Resolve preprocessor directives and save output

Question

I have single code base written in C# covering slightly varying requirements from two customers.

namespace Demo
{
    public class DemoClass
    {
#if CUSTOMER_A
        public void CustomerA()
        {
            // customer A logic    
        }
#endif

#if CUSTOMER_B
        public void CustomerB()
        {
            // customer B logic
        }
#endif
    }
}

I need to provide customer A with the source code that only contains his use case.

namespace Demo
{
    public class DemoClass
    {
        public void CustomerA()
        {
            // customer A logic    
        }
    }
}

Is there an out of the box solution for such task?

Answer 1

One solution would be to use CPP, however this solution fails if there are #region #endregion directives.

cpp -C -P -DCUSTOMER_A DemoClass.cs DemoClass_CustomerA.cs