multiple destructors - which gets linked in?

[Andy Green]

Not a bug report, but a question. In the class hierarchy below, if I compile to 
intermediate (assembler) files, I can see multiple destructors for base and 
derived, e.g. DerivedD0Ev, DerivedD1Ev, DerivedD2Ev, and multiple instantiations 
of each in different compilation units.

class Base
{
    // a few methods

    virtual ~Base();
};

class Derived : public Base
{
    // a few more methods, some overridden
    // DESTRUCTOR NOT OVERRIDDEN - let compiler generate it
};

class ReallyDerived : public Derived
{
    // again, just use the compiler-generated destructor
};

I need to know which instance of DerivedD2Ev gets linked into the final 
executable (don't ask why...), so I modified the assembler files and continued 
the build. However my modifications (inserted instructions) never make it into 
the final build. If I modify any other function, I see my changes appear in the 
binary, but not these destructors.

Interestingly, there is no instance of it in Derived.S, just in ReallyDerived.S 
and in another file which references it. I guess there must be another 
instantiation of DerivedD2 somewhere, but I can't find it. Can anyone suggest 
what is going on?

[We're using arm-elf-g++ 3.2 and arm-elf-ld version 2.13]