968 lines
35 KiB
Rust
968 lines
35 KiB
Rust
//! AST walker. Each overridden visit method has full control over what
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//! happens with its node, it can do its own traversal of the node's children,
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//! call `visit::walk_*` to apply the default traversal algorithm, or prevent
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//! deeper traversal by doing nothing.
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//!
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//! Note: it is an important invariant that the default visitor walks the body
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//! of a function in "execution order" (more concretely, reverse post-order
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//! with respect to the CFG implied by the AST), meaning that if AST node A may
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//! execute before AST node B, then A is visited first. The borrow checker in
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//! particular relies on this property.
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//!
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//! Note: walking an AST before macro expansion is probably a bad idea. For
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//! instance, a walker looking for item names in a module will miss all of
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//! those that are created by the expansion of a macro.
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use crate::{ast::*, StaticItem};
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use rustc_span::symbol::Ident;
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use rustc_span::Span;
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#[derive(Copy, Clone, Debug, PartialEq)]
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pub enum AssocCtxt {
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Trait,
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Impl,
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}
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#[derive(Copy, Clone, Debug, PartialEq)]
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pub enum FnCtxt {
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Free,
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Foreign,
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Assoc(AssocCtxt),
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}
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#[derive(Copy, Clone, Debug)]
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pub enum BoundKind {
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/// Trait bounds in generics bounds and type/trait alias.
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/// E.g., `<T: Bound>`, `type A: Bound`, or `where T: Bound`.
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Bound,
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/// Trait bounds in `impl` type.
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/// E.g., `type Foo = impl Bound1 + Bound2 + Bound3`.
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Impl,
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/// Trait bounds in trait object type.
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/// E.g., `dyn Bound1 + Bound2 + Bound3`.
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TraitObject,
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/// Super traits of a trait.
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/// E.g., `trait A: B`
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SuperTraits,
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}
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#[derive(Copy, Clone, Debug)]
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pub enum FnKind<'a> {
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/// E.g., `fn foo()`, `fn foo(&self)`, or `extern "Abi" fn foo()`.
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Fn(FnCtxt, Ident, &'a FnSig, &'a Visibility, &'a Generics, Option<&'a Block>),
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/// E.g., `|x, y| body`.
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Closure(&'a ClosureBinder, &'a FnDecl, &'a Expr),
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}
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impl<'a> FnKind<'a> {
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pub fn header(&self) -> Option<&'a FnHeader> {
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match *self {
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FnKind::Fn(_, _, sig, _, _, _) => Some(&sig.header),
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FnKind::Closure(_, _, _) => None,
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}
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}
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pub fn ident(&self) -> Option<&Ident> {
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match self {
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FnKind::Fn(_, ident, ..) => Some(ident),
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_ => None,
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}
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}
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pub fn decl(&self) -> &'a FnDecl {
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match self {
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FnKind::Fn(_, _, sig, _, _, _) => &sig.decl,
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FnKind::Closure(_, decl, _) => decl,
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}
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}
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pub fn ctxt(&self) -> Option<FnCtxt> {
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match self {
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FnKind::Fn(ctxt, ..) => Some(*ctxt),
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FnKind::Closure(..) => None,
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}
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}
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}
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#[derive(Copy, Clone, Debug)]
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pub enum LifetimeCtxt {
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/// Appears in a reference type.
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Ref,
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/// Appears as a bound on a type or another lifetime.
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Bound,
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/// Appears as a generic argument.
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GenericArg,
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}
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/// Each method of the `Visitor` trait is a hook to be potentially
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/// overridden. Each method's default implementation recursively visits
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/// the substructure of the input via the corresponding `walk` method;
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/// e.g., the `visit_item` method by default calls `visit::walk_item`.
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///
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/// If you want to ensure that your code handles every variant
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/// explicitly, you need to override each method. (And you also need
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/// to monitor future changes to `Visitor` in case a new method with a
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/// new default implementation gets introduced.)
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pub trait Visitor<'ast>: Sized {
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fn visit_ident(&mut self, _ident: Ident) {}
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fn visit_foreign_item(&mut self, i: &'ast ForeignItem) {
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walk_foreign_item(self, i)
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}
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fn visit_item(&mut self, i: &'ast Item) {
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walk_item(self, i)
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}
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fn visit_local(&mut self, l: &'ast Local) {
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walk_local(self, l)
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}
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fn visit_block(&mut self, b: &'ast Block) {
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walk_block(self, b)
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}
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fn visit_stmt(&mut self, s: &'ast Stmt) {
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walk_stmt(self, s)
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}
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fn visit_param(&mut self, param: &'ast Param) {
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walk_param(self, param)
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}
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fn visit_arm(&mut self, a: &'ast Arm) {
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walk_arm(self, a)
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}
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fn visit_pat(&mut self, p: &'ast Pat) {
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walk_pat(self, p)
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}
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fn visit_anon_const(&mut self, c: &'ast AnonConst) {
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walk_anon_const(self, c)
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}
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fn visit_expr(&mut self, ex: &'ast Expr) {
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walk_expr(self, ex)
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}
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/// This method is a hack to workaround unstable of `stmt_expr_attributes`.
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/// It can be removed once that feature is stabilized.
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fn visit_method_receiver_expr(&mut self, ex: &'ast Expr) {
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self.visit_expr(ex)
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}
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fn visit_expr_post(&mut self, _ex: &'ast Expr) {}
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fn visit_ty(&mut self, t: &'ast Ty) {
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walk_ty(self, t)
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}
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fn visit_generic_param(&mut self, param: &'ast GenericParam) {
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walk_generic_param(self, param)
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}
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fn visit_generics(&mut self, g: &'ast Generics) {
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walk_generics(self, g)
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}
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fn visit_closure_binder(&mut self, b: &'ast ClosureBinder) {
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walk_closure_binder(self, b)
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}
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fn visit_where_predicate(&mut self, p: &'ast WherePredicate) {
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walk_where_predicate(self, p)
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}
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fn visit_fn(&mut self, fk: FnKind<'ast>, _: Span, _: NodeId) {
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walk_fn(self, fk)
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}
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fn visit_assoc_item(&mut self, i: &'ast AssocItem, ctxt: AssocCtxt) {
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walk_assoc_item(self, i, ctxt)
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}
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fn visit_trait_ref(&mut self, t: &'ast TraitRef) {
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walk_trait_ref(self, t)
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}
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fn visit_param_bound(&mut self, bounds: &'ast GenericBound, _ctxt: BoundKind) {
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walk_param_bound(self, bounds)
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}
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fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef) {
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walk_poly_trait_ref(self, t)
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}
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fn visit_variant_data(&mut self, s: &'ast VariantData) {
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walk_struct_def(self, s)
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}
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fn visit_field_def(&mut self, s: &'ast FieldDef) {
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walk_field_def(self, s)
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}
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fn visit_enum_def(&mut self, enum_definition: &'ast EnumDef) {
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walk_enum_def(self, enum_definition)
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}
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fn visit_variant(&mut self, v: &'ast Variant) {
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walk_variant(self, v)
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}
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fn visit_variant_discr(&mut self, discr: &'ast AnonConst) {
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self.visit_anon_const(discr);
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}
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fn visit_label(&mut self, label: &'ast Label) {
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walk_label(self, label)
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}
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fn visit_lifetime(&mut self, lifetime: &'ast Lifetime, _: LifetimeCtxt) {
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walk_lifetime(self, lifetime)
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}
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fn visit_mac_call(&mut self, mac: &'ast MacCall) {
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walk_mac(self, mac)
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}
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fn visit_mac_def(&mut self, _mac: &'ast MacroDef, _id: NodeId) {
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// Nothing to do
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}
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fn visit_path(&mut self, path: &'ast Path, _id: NodeId) {
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walk_path(self, path)
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}
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fn visit_use_tree(&mut self, use_tree: &'ast UseTree, id: NodeId, _nested: bool) {
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walk_use_tree(self, use_tree, id)
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}
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fn visit_path_segment(&mut self, path_segment: &'ast PathSegment) {
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walk_path_segment(self, path_segment)
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}
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fn visit_generic_args(&mut self, generic_args: &'ast GenericArgs) {
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walk_generic_args(self, generic_args)
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}
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fn visit_generic_arg(&mut self, generic_arg: &'ast GenericArg) {
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walk_generic_arg(self, generic_arg)
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}
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fn visit_assoc_constraint(&mut self, constraint: &'ast AssocConstraint) {
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walk_assoc_constraint(self, constraint)
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}
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fn visit_attribute(&mut self, attr: &'ast Attribute) {
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walk_attribute(self, attr)
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}
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fn visit_vis(&mut self, vis: &'ast Visibility) {
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walk_vis(self, vis)
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}
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fn visit_fn_ret_ty(&mut self, ret_ty: &'ast FnRetTy) {
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walk_fn_ret_ty(self, ret_ty)
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}
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fn visit_fn_header(&mut self, _header: &'ast FnHeader) {
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// Nothing to do
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}
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fn visit_expr_field(&mut self, f: &'ast ExprField) {
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walk_expr_field(self, f)
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}
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fn visit_pat_field(&mut self, fp: &'ast PatField) {
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walk_pat_field(self, fp)
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}
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fn visit_crate(&mut self, krate: &'ast Crate) {
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walk_crate(self, krate)
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}
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fn visit_inline_asm(&mut self, asm: &'ast InlineAsm) {
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walk_inline_asm(self, asm)
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}
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fn visit_format_args(&mut self, fmt: &'ast FormatArgs) {
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walk_format_args(self, fmt)
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}
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fn visit_inline_asm_sym(&mut self, sym: &'ast InlineAsmSym) {
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walk_inline_asm_sym(self, sym)
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}
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}
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#[macro_export]
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macro_rules! walk_list {
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($visitor: expr, $method: ident, $list: expr $(, $($extra_args: expr),* )?) => {
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{
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#[allow(for_loops_over_fallibles)]
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for elem in $list {
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$visitor.$method(elem $(, $($extra_args,)* )?)
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}
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}
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}
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}
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pub fn walk_crate<'a, V: Visitor<'a>>(visitor: &mut V, krate: &'a Crate) {
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walk_list!(visitor, visit_item, &krate.items);
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walk_list!(visitor, visit_attribute, &krate.attrs);
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}
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pub fn walk_local<'a, V: Visitor<'a>>(visitor: &mut V, local: &'a Local) {
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for attr in local.attrs.iter() {
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visitor.visit_attribute(attr);
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}
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visitor.visit_pat(&local.pat);
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walk_list!(visitor, visit_ty, &local.ty);
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if let Some((init, els)) = local.kind.init_else_opt() {
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visitor.visit_expr(init);
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walk_list!(visitor, visit_block, els);
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}
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}
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pub fn walk_label<'a, V: Visitor<'a>>(visitor: &mut V, label: &'a Label) {
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visitor.visit_ident(label.ident);
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}
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pub fn walk_lifetime<'a, V: Visitor<'a>>(visitor: &mut V, lifetime: &'a Lifetime) {
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visitor.visit_ident(lifetime.ident);
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}
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pub fn walk_poly_trait_ref<'a, V>(visitor: &mut V, trait_ref: &'a PolyTraitRef)
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where
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V: Visitor<'a>,
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{
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walk_list!(visitor, visit_generic_param, &trait_ref.bound_generic_params);
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visitor.visit_trait_ref(&trait_ref.trait_ref);
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}
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pub fn walk_trait_ref<'a, V: Visitor<'a>>(visitor: &mut V, trait_ref: &'a TraitRef) {
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visitor.visit_path(&trait_ref.path, trait_ref.ref_id)
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}
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pub fn walk_item<'a, V: Visitor<'a>>(visitor: &mut V, item: &'a Item) {
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visitor.visit_vis(&item.vis);
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visitor.visit_ident(item.ident);
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match &item.kind {
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ItemKind::ExternCrate(_) => {}
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ItemKind::Use(use_tree) => visitor.visit_use_tree(use_tree, item.id, false),
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ItemKind::Static(box StaticItem { ty, mutability: _, expr })
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| ItemKind::Const(box ConstItem { ty, expr, .. }) => {
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visitor.visit_ty(ty);
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walk_list!(visitor, visit_expr, expr);
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}
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ItemKind::Fn(box Fn { defaultness: _, generics, sig, body }) => {
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let kind =
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FnKind::Fn(FnCtxt::Free, item.ident, sig, &item.vis, generics, body.as_deref());
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visitor.visit_fn(kind, item.span, item.id)
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}
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ItemKind::Mod(_unsafety, mod_kind) => match mod_kind {
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ModKind::Loaded(items, _inline, _inner_span) => {
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walk_list!(visitor, visit_item, items)
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}
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ModKind::Unloaded => {}
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},
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ItemKind::ForeignMod(foreign_module) => {
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walk_list!(visitor, visit_foreign_item, &foreign_module.items);
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}
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ItemKind::GlobalAsm(asm) => visitor.visit_inline_asm(asm),
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ItemKind::TyAlias(box TyAlias { generics, bounds, ty, .. }) => {
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visitor.visit_generics(generics);
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walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
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walk_list!(visitor, visit_ty, ty);
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}
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ItemKind::Enum(enum_definition, generics) => {
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visitor.visit_generics(generics);
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visitor.visit_enum_def(enum_definition)
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}
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ItemKind::Impl(box Impl {
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defaultness: _,
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unsafety: _,
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generics,
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constness: _,
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polarity: _,
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of_trait,
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self_ty,
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items,
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}) => {
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visitor.visit_generics(generics);
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walk_list!(visitor, visit_trait_ref, of_trait);
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visitor.visit_ty(self_ty);
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walk_list!(visitor, visit_assoc_item, items, AssocCtxt::Impl);
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}
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ItemKind::Struct(struct_definition, generics)
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| ItemKind::Union(struct_definition, generics) => {
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visitor.visit_generics(generics);
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visitor.visit_variant_data(struct_definition);
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}
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ItemKind::Trait(box Trait { unsafety: _, is_auto: _, generics, bounds, items }) => {
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visitor.visit_generics(generics);
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walk_list!(visitor, visit_param_bound, bounds, BoundKind::SuperTraits);
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walk_list!(visitor, visit_assoc_item, items, AssocCtxt::Trait);
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}
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ItemKind::TraitAlias(generics, bounds) => {
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visitor.visit_generics(generics);
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walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
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}
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ItemKind::MacCall(mac) => visitor.visit_mac_call(mac),
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ItemKind::MacroDef(ts) => visitor.visit_mac_def(ts, item.id),
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}
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walk_list!(visitor, visit_attribute, &item.attrs);
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}
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pub fn walk_enum_def<'a, V: Visitor<'a>>(visitor: &mut V, enum_definition: &'a EnumDef) {
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walk_list!(visitor, visit_variant, &enum_definition.variants);
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}
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pub fn walk_variant<'a, V: Visitor<'a>>(visitor: &mut V, variant: &'a Variant)
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where
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V: Visitor<'a>,
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{
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visitor.visit_ident(variant.ident);
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visitor.visit_vis(&variant.vis);
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visitor.visit_variant_data(&variant.data);
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walk_list!(visitor, visit_variant_discr, &variant.disr_expr);
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walk_list!(visitor, visit_attribute, &variant.attrs);
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|
}
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|
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|
pub fn walk_expr_field<'a, V: Visitor<'a>>(visitor: &mut V, f: &'a ExprField) {
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visitor.visit_expr(&f.expr);
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visitor.visit_ident(f.ident);
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walk_list!(visitor, visit_attribute, f.attrs.iter());
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}
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|
pub fn walk_pat_field<'a, V: Visitor<'a>>(visitor: &mut V, fp: &'a PatField) {
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|
visitor.visit_ident(fp.ident);
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visitor.visit_pat(&fp.pat);
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|
walk_list!(visitor, visit_attribute, fp.attrs.iter());
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|
}
|
|
|
|
pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) {
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|
match &typ.kind {
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|
TyKind::Slice(ty) | TyKind::Paren(ty) => visitor.visit_ty(ty),
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TyKind::Ptr(mutable_type) => visitor.visit_ty(&mutable_type.ty),
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|
TyKind::Ref(opt_lifetime, mutable_type) => {
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|
walk_list!(visitor, visit_lifetime, opt_lifetime, LifetimeCtxt::Ref);
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|
visitor.visit_ty(&mutable_type.ty)
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|
}
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|
TyKind::Tup(tuple_element_types) => {
|
|
walk_list!(visitor, visit_ty, tuple_element_types);
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|
}
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|
TyKind::BareFn(function_declaration) => {
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|
walk_list!(visitor, visit_generic_param, &function_declaration.generic_params);
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|
walk_fn_decl(visitor, &function_declaration.decl);
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|
}
|
|
TyKind::Path(maybe_qself, path) => {
|
|
if let Some(qself) = maybe_qself {
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|
visitor.visit_ty(&qself.ty);
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|
}
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|
visitor.visit_path(path, typ.id);
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}
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|
TyKind::Array(ty, length) => {
|
|
visitor.visit_ty(ty);
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|
visitor.visit_anon_const(length)
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|
}
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|
TyKind::TraitObject(bounds, ..) => {
|
|
walk_list!(visitor, visit_param_bound, bounds, BoundKind::TraitObject);
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|
}
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|
TyKind::ImplTrait(_, bounds) => {
|
|
walk_list!(visitor, visit_param_bound, bounds, BoundKind::Impl);
|
|
}
|
|
TyKind::Typeof(expression) => visitor.visit_anon_const(expression),
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|
TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => {}
|
|
TyKind::MacCall(mac) => visitor.visit_mac_call(mac),
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|
TyKind::Never | TyKind::CVarArgs => {}
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|
}
|
|
}
|
|
|
|
pub fn walk_path<'a, V: Visitor<'a>>(visitor: &mut V, path: &'a Path) {
|
|
for segment in &path.segments {
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|
visitor.visit_path_segment(segment);
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|
}
|
|
}
|
|
|
|
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 { ty, expr, .. }) => {
|
|
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::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)
|
|
}
|
|
}
|
|
}
|