write death message to std:err and support stream formatting in DIE_MSG*

The stream formatting for DIE_MSG is already wrongly used in
IoContext, EchoClient and LawsDispatcher.

emper/Common.cpp

@@ -10,7 +10,7 @@ void die(const char* message, bool usePerror) {
 	if (usePerror) {
 		std::perror(message);
 	} else {
-		std::cout << message << std::endl;
+		std::cerr << message << std::endl;
 	}
 	exit(EXIT_FAILURE);
 }

emper/Common.hpp

 // SPDX-License-Identifier: LGPL-3.0-or-later
-// Copyright © 2020 Florian Schmaus
+// Copyright © 2020-2021 Florian Schmaus, Florian Fischer
 #pragma once
 
 #include <functional>
@@ -9,8 +9,16 @@ using func_t = std::function<void()>;
 #define STRINGIFY(x) #x
 #define TOSTRING(x) STRINGIFY(x)
 #define DIE die(__FILE__ ":" TOSTRING(__LINE__), false)
-#define DIE_MSG(x) die(__FILE__ ":" TOSTRING(__LINE__) " " #x, false)
-#define DIE_MSG_ERRNO(x) die(__FILE__ ":" TOSTRING(__LINE__) " " #x, true)
+
+// See Debug.hpp why we disable clang-format for the multi statement macro definitions
+// clang-format off
+
+// NOLINTNEXTLINE(bugprone-macro-parentheses)
+#define DIE_MSG(x) do { std::stringstream sst; sst << __FILE__ ":" TOSTRING(__LINE__) " " << x; die(sst.str().c_str(), false); } while (false)
+// NOLINTNEXTLINE(bugprone-macro-parentheses)
+#define DIE_MSG_ERRNO(x) do { std::stringstream sst; sst << __FILE__ ":" TOSTRING(__LINE__) " " << x; die(sst.str().c_str(), true); } while (false)
+
+// clang-format on
 
 // We compile with -fno-exceptions for the moment.
 //#define THROW(x) do { throw std::runtime_error(x); } while (false)