hir: Preserve used syntax in TyKind::TraitObject

Author: petrochenkov

compiler/rustc_ast/src/ast.rs

@@ -1964,7 +1964,7 @@ impl TyKind {
 }
 
 /// Syntax used to declare a trait object.
-#[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug)]
+#[derive(Clone, Copy, PartialEq, Encodable, Decodable, Debug, HashStable_Generic)]
 pub enum TraitObjectSyntax {
     Dyn,
     None,

compiler/rustc_ast_lowering/src/lib.rs

@@ -1396,7 +1396,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 if kind != TraitObjectSyntax::Dyn {
                     self.maybe_lint_bare_trait(t.span, t.id, false);
                 }
-                hir::TyKind::TraitObject(bounds, lifetime_bound)
+                hir::TyKind::TraitObject(bounds, lifetime_bound, kind)
             }
             TyKind::ImplTrait(def_node_id, ref bounds) => {
                 let span = t.span;
@@ -2648,6 +2648,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                         hir::TyKind::TraitObject(
                             arena_vec![self; principal],
                             self.elided_dyn_bound(span),
+                            TraitObjectSyntax::None,
                         )
                     }
                     _ => hir::TyKind::Path(hir::QPath::Resolved(None, path)),

compiler/rustc_hir/src/hir.rs

@@ -6,7 +6,7 @@ use crate::{itemlikevisit, LangItem};
 
 use rustc_ast::util::parser::ExprPrecedence;
 use rustc_ast::{self as ast, CrateSugar, LlvmAsmDialect};
-use rustc_ast::{Attribute, FloatTy, IntTy, Label, LitKind, StrStyle, UintTy};
+use rustc_ast::{Attribute, FloatTy, IntTy, Label, LitKind, StrStyle, TraitObjectSyntax, UintTy};
 pub use rustc_ast::{BorrowKind, ImplPolarity, IsAuto};
 pub use rustc_ast::{CaptureBy, Movability, Mutability};
 use rustc_ast::{InlineAsmOptions, InlineAsmTemplatePiece};
@@ -2327,7 +2327,7 @@ pub enum TyKind<'hir> {
     OpaqueDef(ItemId, &'hir [GenericArg<'hir>]),
     /// A trait object type `Bound1 + Bound2 + Bound3`
     /// where `Bound` is a trait or a lifetime.
-    TraitObject(&'hir [PolyTraitRef<'hir>], Lifetime),
+    TraitObject(&'hir [PolyTraitRef<'hir>], Lifetime, TraitObjectSyntax),
     /// Unused for now.
     Typeof(AnonConst),
     /// `TyKind::Infer` means the type should be inferred instead of it having been

compiler/rustc_hir/src/intravisit.rs

@@ -709,7 +709,7 @@ pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty<'v>) {
             visitor.visit_ty(ty);
             visitor.visit_anon_const(length)
         }
-        TyKind::TraitObject(bounds, ref lifetime) => {
+        TyKind::TraitObject(bounds, ref lifetime, _syntax) => {
             for bound in bounds {
                 visitor.visit_poly_trait_ref(bound, TraitBoundModifier::None);
             }

compiler/rustc_hir_pretty/src/lib.rs

@@ -410,7 +410,10 @@ impl<'a> State<'a> {
             }
             hir::TyKind::OpaqueDef(..) => self.s.word("/*impl Trait*/"),
             hir::TyKind::Path(ref qpath) => self.print_qpath(qpath, false),
-            hir::TyKind::TraitObject(bounds, ref lifetime) => {
+            hir::TyKind::TraitObject(bounds, ref lifetime, syntax) => {
+                if syntax == ast::TraitObjectSyntax::Dyn {
+                    self.word_space("dyn");
+                }
                 let mut first = true;
                 for bound in bounds {
                     if first {

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/find_anon_type.rs

@@ -99,7 +99,7 @@ impl Visitor<'tcx> for FindNestedTypeVisitor<'tcx> {
                 return;
             }
 
-            hir::TyKind::TraitObject(bounds, _) => {
+            hir::TyKind::TraitObject(bounds, ..) => {
                 for bound in bounds {
                     self.current_index.shift_in(1);
                     self.visit_poly_trait_ref(bound, hir::TraitBoundModifier::None);

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs

@@ -292,7 +292,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
                         );
                     }
                 }
-                TyKind::TraitObject(_, lt) => match lt.name {
+                TyKind::TraitObject(_, lt, _) => match lt.name {
                     LifetimeName::ImplicitObjectLifetimeDefault => {
                         err.span_suggestion_verbose(
                             fn_return.span.shrink_to_hi(),
@@ -498,6 +498,7 @@ impl<'tcx> Visitor<'tcx> for HirTraitObjectVisitor {
         if let TyKind::TraitObject(
             poly_trait_refs,
             Lifetime { name: LifetimeName::ImplicitObjectLifetimeDefault, .. },
+            _,
         ) = t.kind
         {
             for ptr in poly_trait_refs {

compiler/rustc_middle/src/ty/diagnostics.rs

@@ -314,6 +314,7 @@ impl<'v> hir::intravisit::Visitor<'v> for TraitObjectVisitor<'v> {
                         hir::LifetimeName::ImplicitObjectLifetimeDefault | hir::LifetimeName::Static,
                     ..
                 },
+                _,
             ) => {
                 self.0.push(ty);
             }

compiler/rustc_resolve/src/late/lifetimes.rs

@@ -540,7 +540,7 @@ impl<'a, 'tcx> Visitor<'tcx> for LifetimeContext<'a, 'tcx> {
                 self.missing_named_lifetime_spots.pop();
                 self.is_in_fn_syntax = was_in_fn_syntax;
             }
-            hir::TyKind::TraitObject(bounds, ref lifetime) => {
+            hir::TyKind::TraitObject(bounds, ref lifetime, _) => {
                 debug!("visit_ty: TraitObject(bounds={:?}, lifetime={:?})", bounds, lifetime);
                 for bound in bounds {
                     self.visit_poly_trait_ref(bound, hir::TraitBoundModifier::None);
@@ -2299,7 +2299,7 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                     self.outer_index.shift_in(1);
                 }
                 match ty.kind {
-                    hir::TyKind::TraitObject(bounds, ref lifetime) => {
+                    hir::TyKind::TraitObject(bounds, ref lifetime, _) => {
                         for bound in bounds {
                             self.visit_poly_trait_ref(bound, hir::TraitBoundModifier::None);
                         }

compiler/rustc_typeck/src/astconv/mod.rs

@@ -2201,7 +2201,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
                     Some(ast_ty),
                 ))
             }
-            hir::TyKind::TraitObject(ref bounds, ref lifetime) => {
+            hir::TyKind::TraitObject(ref bounds, ref lifetime, _) => {
                 self.conv_object_ty_poly_trait_ref(ast_ty.span, bounds, lifetime, borrowed)
             }
             hir::TyKind::Path(hir::QPath::Resolved(ref maybe_qself, ref path)) => {