Add trace functionality for debug builds

4 files changed, 87 insertions, 0 deletions

diff --git a/windns/src/windns/consoletracesink.cpp b/windns/src/windns/consoletracesink.cpp
new file mode 100644
index 0000000000..6e3d415303
--- /dev/null
+++ b/windns/src/windns/consoletracesink.cpp
@@ -0,0 +1,8 @@
+#include "stdafx.h"
+#include "consoletracesink.h"
+#include <iostream>
+
+void ConsoleTraceSink::trace(const wchar_t *msg)
+{
+	std::wcout << msg << std::endl;
+}
diff --git a/windns/src/windns/consoletracesink.h b/windns/src/windns/consoletracesink.h
new file mode 100644
index 0000000000..765fb4a2a0
--- /dev/null
+++ b/windns/src/windns/consoletracesink.h
@@ -0,0 +1,8 @@
+#pragma once
+
+#include "itracesink.h"
+
+struct ConsoleTraceSink : public ITraceSink
+{
+	void trace(const wchar_t *msg) override;
+};
diff --git a/windns/src/windns/itracesink.h b/windns/src/windns/itracesink.h
new file mode 100644
index 0000000000..496a7df1b9
--- /dev/null
+++ b/windns/src/windns/itracesink.h
@@ -0,0 +1,48 @@
+#pragma once
+
+#include <sstream>
+
+struct ITraceSink
+{
+	virtual ~ITraceSink() = 0
+	{
+	}
+
+	virtual void trace(const wchar_t *msg) = 0;
+};
+
+struct NullTraceSink : public ITraceSink
+{
+	void trace(const wchar_t *) override
+	{
+	}
+};
+
+#ifdef _DEBUG
+#define TRACING_ENABLED 1
+#else
+#define TRACING_ENABLED 0
+#endif
+
+#if TRACING_ENABLED == 1
+
+#include "macroargument.h"
+#define XTRACE(...) VFUNC(XTRACE, __VA_ARGS__)
+
+#define XTRACE1(x)\
+{\
+std::wstringstream xtrace_ss;\
+xtrace_ss << __FUNCTIONW__ << L": " << x;\
+m_traceSink->trace(xtrace_ss.str().c_str());\
+}
+
+#define XTRACE2(x, y)\
+{\
+std::wstringstream xtrace_ss;\
+xtrace_ss << __FUNCTIONW__ << L": " << x << L" " << y;\
+m_traceSink->trace(xtrace_ss.str().c_str());\
+}
+
+#else
+#define XTRACE(...)
+#endif
diff --git a/windns/src/windns/macroargument.h b/windns/src/windns/macroargument.h
new file mode 100644
index 0000000000..bb27c124c8
--- /dev/null
+++ b/windns/src/windns/macroargument.h
@@ -0,0 +1,23 @@
+#pragma once
+
+//http://www.neff.co.at/2017/04/04/Overloading-Macros-on-the-Number-of-Arguments.html
+
+// Some auxiliary macros
+#define EMPTY()
+#define EXPAND(X) X
+#define CONCAT(X,Y) X##Y
+
+// Get number of arguments passed by __VA_ARGS__
+// http://stackoverflow.com/questions/2124339/c-preprocessor-va-args-number-of-arguments
+// NUMARGS: all arguments must be castable to int
+// NARGS: pure preprocessor macro, maximum 9 arguments
+#define NUMARGS(...)  (sizeof((int[]){__VA_ARGS__})/sizeof(int))
+#define NARGS(...)  _NARGS_I(_AUGMENT(__VA_ARGS__))
+#define _AUGMENT(...) _UNUSED_, __VA_ARGS__
+#define _NARGS_I(...) EXPAND(_ARG_N(__VA_ARGS__, 8, 7, 6, 5, 4, 3, 2, 1, 0))
+#define _ARG_N(_1, _2, _3, _4, _5, _6, _7, _8, _9, count, ...) count
+
+// Overloading Macro on Number of Arguments
+// http://stackoverflow.com/questions/11761703/overloading-macro-on-number-of-arguments
+#define _VFUNC(NAME, N) CONCAT(NAME, N)
+#define VFUNC(FUNC, ...) CONCAT(_VFUNC(FUNC, NARGS(__VA_ARGS__))(__VA_ARGS__),EMPTY())