1 //! HIR walker for walking the contents of nodes.
3 //! **For an overview of the visitor strategy, see the docs on the
4 //! `super::itemlikevisit::ItemLikeVisitor` trait.**
6 //! If you have decided to use this visitor, here are some general
7 //! notes on how to do so:
9 //! Each overridden visit method has full control over what
10 //! happens with its node, it can do its own traversal of the node's children,
11 //! call `intravisit::walk_*` to apply the default traversal algorithm, or prevent
12 //! deeper traversal by doing nothing.
14 //! When visiting the HIR, the contents of nested items are NOT visited
15 //! by default. This is different from the AST visitor, which does a deep walk.
16 //! Hence this module is called `intravisit`; see the method `visit_nested_item`
19 //! Note: it is an important invariant that the default visitor walks
20 //! the body of a function in "execution order" - more concretely, if
21 //! we consider the reverse post-order (RPO) of the CFG implied by the HIR,
22 //! then a pre-order traversal of the HIR is consistent with the CFG RPO
23 //! on the *initial CFG point* of each HIR node, while a post-order traversal
24 //! of the HIR is consistent with the CFG RPO on each *final CFG point* of
27 //! One thing that follows is that if HIR node A always starts/ends executing
28 //! before HIR node B, then A appears in traversal pre/postorder before B,
29 //! respectively. (This follows from RPO respecting CFG domination).
31 //! This order consistency is required in a few places in rustc, for
32 //! example generator inference, and possibly also HIR borrowck.
34 use syntax::ast::{NodeId, CRATE_NODE_ID, Ident, Name, Attribute};
37 use crate::hir::def::Def;
38 use crate::hir::map::Map;
39 use super::itemlikevisit::DeepVisitor;
41 #[derive(Copy, Clone)]
43 /// `#[xxx] pub async/const/extern "Abi" fn foo()`
44 ItemFn(Ident, &'a Generics, FnHeader, &'a Visibility, &'a [Attribute]),
47 Method(Ident, &'a MethodSig, Option<&'a Visibility>, &'a [Attribute]),
50 Closure(&'a [Attribute]),
54 pub fn attrs(&self) -> &'a [Attribute] {
56 FnKind::ItemFn(.., attrs) => attrs,
57 FnKind::Method(.., attrs) => attrs,
58 FnKind::Closure(attrs) => attrs,
63 /// Specifies what nested things a visitor wants to visit. The most
64 /// common choice is `OnlyBodies`, which will cause the visitor to
65 /// visit fn bodies for fns that it encounters, but skip over nested
68 /// See the comments on `ItemLikeVisitor` for more details on the overall
70 pub enum NestedVisitorMap<'this, 'tcx: 'this> {
71 /// Do not visit any nested things. When you add a new
72 /// "non-nested" thing, you will want to audit such uses to see if
73 /// they remain valid.
75 /// Use this if you are only walking some particular kind of tree
76 /// (i.e., a type, or fn signature) and you don't want to thread a
80 /// Do not visit nested item-like things, but visit nested things
81 /// that are inside of an item-like.
83 /// **This is the most common choice.** A very common pattern is
84 /// to use `visit_all_item_likes()` as an outer loop,
85 /// and to have the visitor that visits the contents of each item
86 /// using this setting.
87 OnlyBodies(&'this Map<'tcx>),
89 /// Visits all nested things, including item-likes.
91 /// **This is an unusual choice.** It is used when you want to
92 /// process everything within their lexical context. Typically you
93 /// kick off the visit by doing `walk_krate()`.
94 All(&'this Map<'tcx>),
97 impl<'this, 'tcx> NestedVisitorMap<'this, 'tcx> {
98 /// Returns the map to use for an "intra item-like" thing (if any).
99 /// E.g., function body.
100 pub fn intra(self) -> Option<&'this Map<'tcx>> {
102 NestedVisitorMap::None => None,
103 NestedVisitorMap::OnlyBodies(map) => Some(map),
104 NestedVisitorMap::All(map) => Some(map),
108 /// Returns the map to use for an "item-like" thing (if any).
109 /// E.g., item, impl-item.
110 pub fn inter(self) -> Option<&'this Map<'tcx>> {
112 NestedVisitorMap::None => None,
113 NestedVisitorMap::OnlyBodies(_) => None,
114 NestedVisitorMap::All(map) => Some(map),
119 /// Each method of the Visitor trait is a hook to be potentially
120 /// overridden. Each method's default implementation recursively visits
121 /// the substructure of the input via the corresponding `walk` method;
122 /// e.g., the `visit_mod` method by default calls `intravisit::walk_mod`.
124 /// Note that this visitor does NOT visit nested items by default
125 /// (this is why the module is called `intravisit`, to distinguish it
126 /// from the AST's `visit` module, which acts differently). If you
127 /// simply want to visit all items in the crate in some order, you
128 /// should call `Crate::visit_all_items`. Otherwise, see the comment
129 /// on `visit_nested_item` for details on how to visit nested items.
131 /// If you want to ensure that your code handles every variant
132 /// explicitly, you need to override each method. (And you also need
133 /// to monitor future changes to `Visitor` in case a new method with a
134 /// new default implementation gets introduced.)
135 pub trait Visitor<'v> : Sized {
136 ///////////////////////////////////////////////////////////////////////////
139 /// The default versions of the `visit_nested_XXX` routines invoke
140 /// this method to get a map to use. By selecting an enum variant,
141 /// you control which kinds of nested HIR are visited; see
142 /// `NestedVisitorMap` for details. By "nested HIR", we are
143 /// referring to bits of HIR that are not directly embedded within
144 /// one another but rather indirectly, through a table in the
145 /// crate. This is done to control dependencies during incremental
146 /// compilation: the non-inline bits of HIR can be tracked and
147 /// hashed separately.
149 /// **If for some reason you want the nested behavior, but don't
150 /// have a `Map` at your disposal:** then you should override the
151 /// `visit_nested_XXX` methods, and override this method to
152 /// `panic!()`. This way, if a new `visit_nested_XXX` variant is
153 /// added in the future, we will see the panic in your code and
154 /// fix it appropriately.
155 fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'v>;
157 /// Invoked when a nested item is encountered. By default does
158 /// nothing unless you override `nested_visit_map` to return
159 /// `Some(_)`, in which case it will walk the item. **You probably
160 /// don't want to override this method** -- instead, override
161 /// `nested_visit_map` or use the "shallow" or "deep" visit
162 /// patterns described on `itemlikevisit::ItemLikeVisitor`. The only
163 /// reason to override this method is if you want a nested pattern
164 /// but cannot supply a `Map`; see `nested_visit_map` for advice.
165 #[allow(unused_variables)]
166 fn visit_nested_item(&mut self, id: ItemId) {
167 let opt_item = self.nested_visit_map().inter().map(|map| map.expect_item(id.id));
168 if let Some(item) = opt_item {
169 self.visit_item(item);
173 /// Like `visit_nested_item()`, but for trait items. See
174 /// `visit_nested_item()` for advice on when to override this
176 #[allow(unused_variables)]
177 fn visit_nested_trait_item(&mut self, id: TraitItemId) {
178 let opt_item = self.nested_visit_map().inter().map(|map| map.trait_item(id));
179 if let Some(item) = opt_item {
180 self.visit_trait_item(item);
184 /// Like `visit_nested_item()`, but for impl items. See
185 /// `visit_nested_item()` for advice on when to override this
187 #[allow(unused_variables)]
188 fn visit_nested_impl_item(&mut self, id: ImplItemId) {
189 let opt_item = self.nested_visit_map().inter().map(|map| map.impl_item(id));
190 if let Some(item) = opt_item {
191 self.visit_impl_item(item);
195 /// Invoked to visit the body of a function, method or closure. Like
196 /// visit_nested_item, does nothing by default unless you override
197 /// `nested_visit_map` to return `Some(_)`, in which case it will walk the
199 fn visit_nested_body(&mut self, id: BodyId) {
200 let opt_body = self.nested_visit_map().intra().map(|map| map.body(id));
201 if let Some(body) = opt_body {
202 self.visit_body(body);
206 /// Visits the top-level item and (optionally) nested items / impl items. See
207 /// `visit_nested_item` for details.
208 fn visit_item(&mut self, i: &'v Item) {
212 fn visit_body(&mut self, b: &'v Body) {
216 /// When invoking `visit_all_item_likes()`, you need to supply an
217 /// item-like visitor. This method converts a "intra-visit"
218 /// visitor into an item-like visitor that walks the entire tree.
219 /// If you use this, you probably don't want to process the
220 /// contents of nested item-like things, since the outer loop will
221 /// visit them as well.
222 fn as_deep_visitor<'s>(&'s mut self) -> DeepVisitor<'s, Self> {
223 DeepVisitor::new(self)
226 ///////////////////////////////////////////////////////////////////////////
228 fn visit_id(&mut self, _node_id: NodeId) {
231 fn visit_def_mention(&mut self, _def: Def) {
234 fn visit_name(&mut self, _span: Span, _name: Name) {
237 fn visit_ident(&mut self, ident: Ident) {
238 walk_ident(self, ident)
240 fn visit_mod(&mut self, m: &'v Mod, _s: Span, n: NodeId) {
243 fn visit_foreign_item(&mut self, i: &'v ForeignItem) {
244 walk_foreign_item(self, i)
246 fn visit_local(&mut self, l: &'v Local) {
249 fn visit_block(&mut self, b: &'v Block) {
252 fn visit_stmt(&mut self, s: &'v Stmt) {
255 fn visit_arm(&mut self, a: &'v Arm) {
258 fn visit_pat(&mut self, p: &'v Pat) {
261 fn visit_anon_const(&mut self, c: &'v AnonConst) {
262 walk_anon_const(self, c)
264 fn visit_expr(&mut self, ex: &'v Expr) {
267 fn visit_ty(&mut self, t: &'v Ty) {
270 fn visit_generic_param(&mut self, p: &'v GenericParam) {
271 walk_generic_param(self, p)
273 fn visit_generics(&mut self, g: &'v Generics) {
274 walk_generics(self, g)
276 fn visit_where_predicate(&mut self, predicate: &'v WherePredicate) {
277 walk_where_predicate(self, predicate)
279 fn visit_fn_decl(&mut self, fd: &'v FnDecl) {
280 walk_fn_decl(self, fd)
282 fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl, b: BodyId, s: Span, id: NodeId) {
283 walk_fn(self, fk, fd, b, s, id)
285 fn visit_use(&mut self, path: &'v Path, id: NodeId, hir_id: HirId) {
286 walk_use(self, path, id, hir_id)
288 fn visit_trait_item(&mut self, ti: &'v TraitItem) {
289 walk_trait_item(self, ti)
291 fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) {
292 walk_trait_item_ref(self, ii)
294 fn visit_impl_item(&mut self, ii: &'v ImplItem) {
295 walk_impl_item(self, ii)
297 fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef) {
298 walk_impl_item_ref(self, ii)
300 fn visit_trait_ref(&mut self, t: &'v TraitRef) {
301 walk_trait_ref(self, t)
303 fn visit_param_bound(&mut self, bounds: &'v GenericBound) {
304 walk_param_bound(self, bounds)
306 fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef, m: TraitBoundModifier) {
307 walk_poly_trait_ref(self, t, m)
309 fn visit_variant_data(&mut self,
315 walk_struct_def(self, s)
317 fn visit_struct_field(&mut self, s: &'v StructField) {
318 walk_struct_field(self, s)
320 fn visit_enum_def(&mut self,
321 enum_definition: &'v EnumDef,
322 generics: &'v Generics,
325 walk_enum_def(self, enum_definition, generics, item_id)
327 fn visit_variant(&mut self, v: &'v Variant, g: &'v Generics, item_id: NodeId) {
328 walk_variant(self, v, g, item_id)
330 fn visit_label(&mut self, label: &'v Label) {
331 walk_label(self, label)
333 fn visit_generic_arg(&mut self, generic_arg: &'v GenericArg) {
335 GenericArg::Lifetime(lt) => self.visit_lifetime(lt),
336 GenericArg::Type(ty) => self.visit_ty(ty),
337 GenericArg::Const(ct) => self.visit_anon_const(&ct.value),
340 fn visit_lifetime(&mut self, lifetime: &'v Lifetime) {
341 walk_lifetime(self, lifetime)
343 fn visit_qpath(&mut self, qpath: &'v QPath, id: HirId, span: Span) {
344 walk_qpath(self, qpath, id, span)
346 fn visit_path(&mut self, path: &'v Path, _id: HirId) {
347 walk_path(self, path)
349 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment) {
350 walk_path_segment(self, path_span, path_segment)
352 fn visit_generic_args(&mut self, path_span: Span, generic_args: &'v GenericArgs) {
353 walk_generic_args(self, path_span, generic_args)
355 fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding) {
356 walk_assoc_type_binding(self, type_binding)
358 fn visit_attribute(&mut self, _attr: &'v Attribute) {
360 fn visit_macro_def(&mut self, macro_def: &'v MacroDef) {
361 walk_macro_def(self, macro_def)
363 fn visit_vis(&mut self, vis: &'v Visibility) {
366 fn visit_associated_item_kind(&mut self, kind: &'v AssociatedItemKind) {
367 walk_associated_item_kind(self, kind);
369 fn visit_defaultness(&mut self, defaultness: &'v Defaultness) {
370 walk_defaultness(self, defaultness);
374 /// Walks the contents of a crate. See also `Crate::visit_all_items`.
375 pub fn walk_crate<'v, V: Visitor<'v>>(visitor: &mut V, krate: &'v Crate) {
376 visitor.visit_mod(&krate.module, krate.span, CRATE_NODE_ID);
377 walk_list!(visitor, visit_attribute, &krate.attrs);
378 walk_list!(visitor, visit_macro_def, &krate.exported_macros);
381 pub fn walk_macro_def<'v, V: Visitor<'v>>(visitor: &mut V, macro_def: &'v MacroDef) {
382 visitor.visit_id(macro_def.id);
383 visitor.visit_name(macro_def.span, macro_def.name);
384 walk_list!(visitor, visit_attribute, ¯o_def.attrs);
387 pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod, mod_node_id: NodeId) {
388 visitor.visit_id(mod_node_id);
389 for &item_id in &module.item_ids {
390 visitor.visit_nested_item(item_id);
394 pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body) {
395 for argument in &body.arguments {
396 visitor.visit_id(argument.id);
397 visitor.visit_pat(&argument.pat);
399 visitor.visit_expr(&body.value);
402 pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local) {
403 // Intentionally visiting the expr first - the initialization expr
404 // dominates the local's definition.
405 walk_list!(visitor, visit_expr, &local.init);
406 walk_list!(visitor, visit_attribute, local.attrs.iter());
407 visitor.visit_id(local.id);
408 visitor.visit_pat(&local.pat);
409 walk_list!(visitor, visit_ty, &local.ty);
412 pub fn walk_ident<'v, V: Visitor<'v>>(visitor: &mut V, ident: Ident) {
413 visitor.visit_name(ident.span, ident.name);
416 pub fn walk_label<'v, V: Visitor<'v>>(visitor: &mut V, label: &'v Label) {
417 visitor.visit_ident(label.ident);
420 pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) {
421 visitor.visit_id(lifetime.id);
422 match lifetime.name {
423 LifetimeName::Param(ParamName::Plain(ident)) => {
424 visitor.visit_ident(ident);
426 LifetimeName::Param(ParamName::Fresh(_)) |
427 LifetimeName::Param(ParamName::Error) |
428 LifetimeName::Static |
429 LifetimeName::Error |
430 LifetimeName::Implicit |
431 LifetimeName::Underscore => {}
435 pub fn walk_poly_trait_ref<'v, V>(visitor: &mut V,
436 trait_ref: &'v PolyTraitRef,
437 _modifier: TraitBoundModifier)
440 walk_list!(visitor, visit_generic_param, &trait_ref.bound_generic_params);
441 visitor.visit_trait_ref(&trait_ref.trait_ref);
444 pub fn walk_trait_ref<'v, V>(visitor: &mut V, trait_ref: &'v TraitRef)
447 visitor.visit_id(trait_ref.ref_id);
448 visitor.visit_path(&trait_ref.path, trait_ref.hir_ref_id)
451 pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {
452 visitor.visit_vis(&item.vis);
453 visitor.visit_ident(item.ident);
455 ItemKind::ExternCrate(orig_name) => {
456 visitor.visit_id(item.id);
457 if let Some(orig_name) = orig_name {
458 visitor.visit_name(item.span, orig_name);
461 ItemKind::Use(ref path, _) => {
462 visitor.visit_use(path, item.id, item.hir_id);
464 ItemKind::Static(ref typ, _, body) |
465 ItemKind::Const(ref typ, body) => {
466 visitor.visit_id(item.id);
467 visitor.visit_ty(typ);
468 visitor.visit_nested_body(body);
470 ItemKind::Fn(ref declaration, header, ref generics, body_id) => {
471 visitor.visit_fn(FnKind::ItemFn(item.ident,
481 ItemKind::Mod(ref module) => {
482 // `visit_mod()` takes care of visiting the `Item`'s `NodeId`.
483 visitor.visit_mod(module, item.span, item.id)
485 ItemKind::ForeignMod(ref foreign_module) => {
486 visitor.visit_id(item.id);
487 walk_list!(visitor, visit_foreign_item, &foreign_module.items);
489 ItemKind::GlobalAsm(_) => {
490 visitor.visit_id(item.id);
492 ItemKind::Ty(ref typ, ref type_parameters) => {
493 visitor.visit_id(item.id);
494 visitor.visit_ty(typ);
495 visitor.visit_generics(type_parameters)
497 ItemKind::Existential(ExistTy {ref generics, ref bounds, impl_trait_fn}) => {
498 visitor.visit_id(item.id);
499 walk_generics(visitor, generics);
500 walk_list!(visitor, visit_param_bound, bounds);
501 if let Some(impl_trait_fn) = impl_trait_fn {
502 visitor.visit_def_mention(Def::Fn(impl_trait_fn))
505 ItemKind::Enum(ref enum_definition, ref type_parameters) => {
506 visitor.visit_generics(type_parameters);
507 // `visit_enum_def()` takes care of visiting the `Item`'s `NodeId`.
508 visitor.visit_enum_def(enum_definition, type_parameters, item.id, item.span)
513 ref opt_trait_reference,
517 visitor.visit_id(item.id);
518 visitor.visit_generics(type_parameters);
519 walk_list!(visitor, visit_trait_ref, opt_trait_reference);
520 visitor.visit_ty(typ);
521 walk_list!(visitor, visit_impl_item_ref, impl_item_refs);
523 ItemKind::Struct(ref struct_definition, ref generics) |
524 ItemKind::Union(ref struct_definition, ref generics) => {
525 visitor.visit_generics(generics);
526 visitor.visit_id(item.id);
527 visitor.visit_variant_data(struct_definition, item.ident.name, generics, item.id,
530 ItemKind::Trait(.., ref generics, ref bounds, ref trait_item_refs) => {
531 visitor.visit_id(item.id);
532 visitor.visit_generics(generics);
533 walk_list!(visitor, visit_param_bound, bounds);
534 walk_list!(visitor, visit_trait_item_ref, trait_item_refs);
536 ItemKind::TraitAlias(ref generics, ref bounds) => {
537 visitor.visit_id(item.id);
538 visitor.visit_generics(generics);
539 walk_list!(visitor, visit_param_bound, bounds);
542 walk_list!(visitor, visit_attribute, &item.attrs);
545 pub fn walk_use<'v, V: Visitor<'v>>(visitor: &mut V,
549 visitor.visit_id(item_id);
550 visitor.visit_path(path, hir_id);
553 pub fn walk_enum_def<'v, V: Visitor<'v>>(visitor: &mut V,
554 enum_definition: &'v EnumDef,
555 generics: &'v Generics,
557 visitor.visit_id(item_id);
560 &enum_definition.variants,
565 pub fn walk_variant<'v, V: Visitor<'v>>(visitor: &mut V,
566 variant: &'v Variant,
567 generics: &'v Generics,
568 parent_item_id: NodeId) {
569 visitor.visit_ident(variant.node.ident);
570 visitor.visit_variant_data(&variant.node.data,
571 variant.node.ident.name,
575 walk_list!(visitor, visit_anon_const, &variant.node.disr_expr);
576 walk_list!(visitor, visit_attribute, &variant.node.attrs);
579 pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty) {
580 visitor.visit_id(typ.id);
583 TyKind::Slice(ref ty) => {
586 TyKind::Ptr(ref mutable_type) => {
587 visitor.visit_ty(&mutable_type.ty)
589 TyKind::Rptr(ref lifetime, ref mutable_type) => {
590 visitor.visit_lifetime(lifetime);
591 visitor.visit_ty(&mutable_type.ty)
594 TyKind::Tup(ref tuple_element_types) => {
595 walk_list!(visitor, visit_ty, tuple_element_types);
597 TyKind::BareFn(ref function_declaration) => {
598 walk_list!(visitor, visit_generic_param, &function_declaration.generic_params);
599 visitor.visit_fn_decl(&function_declaration.decl);
601 TyKind::Path(ref qpath) => {
602 visitor.visit_qpath(qpath, typ.hir_id, typ.span);
604 TyKind::Def(item_id, ref lifetimes) => {
605 visitor.visit_nested_item(item_id);
606 walk_list!(visitor, visit_generic_arg, lifetimes);
608 TyKind::Array(ref ty, ref length) => {
609 visitor.visit_ty(ty);
610 visitor.visit_anon_const(length)
612 TyKind::TraitObject(ref bounds, ref lifetime) => {
613 for bound in bounds {
614 visitor.visit_poly_trait_ref(bound, TraitBoundModifier::None);
616 visitor.visit_lifetime(lifetime);
618 TyKind::Typeof(ref expression) => {
619 visitor.visit_anon_const(expression)
621 TyKind::Infer | TyKind::Err => {}
625 pub fn walk_qpath<'v, V: Visitor<'v>>(visitor: &mut V, qpath: &'v QPath, id: HirId, span: Span) {
627 QPath::Resolved(ref maybe_qself, ref path) => {
628 if let Some(ref qself) = *maybe_qself {
629 visitor.visit_ty(qself);
631 visitor.visit_path(path, id)
633 QPath::TypeRelative(ref qself, ref segment) => {
634 visitor.visit_ty(qself);
635 visitor.visit_path_segment(span, segment);
640 pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path) {
641 visitor.visit_def_mention(path.def);
642 for segment in &path.segments {
643 visitor.visit_path_segment(path.span, segment);
647 pub fn walk_path_segment<'v, V: Visitor<'v>>(visitor: &mut V,
649 segment: &'v PathSegment) {
650 visitor.visit_ident(segment.ident);
651 if let Some(id) = segment.id {
652 visitor.visit_id(id);
654 if let Some(ref args) = segment.args {
655 visitor.visit_generic_args(path_span, args);
659 pub fn walk_generic_args<'v, V: Visitor<'v>>(visitor: &mut V,
661 generic_args: &'v GenericArgs) {
662 walk_list!(visitor, visit_generic_arg, &generic_args.args);
663 walk_list!(visitor, visit_assoc_type_binding, &generic_args.bindings);
666 pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(visitor: &mut V,
667 type_binding: &'v TypeBinding) {
668 visitor.visit_id(type_binding.id);
669 visitor.visit_ident(type_binding.ident);
670 visitor.visit_ty(&type_binding.ty);
673 pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat) {
674 visitor.visit_id(pattern.id);
676 PatKind::TupleStruct(ref qpath, ref children, _) => {
677 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
678 walk_list!(visitor, visit_pat, children);
680 PatKind::Path(ref qpath) => {
681 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
683 PatKind::Struct(ref qpath, ref fields, _) => {
684 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
685 for field in fields {
686 visitor.visit_id(field.node.id);
687 visitor.visit_ident(field.node.ident);
688 visitor.visit_pat(&field.node.pat)
691 PatKind::Tuple(ref tuple_elements, _) => {
692 walk_list!(visitor, visit_pat, tuple_elements);
694 PatKind::Box(ref subpattern) |
695 PatKind::Ref(ref subpattern, _) => {
696 visitor.visit_pat(subpattern)
698 PatKind::Binding(_, canonical_id, _hir_id, ident, ref optional_subpattern) => {
699 visitor.visit_def_mention(Def::Local(canonical_id));
700 visitor.visit_ident(ident);
701 walk_list!(visitor, visit_pat, optional_subpattern);
703 PatKind::Lit(ref expression) => visitor.visit_expr(expression),
704 PatKind::Range(ref lower_bound, ref upper_bound, _) => {
705 visitor.visit_expr(lower_bound);
706 visitor.visit_expr(upper_bound)
709 PatKind::Slice(ref prepatterns, ref slice_pattern, ref postpatterns) => {
710 walk_list!(visitor, visit_pat, prepatterns);
711 walk_list!(visitor, visit_pat, slice_pattern);
712 walk_list!(visitor, visit_pat, postpatterns);
717 pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V, foreign_item: &'v ForeignItem) {
718 visitor.visit_id(foreign_item.id);
719 visitor.visit_vis(&foreign_item.vis);
720 visitor.visit_ident(foreign_item.ident);
722 match foreign_item.node {
723 ForeignItemKind::Fn(ref function_declaration, ref param_names, ref generics) => {
724 visitor.visit_generics(generics);
725 visitor.visit_fn_decl(function_declaration);
726 for ¶m_name in param_names {
727 visitor.visit_ident(param_name);
730 ForeignItemKind::Static(ref typ, _) => visitor.visit_ty(typ),
731 ForeignItemKind::Type => (),
734 walk_list!(visitor, visit_attribute, &foreign_item.attrs);
737 pub fn walk_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v GenericBound) {
739 GenericBound::Trait(ref typ, modifier) => {
740 visitor.visit_poly_trait_ref(typ, modifier);
742 GenericBound::Outlives(ref lifetime) => visitor.visit_lifetime(lifetime),
746 pub fn walk_generic_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v GenericParam) {
747 visitor.visit_id(param.id);
748 walk_list!(visitor, visit_attribute, ¶m.attrs);
750 ParamName::Plain(ident) => visitor.visit_ident(ident),
751 ParamName::Error | ParamName::Fresh(_) => {}
754 GenericParamKind::Lifetime { .. } => {}
755 GenericParamKind::Type { ref default, .. } => walk_list!(visitor, visit_ty, default),
756 GenericParamKind::Const { ref ty } => visitor.visit_ty(ty),
758 walk_list!(visitor, visit_param_bound, ¶m.bounds);
761 pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics) {
762 walk_list!(visitor, visit_generic_param, &generics.params);
763 visitor.visit_id(generics.where_clause.id);
764 walk_list!(visitor, visit_where_predicate, &generics.where_clause.predicates);
767 pub fn walk_where_predicate<'v, V: Visitor<'v>>(
769 predicate: &'v WherePredicate)
772 &WherePredicate::BoundPredicate(WhereBoundPredicate{ref bounded_ty,
774 ref bound_generic_params,
776 visitor.visit_ty(bounded_ty);
777 walk_list!(visitor, visit_param_bound, bounds);
778 walk_list!(visitor, visit_generic_param, bound_generic_params);
780 &WherePredicate::RegionPredicate(WhereRegionPredicate{ref lifetime,
783 visitor.visit_lifetime(lifetime);
784 walk_list!(visitor, visit_param_bound, bounds);
786 &WherePredicate::EqPredicate(WhereEqPredicate{id,
790 visitor.visit_id(id);
791 visitor.visit_ty(lhs_ty);
792 visitor.visit_ty(rhs_ty);
797 pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FunctionRetTy) {
798 if let Return(ref output_ty) = *ret_ty {
799 visitor.visit_ty(output_ty)
803 pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl) {
804 for ty in &function_declaration.inputs {
807 walk_fn_ret_ty(visitor, &function_declaration.output)
810 pub fn walk_fn_kind<'v, V: Visitor<'v>>(visitor: &mut V, function_kind: FnKind<'v>) {
811 match function_kind {
812 FnKind::ItemFn(_, generics, ..) => {
813 visitor.visit_generics(generics);
816 FnKind::Closure(_) => {}
820 pub fn walk_fn<'v, V: Visitor<'v>>(visitor: &mut V,
821 function_kind: FnKind<'v>,
822 function_declaration: &'v FnDecl,
826 visitor.visit_id(id);
827 visitor.visit_fn_decl(function_declaration);
828 walk_fn_kind(visitor, function_kind);
829 visitor.visit_nested_body(body_id)
832 pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem) {
833 visitor.visit_ident(trait_item.ident);
834 walk_list!(visitor, visit_attribute, &trait_item.attrs);
835 visitor.visit_generics(&trait_item.generics);
836 match trait_item.node {
837 TraitItemKind::Const(ref ty, default) => {
838 visitor.visit_id(trait_item.id);
839 visitor.visit_ty(ty);
840 walk_list!(visitor, visit_nested_body, default);
842 TraitItemKind::Method(ref sig, TraitMethod::Required(ref param_names)) => {
843 visitor.visit_id(trait_item.id);
844 visitor.visit_fn_decl(&sig.decl);
845 for ¶m_name in param_names {
846 visitor.visit_ident(param_name);
849 TraitItemKind::Method(ref sig, TraitMethod::Provided(body_id)) => {
850 visitor.visit_fn(FnKind::Method(trait_item.ident,
859 TraitItemKind::Type(ref bounds, ref default) => {
860 visitor.visit_id(trait_item.id);
861 walk_list!(visitor, visit_param_bound, bounds);
862 walk_list!(visitor, visit_ty, default);
867 pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref: &'v TraitItemRef) {
868 // N.B., deliberately force a compilation error if/when new fields are added.
869 let TraitItemRef { id, ident, ref kind, span: _, ref defaultness } = *trait_item_ref;
870 visitor.visit_nested_trait_item(id);
871 visitor.visit_ident(ident);
872 visitor.visit_associated_item_kind(kind);
873 visitor.visit_defaultness(defaultness);
876 pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem) {
877 // N.B., deliberately force a compilation error if/when new fields are added.
890 visitor.visit_ident(ident);
891 visitor.visit_vis(vis);
892 visitor.visit_defaultness(defaultness);
893 walk_list!(visitor, visit_attribute, attrs);
894 visitor.visit_generics(generics);
896 ImplItemKind::Const(ref ty, body) => {
897 visitor.visit_id(impl_item.id);
898 visitor.visit_ty(ty);
899 visitor.visit_nested_body(body);
901 ImplItemKind::Method(ref sig, body_id) => {
902 visitor.visit_fn(FnKind::Method(impl_item.ident,
904 Some(&impl_item.vis),
911 ImplItemKind::Type(ref ty) => {
912 visitor.visit_id(impl_item.id);
913 visitor.visit_ty(ty);
915 ImplItemKind::Existential(ref bounds) => {
916 visitor.visit_id(impl_item.id);
917 walk_list!(visitor, visit_param_bound, bounds);
922 pub fn walk_impl_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, impl_item_ref: &'v ImplItemRef) {
923 // N.B., deliberately force a compilation error if/when new fields are added.
924 let ImplItemRef { id, ident, ref kind, span: _, ref vis, ref defaultness } = *impl_item_ref;
925 visitor.visit_nested_impl_item(id);
926 visitor.visit_ident(ident);
927 visitor.visit_associated_item_kind(kind);
928 visitor.visit_vis(vis);
929 visitor.visit_defaultness(defaultness);
933 pub fn walk_struct_def<'v, V: Visitor<'v>>(visitor: &mut V, struct_definition: &'v VariantData) {
934 visitor.visit_id(struct_definition.id());
935 walk_list!(visitor, visit_struct_field, struct_definition.fields());
938 pub fn walk_struct_field<'v, V: Visitor<'v>>(visitor: &mut V, struct_field: &'v StructField) {
939 visitor.visit_id(struct_field.id);
940 visitor.visit_vis(&struct_field.vis);
941 visitor.visit_ident(struct_field.ident);
942 visitor.visit_ty(&struct_field.ty);
943 walk_list!(visitor, visit_attribute, &struct_field.attrs);
946 pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block) {
947 visitor.visit_id(block.id);
948 walk_list!(visitor, visit_stmt, &block.stmts);
949 walk_list!(visitor, visit_expr, &block.expr);
952 pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt) {
953 visitor.visit_id(statement.id);
954 match statement.node {
955 StmtKind::Local(ref local) => visitor.visit_local(local),
956 StmtKind::Item(ref item) => visitor.visit_nested_item(**item),
957 StmtKind::Expr(ref expression) |
958 StmtKind::Semi(ref expression) => {
959 visitor.visit_expr(expression)
964 pub fn walk_anon_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v AnonConst) {
965 visitor.visit_id(constant.id);
966 visitor.visit_nested_body(constant.body);
969 pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr) {
970 visitor.visit_id(expression.id);
971 walk_list!(visitor, visit_attribute, expression.attrs.iter());
972 match expression.node {
973 ExprKind::Box(ref subexpression) => {
974 visitor.visit_expr(subexpression)
976 ExprKind::Array(ref subexpressions) => {
977 walk_list!(visitor, visit_expr, subexpressions);
979 ExprKind::Repeat(ref element, ref count) => {
980 visitor.visit_expr(element);
981 visitor.visit_anon_const(count)
983 ExprKind::Struct(ref qpath, ref fields, ref optional_base) => {
984 visitor.visit_qpath(qpath, expression.hir_id, expression.span);
985 for field in fields {
986 visitor.visit_id(field.id);
987 visitor.visit_ident(field.ident);
988 visitor.visit_expr(&field.expr)
990 walk_list!(visitor, visit_expr, optional_base);
992 ExprKind::Tup(ref subexpressions) => {
993 walk_list!(visitor, visit_expr, subexpressions);
995 ExprKind::Call(ref callee_expression, ref arguments) => {
996 visitor.visit_expr(callee_expression);
997 walk_list!(visitor, visit_expr, arguments);
999 ExprKind::MethodCall(ref segment, _, ref arguments) => {
1000 visitor.visit_path_segment(expression.span, segment);
1001 walk_list!(visitor, visit_expr, arguments);
1003 ExprKind::Binary(_, ref left_expression, ref right_expression) => {
1004 visitor.visit_expr(left_expression);
1005 visitor.visit_expr(right_expression)
1007 ExprKind::AddrOf(_, ref subexpression) | ExprKind::Unary(_, ref subexpression) => {
1008 visitor.visit_expr(subexpression)
1010 ExprKind::Lit(_) => {}
1011 ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => {
1012 visitor.visit_expr(subexpression);
1013 visitor.visit_ty(typ)
1015 ExprKind::If(ref head_expression, ref if_block, ref optional_else) => {
1016 visitor.visit_expr(head_expression);
1017 visitor.visit_expr(if_block);
1018 walk_list!(visitor, visit_expr, optional_else);
1020 ExprKind::While(ref subexpression, ref block, ref opt_label) => {
1021 walk_list!(visitor, visit_label, opt_label);
1022 visitor.visit_expr(subexpression);
1023 visitor.visit_block(block);
1025 ExprKind::Loop(ref block, ref opt_label, _) => {
1026 walk_list!(visitor, visit_label, opt_label);
1027 visitor.visit_block(block);
1029 ExprKind::Match(ref subexpression, ref arms, _) => {
1030 visitor.visit_expr(subexpression);
1031 walk_list!(visitor, visit_arm, arms);
1033 ExprKind::Closure(_, ref function_declaration, body, _fn_decl_span, _gen) => {
1034 visitor.visit_fn(FnKind::Closure(&expression.attrs),
1035 function_declaration,
1040 ExprKind::Block(ref block, ref opt_label) => {
1041 walk_list!(visitor, visit_label, opt_label);
1042 visitor.visit_block(block);
1044 ExprKind::Assign(ref left_hand_expression, ref right_hand_expression) => {
1045 visitor.visit_expr(right_hand_expression);
1046 visitor.visit_expr(left_hand_expression)
1048 ExprKind::AssignOp(_, ref left_expression, ref right_expression) => {
1049 visitor.visit_expr(right_expression);
1050 visitor.visit_expr(left_expression)
1052 ExprKind::Field(ref subexpression, ident) => {
1053 visitor.visit_expr(subexpression);
1054 visitor.visit_ident(ident);
1056 ExprKind::Index(ref main_expression, ref index_expression) => {
1057 visitor.visit_expr(main_expression);
1058 visitor.visit_expr(index_expression)
1060 ExprKind::Path(ref qpath) => {
1061 visitor.visit_qpath(qpath, expression.hir_id, expression.span);
1063 ExprKind::Break(ref destination, ref opt_expr) => {
1064 if let Some(ref label) = destination.label {
1065 visitor.visit_label(label);
1066 if let Ok(node_id) = destination.target_id {
1067 visitor.visit_def_mention(Def::Label(node_id))
1070 walk_list!(visitor, visit_expr, opt_expr);
1072 ExprKind::Continue(ref destination) => {
1073 if let Some(ref label) = destination.label {
1074 visitor.visit_label(label);
1075 if let Ok(node_id) = destination.target_id {
1076 visitor.visit_def_mention(Def::Label(node_id))
1080 ExprKind::Ret(ref optional_expression) => {
1081 walk_list!(visitor, visit_expr, optional_expression);
1083 ExprKind::InlineAsm(_, ref outputs, ref inputs) => {
1084 for expr in outputs.iter().chain(inputs.iter()) {
1085 visitor.visit_expr(expr)
1088 ExprKind::Yield(ref subexpression) => {
1089 visitor.visit_expr(subexpression);
1095 pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm) {
1096 walk_list!(visitor, visit_pat, &arm.pats);
1097 if let Some(ref g) = arm.guard {
1099 Guard::If(ref e) => visitor.visit_expr(e),
1102 visitor.visit_expr(&arm.body);
1103 walk_list!(visitor, visit_attribute, &arm.attrs);
1106 pub fn walk_vis<'v, V: Visitor<'v>>(visitor: &mut V, vis: &'v Visibility) {
1107 if let VisibilityKind::Restricted { ref path, id, hir_id } = vis.node {
1108 visitor.visit_id(id);
1109 visitor.visit_path(path, hir_id)
1113 pub fn walk_associated_item_kind<'v, V: Visitor<'v>>(_: &mut V, _: &'v AssociatedItemKind) {
1114 // No visitable content here: this fn exists so you can call it if
1115 // the right thing to do, should content be added in the future,
1116 // would be to walk it.
1119 pub fn walk_defaultness<'v, V: Visitor<'v>>(_: &mut V, _: &'v Defaultness) {
1120 // No visitable content here: this fn exists so you can call it if
1121 // the right thing to do, should content be added in the future,
1122 // would be to walk it.