rustdoc: use anonymous constant for primitives/keywords/attribute docs

Author: mejrs

compiler/rustc_attr_parsing/src/attributes/rustc_internal.rs

@@ -1119,7 +1119,7 @@ pub(crate) struct RustcDocPrimitiveParser;
 
 impl SingleAttributeParser for RustcDocPrimitiveParser {
     const PATH: &[Symbol] = &[sym::rustc_doc_primitive];
-    const ALLOWED_TARGETS: AllowedTargets<'_> = AllowedTargets::AllowList(&[Allow(Target::Mod)]);
+    const ALLOWED_TARGETS: AllowedTargets<'_> = AllowedTargets::AllowList(&[Allow(Target::Const)]);
     const TEMPLATE: AttributeTemplate = template!(NameValueStr: "primitive name");
     const STABILITY: AttributeStability = unstable!(
         rustc_attrs,

compiler/rustc_passes/src/check_attr.rs

@@ -44,7 +44,7 @@ use rustc_session::lint::builtin::{
     MALFORMED_DIAGNOSTIC_FORMAT_LITERALS, MISPLACED_DIAGNOSTIC_ATTRIBUTES, UNUSED_ATTRIBUTES,
 };
 use rustc_span::edition::Edition;
-use rustc_span::{DUMMY_SP, Ident, Span, Symbol, sym};
+use rustc_span::{DUMMY_SP, Ident, Span, Symbol, kw, sym};
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
 use rustc_trait_selection::infer::{TyCtxtInferExt, ValuePairs};
 use rustc_trait_selection::traits::ObligationCtxt;
@@ -1026,18 +1026,11 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
             hir::Node::Item(item) => Some(&item.kind),
             _ => None,
         };
-        match item_kind {
-            Some(ItemKind::Mod(_, module)) => {
-                if !module.item_ids.is_empty() {
-                    self.dcx()
-                        .emit_err(diagnostics::DocKeywordAttributeEmptyMod { span, attr_name });
-                    return;
-                }
-            }
-            _ => {
-                self.dcx().emit_err(diagnostics::DocKeywordAttributeNotMod { span, attr_name });
-                return;
-            }
+        if let Some(ItemKind::Const(ident, _gen, _ty, _rhs)) = item_kind
+            && ident.name == kw::Underscore
+        {
+        } else {
+            self.dcx().emit_err(diagnostics::DocKeywordAttributeNotAnonConst { span, attr_name });
         }
     }
 

compiler/rustc_passes/src/diagnostics.rs

@@ -73,16 +73,8 @@ pub(crate) struct DocAliasNotAnAlias {
 }
 
 #[derive(Diagnostic)]
-#[diag("`#[doc({$attr_name} = \"...\")]` should be used on empty modules")]
-pub(crate) struct DocKeywordAttributeEmptyMod {
-    #[primary_span]
-    pub span: Span,
-    pub attr_name: &'static str,
-}
-
-#[derive(Diagnostic)]
-#[diag("`#[doc({$attr_name} = \"...\")]` should be used on modules")]
-pub(crate) struct DocKeywordAttributeNotMod {
+#[diag("`#[doc({$attr_name} = \"...\")]` should be used on anonymous constants")]
+pub(crate) struct DocKeywordAttributeNotAnonConst {
     #[primary_span]
     pub span: Span,
     pub attr_name: &'static str,

library/core/src/attribute_docs.rs

@@ -82,7 +82,7 @@
 ///
 /// [`unused_must_use`]: ../rustc/lints/listing/warn-by-default.html#unused-must-use
 /// [the `must_use` attribute]: ../reference/attributes/diagnostics.html#the-must_use-attribute
-mod must_use_attribute {}
+const _: () = ();
 
 #[doc(attribute = "allow")]
 //
@@ -144,7 +144,7 @@ mod must_use_attribute {}
 /// [`forbid`]: ./attribute.forbid.html
 /// [`warn`]: ./attribute.warn.html
 /// [`deny`]: ./attribute.deny.html
-mod allow_attribute {}
+const _: () = ();
 
 #[doc(attribute = "cfg")]
 //
@@ -192,7 +192,7 @@ mod allow_attribute {}
 /// [`cfg_attr`]: ../reference/conditional-compilation.html#the-cfg_attr-attribute
 /// [the `cfg` attribute]: ../reference/conditional-compilation.html#the-cfg-attribute
 /// [`if`]: ./keyword.if.html
-mod cfg_attribute {}
+const _: () = ();
 
 #[doc(attribute = "deny")]
 //
@@ -240,7 +240,7 @@ mod cfg_attribute {}
 /// [`allow`]: ./attribute.allow.html
 /// [`warn`]: ./attribute.warn.html
 /// [`deny`]: ./attribute.deny.html
-mod deny_attribute {}
+const _: () = ();
 
 #[doc(attribute = "forbid")]
 //
@@ -276,7 +276,7 @@ mod deny_attribute {}
 /// [the `forbid` attribute]: ../reference/attributes/diagnostics.html#lint-check-attributes
 /// [`allow`]: ./attribute.allow.html
 /// [`warn`]: ./attribute.warn.html
-mod forbid_attribute {}
+const _: () = ();
 
 #[doc(attribute = "deprecated")]
 //
@@ -302,7 +302,7 @@ mod forbid_attribute {}
 /// For more information, see the Reference on [the `deprecated` attribute].
 ///
 /// [the `deprecated` attribute]: ../reference/attributes/diagnostics.html#the-deprecated-attribute
-mod deprecated_attribute {}
+const _: () = ();
 
 #[doc(attribute = "warn")]
 //
@@ -348,7 +348,7 @@ mod deprecated_attribute {}
 /// [`allow`]: ./attribute.allow.html
 /// [`deny`]: ./attribute.deny.html
 /// [`forbid`]: ./attribute.forbid.html
-mod warn_attribute {}
+const _: () = ();
 
 #[doc(attribute = "no_std")]
 //
@@ -404,7 +404,7 @@ mod warn_attribute {}
 /// [`Option`]: option::Option
 /// [`Result`]: result::Result
 /// [the `no_std` attribute]: ../reference/names/preludes.html#the-no_std-attribute
-mod no_std_attribute {}
+const _: () = ();
 
 #[doc(attribute = "inline")]
 //
@@ -444,7 +444,7 @@ mod no_std_attribute {}
 /// For more information, see the Reference on [the `inline` attribute].
 ///
 /// [the `inline` attribute]: ../reference/attributes/codegen.html#the-inline-attribute
-mod inline_attribute {}
+const _: () = ();
 
 #[doc(attribute = "cold")]
 //
@@ -474,7 +474,7 @@ mod inline_attribute {}
 /// For more information, see the Reference on [the `cold` attribute].
 ///
 /// [the `cold` attribute]: ../reference/attributes/codegen.html#the-cold-attribute
-mod cold_attribute {}
+const _: () = ();
 
 #[doc(attribute = "track_caller")]
 //
@@ -505,7 +505,7 @@ mod cold_attribute {}
 /// [`Location::caller`]: panic::Location::caller
 /// [`Option::unwrap`]: Option::unwrap
 /// [the `track_caller` attribute]: ../reference/attributes/codegen.html#the-track_caller-attribute
-mod track_caller_attribute {}
+const _: () = ();
 
 #[doc(attribute = "proc_macro")]
 //
@@ -554,7 +554,7 @@ mod track_caller_attribute {}
 /// [`TokenStream`]: ../proc_macro/struct.TokenStream.html
 /// [function-like procedural macros]: ../reference/procedural-macros.html#the-proc_macro-attribute
 /// [`proc_macro`]: ../proc_macro/index.html
-mod proc_macro_attribute {}
+const _: () = ();
 
 #[doc(attribute = "link_section")]
 //
@@ -580,4 +580,4 @@ mod proc_macro_attribute {}
 /// For more information, see the Reference on [the `link_section` attribute].
 ///
 /// [the `link_section` attribute]: ../reference/abi.html#the-link_section-attribute
-mod link_section_attribute {}
+const _: () = ();