// 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 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. //! HIR walker for walking the contents of nodes. //! //! **For an overview of the visitor strategy, see the docs on the //! `super::itemlikevisit::ItemLikeVisitor` trait.** //! //! If you have decided to use this visitor, here are some general //! notes on how to do it: //! //! 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, if //! we consider the reverse post-order (RPO) of the CFG implied by the HIR, //! then a pre-order traversal of the HIR is consistent with the CFG RPO //! on the *initial CFG point* of each HIR node, while a post-order traversal //! of the HIR is consistent with the CFG RPO on each *final CFG point* of //! each CFG node. //! //! One thing that follows is that if HIR node A always starts/ends executing //! before HIR node B, then A appears in traversal pre/postorder before B, //! respectively. (This follows from RPO respecting CFG domination). //! //! This order consistency is required in a few places in rustc, for //! example generator inference, and possibly also HIR borrowck. use rustc_target::spec::abi::Abi; use syntax::ast::{NodeId, CRATE_NODE_ID, Ident, Name, Attribute}; use syntax_pos::Span; use hir::*; use hir::def::Def; use hir::map::{self, Map}; use super::itemlikevisit::DeepVisitor; use std::cmp; use std::u32; #[derive(Copy, Clone, PartialEq, Eq)] pub enum FnKind<'a> { /// fn foo() or extern "Abi" fn foo() ItemFn(Name, &'a Generics, Unsafety, Constness, Abi, &'a Visibility, &'a [Attribute]), /// fn foo(&self) Method(Name, &'a MethodSig, Option<&'a Visibility>, &'a [Attribute]), /// |x, y| {} Closure(&'a [Attribute]), } impl<'a> FnKind<'a> { pub fn attrs(&self) -> &'a [Attribute] { match *self { FnKind::ItemFn(.., attrs) => attrs, FnKind::Method(.., attrs) => attrs, FnKind::Closure(attrs) => attrs, } } } /// Specifies what nested things a visitor wants to visit. The most /// common choice is `OnlyBodies`, which will cause the visitor to /// visit fn bodies for fns that it encounters, but skip over nested /// item-like things. /// /// See the comments on `ItemLikeVisitor` for more details on the overall /// visit strategy. pub enum NestedVisitorMap<'this, 'tcx: 'this> { /// Do not visit any nested things. When you add a new /// "non-nested" thing, you will want to audit such uses to see if /// they remain valid. /// /// Use this if you are only walking some particular kind of tree /// (i.e., a type, or fn signature) and you don't want to thread a /// HIR map around. None, /// Do not visit nested item-like things, but visit nested things /// that are inside of an item-like. /// /// **This is the most common choice.** A very common pattern is /// to use `visit_all_item_likes()` as an outer loop, /// and to have the visitor that visits the contents of each item /// using this setting. OnlyBodies(&'this Map<'tcx>), /// Visit all nested things, including item-likes. /// /// **This is an unusual choice.** It is used when you want to /// process everything within their lexical context. Typically you /// kick off the visit by doing `walk_krate()`. All(&'this Map<'tcx>), } impl<'this, 'tcx> NestedVisitorMap<'this, 'tcx> { /// Returns the map to use for an "intra item-like" thing (if any). /// e.g., function body. pub fn intra(self) -> Option<&'this Map<'tcx>> { match self { NestedVisitorMap::None => None, NestedVisitorMap::OnlyBodies(map) => Some(map), NestedVisitorMap::All(map) => Some(map), } } /// Returns the map to use for an "item-like" thing (if any). /// e.g., item, impl-item. pub fn inter(self) -> Option<&'this Map<'tcx>> { match self { NestedVisitorMap::None => None, NestedVisitorMap::OnlyBodies(_) => None, NestedVisitorMap::All(map) => Some(map), } } } /// 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. /// The default versions of the `visit_nested_XXX` routines invoke /// this method to get a map to use. By selecting an enum variant, /// you control which kinds of nested HIR are visited; see /// `NestedVisitorMap` for details. By "nested HIR", we are /// referring to bits of HIR that are not directly embedded within /// one another but rather indirectly, through a table in the /// crate. This is done to control dependencies during incremental /// compilation: the non-inline bits of HIR can be tracked and /// hashed separately. /// /// **If for some reason you want the nested behavior, but don't /// have a `Map` at your disposal:** then you should override the /// `visit_nested_XXX` methods, and override this method to /// `panic!()`. This way, if a new `visit_nested_XXX` variant is /// added in the future, we will see the panic in your code and /// fix it appropriately. fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'v>; /// Invoked when a nested item is encountered. By default does /// nothing unless you override `nested_visit_map` to return /// `Some(_)`, in which case it will walk the item. **You probably /// don't want to override this method** -- instead, override /// `nested_visit_map` or use the "shallow" or "deep" visit /// patterns described on `itemlikevisit::ItemLikeVisitor`. The only /// reason to override this method is if you want a nested pattern /// but cannot supply a `Map`; see `nested_visit_map` for advice. #[allow(unused_variables)] fn visit_nested_item(&mut self, id: ItemId) { let opt_item = self.nested_visit_map().inter().map(|map| map.expect_item(id.id)); if let Some(item) = opt_item { self.visit_item(item); } } /// Like `visit_nested_item()`, but for trait items. See /// `visit_nested_item()` for advice on when to override this /// method. #[allow(unused_variables)] fn visit_nested_trait_item(&mut self, id: TraitItemId) { let opt_item = self.nested_visit_map().inter().map(|map| map.trait_item(id)); if let Some(item) = opt_item { self.visit_trait_item(item); } } /// Like `visit_nested_item()`, but for impl items. See /// `visit_nested_item()` for advice on when to override this /// method. #[allow(unused_variables)] fn visit_nested_impl_item(&mut self, id: ImplItemId) { let opt_item = self.nested_visit_map().inter().map(|map| map.impl_item(id)); if let Some(item) = opt_item { self.visit_impl_item(item); } } /// Invoked to visit the body of a function, method or closure. Like /// visit_nested_item, does nothing by default unless you override /// `nested_visit_map` to return `Some(_)`, in which case it will walk the /// body. fn visit_nested_body(&mut self, id: BodyId) { let opt_body = self.nested_visit_map().intra().map(|map| map.body(id)); if let Some(body) = opt_body { self.visit_body(body); } } /// Visit the top-level item and (optionally) nested items / impl items. See /// `visit_nested_item` for details. fn visit_item(&mut self, i: &'v Item) { walk_item(self, i) } fn visit_body(&mut self, b: &'v Body) { walk_body(self, b); } /// When invoking `visit_all_item_likes()`, you need to supply an /// item-like visitor. This method converts a "intra-visit" /// visitor into an item-like visitor that walks the entire tree. /// If you use this, you probably don't want to process the /// contents of nested item-like things, since the outer loop will /// visit them as well. fn as_deep_visitor<'s>(&'s mut self) -> DeepVisitor<'s, Self> { DeepVisitor::new(self) } /////////////////////////////////////////////////////////////////////////// fn visit_id(&mut self, _node_id: NodeId) { // Nothing to do. } fn visit_def_mention(&mut self, _def: Def) { // Nothing to do. } fn visit_name(&mut self, _span: Span, _name: Name) { // Nothing to do. } fn visit_ident(&mut self, ident: Ident) { walk_ident(self, ident) } fn visit_mod(&mut self, m: &'v Mod, _s: Span, n: NodeId) { walk_mod(self, m, n) } 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_anon_const(&mut self, c: &'v AnonConst) { walk_anon_const(self, c) } fn visit_expr(&mut self, ex: &'v Expr) { walk_expr(self, ex) } fn visit_ty(&mut self, t: &'v Ty) { walk_ty(self, t) } fn visit_generic_param(&mut self, p: &'v GenericParam) { walk_generic_param(self, p) } fn visit_generics(&mut self, g: &'v Generics) { walk_generics(self, g) } fn visit_where_predicate(&mut self, predicate: &'v WherePredicate) { walk_where_predicate(self, predicate) } fn visit_fn_decl(&mut self, fd: &'v FnDecl) { walk_fn_decl(self, fd) } fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl, b: BodyId, s: Span, id: NodeId) { walk_fn(self, fk, fd, b, s, id) } fn visit_trait_item(&mut self, ti: &'v TraitItem) { walk_trait_item(self, ti) } fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) { walk_trait_item_ref(self, ii) } fn visit_impl_item(&mut self, ii: &'v ImplItem) { walk_impl_item(self, ii) } fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef) { walk_impl_item_ref(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: TraitBoundModifier) { walk_poly_trait_ref(self, t, m) } fn visit_variant_data(&mut self, s: &'v VariantData, _: Name, _: &'v Generics, _parent_id: 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_label(&mut self, label: &'v Label) { walk_label(self, label) } fn visit_generic_arg(&mut self, generic_arg: &'v GenericArg) { match generic_arg { GenericArg::Lifetime(lt) => self.visit_lifetime(lt), GenericArg::Type(ty) => self.visit_ty(ty), } } fn visit_lifetime(&mut self, lifetime: &'v Lifetime) { walk_lifetime(self, lifetime) } fn visit_qpath(&mut self, qpath: &'v QPath, id: NodeId, span: Span) { walk_qpath(self, qpath, id, span) } fn visit_path(&mut self, path: &'v Path, _id: NodeId) { walk_path(self, path) } fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment) { walk_path_segment(self, path_span, path_segment) } fn visit_generic_args(&mut self, path_span: Span, generic_args: &'v GenericArgs) { walk_generic_args(self, path_span, generic_args) } 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) } fn visit_vis(&mut self, vis: &'v Visibility) { walk_vis(self, vis) } fn visit_associated_item_kind(&mut self, kind: &'v AssociatedItemKind) { walk_associated_item_kind(self, kind); } fn visit_defaultness(&mut self, defaultness: &'v Defaultness) { walk_defaultness(self, defaultness); } } /// 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_id(macro_def.id); visitor.visit_name(macro_def.span, macro_def.name); walk_list!(visitor, visit_attribute, ¯o_def.attrs); } pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod, mod_node_id: NodeId) { visitor.visit_id(mod_node_id); for &item_id in &module.item_ids { visitor.visit_nested_item(item_id); } } pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body) { for argument in &body.arguments { visitor.visit_id(argument.id); visitor.visit_pat(&argument.pat); } visitor.visit_expr(&body.value); } pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local) { // Intentionally visiting the expr first - the initialization expr // dominates the local's definition. walk_list!(visitor, visit_expr, &local.init); walk_list!(visitor, visit_attribute, local.attrs.iter()); visitor.visit_id(local.id); visitor.visit_pat(&local.pat); walk_list!(visitor, visit_ty, &local.ty); } pub fn walk_ident<'v, V: Visitor<'v>>(visitor: &mut V, ident: Ident) { visitor.visit_name(ident.span, ident.name); } pub fn walk_label<'v, V: Visitor<'v>>(visitor: &mut V, label: &'v Label) { visitor.visit_name(label.span, label.name); } pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) { visitor.visit_id(lifetime.id); match lifetime.name { LifetimeName::Name(name) => { visitor.visit_name(lifetime.span, name); } LifetimeName::Fresh(_) | LifetimeName::Static | LifetimeName::Implicit | LifetimeName::Underscore => {} } } pub fn walk_poly_trait_ref<'v, V>(visitor: &mut V, trait_ref: &'v PolyTraitRef, _modifier: TraitBoundModifier) where V: Visitor<'v> { walk_list!(visitor, visit_generic_param, &trait_ref.bound_generic_params); 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_id(trait_ref.ref_id); 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_vis(&item.vis); visitor.visit_name(item.span, item.name); match item.node { ItemExternCrate(orig_name) => { visitor.visit_id(item.id); if let Some(orig_name) = orig_name { visitor.visit_name(item.span, orig_name); } } ItemUse(ref path, _) => { visitor.visit_id(item.id); visitor.visit_path(path, item.id); } ItemStatic(ref typ, _, body) | ItemConst(ref typ, body) => { visitor.visit_id(item.id); visitor.visit_ty(typ); visitor.visit_nested_body(body); } ItemFn(ref declaration, unsafety, constness, abi, ref generics, body_id) => { visitor.visit_fn(FnKind::ItemFn(item.name, generics, unsafety, constness, abi, &item.vis, &item.attrs), declaration, body_id, item.span, item.id) } ItemMod(ref module) => { // visit_mod() takes care of visiting the Item's NodeId visitor.visit_mod(module, item.span, item.id) } ItemForeignMod(ref foreign_module) => { visitor.visit_id(item.id); walk_list!(visitor, visit_foreign_item, &foreign_module.items); } ItemGlobalAsm(_) => { visitor.visit_id(item.id); } ItemTy(ref typ, ref type_parameters) => { visitor.visit_id(item.id); visitor.visit_ty(typ); visitor.visit_generics(type_parameters) } ItemExistential(ExistTy {ref generics, ref bounds, impl_trait_fn}) => { visitor.visit_id(item.id); walk_generics(visitor, generics); walk_list!(visitor, visit_ty_param_bound, bounds); if let Some(impl_trait_fn) = impl_trait_fn { visitor.visit_def_mention(Def::Fn(impl_trait_fn)) } } ItemEnum(ref enum_definition, ref type_parameters) => { visitor.visit_generics(type_parameters); // visit_enum_def() takes care of visiting the Item's NodeId visitor.visit_enum_def(enum_definition, type_parameters, item.id, item.span) } ItemImpl(.., ref type_parameters, ref opt_trait_reference, ref typ, ref impl_item_refs) => { visitor.visit_id(item.id); visitor.visit_generics(type_parameters); walk_list!(visitor, visit_trait_ref, opt_trait_reference); visitor.visit_ty(typ); walk_list!(visitor, visit_impl_item_ref, impl_item_refs); } ItemStruct(ref struct_definition, ref generics) | ItemUnion(ref struct_definition, ref generics) => { visitor.visit_generics(generics); visitor.visit_id(item.id); visitor.visit_variant_data(struct_definition, item.name, generics, item.id, item.span); } ItemTrait(.., ref generics, ref bounds, ref trait_item_refs) => { visitor.visit_id(item.id); visitor.visit_generics(generics); walk_list!(visitor, visit_ty_param_bound, bounds); walk_list!(visitor, visit_trait_item_ref, trait_item_refs); } ItemTraitAlias(ref generics, ref bounds) => { visitor.visit_id(item.id); visitor.visit_generics(generics); walk_list!(visitor, visit_ty_param_bound, bounds); } } 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) { visitor.visit_id(item_id); 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, parent_item_id: NodeId) { visitor.visit_name(variant.span, variant.node.name); visitor.visit_variant_data(&variant.node.data, variant.node.name, generics, parent_item_id, variant.span); walk_list!(visitor, visit_anon_const, &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) { visitor.visit_id(typ.id); match typ.node { TySlice(ref ty) => { visitor.visit_ty(ty) } TyPtr(ref mutable_type) => { visitor.visit_ty(&mutable_type.ty) } TyRptr(ref lifetime, ref mutable_type) => { visitor.visit_lifetime(lifetime); visitor.visit_ty(&mutable_type.ty) } TyNever => {}, TyTup(ref tuple_element_types) => { walk_list!(visitor, visit_ty, tuple_element_types); } TyBareFn(ref function_declaration) => { walk_list!(visitor, visit_generic_param, &function_declaration.generic_params); visitor.visit_fn_decl(&function_declaration.decl); } TyPath(ref qpath) => { visitor.visit_qpath(qpath, typ.id, typ.span); } TyArray(ref ty, ref length) => { visitor.visit_ty(ty); visitor.visit_anon_const(length) } TyTraitObject(ref bounds, ref lifetime) => { for bound in bounds { visitor.visit_poly_trait_ref(bound, TraitBoundModifier::None); } visitor.visit_lifetime(lifetime); } TyImplTraitExistential(item_id, def_id, ref lifetimes) => { visitor.visit_def_mention(Def::Existential(def_id)); visitor.visit_nested_item(item_id); walk_list!(visitor, visit_lifetime, lifetimes); } TyTypeof(ref expression) => { visitor.visit_anon_const(expression) } TyInfer | TyErr => {} } } pub fn walk_qpath<'v, V: Visitor<'v>>(visitor: &mut V, qpath: &'v QPath, id: NodeId, span: Span) { match *qpath { QPath::Resolved(ref maybe_qself, ref path) => { if let Some(ref qself) = *maybe_qself { visitor.visit_ty(qself); } visitor.visit_path(path, id) } QPath::TypeRelative(ref qself, ref segment) => { visitor.visit_ty(qself); visitor.visit_path_segment(span, segment); } } } pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path) { visitor.visit_def_mention(path.def); for segment in &path.segments { visitor.visit_path_segment(path.span, segment); } } pub fn walk_path_segment<'v, V: Visitor<'v>>(visitor: &mut V, path_span: Span, segment: &'v PathSegment) { visitor.visit_name(path_span, segment.name); if let Some(ref args) = segment.args { visitor.visit_generic_args(path_span, args); } } pub fn walk_generic_args<'v, V: Visitor<'v>>(visitor: &mut V, _path_span: Span, generic_args: &'v GenericArgs) { walk_list!(visitor, visit_generic_arg, &generic_args.args); walk_list!(visitor, visit_assoc_type_binding, &generic_args.bindings); } pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(visitor: &mut V, type_binding: &'v TypeBinding) { visitor.visit_id(type_binding.id); 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) { visitor.visit_id(pattern.id); match pattern.node { PatKind::TupleStruct(ref qpath, ref children, _) => { visitor.visit_qpath(qpath, pattern.id, pattern.span); walk_list!(visitor, visit_pat, children); } PatKind::Path(ref qpath) => { visitor.visit_qpath(qpath, pattern.id, pattern.span); } PatKind::Struct(ref qpath, ref fields, _) => { visitor.visit_qpath(qpath, pattern.id, pattern.span); for field in fields { visitor.visit_id(field.node.id); visitor.visit_ident(field.node.ident); visitor.visit_pat(&field.node.pat) } } PatKind::Tuple(ref tuple_elements, _) => { walk_list!(visitor, visit_pat, tuple_elements); } PatKind::Box(ref subpattern) | PatKind::Ref(ref subpattern, _) => { visitor.visit_pat(subpattern) } PatKind::Binding(_, canonical_id, ref pth1, ref optional_subpattern) => { visitor.visit_def_mention(Def::Local(canonical_id)); visitor.visit_name(pth1.span, pth1.node); walk_list!(visitor, visit_pat, optional_subpattern); } PatKind::Lit(ref expression) => visitor.visit_expr(expression), PatKind::Range(ref lower_bound, ref upper_bound, _) => { visitor.visit_expr(lower_bound); visitor.visit_expr(upper_bound) } PatKind::Wild => (), PatKind::Slice(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_id(foreign_item.id); visitor.visit_vis(&foreign_item.vis); visitor.visit_name(foreign_item.span, foreign_item.name); match foreign_item.node { ForeignItemFn(ref function_declaration, ref names, ref generics) => { visitor.visit_generics(generics); visitor.visit_fn_decl(function_declaration); for name in names { visitor.visit_name(name.span, name.node); } } ForeignItemStatic(ref typ, _) => visitor.visit_ty(typ), ForeignItemType => (), } 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, modifier) => { visitor.visit_poly_trait_ref(typ, modifier); } RegionTyParamBound(ref lifetime) => { visitor.visit_lifetime(lifetime); } } } pub fn walk_generic_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v GenericParam) { visitor.visit_id(param.id); match param.kind { GenericParamKind::Lifetime { ref bounds, ref lifetime_deprecated, .. } => { match lifetime_deprecated.name { LifetimeName::Name(name) => { visitor.visit_name(param.span, name); } LifetimeName::Fresh(_) | LifetimeName::Static | LifetimeName::Implicit | LifetimeName::Underscore => {} } walk_list!(visitor, visit_lifetime, bounds); } GenericParamKind::Type { name, ref bounds, ref default, ref attrs, .. } => { visitor.visit_name(param.span, name); walk_list!(visitor, visit_ty_param_bound, bounds); walk_list!(visitor, visit_ty, default); walk_list!(visitor, visit_attribute, attrs.iter()); } } } pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics) { walk_list!(visitor, visit_generic_param, &generics.params); visitor.visit_id(generics.where_clause.id); walk_list!(visitor, visit_where_predicate, &generics.where_clause.predicates); } pub fn walk_where_predicate<'v, V: Visitor<'v>>( visitor: &mut V, predicate: &'v WherePredicate) { match predicate { &WherePredicate::BoundPredicate(WhereBoundPredicate{ref bounded_ty, ref bounds, ref bound_generic_params, ..}) => { visitor.visit_ty(bounded_ty); walk_list!(visitor, visit_ty_param_bound, bounds); walk_list!(visitor, visit_generic_param, bound_generic_params); } &WherePredicate::RegionPredicate(WhereRegionPredicate{ref lifetime, ref bounds, ..}) => { visitor.visit_lifetime(lifetime); walk_list!(visitor, visit_lifetime, bounds); } &WherePredicate::EqPredicate(WhereEqPredicate{id, ref lhs_ty, ref rhs_ty, ..}) => { visitor.visit_id(id); visitor.visit_ty(lhs_ty); visitor.visit_ty(rhs_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 ty in &function_declaration.inputs { visitor.visit_ty(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(..) | FnKind::Closure(_) => {} } } pub fn walk_fn<'v, V: Visitor<'v>>(visitor: &mut V, function_kind: FnKind<'v>, function_declaration: &'v FnDecl, body_id: BodyId, _span: Span, id: NodeId) { visitor.visit_id(id); visitor.visit_fn_decl(function_declaration); walk_fn_kind(visitor, function_kind); visitor.visit_nested_body(body_id) } 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); visitor.visit_generics(&trait_item.generics); match trait_item.node { TraitItemKind::Const(ref ty, default) => { visitor.visit_id(trait_item.id); visitor.visit_ty(ty); walk_list!(visitor, visit_nested_body, default); } TraitItemKind::Method(ref sig, TraitMethod::Required(ref names)) => { visitor.visit_id(trait_item.id); visitor.visit_fn_decl(&sig.decl); for name in names { visitor.visit_name(name.span, name.node); } } TraitItemKind::Method(ref sig, TraitMethod::Provided(body_id)) => { visitor.visit_fn(FnKind::Method(trait_item.name, sig, None, &trait_item.attrs), &sig.decl, body_id, trait_item.span, trait_item.id); } TraitItemKind::Type(ref bounds, ref default) => { visitor.visit_id(trait_item.id); walk_list!(visitor, visit_ty_param_bound, bounds); walk_list!(visitor, visit_ty, default); } } } pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref: &'v TraitItemRef) { // NB: Deliberately force a compilation error if/when new fields are added. let TraitItemRef { id, name, ref kind, span, ref defaultness } = *trait_item_ref; visitor.visit_nested_trait_item(id); visitor.visit_name(span, name); visitor.visit_associated_item_kind(kind); visitor.visit_defaultness(defaultness); } pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem) { // NB: Deliberately force a compilation error if/when new fields are added. let ImplItem { id: _, hir_id: _, name, ref vis, ref defaultness, ref attrs, ref generics, ref node, span } = *impl_item; visitor.visit_name(span, name); visitor.visit_vis(vis); visitor.visit_defaultness(defaultness); walk_list!(visitor, visit_attribute, attrs); visitor.visit_generics(generics); match *node { ImplItemKind::Const(ref ty, body) => { visitor.visit_id(impl_item.id); visitor.visit_ty(ty); visitor.visit_nested_body(body); } ImplItemKind::Method(ref sig, body_id) => { visitor.visit_fn(FnKind::Method(impl_item.name, sig, Some(&impl_item.vis), &impl_item.attrs), &sig.decl, body_id, impl_item.span, impl_item.id); } ImplItemKind::Type(ref ty) => { visitor.visit_id(impl_item.id); visitor.visit_ty(ty); } } } pub fn walk_impl_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, impl_item_ref: &'v ImplItemRef) { // NB: Deliberately force a compilation error if/when new fields are added. let ImplItemRef { id, name, ref kind, span, ref vis, ref defaultness } = *impl_item_ref; visitor.visit_nested_impl_item(id); visitor.visit_name(span, name); visitor.visit_associated_item_kind(kind); visitor.visit_vis(vis); visitor.visit_defaultness(defaultness); } pub fn walk_struct_def<'v, V: Visitor<'v>>(visitor: &mut V, struct_definition: &'v VariantData) { visitor.visit_id(struct_definition.id()); 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) { visitor.visit_id(struct_field.id); visitor.visit_vis(&struct_field.vis); visitor.visit_ident(struct_field.ident); visitor.visit_ty(&struct_field.ty); walk_list!(visitor, visit_attribute, &struct_field.attrs); } pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block) { visitor.visit_id(block.id); 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, id) => { visitor.visit_id(id); visitor.visit_decl(declaration) } StmtExpr(ref expression, id) | StmtSemi(ref expression, id) => { visitor.visit_id(id); 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_anon_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v AnonConst) { visitor.visit_id(constant.id); visitor.visit_nested_body(constant.body); } pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) { visitor.visit_id(expression.id); walk_list!(visitor, visit_attribute, expression.attrs.iter()); match expression.node { ExprBox(ref subexpression) => { visitor.visit_expr(subexpression) } ExprArray(ref subexpressions) => { walk_list!(visitor, visit_expr, subexpressions); } ExprRepeat(ref element, ref count) => { visitor.visit_expr(element); visitor.visit_anon_const(count) } ExprStruct(ref qpath, ref fields, ref optional_base) => { visitor.visit_qpath(qpath, expression.id, expression.span); for field in fields { visitor.visit_id(field.id); visitor.visit_ident(field.ident); 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) => { visitor.visit_expr(callee_expression); walk_list!(visitor, visit_expr, arguments); } ExprMethodCall(ref segment, _, ref arguments) => { visitor.visit_path_segment(expression.span, segment); walk_list!(visitor, visit_expr, arguments); } 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_expr(if_block); walk_list!(visitor, visit_expr, optional_else); } ExprWhile(ref subexpression, ref block, ref opt_label) => { walk_list!(visitor, visit_label, opt_label); visitor.visit_expr(subexpression); visitor.visit_block(block); } ExprLoop(ref block, ref opt_label, _) => { walk_list!(visitor, visit_label, opt_label); visitor.visit_block(block); } ExprMatch(ref subexpression, ref arms, _) => { visitor.visit_expr(subexpression); walk_list!(visitor, visit_arm, arms); } ExprClosure(_, ref function_declaration, body, _fn_decl_span, _gen) => { visitor.visit_fn(FnKind::Closure(&expression.attrs), function_declaration, body, expression.span, expression.id) } ExprBlock(ref block, ref opt_label) => { walk_list!(visitor, visit_label, opt_label); 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, ident) => { visitor.visit_expr(subexpression); visitor.visit_ident(ident); } ExprIndex(ref main_expression, ref index_expression) => { visitor.visit_expr(main_expression); visitor.visit_expr(index_expression) } ExprPath(ref qpath) => { visitor.visit_qpath(qpath, expression.id, expression.span); } ExprBreak(ref destination, ref opt_expr) => { if let Some(ref label) = destination.label { visitor.visit_label(label); match destination.target_id { Ok(node_id) => visitor.visit_def_mention(Def::Label(node_id)), Err(_) => {}, }; } walk_list!(visitor, visit_expr, opt_expr); } ExprAgain(ref destination) => { if let Some(ref label) = destination.label { visitor.visit_label(label); match destination.target_id { Ok(node_id) => visitor.visit_def_mention(Def::Label(node_id)), Err(_) => {}, }; } } ExprRet(ref optional_expression) => { walk_list!(visitor, visit_expr, optional_expression); } ExprInlineAsm(_, ref outputs, ref inputs) => { for output in outputs { visitor.visit_expr(output) } for input in inputs { visitor.visit_expr(input) } } ExprYield(ref subexpression) => { visitor.visit_expr(subexpression); } } } 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); } pub fn walk_vis<'v, V: Visitor<'v>>(visitor: &mut V, vis: &'v Visibility) { if let Visibility::Restricted { ref path, id } = *vis { visitor.visit_id(id); visitor.visit_path(path, id) } } pub fn walk_associated_item_kind<'v, V: Visitor<'v>>(_: &mut V, _: &'v AssociatedItemKind) { // No visitable content here: this fn exists so you can call it if // the right thing to do, should content be added in the future, // would be to walk it. } pub fn walk_defaultness<'v, V: Visitor<'v>>(_: &mut V, _: &'v Defaultness) { // No visitable content here: this fn exists so you can call it if // the right thing to do, should content be added in the future, // would be to walk it. } #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug, PartialEq, Eq)] pub struct IdRange { pub min: NodeId, pub max: NodeId, } impl IdRange { pub fn max() -> IdRange { IdRange { min: NodeId::from_u32(u32::MAX), max: NodeId::from_u32(u32::MIN), } } pub fn empty(&self) -> bool { self.min >= self.max } pub fn contains(&self, id: NodeId) -> bool { id >= self.min && id < self.max } pub fn add(&mut self, id: NodeId) { self.min = cmp::min(self.min, id); self.max = cmp::max(self.max, NodeId::from_u32(id.as_u32() + 1)); } } pub struct IdRangeComputingVisitor<'a, 'hir: 'a> { result: IdRange, map: &'a map::Map<'hir>, } impl<'a, 'hir> IdRangeComputingVisitor<'a, 'hir> { pub fn new(map: &'a map::Map<'hir>) -> IdRangeComputingVisitor<'a, 'hir> { IdRangeComputingVisitor { result: IdRange::max(), map: map } } pub fn result(&self) -> IdRange { self.result } } impl<'a, 'hir> Visitor<'hir> for IdRangeComputingVisitor<'a, 'hir> { fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'hir> { NestedVisitorMap::OnlyBodies(&self.map) } fn visit_id(&mut self, id: NodeId) { self.result.add(id); } }