| //! AST walker. Each overridden visit method has full control over what |
| //! happens with its node, it can do its own traversal of the node's children, |
| //! call `visit::walk_*` to apply the default traversal algorithm, or prevent |
| //! deeper traversal by doing nothing. |
| //! |
| //! Note: it is an important invariant that the default visitor walks the body |
| //! of a function in "execution order" (more concretely, reverse post-order |
| //! with respect to the CFG implied by the AST), meaning that if AST node A may |
| //! execute before AST node B, then A is visited first. The borrow checker in |
| //! particular relies on this property. |
| //! |
| //! Note: walking an AST before macro expansion is probably a bad idea. For |
| //! instance, a walker looking for item names in a module will miss all of |
| //! those that are created by the expansion of a macro. |
| |
| use crate::{ast::*, StaticItem}; |
| |
| use rustc_span::symbol::Ident; |
| use rustc_span::Span; |
| |
| #[derive(Copy, Clone, Debug, PartialEq)] |
| pub enum AssocCtxt { |
| Trait, |
| Impl, |
| } |
| |
| #[derive(Copy, Clone, Debug, PartialEq)] |
| pub enum FnCtxt { |
| Free, |
| Foreign, |
| Assoc(AssocCtxt), |
| } |
| |
| #[derive(Copy, Clone, Debug)] |
| pub enum BoundKind { |
| /// Trait bounds in generics bounds and type/trait alias. |
| /// E.g., `<T: Bound>`, `type A: Bound`, or `where T: Bound`. |
| Bound, |
| |
| /// Trait bounds in `impl` type. |
| /// E.g., `type Foo = impl Bound1 + Bound2 + Bound3`. |
| Impl, |
| |
| /// Trait bounds in trait object type. |
| /// E.g., `dyn Bound1 + Bound2 + Bound3`. |
| TraitObject, |
| |
| /// Super traits of a trait. |
| /// E.g., `trait A: B` |
| SuperTraits, |
| } |
| |
| #[derive(Copy, Clone, Debug)] |
| pub enum FnKind<'a> { |
| /// E.g., `fn foo()`, `fn foo(&self)`, or `extern "Abi" fn foo()`. |
| Fn(FnCtxt, Ident, &'a FnSig, &'a Visibility, &'a Generics, Option<&'a Block>), |
| |
| /// E.g., `|x, y| body`. |
| Closure(&'a ClosureBinder, &'a FnDecl, &'a Expr), |
| } |
| |
| impl<'a> FnKind<'a> { |
| pub fn header(&self) -> Option<&'a FnHeader> { |
| match *self { |
| FnKind::Fn(_, _, sig, _, _, _) => Some(&sig.header), |
| FnKind::Closure(_, _, _) => None, |
| } |
| } |
| |
| pub fn ident(&self) -> Option<&Ident> { |
| match self { |
| FnKind::Fn(_, ident, ..) => Some(ident), |
| _ => None, |
| } |
| } |
| |
| pub fn decl(&self) -> &'a FnDecl { |
| match self { |
| FnKind::Fn(_, _, sig, _, _, _) => &sig.decl, |
| FnKind::Closure(_, decl, _) => decl, |
| } |
| } |
| |
| pub fn ctxt(&self) -> Option<FnCtxt> { |
| match self { |
| FnKind::Fn(ctxt, ..) => Some(*ctxt), |
| FnKind::Closure(..) => None, |
| } |
| } |
| } |
| |
| #[derive(Copy, Clone, Debug)] |
| pub enum LifetimeCtxt { |
| /// Appears in a reference type. |
| Ref, |
| /// Appears as a bound on a type or another lifetime. |
| Bound, |
| /// Appears as a generic argument. |
| GenericArg, |
| } |
| |
| /// Each method of the `Visitor` trait is a hook to be potentially |
| /// overridden. Each method's default implementation recursively visits |
| /// the substructure of the input via the corresponding `walk` method; |
| /// e.g., the `visit_item` method by default calls `visit::walk_item`. |
| /// |
| /// If you want to ensure that your code handles every variant |
| /// explicitly, you need to override each method. (And you also need |
| /// to monitor future changes to `Visitor` in case a new method with a |
| /// new default implementation gets introduced.) |
| pub trait Visitor<'ast>: Sized { |
| fn visit_ident(&mut self, _ident: Ident) {} |
| fn visit_foreign_item(&mut self, i: &'ast ForeignItem) { |
| walk_foreign_item(self, i) |
| } |
| fn visit_item(&mut self, i: &'ast Item) { |
| walk_item(self, i) |
| } |
| fn visit_local(&mut self, l: &'ast Local) { |
| walk_local(self, l) |
| } |
| fn visit_block(&mut self, b: &'ast Block) { |
| walk_block(self, b) |
| } |
| fn visit_stmt(&mut self, s: &'ast Stmt) { |
| walk_stmt(self, s) |
| } |
| fn visit_param(&mut self, param: &'ast Param) { |
| walk_param(self, param) |
| } |
| fn visit_arm(&mut self, a: &'ast Arm) { |
| walk_arm(self, a) |
| } |
| fn visit_pat(&mut self, p: &'ast Pat) { |
| walk_pat(self, p) |
| } |
| fn visit_anon_const(&mut self, c: &'ast AnonConst) { |
| walk_anon_const(self, c) |
| } |
| fn visit_expr(&mut self, ex: &'ast Expr) { |
| walk_expr(self, ex) |
| } |
| /// This method is a hack to workaround unstable of `stmt_expr_attributes`. |
| /// It can be removed once that feature is stabilized. |
| fn visit_method_receiver_expr(&mut self, ex: &'ast Expr) { |
| self.visit_expr(ex) |
| } |
| fn visit_expr_post(&mut self, _ex: &'ast Expr) {} |
| fn visit_ty(&mut self, t: &'ast Ty) { |
| walk_ty(self, t) |
| } |
| fn visit_generic_param(&mut self, param: &'ast GenericParam) { |
| walk_generic_param(self, param) |
| } |
| fn visit_generics(&mut self, g: &'ast Generics) { |
| walk_generics(self, g) |
| } |
| fn visit_closure_binder(&mut self, b: &'ast ClosureBinder) { |
| walk_closure_binder(self, b) |
| } |
| fn visit_where_predicate(&mut self, p: &'ast WherePredicate) { |
| walk_where_predicate(self, p) |
| } |
| fn visit_fn(&mut self, fk: FnKind<'ast>, _: Span, _: NodeId) { |
| walk_fn(self, fk) |
| } |
| fn visit_assoc_item(&mut self, i: &'ast AssocItem, ctxt: AssocCtxt) { |
| walk_assoc_item(self, i, ctxt) |
| } |
| fn visit_trait_ref(&mut self, t: &'ast TraitRef) { |
| walk_trait_ref(self, t) |
| } |
| fn visit_param_bound(&mut self, bounds: &'ast GenericBound, _ctxt: BoundKind) { |
| walk_param_bound(self, bounds) |
| } |
| fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef) { |
| walk_poly_trait_ref(self, t) |
| } |
| fn visit_variant_data(&mut self, s: &'ast VariantData) { |
| walk_struct_def(self, s) |
| } |
| fn visit_field_def(&mut self, s: &'ast FieldDef) { |
| walk_field_def(self, s) |
| } |
| fn visit_enum_def(&mut self, enum_definition: &'ast EnumDef) { |
| walk_enum_def(self, enum_definition) |
| } |
| fn visit_variant(&mut self, v: &'ast Variant) { |
| walk_variant(self, v) |
| } |
| fn visit_variant_discr(&mut self, discr: &'ast AnonConst) { |
| self.visit_anon_const(discr); |
| } |
| fn visit_label(&mut self, label: &'ast Label) { |
| walk_label(self, label) |
| } |
| fn visit_lifetime(&mut self, lifetime: &'ast Lifetime, _: LifetimeCtxt) { |
| walk_lifetime(self, lifetime) |
| } |
| fn visit_mac_call(&mut self, mac: &'ast MacCall) { |
| walk_mac(self, mac) |
| } |
| fn visit_mac_def(&mut self, _mac: &'ast MacroDef, _id: NodeId) { |
| // Nothing to do |
| } |
| fn visit_path(&mut self, path: &'ast Path, _id: NodeId) { |
| walk_path(self, path) |
| } |
| fn visit_use_tree(&mut self, use_tree: &'ast UseTree, id: NodeId, _nested: bool) { |
| walk_use_tree(self, use_tree, id) |
| } |
| fn visit_path_segment(&mut self, path_segment: &'ast PathSegment) { |
| walk_path_segment(self, path_segment) |
| } |
| fn visit_generic_args(&mut self, generic_args: &'ast GenericArgs) { |
| walk_generic_args(self, generic_args) |
| } |
| fn visit_generic_arg(&mut self, generic_arg: &'ast GenericArg) { |
| walk_generic_arg(self, generic_arg) |
| } |
| fn visit_assoc_constraint(&mut self, constraint: &'ast AssocConstraint) { |
| walk_assoc_constraint(self, constraint) |
| } |
| fn visit_attribute(&mut self, attr: &'ast Attribute) { |
| walk_attribute(self, attr) |
| } |
| fn visit_vis(&mut self, vis: &'ast Visibility) { |
| walk_vis(self, vis) |
| } |
| fn visit_fn_ret_ty(&mut self, ret_ty: &'ast FnRetTy) { |
| walk_fn_ret_ty(self, ret_ty) |
| } |
| fn visit_fn_header(&mut self, _header: &'ast FnHeader) { |
| // Nothing to do |
| } |
| fn visit_expr_field(&mut self, f: &'ast ExprField) { |
| walk_expr_field(self, f) |
| } |
| fn visit_pat_field(&mut self, fp: &'ast PatField) { |
| walk_pat_field(self, fp) |
| } |
| fn visit_crate(&mut self, krate: &'ast Crate) { |
| walk_crate(self, krate) |
| } |
| fn visit_inline_asm(&mut self, asm: &'ast InlineAsm) { |
| walk_inline_asm(self, asm) |
| } |
| fn visit_format_args(&mut self, fmt: &'ast FormatArgs) { |
| walk_format_args(self, fmt) |
| } |
| fn visit_inline_asm_sym(&mut self, sym: &'ast InlineAsmSym) { |
| walk_inline_asm_sym(self, sym) |
| } |
| } |
| |
| #[macro_export] |
| macro_rules! walk_list { |
| ($visitor: expr, $method: ident, $list: expr $(, $($extra_args: expr),* )?) => { |
| { |
| #[allow(for_loops_over_fallibles)] |
| for elem in $list { |
| $visitor.$method(elem $(, $($extra_args,)* )?) |
| } |
| } |
| } |
| } |
| |
| pub fn walk_crate<'a, V: Visitor<'a>>(visitor: &mut V, krate: &'a Crate) { |
| walk_list!(visitor, visit_item, &krate.items); |
| walk_list!(visitor, visit_attribute, &krate.attrs); |
| } |
| |
| pub fn walk_local<'a, V: Visitor<'a>>(visitor: &mut V, local: &'a Local) { |
| for attr in local.attrs.iter() { |
| visitor.visit_attribute(attr); |
| } |
| visitor.visit_pat(&local.pat); |
| walk_list!(visitor, visit_ty, &local.ty); |
| if let Some((init, els)) = local.kind.init_else_opt() { |
| visitor.visit_expr(init); |
| walk_list!(visitor, visit_block, els); |
| } |
| } |
| |
| pub fn walk_label<'a, V: Visitor<'a>>(visitor: &mut V, label: &'a Label) { |
| visitor.visit_ident(label.ident); |
| } |
| |
| pub fn walk_lifetime<'a, V: Visitor<'a>>(visitor: &mut V, lifetime: &'a Lifetime) { |
| visitor.visit_ident(lifetime.ident); |
| } |
| |
| pub fn walk_poly_trait_ref<'a, V>(visitor: &mut V, trait_ref: &'a PolyTraitRef) |
| where |
| V: Visitor<'a>, |
| { |
| walk_list!(visitor, visit_generic_param, &trait_ref.bound_generic_params); |
| visitor.visit_trait_ref(&trait_ref.trait_ref); |
| } |
| |
| pub fn walk_trait_ref<'a, V: Visitor<'a>>(visitor: &mut V, trait_ref: &'a TraitRef) { |
| visitor.visit_path(&trait_ref.path, trait_ref.ref_id) |
| } |
| |
| pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) { |
| visitor.visit_vis(&item.vis); |
| visitor.visit_ident(item.ident); |
| match &item.kind { |
| ItemKind::ExternCrate(_) => {} |
| ItemKind::Use(use_tree) => visitor.visit_use_tree(use_tree, item.id, false), |
| ItemKind::Static(box StaticItem { ty, mutability: _, expr }) => { |
| visitor.visit_ty(ty); |
| walk_list!(visitor, visit_expr, expr); |
| } |
| ItemKind::Const(box ConstItem { defaultness: _, generics, ty, expr }) => { |
| visitor.visit_generics(generics); |
| visitor.visit_ty(ty); |
| walk_list!(visitor, visit_expr, expr); |
| } |
| ItemKind::Fn(box Fn { defaultness: _, generics, sig, body }) => { |
| let kind = |
| FnKind::Fn(FnCtxt::Free, item.ident, sig, &item.vis, generics, body.as_deref()); |
| visitor.visit_fn(kind, item.span, item.id) |
| } |
| ItemKind::Mod(_unsafety, mod_kind) => match mod_kind { |
| ModKind::Loaded(items, _inline, _inner_span) => { |
| walk_list!(visitor, visit_item, items) |
| } |
| ModKind::Unloaded => {} |
| }, |
| ItemKind::ForeignMod(foreign_module) => { |
| walk_list!(visitor, visit_foreign_item, &foreign_module.items); |
| } |
| ItemKind::GlobalAsm(asm) => visitor.visit_inline_asm(asm), |
| ItemKind::TyAlias(box TyAlias { generics, bounds, ty, .. }) => { |
| visitor.visit_generics(generics); |
| walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound); |
| walk_list!(visitor, visit_ty, ty); |
| } |
| ItemKind::Enum(enum_definition, generics) => { |
| visitor.visit_generics(generics); |
| visitor.visit_enum_def(enum_definition) |
| } |
| ItemKind::Impl(box Impl { |
| defaultness: _, |
| unsafety: _, |
| generics, |
| constness: _, |
| polarity: _, |
| of_trait, |
| self_ty, |
| items, |
| }) => { |
| visitor.visit_generics(generics); |
| walk_list!(visitor, visit_trait_ref, of_trait); |
| visitor.visit_ty(self_ty); |
| walk_list!(visitor, visit_assoc_item, items, AssocCtxt::Impl); |
| } |
| ItemKind::Struct(struct_definition, generics) |
| | ItemKind::Union(struct_definition, generics) => { |
| visitor.visit_generics(generics); |
| visitor.visit_variant_data(struct_definition); |
| } |
| ItemKind::Trait(box Trait { unsafety: _, is_auto: _, generics, bounds, items }) => { |
| visitor.visit_generics(generics); |
| walk_list!(visitor, visit_param_bound, bounds, BoundKind::SuperTraits); |
| walk_list!(visitor, visit_assoc_item, items, AssocCtxt::Trait); |
| } |
| ItemKind::TraitAlias(generics, bounds) => { |
| visitor.visit_generics(generics); |
| walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound); |
| } |
| ItemKind::MacCall(mac) => visitor.visit_mac_call(mac), |
| ItemKind::MacroDef(ts) => visitor.visit_mac_def(ts, item.id), |
| } |
| walk_list!(visitor, visit_attribute, &item.attrs); |
| } |
| |
| pub fn walk_enum_def<'a, V: Visitor<'a>>(visitor: &mut V, enum_definition: &'a EnumDef) { |
| walk_list!(visitor, visit_variant, &enum_definition.variants); |
| } |
| |
| pub fn walk_variant<'a, V: Visitor<'a>>(visitor: &mut V, variant: &'a Variant) |
| where |
| V: Visitor<'a>, |
| { |
| visitor.visit_ident(variant.ident); |
| visitor.visit_vis(&variant.vis); |
| visitor.visit_variant_data(&variant.data); |
| walk_list!(visitor, visit_variant_discr, &variant.disr_expr); |
| walk_list!(visitor, visit_attribute, &variant.attrs); |
| } |
| |
| pub fn walk_expr_field<'a, V: Visitor<'a>>(visitor: &mut V, f: &'a ExprField) { |
| visitor.visit_expr(&f.expr); |
| visitor.visit_ident(f.ident); |
| walk_list!(visitor, visit_attribute, f.attrs.iter()); |
| } |
| |
| pub fn walk_pat_field<'a, V: Visitor<'a>>(visitor: &mut V, fp: &'a PatField) { |
| visitor.visit_ident(fp.ident); |
| visitor.visit_pat(&fp.pat); |
| walk_list!(visitor, visit_attribute, fp.attrs.iter()); |
| } |
| |
| pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) { |
| match &typ.kind { |
| TyKind::Slice(ty) | TyKind::Paren(ty) => visitor.visit_ty(ty), |
| TyKind::Ptr(mutable_type) => visitor.visit_ty(&mutable_type.ty), |
| TyKind::Ref(opt_lifetime, mutable_type) => { |
| walk_list!(visitor, visit_lifetime, opt_lifetime, LifetimeCtxt::Ref); |
| visitor.visit_ty(&mutable_type.ty) |
| } |
| TyKind::Tup(tuple_element_types) => { |
| walk_list!(visitor, visit_ty, tuple_element_types); |
| } |
| TyKind::BareFn(function_declaration) => { |
| walk_list!(visitor, visit_generic_param, &function_declaration.generic_params); |
| walk_fn_decl(visitor, &function_declaration.decl); |
| } |
| TyKind::Path(maybe_qself, path) => { |
| if let Some(qself) = maybe_qself { |
| visitor.visit_ty(&qself.ty); |
| } |
| visitor.visit_path(path, typ.id); |
| } |
| TyKind::Array(ty, length) => { |
| visitor.visit_ty(ty); |
| visitor.visit_anon_const(length) |
| } |
| TyKind::TraitObject(bounds, ..) => { |
| walk_list!(visitor, visit_param_bound, bounds, BoundKind::TraitObject); |
| } |
| TyKind::ImplTrait(_, bounds) => { |
| walk_list!(visitor, visit_param_bound, bounds, BoundKind::Impl); |
| } |
| TyKind::Typeof(expression) => visitor.visit_anon_const(expression), |
| TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => {} |
| TyKind::MacCall(mac) => visitor.visit_mac_call(mac), |
| TyKind::Never | TyKind::CVarArgs => {} |
| } |
| } |
| |
| pub fn walk_path<'a, V: Visitor<'a>>(visitor: &mut V, path: &'a Path) { |
| for segment in &path.segments { |
| visitor.visit_path_segment(segment); |
| } |
| } |
| |
| pub fn walk_use_tree<'a, V: Visitor<'a>>(visitor: &mut V, use_tree: &'a UseTree, id: NodeId) { |
| visitor.visit_path(&use_tree.prefix, id); |
| match &use_tree.kind { |
| UseTreeKind::Simple(rename) => { |
| // The extra IDs are handled during HIR lowering. |
| if let &Some(rename) = rename { |
| visitor.visit_ident(rename); |
| } |
| } |
| UseTreeKind::Glob => {} |
| UseTreeKind::Nested(use_trees) => { |
| for &(ref nested_tree, nested_id) in use_trees { |
| visitor.visit_use_tree(nested_tree, nested_id, true); |
| } |
| } |
| } |
| } |
| |
| pub fn walk_path_segment<'a, V: Visitor<'a>>(visitor: &mut V, segment: &'a PathSegment) { |
| visitor.visit_ident(segment.ident); |
| if let Some(args) = &segment.args { |
| visitor.visit_generic_args(args); |
| } |
| } |
| |
| pub fn walk_generic_args<'a, V>(visitor: &mut V, generic_args: &'a GenericArgs) |
| where |
| V: Visitor<'a>, |
| { |
| match generic_args { |
| GenericArgs::AngleBracketed(data) => { |
| for arg in &data.args { |
| match arg { |
| AngleBracketedArg::Arg(a) => visitor.visit_generic_arg(a), |
| AngleBracketedArg::Constraint(c) => visitor.visit_assoc_constraint(c), |
| } |
| } |
| } |
| GenericArgs::Parenthesized(data) => { |
| walk_list!(visitor, visit_ty, &data.inputs); |
| walk_fn_ret_ty(visitor, &data.output); |
| } |
| } |
| } |
| |
| pub fn walk_generic_arg<'a, V>(visitor: &mut V, generic_arg: &'a GenericArg) |
| where |
| V: Visitor<'a>, |
| { |
| match generic_arg { |
| GenericArg::Lifetime(lt) => visitor.visit_lifetime(lt, LifetimeCtxt::GenericArg), |
| GenericArg::Type(ty) => visitor.visit_ty(ty), |
| GenericArg::Const(ct) => visitor.visit_anon_const(ct), |
| } |
| } |
| |
| pub fn walk_assoc_constraint<'a, V: Visitor<'a>>(visitor: &mut V, constraint: &'a AssocConstraint) { |
| visitor.visit_ident(constraint.ident); |
| if let Some(gen_args) = &constraint.gen_args { |
| visitor.visit_generic_args(gen_args); |
| } |
| match &constraint.kind { |
| AssocConstraintKind::Equality { term } => match term { |
| Term::Ty(ty) => visitor.visit_ty(ty), |
| Term::Const(c) => visitor.visit_anon_const(c), |
| }, |
| AssocConstraintKind::Bound { bounds } => { |
| walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound); |
| } |
| } |
| } |
| |
| pub fn walk_pat<'a, V: Visitor<'a>>(visitor: &mut V, pattern: &'a Pat) { |
| match &pattern.kind { |
| PatKind::TupleStruct(opt_qself, path, elems) => { |
| if let Some(qself) = opt_qself { |
| visitor.visit_ty(&qself.ty); |
| } |
| visitor.visit_path(path, pattern.id); |
| walk_list!(visitor, visit_pat, elems); |
| } |
| PatKind::Path(opt_qself, path) => { |
| if let Some(qself) = opt_qself { |
| visitor.visit_ty(&qself.ty); |
| } |
| visitor.visit_path(path, pattern.id) |
| } |
| PatKind::Struct(opt_qself, path, fields, _) => { |
| if let Some(qself) = opt_qself { |
| visitor.visit_ty(&qself.ty); |
| } |
| visitor.visit_path(path, pattern.id); |
| walk_list!(visitor, visit_pat_field, fields); |
| } |
| PatKind::Box(subpattern) | PatKind::Ref(subpattern, _) | PatKind::Paren(subpattern) => { |
| visitor.visit_pat(subpattern) |
| } |
| PatKind::Ident(_, ident, optional_subpattern) => { |
| visitor.visit_ident(*ident); |
| walk_list!(visitor, visit_pat, optional_subpattern); |
| } |
| PatKind::Lit(expression) => visitor.visit_expr(expression), |
| PatKind::Range(lower_bound, upper_bound, _) => { |
| walk_list!(visitor, visit_expr, lower_bound); |
| walk_list!(visitor, visit_expr, upper_bound); |
| } |
| PatKind::Wild | PatKind::Rest => {} |
| PatKind::Tuple(elems) | PatKind::Slice(elems) | PatKind::Or(elems) => { |
| walk_list!(visitor, visit_pat, elems); |
| } |
| PatKind::MacCall(mac) => visitor.visit_mac_call(mac), |
| } |
| } |
| |
| pub fn walk_foreign_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a ForeignItem) { |
| let &Item { id, span, ident, ref vis, ref attrs, ref kind, tokens: _ } = item; |
| visitor.visit_vis(vis); |
| visitor.visit_ident(ident); |
| walk_list!(visitor, visit_attribute, attrs); |
| match kind { |
| ForeignItemKind::Static(ty, _, expr) => { |
| visitor.visit_ty(ty); |
| walk_list!(visitor, visit_expr, expr); |
| } |
| ForeignItemKind::Fn(box Fn { defaultness: _, generics, sig, body }) => { |
| let kind = FnKind::Fn(FnCtxt::Foreign, ident, sig, vis, generics, body.as_deref()); |
| visitor.visit_fn(kind, span, id); |
| } |
| ForeignItemKind::TyAlias(box TyAlias { generics, bounds, ty, .. }) => { |
| visitor.visit_generics(generics); |
| walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound); |
| walk_list!(visitor, visit_ty, ty); |
| } |
| ForeignItemKind::MacCall(mac) => { |
| visitor.visit_mac_call(mac); |
| } |
| } |
| } |
| |
| pub fn walk_param_bound<'a, V: Visitor<'a>>(visitor: &mut V, bound: &'a GenericBound) { |
| match bound { |
| GenericBound::Trait(typ, _modifier) => visitor.visit_poly_trait_ref(typ), |
| GenericBound::Outlives(lifetime) => visitor.visit_lifetime(lifetime, LifetimeCtxt::Bound), |
| } |
| } |
| |
| pub fn walk_generic_param<'a, V: Visitor<'a>>(visitor: &mut V, param: &'a GenericParam) { |
| visitor.visit_ident(param.ident); |
| walk_list!(visitor, visit_attribute, param.attrs.iter()); |
| walk_list!(visitor, visit_param_bound, ¶m.bounds, BoundKind::Bound); |
| match ¶m.kind { |
| GenericParamKind::Lifetime => (), |
| GenericParamKind::Type { default } => walk_list!(visitor, visit_ty, default), |
| GenericParamKind::Const { ty, default, .. } => { |
| visitor.visit_ty(ty); |
| if let Some(default) = default { |
| visitor.visit_anon_const(default); |
| } |
| } |
| } |
| } |
| |
| pub fn walk_generics<'a, V: Visitor<'a>>(visitor: &mut V, generics: &'a Generics) { |
| walk_list!(visitor, visit_generic_param, &generics.params); |
| walk_list!(visitor, visit_where_predicate, &generics.where_clause.predicates); |
| } |
| |
| pub fn walk_closure_binder<'a, V: Visitor<'a>>(visitor: &mut V, binder: &'a ClosureBinder) { |
| match binder { |
| ClosureBinder::NotPresent => {} |
| ClosureBinder::For { generic_params, span: _ } => { |
| walk_list!(visitor, visit_generic_param, generic_params) |
| } |
| } |
| } |
| |
| pub fn walk_where_predicate<'a, V: Visitor<'a>>(visitor: &mut V, predicate: &'a WherePredicate) { |
| match predicate { |
| WherePredicate::BoundPredicate(WhereBoundPredicate { |
| bounded_ty, |
| bounds, |
| bound_generic_params, |
| .. |
| }) => { |
| visitor.visit_ty(bounded_ty); |
| walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound); |
| walk_list!(visitor, visit_generic_param, bound_generic_params); |
| } |
| WherePredicate::RegionPredicate(WhereRegionPredicate { lifetime, bounds, .. }) => { |
| visitor.visit_lifetime(lifetime, LifetimeCtxt::Bound); |
| walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound); |
| } |
| WherePredicate::EqPredicate(WhereEqPredicate { lhs_ty, rhs_ty, .. }) => { |
| visitor.visit_ty(lhs_ty); |
| visitor.visit_ty(rhs_ty); |
| } |
| } |
| } |
| |
| pub fn walk_fn_ret_ty<'a, V: Visitor<'a>>(visitor: &mut V, ret_ty: &'a FnRetTy) { |
| if let FnRetTy::Ty(output_ty) = ret_ty { |
| visitor.visit_ty(output_ty) |
| } |
| } |
| |
| pub fn walk_fn_decl<'a, V: Visitor<'a>>(visitor: &mut V, function_declaration: &'a FnDecl) { |
| for param in &function_declaration.inputs { |
| visitor.visit_param(param); |
| } |
| visitor.visit_fn_ret_ty(&function_declaration.output); |
| } |
| |
| pub fn walk_fn<'a, V: Visitor<'a>>(visitor: &mut V, kind: FnKind<'a>) { |
| match kind { |
| FnKind::Fn(_, _, sig, _, generics, body) => { |
| visitor.visit_generics(generics); |
| visitor.visit_fn_header(&sig.header); |
| walk_fn_decl(visitor, &sig.decl); |
| walk_list!(visitor, visit_block, body); |
| } |
| FnKind::Closure(binder, decl, body) => { |
| visitor.visit_closure_binder(binder); |
| walk_fn_decl(visitor, decl); |
| visitor.visit_expr(body); |
| } |
| } |
| } |
| |
| pub fn walk_assoc_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a AssocItem, ctxt: AssocCtxt) { |
| let &Item { id, span, ident, ref vis, ref attrs, ref kind, tokens: _ } = item; |
| visitor.visit_vis(vis); |
| visitor.visit_ident(ident); |
| walk_list!(visitor, visit_attribute, attrs); |
| match kind { |
| AssocItemKind::Const(box ConstItem { defaultness: _, generics, ty, expr }) => { |
| visitor.visit_generics(generics); |
| visitor.visit_ty(ty); |
| walk_list!(visitor, visit_expr, expr); |
| } |
| AssocItemKind::Fn(box Fn { defaultness: _, generics, sig, body }) => { |
| let kind = FnKind::Fn(FnCtxt::Assoc(ctxt), ident, sig, vis, generics, body.as_deref()); |
| visitor.visit_fn(kind, span, id); |
| } |
| AssocItemKind::Type(box TyAlias { generics, bounds, ty, .. }) => { |
| visitor.visit_generics(generics); |
| walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound); |
| walk_list!(visitor, visit_ty, ty); |
| } |
| AssocItemKind::MacCall(mac) => { |
| visitor.visit_mac_call(mac); |
| } |
| } |
| } |
| |
| pub fn walk_struct_def<'a, V: Visitor<'a>>(visitor: &mut V, struct_definition: &'a VariantData) { |
| walk_list!(visitor, visit_field_def, struct_definition.fields()); |
| } |
| |
| pub fn walk_field_def<'a, V: Visitor<'a>>(visitor: &mut V, field: &'a FieldDef) { |
| visitor.visit_vis(&field.vis); |
| if let Some(ident) = field.ident { |
| visitor.visit_ident(ident); |
| } |
| visitor.visit_ty(&field.ty); |
| walk_list!(visitor, visit_attribute, &field.attrs); |
| } |
| |
| pub fn walk_block<'a, V: Visitor<'a>>(visitor: &mut V, block: &'a Block) { |
| walk_list!(visitor, visit_stmt, &block.stmts); |
| } |
| |
| pub fn walk_stmt<'a, V: Visitor<'a>>(visitor: &mut V, statement: &'a Stmt) { |
| match &statement.kind { |
| StmtKind::Local(local) => visitor.visit_local(local), |
| StmtKind::Item(item) => visitor.visit_item(item), |
| StmtKind::Expr(expr) | StmtKind::Semi(expr) => visitor.visit_expr(expr), |
| StmtKind::Empty => {} |
| StmtKind::MacCall(mac) => { |
| let MacCallStmt { mac, attrs, style: _, tokens: _ } = &**mac; |
| visitor.visit_mac_call(mac); |
| for attr in attrs.iter() { |
| visitor.visit_attribute(attr); |
| } |
| } |
| } |
| } |
| |
| pub fn walk_mac<'a, V: Visitor<'a>>(visitor: &mut V, mac: &'a MacCall) { |
| visitor.visit_path(&mac.path, DUMMY_NODE_ID); |
| } |
| |
| pub fn walk_anon_const<'a, V: Visitor<'a>>(visitor: &mut V, constant: &'a AnonConst) { |
| visitor.visit_expr(&constant.value); |
| } |
| |
| pub fn walk_inline_asm<'a, V: Visitor<'a>>(visitor: &mut V, asm: &'a InlineAsm) { |
| for (op, _) in &asm.operands { |
| match op { |
| InlineAsmOperand::In { expr, .. } |
| | InlineAsmOperand::Out { expr: Some(expr), .. } |
| | InlineAsmOperand::InOut { expr, .. } => visitor.visit_expr(expr), |
| InlineAsmOperand::Out { expr: None, .. } => {} |
| InlineAsmOperand::SplitInOut { in_expr, out_expr, .. } => { |
| visitor.visit_expr(in_expr); |
| if let Some(out_expr) = out_expr { |
| visitor.visit_expr(out_expr); |
| } |
| } |
| InlineAsmOperand::Const { anon_const, .. } => visitor.visit_anon_const(anon_const), |
| InlineAsmOperand::Sym { sym } => visitor.visit_inline_asm_sym(sym), |
| } |
| } |
| } |
| |
| pub fn walk_inline_asm_sym<'a, V: Visitor<'a>>(visitor: &mut V, sym: &'a InlineAsmSym) { |
| if let Some(qself) = &sym.qself { |
| visitor.visit_ty(&qself.ty); |
| } |
| visitor.visit_path(&sym.path, sym.id); |
| } |
| |
| pub fn walk_format_args<'a, V: Visitor<'a>>(visitor: &mut V, fmt: &'a FormatArgs) { |
| for arg in fmt.arguments.all_args() { |
| if let FormatArgumentKind::Named(name) = arg.kind { |
| visitor.visit_ident(name); |
| } |
| visitor.visit_expr(&arg.expr); |
| } |
| } |
| |
| pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) { |
| walk_list!(visitor, visit_attribute, expression.attrs.iter()); |
| |
| match &expression.kind { |
| ExprKind::Array(subexpressions) => { |
| walk_list!(visitor, visit_expr, subexpressions); |
| } |
| ExprKind::ConstBlock(anon_const) => visitor.visit_anon_const(anon_const), |
| ExprKind::Repeat(element, count) => { |
| visitor.visit_expr(element); |
| visitor.visit_anon_const(count) |
| } |
| ExprKind::Struct(se) => { |
| if let Some(qself) = &se.qself { |
| visitor.visit_ty(&qself.ty); |
| } |
| visitor.visit_path(&se.path, expression.id); |
| walk_list!(visitor, visit_expr_field, &se.fields); |
| match &se.rest { |
| StructRest::Base(expr) => visitor.visit_expr(expr), |
| StructRest::Rest(_span) => {} |
| StructRest::None => {} |
| } |
| } |
| ExprKind::Tup(subexpressions) => { |
| walk_list!(visitor, visit_expr, subexpressions); |
| } |
| ExprKind::Call(callee_expression, arguments) => { |
| visitor.visit_expr(callee_expression); |
| walk_list!(visitor, visit_expr, arguments); |
| } |
| ExprKind::MethodCall(box MethodCall { seg, receiver, args, span: _ }) => { |
| visitor.visit_path_segment(seg); |
| visitor.visit_expr(receiver); |
| walk_list!(visitor, visit_expr, args); |
| } |
| ExprKind::Binary(_, left_expression, right_expression) => { |
| visitor.visit_expr(left_expression); |
| visitor.visit_expr(right_expression) |
| } |
| ExprKind::AddrOf(_, _, subexpression) | ExprKind::Unary(_, subexpression) => { |
| visitor.visit_expr(subexpression) |
| } |
| ExprKind::Cast(subexpression, typ) | ExprKind::Type(subexpression, typ) => { |
| visitor.visit_expr(subexpression); |
| visitor.visit_ty(typ) |
| } |
| ExprKind::Let(pat, expr, _) => { |
| visitor.visit_pat(pat); |
| visitor.visit_expr(expr); |
| } |
| ExprKind::If(head_expression, if_block, optional_else) => { |
| visitor.visit_expr(head_expression); |
| visitor.visit_block(if_block); |
| walk_list!(visitor, visit_expr, optional_else); |
| } |
| ExprKind::While(subexpression, block, opt_label) => { |
| walk_list!(visitor, visit_label, opt_label); |
| visitor.visit_expr(subexpression); |
| visitor.visit_block(block); |
| } |
| ExprKind::ForLoop(pattern, subexpression, block, opt_label) => { |
| walk_list!(visitor, visit_label, opt_label); |
| visitor.visit_pat(pattern); |
| visitor.visit_expr(subexpression); |
| visitor.visit_block(block); |
| } |
| ExprKind::Loop(block, opt_label, _) => { |
| walk_list!(visitor, visit_label, opt_label); |
| visitor.visit_block(block); |
| } |
| ExprKind::Match(subexpression, arms) => { |
| visitor.visit_expr(subexpression); |
| walk_list!(visitor, visit_arm, arms); |
| } |
| ExprKind::Closure(box Closure { |
| binder, |
| capture_clause: _, |
| asyncness: _, |
| constness: _, |
| movability: _, |
| fn_decl, |
| body, |
| fn_decl_span: _, |
| fn_arg_span: _, |
| }) => { |
| visitor.visit_fn(FnKind::Closure(binder, fn_decl, body), expression.span, expression.id) |
| } |
| ExprKind::Block(block, opt_label) => { |
| walk_list!(visitor, visit_label, opt_label); |
| visitor.visit_block(block); |
| } |
| ExprKind::Async(_, body) => { |
| visitor.visit_block(body); |
| } |
| ExprKind::Await(expr, _) => visitor.visit_expr(expr), |
| ExprKind::Assign(lhs, rhs, _) => { |
| visitor.visit_expr(lhs); |
| visitor.visit_expr(rhs); |
| } |
| ExprKind::AssignOp(_, left_expression, right_expression) => { |
| visitor.visit_expr(left_expression); |
| visitor.visit_expr(right_expression); |
| } |
| ExprKind::Field(subexpression, ident) => { |
| visitor.visit_expr(subexpression); |
| visitor.visit_ident(*ident); |
| } |
| ExprKind::Index(main_expression, index_expression, _) => { |
| visitor.visit_expr(main_expression); |
| visitor.visit_expr(index_expression) |
| } |
| ExprKind::Range(start, end, _) => { |
| walk_list!(visitor, visit_expr, start); |
| walk_list!(visitor, visit_expr, end); |
| } |
| ExprKind::Underscore => {} |
| ExprKind::Path(maybe_qself, path) => { |
| if let Some(qself) = maybe_qself { |
| visitor.visit_ty(&qself.ty); |
| } |
| visitor.visit_path(path, expression.id) |
| } |
| ExprKind::Break(opt_label, opt_expr) => { |
| walk_list!(visitor, visit_label, opt_label); |
| walk_list!(visitor, visit_expr, opt_expr); |
| } |
| ExprKind::Continue(opt_label) => { |
| walk_list!(visitor, visit_label, opt_label); |
| } |
| ExprKind::Ret(optional_expression) => { |
| walk_list!(visitor, visit_expr, optional_expression); |
| } |
| ExprKind::Yeet(optional_expression) => { |
| walk_list!(visitor, visit_expr, optional_expression); |
| } |
| ExprKind::Become(expr) => visitor.visit_expr(expr), |
| ExprKind::MacCall(mac) => visitor.visit_mac_call(mac), |
| ExprKind::Paren(subexpression) => visitor.visit_expr(subexpression), |
| ExprKind::InlineAsm(asm) => visitor.visit_inline_asm(asm), |
| ExprKind::FormatArgs(f) => visitor.visit_format_args(f), |
| ExprKind::OffsetOf(container, fields) => { |
| visitor.visit_ty(container); |
| for &field in fields { |
| visitor.visit_ident(field); |
| } |
| } |
| ExprKind::Yield(optional_expression) => { |
| walk_list!(visitor, visit_expr, optional_expression); |
| } |
| ExprKind::Try(subexpression) => visitor.visit_expr(subexpression), |
| ExprKind::TryBlock(body) => visitor.visit_block(body), |
| ExprKind::Lit(_) | ExprKind::IncludedBytes(..) | ExprKind::Err => {} |
| } |
| |
| visitor.visit_expr_post(expression) |
| } |
| |
| pub fn walk_param<'a, V: Visitor<'a>>(visitor: &mut V, param: &'a Param) { |
| walk_list!(visitor, visit_attribute, param.attrs.iter()); |
| visitor.visit_pat(¶m.pat); |
| visitor.visit_ty(¶m.ty); |
| } |
| |
| pub fn walk_arm<'a, V: Visitor<'a>>(visitor: &mut V, arm: &'a Arm) { |
| visitor.visit_pat(&arm.pat); |
| walk_list!(visitor, visit_expr, &arm.guard); |
| visitor.visit_expr(&arm.body); |
| walk_list!(visitor, visit_attribute, &arm.attrs); |
| } |
| |
| pub fn walk_vis<'a, V: Visitor<'a>>(visitor: &mut V, vis: &'a Visibility) { |
| if let VisibilityKind::Restricted { ref path, id, shorthand: _ } = vis.kind { |
| visitor.visit_path(path, id); |
| } |
| } |
| |
| pub fn walk_attribute<'a, V: Visitor<'a>>(visitor: &mut V, attr: &'a Attribute) { |
| match &attr.kind { |
| AttrKind::Normal(normal) => walk_attr_args(visitor, &normal.item.args), |
| AttrKind::DocComment(..) => {} |
| } |
| } |
| |
| pub fn walk_attr_args<'a, V: Visitor<'a>>(visitor: &mut V, args: &'a AttrArgs) { |
| match args { |
| AttrArgs::Empty => {} |
| AttrArgs::Delimited(_) => {} |
| AttrArgs::Eq(_eq_span, AttrArgsEq::Ast(expr)) => visitor.visit_expr(expr), |
| AttrArgs::Eq(_, AttrArgsEq::Hir(lit)) => { |
| unreachable!("in literal form when walking mac args eq: {:?}", lit) |
| } |
| } |
| } |