From d9c2447999a7d61cf60e0012606702c9225715f7 Mon Sep 17 00:00:00 2001
From: Timothy Flynn <trflynn89@pm.me>
Date: Mon, 12 Jul 2021 11:46:05 -0400
Subject: [PATCH] AK: Add free function to wrap around __atomic_is_lock_free
 built-in

Note: this exact implementation is needed for __atomic_is_lock_free to
link with both GCC (for the SerenityOS build) and Clang (for the Fuzzer
build). The size argument must be a compile-time constant, otherwise it
fails to link with both compilers. Alternatively, the following
definition links with GCC but fails with Clang:

    template<size_t S>
    static inline bool atomic_is_lock_free(volatile void* ptr = nullptr)
    {
        return __atomic_is_lock_free(S, ptr);
    }
---
 AK/Atomic.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/AK/Atomic.h b/AK/Atomic.h
index 61a8e41385..ec7191250a 100644
--- a/AK/Atomic.h
+++ b/AK/Atomic.h
@@ -133,6 +133,12 @@ static inline void atomic_store(volatile T** var, std::nullptr_t, MemoryOrder or
     __atomic_store_n(const_cast<V**>(var), nullptr, order);
 }
 
+template<typename T>
+static inline bool atomic_is_lock_free(volatile T* ptr = nullptr) noexcept
+{
+    return __atomic_is_lock_free(sizeof(T), ptr);
+}
+
 template<typename T, MemoryOrder DefaultMemoryOrder = AK::MemoryOrder::memory_order_seq_cst>
 class Atomic {
     T m_value { 0 };