|  | // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT | 
|  | // file at the top-level directory of this distribution and at | 
|  | // http://rust-lang.org/COPYRIGHT. | 
|  | // | 
|  | // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or | 
|  | // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license | 
|  | // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your | 
|  | // option. This file may not be copied, modified, or distributed | 
|  | // except according to those terms. | 
|  |  | 
|  | //! HIR walker. Each overridden visit method has full control over what | 
|  | //! happens with its node, it can do its own traversal of the node's children, | 
|  | //! call `intravisit::walk_*` to apply the default traversal algorithm, or prevent | 
|  | //! deeper traversal by doing nothing. | 
|  | //! | 
|  | //! When visiting the HIR, the contents of nested items are NOT visited | 
|  | //! by default. This is different from the AST visitor, which does a deep walk. | 
|  | //! Hence this module is called `intravisit`; see the method `visit_nested_item` | 
|  | //! for more details. | 
|  | //! | 
|  | //! Note: it is an important invariant that the default visitor walks | 
|  | //! the body of a function in "execution order" (more concretely, | 
|  | //! reverse post-order with respect to the CFG implied by the AST), | 
|  | //! meaning that if AST node A may execute before AST node B, then A | 
|  | //! is visited first.  The borrow checker in particular relies on this | 
|  | //! property. | 
|  |  | 
|  | use syntax::abi::Abi; | 
|  | use syntax::ast::{NodeId, CRATE_NODE_ID, Name, Attribute}; | 
|  | use syntax::codemap::Span; | 
|  | use hir::*; | 
|  |  | 
|  | #[derive(Copy, Clone, PartialEq, Eq)] | 
|  | pub enum FnKind<'a> { | 
|  | /// fn foo() or extern "Abi" fn foo() | 
|  | ItemFn(Name, &'a Generics, Unsafety, Constness, Abi, Visibility), | 
|  |  | 
|  | /// fn foo(&self) | 
|  | Method(Name, &'a MethodSig, Option<Visibility>), | 
|  |  | 
|  | /// |x, y| {} | 
|  | Closure, | 
|  | } | 
|  |  | 
|  | /// Each method of the Visitor trait is a hook to be potentially | 
|  | /// overridden.  Each method's default implementation recursively visits | 
|  | /// the substructure of the input via the corresponding `walk` method; | 
|  | /// e.g. the `visit_mod` method by default calls `intravisit::walk_mod`. | 
|  | /// | 
|  | /// Note that this visitor does NOT visit nested items by default | 
|  | /// (this is why the module is called `intravisit`, to distinguish it | 
|  | /// from the AST's `visit` module, which acts differently). If you | 
|  | /// simply want to visit all items in the crate in some order, you | 
|  | /// should call `Crate::visit_all_items`. Otherwise, see the comment | 
|  | /// on `visit_nested_item` for details on how to visit nested items. | 
|  | /// | 
|  | /// If you want to ensure that your code handles every variant | 
|  | /// explicitly, you need to override each method.  (And you also need | 
|  | /// to monitor future changes to `Visitor` in case a new method with a | 
|  | /// new default implementation gets introduced.) | 
|  | pub trait Visitor<'v> : Sized { | 
|  | /////////////////////////////////////////////////////////////////////////// | 
|  | // Nested items. | 
|  |  | 
|  | /// Invoked when a nested item is encountered. By default, does | 
|  | /// nothing. If you want a deep walk, you need to override to | 
|  | /// fetch the item contents. But most of the time, it is easier | 
|  | /// (and better) to invoke `Crate::visit_all_items`, which visits | 
|  | /// all items in the crate in some order (but doesn't respect | 
|  | /// nesting). | 
|  | #[allow(unused_variables)] | 
|  | fn visit_nested_item(&mut self, id: ItemId) { | 
|  | } | 
|  |  | 
|  | /// Visit the top-level item and (optionally) nested items. See | 
|  | /// `visit_nested_item` for details. | 
|  | fn visit_item(&mut self, i: &'v Item) { | 
|  | walk_item(self, i) | 
|  | } | 
|  |  | 
|  | /////////////////////////////////////////////////////////////////////////// | 
|  |  | 
|  | fn visit_name(&mut self, _span: Span, _name: Name) { | 
|  | // Nothing to do. | 
|  | } | 
|  | fn visit_ident(&mut self, span: Span, ident: Ident) { | 
|  | walk_ident(self, span, ident); | 
|  | } | 
|  | fn visit_mod(&mut self, m: &'v Mod, _s: Span, _n: NodeId) { | 
|  | walk_mod(self, m) | 
|  | } | 
|  | fn visit_foreign_item(&mut self, i: &'v ForeignItem) { | 
|  | walk_foreign_item(self, i) | 
|  | } | 
|  | fn visit_local(&mut self, l: &'v Local) { | 
|  | walk_local(self, l) | 
|  | } | 
|  | fn visit_block(&mut self, b: &'v Block) { | 
|  | walk_block(self, b) | 
|  | } | 
|  | fn visit_stmt(&mut self, s: &'v Stmt) { | 
|  | walk_stmt(self, s) | 
|  | } | 
|  | fn visit_arm(&mut self, a: &'v Arm) { | 
|  | walk_arm(self, a) | 
|  | } | 
|  | fn visit_pat(&mut self, p: &'v Pat) { | 
|  | walk_pat(self, p) | 
|  | } | 
|  | fn visit_decl(&mut self, d: &'v Decl) { | 
|  | walk_decl(self, d) | 
|  | } | 
|  | fn visit_expr(&mut self, ex: &'v Expr) { | 
|  | walk_expr(self, ex) | 
|  | } | 
|  | fn visit_expr_post(&mut self, _ex: &'v Expr) { | 
|  | } | 
|  | fn visit_ty(&mut self, t: &'v Ty) { | 
|  | walk_ty(self, t) | 
|  | } | 
|  | fn visit_generics(&mut self, g: &'v Generics) { | 
|  | walk_generics(self, g) | 
|  | } | 
|  | fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl, b: &'v Block, s: Span, _: NodeId) { | 
|  | walk_fn(self, fk, fd, b, s) | 
|  | } | 
|  | fn visit_trait_item(&mut self, ti: &'v TraitItem) { | 
|  | walk_trait_item(self, ti) | 
|  | } | 
|  | fn visit_impl_item(&mut self, ii: &'v ImplItem) { | 
|  | walk_impl_item(self, ii) | 
|  | } | 
|  | fn visit_trait_ref(&mut self, t: &'v TraitRef) { | 
|  | walk_trait_ref(self, t) | 
|  | } | 
|  | fn visit_ty_param_bound(&mut self, bounds: &'v TyParamBound) { | 
|  | walk_ty_param_bound(self, bounds) | 
|  | } | 
|  | fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef, m: &'v TraitBoundModifier) { | 
|  | walk_poly_trait_ref(self, t, m) | 
|  | } | 
|  | fn visit_variant_data(&mut self, | 
|  | s: &'v VariantData, | 
|  | _: Name, | 
|  | _: &'v Generics, | 
|  | _: NodeId, | 
|  | _: Span) { | 
|  | walk_struct_def(self, s) | 
|  | } | 
|  | fn visit_struct_field(&mut self, s: &'v StructField) { | 
|  | walk_struct_field(self, s) | 
|  | } | 
|  | fn visit_enum_def(&mut self, | 
|  | enum_definition: &'v EnumDef, | 
|  | generics: &'v Generics, | 
|  | item_id: NodeId, | 
|  | _: Span) { | 
|  | walk_enum_def(self, enum_definition, generics, item_id) | 
|  | } | 
|  | fn visit_variant(&mut self, v: &'v Variant, g: &'v Generics, item_id: NodeId) { | 
|  | walk_variant(self, v, g, item_id) | 
|  | } | 
|  | fn visit_lifetime(&mut self, lifetime: &'v Lifetime) { | 
|  | walk_lifetime(self, lifetime) | 
|  | } | 
|  | fn visit_lifetime_def(&mut self, lifetime: &'v LifetimeDef) { | 
|  | walk_lifetime_def(self, lifetime) | 
|  | } | 
|  | fn visit_explicit_self(&mut self, es: &'v ExplicitSelf) { | 
|  | walk_explicit_self(self, es) | 
|  | } | 
|  | fn visit_path(&mut self, path: &'v Path, _id: NodeId) { | 
|  | walk_path(self, path) | 
|  | } | 
|  | fn visit_path_list_item(&mut self, prefix: &'v Path, item: &'v PathListItem) { | 
|  | walk_path_list_item(self, prefix, item) | 
|  | } | 
|  | fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment) { | 
|  | walk_path_segment(self, path_span, path_segment) | 
|  | } | 
|  | fn visit_path_parameters(&mut self, path_span: Span, path_parameters: &'v PathParameters) { | 
|  | walk_path_parameters(self, path_span, path_parameters) | 
|  | } | 
|  | fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding) { | 
|  | walk_assoc_type_binding(self, type_binding) | 
|  | } | 
|  | fn visit_attribute(&mut self, _attr: &'v Attribute) { | 
|  | } | 
|  | fn visit_macro_def(&mut self, macro_def: &'v MacroDef) { | 
|  | walk_macro_def(self, macro_def) | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_opt_name<'v, V: Visitor<'v>>(visitor: &mut V, span: Span, opt_name: Option<Name>) { | 
|  | for name in opt_name { | 
|  | visitor.visit_name(span, name); | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_opt_ident<'v, V: Visitor<'v>>(visitor: &mut V, span: Span, opt_ident: Option<Ident>) { | 
|  | for ident in opt_ident { | 
|  | visitor.visit_ident(span, ident); | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_ident<'v, V: Visitor<'v>>(visitor: &mut V, span: Span, ident: Ident) { | 
|  | visitor.visit_name(span, ident.name); | 
|  | } | 
|  |  | 
|  | /// Walks the contents of a crate. See also `Crate::visit_all_items`. | 
|  | pub fn walk_crate<'v, V: Visitor<'v>>(visitor: &mut V, krate: &'v Crate) { | 
|  | visitor.visit_mod(&krate.module, krate.span, CRATE_NODE_ID); | 
|  | walk_list!(visitor, visit_attribute, &krate.attrs); | 
|  | walk_list!(visitor, visit_macro_def, &krate.exported_macros); | 
|  | } | 
|  |  | 
|  | pub fn walk_macro_def<'v, V: Visitor<'v>>(visitor: &mut V, macro_def: &'v MacroDef) { | 
|  | visitor.visit_name(macro_def.span, macro_def.name); | 
|  | walk_opt_name(visitor, macro_def.span, macro_def.imported_from); | 
|  | walk_list!(visitor, visit_attribute, ¯o_def.attrs); | 
|  | } | 
|  |  | 
|  | pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod) { | 
|  | for &item_id in &module.item_ids { | 
|  | visitor.visit_nested_item(item_id); | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local) { | 
|  | visitor.visit_pat(&local.pat); | 
|  | walk_list!(visitor, visit_ty, &local.ty); | 
|  | walk_list!(visitor, visit_expr, &local.init); | 
|  | } | 
|  |  | 
|  | pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) { | 
|  | visitor.visit_name(lifetime.span, lifetime.name); | 
|  | } | 
|  |  | 
|  | pub fn walk_lifetime_def<'v, V: Visitor<'v>>(visitor: &mut V, lifetime_def: &'v LifetimeDef) { | 
|  | visitor.visit_lifetime(&lifetime_def.lifetime); | 
|  | walk_list!(visitor, visit_lifetime, &lifetime_def.bounds); | 
|  | } | 
|  |  | 
|  | pub fn walk_explicit_self<'v, V: Visitor<'v>>(visitor: &mut V, explicit_self: &'v ExplicitSelf) { | 
|  | match explicit_self.node { | 
|  | SelfStatic => {} | 
|  | SelfValue(name) => { | 
|  | visitor.visit_name(explicit_self.span, name) | 
|  | } | 
|  | SelfRegion(ref opt_lifetime, _, name) => { | 
|  | visitor.visit_name(explicit_self.span, name); | 
|  | walk_list!(visitor, visit_lifetime, opt_lifetime); | 
|  | } | 
|  | SelfExplicit(ref typ, name) => { | 
|  | visitor.visit_name(explicit_self.span, name); | 
|  | visitor.visit_ty(typ) | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_poly_trait_ref<'v, V>(visitor: &mut V, | 
|  | trait_ref: &'v PolyTraitRef, | 
|  | _modifier: &'v TraitBoundModifier) | 
|  | where V: Visitor<'v> | 
|  | { | 
|  | walk_list!(visitor, visit_lifetime_def, &trait_ref.bound_lifetimes); | 
|  | visitor.visit_trait_ref(&trait_ref.trait_ref); | 
|  | } | 
|  |  | 
|  | pub fn walk_trait_ref<'v, V>(visitor: &mut V, trait_ref: &'v TraitRef) | 
|  | where V: Visitor<'v> | 
|  | { | 
|  | visitor.visit_path(&trait_ref.path, trait_ref.ref_id) | 
|  | } | 
|  |  | 
|  | pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) { | 
|  | visitor.visit_name(item.span, item.name); | 
|  | match item.node { | 
|  | ItemExternCrate(opt_name) => { | 
|  | walk_opt_name(visitor, item.span, opt_name) | 
|  | } | 
|  | ItemUse(ref vp) => { | 
|  | match vp.node { | 
|  | ViewPathSimple(name, ref path) => { | 
|  | visitor.visit_name(vp.span, name); | 
|  | visitor.visit_path(path, item.id); | 
|  | } | 
|  | ViewPathGlob(ref path) => { | 
|  | visitor.visit_path(path, item.id); | 
|  | } | 
|  | ViewPathList(ref prefix, ref list) => { | 
|  | if !list.is_empty() { | 
|  | for item in list { | 
|  | visitor.visit_path_list_item(prefix, item) | 
|  | } | 
|  | } else { | 
|  | visitor.visit_path(prefix, item.id); | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  | ItemStatic(ref typ, _, ref expr) | | 
|  | ItemConst(ref typ, ref expr) => { | 
|  | visitor.visit_ty(typ); | 
|  | visitor.visit_expr(expr); | 
|  | } | 
|  | ItemFn(ref declaration, unsafety, constness, abi, ref generics, ref body) => { | 
|  | visitor.visit_fn(FnKind::ItemFn(item.name, | 
|  | generics, | 
|  | unsafety, | 
|  | constness, | 
|  | abi, | 
|  | item.vis), | 
|  | declaration, | 
|  | body, | 
|  | item.span, | 
|  | item.id) | 
|  | } | 
|  | ItemMod(ref module) => { | 
|  | visitor.visit_mod(module, item.span, item.id) | 
|  | } | 
|  | ItemForeignMod(ref foreign_module) => { | 
|  | walk_list!(visitor, visit_foreign_item, &foreign_module.items); | 
|  | } | 
|  | ItemTy(ref typ, ref type_parameters) => { | 
|  | visitor.visit_ty(typ); | 
|  | visitor.visit_generics(type_parameters) | 
|  | } | 
|  | ItemEnum(ref enum_definition, ref type_parameters) => { | 
|  | visitor.visit_generics(type_parameters); | 
|  | visitor.visit_enum_def(enum_definition, type_parameters, item.id, item.span) | 
|  | } | 
|  | ItemDefaultImpl(_, ref trait_ref) => { | 
|  | visitor.visit_trait_ref(trait_ref) | 
|  | } | 
|  | ItemImpl(_, _, ref type_parameters, ref opt_trait_reference, ref typ, ref impl_items) => { | 
|  | visitor.visit_generics(type_parameters); | 
|  | walk_list!(visitor, visit_trait_ref, opt_trait_reference); | 
|  | visitor.visit_ty(typ); | 
|  | walk_list!(visitor, visit_impl_item, impl_items); | 
|  | } | 
|  | ItemStruct(ref struct_definition, ref generics) => { | 
|  | visitor.visit_generics(generics); | 
|  | visitor.visit_variant_data(struct_definition, item.name, generics, item.id, item.span); | 
|  | } | 
|  | ItemTrait(_, ref generics, ref bounds, ref methods) => { | 
|  | visitor.visit_generics(generics); | 
|  | walk_list!(visitor, visit_ty_param_bound, bounds); | 
|  | walk_list!(visitor, visit_trait_item, methods); | 
|  | } | 
|  | } | 
|  | walk_list!(visitor, visit_attribute, &item.attrs); | 
|  | } | 
|  |  | 
|  | pub fn walk_enum_def<'v, V: Visitor<'v>>(visitor: &mut V, | 
|  | enum_definition: &'v EnumDef, | 
|  | generics: &'v Generics, | 
|  | item_id: NodeId) { | 
|  | walk_list!(visitor, | 
|  | visit_variant, | 
|  | &enum_definition.variants, | 
|  | generics, | 
|  | item_id); | 
|  | } | 
|  |  | 
|  | pub fn walk_variant<'v, V: Visitor<'v>>(visitor: &mut V, | 
|  | variant: &'v Variant, | 
|  | generics: &'v Generics, | 
|  | item_id: NodeId) { | 
|  | visitor.visit_name(variant.span, variant.node.name); | 
|  | visitor.visit_variant_data(&variant.node.data, | 
|  | variant.node.name, | 
|  | generics, | 
|  | item_id, | 
|  | variant.span); | 
|  | walk_list!(visitor, visit_expr, &variant.node.disr_expr); | 
|  | walk_list!(visitor, visit_attribute, &variant.node.attrs); | 
|  | } | 
|  |  | 
|  | pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty) { | 
|  | match typ.node { | 
|  | TyVec(ref ty) => { | 
|  | visitor.visit_ty(ty) | 
|  | } | 
|  | TyPtr(ref mutable_type) => { | 
|  | visitor.visit_ty(&mutable_type.ty) | 
|  | } | 
|  | TyRptr(ref opt_lifetime, ref mutable_type) => { | 
|  | walk_list!(visitor, visit_lifetime, opt_lifetime); | 
|  | visitor.visit_ty(&mutable_type.ty) | 
|  | } | 
|  | TyTup(ref tuple_element_types) => { | 
|  | walk_list!(visitor, visit_ty, tuple_element_types); | 
|  | } | 
|  | TyBareFn(ref function_declaration) => { | 
|  | walk_fn_decl(visitor, &function_declaration.decl); | 
|  | walk_list!(visitor, visit_lifetime_def, &function_declaration.lifetimes); | 
|  | } | 
|  | TyPath(ref maybe_qself, ref path) => { | 
|  | if let Some(ref qself) = *maybe_qself { | 
|  | visitor.visit_ty(&qself.ty); | 
|  | } | 
|  | visitor.visit_path(path, typ.id); | 
|  | } | 
|  | TyObjectSum(ref ty, ref bounds) => { | 
|  | visitor.visit_ty(ty); | 
|  | walk_list!(visitor, visit_ty_param_bound, bounds); | 
|  | } | 
|  | TyFixedLengthVec(ref ty, ref expression) => { | 
|  | visitor.visit_ty(ty); | 
|  | visitor.visit_expr(expression) | 
|  | } | 
|  | TyPolyTraitRef(ref bounds) => { | 
|  | walk_list!(visitor, visit_ty_param_bound, bounds); | 
|  | } | 
|  | TyTypeof(ref expression) => { | 
|  | visitor.visit_expr(expression) | 
|  | } | 
|  | TyInfer => {} | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path) { | 
|  | for segment in &path.segments { | 
|  | visitor.visit_path_segment(path.span, segment); | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_path_list_item<'v, V: Visitor<'v>>(visitor: &mut V, | 
|  | prefix: &'v Path, | 
|  | item: &'v PathListItem) { | 
|  | for segment in &prefix.segments { | 
|  | visitor.visit_path_segment(prefix.span, segment); | 
|  | } | 
|  |  | 
|  | walk_opt_name(visitor, item.span, item.node.name()); | 
|  | walk_opt_name(visitor, item.span, item.node.rename()); | 
|  | } | 
|  |  | 
|  | pub fn walk_path_segment<'v, V: Visitor<'v>>(visitor: &mut V, | 
|  | path_span: Span, | 
|  | segment: &'v PathSegment) { | 
|  | visitor.visit_ident(path_span, segment.identifier); | 
|  | visitor.visit_path_parameters(path_span, &segment.parameters); | 
|  | } | 
|  |  | 
|  | pub fn walk_path_parameters<'v, V: Visitor<'v>>(visitor: &mut V, | 
|  | _path_span: Span, | 
|  | path_parameters: &'v PathParameters) { | 
|  | match *path_parameters { | 
|  | AngleBracketedParameters(ref data) => { | 
|  | walk_list!(visitor, visit_ty, &data.types); | 
|  | walk_list!(visitor, visit_lifetime, &data.lifetimes); | 
|  | walk_list!(visitor, visit_assoc_type_binding, &data.bindings); | 
|  | } | 
|  | ParenthesizedParameters(ref data) => { | 
|  | walk_list!(visitor, visit_ty, &data.inputs); | 
|  | walk_list!(visitor, visit_ty, &data.output); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(visitor: &mut V, | 
|  | type_binding: &'v TypeBinding) { | 
|  | visitor.visit_name(type_binding.span, type_binding.name); | 
|  | visitor.visit_ty(&type_binding.ty); | 
|  | } | 
|  |  | 
|  | pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat) { | 
|  | match pattern.node { | 
|  | PatEnum(ref path, ref opt_children) => { | 
|  | visitor.visit_path(path, pattern.id); | 
|  | if let Some(ref children) = *opt_children { | 
|  | walk_list!(visitor, visit_pat, children); | 
|  | } | 
|  | } | 
|  | PatQPath(ref qself, ref path) => { | 
|  | visitor.visit_ty(&qself.ty); | 
|  | visitor.visit_path(path, pattern.id) | 
|  | } | 
|  | PatStruct(ref path, ref fields, _) => { | 
|  | visitor.visit_path(path, pattern.id); | 
|  | for field in fields { | 
|  | visitor.visit_name(field.span, field.node.name); | 
|  | visitor.visit_pat(&field.node.pat) | 
|  | } | 
|  | } | 
|  | PatTup(ref tuple_elements) => { | 
|  | walk_list!(visitor, visit_pat, tuple_elements); | 
|  | } | 
|  | PatBox(ref subpattern) | | 
|  | PatRegion(ref subpattern, _) => { | 
|  | visitor.visit_pat(subpattern) | 
|  | } | 
|  | PatIdent(_, ref pth1, ref optional_subpattern) => { | 
|  | visitor.visit_ident(pth1.span, pth1.node); | 
|  | walk_list!(visitor, visit_pat, optional_subpattern); | 
|  | } | 
|  | PatLit(ref expression) => visitor.visit_expr(expression), | 
|  | PatRange(ref lower_bound, ref upper_bound) => { | 
|  | visitor.visit_expr(lower_bound); | 
|  | visitor.visit_expr(upper_bound) | 
|  | } | 
|  | PatWild => (), | 
|  | PatVec(ref prepatterns, ref slice_pattern, ref postpatterns) => { | 
|  | walk_list!(visitor, visit_pat, prepatterns); | 
|  | walk_list!(visitor, visit_pat, slice_pattern); | 
|  | walk_list!(visitor, visit_pat, postpatterns); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V, foreign_item: &'v ForeignItem) { | 
|  | visitor.visit_name(foreign_item.span, foreign_item.name); | 
|  |  | 
|  | match foreign_item.node { | 
|  | ForeignItemFn(ref function_declaration, ref generics) => { | 
|  | walk_fn_decl(visitor, function_declaration); | 
|  | visitor.visit_generics(generics) | 
|  | } | 
|  | ForeignItemStatic(ref typ, _) => visitor.visit_ty(typ), | 
|  | } | 
|  |  | 
|  | walk_list!(visitor, visit_attribute, &foreign_item.attrs); | 
|  | } | 
|  |  | 
|  | pub fn walk_ty_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v TyParamBound) { | 
|  | match *bound { | 
|  | TraitTyParamBound(ref typ, ref modifier) => { | 
|  | visitor.visit_poly_trait_ref(typ, modifier); | 
|  | } | 
|  | RegionTyParamBound(ref lifetime) => { | 
|  | visitor.visit_lifetime(lifetime); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics) { | 
|  | for param in &generics.ty_params { | 
|  | visitor.visit_name(param.span, param.name); | 
|  | walk_list!(visitor, visit_ty_param_bound, ¶m.bounds); | 
|  | walk_list!(visitor, visit_ty, ¶m.default); | 
|  | } | 
|  | walk_list!(visitor, visit_lifetime_def, &generics.lifetimes); | 
|  | for predicate in &generics.where_clause.predicates { | 
|  | match predicate { | 
|  | &WherePredicate::BoundPredicate(WhereBoundPredicate{ref bounded_ty, | 
|  | ref bounds, | 
|  | ref bound_lifetimes, | 
|  | ..}) => { | 
|  | visitor.visit_ty(bounded_ty); | 
|  | walk_list!(visitor, visit_ty_param_bound, bounds); | 
|  | walk_list!(visitor, visit_lifetime_def, bound_lifetimes); | 
|  | } | 
|  | &WherePredicate::RegionPredicate(WhereRegionPredicate{ref lifetime, | 
|  | ref bounds, | 
|  | ..}) => { | 
|  | visitor.visit_lifetime(lifetime); | 
|  | walk_list!(visitor, visit_lifetime, bounds); | 
|  | } | 
|  | &WherePredicate::EqPredicate(WhereEqPredicate{id, | 
|  | ref path, | 
|  | ref ty, | 
|  | ..}) => { | 
|  | visitor.visit_path(path, id); | 
|  | visitor.visit_ty(ty); | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FunctionRetTy) { | 
|  | if let Return(ref output_ty) = *ret_ty { | 
|  | visitor.visit_ty(output_ty) | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl) { | 
|  | for argument in &function_declaration.inputs { | 
|  | visitor.visit_pat(&argument.pat); | 
|  | visitor.visit_ty(&argument.ty) | 
|  | } | 
|  | walk_fn_ret_ty(visitor, &function_declaration.output) | 
|  | } | 
|  |  | 
|  | pub fn walk_fn_decl_nopat<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl) { | 
|  | for argument in &function_declaration.inputs { | 
|  | visitor.visit_ty(&argument.ty) | 
|  | } | 
|  | walk_fn_ret_ty(visitor, &function_declaration.output) | 
|  | } | 
|  |  | 
|  | pub fn walk_fn_kind<'v, V: Visitor<'v>>(visitor: &mut V, function_kind: FnKind<'v>) { | 
|  | match function_kind { | 
|  | FnKind::ItemFn(_, generics, _, _, _, _) => { | 
|  | visitor.visit_generics(generics); | 
|  | } | 
|  | FnKind::Method(_, sig, _) => { | 
|  | visitor.visit_generics(&sig.generics); | 
|  | visitor.visit_explicit_self(&sig.explicit_self); | 
|  | } | 
|  | FnKind::Closure => {} | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_fn<'v, V: Visitor<'v>>(visitor: &mut V, | 
|  | function_kind: FnKind<'v>, | 
|  | function_declaration: &'v FnDecl, | 
|  | function_body: &'v Block, | 
|  | _span: Span) { | 
|  | walk_fn_decl(visitor, function_declaration); | 
|  | walk_fn_kind(visitor, function_kind); | 
|  | visitor.visit_block(function_body) | 
|  | } | 
|  |  | 
|  | pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem) { | 
|  | visitor.visit_name(trait_item.span, trait_item.name); | 
|  | walk_list!(visitor, visit_attribute, &trait_item.attrs); | 
|  | match trait_item.node { | 
|  | ConstTraitItem(ref ty, ref default) => { | 
|  | visitor.visit_ty(ty); | 
|  | walk_list!(visitor, visit_expr, default); | 
|  | } | 
|  | MethodTraitItem(ref sig, None) => { | 
|  | visitor.visit_explicit_self(&sig.explicit_self); | 
|  | visitor.visit_generics(&sig.generics); | 
|  | walk_fn_decl(visitor, &sig.decl); | 
|  | } | 
|  | MethodTraitItem(ref sig, Some(ref body)) => { | 
|  | visitor.visit_fn(FnKind::Method(trait_item.name, sig, None), | 
|  | &sig.decl, | 
|  | body, | 
|  | trait_item.span, | 
|  | trait_item.id); | 
|  | } | 
|  | TypeTraitItem(ref bounds, ref default) => { | 
|  | walk_list!(visitor, visit_ty_param_bound, bounds); | 
|  | walk_list!(visitor, visit_ty, default); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem) { | 
|  | visitor.visit_name(impl_item.span, impl_item.name); | 
|  | walk_list!(visitor, visit_attribute, &impl_item.attrs); | 
|  | match impl_item.node { | 
|  | ImplItemKind::Const(ref ty, ref expr) => { | 
|  | visitor.visit_ty(ty); | 
|  | visitor.visit_expr(expr); | 
|  | } | 
|  | ImplItemKind::Method(ref sig, ref body) => { | 
|  | visitor.visit_fn(FnKind::Method(impl_item.name, sig, Some(impl_item.vis)), | 
|  | &sig.decl, | 
|  | body, | 
|  | impl_item.span, | 
|  | impl_item.id); | 
|  | } | 
|  | ImplItemKind::Type(ref ty) => { | 
|  | visitor.visit_ty(ty); | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_struct_def<'v, V: Visitor<'v>>(visitor: &mut V, struct_definition: &'v VariantData) { | 
|  | walk_list!(visitor, visit_struct_field, struct_definition.fields()); | 
|  | } | 
|  |  | 
|  | pub fn walk_struct_field<'v, V: Visitor<'v>>(visitor: &mut V, struct_field: &'v StructField) { | 
|  | walk_opt_name(visitor, struct_field.span, struct_field.node.name()); | 
|  | visitor.visit_ty(&struct_field.node.ty); | 
|  | walk_list!(visitor, visit_attribute, &struct_field.node.attrs); | 
|  | } | 
|  |  | 
|  | pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block) { | 
|  | walk_list!(visitor, visit_stmt, &block.stmts); | 
|  | walk_list!(visitor, visit_expr, &block.expr); | 
|  | } | 
|  |  | 
|  | pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt) { | 
|  | match statement.node { | 
|  | StmtDecl(ref declaration, _) => visitor.visit_decl(declaration), | 
|  | StmtExpr(ref expression, _) | StmtSemi(ref expression, _) => { | 
|  | visitor.visit_expr(expression) | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_decl<'v, V: Visitor<'v>>(visitor: &mut V, declaration: &'v Decl) { | 
|  | match declaration.node { | 
|  | DeclLocal(ref local) => visitor.visit_local(local), | 
|  | DeclItem(item) => visitor.visit_nested_item(item), | 
|  | } | 
|  | } | 
|  |  | 
|  | pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) { | 
|  | match expression.node { | 
|  | ExprBox(ref subexpression) => { | 
|  | visitor.visit_expr(subexpression) | 
|  | } | 
|  | ExprVec(ref subexpressions) => { | 
|  | walk_list!(visitor, visit_expr, subexpressions); | 
|  | } | 
|  | ExprRepeat(ref element, ref count) => { | 
|  | visitor.visit_expr(element); | 
|  | visitor.visit_expr(count) | 
|  | } | 
|  | ExprStruct(ref path, ref fields, ref optional_base) => { | 
|  | visitor.visit_path(path, expression.id); | 
|  | for field in fields { | 
|  | visitor.visit_name(field.name.span, field.name.node); | 
|  | visitor.visit_expr(&field.expr) | 
|  | } | 
|  | walk_list!(visitor, visit_expr, optional_base); | 
|  | } | 
|  | ExprTup(ref subexpressions) => { | 
|  | walk_list!(visitor, visit_expr, subexpressions); | 
|  | } | 
|  | ExprCall(ref callee_expression, ref arguments) => { | 
|  | walk_list!(visitor, visit_expr, arguments); | 
|  | visitor.visit_expr(callee_expression) | 
|  | } | 
|  | ExprMethodCall(ref name, ref types, ref arguments) => { | 
|  | visitor.visit_name(name.span, name.node); | 
|  | walk_list!(visitor, visit_expr, arguments); | 
|  | walk_list!(visitor, visit_ty, types); | 
|  | } | 
|  | ExprBinary(_, ref left_expression, ref right_expression) => { | 
|  | visitor.visit_expr(left_expression); | 
|  | visitor.visit_expr(right_expression) | 
|  | } | 
|  | ExprAddrOf(_, ref subexpression) | ExprUnary(_, ref subexpression) => { | 
|  | visitor.visit_expr(subexpression) | 
|  | } | 
|  | ExprLit(_) => {} | 
|  | ExprCast(ref subexpression, ref typ) | ExprType(ref subexpression, ref typ) => { | 
|  | visitor.visit_expr(subexpression); | 
|  | visitor.visit_ty(typ) | 
|  | } | 
|  | ExprIf(ref head_expression, ref if_block, ref optional_else) => { | 
|  | visitor.visit_expr(head_expression); | 
|  | visitor.visit_block(if_block); | 
|  | walk_list!(visitor, visit_expr, optional_else); | 
|  | } | 
|  | ExprWhile(ref subexpression, ref block, opt_ident) => { | 
|  | visitor.visit_expr(subexpression); | 
|  | visitor.visit_block(block); | 
|  | walk_opt_ident(visitor, expression.span, opt_ident) | 
|  | } | 
|  | ExprLoop(ref block, opt_ident) => { | 
|  | visitor.visit_block(block); | 
|  | walk_opt_ident(visitor, expression.span, opt_ident) | 
|  | } | 
|  | ExprMatch(ref subexpression, ref arms, _) => { | 
|  | visitor.visit_expr(subexpression); | 
|  | walk_list!(visitor, visit_arm, arms); | 
|  | } | 
|  | ExprClosure(_, ref function_declaration, ref body) => { | 
|  | visitor.visit_fn(FnKind::Closure, | 
|  | function_declaration, | 
|  | body, | 
|  | expression.span, | 
|  | expression.id) | 
|  | } | 
|  | ExprBlock(ref block) => visitor.visit_block(block), | 
|  | ExprAssign(ref left_hand_expression, ref right_hand_expression) => { | 
|  | visitor.visit_expr(right_hand_expression); | 
|  | visitor.visit_expr(left_hand_expression) | 
|  | } | 
|  | ExprAssignOp(_, ref left_expression, ref right_expression) => { | 
|  | visitor.visit_expr(right_expression); | 
|  | visitor.visit_expr(left_expression) | 
|  | } | 
|  | ExprField(ref subexpression, ref name) => { | 
|  | visitor.visit_expr(subexpression); | 
|  | visitor.visit_name(name.span, name.node); | 
|  | } | 
|  | ExprTupField(ref subexpression, _) => { | 
|  | visitor.visit_expr(subexpression); | 
|  | } | 
|  | ExprIndex(ref main_expression, ref index_expression) => { | 
|  | visitor.visit_expr(main_expression); | 
|  | visitor.visit_expr(index_expression) | 
|  | } | 
|  | ExprRange(ref start, ref end) => { | 
|  | walk_list!(visitor, visit_expr, start); | 
|  | walk_list!(visitor, visit_expr, end); | 
|  | } | 
|  | ExprPath(ref maybe_qself, ref path) => { | 
|  | if let Some(ref qself) = *maybe_qself { | 
|  | visitor.visit_ty(&qself.ty); | 
|  | } | 
|  | visitor.visit_path(path, expression.id) | 
|  | } | 
|  | ExprBreak(ref opt_sp_ident) | ExprAgain(ref opt_sp_ident) => { | 
|  | for sp_ident in opt_sp_ident { | 
|  | visitor.visit_ident(sp_ident.span, sp_ident.node); | 
|  | } | 
|  | } | 
|  | ExprRet(ref optional_expression) => { | 
|  | walk_list!(visitor, visit_expr, optional_expression); | 
|  | } | 
|  | ExprInlineAsm(ref ia) => { | 
|  | for &(_, ref input) in &ia.inputs { | 
|  | visitor.visit_expr(&input) | 
|  | } | 
|  | for output in &ia.outputs { | 
|  | visitor.visit_expr(&output.expr) | 
|  | } | 
|  | } | 
|  | } | 
|  |  | 
|  | visitor.visit_expr_post(expression) | 
|  | } | 
|  |  | 
|  | pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm) { | 
|  | walk_list!(visitor, visit_pat, &arm.pats); | 
|  | walk_list!(visitor, visit_expr, &arm.guard); | 
|  | visitor.visit_expr(&arm.body); | 
|  | walk_list!(visitor, visit_attribute, &arm.attrs); | 
|  | } |