It's not modifying the generator. The generator may be a proprietary black box. It's wrapping the generator in a bash script that pipes the result through AWK, etc.
As other commenters have noted, if the awk script is just a pure function of the output of the black-box generator to a new output, then I would consider this a modification to the generator, and no problemo.
However, if your awk script requires the current state of the generated code as input in addition to the output of the black-box generator, and tries to reconcile a diff between the two things, then yep, I consider that busted.
Sure, that's orthogonal. If you wrap the generator in your build system and still always regenerate, it's effectively the same. And also, I think, not what GP was talking about
Pedantic. There's a world of difference between grokking a new code generation DSL+codebase and a shell one-liner that fixes a string that is obviously invalid.
Since the issue is the maintenance of such systems, it is absolutely relevant.
