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os-rust/compiler/rustc_hir/src/hir.rs
bors aaef5fe497 Auto merge of #119163 - fmease:refactor-ast-trait-bound-modifiers, r=compiler-errors 
Refactor AST trait bound modifiers

Instead of having two types to represent trait bound modifiers in the parser / the AST (`parser::ty::BoundModifiers` & `ast::TraitBoundModifier`), only to map one to the other later, just use `parser::ty::BoundModifiers` (moved & renamed to `ast::TraitBoundModifiers`).

The struct type is more extensible and easier to deal with (see [here](https://github.com/rust-lang/rust/pull/119099/files#r1430749981) and [here](https://github.com/rust-lang/rust/pull/119099/files#r1430752116) for context) since it more closely models what it represents: A compound of two kinds of modifiers, constness and polarity. Modeling this as an enum (the now removed `ast::TraitBoundModifier`) meant one had to add a new variant per *combination* of modifier kind, which simply isn't scalable and which lead to a lot of explicit non-DRY matches.

NB: `hir::TraitBoundModifier` being an enum is fine since HIR doesn't need to worry representing invalid modifier kind combinations as those get rejected during AST validation thereby immensely cutting down the number of possibilities.
2023-12-22 02:00:55 +00:00

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use crate::def::{CtorKind, DefKind, Res};
use crate::def_id::{DefId, LocalDefIdMap};
pub(crate) use crate::hir_id::{HirId, ItemLocalId, ItemLocalMap, OwnerId};
use crate::intravisit::FnKind;
use crate::LangItem;
use rustc_ast as ast;
use rustc_ast::util::parser::ExprPrecedence;
use rustc_ast::{Attribute, FloatTy, IntTy, Label, LitKind, TraitObjectSyntax, UintTy};
pub use rustc_ast::{BinOp, BinOpKind, BindingAnnotation, BorrowKind, ByRef, CaptureBy};
pub use rustc_ast::{ImplPolarity, IsAuto, Movability, Mutability, UnOp};
use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
use rustc_data_structures::fingerprint::Fingerprint;
use rustc_data_structures::sorted_map::SortedMap;
use rustc_index::IndexVec;
use rustc_macros::HashStable_Generic;
use rustc_span::hygiene::MacroKind;
use rustc_span::source_map::Spanned;
use rustc_span::symbol::{kw, sym, Ident, Symbol};
use rustc_span::ErrorGuaranteed;
use rustc_span::{def_id::LocalDefId, BytePos, Span, DUMMY_SP};
use rustc_target::asm::InlineAsmRegOrRegClass;
use rustc_target::spec::abi::Abi;
use smallvec::SmallVec;
use std::fmt;
#[derive(Debug, Copy, Clone, HashStable_Generic)]
pub struct Lifetime {
pub hir_id: HirId,
/// Either "`'a`", referring to a named lifetime definition,
/// `'_` referring to an anonymous lifetime (either explicitly `'_` or `&type`),
/// or "``" (i.e., `kw::Empty`) when appearing in path.
///
/// See `Lifetime::suggestion_position` for practical use.
pub ident: Ident,
/// Semantics of this lifetime.
pub res: LifetimeName,
}
#[derive(Debug, Copy, Clone, HashStable_Generic)]
pub enum ParamName {
/// Some user-given name like `T` or `'x`.
Plain(Ident),
/// Synthetic name generated when user elided a lifetime in an impl header.
///
/// E.g., the lifetimes in cases like these:
/// ```ignore (fragment)
/// impl Foo for &u32
/// impl Foo<'_> for u32
/// ```
/// in that case, we rewrite to
/// ```ignore (fragment)
/// impl<'f> Foo for &'f u32
/// impl<'f> Foo<'f> for u32
/// ```
/// where `'f` is something like `Fresh(0)`. The indices are
/// unique per impl, but not necessarily continuous.
Fresh,
/// Indicates an illegal name was given and an error has been
/// reported (so we should squelch other derived errors). Occurs
/// when, e.g., `'_` is used in the wrong place.
Error,
}
impl ParamName {
pub fn ident(&self) -> Ident {
match *self {
ParamName::Plain(ident) => ident,
ParamName::Fresh | ParamName::Error => Ident::with_dummy_span(kw::UnderscoreLifetime),
}
}
}
#[derive(Debug, Copy, Clone, PartialEq, Eq, HashStable_Generic)]
pub enum LifetimeName {
/// User-given names or fresh (synthetic) names.
Param(LocalDefId),
/// Implicit lifetime in a context like `dyn Foo`. This is
/// distinguished from implicit lifetimes elsewhere because the
/// lifetime that they default to must appear elsewhere within the
/// enclosing type. This means that, in an `impl Trait` context, we
/// don't have to create a parameter for them. That is, `impl
/// Trait<Item = &u32>` expands to an opaque type like `type
/// Foo<'a> = impl Trait<Item = &'a u32>`, but `impl Trait<item =
/// dyn Bar>` expands to `type Foo = impl Trait<Item = dyn Bar +
/// 'static>`. The latter uses `ImplicitObjectLifetimeDefault` so
/// that surrounding code knows not to create a lifetime
/// parameter.
ImplicitObjectLifetimeDefault,
/// Indicates an error during lowering (usually `'_` in wrong place)
/// that was already reported.
Error,
/// User wrote an anonymous lifetime, either `'_` or nothing.
/// The semantics of this lifetime should be inferred by typechecking code.
Infer,
/// User wrote `'static`.
Static,
}
impl LifetimeName {
fn is_elided(&self) -> bool {
match self {
LifetimeName::ImplicitObjectLifetimeDefault | LifetimeName::Infer => true,
// It might seem surprising that `Fresh` counts as not *elided*
// -- but this is because, as far as the code in the compiler is
// concerned -- `Fresh` variants act equivalently to "some fresh name".
// They correspond to early-bound regions on an impl, in other words.
LifetimeName::Error | LifetimeName::Param(..) | LifetimeName::Static => false,
}
}
}
impl fmt::Display for Lifetime {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
if self.ident.name != kw::Empty { self.ident.name.fmt(f) } else { "'_".fmt(f) }
}
}
pub enum LifetimeSuggestionPosition {
/// The user wrote `'a` or `'_`.
Normal,
/// The user wrote `&type` or `&mut type`.
Ampersand,
/// The user wrote `Path` and omitted the `<'_>`.
ElidedPath,
/// The user wrote `Path<T>`, and omitted the `'_,`.
ElidedPathArgument,
/// The user wrote `dyn Trait` and omitted the `+ '_`.
ObjectDefault,
}
impl Lifetime {
pub fn is_elided(&self) -> bool {
self.res.is_elided()
}
pub fn is_anonymous(&self) -> bool {
self.ident.name == kw::Empty || self.ident.name == kw::UnderscoreLifetime
}
pub fn suggestion_position(&self) -> (LifetimeSuggestionPosition, Span) {
if self.ident.name == kw::Empty {
if self.ident.span.is_empty() {
(LifetimeSuggestionPosition::ElidedPathArgument, self.ident.span)
} else {
(LifetimeSuggestionPosition::ElidedPath, self.ident.span.shrink_to_hi())
}
} else if self.res == LifetimeName::ImplicitObjectLifetimeDefault {
(LifetimeSuggestionPosition::ObjectDefault, self.ident.span)
} else if self.ident.span.is_empty() {
(LifetimeSuggestionPosition::Ampersand, self.ident.span)
} else {
(LifetimeSuggestionPosition::Normal, self.ident.span)
}
}
pub fn is_static(&self) -> bool {
self.res == LifetimeName::Static
}
}
/// A `Path` is essentially Rust's notion of a name; for instance,
/// `std::cmp::PartialEq`. It's represented as a sequence of identifiers,
/// along with a bunch of supporting information.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Path<'hir, R = Res> {
pub span: Span,
/// The resolution for the path.
pub res: R,
/// The segments in the path: the things separated by `::`.
pub segments: &'hir [PathSegment<'hir>],
}
/// Up to three resolutions for type, value and macro namespaces.
pub type UsePath<'hir> = Path<'hir, SmallVec<[Res; 3]>>;
impl Path<'_> {
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.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct PathSegment<'hir> {
/// The identifier portion of this path segment.
pub ident: Ident,
pub hir_id: HirId,
pub res: Res,
/// Type/lifetime parameters attached to this path. They come in
/// two flavors: `Path<A,B,C>` and `Path(A,B) -> C`. Note that
/// this is more than just simple syntactic sugar; the use of
/// parens affects the region binding rules, so we preserve the
/// distinction.
pub args: Option<&'hir GenericArgs<'hir>>,
/// Whether to infer remaining type parameters, if any.
/// This only applies to expression and pattern paths, and
/// out of those only the segments with no type parameters
/// to begin with, e.g., `Vec::new` is `<Vec<..>>::new::<..>`.
pub infer_args: bool,
}
impl<'hir> PathSegment<'hir> {
/// Converts an identifier to the corresponding segment.
pub fn new(ident: Ident, hir_id: HirId, res: Res) -> PathSegment<'hir> {
PathSegment { ident, hir_id, res, infer_args: true, args: None }
}
pub fn invalid() -> Self {
Self::new(Ident::empty(), HirId::INVALID, Res::Err)
}
pub fn args(&self) -> &GenericArgs<'hir> {
if let Some(ref args) = self.args {
args
} else {
const DUMMY: &GenericArgs<'_> = &GenericArgs::none();
DUMMY
}
}
}
#[derive(Clone, Copy, Debug, HashStable_Generic)]
pub struct ConstArg {
pub value: AnonConst,
pub span: Span,
/// Indicates whether this comes from a `~const` desugaring.
pub is_desugared_from_effects: bool,
}
#[derive(Clone, Copy, Debug, HashStable_Generic)]
pub struct InferArg {
pub hir_id: HirId,
pub span: Span,
}
impl InferArg {
pub fn to_ty(&self) -> Ty<'_> {
Ty { kind: TyKind::Infer, span: self.span, hir_id: self.hir_id }
}
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum GenericArg<'hir> {
Lifetime(&'hir Lifetime),
Type(&'hir Ty<'hir>),
Const(ConstArg),
Infer(InferArg),
}
impl GenericArg<'_> {
pub fn span(&self) -> Span {
match self {
GenericArg::Lifetime(l) => l.ident.span,
GenericArg::Type(t) => t.span,
GenericArg::Const(c) => c.span,
GenericArg::Infer(i) => i.span,
}
}
pub fn hir_id(&self) -> HirId {
match self {
GenericArg::Lifetime(l) => l.hir_id,
GenericArg::Type(t) => t.hir_id,
GenericArg::Const(c) => c.value.hir_id,
GenericArg::Infer(i) => i.hir_id,
}
}
pub fn descr(&self) -> &'static str {
match self {
GenericArg::Lifetime(_) => "lifetime",
GenericArg::Type(_) => "type",
GenericArg::Const(_) => "constant",
GenericArg::Infer(_) => "inferred",
}
}
pub fn to_ord(&self) -> ast::ParamKindOrd {
match self {
GenericArg::Lifetime(_) => ast::ParamKindOrd::Lifetime,
GenericArg::Type(_) | GenericArg::Const(_) | GenericArg::Infer(_) => {
ast::ParamKindOrd::TypeOrConst
}
}
}
pub fn is_ty_or_const(&self) -> bool {
match self {
GenericArg::Lifetime(_) => false,
GenericArg::Type(_) | GenericArg::Const(_) | GenericArg::Infer(_) => true,
}
}
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct GenericArgs<'hir> {
/// The generic arguments for this path segment.
pub args: &'hir [GenericArg<'hir>],
/// Bindings (equality constraints) on associated types, if present.
/// E.g., `Foo<A = Bar>`.
pub bindings: &'hir [TypeBinding<'hir>],
/// Were arguments written in parenthesized form `Fn(T) -> U`?
/// This is required mostly for pretty-printing and diagnostics,
/// but also for changing lifetime elision rules to be "function-like".
pub parenthesized: GenericArgsParentheses,
/// The span encompassing arguments and the surrounding brackets `<>` or `()`
/// Foo<A, B, AssocTy = D> Fn(T, U, V) -> W
/// ^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^
/// Note that this may be:
/// - empty, if there are no generic brackets (but there may be hidden lifetimes)
/// - dummy, if this was generated while desugaring
pub span_ext: Span,
}
impl<'hir> GenericArgs<'hir> {
pub const fn none() -> Self {
Self {
args: &[],
bindings: &[],
parenthesized: GenericArgsParentheses::No,
span_ext: DUMMY_SP,
}
}
pub fn inputs(&self) -> &[Ty<'hir>] {
if self.parenthesized == GenericArgsParentheses::ParenSugar {
for arg in self.args {
match arg {
GenericArg::Lifetime(_) => {}
GenericArg::Type(ref ty) => {
if let TyKind::Tup(ref tys) = ty.kind {
return tys;
}
break;
}
GenericArg::Const(_) => {}
GenericArg::Infer(_) => {}
}
}
}
panic!("GenericArgs::inputs: not a `Fn(T) -> U`");
}
pub fn has_err(&self) -> bool {
self.args.iter().any(|arg| match arg {
GenericArg::Type(ty) => matches!(ty.kind, TyKind::Err(_)),
_ => false,
}) || self.bindings.iter().any(|arg| match arg.kind {
TypeBindingKind::Equality { term: Term::Ty(ty) } => matches!(ty.kind, TyKind::Err(_)),
_ => false,
})
}
#[inline]
pub fn num_lifetime_params(&self) -> usize {
self.args.iter().filter(|arg| matches!(arg, GenericArg::Lifetime(_))).count()
}
#[inline]
pub fn has_lifetime_params(&self) -> bool {
self.args.iter().any(|arg| matches!(arg, GenericArg::Lifetime(_)))
}
#[inline]
/// This function returns the number of type and const generic params.
/// It should only be used for diagnostics.
pub fn num_generic_params(&self) -> usize {
self.args
.iter()
.filter(|arg| match arg {
GenericArg::Lifetime(_)
| GenericArg::Const(ConstArg { is_desugared_from_effects: true, .. }) => false,
_ => true,
})
.count()
}
/// The span encompassing the text inside the surrounding brackets.
/// It will also include bindings if they aren't in the form `-> Ret`
/// Returns `None` if the span is empty (e.g. no brackets) or dummy
pub fn span(&self) -> Option<Span> {
let span_ext = self.span_ext()?;
Some(span_ext.with_lo(span_ext.lo() + BytePos(1)).with_hi(span_ext.hi() - BytePos(1)))
}
/// Returns span encompassing arguments and their surrounding `<>` or `()`
pub fn span_ext(&self) -> Option<Span> {
Some(self.span_ext).filter(|span| !span.is_empty())
}
pub fn is_empty(&self) -> bool {
self.args.is_empty()
}
}
#[derive(Copy, Clone, PartialEq, Eq, Debug, HashStable_Generic)]
pub enum GenericArgsParentheses {
No,
/// Bounds for `feature(return_type_notation)`, like `T: Trait<method(..): Send>`,
/// where the args are explicitly elided with `..`
ReturnTypeNotation,
/// parenthesized function-family traits, like `T: Fn(u32) -> i32`
ParenSugar,
}
/// A modifier on a trait bound.
#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, HashStable_Generic)]
pub enum TraitBoundModifier {
None,
Negative,
Maybe,
MaybeConst,
}
/// 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, Copy, Debug, HashStable_Generic)]
pub enum GenericBound<'hir> {
Trait(PolyTraitRef<'hir>, TraitBoundModifier),
Outlives(&'hir Lifetime),
}
impl GenericBound<'_> {
pub fn trait_ref(&self) -> Option<&TraitRef<'_>> {
match self {
GenericBound::Trait(data, _) => Some(&data.trait_ref),
_ => None,
}
}
pub fn span(&self) -> Span {
match self {
GenericBound::Trait(t, ..) => t.span,
GenericBound::Outlives(l) => l.ident.span,
}
}
}
pub type GenericBounds<'hir> = &'hir [GenericBound<'hir>];
#[derive(Copy, Clone, Debug, HashStable_Generic)]
pub enum LifetimeParamKind {
// Indicates that the lifetime definition was explicitly declared (e.g., in
// `fn foo<'a>(x: &'a u8) -> &'a u8 { x }`).
Explicit,
// Indication that the lifetime was elided (e.g., in both cases in
// `fn foo(x: &u8) -> &'_ u8 { x }`).
Elided,
// Indication that the lifetime name was somehow in error.
Error,
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum GenericParamKind<'hir> {
/// A lifetime definition (e.g., `'a: 'b + 'c + 'd`).
Lifetime {
kind: LifetimeParamKind,
},
Type {
default: Option<&'hir Ty<'hir>>,
synthetic: bool,
},
Const {
ty: &'hir Ty<'hir>,
/// Optional default value for the const generic param
default: Option<AnonConst>,
is_host_effect: bool,
},
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct GenericParam<'hir> {
pub hir_id: HirId,
pub def_id: LocalDefId,
pub name: ParamName,
pub span: Span,
pub pure_wrt_drop: bool,
pub kind: GenericParamKind<'hir>,
pub colon_span: Option<Span>,
pub source: GenericParamSource,
}
impl<'hir> GenericParam<'hir> {
/// Synthetic type-parameters are inserted after normal ones.
/// In order for normal parameters to be able to refer to synthetic ones,
/// scans them first.
pub fn is_impl_trait(&self) -> bool {
matches!(self.kind, GenericParamKind::Type { synthetic: true, .. })
}
/// This can happen for `async fn`, e.g. `async fn f<'_>(&'_ self)`.
///
/// See `lifetime_to_generic_param` in `rustc_ast_lowering` for more information.
pub fn is_elided_lifetime(&self) -> bool {
matches!(self.kind, GenericParamKind::Lifetime { kind: LifetimeParamKind::Elided })
}
}
/// Records where the generic parameter originated from.
///
/// This can either be from an item's generics, in which case it's typically
/// early-bound (but can be a late-bound lifetime in functions, for example),
/// or from a `for<...>` binder, in which case it's late-bound (and notably,
/// does not show up in the parent item's generics).
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum GenericParamSource {
// Early or late-bound parameters defined on an item
Generics,
// Late-bound parameters defined via a `for<...>`
Binder,
}
#[derive(Default)]
pub struct GenericParamCount {
pub lifetimes: usize,
pub types: usize,
pub consts: usize,
pub infer: usize,
}
/// Represents lifetimes and type parameters attached to a declaration
/// of a function, enum, trait, etc.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Generics<'hir> {
pub params: &'hir [GenericParam<'hir>],
pub predicates: &'hir [WherePredicate<'hir>],
pub has_where_clause_predicates: bool,
pub where_clause_span: Span,
pub span: Span,
}
impl<'hir> Generics<'hir> {
pub const fn empty() -> &'hir Generics<'hir> {
const NOPE: Generics<'_> = Generics {
params: &[],
predicates: &[],
has_where_clause_predicates: false,
where_clause_span: DUMMY_SP,
span: DUMMY_SP,
};
&NOPE
}
pub fn get_named(&self, name: Symbol) -> Option<&GenericParam<'hir>> {
self.params.iter().find(|&param| name == param.name.ident().name)
}
/// If there are generic parameters, return where to introduce a new one.
pub fn span_for_lifetime_suggestion(&self) -> Option<Span> {
if let Some(first) = self.params.first()
&& self.span.contains(first.span)
{
// `fn foo<A>(t: impl Trait)`
// ^ suggest `'a, ` here
Some(first.span.shrink_to_lo())
} else {
None
}
}
/// If there are generic parameters, return where to introduce a new one.
pub fn span_for_param_suggestion(&self) -> Option<Span> {
self.params.iter().any(|p| self.span.contains(p.span)).then(|| {
// `fn foo<A>(t: impl Trait)`
// ^ suggest `, T: Trait` here
self.span.with_lo(self.span.hi() - BytePos(1)).shrink_to_lo()
})
}
/// `Span` where further predicates would be suggested, accounting for trailing commas, like
/// in `fn foo<T>(t: T) where T: Foo,` so we don't suggest two trailing commas.
pub fn tail_span_for_predicate_suggestion(&self) -> Span {
let end = self.where_clause_span.shrink_to_hi();
if self.has_where_clause_predicates {
self.predicates
.iter()
.rfind(|&p| p.in_where_clause())
.map_or(end, |p| p.span())
.shrink_to_hi()
.to(end)
} else {
end
}
}
pub fn add_where_or_trailing_comma(&self) -> &'static str {
if self.has_where_clause_predicates {
","
} else if self.where_clause_span.is_empty() {
" where"
} else {
// No where clause predicates, but we have `where` token
""
}
}
pub fn bounds_for_param(
&self,
param_def_id: LocalDefId,
) -> impl Iterator<Item = &WhereBoundPredicate<'hir>> {
self.predicates.iter().filter_map(move |pred| match pred {
WherePredicate::BoundPredicate(bp) if bp.is_param_bound(param_def_id.to_def_id()) => {
Some(bp)
}
_ => None,
})
}
pub fn outlives_for_param(
&self,
param_def_id: LocalDefId,
) -> impl Iterator<Item = &WhereRegionPredicate<'_>> {
self.predicates.iter().filter_map(move |pred| match pred {
WherePredicate::RegionPredicate(rp) if rp.is_param_bound(param_def_id) => Some(rp),
_ => None,
})
}
pub fn bounds_span_for_suggestions(&self, param_def_id: LocalDefId) -> Option<Span> {
self.bounds_for_param(param_def_id).flat_map(|bp| bp.bounds.iter().rev()).find_map(
|bound| {
// We include bounds that come from a `#[derive(_)]` but point at the user's code,
// as we use this method to get a span appropriate for suggestions.
let bs = bound.span();
bs.can_be_used_for_suggestions().then(|| bs.shrink_to_hi())
},
)
}
fn span_for_predicate_removal(&self, pos: usize) -> Span {
let predicate = &self.predicates[pos];
let span = predicate.span();
if !predicate.in_where_clause() {
// <T: ?Sized, U>
// ^^^^^^^^
return span;
}
// We need to find out which comma to remove.
if pos < self.predicates.len() - 1 {
let next_pred = &self.predicates[pos + 1];
if next_pred.in_where_clause() {
// where T: ?Sized, Foo: Bar,
// ^^^^^^^^^^^
return span.until(next_pred.span());
}
}
if pos > 0 {
let prev_pred = &self.predicates[pos - 1];
if prev_pred.in_where_clause() {
// where Foo: Bar, T: ?Sized,
// ^^^^^^^^^^^
return prev_pred.span().shrink_to_hi().to(span);
}
}
// This is the only predicate in the where clause.
// where T: ?Sized
// ^^^^^^^^^^^^^^^
self.where_clause_span
}
pub fn span_for_bound_removal(&self, predicate_pos: usize, bound_pos: usize) -> Span {
let predicate = &self.predicates[predicate_pos];
let bounds = predicate.bounds();
if bounds.len() == 1 {
return self.span_for_predicate_removal(predicate_pos);
}
let span = bounds[bound_pos].span();
if bound_pos == 0 {
// where T: ?Sized + Bar, Foo: Bar,
// ^^^^^^^^^
span.to(bounds[1].span().shrink_to_lo())
} else {
// where T: Bar + ?Sized, Foo: Bar,
// ^^^^^^^^^
bounds[bound_pos - 1].span().shrink_to_hi().to(span)
}
}
}
/// A single predicate in a where-clause.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum WherePredicate<'hir> {
/// A type binding (e.g., `for<'c> Foo: Send + Clone + 'c`).
BoundPredicate(WhereBoundPredicate<'hir>),
/// A lifetime predicate (e.g., `'a: 'b + 'c`).
RegionPredicate(WhereRegionPredicate<'hir>),
/// An equality predicate (unsupported).
EqPredicate(WhereEqPredicate<'hir>),
}
impl<'hir> WherePredicate<'hir> {
pub fn span(&self) -> Span {
match self {
WherePredicate::BoundPredicate(p) => p.span,
WherePredicate::RegionPredicate(p) => p.span,
WherePredicate::EqPredicate(p) => p.span,
}
}
pub fn in_where_clause(&self) -> bool {
match self {
WherePredicate::BoundPredicate(p) => p.origin == PredicateOrigin::WhereClause,
WherePredicate::RegionPredicate(p) => p.in_where_clause,
WherePredicate::EqPredicate(_) => false,
}
}
pub fn bounds(&self) -> GenericBounds<'hir> {
match self {
WherePredicate::BoundPredicate(p) => p.bounds,
WherePredicate::RegionPredicate(p) => p.bounds,
WherePredicate::EqPredicate(_) => &[],
}
}
}
#[derive(Copy, Clone, Debug, HashStable_Generic, PartialEq, Eq)]
pub enum PredicateOrigin {
WhereClause,
GenericParam,
ImplTrait,
}
/// A type bound (e.g., `for<'c> Foo: Send + Clone + 'c`).
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct WhereBoundPredicate<'hir> {
pub hir_id: HirId,
pub span: Span,
/// Origin of the predicate.
pub origin: PredicateOrigin,
/// Any generics from a `for` binding.
pub bound_generic_params: &'hir [GenericParam<'hir>],
/// The type being bounded.
pub bounded_ty: &'hir Ty<'hir>,
/// Trait and lifetime bounds (e.g., `Clone + Send + 'static`).
pub bounds: GenericBounds<'hir>,
}
impl<'hir> WhereBoundPredicate<'hir> {
/// Returns `true` if `param_def_id` matches the `bounded_ty` of this predicate.
pub fn is_param_bound(&self, param_def_id: DefId) -> bool {
self.bounded_ty.as_generic_param().is_some_and(|(def_id, _)| def_id == param_def_id)
}
}
/// A lifetime predicate (e.g., `'a: 'b + 'c`).
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct WhereRegionPredicate<'hir> {
pub span: Span,
pub in_where_clause: bool,
pub lifetime: &'hir Lifetime,
pub bounds: GenericBounds<'hir>,
}
impl<'hir> WhereRegionPredicate<'hir> {
/// Returns `true` if `param_def_id` matches the `lifetime` of this predicate.
fn is_param_bound(&self, param_def_id: LocalDefId) -> bool {
self.lifetime.res == LifetimeName::Param(param_def_id)
}
}
/// An equality predicate (e.g., `T = int`); currently unsupported.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct WhereEqPredicate<'hir> {
pub span: Span,
pub lhs_ty: &'hir Ty<'hir>,
pub rhs_ty: &'hir Ty<'hir>,
}
/// HIR node coupled with its parent's id in the same HIR owner.
///
/// The parent is trash when the node is a HIR owner.
#[derive(Clone, Copy, Debug)]
pub struct ParentedNode<'tcx> {
pub parent: ItemLocalId,
pub node: Node<'tcx>,
}
/// Attributes owned by a HIR owner.
#[derive(Debug)]
pub struct AttributeMap<'tcx> {
pub map: SortedMap<ItemLocalId, &'tcx [Attribute]>,
// Only present when the crate hash is needed.
pub opt_hash: Option<Fingerprint>,
}
impl<'tcx> AttributeMap<'tcx> {
pub const EMPTY: &'static AttributeMap<'static> =
&AttributeMap { map: SortedMap::new(), opt_hash: Some(Fingerprint::ZERO) };
#[inline]
pub fn get(&self, id: ItemLocalId) -> &'tcx [Attribute] {
self.map.get(&id).copied().unwrap_or(&[])
}
}
/// Map of all HIR nodes inside the current owner.
/// These nodes are mapped by `ItemLocalId` alongside the index of their parent node.
/// The HIR tree, including bodies, is pre-hashed.
pub struct OwnerNodes<'tcx> {
/// Pre-computed hash of the full HIR. Used in the crate hash. Only present
/// when incr. comp. is enabled.
pub opt_hash_including_bodies: Option<Fingerprint>,
/// Full HIR for the current owner.
// The zeroth node's parent should never be accessed: the owner's parent is computed by the
// hir_owner_parent query. It is set to `ItemLocalId::INVALID` to force an ICE if accidentally
// used.
pub nodes: IndexVec<ItemLocalId, Option<ParentedNode<'tcx>>>,
/// Content of local bodies.
pub bodies: SortedMap<ItemLocalId, &'tcx Body<'tcx>>,
}
impl<'tcx> OwnerNodes<'tcx> {
fn node(&self) -> OwnerNode<'tcx> {
use rustc_index::Idx;
let node = self.nodes[ItemLocalId::new(0)].as_ref().unwrap().node;
let node = node.as_owner().unwrap(); // Indexing must ensure it is an OwnerNode.
node
}
}
impl fmt::Debug for OwnerNodes<'_> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_struct("OwnerNodes")
// Do not print all the pointers to all the nodes, as it would be unreadable.
.field("node", &self.nodes[ItemLocalId::from_u32(0)])
.field(
"parents",
&self
.nodes
.iter_enumerated()
.map(|(id, parented_node)| {
let parented_node = parented_node.as_ref().map(|node| node.parent);
debug_fn(move |f| write!(f, "({id:?}, {parented_node:?})"))
})
.collect::<Vec<_>>(),
)
.field("bodies", &self.bodies)
.field("opt_hash_including_bodies", &self.opt_hash_including_bodies)
.finish()
}
}
/// Full information resulting from lowering an AST node.
#[derive(Debug, HashStable_Generic)]
pub struct OwnerInfo<'hir> {
/// Contents of the HIR.
pub nodes: OwnerNodes<'hir>,
/// Map from each nested owner to its parent's local id.
pub parenting: LocalDefIdMap<ItemLocalId>,
/// Collected attributes of the HIR nodes.
pub attrs: AttributeMap<'hir>,
/// Map indicating what traits are in scope for places where this
/// is relevant; generated by resolve.
pub trait_map: ItemLocalMap<Box<[TraitCandidate]>>,
}
impl<'tcx> OwnerInfo<'tcx> {
#[inline]
pub fn node(&self) -> OwnerNode<'tcx> {
self.nodes.node()
}
}
#[derive(Copy, Clone, Debug, HashStable_Generic)]
pub enum MaybeOwner<T> {
Owner(T),
NonOwner(HirId),
/// Used as a placeholder for unused LocalDefId.
Phantom,
}
impl<T> MaybeOwner<T> {
pub fn as_owner(self) -> Option<T> {
match self {
MaybeOwner::Owner(i) => Some(i),
MaybeOwner::NonOwner(_) | MaybeOwner::Phantom => None,
}
}
pub fn map<U>(self, f: impl FnOnce(T) -> U) -> MaybeOwner<U> {
match self {
MaybeOwner::Owner(i) => MaybeOwner::Owner(f(i)),
MaybeOwner::NonOwner(hir_id) => MaybeOwner::NonOwner(hir_id),
MaybeOwner::Phantom => MaybeOwner::Phantom,
}
}
pub fn unwrap(self) -> T {
match self {
MaybeOwner::Owner(i) => i,
MaybeOwner::NonOwner(_) | MaybeOwner::Phantom => panic!("Not a HIR owner"),
}
}
}
/// The top-level data structure that stores the entire contents of
/// the crate currently being compiled.
///
/// For more details, see the [rustc dev guide].
///
/// [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/hir.html
#[derive(Debug)]
pub struct Crate<'hir> {
pub owners: IndexVec<LocalDefId, MaybeOwner<&'hir OwnerInfo<'hir>>>,
// Only present when incr. comp. is enabled.
pub opt_hir_hash: Option<Fingerprint>,
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Closure<'hir> {
pub def_id: LocalDefId,
pub binder: ClosureBinder,
pub constness: Constness,
pub capture_clause: CaptureBy,
pub bound_generic_params: &'hir [GenericParam<'hir>],
pub fn_decl: &'hir FnDecl<'hir>,
pub body: BodyId,
/// The span of the declaration block: 'move |...| -> ...'
pub fn_decl_span: Span,
/// The span of the argument block `|...|`
pub fn_arg_span: Option<Span>,
pub movability: Option<Movability>,
}
/// A block of statements `{ .. }`, which may have a label (in this case the
/// `targeted_by_break` field will be `true`) and may be `unsafe` by means of
/// the `rules` being anything but `DefaultBlock`.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Block<'hir> {
/// Statements in a block.
pub stmts: &'hir [Stmt<'hir>],
/// An expression at the end of the block
/// without a semicolon, if any.
pub expr: Option<&'hir Expr<'hir>>,
#[stable_hasher(ignore)]
pub hir_id: HirId,
/// Distinguishes between `unsafe { ... }` and `{ ... }`.
pub rules: BlockCheckMode,
pub span: Span,
/// If true, then there may exist `break 'a` values that aim to
/// break out of this block early.
/// Used by `'label: {}` blocks and by `try {}` blocks.
pub targeted_by_break: bool,
}
impl<'hir> Block<'hir> {
pub fn innermost_block(&self) -> &Block<'hir> {
let mut block = self;
while let Some(Expr { kind: ExprKind::Block(inner_block, _), .. }) = block.expr {
block = inner_block;
}
block
}
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Pat<'hir> {
#[stable_hasher(ignore)]
pub hir_id: HirId,
pub kind: PatKind<'hir>,
pub span: Span,
/// Whether to use default binding modes.
/// At present, this is false only for destructuring assignment.
pub default_binding_modes: bool,
}
impl<'hir> Pat<'hir> {
fn walk_short_(&self, it: &mut impl FnMut(&Pat<'hir>) -> bool) -> bool {
if !it(self) {
return false;
}
use PatKind::*;
match self.kind {
Wild | Never | Lit(_) | Range(..) | Binding(.., None) | Path(_) => true,
Box(s) | Ref(s, _) | Binding(.., Some(s)) => s.walk_short_(it),
Struct(_, fields, _) => fields.iter().all(|field| field.pat.walk_short_(it)),
TupleStruct(_, s, _) | Tuple(s, _) | Or(s) => s.iter().all(|p| p.walk_short_(it)),
Slice(before, slice, after) => {
before.iter().chain(slice).chain(after.iter()).all(|p| p.walk_short_(it))
}
}
}
/// Walk the pattern in left-to-right order,
/// short circuiting (with `.all(..)`) if `false` is returned.
///
/// Note that when visiting e.g. `Tuple(ps)`,
/// if visiting `ps[0]` returns `false`,
/// then `ps[1]` will not be visited.
pub fn walk_short(&self, mut it: impl FnMut(&Pat<'hir>) -> bool) -> bool {
self.walk_short_(&mut it)
}
fn walk_(&self, it: &mut impl FnMut(&Pat<'hir>) -> bool) {
if !it(self) {
return;
}
use PatKind::*;
match self.kind {
Wild | Never | Lit(_) | Range(..) | Binding(.., None) | Path(_) => {}
Box(s) | Ref(s, _) | Binding(.., Some(s)) => s.walk_(it),
Struct(_, fields, _) => fields.iter().for_each(|field| field.pat.walk_(it)),
TupleStruct(_, s, _) | Tuple(s, _) | Or(s) => s.iter().for_each(|p| p.walk_(it)),
Slice(before, slice, after) => {
before.iter().chain(slice).chain(after.iter()).for_each(|p| p.walk_(it))
}
}
}
/// Walk the pattern in left-to-right order.
///
/// If `it(pat)` returns `false`, the children are not visited.
pub fn walk(&self, mut it: impl FnMut(&Pat<'hir>) -> bool) {
self.walk_(&mut it)
}
/// Walk the pattern in left-to-right order.
///
/// If you always want to recurse, prefer this method over `walk`.
pub fn walk_always(&self, mut it: impl FnMut(&Pat<'_>)) {
self.walk(|p| {
it(p);
true
})
}
/// Whether this a never pattern.
pub fn is_never_pattern(&self) -> bool {
let mut is_never_pattern = false;
self.walk(|pat| match &pat.kind {
PatKind::Never => {
is_never_pattern = true;
false
}
PatKind::Or(s) => {
is_never_pattern = s.iter().all(|p| p.is_never_pattern());
false
}
_ => true,
});
is_never_pattern
}
}
/// 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(Debug, Clone, Copy, HashStable_Generic)]
pub struct PatField<'hir> {
#[stable_hasher(ignore)]
pub hir_id: HirId,
/// The identifier for the field.
pub ident: Ident,
/// The pattern the field is destructured to.
pub pat: &'hir Pat<'hir>,
pub is_shorthand: bool,
pub span: Span,
}
#[derive(Copy, Clone, PartialEq, Debug, HashStable_Generic)]
pub enum RangeEnd {
Included,
Excluded,
}
impl fmt::Display for RangeEnd {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_str(match self {
RangeEnd::Included => "..=",
RangeEnd::Excluded => "..",
})
}
}
// Equivalent to `Option<usize>`. That type takes up 16 bytes on 64-bit, but
// this type only takes up 4 bytes, at the cost of being restricted to a
// maximum value of `u32::MAX - 1`. In practice, this is more than enough.
#[derive(Clone, Copy, PartialEq, Eq, Hash, HashStable_Generic)]
pub struct DotDotPos(u32);
impl DotDotPos {
/// Panics if n >= u32::MAX.
pub fn new(n: Option<usize>) -> Self {
match n {
Some(n) => {
assert!(n < u32::MAX as usize);
Self(n as u32)
}
None => Self(u32::MAX),
}
}
pub fn as_opt_usize(&self) -> Option<usize> {
if self.0 == u32::MAX { None } else { Some(self.0 as usize) }
}
}
impl fmt::Debug for DotDotPos {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
self.as_opt_usize().fmt(f)
}
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum PatKind<'hir> {
/// Represents a wildcard pattern (i.e., `_`).
Wild,
/// A fresh binding `ref mut binding @ OPT_SUBPATTERN`.
/// The `HirId` is the canonical ID for the variable being bound,
/// (e.g., in `Ok(x) | Err(x)`, both `x` use the same canonical ID),
/// which is the pattern ID of the first `x`.
Binding(BindingAnnotation, HirId, Ident, Option<&'hir Pat<'hir>>),
/// A struct or struct variant pattern (e.g., `Variant {x, y, ..}`).
/// The `bool` is `true` in the presence of a `..`.
Struct(QPath<'hir>, &'hir [PatField<'hir>], bool),
/// A tuple struct/variant pattern `Variant(x, y, .., z)`.
/// If the `..` pattern fragment is present, then `DotDotPos` denotes its position.
/// `0 <= position <= subpats.len()`
TupleStruct(QPath<'hir>, &'hir [Pat<'hir>], DotDotPos),
/// An or-pattern `A | B | C`.
/// Invariant: `pats.len() >= 2`.
Or(&'hir [Pat<'hir>]),
/// A never pattern `!`.
Never,
/// A path pattern for a unit struct/variant or a (maybe-associated) constant.
Path(QPath<'hir>),
/// A tuple pattern (e.g., `(a, b)`).
/// If the `..` pattern fragment is present, then `Option<usize>` denotes its position.
/// `0 <= position <= subpats.len()`
Tuple(&'hir [Pat<'hir>], DotDotPos),
/// A `box` pattern.
Box(&'hir Pat<'hir>),
/// A reference pattern (e.g., `&mut (a, b)`).
Ref(&'hir Pat<'hir>, Mutability),
/// A literal.
Lit(&'hir Expr<'hir>),
/// A range pattern (e.g., `1..=2` or `1..2`).
Range(Option<&'hir Expr<'hir>>, Option<&'hir Expr<'hir>>, RangeEnd),
/// A slice pattern, `[before_0, ..., before_n, (slice, after_0, ..., after_n)?]`.
///
/// Here, `slice` is lowered from the syntax `($binding_mode $ident @)? ..`.
/// If `slice` exists, then `after` can be non-empty.
///
/// The representation for e.g., `[a, b, .., c, d]` is:
/// ```ignore (illustrative)
/// PatKind::Slice([Binding(a), Binding(b)], Some(Wild), [Binding(c), Binding(d)])
/// ```
Slice(&'hir [Pat<'hir>], Option<&'hir Pat<'hir>>, &'hir [Pat<'hir>]),
}
/// A statement.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Stmt<'hir> {
pub hir_id: HirId,
pub kind: StmtKind<'hir>,
pub span: Span,
}
/// The contents of a statement.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum StmtKind<'hir> {
/// A local (`let`) binding.
Local(&'hir Local<'hir>),
/// An item binding.
Item(ItemId),
/// An expression without a trailing semi-colon (must have unit type).
Expr(&'hir Expr<'hir>),
/// An expression with a trailing semi-colon (may have any type).
Semi(&'hir Expr<'hir>),
}
/// Represents a `let` statement (i.e., `let <pat>:<ty> = <init>;`).
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Local<'hir> {
pub pat: &'hir Pat<'hir>,
/// Type annotation, if any (otherwise the type will be inferred).
pub ty: Option<&'hir Ty<'hir>>,
/// Initializer expression to set the value, if any.
pub init: Option<&'hir Expr<'hir>>,
/// Else block for a `let...else` binding.
pub els: Option<&'hir Block<'hir>>,
pub hir_id: HirId,
pub span: Span,
/// Can be `ForLoopDesugar` if the `let` statement is part of a `for` loop
/// desugaring. Otherwise will be `Normal`.
pub source: LocalSource,
}
/// Represents a single arm of a `match` expression, e.g.
/// `<pat> (if <guard>) => <body>`.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Arm<'hir> {
#[stable_hasher(ignore)]
pub hir_id: HirId,
pub span: Span,
/// If this pattern and the optional guard matches, then `body` is evaluated.
pub pat: &'hir Pat<'hir>,
/// Optional guard clause.
pub guard: Option<Guard<'hir>>,
/// The expression the arm evaluates to if this arm matches.
pub body: &'hir Expr<'hir>,
}
/// Represents a `let <pat>[: <ty>] = <expr>` expression (not a Local), occurring in an `if-let` or
/// `let-else`, evaluating to a boolean. Typically the pattern is refutable.
///
/// In an if-let, imagine it as `if (let <pat> = <expr>) { ... }`; in a let-else, it is part of the
/// desugaring to if-let. Only let-else supports the type annotation at present.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Let<'hir> {
pub hir_id: HirId,
pub span: Span,
pub pat: &'hir Pat<'hir>,
pub ty: Option<&'hir Ty<'hir>>,
pub init: &'hir Expr<'hir>,
/// `Some` when this let expressions is not in a syntanctically valid location.
/// Used to prevent building MIR in such situations.
pub is_recovered: Option<ErrorGuaranteed>,
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum Guard<'hir> {
If(&'hir Expr<'hir>),
IfLet(&'hir Let<'hir>),
}
impl<'hir> Guard<'hir> {
/// Returns the body of the guard
///
/// In other words, returns the e in either of the following:
///
/// - `if e`
/// - `if let x = e`
pub fn body(&self) -> &'hir Expr<'hir> {
match self {
Guard::If(e) | Guard::IfLet(Let { init: e, .. }) => e,
}
}
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct ExprField<'hir> {
#[stable_hasher(ignore)]
pub hir_id: HirId,
pub ident: Ident,
pub expr: &'hir Expr<'hir>,
pub span: Span,
pub is_shorthand: bool,
}
#[derive(Copy, Clone, PartialEq, Debug, HashStable_Generic)]
pub enum BlockCheckMode {
DefaultBlock,
UnsafeBlock(UnsafeSource),
}
#[derive(Copy, Clone, PartialEq, Debug, HashStable_Generic)]
pub enum UnsafeSource {
CompilerGenerated,
UserProvided,
}
#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
pub struct BodyId {
pub hir_id: HirId,
}
/// The body of a function, closure, or constant value. In the case of
/// a function, the body contains not only the function body itself
/// (which is an expression), but also the argument patterns, since
/// those are something that the caller doesn't really care about.
///
/// # Examples
///
/// ```
/// fn foo((x, y): (u32, u32)) -> u32 {
/// x + y
/// }
/// ```
///
/// Here, the `Body` associated with `foo()` would contain:
///
/// - an `params` array containing the `(x, y)` pattern
/// - a `value` containing the `x + y` expression (maybe wrapped in a block)
/// - `coroutine_kind` would be `None`
///
/// All bodies have an **owner**, which can be accessed via the HIR
/// map using `body_owner_def_id()`.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Body<'hir> {
pub params: &'hir [Param<'hir>],
pub value: &'hir Expr<'hir>,
pub coroutine_kind: Option<CoroutineKind>,
}
impl<'hir> Body<'hir> {
pub fn id(&self) -> BodyId {
BodyId { hir_id: self.value.hir_id }
}
pub fn coroutine_kind(&self) -> Option<CoroutineKind> {
self.coroutine_kind
}
}
/// The type of source expression that caused this coroutine to be created.
#[derive(Clone, PartialEq, Eq, Debug, Copy, Hash, HashStable_Generic, Encodable, Decodable)]
pub enum CoroutineKind {
/// An explicit `async` block or the body of an `async` function.
Async(CoroutineSource),
/// An explicit `gen` block or the body of a `gen` function.
Gen(CoroutineSource),
/// An explicit `async gen` block or the body of an `async gen` function,
/// which is able to both `yield` and `.await`.
AsyncGen(CoroutineSource),
/// A coroutine literal created via a `yield` inside a closure.
Coroutine,
}
impl fmt::Display for CoroutineKind {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
CoroutineKind::Async(k) => {
if f.alternate() {
f.write_str("`async` ")?;
} else {
f.write_str("async ")?
}
k.fmt(f)
}
CoroutineKind::Coroutine => f.write_str("coroutine"),
CoroutineKind::Gen(k) => {
if f.alternate() {
f.write_str("`gen` ")?;
} else {
f.write_str("gen ")?
}
k.fmt(f)
}
CoroutineKind::AsyncGen(k) => {
if f.alternate() {
f.write_str("`async gen` ")?;
} else {
f.write_str("async gen ")?
}
k.fmt(f)
}
}
}
}
/// In the case of a coroutine created as part of an async/gen construct,
/// which kind of async/gen construct caused it to be created?
///
/// This helps error messages but is also used to drive coercions in
/// type-checking (see #60424).
#[derive(Clone, PartialEq, Eq, Hash, Debug, Copy, HashStable_Generic, Encodable, Decodable)]
pub enum CoroutineSource {
/// An explicit `async`/`gen` block written by the user.
Block,
/// An explicit `async`/`gen` closure written by the user.
Closure,
/// The `async`/`gen` block generated as the body of an async/gen function.
Fn,
}
impl fmt::Display for CoroutineSource {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
CoroutineSource::Block => "block",
CoroutineSource::Closure => "closure body",
CoroutineSource::Fn => "fn body",
}
.fmt(f)
}
}
#[derive(Copy, Clone, Debug)]
pub enum BodyOwnerKind {
/// Functions and methods.
Fn,
/// Closures
Closure,
/// Constants and associated constants, also including inline constants.
Const { inline: bool },
/// Initializer of a `static` item.
Static(Mutability),
}
impl BodyOwnerKind {
pub fn is_fn_or_closure(self) -> bool {
match self {
BodyOwnerKind::Fn | BodyOwnerKind::Closure => true,
BodyOwnerKind::Const { .. } | BodyOwnerKind::Static(_) => false,
}
}
}
/// The kind of an item that requires const-checking.
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum ConstContext {
/// A `const fn`.
ConstFn,
/// A `static` or `static mut`.
Static(Mutability),
/// A `const`, associated `const`, or other const context.
///
/// Other contexts include:
/// - Array length expressions
/// - Enum discriminants
/// - Const generics
///
/// For the most part, other contexts are treated just like a regular `const`, so they are
/// lumped into the same category.
Const { inline: bool },
}
impl ConstContext {
/// A description of this const context that can appear between backticks in an error message.
///
/// E.g. `const` or `static mut`.
pub fn keyword_name(self) -> &'static str {
match self {
Self::Const { .. } => "const",
Self::Static(Mutability::Not) => "static",
Self::Static(Mutability::Mut) => "static mut",
Self::ConstFn => "const fn",
}
}
}
/// A colloquial, trivially pluralizable description of this const context for use in error
/// messages.
impl fmt::Display for ConstContext {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match *self {
Self::Const { .. } => write!(f, "constant"),
Self::Static(_) => write!(f, "static"),
Self::ConstFn => write!(f, "constant function"),
}
}
}
// NOTE: `IntoDiagnosticArg` impl for `ConstContext` lives in `rustc_errors`
// due to a cyclical dependency between hir that crate.
/// A literal.
pub type Lit = Spanned<LitKind>;
#[derive(Copy, Clone, Debug, HashStable_Generic)]
pub enum ArrayLen {
Infer(HirId, Span),
Body(AnonConst),
}
impl ArrayLen {
pub fn hir_id(&self) -> HirId {
match self {
&ArrayLen::Infer(hir_id, _) | &ArrayLen::Body(AnonConst { hir_id, .. }) => hir_id,
}
}
}
/// 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.
///
/// You can check if this anon const is a default in a const param
/// `const N: usize = { ... }` with `tcx.hir().opt_const_param_default_param_def_id(..)`
#[derive(Copy, Clone, Debug, HashStable_Generic)]
pub struct AnonConst {
pub hir_id: HirId,
pub def_id: LocalDefId,
pub body: BodyId,
}
/// An inline constant expression `const { something }`.
#[derive(Copy, Clone, Debug, HashStable_Generic)]
pub struct ConstBlock {
pub hir_id: HirId,
pub def_id: LocalDefId,
pub body: BodyId,
}
/// An expression.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Expr<'hir> {
pub hir_id: HirId,
pub kind: ExprKind<'hir>,
pub span: Span,
}
impl Expr<'_> {
pub fn precedence(&self) -> ExprPrecedence {
match self.kind {
ExprKind::ConstBlock(_) => ExprPrecedence::ConstBlock,
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::DropTemps(ref expr, ..) => expr.precedence(),
ExprKind::If(..) => ExprPrecedence::If,
ExprKind::Let(..) => ExprPrecedence::Let,
ExprKind::Loop(..) => ExprPrecedence::Loop,
ExprKind::Match(..) => ExprPrecedence::Match,
ExprKind::Closure { .. } => ExprPrecedence::Closure,
ExprKind::Block(..) => ExprPrecedence::Block,
ExprKind::Assign(..) => ExprPrecedence::Assign,
ExprKind::AssignOp(..) => ExprPrecedence::AssignOp,
ExprKind::Field(..) => ExprPrecedence::Field,
ExprKind::Index(..) => ExprPrecedence::Index,
ExprKind::Path(..) => ExprPrecedence::Path,
ExprKind::AddrOf(..) => ExprPrecedence::AddrOf,
ExprKind::Break(..) => ExprPrecedence::Break,
ExprKind::Continue(..) => ExprPrecedence::Continue,
ExprKind::Ret(..) => ExprPrecedence::Ret,
ExprKind::Become(..) => ExprPrecedence::Become,
ExprKind::InlineAsm(..) => ExprPrecedence::InlineAsm,
ExprKind::OffsetOf(..) => ExprPrecedence::OffsetOf,
ExprKind::Struct(..) => ExprPrecedence::Struct,
ExprKind::Repeat(..) => ExprPrecedence::Repeat,
ExprKind::Yield(..) => ExprPrecedence::Yield,
ExprKind::Err(_) => ExprPrecedence::Err,
}
}
/// Whether this looks like a place expr, without checking for deref
/// adjustments.
/// This will return `true` in some potentially surprising cases such as
/// `CONSTANT.field`.
pub fn is_syntactic_place_expr(&self) -> bool {
self.is_place_expr(|_| true)
}
/// Whether this is a place expression.
///
/// `allow_projections_from` should return `true` if indexing a field or index expression based
/// on the given expression should be considered a place expression.
pub fn is_place_expr(&self, mut allow_projections_from: impl FnMut(&Self) -> bool) -> bool {
match self.kind {
ExprKind::Path(QPath::Resolved(_, ref path)) => {
matches!(path.res, Res::Local(..) | Res::Def(DefKind::Static(_), _) | Res::Err)
}
// Type ascription inherits its place expression kind from its
// operand. See:
// https://github.com/rust-lang/rfcs/blob/master/text/0803-type-ascription.md#type-ascription-and-temporaries
ExprKind::Type(ref e, _) => e.is_place_expr(allow_projections_from),
ExprKind::Unary(UnOp::Deref, _) => true,
ExprKind::Field(ref base, _) | ExprKind::Index(ref base, _, _) => {
allow_projections_from(base) || base.is_place_expr(allow_projections_from)
}
// Lang item paths cannot currently be local variables or statics.
ExprKind::Path(QPath::LangItem(..)) => false,
// Partially qualified paths in expressions can only legally
// refer to associated items which are always rvalues.
ExprKind::Path(QPath::TypeRelative(..))
| ExprKind::Call(..)
| ExprKind::MethodCall(..)
| ExprKind::Struct(..)
| ExprKind::Tup(..)
| ExprKind::If(..)
| ExprKind::Match(..)
| ExprKind::Closure { .. }
| ExprKind::Block(..)
| ExprKind::Repeat(..)
| ExprKind::Array(..)
| ExprKind::Break(..)
| ExprKind::Continue(..)
| ExprKind::Ret(..)
| ExprKind::Become(..)
| ExprKind::Let(..)
| ExprKind::Loop(..)
| ExprKind::Assign(..)
| ExprKind::InlineAsm(..)
| ExprKind::OffsetOf(..)
| ExprKind::AssignOp(..)
| ExprKind::Lit(_)
| ExprKind::ConstBlock(..)
| ExprKind::Unary(..)
| ExprKind::AddrOf(..)
| ExprKind::Binary(..)
| ExprKind::Yield(..)
| ExprKind::Cast(..)
| ExprKind::DropTemps(..)
| ExprKind::Err(_) => false,
}
}
/// If `Self.kind` is `ExprKind::DropTemps(expr)`, drill down until we get a non-`DropTemps`
/// `Expr`. This is used in suggestions to ignore this `ExprKind` as it is semantically
/// silent, only signaling the ownership system. By doing this, suggestions that check the
/// `ExprKind` of any given `Expr` for presentation don't have to care about `DropTemps`
/// beyond remembering to call this function before doing analysis on it.
pub fn peel_drop_temps(&self) -> &Self {
let mut expr = self;
while let ExprKind::DropTemps(inner) = &expr.kind {
expr = inner;
}
expr
}
pub fn peel_blocks(&self) -> &Self {
let mut expr = self;
while let ExprKind::Block(Block { expr: Some(inner), .. }, _) = &expr.kind {
expr = inner;
}
expr
}
pub fn peel_borrows(&self) -> &Self {
let mut expr = self;
while let ExprKind::AddrOf(.., inner) = &expr.kind {
expr = inner;
}
expr
}
pub fn can_have_side_effects(&self) -> bool {
match self.peel_drop_temps().kind {
ExprKind::Path(_) | ExprKind::Lit(_) | ExprKind::OffsetOf(..) => false,
ExprKind::Type(base, _)
| ExprKind::Unary(_, base)
| ExprKind::Field(base, _)
| ExprKind::Index(base, _, _)
| ExprKind::AddrOf(.., base)
| ExprKind::Cast(base, _) => {
// This isn't exactly true for `Index` and all `Unary`, but we are using this
// method exclusively for diagnostics and there's a *cultural* pressure against
// them being used only for its side-effects.
base.can_have_side_effects()
}
ExprKind::Struct(_, fields, init) => {
fields.iter().map(|field| field.expr).chain(init).any(|e| e.can_have_side_effects())
}
ExprKind::Array(args)
| ExprKind::Tup(args)
| ExprKind::Call(
Expr {
kind:
ExprKind::Path(QPath::Resolved(
None,
Path { res: Res::Def(DefKind::Ctor(_, CtorKind::Fn), _), .. },
)),
..
},
args,
) => args.iter().any(|arg| arg.can_have_side_effects()),
ExprKind::If(..)
| ExprKind::Match(..)
| ExprKind::MethodCall(..)
| ExprKind::Call(..)
| ExprKind::Closure { .. }
| ExprKind::Block(..)
| ExprKind::Repeat(..)
| ExprKind::Break(..)
| ExprKind::Continue(..)
| ExprKind::Ret(..)
| ExprKind::Become(..)
| ExprKind::Let(..)
| ExprKind::Loop(..)
| ExprKind::Assign(..)
| ExprKind::InlineAsm(..)
| ExprKind::AssignOp(..)
| ExprKind::ConstBlock(..)
| ExprKind::Binary(..)
| ExprKind::Yield(..)
| ExprKind::DropTemps(..)
| ExprKind::Err(_) => true,
}
}
/// To a first-order approximation, is this a pattern?
pub fn is_approximately_pattern(&self) -> bool {
match &self.kind {
ExprKind::Array(_)
| ExprKind::Call(..)
| ExprKind::Tup(_)
| ExprKind::Lit(_)
| ExprKind::Path(_)
| ExprKind::Struct(..) => true,
_ => false,
}
}
pub fn method_ident(&self) -> Option<Ident> {
match self.kind {
ExprKind::MethodCall(receiver_method, ..) => Some(receiver_method.ident),
ExprKind::Unary(_, expr) | ExprKind::AddrOf(.., expr) => expr.method_ident(),
_ => None,
}
}
}
/// Checks if the specified expression is a built-in range literal.
/// (See: `LoweringContext::lower_expr()`).
pub fn is_range_literal(expr: &Expr<'_>) -> bool {
match expr.kind {
// All built-in range literals but `..=` and `..` desugar to `Struct`s.
ExprKind::Struct(ref qpath, _, _) => matches!(
**qpath,
QPath::LangItem(
LangItem::Range
| LangItem::RangeTo
| LangItem::RangeFrom
| LangItem::RangeFull
| LangItem::RangeToInclusive,
..
)
),
// `..=` desugars into `::std::ops::RangeInclusive::new(...)`.
ExprKind::Call(ref func, _) => {
matches!(func.kind, ExprKind::Path(QPath::LangItem(LangItem::RangeInclusiveNew, ..)))
}
_ => false,
}
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum ExprKind<'hir> {
/// Allow anonymous constants from an inline `const` block
ConstBlock(ConstBlock),
/// An array (e.g., `[a, b, c, d]`).
Array(&'hir [Expr<'hir>]),
/// A function call.
///
/// The first field resolves to the function itself (usually an `ExprKind::Path`),
/// 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(&'hir Expr<'hir>, &'hir [Expr<'hir>]),
/// A method call (e.g., `x.foo::<'static, Bar, Baz>(a, b, c, d)`).
///
/// The `PathSegment` represents the method name and its generic arguments
/// (within the angle brackets).
/// The `&Expr` is the expression that evaluates
/// to the object on which the method is being called on (the receiver),
/// and the `&[Expr]` is 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], span)`.
/// The final `Span` represents the span of the function and arguments
/// (e.g. `foo::<Bar, Baz>(a, b, c, d)` in `x.foo::<Bar, Baz>(a, b, c, d)`
///
/// To resolve the called method to a `DefId`, call [`type_dependent_def_id`] with
/// the `hir_id` of the `MethodCall` node itself.
///
/// [`type_dependent_def_id`]: ../../rustc_middle/ty/struct.TypeckResults.html#method.type_dependent_def_id
MethodCall(&'hir PathSegment<'hir>, &'hir Expr<'hir>, &'hir [Expr<'hir>], Span),
/// A tuple (e.g., `(a, b, c, d)`).
Tup(&'hir [Expr<'hir>]),
/// A binary operation (e.g., `a + b`, `a * b`).
Binary(BinOp, &'hir Expr<'hir>, &'hir Expr<'hir>),
/// A unary operation (e.g., `!x`, `*x`).
Unary(UnOp, &'hir Expr<'hir>),
/// A literal (e.g., `1`, `"foo"`).
Lit(&'hir Lit),
/// A cast (e.g., `foo as f64`).
Cast(&'hir Expr<'hir>, &'hir Ty<'hir>),
/// A type ascription (e.g., `x: Foo`). See RFC 3307.
Type(&'hir Expr<'hir>, &'hir Ty<'hir>),
/// Wraps the expression in a terminating scope.
/// This makes it semantically equivalent to `{ let _t = expr; _t }`.
///
/// This construct only exists to tweak the drop order in HIR lowering.
/// An example of that is the desugaring of `for` loops.
DropTemps(&'hir Expr<'hir>),
/// A `let $pat = $expr` expression.
///
/// These are not `Local` and only occur as expressions.
/// The `let Some(x) = foo()` in `if let Some(x) = foo()` is an example of `Let(..)`.
Let(&'hir Let<'hir>),
/// An `if` block, with an optional else block.
///
/// I.e., `if <expr> { <expr> } else { <expr> }`.
If(&'hir Expr<'hir>, &'hir Expr<'hir>, Option<&'hir Expr<'hir>>),
/// A conditionless loop (can be exited with `break`, `continue`, or `return`).
///
/// I.e., `'label: loop { <block> }`.
///
/// The `Span` is the loop header (`for x in y`/`while let pat = expr`).
Loop(&'hir Block<'hir>, Option<Label>, LoopSource, Span),
/// A `match` block, with a source that indicates whether or not it is
/// the result of a desugaring, and if so, which kind.
Match(&'hir Expr<'hir>, &'hir [Arm<'hir>], MatchSource),
/// A closure (e.g., `move |a, b, c| {a + b + c}`).
///
/// The `Span` is the argument block `|...|`.
///
/// This may also be a coroutine literal or an `async block` as indicated by the
/// `Option<Movability>`.
Closure(&'hir Closure<'hir>),
/// A block (e.g., `'label: { ... }`).
Block(&'hir Block<'hir>, Option<Label>),
/// An assignment (e.g., `a = foo()`).
Assign(&'hir Expr<'hir>, &'hir Expr<'hir>, Span),
/// An assignment with an operator.
///
/// E.g., `a += 1`.
AssignOp(BinOp, &'hir Expr<'hir>, &'hir Expr<'hir>),
/// Access of a named (e.g., `obj.foo`) or unnamed (e.g., `obj.0`) struct or tuple field.
Field(&'hir Expr<'hir>, Ident),
/// An indexing operation (`foo[2]`).
/// Similar to [`ExprKind::MethodCall`], the final `Span` represents the span of the brackets
/// and index.
Index(&'hir Expr<'hir>, &'hir Expr<'hir>, Span),
/// Path to a definition, possibly containing lifetime or type parameters.
Path(QPath<'hir>),
/// A referencing operation (i.e., `&a` or `&mut a`).
AddrOf(BorrowKind, Mutability, &'hir Expr<'hir>),
/// A `break`, with an optional label to break.
Break(Destination, Option<&'hir Expr<'hir>>),
/// A `continue`, with an optional label.
Continue(Destination),
/// A `return`, with an optional value to be returned.
Ret(Option<&'hir Expr<'hir>>),
/// A `become`, with the value to be returned.
Become(&'hir Expr<'hir>),
/// Inline assembly (from `asm!`), with its outputs and inputs.
InlineAsm(&'hir InlineAsm<'hir>),
/// Field offset (`offset_of!`)
OffsetOf(&'hir Ty<'hir>, &'hir [Ident]),
/// A struct or struct-like variant literal expression.
///
/// E.g., `Foo {x: 1, y: 2}`, or `Foo {x: 1, .. base}`,
/// where `base` is the `Option<Expr>`.
Struct(&'hir QPath<'hir>, &'hir [ExprField<'hir>], Option<&'hir Expr<'hir>>),
/// An array literal constructed from one repeated element.
///
/// E.g., `[1; 5]`. The first expression is the element
/// to be repeated; the second is the number of times to repeat it.
Repeat(&'hir Expr<'hir>, ArrayLen),
/// A suspension point for coroutines (i.e., `yield <expr>`).
Yield(&'hir Expr<'hir>, YieldSource),
/// A placeholder for an expression that wasn't syntactically well formed in some way.
Err(rustc_span::ErrorGuaranteed),
}
/// Represents an optionally `Self`-qualified value/type path or associated extension.
///
/// To resolve the path to a `DefId`, call [`qpath_res`].
///
/// [`qpath_res`]: ../../rustc_middle/ty/struct.TypeckResults.html#method.qpath_res
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum QPath<'hir> {
/// Path to a definition, optionally "fully-qualified" with a `Self`
/// type, if the path points to an associated item in a trait.
///
/// E.g., an unqualified path like `Clone::clone` has `None` for `Self`,
/// while `<Vec<T> as Clone>::clone` has `Some(Vec<T>)` for `Self`,
/// even though they both have the same two-segment `Clone::clone` `Path`.
Resolved(Option<&'hir Ty<'hir>>, &'hir Path<'hir>),
/// Type-related paths (e.g., `<T>::default` or `<T>::Output`).
/// Will be resolved by type-checking to an associated item.
///
/// UFCS source paths can desugar into this, with `Vec::new` turning into
/// `<Vec>::new`, and `T::X::Y::method` into `<<<T>::X>::Y>::method`,
/// the `X` and `Y` nodes each being a `TyKind::Path(QPath::TypeRelative(..))`.
TypeRelative(&'hir Ty<'hir>, &'hir PathSegment<'hir>),
/// Reference to a `#[lang = "foo"]` item.
LangItem(LangItem, Span),
}
impl<'hir> QPath<'hir> {
/// Returns the span of this `QPath`.
pub fn span(&self) -> Span {
match *self {
QPath::Resolved(_, path) => path.span,
QPath::TypeRelative(qself, ps) => qself.span.to(ps.ident.span),
QPath::LangItem(_, span) => span,
}
}
/// Returns the span of the qself of this `QPath`. For example, `()` in
/// `<() as Trait>::method`.
pub fn qself_span(&self) -> Span {
match *self {
QPath::Resolved(_, path) => path.span,
QPath::TypeRelative(qself, _) => qself.span,
QPath::LangItem(_, span) => span,
}
}
}
/// Hints at the original code for a let statement.
#[derive(Copy, Clone, Debug, HashStable_Generic)]
pub enum LocalSource {
/// A `match _ { .. }`.
Normal,
/// When lowering async functions, we create locals within the `async move` so that
/// all parameters are dropped after the future is polled.
///
/// ```ignore (pseudo-Rust)
/// async fn foo(<pattern> @ x: Type) {
/// async move {
/// let <pattern> = x;
/// }
/// }
/// ```
AsyncFn,
/// A desugared `<expr>.await`.
AwaitDesugar,
/// A desugared `expr = expr`, where the LHS is a tuple, struct or array.
/// The span is that of the `=` sign.
AssignDesugar(Span),
}
/// Hints at the original code for a `match _ { .. }`.
#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, HashStable_Generic, Encodable, Decodable)]
pub enum MatchSource {
/// A `match _ { .. }`.
Normal,
/// A desugared `for _ in _ { .. }` loop.
ForLoopDesugar,
/// A desugared `?` operator.
TryDesugar(HirId),
/// A desugared `<expr>.await`.
AwaitDesugar,
/// A desugared `format_args!()`.
FormatArgs,
}
impl MatchSource {
#[inline]
pub const fn name(self) -> &'static str {
use MatchSource::*;
match self {
Normal => "match",
ForLoopDesugar => "for",
TryDesugar(_) => "?",
AwaitDesugar => ".await",
FormatArgs => "format_args!()",
}
}
}
/// The loop type that yielded an `ExprKind::Loop`.
#[derive(Copy, Clone, PartialEq, Debug, HashStable_Generic)]
pub enum LoopSource {
/// A `loop { .. }` loop.
Loop,
/// A `while _ { .. }` loop.
While,
/// A `for _ in _ { .. }` loop.
ForLoop,
}
impl LoopSource {
pub fn name(self) -> &'static str {
match self {
LoopSource::Loop => "loop",
LoopSource::While => "while",
LoopSource::ForLoop => "for",
}
}
}
#[derive(Copy, Clone, Debug, HashStable_Generic)]
pub enum LoopIdError {
OutsideLoopScope,
UnlabeledCfInWhileCondition,
UnresolvedLabel,
}
impl fmt::Display for LoopIdError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_str(match self {
LoopIdError::OutsideLoopScope => "not inside loop scope",
LoopIdError::UnlabeledCfInWhileCondition => {
"unlabeled control flow (break or continue) in while condition"
}
LoopIdError::UnresolvedLabel => "label not found",
})
}
}
#[derive(Copy, Clone, Debug, HashStable_Generic)]
pub struct Destination {
/// This is `Some(_)` iff there is an explicit user-specified 'label
pub label: Option<Label>,
/// These errors are caught and then reported during the diagnostics pass in
/// `librustc_passes/loops.rs`
pub target_id: Result<HirId, LoopIdError>,
}
/// The yield kind that caused an `ExprKind::Yield`.
#[derive(Copy, Clone, Debug, HashStable_Generic)]
pub enum YieldSource {
/// An `<expr>.await`.
Await { expr: Option<HirId> },
/// A plain `yield`.
Yield,
}
impl YieldSource {
pub fn is_await(&self) -> bool {
matches!(self, YieldSource::Await { .. })
}
}
impl fmt::Display for YieldSource {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_str(match self {
YieldSource::Await { .. } => "`await`",
YieldSource::Yield => "`yield`",
})
}
}
// N.B., if you change this, you'll probably want to change the corresponding
// type structure in middle/ty.rs as well.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct MutTy<'hir> {
pub ty: &'hir Ty<'hir>,
pub mutbl: Mutability,
}
/// Represents a function's signature in a trait declaration,
/// trait implementation, or a free function.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct FnSig<'hir> {
pub header: FnHeader,
pub decl: &'hir FnDecl<'hir>,
pub span: Span,
}
// The bodies for items are stored "out of line", in a separate
// hashmap in the `Crate`. Here we just record the hir-id of the item
// so it can fetched later.
#[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
pub struct TraitItemId {
pub owner_id: OwnerId,
}
impl TraitItemId {
#[inline]
pub fn hir_id(&self) -> HirId {
// Items are always HIR owners.
HirId::make_owner(self.owner_id.def_id)
}
}
/// 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(Debug, Clone, Copy, HashStable_Generic)]
pub struct TraitItem<'hir> {
pub ident: Ident,
pub owner_id: OwnerId,
pub generics: &'hir Generics<'hir>,
pub kind: TraitItemKind<'hir>,
pub span: Span,
pub defaultness: Defaultness,
}
macro_rules! expect_methods_self_kind {
( $( $name:ident, $ret_ty:ty, $pat:pat, $ret_val:expr; )* ) => {
$(
#[track_caller]
pub fn $name(&self) -> $ret_ty {
let $pat = &self.kind else { expect_failed(stringify!($ident), self) };
$ret_val
}
)*
}
}
macro_rules! expect_methods_self {
( $( $name:ident, $ret_ty:ty, $pat:pat, $ret_val:expr; )* ) => {
$(
#[track_caller]
pub fn $name(&self) -> $ret_ty {
let $pat = self else { expect_failed(stringify!($ident), self) };
$ret_val
}
)*
}
}
#[track_caller]
fn expect_failed<T: fmt::Debug>(ident: &'static str, found: T) -> ! {
panic!("{ident}: found {found:?}")
}
impl<'hir> TraitItem<'hir> {
#[inline]
pub fn hir_id(&self) -> HirId {
// Items are always HIR owners.
HirId::make_owner(self.owner_id.def_id)
}
pub fn trait_item_id(&self) -> TraitItemId {
TraitItemId { owner_id: self.owner_id }
}
expect_methods_self_kind! {
expect_const, (&'hir Ty<'hir>, Option<BodyId>),
TraitItemKind::Const(ty, body), (ty, *body);
expect_fn, (&FnSig<'hir>, &TraitFn<'hir>),
TraitItemKind::Fn(ty, trfn), (ty, trfn);
expect_type, (GenericBounds<'hir>, Option<&'hir Ty<'hir>>),
TraitItemKind::Type(bounds, ty), (bounds, *ty);
}
}
/// Represents a trait method's body (or just argument names).
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum TraitFn<'hir> {
/// No default body in the trait, just a signature.
Required(&'hir [Ident]),
/// Both signature and body are provided in the trait.
Provided(BodyId),
}
/// Represents a trait method or associated constant or type
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum TraitItemKind<'hir> {
/// An associated constant with an optional value (otherwise `impl`s must contain a value).
Const(&'hir Ty<'hir>, Option<BodyId>),
/// An associated function with an optional body.
Fn(FnSig<'hir>, TraitFn<'hir>),
/// An associated type with (possibly empty) bounds and optional concrete
/// type.
Type(GenericBounds<'hir>, Option<&'hir Ty<'hir>>),
}
// The bodies for items are stored "out of line", in a separate
// hashmap in the `Crate`. Here we just record the hir-id of the item
// so it can fetched later.
#[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
pub struct ImplItemId {
pub owner_id: OwnerId,
}
impl ImplItemId {
#[inline]
pub fn hir_id(&self) -> HirId {
// Items are always HIR owners.
HirId::make_owner(self.owner_id.def_id)
}
}
/// Represents anything within an `impl` block.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct ImplItem<'hir> {
pub ident: Ident,
pub owner_id: OwnerId,
pub generics: &'hir Generics<'hir>,
pub kind: ImplItemKind<'hir>,
pub defaultness: Defaultness,
pub span: Span,
pub vis_span: Span,
}
impl<'hir> ImplItem<'hir> {
#[inline]
pub fn hir_id(&self) -> HirId {
// Items are always HIR owners.
HirId::make_owner(self.owner_id.def_id)
}
pub fn impl_item_id(&self) -> ImplItemId {
ImplItemId { owner_id: self.owner_id }
}
expect_methods_self_kind! {
expect_const, (&'hir Ty<'hir>, BodyId), ImplItemKind::Const(ty, body), (ty, *body);
expect_fn, (&FnSig<'hir>, BodyId), ImplItemKind::Fn(ty, body), (ty, *body);
expect_type, &'hir Ty<'hir>, ImplItemKind::Type(ty), ty;
}
}
/// Represents various kinds of content within an `impl`.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum ImplItemKind<'hir> {
/// An associated constant of the given type, set to the constant result
/// of the expression.
Const(&'hir Ty<'hir>, BodyId),
/// An associated function implementation with the given signature and body.
Fn(FnSig<'hir>, BodyId),
/// An associated type.
Type(&'hir Ty<'hir>),
}
/// Bind a type to an associated type (i.e., `A = Foo`).
///
/// Bindings like `A: Debug` are represented as a special type `A =
/// $::Debug` that is understood by the astconv code.
///
/// FIXME(alexreg): why have a separate type for the binding case,
/// wouldn't it be better to make the `ty` field an enum like the
/// following?
///
/// ```ignore (pseudo-rust)
/// enum TypeBindingKind {
/// Equals(...),
/// Binding(...),
/// }
/// ```
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct TypeBinding<'hir> {
pub hir_id: HirId,
pub ident: Ident,
pub gen_args: &'hir GenericArgs<'hir>,
pub kind: TypeBindingKind<'hir>,
pub span: Span,
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum Term<'hir> {
Ty(&'hir Ty<'hir>),
Const(AnonConst),
}
impl<'hir> From<&'hir Ty<'hir>> for Term<'hir> {
fn from(ty: &'hir Ty<'hir>) -> Self {
Term::Ty(ty)
}
}
impl<'hir> From<AnonConst> for Term<'hir> {
fn from(c: AnonConst) -> Self {
Term::Const(c)
}
}
// Represents the two kinds of type bindings.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum TypeBindingKind<'hir> {
/// E.g., `Foo<Bar: Send>`.
Constraint { bounds: &'hir [GenericBound<'hir>] },
/// E.g., `Foo<Bar = ()>`, `Foo<Bar = ()>`
Equality { term: Term<'hir> },
}
impl TypeBinding<'_> {
pub fn ty(&self) -> &Ty<'_> {
match self.kind {
TypeBindingKind::Equality { term: Term::Ty(ref ty) } => ty,
_ => panic!("expected equality type binding for parenthesized generic args"),
}
}
pub fn opt_const(&self) -> Option<&'_ AnonConst> {
match self.kind {
TypeBindingKind::Equality { term: Term::Const(ref c) } => Some(c),
_ => None,
}
}
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Ty<'hir> {
pub hir_id: HirId,
pub kind: TyKind<'hir>,
pub span: Span,
}
impl<'hir> Ty<'hir> {
/// Returns `true` if `param_def_id` matches the `bounded_ty` of this predicate.
pub fn as_generic_param(&self) -> Option<(DefId, Ident)> {
let TyKind::Path(QPath::Resolved(None, path)) = self.kind else {
return None;
};
let [segment] = &path.segments else {
return None;
};
match path.res {
Res::Def(DefKind::TyParam, def_id) | Res::SelfTyParam { trait_: def_id } => {
Some((def_id, segment.ident))
}
_ => None,
}
}
pub fn peel_refs(&self) -> &Self {
let mut final_ty = self;
while let TyKind::Ref(_, MutTy { ty, .. }) = &final_ty.kind {
final_ty = ty;
}
final_ty
}
pub fn find_self_aliases(&self) -> Vec<Span> {
use crate::intravisit::Visitor;
struct MyVisitor(Vec<Span>);
impl<'v> Visitor<'v> for MyVisitor {
fn visit_ty(&mut self, t: &'v Ty<'v>) {
if matches!(
&t.kind,
TyKind::Path(QPath::Resolved(
_,
Path { res: crate::def::Res::SelfTyAlias { .. }, .. },
))
) {
self.0.push(t.span);
return;
}
crate::intravisit::walk_ty(self, t);
}
}
let mut my_visitor = MyVisitor(vec![]);
my_visitor.visit_ty(self);
my_visitor.0
}
}
/// Not represented directly in the AST; referred to by name through a `ty_path`.
#[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Hash, Debug, HashStable_Generic)]
pub enum PrimTy {
Int(IntTy),
Uint(UintTy),
Float(FloatTy),
Str,
Bool,
Char,
}
impl PrimTy {
/// All of the primitive types
pub const ALL: [Self; 17] = [
// any changes here should also be reflected in `PrimTy::from_name`
Self::Int(IntTy::I8),
Self::Int(IntTy::I16),
Self::Int(IntTy::I32),
Self::Int(IntTy::I64),
Self::Int(IntTy::I128),
Self::Int(IntTy::Isize),
Self::Uint(UintTy::U8),
Self::Uint(UintTy::U16),
Self::Uint(UintTy::U32),
Self::Uint(UintTy::U64),
Self::Uint(UintTy::U128),
Self::Uint(UintTy::Usize),
Self::Float(FloatTy::F32),
Self::Float(FloatTy::F64),
Self::Bool,
Self::Char,
Self::Str,
];
/// Like [`PrimTy::name`], but returns a &str instead of a symbol.
///
/// Used by clippy.
pub fn name_str(self) -> &'static str {
match self {
PrimTy::Int(i) => i.name_str(),
PrimTy::Uint(u) => u.name_str(),
PrimTy::Float(f) => f.name_str(),
PrimTy::Str => "str",
PrimTy::Bool => "bool",
PrimTy::Char => "char",
}
}
pub fn name(self) -> Symbol {
match self {
PrimTy::Int(i) => i.name(),
PrimTy::Uint(u) => u.name(),
PrimTy::Float(f) => f.name(),
PrimTy::Str => sym::str,
PrimTy::Bool => sym::bool,
PrimTy::Char => sym::char,
}
}
/// Returns the matching `PrimTy` for a `Symbol` such as "str" or "i32".
/// Returns `None` if no matching type is found.
pub fn from_name(name: Symbol) -> Option<Self> {
let ty = match name {
// any changes here should also be reflected in `PrimTy::ALL`
sym::i8 => Self::Int(IntTy::I8),
sym::i16 => Self::Int(IntTy::I16),
sym::i32 => Self::Int(IntTy::I32),
sym::i64 => Self::Int(IntTy::I64),
sym::i128 => Self::Int(IntTy::I128),
sym::isize => Self::Int(IntTy::Isize),
sym::u8 => Self::Uint(UintTy::U8),
sym::u16 => Self::Uint(UintTy::U16),
sym::u32 => Self::Uint(UintTy::U32),
sym::u64 => Self::Uint(UintTy::U64),
sym::u128 => Self::Uint(UintTy::U128),
sym::usize => Self::Uint(UintTy::Usize),
sym::f32 => Self::Float(FloatTy::F32),
sym::f64 => Self::Float(FloatTy::F64),
sym::bool => Self::Bool,
sym::char => Self::Char,
sym::str => Self::Str,
_ => return None,
};
Some(ty)
}
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct BareFnTy<'hir> {
pub unsafety: Unsafety,
pub abi: Abi,
pub generic_params: &'hir [GenericParam<'hir>],
pub decl: &'hir FnDecl<'hir>,
pub param_names: &'hir [Ident],
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct OpaqueTy<'hir> {
pub generics: &'hir Generics<'hir>,
pub bounds: GenericBounds<'hir>,
pub origin: OpaqueTyOrigin,
/// Return-position impl traits (and async futures) must "reify" any late-bound
/// lifetimes that are captured from the function signature they originate from.
///
/// This is done by generating a new early-bound lifetime parameter local to the
/// opaque which is substituted in the function signature with the late-bound
/// lifetime.
///
/// This mapping associated a captured lifetime (first parameter) with the new
/// early-bound lifetime that was generated for the opaque.
pub lifetime_mapping: &'hir [(&'hir Lifetime, LocalDefId)],
/// Whether the opaque is a return-position impl trait (or async future)
/// originating from a trait method. This makes it so that the opaque is
/// lowered as an associated type.
pub in_trait: bool,
}
/// From whence the opaque type came.
#[derive(Copy, Clone, PartialEq, Eq, Debug, HashStable_Generic)]
pub enum OpaqueTyOrigin {
/// `-> impl Trait`
FnReturn(LocalDefId),
/// `async fn`
AsyncFn(LocalDefId),
/// type aliases: `type Foo = impl Trait;`
TyAlias {
/// associated types in impl blocks for traits.
in_assoc_ty: bool,
},
}
/// The various kinds of types recognized by the compiler.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum TyKind<'hir> {
/// A variable length slice (i.e., `[T]`).
Slice(&'hir Ty<'hir>),
/// A fixed length array (i.e., `[T; n]`).
Array(&'hir Ty<'hir>, ArrayLen),
/// A raw pointer (i.e., `*const T` or `*mut T`).
Ptr(MutTy<'hir>),
/// A reference (i.e., `&'a T` or `&'a mut T`).
Ref(&'hir Lifetime, MutTy<'hir>),
/// A bare function (e.g., `fn(usize) -> bool`).
BareFn(&'hir BareFnTy<'hir>),
/// The never type (`!`).
Never,
/// A tuple (`(A, B, C, D, ...)`).
Tup(&'hir [Ty<'hir>]),
/// A path to a type definition (`module::module::...::Type`), or an
/// associated type (e.g., `<Vec<T> as Trait>::Type` or `<T>::Target`).
///
/// Type parameters may be stored in each `PathSegment`.
Path(QPath<'hir>),
/// An opaque type definition itself. This is only used for `impl Trait`.
///
/// The generic argument list contains the lifetimes (and in the future
/// possibly parameters) that are actually bound on the `impl Trait`.
///
/// The last parameter specifies whether this opaque appears in a trait definition.
OpaqueDef(ItemId, &'hir [GenericArg<'hir>], bool),
/// A trait object type `Bound1 + Bound2 + Bound3`
/// where `Bound` is a trait or a lifetime.
TraitObject(&'hir [PolyTraitRef<'hir>], &'hir Lifetime, TraitObjectSyntax),
/// Unused for now.
Typeof(AnonConst),
/// `TyKind::Infer` means the type should be inferred instead of it having been
/// specified. This can appear anywhere in a type.
Infer,
/// Placeholder for a type that has failed to be defined.
Err(rustc_span::ErrorGuaranteed),
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum InlineAsmOperand<'hir> {
In {
reg: InlineAsmRegOrRegClass,
expr: &'hir Expr<'hir>,
},
Out {
reg: InlineAsmRegOrRegClass,
late: bool,
expr: Option<&'hir Expr<'hir>>,
},
InOut {
reg: InlineAsmRegOrRegClass,
late: bool,
expr: &'hir Expr<'hir>,
},
SplitInOut {
reg: InlineAsmRegOrRegClass,
late: bool,
in_expr: &'hir Expr<'hir>,
out_expr: Option<&'hir Expr<'hir>>,
},
Const {
anon_const: AnonConst,
},
SymFn {
anon_const: AnonConst,
},
SymStatic {
path: QPath<'hir>,
def_id: DefId,
},
}
impl<'hir> InlineAsmOperand<'hir> {
pub fn reg(&self) -> Option<InlineAsmRegOrRegClass> {
match *self {
Self::In { reg, .. }
| Self::Out { reg, .. }
| Self::InOut { reg, .. }
| Self::SplitInOut { reg, .. } => Some(reg),
Self::Const { .. } | Self::SymFn { .. } | Self::SymStatic { .. } => None,
}
}
pub fn is_clobber(&self) -> bool {
matches!(
self,
InlineAsmOperand::Out { reg: InlineAsmRegOrRegClass::Reg(_), late: _, expr: None }
)
}
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct InlineAsm<'hir> {
pub template: &'hir [InlineAsmTemplatePiece],
pub template_strs: &'hir [(Symbol, Option<Symbol>, Span)],
pub operands: &'hir [(InlineAsmOperand<'hir>, Span)],
pub options: InlineAsmOptions,
pub line_spans: &'hir [Span],
}
/// Represents a parameter in a function header.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Param<'hir> {
pub hir_id: HirId,
pub pat: &'hir Pat<'hir>,
pub ty_span: Span,
pub span: Span,
}
/// Represents the header (not the body) of a function declaration.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct FnDecl<'hir> {
/// The types of the function's parameters.
///
/// Additional argument data is stored in the function's [body](Body::params).
pub inputs: &'hir [Ty<'hir>],
pub output: FnRetTy<'hir>,
pub c_variadic: bool,
/// Does the function have an implicit self?
pub implicit_self: ImplicitSelfKind,
/// Is lifetime elision allowed.
pub lifetime_elision_allowed: bool,
}
/// Represents what type of implicit self a function has, if any.
#[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
pub enum ImplicitSelfKind {
/// Represents a `fn x(self);`.
Imm,
/// Represents a `fn x(mut self);`.
Mut,
/// Represents a `fn x(&self);`.
ImmRef,
/// Represents a `fn x(&mut self);`.
MutRef,
/// Represents when a function does not have a self argument or
/// when a function has a `self: X` argument.
None,
}
impl ImplicitSelfKind {
/// Does this represent an implicit self?
pub fn has_implicit_self(&self) -> bool {
!matches!(*self, ImplicitSelfKind::None)
}
}
#[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
pub enum IsAsync {
Async(Span),
NotAsync,
}
impl IsAsync {
pub fn is_async(self) -> bool {
matches!(self, IsAsync::Async(_))
}
}
#[derive(Copy, Clone, PartialEq, Eq, Debug, Encodable, Decodable, HashStable_Generic)]
pub enum Defaultness {
Default { has_value: bool },
Final,
}
impl Defaultness {
pub fn has_value(&self) -> bool {
match *self {
Defaultness::Default { has_value } => has_value,
Defaultness::Final => true,
}
}
pub fn is_final(&self) -> bool {
*self == Defaultness::Final
}
pub fn is_default(&self) -> bool {
matches!(*self, Defaultness::Default { .. })
}
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum FnRetTy<'hir> {
/// Return type is not specified.
///
/// Functions default to `()` and
/// closures default to inference. Span points to where return
/// type would be inserted.
DefaultReturn(Span),
/// Everything else.
Return(&'hir Ty<'hir>),
}
impl FnRetTy<'_> {
#[inline]
pub fn span(&self) -> Span {
match *self {
Self::DefaultReturn(span) => span,
Self::Return(ref ty) => ty.span,
}
}
}
/// Represents `for<...>` binder before a closure
#[derive(Copy, Clone, Debug, HashStable_Generic)]
pub enum ClosureBinder {
/// Binder is not specified.
Default,
/// Binder is specified.
///
/// Span points to the whole `for<...>`.
For { span: Span },
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Mod<'hir> {
pub spans: ModSpans,
pub item_ids: &'hir [ItemId],
}
#[derive(Copy, Clone, Debug, HashStable_Generic)]
pub struct ModSpans {
/// 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: Span,
pub inject_use_span: Span,
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct EnumDef<'hir> {
pub variants: &'hir [Variant<'hir>],
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Variant<'hir> {
/// Name of the variant.
pub ident: Ident,
/// Id of the variant (not the constructor, see `VariantData::ctor_hir_id()`).
pub hir_id: HirId,
pub def_id: LocalDefId,
/// Fields and constructor id of the variant.
pub data: VariantData<'hir>,
/// Explicit discriminant (e.g., `Foo = 1`).
pub disr_expr: Option<AnonConst>,
/// Span
pub span: Span,
}
#[derive(Copy, Clone, PartialEq, Debug, HashStable_Generic)]
pub enum UseKind {
/// One import, e.g., `use foo::bar` or `use foo::bar as baz`.
/// Also produced for each element of a list `use`, e.g.
/// `use foo::{a, b}` lowers to `use foo::a; use foo::b;`.
Single,
/// Glob import, e.g., `use foo::*`.
Glob,
/// Degenerate list import, e.g., `use foo::{a, b}` produces
/// an additional `use foo::{}` for performing checks such as
/// unstable feature gating. May be removed in the future.
ListStem,
}
/// References to traits in impls.
///
/// `resolve` maps each `TraitRef`'s `ref_id` to its defining trait; that's all
/// that the `ref_id` is for. Note that `ref_id`'s value is not the `HirId` of the
/// trait being referred to but just a unique `HirId` that serves as a key
/// within the resolution map.
#[derive(Clone, Debug, Copy, HashStable_Generic)]
pub struct TraitRef<'hir> {
pub path: &'hir Path<'hir>,
// Don't hash the `ref_id`. It is tracked via the thing it is used to access.
#[stable_hasher(ignore)]
pub hir_ref_id: HirId,
}
impl TraitRef<'_> {
/// Gets the `DefId` of the referenced trait. It _must_ actually be a trait or trait alias.
pub fn trait_def_id(&self) -> Option<DefId> {
match self.path.res {
Res::Def(DefKind::Trait | DefKind::TraitAlias, did) => Some(did),
Res::Err => None,
res => panic!("{res:?} did not resolve to a trait or trait alias"),
}
}
}
#[derive(Clone, Debug, Copy, HashStable_Generic)]
pub struct PolyTraitRef<'hir> {
/// The `'a` in `for<'a> Foo<&'a T>`.
pub bound_generic_params: &'hir [GenericParam<'hir>],
/// The `Foo<&'a T>` in `for<'a> Foo<&'a T>`.
pub trait_ref: TraitRef<'hir>,
pub span: Span,
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct FieldDef<'hir> {
pub span: Span,
pub vis_span: Span,
pub ident: Ident,
pub hir_id: HirId,
pub def_id: LocalDefId,
pub ty: &'hir Ty<'hir>,
}
impl FieldDef<'_> {
// Still necessary in couple of places
pub fn is_positional(&self) -> bool {
self.ident.as_str().as_bytes()[0].is_ascii_digit()
}
}
/// Fields and constructor IDs of enum variants and structs.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum VariantData<'hir> {
/// A struct variant.
///
/// E.g., `Bar { .. }` as in `enum Foo { Bar { .. } }`.
Struct {
fields: &'hir [FieldDef<'hir>],
// FIXME: investigate making this a `Option<ErrorGuaranteed>`
recovered: bool,
},
/// A tuple variant.
///
/// E.g., `Bar(..)` as in `enum Foo { Bar(..) }`.
Tuple(&'hir [FieldDef<'hir>], HirId, LocalDefId),
/// A unit variant.
///
/// E.g., `Bar = ..` as in `enum Foo { Bar = .. }`.
Unit(HirId, LocalDefId),
}
impl<'hir> VariantData<'hir> {
/// Return the fields of this variant.
pub fn fields(&self) -> &'hir [FieldDef<'hir>] {
match *self {
VariantData::Struct { fields, .. } | VariantData::Tuple(fields, ..) => fields,
_ => &[],
}
}
pub fn ctor(&self) -> Option<(CtorKind, HirId, LocalDefId)> {
match *self {
VariantData::Tuple(_, hir_id, def_id) => Some((CtorKind::Fn, hir_id, def_id)),
VariantData::Unit(hir_id, def_id) => Some((CtorKind::Const, hir_id, def_id)),
VariantData::Struct { .. } => None,
}
}
#[inline]
pub fn ctor_kind(&self) -> Option<CtorKind> {
self.ctor().map(|(kind, ..)| kind)
}
/// Return the `HirId` of this variant's constructor, if it has one.
#[inline]
pub fn ctor_hir_id(&self) -> Option<HirId> {
self.ctor().map(|(_, hir_id, _)| hir_id)
}
/// Return the `LocalDefId` of this variant's constructor, if it has one.
#[inline]
pub fn ctor_def_id(&self) -> Option<LocalDefId> {
self.ctor().map(|(.., def_id)| def_id)
}
}
// The bodies for items are stored "out of line", in a separate
// hashmap in the `Crate`. Here we just record the hir-id of the item
// so it can fetched later.
#[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, Hash, HashStable_Generic)]
pub struct ItemId {
pub owner_id: OwnerId,
}
impl ItemId {
#[inline]
pub fn hir_id(&self) -> HirId {
// Items are always HIR owners.
HirId::make_owner(self.owner_id.def_id)
}
}
/// An item
///
/// The name might be a dummy name in case of anonymous items
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Item<'hir> {
pub ident: Ident,
pub owner_id: OwnerId,
pub kind: ItemKind<'hir>,
pub span: Span,
pub vis_span: Span,
}
impl<'hir> Item<'hir> {
#[inline]
pub fn hir_id(&self) -> HirId {
// Items are always HIR owners.
HirId::make_owner(self.owner_id.def_id)
}
pub fn item_id(&self) -> ItemId {
ItemId { owner_id: self.owner_id }
}
expect_methods_self_kind! {
expect_extern_crate, Option<Symbol>, ItemKind::ExternCrate(s), *s;
expect_use, (&'hir UsePath<'hir>, UseKind), ItemKind::Use(p, uk), (p, *uk);
expect_static, (&'hir Ty<'hir>, Mutability, BodyId),
ItemKind::Static(ty, mutbl, body), (ty, *mutbl, *body);
expect_const, (&'hir Ty<'hir>, &'hir Generics<'hir>, BodyId),
ItemKind::Const(ty, gen, body), (ty, gen, *body);
expect_fn, (&FnSig<'hir>, &'hir Generics<'hir>, BodyId),
ItemKind::Fn(sig, gen, body), (sig, gen, *body);
expect_macro, (&ast::MacroDef, MacroKind), ItemKind::Macro(def, mk), (def, *mk);
expect_mod, &'hir Mod<'hir>, ItemKind::Mod(m), m;
expect_foreign_mod, (Abi, &'hir [ForeignItemRef]),
ItemKind::ForeignMod { abi, items }, (*abi, items);
expect_global_asm, &'hir InlineAsm<'hir>, ItemKind::GlobalAsm(asm), asm;
expect_ty_alias, (&'hir Ty<'hir>, &'hir Generics<'hir>),
ItemKind::TyAlias(ty, gen), (ty, gen);
expect_opaque_ty, &OpaqueTy<'hir>, ItemKind::OpaqueTy(ty), ty;
expect_enum, (&EnumDef<'hir>, &'hir Generics<'hir>), ItemKind::Enum(def, gen), (def, gen);
expect_struct, (&VariantData<'hir>, &'hir Generics<'hir>),
ItemKind::Struct(data, gen), (data, gen);
expect_union, (&VariantData<'hir>, &'hir Generics<'hir>),
ItemKind::Union(data, gen), (data, gen);
expect_trait,
(IsAuto, Unsafety, &'hir Generics<'hir>, GenericBounds<'hir>, &'hir [TraitItemRef]),
ItemKind::Trait(is_auto, unsafety, gen, bounds, items),
(*is_auto, *unsafety, gen, bounds, items);
expect_trait_alias, (&'hir Generics<'hir>, GenericBounds<'hir>),
ItemKind::TraitAlias(gen, bounds), (gen, bounds);
expect_impl, &'hir Impl<'hir>, ItemKind::Impl(imp), imp;
}
}
#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
#[derive(Encodable, Decodable, HashStable_Generic)]
pub enum Unsafety {
Unsafe,
Normal,
}
impl Unsafety {
pub fn prefix_str(&self) -> &'static str {
match self {
Self::Unsafe => "unsafe ",
Self::Normal => "",
}
}
}
impl fmt::Display for Unsafety {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_str(match *self {
Self::Unsafe => "unsafe",
Self::Normal => "normal",
})
}
}
#[derive(Copy, Clone, PartialEq, Eq, Debug, Encodable, Decodable, HashStable_Generic)]
pub enum Constness {
Const,
NotConst,
}
impl fmt::Display for Constness {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.write_str(match *self {
Self::Const => "const",
Self::NotConst => "non-const",
})
}
}
#[derive(Copy, Clone, Debug, HashStable_Generic)]
pub struct FnHeader {
pub unsafety: Unsafety,
pub constness: Constness,
pub asyncness: IsAsync,
pub abi: Abi,
}
impl FnHeader {
pub fn is_async(&self) -> bool {
matches!(&self.asyncness, IsAsync::Async(_))
}
pub fn is_const(&self) -> bool {
matches!(&self.constness, Constness::Const)
}
pub fn is_unsafe(&self) -> bool {
matches!(&self.unsafety, Unsafety::Unsafe)
}
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum ItemKind<'hir> {
/// An `extern crate` item, with optional *original* crate name if the crate was renamed.
///
/// E.g., `extern crate foo` or `extern crate foo_bar as foo`.
ExternCrate(Option<Symbol>),
/// `use foo::bar::*;` or `use foo::bar::baz as quux;`
///
/// or just
///
/// `use foo::bar::baz;` (with `as baz` implicitly on the right).
Use(&'hir UsePath<'hir>, UseKind),
/// A `static` item.
Static(&'hir Ty<'hir>, Mutability, BodyId),
/// A `const` item.
Const(&'hir Ty<'hir>, &'hir Generics<'hir>, BodyId),
/// A function declaration.
Fn(FnSig<'hir>, &'hir Generics<'hir>, BodyId),
/// A MBE macro definition (`macro_rules!` or `macro`).
Macro(&'hir ast::MacroDef, MacroKind),
/// A module.
Mod(&'hir Mod<'hir>),
/// An external module, e.g. `extern { .. }`.
ForeignMod { abi: Abi, items: &'hir [ForeignItemRef] },
/// Module-level inline assembly (from `global_asm!`).
GlobalAsm(&'hir InlineAsm<'hir>),
/// A type alias, e.g., `type Foo = Bar<u8>`.
TyAlias(&'hir Ty<'hir>, &'hir Generics<'hir>),
/// An opaque `impl Trait` type alias, e.g., `type Foo = impl Bar;`.
OpaqueTy(&'hir OpaqueTy<'hir>),
/// An enum definition, e.g., `enum Foo<A, B> {C<A>, D<B>}`.
Enum(EnumDef<'hir>, &'hir Generics<'hir>),
/// A struct definition, e.g., `struct Foo<A> {x: A}`.
Struct(VariantData<'hir>, &'hir Generics<'hir>),
/// A union definition, e.g., `union Foo<A, B> {x: A, y: B}`.
Union(VariantData<'hir>, &'hir Generics<'hir>),
/// A trait definition.
Trait(IsAuto, Unsafety, &'hir Generics<'hir>, GenericBounds<'hir>, &'hir [TraitItemRef]),
/// A trait alias.
TraitAlias(&'hir Generics<'hir>, GenericBounds<'hir>),
/// An implementation, e.g., `impl<A> Trait for Foo { .. }`.
Impl(&'hir Impl<'hir>),
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct Impl<'hir> {
pub unsafety: Unsafety,
pub polarity: ImplPolarity,
pub defaultness: Defaultness,
// We do not put a `Span` in `Defaultness` because it breaks foreign crate metadata
// decoding as `Span`s cannot be decoded when a `Session` is not available.
pub defaultness_span: Option<Span>,
pub generics: &'hir Generics<'hir>,
/// The trait being implemented, if any.
pub of_trait: Option<TraitRef<'hir>>,
pub self_ty: &'hir Ty<'hir>,
pub items: &'hir [ImplItemRef],
}
impl ItemKind<'_> {
pub fn generics(&self) -> Option<&Generics<'_>> {
Some(match *self {
ItemKind::Fn(_, ref generics, _)
| ItemKind::TyAlias(_, ref generics)
| ItemKind::Const(_, ref generics, _)
| ItemKind::OpaqueTy(OpaqueTy { ref generics, .. })
| ItemKind::Enum(_, ref generics)
| ItemKind::Struct(_, ref generics)
| ItemKind::Union(_, ref generics)
| ItemKind::Trait(_, _, ref generics, _, _)
| ItemKind::TraitAlias(ref generics, _)
| ItemKind::Impl(Impl { ref generics, .. }) => generics,
_ => return None,
})
}
pub fn descr(&self) -> &'static str {
match self {
ItemKind::ExternCrate(..) => "extern crate",
ItemKind::Use(..) => "`use` import",
ItemKind::Static(..) => "static item",
ItemKind::Const(..) => "constant item",
ItemKind::Fn(..) => "function",
ItemKind::Macro(..) => "macro",
ItemKind::Mod(..) => "module",
ItemKind::ForeignMod { .. } => "extern block",
ItemKind::GlobalAsm(..) => "global asm item",
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::Impl(..) => "implementation",
}
}
}
/// A reference from an trait to one of its associated items. This
/// contains the item's id, naturally, but also the item's name and
/// some other high-level details (like whether it is an associated
/// type or method, and whether it is public). This allows other
/// passes to find the impl they want without loading the ID (which
/// means fewer edges in the incremental compilation graph).
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct TraitItemRef {
pub id: TraitItemId,
pub ident: Ident,
pub kind: AssocItemKind,
pub span: Span,
}
/// A reference from an impl to one of its associated items. This
/// contains the item's ID, naturally, but also the item's name and
/// some other high-level details (like whether it is an associated
/// type or method, and whether it is public). This allows other
/// passes to find the impl they want without loading the ID (which
/// means fewer edges in the incremental compilation graph).
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct ImplItemRef {
pub id: ImplItemId,
pub ident: Ident,
pub kind: AssocItemKind,
pub span: Span,
/// When we are in a trait impl, link to the trait-item's id.
pub trait_item_def_id: Option<DefId>,
}
#[derive(Copy, Clone, PartialEq, Debug, HashStable_Generic)]
pub enum AssocItemKind {
Const,
Fn { has_self: bool },
Type,
}
// The bodies for items are stored "out of line", in a separate
// hashmap in the `Crate`. Here we just record the hir-id of the item
// so it can fetched later.
#[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
pub struct ForeignItemId {
pub owner_id: OwnerId,
}
impl ForeignItemId {
#[inline]
pub fn hir_id(&self) -> HirId {
// Items are always HIR owners.
HirId::make_owner(self.owner_id.def_id)
}
}
/// A reference from a foreign block to one of its items. This
/// contains the item's ID, naturally, but also the item's name and
/// some other high-level details (like whether it is an associated
/// type or method, and whether it is public). This allows other
/// passes to find the impl they want without loading the ID (which
/// means fewer edges in the incremental compilation graph).
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct ForeignItemRef {
pub id: ForeignItemId,
pub ident: Ident,
pub span: Span,
}
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub struct ForeignItem<'hir> {
pub ident: Ident,
pub kind: ForeignItemKind<'hir>,
pub owner_id: OwnerId,
pub span: Span,
pub vis_span: Span,
}
impl ForeignItem<'_> {
#[inline]
pub fn hir_id(&self) -> HirId {
// Items are always HIR owners.
HirId::make_owner(self.owner_id.def_id)
}
pub fn foreign_item_id(&self) -> ForeignItemId {
ForeignItemId { owner_id: self.owner_id }
}
}
/// An item within an `extern` block.
#[derive(Debug, Clone, Copy, HashStable_Generic)]
pub enum ForeignItemKind<'hir> {
/// A foreign function.
Fn(&'hir FnDecl<'hir>, &'hir [Ident], &'hir Generics<'hir>),
/// A foreign static item (`static ext: u8`).
Static(&'hir Ty<'hir>, Mutability),
/// A foreign type.
Type,
}
/// A variable captured by a closure.
#[derive(Debug, Copy, Clone, HashStable_Generic)]
pub struct Upvar {
/// First span where it is accessed (there can be multiple).
pub span: Span,
}
// The TraitCandidate's import_ids is empty if the trait is defined in the same module, and
// has length > 0 if the trait is found through an chain of imports, starting with the
// import/use statement in the scope where the trait is used.
#[derive(Debug, Clone, HashStable_Generic)]
pub struct TraitCandidate {
pub def_id: DefId,
pub import_ids: SmallVec<[LocalDefId; 1]>,
}
#[derive(Copy, Clone, Debug, HashStable_Generic)]
pub enum OwnerNode<'hir> {
Item(&'hir Item<'hir>),
ForeignItem(&'hir ForeignItem<'hir>),
TraitItem(&'hir TraitItem<'hir>),
ImplItem(&'hir ImplItem<'hir>),
Crate(&'hir Mod<'hir>),
}
impl<'hir> OwnerNode<'hir> {
pub fn ident(&self) -> Option<Ident> {
match self {
OwnerNode::Item(Item { ident, .. })
| OwnerNode::ForeignItem(ForeignItem { ident, .. })
| OwnerNode::ImplItem(ImplItem { ident, .. })
| OwnerNode::TraitItem(TraitItem { ident, .. }) => Some(*ident),
OwnerNode::Crate(..) => None,
}
}
pub fn span(&self) -> Span {
match self {
OwnerNode::Item(Item { span, .. })
| OwnerNode::ForeignItem(ForeignItem { span, .. })
| OwnerNode::ImplItem(ImplItem { span, .. })
| OwnerNode::TraitItem(TraitItem { span, .. }) => *span,
OwnerNode::Crate(Mod { spans: ModSpans { inner_span, .. }, .. }) => *inner_span,
}
}
pub fn fn_sig(self) -> Option<&'hir FnSig<'hir>> {
match self {
OwnerNode::TraitItem(TraitItem { kind: TraitItemKind::Fn(fn_sig, _), .. })
| OwnerNode::ImplItem(ImplItem { kind: ImplItemKind::Fn(fn_sig, _), .. })
| OwnerNode::Item(Item { kind: ItemKind::Fn(fn_sig, _, _), .. }) => Some(fn_sig),
_ => None,
}
}
pub fn fn_decl(self) -> Option<&'hir FnDecl<'hir>> {
match self {
OwnerNode::TraitItem(TraitItem { kind: TraitItemKind::Fn(fn_sig, _), .. })
| OwnerNode::ImplItem(ImplItem { kind: ImplItemKind::Fn(fn_sig, _), .. })
| OwnerNode::Item(Item { kind: ItemKind::Fn(fn_sig, _, _), .. }) => Some(fn_sig.decl),
OwnerNode::ForeignItem(ForeignItem {
kind: ForeignItemKind::Fn(fn_decl, _, _),
..
}) => Some(fn_decl),
_ => None,
}
}
pub fn body_id(&self) -> Option<BodyId> {
match self {
OwnerNode::Item(Item {
kind:
ItemKind::Static(_, _, body)
| ItemKind::Const(_, _, body)
| ItemKind::Fn(_, _, body),
..
})
| OwnerNode::TraitItem(TraitItem {
kind:
TraitItemKind::Fn(_, TraitFn::Provided(body)) | TraitItemKind::Const(_, Some(body)),
..
})
| OwnerNode::ImplItem(ImplItem {
kind: ImplItemKind::Fn(_, body) | ImplItemKind::Const(_, body),
..
}) => Some(*body),
_ => None,
}
}
pub fn generics(self) -> Option<&'hir Generics<'hir>> {
Node::generics(self.into())
}
pub fn def_id(self) -> OwnerId {
match self {
OwnerNode::Item(Item { owner_id, .. })
| OwnerNode::TraitItem(TraitItem { owner_id, .. })
| OwnerNode::ImplItem(ImplItem { owner_id, .. })
| OwnerNode::ForeignItem(ForeignItem { owner_id, .. }) => *owner_id,
OwnerNode::Crate(..) => crate::CRATE_HIR_ID.owner,
}
}
expect_methods_self! {
expect_item, &'hir Item<'hir>, OwnerNode::Item(n), n;
expect_foreign_item, &'hir ForeignItem<'hir>, OwnerNode::ForeignItem(n), n;
expect_impl_item, &'hir ImplItem<'hir>, OwnerNode::ImplItem(n), n;
expect_trait_item, &'hir TraitItem<'hir>, OwnerNode::TraitItem(n), n;
}
}
impl<'hir> Into<OwnerNode<'hir>> for &'hir Item<'hir> {
fn into(self) -> OwnerNode<'hir> {
OwnerNode::Item(self)
}
}
impl<'hir> Into<OwnerNode<'hir>> for &'hir ForeignItem<'hir> {
fn into(self) -> OwnerNode<'hir> {
OwnerNode::ForeignItem(self)
}
}
impl<'hir> Into<OwnerNode<'hir>> for &'hir ImplItem<'hir> {
fn into(self) -> OwnerNode<'hir> {
OwnerNode::ImplItem(self)
}
}
impl<'hir> Into<OwnerNode<'hir>> for &'hir TraitItem<'hir> {
fn into(self) -> OwnerNode<'hir> {
OwnerNode::TraitItem(self)
}
}
impl<'hir> Into<Node<'hir>> for OwnerNode<'hir> {
fn into(self) -> Node<'hir> {
match self {
OwnerNode::Item(n) => Node::Item(n),
OwnerNode::ForeignItem(n) => Node::ForeignItem(n),
OwnerNode::ImplItem(n) => Node::ImplItem(n),
OwnerNode::TraitItem(n) => Node::TraitItem(n),
OwnerNode::Crate(n) => Node::Crate(n),
}
}
}
#[derive(Copy, Clone, Debug, HashStable_Generic)]
pub enum Node<'hir> {
Param(&'hir Param<'hir>),
Item(&'hir Item<'hir>),
ForeignItem(&'hir ForeignItem<'hir>),
TraitItem(&'hir TraitItem<'hir>),
ImplItem(&'hir ImplItem<'hir>),
Variant(&'hir Variant<'hir>),
Field(&'hir FieldDef<'hir>),
AnonConst(&'hir AnonConst),
ConstBlock(&'hir ConstBlock),
Expr(&'hir Expr<'hir>),
ExprField(&'hir ExprField<'hir>),
Stmt(&'hir Stmt<'hir>),
PathSegment(&'hir PathSegment<'hir>),
Ty(&'hir Ty<'hir>),
TypeBinding(&'hir TypeBinding<'hir>),
TraitRef(&'hir TraitRef<'hir>),
Pat(&'hir Pat<'hir>),
PatField(&'hir PatField<'hir>),
Arm(&'hir Arm<'hir>),
Block(&'hir Block<'hir>),
Local(&'hir Local<'hir>),
/// `Ctor` refers to the constructor of an enum variant or struct. Only tuple or unit variants
/// with synthesized constructors.
Ctor(&'hir VariantData<'hir>),
Lifetime(&'hir Lifetime),
GenericParam(&'hir GenericParam<'hir>),
Crate(&'hir Mod<'hir>),
Infer(&'hir InferArg),
}
impl<'hir> Node<'hir> {
/// Get the identifier of this `Node`, if applicable.
///
/// # Edge cases
///
/// Calling `.ident()` on a [`Node::Ctor`] will return `None`
/// because `Ctor`s do not have identifiers themselves.
/// Instead, call `.ident()` on the parent struct/variant, like so:
///
/// ```ignore (illustrative)
/// ctor
/// .ctor_hir_id()
/// .and_then(|ctor_id| tcx.hir().find_parent(ctor_id))
/// .and_then(|parent| parent.ident())
/// ```
pub fn ident(&self) -> Option<Ident> {
match self {
Node::TraitItem(TraitItem { ident, .. })
| Node::ImplItem(ImplItem { ident, .. })
| Node::ForeignItem(ForeignItem { ident, .. })
| Node::Field(FieldDef { ident, .. })
| Node::Variant(Variant { ident, .. })
| Node::Item(Item { ident, .. })
| Node::PathSegment(PathSegment { ident, .. }) => Some(*ident),
Node::Lifetime(lt) => Some(lt.ident),
Node::GenericParam(p) => Some(p.name.ident()),
Node::TypeBinding(b) => Some(b.ident),
Node::PatField(f) => Some(f.ident),
Node::ExprField(f) => Some(f.ident),
Node::Param(..)
| Node::AnonConst(..)
| Node::ConstBlock(..)
| Node::Expr(..)
| Node::Stmt(..)
| Node::Block(..)
| Node::Ctor(..)
| Node::Pat(..)
| Node::Arm(..)
| Node::Local(..)
| Node::Crate(..)
| Node::Ty(..)
| Node::TraitRef(..)
| Node::Infer(..) => None,
}
}
pub fn fn_decl(self) -> Option<&'hir FnDecl<'hir>> {
match self {
Node::TraitItem(TraitItem { kind: TraitItemKind::Fn(fn_sig, _), .. })
| Node::ImplItem(ImplItem { kind: ImplItemKind::Fn(fn_sig, _), .. })
| Node::Item(Item { kind: ItemKind::Fn(fn_sig, _, _), .. }) => Some(fn_sig.decl),
Node::Expr(Expr { kind: ExprKind::Closure(Closure { fn_decl, .. }), .. })
| Node::ForeignItem(ForeignItem { kind: ForeignItemKind::Fn(fn_decl, _, _), .. }) => {
Some(fn_decl)
}
_ => None,
}
}
pub fn fn_sig(self) -> Option<&'hir FnSig<'hir>> {
match self {
Node::TraitItem(TraitItem { kind: TraitItemKind::Fn(fn_sig, _), .. })
| Node::ImplItem(ImplItem { kind: ImplItemKind::Fn(fn_sig, _), .. })
| Node::Item(Item { kind: ItemKind::Fn(fn_sig, _, _), .. }) => Some(fn_sig),
_ => None,
}
}
/// Get the type for constants, assoc types, type aliases and statics.
pub fn ty(self) -> Option<&'hir Ty<'hir>> {
match self {
Node::Item(it) => match it.kind {
ItemKind::TyAlias(ty, _)
| ItemKind::Static(ty, _, _)
| ItemKind::Const(ty, _, _) => Some(ty),
ItemKind::Impl(impl_item) => Some(&impl_item.self_ty),
_ => None,
},
Node::TraitItem(it) => match it.kind {
TraitItemKind::Const(ty, _) => Some(ty),
TraitItemKind::Type(_, ty) => ty,
_ => None,
},
Node::ImplItem(it) => match it.kind {
ImplItemKind::Const(ty, _) => Some(ty),
ImplItemKind::Type(ty) => Some(ty),
_ => None,
},
_ => None,
}
}
pub fn alias_ty(self) -> Option<&'hir Ty<'hir>> {
match self {
Node::Item(Item { kind: ItemKind::TyAlias(ty, ..), .. }) => Some(ty),
_ => None,
}
}
pub fn body_id(&self) -> Option<BodyId> {
match self {
Node::Item(Item {
kind:
ItemKind::Static(_, _, body)
| ItemKind::Const(_, _, body)
| ItemKind::Fn(_, _, body),
..
})
| Node::TraitItem(TraitItem {
kind:
TraitItemKind::Fn(_, TraitFn::Provided(body)) | TraitItemKind::Const(_, Some(body)),
..
})
| Node::ImplItem(ImplItem {
kind: ImplItemKind::Fn(_, body) | ImplItemKind::Const(_, body),
..
})
| Node::Expr(Expr {
kind:
ExprKind::ConstBlock(ConstBlock { body, .. })
| ExprKind::Closure(Closure { body, .. })
| ExprKind::Repeat(_, ArrayLen::Body(AnonConst { body, .. })),
..
}) => Some(*body),
_ => None,
}
}
pub fn generics(self) -> Option<&'hir Generics<'hir>> {
match self {
Node::ForeignItem(ForeignItem {
kind: ForeignItemKind::Fn(_, _, generics), ..
})
| Node::TraitItem(TraitItem { generics, .. })
| Node::ImplItem(ImplItem { generics, .. }) => Some(generics),
Node::Item(item) => item.kind.generics(),
_ => None,
}
}
pub fn as_owner(self) -> Option<OwnerNode<'hir>> {
match self {
Node::Item(i) => Some(OwnerNode::Item(i)),
Node::ForeignItem(i) => Some(OwnerNode::ForeignItem(i)),
Node::TraitItem(i) => Some(OwnerNode::TraitItem(i)),
Node::ImplItem(i) => Some(OwnerNode::ImplItem(i)),
Node::Crate(i) => Some(OwnerNode::Crate(i)),
_ => None,
}
}
pub fn fn_kind(self) -> Option<FnKind<'hir>> {
match self {
Node::Item(i) => match i.kind {
ItemKind::Fn(ref sig, ref generics, _) => {
Some(FnKind::ItemFn(i.ident, generics, sig.header))
}
_ => None,
},
Node::TraitItem(ti) => match ti.kind {
TraitItemKind::Fn(ref sig, TraitFn::Provided(_)) => {
Some(FnKind::Method(ti.ident, sig))
}
_ => None,
},
Node::ImplItem(ii) => match ii.kind {
ImplItemKind::Fn(ref sig, _) => Some(FnKind::Method(ii.ident, sig)),
_ => None,
},
Node::Expr(e) => match e.kind {
ExprKind::Closure { .. } => Some(FnKind::Closure),
_ => None,
},
_ => None,
}
}
expect_methods_self! {
expect_param, &'hir Param<'hir>, Node::Param(n), n;
expect_item, &'hir Item<'hir>, Node::Item(n), n;
expect_foreign_item, &'hir ForeignItem<'hir>, Node::ForeignItem(n), n;
expect_trait_item, &'hir TraitItem<'hir>, Node::TraitItem(n), n;
expect_impl_item, &'hir ImplItem<'hir>, Node::ImplItem(n), n;
expect_variant, &'hir Variant<'hir>, Node::Variant(n), n;
expect_field, &'hir FieldDef<'hir>, Node::Field(n), n;
expect_anon_const, &'hir AnonConst, Node::AnonConst(n), n;
expect_inline_const, &'hir ConstBlock, Node::ConstBlock(n), n;
expect_expr, &'hir Expr<'hir>, Node::Expr(n), n;
expect_expr_field, &'hir ExprField<'hir>, Node::ExprField(n), n;
expect_stmt, &'hir Stmt<'hir>, Node::Stmt(n), n;
expect_path_segment, &'hir PathSegment<'hir>, Node::PathSegment(n), n;
expect_ty, &'hir Ty<'hir>, Node::Ty(n), n;
expect_type_binding, &'hir TypeBinding<'hir>, Node::TypeBinding(n), n;
expect_trait_ref, &'hir TraitRef<'hir>, Node::TraitRef(n), n;
expect_pat, &'hir Pat<'hir>, Node::Pat(n), n;
expect_pat_field, &'hir PatField<'hir>, Node::PatField(n), n;
expect_arm, &'hir Arm<'hir>, Node::Arm(n), n;
expect_block, &'hir Block<'hir>, Node::Block(n), n;
expect_local, &'hir Local<'hir>, Node::Local(n), n;
expect_ctor, &'hir VariantData<'hir>, Node::Ctor(n), n;
expect_lifetime, &'hir Lifetime, Node::Lifetime(n), n;
expect_generic_param, &'hir GenericParam<'hir>, Node::GenericParam(n), n;
expect_crate, &'hir Mod<'hir>, Node::Crate(n), n;
expect_infer, &'hir InferArg, Node::Infer(n), n;
}
}
// Some nodes are used a lot. Make sure they don't unintentionally get bigger.
#[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
mod size_asserts {
use super::*;
// tidy-alphabetical-start
static_assert_size!(Block<'_>, 48);
static_assert_size!(Body<'_>, 32);
static_assert_size!(Expr<'_>, 64);
static_assert_size!(ExprKind<'_>, 48);
static_assert_size!(FnDecl<'_>, 40);
static_assert_size!(ForeignItem<'_>, 72);
static_assert_size!(ForeignItemKind<'_>, 40);
static_assert_size!(GenericArg<'_>, 32);
static_assert_size!(GenericBound<'_>, 48);
static_assert_size!(Generics<'_>, 56);
static_assert_size!(Impl<'_>, 80);
static_assert_size!(ImplItem<'_>, 88);
static_assert_size!(ImplItemKind<'_>, 40);
static_assert_size!(Item<'_>, 88);
static_assert_size!(ItemKind<'_>, 56);
static_assert_size!(Local<'_>, 64);
static_assert_size!(Param<'_>, 32);
static_assert_size!(Pat<'_>, 72);
static_assert_size!(Path<'_>, 40);
static_assert_size!(PathSegment<'_>, 48);
static_assert_size!(PatKind<'_>, 48);
static_assert_size!(QPath<'_>, 24);
static_assert_size!(Res, 12);
static_assert_size!(Stmt<'_>, 32);
static_assert_size!(StmtKind<'_>, 16);
static_assert_size!(TraitItem<'_>, 88);
static_assert_size!(TraitItemKind<'_>, 48);
static_assert_size!(Ty<'_>, 48);
static_assert_size!(TyKind<'_>, 32);
// tidy-alphabetical-end
}
fn debug_fn(f: impl Fn(&mut fmt::Formatter<'_>) -> fmt::Result) -> impl fmt::Debug {
struct DebugFn<F>(F);
impl<F: Fn(&mut fmt::Formatter<'_>) -> fmt::Result> fmt::Debug for DebugFn<F> {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
(self.0)(fmt)
}
}
DebugFn(f)
}
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