From f4fde2092b3ad19f7b39fda98f6763a22b69ff1c Mon Sep 17 00:00:00 2001
From: bjorn3 <17426603+bjorn3@users.noreply.github.com>
Date: Thu, 7 Aug 2025 13:13:04 +0000
Subject: [PATCH] Prevent name collisions with internal implementation details

The implementation of the linkage attribute inside extern blocks defines
symbols starting with _rust_extern_with_linkage_. If someone tries to
also define this symbol you will get a symbol conflict or even an ICE.
By adding an unpredictable component to the symbol name, this becomes
less of an issue.
---
 src/constant.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/constant.rs b/src/constant.rs
index a04cfa272376..bec546badc9c 100644
--- a/src/constant.rs
+++ b/src/constant.rs
@@ -310,7 +310,10 @@ fn data_id_for_static(
         // `extern_with_linkage_foo` will instead be initialized to
         // zero.
 
-        let ref_name = format!("_rust_extern_with_linkage_{}", symbol_name);
+        let ref_name = format!(
+            "_rust_extern_with_linkage_{:016x}_{symbol_name}",
+            tcx.stable_crate_id(LOCAL_CRATE)
+        );
         let ref_data_id = module.declare_data(&ref_name, Linkage::Local, false, false).unwrap();
         let mut data = DataDescription::new();
         data.set_align(align);