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fuchsia / third_party / rust / cfcc5c296ed6fabcc8b9d380eaaea8a7352299fd / . / src / libsyntax / ast.rs
blob: bfb2db959636390e21257d2dee2b98a65ae0fb12 [file] [log] [blame]
// The Rust abstract syntax tree.
pub use GenericArgs::*;
pub use UnsafeSource::*;
pub use crate::symbol::{Ident, Symbol as Name};
pub use crate::util::parser::ExprPrecedence;
use crate::ext::hygiene::ExpnId;
use crate::parse::token::{self, DelimToken};
use crate::print::pprust;
use crate::ptr::P;
use crate::source_map::{dummy_spanned, respan, Spanned};
use crate::symbol::{kw, sym, Symbol};
use crate::tokenstream::TokenStream;
use crate::ThinVec;
use rustc_data_structures::indexed_vec::Idx;
#[cfg(target_arch = "x86_64")]
use rustc_data_structures::static_assert_size;
use rustc_target::spec::abi::Abi;
use syntax_pos::{Span, DUMMY_SP};
use rustc_data_structures::fx::FxHashSet;
use rustc_data_structures::sync::Lrc;
use rustc_serialize::{self, Decoder, Encoder};
use std::fmt;
pub use rustc_target::abi::FloatTy;
#[cfg(test)]
mod tests;
#[derive(Clone, RustcEncodable, RustcDecodable, Copy)]
pub struct Label {
pub ident: Ident,
}
impl fmt::Debug for Label {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "label({:?})", self.ident)
}
}
#[derive(Clone, RustcEncodable, RustcDecodable, Copy)]
pub struct Lifetime {
pub id: NodeId,
pub ident: Ident,
}
impl fmt::Debug for Lifetime {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(
f,
"lifetime({}: {})",
self.id,
self
)
}
}
impl fmt::Display for Lifetime {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", self.ident.name.as_str())
}
}
/// A "Path" is essentially Rust's notion of a name.
///
/// It's represented as a sequence of identifiers,
/// along with a bunch of supporting information.
///
/// E.g., `std::cmp::PartialEq`.
#[derive(Clone, RustcEncodable, RustcDecodable)]
pub struct Path {
pub span: Span,
/// The segments in the path: the things separated by `::`.
/// Global paths begin with `kw::PathRoot`.
pub segments: Vec<PathSegment>,
}
impl PartialEq<Symbol> for Path {
fn eq(&self, symbol: &Symbol) -> bool {
self.segments.len() == 1 && {
self.segments[0].ident.name == *symbol
}
}
}
impl fmt::Debug for Path {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "path({})", pprust::path_to_string(self))
}
}
impl fmt::Display for Path {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", pprust::path_to_string(self))
}
}
impl Path {
// Convert a span and an identifier to the corresponding
// one-segment path.
pub fn from_ident(ident: Ident) -> Path {
Path {
segments: vec![PathSegment::from_ident(ident)],
span: ident.span,
}
}
pub fn is_global(&self) -> bool {
!self.segments.is_empty() && self.segments[0].ident.name == kw::PathRoot
}
}
/// A segment of a path: an identifier, an optional lifetime, and a set of types.
///
/// E.g., `std`, `String` or `Box<T>`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct PathSegment {
/// The identifier portion of this path segment.
pub ident: Ident,
pub id: NodeId,
/// Type/lifetime parameters attached to this path. They come in
/// two flavors: `Path<A,B,C>` and `Path(A,B) -> C`.
/// `None` means that no parameter list is supplied (`Path`),
/// `Some` means that parameter list is supplied (`Path<X, Y>`)
/// but it can be empty (`Path<>`).
/// `P` is used as a size optimization for the common case with no parameters.
pub args: Option<P<GenericArgs>>,
}
impl PathSegment {
pub fn from_ident(ident: Ident) -> Self {
PathSegment { ident, id: DUMMY_NODE_ID, args: None }
}
pub fn path_root(span: Span) -> Self {
PathSegment::from_ident(Ident::new(kw::PathRoot, span))
}
}
/// The arguments of a path segment.
///
/// E.g., `<A, B>` as in `Foo<A, B>` or `(A, B)` as in `Foo(A, B)`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum GenericArgs {
/// The `<'a, A, B, C>` in `foo::bar::baz::<'a, A, B, C>`.
AngleBracketed(AngleBracketedArgs),
/// The `(A, B)` and `C` in `Foo(A, B) -> C`.
Parenthesized(ParenthesizedArgs),
}
impl GenericArgs {
pub fn is_parenthesized(&self) -> bool {
match *self {
Parenthesized(..) => true,
_ => false,
}
}
pub fn is_angle_bracketed(&self) -> bool {
match *self {
AngleBracketed(..) => true,
_ => false,
}
}
pub fn span(&self) -> Span {
match *self {
AngleBracketed(ref data) => data.span,
Parenthesized(ref data) => data.span,
}
}
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum GenericArg {
Lifetime(Lifetime),
Type(P<Ty>),
Const(AnonConst),
}
impl GenericArg {
pub fn span(&self) -> Span {
match self {
GenericArg::Lifetime(lt) => lt.ident.span,
GenericArg::Type(ty) => ty.span,
GenericArg::Const(ct) => ct.value.span,
}
}
}
/// A path like `Foo<'a, T>`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug, Default)]
pub struct AngleBracketedArgs {
/// The overall span.
pub span: Span,
/// The arguments for this path segment.
pub args: Vec<GenericArg>,
/// Constraints on associated types, if any.
/// E.g., `Foo<A = Bar, B: Baz>`.
pub constraints: Vec<AssocTyConstraint>,
}
impl Into<Option<P<GenericArgs>>> for AngleBracketedArgs {
fn into(self) -> Option<P<GenericArgs>> {
Some(P(GenericArgs::AngleBracketed(self)))
}
}
impl Into<Option<P<GenericArgs>>> for ParenthesizedArgs {
fn into(self) -> Option<P<GenericArgs>> {
Some(P(GenericArgs::Parenthesized(self)))
}
}
/// A path like `Foo(A, B) -> C`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct ParenthesizedArgs {
/// Overall span
pub span: Span,
/// `(A, B)`
pub inputs: Vec<P<Ty>>,
/// `C`
pub output: Option<P<Ty>>,
}
impl ParenthesizedArgs {
pub fn as_angle_bracketed_args(&self) -> AngleBracketedArgs {
AngleBracketedArgs {
span: self.span,
args: self.inputs.iter().cloned().map(|input| GenericArg::Type(input)).collect(),
constraints: vec![],
}
}
}
// hack to ensure that we don't try to access the private parts of `NodeId` in this module
mod node_id_inner {
use rustc_data_structures::indexed_vec::Idx;
use rustc_data_structures::newtype_index;
newtype_index! {
pub struct NodeId {
ENCODABLE = custom
DEBUG_FORMAT = "NodeId({})"
}
}
}
pub use node_id_inner::NodeId;
impl NodeId {
pub fn placeholder_from_expn_id(expn_id: ExpnId) -> Self {
NodeId::from_u32(expn_id.as_u32())
}
pub fn placeholder_to_expn_id(self) -> ExpnId {
ExpnId::from_u32(self.as_u32())
}
}
impl fmt::Display for NodeId {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(&self.as_u32(), f)
}
}
impl rustc_serialize::UseSpecializedEncodable for NodeId {
fn default_encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
s.emit_u32(self.as_u32())
}
}
impl rustc_serialize::UseSpecializedDecodable for NodeId {
fn default_decode<D: Decoder>(d: &mut D) -> Result<NodeId, D::Error> {
d.read_u32().map(NodeId::from_u32)
}
}
/// `NodeId` used to represent the root of the crate.
pub const CRATE_NODE_ID: NodeId = NodeId::from_u32_const(0);
/// When parsing and doing expansions, we initially give all AST nodes this AST
/// node value. Then later, in the renumber pass, we renumber them to have
/// small, positive ids.
pub const DUMMY_NODE_ID: NodeId = NodeId::MAX;
/// A modifier on a bound, currently this is only used for `?Sized`, where the
/// modifier is `Maybe`. Negative bounds should also be handled here.
#[derive(Copy, Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Debug)]
pub enum TraitBoundModifier {
None,
Maybe,
}
/// The AST represents all type param bounds as types.
/// `typeck::collect::compute_bounds` matches these against
/// the "special" built-in traits (see `middle::lang_items`) and
/// detects `Copy`, `Send` and `Sync`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum GenericBound {
Trait(PolyTraitRef, TraitBoundModifier),
Outlives(Lifetime),
}
impl GenericBound {
pub fn span(&self) -> Span {
match self {
&GenericBound::Trait(ref t, ..) => t.span,
&GenericBound::Outlives(ref l) => l.ident.span,
}
}
}
pub type GenericBounds = Vec<GenericBound>;
/// Specifies the enforced ordering for generic parameters. In the future,
/// if we wanted to relax this order, we could override `PartialEq` and
/// `PartialOrd`, to allow the kinds to be unordered.
#[derive(PartialEq, Eq, PartialOrd, Ord, Hash, Clone, Copy)]
pub enum ParamKindOrd {
Lifetime,
Type,
Const,
}
impl fmt::Display for ParamKindOrd {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
ParamKindOrd::Lifetime => "lifetime".fmt(f),
ParamKindOrd::Type => "type".fmt(f),
ParamKindOrd::Const => "const".fmt(f),
}
}
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum GenericParamKind {
/// A lifetime definition (e.g., `'a: 'b + 'c + 'd`).
Lifetime,
Type { default: Option<P<Ty>> },
Const { ty: P<Ty> },
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct GenericParam {
pub id: NodeId,
pub ident: Ident,
pub attrs: ThinVec<Attribute>,
pub bounds: GenericBounds,
pub kind: GenericParamKind,
}
/// Represents lifetime, type and const parameters attached to a declaration of
/// a function, enum, trait, etc.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct Generics {
pub params: Vec<GenericParam>,
pub where_clause: WhereClause,
pub span: Span,
}
impl Default for Generics {
/// Creates an instance of `Generics`.
fn default() -> Generics {
Generics {
params: Vec::new(),
where_clause: WhereClause {
predicates: Vec::new(),
span: DUMMY_SP,
},
span: DUMMY_SP,
}
}
}
/// A where-clause in a definition.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct WhereClause {
pub predicates: Vec<WherePredicate>,
pub span: Span,
}
/// A single predicate in a where-clause.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum WherePredicate {
/// A type binding (e.g., `for<'c> Foo: Send + Clone + 'c`).
BoundPredicate(WhereBoundPredicate),
/// A lifetime predicate (e.g., `'a: 'b + 'c`).
RegionPredicate(WhereRegionPredicate),
/// An equality predicate (unsupported).
EqPredicate(WhereEqPredicate),
}
impl WherePredicate {
pub fn span(&self) -> Span {
match self {
&WherePredicate::BoundPredicate(ref p) => p.span,
&WherePredicate::RegionPredicate(ref p) => p.span,
&WherePredicate::EqPredicate(ref p) => p.span,
}
}
}
/// A type bound.
///
/// E.g., `for<'c> Foo: Send + Clone + 'c`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct WhereBoundPredicate {
pub span: Span,
/// Any generics from a `for` binding.
pub bound_generic_params: Vec<GenericParam>,
/// The type being bounded.
pub bounded_ty: P<Ty>,
/// Trait and lifetime bounds (`Clone + Send + 'static`).
pub bounds: GenericBounds,
}
/// A lifetime predicate.
///
/// E.g., `'a: 'b + 'c`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct WhereRegionPredicate {
pub span: Span,
pub lifetime: Lifetime,
pub bounds: GenericBounds,
}
/// An equality predicate (unsupported).
///
/// E.g., `T = int`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct WhereEqPredicate {
pub id: NodeId,
pub span: Span,
pub lhs_ty: P<Ty>,
pub rhs_ty: P<Ty>,
}
/// The set of `MetaItem`s that define the compilation environment of the crate,
/// used to drive conditional compilation.
pub type CrateConfig = FxHashSet<(Name, Option<Symbol>)>;
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct Crate {
pub module: Mod,
pub attrs: Vec<Attribute>,
pub span: Span,
}
/// Possible values inside of compile-time attribute lists.
///
/// E.g., the '..' in `#[name(..)]`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum NestedMetaItem {
/// A full MetaItem, for recursive meta items.
MetaItem(MetaItem),
/// A literal.
///
/// E.g., `"foo"`, `64`, `true`.
Literal(Lit),
}
/// A spanned compile-time attribute item.
///
/// E.g., `#[test]`, `#[derive(..)]`, `#[rustfmt::skip]` or `#[feature = "foo"]`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct MetaItem {
pub path: Path,
pub node: MetaItemKind,
pub span: Span,
}
/// A compile-time attribute item.
///
/// E.g., `#[test]`, `#[derive(..)]` or `#[feature = "foo"]`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum MetaItemKind {
/// Word meta item.
///
/// E.g., `test` as in `#[test]`.
Word,
/// List meta item.
///
/// E.g., `derive(..)` as in `#[derive(..)]`.
List(Vec<NestedMetaItem>),
/// Name value meta item.
///
/// E.g., `feature = "foo"` as in `#[feature = "foo"]`.
NameValue(Lit),
}
/// A block (`{ .. }`).
///
/// E.g., `{ .. }` as in `fn foo() { .. }`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct Block {
/// The statements in the block.
pub stmts: Vec<Stmt>,
pub id: NodeId,
/// Distinguishes between `unsafe { ... }` and `{ ... }`.
pub rules: BlockCheckMode,
pub span: Span,
}
#[derive(Clone, RustcEncodable, RustcDecodable)]
pub struct Pat {
pub id: NodeId,
pub node: PatKind,
pub span: Span,
}
impl fmt::Debug for Pat {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "pat({}: {})", self.id, pprust::pat_to_string(self))
}
}
impl Pat {
/// Attempt reparsing the pattern as a type.
/// This is intended for use by diagnostics.
pub(super) fn to_ty(&self) -> Option<P<Ty>> {
let node = match &self.node {
// In a type expression `_` is an inference variable.
PatKind::Wild => TyKind::Infer,
// An IDENT pattern with no binding mode would be valid as path to a type. E.g. `u32`.
PatKind::Ident(BindingMode::ByValue(Mutability::Immutable), ident, None) => {
TyKind::Path(None, Path::from_ident(*ident))
}
PatKind::Path(qself, path) => TyKind::Path(qself.clone(), path.clone()),
PatKind::Mac(mac) => TyKind::Mac(mac.clone()),
// `&mut? P` can be reinterpreted as `&mut? T` where `T` is `P` reparsed as a type.
PatKind::Ref(pat, mutbl) => pat
.to_ty()
.map(|ty| TyKind::Rptr(None, MutTy { ty, mutbl: *mutbl }))?,
// A slice/array pattern `[P]` can be reparsed as `[T]`, an unsized array,
// when `P` can be reparsed as a type `T`.
PatKind::Slice(pats) if pats.len() == 1 => pats[0].to_ty().map(TyKind::Slice)?,
// A tuple pattern `(P0, .., Pn)` can be reparsed as `(T0, .., Tn)`
// assuming `T0` to `Tn` are all syntactically valid as types.
PatKind::Tuple(pats) => {
let mut tys = Vec::with_capacity(pats.len());
// FIXME(#48994) - could just be collected into an Option<Vec>
for pat in pats {
tys.push(pat.to_ty()?);
}
TyKind::Tup(tys)
}
_ => return None,
};
Some(P(Ty {
node,
id: self.id,
span: self.span,
}))
}
/// Walk top-down and call `it` in each place where a pattern occurs
/// starting with the root pattern `walk` is called on. If `it` returns
/// false then we will descend no further but siblings will be processed.
pub fn walk(&self, it: &mut impl FnMut(&Pat) -> bool) {
if !it(self) {
return;
}
match &self.node {
PatKind::Ident(_, _, Some(p)) => p.walk(it),
PatKind::Struct(_, fields, _) => fields.iter().for_each(|field| field.pat.walk(it)),
PatKind::TupleStruct(_, s)
| PatKind::Tuple(s)
| PatKind::Slice(s)
| PatKind::Or(s) => s.iter().for_each(|p| p.walk(it)),
PatKind::Box(s)
| PatKind::Ref(s, _)
| PatKind::Paren(s) => s.walk(it),
PatKind::Wild
| PatKind::Rest
| PatKind::Lit(_)
| PatKind::Range(..)
| PatKind::Ident(..)
| PatKind::Path(..)
| PatKind::Mac(_) => {},
}
}
/// Is this a `..` pattern?
pub fn is_rest(&self) -> bool {
match self.node {
PatKind::Rest => true,
_ => false,
}
}
}
/// A single field in a struct pattern
///
/// Patterns like the fields of Foo `{ x, ref y, ref mut z }`
/// are treated the same as` x: x, y: ref y, z: ref mut z`,
/// except is_shorthand is true
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct FieldPat {
/// The identifier for the field
pub ident: Ident,
/// The pattern the field is destructured to
pub pat: P<Pat>,
pub is_shorthand: bool,
pub attrs: ThinVec<Attribute>,
pub id: NodeId,
pub span: Span,
}
#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
pub enum BindingMode {
ByRef(Mutability),
ByValue(Mutability),
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum RangeEnd {
Included(RangeSyntax),
Excluded,
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum RangeSyntax {
DotDotDot,
DotDotEq,
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum PatKind {
/// Represents a wildcard pattern (`_`).
Wild,
/// A `PatKind::Ident` may either be a new bound variable (`ref mut binding @ OPT_SUBPATTERN`),
/// or a unit struct/variant pattern, or a const pattern (in the last two cases the third
/// field must be `None`). Disambiguation cannot be done with parser alone, so it happens
/// during name resolution.
Ident(BindingMode, Ident, Option<P<Pat>>),
/// A struct or struct variant pattern (e.g., `Variant {x, y, ..}`).
/// The `bool` is `true` in the presence of a `..`.
Struct(Path, Vec<FieldPat>, /* recovered */ bool),
/// A tuple struct/variant pattern (`Variant(x, y, .., z)`).
TupleStruct(Path, Vec<P<Pat>>),
/// An or-pattern `A | B | C`.
/// Invariant: `pats.len() >= 2`.
Or(Vec<P<Pat>>),
/// A possibly qualified path pattern.
/// Unqualified path patterns `A::B::C` can legally refer to variants, structs, constants
/// or associated constants. Qualified path patterns `<A>::B::C`/`<A as Trait>::B::C` can
/// only legally refer to associated constants.
Path(Option<QSelf>, Path),
/// A tuple pattern (`(a, b)`).
Tuple(Vec<P<Pat>>),
/// A `box` pattern.
Box(P<Pat>),
/// A reference pattern (e.g., `&mut (a, b)`).
Ref(P<Pat>, Mutability),
/// A literal.
Lit(P<Expr>),
/// A range pattern (e.g., `1...2`, `1..=2` or `1..2`).
Range(P<Expr>, P<Expr>, Spanned<RangeEnd>),
/// A slice pattern `[a, b, c]`.
Slice(Vec<P<Pat>>),
/// A rest pattern `..`.
///
/// Syntactically it is valid anywhere.
///
/// Semantically however, it only has meaning immediately inside:
/// - a slice pattern: `[a, .., b]`,
/// - a binding pattern immediately inside a slice pattern: `[a, r @ ..]`,
/// - a tuple pattern: `(a, .., b)`,
/// - a tuple struct/variant pattern: `$path(a, .., b)`.
///
/// In all of these cases, an additional restriction applies,
/// only one rest pattern may occur in the pattern sequences.
Rest,
/// Parentheses in patterns used for grouping (i.e., `(PAT)`).
Paren(P<Pat>),
/// A macro pattern; pre-expansion.
Mac(Mac),
}
#[derive(
Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable, Debug, Copy,
)]
pub enum Mutability {
Mutable,
Immutable,
}
#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
pub enum BinOpKind {
/// The `+` operator (addition)
Add,
/// The `-` operator (subtraction)
Sub,
/// The `*` operator (multiplication)
Mul,
/// The `/` operator (division)
Div,
/// The `%` operator (modulus)
Rem,
/// The `&&` operator (logical and)
And,
/// The `||` operator (logical or)
Or,
/// The `^` operator (bitwise xor)
BitXor,
/// The `&` operator (bitwise and)
BitAnd,
/// The `|` operator (bitwise or)
BitOr,
/// The `<<` operator (shift left)
Shl,
/// The `>>` operator (shift right)
Shr,
/// The `==` operator (equality)
Eq,
/// The `<` operator (less than)
Lt,
/// The `<=` operator (less than or equal to)
Le,
/// The `!=` operator (not equal to)
Ne,
/// The `>=` operator (greater than or equal to)
Ge,
/// The `>` operator (greater than)
Gt,
}
impl BinOpKind {
pub fn to_string(&self) -> &'static str {
use BinOpKind::*;
match *self {
Add => "+",
Sub => "-",
Mul => "*",
Div => "/",
Rem => "%",
And => "&&",
Or => "||",
BitXor => "^",
BitAnd => "&",
BitOr => "|",
Shl => "<<",
Shr => ">>",
Eq => "==",
Lt => "<",
Le => "<=",
Ne => "!=",
Ge => ">=",
Gt => ">",
}
}
pub fn lazy(&self) -> bool {
match *self {
BinOpKind::And | BinOpKind::Or => true,
_ => false,
}
}
pub fn is_shift(&self) -> bool {
match *self {
BinOpKind::Shl | BinOpKind::Shr => true,
_ => false,
}
}
pub fn is_comparison(&self) -> bool {
use BinOpKind::*;
match *self {
Eq | Lt | Le | Ne | Gt | Ge => true,
And | Or | Add | Sub | Mul | Div | Rem | BitXor | BitAnd | BitOr | Shl | Shr => false,
}
}
/// Returns `true` if the binary operator takes its arguments by value
pub fn is_by_value(&self) -> bool {
!self.is_comparison()
}
}
pub type BinOp = Spanned<BinOpKind>;
#[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy)]
pub enum UnOp {
/// The `*` operator for dereferencing
Deref,
/// The `!` operator for logical inversion
Not,
/// The `-` operator for negation
Neg,
}
impl UnOp {
/// Returns `true` if the unary operator takes its argument by value
pub fn is_by_value(u: UnOp) -> bool {
match u {
UnOp::Neg | UnOp::Not => true,
_ => false,
}
}
pub fn to_string(op: UnOp) -> &'static str {
match op {
UnOp::Deref => "*",
UnOp::Not => "!",
UnOp::Neg => "-",
}
}
}
/// A statement
#[derive(Clone, RustcEncodable, RustcDecodable)]
pub struct Stmt {
pub id: NodeId,
pub node: StmtKind,
pub span: Span,
}
impl Stmt {
pub fn add_trailing_semicolon(mut self) -> Self {
self.node = match self.node {
StmtKind::Expr(expr) => StmtKind::Semi(expr),
StmtKind::Mac(mac) => {
StmtKind::Mac(mac.map(|(mac, _style, attrs)| (mac, MacStmtStyle::Semicolon, attrs)))
}
node => node,
};
self
}
pub fn is_item(&self) -> bool {
match self.node {
StmtKind::Item(_) => true,
_ => false,
}
}
pub fn is_expr(&self) -> bool {
match self.node {
StmtKind::Expr(_) => true,
_ => false,
}
}
}
impl fmt::Debug for Stmt {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(
f,
"stmt({}: {})",
self.id.to_string(),
pprust::stmt_to_string(self)
)
}
}
#[derive(Clone, RustcEncodable, RustcDecodable)]
pub enum StmtKind {
/// A local (let) binding.
Local(P<Local>),
/// An item definition.
Item(P<Item>),
/// Expr without trailing semi-colon.
Expr(P<Expr>),
/// Expr with a trailing semi-colon.
Semi(P<Expr>),
/// Macro.
Mac(P<(Mac, MacStmtStyle, ThinVec<Attribute>)>),
}
#[derive(Clone, Copy, PartialEq, RustcEncodable, RustcDecodable, Debug)]
pub enum MacStmtStyle {
/// The macro statement had a trailing semicolon (e.g., `foo! { ... };`
/// `foo!(...);`, `foo![...];`).
Semicolon,
/// The macro statement had braces (e.g., `foo! { ... }`).
Braces,
/// The macro statement had parentheses or brackets and no semicolon (e.g.,
/// `foo!(...)`). All of these will end up being converted into macro
/// expressions.
NoBraces,
}
/// Local represents a `let` statement, e.g., `let <pat>:<ty> = <expr>;`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct Local {
pub id: NodeId,
pub pat: P<Pat>,
pub ty: Option<P<Ty>>,
/// Initializer expression to set the value, if any.
pub init: Option<P<Expr>>,
pub span: Span,
pub attrs: ThinVec<Attribute>,
}
/// An arm of a 'match'.
///
/// E.g., `0..=10 => { println!("match!") }` as in
///
/// ```
/// match 123 {
/// 0..=10 => { println!("match!") },
/// _ => { println!("no match!") },
/// }
/// ```
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct Arm {
pub attrs: Vec<Attribute>,
pub pat: P<Pat>,
pub guard: Option<P<Expr>>,
pub body: P<Expr>,
pub span: Span,
pub id: NodeId,
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct Field {
pub ident: Ident,
pub expr: P<Expr>,
pub span: Span,
pub is_shorthand: bool,
pub attrs: ThinVec<Attribute>,
pub id: NodeId,
}
#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
pub enum BlockCheckMode {
Default,
Unsafe(UnsafeSource),
}
#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
pub enum UnsafeSource {
CompilerGenerated,
UserProvided,
}
/// A constant (expression) that's not an item or associated item,
/// but needs its own `DefId` for type-checking, const-eval, etc.
/// These are usually found nested inside types (e.g., array lengths)
/// or expressions (e.g., repeat counts), and also used to define
/// explicit discriminant values for enum variants.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct AnonConst {
pub id: NodeId,
pub value: P<Expr>,
}
/// An expression.
#[derive(Clone, RustcEncodable, RustcDecodable)]
pub struct Expr {
pub id: NodeId,
pub node: ExprKind,
pub span: Span,
pub attrs: ThinVec<Attribute>,
}
// `Expr` is used a lot. Make sure it doesn't unintentionally get bigger.
#[cfg(target_arch = "x86_64")]
static_assert_size!(Expr, 96);
impl Expr {
/// Returns `true` if this expression would be valid somewhere that expects a value;
/// for example, an `if` condition.
pub fn returns(&self) -> bool {
if let ExprKind::Block(ref block, _) = self.node {
match block.stmts.last().map(|last_stmt| &last_stmt.node) {
// Implicit return
Some(&StmtKind::Expr(_)) => true,
Some(&StmtKind::Semi(ref expr)) => {
if let ExprKind::Ret(_) = expr.node {
// Last statement is explicit return.
true
} else {
false
}
}
// This is a block that doesn't end in either an implicit or explicit return.
_ => false,
}
} else {
// This is not a block, it is a value.
true
}
}
fn to_bound(&self) -> Option<GenericBound> {
match &self.node {
ExprKind::Path(None, path) => Some(GenericBound::Trait(
PolyTraitRef::new(Vec::new(), path.clone(), self.span),
TraitBoundModifier::None,
)),
_ => None,
}
}
pub(super) fn to_ty(&self) -> Option<P<Ty>> {
let node = match &self.node {
ExprKind::Path(qself, path) => TyKind::Path(qself.clone(), path.clone()),
ExprKind::Mac(mac) => TyKind::Mac(mac.clone()),
ExprKind::Paren(expr) => expr.to_ty().map(TyKind::Paren)?,
ExprKind::AddrOf(mutbl, expr) => expr
.to_ty()
.map(|ty| TyKind::Rptr(None, MutTy { ty, mutbl: *mutbl }))?,
ExprKind::Repeat(expr, expr_len) => {
expr.to_ty().map(|ty| TyKind::Array(ty, expr_len.clone()))?
}
ExprKind::Array(exprs) if exprs.len() == 1 => exprs[0].to_ty().map(TyKind::Slice)?,
ExprKind::Tup(exprs) => {
let tys = exprs
.iter()
.map(|expr| expr.to_ty())
.collect::<Option<Vec<_>>>()?;
TyKind::Tup(tys)
}
ExprKind::Binary(binop, lhs, rhs) if binop.node == BinOpKind::Add => {
if let (Some(lhs), Some(rhs)) = (lhs.to_bound(), rhs.to_bound()) {
TyKind::TraitObject(vec![lhs, rhs], TraitObjectSyntax::None)
} else {
return None;
}
}
_ => return None,
};
Some(P(Ty {
node,
id: self.id,
span: self.span,
}))
}
pub fn precedence(&self) -> ExprPrecedence {
match self.node {
ExprKind::Box(_) => ExprPrecedence::Box,
ExprKind::Array(_) => ExprPrecedence::Array,
ExprKind::Call(..) => ExprPrecedence::Call,
ExprKind::MethodCall(..) => ExprPrecedence::MethodCall,
ExprKind::Tup(_) => ExprPrecedence::Tup,
ExprKind::Binary(op, ..) => ExprPrecedence::Binary(op.node),
ExprKind::Unary(..) => ExprPrecedence::Unary,
ExprKind::Lit(_) => ExprPrecedence::Lit,
ExprKind::Type(..) | ExprKind::Cast(..) => ExprPrecedence::Cast,
ExprKind::Let(..) => ExprPrecedence::Let,
ExprKind::If(..) => ExprPrecedence::If,
ExprKind::While(..) => ExprPrecedence::While,
ExprKind::ForLoop(..) => ExprPrecedence::ForLoop,
ExprKind::Loop(..) => ExprPrecedence::Loop,
ExprKind::Match(..) => ExprPrecedence::Match,
ExprKind::Closure(..) => ExprPrecedence::Closure,
ExprKind::Block(..) => ExprPrecedence::Block,
ExprKind::TryBlock(..) => ExprPrecedence::TryBlock,
ExprKind::Async(..) => ExprPrecedence::Async,
ExprKind::Await(..) => ExprPrecedence::Await,
ExprKind::Assign(..) => ExprPrecedence::Assign,
ExprKind::AssignOp(..) => ExprPrecedence::AssignOp,
ExprKind::Field(..) => ExprPrecedence::Field,
ExprKind::Index(..) => ExprPrecedence::Index,
ExprKind::Range(..) => ExprPrecedence::Range,
ExprKind::Path(..) => ExprPrecedence::Path,
ExprKind::AddrOf(..) => ExprPrecedence::AddrOf,
ExprKind::Break(..) => ExprPrecedence::Break,
ExprKind::Continue(..) => ExprPrecedence::Continue,
ExprKind::Ret(..) => ExprPrecedence::Ret,
ExprKind::InlineAsm(..) => ExprPrecedence::InlineAsm,
ExprKind::Mac(..) => ExprPrecedence::Mac,
ExprKind::Struct(..) => ExprPrecedence::Struct,
ExprKind::Repeat(..) => ExprPrecedence::Repeat,
ExprKind::Paren(..) => ExprPrecedence::Paren,
ExprKind::Try(..) => ExprPrecedence::Try,
ExprKind::Yield(..) => ExprPrecedence::Yield,
ExprKind::Err => ExprPrecedence::Err,
}
}
}
impl fmt::Debug for Expr {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "expr({}: {})", self.id, pprust::expr_to_string(self))
}
}
/// Limit types of a range (inclusive or exclusive)
#[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
pub enum RangeLimits {
/// Inclusive at the beginning, exclusive at the end
HalfOpen,
/// Inclusive at the beginning and end
Closed,
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum ExprKind {
/// A `box x` expression.
Box(P<Expr>),
/// An array (`[a, b, c, d]`)
Array(Vec<P<Expr>>),
/// A function call
///
/// The first field resolves to the function itself,
/// and the second field is the list of arguments.
/// This also represents calling the constructor of
/// tuple-like ADTs such as tuple structs and enum variants.
Call(P<Expr>, Vec<P<Expr>>),
/// A method call (`x.foo::<'static, Bar, Baz>(a, b, c, d)`)
///
/// The `PathSegment` represents the method name and its generic arguments
/// (within the angle brackets).
/// The first element of the vector of an `Expr` is the expression that evaluates
/// to the object on which the method is being called on (the receiver),
/// and the remaining elements are the rest of the arguments.
/// Thus, `x.foo::<Bar, Baz>(a, b, c, d)` is represented as
/// `ExprKind::MethodCall(PathSegment { foo, [Bar, Baz] }, [x, a, b, c, d])`.
MethodCall(PathSegment, Vec<P<Expr>>),
/// A tuple (e.g., `(a, b, c, d)`).
Tup(Vec<P<Expr>>),
/// A binary operation (e.g., `a + b`, `a * b`).
Binary(BinOp, P<Expr>, P<Expr>),
/// A unary operation (e.g., `!x`, `*x`).
Unary(UnOp, P<Expr>),
/// A literal (e.g., `1`, `"foo"`).
Lit(Lit),
/// A cast (e.g., `foo as f64`).
Cast(P<Expr>, P<Ty>),
/// A type ascription (e.g., `42: usize`).
Type(P<Expr>, P<Ty>),
/// A `let pat = expr` expression that is only semantically allowed in the condition
/// of `if` / `while` expressions. (e.g., `if let 0 = x { .. }`).
Let(P<Pat>, P<Expr>),
/// An `if` block, with an optional `else` block.
///
/// `if expr { block } else { expr }`
If(P<Expr>, P<Block>, Option<P<Expr>>),
/// A while loop, with an optional label.
///
/// `'label: while expr { block }`
While(P<Expr>, P<Block>, Option<Label>),
/// A `for` loop, with an optional label.
///
/// `'label: for pat in expr { block }`
///
/// This is desugared to a combination of `loop` and `match` expressions.
ForLoop(P<Pat>, P<Expr>, P<Block>, Option<Label>),
/// Conditionless loop (can be exited with `break`, `continue`, or `return`).
///
/// `'label: loop { block }`
Loop(P<Block>, Option<Label>),
/// A `match` block.
Match(P<Expr>, Vec<Arm>),
/// A closure (e.g., `move |a, b, c| a + b + c`).
///
/// The final span is the span of the argument block `|...|`.
Closure(CaptureBy, IsAsync, Movability, P<FnDecl>, P<Expr>, Span),
/// A block (`'label: { ... }`).
Block(P<Block>, Option<Label>),
/// An async block (`async move { ... }`).
///
/// The `NodeId` is the `NodeId` for the closure that results from
/// desugaring an async block, just like the NodeId field in the
/// `IsAsync` enum. This is necessary in order to create a def for the
/// closure which can be used as a parent of any child defs. Defs
/// created during lowering cannot be made the parent of any other
/// preexisting defs.
Async(CaptureBy, NodeId, P<Block>),
/// An await expression (`my_future.await`).
Await(P<Expr>),
/// A try block (`try { ... }`).
TryBlock(P<Block>),
/// An assignment (`a = foo()`).
Assign(P<Expr>, P<Expr>),
/// An assignment with an operator.
///
/// E.g., `a += 1`.
AssignOp(BinOp, P<Expr>, P<Expr>),
/// Access of a named (e.g., `obj.foo`) or unnamed (e.g., `obj.0`) struct field.
Field(P<Expr>, Ident),
/// An indexing operation (e.g., `foo[2]`).
Index(P<Expr>, P<Expr>),
/// A range (e.g., `1..2`, `1..`, `..2`, `1..=2`, `..=2`).
Range(Option<P<Expr>>, Option<P<Expr>>, RangeLimits),
/// Variable reference, possibly containing `::` and/or type
/// parameters (e.g., `foo::bar::<baz>`).
///
/// Optionally "qualified" (e.g., `<Vec<T> as SomeTrait>::SomeType`).
Path(Option<QSelf>, Path),
/// A referencing operation (`&a` or `&mut a`).
AddrOf(Mutability, P<Expr>),
/// A `break`, with an optional label to break, and an optional expression.
Break(Option<Label>, Option<P<Expr>>),
/// A `continue`, with an optional label.
Continue(Option<Label>),
/// A `return`, with an optional value to be returned.
Ret(Option<P<Expr>>),
/// Output of the `asm!()` macro.
InlineAsm(P<InlineAsm>),
/// A macro invocation; pre-expansion.
Mac(Mac),
/// A struct literal expression.
///
/// E.g., `Foo {x: 1, y: 2}`, or `Foo {x: 1, .. base}`,
/// where `base` is the `Option<Expr>`.
Struct(Path, Vec<Field>, Option<P<Expr>>),
/// An array literal constructed from one repeated element.
///
/// E.g., `[1; 5]`. The expression is the element to be
/// repeated; the constant is the number of times to repeat it.
Repeat(P<Expr>, AnonConst),
/// No-op: used solely so we can pretty-print faithfully.
Paren(P<Expr>),
/// A try expression (`expr?`).
Try(P<Expr>),
/// A `yield`, with an optional value to be yielded.
Yield(Option<P<Expr>>),
/// Placeholder for an expression that wasn't syntactically well formed in some way.
Err,
}
/// The explicit `Self` type in a "qualified path". The actual
/// path, including the trait and the associated item, is stored
/// separately. `position` represents the index of the associated
/// item qualified with this `Self` type.
///
/// ```ignore (only-for-syntax-highlight)
/// <Vec<T> as a::b::Trait>::AssociatedItem
/// ^~~~~ ~~~~~~~~~~~~~~^
/// ty position = 3
///
/// <Vec<T>>::AssociatedItem
/// ^~~~~ ^
/// ty position = 0
/// ```
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct QSelf {
pub ty: P<Ty>,
/// The span of `a::b::Trait` in a path like `<Vec<T> as
/// a::b::Trait>::AssociatedItem`; in the case where `position ==
/// 0`, this is an empty span.
pub path_span: Span,
pub position: usize,
}
/// A capture clause.
#[derive(Clone, Copy, PartialEq, RustcEncodable, RustcDecodable, Debug)]
pub enum CaptureBy {
Value,
Ref,
}
/// The movability of a generator / closure literal.
#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
pub enum Movability {
Static,
Movable,
}
/// Represents a macro invocation. The `Path` indicates which macro
/// is being invoked, and the vector of token-trees contains the source
/// of the macro invocation.
///
/// N.B., the additional ident for a `macro_rules`-style macro is actually
/// stored in the enclosing item.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct Mac {
pub path: Path,
pub delim: MacDelimiter,
pub tts: TokenStream,
pub span: Span,
pub prior_type_ascription: Option<(Span, bool)>,
}
#[derive(Copy, Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Debug)]
pub enum MacDelimiter {
Parenthesis,
Bracket,
Brace,
}
impl Mac {
pub fn stream(&self) -> TokenStream {
self.tts.clone()
}
}
impl MacDelimiter {
crate fn to_token(self) -> DelimToken {
match self {
MacDelimiter::Parenthesis => DelimToken::Paren,
MacDelimiter::Bracket => DelimToken::Bracket,
MacDelimiter::Brace => DelimToken::Brace,
}
}
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct MacroDef {
pub tokens: TokenStream,
pub legacy: bool,
}
impl MacroDef {
pub fn stream(&self) -> TokenStream {
self.tokens.clone().into()
}
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy, Hash, PartialEq)]
pub enum StrStyle {
/// A regular string, like `"foo"`.
Cooked,
/// A raw string, like `r##"foo"##`.
///
/// The value is the number of `#` symbols used.
Raw(u16),
}
/// An AST literal.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct Lit {
/// The original literal token as written in source code.
pub token: token::Lit,
/// The "semantic" representation of the literal lowered from the original tokens.
/// Strings are unescaped, hexadecimal forms are eliminated, etc.
/// FIXME: Remove this and only create the semantic representation during lowering to HIR.
pub node: LitKind,
pub span: Span,
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy, Hash, PartialEq)]
pub enum LitIntType {
Signed(IntTy),
Unsigned(UintTy),
Unsuffixed,
}
/// Literal kind.
///
/// E.g., `"foo"`, `42`, `12.34`, or `bool`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug, Hash, PartialEq)]
pub enum LitKind {
/// A string literal (`"foo"`).
Str(Symbol, StrStyle),
/// A byte string (`b"foo"`).
ByteStr(Lrc<Vec<u8>>),
/// A byte char (`b'f'`).
Byte(u8),
/// A character literal (`'a'`).
Char(char),
/// An integer literal (`1`).
Int(u128, LitIntType),
/// A float literal (`1f64` or `1E10f64`).
Float(Symbol, FloatTy),
/// A float literal without a suffix (`1.0 or 1.0E10`).
FloatUnsuffixed(Symbol),
/// A boolean literal.
Bool(bool),
/// Placeholder for a literal that wasn't well-formed in some way.
Err(Symbol),
}
impl LitKind {
/// Returns `true` if this literal is a string.
pub fn is_str(&self) -> bool {
match *self {
LitKind::Str(..) => true,
_ => false,
}
}
/// Returns `true` if this literal is byte literal string.
pub fn is_bytestr(&self) -> bool {
match self {
LitKind::ByteStr(_) => true,
_ => false,
}
}
/// Returns `true` if this is a numeric literal.
pub fn is_numeric(&self) -> bool {
match *self {
LitKind::Int(..) | LitKind::Float(..) | LitKind::FloatUnsuffixed(..) => true,
_ => false,
}
}
/// Returns `true` if this literal has no suffix.
/// Note: this will return true for literals with prefixes such as raw strings and byte strings.
pub fn is_unsuffixed(&self) -> bool {
match *self {
// unsuffixed variants
LitKind::Str(..)
| LitKind::ByteStr(..)
| LitKind::Byte(..)
| LitKind::Char(..)
| LitKind::Int(_, LitIntType::Unsuffixed)
| LitKind::FloatUnsuffixed(..)
| LitKind::Bool(..)
| LitKind::Err(..) => true,
// suffixed variants
LitKind::Int(_, LitIntType::Signed(..))
| LitKind::Int(_, LitIntType::Unsigned(..))
| LitKind::Float(..) => false,
}
}
/// Returns `true` if this literal has a suffix.
pub fn is_suffixed(&self) -> bool {
!self.is_unsuffixed()
}
}
// N.B., If you change this, you'll probably want to change the corresponding
// type structure in `middle/ty.rs` as well.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct MutTy {
pub ty: P<Ty>,
pub mutbl: Mutability,
}
/// Represents a method's signature in a trait declaration,
/// or in an implementation.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct MethodSig {
pub header: FnHeader,
pub decl: P<FnDecl>,
}
/// Represents an item declaration within a trait declaration,
/// possibly including a default implementation. A trait item is
/// either required (meaning it doesn't have an implementation, just a
/// signature) or provided (meaning it has a default implementation).
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct TraitItem {
pub id: NodeId,
pub ident: Ident,
pub attrs: Vec<Attribute>,
pub generics: Generics,
pub node: TraitItemKind,
pub span: Span,
/// See `Item::tokens` for what this is.
pub tokens: Option<TokenStream>,
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum TraitItemKind {
Const(P<Ty>, Option<P<Expr>>),
Method(MethodSig, Option<P<Block>>),
Type(GenericBounds, Option<P<Ty>>),
Macro(Mac),
}
/// Represents anything within an `impl` block.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct ImplItem {
pub id: NodeId,
pub ident: Ident,
pub vis: Visibility,
pub defaultness: Defaultness,
pub attrs: Vec<Attribute>,
pub generics: Generics,
pub node: ImplItemKind,
pub span: Span,
/// See `Item::tokens` for what this is.
pub tokens: Option<TokenStream>,
}
/// Represents various kinds of content within an `impl`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum ImplItemKind {
Const(P<Ty>, P<Expr>),
Method(MethodSig, P<Block>),
TyAlias(P<Ty>),
OpaqueTy(GenericBounds),
Macro(Mac),
}
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable, Copy)]
pub enum IntTy {
Isize,
I8,
I16,
I32,
I64,
I128,
}
impl fmt::Debug for IntTy {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(self, f)
}
}
impl fmt::Display for IntTy {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", self.ty_to_string())
}
}
impl IntTy {
pub fn ty_to_string(&self) -> &'static str {
match *self {
IntTy::Isize => "isize",
IntTy::I8 => "i8",
IntTy::I16 => "i16",
IntTy::I32 => "i32",
IntTy::I64 => "i64",
IntTy::I128 => "i128",
}
}
pub fn to_symbol(&self) -> Symbol {
match *self {
IntTy::Isize => sym::isize,
IntTy::I8 => sym::i8,
IntTy::I16 => sym::i16,
IntTy::I32 => sym::i32,
IntTy::I64 => sym::i64,
IntTy::I128 => sym::i128,
}
}
pub fn val_to_string(&self, val: i128) -> String {
// Cast to a `u128` so we can correctly print `INT128_MIN`. All integral types
// are parsed as `u128`, so we wouldn't want to print an extra negative
// sign.
format!("{}{}", val as u128, self.ty_to_string())
}
pub fn bit_width(&self) -> Option<usize> {
Some(match *self {
IntTy::Isize => return None,
IntTy::I8 => 8,
IntTy::I16 => 16,
IntTy::I32 => 32,
IntTy::I64 => 64,
IntTy::I128 => 128,
})
}
}
#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable, Copy)]
pub enum UintTy {
Usize,
U8,
U16,
U32,
U64,
U128,
}
impl UintTy {
pub fn ty_to_string(&self) -> &'static str {
match *self {
UintTy::Usize => "usize",
UintTy::U8 => "u8",
UintTy::U16 => "u16",
UintTy::U32 => "u32",
UintTy::U64 => "u64",
UintTy::U128 => "u128",
}
}
pub fn to_symbol(&self) -> Symbol {
match *self {
UintTy::Usize => sym::usize,
UintTy::U8 => sym::u8,
UintTy::U16 => sym::u16,
UintTy::U32 => sym::u32,
UintTy::U64 => sym::u64,
UintTy::U128 => sym::u128,
}
}
pub fn val_to_string(&self, val: u128) -> String {
format!("{}{}", val, self.ty_to_string())
}
pub fn bit_width(&self) -> Option<usize> {
Some(match *self {
UintTy::Usize => return None,
UintTy::U8 => 8,
UintTy::U16 => 16,
UintTy::U32 => 32,
UintTy::U64 => 64,
UintTy::U128 => 128,
})
}
}
impl fmt::Debug for UintTy {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(self, f)
}
}
impl fmt::Display for UintTy {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}", self.ty_to_string())
}
}
/// A constraint on an associated type (e.g., `A = Bar` in `Foo<A = Bar>` or
/// `A: TraitA + TraitB` in `Foo<A: TraitA + TraitB>`).
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct AssocTyConstraint {
pub id: NodeId,
pub ident: Ident,
pub kind: AssocTyConstraintKind,
pub span: Span,
}
/// The kinds of an `AssocTyConstraint`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum AssocTyConstraintKind {
/// E.g., `A = Bar` in `Foo<A = Bar>`.
Equality {
ty: P<Ty>,
},
/// E.g. `A: TraitA + TraitB` in `Foo<A: TraitA + TraitB>`.
Bound {
bounds: GenericBounds,
},
}
#[derive(Clone, RustcEncodable, RustcDecodable)]
pub struct Ty {
pub id: NodeId,
pub node: TyKind,
pub span: Span,
}
impl fmt::Debug for Ty {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "type({})", pprust::ty_to_string(self))
}
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct BareFnTy {
pub unsafety: Unsafety,
pub abi: Abi,
pub generic_params: Vec<GenericParam>,
pub decl: P<FnDecl>,
}
/// The various kinds of type recognized by the compiler.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum TyKind {
/// A variable-length slice (`[T]`).
Slice(P<Ty>),
/// A fixed length array (`[T; n]`).
Array(P<Ty>, AnonConst),
/// A raw pointer (`*const T` or `*mut T`).
Ptr(MutTy),
/// A reference (`&'a T` or `&'a mut T`).
Rptr(Option<Lifetime>, MutTy),
/// A bare function (e.g., `fn(usize) -> bool`).
BareFn(P<BareFnTy>),
/// The never type (`!`).
Never,
/// A tuple (`(A, B, C, D,...)`).
Tup(Vec<P<Ty>>),
/// A path (`module::module::...::Type`), optionally
/// "qualified", e.g., `<Vec<T> as SomeTrait>::SomeType`.
///
/// Type parameters are stored in the `Path` itself.
Path(Option<QSelf>, Path),
/// A trait object type `Bound1 + Bound2 + Bound3`
/// where `Bound` is a trait or a lifetime.
TraitObject(GenericBounds, TraitObjectSyntax),
/// An `impl Bound1 + Bound2 + Bound3` type
/// where `Bound` is a trait or a lifetime.
///
/// The `NodeId` exists to prevent lowering from having to
/// generate `NodeId`s on the fly, which would complicate
/// the generation of opaque `type Foo = impl Trait` items significantly.
ImplTrait(NodeId, GenericBounds),
/// No-op; kept solely so that we can pretty-print faithfully.
Paren(P<Ty>),
/// Unused for now.
Typeof(AnonConst),
/// This means the type should be inferred instead of it having been
/// specified. This can appear anywhere in a type.
Infer,
/// Inferred type of a `self` or `&self` argument in a method.
ImplicitSelf,
/// A macro in the type position.
Mac(Mac),
/// Placeholder for a kind that has failed to be defined.
Err,
/// Placeholder for a `va_list`.
CVarArgs,
}
impl TyKind {
pub fn is_implicit_self(&self) -> bool {
if let TyKind::ImplicitSelf = *self {
true
} else {
false
}
}
pub fn is_unit(&self) -> bool {
if let TyKind::Tup(ref tys) = *self {
tys.is_empty()
} else {
false
}
}
}
/// Syntax used to declare a trait object.
#[derive(Clone, Copy, PartialEq, RustcEncodable, RustcDecodable, Debug)]
pub enum TraitObjectSyntax {
Dyn,
None,
}
/// Inline assembly dialect.
///
/// E.g., `"intel"` as in `asm!("mov eax, 2" : "={eax}"(result) : : : "intel")`.
#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
pub enum AsmDialect {
Att,
Intel,
}
/// Inline assembly.
///
/// E.g., `"={eax}"(result)` as in `asm!("mov eax, 2" : "={eax}"(result) : : : "intel")`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct InlineAsmOutput {
pub constraint: Symbol,
pub expr: P<Expr>,
pub is_rw: bool,
pub is_indirect: bool,
}
/// Inline assembly.
///
/// E.g., `asm!("NOP");`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct InlineAsm {
pub asm: Symbol,
pub asm_str_style: StrStyle,
pub outputs: Vec<InlineAsmOutput>,
pub inputs: Vec<(Symbol, P<Expr>)>,
pub clobbers: Vec<Symbol>,
pub volatile: bool,
pub alignstack: bool,
pub dialect: AsmDialect,
}
/// A parameter in a function header.
///
/// E.g., `bar: usize` as in `fn foo(bar: usize)`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct Param {
pub attrs: ThinVec<Attribute>,
pub ty: P<Ty>,
pub pat: P<Pat>,
pub id: NodeId,
pub span: Span,
}
/// Alternative representation for `Arg`s describing `self` parameter of methods.
///
/// E.g., `&mut self` as in `fn foo(&mut self)`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum SelfKind {
/// `self`, `mut self`
Value(Mutability),
/// `&'lt self`, `&'lt mut self`
Region(Option<Lifetime>, Mutability),
/// `self: TYPE`, `mut self: TYPE`
Explicit(P<Ty>, Mutability),
}
pub type ExplicitSelf = Spanned<SelfKind>;
impl Param {
pub fn to_self(&self) -> Option<ExplicitSelf> {
if let PatKind::Ident(BindingMode::ByValue(mutbl), ident, _) = self.pat.node {
if ident.name == kw::SelfLower {
return match self.ty.node {
TyKind::ImplicitSelf => Some(respan(self.pat.span, SelfKind::Value(mutbl))),
TyKind::Rptr(lt, MutTy { ref ty, mutbl }) if ty.node.is_implicit_self() => {
Some(respan(self.pat.span, SelfKind::Region(lt, mutbl)))
}
_ => Some(respan(
self.pat.span.to(self.ty.span),
SelfKind::Explicit(self.ty.clone(), mutbl),
)),
};
}
}
None
}
pub fn is_self(&self) -> bool {
if let PatKind::Ident(_, ident, _) = self.pat.node {
ident.name == kw::SelfLower
} else {
false
}
}
pub fn from_self(attrs: ThinVec<Attribute>, eself: ExplicitSelf, eself_ident: Ident) -> Param {
let span = eself.span.to(eself_ident.span);
let infer_ty = P(Ty {
id: DUMMY_NODE_ID,
node: TyKind::ImplicitSelf,
span,
});
let param = |mutbl, ty| Param {
attrs,
pat: P(Pat {
id: DUMMY_NODE_ID,
node: PatKind::Ident(BindingMode::ByValue(mutbl), eself_ident, None),
span,
}),
span,
ty,
id: DUMMY_NODE_ID,
};
match eself.node {
SelfKind::Explicit(ty, mutbl) => param(mutbl, ty),
SelfKind::Value(mutbl) => param(mutbl, infer_ty),
SelfKind::Region(lt, mutbl) => param(
Mutability::Immutable,
P(Ty {
id: DUMMY_NODE_ID,
node: TyKind::Rptr(
lt,
MutTy {
ty: infer_ty,
mutbl,
},
),
span,
}),
),
}
}
}
/// A header (not the body) of a function declaration.
///
/// E.g., `fn foo(bar: baz)`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct FnDecl {
pub inputs: Vec<Param>,
pub output: FunctionRetTy,
pub c_variadic: bool,
}
impl FnDecl {
pub fn get_self(&self) -> Option<ExplicitSelf> {
self.inputs.get(0).and_then(Param::to_self)
}
pub fn has_self(&self) -> bool {
self.inputs.get(0).map(Param::is_self).unwrap_or(false)
}
}
/// Is the trait definition an auto trait?
#[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
pub enum IsAuto {
Yes,
No,
}
#[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
pub enum Unsafety {
Unsafe,
Normal,
}
#[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum IsAsync {
Async {
closure_id: NodeId,
return_impl_trait_id: NodeId,
},
NotAsync,
}
impl IsAsync {
pub fn is_async(self) -> bool {
if let IsAsync::Async { .. } = self {
true
} else {
false
}
}
/// In ths case this is an `async` return, the `NodeId` for the generated `impl Trait` item.
pub fn opt_return_id(self) -> Option<NodeId> {
match self {
IsAsync::Async {
return_impl_trait_id,
..
} => Some(return_impl_trait_id),
IsAsync::NotAsync => None,
}
}
}
#[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
pub enum Constness {
Const,
NotConst,
}
#[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable, Debug)]
pub enum Defaultness {
Default,
Final,
}
impl fmt::Display for Unsafety {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(
match *self {
Unsafety::Normal => "normal",
Unsafety::Unsafe => "unsafe",
},
f,
)
}
}
#[derive(Copy, Clone, PartialEq, RustcEncodable, RustcDecodable)]
pub enum ImplPolarity {
/// `impl Trait for Type`
Positive,
/// `impl !Trait for Type`
Negative,
}
impl fmt::Debug for ImplPolarity {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match *self {
ImplPolarity::Positive => "positive".fmt(f),
ImplPolarity::Negative => "negative".fmt(f),
}
}
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum FunctionRetTy {
/// Returns type is not specified.
///
/// Functions default to `()` and closures default to inference.
/// Span points to where return type would be inserted.
Default(Span),
/// Everything else.
Ty(P<Ty>),
}
impl FunctionRetTy {
pub fn span(&self) -> Span {
match *self {
FunctionRetTy::Default(span) => span,
FunctionRetTy::Ty(ref ty) => ty.span,
}
}
}
/// Module declaration.
///
/// E.g., `mod foo;` or `mod foo { .. }`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct Mod {
/// A span from the first token past `{` to the last token until `}`.
/// For `mod foo;`, the inner span ranges from the first token
/// to the last token in the external file.
pub inner: Span,
pub items: Vec<P<Item>>,
/// `true` for `mod foo { .. }`; `false` for `mod foo;`.
pub inline: bool,
}
/// Foreign module declaration.
///
/// E.g., `extern { .. }` or `extern C { .. }`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct ForeignMod {
pub abi: Abi,
pub items: Vec<ForeignItem>,
}
/// Global inline assembly.
///
/// Also known as "module-level assembly" or "file-scoped assembly".
#[derive(Clone, RustcEncodable, RustcDecodable, Debug, Copy)]
pub struct GlobalAsm {
pub asm: Symbol,
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct EnumDef {
pub variants: Vec<Variant>,
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct Variant {
/// Name of the variant.
pub ident: Ident,
/// Attributes of the variant.
pub attrs: Vec<Attribute>,
/// Id of the variant (not the constructor, see `VariantData::ctor_id()`).
pub id: NodeId,
/// Fields and constructor id of the variant.
pub data: VariantData,
/// Explicit discriminant, e.g., `Foo = 1`.
pub disr_expr: Option<AnonConst>,
/// Span
pub span: Span,
}
/// Part of `use` item to the right of its prefix.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum UseTreeKind {
/// `use prefix` or `use prefix as rename`
///
/// The extra `NodeId`s are for HIR lowering, when additional statements are created for each
/// namespace.
Simple(Option<Ident>, NodeId, NodeId),
/// `use prefix::{...}`
Nested(Vec<(UseTree, NodeId)>),
/// `use prefix::*`
Glob,
}
/// A tree of paths sharing common prefixes.
/// Used in `use` items both at top-level and inside of braces in import groups.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct UseTree {
pub prefix: Path,
pub kind: UseTreeKind,
pub span: Span,
}
impl UseTree {
pub fn ident(&self) -> Ident {
match self.kind {
UseTreeKind::Simple(Some(rename), ..) => rename,
UseTreeKind::Simple(None, ..) => {
self.prefix
.segments
.last()
.expect("empty prefix in a simple import")
.ident
}
_ => panic!("`UseTree::ident` can only be used on a simple import"),
}
}
}
/// Distinguishes between `Attribute`s that decorate items and Attributes that
/// are contained as statements within items. These two cases need to be
/// distinguished for pretty-printing.
#[derive(Clone, PartialEq, RustcEncodable, RustcDecodable, Debug, Copy)]
pub enum AttrStyle {
Outer,
Inner,
}
#[derive(Clone, PartialEq, Eq, Hash, Debug, PartialOrd, Ord, Copy)]
pub struct AttrId(pub usize);
impl Idx for AttrId {
fn new(idx: usize) -> Self {
AttrId(idx)
}
fn index(self) -> usize {
self.0
}
}
impl rustc_serialize::Encodable for AttrId {
fn encode<S: Encoder>(&self, s: &mut S) -> Result<(), S::Error> {
s.emit_unit()
}
}
impl rustc_serialize::Decodable for AttrId {
fn decode<D: Decoder>(d: &mut D) -> Result<AttrId, D::Error> {
d.read_nil().map(|_| crate::attr::mk_attr_id())
}
}
/// Metadata associated with an item.
/// Doc-comments are promoted to attributes that have `is_sugared_doc = true`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct Attribute {
pub id: AttrId,
pub style: AttrStyle,
pub path: Path,
pub tokens: TokenStream,
pub is_sugared_doc: bool,
pub span: Span,
}
/// `TraitRef`s appear in impls.
///
/// Resolution maps each `TraitRef`'s `ref_id` to its defining trait; that's all
/// that the `ref_id` is for. The `impl_id` maps to the "self type" of this impl.
/// If this impl is an `ItemKind::Impl`, the `impl_id` is redundant (it could be the
/// same as the impl's `NodeId`).
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct TraitRef {
pub path: Path,
pub ref_id: NodeId,
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct PolyTraitRef {
/// The `'a` in `<'a> Foo<&'a T>`.
pub bound_generic_params: Vec<GenericParam>,
/// The `Foo<&'a T>` in `<'a> Foo<&'a T>`.
pub trait_ref: TraitRef,
pub span: Span,
}
impl PolyTraitRef {
pub fn new(generic_params: Vec<GenericParam>, path: Path, span: Span) -> Self {
PolyTraitRef {
bound_generic_params: generic_params,
trait_ref: TraitRef {
path,
ref_id: DUMMY_NODE_ID,
},
span,
}
}
}
#[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum CrateSugar {
/// Source is `pub(crate)`.
PubCrate,
/// Source is (just) `crate`.
JustCrate,
}
pub type Visibility = Spanned<VisibilityKind>;
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum VisibilityKind {
Public,
Crate(CrateSugar),
Restricted { path: P<Path>, id: NodeId },
Inherited,
}
impl VisibilityKind {
pub fn is_pub(&self) -> bool {
if let VisibilityKind::Public = *self {
true
} else {
false
}
}
}
/// Field of a struct.
///
/// E.g., `bar: usize` as in `struct Foo { bar: usize }`.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct StructField {
pub span: Span,
pub ident: Option<Ident>,
pub vis: Visibility,
pub id: NodeId,
pub ty: P<Ty>,
pub attrs: Vec<Attribute>,
}
/// Fields and constructor ids of enum variants and structs.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum VariantData {
/// Struct variant.
///
/// E.g., `Bar { .. }` as in `enum Foo { Bar { .. } }`.
Struct(Vec<StructField>, bool),
/// Tuple variant.
///
/// E.g., `Bar(..)` as in `enum Foo { Bar(..) }`.
Tuple(Vec<StructField>, NodeId),
/// Unit variant.
///
/// E.g., `Bar = ..` as in `enum Foo { Bar = .. }`.
Unit(NodeId),
}
impl VariantData {
/// Return the fields of this variant.
pub fn fields(&self) -> &[StructField] {
match *self {
VariantData::Struct(ref fields, ..) | VariantData::Tuple(ref fields, _) => fields,
_ => &[],
}
}
/// Return the `NodeId` of this variant's constructor, if it has one.
pub fn ctor_id(&self) -> Option<NodeId> {
match *self {
VariantData::Struct(..) => None,
VariantData::Tuple(_, id) | VariantData::Unit(id) => Some(id),
}
}
}
/// An item.
///
/// The name might be a dummy name in case of anonymous items.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct Item {
pub ident: Ident,
pub attrs: Vec<Attribute>,
pub id: NodeId,
pub node: ItemKind,
pub vis: Visibility,
pub span: Span,
/// Original tokens this item was parsed from. This isn't necessarily
/// available for all items, although over time more and more items should
/// have this be `Some`. Right now this is primarily used for procedural
/// macros, notably custom attributes.
///
/// Note that the tokens here do not include the outer attributes, but will
/// include inner attributes.
pub tokens: Option<TokenStream>,
}
impl Item {
/// Return the span that encompasses the attributes.
pub fn span_with_attributes(&self) -> Span {
self.attrs.iter().fold(self.span, |acc, attr| acc.to(attr.span))
}
}
/// A function header.
///
/// All the information between the visibility and the name of the function is
/// included in this struct (e.g., `async unsafe fn` or `const extern "C" fn`).
#[derive(Clone, Copy, RustcEncodable, RustcDecodable, Debug)]
pub struct FnHeader {
pub unsafety: Unsafety,
pub asyncness: Spanned<IsAsync>,
pub constness: Spanned<Constness>,
pub abi: Abi,
}
impl Default for FnHeader {
fn default() -> FnHeader {
FnHeader {
unsafety: Unsafety::Normal,
asyncness: dummy_spanned(IsAsync::NotAsync),
constness: dummy_spanned(Constness::NotConst),
abi: Abi::Rust,
}
}
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum ItemKind {
/// An `extern crate` item, with the optional *original* crate name if the crate was renamed.
///
/// E.g., `extern crate foo` or `extern crate foo_bar as foo`.
ExternCrate(Option<Name>),
/// A use declaration item (`use`).
///
/// E.g., `use foo;`, `use foo::bar;` or `use foo::bar as FooBar;`.
Use(P<UseTree>),
/// A static item (`static`).
///
/// E.g., `static FOO: i32 = 42;` or `static FOO: &'static str = "bar";`.
Static(P<Ty>, Mutability, P<Expr>),
/// A constant item (`const`).
///
/// E.g., `const FOO: i32 = 42;`.
Const(P<Ty>, P<Expr>),
/// A function declaration (`fn`).
///
/// E.g., `fn foo(bar: usize) -> usize { .. }`.
Fn(P<FnDecl>, FnHeader, Generics, P<Block>),
/// A module declaration (`mod`).
///
/// E.g., `mod foo;` or `mod foo { .. }`.
Mod(Mod),
/// An external module (`extern`).
///
/// E.g., `extern {}` or `extern "C" {}`.
ForeignMod(ForeignMod),
/// Module-level inline assembly (from `global_asm!()`).
GlobalAsm(P<GlobalAsm>),
/// A type alias (`type`).
///
/// E.g., `type Foo = Bar<u8>;`.
TyAlias(P<Ty>, Generics),
/// An opaque `impl Trait` type alias.
///
/// E.g., `type Foo = impl Bar + Boo;`.
OpaqueTy(GenericBounds, Generics),
/// An enum definition (`enum`).
///
/// E.g., `enum Foo<A, B> { C<A>, D<B> }`.
Enum(EnumDef, Generics),
/// A struct definition (`struct`).
///
/// E.g., `struct Foo<A> { x: A }`.
Struct(VariantData, Generics),
/// A union definition (`union`).
///
/// E.g., `union Foo<A, B> { x: A, y: B }`.
Union(VariantData, Generics),
/// A trait declaration (`trait`).
///
/// E.g., `trait Foo { .. }`, `trait Foo<T> { .. }` or `auto trait Foo {}`.
Trait(IsAuto, Unsafety, Generics, GenericBounds, Vec<TraitItem>),
/// Trait alias
///
/// E.g., `trait Foo = Bar + Quux;`.
TraitAlias(Generics, GenericBounds),
/// An implementation.
///
/// E.g., `impl<A> Foo<A> { .. }` or `impl<A> Trait for Foo<A> { .. }`.
Impl(
Unsafety,
ImplPolarity,
Defaultness,
Generics,
Option<TraitRef>, // (optional) trait this impl implements
P<Ty>, // self
Vec<ImplItem>,
),
/// A macro invocation.
///
/// E.g., `macro_rules! foo { .. }` or `foo!(..)`.
Mac(Mac),
/// A macro definition.
MacroDef(MacroDef),
}
impl ItemKind {
pub fn descriptive_variant(&self) -> &str {
match *self {
ItemKind::ExternCrate(..) => "extern crate",
ItemKind::Use(..) => "use",
ItemKind::Static(..) => "static item",
ItemKind::Const(..) => "constant item",
ItemKind::Fn(..) => "function",
ItemKind::Mod(..) => "module",
ItemKind::ForeignMod(..) => "foreign module",
ItemKind::GlobalAsm(..) => "global asm",
ItemKind::TyAlias(..) => "type alias",
ItemKind::OpaqueTy(..) => "opaque type",
ItemKind::Enum(..) => "enum",
ItemKind::Struct(..) => "struct",
ItemKind::Union(..) => "union",
ItemKind::Trait(..) => "trait",
ItemKind::TraitAlias(..) => "trait alias",
ItemKind::Mac(..) | ItemKind::MacroDef(..) | ItemKind::Impl(..) => "item",
}
}
}
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub struct ForeignItem {
pub ident: Ident,
pub attrs: Vec<Attribute>,
pub node: ForeignItemKind,
pub id: NodeId,
pub span: Span,
pub vis: Visibility,
}
/// An item within an `extern` block.
#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
pub enum ForeignItemKind {
/// A foreign function.
Fn(P<FnDecl>, Generics),
/// A foreign static item (`static ext: u8`).
Static(P<Ty>, Mutability),
/// A foreign type.
Ty,
/// A macro invocation.
Macro(Mac),
}
impl ForeignItemKind {
pub fn descriptive_variant(&self) -> &str {
match *self {
ForeignItemKind::Fn(..) => "foreign function",
ForeignItemKind::Static(..) => "foreign static item",
ForeignItemKind::Ty => "foreign type",
ForeignItemKind::Macro(..) => "macro in foreign module",
}
}
}