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 //! AST walker. Each overridden visit method has full control over what
12 //! happens with its node, it can do its own traversal of the node's children,
13 //! call `visit::walk_*` to apply the default traversal algorithm, or prevent
14 //! deeper traversal by doing nothing.
16 //! Note: it is an important invariant that the default visitor walks the body
17 //! of a function in "execution order" (more concretely, reverse post-order
18 //! with respect to the CFG implied by the AST), meaning that if AST node A may
19 //! execute before AST node B, then A is visited first. The borrow checker in
20 //! particular relies on this property.
22 //! Note: walking an AST before macro expansion is probably a bad idea. For
23 //! instance, a walker looking for item names in a module will miss all of
24 //! those that are created by the expansion of a macro.
31 #[derive(Copy, Clone, PartialEq, Eq)]
33 /// fn foo() or extern "Abi" fn foo()
34 ItemFn(Ident, &'a Generics, Unsafety, Spanned<Constness>, Abi, &'a Visibility, &'a Block),
37 Method(Ident, &'a MethodSig, Option<&'a Visibility>, &'a Block),
43 /// Each method of the Visitor trait is a hook to be potentially
44 /// overridden. Each method's default implementation recursively visits
45 /// the substructure of the input via the corresponding `walk` method;
46 /// e.g. the `visit_mod` method by default calls `visit::walk_mod`.
48 /// If you want to ensure that your code handles every variant
49 /// explicitly, you need to override each method. (And you also need
50 /// to monitor future changes to `Visitor` in case a new method with a
51 /// new default implementation gets introduced.)
52 pub trait Visitor<'ast>: Sized {
53 fn visit_name(&mut self, _span: Span, _name: Name) {
56 fn visit_ident(&mut self, span: Span, ident: Ident) {
57 walk_ident(self, span, ident);
59 fn visit_mod(&mut self, m: &'ast Mod, _s: Span, _n: NodeId) { walk_mod(self, m) }
60 fn visit_foreign_item(&mut self, i: &'ast ForeignItem) { walk_foreign_item(self, i) }
61 fn visit_item(&mut self, i: &'ast Item) { walk_item(self, i) }
62 fn visit_local(&mut self, l: &'ast Local) { walk_local(self, l) }
63 fn visit_block(&mut self, b: &'ast Block) { walk_block(self, b) }
64 fn visit_stmt(&mut self, s: &'ast Stmt) { walk_stmt(self, s) }
65 fn visit_arm(&mut self, a: &'ast Arm) { walk_arm(self, a) }
66 fn visit_pat(&mut self, p: &'ast Pat) { walk_pat(self, p) }
67 fn visit_expr(&mut self, ex: &'ast Expr) { walk_expr(self, ex) }
68 fn visit_expr_post(&mut self, _ex: &'ast Expr) { }
69 fn visit_ty(&mut self, t: &'ast Ty) { walk_ty(self, t) }
70 fn visit_generics(&mut self, g: &'ast Generics) { walk_generics(self, g) }
71 fn visit_where_predicate(&mut self, p: &'ast WherePredicate) {
72 walk_where_predicate(self, p)
74 fn visit_fn(&mut self, fk: FnKind<'ast>, fd: &'ast FnDecl, s: Span, _: NodeId) {
75 walk_fn(self, fk, fd, s)
77 fn visit_trait_item(&mut self, ti: &'ast TraitItem) { walk_trait_item(self, ti) }
78 fn visit_impl_item(&mut self, ii: &'ast ImplItem) { walk_impl_item(self, ii) }
79 fn visit_trait_ref(&mut self, t: &'ast TraitRef) { walk_trait_ref(self, t) }
80 fn visit_ty_param_bound(&mut self, bounds: &'ast TyParamBound) {
81 walk_ty_param_bound(self, bounds)
83 fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef, m: &'ast TraitBoundModifier) {
84 walk_poly_trait_ref(self, t, m)
86 fn visit_variant_data(&mut self, s: &'ast VariantData, _: Ident,
87 _: &'ast Generics, _: NodeId, _: Span) {
88 walk_struct_def(self, s)
90 fn visit_struct_field(&mut self, s: &'ast StructField) { walk_struct_field(self, s) }
91 fn visit_enum_def(&mut self, enum_definition: &'ast EnumDef,
92 generics: &'ast Generics, item_id: NodeId, _: Span) {
93 walk_enum_def(self, enum_definition, generics, item_id)
95 fn visit_variant(&mut self, v: &'ast Variant, g: &'ast Generics, item_id: NodeId) {
96 walk_variant(self, v, g, item_id)
98 fn visit_lifetime(&mut self, lifetime: &'ast Lifetime) {
99 walk_lifetime(self, lifetime)
101 fn visit_lifetime_def(&mut self, lifetime: &'ast LifetimeDef) {
102 walk_lifetime_def(self, lifetime)
104 fn visit_mac(&mut self, _mac: &'ast Mac) {
105 panic!("visit_mac disabled by default");
106 // NB: see note about macros above.
107 // if you really want a visitor that
108 // works on macros, use this
109 // definition in your trait impl:
110 // visit::walk_mac(self, _mac)
112 fn visit_path(&mut self, path: &'ast Path, _id: NodeId) {
113 walk_path(self, path)
115 fn visit_path_list_item(&mut self, prefix: &'ast Path, item: &'ast PathListItem) {
116 walk_path_list_item(self, prefix, item)
118 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'ast PathSegment) {
119 walk_path_segment(self, path_span, path_segment)
121 fn visit_path_parameters(&mut self, path_span: Span, path_parameters: &'ast PathParameters) {
122 walk_path_parameters(self, path_span, path_parameters)
124 fn visit_assoc_type_binding(&mut self, type_binding: &'ast TypeBinding) {
125 walk_assoc_type_binding(self, type_binding)
127 fn visit_attribute(&mut self, _attr: &'ast Attribute) {}
128 fn visit_vis(&mut self, vis: &'ast Visibility) {
131 fn visit_fn_ret_ty(&mut self, ret_ty: &'ast FunctionRetTy) {
132 walk_fn_ret_ty(self, ret_ty)
137 macro_rules! walk_list {
138 ($visitor: expr, $method: ident, $list: expr) => {
140 $visitor.$method(elem)
143 ($visitor: expr, $method: ident, $list: expr, $($extra_args: expr),*) => {
145 $visitor.$method(elem, $($extra_args,)*)
150 pub fn walk_opt_name<'a, V: Visitor<'a>>(visitor: &mut V, span: Span, opt_name: Option<Name>) {
151 if let Some(name) = opt_name {
152 visitor.visit_name(span, name);
156 pub fn walk_opt_ident<'a, V: Visitor<'a>>(visitor: &mut V, span: Span, opt_ident: Option<Ident>) {
157 if let Some(ident) = opt_ident {
158 visitor.visit_ident(span, ident);
162 pub fn walk_opt_sp_ident<'a, V: Visitor<'a>>(visitor: &mut V,
163 opt_sp_ident: &Option<Spanned<Ident>>) {
164 if let Some(ref sp_ident) = *opt_sp_ident {
165 visitor.visit_ident(sp_ident.span, sp_ident.node);
169 pub fn walk_ident<'a, V: Visitor<'a>>(visitor: &mut V, span: Span, ident: Ident) {
170 visitor.visit_name(span, ident.name);
173 pub fn walk_crate<'a, V: Visitor<'a>>(visitor: &mut V, krate: &'a Crate) {
174 visitor.visit_mod(&krate.module, krate.span, CRATE_NODE_ID);
175 walk_list!(visitor, visit_attribute, &krate.attrs);
178 pub fn walk_mod<'a, V: Visitor<'a>>(visitor: &mut V, module: &'a Mod) {
179 walk_list!(visitor, visit_item, &module.items);
182 pub fn walk_local<'a, V: Visitor<'a>>(visitor: &mut V, local: &'a Local) {
183 for attr in local.attrs.iter() {
184 visitor.visit_attribute(attr);
186 visitor.visit_pat(&local.pat);
187 walk_list!(visitor, visit_ty, &local.ty);
188 walk_list!(visitor, visit_expr, &local.init);
191 pub fn walk_lifetime<'a, V: Visitor<'a>>(visitor: &mut V, lifetime: &'a Lifetime) {
192 visitor.visit_name(lifetime.span, lifetime.name);
195 pub fn walk_lifetime_def<'a, V: Visitor<'a>>(visitor: &mut V, lifetime_def: &'a LifetimeDef) {
196 visitor.visit_lifetime(&lifetime_def.lifetime);
197 walk_list!(visitor, visit_lifetime, &lifetime_def.bounds);
198 walk_list!(visitor, visit_attribute, &*lifetime_def.attrs);
201 pub fn walk_poly_trait_ref<'a, V>(visitor: &mut V,
202 trait_ref: &'a PolyTraitRef,
203 _: &TraitBoundModifier)
204 where V: Visitor<'a>,
206 walk_list!(visitor, visit_lifetime_def, &trait_ref.bound_lifetimes);
207 visitor.visit_trait_ref(&trait_ref.trait_ref);
210 pub fn walk_trait_ref<'a, V: Visitor<'a>>(visitor: &mut V, trait_ref: &'a TraitRef) {
211 visitor.visit_path(&trait_ref.path, trait_ref.ref_id)
214 pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
215 visitor.visit_vis(&item.vis);
216 visitor.visit_ident(item.span, item.ident);
218 ItemKind::ExternCrate(opt_name) => {
219 walk_opt_name(visitor, item.span, opt_name)
221 ItemKind::Use(ref vp) => {
223 ViewPathSimple(ident, ref path) => {
224 visitor.visit_ident(vp.span, ident);
225 visitor.visit_path(path, item.id);
227 ViewPathGlob(ref path) => {
228 visitor.visit_path(path, item.id);
230 ViewPathList(ref prefix, ref list) => {
231 visitor.visit_path(prefix, item.id);
233 visitor.visit_path_list_item(prefix, item)
238 ItemKind::Static(ref typ, _, ref expr) |
239 ItemKind::Const(ref typ, ref expr) => {
240 visitor.visit_ty(typ);
241 visitor.visit_expr(expr);
243 ItemKind::Fn(ref declaration, unsafety, constness, abi, ref generics, ref body) => {
244 visitor.visit_fn(FnKind::ItemFn(item.ident, generics, unsafety,
245 constness, abi, &item.vis, body),
250 ItemKind::Mod(ref module) => {
251 visitor.visit_mod(module, item.span, item.id)
253 ItemKind::ForeignMod(ref foreign_module) => {
254 walk_list!(visitor, visit_foreign_item, &foreign_module.items);
256 ItemKind::Ty(ref typ, ref type_parameters) => {
257 visitor.visit_ty(typ);
258 visitor.visit_generics(type_parameters)
260 ItemKind::Enum(ref enum_definition, ref type_parameters) => {
261 visitor.visit_generics(type_parameters);
262 visitor.visit_enum_def(enum_definition, type_parameters, item.id, item.span)
264 ItemKind::DefaultImpl(_, ref trait_ref) => {
265 visitor.visit_trait_ref(trait_ref)
269 ref opt_trait_reference,
272 visitor.visit_generics(type_parameters);
273 walk_list!(visitor, visit_trait_ref, opt_trait_reference);
274 visitor.visit_ty(typ);
275 walk_list!(visitor, visit_impl_item, impl_items);
277 ItemKind::Struct(ref struct_definition, ref generics) |
278 ItemKind::Union(ref struct_definition, ref generics) => {
279 visitor.visit_generics(generics);
280 visitor.visit_variant_data(struct_definition, item.ident,
281 generics, item.id, item.span);
283 ItemKind::Trait(_, ref generics, ref bounds, ref methods) => {
284 visitor.visit_generics(generics);
285 walk_list!(visitor, visit_ty_param_bound, bounds);
286 walk_list!(visitor, visit_trait_item, methods);
288 ItemKind::Mac(ref mac) => visitor.visit_mac(mac),
289 ItemKind::MacroDef(..) => {},
291 walk_list!(visitor, visit_attribute, &item.attrs);
294 pub fn walk_enum_def<'a, V: Visitor<'a>>(visitor: &mut V,
295 enum_definition: &'a EnumDef,
296 generics: &'a Generics,
298 walk_list!(visitor, visit_variant, &enum_definition.variants, generics, item_id);
301 pub fn walk_variant<'a, V>(visitor: &mut V,
302 variant: &'a Variant,
303 generics: &'a Generics,
305 where V: Visitor<'a>,
307 visitor.visit_ident(variant.span, variant.node.name);
308 visitor.visit_variant_data(&variant.node.data, variant.node.name,
309 generics, item_id, variant.span);
310 walk_list!(visitor, visit_expr, &variant.node.disr_expr);
311 walk_list!(visitor, visit_attribute, &variant.node.attrs);
314 pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) {
316 TyKind::Slice(ref ty) | TyKind::Paren(ref ty) => {
319 TyKind::Ptr(ref mutable_type) => {
320 visitor.visit_ty(&mutable_type.ty)
322 TyKind::Rptr(ref opt_lifetime, ref mutable_type) => {
323 walk_list!(visitor, visit_lifetime, opt_lifetime);
324 visitor.visit_ty(&mutable_type.ty)
327 TyKind::Tup(ref tuple_element_types) => {
328 walk_list!(visitor, visit_ty, tuple_element_types);
330 TyKind::BareFn(ref function_declaration) => {
331 walk_fn_decl(visitor, &function_declaration.decl);
332 walk_list!(visitor, visit_lifetime_def, &function_declaration.lifetimes);
334 TyKind::Path(ref maybe_qself, ref path) => {
335 if let Some(ref qself) = *maybe_qself {
336 visitor.visit_ty(&qself.ty);
338 visitor.visit_path(path, typ.id);
340 TyKind::Array(ref ty, ref expression) => {
341 visitor.visit_ty(ty);
342 visitor.visit_expr(expression)
344 TyKind::TraitObject(ref bounds) => {
345 walk_list!(visitor, visit_ty_param_bound, bounds);
347 TyKind::ImplTrait(ref bounds) => {
348 walk_list!(visitor, visit_ty_param_bound, bounds);
350 TyKind::Typeof(ref expression) => {
351 visitor.visit_expr(expression)
353 TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => {}
354 TyKind::Mac(ref mac) => {
355 visitor.visit_mac(mac)
360 pub fn walk_path<'a, V: Visitor<'a>>(visitor: &mut V, path: &'a Path) {
361 for segment in &path.segments {
362 visitor.visit_path_segment(path.span, segment);
366 pub fn walk_path_list_item<'a, V: Visitor<'a>>(visitor: &mut V,
368 item: &'a PathListItem) {
369 visitor.visit_ident(item.span, item.node.name);
370 walk_opt_ident(visitor, item.span, item.node.rename);
373 pub fn walk_path_segment<'a, V: Visitor<'a>>(visitor: &mut V,
375 segment: &'a PathSegment) {
376 visitor.visit_ident(path_span, segment.identifier);
377 if let Some(ref parameters) = segment.parameters {
378 visitor.visit_path_parameters(path_span, parameters);
382 pub fn walk_path_parameters<'a, V>(visitor: &mut V,
384 path_parameters: &'a PathParameters)
385 where V: Visitor<'a>,
387 match *path_parameters {
388 PathParameters::AngleBracketed(ref data) => {
389 walk_list!(visitor, visit_ty, &data.types);
390 walk_list!(visitor, visit_lifetime, &data.lifetimes);
391 walk_list!(visitor, visit_assoc_type_binding, &data.bindings);
393 PathParameters::Parenthesized(ref data) => {
394 walk_list!(visitor, visit_ty, &data.inputs);
395 walk_list!(visitor, visit_ty, &data.output);
400 pub fn walk_assoc_type_binding<'a, V: Visitor<'a>>(visitor: &mut V,
401 type_binding: &'a TypeBinding) {
402 visitor.visit_ident(type_binding.span, type_binding.ident);
403 visitor.visit_ty(&type_binding.ty);
406 pub fn walk_pat<'a, V: Visitor<'a>>(visitor: &mut V, pattern: &'a Pat) {
408 PatKind::TupleStruct(ref path, ref children, _) => {
409 visitor.visit_path(path, pattern.id);
410 walk_list!(visitor, visit_pat, children);
412 PatKind::Path(ref opt_qself, ref path) => {
413 if let Some(ref qself) = *opt_qself {
414 visitor.visit_ty(&qself.ty);
416 visitor.visit_path(path, pattern.id)
418 PatKind::Struct(ref path, ref fields, _) => {
419 visitor.visit_path(path, pattern.id);
420 for field in fields {
421 walk_list!(visitor, visit_attribute, field.node.attrs.iter());
422 visitor.visit_ident(field.span, field.node.ident);
423 visitor.visit_pat(&field.node.pat)
426 PatKind::Tuple(ref tuple_elements, _) => {
427 walk_list!(visitor, visit_pat, tuple_elements);
429 PatKind::Box(ref subpattern) |
430 PatKind::Ref(ref subpattern, _) => {
431 visitor.visit_pat(subpattern)
433 PatKind::Ident(_, ref pth1, ref optional_subpattern) => {
434 visitor.visit_ident(pth1.span, pth1.node);
435 walk_list!(visitor, visit_pat, optional_subpattern);
437 PatKind::Lit(ref expression) => visitor.visit_expr(expression),
438 PatKind::Range(ref lower_bound, ref upper_bound, _) => {
439 visitor.visit_expr(lower_bound);
440 visitor.visit_expr(upper_bound);
443 PatKind::Slice(ref prepatterns, ref slice_pattern, ref postpatterns) => {
444 walk_list!(visitor, visit_pat, prepatterns);
445 walk_list!(visitor, visit_pat, slice_pattern);
446 walk_list!(visitor, visit_pat, postpatterns);
448 PatKind::Mac(ref mac) => visitor.visit_mac(mac),
452 pub fn walk_foreign_item<'a, V: Visitor<'a>>(visitor: &mut V, foreign_item: &'a ForeignItem) {
453 visitor.visit_vis(&foreign_item.vis);
454 visitor.visit_ident(foreign_item.span, foreign_item.ident);
456 match foreign_item.node {
457 ForeignItemKind::Fn(ref function_declaration, ref generics) => {
458 walk_fn_decl(visitor, function_declaration);
459 visitor.visit_generics(generics)
461 ForeignItemKind::Static(ref typ, _) => visitor.visit_ty(typ),
464 walk_list!(visitor, visit_attribute, &foreign_item.attrs);
467 pub fn walk_ty_param_bound<'a, V: Visitor<'a>>(visitor: &mut V, bound: &'a TyParamBound) {
469 TraitTyParamBound(ref typ, ref modifier) => {
470 visitor.visit_poly_trait_ref(typ, modifier);
472 RegionTyParamBound(ref lifetime) => {
473 visitor.visit_lifetime(lifetime);
478 pub fn walk_generics<'a, V: Visitor<'a>>(visitor: &mut V, generics: &'a Generics) {
479 for param in &generics.ty_params {
480 visitor.visit_ident(param.span, param.ident);
481 walk_list!(visitor, visit_ty_param_bound, ¶m.bounds);
482 walk_list!(visitor, visit_ty, ¶m.default);
483 walk_list!(visitor, visit_attribute, &*param.attrs);
485 walk_list!(visitor, visit_lifetime_def, &generics.lifetimes);
486 walk_list!(visitor, visit_where_predicate, &generics.where_clause.predicates);
489 pub fn walk_where_predicate<'a, V: Visitor<'a>>(visitor: &mut V, predicate: &'a WherePredicate) {
491 WherePredicate::BoundPredicate(WhereBoundPredicate{ref bounded_ty,
495 visitor.visit_ty(bounded_ty);
496 walk_list!(visitor, visit_ty_param_bound, bounds);
497 walk_list!(visitor, visit_lifetime_def, bound_lifetimes);
499 WherePredicate::RegionPredicate(WhereRegionPredicate{ref lifetime,
502 visitor.visit_lifetime(lifetime);
503 walk_list!(visitor, visit_lifetime, bounds);
505 WherePredicate::EqPredicate(WhereEqPredicate{ref lhs_ty,
508 visitor.visit_ty(lhs_ty);
509 visitor.visit_ty(rhs_ty);
514 pub fn walk_fn_ret_ty<'a, V: Visitor<'a>>(visitor: &mut V, ret_ty: &'a FunctionRetTy) {
515 if let FunctionRetTy::Ty(ref output_ty) = *ret_ty {
516 visitor.visit_ty(output_ty)
520 pub fn walk_fn_decl<'a, V: Visitor<'a>>(visitor: &mut V, function_declaration: &'a FnDecl) {
521 for argument in &function_declaration.inputs {
522 visitor.visit_pat(&argument.pat);
523 visitor.visit_ty(&argument.ty)
525 visitor.visit_fn_ret_ty(&function_declaration.output)
528 pub fn walk_fn<'a, V>(visitor: &mut V, kind: FnKind<'a>, declaration: &'a FnDecl, _span: Span)
529 where V: Visitor<'a>,
532 FnKind::ItemFn(_, generics, _, _, _, _, body) => {
533 visitor.visit_generics(generics);
534 walk_fn_decl(visitor, declaration);
535 visitor.visit_block(body);
537 FnKind::Method(_, ref sig, _, body) => {
538 visitor.visit_generics(&sig.generics);
539 walk_fn_decl(visitor, declaration);
540 visitor.visit_block(body);
542 FnKind::Closure(body) => {
543 walk_fn_decl(visitor, declaration);
544 visitor.visit_expr(body);
549 pub fn walk_trait_item<'a, V: Visitor<'a>>(visitor: &mut V, trait_item: &'a TraitItem) {
550 visitor.visit_ident(trait_item.span, trait_item.ident);
551 walk_list!(visitor, visit_attribute, &trait_item.attrs);
552 match trait_item.node {
553 TraitItemKind::Const(ref ty, ref default) => {
554 visitor.visit_ty(ty);
555 walk_list!(visitor, visit_expr, default);
557 TraitItemKind::Method(ref sig, None) => {
558 visitor.visit_generics(&sig.generics);
559 walk_fn_decl(visitor, &sig.decl);
561 TraitItemKind::Method(ref sig, Some(ref body)) => {
562 visitor.visit_fn(FnKind::Method(trait_item.ident, sig, None, body),
563 &sig.decl, trait_item.span, trait_item.id);
565 TraitItemKind::Type(ref bounds, ref default) => {
566 walk_list!(visitor, visit_ty_param_bound, bounds);
567 walk_list!(visitor, visit_ty, default);
569 TraitItemKind::Macro(ref mac) => {
570 visitor.visit_mac(mac);
575 pub fn walk_impl_item<'a, V: Visitor<'a>>(visitor: &mut V, impl_item: &'a ImplItem) {
576 visitor.visit_vis(&impl_item.vis);
577 visitor.visit_ident(impl_item.span, impl_item.ident);
578 walk_list!(visitor, visit_attribute, &impl_item.attrs);
579 match impl_item.node {
580 ImplItemKind::Const(ref ty, ref expr) => {
581 visitor.visit_ty(ty);
582 visitor.visit_expr(expr);
584 ImplItemKind::Method(ref sig, ref body) => {
585 visitor.visit_fn(FnKind::Method(impl_item.ident, sig, Some(&impl_item.vis), body),
586 &sig.decl, impl_item.span, impl_item.id);
588 ImplItemKind::Type(ref ty) => {
589 visitor.visit_ty(ty);
591 ImplItemKind::Macro(ref mac) => {
592 visitor.visit_mac(mac);
597 pub fn walk_struct_def<'a, V: Visitor<'a>>(visitor: &mut V, struct_definition: &'a VariantData) {
598 walk_list!(visitor, visit_struct_field, struct_definition.fields());
601 pub fn walk_struct_field<'a, V: Visitor<'a>>(visitor: &mut V, struct_field: &'a StructField) {
602 visitor.visit_vis(&struct_field.vis);
603 walk_opt_ident(visitor, struct_field.span, struct_field.ident);
604 visitor.visit_ty(&struct_field.ty);
605 walk_list!(visitor, visit_attribute, &struct_field.attrs);
608 pub fn walk_block<'a, V: Visitor<'a>>(visitor: &mut V, block: &'a Block) {
609 walk_list!(visitor, visit_stmt, &block.stmts);
612 pub fn walk_stmt<'a, V: Visitor<'a>>(visitor: &mut V, statement: &'a Stmt) {
613 match statement.node {
614 StmtKind::Local(ref local) => visitor.visit_local(local),
615 StmtKind::Item(ref item) => visitor.visit_item(item),
616 StmtKind::Expr(ref expression) | StmtKind::Semi(ref expression) => {
617 visitor.visit_expr(expression)
619 StmtKind::Mac(ref mac) => {
620 let (ref mac, _, ref attrs) = **mac;
621 visitor.visit_mac(mac);
622 for attr in attrs.iter() {
623 visitor.visit_attribute(attr);
629 pub fn walk_mac<'a, V: Visitor<'a>>(_: &mut V, _: &Mac) {
633 pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
634 for attr in expression.attrs.iter() {
635 visitor.visit_attribute(attr);
637 match expression.node {
638 ExprKind::Box(ref subexpression) => {
639 visitor.visit_expr(subexpression)
641 ExprKind::InPlace(ref place, ref subexpression) => {
642 visitor.visit_expr(place);
643 visitor.visit_expr(subexpression)
645 ExprKind::Array(ref subexpressions) => {
646 walk_list!(visitor, visit_expr, subexpressions);
648 ExprKind::Repeat(ref element, ref count) => {
649 visitor.visit_expr(element);
650 visitor.visit_expr(count)
652 ExprKind::Struct(ref path, ref fields, ref optional_base) => {
653 visitor.visit_path(path, expression.id);
654 for field in fields {
655 walk_list!(visitor, visit_attribute, field.attrs.iter());
656 visitor.visit_ident(field.ident.span, field.ident.node);
657 visitor.visit_expr(&field.expr)
659 walk_list!(visitor, visit_expr, optional_base);
661 ExprKind::Tup(ref subexpressions) => {
662 walk_list!(visitor, visit_expr, subexpressions);
664 ExprKind::Call(ref callee_expression, ref arguments) => {
665 visitor.visit_expr(callee_expression);
666 walk_list!(visitor, visit_expr, arguments);
668 ExprKind::MethodCall(ref ident, ref types, ref arguments) => {
669 visitor.visit_ident(ident.span, ident.node);
670 walk_list!(visitor, visit_ty, types);
671 walk_list!(visitor, visit_expr, arguments);
673 ExprKind::Binary(_, ref left_expression, ref right_expression) => {
674 visitor.visit_expr(left_expression);
675 visitor.visit_expr(right_expression)
677 ExprKind::AddrOf(_, ref subexpression) | ExprKind::Unary(_, ref subexpression) => {
678 visitor.visit_expr(subexpression)
680 ExprKind::Lit(_) => {}
681 ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => {
682 visitor.visit_expr(subexpression);
683 visitor.visit_ty(typ)
685 ExprKind::If(ref head_expression, ref if_block, ref optional_else) => {
686 visitor.visit_expr(head_expression);
687 visitor.visit_block(if_block);
688 walk_list!(visitor, visit_expr, optional_else);
690 ExprKind::While(ref subexpression, ref block, ref opt_sp_ident) => {
691 visitor.visit_expr(subexpression);
692 visitor.visit_block(block);
693 walk_opt_sp_ident(visitor, opt_sp_ident);
695 ExprKind::IfLet(ref pattern, ref subexpression, ref if_block, ref optional_else) => {
696 visitor.visit_pat(pattern);
697 visitor.visit_expr(subexpression);
698 visitor.visit_block(if_block);
699 walk_list!(visitor, visit_expr, optional_else);
701 ExprKind::WhileLet(ref pattern, ref subexpression, ref block, ref opt_sp_ident) => {
702 visitor.visit_pat(pattern);
703 visitor.visit_expr(subexpression);
704 visitor.visit_block(block);
705 walk_opt_sp_ident(visitor, opt_sp_ident);
707 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, ref opt_sp_ident) => {
708 visitor.visit_pat(pattern);
709 visitor.visit_expr(subexpression);
710 visitor.visit_block(block);
711 walk_opt_sp_ident(visitor, opt_sp_ident);
713 ExprKind::Loop(ref block, ref opt_sp_ident) => {
714 visitor.visit_block(block);
715 walk_opt_sp_ident(visitor, opt_sp_ident);
717 ExprKind::Match(ref subexpression, ref arms) => {
718 visitor.visit_expr(subexpression);
719 walk_list!(visitor, visit_arm, arms);
721 ExprKind::Closure(_, ref function_declaration, ref body, _decl_span) => {
722 visitor.visit_fn(FnKind::Closure(body),
723 function_declaration,
727 ExprKind::Block(ref block) => visitor.visit_block(block),
728 ExprKind::Assign(ref left_hand_expression, ref right_hand_expression) => {
729 visitor.visit_expr(left_hand_expression);
730 visitor.visit_expr(right_hand_expression);
732 ExprKind::AssignOp(_, ref left_expression, ref right_expression) => {
733 visitor.visit_expr(left_expression);
734 visitor.visit_expr(right_expression);
736 ExprKind::Field(ref subexpression, ref ident) => {
737 visitor.visit_expr(subexpression);
738 visitor.visit_ident(ident.span, ident.node);
740 ExprKind::TupField(ref subexpression, _) => {
741 visitor.visit_expr(subexpression);
743 ExprKind::Index(ref main_expression, ref index_expression) => {
744 visitor.visit_expr(main_expression);
745 visitor.visit_expr(index_expression)
747 ExprKind::Range(ref start, ref end, _) => {
748 walk_list!(visitor, visit_expr, start);
749 walk_list!(visitor, visit_expr, end);
751 ExprKind::Path(ref maybe_qself, ref path) => {
752 if let Some(ref qself) = *maybe_qself {
753 visitor.visit_ty(&qself.ty);
755 visitor.visit_path(path, expression.id)
757 ExprKind::Break(ref opt_sp_ident, ref opt_expr) => {
758 walk_opt_sp_ident(visitor, opt_sp_ident);
759 walk_list!(visitor, visit_expr, opt_expr);
761 ExprKind::Continue(ref opt_sp_ident) => {
762 walk_opt_sp_ident(visitor, opt_sp_ident);
764 ExprKind::Ret(ref optional_expression) => {
765 walk_list!(visitor, visit_expr, optional_expression);
767 ExprKind::Mac(ref mac) => visitor.visit_mac(mac),
768 ExprKind::Paren(ref subexpression) => {
769 visitor.visit_expr(subexpression)
771 ExprKind::InlineAsm(ref ia) => {
772 for &(_, ref input) in &ia.inputs {
773 visitor.visit_expr(&input)
775 for output in &ia.outputs {
776 visitor.visit_expr(&output.expr)
779 ExprKind::Try(ref subexpression) => {
780 visitor.visit_expr(subexpression)
782 ExprKind::Catch(ref body) => {
783 visitor.visit_block(body)
787 visitor.visit_expr_post(expression)
790 pub fn walk_arm<'a, V: Visitor<'a>>(visitor: &mut V, arm: &'a Arm) {
791 walk_list!(visitor, visit_pat, &arm.pats);
792 walk_list!(visitor, visit_expr, &arm.guard);
793 visitor.visit_expr(&arm.body);
794 walk_list!(visitor, visit_attribute, &arm.attrs);
797 pub fn walk_vis<'a, V: Visitor<'a>>(visitor: &mut V, vis: &'a Visibility) {
798 if let Visibility::Restricted { ref path, id } = *vis {
799 visitor.visit_path(path, id);