Use uname() instead of CMAKE_SYSTEM

fix #3235

louloulibs/louloulibs.h.cmake

-#define SYSTEM_NAME "${CMAKE_SYSTEM}"
 #cmakedefine ICONV_SECOND_ARGUMENT_IS_CONST
 #cmakedefine LIBIDN_FOUND
 #cmakedefine SYSTEMD_FOUND

louloulibs/utils/system.cpp

+#include <logger/logger.hpp>
+#include <utils/system.hpp>
+#include <sys/utsname.h>
+#include <cstring>
+
+using namespace std::string_literals;
+
+namespace utils
+{
+std::string get_system_name()
+{
+  struct utsname uts;
+  const int res = ::uname(&uts);
+  if (res == -1)
+    {
+      log_error("uname failed: ", std::strerror(errno));
+      return "Unknown";
+    }
+  return uts.sysname + " "s + uts.release;
+}
+}
\ No newline at end of file

louloulibs/utils/system.hpp

+#pragma once
+
+#include <string>
+
+namespace utils
+{
+std::string get_system_name();
+}
\ No newline at end of file

louloulibs/xmpp/xmpp_component.cpp

@@ -5,6 +5,7 @@
 
 #include <xmpp/xmpp_component.hpp>
 #include <config/config.hpp>
+#include <utils/system.hpp>
 #include <utils/time.hpp>
 #include <xmpp/auth.hpp>
 #include <xmpp/jid.hpp>
@@ -585,7 +586,7 @@ void XmppComponent::send_version(const std::string& id, const std::string& jid_t
         }
         {
           XmlSubNode os(query, "os");
-          os.set_inner(SYSTEM_NAME);
+          os.set_inner(utils::get_system_name());
         }
     }
     else

tests/utils.cpp

@@ -8,6 +8,7 @@
 #include <utils/empty_if_fixed_server.hpp>
 #include <utils/get_first_non_empty.hpp>
 #include <utils/time.hpp>
+#include <utils/system.hpp>
 #include <utils/scopeguard.hpp>
 
 using namespace std::string_literals;
@@ -151,3 +152,9 @@ TEST_CASE("scope_guard")
   }
   CHECK(res);
 }
+
+TEST_CASE("system_name")
+{
+  CHECK(utils::get_system_name() != "Unknown");
+  CHECK(!utils::get_system_name().empty());
+}
\ No newline at end of file