Simplify rustc_ast::visit::Visitor::visit_poly_trait_ref.

It is passed an argument that is never used.

compiler/rustc_ast/src/visit.rs

@@ -168,8 +168,8 @@ 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) {
+    fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef) {
-        walk_poly_trait_ref(self, t, m)
+        walk_poly_trait_ref(self, t)
     }
     fn visit_variant_data(&mut self, s: &'ast VariantData) {
         walk_struct_def(self, s)
@@ -281,11 +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>(
+pub fn walk_poly_trait_ref<'a, V>(visitor: &mut V, trait_ref: &'a PolyTraitRef)
-    visitor: &mut V,
+where
-    trait_ref: &'a PolyTraitRef,
-    _: &TraitBoundModifier,
-) where
     V: Visitor<'a>,
 {
     walk_list!(visitor, visit_generic_param, &trait_ref.bound_generic_params);
@@ -587,7 +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/lifetime_collector.rs

@@ -1,9 +1,6 @@
 use super::ResolverAstLoweringExt;
 use rustc_ast::visit::{self, BoundKind, LifetimeCtxt, Visitor};
-use rustc_ast::{
+use rustc_ast::{FnRetTy, GenericBounds, Lifetime, NodeId, PathSegment, PolyTraitRef, Ty, TyKind};
-    FnRetTy, GenericBounds, Lifetime, NodeId, PathSegment, PolyTraitRef, TraitBoundModifier, 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

@@ -1538,9 +1538,9 @@ 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) {

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;

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(
+        fn visit_poly_trait_ref(&mut self, trait_ref: &'a ast::PolyTraitRef) {
-            &mut self,
-            trait_ref: &'a ast::PolyTraitRef,
-            modifier: &'a ast::TraitBoundModifier,
-        ) {
             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_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) {
+    fn visit_poly_trait_ref(&mut self, t: &'a ast::PolyTraitRef) {
-        run_early_pass!(self, check_poly_trait_ref, t, m);
+        run_early_pass!(self, check_poly_trait_ref, t);
-        ast_visit::walk_poly_trait_ref(self, t, m);
+        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/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,
+            fn check_poly_trait_ref(a: &ast::PolyTraitRef);
-                                    b: &ast::TraitBoundModifier);
             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_resolve/src/late.rs

@@ -723,7 +723,7 @@ impl<'a: 'ast, 'ast> Visitor<'ast> for LateResolutionVisitor<'a, '_, 'ast> {
         self.diagnostic_metadata.current_trait_object = prev;
         self.diagnostic_metadata.current_type_path = prev_ty;
     }
-    fn visit_poly_trait_ref(&mut self, tref: &'ast PolyTraitRef, _: &'ast TraitBoundModifier) {
+    fn visit_poly_trait_ref(&mut self, tref: &'ast PolyTraitRef) {
         let span = tref.span.shrink_to_lo().to(tref.trait_ref.path.span.shrink_to_lo());
         self.with_generic_param_rib(
             &tref.bound_generic_params,

src/tools/clippy/clippy_lints/src/unused_unit.rs

@@ -89,7 +89,7 @@ impl EarlyLintPass for UnusedUnit {
         }
     }
 
-    fn check_poly_trait_ref(&mut self, cx: &EarlyContext<'_>, poly: &ast::PolyTraitRef, _: &ast::TraitBoundModifier) {
+    fn check_poly_trait_ref(&mut self, cx: &EarlyContext<'_>, poly: &ast::PolyTraitRef) {
         let segments = &poly.trait_ref.path.segments;
 
         if_chain! {