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.
35 use crate::hir_id::CRATE_HIR_ID;
36 use crate::itemlikevisit::{ItemLikeVisitor, ParItemLikeVisitor};
37 use rustc_ast::walk_list;
38 use rustc_ast::{Attribute, Label};
39 use rustc_span::symbol::{Ident, Symbol};
42 pub struct DeepVisitor<'v, V> {
46 impl<'v, V> DeepVisitor<'v, V> {
47 pub fn new(base: &'v mut V) -> Self {
48 DeepVisitor { visitor: base }
52 impl<'v, 'hir, V> ItemLikeVisitor<'hir> for DeepVisitor<'v, V>
56 fn visit_item(&mut self, item: &'hir Item<'hir>) {
57 self.visitor.visit_item(item);
60 fn visit_trait_item(&mut self, trait_item: &'hir TraitItem<'hir>) {
61 self.visitor.visit_trait_item(trait_item);
64 fn visit_impl_item(&mut self, impl_item: &'hir ImplItem<'hir>) {
65 self.visitor.visit_impl_item(impl_item);
69 pub trait IntoVisitor<'hir> {
70 type Visitor: Visitor<'hir>;
71 fn into_visitor(&self) -> Self::Visitor;
74 pub struct ParDeepVisitor<V>(pub V);
76 impl<'hir, V> ParItemLikeVisitor<'hir> for ParDeepVisitor<V>
80 fn visit_item(&self, item: &'hir Item<'hir>) {
81 self.0.into_visitor().visit_item(item);
84 fn visit_trait_item(&self, trait_item: &'hir TraitItem<'hir>) {
85 self.0.into_visitor().visit_trait_item(trait_item);
88 fn visit_impl_item(&self, impl_item: &'hir ImplItem<'hir>) {
89 self.0.into_visitor().visit_impl_item(impl_item);
93 #[derive(Copy, Clone)]
95 /// `#[xxx] pub async/const/extern "Abi" fn foo()`
96 ItemFn(Ident, &'a Generics<'a>, FnHeader, &'a Visibility<'a>, &'a [Attribute]),
99 Method(Ident, &'a FnSig<'a>, Option<&'a Visibility<'a>>, &'a [Attribute]),
102 Closure(&'a [Attribute]),
105 impl<'a> FnKind<'a> {
106 pub fn attrs(&self) -> &'a [Attribute] {
108 FnKind::ItemFn(.., attrs) => attrs,
109 FnKind::Method(.., attrs) => attrs,
110 FnKind::Closure(attrs) => attrs,
114 pub fn header(&self) -> Option<&FnHeader> {
116 FnKind::ItemFn(_, _, ref header, _, _) => Some(header),
117 FnKind::Method(_, ref sig, _, _) => Some(&sig.header),
118 FnKind::Closure(_) => None,
123 /// An abstract representation of the HIR `rustc_middle::hir::map::Map`.
124 pub trait Map<'hir> {
125 /// Retrieves the `Node` corresponding to `id`, returning `None` if cannot be found.
126 fn find(&self, hir_id: HirId) -> Option<Node<'hir>>;
127 fn body(&self, id: BodyId) -> &'hir Body<'hir>;
128 fn item(&self, id: HirId) -> &'hir Item<'hir>;
129 fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir>;
130 fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem<'hir>;
133 /// An erased version of `Map<'hir>`, using dynamic dispatch.
134 /// NOTE: This type is effectively only usable with `NestedVisitorMap::None`.
135 pub struct ErasedMap<'hir>(&'hir dyn Map<'hir>);
137 impl<'hir> Map<'hir> for ErasedMap<'hir> {
138 fn find(&self, _: HirId) -> Option<Node<'hir>> {
141 fn body(&self, id: BodyId) -> &'hir Body<'hir> {
144 fn item(&self, id: HirId) -> &'hir Item<'hir> {
147 fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir> {
148 self.0.trait_item(id)
150 fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem<'hir> {
155 /// Specifies what nested things a visitor wants to visit. The most
156 /// common choice is `OnlyBodies`, which will cause the visitor to
157 /// visit fn bodies for fns that it encounters, but skip over nested
158 /// item-like things.
160 /// See the comments on `ItemLikeVisitor` for more details on the overall
162 pub enum NestedVisitorMap<M> {
163 /// Do not visit any nested things. When you add a new
164 /// "non-nested" thing, you will want to audit such uses to see if
165 /// they remain valid.
167 /// Use this if you are only walking some particular kind of tree
168 /// (i.e., a type, or fn signature) and you don't want to thread a
172 /// Do not visit nested item-like things, but visit nested things
173 /// that are inside of an item-like.
175 /// **This is the most common choice.** A very common pattern is
176 /// to use `visit_all_item_likes()` as an outer loop,
177 /// and to have the visitor that visits the contents of each item
178 /// using this setting.
181 /// Visits all nested things, including item-likes.
183 /// **This is an unusual choice.** It is used when you want to
184 /// process everything within their lexical context. Typically you
185 /// kick off the visit by doing `walk_krate()`.
189 impl<M> NestedVisitorMap<M> {
190 /// Returns the map to use for an "intra item-like" thing (if any).
191 /// E.g., function body.
192 fn intra(self) -> Option<M> {
194 NestedVisitorMap::None => None,
195 NestedVisitorMap::OnlyBodies(map) => Some(map),
196 NestedVisitorMap::All(map) => Some(map),
200 /// Returns the map to use for an "item-like" thing (if any).
201 /// E.g., item, impl-item.
202 fn inter(self) -> Option<M> {
204 NestedVisitorMap::None => None,
205 NestedVisitorMap::OnlyBodies(_) => None,
206 NestedVisitorMap::All(map) => Some(map),
211 /// Each method of the Visitor trait is a hook to be potentially
212 /// overridden. Each method's default implementation recursively visits
213 /// the substructure of the input via the corresponding `walk` method;
214 /// e.g., the `visit_mod` method by default calls `intravisit::walk_mod`.
216 /// Note that this visitor does NOT visit nested items by default
217 /// (this is why the module is called `intravisit`, to distinguish it
218 /// from the AST's `visit` module, which acts differently). If you
219 /// simply want to visit all items in the crate in some order, you
220 /// should call `Crate::visit_all_items`. Otherwise, see the comment
221 /// on `visit_nested_item` for details on how to visit nested items.
223 /// If you want to ensure that your code handles every variant
224 /// explicitly, you need to override each method. (And you also need
225 /// to monitor future changes to `Visitor` in case a new method with a
226 /// new default implementation gets introduced.)
227 pub trait Visitor<'v>: Sized {
230 ///////////////////////////////////////////////////////////////////////////
233 /// The default versions of the `visit_nested_XXX` routines invoke
234 /// this method to get a map to use. By selecting an enum variant,
235 /// you control which kinds of nested HIR are visited; see
236 /// `NestedVisitorMap` for details. By "nested HIR", we are
237 /// referring to bits of HIR that are not directly embedded within
238 /// one another but rather indirectly, through a table in the
239 /// crate. This is done to control dependencies during incremental
240 /// compilation: the non-inline bits of HIR can be tracked and
241 /// hashed separately.
243 /// **If for some reason you want the nested behavior, but don't
244 /// have a `Map` at your disposal:** then you should override the
245 /// `visit_nested_XXX` methods, and override this method to
246 /// `panic!()`. This way, if a new `visit_nested_XXX` variant is
247 /// added in the future, we will see the panic in your code and
248 /// fix it appropriately.
249 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map>;
251 /// Invoked when a nested item is encountered. By default does
252 /// nothing unless you override `nested_visit_map` to return other than
253 /// `None`, in which case it will walk the item. **You probably
254 /// don't want to override this method** -- instead, override
255 /// `nested_visit_map` or use the "shallow" or "deep" visit
256 /// patterns described on `itemlikevisit::ItemLikeVisitor`. The only
257 /// reason to override this method is if you want a nested pattern
258 /// but cannot supply a `Map`; see `nested_visit_map` for advice.
259 #[allow(unused_variables)]
260 fn visit_nested_item(&mut self, id: ItemId) {
261 let opt_item = self.nested_visit_map().inter().map(|map| map.item(id.id));
262 walk_list!(self, visit_item, opt_item);
265 /// Like `visit_nested_item()`, but for trait items. See
266 /// `visit_nested_item()` for advice on when to override this
268 #[allow(unused_variables)]
269 fn visit_nested_trait_item(&mut self, id: TraitItemId) {
270 let opt_item = self.nested_visit_map().inter().map(|map| map.trait_item(id));
271 walk_list!(self, visit_trait_item, opt_item);
274 /// Like `visit_nested_item()`, but for impl items. See
275 /// `visit_nested_item()` for advice on when to override this
277 #[allow(unused_variables)]
278 fn visit_nested_impl_item(&mut self, id: ImplItemId) {
279 let opt_item = self.nested_visit_map().inter().map(|map| map.impl_item(id));
280 walk_list!(self, visit_impl_item, opt_item);
283 /// Invoked to visit the body of a function, method or closure. Like
284 /// visit_nested_item, does nothing by default unless you override
285 /// `nested_visit_map` to return other than `None`, in which case it will walk
287 fn visit_nested_body(&mut self, id: BodyId) {
288 let opt_body = self.nested_visit_map().intra().map(|map| map.body(id));
289 walk_list!(self, visit_body, opt_body);
292 fn visit_param(&mut self, param: &'v Param<'v>) {
293 walk_param(self, param)
296 /// Visits the top-level item and (optionally) nested items / impl items. See
297 /// `visit_nested_item` for details.
298 fn visit_item(&mut self, i: &'v Item<'v>) {
302 fn visit_body(&mut self, b: &'v Body<'v>) {
306 /// When invoking `visit_all_item_likes()`, you need to supply an
307 /// item-like visitor. This method converts a "intra-visit"
308 /// visitor into an item-like visitor that walks the entire tree.
309 /// If you use this, you probably don't want to process the
310 /// contents of nested item-like things, since the outer loop will
311 /// visit them as well.
312 fn as_deep_visitor(&mut self) -> DeepVisitor<'_, Self> {
313 DeepVisitor::new(self)
316 ///////////////////////////////////////////////////////////////////////////
318 fn visit_id(&mut self, _hir_id: HirId) {
321 fn visit_name(&mut self, _span: Span, _name: Symbol) {
324 fn visit_ident(&mut self, ident: Ident) {
325 walk_ident(self, ident)
327 fn visit_mod(&mut self, m: &'v Mod<'v>, _s: Span, n: HirId) {
330 fn visit_foreign_item(&mut self, i: &'v ForeignItem<'v>) {
331 walk_foreign_item(self, i)
333 fn visit_local(&mut self, l: &'v Local<'v>) {
336 fn visit_block(&mut self, b: &'v Block<'v>) {
339 fn visit_stmt(&mut self, s: &'v Stmt<'v>) {
342 fn visit_arm(&mut self, a: &'v Arm<'v>) {
345 fn visit_pat(&mut self, p: &'v Pat<'v>) {
348 fn visit_anon_const(&mut self, c: &'v AnonConst) {
349 walk_anon_const(self, c)
351 fn visit_expr(&mut self, ex: &'v Expr<'v>) {
354 fn visit_ty(&mut self, t: &'v Ty<'v>) {
357 fn visit_generic_param(&mut self, p: &'v GenericParam<'v>) {
358 walk_generic_param(self, p)
360 fn visit_generics(&mut self, g: &'v Generics<'v>) {
361 walk_generics(self, g)
363 fn visit_where_predicate(&mut self, predicate: &'v WherePredicate<'v>) {
364 walk_where_predicate(self, predicate)
366 fn visit_fn_decl(&mut self, fd: &'v FnDecl<'v>) {
367 walk_fn_decl(self, fd)
369 fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl<'v>, b: BodyId, s: Span, id: HirId) {
370 walk_fn(self, fk, fd, b, s, id)
372 fn visit_use(&mut self, path: &'v Path<'v>, hir_id: HirId) {
373 walk_use(self, path, hir_id)
375 fn visit_trait_item(&mut self, ti: &'v TraitItem<'v>) {
376 walk_trait_item(self, ti)
378 fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) {
379 walk_trait_item_ref(self, ii)
381 fn visit_impl_item(&mut self, ii: &'v ImplItem<'v>) {
382 walk_impl_item(self, ii)
384 fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef<'v>) {
385 walk_impl_item_ref(self, ii)
387 fn visit_trait_ref(&mut self, t: &'v TraitRef<'v>) {
388 walk_trait_ref(self, t)
390 fn visit_param_bound(&mut self, bounds: &'v GenericBound<'v>) {
391 walk_param_bound(self, bounds)
393 fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef<'v>, m: TraitBoundModifier) {
394 walk_poly_trait_ref(self, t, m)
396 fn visit_variant_data(
398 s: &'v VariantData<'v>,
404 walk_struct_def(self, s)
406 fn visit_struct_field(&mut self, s: &'v StructField<'v>) {
407 walk_struct_field(self, s)
411 enum_definition: &'v EnumDef<'v>,
412 generics: &'v Generics<'v>,
416 walk_enum_def(self, enum_definition, generics, item_id)
418 fn visit_variant(&mut self, v: &'v Variant<'v>, g: &'v Generics<'v>, item_id: HirId) {
419 walk_variant(self, v, g, item_id)
421 fn visit_label(&mut self, label: &'v Label) {
422 walk_label(self, label)
424 fn visit_generic_arg(&mut self, generic_arg: &'v GenericArg<'v>) {
426 GenericArg::Lifetime(lt) => self.visit_lifetime(lt),
427 GenericArg::Type(ty) => self.visit_ty(ty),
428 GenericArg::Const(ct) => self.visit_anon_const(&ct.value),
431 fn visit_lifetime(&mut self, lifetime: &'v Lifetime) {
432 walk_lifetime(self, lifetime)
434 fn visit_qpath(&mut self, qpath: &'v QPath<'v>, id: HirId, span: Span) {
435 walk_qpath(self, qpath, id, span)
437 fn visit_path(&mut self, path: &'v Path<'v>, _id: HirId) {
438 walk_path(self, path)
440 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment<'v>) {
441 walk_path_segment(self, path_span, path_segment)
443 fn visit_generic_args(&mut self, path_span: Span, generic_args: &'v GenericArgs<'v>) {
444 walk_generic_args(self, path_span, generic_args)
446 fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding<'v>) {
447 walk_assoc_type_binding(self, type_binding)
449 fn visit_attribute(&mut self, _attr: &'v Attribute) {}
450 fn visit_macro_def(&mut self, macro_def: &'v MacroDef<'v>) {
451 walk_macro_def(self, macro_def)
453 fn visit_vis(&mut self, vis: &'v Visibility<'v>) {
456 fn visit_associated_item_kind(&mut self, kind: &'v AssocItemKind) {
457 walk_associated_item_kind(self, kind);
459 fn visit_defaultness(&mut self, defaultness: &'v Defaultness) {
460 walk_defaultness(self, defaultness);
464 /// Walks the contents of a crate. See also `Crate::visit_all_items`.
465 pub fn walk_crate<'v, V: Visitor<'v>>(visitor: &mut V, krate: &'v Crate<'v>) {
466 visitor.visit_mod(&krate.item.module, krate.item.span, CRATE_HIR_ID);
467 walk_list!(visitor, visit_attribute, krate.item.attrs);
468 walk_list!(visitor, visit_macro_def, krate.exported_macros);
471 pub fn walk_macro_def<'v, V: Visitor<'v>>(visitor: &mut V, macro_def: &'v MacroDef<'v>) {
472 visitor.visit_id(macro_def.hir_id);
473 visitor.visit_ident(macro_def.ident);
474 walk_list!(visitor, visit_attribute, macro_def.attrs);
477 pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod<'v>, mod_hir_id: HirId) {
478 visitor.visit_id(mod_hir_id);
479 for &item_id in module.item_ids {
480 visitor.visit_nested_item(item_id);
484 pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body<'v>) {
485 walk_list!(visitor, visit_param, body.params);
486 visitor.visit_expr(&body.value);
489 pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local<'v>) {
490 // Intentionally visiting the expr first - the initialization expr
491 // dominates the local's definition.
492 walk_list!(visitor, visit_expr, &local.init);
493 walk_list!(visitor, visit_attribute, local.attrs.iter());
494 visitor.visit_id(local.hir_id);
495 visitor.visit_pat(&local.pat);
496 walk_list!(visitor, visit_ty, &local.ty);
499 pub fn walk_ident<'v, V: Visitor<'v>>(visitor: &mut V, ident: Ident) {
500 visitor.visit_name(ident.span, ident.name);
503 pub fn walk_label<'v, V: Visitor<'v>>(visitor: &mut V, label: &'v Label) {
504 visitor.visit_ident(label.ident);
507 pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) {
508 visitor.visit_id(lifetime.hir_id);
509 match lifetime.name {
510 LifetimeName::Param(ParamName::Plain(ident)) => {
511 visitor.visit_ident(ident);
513 LifetimeName::Param(ParamName::Fresh(_))
514 | LifetimeName::Param(ParamName::Error)
515 | LifetimeName::Static
516 | LifetimeName::Error
517 | LifetimeName::Implicit
518 | LifetimeName::ImplicitObjectLifetimeDefault
519 | LifetimeName::Underscore => {}
523 pub fn walk_poly_trait_ref<'v, V: Visitor<'v>>(
525 trait_ref: &'v PolyTraitRef<'v>,
526 _modifier: TraitBoundModifier,
528 walk_list!(visitor, visit_generic_param, trait_ref.bound_generic_params);
529 visitor.visit_trait_ref(&trait_ref.trait_ref);
532 pub fn walk_trait_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_ref: &'v TraitRef<'v>) {
533 visitor.visit_id(trait_ref.hir_ref_id);
534 visitor.visit_path(&trait_ref.path, trait_ref.hir_ref_id)
537 pub fn walk_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v Param<'v>) {
538 visitor.visit_id(param.hir_id);
539 visitor.visit_pat(¶m.pat);
540 walk_list!(visitor, visit_attribute, param.attrs);
543 pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) {
544 visitor.visit_vis(&item.vis);
545 visitor.visit_ident(item.ident);
547 ItemKind::ExternCrate(orig_name) => {
548 visitor.visit_id(item.hir_id);
549 if let Some(orig_name) = orig_name {
550 visitor.visit_name(item.span, orig_name);
553 ItemKind::Use(ref path, _) => {
554 visitor.visit_use(path, item.hir_id);
556 ItemKind::Static(ref typ, _, body) | ItemKind::Const(ref typ, body) => {
557 visitor.visit_id(item.hir_id);
558 visitor.visit_ty(typ);
559 visitor.visit_nested_body(body);
561 ItemKind::Fn(ref sig, ref generics, body_id) => visitor.visit_fn(
562 FnKind::ItemFn(item.ident, generics, sig.header, &item.vis, &item.attrs),
568 ItemKind::Mod(ref module) => {
569 // `visit_mod()` takes care of visiting the `Item`'s `HirId`.
570 visitor.visit_mod(module, item.span, item.hir_id)
572 ItemKind::ForeignMod(ref foreign_module) => {
573 visitor.visit_id(item.hir_id);
574 walk_list!(visitor, visit_foreign_item, foreign_module.items);
576 ItemKind::GlobalAsm(_) => {
577 visitor.visit_id(item.hir_id);
579 ItemKind::TyAlias(ref ty, ref generics) => {
580 visitor.visit_id(item.hir_id);
581 visitor.visit_ty(ty);
582 visitor.visit_generics(generics)
584 ItemKind::OpaqueTy(OpaqueTy { ref generics, bounds, .. }) => {
585 visitor.visit_id(item.hir_id);
586 walk_generics(visitor, generics);
587 walk_list!(visitor, visit_param_bound, bounds);
589 ItemKind::Enum(ref enum_definition, ref generics) => {
590 visitor.visit_generics(generics);
591 // `visit_enum_def()` takes care of visiting the `Item`'s `HirId`.
592 visitor.visit_enum_def(enum_definition, generics, item.hir_id, item.span)
605 visitor.visit_id(item.hir_id);
606 visitor.visit_generics(generics);
607 walk_list!(visitor, visit_trait_ref, of_trait);
608 visitor.visit_ty(self_ty);
609 walk_list!(visitor, visit_impl_item_ref, items);
611 ItemKind::Struct(ref struct_definition, ref generics)
612 | ItemKind::Union(ref struct_definition, ref generics) => {
613 visitor.visit_generics(generics);
614 visitor.visit_id(item.hir_id);
615 visitor.visit_variant_data(
623 ItemKind::Trait(.., ref generics, bounds, trait_item_refs) => {
624 visitor.visit_id(item.hir_id);
625 visitor.visit_generics(generics);
626 walk_list!(visitor, visit_param_bound, bounds);
627 walk_list!(visitor, visit_trait_item_ref, trait_item_refs);
629 ItemKind::TraitAlias(ref generics, bounds) => {
630 visitor.visit_id(item.hir_id);
631 visitor.visit_generics(generics);
632 walk_list!(visitor, visit_param_bound, bounds);
635 walk_list!(visitor, visit_attribute, item.attrs);
638 pub fn walk_use<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>, hir_id: HirId) {
639 visitor.visit_id(hir_id);
640 visitor.visit_path(path, hir_id);
643 pub fn walk_enum_def<'v, V: Visitor<'v>>(
645 enum_definition: &'v EnumDef<'v>,
646 generics: &'v Generics<'v>,
649 visitor.visit_id(item_id);
650 walk_list!(visitor, visit_variant, enum_definition.variants, generics, item_id);
653 pub fn walk_variant<'v, V: Visitor<'v>>(
655 variant: &'v Variant<'v>,
656 generics: &'v Generics<'v>,
657 parent_item_id: HirId,
659 visitor.visit_ident(variant.ident);
660 visitor.visit_id(variant.id);
661 visitor.visit_variant_data(
668 walk_list!(visitor, visit_anon_const, &variant.disr_expr);
669 walk_list!(visitor, visit_attribute, variant.attrs);
672 pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty<'v>) {
673 visitor.visit_id(typ.hir_id);
676 TyKind::Slice(ref ty) => visitor.visit_ty(ty),
677 TyKind::Ptr(ref mutable_type) => visitor.visit_ty(&mutable_type.ty),
678 TyKind::Rptr(ref lifetime, ref mutable_type) => {
679 visitor.visit_lifetime(lifetime);
680 visitor.visit_ty(&mutable_type.ty)
683 TyKind::Tup(tuple_element_types) => {
684 walk_list!(visitor, visit_ty, tuple_element_types);
686 TyKind::BareFn(ref function_declaration) => {
687 walk_list!(visitor, visit_generic_param, function_declaration.generic_params);
688 visitor.visit_fn_decl(&function_declaration.decl);
690 TyKind::Path(ref qpath) => {
691 visitor.visit_qpath(qpath, typ.hir_id, typ.span);
693 TyKind::OpaqueDef(item_id, lifetimes) => {
694 visitor.visit_nested_item(item_id);
695 walk_list!(visitor, visit_generic_arg, lifetimes);
697 TyKind::Array(ref ty, ref length) => {
698 visitor.visit_ty(ty);
699 visitor.visit_anon_const(length)
701 TyKind::TraitObject(bounds, ref lifetime) => {
702 for bound in bounds {
703 visitor.visit_poly_trait_ref(bound, TraitBoundModifier::None);
705 visitor.visit_lifetime(lifetime);
707 TyKind::Typeof(ref expression) => visitor.visit_anon_const(expression),
708 TyKind::Infer | TyKind::Err => {}
712 pub fn walk_qpath<'v, V: Visitor<'v>>(
714 qpath: &'v QPath<'v>,
719 QPath::Resolved(ref maybe_qself, ref path) => {
720 walk_list!(visitor, visit_ty, maybe_qself);
721 visitor.visit_path(path, id)
723 QPath::TypeRelative(ref qself, ref segment) => {
724 visitor.visit_ty(qself);
725 visitor.visit_path_segment(span, segment);
727 QPath::LangItem(..) => {}
731 pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>) {
732 for segment in path.segments {
733 visitor.visit_path_segment(path.span, segment);
737 pub fn walk_path_segment<'v, V: Visitor<'v>>(
740 segment: &'v PathSegment<'v>,
742 visitor.visit_ident(segment.ident);
743 walk_list!(visitor, visit_id, segment.hir_id);
744 if let Some(ref args) = segment.args {
745 visitor.visit_generic_args(path_span, args);
749 pub fn walk_generic_args<'v, V: Visitor<'v>>(
752 generic_args: &'v GenericArgs<'v>,
754 walk_list!(visitor, visit_generic_arg, generic_args.args);
755 walk_list!(visitor, visit_assoc_type_binding, generic_args.bindings);
758 pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(
760 type_binding: &'v TypeBinding<'v>,
762 visitor.visit_id(type_binding.hir_id);
763 visitor.visit_ident(type_binding.ident);
764 match type_binding.kind {
765 TypeBindingKind::Equality { ref ty } => {
766 visitor.visit_ty(ty);
768 TypeBindingKind::Constraint { bounds } => {
769 walk_list!(visitor, visit_param_bound, bounds);
774 pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat<'v>) {
775 visitor.visit_id(pattern.hir_id);
777 PatKind::TupleStruct(ref qpath, children, _) => {
778 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
779 walk_list!(visitor, visit_pat, children);
781 PatKind::Path(ref qpath) => {
782 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
784 PatKind::Struct(ref qpath, fields, _) => {
785 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
786 for field in fields {
787 visitor.visit_id(field.hir_id);
788 visitor.visit_ident(field.ident);
789 visitor.visit_pat(&field.pat)
792 PatKind::Or(pats) => walk_list!(visitor, visit_pat, pats),
793 PatKind::Tuple(tuple_elements, _) => {
794 walk_list!(visitor, visit_pat, tuple_elements);
796 PatKind::Box(ref subpattern) | PatKind::Ref(ref subpattern, _) => {
797 visitor.visit_pat(subpattern)
799 PatKind::Binding(_, _hir_id, ident, ref optional_subpattern) => {
800 visitor.visit_ident(ident);
801 walk_list!(visitor, visit_pat, optional_subpattern);
803 PatKind::Lit(ref expression) => visitor.visit_expr(expression),
804 PatKind::Range(ref lower_bound, ref upper_bound, _) => {
805 walk_list!(visitor, visit_expr, lower_bound);
806 walk_list!(visitor, visit_expr, upper_bound);
809 PatKind::Slice(prepatterns, ref slice_pattern, postpatterns) => {
810 walk_list!(visitor, visit_pat, prepatterns);
811 walk_list!(visitor, visit_pat, slice_pattern);
812 walk_list!(visitor, visit_pat, postpatterns);
817 pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V, foreign_item: &'v ForeignItem<'v>) {
818 visitor.visit_id(foreign_item.hir_id);
819 visitor.visit_vis(&foreign_item.vis);
820 visitor.visit_ident(foreign_item.ident);
822 match foreign_item.kind {
823 ForeignItemKind::Fn(ref function_declaration, param_names, ref generics) => {
824 visitor.visit_generics(generics);
825 visitor.visit_fn_decl(function_declaration);
826 for ¶m_name in param_names {
827 visitor.visit_ident(param_name);
830 ForeignItemKind::Static(ref typ, _) => visitor.visit_ty(typ),
831 ForeignItemKind::Type => (),
834 walk_list!(visitor, visit_attribute, foreign_item.attrs);
837 pub fn walk_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v GenericBound<'v>) {
839 GenericBound::Trait(ref typ, modifier) => {
840 visitor.visit_poly_trait_ref(typ, modifier);
842 GenericBound::LangItemTrait(_, span, hir_id, args) => {
843 visitor.visit_id(hir_id);
844 visitor.visit_generic_args(span, args);
846 GenericBound::Outlives(ref lifetime) => visitor.visit_lifetime(lifetime),
850 pub fn walk_generic_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v GenericParam<'v>) {
851 visitor.visit_id(param.hir_id);
852 walk_list!(visitor, visit_attribute, param.attrs);
854 ParamName::Plain(ident) => visitor.visit_ident(ident),
855 ParamName::Error | ParamName::Fresh(_) => {}
858 GenericParamKind::Lifetime { .. } => {}
859 GenericParamKind::Type { ref default, .. } => walk_list!(visitor, visit_ty, default),
860 GenericParamKind::Const { ref ty } => visitor.visit_ty(ty),
862 walk_list!(visitor, visit_param_bound, param.bounds);
865 pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics<'v>) {
866 walk_list!(visitor, visit_generic_param, generics.params);
867 walk_list!(visitor, visit_where_predicate, generics.where_clause.predicates);
870 pub fn walk_where_predicate<'v, V: Visitor<'v>>(
872 predicate: &'v WherePredicate<'v>,
875 &WherePredicate::BoundPredicate(WhereBoundPredicate {
878 bound_generic_params,
881 visitor.visit_ty(bounded_ty);
882 walk_list!(visitor, visit_param_bound, bounds);
883 walk_list!(visitor, visit_generic_param, bound_generic_params);
885 &WherePredicate::RegionPredicate(WhereRegionPredicate { ref lifetime, bounds, .. }) => {
886 visitor.visit_lifetime(lifetime);
887 walk_list!(visitor, visit_param_bound, bounds);
889 &WherePredicate::EqPredicate(WhereEqPredicate {
890 hir_id, ref lhs_ty, ref rhs_ty, ..
892 visitor.visit_id(hir_id);
893 visitor.visit_ty(lhs_ty);
894 visitor.visit_ty(rhs_ty);
899 pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FnRetTy<'v>) {
900 if let FnRetTy::Return(ref output_ty) = *ret_ty {
901 visitor.visit_ty(output_ty)
905 pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl<'v>) {
906 for ty in function_declaration.inputs {
909 walk_fn_ret_ty(visitor, &function_declaration.output)
912 pub fn walk_fn_kind<'v, V: Visitor<'v>>(visitor: &mut V, function_kind: FnKind<'v>) {
913 match function_kind {
914 FnKind::ItemFn(_, generics, ..) => {
915 visitor.visit_generics(generics);
917 FnKind::Method(..) | FnKind::Closure(_) => {}
921 pub fn walk_fn<'v, V: Visitor<'v>>(
923 function_kind: FnKind<'v>,
924 function_declaration: &'v FnDecl<'v>,
929 visitor.visit_id(id);
930 visitor.visit_fn_decl(function_declaration);
931 walk_fn_kind(visitor, function_kind);
932 visitor.visit_nested_body(body_id)
935 pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem<'v>) {
936 visitor.visit_ident(trait_item.ident);
937 walk_list!(visitor, visit_attribute, trait_item.attrs);
938 visitor.visit_generics(&trait_item.generics);
939 match trait_item.kind {
940 TraitItemKind::Const(ref ty, default) => {
941 visitor.visit_id(trait_item.hir_id);
942 visitor.visit_ty(ty);
943 walk_list!(visitor, visit_nested_body, default);
945 TraitItemKind::Fn(ref sig, TraitFn::Required(param_names)) => {
946 visitor.visit_id(trait_item.hir_id);
947 visitor.visit_fn_decl(&sig.decl);
948 for ¶m_name in param_names {
949 visitor.visit_ident(param_name);
952 TraitItemKind::Fn(ref sig, TraitFn::Provided(body_id)) => {
954 FnKind::Method(trait_item.ident, sig, None, &trait_item.attrs),
961 TraitItemKind::Type(bounds, ref default) => {
962 visitor.visit_id(trait_item.hir_id);
963 walk_list!(visitor, visit_param_bound, bounds);
964 walk_list!(visitor, visit_ty, default);
969 pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref: &'v TraitItemRef) {
970 // N.B., deliberately force a compilation error if/when new fields are added.
971 let TraitItemRef { id, ident, ref kind, span: _, ref defaultness } = *trait_item_ref;
972 visitor.visit_nested_trait_item(id);
973 visitor.visit_ident(ident);
974 visitor.visit_associated_item_kind(kind);
975 visitor.visit_defaultness(defaultness);
978 pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem<'v>) {
979 // N.B., deliberately force a compilation error if/when new fields are added.
991 visitor.visit_ident(ident);
992 visitor.visit_vis(vis);
993 visitor.visit_defaultness(defaultness);
994 walk_list!(visitor, visit_attribute, attrs);
995 visitor.visit_generics(generics);
997 ImplItemKind::Const(ref ty, body) => {
998 visitor.visit_id(impl_item.hir_id);
999 visitor.visit_ty(ty);
1000 visitor.visit_nested_body(body);
1002 ImplItemKind::Fn(ref sig, body_id) => {
1004 FnKind::Method(impl_item.ident, sig, Some(&impl_item.vis), &impl_item.attrs),
1011 ImplItemKind::TyAlias(ref ty) => {
1012 visitor.visit_id(impl_item.hir_id);
1013 visitor.visit_ty(ty);
1018 pub fn walk_impl_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, impl_item_ref: &'v ImplItemRef<'v>) {
1019 // N.B., deliberately force a compilation error if/when new fields are added.
1020 let ImplItemRef { id, ident, ref kind, span: _, ref vis, ref defaultness } = *impl_item_ref;
1021 visitor.visit_nested_impl_item(id);
1022 visitor.visit_ident(ident);
1023 visitor.visit_associated_item_kind(kind);
1024 visitor.visit_vis(vis);
1025 visitor.visit_defaultness(defaultness);
1028 pub fn walk_struct_def<'v, V: Visitor<'v>>(
1030 struct_definition: &'v VariantData<'v>,
1032 walk_list!(visitor, visit_id, struct_definition.ctor_hir_id());
1033 walk_list!(visitor, visit_struct_field, struct_definition.fields());
1036 pub fn walk_struct_field<'v, V: Visitor<'v>>(visitor: &mut V, struct_field: &'v StructField<'v>) {
1037 visitor.visit_id(struct_field.hir_id);
1038 visitor.visit_vis(&struct_field.vis);
1039 visitor.visit_ident(struct_field.ident);
1040 visitor.visit_ty(&struct_field.ty);
1041 walk_list!(visitor, visit_attribute, struct_field.attrs);
1044 pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block<'v>) {
1045 visitor.visit_id(block.hir_id);
1046 walk_list!(visitor, visit_stmt, block.stmts);
1047 walk_list!(visitor, visit_expr, &block.expr);
1050 pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt<'v>) {
1051 visitor.visit_id(statement.hir_id);
1052 match statement.kind {
1053 StmtKind::Local(ref local) => visitor.visit_local(local),
1054 StmtKind::Item(item) => visitor.visit_nested_item(item),
1055 StmtKind::Expr(ref expression) | StmtKind::Semi(ref expression) => {
1056 visitor.visit_expr(expression)
1061 pub fn walk_anon_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v AnonConst) {
1062 visitor.visit_id(constant.hir_id);
1063 visitor.visit_nested_body(constant.body);
1066 pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>) {
1067 visitor.visit_id(expression.hir_id);
1068 walk_list!(visitor, visit_attribute, expression.attrs.iter());
1069 match expression.kind {
1070 ExprKind::Box(ref subexpression) => visitor.visit_expr(subexpression),
1071 ExprKind::Array(subexpressions) => {
1072 walk_list!(visitor, visit_expr, subexpressions);
1074 ExprKind::Repeat(ref element, ref count) => {
1075 visitor.visit_expr(element);
1076 visitor.visit_anon_const(count)
1078 ExprKind::Struct(ref qpath, fields, ref optional_base) => {
1079 visitor.visit_qpath(qpath, expression.hir_id, expression.span);
1080 for field in fields {
1081 visitor.visit_id(field.hir_id);
1082 visitor.visit_ident(field.ident);
1083 visitor.visit_expr(&field.expr)
1085 walk_list!(visitor, visit_expr, optional_base);
1087 ExprKind::Tup(subexpressions) => {
1088 walk_list!(visitor, visit_expr, subexpressions);
1090 ExprKind::Call(ref callee_expression, arguments) => {
1091 visitor.visit_expr(callee_expression);
1092 walk_list!(visitor, visit_expr, arguments);
1094 ExprKind::MethodCall(ref segment, _, arguments, _) => {
1095 visitor.visit_path_segment(expression.span, segment);
1096 walk_list!(visitor, visit_expr, arguments);
1098 ExprKind::Binary(_, ref left_expression, ref right_expression) => {
1099 visitor.visit_expr(left_expression);
1100 visitor.visit_expr(right_expression)
1102 ExprKind::AddrOf(_, _, ref subexpression) | ExprKind::Unary(_, ref subexpression) => {
1103 visitor.visit_expr(subexpression)
1105 ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => {
1106 visitor.visit_expr(subexpression);
1107 visitor.visit_ty(typ)
1109 ExprKind::DropTemps(ref subexpression) => {
1110 visitor.visit_expr(subexpression);
1112 ExprKind::Loop(ref block, ref opt_label, _) => {
1113 walk_list!(visitor, visit_label, opt_label);
1114 visitor.visit_block(block);
1116 ExprKind::Match(ref subexpression, arms, _) => {
1117 visitor.visit_expr(subexpression);
1118 walk_list!(visitor, visit_arm, arms);
1120 ExprKind::Closure(_, ref function_declaration, body, _fn_decl_span, _gen) => visitor
1122 FnKind::Closure(&expression.attrs),
1123 function_declaration,
1128 ExprKind::Block(ref block, ref opt_label) => {
1129 walk_list!(visitor, visit_label, opt_label);
1130 visitor.visit_block(block);
1132 ExprKind::Assign(ref lhs, ref rhs, _) => {
1133 visitor.visit_expr(rhs);
1134 visitor.visit_expr(lhs)
1136 ExprKind::AssignOp(_, ref left_expression, ref right_expression) => {
1137 visitor.visit_expr(right_expression);
1138 visitor.visit_expr(left_expression);
1140 ExprKind::Field(ref subexpression, ident) => {
1141 visitor.visit_expr(subexpression);
1142 visitor.visit_ident(ident);
1144 ExprKind::Index(ref main_expression, ref index_expression) => {
1145 visitor.visit_expr(main_expression);
1146 visitor.visit_expr(index_expression)
1148 ExprKind::Path(ref qpath) => {
1149 visitor.visit_qpath(qpath, expression.hir_id, expression.span);
1151 ExprKind::Break(ref destination, ref opt_expr) => {
1152 walk_list!(visitor, visit_label, &destination.label);
1153 walk_list!(visitor, visit_expr, opt_expr);
1155 ExprKind::Continue(ref destination) => {
1156 walk_list!(visitor, visit_label, &destination.label);
1158 ExprKind::Ret(ref optional_expression) => {
1159 walk_list!(visitor, visit_expr, optional_expression);
1161 ExprKind::InlineAsm(ref asm) => {
1162 for op in asm.operands {
1164 InlineAsmOperand::In { expr, .. }
1165 | InlineAsmOperand::InOut { expr, .. }
1166 | InlineAsmOperand::Const { expr, .. }
1167 | InlineAsmOperand::Sym { expr, .. } => visitor.visit_expr(expr),
1168 InlineAsmOperand::Out { expr, .. } => {
1169 if let Some(expr) = expr {
1170 visitor.visit_expr(expr);
1173 InlineAsmOperand::SplitInOut { in_expr, out_expr, .. } => {
1174 visitor.visit_expr(in_expr);
1175 if let Some(out_expr) = out_expr {
1176 visitor.visit_expr(out_expr);
1182 ExprKind::LlvmInlineAsm(ref asm) => {
1183 walk_list!(visitor, visit_expr, asm.outputs_exprs);
1184 walk_list!(visitor, visit_expr, asm.inputs_exprs);
1186 ExprKind::Yield(ref subexpression, _) => {
1187 visitor.visit_expr(subexpression);
1189 ExprKind::Lit(_) | ExprKind::Err => {}
1193 pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm<'v>) {
1194 visitor.visit_id(arm.hir_id);
1195 visitor.visit_pat(&arm.pat);
1196 if let Some(ref g) = arm.guard {
1198 Guard::If(ref e) => visitor.visit_expr(e),
1201 visitor.visit_expr(&arm.body);
1202 walk_list!(visitor, visit_attribute, arm.attrs);
1205 pub fn walk_vis<'v, V: Visitor<'v>>(visitor: &mut V, vis: &'v Visibility<'v>) {
1206 if let VisibilityKind::Restricted { ref path, hir_id } = vis.node {
1207 visitor.visit_id(hir_id);
1208 visitor.visit_path(path, hir_id)
1212 pub fn walk_associated_item_kind<'v, V: Visitor<'v>>(_: &mut V, _: &'v AssocItemKind) {
1213 // No visitable content here: this fn exists so you can call it if
1214 // the right thing to do, should content be added in the future,
1215 // would be to walk it.
1218 pub fn walk_defaultness<'v, V: Visitor<'v>>(_: &mut V, _: &'v Defaultness) {
1219 // No visitable content here: this fn exists so you can call it if
1220 // the right thing to do, should content be added in the future,
1221 // would be to walk it.