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<P<Expr>>,
864 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
869 pub is_shorthand: bool,
870 pub attrs: ThinVec<Attribute>,
873 pub type SpannedIdent = Spanned<Ident>;
875 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy)]
876 pub enum BlockCheckMode {
878 Unsafe(UnsafeSource),
881 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy)]
882 pub enum UnsafeSource {
887 /// A constant (expression) that's not an item or associated item,
888 /// but needs its own `DefId` for type-checking, const-eval, etc.
889 /// These are usually found nested inside types (e.g. array lengths)
890 /// or expressions (e.g. repeat counts), and also used to define
891 /// explicit discriminant values for enum variants.
892 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
893 pub struct AnonConst {
900 #[derive(Clone, RustcEncodable, RustcDecodable)]
905 pub attrs: ThinVec<Attribute>
909 /// Whether this expression would be valid somewhere that expects a value, for example, an `if`
911 pub fn returns(&self) -> bool {
912 if let ExprKind::Block(ref block, _) = self.node {
913 match block.stmts.last().map(|last_stmt| &last_stmt.node) {
915 Some(&StmtKind::Expr(_)) => true,
916 Some(&StmtKind::Semi(ref expr)) => {
917 if let ExprKind::Ret(_) = expr.node {
918 // last statement is explicit return
924 // This is a block that doesn't end in either an implicit or explicit return
928 // This is not a block, it is a value
933 fn to_bound(&self) -> Option<GenericBound> {
935 ExprKind::Path(None, path) =>
936 Some(GenericBound::Trait(PolyTraitRef::new(Vec::new(), path.clone(), self.span),
937 TraitBoundModifier::None)),
942 pub(super) fn to_ty(&self) -> Option<P<Ty>> {
943 let node = match &self.node {
944 ExprKind::Path(qself, path) => TyKind::Path(qself.clone(), path.clone()),
945 ExprKind::Mac(mac) => TyKind::Mac(mac.clone()),
946 ExprKind::Paren(expr) => expr.to_ty().map(TyKind::Paren)?,
947 ExprKind::AddrOf(mutbl, expr) =>
948 expr.to_ty().map(|ty| TyKind::Rptr(None, MutTy { ty, mutbl: *mutbl }))?,
949 ExprKind::Repeat(expr, expr_len) =>
950 expr.to_ty().map(|ty| TyKind::Array(ty, expr_len.clone()))?,
951 ExprKind::Array(exprs) if exprs.len() == 1 =>
952 exprs[0].to_ty().map(TyKind::Slice)?,
953 ExprKind::Tup(exprs) => {
954 let tys = exprs.iter().map(|expr| expr.to_ty()).collect::<Option<Vec<_>>>()?;
957 ExprKind::Binary(binop, lhs, rhs) if binop.node == BinOpKind::Add =>
958 if let (Some(lhs), Some(rhs)) = (lhs.to_bound(), rhs.to_bound()) {
959 TyKind::TraitObject(vec![lhs, rhs], TraitObjectSyntax::None)
966 Some(P(Ty { node, id: self.id, span: self.span }))
969 pub fn precedence(&self) -> ExprPrecedence {
971 ExprKind::Box(_) => ExprPrecedence::Box,
972 ExprKind::ObsoleteInPlace(..) => ExprPrecedence::ObsoleteInPlace,
973 ExprKind::Array(_) => ExprPrecedence::Array,
974 ExprKind::Call(..) => ExprPrecedence::Call,
975 ExprKind::MethodCall(..) => ExprPrecedence::MethodCall,
976 ExprKind::Tup(_) => ExprPrecedence::Tup,
977 ExprKind::Binary(op, ..) => ExprPrecedence::Binary(op.node),
978 ExprKind::Unary(..) => ExprPrecedence::Unary,
979 ExprKind::Lit(_) => ExprPrecedence::Lit,
980 ExprKind::Type(..) | ExprKind::Cast(..) => ExprPrecedence::Cast,
981 ExprKind::If(..) => ExprPrecedence::If,
982 ExprKind::IfLet(..) => ExprPrecedence::IfLet,
983 ExprKind::While(..) => ExprPrecedence::While,
984 ExprKind::WhileLet(..) => ExprPrecedence::WhileLet,
985 ExprKind::ForLoop(..) => ExprPrecedence::ForLoop,
986 ExprKind::Loop(..) => ExprPrecedence::Loop,
987 ExprKind::Match(..) => ExprPrecedence::Match,
988 ExprKind::Closure(..) => ExprPrecedence::Closure,
989 ExprKind::Block(..) => ExprPrecedence::Block,
990 ExprKind::TryBlock(..) => ExprPrecedence::TryBlock,
991 ExprKind::Async(..) => ExprPrecedence::Async,
992 ExprKind::Assign(..) => ExprPrecedence::Assign,
993 ExprKind::AssignOp(..) => ExprPrecedence::AssignOp,
994 ExprKind::Field(..) => ExprPrecedence::Field,
995 ExprKind::Index(..) => ExprPrecedence::Index,
996 ExprKind::Range(..) => ExprPrecedence::Range,
997 ExprKind::Path(..) => ExprPrecedence::Path,
998 ExprKind::AddrOf(..) => ExprPrecedence::AddrOf,
999 ExprKind::Break(..) => ExprPrecedence::Break,
1000 ExprKind::Continue(..) => ExprPrecedence::Continue,
1001 ExprKind::Ret(..) => ExprPrecedence::Ret,
1002 ExprKind::InlineAsm(..) => ExprPrecedence::InlineAsm,
1003 ExprKind::Mac(..) => ExprPrecedence::Mac,
1004 ExprKind::Struct(..) => ExprPrecedence::Struct,
1005 ExprKind::Repeat(..) => ExprPrecedence::Repeat,
1006 ExprKind::Paren(..) => ExprPrecedence::Paren,
1007 ExprKind::Try(..) => ExprPrecedence::Try,
1008 ExprKind::Yield(..) => ExprPrecedence::Yield,
1013 impl fmt::Debug for Expr {
1014 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1015 write!(f, "expr({}: {})", self.id, pprust::expr_to_string(self))
1019 /// Limit types of a range (inclusive or exclusive)
1020 #[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
1021 pub enum RangeLimits {
1022 /// Inclusive at the beginning, exclusive at the end
1024 /// Inclusive at the beginning and end
1028 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1030 /// A `box x` expression.
1032 /// First expr is the place; second expr is the value.
1033 ObsoleteInPlace(P<Expr>, P<Expr>),
1034 /// An array (`[a, b, c, d]`)
1035 Array(Vec<P<Expr>>),
1038 /// The first field resolves to the function itself,
1039 /// and the second field is the list of arguments.
1040 /// This also represents calling the constructor of
1041 /// tuple-like ADTs such as tuple structs and enum variants.
1042 Call(P<Expr>, Vec<P<Expr>>),
1043 /// A method call (`x.foo::<'static, Bar, Baz>(a, b, c, d)`)
1045 /// The `PathSegment` represents the method name and its generic arguments
1046 /// (within the angle brackets).
1047 /// The first element of the vector of `Expr`s is the expression that evaluates
1048 /// to the object on which the method is being called on (the receiver),
1049 /// and the remaining elements are the rest of the arguments.
1050 /// Thus, `x.foo::<Bar, Baz>(a, b, c, d)` is represented as
1051 /// `ExprKind::MethodCall(PathSegment { foo, [Bar, Baz] }, [x, a, b, c, d])`.
1052 MethodCall(PathSegment, Vec<P<Expr>>),
1053 /// A tuple (`(a, b, c ,d)`)
1055 /// A binary operation (For example: `a + b`, `a * b`)
1056 Binary(BinOp, P<Expr>, P<Expr>),
1057 /// A unary operation (For example: `!x`, `*x`)
1058 Unary(UnOp, P<Expr>),
1059 /// A literal (For example: `1`, `"foo"`)
1061 /// A cast (`foo as f64`)
1062 Cast(P<Expr>, P<Ty>),
1063 Type(P<Expr>, P<Ty>),
1064 /// An `if` block, with an optional else block
1066 /// `if expr { block } else { expr }`
1067 If(P<Expr>, P<Block>, Option<P<Expr>>),
1068 /// An `if let` expression with an optional else block
1070 /// `if let pat = expr { block } else { expr }`
1072 /// This is desugared to a `match` expression.
1073 IfLet(Vec<P<Pat>>, P<Expr>, P<Block>, Option<P<Expr>>),
1074 /// A while loop, with an optional label
1076 /// `'label: while expr { block }`
1077 While(P<Expr>, P<Block>, Option<Label>),
1078 /// A while-let loop, with an optional label
1080 /// `'label: while let pat = expr { block }`
1082 /// This is desugared to a combination of `loop` and `match` expressions.
1083 WhileLet(Vec<P<Pat>>, P<Expr>, P<Block>, Option<Label>),
1084 /// A for loop, with an optional label
1086 /// `'label: for pat in expr { block }`
1088 /// This is desugared to a combination of `loop` and `match` expressions.
1089 ForLoop(P<Pat>, P<Expr>, P<Block>, Option<Label>),
1090 /// Conditionless loop (can be exited with break, continue, or return)
1092 /// `'label: loop { block }`
1093 Loop(P<Block>, Option<Label>),
1094 /// A `match` block.
1095 Match(P<Expr>, Vec<Arm>),
1096 /// A closure (for example, `move |a, b, c| a + b + c`)
1098 /// The final span is the span of the argument block `|...|`
1099 Closure(CaptureBy, IsAsync, Movability, P<FnDecl>, P<Expr>, Span),
1100 /// A block (`'label: { ... }`)
1101 Block(P<Block>, Option<Label>),
1102 /// An async block (`async move { ... }`)
1104 /// The `NodeId` is the `NodeId` for the closure that results from
1105 /// desugaring an async block, just like the NodeId field in the
1106 /// `IsAsync` enum. This is necessary in order to create a def for the
1107 /// closure which can be used as a parent of any child defs. Defs
1108 /// created during lowering cannot be made the parent of any other
1109 /// preexisting defs.
1110 Async(CaptureBy, NodeId, P<Block>),
1111 /// A try block (`try { ... }`)
1114 /// An assignment (`a = foo()`)
1115 Assign(P<Expr>, P<Expr>),
1116 /// An assignment with an operator
1118 /// For example, `a += 1`.
1119 AssignOp(BinOp, P<Expr>, P<Expr>),
1120 /// Access of a named (`obj.foo`) or unnamed (`obj.0`) struct field
1121 Field(P<Expr>, Ident),
1122 /// An indexing operation (`foo[2]`)
1123 Index(P<Expr>, P<Expr>),
1124 /// A range (`1..2`, `1..`, `..2`, `1...2`, `1...`, `...2`)
1125 Range(Option<P<Expr>>, Option<P<Expr>>, RangeLimits),
1127 /// Variable reference, possibly containing `::` and/or type
1128 /// parameters, e.g. foo::bar::<baz>.
1130 /// Optionally "qualified",
1131 /// E.g. `<Vec<T> as SomeTrait>::SomeType`.
1132 Path(Option<QSelf>, Path),
1134 /// A referencing operation (`&a` or `&mut a`)
1135 AddrOf(Mutability, P<Expr>),
1136 /// A `break`, with an optional label to break, and an optional expression
1137 Break(Option<Label>, Option<P<Expr>>),
1138 /// A `continue`, with an optional label
1139 Continue(Option<Label>),
1140 /// A `return`, with an optional value to be returned
1141 Ret(Option<P<Expr>>),
1143 /// Output of the `asm!()` macro
1144 InlineAsm(P<InlineAsm>),
1146 /// A macro invocation; pre-expansion
1149 /// A struct literal expression.
1151 /// For example, `Foo {x: 1, y: 2}`, or
1152 /// `Foo {x: 1, .. base}`, where `base` is the `Option<Expr>`.
1153 Struct(Path, Vec<Field>, Option<P<Expr>>),
1155 /// An array literal constructed from one repeated element.
1157 /// For example, `[1; 5]`. The expression is the element to be
1158 /// repeated; the constant is the number of times to repeat it.
1159 Repeat(P<Expr>, AnonConst),
1161 /// No-op: used solely so we can pretty-print faithfully
1167 /// A `yield`, with an optional value to be yielded
1168 Yield(Option<P<Expr>>),
1171 /// The explicit Self type in a "qualified path". The actual
1172 /// path, including the trait and the associated item, is stored
1173 /// separately. `position` represents the index of the associated
1174 /// item qualified with this Self type.
1176 /// ```ignore (only-for-syntax-highlight)
1177 /// <Vec<T> as a::b::Trait>::AssociatedItem
1178 /// ^~~~~ ~~~~~~~~~~~~~~^
1181 /// <Vec<T>>::AssociatedItem
1185 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1189 /// The span of `a::b::Trait` in a path like `<Vec<T> as
1190 /// a::b::Trait>::AssociatedItem`; in the case where `position ==
1191 /// 0`, this is an empty span.
1192 pub path_span: Span,
1196 /// A capture clause
1197 #[derive(Clone, Copy, PartialEq, RustcEncodable, RustcDecodable, Debug)]
1198 pub enum CaptureBy {
1203 /// The movability of a generator / closure literal
1204 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
1205 pub enum Movability {
1210 pub type Mac = Spanned<Mac_>;
1212 /// Represents a macro invocation. The Path indicates which macro
1213 /// is being invoked, and the vector of token-trees contains the source
1214 /// of the macro invocation.
1216 /// NB: the additional ident for a macro_rules-style macro is actually
1217 /// stored in the enclosing item. Oog.
1218 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1221 pub delim: MacDelimiter,
1222 pub tts: ThinTokenStream,
1225 #[derive(Copy, Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Debug)]
1226 pub enum MacDelimiter {
1233 pub fn stream(&self) -> TokenStream {
1234 self.tts.clone().into()
1238 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1239 pub struct MacroDef {
1240 pub tokens: ThinTokenStream,
1245 pub fn stream(&self) -> TokenStream {
1246 self.tokens.clone().into()
1250 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy, Hash, PartialEq)]
1252 /// A regular string, like `"foo"`
1254 /// A raw string, like `r##"foo"##`
1256 /// The value is the number of `#` symbols used.
1261 pub type Lit = Spanned<LitKind>;
1263 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy, Hash, PartialEq)]
1264 pub enum LitIntType {
1272 /// E.g. `"foo"`, `42`, `12.34` or `bool`
1273 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Hash, PartialEq)]
1275 /// A string literal (`"foo"`)
1276 Str(Symbol, StrStyle),
1277 /// A byte string (`b"foo"`)
1278 ByteStr(Lrc<Vec<u8>>),
1279 /// A byte char (`b'f'`)
1281 /// A character literal (`'a'`)
1283 /// An integer literal (`1`)
1284 Int(u128, LitIntType),
1285 /// A float literal (`1f64` or `1E10f64`)
1286 Float(Symbol, FloatTy),
1287 /// A float literal without a suffix (`1.0 or 1.0E10`)
1288 FloatUnsuffixed(Symbol),
1289 /// A boolean literal
1294 /// Returns true if this literal is a string and false otherwise.
1295 pub fn is_str(&self) -> bool {
1297 LitKind::Str(..) => true,
1302 /// Returns true if this is a numeric literal.
1303 pub fn is_numeric(&self) -> bool {
1306 LitKind::Float(..) |
1307 LitKind::FloatUnsuffixed(..) => true,
1312 /// Returns true if this literal has no suffix. Note: this will return true
1313 /// for literals with prefixes such as raw strings and byte strings.
1314 pub fn is_unsuffixed(&self) -> bool {
1316 // unsuffixed variants
1318 LitKind::ByteStr(..) |
1321 LitKind::Int(_, LitIntType::Unsuffixed) |
1322 LitKind::FloatUnsuffixed(..) |
1323 LitKind::Bool(..) => true,
1324 // suffixed variants
1325 LitKind::Int(_, LitIntType::Signed(..)) |
1326 LitKind::Int(_, LitIntType::Unsigned(..)) |
1327 LitKind::Float(..) => false,
1331 /// Returns true if this literal has a suffix.
1332 pub fn is_suffixed(&self) -> bool {
1333 !self.is_unsuffixed()
1337 // NB: If you change this, you'll probably want to change the corresponding
1338 // type structure in middle/ty.rs as well.
1339 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1342 pub mutbl: Mutability,
1345 /// Represents a method's signature in a trait declaration,
1346 /// or in an implementation.
1347 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1348 pub struct MethodSig {
1349 pub header: FnHeader,
1350 pub decl: P<FnDecl>,
1353 /// Represents an item declaration within a trait declaration,
1354 /// possibly including a default implementation. A trait item is
1355 /// either required (meaning it doesn't have an implementation, just a
1356 /// signature) or provided (meaning it has a default implementation).
1357 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1358 pub struct TraitItem {
1361 pub attrs: Vec<Attribute>,
1362 pub generics: Generics,
1363 pub node: TraitItemKind,
1365 /// See `Item::tokens` for what this is
1366 pub tokens: Option<TokenStream>,
1369 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1370 pub enum TraitItemKind {
1371 Const(P<Ty>, Option<P<Expr>>),
1372 Method(MethodSig, Option<P<Block>>),
1373 Type(GenericBounds, Option<P<Ty>>),
1377 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1378 pub struct ImplItem {
1381 pub vis: Visibility,
1382 pub defaultness: Defaultness,
1383 pub attrs: Vec<Attribute>,
1384 pub generics: Generics,
1385 pub node: ImplItemKind,
1387 /// See `Item::tokens` for what this is
1388 pub tokens: Option<TokenStream>,
1391 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1392 pub enum ImplItemKind {
1393 Const(P<Ty>, P<Expr>),
1394 Method(MethodSig, P<Block>),
1396 Existential(GenericBounds),
1400 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable, Copy)]
1410 impl fmt::Debug for IntTy {
1411 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1412 fmt::Display::fmt(self, f)
1416 impl fmt::Display for IntTy {
1417 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1418 write!(f, "{}", self.ty_to_string())
1423 pub fn ty_to_string(&self) -> &'static str {
1425 IntTy::Isize => "isize",
1427 IntTy::I16 => "i16",
1428 IntTy::I32 => "i32",
1429 IntTy::I64 => "i64",
1430 IntTy::I128 => "i128",
1434 pub fn val_to_string(&self, val: i128) -> String {
1435 // cast to a u128 so we can correctly print INT128_MIN. All integral types
1436 // are parsed as u128, so we wouldn't want to print an extra negative
1438 format!("{}{}", val as u128, self.ty_to_string())
1441 pub fn bit_width(&self) -> Option<usize> {
1443 IntTy::Isize => return None,
1453 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable, Copy)]
1464 pub fn ty_to_string(&self) -> &'static str {
1466 UintTy::Usize => "usize",
1468 UintTy::U16 => "u16",
1469 UintTy::U32 => "u32",
1470 UintTy::U64 => "u64",
1471 UintTy::U128 => "u128",
1475 pub fn val_to_string(&self, val: u128) -> String {
1476 format!("{}{}", val, self.ty_to_string())
1479 pub fn bit_width(&self) -> Option<usize> {
1481 UintTy::Usize => return None,
1486 UintTy::U128 => 128,
1491 impl fmt::Debug for UintTy {
1492 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1493 fmt::Display::fmt(self, f)
1497 impl fmt::Display for UintTy {
1498 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1499 write!(f, "{}", self.ty_to_string())
1503 // Bind a type to an associated type: `A=Foo`.
1504 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1505 pub struct TypeBinding {
1512 #[derive(Clone, RustcEncodable, RustcDecodable)]
1519 impl fmt::Debug for Ty {
1520 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1521 write!(f, "type({})", pprust::ty_to_string(self))
1525 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1526 pub struct BareFnTy {
1527 pub unsafety: Unsafety,
1529 pub generic_params: Vec<GenericParam>,
1533 /// The different kinds of types recognized by the compiler
1534 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1536 /// A variable-length slice (`[T]`)
1538 /// A fixed length array (`[T; n]`)
1539 Array(P<Ty>, AnonConst),
1540 /// A raw pointer (`*const T` or `*mut T`)
1542 /// A reference (`&'a T` or `&'a mut T`)
1543 Rptr(Option<Lifetime>, MutTy),
1544 /// A bare function (e.g. `fn(usize) -> bool`)
1545 BareFn(P<BareFnTy>),
1546 /// The never type (`!`)
1548 /// A tuple (`(A, B, C, D,...)`)
1550 /// A path (`module::module::...::Type`), optionally
1551 /// "qualified", e.g. `<Vec<T> as SomeTrait>::SomeType`.
1553 /// Type parameters are stored in the Path itself
1554 Path(Option<QSelf>, Path),
1555 /// A trait object type `Bound1 + Bound2 + Bound3`
1556 /// where `Bound` is a trait or a lifetime.
1557 TraitObject(GenericBounds, TraitObjectSyntax),
1558 /// An `impl Bound1 + Bound2 + Bound3` type
1559 /// where `Bound` is a trait or a lifetime.
1561 /// The `NodeId` exists to prevent lowering from having to
1562 /// generate `NodeId`s on the fly, which would complicate
1563 /// the generation of `existential type` items significantly
1564 ImplTrait(NodeId, GenericBounds),
1565 /// No-op; kept solely so that we can pretty-print faithfully
1569 /// TyKind::Infer means the type should be inferred instead of it having been
1570 /// specified. This can appear anywhere in a type.
1572 /// Inferred type of a `self` or `&self` argument in a method.
1574 // A macro in the type position.
1576 /// Placeholder for a kind that has failed to be defined.
1581 pub fn is_implicit_self(&self) -> bool {
1582 if let TyKind::ImplicitSelf = *self { true } else { false }
1585 crate fn is_unit(&self) -> bool {
1586 if let TyKind::Tup(ref tys) = *self { tys.is_empty() } else { false }
1590 /// Syntax used to declare a trait object.
1591 #[derive(Clone, Copy, PartialEq, RustcEncodable, RustcDecodable, Debug)]
1592 pub enum TraitObjectSyntax {
1597 /// Inline assembly dialect.
1599 /// E.g. `"intel"` as in `asm!("mov eax, 2" : "={eax}"(result) : : : "intel")`
1600 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
1601 pub enum AsmDialect {
1606 /// Inline assembly.
1608 /// E.g. `"={eax}"(result)` as in `asm!("mov eax, 2" : "={eax}"(result) : : : "intel")`
1609 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1610 pub struct InlineAsmOutput {
1611 pub constraint: Symbol,
1614 pub is_indirect: bool,
1617 /// Inline assembly.
1619 /// E.g. `asm!("NOP");`
1620 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1621 pub struct InlineAsm {
1623 pub asm_str_style: StrStyle,
1624 pub outputs: Vec<InlineAsmOutput>,
1625 pub inputs: Vec<(Symbol, P<Expr>)>,
1626 pub clobbers: Vec<Symbol>,
1628 pub alignstack: bool,
1629 pub dialect: AsmDialect,
1630 pub ctxt: SyntaxContext,
1633 /// An argument in a function header.
1635 /// E.g. `bar: usize` as in `fn foo(bar: usize)`
1636 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1643 /// Alternative representation for `Arg`s describing `self` parameter of methods.
1645 /// E.g. `&mut self` as in `fn foo(&mut self)`
1646 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1648 /// `self`, `mut self`
1650 /// `&'lt self`, `&'lt mut self`
1651 Region(Option<Lifetime>, Mutability),
1652 /// `self: TYPE`, `mut self: TYPE`
1653 Explicit(P<Ty>, Mutability),
1656 pub type ExplicitSelf = Spanned<SelfKind>;
1659 pub fn to_self(&self) -> Option<ExplicitSelf> {
1660 if let PatKind::Ident(BindingMode::ByValue(mutbl), ident, _) = self.pat.node {
1661 if ident.name == keywords::SelfValue.name() {
1662 return match self.ty.node {
1663 TyKind::ImplicitSelf => Some(respan(self.pat.span, SelfKind::Value(mutbl))),
1664 TyKind::Rptr(lt, MutTy{ref ty, mutbl}) if ty.node.is_implicit_self() => {
1665 Some(respan(self.pat.span, SelfKind::Region(lt, mutbl)))
1667 _ => Some(respan(self.pat.span.to(self.ty.span),
1668 SelfKind::Explicit(self.ty.clone(), mutbl))),
1675 pub fn is_self(&self) -> bool {
1676 if let PatKind::Ident(_, ident, _) = self.pat.node {
1677 ident.name == keywords::SelfValue.name()
1683 pub fn from_self(eself: ExplicitSelf, eself_ident: Ident) -> Arg {
1684 let span = eself.span.to(eself_ident.span);
1685 let infer_ty = P(Ty {
1687 node: TyKind::ImplicitSelf,
1690 let arg = |mutbl, ty| Arg {
1693 node: PatKind::Ident(BindingMode::ByValue(mutbl), eself_ident, None),
1700 SelfKind::Explicit(ty, mutbl) => arg(mutbl, ty),
1701 SelfKind::Value(mutbl) => arg(mutbl, infer_ty),
1702 SelfKind::Region(lt, mutbl) => arg(Mutability::Immutable, P(Ty {
1704 node: TyKind::Rptr(lt, MutTy { ty: infer_ty, mutbl: mutbl }),
1711 /// Header (not the body) of a function declaration.
1713 /// E.g. `fn foo(bar: baz)`
1714 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1716 pub inputs: Vec<Arg>,
1717 pub output: FunctionRetTy,
1722 pub fn get_self(&self) -> Option<ExplicitSelf> {
1723 self.inputs.get(0).and_then(Arg::to_self)
1725 pub fn has_self(&self) -> bool {
1726 self.inputs.get(0).map(Arg::is_self).unwrap_or(false)
1730 /// Is the trait definition an auto trait?
1731 #[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
1737 #[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
1743 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug)]
1747 return_impl_trait_id: NodeId,
1753 pub fn is_async(self) -> bool {
1754 if let IsAsync::Async { .. } = self {
1760 /// In case this is an `Async` return the `NodeId` for the generated impl Trait item
1761 pub fn opt_return_id(self) -> Option<NodeId> {
1763 IsAsync::Async { return_impl_trait_id, .. } => Some(return_impl_trait_id),
1764 IsAsync::NotAsync => None,
1769 #[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
1770 pub enum Constness {
1775 #[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
1776 pub enum Defaultness {
1781 impl fmt::Display for Unsafety {
1782 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1783 fmt::Display::fmt(match *self {
1784 Unsafety::Normal => "normal",
1785 Unsafety::Unsafe => "unsafe",
1790 #[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable)]
1791 pub enum ImplPolarity {
1792 /// `impl Trait for Type`
1794 /// `impl !Trait for Type`
1798 impl fmt::Debug for ImplPolarity {
1799 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1801 ImplPolarity::Positive => "positive".fmt(f),
1802 ImplPolarity::Negative => "negative".fmt(f),
1808 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1809 pub enum FunctionRetTy {
1810 /// Return type is not specified.
1812 /// Functions default to `()` and
1813 /// closures default to inference. Span points to where return
1814 /// type would be inserted.
1820 impl FunctionRetTy {
1821 pub fn span(&self) -> Span {
1823 FunctionRetTy::Default(span) => span,
1824 FunctionRetTy::Ty(ref ty) => ty.span,
1829 /// Module declaration.
1831 /// E.g. `mod foo;` or `mod foo { .. }`
1832 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1834 /// A span from the first token past `{` to the last token until `}`.
1835 /// For `mod foo;`, the inner span ranges from the first token
1836 /// to the last token in the external file.
1838 pub items: Vec<P<Item>>,
1841 /// Foreign module declaration.
1843 /// E.g. `extern { .. }` or `extern C { .. }`
1844 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1845 pub struct ForeignMod {
1847 pub items: Vec<ForeignItem>,
1850 /// Global inline assembly
1852 /// aka module-level assembly or file-scoped assembly
1853 #[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy)]
1854 pub struct GlobalAsm {
1856 pub ctxt: SyntaxContext,
1859 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1860 pub struct EnumDef {
1861 pub variants: Vec<Variant>,
1864 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1865 pub struct Variant_ {
1867 pub attrs: Vec<Attribute>,
1868 pub data: VariantData,
1869 /// Explicit discriminant, e.g. `Foo = 1`
1870 pub disr_expr: Option<AnonConst>,
1873 pub type Variant = Spanned<Variant_>;
1875 /// Part of `use` item to the right of its prefix.
1876 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1877 pub enum UseTreeKind {
1878 /// `use prefix` or `use prefix as rename`
1880 /// The extra `NodeId`s are for HIR lowering, when additional statements are created for each
1882 Simple(Option<Ident>, NodeId, NodeId),
1883 /// `use prefix::{...}`
1884 Nested(Vec<(UseTree, NodeId)>),
1889 /// A tree of paths sharing common prefixes.
1890 /// Used in `use` items both at top-level and inside of braces in import groups.
1891 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1892 pub struct UseTree {
1894 pub kind: UseTreeKind,
1899 pub fn ident(&self) -> Ident {
1901 UseTreeKind::Simple(Some(rename), ..) => rename,
1902 UseTreeKind::Simple(None, ..) =>
1903 self.prefix.segments.last().expect("empty prefix in a simple import").ident,
1904 _ => panic!("`UseTree::ident` can only be used on a simple import"),
1909 /// Distinguishes between Attributes that decorate items and Attributes that
1910 /// are contained as statements within items. These two cases need to be
1911 /// distinguished for pretty-printing.
1912 #[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
1913 pub enum AttrStyle {
1918 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, PartialOrd, Ord, Copy)]
1919 pub struct AttrId(pub usize);
1921 impl Idx for AttrId {
1922 fn new(idx: usize) -> Self {
1925 fn index(self) -> usize {
1930 /// Meta-data associated with an item
1931 /// Doc-comments are promoted to attributes that have is_sugared_doc = true
1932 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1933 pub struct Attribute {
1935 pub style: AttrStyle,
1937 pub tokens: TokenStream,
1938 pub is_sugared_doc: bool,
1942 /// TraitRef's appear in impls.
1944 /// resolve maps each TraitRef's ref_id to its defining trait; that's all
1945 /// that the ref_id is for. The impl_id maps to the "self type" of this impl.
1946 /// If this impl is an ItemKind::Impl, the impl_id is redundant (it could be the
1947 /// same as the impl's node id).
1948 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1949 pub struct TraitRef {
1954 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1955 pub struct PolyTraitRef {
1956 /// The `'a` in `<'a> Foo<&'a T>`
1957 pub bound_generic_params: Vec<GenericParam>,
1959 /// The `Foo<&'a T>` in `<'a> Foo<&'a T>`
1960 pub trait_ref: TraitRef,
1966 pub fn new(generic_params: Vec<GenericParam>, path: Path, span: Span) -> Self {
1968 bound_generic_params: generic_params,
1969 trait_ref: TraitRef { path: path, ref_id: DUMMY_NODE_ID },
1975 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug)]
1976 pub enum CrateSugar {
1977 /// Source is `pub(crate)`
1980 /// Source is (just) `crate`
1984 pub type Visibility = Spanned<VisibilityKind>;
1986 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
1987 pub enum VisibilityKind {
1990 Restricted { path: P<Path>, id: NodeId },
1994 impl VisibilityKind {
1995 pub fn is_pub(&self) -> bool {
1996 if let VisibilityKind::Public = *self { true } else { false }
2000 /// Field of a struct.
2002 /// E.g. `bar: usize` as in `struct Foo { bar: usize }`
2003 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
2004 pub struct StructField {
2006 pub ident: Option<Ident>,
2007 pub vis: Visibility,
2010 pub attrs: Vec<Attribute>,
2013 /// Fields and Ids of enum variants and structs
2015 /// For enum variants: `NodeId` represents both an Id of the variant itself (relevant for all
2016 /// variant kinds) and an Id of the variant's constructor (not relevant for `Struct`-variants).
2017 /// One shared Id can be successfully used for these two purposes.
2018 /// Id of the whole enum lives in `Item`.
2020 /// For structs: `NodeId` represents an Id of the structure's constructor, so it is not actually
2021 /// used for `Struct`-structs (but still presents). Structures don't have an analogue of "Id of
2022 /// the variant itself" from enum variants.
2023 /// Id of the whole struct lives in `Item`.
2024 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
2025 pub enum VariantData {
2028 /// E.g. `Bar { .. }` as in `enum Foo { Bar { .. } }`
2029 Struct(Vec<StructField>, NodeId),
2032 /// E.g. `Bar(..)` as in `enum Foo { Bar(..) }`
2033 Tuple(Vec<StructField>, NodeId),
2036 /// E.g. `Bar = ..` as in `enum Foo { Bar = .. }`
2041 pub fn fields(&self) -> &[StructField] {
2043 VariantData::Struct(ref fields, _) | VariantData::Tuple(ref fields, _) => fields,
2047 pub fn id(&self) -> NodeId {
2049 VariantData::Struct(_, id) | VariantData::Tuple(_, id) | VariantData::Unit(id) => id
2052 pub fn is_struct(&self) -> bool {
2053 if let VariantData::Struct(..) = *self { true } else { false }
2055 pub fn is_tuple(&self) -> bool {
2056 if let VariantData::Tuple(..) = *self { true } else { false }
2058 pub fn is_unit(&self) -> bool {
2059 if let VariantData::Unit(..) = *self { true } else { false }
2065 /// The name might be a dummy name in case of anonymous items
2066 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
2069 pub attrs: Vec<Attribute>,
2072 pub vis: Visibility,
2075 /// Original tokens this item was parsed from. This isn't necessarily
2076 /// available for all items, although over time more and more items should
2077 /// have this be `Some`. Right now this is primarily used for procedural
2078 /// macros, notably custom attributes.
2080 /// Note that the tokens here do not include the outer attributes, but will
2081 /// include inner attributes.
2082 pub tokens: Option<TokenStream>,
2085 /// A function header
2087 /// All the information between the visibility & the name of the function is
2088 /// included in this struct (e.g. `async unsafe fn` or `const extern "C" fn`)
2089 #[derive(Clone, Copy, RustcEncodable, RustcDecodable, Debug)]
2090 pub struct FnHeader {
2091 pub unsafety: Unsafety,
2092 pub asyncness: IsAsync,
2093 pub constness: Spanned<Constness>,
2097 impl Default for FnHeader {
2098 fn default() -> FnHeader {
2100 unsafety: Unsafety::Normal,
2101 asyncness: IsAsync::NotAsync,
2102 constness: dummy_spanned(Constness::NotConst),
2108 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
2110 /// An `extern crate` item, with optional *original* crate name if the crate was renamed.
2112 /// E.g. `extern crate foo` or `extern crate foo_bar as foo`
2113 ExternCrate(Option<Name>),
2114 /// A use declaration (`use` or `pub use`) item.
2116 /// E.g. `use foo;`, `use foo::bar;` or `use foo::bar as FooBar;`
2118 /// A static item (`static` or `pub static`).
2120 /// E.g. `static FOO: i32 = 42;` or `static FOO: &'static str = "bar";`
2121 Static(P<Ty>, Mutability, P<Expr>),
2122 /// A constant item (`const` or `pub const`).
2124 /// E.g. `const FOO: i32 = 42;`
2125 Const(P<Ty>, P<Expr>),
2126 /// A function declaration (`fn` or `pub fn`).
2128 /// E.g. `fn foo(bar: usize) -> usize { .. }`
2129 Fn(P<FnDecl>, FnHeader, Generics, P<Block>),
2130 /// A module declaration (`mod` or `pub mod`).
2132 /// E.g. `mod foo;` or `mod foo { .. }`
2134 /// An external module (`extern` or `pub extern`).
2136 /// E.g. `extern {}` or `extern "C" {}`
2137 ForeignMod(ForeignMod),
2138 /// Module-level inline assembly (from `global_asm!()`)
2139 GlobalAsm(P<GlobalAsm>),
2140 /// A type alias (`type` or `pub type`).
2142 /// E.g. `type Foo = Bar<u8>;`
2143 Ty(P<Ty>, Generics),
2144 /// An existential type declaration (`existential type`).
2146 /// E.g. `existential type Foo: Bar + Boo;`
2147 Existential(GenericBounds, Generics),
2148 /// An enum definition (`enum` or `pub enum`).
2150 /// E.g. `enum Foo<A, B> { C<A>, D<B> }`
2151 Enum(EnumDef, Generics),
2152 /// A struct definition (`struct` or `pub struct`).
2154 /// E.g. `struct Foo<A> { x: A }`
2155 Struct(VariantData, Generics),
2156 /// A union definition (`union` or `pub union`).
2158 /// E.g. `union Foo<A, B> { x: A, y: B }`
2159 Union(VariantData, Generics),
2160 /// A Trait declaration (`trait` or `pub trait`).
2162 /// E.g. `trait Foo { .. }`, `trait Foo<T> { .. }` or `auto trait Foo {}`
2163 Trait(IsAuto, Unsafety, Generics, GenericBounds, Vec<TraitItem>),
2166 /// E.g. `trait Foo = Bar + Quux;`
2167 TraitAlias(Generics, GenericBounds),
2168 /// An implementation.
2170 /// E.g. `impl<A> Foo<A> { .. }` or `impl<A> Trait for Foo<A> { .. }`
2175 Option<TraitRef>, // (optional) trait this impl implements
2178 /// A macro invocation.
2180 /// E.g. `macro_rules! foo { .. }` or `foo!(..)`
2183 /// A macro definition.
2188 pub fn descriptive_variant(&self) -> &str {
2190 ItemKind::ExternCrate(..) => "extern crate",
2191 ItemKind::Use(..) => "use",
2192 ItemKind::Static(..) => "static item",
2193 ItemKind::Const(..) => "constant item",
2194 ItemKind::Fn(..) => "function",
2195 ItemKind::Mod(..) => "module",
2196 ItemKind::ForeignMod(..) => "foreign module",
2197 ItemKind::GlobalAsm(..) => "global asm",
2198 ItemKind::Ty(..) => "type alias",
2199 ItemKind::Existential(..) => "existential type",
2200 ItemKind::Enum(..) => "enum",
2201 ItemKind::Struct(..) => "struct",
2202 ItemKind::Union(..) => "union",
2203 ItemKind::Trait(..) => "trait",
2204 ItemKind::TraitAlias(..) => "trait alias",
2206 ItemKind::MacroDef(..) |
2207 ItemKind::Impl(..) => "item"
2212 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
2213 pub struct ForeignItem {
2215 pub attrs: Vec<Attribute>,
2216 pub node: ForeignItemKind,
2219 pub vis: Visibility,
2222 /// An item within an `extern` block
2223 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
2224 pub enum ForeignItemKind {
2225 /// A foreign function
2226 Fn(P<FnDecl>, Generics),
2227 /// A foreign static item (`static ext: u8`), with optional mutability
2228 /// (the boolean is true when mutable)
2229 Static(P<Ty>, bool),
2232 /// A macro invocation
2236 impl ForeignItemKind {
2237 pub fn descriptive_variant(&self) -> &str {
2239 ForeignItemKind::Fn(..) => "foreign function",
2240 ForeignItemKind::Static(..) => "foreign static item",
2241 ForeignItemKind::Ty => "foreign type",
2242 ForeignItemKind::Macro(..) => "macro in foreign module",
2252 // are ASTs encodable?
2254 fn check_asts_encodable() {
2255 fn assert_encodable<T: serialize::Encodable>() {}
2256 assert_encodable::<Crate>();