Q: GCC linker error when building for iPhone Undefined symbols:
"vtable for NameSpaceA::NameSpaceB::ClassA", referenced from:
__ZTVN4NameSpaceA17NameSpaceB15ClassAE$non_lazy_ptr in libSomeLib.a(SomeLib.bulk.o)
(maybe you meant: __ZTVN4NameSpaceA17NameSpaceB15ClassAE$non_lazy_ptr)

for some classes that are build in this lib. Same code compiles and links fine on Windows. Other classes from same lib are linked fine on Mac too. I don't have any build errors, only linker errors. Can you tell me some reasons for this kind of errors? I think that all virtual functions are implemented because it compiles and links fine on other platforms(not only Windows).

A: In order for gcc to emit the vtables, each of your (polymorphic) classes needs to have at least one virtual, non-inline method. For example if your virtual destructor is inline currently, un-inline it and move it to the source file and that should fix it up.
