Thread: Destructor called after exception?

Hi,

I'd like to determine, whether the destructor of an object was called during stack unwinding, after an exception was caught, or just the objects lifetime ended normally.

std::uncaught_exception() would be the standard solution, unfortunately it does not work (always returns false) in VC6 (SP5).

Below the contents of uncaught.cpp:

Code:

#include <exception>
_STD_BEGIN

_CRTIMP2 bool __cdecl uncaught_exception()
	{	// report if handling a throw
	return (false);
	}

_STD_END

Funny stuff

Any alternatives, ideas?

Thanks in advance!

Personally, if I wanted to see if a destrutor was called, I'd put a call to OutputDebugString in the destructor code and run the prog through VC++ (or any other windows based) debugger

Originally posted by Fordy
Personally, if I wanted to see if a destrutor was called

This is not my intention.
Maybe I wasn't clear enough, sorry : I wrote a class (CallStack) which traces the call stack.

I need to know whether ~CallStack is called due to an exception, if so, output the callstack to the log file / stdout:

Code:

CallStack::~CallStack()
{	
	/*if( uncaught_exception() )
	{
		Dump();		
	}*/

	if( !myStackList.empty() ) 
	{
		myStackList.pop_back();
	}
	myStackDepth--;
}

I had to comment out those lines, as they are useless (see my thread starter).

Now let me explain the problem.
The CallStack object is instanciated through a macro in each function.

My problem is that I *have* to insert in the source in every catch block the call to dump() (though the DUMP macro ), which is ugly...

Code:

void donuts()
{	
	TRACE_FN(donuts); // instanciate CallStack object
	try
	{
		const int a = 0;		
		int i = i/a; // division by zero - exception is thrown 
	}
	catch(...)
	{
		DUMP; // dumping the CallStack
		cout << "Exception caught!" << "\r\n";
		cout.flush();
		return;
	}
}

Oh right - http://msdn.microsoft.com/library/de...rdbehavior.asp

Looks like it is still an issue with the most recent versions!

I guess you could look at the asm produced by VC++'s try/catch declarations and see if you can figure out a way to ascertain if an exception is being processed....might be lucky, might not - even then you would most likely be tied into that compiler

Originally posted by Fordy
Oh right - http://msdn.microsoft.com/library/de...rdbehavior.asp

Looks like it is still an issue with the most recent versions!

Yes, it's a compiler problem. I've read somewhere that VC7 implements uncaught_exception() as required:
(http://msdn.microsoft.com/library/de...texception.asp

However, my code won't work under VC6 or prior versions.

Therefore I have to keep my DUMP macro in every catch block, which is ugly, but at least it works...

I tried to figure out other alternatives, no solution so far.