./luac -l a.lua
main <a.lua:0,0> (6 instructions at 0xe55b40)
0+ params, 2 slots, 1 upvalue, 0 locals, 3 constants, 1 function
1[5]CLOSURE 0 0; 0xe55d40
2[2]SETTABUP 0 -1 0; _ENV "foo"
3[6]GETTABUP 0 0 -2; _ENV "foo"
4[6]LOADK 1 -3; 123
5[6]CALL 0 2 1
6[6]RETURN 0 1
function <a.lua:2,5> (7 instructions at 0xe55d40)
1 param, 4 slots, 1 upvalue, 1 local, 3 constants, 0 functions
1[3]GETTABUP 1 0 -1; _ENV "print"
2[3]LOADK 2 -2; "foo"
3[3]MOVE 3 0
4[3]CALL 1 3 1
5[4]LOADK 1 -3; 2
6[4]RETURN 1 2
7[5]RETURN 0 1