From 1953f26fb8b363185614c2bbf51d82266521b143 Mon Sep 17 00:00:00 2001
From: Hashem Aldhaheri <aenawi@gmail.com>
Date: Sat, 19 Sep 2026 07:09:03 +0400
Subject: [PATCH] build: link libatomic on Linux static builds

The perf prebuilt archive references __atomic_compare_exchange from the
buffer manager's 16-byte atomics, and nothing on the link line provides
it, so LBUG_LINUX_VARIANT=perf fails to link. Link libatomic alongside
libstdc++; with --as-needed, compat builds are unchanged.
---
 build.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/build.rs b/build.rs
index 8347d05..2b96a50 100644
--- a/build.rs
+++ b/build.rs
@@ -99,6 +99,11 @@ fn link_libraries(link_bundled_deps: bool) {
             println!("cargo:rustc-link-lib=dylib=c++");
         } else {
             println!("cargo:rustc-link-lib=dylib=stdc++");
+            // The perf build's buffer manager does 16-byte atomic operations,
+            // which GCC lowers to libatomic calls (`__atomic_compare_exchange`).
+            // The linker passes --as-needed, so builds that don't use it
+            // (compat) get no extra runtime dependency.
+            println!("cargo:rustc-link-lib=dylib=atomic");
         }
 
         link_openssl();