Question

In MFC C++ (Visual Studio 6) I am used to using the TRACE macro for debugging. Is there an equivalent statement for plain win32?

Answer 1

_RPTn works great, though not quite as convenient. Here is some code that recreates the MFC TRACE statement as a function allowing variable number of arguments. Also adds TraceEx macro which prepends source file and line number so you can click back to the location of the statement.

Update: The original code on CodeGuru wouldn’t compile for me in Release mode so I changed the way that TRACE statements are removed for Release mode. Here is my full source that I put into Trace.h. Thanks to Thomas Rizos for the original:

// TRACE macro for win32 #ifndef __TRACE_H__850CE873 #define __TRACE_H__850CE873  #include <crtdbg.h> #include <stdarg.h> #include <stdio.h> #include <string.h>  #ifdef _DEBUG #define TRACEMAXSTRING  1024  char szBuffer[TRACEMAXSTRING]; inline void TRACE(const char* format,...) {     va_list args;     va_start(args,format);     int nBuf;     nBuf = _vsnprintf(szBuffer,                    TRACEMAXSTRING,                    format,                    args);     va_end(args);      _RPT0(_CRT_WARN,szBuffer); } #define TRACEF _snprintf(szBuffer,TRACEMAXSTRING,'%s(%d): ', \                 &strrchr(__FILE__,'\\')[1],__LINE__); \                 _RPT0(_CRT_WARN,szBuffer); \                 TRACE #else // Remove for release mode #define TRACE  ((void)0) #define TRACEF ((void)0) #endif  #endif // __TRACE_H__850CE873