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::itemlikevisit::{ItemLikeVisitor, ParItemLikeVisitor};
36 use rustc_ast::walk_list;
37 use rustc_ast::{Attribute, Label};
38 use rustc_span::symbol::{Ident, Symbol};
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);
67 fn visit_foreign_item(&mut self, foreign_item: &'hir ForeignItem<'hir>) {
68 self.visitor.visit_foreign_item(foreign_item);
72 pub trait IntoVisitor<'hir> {
73 type Visitor: Visitor<'hir>;
74 fn into_visitor(&self) -> Self::Visitor;
77 pub struct ParDeepVisitor<V>(pub V);
79 impl<'hir, V> ParItemLikeVisitor<'hir> for ParDeepVisitor<V>
83 fn visit_item(&self, item: &'hir Item<'hir>) {
84 self.0.into_visitor().visit_item(item);
87 fn visit_trait_item(&self, trait_item: &'hir TraitItem<'hir>) {
88 self.0.into_visitor().visit_trait_item(trait_item);
91 fn visit_impl_item(&self, impl_item: &'hir ImplItem<'hir>) {
92 self.0.into_visitor().visit_impl_item(impl_item);
95 fn visit_foreign_item(&self, foreign_item: &'hir ForeignItem<'hir>) {
96 self.0.into_visitor().visit_foreign_item(foreign_item);
100 #[derive(Copy, Clone, Debug)]
101 pub enum FnKind<'a> {
102 /// `#[xxx] pub async/const/extern "Abi" fn foo()`
103 ItemFn(Ident, &'a Generics<'a>, FnHeader, &'a Visibility<'a>),
106 Method(Ident, &'a FnSig<'a>, Option<&'a Visibility<'a>>),
112 impl<'a> FnKind<'a> {
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_middle::hir::map::Map`.
123 pub trait Map<'hir> {
124 /// Retrieves the `Node` corresponding to `id`, returning `None` if cannot be found.
125 fn find(&self, hir_id: HirId) -> Option<Node<'hir>>;
126 fn body(&self, id: BodyId) -> &'hir Body<'hir>;
127 fn item(&self, id: ItemId) -> &'hir Item<'hir>;
128 fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir>;
129 fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem<'hir>;
130 fn foreign_item(&self, id: ForeignItemId) -> &'hir ForeignItem<'hir>;
133 /// An erased version of `Map<'hir>`, using dynamic dispatch.
134 /// NOTE: This type is effectively only usable with `NestedVisitorMap::None`.
135 pub struct ErasedMap<'hir>(&'hir dyn Map<'hir>);
137 impl<'hir> Map<'hir> for ErasedMap<'hir> {
138 fn find(&self, _: HirId) -> Option<Node<'hir>> {
141 fn body(&self, id: BodyId) -> &'hir Body<'hir> {
144 fn item(&self, id: ItemId) -> &'hir Item<'hir> {
147 fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir> {
148 self.0.trait_item(id)
150 fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem<'hir> {
153 fn foreign_item(&self, id: ForeignItemId) -> &'hir ForeignItem<'hir> {
154 self.0.foreign_item(id)
158 /// Specifies what nested things a visitor wants to visit. The most
159 /// common choice is `OnlyBodies`, which will cause the visitor to
160 /// visit fn bodies for fns that it encounters, but skip over nested
161 /// item-like things.
163 /// See the comments on `ItemLikeVisitor` for more details on the overall
165 pub enum NestedVisitorMap<M> {
166 /// Do not visit any nested things. When you add a new
167 /// "non-nested" thing, you will want to audit such uses to see if
168 /// they remain valid.
170 /// Use this if you are only walking some particular kind of tree
171 /// (i.e., a type, or fn signature) and you don't want to thread a
175 /// Do not visit nested item-like things, but visit nested things
176 /// that are inside of an item-like.
178 /// **This is the most common choice.** A very common pattern is
179 /// to use `visit_all_item_likes()` as an outer loop,
180 /// and to have the visitor that visits the contents of each item
181 /// using this setting.
184 /// Visits all nested things, including item-likes.
186 /// **This is an unusual choice.** It is used when you want to
187 /// process everything within their lexical context. Typically you
188 /// kick off the visit by doing `walk_krate()`.
192 impl<M> NestedVisitorMap<M> {
193 /// Returns the map to use for an "intra item-like" thing (if any).
194 /// E.g., function body.
195 fn intra(self) -> Option<M> {
197 NestedVisitorMap::None => None,
198 NestedVisitorMap::OnlyBodies(map) => Some(map),
199 NestedVisitorMap::All(map) => Some(map),
203 /// Returns the map to use for an "item-like" thing (if any).
204 /// E.g., item, impl-item.
205 fn inter(self) -> Option<M> {
207 NestedVisitorMap::None => None,
208 NestedVisitorMap::OnlyBodies(_) => None,
209 NestedVisitorMap::All(map) => Some(map),
214 /// Each method of the Visitor trait is a hook to be potentially
215 /// overridden. Each method's default implementation recursively visits
216 /// the substructure of the input via the corresponding `walk` method;
217 /// e.g., the `visit_mod` method by default calls `intravisit::walk_mod`.
219 /// Note that this visitor does NOT visit nested items by default
220 /// (this is why the module is called `intravisit`, to distinguish it
221 /// from the AST's `visit` module, which acts differently). If you
222 /// simply want to visit all items in the crate in some order, you
223 /// should call `Crate::visit_all_items`. Otherwise, see the comment
224 /// on `visit_nested_item` for details on how to visit nested items.
226 /// If you want to ensure that your code handles every variant
227 /// explicitly, you need to override each method. (And you also need
228 /// to monitor future changes to `Visitor` in case a new method with a
229 /// new default implementation gets introduced.)
230 pub trait Visitor<'v>: Sized {
233 ///////////////////////////////////////////////////////////////////////////
236 /// The default versions of the `visit_nested_XXX` routines invoke
237 /// this method to get a map to use. By selecting an enum variant,
238 /// you control which kinds of nested HIR are visited; see
239 /// `NestedVisitorMap` for details. By "nested HIR", we are
240 /// referring to bits of HIR that are not directly embedded within
241 /// one another but rather indirectly, through a table in the
242 /// crate. This is done to control dependencies during incremental
243 /// compilation: the non-inline bits of HIR can be tracked and
244 /// hashed separately.
246 /// **If for some reason you want the nested behavior, but don't
247 /// have a `Map` at your disposal:** then you should override the
248 /// `visit_nested_XXX` methods, and override this method to
249 /// `panic!()`. This way, if a new `visit_nested_XXX` variant is
250 /// added in the future, we will see the panic in your code and
251 /// fix it appropriately.
252 fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map>;
254 /// Invoked when a nested item is encountered. By default does
255 /// nothing unless you override `nested_visit_map` to return other than
256 /// `None`, in which case it will walk the item. **You probably
257 /// don't want to override this method** -- instead, override
258 /// `nested_visit_map` or use the "shallow" or "deep" visit
259 /// patterns described on `itemlikevisit::ItemLikeVisitor`. The only
260 /// reason to override this method is if you want a nested pattern
261 /// but cannot supply a `Map`; see `nested_visit_map` for advice.
262 fn visit_nested_item(&mut self, id: ItemId) {
263 let opt_item = self.nested_visit_map().inter().map(|map| map.item(id));
264 walk_list!(self, visit_item, opt_item);
267 /// Like `visit_nested_item()`, but for trait items. See
268 /// `visit_nested_item()` for advice on when to override this
270 fn visit_nested_trait_item(&mut self, id: TraitItemId) {
271 let opt_item = self.nested_visit_map().inter().map(|map| map.trait_item(id));
272 walk_list!(self, visit_trait_item, opt_item);
275 /// Like `visit_nested_item()`, but for impl items. See
276 /// `visit_nested_item()` for advice on when to override this
278 fn visit_nested_impl_item(&mut self, id: ImplItemId) {
279 let opt_item = self.nested_visit_map().inter().map(|map| map.impl_item(id));
280 walk_list!(self, visit_impl_item, opt_item);
283 /// Like `visit_nested_item()`, but for foreign items. See
284 /// `visit_nested_item()` for advice on when to override this
286 fn visit_nested_foreign_item(&mut self, id: ForeignItemId) {
287 let opt_item = self.nested_visit_map().inter().map(|map| map.foreign_item(id));
288 walk_list!(self, visit_foreign_item, opt_item);
291 /// Invoked to visit the body of a function, method or closure. Like
292 /// visit_nested_item, does nothing by default unless you override
293 /// `nested_visit_map` to return other than `None`, in which case it will walk
295 fn visit_nested_body(&mut self, id: BodyId) {
296 let opt_body = self.nested_visit_map().intra().map(|map| map.body(id));
297 walk_list!(self, visit_body, opt_body);
300 fn visit_param(&mut self, param: &'v Param<'v>) {
301 walk_param(self, param)
304 /// Visits the top-level item and (optionally) nested items / impl items. See
305 /// `visit_nested_item` for details.
306 fn visit_item(&mut self, i: &'v Item<'v>) {
310 fn visit_body(&mut self, b: &'v Body<'v>) {
314 /// When invoking `visit_all_item_likes()`, you need to supply an
315 /// item-like visitor. This method converts an "intra-visit"
316 /// visitor into an item-like visitor that walks the entire tree.
317 /// If you use this, you probably don't want to process the
318 /// contents of nested item-like things, since the outer loop will
319 /// visit them as well.
320 fn as_deep_visitor(&mut self) -> DeepVisitor<'_, Self> {
321 DeepVisitor::new(self)
324 ///////////////////////////////////////////////////////////////////////////
326 fn visit_id(&mut self, _hir_id: HirId) {
329 fn visit_name(&mut self, _span: Span, _name: Symbol) {
332 fn visit_ident(&mut self, ident: Ident) {
333 walk_ident(self, ident)
335 fn visit_mod(&mut self, m: &'v Mod<'v>, _s: Span, n: HirId) {
338 fn visit_foreign_item(&mut self, i: &'v ForeignItem<'v>) {
339 walk_foreign_item(self, i)
341 fn visit_local(&mut self, l: &'v Local<'v>) {
344 fn visit_block(&mut self, b: &'v Block<'v>) {
347 fn visit_stmt(&mut self, s: &'v Stmt<'v>) {
350 fn visit_arm(&mut self, a: &'v Arm<'v>) {
353 fn visit_pat(&mut self, p: &'v Pat<'v>) {
356 fn visit_anon_const(&mut self, c: &'v AnonConst) {
357 walk_anon_const(self, c)
359 fn visit_expr(&mut self, ex: &'v Expr<'v>) {
362 fn visit_ty(&mut self, t: &'v Ty<'v>) {
365 fn visit_generic_param(&mut self, p: &'v GenericParam<'v>) {
366 walk_generic_param(self, p)
368 fn visit_const_param_default(&mut self, _param: HirId, ct: &'v AnonConst) {
369 walk_const_param_default(self, ct)
371 fn visit_generics(&mut self, g: &'v Generics<'v>) {
372 walk_generics(self, g)
374 fn visit_where_predicate(&mut self, predicate: &'v WherePredicate<'v>) {
375 walk_where_predicate(self, predicate)
377 fn visit_fn_decl(&mut self, fd: &'v FnDecl<'v>) {
378 walk_fn_decl(self, fd)
380 fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl<'v>, b: BodyId, s: Span, id: HirId) {
381 walk_fn(self, fk, fd, b, s, id)
383 fn visit_use(&mut self, path: &'v Path<'v>, hir_id: HirId) {
384 walk_use(self, path, hir_id)
386 fn visit_trait_item(&mut self, ti: &'v TraitItem<'v>) {
387 walk_trait_item(self, ti)
389 fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) {
390 walk_trait_item_ref(self, ii)
392 fn visit_impl_item(&mut self, ii: &'v ImplItem<'v>) {
393 walk_impl_item(self, ii)
395 fn visit_foreign_item_ref(&mut self, ii: &'v ForeignItemRef) {
396 walk_foreign_item_ref(self, ii)
398 fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef) {
399 walk_impl_item_ref(self, ii)
401 fn visit_trait_ref(&mut self, t: &'v TraitRef<'v>) {
402 walk_trait_ref(self, t)
404 fn visit_param_bound(&mut self, bounds: &'v GenericBound<'v>) {
405 walk_param_bound(self, bounds)
407 fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef<'v>, m: TraitBoundModifier) {
408 walk_poly_trait_ref(self, t, m)
410 fn visit_variant_data(
412 s: &'v VariantData<'v>,
418 walk_struct_def(self, s)
420 fn visit_field_def(&mut self, s: &'v FieldDef<'v>) {
421 walk_field_def(self, s)
425 enum_definition: &'v EnumDef<'v>,
426 generics: &'v Generics<'v>,
430 walk_enum_def(self, enum_definition, generics, item_id)
432 fn visit_variant(&mut self, v: &'v Variant<'v>, g: &'v Generics<'v>, item_id: HirId) {
433 walk_variant(self, v, g, item_id)
435 fn visit_label(&mut self, label: &'v Label) {
436 walk_label(self, label)
438 fn visit_infer(&mut self, inf: &'v InferArg) {
441 fn visit_generic_arg(&mut self, generic_arg: &'v GenericArg<'v>) {
443 GenericArg::Lifetime(lt) => self.visit_lifetime(lt),
444 GenericArg::Type(ty) => self.visit_ty(ty),
445 GenericArg::Const(ct) => self.visit_anon_const(&ct.value),
446 GenericArg::Infer(inf) => self.visit_infer(inf),
449 fn visit_lifetime(&mut self, lifetime: &'v Lifetime) {
450 walk_lifetime(self, lifetime)
452 fn visit_qpath(&mut self, qpath: &'v QPath<'v>, id: HirId, span: Span) {
453 walk_qpath(self, qpath, id, span)
455 fn visit_path(&mut self, path: &'v Path<'v>, _id: HirId) {
456 walk_path(self, path)
458 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment<'v>) {
459 walk_path_segment(self, path_span, path_segment)
461 fn visit_generic_args(&mut self, path_span: Span, generic_args: &'v GenericArgs<'v>) {
462 walk_generic_args(self, path_span, generic_args)
464 fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding<'v>) {
465 walk_assoc_type_binding(self, type_binding)
467 fn visit_attribute(&mut self, _id: HirId, _attr: &'v Attribute) {}
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 pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod<'v>, mod_hir_id: HirId) {
480 visitor.visit_id(mod_hir_id);
481 for &item_id in module.item_ids {
482 visitor.visit_nested_item(item_id);
486 pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body<'v>) {
487 walk_list!(visitor, visit_param, body.params);
488 visitor.visit_expr(&body.value);
491 pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local<'v>) {
492 // Intentionally visiting the expr first - the initialization expr
493 // dominates the local's definition.
494 walk_list!(visitor, visit_expr, &local.init);
495 visitor.visit_id(local.hir_id);
496 visitor.visit_pat(&local.pat);
497 walk_list!(visitor, visit_ty, &local.ty);
500 pub fn walk_ident<'v, V: Visitor<'v>>(visitor: &mut V, ident: Ident) {
501 visitor.visit_name(ident.span, ident.name);
504 pub fn walk_label<'v, V: Visitor<'v>>(visitor: &mut V, label: &'v Label) {
505 visitor.visit_ident(label.ident);
508 pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) {
509 visitor.visit_id(lifetime.hir_id);
510 match lifetime.name {
511 LifetimeName::Param(ParamName::Plain(ident)) => {
512 visitor.visit_ident(ident);
514 LifetimeName::Param(ParamName::Fresh(_))
515 | LifetimeName::Param(ParamName::Error)
516 | LifetimeName::Static
517 | LifetimeName::Error
518 | LifetimeName::Implicit
519 | LifetimeName::ImplicitObjectLifetimeDefault
520 | LifetimeName::Underscore => {}
524 pub fn walk_poly_trait_ref<'v, V: Visitor<'v>>(
526 trait_ref: &'v PolyTraitRef<'v>,
527 _modifier: TraitBoundModifier,
529 walk_list!(visitor, visit_generic_param, trait_ref.bound_generic_params);
530 visitor.visit_trait_ref(&trait_ref.trait_ref);
533 pub fn walk_trait_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_ref: &'v TraitRef<'v>) {
534 visitor.visit_id(trait_ref.hir_ref_id);
535 visitor.visit_path(&trait_ref.path, trait_ref.hir_ref_id)
538 pub fn walk_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v Param<'v>) {
539 visitor.visit_id(param.hir_id);
540 visitor.visit_pat(¶m.pat);
543 pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) {
544 visitor.visit_vis(&item.vis);
545 visitor.visit_ident(item.ident);
547 ItemKind::ExternCrate(orig_name) => {
548 visitor.visit_id(item.hir_id());
549 if let Some(orig_name) = orig_name {
550 visitor.visit_name(item.span, orig_name);
553 ItemKind::Use(ref path, _) => {
554 visitor.visit_use(path, item.hir_id());
556 ItemKind::Static(ref typ, _, body) | ItemKind::Const(ref typ, body) => {
557 visitor.visit_id(item.hir_id());
558 visitor.visit_ty(typ);
559 visitor.visit_nested_body(body);
561 ItemKind::Fn(ref sig, ref generics, body_id) => visitor.visit_fn(
562 FnKind::ItemFn(item.ident, generics, sig.header, &item.vis),
568 ItemKind::Macro(_) => {
569 visitor.visit_id(item.hir_id());
571 ItemKind::Mod(ref module) => {
572 // `visit_mod()` takes care of visiting the `Item`'s `HirId`.
573 visitor.visit_mod(module, item.span, item.hir_id())
575 ItemKind::ForeignMod { abi: _, items } => {
576 visitor.visit_id(item.hir_id());
577 walk_list!(visitor, visit_foreign_item_ref, items);
579 ItemKind::GlobalAsm(asm) => {
580 visitor.visit_id(item.hir_id());
581 walk_inline_asm(visitor, asm);
583 ItemKind::TyAlias(ref ty, ref generics) => {
584 visitor.visit_id(item.hir_id());
585 visitor.visit_ty(ty);
586 visitor.visit_generics(generics)
588 ItemKind::OpaqueTy(OpaqueTy { ref generics, bounds, .. }) => {
589 visitor.visit_id(item.hir_id());
590 walk_generics(visitor, generics);
591 walk_list!(visitor, visit_param_bound, bounds);
593 ItemKind::Enum(ref enum_definition, ref generics) => {
594 visitor.visit_generics(generics);
595 // `visit_enum_def()` takes care of visiting the `Item`'s `HirId`.
596 visitor.visit_enum_def(enum_definition, generics, item.hir_id(), item.span)
598 ItemKind::Impl(Impl {
609 visitor.visit_id(item.hir_id());
610 visitor.visit_generics(generics);
611 walk_list!(visitor, visit_trait_ref, of_trait);
612 visitor.visit_ty(self_ty);
613 walk_list!(visitor, visit_impl_item_ref, items);
615 ItemKind::Struct(ref struct_definition, ref generics)
616 | ItemKind::Union(ref struct_definition, ref generics) => {
617 visitor.visit_generics(generics);
618 visitor.visit_id(item.hir_id());
619 visitor.visit_variant_data(
627 ItemKind::Trait(.., ref generics, bounds, trait_item_refs) => {
628 visitor.visit_id(item.hir_id());
629 visitor.visit_generics(generics);
630 walk_list!(visitor, visit_param_bound, bounds);
631 walk_list!(visitor, visit_trait_item_ref, trait_item_refs);
633 ItemKind::TraitAlias(ref generics, bounds) => {
634 visitor.visit_id(item.hir_id());
635 visitor.visit_generics(generics);
636 walk_list!(visitor, visit_param_bound, bounds);
641 fn walk_inline_asm<'v, V: Visitor<'v>>(visitor: &mut V, asm: &'v InlineAsm<'v>) {
642 for (op, _op_sp) in asm.operands {
644 InlineAsmOperand::In { expr, .. }
645 | InlineAsmOperand::InOut { expr, .. }
646 | InlineAsmOperand::Sym { expr, .. } => visitor.visit_expr(expr),
647 InlineAsmOperand::Out { expr, .. } => {
648 if let Some(expr) = expr {
649 visitor.visit_expr(expr);
652 InlineAsmOperand::SplitInOut { in_expr, out_expr, .. } => {
653 visitor.visit_expr(in_expr);
654 if let Some(out_expr) = out_expr {
655 visitor.visit_expr(out_expr);
658 InlineAsmOperand::Const { anon_const } => visitor.visit_anon_const(anon_const),
663 pub fn walk_use<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>, hir_id: HirId) {
664 visitor.visit_id(hir_id);
665 visitor.visit_path(path, hir_id);
668 pub fn walk_enum_def<'v, V: Visitor<'v>>(
670 enum_definition: &'v EnumDef<'v>,
671 generics: &'v Generics<'v>,
674 visitor.visit_id(item_id);
675 walk_list!(visitor, visit_variant, enum_definition.variants, generics, item_id);
678 pub fn walk_variant<'v, V: Visitor<'v>>(
680 variant: &'v Variant<'v>,
681 generics: &'v Generics<'v>,
682 parent_item_id: HirId,
684 visitor.visit_ident(variant.ident);
685 visitor.visit_id(variant.id);
686 visitor.visit_variant_data(
693 walk_list!(visitor, visit_anon_const, &variant.disr_expr);
696 pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty<'v>) {
697 visitor.visit_id(typ.hir_id);
700 TyKind::Slice(ref ty) => visitor.visit_ty(ty),
701 TyKind::Ptr(ref mutable_type) => visitor.visit_ty(&mutable_type.ty),
702 TyKind::Rptr(ref lifetime, ref mutable_type) => {
703 visitor.visit_lifetime(lifetime);
704 visitor.visit_ty(&mutable_type.ty)
707 TyKind::Tup(tuple_element_types) => {
708 walk_list!(visitor, visit_ty, tuple_element_types);
710 TyKind::BareFn(ref function_declaration) => {
711 walk_list!(visitor, visit_generic_param, function_declaration.generic_params);
712 visitor.visit_fn_decl(&function_declaration.decl);
714 TyKind::Path(ref qpath) => {
715 visitor.visit_qpath(qpath, typ.hir_id, typ.span);
717 TyKind::OpaqueDef(item_id, lifetimes) => {
718 visitor.visit_nested_item(item_id);
719 walk_list!(visitor, visit_generic_arg, lifetimes);
721 TyKind::Array(ref ty, ref length) => {
722 visitor.visit_ty(ty);
723 visitor.visit_anon_const(length)
725 TyKind::TraitObject(bounds, ref lifetime, _syntax) => {
726 for bound in bounds {
727 visitor.visit_poly_trait_ref(bound, TraitBoundModifier::None);
729 visitor.visit_lifetime(lifetime);
731 TyKind::Typeof(ref expression) => visitor.visit_anon_const(expression),
732 TyKind::Infer | TyKind::Err => {}
736 pub fn walk_inf<'v, V: Visitor<'v>>(visitor: &mut V, inf: &'v InferArg) {
737 visitor.visit_id(inf.hir_id);
740 pub fn walk_qpath<'v, V: Visitor<'v>>(
742 qpath: &'v QPath<'v>,
747 QPath::Resolved(ref maybe_qself, ref path) => {
748 walk_list!(visitor, visit_ty, maybe_qself);
749 visitor.visit_path(path, id)
751 QPath::TypeRelative(ref qself, ref segment) => {
752 visitor.visit_ty(qself);
753 visitor.visit_path_segment(span, segment);
755 QPath::LangItem(..) => {}
759 pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>) {
760 for segment in path.segments {
761 visitor.visit_path_segment(path.span, segment);
765 pub fn walk_path_segment<'v, V: Visitor<'v>>(
768 segment: &'v PathSegment<'v>,
770 visitor.visit_ident(segment.ident);
771 walk_list!(visitor, visit_id, segment.hir_id);
772 if let Some(ref args) = segment.args {
773 visitor.visit_generic_args(path_span, args);
777 pub fn walk_generic_args<'v, V: Visitor<'v>>(
780 generic_args: &'v GenericArgs<'v>,
782 walk_list!(visitor, visit_generic_arg, generic_args.args);
783 walk_list!(visitor, visit_assoc_type_binding, generic_args.bindings);
786 pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(
788 type_binding: &'v TypeBinding<'v>,
790 visitor.visit_id(type_binding.hir_id);
791 visitor.visit_ident(type_binding.ident);
792 visitor.visit_generic_args(type_binding.span, type_binding.gen_args);
793 match type_binding.kind {
794 TypeBindingKind::Equality { ref ty } => {
795 visitor.visit_ty(ty);
797 TypeBindingKind::Constraint { bounds } => {
798 walk_list!(visitor, visit_param_bound, bounds);
803 pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat<'v>) {
804 visitor.visit_id(pattern.hir_id);
806 PatKind::TupleStruct(ref qpath, children, _) => {
807 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
808 walk_list!(visitor, visit_pat, children);
810 PatKind::Path(ref qpath) => {
811 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
813 PatKind::Struct(ref qpath, fields, _) => {
814 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
815 for field in fields {
816 visitor.visit_id(field.hir_id);
817 visitor.visit_ident(field.ident);
818 visitor.visit_pat(&field.pat)
821 PatKind::Or(pats) => walk_list!(visitor, visit_pat, pats),
822 PatKind::Tuple(tuple_elements, _) => {
823 walk_list!(visitor, visit_pat, tuple_elements);
825 PatKind::Box(ref subpattern) | PatKind::Ref(ref subpattern, _) => {
826 visitor.visit_pat(subpattern)
828 PatKind::Binding(_, _hir_id, ident, ref optional_subpattern) => {
829 visitor.visit_ident(ident);
830 walk_list!(visitor, visit_pat, optional_subpattern);
832 PatKind::Lit(ref expression) => visitor.visit_expr(expression),
833 PatKind::Range(ref lower_bound, ref upper_bound, _) => {
834 walk_list!(visitor, visit_expr, lower_bound);
835 walk_list!(visitor, visit_expr, upper_bound);
838 PatKind::Slice(prepatterns, ref slice_pattern, postpatterns) => {
839 walk_list!(visitor, visit_pat, prepatterns);
840 walk_list!(visitor, visit_pat, slice_pattern);
841 walk_list!(visitor, visit_pat, postpatterns);
846 pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V, foreign_item: &'v ForeignItem<'v>) {
847 visitor.visit_id(foreign_item.hir_id());
848 visitor.visit_vis(&foreign_item.vis);
849 visitor.visit_ident(foreign_item.ident);
851 match foreign_item.kind {
852 ForeignItemKind::Fn(ref function_declaration, param_names, ref generics) => {
853 visitor.visit_generics(generics);
854 visitor.visit_fn_decl(function_declaration);
855 for ¶m_name in param_names {
856 visitor.visit_ident(param_name);
859 ForeignItemKind::Static(ref typ, _) => visitor.visit_ty(typ),
860 ForeignItemKind::Type => (),
864 pub fn walk_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v GenericBound<'v>) {
866 GenericBound::Trait(ref typ, modifier) => {
867 visitor.visit_poly_trait_ref(typ, modifier);
869 GenericBound::LangItemTrait(_, span, hir_id, args) => {
870 visitor.visit_id(hir_id);
871 visitor.visit_generic_args(span, args);
873 GenericBound::Outlives(ref lifetime) => visitor.visit_lifetime(lifetime),
877 pub fn walk_generic_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v GenericParam<'v>) {
878 visitor.visit_id(param.hir_id);
880 ParamName::Plain(ident) => visitor.visit_ident(ident),
881 ParamName::Error | ParamName::Fresh(_) => {}
884 GenericParamKind::Lifetime { .. } => {}
885 GenericParamKind::Type { ref default, .. } => walk_list!(visitor, visit_ty, default),
886 GenericParamKind::Const { ref ty, ref default } => {
887 visitor.visit_ty(ty);
888 if let Some(ref default) = default {
889 visitor.visit_const_param_default(param.hir_id, default);
893 walk_list!(visitor, visit_param_bound, param.bounds);
896 pub fn walk_const_param_default<'v, V: Visitor<'v>>(visitor: &mut V, ct: &'v AnonConst) {
897 visitor.visit_anon_const(ct)
900 pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics<'v>) {
901 walk_list!(visitor, visit_generic_param, generics.params);
902 walk_list!(visitor, visit_where_predicate, generics.where_clause.predicates);
905 pub fn walk_where_predicate<'v, V: Visitor<'v>>(
907 predicate: &'v WherePredicate<'v>,
910 WherePredicate::BoundPredicate(WhereBoundPredicate {
913 bound_generic_params,
916 visitor.visit_ty(bounded_ty);
917 walk_list!(visitor, visit_param_bound, bounds);
918 walk_list!(visitor, visit_generic_param, bound_generic_params);
920 WherePredicate::RegionPredicate(WhereRegionPredicate { ref lifetime, bounds, .. }) => {
921 visitor.visit_lifetime(lifetime);
922 walk_list!(visitor, visit_param_bound, bounds);
924 WherePredicate::EqPredicate(WhereEqPredicate {
925 hir_id, ref lhs_ty, ref rhs_ty, ..
927 visitor.visit_id(hir_id);
928 visitor.visit_ty(lhs_ty);
929 visitor.visit_ty(rhs_ty);
934 pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FnRetTy<'v>) {
935 if let FnRetTy::Return(ref output_ty) = *ret_ty {
936 visitor.visit_ty(output_ty)
940 pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl<'v>) {
941 for ty in function_declaration.inputs {
944 walk_fn_ret_ty(visitor, &function_declaration.output)
947 pub fn walk_fn_kind<'v, V: Visitor<'v>>(visitor: &mut V, function_kind: FnKind<'v>) {
948 match function_kind {
949 FnKind::ItemFn(_, generics, ..) => {
950 visitor.visit_generics(generics);
952 FnKind::Method(..) | FnKind::Closure => {}
956 pub fn walk_fn<'v, V: Visitor<'v>>(
958 function_kind: FnKind<'v>,
959 function_declaration: &'v FnDecl<'v>,
964 visitor.visit_id(id);
965 visitor.visit_fn_decl(function_declaration);
966 walk_fn_kind(visitor, function_kind);
967 visitor.visit_nested_body(body_id)
970 pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem<'v>) {
971 visitor.visit_ident(trait_item.ident);
972 visitor.visit_generics(&trait_item.generics);
973 match trait_item.kind {
974 TraitItemKind::Const(ref ty, default) => {
975 visitor.visit_id(trait_item.hir_id());
976 visitor.visit_ty(ty);
977 walk_list!(visitor, visit_nested_body, default);
979 TraitItemKind::Fn(ref sig, TraitFn::Required(param_names)) => {
980 visitor.visit_id(trait_item.hir_id());
981 visitor.visit_fn_decl(&sig.decl);
982 for ¶m_name in param_names {
983 visitor.visit_ident(param_name);
986 TraitItemKind::Fn(ref sig, TraitFn::Provided(body_id)) => {
988 FnKind::Method(trait_item.ident, sig, None),
995 TraitItemKind::Type(bounds, ref default) => {
996 visitor.visit_id(trait_item.hir_id());
997 walk_list!(visitor, visit_param_bound, bounds);
998 walk_list!(visitor, visit_ty, default);
1003 pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref: &'v TraitItemRef) {
1004 // N.B., deliberately force a compilation error if/when new fields are added.
1005 let TraitItemRef { id, ident, ref kind, span: _, ref defaultness } = *trait_item_ref;
1006 visitor.visit_nested_trait_item(id);
1007 visitor.visit_ident(ident);
1008 visitor.visit_associated_item_kind(kind);
1009 visitor.visit_defaultness(defaultness);
1012 pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem<'v>) {
1013 // N.B., deliberately force a compilation error if/when new fields are added.
1014 let ImplItem { def_id: _, ident, ref vis, ref defaultness, ref generics, ref kind, span: _ } =
1017 visitor.visit_ident(ident);
1018 visitor.visit_vis(vis);
1019 visitor.visit_defaultness(defaultness);
1020 visitor.visit_generics(generics);
1022 ImplItemKind::Const(ref ty, body) => {
1023 visitor.visit_id(impl_item.hir_id());
1024 visitor.visit_ty(ty);
1025 visitor.visit_nested_body(body);
1027 ImplItemKind::Fn(ref sig, body_id) => {
1029 FnKind::Method(impl_item.ident, sig, Some(&impl_item.vis)),
1036 ImplItemKind::TyAlias(ref ty) => {
1037 visitor.visit_id(impl_item.hir_id());
1038 visitor.visit_ty(ty);
1043 pub fn walk_foreign_item_ref<'v, V: Visitor<'v>>(
1045 foreign_item_ref: &'v ForeignItemRef,
1047 // N.B., deliberately force a compilation error if/when new fields are added.
1048 let ForeignItemRef { id, ident, span: _ } = *foreign_item_ref;
1049 visitor.visit_nested_foreign_item(id);
1050 visitor.visit_ident(ident);
1053 pub fn walk_impl_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, impl_item_ref: &'v ImplItemRef) {
1054 // N.B., deliberately force a compilation error if/when new fields are added.
1055 let ImplItemRef { id, ident, ref kind, span: _, ref defaultness } = *impl_item_ref;
1056 visitor.visit_nested_impl_item(id);
1057 visitor.visit_ident(ident);
1058 visitor.visit_associated_item_kind(kind);
1059 visitor.visit_defaultness(defaultness);
1062 pub fn walk_struct_def<'v, V: Visitor<'v>>(
1064 struct_definition: &'v VariantData<'v>,
1066 walk_list!(visitor, visit_id, struct_definition.ctor_hir_id());
1067 walk_list!(visitor, visit_field_def, struct_definition.fields());
1070 pub fn walk_field_def<'v, V: Visitor<'v>>(visitor: &mut V, field: &'v FieldDef<'v>) {
1071 visitor.visit_id(field.hir_id);
1072 visitor.visit_vis(&field.vis);
1073 visitor.visit_ident(field.ident);
1074 visitor.visit_ty(&field.ty);
1077 pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block<'v>) {
1078 visitor.visit_id(block.hir_id);
1079 walk_list!(visitor, visit_stmt, block.stmts);
1080 walk_list!(visitor, visit_expr, &block.expr);
1083 pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt<'v>) {
1084 visitor.visit_id(statement.hir_id);
1085 match statement.kind {
1086 StmtKind::Local(ref local) => visitor.visit_local(local),
1087 StmtKind::Item(item) => visitor.visit_nested_item(item),
1088 StmtKind::Expr(ref expression) | StmtKind::Semi(ref expression) => {
1089 visitor.visit_expr(expression)
1094 pub fn walk_anon_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v AnonConst) {
1095 visitor.visit_id(constant.hir_id);
1096 visitor.visit_nested_body(constant.body);
1099 pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>) {
1100 visitor.visit_id(expression.hir_id);
1101 match expression.kind {
1102 ExprKind::Box(ref subexpression) => visitor.visit_expr(subexpression),
1103 ExprKind::Array(subexpressions) => {
1104 walk_list!(visitor, visit_expr, subexpressions);
1106 ExprKind::ConstBlock(ref anon_const) => visitor.visit_anon_const(anon_const),
1107 ExprKind::Repeat(ref element, ref count) => {
1108 visitor.visit_expr(element);
1109 visitor.visit_anon_const(count)
1111 ExprKind::Struct(ref qpath, fields, ref optional_base) => {
1112 visitor.visit_qpath(qpath, expression.hir_id, expression.span);
1113 for field in fields {
1114 visitor.visit_id(field.hir_id);
1115 visitor.visit_ident(field.ident);
1116 visitor.visit_expr(&field.expr)
1118 walk_list!(visitor, visit_expr, optional_base);
1120 ExprKind::Tup(subexpressions) => {
1121 walk_list!(visitor, visit_expr, subexpressions);
1123 ExprKind::Call(ref callee_expression, arguments) => {
1124 visitor.visit_expr(callee_expression);
1125 walk_list!(visitor, visit_expr, arguments);
1127 ExprKind::MethodCall(ref segment, _, arguments, _) => {
1128 visitor.visit_path_segment(expression.span, segment);
1129 walk_list!(visitor, visit_expr, arguments);
1131 ExprKind::Binary(_, ref left_expression, ref right_expression) => {
1132 visitor.visit_expr(left_expression);
1133 visitor.visit_expr(right_expression)
1135 ExprKind::AddrOf(_, _, ref subexpression) | ExprKind::Unary(_, ref subexpression) => {
1136 visitor.visit_expr(subexpression)
1138 ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => {
1139 visitor.visit_expr(subexpression);
1140 visitor.visit_ty(typ)
1142 ExprKind::DropTemps(ref subexpression) => {
1143 visitor.visit_expr(subexpression);
1145 ExprKind::Let(ref pat, ref expr, _) => {
1146 visitor.visit_expr(expr);
1147 visitor.visit_pat(pat);
1149 ExprKind::If(ref cond, ref then, ref else_opt) => {
1150 visitor.visit_expr(cond);
1151 visitor.visit_expr(then);
1152 walk_list!(visitor, visit_expr, else_opt);
1154 ExprKind::Loop(ref block, ref opt_label, _, _) => {
1155 walk_list!(visitor, visit_label, opt_label);
1156 visitor.visit_block(block);
1158 ExprKind::Match(ref subexpression, arms, _) => {
1159 visitor.visit_expr(subexpression);
1160 walk_list!(visitor, visit_arm, arms);
1162 ExprKind::Closure(_, ref function_declaration, body, _fn_decl_span, _gen) => visitor
1165 function_declaration,
1170 ExprKind::Block(ref block, ref opt_label) => {
1171 walk_list!(visitor, visit_label, opt_label);
1172 visitor.visit_block(block);
1174 ExprKind::Assign(ref lhs, ref rhs, _) => {
1175 visitor.visit_expr(rhs);
1176 visitor.visit_expr(lhs)
1178 ExprKind::AssignOp(_, ref left_expression, ref right_expression) => {
1179 visitor.visit_expr(right_expression);
1180 visitor.visit_expr(left_expression);
1182 ExprKind::Field(ref subexpression, ident) => {
1183 visitor.visit_expr(subexpression);
1184 visitor.visit_ident(ident);
1186 ExprKind::Index(ref main_expression, ref index_expression) => {
1187 visitor.visit_expr(main_expression);
1188 visitor.visit_expr(index_expression)
1190 ExprKind::Path(ref qpath) => {
1191 visitor.visit_qpath(qpath, expression.hir_id, expression.span);
1193 ExprKind::Break(ref destination, ref opt_expr) => {
1194 walk_list!(visitor, visit_label, &destination.label);
1195 walk_list!(visitor, visit_expr, opt_expr);
1197 ExprKind::Continue(ref destination) => {
1198 walk_list!(visitor, visit_label, &destination.label);
1200 ExprKind::Ret(ref optional_expression) => {
1201 walk_list!(visitor, visit_expr, optional_expression);
1203 ExprKind::InlineAsm(ref asm) => {
1204 walk_inline_asm(visitor, asm);
1206 ExprKind::LlvmInlineAsm(ref asm) => {
1207 walk_list!(visitor, visit_expr, asm.outputs_exprs);
1208 walk_list!(visitor, visit_expr, asm.inputs_exprs);
1210 ExprKind::Yield(ref subexpression, _) => {
1211 visitor.visit_expr(subexpression);
1213 ExprKind::Lit(_) | ExprKind::Err => {}
1217 pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm<'v>) {
1218 visitor.visit_id(arm.hir_id);
1219 visitor.visit_pat(&arm.pat);
1220 if let Some(ref g) = arm.guard {
1222 Guard::If(ref e) => visitor.visit_expr(e),
1223 Guard::IfLet(ref pat, ref e) => {
1224 visitor.visit_pat(pat);
1225 visitor.visit_expr(e);
1229 visitor.visit_expr(&arm.body);
1232 pub fn walk_vis<'v, V: Visitor<'v>>(visitor: &mut V, vis: &'v Visibility<'v>) {
1233 if let VisibilityKind::Restricted { ref path, hir_id } = vis.node {
1234 visitor.visit_id(hir_id);
1235 visitor.visit_path(path, hir_id)
1239 pub fn walk_associated_item_kind<'v, V: Visitor<'v>>(_: &mut V, _: &'v AssocItemKind) {
1240 // No visitable content here: this fn exists so you can call it if
1241 // the right thing to do, should content be added in the future,
1242 // would be to walk it.
1245 pub fn walk_defaultness<'v, V: Visitor<'v>>(_: &mut V, _: &'v Defaultness) {
1246 // No visitable content here: this fn exists so you can call it if
1247 // the right thing to do, should content be added in the future,
1248 // would be to walk it.