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,
121 pub fn constness(self) -> Constness {
122 self.header().map_or(Constness::NotConst, |header| header.constness)
125 pub fn asyncness(self) -> IsAsync {
126 self.header().map_or(IsAsync::NotAsync, |header| header.asyncness)
130 /// An abstract representation of the HIR `rustc_middle::hir::map::Map`.
131 pub trait Map<'hir> {
132 /// Retrieves the `Node` corresponding to `id`, returning `None` if cannot be found.
133 fn find(&self, hir_id: HirId) -> Option<Node<'hir>>;
134 fn body(&self, id: BodyId) -> &'hir Body<'hir>;
135 fn item(&self, id: ItemId) -> &'hir Item<'hir>;
136 fn trait_item(&self, id: TraitItemId) -> &'hir TraitItem<'hir>;
137 fn impl_item(&self, id: ImplItemId) -> &'hir ImplItem<'hir>;
138 fn foreign_item(&self, id: ForeignItemId) -> &'hir ForeignItem<'hir>;
141 // Used when no map is actually available, forcing manual implementation of nested visitors.
142 impl<'hir> Map<'hir> for ! {
143 fn find(&self, _: HirId) -> Option<Node<'hir>> {
146 fn body(&self, _: BodyId) -> &'hir Body<'hir> {
149 fn item(&self, _: ItemId) -> &'hir Item<'hir> {
152 fn trait_item(&self, _: TraitItemId) -> &'hir TraitItem<'hir> {
155 fn impl_item(&self, _: ImplItemId) -> &'hir ImplItem<'hir> {
158 fn foreign_item(&self, _: ForeignItemId) -> &'hir ForeignItem<'hir> {
163 pub mod nested_filter {
166 /// Specifies what nested things a visitor wants to visit. The most
167 /// common choice is `OnlyBodies`, which will cause the visitor to
168 /// visit fn bodies for fns that it encounters, but skip over nested
169 /// item-like things.
171 /// See the comments on `ItemLikeVisitor` for more details on the overall
173 pub trait NestedFilter<'hir> {
176 /// Whether the visitor visits nested "item-like" things.
177 /// E.g., item, impl-item.
179 /// Whether the visitor visits "intra item-like" things.
180 /// E.g., function body, closure, `AnonConst`
184 /// Do not visit any nested things. When you add a new
185 /// "non-nested" thing, you will want to audit such uses to see if
186 /// they remain valid.
188 /// Use this if you are only walking some particular kind of tree
189 /// (i.e., a type, or fn signature) and you don't want to thread a
192 impl NestedFilter<'_> for None {
194 const INTER: bool = false;
195 const INTRA: bool = false;
199 use nested_filter::NestedFilter;
201 /// Each method of the Visitor trait is a hook to be potentially
202 /// overridden. Each method's default implementation recursively visits
203 /// the substructure of the input via the corresponding `walk` method;
204 /// e.g., the `visit_mod` method by default calls `intravisit::walk_mod`.
206 /// Note that this visitor does NOT visit nested items by default
207 /// (this is why the module is called `intravisit`, to distinguish it
208 /// from the AST's `visit` module, which acts differently). If you
209 /// simply want to visit all items in the crate in some order, you
210 /// should call `Crate::visit_all_items`. Otherwise, see the comment
211 /// on `visit_nested_item` for details on how to visit nested items.
213 /// If you want to ensure that your code handles every variant
214 /// explicitly, you need to override each method. (And you also need
215 /// to monitor future changes to `Visitor` in case a new method with a
216 /// new default implementation gets introduced.)
217 pub trait Visitor<'v>: Sized {
218 // this type should not be overridden, it exists for convenient usage as `Self::Map`
219 type Map: Map<'v> = <Self::NestedFilter as NestedFilter<'v>>::Map;
220 type NestedFilter: NestedFilter<'v> = nested_filter::None;
222 ///////////////////////////////////////////////////////////////////////////
225 /// The default versions of the `visit_nested_XXX` routines invoke
226 /// this method to get a map to use. By selecting an enum variant,
227 /// you control which kinds of nested HIR are visited; see
228 /// `NestedVisitorMap` for details. By "nested HIR", we are
229 /// referring to bits of HIR that are not directly embedded within
230 /// one another but rather indirectly, through a table in the
231 /// crate. This is done to control dependencies during incremental
232 /// compilation: the non-inline bits of HIR can be tracked and
233 /// hashed separately.
235 /// **If for some reason you want the nested behavior, but don't
236 /// have a `Map` at your disposal:** then you should override the
237 /// `visit_nested_XXX` methods, and override this method to
238 /// `panic!()`. This way, if a new `visit_nested_XXX` variant is
239 /// added in the future, we will see the panic in your code and
240 /// fix it appropriately.
241 fn nested_visit_map(&mut self) -> Self::Map {
243 "nested_visit_map must be implemented or consider using \
244 `type NestedFilter = nested_filter::None` (the default)"
248 /// Invoked when a nested item is encountered. By default does
249 /// nothing unless you override `nested_visit_map` to return other than
250 /// `None`, in which case it will walk the item. **You probably
251 /// don't want to override this method** -- instead, override
252 /// `nested_visit_map` or use the "shallow" or "deep" visit
253 /// patterns described on `itemlikevisit::ItemLikeVisitor`. The only
254 /// reason to override this method is if you want a nested pattern
255 /// but cannot supply a `Map`; see `nested_visit_map` for advice.
256 fn visit_nested_item(&mut self, id: ItemId) {
257 if Self::NestedFilter::INTER {
258 let item = self.nested_visit_map().item(id);
259 self.visit_item(item);
263 /// Like `visit_nested_item()`, but for trait items. See
264 /// `visit_nested_item()` for advice on when to override this
266 fn visit_nested_trait_item(&mut self, id: TraitItemId) {
267 if Self::NestedFilter::INTER {
268 let item = self.nested_visit_map().trait_item(id);
269 self.visit_trait_item(item);
273 /// Like `visit_nested_item()`, but for impl items. See
274 /// `visit_nested_item()` for advice on when to override this
276 fn visit_nested_impl_item(&mut self, id: ImplItemId) {
277 if Self::NestedFilter::INTER {
278 let item = self.nested_visit_map().impl_item(id);
279 self.visit_impl_item(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 if Self::NestedFilter::INTER {
288 let item = self.nested_visit_map().foreign_item(id);
289 self.visit_foreign_item(item);
293 /// Invoked to visit the body of a function, method or closure. Like
294 /// visit_nested_item, does nothing by default unless you override
295 /// `nested_visit_map` to return other than `None`, in which case it will walk
297 fn visit_nested_body(&mut self, id: BodyId) {
298 if Self::NestedFilter::INTRA {
299 let body = self.nested_visit_map().body(id);
300 self.visit_body(body);
304 fn visit_param(&mut self, param: &'v Param<'v>) {
305 walk_param(self, param)
308 /// Visits the top-level item and (optionally) nested items / impl items. See
309 /// `visit_nested_item` for details.
310 fn visit_item(&mut self, i: &'v Item<'v>) {
314 fn visit_body(&mut self, b: &'v Body<'v>) {
318 /// When invoking `visit_all_item_likes()`, you need to supply an
319 /// item-like visitor. This method converts an "intra-visit"
320 /// visitor into an item-like visitor that walks the entire tree.
321 /// If you use this, you probably don't want to process the
322 /// contents of nested item-like things, since the outer loop will
323 /// visit them as well.
324 fn as_deep_visitor(&mut self) -> DeepVisitor<'_, Self> {
325 DeepVisitor::new(self)
328 ///////////////////////////////////////////////////////////////////////////
330 fn visit_id(&mut self, _hir_id: HirId) {
333 fn visit_name(&mut self, _span: Span, _name: Symbol) {
336 fn visit_ident(&mut self, ident: Ident) {
337 walk_ident(self, ident)
339 fn visit_mod(&mut self, m: &'v Mod<'v>, _s: Span, n: HirId) {
342 fn visit_foreign_item(&mut self, i: &'v ForeignItem<'v>) {
343 walk_foreign_item(self, i)
345 fn visit_local(&mut self, l: &'v Local<'v>) {
348 fn visit_block(&mut self, b: &'v Block<'v>) {
351 fn visit_stmt(&mut self, s: &'v Stmt<'v>) {
354 fn visit_arm(&mut self, a: &'v Arm<'v>) {
357 fn visit_pat(&mut self, p: &'v Pat<'v>) {
360 fn visit_array_length(&mut self, len: &'v ArrayLen) {
361 walk_array_len(self, len)
363 fn visit_anon_const(&mut self, c: &'v AnonConst) {
364 walk_anon_const(self, c)
366 fn visit_expr(&mut self, ex: &'v Expr<'v>) {
369 fn visit_let_expr(&mut self, lex: &'v Let<'v>) {
370 walk_let_expr(self, lex)
372 fn visit_ty(&mut self, t: &'v Ty<'v>) {
375 fn visit_generic_param(&mut self, p: &'v GenericParam<'v>) {
376 walk_generic_param(self, p)
378 fn visit_const_param_default(&mut self, _param: HirId, ct: &'v AnonConst) {
379 walk_const_param_default(self, ct)
381 fn visit_generics(&mut self, g: &'v Generics<'v>) {
382 walk_generics(self, g)
384 fn visit_where_predicate(&mut self, predicate: &'v WherePredicate<'v>) {
385 walk_where_predicate(self, predicate)
387 fn visit_fn_decl(&mut self, fd: &'v FnDecl<'v>) {
388 walk_fn_decl(self, fd)
390 fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl<'v>, b: BodyId, s: Span, id: HirId) {
391 walk_fn(self, fk, fd, b, s, id)
393 fn visit_use(&mut self, path: &'v Path<'v>, hir_id: HirId) {
394 walk_use(self, path, hir_id)
396 fn visit_trait_item(&mut self, ti: &'v TraitItem<'v>) {
397 walk_trait_item(self, ti)
399 fn visit_trait_item_ref(&mut self, ii: &'v TraitItemRef) {
400 walk_trait_item_ref(self, ii)
402 fn visit_impl_item(&mut self, ii: &'v ImplItem<'v>) {
403 walk_impl_item(self, ii)
405 fn visit_foreign_item_ref(&mut self, ii: &'v ForeignItemRef) {
406 walk_foreign_item_ref(self, ii)
408 fn visit_impl_item_ref(&mut self, ii: &'v ImplItemRef) {
409 walk_impl_item_ref(self, ii)
411 fn visit_trait_ref(&mut self, t: &'v TraitRef<'v>) {
412 walk_trait_ref(self, t)
414 fn visit_param_bound(&mut self, bounds: &'v GenericBound<'v>) {
415 walk_param_bound(self, bounds)
417 fn visit_poly_trait_ref(&mut self, t: &'v PolyTraitRef<'v>, m: TraitBoundModifier) {
418 walk_poly_trait_ref(self, t, m)
420 fn visit_variant_data(
422 s: &'v VariantData<'v>,
428 walk_struct_def(self, s)
430 fn visit_field_def(&mut self, s: &'v FieldDef<'v>) {
431 walk_field_def(self, s)
435 enum_definition: &'v EnumDef<'v>,
436 generics: &'v Generics<'v>,
440 walk_enum_def(self, enum_definition, generics, item_id)
442 fn visit_variant(&mut self, v: &'v Variant<'v>, g: &'v Generics<'v>, item_id: HirId) {
443 walk_variant(self, v, g, item_id)
445 fn visit_label(&mut self, label: &'v Label) {
446 walk_label(self, label)
448 fn visit_infer(&mut self, inf: &'v InferArg) {
451 fn visit_generic_arg(&mut self, generic_arg: &'v GenericArg<'v>) {
453 GenericArg::Lifetime(lt) => self.visit_lifetime(lt),
454 GenericArg::Type(ty) => self.visit_ty(ty),
455 GenericArg::Const(ct) => self.visit_anon_const(&ct.value),
456 GenericArg::Infer(inf) => self.visit_infer(inf),
459 fn visit_lifetime(&mut self, lifetime: &'v Lifetime) {
460 walk_lifetime(self, lifetime)
462 fn visit_qpath(&mut self, qpath: &'v QPath<'v>, id: HirId, span: Span) {
463 walk_qpath(self, qpath, id, span)
465 fn visit_path(&mut self, path: &'v Path<'v>, _id: HirId) {
466 walk_path(self, path)
468 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'v PathSegment<'v>) {
469 walk_path_segment(self, path_span, path_segment)
471 fn visit_generic_args(&mut self, path_span: Span, generic_args: &'v GenericArgs<'v>) {
472 walk_generic_args(self, path_span, generic_args)
474 fn visit_assoc_type_binding(&mut self, type_binding: &'v TypeBinding<'v>) {
475 walk_assoc_type_binding(self, type_binding)
477 fn visit_attribute(&mut self, _id: HirId, _attr: &'v Attribute) {}
478 fn visit_vis(&mut self, vis: &'v Visibility<'v>) {
481 fn visit_associated_item_kind(&mut self, kind: &'v AssocItemKind) {
482 walk_associated_item_kind(self, kind);
484 fn visit_defaultness(&mut self, defaultness: &'v Defaultness) {
485 walk_defaultness(self, defaultness);
487 fn visit_inline_asm(&mut self, asm: &'v InlineAsm<'v>, id: HirId) {
488 walk_inline_asm(self, asm, id);
492 pub fn walk_mod<'v, V: Visitor<'v>>(visitor: &mut V, module: &'v Mod<'v>, mod_hir_id: HirId) {
493 visitor.visit_id(mod_hir_id);
494 for &item_id in module.item_ids {
495 visitor.visit_nested_item(item_id);
499 pub fn walk_body<'v, V: Visitor<'v>>(visitor: &mut V, body: &'v Body<'v>) {
500 walk_list!(visitor, visit_param, body.params);
501 visitor.visit_expr(&body.value);
504 pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local<'v>) {
505 // Intentionally visiting the expr first - the initialization expr
506 // dominates the local's definition.
507 walk_list!(visitor, visit_expr, &local.init);
508 visitor.visit_id(local.hir_id);
509 visitor.visit_pat(&local.pat);
510 walk_list!(visitor, visit_ty, &local.ty);
513 pub fn walk_ident<'v, V: Visitor<'v>>(visitor: &mut V, ident: Ident) {
514 visitor.visit_name(ident.span, ident.name);
517 pub fn walk_label<'v, V: Visitor<'v>>(visitor: &mut V, label: &'v Label) {
518 visitor.visit_ident(label.ident);
521 pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) {
522 visitor.visit_id(lifetime.hir_id);
523 match lifetime.name {
524 LifetimeName::Param(ParamName::Plain(ident)) => {
525 visitor.visit_ident(ident);
527 LifetimeName::Param(ParamName::Fresh(_))
528 | LifetimeName::Param(ParamName::Error)
529 | LifetimeName::Static
530 | LifetimeName::Error
531 | LifetimeName::Implicit
532 | LifetimeName::ImplicitObjectLifetimeDefault
533 | LifetimeName::Underscore => {}
537 pub fn walk_poly_trait_ref<'v, V: Visitor<'v>>(
539 trait_ref: &'v PolyTraitRef<'v>,
540 _modifier: TraitBoundModifier,
542 walk_list!(visitor, visit_generic_param, trait_ref.bound_generic_params);
543 visitor.visit_trait_ref(&trait_ref.trait_ref);
546 pub fn walk_trait_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_ref: &'v TraitRef<'v>) {
547 visitor.visit_id(trait_ref.hir_ref_id);
548 visitor.visit_path(&trait_ref.path, trait_ref.hir_ref_id)
551 pub fn walk_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v Param<'v>) {
552 visitor.visit_id(param.hir_id);
553 visitor.visit_pat(¶m.pat);
556 pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item<'v>) {
557 visitor.visit_vis(&item.vis);
558 visitor.visit_ident(item.ident);
560 ItemKind::ExternCrate(orig_name) => {
561 visitor.visit_id(item.hir_id());
562 if let Some(orig_name) = orig_name {
563 visitor.visit_name(item.span, orig_name);
566 ItemKind::Use(ref path, _) => {
567 visitor.visit_use(path, item.hir_id());
569 ItemKind::Static(ref typ, _, body) | ItemKind::Const(ref typ, body) => {
570 visitor.visit_id(item.hir_id());
571 visitor.visit_ty(typ);
572 visitor.visit_nested_body(body);
574 ItemKind::Fn(ref sig, ref generics, body_id) => visitor.visit_fn(
575 FnKind::ItemFn(item.ident, generics, sig.header, &item.vis),
581 ItemKind::Macro(..) => {
582 visitor.visit_id(item.hir_id());
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(asm) => {
593 visitor.visit_id(item.hir_id());
594 visitor.visit_inline_asm(asm, item.hir_id());
596 ItemKind::TyAlias(ref ty, ref generics) => {
597 visitor.visit_id(item.hir_id());
598 visitor.visit_ty(ty);
599 visitor.visit_generics(generics)
601 ItemKind::OpaqueTy(OpaqueTy { ref generics, bounds, .. }) => {
602 visitor.visit_id(item.hir_id());
603 walk_generics(visitor, generics);
604 walk_list!(visitor, visit_param_bound, bounds);
606 ItemKind::Enum(ref enum_definition, ref generics) => {
607 visitor.visit_generics(generics);
608 // `visit_enum_def()` takes care of visiting the `Item`'s `HirId`.
609 visitor.visit_enum_def(enum_definition, generics, item.hir_id(), item.span)
611 ItemKind::Impl(Impl {
622 visitor.visit_id(item.hir_id());
623 visitor.visit_generics(generics);
624 walk_list!(visitor, visit_trait_ref, of_trait);
625 visitor.visit_ty(self_ty);
626 walk_list!(visitor, visit_impl_item_ref, items);
628 ItemKind::Struct(ref struct_definition, ref generics)
629 | ItemKind::Union(ref struct_definition, ref generics) => {
630 visitor.visit_generics(generics);
631 visitor.visit_id(item.hir_id());
632 visitor.visit_variant_data(
640 ItemKind::Trait(.., ref generics, bounds, trait_item_refs) => {
641 visitor.visit_id(item.hir_id());
642 visitor.visit_generics(generics);
643 walk_list!(visitor, visit_param_bound, bounds);
644 walk_list!(visitor, visit_trait_item_ref, trait_item_refs);
646 ItemKind::TraitAlias(ref generics, bounds) => {
647 visitor.visit_id(item.hir_id());
648 visitor.visit_generics(generics);
649 walk_list!(visitor, visit_param_bound, bounds);
654 pub fn walk_inline_asm<'v, V: Visitor<'v>>(visitor: &mut V, asm: &'v InlineAsm<'v>, id: HirId) {
655 for (op, op_sp) in asm.operands {
657 InlineAsmOperand::In { expr, .. } | InlineAsmOperand::InOut { expr, .. } => {
658 visitor.visit_expr(expr)
660 InlineAsmOperand::Out { expr, .. } => {
661 if let Some(expr) = expr {
662 visitor.visit_expr(expr);
665 InlineAsmOperand::SplitInOut { in_expr, out_expr, .. } => {
666 visitor.visit_expr(in_expr);
667 if let Some(out_expr) = out_expr {
668 visitor.visit_expr(out_expr);
671 InlineAsmOperand::Const { anon_const, .. }
672 | InlineAsmOperand::SymFn { anon_const, .. } => visitor.visit_anon_const(anon_const),
673 InlineAsmOperand::SymStatic { path, .. } => visitor.visit_qpath(path, id, *op_sp),
678 pub fn walk_use<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>, hir_id: HirId) {
679 visitor.visit_id(hir_id);
680 visitor.visit_path(path, hir_id);
683 pub fn walk_enum_def<'v, V: Visitor<'v>>(
685 enum_definition: &'v EnumDef<'v>,
686 generics: &'v Generics<'v>,
689 visitor.visit_id(item_id);
690 walk_list!(visitor, visit_variant, enum_definition.variants, generics, item_id);
693 pub fn walk_variant<'v, V: Visitor<'v>>(
695 variant: &'v Variant<'v>,
696 generics: &'v Generics<'v>,
697 parent_item_id: HirId,
699 visitor.visit_ident(variant.ident);
700 visitor.visit_id(variant.id);
701 visitor.visit_variant_data(
708 walk_list!(visitor, visit_anon_const, &variant.disr_expr);
711 pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty<'v>) {
712 visitor.visit_id(typ.hir_id);
715 TyKind::Slice(ref ty) => visitor.visit_ty(ty),
716 TyKind::Ptr(ref mutable_type) => visitor.visit_ty(&mutable_type.ty),
717 TyKind::Rptr(ref lifetime, ref mutable_type) => {
718 visitor.visit_lifetime(lifetime);
719 visitor.visit_ty(&mutable_type.ty)
722 TyKind::Tup(tuple_element_types) => {
723 walk_list!(visitor, visit_ty, tuple_element_types);
725 TyKind::BareFn(ref function_declaration) => {
726 walk_list!(visitor, visit_generic_param, function_declaration.generic_params);
727 visitor.visit_fn_decl(&function_declaration.decl);
729 TyKind::Path(ref qpath) => {
730 visitor.visit_qpath(qpath, typ.hir_id, typ.span);
732 TyKind::OpaqueDef(item_id, lifetimes) => {
733 visitor.visit_nested_item(item_id);
734 walk_list!(visitor, visit_generic_arg, lifetimes);
736 TyKind::Array(ref ty, ref length) => {
737 visitor.visit_ty(ty);
738 visitor.visit_array_length(length)
740 TyKind::TraitObject(bounds, ref lifetime, _syntax) => {
741 for bound in bounds {
742 visitor.visit_poly_trait_ref(bound, TraitBoundModifier::None);
744 visitor.visit_lifetime(lifetime);
746 TyKind::Typeof(ref expression) => visitor.visit_anon_const(expression),
747 TyKind::Infer | TyKind::Err => {}
751 pub fn walk_inf<'v, V: Visitor<'v>>(visitor: &mut V, inf: &'v InferArg) {
752 visitor.visit_id(inf.hir_id);
755 pub fn walk_qpath<'v, V: Visitor<'v>>(
757 qpath: &'v QPath<'v>,
762 QPath::Resolved(ref maybe_qself, ref path) => {
763 walk_list!(visitor, visit_ty, maybe_qself);
764 visitor.visit_path(path, id)
766 QPath::TypeRelative(ref qself, ref segment) => {
767 visitor.visit_ty(qself);
768 visitor.visit_path_segment(span, segment);
770 QPath::LangItem(..) => {}
774 pub fn walk_path<'v, V: Visitor<'v>>(visitor: &mut V, path: &'v Path<'v>) {
775 for segment in path.segments {
776 visitor.visit_path_segment(path.span, segment);
780 pub fn walk_path_segment<'v, V: Visitor<'v>>(
783 segment: &'v PathSegment<'v>,
785 visitor.visit_ident(segment.ident);
786 walk_list!(visitor, visit_id, segment.hir_id);
787 if let Some(ref args) = segment.args {
788 visitor.visit_generic_args(path_span, args);
792 pub fn walk_generic_args<'v, V: Visitor<'v>>(
795 generic_args: &'v GenericArgs<'v>,
797 walk_list!(visitor, visit_generic_arg, generic_args.args);
798 walk_list!(visitor, visit_assoc_type_binding, generic_args.bindings);
801 pub fn walk_assoc_type_binding<'v, V: Visitor<'v>>(
803 type_binding: &'v TypeBinding<'v>,
805 visitor.visit_id(type_binding.hir_id);
806 visitor.visit_ident(type_binding.ident);
807 visitor.visit_generic_args(type_binding.span, type_binding.gen_args);
808 match type_binding.kind {
809 TypeBindingKind::Equality { ref term } => match term {
810 Term::Ty(ref ty) => visitor.visit_ty(ty),
811 Term::Const(ref c) => visitor.visit_anon_const(c),
813 TypeBindingKind::Constraint { bounds } => walk_list!(visitor, visit_param_bound, bounds),
817 pub fn walk_pat<'v, V: Visitor<'v>>(visitor: &mut V, pattern: &'v Pat<'v>) {
818 visitor.visit_id(pattern.hir_id);
820 PatKind::TupleStruct(ref qpath, children, _) => {
821 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
822 walk_list!(visitor, visit_pat, children);
824 PatKind::Path(ref qpath) => {
825 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
827 PatKind::Struct(ref qpath, fields, _) => {
828 visitor.visit_qpath(qpath, pattern.hir_id, pattern.span);
829 for field in fields {
830 visitor.visit_id(field.hir_id);
831 visitor.visit_ident(field.ident);
832 visitor.visit_pat(&field.pat)
835 PatKind::Or(pats) => walk_list!(visitor, visit_pat, pats),
836 PatKind::Tuple(tuple_elements, _) => {
837 walk_list!(visitor, visit_pat, tuple_elements);
839 PatKind::Box(ref subpattern) | PatKind::Ref(ref subpattern, _) => {
840 visitor.visit_pat(subpattern)
842 PatKind::Binding(_, _hir_id, ident, ref optional_subpattern) => {
843 visitor.visit_ident(ident);
844 walk_list!(visitor, visit_pat, optional_subpattern);
846 PatKind::Lit(ref expression) => visitor.visit_expr(expression),
847 PatKind::Range(ref lower_bound, ref upper_bound, _) => {
848 walk_list!(visitor, visit_expr, lower_bound);
849 walk_list!(visitor, visit_expr, upper_bound);
852 PatKind::Slice(prepatterns, ref slice_pattern, postpatterns) => {
853 walk_list!(visitor, visit_pat, prepatterns);
854 walk_list!(visitor, visit_pat, slice_pattern);
855 walk_list!(visitor, visit_pat, postpatterns);
860 pub fn walk_foreign_item<'v, V: Visitor<'v>>(visitor: &mut V, foreign_item: &'v ForeignItem<'v>) {
861 visitor.visit_id(foreign_item.hir_id());
862 visitor.visit_vis(&foreign_item.vis);
863 visitor.visit_ident(foreign_item.ident);
865 match foreign_item.kind {
866 ForeignItemKind::Fn(ref function_declaration, param_names, ref generics) => {
867 visitor.visit_generics(generics);
868 visitor.visit_fn_decl(function_declaration);
869 for ¶m_name in param_names {
870 visitor.visit_ident(param_name);
873 ForeignItemKind::Static(ref typ, _) => visitor.visit_ty(typ),
874 ForeignItemKind::Type => (),
878 pub fn walk_param_bound<'v, V: Visitor<'v>>(visitor: &mut V, bound: &'v GenericBound<'v>) {
880 GenericBound::Trait(ref typ, modifier) => {
881 visitor.visit_poly_trait_ref(typ, modifier);
883 GenericBound::LangItemTrait(_, span, hir_id, args) => {
884 visitor.visit_id(hir_id);
885 visitor.visit_generic_args(span, args);
887 GenericBound::Outlives(ref lifetime) => visitor.visit_lifetime(lifetime),
891 pub fn walk_generic_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v GenericParam<'v>) {
892 visitor.visit_id(param.hir_id);
894 ParamName::Plain(ident) => visitor.visit_ident(ident),
895 ParamName::Error | ParamName::Fresh(_) => {}
898 GenericParamKind::Lifetime { .. } => {}
899 GenericParamKind::Type { ref default, .. } => walk_list!(visitor, visit_ty, default),
900 GenericParamKind::Const { ref ty, ref default } => {
901 visitor.visit_ty(ty);
902 if let Some(ref default) = default {
903 visitor.visit_const_param_default(param.hir_id, default);
907 walk_list!(visitor, visit_param_bound, param.bounds);
910 pub fn walk_const_param_default<'v, V: Visitor<'v>>(visitor: &mut V, ct: &'v AnonConst) {
911 visitor.visit_anon_const(ct)
914 pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics<'v>) {
915 walk_list!(visitor, visit_generic_param, generics.params);
916 walk_list!(visitor, visit_where_predicate, generics.where_clause.predicates);
919 pub fn walk_where_predicate<'v, V: Visitor<'v>>(
921 predicate: &'v WherePredicate<'v>,
924 WherePredicate::BoundPredicate(WhereBoundPredicate {
927 bound_generic_params,
930 visitor.visit_ty(bounded_ty);
931 walk_list!(visitor, visit_param_bound, bounds);
932 walk_list!(visitor, visit_generic_param, bound_generic_params);
934 WherePredicate::RegionPredicate(WhereRegionPredicate { ref lifetime, bounds, .. }) => {
935 visitor.visit_lifetime(lifetime);
936 walk_list!(visitor, visit_param_bound, bounds);
938 WherePredicate::EqPredicate(WhereEqPredicate {
939 hir_id, ref lhs_ty, ref rhs_ty, ..
941 visitor.visit_id(hir_id);
942 visitor.visit_ty(lhs_ty);
943 visitor.visit_ty(rhs_ty);
948 pub fn walk_fn_ret_ty<'v, V: Visitor<'v>>(visitor: &mut V, ret_ty: &'v FnRetTy<'v>) {
949 if let FnRetTy::Return(ref output_ty) = *ret_ty {
950 visitor.visit_ty(output_ty)
954 pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &'v FnDecl<'v>) {
955 for ty in function_declaration.inputs {
958 walk_fn_ret_ty(visitor, &function_declaration.output)
961 pub fn walk_fn_kind<'v, V: Visitor<'v>>(visitor: &mut V, function_kind: FnKind<'v>) {
962 match function_kind {
963 FnKind::ItemFn(_, generics, ..) => {
964 visitor.visit_generics(generics);
966 FnKind::Method(..) | FnKind::Closure => {}
970 pub fn walk_fn<'v, V: Visitor<'v>>(
972 function_kind: FnKind<'v>,
973 function_declaration: &'v FnDecl<'v>,
978 visitor.visit_id(id);
979 visitor.visit_fn_decl(function_declaration);
980 walk_fn_kind(visitor, function_kind);
981 visitor.visit_nested_body(body_id)
984 pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem<'v>) {
985 visitor.visit_ident(trait_item.ident);
986 visitor.visit_generics(&trait_item.generics);
987 match trait_item.kind {
988 TraitItemKind::Const(ref ty, default) => {
989 visitor.visit_id(trait_item.hir_id());
990 visitor.visit_ty(ty);
991 walk_list!(visitor, visit_nested_body, default);
993 TraitItemKind::Fn(ref sig, TraitFn::Required(param_names)) => {
994 visitor.visit_id(trait_item.hir_id());
995 visitor.visit_fn_decl(&sig.decl);
996 for ¶m_name in param_names {
997 visitor.visit_ident(param_name);
1000 TraitItemKind::Fn(ref sig, TraitFn::Provided(body_id)) => {
1002 FnKind::Method(trait_item.ident, sig, None),
1006 trait_item.hir_id(),
1009 TraitItemKind::Type(bounds, ref default) => {
1010 visitor.visit_id(trait_item.hir_id());
1011 walk_list!(visitor, visit_param_bound, bounds);
1012 walk_list!(visitor, visit_ty, default);
1017 pub fn walk_trait_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, trait_item_ref: &'v TraitItemRef) {
1018 // N.B., deliberately force a compilation error if/when new fields are added.
1019 let TraitItemRef { id, ident, ref kind, span: _, ref defaultness } = *trait_item_ref;
1020 visitor.visit_nested_trait_item(id);
1021 visitor.visit_ident(ident);
1022 visitor.visit_associated_item_kind(kind);
1023 visitor.visit_defaultness(defaultness);
1026 pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem<'v>) {
1027 // N.B., deliberately force a compilation error if/when new fields are added.
1028 let ImplItem { def_id: _, ident, ref vis, ref generics, ref kind, span: _ } = *impl_item;
1030 visitor.visit_ident(ident);
1031 visitor.visit_vis(vis);
1032 visitor.visit_generics(generics);
1034 ImplItemKind::Const(ref ty, body) => {
1035 visitor.visit_id(impl_item.hir_id());
1036 visitor.visit_ty(ty);
1037 visitor.visit_nested_body(body);
1039 ImplItemKind::Fn(ref sig, body_id) => {
1041 FnKind::Method(impl_item.ident, sig, Some(&impl_item.vis)),
1048 ImplItemKind::TyAlias(ref ty) => {
1049 visitor.visit_id(impl_item.hir_id());
1050 visitor.visit_ty(ty);
1055 pub fn walk_foreign_item_ref<'v, V: Visitor<'v>>(
1057 foreign_item_ref: &'v ForeignItemRef,
1059 // N.B., deliberately force a compilation error if/when new fields are added.
1060 let ForeignItemRef { id, ident, span: _ } = *foreign_item_ref;
1061 visitor.visit_nested_foreign_item(id);
1062 visitor.visit_ident(ident);
1065 pub fn walk_impl_item_ref<'v, V: Visitor<'v>>(visitor: &mut V, impl_item_ref: &'v ImplItemRef) {
1066 // N.B., deliberately force a compilation error if/when new fields are added.
1067 let ImplItemRef { id, ident, ref kind, span: _, ref defaultness, trait_item_def_id: _ } =
1069 visitor.visit_nested_impl_item(id);
1070 visitor.visit_ident(ident);
1071 visitor.visit_associated_item_kind(kind);
1072 visitor.visit_defaultness(defaultness);
1075 pub fn walk_struct_def<'v, V: Visitor<'v>>(
1077 struct_definition: &'v VariantData<'v>,
1079 walk_list!(visitor, visit_id, struct_definition.ctor_hir_id());
1080 walk_list!(visitor, visit_field_def, struct_definition.fields());
1083 pub fn walk_field_def<'v, V: Visitor<'v>>(visitor: &mut V, field: &'v FieldDef<'v>) {
1084 visitor.visit_id(field.hir_id);
1085 visitor.visit_vis(&field.vis);
1086 visitor.visit_ident(field.ident);
1087 visitor.visit_ty(&field.ty);
1090 pub fn walk_block<'v, V: Visitor<'v>>(visitor: &mut V, block: &'v Block<'v>) {
1091 visitor.visit_id(block.hir_id);
1092 walk_list!(visitor, visit_stmt, block.stmts);
1093 walk_list!(visitor, visit_expr, &block.expr);
1096 pub fn walk_stmt<'v, V: Visitor<'v>>(visitor: &mut V, statement: &'v Stmt<'v>) {
1097 visitor.visit_id(statement.hir_id);
1098 match statement.kind {
1099 StmtKind::Local(ref local) => visitor.visit_local(local),
1100 StmtKind::Item(item) => visitor.visit_nested_item(item),
1101 StmtKind::Expr(ref expression) | StmtKind::Semi(ref expression) => {
1102 visitor.visit_expr(expression)
1107 pub fn walk_array_len<'v, V: Visitor<'v>>(visitor: &mut V, len: &'v ArrayLen) {
1109 &ArrayLen::Infer(hir_id, _span) => visitor.visit_id(hir_id),
1110 ArrayLen::Body(c) => visitor.visit_anon_const(c),
1114 pub fn walk_anon_const<'v, V: Visitor<'v>>(visitor: &mut V, constant: &'v AnonConst) {
1115 visitor.visit_id(constant.hir_id);
1116 visitor.visit_nested_body(constant.body);
1119 pub fn walk_let_expr<'v, V: Visitor<'v>>(visitor: &mut V, let_expr: &'v Let<'v>) {
1120 // match the visit order in walk_local
1121 visitor.visit_expr(let_expr.init);
1122 visitor.visit_id(let_expr.hir_id);
1123 visitor.visit_pat(let_expr.pat);
1124 walk_list!(visitor, visit_ty, let_expr.ty);
1127 pub fn walk_expr<'v, V: Visitor<'v>>(visitor: &mut V, expression: &'v Expr<'v>) {
1128 visitor.visit_id(expression.hir_id);
1129 match expression.kind {
1130 ExprKind::Box(ref subexpression) => visitor.visit_expr(subexpression),
1131 ExprKind::Array(subexpressions) => {
1132 walk_list!(visitor, visit_expr, subexpressions);
1134 ExprKind::ConstBlock(ref anon_const) => visitor.visit_anon_const(anon_const),
1135 ExprKind::Repeat(ref element, ref count) => {
1136 visitor.visit_expr(element);
1137 visitor.visit_array_length(count)
1139 ExprKind::Struct(ref qpath, fields, ref optional_base) => {
1140 visitor.visit_qpath(qpath, expression.hir_id, expression.span);
1141 for field in fields {
1142 visitor.visit_id(field.hir_id);
1143 visitor.visit_ident(field.ident);
1144 visitor.visit_expr(&field.expr)
1146 walk_list!(visitor, visit_expr, optional_base);
1148 ExprKind::Tup(subexpressions) => {
1149 walk_list!(visitor, visit_expr, subexpressions);
1151 ExprKind::Call(ref callee_expression, arguments) => {
1152 visitor.visit_expr(callee_expression);
1153 walk_list!(visitor, visit_expr, arguments);
1155 ExprKind::MethodCall(ref segment, arguments, _) => {
1156 visitor.visit_path_segment(expression.span, segment);
1157 walk_list!(visitor, visit_expr, arguments);
1159 ExprKind::Binary(_, ref left_expression, ref right_expression) => {
1160 visitor.visit_expr(left_expression);
1161 visitor.visit_expr(right_expression)
1163 ExprKind::AddrOf(_, _, ref subexpression) | ExprKind::Unary(_, ref subexpression) => {
1164 visitor.visit_expr(subexpression)
1166 ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => {
1167 visitor.visit_expr(subexpression);
1168 visitor.visit_ty(typ)
1170 ExprKind::DropTemps(ref subexpression) => {
1171 visitor.visit_expr(subexpression);
1173 ExprKind::Let(ref let_expr) => visitor.visit_let_expr(let_expr),
1174 ExprKind::If(ref cond, ref then, ref else_opt) => {
1175 visitor.visit_expr(cond);
1176 visitor.visit_expr(then);
1177 walk_list!(visitor, visit_expr, else_opt);
1179 ExprKind::Loop(ref block, ref opt_label, _, _) => {
1180 walk_list!(visitor, visit_label, opt_label);
1181 visitor.visit_block(block);
1183 ExprKind::Match(ref subexpression, arms, _) => {
1184 visitor.visit_expr(subexpression);
1185 walk_list!(visitor, visit_arm, arms);
1187 ExprKind::Closure(_, ref function_declaration, body, _fn_decl_span, _gen) => visitor
1190 function_declaration,
1195 ExprKind::Block(ref block, ref opt_label) => {
1196 walk_list!(visitor, visit_label, opt_label);
1197 visitor.visit_block(block);
1199 ExprKind::Assign(ref lhs, ref rhs, _) => {
1200 visitor.visit_expr(rhs);
1201 visitor.visit_expr(lhs)
1203 ExprKind::AssignOp(_, ref left_expression, ref right_expression) => {
1204 visitor.visit_expr(right_expression);
1205 visitor.visit_expr(left_expression);
1207 ExprKind::Field(ref subexpression, ident) => {
1208 visitor.visit_expr(subexpression);
1209 visitor.visit_ident(ident);
1211 ExprKind::Index(ref main_expression, ref index_expression) => {
1212 visitor.visit_expr(main_expression);
1213 visitor.visit_expr(index_expression)
1215 ExprKind::Path(ref qpath) => {
1216 visitor.visit_qpath(qpath, expression.hir_id, expression.span);
1218 ExprKind::Break(ref destination, ref opt_expr) => {
1219 walk_list!(visitor, visit_label, &destination.label);
1220 walk_list!(visitor, visit_expr, opt_expr);
1222 ExprKind::Continue(ref destination) => {
1223 walk_list!(visitor, visit_label, &destination.label);
1225 ExprKind::Ret(ref optional_expression) => {
1226 walk_list!(visitor, visit_expr, optional_expression);
1228 ExprKind::InlineAsm(ref asm) => {
1229 visitor.visit_inline_asm(asm, expression.hir_id);
1231 ExprKind::Yield(ref subexpression, _) => {
1232 visitor.visit_expr(subexpression);
1234 ExprKind::Lit(_) | ExprKind::Err => {}
1238 pub fn walk_arm<'v, V: Visitor<'v>>(visitor: &mut V, arm: &'v Arm<'v>) {
1239 visitor.visit_id(arm.hir_id);
1240 visitor.visit_pat(&arm.pat);
1241 if let Some(ref g) = arm.guard {
1243 Guard::If(ref e) => visitor.visit_expr(e),
1244 Guard::IfLet(ref pat, ref e) => {
1245 visitor.visit_pat(pat);
1246 visitor.visit_expr(e);
1250 visitor.visit_expr(&arm.body);
1253 pub fn walk_vis<'v, V: Visitor<'v>>(visitor: &mut V, vis: &'v Visibility<'v>) {
1254 if let VisibilityKind::Restricted { ref path, hir_id } = vis.node {
1255 visitor.visit_id(hir_id);
1256 visitor.visit_path(path, hir_id)
1260 pub fn walk_associated_item_kind<'v, V: Visitor<'v>>(_: &mut V, _: &'v AssocItemKind) {
1261 // No visitable content here: this fn exists so you can call it if
1262 // the right thing to do, should content be added in the future,
1263 // would be to walk it.
1266 pub fn walk_defaultness<'v, V: Visitor<'v>>(_: &mut V, _: &'v Defaultness) {
1267 // No visitable content here: this fn exists so you can call it if
1268 // the right thing to do, should content be added in the future,
1269 // would be to walk it.