Tests/RunCMake/ObjectLibrary/b.c

#if defined(_WIN32) && defined(COMPILE_FOR_SHARED_LIB)
#  define EXPORT __declspec(dllexport)
#else
#  define EXPORT
#endif

extern int a(void);
EXPORT int b(void)
{
  return a();
}
#ifndef REQUIRED
#  error "REQUIRED needs to be defined"
#endif