diff options
Diffstat (limited to 'compiler/rustc_ast_lowering/src/lib.rs')
| -rw-r--r-- | compiler/rustc_ast_lowering/src/lib.rs | 66 |
1 files changed, 44 insertions, 22 deletions
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs index bac3f974cca..8438a421226 100644 --- a/compiler/rustc_ast_lowering/src/lib.rs +++ b/compiler/rustc_ast_lowering/src/lib.rs @@ -41,7 +41,6 @@ // tidy-alphabetical-end use rustc_ast::node_id::NodeMap; -use rustc_ast::ptr::P; use rustc_ast::{self as ast, *}; use rustc_data_structures::captures::Captures; use rustc_data_structures::fingerprint::Fingerprint; @@ -59,8 +58,7 @@ use rustc_macros::extension; use rustc_middle::span_bug; use rustc_middle::ty::{ResolverAstLowering, TyCtxt}; use rustc_session::parse::{add_feature_diagnostics, feature_err}; -use rustc_span::symbol::{Ident, Symbol, kw, sym}; -use rustc_span::{DUMMY_SP, DesugaringKind, Span}; +use rustc_span::{DUMMY_SP, DesugaringKind, Ident, Span, Symbol, kw, sym}; use smallvec::{SmallVec, smallvec}; use thin_vec::ThinVec; use tracing::{debug, instrument, trace}; @@ -96,7 +94,7 @@ struct LoweringContext<'a, 'hir> { /// Bodies inside the owner being lowered. bodies: Vec<(hir::ItemLocalId, &'hir hir::Body<'hir>)>, /// Attributes inside the owner being lowered. - attrs: SortedMap<hir::ItemLocalId, &'hir [Attribute]>, + attrs: SortedMap<hir::ItemLocalId, &'hir [hir::Attribute]>, /// Collect items that were created by lowering the current owner. children: Vec<(LocalDefId, hir::MaybeOwner<'hir>)>, @@ -260,6 +258,13 @@ enum ImplTraitContext { /// equivalent to a new opaque type like `type T = impl Debug; fn foo() -> T`. /// OpaqueTy { origin: hir::OpaqueTyOrigin<LocalDefId> }, + + /// Treat `impl Trait` as a "trait ascription", which is like a type + /// variable but that also enforces that a set of trait goals hold. + /// + /// This is useful to guide inference for unnameable types. + InBinding, + /// `impl Trait` is unstably accepted in this position. FeatureGated(ImplTraitPosition, Symbol), /// `impl Trait` is not accepted in this position. @@ -840,7 +845,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { ret } - fn lower_attrs(&mut self, id: HirId, attrs: &[Attribute]) -> &'hir [Attribute] { + fn lower_attrs(&mut self, id: HirId, attrs: &[Attribute]) -> &'hir [hir::Attribute] { if attrs.is_empty() { &[] } else { @@ -852,25 +857,33 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { } } - fn lower_attr(&self, attr: &Attribute) -> Attribute { + fn lower_attr(&self, attr: &Attribute) -> hir::Attribute { // Note that we explicitly do not walk the path. Since we don't really // lower attributes (we use the AST version) there is nowhere to keep // the `HirId`s. We don't actually need HIR version of attributes anyway. // Tokens are also not needed after macro expansion and parsing. let kind = match attr.kind { - AttrKind::Normal(ref normal) => AttrKind::Normal(P(NormalAttr { - item: AttrItem { - unsafety: normal.item.unsafety, - path: normal.item.path.clone(), - args: self.lower_attr_args(&normal.item.args), - tokens: None, + AttrKind::Normal(ref normal) => hir::AttrKind::Normal(Box::new(hir::AttrItem { + unsafety: self.lower_safety(normal.item.unsafety, hir::Safety::Safe), + path: hir::AttrPath { + segments: normal + .item + .path + .segments + .iter() + .map(|i| i.ident) + .collect::<Vec<_>>() + .into_boxed_slice(), + span: normal.item.path.span, }, - tokens: None, + args: self.lower_attr_args(&normal.item.args), })), - AttrKind::DocComment(comment_kind, data) => AttrKind::DocComment(comment_kind, data), + AttrKind::DocComment(comment_kind, data) => { + hir::AttrKind::DocComment(comment_kind, data) + } }; - Attribute { kind, id: attr.id, style: attr.style, span: self.lower_span(attr.span) } + hir::Attribute { kind, id: attr.id, style: attr.style, span: self.lower_span(attr.span) } } fn alias_attrs(&mut self, id: HirId, target_id: HirId) { @@ -882,15 +895,14 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { } } - fn lower_attr_args(&self, args: &AttrArgs) -> AttrArgs { + fn lower_attr_args(&self, args: &AttrArgs) -> hir::AttrArgs { match args { - AttrArgs::Empty => AttrArgs::Empty, - AttrArgs::Delimited(args) => AttrArgs::Delimited(self.lower_delim_args(args)), + AttrArgs::Empty => hir::AttrArgs::Empty, + AttrArgs::Delimited(args) => hir::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]`). - &AttrArgs::Eq { eq_span, ref value } => { - let expr = value.unwrap_ast(); + &AttrArgs::Eq { eq_span, ref 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(token_lit) = expr.kind @@ -906,7 +918,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { span: DUMMY_SP, } }; - AttrArgs::Eq { eq_span, value: AttrArgsEq::Hir(lit) } + hir::AttrArgs::Eq { eq_span, expr: lit } } } } @@ -1228,6 +1240,13 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { param_names: self.lower_fn_params_to_names(&f.decl), })) } + TyKind::UnsafeBinder(f) => { + let generic_params = self.lower_lifetime_binder(t.id, &f.generic_params); + hir::TyKind::UnsafeBinder(self.arena.alloc(hir::UnsafeBinderTy { + generic_params, + inner_ty: self.lower_ty(&f.inner_ty, itctx), + })) + } TyKind::Never => hir::TyKind::Never, TyKind::Tup(tys) => hir::TyKind::Tup( self.arena.alloc_from_iter(tys.iter().map(|ty| self.lower_ty_direct(ty, itctx))), @@ -1320,6 +1339,9 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { } path } + ImplTraitContext::InBinding => { + hir::TyKind::TraitAscription(self.lower_param_bounds(bounds, itctx)) + } ImplTraitContext::FeatureGated(position, feature) => { let guar = self .tcx @@ -2184,7 +2206,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> { fn stmt_let_pat( &mut self, - attrs: Option<&'hir [Attribute]>, + attrs: Option<&'hir [hir::Attribute]>, span: Span, init: Option<&'hir hir::Expr<'hir>>, pat: &'hir hir::Pat<'hir>, |