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, Constness, Abi, &'a Visibility),
37 Method(Ident, &'a MethodSig, Option<&'a Visibility>),
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: 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: &Mod, _s: Span, _n: NodeId) { walk_mod(self, m) }
60 fn visit_foreign_item(&mut self, i: &ForeignItem) { walk_foreign_item(self, i) }
61 fn visit_item(&mut self, i: &Item) { walk_item(self, i) }
62 fn visit_local(&mut self, l: &Local) { walk_local(self, l) }
63 fn visit_block(&mut self, b: &Block) { walk_block(self, b) }
64 fn visit_stmt(&mut self, s: &Stmt) { walk_stmt(self, s) }
65 fn visit_arm(&mut self, a: &Arm) { walk_arm(self, a) }
66 fn visit_pat(&mut self, p: &Pat) { walk_pat(self, p) }
67 fn visit_expr(&mut self, ex: &Expr) { walk_expr(self, ex) }
68 fn visit_expr_post(&mut self, _ex: &Expr) { }
69 fn visit_ty(&mut self, t: &Ty) { walk_ty(self, t) }
70 fn visit_generics(&mut self, g: &Generics) { walk_generics(self, g) }
71 fn visit_fn(&mut self, fk: FnKind, fd: &FnDecl, b: &Block, s: Span, _: NodeId) {
72 walk_fn(self, fk, fd, b, s)
74 fn visit_trait_item(&mut self, ti: &TraitItem) { walk_trait_item(self, ti) }
75 fn visit_impl_item(&mut self, ii: &ImplItem) { walk_impl_item(self, ii) }
76 fn visit_trait_ref(&mut self, t: &TraitRef) { walk_trait_ref(self, t) }
77 fn visit_ty_param_bound(&mut self, bounds: &TyParamBound) {
78 walk_ty_param_bound(self, bounds)
80 fn visit_poly_trait_ref(&mut self, t: &PolyTraitRef, m: &TraitBoundModifier) {
81 walk_poly_trait_ref(self, t, m)
83 fn visit_variant_data(&mut self, s: &VariantData, _: Ident,
84 _: &Generics, _: NodeId, _: Span) {
85 walk_struct_def(self, s)
87 fn visit_struct_field(&mut self, s: &StructField) { walk_struct_field(self, s) }
88 fn visit_enum_def(&mut self, enum_definition: &EnumDef,
89 generics: &Generics, item_id: NodeId, _: Span) {
90 walk_enum_def(self, enum_definition, generics, item_id)
92 fn visit_variant(&mut self, v: &Variant, g: &Generics, item_id: NodeId) {
93 walk_variant(self, v, g, item_id)
95 fn visit_lifetime(&mut self, lifetime: &Lifetime) {
96 walk_lifetime(self, lifetime)
98 fn visit_lifetime_def(&mut self, lifetime: &LifetimeDef) {
99 walk_lifetime_def(self, lifetime)
101 fn visit_mac(&mut self, _mac: &Mac) {
102 panic!("visit_mac disabled by default");
103 // NB: see note about macros above.
104 // if you really want a visitor that
105 // works on macros, use this
106 // definition in your trait impl:
107 // visit::walk_mac(self, _mac)
109 fn visit_path(&mut self, path: &Path, _id: NodeId) {
110 walk_path(self, path)
112 fn visit_path_list_item(&mut self, prefix: &Path, item: &PathListItem) {
113 walk_path_list_item(self, prefix, item)
115 fn visit_path_segment(&mut self, path_span: Span, path_segment: &PathSegment) {
116 walk_path_segment(self, path_span, path_segment)
118 fn visit_path_parameters(&mut self, path_span: Span, path_parameters: &PathParameters) {
119 walk_path_parameters(self, path_span, path_parameters)
121 fn visit_assoc_type_binding(&mut self, type_binding: &TypeBinding) {
122 walk_assoc_type_binding(self, type_binding)
124 fn visit_attribute(&mut self, _attr: &Attribute) {}
125 fn visit_macro_def(&mut self, macro_def: &MacroDef) {
126 walk_macro_def(self, macro_def)
128 fn visit_vis(&mut self, vis: &Visibility) {
134 macro_rules! walk_list {
135 ($visitor: expr, $method: ident, $list: expr) => {
137 $visitor.$method(elem)
140 ($visitor: expr, $method: ident, $list: expr, $($extra_args: expr),*) => {
142 $visitor.$method(elem, $($extra_args,)*)
147 pub fn walk_opt_name<V: Visitor>(visitor: &mut V, span: Span, opt_name: Option<Name>) {
148 if let Some(name) = opt_name {
149 visitor.visit_name(span, name);
153 pub fn walk_opt_ident<V: Visitor>(visitor: &mut V, span: Span, opt_ident: Option<Ident>) {
154 if let Some(ident) = opt_ident {
155 visitor.visit_ident(span, ident);
159 pub fn walk_opt_sp_ident<V: Visitor>(visitor: &mut V, opt_sp_ident: &Option<Spanned<Ident>>) {
160 if let Some(ref sp_ident) = *opt_sp_ident {
161 visitor.visit_ident(sp_ident.span, sp_ident.node);
165 pub fn walk_ident<V: Visitor>(visitor: &mut V, span: Span, ident: Ident) {
166 visitor.visit_name(span, ident.name);
169 pub fn walk_crate<V: Visitor>(visitor: &mut V, krate: &Crate) {
170 visitor.visit_mod(&krate.module, krate.span, CRATE_NODE_ID);
171 walk_list!(visitor, visit_attribute, &krate.attrs);
172 walk_list!(visitor, visit_macro_def, &krate.exported_macros);
175 pub fn walk_macro_def<V: Visitor>(visitor: &mut V, macro_def: &MacroDef) {
176 visitor.visit_ident(macro_def.span, macro_def.ident);
177 walk_opt_ident(visitor, macro_def.span, macro_def.imported_from);
178 walk_list!(visitor, visit_attribute, ¯o_def.attrs);
181 pub fn walk_mod<V: Visitor>(visitor: &mut V, module: &Mod) {
182 walk_list!(visitor, visit_item, &module.items);
185 pub fn walk_local<V: Visitor>(visitor: &mut V, local: &Local) {
186 for attr in local.attrs.iter() {
187 visitor.visit_attribute(attr);
189 visitor.visit_pat(&local.pat);
190 walk_list!(visitor, visit_ty, &local.ty);
191 walk_list!(visitor, visit_expr, &local.init);
194 pub fn walk_lifetime<V: Visitor>(visitor: &mut V, lifetime: &Lifetime) {
195 visitor.visit_name(lifetime.span, lifetime.name);
198 pub fn walk_lifetime_def<V: Visitor>(visitor: &mut V, lifetime_def: &LifetimeDef) {
199 visitor.visit_lifetime(&lifetime_def.lifetime);
200 walk_list!(visitor, visit_lifetime, &lifetime_def.bounds);
203 pub fn walk_poly_trait_ref<V>(visitor: &mut V, trait_ref: &PolyTraitRef, _: &TraitBoundModifier)
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<V: Visitor>(visitor: &mut V, trait_ref: &TraitRef) {
211 visitor.visit_path(&trait_ref.path, trait_ref.ref_id)
214 pub fn walk_item<V: Visitor>(visitor: &mut V, item: &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),
251 ItemKind::Mod(ref module) => {
252 visitor.visit_mod(module, item.span, item.id)
254 ItemKind::ForeignMod(ref foreign_module) => {
255 walk_list!(visitor, visit_foreign_item, &foreign_module.items);
257 ItemKind::Ty(ref typ, ref type_parameters) => {
258 visitor.visit_ty(typ);
259 visitor.visit_generics(type_parameters)
261 ItemKind::Enum(ref enum_definition, ref type_parameters) => {
262 visitor.visit_generics(type_parameters);
263 visitor.visit_enum_def(enum_definition, type_parameters, item.id, item.span)
265 ItemKind::DefaultImpl(_, ref trait_ref) => {
266 visitor.visit_trait_ref(trait_ref)
270 ref opt_trait_reference,
273 visitor.visit_generics(type_parameters);
274 walk_list!(visitor, visit_trait_ref, opt_trait_reference);
275 visitor.visit_ty(typ);
276 walk_list!(visitor, visit_impl_item, impl_items);
278 ItemKind::Struct(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),
290 walk_list!(visitor, visit_attribute, &item.attrs);
293 pub fn walk_enum_def<V: Visitor>(visitor: &mut V,
294 enum_definition: &EnumDef,
297 walk_list!(visitor, visit_variant, &enum_definition.variants, generics, item_id);
300 pub fn walk_variant<V>(visitor: &mut V, variant: &Variant, generics: &Generics, item_id: NodeId)
303 visitor.visit_ident(variant.span, variant.node.name);
304 visitor.visit_variant_data(&variant.node.data, variant.node.name,
305 generics, item_id, variant.span);
306 walk_list!(visitor, visit_expr, &variant.node.disr_expr);
307 walk_list!(visitor, visit_attribute, &variant.node.attrs);
310 pub fn walk_ty<V: Visitor>(visitor: &mut V, typ: &Ty) {
312 TyKind::Vec(ref ty) | TyKind::Paren(ref ty) => {
315 TyKind::Ptr(ref mutable_type) => {
316 visitor.visit_ty(&mutable_type.ty)
318 TyKind::Rptr(ref opt_lifetime, ref mutable_type) => {
319 walk_list!(visitor, visit_lifetime, opt_lifetime);
320 visitor.visit_ty(&mutable_type.ty)
322 TyKind::Tup(ref tuple_element_types) => {
323 walk_list!(visitor, visit_ty, tuple_element_types);
325 TyKind::BareFn(ref function_declaration) => {
326 walk_fn_decl(visitor, &function_declaration.decl);
327 walk_list!(visitor, visit_lifetime_def, &function_declaration.lifetimes);
329 TyKind::Path(ref maybe_qself, ref path) => {
330 if let Some(ref qself) = *maybe_qself {
331 visitor.visit_ty(&qself.ty);
333 visitor.visit_path(path, typ.id);
335 TyKind::ObjectSum(ref ty, ref bounds) => {
336 visitor.visit_ty(ty);
337 walk_list!(visitor, visit_ty_param_bound, bounds);
339 TyKind::FixedLengthVec(ref ty, ref expression) => {
340 visitor.visit_ty(ty);
341 visitor.visit_expr(expression)
343 TyKind::PolyTraitRef(ref bounds) => {
344 walk_list!(visitor, visit_ty_param_bound, bounds);
346 TyKind::Typeof(ref expression) => {
347 visitor.visit_expr(expression)
349 TyKind::Infer | TyKind::ImplicitSelf => {}
350 TyKind::Mac(ref mac) => {
351 visitor.visit_mac(mac)
356 pub fn walk_path<V: Visitor>(visitor: &mut V, path: &Path) {
357 for segment in &path.segments {
358 visitor.visit_path_segment(path.span, segment);
362 pub fn walk_path_list_item<V: Visitor>(visitor: &mut V, _prefix: &Path, item: &PathListItem) {
363 walk_opt_ident(visitor, item.span, item.node.name());
364 walk_opt_ident(visitor, item.span, item.node.rename());
367 pub fn walk_path_segment<V: Visitor>(visitor: &mut V, path_span: Span, segment: &PathSegment) {
368 visitor.visit_ident(path_span, segment.identifier);
369 visitor.visit_path_parameters(path_span, &segment.parameters);
372 pub fn walk_path_parameters<V>(visitor: &mut V, _path_span: Span, path_parameters: &PathParameters)
375 match *path_parameters {
376 PathParameters::AngleBracketed(ref data) => {
377 walk_list!(visitor, visit_ty, &data.types);
378 walk_list!(visitor, visit_lifetime, &data.lifetimes);
379 walk_list!(visitor, visit_assoc_type_binding, &data.bindings);
381 PathParameters::Parenthesized(ref data) => {
382 walk_list!(visitor, visit_ty, &data.inputs);
383 walk_list!(visitor, visit_ty, &data.output);
388 pub fn walk_assoc_type_binding<V: Visitor>(visitor: &mut V, type_binding: &TypeBinding) {
389 visitor.visit_ident(type_binding.span, type_binding.ident);
390 visitor.visit_ty(&type_binding.ty);
393 pub fn walk_pat<V: Visitor>(visitor: &mut V, pattern: &Pat) {
395 PatKind::TupleStruct(ref path, ref children, _) => {
396 visitor.visit_path(path, pattern.id);
397 walk_list!(visitor, visit_pat, children);
399 PatKind::Path(ref opt_qself, ref path) => {
400 if let Some(ref qself) = *opt_qself {
401 visitor.visit_ty(&qself.ty);
403 visitor.visit_path(path, pattern.id)
405 PatKind::Struct(ref path, ref fields, _) => {
406 visitor.visit_path(path, pattern.id);
407 for field in fields {
408 visitor.visit_ident(field.span, field.node.ident);
409 visitor.visit_pat(&field.node.pat)
412 PatKind::Tuple(ref tuple_elements, _) => {
413 walk_list!(visitor, visit_pat, tuple_elements);
415 PatKind::Box(ref subpattern) |
416 PatKind::Ref(ref subpattern, _) => {
417 visitor.visit_pat(subpattern)
419 PatKind::Ident(_, ref pth1, ref optional_subpattern) => {
420 visitor.visit_ident(pth1.span, pth1.node);
421 walk_list!(visitor, visit_pat, optional_subpattern);
423 PatKind::Lit(ref expression) => visitor.visit_expr(expression),
424 PatKind::Range(ref lower_bound, ref upper_bound) => {
425 visitor.visit_expr(lower_bound);
426 visitor.visit_expr(upper_bound)
429 PatKind::Vec(ref prepatterns, ref slice_pattern, ref postpatterns) => {
430 walk_list!(visitor, visit_pat, prepatterns);
431 walk_list!(visitor, visit_pat, slice_pattern);
432 walk_list!(visitor, visit_pat, postpatterns);
434 PatKind::Mac(ref mac) => visitor.visit_mac(mac),
438 pub fn walk_foreign_item<V: Visitor>(visitor: &mut V, foreign_item: &ForeignItem) {
439 visitor.visit_vis(&foreign_item.vis);
440 visitor.visit_ident(foreign_item.span, foreign_item.ident);
442 match foreign_item.node {
443 ForeignItemKind::Fn(ref function_declaration, ref generics) => {
444 walk_fn_decl(visitor, function_declaration);
445 visitor.visit_generics(generics)
447 ForeignItemKind::Static(ref typ, _) => visitor.visit_ty(typ),
450 walk_list!(visitor, visit_attribute, &foreign_item.attrs);
453 pub fn walk_ty_param_bound<V: Visitor>(visitor: &mut V, bound: &TyParamBound) {
455 TraitTyParamBound(ref typ, ref modifier) => {
456 visitor.visit_poly_trait_ref(typ, modifier);
458 RegionTyParamBound(ref lifetime) => {
459 visitor.visit_lifetime(lifetime);
464 pub fn walk_generics<V: Visitor>(visitor: &mut V, generics: &Generics) {
465 for param in &generics.ty_params {
466 visitor.visit_ident(param.span, param.ident);
467 walk_list!(visitor, visit_ty_param_bound, ¶m.bounds);
468 walk_list!(visitor, visit_ty, ¶m.default);
470 walk_list!(visitor, visit_lifetime_def, &generics.lifetimes);
471 for predicate in &generics.where_clause.predicates {
473 WherePredicate::BoundPredicate(WhereBoundPredicate{ref bounded_ty,
477 visitor.visit_ty(bounded_ty);
478 walk_list!(visitor, visit_ty_param_bound, bounds);
479 walk_list!(visitor, visit_lifetime_def, bound_lifetimes);
481 WherePredicate::RegionPredicate(WhereRegionPredicate{ref lifetime,
484 visitor.visit_lifetime(lifetime);
485 walk_list!(visitor, visit_lifetime, bounds);
487 WherePredicate::EqPredicate(WhereEqPredicate{id,
491 visitor.visit_path(path, id);
492 visitor.visit_ty(ty);
498 pub fn walk_fn_ret_ty<V: Visitor>(visitor: &mut V, ret_ty: &FunctionRetTy) {
499 if let FunctionRetTy::Ty(ref output_ty) = *ret_ty {
500 visitor.visit_ty(output_ty)
504 pub fn walk_fn_decl<V: Visitor>(visitor: &mut V, function_declaration: &FnDecl) {
505 for argument in &function_declaration.inputs {
506 visitor.visit_pat(&argument.pat);
507 visitor.visit_ty(&argument.ty)
509 walk_fn_ret_ty(visitor, &function_declaration.output)
512 pub fn walk_fn_kind<V: Visitor>(visitor: &mut V, function_kind: FnKind) {
513 match function_kind {
514 FnKind::ItemFn(_, generics, _, _, _, _) => {
515 visitor.visit_generics(generics);
517 FnKind::Method(_, ref sig, _) => {
518 visitor.visit_generics(&sig.generics);
520 FnKind::Closure => {}
524 pub fn walk_fn<V>(visitor: &mut V, kind: FnKind, declaration: &FnDecl, body: &Block, _span: Span)
527 walk_fn_decl(visitor, declaration);
528 walk_fn_kind(visitor, kind);
529 visitor.visit_block(body)
532 pub fn walk_trait_item<V: Visitor>(visitor: &mut V, trait_item: &TraitItem) {
533 visitor.visit_ident(trait_item.span, trait_item.ident);
534 walk_list!(visitor, visit_attribute, &trait_item.attrs);
535 match trait_item.node {
536 TraitItemKind::Const(ref ty, ref default) => {
537 visitor.visit_ty(ty);
538 walk_list!(visitor, visit_expr, default);
540 TraitItemKind::Method(ref sig, None) => {
541 visitor.visit_generics(&sig.generics);
542 walk_fn_decl(visitor, &sig.decl);
544 TraitItemKind::Method(ref sig, Some(ref body)) => {
545 visitor.visit_fn(FnKind::Method(trait_item.ident, sig, None), &sig.decl,
546 body, trait_item.span, trait_item.id);
548 TraitItemKind::Type(ref bounds, ref default) => {
549 walk_list!(visitor, visit_ty_param_bound, bounds);
550 walk_list!(visitor, visit_ty, default);
552 TraitItemKind::Macro(ref mac) => {
553 visitor.visit_mac(mac);
558 pub fn walk_impl_item<V: Visitor>(visitor: &mut V, impl_item: &ImplItem) {
559 visitor.visit_vis(&impl_item.vis);
560 visitor.visit_ident(impl_item.span, impl_item.ident);
561 walk_list!(visitor, visit_attribute, &impl_item.attrs);
562 match impl_item.node {
563 ImplItemKind::Const(ref ty, ref expr) => {
564 visitor.visit_ty(ty);
565 visitor.visit_expr(expr);
567 ImplItemKind::Method(ref sig, ref body) => {
568 visitor.visit_fn(FnKind::Method(impl_item.ident, sig, Some(&impl_item.vis)), &sig.decl,
569 body, impl_item.span, impl_item.id);
571 ImplItemKind::Type(ref ty) => {
572 visitor.visit_ty(ty);
574 ImplItemKind::Macro(ref mac) => {
575 visitor.visit_mac(mac);
580 pub fn walk_struct_def<V: Visitor>(visitor: &mut V, struct_definition: &VariantData) {
581 walk_list!(visitor, visit_struct_field, struct_definition.fields());
584 pub fn walk_struct_field<V: Visitor>(visitor: &mut V, struct_field: &StructField) {
585 visitor.visit_vis(&struct_field.vis);
586 walk_opt_ident(visitor, struct_field.span, struct_field.ident);
587 visitor.visit_ty(&struct_field.ty);
588 walk_list!(visitor, visit_attribute, &struct_field.attrs);
591 pub fn walk_block<V: Visitor>(visitor: &mut V, block: &Block) {
592 walk_list!(visitor, visit_stmt, &block.stmts);
595 pub fn walk_stmt<V: Visitor>(visitor: &mut V, statement: &Stmt) {
596 match statement.node {
597 StmtKind::Local(ref local) => visitor.visit_local(local),
598 StmtKind::Item(ref item) => visitor.visit_item(item),
599 StmtKind::Expr(ref expression) | StmtKind::Semi(ref expression) => {
600 visitor.visit_expr(expression)
602 StmtKind::Mac(ref mac) => {
603 let (ref mac, _, ref attrs) = **mac;
604 visitor.visit_mac(mac);
605 for attr in attrs.iter() {
606 visitor.visit_attribute(attr);
612 pub fn walk_mac<V: Visitor>(_: &mut V, _: &Mac) {
616 pub fn walk_expr<V: Visitor>(visitor: &mut V, expression: &Expr) {
617 for attr in expression.attrs.iter() {
618 visitor.visit_attribute(attr);
620 match expression.node {
621 ExprKind::Box(ref subexpression) => {
622 visitor.visit_expr(subexpression)
624 ExprKind::InPlace(ref place, ref subexpression) => {
625 visitor.visit_expr(place);
626 visitor.visit_expr(subexpression)
628 ExprKind::Vec(ref subexpressions) => {
629 walk_list!(visitor, visit_expr, subexpressions);
631 ExprKind::Repeat(ref element, ref count) => {
632 visitor.visit_expr(element);
633 visitor.visit_expr(count)
635 ExprKind::Struct(ref path, ref fields, ref optional_base) => {
636 visitor.visit_path(path, expression.id);
637 for field in fields {
638 visitor.visit_ident(field.ident.span, field.ident.node);
639 visitor.visit_expr(&field.expr)
641 walk_list!(visitor, visit_expr, optional_base);
643 ExprKind::Tup(ref subexpressions) => {
644 walk_list!(visitor, visit_expr, subexpressions);
646 ExprKind::Call(ref callee_expression, ref arguments) => {
647 walk_list!(visitor, visit_expr, arguments);
648 visitor.visit_expr(callee_expression)
650 ExprKind::MethodCall(ref ident, ref types, ref arguments) => {
651 visitor.visit_ident(ident.span, ident.node);
652 walk_list!(visitor, visit_expr, arguments);
653 walk_list!(visitor, visit_ty, types);
655 ExprKind::Binary(_, ref left_expression, ref right_expression) => {
656 visitor.visit_expr(left_expression);
657 visitor.visit_expr(right_expression)
659 ExprKind::AddrOf(_, ref subexpression) | ExprKind::Unary(_, ref subexpression) => {
660 visitor.visit_expr(subexpression)
662 ExprKind::Lit(_) => {}
663 ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => {
664 visitor.visit_expr(subexpression);
665 visitor.visit_ty(typ)
667 ExprKind::If(ref head_expression, ref if_block, ref optional_else) => {
668 visitor.visit_expr(head_expression);
669 visitor.visit_block(if_block);
670 walk_list!(visitor, visit_expr, optional_else);
672 ExprKind::While(ref subexpression, ref block, ref opt_sp_ident) => {
673 visitor.visit_expr(subexpression);
674 visitor.visit_block(block);
675 walk_opt_sp_ident(visitor, opt_sp_ident);
677 ExprKind::IfLet(ref pattern, ref subexpression, ref if_block, ref optional_else) => {
678 visitor.visit_pat(pattern);
679 visitor.visit_expr(subexpression);
680 visitor.visit_block(if_block);
681 walk_list!(visitor, visit_expr, optional_else);
683 ExprKind::WhileLet(ref pattern, ref subexpression, ref block, ref opt_sp_ident) => {
684 visitor.visit_pat(pattern);
685 visitor.visit_expr(subexpression);
686 visitor.visit_block(block);
687 walk_opt_sp_ident(visitor, opt_sp_ident);
689 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, ref opt_sp_ident) => {
690 visitor.visit_pat(pattern);
691 visitor.visit_expr(subexpression);
692 visitor.visit_block(block);
693 walk_opt_sp_ident(visitor, opt_sp_ident);
695 ExprKind::Loop(ref block, ref opt_sp_ident) => {
696 visitor.visit_block(block);
697 walk_opt_sp_ident(visitor, opt_sp_ident);
699 ExprKind::Match(ref subexpression, ref arms) => {
700 visitor.visit_expr(subexpression);
701 walk_list!(visitor, visit_arm, arms);
703 ExprKind::Closure(_, ref function_declaration, ref body, _decl_span) => {
704 visitor.visit_fn(FnKind::Closure,
705 function_declaration,
710 ExprKind::Block(ref block) => visitor.visit_block(block),
711 ExprKind::Assign(ref left_hand_expression, ref right_hand_expression) => {
712 visitor.visit_expr(right_hand_expression);
713 visitor.visit_expr(left_hand_expression)
715 ExprKind::AssignOp(_, ref left_expression, ref right_expression) => {
716 visitor.visit_expr(right_expression);
717 visitor.visit_expr(left_expression)
719 ExprKind::Field(ref subexpression, ref ident) => {
720 visitor.visit_expr(subexpression);
721 visitor.visit_ident(ident.span, ident.node);
723 ExprKind::TupField(ref subexpression, _) => {
724 visitor.visit_expr(subexpression);
726 ExprKind::Index(ref main_expression, ref index_expression) => {
727 visitor.visit_expr(main_expression);
728 visitor.visit_expr(index_expression)
730 ExprKind::Range(ref start, ref end, _) => {
731 walk_list!(visitor, visit_expr, start);
732 walk_list!(visitor, visit_expr, end);
734 ExprKind::Path(ref maybe_qself, ref path) => {
735 if let Some(ref qself) = *maybe_qself {
736 visitor.visit_ty(&qself.ty);
738 visitor.visit_path(path, expression.id)
740 ExprKind::Break(ref opt_sp_ident) | ExprKind::Continue(ref opt_sp_ident) => {
741 walk_opt_sp_ident(visitor, opt_sp_ident);
743 ExprKind::Ret(ref optional_expression) => {
744 walk_list!(visitor, visit_expr, optional_expression);
746 ExprKind::Mac(ref mac) => visitor.visit_mac(mac),
747 ExprKind::Paren(ref subexpression) => {
748 visitor.visit_expr(subexpression)
750 ExprKind::InlineAsm(ref ia) => {
751 for &(_, ref input) in &ia.inputs {
752 visitor.visit_expr(&input)
754 for output in &ia.outputs {
755 visitor.visit_expr(&output.expr)
758 ExprKind::Try(ref subexpression) => {
759 visitor.visit_expr(subexpression)
763 visitor.visit_expr_post(expression)
766 pub fn walk_arm<V: Visitor>(visitor: &mut V, arm: &Arm) {
767 walk_list!(visitor, visit_pat, &arm.pats);
768 walk_list!(visitor, visit_expr, &arm.guard);
769 visitor.visit_expr(&arm.body);
770 walk_list!(visitor, visit_attribute, &arm.attrs);
773 pub fn walk_vis<V: Visitor>(visitor: &mut V, vis: &Visibility) {
774 if let Visibility::Restricted { ref path, id } = *vis {
775 visitor.visit_path(path, id);