C / C++ / MFC

Dhiraj kumar Saini wrote:

Please tell me how you have used circular buffer.

// hWnd is the handle of dialog.
::SendMessage( hWnd, WM_COMMAND, IDCANCEL, 0 );

#include <stdarg.h>

inline
char* DTSafeStrCopyLen(LPSTR pDst, LPCSTR pSrc, int len)
{
	if (pDst)
	{
		if (pSrc && len > 0)
		{
			while (len && *pSrc)
			{
				*pDst++ = *pSrc++;
				len--;
			}
		}
		*pDst = 0;
	}
	return pDst;
}

inline
int DTSafeStrCopyLen2(LPSTR pDst, LPCSTR pSrc, int len)
{
	return DTSafeStrCopyLen(pDst, pSrc, len) - pDst;
}

#pragma warning(disable:4702) // unreachable code

int DTSafeFormatStringV(LPSTR pBuffer, int bufferLen, LPCSTR pFormat, va_list args)
{
	if (!pBuffer || bufferLen <= 0)
		return -1;

	int returnLen = 0;

	if (pFormat && *pFormat)
	{
#if _MSC_VER >= 8
		__try
#else
		try
#endif
		{
			returnLen = _vsnprintf(pBuffer, bufferLen, pFormat, args);
			if (returnLen < 0)
			{
				pBuffer[bufferLen - 1] = 0;
				returnLen = bufferLen - 1;
			}
		}
#if _MSC_VER >= 8
		__except (EXCEPTION_EXECUTE_HANDLER)
#else
		catch (...)
#endif
		{
			returnLen = DTSafeStrCopyLen2(pBuffer, "!exception thrown during formatting: \"", bufferLen);
			returnLen += DTSafeStrCopyLen2(&pBuffer[returnLen], pFormat, bufferLen - returnLen); 

			if (returnLen < bufferLen - 1)
			{
				pBuffer[returnLen++] = '"';
				pBuffer[returnLen] = 0;
			}
		}
	}
	else
	{
		pBuffer[0] = 0;
	}

	return returnLen;
}

int DTSafeFormatString(LPSTR pBuffer, int bufferLen, LPCSTR pFormat, ...)
{
	if (!pBuffer || bufferLen <= 0)
		return -1;

	int returnLen = 0;

	if (pFormat && *pFormat)
	{
		va_list args;
		va_start (args, pFormat);
		returnLen = DTSafeFormatStringV(pBuffer, bufferLen, pFormat, args);
		va_end (args);
	}
	else
	{
		pBuffer[0] = 0;
	}

	return returnLen;
}

fantasy1215 wrote:

The compiler don't complain in the compile phase, but when you press F5 to debug, 'unhandle exception' prompt. while not debug, run it at once, you just get wield strings or output.

We all use some sort of printf or CString::Format in the code, we are not careful sometimes. So how to handle this problem or check out the bugs in the exist project?

fantasy1215 wrote:

We all use some sort of printf or CString::Format in the code, we are not careful sometimes. So how to handle this problem