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 //! - [`Lit`] 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, DelimToken, Token}
;
27 use crate::tokenstream
::{DelimSpan, LazyTokenStream, TokenStream, TokenTree}
;
29 use rustc_data_structures
::stable_hasher
::{HashStable, StableHasher}
;
30 use rustc_data_structures
::stack
::ensure_sufficient_stack
;
31 use rustc_data_structures
::sync
::Lrc
;
32 use rustc_data_structures
::thin_vec
::ThinVec
;
33 use rustc_macros
::HashStable_Generic
;
34 use rustc_serialize
::{self, Decoder, Encoder}
;
35 use rustc_span
::source_map
::{respan, Spanned}
;
36 use rustc_span
::symbol
::{kw, sym, Ident, Symbol}
;
37 use rustc_span
::{Span, DUMMY_SP}
;
39 use std
::cmp
::Ordering
;
40 use std
::convert
::TryFrom
;
46 /// A "Label" is an identifier of some point in sources,
47 /// e.g. in the following code:
55 /// `'outer` is a label.
56 #[derive(Clone, Encodable, Decodable, Copy, HashStable_Generic)]
61 impl fmt
::Debug
for Label
{
62 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
63 write
!(f
, "label({:?})", self.ident
)
67 /// A "Lifetime" is an annotation of the scope in which variable
68 /// can be used, e.g. `'a` in `&'a i32`.
69 #[derive(Clone, Encodable, Decodable, Copy)]
75 impl fmt
::Debug
for Lifetime
{
76 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
77 write
!(f
, "lifetime({}: {})", self.id
, self)
81 impl fmt
::Display
for Lifetime
{
82 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
83 write
!(f
, "{}", self.ident
.name
)
87 /// A "Path" is essentially Rust's notion of a name.
89 /// It's represented as a sequence of identifiers,
90 /// along with a bunch of supporting information.
92 /// E.g., `std::cmp::PartialEq`.
93 #[derive(Clone, Encodable, Decodable, Debug)]
96 /// The segments in the path: the things separated by `::`.
97 /// Global paths begin with `kw::PathRoot`.
98 pub segments
: Vec
<PathSegment
>,
99 pub tokens
: Option
<LazyTokenStream
>,
102 impl PartialEq
<Symbol
> for Path
{
104 fn eq(&self, symbol
: &Symbol
) -> bool
{
105 self.segments
.len() == 1 && { self.segments[0].ident.name == *symbol }
109 impl<CTX
> HashStable
<CTX
> for Path
{
110 fn hash_stable(&self, hcx
: &mut CTX
, hasher
: &mut StableHasher
) {
111 self.segments
.len().hash_stable(hcx
, hasher
);
112 for segment
in &self.segments
{
113 segment
.ident
.name
.hash_stable(hcx
, hasher
);
119 // Convert a span and an identifier to the corresponding
121 pub fn from_ident(ident
: Ident
) -> Path
{
122 Path { segments: vec![PathSegment::from_ident(ident)], span: ident.span, tokens: None }
125 pub fn is_global(&self) -> bool
{
126 !self.segments
.is_empty() && self.segments
[0].ident
.name
== kw
::PathRoot
130 /// A segment of a path: an identifier, an optional lifetime, and a set of types.
132 /// E.g., `std`, `String` or `Box<T>`.
133 #[derive(Clone, Encodable, Decodable, Debug)]
134 pub struct PathSegment
{
135 /// The identifier portion of this path segment.
140 /// Type/lifetime parameters attached to this path. They come in
141 /// two flavors: `Path<A,B,C>` and `Path(A,B) -> C`.
142 /// `None` means that no parameter list is supplied (`Path`),
143 /// `Some` means that parameter list is supplied (`Path<X, Y>`)
144 /// but it can be empty (`Path<>`).
145 /// `P` is used as a size optimization for the common case with no parameters.
146 pub args
: Option
<P
<GenericArgs
>>,
150 pub fn from_ident(ident
: Ident
) -> Self {
151 PathSegment { ident, id: DUMMY_NODE_ID, args: None }
154 pub fn path_root(span
: Span
) -> Self {
155 PathSegment
::from_ident(Ident
::new(kw
::PathRoot
, span
))
158 pub fn span(&self) -> Span
{
160 Some(args
) => self.ident
.span
.to(args
.span()),
161 None
=> self.ident
.span
,
166 /// The arguments of a path segment.
168 /// E.g., `<A, B>` as in `Foo<A, B>` or `(A, B)` as in `Foo(A, B)`.
169 #[derive(Clone, Encodable, Decodable, Debug)]
170 pub enum GenericArgs
{
171 /// The `<'a, A, B, C>` in `foo::bar::baz::<'a, A, B, C>`.
172 AngleBracketed(AngleBracketedArgs
),
173 /// The `(A, B)` and `C` in `Foo(A, B) -> C`.
174 Parenthesized(ParenthesizedArgs
),
178 pub fn is_angle_bracketed(&self) -> bool
{
179 matches
!(self, AngleBracketed(..))
182 pub fn span(&self) -> Span
{
184 AngleBracketed(ref data
) => data
.span
,
185 Parenthesized(ref data
) => data
.span
,
190 /// Concrete argument in the sequence of generic args.
191 #[derive(Clone, Encodable, Decodable, Debug)]
192 pub enum GenericArg
{
193 /// `'a` in `Foo<'a>`
195 /// `Bar` in `Foo<Bar>`
202 pub fn span(&self) -> Span
{
204 GenericArg
::Lifetime(lt
) => lt
.ident
.span
,
205 GenericArg
::Type(ty
) => ty
.span
,
206 GenericArg
::Const(ct
) => ct
.value
.span
,
211 /// A path like `Foo<'a, T>`.
212 #[derive(Clone, Encodable, Decodable, Debug, Default)]
213 pub struct AngleBracketedArgs
{
214 /// The overall span.
216 /// The comma separated parts in the `<...>`.
217 pub args
: Vec
<AngleBracketedArg
>,
220 /// Either an argument for a parameter e.g., `'a`, `Vec<u8>`, `0`,
221 /// or a constraint on an associated item, e.g., `Item = String` or `Item: Bound`.
222 #[derive(Clone, Encodable, Decodable, Debug)]
223 pub enum AngleBracketedArg
{
224 /// Argument for a generic parameter.
226 /// Constraint for an associated item.
227 Constraint(AssocTyConstraint
),
230 impl AngleBracketedArg
{
231 pub fn span(&self) -> Span
{
233 AngleBracketedArg
::Arg(arg
) => arg
.span(),
234 AngleBracketedArg
::Constraint(constraint
) => constraint
.span
,
239 impl Into
<Option
<P
<GenericArgs
>>> for AngleBracketedArgs
{
240 fn into(self) -> Option
<P
<GenericArgs
>> {
241 Some(P(GenericArgs
::AngleBracketed(self)))
245 impl Into
<Option
<P
<GenericArgs
>>> for ParenthesizedArgs
{
246 fn into(self) -> Option
<P
<GenericArgs
>> {
247 Some(P(GenericArgs
::Parenthesized(self)))
251 /// A path like `Foo(A, B) -> C`.
252 #[derive(Clone, Encodable, Decodable, Debug)]
253 pub struct ParenthesizedArgs
{
261 pub inputs
: Vec
<P
<Ty
>>,
267 pub inputs_span
: Span
,
273 impl ParenthesizedArgs
{
274 pub fn as_angle_bracketed_args(&self) -> AngleBracketedArgs
{
279 .map(|input
| AngleBracketedArg
::Arg(GenericArg
::Type(input
)))
281 AngleBracketedArgs { span: self.inputs_span, args }
285 pub use crate::node_id
::{NodeId, CRATE_NODE_ID, DUMMY_NODE_ID}
;
287 /// A modifier on a bound, e.g., `?Sized` or `~const Trait`.
289 /// Negative bounds should also be handled here.
290 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug)]
291 pub enum TraitBoundModifier
{
303 // This parses but will be rejected during AST validation.
307 /// The AST represents all type param bounds as types.
308 /// `typeck::collect::compute_bounds` matches these against
309 /// the "special" built-in traits (see `middle::lang_items`) and
310 /// detects `Copy`, `Send` and `Sync`.
311 #[derive(Clone, Encodable, Decodable, Debug)]
312 pub enum GenericBound
{
313 Trait(PolyTraitRef
, TraitBoundModifier
),
318 pub fn span(&self) -> Span
{
320 GenericBound
::Trait(ref t
, ..) => t
.span
,
321 GenericBound
::Outlives(ref l
) => l
.ident
.span
,
326 pub type GenericBounds
= Vec
<GenericBound
>;
328 /// Specifies the enforced ordering for generic parameters. In the future,
329 /// if we wanted to relax this order, we could override `PartialEq` and
330 /// `PartialOrd`, to allow the kinds to be unordered.
331 #[derive(Hash, Clone, Copy)]
332 pub enum ParamKindOrd
{
335 // `unordered` is only `true` if `sess.unordered_const_ty_params()`
336 // returns true. Specifically, if it's only `min_const_generics`, it will still require
337 // ordering consts after types.
338 Const { unordered: bool }
,
339 // `Infer` is not actually constructed directly from the AST, but is implicitly constructed
340 // during HIR lowering, and `ParamKindOrd` will implicitly order inferred variables last.
344 impl Ord
for ParamKindOrd
{
345 fn cmp(&self, other
: &Self) -> Ordering
{
347 let to_int
= |v
| match v
{
349 Infer
| Type
| Const { unordered: true }
=> 1,
350 // technically both consts should be ordered equally,
351 // but only one is ever encountered at a time, so this is
353 Const { unordered: false }
=> 2,
356 to_int(*self).cmp(&to_int(*other
))
359 impl PartialOrd
for ParamKindOrd
{
360 fn partial_cmp(&self, other
: &Self) -> Option
<Ordering
> {
361 Some(self.cmp(other
))
364 impl PartialEq
for ParamKindOrd
{
365 fn eq(&self, other
: &Self) -> bool
{
366 self.cmp(other
) == Ordering
::Equal
369 impl Eq
for ParamKindOrd {}
371 impl fmt
::Display
for ParamKindOrd
{
372 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
374 ParamKindOrd
::Lifetime
=> "lifetime".fmt(f
),
375 ParamKindOrd
::Type
=> "type".fmt(f
),
376 ParamKindOrd
::Const { .. }
=> "const".fmt(f
),
377 ParamKindOrd
::Infer
=> "infer".fmt(f
),
382 #[derive(Clone, Encodable, Decodable, Debug)]
383 pub enum GenericParamKind
{
384 /// A lifetime definition (e.g., `'a: 'b + 'c + 'd`).
387 default: Option
<P
<Ty
>>,
391 /// Span of the `const` keyword.
393 /// Optional default value for the const generic param
394 default: Option
<AnonConst
>,
398 #[derive(Clone, Encodable, Decodable, Debug)]
399 pub struct GenericParam
{
403 pub bounds
: GenericBounds
,
404 pub is_placeholder
: bool
,
405 pub kind
: GenericParamKind
,
408 /// Represents lifetime, type and const parameters attached to a declaration of
409 /// a function, enum, trait, etc.
410 #[derive(Clone, Encodable, Decodable, Debug)]
411 pub struct Generics
{
412 pub params
: Vec
<GenericParam
>,
413 pub where_clause
: WhereClause
,
417 impl Default
for Generics
{
418 /// Creates an instance of `Generics`.
419 fn default() -> Generics
{
422 where_clause
: WhereClause
{
423 has_where_token
: false,
424 predicates
: Vec
::new(),
432 /// A where-clause in a definition.
433 #[derive(Clone, Encodable, Decodable, Debug)]
434 pub struct WhereClause
{
435 /// `true` if we ate a `where` token: this can happen
436 /// if we parsed no predicates (e.g. `struct Foo where {}`).
437 /// This allows us to accurately pretty-print
438 /// in `nt_to_tokenstream`
439 pub has_where_token
: bool
,
440 pub predicates
: Vec
<WherePredicate
>,
444 /// A single predicate in a where-clause.
445 #[derive(Clone, Encodable, Decodable, Debug)]
446 pub enum WherePredicate
{
447 /// A type binding (e.g., `for<'c> Foo: Send + Clone + 'c`).
448 BoundPredicate(WhereBoundPredicate
),
449 /// A lifetime predicate (e.g., `'a: 'b + 'c`).
450 RegionPredicate(WhereRegionPredicate
),
451 /// An equality predicate (unsupported).
452 EqPredicate(WhereEqPredicate
),
455 impl WherePredicate
{
456 pub fn span(&self) -> Span
{
458 WherePredicate
::BoundPredicate(p
) => p
.span
,
459 WherePredicate
::RegionPredicate(p
) => p
.span
,
460 WherePredicate
::EqPredicate(p
) => p
.span
,
467 /// E.g., `for<'c> Foo: Send + Clone + 'c`.
468 #[derive(Clone, Encodable, Decodable, Debug)]
469 pub struct WhereBoundPredicate
{
471 /// Any generics from a `for` binding.
472 pub bound_generic_params
: Vec
<GenericParam
>,
473 /// The type being bounded.
474 pub bounded_ty
: P
<Ty
>,
475 /// Trait and lifetime bounds (`Clone + Send + 'static`).
476 pub bounds
: GenericBounds
,
479 /// A lifetime predicate.
481 /// E.g., `'a: 'b + 'c`.
482 #[derive(Clone, Encodable, Decodable, Debug)]
483 pub struct WhereRegionPredicate
{
485 pub lifetime
: Lifetime
,
486 pub bounds
: GenericBounds
,
489 /// An equality predicate (unsupported).
492 #[derive(Clone, Encodable, Decodable, Debug)]
493 pub struct WhereEqPredicate
{
500 #[derive(Clone, Encodable, Decodable, Debug)]
502 pub attrs
: Vec
<Attribute
>,
503 pub items
: Vec
<P
<Item
>>,
507 /// Possible values inside of compile-time attribute lists.
509 /// E.g., the '..' in `#[name(..)]`.
510 #[derive(Clone, Encodable, Decodable, Debug, HashStable_Generic)]
511 pub enum NestedMetaItem
{
512 /// A full MetaItem, for recursive meta items.
516 /// E.g., `"foo"`, `64`, `true`.
520 /// A spanned compile-time attribute item.
522 /// E.g., `#[test]`, `#[derive(..)]`, `#[rustfmt::skip]` or `#[feature = "foo"]`.
523 #[derive(Clone, Encodable, Decodable, Debug, HashStable_Generic)]
524 pub struct MetaItem
{
526 pub kind
: MetaItemKind
,
530 /// A compile-time attribute item.
532 /// E.g., `#[test]`, `#[derive(..)]` or `#[feature = "foo"]`.
533 #[derive(Clone, Encodable, Decodable, Debug, HashStable_Generic)]
534 pub enum MetaItemKind
{
537 /// E.g., `test` as in `#[test]`.
541 /// E.g., `derive(..)` as in `#[derive(..)]`.
542 List(Vec
<NestedMetaItem
>),
543 /// Name value meta item.
545 /// E.g., `feature = "foo"` as in `#[feature = "foo"]`.
549 /// A block (`{ .. }`).
551 /// E.g., `{ .. }` as in `fn foo() { .. }`.
552 #[derive(Clone, Encodable, Decodable, Debug)]
554 /// The statements in the block.
555 pub stmts
: Vec
<Stmt
>,
557 /// Distinguishes between `unsafe { ... }` and `{ ... }`.
558 pub rules
: BlockCheckMode
,
560 pub tokens
: Option
<LazyTokenStream
>,
561 /// The following *isn't* a parse error, but will cause multiple errors in following stages.
568 pub could_be_bare_literal
: bool
,
573 /// Patterns appear in match statements and some other contexts, such as `let` and `if let`.
574 #[derive(Clone, Encodable, Decodable, Debug)]
579 pub tokens
: Option
<LazyTokenStream
>,
583 /// Attempt reparsing the pattern as a type.
584 /// This is intended for use by diagnostics.
585 pub fn to_ty(&self) -> Option
<P
<Ty
>> {
586 let kind
= match &self.kind
{
587 // In a type expression `_` is an inference variable.
588 PatKind
::Wild
=> TyKind
::Infer
,
589 // An IDENT pattern with no binding mode would be valid as path to a type. E.g. `u32`.
590 PatKind
::Ident(BindingMode
::ByValue(Mutability
::Not
), ident
, None
) => {
591 TyKind
::Path(None
, Path
::from_ident(*ident
))
593 PatKind
::Path(qself
, path
) => TyKind
::Path(qself
.clone(), path
.clone()),
594 PatKind
::MacCall(mac
) => TyKind
::MacCall(mac
.clone()),
595 // `&mut? P` can be reinterpreted as `&mut? T` where `T` is `P` reparsed as a type.
596 PatKind
::Ref(pat
, mutbl
) => {
597 pat
.to_ty().map(|ty
| TyKind
::Rptr(None
, MutTy { ty, mutbl: *mutbl }
))?
599 // A slice/array pattern `[P]` can be reparsed as `[T]`, an unsized array,
600 // when `P` can be reparsed as a type `T`.
601 PatKind
::Slice(pats
) if pats
.len() == 1 => pats
[0].to_ty().map(TyKind
::Slice
)?
,
602 // A tuple pattern `(P0, .., Pn)` can be reparsed as `(T0, .., Tn)`
603 // assuming `T0` to `Tn` are all syntactically valid as types.
604 PatKind
::Tuple(pats
) => {
605 let mut tys
= Vec
::with_capacity(pats
.len());
606 // FIXME(#48994) - could just be collected into an Option<Vec>
608 tys
.push(pat
.to_ty()?
);
615 Some(P(Ty { kind, id: self.id, span: self.span, tokens: None }
))
618 /// Walk top-down and call `it` in each place where a pattern occurs
619 /// starting with the root pattern `walk` is called on. If `it` returns
620 /// false then we will descend no further but siblings will be processed.
621 pub fn walk(&self, it
: &mut impl FnMut(&Pat
) -> bool
) {
627 // Walk into the pattern associated with `Ident` (if any).
628 PatKind
::Ident(_
, _
, Some(p
)) => p
.walk(it
),
630 // Walk into each field of struct.
631 PatKind
::Struct(_
, _
, fields
, _
) => fields
.iter().for_each(|field
| field
.pat
.walk(it
)),
633 // Sequence of patterns.
634 PatKind
::TupleStruct(_
, _
, s
)
637 | PatKind
::Or(s
) => s
.iter().for_each(|p
| p
.walk(it
)),
639 // Trivial wrappers over inner patterns.
640 PatKind
::Box(s
) | PatKind
::Ref(s
, _
) | PatKind
::Paren(s
) => s
.walk(it
),
642 // These patterns do not contain subpatterns, skip.
649 | PatKind
::MacCall(_
) => {}
653 /// Is this a `..` pattern?
654 pub fn is_rest(&self) -> bool
{
655 matches
!(self.kind
, PatKind
::Rest
)
659 /// A single field in a struct pattern.
661 /// Patterns like the fields of `Foo { x, ref y, ref mut z }`
662 /// are treated the same as `x: x, y: ref y, z: ref mut z`,
663 /// except when `is_shorthand` is true.
664 #[derive(Clone, Encodable, Decodable, Debug)]
665 pub struct PatField
{
666 /// The identifier for the field.
668 /// The pattern the field is destructured to.
670 pub is_shorthand
: bool
,
674 pub is_placeholder
: bool
,
677 #[derive(Clone, PartialEq, Encodable, Decodable, Debug, Copy)]
678 pub enum BindingMode
{
683 #[derive(Clone, Encodable, Decodable, Debug)]
686 Included(RangeSyntax
),
691 #[derive(Clone, Encodable, Decodable, Debug)]
692 pub enum RangeSyntax
{
699 /// All the different flavors of pattern that Rust recognizes.
700 #[derive(Clone, Encodable, Decodable, Debug)]
702 /// Represents a wildcard pattern (`_`).
705 /// A `PatKind::Ident` may either be a new bound variable (`ref mut binding @ OPT_SUBPATTERN`),
706 /// or a unit struct/variant pattern, or a const pattern (in the last two cases the third
707 /// field must be `None`). Disambiguation cannot be done with parser alone, so it happens
708 /// during name resolution.
709 Ident(BindingMode
, Ident
, Option
<P
<Pat
>>),
711 /// A struct or struct variant pattern (e.g., `Variant {x, y, ..}`).
712 /// The `bool` is `true` in the presence of a `..`.
713 Struct(Option
<QSelf
>, Path
, Vec
<PatField
>, /* recovered */ bool
),
715 /// A tuple struct/variant pattern (`Variant(x, y, .., z)`).
716 TupleStruct(Option
<QSelf
>, Path
, Vec
<P
<Pat
>>),
718 /// An or-pattern `A | B | C`.
719 /// Invariant: `pats.len() >= 2`.
722 /// A possibly qualified path pattern.
723 /// Unqualified path patterns `A::B::C` can legally refer to variants, structs, constants
724 /// or associated constants. Qualified path patterns `<A>::B::C`/`<A as Trait>::B::C` can
725 /// only legally refer to associated constants.
726 Path(Option
<QSelf
>, Path
),
728 /// A tuple pattern (`(a, b)`).
734 /// A reference pattern (e.g., `&mut (a, b)`).
735 Ref(P
<Pat
>, Mutability
),
740 /// A range pattern (e.g., `1...2`, `1..2`, `1..`, `..2`, `1..=2`, `..=2`).
741 Range(Option
<P
<Expr
>>, Option
<P
<Expr
>>, Spanned
<RangeEnd
>),
743 /// A slice pattern `[a, b, c]`.
746 /// A rest pattern `..`.
748 /// Syntactically it is valid anywhere.
750 /// Semantically however, it only has meaning immediately inside:
751 /// - a slice pattern: `[a, .., b]`,
752 /// - a binding pattern immediately inside a slice pattern: `[a, r @ ..]`,
753 /// - a tuple pattern: `(a, .., b)`,
754 /// - a tuple struct/variant pattern: `$path(a, .., b)`.
756 /// In all of these cases, an additional restriction applies,
757 /// only one rest pattern may occur in the pattern sequences.
760 /// Parentheses in patterns used for grouping (i.e., `(PAT)`).
763 /// A macro pattern; pre-expansion.
767 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Copy)]
768 #[derive(HashStable_Generic, Encodable, Decodable)]
769 pub enum Mutability
{
775 pub fn invert(self) -> Self {
777 Mutability
::Mut
=> Mutability
::Not
,
778 Mutability
::Not
=> Mutability
::Mut
,
782 pub fn prefix_str(&self) -> &'
static str {
784 Mutability
::Mut
=> "mut ",
785 Mutability
::Not
=> "",
790 /// The kind of borrow in an `AddrOf` expression,
791 /// e.g., `&place` or `&raw const place`.
792 #[derive(Clone, Copy, PartialEq, Eq, Debug)]
793 #[derive(Encodable, Decodable, HashStable_Generic)]
794 pub enum BorrowKind
{
795 /// A normal borrow, `&$expr` or `&mut $expr`.
796 /// The resulting type is either `&'a T` or `&'a mut T`
797 /// where `T = typeof($expr)` and `'a` is some lifetime.
799 /// A raw borrow, `&raw const $expr` or `&raw mut $expr`.
800 /// The resulting type is either `*const T` or `*mut T`
801 /// where `T = typeof($expr)`.
805 #[derive(Clone, PartialEq, Encodable, Decodable, Debug, Copy)]
807 /// The `+` operator (addition)
809 /// The `-` operator (subtraction)
811 /// The `*` operator (multiplication)
813 /// The `/` operator (division)
815 /// The `%` operator (modulus)
817 /// The `&&` operator (logical and)
819 /// The `||` operator (logical or)
821 /// The `^` operator (bitwise xor)
823 /// The `&` operator (bitwise and)
825 /// The `|` operator (bitwise or)
827 /// The `<<` operator (shift left)
829 /// The `>>` operator (shift right)
831 /// The `==` operator (equality)
833 /// The `<` operator (less than)
835 /// The `<=` operator (less than or equal to)
837 /// The `!=` operator (not equal to)
839 /// The `>=` operator (greater than or equal to)
841 /// The `>` operator (greater than)
846 pub fn to_string(&self) -> &'
static str {
869 pub fn lazy(&self) -> bool
{
870 matches
!(self, BinOpKind
::And
| BinOpKind
::Or
)
873 pub fn is_comparison(&self) -> bool
{
875 // Note for developers: please keep this as is;
876 // we want compilation to fail if another variant is added.
878 Eq
| Lt
| Le
| Ne
| Gt
| Ge
=> true,
879 And
| Or
| Add
| Sub
| Mul
| Div
| Rem
| BitXor
| BitAnd
| BitOr
| Shl
| Shr
=> false,
884 pub type BinOp
= Spanned
<BinOpKind
>;
888 /// Note that `&data` is not an operator, it's an `AddrOf` expression.
889 #[derive(Clone, Encodable, Decodable, Debug, Copy)]
891 /// The `*` operator for dereferencing
893 /// The `!` operator for logical inversion
895 /// The `-` operator for negation
900 pub fn to_string(op
: UnOp
) -> &'
static str {
910 #[derive(Clone, Encodable, Decodable, Debug)]
918 pub fn tokens(&self) -> Option
<&LazyTokenStream
> {
920 StmtKind
::Local(ref local
) => local
.tokens
.as_ref(),
921 StmtKind
::Item(ref item
) => item
.tokens
.as_ref(),
922 StmtKind
::Expr(ref expr
) | StmtKind
::Semi(ref expr
) => expr
.tokens
.as_ref(),
923 StmtKind
::Empty
=> None
,
924 StmtKind
::MacCall(ref mac
) => mac
.tokens
.as_ref(),
928 pub fn has_trailing_semicolon(&self) -> bool
{
930 StmtKind
::Semi(_
) => true,
931 StmtKind
::MacCall(mac
) => matches
!(mac
.style
, MacStmtStyle
::Semicolon
),
936 /// Converts a parsed `Stmt` to a `Stmt` with
937 /// a trailing semicolon.
939 /// This only modifies the parsed AST struct, not the attached
940 /// `LazyTokenStream`. The parser is responsible for calling
941 /// `CreateTokenStream::add_trailing_semi` when there is actually
942 /// a semicolon in the tokenstream.
943 pub fn add_trailing_semicolon(mut self) -> Self {
944 self.kind
= match self.kind
{
945 StmtKind
::Expr(expr
) => StmtKind
::Semi(expr
),
946 StmtKind
::MacCall(mac
) => {
947 StmtKind
::MacCall(mac
.map(|MacCallStmt { mac, style: _, attrs, tokens }
| {
948 MacCallStmt { mac, style: MacStmtStyle::Semicolon, attrs, tokens }
957 pub fn is_item(&self) -> bool
{
958 matches
!(self.kind
, StmtKind
::Item(_
))
961 pub fn is_expr(&self) -> bool
{
962 matches
!(self.kind
, StmtKind
::Expr(_
))
966 #[derive(Clone, Encodable, Decodable, Debug)]
968 /// A local (let) binding.
970 /// An item definition.
972 /// Expr without trailing semi-colon.
974 /// Expr with a trailing semi-colon.
976 /// Just a trailing semi-colon.
979 MacCall(P
<MacCallStmt
>),
982 #[derive(Clone, Encodable, Decodable, Debug)]
983 pub struct MacCallStmt
{
985 pub style
: MacStmtStyle
,
987 pub tokens
: Option
<LazyTokenStream
>,
990 #[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug)]
991 pub enum MacStmtStyle
{
992 /// The macro statement had a trailing semicolon (e.g., `foo! { ... };`
993 /// `foo!(...);`, `foo![...];`).
995 /// The macro statement had braces (e.g., `foo! { ... }`).
997 /// The macro statement had parentheses or brackets and no semicolon (e.g.,
998 /// `foo!(...)`). All of these will end up being converted into macro
1003 /// Local represents a `let` statement, e.g., `let <pat>:<ty> = <expr>;`.
1004 #[derive(Clone, Encodable, Decodable, Debug)]
1008 pub ty
: Option
<P
<Ty
>>,
1009 pub kind
: LocalKind
,
1012 pub tokens
: Option
<LazyTokenStream
>,
1015 #[derive(Clone, Encodable, Decodable, Debug)]
1016 pub enum LocalKind
{
1017 /// Local declaration.
1018 /// Example: `let x;`
1020 /// Local declaration with an initializer.
1021 /// Example: `let x = y;`
1023 /// Local declaration with an initializer and an `else` clause.
1024 /// Example: `let Some(x) = y else { return };`
1025 InitElse(P
<Expr
>, P
<Block
>),
1029 pub fn init(&self) -> Option
<&Expr
> {
1032 Self::Init(i
) | Self::InitElse(i
, _
) => Some(i
),
1036 pub fn init_else_opt(&self) -> Option
<(&Expr
, Option
<&Block
>)> {
1039 Self::Init(init
) => Some((init
, None
)),
1040 Self::InitElse(init
, els
) => Some((init
, Some(els
))),
1045 /// An arm of a 'match'.
1047 /// E.g., `0..=10 => { println!("match!") }` as in
1051 /// 0..=10 => { println!("match!") },
1052 /// _ => { println!("no match!") },
1055 #[derive(Clone, Encodable, Decodable, Debug)]
1058 /// Match arm pattern, e.g. `10` in `match foo { 10 => {}, _ => {} }`
1060 /// Match arm guard, e.g. `n > 10` in `match foo { n if n > 10 => {}, _ => {} }`
1061 pub guard
: Option
<P
<Expr
>>,
1066 pub is_placeholder
: bool
,
1069 /// A single field in a struct expression, e.g. `x: value` and `y` in `Foo { x: value, y }`.
1070 #[derive(Clone, Encodable, Decodable, Debug)]
1071 pub struct ExprField
{
1077 pub is_shorthand
: bool
,
1078 pub is_placeholder
: bool
,
1081 #[derive(Clone, PartialEq, Encodable, Decodable, Debug, Copy)]
1082 pub enum BlockCheckMode
{
1084 Unsafe(UnsafeSource
),
1087 #[derive(Clone, PartialEq, Encodable, Decodable, Debug, Copy)]
1088 pub enum UnsafeSource
{
1093 /// A constant (expression) that's not an item or associated item,
1094 /// but needs its own `DefId` for type-checking, const-eval, etc.
1095 /// These are usually found nested inside types (e.g., array lengths)
1096 /// or expressions (e.g., repeat counts), and also used to define
1097 /// explicit discriminant values for enum variants.
1098 #[derive(Clone, Encodable, Decodable, Debug)]
1099 pub struct AnonConst
{
1105 #[derive(Clone, Encodable, Decodable, Debug)]
1111 pub tokens
: Option
<LazyTokenStream
>,
1114 // `Expr` is used a lot. Make sure it doesn't unintentionally get bigger.
1115 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
1116 rustc_data_structures
::static_assert_size
!(Expr
, 104);
1119 /// Returns `true` if this expression would be valid somewhere that expects a value;
1120 /// for example, an `if` condition.
1121 pub fn returns(&self) -> bool
{
1122 if let ExprKind
::Block(ref block
, _
) = self.kind
{
1123 match block
.stmts
.last().map(|last_stmt
| &last_stmt
.kind
) {
1125 Some(StmtKind
::Expr(_
)) => true,
1126 // Last statement is an explicit return?
1127 Some(StmtKind
::Semi(expr
)) => matches
!(expr
.kind
, ExprKind
::Ret(_
)),
1128 // This is a block that doesn't end in either an implicit or explicit return.
1132 // This is not a block, it is a value.
1137 /// Is this expr either `N`, or `{ N }`.
1139 /// If this is not the case, name resolution does not resolve `N` when using
1140 /// `min_const_generics` as more complex expressions are not supported.
1141 pub fn is_potential_trivial_const_param(&self) -> bool
{
1142 let this
= if let ExprKind
::Block(ref block
, None
) = self.kind
{
1143 if block
.stmts
.len() == 1 {
1144 if let StmtKind
::Expr(ref expr
) = block
.stmts
[0].kind { expr }
else { self }
1152 if let ExprKind
::Path(None
, ref path
) = this
.kind
{
1153 if path
.segments
.len() == 1 && path
.segments
[0].args
.is_none() {
1161 pub fn to_bound(&self) -> Option
<GenericBound
> {
1163 ExprKind
::Path(None
, path
) => Some(GenericBound
::Trait(
1164 PolyTraitRef
::new(Vec
::new(), path
.clone(), self.span
),
1165 TraitBoundModifier
::None
,
1171 pub fn peel_parens(&self) -> &Expr
{
1172 let mut expr
= self;
1173 while let ExprKind
::Paren(inner
) = &expr
.kind
{
1179 /// Attempts to reparse as `Ty` (for diagnostic purposes).
1180 pub fn to_ty(&self) -> Option
<P
<Ty
>> {
1181 let kind
= match &self.kind
{
1182 // Trivial conversions.
1183 ExprKind
::Path(qself
, path
) => TyKind
::Path(qself
.clone(), path
.clone()),
1184 ExprKind
::MacCall(mac
) => TyKind
::MacCall(mac
.clone()),
1186 ExprKind
::Paren(expr
) => expr
.to_ty().map(TyKind
::Paren
)?
,
1188 ExprKind
::AddrOf(BorrowKind
::Ref
, mutbl
, expr
) => {
1189 expr
.to_ty().map(|ty
| TyKind
::Rptr(None
, MutTy { ty, mutbl: *mutbl }
))?
1192 ExprKind
::Repeat(expr
, expr_len
) => {
1193 expr
.to_ty().map(|ty
| TyKind
::Array(ty
, expr_len
.clone()))?
1196 ExprKind
::Array(exprs
) if exprs
.len() == 1 => exprs
[0].to_ty().map(TyKind
::Slice
)?
,
1198 ExprKind
::Tup(exprs
) => {
1199 let tys
= exprs
.iter().map(|expr
| expr
.to_ty()).collect
::<Option
<Vec
<_
>>>()?
;
1203 // If binary operator is `Add` and both `lhs` and `rhs` are trait bounds,
1204 // then type of result is trait object.
1205 // Otherwise we don't assume the result type.
1206 ExprKind
::Binary(binop
, lhs
, rhs
) if binop
.node
== BinOpKind
::Add
=> {
1207 if let (Some(lhs
), Some(rhs
)) = (lhs
.to_bound(), rhs
.to_bound()) {
1208 TyKind
::TraitObject(vec
![lhs
, rhs
], TraitObjectSyntax
::None
)
1214 ExprKind
::Underscore
=> TyKind
::Infer
,
1216 // This expression doesn't look like a type syntactically.
1220 Some(P(Ty { kind, id: self.id, span: self.span, tokens: None }
))
1223 pub fn precedence(&self) -> ExprPrecedence
{
1225 ExprKind
::Box(_
) => ExprPrecedence
::Box
,
1226 ExprKind
::Array(_
) => ExprPrecedence
::Array
,
1227 ExprKind
::ConstBlock(_
) => ExprPrecedence
::ConstBlock
,
1228 ExprKind
::Call(..) => ExprPrecedence
::Call
,
1229 ExprKind
::MethodCall(..) => ExprPrecedence
::MethodCall
,
1230 ExprKind
::Tup(_
) => ExprPrecedence
::Tup
,
1231 ExprKind
::Binary(op
, ..) => ExprPrecedence
::Binary(op
.node
),
1232 ExprKind
::Unary(..) => ExprPrecedence
::Unary
,
1233 ExprKind
::Lit(_
) => ExprPrecedence
::Lit
,
1234 ExprKind
::Type(..) | ExprKind
::Cast(..) => ExprPrecedence
::Cast
,
1235 ExprKind
::Let(..) => ExprPrecedence
::Let
,
1236 ExprKind
::If(..) => ExprPrecedence
::If
,
1237 ExprKind
::While(..) => ExprPrecedence
::While
,
1238 ExprKind
::ForLoop(..) => ExprPrecedence
::ForLoop
,
1239 ExprKind
::Loop(..) => ExprPrecedence
::Loop
,
1240 ExprKind
::Match(..) => ExprPrecedence
::Match
,
1241 ExprKind
::Closure(..) => ExprPrecedence
::Closure
,
1242 ExprKind
::Block(..) => ExprPrecedence
::Block
,
1243 ExprKind
::TryBlock(..) => ExprPrecedence
::TryBlock
,
1244 ExprKind
::Async(..) => ExprPrecedence
::Async
,
1245 ExprKind
::Await(..) => ExprPrecedence
::Await
,
1246 ExprKind
::Assign(..) => ExprPrecedence
::Assign
,
1247 ExprKind
::AssignOp(..) => ExprPrecedence
::AssignOp
,
1248 ExprKind
::Field(..) => ExprPrecedence
::Field
,
1249 ExprKind
::Index(..) => ExprPrecedence
::Index
,
1250 ExprKind
::Range(..) => ExprPrecedence
::Range
,
1251 ExprKind
::Underscore
=> ExprPrecedence
::Path
,
1252 ExprKind
::Path(..) => ExprPrecedence
::Path
,
1253 ExprKind
::AddrOf(..) => ExprPrecedence
::AddrOf
,
1254 ExprKind
::Break(..) => ExprPrecedence
::Break
,
1255 ExprKind
::Continue(..) => ExprPrecedence
::Continue
,
1256 ExprKind
::Ret(..) => ExprPrecedence
::Ret
,
1257 ExprKind
::InlineAsm(..) | ExprKind
::LlvmInlineAsm(..) => ExprPrecedence
::InlineAsm
,
1258 ExprKind
::MacCall(..) => ExprPrecedence
::Mac
,
1259 ExprKind
::Struct(..) => ExprPrecedence
::Struct
,
1260 ExprKind
::Repeat(..) => ExprPrecedence
::Repeat
,
1261 ExprKind
::Paren(..) => ExprPrecedence
::Paren
,
1262 ExprKind
::Try(..) => ExprPrecedence
::Try
,
1263 ExprKind
::Yield(..) => ExprPrecedence
::Yield
,
1264 ExprKind
::Err
=> ExprPrecedence
::Err
,
1269 /// Limit types of a range (inclusive or exclusive)
1270 #[derive(Copy, Clone, PartialEq, Encodable, Decodable, Debug)]
1271 pub enum RangeLimits
{
1272 /// Inclusive at the beginning, exclusive at the end
1274 /// Inclusive at the beginning and end
1278 #[derive(Clone, Encodable, Decodable, Debug)]
1279 pub enum StructRest
{
1284 /// No trailing `..` or expression.
1288 #[derive(Clone, Encodable, Decodable, Debug)]
1289 pub struct StructExpr
{
1290 pub qself
: Option
<QSelf
>,
1292 pub fields
: Vec
<ExprField
>,
1293 pub rest
: StructRest
,
1296 #[derive(Clone, Encodable, Decodable, Debug)]
1298 /// A `box x` expression.
1300 /// An array (`[a, b, c, d]`)
1301 Array(Vec
<P
<Expr
>>),
1302 /// Allow anonymous constants from an inline `const` block
1303 ConstBlock(AnonConst
),
1306 /// The first field resolves to the function itself,
1307 /// and the second field is the list of arguments.
1308 /// This also represents calling the constructor of
1309 /// tuple-like ADTs such as tuple structs and enum variants.
1310 Call(P
<Expr
>, Vec
<P
<Expr
>>),
1311 /// A method call (`x.foo::<'static, Bar, Baz>(a, b, c, d)`)
1313 /// The `PathSegment` represents the method name and its generic arguments
1314 /// (within the angle brackets).
1315 /// The first element of the vector of an `Expr` is the expression that evaluates
1316 /// to the object on which the method is being called on (the receiver),
1317 /// and the remaining elements are the rest of the arguments.
1318 /// Thus, `x.foo::<Bar, Baz>(a, b, c, d)` is represented as
1319 /// `ExprKind::MethodCall(PathSegment { foo, [Bar, Baz] }, [x, a, b, c, d])`.
1320 /// This `Span` is the span of the function, without the dot and receiver
1321 /// (e.g. `foo(a, b)` in `x.foo(a, b)`
1322 MethodCall(PathSegment
, Vec
<P
<Expr
>>, Span
),
1323 /// A tuple (e.g., `(a, b, c, d)`).
1325 /// A binary operation (e.g., `a + b`, `a * b`).
1326 Binary(BinOp
, P
<Expr
>, P
<Expr
>),
1327 /// A unary operation (e.g., `!x`, `*x`).
1328 Unary(UnOp
, P
<Expr
>),
1329 /// A literal (e.g., `1`, `"foo"`).
1331 /// A cast (e.g., `foo as f64`).
1332 Cast(P
<Expr
>, P
<Ty
>),
1333 /// A type ascription (e.g., `42: usize`).
1334 Type(P
<Expr
>, P
<Ty
>),
1335 /// A `let pat = expr` expression that is only semantically allowed in the condition
1336 /// of `if` / `while` expressions. (e.g., `if let 0 = x { .. }`).
1338 /// `Span` represents the whole `let pat = expr` statement.
1339 Let(P
<Pat
>, P
<Expr
>, Span
),
1340 /// An `if` block, with an optional `else` block.
1342 /// `if expr { block } else { expr }`
1343 If(P
<Expr
>, P
<Block
>, Option
<P
<Expr
>>),
1344 /// A while loop, with an optional label.
1346 /// `'label: while expr { block }`
1347 While(P
<Expr
>, P
<Block
>, Option
<Label
>),
1348 /// A `for` loop, with an optional label.
1350 /// `'label: for pat in expr { block }`
1352 /// This is desugared to a combination of `loop` and `match` expressions.
1353 ForLoop(P
<Pat
>, P
<Expr
>, P
<Block
>, Option
<Label
>),
1354 /// Conditionless loop (can be exited with `break`, `continue`, or `return`).
1356 /// `'label: loop { block }`
1357 Loop(P
<Block
>, Option
<Label
>),
1358 /// A `match` block.
1359 Match(P
<Expr
>, Vec
<Arm
>),
1360 /// A closure (e.g., `move |a, b, c| a + b + c`).
1362 /// The final span is the span of the argument block `|...|`.
1363 Closure(CaptureBy
, Async
, Movability
, P
<FnDecl
>, P
<Expr
>, Span
),
1364 /// A block (`'label: { ... }`).
1365 Block(P
<Block
>, Option
<Label
>),
1366 /// An async block (`async move { ... }`).
1368 /// The `NodeId` is the `NodeId` for the closure that results from
1369 /// desugaring an async block, just like the NodeId field in the
1370 /// `Async::Yes` variant. This is necessary in order to create a def for the
1371 /// closure which can be used as a parent of any child defs. Defs
1372 /// created during lowering cannot be made the parent of any other
1373 /// preexisting defs.
1374 Async(CaptureBy
, NodeId
, P
<Block
>),
1375 /// An await expression (`my_future.await`).
1378 /// A try block (`try { ... }`).
1381 /// An assignment (`a = foo()`).
1382 /// The `Span` argument is the span of the `=` token.
1383 Assign(P
<Expr
>, P
<Expr
>, Span
),
1384 /// An assignment with an operator.
1387 AssignOp(BinOp
, P
<Expr
>, P
<Expr
>),
1388 /// Access of a named (e.g., `obj.foo`) or unnamed (e.g., `obj.0`) struct field.
1389 Field(P
<Expr
>, Ident
),
1390 /// An indexing operation (e.g., `foo[2]`).
1391 Index(P
<Expr
>, P
<Expr
>),
1392 /// A range (e.g., `1..2`, `1..`, `..2`, `1..=2`, `..=2`; and `..` in destructuring assignment).
1393 Range(Option
<P
<Expr
>>, Option
<P
<Expr
>>, RangeLimits
),
1394 /// An underscore, used in destructuring assignment to ignore a value.
1397 /// Variable reference, possibly containing `::` and/or type
1398 /// parameters (e.g., `foo::bar::<baz>`).
1400 /// Optionally "qualified" (e.g., `<Vec<T> as SomeTrait>::SomeType`).
1401 Path(Option
<QSelf
>, Path
),
1403 /// A referencing operation (`&a`, `&mut a`, `&raw const a` or `&raw mut a`).
1404 AddrOf(BorrowKind
, Mutability
, P
<Expr
>),
1405 /// A `break`, with an optional label to break, and an optional expression.
1406 Break(Option
<Label
>, Option
<P
<Expr
>>),
1407 /// A `continue`, with an optional label.
1408 Continue(Option
<Label
>),
1409 /// A `return`, with an optional value to be returned.
1410 Ret(Option
<P
<Expr
>>),
1412 /// Output of the `asm!()` macro.
1413 InlineAsm(P
<InlineAsm
>),
1414 /// Output of the `llvm_asm!()` macro.
1415 LlvmInlineAsm(P
<LlvmInlineAsm
>),
1417 /// A macro invocation; pre-expansion.
1420 /// A struct literal expression.
1422 /// E.g., `Foo {x: 1, y: 2}`, or `Foo {x: 1, .. rest}`.
1423 Struct(P
<StructExpr
>),
1425 /// An array literal constructed from one repeated element.
1427 /// E.g., `[1; 5]`. The expression is the element to be
1428 /// repeated; the constant is the number of times to repeat it.
1429 Repeat(P
<Expr
>, AnonConst
),
1431 /// No-op: used solely so we can pretty-print faithfully.
1434 /// A try expression (`expr?`).
1437 /// A `yield`, with an optional value to be yielded.
1438 Yield(Option
<P
<Expr
>>),
1440 /// Placeholder for an expression that wasn't syntactically well formed in some way.
1444 /// The explicit `Self` type in a "qualified path". The actual
1445 /// path, including the trait and the associated item, is stored
1446 /// separately. `position` represents the index of the associated
1447 /// item qualified with this `Self` type.
1449 /// ```ignore (only-for-syntax-highlight)
1450 /// <Vec<T> as a::b::Trait>::AssociatedItem
1451 /// ^~~~~ ~~~~~~~~~~~~~~^
1454 /// <Vec<T>>::AssociatedItem
1458 #[derive(Clone, Encodable, Decodable, Debug)]
1462 /// The span of `a::b::Trait` in a path like `<Vec<T> as
1463 /// a::b::Trait>::AssociatedItem`; in the case where `position ==
1464 /// 0`, this is an empty span.
1465 pub path_span
: Span
,
1466 pub position
: usize,
1469 /// A capture clause used in closures and `async` blocks.
1470 #[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)]
1471 pub enum CaptureBy
{
1472 /// `move |x| y + x`.
1474 /// `move` keyword was not specified.
1478 /// The movability of a generator / closure literal:
1479 /// whether a generator contains self-references, causing it to be `!Unpin`.
1480 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Encodable, Decodable, Debug, Copy)]
1481 #[derive(HashStable_Generic)]
1482 pub enum Movability
{
1483 /// May contain self-references, `!Unpin`.
1485 /// Must not contain self-references, `Unpin`.
1489 /// Represents a macro invocation. The `path` indicates which macro
1490 /// is being invoked, and the `args` are arguments passed to it.
1491 #[derive(Clone, Encodable, Decodable, Debug)]
1492 pub struct MacCall
{
1494 pub args
: P
<MacArgs
>,
1495 pub prior_type_ascription
: Option
<(Span
, bool
)>,
1499 pub fn span(&self) -> Span
{
1500 self.path
.span
.to(self.args
.span().unwrap_or(self.path
.span
))
1504 /// Arguments passed to an attribute or a function-like macro.
1505 #[derive(Clone, Encodable, Decodable, Debug, HashStable_Generic)]
1507 /// No arguments - `#[attr]`.
1509 /// Delimited arguments - `#[attr()/[]/{}]` or `mac!()/[]/{}`.
1510 Delimited(DelimSpan
, MacDelimiter
, TokenStream
),
1511 /// Arguments of a key-value attribute - `#[attr = "value"]`.
1513 /// Span of the `=` token.
1515 /// "value" as a nonterminal token.
1521 pub fn delim(&self) -> DelimToken
{
1523 MacArgs
::Delimited(_
, delim
, _
) => delim
.to_token(),
1524 MacArgs
::Empty
| MacArgs
::Eq(..) => token
::NoDelim
,
1528 pub fn span(&self) -> Option
<Span
> {
1530 MacArgs
::Empty
=> None
,
1531 MacArgs
::Delimited(dspan
, ..) => Some(dspan
.entire()),
1532 MacArgs
::Eq(eq_span
, token
) => Some(eq_span
.to(token
.span
)),
1536 /// Tokens inside the delimiters or after `=`.
1537 /// Proc macros see these tokens, for example.
1538 pub fn inner_tokens(&self) -> TokenStream
{
1540 MacArgs
::Empty
=> TokenStream
::default(),
1541 MacArgs
::Delimited(.., tokens
) => tokens
.clone(),
1542 MacArgs
::Eq(.., token
) => TokenTree
::Token(token
.clone()).into(),
1546 /// Whether a macro with these arguments needs a semicolon
1547 /// when used as a standalone item or statement.
1548 pub fn need_semicolon(&self) -> bool
{
1549 !matches
!(self, MacArgs
::Delimited(_
, MacDelimiter
::Brace
, _
))
1553 #[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
1554 pub enum MacDelimiter
{
1561 pub fn to_token(self) -> DelimToken
{
1563 MacDelimiter
::Parenthesis
=> DelimToken
::Paren
,
1564 MacDelimiter
::Bracket
=> DelimToken
::Bracket
,
1565 MacDelimiter
::Brace
=> DelimToken
::Brace
,
1569 pub fn from_token(delim
: DelimToken
) -> Option
<MacDelimiter
> {
1571 token
::Paren
=> Some(MacDelimiter
::Parenthesis
),
1572 token
::Bracket
=> Some(MacDelimiter
::Bracket
),
1573 token
::Brace
=> Some(MacDelimiter
::Brace
),
1574 token
::NoDelim
=> None
,
1579 /// Represents a macro definition.
1580 #[derive(Clone, Encodable, Decodable, Debug, HashStable_Generic)]
1581 pub struct MacroDef
{
1582 pub body
: P
<MacArgs
>,
1583 /// `true` if macro was defined with `macro_rules`.
1584 pub macro_rules
: bool
,
1587 #[derive(Clone, Encodable, Decodable, Debug, Copy, Hash, Eq, PartialEq)]
1588 #[derive(HashStable_Generic)]
1590 /// A regular string, like `"foo"`.
1592 /// A raw string, like `r##"foo"##`.
1594 /// The value is the number of `#` symbols used.
1599 #[derive(Clone, Encodable, Decodable, Debug, HashStable_Generic)]
1601 /// The original literal token as written in source code.
1602 pub token
: token
::Lit
,
1603 /// The "semantic" representation of the literal lowered from the original tokens.
1604 /// Strings are unescaped, hexadecimal forms are eliminated, etc.
1605 /// FIXME: Remove this and only create the semantic representation during lowering to HIR.
1610 /// Same as `Lit`, but restricted to string literals.
1611 #[derive(Clone, Copy, Encodable, Decodable, Debug)]
1613 /// The original literal token as written in source code.
1614 pub style
: StrStyle
,
1616 pub suffix
: Option
<Symbol
>,
1618 /// The unescaped "semantic" representation of the literal lowered from the original token.
1619 /// FIXME: Remove this and only create the semantic representation during lowering to HIR.
1620 pub symbol_unescaped
: Symbol
,
1624 pub fn as_lit(&self) -> Lit
{
1625 let token_kind
= match self.style
{
1626 StrStyle
::Cooked
=> token
::Str
,
1627 StrStyle
::Raw(n
) => token
::StrRaw(n
),
1630 token
: token
::Lit
::new(token_kind
, self.symbol
, self.suffix
),
1632 kind
: LitKind
::Str(self.symbol_unescaped
, self.style
),
1637 /// Type of the integer literal based on provided suffix.
1638 #[derive(Clone, Copy, Encodable, Decodable, Debug, Hash, Eq, PartialEq)]
1639 #[derive(HashStable_Generic)]
1640 pub enum LitIntType
{
1649 /// Type of the float literal based on provided suffix.
1650 #[derive(Clone, Copy, Encodable, Decodable, Debug, Hash, Eq, PartialEq)]
1651 #[derive(HashStable_Generic)]
1652 pub enum LitFloatType
{
1653 /// A float literal with a suffix (`1f32` or `1E10f32`).
1655 /// A float literal without a suffix (`1.0 or 1.0E10`).
1661 /// E.g., `"foo"`, `42`, `12.34`, or `bool`.
1662 #[derive(Clone, Encodable, Decodable, Debug, Hash, Eq, PartialEq, HashStable_Generic)]
1664 /// A string literal (`"foo"`).
1665 Str(Symbol
, StrStyle
),
1666 /// A byte string (`b"foo"`).
1668 /// A byte char (`b'f'`).
1670 /// A character literal (`'a'`).
1672 /// An integer literal (`1`).
1673 Int(u128
, LitIntType
),
1674 /// A float literal (`1f64` or `1E10f64`).
1675 Float(Symbol
, LitFloatType
),
1676 /// A boolean literal.
1678 /// Placeholder for a literal that wasn't well-formed in some way.
1683 /// Returns `true` if this literal is a string.
1684 pub fn is_str(&self) -> bool
{
1685 matches
!(self, LitKind
::Str(..))
1688 /// Returns `true` if this literal is byte literal string.
1689 pub fn is_bytestr(&self) -> bool
{
1690 matches
!(self, LitKind
::ByteStr(_
))
1693 /// Returns `true` if this is a numeric literal.
1694 pub fn is_numeric(&self) -> bool
{
1695 matches
!(self, LitKind
::Int(..) | LitKind
::Float(..))
1698 /// Returns `true` if this literal has no suffix.
1699 /// Note: this will return true for literals with prefixes such as raw strings and byte strings.
1700 pub fn is_unsuffixed(&self) -> bool
{
1704 /// Returns `true` if this literal has a suffix.
1705 pub fn is_suffixed(&self) -> bool
{
1707 // suffixed variants
1708 LitKind
::Int(_
, LitIntType
::Signed(..) | LitIntType
::Unsigned(..))
1709 | LitKind
::Float(_
, LitFloatType
::Suffixed(..)) => true,
1710 // unsuffixed variants
1712 | LitKind
::ByteStr(..)
1715 | LitKind
::Int(_
, LitIntType
::Unsuffixed
)
1716 | LitKind
::Float(_
, LitFloatType
::Unsuffixed
)
1718 | LitKind
::Err(..) => false,
1723 // N.B., If you change this, you'll probably want to change the corresponding
1724 // type structure in `middle/ty.rs` as well.
1725 #[derive(Clone, Encodable, Decodable, Debug)]
1728 pub mutbl
: Mutability
,
1731 /// Represents a function's signature in a trait declaration,
1732 /// trait implementation, or free function.
1733 #[derive(Clone, Encodable, Decodable, Debug)]
1735 pub header
: FnHeader
,
1736 pub decl
: P
<FnDecl
>,
1740 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
1741 #[derive(Encodable, Decodable, HashStable_Generic)]
1748 pub fn name_str(self) -> &'
static str {
1750 FloatTy
::F32
=> "f32",
1751 FloatTy
::F64
=> "f64",
1755 pub fn name(self) -> Symbol
{
1757 FloatTy
::F32
=> sym
::f32,
1758 FloatTy
::F64
=> sym
::f64,
1763 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
1764 #[derive(Encodable, Decodable, HashStable_Generic)]
1775 pub fn name_str(&self) -> &'
static str {
1777 IntTy
::Isize
=> "isize",
1779 IntTy
::I16
=> "i16",
1780 IntTy
::I32
=> "i32",
1781 IntTy
::I64
=> "i64",
1782 IntTy
::I128
=> "i128",
1786 pub fn name(&self) -> Symbol
{
1788 IntTy
::Isize
=> sym
::isize,
1789 IntTy
::I8
=> sym
::i8,
1790 IntTy
::I16
=> sym
::i16,
1791 IntTy
::I32
=> sym
::i32,
1792 IntTy
::I64
=> sym
::i64,
1793 IntTy
::I128
=> sym
::i128
,
1798 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Copy, Debug)]
1799 #[derive(Encodable, Decodable, HashStable_Generic)]
1810 pub fn name_str(&self) -> &'
static str {
1812 UintTy
::Usize
=> "usize",
1814 UintTy
::U16
=> "u16",
1815 UintTy
::U32
=> "u32",
1816 UintTy
::U64
=> "u64",
1817 UintTy
::U128
=> "u128",
1821 pub fn name(&self) -> Symbol
{
1823 UintTy
::Usize
=> sym
::usize,
1824 UintTy
::U8
=> sym
::u8,
1825 UintTy
::U16
=> sym
::u16,
1826 UintTy
::U32
=> sym
::u32,
1827 UintTy
::U64
=> sym
::u64,
1828 UintTy
::U128
=> sym
::u128
,
1833 /// A constraint on an associated type (e.g., `A = Bar` in `Foo<A = Bar>` or
1834 /// `A: TraitA + TraitB` in `Foo<A: TraitA + TraitB>`).
1835 #[derive(Clone, Encodable, Decodable, Debug)]
1836 pub struct AssocTyConstraint
{
1839 pub gen_args
: Option
<GenericArgs
>,
1840 pub kind
: AssocTyConstraintKind
,
1844 /// The kinds of an `AssocTyConstraint`.
1845 #[derive(Clone, Encodable, Decodable, Debug)]
1846 pub enum AssocTyConstraintKind
{
1847 /// E.g., `A = Bar` in `Foo<A = Bar>`.
1848 Equality { ty: P<Ty> }
,
1849 /// E.g. `A: TraitA + TraitB` in `Foo<A: TraitA + TraitB>`.
1850 Bound { bounds: GenericBounds }
,
1853 #[derive(Encodable, Decodable, Debug)]
1858 pub tokens
: Option
<LazyTokenStream
>,
1862 fn clone(&self) -> Self {
1863 ensure_sufficient_stack(|| Self {
1865 kind
: self.kind
.clone(),
1867 tokens
: self.tokens
.clone(),
1873 pub fn peel_refs(&self) -> &Self {
1874 let mut final_ty
= self;
1875 while let TyKind
::Rptr(_
, MutTy { ty, .. }
) = &final_ty
.kind
{
1882 #[derive(Clone, Encodable, Decodable, Debug)]
1883 pub struct BareFnTy
{
1884 pub unsafety
: Unsafe
,
1886 pub generic_params
: Vec
<GenericParam
>,
1887 pub decl
: P
<FnDecl
>,
1890 /// The various kinds of type recognized by the compiler.
1891 #[derive(Clone, Encodable, Decodable, Debug)]
1893 /// A variable-length slice (`[T]`).
1895 /// A fixed length array (`[T; n]`).
1896 Array(P
<Ty
>, AnonConst
),
1897 /// A raw pointer (`*const T` or `*mut T`).
1899 /// A reference (`&'a T` or `&'a mut T`).
1900 Rptr(Option
<Lifetime
>, MutTy
),
1901 /// A bare function (e.g., `fn(usize) -> bool`).
1902 BareFn(P
<BareFnTy
>),
1903 /// The never type (`!`).
1905 /// A tuple (`(A, B, C, D,...)`).
1907 /// A path (`module::module::...::Type`), optionally
1908 /// "qualified", e.g., `<Vec<T> as SomeTrait>::SomeType`.
1910 /// Type parameters are stored in the `Path` itself.
1911 Path(Option
<QSelf
>, Path
),
1912 /// A trait object type `Bound1 + Bound2 + Bound3`
1913 /// where `Bound` is a trait or a lifetime.
1914 TraitObject(GenericBounds
, TraitObjectSyntax
),
1915 /// An `impl Bound1 + Bound2 + Bound3` type
1916 /// where `Bound` is a trait or a lifetime.
1918 /// The `NodeId` exists to prevent lowering from having to
1919 /// generate `NodeId`s on the fly, which would complicate
1920 /// the generation of opaque `type Foo = impl Trait` items significantly.
1921 ImplTrait(NodeId
, GenericBounds
),
1922 /// No-op; kept solely so that we can pretty-print faithfully.
1926 /// This means the type should be inferred instead of it having been
1927 /// specified. This can appear anywhere in a type.
1929 /// Inferred type of a `self` or `&self` argument in a method.
1931 /// A macro in the type position.
1933 /// Placeholder for a kind that has failed to be defined.
1935 /// Placeholder for a `va_list`.
1940 pub fn is_implicit_self(&self) -> bool
{
1941 matches
!(self, TyKind
::ImplicitSelf
)
1944 pub fn is_unit(&self) -> bool
{
1945 matches
!(self, TyKind
::Tup(tys
) if tys
.is_empty())
1949 /// Syntax used to declare a trait object.
1950 #[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)]
1951 pub enum TraitObjectSyntax
{
1956 /// Inline assembly operand explicit register or register class.
1958 /// E.g., `"eax"` as in `asm!("mov eax, 2", out("eax") result)`.
1959 #[derive(Clone, Copy, Encodable, Decodable, Debug)]
1960 pub enum InlineAsmRegOrRegClass
{
1965 bitflags
::bitflags
! {
1966 #[derive(Encodable, Decodable, HashStable_Generic)]
1967 pub struct InlineAsmOptions
: u8 {
1968 const PURE
= 1 << 0;
1969 const NOMEM
= 1 << 1;
1970 const READONLY
= 1 << 2;
1971 const PRESERVES_FLAGS
= 1 << 3;
1972 const NORETURN
= 1 << 4;
1973 const NOSTACK
= 1 << 5;
1974 const ATT_SYNTAX
= 1 << 6;
1979 #[derive(Clone, PartialEq, PartialOrd, Encodable, Decodable, Debug, Hash, HashStable_Generic)]
1980 pub enum InlineAsmTemplatePiece
{
1982 Placeholder { operand_idx: usize, modifier: Option<char>, span: Span }
,
1985 impl fmt
::Display
for InlineAsmTemplatePiece
{
1986 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
1988 Self::String(s
) => {
1989 for c
in s
.chars() {
1991 '
{'
=> f
.write_str("{{")?
,
1992 '
}'
=> f
.write_str("}}")?
,
1998 Self::Placeholder { operand_idx, modifier: Some(modifier), .. }
=> {
1999 write
!(f
, "{{{}:{}}}", operand_idx
, modifier
)
2001 Self::Placeholder { operand_idx, modifier: None, .. }
=> {
2002 write
!(f
, "{{{}}}", operand_idx
)
2008 impl InlineAsmTemplatePiece
{
2009 /// Rebuilds the asm template string from its pieces.
2010 pub fn to_string(s
: &[Self]) -> String
{
2012 let mut out
= String
::new();
2014 let _
= write
!(out
, "{}", p
);
2020 /// Inline assembly operand.
2022 /// E.g., `out("eax") result` as in `asm!("mov eax, 2", out("eax") result)`.
2023 #[derive(Clone, Encodable, Decodable, Debug)]
2024 pub enum InlineAsmOperand
{
2026 reg
: InlineAsmRegOrRegClass
,
2030 reg
: InlineAsmRegOrRegClass
,
2032 expr
: Option
<P
<Expr
>>,
2035 reg
: InlineAsmRegOrRegClass
,
2040 reg
: InlineAsmRegOrRegClass
,
2043 out_expr
: Option
<P
<Expr
>>,
2046 anon_const
: AnonConst
,
2053 /// Inline assembly.
2055 /// E.g., `asm!("NOP");`.
2056 #[derive(Clone, Encodable, Decodable, Debug)]
2057 pub struct InlineAsm
{
2058 pub template
: Vec
<InlineAsmTemplatePiece
>,
2059 pub template_strs
: Box
<[(Symbol
, Option
<Symbol
>, Span
)]>,
2060 pub operands
: Vec
<(InlineAsmOperand
, Span
)>,
2061 pub clobber_abi
: Option
<(Symbol
, Span
)>,
2062 pub options
: InlineAsmOptions
,
2063 pub line_spans
: Vec
<Span
>,
2066 /// Inline assembly dialect.
2068 /// E.g., `"intel"` as in `llvm_asm!("mov eax, 2" : "={eax}"(result) : : : "intel")`.
2069 #[derive(Clone, PartialEq, Encodable, Decodable, Debug, Copy, Hash, HashStable_Generic)]
2070 pub enum LlvmAsmDialect
{
2075 /// LLVM-style inline assembly.
2077 /// E.g., `"={eax}"(result)` as in `llvm_asm!("mov eax, 2" : "={eax}"(result) : : : "intel")`.
2078 #[derive(Clone, Encodable, Decodable, Debug)]
2079 pub struct LlvmInlineAsmOutput
{
2080 pub constraint
: Symbol
,
2083 pub is_indirect
: bool
,
2086 /// LLVM-style inline assembly.
2088 /// E.g., `llvm_asm!("NOP");`.
2089 #[derive(Clone, Encodable, Decodable, Debug)]
2090 pub struct LlvmInlineAsm
{
2092 pub asm_str_style
: StrStyle
,
2093 pub outputs
: Vec
<LlvmInlineAsmOutput
>,
2094 pub inputs
: Vec
<(Symbol
, P
<Expr
>)>,
2095 pub clobbers
: Vec
<Symbol
>,
2097 pub alignstack
: bool
,
2098 pub dialect
: LlvmAsmDialect
,
2101 /// A parameter in a function header.
2103 /// E.g., `bar: usize` as in `fn foo(bar: usize)`.
2104 #[derive(Clone, Encodable, Decodable, Debug)]
2111 pub is_placeholder
: bool
,
2114 /// Alternative representation for `Arg`s describing `self` parameter of methods.
2116 /// E.g., `&mut self` as in `fn foo(&mut self)`.
2117 #[derive(Clone, Encodable, Decodable, Debug)]
2119 /// `self`, `mut self`
2121 /// `&'lt self`, `&'lt mut self`
2122 Region(Option
<Lifetime
>, Mutability
),
2123 /// `self: TYPE`, `mut self: TYPE`
2124 Explicit(P
<Ty
>, Mutability
),
2127 pub type ExplicitSelf
= Spanned
<SelfKind
>;
2130 /// Attempts to cast parameter to `ExplicitSelf`.
2131 pub fn to_self(&self) -> Option
<ExplicitSelf
> {
2132 if let PatKind
::Ident(BindingMode
::ByValue(mutbl
), ident
, _
) = self.pat
.kind
{
2133 if ident
.name
== kw
::SelfLower
{
2134 return match self.ty
.kind
{
2135 TyKind
::ImplicitSelf
=> Some(respan(self.pat
.span
, SelfKind
::Value(mutbl
))),
2136 TyKind
::Rptr(lt
, MutTy { ref ty, mutbl }
) if ty
.kind
.is_implicit_self() => {
2137 Some(respan(self.pat
.span
, SelfKind
::Region(lt
, mutbl
)))
2140 self.pat
.span
.to(self.ty
.span
),
2141 SelfKind
::Explicit(self.ty
.clone(), mutbl
),
2149 /// Returns `true` if parameter is `self`.
2150 pub fn is_self(&self) -> bool
{
2151 if let PatKind
::Ident(_
, ident
, _
) = self.pat
.kind
{
2152 ident
.name
== kw
::SelfLower
2158 /// Builds a `Param` object from `ExplicitSelf`.
2159 pub fn from_self(attrs
: AttrVec
, eself
: ExplicitSelf
, eself_ident
: Ident
) -> Param
{
2160 let span
= eself
.span
.to(eself_ident
.span
);
2161 let infer_ty
= P(Ty { id: DUMMY_NODE_ID, kind: TyKind::ImplicitSelf, span, tokens: None }
);
2162 let param
= |mutbl
, ty
| Param
{
2166 kind
: PatKind
::Ident(BindingMode
::ByValue(mutbl
), eself_ident
, None
),
2173 is_placeholder
: false,
2176 SelfKind
::Explicit(ty
, mutbl
) => param(mutbl
, ty
),
2177 SelfKind
::Value(mutbl
) => param(mutbl
, infer_ty
),
2178 SelfKind
::Region(lt
, mutbl
) => param(
2182 kind
: TyKind
::Rptr(lt
, MutTy { ty: infer_ty, mutbl }
),
2191 /// A signature (not the body) of a function declaration.
2193 /// E.g., `fn foo(bar: baz)`.
2195 /// Please note that it's different from `FnHeader` structure
2196 /// which contains metadata about function safety, asyncness, constness and ABI.
2197 #[derive(Clone, Encodable, Decodable, Debug)]
2199 pub inputs
: Vec
<Param
>,
2200 pub output
: FnRetTy
,
2204 pub fn has_self(&self) -> bool
{
2205 self.inputs
.get(0).map_or(false, Param
::is_self
)
2207 pub fn c_variadic(&self) -> bool
{
2208 self.inputs
.last().map_or(false, |arg
| matches
!(arg
.ty
.kind
, TyKind
::CVarArgs
))
2212 /// Is the trait definition an auto trait?
2213 #[derive(Copy, Clone, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)]
2219 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Encodable, Decodable, Debug)]
2220 #[derive(HashStable_Generic)]
2226 #[derive(Copy, Clone, Encodable, Decodable, Debug)]
2228 Yes { span: Span, closure_id: NodeId, return_impl_trait_id: NodeId }
,
2233 pub fn is_async(self) -> bool
{
2234 matches
!(self, Async
::Yes { .. }
)
2237 /// In this case this is an `async` return, the `NodeId` for the generated `impl Trait` item.
2238 pub fn opt_return_id(self) -> Option
<NodeId
> {
2240 Async
::Yes { return_impl_trait_id, .. }
=> Some(return_impl_trait_id
),
2246 #[derive(Copy, Clone, PartialEq, Eq, Hash, Encodable, Decodable, Debug)]
2247 #[derive(HashStable_Generic)]
2253 /// Item defaultness.
2254 /// For details see the [RFC #2532](https://github.com/rust-lang/rfcs/pull/2532).
2255 #[derive(Copy, Clone, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)]
2256 pub enum Defaultness
{
2261 #[derive(Copy, Clone, PartialEq, Encodable, Decodable, HashStable_Generic)]
2262 pub enum ImplPolarity
{
2263 /// `impl Trait for Type`
2265 /// `impl !Trait for Type`
2269 impl fmt
::Debug
for ImplPolarity
{
2270 fn fmt(&self, f
: &mut fmt
::Formatter
<'_
>) -> fmt
::Result
{
2272 ImplPolarity
::Positive
=> "positive".fmt(f
),
2273 ImplPolarity
::Negative(_
) => "negative".fmt(f
),
2278 #[derive(Clone, Encodable, Decodable, Debug)]
2280 /// Returns type is not specified.
2282 /// Functions default to `()` and closures default to inference.
2283 /// Span points to where return type would be inserted.
2285 /// Everything else.
2290 pub fn span(&self) -> Span
{
2292 FnRetTy
::Default(span
) => span
,
2293 FnRetTy
::Ty(ref ty
) => ty
.span
,
2298 #[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug)]
2304 /// Module item kind.
2305 #[derive(Clone, Encodable, Decodable, Debug)]
2307 /// Module with inlined definition `mod foo { ... }`,
2308 /// or with definition outlined to a separate file `mod foo;` and already loaded from it.
2309 /// The inner span is from the first token past `{` to the last token until `}`,
2310 /// or from the first to the last token in the loaded file.
2311 Loaded(Vec
<P
<Item
>>, Inline
, Span
),
2312 /// Module with definition outlined to a separate file `mod foo;` but not yet loaded from it.
2316 /// Foreign module declaration.
2318 /// E.g., `extern { .. }` or `extern "C" { .. }`.
2319 #[derive(Clone, Encodable, Decodable, Debug)]
2320 pub struct ForeignMod
{
2321 /// `unsafe` keyword accepted syntactically for macro DSLs, but not
2322 /// semantically by Rust.
2323 pub unsafety
: Unsafe
,
2324 pub abi
: Option
<StrLit
>,
2325 pub items
: Vec
<P
<ForeignItem
>>,
2328 #[derive(Clone, Encodable, Decodable, Debug)]
2329 pub struct EnumDef
{
2330 pub variants
: Vec
<Variant
>,
2333 #[derive(Clone, Encodable, Decodable, Debug)]
2334 pub struct Variant
{
2335 /// Attributes of the variant.
2337 /// Id of the variant (not the constructor, see `VariantData::ctor_id()`).
2341 /// The visibility of the variant. Syntactically accepted but not semantically.
2342 pub vis
: Visibility
,
2343 /// Name of the variant.
2346 /// Fields and constructor id of the variant.
2347 pub data
: VariantData
,
2348 /// Explicit discriminant, e.g., `Foo = 1`.
2349 pub disr_expr
: Option
<AnonConst
>,
2350 /// Is a macro placeholder
2351 pub is_placeholder
: bool
,
2354 /// Part of `use` item to the right of its prefix.
2355 #[derive(Clone, Encodable, Decodable, Debug)]
2356 pub enum UseTreeKind
{
2357 /// `use prefix` or `use prefix as rename`
2359 /// The extra `NodeId`s are for HIR lowering, when additional statements are created for each
2361 Simple(Option
<Ident
>, NodeId
, NodeId
),
2362 /// `use prefix::{...}`
2363 Nested(Vec
<(UseTree
, NodeId
)>),
2368 /// A tree of paths sharing common prefixes.
2369 /// Used in `use` items both at top-level and inside of braces in import groups.
2370 #[derive(Clone, Encodable, Decodable, Debug)]
2371 pub struct UseTree
{
2373 pub kind
: UseTreeKind
,
2378 pub fn ident(&self) -> Ident
{
2380 UseTreeKind
::Simple(Some(rename
), ..) => rename
,
2381 UseTreeKind
::Simple(None
, ..) => {
2382 self.prefix
.segments
.last().expect("empty prefix in a simple import").ident
2384 _
=> panic
!("`UseTree::ident` can only be used on a simple import"),
2389 /// Distinguishes between `Attribute`s that decorate items and Attributes that
2390 /// are contained as statements within items. These two cases need to be
2391 /// distinguished for pretty-printing.
2392 #[derive(Clone, PartialEq, Encodable, Decodable, Debug, Copy, HashStable_Generic)]
2393 pub enum AttrStyle
{
2398 rustc_index
::newtype_index
! {
2401 DEBUG_FORMAT
= "AttrId({})"
2405 impl<S
: Encoder
> rustc_serialize
::Encodable
<S
> for AttrId
{
2406 fn encode(&self, s
: &mut S
) -> Result
<(), S
::Error
> {
2411 impl<D
: Decoder
> rustc_serialize
::Decodable
<D
> for AttrId
{
2412 fn decode(d
: &mut D
) -> Result
<AttrId
, D
::Error
> {
2413 d
.read_nil().map(|_
| crate::attr
::mk_attr_id())
2417 #[derive(Clone, Encodable, Decodable, Debug, HashStable_Generic)]
2418 pub struct AttrItem
{
2421 pub tokens
: Option
<LazyTokenStream
>,
2424 /// A list of attributes.
2425 pub type AttrVec
= ThinVec
<Attribute
>;
2427 /// Metadata associated with an item.
2428 #[derive(Clone, Encodable, Decodable, Debug)]
2429 pub struct Attribute
{
2432 /// Denotes if the attribute decorates the following construct (outer)
2433 /// or the construct this attribute is contained within (inner).
2434 pub style
: AttrStyle
,
2438 #[derive(Clone, Encodable, Decodable, Debug)]
2440 /// A normal attribute.
2441 Normal(AttrItem
, Option
<LazyTokenStream
>),
2443 /// A doc comment (e.g. `/// ...`, `//! ...`, `/** ... */`, `/*! ... */`).
2444 /// Doc attributes (e.g. `#[doc="..."]`) are represented with the `Normal`
2445 /// variant (which is much less compact and thus more expensive).
2446 DocComment(CommentKind
, Symbol
),
2449 /// `TraitRef`s appear in impls.
2451 /// Resolution maps each `TraitRef`'s `ref_id` to its defining trait; that's all
2452 /// that the `ref_id` is for. The `impl_id` maps to the "self type" of this impl.
2453 /// If this impl is an `ItemKind::Impl`, the `impl_id` is redundant (it could be the
2454 /// same as the impl's `NodeId`).
2455 #[derive(Clone, Encodable, Decodable, Debug)]
2456 pub struct TraitRef
{
2461 #[derive(Clone, Encodable, Decodable, Debug)]
2462 pub struct PolyTraitRef
{
2463 /// The `'a` in `<'a> Foo<&'a T>`.
2464 pub bound_generic_params
: Vec
<GenericParam
>,
2466 /// The `Foo<&'a T>` in `<'a> Foo<&'a T>`.
2467 pub trait_ref
: TraitRef
,
2473 pub fn new(generic_params
: Vec
<GenericParam
>, path
: Path
, span
: Span
) -> Self {
2475 bound_generic_params
: generic_params
,
2476 trait_ref
: TraitRef { path, ref_id: DUMMY_NODE_ID }
,
2482 #[derive(Copy, Clone, Encodable, Decodable, Debug, HashStable_Generic)]
2483 pub enum CrateSugar
{
2484 /// Source is `pub(crate)`.
2487 /// Source is (just) `crate`.
2491 #[derive(Clone, Encodable, Decodable, Debug)]
2492 pub struct Visibility
{
2493 pub kind
: VisibilityKind
,
2495 pub tokens
: Option
<LazyTokenStream
>,
2498 #[derive(Clone, Encodable, Decodable, Debug)]
2499 pub enum VisibilityKind
{
2502 Restricted { path: P<Path>, id: NodeId }
,
2506 impl VisibilityKind
{
2507 pub fn is_pub(&self) -> bool
{
2508 matches
!(self, VisibilityKind
::Public
)
2512 /// Field definition in a struct, variant or union.
2514 /// E.g., `bar: usize` as in `struct Foo { bar: usize }`.
2515 #[derive(Clone, Encodable, Decodable, Debug)]
2516 pub struct FieldDef
{
2520 pub vis
: Visibility
,
2521 pub ident
: Option
<Ident
>,
2524 pub is_placeholder
: bool
,
2527 /// Fields and constructor ids of enum variants and structs.
2528 #[derive(Clone, Encodable, Decodable, Debug)]
2529 pub enum VariantData
{
2532 /// E.g., `Bar { .. }` as in `enum Foo { Bar { .. } }`.
2533 Struct(Vec
<FieldDef
>, bool
),
2536 /// E.g., `Bar(..)` as in `enum Foo { Bar(..) }`.
2537 Tuple(Vec
<FieldDef
>, NodeId
),
2540 /// E.g., `Bar = ..` as in `enum Foo { Bar = .. }`.
2545 /// Return the fields of this variant.
2546 pub fn fields(&self) -> &[FieldDef
] {
2548 VariantData
::Struct(ref fields
, ..) | VariantData
::Tuple(ref fields
, _
) => fields
,
2553 /// Return the `NodeId` of this variant's constructor, if it has one.
2554 pub fn ctor_id(&self) -> Option
<NodeId
> {
2556 VariantData
::Struct(..) => None
,
2557 VariantData
::Tuple(_
, id
) | VariantData
::Unit(id
) => Some(id
),
2562 /// An item definition.
2563 #[derive(Clone, Encodable, Decodable, Debug)]
2564 pub struct Item
<K
= ItemKind
> {
2565 pub attrs
: Vec
<Attribute
>,
2568 pub vis
: Visibility
,
2569 /// The name of the item.
2570 /// It might be a dummy name in case of anonymous items.
2575 /// Original tokens this item was parsed from. This isn't necessarily
2576 /// available for all items, although over time more and more items should
2577 /// have this be `Some`. Right now this is primarily used for procedural
2578 /// macros, notably custom attributes.
2580 /// Note that the tokens here do not include the outer attributes, but will
2581 /// include inner attributes.
2582 pub tokens
: Option
<LazyTokenStream
>,
2586 /// Return the span that encompasses the attributes.
2587 pub fn span_with_attributes(&self) -> Span
{
2588 self.attrs
.iter().fold(self.span
, |acc
, attr
| acc
.to(attr
.span
))
2592 impl<K
: Into
<ItemKind
>> Item
<K
> {
2593 pub fn into_item(self) -> Item
{
2594 let Item { attrs, id, span, vis, ident, kind, tokens }
= self;
2595 Item { attrs, id, span, vis, ident, kind: kind.into(), tokens }
2599 /// `extern` qualifier on a function item or function type.
2600 #[derive(Clone, Copy, Encodable, Decodable, Debug)]
2608 pub fn from_abi(abi
: Option
<StrLit
>) -> Extern
{
2609 abi
.map_or(Extern
::Implicit
, Extern
::Explicit
)
2613 /// A function header.
2615 /// All the information between the visibility and the name of the function is
2616 /// included in this struct (e.g., `async unsafe fn` or `const extern "C" fn`).
2617 #[derive(Clone, Copy, Encodable, Decodable, Debug)]
2618 pub struct FnHeader
{
2619 pub unsafety
: Unsafe
,
2620 pub asyncness
: Async
,
2621 pub constness
: Const
,
2626 /// Does this function header have any qualifiers or is it empty?
2627 pub fn has_qualifiers(&self) -> bool
{
2628 let Self { unsafety, asyncness, constness, ext }
= self;
2629 matches
!(unsafety
, Unsafe
::Yes(_
))
2630 || asyncness
.is_async()
2631 || matches
!(constness
, Const
::Yes(_
))
2632 || !matches
!(ext
, Extern
::None
)
2636 impl Default
for FnHeader
{
2637 fn default() -> FnHeader
{
2639 unsafety
: Unsafe
::No
,
2640 asyncness
: Async
::No
,
2641 constness
: Const
::No
,
2647 #[derive(Clone, Encodable, Decodable, Debug)]
2648 pub struct TraitKind(
2653 pub Vec
<P
<AssocItem
>>,
2656 #[derive(Clone, Encodable, Decodable, Debug)]
2657 pub struct TyAliasKind(pub Defaultness
, pub Generics
, pub GenericBounds
, pub Option
<P
<Ty
>>);
2659 #[derive(Clone, Encodable, Decodable, Debug)]
2660 pub struct ImplKind
{
2661 pub unsafety
: Unsafe
,
2662 pub polarity
: ImplPolarity
,
2663 pub defaultness
: Defaultness
,
2664 pub constness
: Const
,
2665 pub generics
: Generics
,
2667 /// The trait being implemented, if any.
2668 pub of_trait
: Option
<TraitRef
>,
2671 pub items
: Vec
<P
<AssocItem
>>,
2674 #[derive(Clone, Encodable, Decodable, Debug)]
2675 pub struct FnKind(pub Defaultness
, pub FnSig
, pub Generics
, pub Option
<P
<Block
>>);
2677 #[derive(Clone, Encodable, Decodable, Debug)]
2679 /// An `extern crate` item, with the optional *original* crate name if the crate was renamed.
2681 /// E.g., `extern crate foo` or `extern crate foo_bar as foo`.
2682 ExternCrate(Option
<Symbol
>),
2683 /// A use declaration item (`use`).
2685 /// E.g., `use foo;`, `use foo::bar;` or `use foo::bar as FooBar;`.
2687 /// A static item (`static`).
2689 /// E.g., `static FOO: i32 = 42;` or `static FOO: &'static str = "bar";`.
2690 Static(P
<Ty
>, Mutability
, Option
<P
<Expr
>>),
2691 /// A constant item (`const`).
2693 /// E.g., `const FOO: i32 = 42;`.
2694 Const(Defaultness
, P
<Ty
>, Option
<P
<Expr
>>),
2695 /// A function declaration (`fn`).
2697 /// E.g., `fn foo(bar: usize) -> usize { .. }`.
2699 /// A module declaration (`mod`).
2701 /// E.g., `mod foo;` or `mod foo { .. }`.
2702 /// `unsafe` keyword on modules is accepted syntactically for macro DSLs, but not
2703 /// semantically by Rust.
2704 Mod(Unsafe
, ModKind
),
2705 /// An external module (`extern`).
2707 /// E.g., `extern {}` or `extern "C" {}`.
2708 ForeignMod(ForeignMod
),
2709 /// Module-level inline assembly (from `global_asm!()`).
2710 GlobalAsm(InlineAsm
),
2711 /// A type alias (`type`).
2713 /// E.g., `type Foo = Bar<u8>;`.
2714 TyAlias(Box
<TyAliasKind
>),
2715 /// An enum definition (`enum`).
2717 /// E.g., `enum Foo<A, B> { C<A>, D<B> }`.
2718 Enum(EnumDef
, Generics
),
2719 /// A struct definition (`struct`).
2721 /// E.g., `struct Foo<A> { x: A }`.
2722 Struct(VariantData
, Generics
),
2723 /// A union definition (`union`).
2725 /// E.g., `union Foo<A, B> { x: A, y: B }`.
2726 Union(VariantData
, Generics
),
2727 /// A trait declaration (`trait`).
2729 /// E.g., `trait Foo { .. }`, `trait Foo<T> { .. }` or `auto trait Foo {}`.
2730 Trait(Box
<TraitKind
>),
2733 /// E.g., `trait Foo = Bar + Quux;`.
2734 TraitAlias(Generics
, GenericBounds
),
2735 /// An implementation.
2737 /// E.g., `impl<A> Foo<A> { .. }` or `impl<A> Trait for Foo<A> { .. }`.
2738 Impl(Box
<ImplKind
>),
2739 /// A macro invocation.
2741 /// E.g., `foo!(..)`.
2744 /// A macro definition.
2748 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
2749 rustc_data_structures
::static_assert_size
!(ItemKind
, 112);
2752 pub fn article(&self) -> &str {
2755 Use(..) | Static(..) | Const(..) | Fn(..) | Mod(..) | GlobalAsm(..) | TyAlias(..)
2756 | Struct(..) | Union(..) | Trait(..) | TraitAlias(..) | MacroDef(..) => "a",
2757 ExternCrate(..) | ForeignMod(..) | MacCall(..) | Enum(..) | Impl { .. }
=> "an",
2761 pub fn descr(&self) -> &str {
2763 ItemKind
::ExternCrate(..) => "extern crate",
2764 ItemKind
::Use(..) => "`use` import",
2765 ItemKind
::Static(..) => "static item",
2766 ItemKind
::Const(..) => "constant item",
2767 ItemKind
::Fn(..) => "function",
2768 ItemKind
::Mod(..) => "module",
2769 ItemKind
::ForeignMod(..) => "extern block",
2770 ItemKind
::GlobalAsm(..) => "global asm item",
2771 ItemKind
::TyAlias(..) => "type alias",
2772 ItemKind
::Enum(..) => "enum",
2773 ItemKind
::Struct(..) => "struct",
2774 ItemKind
::Union(..) => "union",
2775 ItemKind
::Trait(..) => "trait",
2776 ItemKind
::TraitAlias(..) => "trait alias",
2777 ItemKind
::MacCall(..) => "item macro invocation",
2778 ItemKind
::MacroDef(..) => "macro definition",
2779 ItemKind
::Impl { .. }
=> "implementation",
2783 pub fn generics(&self) -> Option
<&Generics
> {
2785 Self::Fn(box FnKind(_
, _
, generics
, _
))
2786 | Self::TyAlias(box TyAliasKind(_
, generics
, ..))
2787 | Self::Enum(_
, generics
)
2788 | Self::Struct(_
, generics
)
2789 | Self::Union(_
, generics
)
2790 | Self::Trait(box TraitKind(_
, _
, generics
, ..))
2791 | Self::TraitAlias(generics
, _
)
2792 | Self::Impl(box ImplKind { generics, .. }
) => Some(generics
),
2798 /// Represents associated items.
2799 /// These include items in `impl` and `trait` definitions.
2800 pub type AssocItem
= Item
<AssocItemKind
>;
2802 /// Represents associated item kinds.
2804 /// The term "provided" in the variants below refers to the item having a default
2805 /// definition / body. Meanwhile, a "required" item lacks a definition / body.
2806 /// In an implementation, all items must be provided.
2807 /// The `Option`s below denote the bodies, where `Some(_)`
2808 /// means "provided" and conversely `None` means "required".
2809 #[derive(Clone, Encodable, Decodable, Debug)]
2810 pub enum AssocItemKind
{
2811 /// An associated constant, `const $ident: $ty $def?;` where `def ::= "=" $expr? ;`.
2812 /// If `def` is parsed, then the constant is provided, and otherwise required.
2813 Const(Defaultness
, P
<Ty
>, Option
<P
<Expr
>>),
2814 /// An associated function.
2816 /// An associated type.
2817 TyAlias(Box
<TyAliasKind
>),
2818 /// A macro expanding to associated items.
2822 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
2823 rustc_data_structures
::static_assert_size
!(AssocItemKind
, 72);
2825 impl AssocItemKind
{
2826 pub fn defaultness(&self) -> Defaultness
{
2828 Self::Const(def
, ..)
2829 | Self::Fn(box FnKind(def
, ..))
2830 | Self::TyAlias(box TyAliasKind(def
, ..)) => def
,
2831 Self::MacCall(..) => Defaultness
::Final
,
2836 impl From
<AssocItemKind
> for ItemKind
{
2837 fn from(assoc_item_kind
: AssocItemKind
) -> ItemKind
{
2838 match assoc_item_kind
{
2839 AssocItemKind
::Const(a
, b
, c
) => ItemKind
::Const(a
, b
, c
),
2840 AssocItemKind
::Fn(fn_kind
) => ItemKind
::Fn(fn_kind
),
2841 AssocItemKind
::TyAlias(ty_alias_kind
) => ItemKind
::TyAlias(ty_alias_kind
),
2842 AssocItemKind
::MacCall(a
) => ItemKind
::MacCall(a
),
2847 impl TryFrom
<ItemKind
> for AssocItemKind
{
2848 type Error
= ItemKind
;
2850 fn try_from(item_kind
: ItemKind
) -> Result
<AssocItemKind
, ItemKind
> {
2851 Ok(match item_kind
{
2852 ItemKind
::Const(a
, b
, c
) => AssocItemKind
::Const(a
, b
, c
),
2853 ItemKind
::Fn(fn_kind
) => AssocItemKind
::Fn(fn_kind
),
2854 ItemKind
::TyAlias(ty_alias_kind
) => AssocItemKind
::TyAlias(ty_alias_kind
),
2855 ItemKind
::MacCall(a
) => AssocItemKind
::MacCall(a
),
2856 _
=> return Err(item_kind
),
2861 /// An item in `extern` block.
2862 #[derive(Clone, Encodable, Decodable, Debug)]
2863 pub enum ForeignItemKind
{
2864 /// A foreign static item (`static FOO: u8`).
2865 Static(P
<Ty
>, Mutability
, Option
<P
<Expr
>>),
2866 /// An foreign function.
2868 /// An foreign type.
2869 TyAlias(Box
<TyAliasKind
>),
2870 /// A macro expanding to foreign items.
2874 #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
2875 rustc_data_structures
::static_assert_size
!(ForeignItemKind
, 72);
2877 impl From
<ForeignItemKind
> for ItemKind
{
2878 fn from(foreign_item_kind
: ForeignItemKind
) -> ItemKind
{
2879 match foreign_item_kind
{
2880 ForeignItemKind
::Static(a
, b
, c
) => ItemKind
::Static(a
, b
, c
),
2881 ForeignItemKind
::Fn(fn_kind
) => ItemKind
::Fn(fn_kind
),
2882 ForeignItemKind
::TyAlias(ty_alias_kind
) => ItemKind
::TyAlias(ty_alias_kind
),
2883 ForeignItemKind
::MacCall(a
) => ItemKind
::MacCall(a
),
2888 impl TryFrom
<ItemKind
> for ForeignItemKind
{
2889 type Error
= ItemKind
;
2891 fn try_from(item_kind
: ItemKind
) -> Result
<ForeignItemKind
, ItemKind
> {
2892 Ok(match item_kind
{
2893 ItemKind
::Static(a
, b
, c
) => ForeignItemKind
::Static(a
, b
, c
),
2894 ItemKind
::Fn(fn_kind
) => ForeignItemKind
::Fn(fn_kind
),
2895 ItemKind
::TyAlias(ty_alias_kind
) => ForeignItemKind
::TyAlias(ty_alias_kind
),
2896 ItemKind
::MacCall(a
) => ForeignItemKind
::MacCall(a
),
2897 _
=> return Err(item_kind
),
2902 pub type ForeignItem
= Item
<ForeignItemKind
>;