From 1f3dea60d31606e6d8a0ac634baa34763508d2ba Mon Sep 17 00:00:00 2001
From: gabime <gmelman1@gmail.com>
Date: Wed, 17 Jul 2019 14:38:01 +0300
Subject: [PATCH] try to prevent optimizer to remove null sink code altogether

---
 include/spdlog/sinks/null_sink.h | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/include/spdlog/sinks/null_sink.h b/include/spdlog/sinks/null_sink.h
index 44a45a3e..3e374893 100644
--- a/include/spdlog/sinks/null_sink.h
+++ b/include/spdlog/sinks/null_sink.h
@@ -8,6 +8,7 @@
 #include "spdlog/details/synchronous_factory.h"
 
 #include <mutex>
+#include <stdio.h>
 
 namespace spdlog {
 namespace sinks {
@@ -16,7 +17,16 @@ template<typename Mutex>
 class null_sink : public base_sink<Mutex>
 {
 protected:
-    void sink_it_(const details::log_msg &) override {}
+    void sink_it_(const details::log_msg &msg) override
+    {
+        // prevent optimizer to remove this sink altogether (and do useful check while at it).
+        if(msg.level == level::off)
+        {
+            printf("Should never not be called if level is off!\n");
+        }
+        assert(msg.level != level::off);
+
+    }
     void flush_() override {}
 };