Why warning are coming with Visual Studio 2022 (17.2.6) version?

Nitin Jain 21

Hi,

We have been compiling code with Visual Studio 2022 (17.1.3) version and not seeing any warnings.
But when we updated Visual Studio to latest available version that is Visual Studio 2022 (17.2.6) - we see a lot of warnings.

Can you please explain why these warnings are coming up now, and why they were not coming with previous version.
Also if there is a roadmap to suppress these warnings in coming Visual Studio updates.

Below are few examples of warnings which have started coming with new version (17.2.6) and were not seen with older version (17.1.3)
Please do let me know if you need any more details.

warning C4191: 'type cast': unsafe conversion from 'FARPROC' to 'LPFNBCT'
warning C4242: '=': conversion from '__int64' to 'int', possible loss of data
warning C4311: 'type cast': pointer truncation from 'HANDLE *' to 'DWORD'
warning C4057: 'function': 'LPDWORD' differs in indirection to slightly different base types from 'unsigned int *'
warning C4312: 'type cast': conversion from 'DWORD' to 'HANDLE *' of greater size

-thanks,
Nitin Jain

Viorel 116.6K Reputation points

2022-08-02T13:05:14.237+00:00

If you are also interested in fixing these potential issues (and maybe improving the quality of the code), you can show the problematic lines that generate these reasonable warnings.
Nitin Jain 21 Reputation points

2022-08-02T14:14:30.84+00:00
warning C4191: ‘type cast’: unsafe conversion from ‘FARPROC’ to ‘LPFNBCT’

LPFNBCT BULK_COPY = NULL;
BULK_COPY = (LPFNBCT) GetProcAddress(hLib, TCRUNHREQUESTSFUNC);

warning C4242: ‘=’: conversion from ‘__int64’ to ‘int’, possible loss of data

JCHAR *lpFromRole = NULL;
JCHAR *pRolesApplyingToUser = NULL;
int iOffset = 0;

iOffset = lpFromRole - pRolesApplyingToUser;

warning C4311: ‘type cast’: pointer truncation from ‘HANDLE ’ to ‘DWORD’

EnumWindows( (WNDENUMPROC)EnumWindowsProc, (DWORD)&hPrevWnd);

warning C4057: ‘function’: ‘LPDWORD’ differs in indirection to slightly different base types from ‘unsigned int ’

LPFN2        lpQueryRegValueFunc = NULL;

if(lpQueryRegValueFunc(hkResult,_J("CurrentRelease"),NULL,NULL,RegBuffer, &nRegBufferSize)==ERROR_SUCCESS)

warning C4312: ‘type cast’: conversion from ‘DWORD’ to ‘HANDLE *’ of greater size

BOOL CALLBACK EnumWindowsProc(HWND hwnd, DWORD lParam)
{
  JCHAR buf[1000];

  if (IsWindowVisible(hwnd))
  {
   if (GetWindowText( hwnd, buf, 1000 ))
   {
     if (Strncmp(buf, _J("BusBuild"), 8) == 0)
     {
      *(HANDLE *)lParam = hwnd;
      return FALSE;
     }
   }
  }
  return TRUE;
}
Tianyu Sun-MSFT 30,336 Reputation points Microsoft Vendor

2022-08-03T10:10:38.467+00:00

Hi @Nitin Jain ,

Welcome to Microsoft Q&A forum. I am just thinking, maybe the Warning level has been changed? (C++ project property page > Configuration Properties > C/C++ > General > Warning Level)(C# project property page > Build > Errors and warnings > Warning level)
Nitin Jain 21 Reputation points

2022-08-03T10:16:26.543+00:00

HI @Tianyu Sun-MSFT ,

Thanks for reply. But I am referring microsoft link which says below warnings are anyway turned off by default. So may be they are turned on now and hence causing these issues. Would it be possible to check if there are any issues with the new version release of VS 2022.

warning C4191: 'type cast': unsafe conversion from 'FARPROC' to 'LPFNBCT'
warning C4242: '=': conversion from '__int64' to 'int', possible loss of data

https://learn.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warning-level-3-c4191?view=msvc-170
https://learn.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warning-level-4-c4242?view=msvc-170

-thanks,
Nitin Jain
Nitin Jain 21 Reputation points

2022-08-10T04:50:27.283+00:00

HI @Tianyu Sun-MSFT ,

did u get any update on this?

-thanks,
Nitin Jain
Tianyu Sun-MSFT 30,336 Reputation points Microsoft Vendor

2022-08-11T09:23:32.45+00:00

Hi @Nitin Jain ,

Yes, these days, newer version of Visual Studio 2022 has been released. Could you try to update and check/confirm if this issue appears in the latest version of VS 2022?

If the same issue appears again, please raise a ticket on our Developer Community for further investigate.

Best Regards,
Tianyu
Tianyu Sun-MSFT 30,336 Reputation points Microsoft Vendor

2022-09-06T12:51:04.19+00:00

Hi @Nitin Jain ,

May I know if this issue disappeared in the latest version of VS 2022? If you raised a ticket on Developer Community, could you also share the related thread link here for us to track this issue?

Feel free to contact us.

Regards,
Tianyu

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Why warning are coming with Visual Studio 2022 (17.2.6) version?

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