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.
30 #[derive(Copy, Clone, PartialEq, Eq)]
32 /// fn foo() or extern "Abi" fn foo()
33 ItemFn(Ident, &'a Generics, Unsafety, Constness, Abi, Visibility),
36 Method(Ident, &'a MethodSig, Option<Visibility>),
42 /// Each method of the Visitor trait is a hook to be potentially
43 /// overridden. Each method's default implementation recursively visits
44 /// the substructure of the input via the corresponding `walk` method;
45 /// e.g. the `visit_mod` method by default calls `visit::walk_mod`.
47 /// If you want to ensure that your code handles every variant
48 /// explicitly, you need to override each method. (And you also need
49 /// to monitor future changes to `Visitor` in case a new method with a
50 /// new default implementation gets introduced.)
51 pub trait Visitor<'v> : Sized {
52 fn visit_name(&mut self, _span: Span, _name: Name) {
55 fn visit_ident(&mut self, span: Span, ident: Ident) {
56 walk_ident(self, span, ident);
58 fn visit_mod(&mut self, m: &'v Mod, _s: Span, _n: NodeId) { walk_mod(self, m) }
59 fn visit_foreign_item(&mut self, i: &'v ForeignItem) { walk_foreign_item(self, i) }
60 fn visit_item(&mut self, i: &'v Item) { walk_item(self, i) }
61 fn visit_local(&mut self, l: &'v Local) { walk_local(self, l) }
62 fn visit_block(&mut self, b: &'v Block) { walk_block(self, b) }
63 fn visit_stmt(&mut self, s: &'v Stmt) { walk_stmt(self, s) }
64 fn visit_arm(&mut self, a: &'v Arm) { walk_arm(self, a) }
65 fn visit_pat(&mut self, p: &'v Pat) { walk_pat(self, p) }
66 fn visit_decl(&mut self, d: &'v Decl) { walk_decl(self, d) }
67 fn visit_expr(&mut self, ex: &'v Expr) { walk_expr(self, ex) }
68 fn visit_expr_post(&mut self, _ex: &'v Expr) { }
69 fn visit_ty(&mut self, t: &'v Ty) { walk_ty(self, t) }
70 fn visit_generics(&mut self, g: &'v Generics) { walk_generics(self, g) }
71 fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl, b: &'v Block, s: Span, _: NodeId) {
72 walk_fn(self, fk, fd, b, s)
74 fn visit_trait_item(&mut self, ti: &'v TraitItem) { walk_trait_item(self, ti) }
75 fn visit_impl_item(&mut self, ii: &'v ImplItem) { walk_impl_item(self, ii) }
76 fn visit_trait_ref(&mut self, t: &'v TraitRef) { walk_trait_ref(self, t) }
77 fn visit_ty_param_bound(&mut self, bounds: &'v TyParamBound) {
78 walk_ty_param_bound(self, bounds)
80 fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef, m: &'v TraitBoundModifier) {
81 walk_poly_trait_ref(self, t, m)
83 fn visit_variant_data(&mut self, s: &'v VariantData, _: Ident,
84 _: &'v Generics, _: NodeId, _: Span) {
85 walk_struct_def(self, s)
87 fn visit_struct_field(&mut self, s: &'v StructField) { walk_struct_field(self, s) }
88 fn visit_enum_def(&mut self, enum_definition: &'v EnumDef,
89 generics: &'v Generics, item_id: NodeId, _: Span) {
90 walk_enum_def(self, enum_definition, generics, item_id)
92 fn visit_variant(&mut self, v: &'v Variant, g: &'v Generics, item_id: NodeId) {
93 walk_variant(self, v, g, item_id)
95 fn visit_lifetime(&mut self, lifetime: &'v Lifetime) {
96 walk_lifetime(self, lifetime)
98 fn visit_lifetime_def(&mut self, lifetime: &'v LifetimeDef) {
99 walk_lifetime_def(self, lifetime)
101 fn visit_explicit_self(&mut self, es: &'v ExplicitSelf) {
102 walk_explicit_self(self, es)
104 fn visit_mac(&mut self, _mac: &'v 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: &'v Path, _id: NodeId) {
113 walk_path(self, path)
115 fn visit_path_list_item(&mut self, prefix: &'v Path, item: &'v PathListItem) {
116 walk_path_list_item(self, prefix, item)
118 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment) {
119 walk_path_segment(self, path_span, path_segment)
121 fn visit_path_parameters(&mut self, path_span: Span, path_parameters: &'v PathParameters) {
122 walk_path_parameters(self, path_span, path_parameters)
124 fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding) {
125 walk_assoc_type_binding(self, type_binding)
127 fn visit_attribute(&mut self, _attr: &'v Attribute) {}
128 fn visit_macro_def(&mut self, macro_def: &'v MacroDef) {
129 walk_macro_def(self, macro_def)
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, V: Visitor<'v>>(visitor: &mut V, span: Span, opt_name: Option<Name>) {
148 for name in opt_name {
149 visitor.visit_name(span, name);
153 pub fn walk_opt_ident<'v, V: Visitor<'v>>(visitor: &mut V, span: Span, opt_ident: Option<Ident>) {
154 for ident in opt_ident {
155 visitor.visit_ident(span, ident);
159 pub fn walk_ident<'v, V: Visitor<'v>>(visitor: &mut V, span: Span, ident: Ident) {
160 visitor.visit_name(span, ident.name);
163 pub fn walk_crate<'v, V: Visitor<'v>>(visitor: &mut V, krate: &'v Crate) {
164 visitor.visit_mod(&krate.module, krate.span, CRATE_NODE_ID);
165 walk_list!(visitor, visit_attribute, &krate.attrs);
166 walk_list!(visitor, visit_macro_def, &krate.exported_macros);
169 pub fn walk_macro_def<'v, V: Visitor<'v>>(visitor: &mut V, macro_def: &'v MacroDef) {
170 visitor.visit_ident(macro_def.span, macro_def.ident);
171 walk_opt_ident(visitor, macro_def.span, macro_def.imported_from);
172 walk_list!(visitor, visit_attribute, ¯o_def.attrs);
175 pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod) {
176 walk_list!(visitor, visit_item, &module.items);
179 pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local) {
180 visitor.visit_pat(&local.pat);
181 walk_list!(visitor, visit_ty, &local.ty);
182 walk_list!(visitor, visit_expr, &local.init);
185 pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) {
186 visitor.visit_name(lifetime.span, lifetime.name);
189 pub fn walk_lifetime_def<'v, V: Visitor<'v>>(visitor: &mut V,
190 lifetime_def: &'v LifetimeDef) {
191 visitor.visit_lifetime(&lifetime_def.lifetime);
192 walk_list!(visitor, visit_lifetime, &lifetime_def.bounds);
195 pub fn walk_explicit_self<'v, V: Visitor<'v>>(visitor: &mut V,
196 explicit_self: &'v ExplicitSelf) {
197 match explicit_self.node {
199 SelfValue(ident) => {
200 visitor.visit_ident(explicit_self.span, ident)
202 SelfRegion(ref opt_lifetime, _, ident) => {
203 visitor.visit_ident(explicit_self.span, ident);
204 walk_list!(visitor, visit_lifetime, opt_lifetime);
206 SelfExplicit(ref typ, ident) => {
207 visitor.visit_ident(explicit_self.span, ident);
208 visitor.visit_ty(typ)
213 pub fn walk_poly_trait_ref<'v, V>(visitor: &mut V,
214 trait_ref: &'v PolyTraitRef,
215 _modifier: &'v TraitBoundModifier)
218 walk_list!(visitor, visit_lifetime_def, &trait_ref.bound_lifetimes);
219 visitor.visit_trait_ref(&trait_ref.trait_ref);
222 pub fn walk_trait_ref<'v,V>(visitor: &mut V,
223 trait_ref: &'v TraitRef)
226 visitor.visit_path(&trait_ref.path, trait_ref.ref_id)
229 pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {
230 visitor.visit_ident(item.span, item.ident);
232 ItemExternCrate(opt_name) => {
233 walk_opt_name(visitor, item.span, opt_name)
237 ViewPathSimple(ident, ref path) => {
238 visitor.visit_ident(vp.span, ident);
239 visitor.visit_path(path, item.id);
241 ViewPathGlob(ref path) => {
242 visitor.visit_path(path, item.id);
244 ViewPathList(ref prefix, ref list) => {
245 if !list.is_empty() {
247 visitor.visit_path_list_item(prefix, item)
250 visitor.visit_path(prefix, item.id);
255 ItemStatic(ref typ, _, ref expr) |
256 ItemConst(ref typ, ref expr) => {
257 visitor.visit_ty(typ);
258 visitor.visit_expr(expr);
260 ItemFn(ref declaration, unsafety, constness, abi, ref generics, ref body) => {
261 visitor.visit_fn(FnKind::ItemFn(item.ident, generics, unsafety,
262 constness, abi, item.vis),
268 ItemMod(ref module) => {
269 visitor.visit_mod(module, item.span, item.id)
271 ItemForeignMod(ref foreign_module) => {
272 walk_list!(visitor, visit_foreign_item, &foreign_module.items);
274 ItemTy(ref typ, ref type_parameters) => {
275 visitor.visit_ty(typ);
276 visitor.visit_generics(type_parameters)
278 ItemEnum(ref enum_definition, ref type_parameters) => {
279 visitor.visit_generics(type_parameters);
280 visitor.visit_enum_def(enum_definition, type_parameters, item.id, item.span)
282 ItemDefaultImpl(_, ref trait_ref) => {
283 visitor.visit_trait_ref(trait_ref)
287 ref opt_trait_reference,
290 visitor.visit_generics(type_parameters);
291 walk_list!(visitor, visit_trait_ref, opt_trait_reference);
292 visitor.visit_ty(typ);
293 walk_list!(visitor, visit_impl_item, impl_items);
295 ItemStruct(ref struct_definition, ref generics) => {
296 visitor.visit_generics(generics);
297 visitor.visit_variant_data(struct_definition, item.ident,
298 generics, item.id, item.span);
300 ItemTrait(_, ref generics, ref bounds, ref methods) => {
301 visitor.visit_generics(generics);
302 walk_list!(visitor, visit_ty_param_bound, bounds);
303 walk_list!(visitor, visit_trait_item, methods);
305 ItemMac(ref mac) => visitor.visit_mac(mac),
307 walk_list!(visitor, visit_attribute, &item.attrs);
310 pub fn walk_enum_def<'v, V: Visitor<'v>>(visitor: &mut V,
311 enum_definition: &'v EnumDef,
312 generics: &'v Generics,
314 walk_list!(visitor, visit_variant, &enum_definition.variants, generics, item_id);
317 pub fn walk_variant<'v, V: Visitor<'v>>(visitor: &mut V,
318 variant: &'v Variant,
319 generics: &'v Generics,
321 visitor.visit_ident(variant.span, variant.node.name);
322 visitor.visit_variant_data(&variant.node.data, variant.node.name,
323 generics, item_id, variant.span);
324 walk_list!(visitor, visit_expr, &variant.node.disr_expr);
325 walk_list!(visitor, visit_attribute, &variant.node.attrs);
328 pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty) {
330 TyVec(ref ty) | TyParen(ref ty) => {
333 TyPtr(ref mutable_type) => {
334 visitor.visit_ty(&mutable_type.ty)
336 TyRptr(ref opt_lifetime, ref mutable_type) => {
337 walk_list!(visitor, visit_lifetime, opt_lifetime);
338 visitor.visit_ty(&mutable_type.ty)
340 TyTup(ref tuple_element_types) => {
341 walk_list!(visitor, visit_ty, tuple_element_types);
343 TyBareFn(ref function_declaration) => {
344 walk_fn_decl(visitor, &function_declaration.decl);
345 walk_list!(visitor, visit_lifetime_def, &function_declaration.lifetimes);
347 TyPath(ref maybe_qself, ref path) => {
348 if let Some(ref qself) = *maybe_qself {
349 visitor.visit_ty(&qself.ty);
351 visitor.visit_path(path, typ.id);
353 TyObjectSum(ref ty, ref bounds) => {
354 visitor.visit_ty(ty);
355 walk_list!(visitor, visit_ty_param_bound, bounds);
357 TyFixedLengthVec(ref ty, ref expression) => {
358 visitor.visit_ty(ty);
359 visitor.visit_expr(expression)
361 TyPolyTraitRef(ref bounds) => {
362 walk_list!(visitor, visit_ty_param_bound, bounds);
364 TyTypeof(ref expression) => {
365 visitor.visit_expr(expression)
369 visitor.visit_mac(mac)
374 pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path) {
375 for segment in &path.segments {
376 visitor.visit_path_segment(path.span, segment);
380 pub fn walk_path_list_item<'v, V: Visitor<'v>>(visitor: &mut V, prefix: &'v Path,
381 item: &'v PathListItem) {
382 for segment in &prefix.segments {
383 visitor.visit_path_segment(prefix.span, segment);
386 walk_opt_ident(visitor, item.span, item.node.name());
387 walk_opt_ident(visitor, item.span, item.node.rename());
390 pub fn walk_path_segment<'v, V: Visitor<'v>>(visitor: &mut V,
392 segment: &'v PathSegment) {
393 visitor.visit_ident(path_span, segment.identifier);
394 visitor.visit_path_parameters(path_span, &segment.parameters);
397 pub fn walk_path_parameters<'v, V: Visitor<'v>>(visitor: &mut V,
399 path_parameters: &'v PathParameters) {
400 match *path_parameters {
401 AngleBracketedParameters(ref data) => {
402 walk_list!(visitor, visit_ty, &data.types);
403 walk_list!(visitor, visit_lifetime, &data.lifetimes);
404 walk_list!(visitor, visit_assoc_type_binding, &data.bindings);
406 ParenthesizedParameters(ref data) => {
407 walk_list!(visitor, visit_ty, &data.inputs);
408 walk_list!(visitor, visit_ty, &data.output);
413 pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(visitor: &mut V,
414 type_binding: &'v TypeBinding) {
415 visitor.visit_ident(type_binding.span, type_binding.ident);
416 visitor.visit_ty(&type_binding.ty);
419 pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat) {
421 PatEnum(ref path, ref opt_children) => {
422 visitor.visit_path(path, pattern.id);
423 if let Some(ref children) = *opt_children {
424 walk_list!(visitor, visit_pat, children);
427 PatQPath(ref qself, ref path) => {
428 visitor.visit_ty(&qself.ty);
429 visitor.visit_path(path, pattern.id)
431 PatStruct(ref path, ref fields, _) => {
432 visitor.visit_path(path, pattern.id);
433 for field in fields {
434 visitor.visit_ident(field.span, field.node.ident);
435 visitor.visit_pat(&field.node.pat)
438 PatTup(ref tuple_elements) => {
439 walk_list!(visitor, visit_pat, tuple_elements);
441 PatBox(ref subpattern) |
442 PatRegion(ref subpattern, _) => {
443 visitor.visit_pat(subpattern)
445 PatIdent(_, ref pth1, ref optional_subpattern) => {
446 visitor.visit_ident(pth1.span, pth1.node);
447 walk_list!(visitor, visit_pat, optional_subpattern);
449 PatLit(ref expression) => visitor.visit_expr(expression),
450 PatRange(ref lower_bound, ref upper_bound) => {
451 visitor.visit_expr(lower_bound);
452 visitor.visit_expr(upper_bound)
455 PatVec(ref prepatterns, ref slice_pattern, ref postpatterns) => {
456 walk_list!(visitor, visit_pat, prepatterns);
457 walk_list!(visitor, visit_pat, slice_pattern);
458 walk_list!(visitor, visit_pat, postpatterns);
460 PatMac(ref mac) => visitor.visit_mac(mac),
464 pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V,
465 foreign_item: &'v ForeignItem) {
466 visitor.visit_ident(foreign_item.span, foreign_item.ident);
468 match foreign_item.node {
469 ForeignItemFn(ref function_declaration, ref generics) => {
470 walk_fn_decl(visitor, function_declaration);
471 visitor.visit_generics(generics)
473 ForeignItemStatic(ref typ, _) => visitor.visit_ty(typ),
476 walk_list!(visitor, visit_attribute, &foreign_item.attrs);
479 pub fn walk_ty_param_bound<'v, V: Visitor<'v>>(visitor: &mut V,
480 bound: &'v TyParamBound) {
482 TraitTyParamBound(ref typ, ref modifier) => {
483 visitor.visit_poly_trait_ref(typ, modifier);
485 RegionTyParamBound(ref lifetime) => {
486 visitor.visit_lifetime(lifetime);
491 pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics) {
492 for param in &generics.ty_params {
493 visitor.visit_ident(param.span, param.ident);
494 walk_list!(visitor, visit_ty_param_bound, ¶m.bounds);
495 walk_list!(visitor, visit_ty, ¶m.default);
497 walk_list!(visitor, visit_lifetime_def, &generics.lifetimes);
498 for predicate in &generics.where_clause.predicates {
500 WherePredicate::BoundPredicate(WhereBoundPredicate{ref bounded_ty,
504 visitor.visit_ty(bounded_ty);
505 walk_list!(visitor, visit_ty_param_bound, bounds);
506 walk_list!(visitor, visit_lifetime_def, bound_lifetimes);
508 WherePredicate::RegionPredicate(WhereRegionPredicate{ref lifetime,
511 visitor.visit_lifetime(lifetime);
512 walk_list!(visitor, visit_lifetime, bounds);
514 WherePredicate::EqPredicate(WhereEqPredicate{id,
518 visitor.visit_path(path, id);
519 visitor.visit_ty(ty);
525 pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FunctionRetTy) {
526 if let Return(ref output_ty) = *ret_ty {
527 visitor.visit_ty(output_ty)
531 pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl) {
532 for argument in &function_declaration.inputs {
533 visitor.visit_pat(&argument.pat);
534 visitor.visit_ty(&argument.ty)
536 walk_fn_ret_ty(visitor, &function_declaration.output)
539 pub fn walk_fn_kind<'v, V: Visitor<'v>>(visitor: &mut V,
540 function_kind: FnKind<'v>) {
541 match function_kind {
542 FnKind::ItemFn(_, generics, _, _, _, _) => {
543 visitor.visit_generics(generics);
545 FnKind::Method(_, sig, _) => {
546 visitor.visit_generics(&sig.generics);
547 visitor.visit_explicit_self(&sig.explicit_self);
549 FnKind::Closure => {}
553 pub fn walk_fn<'v, V: Visitor<'v>>(visitor: &mut V,
554 function_kind: FnKind<'v>,
555 function_declaration: &'v FnDecl,
556 function_body: &'v Block,
558 walk_fn_decl(visitor, function_declaration);
559 walk_fn_kind(visitor, function_kind);
560 visitor.visit_block(function_body)
563 pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem) {
564 visitor.visit_ident(trait_item.span, trait_item.ident);
565 walk_list!(visitor, visit_attribute, &trait_item.attrs);
566 match trait_item.node {
567 ConstTraitItem(ref ty, ref default) => {
568 visitor.visit_ty(ty);
569 walk_list!(visitor, visit_expr, default);
571 MethodTraitItem(ref sig, None) => {
572 visitor.visit_explicit_self(&sig.explicit_self);
573 visitor.visit_generics(&sig.generics);
574 walk_fn_decl(visitor, &sig.decl);
576 MethodTraitItem(ref sig, Some(ref body)) => {
577 visitor.visit_fn(FnKind::Method(trait_item.ident, sig, None), &sig.decl,
578 body, trait_item.span, trait_item.id);
580 TypeTraitItem(ref bounds, ref default) => {
581 walk_list!(visitor, visit_ty_param_bound, bounds);
582 walk_list!(visitor, visit_ty, default);
587 pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem) {
588 visitor.visit_ident(impl_item.span, impl_item.ident);
589 walk_list!(visitor, visit_attribute, &impl_item.attrs);
590 match impl_item.node {
591 ImplItemKind::Const(ref ty, ref expr) => {
592 visitor.visit_ty(ty);
593 visitor.visit_expr(expr);
595 ImplItemKind::Method(ref sig, ref body) => {
596 visitor.visit_fn(FnKind::Method(impl_item.ident, sig, Some(impl_item.vis)), &sig.decl,
597 body, impl_item.span, impl_item.id);
599 ImplItemKind::Type(ref ty) => {
600 visitor.visit_ty(ty);
602 ImplItemKind::Macro(ref mac) => {
603 visitor.visit_mac(mac);
608 pub fn walk_struct_def<'v, V: Visitor<'v>>(visitor: &mut V,
609 struct_definition: &'v VariantData) {
610 walk_list!(visitor, visit_struct_field, struct_definition.fields());
613 pub fn walk_struct_field<'v, V: Visitor<'v>>(visitor: &mut V,
614 struct_field: &'v StructField) {
615 walk_opt_ident(visitor, struct_field.span, struct_field.node.ident());
616 visitor.visit_ty(&struct_field.node.ty);
617 walk_list!(visitor, visit_attribute, &struct_field.node.attrs);
620 pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block) {
621 walk_list!(visitor, visit_stmt, &block.stmts);
622 walk_list!(visitor, visit_expr, &block.expr);
625 pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt) {
626 match statement.node {
627 StmtDecl(ref declaration, _) => visitor.visit_decl(declaration),
628 StmtExpr(ref expression, _) | StmtSemi(ref expression, _) => {
629 visitor.visit_expr(expression)
631 StmtMac(ref mac, _) => visitor.visit_mac(mac),
635 pub fn walk_decl<'v, V: Visitor<'v>>(visitor: &mut V, declaration: &'v Decl) {
636 match declaration.node {
637 DeclLocal(ref local) => visitor.visit_local(local),
638 DeclItem(ref item) => visitor.visit_item(item),
642 pub fn walk_mac<'v, V: Visitor<'v>>(_: &mut V, _: &'v Mac) {
646 pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
647 match expression.node {
648 ExprBox(ref subexpression) => {
649 visitor.visit_expr(subexpression)
651 ExprInPlace(ref place, ref subexpression) => {
652 visitor.visit_expr(place);
653 visitor.visit_expr(subexpression)
655 ExprVec(ref subexpressions) => {
656 walk_list!(visitor, visit_expr, subexpressions);
658 ExprRepeat(ref element, ref count) => {
659 visitor.visit_expr(element);
660 visitor.visit_expr(count)
662 ExprStruct(ref path, ref fields, ref optional_base) => {
663 visitor.visit_path(path, expression.id);
664 for field in fields {
665 visitor.visit_ident(field.ident.span, field.ident.node);
666 visitor.visit_expr(&field.expr)
668 walk_list!(visitor, visit_expr, optional_base);
670 ExprTup(ref subexpressions) => {
671 walk_list!(visitor, visit_expr, subexpressions);
673 ExprCall(ref callee_expression, ref arguments) => {
674 walk_list!(visitor, visit_expr, arguments);
675 visitor.visit_expr(callee_expression)
677 ExprMethodCall(ref ident, ref types, ref arguments) => {
678 visitor.visit_ident(ident.span, ident.node);
679 walk_list!(visitor, visit_expr, arguments);
680 walk_list!(visitor, visit_ty, types);
682 ExprBinary(_, ref left_expression, ref right_expression) => {
683 visitor.visit_expr(left_expression);
684 visitor.visit_expr(right_expression)
686 ExprAddrOf(_, ref subexpression) | ExprUnary(_, ref subexpression) => {
687 visitor.visit_expr(subexpression)
690 ExprCast(ref subexpression, ref typ) => {
691 visitor.visit_expr(subexpression);
692 visitor.visit_ty(typ)
694 ExprIf(ref head_expression, ref if_block, ref optional_else) => {
695 visitor.visit_expr(head_expression);
696 visitor.visit_block(if_block);
697 walk_list!(visitor, visit_expr, optional_else);
699 ExprWhile(ref subexpression, ref block, opt_ident) => {
700 visitor.visit_expr(subexpression);
701 visitor.visit_block(block);
702 walk_opt_ident(visitor, expression.span, opt_ident)
704 ExprIfLet(ref pattern, ref subexpression, ref if_block, ref optional_else) => {
705 visitor.visit_pat(pattern);
706 visitor.visit_expr(subexpression);
707 visitor.visit_block(if_block);
708 walk_list!(visitor, visit_expr, optional_else);
710 ExprWhileLet(ref pattern, ref subexpression, ref block, opt_ident) => {
711 visitor.visit_pat(pattern);
712 visitor.visit_expr(subexpression);
713 visitor.visit_block(block);
714 walk_opt_ident(visitor, expression.span, opt_ident)
716 ExprForLoop(ref pattern, ref subexpression, ref block, opt_ident) => {
717 visitor.visit_pat(pattern);
718 visitor.visit_expr(subexpression);
719 visitor.visit_block(block);
720 walk_opt_ident(visitor, expression.span, opt_ident)
722 ExprLoop(ref block, opt_ident) => {
723 visitor.visit_block(block);
724 walk_opt_ident(visitor, expression.span, opt_ident)
726 ExprMatch(ref subexpression, ref arms) => {
727 visitor.visit_expr(subexpression);
728 walk_list!(visitor, visit_arm, arms);
730 ExprClosure(_, ref function_declaration, ref body) => {
731 visitor.visit_fn(FnKind::Closure,
732 function_declaration,
737 ExprBlock(ref block) => visitor.visit_block(block),
738 ExprAssign(ref left_hand_expression, ref right_hand_expression) => {
739 visitor.visit_expr(right_hand_expression);
740 visitor.visit_expr(left_hand_expression)
742 ExprAssignOp(_, ref left_expression, ref right_expression) => {
743 visitor.visit_expr(right_expression);
744 visitor.visit_expr(left_expression)
746 ExprField(ref subexpression, ref ident) => {
747 visitor.visit_expr(subexpression);
748 visitor.visit_ident(ident.span, ident.node);
750 ExprTupField(ref subexpression, _) => {
751 visitor.visit_expr(subexpression);
753 ExprIndex(ref main_expression, ref index_expression) => {
754 visitor.visit_expr(main_expression);
755 visitor.visit_expr(index_expression)
757 ExprRange(ref start, ref end) => {
758 walk_list!(visitor, visit_expr, start);
759 walk_list!(visitor, visit_expr, end);
761 ExprPath(ref maybe_qself, ref path) => {
762 if let Some(ref qself) = *maybe_qself {
763 visitor.visit_ty(&qself.ty);
765 visitor.visit_path(path, expression.id)
767 ExprBreak(ref opt_sp_ident) | ExprAgain(ref opt_sp_ident) => {
768 for sp_ident in opt_sp_ident {
769 visitor.visit_ident(sp_ident.span, sp_ident.node);
772 ExprRet(ref optional_expression) => {
773 walk_list!(visitor, visit_expr, optional_expression);
775 ExprMac(ref mac) => visitor.visit_mac(mac),
776 ExprParen(ref subexpression) => {
777 visitor.visit_expr(subexpression)
779 ExprInlineAsm(ref ia) => {
780 for &(_, ref input) in &ia.inputs {
781 visitor.visit_expr(&input)
783 for &(_, ref output, _) in &ia.outputs {
784 visitor.visit_expr(&output)
789 visitor.visit_expr_post(expression)
792 pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm) {
793 walk_list!(visitor, visit_pat, &arm.pats);
794 walk_list!(visitor, visit_expr, &arm.guard);
795 visitor.visit_expr(&arm.body);
796 walk_list!(visitor, visit_attribute, &arm.attrs);