1 // Copyright 2012-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! HIR walker for walking the contents of nodes.
13 //! **For an overview of the visitor strategy, see the docs on the
14 //! `super::itemlikevisit::ItemLikeVisitor` trait.**
16 //! If you have decided to use this visitor, here are some general
17 //! notes on how to do it:
19 //! Each overridden visit method has full control over what
20 //! happens with its node, it can do its own traversal of the node's children,
21 //! call `intravisit::walk_*` to apply the default traversal algorithm, or prevent
22 //! deeper traversal by doing nothing.
24 //! When visiting the HIR, the contents of nested items are NOT visited
25 //! by default. This is different from the AST visitor, which does a deep walk.
26 //! Hence this module is called `intravisit`; see the method `visit_nested_item`
29 //! Note: it is an important invariant that the default visitor walks
30 //! the body of a function in "execution order" (more concretely,
31 //! reverse post-order with respect to the CFG implied by the AST),
32 //! meaning that if AST node A may execute before AST node B, then A
33 //! is visited first. The borrow checker in particular relies on this
37 use syntax::ast::{NodeId, CRATE_NODE_ID, Name, Attribute};
38 use syntax::codemap::Spanned;
43 use super::itemlikevisit::DeepVisitor;
48 #[derive(Copy, Clone, PartialEq, Eq)]
50 /// fn foo() or extern "Abi" fn foo()
51 ItemFn(Name, &'a Generics, Unsafety, Constness, Abi, &'a Visibility, &'a [Attribute]),
54 Method(Name, &'a MethodSig, Option<&'a Visibility>, &'a [Attribute]),
57 Closure(&'a [Attribute]),
61 pub fn attrs(&self) -> &'a [Attribute] {
63 FnKind::ItemFn(.., attrs) => attrs,
64 FnKind::Method(.., attrs) => attrs,
65 FnKind::Closure(attrs) => attrs,
70 /// Specifies what nested things a visitor wants to visit. The most
71 /// common choice is `OnlyBodies`, which will cause the visitor to
72 /// visit fn bodies for fns that it encounters, but skip over nested
75 /// See the comments on `ItemLikeVisitor` for more details on the overall
77 pub enum NestedVisitorMap<'this, 'tcx: 'this> {
78 /// Do not visit any nested things. When you add a new
79 /// "non-nested" thing, you will want to audit such uses to see if
80 /// they remain valid.
82 /// Use this if you are only walking some particular kind of tree
83 /// (i.e., a type, or fn signature) and you don't want to thread a
87 /// Do not visit nested item-like things, but visit nested things
88 /// that are inside of an item-like.
90 /// **This is the most common choice.** A very commmon pattern is
91 /// to use `tcx.visit_all_item_likes_in_krate()` as an outer loop,
92 /// and to have the visitor that visits the contents of each item
93 /// using this setting.
94 OnlyBodies(&'this Map<'tcx>),
96 /// Visit all nested things, including item-likes.
98 /// **This is an unusual choice.** It is used when you want to
99 /// process everything within their lexical context. Typically you
100 /// kick off the visit by doing `walk_krate()`.
101 All(&'this Map<'tcx>),
104 impl<'this, 'tcx> NestedVisitorMap<'this, 'tcx> {
105 /// Returns the map to use for an "intra item-like" thing (if any).
106 /// e.g., function body.
107 pub fn intra(self) -> Option<&'this Map<'tcx>> {
109 NestedVisitorMap::None => None,
110 NestedVisitorMap::OnlyBodies(map) => Some(map),
111 NestedVisitorMap::All(map) => Some(map),
115 /// Returns the map to use for an "item-like" thing (if any).
116 /// e.g., item, impl-item.
117 pub fn inter(self) -> Option<&'this Map<'tcx>> {
119 NestedVisitorMap::None => None,
120 NestedVisitorMap::OnlyBodies(_) => None,
121 NestedVisitorMap::All(map) => Some(map),
126 /// Each method of the Visitor trait is a hook to be potentially
127 /// overridden. Each method's default implementation recursively visits
128 /// the substructure of the input via the corresponding `walk` method;
129 /// e.g. the `visit_mod` method by default calls `intravisit::walk_mod`.
131 /// Note that this visitor does NOT visit nested items by default
132 /// (this is why the module is called `intravisit`, to distinguish it
133 /// from the AST's `visit` module, which acts differently). If you
134 /// simply want to visit all items in the crate in some order, you
135 /// should call `Crate::visit_all_items`. Otherwise, see the comment
136 /// on `visit_nested_item` for details on how to visit nested items.
138 /// If you want to ensure that your code handles every variant
139 /// explicitly, you need to override each method. (And you also need
140 /// to monitor future changes to `Visitor` in case a new method with a
141 /// new default implementation gets introduced.)
142 pub trait Visitor<'v> : Sized {
143 ///////////////////////////////////////////////////////////////////////////
146 /// The default versions of the `visit_nested_XXX` routines invoke
147 /// this method to get a map to use. By selecting an enum variant,
148 /// you control which kinds of nested HIR are visited; see
149 /// `NestedVisitorMap` for details. By "nested HIR", we are
150 /// referring to bits of HIR that are not directly embedded within
151 /// one another but rather indirectly, through a table in the
152 /// crate. This is done to control dependencies during incremental
153 /// compilation: the non-inline bits of HIR can be tracked and
154 /// hashed separately.
156 /// **If for some reason you want the nested behavior, but don't
157 /// have a `Map` are your disposal:** then you should override the
158 /// `visit_nested_XXX` methods, and override this method to
159 /// `panic!()`. This way, if a new `visit_nested_XXX` variant is
160 /// added in the future, we will see the panic in your code and
161 /// fix it appropriately.
162 fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'v>;
164 /// Invoked when a nested item is encountered. By default does
165 /// nothing unless you override `nested_visit_map` to return
166 /// `Some(_)`, in which case it will walk the item. **You probably
167 /// don't want to override this method** -- instead, override
168 /// `nested_visit_map` or use the "shallow" or "deep" visit
169 /// patterns described on `itemlikevisit::ItemLikeVisitor`. The only
170 /// reason to override this method is if you want a nested pattern
171 /// but cannot supply a `Map`; see `nested_visit_map` for advice.
172 #[allow(unused_variables)]
173 fn visit_nested_item(&mut self, id: ItemId) {
174 let opt_item = self.nested_visit_map().inter().map(|map| map.expect_item(id.id));
175 if let Some(item) = opt_item {
176 self.visit_item(item);
180 /// Like `visit_nested_item()`, but for trait items. See
181 /// `visit_nested_item()` for advice on when to override this
183 #[allow(unused_variables)]
184 fn visit_nested_trait_item(&mut self, id: TraitItemId) {
185 let opt_item = self.nested_visit_map().inter().map(|map| map.trait_item(id));
186 if let Some(item) = opt_item {
187 self.visit_trait_item(item);
191 /// Like `visit_nested_item()`, but for impl items. See
192 /// `visit_nested_item()` for advice on when to override this
194 #[allow(unused_variables)]
195 fn visit_nested_impl_item(&mut self, id: ImplItemId) {
196 let opt_item = self.nested_visit_map().inter().map(|map| map.impl_item(id));
197 if let Some(item) = opt_item {
198 self.visit_impl_item(item);
202 /// Invoked to visit the body of a function, method or closure. Like
203 /// visit_nested_item, does nothing by default unless you override
204 /// `nested_visit_map` to return `Some(_)`, in which case it will walk the
206 fn visit_nested_body(&mut self, id: BodyId) {
207 let opt_body = self.nested_visit_map().intra().map(|map| map.body(id));
208 if let Some(body) = opt_body {
209 self.visit_body(body);
213 /// Visit the top-level item and (optionally) nested items / impl items. See
214 /// `visit_nested_item` for details.
215 fn visit_item(&mut self, i: &'v Item) {
219 fn visit_body(&mut self, b: &'v Body) {
223 /// When invoking `visit_all_item_likes()`, you need to supply an
224 /// item-like visitor. This method converts a "intra-visit"
225 /// visitor into an item-like visitor that walks the entire tree.
226 /// If you use this, you probably don't want to process the
227 /// contents of nested item-like things, since the outer loop will
228 /// visit them as well.
229 fn as_deep_visitor<'s>(&'s mut self) -> DeepVisitor<'s, Self> {
230 DeepVisitor::new(self)
233 ///////////////////////////////////////////////////////////////////////////
235 fn visit_id(&mut self, _node_id: NodeId) {
238 fn visit_def_mention(&mut self, _def: Def) {
241 fn visit_name(&mut self, _span: Span, _name: Name) {
244 fn visit_mod(&mut self, m: &'v Mod, _s: Span, n: NodeId) {
247 fn visit_foreign_item(&mut self, i: &'v ForeignItem) {
248 walk_foreign_item(self, i)
250 fn visit_local(&mut self, l: &'v Local) {
253 fn visit_block(&mut self, b: &'v Block) {
256 fn visit_stmt(&mut self, s: &'v Stmt) {
259 fn visit_arm(&mut self, a: &'v Arm) {
262 fn visit_pat(&mut self, p: &'v Pat) {
265 fn visit_decl(&mut self, d: &'v Decl) {
268 fn visit_expr(&mut self, ex: &'v Expr) {
271 fn visit_ty(&mut self, t: &'v Ty) {
274 fn visit_generics(&mut self, g: &'v Generics) {
275 walk_generics(self, g)
277 fn visit_where_predicate(&mut self, predicate: &'v WherePredicate) {
278 walk_where_predicate(self, predicate)
280 fn visit_fn_decl(&mut self, fd: &'v FnDecl) {
281 walk_fn_decl(self, fd)
283 fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl, b: BodyId, s: Span, id: NodeId) {
284 walk_fn(self, fk, fd, b, s, id)
286 fn visit_trait_item(&mut self, ti: &'v TraitItem) {
287 walk_trait_item(self, ti)
289 fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) {
290 walk_trait_item_ref(self, ii)
292 fn visit_impl_item(&mut self, ii: &'v ImplItem) {
293 walk_impl_item(self, ii)
295 fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef) {
296 walk_impl_item_ref(self, ii)
298 fn visit_trait_ref(&mut self, t: &'v TraitRef) {
299 walk_trait_ref(self, t)
301 fn visit_ty_param_bound(&mut self, bounds: &'v TyParamBound) {
302 walk_ty_param_bound(self, bounds)
304 fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef, m: &'v TraitBoundModifier) {
305 walk_poly_trait_ref(self, t, m)
307 fn visit_variant_data(&mut self,
313 walk_struct_def(self, s)
315 fn visit_struct_field(&mut self, s: &'v StructField) {
316 walk_struct_field(self, s)
318 fn visit_enum_def(&mut self,
319 enum_definition: &'v EnumDef,
320 generics: &'v Generics,
323 walk_enum_def(self, enum_definition, generics, item_id)
325 fn visit_variant(&mut self, v: &'v Variant, g: &'v Generics, item_id: NodeId) {
326 walk_variant(self, v, g, item_id)
328 fn visit_lifetime(&mut self, lifetime: &'v Lifetime) {
329 walk_lifetime(self, lifetime)
331 fn visit_lifetime_def(&mut self, lifetime: &'v LifetimeDef) {
332 walk_lifetime_def(self, lifetime)
334 fn visit_qpath(&mut self, qpath: &'v QPath, id: NodeId, span: Span) {
335 walk_qpath(self, qpath, id, span)
337 fn visit_path(&mut self, path: &'v Path, _id: NodeId) {
338 walk_path(self, path)
340 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment) {
341 walk_path_segment(self, path_span, path_segment)
343 fn visit_path_parameters(&mut self, path_span: Span, path_parameters: &'v PathParameters) {
344 walk_path_parameters(self, path_span, path_parameters)
346 fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding) {
347 walk_assoc_type_binding(self, type_binding)
349 fn visit_attribute(&mut self, _attr: &'v Attribute) {
351 fn visit_macro_def(&mut self, macro_def: &'v MacroDef) {
352 walk_macro_def(self, macro_def)
354 fn visit_vis(&mut self, vis: &'v Visibility) {
357 fn visit_associated_item_kind(&mut self, kind: &'v AssociatedItemKind) {
358 walk_associated_item_kind(self, kind);
360 fn visit_defaultness(&mut self, defaultness: &'v Defaultness) {
361 walk_defaultness(self, defaultness);
365 pub fn walk_opt_name<'v, V: Visitor<'v>>(visitor: &mut V, span: Span, opt_name: Option<Name>) {
366 if let Some(name) = opt_name {
367 visitor.visit_name(span, name);
371 pub fn walk_opt_sp_name<'v, V: Visitor<'v>>(visitor: &mut V, opt_sp_name: &Option<Spanned<Name>>) {
372 if let Some(ref sp_name) = *opt_sp_name {
373 visitor.visit_name(sp_name.span, sp_name.node);
377 /// Walks the contents of a crate. See also `Crate::visit_all_items`.
378 pub fn walk_crate<'v, V: Visitor<'v>>(visitor: &mut V, krate: &'v Crate) {
379 visitor.visit_mod(&krate.module, krate.span, CRATE_NODE_ID);
380 walk_list!(visitor, visit_attribute, &krate.attrs);
381 walk_list!(visitor, visit_macro_def, &krate.exported_macros);
384 pub fn walk_macro_def<'v, V: Visitor<'v>>(visitor: &mut V, macro_def: &'v MacroDef) {
385 visitor.visit_id(macro_def.id);
386 visitor.visit_name(macro_def.span, macro_def.name);
387 walk_list!(visitor, visit_attribute, ¯o_def.attrs);
390 pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod, mod_node_id: NodeId) {
391 visitor.visit_id(mod_node_id);
392 for &item_id in &module.item_ids {
393 visitor.visit_nested_item(item_id);
397 pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body) {
398 for argument in &body.arguments {
399 visitor.visit_id(argument.id);
400 visitor.visit_pat(&argument.pat);
402 visitor.visit_expr(&body.value);
405 pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local) {
406 visitor.visit_id(local.id);
407 visitor.visit_pat(&local.pat);
408 walk_list!(visitor, visit_ty, &local.ty);
409 walk_list!(visitor, visit_expr, &local.init);
412 pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) {
413 visitor.visit_id(lifetime.id);
414 visitor.visit_name(lifetime.span, lifetime.name);
417 pub fn walk_lifetime_def<'v, V: Visitor<'v>>(visitor: &mut V, lifetime_def: &'v LifetimeDef) {
418 visitor.visit_lifetime(&lifetime_def.lifetime);
419 walk_list!(visitor, visit_lifetime, &lifetime_def.bounds);
422 pub fn walk_poly_trait_ref<'v, V>(visitor: &mut V,
423 trait_ref: &'v PolyTraitRef,
424 _modifier: &'v TraitBoundModifier)
427 walk_list!(visitor, visit_lifetime_def, &trait_ref.bound_lifetimes);
428 visitor.visit_trait_ref(&trait_ref.trait_ref);
431 pub fn walk_trait_ref<'v, V>(visitor: &mut V, trait_ref: &'v TraitRef)
434 visitor.visit_id(trait_ref.ref_id);
435 visitor.visit_path(&trait_ref.path, trait_ref.ref_id)
438 pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {
439 visitor.visit_vis(&item.vis);
440 visitor.visit_name(item.span, item.name);
442 ItemExternCrate(opt_name) => {
443 visitor.visit_id(item.id);
444 walk_opt_name(visitor, item.span, opt_name)
446 ItemUse(ref path, _) => {
447 visitor.visit_id(item.id);
448 visitor.visit_path(path, item.id);
450 ItemStatic(ref typ, _, body) |
451 ItemConst(ref typ, body) => {
452 visitor.visit_id(item.id);
453 visitor.visit_ty(typ);
454 visitor.visit_nested_body(body);
456 ItemFn(ref declaration, unsafety, constness, abi, ref generics, body_id) => {
457 visitor.visit_fn(FnKind::ItemFn(item.name,
469 ItemMod(ref module) => {
470 // visit_mod() takes care of visiting the Item's NodeId
471 visitor.visit_mod(module, item.span, item.id)
473 ItemForeignMod(ref foreign_module) => {
474 visitor.visit_id(item.id);
475 walk_list!(visitor, visit_foreign_item, &foreign_module.items);
477 ItemTy(ref typ, ref type_parameters) => {
478 visitor.visit_id(item.id);
479 visitor.visit_ty(typ);
480 visitor.visit_generics(type_parameters)
482 ItemEnum(ref enum_definition, ref type_parameters) => {
483 visitor.visit_generics(type_parameters);
484 // visit_enum_def() takes care of visiting the Item's NodeId
485 visitor.visit_enum_def(enum_definition, type_parameters, item.id, item.span)
487 ItemDefaultImpl(_, ref trait_ref) => {
488 visitor.visit_id(item.id);
489 visitor.visit_trait_ref(trait_ref)
491 ItemImpl(.., ref type_parameters, ref opt_trait_reference, ref typ, ref impl_item_refs) => {
492 visitor.visit_id(item.id);
493 visitor.visit_generics(type_parameters);
494 walk_list!(visitor, visit_trait_ref, opt_trait_reference);
495 visitor.visit_ty(typ);
496 walk_list!(visitor, visit_impl_item_ref, impl_item_refs);
498 ItemStruct(ref struct_definition, ref generics) |
499 ItemUnion(ref struct_definition, ref generics) => {
500 visitor.visit_generics(generics);
501 visitor.visit_id(item.id);
502 visitor.visit_variant_data(struct_definition, item.name, generics, item.id, item.span);
504 ItemTrait(_, ref generics, ref bounds, ref trait_item_refs) => {
505 visitor.visit_id(item.id);
506 visitor.visit_generics(generics);
507 walk_list!(visitor, visit_ty_param_bound, bounds);
508 walk_list!(visitor, visit_trait_item_ref, trait_item_refs);
511 walk_list!(visitor, visit_attribute, &item.attrs);
514 pub fn walk_enum_def<'v, V: Visitor<'v>>(visitor: &mut V,
515 enum_definition: &'v EnumDef,
516 generics: &'v Generics,
518 visitor.visit_id(item_id);
521 &enum_definition.variants,
526 pub fn walk_variant<'v, V: Visitor<'v>>(visitor: &mut V,
527 variant: &'v Variant,
528 generics: &'v Generics,
529 parent_item_id: NodeId) {
530 visitor.visit_name(variant.span, variant.node.name);
531 visitor.visit_variant_data(&variant.node.data,
536 walk_list!(visitor, visit_nested_body, variant.node.disr_expr);
537 walk_list!(visitor, visit_attribute, &variant.node.attrs);
540 pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty) {
541 visitor.visit_id(typ.id);
547 TyPtr(ref mutable_type) => {
548 visitor.visit_ty(&mutable_type.ty)
550 TyRptr(ref opt_lifetime, ref mutable_type) => {
551 walk_list!(visitor, visit_lifetime, opt_lifetime);
552 visitor.visit_ty(&mutable_type.ty)
555 TyTup(ref tuple_element_types) => {
556 walk_list!(visitor, visit_ty, tuple_element_types);
558 TyBareFn(ref function_declaration) => {
559 visitor.visit_fn_decl(&function_declaration.decl);
560 walk_list!(visitor, visit_lifetime_def, &function_declaration.lifetimes);
562 TyPath(ref qpath) => {
563 visitor.visit_qpath(qpath, typ.id, typ.span);
565 TyArray(ref ty, length) => {
566 visitor.visit_ty(ty);
567 visitor.visit_nested_body(length)
569 TyTraitObject(ref bounds) => {
570 walk_list!(visitor, visit_ty_param_bound, bounds);
572 TyImplTrait(ref bounds) => {
573 walk_list!(visitor, visit_ty_param_bound, bounds);
575 TyTypeof(expression) => {
576 visitor.visit_nested_body(expression)
582 pub fn walk_qpath<'v, V: Visitor<'v>>(visitor: &mut V, qpath: &'v QPath, id: NodeId, span: Span) {
584 QPath::Resolved(ref maybe_qself, ref path) => {
585 if let Some(ref qself) = *maybe_qself {
586 visitor.visit_ty(qself);
588 visitor.visit_path(path, id)
590 QPath::TypeRelative(ref qself, ref segment) => {
591 visitor.visit_ty(qself);
592 visitor.visit_path_segment(span, segment);
597 pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path) {
598 visitor.visit_def_mention(path.def);
599 for segment in &path.segments {
600 visitor.visit_path_segment(path.span, segment);
604 pub fn walk_path_segment<'v, V: Visitor<'v>>(visitor: &mut V,
606 segment: &'v PathSegment) {
607 visitor.visit_name(path_span, segment.name);
608 visitor.visit_path_parameters(path_span, &segment.parameters);
611 pub fn walk_path_parameters<'v, V: Visitor<'v>>(visitor: &mut V,
613 path_parameters: &'v PathParameters) {
614 match *path_parameters {
615 AngleBracketedParameters(ref data) => {
616 walk_list!(visitor, visit_ty, &data.types);
617 walk_list!(visitor, visit_lifetime, &data.lifetimes);
618 walk_list!(visitor, visit_assoc_type_binding, &data.bindings);
620 ParenthesizedParameters(ref data) => {
621 walk_list!(visitor, visit_ty, &data.inputs);
622 walk_list!(visitor, visit_ty, &data.output);
627 pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(visitor: &mut V,
628 type_binding: &'v TypeBinding) {
629 visitor.visit_id(type_binding.id);
630 visitor.visit_name(type_binding.span, type_binding.name);
631 visitor.visit_ty(&type_binding.ty);
634 pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat) {
635 visitor.visit_id(pattern.id);
637 PatKind::TupleStruct(ref qpath, ref children, _) => {
638 visitor.visit_qpath(qpath, pattern.id, pattern.span);
639 walk_list!(visitor, visit_pat, children);
641 PatKind::Path(ref qpath) => {
642 visitor.visit_qpath(qpath, pattern.id, pattern.span);
644 PatKind::Struct(ref qpath, ref fields, _) => {
645 visitor.visit_qpath(qpath, pattern.id, pattern.span);
646 for field in fields {
647 visitor.visit_name(field.span, field.node.name);
648 visitor.visit_pat(&field.node.pat)
651 PatKind::Tuple(ref tuple_elements, _) => {
652 walk_list!(visitor, visit_pat, tuple_elements);
654 PatKind::Box(ref subpattern) |
655 PatKind::Ref(ref subpattern, _) => {
656 visitor.visit_pat(subpattern)
658 PatKind::Binding(_, def_id, ref pth1, ref optional_subpattern) => {
659 visitor.visit_def_mention(Def::Local(def_id));
660 visitor.visit_name(pth1.span, pth1.node);
661 walk_list!(visitor, visit_pat, optional_subpattern);
663 PatKind::Lit(ref expression) => visitor.visit_expr(expression),
664 PatKind::Range(ref lower_bound, ref upper_bound) => {
665 visitor.visit_expr(lower_bound);
666 visitor.visit_expr(upper_bound)
669 PatKind::Slice(ref prepatterns, ref slice_pattern, ref postpatterns) => {
670 walk_list!(visitor, visit_pat, prepatterns);
671 walk_list!(visitor, visit_pat, slice_pattern);
672 walk_list!(visitor, visit_pat, postpatterns);
677 pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V, foreign_item: &'v ForeignItem) {
678 visitor.visit_id(foreign_item.id);
679 visitor.visit_vis(&foreign_item.vis);
680 visitor.visit_name(foreign_item.span, foreign_item.name);
682 match foreign_item.node {
683 ForeignItemFn(ref function_declaration, ref names, ref generics) => {
684 visitor.visit_generics(generics);
685 visitor.visit_fn_decl(function_declaration);
687 visitor.visit_name(name.span, name.node);
690 ForeignItemStatic(ref typ, _) => visitor.visit_ty(typ),
693 walk_list!(visitor, visit_attribute, &foreign_item.attrs);
696 pub fn walk_ty_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v TyParamBound) {
698 TraitTyParamBound(ref typ, ref modifier) => {
699 visitor.visit_poly_trait_ref(typ, modifier);
701 RegionTyParamBound(ref lifetime) => {
702 visitor.visit_lifetime(lifetime);
707 pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics) {
708 for param in &generics.ty_params {
709 visitor.visit_id(param.id);
710 visitor.visit_name(param.span, param.name);
711 walk_list!(visitor, visit_ty_param_bound, ¶m.bounds);
712 walk_list!(visitor, visit_ty, ¶m.default);
714 walk_list!(visitor, visit_lifetime_def, &generics.lifetimes);
715 visitor.visit_id(generics.where_clause.id);
716 walk_list!(visitor, visit_where_predicate, &generics.where_clause.predicates);
719 pub fn walk_where_predicate<'v, V: Visitor<'v>>(
721 predicate: &'v WherePredicate)
724 &WherePredicate::BoundPredicate(WhereBoundPredicate{ref bounded_ty,
728 visitor.visit_ty(bounded_ty);
729 walk_list!(visitor, visit_ty_param_bound, bounds);
730 walk_list!(visitor, visit_lifetime_def, bound_lifetimes);
732 &WherePredicate::RegionPredicate(WhereRegionPredicate{ref lifetime,
735 visitor.visit_lifetime(lifetime);
736 walk_list!(visitor, visit_lifetime, bounds);
738 &WherePredicate::EqPredicate(WhereEqPredicate{id,
742 visitor.visit_id(id);
743 visitor.visit_ty(lhs_ty);
744 visitor.visit_ty(rhs_ty);
749 pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FunctionRetTy) {
750 if let Return(ref output_ty) = *ret_ty {
751 visitor.visit_ty(output_ty)
755 pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl) {
756 for ty in &function_declaration.inputs {
759 walk_fn_ret_ty(visitor, &function_declaration.output)
762 pub fn walk_fn_kind<'v, V: Visitor<'v>>(visitor: &mut V, function_kind: FnKind<'v>) {
763 match function_kind {
764 FnKind::ItemFn(_, generics, ..) => {
765 visitor.visit_generics(generics);
767 FnKind::Method(_, sig, ..) => {
768 visitor.visit_generics(&sig.generics);
770 FnKind::Closure(_) => {}
774 pub fn walk_fn<'v, V: Visitor<'v>>(visitor: &mut V,
775 function_kind: FnKind<'v>,
776 function_declaration: &'v FnDecl,
780 visitor.visit_id(id);
781 visitor.visit_fn_decl(function_declaration);
782 walk_fn_kind(visitor, function_kind);
783 visitor.visit_nested_body(body_id)
786 pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem) {
787 visitor.visit_name(trait_item.span, trait_item.name);
788 walk_list!(visitor, visit_attribute, &trait_item.attrs);
789 match trait_item.node {
790 TraitItemKind::Const(ref ty, default) => {
791 visitor.visit_id(trait_item.id);
792 visitor.visit_ty(ty);
793 walk_list!(visitor, visit_nested_body, default);
795 TraitItemKind::Method(ref sig, TraitMethod::Required(ref names)) => {
796 visitor.visit_id(trait_item.id);
797 visitor.visit_generics(&sig.generics);
798 visitor.visit_fn_decl(&sig.decl);
800 visitor.visit_name(name.span, name.node);
803 TraitItemKind::Method(ref sig, TraitMethod::Provided(body_id)) => {
804 visitor.visit_fn(FnKind::Method(trait_item.name,
813 TraitItemKind::Type(ref bounds, ref default) => {
814 visitor.visit_id(trait_item.id);
815 walk_list!(visitor, visit_ty_param_bound, bounds);
816 walk_list!(visitor, visit_ty, default);
821 pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref: &'v TraitItemRef) {
822 // NB: Deliberately force a compilation error if/when new fields are added.
823 let TraitItemRef { id, name, ref kind, span, ref defaultness } = *trait_item_ref;
824 visitor.visit_nested_trait_item(id);
825 visitor.visit_name(span, name);
826 visitor.visit_associated_item_kind(kind);
827 visitor.visit_defaultness(defaultness);
830 pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem) {
831 // NB: Deliberately force a compilation error if/when new fields are added.
832 let ImplItem { id: _, name, ref vis, ref defaultness, ref attrs, ref node, span } = *impl_item;
834 visitor.visit_name(span, name);
835 visitor.visit_vis(vis);
836 visitor.visit_defaultness(defaultness);
837 walk_list!(visitor, visit_attribute, attrs);
839 ImplItemKind::Const(ref ty, body) => {
840 visitor.visit_id(impl_item.id);
841 visitor.visit_ty(ty);
842 visitor.visit_nested_body(body);
844 ImplItemKind::Method(ref sig, body_id) => {
845 visitor.visit_fn(FnKind::Method(impl_item.name,
847 Some(&impl_item.vis),
854 ImplItemKind::Type(ref ty) => {
855 visitor.visit_id(impl_item.id);
856 visitor.visit_ty(ty);
861 pub fn walk_impl_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, impl_item_ref: &'v ImplItemRef) {
862 // NB: Deliberately force a compilation error if/when new fields are added.
863 let ImplItemRef { id, name, ref kind, span, ref vis, ref defaultness } = *impl_item_ref;
864 visitor.visit_nested_impl_item(id);
865 visitor.visit_name(span, name);
866 visitor.visit_associated_item_kind(kind);
867 visitor.visit_vis(vis);
868 visitor.visit_defaultness(defaultness);
872 pub fn walk_struct_def<'v, V: Visitor<'v>>(visitor: &mut V, struct_definition: &'v VariantData) {
873 visitor.visit_id(struct_definition.id());
874 walk_list!(visitor, visit_struct_field, struct_definition.fields());
877 pub fn walk_struct_field<'v, V: Visitor<'v>>(visitor: &mut V, struct_field: &'v StructField) {
878 visitor.visit_id(struct_field.id);
879 visitor.visit_vis(&struct_field.vis);
880 visitor.visit_name(struct_field.span, struct_field.name);
881 visitor.visit_ty(&struct_field.ty);
882 walk_list!(visitor, visit_attribute, &struct_field.attrs);
885 pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block) {
886 visitor.visit_id(block.id);
887 walk_list!(visitor, visit_stmt, &block.stmts);
888 walk_list!(visitor, visit_expr, &block.expr);
891 pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt) {
892 match statement.node {
893 StmtDecl(ref declaration, id) => {
894 visitor.visit_id(id);
895 visitor.visit_decl(declaration)
897 StmtExpr(ref expression, id) |
898 StmtSemi(ref expression, id) => {
899 visitor.visit_id(id);
900 visitor.visit_expr(expression)
905 pub fn walk_decl<'v, V: Visitor<'v>>(visitor: &mut V, declaration: &'v Decl) {
906 match declaration.node {
907 DeclLocal(ref local) => visitor.visit_local(local),
908 DeclItem(item) => visitor.visit_nested_item(item),
912 pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
913 visitor.visit_id(expression.id);
914 match expression.node {
915 ExprBox(ref subexpression) => {
916 visitor.visit_expr(subexpression)
918 ExprArray(ref subexpressions) => {
919 walk_list!(visitor, visit_expr, subexpressions);
921 ExprRepeat(ref element, count) => {
922 visitor.visit_expr(element);
923 visitor.visit_nested_body(count)
925 ExprStruct(ref qpath, ref fields, ref optional_base) => {
926 visitor.visit_qpath(qpath, expression.id, expression.span);
927 for field in fields {
928 visitor.visit_name(field.name.span, field.name.node);
929 visitor.visit_expr(&field.expr)
931 walk_list!(visitor, visit_expr, optional_base);
933 ExprTup(ref subexpressions) => {
934 walk_list!(visitor, visit_expr, subexpressions);
936 ExprCall(ref callee_expression, ref arguments) => {
937 walk_list!(visitor, visit_expr, arguments);
938 visitor.visit_expr(callee_expression)
940 ExprMethodCall(ref name, ref types, ref arguments) => {
941 visitor.visit_name(name.span, name.node);
942 walk_list!(visitor, visit_expr, arguments);
943 walk_list!(visitor, visit_ty, types);
945 ExprBinary(_, ref left_expression, ref right_expression) => {
946 visitor.visit_expr(left_expression);
947 visitor.visit_expr(right_expression)
949 ExprAddrOf(_, ref subexpression) | ExprUnary(_, ref subexpression) => {
950 visitor.visit_expr(subexpression)
953 ExprCast(ref subexpression, ref typ) | ExprType(ref subexpression, ref typ) => {
954 visitor.visit_expr(subexpression);
955 visitor.visit_ty(typ)
957 ExprIf(ref head_expression, ref if_block, ref optional_else) => {
958 visitor.visit_expr(head_expression);
959 visitor.visit_block(if_block);
960 walk_list!(visitor, visit_expr, optional_else);
962 ExprWhile(ref subexpression, ref block, ref opt_sp_name) => {
963 visitor.visit_expr(subexpression);
964 visitor.visit_block(block);
965 walk_opt_sp_name(visitor, opt_sp_name);
967 ExprLoop(ref block, ref opt_sp_name, _) => {
968 visitor.visit_block(block);
969 walk_opt_sp_name(visitor, opt_sp_name);
971 ExprMatch(ref subexpression, ref arms, _) => {
972 visitor.visit_expr(subexpression);
973 walk_list!(visitor, visit_arm, arms);
975 ExprClosure(_, ref function_declaration, body, _fn_decl_span) => {
976 visitor.visit_fn(FnKind::Closure(&expression.attrs),
977 function_declaration,
982 ExprBlock(ref block) => visitor.visit_block(block),
983 ExprAssign(ref left_hand_expression, ref right_hand_expression) => {
984 visitor.visit_expr(right_hand_expression);
985 visitor.visit_expr(left_hand_expression)
987 ExprAssignOp(_, ref left_expression, ref right_expression) => {
988 visitor.visit_expr(right_expression);
989 visitor.visit_expr(left_expression)
991 ExprField(ref subexpression, ref name) => {
992 visitor.visit_expr(subexpression);
993 visitor.visit_name(name.span, name.node);
995 ExprTupField(ref subexpression, _) => {
996 visitor.visit_expr(subexpression);
998 ExprIndex(ref main_expression, ref index_expression) => {
999 visitor.visit_expr(main_expression);
1000 visitor.visit_expr(index_expression)
1002 ExprPath(ref qpath) => {
1003 visitor.visit_qpath(qpath, expression.id, expression.span);
1005 ExprBreak(None, ref opt_expr) => {
1006 walk_list!(visitor, visit_expr, opt_expr);
1008 ExprBreak(Some(label), ref opt_expr) => {
1009 visitor.visit_def_mention(Def::Label(label.loop_id));
1010 visitor.visit_name(label.span, label.name);
1011 walk_list!(visitor, visit_expr, opt_expr);
1013 ExprAgain(None) => {}
1014 ExprAgain(Some(label)) => {
1015 visitor.visit_def_mention(Def::Label(label.loop_id));
1016 visitor.visit_name(label.span, label.name);
1018 ExprRet(ref optional_expression) => {
1019 walk_list!(visitor, visit_expr, optional_expression);
1021 ExprInlineAsm(_, ref outputs, ref inputs) => {
1022 for output in outputs {
1023 visitor.visit_expr(output)
1025 for input in inputs {
1026 visitor.visit_expr(input)
1032 pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm) {
1033 walk_list!(visitor, visit_pat, &arm.pats);
1034 walk_list!(visitor, visit_expr, &arm.guard);
1035 visitor.visit_expr(&arm.body);
1036 walk_list!(visitor, visit_attribute, &arm.attrs);
1039 pub fn walk_vis<'v, V: Visitor<'v>>(visitor: &mut V, vis: &'v Visibility) {
1040 if let Visibility::Restricted { ref path, id } = *vis {
1041 visitor.visit_id(id);
1042 visitor.visit_path(path, id)
1046 pub fn walk_associated_item_kind<'v, V: Visitor<'v>>(_: &mut V, _: &'v AssociatedItemKind) {
1047 // No visitable content here: this fn exists so you can call it if
1048 // the right thing to do, should content be added in the future,
1049 // would be to walk it.
1052 pub fn walk_defaultness<'v, V: Visitor<'v>>(_: &mut V, _: &'v Defaultness) {
1053 // No visitable content here: this fn exists so you can call it if
1054 // the right thing to do, should content be added in the future,
1055 // would be to walk it.
1058 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug, PartialEq, Eq)]
1059 pub struct IdRange {
1065 pub fn max() -> IdRange {
1067 min: NodeId::from_u32(u32::MAX),
1068 max: NodeId::from_u32(u32::MIN),
1072 pub fn empty(&self) -> bool {
1073 self.min >= self.max
1076 pub fn contains(&self, id: NodeId) -> bool {
1077 id >= self.min && id < self.max
1080 pub fn add(&mut self, id: NodeId) {
1081 self.min = cmp::min(self.min, id);
1082 self.max = cmp::max(self.max, NodeId::from_u32(id.as_u32() + 1));
1088 pub struct IdRangeComputingVisitor<'a, 'ast: 'a> {
1090 map: &'a map::Map<'ast>,
1093 impl<'a, 'ast> IdRangeComputingVisitor<'a, 'ast> {
1094 pub fn new(map: &'a map::Map<'ast>) -> IdRangeComputingVisitor<'a, 'ast> {
1095 IdRangeComputingVisitor { result: IdRange::max(), map: map }
1098 pub fn result(&self) -> IdRange {
1103 impl<'a, 'ast> Visitor<'ast> for IdRangeComputingVisitor<'a, 'ast> {
1104 fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'ast> {
1105 NestedVisitorMap::OnlyBodies(&self.map)
1108 fn visit_id(&mut self, id: NodeId) {
1109 self.result.add(id);