Track program workflow in C++

[Nytro]

[h=3]Track program workflow in C++[/h]By Adam Nagy

When debugging a program it can be useful to see what path the code is taking. Maybe a function is called at the wrong part in the code somehow. There are trace macros in C++ that you can use, but you can also create your own that could also provide information about the level of nesting where the function is called by indenting the debug/trace string based on the level. You could use a class to make sure that the indentation reverts to previous value when the function is finished: once the class instance runs out of scope its destructor will be called.

There must be other/better ways of doing this, but this is still better than not having anything to trace the function calls with.

MyTrace.h

#pragma once



#include <stdio.h>



class CMyTrace

{

private:

  static int m_indent;



public:

  CMyTrace(LPCTSTR lpszFormat, ...);

  virtual ~CMyTrace(void);

};



// If you comment this one line out then the

// debug string part won't be compiled into the project

// E.g. you could do that when compiling the release version

#define USE_CMYTRACE

#ifdef USE_CMYTRACE

#define MYTRACE CMyTrace myTrace

#else

#define MYTRACE

#endif

MyTrace.cpp

#include "StdAfx.h"

#include "MyTrace.h"



int CMyTrace::m_indent = 0;



CMyTrace::CMyTrace(LPCTSTR lpszFormat, ...)

{

  TCHAR szBuffer[512];

  _stprintf(szBuffer, _T("%*s"), m_indent * 2, _T(""));

  ::OutputDebugString(szBuffer);



  va_list args;

  va_start(args, lpszFormat);

  int nBuf;

  nBuf = _vsntprintf(szBuffer, 511, lpszFormat, args);

  ::OutputDebugString(szBuffer);

  ::OutputDebugString(_T("\n"));

  va_end(args); 



  m_indent++;

}



CMyTrace::~CMyTrace(void)

{

  m_indent--; 

}

You can call the trace function at the beginning of each of your function.

STDMETHODIMP CMyAddInServer::OnActivate (VARIANT_BOOL FirstTime)

{

  MYTRACE(_T("(%s, %d) %s"), _T(__FILE__), __LINE__, _T(__FUNCTION__));



  // etc...


  return S_OK ;

}

The result in the Output Debug window of Visual Studio would look something like this when debugging the program:

(MyAddInServer.cpp, 34) CMyAddInServer::OnActivate
  (MyCommands.cpp, 9) CMyCommands::CMyCommands
    (MyCommandBase.cpp, 15) CMyCommandBase::CreateButtonDefinitionHandler
      (InteractionEventsBase.cpp, 13) CInteractionEventsBase::CInteractionEventsBase
  (MyCommands.cpp, 41) CMyCommands::CreateMenu
    (MyUtilities.cpp, 78) CMyUtilities::CreateCommandCategory
    (MyUtilities.cpp, 9) CMyUtilities::AddButtonToCommandCategory
      (MyCommandBase.cpp, 107) CMyCommandBase::GetButtonDefinition
    (MyCommands.cpp, 91) CMyCommands::CreateAssemblyRibbonTab
      (MyUtilities.cpp, 115) CMyUtilities::GetRibbon
      (MyUtilities.cpp, 143) CMyUtilities::CreateRibbonTab
      (MyUtilities.cpp, 461) CMyUtilities::AddRibbonTabToEnvironment
        (MyUtilities.cpp, 606) CMyUtilities::GetEnvironment
      (MyUtilities.cpp, 191) CMyUtilities::CreateRibbonPanel
      (MyUtilities.cpp, 238) CMyUtilities::AddButtonToRibbonPanel
        (MyCommandBase.cpp, 107) CMyCommandBase::GetButtonDefinition
        (MyUtilities.cpp, 361) CMyUtilities::FindCommandControl

Sursa: Track program workflow in C++ - Manufacturing DevBlog