warnings: [ /global variable/ ]
----
a = 2;
a += 1;
a -= 1;
a *= 4;
a /= 2;
a %= 0;
a <<= 0;
a ^= 0;
----
a = 2
a += 1
a -= 1
a *= 4
a /= 2
a %= 0
a <<= 0
a ^= 0
