A question about INTERNAL_LINUX_C_LIB.

[George Ma]

Hi, everyone!

Look at such codes in Linux,

--------
#ifdef INTERNAL_LINUX_C_LIB
#define HAVE_MREMAP 1
#else
#define HAVE_MREMAP 0
#endif
--------

I tried on my machine that INTERNAL_LINUX_C_LIB is not
defined. My question is:

1. When the variable is defined? Need I to install some
packages to let the variable defined?

2. What does the variable stand for? what is it function?

Cheers,
George