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 use tokenstream::ThinTokenStream;
32 #[derive(Copy, Clone, PartialEq, Eq)]
34 /// fn foo() or extern "Abi" fn foo()
35 ItemFn(Ident, &'a Generics, Unsafety, Spanned<Constness>, Abi, &'a Visibility, &'a Block),
38 Method(Ident, &'a MethodSig, Option<&'a Visibility>, &'a Block),
44 /// Each method of the Visitor trait is a hook to be potentially
45 /// overridden. Each method's default implementation recursively visits
46 /// the substructure of the input via the corresponding `walk` method;
47 /// e.g. the `visit_mod` method by default calls `visit::walk_mod`.
49 /// If you want to ensure that your code handles every variant
50 /// explicitly, you need to override each method. (And you also need
51 /// to monitor future changes to `Visitor` in case a new method with a
52 /// new default implementation gets introduced.)
53 pub trait Visitor<'ast>: Sized {
54 fn visit_name(&mut self, _span: Span, _name: Name) {
57 fn visit_ident(&mut self, span: Span, ident: Ident) {
58 walk_ident(self, span, ident);
60 fn visit_mod(&mut self, m: &'ast Mod, _s: Span, _attrs: &[Attribute], _n: NodeId) {
63 fn visit_foreign_item(&mut self, i: &'ast ForeignItem) { walk_foreign_item(self, i) }
64 fn visit_global_asm(&mut self, ga: &'ast GlobalAsm) { walk_global_asm(self, ga) }
65 fn visit_item(&mut self, i: &'ast Item) { walk_item(self, i) }
66 fn visit_local(&mut self, l: &'ast Local) { walk_local(self, l) }
67 fn visit_block(&mut self, b: &'ast Block) { walk_block(self, b) }
68 fn visit_stmt(&mut self, s: &'ast Stmt) { walk_stmt(self, s) }
69 fn visit_arm(&mut self, a: &'ast Arm) { walk_arm(self, a) }
70 fn visit_pat(&mut self, p: &'ast Pat) { walk_pat(self, p) }
71 fn visit_expr(&mut self, ex: &'ast Expr) { walk_expr(self, ex) }
72 fn visit_expr_post(&mut self, _ex: &'ast Expr) { }
73 fn visit_ty(&mut self, t: &'ast Ty) { walk_ty(self, t) }
74 fn visit_generics(&mut self, g: &'ast Generics) { walk_generics(self, g) }
75 fn visit_where_predicate(&mut self, p: &'ast WherePredicate) {
76 walk_where_predicate(self, p)
78 fn visit_fn(&mut self, fk: FnKind<'ast>, fd: &'ast FnDecl, s: Span, _: NodeId) {
79 walk_fn(self, fk, fd, s)
81 fn visit_trait_item(&mut self, ti: &'ast TraitItem) { walk_trait_item(self, ti) }
82 fn visit_impl_item(&mut self, ii: &'ast ImplItem) { walk_impl_item(self, ii) }
83 fn visit_trait_ref(&mut self, t: &'ast TraitRef) { walk_trait_ref(self, t) }
84 fn visit_ty_param_bound(&mut self, bounds: &'ast TyParamBound) {
85 walk_ty_param_bound(self, bounds)
87 fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef, m: &'ast TraitBoundModifier) {
88 walk_poly_trait_ref(self, t, m)
90 fn visit_variant_data(&mut self, s: &'ast VariantData, _: Ident,
91 _: &'ast Generics, _: NodeId, _: Span) {
92 walk_struct_def(self, s)
94 fn visit_struct_field(&mut self, s: &'ast StructField) { walk_struct_field(self, s) }
95 fn visit_enum_def(&mut self, enum_definition: &'ast EnumDef,
96 generics: &'ast Generics, item_id: NodeId, _: Span) {
97 walk_enum_def(self, enum_definition, generics, item_id)
99 fn visit_variant(&mut self, v: &'ast Variant, g: &'ast Generics, item_id: NodeId) {
100 walk_variant(self, v, g, item_id)
102 fn visit_lifetime(&mut self, lifetime: &'ast Lifetime) {
103 walk_lifetime(self, lifetime)
105 fn visit_lifetime_def(&mut self, lifetime: &'ast LifetimeDef) {
106 walk_lifetime_def(self, lifetime)
108 fn visit_mac(&mut self, _mac: &'ast Mac) {
109 panic!("visit_mac disabled by default");
110 // NB: see note about macros above.
111 // if you really want a visitor that
112 // works on macros, use this
113 // definition in your trait impl:
114 // visit::walk_mac(self, _mac)
116 fn visit_mac_def(&mut self, _mac: &'ast ThinTokenStream, _id: NodeId) {
119 fn visit_path(&mut self, path: &'ast Path, _id: NodeId) {
120 walk_path(self, path)
122 fn visit_path_list_item(&mut self, prefix: &'ast Path, item: &'ast PathListItem) {
123 walk_path_list_item(self, prefix, item)
125 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'ast PathSegment) {
126 walk_path_segment(self, path_span, path_segment)
128 fn visit_path_parameters(&mut self, path_span: Span, path_parameters: &'ast PathParameters) {
129 walk_path_parameters(self, path_span, path_parameters)
131 fn visit_assoc_type_binding(&mut self, type_binding: &'ast TypeBinding) {
132 walk_assoc_type_binding(self, type_binding)
134 fn visit_attribute(&mut self, _attr: &'ast Attribute) {}
135 fn visit_vis(&mut self, vis: &'ast Visibility) {
138 fn visit_fn_ret_ty(&mut self, ret_ty: &'ast FunctionRetTy) {
139 walk_fn_ret_ty(self, ret_ty)
144 macro_rules! walk_list {
145 ($visitor: expr, $method: ident, $list: expr) => {
147 $visitor.$method(elem)
150 ($visitor: expr, $method: ident, $list: expr, $($extra_args: expr),*) => {
152 $visitor.$method(elem, $($extra_args,)*)
157 pub fn walk_opt_name<'a, V: Visitor<'a>>(visitor: &mut V, span: Span, opt_name: Option<Name>) {
158 if let Some(name) = opt_name {
159 visitor.visit_name(span, name);
163 pub fn walk_opt_ident<'a, V: Visitor<'a>>(visitor: &mut V, span: Span, opt_ident: Option<Ident>) {
164 if let Some(ident) = opt_ident {
165 visitor.visit_ident(span, ident);
169 pub fn walk_opt_sp_ident<'a, V: Visitor<'a>>(visitor: &mut V,
170 opt_sp_ident: &Option<Spanned<Ident>>) {
171 if let Some(ref sp_ident) = *opt_sp_ident {
172 visitor.visit_ident(sp_ident.span, sp_ident.node);
176 pub fn walk_ident<'a, V: Visitor<'a>>(visitor: &mut V, span: Span, ident: Ident) {
177 visitor.visit_name(span, ident.name);
180 pub fn walk_crate<'a, V: Visitor<'a>>(visitor: &mut V, krate: &'a Crate) {
181 visitor.visit_mod(&krate.module, krate.span, &krate.attrs, CRATE_NODE_ID);
182 walk_list!(visitor, visit_attribute, &krate.attrs);
185 pub fn walk_mod<'a, V: Visitor<'a>>(visitor: &mut V, module: &'a Mod) {
186 walk_list!(visitor, visit_item, &module.items);
189 pub fn walk_local<'a, V: Visitor<'a>>(visitor: &mut V, local: &'a Local) {
190 for attr in local.attrs.iter() {
191 visitor.visit_attribute(attr);
193 visitor.visit_pat(&local.pat);
194 walk_list!(visitor, visit_ty, &local.ty);
195 walk_list!(visitor, visit_expr, &local.init);
198 pub fn walk_lifetime<'a, V: Visitor<'a>>(visitor: &mut V, lifetime: &'a Lifetime) {
199 visitor.visit_name(lifetime.span, lifetime.name);
202 pub fn walk_lifetime_def<'a, V: Visitor<'a>>(visitor: &mut V, lifetime_def: &'a LifetimeDef) {
203 visitor.visit_lifetime(&lifetime_def.lifetime);
204 walk_list!(visitor, visit_lifetime, &lifetime_def.bounds);
205 walk_list!(visitor, visit_attribute, &*lifetime_def.attrs);
208 pub fn walk_poly_trait_ref<'a, V>(visitor: &mut V,
209 trait_ref: &'a PolyTraitRef,
210 _: &TraitBoundModifier)
211 where V: Visitor<'a>,
213 walk_list!(visitor, visit_lifetime_def, &trait_ref.bound_lifetimes);
214 visitor.visit_trait_ref(&trait_ref.trait_ref);
217 pub fn walk_trait_ref<'a, V: Visitor<'a>>(visitor: &mut V, trait_ref: &'a TraitRef) {
218 visitor.visit_path(&trait_ref.path, trait_ref.ref_id)
221 pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
222 visitor.visit_vis(&item.vis);
223 visitor.visit_ident(item.span, item.ident);
225 ItemKind::ExternCrate(opt_name) => {
226 walk_opt_name(visitor, item.span, opt_name)
228 ItemKind::Use(ref vp) => {
230 ViewPathSimple(ident, ref path) => {
231 visitor.visit_ident(vp.span, ident);
232 visitor.visit_path(path, item.id);
234 ViewPathGlob(ref path) => {
235 visitor.visit_path(path, item.id);
237 ViewPathList(ref prefix, ref list) => {
238 visitor.visit_path(prefix, item.id);
240 visitor.visit_path_list_item(prefix, item)
245 ItemKind::Static(ref typ, _, ref expr) |
246 ItemKind::Const(ref typ, ref expr) => {
247 visitor.visit_ty(typ);
248 visitor.visit_expr(expr);
250 ItemKind::Fn(ref declaration, unsafety, constness, abi, ref generics, ref body) => {
251 visitor.visit_fn(FnKind::ItemFn(item.ident, generics, unsafety,
252 constness, abi, &item.vis, body),
257 ItemKind::Mod(ref module) => {
258 visitor.visit_mod(module, item.span, &item.attrs, item.id)
260 ItemKind::ForeignMod(ref foreign_module) => {
261 walk_list!(visitor, visit_foreign_item, &foreign_module.items);
263 ItemKind::GlobalAsm(ref ga) => visitor.visit_global_asm(ga),
264 ItemKind::Ty(ref typ, ref type_parameters) => {
265 visitor.visit_ty(typ);
266 visitor.visit_generics(type_parameters)
268 ItemKind::Enum(ref enum_definition, ref type_parameters) => {
269 visitor.visit_generics(type_parameters);
270 visitor.visit_enum_def(enum_definition, type_parameters, item.id, item.span)
272 ItemKind::DefaultImpl(_, ref trait_ref) => {
273 visitor.visit_trait_ref(trait_ref)
275 ItemKind::Impl(_, _, _,
277 ref opt_trait_reference,
280 visitor.visit_generics(type_parameters);
281 walk_list!(visitor, visit_trait_ref, opt_trait_reference);
282 visitor.visit_ty(typ);
283 walk_list!(visitor, visit_impl_item, impl_items);
285 ItemKind::Struct(ref struct_definition, ref generics) |
286 ItemKind::Union(ref struct_definition, ref generics) => {
287 visitor.visit_generics(generics);
288 visitor.visit_variant_data(struct_definition, item.ident,
289 generics, item.id, item.span);
291 ItemKind::Trait(_, ref generics, ref bounds, ref methods) => {
292 visitor.visit_generics(generics);
293 walk_list!(visitor, visit_ty_param_bound, bounds);
294 walk_list!(visitor, visit_trait_item, methods);
296 ItemKind::Mac(ref mac) => visitor.visit_mac(mac),
297 ItemKind::MacroDef(ref ts) => visitor.visit_mac_def(ts, item.id),
299 walk_list!(visitor, visit_attribute, &item.attrs);
302 pub fn walk_enum_def<'a, V: Visitor<'a>>(visitor: &mut V,
303 enum_definition: &'a EnumDef,
304 generics: &'a Generics,
306 walk_list!(visitor, visit_variant, &enum_definition.variants, generics, item_id);
309 pub fn walk_variant<'a, V>(visitor: &mut V,
310 variant: &'a Variant,
311 generics: &'a Generics,
313 where V: Visitor<'a>,
315 visitor.visit_ident(variant.span, variant.node.name);
316 visitor.visit_variant_data(&variant.node.data, variant.node.name,
317 generics, item_id, variant.span);
318 walk_list!(visitor, visit_expr, &variant.node.disr_expr);
319 walk_list!(visitor, visit_attribute, &variant.node.attrs);
322 pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) {
324 TyKind::Slice(ref ty) | TyKind::Paren(ref ty) => {
327 TyKind::Ptr(ref mutable_type) => {
328 visitor.visit_ty(&mutable_type.ty)
330 TyKind::Rptr(ref opt_lifetime, ref mutable_type) => {
331 walk_list!(visitor, visit_lifetime, opt_lifetime);
332 visitor.visit_ty(&mutable_type.ty)
335 TyKind::Tup(ref tuple_element_types) => {
336 walk_list!(visitor, visit_ty, tuple_element_types);
338 TyKind::BareFn(ref function_declaration) => {
339 walk_fn_decl(visitor, &function_declaration.decl);
340 walk_list!(visitor, visit_lifetime_def, &function_declaration.lifetimes);
342 TyKind::Path(ref maybe_qself, ref path) => {
343 if let Some(ref qself) = *maybe_qself {
344 visitor.visit_ty(&qself.ty);
346 visitor.visit_path(path, typ.id);
348 TyKind::Array(ref ty, ref expression) => {
349 visitor.visit_ty(ty);
350 visitor.visit_expr(expression)
352 TyKind::TraitObject(ref bounds) |
353 TyKind::ImplTrait(ref bounds) => {
354 walk_list!(visitor, visit_ty_param_bound, bounds);
356 TyKind::Typeof(ref expression) => {
357 visitor.visit_expr(expression)
359 TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => {}
360 TyKind::Mac(ref mac) => {
361 visitor.visit_mac(mac)
366 pub fn walk_path<'a, V: Visitor<'a>>(visitor: &mut V, path: &'a Path) {
367 for segment in &path.segments {
368 visitor.visit_path_segment(path.span, segment);
372 pub fn walk_path_list_item<'a, V: Visitor<'a>>(visitor: &mut V,
374 item: &'a PathListItem) {
375 visitor.visit_ident(item.span, item.node.name);
376 walk_opt_ident(visitor, item.span, item.node.rename);
379 pub fn walk_path_segment<'a, V: Visitor<'a>>(visitor: &mut V,
381 segment: &'a PathSegment) {
382 visitor.visit_ident(path_span, segment.identifier);
383 if let Some(ref parameters) = segment.parameters {
384 visitor.visit_path_parameters(path_span, parameters);
388 pub fn walk_path_parameters<'a, V>(visitor: &mut V,
390 path_parameters: &'a PathParameters)
391 where V: Visitor<'a>,
393 match *path_parameters {
394 PathParameters::AngleBracketed(ref data) => {
395 walk_list!(visitor, visit_ty, &data.types);
396 walk_list!(visitor, visit_lifetime, &data.lifetimes);
397 walk_list!(visitor, visit_assoc_type_binding, &data.bindings);
399 PathParameters::Parenthesized(ref data) => {
400 walk_list!(visitor, visit_ty, &data.inputs);
401 walk_list!(visitor, visit_ty, &data.output);
406 pub fn walk_assoc_type_binding<'a, V: Visitor<'a>>(visitor: &mut V,
407 type_binding: &'a TypeBinding) {
408 visitor.visit_ident(type_binding.span, type_binding.ident);
409 visitor.visit_ty(&type_binding.ty);
412 pub fn walk_pat<'a, V: Visitor<'a>>(visitor: &mut V, pattern: &'a Pat) {
414 PatKind::TupleStruct(ref path, ref children, _) => {
415 visitor.visit_path(path, pattern.id);
416 walk_list!(visitor, visit_pat, children);
418 PatKind::Path(ref opt_qself, ref path) => {
419 if let Some(ref qself) = *opt_qself {
420 visitor.visit_ty(&qself.ty);
422 visitor.visit_path(path, pattern.id)
424 PatKind::Struct(ref path, ref fields, _) => {
425 visitor.visit_path(path, pattern.id);
426 for field in fields {
427 walk_list!(visitor, visit_attribute, field.node.attrs.iter());
428 visitor.visit_ident(field.span, field.node.ident);
429 visitor.visit_pat(&field.node.pat)
432 PatKind::Tuple(ref tuple_elements, _) => {
433 walk_list!(visitor, visit_pat, tuple_elements);
435 PatKind::Box(ref subpattern) |
436 PatKind::Ref(ref subpattern, _) => {
437 visitor.visit_pat(subpattern)
439 PatKind::Ident(_, ref pth1, ref optional_subpattern) => {
440 visitor.visit_ident(pth1.span, pth1.node);
441 walk_list!(visitor, visit_pat, optional_subpattern);
443 PatKind::Lit(ref expression) => visitor.visit_expr(expression),
444 PatKind::Range(ref lower_bound, ref upper_bound, _) => {
445 visitor.visit_expr(lower_bound);
446 visitor.visit_expr(upper_bound);
449 PatKind::Slice(ref prepatterns, ref slice_pattern, ref postpatterns) => {
450 walk_list!(visitor, visit_pat, prepatterns);
451 walk_list!(visitor, visit_pat, slice_pattern);
452 walk_list!(visitor, visit_pat, postpatterns);
454 PatKind::Mac(ref mac) => visitor.visit_mac(mac),
458 pub fn walk_foreign_item<'a, V: Visitor<'a>>(visitor: &mut V, foreign_item: &'a ForeignItem) {
459 visitor.visit_vis(&foreign_item.vis);
460 visitor.visit_ident(foreign_item.span, foreign_item.ident);
462 match foreign_item.node {
463 ForeignItemKind::Fn(ref function_declaration, ref generics) => {
464 walk_fn_decl(visitor, function_declaration);
465 visitor.visit_generics(generics)
467 ForeignItemKind::Static(ref typ, _) => visitor.visit_ty(typ),
470 walk_list!(visitor, visit_attribute, &foreign_item.attrs);
473 pub fn walk_global_asm<'a, V: Visitor<'a>>(_: &mut V, _: &'a GlobalAsm) {
477 pub fn walk_ty_param_bound<'a, V: Visitor<'a>>(visitor: &mut V, bound: &'a TyParamBound) {
479 TraitTyParamBound(ref typ, ref modifier) => {
480 visitor.visit_poly_trait_ref(typ, modifier);
482 RegionTyParamBound(ref lifetime) => {
483 visitor.visit_lifetime(lifetime);
488 pub fn walk_generics<'a, V: Visitor<'a>>(visitor: &mut V, generics: &'a Generics) {
489 for param in &generics.ty_params {
490 visitor.visit_ident(param.span, param.ident);
491 walk_list!(visitor, visit_ty_param_bound, ¶m.bounds);
492 walk_list!(visitor, visit_ty, ¶m.default);
493 walk_list!(visitor, visit_attribute, &*param.attrs);
495 walk_list!(visitor, visit_lifetime_def, &generics.lifetimes);
496 walk_list!(visitor, visit_where_predicate, &generics.where_clause.predicates);
499 pub fn walk_where_predicate<'a, V: Visitor<'a>>(visitor: &mut V, predicate: &'a WherePredicate) {
501 WherePredicate::BoundPredicate(WhereBoundPredicate{ref bounded_ty,
505 visitor.visit_ty(bounded_ty);
506 walk_list!(visitor, visit_ty_param_bound, bounds);
507 walk_list!(visitor, visit_lifetime_def, bound_lifetimes);
509 WherePredicate::RegionPredicate(WhereRegionPredicate{ref lifetime,
512 visitor.visit_lifetime(lifetime);
513 walk_list!(visitor, visit_lifetime, bounds);
515 WherePredicate::EqPredicate(WhereEqPredicate{ref lhs_ty,
518 visitor.visit_ty(lhs_ty);
519 visitor.visit_ty(rhs_ty);
524 pub fn walk_fn_ret_ty<'a, V: Visitor<'a>>(visitor: &mut V, ret_ty: &'a FunctionRetTy) {
525 if let FunctionRetTy::Ty(ref output_ty) = *ret_ty {
526 visitor.visit_ty(output_ty)
530 pub fn walk_fn_decl<'a, V: Visitor<'a>>(visitor: &mut V, function_declaration: &'a FnDecl) {
531 for argument in &function_declaration.inputs {
532 visitor.visit_pat(&argument.pat);
533 visitor.visit_ty(&argument.ty)
535 visitor.visit_fn_ret_ty(&function_declaration.output)
538 pub fn walk_fn<'a, V>(visitor: &mut V, kind: FnKind<'a>, declaration: &'a FnDecl, _span: Span)
539 where V: Visitor<'a>,
542 FnKind::ItemFn(_, generics, _, _, _, _, body) => {
543 visitor.visit_generics(generics);
544 walk_fn_decl(visitor, declaration);
545 visitor.visit_block(body);
547 FnKind::Method(_, sig, _, body) => {
548 visitor.visit_generics(&sig.generics);
549 walk_fn_decl(visitor, declaration);
550 visitor.visit_block(body);
552 FnKind::Closure(body) => {
553 walk_fn_decl(visitor, declaration);
554 visitor.visit_expr(body);
559 pub fn walk_trait_item<'a, V: Visitor<'a>>(visitor: &mut V, trait_item: &'a TraitItem) {
560 visitor.visit_ident(trait_item.span, trait_item.ident);
561 walk_list!(visitor, visit_attribute, &trait_item.attrs);
562 match trait_item.node {
563 TraitItemKind::Const(ref ty, ref default) => {
564 visitor.visit_ty(ty);
565 walk_list!(visitor, visit_expr, default);
567 TraitItemKind::Method(ref sig, None) => {
568 visitor.visit_generics(&sig.generics);
569 walk_fn_decl(visitor, &sig.decl);
571 TraitItemKind::Method(ref sig, Some(ref body)) => {
572 visitor.visit_fn(FnKind::Method(trait_item.ident, sig, None, body),
573 &sig.decl, trait_item.span, trait_item.id);
575 TraitItemKind::Type(ref bounds, ref default) => {
576 walk_list!(visitor, visit_ty_param_bound, bounds);
577 walk_list!(visitor, visit_ty, default);
579 TraitItemKind::Macro(ref mac) => {
580 visitor.visit_mac(mac);
585 pub fn walk_impl_item<'a, V: Visitor<'a>>(visitor: &mut V, impl_item: &'a ImplItem) {
586 visitor.visit_vis(&impl_item.vis);
587 visitor.visit_ident(impl_item.span, impl_item.ident);
588 walk_list!(visitor, visit_attribute, &impl_item.attrs);
589 match impl_item.node {
590 ImplItemKind::Const(ref ty, ref expr) => {
591 visitor.visit_ty(ty);
592 visitor.visit_expr(expr);
594 ImplItemKind::Method(ref sig, ref body) => {
595 visitor.visit_fn(FnKind::Method(impl_item.ident, sig, Some(&impl_item.vis), body),
596 &sig.decl, impl_item.span, impl_item.id);
598 ImplItemKind::Type(ref ty) => {
599 visitor.visit_ty(ty);
601 ImplItemKind::Macro(ref mac) => {
602 visitor.visit_mac(mac);
607 pub fn walk_struct_def<'a, V: Visitor<'a>>(visitor: &mut V, struct_definition: &'a VariantData) {
608 walk_list!(visitor, visit_struct_field, struct_definition.fields());
611 pub fn walk_struct_field<'a, V: Visitor<'a>>(visitor: &mut V, struct_field: &'a StructField) {
612 visitor.visit_vis(&struct_field.vis);
613 walk_opt_ident(visitor, struct_field.span, struct_field.ident);
614 visitor.visit_ty(&struct_field.ty);
615 walk_list!(visitor, visit_attribute, &struct_field.attrs);
618 pub fn walk_block<'a, V: Visitor<'a>>(visitor: &mut V, block: &'a Block) {
619 walk_list!(visitor, visit_stmt, &block.stmts);
622 pub fn walk_stmt<'a, V: Visitor<'a>>(visitor: &mut V, statement: &'a Stmt) {
623 match statement.node {
624 StmtKind::Local(ref local) => visitor.visit_local(local),
625 StmtKind::Item(ref item) => visitor.visit_item(item),
626 StmtKind::Expr(ref expression) | StmtKind::Semi(ref expression) => {
627 visitor.visit_expr(expression)
629 StmtKind::Mac(ref mac) => {
630 let (ref mac, _, ref attrs) = **mac;
631 visitor.visit_mac(mac);
632 for attr in attrs.iter() {
633 visitor.visit_attribute(attr);
639 pub fn walk_mac<'a, V: Visitor<'a>>(_: &mut V, _: &Mac) {
643 pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
644 for attr in expression.attrs.iter() {
645 visitor.visit_attribute(attr);
647 match expression.node {
648 ExprKind::Box(ref subexpression) => {
649 visitor.visit_expr(subexpression)
651 ExprKind::InPlace(ref place, ref subexpression) => {
652 visitor.visit_expr(place);
653 visitor.visit_expr(subexpression)
655 ExprKind::Array(ref subexpressions) => {
656 walk_list!(visitor, visit_expr, subexpressions);
658 ExprKind::Repeat(ref element, ref count) => {
659 visitor.visit_expr(element);
660 visitor.visit_expr(count)
662 ExprKind::Struct(ref path, ref fields, ref optional_base) => {
663 visitor.visit_path(path, expression.id);
664 for field in fields {
665 walk_list!(visitor, visit_attribute, field.attrs.iter());
666 visitor.visit_ident(field.ident.span, field.ident.node);
667 visitor.visit_expr(&field.expr)
669 walk_list!(visitor, visit_expr, optional_base);
671 ExprKind::Tup(ref subexpressions) => {
672 walk_list!(visitor, visit_expr, subexpressions);
674 ExprKind::Call(ref callee_expression, ref arguments) => {
675 visitor.visit_expr(callee_expression);
676 walk_list!(visitor, visit_expr, arguments);
678 ExprKind::MethodCall(ref ident, ref types, ref arguments) => {
679 visitor.visit_ident(ident.span, ident.node);
680 walk_list!(visitor, visit_ty, types);
681 walk_list!(visitor, visit_expr, arguments);
683 ExprKind::Binary(_, ref left_expression, ref right_expression) => {
684 visitor.visit_expr(left_expression);
685 visitor.visit_expr(right_expression)
687 ExprKind::AddrOf(_, ref subexpression) | ExprKind::Unary(_, ref subexpression) => {
688 visitor.visit_expr(subexpression)
690 ExprKind::Lit(_) => {}
691 ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => {
692 visitor.visit_expr(subexpression);
693 visitor.visit_ty(typ)
695 ExprKind::If(ref head_expression, ref if_block, ref optional_else) => {
696 visitor.visit_expr(head_expression);
697 visitor.visit_block(if_block);
698 walk_list!(visitor, visit_expr, optional_else);
700 ExprKind::While(ref subexpression, ref block, ref opt_sp_ident) => {
701 visitor.visit_expr(subexpression);
702 visitor.visit_block(block);
703 walk_opt_sp_ident(visitor, opt_sp_ident);
705 ExprKind::IfLet(ref pattern, ref subexpression, ref if_block, ref optional_else) => {
706 visitor.visit_pat(pattern);
707 visitor.visit_expr(subexpression);
708 visitor.visit_block(if_block);
709 walk_list!(visitor, visit_expr, optional_else);
711 ExprKind::WhileLet(ref pattern, ref subexpression, ref block, ref opt_sp_ident) => {
712 visitor.visit_pat(pattern);
713 visitor.visit_expr(subexpression);
714 visitor.visit_block(block);
715 walk_opt_sp_ident(visitor, opt_sp_ident);
717 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, ref opt_sp_ident) => {
718 visitor.visit_pat(pattern);
719 visitor.visit_expr(subexpression);
720 visitor.visit_block(block);
721 walk_opt_sp_ident(visitor, opt_sp_ident);
723 ExprKind::Loop(ref block, ref opt_sp_ident) => {
724 visitor.visit_block(block);
725 walk_opt_sp_ident(visitor, opt_sp_ident);
727 ExprKind::Match(ref subexpression, ref arms) => {
728 visitor.visit_expr(subexpression);
729 walk_list!(visitor, visit_arm, arms);
731 ExprKind::Closure(_, ref function_declaration, ref body, _decl_span) => {
732 visitor.visit_fn(FnKind::Closure(body),
733 function_declaration,
737 ExprKind::Block(ref block) => visitor.visit_block(block),
738 ExprKind::Assign(ref left_hand_expression, ref right_hand_expression) => {
739 visitor.visit_expr(left_hand_expression);
740 visitor.visit_expr(right_hand_expression);
742 ExprKind::AssignOp(_, ref left_expression, ref right_expression) => {
743 visitor.visit_expr(left_expression);
744 visitor.visit_expr(right_expression);
746 ExprKind::Field(ref subexpression, ref ident) => {
747 visitor.visit_expr(subexpression);
748 visitor.visit_ident(ident.span, ident.node);
750 ExprKind::TupField(ref subexpression, _) => {
751 visitor.visit_expr(subexpression);
753 ExprKind::Index(ref main_expression, ref index_expression) => {
754 visitor.visit_expr(main_expression);
755 visitor.visit_expr(index_expression)
757 ExprKind::Range(ref start, ref end, _) => {
758 walk_list!(visitor, visit_expr, start);
759 walk_list!(visitor, visit_expr, end);
761 ExprKind::Path(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 ExprKind::Break(ref opt_sp_ident, ref opt_expr) => {
768 walk_opt_sp_ident(visitor, opt_sp_ident);
769 walk_list!(visitor, visit_expr, opt_expr);
771 ExprKind::Continue(ref opt_sp_ident) => {
772 walk_opt_sp_ident(visitor, opt_sp_ident);
774 ExprKind::Ret(ref optional_expression) => {
775 walk_list!(visitor, visit_expr, optional_expression);
777 ExprKind::Mac(ref mac) => visitor.visit_mac(mac),
778 ExprKind::Paren(ref subexpression) => {
779 visitor.visit_expr(subexpression)
781 ExprKind::InlineAsm(ref ia) => {
782 for &(_, ref input) in &ia.inputs {
783 visitor.visit_expr(input)
785 for output in &ia.outputs {
786 visitor.visit_expr(&output.expr)
789 ExprKind::Try(ref subexpression) => {
790 visitor.visit_expr(subexpression)
792 ExprKind::Catch(ref body) => {
793 visitor.visit_block(body)
797 visitor.visit_expr_post(expression)
800 pub fn walk_arm<'a, V: Visitor<'a>>(visitor: &mut V, arm: &'a Arm) {
801 walk_list!(visitor, visit_pat, &arm.pats);
802 walk_list!(visitor, visit_expr, &arm.guard);
803 visitor.visit_expr(&arm.body);
804 walk_list!(visitor, visit_attribute, &arm.attrs);
807 pub fn walk_vis<'a, V: Visitor<'a>>(visitor: &mut V, vis: &'a Visibility) {
808 if let Visibility::Restricted { ref path, id } = *vis {
809 visitor.visit_path(path, id);