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rust/compiler/rustc_ast/src/visit.rs
Stuart Cook 27c6e40755
Rollup merge of #139112 - m-ou-se:super-let, r=lcnr 
Implement `super let`

Tracking issue: https://github.com/rust-lang/rust/issues/139076

This implements `super let` as proposed in #139080, based on the following two equivalence rules.

1. For all expressions `$expr` in any context, these are equivalent:
  - `& $expr`
  - `{ super let a = & $expr; a }`

2. And, additionally, these are equivalent in any context when `$expr` is a temporary (aka rvalue):
  - `& $expr`
  - `{ super let a = $expr; & a }`

So far, this experiment has a few interesting results:

## Interesting result 1

In this snippet:

```rust
super let a = f(&temp());
```

I originally expected temporary `temp()` would be dropped at the end of the statement (`;`), just like in a regular `let`, because `temp()` is not subject to temporary lifetime extension.

However, it turns out that that would break the fundamental equivalence rules.

For example, in

```rust
g(&f(&temp()));
```

the temporary `temp()` will be dropped at the `;`.

The first equivalence rule tells us this must be equivalent:

```rust
g({ super let a = &f(&temp()); a });
```

But that means that `temp()` must live until the last `;` (after `g()`), not just the first `;` (after `f()`).

While this was somewhat surprising to me at first, it does match the exact behavior we need for `pin!()`: The following _should work_. (See also https://github.com/rust-lang/rust/issues/138718)

```rust
g(pin!(f(&mut temp())));
```

Here, `temp()` lives until the end of the statement. This makes sense from the perspective of the user, as no other `;` or `{}` are visible. Whether `pin!()` uses a `{}` block internally or not should be irrelevant.

This means that _nothing_ in a `super let` statement will be dropped at the end of that super let statement. It does not even need its own scope.

This raises questions that are useful for later on:

- Will this make temporaries live _too long_ in cases where `super let` is used not in a hidden block in a macro, but as a visible statement in code like the following?

    ```rust
    let writer = {
        super let file = File::create(&format!("/home/{user}/test"));
        Writer::new(&file)
    };
    ```

- Is a `let` statement in a block still the right syntax for this? Considering it has _no_ scope of its own, maybe neither a block nor a statement should be involved

This leads me to think that instead of `{ super let $pat = $init; $expr }`, we might want to consider something like `let $pat = $init in $expr` or `$expr where $pat = $init`. Although there are also issues with these, as it isn't obvious anymore if `$init` should be subject to temporary lifetime extension. (Do we want both `let _ = _ in ..` and `super let _ = _ in ..`?)

## Interesting result 2

What about `super let x;` without initializer?

```rust
let a = {
    super let x;
    x = temp();
    &x
};
```

This works fine with the implementation in this PR: `x` is extended to live as long as `a`.

While it matches my expectations, a somewhat interesting thing to realize is that these are _not_ equivalent:

- `super let x = $expr;`
- `super let x; x = $expr;`

In the first case, all temporaries in $expr will live at least as long as (the result of) the surrounding block.
In the second case, temporaries will be dropped at the end of the assignment statement. (Because the assignment statement itself "is not `super`".)

This difference in behavior might be confusing, but it _might_ be useful.
One might want to extend the lifetime of a variable without extending all the temporaries in the initializer expression.

On the other hand, that can also be expressed as:

- `let x = $expr; super let x = x;` (w/o temporary lifetime extension), or
- `super let x = { $expr };` (w/ temporary lifetime extension)

So, this raises these questions:

- Do we want to accept `super let x;` without initializer at all?

- Does it make sense for statements other than let statements to be "super"? An expression statement also drops temporaries at its `;`, so now that we discovered that `super let` basically disables that `;` (see interesting result 1), is there a use to having other statements without their own scope? (I don't think that's ever useful?)

## Interesting result 3

This works now:

```rust
super let Some(x) = a.get(i) else { return };
```

I didn't put in any special cases for `super let else`. This is just the behavior that 'naturally' falls out when implementing `super let` without thinking of the `let else` case.

- Should `super let else` work?

## Interesting result 4

This 'works':

```rust
fn main() {
    super let a = 123;
}
```

I didn't put in any special cases for `super let` at function scope. I had expected the code to cause an ICE or other weird failure when used at function body scope, because there's no way to let the variable live as long as the result of the function.

This raises the question:

- Does this mean that this behavior is the natural/expected behavior when `super let` is used at function scope? Or is this just a quirk and should we explicitly disallow `super let` in a function body? (Probably the latter.)

---

The questions above do not need an answer to land this PR. These questions should be considered when redesigning/rfc'ing/stabilizing the feature.
2025-04-07 22:29:18 +10:00

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//! 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.
pub use rustc_ast_ir::visit::VisitorResult;
pub use rustc_ast_ir::{try_visit, visit_opt, walk_list, walk_visitable_list};
use rustc_span::{Ident, Span};
use thin_vec::ThinVec;
use crate::ast::*;
use crate::ptr::P;
#[derive(Copy, Clone, Debug, PartialEq)]
pub enum AssocCtxt {
Trait,
Impl { of_trait: bool },
}
#[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,
}
impl BoundKind {
pub fn descr(self) -> &'static str {
match self {
BoundKind::Bound => "bounds",
BoundKind::Impl => "`impl Trait`",
BoundKind::TraitObject => "`dyn` trait object bounds",
BoundKind::SuperTraits => "supertrait bounds",
}
}
}
#[derive(Copy, Clone, Debug)]
pub enum FnKind<'a> {
/// E.g., `fn foo()`, `fn foo(&self)`, or `extern "Abi" fn foo()`.
Fn(FnCtxt, &'a Visibility, &'a Fn),
/// E.g., `|x, y| body`.
Closure(&'a ClosureBinder, &'a Option<CoroutineKind>, &'a FnDecl, &'a Expr),
}
impl<'a> FnKind<'a> {
pub fn header(&self) -> Option<&'a FnHeader> {
match *self {
FnKind::Fn(_, _, Fn { sig, .. }) => Some(&sig.header),
FnKind::Closure(..) => None,
}
}
pub fn ident(&self) -> Option<&Ident> {
match self {
FnKind::Fn(_, _, Fn { ident, .. }) => Some(ident),
_ => None,
}
}
pub fn decl(&self) -> &'a FnDecl {
match self {
FnKind::Fn(_, _, 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,
}
pub trait WalkItemKind {
type Ctxt;
fn walk<'a, V: Visitor<'a>>(
&'a self,
span: Span,
id: NodeId,
visibility: &'a Visibility,
ctxt: Self::Ctxt,
visitor: &mut V,
) -> V::Result;
}
/// 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 {
/// The result type of the `visit_*` methods. Can be either `()`,
/// or `ControlFlow<T>`.
type Result: VisitorResult = ();
fn visit_ident(&mut self, _ident: &'ast Ident) -> Self::Result {
Self::Result::output()
}
fn visit_foreign_item(&mut self, i: &'ast ForeignItem) -> Self::Result {
walk_item(self, i)
}
fn visit_item(&mut self, i: &'ast Item) -> Self::Result {
walk_item(self, i)
}
fn visit_local(&mut self, l: &'ast Local) -> Self::Result {
walk_local(self, l)
}
fn visit_block(&mut self, b: &'ast Block) -> Self::Result {
walk_block(self, b)
}
fn visit_stmt(&mut self, s: &'ast Stmt) -> Self::Result {
walk_stmt(self, s)
}
fn visit_param(&mut self, param: &'ast Param) -> Self::Result {
walk_param(self, param)
}
fn visit_arm(&mut self, a: &'ast Arm) -> Self::Result {
walk_arm(self, a)
}
fn visit_pat(&mut self, p: &'ast Pat) -> Self::Result {
walk_pat(self, p)
}
fn visit_anon_const(&mut self, c: &'ast AnonConst) -> Self::Result {
walk_anon_const(self, c)
}
fn visit_expr(&mut self, ex: &'ast Expr) -> Self::Result {
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::Result {
self.visit_expr(ex)
}
fn visit_ty(&mut self, t: &'ast Ty) -> Self::Result {
walk_ty(self, t)
}
fn visit_ty_pat(&mut self, t: &'ast TyPat) -> Self::Result {
walk_ty_pat(self, t)
}
fn visit_generic_param(&mut self, param: &'ast GenericParam) -> Self::Result {
walk_generic_param(self, param)
}
fn visit_generics(&mut self, g: &'ast Generics) -> Self::Result {
walk_generics(self, g)
}
fn visit_closure_binder(&mut self, b: &'ast ClosureBinder) -> Self::Result {
walk_closure_binder(self, b)
}
fn visit_contract(&mut self, c: &'ast FnContract) -> Self::Result {
walk_contract(self, c)
}
fn visit_where_predicate(&mut self, p: &'ast WherePredicate) -> Self::Result {
walk_where_predicate(self, p)
}
fn visit_where_predicate_kind(&mut self, k: &'ast WherePredicateKind) -> Self::Result {
walk_where_predicate_kind(self, k)
}
fn visit_fn(&mut self, fk: FnKind<'ast>, _: Span, _: NodeId) -> Self::Result {
walk_fn(self, fk)
}
fn visit_assoc_item(&mut self, i: &'ast AssocItem, ctxt: AssocCtxt) -> Self::Result {
walk_assoc_item(self, i, ctxt)
}
fn visit_trait_ref(&mut self, t: &'ast TraitRef) -> Self::Result {
walk_trait_ref(self, t)
}
fn visit_param_bound(&mut self, bounds: &'ast GenericBound, _ctxt: BoundKind) -> Self::Result {
walk_param_bound(self, bounds)
}
fn visit_precise_capturing_arg(&mut self, arg: &'ast PreciseCapturingArg) -> Self::Result {
walk_precise_capturing_arg(self, arg)
}
fn visit_poly_trait_ref(&mut self, t: &'ast PolyTraitRef) -> Self::Result {
walk_poly_trait_ref(self, t)
}
fn visit_variant_data(&mut self, s: &'ast VariantData) -> Self::Result {
walk_struct_def(self, s)
}
fn visit_field_def(&mut self, s: &'ast FieldDef) -> Self::Result {
walk_field_def(self, s)
}
fn visit_enum_def(&mut self, enum_definition: &'ast EnumDef) -> Self::Result {
walk_enum_def(self, enum_definition)
}
fn visit_variant(&mut self, v: &'ast Variant) -> Self::Result {
walk_variant(self, v)
}
fn visit_variant_discr(&mut self, discr: &'ast AnonConst) -> Self::Result {
self.visit_anon_const(discr)
}
fn visit_label(&mut self, label: &'ast Label) -> Self::Result {
walk_label(self, label)
}
fn visit_lifetime(&mut self, lifetime: &'ast Lifetime, _: LifetimeCtxt) -> Self::Result {
walk_lifetime(self, lifetime)
}
fn visit_mac_call(&mut self, mac: &'ast MacCall) -> Self::Result {
walk_mac(self, mac)
}
fn visit_mac_def(&mut self, _mac: &'ast MacroDef, _id: NodeId) -> Self::Result {
Self::Result::output()
}
fn visit_path(&mut self, path: &'ast Path, _id: NodeId) -> Self::Result {
walk_path(self, path)
}
fn visit_use_tree(
&mut self,
use_tree: &'ast UseTree,
id: NodeId,
_nested: bool,
) -> Self::Result {
walk_use_tree(self, use_tree, id)
}
fn visit_path_segment(&mut self, path_segment: &'ast PathSegment) -> Self::Result {
walk_path_segment(self, path_segment)
}
fn visit_generic_args(&mut self, generic_args: &'ast GenericArgs) -> Self::Result {
walk_generic_args(self, generic_args)
}
fn visit_generic_arg(&mut self, generic_arg: &'ast GenericArg) -> Self::Result {
walk_generic_arg(self, generic_arg)
}
fn visit_assoc_item_constraint(
&mut self,
constraint: &'ast AssocItemConstraint,
) -> Self::Result {
walk_assoc_item_constraint(self, constraint)
}
fn visit_attribute(&mut self, attr: &'ast Attribute) -> Self::Result {
walk_attribute(self, attr)
}
fn visit_vis(&mut self, vis: &'ast Visibility) -> Self::Result {
walk_vis(self, vis)
}
fn visit_fn_ret_ty(&mut self, ret_ty: &'ast FnRetTy) -> Self::Result {
walk_fn_ret_ty(self, ret_ty)
}
fn visit_fn_header(&mut self, header: &'ast FnHeader) -> Self::Result {
walk_fn_header(self, header)
}
fn visit_expr_field(&mut self, f: &'ast ExprField) -> Self::Result {
walk_expr_field(self, f)
}
fn visit_pat_field(&mut self, fp: &'ast PatField) -> Self::Result {
walk_pat_field(self, fp)
}
fn visit_crate(&mut self, krate: &'ast Crate) -> Self::Result {
walk_crate(self, krate)
}
fn visit_inline_asm(&mut self, asm: &'ast InlineAsm) -> Self::Result {
walk_inline_asm(self, asm)
}
fn visit_format_args(&mut self, fmt: &'ast FormatArgs) -> Self::Result {
walk_format_args(self, fmt)
}
fn visit_inline_asm_sym(&mut self, sym: &'ast InlineAsmSym) -> Self::Result {
walk_inline_asm_sym(self, sym)
}
fn visit_capture_by(&mut self, _capture_by: &'ast CaptureBy) -> Self::Result {
Self::Result::output()
}
fn visit_coroutine_kind(&mut self, _coroutine_kind: &'ast CoroutineKind) -> Self::Result {
Self::Result::output()
}
fn visit_fn_decl(&mut self, fn_decl: &'ast FnDecl) -> Self::Result {
walk_fn_decl(self, fn_decl)
}
fn visit_qself(&mut self, qs: &'ast Option<P<QSelf>>) -> Self::Result {
walk_qself(self, qs)
}
}
pub fn walk_crate<'a, V: Visitor<'a>>(visitor: &mut V, krate: &'a Crate) -> V::Result {
let Crate { attrs, items, spans: _, id: _, is_placeholder: _ } = krate;
walk_list!(visitor, visit_attribute, attrs);
walk_list!(visitor, visit_item, items);
V::Result::output()
}
pub fn walk_local<'a, V: Visitor<'a>>(visitor: &mut V, local: &'a Local) -> V::Result {
let Local { id: _, super_: _, pat, ty, kind, span: _, colon_sp: _, attrs, tokens: _ } = local;
walk_list!(visitor, visit_attribute, attrs);
try_visit!(visitor.visit_pat(pat));
visit_opt!(visitor, visit_ty, ty);
if let Some((init, els)) = kind.init_else_opt() {
try_visit!(visitor.visit_expr(init));
visit_opt!(visitor, visit_block, els);
}
V::Result::output()
}
pub fn walk_label<'a, V: Visitor<'a>>(visitor: &mut V, Label { ident }: &'a Label) -> V::Result {
visitor.visit_ident(ident)
}
pub fn walk_lifetime<'a, V: Visitor<'a>>(visitor: &mut V, lifetime: &'a Lifetime) -> V::Result {
let Lifetime { id: _, ident } = lifetime;
visitor.visit_ident(ident)
}
pub fn walk_poly_trait_ref<'a, V>(visitor: &mut V, trait_ref: &'a PolyTraitRef) -> V::Result
where
V: Visitor<'a>,
{
let PolyTraitRef { bound_generic_params, modifiers: _, trait_ref, span: _ } = trait_ref;
walk_list!(visitor, visit_generic_param, bound_generic_params);
visitor.visit_trait_ref(trait_ref)
}
pub fn walk_trait_ref<'a, V: Visitor<'a>>(visitor: &mut V, trait_ref: &'a TraitRef) -> V::Result {
let TraitRef { path, ref_id } = trait_ref;
visitor.visit_path(path, *ref_id)
}
impl WalkItemKind for ItemKind {
type Ctxt = ();
fn walk<'a, V: Visitor<'a>>(
&'a self,
span: Span,
id: NodeId,
vis: &'a Visibility,
_ctxt: Self::Ctxt,
visitor: &mut V,
) -> V::Result {
match self {
ItemKind::ExternCrate(_rename, ident) => try_visit!(visitor.visit_ident(ident)),
ItemKind::Use(use_tree) => try_visit!(visitor.visit_use_tree(use_tree, id, false)),
ItemKind::Static(box StaticItem {
ident,
ty,
safety: _,
mutability: _,
expr,
define_opaque,
}) => {
try_visit!(visitor.visit_ident(ident));
try_visit!(visitor.visit_ty(ty));
visit_opt!(visitor, visit_expr, expr);
try_visit!(walk_define_opaques(visitor, define_opaque));
}
ItemKind::Const(box ConstItem {
defaultness: _,
ident,
generics,
ty,
expr,
define_opaque,
}) => {
try_visit!(visitor.visit_ident(ident));
try_visit!(visitor.visit_generics(generics));
try_visit!(visitor.visit_ty(ty));
visit_opt!(visitor, visit_expr, expr);
try_visit!(walk_define_opaques(visitor, define_opaque));
}
ItemKind::Fn(func) => {
let kind = FnKind::Fn(FnCtxt::Free, vis, &*func);
try_visit!(visitor.visit_fn(kind, span, id));
}
ItemKind::Mod(_unsafety, ident, mod_kind) => {
try_visit!(visitor.visit_ident(ident));
match mod_kind {
ModKind::Loaded(items, _inline, _inner_span, _) => {
walk_list!(visitor, visit_item, items);
}
ModKind::Unloaded => {}
}
}
ItemKind::ForeignMod(ForeignMod { extern_span: _, safety: _, abi: _, items }) => {
walk_list!(visitor, visit_foreign_item, items);
}
ItemKind::GlobalAsm(asm) => try_visit!(visitor.visit_inline_asm(asm)),
ItemKind::TyAlias(box TyAlias {
generics,
ident,
bounds,
ty,
defaultness: _,
where_clauses: _,
}) => {
try_visit!(visitor.visit_ident(ident));
try_visit!(visitor.visit_generics(generics));
walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
visit_opt!(visitor, visit_ty, ty);
}
ItemKind::Enum(ident, enum_definition, generics) => {
try_visit!(visitor.visit_ident(ident));
try_visit!(visitor.visit_generics(generics));
try_visit!(visitor.visit_enum_def(enum_definition));
}
ItemKind::Impl(box Impl {
defaultness: _,
safety: _,
generics,
constness: _,
polarity: _,
of_trait,
self_ty,
items,
}) => {
try_visit!(visitor.visit_generics(generics));
visit_opt!(visitor, visit_trait_ref, of_trait);
try_visit!(visitor.visit_ty(self_ty));
walk_list!(
visitor,
visit_assoc_item,
items,
AssocCtxt::Impl { of_trait: of_trait.is_some() }
);
}
ItemKind::Struct(ident, struct_definition, generics)
| ItemKind::Union(ident, struct_definition, generics) => {
try_visit!(visitor.visit_ident(ident));
try_visit!(visitor.visit_generics(generics));
try_visit!(visitor.visit_variant_data(struct_definition));
}
ItemKind::Trait(box Trait {
safety: _,
is_auto: _,
ident,
generics,
bounds,
items,
}) => {
try_visit!(visitor.visit_ident(ident));
try_visit!(visitor.visit_generics(generics));
walk_list!(visitor, visit_param_bound, bounds, BoundKind::SuperTraits);
walk_list!(visitor, visit_assoc_item, items, AssocCtxt::Trait);
}
ItemKind::TraitAlias(ident, generics, bounds) => {
try_visit!(visitor.visit_ident(ident));
try_visit!(visitor.visit_generics(generics));
walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
}
ItemKind::MacCall(mac) => try_visit!(visitor.visit_mac_call(mac)),
ItemKind::MacroDef(ident, ts) => {
try_visit!(visitor.visit_ident(ident));
try_visit!(visitor.visit_mac_def(ts, id))
}
ItemKind::Delegation(box Delegation {
id,
qself,
path,
ident,
rename,
body,
from_glob: _,
}) => {
try_visit!(visitor.visit_qself(qself));
try_visit!(visitor.visit_path(path, *id));
try_visit!(visitor.visit_ident(ident));
visit_opt!(visitor, visit_ident, rename);
visit_opt!(visitor, visit_block, body);
}
ItemKind::DelegationMac(box DelegationMac { qself, prefix, suffixes, body }) => {
try_visit!(visitor.visit_qself(qself));
try_visit!(visitor.visit_path(prefix, id));
if let Some(suffixes) = suffixes {
for (ident, rename) in suffixes {
visitor.visit_ident(ident);
if let Some(rename) = rename {
visitor.visit_ident(rename);
}
}
}
visit_opt!(visitor, visit_block, body);
}
}
V::Result::output()
}
}
pub fn walk_enum_def<'a, V: Visitor<'a>>(
visitor: &mut V,
EnumDef { variants }: &'a EnumDef,
) -> V::Result {
walk_list!(visitor, visit_variant, variants);
V::Result::output()
}
pub fn walk_variant<'a, V: Visitor<'a>>(visitor: &mut V, variant: &'a Variant) -> V::Result
where
V: Visitor<'a>,
{
let Variant { attrs, id: _, span: _, vis, ident, data, disr_expr, is_placeholder: _ } = variant;
walk_list!(visitor, visit_attribute, attrs);
try_visit!(visitor.visit_vis(vis));
try_visit!(visitor.visit_ident(ident));
try_visit!(visitor.visit_variant_data(data));
visit_opt!(visitor, visit_variant_discr, disr_expr);
V::Result::output()
}
pub fn walk_expr_field<'a, V: Visitor<'a>>(visitor: &mut V, f: &'a ExprField) -> V::Result {
let ExprField { attrs, id: _, span: _, ident, expr, is_shorthand: _, is_placeholder: _ } = f;
walk_list!(visitor, visit_attribute, attrs);
try_visit!(visitor.visit_ident(ident));
try_visit!(visitor.visit_expr(expr));
V::Result::output()
}
pub fn walk_pat_field<'a, V: Visitor<'a>>(visitor: &mut V, fp: &'a PatField) -> V::Result {
let PatField { ident, pat, is_shorthand: _, attrs, id: _, span: _, is_placeholder: _ } = fp;
walk_list!(visitor, visit_attribute, attrs);
try_visit!(visitor.visit_ident(ident));
try_visit!(visitor.visit_pat(pat));
V::Result::output()
}
pub fn walk_ty<'a, V: Visitor<'a>>(visitor: &mut V, typ: &'a Ty) -> V::Result {
let Ty { id, kind, span: _, tokens: _ } = typ;
match kind {
TyKind::Slice(ty) | TyKind::Paren(ty) => try_visit!(visitor.visit_ty(ty)),
TyKind::Ptr(MutTy { ty, mutbl: _ }) => try_visit!(visitor.visit_ty(ty)),
TyKind::Ref(opt_lifetime, MutTy { ty, mutbl: _ })
| TyKind::PinnedRef(opt_lifetime, MutTy { ty, mutbl: _ }) => {
visit_opt!(visitor, visit_lifetime, opt_lifetime, LifetimeCtxt::Ref);
try_visit!(visitor.visit_ty(ty));
}
TyKind::Tup(tuple_element_types) => {
walk_list!(visitor, visit_ty, tuple_element_types);
}
TyKind::BareFn(function_declaration) => {
let BareFnTy { safety: _, ext: _, generic_params, decl, decl_span: _ } =
&**function_declaration;
walk_list!(visitor, visit_generic_param, generic_params);
try_visit!(visitor.visit_fn_decl(decl));
}
TyKind::UnsafeBinder(binder) => {
walk_list!(visitor, visit_generic_param, &binder.generic_params);
try_visit!(visitor.visit_ty(&binder.inner_ty));
}
TyKind::Path(maybe_qself, path) => {
try_visit!(visitor.visit_qself(maybe_qself));
try_visit!(visitor.visit_path(path, *id));
}
TyKind::Pat(ty, pat) => {
try_visit!(visitor.visit_ty(ty));
try_visit!(visitor.visit_ty_pat(pat));
}
TyKind::Array(ty, length) => {
try_visit!(visitor.visit_ty(ty));
try_visit!(visitor.visit_anon_const(length));
}
TyKind::TraitObject(bounds, _syntax) => {
walk_list!(visitor, visit_param_bound, bounds, BoundKind::TraitObject);
}
TyKind::ImplTrait(_id, bounds) => {
walk_list!(visitor, visit_param_bound, bounds, BoundKind::Impl);
}
TyKind::Typeof(expression) => try_visit!(visitor.visit_anon_const(expression)),
TyKind::Infer | TyKind::ImplicitSelf | TyKind::Dummy => {}
TyKind::Err(_guar) => {}
TyKind::MacCall(mac) => try_visit!(visitor.visit_mac_call(mac)),
TyKind::Never | TyKind::CVarArgs => {}
}
V::Result::output()
}
pub fn walk_ty_pat<'a, V: Visitor<'a>>(visitor: &mut V, tp: &'a TyPat) -> V::Result {
let TyPat { id: _, kind, span: _, tokens: _ } = tp;
match kind {
TyPatKind::Range(start, end, _include_end) => {
visit_opt!(visitor, visit_anon_const, start);
visit_opt!(visitor, visit_anon_const, end);
}
TyPatKind::Err(_) => {}
}
V::Result::output()
}
fn walk_qself<'a, V: Visitor<'a>>(visitor: &mut V, qself: &'a Option<P<QSelf>>) -> V::Result {
if let Some(qself) = qself {
let QSelf { ty, path_span: _, position: _ } = &**qself;
try_visit!(visitor.visit_ty(ty));
}
V::Result::output()
}
pub fn walk_path<'a, V: Visitor<'a>>(visitor: &mut V, path: &'a Path) -> V::Result {
let Path { span: _, segments, tokens: _ } = path;
walk_list!(visitor, visit_path_segment, segments);
V::Result::output()
}
pub fn walk_use_tree<'a, V: Visitor<'a>>(
visitor: &mut V,
use_tree: &'a UseTree,
id: NodeId,
) -> V::Result {
let UseTree { prefix, kind, span: _ } = use_tree;
try_visit!(visitor.visit_path(prefix, id));
match kind {
UseTreeKind::Simple(rename) => {
// The extra IDs are handled during AST lowering.
visit_opt!(visitor, visit_ident, rename);
}
UseTreeKind::Glob => {}
UseTreeKind::Nested { items, span: _ } => {
for &(ref nested_tree, nested_id) in items {
try_visit!(visitor.visit_use_tree(nested_tree, nested_id, true));
}
}
}
V::Result::output()
}
pub fn walk_path_segment<'a, V: Visitor<'a>>(
visitor: &mut V,
segment: &'a PathSegment,
) -> V::Result {
let PathSegment { ident, id: _, args } = segment;
try_visit!(visitor.visit_ident(ident));
visit_opt!(visitor, visit_generic_args, args);
V::Result::output()
}
pub fn walk_generic_args<'a, V>(visitor: &mut V, generic_args: &'a GenericArgs) -> V::Result
where
V: Visitor<'a>,
{
match generic_args {
GenericArgs::AngleBracketed(AngleBracketedArgs { span: _, args }) => {
for arg in args {
match arg {
AngleBracketedArg::Arg(a) => try_visit!(visitor.visit_generic_arg(a)),
AngleBracketedArg::Constraint(c) => {
try_visit!(visitor.visit_assoc_item_constraint(c))
}
}
}
}
GenericArgs::Parenthesized(data) => {
let ParenthesizedArgs { span: _, inputs, inputs_span: _, output } = data;
walk_list!(visitor, visit_ty, inputs);
try_visit!(visitor.visit_fn_ret_ty(output));
}
GenericArgs::ParenthesizedElided(_span) => {}
}
V::Result::output()
}
pub fn walk_generic_arg<'a, V>(visitor: &mut V, generic_arg: &'a GenericArg) -> V::Result
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_item_constraint<'a, V: Visitor<'a>>(
visitor: &mut V,
constraint: &'a AssocItemConstraint,
) -> V::Result {
let AssocItemConstraint { id: _, ident, gen_args, kind, span: _ } = constraint;
try_visit!(visitor.visit_ident(ident));
visit_opt!(visitor, visit_generic_args, gen_args);
match kind {
AssocItemConstraintKind::Equality { term } => match term {
Term::Ty(ty) => try_visit!(visitor.visit_ty(ty)),
Term::Const(c) => try_visit!(visitor.visit_anon_const(c)),
},
AssocItemConstraintKind::Bound { bounds } => {
walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
}
}
V::Result::output()
}
pub fn walk_pat<'a, V: Visitor<'a>>(visitor: &mut V, pattern: &'a Pat) -> V::Result {
let Pat { id, kind, span: _, tokens: _ } = pattern;
match kind {
PatKind::TupleStruct(opt_qself, path, elems) => {
try_visit!(visitor.visit_qself(opt_qself));
try_visit!(visitor.visit_path(path, *id));
walk_list!(visitor, visit_pat, elems);
}
PatKind::Path(opt_qself, path) => {
try_visit!(visitor.visit_qself(opt_qself));
try_visit!(visitor.visit_path(path, *id))
}
PatKind::Struct(opt_qself, path, fields, _rest) => {
try_visit!(visitor.visit_qself(opt_qself));
try_visit!(visitor.visit_path(path, *id));
walk_list!(visitor, visit_pat_field, fields);
}
PatKind::Box(subpattern) | PatKind::Deref(subpattern) | PatKind::Paren(subpattern) => {
try_visit!(visitor.visit_pat(subpattern));
}
PatKind::Ref(subpattern, _ /*mutbl*/) => {
try_visit!(visitor.visit_pat(subpattern));
}
PatKind::Ident(_bmode, ident, optional_subpattern) => {
try_visit!(visitor.visit_ident(ident));
visit_opt!(visitor, visit_pat, optional_subpattern);
}
PatKind::Expr(expression) => try_visit!(visitor.visit_expr(expression)),
PatKind::Range(lower_bound, upper_bound, _end) => {
visit_opt!(visitor, visit_expr, lower_bound);
visit_opt!(visitor, visit_expr, upper_bound);
}
PatKind::Guard(subpattern, guard_condition) => {
try_visit!(visitor.visit_pat(subpattern));
try_visit!(visitor.visit_expr(guard_condition));
}
PatKind::Missing | PatKind::Wild | PatKind::Rest | PatKind::Never => {}
PatKind::Err(_guar) => {}
PatKind::Tuple(elems) | PatKind::Slice(elems) | PatKind::Or(elems) => {
walk_list!(visitor, visit_pat, elems);
}
PatKind::MacCall(mac) => try_visit!(visitor.visit_mac_call(mac)),
}
V::Result::output()
}
impl WalkItemKind for ForeignItemKind {
type Ctxt = ();
fn walk<'a, V: Visitor<'a>>(
&'a self,
span: Span,
id: NodeId,
vis: &'a Visibility,
_ctxt: Self::Ctxt,
visitor: &mut V,
) -> V::Result {
match self {
ForeignItemKind::Static(box StaticItem {
ident,
ty,
mutability: _,
expr,
safety: _,
define_opaque,
}) => {
try_visit!(visitor.visit_ident(ident));
try_visit!(visitor.visit_ty(ty));
visit_opt!(visitor, visit_expr, expr);
try_visit!(walk_define_opaques(visitor, define_opaque));
}
ForeignItemKind::Fn(func) => {
let kind = FnKind::Fn(FnCtxt::Foreign, vis, &*func);
try_visit!(visitor.visit_fn(kind, span, id));
}
ForeignItemKind::TyAlias(box TyAlias {
generics,
ident,
bounds,
ty,
defaultness: _,
where_clauses: _,
}) => {
try_visit!(visitor.visit_ident(ident));
try_visit!(visitor.visit_generics(generics));
walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
visit_opt!(visitor, visit_ty, ty);
}
ForeignItemKind::MacCall(mac) => {
try_visit!(visitor.visit_mac_call(mac));
}
}
V::Result::output()
}
}
pub fn walk_param_bound<'a, V: Visitor<'a>>(visitor: &mut V, bound: &'a GenericBound) -> V::Result {
match bound {
GenericBound::Trait(trait_ref) => visitor.visit_poly_trait_ref(trait_ref),
GenericBound::Outlives(lifetime) => visitor.visit_lifetime(lifetime, LifetimeCtxt::Bound),
GenericBound::Use(args, _span) => {
walk_list!(visitor, visit_precise_capturing_arg, args);
V::Result::output()
}
}
}
pub fn walk_precise_capturing_arg<'a, V: Visitor<'a>>(
visitor: &mut V,
arg: &'a PreciseCapturingArg,
) -> V::Result {
match arg {
PreciseCapturingArg::Lifetime(lt) => visitor.visit_lifetime(lt, LifetimeCtxt::GenericArg),
PreciseCapturingArg::Arg(path, id) => visitor.visit_path(path, *id),
}
}
pub fn walk_generic_param<'a, V: Visitor<'a>>(
visitor: &mut V,
param: &'a GenericParam,
) -> V::Result {
let GenericParam { id: _, ident, attrs, bounds, is_placeholder: _, kind, colon_span: _ } =
param;
walk_list!(visitor, visit_attribute, attrs);
try_visit!(visitor.visit_ident(ident));
walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
match kind {
GenericParamKind::Lifetime => (),
GenericParamKind::Type { default } => visit_opt!(visitor, visit_ty, default),
GenericParamKind::Const { ty, default, kw_span: _ } => {
try_visit!(visitor.visit_ty(ty));
visit_opt!(visitor, visit_anon_const, default);
}
}
V::Result::output()
}
pub fn walk_generics<'a, V: Visitor<'a>>(visitor: &mut V, generics: &'a Generics) -> V::Result {
let Generics { params, where_clause, span: _ } = generics;
let WhereClause { has_where_token: _, predicates, span: _ } = where_clause;
walk_list!(visitor, visit_generic_param, params);
walk_list!(visitor, visit_where_predicate, predicates);
V::Result::output()
}
pub fn walk_closure_binder<'a, V: Visitor<'a>>(
visitor: &mut V,
binder: &'a ClosureBinder,
) -> V::Result {
match binder {
ClosureBinder::NotPresent => {}
ClosureBinder::For { generic_params, span: _ } => {
walk_list!(visitor, visit_generic_param, generic_params)
}
}
V::Result::output()
}
pub fn walk_contract<'a, V: Visitor<'a>>(visitor: &mut V, c: &'a FnContract) -> V::Result {
let FnContract { requires, ensures } = c;
if let Some(pred) = requires {
visitor.visit_expr(pred);
}
if let Some(pred) = ensures {
visitor.visit_expr(pred);
}
V::Result::output()
}
pub fn walk_where_predicate<'a, V: Visitor<'a>>(
visitor: &mut V,
predicate: &'a WherePredicate,
) -> V::Result {
let WherePredicate { attrs, kind, id: _, span: _, is_placeholder: _ } = predicate;
walk_list!(visitor, visit_attribute, attrs);
visitor.visit_where_predicate_kind(kind)
}
pub fn walk_where_predicate_kind<'a, V: Visitor<'a>>(
visitor: &mut V,
kind: &'a WherePredicateKind,
) -> V::Result {
match kind {
WherePredicateKind::BoundPredicate(WhereBoundPredicate {
bounded_ty,
bounds,
bound_generic_params,
}) => {
walk_list!(visitor, visit_generic_param, bound_generic_params);
try_visit!(visitor.visit_ty(bounded_ty));
walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
}
WherePredicateKind::RegionPredicate(WhereRegionPredicate { lifetime, bounds }) => {
try_visit!(visitor.visit_lifetime(lifetime, LifetimeCtxt::Bound));
walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
}
WherePredicateKind::EqPredicate(WhereEqPredicate { lhs_ty, rhs_ty }) => {
try_visit!(visitor.visit_ty(lhs_ty));
try_visit!(visitor.visit_ty(rhs_ty));
}
}
V::Result::output()
}
pub fn walk_fn_ret_ty<'a, V: Visitor<'a>>(visitor: &mut V, ret_ty: &'a FnRetTy) -> V::Result {
match ret_ty {
FnRetTy::Default(_span) => {}
FnRetTy::Ty(output_ty) => try_visit!(visitor.visit_ty(output_ty)),
}
V::Result::output()
}
pub fn walk_fn_header<'a, V: Visitor<'a>>(visitor: &mut V, fn_header: &'a FnHeader) -> V::Result {
let FnHeader { safety: _, coroutine_kind, constness: _, ext: _ } = fn_header;
visit_opt!(visitor, visit_coroutine_kind, coroutine_kind.as_ref());
V::Result::output()
}
pub fn walk_fn_decl<'a, V: Visitor<'a>>(
visitor: &mut V,
FnDecl { inputs, output }: &'a FnDecl,
) -> V::Result {
walk_list!(visitor, visit_param, inputs);
visitor.visit_fn_ret_ty(output)
}
pub fn walk_fn<'a, V: Visitor<'a>>(visitor: &mut V, kind: FnKind<'a>) -> V::Result {
match kind {
FnKind::Fn(
_ctxt,
_vis,
Fn {
defaultness: _,
ident,
sig: FnSig { header, decl, span: _ },
generics,
contract,
body,
define_opaque,
},
) => {
// Visibility is visited as a part of the item.
try_visit!(visitor.visit_ident(ident));
try_visit!(visitor.visit_fn_header(header));
try_visit!(visitor.visit_generics(generics));
try_visit!(visitor.visit_fn_decl(decl));
visit_opt!(visitor, visit_contract, contract);
visit_opt!(visitor, visit_block, body);
try_visit!(walk_define_opaques(visitor, define_opaque));
}
FnKind::Closure(binder, coroutine_kind, decl, body) => {
try_visit!(visitor.visit_closure_binder(binder));
visit_opt!(visitor, visit_coroutine_kind, coroutine_kind.as_ref());
try_visit!(visitor.visit_fn_decl(decl));
try_visit!(visitor.visit_expr(body));
}
}
V::Result::output()
}
impl WalkItemKind for AssocItemKind {
type Ctxt = AssocCtxt;
fn walk<'a, V: Visitor<'a>>(
&'a self,
span: Span,
id: NodeId,
vis: &'a Visibility,
ctxt: Self::Ctxt,
visitor: &mut V,
) -> V::Result {
match self {
AssocItemKind::Const(box ConstItem {
defaultness: _,
ident,
generics,
ty,
expr,
define_opaque,
}) => {
try_visit!(visitor.visit_ident(ident));
try_visit!(visitor.visit_generics(generics));
try_visit!(visitor.visit_ty(ty));
visit_opt!(visitor, visit_expr, expr);
try_visit!(walk_define_opaques(visitor, define_opaque));
}
AssocItemKind::Fn(func) => {
let kind = FnKind::Fn(FnCtxt::Assoc(ctxt), vis, &*func);
try_visit!(visitor.visit_fn(kind, span, id));
}
AssocItemKind::Type(box TyAlias {
generics,
ident,
bounds,
ty,
defaultness: _,
where_clauses: _,
}) => {
try_visit!(visitor.visit_generics(generics));
try_visit!(visitor.visit_ident(ident));
walk_list!(visitor, visit_param_bound, bounds, BoundKind::Bound);
visit_opt!(visitor, visit_ty, ty);
}
AssocItemKind::MacCall(mac) => {
try_visit!(visitor.visit_mac_call(mac));
}
AssocItemKind::Delegation(box Delegation {
id,
qself,
path,
ident,
rename,
body,
from_glob: _,
}) => {
try_visit!(visitor.visit_qself(qself));
try_visit!(visitor.visit_path(path, *id));
try_visit!(visitor.visit_ident(ident));
visit_opt!(visitor, visit_ident, rename);
visit_opt!(visitor, visit_block, body);
}
AssocItemKind::DelegationMac(box DelegationMac { qself, prefix, suffixes, body }) => {
try_visit!(visitor.visit_qself(qself));
try_visit!(visitor.visit_path(prefix, id));
if let Some(suffixes) = suffixes {
for (ident, rename) in suffixes {
visitor.visit_ident(ident);
if let Some(rename) = rename {
visitor.visit_ident(rename);
}
}
}
visit_opt!(visitor, visit_block, body);
}
}
V::Result::output()
}
}
pub fn walk_item<'a, V: Visitor<'a>>(
visitor: &mut V,
item: &'a Item<impl WalkItemKind<Ctxt = ()>>,
) -> V::Result {
walk_item_ctxt(visitor, item, ())
}
pub fn walk_assoc_item<'a, V: Visitor<'a>>(
visitor: &mut V,
item: &'a AssocItem,
ctxt: AssocCtxt,
) -> V::Result {
walk_item_ctxt(visitor, item, ctxt)
}
fn walk_item_ctxt<'a, V: Visitor<'a>, K: WalkItemKind>(
visitor: &mut V,
item: &'a Item<K>,
ctxt: K::Ctxt,
) -> V::Result {
let Item { id, span, vis, attrs, kind, tokens: _ } = item;
walk_list!(visitor, visit_attribute, attrs);
try_visit!(visitor.visit_vis(vis));
try_visit!(kind.walk(*span, *id, vis, ctxt, visitor));
V::Result::output()
}
pub fn walk_struct_def<'a, V: Visitor<'a>>(
visitor: &mut V,
struct_definition: &'a VariantData,
) -> V::Result {
walk_list!(visitor, visit_field_def, struct_definition.fields());
V::Result::output()
}
pub fn walk_field_def<'a, V: Visitor<'a>>(visitor: &mut V, field: &'a FieldDef) -> V::Result {
let FieldDef { attrs, id: _, span: _, vis, ident, ty, is_placeholder: _, safety: _, default } =
field;
walk_list!(visitor, visit_attribute, attrs);
try_visit!(visitor.visit_vis(vis));
visit_opt!(visitor, visit_ident, ident);
try_visit!(visitor.visit_ty(ty));
visit_opt!(visitor, visit_anon_const, &*default);
V::Result::output()
}
pub fn walk_block<'a, V: Visitor<'a>>(visitor: &mut V, block: &'a Block) -> V::Result {
let Block { stmts, id: _, rules: _, span: _, tokens: _ } = block;
walk_list!(visitor, visit_stmt, stmts);
V::Result::output()
}
pub fn walk_stmt<'a, V: Visitor<'a>>(visitor: &mut V, statement: &'a Stmt) -> V::Result {
let Stmt { id: _, kind, span: _ } = statement;
match kind {
StmtKind::Let(local) => try_visit!(visitor.visit_local(local)),
StmtKind::Item(item) => try_visit!(visitor.visit_item(item)),
StmtKind::Expr(expr) | StmtKind::Semi(expr) => try_visit!(visitor.visit_expr(expr)),
StmtKind::Empty => {}
StmtKind::MacCall(mac) => {
let MacCallStmt { mac, attrs, style: _, tokens: _ } = &**mac;
walk_list!(visitor, visit_attribute, attrs);
try_visit!(visitor.visit_mac_call(mac));
}
}
V::Result::output()
}
pub fn walk_mac<'a, V: Visitor<'a>>(visitor: &mut V, mac: &'a MacCall) -> V::Result {
let MacCall { path, args: _ } = mac;
visitor.visit_path(path, DUMMY_NODE_ID)
}
pub fn walk_anon_const<'a, V: Visitor<'a>>(visitor: &mut V, constant: &'a AnonConst) -> V::Result {
let AnonConst { id: _, value } = constant;
visitor.visit_expr(value)
}
pub fn walk_inline_asm<'a, V: Visitor<'a>>(visitor: &mut V, asm: &'a InlineAsm) -> V::Result {
let InlineAsm {
asm_macro: _,
template: _,
template_strs: _,
operands,
clobber_abis: _,
options: _,
line_spans: _,
} = asm;
for (op, _span) in operands {
match op {
InlineAsmOperand::In { expr, reg: _ }
| InlineAsmOperand::Out { expr: Some(expr), reg: _, late: _ }
| InlineAsmOperand::InOut { expr, reg: _, late: _ } => {
try_visit!(visitor.visit_expr(expr))
}
InlineAsmOperand::Out { expr: None, reg: _, late: _ } => {}
InlineAsmOperand::SplitInOut { in_expr, out_expr, reg: _, late: _ } => {
try_visit!(visitor.visit_expr(in_expr));
visit_opt!(visitor, visit_expr, out_expr);
}
InlineAsmOperand::Const { anon_const } => {
try_visit!(visitor.visit_anon_const(anon_const))
}
InlineAsmOperand::Sym { sym } => try_visit!(visitor.visit_inline_asm_sym(sym)),
InlineAsmOperand::Label { block } => try_visit!(visitor.visit_block(block)),
}
}
V::Result::output()
}
pub fn walk_inline_asm_sym<'a, V: Visitor<'a>>(
visitor: &mut V,
InlineAsmSym { id, qself, path }: &'a InlineAsmSym,
) -> V::Result {
try_visit!(visitor.visit_qself(qself));
visitor.visit_path(path, *id)
}
pub fn walk_format_args<'a, V: Visitor<'a>>(visitor: &mut V, fmt: &'a FormatArgs) -> V::Result {
let FormatArgs { span: _, template: _, arguments, uncooked_fmt_str: _ } = fmt;
for FormatArgument { kind, expr } in arguments.all_args() {
match kind {
FormatArgumentKind::Named(ident) | FormatArgumentKind::Captured(ident) => {
try_visit!(visitor.visit_ident(ident))
}
FormatArgumentKind::Normal => {}
}
try_visit!(visitor.visit_expr(expr));
}
V::Result::output()
}
pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) -> V::Result {
let Expr { id, kind, span, attrs, tokens: _ } = expression;
walk_list!(visitor, visit_attribute, attrs);
match kind {
ExprKind::Array(subexpressions) => {
walk_list!(visitor, visit_expr, subexpressions);
}
ExprKind::ConstBlock(anon_const) => try_visit!(visitor.visit_anon_const(anon_const)),
ExprKind::Repeat(element, count) => {
try_visit!(visitor.visit_expr(element));
try_visit!(visitor.visit_anon_const(count));
}
ExprKind::Struct(se) => {
let StructExpr { qself, path, fields, rest } = &**se;
try_visit!(visitor.visit_qself(qself));
try_visit!(visitor.visit_path(path, *id));
walk_list!(visitor, visit_expr_field, fields);
match rest {
StructRest::Base(expr) => try_visit!(visitor.visit_expr(expr)),
StructRest::Rest(_span) => {}
StructRest::None => {}
}
}
ExprKind::Tup(subexpressions) => {
walk_list!(visitor, visit_expr, subexpressions);
}
ExprKind::Call(callee_expression, arguments) => {
try_visit!(visitor.visit_expr(callee_expression));
walk_list!(visitor, visit_expr, arguments);
}
ExprKind::MethodCall(box MethodCall { seg, receiver, args, span: _ }) => {
try_visit!(visitor.visit_expr(receiver));
try_visit!(visitor.visit_path_segment(seg));
walk_list!(visitor, visit_expr, args);
}
ExprKind::Binary(_op, left_expression, right_expression) => {
try_visit!(visitor.visit_expr(left_expression));
try_visit!(visitor.visit_expr(right_expression));
}
ExprKind::AddrOf(_kind, _mutbl, subexpression) => {
try_visit!(visitor.visit_expr(subexpression));
}
ExprKind::Unary(_op, subexpression) => {
try_visit!(visitor.visit_expr(subexpression));
}
ExprKind::Cast(subexpression, typ) | ExprKind::Type(subexpression, typ) => {
try_visit!(visitor.visit_expr(subexpression));
try_visit!(visitor.visit_ty(typ));
}
ExprKind::Let(pat, expr, _span, _recovered) => {
try_visit!(visitor.visit_pat(pat));
try_visit!(visitor.visit_expr(expr));
}
ExprKind::If(head_expression, if_block, optional_else) => {
try_visit!(visitor.visit_expr(head_expression));
try_visit!(visitor.visit_block(if_block));
visit_opt!(visitor, visit_expr, optional_else);
}
ExprKind::While(subexpression, block, opt_label) => {
visit_opt!(visitor, visit_label, opt_label);
try_visit!(visitor.visit_expr(subexpression));
try_visit!(visitor.visit_block(block));
}
ExprKind::ForLoop { pat, iter, body, label, kind: _ } => {
visit_opt!(visitor, visit_label, label);
try_visit!(visitor.visit_pat(pat));
try_visit!(visitor.visit_expr(iter));
try_visit!(visitor.visit_block(body));
}
ExprKind::Loop(block, opt_label, _span) => {
visit_opt!(visitor, visit_label, opt_label);
try_visit!(visitor.visit_block(block));
}
ExprKind::Match(subexpression, arms, _kind) => {
try_visit!(visitor.visit_expr(subexpression));
walk_list!(visitor, visit_arm, arms);
}
ExprKind::Closure(box Closure {
binder,
capture_clause,
coroutine_kind,
constness: _,
movability: _,
fn_decl,
body,
fn_decl_span: _,
fn_arg_span: _,
}) => {
try_visit!(visitor.visit_capture_by(capture_clause));
try_visit!(visitor.visit_fn(
FnKind::Closure(binder, coroutine_kind, fn_decl, body),
*span,
*id
));
}
ExprKind::Block(block, opt_label) => {
visit_opt!(visitor, visit_label, opt_label);
try_visit!(visitor.visit_block(block));
}
ExprKind::Gen(_capt, body, _kind, _decl_span) => try_visit!(visitor.visit_block(body)),
ExprKind::Await(expr, _span) => try_visit!(visitor.visit_expr(expr)),
ExprKind::Use(expr, _span) => try_visit!(visitor.visit_expr(expr)),
ExprKind::Assign(lhs, rhs, _span) => {
try_visit!(visitor.visit_expr(lhs));
try_visit!(visitor.visit_expr(rhs));
}
ExprKind::AssignOp(_op, left_expression, right_expression) => {
try_visit!(visitor.visit_expr(left_expression));
try_visit!(visitor.visit_expr(right_expression));
}
ExprKind::Field(subexpression, ident) => {
try_visit!(visitor.visit_expr(subexpression));
try_visit!(visitor.visit_ident(ident));
}
ExprKind::Index(main_expression, index_expression, _span) => {
try_visit!(visitor.visit_expr(main_expression));
try_visit!(visitor.visit_expr(index_expression));
}
ExprKind::Range(start, end, _limit) => {
visit_opt!(visitor, visit_expr, start);
visit_opt!(visitor, visit_expr, end);
}
ExprKind::Underscore => {}
ExprKind::Path(maybe_qself, path) => {
try_visit!(visitor.visit_qself(maybe_qself));
try_visit!(visitor.visit_path(path, *id));
}
ExprKind::Break(opt_label, opt_expr) => {
visit_opt!(visitor, visit_label, opt_label);
visit_opt!(visitor, visit_expr, opt_expr);
}
ExprKind::Continue(opt_label) => {
visit_opt!(visitor, visit_label, opt_label);
}
ExprKind::Ret(optional_expression) => {
visit_opt!(visitor, visit_expr, optional_expression);
}
ExprKind::Yeet(optional_expression) => {
visit_opt!(visitor, visit_expr, optional_expression);
}
ExprKind::Become(expr) => try_visit!(visitor.visit_expr(expr)),
ExprKind::MacCall(mac) => try_visit!(visitor.visit_mac_call(mac)),
ExprKind::Paren(subexpression) => try_visit!(visitor.visit_expr(subexpression)),
ExprKind::InlineAsm(asm) => try_visit!(visitor.visit_inline_asm(asm)),
ExprKind::FormatArgs(f) => try_visit!(visitor.visit_format_args(f)),
ExprKind::OffsetOf(container, fields) => {
try_visit!(visitor.visit_ty(container));
walk_list!(visitor, visit_ident, fields.iter());
}
ExprKind::Yield(kind) => {
visit_opt!(visitor, visit_expr, kind.expr());
}
ExprKind::Try(subexpression) => try_visit!(visitor.visit_expr(subexpression)),
ExprKind::TryBlock(body) => try_visit!(visitor.visit_block(body)),
ExprKind::Lit(_token) => {}
ExprKind::IncludedBytes(_bytes) => {}
ExprKind::UnsafeBinderCast(_kind, expr, ty) => {
try_visit!(visitor.visit_expr(expr));
visit_opt!(visitor, visit_ty, ty);
}
ExprKind::Err(_guar) => {}
ExprKind::Dummy => {}
}
V::Result::output()
}
pub fn walk_param<'a, V: Visitor<'a>>(visitor: &mut V, param: &'a Param) -> V::Result {
let Param { attrs, ty, pat, id: _, span: _, is_placeholder: _ } = param;
walk_list!(visitor, visit_attribute, attrs);
try_visit!(visitor.visit_pat(pat));
try_visit!(visitor.visit_ty(ty));
V::Result::output()
}
pub fn walk_arm<'a, V: Visitor<'a>>(visitor: &mut V, arm: &'a Arm) -> V::Result {
let Arm { attrs, pat, guard, body, span: _, id: _, is_placeholder: _ } = arm;
walk_list!(visitor, visit_attribute, attrs);
try_visit!(visitor.visit_pat(pat));
visit_opt!(visitor, visit_expr, guard);
visit_opt!(visitor, visit_expr, body);
V::Result::output()
}
pub fn walk_vis<'a, V: Visitor<'a>>(visitor: &mut V, vis: &'a Visibility) -> V::Result {
let Visibility { kind, span: _, tokens: _ } = vis;
match kind {
VisibilityKind::Restricted { path, id, shorthand: _ } => {
try_visit!(visitor.visit_path(path, *id));
}
VisibilityKind::Public | VisibilityKind::Inherited => {}
}
V::Result::output()
}
pub fn walk_attribute<'a, V: Visitor<'a>>(visitor: &mut V, attr: &'a Attribute) -> V::Result {
let Attribute { kind, id: _, style: _, span: _ } = attr;
match kind {
AttrKind::Normal(normal) => {
let NormalAttr { item, tokens: _ } = &**normal;
let AttrItem { unsafety: _, path, args, tokens: _ } = item;
try_visit!(visitor.visit_path(path, DUMMY_NODE_ID));
try_visit!(walk_attr_args(visitor, args));
}
AttrKind::DocComment(_kind, _sym) => {}
}
V::Result::output()
}
pub fn walk_attr_args<'a, V: Visitor<'a>>(visitor: &mut V, args: &'a AttrArgs) -> V::Result {
match args {
AttrArgs::Empty => {}
AttrArgs::Delimited(_args) => {}
AttrArgs::Eq { expr, .. } => try_visit!(visitor.visit_expr(expr)),
}
V::Result::output()
}
fn walk_define_opaques<'a, V: Visitor<'a>>(
visitor: &mut V,
define_opaque: &'a Option<ThinVec<(NodeId, Path)>>,
) -> V::Result {
if let Some(define_opaque) = define_opaque {
for (id, path) in define_opaque {
try_visit!(visitor.visit_path(path, *id));
}
}
V::Result::output()
}
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