A one-number triage tool for C code (and a cheap feedback loop for LLM output)

A developer released c-score, a single-file, dependency-free Python tool that scores C functions on a single number derived from nesting depth, pointer depth, and dereference chains, and validated it against maintenance churn in libXt and libtiff plus 20+ years of git history for libtiff, curl, redis, and OpenMotif. The developer reports that the same score can be used as a cheap feedback loop to steer LLM-generated C toward flatter output in one rewrite round, while cautioning it is a triage aid rather than a bug detector.

C gets hard to trust in three predictable ways: deep nesting, pointers to pointers, and a- b- c chains where nobody null-checks the middle pointer. So I wrote a tiny scorer that squashes that into one number per function: score f = nesting × pointer depth × deref chain Each factor is one sentence: if / for / while levels int , int , int in params and locals deeper is closer to a memory bug a- b- c runs, i.e. null-derefs where the middle pointer came from somewhere else It's one file, zero dependencies, no parser worth mentioning. I checked it against maintenance churn — how often a function actually gets touched — on two very different codebases libXt, a 40-year-old X11 toolkit, and libtiff, a format parser : I also ran it across 20+ years of git history for libtiff, curl, redis and OpenMotif. None of them trend toward smaller functions — the median stays flat and the biggest function only ever grows . Which is exactly why a cheap pointer to the hot spots helps. LLM-generated C has the same tell. The loop is: generate → c-score file.c → "rewrite the top 3" → re-score One round visibly flattens the output. A dumb, explainable number is enough to steer an LLM — you don't need a real static analyzer for this. It's a triage tool, not a bug detector. It won't find semantic bugs, and it can't see a deep call stack full of side effects. The parser is not perfect, and the Python is LLM-generated too. But the idea is the sound part — before you pick it apart, run it on a real codebase. pip install c-code-score for f in src/ .c; do c-score "$f"; done \ | awk '/^ ^ /{n=$1} /^ score:/{print n,$2}' \ | sort -k2 -rn | head Repo: https://github.com/xtforever/c-score https://github.com/xtforever/c-score · https://codeberg.org/au1064/c-score https://codeberg.org/au1064/c-score