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;
42 use hir::map::{self, Map};
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 `visit_all_item_likes()` 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 /// Invokes the suitable visitor method for the given `Node`
144 /// extracted from the hir map.
145 fn visit_hir_map_node(&mut self, node: map::Node<'v>) {
147 map::NodeItem(a) => self.visit_item(a),
148 map::NodeForeignItem(a) => self.visit_foreign_item(a),
149 map::NodeTraitItem(a) => self.visit_trait_item(a),
150 map::NodeImplItem(a) => self.visit_impl_item(a),
151 map::NodeExpr(a) => self.visit_expr(a),
152 map::NodeStmt(a) => self.visit_stmt(a),
153 map::NodeTy(a) => self.visit_ty(a),
154 map::NodePat(a) => self.visit_pat(a),
155 map::NodeBlock(a) => self.visit_block(a),
156 _ => bug!("Visitor::visit_hir_map_node() not yet impl for node `{:?}`", node)
160 ///////////////////////////////////////////////////////////////////////////
163 /// The default versions of the `visit_nested_XXX` routines invoke
164 /// this method to get a map to use. By selecting an enum variant,
165 /// you control which kinds of nested HIR are visited; see
166 /// `NestedVisitorMap` for details. By "nested HIR", we are
167 /// referring to bits of HIR that are not directly embedded within
168 /// one another but rather indirectly, through a table in the
169 /// crate. This is done to control dependencies during incremental
170 /// compilation: the non-inline bits of HIR can be tracked and
171 /// hashed separately.
173 /// **If for some reason you want the nested behavior, but don't
174 /// have a `Map` at your disposal:** then you should override the
175 /// `visit_nested_XXX` methods, and override this method to
176 /// `panic!()`. This way, if a new `visit_nested_XXX` variant is
177 /// added in the future, we will see the panic in your code and
178 /// fix it appropriately.
179 fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'v>;
181 /// Invoked when a nested item is encountered. By default does
182 /// nothing unless you override `nested_visit_map` to return
183 /// `Some(_)`, in which case it will walk the item. **You probably
184 /// don't want to override this method** -- instead, override
185 /// `nested_visit_map` or use the "shallow" or "deep" visit
186 /// patterns described on `itemlikevisit::ItemLikeVisitor`. The only
187 /// reason to override this method is if you want a nested pattern
188 /// but cannot supply a `Map`; see `nested_visit_map` for advice.
189 #[allow(unused_variables)]
190 fn visit_nested_item(&mut self, id: ItemId) {
191 let opt_item = self.nested_visit_map().inter().map(|map| map.expect_item(id.id));
192 if let Some(item) = opt_item {
193 self.visit_item(item);
197 /// Like `visit_nested_item()`, but for trait items. See
198 /// `visit_nested_item()` for advice on when to override this
200 #[allow(unused_variables)]
201 fn visit_nested_trait_item(&mut self, id: TraitItemId) {
202 let opt_item = self.nested_visit_map().inter().map(|map| map.trait_item(id));
203 if let Some(item) = opt_item {
204 self.visit_trait_item(item);
208 /// Like `visit_nested_item()`, but for impl items. See
209 /// `visit_nested_item()` for advice on when to override this
211 #[allow(unused_variables)]
212 fn visit_nested_impl_item(&mut self, id: ImplItemId) {
213 let opt_item = self.nested_visit_map().inter().map(|map| map.impl_item(id));
214 if let Some(item) = opt_item {
215 self.visit_impl_item(item);
219 /// Invoked to visit the body of a function, method or closure. Like
220 /// visit_nested_item, does nothing by default unless you override
221 /// `nested_visit_map` to return `Some(_)`, in which case it will walk the
223 fn visit_nested_body(&mut self, id: BodyId) {
224 let opt_body = self.nested_visit_map().intra().map(|map| map.body(id));
225 if let Some(body) = opt_body {
226 self.visit_body(body);
230 /// Visit the top-level item and (optionally) nested items / impl items. See
231 /// `visit_nested_item` for details.
232 fn visit_item(&mut self, i: &'v Item) {
236 fn visit_body(&mut self, b: &'v Body) {
240 /// When invoking `visit_all_item_likes()`, you need to supply an
241 /// item-like visitor. This method converts a "intra-visit"
242 /// visitor into an item-like visitor that walks the entire tree.
243 /// If you use this, you probably don't want to process the
244 /// contents of nested item-like things, since the outer loop will
245 /// visit them as well.
246 fn as_deep_visitor<'s>(&'s mut self) -> DeepVisitor<'s, Self> {
247 DeepVisitor::new(self)
250 ///////////////////////////////////////////////////////////////////////////
252 fn visit_id(&mut self, _node_id: NodeId) {
255 fn visit_def_mention(&mut self, _def: Def) {
258 fn visit_name(&mut self, _span: Span, _name: Name) {
261 fn visit_mod(&mut self, m: &'v Mod, _s: Span, n: NodeId) {
264 fn visit_foreign_item(&mut self, i: &'v ForeignItem) {
265 walk_foreign_item(self, i)
267 fn visit_local(&mut self, l: &'v Local) {
270 fn visit_block(&mut self, b: &'v Block) {
273 fn visit_stmt(&mut self, s: &'v Stmt) {
276 fn visit_arm(&mut self, a: &'v Arm) {
279 fn visit_pat(&mut self, p: &'v Pat) {
282 fn visit_decl(&mut self, d: &'v Decl) {
285 fn visit_expr(&mut self, ex: &'v Expr) {
288 fn visit_ty(&mut self, t: &'v Ty) {
291 fn visit_generics(&mut self, g: &'v Generics) {
292 walk_generics(self, g)
294 fn visit_where_predicate(&mut self, predicate: &'v WherePredicate) {
295 walk_where_predicate(self, predicate)
297 fn visit_fn_decl(&mut self, fd: &'v FnDecl) {
298 walk_fn_decl(self, fd)
300 fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl, b: BodyId, s: Span, id: NodeId) {
301 walk_fn(self, fk, fd, b, s, id)
303 fn visit_trait_item(&mut self, ti: &'v TraitItem) {
304 walk_trait_item(self, ti)
306 fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) {
307 walk_trait_item_ref(self, ii)
309 fn visit_impl_item(&mut self, ii: &'v ImplItem) {
310 walk_impl_item(self, ii)
312 fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef) {
313 walk_impl_item_ref(self, ii)
315 fn visit_trait_ref(&mut self, t: &'v TraitRef) {
316 walk_trait_ref(self, t)
318 fn visit_ty_param_bound(&mut self, bounds: &'v TyParamBound) {
319 walk_ty_param_bound(self, bounds)
321 fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef, m: TraitBoundModifier) {
322 walk_poly_trait_ref(self, t, m)
324 fn visit_variant_data(&mut self,
330 walk_struct_def(self, s)
332 fn visit_struct_field(&mut self, s: &'v StructField) {
333 walk_struct_field(self, s)
335 fn visit_enum_def(&mut self,
336 enum_definition: &'v EnumDef,
337 generics: &'v Generics,
340 walk_enum_def(self, enum_definition, generics, item_id)
342 fn visit_variant(&mut self, v: &'v Variant, g: &'v Generics, item_id: NodeId) {
343 walk_variant(self, v, g, item_id)
345 fn visit_lifetime(&mut self, lifetime: &'v Lifetime) {
346 walk_lifetime(self, lifetime)
348 fn visit_lifetime_def(&mut self, lifetime: &'v LifetimeDef) {
349 walk_lifetime_def(self, lifetime)
351 fn visit_qpath(&mut self, qpath: &'v QPath, id: NodeId, span: Span) {
352 walk_qpath(self, qpath, id, span)
354 fn visit_path(&mut self, path: &'v Path, _id: NodeId) {
355 walk_path(self, path)
357 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment) {
358 walk_path_segment(self, path_span, path_segment)
360 fn visit_path_parameters(&mut self, path_span: Span, path_parameters: &'v PathParameters) {
361 walk_path_parameters(self, path_span, path_parameters)
363 fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding) {
364 walk_assoc_type_binding(self, type_binding)
366 fn visit_attribute(&mut self, _attr: &'v Attribute) {
368 fn visit_macro_def(&mut self, macro_def: &'v MacroDef) {
369 walk_macro_def(self, macro_def)
371 fn visit_vis(&mut self, vis: &'v Visibility) {
374 fn visit_associated_item_kind(&mut self, kind: &'v AssociatedItemKind) {
375 walk_associated_item_kind(self, kind);
377 fn visit_defaultness(&mut self, defaultness: &'v Defaultness) {
378 walk_defaultness(self, defaultness);
382 pub fn walk_opt_name<'v, V: Visitor<'v>>(visitor: &mut V, span: Span, opt_name: Option<Name>) {
383 if let Some(name) = opt_name {
384 visitor.visit_name(span, name);
388 pub fn walk_opt_sp_name<'v, V: Visitor<'v>>(visitor: &mut V, opt_sp_name: &Option<Spanned<Name>>) {
389 if let Some(ref sp_name) = *opt_sp_name {
390 visitor.visit_name(sp_name.span, sp_name.node);
394 /// Walks the contents of a crate. See also `Crate::visit_all_items`.
395 pub fn walk_crate<'v, V: Visitor<'v>>(visitor: &mut V, krate: &'v Crate) {
396 visitor.visit_mod(&krate.module, krate.span, CRATE_NODE_ID);
397 walk_list!(visitor, visit_attribute, &krate.attrs);
398 walk_list!(visitor, visit_macro_def, &krate.exported_macros);
401 pub fn walk_macro_def<'v, V: Visitor<'v>>(visitor: &mut V, macro_def: &'v MacroDef) {
402 visitor.visit_id(macro_def.id);
403 visitor.visit_name(macro_def.span, macro_def.name);
404 walk_list!(visitor, visit_attribute, ¯o_def.attrs);
407 pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod, mod_node_id: NodeId) {
408 visitor.visit_id(mod_node_id);
409 for &item_id in &module.item_ids {
410 visitor.visit_nested_item(item_id);
414 pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body) {
415 for argument in &body.arguments {
416 visitor.visit_id(argument.id);
417 visitor.visit_pat(&argument.pat);
419 visitor.visit_expr(&body.value);
422 pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local) {
423 visitor.visit_id(local.id);
424 visitor.visit_pat(&local.pat);
425 walk_list!(visitor, visit_ty, &local.ty);
426 walk_list!(visitor, visit_expr, &local.init);
429 pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) {
430 visitor.visit_id(lifetime.id);
431 visitor.visit_name(lifetime.span, lifetime.name);
434 pub fn walk_lifetime_def<'v, V: Visitor<'v>>(visitor: &mut V, lifetime_def: &'v LifetimeDef) {
435 visitor.visit_lifetime(&lifetime_def.lifetime);
436 walk_list!(visitor, visit_lifetime, &lifetime_def.bounds);
439 pub fn walk_poly_trait_ref<'v, V>(visitor: &mut V,
440 trait_ref: &'v PolyTraitRef,
441 _modifier: TraitBoundModifier)
444 walk_list!(visitor, visit_lifetime_def, &trait_ref.bound_lifetimes);
445 visitor.visit_trait_ref(&trait_ref.trait_ref);
448 pub fn walk_trait_ref<'v, V>(visitor: &mut V, trait_ref: &'v TraitRef)
451 visitor.visit_id(trait_ref.ref_id);
452 visitor.visit_path(&trait_ref.path, trait_ref.ref_id)
455 pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {
456 visitor.visit_vis(&item.vis);
457 visitor.visit_name(item.span, item.name);
459 ItemExternCrate(opt_name) => {
460 visitor.visit_id(item.id);
461 walk_opt_name(visitor, item.span, opt_name)
463 ItemUse(ref path, _) => {
464 visitor.visit_id(item.id);
465 visitor.visit_path(path, item.id);
467 ItemStatic(ref typ, _, body) |
468 ItemConst(ref typ, body) => {
469 visitor.visit_id(item.id);
470 visitor.visit_ty(typ);
471 visitor.visit_nested_body(body);
473 ItemFn(ref declaration, unsafety, constness, abi, ref generics, body_id) => {
474 visitor.visit_fn(FnKind::ItemFn(item.name,
486 ItemMod(ref module) => {
487 // visit_mod() takes care of visiting the Item's NodeId
488 visitor.visit_mod(module, item.span, item.id)
490 ItemForeignMod(ref foreign_module) => {
491 visitor.visit_id(item.id);
492 walk_list!(visitor, visit_foreign_item, &foreign_module.items);
494 ItemGlobalAsm(_) => {
495 visitor.visit_id(item.id);
497 ItemTy(ref typ, ref type_parameters) => {
498 visitor.visit_id(item.id);
499 visitor.visit_ty(typ);
500 visitor.visit_generics(type_parameters)
502 ItemEnum(ref enum_definition, ref type_parameters) => {
503 visitor.visit_generics(type_parameters);
504 // visit_enum_def() takes care of visiting the Item's NodeId
505 visitor.visit_enum_def(enum_definition, type_parameters, item.id, item.span)
507 ItemDefaultImpl(_, ref trait_ref) => {
508 visitor.visit_id(item.id);
509 visitor.visit_trait_ref(trait_ref)
511 ItemImpl(.., ref type_parameters, ref opt_trait_reference, ref typ, ref impl_item_refs) => {
512 visitor.visit_id(item.id);
513 visitor.visit_generics(type_parameters);
514 walk_list!(visitor, visit_trait_ref, opt_trait_reference);
515 visitor.visit_ty(typ);
516 walk_list!(visitor, visit_impl_item_ref, impl_item_refs);
518 ItemStruct(ref struct_definition, ref generics) |
519 ItemUnion(ref struct_definition, ref generics) => {
520 visitor.visit_generics(generics);
521 visitor.visit_id(item.id);
522 visitor.visit_variant_data(struct_definition, item.name, generics, item.id, item.span);
524 ItemTrait(_, ref generics, ref bounds, ref trait_item_refs) => {
525 visitor.visit_id(item.id);
526 visitor.visit_generics(generics);
527 walk_list!(visitor, visit_ty_param_bound, bounds);
528 walk_list!(visitor, visit_trait_item_ref, trait_item_refs);
531 walk_list!(visitor, visit_attribute, &item.attrs);
534 pub fn walk_enum_def<'v, V: Visitor<'v>>(visitor: &mut V,
535 enum_definition: &'v EnumDef,
536 generics: &'v Generics,
538 visitor.visit_id(item_id);
541 &enum_definition.variants,
546 pub fn walk_variant<'v, V: Visitor<'v>>(visitor: &mut V,
547 variant: &'v Variant,
548 generics: &'v Generics,
549 parent_item_id: NodeId) {
550 visitor.visit_name(variant.span, variant.node.name);
551 visitor.visit_variant_data(&variant.node.data,
556 walk_list!(visitor, visit_nested_body, variant.node.disr_expr);
557 walk_list!(visitor, visit_attribute, &variant.node.attrs);
560 pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty) {
561 visitor.visit_id(typ.id);
567 TyPtr(ref mutable_type) => {
568 visitor.visit_ty(&mutable_type.ty)
570 TyRptr(ref lifetime, ref mutable_type) => {
571 visitor.visit_lifetime(lifetime);
572 visitor.visit_ty(&mutable_type.ty)
575 TyTup(ref tuple_element_types) => {
576 walk_list!(visitor, visit_ty, tuple_element_types);
578 TyBareFn(ref function_declaration) => {
579 visitor.visit_fn_decl(&function_declaration.decl);
580 walk_list!(visitor, visit_lifetime_def, &function_declaration.lifetimes);
582 TyPath(ref qpath) => {
583 visitor.visit_qpath(qpath, typ.id, typ.span);
585 TyArray(ref ty, length) => {
586 visitor.visit_ty(ty);
587 visitor.visit_nested_body(length)
589 TyTraitObject(ref bounds, ref lifetime) => {
590 for bound in bounds {
591 visitor.visit_poly_trait_ref(bound, TraitBoundModifier::None);
593 visitor.visit_lifetime(lifetime);
595 TyImplTrait(ref bounds) => {
596 walk_list!(visitor, visit_ty_param_bound, bounds);
598 TyTypeof(expression) => {
599 visitor.visit_nested_body(expression)
601 TyInfer | TyErr => {}
605 pub fn walk_qpath<'v, V: Visitor<'v>>(visitor: &mut V, qpath: &'v QPath, id: NodeId, span: Span) {
607 QPath::Resolved(ref maybe_qself, ref path) => {
608 if let Some(ref qself) = *maybe_qself {
609 visitor.visit_ty(qself);
611 visitor.visit_path(path, id)
613 QPath::TypeRelative(ref qself, ref segment) => {
614 visitor.visit_ty(qself);
615 visitor.visit_path_segment(span, segment);
620 pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path) {
621 visitor.visit_def_mention(path.def);
622 for segment in &path.segments {
623 visitor.visit_path_segment(path.span, segment);
627 pub fn walk_path_segment<'v, V: Visitor<'v>>(visitor: &mut V,
629 segment: &'v PathSegment) {
630 visitor.visit_name(path_span, segment.name);
631 visitor.visit_path_parameters(path_span, &segment.parameters);
634 pub fn walk_path_parameters<'v, V: Visitor<'v>>(visitor: &mut V,
636 path_parameters: &'v PathParameters) {
637 match *path_parameters {
638 AngleBracketedParameters(ref data) => {
639 walk_list!(visitor, visit_ty, &data.types);
640 walk_list!(visitor, visit_lifetime, &data.lifetimes);
641 walk_list!(visitor, visit_assoc_type_binding, &data.bindings);
643 ParenthesizedParameters(ref data) => {
644 walk_list!(visitor, visit_ty, &data.inputs);
645 walk_list!(visitor, visit_ty, &data.output);
650 pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(visitor: &mut V,
651 type_binding: &'v TypeBinding) {
652 visitor.visit_id(type_binding.id);
653 visitor.visit_name(type_binding.span, type_binding.name);
654 visitor.visit_ty(&type_binding.ty);
657 pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat) {
658 visitor.visit_id(pattern.id);
660 PatKind::TupleStruct(ref qpath, ref children, _) => {
661 visitor.visit_qpath(qpath, pattern.id, pattern.span);
662 walk_list!(visitor, visit_pat, children);
664 PatKind::Path(ref qpath) => {
665 visitor.visit_qpath(qpath, pattern.id, pattern.span);
667 PatKind::Struct(ref qpath, ref fields, _) => {
668 visitor.visit_qpath(qpath, pattern.id, pattern.span);
669 for field in fields {
670 visitor.visit_name(field.span, field.node.name);
671 visitor.visit_pat(&field.node.pat)
674 PatKind::Tuple(ref tuple_elements, _) => {
675 walk_list!(visitor, visit_pat, tuple_elements);
677 PatKind::Box(ref subpattern) |
678 PatKind::Ref(ref subpattern, _) => {
679 visitor.visit_pat(subpattern)
681 PatKind::Binding(_, def_id, ref pth1, ref optional_subpattern) => {
682 visitor.visit_def_mention(Def::Local(def_id));
683 visitor.visit_name(pth1.span, pth1.node);
684 walk_list!(visitor, visit_pat, optional_subpattern);
686 PatKind::Lit(ref expression) => visitor.visit_expr(expression),
687 PatKind::Range(ref lower_bound, ref upper_bound, _) => {
688 visitor.visit_expr(lower_bound);
689 visitor.visit_expr(upper_bound)
692 PatKind::Slice(ref prepatterns, ref slice_pattern, ref postpatterns) => {
693 walk_list!(visitor, visit_pat, prepatterns);
694 walk_list!(visitor, visit_pat, slice_pattern);
695 walk_list!(visitor, visit_pat, postpatterns);
700 pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V, foreign_item: &'v ForeignItem) {
701 visitor.visit_id(foreign_item.id);
702 visitor.visit_vis(&foreign_item.vis);
703 visitor.visit_name(foreign_item.span, foreign_item.name);
705 match foreign_item.node {
706 ForeignItemFn(ref function_declaration, ref names, ref generics) => {
707 visitor.visit_generics(generics);
708 visitor.visit_fn_decl(function_declaration);
710 visitor.visit_name(name.span, name.node);
713 ForeignItemStatic(ref typ, _) => visitor.visit_ty(typ),
716 walk_list!(visitor, visit_attribute, &foreign_item.attrs);
719 pub fn walk_ty_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v TyParamBound) {
721 TraitTyParamBound(ref typ, modifier) => {
722 visitor.visit_poly_trait_ref(typ, modifier);
724 RegionTyParamBound(ref lifetime) => {
725 visitor.visit_lifetime(lifetime);
730 pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics) {
731 for param in &generics.ty_params {
732 visitor.visit_id(param.id);
733 visitor.visit_name(param.span, param.name);
734 walk_list!(visitor, visit_ty_param_bound, ¶m.bounds);
735 walk_list!(visitor, visit_ty, ¶m.default);
737 walk_list!(visitor, visit_lifetime_def, &generics.lifetimes);
738 visitor.visit_id(generics.where_clause.id);
739 walk_list!(visitor, visit_where_predicate, &generics.where_clause.predicates);
742 pub fn walk_where_predicate<'v, V: Visitor<'v>>(
744 predicate: &'v WherePredicate)
747 &WherePredicate::BoundPredicate(WhereBoundPredicate{ref bounded_ty,
751 visitor.visit_ty(bounded_ty);
752 walk_list!(visitor, visit_ty_param_bound, bounds);
753 walk_list!(visitor, visit_lifetime_def, bound_lifetimes);
755 &WherePredicate::RegionPredicate(WhereRegionPredicate{ref lifetime,
758 visitor.visit_lifetime(lifetime);
759 walk_list!(visitor, visit_lifetime, bounds);
761 &WherePredicate::EqPredicate(WhereEqPredicate{id,
765 visitor.visit_id(id);
766 visitor.visit_ty(lhs_ty);
767 visitor.visit_ty(rhs_ty);
772 pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FunctionRetTy) {
773 if let Return(ref output_ty) = *ret_ty {
774 visitor.visit_ty(output_ty)
778 pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl) {
779 for ty in &function_declaration.inputs {
782 walk_fn_ret_ty(visitor, &function_declaration.output)
785 pub fn walk_fn_kind<'v, V: Visitor<'v>>(visitor: &mut V, function_kind: FnKind<'v>) {
786 match function_kind {
787 FnKind::ItemFn(_, generics, ..) => {
788 visitor.visit_generics(generics);
790 FnKind::Method(_, sig, ..) => {
791 visitor.visit_generics(&sig.generics);
793 FnKind::Closure(_) => {}
797 pub fn walk_fn<'v, V: Visitor<'v>>(visitor: &mut V,
798 function_kind: FnKind<'v>,
799 function_declaration: &'v FnDecl,
803 visitor.visit_id(id);
804 visitor.visit_fn_decl(function_declaration);
805 walk_fn_kind(visitor, function_kind);
806 visitor.visit_nested_body(body_id)
809 pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem) {
810 visitor.visit_name(trait_item.span, trait_item.name);
811 walk_list!(visitor, visit_attribute, &trait_item.attrs);
812 match trait_item.node {
813 TraitItemKind::Const(ref ty, default) => {
814 visitor.visit_id(trait_item.id);
815 visitor.visit_ty(ty);
816 walk_list!(visitor, visit_nested_body, default);
818 TraitItemKind::Method(ref sig, TraitMethod::Required(ref names)) => {
819 visitor.visit_id(trait_item.id);
820 visitor.visit_generics(&sig.generics);
821 visitor.visit_fn_decl(&sig.decl);
823 visitor.visit_name(name.span, name.node);
826 TraitItemKind::Method(ref sig, TraitMethod::Provided(body_id)) => {
827 visitor.visit_fn(FnKind::Method(trait_item.name,
836 TraitItemKind::Type(ref bounds, ref default) => {
837 visitor.visit_id(trait_item.id);
838 walk_list!(visitor, visit_ty_param_bound, bounds);
839 walk_list!(visitor, visit_ty, default);
844 pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref: &'v TraitItemRef) {
845 // NB: Deliberately force a compilation error if/when new fields are added.
846 let TraitItemRef { id, name, ref kind, span, ref defaultness } = *trait_item_ref;
847 visitor.visit_nested_trait_item(id);
848 visitor.visit_name(span, name);
849 visitor.visit_associated_item_kind(kind);
850 visitor.visit_defaultness(defaultness);
853 pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem) {
854 // NB: Deliberately force a compilation error if/when new fields are added.
855 let ImplItem { id: _, name, ref vis, ref defaultness, ref attrs, ref node, span } = *impl_item;
857 visitor.visit_name(span, name);
858 visitor.visit_vis(vis);
859 visitor.visit_defaultness(defaultness);
860 walk_list!(visitor, visit_attribute, attrs);
862 ImplItemKind::Const(ref ty, body) => {
863 visitor.visit_id(impl_item.id);
864 visitor.visit_ty(ty);
865 visitor.visit_nested_body(body);
867 ImplItemKind::Method(ref sig, body_id) => {
868 visitor.visit_fn(FnKind::Method(impl_item.name,
870 Some(&impl_item.vis),
877 ImplItemKind::Type(ref ty) => {
878 visitor.visit_id(impl_item.id);
879 visitor.visit_ty(ty);
884 pub fn walk_impl_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, impl_item_ref: &'v ImplItemRef) {
885 // NB: Deliberately force a compilation error if/when new fields are added.
886 let ImplItemRef { id, name, ref kind, span, ref vis, ref defaultness } = *impl_item_ref;
887 visitor.visit_nested_impl_item(id);
888 visitor.visit_name(span, name);
889 visitor.visit_associated_item_kind(kind);
890 visitor.visit_vis(vis);
891 visitor.visit_defaultness(defaultness);
895 pub fn walk_struct_def<'v, V: Visitor<'v>>(visitor: &mut V, struct_definition: &'v VariantData) {
896 visitor.visit_id(struct_definition.id());
897 walk_list!(visitor, visit_struct_field, struct_definition.fields());
900 pub fn walk_struct_field<'v, V: Visitor<'v>>(visitor: &mut V, struct_field: &'v StructField) {
901 visitor.visit_id(struct_field.id);
902 visitor.visit_vis(&struct_field.vis);
903 visitor.visit_name(struct_field.span, struct_field.name);
904 visitor.visit_ty(&struct_field.ty);
905 walk_list!(visitor, visit_attribute, &struct_field.attrs);
908 pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block) {
909 visitor.visit_id(block.id);
910 walk_list!(visitor, visit_stmt, &block.stmts);
911 walk_list!(visitor, visit_expr, &block.expr);
914 pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt) {
915 match statement.node {
916 StmtDecl(ref declaration, id) => {
917 visitor.visit_id(id);
918 visitor.visit_decl(declaration)
920 StmtExpr(ref expression, id) |
921 StmtSemi(ref expression, id) => {
922 visitor.visit_id(id);
923 visitor.visit_expr(expression)
928 pub fn walk_decl<'v, V: Visitor<'v>>(visitor: &mut V, declaration: &'v Decl) {
929 match declaration.node {
930 DeclLocal(ref local) => visitor.visit_local(local),
931 DeclItem(item) => visitor.visit_nested_item(item),
935 pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
936 visitor.visit_id(expression.id);
937 walk_list!(visitor, visit_attribute, expression.attrs.iter());
938 match expression.node {
939 ExprBox(ref subexpression) => {
940 visitor.visit_expr(subexpression)
942 ExprArray(ref subexpressions) => {
943 walk_list!(visitor, visit_expr, subexpressions);
945 ExprRepeat(ref element, count) => {
946 visitor.visit_expr(element);
947 visitor.visit_nested_body(count)
949 ExprStruct(ref qpath, ref fields, ref optional_base) => {
950 visitor.visit_qpath(qpath, expression.id, expression.span);
951 for field in fields {
952 visitor.visit_name(field.name.span, field.name.node);
953 visitor.visit_expr(&field.expr)
955 walk_list!(visitor, visit_expr, optional_base);
957 ExprTup(ref subexpressions) => {
958 walk_list!(visitor, visit_expr, subexpressions);
960 ExprCall(ref callee_expression, ref arguments) => {
961 walk_list!(visitor, visit_expr, arguments);
962 visitor.visit_expr(callee_expression)
964 ExprMethodCall(ref name, ref types, ref arguments) => {
965 visitor.visit_name(name.span, name.node);
966 walk_list!(visitor, visit_expr, arguments);
967 walk_list!(visitor, visit_ty, types);
969 ExprBinary(_, ref left_expression, ref right_expression) => {
970 visitor.visit_expr(left_expression);
971 visitor.visit_expr(right_expression)
973 ExprAddrOf(_, ref subexpression) | ExprUnary(_, ref subexpression) => {
974 visitor.visit_expr(subexpression)
977 ExprCast(ref subexpression, ref typ) | ExprType(ref subexpression, ref typ) => {
978 visitor.visit_expr(subexpression);
979 visitor.visit_ty(typ)
981 ExprIf(ref head_expression, ref if_block, ref optional_else) => {
982 visitor.visit_expr(head_expression);
983 visitor.visit_expr(if_block);
984 walk_list!(visitor, visit_expr, optional_else);
986 ExprWhile(ref subexpression, ref block, ref opt_sp_name) => {
987 visitor.visit_expr(subexpression);
988 visitor.visit_block(block);
989 walk_opt_sp_name(visitor, opt_sp_name);
991 ExprLoop(ref block, ref opt_sp_name, _) => {
992 visitor.visit_block(block);
993 walk_opt_sp_name(visitor, opt_sp_name);
995 ExprMatch(ref subexpression, ref arms, _) => {
996 visitor.visit_expr(subexpression);
997 walk_list!(visitor, visit_arm, arms);
999 ExprClosure(_, ref function_declaration, body, _fn_decl_span) => {
1000 visitor.visit_fn(FnKind::Closure(&expression.attrs),
1001 function_declaration,
1006 ExprBlock(ref block) => visitor.visit_block(block),
1007 ExprAssign(ref left_hand_expression, ref right_hand_expression) => {
1008 visitor.visit_expr(right_hand_expression);
1009 visitor.visit_expr(left_hand_expression)
1011 ExprAssignOp(_, ref left_expression, ref right_expression) => {
1012 visitor.visit_expr(right_expression);
1013 visitor.visit_expr(left_expression)
1015 ExprField(ref subexpression, ref name) => {
1016 visitor.visit_expr(subexpression);
1017 visitor.visit_name(name.span, name.node);
1019 ExprTupField(ref subexpression, _) => {
1020 visitor.visit_expr(subexpression);
1022 ExprIndex(ref main_expression, ref index_expression) => {
1023 visitor.visit_expr(main_expression);
1024 visitor.visit_expr(index_expression)
1026 ExprPath(ref qpath) => {
1027 visitor.visit_qpath(qpath, expression.id, expression.span);
1029 ExprBreak(label, ref opt_expr) => {
1030 label.ident.map(|ident| {
1031 match label.target_id {
1032 ScopeTarget::Block(node_id) |
1033 ScopeTarget::Loop(LoopIdResult::Ok(node_id)) =>
1034 visitor.visit_def_mention(Def::Label(node_id)),
1035 ScopeTarget::Loop(LoopIdResult::Err(_)) => {},
1037 visitor.visit_name(ident.span, ident.node.name);
1039 walk_list!(visitor, visit_expr, opt_expr);
1041 ExprAgain(label) => {
1042 label.ident.map(|ident| {
1043 match label.target_id {
1044 ScopeTarget::Block(_) => bug!("can't `continue` to a non-loop block"),
1045 ScopeTarget::Loop(LoopIdResult::Ok(node_id)) =>
1046 visitor.visit_def_mention(Def::Label(node_id)),
1047 ScopeTarget::Loop(LoopIdResult::Err(_)) => {},
1049 visitor.visit_name(ident.span, ident.node.name);
1052 ExprRet(ref optional_expression) => {
1053 walk_list!(visitor, visit_expr, optional_expression);
1055 ExprInlineAsm(_, ref outputs, ref inputs) => {
1056 for output in outputs {
1057 visitor.visit_expr(output)
1059 for input in inputs {
1060 visitor.visit_expr(input)
1066 pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm) {
1067 walk_list!(visitor, visit_pat, &arm.pats);
1068 walk_list!(visitor, visit_expr, &arm.guard);
1069 visitor.visit_expr(&arm.body);
1070 walk_list!(visitor, visit_attribute, &arm.attrs);
1073 pub fn walk_vis<'v, V: Visitor<'v>>(visitor: &mut V, vis: &'v Visibility) {
1074 if let Visibility::Restricted { ref path, id } = *vis {
1075 visitor.visit_id(id);
1076 visitor.visit_path(path, id)
1080 pub fn walk_associated_item_kind<'v, V: Visitor<'v>>(_: &mut V, _: &'v AssociatedItemKind) {
1081 // No visitable content here: this fn exists so you can call it if
1082 // the right thing to do, should content be added in the future,
1083 // would be to walk it.
1086 pub fn walk_defaultness<'v, V: Visitor<'v>>(_: &mut V, _: &'v Defaultness) {
1087 // No visitable content here: this fn exists so you can call it if
1088 // the right thing to do, should content be added in the future,
1089 // would be to walk it.
1092 #[derive(Copy, Clone, RustcEncodable, RustcDecodable, Debug, PartialEq, Eq)]
1093 pub struct IdRange {
1099 pub fn max() -> IdRange {
1101 min: NodeId::from_u32(u32::MAX),
1102 max: NodeId::from_u32(u32::MIN),
1106 pub fn empty(&self) -> bool {
1107 self.min >= self.max
1110 pub fn contains(&self, id: NodeId) -> bool {
1111 id >= self.min && id < self.max
1114 pub fn add(&mut self, id: NodeId) {
1115 self.min = cmp::min(self.min, id);
1116 self.max = cmp::max(self.max, NodeId::from_u32(id.as_u32() + 1));
1122 pub struct IdRangeComputingVisitor<'a, 'hir: 'a> {
1124 map: &'a map::Map<'hir>,
1127 impl<'a, 'hir> IdRangeComputingVisitor<'a, 'hir> {
1128 pub fn new(map: &'a map::Map<'hir>) -> IdRangeComputingVisitor<'a, 'hir> {
1129 IdRangeComputingVisitor { result: IdRange::max(), map: map }
1132 pub fn result(&self) -> IdRange {
1137 impl<'a, 'hir> Visitor<'hir> for IdRangeComputingVisitor<'a, 'hir> {
1138 fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'hir> {
1139 NestedVisitorMap::OnlyBodies(&self.map)
1142 fn visit_id(&mut self, id: NodeId) {
1143 self.result.add(id);