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Deny more ~const trait bounds

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This commit is contained in:
León Orell Valerian Liehr
2023-11-11 15:01:58 +01:00
parent 9ab0749ce3
commit 8ce5d784a6
25 changed files with 444 additions and 134 deletions
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75
compiler/rustc_ast_passes/src/ast_validation.rs
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@@ -40,6 +40,9 @@ enum SelfSemantic {
enum DisallowTildeConstContext<'a> {
TraitObject,
Fn(FnKind<'a>),
Trait(Span),
Impl(Span),
Item,
}
struct AstValidator<'a> {
@@ -110,18 +113,6 @@ impl<'a> AstValidator<'a> {
self.disallow_tilde_const = old;
}
fn with_tilde_const_allowed(&mut self, f: impl FnOnce(&mut Self)) {
self.with_tilde_const(None, f)
}
fn with_banned_tilde_const(
&mut self,
ctx: DisallowTildeConstContext<'a>,
f: impl FnOnce(&mut Self),
) {
self.with_tilde_const(Some(ctx), f)
}
fn check_type_alias_where_clause_location(
&mut self,
ty_alias: &TyAlias,
@@ -173,7 +164,7 @@ impl<'a> AstValidator<'a> {
self.with_impl_trait(Some(t.span), |this| visit::walk_ty(this, t))
}
TyKind::TraitObject(..) => self
.with_banned_tilde_const(DisallowTildeConstContext::TraitObject, |this| {
.with_tilde_const(Some(DisallowTildeConstContext::TraitObject), |this| {
visit::walk_ty(this, t)
}),
TyKind::Path(qself, path) => {
@@ -822,11 +813,9 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
this.visit_vis(&item.vis);
this.visit_ident(item.ident);
if let Const::Yes(_) = constness {
this.with_tilde_const_allowed(|this| this.visit_generics(generics));
} else {
this.visit_generics(generics);
}
let disallowed = matches!(constness, Const::No)
.then(|| DisallowTildeConstContext::Impl(item.span));
this.with_tilde_const(disallowed, |this| this.visit_generics(generics));
this.visit_trait_ref(t);
this.visit_ty(self_ty);
@@ -840,10 +829,10 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
polarity,
defaultness,
constness,
generics: _,
generics,
of_trait: None,
self_ty,
items: _,
items,
}) => {
let error =
|annotation_span, annotation, only_trait: bool| errors::InherentImplCannot {
@@ -875,6 +864,14 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
if let &Const::Yes(span) = constness {
self.err_handler().emit_err(error(span, "`const`", true));
}
self.visit_vis(&item.vis);
self.visit_ident(item.ident);
self.with_tilde_const(None, |this| this.visit_generics(generics));
self.visit_ty(self_ty);
walk_list!(self, visit_assoc_item, items, AssocCtxt::Impl);
walk_list!(self, visit_attribute, &item.attrs);
return; // Avoid visiting again.
}
ItemKind::Fn(box Fn { defaultness, sig, generics, body }) => {
self.check_defaultness(item.span, *defaultness);
@@ -955,8 +952,10 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
// context for the supertraits.
this.visit_vis(&item.vis);
this.visit_ident(item.ident);
this.visit_generics(generics);
this.with_tilde_const_allowed(|this| {
let disallowed =
(!is_const_trait).then(|| DisallowTildeConstContext::Trait(item.span));
this.with_tilde_const(disallowed, |this| {
this.visit_generics(generics);
walk_list!(this, visit_param_bound, bounds, BoundKind::SuperTraits)
});
walk_list!(this, visit_assoc_item, items, AssocCtxt::Trait);
@@ -976,16 +975,11 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
}
}
ItemKind::Struct(vdata, generics) => match vdata {
// Duplicating the `Visitor` logic allows catching all cases
// of `Anonymous(Struct, Union)` outside of a field struct or union.
//
// Inside `visit_ty` the validator catches every `Anonymous(Struct, Union)` it
// encounters, and only on `ItemKind::Struct` and `ItemKind::Union`
// it uses `visit_ty_common`, which doesn't contain that specific check.
VariantData::Struct(fields, ..) => {
self.visit_vis(&item.vis);
self.visit_ident(item.ident);
self.visit_generics(generics);
// Permit `Anon{Struct,Union}` as field type.
walk_list!(self, visit_struct_field_def, fields);
walk_list!(self, visit_attribute, &item.attrs);
return;
@@ -1001,6 +995,7 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
self.visit_vis(&item.vis);
self.visit_ident(item.ident);
self.visit_generics(generics);
// Permit `Anon{Struct,Union}` as field type.
walk_list!(self, visit_struct_field_def, fields);
walk_list!(self, visit_attribute, &item.attrs);
return;
@@ -1189,15 +1184,18 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
if let Some(reason) = &self.disallow_tilde_const =>
{
let reason = match reason {
DisallowTildeConstContext::TraitObject => {
errors::TildeConstReason::TraitObject
}
DisallowTildeConstContext::Fn(FnKind::Closure(..)) => {
errors::TildeConstReason::Closure
}
DisallowTildeConstContext::Fn(FnKind::Fn(_, ident, ..)) => {
errors::TildeConstReason::Function { ident: ident.span }
}
&DisallowTildeConstContext::Trait(span) => errors::TildeConstReason::Trait { span },
&DisallowTildeConstContext::Impl(span) => errors::TildeConstReason::Impl { span },
DisallowTildeConstContext::TraitObject => {
errors::TildeConstReason::TraitObject
}
DisallowTildeConstContext::Item => errors::TildeConstReason::Item,
};
self.err_handler()
.emit_err(errors::TildeConstDisallowed { span: bound.span(), reason });
@@ -1305,7 +1303,6 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
|| matches!(fk.ctxt(), Some(FnCtxt::Assoc(_)) if self.in_const_trait_or_impl);
let disallowed = (!tilde_const_allowed).then(|| DisallowTildeConstContext::Fn(fk));
self.with_tilde_const(disallowed, |this| visit::walk_fn(this, fk));
}
@@ -1374,18 +1371,6 @@ impl<'a> Visitor<'a> for AstValidator<'a> {
}
match &item.kind {
AssocItemKind::Type(box TyAlias { generics, bounds, ty, .. })
if ctxt == AssocCtxt::Trait =>
{
self.visit_vis(&item.vis);
self.visit_ident(item.ident);
walk_list!(self, visit_attribute, &item.attrs);
self.with_tilde_const_allowed(|this| {
this.visit_generics(generics);
walk_list!(this, visit_param_bound, bounds, BoundKind::Bound);
});
walk_list!(self, visit_ty, ty);
}
AssocItemKind::Fn(box Fn { sig, generics, body, .. })
if self.in_const_trait_or_impl
|| ctxt == AssocCtxt::Trait
@@ -1537,7 +1522,7 @@ pub fn check_crate(
in_const_trait_or_impl: false,
has_proc_macro_decls: false,
outer_impl_trait: None,
disallow_tilde_const: None,
disallow_tilde_const: Some(DisallowTildeConstContext::Item),
is_impl_trait_banned: false,
lint_buffer: lints,
};