| //! The code in this module gathers up all of the inherent impls in |
| //! the current crate and organizes them in a map. It winds up |
| //! touching the whole crate and thus must be recomputed completely |
| //! for any change, but it is very cheap to compute. In practice, most |
| //! code in the compiler never *directly* requests this map. Instead, |
| //! it requests the inherent impls specific to some type (via |
| //! `tcx.inherent_impls(def_id)`). That value, however, |
| //! is computed by selecting an idea from this table. |
| |
| use rustc_errors::struct_span_err; |
| use rustc_hir as hir; |
| use rustc_hir::def_id::{CrateNum, DefId, LocalDefId, LOCAL_CRATE}; |
| use rustc_hir::itemlikevisit::ItemLikeVisitor; |
| use rustc_middle::ty::{self, CrateInherentImpls, TyCtxt}; |
| |
| use rustc_ast::ast; |
| use rustc_span::Span; |
| |
| /// On-demand query: yields a map containing all types mapped to their inherent impls. |
| pub fn crate_inherent_impls(tcx: TyCtxt<'_>, crate_num: CrateNum) -> CrateInherentImpls { |
| assert_eq!(crate_num, LOCAL_CRATE); |
| |
| let krate = tcx.hir().krate(); |
| let mut collect = InherentCollect { tcx, impls_map: Default::default() }; |
| krate.visit_all_item_likes(&mut collect); |
| collect.impls_map |
| } |
| |
| /// On-demand query: yields a vector of the inherent impls for a specific type. |
| pub fn inherent_impls(tcx: TyCtxt<'_>, ty_def_id: DefId) -> &[DefId] { |
| assert!(ty_def_id.is_local()); |
| |
| let crate_map = tcx.crate_inherent_impls(ty_def_id.krate); |
| match crate_map.inherent_impls.get(&ty_def_id) { |
| Some(v) => &v[..], |
| None => &[], |
| } |
| } |
| |
| struct InherentCollect<'tcx> { |
| tcx: TyCtxt<'tcx>, |
| impls_map: CrateInherentImpls, |
| } |
| |
| impl ItemLikeVisitor<'v> for InherentCollect<'tcx> { |
| fn visit_item(&mut self, item: &hir::Item<'_>) { |
| let ty = match item.kind { |
| hir::ItemKind::Impl { of_trait: None, ref self_ty, .. } => self_ty, |
| _ => return, |
| }; |
| |
| let def_id = self.tcx.hir().local_def_id(item.hir_id); |
| let self_ty = self.tcx.type_of(def_id); |
| let lang_items = self.tcx.lang_items(); |
| match self_ty.kind { |
| ty::Adt(def, _) => { |
| self.check_def_id(item, def.did); |
| } |
| ty::Foreign(did) => { |
| self.check_def_id(item, did); |
| } |
| ty::Dynamic(ref data, ..) if data.principal_def_id().is_some() => { |
| self.check_def_id(item, data.principal_def_id().unwrap()); |
| } |
| ty::Bool => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.bool_impl(), |
| None, |
| "bool", |
| "bool", |
| item.span, |
| ); |
| } |
| ty::Char => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.char_impl(), |
| None, |
| "char", |
| "char", |
| item.span, |
| ); |
| } |
| ty::Str => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.str_impl(), |
| lang_items.str_alloc_impl(), |
| "str", |
| "str", |
| item.span, |
| ); |
| } |
| ty::Slice(slice_item) if slice_item == self.tcx.types.u8 => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.slice_u8_impl(), |
| lang_items.slice_u8_alloc_impl(), |
| "slice_u8", |
| "[u8]", |
| item.span, |
| ); |
| } |
| ty::Slice(_) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.slice_impl(), |
| lang_items.slice_alloc_impl(), |
| "slice", |
| "[T]", |
| item.span, |
| ); |
| } |
| ty::RawPtr(ty::TypeAndMut { ty: inner, mutbl: hir::Mutability::Not }) |
| if matches!(inner.kind, ty::Slice(_)) => |
| { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.const_slice_ptr_impl(), |
| None, |
| "const_slice_ptr", |
| "*const [T]", |
| item.span, |
| ); |
| } |
| ty::RawPtr(ty::TypeAndMut { ty: inner, mutbl: hir::Mutability::Mut }) |
| if matches!(inner.kind, ty::Slice(_)) => |
| { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.mut_slice_ptr_impl(), |
| None, |
| "mut_slice_ptr", |
| "*mut [T]", |
| item.span, |
| ); |
| } |
| ty::RawPtr(ty::TypeAndMut { ty: _, mutbl: hir::Mutability::Not }) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.const_ptr_impl(), |
| None, |
| "const_ptr", |
| "*const T", |
| item.span, |
| ); |
| } |
| ty::RawPtr(ty::TypeAndMut { ty: _, mutbl: hir::Mutability::Mut }) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.mut_ptr_impl(), |
| None, |
| "mut_ptr", |
| "*mut T", |
| item.span, |
| ); |
| } |
| ty::Int(ast::IntTy::I8) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.i8_impl(), |
| None, |
| "i8", |
| "i8", |
| item.span, |
| ); |
| } |
| ty::Int(ast::IntTy::I16) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.i16_impl(), |
| None, |
| "i16", |
| "i16", |
| item.span, |
| ); |
| } |
| ty::Int(ast::IntTy::I32) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.i32_impl(), |
| None, |
| "i32", |
| "i32", |
| item.span, |
| ); |
| } |
| ty::Int(ast::IntTy::I64) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.i64_impl(), |
| None, |
| "i64", |
| "i64", |
| item.span, |
| ); |
| } |
| ty::Int(ast::IntTy::I128) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.i128_impl(), |
| None, |
| "i128", |
| "i128", |
| item.span, |
| ); |
| } |
| ty::Int(ast::IntTy::Isize) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.isize_impl(), |
| None, |
| "isize", |
| "isize", |
| item.span, |
| ); |
| } |
| ty::Uint(ast::UintTy::U8) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.u8_impl(), |
| None, |
| "u8", |
| "u8", |
| item.span, |
| ); |
| } |
| ty::Uint(ast::UintTy::U16) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.u16_impl(), |
| None, |
| "u16", |
| "u16", |
| item.span, |
| ); |
| } |
| ty::Uint(ast::UintTy::U32) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.u32_impl(), |
| None, |
| "u32", |
| "u32", |
| item.span, |
| ); |
| } |
| ty::Uint(ast::UintTy::U64) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.u64_impl(), |
| None, |
| "u64", |
| "u64", |
| item.span, |
| ); |
| } |
| ty::Uint(ast::UintTy::U128) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.u128_impl(), |
| None, |
| "u128", |
| "u128", |
| item.span, |
| ); |
| } |
| ty::Uint(ast::UintTy::Usize) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.usize_impl(), |
| None, |
| "usize", |
| "usize", |
| item.span, |
| ); |
| } |
| ty::Float(ast::FloatTy::F32) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.f32_impl(), |
| lang_items.f32_runtime_impl(), |
| "f32", |
| "f32", |
| item.span, |
| ); |
| } |
| ty::Float(ast::FloatTy::F64) => { |
| self.check_primitive_impl( |
| def_id, |
| lang_items.f64_impl(), |
| lang_items.f64_runtime_impl(), |
| "f64", |
| "f64", |
| item.span, |
| ); |
| } |
| ty::Error(_) => {} |
| _ => { |
| struct_span_err!( |
| self.tcx.sess, |
| ty.span, |
| E0118, |
| "no base type found for inherent implementation" |
| ) |
| .span_label(ty.span, "impl requires a base type") |
| .note( |
| "either implement a trait on it or create a newtype \ |
| to wrap it instead", |
| ) |
| .emit(); |
| } |
| } |
| } |
| |
| fn visit_trait_item(&mut self, _trait_item: &hir::TraitItem<'_>) {} |
| |
| fn visit_impl_item(&mut self, _impl_item: &hir::ImplItem<'_>) {} |
| } |
| |
| impl InherentCollect<'tcx> { |
| fn check_def_id(&mut self, item: &hir::Item<'_>, def_id: DefId) { |
| if def_id.is_local() { |
| // Add the implementation to the mapping from implementation to base |
| // type def ID, if there is a base type for this implementation and |
| // the implementation does not have any associated traits. |
| let impl_def_id = self.tcx.hir().local_def_id(item.hir_id); |
| let vec = self.impls_map.inherent_impls.entry(def_id).or_default(); |
| vec.push(impl_def_id.to_def_id()); |
| } else { |
| struct_span_err!( |
| self.tcx.sess, |
| item.span, |
| E0116, |
| "cannot define inherent `impl` for a type outside of the crate \ |
| where the type is defined" |
| ) |
| .span_label(item.span, "impl for type defined outside of crate.") |
| .note("define and implement a trait or new type instead") |
| .emit(); |
| } |
| } |
| |
| fn check_primitive_impl( |
| &self, |
| impl_def_id: LocalDefId, |
| lang_def_id: Option<DefId>, |
| lang_def_id2: Option<DefId>, |
| lang: &str, |
| ty: &str, |
| span: Span, |
| ) { |
| match (lang_def_id, lang_def_id2) { |
| (Some(lang_def_id), _) if lang_def_id == impl_def_id.to_def_id() => { |
| // OK |
| } |
| (_, Some(lang_def_id)) if lang_def_id == impl_def_id.to_def_id() => { |
| // OK |
| } |
| _ => { |
| struct_span_err!( |
| self.tcx.sess, |
| span, |
| E0390, |
| "only a single inherent implementation marked with `#[lang = \ |
| \"{}\"]` is allowed for the `{}` primitive", |
| lang, |
| ty |
| ) |
| .span_help(span, "consider using a trait to implement these methods") |
| .emit(); |
| } |
| } |
| } |
| } |
