Auto merge of #51815 - oli-obk:lowering_cleanups2, r=nikomatsakis

Lowering cleanups [2/N]

Double indirections are unnecessary

src/librustc/hir/lowering.rs

@@ -1074,11 +1074,15 @@ impl<'a> LoweringContext<'a> {
                         -> hir::GenericArg {
         match arg {
             ast::GenericArg::Lifetime(lt) => GenericArg::Lifetime(self.lower_lifetime(&lt)),
-            ast::GenericArg::Type(ty) => GenericArg::Type(self.lower_ty(&ty, itctx)),
+            ast::GenericArg::Type(ty) => GenericArg::Type(self.lower_ty_direct(&ty, itctx)),
         }
     }
 
     fn lower_ty(&mut self, t: &Ty, itctx: ImplTraitContext) -> P<hir::Ty> {
+        P(self.lower_ty_direct(t, itctx))
+    }
+
+    fn lower_ty_direct(&mut self, t: &Ty, itctx: ImplTraitContext) -> hir::Ty {
         let kind = match t.node {
             TyKind::Infer => hir::TyInfer,
             TyKind::Err => hir::TyErr,
@@ -1115,10 +1119,10 @@ impl<'a> LoweringContext<'a> {
             ),
             TyKind::Never => hir::TyNever,
             TyKind::Tup(ref tys) => {
-                hir::TyTup(tys.iter().map(|ty| self.lower_ty(ty, itctx)).collect())
+                hir::TyTup(tys.iter().map(|ty| self.lower_ty_direct(ty, itctx)).collect())
             }
             TyKind::Paren(ref ty) => {
-                return self.lower_ty(ty, itctx);
+                return self.lower_ty_direct(ty, itctx);
             }
             TyKind::Path(ref qself, ref path) => {
                 let id = self.lower_node_id(t.id);
@@ -1228,12 +1232,12 @@ impl<'a> LoweringContext<'a> {
         };
 
         let LoweredNodeId { node_id, hir_id } = self.lower_node_id(t.id);
-        P(hir::Ty {
+        hir::Ty {
             id: node_id,
             node: kind,
             span: t.span,
             hir_id,
-        })
+        }
     }
 
     fn lower_existential_impl_trait(
@@ -1636,7 +1640,7 @@ impl<'a> LoweringContext<'a> {
             // e.g. `Vec` in `Vec::new` or `<I as Iterator>::Item` in
             // `<I as Iterator>::Item::default`.
             let new_id = self.next_id();
-            self.ty_path(new_id, p.span, hir::QPath::Resolved(qself, path))
+            P(self.ty_path(new_id, p.span, hir::QPath::Resolved(qself, path)))
         };
 
         // Anything after the base path are associated "extensions",
@@ -1667,7 +1671,7 @@ impl<'a> LoweringContext<'a> {
 
             // Wrap the associated extension in another type node.
             let new_id = self.next_id();
-            ty = self.ty_path(new_id, p.span, qpath);
+            ty = P(self.ty_path(new_id, p.span, qpath));
         }
 
         // Should've returned in the for loop above.
@@ -1802,10 +1806,10 @@ impl<'a> LoweringContext<'a> {
             |this| {
                 const DISALLOWED: ImplTraitContext = ImplTraitContext::Disallowed;
                 let &ParenthesisedArgs { ref inputs, ref output, span } = data;
-                let inputs = inputs.iter().map(|ty| this.lower_ty(ty, DISALLOWED)).collect();
+                let inputs = inputs.iter().map(|ty| this.lower_ty_direct(ty, DISALLOWED)).collect();
                 let mk_tup = |this: &mut Self, tys, span| {
                     let LoweredNodeId { node_id, hir_id } = this.next_id();
-                    P(hir::Ty { node: hir::TyTup(tys), id: node_id, hir_id, span })
+                    hir::Ty { node: hir::TyTup(tys), id: node_id, hir_id, span }
                 };
 
                 (
@@ -1818,7 +1822,7 @@ impl<'a> LoweringContext<'a> {
                                 ty: output
                                     .as_ref()
                                     .map(|ty| this.lower_ty(&ty, DISALLOWED))
-                                    .unwrap_or_else(|| mk_tup(this, hir::HirVec::new(), span)),
+                                    .unwrap_or_else(|| P(mk_tup(this, hir::HirVec::new(), span))),
                                 span: output.as_ref().map_or(span, |ty| ty.span),
                             }
                         ],
@@ -1894,9 +1898,9 @@ impl<'a> LoweringContext<'a> {
             .iter()
             .map(|arg| {
                 if let Some(def_id) = fn_def_id {
-                    self.lower_ty(&arg.ty, ImplTraitContext::Universal(def_id))
+                    self.lower_ty_direct(&arg.ty, ImplTraitContext::Universal(def_id))
                 } else {
-                    self.lower_ty(&arg.ty, ImplTraitContext::Disallowed)
+                    self.lower_ty_direct(&arg.ty, ImplTraitContext::Disallowed)
                 }
             })
             .collect::<HirVec<_>>();
@@ -1936,7 +1940,7 @@ impl<'a> LoweringContext<'a> {
     // fn_def_id: DefId of the parent function. Used to create child impl trait definition.
     fn lower_async_fn_ret_ty(
         &mut self,
-        inputs: &[P<hir::Ty>],
+        inputs: &[hir::Ty],
         output: &FunctionRetTy,
         fn_def_id: DefId,
     ) -> hir::FunctionRetTy {
@@ -3661,7 +3665,7 @@ impl<'a> LoweringContext<'a> {
                 let e1 = self.lower_expr(e1);
                 let e2 = self.lower_expr(e2);
                 let ty_path = P(self.std_path(span, &["ops", "RangeInclusive"], None, false));
-                let ty = self.ty_path(id, span, hir::QPath::Resolved(None, ty_path));
+                let ty = P(self.ty_path(id, span, hir::QPath::Resolved(None, ty_path)));
                 let new_seg = P(hir::PathSegment::from_name(Symbol::intern("new")));
                 let new_path = hir::QPath::TypeRelative(ty, new_seg);
                 let new = P(self.expr(span, hir::ExprPath(new_path), ThinVec::new()));
@@ -4549,7 +4553,7 @@ impl<'a> LoweringContext<'a> {
             .resolve_str_path(span, self.crate_root, components, params, is_value)
     }
 
-    fn ty_path(&mut self, id: LoweredNodeId, span: Span, qpath: hir::QPath) -> P<hir::Ty> {
+    fn ty_path(&mut self, id: LoweredNodeId, span: Span, qpath: hir::QPath) -> hir::Ty {
         let mut id = id;
         let node = match qpath {
             hir::QPath::Resolved(None, path) => {
@@ -4574,12 +4578,12 @@ impl<'a> LoweringContext<'a> {
             }
             _ => hir::TyPath(qpath),
         };
-        P(hir::Ty {
+        hir::Ty {
             id: id.node_id,
             hir_id: id.hir_id,
             node,
             span,
-        })
+        }
     }
 
     /// Invoked to create the lifetime argument for a type `&T`

src/librustc/hir/mod.rs

@@ -383,7 +383,7 @@ impl PathSegment {
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum GenericArg {
     Lifetime(Lifetime),
-    Type(P<Ty>),
+    Type(Ty),
 }
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
@@ -412,7 +412,7 @@ impl GenericArgs {
         self.args.is_empty() && self.bindings.is_empty() && !self.parenthesized
     }
 
-    pub fn inputs(&self) -> &[P<Ty>] {
+    pub fn inputs(&self) -> &[Ty] {
         if self.parenthesized {
             for arg in &self.args {
                 match arg {
@@ -1658,7 +1658,7 @@ pub enum Ty_ {
     /// The never type (`!`)
     TyNever,
     /// A tuple (`(A, B, C, D,...)`)
-    TyTup(HirVec<P<Ty>>),
+    TyTup(HirVec<Ty>),
     /// A path to a type definition (`module::module::...::Type`), or an
     /// associated type, e.g. `<Vec<T> as Trait>::Type` or `<T>::Target`.
     ///
@@ -1719,7 +1719,7 @@ pub struct Arg {
 /// Represents the header (not the body) of a function declaration
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub struct FnDecl {
-    pub inputs: HirVec<P<Ty>>,
+    pub inputs: HirVec<Ty>,
     pub output: FunctionRetTy,
     pub variadic: bool,
     /// True if this function has an `self`, `&self` or `&mut self` receiver

src/librustc/middle/resolve_lifetime.rs

@@ -1792,7 +1792,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
 
     fn visit_fn_like_elision(
         &mut self,
-        inputs: &'tcx [P<hir::Ty>],
+        inputs: &'tcx [hir::Ty],
         output: Option<&'tcx P<hir::Ty>>,
     ) {
         debug!("visit_fn_like_elision: enter");

src/librustc/traits/error_reporting.rs

@@ -963,7 +963,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                 ..
             }) => {
                 (self.tcx.sess.codemap().def_span(span), decl.inputs.iter()
-                        .map(|arg| match arg.clone().into_inner().node {
+                        .map(|arg| match arg.clone().node {
                     hir::TyTup(ref tys) => ArgKind::Tuple(
                         Some(arg.span),
                         tys.iter()

src/librustdoc/clean/auto_trait.rs

@@ -263,7 +263,7 @@ impl<'a, 'tcx, 'rcx> AutoTraitFinder<'a, 'tcx, 'rcx> {
                     }));
                 }
                 ty::GenericParamDefKind::Type {..} => {
-                    args.push(hir::GenericArg::Type(P(self.ty_param_to_ty(param.clone()))));
+                    args.push(hir::GenericArg::Type(self.ty_param_to_ty(param.clone())));
                 }
             }
         }

src/librustdoc/clean/mod.rs

@@ -2150,7 +2150,7 @@ pub struct Arguments {
     pub values: Vec<Argument>,
 }
 
-impl<'a> Clean<Arguments> for (&'a [P<hir::Ty>], &'a [Spanned<ast::Name>]) {
+impl<'a> Clean<Arguments> for (&'a [hir::Ty], &'a [Spanned<ast::Name>]) {
     fn clean(&self, cx: &DocContext) -> Arguments {
         Arguments {
             values: self.0.iter().enumerate().map(|(i, ty)| {
@@ -2168,7 +2168,7 @@ impl<'a> Clean<Arguments> for (&'a [P<hir::Ty>], &'a [Spanned<ast::Name>]) {
     }
 }
 
-impl<'a> Clean<Arguments> for (&'a [P<hir::Ty>], hir::BodyId) {
+impl<'a> Clean<Arguments> for (&'a [hir::Ty], hir::BodyId) {
     fn clean(&self, cx: &DocContext) -> Arguments {
         let body = cx.tcx.hir.body(self.1);
 
@@ -2184,7 +2184,7 @@ impl<'a> Clean<Arguments> for (&'a [P<hir::Ty>], hir::BodyId) {
 }
 
 impl<'a, A: Copy> Clean<FnDecl> for (&'a hir::FnDecl, A)
-    where (&'a [P<hir::Ty>], A): Clean<Arguments>
+    where (&'a [hir::Ty], A): Clean<Arguments>
 {
     fn clean(&self, cx: &DocContext) -> FnDecl {
         FnDecl {
@@ -2926,7 +2926,7 @@ impl Clean<Type> for hir::Ty {
                                         }
                                     });
                                     if let Some(ty) = type_.cloned() {
-                                        ty_substs.insert(ty_param_def, ty.into_inner().clean(cx));
+                                        ty_substs.insert(ty_param_def, ty.clean(cx));
                                     } else if let Some(default) = default.clone() {
                                         ty_substs.insert(ty_param_def,
                                                          default.into_inner().clean(cx));