1 //! AST walker. Each overridden visit method has full control over what
2 //! happens with its node, it can do its own traversal of the node's children,
3 //! call `visit::walk_*` to apply the default traversal algorithm, or prevent
4 //! deeper traversal by doing nothing.
6 //! Note: it is an important invariant that the default visitor walks the body
7 //! of a function in "execution order" (more concretely, reverse post-order
8 //! with respect to the CFG implied by the AST), meaning that if AST node A may
9 //! execute before AST node B, then A is visited first. The borrow checker in
10 //! particular relies on this property.
12 //! Note: walking an AST before macro expansion is probably a bad idea. For
13 //! instance, a walker looking for item names in a module will miss all of
14 //! those that are created by the expansion of a macro.
18 use rustc_span::symbol::Ident;
21 #[derive(Copy, Clone, Debug, PartialEq)]
27 #[derive(Copy, Clone, Debug, PartialEq)]
34 #[derive(Copy, Clone, Debug)]
36 /// Trait bounds in generics bounds and type/trait alias.
37 /// E.g., `<T: Bound>`, `type A: Bound`, or `where T: Bound`.
40 /// Trait bounds in `impl` type.
41 /// E.g., `type Foo = impl Bound1 + Bound2 + Bound3`.
44 /// Trait bounds in trait object type.
45 /// E.g., `dyn Bound1 + Bound2 + Bound3`.
48 /// Super traits of a trait.
49 /// E.g., `trait A: B`
53 #[derive(Copy, Clone, Debug)]
55 /// E.g., `fn foo()`, `fn foo(&self)`, or `extern "Abi" fn foo()`.
56 Fn(FnCtxt, Ident, &'a FnSig, &'a Visibility, &'a Generics, Option<&'a Block>),
58 /// E.g., `|x, y| body`.
59 Closure(&'a ClosureBinder, &'a FnDecl, &'a Expr),
63 pub fn header(&self) -> Option<&'a FnHeader> {
65 FnKind::Fn(_, _, sig, _, _, _) => Some(&sig.header),
66 FnKind::Closure(_, _, _) => None,
70 pub fn ident(&self) -> Option<&Ident> {
72 FnKind::Fn(_, ident, ..) => Some(ident),
77 pub fn decl(&self) -> &'a FnDecl {
79 FnKind::Fn(_, _, sig, _, _, _) => &sig.decl,
80 FnKind::Closure(_, decl, _) => decl,
84 pub fn ctxt(&self) -> Option<FnCtxt> {
86 FnKind::Fn(ctxt, ..) => Some(*ctxt),
87 FnKind::Closure(..) => None,
92 #[derive(Copy, Clone, Debug)]
93 pub enum LifetimeCtxt {
94 /// Appears in a reference type.
96 /// Appears as a bound on a type or another lifetime.
98 /// Appears as a generic argument.
102 /// Each method of the `Visitor` trait is a hook to be potentially
103 /// overridden. Each method's default implementation recursively visits
104 /// the substructure of the input via the corresponding `walk` method;
105 /// e.g., the `visit_item` method by default calls `visit::walk_item`.
107 /// If you want to ensure that your code handles every variant
108 /// explicitly, you need to override each method. (And you also need
109 /// to monitor future changes to `Visitor` in case a new method with a
110 /// new default implementation gets introduced.)
111 pub trait Visitor<'ast>: Sized {
112 fn visit_ident(&mut self, _ident: Ident) {}
113 fn visit_foreign_item(&mut self, i: &'ast ForeignItem) {
114 walk_foreign_item(self, i)
116 fn visit_item(&mut self, i: &'ast Item) {
119 fn visit_local(&mut self, l: &'ast Local) {
122 fn visit_block(&mut self, b: &'ast Block) {
125 fn visit_stmt(&mut self, s: &'ast Stmt) {
128 fn visit_param(&mut self, param: &'ast Param) {
129 walk_param(self, param)
131 fn visit_arm(&mut self, a: &'ast Arm) {
134 fn visit_pat(&mut self, p: &'ast Pat) {
137 fn visit_anon_const(&mut self, c: &'ast AnonConst) {
138 walk_anon_const(self, c)
140 fn visit_expr(&mut self, ex: &'ast Expr) {
143 fn visit_expr_post(&mut self, _ex: &'ast Expr) {}
144 fn visit_ty(&mut self, t: &'ast Ty) {
147 fn visit_generic_param(&mut self, param: &'ast GenericParam) {
148 walk_generic_param(self, param)
150 fn visit_generics(&mut self, g: &'ast Generics) {
151 walk_generics(self, g)
153 fn visit_closure_binder(&mut self, b: &'ast ClosureBinder) {
154 walk_closure_binder(self, b)
156 fn visit_where_predicate(&mut self, p: &'ast WherePredicate) {
157 walk_where_predicate(self, p)
159 fn visit_fn(&mut self, fk: FnKind<'ast>, s: Span, _: NodeId) {
162 fn visit_assoc_item(&mut self, i: &'ast AssocItem, ctxt: AssocCtxt) {
163 walk_assoc_item(self, i, ctxt)
165 fn visit_trait_ref(&mut self, t: &'ast TraitRef) {
166 walk_trait_ref(self, t)
168 fn visit_param_bound(&mut self, bounds: &'ast GenericBound, _ctxt: BoundKind) {
169 walk_param_bound(self, bounds)
171 fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef) {
172 walk_poly_trait_ref(self, t)
174 fn visit_variant_data(&mut self, s: &'ast VariantData) {
175 walk_struct_def(self, s)
177 fn visit_field_def(&mut self, s: &'ast FieldDef) {
178 walk_field_def(self, s)
180 fn visit_enum_def(&mut self, enum_definition: &'ast EnumDef) {
181 walk_enum_def(self, enum_definition)
183 fn visit_variant(&mut self, v: &'ast Variant) {
184 walk_variant(self, v)
186 fn visit_label(&mut self, label: &'ast Label) {
187 walk_label(self, label)
189 fn visit_lifetime(&mut self, lifetime: &'ast Lifetime, _: LifetimeCtxt) {
190 walk_lifetime(self, lifetime)
192 fn visit_mac_call(&mut self, mac: &'ast MacCall) {
195 fn visit_mac_def(&mut self, _mac: &'ast MacroDef, _id: NodeId) {
198 fn visit_path(&mut self, path: &'ast Path, _id: NodeId) {
199 walk_path(self, path)
201 fn visit_use_tree(&mut self, use_tree: &'ast UseTree, id: NodeId, _nested: bool) {
202 walk_use_tree(self, use_tree, id)
204 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'ast PathSegment) {
205 walk_path_segment(self, path_span, path_segment)
207 fn visit_generic_args(&mut self, path_span: Span, generic_args: &'ast GenericArgs) {
208 walk_generic_args(self, path_span, generic_args)
210 fn visit_generic_arg(&mut self, generic_arg: &'ast GenericArg) {
211 walk_generic_arg(self, generic_arg)
213 fn visit_assoc_constraint(&mut self, constraint: &'ast AssocConstraint) {
214 walk_assoc_constraint(self, constraint)
216 fn visit_attribute(&mut self, attr: &'ast Attribute) {
217 walk_attribute(self, attr)
219 fn visit_vis(&mut self, vis: &'ast Visibility) {
222 fn visit_fn_ret_ty(&mut self, ret_ty: &'ast FnRetTy) {
223 walk_fn_ret_ty(self, ret_ty)
225 fn visit_fn_header(&mut self, _header: &'ast FnHeader) {
228 fn visit_expr_field(&mut self, f: &'ast ExprField) {
229 walk_expr_field(self, f)
231 fn visit_pat_field(&mut self, fp: &'ast PatField) {
232 walk_pat_field(self, fp)
234 fn visit_crate(&mut self, krate: &'ast Crate) {
235 walk_crate(self, krate)
237 fn visit_inline_asm(&mut self, asm: &'ast InlineAsm) {
238 walk_inline_asm(self, asm)
240 fn visit_inline_asm_sym(&mut self, sym: &'ast InlineAsmSym) {
241 walk_inline_asm_sym(self, sym)
246 macro_rules! walk_list {
247 ($visitor: expr, $method: ident, $list: expr) => {
249 $visitor.$method(elem)
252 ($visitor: expr, $method: ident, $list: expr, $($extra_args: expr),*) => {
254 $visitor.$method(elem, $($extra_args,)*)
259 pub fn walk_crate<'a, V: Visitor<'a>>(visitor: &mut V, krate: &'a Crate) {
260 walk_list!(visitor, visit_item, &krate.items);
261 walk_list!(visitor, visit_attribute, &krate.attrs);
264 pub fn walk_local<'a, V: Visitor<'a>>(visitor: &mut V, local: &'a Local) {
265 for attr in local.attrs.iter() {
266 visitor.visit_attribute(attr);
268 visitor.visit_pat(&local.pat);
269 walk_list!(visitor, visit_ty, &local.ty);
270 if let Some((init, els)) = local.kind.init_else_opt() {
271 visitor.visit_expr(init);
272 walk_list!(visitor, visit_block, els);
276 pub fn walk_label<'a, V: Visitor<'a>>(visitor: &mut V, label: &'a Label) {
277 visitor.visit_ident(label.ident);
280 pub fn walk_lifetime<'a, V: Visitor<'a>>(visitor: &mut V, lifetime: &'a Lifetime) {
281 visitor.visit_ident(lifetime.ident);
284 pub fn walk_poly_trait_ref<'a, V>(visitor: &mut V, trait_ref: &'a PolyTraitRef)
288 walk_list!(visitor, visit_generic_param, &trait_ref.bound_generic_params);
289 visitor.visit_trait_ref(&trait_ref.trait_ref);
292 pub fn walk_trait_ref<'a, V: Visitor<'a>>(visitor: &mut V, trait_ref: &'a TraitRef) {
293 visitor.visit_path(&trait_ref.path, trait_ref.ref_id)
296 pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
297 visitor.visit_vis(&item.vis);
298 visitor.visit_ident(item.ident);
300 ItemKind::ExternCrate(_) => {}
301 ItemKind::Use(ref use_tree) => visitor.visit_use_tree(use_tree, item.id, false),
302 ItemKind::Static(ref typ, _, ref expr) | ItemKind::Const(_, ref typ, ref expr) => {
303 visitor.visit_ty(typ);
304 walk_list!(visitor, visit_expr, expr);
306 ItemKind::Fn(box Fn { defaultness: _, ref generics, ref sig, ref body }) => {
308 FnKind::Fn(FnCtxt::Free, item.ident, sig, &item.vis, generics, body.as_deref());
309 visitor.visit_fn(kind, item.span, item.id)
311 ItemKind::Mod(_unsafety, ref mod_kind) => match mod_kind {
312 ModKind::Loaded(items, _inline, _inner_span) => {
313 walk_list!(visitor, visit_item, items)
315 ModKind::Unloaded => {}
317 ItemKind::ForeignMod(ref foreign_module) => {
318 walk_list!(visitor, visit_foreign_item, &foreign_module.items);
320 ItemKind::GlobalAsm(ref asm) => visitor.visit_inline_asm(asm),
321 ItemKind::TyAlias(box TyAlias { ref generics, ref bounds, ref ty, .. }) => {
322 visitor.visit_generics(generics);
323 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
324 walk_list!(visitor, visit_ty, ty);
326 ItemKind::Enum(ref enum_definition, ref generics) => {
327 visitor.visit_generics(generics);
328 visitor.visit_enum_def(enum_definition)
330 ItemKind::Impl(box Impl {
340 visitor.visit_generics(generics);
341 walk_list!(visitor, visit_trait_ref, of_trait);
342 visitor.visit_ty(self_ty);
343 walk_list!(visitor, visit_assoc_item, items, AssocCtxt::Impl);
345 ItemKind::Struct(ref struct_definition, ref generics)
346 | ItemKind::Union(ref struct_definition, ref generics) => {
347 visitor.visit_generics(generics);
348 visitor.visit_variant_data(struct_definition);
350 ItemKind::Trait(box Trait {
357 visitor.visit_generics(generics);
358 walk_list!(visitor, visit_param_bound, bounds, BoundKind::SuperTraits);
359 walk_list!(visitor, visit_assoc_item, items, AssocCtxt::Trait);
361 ItemKind::TraitAlias(ref generics, ref bounds) => {
362 visitor.visit_generics(generics);
363 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
365 ItemKind::MacCall(ref mac) => visitor.visit_mac_call(mac),
366 ItemKind::MacroDef(ref ts) => visitor.visit_mac_def(ts, item.id),
368 walk_list!(visitor, visit_attribute, &item.attrs);
371 pub fn walk_enum_def<'a, V: Visitor<'a>>(visitor: &mut V, enum_definition: &'a EnumDef) {
372 walk_list!(visitor, visit_variant, &enum_definition.variants);
375 pub fn walk_variant<'a, V: Visitor<'a>>(visitor: &mut V, variant: &'a Variant)
379 visitor.visit_ident(variant.ident);
380 visitor.visit_vis(&variant.vis);
381 visitor.visit_variant_data(&variant.data);
382 walk_list!(visitor, visit_anon_const, &variant.disr_expr);
383 walk_list!(visitor, visit_attribute, &variant.attrs);
386 pub fn walk_expr_field<'a, V: Visitor<'a>>(visitor: &mut V, f: &'a ExprField) {
387 visitor.visit_expr(&f.expr);
388 visitor.visit_ident(f.ident);
389 walk_list!(visitor, visit_attribute, f.attrs.iter());
392 pub fn walk_pat_field<'a, V: Visitor<'a>>(visitor: &mut V, fp: &'a PatField) {
393 visitor.visit_ident(fp.ident);
394 visitor.visit_pat(&fp.pat);
395 walk_list!(visitor, visit_attribute, fp.attrs.iter());
398 pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) {
400 TyKind::Slice(ref ty) | TyKind::Paren(ref ty) => visitor.visit_ty(ty),
401 TyKind::Ptr(ref mutable_type) => visitor.visit_ty(&mutable_type.ty),
402 TyKind::Rptr(ref opt_lifetime, ref mutable_type) => {
403 walk_list!(visitor, visit_lifetime, opt_lifetime, LifetimeCtxt::Rptr);
404 visitor.visit_ty(&mutable_type.ty)
406 TyKind::Tup(ref tuple_element_types) => {
407 walk_list!(visitor, visit_ty, tuple_element_types);
409 TyKind::BareFn(ref function_declaration) => {
410 walk_list!(visitor, visit_generic_param, &function_declaration.generic_params);
411 walk_fn_decl(visitor, &function_declaration.decl);
413 TyKind::Path(ref maybe_qself, ref path) => {
414 if let Some(ref qself) = *maybe_qself {
415 visitor.visit_ty(&qself.ty);
417 visitor.visit_path(path, typ.id);
419 TyKind::Array(ref ty, ref length) => {
420 visitor.visit_ty(ty);
421 visitor.visit_anon_const(length)
423 TyKind::TraitObject(ref bounds, ..) => {
424 walk_list!(visitor, visit_param_bound, bounds, BoundKind::TraitObject);
426 TyKind::ImplTrait(_, ref bounds) => {
427 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Impl);
429 TyKind::Typeof(ref expression) => visitor.visit_anon_const(expression),
430 TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => {}
431 TyKind::MacCall(ref mac) => visitor.visit_mac_call(mac),
432 TyKind::Never | TyKind::CVarArgs => {}
436 pub fn walk_path<'a, V: Visitor<'a>>(visitor: &mut V, path: &'a Path) {
437 for segment in &path.segments {
438 visitor.visit_path_segment(path.span, segment);
442 pub fn walk_use_tree<'a, V: Visitor<'a>>(visitor: &mut V, use_tree: &'a UseTree, id: NodeId) {
443 visitor.visit_path(&use_tree.prefix, id);
444 match use_tree.kind {
445 UseTreeKind::Simple(rename, ..) => {
446 // The extra IDs are handled during HIR lowering.
447 if let Some(rename) = rename {
448 visitor.visit_ident(rename);
451 UseTreeKind::Glob => {}
452 UseTreeKind::Nested(ref use_trees) => {
453 for &(ref nested_tree, nested_id) in use_trees {
454 visitor.visit_use_tree(nested_tree, nested_id, true);
460 pub fn walk_path_segment<'a, V: Visitor<'a>>(
463 segment: &'a PathSegment,
465 visitor.visit_ident(segment.ident);
466 if let Some(ref args) = segment.args {
467 visitor.visit_generic_args(path_span, args);
471 pub fn walk_generic_args<'a, V>(visitor: &mut V, _path_span: Span, generic_args: &'a GenericArgs)
475 match *generic_args {
476 GenericArgs::AngleBracketed(ref data) => {
477 for arg in &data.args {
479 AngleBracketedArg::Arg(a) => visitor.visit_generic_arg(a),
480 AngleBracketedArg::Constraint(c) => visitor.visit_assoc_constraint(c),
484 GenericArgs::Parenthesized(ref data) => {
485 walk_list!(visitor, visit_ty, &data.inputs);
486 walk_fn_ret_ty(visitor, &data.output);
491 pub fn walk_generic_arg<'a, V>(visitor: &mut V, generic_arg: &'a GenericArg)
496 GenericArg::Lifetime(lt) => visitor.visit_lifetime(lt, LifetimeCtxt::GenericArg),
497 GenericArg::Type(ty) => visitor.visit_ty(ty),
498 GenericArg::Const(ct) => visitor.visit_anon_const(ct),
502 pub fn walk_assoc_constraint<'a, V: Visitor<'a>>(visitor: &mut V, constraint: &'a AssocConstraint) {
503 visitor.visit_ident(constraint.ident);
504 if let Some(ref gen_args) = constraint.gen_args {
505 visitor.visit_generic_args(gen_args.span(), gen_args);
507 match constraint.kind {
508 AssocConstraintKind::Equality { ref term } => match term {
509 Term::Ty(ty) => visitor.visit_ty(ty),
510 Term::Const(c) => visitor.visit_anon_const(c),
512 AssocConstraintKind::Bound { ref bounds } => {
513 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
518 pub fn walk_pat<'a, V: Visitor<'a>>(visitor: &mut V, pattern: &'a Pat) {
520 PatKind::TupleStruct(ref opt_qself, ref path, ref elems) => {
521 if let Some(ref qself) = *opt_qself {
522 visitor.visit_ty(&qself.ty);
524 visitor.visit_path(path, pattern.id);
525 walk_list!(visitor, visit_pat, elems);
527 PatKind::Path(ref opt_qself, ref path) => {
528 if let Some(ref qself) = *opt_qself {
529 visitor.visit_ty(&qself.ty);
531 visitor.visit_path(path, pattern.id)
533 PatKind::Struct(ref opt_qself, ref path, ref fields, _) => {
534 if let Some(ref qself) = *opt_qself {
535 visitor.visit_ty(&qself.ty);
537 visitor.visit_path(path, pattern.id);
538 walk_list!(visitor, visit_pat_field, fields);
540 PatKind::Box(ref subpattern)
541 | PatKind::Ref(ref subpattern, _)
542 | PatKind::Paren(ref subpattern) => visitor.visit_pat(subpattern),
543 PatKind::Ident(_, ident, ref optional_subpattern) => {
544 visitor.visit_ident(ident);
545 walk_list!(visitor, visit_pat, optional_subpattern);
547 PatKind::Lit(ref expression) => visitor.visit_expr(expression),
548 PatKind::Range(ref lower_bound, ref upper_bound, _) => {
549 walk_list!(visitor, visit_expr, lower_bound);
550 walk_list!(visitor, visit_expr, upper_bound);
552 PatKind::Wild | PatKind::Rest => {}
553 PatKind::Tuple(ref elems) | PatKind::Slice(ref elems) | PatKind::Or(ref elems) => {
554 walk_list!(visitor, visit_pat, elems);
556 PatKind::MacCall(ref mac) => visitor.visit_mac_call(mac),
560 pub fn walk_foreign_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a ForeignItem) {
561 let Item { id, span, ident, ref vis, ref attrs, ref kind, tokens: _ } = *item;
562 visitor.visit_vis(vis);
563 visitor.visit_ident(ident);
564 walk_list!(visitor, visit_attribute, attrs);
566 ForeignItemKind::Static(ty, _, expr) => {
567 visitor.visit_ty(ty);
568 walk_list!(visitor, visit_expr, expr);
570 ForeignItemKind::Fn(box Fn { defaultness: _, ref generics, ref sig, ref body }) => {
571 let kind = FnKind::Fn(FnCtxt::Foreign, ident, sig, vis, generics, body.as_deref());
572 visitor.visit_fn(kind, span, id);
574 ForeignItemKind::TyAlias(box TyAlias { generics, bounds, ty, .. }) => {
575 visitor.visit_generics(generics);
576 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
577 walk_list!(visitor, visit_ty, ty);
579 ForeignItemKind::MacCall(mac) => {
580 visitor.visit_mac_call(mac);
585 pub fn walk_param_bound<'a, V: Visitor<'a>>(visitor: &mut V, bound: &'a GenericBound) {
587 GenericBound::Trait(ref typ, ref _modifier) => visitor.visit_poly_trait_ref(typ),
588 GenericBound::Outlives(ref lifetime) => {
589 visitor.visit_lifetime(lifetime, LifetimeCtxt::Bound)
594 pub fn walk_generic_param<'a, V: Visitor<'a>>(visitor: &mut V, param: &'a GenericParam) {
595 visitor.visit_ident(param.ident);
596 walk_list!(visitor, visit_attribute, param.attrs.iter());
597 walk_list!(visitor, visit_param_bound, ¶m.bounds, BoundKind::Bound);
599 GenericParamKind::Lifetime => (),
600 GenericParamKind::Type { ref default } => walk_list!(visitor, visit_ty, default),
601 GenericParamKind::Const { ref ty, ref default, .. } => {
602 visitor.visit_ty(ty);
603 if let Some(default) = default {
604 visitor.visit_anon_const(default);
610 pub fn walk_generics<'a, V: Visitor<'a>>(visitor: &mut V, generics: &'a Generics) {
611 walk_list!(visitor, visit_generic_param, &generics.params);
612 walk_list!(visitor, visit_where_predicate, &generics.where_clause.predicates);
615 pub fn walk_closure_binder<'a, V: Visitor<'a>>(visitor: &mut V, binder: &'a ClosureBinder) {
617 ClosureBinder::NotPresent => {}
618 ClosureBinder::For { generic_params, span: _ } => {
619 walk_list!(visitor, visit_generic_param, generic_params)
624 pub fn walk_where_predicate<'a, V: Visitor<'a>>(visitor: &mut V, predicate: &'a WherePredicate) {
626 WherePredicate::BoundPredicate(WhereBoundPredicate {
629 ref bound_generic_params,
632 visitor.visit_ty(bounded_ty);
633 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
634 walk_list!(visitor, visit_generic_param, bound_generic_params);
636 WherePredicate::RegionPredicate(WhereRegionPredicate {
637 ref lifetime, ref bounds, ..
639 visitor.visit_lifetime(lifetime, LifetimeCtxt::Bound);
640 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
642 WherePredicate::EqPredicate(WhereEqPredicate { ref lhs_ty, ref rhs_ty, .. }) => {
643 visitor.visit_ty(lhs_ty);
644 visitor.visit_ty(rhs_ty);
649 pub fn walk_fn_ret_ty<'a, V: Visitor<'a>>(visitor: &mut V, ret_ty: &'a FnRetTy) {
650 if let FnRetTy::Ty(ref output_ty) = *ret_ty {
651 visitor.visit_ty(output_ty)
655 pub fn walk_fn_decl<'a, V: Visitor<'a>>(visitor: &mut V, function_declaration: &'a FnDecl) {
656 for param in &function_declaration.inputs {
657 visitor.visit_param(param);
659 visitor.visit_fn_ret_ty(&function_declaration.output);
662 pub fn walk_fn<'a, V: Visitor<'a>>(visitor: &mut V, kind: FnKind<'a>, _span: Span) {
664 FnKind::Fn(_, _, sig, _, generics, body) => {
665 visitor.visit_generics(generics);
666 visitor.visit_fn_header(&sig.header);
667 walk_fn_decl(visitor, &sig.decl);
668 walk_list!(visitor, visit_block, body);
670 FnKind::Closure(binder, decl, body) => {
671 visitor.visit_closure_binder(binder);
672 walk_fn_decl(visitor, decl);
673 visitor.visit_expr(body);
678 pub fn walk_assoc_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a AssocItem, ctxt: AssocCtxt) {
679 let Item { id, span, ident, ref vis, ref attrs, ref kind, tokens: _ } = *item;
680 visitor.visit_vis(vis);
681 visitor.visit_ident(ident);
682 walk_list!(visitor, visit_attribute, attrs);
684 AssocItemKind::Const(_, ty, expr) => {
685 visitor.visit_ty(ty);
686 walk_list!(visitor, visit_expr, expr);
688 AssocItemKind::Fn(box Fn { defaultness: _, ref generics, ref sig, ref body }) => {
689 let kind = FnKind::Fn(FnCtxt::Assoc(ctxt), ident, sig, vis, generics, body.as_deref());
690 visitor.visit_fn(kind, span, id);
692 AssocItemKind::TyAlias(box TyAlias { generics, bounds, ty, .. }) => {
693 visitor.visit_generics(generics);
694 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
695 walk_list!(visitor, visit_ty, ty);
697 AssocItemKind::MacCall(mac) => {
698 visitor.visit_mac_call(mac);
703 pub fn walk_struct_def<'a, V: Visitor<'a>>(visitor: &mut V, struct_definition: &'a VariantData) {
704 walk_list!(visitor, visit_field_def, struct_definition.fields());
707 pub fn walk_field_def<'a, V: Visitor<'a>>(visitor: &mut V, field: &'a FieldDef) {
708 visitor.visit_vis(&field.vis);
709 if let Some(ident) = field.ident {
710 visitor.visit_ident(ident);
712 visitor.visit_ty(&field.ty);
713 walk_list!(visitor, visit_attribute, &field.attrs);
716 pub fn walk_block<'a, V: Visitor<'a>>(visitor: &mut V, block: &'a Block) {
717 walk_list!(visitor, visit_stmt, &block.stmts);
720 pub fn walk_stmt<'a, V: Visitor<'a>>(visitor: &mut V, statement: &'a Stmt) {
721 match statement.kind {
722 StmtKind::Local(ref local) => visitor.visit_local(local),
723 StmtKind::Item(ref item) => visitor.visit_item(item),
724 StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => visitor.visit_expr(expr),
725 StmtKind::Empty => {}
726 StmtKind::MacCall(ref mac) => {
727 let MacCallStmt { ref mac, style: _, ref attrs, tokens: _ } = **mac;
728 visitor.visit_mac_call(mac);
729 for attr in attrs.iter() {
730 visitor.visit_attribute(attr);
736 pub fn walk_mac<'a, V: Visitor<'a>>(visitor: &mut V, mac: &'a MacCall) {
737 visitor.visit_path(&mac.path, DUMMY_NODE_ID);
740 pub fn walk_anon_const<'a, V: Visitor<'a>>(visitor: &mut V, constant: &'a AnonConst) {
741 visitor.visit_expr(&constant.value);
744 pub fn walk_inline_asm<'a, V: Visitor<'a>>(visitor: &mut V, asm: &'a InlineAsm) {
745 for (op, _) in &asm.operands {
747 InlineAsmOperand::In { expr, .. }
748 | InlineAsmOperand::Out { expr: Some(expr), .. }
749 | InlineAsmOperand::InOut { expr, .. } => visitor.visit_expr(expr),
750 InlineAsmOperand::Out { expr: None, .. } => {}
751 InlineAsmOperand::SplitInOut { in_expr, out_expr, .. } => {
752 visitor.visit_expr(in_expr);
753 if let Some(out_expr) = out_expr {
754 visitor.visit_expr(out_expr);
757 InlineAsmOperand::Const { anon_const, .. } => visitor.visit_anon_const(anon_const),
758 InlineAsmOperand::Sym { sym } => visitor.visit_inline_asm_sym(sym),
763 pub fn walk_inline_asm_sym<'a, V: Visitor<'a>>(visitor: &mut V, sym: &'a InlineAsmSym) {
764 if let Some(ref qself) = sym.qself {
765 visitor.visit_ty(&qself.ty);
767 visitor.visit_path(&sym.path, sym.id);
770 pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
771 walk_list!(visitor, visit_attribute, expression.attrs.iter());
773 match expression.kind {
774 ExprKind::Box(ref subexpression) => visitor.visit_expr(subexpression),
775 ExprKind::Array(ref subexpressions) => {
776 walk_list!(visitor, visit_expr, subexpressions);
778 ExprKind::ConstBlock(ref anon_const) => visitor.visit_anon_const(anon_const),
779 ExprKind::Repeat(ref element, ref count) => {
780 visitor.visit_expr(element);
781 visitor.visit_anon_const(count)
783 ExprKind::Struct(ref se) => {
784 if let Some(ref qself) = se.qself {
785 visitor.visit_ty(&qself.ty);
787 visitor.visit_path(&se.path, expression.id);
788 walk_list!(visitor, visit_expr_field, &se.fields);
790 StructRest::Base(expr) => visitor.visit_expr(expr),
791 StructRest::Rest(_span) => {}
792 StructRest::None => {}
795 ExprKind::Tup(ref subexpressions) => {
796 walk_list!(visitor, visit_expr, subexpressions);
798 ExprKind::Call(ref callee_expression, ref arguments) => {
799 visitor.visit_expr(callee_expression);
800 walk_list!(visitor, visit_expr, arguments);
802 ExprKind::MethodCall(ref segment, ref receiver, ref arguments, _span) => {
803 visitor.visit_path_segment(expression.span, segment);
804 visitor.visit_expr(receiver);
805 walk_list!(visitor, visit_expr, arguments);
807 ExprKind::Binary(_, ref left_expression, ref right_expression) => {
808 visitor.visit_expr(left_expression);
809 visitor.visit_expr(right_expression)
811 ExprKind::AddrOf(_, _, ref subexpression) | ExprKind::Unary(_, ref subexpression) => {
812 visitor.visit_expr(subexpression)
814 ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => {
815 visitor.visit_expr(subexpression);
816 visitor.visit_ty(typ)
818 ExprKind::Let(ref pat, ref expr, _) => {
819 visitor.visit_pat(pat);
820 visitor.visit_expr(expr);
822 ExprKind::If(ref head_expression, ref if_block, ref optional_else) => {
823 visitor.visit_expr(head_expression);
824 visitor.visit_block(if_block);
825 walk_list!(visitor, visit_expr, optional_else);
827 ExprKind::While(ref subexpression, ref block, ref opt_label) => {
828 walk_list!(visitor, visit_label, opt_label);
829 visitor.visit_expr(subexpression);
830 visitor.visit_block(block);
832 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, ref opt_label) => {
833 walk_list!(visitor, visit_label, opt_label);
834 visitor.visit_pat(pattern);
835 visitor.visit_expr(subexpression);
836 visitor.visit_block(block);
838 ExprKind::Loop(ref block, ref opt_label) => {
839 walk_list!(visitor, visit_label, opt_label);
840 visitor.visit_block(block);
842 ExprKind::Match(ref subexpression, ref arms) => {
843 visitor.visit_expr(subexpression);
844 walk_list!(visitor, visit_arm, arms);
846 ExprKind::Closure(ref binder, _, _, _, ref decl, ref body, _decl_span) => {
847 visitor.visit_fn(FnKind::Closure(binder, decl, body), expression.span, expression.id)
849 ExprKind::Block(ref block, ref opt_label) => {
850 walk_list!(visitor, visit_label, opt_label);
851 visitor.visit_block(block);
853 ExprKind::Async(_, _, ref body) => {
854 visitor.visit_block(body);
856 ExprKind::Await(ref expr) => visitor.visit_expr(expr),
857 ExprKind::Assign(ref lhs, ref rhs, _) => {
858 visitor.visit_expr(lhs);
859 visitor.visit_expr(rhs);
861 ExprKind::AssignOp(_, ref left_expression, ref right_expression) => {
862 visitor.visit_expr(left_expression);
863 visitor.visit_expr(right_expression);
865 ExprKind::Field(ref subexpression, ident) => {
866 visitor.visit_expr(subexpression);
867 visitor.visit_ident(ident);
869 ExprKind::Index(ref main_expression, ref index_expression) => {
870 visitor.visit_expr(main_expression);
871 visitor.visit_expr(index_expression)
873 ExprKind::Range(ref start, ref end, _) => {
874 walk_list!(visitor, visit_expr, start);
875 walk_list!(visitor, visit_expr, end);
877 ExprKind::Underscore => {}
878 ExprKind::Path(ref maybe_qself, ref path) => {
879 if let Some(ref qself) = *maybe_qself {
880 visitor.visit_ty(&qself.ty);
882 visitor.visit_path(path, expression.id)
884 ExprKind::Break(ref opt_label, ref opt_expr) => {
885 walk_list!(visitor, visit_label, opt_label);
886 walk_list!(visitor, visit_expr, opt_expr);
888 ExprKind::Continue(ref opt_label) => {
889 walk_list!(visitor, visit_label, opt_label);
891 ExprKind::Ret(ref optional_expression) => {
892 walk_list!(visitor, visit_expr, optional_expression);
894 ExprKind::Yeet(ref optional_expression) => {
895 walk_list!(visitor, visit_expr, optional_expression);
897 ExprKind::MacCall(ref mac) => visitor.visit_mac_call(mac),
898 ExprKind::Paren(ref subexpression) => visitor.visit_expr(subexpression),
899 ExprKind::InlineAsm(ref asm) => visitor.visit_inline_asm(asm),
900 ExprKind::Yield(ref optional_expression) => {
901 walk_list!(visitor, visit_expr, optional_expression);
903 ExprKind::Try(ref subexpression) => visitor.visit_expr(subexpression),
904 ExprKind::TryBlock(ref body) => visitor.visit_block(body),
905 ExprKind::Lit(_) | ExprKind::Err => {}
908 visitor.visit_expr_post(expression)
911 pub fn walk_param<'a, V: Visitor<'a>>(visitor: &mut V, param: &'a Param) {
912 walk_list!(visitor, visit_attribute, param.attrs.iter());
913 visitor.visit_pat(¶m.pat);
914 visitor.visit_ty(¶m.ty);
917 pub fn walk_arm<'a, V: Visitor<'a>>(visitor: &mut V, arm: &'a Arm) {
918 visitor.visit_pat(&arm.pat);
919 walk_list!(visitor, visit_expr, &arm.guard);
920 visitor.visit_expr(&arm.body);
921 walk_list!(visitor, visit_attribute, &arm.attrs);
924 pub fn walk_vis<'a, V: Visitor<'a>>(visitor: &mut V, vis: &'a Visibility) {
925 if let VisibilityKind::Restricted { ref path, id, shorthand: _ } = vis.kind {
926 visitor.visit_path(path, id);
930 pub fn walk_attribute<'a, V: Visitor<'a>>(visitor: &mut V, attr: &'a Attribute) {
932 AttrKind::Normal(ref normal) => walk_mac_args(visitor, &normal.item.args),
933 AttrKind::DocComment(..) => {}
937 pub fn walk_mac_args<'a, V: Visitor<'a>>(visitor: &mut V, args: &'a MacArgs) {
940 MacArgs::Delimited(_dspan, _delim, _tokens) => {}
941 MacArgs::Eq(_eq_span, MacArgsEq::Ast(expr)) => visitor.visit_expr(expr),
942 MacArgs::Eq(_, MacArgsEq::Hir(lit)) => {
943 unreachable!("in literal form when walking mac args eq: {:?}", lit)