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 parse::token::Token;
31 use tokenstream::{TokenTree, TokenStream};
33 #[derive(Copy, Clone, PartialEq, Eq)]
35 /// fn foo() or extern "Abi" fn foo()
36 ItemFn(Ident, Unsafety, Spanned<Constness>, Abi, &'a Visibility, &'a Block),
39 Method(Ident, &'a MethodSig, Option<&'a Visibility>, &'a Block),
45 /// Each method of the Visitor trait is a hook to be potentially
46 /// overridden. Each method's default implementation recursively visits
47 /// the substructure of the input via the corresponding `walk` method;
48 /// e.g. the `visit_mod` method by default calls `visit::walk_mod`.
50 /// If you want to ensure that your code handles every variant
51 /// explicitly, you need to override each method. (And you also need
52 /// to monitor future changes to `Visitor` in case a new method with a
53 /// new default implementation gets introduced.)
54 pub trait Visitor<'ast>: Sized {
55 fn visit_name(&mut self, _span: Span, _name: Name) {
58 fn visit_ident(&mut self, span: Span, ident: Ident) {
59 walk_ident(self, span, ident);
61 fn visit_mod(&mut self, m: &'ast Mod, _s: Span, _attrs: &[Attribute], _n: NodeId) {
64 fn visit_foreign_item(&mut self, i: &'ast ForeignItem) { walk_foreign_item(self, i) }
65 fn visit_global_asm(&mut self, ga: &'ast GlobalAsm) { walk_global_asm(self, ga) }
66 fn visit_item(&mut self, i: &'ast Item) { walk_item(self, i) }
67 fn visit_local(&mut self, l: &'ast Local) { walk_local(self, l) }
68 fn visit_block(&mut self, b: &'ast Block) { walk_block(self, b) }
69 fn visit_stmt(&mut self, s: &'ast Stmt) { walk_stmt(self, s) }
70 fn visit_arm(&mut self, a: &'ast Arm) { walk_arm(self, a) }
71 fn visit_pat(&mut self, p: &'ast Pat) { walk_pat(self, p) }
72 fn visit_expr(&mut self, ex: &'ast Expr) { walk_expr(self, ex) }
73 fn visit_expr_post(&mut self, _ex: &'ast Expr) { }
74 fn visit_ty(&mut self, t: &'ast Ty) { walk_ty(self, t) }
75 fn visit_generic_param(&mut self, param: &'ast GenericParam) { walk_generic_param(self, param) }
76 fn visit_generics(&mut self, g: &'ast Generics) { walk_generics(self, g) }
77 fn visit_where_predicate(&mut self, p: &'ast WherePredicate) {
78 walk_where_predicate(self, p)
80 fn visit_fn(&mut self, fk: FnKind<'ast>, fd: &'ast FnDecl, s: Span, _: NodeId) {
81 walk_fn(self, fk, fd, s)
83 fn visit_trait_item(&mut self, ti: &'ast TraitItem) { walk_trait_item(self, ti) }
84 fn visit_impl_item(&mut self, ii: &'ast ImplItem) { walk_impl_item(self, ii) }
85 fn visit_trait_ref(&mut self, t: &'ast TraitRef) { walk_trait_ref(self, t) }
86 fn visit_ty_param_bound(&mut self, bounds: &'ast TyParamBound) {
87 walk_ty_param_bound(self, bounds)
89 fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef, m: &'ast TraitBoundModifier) {
90 walk_poly_trait_ref(self, t, m)
92 fn visit_variant_data(&mut self, s: &'ast VariantData, _: Ident,
93 _: &'ast Generics, _: NodeId, _: Span) {
94 walk_struct_def(self, s)
96 fn visit_struct_field(&mut self, s: &'ast StructField) { walk_struct_field(self, s) }
97 fn visit_enum_def(&mut self, enum_definition: &'ast EnumDef,
98 generics: &'ast Generics, item_id: NodeId, _: Span) {
99 walk_enum_def(self, enum_definition, generics, item_id)
101 fn visit_variant(&mut self, v: &'ast Variant, g: &'ast Generics, item_id: NodeId) {
102 walk_variant(self, v, g, item_id)
104 fn visit_label(&mut self, label: &'ast Label) {
105 walk_label(self, label)
107 fn visit_lifetime(&mut self, lifetime: &'ast Lifetime) {
108 walk_lifetime(self, lifetime)
110 fn visit_mac(&mut self, _mac: &'ast Mac) {
111 panic!("visit_mac disabled by default");
112 // NB: see note about macros above.
113 // if you really want a visitor that
114 // works on macros, use this
115 // definition in your trait impl:
116 // visit::walk_mac(self, _mac)
118 fn visit_mac_def(&mut self, _mac: &'ast MacroDef, _id: NodeId) {
121 fn visit_path(&mut self, path: &'ast Path, _id: NodeId) {
122 walk_path(self, path)
124 fn visit_use_tree(&mut self, use_tree: &'ast UseTree, id: NodeId, _nested: bool) {
125 walk_use_tree(self, use_tree, id)
127 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'ast PathSegment) {
128 walk_path_segment(self, path_span, path_segment)
130 fn visit_path_parameters(&mut self, path_span: Span, path_parameters: &'ast PathParameters) {
131 walk_path_parameters(self, path_span, path_parameters)
133 fn visit_assoc_type_binding(&mut self, type_binding: &'ast TypeBinding) {
134 walk_assoc_type_binding(self, type_binding)
136 fn visit_attribute(&mut self, attr: &'ast Attribute) {
137 walk_attribute(self, attr)
139 fn visit_tt(&mut self, tt: TokenTree) {
142 fn visit_tts(&mut self, tts: TokenStream) {
145 fn visit_token(&mut self, _t: Token) {}
146 // FIXME: add `visit_interpolated` and `walk_interpolated`
147 fn visit_vis(&mut self, vis: &'ast Visibility) {
150 fn visit_fn_ret_ty(&mut self, ret_ty: &'ast FunctionRetTy) {
151 walk_fn_ret_ty(self, ret_ty)
156 macro_rules! walk_list {
157 ($visitor: expr, $method: ident, $list: expr) => {
159 $visitor.$method(elem)
162 ($visitor: expr, $method: ident, $list: expr, $($extra_args: expr),*) => {
164 $visitor.$method(elem, $($extra_args,)*)
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, &krate.attrs, 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_label<'a, V: Visitor<'a>>(visitor: &mut V, label: &'a Label) {
192 visitor.visit_ident(label.span, label.ident);
195 pub fn walk_lifetime<'a, V: Visitor<'a>>(visitor: &mut V, lifetime: &'a Lifetime) {
196 visitor.visit_ident(lifetime.span, lifetime.ident);
199 pub fn walk_poly_trait_ref<'a, V>(visitor: &mut V,
200 trait_ref: &'a PolyTraitRef,
201 _: &TraitBoundModifier)
202 where V: Visitor<'a>,
204 walk_list!(visitor, visit_generic_param, &trait_ref.bound_generic_params);
205 visitor.visit_trait_ref(&trait_ref.trait_ref);
208 pub fn walk_trait_ref<'a, V: Visitor<'a>>(visitor: &mut V, trait_ref: &'a TraitRef) {
209 visitor.visit_path(&trait_ref.path, trait_ref.ref_id)
212 pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
213 visitor.visit_vis(&item.vis);
214 visitor.visit_ident(item.span, item.ident);
216 ItemKind::ExternCrate(orig_name) => {
217 if let Some(orig_name) = orig_name {
218 visitor.visit_name(item.span, orig_name);
221 ItemKind::Use(ref use_tree) => {
222 visitor.visit_use_tree(use_tree, item.id, false)
224 ItemKind::Static(ref typ, _, ref expr) |
225 ItemKind::Const(ref typ, ref expr) => {
226 visitor.visit_ty(typ);
227 visitor.visit_expr(expr);
229 ItemKind::Fn(ref declaration, unsafety, constness, abi, ref generics, ref body) => {
230 visitor.visit_generics(generics);
231 visitor.visit_fn(FnKind::ItemFn(item.ident, unsafety,
232 constness, abi, &item.vis, body),
237 ItemKind::Mod(ref module) => {
238 visitor.visit_mod(module, item.span, &item.attrs, item.id)
240 ItemKind::ForeignMod(ref foreign_module) => {
241 walk_list!(visitor, visit_foreign_item, &foreign_module.items);
243 ItemKind::GlobalAsm(ref ga) => visitor.visit_global_asm(ga),
244 ItemKind::Ty(ref typ, ref type_parameters) => {
245 visitor.visit_ty(typ);
246 visitor.visit_generics(type_parameters)
248 ItemKind::Enum(ref enum_definition, ref type_parameters) => {
249 visitor.visit_generics(type_parameters);
250 visitor.visit_enum_def(enum_definition, type_parameters, item.id, item.span)
252 ItemKind::Impl(_, _, _,
254 ref opt_trait_reference,
257 visitor.visit_generics(type_parameters);
258 walk_list!(visitor, visit_trait_ref, opt_trait_reference);
259 visitor.visit_ty(typ);
260 walk_list!(visitor, visit_impl_item, impl_items);
262 ItemKind::Struct(ref struct_definition, ref generics) |
263 ItemKind::Union(ref struct_definition, ref generics) => {
264 visitor.visit_generics(generics);
265 visitor.visit_variant_data(struct_definition, item.ident,
266 generics, item.id, item.span);
268 ItemKind::Trait(.., ref generics, ref bounds, ref methods) => {
269 visitor.visit_generics(generics);
270 walk_list!(visitor, visit_ty_param_bound, bounds);
271 walk_list!(visitor, visit_trait_item, methods);
273 ItemKind::TraitAlias(ref generics, ref bounds) => {
274 visitor.visit_generics(generics);
275 walk_list!(visitor, visit_ty_param_bound, bounds);
277 ItemKind::Mac(ref mac) => visitor.visit_mac(mac),
278 ItemKind::MacroDef(ref ts) => visitor.visit_mac_def(ts, item.id),
280 walk_list!(visitor, visit_attribute, &item.attrs);
283 pub fn walk_enum_def<'a, V: Visitor<'a>>(visitor: &mut V,
284 enum_definition: &'a EnumDef,
285 generics: &'a Generics,
287 walk_list!(visitor, visit_variant, &enum_definition.variants, generics, item_id);
290 pub fn walk_variant<'a, V>(visitor: &mut V,
291 variant: &'a Variant,
292 generics: &'a Generics,
294 where V: Visitor<'a>,
296 visitor.visit_ident(variant.span, variant.node.name);
297 visitor.visit_variant_data(&variant.node.data, variant.node.name,
298 generics, item_id, variant.span);
299 walk_list!(visitor, visit_expr, &variant.node.disr_expr);
300 walk_list!(visitor, visit_attribute, &variant.node.attrs);
303 pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) {
305 TyKind::Slice(ref ty) | TyKind::Paren(ref ty) => {
308 TyKind::Ptr(ref mutable_type) => {
309 visitor.visit_ty(&mutable_type.ty)
311 TyKind::Rptr(ref opt_lifetime, ref mutable_type) => {
312 walk_list!(visitor, visit_lifetime, opt_lifetime);
313 visitor.visit_ty(&mutable_type.ty)
316 TyKind::Tup(ref tuple_element_types) => {
317 walk_list!(visitor, visit_ty, tuple_element_types);
319 TyKind::BareFn(ref function_declaration) => {
320 walk_fn_decl(visitor, &function_declaration.decl);
321 walk_list!(visitor, visit_generic_param, &function_declaration.generic_params);
323 TyKind::Path(ref maybe_qself, ref path) => {
324 if let Some(ref qself) = *maybe_qself {
325 visitor.visit_ty(&qself.ty);
327 visitor.visit_path(path, typ.id);
329 TyKind::Array(ref ty, ref expression) => {
330 visitor.visit_ty(ty);
331 visitor.visit_expr(expression)
333 TyKind::TraitObject(ref bounds, ..) |
334 TyKind::ImplTrait(ref bounds) => {
335 walk_list!(visitor, visit_ty_param_bound, bounds);
337 TyKind::Typeof(ref expression) => {
338 visitor.visit_expr(expression)
340 TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => {}
341 TyKind::Mac(ref mac) => {
342 visitor.visit_mac(mac)
347 pub fn walk_path<'a, V: Visitor<'a>>(visitor: &mut V, path: &'a Path) {
348 for segment in &path.segments {
349 visitor.visit_path_segment(path.span, segment);
353 pub fn walk_use_tree<'a, V: Visitor<'a>>(
354 visitor: &mut V, use_tree: &'a UseTree, id: NodeId,
356 visitor.visit_path(&use_tree.prefix, id);
357 match use_tree.kind {
358 UseTreeKind::Simple(rename) => {
359 if let Some(rename) = rename {
360 visitor.visit_ident(use_tree.span, rename);
363 UseTreeKind::Glob => {},
364 UseTreeKind::Nested(ref use_trees) => {
365 for &(ref nested_tree, nested_id) in use_trees {
366 visitor.visit_use_tree(nested_tree, nested_id, true);
372 pub fn walk_path_segment<'a, V: Visitor<'a>>(visitor: &mut V,
374 segment: &'a PathSegment) {
375 visitor.visit_ident(path_span, segment.identifier);
376 if let Some(ref parameters) = segment.parameters {
377 visitor.visit_path_parameters(path_span, parameters);
381 pub fn walk_path_parameters<'a, V>(visitor: &mut V,
383 path_parameters: &'a PathParameters)
384 where V: Visitor<'a>,
386 match *path_parameters {
387 PathParameters::AngleBracketed(ref data) => {
388 walk_list!(visitor, visit_ty, &data.types);
389 walk_list!(visitor, visit_lifetime, &data.lifetimes);
390 walk_list!(visitor, visit_assoc_type_binding, &data.bindings);
392 PathParameters::Parenthesized(ref data) => {
393 walk_list!(visitor, visit_ty, &data.inputs);
394 walk_list!(visitor, visit_ty, &data.output);
399 pub fn walk_assoc_type_binding<'a, V: Visitor<'a>>(visitor: &mut V,
400 type_binding: &'a TypeBinding) {
401 visitor.visit_ident(type_binding.span, type_binding.ident);
402 visitor.visit_ty(&type_binding.ty);
405 pub fn walk_pat<'a, V: Visitor<'a>>(visitor: &mut V, pattern: &'a Pat) {
407 PatKind::TupleStruct(ref path, ref children, _) => {
408 visitor.visit_path(path, pattern.id);
409 walk_list!(visitor, visit_pat, children);
411 PatKind::Path(ref opt_qself, ref path) => {
412 if let Some(ref qself) = *opt_qself {
413 visitor.visit_ty(&qself.ty);
415 visitor.visit_path(path, pattern.id)
417 PatKind::Struct(ref path, ref fields, _) => {
418 visitor.visit_path(path, pattern.id);
419 for field in fields {
420 walk_list!(visitor, visit_attribute, field.node.attrs.iter());
421 visitor.visit_ident(field.span, field.node.ident);
422 visitor.visit_pat(&field.node.pat)
425 PatKind::Tuple(ref tuple_elements, _) => {
426 walk_list!(visitor, visit_pat, tuple_elements);
428 PatKind::Box(ref subpattern) |
429 PatKind::Ref(ref subpattern, _) |
430 PatKind::Paren(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),
462 ForeignItemKind::Ty => (),
463 ForeignItemKind::Macro(ref mac) => visitor.visit_mac(mac),
466 walk_list!(visitor, visit_attribute, &foreign_item.attrs);
469 pub fn walk_global_asm<'a, V: Visitor<'a>>(_: &mut V, _: &'a GlobalAsm) {
473 pub fn walk_ty_param_bound<'a, V: Visitor<'a>>(visitor: &mut V, bound: &'a TyParamBound) {
475 TraitTyParamBound(ref typ, ref modifier) => {
476 visitor.visit_poly_trait_ref(typ, modifier);
478 RegionTyParamBound(ref lifetime) => {
479 visitor.visit_lifetime(lifetime);
484 pub fn walk_generic_param<'a, V: Visitor<'a>>(visitor: &mut V, param: &'a GenericParam) {
486 GenericParam::Lifetime(ref l) => {
487 visitor.visit_lifetime(&l.lifetime);
488 walk_list!(visitor, visit_lifetime, &l.bounds);
489 walk_list!(visitor, visit_attribute, &*l.attrs);
491 GenericParam::Type(ref t) => {
492 visitor.visit_ident(t.span, t.ident);
493 walk_list!(visitor, visit_ty_param_bound, &t.bounds);
494 walk_list!(visitor, visit_ty, &t.default);
495 walk_list!(visitor, visit_attribute, &*t.attrs);
500 pub fn walk_generics<'a, V: Visitor<'a>>(visitor: &mut V, generics: &'a Generics) {
501 walk_list!(visitor, visit_generic_param, &generics.params);
502 walk_list!(visitor, visit_where_predicate, &generics.where_clause.predicates);
505 pub fn walk_where_predicate<'a, V: Visitor<'a>>(visitor: &mut V, predicate: &'a WherePredicate) {
507 WherePredicate::BoundPredicate(WhereBoundPredicate{ref bounded_ty,
509 ref bound_generic_params,
511 visitor.visit_ty(bounded_ty);
512 walk_list!(visitor, visit_ty_param_bound, bounds);
513 walk_list!(visitor, visit_generic_param, bound_generic_params);
515 WherePredicate::RegionPredicate(WhereRegionPredicate{ref lifetime,
518 visitor.visit_lifetime(lifetime);
519 walk_list!(visitor, visit_lifetime, bounds);
521 WherePredicate::EqPredicate(WhereEqPredicate{ref lhs_ty,
524 visitor.visit_ty(lhs_ty);
525 visitor.visit_ty(rhs_ty);
530 pub fn walk_fn_ret_ty<'a, V: Visitor<'a>>(visitor: &mut V, ret_ty: &'a FunctionRetTy) {
531 if let FunctionRetTy::Ty(ref output_ty) = *ret_ty {
532 visitor.visit_ty(output_ty)
536 pub fn walk_fn_decl<'a, V: Visitor<'a>>(visitor: &mut V, function_declaration: &'a FnDecl) {
537 for argument in &function_declaration.inputs {
538 visitor.visit_pat(&argument.pat);
539 visitor.visit_ty(&argument.ty)
541 visitor.visit_fn_ret_ty(&function_declaration.output)
544 pub fn walk_fn<'a, V>(visitor: &mut V, kind: FnKind<'a>, declaration: &'a FnDecl, _span: Span)
545 where V: Visitor<'a>,
548 FnKind::ItemFn(_, _, _, _, _, body) => {
549 walk_fn_decl(visitor, declaration);
550 visitor.visit_block(body);
552 FnKind::Method(_, _, _, body) => {
553 walk_fn_decl(visitor, declaration);
554 visitor.visit_block(body);
556 FnKind::Closure(body) => {
557 walk_fn_decl(visitor, declaration);
558 visitor.visit_expr(body);
563 pub fn walk_trait_item<'a, V: Visitor<'a>>(visitor: &mut V, trait_item: &'a TraitItem) {
564 visitor.visit_ident(trait_item.span, trait_item.ident);
565 walk_list!(visitor, visit_attribute, &trait_item.attrs);
566 visitor.visit_generics(&trait_item.generics);
567 match trait_item.node {
568 TraitItemKind::Const(ref ty, ref default) => {
569 visitor.visit_ty(ty);
570 walk_list!(visitor, visit_expr, default);
572 TraitItemKind::Method(ref sig, None) => {
573 walk_fn_decl(visitor, &sig.decl);
575 TraitItemKind::Method(ref sig, Some(ref body)) => {
576 visitor.visit_fn(FnKind::Method(trait_item.ident, sig, None, body),
577 &sig.decl, trait_item.span, trait_item.id);
579 TraitItemKind::Type(ref bounds, ref default) => {
580 walk_list!(visitor, visit_ty_param_bound, bounds);
581 walk_list!(visitor, visit_ty, default);
583 TraitItemKind::Macro(ref mac) => {
584 visitor.visit_mac(mac);
589 pub fn walk_impl_item<'a, V: Visitor<'a>>(visitor: &mut V, impl_item: &'a ImplItem) {
590 visitor.visit_vis(&impl_item.vis);
591 visitor.visit_ident(impl_item.span, impl_item.ident);
592 walk_list!(visitor, visit_attribute, &impl_item.attrs);
593 visitor.visit_generics(&impl_item.generics);
594 match impl_item.node {
595 ImplItemKind::Const(ref ty, ref expr) => {
596 visitor.visit_ty(ty);
597 visitor.visit_expr(expr);
599 ImplItemKind::Method(ref sig, ref body) => {
600 visitor.visit_fn(FnKind::Method(impl_item.ident, sig, Some(&impl_item.vis), body),
601 &sig.decl, impl_item.span, impl_item.id);
603 ImplItemKind::Type(ref ty) => {
604 visitor.visit_ty(ty);
606 ImplItemKind::Macro(ref mac) => {
607 visitor.visit_mac(mac);
612 pub fn walk_struct_def<'a, V: Visitor<'a>>(visitor: &mut V, struct_definition: &'a VariantData) {
613 walk_list!(visitor, visit_struct_field, struct_definition.fields());
616 pub fn walk_struct_field<'a, V: Visitor<'a>>(visitor: &mut V, struct_field: &'a StructField) {
617 visitor.visit_vis(&struct_field.vis);
618 if let Some(ident) = struct_field.ident {
619 visitor.visit_ident(struct_field.span, ident);
621 visitor.visit_ty(&struct_field.ty);
622 walk_list!(visitor, visit_attribute, &struct_field.attrs);
625 pub fn walk_block<'a, V: Visitor<'a>>(visitor: &mut V, block: &'a Block) {
626 walk_list!(visitor, visit_stmt, &block.stmts);
629 pub fn walk_stmt<'a, V: Visitor<'a>>(visitor: &mut V, statement: &'a Stmt) {
630 match statement.node {
631 StmtKind::Local(ref local) => visitor.visit_local(local),
632 StmtKind::Item(ref item) => visitor.visit_item(item),
633 StmtKind::Expr(ref expression) | StmtKind::Semi(ref expression) => {
634 visitor.visit_expr(expression)
636 StmtKind::Mac(ref mac) => {
637 let (ref mac, _, ref attrs) = **mac;
638 visitor.visit_mac(mac);
639 for attr in attrs.iter() {
640 visitor.visit_attribute(attr);
646 pub fn walk_mac<'a, V: Visitor<'a>>(_: &mut V, _: &Mac) {
650 pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
651 for attr in expression.attrs.iter() {
652 visitor.visit_attribute(attr);
654 match expression.node {
655 ExprKind::Box(ref subexpression) => {
656 visitor.visit_expr(subexpression)
658 ExprKind::Array(ref subexpressions) => {
659 walk_list!(visitor, visit_expr, subexpressions);
661 ExprKind::Repeat(ref element, ref count) => {
662 visitor.visit_expr(element);
663 visitor.visit_expr(count)
665 ExprKind::Struct(ref path, ref fields, ref optional_base) => {
666 visitor.visit_path(path, expression.id);
667 for field in fields {
668 walk_list!(visitor, visit_attribute, field.attrs.iter());
669 visitor.visit_ident(field.ident.span, field.ident.node);
670 visitor.visit_expr(&field.expr)
672 walk_list!(visitor, visit_expr, optional_base);
674 ExprKind::Tup(ref subexpressions) => {
675 walk_list!(visitor, visit_expr, subexpressions);
677 ExprKind::Call(ref callee_expression, ref arguments) => {
678 visitor.visit_expr(callee_expression);
679 walk_list!(visitor, visit_expr, arguments);
681 ExprKind::MethodCall(ref segment, ref arguments) => {
682 visitor.visit_path_segment(expression.span, segment);
683 walk_list!(visitor, visit_expr, arguments);
685 ExprKind::Binary(_, ref left_expression, ref right_expression) => {
686 visitor.visit_expr(left_expression);
687 visitor.visit_expr(right_expression)
689 ExprKind::AddrOf(_, ref subexpression) | ExprKind::Unary(_, ref subexpression) => {
690 visitor.visit_expr(subexpression)
692 ExprKind::Lit(_) => {}
693 ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => {
694 visitor.visit_expr(subexpression);
695 visitor.visit_ty(typ)
697 ExprKind::If(ref head_expression, ref if_block, ref optional_else) => {
698 visitor.visit_expr(head_expression);
699 visitor.visit_block(if_block);
700 walk_list!(visitor, visit_expr, optional_else);
702 ExprKind::While(ref subexpression, ref block, ref opt_label) => {
703 walk_list!(visitor, visit_label, opt_label);
704 visitor.visit_expr(subexpression);
705 visitor.visit_block(block);
707 ExprKind::IfLet(ref pats, ref subexpression, ref if_block, ref optional_else) => {
708 walk_list!(visitor, visit_pat, pats);
709 visitor.visit_expr(subexpression);
710 visitor.visit_block(if_block);
711 walk_list!(visitor, visit_expr, optional_else);
713 ExprKind::WhileLet(ref pats, ref subexpression, ref block, ref opt_label) => {
714 walk_list!(visitor, visit_label, opt_label);
715 walk_list!(visitor, visit_pat, pats);
716 visitor.visit_expr(subexpression);
717 visitor.visit_block(block);
719 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, ref opt_label) => {
720 walk_list!(visitor, visit_label, opt_label);
721 visitor.visit_pat(pattern);
722 visitor.visit_expr(subexpression);
723 visitor.visit_block(block);
725 ExprKind::Loop(ref block, ref opt_label) => {
726 walk_list!(visitor, visit_label, opt_label);
727 visitor.visit_block(block);
729 ExprKind::Match(ref subexpression, ref arms) => {
730 visitor.visit_expr(subexpression);
731 walk_list!(visitor, visit_arm, arms);
733 ExprKind::Closure(_, _, ref function_declaration, ref body, _decl_span) => {
734 visitor.visit_fn(FnKind::Closure(body),
735 function_declaration,
739 ExprKind::Block(ref block) => visitor.visit_block(block),
740 ExprKind::Assign(ref left_hand_expression, ref right_hand_expression) => {
741 visitor.visit_expr(left_hand_expression);
742 visitor.visit_expr(right_hand_expression);
744 ExprKind::AssignOp(_, ref left_expression, ref right_expression) => {
745 visitor.visit_expr(left_expression);
746 visitor.visit_expr(right_expression);
748 ExprKind::Field(ref subexpression, ref ident) => {
749 visitor.visit_expr(subexpression);
750 visitor.visit_ident(ident.span, ident.node);
752 ExprKind::TupField(ref subexpression, _) => {
753 visitor.visit_expr(subexpression);
755 ExprKind::Index(ref main_expression, ref index_expression) => {
756 visitor.visit_expr(main_expression);
757 visitor.visit_expr(index_expression)
759 ExprKind::Range(ref start, ref end, _) => {
760 walk_list!(visitor, visit_expr, start);
761 walk_list!(visitor, visit_expr, end);
763 ExprKind::Path(ref maybe_qself, ref path) => {
764 if let Some(ref qself) = *maybe_qself {
765 visitor.visit_ty(&qself.ty);
767 visitor.visit_path(path, expression.id)
769 ExprKind::Break(ref opt_label, ref opt_expr) => {
770 walk_list!(visitor, visit_label, opt_label);
771 walk_list!(visitor, visit_expr, opt_expr);
773 ExprKind::Continue(ref opt_label) => {
774 walk_list!(visitor, visit_label, opt_label);
776 ExprKind::Ret(ref optional_expression) => {
777 walk_list!(visitor, visit_expr, optional_expression);
779 ExprKind::Mac(ref mac) => visitor.visit_mac(mac),
780 ExprKind::Paren(ref subexpression) => {
781 visitor.visit_expr(subexpression)
783 ExprKind::InlineAsm(ref ia) => {
784 for &(_, ref input) in &ia.inputs {
785 visitor.visit_expr(input)
787 for output in &ia.outputs {
788 visitor.visit_expr(&output.expr)
791 ExprKind::Yield(ref optional_expression) => {
792 walk_list!(visitor, visit_expr, optional_expression);
794 ExprKind::Try(ref subexpression) => {
795 visitor.visit_expr(subexpression)
797 ExprKind::Catch(ref body) => {
798 visitor.visit_block(body)
802 visitor.visit_expr_post(expression)
805 pub fn walk_arm<'a, V: Visitor<'a>>(visitor: &mut V, arm: &'a Arm) {
806 walk_list!(visitor, visit_pat, &arm.pats);
807 walk_list!(visitor, visit_expr, &arm.guard);
808 visitor.visit_expr(&arm.body);
809 walk_list!(visitor, visit_attribute, &arm.attrs);
812 pub fn walk_vis<'a, V: Visitor<'a>>(visitor: &mut V, vis: &'a Visibility) {
813 if let VisibilityKind::Restricted { ref path, id } = vis.node {
814 visitor.visit_path(path, id);
818 pub fn walk_attribute<'a, V: Visitor<'a>>(visitor: &mut V, attr: &'a Attribute) {
819 visitor.visit_tts(attr.tokens.clone());
822 pub fn walk_tt<'a, V: Visitor<'a>>(visitor: &mut V, tt: TokenTree) {
824 TokenTree::Token(_, tok) => visitor.visit_token(tok),
825 TokenTree::Delimited(_, delimed) => visitor.visit_tts(delimed.stream()),
829 pub fn walk_tts<'a, V: Visitor<'a>>(visitor: &mut V, tts: TokenStream) {
830 for tt in tts.trees() {
831 visitor.visit_tt(tt);