Port #[rustc_object_lifetime_default] to the new attribute parsing infrastructure

Author: JonathanBrouwer

compiler/rustc_attr_data_structures/src/attributes.rs

@@ -287,6 +287,9 @@ pub enum AttributeKind {
     /// Represents [`#[repr]`](https://doc.rust-lang.org/stable/reference/type-layout.html#representations).
     Repr(ThinVec<(ReprAttr, Span)>),
 
+    /// Represents `#[rustc_object_lifetime_default]`.
+    RustcObjectLifetimeDefault,
+
     /// Represents `#[rustc_skip_during_method_dispatch]`.
     SkipDuringMethodDispatch { array: bool, boxed_slice: bool, span: Span },
 

compiler/rustc_attr_data_structures/src/encode_cross_crate.rs

@@ -37,6 +37,7 @@ impl AttributeKind {
             NoMangle(..) => No,
             Optimize(..) => No,
             PubTransparent(..) => Yes,
+            RustcObjectLifetimeDefault => No,
             SkipDuringMethodDispatch { .. } => No,
             TrackCaller(..) => Yes,
             Used { .. } => No,

compiler/rustc_attr_parsing/src/attributes/mod.rs

@@ -36,6 +36,7 @@ pub(crate) mod lint_helpers;
 pub(crate) mod loop_match;
 pub(crate) mod must_use;
 pub(crate) mod repr;
+pub(crate) mod rustc_internal;
 pub(crate) mod semantics;
 pub(crate) mod stability;
 pub(crate) mod traits;

compiler/rustc_attr_parsing/src/attributes/rustc_internal.rs

@@ -0,0 +1,25 @@
+use rustc_attr_data_structures::AttributeKind;
+use rustc_feature::{AttributeTemplate, template};
+use rustc_span::sym;
+
+use crate::attributes::{AttributeOrder, OnDuplicate, SingleAttributeParser};
+use crate::context::{AcceptContext, Stage};
+use crate::parser::ArgParser;
+
+pub(crate) struct RustcObjectLifetimeDefaultParser;
+
+impl<S: Stage> SingleAttributeParser<S> for RustcObjectLifetimeDefaultParser {
+    const PATH: &[rustc_span::Symbol] = &[sym::rustc_object_lifetime_default];
+    const ATTRIBUTE_ORDER: AttributeOrder = AttributeOrder::KeepFirst;
+    const ON_DUPLICATE: OnDuplicate<S> = OnDuplicate::Error;
+    const TEMPLATE: AttributeTemplate = template!(Word);
+
+    fn convert(cx: &mut AcceptContext<'_, '_, S>, args: &ArgParser<'_>) -> Option<AttributeKind> {
+        if let Err(span) = args.no_args() {
+            cx.expected_no_args(span);
+            return None;
+        }
+
+        Some(AttributeKind::RustcObjectLifetimeDefault)
+    }
+}

compiler/rustc_attr_parsing/src/context.rs

@@ -27,6 +27,7 @@ use crate::attributes::lint_helpers::{AsPtrParser, PubTransparentParser};
 use crate::attributes::loop_match::{ConstContinueParser, LoopMatchParser};
 use crate::attributes::must_use::MustUseParser;
 use crate::attributes::repr::{AlignParser, ReprParser};
+use crate::attributes::rustc_internal::RustcObjectLifetimeDefaultParser;
 use crate::attributes::semantics::MayDangleParser;
 use crate::attributes::stability::{
     BodyStabilityParser, ConstStabilityIndirectParser, ConstStabilityParser, StabilityParser,
@@ -130,6 +131,7 @@ attribute_parsers!(
         Single<OptimizeParser>,
         Single<PubTransparentParser>,
         Single<RustcForceInlineParser>,
+        Single<RustcObjectLifetimeDefaultParser>,
         Single<SkipDuringMethodDispatchParser>,
         Single<TrackCallerParser>,
         Single<TransparencyParser>,

compiler/rustc_passes/src/check_attr.rs

@@ -164,7 +164,9 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                 }
                 Attribute::Parsed(AttributeKind::Repr(_)) => { /* handled below this loop and elsewhere */
                 }
-
+                Attribute::Parsed(AttributeKind::RustcObjectLifetimeDefault) => {
+                    self.check_object_lifetime_default(hir_id);
+                }
                 &Attribute::Parsed(AttributeKind::PubTransparent(attr_span)) => {
                     self.check_rustc_pub_transparent(attr_span, span, attrs)
                 }
@@ -301,7 +303,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                         [sym::no_implicit_prelude, ..] => {
                             self.check_generic_attr(hir_id, attr, target, Target::Mod)
                         }
-                        [sym::rustc_object_lifetime_default, ..] => self.check_object_lifetime_default(hir_id),
                         [sym::proc_macro, ..] => {
                             self.check_proc_macro(hir_id, target, ProcMacroKind::FunctionLike)
                         }