derived method of abstract base class not getting invoked

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From: Charlie (cs_hart_at_yahoo.com)
Date: 08/31/04

  • Next message: Jochen Kalmbach: "Re: Virtual Address Space" 
    Date: 31 Aug 2004 12:02:19 -0700

    I have the following

    Class Base {
      Base();

       virtual bool func(ListClass* tlist) =0;
    };

    Class Derived:public Base {
      Derived();
      ~ Derived();
      bool func(ListClass* tlist);
    }

    Code to invoke:
    ..
    Derived* ptr = new Derived();
    ptr->func(tlist);

    When I try to step into this function with the debugger I get a popup
    saying there is no source code available. If I look at the following
    code with disassembly window I see code like this:
            ptr->func(tlist);
    000002b4 mov eax,dword ptr [ebp-2Ch]
    000002b7 mov eax,dword ptr [eax]
    000002b9 mov esi,dword ptr [eax]
    000002bb mov edx,dword ptr [ebp-30h]
    000002be mov ecx,dword ptr [ebp-2Ch]
    000002c1 mov eax,esi
    000002c3 push 15B088h
    000002c8 call F9AF9FC0 <<<---- should be calling func but
    does not
    000002cd nop

    But for other methods, the source always has a load of a doubleword
    pointer as I would expect it would be looking up the method in a
    vector table.
            rList->otherFunc(tlist);
    000002f6 mov edx,dword ptr [ebp-30h]
    000002f9 mov ecx,dword ptr [ebp-34h]
    000002fc call dword ptr ds:[00836BB4h] <<< ----- calling
    otherFunc
    00000302 nop works fine

    Since this is debug compiled code I assume the compiler is responsible
    somehow. What I don't know is if there any options I'm using that
    might be causing this.
    I'm using .NET 2003 with the project defined as a console app.

    I should add that I had the same problem with the base destructor,
    even when I had it defined virtual. The derived class destructor was
    not getting invoked.
    I eliminated the destructor in the base .h file and the derived
    destructor started getting invoked at delete.

  • Next message: Jochen Kalmbach: "Re: Virtual Address Space"

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