1  #include <features.h>
       2  #if defined(__UCLIBC__)
       3  LIBC=uclibc
       4  #elif defined(__dietlibc__)
       5  LIBC=dietlibc
       6  #elif defined(__GLIBC__)
       7  LIBC=gnu
       8  #else
       9  #include <stdarg.h>
      10  /* First heuristic to detect musl libc.  */
      11  #ifdef __DEFINED_va_list
      12  LIBC=musl
      13  #else
      14  LIBC=gnu
      15  #endif
      16  #endif