `TraitRef::to_poly_trait_ref()`,
1328 // `self.0.trait_ref` is permitted to have escaping regions.
1329 // This is because here `self` has a `Binder` and so does our
1330 // return value, so we are preserving the number of binding
1332 self.map_bound(|predicate| predicate.projection_ty.trait_ref(tcx))
1335 pub fn ty(&self) -> Binder<Ty<'tcx>> {
1336 self.map_bound(|predicate| predicate.ty)
1339 /// The `DefId` of the `TraitItem` for the associated type.
1341 /// Note that this is not the `DefId` of the `TraitRef` containing this
1342 /// associated type, which is in `tcx.associated_item(projection_def_id()).container`.
1343 pub fn projection_def_id(&self) -> DefId {
1344 // Ok to skip binder since trait `DefId` does not care about regions.
1345 self.skip_binder().projection_ty.item_def_id
1349 pub trait ToPolyTraitRef<'tcx> {
1350 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx>;
1353 impl<'tcx> ToPolyTraitRef<'tcx> for TraitRef<'tcx> {
1354 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1355 ty::Binder::dummy(self.clone())
1359 impl<'tcx> ToPolyTraitRef<'tcx> for PolyTraitPredicate<'tcx> {
1360 fn to_poly_trait_ref(&self) -> PolyTraitRef<'tcx> {
1361 self.map_bound_ref(|trait_pred| trait_pred.trait_ref)
1365 pub trait ToPredicate<'tcx> {
1366 fn to_predicate(&self) -> Predicate<'tcx>;
1369 impl<'tcx> ToPredicate<'tcx> for TraitRef<'tcx> {
1370 fn to_predicate(&self) -> Predicate<'tcx> {
1371 ty::Predicate::Trait(ty::Binder::dummy(ty::TraitPredicate {
1372 trait_ref: self.clone()
1377 impl<'tcx> ToPredicate<'tcx> for PolyTraitRef<'tcx> {
1378 fn to_predicate(&self) -> Predicate<'tcx> {
1379 ty::Predicate::Trait(self.to_poly_trait_predicate())
1383 impl<'tcx> ToPredicate<'tcx> for PolyRegionOutlivesPredicate<'tcx> {
1384 fn to_predicate(&self) -> Predicate<'tcx> {
1385 Predicate::RegionOutlives(self.clone())
1389 impl<'tcx> ToPredicate<'tcx> for PolyTypeOutlivesPredicate<'tcx> {
1390 fn to_predicate(&self) -> Predicate<'tcx> {
1391 Predicate::TypeOutlives(self.clone())
1395 impl<'tcx> ToPredicate<'tcx> for PolyProjectionPredicate<'tcx> {
1396 fn to_predicate(&self) -> Predicate<'tcx> {
1397 Predicate::Projection(self.clone())
1401 // A custom iterator used by `Predicate::walk_tys`.
1402 enum WalkTysIter<'tcx, I, J, K>
1403 where I: Iterator<Item = Ty<'tcx>>,
1404 J: Iterator<Item = Ty<'tcx>>,
1405 K: Iterator<Item = Ty<'tcx>>
1409 Two(Ty<'tcx>, Ty<'tcx>),
1415 impl<'tcx, I, J, K> Iterator for WalkTysIter<'tcx, I, J, K>
1416 where I: Iterator<Item = Ty<'tcx>>,
1417 J: Iterator<Item = Ty<'tcx>>,
1418 K: Iterator<Item = Ty<'tcx>>
1420 type Item = Ty<'tcx>;
1422 fn next(&mut self) -> Option<Ty<'tcx>> {
1424 WalkTysIter::None => None,
1425 WalkTysIter::One(item) => {
1426 *self = WalkTysIter::None;
1429 WalkTysIter::Two(item1, item2) => {
1430 *self = WalkTysIter::One(item2);
1433 WalkTysIter::Types(ref mut iter) => {
1436 WalkTysIter::InputTypes(ref mut iter) => {
1439 WalkTysIter::ProjectionTypes(ref mut iter) => {
1446 impl<'tcx> Predicate<'tcx> {
1447 /// Iterates over the types in this predicate. Note that in all
1448 /// cases this is skipping over a binder, so late-bound regions
1449 /// with depth 0 are bound by the predicate.
1450 pub fn walk_tys(&'a self) -> impl Iterator<Item = Ty<'tcx>> + 'a {
1452 ty::Predicate::Trait(ref data) => {
1453 WalkTysIter::InputTypes(data.skip_binder().input_types())
1455 ty::Predicate::Subtype(binder) => {
1456 let SubtypePredicate { a, b, a_is_expected: _ } = binder.skip_binder();
1457 WalkTysIter::Two(a, b)
1459 ty::Predicate::TypeOutlives(binder) => {
1460 WalkTysIter::One(binder.skip_binder().0)
1462 ty::Predicate::RegionOutlives(..) => {
1465 ty::Predicate::Projection(ref data) => {
1466 let inner = data.skip_binder();
1467 WalkTysIter::ProjectionTypes(
1468 inner.projection_ty.substs.types().chain(Some(inner.ty)))
1470 ty::Predicate::WellFormed(data) => {
1471 WalkTysIter::One(data)
1473 ty::Predicate::ObjectSafe(_trait_def_id) => {
1476 ty::Predicate::ClosureKind(_closure_def_id, closure_substs, _kind) => {
1477 WalkTysIter::Types(closure_substs.types())
1479 ty::Predicate::ConstEvaluatable(_, substs) => {
1480 WalkTysIter::Types(substs.types())
1485 pub fn to_opt_poly_trait_ref(&self) -> Option<PolyTraitRef<'tcx>> {
1487 Predicate::Trait(ref t) => {
1488 Some(t.to_poly_trait_ref())
1490 Predicate::Projection(..) |
1491 Predicate::Subtype(..) |
1492 Predicate::RegionOutlives(..) |
1493 Predicate::WellFormed(..) |
1494 Predicate::ObjectSafe(..) |
1495 Predicate::ClosureKind(..) |
1496 Predicate::TypeOutlives(..) |
1497 Predicate::ConstEvaluatable(..) => {
1503 pub fn to_opt_type_outlives(&self) -> Option<PolyTypeOutlivesPredicate<'tcx>> {
1505 Predicate::TypeOutlives(data) => {
1508 Predicate::Trait(..) |
1509 Predicate::Projection(..) |
1510 Predicate::Subtype(..) |
1511 Predicate::RegionOutlives(..) |
1512 Predicate::WellFormed(..) |
1513 Predicate::ObjectSafe(..) |
1514 Predicate::ClosureKind(..) |
1515 Predicate::ConstEvaluatable(..) => {
1522 /// Represents the bounds declared on a particular set of type
1523 /// parameters. Should eventually be generalized into a flag list of
1524 /// where-clauses. You can obtain a `InstantiatedPredicates` list from a
1525 /// `GenericPredicates` by using the `instantiate` method. Note that this method
1526 /// reflects an important semantic invariant of `InstantiatedPredicates`: while
1527 /// the `GenericPredicates` are expressed in terms of the bound type
1528 /// parameters of the impl/trait/whatever, an `InstantiatedPredicates` instance
1529 /// represented a set of bounds for some particular instantiation,
1530 /// meaning that the generic parameters have been substituted with
1535 /// struct Foo<T, U: Bar<T>> { ... }
1537 /// Here, the `GenericPredicates` for `Foo` would contain a list of bounds like
1538 /// `[[], [U:Bar<T>]]`. Now if there were some particular reference
1539 /// like `Foo<isize,usize>`, then the `InstantiatedPredicates` would be `[[],
1540 /// [usize:Bar<isize>]]`.
1541 #[derive(Clone, Debug, TypeFoldable)]
1542 pub struct InstantiatedPredicates<'tcx> {
1543 pub predicates: Vec<Predicate<'tcx>>,
1546 impl<'tcx> InstantiatedPredicates<'tcx> {
1547 pub fn empty() -> InstantiatedPredicates<'tcx> {
1548 InstantiatedPredicates { predicates: vec![] }
1551 pub fn is_empty(&self) -> bool {
1552 self.predicates.is_empty()
1556 rustc_index::newtype_index! {
1557 /// "Universes" are used during type- and trait-checking in the
1558 /// presence of `for<..>` binders to control what sets of names are
1559 /// visible. Universes are arranged into a tree: the root universe
1560 /// contains names that are always visible. Each child then adds a new
1561 /// set of names that are visible, in addition to those of its parent.
1562 /// We say that the child universe "extends" the parent universe with
1565 /// To make this more concrete, consider this program:
1569 /// fn bar<T>(x: T) {
1570 /// let y: for<'a> fn(&'a u8, Foo) = ...;
1574 /// The struct name `Foo` is in the root universe U0. But the type
1575 /// parameter `T`, introduced on `bar`, is in an extended universe U1
1576 /// -- i.e., within `bar`, we can name both `T` and `Foo`, but outside
1577 /// of `bar`, we cannot name `T`. Then, within the type of `y`, the
1578 /// region `'a` is in a universe U2 that extends U1, because we can
1579 /// name it inside the fn type but not outside.
1581 /// Universes are used to do type- and trait-checking around these
1582 /// "forall" binders (also called **universal quantification**). The
1583 /// idea is that when, in the body of `bar`, we refer to `T` as a
1584 /// type, we aren't referring to any type in particular, but rather a
1585 /// kind of "fresh" type that is distinct from all other types we have
1586 /// actually declared. This is called a **placeholder** type, and we
1587 /// use universes to talk about this. In other words, a type name in
1588 /// universe 0 always corresponds to some "ground" type that the user
1589 /// declared, but a type name in a non-zero universe is a placeholder
1590 /// type -- an idealized representative of "types in general" that we
1591 /// use for checking generic functions.
1592 pub struct UniverseIndex {
1593 DEBUG_FORMAT = "U{}",
1597 impl_stable_hash_for!(struct UniverseIndex { private });
1599 impl UniverseIndex {
1600 pub const ROOT: UniverseIndex = UniverseIndex::from_u32_const(0);
1602 /// Returns the "next" universe index in order -- this new index
1603 /// is considered to extend all previous universes. This
1604 /// corresponds to entering a `forall` quantifier. So, for
1605 /// example, suppose we have this type in universe `U`:
1608 /// for<'a> fn(&'a u32)
1611 /// Once we "enter" into this `for<'a>` quantifier, we are in a
1612 /// new universe that extends `U` -- in this new universe, we can
1613 /// name the region `'a`, but that region was not nameable from
1614 /// `U` because it was not in scope there.
1615 pub fn next_universe(self) -> UniverseIndex {
1616 UniverseIndex::from_u32(self.private.checked_add(1).unwrap())
1619 /// Returns `true` if `self` can name a name from `other` -- in other words,
1620 /// if the set of names in `self` is a superset of those in
1621 /// `other` (`self >= other`).
1622 pub fn can_name(self, other: UniverseIndex) -> bool {
1623 self.private >= other.private
1626 /// Returns `true` if `self` cannot name some names from `other` -- in other
1627 /// words, if the set of names in `self` is a strict subset of
1628 /// those in `other` (`self < other`).
1629 pub fn cannot_name(self, other: UniverseIndex) -> bool {
1630 self.private < other.private
1634 /// The "placeholder index" fully defines a placeholder region.
1635 /// Placeholder regions are identified by both a **universe** as well
1636 /// as a "bound-region" within that universe. The `bound_region` is
1637 /// basically a name -- distinct bound regions within the same
1638 /// universe are just two regions with an unknown relationship to one
1640 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, PartialOrd, Ord)]
1641 pub struct Placeholder<T> {
1642 pub universe: UniverseIndex,
1646 impl<'a, T> HashStable<StableHashingContext<'a>> for Placeholder<T>
1648 T: HashStable<StableHashingContext<'a>>,
1650 fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
1651 self.universe.hash_stable(hcx, hasher);
1652 self.name.hash_stable(hcx, hasher);
1656 pub type PlaceholderRegion = Placeholder<BoundRegion>;
1658 pub type PlaceholderType = Placeholder<BoundVar>;
1660 pub type PlaceholderConst = Placeholder<BoundVar>;
1662 /// When type checking, we use the `ParamEnv` to track
1663 /// details about the set of where-clauses that are in scope at this
1664 /// particular point.
1665 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, HashStable, TypeFoldable)]
1666 pub struct ParamEnv<'tcx> {
1667 /// `Obligation`s that the caller must satisfy. This is basically
1668 /// the set of bounds on the in-scope type parameters, translated
1669 /// into `Obligation`s, and elaborated and normalized.
1670 pub caller_bounds: &'tcx List<ty::Predicate<'tcx>>,
1672 /// Typically, this is `Reveal::UserFacing`, but during codegen we
1673 /// want `Reveal::All` -- note that this is always paired with an
1674 /// empty environment. To get that, use `ParamEnv::reveal()`.
1675 pub reveal: traits::Reveal,
1677 /// If this `ParamEnv` comes from a call to `tcx.param_env(def_id)`,
1678 /// register that `def_id` (useful for transitioning to the chalk trait
1680 pub def_id: Option<DefId>,
1683 impl<'tcx> ParamEnv<'tcx> {
1684 /// Construct a trait environment suitable for contexts where
1685 /// there are no where-clauses in scope. Hidden types (like `impl
1686 /// Trait`) are left hidden, so this is suitable for ordinary
1689 pub fn empty() -> Self {
1690 Self::new(List::empty(), Reveal::UserFacing, None)
1693 /// Construct a trait environment with no where-clauses in scope
1694 /// where the values of all `impl Trait` and other hidden types
1695 /// are revealed. This is suitable for monomorphized, post-typeck
1696 /// environments like codegen or doing optimizations.
1698 /// N.B., if you want to have predicates in scope, use `ParamEnv::new`,
1699 /// or invoke `param_env.with_reveal_all()`.
1701 pub fn reveal_all() -> Self {
1702 Self::new(List::empty(), Reveal::All, None)
1705 /// Construct a trait environment with the given set of predicates.
1708 caller_bounds: &'tcx List<ty::Predicate<'tcx>>,
1710 def_id: Option<DefId>
1712 ty::ParamEnv { caller_bounds, reveal, def_id }
1715 /// Returns a new parameter environment with the same clauses, but
1716 /// which "reveals" the true results of projections in all cases
1717 /// (even for associated types that are specializable). This is
1718 /// the desired behavior during codegen and certain other special
1719 /// contexts; normally though we want to use `Reveal::UserFacing`,
1720 /// which is the default.
1721 pub fn with_reveal_all(self) -> Self {
1722 ty::ParamEnv { reveal: Reveal::All, ..self }
1725 /// Returns this same environment but with no caller bounds.
1726 pub fn without_caller_bounds(self) -> Self {
1727 ty::ParamEnv { caller_bounds: List::empty(), ..self }
1730 /// Creates a suitable environment in which to perform trait
1731 /// queries on the given value. When type-checking, this is simply
1732 /// the pair of the environment plus value. But when reveal is set to
1733 /// All, then if `value` does not reference any type parameters, we will
1734 /// pair it with the empty environment. This improves caching and is generally
1737 /// N.B., we preserve the environment when type-checking because it
1738 /// is possible for the user to have wacky where-clauses like
1739 /// `where Box<u32>: Copy`, which are clearly never
1740 /// satisfiable. We generally want to behave as if they were true,
1741 /// although the surrounding function is never reachable.
1742 pub fn and<T: TypeFoldable<'tcx>>(self, value: T) -> ParamEnvAnd<'tcx, T> {
1744 Reveal::UserFacing => {
1752 if value.has_placeholders()
1753 || value.needs_infer()
1754 || value.has_param_types()
1762 param_env: self.without_caller_bounds(),
1771 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, TypeFoldable)]
1772 pub struct ParamEnvAnd<'tcx, T> {
1773 pub param_env: ParamEnv<'tcx>,
1777 impl<'tcx, T> ParamEnvAnd<'tcx, T> {
1778 pub fn into_parts(self) -> (ParamEnv<'tcx>, T) {
1779 (self.param_env, self.value)
1783 impl<'a, 'tcx, T> HashStable<StableHashingContext<'a>> for ParamEnvAnd<'tcx, T>
1785 T: HashStable<StableHashingContext<'a>>,
1787 fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
1793 param_env.hash_stable(hcx, hasher);
1794 value.hash_stable(hcx, hasher);
1798 #[derive(Copy, Clone, Debug, HashStable)]
1799 pub struct Destructor {
1800 /// The `DefId` of the destructor method
1805 #[derive(HashStable)]
1806 pub struct AdtFlags: u32 {
1807 const NO_ADT_FLAGS = 0;
1808 /// Indicates whether the ADT is an enum.
1809 const IS_ENUM = 1 << 0;
1810 /// Indicates whether the ADT is a union.
1811 const IS_UNION = 1 << 1;
1812 /// Indicates whether the ADT is a struct.
1813 const IS_STRUCT = 1 << 2;
1814 /// Indicates whether the ADT is a struct and has a constructor.
1815 const HAS_CTOR = 1 << 3;
1816 /// Indicates whether the type is a `PhantomData`.
1817 const IS_PHANTOM_DATA = 1 << 4;
1818 /// Indicates whether the type has a `#[fundamental]` attribute.
1819 const IS_FUNDAMENTAL = 1 << 5;
1820 /// Indicates whether the type is a `Box`.
1821 const IS_BOX = 1 << 6;
1822 /// Indicates whether the type is an `Arc`.
1823 const IS_ARC = 1 << 7;
1824 /// Indicates whether the type is an `Rc`.
1825 const IS_RC = 1 << 8;
1826 /// Indicates whether the variant list of this ADT is `#[non_exhaustive]`.
1827 /// (i.e., this flag is never set unless this ADT is an enum).
1828 const IS_VARIANT_LIST_NON_EXHAUSTIVE = 1 << 9;
1833 #[derive(HashStable)]
1834 pub struct VariantFlags: u32 {
1835 const NO_VARIANT_FLAGS = 0;
1836 /// Indicates whether the field list of this variant is `#[non_exhaustive]`.
1837 const IS_FIELD_LIST_NON_EXHAUSTIVE = 1 << 0;
1841 /// Definition of a variant -- a struct's fields or a enum variant.
1843 pub struct VariantDef {
1844 /// `DefId` that identifies the variant itself.
1845 /// If this variant belongs to a struct or union, then this is a copy of its `DefId`.
1847 /// `DefId` that identifies the variant's constructor.
1848 /// If this variant is a struct variant, then this is `None`.
1849 pub ctor_def_id: Option<DefId>,
1850 /// Variant or struct name.
1852 /// Discriminant of this variant.
1853 pub discr: VariantDiscr,
1854 /// Fields of this variant.
1855 pub fields: Vec<FieldDef>,
1856 /// Type of constructor of variant.
1857 pub ctor_kind: CtorKind,
1858 /// Flags of the variant (e.g. is field list non-exhaustive)?
1859 flags: VariantFlags,
1860 /// Variant is obtained as part of recovering from a syntactic error.
1861 /// May be incomplete or bogus.
1862 pub recovered: bool,
1865 impl<'tcx> VariantDef {
1866 /// Creates a new `VariantDef`.
1868 /// `variant_did` is the `DefId` that identifies the enum variant (if this `VariantDef`
1869 /// represents an enum variant).
1871 /// `ctor_did` is the `DefId` that identifies the constructor of unit or
1872 /// tuple-variants/structs. If this is a `struct`-variant then this should be `None`.
1874 /// `parent_did` is the `DefId` of the `AdtDef` representing the enum or struct that
1875 /// owns this variant. It is used for checking if a struct has `#[non_exhaustive]` w/out having
1876 /// to go through the redirect of checking the ctor's attributes - but compiling a small crate
1877 /// requires loading the `AdtDef`s for all the structs in the universe (e.g., coherence for any
1878 /// built-in trait), and we do not want to load attributes twice.
1880 /// If someone speeds up attribute loading to not be a performance concern, they can
1881 /// remove this hack and use the constructor `DefId` everywhere.
1885 variant_did: Option<DefId>,
1886 ctor_def_id: Option<DefId>,
1887 discr: VariantDiscr,
1888 fields: Vec<FieldDef>,
1889 ctor_kind: CtorKind,
1895 "VariantDef::new(ident = {:?}, variant_did = {:?}, ctor_def_id = {:?}, discr = {:?},
1896 fields = {:?}, ctor_kind = {:?}, adt_kind = {:?}, parent_did = {:?})",
1897 ident, variant_did, ctor_def_id, discr, fields, ctor_kind, adt_kind, parent_did,
1900 let mut flags = VariantFlags::NO_VARIANT_FLAGS;
1901 if adt_kind == AdtKind::Struct && tcx.has_attr(parent_did, sym::non_exhaustive) {
1902 debug!("found non-exhaustive field list for {:?}", parent_did);
1903 flags = flags | VariantFlags::IS_FIELD_LIST_NON_EXHAUSTIVE;
1904 } else if let Some(variant_did) = variant_did {
1905 if tcx.has_attr(variant_did, sym::non_exhaustive) {
1906 debug!("found non-exhaustive field list for {:?}", variant_did);
1907 flags = flags | VariantFlags::IS_FIELD_LIST_NON_EXHAUSTIVE;
1912 def_id: variant_did.unwrap_or(parent_did),
1923 /// Is this field list non-exhaustive?
1925 pub fn is_field_list_non_exhaustive(&self) -> bool {
1926 self.flags.intersects(VariantFlags::IS_FIELD_LIST_NON_EXHAUSTIVE)
1930 impl_stable_hash_for!(struct VariantDef {
1933 ident -> (ident.name),
1941 #[derive(Copy, Clone, Debug, PartialEq, Eq, RustcEncodable, RustcDecodable, HashStable)]
1942 pub enum VariantDiscr {
1943 /// Explicit value for this variant, i.e., `X = 123`.
1944 /// The `DefId` corresponds to the embedded constant.
1947 /// The previous variant's discriminant plus one.
1948 /// For efficiency reasons, the distance from the
1949 /// last `Explicit` discriminant is being stored,
1950 /// or `0` for the first variant, if it has none.
1954 #[derive(Debug, HashStable)]
1955 pub struct FieldDef {
1957 #[stable_hasher(project(name))]
1959 pub vis: Visibility,
1962 /// The definition of a user-defined type, e.g., a `struct`, `enum`, or `union`.
1964 /// These are all interned (by `intern_adt_def`) into the `adt_defs` table.
1966 /// The initialism *"Adt"* stands for an [*algebraic data type (ADT)*][adt].
1967 /// This is slightly wrong because `union`s are not ADTs.
1968 /// Moreover, Rust only allows recursive data types through indirection.
1970 /// [adt]: https://en.wikipedia.org/wiki/Algebraic_data_type
1972 /// `DefId` of the struct, enum or union item.
1974 /// Variants of the ADT. If this is a struct or union, then there will be a single variant.
1975 pub variants: IndexVec<self::layout::VariantIdx, VariantDef>,
1976 /// Flags of the ADT (e.g. is this a struct? is this non-exhaustive?)
1978 /// Repr options provided by the user.
1979 pub repr: ReprOptions,
1982 impl PartialOrd for AdtDef {
1983 fn partial_cmp(&self, other: &AdtDef) -> Option<Ordering> {
1984 Some(self.cmp(&other))
1988 /// There should be only one AdtDef for each `did`, therefore
1989 /// it is fine to implement `Ord` only based on `did`.
1990 impl Ord for AdtDef {
1991 fn cmp(&self, other: &AdtDef) -> Ordering {
1992 self.did.cmp(&other.did)
1996 impl PartialEq for AdtDef {
1997 // AdtDef are always interned and this is part of TyS equality
1999 fn eq(&self, other: &Self) -> bool { ptr::eq(self, other) }
2002 impl Eq for AdtDef {}
2004 impl Hash for AdtDef {
2006 fn hash<H: Hasher>(&self, s: &mut H) {
2007 (self as *const AdtDef).hash(s)
2011 impl<'tcx> rustc_serialize::UseSpecializedEncodable for &'tcx AdtDef {
2012 fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
2017 impl<'tcx> rustc_serialize::UseSpecializedDecodable for &'tcx AdtDef {}
2020 impl<'a> HashStable<StableHashingContext<'a>> for AdtDef {
2021 fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) {
2023 static CACHE: RefCell<FxHashMap<usize, Fingerprint>> = Default::default();
2026 let hash: Fingerprint = CACHE.with(|cache| {
2027 let addr = self as *const AdtDef as usize;
2028 *cache.borrow_mut().entry(addr).or_insert_with(|| {
2036 let mut hasher = StableHasher::new();
2037 did.hash_stable(hcx, &mut hasher);
2038 variants.hash_stable(hcx, &mut hasher);
2039 flags.hash_stable(hcx, &mut hasher);
2040 repr.hash_stable(hcx, &mut hasher);
2046 hash.hash_stable(hcx, hasher);
2050 #[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
2051 pub enum AdtKind { Struct, Union, Enum }
2053 impl Into<DataTypeKind> for AdtKind {
2054 fn into(self) -> DataTypeKind {
2056 AdtKind::Struct => DataTypeKind::Struct,
2057 AdtKind::Union => DataTypeKind::Union,
2058 AdtKind::Enum => DataTypeKind::Enum,
2064 #[derive(RustcEncodable, RustcDecodable, Default)]
2065 pub struct ReprFlags: u8 {
2066 const IS_C = 1 << 0;
2067 const IS_SIMD = 1 << 1;
2068 const IS_TRANSPARENT = 1 << 2;
2069 // Internal only for now. If true, don't reorder fields.
2070 const IS_LINEAR = 1 << 3;
2072 // Any of these flags being set prevent field reordering optimisation.
2073 const IS_UNOPTIMISABLE = ReprFlags::IS_C.bits |
2074 ReprFlags::IS_SIMD.bits |
2075 ReprFlags::IS_LINEAR.bits;
2079 impl_stable_hash_for!(struct ReprFlags {
2083 /// Represents the repr options provided by the user,
2084 #[derive(Copy, Clone, Debug, Eq, PartialEq, RustcEncodable, RustcDecodable, Default)]
2085 pub struct ReprOptions {
2086 pub int: Option<attr::IntType>,
2087 pub align: Option<Align>,
2088 pub pack: Option<Align>,
2089 pub flags: ReprFlags,
2092 impl_stable_hash_for!(struct ReprOptions {
2100 pub fn new(tcx: TyCtxt<'_>, did: DefId) -> ReprOptions {
2101 let mut flags = ReprFlags::empty();
2102 let mut size = None;
2103 let mut max_align: Option<Align> = None;
2104 let mut min_pack: Option<Align> = None;
2105 for attr in tcx.get_attrs(did).iter() {
2106 for r in attr::find_repr_attrs(&tcx.sess.parse_sess, attr) {
2107 flags.insert(match r {
2108 attr::ReprC => ReprFlags::IS_C,
2109 attr::ReprPacked(pack) => {
2110 let pack = Align::from_bytes(pack as u64).unwrap();
2111 min_pack = Some(if let Some(min_pack) = min_pack {
2118 attr::ReprTransparent => ReprFlags::IS_TRANSPARENT,
2119 attr::ReprSimd => ReprFlags::IS_SIMD,
2120 attr::ReprInt(i) => {
2124 attr::ReprAlign(align) => {
2125 max_align = max_align.max(Some(Align::from_bytes(align as u64).unwrap()));
2132 // This is here instead of layout because the choice must make it into metadata.
2133 if !tcx.consider_optimizing(|| format!("Reorder fields of {:?}", tcx.def_path_str(did))) {
2134 flags.insert(ReprFlags::IS_LINEAR);
2136 ReprOptions { int: size, align: max_align, pack: min_pack, flags: flags }
2140 pub fn simd(&self) -> bool { self.flags.contains(ReprFlags::IS_SIMD) }
2142 pub fn c(&self) -> bool { self.flags.contains(ReprFlags::IS_C) }
2144 pub fn packed(&self) -> bool { self.pack.is_some() }
2146 pub fn transparent(&self) -> bool { self.flags.contains(ReprFlags::IS_TRANSPARENT) }
2148 pub fn linear(&self) -> bool { self.flags.contains(ReprFlags::IS_LINEAR) }
2150 pub fn discr_type(&self) -> attr::IntType {
2151 self.int.unwrap_or(attr::SignedInt(ast::IntTy::Isize))
2154 /// Returns `true` if this `#[repr()]` should inhabit "smart enum
2155 /// layout" optimizations, such as representing `Foo<&T>` as a
2157 pub fn inhibit_enum_layout_opt(&self) -> bool {
2158 self.c() || self.int.is_some()
2161 /// Returns `true` if this `#[repr()]` should inhibit struct field reordering
2162 /// optimizations, such as with `repr(C)`, `repr(packed(1))`, or `repr(<int>)`.
2163 pub fn inhibit_struct_field_reordering_opt(&self) -> bool {
2164 if let Some(pack) = self.pack {
2165 if pack.bytes() == 1 {
2169 self.flags.intersects(ReprFlags::IS_UNOPTIMISABLE) || self.int.is_some()
2172 /// Returns `true` if this `#[repr()]` should inhibit union ABI optimisations.
2173 pub fn inhibit_union_abi_opt(&self) -> bool {
2179 /// Creates a new `AdtDef`.
2184 variants: IndexVec<VariantIdx, VariantDef>,
2187 debug!("AdtDef::new({:?}, {:?}, {:?}, {:?})", did, kind, variants, repr);
2188 let mut flags = AdtFlags::NO_ADT_FLAGS;
2190 if kind == AdtKind::Enum && tcx.has_attr(did, sym::non_exhaustive) {
2191 debug!("found non-exhaustive variant list for {:?}", did);
2192 flags = flags | AdtFlags::IS_VARIANT_LIST_NON_EXHAUSTIVE;
2195 flags |= match kind {
2196 AdtKind::Enum => AdtFlags::IS_ENUM,
2197 AdtKind::Union => AdtFlags::IS_UNION,
2198 AdtKind::Struct => AdtFlags::IS_STRUCT,
2201 if kind == AdtKind::Struct && variants[VariantIdx::new(0)].ctor_def_id.is_some() {
2202 flags |= AdtFlags::HAS_CTOR;
2205 let attrs = tcx.get_attrs(did);
2206 if attr::contains_name(&attrs, sym::fundamental) {
2207 flags |= AdtFlags::IS_FUNDAMENTAL;
2209 if Some(did) == tcx.lang_items().phantom_data() {
2210 flags |= AdtFlags::IS_PHANTOM_DATA;
2212 if Some(did) == tcx.lang_items().owned_box() {
2213 flags |= AdtFlags::IS_BOX;
2215 if Some(did) == tcx.lang_items().arc() {
2216 flags |= AdtFlags::IS_ARC;
2218 if Some(did) == tcx.lang_items().rc() {
2219 flags |= AdtFlags::IS_RC;
2230 /// Returns `true` if this is a struct.
2232 pub fn is_struct(&self) -> bool {
2233 self.flags.contains(AdtFlags::IS_STRUCT)
2236 /// Returns `true` if this is a union.
2238 pub fn is_union(&self) -> bool {
2239 self.flags.contains(AdtFlags::IS_UNION)
2242 /// Returns `true` if this is a enum.
2244 pub fn is_enum(&self) -> bool {
2245 self.flags.contains(AdtFlags::IS_ENUM)
2248 /// Returns `true` if the variant list of this ADT is `#[non_exhaustive]`.
2250 pub fn is_variant_list_non_exhaustive(&self) -> bool {
2251 self.flags.contains(AdtFlags::IS_VARIANT_LIST_NON_EXHAUSTIVE)
2254 /// Returns the kind of the ADT.
2256 pub fn adt_kind(&self) -> AdtKind {
2259 } else if self.is_union() {
2266 /// Returns a description of this abstract data type.
2267 pub fn descr(&self) -> &'static str {
2268 match self.adt_kind() {
2269 AdtKind::Struct => "struct",
2270 AdtKind::Union => "union",
2271 AdtKind::Enum => "enum",
2275 /// Returns a description of a variant of this abstract data type.
2277 pub fn variant_descr(&self) -> &'static str {
2278 match self.adt_kind() {
2279 AdtKind::Struct => "struct",
2280 AdtKind::Union => "union",
2281 AdtKind::Enum => "variant",
2285 /// If this function returns `true`, it implies that `is_struct` must return `true`.
2287 pub fn has_ctor(&self) -> bool {
2288 self.flags.contains(AdtFlags::HAS_CTOR)
2291 /// Returns `true` if this type is `#[fundamental]` for the purposes
2292 /// of coherence checking.
2294 pub fn is_fundamental(&self) -> bool {
2295 self.flags.contains(AdtFlags::IS_FUNDAMENTAL)
2298 /// Returns `true` if this is `PhantomData<T>`.
2300 pub fn is_phantom_data(&self) -> bool {
2301 self.flags.contains(AdtFlags::IS_PHANTOM_DATA)
2304 /// Returns `true` if this is `Arc<T>`.
2305 pub fn is_arc(&self) -> bool {
2306 self.flags.contains(AdtFlags::IS_ARC)
2309 /// Returns `true` if this is `Rc<T>`.
2310 pub fn is_rc(&self) -> bool {
2311 self.flags.contains(AdtFlags::IS_RC)
2314 /// Returns `true` if this is Box<T>.
2316 pub fn is_box(&self) -> bool {
2317 self.flags.contains(AdtFlags::IS_BOX)
2320 /// Returns `true` if this type has a destructor.
2321 pub fn has_dtor(&self, tcx: TyCtxt<'tcx>) -> bool {
2322 self.destructor(tcx).is_some()
2325 /// Asserts this is a struct or union and returns its unique variant.
2326 pub fn non_enum_variant(&self) -> &VariantDef {
2327 assert!(self.is_struct() || self.is_union());
2328 &self.variants[VariantIdx::new(0)]
2332 pub fn predicates(&self, tcx: TyCtxt<'tcx>) -> GenericPredicates<'tcx> {
2333 tcx.predicates_of(self.did)
2336 /// Returns an iterator over all fields contained
2339 pub fn all_fields(&self) -> impl Iterator<Item=&FieldDef> + Clone {
2340 self.variants.iter().flat_map(|v| v.fields.iter())
2343 pub fn is_payloadfree(&self) -> bool {
2344 !self.variants.is_empty() &&
2345 self.variants.iter().all(|v| v.fields.is_empty())
2348 /// Return a `VariantDef` given a variant id.
2349 pub fn variant_with_id(&self, vid: DefId) -> &VariantDef {
2350 self.variants.iter().find(|v| v.def_id == vid)
2351 .expect("variant_with_id: unknown variant")
2354 /// Return a `VariantDef` given a constructor id.
2355 pub fn variant_with_ctor_id(&self, cid: DefId) -> &VariantDef {
2356 self.variants.iter().find(|v| v.ctor_def_id == Some(cid))
2357 .expect("variant_with_ctor_id: unknown variant")
2360 /// Return the index of `VariantDef` given a variant id.
2361 pub fn variant_index_with_id(&self, vid: DefId) -> VariantIdx {
2362 self.variants.iter_enumerated().find(|(_, v)| v.def_id == vid)
2363 .expect("variant_index_with_id: unknown variant").0
2366 /// Return the index of `VariantDef` given a constructor id.
2367 pub fn variant_index_with_ctor_id(&self, cid: DefId) -> VariantIdx {
2368 self.variants.iter_enumerated().find(|(_, v)| v.ctor_def_id == Some(cid))
2369 .expect("variant_index_with_ctor_id: unknown variant").0
2372 pub fn variant_of_res(&self, res: Res) -> &VariantDef {
2374 Res::Def(DefKind::Variant, vid) => self.variant_with_id(vid),
2375 Res::Def(DefKind::Ctor(..), cid) => self.variant_with_ctor_id(cid),
2376 Res::Def(DefKind::Struct, _) | Res::Def(DefKind::Union, _) |
2377 Res::Def(DefKind::TyAlias, _) | Res::Def(DefKind::AssocTy, _) | Res::SelfTy(..) |
2378 Res::SelfCtor(..) => self.non_enum_variant(),
2379 _ => bug!("unexpected res {:?} in variant_of_res", res)
2384 pub fn eval_explicit_discr(&self, tcx: TyCtxt<'tcx>, expr_did: DefId) -> Option<Discr<'tcx>> {
2385 let param_env = tcx.param_env(expr_did);
2386 let repr_type = self.repr.discr_type();
2387 let substs = InternalSubsts::identity_for_item(tcx, expr_did);
2388 let instance = ty::Instance::new(expr_did, substs);
2389 let cid = GlobalId {
2393 match tcx.const_eval(param_env.and(cid)) {
2395 // FIXME: Find the right type and use it instead of `val.ty` here
2396 if let Some(b) = val.try_eval_bits(tcx, param_env, val.ty) {
2397 trace!("discriminants: {} ({:?})", b, repr_type);
2403 info!("invalid enum discriminant: {:#?}", val);
2404 crate::mir::interpret::struct_error(
2405 tcx.at(tcx.def_span(expr_did)),
2406 "constant evaluation of enum discriminant resulted in non-integer",
2411 Err(ErrorHandled::Reported) => {
2412 if !expr_did.is_local() {
2413 span_bug!(tcx.def_span(expr_did),
2414 "variant discriminant evaluation succeeded \
2415 in its crate but failed locally");
2419 Err(ErrorHandled::TooGeneric) => span_bug!(
2420 tcx.def_span(expr_did),
2421 "enum discriminant depends on generic arguments",
2427 pub fn discriminants(
2430 ) -> impl Iterator<Item = (VariantIdx, Discr<'tcx>)> + Captures<'tcx> {
2431 let repr_type = self.repr.discr_type();
2432 let initial = repr_type.initial_discriminant(tcx);
2433 let mut prev_discr = None::<Discr<'tcx>>;
2434 self.variants.iter_enumerated().map(move |(i, v)| {
2435 let mut discr = prev_discr.map_or(initial, |d| d.wrap_incr(tcx));
2436 if let VariantDiscr::Explicit(expr_did) = v.discr {
2437 if let Some(new_discr) = self.eval_explicit_discr(tcx, expr_did) {
2441 prev_discr = Some(discr);
2448 pub fn variant_range(&self) -> Range<VariantIdx> {
2449 (VariantIdx::new(0)..VariantIdx::new(self.variants.len()))
2452 /// Computes the discriminant value used by a specific variant.
2453 /// Unlike `discriminants`, this is (amortized) constant-time,
2454 /// only doing at most one query for evaluating an explicit
2455 /// discriminant (the last one before the requested variant),
2456 /// assuming there are no constant-evaluation errors there.
2458 pub fn discriminant_for_variant(
2461 variant_index: VariantIdx,
2463 let (val, offset) = self.discriminant_def_for_variant(variant_index);
2464 let explicit_value = val
2465 .and_then(|expr_did| self.eval_explicit_discr(tcx, expr_did))
2466 .unwrap_or_else(|| self.repr.discr_type().initial_discriminant(tcx));
2467 explicit_value.checked_add(tcx, offset as u128).0
2470 /// Yields a `DefId` for the discriminant and an offset to add to it
2471 /// Alternatively, if there is no explicit discriminant, returns the
2472 /// inferred discriminant directly.
2473 pub fn discriminant_def_for_variant(
2475 variant_index: VariantIdx,
2476 ) -> (Option<DefId>, u32) {
2477 let mut explicit_index = variant_index.as_u32();
2480 match self.variants[VariantIdx::from_u32(explicit_index)].discr {
2481 ty::VariantDiscr::Relative(0) => {
2485 ty::VariantDiscr::Relative(distance) => {
2486 explicit_index -= distance;
2488 ty::VariantDiscr::Explicit(did) => {
2489 expr_did = Some(did);
2494 (expr_did, variant_index.as_u32() - explicit_index)
2497 pub fn destructor(&self, tcx: TyCtxt<'tcx>) -> Option<Destructor> {
2498 tcx.adt_destructor(self.did)
2501 /// Returns a list of types such that `Self: Sized` if and only
2502 /// if that type is `Sized`, or `TyErr` if this type is recursive.
2504 /// Oddly enough, checking that the sized-constraint is `Sized` is
2505 /// actually more expressive than checking all members:
2506 /// the `Sized` trait is inductive, so an associated type that references
2507 /// `Self` would prevent its containing ADT from being `Sized`.
2509 /// Due to normalization being eager, this applies even if
2510 /// the associated type is behind a pointer (e.g., issue #31299).
2511 pub fn sized_constraint(&self, tcx: TyCtxt<'tcx>) -> &'tcx [Ty<'tcx>] {
2512 tcx.adt_sized_constraint(self.did).0
2515 fn sized_constraint_for_ty(&self, tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Vec<Ty<'tcx>> {
2516 let result = match ty.kind {
2517 Bool | Char | Int(..) | Uint(..) | Float(..) |
2518 RawPtr(..) | Ref(..) | FnDef(..) | FnPtr(_) |
2519 Array(..) | Closure(..) | Generator(..) | Never => {
2528 GeneratorWitness(..) => {
2529 // these are never sized - return the target type
2536 Some(ty) => self.sized_constraint_for_ty(tcx, ty.expect_ty()),
2540 Adt(adt, substs) => {
2542 let adt_tys = adt.sized_constraint(tcx);
2543 debug!("sized_constraint_for_ty({:?}) intermediate = {:?}",
2546 .map(|ty| ty.subst(tcx, substs))
2547 .flat_map(|ty| self.sized_constraint_for_ty(tcx, ty))
2551 Projection(..) | Opaque(..) => {
2552 // must calculate explicitly.
2553 // FIXME: consider special-casing always-Sized projections
2557 UnnormalizedProjection(..) => bug!("only used with chalk-engine"),
2560 // perf hack: if there is a `T: Sized` bound, then
2561 // we know that `T` is Sized and do not need to check
2564 let sized_trait = match tcx.lang_items().sized_trait() {
2566 _ => return vec![ty]
2568 let sized_predicate = Binder::dummy(TraitRef {
2569 def_id: sized_trait,
2570 substs: tcx.mk_substs_trait(ty, &[])
2572 let predicates = tcx.predicates_of(self.did).predicates;
2573 if predicates.iter().any(|(p, _)| *p == sized_predicate) {
2583 bug!("unexpected type `{:?}` in sized_constraint_for_ty",
2587 debug!("sized_constraint_for_ty({:?}) = {:?}", ty, result);
2592 impl<'tcx> FieldDef {
2593 /// Returns the type of this field. The `subst` is typically obtained
2594 /// via the second field of `TyKind::AdtDef`.
2595 pub fn ty(&self, tcx: TyCtxt<'tcx>, subst: SubstsRef<'tcx>) -> Ty<'tcx> {
2596 tcx.type_of(self.did).subst(tcx, subst)
2600 /// Represents the various closure traits in the language. This
2601 /// will determine the type of the environment (`self`, in the
2602 /// desugaring) argument that the closure expects.
2604 /// You can get the environment type of a closure using
2605 /// `tcx.closure_env_ty()`.
2606 #[derive(Clone, Copy, PartialOrd, Ord, PartialEq, Eq, Hash, Debug,
2607 RustcEncodable, RustcDecodable, HashStable)]
2608 pub enum ClosureKind {
2609 // Warning: Ordering is significant here! The ordering is chosen
2610 // because the trait Fn is a subtrait of FnMut and so in turn, and
2611 // hence we order it so that Fn < FnMut < FnOnce.
2617 impl<'tcx> ClosureKind {
2618 // This is the initial value used when doing upvar inference.
2619 pub const LATTICE_BOTTOM: ClosureKind = ClosureKind::Fn;
2621 pub fn trait_did(&self, tcx: TyCtxt<'tcx>) -> DefId {
2623 ClosureKind::Fn => tcx.require_lang_item(FnTraitLangItem, None),
2624 ClosureKind::FnMut => {
2625 tcx.require_lang_item(FnMutTraitLangItem, None)
2627 ClosureKind::FnOnce => {
2628 tcx.require_lang_item(FnOnceTraitLangItem, None)
2633 /// Returns `true` if this a type that impls this closure kind
2634 /// must also implement `other`.
2635 pub fn extends(self, other: ty::ClosureKind) -> bool {
2636 match (self, other) {
2637 (ClosureKind::Fn, ClosureKind::Fn) => true,
2638 (ClosureKind::Fn, ClosureKind::FnMut) => true,
2639 (ClosureKind::Fn, ClosureKind::FnOnce) => true,
2640 (ClosureKind::FnMut, ClosureKind::FnMut) => true,
2641 (ClosureKind::FnMut, ClosureKind::FnOnce) => true,
2642 (ClosureKind::FnOnce, ClosureKind::FnOnce) => true,
2647 /// Returns the representative scalar type for this closure kind.
2648 /// See `TyS::to_opt_closure_kind` for more details.
2649 pub fn to_ty(self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> {
2651 ty::ClosureKind::Fn => tcx.types.i8,
2652 ty::ClosureKind::FnMut => tcx.types.i16,
2653 ty::ClosureKind::FnOnce => tcx.types.i32,
2658 impl<'tcx> TyS<'tcx> {
2659 /// Iterator that walks `self` and any types reachable from
2660 /// `self`, in depth-first order. Note that just walks the types
2661 /// that appear in `self`, it does not descend into the fields of
2662 /// structs or variants. For example:
2665 /// isize => { isize }
2666 /// Foo<Bar<isize>> => { Foo<Bar<isize>>, Bar<isize>, isize }
2667 /// [isize] => { [isize], isize }
2669 pub fn walk(&'tcx self) -> TypeWalker<'tcx> {
2670 TypeWalker::new(self)
2673 /// Iterator that walks the immediate children of `self`. Hence
2674 /// `Foo<Bar<i32>, u32>` yields the sequence `[Bar<i32>, u32]`
2675 /// (but not `i32`, like `walk`).
2676 pub fn walk_shallow(&'tcx self) -> smallvec::IntoIter<walk::TypeWalkerArray<'tcx>> {
2677 walk::walk_shallow(self)
2680 /// Walks `ty` and any types appearing within `ty`, invoking the
2681 /// callback `f` on each type. If the callback returns `false`, then the
2682 /// children of the current type are ignored.
2684 /// Note: prefer `ty.walk()` where possible.
2685 pub fn maybe_walk<F>(&'tcx self, mut f: F)
2686 where F: FnMut(Ty<'tcx>) -> bool
2688 let mut walker = self.walk();
2689 while let Some(ty) = walker.next() {
2691 walker.skip_current_subtree();
2698 pub fn from_mutbl(m: hir::Mutability) -> BorrowKind {
2700 hir::Mutability::Mutable => MutBorrow,
2701 hir::Mutability::Immutable => ImmBorrow,
2705 /// Returns a mutability `m` such that an `&m T` pointer could be used to obtain this borrow
2706 /// kind. Because borrow kinds are richer than mutabilities, we sometimes have to pick a
2707 /// mutability that is stronger than necessary so that it at least *would permit* the borrow in
2709 pub fn to_mutbl_lossy(self) -> hir::Mutability {
2711 MutBorrow => hir::Mutability::Mutable,
2712 ImmBorrow => hir::Mutability::Immutable,
2714 // We have no type corresponding to a unique imm borrow, so
2715 // use `&mut`. It gives all the capabilities of an `&uniq`
2716 // and hence is a safe "over approximation".
2717 UniqueImmBorrow => hir::Mutability::Mutable,
2721 pub fn to_user_str(&self) -> &'static str {
2723 MutBorrow => "mutable",
2724 ImmBorrow => "immutable",
2725 UniqueImmBorrow => "uniquely immutable",
2730 #[derive(Debug, Clone)]
2731 pub enum Attributes<'tcx> {
2732 Owned(Lrc<[ast::Attribute]>),
2733 Borrowed(&'tcx [ast::Attribute]),
2736 impl<'tcx> ::std::ops::Deref for Attributes<'tcx> {
2737 type Target = [ast::Attribute];
2739 fn deref(&self) -> &[ast::Attribute] {
2741 &Attributes::Owned(ref data) => &data,
2742 &Attributes::Borrowed(data) => data
2747 #[derive(Debug, PartialEq, Eq)]
2748 pub enum ImplOverlapKind {
2749 /// These impls are always allowed to overlap.
2751 /// These impls are allowed to overlap, but that raises
2752 /// an issue #33140 future-compatibility warning.
2754 /// Some background: in Rust 1.0, the trait-object types `Send + Sync` (today's
2755 /// `dyn Send + Sync`) and `Sync + Send` (now `dyn Sync + Send`) were different.
2757 /// The widely-used version 0.1.0 of the crate `traitobject` had accidentally relied
2758 /// that difference, making what reduces to the following set of impls:
2762 /// impl Trait for dyn Send + Sync {}
2763 /// impl Trait for dyn Sync + Send {}
2766 /// Obviously, once we made these types be identical, that code causes a coherence
2767 /// error and a fairly big headache for us. However, luckily for us, the trait
2768 /// `Trait` used in this case is basically a marker trait, and therefore having
2769 /// overlapping impls for it is sound.
2771 /// To handle this, we basically regard the trait as a marker trait, with an additional
2772 /// future-compatibility warning. To avoid accidentally "stabilizing" this feature,
2773 /// it has the following restrictions:
2775 /// 1. The trait must indeed be a marker-like trait (i.e., no items), and must be
2777 /// 2. The trait-ref of both impls must be equal.
2778 /// 3. The trait-ref of both impls must be a trait object type consisting only of
2780 /// 4. Neither of the impls can have any where-clauses.
2782 /// Once `traitobject` 0.1.0 is no longer an active concern, this hack can be removed.
2786 impl<'tcx> TyCtxt<'tcx> {
2787 pub fn body_tables(self, body: hir::BodyId) -> &'tcx TypeckTables<'tcx> {
2788 self.typeck_tables_of(self.hir().body_owner_def_id(body))
2791 /// Returns an iterator of the `DefId`s for all body-owners in this
2792 /// crate. If you would prefer to iterate over the bodies
2793 /// themselves, you can do `self.hir().krate().body_ids.iter()`.
2794 pub fn body_owners(self) -> impl Iterator<Item = DefId> + Captures<'tcx> + 'tcx {
2798 .map(move |&body_id| self.hir().body_owner_def_id(body_id))
2801 pub fn par_body_owners<F: Fn(DefId) + sync::Sync + sync::Send>(self, f: F) {
2802 par_iter(&self.hir().krate().body_ids).for_each(|&body_id| {
2803 f(self.hir().body_owner_def_id(body_id))
2807 pub fn provided_trait_methods(self, id: DefId) -> Vec<AssocItem> {
2808 self.associated_items(id)
2809 .filter(|item| item.kind == AssocKind::Method && item.defaultness.has_value())
2813 pub fn trait_relevant_for_never(self, did: DefId) -> bool {
2814 self.associated_items(did).any(|item| {
2815 item.relevant_for_never()
2819 pub fn opt_item_name(self, def_id: DefId) -> Option<Ident> {
2820 self.hir().as_local_hir_id(def_id).and_then(|hir_id| self.hir().get(hir_id).ident())
2823 pub fn opt_associated_item(self, def_id: DefId) -> Option<AssocItem> {
2824 let is_associated_item = if let Some(hir_id) = self.hir().as_local_hir_id(def_id) {
2825 match self.hir().get(hir_id) {
2826 Node::TraitItem(_) | Node::ImplItem(_) => true,
2830 match self.def_kind(def_id).expect("no def for `DefId`") {
2833 | DefKind::AssocTy => true,
2838 if is_associated_item {
2839 Some(self.associated_item(def_id))
2845 fn associated_item_from_trait_item_ref(self,
2846 parent_def_id: DefId,
2847 parent_vis: &hir::Visibility,
2848 trait_item_ref: &hir::TraitItemRef)
2850 let def_id = self.hir().local_def_id(trait_item_ref.id.hir_id);
2851 let (kind, has_self) = match trait_item_ref.kind {
2852 hir::AssocItemKind::Const => (ty::AssocKind::Const, false),
2853 hir::AssocItemKind::Method { has_self } => {
2854 (ty::AssocKind::Method, has_self)
2856 hir::AssocItemKind::Type => (ty::AssocKind::Type, false),
2857 hir::AssocItemKind::OpaqueTy => bug!("only impls can have opaque types"),
2861 ident: trait_item_ref.ident,
2863 // Visibility of trait items is inherited from their traits.
2864 vis: Visibility::from_hir(parent_vis, trait_item_ref.id.hir_id, self),
2865 defaultness: trait_item_ref.defaultness,
2867 container: TraitContainer(parent_def_id),
2868 method_has_self_argument: has_self
2872 fn associated_item_from_impl_item_ref(self,
2873 parent_def_id: DefId,
2874 impl_item_ref: &hir::ImplItemRef)
2876 let def_id = self.hir().local_def_id(impl_item_ref.id.hir_id);
2877 let (kind, has_self) = match impl_item_ref.kind {
2878 hir::AssocItemKind::Const => (ty::AssocKind::Const, false),
2879 hir::AssocItemKind::Method { has_self } => {
2880 (ty::AssocKind::Method, has_self)
2882 hir::AssocItemKind::Type => (ty::AssocKind::Type, false),
2883 hir::AssocItemKind::OpaqueTy => (ty::AssocKind::OpaqueTy, false),
2887 ident: impl_item_ref.ident,
2889 // Visibility of trait impl items doesn't matter.
2890 vis: ty::Visibility::from_hir(&impl_item_ref.vis, impl_item_ref.id.hir_id, self),
2891 defaultness: impl_item_ref.defaultness,
2893 container: ImplContainer(parent_def_id),
2894 method_has_self_argument: has_self
2898 pub fn field_index(self, hir_id: hir::HirId, tables: &TypeckTables<'_>) -> usize {
2899 tables.field_indices().get(hir_id).cloned().expect("no index for a field")
2902 pub fn find_field_index(self, ident: Ident, variant: &VariantDef) -> Option<usize> {
2903 variant.fields.iter().position(|field| {
2904 self.hygienic_eq(ident, field.ident, variant.def_id)
2908 pub fn associated_items(self, def_id: DefId) -> AssocItemsIterator<'tcx> {
2909 // Ideally, we would use `-> impl Iterator` here, but it falls
2910 // afoul of the conservative "capture [restrictions]" we put
2911 // in place, so we use a hand-written iterator.
2913 // [restrictions]: https://github.com/rust-lang/rust/issues/34511#issuecomment-373423999
2914 AssocItemsIterator {
2916 def_ids: self.associated_item_def_ids(def_id),
2921 /// Returns `true` if the impls are the same polarity and the trait either
2922 /// has no items or is annotated #[marker] and prevents item overrides.
2923 pub fn impls_are_allowed_to_overlap(self, def_id1: DefId, def_id2: DefId)
2924 -> Option<ImplOverlapKind>
2926 // If either trait impl references an error, they're allowed to overlap,
2927 // as one of them essentially doesn't exist.
2928 if self.impl_trait_ref(def_id1).map_or(false, |tr| tr.references_error()) ||
2929 self.impl_trait_ref(def_id2).map_or(false, |tr| tr.references_error()) {
2930 return Some(ImplOverlapKind::Permitted);
2933 match (self.impl_polarity(def_id1), self.impl_polarity(def_id2)) {
2934 (ImplPolarity::Reservation, _) |
2935 (_, ImplPolarity::Reservation) => {
2936 // `#[rustc_reservation_impl]` impls don't overlap with anything
2937 debug!("impls_are_allowed_to_overlap({:?}, {:?}) = Some(Permitted) (reservations)",
2939 return Some(ImplOverlapKind::Permitted);
2941 (ImplPolarity::Positive, ImplPolarity::Negative) |
2942 (ImplPolarity::Negative, ImplPolarity::Positive) => {
2943 // `impl AutoTrait for Type` + `impl !AutoTrait for Type`
2944 debug!("impls_are_allowed_to_overlap({:?}, {:?}) - None (differing polarities)",
2948 (ImplPolarity::Positive, ImplPolarity::Positive) |
2949 (ImplPolarity::Negative, ImplPolarity::Negative) => {}
2952 let is_marker_overlap = if self.features().overlapping_marker_traits {
2953 let trait1_is_empty = self.impl_trait_ref(def_id1)
2954 .map_or(false, |trait_ref| {
2955 self.associated_item_def_ids(trait_ref.def_id).is_empty()
2957 let trait2_is_empty = self.impl_trait_ref(def_id2)
2958 .map_or(false, |trait_ref| {
2959 self.associated_item_def_ids(trait_ref.def_id).is_empty()
2961 trait1_is_empty && trait2_is_empty
2963 let is_marker_impl = |def_id: DefId| -> bool {
2964 let trait_ref = self.impl_trait_ref(def_id);
2965 trait_ref.map_or(false, |tr| self.trait_def(tr.def_id).is_marker)
2967 is_marker_impl(def_id1) && is_marker_impl(def_id2)
2971 if is_marker_overlap {
2972 debug!("impls_are_allowed_to_overlap({:?}, {:?}) = Some(Permitted) (marker overlap)",
2974 Some(ImplOverlapKind::Permitted)
2976 if let Some(self_ty1) = self.issue33140_self_ty(def_id1) {
2977 if let Some(self_ty2) = self.issue33140_self_ty(def_id2) {
2978 if self_ty1 == self_ty2 {
2979 debug!("impls_are_allowed_to_overlap({:?}, {:?}) - issue #33140 HACK",
2981 return Some(ImplOverlapKind::Issue33140);
2983 debug!("impls_are_allowed_to_overlap({:?}, {:?}) - found {:?} != {:?}",
2984 def_id1, def_id2, self_ty1, self_ty2);
2989 debug!("impls_are_allowed_to_overlap({:?}, {:?}) = None",
2995 /// Returns `ty::VariantDef` if `res` refers to a struct,
2996 /// or variant or their constructors, panics otherwise.
2997 pub fn expect_variant_res(self, res: Res) -> &'tcx VariantDef {
2999 Res::Def(DefKind::Variant, did) => {
3000 let enum_did = self.parent(did).unwrap();
3001 self.adt_def(enum_did).variant_with_id(did)
3003 Res::Def(DefKind::Struct, did) | Res::Def(DefKind::Union, did) => {
3004 self.adt_def(did).non_enum_variant()
3006 Res::Def(DefKind::Ctor(CtorOf::Variant, ..), variant_ctor_did) => {
3007 let variant_did = self.parent(variant_ctor_did).unwrap();
3008 let enum_did = self.parent(variant_did).unwrap();
3009 self.adt_def(enum_did).variant_with_ctor_id(variant_ctor_did)
3011 Res::Def(DefKind::Ctor(CtorOf::Struct, ..), ctor_did) => {
3012 let struct_did = self.parent(ctor_did).expect("struct ctor has no parent");
3013 self.adt_def(struct_did).non_enum_variant()
3015 _ => bug!("expect_variant_res used with unexpected res {:?}", res)
3019 pub fn item_name(self, id: DefId) -> Symbol {
3020 if id.index == CRATE_DEF_INDEX {
3021 self.original_crate_name(id.krate)
3023 let def_key = self.def_key(id);
3024 match def_key.disambiguated_data.data {
3025 // The name of a constructor is that of its parent.
3026 hir_map::DefPathData::Ctor =>
3027 self.item_name(DefId {
3029 index: def_key.parent.unwrap()
3031 _ => def_key.disambiguated_data.data.get_opt_name().unwrap_or_else(|| {
3032 bug!("item_name: no name for {:?}", self.def_path(id));
3038 /// Returns the possibly-auto-generated MIR of a `(DefId, Subst)` pair.
3039 pub fn instance_mir(self, instance: ty::InstanceDef<'tcx>) -> &'tcx Body<'tcx> {
3041 ty::InstanceDef::Item(did) => {
3042 self.optimized_mir(did)
3044 ty::InstanceDef::VtableShim(..) |
3045 ty::InstanceDef::ReifyShim(..) |
3046 ty::InstanceDef::Intrinsic(..) |
3047 ty::InstanceDef::FnPtrShim(..) |
3048 ty::InstanceDef::Virtual(..) |
3049 ty::InstanceDef::ClosureOnceShim { .. } |
3050 ty::InstanceDef::DropGlue(..) |
3051 ty::InstanceDef::CloneShim(..) => {
3052 self.mir_shims(instance)
3057 /// Gets the attributes of a definition.
3058 pub fn get_attrs(self, did: DefId) -> Attributes<'tcx> {
3059 if let Some(id) = self.hir().as_local_hir_id(did) {
3060 Attributes::Borrowed(self.hir().attrs(id))
3062 Attributes::Owned(self.item_attrs(did))
3066 /// Determines whether an item is annotated with an attribute.
3067 pub fn has_attr(self, did: DefId, attr: Symbol) -> bool {
3068 attr::contains_name(&self.get_attrs(did), attr)
3071 /// Returns `true` if this is an `auto trait`.
3072 pub fn trait_is_auto(self, trait_def_id: DefId) -> bool {
3073 self.trait_def(trait_def_id).has_auto_impl
3076 pub fn generator_layout(self, def_id: DefId) -> &'tcx GeneratorLayout<'tcx> {
3077 self.optimized_mir(def_id).generator_layout.as_ref().unwrap()
3080 /// Given the `DefId` of an impl, returns the `DefId` of the trait it implements.
3081 /// If it implements no trait, returns `None`.
3082 pub fn trait_id_of_impl(self, def_id: DefId) -> Option<DefId> {
3083 self.impl_trait_ref(def_id).map(|tr| tr.def_id)
3086 /// If the given defid describes a method belonging to an impl, returns the
3087 /// `DefId` of the impl that the method belongs to; otherwise, returns `None`.
3088 pub fn impl_of_method(self, def_id: DefId) -> Option<DefId> {
3089 let item = if def_id.krate != LOCAL_CRATE {
3090 if let Some(DefKind::Method) = self.def_kind(def_id) {
3091 Some(self.associated_item(def_id))
3096 self.opt_associated_item(def_id)
3099 item.and_then(|trait_item|
3100 match trait_item.container {
3101 TraitContainer(_) => None,
3102 ImplContainer(def_id) => Some(def_id),
3107 /// Looks up the span of `impl_did` if the impl is local; otherwise returns `Err`
3108 /// with the name of the crate containing the impl.
3109 pub fn span_of_impl(self, impl_did: DefId) -> Result<Span, Symbol> {
3110 if impl_did.is_local() {
3111 let hir_id = self.hir().as_local_hir_id(impl_did).unwrap();
3112 Ok(self.hir().span(hir_id))
3114 Err(self.crate_name(impl_did.krate))
3118 /// Hygienically compares a use-site name (`use_name`) for a field or an associated item with
3119 /// its supposed definition name (`def_name`). The method also needs `DefId` of the supposed
3120 /// definition's parent/scope to perform comparison.
3121 pub fn hygienic_eq(self, use_name: Ident, def_name: Ident, def_parent_def_id: DefId) -> bool {
3122 // We could use `Ident::eq` here, but we deliberately don't. The name
3123 // comparison fails frequently, and we want to avoid the expensive
3124 // `modern()` calls required for the span comparison whenever possible.
3125 use_name.name == def_name.name &&
3126 use_name.span.ctxt().hygienic_eq(def_name.span.ctxt(),
3127 self.expansion_that_defined(def_parent_def_id))
3130 fn expansion_that_defined(self, scope: DefId) -> ExpnId {
3132 LOCAL_CRATE => self.hir().definitions().expansion_that_defined(scope.index),
3133 _ => ExpnId::root(),
3137 pub fn adjust_ident(self, mut ident: Ident, scope: DefId) -> Ident {
3138 ident.span.modernize_and_adjust(self.expansion_that_defined(scope));
3142 pub fn adjust_ident_and_get_scope(self, mut ident: Ident, scope: DefId, block: hir::HirId)
3144 let scope = match ident.span.modernize_and_adjust(self.expansion_that_defined(scope)) {
3145 Some(actual_expansion) =>
3146 self.hir().definitions().parent_module_of_macro_def(actual_expansion),
3147 None => self.hir().get_module_parent(block),
3154 pub struct AssocItemsIterator<'tcx> {
3156 def_ids: &'tcx [DefId],
3160 impl Iterator for AssocItemsIterator<'_> {
3161 type Item = AssocItem;
3163 fn next(&mut self) -> Option<AssocItem> {
3164 let def_id = self.def_ids.get(self.next_index)?;
3165 self.next_index += 1;
3166 Some(self.tcx.associated_item(*def_id))
3170 fn associated_item(tcx: TyCtxt<'_>, def_id: DefId) -> AssocItem {
3171 let id = tcx.hir().as_local_hir_id(def_id).unwrap();
3172 let parent_id = tcx.hir().get_parent_item(id);
3173 let parent_def_id = tcx.hir().local_def_id(parent_id);
3174 let parent_item = tcx.hir().expect_item(parent_id);
3175 match parent_item.kind {
3176 hir::ItemKind::Impl(.., ref impl_item_refs) => {
3177 if let Some(impl_item_ref) = impl_item_refs.iter().find(|i| i.id.hir_id == id) {
3178 let assoc_item = tcx.associated_item_from_impl_item_ref(parent_def_id,
3180 debug_assert_eq!(assoc_item.def_id, def_id);
3185 hir::ItemKind::Trait(.., ref trait_item_refs) => {
3186 if let Some(trait_item_ref) = trait_item_refs.iter().find(|i| i.id.hir_id == id) {
3187 let assoc_item = tcx.associated_item_from_trait_item_ref(parent_def_id,
3190 debug_assert_eq!(assoc_item.def_id, def_id);
3198 span_bug!(parent_item.span,
3199 "unexpected parent of trait or impl item or item not found: {:?}",
3203 #[derive(Clone, HashStable)]
3204 pub struct AdtSizedConstraint<'tcx>(pub &'tcx [Ty<'tcx>]);
3206 /// Calculates the `Sized` constraint.
3208 /// In fact, there are only a few options for the types in the constraint:
3209 /// - an obviously-unsized type
3210 /// - a type parameter or projection whose Sizedness can't be known
3211 /// - a tuple of type parameters or projections, if there are multiple
3213 /// - a Error, if a type contained itself. The representability
3214 /// check should catch this case.
3215 fn adt_sized_constraint(tcx: TyCtxt<'_>, def_id: DefId) -> AdtSizedConstraint<'_> {
3216 let def = tcx.adt_def(def_id);
3218 let result = tcx.mk_type_list(def.variants.iter().flat_map(|v| {
3221 def.sized_constraint_for_ty(tcx, tcx.type_of(f.did))
3224 debug!("adt_sized_constraint: {:?} => {:?}", def, result);
3226 AdtSizedConstraint(result)
3229 fn associated_item_def_ids(tcx: TyCtxt<'_>, def_id: DefId) -> &[DefId] {
3230 let id = tcx.hir().as_local_hir_id(def_id).unwrap();
3231 let item = tcx.hir().expect_item(id);
3233 hir::ItemKind::Trait(.., ref trait_item_refs) => {
3234 tcx.arena.alloc_from_iter(
3235 trait_item_refs.iter()
3236 .map(|trait_item_ref| trait_item_ref.id)
3237 .map(|id| tcx.hir().local_def_id(id.hir_id))
3240 hir::ItemKind::Impl(.., ref impl_item_refs) => {
3241 tcx.arena.alloc_from_iter(
3242 impl_item_refs.iter()
3243 .map(|impl_item_ref| impl_item_ref.id)
3244 .map(|id| tcx.hir().local_def_id(id.hir_id))
3247 hir::ItemKind::TraitAlias(..) => &[],
3248 _ => span_bug!(item.span, "associated_item_def_ids: not impl or trait")
3252 fn def_span(tcx: TyCtxt<'_>, def_id: DefId) -> Span {
3253 tcx.hir().span_if_local(def_id).unwrap()
3256 /// If the given `DefId` describes an item belonging to a trait,
3257 /// returns the `DefId` of the trait that the trait item belongs to;
3258 /// otherwise, returns `None`.
3259 fn trait_of_item(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
3260 tcx.opt_associated_item(def_id)
3261 .and_then(|associated_item| {
3262 match associated_item.container {
3263 TraitContainer(def_id) => Some(def_id),
3264 ImplContainer(_) => None
3269 /// Yields the parent function's `DefId` if `def_id` is an `impl Trait` definition.
3270 pub fn is_impl_trait_defn(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
3271 if let Some(hir_id) = tcx.hir().as_local_hir_id(def_id) {
3272 if let Node::Item(item) = tcx.hir().get(hir_id) {
3273 if let hir::ItemKind::OpaqueTy(ref opaque_ty) = item.kind {
3274 return opaque_ty.impl_trait_fn;
3281 /// See `ParamEnv` struct definition for details.
3282 fn param_env(tcx: TyCtxt<'_>, def_id: DefId) -> ParamEnv<'_> {
3283 // The param_env of an impl Trait type is its defining function's param_env
3284 if let Some(parent) = is_impl_trait_defn(tcx, def_id) {
3285 return param_env(tcx, parent);
3287 // Compute the bounds on Self and the type parameters.
3289 let InstantiatedPredicates { predicates } =
3290 tcx.predicates_of(def_id).instantiate_identity(tcx);
3292 // Finally, we have to normalize the bounds in the environment, in
3293 // case they contain any associated type projections. This process
3294 // can yield errors if the put in illegal associated types, like
3295 // `<i32 as Foo>::Bar` where `i32` does not implement `Foo`. We
3296 // report these errors right here; this doesn't actually feel
3297 // right to me, because constructing the environment feels like a
3298 // kind of a "idempotent" action, but I'm not sure where would be
3299 // a better place. In practice, we construct environments for
3300 // every fn once during type checking, and we'll abort if there
3301 // are any errors at that point, so after type checking you can be
3302 // sure that this will succeed without errors anyway.
3304 let unnormalized_env = ty::ParamEnv::new(
3305 tcx.intern_predicates(&predicates),
3306 traits::Reveal::UserFacing,
3307 if tcx.sess.opts.debugging_opts.chalk { Some(def_id) } else { None }
3310 let body_id = tcx.hir().as_local_hir_id(def_id).map_or(hir::DUMMY_HIR_ID, |id| {
3311 tcx.hir().maybe_body_owned_by(id).map_or(id, |body| body.hir_id)
3313 let cause = traits::ObligationCause::misc(tcx.def_span(def_id), body_id);
3314 traits::normalize_param_env_or_error(tcx, def_id, unnormalized_env, cause)
3317 fn crate_disambiguator(tcx: TyCtxt<'_>, crate_num: CrateNum) -> CrateDisambiguator {
3318 assert_eq!(crate_num, LOCAL_CRATE);
3319 tcx.sess.local_crate_disambiguator()
3322 fn original_crate_name(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Symbol {
3323 assert_eq!(crate_num, LOCAL_CRATE);
3324 tcx.crate_name.clone()
3327 fn crate_hash(tcx: TyCtxt<'_>, crate_num: CrateNum) -> Svh {
3328 assert_eq!(crate_num, LOCAL_CRATE);
3329 tcx.hir().crate_hash
3332 fn instance_def_size_estimate<'tcx>(tcx: TyCtxt<'tcx>, instance_def: InstanceDef<'tcx>) -> usize {
3333 match instance_def {
3334 InstanceDef::Item(..) |
3335 InstanceDef::DropGlue(..) => {
3336 let mir = tcx.instance_mir(instance_def);
3337 mir.basic_blocks().iter().map(|bb| bb.statements.len()).sum()
3339 // Estimate the size of other compiler-generated shims to be 1.
3344 /// If `def_id` is an issue 33140 hack impl, returns its self type; otherwise, returns `None`.
3346 /// See [`ImplOverlapKind::Issue33140`] for more details.
3347 fn issue33140_self_ty(tcx: TyCtxt<'_>, def_id: DefId) -> Option<Ty<'_>> {
3348 debug!("issue33140_self_ty({:?})", def_id);
3350 let trait_ref = tcx.impl_trait_ref(def_id).unwrap_or_else(|| {
3351 bug!("issue33140_self_ty called on inherent impl {:?}", def_id)
3354 debug!("issue33140_self_ty({:?}), trait-ref={:?}", def_id, trait_ref);
3356 let is_marker_like =
3357 tcx.impl_polarity(def_id) == ty::ImplPolarity::Positive &&
3358 tcx.associated_item_def_ids(trait_ref.def_id).is_empty();
3360 // Check whether these impls would be ok for a marker trait.
3361 if !is_marker_like {
3362 debug!("issue33140_self_ty - not marker-like!");
3366 // impl must be `impl Trait for dyn Marker1 + Marker2 + ...`
3367 if trait_ref.substs.len() != 1 {
3368 debug!("issue33140_self_ty - impl has substs!");
3372 let predicates = tcx.predicates_of(def_id);
3373 if predicates.parent.is_some() || !predicates.predicates.is_empty() {
3374 debug!("issue33140_self_ty - impl has predicates {:?}!", predicates);
3378 let self_ty = trait_ref.self_ty();
3379 let self_ty_matches = match self_ty.kind {
3380 ty::Dynamic(ref data, ty::ReStatic) => data.principal().is_none(),
3384 if self_ty_matches {
3385 debug!("issue33140_self_ty - MATCHES!");
3388 debug!("issue33140_self_ty - non-matching self type");
3393 /// Check if a function is async.
3394 fn asyncness(tcx: TyCtxt<'_>, def_id: DefId) -> hir::IsAsync {
3395 let hir_id = tcx.hir().as_local_hir_id(def_id).unwrap_or_else(|| {
3396 bug!("asyncness: expected local `DefId`, got `{:?}`", def_id)
3399 let node = tcx.hir().get(hir_id);
3401 let fn_like = hir::map::blocks::FnLikeNode::from_node(node).unwrap_or_else(|| {
3402 bug!("asyncness: expected fn-like node but got `{:?}`", def_id);
3408 pub fn provide(providers: &mut ty::query::Providers<'_>) {
3409 context::provide(providers);
3410 erase_regions::provide(providers);
3411 layout::provide(providers);
3412 util::provide(providers);
3413 constness::provide(providers);
3414 *providers = ty::query::Providers {
3417 associated_item_def_ids,
3418 adt_sized_constraint,
3422 crate_disambiguator,
3423 original_crate_name,
3425 trait_impls_of: trait_def::trait_impls_of_provider,
3426 instance_def_size_estimate,
3432 /// A map for the local crate mapping each type to a vector of its
3433 /// inherent impls. This is not meant to be used outside of coherence;
3434 /// rather, you should request the vector for a specific type via
3435 /// `tcx.inherent_impls(def_id)` so as to minimize your dependencies
3436 /// (constructing this map requires touching the entire crate).
3437 #[derive(Clone, Debug, Default, HashStable)]
3438 pub struct CrateInherentImpls {
3439 pub inherent_impls: DefIdMap<Vec<DefId>>,
3442 #[derive(Clone, Copy, PartialEq, Eq, RustcEncodable, RustcDecodable)]
3443 pub struct SymbolName {
3444 // FIXME: we don't rely on interning or equality here - better have
3445 // this be a `&'tcx str`.
3449 impl_stable_hash_for!(struct self::SymbolName {
3454 pub fn new(name: &str) -> SymbolName {
3456 name: Symbol::intern(name)
3461 impl PartialOrd for SymbolName {
3462 fn partial_cmp(&self, other: &SymbolName) -> Option<Ordering> {
3463 self.name.as_str().partial_cmp(&other.name.as_str())
3467 /// Ordering must use the chars to ensure reproducible builds.
3468 impl Ord for SymbolName {
3469 fn cmp(&self, other: &SymbolName) -> Ordering {
3470 self.name.as_str().cmp(&other.name.as_str())
3474 impl fmt::Display for SymbolName {
3475 fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
3476 fmt::Display::fmt(&self.name, fmt)
3480 impl fmt::Debug for SymbolName {
3481 fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
3482 fmt::Display::fmt(&self.name, fmt)