1 use crate::def::{CtorKind, DefKind, Res};
2 use crate::def_id::DefId;
3 pub(crate) use crate::hir_id::{HirId, ItemLocalId};
4 use crate::intravisit::FnKind;
8 use rustc_ast::util::parser::ExprPrecedence;
9 use rustc_ast::{Attribute, FloatTy, IntTy, Label, LitKind, TraitObjectSyntax, UintTy};
10 pub use rustc_ast::{BorrowKind, ImplPolarity, IsAuto};
11 pub use rustc_ast::{CaptureBy, Movability, Mutability};
12 use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
13 use rustc_data_structures::fingerprint::Fingerprint;
14 use rustc_data_structures::fx::FxHashMap;
15 use rustc_data_structures::sorted_map::SortedMap;
16 use rustc_error_messages::MultiSpan;
17 use rustc_index::vec::IndexVec;
18 use rustc_macros::HashStable_Generic;
19 use rustc_span::hygiene::MacroKind;
20 use rustc_span::source_map::Spanned;
21 use rustc_span::symbol::{kw, sym, Ident, Symbol};
22 use rustc_span::{def_id::LocalDefId, BytePos, Span, DUMMY_SP};
23 use rustc_target::asm::InlineAsmRegOrRegClass;
24 use rustc_target::spec::abi::Abi;
26 use smallvec::SmallVec;
29 #[derive(Debug, Copy, Clone, Encodable, HashStable_Generic)]
34 /// Either "`'a`", referring to a named lifetime definition,
35 /// or "``" (i.e., `kw::Empty`), for elision placeholders.
37 /// HIR lowering inserts these placeholders in type paths that
38 /// refer to type definitions needing lifetime parameters,
39 /// `&T` and `&mut T`, and trait objects without `... + 'a`.
40 pub name: LifetimeName,
43 #[derive(Debug, Clone, PartialEq, Eq, Encodable, Hash, Copy)]
44 #[derive(HashStable_Generic)]
46 /// Some user-given name like `T` or `'x`.
49 /// Synthetic name generated when user elided a lifetime in an impl header.
51 /// E.g., the lifetimes in cases like these:
52 /// ```ignore (fragment)
54 /// impl Foo<'_> for u32
56 /// in that case, we rewrite to
57 /// ```ignore (fragment)
58 /// impl<'f> Foo for &'f u32
59 /// impl<'f> Foo<'f> for u32
61 /// where `'f` is something like `Fresh(0)`. The indices are
62 /// unique per impl, but not necessarily continuous.
65 /// Indicates an illegal name was given and an error has been
66 /// reported (so we should squelch other derived errors). Occurs
67 /// when, e.g., `'_` is used in the wrong place.
72 pub fn ident(&self) -> Ident {
74 ParamName::Plain(ident) => ident,
75 ParamName::Fresh | ParamName::Error => Ident::with_dummy_span(kw::UnderscoreLifetime),
79 pub fn normalize_to_macros_2_0(&self) -> ParamName {
81 ParamName::Plain(ident) => ParamName::Plain(ident.normalize_to_macros_2_0()),
82 param_name => param_name,
87 #[derive(Debug, Clone, PartialEq, Eq, Encodable, Hash, Copy)]
88 #[derive(HashStable_Generic)]
89 pub enum LifetimeName {
90 /// User-given names or fresh (synthetic) names.
91 Param(LocalDefId, ParamName),
93 /// Implicit lifetime in a context like `dyn Foo`. This is
94 /// distinguished from implicit lifetimes elsewhere because the
95 /// lifetime that they default to must appear elsewhere within the
96 /// enclosing type. This means that, in an `impl Trait` context, we
97 /// don't have to create a parameter for them. That is, `impl
98 /// Trait<Item = &u32>` expands to an opaque type like `type
99 /// Foo<'a> = impl Trait<Item = &'a u32>`, but `impl Trait<item =
100 /// dyn Bar>` expands to `type Foo = impl Trait<Item = dyn Bar +
101 /// 'static>`. The latter uses `ImplicitObjectLifetimeDefault` so
102 /// that surrounding code knows not to create a lifetime
104 ImplicitObjectLifetimeDefault,
106 /// Indicates an error during lowering (usually `'_` in wrong place)
107 /// that was already reported.
110 /// User wrote an anonymous lifetime, either `'_` or nothing.
111 /// The semantics of this lifetime should be inferred by typechecking code.
114 /// User wrote `'static`.
119 pub fn ident(&self) -> Ident {
121 LifetimeName::ImplicitObjectLifetimeDefault | LifetimeName::Error => Ident::empty(),
122 LifetimeName::Infer => Ident::with_dummy_span(kw::UnderscoreLifetime),
123 LifetimeName::Static => Ident::with_dummy_span(kw::StaticLifetime),
124 LifetimeName::Param(_, param_name) => param_name.ident(),
128 pub fn is_anonymous(&self) -> bool {
130 LifetimeName::ImplicitObjectLifetimeDefault
131 | LifetimeName::Infer
132 | LifetimeName::Param(_, ParamName::Fresh)
133 | LifetimeName::Error => true,
134 LifetimeName::Static | LifetimeName::Param(..) => false,
138 pub fn is_elided(&self) -> bool {
140 LifetimeName::ImplicitObjectLifetimeDefault | LifetimeName::Infer => true,
142 // It might seem surprising that `Fresh` counts as
143 // *not* elided -- but this is because, as far as the code
144 // in the compiler is concerned -- `Fresh` variants act
145 // equivalently to "some fresh name". They correspond to
146 // early-bound regions on an impl, in other words.
147 LifetimeName::Error | LifetimeName::Param(..) | LifetimeName::Static => false,
151 fn is_static(&self) -> bool {
152 self == &LifetimeName::Static
155 pub fn normalize_to_macros_2_0(&self) -> LifetimeName {
157 LifetimeName::Param(def_id, param_name) => {
158 LifetimeName::Param(def_id, param_name.normalize_to_macros_2_0())
160 lifetime_name => lifetime_name,
165 impl fmt::Display for Lifetime {
166 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
167 self.name.ident().fmt(f)
172 pub fn is_elided(&self) -> bool {
173 self.name.is_elided()
176 pub fn is_static(&self) -> bool {
177 self.name.is_static()
181 /// A `Path` is essentially Rust's notion of a name; for instance,
182 /// `std::cmp::PartialEq`. It's represented as a sequence of identifiers,
183 /// along with a bunch of supporting information.
184 #[derive(Debug, HashStable_Generic)]
185 pub struct Path<'hir> {
187 /// The resolution for the path.
189 /// The segments in the path: the things separated by `::`.
190 pub segments: &'hir [PathSegment<'hir>],
194 pub fn is_global(&self) -> bool {
195 !self.segments.is_empty() && self.segments[0].ident.name == kw::PathRoot
199 /// A segment of a path: an identifier, an optional lifetime, and a set of
201 #[derive(Debug, HashStable_Generic)]
202 pub struct PathSegment<'hir> {
203 /// The identifier portion of this path segment.
205 // `id` and `res` are optional. We currently only use these in save-analysis,
206 // any path segments without these will not have save-analysis info and
207 // therefore will not have 'jump to def' in IDEs, but otherwise will not be
208 // affected. (In general, we don't bother to get the defs for synthesized
209 // segments, only for segments which have come from the AST).
210 pub hir_id: Option<HirId>,
211 pub res: Option<Res>,
213 /// Type/lifetime parameters attached to this path. They come in
214 /// two flavors: `Path<A,B,C>` and `Path(A,B) -> C`. Note that
215 /// this is more than just simple syntactic sugar; the use of
216 /// parens affects the region binding rules, so we preserve the
218 pub args: Option<&'hir GenericArgs<'hir>>,
220 /// Whether to infer remaining type parameters, if any.
221 /// This only applies to expression and pattern paths, and
222 /// out of those only the segments with no type parameters
223 /// to begin with, e.g., `Vec::new` is `<Vec<..>>::new::<..>`.
224 pub infer_args: bool,
227 impl<'hir> PathSegment<'hir> {
228 /// Converts an identifier to the corresponding segment.
229 pub fn from_ident(ident: Ident) -> PathSegment<'hir> {
230 PathSegment { ident, hir_id: None, res: None, infer_args: true, args: None }
233 pub fn invalid() -> Self {
234 Self::from_ident(Ident::empty())
237 pub fn args(&self) -> &GenericArgs<'hir> {
238 if let Some(ref args) = self.args {
241 const DUMMY: &GenericArgs<'_> = &GenericArgs::none();
247 #[derive(Encodable, Debug, HashStable_Generic)]
248 pub struct ConstArg {
249 pub value: AnonConst,
253 #[derive(Encodable, Debug, HashStable_Generic)]
254 pub struct InferArg {
260 pub fn to_ty(&self) -> Ty<'_> {
261 Ty { kind: TyKind::Infer, span: self.span, hir_id: self.hir_id }
265 #[derive(Debug, HashStable_Generic)]
266 pub enum GenericArg<'hir> {
273 impl GenericArg<'_> {
274 pub fn span(&self) -> Span {
276 GenericArg::Lifetime(l) => l.span,
277 GenericArg::Type(t) => t.span,
278 GenericArg::Const(c) => c.span,
279 GenericArg::Infer(i) => i.span,
283 pub fn id(&self) -> HirId {
285 GenericArg::Lifetime(l) => l.hir_id,
286 GenericArg::Type(t) => t.hir_id,
287 GenericArg::Const(c) => c.value.hir_id,
288 GenericArg::Infer(i) => i.hir_id,
292 pub fn is_synthetic(&self) -> bool {
293 matches!(self, GenericArg::Lifetime(lifetime) if lifetime.name.ident() == Ident::empty())
296 pub fn descr(&self) -> &'static str {
298 GenericArg::Lifetime(_) => "lifetime",
299 GenericArg::Type(_) => "type",
300 GenericArg::Const(_) => "constant",
301 GenericArg::Infer(_) => "inferred",
305 pub fn to_ord(&self) -> ast::ParamKindOrd {
307 GenericArg::Lifetime(_) => ast::ParamKindOrd::Lifetime,
308 GenericArg::Type(_) => ast::ParamKindOrd::Type,
309 GenericArg::Const(_) => ast::ParamKindOrd::Const,
310 GenericArg::Infer(_) => ast::ParamKindOrd::Infer,
314 pub fn is_ty_or_const(&self) -> bool {
316 GenericArg::Lifetime(_) => false,
317 GenericArg::Type(_) | GenericArg::Const(_) | GenericArg::Infer(_) => true,
322 #[derive(Debug, HashStable_Generic)]
323 pub struct GenericArgs<'hir> {
324 /// The generic arguments for this path segment.
325 pub args: &'hir [GenericArg<'hir>],
326 /// Bindings (equality constraints) on associated types, if present.
327 /// E.g., `Foo<A = Bar>`.
328 pub bindings: &'hir [TypeBinding<'hir>],
329 /// Were arguments written in parenthesized form `Fn(T) -> U`?
330 /// This is required mostly for pretty-printing and diagnostics,
331 /// but also for changing lifetime elision rules to be "function-like".
332 pub parenthesized: bool,
333 /// The span encompassing arguments and the surrounding brackets `<>` or `()`
334 /// Foo<A, B, AssocTy = D> Fn(T, U, V) -> W
335 /// ^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^
336 /// Note that this may be:
337 /// - empty, if there are no generic brackets (but there may be hidden lifetimes)
338 /// - dummy, if this was generated while desugaring
342 impl<'hir> GenericArgs<'hir> {
343 pub const fn none() -> Self {
344 Self { args: &[], bindings: &[], parenthesized: false, span_ext: DUMMY_SP }
347 pub fn inputs(&self) -> &[Ty<'hir>] {
348 if self.parenthesized {
349 for arg in self.args {
351 GenericArg::Lifetime(_) => {}
352 GenericArg::Type(ref ty) => {
353 if let TyKind::Tup(ref tys) = ty.kind {
358 GenericArg::Const(_) => {}
359 GenericArg::Infer(_) => {}
363 panic!("GenericArgs::inputs: not a `Fn(T) -> U`");
367 pub fn has_type_params(&self) -> bool {
368 self.args.iter().any(|arg| matches!(arg, GenericArg::Type(_)))
371 pub fn has_err(&self) -> bool {
372 self.args.iter().any(|arg| match arg {
373 GenericArg::Type(ty) => matches!(ty.kind, TyKind::Err),
375 }) || self.bindings.iter().any(|arg| match arg.kind {
376 TypeBindingKind::Equality { term: Term::Ty(ty) } => matches!(ty.kind, TyKind::Err),
382 pub fn num_type_params(&self) -> usize {
383 self.args.iter().filter(|arg| matches!(arg, GenericArg::Type(_))).count()
387 pub fn num_lifetime_params(&self) -> usize {
388 self.args.iter().filter(|arg| matches!(arg, GenericArg::Lifetime(_))).count()
392 pub fn has_lifetime_params(&self) -> bool {
393 self.args.iter().any(|arg| matches!(arg, GenericArg::Lifetime(_)))
397 pub fn num_generic_params(&self) -> usize {
398 self.args.iter().filter(|arg| !matches!(arg, GenericArg::Lifetime(_))).count()
401 /// The span encompassing the text inside the surrounding brackets.
402 /// It will also include bindings if they aren't in the form `-> Ret`
403 /// Returns `None` if the span is empty (e.g. no brackets) or dummy
404 pub fn span(&self) -> Option<Span> {
405 let span_ext = self.span_ext()?;
406 Some(span_ext.with_lo(span_ext.lo() + BytePos(1)).with_hi(span_ext.hi() - BytePos(1)))
409 /// Returns span encompassing arguments and their surrounding `<>` or `()`
410 pub fn span_ext(&self) -> Option<Span> {
411 Some(self.span_ext).filter(|span| !span.is_empty())
414 pub fn is_empty(&self) -> bool {
419 /// A modifier on a bound, currently this is only used for `?Sized`, where the
420 /// modifier is `Maybe`. Negative bounds should also be handled here.
421 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Hash, Debug)]
422 #[derive(HashStable_Generic)]
423 pub enum TraitBoundModifier {
429 /// The AST represents all type param bounds as types.
430 /// `typeck::collect::compute_bounds` matches these against
431 /// the "special" built-in traits (see `middle::lang_items`) and
432 /// detects `Copy`, `Send` and `Sync`.
433 #[derive(Clone, Debug, HashStable_Generic)]
434 pub enum GenericBound<'hir> {
435 Trait(PolyTraitRef<'hir>, TraitBoundModifier),
436 // FIXME(davidtwco): Introduce `PolyTraitRef::LangItem`
437 LangItemTrait(LangItem, Span, HirId, &'hir GenericArgs<'hir>),
441 impl GenericBound<'_> {
442 pub fn trait_ref(&self) -> Option<&TraitRef<'_>> {
444 GenericBound::Trait(data, _) => Some(&data.trait_ref),
449 pub fn span(&self) -> Span {
451 GenericBound::Trait(t, ..) => t.span,
452 GenericBound::LangItemTrait(_, span, ..) => *span,
453 GenericBound::Outlives(l) => l.span,
458 pub type GenericBounds<'hir> = &'hir [GenericBound<'hir>];
460 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Debug, HashStable_Generic)]
461 pub enum LifetimeParamKind {
462 // Indicates that the lifetime definition was explicitly declared (e.g., in
463 // `fn foo<'a>(x: &'a u8) -> &'a u8 { x }`).
466 // Indication that the lifetime was elided (e.g., in both cases in
467 // `fn foo(x: &u8) -> &'_ u8 { x }`).
470 // Indication that the lifetime name was somehow in error.
474 #[derive(Debug, HashStable_Generic)]
475 pub enum GenericParamKind<'hir> {
476 /// A lifetime definition (e.g., `'a: 'b + 'c + 'd`).
478 kind: LifetimeParamKind,
481 default: Option<&'hir Ty<'hir>>,
486 /// Optional default value for the const generic param
487 default: Option<AnonConst>,
491 #[derive(Debug, HashStable_Generic)]
492 pub struct GenericParam<'hir> {
496 pub pure_wrt_drop: bool,
497 pub kind: GenericParamKind<'hir>,
498 pub colon_span: Option<Span>,
501 impl<'hir> GenericParam<'hir> {
502 /// Synthetic type-parameters are inserted after normal ones.
503 /// In order for normal parameters to be able to refer to synthetic ones,
504 /// scans them first.
505 pub fn is_impl_trait(&self) -> bool {
506 matches!(self.kind, GenericParamKind::Type { synthetic: true, .. })
509 /// This can happen for `async fn`, e.g. `async fn f<'_>(&'_ self)`.
511 /// See `lifetime_to_generic_param` in `rustc_ast_lowering` for more information.
512 pub fn is_elided_lifetime(&self) -> bool {
513 matches!(self.kind, GenericParamKind::Lifetime { kind: LifetimeParamKind::Elided })
518 pub struct GenericParamCount {
519 pub lifetimes: usize,
525 /// Represents lifetimes and type parameters attached to a declaration
526 /// of a function, enum, trait, etc.
527 #[derive(Debug, HashStable_Generic)]
528 pub struct Generics<'hir> {
529 pub params: &'hir [GenericParam<'hir>],
530 pub predicates: &'hir [WherePredicate<'hir>],
531 pub has_where_clause_predicates: bool,
532 pub where_clause_span: Span,
536 impl<'hir> Generics<'hir> {
537 pub const fn empty() -> &'hir Generics<'hir> {
538 const NOPE: Generics<'_> = Generics {
541 has_where_clause_predicates: false,
542 where_clause_span: DUMMY_SP,
548 pub fn get_named(&self, name: Symbol) -> Option<&GenericParam<'hir>> {
549 for param in self.params {
550 if name == param.name.ident().name {
557 pub fn spans(&self) -> MultiSpan {
558 if self.params.is_empty() {
561 self.params.iter().map(|p| p.span).collect::<Vec<Span>>().into()
565 /// If there are generic parameters, return where to introduce a new one.
566 pub fn span_for_param_suggestion(&self) -> Option<Span> {
567 if self.params.iter().any(|p| self.span.contains(p.span)) {
568 // `fn foo<A>(t: impl Trait)`
569 // ^ suggest `, T: Trait` here
570 let span = self.span.with_lo(self.span.hi() - BytePos(1)).shrink_to_lo();
577 /// `Span` where further predicates would be suggested, accounting for trailing commas, like
578 /// in `fn foo<T>(t: T) where T: Foo,` so we don't suggest two trailing commas.
579 pub fn tail_span_for_predicate_suggestion(&self) -> Span {
580 let end = self.where_clause_span.shrink_to_hi();
581 if self.has_where_clause_predicates {
584 .filter(|p| p.in_where_clause())
586 .map_or(end, |p| p.span())
594 pub fn add_where_or_trailing_comma(&self) -> &'static str {
595 if self.has_where_clause_predicates {
597 } else if self.where_clause_span.is_empty() {
600 // No where clause predicates, but we have `where` token
605 pub fn bounds_for_param(
607 param_def_id: LocalDefId,
608 ) -> impl Iterator<Item = &WhereBoundPredicate<'hir>> {
609 self.predicates.iter().filter_map(move |pred| match pred {
610 WherePredicate::BoundPredicate(bp) if bp.is_param_bound(param_def_id.to_def_id()) => {
617 pub fn outlives_for_param(
619 param_def_id: LocalDefId,
620 ) -> impl Iterator<Item = &WhereRegionPredicate<'_>> {
621 self.predicates.iter().filter_map(move |pred| match pred {
622 WherePredicate::RegionPredicate(rp) if rp.is_param_bound(param_def_id) => Some(rp),
627 pub fn bounds_span_for_suggestions(&self, param_def_id: LocalDefId) -> Option<Span> {
628 self.bounds_for_param(param_def_id).flat_map(|bp| bp.bounds.iter().rev()).find_map(
630 // We include bounds that come from a `#[derive(_)]` but point at the user's code,
631 // as we use this method to get a span appropriate for suggestions.
632 let bs = bound.span();
633 if bs.can_be_used_for_suggestions() { Some(bs.shrink_to_hi()) } else { None }
638 pub fn span_for_predicate_removal(&self, pos: usize) -> Span {
639 let predicate = &self.predicates[pos];
640 let span = predicate.span();
642 if !predicate.in_where_clause() {
648 // We need to find out which comma to remove.
649 if pos < self.predicates.len() - 1 {
650 let next_pred = &self.predicates[pos + 1];
651 if next_pred.in_where_clause() {
652 // where T: ?Sized, Foo: Bar,
654 return span.until(next_pred.span());
659 let prev_pred = &self.predicates[pos - 1];
660 if prev_pred.in_where_clause() {
661 // where Foo: Bar, T: ?Sized,
663 return prev_pred.span().shrink_to_hi().to(span);
667 // This is the only predicate in the where clause.
670 self.where_clause_span
673 pub fn span_for_bound_removal(&self, predicate_pos: usize, bound_pos: usize) -> Span {
674 let predicate = &self.predicates[predicate_pos];
675 let bounds = predicate.bounds();
677 if bounds.len() == 1 {
678 return self.span_for_predicate_removal(predicate_pos);
681 let span = bounds[bound_pos].span();
683 // where T: ?Sized + Bar, Foo: Bar,
685 span.to(bounds[1].span().shrink_to_lo())
687 // where T: Bar + ?Sized, Foo: Bar,
689 bounds[bound_pos - 1].span().shrink_to_hi().to(span)
694 /// A single predicate in a where-clause.
695 #[derive(Debug, HashStable_Generic)]
696 pub enum WherePredicate<'hir> {
697 /// A type binding (e.g., `for<'c> Foo: Send + Clone + 'c`).
698 BoundPredicate(WhereBoundPredicate<'hir>),
699 /// A lifetime predicate (e.g., `'a: 'b + 'c`).
700 RegionPredicate(WhereRegionPredicate<'hir>),
701 /// An equality predicate (unsupported).
702 EqPredicate(WhereEqPredicate<'hir>),
705 impl<'hir> WherePredicate<'hir> {
706 pub fn span(&self) -> Span {
708 WherePredicate::BoundPredicate(p) => p.span,
709 WherePredicate::RegionPredicate(p) => p.span,
710 WherePredicate::EqPredicate(p) => p.span,
714 pub fn in_where_clause(&self) -> bool {
716 WherePredicate::BoundPredicate(p) => p.origin == PredicateOrigin::WhereClause,
717 WherePredicate::RegionPredicate(p) => p.in_where_clause,
718 WherePredicate::EqPredicate(_) => false,
722 pub fn bounds(&self) -> GenericBounds<'hir> {
724 WherePredicate::BoundPredicate(p) => p.bounds,
725 WherePredicate::RegionPredicate(p) => p.bounds,
726 WherePredicate::EqPredicate(_) => &[],
731 #[derive(Copy, Clone, Debug, HashStable_Generic, PartialEq, Eq)]
732 pub enum PredicateOrigin {
738 /// A type bound (e.g., `for<'c> Foo: Send + Clone + 'c`).
739 #[derive(Debug, HashStable_Generic)]
740 pub struct WhereBoundPredicate<'hir> {
742 /// Origin of the predicate.
743 pub origin: PredicateOrigin,
744 /// Any generics from a `for` binding.
745 pub bound_generic_params: &'hir [GenericParam<'hir>],
746 /// The type being bounded.
747 pub bounded_ty: &'hir Ty<'hir>,
748 /// Trait and lifetime bounds (e.g., `Clone + Send + 'static`).
749 pub bounds: GenericBounds<'hir>,
752 impl<'hir> WhereBoundPredicate<'hir> {
753 /// Returns `true` if `param_def_id` matches the `bounded_ty` of this predicate.
754 pub fn is_param_bound(&self, param_def_id: DefId) -> bool {
755 self.bounded_ty.as_generic_param().map_or(false, |(def_id, _)| def_id == param_def_id)
759 /// A lifetime predicate (e.g., `'a: 'b + 'c`).
760 #[derive(Debug, HashStable_Generic)]
761 pub struct WhereRegionPredicate<'hir> {
763 pub in_where_clause: bool,
764 pub lifetime: Lifetime,
765 pub bounds: GenericBounds<'hir>,
768 impl<'hir> WhereRegionPredicate<'hir> {
769 /// Returns `true` if `param_def_id` matches the `lifetime` of this predicate.
770 pub fn is_param_bound(&self, param_def_id: LocalDefId) -> bool {
771 match self.lifetime.name {
772 LifetimeName::Param(id, _) => id == param_def_id,
778 /// An equality predicate (e.g., `T = int`); currently unsupported.
779 #[derive(Debug, HashStable_Generic)]
780 pub struct WhereEqPredicate<'hir> {
783 pub lhs_ty: &'hir Ty<'hir>,
784 pub rhs_ty: &'hir Ty<'hir>,
787 /// HIR node coupled with its parent's id in the same HIR owner.
789 /// The parent is trash when the node is a HIR owner.
790 #[derive(Clone, Debug)]
791 pub struct ParentedNode<'tcx> {
792 pub parent: ItemLocalId,
793 pub node: Node<'tcx>,
796 /// Attributes owned by a HIR owner.
798 pub struct AttributeMap<'tcx> {
799 pub map: SortedMap<ItemLocalId, &'tcx [Attribute]>,
800 pub hash: Fingerprint,
803 impl<'tcx> AttributeMap<'tcx> {
804 pub const EMPTY: &'static AttributeMap<'static> =
805 &AttributeMap { map: SortedMap::new(), hash: Fingerprint::ZERO };
808 pub fn get(&self, id: ItemLocalId) -> &'tcx [Attribute] {
809 self.map.get(&id).copied().unwrap_or(&[])
813 /// Map of all HIR nodes inside the current owner.
814 /// These nodes are mapped by `ItemLocalId` alongside the index of their parent node.
815 /// The HIR tree, including bodies, is pre-hashed.
816 pub struct OwnerNodes<'tcx> {
817 /// Pre-computed hash of the full HIR.
818 pub hash_including_bodies: Fingerprint,
819 /// Pre-computed hash of the item signature, sithout recursing into the body.
820 pub hash_without_bodies: Fingerprint,
821 /// Full HIR for the current owner.
822 // The zeroth node's parent should never be accessed: the owner's parent is computed by the
823 // hir_owner_parent query. It is set to `ItemLocalId::INVALID` to force an ICE if accidentally
825 pub nodes: IndexVec<ItemLocalId, Option<ParentedNode<'tcx>>>,
826 /// Content of local bodies.
827 pub bodies: SortedMap<ItemLocalId, &'tcx Body<'tcx>>,
828 /// Non-owning definitions contained in this owner.
829 pub local_id_to_def_id: SortedMap<ItemLocalId, LocalDefId>,
832 impl<'tcx> OwnerNodes<'tcx> {
833 pub fn node(&self) -> OwnerNode<'tcx> {
834 use rustc_index::vec::Idx;
835 let node = self.nodes[ItemLocalId::new(0)].as_ref().unwrap().node;
836 let node = node.as_owner().unwrap(); // Indexing must ensure it is an OwnerNode.
841 impl fmt::Debug for OwnerNodes<'_> {
842 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
843 f.debug_struct("OwnerNodes")
844 .field("node", &self.nodes[ItemLocalId::from_u32(0)])
845 .field("bodies", &self.bodies)
846 .field("local_id_to_def_id", &self.local_id_to_def_id)
847 .field("hash_without_bodies", &self.hash_without_bodies)
848 .field("hash_including_bodies", &self.hash_including_bodies)
853 /// Full information resulting from lowering an AST node.
854 #[derive(Debug, HashStable_Generic)]
855 pub struct OwnerInfo<'hir> {
856 /// Contents of the HIR.
857 pub nodes: OwnerNodes<'hir>,
858 /// Map from each nested owner to its parent's local id.
859 pub parenting: FxHashMap<LocalDefId, ItemLocalId>,
860 /// Collected attributes of the HIR nodes.
861 pub attrs: AttributeMap<'hir>,
862 /// Map indicating what traits are in scope for places where this
863 /// is relevant; generated by resolve.
864 pub trait_map: FxHashMap<ItemLocalId, Box<[TraitCandidate]>>,
867 impl<'tcx> OwnerInfo<'tcx> {
869 pub fn node(&self) -> OwnerNode<'tcx> {
874 #[derive(Copy, Clone, Debug, HashStable_Generic)]
875 pub enum MaybeOwner<T> {
878 /// Used as a placeholder for unused LocalDefId.
882 impl<T> MaybeOwner<T> {
883 pub fn as_owner(self) -> Option<T> {
885 MaybeOwner::Owner(i) => Some(i),
886 MaybeOwner::NonOwner(_) | MaybeOwner::Phantom => None,
890 pub fn map<U>(self, f: impl FnOnce(T) -> U) -> MaybeOwner<U> {
892 MaybeOwner::Owner(i) => MaybeOwner::Owner(f(i)),
893 MaybeOwner::NonOwner(hir_id) => MaybeOwner::NonOwner(hir_id),
894 MaybeOwner::Phantom => MaybeOwner::Phantom,
898 pub fn unwrap(self) -> T {
900 MaybeOwner::Owner(i) => i,
901 MaybeOwner::NonOwner(_) | MaybeOwner::Phantom => panic!("Not a HIR owner"),
906 /// The top-level data structure that stores the entire contents of
907 /// the crate currently being compiled.
909 /// For more details, see the [rustc dev guide].
911 /// [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/hir.html
913 pub struct Crate<'hir> {
914 pub owners: IndexVec<LocalDefId, MaybeOwner<&'hir OwnerInfo<'hir>>>,
915 pub hir_hash: Fingerprint,
918 #[derive(Debug, HashStable_Generic)]
919 pub struct Closure<'hir> {
920 pub binder: ClosureBinder,
921 pub capture_clause: CaptureBy,
922 pub bound_generic_params: &'hir [GenericParam<'hir>],
923 pub fn_decl: &'hir FnDecl<'hir>,
925 pub fn_decl_span: Span,
926 pub movability: Option<Movability>,
929 /// A block of statements `{ .. }`, which may have a label (in this case the
930 /// `targeted_by_break` field will be `true`) and may be `unsafe` by means of
931 /// the `rules` being anything but `DefaultBlock`.
932 #[derive(Debug, HashStable_Generic)]
933 pub struct Block<'hir> {
934 /// Statements in a block.
935 pub stmts: &'hir [Stmt<'hir>],
936 /// An expression at the end of the block
937 /// without a semicolon, if any.
938 pub expr: Option<&'hir Expr<'hir>>,
939 #[stable_hasher(ignore)]
941 /// Distinguishes between `unsafe { ... }` and `{ ... }`.
942 pub rules: BlockCheckMode,
944 /// If true, then there may exist `break 'a` values that aim to
945 /// break out of this block early.
946 /// Used by `'label: {}` blocks and by `try {}` blocks.
947 pub targeted_by_break: bool,
950 impl<'hir> Block<'hir> {
951 pub fn innermost_block(&self) -> &Block<'hir> {
952 let mut block = self;
953 while let Some(Expr { kind: ExprKind::Block(inner_block, _), .. }) = block.expr {
960 #[derive(Debug, HashStable_Generic)]
961 pub struct Pat<'hir> {
962 #[stable_hasher(ignore)]
964 pub kind: PatKind<'hir>,
966 // Whether to use default binding modes.
967 // At present, this is false only for destructuring assignment.
968 pub default_binding_modes: bool,
971 impl<'hir> Pat<'hir> {
972 // FIXME(#19596) this is a workaround, but there should be a better way
973 fn walk_short_(&self, it: &mut impl FnMut(&Pat<'hir>) -> bool) -> bool {
980 Wild | Lit(_) | Range(..) | Binding(.., None) | Path(_) => true,
981 Box(s) | Ref(s, _) | Binding(.., Some(s)) => s.walk_short_(it),
982 Struct(_, fields, _) => fields.iter().all(|field| field.pat.walk_short_(it)),
983 TupleStruct(_, s, _) | Tuple(s, _) | Or(s) => s.iter().all(|p| p.walk_short_(it)),
984 Slice(before, slice, after) => {
985 before.iter().chain(slice).chain(after.iter()).all(|p| p.walk_short_(it))
990 /// Walk the pattern in left-to-right order,
991 /// short circuiting (with `.all(..)`) if `false` is returned.
993 /// Note that when visiting e.g. `Tuple(ps)`,
994 /// if visiting `ps[0]` returns `false`,
995 /// then `ps[1]` will not be visited.
996 pub fn walk_short(&self, mut it: impl FnMut(&Pat<'hir>) -> bool) -> bool {
997 self.walk_short_(&mut it)
1000 // FIXME(#19596) this is a workaround, but there should be a better way
1001 fn walk_(&self, it: &mut impl FnMut(&Pat<'hir>) -> bool) {
1008 Wild | Lit(_) | Range(..) | Binding(.., None) | Path(_) => {}
1009 Box(s) | Ref(s, _) | Binding(.., Some(s)) => s.walk_(it),
1010 Struct(_, fields, _) => fields.iter().for_each(|field| field.pat.walk_(it)),
1011 TupleStruct(_, s, _) | Tuple(s, _) | Or(s) => s.iter().for_each(|p| p.walk_(it)),
1012 Slice(before, slice, after) => {
1013 before.iter().chain(slice).chain(after.iter()).for_each(|p| p.walk_(it))
1018 /// Walk the pattern in left-to-right order.
1020 /// If `it(pat)` returns `false`, the children are not visited.
1021 pub fn walk(&self, mut it: impl FnMut(&Pat<'hir>) -> bool) {
1025 /// Walk the pattern in left-to-right order.
1027 /// If you always want to recurse, prefer this method over `walk`.
1028 pub fn walk_always(&self, mut it: impl FnMut(&Pat<'_>)) {
1036 /// A single field in a struct pattern.
1038 /// Patterns like the fields of Foo `{ x, ref y, ref mut z }`
1039 /// are treated the same as` x: x, y: ref y, z: ref mut z`,
1040 /// except `is_shorthand` is true.
1041 #[derive(Debug, HashStable_Generic)]
1042 pub struct PatField<'hir> {
1043 #[stable_hasher(ignore)]
1045 /// The identifier for the field.
1047 /// The pattern the field is destructured to.
1048 pub pat: &'hir Pat<'hir>,
1049 pub is_shorthand: bool,
1053 /// Explicit binding annotations given in the HIR for a binding. Note
1054 /// that this is not the final binding *mode* that we infer after type
1056 #[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]
1057 pub enum BindingAnnotation {
1058 /// No binding annotation given: this means that the final binding mode
1059 /// will depend on whether we have skipped through a `&` reference
1060 /// when matching. For example, the `x` in `Some(x)` will have binding
1061 /// mode `None`; if you do `let Some(x) = &Some(22)`, it will
1062 /// ultimately be inferred to be by-reference.
1064 /// Note that implicit reference skipping is not implemented yet (#42640).
1067 /// Annotated with `mut x` -- could be either ref or not, similar to `None`.
1070 /// Annotated as `ref`, like `ref x`
1073 /// Annotated as `ref mut x`.
1077 #[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]
1083 impl fmt::Display for RangeEnd {
1084 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1085 f.write_str(match self {
1086 RangeEnd::Included => "..=",
1087 RangeEnd::Excluded => "..",
1092 #[derive(Debug, HashStable_Generic)]
1093 pub enum PatKind<'hir> {
1094 /// Represents a wildcard pattern (i.e., `_`).
1097 /// A fresh binding `ref mut binding @ OPT_SUBPATTERN`.
1098 /// The `HirId` is the canonical ID for the variable being bound,
1099 /// (e.g., in `Ok(x) | Err(x)`, both `x` use the same canonical ID),
1100 /// which is the pattern ID of the first `x`.
1101 Binding(BindingAnnotation, HirId, Ident, Option<&'hir Pat<'hir>>),
1103 /// A struct or struct variant pattern (e.g., `Variant {x, y, ..}`).
1104 /// The `bool` is `true` in the presence of a `..`.
1105 Struct(QPath<'hir>, &'hir [PatField<'hir>], bool),
1107 /// A tuple struct/variant pattern `Variant(x, y, .., z)`.
1108 /// If the `..` pattern fragment is present, then `Option<usize>` denotes its position.
1109 /// `0 <= position <= subpats.len()`
1110 TupleStruct(QPath<'hir>, &'hir [Pat<'hir>], Option<usize>),
1112 /// An or-pattern `A | B | C`.
1113 /// Invariant: `pats.len() >= 2`.
1114 Or(&'hir [Pat<'hir>]),
1116 /// A path pattern for a unit struct/variant or a (maybe-associated) constant.
1119 /// A tuple pattern (e.g., `(a, b)`).
1120 /// If the `..` pattern fragment is present, then `Option<usize>` denotes its position.
1121 /// `0 <= position <= subpats.len()`
1122 Tuple(&'hir [Pat<'hir>], Option<usize>),
1124 /// A `box` pattern.
1125 Box(&'hir Pat<'hir>),
1127 /// A reference pattern (e.g., `&mut (a, b)`).
1128 Ref(&'hir Pat<'hir>, Mutability),
1131 Lit(&'hir Expr<'hir>),
1133 /// A range pattern (e.g., `1..=2` or `1..2`).
1134 Range(Option<&'hir Expr<'hir>>, Option<&'hir Expr<'hir>>, RangeEnd),
1136 /// A slice pattern, `[before_0, ..., before_n, (slice, after_0, ..., after_n)?]`.
1138 /// Here, `slice` is lowered from the syntax `($binding_mode $ident @)? ..`.
1139 /// If `slice` exists, then `after` can be non-empty.
1141 /// The representation for e.g., `[a, b, .., c, d]` is:
1142 /// ```ignore (illustrative)
1143 /// PatKind::Slice([Binding(a), Binding(b)], Some(Wild), [Binding(c), Binding(d)])
1145 Slice(&'hir [Pat<'hir>], Option<&'hir Pat<'hir>>, &'hir [Pat<'hir>]),
1148 #[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]
1149 pub enum BinOpKind {
1150 /// The `+` operator (addition).
1152 /// The `-` operator (subtraction).
1154 /// The `*` operator (multiplication).
1156 /// The `/` operator (division).
1158 /// The `%` operator (modulus).
1160 /// The `&&` operator (logical and).
1162 /// The `||` operator (logical or).
1164 /// The `^` operator (bitwise xor).
1166 /// The `&` operator (bitwise and).
1168 /// The `|` operator (bitwise or).
1170 /// The `<<` operator (shift left).
1172 /// The `>>` operator (shift right).
1174 /// The `==` operator (equality).
1176 /// The `<` operator (less than).
1178 /// The `<=` operator (less than or equal to).
1180 /// The `!=` operator (not equal to).
1182 /// The `>=` operator (greater than or equal to).
1184 /// The `>` operator (greater than).
1189 pub fn as_str(self) -> &'static str {
1191 BinOpKind::Add => "+",
1192 BinOpKind::Sub => "-",
1193 BinOpKind::Mul => "*",
1194 BinOpKind::Div => "/",
1195 BinOpKind::Rem => "%",
1196 BinOpKind::And => "&&",
1197 BinOpKind::Or => "||",
1198 BinOpKind::BitXor => "^",
1199 BinOpKind::BitAnd => "&",
1200 BinOpKind::BitOr => "|",
1201 BinOpKind::Shl => "<<",
1202 BinOpKind::Shr => ">>",
1203 BinOpKind::Eq => "==",
1204 BinOpKind::Lt => "<",
1205 BinOpKind::Le => "<=",
1206 BinOpKind::Ne => "!=",
1207 BinOpKind::Ge => ">=",
1208 BinOpKind::Gt => ">",
1212 pub fn is_lazy(self) -> bool {
1213 matches!(self, BinOpKind::And | BinOpKind::Or)
1216 pub fn is_shift(self) -> bool {
1217 matches!(self, BinOpKind::Shl | BinOpKind::Shr)
1220 pub fn is_comparison(self) -> bool {
1227 | BinOpKind::Ge => true,
1239 | BinOpKind::Shr => false,
1243 /// Returns `true` if the binary operator takes its arguments by value.
1244 pub fn is_by_value(self) -> bool {
1245 !self.is_comparison()
1249 impl Into<ast::BinOpKind> for BinOpKind {
1250 fn into(self) -> ast::BinOpKind {
1252 BinOpKind::Add => ast::BinOpKind::Add,
1253 BinOpKind::Sub => ast::BinOpKind::Sub,
1254 BinOpKind::Mul => ast::BinOpKind::Mul,
1255 BinOpKind::Div => ast::BinOpKind::Div,
1256 BinOpKind::Rem => ast::BinOpKind::Rem,
1257 BinOpKind::And => ast::BinOpKind::And,
1258 BinOpKind::Or => ast::BinOpKind::Or,
1259 BinOpKind::BitXor => ast::BinOpKind::BitXor,
1260 BinOpKind::BitAnd => ast::BinOpKind::BitAnd,
1261 BinOpKind::BitOr => ast::BinOpKind::BitOr,
1262 BinOpKind::Shl => ast::BinOpKind::Shl,
1263 BinOpKind::Shr => ast::BinOpKind::Shr,
1264 BinOpKind::Eq => ast::BinOpKind::Eq,
1265 BinOpKind::Lt => ast::BinOpKind::Lt,
1266 BinOpKind::Le => ast::BinOpKind::Le,
1267 BinOpKind::Ne => ast::BinOpKind::Ne,
1268 BinOpKind::Ge => ast::BinOpKind::Ge,
1269 BinOpKind::Gt => ast::BinOpKind::Gt,
1274 pub type BinOp = Spanned<BinOpKind>;
1276 #[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]
1278 /// The `*` operator (dereferencing).
1280 /// The `!` operator (logical negation).
1282 /// The `-` operator (negation).
1287 pub fn as_str(self) -> &'static str {
1295 /// Returns `true` if the unary operator takes its argument by value.
1296 pub fn is_by_value(self) -> bool {
1297 matches!(self, Self::Neg | Self::Not)
1302 #[derive(Debug, HashStable_Generic)]
1303 pub struct Stmt<'hir> {
1305 pub kind: StmtKind<'hir>,
1309 /// The contents of a statement.
1310 #[derive(Debug, HashStable_Generic)]
1311 pub enum StmtKind<'hir> {
1312 /// A local (`let`) binding.
1313 Local(&'hir Local<'hir>),
1315 /// An item binding.
1318 /// An expression without a trailing semi-colon (must have unit type).
1319 Expr(&'hir Expr<'hir>),
1321 /// An expression with a trailing semi-colon (may have any type).
1322 Semi(&'hir Expr<'hir>),
1325 /// Represents a `let` statement (i.e., `let <pat>:<ty> = <expr>;`).
1326 #[derive(Debug, HashStable_Generic)]
1327 pub struct Local<'hir> {
1328 pub pat: &'hir Pat<'hir>,
1329 /// Type annotation, if any (otherwise the type will be inferred).
1330 pub ty: Option<&'hir Ty<'hir>>,
1331 /// Initializer expression to set the value, if any.
1332 pub init: Option<&'hir Expr<'hir>>,
1333 /// Else block for a `let...else` binding.
1334 pub els: Option<&'hir Block<'hir>>,
1337 /// Can be `ForLoopDesugar` if the `let` statement is part of a `for` loop
1338 /// desugaring. Otherwise will be `Normal`.
1339 pub source: LocalSource,
1342 /// Represents a single arm of a `match` expression, e.g.
1343 /// `<pat> (if <guard>) => <body>`.
1344 #[derive(Debug, HashStable_Generic)]
1345 pub struct Arm<'hir> {
1346 #[stable_hasher(ignore)]
1349 /// If this pattern and the optional guard matches, then `body` is evaluated.
1350 pub pat: &'hir Pat<'hir>,
1351 /// Optional guard clause.
1352 pub guard: Option<Guard<'hir>>,
1353 /// The expression the arm evaluates to if this arm matches.
1354 pub body: &'hir Expr<'hir>,
1357 /// Represents a `let <pat>[: <ty>] = <expr>` expression (not a Local), occurring in an `if-let` or
1358 /// `let-else`, evaluating to a boolean. Typically the pattern is refutable.
1360 /// In an if-let, imagine it as `if (let <pat> = <expr>) { ... }`; in a let-else, it is part of the
1361 /// desugaring to if-let. Only let-else supports the type annotation at present.
1362 #[derive(Debug, HashStable_Generic)]
1363 pub struct Let<'hir> {
1366 pub pat: &'hir Pat<'hir>,
1367 pub ty: Option<&'hir Ty<'hir>>,
1368 pub init: &'hir Expr<'hir>,
1371 #[derive(Debug, HashStable_Generic)]
1372 pub enum Guard<'hir> {
1373 If(&'hir Expr<'hir>),
1374 IfLet(&'hir Let<'hir>),
1377 impl<'hir> Guard<'hir> {
1378 /// Returns the body of the guard
1380 /// In other words, returns the e in either of the following:
1383 /// - `if let x = e`
1384 pub fn body(&self) -> &'hir Expr<'hir> {
1386 Guard::If(e) | Guard::IfLet(Let { init: e, .. }) => e,
1391 #[derive(Debug, HashStable_Generic)]
1392 pub struct ExprField<'hir> {
1393 #[stable_hasher(ignore)]
1396 pub expr: &'hir Expr<'hir>,
1398 pub is_shorthand: bool,
1401 #[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]
1402 pub enum BlockCheckMode {
1404 UnsafeBlock(UnsafeSource),
1407 #[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]
1408 pub enum UnsafeSource {
1413 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Hash, Debug)]
1418 /// The body of a function, closure, or constant value. In the case of
1419 /// a function, the body contains not only the function body itself
1420 /// (which is an expression), but also the argument patterns, since
1421 /// those are something that the caller doesn't really care about.
1426 /// fn foo((x, y): (u32, u32)) -> u32 {
1431 /// Here, the `Body` associated with `foo()` would contain:
1433 /// - an `params` array containing the `(x, y)` pattern
1434 /// - a `value` containing the `x + y` expression (maybe wrapped in a block)
1435 /// - `generator_kind` would be `None`
1437 /// All bodies have an **owner**, which can be accessed via the HIR
1438 /// map using `body_owner_def_id()`.
1439 #[derive(Debug, HashStable_Generic)]
1440 pub struct Body<'hir> {
1441 pub params: &'hir [Param<'hir>],
1442 pub value: Expr<'hir>,
1443 pub generator_kind: Option<GeneratorKind>,
1446 impl<'hir> Body<'hir> {
1447 pub fn id(&self) -> BodyId {
1448 BodyId { hir_id: self.value.hir_id }
1451 pub fn generator_kind(&self) -> Option<GeneratorKind> {
1456 /// The type of source expression that caused this generator to be created.
1457 #[derive(Clone, PartialEq, PartialOrd, Eq, Hash, Debug, Copy)]
1458 #[derive(HashStable_Generic, Encodable, Decodable)]
1459 pub enum GeneratorKind {
1460 /// An explicit `async` block or the body of an async function.
1461 Async(AsyncGeneratorKind),
1463 /// A generator literal created via a `yield` inside a closure.
1467 impl fmt::Display for GeneratorKind {
1468 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1470 GeneratorKind::Async(k) => fmt::Display::fmt(k, f),
1471 GeneratorKind::Gen => f.write_str("generator"),
1476 impl GeneratorKind {
1477 pub fn descr(&self) -> &'static str {
1479 GeneratorKind::Async(ask) => ask.descr(),
1480 GeneratorKind::Gen => "generator",
1485 /// In the case of a generator created as part of an async construct,
1486 /// which kind of async construct caused it to be created?
1488 /// This helps error messages but is also used to drive coercions in
1489 /// type-checking (see #60424).
1490 #[derive(Clone, PartialEq, PartialOrd, Eq, Hash, Debug, Copy)]
1491 #[derive(HashStable_Generic, Encodable, Decodable)]
1492 pub enum AsyncGeneratorKind {
1493 /// An explicit `async` block written by the user.
1496 /// An explicit `async` closure written by the user.
1499 /// The `async` block generated as the body of an async function.
1503 impl fmt::Display for AsyncGeneratorKind {
1504 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1505 f.write_str(match self {
1506 AsyncGeneratorKind::Block => "`async` block",
1507 AsyncGeneratorKind::Closure => "`async` closure body",
1508 AsyncGeneratorKind::Fn => "`async fn` body",
1513 impl AsyncGeneratorKind {
1514 pub fn descr(&self) -> &'static str {
1516 AsyncGeneratorKind::Block => "`async` block",
1517 AsyncGeneratorKind::Closure => "`async` closure body",
1518 AsyncGeneratorKind::Fn => "`async fn` body",
1523 #[derive(Copy, Clone, Debug)]
1524 pub enum BodyOwnerKind {
1525 /// Functions and methods.
1531 /// Constants and associated constants.
1534 /// Initializer of a `static` item.
1538 impl BodyOwnerKind {
1539 pub fn is_fn_or_closure(self) -> bool {
1541 BodyOwnerKind::Fn | BodyOwnerKind::Closure => true,
1542 BodyOwnerKind::Const | BodyOwnerKind::Static(_) => false,
1547 /// The kind of an item that requires const-checking.
1548 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
1549 pub enum ConstContext {
1553 /// A `static` or `static mut`.
1556 /// A `const`, associated `const`, or other const context.
1558 /// Other contexts include:
1559 /// - Array length expressions
1560 /// - Enum discriminants
1561 /// - Const generics
1563 /// For the most part, other contexts are treated just like a regular `const`, so they are
1564 /// lumped into the same category.
1569 /// A description of this const context that can appear between backticks in an error message.
1571 /// E.g. `const` or `static mut`.
1572 pub fn keyword_name(self) -> &'static str {
1574 Self::Const => "const",
1575 Self::Static(Mutability::Not) => "static",
1576 Self::Static(Mutability::Mut) => "static mut",
1577 Self::ConstFn => "const fn",
1582 /// A colloquial, trivially pluralizable description of this const context for use in error
1584 impl fmt::Display for ConstContext {
1585 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
1587 Self::Const => write!(f, "constant"),
1588 Self::Static(_) => write!(f, "static"),
1589 Self::ConstFn => write!(f, "constant function"),
1594 // NOTE: `IntoDiagnosticArg` impl for `ConstContext` lives in `rustc_errors`
1595 // due to a cyclical dependency between hir that crate.
1598 pub type Lit = Spanned<LitKind>;
1600 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Debug, HashStable_Generic)]
1607 pub fn hir_id(&self) -> HirId {
1609 &ArrayLen::Infer(hir_id, _) | &ArrayLen::Body(AnonConst { hir_id, body: _ }) => hir_id,
1614 /// A constant (expression) that's not an item or associated item,
1615 /// but needs its own `DefId` for type-checking, const-eval, etc.
1616 /// These are usually found nested inside types (e.g., array lengths)
1617 /// or expressions (e.g., repeat counts), and also used to define
1618 /// explicit discriminant values for enum variants.
1620 /// You can check if this anon const is a default in a const param
1621 /// `const N: usize = { ... }` with `tcx.hir().opt_const_param_default_param_hir_id(..)`
1622 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Debug, HashStable_Generic)]
1623 pub struct AnonConst {
1630 pub struct Expr<'hir> {
1632 pub kind: ExprKind<'hir>,
1637 pub fn precedence(&self) -> ExprPrecedence {
1639 ExprKind::Box(_) => ExprPrecedence::Box,
1640 ExprKind::ConstBlock(_) => ExprPrecedence::ConstBlock,
1641 ExprKind::Array(_) => ExprPrecedence::Array,
1642 ExprKind::Call(..) => ExprPrecedence::Call,
1643 ExprKind::MethodCall(..) => ExprPrecedence::MethodCall,
1644 ExprKind::Tup(_) => ExprPrecedence::Tup,
1645 ExprKind::Binary(op, ..) => ExprPrecedence::Binary(op.node.into()),
1646 ExprKind::Unary(..) => ExprPrecedence::Unary,
1647 ExprKind::Lit(_) => ExprPrecedence::Lit,
1648 ExprKind::Type(..) | ExprKind::Cast(..) => ExprPrecedence::Cast,
1649 ExprKind::DropTemps(ref expr, ..) => expr.precedence(),
1650 ExprKind::If(..) => ExprPrecedence::If,
1651 ExprKind::Let(..) => ExprPrecedence::Let,
1652 ExprKind::Loop(..) => ExprPrecedence::Loop,
1653 ExprKind::Match(..) => ExprPrecedence::Match,
1654 ExprKind::Closure { .. } => ExprPrecedence::Closure,
1655 ExprKind::Block(..) => ExprPrecedence::Block,
1656 ExprKind::Assign(..) => ExprPrecedence::Assign,
1657 ExprKind::AssignOp(..) => ExprPrecedence::AssignOp,
1658 ExprKind::Field(..) => ExprPrecedence::Field,
1659 ExprKind::Index(..) => ExprPrecedence::Index,
1660 ExprKind::Path(..) => ExprPrecedence::Path,
1661 ExprKind::AddrOf(..) => ExprPrecedence::AddrOf,
1662 ExprKind::Break(..) => ExprPrecedence::Break,
1663 ExprKind::Continue(..) => ExprPrecedence::Continue,
1664 ExprKind::Ret(..) => ExprPrecedence::Ret,
1665 ExprKind::InlineAsm(..) => ExprPrecedence::InlineAsm,
1666 ExprKind::Struct(..) => ExprPrecedence::Struct,
1667 ExprKind::Repeat(..) => ExprPrecedence::Repeat,
1668 ExprKind::Yield(..) => ExprPrecedence::Yield,
1669 ExprKind::Err => ExprPrecedence::Err,
1673 // Whether this looks like a place expr, without checking for deref
1675 // This will return `true` in some potentially surprising cases such as
1676 // `CONSTANT.field`.
1677 pub fn is_syntactic_place_expr(&self) -> bool {
1678 self.is_place_expr(|_| true)
1681 /// Whether this is a place expression.
1683 /// `allow_projections_from` should return `true` if indexing a field or index expression based
1684 /// on the given expression should be considered a place expression.
1685 pub fn is_place_expr(&self, mut allow_projections_from: impl FnMut(&Self) -> bool) -> bool {
1687 ExprKind::Path(QPath::Resolved(_, ref path)) => {
1688 matches!(path.res, Res::Local(..) | Res::Def(DefKind::Static(_), _) | Res::Err)
1691 // Type ascription inherits its place expression kind from its
1693 // https://github.com/rust-lang/rfcs/blob/master/text/0803-type-ascription.md#type-ascription-and-temporaries
1694 ExprKind::Type(ref e, _) => e.is_place_expr(allow_projections_from),
1696 ExprKind::Unary(UnOp::Deref, _) => true,
1698 ExprKind::Field(ref base, _) | ExprKind::Index(ref base, _) => {
1699 allow_projections_from(base) || base.is_place_expr(allow_projections_from)
1702 // Lang item paths cannot currently be local variables or statics.
1703 ExprKind::Path(QPath::LangItem(..)) => false,
1705 // Partially qualified paths in expressions can only legally
1706 // refer to associated items which are always rvalues.
1707 ExprKind::Path(QPath::TypeRelative(..))
1708 | ExprKind::Call(..)
1709 | ExprKind::MethodCall(..)
1710 | ExprKind::Struct(..)
1713 | ExprKind::Match(..)
1714 | ExprKind::Closure { .. }
1715 | ExprKind::Block(..)
1716 | ExprKind::Repeat(..)
1717 | ExprKind::Array(..)
1718 | ExprKind::Break(..)
1719 | ExprKind::Continue(..)
1722 | ExprKind::Loop(..)
1723 | ExprKind::Assign(..)
1724 | ExprKind::InlineAsm(..)
1725 | ExprKind::AssignOp(..)
1727 | ExprKind::ConstBlock(..)
1728 | ExprKind::Unary(..)
1730 | ExprKind::AddrOf(..)
1731 | ExprKind::Binary(..)
1732 | ExprKind::Yield(..)
1733 | ExprKind::Cast(..)
1734 | ExprKind::DropTemps(..)
1735 | ExprKind::Err => false,
1739 /// If `Self.kind` is `ExprKind::DropTemps(expr)`, drill down until we get a non-`DropTemps`
1740 /// `Expr`. This is used in suggestions to ignore this `ExprKind` as it is semantically
1741 /// silent, only signaling the ownership system. By doing this, suggestions that check the
1742 /// `ExprKind` of any given `Expr` for presentation don't have to care about `DropTemps`
1743 /// beyond remembering to call this function before doing analysis on it.
1744 pub fn peel_drop_temps(&self) -> &Self {
1745 let mut expr = self;
1746 while let ExprKind::DropTemps(inner) = &expr.kind {
1752 pub fn peel_blocks(&self) -> &Self {
1753 let mut expr = self;
1754 while let ExprKind::Block(Block { expr: Some(inner), .. }, _) = &expr.kind {
1760 pub fn can_have_side_effects(&self) -> bool {
1761 match self.peel_drop_temps().kind {
1762 ExprKind::Path(_) | ExprKind::Lit(_) => false,
1763 ExprKind::Type(base, _)
1764 | ExprKind::Unary(_, base)
1765 | ExprKind::Field(base, _)
1766 | ExprKind::Index(base, _)
1767 | ExprKind::AddrOf(.., base)
1768 | ExprKind::Cast(base, _) => {
1769 // This isn't exactly true for `Index` and all `Unary`, but we are using this
1770 // method exclusively for diagnostics and there's a *cultural* pressure against
1771 // them being used only for its side-effects.
1772 base.can_have_side_effects()
1774 ExprKind::Struct(_, fields, init) => fields
1776 .map(|field| field.expr)
1777 .chain(init.into_iter())
1778 .all(|e| e.can_have_side_effects()),
1780 ExprKind::Array(args)
1781 | ExprKind::Tup(args)
1785 ExprKind::Path(QPath::Resolved(
1787 Path { res: Res::Def(DefKind::Ctor(_, CtorKind::Fn), _), .. },
1792 ) => args.iter().all(|arg| arg.can_have_side_effects()),
1794 | ExprKind::Match(..)
1795 | ExprKind::MethodCall(..)
1796 | ExprKind::Call(..)
1797 | ExprKind::Closure { .. }
1798 | ExprKind::Block(..)
1799 | ExprKind::Repeat(..)
1800 | ExprKind::Break(..)
1801 | ExprKind::Continue(..)
1804 | ExprKind::Loop(..)
1805 | ExprKind::Assign(..)
1806 | ExprKind::InlineAsm(..)
1807 | ExprKind::AssignOp(..)
1808 | ExprKind::ConstBlock(..)
1810 | ExprKind::Binary(..)
1811 | ExprKind::Yield(..)
1812 | ExprKind::DropTemps(..)
1813 | ExprKind::Err => true,
1817 // To a first-order approximation, is this a pattern
1818 pub fn is_approximately_pattern(&self) -> bool {
1821 | ExprKind::Array(_)
1822 | ExprKind::Call(..)
1826 | ExprKind::Struct(..) => true,
1831 pub fn method_ident(&self) -> Option<Ident> {
1833 ExprKind::MethodCall(receiver_method, ..) => Some(receiver_method.ident),
1834 ExprKind::Unary(_, expr) | ExprKind::AddrOf(.., expr) => expr.method_ident(),
1840 /// Checks if the specified expression is a built-in range literal.
1841 /// (See: `LoweringContext::lower_expr()`).
1842 pub fn is_range_literal(expr: &Expr<'_>) -> bool {
1844 // All built-in range literals but `..=` and `..` desugar to `Struct`s.
1845 ExprKind::Struct(ref qpath, _, _) => matches!(
1850 | LangItem::RangeFrom
1851 | LangItem::RangeFull
1852 | LangItem::RangeToInclusive,
1857 // `..=` desugars into `::std::ops::RangeInclusive::new(...)`.
1858 ExprKind::Call(ref func, _) => {
1859 matches!(func.kind, ExprKind::Path(QPath::LangItem(LangItem::RangeInclusiveNew, ..)))
1866 #[derive(Debug, HashStable_Generic)]
1867 pub enum ExprKind<'hir> {
1868 /// A `box x` expression.
1869 Box(&'hir Expr<'hir>),
1870 /// Allow anonymous constants from an inline `const` block
1871 ConstBlock(AnonConst),
1872 /// An array (e.g., `[a, b, c, d]`).
1873 Array(&'hir [Expr<'hir>]),
1874 /// A function call.
1876 /// The first field resolves to the function itself (usually an `ExprKind::Path`),
1877 /// and the second field is the list of arguments.
1878 /// This also represents calling the constructor of
1879 /// tuple-like ADTs such as tuple structs and enum variants.
1880 Call(&'hir Expr<'hir>, &'hir [Expr<'hir>]),
1881 /// A method call (e.g., `x.foo::<'static, Bar, Baz>(a, b, c, d)`).
1883 /// The `PathSegment` represents the method name and its generic arguments
1884 /// (within the angle brackets).
1885 /// The first element of the `&[Expr]` is the expression that evaluates
1886 /// to the object on which the method is being called on (the receiver),
1887 /// and the remaining elements are the rest of the arguments.
1888 /// Thus, `x.foo::<Bar, Baz>(a, b, c, d)` is represented as
1889 /// `ExprKind::MethodCall(PathSegment { foo, [Bar, Baz] }, [x, a, b, c, d], span)`.
1890 /// The final `Span` represents the span of the function and arguments
1891 /// (e.g. `foo::<Bar, Baz>(a, b, c, d)` in `x.foo::<Bar, Baz>(a, b, c, d)`
1893 /// To resolve the called method to a `DefId`, call [`type_dependent_def_id`] with
1894 /// the `hir_id` of the `MethodCall` node itself.
1896 /// [`type_dependent_def_id`]: ../../rustc_middle/ty/struct.TypeckResults.html#method.type_dependent_def_id
1897 MethodCall(&'hir PathSegment<'hir>, &'hir [Expr<'hir>], Span),
1898 /// A tuple (e.g., `(a, b, c, d)`).
1899 Tup(&'hir [Expr<'hir>]),
1900 /// A binary operation (e.g., `a + b`, `a * b`).
1901 Binary(BinOp, &'hir Expr<'hir>, &'hir Expr<'hir>),
1902 /// A unary operation (e.g., `!x`, `*x`).
1903 Unary(UnOp, &'hir Expr<'hir>),
1904 /// A literal (e.g., `1`, `"foo"`).
1906 /// A cast (e.g., `foo as f64`).
1907 Cast(&'hir Expr<'hir>, &'hir Ty<'hir>),
1908 /// A type reference (e.g., `Foo`).
1909 Type(&'hir Expr<'hir>, &'hir Ty<'hir>),
1910 /// Wraps the expression in a terminating scope.
1911 /// This makes it semantically equivalent to `{ let _t = expr; _t }`.
1913 /// This construct only exists to tweak the drop order in HIR lowering.
1914 /// An example of that is the desugaring of `for` loops.
1915 DropTemps(&'hir Expr<'hir>),
1916 /// A `let $pat = $expr` expression.
1918 /// These are not `Local` and only occur as expressions.
1919 /// The `let Some(x) = foo()` in `if let Some(x) = foo()` is an example of `Let(..)`.
1920 Let(&'hir Let<'hir>),
1921 /// An `if` block, with an optional else block.
1923 /// I.e., `if <expr> { <expr> } else { <expr> }`.
1924 If(&'hir Expr<'hir>, &'hir Expr<'hir>, Option<&'hir Expr<'hir>>),
1925 /// A conditionless loop (can be exited with `break`, `continue`, or `return`).
1927 /// I.e., `'label: loop { <block> }`.
1929 /// The `Span` is the loop header (`for x in y`/`while let pat = expr`).
1930 Loop(&'hir Block<'hir>, Option<Label>, LoopSource, Span),
1931 /// A `match` block, with a source that indicates whether or not it is
1932 /// the result of a desugaring, and if so, which kind.
1933 Match(&'hir Expr<'hir>, &'hir [Arm<'hir>], MatchSource),
1934 /// A closure (e.g., `move |a, b, c| {a + b + c}`).
1936 /// The `Span` is the argument block `|...|`.
1938 /// This may also be a generator literal or an `async block` as indicated by the
1939 /// `Option<Movability>`.
1940 Closure(&'hir Closure<'hir>),
1941 /// A block (e.g., `'label: { ... }`).
1942 Block(&'hir Block<'hir>, Option<Label>),
1944 /// An assignment (e.g., `a = foo()`).
1945 Assign(&'hir Expr<'hir>, &'hir Expr<'hir>, Span),
1946 /// An assignment with an operator.
1949 AssignOp(BinOp, &'hir Expr<'hir>, &'hir Expr<'hir>),
1950 /// Access of a named (e.g., `obj.foo`) or unnamed (e.g., `obj.0`) struct or tuple field.
1951 Field(&'hir Expr<'hir>, Ident),
1952 /// An indexing operation (`foo[2]`).
1953 Index(&'hir Expr<'hir>, &'hir Expr<'hir>),
1955 /// Path to a definition, possibly containing lifetime or type parameters.
1958 /// A referencing operation (i.e., `&a` or `&mut a`).
1959 AddrOf(BorrowKind, Mutability, &'hir Expr<'hir>),
1960 /// A `break`, with an optional label to break.
1961 Break(Destination, Option<&'hir Expr<'hir>>),
1962 /// A `continue`, with an optional label.
1963 Continue(Destination),
1964 /// A `return`, with an optional value to be returned.
1965 Ret(Option<&'hir Expr<'hir>>),
1967 /// Inline assembly (from `asm!`), with its outputs and inputs.
1968 InlineAsm(&'hir InlineAsm<'hir>),
1970 /// A struct or struct-like variant literal expression.
1972 /// E.g., `Foo {x: 1, y: 2}`, or `Foo {x: 1, .. base}`,
1973 /// where `base` is the `Option<Expr>`.
1974 Struct(&'hir QPath<'hir>, &'hir [ExprField<'hir>], Option<&'hir Expr<'hir>>),
1976 /// An array literal constructed from one repeated element.
1978 /// E.g., `[1; 5]`. The first expression is the element
1979 /// to be repeated; the second is the number of times to repeat it.
1980 Repeat(&'hir Expr<'hir>, ArrayLen),
1982 /// A suspension point for generators (i.e., `yield <expr>`).
1983 Yield(&'hir Expr<'hir>, YieldSource),
1985 /// A placeholder for an expression that wasn't syntactically well formed in some way.
1989 /// Represents an optionally `Self`-qualified value/type path or associated extension.
1991 /// To resolve the path to a `DefId`, call [`qpath_res`].
1993 /// [`qpath_res`]: ../../rustc_middle/ty/struct.TypeckResults.html#method.qpath_res
1994 #[derive(Debug, HashStable_Generic)]
1995 pub enum QPath<'hir> {
1996 /// Path to a definition, optionally "fully-qualified" with a `Self`
1997 /// type, if the path points to an associated item in a trait.
1999 /// E.g., an unqualified path like `Clone::clone` has `None` for `Self`,
2000 /// while `<Vec<T> as Clone>::clone` has `Some(Vec<T>)` for `Self`,
2001 /// even though they both have the same two-segment `Clone::clone` `Path`.
2002 Resolved(Option<&'hir Ty<'hir>>, &'hir Path<'hir>),
2004 /// Type-related paths (e.g., `<T>::default` or `<T>::Output`).
2005 /// Will be resolved by type-checking to an associated item.
2007 /// UFCS source paths can desugar into this, with `Vec::new` turning into
2008 /// `<Vec>::new`, and `T::X::Y::method` into `<<<T>::X>::Y>::method`,
2009 /// the `X` and `Y` nodes each being a `TyKind::Path(QPath::TypeRelative(..))`.
2010 TypeRelative(&'hir Ty<'hir>, &'hir PathSegment<'hir>),
2012 /// Reference to a `#[lang = "foo"]` item. `HirId` of the inner expr.
2013 LangItem(LangItem, Span, Option<HirId>),
2016 impl<'hir> QPath<'hir> {
2017 /// Returns the span of this `QPath`.
2018 pub fn span(&self) -> Span {
2020 QPath::Resolved(_, path) => path.span,
2021 QPath::TypeRelative(qself, ps) => qself.span.to(ps.ident.span),
2022 QPath::LangItem(_, span, _) => span,
2026 /// Returns the span of the qself of this `QPath`. For example, `()` in
2027 /// `<() as Trait>::method`.
2028 pub fn qself_span(&self) -> Span {
2030 QPath::Resolved(_, path) => path.span,
2031 QPath::TypeRelative(qself, _) => qself.span,
2032 QPath::LangItem(_, span, _) => span,
2036 /// Returns the span of the last segment of this `QPath`. For example, `method` in
2037 /// `<() as Trait>::method`.
2038 pub fn last_segment_span(&self) -> Span {
2040 QPath::Resolved(_, path) => path.segments.last().unwrap().ident.span,
2041 QPath::TypeRelative(_, segment) => segment.ident.span,
2042 QPath::LangItem(_, span, _) => span,
2047 /// Hints at the original code for a let statement.
2048 #[derive(Copy, Clone, Encodable, Debug, HashStable_Generic)]
2049 pub enum LocalSource {
2050 /// A `match _ { .. }`.
2052 /// When lowering async functions, we create locals within the `async move` so that
2053 /// all parameters are dropped after the future is polled.
2055 /// ```ignore (pseudo-Rust)
2056 /// async fn foo(<pattern> @ x: Type) {
2058 /// let <pattern> = x;
2063 /// A desugared `<expr>.await`.
2065 /// A desugared `expr = expr`, where the LHS is a tuple, struct or array.
2066 /// The span is that of the `=` sign.
2067 AssignDesugar(Span),
2070 /// Hints at the original code for a `match _ { .. }`.
2071 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Hash, Debug)]
2072 #[derive(HashStable_Generic)]
2073 pub enum MatchSource {
2074 /// A `match _ { .. }`.
2076 /// A desugared `for _ in _ { .. }` loop.
2078 /// A desugared `?` operator.
2080 /// A desugared `<expr>.await`.
2086 pub const fn name(self) -> &'static str {
2090 ForLoopDesugar => "for",
2092 AwaitDesugar => ".await",
2097 /// The loop type that yielded an `ExprKind::Loop`.
2098 #[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]
2099 pub enum LoopSource {
2100 /// A `loop { .. }` loop.
2102 /// A `while _ { .. }` loop.
2104 /// A `for _ in _ { .. }` loop.
2109 pub fn name(self) -> &'static str {
2111 LoopSource::Loop => "loop",
2112 LoopSource::While => "while",
2113 LoopSource::ForLoop => "for",
2118 #[derive(Copy, Clone, Encodable, Debug, HashStable_Generic)]
2119 pub enum LoopIdError {
2121 UnlabeledCfInWhileCondition,
2125 impl fmt::Display for LoopIdError {
2126 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2127 f.write_str(match self {
2128 LoopIdError::OutsideLoopScope => "not inside loop scope",
2129 LoopIdError::UnlabeledCfInWhileCondition => {
2130 "unlabeled control flow (break or continue) in while condition"
2132 LoopIdError::UnresolvedLabel => "label not found",
2137 #[derive(Copy, Clone, Encodable, Debug, HashStable_Generic)]
2138 pub struct Destination {
2139 // This is `Some(_)` iff there is an explicit user-specified `label
2140 pub label: Option<Label>,
2142 // These errors are caught and then reported during the diagnostics pass in
2143 // librustc_passes/loops.rs
2144 pub target_id: Result<HirId, LoopIdError>,
2147 /// The yield kind that caused an `ExprKind::Yield`.
2148 #[derive(Copy, Clone, PartialEq, Eq, Debug, Encodable, Decodable, HashStable_Generic)]
2149 pub enum YieldSource {
2150 /// An `<expr>.await`.
2151 Await { expr: Option<HirId> },
2152 /// A plain `yield`.
2157 pub fn is_await(&self) -> bool {
2158 matches!(self, YieldSource::Await { .. })
2162 impl fmt::Display for YieldSource {
2163 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2164 f.write_str(match self {
2165 YieldSource::Await { .. } => "`await`",
2166 YieldSource::Yield => "`yield`",
2171 impl From<GeneratorKind> for YieldSource {
2172 fn from(kind: GeneratorKind) -> Self {
2174 // Guess based on the kind of the current generator.
2175 GeneratorKind::Gen => Self::Yield,
2176 GeneratorKind::Async(_) => Self::Await { expr: None },
2181 // N.B., if you change this, you'll probably want to change the corresponding
2182 // type structure in middle/ty.rs as well.
2183 #[derive(Debug, HashStable_Generic)]
2184 pub struct MutTy<'hir> {
2185 pub ty: &'hir Ty<'hir>,
2186 pub mutbl: Mutability,
2189 /// Represents a function's signature in a trait declaration,
2190 /// trait implementation, or a free function.
2191 #[derive(Debug, HashStable_Generic)]
2192 pub struct FnSig<'hir> {
2193 pub header: FnHeader,
2194 pub decl: &'hir FnDecl<'hir>,
2198 // The bodies for items are stored "out of line", in a separate
2199 // hashmap in the `Crate`. Here we just record the hir-id of the item
2200 // so it can fetched later.
2201 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
2202 pub struct TraitItemId {
2203 pub def_id: LocalDefId,
2208 pub fn hir_id(&self) -> HirId {
2209 // Items are always HIR owners.
2210 HirId::make_owner(self.def_id)
2214 /// Represents an item declaration within a trait declaration,
2215 /// possibly including a default implementation. A trait item is
2216 /// either required (meaning it doesn't have an implementation, just a
2217 /// signature) or provided (meaning it has a default implementation).
2218 #[derive(Debug, HashStable_Generic)]
2219 pub struct TraitItem<'hir> {
2221 pub def_id: LocalDefId,
2222 pub generics: &'hir Generics<'hir>,
2223 pub kind: TraitItemKind<'hir>,
2225 pub defaultness: Defaultness,
2228 impl TraitItem<'_> {
2230 pub fn hir_id(&self) -> HirId {
2231 // Items are always HIR owners.
2232 HirId::make_owner(self.def_id)
2235 pub fn trait_item_id(&self) -> TraitItemId {
2236 TraitItemId { def_id: self.def_id }
2240 /// Represents a trait method's body (or just argument names).
2241 #[derive(Encodable, Debug, HashStable_Generic)]
2242 pub enum TraitFn<'hir> {
2243 /// No default body in the trait, just a signature.
2244 Required(&'hir [Ident]),
2246 /// Both signature and body are provided in the trait.
2250 /// Represents a trait method or associated constant or type
2251 #[derive(Debug, HashStable_Generic)]
2252 pub enum TraitItemKind<'hir> {
2253 /// An associated constant with an optional value (otherwise `impl`s must contain a value).
2254 Const(&'hir Ty<'hir>, Option<BodyId>),
2255 /// An associated function with an optional body.
2256 Fn(FnSig<'hir>, TraitFn<'hir>),
2257 /// An associated type with (possibly empty) bounds and optional concrete
2259 Type(GenericBounds<'hir>, Option<&'hir Ty<'hir>>),
2262 // The bodies for items are stored "out of line", in a separate
2263 // hashmap in the `Crate`. Here we just record the hir-id of the item
2264 // so it can fetched later.
2265 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
2266 pub struct ImplItemId {
2267 pub def_id: LocalDefId,
2272 pub fn hir_id(&self) -> HirId {
2273 // Items are always HIR owners.
2274 HirId::make_owner(self.def_id)
2278 /// Represents anything within an `impl` block.
2279 #[derive(Debug, HashStable_Generic)]
2280 pub struct ImplItem<'hir> {
2282 pub def_id: LocalDefId,
2283 pub generics: &'hir Generics<'hir>,
2284 pub kind: ImplItemKind<'hir>,
2285 pub defaultness: Defaultness,
2292 pub fn hir_id(&self) -> HirId {
2293 // Items are always HIR owners.
2294 HirId::make_owner(self.def_id)
2297 pub fn impl_item_id(&self) -> ImplItemId {
2298 ImplItemId { def_id: self.def_id }
2302 /// Represents various kinds of content within an `impl`.
2303 #[derive(Debug, HashStable_Generic)]
2304 pub enum ImplItemKind<'hir> {
2305 /// An associated constant of the given type, set to the constant result
2306 /// of the expression.
2307 Const(&'hir Ty<'hir>, BodyId),
2308 /// An associated function implementation with the given signature and body.
2309 Fn(FnSig<'hir>, BodyId),
2310 /// An associated type.
2311 TyAlias(&'hir Ty<'hir>),
2314 // The name of the associated type for `Fn` return types.
2315 pub const FN_OUTPUT_NAME: Symbol = sym::Output;
2317 /// Bind a type to an associated type (i.e., `A = Foo`).
2319 /// Bindings like `A: Debug` are represented as a special type `A =
2320 /// $::Debug` that is understood by the astconv code.
2322 /// FIXME(alexreg): why have a separate type for the binding case,
2323 /// wouldn't it be better to make the `ty` field an enum like the
2326 /// ```ignore (pseudo-rust)
2327 /// enum TypeBindingKind {
2332 #[derive(Debug, HashStable_Generic)]
2333 pub struct TypeBinding<'hir> {
2336 pub gen_args: &'hir GenericArgs<'hir>,
2337 pub kind: TypeBindingKind<'hir>,
2341 #[derive(Debug, HashStable_Generic)]
2342 pub enum Term<'hir> {
2347 impl<'hir> From<&'hir Ty<'hir>> for Term<'hir> {
2348 fn from(ty: &'hir Ty<'hir>) -> Self {
2353 impl<'hir> From<AnonConst> for Term<'hir> {
2354 fn from(c: AnonConst) -> Self {
2359 // Represents the two kinds of type bindings.
2360 #[derive(Debug, HashStable_Generic)]
2361 pub enum TypeBindingKind<'hir> {
2362 /// E.g., `Foo<Bar: Send>`.
2363 Constraint { bounds: &'hir [GenericBound<'hir>] },
2364 /// E.g., `Foo<Bar = ()>`, `Foo<Bar = ()>`
2365 Equality { term: Term<'hir> },
2368 impl TypeBinding<'_> {
2369 pub fn ty(&self) -> &Ty<'_> {
2371 TypeBindingKind::Equality { term: Term::Ty(ref ty) } => ty,
2372 _ => panic!("expected equality type binding for parenthesized generic args"),
2375 pub fn opt_const(&self) -> Option<&'_ AnonConst> {
2377 TypeBindingKind::Equality { term: Term::Const(ref c) } => Some(c),
2384 pub struct Ty<'hir> {
2386 pub kind: TyKind<'hir>,
2390 impl<'hir> Ty<'hir> {
2391 /// Returns `true` if `param_def_id` matches the `bounded_ty` of this predicate.
2392 pub fn as_generic_param(&self) -> Option<(DefId, Ident)> {
2393 let TyKind::Path(QPath::Resolved(None, path)) = self.kind else {
2396 let [segment] = &path.segments else {
2400 Res::Def(DefKind::TyParam, def_id)
2401 | Res::SelfTy { trait_: Some(def_id), alias_to: None } => Some((def_id, segment.ident)),
2407 /// Not represented directly in the AST; referred to by name through a `ty_path`.
2408 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Hash, Debug)]
2409 #[derive(HashStable_Generic)]
2420 /// All of the primitive types
2421 pub const ALL: [Self; 17] = [
2422 // any changes here should also be reflected in `PrimTy::from_name`
2423 Self::Int(IntTy::I8),
2424 Self::Int(IntTy::I16),
2425 Self::Int(IntTy::I32),
2426 Self::Int(IntTy::I64),
2427 Self::Int(IntTy::I128),
2428 Self::Int(IntTy::Isize),
2429 Self::Uint(UintTy::U8),
2430 Self::Uint(UintTy::U16),
2431 Self::Uint(UintTy::U32),
2432 Self::Uint(UintTy::U64),
2433 Self::Uint(UintTy::U128),
2434 Self::Uint(UintTy::Usize),
2435 Self::Float(FloatTy::F32),
2436 Self::Float(FloatTy::F64),
2442 /// Like [`PrimTy::name`], but returns a &str instead of a symbol.
2445 pub fn name_str(self) -> &'static str {
2447 PrimTy::Int(i) => i.name_str(),
2448 PrimTy::Uint(u) => u.name_str(),
2449 PrimTy::Float(f) => f.name_str(),
2450 PrimTy::Str => "str",
2451 PrimTy::Bool => "bool",
2452 PrimTy::Char => "char",
2456 pub fn name(self) -> Symbol {
2458 PrimTy::Int(i) => i.name(),
2459 PrimTy::Uint(u) => u.name(),
2460 PrimTy::Float(f) => f.name(),
2461 PrimTy::Str => sym::str,
2462 PrimTy::Bool => sym::bool,
2463 PrimTy::Char => sym::char,
2467 /// Returns the matching `PrimTy` for a `Symbol` such as "str" or "i32".
2468 /// Returns `None` if no matching type is found.
2469 pub fn from_name(name: Symbol) -> Option<Self> {
2470 let ty = match name {
2471 // any changes here should also be reflected in `PrimTy::ALL`
2472 sym::i8 => Self::Int(IntTy::I8),
2473 sym::i16 => Self::Int(IntTy::I16),
2474 sym::i32 => Self::Int(IntTy::I32),
2475 sym::i64 => Self::Int(IntTy::I64),
2476 sym::i128 => Self::Int(IntTy::I128),
2477 sym::isize => Self::Int(IntTy::Isize),
2478 sym::u8 => Self::Uint(UintTy::U8),
2479 sym::u16 => Self::Uint(UintTy::U16),
2480 sym::u32 => Self::Uint(UintTy::U32),
2481 sym::u64 => Self::Uint(UintTy::U64),
2482 sym::u128 => Self::Uint(UintTy::U128),
2483 sym::usize => Self::Uint(UintTy::Usize),
2484 sym::f32 => Self::Float(FloatTy::F32),
2485 sym::f64 => Self::Float(FloatTy::F64),
2486 sym::bool => Self::Bool,
2487 sym::char => Self::Char,
2488 sym::str => Self::Str,
2495 #[derive(Debug, HashStable_Generic)]
2496 pub struct BareFnTy<'hir> {
2497 pub unsafety: Unsafety,
2499 pub generic_params: &'hir [GenericParam<'hir>],
2500 pub decl: &'hir FnDecl<'hir>,
2501 pub param_names: &'hir [Ident],
2504 #[derive(Debug, HashStable_Generic)]
2505 pub struct OpaqueTy<'hir> {
2506 pub generics: &'hir Generics<'hir>,
2507 pub bounds: GenericBounds<'hir>,
2508 pub origin: OpaqueTyOrigin,
2511 /// From whence the opaque type came.
2512 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
2513 pub enum OpaqueTyOrigin {
2515 FnReturn(LocalDefId),
2517 AsyncFn(LocalDefId),
2518 /// type aliases: `type Foo = impl Trait;`
2522 /// The various kinds of types recognized by the compiler.
2523 #[derive(Debug, HashStable_Generic)]
2524 pub enum TyKind<'hir> {
2525 /// A variable length slice (i.e., `[T]`).
2526 Slice(&'hir Ty<'hir>),
2527 /// A fixed length array (i.e., `[T; n]`).
2528 Array(&'hir Ty<'hir>, ArrayLen),
2529 /// A raw pointer (i.e., `*const T` or `*mut T`).
2531 /// A reference (i.e., `&'a T` or `&'a mut T`).
2532 Rptr(Lifetime, MutTy<'hir>),
2533 /// A bare function (e.g., `fn(usize) -> bool`).
2534 BareFn(&'hir BareFnTy<'hir>),
2535 /// The never type (`!`).
2537 /// A tuple (`(A, B, C, D, ...)`).
2538 Tup(&'hir [Ty<'hir>]),
2539 /// A path to a type definition (`module::module::...::Type`), or an
2540 /// associated type (e.g., `<Vec<T> as Trait>::Type` or `<T>::Target`).
2542 /// Type parameters may be stored in each `PathSegment`.
2544 /// An opaque type definition itself. This is only used for `impl Trait`.
2546 /// The generic argument list contains the lifetimes (and in the future
2547 /// possibly parameters) that are actually bound on the `impl Trait`.
2548 OpaqueDef(ItemId, &'hir [GenericArg<'hir>]),
2549 /// A trait object type `Bound1 + Bound2 + Bound3`
2550 /// where `Bound` is a trait or a lifetime.
2551 TraitObject(&'hir [PolyTraitRef<'hir>], Lifetime, TraitObjectSyntax),
2554 /// `TyKind::Infer` means the type should be inferred instead of it having been
2555 /// specified. This can appear anywhere in a type.
2557 /// Placeholder for a type that has failed to be defined.
2561 #[derive(Debug, HashStable_Generic)]
2562 pub enum InlineAsmOperand<'hir> {
2564 reg: InlineAsmRegOrRegClass,
2568 reg: InlineAsmRegOrRegClass,
2570 expr: Option<Expr<'hir>>,
2573 reg: InlineAsmRegOrRegClass,
2578 reg: InlineAsmRegOrRegClass,
2580 in_expr: Expr<'hir>,
2581 out_expr: Option<Expr<'hir>>,
2584 anon_const: AnonConst,
2587 anon_const: AnonConst,
2595 impl<'hir> InlineAsmOperand<'hir> {
2596 pub fn reg(&self) -> Option<InlineAsmRegOrRegClass> {
2598 Self::In { reg, .. }
2599 | Self::Out { reg, .. }
2600 | Self::InOut { reg, .. }
2601 | Self::SplitInOut { reg, .. } => Some(reg),
2602 Self::Const { .. } | Self::SymFn { .. } | Self::SymStatic { .. } => None,
2606 pub fn is_clobber(&self) -> bool {
2609 InlineAsmOperand::Out { reg: InlineAsmRegOrRegClass::Reg(_), late: _, expr: None }
2614 #[derive(Debug, HashStable_Generic)]
2615 pub struct InlineAsm<'hir> {
2616 pub template: &'hir [InlineAsmTemplatePiece],
2617 pub template_strs: &'hir [(Symbol, Option<Symbol>, Span)],
2618 pub operands: &'hir [(InlineAsmOperand<'hir>, Span)],
2619 pub options: InlineAsmOptions,
2620 pub line_spans: &'hir [Span],
2623 /// Represents a parameter in a function header.
2624 #[derive(Debug, HashStable_Generic)]
2625 pub struct Param<'hir> {
2627 pub pat: &'hir Pat<'hir>,
2632 /// Represents the header (not the body) of a function declaration.
2633 #[derive(Debug, HashStable_Generic)]
2634 pub struct FnDecl<'hir> {
2635 /// The types of the function's parameters.
2637 /// Additional argument data is stored in the function's [body](Body::params).
2638 pub inputs: &'hir [Ty<'hir>],
2639 pub output: FnRetTy<'hir>,
2640 pub c_variadic: bool,
2641 /// Does the function have an implicit self?
2642 pub implicit_self: ImplicitSelfKind,
2645 /// Represents what type of implicit self a function has, if any.
2646 #[derive(Copy, Clone, Encodable, Decodable, Debug, HashStable_Generic)]
2647 pub enum ImplicitSelfKind {
2648 /// Represents a `fn x(self);`.
2650 /// Represents a `fn x(mut self);`.
2652 /// Represents a `fn x(&self);`.
2654 /// Represents a `fn x(&mut self);`.
2656 /// Represents when a function does not have a self argument or
2657 /// when a function has a `self: X` argument.
2661 impl ImplicitSelfKind {
2662 /// Does this represent an implicit self?
2663 pub fn has_implicit_self(&self) -> bool {
2664 !matches!(*self, ImplicitSelfKind::None)
2668 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Encodable, Decodable, Debug)]
2669 #[derive(HashStable_Generic)]
2675 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, Encodable, Decodable, HashStable_Generic)]
2676 pub enum Defaultness {
2677 Default { has_value: bool },
2682 pub fn has_value(&self) -> bool {
2684 Defaultness::Default { has_value } => has_value,
2685 Defaultness::Final => true,
2689 pub fn is_final(&self) -> bool {
2690 *self == Defaultness::Final
2693 pub fn is_default(&self) -> bool {
2694 matches!(*self, Defaultness::Default { .. })
2698 #[derive(Debug, HashStable_Generic)]
2699 pub enum FnRetTy<'hir> {
2700 /// Return type is not specified.
2702 /// Functions default to `()` and
2703 /// closures default to inference. Span points to where return
2704 /// type would be inserted.
2705 DefaultReturn(Span),
2706 /// Everything else.
2707 Return(&'hir Ty<'hir>),
2712 pub fn span(&self) -> Span {
2714 Self::DefaultReturn(span) => span,
2715 Self::Return(ref ty) => ty.span,
2720 /// Represents `for<...>` binder before a closure
2721 #[derive(Copy, Clone, Debug, HashStable_Generic)]
2722 pub enum ClosureBinder {
2723 /// Binder is not specified.
2725 /// Binder is specified.
2727 /// Span points to the whole `for<...>`.
2731 #[derive(Encodable, Debug, HashStable_Generic)]
2732 pub struct Mod<'hir> {
2733 pub spans: ModSpans,
2734 pub item_ids: &'hir [ItemId],
2737 #[derive(Copy, Clone, Debug, HashStable_Generic, Encodable)]
2738 pub struct ModSpans {
2739 /// A span from the first token past `{` to the last token until `}`.
2740 /// For `mod foo;`, the inner span ranges from the first token
2741 /// to the last token in the external file.
2742 pub inner_span: Span,
2743 pub inject_use_span: Span,
2746 #[derive(Debug, HashStable_Generic)]
2747 pub struct EnumDef<'hir> {
2748 pub variants: &'hir [Variant<'hir>],
2751 #[derive(Debug, HashStable_Generic)]
2752 pub struct Variant<'hir> {
2753 /// Name of the variant.
2755 /// Id of the variant (not the constructor, see `VariantData::ctor_hir_id()`).
2757 /// Fields and constructor id of the variant.
2758 pub data: VariantData<'hir>,
2759 /// Explicit discriminant (e.g., `Foo = 1`).
2760 pub disr_expr: Option<AnonConst>,
2765 #[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]
2767 /// One import, e.g., `use foo::bar` or `use foo::bar as baz`.
2768 /// Also produced for each element of a list `use`, e.g.
2769 /// `use foo::{a, b}` lowers to `use foo::a; use foo::b;`.
2772 /// Glob import, e.g., `use foo::*`.
2775 /// Degenerate list import, e.g., `use foo::{a, b}` produces
2776 /// an additional `use foo::{}` for performing checks such as
2777 /// unstable feature gating. May be removed in the future.
2781 /// References to traits in impls.
2783 /// `resolve` maps each `TraitRef`'s `ref_id` to its defining trait; that's all
2784 /// that the `ref_id` is for. Note that `ref_id`'s value is not the `HirId` of the
2785 /// trait being referred to but just a unique `HirId` that serves as a key
2786 /// within the resolution map.
2787 #[derive(Clone, Debug, HashStable_Generic)]
2788 pub struct TraitRef<'hir> {
2789 pub path: &'hir Path<'hir>,
2790 // Don't hash the `ref_id`. It is tracked via the thing it is used to access.
2791 #[stable_hasher(ignore)]
2792 pub hir_ref_id: HirId,
2796 /// Gets the `DefId` of the referenced trait. It _must_ actually be a trait or trait alias.
2797 pub fn trait_def_id(&self) -> Option<DefId> {
2798 match self.path.res {
2799 Res::Def(DefKind::Trait | DefKind::TraitAlias, did) => Some(did),
2801 _ => unreachable!(),
2806 #[derive(Clone, Debug, HashStable_Generic)]
2807 pub struct PolyTraitRef<'hir> {
2808 /// The `'a` in `for<'a> Foo<&'a T>`.
2809 pub bound_generic_params: &'hir [GenericParam<'hir>],
2811 /// The `Foo<&'a T>` in `for<'a> Foo<&'a T>`.
2812 pub trait_ref: TraitRef<'hir>,
2817 #[derive(Debug, HashStable_Generic)]
2818 pub struct FieldDef<'hir> {
2823 pub ty: &'hir Ty<'hir>,
2827 // Still necessary in couple of places
2828 pub fn is_positional(&self) -> bool {
2829 let first = self.ident.as_str().as_bytes()[0];
2830 (b'0'..=b'9').contains(&first)
2834 /// Fields and constructor IDs of enum variants and structs.
2835 #[derive(Debug, HashStable_Generic)]
2836 pub enum VariantData<'hir> {
2837 /// A struct variant.
2839 /// E.g., `Bar { .. }` as in `enum Foo { Bar { .. } }`.
2840 Struct(&'hir [FieldDef<'hir>], /* recovered */ bool),
2841 /// A tuple variant.
2843 /// E.g., `Bar(..)` as in `enum Foo { Bar(..) }`.
2844 Tuple(&'hir [FieldDef<'hir>], HirId),
2847 /// E.g., `Bar = ..` as in `enum Foo { Bar = .. }`.
2851 impl<'hir> VariantData<'hir> {
2852 /// Return the fields of this variant.
2853 pub fn fields(&self) -> &'hir [FieldDef<'hir>] {
2855 VariantData::Struct(ref fields, ..) | VariantData::Tuple(ref fields, ..) => fields,
2860 /// Return the `HirId` of this variant's constructor, if it has one.
2861 pub fn ctor_hir_id(&self) -> Option<HirId> {
2863 VariantData::Struct(_, _) => None,
2864 VariantData::Tuple(_, hir_id) | VariantData::Unit(hir_id) => Some(hir_id),
2869 // The bodies for items are stored "out of line", in a separate
2870 // hashmap in the `Crate`. Here we just record the hir-id of the item
2871 // so it can fetched later.
2872 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, Hash, HashStable_Generic)]
2874 pub def_id: LocalDefId,
2879 pub fn hir_id(&self) -> HirId {
2880 // Items are always HIR owners.
2881 HirId::make_owner(self.def_id)
2887 /// The name might be a dummy name in case of anonymous items
2888 #[derive(Debug, HashStable_Generic)]
2889 pub struct Item<'hir> {
2891 pub def_id: LocalDefId,
2892 pub kind: ItemKind<'hir>,
2899 pub fn hir_id(&self) -> HirId {
2900 // Items are always HIR owners.
2901 HirId::make_owner(self.def_id)
2904 pub fn item_id(&self) -> ItemId {
2905 ItemId { def_id: self.def_id }
2909 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
2910 #[derive(Encodable, Decodable, HashStable_Generic)]
2917 pub fn prefix_str(&self) -> &'static str {
2919 Self::Unsafe => "unsafe ",
2925 impl fmt::Display for Unsafety {
2926 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2927 f.write_str(match *self {
2928 Self::Unsafe => "unsafe",
2929 Self::Normal => "normal",
2934 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
2935 #[derive(Encodable, Decodable, HashStable_Generic)]
2936 pub enum Constness {
2941 impl fmt::Display for Constness {
2942 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2943 f.write_str(match *self {
2944 Self::Const => "const",
2945 Self::NotConst => "non-const",
2950 #[derive(Copy, Clone, Encodable, Debug, HashStable_Generic)]
2951 pub struct FnHeader {
2952 pub unsafety: Unsafety,
2953 pub constness: Constness,
2954 pub asyncness: IsAsync,
2959 pub fn is_async(&self) -> bool {
2960 matches!(&self.asyncness, IsAsync::Async)
2963 pub fn is_const(&self) -> bool {
2964 matches!(&self.constness, Constness::Const)
2967 pub fn is_unsafe(&self) -> bool {
2968 matches!(&self.unsafety, Unsafety::Unsafe)
2972 #[derive(Debug, HashStable_Generic)]
2973 pub enum ItemKind<'hir> {
2974 /// An `extern crate` item, with optional *original* crate name if the crate was renamed.
2976 /// E.g., `extern crate foo` or `extern crate foo_bar as foo`.
2977 ExternCrate(Option<Symbol>),
2979 /// `use foo::bar::*;` or `use foo::bar::baz as quux;`
2983 /// `use foo::bar::baz;` (with `as baz` implicitly on the right).
2984 Use(&'hir Path<'hir>, UseKind),
2986 /// A `static` item.
2987 Static(&'hir Ty<'hir>, Mutability, BodyId),
2989 Const(&'hir Ty<'hir>, BodyId),
2990 /// A function declaration.
2991 Fn(FnSig<'hir>, &'hir Generics<'hir>, BodyId),
2992 /// A MBE macro definition (`macro_rules!` or `macro`).
2993 Macro(ast::MacroDef, MacroKind),
2996 /// An external module, e.g. `extern { .. }`.
2997 ForeignMod { abi: Abi, items: &'hir [ForeignItemRef] },
2998 /// Module-level inline assembly (from `global_asm!`).
2999 GlobalAsm(&'hir InlineAsm<'hir>),
3000 /// A type alias, e.g., `type Foo = Bar<u8>`.
3001 TyAlias(&'hir Ty<'hir>, &'hir Generics<'hir>),
3002 /// An opaque `impl Trait` type alias, e.g., `type Foo = impl Bar;`.
3003 OpaqueTy(OpaqueTy<'hir>),
3004 /// An enum definition, e.g., `enum Foo<A, B> {C<A>, D<B>}`.
3005 Enum(EnumDef<'hir>, &'hir Generics<'hir>),
3006 /// A struct definition, e.g., `struct Foo<A> {x: A}`.
3007 Struct(VariantData<'hir>, &'hir Generics<'hir>),
3008 /// A union definition, e.g., `union Foo<A, B> {x: A, y: B}`.
3009 Union(VariantData<'hir>, &'hir Generics<'hir>),
3010 /// A trait definition.
3011 Trait(IsAuto, Unsafety, &'hir Generics<'hir>, GenericBounds<'hir>, &'hir [TraitItemRef]),
3013 TraitAlias(&'hir Generics<'hir>, GenericBounds<'hir>),
3015 /// An implementation, e.g., `impl<A> Trait for Foo { .. }`.
3016 Impl(&'hir Impl<'hir>),
3019 #[derive(Debug, HashStable_Generic)]
3020 pub struct Impl<'hir> {
3021 pub unsafety: Unsafety,
3022 pub polarity: ImplPolarity,
3023 pub defaultness: Defaultness,
3024 // We do not put a `Span` in `Defaultness` because it breaks foreign crate metadata
3025 // decoding as `Span`s cannot be decoded when a `Session` is not available.
3026 pub defaultness_span: Option<Span>,
3027 pub constness: Constness,
3028 pub generics: &'hir Generics<'hir>,
3030 /// The trait being implemented, if any.
3031 pub of_trait: Option<TraitRef<'hir>>,
3033 pub self_ty: &'hir Ty<'hir>,
3034 pub items: &'hir [ImplItemRef],
3038 pub fn generics(&self) -> Option<&Generics<'_>> {
3040 ItemKind::Fn(_, ref generics, _)
3041 | ItemKind::TyAlias(_, ref generics)
3042 | ItemKind::OpaqueTy(OpaqueTy { ref generics, .. })
3043 | ItemKind::Enum(_, ref generics)
3044 | ItemKind::Struct(_, ref generics)
3045 | ItemKind::Union(_, ref generics)
3046 | ItemKind::Trait(_, _, ref generics, _, _)
3047 | ItemKind::TraitAlias(ref generics, _)
3048 | ItemKind::Impl(Impl { ref generics, .. }) => generics,
3053 pub fn descr(&self) -> &'static str {
3055 ItemKind::ExternCrate(..) => "extern crate",
3056 ItemKind::Use(..) => "`use` import",
3057 ItemKind::Static(..) => "static item",
3058 ItemKind::Const(..) => "constant item",
3059 ItemKind::Fn(..) => "function",
3060 ItemKind::Macro(..) => "macro",
3061 ItemKind::Mod(..) => "module",
3062 ItemKind::ForeignMod { .. } => "extern block",
3063 ItemKind::GlobalAsm(..) => "global asm item",
3064 ItemKind::TyAlias(..) => "type alias",
3065 ItemKind::OpaqueTy(..) => "opaque type",
3066 ItemKind::Enum(..) => "enum",
3067 ItemKind::Struct(..) => "struct",
3068 ItemKind::Union(..) => "union",
3069 ItemKind::Trait(..) => "trait",
3070 ItemKind::TraitAlias(..) => "trait alias",
3071 ItemKind::Impl(..) => "implementation",
3076 /// A reference from an trait to one of its associated items. This
3077 /// contains the item's id, naturally, but also the item's name and
3078 /// some other high-level details (like whether it is an associated
3079 /// type or method, and whether it is public). This allows other
3080 /// passes to find the impl they want without loading the ID (which
3081 /// means fewer edges in the incremental compilation graph).
3082 #[derive(Encodable, Debug, HashStable_Generic)]
3083 pub struct TraitItemRef {
3084 pub id: TraitItemId,
3086 pub kind: AssocItemKind,
3090 /// A reference from an impl to one of its associated items. This
3091 /// contains the item's ID, naturally, but also the item's name and
3092 /// some other high-level details (like whether it is an associated
3093 /// type or method, and whether it is public). This allows other
3094 /// passes to find the impl they want without loading the ID (which
3095 /// means fewer edges in the incremental compilation graph).
3096 #[derive(Debug, HashStable_Generic)]
3097 pub struct ImplItemRef {
3100 pub kind: AssocItemKind,
3102 /// When we are in a trait impl, link to the trait-item's id.
3103 pub trait_item_def_id: Option<DefId>,
3106 #[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]
3107 pub enum AssocItemKind {
3109 Fn { has_self: bool },
3113 // The bodies for items are stored "out of line", in a separate
3114 // hashmap in the `Crate`. Here we just record the hir-id of the item
3115 // so it can fetched later.
3116 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
3117 pub struct ForeignItemId {
3118 pub def_id: LocalDefId,
3121 impl ForeignItemId {
3123 pub fn hir_id(&self) -> HirId {
3124 // Items are always HIR owners.
3125 HirId::make_owner(self.def_id)
3129 /// A reference from a foreign block to one of its items. This
3130 /// contains the item's ID, naturally, but also the item's name and
3131 /// some other high-level details (like whether it is an associated
3132 /// type or method, and whether it is public). This allows other
3133 /// passes to find the impl they want without loading the ID (which
3134 /// means fewer edges in the incremental compilation graph).
3135 #[derive(Debug, HashStable_Generic)]
3136 pub struct ForeignItemRef {
3137 pub id: ForeignItemId,
3142 #[derive(Debug, HashStable_Generic)]
3143 pub struct ForeignItem<'hir> {
3145 pub kind: ForeignItemKind<'hir>,
3146 pub def_id: LocalDefId,
3151 impl ForeignItem<'_> {
3153 pub fn hir_id(&self) -> HirId {
3154 // Items are always HIR owners.
3155 HirId::make_owner(self.def_id)
3158 pub fn foreign_item_id(&self) -> ForeignItemId {
3159 ForeignItemId { def_id: self.def_id }
3163 /// An item within an `extern` block.
3164 #[derive(Debug, HashStable_Generic)]
3165 pub enum ForeignItemKind<'hir> {
3166 /// A foreign function.
3167 Fn(&'hir FnDecl<'hir>, &'hir [Ident], &'hir Generics<'hir>),
3168 /// A foreign static item (`static ext: u8`).
3169 Static(&'hir Ty<'hir>, Mutability),
3174 /// A variable captured by a closure.
3175 #[derive(Debug, Copy, Clone, Encodable, HashStable_Generic)]
3177 // First span where it is accessed (there can be multiple).
3181 // The TraitCandidate's import_ids is empty if the trait is defined in the same module, and
3182 // has length > 0 if the trait is found through an chain of imports, starting with the
3183 // import/use statement in the scope where the trait is used.
3184 #[derive(Encodable, Decodable, Clone, Debug, HashStable_Generic)]
3185 pub struct TraitCandidate {
3187 pub import_ids: SmallVec<[LocalDefId; 1]>,
3190 #[derive(Copy, Clone, Debug, HashStable_Generic)]
3191 pub enum OwnerNode<'hir> {
3192 Item(&'hir Item<'hir>),
3193 ForeignItem(&'hir ForeignItem<'hir>),
3194 TraitItem(&'hir TraitItem<'hir>),
3195 ImplItem(&'hir ImplItem<'hir>),
3196 Crate(&'hir Mod<'hir>),
3199 impl<'hir> OwnerNode<'hir> {
3200 pub fn ident(&self) -> Option<Ident> {
3202 OwnerNode::Item(Item { ident, .. })
3203 | OwnerNode::ForeignItem(ForeignItem { ident, .. })
3204 | OwnerNode::ImplItem(ImplItem { ident, .. })
3205 | OwnerNode::TraitItem(TraitItem { ident, .. }) => Some(*ident),
3206 OwnerNode::Crate(..) => None,
3210 pub fn span(&self) -> Span {
3212 OwnerNode::Item(Item { span, .. })
3213 | OwnerNode::ForeignItem(ForeignItem { span, .. })
3214 | OwnerNode::ImplItem(ImplItem { span, .. })
3215 | OwnerNode::TraitItem(TraitItem { span, .. }) => *span,
3216 OwnerNode::Crate(Mod { spans: ModSpans { inner_span, .. }, .. }) => *inner_span,
3220 pub fn fn_decl(&self) -> Option<&FnDecl<'hir>> {
3222 OwnerNode::TraitItem(TraitItem { kind: TraitItemKind::Fn(fn_sig, _), .. })
3223 | OwnerNode::ImplItem(ImplItem { kind: ImplItemKind::Fn(fn_sig, _), .. })
3224 | OwnerNode::Item(Item { kind: ItemKind::Fn(fn_sig, _, _), .. }) => Some(fn_sig.decl),
3225 OwnerNode::ForeignItem(ForeignItem {
3226 kind: ForeignItemKind::Fn(fn_decl, _, _),
3228 }) => Some(fn_decl),
3233 pub fn body_id(&self) -> Option<BodyId> {
3235 OwnerNode::TraitItem(TraitItem {
3236 kind: TraitItemKind::Fn(_, TraitFn::Provided(body_id)),
3239 | OwnerNode::ImplItem(ImplItem { kind: ImplItemKind::Fn(_, body_id), .. })
3240 | OwnerNode::Item(Item { kind: ItemKind::Fn(.., body_id), .. }) => Some(*body_id),
3245 pub fn generics(self) -> Option<&'hir Generics<'hir>> {
3246 Node::generics(self.into())
3249 pub fn def_id(self) -> LocalDefId {
3251 OwnerNode::Item(Item { def_id, .. })
3252 | OwnerNode::TraitItem(TraitItem { def_id, .. })
3253 | OwnerNode::ImplItem(ImplItem { def_id, .. })
3254 | OwnerNode::ForeignItem(ForeignItem { def_id, .. }) => *def_id,
3255 OwnerNode::Crate(..) => crate::CRATE_HIR_ID.owner,
3259 pub fn expect_item(self) -> &'hir Item<'hir> {
3261 OwnerNode::Item(n) => n,
3266 pub fn expect_foreign_item(self) -> &'hir ForeignItem<'hir> {
3268 OwnerNode::ForeignItem(n) => n,
3273 pub fn expect_impl_item(self) -> &'hir ImplItem<'hir> {
3275 OwnerNode::ImplItem(n) => n,
3280 pub fn expect_trait_item(self) -> &'hir TraitItem<'hir> {
3282 OwnerNode::TraitItem(n) => n,
3288 impl<'hir> Into<OwnerNode<'hir>> for &'hir Item<'hir> {
3289 fn into(self) -> OwnerNode<'hir> {
3290 OwnerNode::Item(self)
3294 impl<'hir> Into<OwnerNode<'hir>> for &'hir ForeignItem<'hir> {
3295 fn into(self) -> OwnerNode<'hir> {
3296 OwnerNode::ForeignItem(self)
3300 impl<'hir> Into<OwnerNode<'hir>> for &'hir ImplItem<'hir> {
3301 fn into(self) -> OwnerNode<'hir> {
3302 OwnerNode::ImplItem(self)
3306 impl<'hir> Into<OwnerNode<'hir>> for &'hir TraitItem<'hir> {
3307 fn into(self) -> OwnerNode<'hir> {
3308 OwnerNode::TraitItem(self)
3312 impl<'hir> Into<Node<'hir>> for OwnerNode<'hir> {
3313 fn into(self) -> Node<'hir> {
3315 OwnerNode::Item(n) => Node::Item(n),
3316 OwnerNode::ForeignItem(n) => Node::ForeignItem(n),
3317 OwnerNode::ImplItem(n) => Node::ImplItem(n),
3318 OwnerNode::TraitItem(n) => Node::TraitItem(n),
3319 OwnerNode::Crate(n) => Node::Crate(n),
3324 #[derive(Copy, Clone, Debug, HashStable_Generic)]
3325 pub enum Node<'hir> {
3326 Param(&'hir Param<'hir>),
3327 Item(&'hir Item<'hir>),
3328 ForeignItem(&'hir ForeignItem<'hir>),
3329 TraitItem(&'hir TraitItem<'hir>),
3330 ImplItem(&'hir ImplItem<'hir>),
3331 Variant(&'hir Variant<'hir>),
3332 Field(&'hir FieldDef<'hir>),
3333 AnonConst(&'hir AnonConst),
3334 Expr(&'hir Expr<'hir>),
3335 Stmt(&'hir Stmt<'hir>),
3336 PathSegment(&'hir PathSegment<'hir>),
3338 TypeBinding(&'hir TypeBinding<'hir>),
3339 TraitRef(&'hir TraitRef<'hir>),
3340 Pat(&'hir Pat<'hir>),
3341 Arm(&'hir Arm<'hir>),
3342 Block(&'hir Block<'hir>),
3343 Local(&'hir Local<'hir>),
3345 /// `Ctor` refers to the constructor of an enum variant or struct. Only tuple or unit variants
3346 /// with synthesized constructors.
3347 Ctor(&'hir VariantData<'hir>),
3349 Lifetime(&'hir Lifetime),
3350 GenericParam(&'hir GenericParam<'hir>),
3352 Crate(&'hir Mod<'hir>),
3354 Infer(&'hir InferArg),
3357 impl<'hir> Node<'hir> {
3358 /// Get the identifier of this `Node`, if applicable.
3362 /// Calling `.ident()` on a [`Node::Ctor`] will return `None`
3363 /// because `Ctor`s do not have identifiers themselves.
3364 /// Instead, call `.ident()` on the parent struct/variant, like so:
3366 /// ```ignore (illustrative)
3369 /// .and_then(|ctor_id| tcx.hir().find(tcx.hir().get_parent_node(ctor_id)))
3370 /// .and_then(|parent| parent.ident())
3372 pub fn ident(&self) -> Option<Ident> {
3374 Node::TraitItem(TraitItem { ident, .. })
3375 | Node::ImplItem(ImplItem { ident, .. })
3376 | Node::ForeignItem(ForeignItem { ident, .. })
3377 | Node::Field(FieldDef { ident, .. })
3378 | Node::Variant(Variant { ident, .. })
3379 | Node::Item(Item { ident, .. })
3380 | Node::PathSegment(PathSegment { ident, .. }) => Some(*ident),
3381 Node::Lifetime(lt) => Some(lt.name.ident()),
3382 Node::GenericParam(p) => Some(p.name.ident()),
3383 Node::TypeBinding(b) => Some(b.ident),
3385 | Node::AnonConst(..)
3395 | Node::TraitRef(..)
3396 | Node::Infer(..) => None,
3400 pub fn fn_decl(&self) -> Option<&'hir FnDecl<'hir>> {
3402 Node::TraitItem(TraitItem { kind: TraitItemKind::Fn(fn_sig, _), .. })
3403 | Node::ImplItem(ImplItem { kind: ImplItemKind::Fn(fn_sig, _), .. })
3404 | Node::Item(Item { kind: ItemKind::Fn(fn_sig, _, _), .. }) => Some(fn_sig.decl),
3405 Node::ForeignItem(ForeignItem { kind: ForeignItemKind::Fn(fn_decl, _, _), .. }) => {
3412 pub fn fn_sig(&self) -> Option<&'hir FnSig<'hir>> {
3414 Node::TraitItem(TraitItem { kind: TraitItemKind::Fn(fn_sig, _), .. })
3415 | Node::ImplItem(ImplItem { kind: ImplItemKind::Fn(fn_sig, _), .. })
3416 | Node::Item(Item { kind: ItemKind::Fn(fn_sig, _, _), .. }) => Some(fn_sig),
3421 pub fn body_id(&self) -> Option<BodyId> {
3423 Node::TraitItem(TraitItem {
3424 kind: TraitItemKind::Fn(_, TraitFn::Provided(body_id)),
3427 | Node::ImplItem(ImplItem { kind: ImplItemKind::Fn(_, body_id), .. })
3428 | Node::Item(Item { kind: ItemKind::Fn(.., body_id), .. }) => Some(*body_id),
3433 pub fn generics(self) -> Option<&'hir Generics<'hir>> {
3435 Node::ForeignItem(ForeignItem {
3436 kind: ForeignItemKind::Fn(_, _, generics), ..
3438 | Node::TraitItem(TraitItem { generics, .. })
3439 | Node::ImplItem(ImplItem { generics, .. }) => Some(generics),
3440 Node::Item(item) => item.kind.generics(),
3445 pub fn as_owner(self) -> Option<OwnerNode<'hir>> {
3447 Node::Item(i) => Some(OwnerNode::Item(i)),
3448 Node::ForeignItem(i) => Some(OwnerNode::ForeignItem(i)),
3449 Node::TraitItem(i) => Some(OwnerNode::TraitItem(i)),
3450 Node::ImplItem(i) => Some(OwnerNode::ImplItem(i)),
3451 Node::Crate(i) => Some(OwnerNode::Crate(i)),
3456 pub fn fn_kind(self) -> Option<FnKind<'hir>> {
3458 Node::Item(i) => match i.kind {
3459 ItemKind::Fn(ref sig, ref generics, _) => {
3460 Some(FnKind::ItemFn(i.ident, generics, sig.header))
3464 Node::TraitItem(ti) => match ti.kind {
3465 TraitItemKind::Fn(ref sig, TraitFn::Provided(_)) => {
3466 Some(FnKind::Method(ti.ident, sig))
3470 Node::ImplItem(ii) => match ii.kind {
3471 ImplItemKind::Fn(ref sig, _) => Some(FnKind::Method(ii.ident, sig)),
3474 Node::Expr(e) => match e.kind {
3475 ExprKind::Closure { .. } => Some(FnKind::Closure),
3482 /// Get the fields for the tuple-constructor,
3483 /// if this node is a tuple constructor, otherwise None
3484 pub fn tuple_fields(&self) -> Option<&'hir [FieldDef<'hir>]> {
3485 if let Node::Ctor(&VariantData::Tuple(fields, _)) = self { Some(fields) } else { None }
3489 // Some nodes are used a lot. Make sure they don't unintentionally get bigger.
3490 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
3493 // These are in alphabetical order, which is easy to maintain.
3494 rustc_data_structures::static_assert_size!(Block<'static>, 48);
3495 rustc_data_structures::static_assert_size!(Expr<'static>, 56);
3496 rustc_data_structures::static_assert_size!(ForeignItem<'static>, 72);
3497 rustc_data_structures::static_assert_size!(GenericBound<'_>, 48);
3498 rustc_data_structures::static_assert_size!(Generics<'static>, 56);
3499 rustc_data_structures::static_assert_size!(ImplItem<'static>, 88);
3500 rustc_data_structures::static_assert_size!(Impl<'static>, 80);
3501 rustc_data_structures::static_assert_size!(Item<'static>, 80);
3502 rustc_data_structures::static_assert_size!(Pat<'static>, 88);
3503 rustc_data_structures::static_assert_size!(QPath<'static>, 24);
3504 rustc_data_structures::static_assert_size!(TraitItem<'static>, 96);
3505 rustc_data_structures::static_assert_size!(Ty<'static>, 72);