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);
68 fn visit_foreign_item(&mut self, foreign_item: &'hir ForeignItem<'hir>) {
69 self.visitor.visit_foreign_item(foreign_item);
73 pub trait IntoVisitor<'hir> {
74 type Visitor: Visitor<'hir>;
75 fn into_visitor(&self) -> Self::Visitor;
78 pub struct ParDeepVisitor<V>(pub V);
80 impl<'hir, V> ParItemLikeVisitor<'hir> for ParDeepVisitor<V>
84 fn visit_item(&self, item: &'hir Item<'hir>) {
85 self.0.into_visitor().visit_item(item);
88 fn visit_trait_item(&self, trait_item: &'hir TraitItem<'hir>) {
89 self.0.into_visitor().visit_trait_item(trait_item);
92 fn visit_impl_item(&self, impl_item: &'hir ImplItem<'hir>) {
93 self.0.into_visitor().visit_impl_item(impl_item);
96 fn visit_foreign_item(&self, foreign_item: &'hir ForeignItem<'hir>) {
97 self.0.into_visitor().visit_foreign_item(foreign_item);
101 #[derive(Copy, Clone)]
102 pub enum FnKind<'a> {
103 /// `#[xxx] pub async/const/extern "Abi" fn foo()`
104 ItemFn(Ident, &'a Generics<'a>, FnHeader, &'a Visibility<'a>, &'a [Attribute]),
107 Method(Ident, &'a FnSig<'a>, Option<&'a Visibility<'a>>, &'a [Attribute]),
110 Closure(&'a [Attribute]),
113 impl<'a> FnKind<'a> {
114 pub fn attrs(&self) -> &'a [Attribute] {
116 FnKind::ItemFn(.., attrs) => attrs,
117 FnKind::Method(.., attrs) => attrs,
118 FnKind::Closure(attrs) => attrs,
122 pub fn header(&self) -> Option<&FnHeader> {
124 FnKind::ItemFn(_, _, ref header, _, _) => Some(header),
125 FnKind::Method(_, ref sig, _, _) => Some(&sig.header),
126 FnKind::Closure(_) => None,
131 /// An abstract representation of the HIR `rustc_middle::hir::map::Map`.
132 pub trait Map<'hir> {
133 /// Retrieves the `Node` corresponding to `id`, returning `None` if cannot be found.
134 fn find(&self, hir_id: HirId) -> Option<Node<'hir>>;
135 fn body(&self, id: BodyId) -> &'hir Body<'hir>;
136 fn item(&self, id: ItemId) -> &'hir Item<'hir>;
137 fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir>;
138 fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem<'hir>;
139 fn foreign_item(&self, id: ForeignItemId) -> &'hir ForeignItem<'hir>;
142 /// An erased version of `Map<'hir>`, using dynamic dispatch.
143 /// NOTE: This type is effectively only usable with `NestedVisitorMap::None`.
144 pub struct ErasedMap<'hir>(&'hir dyn Map<'hir>);
146 impl<'hir> Map<'hir> for ErasedMap<'hir> {
147 fn find(&self, _: HirId) -> Option<Node<'hir>> {
150 fn body(&self, id: BodyId) -> &'hir Body<'hir> {
153 fn item(&self, id: ItemId) -> &'hir Item<'hir> {
156 fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir> {
157 self.0.trait_item(id)
159 fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem<'hir> {
162 fn foreign_item(&self, id: ForeignItemId) -> &'hir ForeignItem<'hir> {
163 self.0.foreign_item(id)
167 /// Specifies what nested things a visitor wants to visit. The most
168 /// common choice is `OnlyBodies`, which will cause the visitor to
169 /// visit fn bodies for fns that it encounters, but skip over nested
170 /// item-like things.
172 /// See the comments on `ItemLikeVisitor` for more details on the overall
174 pub enum NestedVisitorMap<M> {
175 /// Do not visit any nested things. When you add a new
176 /// "non-nested" thing, you will want to audit such uses to see if
177 /// they remain valid.
179 /// Use this if you are only walking some particular kind of tree
180 /// (i.e., a type, or fn signature) and you don't want to thread a
184 /// Do not visit nested item-like things, but visit nested things
185 /// that are inside of an item-like.
187 /// **This is the most common choice.** A very common pattern is
188 /// to use `visit_all_item_likes()` as an outer loop,
189 /// and to have the visitor that visits the contents of each item
190 /// using this setting.
193 /// Visits all nested things, including item-likes.
195 /// **This is an unusual choice.** It is used when you want to
196 /// process everything within their lexical context. Typically you
197 /// kick off the visit by doing `walk_krate()`.
201 impl<M> NestedVisitorMap<M> {
202 /// Returns the map to use for an "intra item-like" thing (if any).
203 /// E.g., function body.
204 fn intra(self) -> Option<M> {
206 NestedVisitorMap::None => None,
207 NestedVisitorMap::OnlyBodies(map) => Some(map),
208 NestedVisitorMap::All(map) => Some(map),
212 /// Returns the map to use for an "item-like" thing (if any).
213 /// E.g., item, impl-item.
214 fn inter(self) -> Option<M> {
216 NestedVisitorMap::None => None,
217 NestedVisitorMap::OnlyBodies(_) => None,
218 NestedVisitorMap::All(map) => Some(map),
223 /// Each method of the Visitor trait is a hook to be potentially
224 /// overridden. Each method's default implementation recursively visits
225 /// the substructure of the input via the corresponding `walk` method;
226 /// e.g., the `visit_mod` method by default calls `intravisit::walk_mod`.
228 /// Note that this visitor does NOT visit nested items by default
229 /// (this is why the module is called `intravisit`, to distinguish it
230 /// from the AST's `visit` module, which acts differently). If you
231 /// simply want to visit all items in the crate in some order, you
232 /// should call `Crate::visit_all_items`. Otherwise, see the comment
233 /// on `visit_nested_item` for details on how to visit nested items.
235 /// If you want to ensure that your code handles every variant
236 /// explicitly, you need to override each method. (And you also need
237 /// to monitor future changes to `Visitor` in case a new method with a
238 /// new default implementation gets introduced.)
239 pub trait Visitor<'v>: Sized {
242 ///////////////////////////////////////////////////////////////////////////
245 /// The default versions of the `visit_nested_XXX` routines invoke
246 /// this method to get a map to use. By selecting an enum variant,
247 /// you control which kinds of nested HIR are visited; see
248 /// `NestedVisitorMap` for details. By "nested HIR", we are
249 /// referring to bits of HIR that are not directly embedded within
250 /// one another but rather indirectly, through a table in the
251 /// crate. This is done to control dependencies during incremental
252 /// compilation: the non-inline bits of HIR can be tracked and
253 /// hashed separately.
255 /// **If for some reason you want the nested behavior, but don't
256 /// have a `Map` at your disposal:** then you should override the
257 /// `visit_nested_XXX` methods, and override this method to
258 /// `panic!()`. This way, if a new `visit_nested_XXX` variant is
259 /// added in the future, we will see the panic in your code and
260 /// fix it appropriately.
261 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map>;
263 /// Invoked when a nested item is encountered. By default does
264 /// nothing unless you override `nested_visit_map` to return other than
265 /// `None`, in which case it will walk the item. **You probably
266 /// don't want to override this method** -- instead, override
267 /// `nested_visit_map` or use the "shallow" or "deep" visit
268 /// patterns described on `itemlikevisit::ItemLikeVisitor`. The only
269 /// reason to override this method is if you want a nested pattern
270 /// but cannot supply a `Map`; see `nested_visit_map` for advice.
271 fn visit_nested_item(&mut self, id: ItemId) {
272 let opt_item = self.nested_visit_map().inter().map(|map| map.item(id));
273 walk_list!(self, visit_item, opt_item);
276 /// Like `visit_nested_item()`, but for trait items. See
277 /// `visit_nested_item()` for advice on when to override this
279 fn visit_nested_trait_item(&mut self, id: TraitItemId) {
280 let opt_item = self.nested_visit_map().inter().map(|map| map.trait_item(id));
281 walk_list!(self, visit_trait_item, opt_item);
284 /// Like `visit_nested_item()`, but for impl items. See
285 /// `visit_nested_item()` for advice on when to override this
287 fn visit_nested_impl_item(&mut self, id: ImplItemId) {
288 let opt_item = self.nested_visit_map().inter().map(|map| map.impl_item(id));
289 walk_list!(self, visit_impl_item, opt_item);
292 /// Like `visit_nested_item()`, but for foreign items. See
293 /// `visit_nested_item()` for advice on when to override this
295 fn visit_nested_foreign_item(&mut self, id: ForeignItemId) {
296 let opt_item = self.nested_visit_map().inter().map(|map| map.foreign_item(id));
297 walk_list!(self, visit_foreign_item, opt_item);
300 /// Invoked to visit the body of a function, method or closure. Like
301 /// visit_nested_item, does nothing by default unless you override
302 /// `nested_visit_map` to return other than `None`, in which case it will walk
304 fn visit_nested_body(&mut self, id: BodyId) {
305 let opt_body = self.nested_visit_map().intra().map(|map| map.body(id));
306 walk_list!(self, visit_body, opt_body);
309 fn visit_param(&mut self, param: &'v Param<'v>) {
310 walk_param(self, param)
313 /// Visits the top-level item and (optionally) nested items / impl items. See
314 /// `visit_nested_item` for details.
315 fn visit_item(&mut self, i: &'v Item<'v>) {
319 fn visit_body(&mut self, b: &'v Body<'v>) {
323 /// When invoking `visit_all_item_likes()`, you need to supply an
324 /// item-like visitor. This method converts a "intra-visit"
325 /// visitor into an item-like visitor that walks the entire tree.
326 /// If you use this, you probably don't want to process the
327 /// contents of nested item-like things, since the outer loop will
328 /// visit them as well.
329 fn as_deep_visitor(&mut self) -> DeepVisitor<'_, Self> {
330 DeepVisitor::new(self)
333 ///////////////////////////////////////////////////////////////////////////
335 fn visit_id(&mut self, _hir_id: HirId) {
338 fn visit_name(&mut self, _span: Span, _name: Symbol) {
341 fn visit_ident(&mut self, ident: Ident) {
342 walk_ident(self, ident)
344 fn visit_mod(&mut self, m: &'v Mod<'v>, _s: Span, n: HirId) {
347 fn visit_foreign_item(&mut self, i: &'v ForeignItem<'v>) {
348 walk_foreign_item(self, i)
350 fn visit_local(&mut self, l: &'v Local<'v>) {
353 fn visit_block(&mut self, b: &'v Block<'v>) {
356 fn visit_stmt(&mut self, s: &'v Stmt<'v>) {
359 fn visit_arm(&mut self, a: &'v Arm<'v>) {
362 fn visit_pat(&mut self, p: &'v Pat<'v>) {
365 fn visit_anon_const(&mut self, c: &'v AnonConst) {
366 walk_anon_const(self, c)
368 fn visit_expr(&mut self, ex: &'v Expr<'v>) {
371 fn visit_ty(&mut self, t: &'v Ty<'v>) {
374 fn visit_generic_param(&mut self, p: &'v GenericParam<'v>) {
375 walk_generic_param(self, p)
377 fn visit_generics(&mut self, g: &'v Generics<'v>) {
378 walk_generics(self, g)
380 fn visit_where_predicate(&mut self, predicate: &'v WherePredicate<'v>) {
381 walk_where_predicate(self, predicate)
383 fn visit_fn_decl(&mut self, fd: &'v FnDecl<'v>) {
384 walk_fn_decl(self, fd)
386 fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl<'v>, b: BodyId, s: Span, id: HirId) {
387 walk_fn(self, fk, fd, b, s, id)
389 fn visit_use(&mut self, path: &'v Path<'v>, hir_id: HirId) {
390 walk_use(self, path, hir_id)
392 fn visit_trait_item(&mut self, ti: &'v TraitItem<'v>) {
393 walk_trait_item(self, ti)
395 fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) {
396 walk_trait_item_ref(self, ii)
398 fn visit_impl_item(&mut self, ii: &'v ImplItem<'v>) {
399 walk_impl_item(self, ii)
401 fn visit_foreign_item_ref(&mut self, ii: &'v ForeignItemRef<'v>) {
402 walk_foreign_item_ref(self, ii)
404 fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef<'v>) {
405 walk_impl_item_ref(self, ii)
407 fn visit_trait_ref(&mut self, t: &'v TraitRef<'v>) {
408 walk_trait_ref(self, t)
410 fn visit_param_bound(&mut self, bounds: &'v GenericBound<'v>) {
411 walk_param_bound(self, bounds)
413 fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef<'v>, m: TraitBoundModifier) {
414 walk_poly_trait_ref(self, t, m)
416 fn visit_variant_data(
418 s: &'v VariantData<'v>,
424 walk_struct_def(self, s)
426 fn visit_struct_field(&mut self, s: &'v StructField<'v>) {
427 walk_struct_field(self, s)
431 enum_definition: &'v EnumDef<'v>,
432 generics: &'v Generics<'v>,
436 walk_enum_def(self, enum_definition, generics, item_id)
438 fn visit_variant(&mut self, v: &'v Variant<'v>, g: &'v Generics<'v>, item_id: HirId) {
439 walk_variant(self, v, g, item_id)
441 fn visit_label(&mut self, label: &'v Label) {
442 walk_label(self, label)
444 fn visit_generic_arg(&mut self, generic_arg: &'v GenericArg<'v>) {
446 GenericArg::Lifetime(lt) => self.visit_lifetime(lt),
447 GenericArg::Type(ty) => self.visit_ty(ty),
448 GenericArg::Const(ct) => self.visit_anon_const(&ct.value),
451 fn visit_lifetime(&mut self, lifetime: &'v Lifetime) {
452 walk_lifetime(self, lifetime)
454 fn visit_qpath(&mut self, qpath: &'v QPath<'v>, id: HirId, span: Span) {
455 walk_qpath(self, qpath, id, span)
457 fn visit_path(&mut self, path: &'v Path<'v>, _id: HirId) {
458 walk_path(self, path)
460 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment<'v>) {
461 walk_path_segment(self, path_span, path_segment)
463 fn visit_generic_args(&mut self, path_span: Span, generic_args: &'v GenericArgs<'v>) {
464 walk_generic_args(self, path_span, generic_args)
466 fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding<'v>) {
467 walk_assoc_type_binding(self, type_binding)
469 fn visit_attribute(&mut self, _attr: &'v Attribute) {}
470 fn visit_macro_def(&mut self, macro_def: &'v MacroDef<'v>) {
471 walk_macro_def(self, macro_def)
473 fn visit_vis(&mut self, vis: &'v Visibility<'v>) {
476 fn visit_associated_item_kind(&mut self, kind: &'v AssocItemKind) {
477 walk_associated_item_kind(self, kind);
479 fn visit_defaultness(&mut self, defaultness: &'v Defaultness) {
480 walk_defaultness(self, defaultness);
484 /// Walks the contents of a crate. See also `Crate::visit_all_items`.
485 pub fn walk_crate<'v, V: Visitor<'v>>(visitor: &mut V, krate: &'v Crate<'v>) {
486 visitor.visit_mod(&krate.item.module, krate.item.span, CRATE_HIR_ID);
487 walk_list!(visitor, visit_attribute, krate.item.attrs);
488 walk_list!(visitor, visit_macro_def, krate.exported_macros);
491 pub fn walk_macro_def<'v, V: Visitor<'v>>(visitor: &mut V, macro_def: &'v MacroDef<'v>) {
492 visitor.visit_id(macro_def.hir_id);
493 visitor.visit_ident(macro_def.ident);
494 walk_list!(visitor, visit_attribute, macro_def.attrs);
497 pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod<'v>, mod_hir_id: HirId) {
498 visitor.visit_id(mod_hir_id);
499 for &item_id in module.item_ids {
500 visitor.visit_nested_item(item_id);
504 pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body<'v>) {
505 walk_list!(visitor, visit_param, body.params);
506 visitor.visit_expr(&body.value);
509 pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local<'v>) {
510 // Intentionally visiting the expr first - the initialization expr
511 // dominates the local's definition.
512 walk_list!(visitor, visit_expr, &local.init);
513 walk_list!(visitor, visit_attribute, local.attrs.iter());
514 visitor.visit_id(local.hir_id);
515 visitor.visit_pat(&local.pat);
516 walk_list!(visitor, visit_ty, &local.ty);
519 pub fn walk_ident<'v, V: Visitor<'v>>(visitor: &mut V, ident: Ident) {
520 visitor.visit_name(ident.span, ident.name);
523 pub fn walk_label<'v, V: Visitor<'v>>(visitor: &mut V, label: &'v Label) {
524 visitor.visit_ident(label.ident);
527 pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) {
528 visitor.visit_id(lifetime.hir_id);
529 match lifetime.name {
530 LifetimeName::Param(ParamName::Plain(ident)) => {
531 visitor.visit_ident(ident);
533 LifetimeName::Param(ParamName::Fresh(_))
534 | LifetimeName::Param(ParamName::Error)
535 | LifetimeName::Static
536 | LifetimeName::Error
537 | LifetimeName::Implicit
538 | LifetimeName::ImplicitObjectLifetimeDefault
539 | LifetimeName::Underscore => {}
543 pub fn walk_poly_trait_ref<'v, V: Visitor<'v>>(
545 trait_ref: &'v PolyTraitRef<'v>,
546 _modifier: TraitBoundModifier,
548 walk_list!(visitor, visit_generic_param, trait_ref.bound_generic_params);
549 visitor.visit_trait_ref(&trait_ref.trait_ref);
552 pub fn walk_trait_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_ref: &'v TraitRef<'v>) {
553 visitor.visit_id(trait_ref.hir_ref_id);
554 visitor.visit_path(&trait_ref.path, trait_ref.hir_ref_id)
557 pub fn walk_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v Param<'v>) {
558 visitor.visit_id(param.hir_id);
559 visitor.visit_pat(¶m.pat);
560 walk_list!(visitor, visit_attribute, param.attrs);
563 pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) {
564 visitor.visit_vis(&item.vis);
565 visitor.visit_ident(item.ident);
567 ItemKind::ExternCrate(orig_name) => {
568 visitor.visit_id(item.hir_id());
569 if let Some(orig_name) = orig_name {
570 visitor.visit_name(item.span, orig_name);
573 ItemKind::Use(ref path, _) => {
574 visitor.visit_use(path, item.hir_id());
576 ItemKind::Static(ref typ, _, body) | ItemKind::Const(ref typ, body) => {
577 visitor.visit_id(item.hir_id());
578 visitor.visit_ty(typ);
579 visitor.visit_nested_body(body);
581 ItemKind::Fn(ref sig, ref generics, body_id) => visitor.visit_fn(
582 FnKind::ItemFn(item.ident, generics, sig.header, &item.vis, &item.attrs),
588 ItemKind::Mod(ref module) => {
589 // `visit_mod()` takes care of visiting the `Item`'s `HirId`.
590 visitor.visit_mod(module, item.span, item.hir_id())
592 ItemKind::ForeignMod { abi: _, items } => {
593 visitor.visit_id(item.hir_id());
594 walk_list!(visitor, visit_foreign_item_ref, items);
596 ItemKind::GlobalAsm(_) => {
597 visitor.visit_id(item.hir_id());
599 ItemKind::TyAlias(ref ty, ref generics) => {
600 visitor.visit_id(item.hir_id());
601 visitor.visit_ty(ty);
602 visitor.visit_generics(generics)
604 ItemKind::OpaqueTy(OpaqueTy { ref generics, bounds, .. }) => {
605 visitor.visit_id(item.hir_id());
606 walk_generics(visitor, generics);
607 walk_list!(visitor, visit_param_bound, bounds);
609 ItemKind::Enum(ref enum_definition, ref generics) => {
610 visitor.visit_generics(generics);
611 // `visit_enum_def()` takes care of visiting the `Item`'s `HirId`.
612 visitor.visit_enum_def(enum_definition, generics, item.hir_id(), item.span)
614 ItemKind::Impl(Impl {
625 visitor.visit_id(item.hir_id());
626 visitor.visit_generics(generics);
627 walk_list!(visitor, visit_trait_ref, of_trait);
628 visitor.visit_ty(self_ty);
629 walk_list!(visitor, visit_impl_item_ref, items);
631 ItemKind::Struct(ref struct_definition, ref generics)
632 | ItemKind::Union(ref struct_definition, ref generics) => {
633 visitor.visit_generics(generics);
634 visitor.visit_id(item.hir_id());
635 visitor.visit_variant_data(
643 ItemKind::Trait(.., ref generics, bounds, trait_item_refs) => {
644 visitor.visit_id(item.hir_id());
645 visitor.visit_generics(generics);
646 walk_list!(visitor, visit_param_bound, bounds);
647 walk_list!(visitor, visit_trait_item_ref, trait_item_refs);
649 ItemKind::TraitAlias(ref generics, bounds) => {
650 visitor.visit_id(item.hir_id());
651 visitor.visit_generics(generics);
652 walk_list!(visitor, visit_param_bound, bounds);
655 walk_list!(visitor, visit_attribute, item.attrs);
658 pub fn walk_use<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>, hir_id: HirId) {
659 visitor.visit_id(hir_id);
660 visitor.visit_path(path, hir_id);
663 pub fn walk_enum_def<'v, V: Visitor<'v>>(
665 enum_definition: &'v EnumDef<'v>,
666 generics: &'v Generics<'v>,
669 visitor.visit_id(item_id);
670 walk_list!(visitor, visit_variant, enum_definition.variants, generics, item_id);
673 pub fn walk_variant<'v, V: Visitor<'v>>(
675 variant: &'v Variant<'v>,
676 generics: &'v Generics<'v>,
677 parent_item_id: HirId,
679 visitor.visit_ident(variant.ident);
680 visitor.visit_id(variant.id);
681 visitor.visit_variant_data(
688 walk_list!(visitor, visit_anon_const, &variant.disr_expr);
689 walk_list!(visitor, visit_attribute, variant.attrs);
692 pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty<'v>) {
693 visitor.visit_id(typ.hir_id);
696 TyKind::Slice(ref ty) => visitor.visit_ty(ty),
697 TyKind::Ptr(ref mutable_type) => visitor.visit_ty(&mutable_type.ty),
698 TyKind::Rptr(ref lifetime, ref mutable_type) => {
699 visitor.visit_lifetime(lifetime);
700 visitor.visit_ty(&mutable_type.ty)
703 TyKind::Tup(tuple_element_types) => {
704 walk_list!(visitor, visit_ty, tuple_element_types);
706 TyKind::BareFn(ref function_declaration) => {
707 walk_list!(visitor, visit_generic_param, function_declaration.generic_params);
708 visitor.visit_fn_decl(&function_declaration.decl);
710 TyKind::Path(ref qpath) => {
711 visitor.visit_qpath(qpath, typ.hir_id, typ.span);
713 TyKind::OpaqueDef(item_id, lifetimes) => {
714 visitor.visit_nested_item(item_id);
715 walk_list!(visitor, visit_generic_arg, lifetimes);
717 TyKind::Array(ref ty, ref length) => {
718 visitor.visit_ty(ty);
719 visitor.visit_anon_const(length)
721 TyKind::TraitObject(bounds, ref lifetime) => {
722 for bound in bounds {
723 visitor.visit_poly_trait_ref(bound, TraitBoundModifier::None);
725 visitor.visit_lifetime(lifetime);
727 TyKind::Typeof(ref expression) => visitor.visit_anon_const(expression),
728 TyKind::Infer | TyKind::Err => {}
732 pub fn walk_qpath<'v, V: Visitor<'v>>(
734 qpath: &'v QPath<'v>,
739 QPath::Resolved(ref maybe_qself, ref path) => {
740 walk_list!(visitor, visit_ty, maybe_qself);
741 visitor.visit_path(path, id)
743 QPath::TypeRelative(ref qself, ref segment) => {
744 visitor.visit_ty(qself);
745 visitor.visit_path_segment(span, segment);
747 QPath::LangItem(..) => {}
751 pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>) {
752 for segment in path.segments {
753 visitor.visit_path_segment(path.span, segment);
757 pub fn walk_path_segment<'v, V: Visitor<'v>>(
760 segment: &'v PathSegment<'v>,
762 visitor.visit_ident(segment.ident);
763 walk_list!(visitor, visit_id, segment.hir_id);
764 if let Some(ref args) = segment.args {
765 visitor.visit_generic_args(path_span, args);
769 pub fn walk_generic_args<'v, V: Visitor<'v>>(
772 generic_args: &'v GenericArgs<'v>,
774 walk_list!(visitor, visit_generic_arg, generic_args.args);
775 walk_list!(visitor, visit_assoc_type_binding, generic_args.bindings);
778 pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(
780 type_binding: &'v TypeBinding<'v>,
782 visitor.visit_id(type_binding.hir_id);
783 visitor.visit_ident(type_binding.ident);
784 visitor.visit_generic_args(type_binding.span, type_binding.gen_args);
785 match type_binding.kind {
786 TypeBindingKind::Equality { ref ty } => {
787 visitor.visit_ty(ty);
789 TypeBindingKind::Constraint { bounds } => {
790 walk_list!(visitor, visit_param_bound, bounds);
795 pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat<'v>) {
796 visitor.visit_id(pattern.hir_id);
798 PatKind::TupleStruct(ref qpath, children, _) => {
799 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
800 walk_list!(visitor, visit_pat, children);
802 PatKind::Path(ref qpath) => {
803 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
805 PatKind::Struct(ref qpath, fields, _) => {
806 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
807 for field in fields {
808 visitor.visit_id(field.hir_id);
809 visitor.visit_ident(field.ident);
810 visitor.visit_pat(&field.pat)
813 PatKind::Or(pats) => walk_list!(visitor, visit_pat, pats),
814 PatKind::Tuple(tuple_elements, _) => {
815 walk_list!(visitor, visit_pat, tuple_elements);
817 PatKind::Box(ref subpattern) | PatKind::Ref(ref subpattern, _) => {
818 visitor.visit_pat(subpattern)
820 PatKind::Binding(_, _hir_id, ident, ref optional_subpattern) => {
821 visitor.visit_ident(ident);
822 walk_list!(visitor, visit_pat, optional_subpattern);
824 PatKind::Lit(ref expression) => visitor.visit_expr(expression),
825 PatKind::Range(ref lower_bound, ref upper_bound, _) => {
826 walk_list!(visitor, visit_expr, lower_bound);
827 walk_list!(visitor, visit_expr, upper_bound);
830 PatKind::Slice(prepatterns, ref slice_pattern, postpatterns) => {
831 walk_list!(visitor, visit_pat, prepatterns);
832 walk_list!(visitor, visit_pat, slice_pattern);
833 walk_list!(visitor, visit_pat, postpatterns);
838 pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V, foreign_item: &'v ForeignItem<'v>) {
839 visitor.visit_id(foreign_item.hir_id);
840 visitor.visit_vis(&foreign_item.vis);
841 visitor.visit_ident(foreign_item.ident);
843 match foreign_item.kind {
844 ForeignItemKind::Fn(ref function_declaration, param_names, ref generics) => {
845 visitor.visit_generics(generics);
846 visitor.visit_fn_decl(function_declaration);
847 for ¶m_name in param_names {
848 visitor.visit_ident(param_name);
851 ForeignItemKind::Static(ref typ, _) => visitor.visit_ty(typ),
852 ForeignItemKind::Type => (),
855 walk_list!(visitor, visit_attribute, foreign_item.attrs);
858 pub fn walk_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v GenericBound<'v>) {
860 GenericBound::Trait(ref typ, modifier) => {
861 visitor.visit_poly_trait_ref(typ, modifier);
863 GenericBound::LangItemTrait(_, span, hir_id, args) => {
864 visitor.visit_id(hir_id);
865 visitor.visit_generic_args(span, args);
867 GenericBound::Outlives(ref lifetime) => visitor.visit_lifetime(lifetime),
871 pub fn walk_generic_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v GenericParam<'v>) {
872 visitor.visit_id(param.hir_id);
873 walk_list!(visitor, visit_attribute, param.attrs);
875 ParamName::Plain(ident) => visitor.visit_ident(ident),
876 ParamName::Error | ParamName::Fresh(_) => {}
879 GenericParamKind::Lifetime { .. } => {}
880 GenericParamKind::Type { ref default, .. } => walk_list!(visitor, visit_ty, default),
881 GenericParamKind::Const { ref ty, ref default } => {
882 visitor.visit_ty(ty);
883 if let Some(ref default) = default {
884 visitor.visit_anon_const(default);
888 walk_list!(visitor, visit_param_bound, param.bounds);
891 pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics<'v>) {
892 walk_list!(visitor, visit_generic_param, generics.params);
893 walk_list!(visitor, visit_where_predicate, generics.where_clause.predicates);
896 pub fn walk_where_predicate<'v, V: Visitor<'v>>(
898 predicate: &'v WherePredicate<'v>,
901 WherePredicate::BoundPredicate(WhereBoundPredicate {
904 bound_generic_params,
907 visitor.visit_ty(bounded_ty);
908 walk_list!(visitor, visit_param_bound, bounds);
909 walk_list!(visitor, visit_generic_param, bound_generic_params);
911 WherePredicate::RegionPredicate(WhereRegionPredicate { ref lifetime, bounds, .. }) => {
912 visitor.visit_lifetime(lifetime);
913 walk_list!(visitor, visit_param_bound, bounds);
915 WherePredicate::EqPredicate(WhereEqPredicate {
916 hir_id, ref lhs_ty, ref rhs_ty, ..
918 visitor.visit_id(hir_id);
919 visitor.visit_ty(lhs_ty);
920 visitor.visit_ty(rhs_ty);
925 pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FnRetTy<'v>) {
926 if let FnRetTy::Return(ref output_ty) = *ret_ty {
927 visitor.visit_ty(output_ty)
931 pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl<'v>) {
932 for ty in function_declaration.inputs {
935 walk_fn_ret_ty(visitor, &function_declaration.output)
938 pub fn walk_fn_kind<'v, V: Visitor<'v>>(visitor: &mut V, function_kind: FnKind<'v>) {
939 match function_kind {
940 FnKind::ItemFn(_, generics, ..) => {
941 visitor.visit_generics(generics);
943 FnKind::Method(..) | FnKind::Closure(_) => {}
947 pub fn walk_fn<'v, V: Visitor<'v>>(
949 function_kind: FnKind<'v>,
950 function_declaration: &'v FnDecl<'v>,
955 visitor.visit_id(id);
956 visitor.visit_fn_decl(function_declaration);
957 walk_fn_kind(visitor, function_kind);
958 visitor.visit_nested_body(body_id)
961 pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem<'v>) {
962 visitor.visit_ident(trait_item.ident);
963 walk_list!(visitor, visit_attribute, trait_item.attrs);
964 visitor.visit_generics(&trait_item.generics);
965 match trait_item.kind {
966 TraitItemKind::Const(ref ty, default) => {
967 visitor.visit_id(trait_item.hir_id);
968 visitor.visit_ty(ty);
969 walk_list!(visitor, visit_nested_body, default);
971 TraitItemKind::Fn(ref sig, TraitFn::Required(param_names)) => {
972 visitor.visit_id(trait_item.hir_id);
973 visitor.visit_fn_decl(&sig.decl);
974 for ¶m_name in param_names {
975 visitor.visit_ident(param_name);
978 TraitItemKind::Fn(ref sig, TraitFn::Provided(body_id)) => {
980 FnKind::Method(trait_item.ident, sig, None, &trait_item.attrs),
987 TraitItemKind::Type(bounds, ref default) => {
988 visitor.visit_id(trait_item.hir_id);
989 walk_list!(visitor, visit_param_bound, bounds);
990 walk_list!(visitor, visit_ty, default);
995 pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref: &'v TraitItemRef) {
996 // N.B., deliberately force a compilation error if/when new fields are added.
997 let TraitItemRef { id, ident, ref kind, span: _, ref defaultness } = *trait_item_ref;
998 visitor.visit_nested_trait_item(id);
999 visitor.visit_ident(ident);
1000 visitor.visit_associated_item_kind(kind);
1001 visitor.visit_defaultness(defaultness);
1004 pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem<'v>) {
1005 // N.B., deliberately force a compilation error if/when new fields are added.
1017 visitor.visit_ident(ident);
1018 visitor.visit_vis(vis);
1019 visitor.visit_defaultness(defaultness);
1020 walk_list!(visitor, visit_attribute, attrs);
1021 visitor.visit_generics(generics);
1023 ImplItemKind::Const(ref ty, body) => {
1024 visitor.visit_id(impl_item.hir_id);
1025 visitor.visit_ty(ty);
1026 visitor.visit_nested_body(body);
1028 ImplItemKind::Fn(ref sig, body_id) => {
1030 FnKind::Method(impl_item.ident, sig, Some(&impl_item.vis), &impl_item.attrs),
1037 ImplItemKind::TyAlias(ref ty) => {
1038 visitor.visit_id(impl_item.hir_id);
1039 visitor.visit_ty(ty);
1044 pub fn walk_foreign_item_ref<'v, V: Visitor<'v>>(
1046 foreign_item_ref: &'v ForeignItemRef<'v>,
1048 // N.B., deliberately force a compilation error if/when new fields are added.
1049 let ForeignItemRef { id, ident, span: _, ref vis } = *foreign_item_ref;
1050 visitor.visit_nested_foreign_item(id);
1051 visitor.visit_ident(ident);
1052 visitor.visit_vis(vis);
1055 pub fn walk_impl_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, impl_item_ref: &'v ImplItemRef<'v>) {
1056 // N.B., deliberately force a compilation error if/when new fields are added.
1057 let ImplItemRef { id, ident, ref kind, span: _, ref vis, ref defaultness } = *impl_item_ref;
1058 visitor.visit_nested_impl_item(id);
1059 visitor.visit_ident(ident);
1060 visitor.visit_associated_item_kind(kind);
1061 visitor.visit_vis(vis);
1062 visitor.visit_defaultness(defaultness);
1065 pub fn walk_struct_def<'v, V: Visitor<'v>>(
1067 struct_definition: &'v VariantData<'v>,
1069 walk_list!(visitor, visit_id, struct_definition.ctor_hir_id());
1070 walk_list!(visitor, visit_struct_field, struct_definition.fields());
1073 pub fn walk_struct_field<'v, V: Visitor<'v>>(visitor: &mut V, struct_field: &'v StructField<'v>) {
1074 visitor.visit_id(struct_field.hir_id);
1075 visitor.visit_vis(&struct_field.vis);
1076 visitor.visit_ident(struct_field.ident);
1077 visitor.visit_ty(&struct_field.ty);
1078 walk_list!(visitor, visit_attribute, struct_field.attrs);
1081 pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block<'v>) {
1082 visitor.visit_id(block.hir_id);
1083 walk_list!(visitor, visit_stmt, block.stmts);
1084 walk_list!(visitor, visit_expr, &block.expr);
1087 pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt<'v>) {
1088 visitor.visit_id(statement.hir_id);
1089 match statement.kind {
1090 StmtKind::Local(ref local) => visitor.visit_local(local),
1091 StmtKind::Item(item) => visitor.visit_nested_item(item),
1092 StmtKind::Expr(ref expression) | StmtKind::Semi(ref expression) => {
1093 visitor.visit_expr(expression)
1098 pub fn walk_anon_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v AnonConst) {
1099 visitor.visit_id(constant.hir_id);
1100 visitor.visit_nested_body(constant.body);
1103 pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>) {
1104 visitor.visit_id(expression.hir_id);
1105 walk_list!(visitor, visit_attribute, expression.attrs.iter());
1106 match expression.kind {
1107 ExprKind::Box(ref subexpression) => visitor.visit_expr(subexpression),
1108 ExprKind::Array(subexpressions) => {
1109 walk_list!(visitor, visit_expr, subexpressions);
1111 ExprKind::ConstBlock(ref anon_const) => visitor.visit_anon_const(anon_const),
1112 ExprKind::Repeat(ref element, ref count) => {
1113 visitor.visit_expr(element);
1114 visitor.visit_anon_const(count)
1116 ExprKind::Struct(ref qpath, fields, ref optional_base) => {
1117 visitor.visit_qpath(qpath, expression.hir_id, expression.span);
1118 for field in fields {
1119 visitor.visit_id(field.hir_id);
1120 visitor.visit_ident(field.ident);
1121 visitor.visit_expr(&field.expr)
1123 walk_list!(visitor, visit_expr, optional_base);
1125 ExprKind::Tup(subexpressions) => {
1126 walk_list!(visitor, visit_expr, subexpressions);
1128 ExprKind::Call(ref callee_expression, arguments) => {
1129 visitor.visit_expr(callee_expression);
1130 walk_list!(visitor, visit_expr, arguments);
1132 ExprKind::MethodCall(ref segment, _, arguments, _) => {
1133 visitor.visit_path_segment(expression.span, segment);
1134 walk_list!(visitor, visit_expr, arguments);
1136 ExprKind::Binary(_, ref left_expression, ref right_expression) => {
1137 visitor.visit_expr(left_expression);
1138 visitor.visit_expr(right_expression)
1140 ExprKind::AddrOf(_, _, ref subexpression) | ExprKind::Unary(_, ref subexpression) => {
1141 visitor.visit_expr(subexpression)
1143 ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => {
1144 visitor.visit_expr(subexpression);
1145 visitor.visit_ty(typ)
1147 ExprKind::DropTemps(ref subexpression) => {
1148 visitor.visit_expr(subexpression);
1150 ExprKind::If(ref cond, ref then, ref else_opt) => {
1151 visitor.visit_expr(cond);
1152 visitor.visit_expr(then);
1153 walk_list!(visitor, visit_expr, else_opt);
1155 ExprKind::Loop(ref block, ref opt_label, _, _) => {
1156 walk_list!(visitor, visit_label, opt_label);
1157 visitor.visit_block(block);
1159 ExprKind::Match(ref subexpression, arms, _) => {
1160 visitor.visit_expr(subexpression);
1161 walk_list!(visitor, visit_arm, arms);
1163 ExprKind::Closure(_, ref function_declaration, body, _fn_decl_span, _gen) => visitor
1165 FnKind::Closure(&expression.attrs),
1166 function_declaration,
1171 ExprKind::Block(ref block, ref opt_label) => {
1172 walk_list!(visitor, visit_label, opt_label);
1173 visitor.visit_block(block);
1175 ExprKind::Assign(ref lhs, ref rhs, _) => {
1176 visitor.visit_expr(rhs);
1177 visitor.visit_expr(lhs)
1179 ExprKind::AssignOp(_, ref left_expression, ref right_expression) => {
1180 visitor.visit_expr(right_expression);
1181 visitor.visit_expr(left_expression);
1183 ExprKind::Field(ref subexpression, ident) => {
1184 visitor.visit_expr(subexpression);
1185 visitor.visit_ident(ident);
1187 ExprKind::Index(ref main_expression, ref index_expression) => {
1188 visitor.visit_expr(main_expression);
1189 visitor.visit_expr(index_expression)
1191 ExprKind::Path(ref qpath) => {
1192 visitor.visit_qpath(qpath, expression.hir_id, expression.span);
1194 ExprKind::Break(ref destination, ref opt_expr) => {
1195 walk_list!(visitor, visit_label, &destination.label);
1196 walk_list!(visitor, visit_expr, opt_expr);
1198 ExprKind::Continue(ref destination) => {
1199 walk_list!(visitor, visit_label, &destination.label);
1201 ExprKind::Ret(ref optional_expression) => {
1202 walk_list!(visitor, visit_expr, optional_expression);
1204 ExprKind::InlineAsm(ref asm) => {
1205 for (op, _op_sp) in asm.operands {
1207 InlineAsmOperand::In { expr, .. }
1208 | InlineAsmOperand::InOut { expr, .. }
1209 | InlineAsmOperand::Const { expr, .. }
1210 | InlineAsmOperand::Sym { expr, .. } => visitor.visit_expr(expr),
1211 InlineAsmOperand::Out { expr, .. } => {
1212 if let Some(expr) = expr {
1213 visitor.visit_expr(expr);
1216 InlineAsmOperand::SplitInOut { in_expr, out_expr, .. } => {
1217 visitor.visit_expr(in_expr);
1218 if let Some(out_expr) = out_expr {
1219 visitor.visit_expr(out_expr);
1225 ExprKind::LlvmInlineAsm(ref asm) => {
1226 walk_list!(visitor, visit_expr, asm.outputs_exprs);
1227 walk_list!(visitor, visit_expr, asm.inputs_exprs);
1229 ExprKind::Yield(ref subexpression, _) => {
1230 visitor.visit_expr(subexpression);
1232 ExprKind::Lit(_) | ExprKind::Err => {}
1236 pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm<'v>) {
1237 visitor.visit_id(arm.hir_id);
1238 visitor.visit_pat(&arm.pat);
1239 if let Some(ref g) = arm.guard {
1241 Guard::If(ref e) => visitor.visit_expr(e),
1242 Guard::IfLet(ref pat, ref e) => {
1243 visitor.visit_pat(pat);
1244 visitor.visit_expr(e);
1248 visitor.visit_expr(&arm.body);
1249 walk_list!(visitor, visit_attribute, arm.attrs);
1252 pub fn walk_vis<'v, V: Visitor<'v>>(visitor: &mut V, vis: &'v Visibility<'v>) {
1253 if let VisibilityKind::Restricted { ref path, hir_id } = vis.node {
1254 visitor.visit_id(hir_id);
1255 visitor.visit_path(path, hir_id)
1259 pub fn walk_associated_item_kind<'v, V: Visitor<'v>>(_: &mut V, _: &'v AssocItemKind) {
1260 // No visitable content here: this fn exists so you can call it if
1261 // the right thing to do, should content be added in the future,
1262 // would be to walk it.
1265 pub fn walk_defaultness<'v, V: Visitor<'v>>(_: &mut V, _: &'v Defaultness) {
1266 // No visitable content here: this fn exists so you can call it if
1267 // the right thing to do, should content be added in the future,
1268 // would be to walk it.