Rollup merge of #100392 - nnethercote:simplify-visitors, r=cjgillot

Simplify visitors

By removing some unused arguments.

r? `@cjgillot`

compiler/rustc_ast/src/visit.rs

@@ -168,23 +168,17 @@ pub trait Visitor<'ast>: Sized {
     fn visit_param_bound(&mut self, bounds: &'ast GenericBound, _ctxt: BoundKind) {
         walk_param_bound(self, bounds)
     }
-    fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef, m: &'ast TraitBoundModifier) {
-        walk_poly_trait_ref(self, t, m)
+    fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef) {
+        walk_poly_trait_ref(self, t)
     }
     fn visit_variant_data(&mut self, s: &'ast VariantData) {
         walk_struct_def(self, s)
     }
     fn visit_field_def(&mut self, s: &'ast FieldDef) {
         walk_field_def(self, s)
     }
-    fn visit_enum_def(
-        &mut self,
-        enum_definition: &'ast EnumDef,
-        generics: &'ast Generics,
-        item_id: NodeId,
-        _: Span,
-    ) {
-        walk_enum_def(self, enum_definition, generics, item_id)
+    fn visit_enum_def(&mut self, enum_definition: &'ast EnumDef) {
+        walk_enum_def(self, enum_definition)
     }
     fn visit_variant(&mut self, v: &'ast Variant) {
         walk_variant(self, v)
@@ -287,11 +281,8 @@ pub fn walk_lifetime<'a, V: Visitor<'a>>(visitor: &mut V, lifetime: &'a Lifetime
     visitor.visit_ident(lifetime.ident);
 }
 
-pub fn walk_poly_trait_ref<'a, V>(
-    visitor: &mut V,
-    trait_ref: &'a PolyTraitRef,
-    _: &TraitBoundModifier,
-) where
+pub fn walk_poly_trait_ref<'a, V>(visitor: &mut V, trait_ref: &'a PolyTraitRef)
+where
     V: Visitor<'a>,
 {
     walk_list!(visitor, visit_generic_param, &trait_ref.bound_generic_params);
@@ -334,7 +325,7 @@ pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
         }
         ItemKind::Enum(ref enum_definition, ref generics) => {
             visitor.visit_generics(generics);
-            visitor.visit_enum_def(enum_definition, generics, item.id, item.span)
+            visitor.visit_enum_def(enum_definition)
         }
         ItemKind::Impl(box Impl {
             defaultness: _,
@@ -377,12 +368,7 @@ pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
     walk_list!(visitor, visit_attribute, &item.attrs);
 }
 
-pub fn walk_enum_def<'a, V: Visitor<'a>>(
-    visitor: &mut V,
-    enum_definition: &'a EnumDef,
-    _: &'a Generics,
-    _: NodeId,
-) {
+pub fn walk_enum_def<'a, V: Visitor<'a>>(visitor: &mut V, enum_definition: &'a EnumDef) {
     walk_list!(visitor, visit_variant, &enum_definition.variants);
 }
 
@@ -598,7 +584,7 @@ pub fn walk_foreign_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a ForeignI
 
 pub fn walk_param_bound<'a, V: Visitor<'a>>(visitor: &mut V, bound: &'a GenericBound) {
     match *bound {
-        GenericBound::Trait(ref typ, ref modifier) => visitor.visit_poly_trait_ref(typ, modifier),
+        GenericBound::Trait(ref typ, ref _modifier) => visitor.visit_poly_trait_ref(typ),
         GenericBound::Outlives(ref lifetime) => {
             visitor.visit_lifetime(lifetime, LifetimeCtxt::Bound)
         }

compiler/rustc_ast_lowering/src/index.rs

@@ -295,14 +295,14 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         self.insert(lifetime.span, lifetime.hir_id, Node::Lifetime(lifetime));
     }
 
-    fn visit_variant(&mut self, v: &'hir Variant<'hir>, g: &'hir Generics<'hir>, item_id: HirId) {
+    fn visit_variant(&mut self, v: &'hir Variant<'hir>) {
         self.insert(v.span, v.id, Node::Variant(v));
         self.with_parent(v.id, |this| {
             // Register the constructor of this variant.
             if let Some(ctor_hir_id) = v.data.ctor_hir_id() {
                 this.insert(v.span, ctor_hir_id, Node::Ctor(&v.data));
             }
-            intravisit::walk_variant(this, v, g, item_id);
+            intravisit::walk_variant(this, v);
         });
     }
 

compiler/rustc_ast_lowering/src/lifetime_collector.rs

@@ -1,9 +1,6 @@
 use super::ResolverAstLoweringExt;
 use rustc_ast::visit::{self, BoundKind, LifetimeCtxt, Visitor};
-use rustc_ast::{
-    FnRetTy, GenericBounds, Lifetime, NodeId, PathSegment, PolyTraitRef, TraitBoundModifier, Ty,
-    TyKind,
-};
+use rustc_ast::{FnRetTy, GenericBounds, Lifetime, NodeId, PathSegment, PolyTraitRef, Ty, TyKind};
 use rustc_hir::def::LifetimeRes;
 use rustc_middle::span_bug;
 use rustc_middle::ty::ResolverAstLowering;
@@ -71,10 +68,10 @@ impl<'ast> Visitor<'ast> for LifetimeCollectVisitor<'ast> {
         visit::walk_path_segment(self, path_span, path_segment);
     }
 
-    fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef, m: &'ast TraitBoundModifier) {
+    fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef) {
         self.current_binders.push(t.trait_ref.ref_id);
 
-        visit::walk_poly_trait_ref(self, t, m);
+        visit::walk_poly_trait_ref(self, t);
 
         self.current_binders.pop();
     }

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -1536,25 +1536,17 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
         visit::walk_param_bound(self, bound)
     }
 
-    fn visit_poly_trait_ref(&mut self, t: &'a PolyTraitRef, m: &'a TraitBoundModifier) {
+    fn visit_poly_trait_ref(&mut self, t: &'a PolyTraitRef) {
         self.check_late_bound_lifetime_defs(&t.bound_generic_params);
-        visit::walk_poly_trait_ref(self, t, m);
+        visit::walk_poly_trait_ref(self, t);
     }
 
     fn visit_variant_data(&mut self, s: &'a VariantData) {
         self.with_banned_assoc_ty_bound(|this| visit::walk_struct_def(this, s))
     }
 
-    fn visit_enum_def(
-        &mut self,
-        enum_definition: &'a EnumDef,
-        generics: &'a Generics,
-        item_id: NodeId,
-        _: Span,
-    ) {
-        self.with_banned_assoc_ty_bound(|this| {
-            visit::walk_enum_def(this, enum_definition, generics, item_id)
-        })
+    fn visit_enum_def(&mut self, enum_definition: &'a EnumDef) {
+        self.with_banned_assoc_ty_bound(|this| visit::walk_enum_def(this, enum_definition))
     }
 
     fn visit_fn(&mut self, fk: FnKind<'a>, span: Span, id: NodeId) {

compiler/rustc_ast_passes/src/node_count.rs

@@ -79,9 +79,9 @@ impl<'ast> Visitor<'ast> for NodeCounter {
         self.count += 1;
         walk_param_bound(self, bounds)
     }
-    fn visit_poly_trait_ref(&mut self, t: &PolyTraitRef, m: &TraitBoundModifier) {
+    fn visit_poly_trait_ref(&mut self, t: &PolyTraitRef) {
         self.count += 1;
-        walk_poly_trait_ref(self, t, m)
+        walk_poly_trait_ref(self, t)
     }
     fn visit_variant_data(&mut self, s: &VariantData) {
         self.count += 1;
@@ -91,15 +91,9 @@ impl<'ast> Visitor<'ast> for NodeCounter {
         self.count += 1;
         walk_field_def(self, s)
     }
-    fn visit_enum_def(
-        &mut self,
-        enum_definition: &EnumDef,
-        generics: &Generics,
-        item_id: NodeId,
-        _: Span,
-    ) {
+    fn visit_enum_def(&mut self, enum_definition: &EnumDef) {
         self.count += 1;
-        walk_enum_def(self, enum_definition, generics, item_id)
+        walk_enum_def(self, enum_definition)
     }
     fn visit_variant(&mut self, v: &Variant) {
         self.count += 1;

compiler/rustc_builtin_macros/src/deriving/generic/mod.rs

@@ -383,16 +383,12 @@ fn find_type_parameters(
         }
 
         // Place bound generic params on a stack, to extract them when a type is encountered.
-        fn visit_poly_trait_ref(
-            &mut self,
-            trait_ref: &'a ast::PolyTraitRef,
-            modifier: &'a ast::TraitBoundModifier,
-        ) {
+        fn visit_poly_trait_ref(&mut self, trait_ref: &'a ast::PolyTraitRef) {
             let stack_len = self.bound_generic_params_stack.len();
             self.bound_generic_params_stack
                 .extend(trait_ref.bound_generic_params.clone().into_iter());
 
-            visit::walk_poly_trait_ref(self, trait_ref, modifier);
+            visit::walk_poly_trait_ref(self, trait_ref);
 
             self.bound_generic_params_stack.truncate(stack_len);
         }

compiler/rustc_hir/src/intravisit.rs

@@ -385,30 +385,17 @@ pub trait Visitor<'v>: Sized {
     fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef<'v>, m: TraitBoundModifier) {
         walk_poly_trait_ref(self, t, m)
     }
-    fn visit_variant_data(
-        &mut self,
-        s: &'v VariantData<'v>,
-        _: Symbol,
-        _: &'v Generics<'v>,
-        _parent_id: HirId,
-        _: Span,
-    ) {
+    fn visit_variant_data(&mut self, s: &'v VariantData<'v>) {
         walk_struct_def(self, s)
     }
     fn visit_field_def(&mut self, s: &'v FieldDef<'v>) {
         walk_field_def(self, s)
     }
-    fn visit_enum_def(
-        &mut self,
-        enum_definition: &'v EnumDef<'v>,
-        generics: &'v Generics<'v>,
-        item_id: HirId,
-        _: Span,
-    ) {
-        walk_enum_def(self, enum_definition, generics, item_id)
+    fn visit_enum_def(&mut self, enum_definition: &'v EnumDef<'v>, item_id: HirId) {
+        walk_enum_def(self, enum_definition, item_id)
     }
-    fn visit_variant(&mut self, v: &'v Variant<'v>, g: &'v Generics<'v>, item_id: HirId) {
-        walk_variant(self, v, g, item_id)
+    fn visit_variant(&mut self, v: &'v Variant<'v>) {
+        walk_variant(self, v)
     }
     fn visit_label(&mut self, label: &'v Label) {
         walk_label(self, label)
@@ -572,7 +559,7 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) {
         ItemKind::Enum(ref enum_definition, ref generics) => {
             visitor.visit_generics(generics);
             // `visit_enum_def()` takes care of visiting the `Item`'s `HirId`.
-            visitor.visit_enum_def(enum_definition, generics, item.hir_id(), item.span)
+            visitor.visit_enum_def(enum_definition, item.hir_id())
         }
         ItemKind::Impl(Impl {
             unsafety: _,
@@ -595,13 +582,7 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) {
         | ItemKind::Union(ref struct_definition, ref generics) => {
             visitor.visit_generics(generics);
             visitor.visit_id(item.hir_id());
-            visitor.visit_variant_data(
-                struct_definition,
-                item.ident.name,
-                generics,
-                item.hir_id(),
-                item.span,
-            );
+            visitor.visit_variant_data(struct_definition);
         }
         ItemKind::Trait(.., ref generics, bounds, trait_item_refs) => {
             visitor.visit_id(item.hir_id());
@@ -649,28 +630,16 @@ pub fn walk_use<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>, hir_id:
 pub fn walk_enum_def<'v, V: Visitor<'v>>(
     visitor: &mut V,
     enum_definition: &'v EnumDef<'v>,
-    generics: &'v Generics<'v>,
     item_id: HirId,
 ) {
     visitor.visit_id(item_id);
-    walk_list!(visitor, visit_variant, enum_definition.variants, generics, item_id);
+    walk_list!(visitor, visit_variant, enum_definition.variants);
 }
 
-pub fn walk_variant<'v, V: Visitor<'v>>(
-    visitor: &mut V,
-    variant: &'v Variant<'v>,
-    generics: &'v Generics<'v>,
-    parent_item_id: HirId,
-) {
+pub fn walk_variant<'v, V: Visitor<'v>>(visitor: &mut V, variant: &'v Variant<'v>) {
     visitor.visit_ident(variant.ident);
     visitor.visit_id(variant.id);
-    visitor.visit_variant_data(
-        &variant.data,
-        variant.ident.name,
-        generics,
-        parent_item_id,
-        variant.span,
-    );
+    visitor.visit_variant_data(&variant.data);
     walk_list!(visitor, visit_anon_const, &variant.disr_expr);
 }
 

compiler/rustc_lint/src/early.rs

@@ -233,9 +233,9 @@ impl<'a, T: EarlyLintPass> ast_visit::Visitor<'a> for EarlyContextAndPass<'a, T>
         ast_visit::walk_where_predicate(self, p);
     }
 
-    fn visit_poly_trait_ref(&mut self, t: &'a ast::PolyTraitRef, m: &'a ast::TraitBoundModifier) {
-        run_early_pass!(self, check_poly_trait_ref, t, m);
-        ast_visit::walk_poly_trait_ref(self, t, m);
+    fn visit_poly_trait_ref(&mut self, t: &'a ast::PolyTraitRef) {
+        run_early_pass!(self, check_poly_trait_ref, t);
+        ast_visit::walk_poly_trait_ref(self, t);
     }
 
     fn visit_assoc_item(&mut self, item: &'a ast::AssocItem, ctxt: ast_visit::AssocCtxt) {

compiler/rustc_lint/src/late.rs

@@ -24,7 +24,6 @@ use rustc_hir::intravisit::Visitor;
 use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_session::lint::LintPass;
-use rustc_span::symbol::Symbol;
 use rustc_span::Span;
 
 use std::any::Any;
@@ -194,14 +193,7 @@ impl<'tcx, T: LateLintPass<'tcx>> hir_visit::Visitor<'tcx> for LateContextAndPas
         self.context.cached_typeck_results.set(old_cached_typeck_results);
     }
 
-    fn visit_variant_data(
-        &mut self,
-        s: &'tcx hir::VariantData<'tcx>,
-        _: Symbol,
-        _: &'tcx hir::Generics<'tcx>,
-        _: hir::HirId,
-        _: Span,
-    ) {
+    fn visit_variant_data(&mut self, s: &'tcx hir::VariantData<'tcx>) {
         lint_callback!(self, check_struct_def, s);
         hir_visit::walk_struct_def(self, s);
     }
@@ -213,15 +205,10 @@ impl<'tcx, T: LateLintPass<'tcx>> hir_visit::Visitor<'tcx> for LateContextAndPas
         })
     }
 
-    fn visit_variant(
-        &mut self,
-        v: &'tcx hir::Variant<'tcx>,
-        g: &'tcx hir::Generics<'tcx>,
-        item_id: hir::HirId,
-    ) {
+    fn visit_variant(&mut self, v: &'tcx hir::Variant<'tcx>) {
         self.with_lint_attrs(v.id, |cx| {
             lint_callback!(cx, check_variant, v);
-            hir_visit::walk_variant(cx, v, g, item_id);
+            hir_visit::walk_variant(cx, v);
         })
     }
 

compiler/rustc_lint/src/levels.rs

@@ -772,14 +772,9 @@ impl<'tcx> intravisit::Visitor<'tcx> for LintLevelMapBuilder<'tcx> {
         })
     }
 
-    fn visit_variant(
-        &mut self,
-        v: &'tcx hir::Variant<'tcx>,
-        g: &'tcx hir::Generics<'tcx>,
-        item_id: hir::HirId,
-    ) {
+    fn visit_variant(&mut self, v: &'tcx hir::Variant<'tcx>) {
         self.with_lint_attrs(v.id, |builder| {
-            intravisit::walk_variant(builder, v, g, item_id);
+            intravisit::walk_variant(builder, v);
         })
     }
 

compiler/rustc_lint/src/passes.rs

@@ -156,8 +156,7 @@ macro_rules! early_lint_methods {
             fn check_generic_arg(a: &ast::GenericArg);
             fn check_generic_param(a: &ast::GenericParam);
             fn check_generics(a: &ast::Generics);
-            fn check_poly_trait_ref(a: &ast::PolyTraitRef,
-                                    b: &ast::TraitBoundModifier);
+            fn check_poly_trait_ref(a: &ast::PolyTraitRef);
             fn check_fn(a: rustc_ast::visit::FnKind<'_>, c: Span, d_: ast::NodeId);
             fn check_trait_item(a: &ast::AssocItem);
             fn check_impl_item(a: &ast::AssocItem);

compiler/rustc_mir_transform/src/lib.rs

@@ -29,7 +29,6 @@ use rustc_middle::mir::visit::Visitor as _;
 use rustc_middle::mir::{traversal, Body, ConstQualifs, MirPass, MirPhase, Promoted};
 use rustc_middle::ty::query::Providers;
 use rustc_middle::ty::{self, TyCtxt, TypeVisitable};
-use rustc_span::{Span, Symbol};
 
 #[macro_use]
 mod pass_manager;
@@ -159,14 +158,7 @@ fn mir_keys(tcx: TyCtxt<'_>, (): ()) -> FxIndexSet<LocalDefId> {
         set: &'a mut FxIndexSet<LocalDefId>,
     }
     impl<'tcx> Visitor<'tcx> for GatherCtors<'_, 'tcx> {
-        fn visit_variant_data(
-            &mut self,
-            v: &'tcx hir::VariantData<'tcx>,
-            _: Symbol,
-            _: &'tcx hir::Generics<'tcx>,
-            _: hir::HirId,
-            _: Span,
-        ) {
+        fn visit_variant_data(&mut self, v: &'tcx hir::VariantData<'tcx>) {
             if let hir::VariantData::Tuple(_, hir_id) = *v {
                 self.set.insert(self.tcx.hir().local_def_id(hir_id));
             }