munge.py

#!/usr/bin/env python3

import json
import sys


def find_all(data, typ, val):
    result = []

    def rec(root):
        if root.get("type") == typ and root.get("value") == val:
            result.append(root)
        child = root.get("child")
        if child:
            assert isinstance(child, list), child
            for c in child:
                rec(c)

    rec(data)
    return result


def main():
    with open(sys.argv[1], "r") as f:
        data = json.loads(f.read())

    source_sets = find_all(data, "FUNCTION", "source_set")
    for ss in source_sets:
        # 0 is name of source_set, 1 is body.
        body = ss["child"][1]
        assert body["type"] == "BLOCK"
        block_elems = body["child"]

        # Change `deps = [...]` to `deps += [...]`.
        for be in block_elems:
            if be.get("type") == "BINARY" and be.get("value") == "=":
                lhs = be.get("child")[0]
                if lhs.get("type") == "IDENTIFIER" and lhs.get("value") == "deps":
                    be["value"] = "+="

    with open(sys.argv[2], "w") as f:
        json.dump(data, f)


if __name__ == "__main__":
    main()