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>),
107 Method(Ident, &'a FnSig<'a>, Option<&'a Visibility<'a>>),
113 impl<'a> FnKind<'a> {
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: ItemId) -> &'hir Item<'hir>;
129 fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir>;
130 fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem<'hir>;
131 fn foreign_item(&self, id: ForeignItemId) -> &'hir ForeignItem<'hir>;
134 /// An erased version of `Map<'hir>`, using dynamic dispatch.
135 /// NOTE: This type is effectively only usable with `NestedVisitorMap::None`.
136 pub struct ErasedMap<'hir>(&'hir dyn Map<'hir>);
138 impl<'hir> Map<'hir> for ErasedMap<'hir> {
139 fn find(&self, _: HirId) -> Option<Node<'hir>> {
142 fn body(&self, id: BodyId) -> &'hir Body<'hir> {
145 fn item(&self, id: ItemId) -> &'hir Item<'hir> {
148 fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir> {
149 self.0.trait_item(id)
151 fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem<'hir> {
154 fn foreign_item(&self, id: ForeignItemId) -> &'hir ForeignItem<'hir> {
155 self.0.foreign_item(id)
159 /// Specifies what nested things a visitor wants to visit. The most
160 /// common choice is `OnlyBodies`, which will cause the visitor to
161 /// visit fn bodies for fns that it encounters, but skip over nested
162 /// item-like things.
164 /// See the comments on `ItemLikeVisitor` for more details on the overall
166 pub enum NestedVisitorMap<M> {
167 /// Do not visit any nested things. When you add a new
168 /// "non-nested" thing, you will want to audit such uses to see if
169 /// they remain valid.
171 /// Use this if you are only walking some particular kind of tree
172 /// (i.e., a type, or fn signature) and you don't want to thread a
176 /// Do not visit nested item-like things, but visit nested things
177 /// that are inside of an item-like.
179 /// **This is the most common choice.** A very common pattern is
180 /// to use `visit_all_item_likes()` as an outer loop,
181 /// and to have the visitor that visits the contents of each item
182 /// using this setting.
185 /// Visits all nested things, including item-likes.
187 /// **This is an unusual choice.** It is used when you want to
188 /// process everything within their lexical context. Typically you
189 /// kick off the visit by doing `walk_krate()`.
193 impl<M> NestedVisitorMap<M> {
194 /// Returns the map to use for an "intra item-like" thing (if any).
195 /// E.g., function body.
196 fn intra(self) -> Option<M> {
198 NestedVisitorMap::None => None,
199 NestedVisitorMap::OnlyBodies(map) => Some(map),
200 NestedVisitorMap::All(map) => Some(map),
204 /// Returns the map to use for an "item-like" thing (if any).
205 /// E.g., item, impl-item.
206 fn inter(self) -> Option<M> {
208 NestedVisitorMap::None => None,
209 NestedVisitorMap::OnlyBodies(_) => None,
210 NestedVisitorMap::All(map) => Some(map),
215 /// Each method of the Visitor trait is a hook to be potentially
216 /// overridden. Each method's default implementation recursively visits
217 /// the substructure of the input via the corresponding `walk` method;
218 /// e.g., the `visit_mod` method by default calls `intravisit::walk_mod`.
220 /// Note that this visitor does NOT visit nested items by default
221 /// (this is why the module is called `intravisit`, to distinguish it
222 /// from the AST's `visit` module, which acts differently). If you
223 /// simply want to visit all items in the crate in some order, you
224 /// should call `Crate::visit_all_items`. Otherwise, see the comment
225 /// on `visit_nested_item` for details on how to visit nested items.
227 /// If you want to ensure that your code handles every variant
228 /// explicitly, you need to override each method. (And you also need
229 /// to monitor future changes to `Visitor` in case a new method with a
230 /// new default implementation gets introduced.)
231 pub trait Visitor<'v>: Sized {
234 ///////////////////////////////////////////////////////////////////////////
237 /// The default versions of the `visit_nested_XXX` routines invoke
238 /// this method to get a map to use. By selecting an enum variant,
239 /// you control which kinds of nested HIR are visited; see
240 /// `NestedVisitorMap` for details. By "nested HIR", we are
241 /// referring to bits of HIR that are not directly embedded within
242 /// one another but rather indirectly, through a table in the
243 /// crate. This is done to control dependencies during incremental
244 /// compilation: the non-inline bits of HIR can be tracked and
245 /// hashed separately.
247 /// **If for some reason you want the nested behavior, but don't
248 /// have a `Map` at your disposal:** then you should override the
249 /// `visit_nested_XXX` methods, and override this method to
250 /// `panic!()`. This way, if a new `visit_nested_XXX` variant is
251 /// added in the future, we will see the panic in your code and
252 /// fix it appropriately.
253 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map>;
255 /// Invoked when a nested item is encountered. By default does
256 /// nothing unless you override `nested_visit_map` to return other than
257 /// `None`, in which case it will walk the item. **You probably
258 /// don't want to override this method** -- instead, override
259 /// `nested_visit_map` or use the "shallow" or "deep" visit
260 /// patterns described on `itemlikevisit::ItemLikeVisitor`. The only
261 /// reason to override this method is if you want a nested pattern
262 /// but cannot supply a `Map`; see `nested_visit_map` for advice.
263 fn visit_nested_item(&mut self, id: ItemId) {
264 let opt_item = self.nested_visit_map().inter().map(|map| map.item(id));
265 walk_list!(self, visit_item, opt_item);
268 /// Like `visit_nested_item()`, but for trait items. See
269 /// `visit_nested_item()` for advice on when to override this
271 fn visit_nested_trait_item(&mut self, id: TraitItemId) {
272 let opt_item = self.nested_visit_map().inter().map(|map| map.trait_item(id));
273 walk_list!(self, visit_trait_item, opt_item);
276 /// Like `visit_nested_item()`, but for impl items. See
277 /// `visit_nested_item()` for advice on when to override this
279 fn visit_nested_impl_item(&mut self, id: ImplItemId) {
280 let opt_item = self.nested_visit_map().inter().map(|map| map.impl_item(id));
281 walk_list!(self, visit_impl_item, opt_item);
284 /// Like `visit_nested_item()`, but for foreign items. See
285 /// `visit_nested_item()` for advice on when to override this
287 fn visit_nested_foreign_item(&mut self, id: ForeignItemId) {
288 let opt_item = self.nested_visit_map().inter().map(|map| map.foreign_item(id));
289 walk_list!(self, visit_foreign_item, opt_item);
292 /// Invoked to visit the body of a function, method or closure. Like
293 /// visit_nested_item, does nothing by default unless you override
294 /// `nested_visit_map` to return other than `None`, in which case it will walk
296 fn visit_nested_body(&mut self, id: BodyId) {
297 let opt_body = self.nested_visit_map().intra().map(|map| map.body(id));
298 walk_list!(self, visit_body, opt_body);
301 fn visit_param(&mut self, param: &'v Param<'v>) {
302 walk_param(self, param)
305 /// Visits the top-level item and (optionally) nested items / impl items. See
306 /// `visit_nested_item` for details.
307 fn visit_item(&mut self, i: &'v Item<'v>) {
311 fn visit_body(&mut self, b: &'v Body<'v>) {
315 /// When invoking `visit_all_item_likes()`, you need to supply an
316 /// item-like visitor. This method converts a "intra-visit"
317 /// visitor into an item-like visitor that walks the entire tree.
318 /// If you use this, you probably don't want to process the
319 /// contents of nested item-like things, since the outer loop will
320 /// visit them as well.
321 fn as_deep_visitor(&mut self) -> DeepVisitor<'_, Self> {
322 DeepVisitor::new(self)
325 ///////////////////////////////////////////////////////////////////////////
327 fn visit_id(&mut self, _hir_id: HirId) {
330 fn visit_name(&mut self, _span: Span, _name: Symbol) {
333 fn visit_ident(&mut self, ident: Ident) {
334 walk_ident(self, ident)
336 fn visit_mod(&mut self, m: &'v Mod<'v>, _s: Span, n: HirId) {
339 fn visit_foreign_item(&mut self, i: &'v ForeignItem<'v>) {
340 walk_foreign_item(self, i)
342 fn visit_local(&mut self, l: &'v Local<'v>) {
345 fn visit_block(&mut self, b: &'v Block<'v>) {
348 fn visit_stmt(&mut self, s: &'v Stmt<'v>) {
351 fn visit_arm(&mut self, a: &'v Arm<'v>) {
354 fn visit_pat(&mut self, p: &'v Pat<'v>) {
357 fn visit_anon_const(&mut self, c: &'v AnonConst) {
358 walk_anon_const(self, c)
360 fn visit_expr(&mut self, ex: &'v Expr<'v>) {
363 fn visit_ty(&mut self, t: &'v Ty<'v>) {
366 fn visit_generic_param(&mut self, p: &'v GenericParam<'v>) {
367 walk_generic_param(self, p)
369 fn visit_const_param_default(&mut self, _param: HirId, ct: &'v AnonConst) {
370 walk_const_param_default(self, ct)
372 fn visit_generics(&mut self, g: &'v Generics<'v>) {
373 walk_generics(self, g)
375 fn visit_where_predicate(&mut self, predicate: &'v WherePredicate<'v>) {
376 walk_where_predicate(self, predicate)
378 fn visit_fn_decl(&mut self, fd: &'v FnDecl<'v>) {
379 walk_fn_decl(self, fd)
381 fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl<'v>, b: BodyId, s: Span, id: HirId) {
382 walk_fn(self, fk, fd, b, s, id)
384 fn visit_use(&mut self, path: &'v Path<'v>, hir_id: HirId) {
385 walk_use(self, path, hir_id)
387 fn visit_trait_item(&mut self, ti: &'v TraitItem<'v>) {
388 walk_trait_item(self, ti)
390 fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) {
391 walk_trait_item_ref(self, ii)
393 fn visit_impl_item(&mut self, ii: &'v ImplItem<'v>) {
394 walk_impl_item(self, ii)
396 fn visit_foreign_item_ref(&mut self, ii: &'v ForeignItemRef<'v>) {
397 walk_foreign_item_ref(self, ii)
399 fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef<'v>) {
400 walk_impl_item_ref(self, ii)
402 fn visit_trait_ref(&mut self, t: &'v TraitRef<'v>) {
403 walk_trait_ref(self, t)
405 fn visit_param_bound(&mut self, bounds: &'v GenericBound<'v>) {
406 walk_param_bound(self, bounds)
408 fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef<'v>, m: TraitBoundModifier) {
409 walk_poly_trait_ref(self, t, m)
411 fn visit_variant_data(
413 s: &'v VariantData<'v>,
419 walk_struct_def(self, s)
421 fn visit_field_def(&mut self, s: &'v FieldDef<'v>) {
422 walk_field_def(self, s)
426 enum_definition: &'v EnumDef<'v>,
427 generics: &'v Generics<'v>,
431 walk_enum_def(self, enum_definition, generics, item_id)
433 fn visit_variant(&mut self, v: &'v Variant<'v>, g: &'v Generics<'v>, item_id: HirId) {
434 walk_variant(self, v, g, item_id)
436 fn visit_label(&mut self, label: &'v Label) {
437 walk_label(self, label)
439 fn visit_generic_arg(&mut self, generic_arg: &'v GenericArg<'v>) {
441 GenericArg::Lifetime(lt) => self.visit_lifetime(lt),
442 GenericArg::Type(ty) => self.visit_ty(ty),
443 GenericArg::Const(ct) => self.visit_anon_const(&ct.value),
446 fn visit_lifetime(&mut self, lifetime: &'v Lifetime) {
447 walk_lifetime(self, lifetime)
449 fn visit_qpath(&mut self, qpath: &'v QPath<'v>, id: HirId, span: Span) {
450 walk_qpath(self, qpath, id, span)
452 fn visit_path(&mut self, path: &'v Path<'v>, _id: HirId) {
453 walk_path(self, path)
455 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment<'v>) {
456 walk_path_segment(self, path_span, path_segment)
458 fn visit_generic_args(&mut self, path_span: Span, generic_args: &'v GenericArgs<'v>) {
459 walk_generic_args(self, path_span, generic_args)
461 fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding<'v>) {
462 walk_assoc_type_binding(self, type_binding)
464 fn visit_attribute(&mut self, _id: HirId, _attr: &'v Attribute) {}
465 fn visit_macro_def(&mut self, macro_def: &'v MacroDef<'v>) {
466 walk_macro_def(self, macro_def)
468 fn visit_vis(&mut self, vis: &'v Visibility<'v>) {
471 fn visit_associated_item_kind(&mut self, kind: &'v AssocItemKind) {
472 walk_associated_item_kind(self, kind);
474 fn visit_defaultness(&mut self, defaultness: &'v Defaultness) {
475 walk_defaultness(self, defaultness);
479 /// Walks the contents of a crate. See also `Crate::visit_all_items`.
480 pub fn walk_crate<'v, V: Visitor<'v>>(visitor: &mut V, krate: &'v Crate<'v>) {
481 visitor.visit_mod(&krate.item.module, krate.item.span, CRATE_HIR_ID);
482 walk_list!(visitor, visit_macro_def, krate.exported_macros);
483 for (&id, attrs) in krate.attrs.iter() {
485 visitor.visit_attribute(id, a)
490 pub fn walk_macro_def<'v, V: Visitor<'v>>(visitor: &mut V, macro_def: &'v MacroDef<'v>) {
491 visitor.visit_id(macro_def.hir_id());
492 visitor.visit_ident(macro_def.ident);
495 pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod<'v>, mod_hir_id: HirId) {
496 visitor.visit_id(mod_hir_id);
497 for &item_id in module.item_ids {
498 visitor.visit_nested_item(item_id);
502 pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body<'v>) {
503 walk_list!(visitor, visit_param, body.params);
504 visitor.visit_expr(&body.value);
507 pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local<'v>) {
508 // Intentionally visiting the expr first - the initialization expr
509 // dominates the local's definition.
510 walk_list!(visitor, visit_expr, &local.init);
511 visitor.visit_id(local.hir_id);
512 visitor.visit_pat(&local.pat);
513 walk_list!(visitor, visit_ty, &local.ty);
516 pub fn walk_ident<'v, V: Visitor<'v>>(visitor: &mut V, ident: Ident) {
517 visitor.visit_name(ident.span, ident.name);
520 pub fn walk_label<'v, V: Visitor<'v>>(visitor: &mut V, label: &'v Label) {
521 visitor.visit_ident(label.ident);
524 pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) {
525 visitor.visit_id(lifetime.hir_id);
526 match lifetime.name {
527 LifetimeName::Param(ParamName::Plain(ident)) => {
528 visitor.visit_ident(ident);
530 LifetimeName::Param(ParamName::Fresh(_))
531 | LifetimeName::Param(ParamName::Error)
532 | LifetimeName::Static
533 | LifetimeName::Error
534 | LifetimeName::Implicit
535 | LifetimeName::ImplicitObjectLifetimeDefault
536 | LifetimeName::Underscore => {}
540 pub fn walk_poly_trait_ref<'v, V: Visitor<'v>>(
542 trait_ref: &'v PolyTraitRef<'v>,
543 _modifier: TraitBoundModifier,
545 walk_list!(visitor, visit_generic_param, trait_ref.bound_generic_params);
546 visitor.visit_trait_ref(&trait_ref.trait_ref);
549 pub fn walk_trait_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_ref: &'v TraitRef<'v>) {
550 visitor.visit_id(trait_ref.hir_ref_id);
551 visitor.visit_path(&trait_ref.path, trait_ref.hir_ref_id)
554 pub fn walk_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v Param<'v>) {
555 visitor.visit_id(param.hir_id);
556 visitor.visit_pat(¶m.pat);
559 pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) {
560 visitor.visit_vis(&item.vis);
561 visitor.visit_ident(item.ident);
563 ItemKind::ExternCrate(orig_name) => {
564 visitor.visit_id(item.hir_id());
565 if let Some(orig_name) = orig_name {
566 visitor.visit_name(item.span, orig_name);
569 ItemKind::Use(ref path, _) => {
570 visitor.visit_use(path, item.hir_id());
572 ItemKind::Static(ref typ, _, body) | ItemKind::Const(ref typ, body) => {
573 visitor.visit_id(item.hir_id());
574 visitor.visit_ty(typ);
575 visitor.visit_nested_body(body);
577 ItemKind::Fn(ref sig, ref generics, body_id) => visitor.visit_fn(
578 FnKind::ItemFn(item.ident, generics, sig.header, &item.vis),
584 ItemKind::Mod(ref module) => {
585 // `visit_mod()` takes care of visiting the `Item`'s `HirId`.
586 visitor.visit_mod(module, item.span, item.hir_id())
588 ItemKind::ForeignMod { abi: _, items } => {
589 visitor.visit_id(item.hir_id());
590 walk_list!(visitor, visit_foreign_item_ref, items);
592 ItemKind::GlobalAsm(_) => {
593 visitor.visit_id(item.hir_id());
595 ItemKind::TyAlias(ref ty, ref generics) => {
596 visitor.visit_id(item.hir_id());
597 visitor.visit_ty(ty);
598 visitor.visit_generics(generics)
600 ItemKind::OpaqueTy(OpaqueTy { ref generics, bounds, .. }) => {
601 visitor.visit_id(item.hir_id());
602 walk_generics(visitor, generics);
603 walk_list!(visitor, visit_param_bound, bounds);
605 ItemKind::Enum(ref enum_definition, ref generics) => {
606 visitor.visit_generics(generics);
607 // `visit_enum_def()` takes care of visiting the `Item`'s `HirId`.
608 visitor.visit_enum_def(enum_definition, generics, item.hir_id(), item.span)
610 ItemKind::Impl(Impl {
621 visitor.visit_id(item.hir_id());
622 visitor.visit_generics(generics);
623 walk_list!(visitor, visit_trait_ref, of_trait);
624 visitor.visit_ty(self_ty);
625 walk_list!(visitor, visit_impl_item_ref, items);
627 ItemKind::Struct(ref struct_definition, ref generics)
628 | ItemKind::Union(ref struct_definition, ref generics) => {
629 visitor.visit_generics(generics);
630 visitor.visit_id(item.hir_id());
631 visitor.visit_variant_data(
639 ItemKind::Trait(.., ref generics, bounds, trait_item_refs) => {
640 visitor.visit_id(item.hir_id());
641 visitor.visit_generics(generics);
642 walk_list!(visitor, visit_param_bound, bounds);
643 walk_list!(visitor, visit_trait_item_ref, trait_item_refs);
645 ItemKind::TraitAlias(ref generics, bounds) => {
646 visitor.visit_id(item.hir_id());
647 visitor.visit_generics(generics);
648 walk_list!(visitor, visit_param_bound, bounds);
653 pub fn walk_use<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>, hir_id: HirId) {
654 visitor.visit_id(hir_id);
655 visitor.visit_path(path, hir_id);
658 pub fn walk_enum_def<'v, V: Visitor<'v>>(
660 enum_definition: &'v EnumDef<'v>,
661 generics: &'v Generics<'v>,
664 visitor.visit_id(item_id);
665 walk_list!(visitor, visit_variant, enum_definition.variants, generics, item_id);
668 pub fn walk_variant<'v, V: Visitor<'v>>(
670 variant: &'v Variant<'v>,
671 generics: &'v Generics<'v>,
672 parent_item_id: HirId,
674 visitor.visit_ident(variant.ident);
675 visitor.visit_id(variant.id);
676 visitor.visit_variant_data(
683 walk_list!(visitor, visit_anon_const, &variant.disr_expr);
686 pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty<'v>) {
687 visitor.visit_id(typ.hir_id);
690 TyKind::Slice(ref ty) => visitor.visit_ty(ty),
691 TyKind::Ptr(ref mutable_type) => visitor.visit_ty(&mutable_type.ty),
692 TyKind::Rptr(ref lifetime, ref mutable_type) => {
693 visitor.visit_lifetime(lifetime);
694 visitor.visit_ty(&mutable_type.ty)
697 TyKind::Tup(tuple_element_types) => {
698 walk_list!(visitor, visit_ty, tuple_element_types);
700 TyKind::BareFn(ref function_declaration) => {
701 walk_list!(visitor, visit_generic_param, function_declaration.generic_params);
702 visitor.visit_fn_decl(&function_declaration.decl);
704 TyKind::Path(ref qpath) => {
705 visitor.visit_qpath(qpath, typ.hir_id, typ.span);
707 TyKind::OpaqueDef(item_id, lifetimes) => {
708 visitor.visit_nested_item(item_id);
709 walk_list!(visitor, visit_generic_arg, lifetimes);
711 TyKind::Array(ref ty, ref length) => {
712 visitor.visit_ty(ty);
713 visitor.visit_anon_const(length)
715 TyKind::TraitObject(bounds, ref lifetime, _syntax) => {
716 for bound in bounds {
717 visitor.visit_poly_trait_ref(bound, TraitBoundModifier::None);
719 visitor.visit_lifetime(lifetime);
721 TyKind::Typeof(ref expression) => visitor.visit_anon_const(expression),
722 TyKind::Infer | TyKind::Err => {}
726 pub fn walk_qpath<'v, V: Visitor<'v>>(
728 qpath: &'v QPath<'v>,
733 QPath::Resolved(ref maybe_qself, ref path) => {
734 walk_list!(visitor, visit_ty, maybe_qself);
735 visitor.visit_path(path, id)
737 QPath::TypeRelative(ref qself, ref segment) => {
738 visitor.visit_ty(qself);
739 visitor.visit_path_segment(span, segment);
741 QPath::LangItem(..) => {}
745 pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>) {
746 for segment in path.segments {
747 visitor.visit_path_segment(path.span, segment);
751 pub fn walk_path_segment<'v, V: Visitor<'v>>(
754 segment: &'v PathSegment<'v>,
756 visitor.visit_ident(segment.ident);
757 walk_list!(visitor, visit_id, segment.hir_id);
758 if let Some(ref args) = segment.args {
759 visitor.visit_generic_args(path_span, args);
763 pub fn walk_generic_args<'v, V: Visitor<'v>>(
766 generic_args: &'v GenericArgs<'v>,
768 walk_list!(visitor, visit_generic_arg, generic_args.args);
769 walk_list!(visitor, visit_assoc_type_binding, generic_args.bindings);
772 pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(
774 type_binding: &'v TypeBinding<'v>,
776 visitor.visit_id(type_binding.hir_id);
777 visitor.visit_ident(type_binding.ident);
778 visitor.visit_generic_args(type_binding.span, type_binding.gen_args);
779 match type_binding.kind {
780 TypeBindingKind::Equality { ref ty } => {
781 visitor.visit_ty(ty);
783 TypeBindingKind::Constraint { bounds } => {
784 walk_list!(visitor, visit_param_bound, bounds);
789 pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat<'v>) {
790 visitor.visit_id(pattern.hir_id);
792 PatKind::TupleStruct(ref qpath, children, _) => {
793 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
794 walk_list!(visitor, visit_pat, children);
796 PatKind::Path(ref qpath) => {
797 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
799 PatKind::Struct(ref qpath, fields, _) => {
800 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
801 for field in fields {
802 visitor.visit_id(field.hir_id);
803 visitor.visit_ident(field.ident);
804 visitor.visit_pat(&field.pat)
807 PatKind::Or(pats) => walk_list!(visitor, visit_pat, pats),
808 PatKind::Tuple(tuple_elements, _) => {
809 walk_list!(visitor, visit_pat, tuple_elements);
811 PatKind::Box(ref subpattern) | PatKind::Ref(ref subpattern, _) => {
812 visitor.visit_pat(subpattern)
814 PatKind::Binding(_, _hir_id, ident, ref optional_subpattern) => {
815 visitor.visit_ident(ident);
816 walk_list!(visitor, visit_pat, optional_subpattern);
818 PatKind::Lit(ref expression) => visitor.visit_expr(expression),
819 PatKind::Range(ref lower_bound, ref upper_bound, _) => {
820 walk_list!(visitor, visit_expr, lower_bound);
821 walk_list!(visitor, visit_expr, upper_bound);
824 PatKind::Slice(prepatterns, ref slice_pattern, postpatterns) => {
825 walk_list!(visitor, visit_pat, prepatterns);
826 walk_list!(visitor, visit_pat, slice_pattern);
827 walk_list!(visitor, visit_pat, postpatterns);
832 pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V, foreign_item: &'v ForeignItem<'v>) {
833 visitor.visit_id(foreign_item.hir_id());
834 visitor.visit_vis(&foreign_item.vis);
835 visitor.visit_ident(foreign_item.ident);
837 match foreign_item.kind {
838 ForeignItemKind::Fn(ref function_declaration, param_names, ref generics) => {
839 visitor.visit_generics(generics);
840 visitor.visit_fn_decl(function_declaration);
841 for ¶m_name in param_names {
842 visitor.visit_ident(param_name);
845 ForeignItemKind::Static(ref typ, _) => visitor.visit_ty(typ),
846 ForeignItemKind::Type => (),
850 pub fn walk_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v GenericBound<'v>) {
852 GenericBound::Trait(ref typ, modifier) => {
853 visitor.visit_poly_trait_ref(typ, modifier);
855 GenericBound::LangItemTrait(_, span, hir_id, args) => {
856 visitor.visit_id(hir_id);
857 visitor.visit_generic_args(span, args);
859 GenericBound::Outlives(ref lifetime) => visitor.visit_lifetime(lifetime),
863 pub fn walk_generic_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v GenericParam<'v>) {
864 visitor.visit_id(param.hir_id);
866 ParamName::Plain(ident) => visitor.visit_ident(ident),
867 ParamName::Error | ParamName::Fresh(_) => {}
870 GenericParamKind::Lifetime { .. } => {}
871 GenericParamKind::Type { ref default, .. } => walk_list!(visitor, visit_ty, default),
872 GenericParamKind::Const { ref ty, ref default } => {
873 visitor.visit_ty(ty);
874 if let Some(ref default) = default {
875 visitor.visit_const_param_default(param.hir_id, default);
879 walk_list!(visitor, visit_param_bound, param.bounds);
882 pub fn walk_const_param_default<'v, V: Visitor<'v>>(visitor: &mut V, ct: &'v AnonConst) {
883 visitor.visit_anon_const(ct)
886 pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics<'v>) {
887 walk_list!(visitor, visit_generic_param, generics.params);
888 walk_list!(visitor, visit_where_predicate, generics.where_clause.predicates);
891 pub fn walk_where_predicate<'v, V: Visitor<'v>>(
893 predicate: &'v WherePredicate<'v>,
896 WherePredicate::BoundPredicate(WhereBoundPredicate {
899 bound_generic_params,
902 visitor.visit_ty(bounded_ty);
903 walk_list!(visitor, visit_param_bound, bounds);
904 walk_list!(visitor, visit_generic_param, bound_generic_params);
906 WherePredicate::RegionPredicate(WhereRegionPredicate { ref lifetime, bounds, .. }) => {
907 visitor.visit_lifetime(lifetime);
908 walk_list!(visitor, visit_param_bound, bounds);
910 WherePredicate::EqPredicate(WhereEqPredicate {
911 hir_id, ref lhs_ty, ref rhs_ty, ..
913 visitor.visit_id(hir_id);
914 visitor.visit_ty(lhs_ty);
915 visitor.visit_ty(rhs_ty);
920 pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FnRetTy<'v>) {
921 if let FnRetTy::Return(ref output_ty) = *ret_ty {
922 visitor.visit_ty(output_ty)
926 pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl<'v>) {
927 for ty in function_declaration.inputs {
930 walk_fn_ret_ty(visitor, &function_declaration.output)
933 pub fn walk_fn_kind<'v, V: Visitor<'v>>(visitor: &mut V, function_kind: FnKind<'v>) {
934 match function_kind {
935 FnKind::ItemFn(_, generics, ..) => {
936 visitor.visit_generics(generics);
938 FnKind::Method(..) | FnKind::Closure => {}
942 pub fn walk_fn<'v, V: Visitor<'v>>(
944 function_kind: FnKind<'v>,
945 function_declaration: &'v FnDecl<'v>,
950 visitor.visit_id(id);
951 visitor.visit_fn_decl(function_declaration);
952 walk_fn_kind(visitor, function_kind);
953 visitor.visit_nested_body(body_id)
956 pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem<'v>) {
957 visitor.visit_ident(trait_item.ident);
958 visitor.visit_generics(&trait_item.generics);
959 match trait_item.kind {
960 TraitItemKind::Const(ref ty, default) => {
961 visitor.visit_id(trait_item.hir_id());
962 visitor.visit_ty(ty);
963 walk_list!(visitor, visit_nested_body, default);
965 TraitItemKind::Fn(ref sig, TraitFn::Required(param_names)) => {
966 visitor.visit_id(trait_item.hir_id());
967 visitor.visit_fn_decl(&sig.decl);
968 for ¶m_name in param_names {
969 visitor.visit_ident(param_name);
972 TraitItemKind::Fn(ref sig, TraitFn::Provided(body_id)) => {
974 FnKind::Method(trait_item.ident, sig, None),
981 TraitItemKind::Type(bounds, ref default) => {
982 visitor.visit_id(trait_item.hir_id());
983 walk_list!(visitor, visit_param_bound, bounds);
984 walk_list!(visitor, visit_ty, default);
989 pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref: &'v TraitItemRef) {
990 // N.B., deliberately force a compilation error if/when new fields are added.
991 let TraitItemRef { id, ident, ref kind, span: _, ref defaultness } = *trait_item_ref;
992 visitor.visit_nested_trait_item(id);
993 visitor.visit_ident(ident);
994 visitor.visit_associated_item_kind(kind);
995 visitor.visit_defaultness(defaultness);
998 pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem<'v>) {
999 // N.B., deliberately force a compilation error if/when new fields are added.
1000 let ImplItem { def_id: _, ident, ref vis, ref defaultness, ref generics, ref kind, span: _ } =
1003 visitor.visit_ident(ident);
1004 visitor.visit_vis(vis);
1005 visitor.visit_defaultness(defaultness);
1006 visitor.visit_generics(generics);
1008 ImplItemKind::Const(ref ty, body) => {
1009 visitor.visit_id(impl_item.hir_id());
1010 visitor.visit_ty(ty);
1011 visitor.visit_nested_body(body);
1013 ImplItemKind::Fn(ref sig, body_id) => {
1015 FnKind::Method(impl_item.ident, sig, Some(&impl_item.vis)),
1022 ImplItemKind::TyAlias(ref ty) => {
1023 visitor.visit_id(impl_item.hir_id());
1024 visitor.visit_ty(ty);
1029 pub fn walk_foreign_item_ref<'v, V: Visitor<'v>>(
1031 foreign_item_ref: &'v ForeignItemRef<'v>,
1033 // N.B., deliberately force a compilation error if/when new fields are added.
1034 let ForeignItemRef { id, ident, span: _, ref vis } = *foreign_item_ref;
1035 visitor.visit_nested_foreign_item(id);
1036 visitor.visit_ident(ident);
1037 visitor.visit_vis(vis);
1040 pub fn walk_impl_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, impl_item_ref: &'v ImplItemRef<'v>) {
1041 // N.B., deliberately force a compilation error if/when new fields are added.
1042 let ImplItemRef { id, ident, ref kind, span: _, ref vis, ref defaultness } = *impl_item_ref;
1043 visitor.visit_nested_impl_item(id);
1044 visitor.visit_ident(ident);
1045 visitor.visit_associated_item_kind(kind);
1046 visitor.visit_vis(vis);
1047 visitor.visit_defaultness(defaultness);
1050 pub fn walk_struct_def<'v, V: Visitor<'v>>(
1052 struct_definition: &'v VariantData<'v>,
1054 walk_list!(visitor, visit_id, struct_definition.ctor_hir_id());
1055 walk_list!(visitor, visit_field_def, struct_definition.fields());
1058 pub fn walk_field_def<'v, V: Visitor<'v>>(visitor: &mut V, field: &'v FieldDef<'v>) {
1059 visitor.visit_id(field.hir_id);
1060 visitor.visit_vis(&field.vis);
1061 visitor.visit_ident(field.ident);
1062 visitor.visit_ty(&field.ty);
1065 pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block<'v>) {
1066 visitor.visit_id(block.hir_id);
1067 walk_list!(visitor, visit_stmt, block.stmts);
1068 walk_list!(visitor, visit_expr, &block.expr);
1071 pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt<'v>) {
1072 visitor.visit_id(statement.hir_id);
1073 match statement.kind {
1074 StmtKind::Local(ref local) => visitor.visit_local(local),
1075 StmtKind::Item(item) => visitor.visit_nested_item(item),
1076 StmtKind::Expr(ref expression) | StmtKind::Semi(ref expression) => {
1077 visitor.visit_expr(expression)
1082 pub fn walk_anon_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v AnonConst) {
1083 visitor.visit_id(constant.hir_id);
1084 visitor.visit_nested_body(constant.body);
1087 pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>) {
1088 visitor.visit_id(expression.hir_id);
1089 match expression.kind {
1090 ExprKind::Box(ref subexpression) => visitor.visit_expr(subexpression),
1091 ExprKind::Array(subexpressions) => {
1092 walk_list!(visitor, visit_expr, subexpressions);
1094 ExprKind::ConstBlock(ref anon_const) => visitor.visit_anon_const(anon_const),
1095 ExprKind::Repeat(ref element, ref count) => {
1096 visitor.visit_expr(element);
1097 visitor.visit_anon_const(count)
1099 ExprKind::Struct(ref qpath, fields, ref optional_base) => {
1100 visitor.visit_qpath(qpath, expression.hir_id, expression.span);
1101 for field in fields {
1102 visitor.visit_id(field.hir_id);
1103 visitor.visit_ident(field.ident);
1104 visitor.visit_expr(&field.expr)
1106 walk_list!(visitor, visit_expr, optional_base);
1108 ExprKind::Tup(subexpressions) => {
1109 walk_list!(visitor, visit_expr, subexpressions);
1111 ExprKind::Call(ref callee_expression, arguments) => {
1112 visitor.visit_expr(callee_expression);
1113 walk_list!(visitor, visit_expr, arguments);
1115 ExprKind::MethodCall(ref segment, _, arguments, _) => {
1116 visitor.visit_path_segment(expression.span, segment);
1117 walk_list!(visitor, visit_expr, arguments);
1119 ExprKind::Binary(_, ref left_expression, ref right_expression) => {
1120 visitor.visit_expr(left_expression);
1121 visitor.visit_expr(right_expression)
1123 ExprKind::AddrOf(_, _, ref subexpression) | ExprKind::Unary(_, ref subexpression) => {
1124 visitor.visit_expr(subexpression)
1126 ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => {
1127 visitor.visit_expr(subexpression);
1128 visitor.visit_ty(typ)
1130 ExprKind::DropTemps(ref subexpression) => {
1131 visitor.visit_expr(subexpression);
1133 ExprKind::If(ref cond, ref then, ref else_opt) => {
1134 visitor.visit_expr(cond);
1135 visitor.visit_expr(then);
1136 walk_list!(visitor, visit_expr, else_opt);
1138 ExprKind::Loop(ref block, ref opt_label, _, _) => {
1139 walk_list!(visitor, visit_label, opt_label);
1140 visitor.visit_block(block);
1142 ExprKind::Match(ref subexpression, arms, _) => {
1143 visitor.visit_expr(subexpression);
1144 walk_list!(visitor, visit_arm, arms);
1146 ExprKind::Closure(_, ref function_declaration, body, _fn_decl_span, _gen) => visitor
1149 function_declaration,
1154 ExprKind::Block(ref block, ref opt_label) => {
1155 walk_list!(visitor, visit_label, opt_label);
1156 visitor.visit_block(block);
1158 ExprKind::Assign(ref lhs, ref rhs, _) => {
1159 visitor.visit_expr(rhs);
1160 visitor.visit_expr(lhs)
1162 ExprKind::AssignOp(_, ref left_expression, ref right_expression) => {
1163 visitor.visit_expr(right_expression);
1164 visitor.visit_expr(left_expression);
1166 ExprKind::Field(ref subexpression, ident) => {
1167 visitor.visit_expr(subexpression);
1168 visitor.visit_ident(ident);
1170 ExprKind::Index(ref main_expression, ref index_expression) => {
1171 visitor.visit_expr(main_expression);
1172 visitor.visit_expr(index_expression)
1174 ExprKind::Path(ref qpath) => {
1175 visitor.visit_qpath(qpath, expression.hir_id, expression.span);
1177 ExprKind::Break(ref destination, ref opt_expr) => {
1178 walk_list!(visitor, visit_label, &destination.label);
1179 walk_list!(visitor, visit_expr, opt_expr);
1181 ExprKind::Continue(ref destination) => {
1182 walk_list!(visitor, visit_label, &destination.label);
1184 ExprKind::Ret(ref optional_expression) => {
1185 walk_list!(visitor, visit_expr, optional_expression);
1187 ExprKind::InlineAsm(ref asm) => {
1188 for (op, _op_sp) in asm.operands {
1190 InlineAsmOperand::In { expr, .. }
1191 | InlineAsmOperand::InOut { expr, .. }
1192 | InlineAsmOperand::Const { expr, .. }
1193 | InlineAsmOperand::Sym { expr, .. } => visitor.visit_expr(expr),
1194 InlineAsmOperand::Out { expr, .. } => {
1195 if let Some(expr) = expr {
1196 visitor.visit_expr(expr);
1199 InlineAsmOperand::SplitInOut { in_expr, out_expr, .. } => {
1200 visitor.visit_expr(in_expr);
1201 if let Some(out_expr) = out_expr {
1202 visitor.visit_expr(out_expr);
1208 ExprKind::LlvmInlineAsm(ref asm) => {
1209 walk_list!(visitor, visit_expr, asm.outputs_exprs);
1210 walk_list!(visitor, visit_expr, asm.inputs_exprs);
1212 ExprKind::Yield(ref subexpression, _) => {
1213 visitor.visit_expr(subexpression);
1215 ExprKind::Lit(_) | ExprKind::Err => {}
1219 pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm<'v>) {
1220 visitor.visit_id(arm.hir_id);
1221 visitor.visit_pat(&arm.pat);
1222 if let Some(ref g) = arm.guard {
1224 Guard::If(ref e) => visitor.visit_expr(e),
1225 Guard::IfLet(ref pat, ref e) => {
1226 visitor.visit_pat(pat);
1227 visitor.visit_expr(e);
1231 visitor.visit_expr(&arm.body);
1234 pub fn walk_vis<'v, V: Visitor<'v>>(visitor: &mut V, vis: &'v Visibility<'v>) {
1235 if let VisibilityKind::Restricted { ref path, hir_id } = vis.node {
1236 visitor.visit_id(hir_id);
1237 visitor.visit_path(path, hir_id)
1241 pub fn walk_associated_item_kind<'v, V: Visitor<'v>>(_: &mut V, _: &'v AssocItemKind) {
1242 // No visitable content here: this fn exists so you can call it if
1243 // the right thing to do, should content be added in the future,
1244 // would be to walk it.
1247 pub fn walk_defaultness<'v, V: Visitor<'v>>(_: &mut V, _: &'v Defaultness) {
1248 // No visitable content here: this fn exists so you can call it if
1249 // the right thing to do, should content be added in the future,
1250 // would be to walk it.