Port #[rustc_do_not_implement_via_object] to the new attribute system

Author: GrigorenkoPV

compiler/rustc_attr_data_structures/src/attributes.rs

@@ -245,6 +245,9 @@ pub enum AttributeKind {
     /// Represents [`#[deprecated]`](https://doc.rust-lang.org/stable/reference/attributes/diagnostics.html#the-deprecated-attribute).
     Deprecation { deprecation: Deprecation, span: Span },
 
+    /// Represents `#[rustc_do_not_implement_via_object]`.
+    DoNotImplementViaObject(Span),
+
     /// Represents [`#[doc]`](https://doc.rust-lang.org/stable/rustdoc/write-documentation/the-doc-attribute.html).
     DocComment { style: AttrStyle, kind: CommentKind, span: Span, comment: Symbol },
 

compiler/rustc_attr_data_structures/src/encode_cross_crate.rs

@@ -26,6 +26,7 @@ impl AttributeKind {
             ConstTrait(..) => No,
             DenyExplicitImpl(..) => No,
             Deprecation { .. } => Yes,
+            DoNotImplementViaObject(..) => No,
             DocComment { .. } => Yes,
             ExportName { .. } => Yes,
             Inline(..) => No,

compiler/rustc_attr_parsing/src/attributes/traits.rs

@@ -68,3 +68,10 @@ impl<S: Stage> NoArgsAttributeParser<S> for DenyExplicitImplParser {
     const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
     const CREATE: fn(Span) -> AttributeKind = AttributeKind::DenyExplicitImpl;
 }
+
+pub(crate) struct DoNotImplementViaObjectParser;
+impl<S: Stage> NoArgsAttributeParser<S> for DoNotImplementViaObjectParser {
+    const PATH: &[Symbol] = &[sym::rustc_do_not_implement_via_object];
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const CREATE: fn(Span) -> AttributeKind = AttributeKind::DoNotImplementViaObject;
+}

compiler/rustc_attr_parsing/src/context.rs

@@ -37,7 +37,8 @@ use crate::attributes::stability::{
     BodyStabilityParser, ConstStabilityIndirectParser, ConstStabilityParser, StabilityParser,
 };
 use crate::attributes::traits::{
-    ConstTraitParser, DenyExplicitImplParser, SkipDuringMethodDispatchParser,
+    ConstTraitParser, DenyExplicitImplParser, DoNotImplementViaObjectParser,
+    SkipDuringMethodDispatchParser,
 };
 use crate::attributes::transparency::TransparencyParser;
 use crate::attributes::{AttributeParser as _, Combine, Single, WithoutArgs};
@@ -144,6 +145,7 @@ attribute_parsers!(
         Single<WithoutArgs<ConstStabilityIndirectParser>>,
         Single<WithoutArgs<ConstTraitParser>>,
         Single<WithoutArgs<DenyExplicitImplParser>>,
+        Single<WithoutArgs<DoNotImplementViaObjectParser>>,
         Single<WithoutArgs<LoopMatchParser>>,
         Single<WithoutArgs<MayDangleParser>>,
         Single<WithoutArgs<NoImplicitPreludeParser>>,

compiler/rustc_hir_analysis/src/collect.rs

@@ -966,8 +966,7 @@ fn trait_def(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::TraitDef {
         });
 
     let deny_explicit_impl = find_attr!(attrs, AttributeKind::DenyExplicitImpl(_));
-    let implement_via_object =
-        !attrs.iter().any(|attr| attr.has_name(sym::rustc_do_not_implement_via_object));
+    let implement_via_object = !find_attr!(attrs, AttributeKind::DoNotImplementViaObject(_));
 
     ty::TraitDef {
         def_id: def_id.to_def_id(),

compiler/rustc_parse/src/validate_attr.rs

@@ -295,6 +295,7 @@ fn emit_malformed_attribute(
             | sym::rustc_skip_during_method_dispatch
             | sym::rustc_pass_by_value
             | sym::rustc_deny_explicit_impl
+            | sym::rustc_do_not_implement_via_object
             | sym::const_trait
             | sym::repr
             | sym::align

compiler/rustc_passes/src/check_attr.rs

@@ -123,7 +123,8 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                 Attribute::Parsed(
                     AttributeKind::SkipDuringMethodDispatch { span: attr_span, .. }
                     | AttributeKind::ConstTrait(attr_span)
-                    | AttributeKind::DenyExplicitImpl(attr_span),
+                    | AttributeKind::DenyExplicitImpl(attr_span)
+                    | AttributeKind::DoNotImplementViaObject(attr_span),
                 ) => {
                     self.check_must_be_applied_to_trait(*attr_span, span, target);
                 }
@@ -282,7 +283,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                         | [sym::rustc_then_this_would_need, ..] => self.check_rustc_dirty_clean(attr),
                         [sym::rustc_coinductive, ..]
                         | [sym::rustc_must_implement_one_of, ..]
-                        | [sym::rustc_do_not_implement_via_object, ..]
                         => self.check_must_be_applied_to_trait(attr.span(), span, target),
                         [sym::collapse_debuginfo, ..] => self.check_collapse_debuginfo(attr, span, target),
                         [sym::must_not_suspend, ..] => self.check_must_not_suspend(attr, span, target),