bjoernager/rust
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Move associated type bounds check to ast lowering

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This makes the check for when associated type bounds more accurate
This commit is contained in:
Michael Goulet 2023-02-14 19:15:43 +00:00
parent b869e84e58
commit e7c490892f
12 changed files with 171 additions and 139 deletions
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33
compiler/rustc_ast_passes/src/ast_validation.rs
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@ -71,10 +71,6 @@ struct AstValidator<'a> {
/// or `Foo::Bar<impl Trait>`
is_impl_trait_banned: bool,
/// Used to ban associated type bounds (i.e., `Type<AssocType: Bounds>`) in
/// certain positions.
is_assoc_ty_bound_banned: bool,
/// See [ForbiddenLetReason]
forbidden_let_reason: Option<ForbiddenLetReason>,
@ -180,30 +176,12 @@ impl<'a> AstValidator<'a> {
}
}
fn with_banned_assoc_ty_bound(&mut self, f: impl FnOnce(&mut Self)) {
let old = mem::replace(&mut self.is_assoc_ty_bound_banned, true);
f(self);
self.is_assoc_ty_bound_banned = old;
}
fn with_impl_trait(&mut self, outer: Option<Span>, f: impl FnOnce(&mut Self)) {
let old = mem::replace(&mut self.outer_impl_trait, outer);
f(self);
self.outer_impl_trait = old;
}
fn visit_assoc_constraint_from_generic_args(&mut self, constraint: &'a AssocConstraint) {
match constraint.kind {
AssocConstraintKind::Equality { .. } => {}
AssocConstraintKind::Bound { .. } => {
if self.is_assoc_ty_bound_banned {
self.session.emit_err(ForbiddenAssocConstraint { span: constraint.span });
}
}
}
self.visit_assoc_constraint(constraint);
}
// Mirrors `visit::walk_ty`, but tracks relevant state.
fn walk_ty(&mut self, t: &'a Ty) {
match &t.kind {
@ -1248,7 +1226,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
// are allowed to contain nested `impl Trait`.
AngleBracketedArg::Constraint(constraint) => {
self.with_impl_trait(None, |this| {
this.visit_assoc_constraint_from_generic_args(constraint);
this.visit_assoc_constraint(constraint);
});
}
}
@ -1373,14 +1351,6 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
visit::walk_param_bound(self, bound)
}
fn visit_variant_data(&mut self, s: &'a VariantData) {
self.with_banned_assoc_ty_bound(|this| visit::walk_struct_def(this, s))
}
fn visit_enum_def(&mut self, enum_definition: &'a EnumDef) {
self.with_banned_assoc_ty_bound(|this| visit::walk_enum_def(this, enum_definition))
}
fn visit_fn(&mut self, fk: FnKind<'a>, span: Span, id: NodeId) {
// Only associated `fn`s can have `self` parameters.
let self_semantic = match fk.ctxt() {
@ -1709,7 +1679,6 @@ pub fn check_crate(session: &Session, krate: &Crate, lints: &mut LintBuffer) ->
outer_impl_trait: None,
disallow_tilde_const: None,
is_impl_trait_banned: false,
is_assoc_ty_bound_banned: false,
forbidden_let_reason: Some(ForbiddenLetReason::GenericForbidden),
lint_buffer: lints,
};