From ea839861e5e18fbbeea68b6a73fea96f13059cc4 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Fri, 1 May 2020 17:30:47 +0200
Subject: [PATCH] AK: Make Checked.h work with Clang

Apparently Clang does not have __builtin_foo_overflow_p()

Fixes #2044.
---
 AK/Checked.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/AK/Checked.h b/AK/Checked.h
index ac98519678..beb1bdf8a6 100644
--- a/AK/Checked.h
+++ b/AK/Checked.h
@@ -237,13 +237,27 @@ public:
     template<typename U, typename V>
     static bool addition_would_overflow(U u, V v)
     {
+#ifdef __clang__
+        Checked checked;
+        checked = u;
+        checked += v;
+        return checked.has_overflow();
+#else
         return __builtin_add_overflow_p(u, v, (T)0);
+#endif
     }
 
     template<typename U, typename V, typename X>
     static bool multiplication_would_overflow(U u, V v)
     {
+#ifdef __clang__
+        Checked checked;
+        checked = u;
+        checked *= v;
+        return checked.has_overflow();
+#else
         return __builtin_mul_overflow_p(u, v, (T)0);
+#endif
     }
 
     template<typename U, typename V, typename X>