Auto merge of #79752 - cjgillot:dead-alien, r=lcnr

Visit ForeignItems when marking dead code

Follow-up to #79318

r? `@lcnr`

1 files changed, 19 insertions, 0 deletions

diff --git a/src/test/ui/lint/dead-code/type-in-foreign.rs b/src/test/ui/lint/dead-code/type-in-foreign.rs
new file mode 100644
index 00000000000..b6c593f316f
--- /dev/null
+++ b/src/test/ui/lint/dead-code/type-in-foreign.rs
@@ -0,0 +1,19 @@
+// Verify that we do not warn on types that are used by foreign functions.
+// check-pass
+#![deny(dead_code)]
+
+#[repr(C)]
+struct Type(u8);
+
+#[repr(C)]
+struct Param(u8);
+
+extern "C" {
+    #[allow(dead_code)]
+    fn hey(t: Param);
+
+    #[allow(dead_code)]
+    static much: Type;
+}
+
+fn main() {}