intermediate representation. attempting to analyze zig code directly would be too hard (especially with comptime). on the way to the compiler backend, the compiler builds a simplified representation that only has "actually existing functions" and is very straightforward, e.g.

    function 10112:
    0: argument 0
    1: argument 1
    2: argument 2
    3: add 0, 1
    4: store 2
    5: call function 1342, (2, 4)
    6: return 5

you can see how building a data dependency graph from this would be easy.