1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // The Rust abstract syntax tree.
13 pub use self::UnsafeSource::*;
14 pub use self::GenericArgs::*;
15 pub use symbol::{Ident, Symbol as Name};
16 pub use util::parser::ExprPrecedence;
18 use syntax_pos::{Span, DUMMY_SP};
19 use source_map::{dummy_spanned, respan, Spanned};
20 use rustc_target::spec::abi::Abi;
21 use ext::hygiene::{Mark, SyntaxContext};
24 use rustc_data_structures::indexed_vec;
25 use rustc_data_structures::indexed_vec::Idx;
26 use symbol::{Symbol, keywords};
28 use tokenstream::{ThinTokenStream, TokenStream};
30 use serialize::{self, Encoder, Decoder};
31 use std::collections::HashSet;
33 use rustc_data_structures::sync::Lrc;
36 pub use rustc_target::abi::FloatTy;
38 #[derive(Clone, RustcEncodable, RustcDecodable, Copy)]
43 impl fmt::Debug for Label {
44 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
45 write!(f, "label({:?})", self.ident)
49 #[derive(Clone, RustcEncodable, RustcDecodable, Copy)]
55 impl fmt::Debug for Lifetime {
56 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
57 write!(f, "lifetime({}: {})", self.id, pprust::lifetime_to_string(self))
61 /// A "Path" is essentially Rust's notion of a name.
63 /// It's represented as a sequence of identifiers,
64 /// along with a bunch of supporting information.
66 /// E.g. `std::cmp::PartialEq`
67 #[derive(Clone, RustcEncodable, RustcDecodable)]
70 /// The segments in the path: the things separated by `::`.
71 /// Global paths begin with `keywords::CrateRoot`.
72 pub segments: Vec<PathSegment>,
75 impl<'a> PartialEq<&'a str> for Path {
76 fn eq(&self, string: &&'a str) -> bool {
77 self.segments.len() == 1 && self.segments[0].ident.name == *string
81 impl fmt::Debug for Path {
82 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
83 write!(f, "path({})", pprust::path_to_string(self))
87 impl fmt::Display for Path {
88 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
89 write!(f, "{}", pprust::path_to_string(self))
94 // convert a span and an identifier to the corresponding
96 pub fn from_ident(ident: Ident) -> Path {
97 Path { segments: vec![PathSegment::from_ident(ident)], span: ident.span }
100 // Make a "crate root" segment for this path unless it already has it
101 // or starts with something like `self`/`super`/`$crate`/etc.
102 pub fn make_root(&self) -> Option<PathSegment> {
103 if let Some(ident) = self.segments.get(0).map(|seg| seg.ident) {
104 if ident.is_path_segment_keyword() {
108 Some(PathSegment::crate_root(self.span.shrink_to_lo()))
111 pub fn is_global(&self) -> bool {
112 !self.segments.is_empty() && self.segments[0].ident.name == keywords::CrateRoot.name()
116 /// A segment of a path: an identifier, an optional lifetime, and a set of types.
118 /// E.g. `std`, `String` or `Box<T>`
119 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
120 pub struct PathSegment {
121 /// The identifier portion of this path segment.
124 /// Type/lifetime parameters attached to this path. They come in
125 /// two flavors: `Path<A,B,C>` and `Path(A,B) -> C`.
126 /// `None` means that no parameter list is supplied (`Path`),
127 /// `Some` means that parameter list is supplied (`Path<X, Y>`)
128 /// but it can be empty (`Path<>`).
129 /// `P` is used as a size optimization for the common case with no parameters.
130 pub args: Option<P<GenericArgs>>,
134 pub fn from_ident(ident: Ident) -> Self {
135 PathSegment { ident, args: None }
137 pub fn crate_root(span: Span) -> Self {
138 PathSegment::from_ident(Ident::new(keywords::CrateRoot.name(), span))
142 /// Arguments of a path segment.
144 /// E.g. `<A, B>` as in `Foo<A, B>` or `(A, B)` as in `Foo(A, B)`
145 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
146 pub enum GenericArgs {
147 /// The `<'a, A,B,C>` in `foo::bar::baz::<'a, A,B,C>`
148 AngleBracketed(AngleBracketedArgs),
149 /// The `(A,B)` and `C` in `Foo(A,B) -> C`
150 Parenthesized(ParenthesisedArgs),
154 pub fn span(&self) -> Span {
156 AngleBracketed(ref data) => data.span,
157 Parenthesized(ref data) => data.span,
162 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
163 pub enum GenericArg {
168 /// A path like `Foo<'a, T>`
169 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Default)]
170 pub struct AngleBracketedArgs {
173 /// The arguments for this path segment.
174 pub args: Vec<GenericArg>,
175 /// Bindings (equality constraints) on associated types, if present.
177 /// E.g., `Foo<A=Bar>`.
178 pub bindings: Vec<TypeBinding>,
181 impl Into<Option<P<GenericArgs>>> for AngleBracketedArgs {
182 fn into(self) -> Option<P<GenericArgs>> {
183 Some(P(GenericArgs::AngleBracketed(self)))
187 impl Into<Option<P<GenericArgs>>> for ParenthesisedArgs {
188 fn into(self) -> Option<P<GenericArgs>> {
189 Some(P(GenericArgs::Parenthesized(self)))
193 /// A path like `Foo(A,B) -> C`
194 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
195 pub struct ParenthesisedArgs {
200 pub inputs: Vec<P<Ty>>,
203 pub output: Option<P<Ty>>,
206 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
207 pub struct NodeId(u32);
210 pub fn new(x: usize) -> NodeId {
211 assert!(x < (u32::MAX as usize));
215 pub fn from_u32(x: u32) -> NodeId {
219 pub fn as_usize(&self) -> usize {
223 pub fn as_u32(&self) -> u32 {
227 pub fn placeholder_from_mark(mark: Mark) -> Self {
228 NodeId(mark.as_u32())
231 pub fn placeholder_to_mark(self) -> Mark {
232 Mark::from_u32(self.0)
236 impl fmt::Display for NodeId {
237 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
238 fmt::Display::fmt(&self.0, f)
242 impl serialize::UseSpecializedEncodable for NodeId {
243 fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
248 impl serialize::UseSpecializedDecodable for NodeId {
249 fn default_decode<D: Decoder>(d: &mut D) -> Result<NodeId, D::Error> {
250 d.read_u32().map(NodeId)
254 impl indexed_vec::Idx for NodeId {
255 fn new(idx: usize) -> Self {
259 fn index(self) -> usize {
264 /// Node id used to represent the root of the crate.
265 pub const CRATE_NODE_ID: NodeId = NodeId(0);
267 /// When parsing and doing expansions, we initially give all AST nodes this AST
268 /// node value. Then later, in the renumber pass, we renumber them to have
269 /// small, positive ids.
270 pub const DUMMY_NODE_ID: NodeId = NodeId(!0);
272 /// A modifier on a bound, currently this is only used for `?Sized`, where the
273 /// modifier is `Maybe`. Negative bounds should also be handled here.
274 #[derive(Copy, Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Debug)]
275 pub enum TraitBoundModifier {
280 /// The AST represents all type param bounds as types.
281 /// typeck::collect::compute_bounds matches these against
282 /// the "special" built-in traits (see middle::lang_items) and
283 /// detects Copy, Send and Sync.
284 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
285 pub enum GenericBound {
286 Trait(PolyTraitRef, TraitBoundModifier),
291 pub fn span(&self) -> Span {
293 &GenericBound::Trait(ref t, ..) => t.span,
294 &GenericBound::Outlives(ref l) => l.ident.span,
299 pub type GenericBounds = Vec<GenericBound>;
301 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
302 pub enum GenericParamKind {
303 /// A lifetime definition, e.g. `'a: 'b+'c+'d`.
306 default: Option<P<Ty>>,
310 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
311 pub struct GenericParam {
314 pub attrs: ThinVec<Attribute>,
315 pub bounds: GenericBounds,
317 pub kind: GenericParamKind,
320 /// Represents lifetime, type and const parameters attached to a declaration of
321 /// a function, enum, trait, etc.
322 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
323 pub struct Generics {
324 pub params: Vec<GenericParam>,
325 pub where_clause: WhereClause,
329 impl Default for Generics {
330 /// Creates an instance of `Generics`.
331 fn default() -> Generics {
334 where_clause: WhereClause {
336 predicates: Vec::new(),
344 /// A `where` clause in a definition
345 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
346 pub struct WhereClause {
348 pub predicates: Vec<WherePredicate>,
352 /// A single predicate in a `where` clause
353 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
354 pub enum WherePredicate {
355 /// A type binding, e.g. `for<'c> Foo: Send+Clone+'c`
356 BoundPredicate(WhereBoundPredicate),
357 /// A lifetime predicate, e.g. `'a: 'b+'c`
358 RegionPredicate(WhereRegionPredicate),
359 /// An equality predicate (unsupported)
360 EqPredicate(WhereEqPredicate),
363 impl WherePredicate {
364 pub fn span(&self) -> Span {
366 &WherePredicate::BoundPredicate(ref p) => p.span,
367 &WherePredicate::RegionPredicate(ref p) => p.span,
368 &WherePredicate::EqPredicate(ref p) => p.span,
375 /// E.g. `for<'c> Foo: Send+Clone+'c`
376 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
377 pub struct WhereBoundPredicate {
379 /// Any generics from a `for` binding
380 pub bound_generic_params: Vec<GenericParam>,
381 /// The type being bounded
382 pub bounded_ty: P<Ty>,
383 /// Trait and lifetime bounds (`Clone+Send+'static`)
384 pub bounds: GenericBounds,
387 /// A lifetime predicate.
390 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
391 pub struct WhereRegionPredicate {
393 pub lifetime: Lifetime,
394 pub bounds: GenericBounds,
397 /// An equality predicate (unsupported).
400 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
401 pub struct WhereEqPredicate {
408 /// The set of MetaItems that define the compilation environment of the crate,
409 /// used to drive conditional compilation
410 pub type CrateConfig = HashSet<(Name, Option<Symbol>)>;
412 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
415 pub attrs: Vec<Attribute>,
419 /// A spanned compile-time attribute list item.
420 pub type NestedMetaItem = Spanned<NestedMetaItemKind>;
422 /// Possible values inside of compile-time attribute lists.
424 /// E.g. the '..' in `#[name(..)]`.
425 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
426 pub enum NestedMetaItemKind {
427 /// A full MetaItem, for recursive meta items.
431 /// E.g. "foo", 64, true
435 /// A spanned compile-time attribute item.
437 /// E.g. `#[test]`, `#[derive(..)]`, `#[rustfmt::skip]` or `#[feature = "foo"]`
438 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
439 pub struct MetaItem {
441 pub node: MetaItemKind,
445 /// A compile-time attribute item.
447 /// E.g. `#[test]`, `#[derive(..)]` or `#[feature = "foo"]`
448 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
449 pub enum MetaItemKind {
452 /// E.g. `test` as in `#[test]`
456 /// E.g. `derive(..)` as in `#[derive(..)]`
457 List(Vec<NestedMetaItem>),
458 /// Name value meta item.
460 /// E.g. `feature = "foo"` as in `#[feature = "foo"]`
464 /// A Block (`{ .. }`).
466 /// E.g. `{ .. }` as in `fn foo() { .. }`
467 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
469 /// Statements in a block
470 pub stmts: Vec<Stmt>,
472 /// Distinguishes between `unsafe { ... }` and `{ ... }`
473 pub rules: BlockCheckMode,
478 #[derive(Clone, RustcEncodable, RustcDecodable)]
485 impl fmt::Debug for Pat {
486 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
487 write!(f, "pat({}: {})", self.id, pprust::pat_to_string(self))
492 pub(super) fn to_ty(&self) -> Option<P<Ty>> {
493 let node = match &self.node {
494 PatKind::Wild => TyKind::Infer,
495 PatKind::Ident(BindingMode::ByValue(Mutability::Immutable), ident, None) =>
496 TyKind::Path(None, Path::from_ident(*ident)),
497 PatKind::Path(qself, path) => TyKind::Path(qself.clone(), path.clone()),
498 PatKind::Mac(mac) => TyKind::Mac(mac.clone()),
499 PatKind::Ref(pat, mutbl) =>
500 pat.to_ty().map(|ty| TyKind::Rptr(None, MutTy { ty, mutbl: *mutbl }))?,
501 PatKind::Slice(pats, None, _) if pats.len() == 1 =>
502 pats[0].to_ty().map(TyKind::Slice)?,
503 PatKind::Tuple(pats, None) => {
504 let mut tys = Vec::with_capacity(pats.len());
505 // FIXME(#48994) - could just be collected into an Option<Vec>
507 tys.push(pat.to_ty()?);
514 Some(P(Ty { node, id: self.id, span: self.span }))
517 pub fn walk<F>(&self, it: &mut F) -> bool
518 where F: FnMut(&Pat) -> bool
525 PatKind::Ident(_, _, Some(ref p)) => p.walk(it),
526 PatKind::Struct(_, ref fields, _) => {
527 fields.iter().all(|field| field.node.pat.walk(it))
529 PatKind::TupleStruct(_, ref s, _) | PatKind::Tuple(ref s, _) => {
530 s.iter().all(|p| p.walk(it))
532 PatKind::Box(ref s) | PatKind::Ref(ref s, _) | PatKind::Paren(ref s) => {
535 PatKind::Slice(ref before, ref slice, ref after) => {
536 before.iter().all(|p| p.walk(it)) &&
537 slice.iter().all(|p| p.walk(it)) &&
538 after.iter().all(|p| p.walk(it))
552 /// A single field in a struct pattern
554 /// Patterns like the fields of Foo `{ x, ref y, ref mut z }`
555 /// are treated the same as` x: x, y: ref y, z: ref mut z`,
556 /// except is_shorthand is true
557 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
558 pub struct FieldPat {
559 /// The identifier for the field
561 /// The pattern the field is destructured to
563 pub is_shorthand: bool,
564 pub attrs: ThinVec<Attribute>,
567 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
568 pub enum BindingMode {
573 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
575 Included(RangeSyntax),
579 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
580 pub enum RangeSyntax {
585 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
587 /// Represents a wildcard pattern (`_`)
590 /// A `PatKind::Ident` may either be a new bound variable (`ref mut binding @ OPT_SUBPATTERN`),
591 /// or a unit struct/variant pattern, or a const pattern (in the last two cases the third
592 /// field must be `None`). Disambiguation cannot be done with parser alone, so it happens
593 /// during name resolution.
594 Ident(BindingMode, Ident, Option<P<Pat>>),
596 /// A struct or struct variant pattern, e.g. `Variant {x, y, ..}`.
597 /// The `bool` is `true` in the presence of a `..`.
598 Struct(Path, Vec<Spanned<FieldPat>>, bool),
600 /// A tuple struct/variant pattern `Variant(x, y, .., z)`.
601 /// If the `..` pattern fragment is present, then `Option<usize>` denotes its position.
602 /// 0 <= position <= subpats.len()
603 TupleStruct(Path, Vec<P<Pat>>, Option<usize>),
605 /// A possibly qualified path pattern.
606 /// Unqualified path patterns `A::B::C` can legally refer to variants, structs, constants
607 /// or associated constants. Qualified path patterns `<A>::B::C`/`<A as Trait>::B::C` can
608 /// only legally refer to associated constants.
609 Path(Option<QSelf>, Path),
611 /// A tuple pattern `(a, b)`.
612 /// If the `..` pattern fragment is present, then `Option<usize>` denotes its position.
613 /// 0 <= position <= subpats.len()
614 Tuple(Vec<P<Pat>>, Option<usize>),
617 /// A reference pattern, e.g. `&mut (a, b)`
618 Ref(P<Pat>, Mutability),
621 /// A range pattern, e.g. `1...2`, `1..=2` or `1..2`
622 Range(P<Expr>, P<Expr>, Spanned<RangeEnd>),
623 /// `[a, b, ..i, y, z]` is represented as:
624 /// `PatKind::Slice(box [a, b], Some(i), box [y, z])`
625 Slice(Vec<P<Pat>>, Option<P<Pat>>, Vec<P<Pat>>),
626 /// Parentheses in patters used for grouping, i.e. `(PAT)`.
628 /// A macro pattern; pre-expansion
632 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable, Debug, Copy)]
633 pub enum Mutability {
638 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
640 /// The `+` operator (addition)
642 /// The `-` operator (subtraction)
644 /// The `*` operator (multiplication)
646 /// The `/` operator (division)
648 /// The `%` operator (modulus)
650 /// The `&&` operator (logical and)
652 /// The `||` operator (logical or)
654 /// The `^` operator (bitwise xor)
656 /// The `&` operator (bitwise and)
658 /// The `|` operator (bitwise or)
660 /// The `<<` operator (shift left)
662 /// The `>>` operator (shift right)
664 /// The `==` operator (equality)
666 /// The `<` operator (less than)
668 /// The `<=` operator (less than or equal to)
670 /// The `!=` operator (not equal to)
672 /// The `>=` operator (greater than or equal to)
674 /// The `>` operator (greater than)
679 pub fn to_string(&self) -> &'static str {
680 use self::BinOpKind::*;
702 pub fn lazy(&self) -> bool {
704 BinOpKind::And | BinOpKind::Or => true,
709 pub fn is_shift(&self) -> bool {
711 BinOpKind::Shl | BinOpKind::Shr => true,
716 pub fn is_comparison(&self) -> bool {
717 use self::BinOpKind::*;
719 Eq | Lt | Le | Ne | Gt | Ge =>
721 And | Or | Add | Sub | Mul | Div | Rem |
722 BitXor | BitAnd | BitOr | Shl | Shr =>
727 /// Returns `true` if the binary operator takes its arguments by value
728 pub fn is_by_value(&self) -> bool {
729 !self.is_comparison()
733 pub type BinOp = Spanned<BinOpKind>;
735 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy)]
737 /// The `*` operator for dereferencing
739 /// The `!` operator for logical inversion
741 /// The `-` operator for negation
746 /// Returns `true` if the unary operator takes its argument by value
747 pub fn is_by_value(u: UnOp) -> bool {
749 UnOp::Neg | UnOp::Not => true,
754 pub fn to_string(op: UnOp) -> &'static str {
764 #[derive(Clone, RustcEncodable, RustcDecodable)]
772 pub fn add_trailing_semicolon(mut self) -> Self {
773 self.node = match self.node {
774 StmtKind::Expr(expr) => StmtKind::Semi(expr),
775 StmtKind::Mac(mac) => StmtKind::Mac(mac.map(|(mac, _style, attrs)| {
776 (mac, MacStmtStyle::Semicolon, attrs)
783 pub fn is_item(&self) -> bool {
785 StmtKind::Item(_) => true,
790 pub fn is_expr(&self) -> bool {
792 StmtKind::Expr(_) => true,
798 impl fmt::Debug for Stmt {
799 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
800 write!(f, "stmt({}: {})", self.id.to_string(), pprust::stmt_to_string(self))
805 #[derive(Clone, RustcEncodable, RustcDecodable)]
807 /// A local (let) binding.
810 /// An item definition.
813 /// Expr without trailing semi-colon.
815 /// Expr with a trailing semi-colon.
818 Mac(P<(Mac, MacStmtStyle, ThinVec<Attribute>)>),
821 #[derive(Clone, Copy, PartialEq, RustcEncodable, RustcDecodable, Debug)]
822 pub enum MacStmtStyle {
823 /// The macro statement had a trailing semicolon, e.g. `foo! { ... };`
824 /// `foo!(...);`, `foo![...];`
826 /// The macro statement had braces; e.g. foo! { ... }
828 /// The macro statement had parentheses or brackets and no semicolon; e.g.
829 /// `foo!(...)`. All of these will end up being converted into macro
834 /// Local represents a `let` statement, e.g., `let <pat>:<ty> = <expr>;`
835 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
838 pub ty: Option<P<Ty>>,
839 /// Initializer expression to set the value, if any
840 pub init: Option<P<Expr>>,
843 pub attrs: ThinVec<Attribute>,
846 /// An arm of a 'match'.
848 /// E.g. `0..=10 => { println!("match!") }` as in
852 /// 0..=10 => { println!("match!") },
853 /// _ => { println!("no match!") },
856 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
858 pub attrs: Vec<Attribute>,
859 pub pats: Vec<P<Pat>>,
860 pub guard: Option<Guard>,
864 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
869 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
874 pub is_shorthand: bool,
875 pub attrs: ThinVec<Attribute>,
878 pub type SpannedIdent = Spanned<Ident>;
880 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy)]
881 pub enum BlockCheckMode {
883 Unsafe(UnsafeSource),
886 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy)]
887 pub enum UnsafeSource {
892 /// A constant (expression) that's not an item or associated item,
893 /// but needs its own `DefId` for type-checking, const-eval, etc.
894 /// These are usually found nested inside types (e.g. array lengths)
895 /// or expressions (e.g. repeat counts), and also used to define
896 /// explicit discriminant values for enum variants.
897 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
898 pub struct AnonConst {
905 #[derive(Clone, RustcEncodable, RustcDecodable)]
910 pub attrs: ThinVec<Attribute>
914 /// Whether this expression would be valid somewhere that expects a value, for example, an `if`
916 pub fn returns(&self) -> bool {
917 if let ExprKind::Block(ref block, _) = self.node {
918 match block.stmts.last().map(|last_stmt| &last_stmt.node) {
920 Some(&StmtKind::Expr(_)) => true,
921 Some(&StmtKind::Semi(ref expr)) => {
922 if let ExprKind::Ret(_) = expr.node {
923 // last statement is explicit return
929 // This is a block that doesn't end in either an implicit or explicit return
933 // This is not a block, it is a value
938 fn to_bound(&self) -> Option<GenericBound> {
940 ExprKind::Path(None, path) =>
941 Some(GenericBound::Trait(PolyTraitRef::new(Vec::new(), path.clone(), self.span),
942 TraitBoundModifier::None)),
947 pub(super) fn to_ty(&self) -> Option<P<Ty>> {
948 let node = match &self.node {
949 ExprKind::Path(qself, path) => TyKind::Path(qself.clone(), path.clone()),
950 ExprKind::Mac(mac) => TyKind::Mac(mac.clone()),
951 ExprKind::Paren(expr) => expr.to_ty().map(TyKind::Paren)?,
952 ExprKind::AddrOf(mutbl, expr) =>
953 expr.to_ty().map(|ty| TyKind::Rptr(None, MutTy { ty, mutbl: *mutbl }))?,
954 ExprKind::Repeat(expr, expr_len) =>
955 expr.to_ty().map(|ty| TyKind::Array(ty, expr_len.clone()))?,
956 ExprKind::Array(exprs) if exprs.len() == 1 =>
957 exprs[0].to_ty().map(TyKind::Slice)?,
958 ExprKind::Tup(exprs) => {
959 let tys = exprs.iter().map(|expr| expr.to_ty()).collect::<Option<Vec<_>>>()?;
962 ExprKind::Binary(binop, lhs, rhs) if binop.node == BinOpKind::Add =>
963 if let (Some(lhs), Some(rhs)) = (lhs.to_bound(), rhs.to_bound()) {
964 TyKind::TraitObject(vec![lhs, rhs], TraitObjectSyntax::None)
971 Some(P(Ty { node, id: self.id, span: self.span }))
974 pub fn precedence(&self) -> ExprPrecedence {
976 ExprKind::Box(_) => ExprPrecedence::Box,
977 ExprKind::ObsoleteInPlace(..) => ExprPrecedence::ObsoleteInPlace,
978 ExprKind::Array(_) => ExprPrecedence::Array,
979 ExprKind::Call(..) => ExprPrecedence::Call,
980 ExprKind::MethodCall(..) => ExprPrecedence::MethodCall,
981 ExprKind::Tup(_) => ExprPrecedence::Tup,
982 ExprKind::Binary(op, ..) => ExprPrecedence::Binary(op.node),
983 ExprKind::Unary(..) => ExprPrecedence::Unary,
984 ExprKind::Lit(_) => ExprPrecedence::Lit,
985 ExprKind::Type(..) | ExprKind::Cast(..) => ExprPrecedence::Cast,
986 ExprKind::If(..) => ExprPrecedence::If,
987 ExprKind::IfLet(..) => ExprPrecedence::IfLet,
988 ExprKind::While(..) => ExprPrecedence::While,
989 ExprKind::WhileLet(..) => ExprPrecedence::WhileLet,
990 ExprKind::ForLoop(..) => ExprPrecedence::ForLoop,
991 ExprKind::Loop(..) => ExprPrecedence::Loop,
992 ExprKind::Match(..) => ExprPrecedence::Match,
993 ExprKind::Closure(..) => ExprPrecedence::Closure,
994 ExprKind::Block(..) => ExprPrecedence::Block,
995 ExprKind::Catch(..) => ExprPrecedence::Catch,
996 ExprKind::Async(..) => ExprPrecedence::Async,
997 ExprKind::Assign(..) => ExprPrecedence::Assign,
998 ExprKind::AssignOp(..) => ExprPrecedence::AssignOp,
999 ExprKind::Field(..) => ExprPrecedence::Field,
1000 ExprKind::Index(..) => ExprPrecedence::Index,
1001 ExprKind::Range(..) => ExprPrecedence::Range,
1002 ExprKind::Path(..) => ExprPrecedence::Path,
1003 ExprKind::AddrOf(..) => ExprPrecedence::AddrOf,
1004 ExprKind::Break(..) => ExprPrecedence::Break,
1005 ExprKind::Continue(..) => ExprPrecedence::Continue,
1006 ExprKind::Ret(..) => ExprPrecedence::Ret,
1007 ExprKind::InlineAsm(..) => ExprPrecedence::InlineAsm,
1008 ExprKind::Mac(..) => ExprPrecedence::Mac,
1009 ExprKind::Struct(..) => ExprPrecedence::Struct,
1010 ExprKind::Repeat(..) => ExprPrecedence::Repeat,
1011 ExprKind::Paren(..) => ExprPrecedence::Paren,
1012 ExprKind::Try(..) => ExprPrecedence::Try,
1013 ExprKind::Yield(..) => ExprPrecedence::Yield,
1018 impl fmt::Debug for Expr {
1019 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1020 write!(f, "expr({}: {})", self.id, pprust::expr_to_string(self))
1024 /// Limit types of a range (inclusive or exclusive)
1025 #[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
1026 pub enum RangeLimits {
1027 /// Inclusive at the beginning, exclusive at the end
1029 /// Inclusive at the beginning and end
1033 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1035 /// A `box x` expression.
1037 /// First expr is the place; second expr is the value.
1038 ObsoleteInPlace(P<Expr>, P<Expr>),
1039 /// An array (`[a, b, c, d]`)
1040 Array(Vec<P<Expr>>),
1043 /// The first field resolves to the function itself,
1044 /// and the second field is the list of arguments.
1045 /// This also represents calling the constructor of
1046 /// tuple-like ADTs such as tuple structs and enum variants.
1047 Call(P<Expr>, Vec<P<Expr>>),
1048 /// A method call (`x.foo::<'static, Bar, Baz>(a, b, c, d)`)
1050 /// The `PathSegment` represents the method name and its generic arguments
1051 /// (within the angle brackets).
1052 /// The first element of the vector of `Expr`s is the expression that evaluates
1053 /// to the object on which the method is being called on (the receiver),
1054 /// and the remaining elements are the rest of the arguments.
1055 /// Thus, `x.foo::<Bar, Baz>(a, b, c, d)` is represented as
1056 /// `ExprKind::MethodCall(PathSegment { foo, [Bar, Baz] }, [x, a, b, c, d])`.
1057 MethodCall(PathSegment, Vec<P<Expr>>),
1058 /// A tuple (`(a, b, c ,d)`)
1060 /// A binary operation (For example: `a + b`, `a * b`)
1061 Binary(BinOp, P<Expr>, P<Expr>),
1062 /// A unary operation (For example: `!x`, `*x`)
1063 Unary(UnOp, P<Expr>),
1064 /// A literal (For example: `1`, `"foo"`)
1066 /// A cast (`foo as f64`)
1067 Cast(P<Expr>, P<Ty>),
1068 Type(P<Expr>, P<Ty>),
1069 /// An `if` block, with an optional else block
1071 /// `if expr { block } else { expr }`
1072 If(P<Expr>, P<Block>, Option<P<Expr>>),
1073 /// An `if let` expression with an optional else block
1075 /// `if let pat = expr { block } else { expr }`
1077 /// This is desugared to a `match` expression.
1078 IfLet(Vec<P<Pat>>, P<Expr>, P<Block>, Option<P<Expr>>),
1079 /// A while loop, with an optional label
1081 /// `'label: while expr { block }`
1082 While(P<Expr>, P<Block>, Option<Label>),
1083 /// A while-let loop, with an optional label
1085 /// `'label: while let pat = expr { block }`
1087 /// This is desugared to a combination of `loop` and `match` expressions.
1088 WhileLet(Vec<P<Pat>>, P<Expr>, P<Block>, Option<Label>),
1089 /// A for loop, with an optional label
1091 /// `'label: for pat in expr { block }`
1093 /// This is desugared to a combination of `loop` and `match` expressions.
1094 ForLoop(P<Pat>, P<Expr>, P<Block>, Option<Label>),
1095 /// Conditionless loop (can be exited with break, continue, or return)
1097 /// `'label: loop { block }`
1098 Loop(P<Block>, Option<Label>),
1099 /// A `match` block.
1100 Match(P<Expr>, Vec<Arm>),
1101 /// A closure (for example, `move |a, b, c| a + b + c`)
1103 /// The final span is the span of the argument block `|...|`
1104 Closure(CaptureBy, IsAsync, Movability, P<FnDecl>, P<Expr>, Span),
1105 /// A block (`'label: { ... }`)
1106 Block(P<Block>, Option<Label>),
1107 /// An async block (`async move { ... }`)
1109 /// The `NodeId` is the `NodeId` for the closure that results from
1110 /// desugaring an async block, just like the NodeId field in the
1111 /// `IsAsync` enum. This is necessary in order to create a def for the
1112 /// closure which can be used as a parent of any child defs. Defs
1113 /// created during lowering cannot be made the parent of any other
1114 /// preexisting defs.
1115 Async(CaptureBy, NodeId, P<Block>),
1116 /// A catch block (`catch { ... }`)
1119 /// An assignment (`a = foo()`)
1120 Assign(P<Expr>, P<Expr>),
1121 /// An assignment with an operator
1123 /// For example, `a += 1`.
1124 AssignOp(BinOp, P<Expr>, P<Expr>),
1125 /// Access of a named (`obj.foo`) or unnamed (`obj.0`) struct field
1126 Field(P<Expr>, Ident),
1127 /// An indexing operation (`foo[2]`)
1128 Index(P<Expr>, P<Expr>),
1129 /// A range (`1..2`, `1..`, `..2`, `1...2`, `1...`, `...2`)
1130 Range(Option<P<Expr>>, Option<P<Expr>>, RangeLimits),
1132 /// Variable reference, possibly containing `::` and/or type
1133 /// parameters, e.g. foo::bar::<baz>.
1135 /// Optionally "qualified",
1136 /// E.g. `<Vec<T> as SomeTrait>::SomeType`.
1137 Path(Option<QSelf>, Path),
1139 /// A referencing operation (`&a` or `&mut a`)
1140 AddrOf(Mutability, P<Expr>),
1141 /// A `break`, with an optional label to break, and an optional expression
1142 Break(Option<Label>, Option<P<Expr>>),
1143 /// A `continue`, with an optional label
1144 Continue(Option<Label>),
1145 /// A `return`, with an optional value to be returned
1146 Ret(Option<P<Expr>>),
1148 /// Output of the `asm!()` macro
1149 InlineAsm(P<InlineAsm>),
1151 /// A macro invocation; pre-expansion
1154 /// A struct literal expression.
1156 /// For example, `Foo {x: 1, y: 2}`, or
1157 /// `Foo {x: 1, .. base}`, where `base` is the `Option<Expr>`.
1158 Struct(Path, Vec<Field>, Option<P<Expr>>),
1160 /// An array literal constructed from one repeated element.
1162 /// For example, `[1; 5]`. The expression is the element to be
1163 /// repeated; the constant is the number of times to repeat it.
1164 Repeat(P<Expr>, AnonConst),
1166 /// No-op: used solely so we can pretty-print faithfully
1172 /// A `yield`, with an optional value to be yielded
1173 Yield(Option<P<Expr>>),
1176 /// The explicit Self type in a "qualified path". The actual
1177 /// path, including the trait and the associated item, is stored
1178 /// separately. `position` represents the index of the associated
1179 /// item qualified with this Self type.
1181 /// ```ignore (only-for-syntax-highlight)
1182 /// <Vec<T> as a::b::Trait>::AssociatedItem
1183 /// ^~~~~ ~~~~~~~~~~~~~~^
1186 /// <Vec<T>>::AssociatedItem
1190 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1194 /// The span of `a::b::Trait` in a path like `<Vec<T> as
1195 /// a::b::Trait>::AssociatedItem`; in the case where `position ==
1196 /// 0`, this is an empty span.
1197 pub path_span: Span,
1201 /// A capture clause
1202 #[derive(Clone, Copy, PartialEq, RustcEncodable, RustcDecodable, Debug)]
1203 pub enum CaptureBy {
1208 /// The movability of a generator / closure literal
1209 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
1210 pub enum Movability {
1215 pub type Mac = Spanned<Mac_>;
1217 /// Represents a macro invocation. The Path indicates which macro
1218 /// is being invoked, and the vector of token-trees contains the source
1219 /// of the macro invocation.
1221 /// NB: the additional ident for a macro_rules-style macro is actually
1222 /// stored in the enclosing item. Oog.
1223 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1226 pub delim: MacDelimiter,
1227 pub tts: ThinTokenStream,
1230 #[derive(Copy, Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Debug)]
1231 pub enum MacDelimiter {
1238 pub fn stream(&self) -> TokenStream {
1239 self.tts.clone().into()
1243 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1244 pub struct MacroDef {
1245 pub tokens: ThinTokenStream,
1250 pub fn stream(&self) -> TokenStream {
1251 self.tokens.clone().into()
1255 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy, Hash, PartialEq)]
1257 /// A regular string, like `"foo"`
1259 /// A raw string, like `r##"foo"##`
1261 /// The value is the number of `#` symbols used.
1266 pub type Lit = Spanned<LitKind>;
1268 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy, Hash, PartialEq)]
1269 pub enum LitIntType {
1277 /// E.g. `"foo"`, `42`, `12.34` or `bool`
1278 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Hash, PartialEq)]
1280 /// A string literal (`"foo"`)
1281 Str(Symbol, StrStyle),
1282 /// A byte string (`b"foo"`)
1283 ByteStr(Lrc<Vec<u8>>),
1284 /// A byte char (`b'f'`)
1286 /// A character literal (`'a'`)
1288 /// An integer literal (`1`)
1289 Int(u128, LitIntType),
1290 /// A float literal (`1f64` or `1E10f64`)
1291 Float(Symbol, FloatTy),
1292 /// A float literal without a suffix (`1.0 or 1.0E10`)
1293 FloatUnsuffixed(Symbol),
1294 /// A boolean literal
1299 /// Returns true if this literal is a string and false otherwise.
1300 pub fn is_str(&self) -> bool {
1302 LitKind::Str(..) => true,
1307 /// Returns true if this is a numeric literal.
1308 pub fn is_numeric(&self) -> bool {
1311 LitKind::Float(..) |
1312 LitKind::FloatUnsuffixed(..) => true,
1317 /// Returns true if this literal has no suffix. Note: this will return true
1318 /// for literals with prefixes such as raw strings and byte strings.
1319 pub fn is_unsuffixed(&self) -> bool {
1321 // unsuffixed variants
1323 LitKind::ByteStr(..) |
1326 LitKind::Int(_, LitIntType::Unsuffixed) |
1327 LitKind::FloatUnsuffixed(..) |
1328 LitKind::Bool(..) => true,
1329 // suffixed variants
1330 LitKind::Int(_, LitIntType::Signed(..)) |
1331 LitKind::Int(_, LitIntType::Unsigned(..)) |
1332 LitKind::Float(..) => false,
1336 /// Returns true if this literal has a suffix.
1337 pub fn is_suffixed(&self) -> bool {
1338 !self.is_unsuffixed()
1342 // NB: If you change this, you'll probably want to change the corresponding
1343 // type structure in middle/ty.rs as well.
1344 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1347 pub mutbl: Mutability,
1350 /// Represents a method's signature in a trait declaration,
1351 /// or in an implementation.
1352 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1353 pub struct MethodSig {
1354 pub header: FnHeader,
1355 pub decl: P<FnDecl>,
1358 /// Represents an item declaration within a trait declaration,
1359 /// possibly including a default implementation. A trait item is
1360 /// either required (meaning it doesn't have an implementation, just a
1361 /// signature) or provided (meaning it has a default implementation).
1362 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1363 pub struct TraitItem {
1366 pub attrs: Vec<Attribute>,
1367 pub generics: Generics,
1368 pub node: TraitItemKind,
1370 /// See `Item::tokens` for what this is
1371 pub tokens: Option<TokenStream>,
1374 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1375 pub enum TraitItemKind {
1376 Const(P<Ty>, Option<P<Expr>>),
1377 Method(MethodSig, Option<P<Block>>),
1378 Type(GenericBounds, Option<P<Ty>>),
1382 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1383 pub struct ImplItem {
1386 pub vis: Visibility,
1387 pub defaultness: Defaultness,
1388 pub attrs: Vec<Attribute>,
1389 pub generics: Generics,
1390 pub node: ImplItemKind,
1392 /// See `Item::tokens` for what this is
1393 pub tokens: Option<TokenStream>,
1396 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1397 pub enum ImplItemKind {
1398 Const(P<Ty>, P<Expr>),
1399 Method(MethodSig, P<Block>),
1401 Existential(GenericBounds),
1405 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable, Copy)]
1415 impl fmt::Debug for IntTy {
1416 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1417 fmt::Display::fmt(self, f)
1421 impl fmt::Display for IntTy {
1422 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1423 write!(f, "{}", self.ty_to_string())
1428 pub fn ty_to_string(&self) -> &'static str {
1430 IntTy::Isize => "isize",
1432 IntTy::I16 => "i16",
1433 IntTy::I32 => "i32",
1434 IntTy::I64 => "i64",
1435 IntTy::I128 => "i128",
1439 pub fn val_to_string(&self, val: i128) -> String {
1440 // cast to a u128 so we can correctly print INT128_MIN. All integral types
1441 // are parsed as u128, so we wouldn't want to print an extra negative
1443 format!("{}{}", val as u128, self.ty_to_string())
1446 pub fn bit_width(&self) -> Option<usize> {
1448 IntTy::Isize => return None,
1458 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable, Copy)]
1469 pub fn ty_to_string(&self) -> &'static str {
1471 UintTy::Usize => "usize",
1473 UintTy::U16 => "u16",
1474 UintTy::U32 => "u32",
1475 UintTy::U64 => "u64",
1476 UintTy::U128 => "u128",
1480 pub fn val_to_string(&self, val: u128) -> String {
1481 format!("{}{}", val, self.ty_to_string())
1484 pub fn bit_width(&self) -> Option<usize> {
1486 UintTy::Usize => return None,
1491 UintTy::U128 => 128,
1496 impl fmt::Debug for UintTy {
1497 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1498 fmt::Display::fmt(self, f)
1502 impl fmt::Display for UintTy {
1503 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1504 write!(f, "{}", self.ty_to_string())
1508 // Bind a type to an associated type: `A=Foo`.
1509 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1510 pub struct TypeBinding {
1517 #[derive(Clone, RustcEncodable, RustcDecodable)]
1524 impl fmt::Debug for Ty {
1525 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1526 write!(f, "type({})", pprust::ty_to_string(self))
1530 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1531 pub struct BareFnTy {
1532 pub unsafety: Unsafety,
1534 pub generic_params: Vec<GenericParam>,
1538 /// The different kinds of types recognized by the compiler
1539 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1541 /// A variable-length slice (`[T]`)
1543 /// A fixed length array (`[T; n]`)
1544 Array(P<Ty>, AnonConst),
1545 /// A raw pointer (`*const T` or `*mut T`)
1547 /// A reference (`&'a T` or `&'a mut T`)
1548 Rptr(Option<Lifetime>, MutTy),
1549 /// A bare function (e.g. `fn(usize) -> bool`)
1550 BareFn(P<BareFnTy>),
1551 /// The never type (`!`)
1553 /// A tuple (`(A, B, C, D,...)`)
1555 /// A path (`module::module::...::Type`), optionally
1556 /// "qualified", e.g. `<Vec<T> as SomeTrait>::SomeType`.
1558 /// Type parameters are stored in the Path itself
1559 Path(Option<QSelf>, Path),
1560 /// A trait object type `Bound1 + Bound2 + Bound3`
1561 /// where `Bound` is a trait or a lifetime.
1562 TraitObject(GenericBounds, TraitObjectSyntax),
1563 /// An `impl Bound1 + Bound2 + Bound3` type
1564 /// where `Bound` is a trait or a lifetime.
1566 /// The `NodeId` exists to prevent lowering from having to
1567 /// generate `NodeId`s on the fly, which would complicate
1568 /// the generation of `existential type` items significantly
1569 ImplTrait(NodeId, GenericBounds),
1570 /// No-op; kept solely so that we can pretty-print faithfully
1574 /// TyKind::Infer means the type should be inferred instead of it having been
1575 /// specified. This can appear anywhere in a type.
1577 /// Inferred type of a `self` or `&self` argument in a method.
1579 // A macro in the type position.
1581 /// Placeholder for a kind that has failed to be defined.
1586 pub fn is_implicit_self(&self) -> bool {
1587 if let TyKind::ImplicitSelf = *self { true } else { false }
1590 crate fn is_unit(&self) -> bool {
1591 if let TyKind::Tup(ref tys) = *self { tys.is_empty() } else { false }
1595 /// Syntax used to declare a trait object.
1596 #[derive(Clone, Copy, PartialEq, RustcEncodable, RustcDecodable, Debug)]
1597 pub enum TraitObjectSyntax {
1602 /// Inline assembly dialect.
1604 /// E.g. `"intel"` as in `asm!("mov eax, 2" : "={eax}"(result) : : : "intel")`
1605 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
1606 pub enum AsmDialect {
1611 /// Inline assembly.
1613 /// E.g. `"={eax}"(result)` as in `asm!("mov eax, 2" : "={eax}"(result) : : : "intel")`
1614 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1615 pub struct InlineAsmOutput {
1616 pub constraint: Symbol,
1619 pub is_indirect: bool,
1622 /// Inline assembly.
1624 /// E.g. `asm!("NOP");`
1625 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1626 pub struct InlineAsm {
1628 pub asm_str_style: StrStyle,
1629 pub outputs: Vec<InlineAsmOutput>,
1630 pub inputs: Vec<(Symbol, P<Expr>)>,
1631 pub clobbers: Vec<Symbol>,
1633 pub alignstack: bool,
1634 pub dialect: AsmDialect,
1635 pub ctxt: SyntaxContext,
1638 /// An argument in a function header.
1640 /// E.g. `bar: usize` as in `fn foo(bar: usize)`
1641 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1648 /// Alternative representation for `Arg`s describing `self` parameter of methods.
1650 /// E.g. `&mut self` as in `fn foo(&mut self)`
1651 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1653 /// `self`, `mut self`
1655 /// `&'lt self`, `&'lt mut self`
1656 Region(Option<Lifetime>, Mutability),
1657 /// `self: TYPE`, `mut self: TYPE`
1658 Explicit(P<Ty>, Mutability),
1661 pub type ExplicitSelf = Spanned<SelfKind>;
1664 pub fn to_self(&self) -> Option<ExplicitSelf> {
1665 if let PatKind::Ident(BindingMode::ByValue(mutbl), ident, _) = self.pat.node {
1666 if ident.name == keywords::SelfValue.name() {
1667 return match self.ty.node {
1668 TyKind::ImplicitSelf => Some(respan(self.pat.span, SelfKind::Value(mutbl))),
1669 TyKind::Rptr(lt, MutTy{ref ty, mutbl}) if ty.node.is_implicit_self() => {
1670 Some(respan(self.pat.span, SelfKind::Region(lt, mutbl)))
1672 _ => Some(respan(self.pat.span.to(self.ty.span),
1673 SelfKind::Explicit(self.ty.clone(), mutbl))),
1680 pub fn is_self(&self) -> bool {
1681 if let PatKind::Ident(_, ident, _) = self.pat.node {
1682 ident.name == keywords::SelfValue.name()
1688 pub fn from_self(eself: ExplicitSelf, eself_ident: Ident) -> Arg {
1689 let span = eself.span.to(eself_ident.span);
1690 let infer_ty = P(Ty {
1692 node: TyKind::ImplicitSelf,
1695 let arg = |mutbl, ty| Arg {
1698 node: PatKind::Ident(BindingMode::ByValue(mutbl), eself_ident, None),
1705 SelfKind::Explicit(ty, mutbl) => arg(mutbl, ty),
1706 SelfKind::Value(mutbl) => arg(mutbl, infer_ty),
1707 SelfKind::Region(lt, mutbl) => arg(Mutability::Immutable, P(Ty {
1709 node: TyKind::Rptr(lt, MutTy { ty: infer_ty, mutbl: mutbl }),
1716 /// Header (not the body) of a function declaration.
1718 /// E.g. `fn foo(bar: baz)`
1719 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1721 pub inputs: Vec<Arg>,
1722 pub output: FunctionRetTy,
1727 pub fn get_self(&self) -> Option<ExplicitSelf> {
1728 self.inputs.get(0).and_then(Arg::to_self)
1730 pub fn has_self(&self) -> bool {
1731 self.inputs.get(0).map(Arg::is_self).unwrap_or(false)
1735 /// Is the trait definition an auto trait?
1736 #[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
1742 #[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
1748 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug)]
1752 return_impl_trait_id: NodeId,
1758 pub fn is_async(self) -> bool {
1759 if let IsAsync::Async { .. } = self {
1765 /// In case this is an `Async` return the `NodeId` for the generated impl Trait item
1766 pub fn opt_return_id(self) -> Option<NodeId> {
1768 IsAsync::Async { return_impl_trait_id, .. } => Some(return_impl_trait_id),
1769 IsAsync::NotAsync => None,
1774 #[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
1775 pub enum Constness {
1780 #[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
1781 pub enum Defaultness {
1786 impl fmt::Display for Unsafety {
1787 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1788 fmt::Display::fmt(match *self {
1789 Unsafety::Normal => "normal",
1790 Unsafety::Unsafe => "unsafe",
1795 #[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable)]
1796 pub enum ImplPolarity {
1797 /// `impl Trait for Type`
1799 /// `impl !Trait for Type`
1803 impl fmt::Debug for ImplPolarity {
1804 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1806 ImplPolarity::Positive => "positive".fmt(f),
1807 ImplPolarity::Negative => "negative".fmt(f),
1813 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1814 pub enum FunctionRetTy {
1815 /// Return type is not specified.
1817 /// Functions default to `()` and
1818 /// closures default to inference. Span points to where return
1819 /// type would be inserted.
1825 impl FunctionRetTy {
1826 pub fn span(&self) -> Span {
1828 FunctionRetTy::Default(span) => span,
1829 FunctionRetTy::Ty(ref ty) => ty.span,
1834 /// Module declaration.
1836 /// E.g. `mod foo;` or `mod foo { .. }`
1837 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1839 /// A span from the first token past `{` to the last token until `}`.
1840 /// For `mod foo;`, the inner span ranges from the first token
1841 /// to the last token in the external file.
1843 pub items: Vec<P<Item>>,
1846 /// Foreign module declaration.
1848 /// E.g. `extern { .. }` or `extern C { .. }`
1849 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1850 pub struct ForeignMod {
1852 pub items: Vec<ForeignItem>,
1855 /// Global inline assembly
1857 /// aka module-level assembly or file-scoped assembly
1858 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy)]
1859 pub struct GlobalAsm {
1861 pub ctxt: SyntaxContext,
1864 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1865 pub struct EnumDef {
1866 pub variants: Vec<Variant>,
1869 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1870 pub struct Variant_ {
1872 pub attrs: Vec<Attribute>,
1873 pub data: VariantData,
1874 /// Explicit discriminant, e.g. `Foo = 1`
1875 pub disr_expr: Option<AnonConst>,
1878 pub type Variant = Spanned<Variant_>;
1880 /// Part of `use` item to the right of its prefix.
1881 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1882 pub enum UseTreeKind {
1883 /// `use prefix` or `use prefix as rename`
1885 /// The extra `NodeId`s are for HIR lowering, when additional statements are created for each
1887 Simple(Option<Ident>, NodeId, NodeId),
1888 /// `use prefix::{...}`
1889 Nested(Vec<(UseTree, NodeId)>),
1894 /// A tree of paths sharing common prefixes.
1895 /// Used in `use` items both at top-level and inside of braces in import groups.
1896 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1897 pub struct UseTree {
1899 pub kind: UseTreeKind,
1904 pub fn ident(&self) -> Ident {
1906 UseTreeKind::Simple(Some(rename), ..) => rename,
1907 UseTreeKind::Simple(None, ..) =>
1908 self.prefix.segments.last().expect("empty prefix in a simple import").ident,
1909 _ => panic!("`UseTree::ident` can only be used on a simple import"),
1914 /// Distinguishes between Attributes that decorate items and Attributes that
1915 /// are contained as statements within items. These two cases need to be
1916 /// distinguished for pretty-printing.
1917 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
1918 pub enum AttrStyle {
1923 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, PartialOrd, Ord, Copy)]
1924 pub struct AttrId(pub usize);
1926 impl Idx for AttrId {
1927 fn new(idx: usize) -> Self {
1930 fn index(self) -> usize {
1935 /// Meta-data associated with an item
1936 /// Doc-comments are promoted to attributes that have is_sugared_doc = true
1937 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1938 pub struct Attribute {
1940 pub style: AttrStyle,
1942 pub tokens: TokenStream,
1943 pub is_sugared_doc: bool,
1947 /// TraitRef's appear in impls.
1949 /// resolve maps each TraitRef's ref_id to its defining trait; that's all
1950 /// that the ref_id is for. The impl_id maps to the "self type" of this impl.
1951 /// If this impl is an ItemKind::Impl, the impl_id is redundant (it could be the
1952 /// same as the impl's node id).
1953 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1954 pub struct TraitRef {
1959 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1960 pub struct PolyTraitRef {
1961 /// The `'a` in `<'a> Foo<&'a T>`
1962 pub bound_generic_params: Vec<GenericParam>,
1964 /// The `Foo<&'a T>` in `<'a> Foo<&'a T>`
1965 pub trait_ref: TraitRef,
1971 pub fn new(generic_params: Vec<GenericParam>, path: Path, span: Span) -> Self {
1973 bound_generic_params: generic_params,
1974 trait_ref: TraitRef { path: path, ref_id: DUMMY_NODE_ID },
1980 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug)]
1981 pub enum CrateSugar {
1982 /// Source is `pub(crate)`
1985 /// Source is (just) `crate`
1989 pub type Visibility = Spanned<VisibilityKind>;
1991 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1992 pub enum VisibilityKind {
1995 Restricted { path: P<Path>, id: NodeId },
1999 impl VisibilityKind {
2000 pub fn is_pub(&self) -> bool {
2001 if let VisibilityKind::Public = *self { true } else { false }
2005 /// Field of a struct.
2007 /// E.g. `bar: usize` as in `struct Foo { bar: usize }`
2008 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
2009 pub struct StructField {
2011 pub ident: Option<Ident>,
2012 pub vis: Visibility,
2015 pub attrs: Vec<Attribute>,
2018 /// Fields and Ids of enum variants and structs
2020 /// For enum variants: `NodeId` represents both an Id of the variant itself (relevant for all
2021 /// variant kinds) and an Id of the variant's constructor (not relevant for `Struct`-variants).
2022 /// One shared Id can be successfully used for these two purposes.
2023 /// Id of the whole enum lives in `Item`.
2025 /// For structs: `NodeId` represents an Id of the structure's constructor, so it is not actually
2026 /// used for `Struct`-structs (but still presents). Structures don't have an analogue of "Id of
2027 /// the variant itself" from enum variants.
2028 /// Id of the whole struct lives in `Item`.
2029 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
2030 pub enum VariantData {
2033 /// E.g. `Bar { .. }` as in `enum Foo { Bar { .. } }`
2034 Struct(Vec<StructField>, NodeId),
2037 /// E.g. `Bar(..)` as in `enum Foo { Bar(..) }`
2038 Tuple(Vec<StructField>, NodeId),
2041 /// E.g. `Bar = ..` as in `enum Foo { Bar = .. }`
2046 pub fn fields(&self) -> &[StructField] {
2048 VariantData::Struct(ref fields, _) | VariantData::Tuple(ref fields, _) => fields,
2052 pub fn id(&self) -> NodeId {
2054 VariantData::Struct(_, id) | VariantData::Tuple(_, id) | VariantData::Unit(id) => id
2057 pub fn is_struct(&self) -> bool {
2058 if let VariantData::Struct(..) = *self { true } else { false }
2060 pub fn is_tuple(&self) -> bool {
2061 if let VariantData::Tuple(..) = *self { true } else { false }
2063 pub fn is_unit(&self) -> bool {
2064 if let VariantData::Unit(..) = *self { true } else { false }
2070 /// The name might be a dummy name in case of anonymous items
2071 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
2074 pub attrs: Vec<Attribute>,
2077 pub vis: Visibility,
2080 /// Original tokens this item was parsed from. This isn't necessarily
2081 /// available for all items, although over time more and more items should
2082 /// have this be `Some`. Right now this is primarily used for procedural
2083 /// macros, notably custom attributes.
2085 /// Note that the tokens here do not include the outer attributes, but will
2086 /// include inner attributes.
2087 pub tokens: Option<TokenStream>,
2090 /// A function header
2092 /// All the information between the visibility & the name of the function is
2093 /// included in this struct (e.g. `async unsafe fn` or `const extern "C" fn`)
2094 #[derive(Clone, Copy, RustcEncodable, RustcDecodable, Debug)]
2095 pub struct FnHeader {
2096 pub unsafety: Unsafety,
2097 pub asyncness: IsAsync,
2098 pub constness: Spanned<Constness>,
2102 impl Default for FnHeader {
2103 fn default() -> FnHeader {
2105 unsafety: Unsafety::Normal,
2106 asyncness: IsAsync::NotAsync,
2107 constness: dummy_spanned(Constness::NotConst),
2113 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
2115 /// An `extern crate` item, with optional *original* crate name if the crate was renamed.
2117 /// E.g. `extern crate foo` or `extern crate foo_bar as foo`
2118 ExternCrate(Option<Name>),
2119 /// A use declaration (`use` or `pub use`) item.
2121 /// E.g. `use foo;`, `use foo::bar;` or `use foo::bar as FooBar;`
2123 /// A static item (`static` or `pub static`).
2125 /// E.g. `static FOO: i32 = 42;` or `static FOO: &'static str = "bar";`
2126 Static(P<Ty>, Mutability, P<Expr>),
2127 /// A constant item (`const` or `pub const`).
2129 /// E.g. `const FOO: i32 = 42;`
2130 Const(P<Ty>, P<Expr>),
2131 /// A function declaration (`fn` or `pub fn`).
2133 /// E.g. `fn foo(bar: usize) -> usize { .. }`
2134 Fn(P<FnDecl>, FnHeader, Generics, P<Block>),
2135 /// A module declaration (`mod` or `pub mod`).
2137 /// E.g. `mod foo;` or `mod foo { .. }`
2139 /// An external module (`extern` or `pub extern`).
2141 /// E.g. `extern {}` or `extern "C" {}`
2142 ForeignMod(ForeignMod),
2143 /// Module-level inline assembly (from `global_asm!()`)
2144 GlobalAsm(P<GlobalAsm>),
2145 /// A type alias (`type` or `pub type`).
2147 /// E.g. `type Foo = Bar<u8>;`
2148 Ty(P<Ty>, Generics),
2149 /// An existential type declaration (`existential type`).
2151 /// E.g. `existential type Foo: Bar + Boo;`
2152 Existential(GenericBounds, Generics),
2153 /// An enum definition (`enum` or `pub enum`).
2155 /// E.g. `enum Foo<A, B> { C<A>, D<B> }`
2156 Enum(EnumDef, Generics),
2157 /// A struct definition (`struct` or `pub struct`).
2159 /// E.g. `struct Foo<A> { x: A }`
2160 Struct(VariantData, Generics),
2161 /// A union definition (`union` or `pub union`).
2163 /// E.g. `union Foo<A, B> { x: A, y: B }`
2164 Union(VariantData, Generics),
2165 /// A Trait declaration (`trait` or `pub trait`).
2167 /// E.g. `trait Foo { .. }`, `trait Foo<T> { .. }` or `auto trait Foo {}`
2168 Trait(IsAuto, Unsafety, Generics, GenericBounds, Vec<TraitItem>),
2171 /// E.g. `trait Foo = Bar + Quux;`
2172 TraitAlias(Generics, GenericBounds),
2173 /// An implementation.
2175 /// E.g. `impl<A> Foo<A> { .. }` or `impl<A> Trait for Foo<A> { .. }`
2180 Option<TraitRef>, // (optional) trait this impl implements
2183 /// A macro invocation.
2185 /// E.g. `macro_rules! foo { .. }` or `foo!(..)`
2188 /// A macro definition.
2193 pub fn descriptive_variant(&self) -> &str {
2195 ItemKind::ExternCrate(..) => "extern crate",
2196 ItemKind::Use(..) => "use",
2197 ItemKind::Static(..) => "static item",
2198 ItemKind::Const(..) => "constant item",
2199 ItemKind::Fn(..) => "function",
2200 ItemKind::Mod(..) => "module",
2201 ItemKind::ForeignMod(..) => "foreign module",
2202 ItemKind::GlobalAsm(..) => "global asm",
2203 ItemKind::Ty(..) => "type alias",
2204 ItemKind::Existential(..) => "existential type",
2205 ItemKind::Enum(..) => "enum",
2206 ItemKind::Struct(..) => "struct",
2207 ItemKind::Union(..) => "union",
2208 ItemKind::Trait(..) => "trait",
2209 ItemKind::TraitAlias(..) => "trait alias",
2211 ItemKind::MacroDef(..) |
2212 ItemKind::Impl(..) => "item"
2217 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
2218 pub struct ForeignItem {
2220 pub attrs: Vec<Attribute>,
2221 pub node: ForeignItemKind,
2224 pub vis: Visibility,
2227 /// An item within an `extern` block
2228 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
2229 pub enum ForeignItemKind {
2230 /// A foreign function
2231 Fn(P<FnDecl>, Generics),
2232 /// A foreign static item (`static ext: u8`), with optional mutability
2233 /// (the boolean is true when mutable)
2234 Static(P<Ty>, bool),
2237 /// A macro invocation
2241 impl ForeignItemKind {
2242 pub fn descriptive_variant(&self) -> &str {
2244 ForeignItemKind::Fn(..) => "foreign function",
2245 ForeignItemKind::Static(..) => "foreign static item",
2246 ForeignItemKind::Ty => "foreign type",
2247 ForeignItemKind::Macro(..) => "macro in foreign module",
2257 // are ASTs encodable?
2259 fn check_asts_encodable() {
2260 fn assert_encodable<T: serialize::Encodable>() {}
2261 assert_encodable::<Crate>();