Re: Using vector as class member lead to Data Abort error

From:
"Doug Harrison [MVP]" <dsh@mvps.org>
Newsgroups:
microsoft.public.vc.mfc
Date:
Thu, 19 Feb 2009 02:15:02 -0600
Message-ID:
<t15qp4tar7bs7l8pufjdk79obd64j4jq32@4ax.com>
On Wed, 18 Feb 2009 17:34:01 -0800 (PST), "Jason .Y"
<lin.yang.jason@gmail.com> wrote:

Hi, I'm coding on windows mobile 6 and I have meet a strange problem,
which I have already tried to Google it, but still cann't work it out.
here is my problem:

there is a class with a vector as member as below:
code:
/**********MyTest.h****************/
#pragma once
#include <string>
#include <vector>

class CMyTest
{
public:
       CMyTest(void);
public:
       ~CMyTest(void);

private:
       vector<string> m_vecString;

};

/*****************************/

and I also have a dialog class as below,which has CMyTest class
object:
/**************Mobile_Test**************/
// Mobile_TestDlg.h

#pragma once
#include <iostream>
#include <fstream>
#include "InfoDlg.h"
#include "MyTest.h"

#define WM_MSGWHITSTR (WM_USER+193)

class CMobile_TestDlg : public CDialog
{
public:
       CMobile_TestDlg(CWnd* pParent = NULL);

       enum { IDD = IDD_MOBILE_TEST_DIALOG };

       protected:
       virtual void DoDataExchange(CDataExchange* pDX);

protected:
       HICON m_hIcon;

       virtual BOOL OnInitDialog();
#if defined(_DEVICE_RESOLUTION_AWARE) && !defined
(WIN32_PLATFORM_WFSP)
       afx_msg void OnSize(UINT /*nType*/, int /*cx*/, int /*cy*/);
#endif
       DECLARE_MESSAGE_MAP()

       /*================Data====================*/

public:
       BYTE m_sharedDataArray[521];
private:
       CMyTest m_test; //!!!!

public:
       static UINT Reader(LPVOID pParam);
       static UINT Writer(LPVOID pParam);

public:
       afx_msg void OnBnClickedButtonOk();
       LRESULT OnMsgwithStr(WPARAM wParam, LPARAM lParam);
public:
       afx_msg void OnBnClickedButtonTest();

};

/****************************/

this program compiled fine, but when I run it on Debug mode, I get
error as below:

Platform Type : PocketPC
Data Abort: Thread=97b0aa40 Proc=8c3e89e0 'Mobile_Test.exe'
AKY=00400001 PC=00018c38(Mobile_Test.exe+0x00008c38) RA=0001981c
(Mobile_Test.exe+0x0000981c) BVA=2e29f8f9 FSR=00000001
Unhandled exception at 0x00018c38 in Mobile_Test.exe: 0x80000002:
Datatype misalignment.

and this error seems to happen in the constructor of CTest. because
when I run it step by step, it turns out the error is happened at :
/************xutility.h*******************/
__CLR_OR_THIS_CALL _Container_base()
               : _Myfirstiter(0)
               { // construct childless container
               }
/****************************/

I have no idea why this error happened, Any assistance would be
appreciated.


Together, the "Datatype misalignment" exception and these lines suggest
you've set non-default alignment on a global scale using /Zp or #pragma
pack.

public:
       BYTE m_sharedDataArray[521];
private:
       CMyTest m_test; //!!!!


You should never change the alignment on a global scale. Your best bet is
to only ever use #pragma pack around C structs.

--
Doug Harrison
Visual C++ MVP

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