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};
38 use syntax::ast::{Attribute, Ident, Label, Name};
39 use syntax::walk_list;
41 pub struct DeepVisitor<'v, V> {
45 impl<'v, V> DeepVisitor<'v, V> {
46 pub fn new(base: &'v mut V) -> Self {
47 DeepVisitor { visitor: base }
51 impl<'v, 'hir, V> ItemLikeVisitor<'hir> for DeepVisitor<'v, V>
55 fn visit_item(&mut self, item: &'hir Item<'hir>) {
56 self.visitor.visit_item(item);
59 fn visit_trait_item(&mut self, trait_item: &'hir TraitItem<'hir>) {
60 self.visitor.visit_trait_item(trait_item);
63 fn visit_impl_item(&mut self, impl_item: &'hir ImplItem<'hir>) {
64 self.visitor.visit_impl_item(impl_item);
68 pub trait IntoVisitor<'hir> {
69 type Visitor: Visitor<'hir>;
70 fn into_visitor(&self) -> Self::Visitor;
73 pub struct ParDeepVisitor<V>(pub V);
75 impl<'hir, V> ParItemLikeVisitor<'hir> for ParDeepVisitor<V>
79 fn visit_item(&self, item: &'hir Item<'hir>) {
80 self.0.into_visitor().visit_item(item);
83 fn visit_trait_item(&self, trait_item: &'hir TraitItem<'hir>) {
84 self.0.into_visitor().visit_trait_item(trait_item);
87 fn visit_impl_item(&self, impl_item: &'hir ImplItem<'hir>) {
88 self.0.into_visitor().visit_impl_item(impl_item);
92 #[derive(Copy, Clone)]
94 /// `#[xxx] pub async/const/extern "Abi" fn foo()`
95 ItemFn(Ident, &'a Generics<'a>, FnHeader, &'a Visibility<'a>, &'a [Attribute]),
98 Method(Ident, &'a FnSig<'a>, Option<&'a Visibility<'a>>, &'a [Attribute]),
101 Closure(&'a [Attribute]),
104 impl<'a> FnKind<'a> {
105 pub fn attrs(&self) -> &'a [Attribute] {
107 FnKind::ItemFn(.., attrs) => attrs,
108 FnKind::Method(.., attrs) => attrs,
109 FnKind::Closure(attrs) => attrs,
113 pub fn header(&self) -> Option<&FnHeader> {
115 FnKind::ItemFn(_, _, ref header, _, _) => Some(header),
116 FnKind::Method(_, ref sig, _, _) => Some(&sig.header),
117 FnKind::Closure(_) => None,
122 /// An abstract representation of the HIR `rustc::hir::map::Map`.
123 pub trait Map<'hir> {
124 fn body(&self, id: BodyId) -> &'hir Body<'hir>;
125 fn item(&self, id: HirId) -> &'hir Item<'hir>;
126 fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir>;
127 fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem<'hir>;
130 /// Specifies what nested things a visitor wants to visit. The most
131 /// common choice is `OnlyBodies`, which will cause the visitor to
132 /// visit fn bodies for fns that it encounters, but skip over nested
133 /// item-like things.
135 /// See the comments on `ItemLikeVisitor` for more details on the overall
137 pub enum NestedVisitorMap<'this, M> {
138 /// Do not visit any nested things. When you add a new
139 /// "non-nested" thing, you will want to audit such uses to see if
140 /// they remain valid.
142 /// Use this if you are only walking some particular kind of tree
143 /// (i.e., a type, or fn signature) and you don't want to thread a
147 /// Do not visit nested item-like things, but visit nested things
148 /// that are inside of an item-like.
150 /// **This is the most common choice.** A very common pattern is
151 /// to use `visit_all_item_likes()` as an outer loop,
152 /// and to have the visitor that visits the contents of each item
153 /// using this setting.
154 OnlyBodies(&'this M),
156 /// Visits all nested things, including item-likes.
158 /// **This is an unusual choice.** It is used when you want to
159 /// process everything within their lexical context. Typically you
160 /// kick off the visit by doing `walk_krate()`.
164 impl<'this, M> NestedVisitorMap<'this, M> {
165 /// Returns the map to use for an "intra item-like" thing (if any).
166 /// E.g., function body.
167 fn intra(self) -> Option<&'this M> {
169 NestedVisitorMap::None => None,
170 NestedVisitorMap::OnlyBodies(map) => Some(map),
171 NestedVisitorMap::All(map) => Some(map),
175 /// Returns the map to use for an "item-like" thing (if any).
176 /// E.g., item, impl-item.
177 fn inter(self) -> Option<&'this M> {
179 NestedVisitorMap::None => None,
180 NestedVisitorMap::OnlyBodies(_) => None,
181 NestedVisitorMap::All(map) => Some(map),
186 /// Each method of the Visitor trait is a hook to be potentially
187 /// overridden. Each method's default implementation recursively visits
188 /// the substructure of the input via the corresponding `walk` method;
189 /// e.g., the `visit_mod` method by default calls `intravisit::walk_mod`.
191 /// Note that this visitor does NOT visit nested items by default
192 /// (this is why the module is called `intravisit`, to distinguish it
193 /// from the AST's `visit` module, which acts differently). If you
194 /// simply want to visit all items in the crate in some order, you
195 /// should call `Crate::visit_all_items`. Otherwise, see the comment
196 /// on `visit_nested_item` for details on how to visit nested items.
198 /// If you want to ensure that your code handles every variant
199 /// explicitly, you need to override each method. (And you also need
200 /// to monitor future changes to `Visitor` in case a new method with a
201 /// new default implementation gets introduced.)
202 pub trait Visitor<'v>: Sized {
205 ///////////////////////////////////////////////////////////////////////////
208 /// The default versions of the `visit_nested_XXX` routines invoke
209 /// this method to get a map to use. By selecting an enum variant,
210 /// you control which kinds of nested HIR are visited; see
211 /// `NestedVisitorMap` for details. By "nested HIR", we are
212 /// referring to bits of HIR that are not directly embedded within
213 /// one another but rather indirectly, through a table in the
214 /// crate. This is done to control dependencies during incremental
215 /// compilation: the non-inline bits of HIR can be tracked and
216 /// hashed separately.
218 /// **If for some reason you want the nested behavior, but don't
219 /// have a `Map` at your disposal:** then you should override the
220 /// `visit_nested_XXX` methods, and override this method to
221 /// `panic!()`. This way, if a new `visit_nested_XXX` variant is
222 /// added in the future, we will see the panic in your code and
223 /// fix it appropriately.
224 fn nested_visit_map(&mut self) -> NestedVisitorMap<'_, Self::Map>;
226 /// Invoked when a nested item is encountered. By default does
227 /// nothing unless you override `nested_visit_map` to return other than
228 /// `None`, in which case it will walk the item. **You probably
229 /// don't want to override this method** -- instead, override
230 /// `nested_visit_map` or use the "shallow" or "deep" visit
231 /// patterns described on `itemlikevisit::ItemLikeVisitor`. The only
232 /// reason to override this method is if you want a nested pattern
233 /// but cannot supply a `Map`; see `nested_visit_map` for advice.
234 #[allow(unused_variables)]
235 fn visit_nested_item(&mut self, id: ItemId) {
236 let opt_item = self.nested_visit_map().inter().map(|map| map.item(id.id));
237 walk_list!(self, visit_item, opt_item);
240 /// Like `visit_nested_item()`, but for trait items. See
241 /// `visit_nested_item()` for advice on when to override this
243 #[allow(unused_variables)]
244 fn visit_nested_trait_item(&mut self, id: TraitItemId) {
245 let opt_item = self.nested_visit_map().inter().map(|map| map.trait_item(id));
246 walk_list!(self, visit_trait_item, opt_item);
249 /// Like `visit_nested_item()`, but for impl items. See
250 /// `visit_nested_item()` for advice on when to override this
252 #[allow(unused_variables)]
253 fn visit_nested_impl_item(&mut self, id: ImplItemId) {
254 let opt_item = self.nested_visit_map().inter().map(|map| map.impl_item(id));
255 walk_list!(self, visit_impl_item, opt_item);
258 /// Invoked to visit the body of a function, method or closure. Like
259 /// visit_nested_item, does nothing by default unless you override
260 /// `nested_visit_map` to return other than `None`, in which case it will walk
262 fn visit_nested_body(&mut self, id: BodyId) {
263 let opt_body = self.nested_visit_map().intra().map(|map| map.body(id));
264 walk_list!(self, visit_body, opt_body);
267 fn visit_param(&mut self, param: &'v Param<'v>) {
268 walk_param(self, param)
271 /// Visits the top-level item and (optionally) nested items / impl items. See
272 /// `visit_nested_item` for details.
273 fn visit_item(&mut self, i: &'v Item<'v>) {
277 fn visit_body(&mut self, b: &'v Body<'v>) {
281 /// When invoking `visit_all_item_likes()`, you need to supply an
282 /// item-like visitor. This method converts a "intra-visit"
283 /// visitor into an item-like visitor that walks the entire tree.
284 /// If you use this, you probably don't want to process the
285 /// contents of nested item-like things, since the outer loop will
286 /// visit them as well.
287 fn as_deep_visitor<'s>(&'s mut self) -> DeepVisitor<'s, Self> {
288 DeepVisitor::new(self)
291 ///////////////////////////////////////////////////////////////////////////
293 fn visit_id(&mut self, _hir_id: HirId) {
296 fn visit_name(&mut self, _span: Span, _name: Name) {
299 fn visit_ident(&mut self, ident: Ident) {
300 walk_ident(self, ident)
302 fn visit_mod(&mut self, m: &'v Mod<'v>, _s: Span, n: HirId) {
305 fn visit_foreign_item(&mut self, i: &'v ForeignItem<'v>) {
306 walk_foreign_item(self, i)
308 fn visit_local(&mut self, l: &'v Local<'v>) {
311 fn visit_block(&mut self, b: &'v Block<'v>) {
314 fn visit_stmt(&mut self, s: &'v Stmt<'v>) {
317 fn visit_arm(&mut self, a: &'v Arm<'v>) {
320 fn visit_pat(&mut self, p: &'v Pat<'v>) {
323 fn visit_anon_const(&mut self, c: &'v AnonConst) {
324 walk_anon_const(self, c)
326 fn visit_expr(&mut self, ex: &'v Expr<'v>) {
329 fn visit_ty(&mut self, t: &'v Ty<'v>) {
332 fn visit_generic_param(&mut self, p: &'v GenericParam<'v>) {
333 walk_generic_param(self, p)
335 fn visit_generics(&mut self, g: &'v Generics<'v>) {
336 walk_generics(self, g)
338 fn visit_where_predicate(&mut self, predicate: &'v WherePredicate<'v>) {
339 walk_where_predicate(self, predicate)
341 fn visit_fn_decl(&mut self, fd: &'v FnDecl<'v>) {
342 walk_fn_decl(self, fd)
344 fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl<'v>, b: BodyId, s: Span, id: HirId) {
345 walk_fn(self, fk, fd, b, s, id)
347 fn visit_use(&mut self, path: &'v Path<'v>, hir_id: HirId) {
348 walk_use(self, path, hir_id)
350 fn visit_trait_item(&mut self, ti: &'v TraitItem<'v>) {
351 walk_trait_item(self, ti)
353 fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) {
354 walk_trait_item_ref(self, ii)
356 fn visit_impl_item(&mut self, ii: &'v ImplItem<'v>) {
357 walk_impl_item(self, ii)
359 fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef<'v>) {
360 walk_impl_item_ref(self, ii)
362 fn visit_trait_ref(&mut self, t: &'v TraitRef<'v>) {
363 walk_trait_ref(self, t)
365 fn visit_param_bound(&mut self, bounds: &'v GenericBound<'v>) {
366 walk_param_bound(self, bounds)
368 fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef<'v>, m: TraitBoundModifier) {
369 walk_poly_trait_ref(self, t, m)
371 fn visit_variant_data(
373 s: &'v VariantData<'v>,
379 walk_struct_def(self, s)
381 fn visit_struct_field(&mut self, s: &'v StructField<'v>) {
382 walk_struct_field(self, s)
386 enum_definition: &'v EnumDef<'v>,
387 generics: &'v Generics<'v>,
391 walk_enum_def(self, enum_definition, generics, item_id)
393 fn visit_variant(&mut self, v: &'v Variant<'v>, g: &'v Generics<'v>, item_id: HirId) {
394 walk_variant(self, v, g, item_id)
396 fn visit_label(&mut self, label: &'v Label) {
397 walk_label(self, label)
399 fn visit_generic_arg(&mut self, generic_arg: &'v GenericArg<'v>) {
401 GenericArg::Lifetime(lt) => self.visit_lifetime(lt),
402 GenericArg::Type(ty) => self.visit_ty(ty),
403 GenericArg::Const(ct) => self.visit_anon_const(&ct.value),
406 fn visit_lifetime(&mut self, lifetime: &'v Lifetime) {
407 walk_lifetime(self, lifetime)
409 fn visit_qpath(&mut self, qpath: &'v QPath<'v>, id: HirId, span: Span) {
410 walk_qpath(self, qpath, id, span)
412 fn visit_path(&mut self, path: &'v Path<'v>, _id: HirId) {
413 walk_path(self, path)
415 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment<'v>) {
416 walk_path_segment(self, path_span, path_segment)
418 fn visit_generic_args(&mut self, path_span: Span, generic_args: &'v GenericArgs<'v>) {
419 walk_generic_args(self, path_span, generic_args)
421 fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding<'v>) {
422 walk_assoc_type_binding(self, type_binding)
424 fn visit_attribute(&mut self, _attr: &'v Attribute) {}
425 fn visit_macro_def(&mut self, macro_def: &'v MacroDef<'v>) {
426 walk_macro_def(self, macro_def)
428 fn visit_vis(&mut self, vis: &'v Visibility<'v>) {
431 fn visit_associated_item_kind(&mut self, kind: &'v AssocItemKind) {
432 walk_associated_item_kind(self, kind);
434 fn visit_defaultness(&mut self, defaultness: &'v Defaultness) {
435 walk_defaultness(self, defaultness);
439 /// Walks the contents of a crate. See also `Crate::visit_all_items`.
440 pub fn walk_crate<'v, V: Visitor<'v>>(visitor: &mut V, krate: &'v Crate<'v>) {
441 visitor.visit_mod(&krate.module, krate.span, CRATE_HIR_ID);
442 walk_list!(visitor, visit_attribute, krate.attrs);
443 walk_list!(visitor, visit_macro_def, krate.exported_macros);
446 pub fn walk_macro_def<'v, V: Visitor<'v>>(visitor: &mut V, macro_def: &'v MacroDef<'v>) {
447 visitor.visit_id(macro_def.hir_id);
448 visitor.visit_name(macro_def.span, macro_def.name);
449 walk_list!(visitor, visit_attribute, macro_def.attrs);
452 pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod<'v>, mod_hir_id: HirId) {
453 visitor.visit_id(mod_hir_id);
454 for &item_id in module.item_ids {
455 visitor.visit_nested_item(item_id);
459 pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body<'v>) {
460 walk_list!(visitor, visit_param, body.params);
461 visitor.visit_expr(&body.value);
464 pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local<'v>) {
465 // Intentionally visiting the expr first - the initialization expr
466 // dominates the local's definition.
467 walk_list!(visitor, visit_expr, &local.init);
468 walk_list!(visitor, visit_attribute, local.attrs.iter());
469 visitor.visit_id(local.hir_id);
470 visitor.visit_pat(&local.pat);
471 walk_list!(visitor, visit_ty, &local.ty);
474 pub fn walk_ident<'v, V: Visitor<'v>>(visitor: &mut V, ident: Ident) {
475 visitor.visit_name(ident.span, ident.name);
478 pub fn walk_label<'v, V: Visitor<'v>>(visitor: &mut V, label: &'v Label) {
479 visitor.visit_ident(label.ident);
482 pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) {
483 visitor.visit_id(lifetime.hir_id);
484 match lifetime.name {
485 LifetimeName::Param(ParamName::Plain(ident)) => {
486 visitor.visit_ident(ident);
488 LifetimeName::Param(ParamName::Fresh(_))
489 | LifetimeName::Param(ParamName::Error)
490 | LifetimeName::Static
491 | LifetimeName::Error
492 | LifetimeName::Implicit
493 | LifetimeName::ImplicitObjectLifetimeDefault
494 | LifetimeName::Underscore => {}
498 pub fn walk_poly_trait_ref<'v, V: Visitor<'v>>(
500 trait_ref: &'v PolyTraitRef<'v>,
501 _modifier: TraitBoundModifier,
503 walk_list!(visitor, visit_generic_param, trait_ref.bound_generic_params);
504 visitor.visit_trait_ref(&trait_ref.trait_ref);
507 pub fn walk_trait_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_ref: &'v TraitRef<'v>) {
508 visitor.visit_id(trait_ref.hir_ref_id);
509 visitor.visit_path(&trait_ref.path, trait_ref.hir_ref_id)
512 pub fn walk_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v Param<'v>) {
513 visitor.visit_id(param.hir_id);
514 visitor.visit_pat(¶m.pat);
515 walk_list!(visitor, visit_attribute, param.attrs);
518 pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) {
519 visitor.visit_vis(&item.vis);
520 visitor.visit_ident(item.ident);
522 ItemKind::ExternCrate(orig_name) => {
523 visitor.visit_id(item.hir_id);
524 if let Some(orig_name) = orig_name {
525 visitor.visit_name(item.span, orig_name);
528 ItemKind::Use(ref path, _) => {
529 visitor.visit_use(path, item.hir_id);
531 ItemKind::Static(ref typ, _, body) | ItemKind::Const(ref typ, body) => {
532 visitor.visit_id(item.hir_id);
533 visitor.visit_ty(typ);
534 visitor.visit_nested_body(body);
536 ItemKind::Fn(ref sig, ref generics, body_id) => visitor.visit_fn(
537 FnKind::ItemFn(item.ident, generics, sig.header, &item.vis, &item.attrs),
543 ItemKind::Mod(ref module) => {
544 // `visit_mod()` takes care of visiting the `Item`'s `HirId`.
545 visitor.visit_mod(module, item.span, item.hir_id)
547 ItemKind::ForeignMod(ref foreign_module) => {
548 visitor.visit_id(item.hir_id);
549 walk_list!(visitor, visit_foreign_item, foreign_module.items);
551 ItemKind::GlobalAsm(_) => {
552 visitor.visit_id(item.hir_id);
554 ItemKind::TyAlias(ref ty, ref generics) => {
555 visitor.visit_id(item.hir_id);
556 visitor.visit_ty(ty);
557 visitor.visit_generics(generics)
559 ItemKind::OpaqueTy(OpaqueTy { ref generics, bounds, .. }) => {
560 visitor.visit_id(item.hir_id);
561 walk_generics(visitor, generics);
562 walk_list!(visitor, visit_param_bound, bounds);
564 ItemKind::Enum(ref enum_definition, ref generics) => {
565 visitor.visit_generics(generics);
566 // `visit_enum_def()` takes care of visiting the `Item`'s `HirId`.
567 visitor.visit_enum_def(enum_definition, generics, item.hir_id, item.span)
569 ItemKind::Impl(.., ref generics, ref opt_trait_reference, ref typ, impl_item_refs) => {
570 visitor.visit_id(item.hir_id);
571 visitor.visit_generics(generics);
572 walk_list!(visitor, visit_trait_ref, opt_trait_reference);
573 visitor.visit_ty(typ);
574 walk_list!(visitor, visit_impl_item_ref, impl_item_refs);
576 ItemKind::Struct(ref struct_definition, ref generics)
577 | ItemKind::Union(ref struct_definition, ref generics) => {
578 visitor.visit_generics(generics);
579 visitor.visit_id(item.hir_id);
580 visitor.visit_variant_data(
588 ItemKind::Trait(.., ref generics, bounds, trait_item_refs) => {
589 visitor.visit_id(item.hir_id);
590 visitor.visit_generics(generics);
591 walk_list!(visitor, visit_param_bound, bounds);
592 walk_list!(visitor, visit_trait_item_ref, trait_item_refs);
594 ItemKind::TraitAlias(ref generics, bounds) => {
595 visitor.visit_id(item.hir_id);
596 visitor.visit_generics(generics);
597 walk_list!(visitor, visit_param_bound, bounds);
600 walk_list!(visitor, visit_attribute, item.attrs);
603 pub fn walk_use<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>, hir_id: HirId) {
604 visitor.visit_id(hir_id);
605 visitor.visit_path(path, hir_id);
608 pub fn walk_enum_def<'v, V: Visitor<'v>>(
610 enum_definition: &'v EnumDef<'v>,
611 generics: &'v Generics<'v>,
614 visitor.visit_id(item_id);
615 walk_list!(visitor, visit_variant, enum_definition.variants, generics, item_id);
618 pub fn walk_variant<'v, V: Visitor<'v>>(
620 variant: &'v Variant<'v>,
621 generics: &'v Generics<'v>,
622 parent_item_id: HirId,
624 visitor.visit_ident(variant.ident);
625 visitor.visit_id(variant.id);
626 visitor.visit_variant_data(
633 walk_list!(visitor, visit_anon_const, &variant.disr_expr);
634 walk_list!(visitor, visit_attribute, variant.attrs);
637 pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty<'v>) {
638 visitor.visit_id(typ.hir_id);
641 TyKind::Slice(ref ty) => visitor.visit_ty(ty),
642 TyKind::Ptr(ref mutable_type) => visitor.visit_ty(&mutable_type.ty),
643 TyKind::Rptr(ref lifetime, ref mutable_type) => {
644 visitor.visit_lifetime(lifetime);
645 visitor.visit_ty(&mutable_type.ty)
648 TyKind::Tup(tuple_element_types) => {
649 walk_list!(visitor, visit_ty, tuple_element_types);
651 TyKind::BareFn(ref function_declaration) => {
652 walk_list!(visitor, visit_generic_param, function_declaration.generic_params);
653 visitor.visit_fn_decl(&function_declaration.decl);
655 TyKind::Path(ref qpath) => {
656 visitor.visit_qpath(qpath, typ.hir_id, typ.span);
658 TyKind::Def(item_id, lifetimes) => {
659 visitor.visit_nested_item(item_id);
660 walk_list!(visitor, visit_generic_arg, lifetimes);
662 TyKind::Array(ref ty, ref length) => {
663 visitor.visit_ty(ty);
664 visitor.visit_anon_const(length)
666 TyKind::TraitObject(bounds, ref lifetime) => {
667 for bound in bounds {
668 visitor.visit_poly_trait_ref(bound, TraitBoundModifier::None);
670 visitor.visit_lifetime(lifetime);
672 TyKind::Typeof(ref expression) => visitor.visit_anon_const(expression),
673 TyKind::Infer | TyKind::Err => {}
677 pub fn walk_qpath<'v, V: Visitor<'v>>(
679 qpath: &'v QPath<'v>,
684 QPath::Resolved(ref maybe_qself, ref path) => {
685 walk_list!(visitor, visit_ty, maybe_qself);
686 visitor.visit_path(path, id)
688 QPath::TypeRelative(ref qself, ref segment) => {
689 visitor.visit_ty(qself);
690 visitor.visit_path_segment(span, segment);
695 pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>) {
696 for segment in path.segments {
697 visitor.visit_path_segment(path.span, segment);
701 pub fn walk_path_segment<'v, V: Visitor<'v>>(
704 segment: &'v PathSegment<'v>,
706 visitor.visit_ident(segment.ident);
707 walk_list!(visitor, visit_id, segment.hir_id);
708 if let Some(ref args) = segment.args {
709 visitor.visit_generic_args(path_span, args);
713 pub fn walk_generic_args<'v, V: Visitor<'v>>(
716 generic_args: &'v GenericArgs<'v>,
718 walk_list!(visitor, visit_generic_arg, generic_args.args);
719 walk_list!(visitor, visit_assoc_type_binding, generic_args.bindings);
722 pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(
724 type_binding: &'v TypeBinding<'v>,
726 visitor.visit_id(type_binding.hir_id);
727 visitor.visit_ident(type_binding.ident);
728 match type_binding.kind {
729 TypeBindingKind::Equality { ref ty } => {
730 visitor.visit_ty(ty);
732 TypeBindingKind::Constraint { bounds } => {
733 walk_list!(visitor, visit_param_bound, bounds);
738 pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat<'v>) {
739 visitor.visit_id(pattern.hir_id);
741 PatKind::TupleStruct(ref qpath, children, _) => {
742 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
743 walk_list!(visitor, visit_pat, children);
745 PatKind::Path(ref qpath) => {
746 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
748 PatKind::Struct(ref qpath, fields, _) => {
749 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
750 for field in fields {
751 visitor.visit_id(field.hir_id);
752 visitor.visit_ident(field.ident);
753 visitor.visit_pat(&field.pat)
756 PatKind::Or(pats) => walk_list!(visitor, visit_pat, pats),
757 PatKind::Tuple(tuple_elements, _) => {
758 walk_list!(visitor, visit_pat, tuple_elements);
760 PatKind::Box(ref subpattern) | PatKind::Ref(ref subpattern, _) => {
761 visitor.visit_pat(subpattern)
763 PatKind::Binding(_, _hir_id, ident, ref optional_subpattern) => {
764 visitor.visit_ident(ident);
765 walk_list!(visitor, visit_pat, optional_subpattern);
767 PatKind::Lit(ref expression) => visitor.visit_expr(expression),
768 PatKind::Range(ref lower_bound, ref upper_bound, _) => {
769 walk_list!(visitor, visit_expr, lower_bound);
770 walk_list!(visitor, visit_expr, upper_bound);
773 PatKind::Slice(prepatterns, ref slice_pattern, postpatterns) => {
774 walk_list!(visitor, visit_pat, prepatterns);
775 walk_list!(visitor, visit_pat, slice_pattern);
776 walk_list!(visitor, visit_pat, postpatterns);
781 pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V, foreign_item: &'v ForeignItem<'v>) {
782 visitor.visit_id(foreign_item.hir_id);
783 visitor.visit_vis(&foreign_item.vis);
784 visitor.visit_ident(foreign_item.ident);
786 match foreign_item.kind {
787 ForeignItemKind::Fn(ref function_declaration, param_names, ref generics) => {
788 visitor.visit_generics(generics);
789 visitor.visit_fn_decl(function_declaration);
790 for ¶m_name in param_names {
791 visitor.visit_ident(param_name);
794 ForeignItemKind::Static(ref typ, _) => visitor.visit_ty(typ),
795 ForeignItemKind::Type => (),
798 walk_list!(visitor, visit_attribute, foreign_item.attrs);
801 pub fn walk_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v GenericBound<'v>) {
803 GenericBound::Trait(ref typ, modifier) => {
804 visitor.visit_poly_trait_ref(typ, modifier);
806 GenericBound::Outlives(ref lifetime) => visitor.visit_lifetime(lifetime),
810 pub fn walk_generic_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v GenericParam<'v>) {
811 visitor.visit_id(param.hir_id);
812 walk_list!(visitor, visit_attribute, param.attrs);
814 ParamName::Plain(ident) => visitor.visit_ident(ident),
815 ParamName::Error | ParamName::Fresh(_) => {}
818 GenericParamKind::Lifetime { .. } => {}
819 GenericParamKind::Type { ref default, .. } => walk_list!(visitor, visit_ty, default),
820 GenericParamKind::Const { ref ty } => visitor.visit_ty(ty),
822 walk_list!(visitor, visit_param_bound, param.bounds);
825 pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics<'v>) {
826 walk_list!(visitor, visit_generic_param, generics.params);
827 walk_list!(visitor, visit_where_predicate, generics.where_clause.predicates);
830 pub fn walk_where_predicate<'v, V: Visitor<'v>>(
832 predicate: &'v WherePredicate<'v>,
835 &WherePredicate::BoundPredicate(WhereBoundPredicate {
838 bound_generic_params,
841 visitor.visit_ty(bounded_ty);
842 walk_list!(visitor, visit_param_bound, bounds);
843 walk_list!(visitor, visit_generic_param, bound_generic_params);
845 &WherePredicate::RegionPredicate(WhereRegionPredicate { ref lifetime, bounds, .. }) => {
846 visitor.visit_lifetime(lifetime);
847 walk_list!(visitor, visit_param_bound, bounds);
849 &WherePredicate::EqPredicate(WhereEqPredicate {
850 hir_id, ref lhs_ty, ref rhs_ty, ..
852 visitor.visit_id(hir_id);
853 visitor.visit_ty(lhs_ty);
854 visitor.visit_ty(rhs_ty);
859 pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FunctionRetTy<'v>) {
860 if let FunctionRetTy::Return(ref output_ty) = *ret_ty {
861 visitor.visit_ty(output_ty)
865 pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl<'v>) {
866 for ty in function_declaration.inputs {
869 walk_fn_ret_ty(visitor, &function_declaration.output)
872 pub fn walk_fn_kind<'v, V: Visitor<'v>>(visitor: &mut V, function_kind: FnKind<'v>) {
873 match function_kind {
874 FnKind::ItemFn(_, generics, ..) => {
875 visitor.visit_generics(generics);
877 FnKind::Method(..) | FnKind::Closure(_) => {}
881 pub fn walk_fn<'v, V: Visitor<'v>>(
883 function_kind: FnKind<'v>,
884 function_declaration: &'v FnDecl<'v>,
889 visitor.visit_id(id);
890 visitor.visit_fn_decl(function_declaration);
891 walk_fn_kind(visitor, function_kind);
892 visitor.visit_nested_body(body_id)
895 pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem<'v>) {
896 visitor.visit_ident(trait_item.ident);
897 walk_list!(visitor, visit_attribute, trait_item.attrs);
898 visitor.visit_generics(&trait_item.generics);
899 match trait_item.kind {
900 TraitItemKind::Const(ref ty, default) => {
901 visitor.visit_id(trait_item.hir_id);
902 visitor.visit_ty(ty);
903 walk_list!(visitor, visit_nested_body, default);
905 TraitItemKind::Method(ref sig, TraitMethod::Required(param_names)) => {
906 visitor.visit_id(trait_item.hir_id);
907 visitor.visit_fn_decl(&sig.decl);
908 for ¶m_name in param_names {
909 visitor.visit_ident(param_name);
912 TraitItemKind::Method(ref sig, TraitMethod::Provided(body_id)) => {
914 FnKind::Method(trait_item.ident, sig, None, &trait_item.attrs),
921 TraitItemKind::Type(bounds, ref default) => {
922 visitor.visit_id(trait_item.hir_id);
923 walk_list!(visitor, visit_param_bound, bounds);
924 walk_list!(visitor, visit_ty, default);
929 pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref: &'v TraitItemRef) {
930 // N.B., deliberately force a compilation error if/when new fields are added.
931 let TraitItemRef { id, ident, ref kind, span: _, ref defaultness } = *trait_item_ref;
932 visitor.visit_nested_trait_item(id);
933 visitor.visit_ident(ident);
934 visitor.visit_associated_item_kind(kind);
935 visitor.visit_defaultness(defaultness);
938 pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem<'v>) {
939 // N.B., deliberately force a compilation error if/when new fields are added.
951 visitor.visit_ident(ident);
952 visitor.visit_vis(vis);
953 visitor.visit_defaultness(defaultness);
954 walk_list!(visitor, visit_attribute, attrs);
955 visitor.visit_generics(generics);
957 ImplItemKind::Const(ref ty, body) => {
958 visitor.visit_id(impl_item.hir_id);
959 visitor.visit_ty(ty);
960 visitor.visit_nested_body(body);
962 ImplItemKind::Method(ref sig, body_id) => {
964 FnKind::Method(impl_item.ident, sig, Some(&impl_item.vis), &impl_item.attrs),
971 ImplItemKind::TyAlias(ref ty) => {
972 visitor.visit_id(impl_item.hir_id);
973 visitor.visit_ty(ty);
975 ImplItemKind::OpaqueTy(bounds) => {
976 visitor.visit_id(impl_item.hir_id);
977 walk_list!(visitor, visit_param_bound, bounds);
982 pub fn walk_impl_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, impl_item_ref: &'v ImplItemRef<'v>) {
983 // N.B., deliberately force a compilation error if/when new fields are added.
984 let ImplItemRef { id, ident, ref kind, span: _, ref vis, ref defaultness } = *impl_item_ref;
985 visitor.visit_nested_impl_item(id);
986 visitor.visit_ident(ident);
987 visitor.visit_associated_item_kind(kind);
988 visitor.visit_vis(vis);
989 visitor.visit_defaultness(defaultness);
992 pub fn walk_struct_def<'v, V: Visitor<'v>>(
994 struct_definition: &'v VariantData<'v>,
996 walk_list!(visitor, visit_id, struct_definition.ctor_hir_id());
997 walk_list!(visitor, visit_struct_field, struct_definition.fields());
1000 pub fn walk_struct_field<'v, V: Visitor<'v>>(visitor: &mut V, struct_field: &'v StructField<'v>) {
1001 visitor.visit_id(struct_field.hir_id);
1002 visitor.visit_vis(&struct_field.vis);
1003 visitor.visit_ident(struct_field.ident);
1004 visitor.visit_ty(&struct_field.ty);
1005 walk_list!(visitor, visit_attribute, struct_field.attrs);
1008 pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block<'v>) {
1009 visitor.visit_id(block.hir_id);
1010 walk_list!(visitor, visit_stmt, block.stmts);
1011 walk_list!(visitor, visit_expr, &block.expr);
1014 pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt<'v>) {
1015 visitor.visit_id(statement.hir_id);
1016 match statement.kind {
1017 StmtKind::Local(ref local) => visitor.visit_local(local),
1018 StmtKind::Item(item) => visitor.visit_nested_item(item),
1019 StmtKind::Expr(ref expression) | StmtKind::Semi(ref expression) => {
1020 visitor.visit_expr(expression)
1025 pub fn walk_anon_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v AnonConst) {
1026 visitor.visit_id(constant.hir_id);
1027 visitor.visit_nested_body(constant.body);
1030 pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>) {
1031 visitor.visit_id(expression.hir_id);
1032 walk_list!(visitor, visit_attribute, expression.attrs.iter());
1033 match expression.kind {
1034 ExprKind::Box(ref subexpression) => visitor.visit_expr(subexpression),
1035 ExprKind::Array(subexpressions) => {
1036 walk_list!(visitor, visit_expr, subexpressions);
1038 ExprKind::Repeat(ref element, ref count) => {
1039 visitor.visit_expr(element);
1040 visitor.visit_anon_const(count)
1042 ExprKind::Struct(ref qpath, fields, ref optional_base) => {
1043 visitor.visit_qpath(qpath, expression.hir_id, expression.span);
1044 for field in fields {
1045 visitor.visit_id(field.hir_id);
1046 visitor.visit_ident(field.ident);
1047 visitor.visit_expr(&field.expr)
1049 walk_list!(visitor, visit_expr, optional_base);
1051 ExprKind::Tup(subexpressions) => {
1052 walk_list!(visitor, visit_expr, subexpressions);
1054 ExprKind::Call(ref callee_expression, arguments) => {
1055 visitor.visit_expr(callee_expression);
1056 walk_list!(visitor, visit_expr, arguments);
1058 ExprKind::MethodCall(ref segment, _, arguments) => {
1059 visitor.visit_path_segment(expression.span, segment);
1060 walk_list!(visitor, visit_expr, arguments);
1062 ExprKind::Binary(_, ref left_expression, ref right_expression) => {
1063 visitor.visit_expr(left_expression);
1064 visitor.visit_expr(right_expression)
1066 ExprKind::AddrOf(_, _, ref subexpression) | ExprKind::Unary(_, ref subexpression) => {
1067 visitor.visit_expr(subexpression)
1069 ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => {
1070 visitor.visit_expr(subexpression);
1071 visitor.visit_ty(typ)
1073 ExprKind::DropTemps(ref subexpression) => {
1074 visitor.visit_expr(subexpression);
1076 ExprKind::Loop(ref block, ref opt_label, _) => {
1077 walk_list!(visitor, visit_label, opt_label);
1078 visitor.visit_block(block);
1080 ExprKind::Match(ref subexpression, arms, _) => {
1081 visitor.visit_expr(subexpression);
1082 walk_list!(visitor, visit_arm, arms);
1084 ExprKind::Closure(_, ref function_declaration, body, _fn_decl_span, _gen) => visitor
1086 FnKind::Closure(&expression.attrs),
1087 function_declaration,
1092 ExprKind::Block(ref block, ref opt_label) => {
1093 walk_list!(visitor, visit_label, opt_label);
1094 visitor.visit_block(block);
1096 ExprKind::Assign(ref lhs, ref rhs, _) => {
1097 visitor.visit_expr(rhs);
1098 visitor.visit_expr(lhs)
1100 ExprKind::AssignOp(_, ref left_expression, ref right_expression) => {
1101 visitor.visit_expr(right_expression);
1102 visitor.visit_expr(left_expression);
1104 ExprKind::Field(ref subexpression, ident) => {
1105 visitor.visit_expr(subexpression);
1106 visitor.visit_ident(ident);
1108 ExprKind::Index(ref main_expression, ref index_expression) => {
1109 visitor.visit_expr(main_expression);
1110 visitor.visit_expr(index_expression)
1112 ExprKind::Path(ref qpath) => {
1113 visitor.visit_qpath(qpath, expression.hir_id, expression.span);
1115 ExprKind::Break(ref destination, ref opt_expr) => {
1116 walk_list!(visitor, visit_label, &destination.label);
1117 walk_list!(visitor, visit_expr, opt_expr);
1119 ExprKind::Continue(ref destination) => {
1120 walk_list!(visitor, visit_label, &destination.label);
1122 ExprKind::Ret(ref optional_expression) => {
1123 walk_list!(visitor, visit_expr, optional_expression);
1125 ExprKind::InlineAsm(ref asm) => {
1126 walk_list!(visitor, visit_expr, asm.outputs_exprs);
1127 walk_list!(visitor, visit_expr, asm.inputs_exprs);
1129 ExprKind::Yield(ref subexpression, _) => {
1130 visitor.visit_expr(subexpression);
1132 ExprKind::Lit(_) | ExprKind::Err => {}
1136 pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm<'v>) {
1137 visitor.visit_id(arm.hir_id);
1138 visitor.visit_pat(&arm.pat);
1139 if let Some(ref g) = arm.guard {
1141 Guard::If(ref e) => visitor.visit_expr(e),
1144 visitor.visit_expr(&arm.body);
1145 walk_list!(visitor, visit_attribute, arm.attrs);
1148 pub fn walk_vis<'v, V: Visitor<'v>>(visitor: &mut V, vis: &'v Visibility<'v>) {
1149 if let VisibilityKind::Restricted { ref path, hir_id } = vis.node {
1150 visitor.visit_id(hir_id);
1151 visitor.visit_path(path, hir_id)
1155 pub fn walk_associated_item_kind<'v, V: Visitor<'v>>(_: &mut V, _: &'v AssocItemKind) {
1156 // No visitable content here: this fn exists so you can call it if
1157 // the right thing to do, should content be added in the future,
1158 // would be to walk it.
1161 pub fn walk_defaultness<'v, V: Visitor<'v>>(_: &mut V, _: &'v Defaultness) {
1162 // No visitable content here: this fn exists so you can call it if
1163 // the right thing to do, should content be added in the future,
1164 // would be to walk it.