1 //! The Rust abstract syntax tree module.
3 //! This module contains common structures forming the language AST.
4 //! Two main entities in the module are [`Item`] (which represents an AST element with
5 //! additional metadata), and [`ItemKind`] (which represents a concrete type and contains
6 //! information specific to the type of the item).
8 //! Other module items worth mentioning:
9 //! - [`Ty`] and [`TyKind`]: A parsed Rust type.
10 //! - [`Expr`] and [`ExprKind`]: A parsed Rust expression.
11 //! - [`Pat`] and [`PatKind`]: A parsed Rust pattern. Patterns are often dual to expressions.
12 //! - [`Stmt`] and [`StmtKind`]: An executable action that does not return a value.
13 //! - [`FnDecl`], [`FnHeader`] and [`Param`]: Metadata associated with a function declaration.
14 //! - [`Generics`], [`GenericParam`], [`WhereClause`]: Metadata associated with generic parameters.
15 //! - [`EnumDef`] and [`Variant`]: Enum declaration.
16 //! - [`MetaItemLit`] and [`LitKind`]: Literal expressions.
17 //! - [`MacroDef`], [`MacStmtStyle`], [`MacCall`], [`MacDelimiter`]: Macro definition and invocation.
18 //! - [`Attribute`]: Metadata associated with item.
19 //! - [`UnOp`], [`BinOp`], and [`BinOpKind`]: Unary and binary operators.
21 pub use crate::util
::parser
::ExprPrecedence
;
22 pub use GenericArgs
::*;
23 pub use UnsafeSource
::*;
26 use crate::token
::{self, CommentKind, Delimiter}
;
27 use crate::tokenstream
::{DelimSpan, LazyAttrTokenStream, TokenStream}
;
28 use rustc_data_structures
::stable_hasher
::{HashStable, StableHasher}
;
29 use rustc_data_structures
::stack
::ensure_sufficient_stack
;
30 use rustc_data_structures
::sync
::Lrc
;
31 use rustc_macros
::HashStable_Generic
;
32 use rustc_serialize
::{Decodable, Decoder, Encodable, Encoder}
;
33 use rustc_span
::source_map
::{respan, Spanned}
;
34 use rustc_span
::symbol
::{kw, sym, Ident, Symbol}
;
35 use rustc_span
::{Span, DUMMY_SP}
;
36 use std
::convert
::TryFrom
;
39 use thin_vec
::{thin_vec, ThinVec}
;
41 /// A "Label" is an identifier of some point in sources,
42 /// e.g. in the following code:
50 /// `'outer` is a label.
51 #[derive(Clone, Encodable, Decodable, Copy, HashStable_Generic, Eq, PartialEq)]
56 impl fmt
::Debug
for Label
{
57 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
58 write
!(f
, "label({:?})", self.ident
)
62 /// A "Lifetime" is an annotation of the scope in which variable
63 /// can be used, e.g. `'a` in `&'a i32`.
64 #[derive(Clone, Encodable, Decodable, Copy, PartialEq, Eq)]
70 impl fmt
::Debug
for Lifetime
{
71 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
72 write
!(f
, "lifetime({}: {})", self.id
, self)
76 impl fmt
::Display
for Lifetime
{
77 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
78 write
!(f
, "{}", self.ident
.name
)
82 /// A "Path" is essentially Rust's notion of a name.
84 /// It's represented as a sequence of identifiers,
85 /// along with a bunch of supporting information.
87 /// E.g., `std::cmp::PartialEq`.
88 #[derive(Clone, Encodable, Decodable, Debug)]
91 /// The segments in the path: the things separated by `::`.
92 /// Global paths begin with `kw::PathRoot`.
93 pub segments
: ThinVec
<PathSegment
>,
94 pub tokens
: Option
<LazyAttrTokenStream
>,
97 impl PartialEq
<Symbol
> for Path
{
99 fn eq(&self, symbol
: &Symbol
) -> bool
{
100 self.segments
.len() == 1 && { self.segments[0].ident.name == *symbol }
104 impl<CTX
: rustc_span
::HashStableContext
> HashStable
<CTX
> for Path
{
105 fn hash_stable(&self, hcx
: &mut CTX
, hasher
: &mut StableHasher
) {
106 self.segments
.len().hash_stable(hcx
, hasher
);
107 for segment
in &self.segments
{
108 segment
.ident
.hash_stable(hcx
, hasher
);
114 /// Convert a span and an identifier to the corresponding
115 /// one-segment path.
116 pub fn from_ident(ident
: Ident
) -> Path
{
117 Path { segments: thin_vec![PathSegment::from_ident(ident)], span: ident.span, tokens: None }
120 pub fn is_global(&self) -> bool
{
121 !self.segments
.is_empty() && self.segments
[0].ident
.name
== kw
::PathRoot
125 /// A segment of a path: an identifier, an optional lifetime, and a set of types.
127 /// E.g., `std`, `String` or `Box<T>`.
128 #[derive(Clone, Encodable, Decodable, Debug)]
129 pub struct PathSegment
{
130 /// The identifier portion of this path segment.
135 /// Type/lifetime parameters attached to this path. They come in
136 /// two flavors: `Path<A,B,C>` and `Path(A,B) -> C`.
137 /// `None` means that no parameter list is supplied (`Path`),
138 /// `Some` means that parameter list is supplied (`Path<X, Y>`)
139 /// but it can be empty (`Path<>`).
140 /// `P` is used as a size optimization for the common case with no parameters.
141 pub args
: Option
<P
<GenericArgs
>>,
145 pub fn from_ident(ident
: Ident
) -> Self {
146 PathSegment { ident, id: DUMMY_NODE_ID, args: None }
149 pub fn path_root(span
: Span
) -> Self {
150 PathSegment
::from_ident(Ident
::new(kw
::PathRoot
, span
))
153 pub fn span(&self) -> Span
{
155 Some(args
) => self.ident
.span
.to(args
.span()),
156 None
=> self.ident
.span
,
161 /// The arguments of a path segment.
163 /// E.g., `<A, B>` as in `Foo<A, B>` or `(A, B)` as in `Foo(A, B)`.
164 #[derive(Clone, Encodable, Decodable, Debug)]
165 pub enum GenericArgs
{
166 /// The `<'a, A, B, C>` in `foo::bar::baz::<'a, A, B, C>`.
167 AngleBracketed(AngleBracketedArgs
),
168 /// The `(A, B)` and `C` in `Foo(A, B) -> C`.
169 Parenthesized(ParenthesizedArgs
),
173 pub fn is_angle_bracketed(&self) -> bool
{
174 matches
!(self, AngleBracketed(..))
177 pub fn span(&self) -> Span
{
179 AngleBracketed(data
) => data
.span
,
180 Parenthesized(data
) => data
.span
,
185 /// Concrete argument in the sequence of generic args.
186 #[derive(Clone, Encodable, Decodable, Debug)]
187 pub enum GenericArg
{
188 /// `'a` in `Foo<'a>`
190 /// `Bar` in `Foo<Bar>`
197 pub fn span(&self) -> Span
{
199 GenericArg
::Lifetime(lt
) => lt
.ident
.span
,
200 GenericArg
::Type(ty
) => ty
.span
,
201 GenericArg
::Const(ct
) => ct
.value
.span
,
206 /// A path like `Foo<'a, T>`.
207 #[derive(Clone, Encodable, Decodable, Debug, Default)]
208 pub struct AngleBracketedArgs
{
209 /// The overall span.
211 /// The comma separated parts in the `<...>`.
212 pub args
: Vec
<AngleBracketedArg
>,
215 /// Either an argument for a parameter e.g., `'a`, `Vec<u8>`, `0`,
216 /// or a constraint on an associated item, e.g., `Item = String` or `Item: Bound`.
217 #[derive(Clone, Encodable, Decodable, Debug)]
218 pub enum AngleBracketedArg
{
219 /// Argument for a generic parameter.
221 /// Constraint for an associated item.
222 Constraint(AssocConstraint
),
225 impl AngleBracketedArg
{
226 pub fn span(&self) -> Span
{
228 AngleBracketedArg
::Arg(arg
) => arg
.span(),
229 AngleBracketedArg
::Constraint(constraint
) => constraint
.span
,
234 impl Into
<Option
<P
<GenericArgs
>>> for AngleBracketedArgs
{
235 fn into(self) -> Option
<P
<GenericArgs
>> {
236 Some(P(GenericArgs
::AngleBracketed(self)))
240 impl Into
<Option
<P
<GenericArgs
>>> for ParenthesizedArgs
{
241 fn into(self) -> Option
<P
<GenericArgs
>> {
242 Some(P(GenericArgs
::Parenthesized(self)))
246 /// A path like `Foo(A, B) -> C`.
247 #[derive(Clone, Encodable, Decodable, Debug)]
248 pub struct ParenthesizedArgs
{
256 pub inputs
: Vec
<P
<Ty
>>,
262 pub inputs_span
: Span
,
268 impl ParenthesizedArgs
{
269 pub fn as_angle_bracketed_args(&self) -> AngleBracketedArgs
{
274 .map(|input
| AngleBracketedArg
::Arg(GenericArg
::Type(input
)))
276 AngleBracketedArgs { span: self.inputs_span, args }
280 pub use crate::node_id
::{NodeId, CRATE_NODE_ID, DUMMY_NODE_ID}
;
282 /// A modifier on a bound, e.g., `?Trait` or `~const Trait`.
284 /// Negative bounds should also be handled here.
285 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug)]
286 pub enum TraitBoundModifier
{
298 // This parses but will be rejected during AST validation.
302 /// The AST represents all type param bounds as types.
303 /// `typeck::collect::compute_bounds` matches these against
304 /// the "special" built-in traits (see `middle::lang_items`) and
305 /// detects `Copy`, `Send` and `Sync`.
306 #[derive(Clone, Encodable, Decodable, Debug)]
307 pub enum GenericBound
{
308 Trait(PolyTraitRef
, TraitBoundModifier
),
313 pub fn span(&self) -> Span
{
315 GenericBound
::Trait(t
, ..) => t
.span
,
316 GenericBound
::Outlives(l
) => l
.ident
.span
,
321 pub type GenericBounds
= Vec
<GenericBound
>;
323 /// Specifies the enforced ordering for generic parameters. In the future,
324 /// if we wanted to relax this order, we could override `PartialEq` and
325 /// `PartialOrd`, to allow the kinds to be unordered.
326 #[derive(Hash, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
327 pub enum ParamKindOrd
{
332 impl fmt
::Display
for ParamKindOrd
{
333 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
335 ParamKindOrd
::Lifetime
=> "lifetime".fmt(f
),
336 ParamKindOrd
::TypeOrConst
=> "type and const".fmt(f
),
341 #[derive(Clone, Encodable, Decodable, Debug)]
342 pub enum GenericParamKind
{
343 /// A lifetime definition (e.g., `'a: 'b + 'c + 'd`).
346 default: Option
<P
<Ty
>>,
350 /// Span of the `const` keyword.
352 /// Optional default value for the const generic param
353 default: Option
<AnonConst
>,
357 #[derive(Clone, Encodable, Decodable, Debug)]
358 pub struct GenericParam
{
362 pub bounds
: GenericBounds
,
363 pub is_placeholder
: bool
,
364 pub kind
: GenericParamKind
,
365 pub colon_span
: Option
<Span
>,
369 pub fn span(&self) -> Span
{
371 GenericParamKind
::Lifetime
| GenericParamKind
::Type { default: None }
=> {
374 GenericParamKind
::Type { default: Some(ty) }
=> self.ident
.span
.to(ty
.span
),
375 GenericParamKind
::Const { kw_span, default: Some(default), .. }
=> {
376 kw_span
.to(default.value
.span
)
378 GenericParamKind
::Const { kw_span, default: None, ty }
=> kw_span
.to(ty
.span
),
383 /// Represents lifetime, type and const parameters attached to a declaration of
384 /// a function, enum, trait, etc.
385 #[derive(Clone, Encodable, Decodable, Debug)]
386 pub struct Generics
{
387 pub params
: Vec
<GenericParam
>,
388 pub where_clause
: WhereClause
,
392 impl Default
for Generics
{
393 /// Creates an instance of `Generics`.
394 fn default() -> Generics
{
395 Generics { params: Vec::new(), where_clause: Default::default(), span: DUMMY_SP }
399 /// A where-clause in a definition.
400 #[derive(Clone, Encodable, Decodable, Debug)]
401 pub struct WhereClause
{
402 /// `true` if we ate a `where` token: this can happen
403 /// if we parsed no predicates (e.g. `struct Foo where {}`).
404 /// This allows us to pretty-print accurately.
405 pub has_where_token
: bool
,
406 pub predicates
: Vec
<WherePredicate
>,
410 impl Default
for WhereClause
{
411 fn default() -> WhereClause
{
412 WhereClause { has_where_token: false, predicates: Vec::new(), span: DUMMY_SP }
416 /// A single predicate in a where-clause.
417 #[derive(Clone, Encodable, Decodable, Debug)]
418 pub enum WherePredicate
{
419 /// A type binding (e.g., `for<'c> Foo: Send + Clone + 'c`).
420 BoundPredicate(WhereBoundPredicate
),
421 /// A lifetime predicate (e.g., `'a: 'b + 'c`).
422 RegionPredicate(WhereRegionPredicate
),
423 /// An equality predicate (unsupported).
424 EqPredicate(WhereEqPredicate
),
427 impl WherePredicate
{
428 pub fn span(&self) -> Span
{
430 WherePredicate
::BoundPredicate(p
) => p
.span
,
431 WherePredicate
::RegionPredicate(p
) => p
.span
,
432 WherePredicate
::EqPredicate(p
) => p
.span
,
439 /// E.g., `for<'c> Foo: Send + Clone + 'c`.
440 #[derive(Clone, Encodable, Decodable, Debug)]
441 pub struct WhereBoundPredicate
{
443 /// Any generics from a `for` binding.
444 pub bound_generic_params
: Vec
<GenericParam
>,
445 /// The type being bounded.
446 pub bounded_ty
: P
<Ty
>,
447 /// Trait and lifetime bounds (`Clone + Send + 'static`).
448 pub bounds
: GenericBounds
,
451 /// A lifetime predicate.
453 /// E.g., `'a: 'b + 'c`.
454 #[derive(Clone, Encodable, Decodable, Debug)]
455 pub struct WhereRegionPredicate
{
457 pub lifetime
: Lifetime
,
458 pub bounds
: GenericBounds
,
461 /// An equality predicate (unsupported).
464 #[derive(Clone, Encodable, Decodable, Debug)]
465 pub struct WhereEqPredicate
{
471 #[derive(Clone, Encodable, Decodable, Debug)]
474 pub items
: Vec
<P
<Item
>>,
476 /// Must be equal to `CRATE_NODE_ID` after the crate root is expanded, but may hold
477 /// expansion placeholders or an unassigned value (`DUMMY_NODE_ID`) before that.
479 pub is_placeholder
: bool
,
482 /// A semantic representation of a meta item. A meta item is a slightly
483 /// restricted form of an attribute -- it can only contain expressions in
484 /// certain leaf positions, rather than arbitrary token streams -- that is used
485 /// for most built-in attributes.
487 /// E.g., `#[test]`, `#[derive(..)]`, `#[rustfmt::skip]` or `#[feature = "foo"]`.
488 #[derive(Clone, Encodable, Decodable, Debug, HashStable_Generic)]
489 pub struct MetaItem
{
491 pub kind
: MetaItemKind
,
495 /// The meta item kind, containing the data after the initial path.
496 #[derive(Clone, Encodable, Decodable, Debug, HashStable_Generic)]
497 pub enum MetaItemKind
{
500 /// E.g., `#[test]`, which lacks any arguments after `test`.
505 /// E.g., `#[derive(..)]`, where the field represents the `..`.
506 List(Vec
<NestedMetaItem
>),
508 /// Name value meta item.
510 /// E.g., `#[feature = "foo"]`, where the field represents the `"foo"`.
511 NameValue(MetaItemLit
),
514 /// Values inside meta item lists.
516 /// E.g., each of `Clone`, `Copy` in `#[derive(Clone, Copy)]`.
517 #[derive(Clone, Encodable, Decodable, Debug, HashStable_Generic)]
518 pub enum NestedMetaItem
{
519 /// A full MetaItem, for recursive meta items.
524 /// E.g., `"foo"`, `64`, `true`.
528 /// A block (`{ .. }`).
530 /// E.g., `{ .. }` as in `fn foo() { .. }`.
531 #[derive(Clone, Encodable, Decodable, Debug)]
533 /// The statements in the block.
534 pub stmts
: Vec
<Stmt
>,
536 /// Distinguishes between `unsafe { ... }` and `{ ... }`.
537 pub rules
: BlockCheckMode
,
539 pub tokens
: Option
<LazyAttrTokenStream
>,
540 /// The following *isn't* a parse error, but will cause multiple errors in following stages.
547 pub could_be_bare_literal
: bool
,
552 /// Patterns appear in match statements and some other contexts, such as `let` and `if let`.
553 #[derive(Clone, Encodable, Decodable, Debug)]
558 pub tokens
: Option
<LazyAttrTokenStream
>,
562 /// Attempt reparsing the pattern as a type.
563 /// This is intended for use by diagnostics.
564 pub fn to_ty(&self) -> Option
<P
<Ty
>> {
565 let kind
= match &self.kind
{
566 // In a type expression `_` is an inference variable.
567 PatKind
::Wild
=> TyKind
::Infer
,
568 // An IDENT pattern with no binding mode would be valid as path to a type. E.g. `u32`.
569 PatKind
::Ident(BindingAnnotation
::NONE
, ident
, None
) => {
570 TyKind
::Path(None
, Path
::from_ident(*ident
))
572 PatKind
::Path(qself
, path
) => TyKind
::Path(qself
.clone(), path
.clone()),
573 PatKind
::MacCall(mac
) => TyKind
::MacCall(mac
.clone()),
574 // `&mut? P` can be reinterpreted as `&mut? T` where `T` is `P` reparsed as a type.
575 PatKind
::Ref(pat
, mutbl
) => {
576 pat
.to_ty().map(|ty
| TyKind
::Rptr(None
, MutTy { ty, mutbl: *mutbl }
))?
578 // A slice/array pattern `[P]` can be reparsed as `[T]`, an unsized array,
579 // when `P` can be reparsed as a type `T`.
580 PatKind
::Slice(pats
) if pats
.len() == 1 => pats
[0].to_ty().map(TyKind
::Slice
)?
,
581 // A tuple pattern `(P0, .., Pn)` can be reparsed as `(T0, .., Tn)`
582 // assuming `T0` to `Tn` are all syntactically valid as types.
583 PatKind
::Tuple(pats
) => {
584 let mut tys
= Vec
::with_capacity(pats
.len());
585 // FIXME(#48994) - could just be collected into an Option<Vec>
587 tys
.push(pat
.to_ty()?
);
594 Some(P(Ty { kind, id: self.id, span: self.span, tokens: None }
))
597 /// Walk top-down and call `it` in each place where a pattern occurs
598 /// starting with the root pattern `walk` is called on. If `it` returns
599 /// false then we will descend no further but siblings will be processed.
600 pub fn walk(&self, it
: &mut impl FnMut(&Pat
) -> bool
) {
606 // Walk into the pattern associated with `Ident` (if any).
607 PatKind
::Ident(_
, _
, Some(p
)) => p
.walk(it
),
609 // Walk into each field of struct.
610 PatKind
::Struct(_
, _
, fields
, _
) => fields
.iter().for_each(|field
| field
.pat
.walk(it
)),
612 // Sequence of patterns.
613 PatKind
::TupleStruct(_
, _
, s
)
616 | PatKind
::Or(s
) => s
.iter().for_each(|p
| p
.walk(it
)),
618 // Trivial wrappers over inner patterns.
619 PatKind
::Box(s
) | PatKind
::Ref(s
, _
) | PatKind
::Paren(s
) => s
.walk(it
),
621 // These patterns do not contain subpatterns, skip.
628 | PatKind
::MacCall(_
) => {}
632 /// Is this a `..` pattern?
633 pub fn is_rest(&self) -> bool
{
634 matches
!(self.kind
, PatKind
::Rest
)
638 /// A single field in a struct pattern.
640 /// Patterns like the fields of `Foo { x, ref y, ref mut z }`
641 /// are treated the same as `x: x, y: ref y, z: ref mut z`,
642 /// except when `is_shorthand` is true.
643 #[derive(Clone, Encodable, Decodable, Debug)]
644 pub struct PatField
{
645 /// The identifier for the field.
647 /// The pattern the field is destructured to.
649 pub is_shorthand
: bool
,
653 pub is_placeholder
: bool
,
656 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
657 #[derive(Encodable, Decodable, HashStable_Generic)]
663 impl From
<bool
> for ByRef
{
664 fn from(b
: bool
) -> ByRef
{
672 /// Explicit binding annotations given in the HIR for a binding. Note
673 /// that this is not the final binding *mode* that we infer after type
675 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
676 #[derive(Encodable, Decodable, HashStable_Generic)]
677 pub struct BindingAnnotation(pub ByRef
, pub Mutability
);
679 impl BindingAnnotation
{
680 pub const NONE
: Self = Self(ByRef
::No
, Mutability
::Not
);
681 pub const REF
: Self = Self(ByRef
::Yes
, Mutability
::Not
);
682 pub const MUT
: Self = Self(ByRef
::No
, Mutability
::Mut
);
683 pub const REF_MUT
: Self = Self(ByRef
::Yes
, Mutability
::Mut
);
685 pub fn prefix_str(self) -> &'
static str {
690 Self::REF_MUT
=> "ref mut ",
695 #[derive(Clone, Encodable, Decodable, Debug)]
698 Included(RangeSyntax
),
703 #[derive(Clone, Encodable, Decodable, Debug)]
704 pub enum RangeSyntax
{
711 /// All the different flavors of pattern that Rust recognizes.
712 #[derive(Clone, Encodable, Decodable, Debug)]
714 /// Represents a wildcard pattern (`_`).
717 /// A `PatKind::Ident` may either be a new bound variable (`ref mut binding @ OPT_SUBPATTERN`),
718 /// or a unit struct/variant pattern, or a const pattern (in the last two cases the third
719 /// field must be `None`). Disambiguation cannot be done with parser alone, so it happens
720 /// during name resolution.
721 Ident(BindingAnnotation
, Ident
, Option
<P
<Pat
>>),
723 /// A struct or struct variant pattern (e.g., `Variant {x, y, ..}`).
724 /// The `bool` is `true` in the presence of a `..`.
725 Struct(Option
<P
<QSelf
>>, Path
, Vec
<PatField
>, /* recovered */ bool
),
727 /// A tuple struct/variant pattern (`Variant(x, y, .., z)`).
728 TupleStruct(Option
<P
<QSelf
>>, Path
, Vec
<P
<Pat
>>),
730 /// An or-pattern `A | B | C`.
731 /// Invariant: `pats.len() >= 2`.
734 /// A possibly qualified path pattern.
735 /// Unqualified path patterns `A::B::C` can legally refer to variants, structs, constants
736 /// or associated constants. Qualified path patterns `<A>::B::C`/`<A as Trait>::B::C` can
737 /// only legally refer to associated constants.
738 Path(Option
<P
<QSelf
>>, Path
),
740 /// A tuple pattern (`(a, b)`).
746 /// A reference pattern (e.g., `&mut (a, b)`).
747 Ref(P
<Pat
>, Mutability
),
752 /// A range pattern (e.g., `1...2`, `1..2`, `1..`, `..2`, `1..=2`, `..=2`).
753 Range(Option
<P
<Expr
>>, Option
<P
<Expr
>>, Spanned
<RangeEnd
>),
755 /// A slice pattern `[a, b, c]`.
758 /// A rest pattern `..`.
760 /// Syntactically it is valid anywhere.
762 /// Semantically however, it only has meaning immediately inside:
763 /// - a slice pattern: `[a, .., b]`,
764 /// - a binding pattern immediately inside a slice pattern: `[a, r @ ..]`,
765 /// - a tuple pattern: `(a, .., b)`,
766 /// - a tuple struct/variant pattern: `$path(a, .., b)`.
768 /// In all of these cases, an additional restriction applies,
769 /// only one rest pattern may occur in the pattern sequences.
772 /// Parentheses in patterns used for grouping (i.e., `(PAT)`).
775 /// A macro pattern; pre-expansion.
779 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Copy)]
780 #[derive(HashStable_Generic, Encodable, Decodable)]
781 pub enum Mutability
{
782 // N.B. Order is deliberate, so that Not < Mut
788 pub fn invert(self) -> Self {
790 Mutability
::Mut
=> Mutability
::Not
,
791 Mutability
::Not
=> Mutability
::Mut
,
795 /// Returns `""` (empty string) or `"mut "` depending on the mutability.
796 pub fn prefix_str(self) -> &'
static str {
798 Mutability
::Mut
=> "mut ",
799 Mutability
::Not
=> "",
803 /// Returns `"&"` or `"&mut "` depending on the mutability.
804 pub fn ref_prefix_str(self) -> &'
static str {
806 Mutability
::Not
=> "&",
807 Mutability
::Mut
=> "&mut ",
811 /// Returns `""` (empty string) or `"mutably "` depending on the mutability.
812 pub fn mutably_str(self) -> &'
static str {
814 Mutability
::Not
=> "",
815 Mutability
::Mut
=> "mutably ",
819 /// Return `true` if self is mutable
820 pub fn is_mut(self) -> bool
{
821 matches
!(self, Self::Mut
)
824 /// Return `true` if self is **not** mutable
825 pub fn is_not(self) -> bool
{
826 matches
!(self, Self::Not
)
830 /// The kind of borrow in an `AddrOf` expression,
831 /// e.g., `&place` or `&raw const place`.
832 #[derive(Clone, Copy, PartialEq, Eq, Debug)]
833 #[derive(Encodable, Decodable, HashStable_Generic)]
834 pub enum BorrowKind
{
835 /// A normal borrow, `&$expr` or `&mut $expr`.
836 /// The resulting type is either `&'a T` or `&'a mut T`
837 /// where `T = typeof($expr)` and `'a` is some lifetime.
839 /// A raw borrow, `&raw const $expr` or `&raw mut $expr`.
840 /// The resulting type is either `*const T` or `*mut T`
841 /// where `T = typeof($expr)`.
845 #[derive(Clone, PartialEq, Encodable, Decodable, Debug, Copy)]
847 /// The `+` operator (addition)
849 /// The `-` operator (subtraction)
851 /// The `*` operator (multiplication)
853 /// The `/` operator (division)
855 /// The `%` operator (modulus)
857 /// The `&&` operator (logical and)
859 /// The `||` operator (logical or)
861 /// The `^` operator (bitwise xor)
863 /// The `&` operator (bitwise and)
865 /// The `|` operator (bitwise or)
867 /// The `<<` operator (shift left)
869 /// The `>>` operator (shift right)
871 /// The `==` operator (equality)
873 /// The `<` operator (less than)
875 /// The `<=` operator (less than or equal to)
877 /// The `!=` operator (not equal to)
879 /// The `>=` operator (greater than or equal to)
881 /// The `>` operator (greater than)
886 pub fn to_string(&self) -> &'
static str {
909 pub fn lazy(&self) -> bool
{
910 matches
!(self, BinOpKind
::And
| BinOpKind
::Or
)
913 pub fn is_comparison(&self) -> bool
{
915 // Note for developers: please keep this as is;
916 // we want compilation to fail if another variant is added.
918 Eq
| Lt
| Le
| Ne
| Gt
| Ge
=> true,
919 And
| Or
| Add
| Sub
| Mul
| Div
| Rem
| BitXor
| BitAnd
| BitOr
| Shl
| Shr
=> false,
924 pub type BinOp
= Spanned
<BinOpKind
>;
928 /// Note that `&data` is not an operator, it's an `AddrOf` expression.
929 #[derive(Clone, Encodable, Decodable, Debug, Copy)]
931 /// The `*` operator for dereferencing
933 /// The `!` operator for logical inversion
935 /// The `-` operator for negation
940 pub fn to_string(op
: UnOp
) -> &'
static str {
950 #[derive(Clone, Encodable, Decodable, Debug)]
958 pub fn has_trailing_semicolon(&self) -> bool
{
960 StmtKind
::Semi(_
) => true,
961 StmtKind
::MacCall(mac
) => matches
!(mac
.style
, MacStmtStyle
::Semicolon
),
966 /// Converts a parsed `Stmt` to a `Stmt` with
967 /// a trailing semicolon.
969 /// This only modifies the parsed AST struct, not the attached
970 /// `LazyAttrTokenStream`. The parser is responsible for calling
971 /// `ToAttrTokenStream::add_trailing_semi` when there is actually
972 /// a semicolon in the tokenstream.
973 pub fn add_trailing_semicolon(mut self) -> Self {
974 self.kind
= match self.kind
{
975 StmtKind
::Expr(expr
) => StmtKind
::Semi(expr
),
976 StmtKind
::MacCall(mac
) => {
977 StmtKind
::MacCall(mac
.map(|MacCallStmt { mac, style: _, attrs, tokens }
| {
978 MacCallStmt { mac, style: MacStmtStyle::Semicolon, attrs, tokens }
987 pub fn is_item(&self) -> bool
{
988 matches
!(self.kind
, StmtKind
::Item(_
))
991 pub fn is_expr(&self) -> bool
{
992 matches
!(self.kind
, StmtKind
::Expr(_
))
996 #[derive(Clone, Encodable, Decodable, Debug)]
998 /// A local (let) binding.
1000 /// An item definition.
1002 /// Expr without trailing semi-colon.
1004 /// Expr with a trailing semi-colon.
1006 /// Just a trailing semi-colon.
1009 MacCall(P
<MacCallStmt
>),
1012 #[derive(Clone, Encodable, Decodable, Debug)]
1013 pub struct MacCallStmt
{
1014 pub mac
: P
<MacCall
>,
1015 pub style
: MacStmtStyle
,
1017 pub tokens
: Option
<LazyAttrTokenStream
>,
1020 #[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug)]
1021 pub enum MacStmtStyle
{
1022 /// The macro statement had a trailing semicolon (e.g., `foo! { ... };`
1023 /// `foo!(...);`, `foo![...];`).
1025 /// The macro statement had braces (e.g., `foo! { ... }`).
1027 /// The macro statement had parentheses or brackets and no semicolon (e.g.,
1028 /// `foo!(...)`). All of these will end up being converted into macro
1033 /// Local represents a `let` statement, e.g., `let <pat>:<ty> = <expr>;`.
1034 #[derive(Clone, Encodable, Decodable, Debug)]
1038 pub ty
: Option
<P
<Ty
>>,
1039 pub kind
: LocalKind
,
1042 pub tokens
: Option
<LazyAttrTokenStream
>,
1045 #[derive(Clone, Encodable, Decodable, Debug)]
1046 pub enum LocalKind
{
1047 /// Local declaration.
1048 /// Example: `let x;`
1050 /// Local declaration with an initializer.
1051 /// Example: `let x = y;`
1053 /// Local declaration with an initializer and an `else` clause.
1054 /// Example: `let Some(x) = y else { return };`
1055 InitElse(P
<Expr
>, P
<Block
>),
1059 pub fn init(&self) -> Option
<&Expr
> {
1062 Self::Init(i
) | Self::InitElse(i
, _
) => Some(i
),
1066 pub fn init_else_opt(&self) -> Option
<(&Expr
, Option
<&Block
>)> {
1069 Self::Init(init
) => Some((init
, None
)),
1070 Self::InitElse(init
, els
) => Some((init
, Some(els
))),
1075 /// An arm of a 'match'.
1077 /// E.g., `0..=10 => { println!("match!") }` as in
1081 /// 0..=10 => { println!("match!") },
1082 /// _ => { println!("no match!") },
1085 #[derive(Clone, Encodable, Decodable, Debug)]
1088 /// Match arm pattern, e.g. `10` in `match foo { 10 => {}, _ => {} }`
1090 /// Match arm guard, e.g. `n > 10` in `match foo { n if n > 10 => {}, _ => {} }`
1091 pub guard
: Option
<P
<Expr
>>,
1096 pub is_placeholder
: bool
,
1099 /// A single field in a struct expression, e.g. `x: value` and `y` in `Foo { x: value, y }`.
1100 #[derive(Clone, Encodable, Decodable, Debug)]
1101 pub struct ExprField
{
1107 pub is_shorthand
: bool
,
1108 pub is_placeholder
: bool
,
1111 #[derive(Clone, PartialEq, Encodable, Decodable, Debug, Copy)]
1112 pub enum BlockCheckMode
{
1114 Unsafe(UnsafeSource
),
1117 #[derive(Clone, PartialEq, Encodable, Decodable, Debug, Copy)]
1118 pub enum UnsafeSource
{
1123 /// A constant (expression) that's not an item or associated item,
1124 /// but needs its own `DefId` for type-checking, const-eval, etc.
1125 /// These are usually found nested inside types (e.g., array lengths)
1126 /// or expressions (e.g., repeat counts), and also used to define
1127 /// explicit discriminant values for enum variants.
1128 #[derive(Clone, Encodable, Decodable, Debug)]
1129 pub struct AnonConst
{
1135 #[derive(Clone, Encodable, Decodable, Debug)]
1141 pub tokens
: Option
<LazyAttrTokenStream
>,
1145 /// Is this expr either `N`, or `{ N }`.
1147 /// If this is not the case, name resolution does not resolve `N` when using
1148 /// `min_const_generics` as more complex expressions are not supported.
1149 pub fn is_potential_trivial_const_param(&self) -> bool
{
1150 let this
= if let ExprKind
::Block(block
, None
) = &self.kind
1151 && block
.stmts
.len() == 1
1152 && let StmtKind
::Expr(expr
) = &block
.stmts
[0].kind
1159 if let ExprKind
::Path(None
, path
) = &this
.kind
1160 && path
.segments
.len() == 1
1161 && path
.segments
[0].args
.is_none()
1169 pub fn to_bound(&self) -> Option
<GenericBound
> {
1171 ExprKind
::Path(None
, path
) => Some(GenericBound
::Trait(
1172 PolyTraitRef
::new(Vec
::new(), path
.clone(), self.span
),
1173 TraitBoundModifier
::None
,
1179 pub fn peel_parens(&self) -> &Expr
{
1180 let mut expr
= self;
1181 while let ExprKind
::Paren(inner
) = &expr
.kind
{
1187 /// Attempts to reparse as `Ty` (for diagnostic purposes).
1188 pub fn to_ty(&self) -> Option
<P
<Ty
>> {
1189 let kind
= match &self.kind
{
1190 // Trivial conversions.
1191 ExprKind
::Path(qself
, path
) => TyKind
::Path(qself
.clone(), path
.clone()),
1192 ExprKind
::MacCall(mac
) => TyKind
::MacCall(mac
.clone()),
1194 ExprKind
::Paren(expr
) => expr
.to_ty().map(TyKind
::Paren
)?
,
1196 ExprKind
::AddrOf(BorrowKind
::Ref
, mutbl
, expr
) => {
1197 expr
.to_ty().map(|ty
| TyKind
::Rptr(None
, MutTy { ty, mutbl: *mutbl }
))?
1200 ExprKind
::Repeat(expr
, expr_len
) => {
1201 expr
.to_ty().map(|ty
| TyKind
::Array(ty
, expr_len
.clone()))?
1204 ExprKind
::Array(exprs
) if exprs
.len() == 1 => exprs
[0].to_ty().map(TyKind
::Slice
)?
,
1206 ExprKind
::Tup(exprs
) => {
1207 let tys
= exprs
.iter().map(|expr
| expr
.to_ty()).collect
::<Option
<Vec
<_
>>>()?
;
1211 // If binary operator is `Add` and both `lhs` and `rhs` are trait bounds,
1212 // then type of result is trait object.
1213 // Otherwise we don't assume the result type.
1214 ExprKind
::Binary(binop
, lhs
, rhs
) if binop
.node
== BinOpKind
::Add
=> {
1215 if let (Some(lhs
), Some(rhs
)) = (lhs
.to_bound(), rhs
.to_bound()) {
1216 TyKind
::TraitObject(vec
![lhs
, rhs
], TraitObjectSyntax
::None
)
1222 ExprKind
::Underscore
=> TyKind
::Infer
,
1224 // This expression doesn't look like a type syntactically.
1228 Some(P(Ty { kind, id: self.id, span: self.span, tokens: None }
))
1231 pub fn precedence(&self) -> ExprPrecedence
{
1233 ExprKind
::Box(_
) => ExprPrecedence
::Box
,
1234 ExprKind
::Array(_
) => ExprPrecedence
::Array
,
1235 ExprKind
::ConstBlock(_
) => ExprPrecedence
::ConstBlock
,
1236 ExprKind
::Call(..) => ExprPrecedence
::Call
,
1237 ExprKind
::MethodCall(..) => ExprPrecedence
::MethodCall
,
1238 ExprKind
::Tup(_
) => ExprPrecedence
::Tup
,
1239 ExprKind
::Binary(op
, ..) => ExprPrecedence
::Binary(op
.node
),
1240 ExprKind
::Unary(..) => ExprPrecedence
::Unary
,
1241 ExprKind
::Lit(_
) | ExprKind
::IncludedBytes(..) => ExprPrecedence
::Lit
,
1242 ExprKind
::Type(..) | ExprKind
::Cast(..) => ExprPrecedence
::Cast
,
1243 ExprKind
::Let(..) => ExprPrecedence
::Let
,
1244 ExprKind
::If(..) => ExprPrecedence
::If
,
1245 ExprKind
::While(..) => ExprPrecedence
::While
,
1246 ExprKind
::ForLoop(..) => ExprPrecedence
::ForLoop
,
1247 ExprKind
::Loop(..) => ExprPrecedence
::Loop
,
1248 ExprKind
::Match(..) => ExprPrecedence
::Match
,
1249 ExprKind
::Closure(..) => ExprPrecedence
::Closure
,
1250 ExprKind
::Block(..) => ExprPrecedence
::Block
,
1251 ExprKind
::TryBlock(..) => ExprPrecedence
::TryBlock
,
1252 ExprKind
::Async(..) => ExprPrecedence
::Async
,
1253 ExprKind
::Await(..) => ExprPrecedence
::Await
,
1254 ExprKind
::Assign(..) => ExprPrecedence
::Assign
,
1255 ExprKind
::AssignOp(..) => ExprPrecedence
::AssignOp
,
1256 ExprKind
::Field(..) => ExprPrecedence
::Field
,
1257 ExprKind
::Index(..) => ExprPrecedence
::Index
,
1258 ExprKind
::Range(..) => ExprPrecedence
::Range
,
1259 ExprKind
::Underscore
=> ExprPrecedence
::Path
,
1260 ExprKind
::Path(..) => ExprPrecedence
::Path
,
1261 ExprKind
::AddrOf(..) => ExprPrecedence
::AddrOf
,
1262 ExprKind
::Break(..) => ExprPrecedence
::Break
,
1263 ExprKind
::Continue(..) => ExprPrecedence
::Continue
,
1264 ExprKind
::Ret(..) => ExprPrecedence
::Ret
,
1265 ExprKind
::InlineAsm(..) => ExprPrecedence
::InlineAsm
,
1266 ExprKind
::MacCall(..) => ExprPrecedence
::Mac
,
1267 ExprKind
::Struct(..) => ExprPrecedence
::Struct
,
1268 ExprKind
::Repeat(..) => ExprPrecedence
::Repeat
,
1269 ExprKind
::Paren(..) => ExprPrecedence
::Paren
,
1270 ExprKind
::Try(..) => ExprPrecedence
::Try
,
1271 ExprKind
::Yield(..) => ExprPrecedence
::Yield
,
1272 ExprKind
::Yeet(..) => ExprPrecedence
::Yeet
,
1273 ExprKind
::Err
=> ExprPrecedence
::Err
,
1277 pub fn take(&mut self) -> Self {
1282 kind
: ExprKind
::Err
,
1284 attrs
: AttrVec
::new(),
1290 /// To a first-order approximation, is this a pattern?
1291 pub fn is_approximately_pattern(&self) -> bool
{
1292 match &self.peel_parens().kind
{
1294 | ExprKind
::Array(_
)
1295 | ExprKind
::Call(_
, _
)
1298 | ExprKind
::Range(_
, _
, _
)
1299 | ExprKind
::Underscore
1300 | ExprKind
::Path(_
, _
)
1301 | ExprKind
::Struct(_
) => true,
1307 #[derive(Clone, Encodable, Decodable, Debug)]
1308 pub struct Closure
{
1309 pub binder
: ClosureBinder
,
1310 pub capture_clause
: CaptureBy
,
1311 pub asyncness
: Async
,
1312 pub movability
: Movability
,
1313 pub fn_decl
: P
<FnDecl
>,
1315 /// The span of the declaration block: 'move |...| -> ...'
1316 pub fn_decl_span
: Span
,
1317 /// The span of the argument block `|...|`
1318 pub fn_arg_span
: Span
,
1321 /// Limit types of a range (inclusive or exclusive)
1322 #[derive(Copy, Clone, PartialEq, Encodable, Decodable, Debug)]
1323 pub enum RangeLimits
{
1324 /// Inclusive at the beginning, exclusive at the end
1326 /// Inclusive at the beginning and end
1330 /// A method call (e.g. `x.foo::<Bar, Baz>(a, b, c)`).
1331 #[derive(Clone, Encodable, Decodable, Debug)]
1332 pub struct MethodCall
{
1333 /// The method name and its generic arguments, e.g. `foo::<Bar, Baz>`.
1334 pub seg
: PathSegment
,
1335 /// The receiver, e.g. `x`.
1336 pub receiver
: P
<Expr
>,
1337 /// The arguments, e.g. `a, b, c`.
1338 pub args
: Vec
<P
<Expr
>>,
1339 /// The span of the function, without the dot and receiver e.g. `foo::<Bar,
1344 #[derive(Clone, Encodable, Decodable, Debug)]
1345 pub enum StructRest
{
1350 /// No trailing `..` or expression.
1354 #[derive(Clone, Encodable, Decodable, Debug)]
1355 pub struct StructExpr
{
1356 pub qself
: Option
<P
<QSelf
>>,
1358 pub fields
: Vec
<ExprField
>,
1359 pub rest
: StructRest
,
1362 #[derive(Clone, Encodable, Decodable, Debug)]
1364 /// A `box x` expression.
1366 /// An array (`[a, b, c, d]`)
1367 Array(Vec
<P
<Expr
>>),
1368 /// Allow anonymous constants from an inline `const` block
1369 ConstBlock(AnonConst
),
1372 /// The first field resolves to the function itself,
1373 /// and the second field is the list of arguments.
1374 /// This also represents calling the constructor of
1375 /// tuple-like ADTs such as tuple structs and enum variants.
1376 Call(P
<Expr
>, Vec
<P
<Expr
>>),
1377 /// A method call (e.g. `x.foo::<Bar, Baz>(a, b, c)`).
1378 MethodCall(Box
<MethodCall
>),
1379 /// A tuple (e.g., `(a, b, c, d)`).
1381 /// A binary operation (e.g., `a + b`, `a * b`).
1382 Binary(BinOp
, P
<Expr
>, P
<Expr
>),
1383 /// A unary operation (e.g., `!x`, `*x`).
1384 Unary(UnOp
, P
<Expr
>),
1385 /// A literal (e.g., `1`, `"foo"`).
1387 /// A cast (e.g., `foo as f64`).
1388 Cast(P
<Expr
>, P
<Ty
>),
1389 /// A type ascription (e.g., `42: usize`).
1390 Type(P
<Expr
>, P
<Ty
>),
1391 /// A `let pat = expr` expression that is only semantically allowed in the condition
1392 /// of `if` / `while` expressions. (e.g., `if let 0 = x { .. }`).
1394 /// `Span` represents the whole `let pat = expr` statement.
1395 Let(P
<Pat
>, P
<Expr
>, Span
),
1396 /// An `if` block, with an optional `else` block.
1398 /// `if expr { block } else { expr }`
1399 If(P
<Expr
>, P
<Block
>, Option
<P
<Expr
>>),
1400 /// A while loop, with an optional label.
1402 /// `'label: while expr { block }`
1403 While(P
<Expr
>, P
<Block
>, Option
<Label
>),
1404 /// A `for` loop, with an optional label.
1406 /// `'label: for pat in expr { block }`
1408 /// This is desugared to a combination of `loop` and `match` expressions.
1409 ForLoop(P
<Pat
>, P
<Expr
>, P
<Block
>, Option
<Label
>),
1410 /// Conditionless loop (can be exited with `break`, `continue`, or `return`).
1412 /// `'label: loop { block }`
1413 Loop(P
<Block
>, Option
<Label
>, Span
),
1414 /// A `match` block.
1415 Match(P
<Expr
>, Vec
<Arm
>),
1416 /// A closure (e.g., `move |a, b, c| a + b + c`).
1417 Closure(Box
<Closure
>),
1418 /// A block (`'label: { ... }`).
1419 Block(P
<Block
>, Option
<Label
>),
1420 /// An async block (`async move { ... }`).
1422 /// The `NodeId` is the `NodeId` for the closure that results from
1423 /// desugaring an async block, just like the NodeId field in the
1424 /// `Async::Yes` variant. This is necessary in order to create a def for the
1425 /// closure which can be used as a parent of any child defs. Defs
1426 /// created during lowering cannot be made the parent of any other
1427 /// preexisting defs.
1428 Async(CaptureBy
, NodeId
, P
<Block
>),
1429 /// An await expression (`my_future.await`).
1432 /// A try block (`try { ... }`).
1435 /// An assignment (`a = foo()`).
1436 /// The `Span` argument is the span of the `=` token.
1437 Assign(P
<Expr
>, P
<Expr
>, Span
),
1438 /// An assignment with an operator.
1441 AssignOp(BinOp
, P
<Expr
>, P
<Expr
>),
1442 /// Access of a named (e.g., `obj.foo`) or unnamed (e.g., `obj.0`) struct field.
1443 Field(P
<Expr
>, Ident
),
1444 /// An indexing operation (e.g., `foo[2]`).
1445 Index(P
<Expr
>, P
<Expr
>),
1446 /// A range (e.g., `1..2`, `1..`, `..2`, `1..=2`, `..=2`; and `..` in destructuring assignment).
1447 Range(Option
<P
<Expr
>>, Option
<P
<Expr
>>, RangeLimits
),
1448 /// An underscore, used in destructuring assignment to ignore a value.
1451 /// Variable reference, possibly containing `::` and/or type
1452 /// parameters (e.g., `foo::bar::<baz>`).
1454 /// Optionally "qualified" (e.g., `<Vec<T> as SomeTrait>::SomeType`).
1455 Path(Option
<P
<QSelf
>>, Path
),
1457 /// A referencing operation (`&a`, `&mut a`, `&raw const a` or `&raw mut a`).
1458 AddrOf(BorrowKind
, Mutability
, P
<Expr
>),
1459 /// A `break`, with an optional label to break, and an optional expression.
1460 Break(Option
<Label
>, Option
<P
<Expr
>>),
1461 /// A `continue`, with an optional label.
1462 Continue(Option
<Label
>),
1463 /// A `return`, with an optional value to be returned.
1464 Ret(Option
<P
<Expr
>>),
1466 /// Output of the `asm!()` macro.
1467 InlineAsm(P
<InlineAsm
>),
1469 /// A macro invocation; pre-expansion.
1470 MacCall(P
<MacCall
>),
1472 /// A struct literal expression.
1474 /// E.g., `Foo {x: 1, y: 2}`, or `Foo {x: 1, .. rest}`.
1475 Struct(P
<StructExpr
>),
1477 /// An array literal constructed from one repeated element.
1479 /// E.g., `[1; 5]`. The expression is the element to be
1480 /// repeated; the constant is the number of times to repeat it.
1481 Repeat(P
<Expr
>, AnonConst
),
1483 /// No-op: used solely so we can pretty-print faithfully.
1486 /// A try expression (`expr?`).
1489 /// A `yield`, with an optional value to be yielded.
1490 Yield(Option
<P
<Expr
>>),
1492 /// A `do yeet` (aka `throw`/`fail`/`bail`/`raise`/whatever),
1493 /// with an optional value to be returned.
1494 Yeet(Option
<P
<Expr
>>),
1496 /// Bytes included via `include_bytes!`
1497 /// Added for optimization purposes to avoid the need to escape
1498 /// large binary blobs - should always behave like [`ExprKind::Lit`]
1499 /// with a `ByteStr` literal.
1500 IncludedBytes(Lrc
<[u8]>),
1502 /// Placeholder for an expression that wasn't syntactically well formed in some way.
1506 /// The explicit `Self` type in a "qualified path". The actual
1507 /// path, including the trait and the associated item, is stored
1508 /// separately. `position` represents the index of the associated
1509 /// item qualified with this `Self` type.
1511 /// ```ignore (only-for-syntax-highlight)
1512 /// <Vec<T> as a::b::Trait>::AssociatedItem
1513 /// ^~~~~ ~~~~~~~~~~~~~~^
1516 /// <Vec<T>>::AssociatedItem
1520 #[derive(Clone, Encodable, Decodable, Debug)]
1524 /// The span of `a::b::Trait` in a path like `<Vec<T> as
1525 /// a::b::Trait>::AssociatedItem`; in the case where `position ==
1526 /// 0`, this is an empty span.
1527 pub path_span
: Span
,
1528 pub position
: usize,
1531 /// A capture clause used in closures and `async` blocks.
1532 #[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)]
1533 pub enum CaptureBy
{
1534 /// `move |x| y + x`.
1536 /// `move` keyword was not specified.
1540 /// The movability of a generator / closure literal:
1541 /// whether a generator contains self-references, causing it to be `!Unpin`.
1542 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Encodable, Decodable, Debug, Copy)]
1543 #[derive(HashStable_Generic)]
1544 pub enum Movability
{
1545 /// May contain self-references, `!Unpin`.
1547 /// Must not contain self-references, `Unpin`.
1551 /// Closure lifetime binder, `for<'a, 'b>` in `for<'a, 'b> |_: &'a (), _: &'b ()|`.
1552 #[derive(Clone, Encodable, Decodable, Debug)]
1553 pub enum ClosureBinder
{
1554 /// The binder is not present, all closure lifetimes are inferred.
1556 /// The binder is present.
1558 /// Span of the whole `for<>` clause
1561 /// for<'a, 'b> |_: &'a (), _: &'b ()| { ... }
1562 /// ^^^^^^^^^^^ -- this
1566 /// Lifetimes in the `for<>` closure
1569 /// for<'a, 'b> |_: &'a (), _: &'b ()| { ... }
1572 generic_params
: P
<[GenericParam
]>,
1576 /// Represents a macro invocation. The `path` indicates which macro
1577 /// is being invoked, and the `args` are arguments passed to it.
1578 #[derive(Clone, Encodable, Decodable, Debug)]
1579 pub struct MacCall
{
1581 pub args
: P
<DelimArgs
>,
1582 pub prior_type_ascription
: Option
<(Span
, bool
)>,
1586 pub fn span(&self) -> Span
{
1587 self.path
.span
.to(self.args
.dspan
.entire())
1591 /// Arguments passed to an attribute macro.
1592 #[derive(Clone, Encodable, Decodable, Debug)]
1594 /// No arguments: `#[attr]`.
1596 /// Delimited arguments: `#[attr()/[]/{}]`.
1597 Delimited(DelimArgs
),
1598 /// Arguments of a key-value attribute: `#[attr = "value"]`.
1600 /// Span of the `=` token.
1607 // The RHS of an `AttrArgs::Eq` starts out as an expression. Once macro
1608 // expansion is completed, all cases end up either as a meta item literal,
1609 // which is the form used after lowering to HIR, or as an error.
1610 #[derive(Clone, Encodable, Decodable, Debug)]
1611 pub enum AttrArgsEq
{
1617 pub fn span(&self) -> Option
<Span
> {
1619 AttrArgs
::Empty
=> None
,
1620 AttrArgs
::Delimited(args
) => Some(args
.dspan
.entire()),
1621 AttrArgs
::Eq(eq_span
, AttrArgsEq
::Ast(expr
)) => Some(eq_span
.to(expr
.span
)),
1622 AttrArgs
::Eq(_
, AttrArgsEq
::Hir(lit
)) => {
1623 unreachable
!("in literal form when getting span: {:?}", lit
);
1628 /// Tokens inside the delimiters or after `=`.
1629 /// Proc macros see these tokens, for example.
1630 pub fn inner_tokens(&self) -> TokenStream
{
1632 AttrArgs
::Empty
=> TokenStream
::default(),
1633 AttrArgs
::Delimited(args
) => args
.tokens
.clone(),
1634 AttrArgs
::Eq(_
, AttrArgsEq
::Ast(expr
)) => TokenStream
::from_ast(expr
),
1635 AttrArgs
::Eq(_
, AttrArgsEq
::Hir(lit
)) => {
1636 unreachable
!("in literal form when getting inner tokens: {:?}", lit
)
1642 impl<CTX
> HashStable
<CTX
> for AttrArgs
1644 CTX
: crate::HashStableContext
,
1646 fn hash_stable(&self, ctx
: &mut CTX
, hasher
: &mut StableHasher
) {
1647 mem
::discriminant(self).hash_stable(ctx
, hasher
);
1649 AttrArgs
::Empty
=> {}
1650 AttrArgs
::Delimited(args
) => args
.hash_stable(ctx
, hasher
),
1651 AttrArgs
::Eq(_eq_span
, AttrArgsEq
::Ast(expr
)) => {
1652 unreachable
!("hash_stable {:?}", expr
);
1654 AttrArgs
::Eq(eq_span
, AttrArgsEq
::Hir(lit
)) => {
1655 eq_span
.hash_stable(ctx
, hasher
);
1656 lit
.hash_stable(ctx
, hasher
);
1662 /// Delimited arguments, as used in `#[attr()/[]/{}]` or `mac!()/[]/{}`.
1663 #[derive(Clone, Encodable, Decodable, Debug)]
1664 pub struct DelimArgs
{
1665 pub dspan
: DelimSpan
,
1666 pub delim
: MacDelimiter
,
1667 pub tokens
: TokenStream
,
1671 /// Whether a macro with these arguments needs a semicolon
1672 /// when used as a standalone item or statement.
1673 pub fn need_semicolon(&self) -> bool
{
1674 !matches
!(self, DelimArgs { delim: MacDelimiter::Brace, .. }
)
1678 impl<CTX
> HashStable
<CTX
> for DelimArgs
1680 CTX
: crate::HashStableContext
,
1682 fn hash_stable(&self, ctx
: &mut CTX
, hasher
: &mut StableHasher
) {
1683 let DelimArgs { dspan, delim, tokens }
= self;
1684 dspan
.hash_stable(ctx
, hasher
);
1685 delim
.hash_stable(ctx
, hasher
);
1686 tokens
.hash_stable(ctx
, hasher
);
1690 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
1691 pub enum MacDelimiter
{
1698 pub fn to_token(self) -> Delimiter
{
1700 MacDelimiter
::Parenthesis
=> Delimiter
::Parenthesis
,
1701 MacDelimiter
::Bracket
=> Delimiter
::Bracket
,
1702 MacDelimiter
::Brace
=> Delimiter
::Brace
,
1706 pub fn from_token(delim
: Delimiter
) -> Option
<MacDelimiter
> {
1708 Delimiter
::Parenthesis
=> Some(MacDelimiter
::Parenthesis
),
1709 Delimiter
::Bracket
=> Some(MacDelimiter
::Bracket
),
1710 Delimiter
::Brace
=> Some(MacDelimiter
::Brace
),
1711 Delimiter
::Invisible
=> None
,
1716 /// Represents a macro definition.
1717 #[derive(Clone, Encodable, Decodable, Debug, HashStable_Generic)]
1718 pub struct MacroDef
{
1719 pub body
: P
<DelimArgs
>,
1720 /// `true` if macro was defined with `macro_rules`.
1721 pub macro_rules
: bool
,
1724 #[derive(Clone, Encodable, Decodable, Debug, Copy, Hash, Eq, PartialEq)]
1725 #[derive(HashStable_Generic)]
1727 /// A regular string, like `"foo"`.
1729 /// A raw string, like `r##"foo"##`.
1731 /// The value is the number of `#` symbols used.
1735 /// A literal in a meta item.
1736 #[derive(Clone, Encodable, Decodable, Debug, HashStable_Generic)]
1737 pub struct MetaItemLit
{
1738 /// The original literal token as written in source code.
1739 pub token_lit
: token
::Lit
,
1740 /// The "semantic" representation of the literal lowered from the original tokens.
1741 /// Strings are unescaped, hexadecimal forms are eliminated, etc.
1746 /// Similar to `MetaItemLit`, but restricted to string literals.
1747 #[derive(Clone, Copy, Encodable, Decodable, Debug)]
1749 /// The original literal token as written in source code.
1750 pub style
: StrStyle
,
1752 pub suffix
: Option
<Symbol
>,
1754 /// The unescaped "semantic" representation of the literal lowered from the original token.
1755 pub symbol_unescaped
: Symbol
,
1759 pub fn as_token_lit(&self) -> token
::Lit
{
1760 let token_kind
= match self.style
{
1761 StrStyle
::Cooked
=> token
::Str
,
1762 StrStyle
::Raw(n
) => token
::StrRaw(n
),
1764 token
::Lit
::new(token_kind
, self.symbol
, self.suffix
)
1768 /// Type of the integer literal based on provided suffix.
1769 #[derive(Clone, Copy, Encodable, Decodable, Debug, Hash, Eq, PartialEq)]
1770 #[derive(HashStable_Generic)]
1771 pub enum LitIntType
{
1780 /// Type of the float literal based on provided suffix.
1781 #[derive(Clone, Copy, Encodable, Decodable, Debug, Hash, Eq, PartialEq)]
1782 #[derive(HashStable_Generic)]
1783 pub enum LitFloatType
{
1784 /// A float literal with a suffix (`1f32` or `1E10f32`).
1786 /// A float literal without a suffix (`1.0 or 1.0E10`).
1790 /// This type is used within both `ast::MetaItemLit` and `hir::Lit`.
1792 /// Note that the entire literal (including the suffix) is considered when
1793 /// deciding the `LitKind`. This means that float literals like `1f32` are
1794 /// classified by this type as `Float`. This is different to `token::LitKind`
1795 /// which does *not* consider the suffix.
1796 #[derive(Clone, Encodable, Decodable, Debug, Hash, Eq, PartialEq, HashStable_Generic)]
1798 /// A string literal (`"foo"`). The symbol is unescaped, and so may differ
1799 /// from the original token's symbol.
1800 Str(Symbol
, StrStyle
),
1801 /// A byte string (`b"foo"`).
1803 /// A byte char (`b'f'`).
1805 /// A character literal (`'a'`).
1807 /// An integer literal (`1`).
1808 Int(u128
, LitIntType
),
1809 /// A float literal (`1.0`, `1f64` or `1E10f64`). The pre-suffix part is
1810 /// stored as a symbol rather than `f64` so that `LitKind` can impl `Eq`
1812 Float(Symbol
, LitFloatType
),
1813 /// A boolean literal (`true`, `false`).
1815 /// Placeholder for a literal that wasn't well-formed in some way.
1820 /// Returns `true` if this literal is a string.
1821 pub fn is_str(&self) -> bool
{
1822 matches
!(self, LitKind
::Str(..))
1825 /// Returns `true` if this literal is byte literal string.
1826 pub fn is_bytestr(&self) -> bool
{
1827 matches
!(self, LitKind
::ByteStr(_
))
1830 /// Returns `true` if this is a numeric literal.
1831 pub fn is_numeric(&self) -> bool
{
1832 matches
!(self, LitKind
::Int(..) | LitKind
::Float(..))
1835 /// Returns `true` if this literal has no suffix.
1836 /// Note: this will return true for literals with prefixes such as raw strings and byte strings.
1837 pub fn is_unsuffixed(&self) -> bool
{
1841 /// Returns `true` if this literal has a suffix.
1842 pub fn is_suffixed(&self) -> bool
{
1844 // suffixed variants
1845 LitKind
::Int(_
, LitIntType
::Signed(..) | LitIntType
::Unsigned(..))
1846 | LitKind
::Float(_
, LitFloatType
::Suffixed(..)) => true,
1847 // unsuffixed variants
1849 | LitKind
::ByteStr(..)
1852 | LitKind
::Int(_
, LitIntType
::Unsuffixed
)
1853 | LitKind
::Float(_
, LitFloatType
::Unsuffixed
)
1855 | LitKind
::Err
=> false,
1860 // N.B., If you change this, you'll probably want to change the corresponding
1861 // type structure in `middle/ty.rs` as well.
1862 #[derive(Clone, Encodable, Decodable, Debug)]
1865 pub mutbl
: Mutability
,
1868 /// Represents a function's signature in a trait declaration,
1869 /// trait implementation, or free function.
1870 #[derive(Clone, Encodable, Decodable, Debug)]
1872 pub header
: FnHeader
,
1873 pub decl
: P
<FnDecl
>,
1877 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
1878 #[derive(Encodable, Decodable, HashStable_Generic)]
1885 pub fn name_str(self) -> &'
static str {
1887 FloatTy
::F32
=> "f32",
1888 FloatTy
::F64
=> "f64",
1892 pub fn name(self) -> Symbol
{
1894 FloatTy
::F32
=> sym
::f32,
1895 FloatTy
::F64
=> sym
::f64,
1900 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
1901 #[derive(Encodable, Decodable, HashStable_Generic)]
1912 pub fn name_str(&self) -> &'
static str {
1914 IntTy
::Isize
=> "isize",
1916 IntTy
::I16
=> "i16",
1917 IntTy
::I32
=> "i32",
1918 IntTy
::I64
=> "i64",
1919 IntTy
::I128
=> "i128",
1923 pub fn name(&self) -> Symbol
{
1925 IntTy
::Isize
=> sym
::isize,
1926 IntTy
::I8
=> sym
::i8,
1927 IntTy
::I16
=> sym
::i16,
1928 IntTy
::I32
=> sym
::i32,
1929 IntTy
::I64
=> sym
::i64,
1930 IntTy
::I128
=> sym
::i128
,
1935 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Copy, Debug)]
1936 #[derive(Encodable, Decodable, HashStable_Generic)]
1947 pub fn name_str(&self) -> &'
static str {
1949 UintTy
::Usize
=> "usize",
1951 UintTy
::U16
=> "u16",
1952 UintTy
::U32
=> "u32",
1953 UintTy
::U64
=> "u64",
1954 UintTy
::U128
=> "u128",
1958 pub fn name(&self) -> Symbol
{
1960 UintTy
::Usize
=> sym
::usize,
1961 UintTy
::U8
=> sym
::u8,
1962 UintTy
::U16
=> sym
::u16,
1963 UintTy
::U32
=> sym
::u32,
1964 UintTy
::U64
=> sym
::u64,
1965 UintTy
::U128
=> sym
::u128
,
1970 /// A constraint on an associated type (e.g., `A = Bar` in `Foo<A = Bar>` or
1971 /// `A: TraitA + TraitB` in `Foo<A: TraitA + TraitB>`).
1972 #[derive(Clone, Encodable, Decodable, Debug)]
1973 pub struct AssocConstraint
{
1976 pub gen_args
: Option
<GenericArgs
>,
1977 pub kind
: AssocConstraintKind
,
1981 /// The kinds of an `AssocConstraint`.
1982 #[derive(Clone, Encodable, Decodable, Debug)]
1988 impl From
<P
<Ty
>> for Term
{
1989 fn from(v
: P
<Ty
>) -> Self {
1994 impl From
<AnonConst
> for Term
{
1995 fn from(v
: AnonConst
) -> Self {
2000 /// The kinds of an `AssocConstraint`.
2001 #[derive(Clone, Encodable, Decodable, Debug)]
2002 pub enum AssocConstraintKind
{
2003 /// E.g., `A = Bar`, `A = 3` in `Foo<A = Bar>` where A is an associated type.
2004 Equality { term: Term }
,
2005 /// E.g. `A: TraitA + TraitB` in `Foo<A: TraitA + TraitB>`.
2006 Bound { bounds: GenericBounds }
,
2009 #[derive(Encodable, Decodable, Debug)]
2014 pub tokens
: Option
<LazyAttrTokenStream
>,
2018 fn clone(&self) -> Self {
2019 ensure_sufficient_stack(|| Self {
2021 kind
: self.kind
.clone(),
2023 tokens
: self.tokens
.clone(),
2029 pub fn peel_refs(&self) -> &Self {
2030 let mut final_ty
= self;
2031 while let TyKind
::Rptr(_
, MutTy { ty, .. }
) = &final_ty
.kind
{
2038 #[derive(Clone, Encodable, Decodable, Debug)]
2039 pub struct BareFnTy
{
2040 pub unsafety
: Unsafe
,
2042 pub generic_params
: Vec
<GenericParam
>,
2043 pub decl
: P
<FnDecl
>,
2044 /// Span of the `fn(...) -> ...` part.
2045 pub decl_span
: Span
,
2048 /// The various kinds of type recognized by the compiler.
2049 #[derive(Clone, Encodable, Decodable, Debug)]
2051 /// A variable-length slice (`[T]`).
2053 /// A fixed length array (`[T; n]`).
2054 Array(P
<Ty
>, AnonConst
),
2055 /// A raw pointer (`*const T` or `*mut T`).
2057 /// A reference (`&'a T` or `&'a mut T`).
2058 Rptr(Option
<Lifetime
>, MutTy
),
2059 /// A bare function (e.g., `fn(usize) -> bool`).
2060 BareFn(P
<BareFnTy
>),
2061 /// The never type (`!`).
2063 /// A tuple (`(A, B, C, D,...)`).
2065 /// A path (`module::module::...::Type`), optionally
2066 /// "qualified", e.g., `<Vec<T> as SomeTrait>::SomeType`.
2068 /// Type parameters are stored in the `Path` itself.
2069 Path(Option
<P
<QSelf
>>, Path
),
2070 /// A trait object type `Bound1 + Bound2 + Bound3`
2071 /// where `Bound` is a trait or a lifetime.
2072 TraitObject(GenericBounds
, TraitObjectSyntax
),
2073 /// An `impl Bound1 + Bound2 + Bound3` type
2074 /// where `Bound` is a trait or a lifetime.
2076 /// The `NodeId` exists to prevent lowering from having to
2077 /// generate `NodeId`s on the fly, which would complicate
2078 /// the generation of opaque `type Foo = impl Trait` items significantly.
2079 ImplTrait(NodeId
, GenericBounds
),
2080 /// No-op; kept solely so that we can pretty-print faithfully.
2084 /// This means the type should be inferred instead of it having been
2085 /// specified. This can appear anywhere in a type.
2087 /// Inferred type of a `self` or `&self` argument in a method.
2089 /// A macro in the type position.
2090 MacCall(P
<MacCall
>),
2091 /// Placeholder for a kind that has failed to be defined.
2093 /// Placeholder for a `va_list`.
2098 pub fn is_implicit_self(&self) -> bool
{
2099 matches
!(self, TyKind
::ImplicitSelf
)
2102 pub fn is_unit(&self) -> bool
{
2103 matches
!(self, TyKind
::Tup(tys
) if tys
.is_empty())
2106 pub fn is_simple_path(&self) -> Option
<Symbol
> {
2107 if let TyKind
::Path(None
, Path { segments, .. }
) = &self
2108 && let [segment
] = &segments
[..]
2109 && segment
.args
.is_none()
2111 Some(segment
.ident
.name
)
2118 /// Syntax used to declare a trait object.
2119 #[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)]
2120 pub enum TraitObjectSyntax
{
2126 /// Inline assembly operand explicit register or register class.
2128 /// E.g., `"eax"` as in `asm!("mov eax, 2", out("eax") result)`.
2129 #[derive(Clone, Copy, Encodable, Decodable, Debug)]
2130 pub enum InlineAsmRegOrRegClass
{
2135 bitflags
::bitflags
! {
2136 #[derive(Encodable, Decodable, HashStable_Generic)]
2137 pub struct InlineAsmOptions
: u16 {
2138 const PURE
= 1 << 0;
2139 const NOMEM
= 1 << 1;
2140 const READONLY
= 1 << 2;
2141 const PRESERVES_FLAGS
= 1 << 3;
2142 const NORETURN
= 1 << 4;
2143 const NOSTACK
= 1 << 5;
2144 const ATT_SYNTAX
= 1 << 6;
2146 const MAY_UNWIND
= 1 << 8;
2150 #[derive(Clone, PartialEq, Encodable, Decodable, Debug, Hash, HashStable_Generic)]
2151 pub enum InlineAsmTemplatePiece
{
2153 Placeholder { operand_idx: usize, modifier: Option<char>, span: Span }
,
2156 impl fmt
::Display
for InlineAsmTemplatePiece
{
2157 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
2159 Self::String(s
) => {
2160 for c
in s
.chars() {
2162 '
{'
=> f
.write_str("{{")?
,
2163 '
}'
=> f
.write_str("}}")?
,
2169 Self::Placeholder { operand_idx, modifier: Some(modifier), .. }
=> {
2170 write
!(f
, "{{{}:{}}}", operand_idx
, modifier
)
2172 Self::Placeholder { operand_idx, modifier: None, .. }
=> {
2173 write
!(f
, "{{{}}}", operand_idx
)
2179 impl InlineAsmTemplatePiece
{
2180 /// Rebuilds the asm template string from its pieces.
2181 pub fn to_string(s
: &[Self]) -> String
{
2183 let mut out
= String
::new();
2185 let _
= write
!(out
, "{}", p
);
2191 /// Inline assembly symbol operands get their own AST node that is somewhat
2192 /// similar to `AnonConst`.
2194 /// The main difference is that we specifically don't assign it `DefId` in
2195 /// `DefCollector`. Instead this is deferred until AST lowering where we
2196 /// lower it to an `AnonConst` (for functions) or a `Path` (for statics)
2197 /// depending on what the path resolves to.
2198 #[derive(Clone, Encodable, Decodable, Debug)]
2199 pub struct InlineAsmSym
{
2201 pub qself
: Option
<P
<QSelf
>>,
2205 /// Inline assembly operand.
2207 /// E.g., `out("eax") result` as in `asm!("mov eax, 2", out("eax") result)`.
2208 #[derive(Clone, Encodable, Decodable, Debug)]
2209 pub enum InlineAsmOperand
{
2211 reg
: InlineAsmRegOrRegClass
,
2215 reg
: InlineAsmRegOrRegClass
,
2217 expr
: Option
<P
<Expr
>>,
2220 reg
: InlineAsmRegOrRegClass
,
2225 reg
: InlineAsmRegOrRegClass
,
2228 out_expr
: Option
<P
<Expr
>>,
2231 anon_const
: AnonConst
,
2238 /// Inline assembly.
2240 /// E.g., `asm!("NOP");`.
2241 #[derive(Clone, Encodable, Decodable, Debug)]
2242 pub struct InlineAsm
{
2243 pub template
: Vec
<InlineAsmTemplatePiece
>,
2244 pub template_strs
: Box
<[(Symbol
, Option
<Symbol
>, Span
)]>,
2245 pub operands
: Vec
<(InlineAsmOperand
, Span
)>,
2246 pub clobber_abis
: Vec
<(Symbol
, Span
)>,
2247 pub options
: InlineAsmOptions
,
2248 pub line_spans
: Vec
<Span
>,
2251 /// A parameter in a function header.
2253 /// E.g., `bar: usize` as in `fn foo(bar: usize)`.
2254 #[derive(Clone, Encodable, Decodable, Debug)]
2261 pub is_placeholder
: bool
,
2264 /// Alternative representation for `Arg`s describing `self` parameter of methods.
2266 /// E.g., `&mut self` as in `fn foo(&mut self)`.
2267 #[derive(Clone, Encodable, Decodable, Debug)]
2269 /// `self`, `mut self`
2271 /// `&'lt self`, `&'lt mut self`
2272 Region(Option
<Lifetime
>, Mutability
),
2273 /// `self: TYPE`, `mut self: TYPE`
2274 Explicit(P
<Ty
>, Mutability
),
2277 pub type ExplicitSelf
= Spanned
<SelfKind
>;
2280 /// Attempts to cast parameter to `ExplicitSelf`.
2281 pub fn to_self(&self) -> Option
<ExplicitSelf
> {
2282 if let PatKind
::Ident(BindingAnnotation(ByRef
::No
, mutbl
), ident
, _
) = self.pat
.kind
{
2283 if ident
.name
== kw
::SelfLower
{
2284 return match self.ty
.kind
{
2285 TyKind
::ImplicitSelf
=> Some(respan(self.pat
.span
, SelfKind
::Value(mutbl
))),
2286 TyKind
::Rptr(lt
, MutTy { ref ty, mutbl }
) if ty
.kind
.is_implicit_self() => {
2287 Some(respan(self.pat
.span
, SelfKind
::Region(lt
, mutbl
)))
2290 self.pat
.span
.to(self.ty
.span
),
2291 SelfKind
::Explicit(self.ty
.clone(), mutbl
),
2299 /// Returns `true` if parameter is `self`.
2300 pub fn is_self(&self) -> bool
{
2301 if let PatKind
::Ident(_
, ident
, _
) = self.pat
.kind
{
2302 ident
.name
== kw
::SelfLower
2308 /// Builds a `Param` object from `ExplicitSelf`.
2309 pub fn from_self(attrs
: AttrVec
, eself
: ExplicitSelf
, eself_ident
: Ident
) -> Param
{
2310 let span
= eself
.span
.to(eself_ident
.span
);
2311 let infer_ty
= P(Ty { id: DUMMY_NODE_ID, kind: TyKind::ImplicitSelf, span, tokens: None }
);
2312 let (mutbl
, ty
) = match eself
.node
{
2313 SelfKind
::Explicit(ty
, mutbl
) => (mutbl
, ty
),
2314 SelfKind
::Value(mutbl
) => (mutbl
, infer_ty
),
2315 SelfKind
::Region(lt
, mutbl
) => (
2319 kind
: TyKind
::Rptr(lt
, MutTy { ty: infer_ty, mutbl }
),
2329 kind
: PatKind
::Ident(BindingAnnotation(ByRef
::No
, mutbl
), eself_ident
, None
),
2336 is_placeholder
: false,
2341 /// A signature (not the body) of a function declaration.
2343 /// E.g., `fn foo(bar: baz)`.
2345 /// Please note that it's different from `FnHeader` structure
2346 /// which contains metadata about function safety, asyncness, constness and ABI.
2347 #[derive(Clone, Encodable, Decodable, Debug)]
2349 pub inputs
: Vec
<Param
>,
2350 pub output
: FnRetTy
,
2354 pub fn has_self(&self) -> bool
{
2355 self.inputs
.get(0).map_or(false, Param
::is_self
)
2357 pub fn c_variadic(&self) -> bool
{
2358 self.inputs
.last().map_or(false, |arg
| matches
!(arg
.ty
.kind
, TyKind
::CVarArgs
))
2362 /// Is the trait definition an auto trait?
2363 #[derive(Copy, Clone, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)]
2369 #[derive(Copy, Clone, PartialEq, Eq, Hash, Encodable, Decodable, Debug)]
2370 #[derive(HashStable_Generic)]
2376 #[derive(Copy, Clone, Encodable, Decodable, Debug)]
2378 Yes { span: Span, closure_id: NodeId, return_impl_trait_id: NodeId }
,
2383 pub fn is_async(self) -> bool
{
2384 matches
!(self, Async
::Yes { .. }
)
2387 /// In this case this is an `async` return, the `NodeId` for the generated `impl Trait` item.
2388 pub fn opt_return_id(self) -> Option
<(NodeId
, Span
)> {
2390 Async
::Yes { return_impl_trait_id, span, .. }
=> Some((return_impl_trait_id
, span
)),
2396 #[derive(Copy, Clone, PartialEq, Eq, Hash, Encodable, Decodable, Debug)]
2397 #[derive(HashStable_Generic)]
2403 /// Item defaultness.
2404 /// For details see the [RFC #2532](https://github.com/rust-lang/rfcs/pull/2532).
2405 #[derive(Copy, Clone, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)]
2406 pub enum Defaultness
{
2411 #[derive(Copy, Clone, PartialEq, Encodable, Decodable, HashStable_Generic)]
2412 pub enum ImplPolarity
{
2413 /// `impl Trait for Type`
2415 /// `impl !Trait for Type`
2419 impl fmt
::Debug
for ImplPolarity
{
2420 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
2422 ImplPolarity
::Positive
=> "positive".fmt(f
),
2423 ImplPolarity
::Negative(_
) => "negative".fmt(f
),
2428 #[derive(Clone, Encodable, Decodable, Debug)]
2430 /// Returns type is not specified.
2432 /// Functions default to `()` and closures default to inference.
2433 /// Span points to where return type would be inserted.
2435 /// Everything else.
2440 pub fn span(&self) -> Span
{
2442 &FnRetTy
::Default(span
) => span
,
2443 FnRetTy
::Ty(ty
) => ty
.span
,
2448 #[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug)]
2454 /// Module item kind.
2455 #[derive(Clone, Encodable, Decodable, Debug)]
2457 /// Module with inlined definition `mod foo { ... }`,
2458 /// or with definition outlined to a separate file `mod foo;` and already loaded from it.
2459 /// The inner span is from the first token past `{` to the last token until `}`,
2460 /// or from the first to the last token in the loaded file.
2461 Loaded(Vec
<P
<Item
>>, Inline
, ModSpans
),
2462 /// Module with definition outlined to a separate file `mod foo;` but not yet loaded from it.
2466 #[derive(Copy, Clone, Encodable, Decodable, Debug)]
2467 pub struct ModSpans
{
2468 /// `inner_span` covers the body of the module; for a file module, its the whole file.
2469 /// For an inline module, its the span inside the `{ ... }`, not including the curly braces.
2470 pub inner_span
: Span
,
2471 pub inject_use_span
: Span
,
2474 impl Default
for ModSpans
{
2475 fn default() -> ModSpans
{
2476 ModSpans { inner_span: Default::default(), inject_use_span: Default::default() }
2480 /// Foreign module declaration.
2482 /// E.g., `extern { .. }` or `extern "C" { .. }`.
2483 #[derive(Clone, Encodable, Decodable, Debug)]
2484 pub struct ForeignMod
{
2485 /// `unsafe` keyword accepted syntactically for macro DSLs, but not
2486 /// semantically by Rust.
2487 pub unsafety
: Unsafe
,
2488 pub abi
: Option
<StrLit
>,
2489 pub items
: Vec
<P
<ForeignItem
>>,
2492 #[derive(Clone, Encodable, Decodable, Debug)]
2493 pub struct EnumDef
{
2494 pub variants
: Vec
<Variant
>,
2497 #[derive(Clone, Encodable, Decodable, Debug)]
2498 pub struct Variant
{
2499 /// Attributes of the variant.
2501 /// Id of the variant (not the constructor, see `VariantData::ctor_id()`).
2505 /// The visibility of the variant. Syntactically accepted but not semantically.
2506 pub vis
: Visibility
,
2507 /// Name of the variant.
2510 /// Fields and constructor id of the variant.
2511 pub data
: VariantData
,
2512 /// Explicit discriminant, e.g., `Foo = 1`.
2513 pub disr_expr
: Option
<AnonConst
>,
2514 /// Is a macro placeholder
2515 pub is_placeholder
: bool
,
2518 /// Part of `use` item to the right of its prefix.
2519 #[derive(Clone, Encodable, Decodable, Debug)]
2520 pub enum UseTreeKind
{
2521 /// `use prefix` or `use prefix as rename`
2522 Simple(Option
<Ident
>),
2523 /// `use prefix::{...}`
2524 Nested(Vec
<(UseTree
, NodeId
)>),
2529 /// A tree of paths sharing common prefixes.
2530 /// Used in `use` items both at top-level and inside of braces in import groups.
2531 #[derive(Clone, Encodable, Decodable, Debug)]
2532 pub struct UseTree
{
2534 pub kind
: UseTreeKind
,
2539 pub fn ident(&self) -> Ident
{
2541 UseTreeKind
::Simple(Some(rename
)) => rename
,
2542 UseTreeKind
::Simple(None
) => {
2543 self.prefix
.segments
.last().expect("empty prefix in a simple import").ident
2545 _
=> panic
!("`UseTree::ident` can only be used on a simple import"),
2550 /// Distinguishes between `Attribute`s that decorate items and Attributes that
2551 /// are contained as statements within items. These two cases need to be
2552 /// distinguished for pretty-printing.
2553 #[derive(Clone, PartialEq, Encodable, Decodable, Debug, Copy, HashStable_Generic)]
2554 pub enum AttrStyle
{
2559 rustc_index
::newtype_index
! {
2562 DEBUG_FORMAT
= "AttrId({})"
2566 impl<S
: Encoder
> Encodable
<S
> for AttrId
{
2567 fn encode(&self, _s
: &mut S
) {}
2570 impl<D
: Decoder
> Decodable
<D
> for AttrId
{
2571 default fn decode(_
: &mut D
) -> AttrId
{
2572 panic
!("cannot decode `AttrId` with `{}`", std
::any
::type_name
::<D
>());
2576 /// A list of attributes.
2577 pub type AttrVec
= ThinVec
<Attribute
>;
2579 /// A syntax-level representation of an attribute.
2580 #[derive(Clone, Encodable, Decodable, Debug)]
2581 pub struct Attribute
{
2584 /// Denotes if the attribute decorates the following construct (outer)
2585 /// or the construct this attribute is contained within (inner).
2586 pub style
: AttrStyle
,
2590 #[derive(Clone, Encodable, Decodable, Debug)]
2592 /// A normal attribute.
2593 Normal(P
<NormalAttr
>),
2595 /// A doc comment (e.g. `/// ...`, `//! ...`, `/** ... */`, `/*! ... */`).
2596 /// Doc attributes (e.g. `#[doc="..."]`) are represented with the `Normal`
2597 /// variant (which is much less compact and thus more expensive).
2598 DocComment(CommentKind
, Symbol
),
2601 #[derive(Clone, Encodable, Decodable, Debug)]
2602 pub struct NormalAttr
{
2604 pub tokens
: Option
<LazyAttrTokenStream
>,
2607 #[derive(Clone, Encodable, Decodable, Debug, HashStable_Generic)]
2608 pub struct AttrItem
{
2611 pub tokens
: Option
<LazyAttrTokenStream
>,
2614 /// `TraitRef`s appear in impls.
2616 /// Resolution maps each `TraitRef`'s `ref_id` to its defining trait; that's all
2617 /// that the `ref_id` is for. The `impl_id` maps to the "self type" of this impl.
2618 /// If this impl is an `ItemKind::Impl`, the `impl_id` is redundant (it could be the
2619 /// same as the impl's `NodeId`).
2620 #[derive(Clone, Encodable, Decodable, Debug)]
2621 pub struct TraitRef
{
2626 #[derive(Clone, Encodable, Decodable, Debug)]
2627 pub struct PolyTraitRef
{
2628 /// The `'a` in `for<'a> Foo<&'a T>`.
2629 pub bound_generic_params
: Vec
<GenericParam
>,
2631 /// The `Foo<&'a T>` in `<'a> Foo<&'a T>`.
2632 pub trait_ref
: TraitRef
,
2638 pub fn new(generic_params
: Vec
<GenericParam
>, path
: Path
, span
: Span
) -> Self {
2640 bound_generic_params
: generic_params
,
2641 trait_ref
: TraitRef { path, ref_id: DUMMY_NODE_ID }
,
2647 #[derive(Clone, Encodable, Decodable, Debug)]
2648 pub struct Visibility
{
2649 pub kind
: VisibilityKind
,
2651 pub tokens
: Option
<LazyAttrTokenStream
>,
2654 #[derive(Clone, Encodable, Decodable, Debug)]
2655 pub enum VisibilityKind
{
2657 Restricted { path: P<Path>, id: NodeId, shorthand: bool }
,
2661 impl VisibilityKind
{
2662 pub fn is_pub(&self) -> bool
{
2663 matches
!(self, VisibilityKind
::Public
)
2667 /// Field definition in a struct, variant or union.
2669 /// E.g., `bar: usize` as in `struct Foo { bar: usize }`.
2670 #[derive(Clone, Encodable, Decodable, Debug)]
2671 pub struct FieldDef
{
2675 pub vis
: Visibility
,
2676 pub ident
: Option
<Ident
>,
2679 pub is_placeholder
: bool
,
2682 /// Fields and constructor ids of enum variants and structs.
2683 #[derive(Clone, Encodable, Decodable, Debug)]
2684 pub enum VariantData
{
2687 /// E.g., `Bar { .. }` as in `enum Foo { Bar { .. } }`.
2688 Struct(Vec
<FieldDef
>, bool
),
2691 /// E.g., `Bar(..)` as in `enum Foo { Bar(..) }`.
2692 Tuple(Vec
<FieldDef
>, NodeId
),
2695 /// E.g., `Bar = ..` as in `enum Foo { Bar = .. }`.
2700 /// Return the fields of this variant.
2701 pub fn fields(&self) -> &[FieldDef
] {
2703 VariantData
::Struct(fields
, ..) | VariantData
::Tuple(fields
, _
) => fields
,
2708 /// Return the `NodeId` of this variant's constructor, if it has one.
2709 pub fn ctor_node_id(&self) -> Option
<NodeId
> {
2711 VariantData
::Struct(..) => None
,
2712 VariantData
::Tuple(_
, id
) | VariantData
::Unit(id
) => Some(id
),
2717 /// An item definition.
2718 #[derive(Clone, Encodable, Decodable, Debug)]
2719 pub struct Item
<K
= ItemKind
> {
2723 pub vis
: Visibility
,
2724 /// The name of the item.
2725 /// It might be a dummy name in case of anonymous items.
2730 /// Original tokens this item was parsed from. This isn't necessarily
2731 /// available for all items, although over time more and more items should
2732 /// have this be `Some`. Right now this is primarily used for procedural
2733 /// macros, notably custom attributes.
2735 /// Note that the tokens here do not include the outer attributes, but will
2736 /// include inner attributes.
2737 pub tokens
: Option
<LazyAttrTokenStream
>,
2741 /// Return the span that encompasses the attributes.
2742 pub fn span_with_attributes(&self) -> Span
{
2743 self.attrs
.iter().fold(self.span
, |acc
, attr
| acc
.to(attr
.span
))
2747 /// `extern` qualifier on a function item or function type.
2748 #[derive(Clone, Copy, Encodable, Decodable, Debug)]
2752 Explicit(StrLit
, Span
),
2756 pub fn from_abi(abi
: Option
<StrLit
>, span
: Span
) -> Extern
{
2758 Some(name
) => Extern
::Explicit(name
, span
),
2759 None
=> Extern
::Implicit(span
),
2764 /// A function header.
2766 /// All the information between the visibility and the name of the function is
2767 /// included in this struct (e.g., `async unsafe fn` or `const extern "C" fn`).
2768 #[derive(Clone, Copy, Encodable, Decodable, Debug)]
2769 pub struct FnHeader
{
2770 pub unsafety
: Unsafe
,
2771 pub asyncness
: Async
,
2772 pub constness
: Const
,
2777 /// Does this function header have any qualifiers or is it empty?
2778 pub fn has_qualifiers(&self) -> bool
{
2779 let Self { unsafety, asyncness, constness, ext }
= self;
2780 matches
!(unsafety
, Unsafe
::Yes(_
))
2781 || asyncness
.is_async()
2782 || matches
!(constness
, Const
::Yes(_
))
2783 || !matches
!(ext
, Extern
::None
)
2787 impl Default
for FnHeader
{
2788 fn default() -> FnHeader
{
2790 unsafety
: Unsafe
::No
,
2791 asyncness
: Async
::No
,
2792 constness
: Const
::No
,
2798 #[derive(Clone, Encodable, Decodable, Debug)]
2800 pub unsafety
: Unsafe
,
2801 pub is_auto
: IsAuto
,
2802 pub generics
: Generics
,
2803 pub bounds
: GenericBounds
,
2804 pub items
: Vec
<P
<AssocItem
>>,
2807 /// The location of a where clause on a `TyAlias` (`Span`) and whether there was
2808 /// a `where` keyword (`bool`). This is split out from `WhereClause`, since there
2809 /// are two locations for where clause on type aliases, but their predicates
2810 /// are concatenated together.
2812 /// Take this example:
2813 /// ```ignore (only-for-syntax-highlight)
2815 /// type Assoc<'a, 'b> where Self: 'a, Self: 'b;
2817 /// impl Foo for () {
2818 /// type Assoc<'a, 'b> where Self: 'a = () where Self: 'b;
2819 /// // ^^^^^^^^^^^^^^ first where clause
2820 /// // ^^^^^^^^^^^^^^ second where clause
2824 /// If there is no where clause, then this is `false` with `DUMMY_SP`.
2825 #[derive(Copy, Clone, Encodable, Decodable, Debug, Default)]
2826 pub struct TyAliasWhereClause(pub bool
, pub Span
);
2828 #[derive(Clone, Encodable, Decodable, Debug)]
2829 pub struct TyAlias
{
2830 pub defaultness
: Defaultness
,
2831 pub generics
: Generics
,
2832 /// The span information for the two where clauses (before equals, after equals)
2833 pub where_clauses
: (TyAliasWhereClause
, TyAliasWhereClause
),
2834 /// The index in `generics.where_clause.predicates` that would split into
2835 /// predicates from the where clause before the equals and the predicates
2836 /// from the where clause after the equals
2837 pub where_predicates_split
: usize,
2838 pub bounds
: GenericBounds
,
2839 pub ty
: Option
<P
<Ty
>>,
2842 #[derive(Clone, Encodable, Decodable, Debug)]
2844 pub defaultness
: Defaultness
,
2845 pub unsafety
: Unsafe
,
2846 pub generics
: Generics
,
2847 pub constness
: Const
,
2848 pub polarity
: ImplPolarity
,
2849 /// The trait being implemented, if any.
2850 pub of_trait
: Option
<TraitRef
>,
2852 pub items
: Vec
<P
<AssocItem
>>,
2855 #[derive(Clone, Encodable, Decodable, Debug)]
2857 pub defaultness
: Defaultness
,
2858 pub generics
: Generics
,
2860 pub body
: Option
<P
<Block
>>,
2863 #[derive(Clone, Encodable, Decodable, Debug)]
2865 /// An `extern crate` item, with the optional *original* crate name if the crate was renamed.
2867 /// E.g., `extern crate foo` or `extern crate foo_bar as foo`.
2868 ExternCrate(Option
<Symbol
>),
2869 /// A use declaration item (`use`).
2871 /// E.g., `use foo;`, `use foo::bar;` or `use foo::bar as FooBar;`.
2873 /// A static item (`static`).
2875 /// E.g., `static FOO: i32 = 42;` or `static FOO: &'static str = "bar";`.
2876 Static(P
<Ty
>, Mutability
, Option
<P
<Expr
>>),
2877 /// A constant item (`const`).
2879 /// E.g., `const FOO: i32 = 42;`.
2880 Const(Defaultness
, P
<Ty
>, Option
<P
<Expr
>>),
2881 /// A function declaration (`fn`).
2883 /// E.g., `fn foo(bar: usize) -> usize { .. }`.
2885 /// A module declaration (`mod`).
2887 /// E.g., `mod foo;` or `mod foo { .. }`.
2888 /// `unsafe` keyword on modules is accepted syntactically for macro DSLs, but not
2889 /// semantically by Rust.
2890 Mod(Unsafe
, ModKind
),
2891 /// An external module (`extern`).
2893 /// E.g., `extern {}` or `extern "C" {}`.
2894 ForeignMod(ForeignMod
),
2895 /// Module-level inline assembly (from `global_asm!()`).
2896 GlobalAsm(Box
<InlineAsm
>),
2897 /// A type alias (`type`).
2899 /// E.g., `type Foo = Bar<u8>;`.
2900 TyAlias(Box
<TyAlias
>),
2901 /// An enum definition (`enum`).
2903 /// E.g., `enum Foo<A, B> { C<A>, D<B> }`.
2904 Enum(EnumDef
, Generics
),
2905 /// A struct definition (`struct`).
2907 /// E.g., `struct Foo<A> { x: A }`.
2908 Struct(VariantData
, Generics
),
2909 /// A union definition (`union`).
2911 /// E.g., `union Foo<A, B> { x: A, y: B }`.
2912 Union(VariantData
, Generics
),
2913 /// A trait declaration (`trait`).
2915 /// E.g., `trait Foo { .. }`, `trait Foo<T> { .. }` or `auto trait Foo {}`.
2919 /// E.g., `trait Foo = Bar + Quux;`.
2920 TraitAlias(Generics
, GenericBounds
),
2921 /// An implementation.
2923 /// E.g., `impl<A> Foo<A> { .. }` or `impl<A> Trait for Foo<A> { .. }`.
2925 /// A macro invocation.
2927 /// E.g., `foo!(..)`.
2928 MacCall(P
<MacCall
>),
2930 /// A macro definition.
2935 pub fn article(&self) -> &str {
2938 Use(..) | Static(..) | Const(..) | Fn(..) | Mod(..) | GlobalAsm(..) | TyAlias(..)
2939 | Struct(..) | Union(..) | Trait(..) | TraitAlias(..) | MacroDef(..) => "a",
2940 ExternCrate(..) | ForeignMod(..) | MacCall(..) | Enum(..) | Impl { .. }
=> "an",
2944 pub fn descr(&self) -> &str {
2946 ItemKind
::ExternCrate(..) => "extern crate",
2947 ItemKind
::Use(..) => "`use` import",
2948 ItemKind
::Static(..) => "static item",
2949 ItemKind
::Const(..) => "constant item",
2950 ItemKind
::Fn(..) => "function",
2951 ItemKind
::Mod(..) => "module",
2952 ItemKind
::ForeignMod(..) => "extern block",
2953 ItemKind
::GlobalAsm(..) => "global asm item",
2954 ItemKind
::TyAlias(..) => "type alias",
2955 ItemKind
::Enum(..) => "enum",
2956 ItemKind
::Struct(..) => "struct",
2957 ItemKind
::Union(..) => "union",
2958 ItemKind
::Trait(..) => "trait",
2959 ItemKind
::TraitAlias(..) => "trait alias",
2960 ItemKind
::MacCall(..) => "item macro invocation",
2961 ItemKind
::MacroDef(..) => "macro definition",
2962 ItemKind
::Impl { .. }
=> "implementation",
2966 pub fn generics(&self) -> Option
<&Generics
> {
2968 Self::Fn(box Fn { generics, .. }
)
2969 | Self::TyAlias(box TyAlias { generics, .. }
)
2970 | Self::Enum(_
, generics
)
2971 | Self::Struct(_
, generics
)
2972 | Self::Union(_
, generics
)
2973 | Self::Trait(box Trait { generics, .. }
)
2974 | Self::TraitAlias(generics
, _
)
2975 | Self::Impl(box Impl { generics, .. }
) => Some(generics
),
2981 /// Represents associated items.
2982 /// These include items in `impl` and `trait` definitions.
2983 pub type AssocItem
= Item
<AssocItemKind
>;
2985 /// Represents associated item kinds.
2987 /// The term "provided" in the variants below refers to the item having a default
2988 /// definition / body. Meanwhile, a "required" item lacks a definition / body.
2989 /// In an implementation, all items must be provided.
2990 /// The `Option`s below denote the bodies, where `Some(_)`
2991 /// means "provided" and conversely `None` means "required".
2992 #[derive(Clone, Encodable, Decodable, Debug)]
2993 pub enum AssocItemKind
{
2994 /// An associated constant, `const $ident: $ty $def?;` where `def ::= "=" $expr? ;`.
2995 /// If `def` is parsed, then the constant is provided, and otherwise required.
2996 Const(Defaultness
, P
<Ty
>, Option
<P
<Expr
>>),
2997 /// An associated function.
2999 /// An associated type.
3001 /// A macro expanding to associated items.
3002 MacCall(P
<MacCall
>),
3005 impl AssocItemKind
{
3006 pub fn defaultness(&self) -> Defaultness
{
3008 Self::Const(defaultness
, ..)
3009 | Self::Fn(box Fn { defaultness, .. }
)
3010 | Self::Type(box TyAlias { defaultness, .. }
) => defaultness
,
3011 Self::MacCall(..) => Defaultness
::Final
,
3016 impl From
<AssocItemKind
> for ItemKind
{
3017 fn from(assoc_item_kind
: AssocItemKind
) -> ItemKind
{
3018 match assoc_item_kind
{
3019 AssocItemKind
::Const(a
, b
, c
) => ItemKind
::Const(a
, b
, c
),
3020 AssocItemKind
::Fn(fn_kind
) => ItemKind
::Fn(fn_kind
),
3021 AssocItemKind
::Type(ty_alias_kind
) => ItemKind
::TyAlias(ty_alias_kind
),
3022 AssocItemKind
::MacCall(a
) => ItemKind
::MacCall(a
),
3027 impl TryFrom
<ItemKind
> for AssocItemKind
{
3028 type Error
= ItemKind
;
3030 fn try_from(item_kind
: ItemKind
) -> Result
<AssocItemKind
, ItemKind
> {
3031 Ok(match item_kind
{
3032 ItemKind
::Const(a
, b
, c
) => AssocItemKind
::Const(a
, b
, c
),
3033 ItemKind
::Fn(fn_kind
) => AssocItemKind
::Fn(fn_kind
),
3034 ItemKind
::TyAlias(ty_kind
) => AssocItemKind
::Type(ty_kind
),
3035 ItemKind
::MacCall(a
) => AssocItemKind
::MacCall(a
),
3036 _
=> return Err(item_kind
),
3041 /// An item in `extern` block.
3042 #[derive(Clone, Encodable, Decodable, Debug)]
3043 pub enum ForeignItemKind
{
3044 /// A foreign static item (`static FOO: u8`).
3045 Static(P
<Ty
>, Mutability
, Option
<P
<Expr
>>),
3046 /// An foreign function.
3048 /// An foreign type.
3049 TyAlias(Box
<TyAlias
>),
3050 /// A macro expanding to foreign items.
3051 MacCall(P
<MacCall
>),
3054 impl From
<ForeignItemKind
> for ItemKind
{
3055 fn from(foreign_item_kind
: ForeignItemKind
) -> ItemKind
{
3056 match foreign_item_kind
{
3057 ForeignItemKind
::Static(a
, b
, c
) => ItemKind
::Static(a
, b
, c
),
3058 ForeignItemKind
::Fn(fn_kind
) => ItemKind
::Fn(fn_kind
),
3059 ForeignItemKind
::TyAlias(ty_alias_kind
) => ItemKind
::TyAlias(ty_alias_kind
),
3060 ForeignItemKind
::MacCall(a
) => ItemKind
::MacCall(a
),
3065 impl TryFrom
<ItemKind
> for ForeignItemKind
{
3066 type Error
= ItemKind
;
3068 fn try_from(item_kind
: ItemKind
) -> Result
<ForeignItemKind
, ItemKind
> {
3069 Ok(match item_kind
{
3070 ItemKind
::Static(a
, b
, c
) => ForeignItemKind
::Static(a
, b
, c
),
3071 ItemKind
::Fn(fn_kind
) => ForeignItemKind
::Fn(fn_kind
),
3072 ItemKind
::TyAlias(ty_alias_kind
) => ForeignItemKind
::TyAlias(ty_alias_kind
),
3073 ItemKind
::MacCall(a
) => ForeignItemKind
::MacCall(a
),
3074 _
=> return Err(item_kind
),
3079 pub type ForeignItem
= Item
<ForeignItemKind
>;
3081 // Some nodes are used a lot. Make sure they don't unintentionally get bigger.
3082 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
3085 use rustc_data_structures
::static_assert_size
;
3086 // tidy-alphabetical-start
3087 static_assert_size
!(AssocItem
, 104);
3088 static_assert_size
!(AssocItemKind
, 32);
3089 static_assert_size
!(Attribute
, 32);
3090 static_assert_size
!(Block
, 48);
3091 static_assert_size
!(Expr
, 72);
3092 static_assert_size
!(ExprKind
, 40);
3093 static_assert_size
!(Fn
, 184);
3094 static_assert_size
!(ForeignItem
, 96);
3095 static_assert_size
!(ForeignItemKind
, 24);
3096 static_assert_size
!(GenericArg
, 24);
3097 static_assert_size
!(GenericBound
, 72);
3098 static_assert_size
!(Generics
, 72);
3099 static_assert_size
!(Impl
, 184);
3100 static_assert_size
!(Item
, 184);
3101 static_assert_size
!(ItemKind
, 112);
3102 static_assert_size
!(LitKind
, 24);
3103 static_assert_size
!(Local
, 72);
3104 static_assert_size
!(MetaItemLit
, 48);
3105 static_assert_size
!(Param
, 40);
3106 static_assert_size
!(Pat
, 88);
3107 static_assert_size
!(Path
, 24);
3108 static_assert_size
!(PathSegment
, 24);
3109 static_assert_size
!(PatKind
, 64);
3110 static_assert_size
!(Stmt
, 32);
3111 static_assert_size
!(StmtKind
, 16);
3112 static_assert_size
!(Ty
, 64);
3113 static_assert_size
!(TyKind
, 40);
3114 // tidy-alphabetical-end