diff options
Diffstat (limited to 'compiler/rustc_hir/src/def.rs')
| -rw-r--r-- | compiler/rustc_hir/src/def.rs | 125 |
1 files changed, 75 insertions, 50 deletions
diff --git a/compiler/rustc_hir/src/def.rs b/compiler/rustc_hir/src/def.rs index e7c26bd72..4ef4aad90 100644 --- a/compiler/rustc_hir/src/def.rs +++ b/compiler/rustc_hir/src/def.rs @@ -314,74 +314,75 @@ pub enum Res<Id = hir::HirId> { /// **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. + /// The `Self` type, as used within a trait. + /// + /// **Belongs to the type namespace.** + /// + /// See the examples on [`Res::SelfTyAlias`] for details. + SelfTyParam { + /// The trait this `Self` is a generic parameter for. + trait_: DefId, + }, + + /// The `Self` type, as used somewhere other than within a trait. /// /// **Belongs to the type namespace.** /// /// Examples: /// ``` - /// struct Bar(Box<Self>); - /// // `Res::SelfTy { trait_: None, alias_of: Some(Bar) }` + /// struct Bar(Box<Self>); // SelfTyAlias /// /// trait Foo { - /// fn foo() -> Box<Self>; - /// // `Res::SelfTy { trait_: Some(Foo), alias_of: None }` + /// fn foo() -> Box<Self>; // SelfTyParam /// } /// /// impl Bar { /// fn blah() { - /// let _: Self; - /// // `Res::SelfTy { trait_: None, alias_of: Some(::{impl#0}) }` + /// let _: Self; // SelfTyAlias /// } /// } /// /// 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}) }` + /// fn foo() -> Box<Self> { // SelfTyAlias + /// let _: Self; // SelfTyAlias /// /// 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>, + SelfTyAlias { /// 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)>, - }, + /// to get the underlying type. + alias_to: DefId, - /// A tool attribute module; e.g., the `rustfmt` in `#[rustfmt::skip]`. - /// - /// **Belongs to the type namespace.** - ToolMod, + /// Whether the `Self` type is disallowed from mentioning generics (i.e. when used in an + /// anonymous constant). + /// + /// 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. + forbid_generic: bool, + + /// Is this within an `impl Foo for bar`? + is_trait_impl: bool, + }, // Value namespace /// The `Self` constructor, along with the [`DefId`] @@ -389,7 +390,7 @@ pub enum Res<Id = hir::HirId> { /// /// **Belongs to the value namespace.** /// - /// *See also [`Res::SelfTy`].* + /// *See also [`Res::SelfTyParam`] and [`Res::SelfTyAlias`].* SelfCtor(DefId), /// A local variable or function parameter. @@ -397,6 +398,11 @@ pub enum Res<Id = hir::HirId> { /// **Belongs to the value namespace.** Local(Id), + /// A tool attribute module; e.g., the `rustfmt` in `#[rustfmt::skip]`. + /// + /// **Belongs to the type namespace.** + ToolMod, + // Macro namespace /// An attribute that is *not* implemented via macro. /// E.g., `#[inline]` and `#[rustfmt::skip]`, which are essentially directives, @@ -458,6 +464,16 @@ impl PartialRes { pub fn unresolved_segments(&self) -> usize { self.unresolved_segments } + + #[inline] + pub fn full_res(&self) -> Option<Res<NodeId>> { + (self.unresolved_segments == 0).then_some(self.base_res) + } + + #[inline] + pub fn expect_full_res(&self) -> Res<NodeId> { + self.full_res().expect("unexpected unresolved segments") + } } /// Different kinds of symbols can coexist even if they share the same textual name. @@ -606,7 +622,8 @@ impl<Id> Res<Id> { Res::Local(..) | Res::PrimTy(..) - | Res::SelfTy { .. } + | Res::SelfTyParam { .. } + | Res::SelfTyAlias { .. } | Res::SelfCtor(..) | Res::ToolMod | Res::NonMacroAttr(..) @@ -629,7 +646,7 @@ impl<Id> Res<Id> { Res::SelfCtor(..) => "self constructor", Res::PrimTy(..) => "builtin type", Res::Local(..) => "local variable", - Res::SelfTy { .. } => "self type", + Res::SelfTyParam { .. } | Res::SelfTyAlias { .. } => "self type", Res::ToolMod => "tool module", Res::NonMacroAttr(attr_kind) => attr_kind.descr(), Res::Err => "unresolved item", @@ -652,7 +669,10 @@ impl<Id> Res<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::SelfTyParam { trait_ } => Res::SelfTyParam { trait_ }, + Res::SelfTyAlias { alias_to, forbid_generic, is_trait_impl } => { + Res::SelfTyAlias { alias_to, forbid_generic, is_trait_impl } + } Res::ToolMod => Res::ToolMod, Res::NonMacroAttr(attr_kind) => Res::NonMacroAttr(attr_kind), Res::Err => Res::Err, @@ -665,7 +685,10 @@ impl<Id> Res<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::SelfTyParam { trait_ } => Res::SelfTyParam { trait_ }, + Res::SelfTyAlias { alias_to, forbid_generic, is_trait_impl } => { + Res::SelfTyAlias { alias_to, forbid_generic, is_trait_impl } + } Res::ToolMod => Res::ToolMod, Res::NonMacroAttr(attr_kind) => Res::NonMacroAttr(attr_kind), Res::Err => Res::Err, @@ -692,7 +715,9 @@ impl<Id> Res<Id> { pub fn ns(&self) -> Option<Namespace> { match self { Res::Def(kind, ..) => kind.ns(), - Res::PrimTy(..) | Res::SelfTy { .. } | Res::ToolMod => Some(Namespace::TypeNS), + Res::PrimTy(..) | Res::SelfTyParam { .. } | Res::SelfTyAlias { .. } | Res::ToolMod => { + Some(Namespace::TypeNS) + } Res::SelfCtor(..) | Res::Local(..) => Some(Namespace::ValueNS), Res::NonMacroAttr(..) => Some(Namespace::MacroNS), Res::Err => None, |