diff options
Diffstat (limited to 'compiler/rustc_ast_lowering/src/lib.rs')
| -rw-r--r-- | compiler/rustc_ast_lowering/src/lib.rs | 365 |
1 files changed, 176 insertions, 189 deletions
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs index ff29d15f1..4fa18907f 100644 --- a/compiler/rustc_ast_lowering/src/lib.rs +++ b/compiler/rustc_ast_lowering/src/lib.rs @@ -34,7 +34,6 @@ #![feature(let_chains)] #![feature(never_type)] #![recursion_limit = "256"] -#![allow(rustc::potential_query_instability)] #![deny(rustc::untranslatable_diagnostic)] #![deny(rustc::diagnostic_outside_of_impl)] @@ -61,8 +60,8 @@ 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_middle::{bug, span_bug}; use rustc_session::parse::feature_err; use rustc_span::hygiene::MacroKind; use rustc_span::source_map::DesugaringKind; @@ -107,7 +106,7 @@ struct LoweringContext<'a, 'hir> { /// Attributes inside the owner being lowered. attrs: SortedMap<hir::ItemLocalId, &'hir [Attribute]>, /// Collect items that were created by lowering the current owner. - children: FxHashMap<LocalDefId, hir::MaybeOwner<&'hir hir::OwnerInfo<'hir>>>, + children: Vec<(LocalDefId, hir::MaybeOwner<&'hir hir::OwnerInfo<'hir>>)>, generator_kind: Option<hir::GeneratorKind>, @@ -260,6 +259,8 @@ enum ImplTraitContext { }, /// Impl trait in type aliases. TypeAliasesOpaqueTy, + /// `impl Trait` is unstably accepted in this position. + FeatureGated(ImplTraitPosition, Symbol), /// `impl Trait` is not accepted in this position. Disallowed(ImplTraitPosition), } @@ -328,7 +329,14 @@ enum FnDeclKind { } impl FnDeclKind { - fn impl_trait_allowed(&self, tcx: TyCtxt<'_>) -> bool { + fn param_impl_trait_allowed(&self) -> bool { + match self { + FnDeclKind::Fn | FnDeclKind::Inherent | FnDeclKind::Impl | FnDeclKind::Trait => true, + _ => false, + } + } + + fn return_impl_trait_allowed(&self, tcx: TyCtxt<'_>) -> bool { match self { FnDeclKind::Fn | FnDeclKind::Inherent => true, FnDeclKind::Impl if tcx.features().return_position_impl_trait_in_trait => true, @@ -481,6 +489,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { parent: LocalDefId, node_id: ast::NodeId, data: DefPathData, + span: Span, ) -> LocalDefId { debug_assert_ne!(node_id, ast::DUMMY_NODE_ID); assert!( @@ -491,7 +500,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { self.tcx.hir().def_key(self.local_def_id(node_id)), ); - let def_id = self.tcx.create_def(parent, data); + let def_id = self.tcx.at(span).create_def(parent, data).def_id(); debug!("create_def: def_id_to_node_id[{:?}] <-> {:?}", def_id, node_id); self.resolver.node_id_to_def_id.insert(node_id, def_id); @@ -611,8 +620,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { self.impl_trait_defs = current_impl_trait_defs; self.impl_trait_bounds = current_impl_trait_bounds; - let _old = self.children.insert(def_id, hir::MaybeOwner::Owner(info)); - debug_assert!(_old.is_none()) + debug_assert!(self.children.iter().find(|(id, _)| id == &def_id).is_none()); + self.children.push((def_id, hir::MaybeOwner::Owner(info))); } /// Installs the remapping `remap` in scope while `f` is being executed. @@ -719,8 +728,7 @@ 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) { - // Do not override a `MaybeOwner::Owner` that may already here. - self.children.entry(def_id).or_insert(hir::MaybeOwner::NonOwner(hir_id)); + self.children.push((def_id, hir::MaybeOwner::NonOwner(hir_id))); self.local_id_to_def_id.insert(local_id, def_id); } @@ -818,6 +826,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { self.current_hir_id_owner.def_id, param, DefPathData::LifetimeNs(kw::UnderscoreLifetime), + ident.span, ); debug!(?_def_id); @@ -830,8 +839,10 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { ), }; let hir_id = self.lower_node_id(node_id); + let def_id = self.local_def_id(node_id); Some(hir::GenericParam { hir_id, + def_id, name, span: self.lower_span(ident.span), pure_wrt_drop: false, @@ -911,7 +922,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { AttrKind::Normal(ref normal) => AttrKind::Normal(P(NormalAttr { item: AttrItem { path: normal.item.path.clone(), - args: self.lower_mac_args(&normal.item.args), + args: self.lower_attr_args(&normal.item.args), tokens: None, }, tokens: None, @@ -931,51 +942,39 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { } } - fn lower_mac_args(&self, args: &MacArgs) -> MacArgs { - match *args { - MacArgs::Empty => MacArgs::Empty, - MacArgs::Delimited(dspan, delim, ref tokens) => { - // This is either a non-key-value attribute, or a `macro_rules!` body. - // We either not have any nonterminals present (in the case of an attribute), - // or have tokens available for all nonterminals in the case of a nested - // `macro_rules`: e.g: - // - // ```rust - // macro_rules! outer { - // ($e:expr) => { - // macro_rules! inner { - // () => { $e } - // } - // } - // } - // ``` - // - // In both cases, we don't want to synthesize any tokens - MacArgs::Delimited(dspan, delim, tokens.flattened()) - } + fn lower_attr_args(&self, args: &AttrArgs) -> AttrArgs { + match args { + AttrArgs::Empty => AttrArgs::Empty, + AttrArgs::Delimited(args) => AttrArgs::Delimited(self.lower_delim_args(args)), // This is an inert key-value attribute - it will never be visible to macros // after it gets lowered to HIR. Therefore, we can extract literals to handle // nonterminals in `#[doc]` (e.g. `#[doc = $e]`). - MacArgs::Eq(eq_span, MacArgsEq::Ast(ref expr)) => { + AttrArgs::Eq(eq_span, AttrArgsEq::Ast(expr)) => { // In valid code the value always ends up as a single literal. Otherwise, a dummy // literal suffices because the error is handled elsewhere. - let lit = if let ExprKind::Lit(lit) = &expr.kind { - lit.clone() + let lit = if let ExprKind::Lit(token_lit) = expr.kind + && let Ok(lit) = MetaItemLit::from_token_lit(token_lit, expr.span) + { + lit } else { - Lit { + MetaItemLit { token_lit: token::Lit::new(token::LitKind::Err, kw::Empty, None), kind: LitKind::Err, span: DUMMY_SP, } }; - MacArgs::Eq(eq_span, MacArgsEq::Hir(lit)) + AttrArgs::Eq(*eq_span, AttrArgsEq::Hir(lit)) } - MacArgs::Eq(_, MacArgsEq::Hir(ref lit)) => { + AttrArgs::Eq(_, AttrArgsEq::Hir(lit)) => { unreachable!("in literal form when lowering mac args eq: {:?}", lit) } } } + fn lower_delim_args(&self, args: &DelimArgs) -> DelimArgs { + DelimArgs { dspan: args.dspan, delim: args.delim, tokens: args.tokens.flattened() } + } + /// Given an associated type constraint like one of these: /// /// ```ignore (illustrative) @@ -994,12 +993,12 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { ) -> hir::TypeBinding<'hir> { debug!("lower_assoc_ty_constraint(constraint={:?}, itctx={:?})", constraint, itctx); // lower generic arguments of identifier in constraint - let gen_args = if let Some(ref gen_args) = constraint.gen_args { + let gen_args = if let Some(gen_args) = &constraint.gen_args { let gen_args_ctor = match gen_args { - GenericArgs::AngleBracketed(ref data) => { + GenericArgs::AngleBracketed(data) => { self.lower_angle_bracketed_parameter_data(data, ParamMode::Explicit, itctx).0 } - GenericArgs::Parenthesized(ref data) => { + GenericArgs::Parenthesized(data) => { self.emit_bad_parenthesized_trait_in_assoc_ty(data); let aba = self.ast_arena.aba.alloc(data.as_angle_bracketed_args()); self.lower_angle_bracketed_parameter_data(aba, ParamMode::Explicit, itctx).0 @@ -1011,15 +1010,15 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { }; let itctx_tait = &ImplTraitContext::TypeAliasesOpaqueTy; - let kind = match constraint.kind { - AssocConstraintKind::Equality { ref term } => { + let kind = match &constraint.kind { + AssocConstraintKind::Equality { term } => { let term = match term { - Term::Ty(ref ty) => self.lower_ty(ty, itctx).into(), - Term::Const(ref c) => self.lower_anon_const(c).into(), + Term::Ty(ty) => self.lower_ty(ty, itctx).into(), + Term::Const(c) => self.lower_anon_const(c).into(), }; hir::TypeBindingKind::Equality { term } } - AssocConstraintKind::Bound { ref bounds } => { + AssocConstraintKind::Bound { bounds } => { // Piggy-back on the `impl Trait` context to figure out the correct behavior. let (desugar_to_impl_trait, itctx) = match itctx { // We are in the return position: @@ -1129,7 +1128,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { match arg { ast::GenericArg::Lifetime(lt) => GenericArg::Lifetime(self.lower_lifetime(<)), ast::GenericArg::Type(ty) => { - match ty.kind { + match &ty.kind { TyKind::Infer if self.tcx.features().generic_arg_infer => { return GenericArg::Infer(hir::InferArg { hir_id: self.lower_node_id(ty.id), @@ -1140,7 +1139,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { // parsing. We try to resolve that ambiguity by attempting resolution in both the // type and value namespaces. If we resolved the path in the value namespace, we // transform it into a generic const argument. - TyKind::Path(ref qself, ref path) => { + TyKind::Path(qself, path) => { if let Some(res) = self .resolver .get_partial_res(ty.id) @@ -1156,15 +1155,16 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { let parent_def_id = self.current_hir_id_owner; let node_id = self.next_node_id(); + let span = self.lower_span(ty.span); // Add a definition for the in-band const def. - self.create_def( + let def_id = self.create_def( parent_def_id.def_id, node_id, DefPathData::AnonConst, + span, ); - let span = self.lower_span(ty.span); let path_expr = Expr { id: ty.id, kind: ExprKind::Path(qself.clone(), path.clone()), @@ -1174,6 +1174,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { }; let ct = self.with_new_scopes(|this| hir::AnonConst { + def_id, hir_id: this.lower_node_id(node_id), body: this.lower_const_body(path_expr.span, Some(&path_expr)), }); @@ -1200,7 +1201,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { fn lower_path_ty( &mut self, t: &Ty, - qself: &Option<QSelf>, + qself: &Option<ptr::P<QSelf>>, path: &Path, param_mode: ParamMode, itctx: &ImplTraitContext, @@ -1246,12 +1247,12 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { } fn lower_ty_direct(&mut self, t: &Ty, itctx: &ImplTraitContext) -> hir::Ty<'hir> { - let kind = match t.kind { + let kind = match &t.kind { TyKind::Infer => hir::TyKind::Infer, TyKind::Err => hir::TyKind::Err, - TyKind::Slice(ref ty) => hir::TyKind::Slice(self.lower_ty(ty, itctx)), - TyKind::Ptr(ref mt) => hir::TyKind::Ptr(self.lower_mt(mt, itctx)), - TyKind::Rptr(ref region, ref mt) => { + TyKind::Slice(ty) => hir::TyKind::Slice(self.lower_ty(ty, itctx)), + TyKind::Ptr(mt) => hir::TyKind::Ptr(self.lower_mt(mt, itctx)), + TyKind::Rptr(region, mt) => { let region = region.unwrap_or_else(|| { let id = if let Some(LifetimeRes::ElidedAnchor { start, end }) = self.resolver.get_lifetime_res(t.id) @@ -1261,30 +1262,30 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { } else { self.next_node_id() }; - let span = self.tcx.sess.source_map().start_point(t.span); + let span = self.tcx.sess.source_map().start_point(t.span).shrink_to_hi(); Lifetime { ident: Ident::new(kw::UnderscoreLifetime, span), id } }); let lifetime = self.lower_lifetime(®ion); hir::TyKind::Rptr(lifetime, self.lower_mt(mt, itctx)) } - TyKind::BareFn(ref f) => { + TyKind::BareFn(f) => { let generic_params = self.lower_lifetime_binder(t.id, &f.generic_params); hir::TyKind::BareFn(self.arena.alloc(hir::BareFnTy { generic_params, unsafety: self.lower_unsafety(f.unsafety), abi: self.lower_extern(f.ext), - decl: self.lower_fn_decl(&f.decl, None, t.span, FnDeclKind::Pointer, None), + decl: self.lower_fn_decl(&f.decl, t.id, t.span, FnDeclKind::Pointer, None), param_names: self.lower_fn_params_to_names(&f.decl), })) } TyKind::Never => hir::TyKind::Never, - TyKind::Tup(ref tys) => hir::TyKind::Tup( + TyKind::Tup(tys) => hir::TyKind::Tup( self.arena.alloc_from_iter(tys.iter().map(|ty| self.lower_ty_direct(ty, itctx))), ), - TyKind::Paren(ref ty) => { + TyKind::Paren(ty) => { return self.lower_ty_direct(ty, itctx); } - TyKind::Path(ref qself, ref path) => { + TyKind::Path(qself, path) => { return self.lower_path_ty(t, qself, path, ParamMode::Explicit, itctx); } TyKind::ImplicitSelf => { @@ -1304,48 +1305,46 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { }), )) } - TyKind::Array(ref ty, ref length) => { + TyKind::Array(ty, length) => { hir::TyKind::Array(self.lower_ty(ty, itctx), self.lower_array_length(length)) } - TyKind::Typeof(ref expr) => hir::TyKind::Typeof(self.lower_anon_const(expr)), - TyKind::TraitObject(ref bounds, kind) => { + TyKind::Typeof(expr) => hir::TyKind::Typeof(self.lower_anon_const(expr)), + TyKind::TraitObject(bounds, kind) => { let mut lifetime_bound = None; let (bounds, lifetime_bound) = self.with_dyn_type_scope(true, |this| { let bounds = - this.arena.alloc_from_iter(bounds.iter().filter_map( - |bound| match *bound { - GenericBound::Trait( - ref ty, - TraitBoundModifier::None | TraitBoundModifier::MaybeConst, - ) => Some(this.lower_poly_trait_ref(ty, itctx)), - // `~const ?Bound` will cause an error during AST validation - // anyways, so treat it like `?Bound` as compilation proceeds. - GenericBound::Trait( - _, - TraitBoundModifier::Maybe | TraitBoundModifier::MaybeConstMaybe, - ) => None, - GenericBound::Outlives(ref lifetime) => { - if lifetime_bound.is_none() { - lifetime_bound = Some(this.lower_lifetime(lifetime)); - } - None + this.arena.alloc_from_iter(bounds.iter().filter_map(|bound| match bound { + GenericBound::Trait( + ty, + TraitBoundModifier::None | TraitBoundModifier::MaybeConst, + ) => Some(this.lower_poly_trait_ref(ty, itctx)), + // `~const ?Bound` will cause an error during AST validation + // anyways, so treat it like `?Bound` as compilation proceeds. + GenericBound::Trait( + _, + TraitBoundModifier::Maybe | TraitBoundModifier::MaybeConstMaybe, + ) => None, + GenericBound::Outlives(lifetime) => { + if lifetime_bound.is_none() { + lifetime_bound = Some(this.lower_lifetime(lifetime)); } - }, - )); + None + } + })); let lifetime_bound = lifetime_bound.unwrap_or_else(|| this.elided_dyn_bound(t.span)); (bounds, lifetime_bound) }); - hir::TyKind::TraitObject(bounds, lifetime_bound, kind) + hir::TyKind::TraitObject(bounds, lifetime_bound, *kind) } - TyKind::ImplTrait(def_node_id, ref bounds) => { + TyKind::ImplTrait(def_node_id, bounds) => { let span = t.span; match itctx { ImplTraitContext::ReturnPositionOpaqueTy { origin, in_trait } => self .lower_opaque_impl_trait( span, *origin, - def_node_id, + *def_node_id, bounds, *in_trait, itctx, @@ -1353,38 +1352,37 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { ImplTraitContext::TypeAliasesOpaqueTy => self.lower_opaque_impl_trait( span, hir::OpaqueTyOrigin::TyAlias, - def_node_id, + *def_node_id, bounds, false, itctx, ), ImplTraitContext::Universal => { + let span = t.span; self.create_def( self.current_hir_id_owner.def_id, - def_node_id, + *def_node_id, DefPathData::ImplTrait, + span, ); - let span = t.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); + self.lower_generic_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); } path } - ImplTraitContext::Disallowed( - position @ (ImplTraitPosition::TraitReturn | ImplTraitPosition::ImplReturn), - ) => { + ImplTraitContext::FeatureGated(position, feature) => { self.tcx .sess .create_feature_err( MisplacedImplTrait { span: t.span, - position: DiagnosticArgFromDisplay(&position), + position: DiagnosticArgFromDisplay(position), }, - sym::return_position_impl_trait_in_trait, + *feature, ) .emit(); hir::TyKind::Err @@ -1392,7 +1390,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { ImplTraitContext::Disallowed(position) => { self.tcx.sess.emit_err(MisplacedImplTrait { span: t.span, - position: DiagnosticArgFromDisplay(&position), + position: DiagnosticArgFromDisplay(position), }); hir::TyKind::Err } @@ -1457,17 +1455,12 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { // frequently opened issues show. let opaque_ty_span = self.mark_span_with_reason(DesugaringKind::OpaqueTy, span, None); - let opaque_ty_def_id = match origin { - hir::OpaqueTyOrigin::TyAlias => self.create_def( - self.current_hir_id_owner.def_id, - opaque_ty_node_id, - DefPathData::ImplTrait, - ), - hir::OpaqueTyOrigin::FnReturn(fn_def_id) => { - self.create_def(fn_def_id, opaque_ty_node_id, DefPathData::ImplTrait) - } - hir::OpaqueTyOrigin::AsyncFn(..) => bug!("unreachable"), - }; + let opaque_ty_def_id = self.create_def( + self.current_hir_id_owner.def_id, + opaque_ty_node_id, + DefPathData::ImplTrait, + opaque_ty_span, + ); debug!(?opaque_ty_def_id); // Contains the new lifetime definitions created for the TAIT (if any). @@ -1521,6 +1514,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { hir::GenericParam { hir_id, + def_id: lctx.local_def_id(new_node_id), name, span: lifetime.ident.span, pure_wrt_drop: false, @@ -1559,15 +1553,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { let lifetimes = self.arena.alloc_from_iter(collected_lifetimes.into_iter().map(|(_, lifetime)| { let id = self.next_node_id(); - let span = lifetime.ident.span; - - let ident = if lifetime.ident.name == kw::UnderscoreLifetime { - Ident::with_dummy_span(kw::UnderscoreLifetime) - } else { - lifetime.ident - }; - - let l = self.new_named_lifetime(lifetime.id, id, span, ident); + let l = self.new_named_lifetime(lifetime.id, id, lifetime.ident); hir::GenericArg::Lifetime(l) })); debug!(?lifetimes); @@ -1627,6 +1613,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { parent_def_id, node_id, DefPathData::LifetimeNs(lifetime.ident.name), + lifetime.ident.span, ); remapping.insert(old_def_id, new_def_id); @@ -1643,6 +1630,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { parent_def_id, node_id, DefPathData::LifetimeNs(kw::UnderscoreLifetime), + lifetime.ident.span, ); remapping.insert(old_def_id, new_def_id); @@ -1692,7 +1680,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { fn lower_fn_decl( &mut self, decl: &FnDecl, - fn_node_id: Option<NodeId>, + fn_node_id: NodeId, fn_span: Span, kind: FnDeclKind, make_ret_async: Option<(NodeId, Span)>, @@ -1707,23 +1695,21 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { inputs = &inputs[..inputs.len() - 1]; } let inputs = self.arena.alloc_from_iter(inputs.iter().map(|param| { - if fn_node_id.is_some() { - self.lower_ty_direct(¶m.ty, &ImplTraitContext::Universal) + let itctx = if kind.param_impl_trait_allowed() { + ImplTraitContext::Universal } else { - self.lower_ty_direct( - ¶m.ty, - &ImplTraitContext::Disallowed(match kind { - FnDeclKind::Fn | FnDeclKind::Inherent => { - unreachable!("fn should allow in-band lifetimes") - } - FnDeclKind::ExternFn => ImplTraitPosition::ExternFnParam, - FnDeclKind::Closure => ImplTraitPosition::ClosureParam, - FnDeclKind::Pointer => ImplTraitPosition::PointerParam, - FnDeclKind::Trait => ImplTraitPosition::TraitParam, - FnDeclKind::Impl => ImplTraitPosition::ImplParam, - }), - ) - } + ImplTraitContext::Disallowed(match kind { + FnDeclKind::Fn | FnDeclKind::Inherent => { + unreachable!("fn should allow APIT") + } + FnDeclKind::ExternFn => ImplTraitPosition::ExternFnParam, + FnDeclKind::Closure => ImplTraitPosition::ClosureParam, + FnDeclKind::Pointer => ImplTraitPosition::PointerParam, + FnDeclKind::Trait => ImplTraitPosition::TraitParam, + FnDeclKind::Impl => ImplTraitPosition::ImplParam, + }) + }; + self.lower_ty_direct(¶m.ty, &itctx) })); let output = if let Some((ret_id, span)) = make_ret_async { @@ -1746,22 +1732,21 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { self.lower_async_fn_ret_ty( &decl.output, - fn_node_id.expect("`make_ret_async` but no `fn_def_id`"), + fn_node_id, ret_id, matches!(kind, FnDeclKind::Trait), ) } else { - match decl.output { - FnRetTy::Ty(ref ty) => { - let mut context = match fn_node_id { - Some(fn_node_id) if kind.impl_trait_allowed(self.tcx) => { - let fn_def_id = self.local_def_id(fn_node_id); - ImplTraitContext::ReturnPositionOpaqueTy { - origin: hir::OpaqueTyOrigin::FnReturn(fn_def_id), - in_trait: matches!(kind, FnDeclKind::Trait), - } + match &decl.output { + FnRetTy::Ty(ty) => { + let context = if kind.return_impl_trait_allowed(self.tcx) { + let fn_def_id = self.local_def_id(fn_node_id); + ImplTraitContext::ReturnPositionOpaqueTy { + origin: hir::OpaqueTyOrigin::FnReturn(fn_def_id), + in_trait: matches!(kind, FnDeclKind::Trait), } - _ => ImplTraitContext::Disallowed(match kind { + } else { + let position = match kind { FnDeclKind::Fn | FnDeclKind::Inherent => { unreachable!("fn should allow in-band lifetimes") } @@ -1770,11 +1755,18 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { FnDeclKind::Pointer => ImplTraitPosition::PointerReturn, FnDeclKind::Trait => ImplTraitPosition::TraitReturn, FnDeclKind::Impl => ImplTraitPosition::ImplReturn, - }), + }; + match kind { + FnDeclKind::Trait | FnDeclKind::Impl => ImplTraitContext::FeatureGated( + position, + sym::return_position_impl_trait_in_trait, + ), + _ => ImplTraitContext::Disallowed(position), + } }; - hir::FnRetTy::Return(self.lower_ty(ty, &mut context)) + hir::FnRetTy::Return(self.lower_ty(ty, &context)) } - FnRetTy::Default(span) => hir::FnRetTy::DefaultReturn(self.lower_span(span)), + FnRetTy::Default(span) => hir::FnRetTy::DefaultReturn(self.lower_span(*span)), } }; @@ -1782,26 +1774,23 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { inputs, output, c_variadic, + lifetime_elision_allowed: self.resolver.lifetime_elision_allowed.contains(&fn_node_id), implicit_self: decl.inputs.get(0).map_or(hir::ImplicitSelfKind::None, |arg| { let is_mutable_pat = matches!( arg.pat.kind, PatKind::Ident(hir::BindingAnnotation(_, Mutability::Mut), ..) ); - match arg.ty.kind { + match &arg.ty.kind { TyKind::ImplicitSelf if is_mutable_pat => hir::ImplicitSelfKind::Mut, TyKind::ImplicitSelf => hir::ImplicitSelfKind::Imm, // Given we are only considering `ImplicitSelf` types, we needn't consider // the case where we have a mutable pattern to a reference as that would // no longer be an `ImplicitSelf`. - TyKind::Rptr(_, ref mt) - if mt.ty.kind.is_implicit_self() && mt.mutbl == ast::Mutability::Mut => - { - hir::ImplicitSelfKind::MutRef - } - TyKind::Rptr(_, ref mt) if mt.ty.kind.is_implicit_self() => { - hir::ImplicitSelfKind::ImmRef - } + TyKind::Rptr(_, mt) if mt.ty.kind.is_implicit_self() => match mt.mutbl { + hir::Mutability::Not => hir::ImplicitSelfKind::ImmRef, + hir::Mutability::Mut => hir::ImplicitSelfKind::MutRef, + }, _ => hir::ImplicitSelfKind::None, } }), @@ -1828,9 +1817,11 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { let opaque_ty_span = self.mark_span_with_reason(DesugaringKind::Async, span, None); - let opaque_ty_def_id = self.local_def_id(opaque_ty_node_id); let fn_def_id = self.local_def_id(fn_node_id); + let opaque_ty_def_id = + self.create_def(fn_def_id, opaque_ty_node_id, DefPathData::ImplTrait, opaque_ty_span); + // When we create the opaque type for this async fn, it is going to have // to capture all the lifetimes involved in the signature (including in the // return type). This is done by introducing lifetime parameters for: @@ -1889,6 +1880,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { opaque_ty_def_id, inner_node_id, DefPathData::LifetimeNs(ident.name), + ident.span, ); new_remapping.insert(outer_def_id, inner_def_id); @@ -1953,7 +1945,10 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { output, span, if in_trait && !this.tcx.features().return_position_impl_trait_in_trait { - ImplTraitContext::Disallowed(ImplTraitPosition::TraitReturn) + ImplTraitContext::FeatureGated( + ImplTraitPosition::TraitReturn, + sym::return_position_impl_trait_in_trait, + ) } else { ImplTraitContext::ReturnPositionOpaqueTy { origin: hir::OpaqueTyOrigin::FnReturn(fn_def_id), @@ -1978,6 +1973,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { hir::GenericParam { hir_id, + def_id: this.local_def_id(new_node_id), name, span: lifetime.ident.span, pure_wrt_drop: false, @@ -2024,18 +2020,10 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { let generic_args = self.arena.alloc_from_iter(collected_lifetimes.into_iter().map( |(_, lifetime, res)| { let id = self.next_node_id(); - let span = lifetime.ident.span; - - let ident = if lifetime.ident.name == kw::UnderscoreLifetime { - Ident::with_dummy_span(kw::UnderscoreLifetime) - } else { - lifetime.ident - }; - let res = res.unwrap_or( self.resolver.get_lifetime_res(lifetime.id).unwrap_or(LifetimeRes::Error), ); - hir::GenericArg::Lifetime(self.new_named_lifetime_with_res(id, span, ident, res)) + hir::GenericArg::Lifetime(self.new_named_lifetime_with_res(id, lifetime.ident, res)) }, )); @@ -2105,43 +2093,40 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { } fn lower_lifetime(&mut self, l: &Lifetime) -> &'hir hir::Lifetime { - let span = self.lower_span(l.ident.span); let ident = self.lower_ident(l.ident); - self.new_named_lifetime(l.id, l.id, span, ident) + self.new_named_lifetime(l.id, l.id, ident) } #[instrument(level = "debug", skip(self))] fn new_named_lifetime_with_res( &mut self, id: NodeId, - span: Span, ident: Ident, res: LifetimeRes, ) -> &'hir hir::Lifetime { - let name = match res { + let res = match res { LifetimeRes::Param { param, .. } => { - let p_name = ParamName::Plain(ident); let param = self.get_remapped_def_id(param); - - hir::LifetimeName::Param(param, p_name) + hir::LifetimeName::Param(param) } LifetimeRes::Fresh { param, .. } => { - debug_assert_eq!(ident.name, kw::UnderscoreLifetime); let param = self.local_def_id(param); - - hir::LifetimeName::Param(param, ParamName::Fresh) + hir::LifetimeName::Param(param) } LifetimeRes::Infer => hir::LifetimeName::Infer, LifetimeRes::Static => hir::LifetimeName::Static, LifetimeRes::Error => hir::LifetimeName::Error, - res => panic!("Unexpected lifetime resolution {:?} for {:?} at {:?}", res, ident, span), + res => panic!( + "Unexpected lifetime resolution {:?} for {:?} at {:?}", + res, ident, ident.span + ), }; - debug!(?name); + debug!(?res); self.arena.alloc(hir::Lifetime { hir_id: self.lower_node_id(id), - span: self.lower_span(span), - name, + ident: self.lower_ident(ident), + res, }) } @@ -2150,11 +2135,10 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { &mut self, id: NodeId, new_id: NodeId, - span: Span, ident: Ident, ) -> &'hir hir::Lifetime { let res = self.resolver.get_lifetime_res(id).unwrap_or(LifetimeRes::Error); - self.new_named_lifetime_with_res(new_id, span, ident, res) + self.new_named_lifetime_with_res(new_id, ident, res) } fn lower_generic_params_mut<'s>( @@ -2176,6 +2160,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { self.lower_attrs(hir_id, ¶m.attrs); hir::GenericParam { hir_id, + def_id: self.local_def_id(param.id), name, span: self.lower_span(param.span()), pure_wrt_drop: self.tcx.sess.contains_name(¶m.attrs, sym::may_dangle), @@ -2188,7 +2173,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { &mut self, param: &GenericParam, ) -> (hir::ParamName, hir::GenericParamKind<'hir>) { - match param.kind { + match ¶m.kind { GenericParamKind::Lifetime => { // AST resolution emitted an error on those parameters, so we lower them using // `ParamName::Error`. @@ -2204,7 +2189,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { (param_name, kind) } - GenericParamKind::Type { ref default, .. } => { + GenericParamKind::Type { default, .. } => { let kind = hir::GenericParamKind::Type { default: default.as_ref().map(|x| { self.lower_ty(x, &ImplTraitContext::Disallowed(ImplTraitPosition::Type)) @@ -2214,7 +2199,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { (hir::ParamName::Plain(self.lower_ident(param.ident)), kind) } - GenericParamKind::Const { ref ty, kw_span: _, ref default } => { + GenericParamKind::Const { ty, kw_span: _, default } => { let ty = self.lower_ty(&ty, &ImplTraitContext::Disallowed(ImplTraitPosition::Type)); let default = default.as_ref().map(|def| self.lower_anon_const(def)); ( @@ -2280,6 +2265,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { // Set the name to `impl Bound1 + Bound2`. let param = hir::GenericParam { hir_id: self.lower_node_id(node_id), + def_id, name: ParamName::Plain(self.lower_ident(ident)), pure_wrt_drop: false, span: self.lower_span(span), @@ -2315,7 +2301,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { /// has no attributes and is not targeted by a `break`. fn lower_block_expr(&mut self, b: &Block) -> hir::Expr<'hir> { let block = self.lower_block(b, false); - self.expr_block(block, AttrVec::new()) + self.expr_block(block) } fn lower_array_length(&mut self, c: &AnonConst) -> hir::ArrayLen { @@ -2340,6 +2326,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { fn lower_anon_const(&mut self, c: &AnonConst) -> hir::AnonConst { self.with_new_scopes(|this| hir::AnonConst { + def_id: this.local_def_id(c.id), hir_id: this.lower_node_id(c.id), body: this.lower_const_body(c.value.span, Some(&c.value)), }) @@ -2563,8 +2550,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { fn elided_dyn_bound(&mut self, span: Span) -> &'hir hir::Lifetime { let r = hir::Lifetime { hir_id: self.next_id(), - span: self.lower_span(span), - name: hir::LifetimeName::ImplicitObjectLifetimeDefault, + ident: Ident::new(kw::Empty, self.lower_span(span)), + res: hir::LifetimeName::ImplicitObjectLifetimeDefault, }; debug!("elided_dyn_bound: r={:?}", r); self.arena.alloc(r) |