Consider this C++ example (I've annotated each class decl with the
unit size of each structure):
struct A { virtual ~A(); }; // 4
struct B { virtual ~B(); }; // 4
struct X : virtual public A,
virtual public B { // 8
};
struct Y : virtual public B { // 4
virtual ~Y();
};
struct Z : virtual public X, public Y { // 8
Z();
};
Z::Z() {}
In this example, the DECL_SIZE_UNIT of "Z" is 8 bytes. Here, the
FIELD_DECL corresponding to it's Y superclass has an offset of 0
bytes and size 4 bytes.
Confusingly (to me at least), the FIELD_DECL for the X superclass has
an offset of 4 bytes and and a size of 8 bytes, which means that the
end of the object is 12 bytes, despite the fact that Z has a
DECL_SIZE_UNIT of 8 bytes.
Is this the intended layout of this structure? What does it mean
when a field runs off the end of the structure? In this case, should
I just ignore the type size and assume that the 8 bytes are
dynamically there?
Thanks,
-Chris
