Auto merge of #101709 - nnethercote:simplify-visitors-more, r=cjgillot

Simplify visitors more

A successor to #100392.

r? `@cjgillot`

compiler/rustc_ast/src/visit.rs

@@ -156,8 +156,8 @@ pub trait Visitor<'ast>: Sized {
     fn visit_where_predicate(&mut self, p: &'ast WherePredicate) {
         walk_where_predicate(self, p)
     }
-    fn visit_fn(&mut self, fk: FnKind<'ast>, s: Span, _: NodeId) {
-        walk_fn(self, fk, s)
+    fn visit_fn(&mut self, fk: FnKind<'ast>, _: Span, _: NodeId) {
+        walk_fn(self, fk)
     }
     fn visit_assoc_item(&mut self, i: &'ast AssocItem, ctxt: AssocCtxt) {
         walk_assoc_item(self, i, ctxt)
@@ -201,11 +201,11 @@ pub trait Visitor<'ast>: Sized {
     fn visit_use_tree(&mut self, use_tree: &'ast UseTree, id: NodeId, _nested: bool) {
         walk_use_tree(self, use_tree, id)
     }
-    fn visit_path_segment(&mut self, path_span: Span, path_segment: &'ast PathSegment) {
-        walk_path_segment(self, path_span, path_segment)
+    fn visit_path_segment(&mut self, path_segment: &'ast PathSegment) {
+        walk_path_segment(self, path_segment)
     }
-    fn visit_generic_args(&mut self, path_span: Span, generic_args: &'ast GenericArgs) {
-        walk_generic_args(self, path_span, generic_args)
+    fn visit_generic_args(&mut self, generic_args: &'ast GenericArgs) {
+        walk_generic_args(self, generic_args)
     }
     fn visit_generic_arg(&mut self, generic_arg: &'ast GenericArg) {
         walk_generic_arg(self, generic_arg)
@@ -435,7 +435,7 @@ pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) {
 
 pub fn walk_path<'a, V: Visitor<'a>>(visitor: &mut V, path: &'a Path) {
     for segment in &path.segments {
-        visitor.visit_path_segment(path.span, segment);
+        visitor.visit_path_segment(segment);
     }
 }
 
@@ -457,18 +457,14 @@ pub fn walk_use_tree<'a, V: Visitor<'a>>(visitor: &mut V, use_tree: &'a UseTree,
     }
 }
 
-pub fn walk_path_segment<'a, V: Visitor<'a>>(
-    visitor: &mut V,
-    path_span: Span,
-    segment: &'a PathSegment,
-) {
+pub fn walk_path_segment<'a, V: Visitor<'a>>(visitor: &mut V, segment: &'a PathSegment) {
     visitor.visit_ident(segment.ident);
     if let Some(ref args) = segment.args {
-        visitor.visit_generic_args(path_span, args);
+        visitor.visit_generic_args(args);
     }
 }
 
-pub fn walk_generic_args<'a, V>(visitor: &mut V, _path_span: Span, generic_args: &'a GenericArgs)
+pub fn walk_generic_args<'a, V>(visitor: &mut V, generic_args: &'a GenericArgs)
 where
     V: Visitor<'a>,
 {
@@ -502,7 +498,7 @@ where
 pub fn walk_assoc_constraint<'a, V: Visitor<'a>>(visitor: &mut V, constraint: &'a AssocConstraint) {
     visitor.visit_ident(constraint.ident);
     if let Some(ref gen_args) = constraint.gen_args {
-        visitor.visit_generic_args(gen_args.span(), gen_args);
+        visitor.visit_generic_args(gen_args);
     }
     match constraint.kind {
         AssocConstraintKind::Equality { ref term } => match term {
@@ -659,7 +655,7 @@ pub fn walk_fn_decl<'a, V: Visitor<'a>>(visitor: &mut V, function_declaration: &
     visitor.visit_fn_ret_ty(&function_declaration.output);
 }
 
-pub fn walk_fn<'a, V: Visitor<'a>>(visitor: &mut V, kind: FnKind<'a>, _span: Span) {
+pub fn walk_fn<'a, V: Visitor<'a>>(visitor: &mut V, kind: FnKind<'a>) {
     match kind {
         FnKind::Fn(_, _, sig, _, generics, body) => {
             visitor.visit_generics(generics);
@@ -800,7 +796,7 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
             walk_list!(visitor, visit_expr, arguments);
         }
         ExprKind::MethodCall(ref segment, ref receiver, ref arguments, _span) => {
-            visitor.visit_path_segment(expression.span, segment);
+            visitor.visit_path_segment(segment);
             visitor.visit_expr(receiver);
             walk_list!(visitor, visit_expr, arguments);
         }

compiler/rustc_ast_lowering/src/index.rs

@@ -246,9 +246,9 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         });
     }
 
-    fn visit_path_segment(&mut self, path_span: Span, path_segment: &'hir PathSegment<'hir>) {
-        self.insert(path_span, path_segment.hir_id, Node::PathSegment(path_segment));
-        intravisit::walk_path_segment(self, path_span, path_segment);
+    fn visit_path_segment(&mut self, path_segment: &'hir PathSegment<'hir>) {
+        self.insert(path_segment.ident.span, path_segment.hir_id, Node::PathSegment(path_segment));
+        intravisit::walk_path_segment(self, path_segment);
     }
 
     fn visit_ty(&mut self, ty: &'hir Ty<'hir>) {
@@ -280,12 +280,12 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         fk: intravisit::FnKind<'hir>,
         fd: &'hir FnDecl<'hir>,
         b: BodyId,
-        s: Span,
+        _: Span,
         id: HirId,
     ) {
         assert_eq!(self.owner, id.owner);
         assert_eq!(self.parent_node, id.local_id);
-        intravisit::walk_fn(self, fk, fd, b, s, id);
+        intravisit::walk_fn(self, fk, fd, b, id);
     }
 
     fn visit_block(&mut self, block: &'hir Block<'hir>) {

compiler/rustc_ast_lowering/src/lifetime_collector.rs

@@ -63,9 +63,9 @@ impl<'ast> Visitor<'ast> for LifetimeCollectVisitor<'ast> {
         self.record_lifetime_use(*lifetime);
     }
 
-    fn visit_path_segment(&mut self, path_span: Span, path_segment: &'ast PathSegment) {
-        self.record_elided_anchor(path_segment.id, path_span);
-        visit::walk_path_segment(self, path_span, path_segment);
+    fn visit_path_segment(&mut self, path_segment: &'ast PathSegment) {
+        self.record_elided_anchor(path_segment.id, path_segment.ident.span);
+        visit::walk_path_segment(self, path_segment);
     }
 
     fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef) {

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -223,11 +223,9 @@ impl<'a> AstValidator<'a> {
                 for (i, segment) in path.segments.iter().enumerate() {
                     // Allow `impl Trait` iff we're on the final path segment
                     if i == path.segments.len() - 1 {
-                        self.visit_path_segment(path.span, segment);
+                        self.visit_path_segment(segment);
                     } else {
-                        self.with_banned_impl_trait(|this| {
-                            this.visit_path_segment(path.span, segment)
-                        });
+                        self.with_banned_impl_trait(|this| this.visit_path_segment(segment));
                     }
                 }
             }
@@ -1293,7 +1291,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
     }
 
     // Mirrors `visit::walk_generic_args`, but tracks relevant state.
-    fn visit_generic_args(&mut self, _: Span, generic_args: &'a GenericArgs) {
+    fn visit_generic_args(&mut self, generic_args: &'a GenericArgs) {
         match *generic_args {
             GenericArgs::AngleBracketed(ref data) => {
                 self.check_generic_args_before_constraints(data);
@@ -1529,7 +1527,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
             matches!(fk.header(), Some(FnHeader { constness: Const::Yes(_), .. }))
                 || matches!(fk.ctxt(), Some(FnCtxt::Assoc(_)));
 
-        self.with_tilde_const(tilde_const_allowed, |this| visit::walk_fn(this, fk, span));
+        self.with_tilde_const(tilde_const_allowed, |this| visit::walk_fn(this, fk));
     }
 
     fn visit_assoc_item(&mut self, item: &'a AssocItem, ctxt: AssocCtxt) {

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -680,7 +680,7 @@ impl<'a> Visitor<'a> for PostExpansionVisitor<'a> {
             gate_feature_post!(&self, c_variadic, span, "C-variadic functions are unstable");
         }
 
-        visit::walk_fn(self, fn_kind, span)
+        visit::walk_fn(self, fn_kind)
     }
 
     fn visit_assoc_constraint(&mut self, constraint: &'a AssocConstraint) {

compiler/rustc_ast_passes/src/node_count.rs

@@ -63,9 +63,9 @@ impl<'ast> Visitor<'ast> for NodeCounter {
         self.count += 1;
         walk_generics(self, g)
     }
-    fn visit_fn(&mut self, fk: visit::FnKind<'_>, s: Span, _: NodeId) {
+    fn visit_fn(&mut self, fk: visit::FnKind<'_>, _: Span, _: NodeId) {
         self.count += 1;
-        walk_fn(self, fk, s)
+        walk_fn(self, fk)
     }
     fn visit_assoc_item(&mut self, ti: &AssocItem, ctxt: AssocCtxt) {
         self.count += 1;
@@ -115,9 +115,9 @@ impl<'ast> Visitor<'ast> for NodeCounter {
         self.count += 1;
         walk_use_tree(self, use_tree, id)
     }
-    fn visit_generic_args(&mut self, path_span: Span, generic_args: &GenericArgs) {
+    fn visit_generic_args(&mut self, generic_args: &GenericArgs) {
         self.count += 1;
-        walk_generic_args(self, path_span, generic_args)
+        walk_generic_args(self, generic_args)
     }
     fn visit_assoc_constraint(&mut self, constraint: &AssocConstraint) {
         self.count += 1;

compiler/rustc_hir/src/intravisit.rs

@@ -298,7 +298,7 @@ pub trait Visitor<'v>: Sized {
     fn visit_id(&mut self, _hir_id: HirId) {
         // Nothing to do.
     }
-    fn visit_name(&mut self, _span: Span, _name: Symbol) {
+    fn visit_name(&mut self, _name: Symbol) {
         // Nothing to do.
     }
     fn visit_ident(&mut self, ident: Ident) {
@@ -361,8 +361,8 @@ pub trait Visitor<'v>: Sized {
     fn visit_fn_decl(&mut self, fd: &'v FnDecl<'v>) {
         walk_fn_decl(self, fd)
     }
-    fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl<'v>, b: BodyId, s: Span, id: HirId) {
-        walk_fn(self, fk, fd, b, s, id)
+    fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl<'v>, b: BodyId, _: Span, id: HirId) {
+        walk_fn(self, fk, fd, b, id)
     }
     fn visit_use(&mut self, path: &'v Path<'v>, hir_id: HirId) {
         walk_use(self, path, hir_id)
@@ -388,8 +388,8 @@ pub trait Visitor<'v>: Sized {
     fn visit_param_bound(&mut self, bounds: &'v GenericBound<'v>) {
         walk_param_bound(self, bounds)
     }
-    fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef<'v>, m: TraitBoundModifier) {
-        walk_poly_trait_ref(self, t, m)
+    fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef<'v>) {
+        walk_poly_trait_ref(self, t)
     }
     fn visit_variant_data(&mut self, s: &'v VariantData<'v>) {
         walk_struct_def(self, s)
@@ -420,17 +420,18 @@ pub trait Visitor<'v>: Sized {
     fn visit_lifetime(&mut self, lifetime: &'v Lifetime) {
         walk_lifetime(self, lifetime)
     }
-    fn visit_qpath(&mut self, qpath: &'v QPath<'v>, id: HirId, span: Span) {
-        walk_qpath(self, qpath, id, span)
+    // The span is that of the surrounding type/pattern/expr/whatever.
+    fn visit_qpath(&mut self, qpath: &'v QPath<'v>, id: HirId, _span: Span) {
+        walk_qpath(self, qpath, id)
     }
     fn visit_path(&mut self, path: &'v Path<'v>, _id: HirId) {
         walk_path(self, path)
     }
-    fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment<'v>) {
-        walk_path_segment(self, path_span, path_segment)
+    fn visit_path_segment(&mut self, path_segment: &'v PathSegment<'v>) {
+        walk_path_segment(self, path_segment)
     }
-    fn visit_generic_args(&mut self, path_span: Span, generic_args: &'v GenericArgs<'v>) {
-        walk_generic_args(self, path_span, generic_args)
+    fn visit_generic_args(&mut self, generic_args: &'v GenericArgs<'v>) {
+        walk_generic_args(self, generic_args)
     }
     fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding<'v>) {
         walk_assoc_type_binding(self, type_binding)
@@ -472,7 +473,7 @@ pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local<'v>) {
 }
 
 pub fn walk_ident<'v, V: Visitor<'v>>(visitor: &mut V, ident: Ident) {
-    visitor.visit_name(ident.span, ident.name);
+    visitor.visit_name(ident.name);
 }
 
 pub fn walk_label<'v, V: Visitor<'v>>(visitor: &mut V, label: &'v Label) {
@@ -494,11 +495,7 @@ pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime
     }
 }
 
-pub fn walk_poly_trait_ref<'v, V: Visitor<'v>>(
-    visitor: &mut V,
-    trait_ref: &'v PolyTraitRef<'v>,
-    _modifier: TraitBoundModifier,
-) {
+pub fn walk_poly_trait_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_ref: &'v PolyTraitRef<'v>) {
     walk_list!(visitor, visit_generic_param, trait_ref.bound_generic_params);
     visitor.visit_trait_ref(&trait_ref.trait_ref);
 }
@@ -519,7 +516,7 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) {
         ItemKind::ExternCrate(orig_name) => {
             visitor.visit_id(item.hir_id());
             if let Some(orig_name) = orig_name {
-                visitor.visit_name(item.span, orig_name);
+                visitor.visit_name(orig_name);
             }
         }
         ItemKind::Use(ref path, _) => {
@@ -680,7 +677,7 @@ pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty<'v>) {
         }
         TyKind::TraitObject(bounds, ref lifetime, _syntax) => {
             for bound in bounds {
-                visitor.visit_poly_trait_ref(bound, TraitBoundModifier::None);
+                visitor.visit_poly_trait_ref(bound);
             }
             visitor.visit_lifetime(lifetime);
         }
@@ -693,48 +690,35 @@ pub fn walk_inf<'v, V: Visitor<'v>>(visitor: &mut V, inf: &'v InferArg) {
     visitor.visit_id(inf.hir_id);
 }
 
-pub fn walk_qpath<'v, V: Visitor<'v>>(
-    visitor: &mut V,
-    qpath: &'v QPath<'v>,
-    id: HirId,
-    span: Span,
-) {
+pub fn walk_qpath<'v, V: Visitor<'v>>(visitor: &mut V, qpath: &'v QPath<'v>, id: HirId) {
     match *qpath {
         QPath::Resolved(ref maybe_qself, ref path) => {
             walk_list!(visitor, visit_ty, maybe_qself);
             visitor.visit_path(path, id)
         }
         QPath::TypeRelative(ref qself, ref segment) => {
             visitor.visit_ty(qself);
-            visitor.visit_path_segment(span, segment);
+            visitor.visit_path_segment(segment);
         }
         QPath::LangItem(..) => {}
     }
 }
 
 pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>) {
     for segment in path.segments {
-        visitor.visit_path_segment(path.span, segment);
+        visitor.visit_path_segment(segment);
     }
 }
 
-pub fn walk_path_segment<'v, V: Visitor<'v>>(
-    visitor: &mut V,
-    path_span: Span,
-    segment: &'v PathSegment<'v>,
-) {
+pub fn walk_path_segment<'v, V: Visitor<'v>>(visitor: &mut V, segment: &'v PathSegment<'v>) {
     visitor.visit_ident(segment.ident);
     visitor.visit_id(segment.hir_id);
     if let Some(ref args) = segment.args {
-        visitor.visit_generic_args(path_span, args);
+        visitor.visit_generic_args(args);
     }
 }
 
-pub fn walk_generic_args<'v, V: Visitor<'v>>(
-    visitor: &mut V,
-    _path_span: Span,
-    generic_args: &'v GenericArgs<'v>,
-) {
+pub fn walk_generic_args<'v, V: Visitor<'v>>(visitor: &mut V, generic_args: &'v GenericArgs<'v>) {
     walk_list!(visitor, visit_generic_arg, generic_args.args);
     walk_list!(visitor, visit_assoc_type_binding, generic_args.bindings);
 }
@@ -745,7 +729,7 @@ pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(
 ) {
     visitor.visit_id(type_binding.hir_id);
     visitor.visit_ident(type_binding.ident);
-    visitor.visit_generic_args(type_binding.span, type_binding.gen_args);
+    visitor.visit_generic_args(type_binding.gen_args);
     match type_binding.kind {
         TypeBindingKind::Equality { ref term } => match term {
             Term::Ty(ref ty) => visitor.visit_ty(ty),
@@ -819,12 +803,12 @@ pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V, foreign_item: &'v
 
 pub fn walk_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v GenericBound<'v>) {
     match *bound {
-        GenericBound::Trait(ref typ, modifier) => {
-            visitor.visit_poly_trait_ref(typ, modifier);
+        GenericBound::Trait(ref typ, _modifier) => {
+            visitor.visit_poly_trait_ref(typ);
         }
-        GenericBound::LangItemTrait(_, span, hir_id, args) => {
+        GenericBound::LangItemTrait(_, _span, hir_id, args) => {
             visitor.visit_id(hir_id);
-            visitor.visit_generic_args(span, args);
+            visitor.visit_generic_args(args);
         }
         GenericBound::Outlives(ref lifetime) => visitor.visit_lifetime(lifetime),
     }
@@ -910,7 +894,6 @@ pub fn walk_fn<'v, V: Visitor<'v>>(
     function_kind: FnKind<'v>,
     function_declaration: &'v FnDecl<'v>,
     body_id: BodyId,
-    _span: Span,
     id: HirId,
 ) {
     visitor.visit_id(id);
@@ -1095,7 +1078,7 @@ pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>)
             walk_list!(visitor, visit_expr, arguments);
         }
         ExprKind::MethodCall(ref segment, receiver, arguments, _) => {
-            visitor.visit_path_segment(expression.span, segment);
+            visitor.visit_path_segment(segment);
             visitor.visit_expr(receiver);
             walk_list!(visitor, visit_expr, arguments);
         }

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

@@ -91,7 +91,7 @@ impl<'tcx> Visitor<'tcx> for FindNestedTypeVisitor<'tcx> {
             hir::TyKind::TraitObject(bounds, ..) => {
                 for bound in bounds {
                     self.current_index.shift_in(1);
-                    self.visit_poly_trait_ref(bound, hir::TraitBoundModifier::None);
+                    self.visit_poly_trait_ref(bound);
                     self.current_index.shift_out(1);
                 }
             }