What is time_t ultimately a typedef to?

Question

I searched my Linux box and saw this typedef:

typedef __time_t time_t;

But I could not find the __time_t definition.

Answer 1

[root]# cat time.c

#include 

int main(int argc, char** argv)
{
        time_t test;
        return 0;
}

[root]# gcc -E time.c | grep __time_t

typedef long int __time_t;

It's defined in $INCDIR/bits/types.h through:

# 131 "/usr/include/bits/types.h" 3 4
# 1 "/usr/include/bits/typesizes.h" 1 3 4
# 132 "/usr/include/bits/types.h" 2 3 4