1 files changed, 39 insertions, 0 deletions
diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
index 265779c9374..a023d6161df 100644
--- a/compiler/rustc_lint_defs/src/builtin.rs
+++ b/compiler/rustc_lint_defs/src/builtin.rs
@@ -4945,3 +4945,42 @@ declare_lint! {
         reference: "issue #123757 <https://github.com/rust-lang/rust/issues/123757>",
     };
 }
+
+declare_lint! {
+    /// The `out_of_scope_macro_calls` lint detects `macro_rules` called when they are not in scope,
+    /// above their definition, which may happen in key-value attributes.
+    ///
+    /// ### Example
+    ///
+    /// ```rust
+    /// #![doc = in_root!()]
+    ///
+    /// macro_rules! in_root { () => { "" } }
+    ///
+    /// fn main() {}
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// The scope in which a `macro_rules` item is visible starts at that item and continues
+    /// below it. This is more similar to `let` than to other items, which are in scope both above
+    /// and below their definition.
+    /// Due to a bug `macro_rules` were accidentally in scope inside some key-value attributes
+    /// above their definition. The lint catches such cases.
+    /// To address the issue turn the `macro_rules` into a regularly scoped item by importing it
+    /// with `use`.
+    ///
+    /// This is a [future-incompatible] lint to transition this to a
+    /// hard error in the future.
+    ///
+    /// [future-incompatible]: ../index.md#future-incompatible-lints
+    pub OUT_OF_SCOPE_MACRO_CALLS,
+    Warn,
+    "detects out of scope calls to `macro_rules` in key-value attributes",
+    @future_incompatible = FutureIncompatibleInfo {
+        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reference: "issue #124535 <https://github.com/rust-lang/rust/issues/124535>",
+    };
+}