diff options
Diffstat (limited to 'compiler/rustc_ast_lowering/src/lib.rs')
| -rw-r--r-- | compiler/rustc_ast_lowering/src/lib.rs | 238 |
1 files changed, 145 insertions, 93 deletions
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs index bc6d2cf12..b20157f2c 100644 --- a/compiler/rustc_ast_lowering/src/lib.rs +++ b/compiler/rustc_ast_lowering/src/lib.rs @@ -52,23 +52,28 @@ use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::sorted_map::SortedMap; use rustc_data_structures::stable_hasher::{HashStable, StableHasher}; use rustc_data_structures::sync::Lrc; -use rustc_errors::{DiagnosticArgFromDisplay, Handler, StashKey}; +use rustc_errors::{ + DiagnosticArgFromDisplay, DiagnosticMessage, Handler, StashKey, SubdiagnosticMessage, +}; use rustc_hir as hir; use rustc_hir::def::{DefKind, LifetimeRes, Namespace, PartialRes, PerNS, Res}; use rustc_hir::def_id::{LocalDefId, CRATE_DEF_ID}; use rustc_hir::definitions::DefPathData; use rustc_hir::{ConstArg, GenericArg, ItemLocalId, ParamName, TraitCandidate}; use rustc_index::vec::{Idx, IndexVec}; -use rustc_middle::span_bug; -use rustc_middle::ty::{ResolverAstLowering, TyCtxt}; +use rustc_macros::fluent_messages; +use rustc_middle::{ + span_bug, + ty::{ResolverAstLowering, TyCtxt}, +}; use rustc_session::parse::feature_err; use rustc_span::hygiene::MacroKind; use rustc_span::source_map::DesugaringKind; use rustc_span::symbol::{kw, sym, Ident, Symbol}; use rustc_span::{Span, DUMMY_SP}; - use smallvec::SmallVec; use std::collections::hash_map::Entry; +use thin_vec::ThinVec; macro_rules! arena_vec { ($this:expr; $($x:expr),*) => ( @@ -80,12 +85,15 @@ mod asm; mod block; mod errors; mod expr; +mod format; mod index; mod item; mod lifetime_collector; mod pat; mod path; +fluent_messages! { "../locales/en-US.ftl" } + struct LoweringContext<'a, 'hir> { tcx: TyCtxt<'hir>, resolver: &'a mut ResolverAstLowering, @@ -118,7 +126,6 @@ struct LoweringContext<'a, 'hir> { current_hir_id_owner: hir::OwnerId, item_local_id_counter: hir::ItemLocalId, - local_id_to_def_id: SortedMap<ItemLocalId, LocalDefId>, trait_map: FxHashMap<ItemLocalId, Box<[TraitCandidate]>>, impl_trait_defs: Vec<hir::GenericParam<'hir>>, @@ -253,7 +260,6 @@ enum ImplTraitContext { enum ImplTraitPosition { Path, Variable, - Type, Trait, AsyncBlock, Bound, @@ -270,30 +276,43 @@ enum ImplTraitPosition { FnTraitReturn, TraitReturn, ImplReturn, + GenericDefault, + ConstTy, + StaticTy, + AssocTy, + FieldTy, + Cast, + ImplSelf, } impl std::fmt::Display for ImplTraitPosition { fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { let name = match self { - ImplTraitPosition::Path => "path", - ImplTraitPosition::Variable => "variable binding", - ImplTraitPosition::Type => "type", - ImplTraitPosition::Trait => "trait", - ImplTraitPosition::AsyncBlock => "async block", - ImplTraitPosition::Bound => "bound", - ImplTraitPosition::Generic => "generic", - ImplTraitPosition::ExternFnParam => "`extern fn` param", - ImplTraitPosition::ClosureParam => "closure param", - ImplTraitPosition::PointerParam => "`fn` pointer param", - ImplTraitPosition::FnTraitParam => "`Fn` trait param", - ImplTraitPosition::TraitParam => "trait method param", - ImplTraitPosition::ImplParam => "`impl` method param", - ImplTraitPosition::ExternFnReturn => "`extern fn` return", - ImplTraitPosition::ClosureReturn => "closure return", - ImplTraitPosition::PointerReturn => "`fn` pointer return", - ImplTraitPosition::FnTraitReturn => "`Fn` trait return", - ImplTraitPosition::TraitReturn => "trait method return", - ImplTraitPosition::ImplReturn => "`impl` method return", + ImplTraitPosition::Path => "paths", + ImplTraitPosition::Variable => "variable bindings", + ImplTraitPosition::Trait => "traits", + ImplTraitPosition::AsyncBlock => "async blocks", + ImplTraitPosition::Bound => "bounds", + ImplTraitPosition::Generic => "generics", + ImplTraitPosition::ExternFnParam => "`extern fn` params", + ImplTraitPosition::ClosureParam => "closure params", + ImplTraitPosition::PointerParam => "`fn` pointer params", + ImplTraitPosition::FnTraitParam => "`Fn` trait params", + ImplTraitPosition::TraitParam => "trait method params", + ImplTraitPosition::ImplParam => "`impl` method params", + ImplTraitPosition::ExternFnReturn => "`extern fn` return types", + ImplTraitPosition::ClosureReturn => "closure return types", + ImplTraitPosition::PointerReturn => "`fn` pointer return types", + ImplTraitPosition::FnTraitReturn => "`Fn` trait return types", + ImplTraitPosition::TraitReturn => "trait method return types", + ImplTraitPosition::ImplReturn => "`impl` method return types", + ImplTraitPosition::GenericDefault => "generic parameter defaults", + ImplTraitPosition::ConstTy => "const types", + ImplTraitPosition::StaticTy => "static types", + ImplTraitPosition::AssocTy => "associated types", + ImplTraitPosition::FieldTy => "field types", + ImplTraitPosition::Cast => "cast types", + ImplTraitPosition::ImplSelf => "impl headers", }; write!(f, "{name}") @@ -416,6 +435,7 @@ fn compute_hir_hash( pub fn lower_to_hir(tcx: TyCtxt<'_>, (): ()) -> hir::Crate<'_> { let sess = tcx.sess; + tcx.ensure().output_filenames(()); let (mut resolver, krate) = tcx.resolver_for_lowering(()).steal(); let ast_index = index_crate(&resolver.node_id_to_def_id, &krate); @@ -565,7 +585,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { let current_attrs = std::mem::take(&mut self.attrs); let current_bodies = std::mem::take(&mut self.bodies); let current_node_ids = std::mem::take(&mut self.node_id_to_local_id); - let current_id_to_def_id = std::mem::take(&mut self.local_id_to_def_id); let current_trait_map = std::mem::take(&mut self.trait_map); let current_owner = std::mem::replace(&mut self.current_hir_id_owner, hir::OwnerId { def_id }); @@ -592,7 +611,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { self.attrs = current_attrs; self.bodies = current_bodies; self.node_id_to_local_id = current_node_ids; - self.local_id_to_def_id = current_id_to_def_id; self.trait_map = current_trait_map; self.current_hir_id_owner = current_owner; self.item_local_id_counter = current_local_counter; @@ -627,7 +645,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { fn make_owner_info(&mut self, node: hir::OwnerNode<'hir>) -> &'hir hir::OwnerInfo<'hir> { let attrs = std::mem::take(&mut self.attrs); let mut bodies = std::mem::take(&mut self.bodies); - let local_id_to_def_id = std::mem::take(&mut self.local_id_to_def_id); let trait_map = std::mem::take(&mut self.trait_map); #[cfg(debug_assertions)] @@ -643,13 +660,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { let (hash_including_bodies, hash_without_bodies) = self.hash_owner(node, &bodies); let (nodes, parenting) = index::index_hir(self.tcx.sess, &*self.tcx.definitions_untracked(), node, &bodies); - let nodes = hir::OwnerNodes { - hash_including_bodies, - hash_without_bodies, - nodes, - bodies, - local_id_to_def_id, - }; + let nodes = hir::OwnerNodes { hash_including_bodies, hash_without_bodies, nodes, bodies }; let attrs = { let hash = self.tcx.with_stable_hashing_context(|mut hcx| { let mut stable_hasher = StableHasher::new(); @@ -708,7 +719,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { assert_ne!(local_id, hir::ItemLocalId::new(0)); if let Some(def_id) = self.opt_local_def_id(ast_node_id) { self.children.push((def_id, hir::MaybeOwner::NonOwner(hir_id))); - self.local_id_to_def_id.insert(local_id, def_id); } if let Some(traits) = self.resolver.trait_map.remove(&ast_node_id) { @@ -794,6 +804,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { ident: Ident, node_id: NodeId, res: LifetimeRes, + source: hir::GenericParamSource, ) -> Option<hir::GenericParam<'hir>> { let (name, kind) = match res { LifetimeRes::Param { .. } => { @@ -827,6 +838,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { pure_wrt_drop: false, kind: hir::GenericParamKind::Lifetime { kind }, colon_span: None, + source, }) } @@ -842,11 +854,13 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { binder: NodeId, generic_params: &[GenericParam], ) -> &'hir [hir::GenericParam<'hir>] { - let mut generic_params: Vec<_> = self.lower_generic_params_mut(generic_params).collect(); + let mut generic_params: Vec<_> = self + .lower_generic_params_mut(generic_params, hir::GenericParamSource::Binder) + .collect(); let extra_lifetimes = self.resolver.take_extra_lifetime_params(binder); debug!(?extra_lifetimes); generic_params.extend(extra_lifetimes.into_iter().filter_map(|(ident, node_id, res)| { - self.lifetime_res_to_generic_param(ident, node_id, res) + self.lifetime_res_to_generic_param(ident, node_id, res, hir::GenericParamSource::Binder) })); let generic_params = self.arena.alloc_from_iter(generic_params); debug!(?generic_params); @@ -992,8 +1006,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { } else { self.arena.alloc(hir::GenericArgs::none()) }; - let itctx_tait = &ImplTraitContext::TypeAliasesOpaqueTy; - let kind = match &constraint.kind { AssocConstraintKind::Equality { term } => { let term = match term { @@ -1003,8 +1015,14 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { hir::TypeBindingKind::Equality { term } } AssocConstraintKind::Bound { bounds } => { + enum DesugarKind<'a> { + ImplTrait, + Error(&'a ImplTraitPosition), + Bound, + } + // Piggy-back on the `impl Trait` context to figure out the correct behavior. - let (desugar_to_impl_trait, itctx) = match itctx { + let desugar_kind = match itctx { // We are in the return position: // // fn foo() -> impl Iterator<Item: Debug> @@ -1013,7 +1031,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { // // fn foo() -> impl Iterator<Item = impl Debug> ImplTraitContext::ReturnPositionOpaqueTy { .. } - | ImplTraitContext::TypeAliasesOpaqueTy { .. } => (true, itctx), + | ImplTraitContext::TypeAliasesOpaqueTy { .. } => DesugarKind::ImplTrait, // We are in the argument position, but within a dyn type: // @@ -1022,15 +1040,11 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { // so desugar to // // fn foo(x: dyn Iterator<Item = impl Debug>) - ImplTraitContext::Universal if self.is_in_dyn_type => (true, itctx), + ImplTraitContext::Universal if self.is_in_dyn_type => DesugarKind::ImplTrait, - // In `type Foo = dyn Iterator<Item: Debug>` we desugar to - // `type Foo = dyn Iterator<Item = impl Debug>` but we have to override the - // "impl trait context" to permit `impl Debug` in this position (it desugars - // then to an opaque type). - // - // FIXME: this is only needed until `impl Trait` is allowed in type aliases. - ImplTraitContext::Disallowed(_) if self.is_in_dyn_type => (true, itctx_tait), + ImplTraitContext::Disallowed(position) if self.is_in_dyn_type => { + DesugarKind::Error(position) + } // We are in the parameter position, but not within a dyn type: // @@ -1039,35 +1053,47 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { // so we leave it as is and this gets expanded in astconv to a bound like // `<T as Iterator>::Item: Debug` where `T` is the type parameter for the // `impl Iterator`. - _ => (false, itctx), + _ => DesugarKind::Bound, }; - if desugar_to_impl_trait { - // Desugar `AssocTy: Bounds` into `AssocTy = impl Bounds`. We do this by - // constructing the HIR for `impl bounds...` and then lowering that. - - let impl_trait_node_id = self.next_node_id(); - - self.with_dyn_type_scope(false, |this| { - let node_id = this.next_node_id(); - let ty = this.lower_ty( - &Ty { - id: node_id, - kind: TyKind::ImplTrait(impl_trait_node_id, bounds.clone()), - span: this.lower_span(constraint.span), - tokens: None, - }, - itctx, - ); + match desugar_kind { + DesugarKind::ImplTrait => { + // Desugar `AssocTy: Bounds` into `AssocTy = impl Bounds`. We do this by + // constructing the HIR for `impl bounds...` and then lowering that. - hir::TypeBindingKind::Equality { term: ty.into() } - }) - } else { - // Desugar `AssocTy: Bounds` into a type binding where the - // later desugars into a trait predicate. - let bounds = self.lower_param_bounds(bounds, itctx); + let impl_trait_node_id = self.next_node_id(); + + self.with_dyn_type_scope(false, |this| { + let node_id = this.next_node_id(); + let ty = this.lower_ty( + &Ty { + id: node_id, + kind: TyKind::ImplTrait(impl_trait_node_id, bounds.clone()), + span: this.lower_span(constraint.span), + tokens: None, + }, + itctx, + ); + + hir::TypeBindingKind::Equality { term: ty.into() } + }) + } + DesugarKind::Bound => { + // Desugar `AssocTy: Bounds` into a type binding where the + // later desugars into a trait predicate. + let bounds = self.lower_param_bounds(bounds, itctx); - hir::TypeBindingKind::Constraint { bounds } + hir::TypeBindingKind::Constraint { bounds } + } + DesugarKind::Error(position) => { + let guar = self.tcx.sess.emit_err(errors::MisplacedAssocTyBinding { + span: constraint.span, + position: DiagnosticArgFromDisplay(position), + }); + let err_ty = + &*self.arena.alloc(self.ty(constraint.span, hir::TyKind::Err(guar))); + hir::TypeBindingKind::Equality { term: err_ty.into() } + } } } }; @@ -1204,7 +1230,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { let (bounds, lifetime_bound) = self.with_dyn_type_scope(true, |this| { let bound = this.lower_poly_trait_ref( &PolyTraitRef { - bound_generic_params: vec![], + bound_generic_params: ThinVec::new(), trait_ref: TraitRef { path: path.clone(), ref_id: t.id }, span: t.span }, @@ -1234,7 +1260,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { fn lower_ty_direct(&mut self, t: &Ty, itctx: &ImplTraitContext) -> hir::Ty<'hir> { let kind = match &t.kind { TyKind::Infer => hir::TyKind::Infer, - TyKind::Err => hir::TyKind::Err, + TyKind::Err => { + hir::TyKind::Err(self.tcx.sess.delay_span_bug(t.span, "TyKind::Err lowered")) + } TyKind::Slice(ty) => hir::TyKind::Slice(self.lower_ty(ty, itctx)), TyKind::Ptr(mt) => hir::TyKind::Ptr(self.lower_mt(mt, itctx)), TyKind::Ref(region, mt) => { @@ -1351,8 +1379,12 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { span, ); let ident = Ident::from_str_and_span(&pprust::ty_to_string(t), span); - let (param, bounds, path) = - self.lower_generic_and_bounds(*def_node_id, span, ident, bounds); + let (param, bounds, path) = self.lower_universal_param_and_bounds( + *def_node_id, + span, + ident, + bounds, + ); self.impl_trait_defs.push(param); if let Some(bounds) = bounds { self.impl_trait_bounds.push(bounds); @@ -1360,7 +1392,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { path } ImplTraitContext::FeatureGated(position, feature) => { - self.tcx + let guar = self + .tcx .sess .create_feature_err( MisplacedImplTrait { @@ -1370,24 +1403,24 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { *feature, ) .emit(); - hir::TyKind::Err + hir::TyKind::Err(guar) } ImplTraitContext::Disallowed(position) => { - self.tcx.sess.emit_err(MisplacedImplTrait { + let guar = self.tcx.sess.emit_err(MisplacedImplTrait { span: t.span, position: DiagnosticArgFromDisplay(position), }); - hir::TyKind::Err + hir::TyKind::Err(guar) } } } TyKind::MacCall(_) => panic!("`TyKind::MacCall` should have been expanded by now"), TyKind::CVarArgs => { - self.tcx.sess.delay_span_bug( + let guar = self.tcx.sess.delay_span_bug( t.span, "`TyKind::CVarArgs` should have been handled elsewhere", ); - hir::TyKind::Err + hir::TyKind::Err(guar) } }; @@ -1505,6 +1538,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { pure_wrt_drop: false, kind: hir::GenericParamKind::Lifetime { kind }, colon_span: None, + source: hir::GenericParamSource::Generics, } }, )); @@ -1573,7 +1607,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { hir::OwnerNode::Item(self.arena.alloc(opaque_ty_item)) } - /// Given a `parent_def_id`, a list of `lifetimes_in_bounds and a `remapping` hash to be + /// Given a `parent_def_id`, a list of `lifetimes_in_bounds` and a `remapping` hash to be /// filled, this function creates new definitions for `Param` and `Fresh` lifetimes, inserts the /// new definition, adds it to the remapping with the definition of the given lifetime and /// returns a list of lifetimes to be lowered afterwards. @@ -1962,6 +1996,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { pure_wrt_drop: false, kind: hir::GenericParamKind::Lifetime { kind }, colon_span: None, + source: hir::GenericParamSource::Generics, } }, )); @@ -2127,16 +2162,25 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { fn lower_generic_params_mut<'s>( &'s mut self, params: &'s [GenericParam], + source: hir::GenericParamSource, ) -> impl Iterator<Item = hir::GenericParam<'hir>> + Captures<'a> + Captures<'s> { - params.iter().map(move |param| self.lower_generic_param(param)) + params.iter().map(move |param| self.lower_generic_param(param, source)) } - fn lower_generic_params(&mut self, params: &[GenericParam]) -> &'hir [hir::GenericParam<'hir>] { - self.arena.alloc_from_iter(self.lower_generic_params_mut(params)) + fn lower_generic_params( + &mut self, + params: &[GenericParam], + source: hir::GenericParamSource, + ) -> &'hir [hir::GenericParam<'hir>] { + self.arena.alloc_from_iter(self.lower_generic_params_mut(params, source)) } #[instrument(level = "trace", skip(self))] - fn lower_generic_param(&mut self, param: &GenericParam) -> hir::GenericParam<'hir> { + fn lower_generic_param( + &mut self, + param: &GenericParam, + source: hir::GenericParamSource, + ) -> hir::GenericParam<'hir> { let (name, kind) = self.lower_generic_param_kind(param); let hir_id = self.lower_node_id(param.id); @@ -2149,6 +2193,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { pure_wrt_drop: self.tcx.sess.contains_name(¶m.attrs, sym::may_dangle), kind, colon_span: param.colon_span.map(|s| self.lower_span(s)), + source, } } @@ -2175,7 +2220,10 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { GenericParamKind::Type { default, .. } => { let kind = hir::GenericParamKind::Type { default: default.as_ref().map(|x| { - self.lower_ty(x, &ImplTraitContext::Disallowed(ImplTraitPosition::Type)) + self.lower_ty( + x, + &ImplTraitContext::Disallowed(ImplTraitPosition::GenericDefault), + ) }), synthetic: false, }; @@ -2183,7 +2231,10 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { (hir::ParamName::Plain(self.lower_ident(param.ident)), kind) } GenericParamKind::Const { ty, kw_span: _, default } => { - let ty = self.lower_ty(&ty, &ImplTraitContext::Disallowed(ImplTraitPosition::Type)); + let ty = self.lower_ty( + &ty, + &ImplTraitContext::Disallowed(ImplTraitPosition::GenericDefault), + ); let default = default.as_ref().map(|def| self.lower_anon_const(def)); ( hir::ParamName::Plain(self.lower_ident(param.ident)), @@ -2235,7 +2286,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { } #[instrument(level = "debug", skip(self), ret)] - fn lower_generic_and_bounds( + fn lower_universal_param_and_bounds( &mut self, node_id: NodeId, span: Span, @@ -2255,6 +2306,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { span, kind: hir::GenericParamKind::Type { default: None, synthetic: true }, colon_span: None, + source: hir::GenericParamSource::Generics, }; let preds = self.lower_generic_bound_predicate( |