From 8f472e8b5c0923a36a3cd90c3d5fc990943dd034 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Le=C3=B3n=20Orell=20Valerian=20Liehr?= <me@fmease.dev>
Date: Thu, 14 Aug 2025 03:29:51 +0200
Subject: [PATCH] Add regression test for a former ICE involving helper
 attributes containing interpolated tokens
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Co-authored-by: Jana Dönszelmann <jana@donsz.nl>
---
 .../auxiliary/derive_macro_with_helper.rs     |  8 ++++++++
 .../helper-attr-interpolated-non-lit-arg.rs   | 20 +++++++++++++++++++
 2 files changed, 28 insertions(+)
 create mode 100644 tests/ui/attributes/auxiliary/derive_macro_with_helper.rs
 create mode 100644 tests/ui/attributes/helper-attr-interpolated-non-lit-arg.rs

diff --git a/tests/ui/attributes/auxiliary/derive_macro_with_helper.rs b/tests/ui/attributes/auxiliary/derive_macro_with_helper.rs
new file mode 100644
index 0000000000000..128af50ce3691
--- /dev/null
+++ b/tests/ui/attributes/auxiliary/derive_macro_with_helper.rs
@@ -0,0 +1,8 @@
+extern crate proc_macro;
+
+use proc_macro::TokenStream;
+
+#[proc_macro_derive(Derive, attributes(arg))]
+pub fn derive(_: TokenStream) -> TokenStream {
+    TokenStream::new()
+}
diff --git a/tests/ui/attributes/helper-attr-interpolated-non-lit-arg.rs b/tests/ui/attributes/helper-attr-interpolated-non-lit-arg.rs
new file mode 100644
index 0000000000000..17c9ad1bd48e6
--- /dev/null
+++ b/tests/ui/attributes/helper-attr-interpolated-non-lit-arg.rs
@@ -0,0 +1,20 @@
+// Regression test for <https://github.com/rust-lang/rust/issues/140612>.
+//@ proc-macro: derive_macro_with_helper.rs
+//@ edition: 2018
+//@ check-pass
+
+macro_rules! expand {
+    ($text:expr) => {
+        #[derive(derive_macro_with_helper::Derive)]
+        // This inert attr is completely valid because it follows the grammar
+        // `#` `[` SimplePath DelimitedTokenStream `]`.
+        // However, we used to incorrectly delay a bug here and ICE when trying to parse `$text` as
+        // the inside of a "meta item list" which may only begin with literals or paths.
+        #[arg($text)]
+        pub struct Foo;
+    };
+}
+
+expand!(1 + 1);
+
+fn main() {}