rustc_ast/
visit.rs

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.
5//!
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.
11//!
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.
15
16pub use rustc_ast_ir::visit::VisitorResult;
17pub use rustc_ast_ir::{try_visit, visit_opt, walk_list, walk_visitable_list};
18use rustc_span::{Ident, Span};
19use thin_vec::ThinVec;
20
21use crate::ast::*;
22use crate::ptr::P;
23
24#[derive(Copy, Clone, Debug, PartialEq)]
25pub enum AssocCtxt {
26    Trait,
27    Impl { of_trait: bool },
28}
29
30#[derive(Copy, Clone, Debug, PartialEq)]
31pub enum FnCtxt {
32    Free,
33    Foreign,
34    Assoc(AssocCtxt),
35}
36
37#[derive(Copy, Clone, Debug)]
38pub enum BoundKind {
39    /// Trait bounds in generics bounds and type/trait alias.
40    /// E.g., `<T: Bound>`, `type A: Bound`, or `where T: Bound`.
41    Bound,
42
43    /// Trait bounds in `impl` type.
44    /// E.g., `type Foo = impl Bound1 + Bound2 + Bound3`.
45    Impl,
46
47    /// Trait bounds in trait object type.
48    /// E.g., `dyn Bound1 + Bound2 + Bound3`.
49    TraitObject,
50
51    /// Super traits of a trait.
52    /// E.g., `trait A: B`
53    SuperTraits,
54}
55impl BoundKind {
56    pub fn descr(self) -> &'static str {
57        match self {
58            BoundKind::Bound => "bounds",
59            BoundKind::Impl => "`impl Trait`",
60            BoundKind::TraitObject => "`dyn` trait object bounds",
61            BoundKind::SuperTraits => "supertrait bounds",
62        }
63    }
64}
65
66#[derive(Copy, Clone, Debug)]
67pub enum FnKind<'a> {
68    /// E.g., `fn foo()`, `fn foo(&self)`, or `extern "Abi" fn foo()`.
69    Fn(FnCtxt, &'a Visibility, &'a Fn),
70
71    /// E.g., `|x, y| body`.
72    Closure(&'a ClosureBinder, &'a Option<CoroutineKind>, &'a FnDecl, &'a Expr),
73}
74
75impl<'a> FnKind<'a> {
76    pub fn header(&self) -> Option<&'a FnHeader> {
77        match *self {
78            FnKind::Fn(_, _, Fn { sig, .. }) => Some(&sig.header),
79            FnKind::Closure(..) => None,
80        }
81    }
82
83    pub fn ident(&self) -> Option<&Ident> {
84        match self {
85            FnKind::Fn(_, _, Fn { ident, .. }) => Some(ident),
86            _ => None,
87        }
88    }
89
90    pub fn decl(&self) -> &'a FnDecl {
91        match self {
92            FnKind::Fn(_, _, Fn { sig, .. }) => &sig.decl,
93            FnKind::Closure(_, _, decl, _) => decl,
94        }
95    }
96
97    pub fn ctxt(&self) -> Option<FnCtxt> {
98        match self {
99            FnKind::Fn(ctxt, ..) => Some(*ctxt),
100            FnKind::Closure(..) => None,
101        }
102    }
103}
104
105#[derive(Copy, Clone, Debug)]
106pub enum LifetimeCtxt {
107    /// Appears in a reference type.
108    Ref,
109    /// Appears as a bound on a type or another lifetime.
110    Bound,
111    /// Appears as a generic argument.
112    GenericArg,
113}
114
115/// Each method of the `Visitor` trait is a hook to be potentially
116/// overridden. Each method's default implementation recursively visits
117/// the substructure of the input via the corresponding `walk` method;
118/// e.g., the `visit_item` method by default calls `visit::walk_item`.
119///
120/// If you want to ensure that your code handles every variant
121/// explicitly, you need to override each method. (And you also need
122/// to monitor future changes to `Visitor` in case a new method with a
123/// new default implementation gets introduced.)
124///
125/// Every `walk_*` method uses deconstruction to access fields of structs and
126/// enums. This will result in a compile error if a field is added, which makes
127/// it more likely the appropriate visit call will be added for it.
128pub trait Visitor<'ast>: Sized {
129    /// The result type of the `visit_*` methods. Can be either `()`,
130    /// or `ControlFlow<T>`.
131    type Result: VisitorResult = ();
132
133    fn visit_ident(&mut self, _ident: &'ast Ident) -> Self::Result {
134        Self::Result::output()
135    }
136    fn visit_foreign_mod(&mut self, nm: &'ast ForeignMod) -> Self::Result {
137        walk_foreign_mod(self, nm)
138    }
139    fn visit_foreign_item(&mut self, i: &'ast ForeignItem) -> Self::Result {
140        walk_item(self, i)
141    }
142    fn visit_item(&mut self, i: &'ast Item) -> Self::Result {
143        walk_item(self, i)
144    }
145    fn visit_local(&mut self, l: &'ast Local) -> Self::Result {
146        walk_local(self, l)
147    }
148    fn visit_block(&mut self, b: &'ast Block) -> Self::Result {
149        walk_block(self, b)
150    }
151    fn visit_stmt(&mut self, s: &'ast Stmt) -> Self::Result {
152        walk_stmt(self, s)
153    }
154    fn visit_param(&mut self, param: &'ast Param) -> Self::Result {
155        walk_param(self, param)
156    }
157    fn visit_arm(&mut self, a: &'ast Arm) -> Self::Result {
158        walk_arm(self, a)
159    }
160    fn visit_pat(&mut self, p: &'ast Pat) -> Self::Result {
161        walk_pat(self, p)
162    }
163    fn visit_anon_const(&mut self, c: &'ast AnonConst) -> Self::Result {
164        walk_anon_const(self, c)
165    }
166    fn visit_expr(&mut self, ex: &'ast Expr) -> Self::Result {
167        walk_expr(self, ex)
168    }
169    /// This method is a hack to workaround unstable of `stmt_expr_attributes`.
170    /// It can be removed once that feature is stabilized.
171    fn visit_method_receiver_expr(&mut self, ex: &'ast Expr) -> Self::Result {
172        self.visit_expr(ex)
173    }
174    fn visit_ty(&mut self, t: &'ast Ty) -> Self::Result {
175        walk_ty(self, t)
176    }
177    fn visit_ty_pat(&mut self, t: &'ast TyPat) -> Self::Result {
178        walk_ty_pat(self, t)
179    }
180    fn visit_generic_param(&mut self, param: &'ast GenericParam) -> Self::Result {
181        walk_generic_param(self, param)
182    }
183    fn visit_generics(&mut self, g: &'ast Generics) -> Self::Result {
184        walk_generics(self, g)
185    }
186    fn visit_closure_binder(&mut self, b: &'ast ClosureBinder) -> Self::Result {
187        walk_closure_binder(self, b)
188    }
189    fn visit_contract(&mut self, c: &'ast FnContract) -> Self::Result {
190        walk_contract(self, c)
191    }
192    fn visit_where_predicate(&mut self, p: &'ast WherePredicate) -> Self::Result {
193        walk_where_predicate(self, p)
194    }
195    fn visit_where_predicate_kind(&mut self, k: &'ast WherePredicateKind) -> Self::Result {
196        walk_where_predicate_kind(self, k)
197    }
198    fn visit_fn(&mut self, fk: FnKind<'ast>, _: Span, _: NodeId) -> Self::Result {
199        walk_fn(self, fk)
200    }
201    fn visit_assoc_item(&mut self, i: &'ast AssocItem, ctxt: AssocCtxt) -> Self::Result {
202        walk_assoc_item(self, i, ctxt)
203    }
204    fn visit_trait_ref(&mut self, t: &'ast TraitRef) -> Self::Result {
205        walk_trait_ref(self, t)
206    }
207    fn visit_param_bound(&mut self, bounds: &'ast GenericBound, _ctxt: BoundKind) -> Self::Result {
208        walk_param_bound(self, bounds)
209    }
210    fn visit_precise_capturing_arg(&mut self, arg: &'ast PreciseCapturingArg) -> Self::Result {
211        walk_precise_capturing_arg(self, arg)
212    }
213    fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef) -> Self::Result {
214        walk_poly_trait_ref(self, t)
215    }
216    fn visit_variant_data(&mut self, s: &'ast VariantData) -> Self::Result {
217        walk_variant_data(self, s)
218    }
219    fn visit_field_def(&mut self, s: &'ast FieldDef) -> Self::Result {
220        walk_field_def(self, s)
221    }
222    fn visit_enum_def(&mut self, enum_definition: &'ast EnumDef) -> Self::Result {
223        walk_enum_def(self, enum_definition)
224    }
225    fn visit_variant(&mut self, v: &'ast Variant) -> Self::Result {
226        walk_variant(self, v)
227    }
228    fn visit_variant_discr(&mut self, discr: &'ast AnonConst) -> Self::Result {
229        self.visit_anon_const(discr)
230    }
231    fn visit_label(&mut self, label: &'ast Label) -> Self::Result {
232        walk_label(self, label)
233    }
234    fn visit_lifetime(&mut self, lifetime: &'ast Lifetime, _: LifetimeCtxt) -> Self::Result {
235        walk_lifetime(self, lifetime)
236    }
237    fn visit_mac_call(&mut self, mac: &'ast MacCall) -> Self::Result {
238        walk_mac(self, mac)
239    }
240    fn visit_id(&mut self, _id: NodeId) -> Self::Result {
241        Self::Result::output()
242    }
243    fn visit_macro_def(&mut self, _mac: &'ast MacroDef) -> Self::Result {
244        Self::Result::output()
245    }
246    fn visit_path(&mut self, path: &'ast Path) -> Self::Result {
247        walk_path(self, path)
248    }
249    fn visit_use_tree(
250        &mut self,
251        use_tree: &'ast UseTree,
252        id: NodeId,
253        _nested: bool,
254    ) -> Self::Result {
255        walk_use_tree(self, use_tree, id)
256    }
257    fn visit_path_segment(&mut self, path_segment: &'ast PathSegment) -> Self::Result {
258        walk_path_segment(self, path_segment)
259    }
260    fn visit_generic_args(&mut self, generic_args: &'ast GenericArgs) -> Self::Result {
261        walk_generic_args(self, generic_args)
262    }
263    fn visit_generic_arg(&mut self, generic_arg: &'ast GenericArg) -> Self::Result {
264        walk_generic_arg(self, generic_arg)
265    }
266    fn visit_assoc_item_constraint(
267        &mut self,
268        constraint: &'ast AssocItemConstraint,
269    ) -> Self::Result {
270        walk_assoc_item_constraint(self, constraint)
271    }
272    fn visit_attribute(&mut self, attr: &'ast Attribute) -> Self::Result {
273        walk_attribute(self, attr)
274    }
275    fn visit_vis(&mut self, vis: &'ast Visibility) -> Self::Result {
276        walk_vis(self, vis)
277    }
278    fn visit_fn_ret_ty(&mut self, ret_ty: &'ast FnRetTy) -> Self::Result {
279        walk_fn_ret_ty(self, ret_ty)
280    }
281    fn visit_fn_header(&mut self, header: &'ast FnHeader) -> Self::Result {
282        walk_fn_header(self, header)
283    }
284    fn visit_expr_field(&mut self, f: &'ast ExprField) -> Self::Result {
285        walk_expr_field(self, f)
286    }
287    fn visit_pat_field(&mut self, fp: &'ast PatField) -> Self::Result {
288        walk_pat_field(self, fp)
289    }
290    fn visit_crate(&mut self, krate: &'ast Crate) -> Self::Result {
291        walk_crate(self, krate)
292    }
293    fn visit_inline_asm(&mut self, asm: &'ast InlineAsm) -> Self::Result {
294        walk_inline_asm(self, asm)
295    }
296    fn visit_format_args(&mut self, fmt: &'ast FormatArgs) -> Self::Result {
297        walk_format_args(self, fmt)
298    }
299    fn visit_inline_asm_sym(&mut self, sym: &'ast InlineAsmSym) -> Self::Result {
300        walk_inline_asm_sym(self, sym)
301    }
302    fn visit_capture_by(&mut self, _capture_by: &'ast CaptureBy) -> Self::Result {
303        Self::Result::output()
304    }
305    fn visit_coroutine_kind(&mut self, coroutine_kind: &'ast CoroutineKind) -> Self::Result {
306        walk_coroutine_kind(self, coroutine_kind)
307    }
308    fn visit_fn_decl(&mut self, fn_decl: &'ast FnDecl) -> Self::Result {
309        walk_fn_decl(self, fn_decl)
310    }
311    fn visit_qself(&mut self, qs: &'ast Option<P<QSelf>>) -> Self::Result {
312        walk_qself(self, qs)
313    }
314}
315
316#[macro_export]
317macro_rules! common_visitor_and_walkers {
318    ($(($mut: ident))? $Visitor:ident$(<$lt:lifetime>)?) => {
319        pub trait WalkItemKind {
320            type Ctxt;
321            fn walk<$($lt,)? V: $Visitor$(<$lt>)?>(
322                &$($lt)? $($mut)? self,
323                span: Span,
324                id: NodeId,
325                visibility: &$($lt)? $($mut)? Visibility,
326                ctxt: Self::Ctxt,
327                visitor: &mut V,
328            ) $(-> <V as Visitor<$lt>>::Result)?;
329        }
330
331        // this is only used by the MutVisitor. We include this symmetry here to make writing other functions easier
332        $(${ignore($lt)}
333            #[expect(unused, rustc::pass_by_value)]
334            #[inline]
335        )?
336        fn visit_span<$($lt,)? V: $Visitor$(<$lt>)?>(visitor: &mut V, span: &$($lt)? $($mut)? Span) $(-> <V as Visitor<$lt>>::Result)? {
337            $(
338                ${ignore($mut)}
339                visitor.visit_span(span);
340            )?
341            $(${ignore($lt)}V::Result::output())?
342        }
343
344        /// helper since `Visitor` wants `NodeId` but `MutVisitor` wants `&mut NodeId`
345        $(${ignore($lt)}
346            #[expect(rustc::pass_by_value)]
347        )?
348        #[inline]
349        fn visit_id<$($lt,)? V: $Visitor$(<$lt>)?>(visitor: &mut V, id: &$($lt)? $($mut)? NodeId) $(-> <V as Visitor<$lt>>::Result)? {
350            // deref `&NodeId` into `NodeId` only for `Visitor`
351            visitor.visit_id( $(${ignore($lt)} * )? id)
352        }
353
354        // this is only used by the MutVisitor. We include this symmetry here to make writing other functions easier
355        fn visit_safety<$($lt,)? V: $Visitor$(<$lt>)?>(vis: &mut V, safety: &$($lt)? $($mut)? Safety) $(-> <V as Visitor<$lt>>::Result)? {
356            match safety {
357                Safety::Unsafe(span) => visit_span(vis, span),
358                Safety::Safe(span) => visit_span(vis, span),
359                Safety::Default => { $(${ignore($lt)}V::Result::output())? }
360            }
361        }
362
363        fn visit_constness<$($lt,)? V: $Visitor$(<$lt>)?>(vis: &mut V, constness: &$($lt)? $($mut)? Const) $(-> <V as Visitor<$lt>>::Result)? {
364            match constness {
365                Const::Yes(span) => visit_span(vis, span),
366                Const::No => {
367                    $(<V as Visitor<$lt>>::Result::output())?
368                }
369            }
370        }
371
372        fn visit_defaultness<$($lt,)? V: $Visitor$(<$lt>)?>(vis: &mut V, defaultness: &$($lt)? $($mut)? Defaultness) $(-> <V as Visitor<$lt>>::Result)? {
373            match defaultness {
374                Defaultness::Default(span) => visit_span(vis, span),
375                Defaultness::Final => {
376                    $(<V as Visitor<$lt>>::Result::output())?
377                }
378            }
379        }
380
381        fn visit_polarity<$($lt,)? V: $Visitor$(<$lt>)?>(vis: &mut V, polarity: &$($lt)? $($mut)? ImplPolarity) $(-> <V as Visitor<$lt>>::Result)? {
382            match polarity {
383                ImplPolarity::Positive => { $(<V as Visitor<$lt>>::Result::output())? }
384                ImplPolarity::Negative(span) => visit_span(vis, span),
385            }
386        }
387
388        fn visit_bounds<$($lt,)? V: $Visitor$(<$lt>)?>(visitor: &mut V, bounds: &$($lt)? $($mut)? GenericBounds, ctxt: BoundKind) $(-> <V as Visitor<$lt>>::Result)? {
389            walk_list!(visitor, visit_param_bound, bounds, ctxt);
390            $(<V as Visitor<$lt>>::Result::output())?
391        }
392
393        pub fn walk_label<$($lt,)? V: $Visitor$(<$lt>)?>(visitor: &mut V, Label { ident }: &$($lt)? $($mut)? Label) $(-> <V as Visitor<$lt>>::Result)? {
394            visitor.visit_ident(ident)
395        }
396
397        pub fn walk_fn_header<$($lt,)? V: $Visitor$(<$lt>)?>(visitor: &mut V, header: &$($lt)? $($mut)? FnHeader) $(-> <V as Visitor<$lt>>::Result)? {
398            let FnHeader { safety, coroutine_kind, constness, ext: _ } = header;
399            try_visit!(visit_constness(visitor, constness));
400            visit_opt!(visitor, visit_coroutine_kind, coroutine_kind);
401            visit_safety(visitor, safety)
402        }
403
404        pub fn walk_lifetime<$($lt,)? V: $Visitor$(<$lt>)?>(visitor: &mut V, Lifetime { id, ident }: &$($lt)? $($mut)? Lifetime) $(-> <V as Visitor<$lt>>::Result)? {
405            try_visit!(visit_id(visitor, id));
406            visitor.visit_ident(ident)
407        }
408
409        fn walk_item_ctxt<$($lt,)? V: $Visitor$(<$lt>)?, K: WalkItemKind>(
410            visitor: &mut V,
411            item: &$($mut)? $($lt)? Item<K>,
412            ctxt: K::Ctxt,
413        ) $(-> <V as Visitor<$lt>>::Result)? {
414            let Item { attrs, id, kind, vis, span, tokens: _ } = item;
415            try_visit!(visit_id(visitor, id));
416            walk_list!(visitor, visit_attribute, attrs);
417            try_visit!(visitor.visit_vis(vis));
418            try_visit!(kind.walk(*span, *id, vis, ctxt, visitor));
419            visit_span(visitor, span)
420        }
421
422        pub fn walk_item<$($lt,)? V: $Visitor$(<$lt>)?, K: WalkItemKind<Ctxt = ()>>(
423            visitor: &mut V,
424            item: &$($mut)? $($lt)? Item<K>,
425        ) $(-> <V as Visitor<$lt>>::Result)? {
426            walk_item_ctxt(visitor, item, ())
427        }
428
429        pub fn walk_assoc_item<$($lt,)? V: $Visitor$(<$lt>)?>(
430            visitor: &mut V,
431            item: &$($mut)? $($lt)? AssocItem,
432            ctxt: AssocCtxt,
433        ) $(-> <V as Visitor<$lt>>::Result)? {
434            walk_item_ctxt(visitor, item, ctxt)
435        }
436
437        impl WalkItemKind for ItemKind {
438            type Ctxt = ();
439            fn walk<$($lt,)? V: $Visitor$(<$lt>)?>(
440                &$($lt)? $($mut)? self,
441                span: Span,
442                id: NodeId,
443                visibility: &$($lt)? $($mut)? Visibility,
444                _ctxt: Self::Ctxt,
445                vis: &mut V,
446            ) $(-> <V as Visitor<$lt>>::Result)? {
447                match self {
448                    ItemKind::ExternCrate(_orig_name, ident) => vis.visit_ident(ident),
449                    // FIXME(fee1-dead): look into this weird assymetry
450                    ItemKind::Use(use_tree) => vis.visit_use_tree(use_tree$(${ignore($lt)}, id, false)?),
451                    ItemKind::Static(box StaticItem {
452                        ident,
453                        ty,
454                        safety: _,
455                        mutability: _,
456                        expr,
457                        define_opaque,
458                    }) => {
459                        try_visit!(vis.visit_ident(ident));
460                        try_visit!(vis.visit_ty(ty));
461                        visit_opt!(vis, visit_expr, expr);
462                        walk_define_opaques(vis, define_opaque)
463                    }
464                    ItemKind::Const(item) => {
465                        walk_const_item(vis, item)
466                    }
467                    ItemKind::Fn(func) => {
468                        let kind = FnKind::Fn(FnCtxt::Free, visibility, &$($mut)? *func);
469                        vis.visit_fn(kind, span, id)
470                    }
471                    ItemKind::Mod(safety, ident, mod_kind) => {
472                        try_visit!(visit_safety(vis, safety));
473                        try_visit!(vis.visit_ident(ident));
474                        match mod_kind {
475                            ModKind::Loaded(
476                                items,
477                                _inline,
478                                ModSpans { inner_span, inject_use_span },
479                                _,
480                            ) => {
481                                $(${ignore($mut)}
482                                    items.flat_map_in_place(|item| vis.flat_map_item(item));
483                                )?
484                                $(${ignore($lt)}
485                                    walk_list!(vis, visit_item, items);
486                                )?
487                                try_visit!(visit_span(vis, inner_span));
488                                try_visit!(visit_span(vis, inject_use_span));
489                            }
490                            ModKind::Unloaded => {}
491                        }
492                        $(<V as Visitor<$lt>>::Result::output())?
493                    }
494                    ItemKind::ForeignMod(nm) => vis.visit_foreign_mod(nm),
495                    ItemKind::GlobalAsm(asm) => vis.visit_inline_asm(asm),
496                    ItemKind::TyAlias(box TyAlias {
497                        defaultness,
498                        ident,
499                        generics,
500                        $(${ignore($lt)} #[expect(unused)])?
501                        where_clauses,
502                        bounds,
503                        ty,
504                    }) => {
505                        try_visit!(visit_defaultness(vis, defaultness));
506                        try_visit!(vis.visit_ident(ident));
507                        try_visit!(vis.visit_generics(generics));
508                        try_visit!(visit_bounds(vis, bounds, BoundKind::Bound));
509                        visit_opt!(vis, visit_ty, ty);
510                        $(${ignore($mut)}
511                            walk_ty_alias_where_clauses(vis, where_clauses);
512                        )?
513                        $(<V as Visitor<$lt>>::Result::output())?
514                    }
515                    ItemKind::Enum(ident, generics, enum_definition) => {
516                        try_visit!(vis.visit_ident(ident));
517                        try_visit!(vis.visit_generics(generics));
518                        $(${ignore($mut)}
519                            enum_definition.variants.flat_map_in_place(|variant| vis.flat_map_variant(variant));
520                        )?
521                        $(${ignore($lt)}vis.visit_enum_def(enum_definition))?
522                    }
523                    ItemKind::Struct(ident, generics, variant_data)
524                    | ItemKind::Union(ident, generics, variant_data) => {
525                        try_visit!(vis.visit_ident(ident));
526                        try_visit!(vis.visit_generics(generics));
527                        vis.visit_variant_data(variant_data)
528                    }
529                    ItemKind::Impl(box Impl {
530                        defaultness,
531                        safety,
532                        generics,
533                        constness,
534                        polarity,
535                        of_trait,
536                        self_ty,
537                        items,
538                    }) => {
539                        try_visit!(visit_defaultness(vis, defaultness));
540                        try_visit!(visit_safety(vis, safety));
541                        try_visit!(vis.visit_generics(generics));
542                        try_visit!(visit_constness(vis, constness));
543                        try_visit!(visit_polarity(vis, polarity));
544                        visit_opt!(vis, visit_trait_ref, of_trait);
545                        try_visit!(vis.visit_ty(self_ty));
546                        $(${ignore($mut)}
547                            items.flat_map_in_place(|item| {
548                                vis.flat_map_assoc_item(item, AssocCtxt::Impl { of_trait: of_trait.is_some() })
549                            });
550                        )?
551                        $(${ignore($lt)}
552                            walk_list!(
553                                vis,
554                                visit_assoc_item,
555                                items,
556                                AssocCtxt::Impl { of_trait: of_trait.is_some() }
557                            );
558                            <V as Visitor<$lt>>::Result::output()
559                        )?
560                    }
561                    ItemKind::Trait(box Trait { safety, is_auto: _, ident, generics, bounds, items }) => {
562                        try_visit!(visit_safety(vis, safety));
563                        try_visit!(vis.visit_ident(ident));
564                        try_visit!(vis.visit_generics(generics));
565                        try_visit!(visit_bounds(vis, bounds, BoundKind::Bound));
566                        $(${ignore($mut)}
567                            items.flat_map_in_place(|item| {
568                                vis.flat_map_assoc_item(item, AssocCtxt::Trait)
569                            });
570                        )?
571                        $(${ignore($lt)}
572                            walk_list!(vis, visit_assoc_item, items, AssocCtxt::Trait);
573                            <V as Visitor<$lt>>::Result::output()
574                        )?
575                    }
576                    ItemKind::TraitAlias(ident, generics, bounds) => {
577                        try_visit!(vis.visit_ident(ident));
578                        try_visit!(vis.visit_generics(generics));
579                        visit_bounds(vis, bounds, BoundKind::Bound)
580                    }
581                    ItemKind::MacCall(m) => vis.visit_mac_call(m),
582                    ItemKind::MacroDef(ident, def) => {
583                        try_visit!(vis.visit_ident(ident));
584                        vis.visit_macro_def(def)
585                    }
586                    ItemKind::Delegation(box Delegation {
587                        id,
588                        qself,
589                        path,
590                        ident,
591                        rename,
592                        body,
593                        from_glob: _,
594                    }) => {
595                        try_visit!(visit_id(vis, id));
596                        try_visit!(vis.visit_qself(qself));
597                        try_visit!(vis.visit_path(path));
598                        try_visit!(vis.visit_ident(ident));
599                        visit_opt!(vis, visit_ident, rename);
600                        visit_opt!(vis, visit_block, body);
601                        $(<V as Visitor<$lt>>::Result::output())?
602                    }
603                    ItemKind::DelegationMac(box DelegationMac { qself, prefix, suffixes, body }) => {
604                        try_visit!(vis.visit_qself(qself));
605                        try_visit!(vis.visit_path(prefix));
606                        if let Some(suffixes) = suffixes {
607                            for (ident, rename) in suffixes {
608                                try_visit!(vis.visit_ident(ident));
609                                visit_opt!(vis, visit_ident, rename);
610                            }
611                        }
612                        visit_opt!(vis, visit_block, body);
613                        $(<V as Visitor<$lt>>::Result::output())?
614                    }
615                }
616            }
617        }
618
619        fn walk_const_item<$($lt,)? V: $Visitor$(<$lt>)?>(vis: &mut V, item: &$($lt)? $($mut)? ConstItem) $(-> <V as Visitor<$lt>>::Result)? {
620            let ConstItem { defaultness, ident, generics, ty, expr, define_opaque } = item;
621            try_visit!(visit_defaultness(vis, defaultness));
622            try_visit!(vis.visit_ident(ident));
623            try_visit!(vis.visit_generics(generics));
624            try_visit!(vis.visit_ty(ty));
625            visit_opt!(vis, visit_expr, expr);
626            walk_define_opaques(vis, define_opaque)
627        }
628
629        fn walk_foreign_mod<$($lt,)? V: $Visitor$(<$lt>)?>(vis: &mut V, foreign_mod: &$($lt)? $($mut)? ForeignMod) $(-> <V as Visitor<$lt>>::Result)? {
630            let ForeignMod { extern_span: _, safety, abi: _, items } = foreign_mod;
631            try_visit!(visit_safety(vis, safety));
632            $(${ignore($mut)}
633                items.flat_map_in_place(|item| vis.flat_map_foreign_item(item));
634            )?
635            $(
636                walk_list!(vis, visit_foreign_item, items);
637                <V as Visitor<$lt>>::Result::output()
638            )?
639        }
640
641        fn walk_define_opaques<$($lt,)? V: $Visitor$(<$lt>)?>(
642            visitor: &mut V,
643            define_opaque: &$($lt)? $($mut)? Option<ThinVec<(NodeId, Path)>>,
644        ) $(-> <V as Visitor<$lt>>::Result)? {
645            if let Some(define_opaque) = define_opaque {
646                for (id, path) in define_opaque {
647                    try_visit!(visit_id(visitor, id));
648                    try_visit!(visitor.visit_path(path));
649                }
650            }
651            $(<V as Visitor<$lt>>::Result::output())?
652        }
653
654        impl WalkItemKind for AssocItemKind {
655            type Ctxt = AssocCtxt;
656            fn walk<$($lt,)? V: $Visitor$(<$lt>)?>(
657                &$($lt)? $($mut)? self,
658                span: Span,
659                id: NodeId,
660                visibility: &$($lt)? $($mut)? Visibility,
661                ctxt: Self::Ctxt,
662                vis: &mut V,
663            ) $(-> <V as Visitor<$lt>>::Result)? {
664                match self {
665                    AssocItemKind::Const(item) => {
666                        walk_const_item(vis, item)
667                    }
668                    AssocItemKind::Fn(func) => {
669                        vis.visit_fn(FnKind::Fn(FnCtxt::Assoc(ctxt), visibility, &$($mut)? *func), span, id)
670                    }
671                    AssocItemKind::Type(box TyAlias {
672                        generics,
673                        ident,
674                        bounds,
675                        ty,
676                        defaultness,
677                        $(${ignore($lt)} #[expect(unused)])?
678                        where_clauses,
679                    }) => {
680                        try_visit!(visit_defaultness(vis, defaultness));
681                        try_visit!(vis.visit_ident(ident));
682                        try_visit!(vis.visit_generics(generics));
683                        try_visit!(visit_bounds(vis, bounds, BoundKind::Bound));
684                        visit_opt!(vis, visit_ty, ty);
685                        $(${ignore($mut)}
686                            walk_ty_alias_where_clauses(vis, where_clauses);
687                        )?
688                        $(<V as Visitor<$lt>>::Result::output())?
689                    }
690                    AssocItemKind::MacCall(mac) => {
691                        vis.visit_mac_call(mac)
692                    }
693                    AssocItemKind::Delegation(box Delegation {
694                        id,
695                        qself,
696                        path,
697                        ident,
698                        rename,
699                        body,
700                        from_glob: _,
701                    }) => {
702                        try_visit!(visit_id(vis, id));
703                        try_visit!(vis.visit_qself(qself));
704                        try_visit!(vis.visit_path(path));
705                        try_visit!(vis.visit_ident(ident));
706                        visit_opt!(vis, visit_ident, rename);
707                        visit_opt!(vis, visit_block, body);
708                        $(<V as Visitor<$lt>>::Result::output())?
709                    }
710                    AssocItemKind::DelegationMac(box DelegationMac { qself, prefix, suffixes, body }) => {
711                        try_visit!(vis.visit_qself(qself));
712                        try_visit!(vis.visit_path(prefix));
713                        if let Some(suffixes) = suffixes {
714                            for (ident, rename) in suffixes {
715                                try_visit!(vis.visit_ident(ident));
716                                visit_opt!(vis, visit_ident, rename);
717                            }
718                        }
719                        visit_opt!(vis, visit_block, body);
720                        $(<V as Visitor<$lt>>::Result::output())?
721                    }
722                }
723            }
724        }
725
726        impl WalkItemKind for ForeignItemKind {
727            type Ctxt = ();
728            fn walk<$($lt,)? V: $Visitor$(<$lt>)?>(
729                &$($lt)? $($mut)? self,
730                span: Span,
731                id: NodeId,
732                visibility: &$($lt)? $($mut)? Visibility,
733                _ctxt: Self::Ctxt,
734                vis: &mut V,
735            ) $(-> <V as Visitor<$lt>>::Result)? {
736                match self {
737                    ForeignItemKind::Static(box StaticItem {
738                        ident,
739                        ty,
740                        mutability: _,
741                        expr,
742                        safety: _,
743                        define_opaque,
744                    }) => {
745                        try_visit!(vis.visit_ident(ident));
746                        try_visit!(vis.visit_ty(ty));
747                        visit_opt!(vis, visit_expr, expr);
748                        walk_define_opaques(vis, define_opaque)
749                    }
750                    ForeignItemKind::Fn(func) => {
751                        vis.visit_fn(FnKind::Fn(FnCtxt::Foreign, visibility, &$($mut)?*func), span, id)
752                    }
753                    ForeignItemKind::TyAlias(box TyAlias {
754                        defaultness,
755                        ident,
756                        generics,
757                        bounds,
758                        ty,
759                        $(${ignore($lt)} #[expect(unused)])?
760                        where_clauses,
761                    }) => {
762                        try_visit!(visit_defaultness(vis, defaultness));
763                        try_visit!(vis.visit_ident(ident));
764                        try_visit!(vis.visit_generics(generics));
765                        try_visit!(visit_bounds(vis, bounds, BoundKind::Bound));
766                        visit_opt!(vis, visit_ty, ty);
767                        $(${ignore($mut)}
768                            walk_ty_alias_where_clauses(vis, where_clauses);
769                        )?
770                        $(<V as Visitor<$lt>>::Result::output())?
771                    }
772                    ForeignItemKind::MacCall(mac) => {
773                        vis.visit_mac_call(mac)
774                    }
775                }
776            }
777        }
778
779        fn walk_coroutine_kind<$($lt,)? V: $Visitor$(<$lt>)?>(
780            vis: &mut V,
781            coroutine_kind: &$($lt)? $($mut)? CoroutineKind,
782        ) $(-> <V as Visitor<$lt>>::Result)? {
783            match coroutine_kind {
784                CoroutineKind::Async { span, closure_id, return_impl_trait_id }
785                | CoroutineKind::Gen { span, closure_id, return_impl_trait_id }
786                | CoroutineKind::AsyncGen { span, closure_id, return_impl_trait_id } => {
787                    try_visit!(visit_id(vis, closure_id));
788                    try_visit!(visit_id(vis, return_impl_trait_id));
789                    visit_span(vis, span)
790                }
791            }
792        }
793
794        pub fn walk_pat<$($lt,)? V: $Visitor$(<$lt>)?>(
795            vis: &mut V,
796            pattern: &$($lt)? $($mut)? Pat
797        ) $(-> <V as Visitor<$lt>>::Result)? {
798            let Pat { id, kind, span, tokens: _ } = pattern;
799            try_visit!(visit_id(vis, id));
800            match kind {
801                PatKind::Err(_guar) => {}
802                PatKind::Missing | PatKind::Wild | PatKind::Rest | PatKind::Never => {}
803                PatKind::Ident(_bmode, ident, optional_subpattern) => {
804                    try_visit!(vis.visit_ident(ident));
805                    visit_opt!(vis, visit_pat, optional_subpattern);
806                }
807                PatKind::Expr(expression) => try_visit!(vis.visit_expr(expression)),
808                PatKind::TupleStruct(opt_qself, path, elems) => {
809                    try_visit!(vis.visit_qself(opt_qself));
810                    try_visit!(vis.visit_path(path));
811                    walk_list!(vis, visit_pat, elems);
812                }
813                PatKind::Path(opt_qself, path) => {
814                    try_visit!(vis.visit_qself(opt_qself));
815                    try_visit!(vis.visit_path(path))
816                }
817                PatKind::Struct(opt_qself, path, fields, _rest) => {
818                    try_visit!(vis.visit_qself(opt_qself));
819                    try_visit!(vis.visit_path(path));
820
821                    $(
822                        ${ignore($lt)}
823                        walk_list!(vis, visit_pat_field, fields);
824                    )?
825                    $(
826                        ${ignore($mut)}
827                        fields.flat_map_in_place(|field| vis.flat_map_pat_field(field));
828                    )?
829                }
830                PatKind::Box(subpattern) | PatKind::Deref(subpattern) | PatKind::Paren(subpattern) => {
831                    try_visit!(vis.visit_pat(subpattern));
832                }
833                PatKind::Ref(subpattern, _ /*mutbl*/) => {
834                    try_visit!(vis.visit_pat(subpattern));
835                }
836                PatKind::Range(lower_bound, upper_bound, _end) => {
837                    visit_opt!(vis, visit_expr, lower_bound);
838                    visit_opt!(vis, visit_expr, upper_bound);
839                    try_visit!(visit_span(vis, span));
840                }
841                PatKind::Guard(subpattern, guard_condition) => {
842                    try_visit!(vis.visit_pat(subpattern));
843                    try_visit!(vis.visit_expr(guard_condition));
844                }
845                PatKind::Tuple(elems) | PatKind::Slice(elems) | PatKind::Or(elems) => {
846                    walk_list!(vis, visit_pat, elems);
847                }
848                PatKind::MacCall(mac) => try_visit!(vis.visit_mac_call(mac)),
849            }
850            visit_span(vis, span)
851        }
852
853        pub fn walk_anon_const<$($lt,)? V: $Visitor$(<$lt>)?>(
854            vis: &mut V,
855            constant: &$($lt)? $($mut)? AnonConst,
856        ) $(-> <V as Visitor<$lt>>::Result)? {
857            let AnonConst { id, value } = constant;
858            try_visit!(visit_id(vis, id));
859            vis.visit_expr(value)
860        }
861
862        pub fn walk_path_segment<$($lt,)? V: $Visitor$(<$lt>)?>(
863            vis: &mut V,
864            segment: &$($lt)? $($mut)? PathSegment,
865        ) $(-> <V as Visitor<$lt>>::Result)? {
866            let PathSegment { ident, id, args } = segment;
867            try_visit!(visit_id(vis, id));
868            try_visit!(vis.visit_ident(ident));
869            visit_opt!(vis, visit_generic_args, args);
870            $(<V as Visitor<$lt>>::Result::output())?
871        }
872
873        pub fn walk_block<$($lt,)? V: $Visitor$(<$lt>)?>(
874            vis: &mut V,
875            block: &$($lt)? $($mut)? Block
876        ) $(-> <V as Visitor<$lt>>::Result)? {
877            let Block { stmts, id, rules: _, span, tokens: _ } = block;
878            try_visit!(visit_id(vis, id));
879            $(
880                ${ignore($lt)}
881                walk_list!(vis, visit_stmt, stmts);
882            )?
883            $(
884                ${ignore($mut)}
885                stmts.flat_map_in_place(|stmt| vis.flat_map_stmt(stmt));
886            )?
887            visit_span(vis, span)
888        }
889
890
891        pub fn walk_ty<$($lt,)? V: $Visitor$(<$lt>)?>(
892            vis: &mut V, ty: &$($lt)? $($mut)? Ty
893        ) $(-> <V as Visitor<$lt>>::Result)? {
894            let Ty { id, kind, span, tokens: _ } = ty;
895            try_visit!(visit_id(vis, id));
896            match kind {
897                TyKind::Err(_guar) => {}
898                TyKind::Infer | TyKind::ImplicitSelf | TyKind::Dummy | TyKind::Never | TyKind::CVarArgs => {}
899                TyKind::Slice(ty) | TyKind::Paren(ty) => try_visit!(vis.visit_ty(ty)),
900                TyKind::Ptr(MutTy { ty, mutbl: _ }) => try_visit!(vis.visit_ty(ty)),
901                TyKind::Ref(opt_lifetime, MutTy { ty, mutbl: _ })
902                | TyKind::PinnedRef(opt_lifetime, MutTy { ty, mutbl: _ }) => {
903                    // FIXME(fee1-dead) asymmetry
904                    visit_opt!(vis, visit_lifetime, opt_lifetime$(${ignore($lt)}, LifetimeCtxt::Ref)?);
905                    try_visit!(vis.visit_ty(ty));
906                }
907                TyKind::Tup(tuple_element_types) => {
908                    walk_list!(vis, visit_ty, tuple_element_types);
909                }
910                TyKind::BareFn(function_declaration) => {
911                    let BareFnTy { safety, ext: _, generic_params, decl, decl_span } =
912                        &$($mut)? **function_declaration;
913                    visit_safety(vis, safety);
914                    $(
915                        ${ignore($lt)}
916                        walk_list!(vis, visit_generic_param, generic_params);
917                    )?
918                    $(
919                        ${ignore($mut)}
920                        generic_params.flat_map_in_place(|param| vis.flat_map_generic_param(param));
921                    )?
922
923                    try_visit!(vis.visit_fn_decl(decl));
924                    try_visit!(visit_span(vis, decl_span));
925                }
926                TyKind::UnsafeBinder(binder) => {
927                    $(
928                        ${ignore($lt)}
929                        walk_list!(vis, visit_generic_param, &binder.generic_params);
930                    )?
931                    $(
932                        ${ignore($mut)}
933                        binder.generic_params.flat_map_in_place(|param| vis.flat_map_generic_param(param));
934                    )?
935                    try_visit!(vis.visit_ty(&$($mut)?binder.inner_ty));
936                }
937                TyKind::Path(maybe_qself, path) => {
938                    try_visit!(vis.visit_qself(maybe_qself));
939                    try_visit!(vis.visit_path(path));
940                }
941                TyKind::Pat(ty, pat) => {
942                    try_visit!(vis.visit_ty(ty));
943                    try_visit!(vis.visit_ty_pat(pat));
944                }
945                TyKind::Array(ty, length) => {
946                    try_visit!(vis.visit_ty(ty));
947                    try_visit!(vis.visit_anon_const(length));
948                }
949                TyKind::TraitObject(bounds, _syntax) => {
950                    walk_list!(vis, visit_param_bound, bounds, BoundKind::TraitObject);
951                }
952                TyKind::ImplTrait(id, bounds) => {
953                    try_visit!(visit_id(vis, id));
954                    walk_list!(vis, visit_param_bound, bounds, BoundKind::Impl);
955                }
956                TyKind::Typeof(expression) => try_visit!(vis.visit_anon_const(expression)),
957
958                TyKind::MacCall(mac) => try_visit!(vis.visit_mac_call(mac)),
959            }
960            visit_span(vis, span)
961        }
962    };
963}
964
965common_visitor_and_walkers!(Visitor<'a>);
966
967pub fn walk_crate<'a, V: Visitor<'a>>(visitor: &mut V, krate: &'a Crate) -> V::Result {
968    let Crate { attrs, items, spans: _, id: _, is_placeholder: _ } = krate;
969    walk_list!(visitor, visit_attribute, attrs);
970    walk_list!(visitor, visit_item, items);
971    V::Result::output()
972}
973
974pub fn walk_local<'a, V: Visitor<'a>>(visitor: &mut V, local: &'a Local) -> V::Result {
975    let Local { id: _, super_: _, pat, ty, kind, span: _, colon_sp: _, attrs, tokens: _ } = local;
976    walk_list!(visitor, visit_attribute, attrs);
977    try_visit!(visitor.visit_pat(pat));
978    visit_opt!(visitor, visit_ty, ty);
979    if let Some((init, els)) = kind.init_else_opt() {
980        try_visit!(visitor.visit_expr(init));
981        visit_opt!(visitor, visit_block, els);
982    }
983    V::Result::output()
984}
985
986pub fn walk_poly_trait_ref<'a, V>(visitor: &mut V, trait_ref: &'a PolyTraitRef) -> V::Result
987where
988    V: Visitor<'a>,
989{
990    let PolyTraitRef { bound_generic_params, modifiers: _, trait_ref, span: _ } = trait_ref;
991    walk_list!(visitor, visit_generic_param, bound_generic_params);
992    visitor.visit_trait_ref(trait_ref)
993}
994
995pub fn walk_trait_ref<'a, V: Visitor<'a>>(visitor: &mut V, trait_ref: &'a TraitRef) -> V::Result {
996    let TraitRef { path, ref_id } = trait_ref;
997    try_visit!(visitor.visit_path(path));
998    visitor.visit_id(*ref_id)
999}
1000
1001pub fn walk_enum_def<'a, V: Visitor<'a>>(
1002    visitor: &mut V,
1003    EnumDef { variants }: &'a EnumDef,
1004) -> V::Result {
1005    walk_list!(visitor, visit_variant, variants);
1006    V::Result::output()
1007}
1008
1009pub fn walk_variant<'a, V: Visitor<'a>>(visitor: &mut V, variant: &'a Variant) -> V::Result
1010where
1011    V: Visitor<'a>,
1012{
1013    let Variant { attrs, id: _, span: _, vis, ident, data, disr_expr, is_placeholder: _ } = variant;
1014    walk_list!(visitor, visit_attribute, attrs);
1015    try_visit!(visitor.visit_vis(vis));
1016    try_visit!(visitor.visit_ident(ident));
1017    try_visit!(visitor.visit_variant_data(data));
1018    visit_opt!(visitor, visit_variant_discr, disr_expr);
1019    V::Result::output()
1020}
1021
1022pub fn walk_expr_field<'a, V: Visitor<'a>>(visitor: &mut V, f: &'a ExprField) -> V::Result {
1023    let ExprField { attrs, id: _, span: _, ident, expr, is_shorthand: _, is_placeholder: _ } = f;
1024    walk_list!(visitor, visit_attribute, attrs);
1025    try_visit!(visitor.visit_ident(ident));
1026    try_visit!(visitor.visit_expr(expr));
1027    V::Result::output()
1028}
1029
1030pub fn walk_pat_field<'a, V: Visitor<'a>>(visitor: &mut V, fp: &'a PatField) -> V::Result {
1031    let PatField { ident, pat, is_shorthand: _, attrs, id: _, span: _, is_placeholder: _ } = fp;
1032    walk_list!(visitor, visit_attribute, attrs);
1033    try_visit!(visitor.visit_ident(ident));
1034    try_visit!(visitor.visit_pat(pat));
1035    V::Result::output()
1036}
1037
1038pub fn walk_ty_pat<'a, V: Visitor<'a>>(visitor: &mut V, tp: &'a TyPat) -> V::Result {
1039    let TyPat { id: _, kind, span: _, tokens: _ } = tp;
1040    match kind {
1041        TyPatKind::Range(start, end, _include_end) => {
1042            visit_opt!(visitor, visit_anon_const, start);
1043            visit_opt!(visitor, visit_anon_const, end);
1044        }
1045        TyPatKind::Or(variants) => walk_list!(visitor, visit_ty_pat, variants),
1046        TyPatKind::Err(_) => {}
1047    }
1048    V::Result::output()
1049}
1050
1051fn walk_qself<'a, V: Visitor<'a>>(visitor: &mut V, qself: &'a Option<P<QSelf>>) -> V::Result {
1052    if let Some(qself) = qself {
1053        let QSelf { ty, path_span: _, position: _ } = &**qself;
1054        try_visit!(visitor.visit_ty(ty));
1055    }
1056    V::Result::output()
1057}
1058
1059pub fn walk_path<'a, V: Visitor<'a>>(visitor: &mut V, path: &'a Path) -> V::Result {
1060    let Path { span: _, segments, tokens: _ } = path;
1061    walk_list!(visitor, visit_path_segment, segments);
1062    V::Result::output()
1063}
1064
1065pub fn walk_use_tree<'a, V: Visitor<'a>>(
1066    visitor: &mut V,
1067    use_tree: &'a UseTree,
1068    id: NodeId,
1069) -> V::Result {
1070    let UseTree { prefix, kind, span: _ } = use_tree;
1071    try_visit!(visitor.visit_id(id));
1072    try_visit!(visitor.visit_path(prefix));
1073    match kind {
1074        UseTreeKind::Simple(rename) => {
1075            // The extra IDs are handled during AST lowering.
1076            visit_opt!(visitor, visit_ident, rename);
1077        }
1078        UseTreeKind::Glob => {}
1079        UseTreeKind::Nested { items, span: _ } => {
1080            for &(ref nested_tree, nested_id) in items {
1081                try_visit!(visitor.visit_use_tree(nested_tree, nested_id, true));
1082            }
1083        }
1084    }
1085    V::Result::output()
1086}
1087
1088pub fn walk_generic_args<'a, V>(visitor: &mut V, generic_args: &'a GenericArgs) -> V::Result
1089where
1090    V: Visitor<'a>,
1091{
1092    match generic_args {
1093        GenericArgs::AngleBracketed(AngleBracketedArgs { span: _, args }) => {
1094            for arg in args {
1095                match arg {
1096                    AngleBracketedArg::Arg(a) => try_visit!(visitor.visit_generic_arg(a)),
1097                    AngleBracketedArg::Constraint(c) => {
1098                        try_visit!(visitor.visit_assoc_item_constraint(c))
1099                    }
1100                }
1101            }
1102        }
1103        GenericArgs::Parenthesized(data) => {
1104            let ParenthesizedArgs { span: _, inputs, inputs_span: _, output } = data;
1105            walk_list!(visitor, visit_ty, inputs);
1106            try_visit!(visitor.visit_fn_ret_ty(output));
1107        }
1108        GenericArgs::ParenthesizedElided(_span) => {}
1109    }
1110    V::Result::output()
1111}
1112
1113pub fn walk_generic_arg<'a, V>(visitor: &mut V, generic_arg: &'a GenericArg) -> V::Result
1114where
1115    V: Visitor<'a>,
1116{
1117    match generic_arg {
1118        GenericArg::Lifetime(lt) => visitor.visit_lifetime(lt, LifetimeCtxt::GenericArg),
1119        GenericArg::Type(ty) => visitor.visit_ty(ty),
1120        GenericArg::Const(ct) => visitor.visit_anon_const(ct),
1121    }
1122}
1123
1124pub fn walk_assoc_item_constraint<'a, V: Visitor<'a>>(
1125    visitor: &mut V,
1126    constraint: &'a AssocItemConstraint,
1127) -> V::Result {
1128    let AssocItemConstraint { id: _, ident, gen_args, kind, span: _ } = constraint;
1129    try_visit!(visitor.visit_ident(ident));
1130    visit_opt!(visitor, visit_generic_args, gen_args);
1131    match kind {
1132        AssocItemConstraintKind::Equality { term } => match term {
1133            Term::Ty(ty) => try_visit!(visitor.visit_ty(ty)),
1134            Term::Const(c) => try_visit!(visitor.visit_anon_const(c)),
1135        },
1136        AssocItemConstraintKind::Bound { bounds } => {
1137            walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
1138        }
1139    }
1140    V::Result::output()
1141}
1142
1143pub fn walk_param_bound<'a, V: Visitor<'a>>(visitor: &mut V, bound: &'a GenericBound) -> V::Result {
1144    match bound {
1145        GenericBound::Trait(trait_ref) => visitor.visit_poly_trait_ref(trait_ref),
1146        GenericBound::Outlives(lifetime) => visitor.visit_lifetime(lifetime, LifetimeCtxt::Bound),
1147        GenericBound::Use(args, _span) => {
1148            walk_list!(visitor, visit_precise_capturing_arg, args);
1149            V::Result::output()
1150        }
1151    }
1152}
1153
1154pub fn walk_precise_capturing_arg<'a, V: Visitor<'a>>(
1155    visitor: &mut V,
1156    arg: &'a PreciseCapturingArg,
1157) -> V::Result {
1158    match arg {
1159        PreciseCapturingArg::Lifetime(lt) => visitor.visit_lifetime(lt, LifetimeCtxt::GenericArg),
1160        PreciseCapturingArg::Arg(path, id) => {
1161            try_visit!(visitor.visit_id(*id));
1162            visitor.visit_path(path)
1163        }
1164    }
1165}
1166
1167pub fn walk_generic_param<'a, V: Visitor<'a>>(
1168    visitor: &mut V,
1169    param: &'a GenericParam,
1170) -> V::Result {
1171    let GenericParam { id: _, ident, attrs, bounds, is_placeholder: _, kind, colon_span: _ } =
1172        param;
1173    walk_list!(visitor, visit_attribute, attrs);
1174    try_visit!(visitor.visit_ident(ident));
1175    walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
1176    match kind {
1177        GenericParamKind::Lifetime => (),
1178        GenericParamKind::Type { default } => visit_opt!(visitor, visit_ty, default),
1179        GenericParamKind::Const { ty, default, kw_span: _ } => {
1180            try_visit!(visitor.visit_ty(ty));
1181            visit_opt!(visitor, visit_anon_const, default);
1182        }
1183    }
1184    V::Result::output()
1185}
1186
1187pub fn walk_generics<'a, V: Visitor<'a>>(visitor: &mut V, generics: &'a Generics) -> V::Result {
1188    let Generics { params, where_clause, span: _ } = generics;
1189    let WhereClause { has_where_token: _, predicates, span: _ } = where_clause;
1190    walk_list!(visitor, visit_generic_param, params);
1191    walk_list!(visitor, visit_where_predicate, predicates);
1192    V::Result::output()
1193}
1194
1195pub fn walk_closure_binder<'a, V: Visitor<'a>>(
1196    visitor: &mut V,
1197    binder: &'a ClosureBinder,
1198) -> V::Result {
1199    match binder {
1200        ClosureBinder::NotPresent => {}
1201        ClosureBinder::For { generic_params, span: _ } => {
1202            walk_list!(visitor, visit_generic_param, generic_params)
1203        }
1204    }
1205    V::Result::output()
1206}
1207
1208pub fn walk_contract<'a, V: Visitor<'a>>(visitor: &mut V, c: &'a FnContract) -> V::Result {
1209    let FnContract { requires, ensures } = c;
1210    if let Some(pred) = requires {
1211        visitor.visit_expr(pred);
1212    }
1213    if let Some(pred) = ensures {
1214        visitor.visit_expr(pred);
1215    }
1216    V::Result::output()
1217}
1218
1219pub fn walk_where_predicate<'a, V: Visitor<'a>>(
1220    visitor: &mut V,
1221    predicate: &'a WherePredicate,
1222) -> V::Result {
1223    let WherePredicate { attrs, kind, id: _, span: _, is_placeholder: _ } = predicate;
1224    walk_list!(visitor, visit_attribute, attrs);
1225    visitor.visit_where_predicate_kind(kind)
1226}
1227
1228pub fn walk_where_predicate_kind<'a, V: Visitor<'a>>(
1229    visitor: &mut V,
1230    kind: &'a WherePredicateKind,
1231) -> V::Result {
1232    match kind {
1233        WherePredicateKind::BoundPredicate(WhereBoundPredicate {
1234            bounded_ty,
1235            bounds,
1236            bound_generic_params,
1237        }) => {
1238            walk_list!(visitor, visit_generic_param, bound_generic_params);
1239            try_visit!(visitor.visit_ty(bounded_ty));
1240            walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
1241        }
1242        WherePredicateKind::RegionPredicate(WhereRegionPredicate { lifetime, bounds }) => {
1243            try_visit!(visitor.visit_lifetime(lifetime, LifetimeCtxt::Bound));
1244            walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
1245        }
1246        WherePredicateKind::EqPredicate(WhereEqPredicate { lhs_ty, rhs_ty }) => {
1247            try_visit!(visitor.visit_ty(lhs_ty));
1248            try_visit!(visitor.visit_ty(rhs_ty));
1249        }
1250    }
1251    V::Result::output()
1252}
1253
1254pub fn walk_fn_ret_ty<'a, V: Visitor<'a>>(visitor: &mut V, ret_ty: &'a FnRetTy) -> V::Result {
1255    match ret_ty {
1256        FnRetTy::Default(_span) => {}
1257        FnRetTy::Ty(output_ty) => try_visit!(visitor.visit_ty(output_ty)),
1258    }
1259    V::Result::output()
1260}
1261
1262pub fn walk_fn_decl<'a, V: Visitor<'a>>(
1263    visitor: &mut V,
1264    FnDecl { inputs, output }: &'a FnDecl,
1265) -> V::Result {
1266    walk_list!(visitor, visit_param, inputs);
1267    visitor.visit_fn_ret_ty(output)
1268}
1269
1270pub fn walk_fn<'a, V: Visitor<'a>>(visitor: &mut V, kind: FnKind<'a>) -> V::Result {
1271    match kind {
1272        FnKind::Fn(
1273            _ctxt,
1274            _vis,
1275            Fn {
1276                defaultness: _,
1277                ident,
1278                sig: FnSig { header, decl, span: _ },
1279                generics,
1280                contract,
1281                body,
1282                define_opaque,
1283            },
1284        ) => {
1285            // Visibility is visited as a part of the item.
1286            try_visit!(visitor.visit_ident(ident));
1287            try_visit!(visitor.visit_fn_header(header));
1288            try_visit!(visitor.visit_generics(generics));
1289            try_visit!(visitor.visit_fn_decl(decl));
1290            visit_opt!(visitor, visit_contract, contract);
1291            visit_opt!(visitor, visit_block, body);
1292            try_visit!(walk_define_opaques(visitor, define_opaque));
1293        }
1294        FnKind::Closure(binder, coroutine_kind, decl, body) => {
1295            try_visit!(visitor.visit_closure_binder(binder));
1296            visit_opt!(visitor, visit_coroutine_kind, coroutine_kind.as_ref());
1297            try_visit!(visitor.visit_fn_decl(decl));
1298            try_visit!(visitor.visit_expr(body));
1299        }
1300    }
1301    V::Result::output()
1302}
1303
1304pub fn walk_variant_data<'a, V: Visitor<'a>>(visitor: &mut V, data: &'a VariantData) -> V::Result {
1305    visit_opt!(visitor, visit_id, data.ctor_node_id());
1306    walk_list!(visitor, visit_field_def, data.fields());
1307    V::Result::output()
1308}
1309
1310pub fn walk_field_def<'a, V: Visitor<'a>>(visitor: &mut V, field: &'a FieldDef) -> V::Result {
1311    let FieldDef { attrs, id: _, span: _, vis, ident, ty, is_placeholder: _, safety: _, default } =
1312        field;
1313    walk_list!(visitor, visit_attribute, attrs);
1314    try_visit!(visitor.visit_vis(vis));
1315    visit_opt!(visitor, visit_ident, ident);
1316    try_visit!(visitor.visit_ty(ty));
1317    visit_opt!(visitor, visit_anon_const, &*default);
1318    V::Result::output()
1319}
1320
1321pub fn walk_stmt<'a, V: Visitor<'a>>(visitor: &mut V, statement: &'a Stmt) -> V::Result {
1322    let Stmt { id: _, kind, span: _ } = statement;
1323    match kind {
1324        StmtKind::Let(local) => try_visit!(visitor.visit_local(local)),
1325        StmtKind::Item(item) => try_visit!(visitor.visit_item(item)),
1326        StmtKind::Expr(expr) | StmtKind::Semi(expr) => try_visit!(visitor.visit_expr(expr)),
1327        StmtKind::Empty => {}
1328        StmtKind::MacCall(mac) => {
1329            let MacCallStmt { mac, attrs, style: _, tokens: _ } = &**mac;
1330            walk_list!(visitor, visit_attribute, attrs);
1331            try_visit!(visitor.visit_mac_call(mac));
1332        }
1333    }
1334    V::Result::output()
1335}
1336
1337pub fn walk_mac<'a, V: Visitor<'a>>(visitor: &mut V, mac: &'a MacCall) -> V::Result {
1338    let MacCall { path, args: _ } = mac;
1339    visitor.visit_path(path)
1340}
1341
1342pub fn walk_inline_asm<'a, V: Visitor<'a>>(visitor: &mut V, asm: &'a InlineAsm) -> V::Result {
1343    let InlineAsm {
1344        asm_macro: _,
1345        template: _,
1346        template_strs: _,
1347        operands,
1348        clobber_abis: _,
1349        options: _,
1350        line_spans: _,
1351    } = asm;
1352    for (op, _span) in operands {
1353        match op {
1354            InlineAsmOperand::In { expr, reg: _ }
1355            | InlineAsmOperand::Out { expr: Some(expr), reg: _, late: _ }
1356            | InlineAsmOperand::InOut { expr, reg: _, late: _ } => {
1357                try_visit!(visitor.visit_expr(expr))
1358            }
1359            InlineAsmOperand::Out { expr: None, reg: _, late: _ } => {}
1360            InlineAsmOperand::SplitInOut { in_expr, out_expr, reg: _, late: _ } => {
1361                try_visit!(visitor.visit_expr(in_expr));
1362                visit_opt!(visitor, visit_expr, out_expr);
1363            }
1364            InlineAsmOperand::Const { anon_const } => {
1365                try_visit!(visitor.visit_anon_const(anon_const))
1366            }
1367            InlineAsmOperand::Sym { sym } => try_visit!(visitor.visit_inline_asm_sym(sym)),
1368            InlineAsmOperand::Label { block } => try_visit!(visitor.visit_block(block)),
1369        }
1370    }
1371    V::Result::output()
1372}
1373
1374pub fn walk_inline_asm_sym<'a, V: Visitor<'a>>(
1375    visitor: &mut V,
1376    InlineAsmSym { id, qself, path }: &'a InlineAsmSym,
1377) -> V::Result {
1378    try_visit!(visitor.visit_qself(qself));
1379    try_visit!(visitor.visit_id(*id));
1380    visitor.visit_path(path)
1381}
1382
1383pub fn walk_format_args<'a, V: Visitor<'a>>(visitor: &mut V, fmt: &'a FormatArgs) -> V::Result {
1384    let FormatArgs { span: _, template: _, arguments, uncooked_fmt_str: _ } = fmt;
1385    for FormatArgument { kind, expr } in arguments.all_args() {
1386        match kind {
1387            FormatArgumentKind::Named(ident) | FormatArgumentKind::Captured(ident) => {
1388                try_visit!(visitor.visit_ident(ident))
1389            }
1390            FormatArgumentKind::Normal => {}
1391        }
1392        try_visit!(visitor.visit_expr(expr));
1393    }
1394    V::Result::output()
1395}
1396
1397pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) -> V::Result {
1398    let Expr { id, kind, span, attrs, tokens: _ } = expression;
1399    walk_list!(visitor, visit_attribute, attrs);
1400    match kind {
1401        ExprKind::Array(subexpressions) => {
1402            walk_list!(visitor, visit_expr, subexpressions);
1403        }
1404        ExprKind::ConstBlock(anon_const) => try_visit!(visitor.visit_anon_const(anon_const)),
1405        ExprKind::Repeat(element, count) => {
1406            try_visit!(visitor.visit_expr(element));
1407            try_visit!(visitor.visit_anon_const(count));
1408        }
1409        ExprKind::Struct(se) => {
1410            let StructExpr { qself, path, fields, rest } = &**se;
1411            try_visit!(visitor.visit_qself(qself));
1412            try_visit!(visitor.visit_id(*id));
1413            try_visit!(visitor.visit_path(path));
1414            walk_list!(visitor, visit_expr_field, fields);
1415            match rest {
1416                StructRest::Base(expr) => try_visit!(visitor.visit_expr(expr)),
1417                StructRest::Rest(_span) => {}
1418                StructRest::None => {}
1419            }
1420        }
1421        ExprKind::Tup(subexpressions) => {
1422            walk_list!(visitor, visit_expr, subexpressions);
1423        }
1424        ExprKind::Call(callee_expression, arguments) => {
1425            try_visit!(visitor.visit_expr(callee_expression));
1426            walk_list!(visitor, visit_expr, arguments);
1427        }
1428        ExprKind::MethodCall(box MethodCall { seg, receiver, args, span: _ }) => {
1429            try_visit!(visitor.visit_expr(receiver));
1430            try_visit!(visitor.visit_path_segment(seg));
1431            walk_list!(visitor, visit_expr, args);
1432        }
1433        ExprKind::Binary(_op, left_expression, right_expression) => {
1434            try_visit!(visitor.visit_expr(left_expression));
1435            try_visit!(visitor.visit_expr(right_expression));
1436        }
1437        ExprKind::AddrOf(_kind, _mutbl, subexpression) => {
1438            try_visit!(visitor.visit_expr(subexpression));
1439        }
1440        ExprKind::Unary(_op, subexpression) => {
1441            try_visit!(visitor.visit_expr(subexpression));
1442        }
1443        ExprKind::Cast(subexpression, typ) | ExprKind::Type(subexpression, typ) => {
1444            try_visit!(visitor.visit_expr(subexpression));
1445            try_visit!(visitor.visit_ty(typ));
1446        }
1447        ExprKind::Let(pat, expr, _span, _recovered) => {
1448            try_visit!(visitor.visit_pat(pat));
1449            try_visit!(visitor.visit_expr(expr));
1450        }
1451        ExprKind::If(head_expression, if_block, optional_else) => {
1452            try_visit!(visitor.visit_expr(head_expression));
1453            try_visit!(visitor.visit_block(if_block));
1454            visit_opt!(visitor, visit_expr, optional_else);
1455        }
1456        ExprKind::While(subexpression, block, opt_label) => {
1457            visit_opt!(visitor, visit_label, opt_label);
1458            try_visit!(visitor.visit_expr(subexpression));
1459            try_visit!(visitor.visit_block(block));
1460        }
1461        ExprKind::ForLoop { pat, iter, body, label, kind: _ } => {
1462            visit_opt!(visitor, visit_label, label);
1463            try_visit!(visitor.visit_pat(pat));
1464            try_visit!(visitor.visit_expr(iter));
1465            try_visit!(visitor.visit_block(body));
1466        }
1467        ExprKind::Loop(block, opt_label, _span) => {
1468            visit_opt!(visitor, visit_label, opt_label);
1469            try_visit!(visitor.visit_block(block));
1470        }
1471        ExprKind::Match(subexpression, arms, _kind) => {
1472            try_visit!(visitor.visit_expr(subexpression));
1473            walk_list!(visitor, visit_arm, arms);
1474        }
1475        ExprKind::Closure(box Closure {
1476            binder,
1477            capture_clause,
1478            coroutine_kind,
1479            constness: _,
1480            movability: _,
1481            fn_decl,
1482            body,
1483            fn_decl_span: _,
1484            fn_arg_span: _,
1485        }) => {
1486            try_visit!(visitor.visit_capture_by(capture_clause));
1487            try_visit!(visitor.visit_fn(
1488                FnKind::Closure(binder, coroutine_kind, fn_decl, body),
1489                *span,
1490                *id
1491            ));
1492        }
1493        ExprKind::Block(block, opt_label) => {
1494            visit_opt!(visitor, visit_label, opt_label);
1495            try_visit!(visitor.visit_block(block));
1496        }
1497        ExprKind::Gen(_capt, body, _kind, _decl_span) => try_visit!(visitor.visit_block(body)),
1498        ExprKind::Await(expr, _span) => try_visit!(visitor.visit_expr(expr)),
1499        ExprKind::Use(expr, _span) => try_visit!(visitor.visit_expr(expr)),
1500        ExprKind::Assign(lhs, rhs, _span) => {
1501            try_visit!(visitor.visit_expr(lhs));
1502            try_visit!(visitor.visit_expr(rhs));
1503        }
1504        ExprKind::AssignOp(_op, left_expression, right_expression) => {
1505            try_visit!(visitor.visit_expr(left_expression));
1506            try_visit!(visitor.visit_expr(right_expression));
1507        }
1508        ExprKind::Field(subexpression, ident) => {
1509            try_visit!(visitor.visit_expr(subexpression));
1510            try_visit!(visitor.visit_ident(ident));
1511        }
1512        ExprKind::Index(main_expression, index_expression, _span) => {
1513            try_visit!(visitor.visit_expr(main_expression));
1514            try_visit!(visitor.visit_expr(index_expression));
1515        }
1516        ExprKind::Range(start, end, _limit) => {
1517            visit_opt!(visitor, visit_expr, start);
1518            visit_opt!(visitor, visit_expr, end);
1519        }
1520        ExprKind::Underscore => {}
1521        ExprKind::Path(maybe_qself, path) => {
1522            try_visit!(visitor.visit_qself(maybe_qself));
1523            try_visit!(visitor.visit_id(*id));
1524            try_visit!(visitor.visit_path(path));
1525        }
1526        ExprKind::Break(opt_label, opt_expr) => {
1527            visit_opt!(visitor, visit_label, opt_label);
1528            visit_opt!(visitor, visit_expr, opt_expr);
1529        }
1530        ExprKind::Continue(opt_label) => {
1531            visit_opt!(visitor, visit_label, opt_label);
1532        }
1533        ExprKind::Ret(optional_expression) => {
1534            visit_opt!(visitor, visit_expr, optional_expression);
1535        }
1536        ExprKind::Yeet(optional_expression) => {
1537            visit_opt!(visitor, visit_expr, optional_expression);
1538        }
1539        ExprKind::Become(expr) => try_visit!(visitor.visit_expr(expr)),
1540        ExprKind::MacCall(mac) => try_visit!(visitor.visit_mac_call(mac)),
1541        ExprKind::Paren(subexpression) => try_visit!(visitor.visit_expr(subexpression)),
1542        ExprKind::InlineAsm(asm) => try_visit!(visitor.visit_inline_asm(asm)),
1543        ExprKind::FormatArgs(f) => try_visit!(visitor.visit_format_args(f)),
1544        ExprKind::OffsetOf(container, fields) => {
1545            try_visit!(visitor.visit_ty(container));
1546            walk_list!(visitor, visit_ident, fields.iter());
1547        }
1548        ExprKind::Yield(kind) => {
1549            visit_opt!(visitor, visit_expr, kind.expr());
1550        }
1551        ExprKind::Try(subexpression) => try_visit!(visitor.visit_expr(subexpression)),
1552        ExprKind::TryBlock(body) => try_visit!(visitor.visit_block(body)),
1553        ExprKind::Lit(_token) => {}
1554        ExprKind::IncludedBytes(_bytes) => {}
1555        ExprKind::UnsafeBinderCast(_kind, expr, ty) => {
1556            try_visit!(visitor.visit_expr(expr));
1557            visit_opt!(visitor, visit_ty, ty);
1558        }
1559        ExprKind::Err(_guar) => {}
1560        ExprKind::Dummy => {}
1561    }
1562
1563    V::Result::output()
1564}
1565
1566pub fn walk_param<'a, V: Visitor<'a>>(visitor: &mut V, param: &'a Param) -> V::Result {
1567    let Param { attrs, ty, pat, id: _, span: _, is_placeholder: _ } = param;
1568    walk_list!(visitor, visit_attribute, attrs);
1569    try_visit!(visitor.visit_pat(pat));
1570    try_visit!(visitor.visit_ty(ty));
1571    V::Result::output()
1572}
1573
1574pub fn walk_arm<'a, V: Visitor<'a>>(visitor: &mut V, arm: &'a Arm) -> V::Result {
1575    let Arm { attrs, pat, guard, body, span: _, id: _, is_placeholder: _ } = arm;
1576    walk_list!(visitor, visit_attribute, attrs);
1577    try_visit!(visitor.visit_pat(pat));
1578    visit_opt!(visitor, visit_expr, guard);
1579    visit_opt!(visitor, visit_expr, body);
1580    V::Result::output()
1581}
1582
1583pub fn walk_vis<'a, V: Visitor<'a>>(visitor: &mut V, vis: &'a Visibility) -> V::Result {
1584    let Visibility { kind, span: _, tokens: _ } = vis;
1585    match kind {
1586        VisibilityKind::Restricted { path, id, shorthand: _ } => {
1587            try_visit!(visitor.visit_id(*id));
1588            try_visit!(visitor.visit_path(path));
1589        }
1590        VisibilityKind::Public | VisibilityKind::Inherited => {}
1591    }
1592    V::Result::output()
1593}
1594
1595pub fn walk_attribute<'a, V: Visitor<'a>>(visitor: &mut V, attr: &'a Attribute) -> V::Result {
1596    let Attribute { kind, id: _, style: _, span: _ } = attr;
1597    match kind {
1598        AttrKind::Normal(normal) => {
1599            let NormalAttr { item, tokens: _ } = &**normal;
1600            let AttrItem { unsafety: _, path, args, tokens: _ } = item;
1601            try_visit!(visitor.visit_path(path));
1602            try_visit!(walk_attr_args(visitor, args));
1603        }
1604        AttrKind::DocComment(_kind, _sym) => {}
1605    }
1606    V::Result::output()
1607}
1608
1609pub fn walk_attr_args<'a, V: Visitor<'a>>(visitor: &mut V, args: &'a AttrArgs) -> V::Result {
1610    match args {
1611        AttrArgs::Empty => {}
1612        AttrArgs::Delimited(_args) => {}
1613        AttrArgs::Eq { expr, .. } => try_visit!(visitor.visit_expr(expr)),
1614    }
1615    V::Result::output()
1616}