Rollup merge of #134202 - nnethercote:rm-existing_doc_keyword, r=GuillaumeGomez

Remove `rustc::existing_doc_keyword` lint

The check doesn't require a lint.

r? ``@GuillaumeGomez``

compiler/rustc_passes/Cargo.toml

@@ -16,7 +16,6 @@ rustc_feature = { path = "../rustc_feature" }
 rustc_fluent_macro = { path = "../rustc_fluent_macro" }
 rustc_hir = { path = "../rustc_hir" }
 rustc_index = { path = "../rustc_index" }
-rustc_lexer = { path = "../rustc_lexer" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_middle = { path = "../rustc_middle" }
 rustc_privacy = { path = "../rustc_privacy" }

compiler/rustc_passes/messages.ftl

@@ -211,8 +211,9 @@ passes_doc_invalid =
 passes_doc_keyword_empty_mod =
     `#[doc(keyword = "...")]` should be used on empty modules
 
-passes_doc_keyword_invalid_ident =
-    `{$doc_keyword}` is not a valid identifier
+passes_doc_keyword_not_keyword =
+    nonexistent keyword `{$keyword}` used in `#[doc(keyword = "...")]`
+    .help = only existing keywords are allowed in core/std
 
 passes_doc_keyword_not_mod =
     `#[doc(keyword = "...")]` should be used on modules

compiler/rustc_passes/src/check_attr.rs

@@ -912,6 +912,13 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
     }
 
     fn check_doc_keyword(&self, meta: &MetaItemInner, hir_id: HirId) {
+        fn is_doc_keyword(s: Symbol) -> bool {
+            // FIXME: Once rustdoc can handle URL conflicts on case insensitive file systems, we
+            // can remove the `SelfTy` case here, remove `sym::SelfTy`, and update the
+            // `#[doc(keyword = "SelfTy")` attribute in `library/std/src/keyword_docs.rs`.
+            s <= kw::Union || s == sym::SelfTy
+        }
+
         let doc_keyword = meta.value_str().unwrap_or(kw::Empty);
         if doc_keyword == kw::Empty {
             self.doc_attr_str_error(meta, "keyword");
@@ -933,10 +940,10 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                 return;
             }
         }
-        if !rustc_lexer::is_ident(doc_keyword.as_str()) {
-            self.dcx().emit_err(errors::DocKeywordInvalidIdent {
+        if !is_doc_keyword(doc_keyword) {
+            self.dcx().emit_err(errors::DocKeywordNotKeyword {
                 span: meta.name_value_literal_span().unwrap_or_else(|| meta.span()),
-                doc_keyword,
+                keyword: doc_keyword,
             });
         }
     }

compiler/rustc_passes/src/errors.rs

@@ -215,6 +215,15 @@ pub(crate) struct DocKeywordEmptyMod {
     pub span: Span,
 }
 
+#[derive(Diagnostic)]
+#[diag(passes_doc_keyword_not_keyword)]
+#[help]
+pub(crate) struct DocKeywordNotKeyword {
+    #[primary_span]
+    pub span: Span,
+    pub keyword: Symbol,
+}
+
 #[derive(Diagnostic)]
 #[diag(passes_doc_keyword_not_mod)]
 pub(crate) struct DocKeywordNotMod {
@@ -222,14 +231,6 @@ pub(crate) struct DocKeywordNotMod {
     pub span: Span,
 }
 
-#[derive(Diagnostic)]
-#[diag(passes_doc_keyword_invalid_ident)]
-pub(crate) struct DocKeywordInvalidIdent {
-    #[primary_span]
-    pub span: Span,
-    pub doc_keyword: Symbol,
-}
-
 #[derive(Diagnostic)]
 #[diag(passes_doc_fake_variadic_not_valid)]
 pub(crate) struct DocFakeVariadicNotValid {