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, Symbol};
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_name(&mut self, _span: Span, _name: Symbol) {
115 fn visit_ident(&mut self, ident: Ident) {
116 walk_ident(self, ident);
118 fn visit_foreign_item(&mut self, i: &'ast ForeignItem) {
119 walk_foreign_item(self, i)
121 fn visit_item(&mut self, i: &'ast Item) {
124 fn visit_local(&mut self, l: &'ast Local) {
127 fn visit_block(&mut self, b: &'ast Block) {
130 fn visit_stmt(&mut self, s: &'ast Stmt) {
133 fn visit_param(&mut self, param: &'ast Param) {
134 walk_param(self, param)
136 fn visit_arm(&mut self, a: &'ast Arm) {
139 fn visit_pat(&mut self, p: &'ast Pat) {
142 fn visit_anon_const(&mut self, c: &'ast AnonConst) {
143 walk_anon_const(self, c)
145 fn visit_expr(&mut self, ex: &'ast Expr) {
148 fn visit_expr_post(&mut self, _ex: &'ast Expr) {}
149 fn visit_ty(&mut self, t: &'ast Ty) {
152 fn visit_generic_param(&mut self, param: &'ast GenericParam) {
153 walk_generic_param(self, param)
155 fn visit_generics(&mut self, g: &'ast Generics) {
156 walk_generics(self, g)
158 fn visit_closure_binder(&mut self, b: &'ast ClosureBinder) {
159 walk_closure_binder(self, b)
161 fn visit_where_predicate(&mut self, p: &'ast WherePredicate) {
162 walk_where_predicate(self, p)
164 fn visit_fn(&mut self, fk: FnKind<'ast>, s: Span, _: NodeId) {
167 fn visit_assoc_item(&mut self, i: &'ast AssocItem, ctxt: AssocCtxt) {
168 walk_assoc_item(self, i, ctxt)
170 fn visit_trait_ref(&mut self, t: &'ast TraitRef) {
171 walk_trait_ref(self, t)
173 fn visit_param_bound(&mut self, bounds: &'ast GenericBound, _ctxt: BoundKind) {
174 walk_param_bound(self, bounds)
176 fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef, m: &'ast TraitBoundModifier) {
177 walk_poly_trait_ref(self, t, m)
179 fn visit_variant_data(&mut self, s: &'ast VariantData) {
180 walk_struct_def(self, s)
182 fn visit_field_def(&mut self, s: &'ast FieldDef) {
183 walk_field_def(self, s)
187 enum_definition: &'ast EnumDef,
188 generics: &'ast Generics,
192 walk_enum_def(self, enum_definition, generics, item_id)
194 fn visit_variant(&mut self, v: &'ast Variant) {
195 walk_variant(self, v)
197 fn visit_label(&mut self, label: &'ast Label) {
198 walk_label(self, label)
200 fn visit_lifetime(&mut self, lifetime: &'ast Lifetime, _: LifetimeCtxt) {
201 walk_lifetime(self, lifetime)
203 fn visit_mac_call(&mut self, mac: &'ast MacCall) {
206 fn visit_mac_def(&mut self, _mac: &'ast MacroDef, _id: NodeId) {
209 fn visit_path(&mut self, path: &'ast Path, _id: NodeId) {
210 walk_path(self, path)
212 fn visit_use_tree(&mut self, use_tree: &'ast UseTree, id: NodeId, _nested: bool) {
213 walk_use_tree(self, use_tree, id)
215 fn visit_path_segment(&mut self, path_span: Span, path_segment: &'ast PathSegment) {
216 walk_path_segment(self, path_span, path_segment)
218 fn visit_generic_args(&mut self, path_span: Span, generic_args: &'ast GenericArgs) {
219 walk_generic_args(self, path_span, generic_args)
221 fn visit_generic_arg(&mut self, generic_arg: &'ast GenericArg) {
222 walk_generic_arg(self, generic_arg)
224 fn visit_assoc_constraint(&mut self, constraint: &'ast AssocConstraint) {
225 walk_assoc_constraint(self, constraint)
227 fn visit_attribute(&mut self, attr: &'ast Attribute) {
228 walk_attribute(self, attr)
230 fn visit_vis(&mut self, vis: &'ast Visibility) {
233 fn visit_fn_ret_ty(&mut self, ret_ty: &'ast FnRetTy) {
234 walk_fn_ret_ty(self, ret_ty)
236 fn visit_fn_header(&mut self, _header: &'ast FnHeader) {
239 fn visit_expr_field(&mut self, f: &'ast ExprField) {
240 walk_expr_field(self, f)
242 fn visit_pat_field(&mut self, fp: &'ast PatField) {
243 walk_pat_field(self, fp)
245 fn visit_crate(&mut self, krate: &'ast Crate) {
246 walk_crate(self, krate)
248 fn visit_inline_asm(&mut self, asm: &'ast InlineAsm) {
249 walk_inline_asm(self, asm)
251 fn visit_inline_asm_sym(&mut self, sym: &'ast InlineAsmSym) {
252 walk_inline_asm_sym(self, sym)
257 macro_rules! walk_list {
258 ($visitor: expr, $method: ident, $list: expr) => {
260 $visitor.$method(elem)
263 ($visitor: expr, $method: ident, $list: expr, $($extra_args: expr),*) => {
265 $visitor.$method(elem, $($extra_args,)*)
270 pub fn walk_ident<'a, V: Visitor<'a>>(visitor: &mut V, ident: Ident) {
271 visitor.visit_name(ident.span, ident.name);
274 pub fn walk_crate<'a, V: Visitor<'a>>(visitor: &mut V, krate: &'a Crate) {
275 walk_list!(visitor, visit_item, &krate.items);
276 walk_list!(visitor, visit_attribute, &krate.attrs);
279 pub fn walk_local<'a, V: Visitor<'a>>(visitor: &mut V, local: &'a Local) {
280 for attr in local.attrs.iter() {
281 visitor.visit_attribute(attr);
283 visitor.visit_pat(&local.pat);
284 walk_list!(visitor, visit_ty, &local.ty);
285 if let Some((init, els)) = local.kind.init_else_opt() {
286 visitor.visit_expr(init);
287 walk_list!(visitor, visit_block, els);
291 pub fn walk_label<'a, V: Visitor<'a>>(visitor: &mut V, label: &'a Label) {
292 visitor.visit_ident(label.ident);
295 pub fn walk_lifetime<'a, V: Visitor<'a>>(visitor: &mut V, lifetime: &'a Lifetime) {
296 visitor.visit_ident(lifetime.ident);
299 pub fn walk_poly_trait_ref<'a, V>(
301 trait_ref: &'a PolyTraitRef,
302 _: &TraitBoundModifier,
306 walk_list!(visitor, visit_generic_param, &trait_ref.bound_generic_params);
307 visitor.visit_trait_ref(&trait_ref.trait_ref);
310 pub fn walk_trait_ref<'a, V: Visitor<'a>>(visitor: &mut V, trait_ref: &'a TraitRef) {
311 visitor.visit_path(&trait_ref.path, trait_ref.ref_id)
314 pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
315 visitor.visit_vis(&item.vis);
316 visitor.visit_ident(item.ident);
318 ItemKind::ExternCrate(orig_name) => {
319 if let Some(orig_name) = orig_name {
320 visitor.visit_name(item.span, orig_name);
323 ItemKind::Use(ref use_tree) => visitor.visit_use_tree(use_tree, item.id, false),
324 ItemKind::Static(ref typ, _, ref expr) | ItemKind::Const(_, ref typ, ref expr) => {
325 visitor.visit_ty(typ);
326 walk_list!(visitor, visit_expr, expr);
328 ItemKind::Fn(box Fn { defaultness: _, ref generics, ref sig, ref body }) => {
330 FnKind::Fn(FnCtxt::Free, item.ident, sig, &item.vis, generics, body.as_deref());
331 visitor.visit_fn(kind, item.span, item.id)
333 ItemKind::Mod(_unsafety, ref mod_kind) => match mod_kind {
334 ModKind::Loaded(items, _inline, _inner_span) => {
335 walk_list!(visitor, visit_item, items)
337 ModKind::Unloaded => {}
339 ItemKind::ForeignMod(ref foreign_module) => {
340 walk_list!(visitor, visit_foreign_item, &foreign_module.items);
342 ItemKind::GlobalAsm(ref asm) => visitor.visit_inline_asm(asm),
343 ItemKind::TyAlias(box TyAlias { ref generics, ref bounds, ref ty, .. }) => {
344 visitor.visit_generics(generics);
345 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
346 walk_list!(visitor, visit_ty, ty);
348 ItemKind::Enum(ref enum_definition, ref generics) => {
349 visitor.visit_generics(generics);
350 visitor.visit_enum_def(enum_definition, generics, item.id, item.span)
352 ItemKind::Impl(box Impl {
362 visitor.visit_generics(generics);
363 walk_list!(visitor, visit_trait_ref, of_trait);
364 visitor.visit_ty(self_ty);
365 walk_list!(visitor, visit_assoc_item, items, AssocCtxt::Impl);
367 ItemKind::Struct(ref struct_definition, ref generics)
368 | ItemKind::Union(ref struct_definition, ref generics) => {
369 visitor.visit_generics(generics);
370 visitor.visit_variant_data(struct_definition);
372 ItemKind::Trait(box Trait {
379 visitor.visit_generics(generics);
380 walk_list!(visitor, visit_param_bound, bounds, BoundKind::SuperTraits);
381 walk_list!(visitor, visit_assoc_item, items, AssocCtxt::Trait);
383 ItemKind::TraitAlias(ref generics, ref bounds) => {
384 visitor.visit_generics(generics);
385 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
387 ItemKind::MacCall(ref mac) => visitor.visit_mac_call(mac),
388 ItemKind::MacroDef(ref ts) => visitor.visit_mac_def(ts, item.id),
390 walk_list!(visitor, visit_attribute, &item.attrs);
393 pub fn walk_enum_def<'a, V: Visitor<'a>>(
395 enum_definition: &'a EnumDef,
399 walk_list!(visitor, visit_variant, &enum_definition.variants);
402 pub fn walk_variant<'a, V: Visitor<'a>>(visitor: &mut V, variant: &'a Variant)
406 visitor.visit_ident(variant.ident);
407 visitor.visit_vis(&variant.vis);
408 visitor.visit_variant_data(&variant.data);
409 walk_list!(visitor, visit_anon_const, &variant.disr_expr);
410 walk_list!(visitor, visit_attribute, &variant.attrs);
413 pub fn walk_expr_field<'a, V: Visitor<'a>>(visitor: &mut V, f: &'a ExprField) {
414 visitor.visit_expr(&f.expr);
415 visitor.visit_ident(f.ident);
416 walk_list!(visitor, visit_attribute, f.attrs.iter());
419 pub fn walk_pat_field<'a, V: Visitor<'a>>(visitor: &mut V, fp: &'a PatField) {
420 visitor.visit_ident(fp.ident);
421 visitor.visit_pat(&fp.pat);
422 walk_list!(visitor, visit_attribute, fp.attrs.iter());
425 pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) {
427 TyKind::Slice(ref ty) | TyKind::Paren(ref ty) => visitor.visit_ty(ty),
428 TyKind::Ptr(ref mutable_type) => visitor.visit_ty(&mutable_type.ty),
429 TyKind::Rptr(ref opt_lifetime, ref mutable_type) => {
430 walk_list!(visitor, visit_lifetime, opt_lifetime, LifetimeCtxt::Rptr);
431 visitor.visit_ty(&mutable_type.ty)
433 TyKind::Tup(ref tuple_element_types) => {
434 walk_list!(visitor, visit_ty, tuple_element_types);
436 TyKind::BareFn(ref function_declaration) => {
437 walk_list!(visitor, visit_generic_param, &function_declaration.generic_params);
438 walk_fn_decl(visitor, &function_declaration.decl);
440 TyKind::Path(ref maybe_qself, ref path) => {
441 if let Some(ref qself) = *maybe_qself {
442 visitor.visit_ty(&qself.ty);
444 visitor.visit_path(path, typ.id);
446 TyKind::Array(ref ty, ref length) => {
447 visitor.visit_ty(ty);
448 visitor.visit_anon_const(length)
450 TyKind::TraitObject(ref bounds, ..) => {
451 walk_list!(visitor, visit_param_bound, bounds, BoundKind::TraitObject);
453 TyKind::ImplTrait(_, ref bounds) => {
454 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Impl);
456 TyKind::Typeof(ref expression) => visitor.visit_anon_const(expression),
457 TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => {}
458 TyKind::MacCall(ref mac) => visitor.visit_mac_call(mac),
459 TyKind::Never | TyKind::CVarArgs => {}
463 pub fn walk_path<'a, V: Visitor<'a>>(visitor: &mut V, path: &'a Path) {
464 for segment in &path.segments {
465 visitor.visit_path_segment(path.span, segment);
469 pub fn walk_use_tree<'a, V: Visitor<'a>>(visitor: &mut V, use_tree: &'a UseTree, id: NodeId) {
470 visitor.visit_path(&use_tree.prefix, id);
471 match use_tree.kind {
472 UseTreeKind::Simple(rename, ..) => {
473 // The extra IDs are handled during HIR lowering.
474 if let Some(rename) = rename {
475 visitor.visit_ident(rename);
478 UseTreeKind::Glob => {}
479 UseTreeKind::Nested(ref use_trees) => {
480 for &(ref nested_tree, nested_id) in use_trees {
481 visitor.visit_use_tree(nested_tree, nested_id, true);
487 pub fn walk_path_segment<'a, V: Visitor<'a>>(
490 segment: &'a PathSegment,
492 visitor.visit_ident(segment.ident);
493 if let Some(ref args) = segment.args {
494 visitor.visit_generic_args(path_span, args);
498 pub fn walk_generic_args<'a, V>(visitor: &mut V, _path_span: Span, generic_args: &'a GenericArgs)
502 match *generic_args {
503 GenericArgs::AngleBracketed(ref data) => {
504 for arg in &data.args {
506 AngleBracketedArg::Arg(a) => visitor.visit_generic_arg(a),
507 AngleBracketedArg::Constraint(c) => visitor.visit_assoc_constraint(c),
511 GenericArgs::Parenthesized(ref data) => {
512 walk_list!(visitor, visit_ty, &data.inputs);
513 walk_fn_ret_ty(visitor, &data.output);
518 pub fn walk_generic_arg<'a, V>(visitor: &mut V, generic_arg: &'a GenericArg)
523 GenericArg::Lifetime(lt) => visitor.visit_lifetime(lt, LifetimeCtxt::GenericArg),
524 GenericArg::Type(ty) => visitor.visit_ty(ty),
525 GenericArg::Const(ct) => visitor.visit_anon_const(ct),
529 pub fn walk_assoc_constraint<'a, V: Visitor<'a>>(visitor: &mut V, constraint: &'a AssocConstraint) {
530 visitor.visit_ident(constraint.ident);
531 if let Some(ref gen_args) = constraint.gen_args {
532 visitor.visit_generic_args(gen_args.span(), gen_args);
534 match constraint.kind {
535 AssocConstraintKind::Equality { ref term } => match term {
536 Term::Ty(ty) => visitor.visit_ty(ty),
537 Term::Const(c) => visitor.visit_anon_const(c),
539 AssocConstraintKind::Bound { ref bounds } => {
540 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
545 pub fn walk_pat<'a, V: Visitor<'a>>(visitor: &mut V, pattern: &'a Pat) {
547 PatKind::TupleStruct(ref opt_qself, ref path, ref elems) => {
548 if let Some(ref qself) = *opt_qself {
549 visitor.visit_ty(&qself.ty);
551 visitor.visit_path(path, pattern.id);
552 walk_list!(visitor, visit_pat, elems);
554 PatKind::Path(ref opt_qself, ref path) => {
555 if let Some(ref qself) = *opt_qself {
556 visitor.visit_ty(&qself.ty);
558 visitor.visit_path(path, pattern.id)
560 PatKind::Struct(ref opt_qself, ref path, ref fields, _) => {
561 if let Some(ref qself) = *opt_qself {
562 visitor.visit_ty(&qself.ty);
564 visitor.visit_path(path, pattern.id);
565 walk_list!(visitor, visit_pat_field, fields);
567 PatKind::Box(ref subpattern)
568 | PatKind::Ref(ref subpattern, _)
569 | PatKind::Paren(ref subpattern) => visitor.visit_pat(subpattern),
570 PatKind::Ident(_, ident, ref optional_subpattern) => {
571 visitor.visit_ident(ident);
572 walk_list!(visitor, visit_pat, optional_subpattern);
574 PatKind::Lit(ref expression) => visitor.visit_expr(expression),
575 PatKind::Range(ref lower_bound, ref upper_bound, _) => {
576 walk_list!(visitor, visit_expr, lower_bound);
577 walk_list!(visitor, visit_expr, upper_bound);
579 PatKind::Wild | PatKind::Rest => {}
580 PatKind::Tuple(ref elems) | PatKind::Slice(ref elems) | PatKind::Or(ref elems) => {
581 walk_list!(visitor, visit_pat, elems);
583 PatKind::MacCall(ref mac) => visitor.visit_mac_call(mac),
587 pub fn walk_foreign_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a ForeignItem) {
588 let Item { id, span, ident, ref vis, ref attrs, ref kind, tokens: _ } = *item;
589 visitor.visit_vis(vis);
590 visitor.visit_ident(ident);
591 walk_list!(visitor, visit_attribute, attrs);
593 ForeignItemKind::Static(ty, _, expr) => {
594 visitor.visit_ty(ty);
595 walk_list!(visitor, visit_expr, expr);
597 ForeignItemKind::Fn(box Fn { defaultness: _, ref generics, ref sig, ref body }) => {
598 let kind = FnKind::Fn(FnCtxt::Foreign, ident, sig, vis, generics, body.as_deref());
599 visitor.visit_fn(kind, span, id);
601 ForeignItemKind::TyAlias(box TyAlias { generics, bounds, ty, .. }) => {
602 visitor.visit_generics(generics);
603 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
604 walk_list!(visitor, visit_ty, ty);
606 ForeignItemKind::MacCall(mac) => {
607 visitor.visit_mac_call(mac);
612 pub fn walk_param_bound<'a, V: Visitor<'a>>(visitor: &mut V, bound: &'a GenericBound) {
614 GenericBound::Trait(ref typ, ref modifier) => visitor.visit_poly_trait_ref(typ, modifier),
615 GenericBound::Outlives(ref lifetime) => {
616 visitor.visit_lifetime(lifetime, LifetimeCtxt::Bound)
621 pub fn walk_generic_param<'a, V: Visitor<'a>>(visitor: &mut V, param: &'a GenericParam) {
622 visitor.visit_ident(param.ident);
623 walk_list!(visitor, visit_attribute, param.attrs.iter());
624 walk_list!(visitor, visit_param_bound, ¶m.bounds, BoundKind::Bound);
626 GenericParamKind::Lifetime => (),
627 GenericParamKind::Type { ref default } => walk_list!(visitor, visit_ty, default),
628 GenericParamKind::Const { ref ty, ref default, .. } => {
629 visitor.visit_ty(ty);
630 if let Some(default) = default {
631 visitor.visit_anon_const(default);
637 pub fn walk_generics<'a, V: Visitor<'a>>(visitor: &mut V, generics: &'a Generics) {
638 walk_list!(visitor, visit_generic_param, &generics.params);
639 walk_list!(visitor, visit_where_predicate, &generics.where_clause.predicates);
642 pub fn walk_closure_binder<'a, V: Visitor<'a>>(visitor: &mut V, binder: &'a ClosureBinder) {
644 ClosureBinder::NotPresent => {}
645 ClosureBinder::For { generic_params, span: _ } => {
646 walk_list!(visitor, visit_generic_param, generic_params)
651 pub fn walk_where_predicate<'a, V: Visitor<'a>>(visitor: &mut V, predicate: &'a WherePredicate) {
653 WherePredicate::BoundPredicate(WhereBoundPredicate {
656 ref bound_generic_params,
659 visitor.visit_ty(bounded_ty);
660 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
661 walk_list!(visitor, visit_generic_param, bound_generic_params);
663 WherePredicate::RegionPredicate(WhereRegionPredicate {
664 ref lifetime, ref bounds, ..
666 visitor.visit_lifetime(lifetime, LifetimeCtxt::Bound);
667 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
669 WherePredicate::EqPredicate(WhereEqPredicate { ref lhs_ty, ref rhs_ty, .. }) => {
670 visitor.visit_ty(lhs_ty);
671 visitor.visit_ty(rhs_ty);
676 pub fn walk_fn_ret_ty<'a, V: Visitor<'a>>(visitor: &mut V, ret_ty: &'a FnRetTy) {
677 if let FnRetTy::Ty(ref output_ty) = *ret_ty {
678 visitor.visit_ty(output_ty)
682 pub fn walk_fn_decl<'a, V: Visitor<'a>>(visitor: &mut V, function_declaration: &'a FnDecl) {
683 for param in &function_declaration.inputs {
684 visitor.visit_param(param);
686 visitor.visit_fn_ret_ty(&function_declaration.output);
689 pub fn walk_fn<'a, V: Visitor<'a>>(visitor: &mut V, kind: FnKind<'a>, _span: Span) {
691 FnKind::Fn(_, _, sig, _, generics, body) => {
692 visitor.visit_generics(generics);
693 visitor.visit_fn_header(&sig.header);
694 walk_fn_decl(visitor, &sig.decl);
695 walk_list!(visitor, visit_block, body);
697 FnKind::Closure(binder, decl, body) => {
698 visitor.visit_closure_binder(binder);
699 walk_fn_decl(visitor, decl);
700 visitor.visit_expr(body);
705 pub fn walk_assoc_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a AssocItem, ctxt: AssocCtxt) {
706 let Item { id, span, ident, ref vis, ref attrs, ref kind, tokens: _ } = *item;
707 visitor.visit_vis(vis);
708 visitor.visit_ident(ident);
709 walk_list!(visitor, visit_attribute, attrs);
711 AssocItemKind::Const(_, ty, expr) => {
712 visitor.visit_ty(ty);
713 walk_list!(visitor, visit_expr, expr);
715 AssocItemKind::Fn(box Fn { defaultness: _, ref generics, ref sig, ref body }) => {
716 let kind = FnKind::Fn(FnCtxt::Assoc(ctxt), ident, sig, vis, generics, body.as_deref());
717 visitor.visit_fn(kind, span, id);
719 AssocItemKind::TyAlias(box TyAlias { generics, bounds, ty, .. }) => {
720 visitor.visit_generics(generics);
721 walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
722 walk_list!(visitor, visit_ty, ty);
724 AssocItemKind::MacCall(mac) => {
725 visitor.visit_mac_call(mac);
730 pub fn walk_struct_def<'a, V: Visitor<'a>>(visitor: &mut V, struct_definition: &'a VariantData) {
731 walk_list!(visitor, visit_field_def, struct_definition.fields());
734 pub fn walk_field_def<'a, V: Visitor<'a>>(visitor: &mut V, field: &'a FieldDef) {
735 visitor.visit_vis(&field.vis);
736 if let Some(ident) = field.ident {
737 visitor.visit_ident(ident);
739 visitor.visit_ty(&field.ty);
740 walk_list!(visitor, visit_attribute, &field.attrs);
743 pub fn walk_block<'a, V: Visitor<'a>>(visitor: &mut V, block: &'a Block) {
744 walk_list!(visitor, visit_stmt, &block.stmts);
747 pub fn walk_stmt<'a, V: Visitor<'a>>(visitor: &mut V, statement: &'a Stmt) {
748 match statement.kind {
749 StmtKind::Local(ref local) => visitor.visit_local(local),
750 StmtKind::Item(ref item) => visitor.visit_item(item),
751 StmtKind::Expr(ref expr) | StmtKind::Semi(ref expr) => visitor.visit_expr(expr),
752 StmtKind::Empty => {}
753 StmtKind::MacCall(ref mac) => {
754 let MacCallStmt { ref mac, style: _, ref attrs, tokens: _ } = **mac;
755 visitor.visit_mac_call(mac);
756 for attr in attrs.iter() {
757 visitor.visit_attribute(attr);
763 pub fn walk_mac<'a, V: Visitor<'a>>(visitor: &mut V, mac: &'a MacCall) {
764 visitor.visit_path(&mac.path, DUMMY_NODE_ID);
767 pub fn walk_anon_const<'a, V: Visitor<'a>>(visitor: &mut V, constant: &'a AnonConst) {
768 visitor.visit_expr(&constant.value);
771 pub fn walk_inline_asm<'a, V: Visitor<'a>>(visitor: &mut V, asm: &'a InlineAsm) {
772 for (op, _) in &asm.operands {
774 InlineAsmOperand::In { expr, .. }
775 | InlineAsmOperand::Out { expr: Some(expr), .. }
776 | InlineAsmOperand::InOut { expr, .. } => visitor.visit_expr(expr),
777 InlineAsmOperand::Out { expr: None, .. } => {}
778 InlineAsmOperand::SplitInOut { in_expr, out_expr, .. } => {
779 visitor.visit_expr(in_expr);
780 if let Some(out_expr) = out_expr {
781 visitor.visit_expr(out_expr);
784 InlineAsmOperand::Const { anon_const, .. } => visitor.visit_anon_const(anon_const),
785 InlineAsmOperand::Sym { sym } => visitor.visit_inline_asm_sym(sym),
790 pub fn walk_inline_asm_sym<'a, V: Visitor<'a>>(visitor: &mut V, sym: &'a InlineAsmSym) {
791 if let Some(ref qself) = sym.qself {
792 visitor.visit_ty(&qself.ty);
794 visitor.visit_path(&sym.path, sym.id);
797 pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
798 walk_list!(visitor, visit_attribute, expression.attrs.iter());
800 match expression.kind {
801 ExprKind::Box(ref subexpression) => visitor.visit_expr(subexpression),
802 ExprKind::Array(ref subexpressions) => {
803 walk_list!(visitor, visit_expr, subexpressions);
805 ExprKind::ConstBlock(ref anon_const) => visitor.visit_anon_const(anon_const),
806 ExprKind::Repeat(ref element, ref count) => {
807 visitor.visit_expr(element);
808 visitor.visit_anon_const(count)
810 ExprKind::Struct(ref se) => {
811 if let Some(ref qself) = se.qself {
812 visitor.visit_ty(&qself.ty);
814 visitor.visit_path(&se.path, expression.id);
815 walk_list!(visitor, visit_expr_field, &se.fields);
817 StructRest::Base(expr) => visitor.visit_expr(expr),
818 StructRest::Rest(_span) => {}
819 StructRest::None => {}
822 ExprKind::Tup(ref subexpressions) => {
823 walk_list!(visitor, visit_expr, subexpressions);
825 ExprKind::Call(ref callee_expression, ref arguments) => {
826 visitor.visit_expr(callee_expression);
827 walk_list!(visitor, visit_expr, arguments);
829 ExprKind::MethodCall(ref segment, ref arguments, _span) => {
830 visitor.visit_path_segment(expression.span, segment);
831 walk_list!(visitor, visit_expr, arguments);
833 ExprKind::Binary(_, ref left_expression, ref right_expression) => {
834 visitor.visit_expr(left_expression);
835 visitor.visit_expr(right_expression)
837 ExprKind::AddrOf(_, _, ref subexpression) | ExprKind::Unary(_, ref subexpression) => {
838 visitor.visit_expr(subexpression)
840 ExprKind::Cast(ref subexpression, ref typ) | ExprKind::Type(ref subexpression, ref typ) => {
841 visitor.visit_expr(subexpression);
842 visitor.visit_ty(typ)
844 ExprKind::Let(ref pat, ref expr, _) => {
845 visitor.visit_pat(pat);
846 visitor.visit_expr(expr);
848 ExprKind::If(ref head_expression, ref if_block, ref optional_else) => {
849 visitor.visit_expr(head_expression);
850 visitor.visit_block(if_block);
851 walk_list!(visitor, visit_expr, optional_else);
853 ExprKind::While(ref subexpression, ref block, ref opt_label) => {
854 walk_list!(visitor, visit_label, opt_label);
855 visitor.visit_expr(subexpression);
856 visitor.visit_block(block);
858 ExprKind::ForLoop(ref pattern, ref subexpression, ref block, ref opt_label) => {
859 walk_list!(visitor, visit_label, opt_label);
860 visitor.visit_pat(pattern);
861 visitor.visit_expr(subexpression);
862 visitor.visit_block(block);
864 ExprKind::Loop(ref block, ref opt_label) => {
865 walk_list!(visitor, visit_label, opt_label);
866 visitor.visit_block(block);
868 ExprKind::Match(ref subexpression, ref arms) => {
869 visitor.visit_expr(subexpression);
870 walk_list!(visitor, visit_arm, arms);
872 ExprKind::Closure(ref binder, _, _, _, ref decl, ref body, _decl_span) => {
873 visitor.visit_fn(FnKind::Closure(binder, decl, body), expression.span, expression.id)
875 ExprKind::Block(ref block, ref opt_label) => {
876 walk_list!(visitor, visit_label, opt_label);
877 visitor.visit_block(block);
879 ExprKind::Async(_, _, ref body) => {
880 visitor.visit_block(body);
882 ExprKind::Await(ref expr) => visitor.visit_expr(expr),
883 ExprKind::Assign(ref lhs, ref rhs, _) => {
884 visitor.visit_expr(lhs);
885 visitor.visit_expr(rhs);
887 ExprKind::AssignOp(_, ref left_expression, ref right_expression) => {
888 visitor.visit_expr(left_expression);
889 visitor.visit_expr(right_expression);
891 ExprKind::Field(ref subexpression, ident) => {
892 visitor.visit_expr(subexpression);
893 visitor.visit_ident(ident);
895 ExprKind::Index(ref main_expression, ref index_expression) => {
896 visitor.visit_expr(main_expression);
897 visitor.visit_expr(index_expression)
899 ExprKind::Range(ref start, ref end, _) => {
900 walk_list!(visitor, visit_expr, start);
901 walk_list!(visitor, visit_expr, end);
903 ExprKind::Underscore => {}
904 ExprKind::Path(ref maybe_qself, ref path) => {
905 if let Some(ref qself) = *maybe_qself {
906 visitor.visit_ty(&qself.ty);
908 visitor.visit_path(path, expression.id)
910 ExprKind::Break(ref opt_label, ref opt_expr) => {
911 walk_list!(visitor, visit_label, opt_label);
912 walk_list!(visitor, visit_expr, opt_expr);
914 ExprKind::Continue(ref opt_label) => {
915 walk_list!(visitor, visit_label, opt_label);
917 ExprKind::Ret(ref optional_expression) => {
918 walk_list!(visitor, visit_expr, optional_expression);
920 ExprKind::Yeet(ref optional_expression) => {
921 walk_list!(visitor, visit_expr, optional_expression);
923 ExprKind::MacCall(ref mac) => visitor.visit_mac_call(mac),
924 ExprKind::Paren(ref subexpression) => visitor.visit_expr(subexpression),
925 ExprKind::InlineAsm(ref asm) => visitor.visit_inline_asm(asm),
926 ExprKind::Yield(ref optional_expression) => {
927 walk_list!(visitor, visit_expr, optional_expression);
929 ExprKind::Try(ref subexpression) => visitor.visit_expr(subexpression),
930 ExprKind::TryBlock(ref body) => visitor.visit_block(body),
931 ExprKind::Lit(_) | ExprKind::Err => {}
934 visitor.visit_expr_post(expression)
937 pub fn walk_param<'a, V: Visitor<'a>>(visitor: &mut V, param: &'a Param) {
938 walk_list!(visitor, visit_attribute, param.attrs.iter());
939 visitor.visit_pat(¶m.pat);
940 visitor.visit_ty(¶m.ty);
943 pub fn walk_arm<'a, V: Visitor<'a>>(visitor: &mut V, arm: &'a Arm) {
944 visitor.visit_pat(&arm.pat);
945 walk_list!(visitor, visit_expr, &arm.guard);
946 visitor.visit_expr(&arm.body);
947 walk_list!(visitor, visit_attribute, &arm.attrs);
950 pub fn walk_vis<'a, V: Visitor<'a>>(visitor: &mut V, vis: &'a Visibility) {
951 if let VisibilityKind::Restricted { ref path, id } = vis.kind {
952 visitor.visit_path(path, id);
956 pub fn walk_attribute<'a, V: Visitor<'a>>(visitor: &mut V, attr: &'a Attribute) {
958 AttrKind::Normal(ref item, ref _tokens) => walk_mac_args(visitor, &item.args),
959 AttrKind::DocComment(..) => {}
963 pub fn walk_mac_args<'a, V: Visitor<'a>>(visitor: &mut V, args: &'a MacArgs) {
966 MacArgs::Delimited(_dspan, _delim, _tokens) => {}
967 MacArgs::Eq(_eq_span, MacArgsEq::Ast(expr)) => visitor.visit_expr(expr),
968 MacArgs::Eq(_, MacArgsEq::Hir(lit)) => {
969 unreachable!("in literal form when walking mac args eq: {:?}", lit)