Link to home
Avatar of SpringMVC

asked on

Problem initializing (extern) array, C++, MFC

I have a problem initializing array..
Program compiles without any errors & warnings, but when it starts ASSERT failure occurs,
because array elements are <bad pointers>.
See some code snippets..
Any help would be highly appreciated!!
In one header, lets call it A.h is defined struct TranslationPair and this header is included in stdafx.h:
struct TranslationPair
	TranslationPair(LPCTSTR sk, LPCTSTR sv) : sKey(sk), sDefVal(sv)
	{ }

	TranslationPair(TranslationPair& tp) : sKey(tp.sKey), sDefVal(tp.sDefVal)
	{ }


	CString sKey;
	CString sDefVal;

Then in stdafx.cpp is defined (and initialized) array arUserPermissionsDescs:
const TranslationPair arUserLevels[SECURITY_MAX_PERMISSIONS] = 
	TranslationPair ( _T("A"), _T("A") ),
              TranslationPair ( _T("B"), _T("B") ),
Now in another file, lets call it B.h:
extern const TranslationPair arUserLevels[SECURITY_LEVELS_NR];
ASSERT occurs in one of the methods of class defined in B.h & B.cpp:
void B::func()
  CString s = _T("AA");
  s == arUserLevels[0].sKey; // ASSERT, aruserLevels[0] - bad pointer, probably, array not initialized.
Some info about application:
1) It's MFC application.
2) Call stack looks like:  __tmainCRTStartup()->....->constructor of CMyApp(which is derived from CWinApp)->constructor of class defined in B(i.e it's called from constructor of CMyApp) -> B::func()
3) That's all, any ideas

Open in new window

Avatar of Zoppo
Flag of Germany image

Hi SpringMVC,

I guess the problem is caused by the fact you try to access the array within your CWinApp-derived classes constructor (i.o.w. when 'theApp' is initialized).

In this case it's not granted that 'arUserLevels' is already initialized since both 'arUserLevels' and 'theApp' are global variables, so it's undefined which one is initialized first.

I think to get this working you should move the code which accesses 'arUserLevels' (so the code from the app's constructor which calls 'B::func') to anywhere else where you know everything global is initialized completeley, i.e. to your CWinApp-derived classes 'InitInstance' method.

Hope that helps,

Avatar of SpringMVC


Thanks for suggestion, probably, you are right.

But in past it was:
TCHAR *arUserLevels[MAX] =
  _T("Admin", _T("User"), _T("SuperUser")
and it worked!!
Now problem is, that class B has no default contructor, and the object of B is in CMyApp..
So if I put initializing of B in InitInstance, I will have to make a default constructor for B, which will break application's logic/structure/or whatever it is..
Any ideas, how can I make refactoring? :)

P.S By the way, sorry for English :)
Avatar of Zoppo
Flag of Germany image

Blurred text
View this solution by signing up for a free trial.
Members can start a 7-Day free trial and enjoy unlimited access to the platform.
See Pricing Options
Start Free Trial
Well, thanks, I'll think a little bit more about how to "workaround" this..