diff --git a/compiler/rustc_attr_parsing/src/attributes/cfg_old.rs b/compiler/rustc_attr_parsing/src/attributes/cfg_old.rs
index adae3fa635f4..29be000d476d 100644
--- a/compiler/rustc_attr_parsing/src/attributes/cfg_old.rs
+++ b/compiler/rustc_attr_parsing/src/attributes/cfg_old.rs
@@ -4,8 +4,6 @@ use rustc_feature::{Features, GatedCfg, find_gated_cfg};
 use rustc_hir::RustcVersion;
 use rustc_hir::lints::AttributeLintKind;
 use rustc_session::Session;
-use rustc_session::config::ExpectedValues;
-use rustc_session::lint::builtin::UNEXPECTED_CFGS;
 use rustc_session::lint::{BuiltinLintDiag, Lint};
 use rustc_session::parse::feature_err;
 use rustc_span::{Span, Symbol, sym};
@@ -37,44 +35,6 @@ pub struct Condition {
     pub span: Span,
 }
 
-/// Tests if a cfg-pattern matches the cfg set
-pub fn cfg_matches(
-    cfg: &MetaItemInner,
-    sess: &Session,
-    lint_emitter: impl CfgMatchesLintEmitter,
-    features: Option<&Features>,
-) -> bool {
-    eval_condition(cfg, sess, features, &mut |cfg| {
-        try_gate_cfg(cfg.name, cfg.span, sess, features);
-        match sess.psess.check_config.expecteds.get(&cfg.name) {
-            Some(ExpectedValues::Some(values)) if !values.contains(&cfg.value) => {
-                lint_emitter.emit_span_lint(
-                    sess,
-                    UNEXPECTED_CFGS,
-                    cfg.span,
-                    BuiltinLintDiag::AttributeLint(AttributeLintKind::UnexpectedCfgValue(
-                        (cfg.name, cfg.name_span),
-                        cfg.value.map(|v| (v, cfg.value_span.unwrap())),
-                    )),
-                );
-            }
-            None if sess.psess.check_config.exhaustive_names => {
-                lint_emitter.emit_span_lint(
-                    sess,
-                    UNEXPECTED_CFGS,
-                    cfg.span,
-                    BuiltinLintDiag::AttributeLint(AttributeLintKind::UnexpectedCfgName(
-                        (cfg.name, cfg.name_span),
-                        cfg.value.map(|v| (v, cfg.value_span.unwrap())),
-                    )),
-                );
-            }
-            _ => { /* not unexpected */ }
-        }
-        sess.psess.config.contains(&(cfg.name, cfg.value))
-    })
-}
-
 pub fn try_gate_cfg(name: Symbol, span: Span, sess: &Session, features: Option<&Features>) {
     let gate = find_gated_cfg(|sym| sym == name);
     if let (Some(feats), Some(gated_cfg)) = (features, gate) {
diff --git a/src/librustdoc/passes/check_doc_cfg.rs b/src/librustdoc/passes/check_doc_cfg.rs
index 63dc375a13c6..9e7fae5e14e4 100644
--- a/src/librustdoc/passes/check_doc_cfg.rs
+++ b/src/librustdoc/passes/check_doc_cfg.rs
@@ -1,9 +1,8 @@
-#![allow(dead_code, unused_imports)]
-
-use rustc_hir::HirId;
+use rustc_attr_parsing::{ShouldEmit, eval_config_entry};
+use rustc_hir::attrs::AttributeKind;
 use rustc_hir::def_id::LocalDefId;
+use rustc_hir::{Attribute, HirId};
 use rustc_middle::ty::TyCtxt;
-use rustc_span::sym;
 
 use super::Pass;
 use crate::clean::{Attributes, Crate, Item};
@@ -16,59 +15,58 @@ pub(crate) const CHECK_DOC_CFG: Pass = Pass {
     description: "checks `#[doc(cfg(...))]` for stability feature and unexpected cfgs",
 };
 
-pub(crate) fn check_doc_cfg(krate: Crate, _cx: &mut DocContext<'_>) -> Crate {
-    // let mut checker = DocCfgChecker { cx };
-    // checker.visit_crate(&krate);
+pub(crate) fn check_doc_cfg(krate: Crate, cx: &mut DocContext<'_>) -> Crate {
+    let mut checker = DocCfgChecker { cx };
+    checker.visit_crate(&krate);
     krate
 }
 
-// struct RustdocCfgMatchesLintEmitter<'a>(TyCtxt<'a>, HirId);
+struct RustdocCfgMatchesLintEmitter<'a>(TyCtxt<'a>, HirId);
 
-// impl<'a> rustc_attr_parsing::CfgMatchesLintEmitter for RustdocCfgMatchesLintEmitter<'a> {
-//     fn emit_span_lint(
-//         &self,
-//         sess: &rustc_session::Session,
-//         lint: &'static rustc_lint::Lint,
-//         sp: rustc_span::Span,
-//         builtin_diag: rustc_lint_defs::BuiltinLintDiag,
-//     ) {
-//         self.0.node_span_lint(lint, self.1, sp, |diag| {
-//             rustc_lint::decorate_builtin_lint(sess, Some(self.0), builtin_diag, diag)
-//         });
-//     }
-// }
+impl<'a> rustc_attr_parsing::CfgMatchesLintEmitter for RustdocCfgMatchesLintEmitter<'a> {
+    fn emit_span_lint(
+        &self,
+        sess: &rustc_session::Session,
+        lint: &'static rustc_lint::Lint,
+        sp: rustc_span::Span,
+        builtin_diag: rustc_lint_defs::BuiltinLintDiag,
+    ) {
+        self.0.node_span_lint(lint, self.1, sp, |diag| {
+            rustc_lint::decorate_builtin_lint(sess, Some(self.0), builtin_diag, diag)
+        });
+    }
+}
 
-// struct DocCfgChecker<'a, 'tcx> {
-//     cx: &'a mut DocContext<'tcx>,
-// }
+struct DocCfgChecker<'a, 'tcx> {
+    cx: &'a mut DocContext<'tcx>,
+}
 
-// impl DocCfgChecker<'_, '_> {
-//     fn check_attrs(&mut self, attrs: &Attributes, did: LocalDefId) {
-//         for attr in &attrs.other_attrs {
-//             let Attribute::Parsed(AttributeKind::Doc(d)) = attr else { continue };
-//             let Some(doc_cfg) = d.cfg else { continue };
+impl DocCfgChecker<'_, '_> {
+    fn check_attrs(&mut self, attrs: &Attributes, did: LocalDefId) {
+        for attr in &attrs.other_attrs {
+            let Attribute::Parsed(AttributeKind::Doc(d)) = attr else { continue };
 
-//             if let Some([cfg_mi]) = doc_cfg.meta_item_list() {
-//                 let _ = rustc_attr_parsing::cfg_matches(
-//                     cfg_mi,
-//                     &self.cx.tcx.sess,
-//                     RustdocCfgMatchesLintEmitter(
-//                         self.cx.tcx,
-//                         self.cx.tcx.local_def_id_to_hir_id(did),
-//                     ),
-//                     Some(self.cx.tcx.features()),
-//                 );
-//             }
-//         }
-//     }
-// }
+            for doc_cfg in &d.cfg {
+                let _ = eval_config_entry(
+                    &self.cx.tcx.sess,
+                    doc_cfg,
+                    &RustdocCfgMatchesLintEmitter(
+                        self.cx.tcx,
+                        self.cx.tcx.local_def_id_to_hir_id(did),
+                    ),
+                    ShouldEmit::ErrorsAndLints,
+                );
+            }
+        }
+    }
+}
 
-// impl DocVisitor<'_> for DocCfgChecker<'_, '_> {
-//     fn visit_item(&mut self, item: &'_ Item) {
-//         if let Some(Some(local_did)) = item.def_id().map(|did| did.as_local()) {
-//             self.check_attrs(&item.attrs, local_did);
-//         }
+impl DocVisitor<'_> for DocCfgChecker<'_, '_> {
+    fn visit_item(&mut self, item: &'_ Item) {
+        if let Some(Some(local_did)) = item.def_id().map(|did| did.as_local()) {
+            self.check_attrs(&item.attrs, local_did);
+        }
 
-//         self.visit_item_recur(item);
-//     }
-// }
+        self.visit_item_recur(item);
+    }
+}