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-rw-r--r--compiler/rustc_hir/src/arena.rs55
-rw-r--r--compiler/rustc_hir/src/def.rs749
-rw-r--r--compiler/rustc_hir/src/def_path_hash_map.rs37
-rw-r--r--compiler/rustc_hir/src/definitions.rs440
-rw-r--r--compiler/rustc_hir/src/diagnostic_items.rs17
-rw-r--r--compiler/rustc_hir/src/hir.rs3506
-rw-r--r--compiler/rustc_hir/src/hir_id.rs89
-rw-r--r--compiler/rustc_hir/src/intravisit.rs1232
-rw-r--r--compiler/rustc_hir/src/lang_items.rs339
-rw-r--r--compiler/rustc_hir/src/lib.rs47
-rw-r--r--compiler/rustc_hir/src/pat_util.rs157
-rw-r--r--compiler/rustc_hir/src/stable_hash_impls.rs143
-rw-r--r--compiler/rustc_hir/src/target.rs188
-rw-r--r--compiler/rustc_hir/src/tests.rs36
-rw-r--r--compiler/rustc_hir/src/weak_lang_items.rs47
15 files changed, 7082 insertions, 0 deletions
diff --git a/compiler/rustc_hir/src/arena.rs b/compiler/rustc_hir/src/arena.rs
new file mode 100644
index 000000000..44335b7f4
--- /dev/null
+++ b/compiler/rustc_hir/src/arena.rs
@@ -0,0 +1,55 @@
+/// This higher-order macro declares a list of types which can be allocated by `Arena`.
+///
+/// Specifying the `decode` modifier will add decode impls for `&T` and `&[T]`,
+/// where `T` is the type listed. These impls will appear in the implement_ty_decoder! macro.
+#[macro_export]
+macro_rules! arena_types {
+ ($macro:path) => (
+ $macro!([
+ // HIR types
+ [] hir_krate: rustc_hir::Crate<'tcx>,
+ [] arm: rustc_hir::Arm<'tcx>,
+ [] asm_operand: (rustc_hir::InlineAsmOperand<'tcx>, rustc_span::Span),
+ [] asm_template: rustc_ast::InlineAsmTemplatePiece,
+ [] attribute: rustc_ast::Attribute,
+ [] closure: rustc_hir::Closure<'tcx>,
+ [] block: rustc_hir::Block<'tcx>,
+ [] bare_fn_ty: rustc_hir::BareFnTy<'tcx>,
+ [] body: rustc_hir::Body<'tcx>,
+ [] generics: rustc_hir::Generics<'tcx>,
+ [] generic_arg: rustc_hir::GenericArg<'tcx>,
+ [] generic_args: rustc_hir::GenericArgs<'tcx>,
+ [] generic_bound: rustc_hir::GenericBound<'tcx>,
+ [] generic_param: rustc_hir::GenericParam<'tcx>,
+ [] expr: rustc_hir::Expr<'tcx>,
+ [] impl_: rustc_hir::Impl<'tcx>,
+ [] let_expr: rustc_hir::Let<'tcx>,
+ [] expr_field: rustc_hir::ExprField<'tcx>,
+ [] pat_field: rustc_hir::PatField<'tcx>,
+ [] fn_decl: rustc_hir::FnDecl<'tcx>,
+ [] foreign_item: rustc_hir::ForeignItem<'tcx>,
+ [] foreign_item_ref: rustc_hir::ForeignItemRef,
+ [] impl_item: rustc_hir::ImplItem<'tcx>,
+ [] impl_item_ref: rustc_hir::ImplItemRef,
+ [] item: rustc_hir::Item<'tcx>,
+ [] inline_asm: rustc_hir::InlineAsm<'tcx>,
+ [] local: rustc_hir::Local<'tcx>,
+ [] mod_: rustc_hir::Mod<'tcx>,
+ [] owner_info: rustc_hir::OwnerInfo<'tcx>,
+ [] param: rustc_hir::Param<'tcx>,
+ [] pat: rustc_hir::Pat<'tcx>,
+ [] path: rustc_hir::Path<'tcx>,
+ [] path_segment: rustc_hir::PathSegment<'tcx>,
+ [] poly_trait_ref: rustc_hir::PolyTraitRef<'tcx>,
+ [] qpath: rustc_hir::QPath<'tcx>,
+ [] stmt: rustc_hir::Stmt<'tcx>,
+ [] field_def: rustc_hir::FieldDef<'tcx>,
+ [] trait_item: rustc_hir::TraitItem<'tcx>,
+ [] trait_item_ref: rustc_hir::TraitItemRef,
+ [] ty: rustc_hir::Ty<'tcx>,
+ [] type_binding: rustc_hir::TypeBinding<'tcx>,
+ [] variant: rustc_hir::Variant<'tcx>,
+ [] where_predicate: rustc_hir::WherePredicate<'tcx>,
+ ]);
+ )
+}
diff --git a/compiler/rustc_hir/src/def.rs b/compiler/rustc_hir/src/def.rs
new file mode 100644
index 000000000..be5b7eccb
--- /dev/null
+++ b/compiler/rustc_hir/src/def.rs
@@ -0,0 +1,749 @@
+use crate::hir;
+
+use rustc_ast as ast;
+use rustc_ast::NodeId;
+use rustc_macros::HashStable_Generic;
+use rustc_span::def_id::{DefId, LocalDefId};
+use rustc_span::hygiene::MacroKind;
+use rustc_span::Symbol;
+
+use std::array::IntoIter;
+use std::fmt::Debug;
+
+/// Encodes if a `DefKind::Ctor` is the constructor of an enum variant or a struct.
+#[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug)]
+#[derive(HashStable_Generic)]
+pub enum CtorOf {
+ /// This `DefKind::Ctor` is a synthesized constructor of a tuple or unit struct.
+ Struct,
+ /// This `DefKind::Ctor` is a synthesized constructor of a tuple or unit variant.
+ Variant,
+}
+
+/// What kind of constructor something is.
+#[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug)]
+#[derive(HashStable_Generic)]
+pub enum CtorKind {
+ /// Constructor function automatically created by a tuple struct/variant.
+ Fn,
+ /// Constructor constant automatically created by a unit struct/variant.
+ Const,
+ /// Unusable name in value namespace created by a struct variant.
+ Fictive,
+}
+
+/// An attribute that is not a macro; e.g., `#[inline]` or `#[rustfmt::skip]`.
+#[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug)]
+#[derive(HashStable_Generic)]
+pub enum NonMacroAttrKind {
+ /// Single-segment attribute defined by the language (`#[inline]`)
+ Builtin(Symbol),
+ /// Multi-segment custom attribute living in a "tool module" (`#[rustfmt::skip]`).
+ Tool,
+ /// Single-segment custom attribute registered by a derive macro (`#[serde(default)]`).
+ DeriveHelper,
+ /// Single-segment custom attribute registered by a derive macro
+ /// but used before that derive macro was expanded (deprecated).
+ DeriveHelperCompat,
+ /// Single-segment custom attribute registered with `#[register_attr]`.
+ Registered,
+}
+
+/// What kind of definition something is; e.g., `mod` vs `struct`.
+#[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug)]
+#[derive(HashStable_Generic)]
+pub enum DefKind {
+ // Type namespace
+ Mod,
+ /// Refers to the struct itself, [`DefKind::Ctor`] refers to its constructor if it exists.
+ Struct,
+ Union,
+ Enum,
+ /// Refers to the variant itself, [`DefKind::Ctor`] refers to its constructor if it exists.
+ Variant,
+ Trait,
+ /// Type alias: `type Foo = Bar;`
+ TyAlias,
+ /// Type from an `extern` block.
+ ForeignTy,
+ /// Trait alias: `trait IntIterator = Iterator<Item = i32>;`
+ TraitAlias,
+ /// Associated type: `trait MyTrait { type Assoc; }`
+ AssocTy,
+ /// Type parameter: the `T` in `struct Vec<T> { ... }`
+ TyParam,
+
+ // Value namespace
+ Fn,
+ Const,
+ /// Constant generic parameter: `struct Foo<const N: usize> { ... }`
+ ConstParam,
+ Static(ast::Mutability),
+ /// Refers to the struct or enum variant's constructor.
+ ///
+ /// The reason `Ctor` exists in addition to [`DefKind::Struct`] and
+ /// [`DefKind::Variant`] is because structs and enum variants exist
+ /// in the *type* namespace, whereas struct and enum variant *constructors*
+ /// exist in the *value* namespace.
+ ///
+ /// You may wonder why enum variants exist in the type namespace as opposed
+ /// to the value namespace. Check out [RFC 2593] for intuition on why that is.
+ ///
+ /// [RFC 2593]: https://github.com/rust-lang/rfcs/pull/2593
+ Ctor(CtorOf, CtorKind),
+ /// Associated function: `impl MyStruct { fn associated() {} }`
+ /// or `trait Foo { fn associated() {} }`
+ AssocFn,
+ /// Associated constant: `trait MyTrait { const ASSOC: usize; }`
+ AssocConst,
+
+ // Macro namespace
+ Macro(MacroKind),
+
+ // Not namespaced (or they are, but we don't treat them so)
+ ExternCrate,
+ Use,
+ /// An `extern` block.
+ ForeignMod,
+ /// Anonymous constant, e.g. the `1 + 2` in `[u8; 1 + 2]`
+ AnonConst,
+ /// An inline constant, e.g. `const { 1 + 2 }`
+ InlineConst,
+ /// Opaque type, aka `impl Trait`.
+ OpaqueTy,
+ Field,
+ /// Lifetime parameter: the `'a` in `struct Foo<'a> { ... }`
+ LifetimeParam,
+ /// A use of `global_asm!`.
+ GlobalAsm,
+ Impl,
+ Closure,
+ Generator,
+}
+
+impl DefKind {
+ pub fn descr(self, def_id: DefId) -> &'static str {
+ match self {
+ DefKind::Fn => "function",
+ DefKind::Mod if def_id.is_crate_root() && !def_id.is_local() => "crate",
+ DefKind::Mod => "module",
+ DefKind::Static(..) => "static",
+ DefKind::Enum => "enum",
+ DefKind::Variant => "variant",
+ DefKind::Ctor(CtorOf::Variant, CtorKind::Fn) => "tuple variant",
+ DefKind::Ctor(CtorOf::Variant, CtorKind::Const) => "unit variant",
+ DefKind::Ctor(CtorOf::Variant, CtorKind::Fictive) => "struct variant",
+ DefKind::Struct => "struct",
+ DefKind::Ctor(CtorOf::Struct, CtorKind::Fn) => "tuple struct",
+ DefKind::Ctor(CtorOf::Struct, CtorKind::Const) => "unit struct",
+ DefKind::Ctor(CtorOf::Struct, CtorKind::Fictive) => {
+ panic!("impossible struct constructor")
+ }
+ DefKind::OpaqueTy => "opaque type",
+ DefKind::TyAlias => "type alias",
+ DefKind::TraitAlias => "trait alias",
+ DefKind::AssocTy => "associated type",
+ DefKind::Union => "union",
+ DefKind::Trait => "trait",
+ DefKind::ForeignTy => "foreign type",
+ DefKind::AssocFn => "associated function",
+ DefKind::Const => "constant",
+ DefKind::AssocConst => "associated constant",
+ DefKind::TyParam => "type parameter",
+ DefKind::ConstParam => "const parameter",
+ DefKind::Macro(macro_kind) => macro_kind.descr(),
+ DefKind::LifetimeParam => "lifetime parameter",
+ DefKind::Use => "import",
+ DefKind::ForeignMod => "foreign module",
+ DefKind::AnonConst => "constant expression",
+ DefKind::InlineConst => "inline constant",
+ DefKind::Field => "field",
+ DefKind::Impl => "implementation",
+ DefKind::Closure => "closure",
+ DefKind::Generator => "generator",
+ DefKind::ExternCrate => "extern crate",
+ DefKind::GlobalAsm => "global assembly block",
+ }
+ }
+
+ /// Gets an English article for the definition.
+ pub fn article(&self) -> &'static str {
+ match *self {
+ DefKind::AssocTy
+ | DefKind::AssocConst
+ | DefKind::AssocFn
+ | DefKind::Enum
+ | DefKind::OpaqueTy
+ | DefKind::Impl
+ | DefKind::Use
+ | DefKind::InlineConst
+ | DefKind::ExternCrate => "an",
+ DefKind::Macro(macro_kind) => macro_kind.article(),
+ _ => "a",
+ }
+ }
+
+ pub fn ns(&self) -> Option<Namespace> {
+ match self {
+ DefKind::Mod
+ | DefKind::Struct
+ | DefKind::Union
+ | DefKind::Enum
+ | DefKind::Variant
+ | DefKind::Trait
+ | DefKind::OpaqueTy
+ | DefKind::TyAlias
+ | DefKind::ForeignTy
+ | DefKind::TraitAlias
+ | DefKind::AssocTy
+ | DefKind::TyParam => Some(Namespace::TypeNS),
+
+ DefKind::Fn
+ | DefKind::Const
+ | DefKind::ConstParam
+ | DefKind::Static(..)
+ | DefKind::Ctor(..)
+ | DefKind::AssocFn
+ | DefKind::AssocConst => Some(Namespace::ValueNS),
+
+ DefKind::Macro(..) => Some(Namespace::MacroNS),
+
+ // Not namespaced.
+ DefKind::AnonConst
+ | DefKind::InlineConst
+ | DefKind::Field
+ | DefKind::LifetimeParam
+ | DefKind::ExternCrate
+ | DefKind::Closure
+ | DefKind::Generator
+ | DefKind::Use
+ | DefKind::ForeignMod
+ | DefKind::GlobalAsm
+ | DefKind::Impl => None,
+ }
+ }
+
+ #[inline]
+ pub fn is_fn_like(self) -> bool {
+ match self {
+ DefKind::Fn | DefKind::AssocFn | DefKind::Closure | DefKind::Generator => true,
+ _ => false,
+ }
+ }
+
+ /// Whether `query get_codegen_attrs` should be used with this definition.
+ pub fn has_codegen_attrs(self) -> bool {
+ match self {
+ DefKind::Fn
+ | DefKind::AssocFn
+ | DefKind::Ctor(..)
+ | DefKind::Closure
+ | DefKind::Generator
+ | DefKind::Static(_) => true,
+ DefKind::Mod
+ | DefKind::Struct
+ | DefKind::Union
+ | DefKind::Enum
+ | DefKind::Variant
+ | DefKind::Trait
+ | DefKind::TyAlias
+ | DefKind::ForeignTy
+ | DefKind::TraitAlias
+ | DefKind::AssocTy
+ | DefKind::Const
+ | DefKind::AssocConst
+ | DefKind::Macro(..)
+ | DefKind::Use
+ | DefKind::ForeignMod
+ | DefKind::OpaqueTy
+ | DefKind::Impl
+ | DefKind::Field
+ | DefKind::TyParam
+ | DefKind::ConstParam
+ | DefKind::LifetimeParam
+ | DefKind::AnonConst
+ | DefKind::InlineConst
+ | DefKind::GlobalAsm
+ | DefKind::ExternCrate => false,
+ }
+ }
+}
+
+/// The resolution of a path or export.
+///
+/// For every path or identifier in Rust, the compiler must determine
+/// what the path refers to. This process is called name resolution,
+/// and `Res` is the primary result of name resolution.
+///
+/// For example, everything prefixed with `/* Res */` in this example has
+/// an associated `Res`:
+///
+/// ```
+/// fn str_to_string(s: & /* Res */ str) -> /* Res */ String {
+/// /* Res */ String::from(/* Res */ s)
+/// }
+///
+/// /* Res */ str_to_string("hello");
+/// ```
+///
+/// The associated `Res`s will be:
+///
+/// - `str` will resolve to [`Res::PrimTy`];
+/// - `String` will resolve to [`Res::Def`], and the `Res` will include the [`DefId`]
+/// for `String` as defined in the standard library;
+/// - `String::from` will also resolve to [`Res::Def`], with the [`DefId`]
+/// pointing to `String::from`;
+/// - `s` will resolve to [`Res::Local`];
+/// - the call to `str_to_string` will resolve to [`Res::Def`], with the [`DefId`]
+/// pointing to the definition of `str_to_string` in the current crate.
+//
+#[derive(Clone, Copy, PartialEq, Eq, Encodable, Decodable, Hash, Debug)]
+#[derive(HashStable_Generic)]
+pub enum Res<Id = hir::HirId> {
+ /// Definition having a unique ID (`DefId`), corresponds to something defined in user code.
+ ///
+ /// **Not bound to a specific namespace.**
+ Def(DefKind, DefId),
+
+ // Type namespace
+ /// A primitive type such as `i32` or `str`.
+ ///
+ /// **Belongs to the type namespace.**
+ PrimTy(hir::PrimTy),
+ /// The `Self` type, optionally with the [`DefId`] of the trait it belongs to and
+ /// optionally with the [`DefId`] of the item introducing the `Self` type alias.
+ ///
+ /// **Belongs to the type namespace.**
+ ///
+ /// Examples:
+ /// ```
+ /// struct Bar(Box<Self>);
+ /// // `Res::SelfTy { trait_: None, alias_of: Some(Bar) }`
+ ///
+ /// trait Foo {
+ /// fn foo() -> Box<Self>;
+ /// // `Res::SelfTy { trait_: Some(Foo), alias_of: None }`
+ /// }
+ ///
+ /// impl Bar {
+ /// fn blah() {
+ /// let _: Self;
+ /// // `Res::SelfTy { trait_: None, alias_of: Some(::{impl#0}) }`
+ /// }
+ /// }
+ ///
+ /// impl Foo for Bar {
+ /// fn foo() -> Box<Self> {
+ /// // `Res::SelfTy { trait_: Some(Foo), alias_of: Some(::{impl#1}) }`
+ /// let _: Self;
+ /// // `Res::SelfTy { trait_: Some(Foo), alias_of: Some(::{impl#1}) }`
+ ///
+ /// todo!()
+ /// }
+ /// }
+ /// ```
+ ///
+ /// *See also [`Res::SelfCtor`].*
+ ///
+ /// -----
+ ///
+ /// HACK(min_const_generics): self types also have an optional requirement to **not** mention
+ /// any generic parameters to allow the following with `min_const_generics`:
+ /// ```
+ /// # struct Foo;
+ /// impl Foo { fn test() -> [u8; std::mem::size_of::<Self>()] { todo!() } }
+ ///
+ /// struct Bar([u8; baz::<Self>()]);
+ /// const fn baz<T>() -> usize { 10 }
+ /// ```
+ /// We do however allow `Self` in repeat expression even if it is generic to not break code
+ /// which already works on stable while causing the `const_evaluatable_unchecked` future compat lint:
+ /// ```
+ /// fn foo<T>() {
+ /// let _bar = [1_u8; std::mem::size_of::<*mut T>()];
+ /// }
+ /// ```
+ // FIXME(generic_const_exprs): Remove this bodge once that feature is stable.
+ SelfTy {
+ /// The trait this `Self` is a generic arg for.
+ trait_: Option<DefId>,
+ /// The item introducing the `Self` type alias. Can be used in the `type_of` query
+ /// to get the underlying type. Additionally whether the `Self` type is disallowed
+ /// from mentioning generics (i.e. when used in an anonymous constant).
+ alias_to: Option<(DefId, bool)>,
+ },
+ /// A tool attribute module; e.g., the `rustfmt` in `#[rustfmt::skip]`.
+ ///
+ /// **Belongs to the type namespace.**
+ ToolMod,
+
+ // Value namespace
+ /// The `Self` constructor, along with the [`DefId`]
+ /// of the impl it is associated with.
+ ///
+ /// **Belongs to the value namespace.**
+ ///
+ /// *See also [`Res::SelfTy`].*
+ SelfCtor(DefId),
+ /// A local variable or function parameter.
+ ///
+ /// **Belongs to the value namespace.**
+ Local(Id),
+
+ // Macro namespace
+ /// An attribute that is *not* implemented via macro.
+ /// E.g., `#[inline]` and `#[rustfmt::skip]`, which are essentially directives,
+ /// as opposed to `#[test]`, which is a builtin macro.
+ ///
+ /// **Belongs to the macro namespace.**
+ NonMacroAttr(NonMacroAttrKind), // e.g., `#[inline]` or `#[rustfmt::skip]`
+
+ // All namespaces
+ /// Name resolution failed. We use a dummy `Res` variant so later phases
+ /// of the compiler won't crash and can instead report more errors.
+ ///
+ /// **Not bound to a specific namespace.**
+ Err,
+}
+
+/// The result of resolving a path before lowering to HIR,
+/// with "module" segments resolved and associated item
+/// segments deferred to type checking.
+/// `base_res` is the resolution of the resolved part of the
+/// path, `unresolved_segments` is the number of unresolved
+/// segments.
+///
+/// ```text
+/// module::Type::AssocX::AssocY::MethodOrAssocType
+/// ^~~~~~~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+/// base_res unresolved_segments = 3
+///
+/// <T as Trait>::AssocX::AssocY::MethodOrAssocType
+/// ^~~~~~~~~~~~~~ ^~~~~~~~~~~~~~~~~~~~~~~~~
+/// base_res unresolved_segments = 2
+/// ```
+#[derive(Copy, Clone, Debug)]
+pub struct PartialRes {
+ base_res: Res<NodeId>,
+ unresolved_segments: usize,
+}
+
+impl PartialRes {
+ #[inline]
+ pub fn new(base_res: Res<NodeId>) -> Self {
+ PartialRes { base_res, unresolved_segments: 0 }
+ }
+
+ #[inline]
+ pub fn with_unresolved_segments(base_res: Res<NodeId>, mut unresolved_segments: usize) -> Self {
+ if base_res == Res::Err {
+ unresolved_segments = 0
+ }
+ PartialRes { base_res, unresolved_segments }
+ }
+
+ #[inline]
+ pub fn base_res(&self) -> Res<NodeId> {
+ self.base_res
+ }
+
+ #[inline]
+ pub fn unresolved_segments(&self) -> usize {
+ self.unresolved_segments
+ }
+}
+
+/// Different kinds of symbols can coexist even if they share the same textual name.
+/// Therefore, they each have a separate universe (known as a "namespace").
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
+pub enum Namespace {
+ /// The type namespace includes `struct`s, `enum`s, `union`s, `trait`s, and `mod`s
+ /// (and, by extension, crates).
+ ///
+ /// Note that the type namespace includes other items; this is not an
+ /// exhaustive list.
+ TypeNS,
+ /// The value namespace includes `fn`s, `const`s, `static`s, and local variables (including function arguments).
+ ValueNS,
+ /// The macro namespace includes `macro_rules!` macros, declarative `macro`s,
+ /// procedural macros, attribute macros, `derive` macros, and non-macro attributes
+ /// like `#[inline]` and `#[rustfmt::skip]`.
+ MacroNS,
+}
+
+impl Namespace {
+ /// The English description of the namespace.
+ pub fn descr(self) -> &'static str {
+ match self {
+ Self::TypeNS => "type",
+ Self::ValueNS => "value",
+ Self::MacroNS => "macro",
+ }
+ }
+}
+
+/// Just a helper ‒ separate structure for each namespace.
+#[derive(Copy, Clone, Default, Debug)]
+pub struct PerNS<T> {
+ pub value_ns: T,
+ pub type_ns: T,
+ pub macro_ns: T,
+}
+
+impl<T> PerNS<T> {
+ pub fn map<U, F: FnMut(T) -> U>(self, mut f: F) -> PerNS<U> {
+ PerNS { value_ns: f(self.value_ns), type_ns: f(self.type_ns), macro_ns: f(self.macro_ns) }
+ }
+
+ pub fn into_iter(self) -> IntoIter<T, 3> {
+ [self.value_ns, self.type_ns, self.macro_ns].into_iter()
+ }
+
+ pub fn iter(&self) -> IntoIter<&T, 3> {
+ [&self.value_ns, &self.type_ns, &self.macro_ns].into_iter()
+ }
+}
+
+impl<T> ::std::ops::Index<Namespace> for PerNS<T> {
+ type Output = T;
+
+ fn index(&self, ns: Namespace) -> &T {
+ match ns {
+ Namespace::ValueNS => &self.value_ns,
+ Namespace::TypeNS => &self.type_ns,
+ Namespace::MacroNS => &self.macro_ns,
+ }
+ }
+}
+
+impl<T> ::std::ops::IndexMut<Namespace> for PerNS<T> {
+ fn index_mut(&mut self, ns: Namespace) -> &mut T {
+ match ns {
+ Namespace::ValueNS => &mut self.value_ns,
+ Namespace::TypeNS => &mut self.type_ns,
+ Namespace::MacroNS => &mut self.macro_ns,
+ }
+ }
+}
+
+impl<T> PerNS<Option<T>> {
+ /// Returns `true` if all the items in this collection are `None`.
+ pub fn is_empty(&self) -> bool {
+ self.type_ns.is_none() && self.value_ns.is_none() && self.macro_ns.is_none()
+ }
+
+ /// Returns an iterator over the items which are `Some`.
+ pub fn present_items(self) -> impl Iterator<Item = T> {
+ [self.type_ns, self.value_ns, self.macro_ns].into_iter().flatten()
+ }
+}
+
+impl CtorKind {
+ pub fn from_ast(vdata: &ast::VariantData) -> CtorKind {
+ match *vdata {
+ ast::VariantData::Tuple(..) => CtorKind::Fn,
+ ast::VariantData::Unit(..) => CtorKind::Const,
+ ast::VariantData::Struct(..) => CtorKind::Fictive,
+ }
+ }
+
+ pub fn from_hir(vdata: &hir::VariantData<'_>) -> CtorKind {
+ match *vdata {
+ hir::VariantData::Tuple(..) => CtorKind::Fn,
+ hir::VariantData::Unit(..) => CtorKind::Const,
+ hir::VariantData::Struct(..) => CtorKind::Fictive,
+ }
+ }
+}
+
+impl NonMacroAttrKind {
+ pub fn descr(self) -> &'static str {
+ match self {
+ NonMacroAttrKind::Builtin(..) => "built-in attribute",
+ NonMacroAttrKind::Tool => "tool attribute",
+ NonMacroAttrKind::DeriveHelper | NonMacroAttrKind::DeriveHelperCompat => {
+ "derive helper attribute"
+ }
+ NonMacroAttrKind::Registered => "explicitly registered attribute",
+ }
+ }
+
+ pub fn article(self) -> &'static str {
+ match self {
+ NonMacroAttrKind::Registered => "an",
+ _ => "a",
+ }
+ }
+
+ /// Users of some attributes cannot mark them as used, so they are considered always used.
+ pub fn is_used(self) -> bool {
+ match self {
+ NonMacroAttrKind::Tool
+ | NonMacroAttrKind::DeriveHelper
+ | NonMacroAttrKind::DeriveHelperCompat => true,
+ NonMacroAttrKind::Builtin(..) | NonMacroAttrKind::Registered => false,
+ }
+ }
+}
+
+impl<Id> Res<Id> {
+ /// Return the `DefId` of this `Def` if it has an ID, else panic.
+ pub fn def_id(&self) -> DefId
+ where
+ Id: Debug,
+ {
+ self.opt_def_id()
+ .unwrap_or_else(|| panic!("attempted .def_id() on invalid res: {:?}", self))
+ }
+
+ /// Return `Some(..)` with the `DefId` of this `Res` if it has a ID, else `None`.
+ pub fn opt_def_id(&self) -> Option<DefId> {
+ match *self {
+ Res::Def(_, id) => Some(id),
+
+ Res::Local(..)
+ | Res::PrimTy(..)
+ | Res::SelfTy { .. }
+ | Res::SelfCtor(..)
+ | Res::ToolMod
+ | Res::NonMacroAttr(..)
+ | Res::Err => None,
+ }
+ }
+
+ /// Return the `DefId` of this `Res` if it represents a module.
+ pub fn mod_def_id(&self) -> Option<DefId> {
+ match *self {
+ Res::Def(DefKind::Mod, id) => Some(id),
+ _ => None,
+ }
+ }
+
+ /// A human readable name for the res kind ("function", "module", etc.).
+ pub fn descr(&self) -> &'static str {
+ match *self {
+ Res::Def(kind, def_id) => kind.descr(def_id),
+ Res::SelfCtor(..) => "self constructor",
+ Res::PrimTy(..) => "builtin type",
+ Res::Local(..) => "local variable",
+ Res::SelfTy { .. } => "self type",
+ Res::ToolMod => "tool module",
+ Res::NonMacroAttr(attr_kind) => attr_kind.descr(),
+ Res::Err => "unresolved item",
+ }
+ }
+
+ /// Gets an English article for the `Res`.
+ pub fn article(&self) -> &'static str {
+ match *self {
+ Res::Def(kind, _) => kind.article(),
+ Res::NonMacroAttr(kind) => kind.article(),
+ Res::Err => "an",
+ _ => "a",
+ }
+ }
+
+ pub fn map_id<R>(self, mut map: impl FnMut(Id) -> R) -> Res<R> {
+ match self {
+ Res::Def(kind, id) => Res::Def(kind, id),
+ Res::SelfCtor(id) => Res::SelfCtor(id),
+ Res::PrimTy(id) => Res::PrimTy(id),
+ Res::Local(id) => Res::Local(map(id)),
+ Res::SelfTy { trait_, alias_to } => Res::SelfTy { trait_, alias_to },
+ Res::ToolMod => Res::ToolMod,
+ Res::NonMacroAttr(attr_kind) => Res::NonMacroAttr(attr_kind),
+ Res::Err => Res::Err,
+ }
+ }
+
+ pub fn apply_id<R, E>(self, mut map: impl FnMut(Id) -> Result<R, E>) -> Result<Res<R>, E> {
+ Ok(match self {
+ Res::Def(kind, id) => Res::Def(kind, id),
+ Res::SelfCtor(id) => Res::SelfCtor(id),
+ Res::PrimTy(id) => Res::PrimTy(id),
+ Res::Local(id) => Res::Local(map(id)?),
+ Res::SelfTy { trait_, alias_to } => Res::SelfTy { trait_, alias_to },
+ Res::ToolMod => Res::ToolMod,
+ Res::NonMacroAttr(attr_kind) => Res::NonMacroAttr(attr_kind),
+ Res::Err => Res::Err,
+ })
+ }
+
+ #[track_caller]
+ pub fn expect_non_local<OtherId>(self) -> Res<OtherId> {
+ self.map_id(
+ #[track_caller]
+ |_| panic!("unexpected `Res::Local`"),
+ )
+ }
+
+ pub fn macro_kind(self) -> Option<MacroKind> {
+ match self {
+ Res::Def(DefKind::Macro(kind), _) => Some(kind),
+ Res::NonMacroAttr(..) => Some(MacroKind::Attr),
+ _ => None,
+ }
+ }
+
+ /// Returns `None` if this is `Res::Err`
+ pub fn ns(&self) -> Option<Namespace> {
+ match self {
+ Res::Def(kind, ..) => kind.ns(),
+ Res::PrimTy(..) | Res::SelfTy { .. } | Res::ToolMod => Some(Namespace::TypeNS),
+ Res::SelfCtor(..) | Res::Local(..) => Some(Namespace::ValueNS),
+ Res::NonMacroAttr(..) => Some(Namespace::MacroNS),
+ Res::Err => None,
+ }
+ }
+
+ /// Always returns `true` if `self` is `Res::Err`
+ pub fn matches_ns(&self, ns: Namespace) -> bool {
+ self.ns().map_or(true, |actual_ns| actual_ns == ns)
+ }
+
+ /// Returns whether such a resolved path can occur in a tuple struct/variant pattern
+ pub fn expected_in_tuple_struct_pat(&self) -> bool {
+ matches!(self, Res::Def(DefKind::Ctor(_, CtorKind::Fn), _) | Res::SelfCtor(..))
+ }
+
+ /// Returns whether such a resolved path can occur in a unit struct/variant pattern
+ pub fn expected_in_unit_struct_pat(&self) -> bool {
+ matches!(self, Res::Def(DefKind::Ctor(_, CtorKind::Const), _) | Res::SelfCtor(..))
+ }
+}
+
+/// Resolution for a lifetime appearing in a type.
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+pub enum LifetimeRes {
+ /// Successfully linked the lifetime to a generic parameter.
+ Param {
+ /// Id of the generic parameter that introduced it.
+ param: LocalDefId,
+ /// Id of the introducing place. That can be:
+ /// - an item's id, for the item's generic parameters;
+ /// - a TraitRef's ref_id, identifying the `for<...>` binder;
+ /// - a BareFn type's id.
+ ///
+ /// This information is used for impl-trait lifetime captures, to know when to or not to
+ /// capture any given lifetime.
+ binder: NodeId,
+ },
+ /// Created a generic parameter for an anonymous lifetime.
+ Fresh {
+ /// Id of the generic parameter that introduced it.
+ ///
+ /// Creating the associated `LocalDefId` is the responsibility of lowering.
+ param: NodeId,
+ /// Id of the introducing place. See `Param`.
+ binder: NodeId,
+ },
+ /// This variant is used for anonymous lifetimes that we did not resolve during
+ /// late resolution. Those lifetimes will be inferred by typechecking.
+ Infer,
+ /// Explicit `'static` lifetime.
+ Static,
+ /// Resolution failure.
+ Error,
+ /// HACK: This is used to recover the NodeId of an elided lifetime.
+ ElidedAnchor { start: NodeId, end: NodeId },
+}
diff --git a/compiler/rustc_hir/src/def_path_hash_map.rs b/compiler/rustc_hir/src/def_path_hash_map.rs
new file mode 100644
index 000000000..8bfb47af2
--- /dev/null
+++ b/compiler/rustc_hir/src/def_path_hash_map.rs
@@ -0,0 +1,37 @@
+use rustc_data_structures::fingerprint::Fingerprint;
+use rustc_span::def_id::{DefIndex, DefPathHash};
+
+#[derive(Clone, Default)]
+pub struct Config;
+
+impl odht::Config for Config {
+ type Key = DefPathHash;
+ type Value = DefIndex;
+
+ type EncodedKey = [u8; 16];
+ type EncodedValue = [u8; 4];
+
+ type H = odht::UnHashFn;
+
+ #[inline]
+ fn encode_key(k: &DefPathHash) -> [u8; 16] {
+ k.0.to_le_bytes()
+ }
+
+ #[inline]
+ fn encode_value(v: &DefIndex) -> [u8; 4] {
+ v.as_u32().to_le_bytes()
+ }
+
+ #[inline]
+ fn decode_key(k: &[u8; 16]) -> DefPathHash {
+ DefPathHash(Fingerprint::from_le_bytes(*k))
+ }
+
+ #[inline]
+ fn decode_value(v: &[u8; 4]) -> DefIndex {
+ DefIndex::from_u32(u32::from_le_bytes(*v))
+ }
+}
+
+pub type DefPathHashMap = odht::HashTableOwned<Config>;
diff --git a/compiler/rustc_hir/src/definitions.rs b/compiler/rustc_hir/src/definitions.rs
new file mode 100644
index 000000000..c2c551e78
--- /dev/null
+++ b/compiler/rustc_hir/src/definitions.rs
@@ -0,0 +1,440 @@
+//! For each definition, we track the following data. A definition
+//! here is defined somewhat circularly as "something with a `DefId`",
+//! but it generally corresponds to things like structs, enums, etc.
+//! There are also some rather random cases (like const initializer
+//! expressions) that are mostly just leftovers.
+
+pub use crate::def_id::DefPathHash;
+use crate::def_id::{CrateNum, DefIndex, LocalDefId, StableCrateId, CRATE_DEF_INDEX, LOCAL_CRATE};
+use crate::def_path_hash_map::DefPathHashMap;
+
+use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::stable_hasher::StableHasher;
+use rustc_index::vec::IndexVec;
+use rustc_span::symbol::{kw, sym, Symbol};
+
+use std::fmt::{self, Write};
+use std::hash::Hash;
+use tracing::debug;
+
+/// The `DefPathTable` maps `DefIndex`es to `DefKey`s and vice versa.
+/// Internally the `DefPathTable` holds a tree of `DefKey`s, where each `DefKey`
+/// stores the `DefIndex` of its parent.
+/// There is one `DefPathTable` for each crate.
+#[derive(Clone, Default, Debug)]
+pub struct DefPathTable {
+ index_to_key: IndexVec<DefIndex, DefKey>,
+ def_path_hashes: IndexVec<DefIndex, DefPathHash>,
+ def_path_hash_to_index: DefPathHashMap,
+}
+
+impl DefPathTable {
+ fn allocate(&mut self, key: DefKey, def_path_hash: DefPathHash) -> DefIndex {
+ let index = {
+ let index = DefIndex::from(self.index_to_key.len());
+ debug!("DefPathTable::insert() - {:?} <-> {:?}", key, index);
+ self.index_to_key.push(key);
+ index
+ };
+ self.def_path_hashes.push(def_path_hash);
+ debug_assert!(self.def_path_hashes.len() == self.index_to_key.len());
+
+ // Check for hash collisions of DefPathHashes. These should be
+ // exceedingly rare.
+ if let Some(existing) = self.def_path_hash_to_index.insert(&def_path_hash, &index) {
+ let def_path1 = DefPath::make(LOCAL_CRATE, existing, |idx| self.def_key(idx));
+ let def_path2 = DefPath::make(LOCAL_CRATE, index, |idx| self.def_key(idx));
+
+ // Continuing with colliding DefPathHashes can lead to correctness
+ // issues. We must abort compilation.
+ //
+ // The likelihood of such a collision is very small, so actually
+ // running into one could be indicative of a poor hash function
+ // being used.
+ //
+ // See the documentation for DefPathHash for more information.
+ panic!(
+ "found DefPathHash collision between {:?} and {:?}. \
+ Compilation cannot continue.",
+ def_path1, def_path2
+ );
+ }
+
+ // Assert that all DefPathHashes correctly contain the local crate's
+ // StableCrateId
+ #[cfg(debug_assertions)]
+ if let Some(root) = self.def_path_hashes.get(CRATE_DEF_INDEX) {
+ assert!(def_path_hash.stable_crate_id() == root.stable_crate_id());
+ }
+
+ index
+ }
+
+ #[inline(always)]
+ pub fn def_key(&self, index: DefIndex) -> DefKey {
+ self.index_to_key[index]
+ }
+
+ #[inline(always)]
+ pub fn def_path_hash(&self, index: DefIndex) -> DefPathHash {
+ let hash = self.def_path_hashes[index];
+ debug!("def_path_hash({:?}) = {:?}", index, hash);
+ hash
+ }
+
+ pub fn enumerated_keys_and_path_hashes(
+ &self,
+ ) -> impl Iterator<Item = (DefIndex, &DefKey, &DefPathHash)> + ExactSizeIterator + '_ {
+ self.index_to_key
+ .iter_enumerated()
+ .map(move |(index, key)| (index, key, &self.def_path_hashes[index]))
+ }
+}
+
+/// The definition table containing node definitions.
+/// It holds the `DefPathTable` for `LocalDefId`s/`DefPath`s.
+/// It also stores mappings to convert `LocalDefId`s to/from `HirId`s.
+#[derive(Clone, Debug)]
+pub struct Definitions {
+ table: DefPathTable,
+ next_disambiguator: FxHashMap<(LocalDefId, DefPathData), u32>,
+
+ /// The [StableCrateId] of the local crate.
+ stable_crate_id: StableCrateId,
+}
+
+/// A unique identifier that we can use to lookup a definition
+/// precisely. It combines the index of the definition's parent (if
+/// any) with a `DisambiguatedDefPathData`.
+#[derive(Copy, Clone, PartialEq, Debug, Encodable, Decodable)]
+pub struct DefKey {
+ /// The parent path.
+ pub parent: Option<DefIndex>,
+
+ /// The identifier of this node.
+ pub disambiguated_data: DisambiguatedDefPathData,
+}
+
+impl DefKey {
+ pub(crate) fn compute_stable_hash(&self, parent: DefPathHash) -> DefPathHash {
+ let mut hasher = StableHasher::new();
+
+ parent.hash(&mut hasher);
+
+ let DisambiguatedDefPathData { ref data, disambiguator } = self.disambiguated_data;
+
+ std::mem::discriminant(data).hash(&mut hasher);
+ if let Some(name) = data.get_opt_name() {
+ // Get a stable hash by considering the symbol chars rather than
+ // the symbol index.
+ name.as_str().hash(&mut hasher);
+ }
+
+ disambiguator.hash(&mut hasher);
+
+ let local_hash: u64 = hasher.finish();
+
+ // Construct the new DefPathHash, making sure that the `crate_id`
+ // portion of the hash is properly copied from the parent. This way the
+ // `crate_id` part will be recursively propagated from the root to all
+ // DefPathHashes in this DefPathTable.
+ DefPathHash::new(parent.stable_crate_id(), local_hash)
+ }
+
+ #[inline]
+ pub fn get_opt_name(&self) -> Option<Symbol> {
+ self.disambiguated_data.data.get_opt_name()
+ }
+}
+
+/// A pair of `DefPathData` and an integer disambiguator. The integer is
+/// normally `0`, but in the event that there are multiple defs with the
+/// same `parent` and `data`, we use this field to disambiguate
+/// between them. This introduces some artificial ordering dependency
+/// but means that if you have, e.g., two impls for the same type in
+/// the same module, they do get distinct `DefId`s.
+#[derive(Copy, Clone, PartialEq, Debug, Encodable, Decodable)]
+pub struct DisambiguatedDefPathData {
+ pub data: DefPathData,
+ pub disambiguator: u32,
+}
+
+impl DisambiguatedDefPathData {
+ pub fn fmt_maybe_verbose(&self, writer: &mut impl Write, verbose: bool) -> fmt::Result {
+ match self.data.name() {
+ DefPathDataName::Named(name) => {
+ if verbose && self.disambiguator != 0 {
+ write!(writer, "{}#{}", name, self.disambiguator)
+ } else {
+ writer.write_str(name.as_str())
+ }
+ }
+ DefPathDataName::Anon { namespace } => {
+ write!(writer, "{{{}#{}}}", namespace, self.disambiguator)
+ }
+ }
+ }
+}
+
+impl fmt::Display for DisambiguatedDefPathData {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ self.fmt_maybe_verbose(f, true)
+ }
+}
+
+#[derive(Clone, Debug, Encodable, Decodable)]
+pub struct DefPath {
+ /// The path leading from the crate root to the item.
+ pub data: Vec<DisambiguatedDefPathData>,
+
+ /// The crate root this path is relative to.
+ pub krate: CrateNum,
+}
+
+impl DefPath {
+ pub fn make<FN>(krate: CrateNum, start_index: DefIndex, mut get_key: FN) -> DefPath
+ where
+ FN: FnMut(DefIndex) -> DefKey,
+ {
+ let mut data = vec![];
+ let mut index = Some(start_index);
+ loop {
+ debug!("DefPath::make: krate={:?} index={:?}", krate, index);
+ let p = index.unwrap();
+ let key = get_key(p);
+ debug!("DefPath::make: key={:?}", key);
+ match key.disambiguated_data.data {
+ DefPathData::CrateRoot => {
+ assert!(key.parent.is_none());
+ break;
+ }
+ _ => {
+ data.push(key.disambiguated_data);
+ index = key.parent;
+ }
+ }
+ }
+ data.reverse();
+ DefPath { data, krate }
+ }
+
+ /// Returns a string representation of the `DefPath` without
+ /// the crate-prefix. This method is useful if you don't have
+ /// a `TyCtxt` available.
+ pub fn to_string_no_crate_verbose(&self) -> String {
+ let mut s = String::with_capacity(self.data.len() * 16);
+
+ for component in &self.data {
+ write!(s, "::{}", component).unwrap();
+ }
+
+ s
+ }
+
+ /// Returns a filename-friendly string of the `DefPath`, without
+ /// the crate-prefix. This method is useful if you don't have
+ /// a `TyCtxt` available.
+ pub fn to_filename_friendly_no_crate(&self) -> String {
+ let mut s = String::with_capacity(self.data.len() * 16);
+
+ let mut opt_delimiter = None;
+ for component in &self.data {
+ s.extend(opt_delimiter);
+ opt_delimiter = Some('-');
+ write!(s, "{}", component).unwrap();
+ }
+
+ s
+ }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, Encodable, Decodable)]
+pub enum DefPathData {
+ // Root: these should only be used for the root nodes, because
+ // they are treated specially by the `def_path` function.
+ /// The crate root (marker).
+ CrateRoot,
+
+ // Different kinds of items and item-like things:
+ /// An impl.
+ Impl,
+ /// An `extern` block.
+ ForeignMod,
+ /// A `use` item.
+ Use,
+ /// A global asm item.
+ GlobalAsm,
+ /// Something in the type namespace.
+ TypeNs(Symbol),
+ /// Something in the value namespace.
+ ValueNs(Symbol),
+ /// Something in the macro namespace.
+ MacroNs(Symbol),
+ /// Something in the lifetime namespace.
+ LifetimeNs(Symbol),
+ /// A closure expression.
+ ClosureExpr,
+
+ // Subportions of items:
+ /// Implicit constructor for a unit or tuple-like struct or enum variant.
+ Ctor,
+ /// A constant expression (see `{ast,hir}::AnonConst`).
+ AnonConst,
+ /// An `impl Trait` type node.
+ ImplTrait,
+}
+
+impl Definitions {
+ pub fn def_path_table(&self) -> &DefPathTable {
+ &self.table
+ }
+
+ /// Gets the number of definitions.
+ pub fn def_index_count(&self) -> usize {
+ self.table.index_to_key.len()
+ }
+
+ #[inline]
+ pub fn def_key(&self, id: LocalDefId) -> DefKey {
+ self.table.def_key(id.local_def_index)
+ }
+
+ #[inline(always)]
+ pub fn def_path_hash(&self, id: LocalDefId) -> DefPathHash {
+ self.table.def_path_hash(id.local_def_index)
+ }
+
+ /// Returns the path from the crate root to `index`. The root
+ /// nodes are not included in the path (i.e., this will be an
+ /// empty vector for the crate root). For an inlined item, this
+ /// will be the path of the item in the external crate (but the
+ /// path will begin with the path to the external crate).
+ pub fn def_path(&self, id: LocalDefId) -> DefPath {
+ DefPath::make(LOCAL_CRATE, id.local_def_index, |index| {
+ self.def_key(LocalDefId { local_def_index: index })
+ })
+ }
+
+ /// Adds a root definition (no parent) and a few other reserved definitions.
+ pub fn new(stable_crate_id: StableCrateId) -> Definitions {
+ let key = DefKey {
+ parent: None,
+ disambiguated_data: DisambiguatedDefPathData {
+ data: DefPathData::CrateRoot,
+ disambiguator: 0,
+ },
+ };
+
+ let parent_hash = DefPathHash::new(stable_crate_id, 0);
+ let def_path_hash = key.compute_stable_hash(parent_hash);
+
+ // Create the root definition.
+ let mut table = DefPathTable::default();
+ let root = LocalDefId { local_def_index: table.allocate(key, def_path_hash) };
+ assert_eq!(root.local_def_index, CRATE_DEF_INDEX);
+
+ Definitions { table, next_disambiguator: Default::default(), stable_crate_id }
+ }
+
+ /// Adds a definition with a parent definition.
+ pub fn create_def(&mut self, parent: LocalDefId, data: DefPathData) -> LocalDefId {
+ // We can't use `Debug` implementation for `LocalDefId` here, since it tries to acquire a
+ // reference to `Definitions` and we're already holding a mutable reference.
+ debug!(
+ "create_def(parent={}, data={data:?})",
+ self.def_path(parent).to_string_no_crate_verbose(),
+ );
+
+ // The root node must be created with `create_root_def()`.
+ assert!(data != DefPathData::CrateRoot);
+
+ // Find the next free disambiguator for this key.
+ let disambiguator = {
+ let next_disamb = self.next_disambiguator.entry((parent, data)).or_insert(0);
+ let disambiguator = *next_disamb;
+ *next_disamb = next_disamb.checked_add(1).expect("disambiguator overflow");
+ disambiguator
+ };
+ let key = DefKey {
+ parent: Some(parent.local_def_index),
+ disambiguated_data: DisambiguatedDefPathData { data, disambiguator },
+ };
+
+ let parent_hash = self.table.def_path_hash(parent.local_def_index);
+ let def_path_hash = key.compute_stable_hash(parent_hash);
+
+ debug!("create_def: after disambiguation, key = {:?}", key);
+
+ // Create the definition.
+ LocalDefId { local_def_index: self.table.allocate(key, def_path_hash) }
+ }
+
+ pub fn iter_local_def_id(&self) -> impl Iterator<Item = LocalDefId> + '_ {
+ self.table.def_path_hashes.indices().map(|local_def_index| LocalDefId { local_def_index })
+ }
+
+ #[inline(always)]
+ pub fn local_def_path_hash_to_def_id(
+ &self,
+ hash: DefPathHash,
+ err: &mut dyn FnMut() -> !,
+ ) -> LocalDefId {
+ debug_assert!(hash.stable_crate_id() == self.stable_crate_id);
+ self.table
+ .def_path_hash_to_index
+ .get(&hash)
+ .map(|local_def_index| LocalDefId { local_def_index })
+ .unwrap_or_else(|| err())
+ }
+
+ pub fn def_path_hash_to_def_index_map(&self) -> &DefPathHashMap {
+ &self.table.def_path_hash_to_index
+ }
+}
+
+#[derive(Copy, Clone, PartialEq, Debug)]
+pub enum DefPathDataName {
+ Named(Symbol),
+ Anon { namespace: Symbol },
+}
+
+impl DefPathData {
+ pub fn get_opt_name(&self) -> Option<Symbol> {
+ use self::DefPathData::*;
+ match *self {
+ TypeNs(name) | ValueNs(name) | MacroNs(name) | LifetimeNs(name) => Some(name),
+
+ Impl | ForeignMod | CrateRoot | Use | GlobalAsm | ClosureExpr | Ctor | AnonConst
+ | ImplTrait => None,
+ }
+ }
+
+ pub fn name(&self) -> DefPathDataName {
+ use self::DefPathData::*;
+ match *self {
+ TypeNs(name) | ValueNs(name) | MacroNs(name) | LifetimeNs(name) => {
+ DefPathDataName::Named(name)
+ }
+ // Note that this does not show up in user print-outs.
+ CrateRoot => DefPathDataName::Anon { namespace: kw::Crate },
+ Impl => DefPathDataName::Anon { namespace: kw::Impl },
+ ForeignMod => DefPathDataName::Anon { namespace: kw::Extern },
+ Use => DefPathDataName::Anon { namespace: kw::Use },
+ GlobalAsm => DefPathDataName::Anon { namespace: sym::global_asm },
+ ClosureExpr => DefPathDataName::Anon { namespace: sym::closure },
+ Ctor => DefPathDataName::Anon { namespace: sym::constructor },
+ AnonConst => DefPathDataName::Anon { namespace: sym::constant },
+ ImplTrait => DefPathDataName::Anon { namespace: sym::opaque },
+ }
+ }
+}
+
+impl fmt::Display for DefPathData {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ match self.name() {
+ DefPathDataName::Named(name) => f.write_str(name.as_str()),
+ // FIXME(#70334): this will generate legacy {{closure}}, {{impl}}, etc
+ DefPathDataName::Anon { namespace } => write!(f, "{{{{{}}}}}", namespace),
+ }
+ }
+}
diff --git a/compiler/rustc_hir/src/diagnostic_items.rs b/compiler/rustc_hir/src/diagnostic_items.rs
new file mode 100644
index 000000000..243014b00
--- /dev/null
+++ b/compiler/rustc_hir/src/diagnostic_items.rs
@@ -0,0 +1,17 @@
+use crate::def_id::DefId;
+use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_span::Symbol;
+
+#[derive(Debug, Default)]
+pub struct DiagnosticItems {
+ pub id_to_name: FxHashMap<DefId, Symbol>,
+ pub name_to_id: FxHashMap<Symbol, DefId>,
+}
+
+impl<CTX: crate::HashStableContext> HashStable<CTX> for DiagnosticItems {
+ #[inline]
+ fn hash_stable(&self, ctx: &mut CTX, hasher: &mut StableHasher) {
+ self.name_to_id.hash_stable(ctx, hasher);
+ }
+}
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
new file mode 100644
index 000000000..617433a98
--- /dev/null
+++ b/compiler/rustc_hir/src/hir.rs
@@ -0,0 +1,3506 @@
+use crate::def::{CtorKind, DefKind, Res};
+use crate::def_id::DefId;
+pub(crate) use crate::hir_id::{HirId, ItemLocalId};
+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::{BorrowKind, ImplPolarity, IsAuto};
+pub use rustc_ast::{CaptureBy, Movability, Mutability};
+use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
+use rustc_data_structures::fingerprint::Fingerprint;
+use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::sorted_map::SortedMap;
+use rustc_error_messages::MultiSpan;
+use rustc_index::vec::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::{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, Encodable, HashStable_Generic)]
+pub struct Lifetime {
+ pub hir_id: HirId,
+ pub span: Span,
+
+ /// Either "`'a`", referring to a named lifetime definition,
+ /// or "``" (i.e., `kw::Empty`), for elision placeholders.
+ ///
+ /// HIR lowering inserts these placeholders in type paths that
+ /// refer to type definitions needing lifetime parameters,
+ /// `&T` and `&mut T`, and trait objects without `... + 'a`.
+ pub name: LifetimeName,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Encodable, Hash, Copy)]
+#[derive(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),
+ }
+ }
+
+ pub fn normalize_to_macros_2_0(&self) -> ParamName {
+ match *self {
+ ParamName::Plain(ident) => ParamName::Plain(ident.normalize_to_macros_2_0()),
+ param_name => param_name,
+ }
+ }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Encodable, Hash, Copy)]
+#[derive(HashStable_Generic)]
+pub enum LifetimeName {
+ /// User-given names or fresh (synthetic) names.
+ Param(LocalDefId, ParamName),
+
+ /// 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 {
+ pub fn ident(&self) -> Ident {
+ match *self {
+ LifetimeName::ImplicitObjectLifetimeDefault | LifetimeName::Error => Ident::empty(),
+ LifetimeName::Infer => Ident::with_dummy_span(kw::UnderscoreLifetime),
+ LifetimeName::Static => Ident::with_dummy_span(kw::StaticLifetime),
+ LifetimeName::Param(_, param_name) => param_name.ident(),
+ }
+ }
+
+ pub fn is_anonymous(&self) -> bool {
+ match *self {
+ LifetimeName::ImplicitObjectLifetimeDefault
+ | LifetimeName::Infer
+ | LifetimeName::Param(_, ParamName::Fresh)
+ | LifetimeName::Error => true,
+ LifetimeName::Static | LifetimeName::Param(..) => false,
+ }
+ }
+
+ pub 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,
+ }
+ }
+
+ fn is_static(&self) -> bool {
+ self == &LifetimeName::Static
+ }
+
+ pub fn normalize_to_macros_2_0(&self) -> LifetimeName {
+ match *self {
+ LifetimeName::Param(def_id, param_name) => {
+ LifetimeName::Param(def_id, param_name.normalize_to_macros_2_0())
+ }
+ lifetime_name => lifetime_name,
+ }
+ }
+}
+
+impl fmt::Display for Lifetime {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ self.name.ident().fmt(f)
+ }
+}
+
+impl Lifetime {
+ pub fn is_elided(&self) -> bool {
+ self.name.is_elided()
+ }
+
+ pub fn is_static(&self) -> bool {
+ self.name.is_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, HashStable_Generic)]
+pub struct Path<'hir> {
+ pub span: Span,
+ /// The resolution for the path.
+ pub res: Res,
+ /// The segments in the path: the things separated by `::`.
+ pub segments: &'hir [PathSegment<'hir>],
+}
+
+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, HashStable_Generic)]
+pub struct PathSegment<'hir> {
+ /// The identifier portion of this path segment.
+ pub ident: Ident,
+ // `id` and `res` are optional. We currently only use these in save-analysis,
+ // any path segments without these will not have save-analysis info and
+ // therefore will not have 'jump to def' in IDEs, but otherwise will not be
+ // affected. (In general, we don't bother to get the defs for synthesized
+ // segments, only for segments which have come from the AST).
+ pub hir_id: Option<HirId>,
+ pub res: Option<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 from_ident(ident: Ident) -> PathSegment<'hir> {
+ PathSegment { ident, hir_id: None, res: None, infer_args: true, args: None }
+ }
+
+ pub fn invalid() -> Self {
+ Self::from_ident(Ident::empty())
+ }
+
+ pub fn args(&self) -> &GenericArgs<'hir> {
+ if let Some(ref args) = self.args {
+ args
+ } else {
+ const DUMMY: &GenericArgs<'_> = &GenericArgs::none();
+ DUMMY
+ }
+ }
+}
+
+#[derive(Encodable, Debug, HashStable_Generic)]
+pub struct ConstArg {
+ pub value: AnonConst,
+ pub span: Span,
+}
+
+#[derive(Encodable, 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, HashStable_Generic)]
+pub enum GenericArg<'hir> {
+ Lifetime(Lifetime),
+ Type(Ty<'hir>),
+ Const(ConstArg),
+ Infer(InferArg),
+}
+
+impl GenericArg<'_> {
+ pub fn span(&self) -> Span {
+ match self {
+ GenericArg::Lifetime(l) => l.span,
+ GenericArg::Type(t) => t.span,
+ GenericArg::Const(c) => c.span,
+ GenericArg::Infer(i) => i.span,
+ }
+ }
+
+ pub fn 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 is_synthetic(&self) -> bool {
+ matches!(self, GenericArg::Lifetime(lifetime) if lifetime.name.ident() == Ident::empty())
+ }
+
+ 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(_) => ast::ParamKindOrd::Type,
+ GenericArg::Const(_) => ast::ParamKindOrd::Const,
+ GenericArg::Infer(_) => ast::ParamKindOrd::Infer,
+ }
+ }
+
+ pub fn is_ty_or_const(&self) -> bool {
+ match self {
+ GenericArg::Lifetime(_) => false,
+ GenericArg::Type(_) | GenericArg::Const(_) | GenericArg::Infer(_) => true,
+ }
+ }
+}
+
+#[derive(Debug, 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: bool,
+ /// 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: false, span_ext: DUMMY_SP }
+ }
+
+ pub fn inputs(&self) -> &[Ty<'hir>] {
+ if self.parenthesized {
+ 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`");
+ }
+
+ #[inline]
+ pub fn has_type_params(&self) -> bool {
+ self.args.iter().any(|arg| matches!(arg, GenericArg::Type(_)))
+ }
+
+ 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_type_params(&self) -> usize {
+ self.args.iter().filter(|arg| matches!(arg, GenericArg::Type(_))).count()
+ }
+
+ #[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]
+ pub fn num_generic_params(&self) -> usize {
+ self.args.iter().filter(|arg| !matches!(arg, GenericArg::Lifetime(_))).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()
+ }
+}
+
+/// A modifier on a bound, currently this is only used for `?Sized`, where the
+/// modifier is `Maybe`. Negative bounds should also be handled here.
+#[derive(Copy, Clone, PartialEq, Eq, Encodable, Hash, Debug)]
+#[derive(HashStable_Generic)]
+pub enum TraitBoundModifier {
+ None,
+ 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, Debug, HashStable_Generic)]
+pub enum GenericBound<'hir> {
+ Trait(PolyTraitRef<'hir>, TraitBoundModifier),
+ // FIXME(davidtwco): Introduce `PolyTraitRef::LangItem`
+ LangItemTrait(LangItem, Span, HirId, &'hir GenericArgs<'hir>),
+ Outlives(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::LangItemTrait(_, span, ..) => *span,
+ GenericBound::Outlives(l) => l.span,
+ }
+ }
+}
+
+pub type GenericBounds<'hir> = &'hir [GenericBound<'hir>];
+
+#[derive(Copy, Clone, PartialEq, Eq, Encodable, 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, 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>,
+ },
+}
+
+#[derive(Debug, HashStable_Generic)]
+pub struct GenericParam<'hir> {
+ pub hir_id: HirId,
+ pub name: ParamName,
+ pub span: Span,
+ pub pure_wrt_drop: bool,
+ pub kind: GenericParamKind<'hir>,
+ pub colon_span: Option<Span>,
+}
+
+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 })
+ }
+}
+
+#[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, 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>> {
+ for param in self.params {
+ if name == param.name.ident().name {
+ return Some(param);
+ }
+ }
+ None
+ }
+
+ pub fn spans(&self) -> MultiSpan {
+ if self.params.is_empty() {
+ self.span.into()
+ } else {
+ self.params.iter().map(|p| p.span).collect::<Vec<Span>>().into()
+ }
+ }
+
+ /// If there are generic parameters, return where to introduce a new one.
+ pub fn span_for_param_suggestion(&self) -> Option<Span> {
+ if self.params.iter().any(|p| self.span.contains(p.span)) {
+ // `fn foo<A>(t: impl Trait)`
+ // ^ suggest `, T: Trait` here
+ let span = self.span.with_lo(self.span.hi() - BytePos(1)).shrink_to_lo();
+ Some(span)
+ } else {
+ None
+ }
+ }
+
+ /// `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()
+ .filter(|p| p.in_where_clause())
+ .last()
+ .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();
+ if bs.can_be_used_for_suggestions() { Some(bs.shrink_to_hi()) } else { None }
+ },
+ )
+ }
+
+ pub 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, 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, HashStable_Generic)]
+pub struct WhereBoundPredicate<'hir> {
+ 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().map_or(false, |(def_id, _)| def_id == param_def_id)
+ }
+}
+
+/// A lifetime predicate (e.g., `'a: 'b + 'c`).
+#[derive(Debug, HashStable_Generic)]
+pub struct WhereRegionPredicate<'hir> {
+ pub span: Span,
+ pub in_where_clause: bool,
+ pub lifetime: Lifetime,
+ pub bounds: GenericBounds<'hir>,
+}
+
+impl<'hir> WhereRegionPredicate<'hir> {
+ /// Returns `true` if `param_def_id` matches the `lifetime` of this predicate.
+ pub fn is_param_bound(&self, param_def_id: LocalDefId) -> bool {
+ match self.lifetime.name {
+ LifetimeName::Param(id, _) => id == param_def_id,
+ _ => false,
+ }
+ }
+}
+
+/// An equality predicate (e.g., `T = int`); currently unsupported.
+#[derive(Debug, HashStable_Generic)]
+pub struct WhereEqPredicate<'hir> {
+ pub hir_id: HirId,
+ 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, 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]>,
+ pub hash: Fingerprint,
+}
+
+impl<'tcx> AttributeMap<'tcx> {
+ pub const EMPTY: &'static AttributeMap<'static> =
+ &AttributeMap { map: SortedMap::new(), hash: 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.
+ pub hash_including_bodies: Fingerprint,
+ /// Pre-computed hash of the item signature, sithout recursing into the body.
+ pub hash_without_bodies: 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>>,
+ /// Non-owning definitions contained in this owner.
+ pub local_id_to_def_id: SortedMap<ItemLocalId, LocalDefId>,
+}
+
+impl<'tcx> OwnerNodes<'tcx> {
+ pub fn node(&self) -> OwnerNode<'tcx> {
+ use rustc_index::vec::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")
+ .field("node", &self.nodes[ItemLocalId::from_u32(0)])
+ .field("bodies", &self.bodies)
+ .field("local_id_to_def_id", &self.local_id_to_def_id)
+ .field("hash_without_bodies", &self.hash_without_bodies)
+ .field("hash_including_bodies", &self.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: FxHashMap<LocalDefId, 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: FxHashMap<ItemLocalId, 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>>>,
+ pub hir_hash: Fingerprint,
+}
+
+#[derive(Debug, HashStable_Generic)]
+pub struct Closure<'hir> {
+ pub binder: ClosureBinder,
+ pub capture_clause: CaptureBy,
+ pub bound_generic_params: &'hir [GenericParam<'hir>],
+ pub fn_decl: &'hir FnDecl<'hir>,
+ pub body: BodyId,
+ pub fn_decl_span: 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, 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, 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> {
+ // FIXME(#19596) this is a workaround, but there should be a better way
+ fn walk_short_(&self, it: &mut impl FnMut(&Pat<'hir>) -> bool) -> bool {
+ if !it(self) {
+ return false;
+ }
+
+ use PatKind::*;
+ match self.kind {
+ Wild | 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)
+ }
+
+ // FIXME(#19596) this is a workaround, but there should be a better way
+ fn walk_(&self, it: &mut impl FnMut(&Pat<'hir>) -> bool) {
+ if !it(self) {
+ return;
+ }
+
+ use PatKind::*;
+ match self.kind {
+ Wild | 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
+ })
+ }
+}
+
+/// 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, 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,
+}
+
+/// Explicit binding annotations given in the HIR for a binding. Note
+/// that this is not the final binding *mode* that we infer after type
+/// inference.
+#[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]
+pub enum BindingAnnotation {
+ /// No binding annotation given: this means that the final binding mode
+ /// will depend on whether we have skipped through a `&` reference
+ /// when matching. For example, the `x` in `Some(x)` will have binding
+ /// mode `None`; if you do `let Some(x) = &Some(22)`, it will
+ /// ultimately be inferred to be by-reference.
+ ///
+ /// Note that implicit reference skipping is not implemented yet (#42640).
+ Unannotated,
+
+ /// Annotated with `mut x` -- could be either ref or not, similar to `None`.
+ Mutable,
+
+ /// Annotated as `ref`, like `ref x`
+ Ref,
+
+ /// Annotated as `ref mut x`.
+ RefMut,
+}
+
+#[derive(Copy, Clone, PartialEq, Encodable, 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 => "..",
+ })
+ }
+}
+
+#[derive(Debug, 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 `Option<usize>` denotes its position.
+ /// `0 <= position <= subpats.len()`
+ TupleStruct(QPath<'hir>, &'hir [Pat<'hir>], Option<usize>),
+
+ /// An or-pattern `A | B | C`.
+ /// Invariant: `pats.len() >= 2`.
+ Or(&'hir [Pat<'hir>]),
+
+ /// 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>], Option<usize>),
+
+ /// 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>]),
+}
+
+#[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]
+pub enum BinOpKind {
+ /// The `+` operator (addition).
+ Add,
+ /// The `-` operator (subtraction).
+ Sub,
+ /// The `*` operator (multiplication).
+ Mul,
+ /// The `/` operator (division).
+ Div,
+ /// The `%` operator (modulus).
+ Rem,
+ /// The `&&` operator (logical and).
+ And,
+ /// The `||` operator (logical or).
+ Or,
+ /// The `^` operator (bitwise xor).
+ BitXor,
+ /// The `&` operator (bitwise and).
+ BitAnd,
+ /// The `|` operator (bitwise or).
+ BitOr,
+ /// The `<<` operator (shift left).
+ Shl,
+ /// The `>>` operator (shift right).
+ Shr,
+ /// The `==` operator (equality).
+ Eq,
+ /// The `<` operator (less than).
+ Lt,
+ /// The `<=` operator (less than or equal to).
+ Le,
+ /// The `!=` operator (not equal to).
+ Ne,
+ /// The `>=` operator (greater than or equal to).
+ Ge,
+ /// The `>` operator (greater than).
+ Gt,
+}
+
+impl BinOpKind {
+ pub fn as_str(self) -> &'static str {
+ match self {
+ BinOpKind::Add => "+",
+ BinOpKind::Sub => "-",
+ BinOpKind::Mul => "*",
+ BinOpKind::Div => "/",
+ BinOpKind::Rem => "%",
+ BinOpKind::And => "&&",
+ BinOpKind::Or => "||",
+ BinOpKind::BitXor => "^",
+ BinOpKind::BitAnd => "&",
+ BinOpKind::BitOr => "|",
+ BinOpKind::Shl => "<<",
+ BinOpKind::Shr => ">>",
+ BinOpKind::Eq => "==",
+ BinOpKind::Lt => "<",
+ BinOpKind::Le => "<=",
+ BinOpKind::Ne => "!=",
+ BinOpKind::Ge => ">=",
+ BinOpKind::Gt => ">",
+ }
+ }
+
+ pub fn is_lazy(self) -> bool {
+ matches!(self, BinOpKind::And | BinOpKind::Or)
+ }
+
+ pub fn is_shift(self) -> bool {
+ matches!(self, BinOpKind::Shl | BinOpKind::Shr)
+ }
+
+ pub fn is_comparison(self) -> bool {
+ match self {
+ BinOpKind::Eq
+ | BinOpKind::Lt
+ | BinOpKind::Le
+ | BinOpKind::Ne
+ | BinOpKind::Gt
+ | BinOpKind::Ge => true,
+ BinOpKind::And
+ | BinOpKind::Or
+ | BinOpKind::Add
+ | BinOpKind::Sub
+ | BinOpKind::Mul
+ | BinOpKind::Div
+ | BinOpKind::Rem
+ | BinOpKind::BitXor
+ | BinOpKind::BitAnd
+ | BinOpKind::BitOr
+ | BinOpKind::Shl
+ | BinOpKind::Shr => false,
+ }
+ }
+
+ /// Returns `true` if the binary operator takes its arguments by value.
+ pub fn is_by_value(self) -> bool {
+ !self.is_comparison()
+ }
+}
+
+impl Into<ast::BinOpKind> for BinOpKind {
+ fn into(self) -> ast::BinOpKind {
+ match self {
+ BinOpKind::Add => ast::BinOpKind::Add,
+ BinOpKind::Sub => ast::BinOpKind::Sub,
+ BinOpKind::Mul => ast::BinOpKind::Mul,
+ BinOpKind::Div => ast::BinOpKind::Div,
+ BinOpKind::Rem => ast::BinOpKind::Rem,
+ BinOpKind::And => ast::BinOpKind::And,
+ BinOpKind::Or => ast::BinOpKind::Or,
+ BinOpKind::BitXor => ast::BinOpKind::BitXor,
+ BinOpKind::BitAnd => ast::BinOpKind::BitAnd,
+ BinOpKind::BitOr => ast::BinOpKind::BitOr,
+ BinOpKind::Shl => ast::BinOpKind::Shl,
+ BinOpKind::Shr => ast::BinOpKind::Shr,
+ BinOpKind::Eq => ast::BinOpKind::Eq,
+ BinOpKind::Lt => ast::BinOpKind::Lt,
+ BinOpKind::Le => ast::BinOpKind::Le,
+ BinOpKind::Ne => ast::BinOpKind::Ne,
+ BinOpKind::Ge => ast::BinOpKind::Ge,
+ BinOpKind::Gt => ast::BinOpKind::Gt,
+ }
+ }
+}
+
+pub type BinOp = Spanned<BinOpKind>;
+
+#[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]
+pub enum UnOp {
+ /// The `*` operator (dereferencing).
+ Deref,
+ /// The `!` operator (logical negation).
+ Not,
+ /// The `-` operator (negation).
+ Neg,
+}
+
+impl UnOp {
+ pub fn as_str(self) -> &'static str {
+ match self {
+ Self::Deref => "*",
+ Self::Not => "!",
+ Self::Neg => "-",
+ }
+ }
+
+ /// Returns `true` if the unary operator takes its argument by value.
+ pub fn is_by_value(self) -> bool {
+ matches!(self, Self::Neg | Self::Not)
+ }
+}
+
+/// A statement.
+#[derive(Debug, HashStable_Generic)]
+pub struct Stmt<'hir> {
+ pub hir_id: HirId,
+ pub kind: StmtKind<'hir>,
+ pub span: Span,
+}
+
+/// The contents of a statement.
+#[derive(Debug, 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> = <expr>;`).
+#[derive(Debug, 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, 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, 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>,
+}
+
+#[derive(Debug, 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, 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, Encodable, Debug, HashStable_Generic)]
+pub enum BlockCheckMode {
+ DefaultBlock,
+ UnsafeBlock(UnsafeSource),
+}
+
+#[derive(Copy, Clone, PartialEq, Encodable, Debug, HashStable_Generic)]
+pub enum UnsafeSource {
+ CompilerGenerated,
+ UserProvided,
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, 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)
+/// - `generator_kind` would be `None`
+///
+/// All bodies have an **owner**, which can be accessed via the HIR
+/// map using `body_owner_def_id()`.
+#[derive(Debug, HashStable_Generic)]
+pub struct Body<'hir> {
+ pub params: &'hir [Param<'hir>],
+ pub value: Expr<'hir>,
+ pub generator_kind: Option<GeneratorKind>,
+}
+
+impl<'hir> Body<'hir> {
+ pub fn id(&self) -> BodyId {
+ BodyId { hir_id: self.value.hir_id }
+ }
+
+ pub fn generator_kind(&self) -> Option<GeneratorKind> {
+ self.generator_kind
+ }
+}
+
+/// The type of source expression that caused this generator to be created.
+#[derive(Clone, PartialEq, PartialOrd, Eq, Hash, Debug, Copy)]
+#[derive(HashStable_Generic, Encodable, Decodable)]
+pub enum GeneratorKind {
+ /// An explicit `async` block or the body of an async function.
+ Async(AsyncGeneratorKind),
+
+ /// A generator literal created via a `yield` inside a closure.
+ Gen,
+}
+
+impl fmt::Display for GeneratorKind {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ match self {
+ GeneratorKind::Async(k) => fmt::Display::fmt(k, f),
+ GeneratorKind::Gen => f.write_str("generator"),
+ }
+ }
+}
+
+impl GeneratorKind {
+ pub fn descr(&self) -> &'static str {
+ match self {
+ GeneratorKind::Async(ask) => ask.descr(),
+ GeneratorKind::Gen => "generator",
+ }
+ }
+}
+
+/// In the case of a generator created as part of an async construct,
+/// which kind of async 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, PartialOrd, Eq, Hash, Debug, Copy)]
+#[derive(HashStable_Generic, Encodable, Decodable)]
+pub enum AsyncGeneratorKind {
+ /// An explicit `async` block written by the user.
+ Block,
+
+ /// An explicit `async` closure written by the user.
+ Closure,
+
+ /// The `async` block generated as the body of an async function.
+ Fn,
+}
+
+impl fmt::Display for AsyncGeneratorKind {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.write_str(match self {
+ AsyncGeneratorKind::Block => "`async` block",
+ AsyncGeneratorKind::Closure => "`async` closure body",
+ AsyncGeneratorKind::Fn => "`async fn` body",
+ })
+ }
+}
+
+impl AsyncGeneratorKind {
+ pub fn descr(&self) -> &'static str {
+ match self {
+ AsyncGeneratorKind::Block => "`async` block",
+ AsyncGeneratorKind::Closure => "`async` closure body",
+ AsyncGeneratorKind::Fn => "`async fn` body",
+ }
+ }
+}
+
+#[derive(Copy, Clone, Debug)]
+pub enum BodyOwnerKind {
+ /// Functions and methods.
+ Fn,
+
+ /// Closures
+ Closure,
+
+ /// Constants and associated constants.
+ Const,
+
+ /// 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,
+}
+
+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, PartialEq, Eq, Encodable, 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, body: _ }) => 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_hir_id(..)`
+#[derive(Copy, Clone, PartialEq, Eq, Encodable, Debug, HashStable_Generic)]
+pub struct AnonConst {
+ pub hir_id: HirId,
+ pub body: BodyId,
+}
+
+/// An expression.
+#[derive(Debug)]
+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::Box(_) => ExprPrecedence::Box,
+ 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.into()),
+ 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::InlineAsm(..) => ExprPrecedence::InlineAsm,
+ 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::Let(..)
+ | ExprKind::Loop(..)
+ | ExprKind::Assign(..)
+ | ExprKind::InlineAsm(..)
+ | ExprKind::AssignOp(..)
+ | ExprKind::Lit(_)
+ | ExprKind::ConstBlock(..)
+ | ExprKind::Unary(..)
+ | ExprKind::Box(..)
+ | 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 can_have_side_effects(&self) -> bool {
+ match self.peel_drop_temps().kind {
+ ExprKind::Path(_) | ExprKind::Lit(_) => 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.into_iter())
+ .all(|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().all(|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::Let(..)
+ | ExprKind::Loop(..)
+ | ExprKind::Assign(..)
+ | ExprKind::InlineAsm(..)
+ | ExprKind::AssignOp(..)
+ | ExprKind::ConstBlock(..)
+ | ExprKind::Box(..)
+ | 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::Box(_)
+ | 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, HashStable_Generic)]
+pub enum ExprKind<'hir> {
+ /// A `box x` expression.
+ Box(&'hir Expr<'hir>),
+ /// Allow anonymous constants from an inline `const` block
+ ConstBlock(AnonConst),
+ /// 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 first element of the `&[Expr]` is the expression that evaluates
+ /// to the object on which the method is being called on (the receiver),
+ /// and the remaining elements are the rest of the arguments.
+ /// Thus, `x.foo::<Bar, Baz>(a, b, c, d)` is represented as
+ /// `ExprKind::MethodCall(PathSegment { foo, [Bar, Baz] }, [x, a, b, c, d], 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>], 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(Lit),
+ /// A cast (e.g., `foo as f64`).
+ Cast(&'hir Expr<'hir>, &'hir Ty<'hir>),
+ /// A type reference (e.g., `Foo`).
+ 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 generator 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]`).
+ Index(&'hir Expr<'hir>, &'hir Expr<'hir>),
+
+ /// 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>>),
+
+ /// Inline assembly (from `asm!`), with its outputs and inputs.
+ InlineAsm(&'hir InlineAsm<'hir>),
+
+ /// 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 generators (i.e., `yield <expr>`).
+ Yield(&'hir Expr<'hir>, YieldSource),
+
+ /// A placeholder for an expression that wasn't syntactically well formed in some way.
+ Err,
+}
+
+/// 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, 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. `HirId` of the inner expr.
+ LangItem(LangItem, Span, Option<HirId>),
+}
+
+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,
+ }
+ }
+
+ /// Returns the span of the last segment of this `QPath`. For example, `method` in
+ /// `<() as Trait>::method`.
+ pub fn last_segment_span(&self) -> Span {
+ match *self {
+ QPath::Resolved(_, path) => path.segments.last().unwrap().ident.span,
+ QPath::TypeRelative(_, segment) => segment.ident.span,
+ QPath::LangItem(_, span, _) => span,
+ }
+ }
+}
+
+/// Hints at the original code for a let statement.
+#[derive(Copy, Clone, Encodable, 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, Encodable, Hash, Debug)]
+#[derive(HashStable_Generic)]
+pub enum MatchSource {
+ /// A `match _ { .. }`.
+ Normal,
+ /// A desugared `for _ in _ { .. }` loop.
+ ForLoopDesugar,
+ /// A desugared `?` operator.
+ TryDesugar,
+ /// A desugared `<expr>.await`.
+ AwaitDesugar,
+}
+
+impl MatchSource {
+ #[inline]
+ pub const fn name(self) -> &'static str {
+ use MatchSource::*;
+ match self {
+ Normal => "match",
+ ForLoopDesugar => "for",
+ TryDesugar => "?",
+ AwaitDesugar => ".await",
+ }
+ }
+}
+
+/// The loop type that yielded an `ExprKind::Loop`.
+#[derive(Copy, Clone, PartialEq, Encodable, 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, Encodable, 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, Encodable, 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, PartialEq, Eq, Debug, Encodable, Decodable, 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`",
+ })
+ }
+}
+
+impl From<GeneratorKind> for YieldSource {
+ fn from(kind: GeneratorKind) -> Self {
+ match kind {
+ // Guess based on the kind of the current generator.
+ GeneratorKind::Gen => Self::Yield,
+ GeneratorKind::Async(_) => Self::Await { expr: None },
+ }
+ }
+}
+
+// N.B., if you change this, you'll probably want to change the corresponding
+// type structure in middle/ty.rs as well.
+#[derive(Debug, 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, 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 def_id: LocalDefId,
+}
+
+impl TraitItemId {
+ #[inline]
+ pub fn hir_id(&self) -> HirId {
+ // Items are always HIR owners.
+ HirId::make_owner(self.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, HashStable_Generic)]
+pub struct TraitItem<'hir> {
+ pub ident: Ident,
+ pub def_id: LocalDefId,
+ pub generics: &'hir Generics<'hir>,
+ pub kind: TraitItemKind<'hir>,
+ pub span: Span,
+ pub defaultness: Defaultness,
+}
+
+impl TraitItem<'_> {
+ #[inline]
+ pub fn hir_id(&self) -> HirId {
+ // Items are always HIR owners.
+ HirId::make_owner(self.def_id)
+ }
+
+ pub fn trait_item_id(&self) -> TraitItemId {
+ TraitItemId { def_id: self.def_id }
+ }
+}
+
+/// Represents a trait method's body (or just argument names).
+#[derive(Encodable, Debug, 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, 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 def_id: LocalDefId,
+}
+
+impl ImplItemId {
+ #[inline]
+ pub fn hir_id(&self) -> HirId {
+ // Items are always HIR owners.
+ HirId::make_owner(self.def_id)
+ }
+}
+
+/// Represents anything within an `impl` block.
+#[derive(Debug, HashStable_Generic)]
+pub struct ImplItem<'hir> {
+ pub ident: Ident,
+ pub def_id: LocalDefId,
+ pub generics: &'hir Generics<'hir>,
+ pub kind: ImplItemKind<'hir>,
+ pub defaultness: Defaultness,
+ pub span: Span,
+ pub vis_span: Span,
+}
+
+impl ImplItem<'_> {
+ #[inline]
+ pub fn hir_id(&self) -> HirId {
+ // Items are always HIR owners.
+ HirId::make_owner(self.def_id)
+ }
+
+ pub fn impl_item_id(&self) -> ImplItemId {
+ ImplItemId { def_id: self.def_id }
+ }
+}
+
+/// Represents various kinds of content within an `impl`.
+#[derive(Debug, 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.
+ TyAlias(&'hir Ty<'hir>),
+}
+
+// The name of the associated type for `Fn` return types.
+pub const FN_OUTPUT_NAME: Symbol = sym::Output;
+
+/// 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, 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, 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, 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)]
+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::SelfTy { trait_: Some(def_id), alias_to: None } => Some((def_id, segment.ident)),
+ _ => None,
+ }
+ }
+}
+
+/// Not represented directly in the AST; referred to by name through a `ty_path`.
+#[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Hash, Debug)]
+#[derive(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, 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, HashStable_Generic)]
+pub struct OpaqueTy<'hir> {
+ pub generics: &'hir Generics<'hir>,
+ pub bounds: GenericBounds<'hir>,
+ pub origin: OpaqueTyOrigin,
+}
+
+/// From whence the opaque type came.
+#[derive(Copy, Clone, PartialEq, Eq, Encodable, Decodable, Debug, HashStable_Generic)]
+pub enum OpaqueTyOrigin {
+ /// `-> impl Trait`
+ FnReturn(LocalDefId),
+ /// `async fn`
+ AsyncFn(LocalDefId),
+ /// type aliases: `type Foo = impl Trait;`
+ TyAlias,
+}
+
+/// The various kinds of types recognized by the compiler.
+#[derive(Debug, 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`).
+ Rptr(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`.
+ OpaqueDef(ItemId, &'hir [GenericArg<'hir>]),
+ /// A trait object type `Bound1 + Bound2 + Bound3`
+ /// where `Bound` is a trait or a lifetime.
+ TraitObject(&'hir [PolyTraitRef<'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,
+}
+
+#[derive(Debug, HashStable_Generic)]
+pub enum InlineAsmOperand<'hir> {
+ In {
+ reg: InlineAsmRegOrRegClass,
+ expr: Expr<'hir>,
+ },
+ Out {
+ reg: InlineAsmRegOrRegClass,
+ late: bool,
+ expr: Option<Expr<'hir>>,
+ },
+ InOut {
+ reg: InlineAsmRegOrRegClass,
+ late: bool,
+ expr: Expr<'hir>,
+ },
+ SplitInOut {
+ reg: InlineAsmRegOrRegClass,
+ late: bool,
+ in_expr: Expr<'hir>,
+ out_expr: Option<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, 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, 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, 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,
+}
+
+/// Represents what type of implicit self a function has, if any.
+#[derive(Copy, Clone, 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, PartialOrd, Ord, Encodable, Decodable, Debug)]
+#[derive(HashStable_Generic)]
+pub enum IsAsync {
+ Async,
+ NotAsync,
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, Hash, 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, 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(Encodable, Debug, HashStable_Generic)]
+pub struct Mod<'hir> {
+ pub spans: ModSpans,
+ pub item_ids: &'hir [ItemId],
+}
+
+#[derive(Copy, Clone, Debug, HashStable_Generic, Encodable)]
+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, HashStable_Generic)]
+pub struct EnumDef<'hir> {
+ pub variants: &'hir [Variant<'hir>],
+}
+
+#[derive(Debug, 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 id: HirId,
+ /// 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, Encodable, 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, 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,
+ _ => unreachable!(),
+ }
+ }
+}
+
+#[derive(Clone, Debug, 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, HashStable_Generic)]
+pub struct FieldDef<'hir> {
+ pub span: Span,
+ pub vis_span: Span,
+ pub ident: Ident,
+ pub hir_id: HirId,
+ pub ty: &'hir Ty<'hir>,
+}
+
+impl FieldDef<'_> {
+ // Still necessary in couple of places
+ pub fn is_positional(&self) -> bool {
+ let first = self.ident.as_str().as_bytes()[0];
+ (b'0'..=b'9').contains(&first)
+ }
+}
+
+/// Fields and constructor IDs of enum variants and structs.
+#[derive(Debug, HashStable_Generic)]
+pub enum VariantData<'hir> {
+ /// A struct variant.
+ ///
+ /// E.g., `Bar { .. }` as in `enum Foo { Bar { .. } }`.
+ Struct(&'hir [FieldDef<'hir>], /* recovered */ bool),
+ /// A tuple variant.
+ ///
+ /// E.g., `Bar(..)` as in `enum Foo { Bar(..) }`.
+ Tuple(&'hir [FieldDef<'hir>], HirId),
+ /// A unit variant.
+ ///
+ /// E.g., `Bar = ..` as in `enum Foo { Bar = .. }`.
+ Unit(HirId),
+}
+
+impl<'hir> VariantData<'hir> {
+ /// Return the fields of this variant.
+ pub fn fields(&self) -> &'hir [FieldDef<'hir>] {
+ match *self {
+ VariantData::Struct(ref fields, ..) | VariantData::Tuple(ref fields, ..) => fields,
+ _ => &[],
+ }
+ }
+
+ /// Return the `HirId` of this variant's constructor, if it has one.
+ pub fn ctor_hir_id(&self) -> Option<HirId> {
+ match *self {
+ VariantData::Struct(_, _) => None,
+ VariantData::Tuple(_, hir_id) | VariantData::Unit(hir_id) => Some(hir_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 def_id: LocalDefId,
+}
+
+impl ItemId {
+ #[inline]
+ pub fn hir_id(&self) -> HirId {
+ // Items are always HIR owners.
+ HirId::make_owner(self.def_id)
+ }
+}
+
+/// An item
+///
+/// The name might be a dummy name in case of anonymous items
+#[derive(Debug, HashStable_Generic)]
+pub struct Item<'hir> {
+ pub ident: Ident,
+ pub def_id: LocalDefId,
+ pub kind: ItemKind<'hir>,
+ pub span: Span,
+ pub vis_span: Span,
+}
+
+impl Item<'_> {
+ #[inline]
+ pub fn hir_id(&self) -> HirId {
+ // Items are always HIR owners.
+ HirId::make_owner(self.def_id)
+ }
+
+ pub fn item_id(&self) -> ItemId {
+ ItemId { def_id: self.def_id }
+ }
+}
+
+#[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, PartialOrd, Ord, Hash, Debug)]
+#[derive(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, Encodable, 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, 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 Path<'hir>, UseKind),
+
+ /// A `static` item.
+ Static(&'hir Ty<'hir>, Mutability, BodyId),
+ /// A `const` item.
+ Const(&'hir Ty<'hir>, BodyId),
+ /// A function declaration.
+ Fn(FnSig<'hir>, &'hir Generics<'hir>, BodyId),
+ /// A MBE macro definition (`macro_rules!` or `macro`).
+ Macro(ast::MacroDef, MacroKind),
+ /// A module.
+ Mod(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(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, 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 constness: Constness,
+ 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::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(Encodable, Debug, 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, 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, Encodable, 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 def_id: LocalDefId,
+}
+
+impl ForeignItemId {
+ #[inline]
+ pub fn hir_id(&self) -> HirId {
+ // Items are always HIR owners.
+ HirId::make_owner(self.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, HashStable_Generic)]
+pub struct ForeignItemRef {
+ pub id: ForeignItemId,
+ pub ident: Ident,
+ pub span: Span,
+}
+
+#[derive(Debug, HashStable_Generic)]
+pub struct ForeignItem<'hir> {
+ pub ident: Ident,
+ pub kind: ForeignItemKind<'hir>,
+ pub def_id: LocalDefId,
+ 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.def_id)
+ }
+
+ pub fn foreign_item_id(&self) -> ForeignItemId {
+ ForeignItemId { def_id: self.def_id }
+ }
+}
+
+/// An item within an `extern` block.
+#[derive(Debug, 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, Encodable, 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(Encodable, Decodable, Clone, Debug, 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_decl(&self) -> Option<&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::TraitItem(TraitItem {
+ kind: TraitItemKind::Fn(_, TraitFn::Provided(body_id)),
+ ..
+ })
+ | OwnerNode::ImplItem(ImplItem { kind: ImplItemKind::Fn(_, body_id), .. })
+ | OwnerNode::Item(Item { kind: ItemKind::Fn(.., body_id), .. }) => Some(*body_id),
+ _ => None,
+ }
+ }
+
+ pub fn generics(self) -> Option<&'hir Generics<'hir>> {
+ Node::generics(self.into())
+ }
+
+ pub fn def_id(self) -> LocalDefId {
+ match self {
+ OwnerNode::Item(Item { def_id, .. })
+ | OwnerNode::TraitItem(TraitItem { def_id, .. })
+ | OwnerNode::ImplItem(ImplItem { def_id, .. })
+ | OwnerNode::ForeignItem(ForeignItem { def_id, .. }) => *def_id,
+ OwnerNode::Crate(..) => crate::CRATE_HIR_ID.owner,
+ }
+ }
+
+ pub fn expect_item(self) -> &'hir Item<'hir> {
+ match self {
+ OwnerNode::Item(n) => n,
+ _ => panic!(),
+ }
+ }
+
+ pub fn expect_foreign_item(self) -> &'hir ForeignItem<'hir> {
+ match self {
+ OwnerNode::ForeignItem(n) => n,
+ _ => panic!(),
+ }
+ }
+
+ pub fn expect_impl_item(self) -> &'hir ImplItem<'hir> {
+ match self {
+ OwnerNode::ImplItem(n) => n,
+ _ => panic!(),
+ }
+ }
+
+ pub fn expect_trait_item(self) -> &'hir TraitItem<'hir> {
+ match self {
+ OwnerNode::TraitItem(n) => n,
+ _ => panic!(),
+ }
+ }
+}
+
+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),
+ Expr(&'hir Expr<'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>),
+ 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(tcx.hir().get_parent_node(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.name.ident()),
+ Node::GenericParam(p) => Some(p.name.ident()),
+ Node::TypeBinding(b) => Some(b.ident),
+ Node::Param(..)
+ | Node::AnonConst(..)
+ | 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::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,
+ }
+ }
+
+ pub fn body_id(&self) -> Option<BodyId> {
+ match self {
+ Node::TraitItem(TraitItem {
+ kind: TraitItemKind::Fn(_, TraitFn::Provided(body_id)),
+ ..
+ })
+ | Node::ImplItem(ImplItem { kind: ImplItemKind::Fn(_, body_id), .. })
+ | Node::Item(Item { kind: ItemKind::Fn(.., body_id), .. }) => Some(*body_id),
+ _ => 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,
+ }
+ }
+
+ /// Get the fields for the tuple-constructor,
+ /// if this node is a tuple constructor, otherwise None
+ pub fn tuple_fields(&self) -> Option<&'hir [FieldDef<'hir>]> {
+ if let Node::Ctor(&VariantData::Tuple(fields, _)) = self { Some(fields) } else { None }
+ }
+}
+
+// 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::*;
+ // These are in alphabetical order, which is easy to maintain.
+ rustc_data_structures::static_assert_size!(Block<'static>, 48);
+ rustc_data_structures::static_assert_size!(Expr<'static>, 56);
+ rustc_data_structures::static_assert_size!(ForeignItem<'static>, 72);
+ rustc_data_structures::static_assert_size!(GenericBound<'_>, 48);
+ rustc_data_structures::static_assert_size!(Generics<'static>, 56);
+ rustc_data_structures::static_assert_size!(ImplItem<'static>, 88);
+ rustc_data_structures::static_assert_size!(Impl<'static>, 80);
+ rustc_data_structures::static_assert_size!(Item<'static>, 80);
+ rustc_data_structures::static_assert_size!(Pat<'static>, 88);
+ rustc_data_structures::static_assert_size!(QPath<'static>, 24);
+ rustc_data_structures::static_assert_size!(TraitItem<'static>, 96);
+ rustc_data_structures::static_assert_size!(Ty<'static>, 72);
+}
diff --git a/compiler/rustc_hir/src/hir_id.rs b/compiler/rustc_hir/src/hir_id.rs
new file mode 100644
index 000000000..346ac9e96
--- /dev/null
+++ b/compiler/rustc_hir/src/hir_id.rs
@@ -0,0 +1,89 @@
+use crate::def_id::{LocalDefId, CRATE_DEF_ID};
+use std::fmt;
+
+/// Uniquely identifies a node in the HIR of the current crate. It is
+/// composed of the `owner`, which is the `LocalDefId` of the directly enclosing
+/// `hir::Item`, `hir::TraitItem`, or `hir::ImplItem` (i.e., the closest "item-like"),
+/// and the `local_id` which is unique within the given owner.
+///
+/// This two-level structure makes for more stable values: One can move an item
+/// around within the source code, or add or remove stuff before it, without
+/// the `local_id` part of the `HirId` changing, which is a very useful property in
+/// incremental compilation where we have to persist things through changes to
+/// the code base.
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(Encodable, Decodable, HashStable_Generic)]
+#[rustc_pass_by_value]
+pub struct HirId {
+ pub owner: LocalDefId,
+ pub local_id: ItemLocalId,
+}
+
+impl HirId {
+ #[inline]
+ pub fn expect_owner(self) -> LocalDefId {
+ assert_eq!(self.local_id.index(), 0);
+ self.owner
+ }
+
+ #[inline]
+ pub fn as_owner(self) -> Option<LocalDefId> {
+ if self.local_id.index() == 0 { Some(self.owner) } else { None }
+ }
+
+ #[inline]
+ pub fn is_owner(self) -> bool {
+ self.local_id.index() == 0
+ }
+
+ #[inline]
+ pub fn make_owner(owner: LocalDefId) -> Self {
+ Self { owner, local_id: ItemLocalId::from_u32(0) }
+ }
+
+ pub fn index(self) -> (usize, usize) {
+ (rustc_index::vec::Idx::index(self.owner), rustc_index::vec::Idx::index(self.local_id))
+ }
+}
+
+impl fmt::Display for HirId {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ write!(f, "{:?}", self)
+ }
+}
+
+impl Ord for HirId {
+ fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+ (self.index()).cmp(&(other.index()))
+ }
+}
+
+impl PartialOrd for HirId {
+ fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+ Some(self.cmp(&other))
+ }
+}
+
+rustc_data_structures::define_id_collections!(HirIdMap, HirIdSet, HirId);
+rustc_data_structures::define_id_collections!(ItemLocalMap, ItemLocalSet, ItemLocalId);
+
+rustc_index::newtype_index! {
+ /// An `ItemLocalId` uniquely identifies something within a given "item-like";
+ /// that is, within a `hir::Item`, `hir::TraitItem`, or `hir::ImplItem`. There is no
+ /// guarantee that the numerical value of a given `ItemLocalId` corresponds to
+ /// the node's position within the owning item in any way, but there is a
+ /// guarantee that the `LocalItemId`s within an owner occupy a dense range of
+ /// integers starting at zero, so a mapping that maps all or most nodes within
+ /// an "item-like" to something else can be implemented by a `Vec` instead of a
+ /// tree or hash map.
+ #[derive(HashStable_Generic)]
+ pub struct ItemLocalId { .. }
+}
+
+impl ItemLocalId {
+ /// Signal local id which should never be used.
+ pub const INVALID: ItemLocalId = ItemLocalId::MAX;
+}
+
+/// The `HirId` corresponding to `CRATE_NODE_ID` and `CRATE_DEF_ID`.
+pub const CRATE_HIR_ID: HirId = HirId { owner: CRATE_DEF_ID, local_id: ItemLocalId::from_u32(0) };
diff --git a/compiler/rustc_hir/src/intravisit.rs b/compiler/rustc_hir/src/intravisit.rs
new file mode 100644
index 000000000..e676acebe
--- /dev/null
+++ b/compiler/rustc_hir/src/intravisit.rs
@@ -0,0 +1,1232 @@
+//! HIR walker for walking the contents of nodes.
+//!
+//! Here are the three available patterns for the visitor strategy,
+//! in roughly the order of desirability:
+//!
+//! 1. **Shallow visit**: Get a simple callback for every item (or item-like thing) in the HIR.
+//! - Example: find all items with a `#[foo]` attribute on them.
+//! - How: Use the `hir_crate_items` or `hir_module_items` query to traverse over item-like ids
+//! (ItemId, TraitItemId, etc.) and use tcx.def_kind and `tcx.hir().item*(id)` to filter and
+//! access actual item-like thing, respectively.
+//! - Pro: Efficient; just walks the lists of item ids and gives users control whether to access
+//! the hir_owners themselves or not.
+//! - Con: Don't get information about nesting
+//! - Con: Don't have methods for specific bits of HIR, like "on
+//! every expr, do this".
+//! 2. **Deep visit**: Want to scan for specific kinds of HIR nodes within
+//! an item, but don't care about how item-like things are nested
+//! within one another.
+//! - Example: Examine each expression to look for its type and do some check or other.
+//! - How: Implement `intravisit::Visitor` and override the `NestedFilter` type to
+//! `nested_filter::OnlyBodies` (and implement `nested_visit_map`), and use
+//! `tcx.hir().visit_all_item_likes_in_crate(&mut visitor)`. Within your
+//! `intravisit::Visitor` impl, implement methods like `visit_expr()` (don't forget to invoke
+//! `intravisit::walk_expr()` to keep walking the subparts).
+//! - Pro: Visitor methods for any kind of HIR node, not just item-like things.
+//! - Pro: Integrates well into dependency tracking.
+//! - Con: Don't get information about nesting between items
+//! 3. **Nested visit**: Want to visit the whole HIR and you care about the nesting between
+//! item-like things.
+//! - Example: Lifetime resolution, which wants to bring lifetimes declared on the
+//! impl into scope while visiting the impl-items, and then back out again.
+//! - How: Implement `intravisit::Visitor` and override the `NestedFilter` type to
+//! `nested_filter::All` (and implement `nested_visit_map`). Walk your crate with
+//! `tcx.hir().walk_toplevel_module(visitor)` invoked on `tcx.hir().krate()`.
+//! - Pro: Visitor methods for any kind of HIR node, not just item-like things.
+//! - Pro: Preserves nesting information
+//! - Con: Does not integrate well into dependency tracking.
+//!
+//! If you have decided to use this visitor, here are some general
+//! notes on how to do so:
+//!
+//! Each overridden visit method has full control over what
+//! happens with its node, it can do its own traversal of the node's children,
+//! call `intravisit::walk_*` to apply the default traversal algorithm, or prevent
+//! deeper traversal by doing nothing.
+//!
+//! When visiting the HIR, the contents of nested items are NOT visited
+//! by default. This is different from the AST visitor, which does a deep walk.
+//! Hence this module is called `intravisit`; see the method `visit_nested_item`
+//! for more details.
+//!
+//! Note: it is an important invariant that the default visitor walks
+//! the body of a function in "execution order" - more concretely, if
+//! we consider the reverse post-order (RPO) of the CFG implied by the HIR,
+//! then a pre-order traversal of the HIR is consistent with the CFG RPO
+//! on the *initial CFG point* of each HIR node, while a post-order traversal
+//! of the HIR is consistent with the CFG RPO on each *final CFG point* of
+//! each CFG node.
+//!
+//! One thing that follows is that if HIR node A always starts/ends executing
+//! before HIR node B, then A appears in traversal pre/postorder before B,
+//! respectively. (This follows from RPO respecting CFG domination).
+//!
+//! This order consistency is required in a few places in rustc, for
+//! example generator inference, and possibly also HIR borrowck.
+
+use crate::hir::*;
+use rustc_ast::walk_list;
+use rustc_ast::{Attribute, Label};
+use rustc_span::symbol::{Ident, Symbol};
+use rustc_span::Span;
+
+pub trait IntoVisitor<'hir> {
+ type Visitor: Visitor<'hir>;
+ fn into_visitor(&self) -> Self::Visitor;
+}
+
+#[derive(Copy, Clone, Debug)]
+pub enum FnKind<'a> {
+ /// `#[xxx] pub async/const/extern "Abi" fn foo()`
+ ItemFn(Ident, &'a Generics<'a>, FnHeader),
+
+ /// `fn foo(&self)`
+ Method(Ident, &'a FnSig<'a>),
+
+ /// `|x, y| {}`
+ Closure,
+}
+
+impl<'a> FnKind<'a> {
+ pub fn header(&self) -> Option<&FnHeader> {
+ match *self {
+ FnKind::ItemFn(_, _, ref header) => Some(header),
+ FnKind::Method(_, ref sig) => Some(&sig.header),
+ FnKind::Closure => None,
+ }
+ }
+
+ pub fn constness(self) -> Constness {
+ self.header().map_or(Constness::NotConst, |header| header.constness)
+ }
+
+ pub fn asyncness(self) -> IsAsync {
+ self.header().map_or(IsAsync::NotAsync, |header| header.asyncness)
+ }
+}
+
+/// An abstract representation of the HIR `rustc_middle::hir::map::Map`.
+pub trait Map<'hir> {
+ /// Retrieves the `Node` corresponding to `id`, returning `None` if cannot be found.
+ fn find(&self, hir_id: HirId) -> Option<Node<'hir>>;
+ fn body(&self, id: BodyId) -> &'hir Body<'hir>;
+ fn item(&self, id: ItemId) -> &'hir Item<'hir>;
+ fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir>;
+ fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem<'hir>;
+ fn foreign_item(&self, id: ForeignItemId) -> &'hir ForeignItem<'hir>;
+}
+
+// Used when no map is actually available, forcing manual implementation of nested visitors.
+impl<'hir> Map<'hir> for ! {
+ fn find(&self, _: HirId) -> Option<Node<'hir>> {
+ *self;
+ }
+ fn body(&self, _: BodyId) -> &'hir Body<'hir> {
+ *self;
+ }
+ fn item(&self, _: ItemId) -> &'hir Item<'hir> {
+ *self;
+ }
+ fn trait_item(&self, _: TraitItemId) -> &'hir TraitItem<'hir> {
+ *self;
+ }
+ fn impl_item(&self, _: ImplItemId) -> &'hir ImplItem<'hir> {
+ *self;
+ }
+ fn foreign_item(&self, _: ForeignItemId) -> &'hir ForeignItem<'hir> {
+ *self;
+ }
+}
+
+pub mod nested_filter {
+ use super::Map;
+
+ /// Specifies what nested things a visitor wants to visit. By "nested
+ /// things", we are referring to bits of HIR that are not directly embedded
+ /// within one another but rather indirectly, through a table in the crate.
+ /// This is done to control dependencies during incremental compilation: the
+ /// non-inline bits of HIR can be tracked and hashed separately.
+ ///
+ /// The most common choice is `OnlyBodies`, which will cause the visitor to
+ /// visit fn bodies for fns that it encounters, and closure bodies, but
+ /// skip over nested item-like things.
+ ///
+ /// See the comments on `ItemLikeVisitor` for more details on the overall
+ /// visit strategy.
+ pub trait NestedFilter<'hir> {
+ type Map: Map<'hir>;
+
+ /// Whether the visitor visits nested "item-like" things.
+ /// E.g., item, impl-item.
+ const INTER: bool;
+ /// Whether the visitor visits "intra item-like" things.
+ /// E.g., function body, closure, `AnonConst`
+ const INTRA: bool;
+ }
+
+ /// Do not visit any nested things. When you add a new
+ /// "non-nested" thing, you will want to audit such uses to see if
+ /// they remain valid.
+ ///
+ /// Use this if you are only walking some particular kind of tree
+ /// (i.e., a type, or fn signature) and you don't want to thread a
+ /// HIR map around.
+ pub struct None(());
+ impl NestedFilter<'_> for None {
+ type Map = !;
+ const INTER: bool = false;
+ const INTRA: bool = false;
+ }
+}
+
+use nested_filter::NestedFilter;
+
+/// Each method of the Visitor trait is a hook to be potentially
+/// overridden. Each method's default implementation recursively visits
+/// the substructure of the input via the corresponding `walk` method;
+/// e.g., the `visit_mod` method by default calls `intravisit::walk_mod`.
+///
+/// Note that this visitor does NOT visit nested items by default
+/// (this is why the module is called `intravisit`, to distinguish it
+/// from the AST's `visit` module, which acts differently). If you
+/// simply want to visit all items in the crate in some order, you
+/// should call `tcx.hir().visit_all_item_likes_in_crate`. Otherwise, see the comment
+/// on `visit_nested_item` for details on how to visit nested items.
+///
+/// If you want to ensure that your code handles every variant
+/// explicitly, you need to override each method. (And you also need
+/// to monitor future changes to `Visitor` in case a new method with a
+/// new default implementation gets introduced.)
+pub trait Visitor<'v>: Sized {
+ // this type should not be overridden, it exists for convenient usage as `Self::Map`
+ type Map: Map<'v> = <Self::NestedFilter as NestedFilter<'v>>::Map;
+
+ ///////////////////////////////////////////////////////////////////////////
+ // Nested items.
+
+ /// Override this type to control which nested HIR are visited; see
+ /// [`NestedFilter`] for details. If you override this type, you
+ /// must also override [`nested_visit_map`](Self::nested_visit_map).
+ ///
+ /// **If for some reason you want the nested behavior, but don't
+ /// have a `Map` at your disposal:** then override the
+ /// `visit_nested_XXX` methods. If a new `visit_nested_XXX` variant is
+ /// added in the future, it will cause a panic which can be detected
+ /// and fixed appropriately.
+ type NestedFilter: NestedFilter<'v> = nested_filter::None;
+
+ /// If `type NestedFilter` is set to visit nested items, this method
+ /// must also be overridden to provide a map to retrieve nested items.
+ fn nested_visit_map(&mut self) -> Self::Map {
+ panic!(
+ "nested_visit_map must be implemented or consider using \
+ `type NestedFilter = nested_filter::None` (the default)"
+ );
+ }
+
+ /// Invoked when a nested item is encountered. By default, when
+ /// `Self::NestedFilter` is `nested_filter::None`, this method does
+ /// nothing. **You probably don't want to override this method** --
+ /// instead, override [`Self::NestedFilter`] or use the "shallow" or
+ /// "deep" visit patterns described on
+ /// `itemlikevisit::ItemLikeVisitor`. The only reason to override
+ /// this method is if you want a nested pattern but cannot supply a
+ /// [`Map`]; see `nested_visit_map` for advice.
+ fn visit_nested_item(&mut self, id: ItemId) {
+ if Self::NestedFilter::INTER {
+ let item = self.nested_visit_map().item(id);
+ self.visit_item(item);
+ }
+ }
+
+ /// Like `visit_nested_item()`, but for trait items. See
+ /// `visit_nested_item()` for advice on when to override this
+ /// method.
+ fn visit_nested_trait_item(&mut self, id: TraitItemId) {
+ if Self::NestedFilter::INTER {
+ let item = self.nested_visit_map().trait_item(id);
+ self.visit_trait_item(item);
+ }
+ }
+
+ /// Like `visit_nested_item()`, but for impl items. See
+ /// `visit_nested_item()` for advice on when to override this
+ /// method.
+ fn visit_nested_impl_item(&mut self, id: ImplItemId) {
+ if Self::NestedFilter::INTER {
+ let item = self.nested_visit_map().impl_item(id);
+ self.visit_impl_item(item);
+ }
+ }
+
+ /// Like `visit_nested_item()`, but for foreign items. See
+ /// `visit_nested_item()` for advice on when to override this
+ /// method.
+ fn visit_nested_foreign_item(&mut self, id: ForeignItemId) {
+ if Self::NestedFilter::INTER {
+ let item = self.nested_visit_map().foreign_item(id);
+ self.visit_foreign_item(item);
+ }
+ }
+
+ /// Invoked to visit the body of a function, method or closure. Like
+ /// `visit_nested_item`, does nothing by default unless you override
+ /// `Self::NestedFilter`.
+ fn visit_nested_body(&mut self, id: BodyId) {
+ if Self::NestedFilter::INTRA {
+ let body = self.nested_visit_map().body(id);
+ self.visit_body(body);
+ }
+ }
+
+ fn visit_param(&mut self, param: &'v Param<'v>) {
+ walk_param(self, param)
+ }
+
+ /// Visits the top-level item and (optionally) nested items / impl items. See
+ /// `visit_nested_item` for details.
+ fn visit_item(&mut self, i: &'v Item<'v>) {
+ walk_item(self, i)
+ }
+
+ fn visit_body(&mut self, b: &'v Body<'v>) {
+ walk_body(self, b);
+ }
+
+ ///////////////////////////////////////////////////////////////////////////
+
+ fn visit_id(&mut self, _hir_id: HirId) {
+ // Nothing to do.
+ }
+ fn visit_name(&mut self, _span: Span, _name: Symbol) {
+ // Nothing to do.
+ }
+ fn visit_ident(&mut self, ident: Ident) {
+ walk_ident(self, ident)
+ }
+ fn visit_mod(&mut self, m: &'v Mod<'v>, _s: Span, n: HirId) {
+ walk_mod(self, m, n)
+ }
+ fn visit_foreign_item(&mut self, i: &'v ForeignItem<'v>) {
+ walk_foreign_item(self, i)
+ }
+ fn visit_local(&mut self, l: &'v Local<'v>) {
+ walk_local(self, l)
+ }
+ fn visit_block(&mut self, b: &'v Block<'v>) {
+ walk_block(self, b)
+ }
+ fn visit_stmt(&mut self, s: &'v Stmt<'v>) {
+ walk_stmt(self, s)
+ }
+ fn visit_arm(&mut self, a: &'v Arm<'v>) {
+ walk_arm(self, a)
+ }
+ fn visit_pat(&mut self, p: &'v Pat<'v>) {
+ walk_pat(self, p)
+ }
+ fn visit_array_length(&mut self, len: &'v ArrayLen) {
+ walk_array_len(self, len)
+ }
+ fn visit_anon_const(&mut self, c: &'v AnonConst) {
+ walk_anon_const(self, c)
+ }
+ fn visit_expr(&mut self, ex: &'v Expr<'v>) {
+ walk_expr(self, ex)
+ }
+ fn visit_let_expr(&mut self, lex: &'v Let<'v>) {
+ walk_let_expr(self, lex)
+ }
+ fn visit_ty(&mut self, t: &'v Ty<'v>) {
+ walk_ty(self, t)
+ }
+ fn visit_generic_param(&mut self, p: &'v GenericParam<'v>) {
+ walk_generic_param(self, p)
+ }
+ fn visit_const_param_default(&mut self, _param: HirId, ct: &'v AnonConst) {
+ walk_const_param_default(self, ct)
+ }
+ fn visit_generics(&mut self, g: &'v Generics<'v>) {
+ walk_generics(self, g)
+ }
+ fn visit_where_predicate(&mut self, predicate: &'v WherePredicate<'v>) {
+ walk_where_predicate(self, predicate)
+ }
+ fn visit_fn_decl(&mut self, fd: &'v FnDecl<'v>) {
+ walk_fn_decl(self, fd)
+ }
+ fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl<'v>, b: BodyId, s: Span, id: HirId) {
+ walk_fn(self, fk, fd, b, s, id)
+ }
+ fn visit_use(&mut self, path: &'v Path<'v>, hir_id: HirId) {
+ walk_use(self, path, hir_id)
+ }
+ fn visit_trait_item(&mut self, ti: &'v TraitItem<'v>) {
+ walk_trait_item(self, ti)
+ }
+ fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) {
+ walk_trait_item_ref(self, ii)
+ }
+ fn visit_impl_item(&mut self, ii: &'v ImplItem<'v>) {
+ walk_impl_item(self, ii)
+ }
+ fn visit_foreign_item_ref(&mut self, ii: &'v ForeignItemRef) {
+ walk_foreign_item_ref(self, ii)
+ }
+ fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef) {
+ walk_impl_item_ref(self, ii)
+ }
+ fn visit_trait_ref(&mut self, t: &'v TraitRef<'v>) {
+ walk_trait_ref(self, t)
+ }
+ fn visit_param_bound(&mut self, bounds: &'v GenericBound<'v>) {
+ walk_param_bound(self, bounds)
+ }
+ fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef<'v>, m: TraitBoundModifier) {
+ walk_poly_trait_ref(self, t, m)
+ }
+ fn visit_variant_data(
+ &mut self,
+ s: &'v VariantData<'v>,
+ _: Symbol,
+ _: &'v Generics<'v>,
+ _parent_id: HirId,
+ _: Span,
+ ) {
+ walk_struct_def(self, s)
+ }
+ fn visit_field_def(&mut self, s: &'v FieldDef<'v>) {
+ walk_field_def(self, s)
+ }
+ fn visit_enum_def(
+ &mut self,
+ enum_definition: &'v EnumDef<'v>,
+ generics: &'v Generics<'v>,
+ item_id: HirId,
+ _: Span,
+ ) {
+ walk_enum_def(self, enum_definition, generics, item_id)
+ }
+ fn visit_variant(&mut self, v: &'v Variant<'v>, g: &'v Generics<'v>, item_id: HirId) {
+ walk_variant(self, v, g, item_id)
+ }
+ fn visit_label(&mut self, label: &'v Label) {
+ walk_label(self, label)
+ }
+ fn visit_infer(&mut self, inf: &'v InferArg) {
+ walk_inf(self, inf);
+ }
+ fn visit_generic_arg(&mut self, generic_arg: &'v GenericArg<'v>) {
+ match generic_arg {
+ GenericArg::Lifetime(lt) => self.visit_lifetime(lt),
+ GenericArg::Type(ty) => self.visit_ty(ty),
+ GenericArg::Const(ct) => self.visit_anon_const(&ct.value),
+ GenericArg::Infer(inf) => self.visit_infer(inf),
+ }
+ }
+ fn visit_lifetime(&mut self, lifetime: &'v Lifetime) {
+ walk_lifetime(self, lifetime)
+ }
+ fn visit_qpath(&mut self, qpath: &'v QPath<'v>, id: HirId, span: Span) {
+ walk_qpath(self, qpath, id, span)
+ }
+ fn visit_path(&mut self, path: &'v Path<'v>, _id: HirId) {
+ walk_path(self, path)
+ }
+ fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment<'v>) {
+ walk_path_segment(self, path_span, path_segment)
+ }
+ fn visit_generic_args(&mut self, path_span: Span, generic_args: &'v GenericArgs<'v>) {
+ walk_generic_args(self, path_span, generic_args)
+ }
+ fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding<'v>) {
+ walk_assoc_type_binding(self, type_binding)
+ }
+ fn visit_attribute(&mut self, _attr: &'v Attribute) {}
+ fn visit_associated_item_kind(&mut self, kind: &'v AssocItemKind) {
+ walk_associated_item_kind(self, kind);
+ }
+ fn visit_defaultness(&mut self, defaultness: &'v Defaultness) {
+ walk_defaultness(self, defaultness);
+ }
+ fn visit_inline_asm(&mut self, asm: &'v InlineAsm<'v>, id: HirId) {
+ walk_inline_asm(self, asm, id);
+ }
+}
+
+pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod<'v>, mod_hir_id: HirId) {
+ visitor.visit_id(mod_hir_id);
+ for &item_id in module.item_ids {
+ visitor.visit_nested_item(item_id);
+ }
+}
+
+pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body<'v>) {
+ walk_list!(visitor, visit_param, body.params);
+ visitor.visit_expr(&body.value);
+}
+
+pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local<'v>) {
+ // Intentionally visiting the expr first - the initialization expr
+ // dominates the local's definition.
+ walk_list!(visitor, visit_expr, &local.init);
+ visitor.visit_id(local.hir_id);
+ visitor.visit_pat(&local.pat);
+ if let Some(els) = local.els {
+ visitor.visit_block(els);
+ }
+ walk_list!(visitor, visit_ty, &local.ty);
+}
+
+pub fn walk_ident<'v, V: Visitor<'v>>(visitor: &mut V, ident: Ident) {
+ visitor.visit_name(ident.span, ident.name);
+}
+
+pub fn walk_label<'v, V: Visitor<'v>>(visitor: &mut V, label: &'v Label) {
+ visitor.visit_ident(label.ident);
+}
+
+pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) {
+ visitor.visit_id(lifetime.hir_id);
+ match lifetime.name {
+ LifetimeName::Param(_, ParamName::Plain(ident)) => {
+ visitor.visit_ident(ident);
+ }
+ LifetimeName::Param(_, ParamName::Fresh)
+ | LifetimeName::Param(_, ParamName::Error)
+ | LifetimeName::Static
+ | LifetimeName::Error
+ | LifetimeName::ImplicitObjectLifetimeDefault
+ | LifetimeName::Infer => {}
+ }
+}
+
+pub fn walk_poly_trait_ref<'v, V: Visitor<'v>>(
+ visitor: &mut V,
+ trait_ref: &'v PolyTraitRef<'v>,
+ _modifier: TraitBoundModifier,
+) {
+ walk_list!(visitor, visit_generic_param, trait_ref.bound_generic_params);
+ visitor.visit_trait_ref(&trait_ref.trait_ref);
+}
+
+pub fn walk_trait_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_ref: &'v TraitRef<'v>) {
+ visitor.visit_id(trait_ref.hir_ref_id);
+ visitor.visit_path(&trait_ref.path, trait_ref.hir_ref_id)
+}
+
+pub fn walk_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v Param<'v>) {
+ visitor.visit_id(param.hir_id);
+ visitor.visit_pat(&param.pat);
+}
+
+pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) {
+ visitor.visit_ident(item.ident);
+ match item.kind {
+ ItemKind::ExternCrate(orig_name) => {
+ visitor.visit_id(item.hir_id());
+ if let Some(orig_name) = orig_name {
+ visitor.visit_name(item.span, orig_name);
+ }
+ }
+ ItemKind::Use(ref path, _) => {
+ visitor.visit_use(path, item.hir_id());
+ }
+ ItemKind::Static(ref typ, _, body) | ItemKind::Const(ref typ, body) => {
+ visitor.visit_id(item.hir_id());
+ visitor.visit_ty(typ);
+ visitor.visit_nested_body(body);
+ }
+ ItemKind::Fn(ref sig, ref generics, body_id) => visitor.visit_fn(
+ FnKind::ItemFn(item.ident, generics, sig.header),
+ &sig.decl,
+ body_id,
+ item.span,
+ item.hir_id(),
+ ),
+ ItemKind::Macro(..) => {
+ visitor.visit_id(item.hir_id());
+ }
+ ItemKind::Mod(ref module) => {
+ // `visit_mod()` takes care of visiting the `Item`'s `HirId`.
+ visitor.visit_mod(module, item.span, item.hir_id())
+ }
+ ItemKind::ForeignMod { abi: _, items } => {
+ visitor.visit_id(item.hir_id());
+ walk_list!(visitor, visit_foreign_item_ref, items);
+ }
+ ItemKind::GlobalAsm(asm) => {
+ visitor.visit_id(item.hir_id());
+ visitor.visit_inline_asm(asm, item.hir_id());
+ }
+ ItemKind::TyAlias(ref ty, ref generics) => {
+ visitor.visit_id(item.hir_id());
+ visitor.visit_ty(ty);
+ visitor.visit_generics(generics)
+ }
+ ItemKind::OpaqueTy(OpaqueTy { ref generics, bounds, .. }) => {
+ visitor.visit_id(item.hir_id());
+ walk_generics(visitor, generics);
+ walk_list!(visitor, visit_param_bound, bounds);
+ }
+ ItemKind::Enum(ref enum_definition, ref generics) => {
+ visitor.visit_generics(generics);
+ // `visit_enum_def()` takes care of visiting the `Item`'s `HirId`.
+ visitor.visit_enum_def(enum_definition, generics, item.hir_id(), item.span)
+ }
+ ItemKind::Impl(Impl {
+ unsafety: _,
+ defaultness: _,
+ polarity: _,
+ constness: _,
+ defaultness_span: _,
+ ref generics,
+ ref of_trait,
+ ref self_ty,
+ items,
+ }) => {
+ visitor.visit_id(item.hir_id());
+ visitor.visit_generics(generics);
+ walk_list!(visitor, visit_trait_ref, of_trait);
+ visitor.visit_ty(self_ty);
+ walk_list!(visitor, visit_impl_item_ref, *items);
+ }
+ ItemKind::Struct(ref struct_definition, ref generics)
+ | ItemKind::Union(ref struct_definition, ref generics) => {
+ visitor.visit_generics(generics);
+ visitor.visit_id(item.hir_id());
+ visitor.visit_variant_data(
+ struct_definition,
+ item.ident.name,
+ generics,
+ item.hir_id(),
+ item.span,
+ );
+ }
+ ItemKind::Trait(.., ref generics, bounds, trait_item_refs) => {
+ visitor.visit_id(item.hir_id());
+ visitor.visit_generics(generics);
+ walk_list!(visitor, visit_param_bound, bounds);
+ walk_list!(visitor, visit_trait_item_ref, trait_item_refs);
+ }
+ ItemKind::TraitAlias(ref generics, bounds) => {
+ visitor.visit_id(item.hir_id());
+ visitor.visit_generics(generics);
+ walk_list!(visitor, visit_param_bound, bounds);
+ }
+ }
+}
+
+pub fn walk_inline_asm<'v, V: Visitor<'v>>(visitor: &mut V, asm: &'v InlineAsm<'v>, id: HirId) {
+ for (op, op_sp) in asm.operands {
+ match op {
+ InlineAsmOperand::In { expr, .. } | InlineAsmOperand::InOut { expr, .. } => {
+ visitor.visit_expr(expr)
+ }
+ InlineAsmOperand::Out { expr, .. } => {
+ if let Some(expr) = expr {
+ visitor.visit_expr(expr);
+ }
+ }
+ InlineAsmOperand::SplitInOut { in_expr, out_expr, .. } => {
+ visitor.visit_expr(in_expr);
+ if let Some(out_expr) = out_expr {
+ visitor.visit_expr(out_expr);
+ }
+ }
+ InlineAsmOperand::Const { anon_const, .. }
+ | InlineAsmOperand::SymFn { anon_const, .. } => visitor.visit_anon_const(anon_const),
+ InlineAsmOperand::SymStatic { path, .. } => visitor.visit_qpath(path, id, *op_sp),
+ }
+ }
+}
+
+pub fn walk_use<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>, hir_id: HirId) {
+ visitor.visit_id(hir_id);
+ visitor.visit_path(path, hir_id);
+}
+
+pub fn walk_enum_def<'v, V: Visitor<'v>>(
+ visitor: &mut V,
+ enum_definition: &'v EnumDef<'v>,
+ generics: &'v Generics<'v>,
+ item_id: HirId,
+) {
+ visitor.visit_id(item_id);
+ walk_list!(visitor, visit_variant, enum_definition.variants, generics, item_id);
+}
+
+pub fn walk_variant<'v, V: Visitor<'v>>(
+ visitor: &mut V,
+ variant: &'v Variant<'v>,
+ generics: &'v Generics<'v>,
+ parent_item_id: HirId,
+) {
+ visitor.visit_ident(variant.ident);
+ visitor.visit_id(variant.id);
+ visitor.visit_variant_data(
+ &variant.data,
+ variant.ident.name,
+ generics,
+ parent_item_id,
+ variant.span,
+ );
+ walk_list!(visitor, visit_anon_const, &variant.disr_expr);
+}
+
+pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty<'v>) {
+ visitor.visit_id(typ.hir_id);
+
+ match typ.kind {
+ TyKind::Slice(ref ty) => visitor.visit_ty(ty),
+ TyKind::Ptr(ref mutable_type) => visitor.visit_ty(&mutable_type.ty),
+ TyKind::Rptr(ref lifetime, ref mutable_type) => {
+ visitor.visit_lifetime(lifetime);
+ visitor.visit_ty(&mutable_type.ty)
+ }
+ TyKind::Never => {}
+ TyKind::Tup(tuple_element_types) => {
+ walk_list!(visitor, visit_ty, tuple_element_types);
+ }
+ TyKind::BareFn(ref function_declaration) => {
+ walk_list!(visitor, visit_generic_param, function_declaration.generic_params);
+ visitor.visit_fn_decl(&function_declaration.decl);
+ }
+ TyKind::Path(ref qpath) => {
+ visitor.visit_qpath(qpath, typ.hir_id, typ.span);
+ }
+ TyKind::OpaqueDef(item_id, lifetimes) => {
+ visitor.visit_nested_item(item_id);
+ walk_list!(visitor, visit_generic_arg, lifetimes);
+ }
+ TyKind::Array(ref ty, ref length) => {
+ visitor.visit_ty(ty);
+ visitor.visit_array_length(length)
+ }
+ TyKind::TraitObject(bounds, ref lifetime, _syntax) => {
+ for bound in bounds {
+ visitor.visit_poly_trait_ref(bound, TraitBoundModifier::None);
+ }
+ visitor.visit_lifetime(lifetime);
+ }
+ TyKind::Typeof(ref expression) => visitor.visit_anon_const(expression),
+ TyKind::Infer | TyKind::Err => {}
+ }
+}
+
+pub fn walk_inf<'v, V: Visitor<'v>>(visitor: &mut V, inf: &'v InferArg) {
+ visitor.visit_id(inf.hir_id);
+}
+
+pub fn walk_qpath<'v, V: Visitor<'v>>(
+ visitor: &mut V,
+ qpath: &'v QPath<'v>,
+ id: HirId,
+ span: Span,
+) {
+ match *qpath {
+ QPath::Resolved(ref maybe_qself, ref path) => {
+ walk_list!(visitor, visit_ty, maybe_qself);
+ visitor.visit_path(path, id)
+ }
+ QPath::TypeRelative(ref qself, ref segment) => {
+ visitor.visit_ty(qself);
+ visitor.visit_path_segment(span, segment);
+ }
+ QPath::LangItem(..) => {}
+ }
+}
+
+pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>) {
+ for segment in path.segments {
+ visitor.visit_path_segment(path.span, segment);
+ }
+}
+
+pub fn walk_path_segment<'v, V: Visitor<'v>>(
+ visitor: &mut V,
+ path_span: Span,
+ segment: &'v PathSegment<'v>,
+) {
+ visitor.visit_ident(segment.ident);
+ walk_list!(visitor, visit_id, segment.hir_id);
+ if let Some(ref args) = segment.args {
+ visitor.visit_generic_args(path_span, args);
+ }
+}
+
+pub fn walk_generic_args<'v, V: Visitor<'v>>(
+ visitor: &mut V,
+ _path_span: Span,
+ generic_args: &'v GenericArgs<'v>,
+) {
+ walk_list!(visitor, visit_generic_arg, generic_args.args);
+ walk_list!(visitor, visit_assoc_type_binding, generic_args.bindings);
+}
+
+pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(
+ visitor: &mut V,
+ type_binding: &'v TypeBinding<'v>,
+) {
+ visitor.visit_id(type_binding.hir_id);
+ visitor.visit_ident(type_binding.ident);
+ visitor.visit_generic_args(type_binding.span, type_binding.gen_args);
+ match type_binding.kind {
+ TypeBindingKind::Equality { ref term } => match term {
+ Term::Ty(ref ty) => visitor.visit_ty(ty),
+ Term::Const(ref c) => visitor.visit_anon_const(c),
+ },
+ TypeBindingKind::Constraint { bounds } => walk_list!(visitor, visit_param_bound, bounds),
+ }
+}
+
+pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat<'v>) {
+ visitor.visit_id(pattern.hir_id);
+ match pattern.kind {
+ PatKind::TupleStruct(ref qpath, children, _) => {
+ visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
+ walk_list!(visitor, visit_pat, children);
+ }
+ PatKind::Path(ref qpath) => {
+ visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
+ }
+ PatKind::Struct(ref qpath, fields, _) => {
+ visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
+ for field in fields {
+ visitor.visit_id(field.hir_id);
+ visitor.visit_ident(field.ident);
+ visitor.visit_pat(&field.pat)
+ }
+ }
+ PatKind::Or(pats) => walk_list!(visitor, visit_pat, pats),
+ PatKind::Tuple(tuple_elements, _) => {
+ walk_list!(visitor, visit_pat, tuple_elements);
+ }
+ PatKind::Box(ref subpattern) | PatKind::Ref(ref subpattern, _) => {
+ visitor.visit_pat(subpattern)
+ }
+ PatKind::Binding(_, _hir_id, ident, ref optional_subpattern) => {
+ visitor.visit_ident(ident);
+ walk_list!(visitor, visit_pat, optional_subpattern);
+ }
+ PatKind::Lit(ref expression) => visitor.visit_expr(expression),
+ PatKind::Range(ref lower_bound, ref upper_bound, _) => {
+ walk_list!(visitor, visit_expr, lower_bound);
+ walk_list!(visitor, visit_expr, upper_bound);
+ }
+ PatKind::Wild => (),
+ PatKind::Slice(prepatterns, ref slice_pattern, postpatterns) => {
+ walk_list!(visitor, visit_pat, prepatterns);
+ walk_list!(visitor, visit_pat, slice_pattern);
+ walk_list!(visitor, visit_pat, postpatterns);
+ }
+ }
+}
+
+pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V, foreign_item: &'v ForeignItem<'v>) {
+ visitor.visit_id(foreign_item.hir_id());
+ visitor.visit_ident(foreign_item.ident);
+
+ match foreign_item.kind {
+ ForeignItemKind::Fn(ref function_declaration, param_names, ref generics) => {
+ visitor.visit_generics(generics);
+ visitor.visit_fn_decl(function_declaration);
+ for &param_name in param_names {
+ visitor.visit_ident(param_name);
+ }
+ }
+ ForeignItemKind::Static(ref typ, _) => visitor.visit_ty(typ),
+ ForeignItemKind::Type => (),
+ }
+}
+
+pub fn walk_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v GenericBound<'v>) {
+ match *bound {
+ GenericBound::Trait(ref typ, modifier) => {
+ visitor.visit_poly_trait_ref(typ, modifier);
+ }
+ GenericBound::LangItemTrait(_, span, hir_id, args) => {
+ visitor.visit_id(hir_id);
+ visitor.visit_generic_args(span, args);
+ }
+ GenericBound::Outlives(ref lifetime) => visitor.visit_lifetime(lifetime),
+ }
+}
+
+pub fn walk_generic_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v GenericParam<'v>) {
+ visitor.visit_id(param.hir_id);
+ match param.name {
+ ParamName::Plain(ident) => visitor.visit_ident(ident),
+ ParamName::Error | ParamName::Fresh => {}
+ }
+ match param.kind {
+ GenericParamKind::Lifetime { .. } => {}
+ GenericParamKind::Type { ref default, .. } => walk_list!(visitor, visit_ty, default),
+ GenericParamKind::Const { ref ty, ref default } => {
+ visitor.visit_ty(ty);
+ if let Some(ref default) = default {
+ visitor.visit_const_param_default(param.hir_id, default);
+ }
+ }
+ }
+}
+
+pub fn walk_const_param_default<'v, V: Visitor<'v>>(visitor: &mut V, ct: &'v AnonConst) {
+ visitor.visit_anon_const(ct)
+}
+
+pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics<'v>) {
+ walk_list!(visitor, visit_generic_param, generics.params);
+ walk_list!(visitor, visit_where_predicate, generics.predicates);
+}
+
+pub fn walk_where_predicate<'v, V: Visitor<'v>>(
+ visitor: &mut V,
+ predicate: &'v WherePredicate<'v>,
+) {
+ match *predicate {
+ WherePredicate::BoundPredicate(WhereBoundPredicate {
+ ref bounded_ty,
+ bounds,
+ bound_generic_params,
+ ..
+ }) => {
+ visitor.visit_ty(bounded_ty);
+ walk_list!(visitor, visit_param_bound, bounds);
+ walk_list!(visitor, visit_generic_param, bound_generic_params);
+ }
+ WherePredicate::RegionPredicate(WhereRegionPredicate { ref lifetime, bounds, .. }) => {
+ visitor.visit_lifetime(lifetime);
+ walk_list!(visitor, visit_param_bound, bounds);
+ }
+ WherePredicate::EqPredicate(WhereEqPredicate {
+ hir_id, ref lhs_ty, ref rhs_ty, ..
+ }) => {
+ visitor.visit_id(hir_id);
+ visitor.visit_ty(lhs_ty);
+ visitor.visit_ty(rhs_ty);
+ }
+ }
+}
+
+pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FnRetTy<'v>) {
+ if let FnRetTy::Return(ref output_ty) = *ret_ty {
+ visitor.visit_ty(output_ty)
+ }
+}
+
+pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl<'v>) {
+ for ty in function_declaration.inputs {
+ visitor.visit_ty(ty)
+ }
+ walk_fn_ret_ty(visitor, &function_declaration.output)
+}
+
+pub fn walk_fn_kind<'v, V: Visitor<'v>>(visitor: &mut V, function_kind: FnKind<'v>) {
+ match function_kind {
+ FnKind::ItemFn(_, generics, ..) => {
+ visitor.visit_generics(generics);
+ }
+ FnKind::Closure | FnKind::Method(..) => {}
+ }
+}
+
+pub fn walk_fn<'v, V: Visitor<'v>>(
+ visitor: &mut V,
+ function_kind: FnKind<'v>,
+ function_declaration: &'v FnDecl<'v>,
+ body_id: BodyId,
+ _span: Span,
+ id: HirId,
+) {
+ visitor.visit_id(id);
+ visitor.visit_fn_decl(function_declaration);
+ walk_fn_kind(visitor, function_kind);
+ visitor.visit_nested_body(body_id)
+}
+
+pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem<'v>) {
+ // N.B., deliberately force a compilation error if/when new fields are added.
+ let TraitItem { ident, generics, ref defaultness, ref kind, span, def_id: _ } = *trait_item;
+ let hir_id = trait_item.hir_id();
+ visitor.visit_ident(ident);
+ visitor.visit_generics(&generics);
+ visitor.visit_defaultness(&defaultness);
+ match *kind {
+ TraitItemKind::Const(ref ty, default) => {
+ visitor.visit_id(hir_id);
+ visitor.visit_ty(ty);
+ walk_list!(visitor, visit_nested_body, default);
+ }
+ TraitItemKind::Fn(ref sig, TraitFn::Required(param_names)) => {
+ visitor.visit_id(hir_id);
+ visitor.visit_fn_decl(&sig.decl);
+ for &param_name in param_names {
+ visitor.visit_ident(param_name);
+ }
+ }
+ TraitItemKind::Fn(ref sig, TraitFn::Provided(body_id)) => {
+ visitor.visit_fn(FnKind::Method(ident, sig), &sig.decl, body_id, span, hir_id);
+ }
+ TraitItemKind::Type(bounds, ref default) => {
+ visitor.visit_id(hir_id);
+ walk_list!(visitor, visit_param_bound, bounds);
+ walk_list!(visitor, visit_ty, default);
+ }
+ }
+}
+
+pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref: &'v TraitItemRef) {
+ // N.B., deliberately force a compilation error if/when new fields are added.
+ let TraitItemRef { id, ident, ref kind, span: _ } = *trait_item_ref;
+ visitor.visit_nested_trait_item(id);
+ visitor.visit_ident(ident);
+ visitor.visit_associated_item_kind(kind);
+}
+
+pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem<'v>) {
+ // N.B., deliberately force a compilation error if/when new fields are added.
+ let ImplItem {
+ def_id: _,
+ ident,
+ ref generics,
+ ref kind,
+ ref defaultness,
+ span: _,
+ vis_span: _,
+ } = *impl_item;
+
+ visitor.visit_ident(ident);
+ visitor.visit_generics(generics);
+ visitor.visit_defaultness(defaultness);
+ match *kind {
+ ImplItemKind::Const(ref ty, body) => {
+ visitor.visit_id(impl_item.hir_id());
+ visitor.visit_ty(ty);
+ visitor.visit_nested_body(body);
+ }
+ ImplItemKind::Fn(ref sig, body_id) => {
+ visitor.visit_fn(
+ FnKind::Method(impl_item.ident, sig),
+ &sig.decl,
+ body_id,
+ impl_item.span,
+ impl_item.hir_id(),
+ );
+ }
+ ImplItemKind::TyAlias(ref ty) => {
+ visitor.visit_id(impl_item.hir_id());
+ visitor.visit_ty(ty);
+ }
+ }
+}
+
+pub fn walk_foreign_item_ref<'v, V: Visitor<'v>>(
+ visitor: &mut V,
+ foreign_item_ref: &'v ForeignItemRef,
+) {
+ // N.B., deliberately force a compilation error if/when new fields are added.
+ let ForeignItemRef { id, ident, span: _ } = *foreign_item_ref;
+ visitor.visit_nested_foreign_item(id);
+ visitor.visit_ident(ident);
+}
+
+pub fn walk_impl_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, impl_item_ref: &'v ImplItemRef) {
+ // N.B., deliberately force a compilation error if/when new fields are added.
+ let ImplItemRef { id, ident, ref kind, span: _, trait_item_def_id: _ } = *impl_item_ref;
+ visitor.visit_nested_impl_item(id);
+ visitor.visit_ident(ident);
+ visitor.visit_associated_item_kind(kind);
+}
+
+pub fn walk_struct_def<'v, V: Visitor<'v>>(
+ visitor: &mut V,
+ struct_definition: &'v VariantData<'v>,
+) {
+ walk_list!(visitor, visit_id, struct_definition.ctor_hir_id());
+ walk_list!(visitor, visit_field_def, struct_definition.fields());
+}
+
+pub fn walk_field_def<'v, V: Visitor<'v>>(visitor: &mut V, field: &'v FieldDef<'v>) {
+ visitor.visit_id(field.hir_id);
+ visitor.visit_ident(field.ident);
+ visitor.visit_ty(&field.ty);
+}
+
+pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block<'v>) {
+ visitor.visit_id(block.hir_id);
+ walk_list!(visitor, visit_stmt, block.stmts);
+ walk_list!(visitor, visit_expr, &block.expr);
+}
+
+pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt<'v>) {
+ visitor.visit_id(statement.hir_id);
+ match statement.kind {
+ StmtKind::Local(ref local) => visitor.visit_local(local),
+ StmtKind::Item(item) => visitor.visit_nested_item(item),
+ StmtKind::Expr(ref expression) | StmtKind::Semi(ref expression) => {
+ visitor.visit_expr(expression)
+ }
+ }
+}
+
+pub fn walk_array_len<'v, V: Visitor<'v>>(visitor: &mut V, len: &'v ArrayLen) {
+ match len {
+ &ArrayLen::Infer(hir_id, _span) => visitor.visit_id(hir_id),
+ ArrayLen::Body(c) => visitor.visit_anon_const(c),
+ }
+}
+
+pub fn walk_anon_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v AnonConst) {
+ visitor.visit_id(constant.hir_id);
+ visitor.visit_nested_body(constant.body);
+}
+
+pub fn walk_let_expr<'v, V: Visitor<'v>>(visitor: &mut V, let_expr: &'v Let<'v>) {
+ // match the visit order in walk_local
+ visitor.visit_expr(let_expr.init);
+ visitor.visit_id(let_expr.hir_id);
+ visitor.visit_pat(let_expr.pat);
+ walk_list!(visitor, visit_ty, let_expr.ty);
+}
+
+pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>) {
+ visitor.visit_id(expression.hir_id);
+ match expression.kind {
+ ExprKind::Box(ref subexpression) => visitor.visit_expr(subexpression),
+ ExprKind::Array(subexpressions) => {
+ walk_list!(visitor, visit_expr, subexpressions);
+ }
+ ExprKind::ConstBlock(ref anon_const) => visitor.visit_anon_const(anon_const),
+ ExprKind::Repeat(ref element, ref count) => {
+ visitor.visit_expr(element);
+ visitor.visit_array_length(count)
+ }
+ ExprKind::Struct(ref qpath, fields, ref optional_base) => {
+ visitor.visit_qpath(qpath, expression.hir_id, expression.span);
+ for field in fields {
+ visitor.visit_id(field.hir_id);
+ visitor.visit_ident(field.ident);
+ visitor.visit_expr(&field.expr)
+ }
+ walk_list!(visitor, visit_expr, optional_base);
+ }
+ ExprKind::Tup(subexpressions) => {
+ walk_list!(visitor, visit_expr, subexpressions);
+ }
+ ExprKind::Call(ref callee_expression, arguments) => {
+ visitor.visit_expr(callee_expression);
+ walk_list!(visitor, visit_expr, arguments);
+ }
+ ExprKind::MethodCall(ref segment, arguments, _) => {
+ visitor.visit_path_segment(expression.span, segment);
+ walk_list!(visitor, visit_expr, arguments);
+ }
+ ExprKind::Binary(_, ref left_expression, ref right_expression) => {
+ visitor.visit_expr(left_expression);
+ visitor.visit_expr(right_expression)
+ }
+ ExprKind::AddrOf(_, _, ref subexpression) | ExprKind::Unary(_, ref subexpression) => {
+ visitor.visit_expr(subexpression)
+ }
+ ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => {
+ visitor.visit_expr(subexpression);
+ visitor.visit_ty(typ)
+ }
+ ExprKind::DropTemps(ref subexpression) => {
+ visitor.visit_expr(subexpression);
+ }
+ ExprKind::Let(ref let_expr) => visitor.visit_let_expr(let_expr),
+ ExprKind::If(ref cond, ref then, ref else_opt) => {
+ visitor.visit_expr(cond);
+ visitor.visit_expr(then);
+ walk_list!(visitor, visit_expr, else_opt);
+ }
+ ExprKind::Loop(ref block, ref opt_label, _, _) => {
+ walk_list!(visitor, visit_label, opt_label);
+ visitor.visit_block(block);
+ }
+ ExprKind::Match(ref subexpression, arms, _) => {
+ visitor.visit_expr(subexpression);
+ walk_list!(visitor, visit_arm, arms);
+ }
+ ExprKind::Closure(&Closure {
+ binder: _,
+ bound_generic_params,
+ fn_decl,
+ body,
+ capture_clause: _,
+ fn_decl_span: _,
+ movability: _,
+ }) => {
+ walk_list!(visitor, visit_generic_param, bound_generic_params);
+ visitor.visit_fn(FnKind::Closure, fn_decl, body, expression.span, expression.hir_id)
+ }
+ ExprKind::Block(ref block, ref opt_label) => {
+ walk_list!(visitor, visit_label, opt_label);
+ visitor.visit_block(block);
+ }
+ ExprKind::Assign(ref lhs, ref rhs, _) => {
+ visitor.visit_expr(rhs);
+ visitor.visit_expr(lhs)
+ }
+ ExprKind::AssignOp(_, ref left_expression, ref right_expression) => {
+ visitor.visit_expr(right_expression);
+ visitor.visit_expr(left_expression);
+ }
+ ExprKind::Field(ref subexpression, ident) => {
+ visitor.visit_expr(subexpression);
+ visitor.visit_ident(ident);
+ }
+ ExprKind::Index(ref main_expression, ref index_expression) => {
+ visitor.visit_expr(main_expression);
+ visitor.visit_expr(index_expression)
+ }
+ ExprKind::Path(ref qpath) => {
+ visitor.visit_qpath(qpath, expression.hir_id, expression.span);
+ }
+ ExprKind::Break(ref destination, ref opt_expr) => {
+ walk_list!(visitor, visit_label, &destination.label);
+ walk_list!(visitor, visit_expr, opt_expr);
+ }
+ ExprKind::Continue(ref destination) => {
+ walk_list!(visitor, visit_label, &destination.label);
+ }
+ ExprKind::Ret(ref optional_expression) => {
+ walk_list!(visitor, visit_expr, optional_expression);
+ }
+ ExprKind::InlineAsm(ref asm) => {
+ visitor.visit_inline_asm(asm, expression.hir_id);
+ }
+ ExprKind::Yield(ref subexpression, _) => {
+ visitor.visit_expr(subexpression);
+ }
+ ExprKind::Lit(_) | ExprKind::Err => {}
+ }
+}
+
+pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm<'v>) {
+ visitor.visit_id(arm.hir_id);
+ visitor.visit_pat(&arm.pat);
+ if let Some(ref g) = arm.guard {
+ match g {
+ Guard::If(ref e) => visitor.visit_expr(e),
+ Guard::IfLet(ref l) => {
+ visitor.visit_let_expr(l);
+ }
+ }
+ }
+ visitor.visit_expr(&arm.body);
+}
+
+pub fn walk_associated_item_kind<'v, V: Visitor<'v>>(_: &mut V, _: &'v AssocItemKind) {
+ // No visitable content here: this fn exists so you can call it if
+ // the right thing to do, should content be added in the future,
+ // would be to walk it.
+}
+
+pub fn walk_defaultness<'v, V: Visitor<'v>>(_: &mut V, _: &'v Defaultness) {
+ // No visitable content here: this fn exists so you can call it if
+ // the right thing to do, should content be added in the future,
+ // would be to walk it.
+}
diff --git a/compiler/rustc_hir/src/lang_items.rs b/compiler/rustc_hir/src/lang_items.rs
new file mode 100644
index 000000000..c337be12a
--- /dev/null
+++ b/compiler/rustc_hir/src/lang_items.rs
@@ -0,0 +1,339 @@
+//! Defines language items.
+//!
+//! Language items are items that represent concepts intrinsic to the language
+//! itself. Examples are:
+//!
+//! * Traits that specify "kinds"; e.g., `Sync`, `Send`.
+//! * Traits that represent operators; e.g., `Add`, `Sub`, `Index`.
+//! * Functions called by the compiler itself.
+
+use crate::def_id::DefId;
+use crate::{MethodKind, Target};
+
+use rustc_ast as ast;
+use rustc_data_structures::fx::FxIndexMap;
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
+use rustc_macros::HashStable_Generic;
+use rustc_span::symbol::{kw, sym, Symbol};
+use rustc_span::Span;
+
+use std::sync::LazyLock;
+
+pub enum LangItemGroup {
+ Op,
+ Fn,
+}
+
+const NUM_GROUPS: usize = 2;
+
+macro_rules! expand_group {
+ () => {
+ None
+ };
+ ($group:expr) => {
+ Some($group)
+ };
+}
+
+// The actual lang items defined come at the end of this file in one handy table.
+// So you probably just want to nip down to the end.
+macro_rules! language_item_table {
+ (
+ $( $(#[$attr:meta])* $variant:ident $($group:expr)?, $module:ident :: $name:ident, $method:ident, $target:expr, $generics:expr; )*
+ ) => {
+
+ enum_from_u32! {
+ /// A representation of all the valid language items in Rust.
+ #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, Encodable, Decodable)]
+ pub enum LangItem {
+ $(
+ #[doc = concat!("The `", stringify!($name), "` lang item.")]
+ ///
+ $(#[$attr])*
+ $variant,
+ )*
+ }
+ }
+
+ impl LangItem {
+ /// Returns the `name` symbol in `#[lang = "$name"]`.
+ /// For example, [`LangItem::PartialEq`]`.name()`
+ /// would result in [`sym::eq`] since it is `#[lang = "eq"]`.
+ pub fn name(self) -> Symbol {
+ match self {
+ $( LangItem::$variant => $module::$name, )*
+ }
+ }
+
+ /// The [group](LangItemGroup) that this lang item belongs to,
+ /// or `None` if it doesn't belong to a group.
+ pub fn group(self) -> Option<LangItemGroup> {
+ use LangItemGroup::*;
+ match self {
+ $( LangItem::$variant => expand_group!($($group)*), )*
+ }
+ }
+
+ pub fn required_generics(&self) -> GenericRequirement {
+ match self {
+ $( LangItem::$variant => $generics, )*
+ }
+ }
+ }
+
+ /// All of the language items, defined or not.
+ /// Defined lang items can come from the current crate or its dependencies.
+ #[derive(HashStable_Generic, Debug)]
+ pub struct LanguageItems {
+ /// Mappings from lang items to their possibly found [`DefId`]s.
+ /// The index corresponds to the order in [`LangItem`].
+ pub items: Vec<Option<DefId>>,
+ /// Lang items that were not found during collection.
+ pub missing: Vec<LangItem>,
+ /// Mapping from [`LangItemGroup`] discriminants to all
+ /// [`DefId`]s of lang items in that group.
+ pub groups: [Vec<DefId>; NUM_GROUPS],
+ }
+
+ impl LanguageItems {
+ /// Construct an empty collection of lang items and no missing ones.
+ pub fn new() -> Self {
+ fn init_none(_: LangItem) -> Option<DefId> { None }
+ const EMPTY: Vec<DefId> = Vec::new();
+
+ Self {
+ items: vec![$(init_none(LangItem::$variant)),*],
+ missing: Vec::new(),
+ groups: [EMPTY; NUM_GROUPS],
+ }
+ }
+
+ /// Returns the mappings to the possibly found `DefId`s for each lang item.
+ pub fn items(&self) -> &[Option<DefId>] {
+ &*self.items
+ }
+
+ /// Requires that a given `LangItem` was bound and returns the corresponding `DefId`.
+ /// If it wasn't bound, e.g. due to a missing `#[lang = "<it.name()>"]`,
+ /// returns an error message as a string.
+ pub fn require(&self, it: LangItem) -> Result<DefId, String> {
+ self.items[it as usize].ok_or_else(|| format!("requires `{}` lang_item", it.name()))
+ }
+
+ /// Returns the [`DefId`]s of all lang items in a group.
+ pub fn group(&self, group: LangItemGroup) -> &[DefId] {
+ self.groups[group as usize].as_ref()
+ }
+
+ $(
+ #[doc = concat!("Returns the [`DefId`] of the `", stringify!($name), "` lang item if it is defined.")]
+ pub fn $method(&self) -> Option<DefId> {
+ self.items[LangItem::$variant as usize]
+ }
+ )*
+ }
+
+ /// A mapping from the name of the lang item to its order and the form it must be of.
+ pub static ITEM_REFS: LazyLock<FxIndexMap<Symbol, (usize, Target)>> = LazyLock::new(|| {
+ let mut item_refs = FxIndexMap::default();
+ $( item_refs.insert($module::$name, (LangItem::$variant as usize, $target)); )*
+ item_refs
+ });
+
+// End of the macro
+ }
+}
+
+impl<CTX> HashStable<CTX> for LangItem {
+ fn hash_stable(&self, _: &mut CTX, hasher: &mut StableHasher) {
+ ::std::hash::Hash::hash(self, hasher);
+ }
+}
+
+/// Extracts the first `lang = "$name"` out of a list of attributes.
+/// The attributes `#[panic_handler]` and `#[alloc_error_handler]`
+/// are also extracted out when found.
+pub fn extract(attrs: &[ast::Attribute]) -> Option<(Symbol, Span)> {
+ attrs.iter().find_map(|attr| {
+ Some(match attr {
+ _ if attr.has_name(sym::lang) => (attr.value_str()?, attr.span),
+ _ if attr.has_name(sym::panic_handler) => (sym::panic_impl, attr.span),
+ _ if attr.has_name(sym::alloc_error_handler) => (sym::oom, attr.span),
+ _ => return None,
+ })
+ })
+}
+
+language_item_table! {
+// Variant name, Name, Method name, Target Generic requirements;
+ Sized, sym::sized, sized_trait, Target::Trait, GenericRequirement::Exact(0);
+ Unsize, sym::unsize, unsize_trait, Target::Trait, GenericRequirement::Minimum(1);
+ /// Trait injected by `#[derive(PartialEq)]`, (i.e. "Partial EQ").
+ StructuralPeq, sym::structural_peq, structural_peq_trait, Target::Trait, GenericRequirement::None;
+ /// Trait injected by `#[derive(Eq)]`, (i.e. "Total EQ"; no, I will not apologize).
+ StructuralTeq, sym::structural_teq, structural_teq_trait, Target::Trait, GenericRequirement::None;
+ Copy, sym::copy, copy_trait, Target::Trait, GenericRequirement::Exact(0);
+ Clone, sym::clone, clone_trait, Target::Trait, GenericRequirement::None;
+ Sync, sym::sync, sync_trait, Target::Trait, GenericRequirement::Exact(0);
+ DiscriminantKind, sym::discriminant_kind, discriminant_kind_trait, Target::Trait, GenericRequirement::None;
+ /// The associated item of the [`DiscriminantKind`] trait.
+ Discriminant, sym::discriminant_type, discriminant_type, Target::AssocTy, GenericRequirement::None;
+
+ PointeeTrait, sym::pointee_trait, pointee_trait, Target::Trait, GenericRequirement::None;
+ Metadata, sym::metadata_type, metadata_type, Target::AssocTy, GenericRequirement::None;
+ DynMetadata, sym::dyn_metadata, dyn_metadata, Target::Struct, GenericRequirement::None;
+
+ Freeze, sym::freeze, freeze_trait, Target::Trait, GenericRequirement::Exact(0);
+
+ Drop, sym::drop, drop_trait, Target::Trait, GenericRequirement::None;
+ Destruct, sym::destruct, destruct_trait, Target::Trait, GenericRequirement::None;
+
+ CoerceUnsized, sym::coerce_unsized, coerce_unsized_trait, Target::Trait, GenericRequirement::Minimum(1);
+ DispatchFromDyn, sym::dispatch_from_dyn, dispatch_from_dyn_trait, Target::Trait, GenericRequirement::Minimum(1);
+
+ // language items relating to transmutability
+ TransmuteTrait, sym::transmute_trait, transmute_trait, Target::Trait, GenericRequirement::Exact(6);
+
+ Add(Op), sym::add, add_trait, Target::Trait, GenericRequirement::Exact(1);
+ Sub(Op), sym::sub, sub_trait, Target::Trait, GenericRequirement::Exact(1);
+ Mul(Op), sym::mul, mul_trait, Target::Trait, GenericRequirement::Exact(1);
+ Div(Op), sym::div, div_trait, Target::Trait, GenericRequirement::Exact(1);
+ Rem(Op), sym::rem, rem_trait, Target::Trait, GenericRequirement::Exact(1);
+ Neg(Op), sym::neg, neg_trait, Target::Trait, GenericRequirement::Exact(0);
+ Not(Op), sym::not, not_trait, Target::Trait, GenericRequirement::Exact(0);
+ BitXor(Op), sym::bitxor, bitxor_trait, Target::Trait, GenericRequirement::Exact(1);
+ BitAnd(Op), sym::bitand, bitand_trait, Target::Trait, GenericRequirement::Exact(1);
+ BitOr(Op), sym::bitor, bitor_trait, Target::Trait, GenericRequirement::Exact(1);
+ Shl(Op), sym::shl, shl_trait, Target::Trait, GenericRequirement::Exact(1);
+ Shr(Op), sym::shr, shr_trait, Target::Trait, GenericRequirement::Exact(1);
+ AddAssign(Op), sym::add_assign, add_assign_trait, Target::Trait, GenericRequirement::Exact(1);
+ SubAssign(Op), sym::sub_assign, sub_assign_trait, Target::Trait, GenericRequirement::Exact(1);
+ MulAssign(Op), sym::mul_assign, mul_assign_trait, Target::Trait, GenericRequirement::Exact(1);
+ DivAssign(Op), sym::div_assign, div_assign_trait, Target::Trait, GenericRequirement::Exact(1);
+ RemAssign(Op), sym::rem_assign, rem_assign_trait, Target::Trait, GenericRequirement::Exact(1);
+ BitXorAssign(Op), sym::bitxor_assign, bitxor_assign_trait, Target::Trait, GenericRequirement::Exact(1);
+ BitAndAssign(Op), sym::bitand_assign, bitand_assign_trait, Target::Trait, GenericRequirement::Exact(1);
+ BitOrAssign(Op), sym::bitor_assign, bitor_assign_trait, Target::Trait, GenericRequirement::Exact(1);
+ ShlAssign(Op), sym::shl_assign, shl_assign_trait, Target::Trait, GenericRequirement::Exact(1);
+ ShrAssign(Op), sym::shr_assign, shr_assign_trait, Target::Trait, GenericRequirement::Exact(1);
+ Index(Op), sym::index, index_trait, Target::Trait, GenericRequirement::Exact(1);
+ IndexMut(Op), sym::index_mut, index_mut_trait, Target::Trait, GenericRequirement::Exact(1);
+
+ UnsafeCell, sym::unsafe_cell, unsafe_cell_type, Target::Struct, GenericRequirement::None;
+ VaList, sym::va_list, va_list, Target::Struct, GenericRequirement::None;
+
+ Deref, sym::deref, deref_trait, Target::Trait, GenericRequirement::Exact(0);
+ DerefMut, sym::deref_mut, deref_mut_trait, Target::Trait, GenericRequirement::Exact(0);
+ DerefTarget, sym::deref_target, deref_target, Target::AssocTy, GenericRequirement::None;
+ Receiver, sym::receiver, receiver_trait, Target::Trait, GenericRequirement::None;
+
+ Fn(Fn), kw::Fn, fn_trait, Target::Trait, GenericRequirement::Exact(1);
+ FnMut(Fn), sym::fn_mut, fn_mut_trait, Target::Trait, GenericRequirement::Exact(1);
+ FnOnce(Fn), sym::fn_once, fn_once_trait, Target::Trait, GenericRequirement::Exact(1);
+
+ FnOnceOutput, sym::fn_once_output, fn_once_output, Target::AssocTy, GenericRequirement::None;
+
+ Future, sym::future_trait, future_trait, Target::Trait, GenericRequirement::Exact(0);
+ GeneratorState, sym::generator_state, gen_state, Target::Enum, GenericRequirement::None;
+ Generator, sym::generator, gen_trait, Target::Trait, GenericRequirement::Minimum(1);
+ GeneratorReturn, sym::generator_return, generator_return, Target::AssocTy, GenericRequirement::None;
+ Unpin, sym::unpin, unpin_trait, Target::Trait, GenericRequirement::None;
+ Pin, sym::pin, pin_type, Target::Struct, GenericRequirement::None;
+
+ PartialEq(Op), sym::eq, eq_trait, Target::Trait, GenericRequirement::Exact(1);
+ PartialOrd(Op), sym::partial_ord, partial_ord_trait, Target::Trait, GenericRequirement::Exact(1);
+
+ // A number of panic-related lang items. The `panic` item corresponds to divide-by-zero and
+ // various panic cases with `match`. The `panic_bounds_check` item is for indexing arrays.
+ //
+ // The `begin_unwind` lang item has a predefined symbol name and is sort of a "weak lang item"
+ // in the sense that a crate is not required to have it defined to use it, but a final product
+ // is required to define it somewhere. Additionally, there are restrictions on crates that use
+ // a weak lang item, but do not have it defined.
+ Panic, sym::panic, panic_fn, Target::Fn, GenericRequirement::Exact(0);
+ PanicFmt, sym::panic_fmt, panic_fmt, Target::Fn, GenericRequirement::None;
+ PanicDisplay, sym::panic_display, panic_display, Target::Fn, GenericRequirement::None;
+ ConstPanicFmt, sym::const_panic_fmt, const_panic_fmt, Target::Fn, GenericRequirement::None;
+ PanicBoundsCheck, sym::panic_bounds_check, panic_bounds_check_fn, Target::Fn, GenericRequirement::Exact(0);
+ PanicInfo, sym::panic_info, panic_info, Target::Struct, GenericRequirement::None;
+ PanicLocation, sym::panic_location, panic_location, Target::Struct, GenericRequirement::None;
+ PanicImpl, sym::panic_impl, panic_impl, Target::Fn, GenericRequirement::None;
+ PanicNoUnwind, sym::panic_no_unwind, panic_no_unwind, Target::Fn, GenericRequirement::Exact(0);
+ /// libstd panic entry point. Necessary for const eval to be able to catch it
+ BeginPanic, sym::begin_panic, begin_panic_fn, Target::Fn, GenericRequirement::None;
+
+ ExchangeMalloc, sym::exchange_malloc, exchange_malloc_fn, Target::Fn, GenericRequirement::None;
+ BoxFree, sym::box_free, box_free_fn, Target::Fn, GenericRequirement::Minimum(1);
+ DropInPlace, sym::drop_in_place, drop_in_place_fn, Target::Fn, GenericRequirement::Minimum(1);
+ Oom, sym::oom, oom, Target::Fn, GenericRequirement::None;
+ AllocLayout, sym::alloc_layout, alloc_layout, Target::Struct, GenericRequirement::None;
+ ConstEvalSelect, sym::const_eval_select, const_eval_select, Target::Fn, GenericRequirement::Exact(4);
+ ConstConstEvalSelect, sym::const_eval_select_ct,const_eval_select_ct, Target::Fn, GenericRequirement::Exact(4);
+
+ Start, sym::start, start_fn, Target::Fn, GenericRequirement::Exact(1);
+
+ EhPersonality, sym::eh_personality, eh_personality, Target::Fn, GenericRequirement::None;
+ EhCatchTypeinfo, sym::eh_catch_typeinfo, eh_catch_typeinfo, Target::Static, GenericRequirement::None;
+
+ OwnedBox, sym::owned_box, owned_box, Target::Struct, GenericRequirement::Minimum(1);
+
+ PhantomData, sym::phantom_data, phantom_data, Target::Struct, GenericRequirement::Exact(1);
+
+ ManuallyDrop, sym::manually_drop, manually_drop, Target::Struct, GenericRequirement::None;
+
+ MaybeUninit, sym::maybe_uninit, maybe_uninit, Target::Union, GenericRequirement::None;
+
+ /// Align offset for stride != 1; must not panic.
+ AlignOffset, sym::align_offset, align_offset_fn, Target::Fn, GenericRequirement::None;
+
+ Termination, sym::termination, termination, Target::Trait, GenericRequirement::None;
+
+ Try, sym::Try, try_trait, Target::Trait, GenericRequirement::None;
+
+ SliceLen, sym::slice_len_fn, slice_len_fn, Target::Method(MethodKind::Inherent), GenericRequirement::None;
+
+ // Language items from AST lowering
+ TryTraitFromResidual, sym::from_residual, from_residual_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
+ TryTraitFromOutput, sym::from_output, from_output_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
+ TryTraitBranch, sym::branch, branch_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
+ TryTraitFromYeet, sym::from_yeet, from_yeet_fn, Target::Fn, GenericRequirement::None;
+
+ PollReady, sym::Ready, poll_ready_variant, Target::Variant, GenericRequirement::None;
+ PollPending, sym::Pending, poll_pending_variant, Target::Variant, GenericRequirement::None;
+
+ FromGenerator, sym::from_generator, from_generator_fn, Target::Fn, GenericRequirement::None;
+ GetContext, sym::get_context, get_context_fn, Target::Fn, GenericRequirement::None;
+
+ FuturePoll, sym::poll, future_poll_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
+
+ FromFrom, sym::from, from_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
+
+ OptionSome, sym::Some, option_some_variant, Target::Variant, GenericRequirement::None;
+ OptionNone, sym::None, option_none_variant, Target::Variant, GenericRequirement::None;
+
+ ResultOk, sym::Ok, result_ok_variant, Target::Variant, GenericRequirement::None;
+ ResultErr, sym::Err, result_err_variant, Target::Variant, GenericRequirement::None;
+
+ ControlFlowContinue, sym::Continue, cf_continue_variant, Target::Variant, GenericRequirement::None;
+ ControlFlowBreak, sym::Break, cf_break_variant, Target::Variant, GenericRequirement::None;
+
+ IntoFutureIntoFuture, sym::into_future, into_future_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
+ IntoIterIntoIter, sym::into_iter, into_iter_fn, Target::Method(MethodKind::Trait { body: false }), GenericRequirement::None;
+ IteratorNext, sym::next, next_fn, Target::Method(MethodKind::Trait { body: false}), GenericRequirement::None;
+
+ PinNewUnchecked, sym::new_unchecked, new_unchecked_fn, Target::Method(MethodKind::Inherent), GenericRequirement::None;
+
+ RangeFrom, sym::RangeFrom, range_from_struct, Target::Struct, GenericRequirement::None;
+ RangeFull, sym::RangeFull, range_full_struct, Target::Struct, GenericRequirement::None;
+ RangeInclusiveStruct, sym::RangeInclusive, range_inclusive_struct, Target::Struct, GenericRequirement::None;
+ RangeInclusiveNew, sym::range_inclusive_new, range_inclusive_new_method, Target::Method(MethodKind::Inherent), GenericRequirement::None;
+ Range, sym::Range, range_struct, Target::Struct, GenericRequirement::None;
+ RangeToInclusive, sym::RangeToInclusive, range_to_inclusive_struct, Target::Struct, GenericRequirement::None;
+ RangeTo, sym::RangeTo, range_to_struct, Target::Struct, GenericRequirement::None;
+}
+
+pub enum GenericRequirement {
+ None,
+ Minimum(usize),
+ Exact(usize),
+}
diff --git a/compiler/rustc_hir/src/lib.rs b/compiler/rustc_hir/src/lib.rs
new file mode 100644
index 000000000..0f9e6fa7b
--- /dev/null
+++ b/compiler/rustc_hir/src/lib.rs
@@ -0,0 +1,47 @@
+//! HIR datatypes. See the [rustc dev guide] for more info.
+//!
+//! [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/hir.html
+
+#![feature(associated_type_defaults)]
+#![feature(closure_track_caller)]
+#![feature(const_btree_new)]
+#![feature(let_else)]
+#![feature(once_cell)]
+#![feature(min_specialization)]
+#![feature(never_type)]
+#![feature(rustc_attrs)]
+#![recursion_limit = "256"]
+
+#[macro_use]
+extern crate rustc_macros;
+
+#[macro_use]
+extern crate rustc_data_structures;
+
+extern crate self as rustc_hir;
+
+mod arena;
+pub mod def;
+pub mod def_path_hash_map;
+pub mod definitions;
+pub mod diagnostic_items;
+pub use rustc_span::def_id;
+mod hir;
+pub mod hir_id;
+pub mod intravisit;
+pub mod lang_items;
+pub mod pat_util;
+mod stable_hash_impls;
+mod target;
+pub mod weak_lang_items;
+
+#[cfg(test)]
+mod tests;
+
+pub use hir::*;
+pub use hir_id::*;
+pub use lang_items::{LangItem, LanguageItems};
+pub use stable_hash_impls::HashStableContext;
+pub use target::{MethodKind, Target};
+
+arena_types!(rustc_arena::declare_arena);
diff --git a/compiler/rustc_hir/src/pat_util.rs b/compiler/rustc_hir/src/pat_util.rs
new file mode 100644
index 000000000..93112199b
--- /dev/null
+++ b/compiler/rustc_hir/src/pat_util.rs
@@ -0,0 +1,157 @@
+use crate::def::{CtorOf, DefKind, Res};
+use crate::def_id::DefId;
+use crate::hir::{self, HirId, PatKind};
+use rustc_data_structures::fx::FxHashSet;
+use rustc_span::hygiene::DesugaringKind;
+use rustc_span::symbol::Ident;
+use rustc_span::Span;
+
+use std::iter::{Enumerate, ExactSizeIterator};
+
+pub struct EnumerateAndAdjust<I> {
+ enumerate: Enumerate<I>,
+ gap_pos: usize,
+ gap_len: usize,
+}
+
+impl<I> Iterator for EnumerateAndAdjust<I>
+where
+ I: Iterator,
+{
+ type Item = (usize, <I as Iterator>::Item);
+
+ fn next(&mut self) -> Option<(usize, <I as Iterator>::Item)> {
+ self.enumerate
+ .next()
+ .map(|(i, elem)| (if i < self.gap_pos { i } else { i + self.gap_len }, elem))
+ }
+
+ fn size_hint(&self) -> (usize, Option<usize>) {
+ self.enumerate.size_hint()
+ }
+}
+
+pub trait EnumerateAndAdjustIterator {
+ fn enumerate_and_adjust(
+ self,
+ expected_len: usize,
+ gap_pos: Option<usize>,
+ ) -> EnumerateAndAdjust<Self>
+ where
+ Self: Sized;
+}
+
+impl<T: ExactSizeIterator> EnumerateAndAdjustIterator for T {
+ fn enumerate_and_adjust(
+ self,
+ expected_len: usize,
+ gap_pos: Option<usize>,
+ ) -> EnumerateAndAdjust<Self>
+ where
+ Self: Sized,
+ {
+ let actual_len = self.len();
+ EnumerateAndAdjust {
+ enumerate: self.enumerate(),
+ gap_pos: gap_pos.unwrap_or(expected_len),
+ gap_len: expected_len - actual_len,
+ }
+ }
+}
+
+impl hir::Pat<'_> {
+ /// Call `f` on every "binding" in a pattern, e.g., on `a` in
+ /// `match foo() { Some(a) => (), None => () }`
+ pub fn each_binding(&self, mut f: impl FnMut(hir::BindingAnnotation, HirId, Span, Ident)) {
+ self.walk_always(|p| {
+ if let PatKind::Binding(binding_mode, _, ident, _) = p.kind {
+ f(binding_mode, p.hir_id, p.span, ident);
+ }
+ });
+ }
+
+ /// Call `f` on every "binding" in a pattern, e.g., on `a` in
+ /// `match foo() { Some(a) => (), None => () }`.
+ ///
+ /// When encountering an or-pattern `p_0 | ... | p_n` only `p_0` will be visited.
+ pub fn each_binding_or_first(
+ &self,
+ f: &mut impl FnMut(hir::BindingAnnotation, HirId, Span, Ident),
+ ) {
+ self.walk(|p| match &p.kind {
+ PatKind::Or(ps) => {
+ ps[0].each_binding_or_first(f);
+ false
+ }
+ PatKind::Binding(bm, _, ident, _) => {
+ f(*bm, p.hir_id, p.span, *ident);
+ true
+ }
+ _ => true,
+ })
+ }
+
+ pub fn simple_ident(&self) -> Option<Ident> {
+ match self.kind {
+ PatKind::Binding(
+ hir::BindingAnnotation::Unannotated | hir::BindingAnnotation::Mutable,
+ _,
+ ident,
+ None,
+ ) => Some(ident),
+ _ => None,
+ }
+ }
+
+ /// Returns variants that are necessary to exist for the pattern to match.
+ pub fn necessary_variants(&self) -> Vec<DefId> {
+ let mut variants = vec![];
+ self.walk(|p| match &p.kind {
+ PatKind::Or(_) => false,
+ PatKind::Path(hir::QPath::Resolved(_, path))
+ | PatKind::TupleStruct(hir::QPath::Resolved(_, path), ..)
+ | PatKind::Struct(hir::QPath::Resolved(_, path), ..) => {
+ if let Res::Def(DefKind::Variant | DefKind::Ctor(CtorOf::Variant, ..), id) =
+ path.res
+ {
+ variants.push(id);
+ }
+ true
+ }
+ _ => true,
+ });
+ // We remove duplicates by inserting into a `FxHashSet` to avoid re-ordering
+ // the bounds
+ let mut duplicates = FxHashSet::default();
+ variants.retain(|def_id| duplicates.insert(*def_id));
+ variants
+ }
+
+ /// Checks if the pattern contains any `ref` or `ref mut` bindings, and if
+ /// yes whether it contains mutable or just immutables ones.
+ //
+ // FIXME(tschottdorf): this is problematic as the HIR is being scraped, but
+ // ref bindings are be implicit after #42640 (default match binding modes). See issue #44848.
+ pub fn contains_explicit_ref_binding(&self) -> Option<hir::Mutability> {
+ let mut result = None;
+ self.each_binding(|annotation, _, _, _| match annotation {
+ hir::BindingAnnotation::Ref => match result {
+ None | Some(hir::Mutability::Not) => result = Some(hir::Mutability::Not),
+ _ => {}
+ },
+ hir::BindingAnnotation::RefMut => result = Some(hir::Mutability::Mut),
+ _ => {}
+ });
+ result
+ }
+
+ /// If the pattern is `Some(<pat>)` from a desugared for loop, returns the inner pattern
+ pub fn for_loop_some(&self) -> Option<&Self> {
+ if self.span.desugaring_kind() == Some(DesugaringKind::ForLoop) {
+ if let hir::PatKind::Struct(_, [pat_field], _) = self.kind {
+ return Some(pat_field.pat);
+ }
+ }
+ None
+ }
+}
diff --git a/compiler/rustc_hir/src/stable_hash_impls.rs b/compiler/rustc_hir/src/stable_hash_impls.rs
new file mode 100644
index 000000000..8ccd59e8e
--- /dev/null
+++ b/compiler/rustc_hir/src/stable_hash_impls.rs
@@ -0,0 +1,143 @@
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher, ToStableHashKey};
+
+use crate::hir::{
+ AttributeMap, BodyId, Crate, Expr, ForeignItemId, ImplItemId, ItemId, OwnerNodes, TraitItemId,
+ Ty,
+};
+use crate::hir_id::{HirId, ItemLocalId};
+use rustc_span::def_id::DefPathHash;
+
+/// Requirements for a `StableHashingContext` to be used in this crate.
+/// This is a hack to allow using the `HashStable_Generic` derive macro
+/// instead of implementing everything in `rustc_middle`.
+pub trait HashStableContext:
+ rustc_ast::HashStableContext + rustc_target::HashStableContext
+{
+ fn hash_body_id(&mut self, _: BodyId, hasher: &mut StableHasher);
+ fn hash_hir_expr(&mut self, _: &Expr<'_>, hasher: &mut StableHasher);
+ fn hash_hir_ty(&mut self, _: &Ty<'_>, hasher: &mut StableHasher);
+}
+
+impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for HirId {
+ type KeyType = (DefPathHash, ItemLocalId);
+
+ #[inline]
+ fn to_stable_hash_key(&self, hcx: &HirCtx) -> (DefPathHash, ItemLocalId) {
+ let def_path_hash = self.owner.to_stable_hash_key(hcx);
+ (def_path_hash, self.local_id)
+ }
+}
+
+impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for ItemLocalId {
+ type KeyType = ItemLocalId;
+
+ #[inline]
+ fn to_stable_hash_key(&self, _: &HirCtx) -> ItemLocalId {
+ *self
+ }
+}
+
+impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for BodyId {
+ type KeyType = (DefPathHash, ItemLocalId);
+
+ #[inline]
+ fn to_stable_hash_key(&self, hcx: &HirCtx) -> (DefPathHash, ItemLocalId) {
+ let BodyId { hir_id } = *self;
+ hir_id.to_stable_hash_key(hcx)
+ }
+}
+
+impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for ItemId {
+ type KeyType = DefPathHash;
+
+ #[inline]
+ fn to_stable_hash_key(&self, hcx: &HirCtx) -> DefPathHash {
+ self.def_id.to_stable_hash_key(hcx)
+ }
+}
+
+impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for TraitItemId {
+ type KeyType = DefPathHash;
+
+ #[inline]
+ fn to_stable_hash_key(&self, hcx: &HirCtx) -> DefPathHash {
+ self.def_id.to_stable_hash_key(hcx)
+ }
+}
+
+impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for ImplItemId {
+ type KeyType = DefPathHash;
+
+ #[inline]
+ fn to_stable_hash_key(&self, hcx: &HirCtx) -> DefPathHash {
+ self.def_id.to_stable_hash_key(hcx)
+ }
+}
+
+impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for ForeignItemId {
+ type KeyType = DefPathHash;
+
+ #[inline]
+ fn to_stable_hash_key(&self, hcx: &HirCtx) -> DefPathHash {
+ self.def_id.to_stable_hash_key(hcx)
+ }
+}
+
+impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for BodyId {
+ fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
+ hcx.hash_body_id(*self, hasher)
+ }
+}
+
+// The following implementations of HashStable for `ItemId`, `TraitItemId`, and
+// `ImplItemId` deserve special attention. Normally we do not hash `NodeId`s within
+// the HIR, since they just signify a HIR nodes own path. But `ItemId` et al
+// are used when another item in the HIR is *referenced* and we certainly
+// want to pick up on a reference changing its target, so we hash the NodeIds
+// in "DefPath Mode".
+
+impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for Expr<'_> {
+ fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
+ hcx.hash_hir_expr(self, hasher)
+ }
+}
+
+impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for Ty<'_> {
+ fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
+ hcx.hash_hir_ty(self, hasher)
+ }
+}
+
+impl<'tcx, HirCtx: crate::HashStableContext> HashStable<HirCtx> for OwnerNodes<'tcx> {
+ fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
+ // We ignore the `nodes` and `bodies` fields since these refer to information included in
+ // `hash` which is hashed in the collector and used for the crate hash.
+ // `local_id_to_def_id` is also ignored because is dependent on the body, then just hashing
+ // the body satisfies the condition of two nodes being different have different
+ // `hash_stable` results.
+ let OwnerNodes {
+ hash_including_bodies,
+ hash_without_bodies: _,
+ nodes: _,
+ bodies: _,
+ local_id_to_def_id: _,
+ } = *self;
+ hash_including_bodies.hash_stable(hcx, hasher);
+ }
+}
+
+impl<'tcx, HirCtx: crate::HashStableContext> HashStable<HirCtx> for AttributeMap<'tcx> {
+ fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
+ // We ignore the `map` since it refers to information included in `hash` which is hashed in
+ // the collector and used for the crate hash.
+ let AttributeMap { hash, map: _ } = *self;
+ hash.hash_stable(hcx, hasher);
+ }
+}
+
+impl<HirCtx: crate::HashStableContext> HashStable<HirCtx> for Crate<'_> {
+ fn hash_stable(&self, hcx: &mut HirCtx, hasher: &mut StableHasher) {
+ let Crate { owners: _, hir_hash } = self;
+ hir_hash.hash_stable(hcx, hasher)
+ }
+}
diff --git a/compiler/rustc_hir/src/target.rs b/compiler/rustc_hir/src/target.rs
new file mode 100644
index 000000000..6236dea10
--- /dev/null
+++ b/compiler/rustc_hir/src/target.rs
@@ -0,0 +1,188 @@
+//! This module implements some validity checks for attributes.
+//! In particular it verifies that `#[inline]` and `#[repr]` attributes are
+//! attached to items that actually support them and if there are
+//! conflicts between multiple such attributes attached to the same
+//! item.
+
+use crate::hir;
+use crate::{Item, ItemKind, TraitItem, TraitItemKind};
+
+use crate::def::DefKind;
+use std::fmt::{self, Display};
+
+#[derive(Copy, Clone, PartialEq, Debug)]
+pub enum GenericParamKind {
+ Type,
+ Lifetime,
+ Const,
+}
+
+#[derive(Copy, Clone, PartialEq, Debug)]
+pub enum MethodKind {
+ Trait { body: bool },
+ Inherent,
+}
+
+#[derive(Copy, Clone, PartialEq, Debug)]
+pub enum Target {
+ ExternCrate,
+ Use,
+ Static,
+ Const,
+ Fn,
+ Closure,
+ Mod,
+ ForeignMod,
+ GlobalAsm,
+ TyAlias,
+ OpaqueTy,
+ Enum,
+ Variant,
+ Struct,
+ Field,
+ Union,
+ Trait,
+ TraitAlias,
+ Impl,
+ Expression,
+ Statement,
+ Arm,
+ AssocConst,
+ Method(MethodKind),
+ AssocTy,
+ ForeignFn,
+ ForeignStatic,
+ ForeignTy,
+ GenericParam(GenericParamKind),
+ MacroDef,
+ Param,
+}
+
+impl Display for Target {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ write!(f, "{}", Self::name(*self))
+ }
+}
+
+impl Target {
+ pub fn from_item(item: &Item<'_>) -> Target {
+ match item.kind {
+ ItemKind::ExternCrate(..) => Target::ExternCrate,
+ ItemKind::Use(..) => Target::Use,
+ ItemKind::Static(..) => Target::Static,
+ ItemKind::Const(..) => Target::Const,
+ ItemKind::Fn(..) => Target::Fn,
+ ItemKind::Macro(..) => Target::MacroDef,
+ ItemKind::Mod(..) => Target::Mod,
+ ItemKind::ForeignMod { .. } => Target::ForeignMod,
+ ItemKind::GlobalAsm(..) => Target::GlobalAsm,
+ ItemKind::TyAlias(..) => Target::TyAlias,
+ ItemKind::OpaqueTy(..) => Target::OpaqueTy,
+ ItemKind::Enum(..) => Target::Enum,
+ ItemKind::Struct(..) => Target::Struct,
+ ItemKind::Union(..) => Target::Union,
+ ItemKind::Trait(..) => Target::Trait,
+ ItemKind::TraitAlias(..) => Target::TraitAlias,
+ ItemKind::Impl { .. } => Target::Impl,
+ }
+ }
+
+ // FIXME: For now, should only be used with def_kinds from ItemIds
+ pub fn from_def_kind(def_kind: DefKind) -> Target {
+ match def_kind {
+ DefKind::ExternCrate => Target::ExternCrate,
+ DefKind::Use => Target::Use,
+ DefKind::Static(..) => Target::Static,
+ DefKind::Const => Target::Const,
+ DefKind::Fn => Target::Fn,
+ DefKind::Macro(..) => Target::MacroDef,
+ DefKind::Mod => Target::Mod,
+ DefKind::ForeignMod => Target::ForeignMod,
+ DefKind::GlobalAsm => Target::GlobalAsm,
+ DefKind::TyAlias => Target::TyAlias,
+ DefKind::OpaqueTy => Target::OpaqueTy,
+ DefKind::Enum => Target::Enum,
+ DefKind::Struct => Target::Struct,
+ DefKind::Union => Target::Union,
+ DefKind::Trait => Target::Trait,
+ DefKind::TraitAlias => Target::TraitAlias,
+ DefKind::Impl => Target::Impl,
+ _ => panic!("impossible case reached"),
+ }
+ }
+
+ pub fn from_trait_item(trait_item: &TraitItem<'_>) -> Target {
+ match trait_item.kind {
+ TraitItemKind::Const(..) => Target::AssocConst,
+ TraitItemKind::Fn(_, hir::TraitFn::Required(_)) => {
+ Target::Method(MethodKind::Trait { body: false })
+ }
+ TraitItemKind::Fn(_, hir::TraitFn::Provided(_)) => {
+ Target::Method(MethodKind::Trait { body: true })
+ }
+ TraitItemKind::Type(..) => Target::AssocTy,
+ }
+ }
+
+ pub fn from_foreign_item(foreign_item: &hir::ForeignItem<'_>) -> Target {
+ match foreign_item.kind {
+ hir::ForeignItemKind::Fn(..) => Target::ForeignFn,
+ hir::ForeignItemKind::Static(..) => Target::ForeignStatic,
+ hir::ForeignItemKind::Type => Target::ForeignTy,
+ }
+ }
+
+ pub fn from_generic_param(generic_param: &hir::GenericParam<'_>) -> Target {
+ match generic_param.kind {
+ hir::GenericParamKind::Type { .. } => Target::GenericParam(GenericParamKind::Type),
+ hir::GenericParamKind::Lifetime { .. } => {
+ Target::GenericParam(GenericParamKind::Lifetime)
+ }
+ hir::GenericParamKind::Const { .. } => Target::GenericParam(GenericParamKind::Const),
+ }
+ }
+
+ pub fn name(self) -> &'static str {
+ match self {
+ Target::ExternCrate => "extern crate",
+ Target::Use => "use",
+ Target::Static => "static item",
+ Target::Const => "constant item",
+ Target::Fn => "function",
+ Target::Closure => "closure",
+ Target::Mod => "module",
+ Target::ForeignMod => "foreign module",
+ Target::GlobalAsm => "global asm",
+ Target::TyAlias => "type alias",
+ Target::OpaqueTy => "opaque type",
+ Target::Enum => "enum",
+ Target::Variant => "enum variant",
+ Target::Struct => "struct",
+ Target::Field => "struct field",
+ Target::Union => "union",
+ Target::Trait => "trait",
+ Target::TraitAlias => "trait alias",
+ Target::Impl => "implementation block",
+ Target::Expression => "expression",
+ Target::Statement => "statement",
+ Target::Arm => "match arm",
+ Target::AssocConst => "associated const",
+ Target::Method(kind) => match kind {
+ MethodKind::Inherent => "inherent method",
+ MethodKind::Trait { body: false } => "required trait method",
+ MethodKind::Trait { body: true } => "provided trait method",
+ },
+ Target::AssocTy => "associated type",
+ Target::ForeignFn => "foreign function",
+ Target::ForeignStatic => "foreign static item",
+ Target::ForeignTy => "foreign type",
+ Target::GenericParam(kind) => match kind {
+ GenericParamKind::Type => "type parameter",
+ GenericParamKind::Lifetime => "lifetime parameter",
+ GenericParamKind::Const => "const parameter",
+ },
+ Target::MacroDef => "macro def",
+ Target::Param => "function param",
+ }
+ }
+}
diff --git a/compiler/rustc_hir/src/tests.rs b/compiler/rustc_hir/src/tests.rs
new file mode 100644
index 000000000..4636d5152
--- /dev/null
+++ b/compiler/rustc_hir/src/tests.rs
@@ -0,0 +1,36 @@
+use crate::definitions::{DefKey, DefPathData, DisambiguatedDefPathData};
+use rustc_span::def_id::{DefPathHash, StableCrateId};
+
+#[test]
+fn def_path_hash_depends_on_crate_id() {
+ // This test makes sure that *both* halves of a DefPathHash depend on
+ // the crate-id of the defining crate. This is a desirable property
+ // because the crate-id can be more easily changed than the DefPath
+ // of an item, so, in the case of a crate-local DefPathHash collision,
+ // the user can simply "role the dice again" for all DefPathHashes in
+ // the crate by changing the crate disambiguator (e.g. via bumping the
+ // crate's version number).
+
+ let id0 = StableCrateId::new("foo", false, vec!["1".to_string()]);
+ let id1 = StableCrateId::new("foo", false, vec!["2".to_string()]);
+
+ let h0 = mk_test_hash(id0);
+ let h1 = mk_test_hash(id1);
+
+ assert_ne!(h0.stable_crate_id(), h1.stable_crate_id());
+ assert_ne!(h0.local_hash(), h1.local_hash());
+
+ fn mk_test_hash(stable_crate_id: StableCrateId) -> DefPathHash {
+ let parent_hash = DefPathHash::new(stable_crate_id, 0);
+
+ let key = DefKey {
+ parent: None,
+ disambiguated_data: DisambiguatedDefPathData {
+ data: DefPathData::CrateRoot,
+ disambiguator: 0,
+ },
+ };
+
+ key.compute_stable_hash(parent_hash)
+ }
+}
diff --git a/compiler/rustc_hir/src/weak_lang_items.rs b/compiler/rustc_hir/src/weak_lang_items.rs
new file mode 100644
index 000000000..b6a85c047
--- /dev/null
+++ b/compiler/rustc_hir/src/weak_lang_items.rs
@@ -0,0 +1,47 @@
+//! Validity checking for weak lang items
+
+use crate::def_id::DefId;
+use crate::{lang_items, LangItem, LanguageItems};
+
+use rustc_ast as ast;
+use rustc_data_structures::fx::FxIndexMap;
+use rustc_span::symbol::{sym, Symbol};
+
+use std::sync::LazyLock;
+
+macro_rules! weak_lang_items {
+ ($($name:ident, $item:ident, $sym:ident;)*) => (
+
+pub static WEAK_ITEMS_REFS: LazyLock<FxIndexMap<Symbol, LangItem>> = LazyLock::new(|| {
+ let mut map = FxIndexMap::default();
+ $(map.insert(sym::$name, LangItem::$item);)*
+ map
+});
+
+pub fn link_name(attrs: &[ast::Attribute]) -> Option<Symbol>
+{
+ lang_items::extract(attrs).and_then(|(name, _)| {
+ $(if name == sym::$name {
+ Some(sym::$sym)
+ } else)* {
+ None
+ }
+ })
+}
+
+impl LanguageItems {
+ pub fn is_weak_lang_item(&self, item_def_id: DefId) -> bool {
+ let did = Some(item_def_id);
+
+ $(self.$name() == did)||*
+ }
+}
+
+) }
+
+weak_lang_items! {
+ panic_impl, PanicImpl, rust_begin_unwind;
+ eh_personality, EhPersonality, rust_eh_personality;
+ eh_catch_typeinfo, EhCatchTypeinfo, rust_eh_catch_typeinfo;
+ oom, Oom, rust_oom;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-12 21:07:10 +0000