How can a compiler differentiate between static data members having same name in different classes in C++?

Question

I had a C++ interview recently where I was asked, how does the compiler differentiate static data members having the same name in two different classes?

Since all static data variables are stored in the data segment, there has to be a way by which the compiler keeps track of which static data belongs to which class especially when they have the same name.

Edit: I answered name mangling, but he refused saying name mangling is used only among the members of the same class.

Answer 1

The names are mangled with their class name in them. An example with the clang compiler

class A {
  static int i;
};

int A::i = 0;

Output

$ clang++ -cc1 -emit-llvm main1.cpp -o -
; ModuleID = 'main1.cpp'
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32"
target triple = "i386-pc-linux-gnu"

@_ZN1A1iE = global i32 0, align 4

Where _ZN1A1iE is

$ c++filt _ZN1A1iE
A::i

Answer 2

It's implementation-defined, so there's no one way it has to be done.

Name mangling is commonly used though.