Question

I built a dynamic lib called InterfaceLayer.so.
When I call:

> nm InterfaceLayer

As output, I get some symbols that look like:

00000e28  T _Z5startv

while I was expecting it to be "start", just as the name of the function I defined in the code.

Why does this happen?

Answer 1

That’s because of C++ name mangling

nm -C

demangles them.

To prevent name mangling,

• use a C compiler (gcc, not g++), name your source file .c (not .cpp)
• or declare extern “C”:

.

my.h

  extern "C" 
  {
        void start();
        void finish();
  }

This will give them “C” linkage, meaning they can’t be overloaded, cannot pass by reference, nothing c++ 🙂