From 1f89e900738b30c15894e57d7bdb1c2dbc089976 Mon Sep 17 00:00:00 2001
From: Nilstrieb <48135649+Nilstrieb@users.noreply.github.com>
Date: Mon, 29 Jan 2024 20:10:01 +0100
Subject: [PATCH] Add test for duplicate lang items

---
 tests/ui/lang-items/duplicate.rs     | 10 ++++++++++
 tests/ui/lang-items/duplicate.stderr | 13 +++++++++++++
 2 files changed, 23 insertions(+)
 create mode 100644 tests/ui/lang-items/duplicate.rs
 create mode 100644 tests/ui/lang-items/duplicate.stderr

diff --git a/tests/ui/lang-items/duplicate.rs b/tests/ui/lang-items/duplicate.rs
new file mode 100644
index 0000000000000..f88d23544145a
--- /dev/null
+++ b/tests/ui/lang-items/duplicate.rs
@@ -0,0 +1,10 @@
+// normalize-stderr-test "loaded from .*libcore-.*.rlib" -> "loaded from SYSROOT/libcore-*.rlib"
+#![feature(lang_items)]
+
+#[lang = "sized"]
+trait Sized {}
+//~^ ERROR: duplicate lang item
+
+#[lang = "tuple_trait"]
+pub trait Tuple {}
+// no error
diff --git a/tests/ui/lang-items/duplicate.stderr b/tests/ui/lang-items/duplicate.stderr
new file mode 100644
index 0000000000000..aaa8f5e605afa
--- /dev/null
+++ b/tests/ui/lang-items/duplicate.stderr
@@ -0,0 +1,13 @@
+error[E0152]: found duplicate lang item `sized`
+  --> $DIR/duplicate.rs:5:1
+   |
+LL | trait Sized {}
+   | ^^^^^^^^^^^^^^
+   |
+   = note: the lang item is first defined in crate `core` (which `std` depends on)
+   = note: first definition in `core` loaded from SYSROOT/libcore-*.rlib
+   = note: second definition in the local crate (`duplicate`)
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0152`.