Repository Analysis

google/wuffs

Wrangling Untrusted File Formats Safely

4.4 Likely human-written View on GitHub

Analysis Overview

This report presents the forensic synthetic code analysis of google/wuffs, a C project with 4,801 GitHub stars. SynthScan v2.0 examined 156,244 lines of code across 442 source files, recording 649 pattern matches distributed across 6 syntactic categories. The overall adjusted score of 4.4 places this repository in the Likely human-written band.

The scanner applied 160+ deterministic lexical heuristics, multi-line block detectors, abstract syntax tree depth profilers, and a cross-file Jaccard similarity matrix to construct a statistically normalised synthetic code estimate. All matches are individually weighted by severity coefficient and contextual multiplier before summation, and the resulting headline score is temporally discounted to account for the repository's development history relative to the commercial emergence of large language model coding tooling (November 2022 onward).

4.4
Adjusted Score
4.4
Raw Score
100%
Time Factor
2026-08-08
Last Push
4.8K
Stars
C
Language
156.2K
Lines of Code
442
Files
649
Pattern Hits
2026-08-09
Scan Date
0.00
HC Hit Rate

What These Metrics Mean

Adjusted Score
Primary synthetic code indicator. Raw score normalised per 1,000 lines of code and multiplied by the temporal discount factor. This is the definitive comparative metric — use it to rank repositories by AI authorship density.
Raw Score
The unmodified sum of all severity-weighted, context-multiplied pattern match scores before temporal discounting. Reflects the absolute signal strength independent of when the repository was last active.
Time Factor
The temporal discount multiplier (0–100%) applied to the raw score. Repositories last updated before ChatGPT's launch (Nov 2022) receive a 5% factor. Full signal is only assigned to repositories active in the post-adoption era (Jan 2024+).
Pattern Hits
Total count of individual pattern matches across all files and categories. A high hit count with a low score may indicate a very large codebase with isolated AI snippets; a low count with a high score indicates dense, concentrated AI signatures.
HC Hit Rate
High+Critical pattern hits per file, averaged across the repository. This orthogonal signal catches repositories where a few files are densely packed with high-severity AI tells — a strong indicator even when the normalised score appears moderate due to codebase size.
Lines of Code / Files
Total lines and files analysed. The scanner examines 94 file extensions. These denominators are used to normalise the score, enabling fair comparison between repositories of vastly different sizes.

Score History

Longitudinal tracking requires multiple scan runs. Once this repository is re-scanned after new commits land, this chart will visualise how the synthetic code signal evolves over time — enabling you to detect whether AI authorship is growing, stabilising, or being actively corrected by human engineers.

No multi-scan history yet — run the scanner again to build trend data.

Severity Breakdown

Classifies detected patterns by their diagnostic confidence and structural impact. CRITICAL patterns (coefficient 10) represent definitive synthetic signatures — hallucinated imports, explicit LLM attribution metadata — virtually never produced by human authors. HIGH (5) indicates strong structural tells such as cross-file repetition or cross-linguistic idioms. MEDIUM (2) covers recognisable conversational padding and AI-specific vocabulary. LOW (1) captures subtle indicators like tautological comments and generic boilerplate that require density to carry independent signal.

CRITICAL 0HIGH 0MEDIUM 25LOW 624

Directory Score Breakdown

This horizontal bar chart decomposes the repository's raw synthetic code score by top-level directory, allowing you to pinpoint precisely which modules or components carry the highest AI authorship density. Directories with disproportionately high scores relative to their size warrant targeted manual review: concentrated AI signatures often trace back to mass-generated configuration layers, auto-ported test suites, LLM-scaffolded boilerplate classes, or entire subsystems authored under heavy copilot assistance. Use this view to prioritise your human code-review effort.

Pattern Findings

The scanner identified 649 distinct pattern matches across 6 syntactic categories. Each entry below represents a discrete location in the source code where the engine recorded a statistically significant AI authorship indicator. Expand any category row to inspect the individual file paths, line numbers, code snippets, and the lexical context (CODE, COMMENT, or STRING) in which each match was detected.

Reading the findings table: The Severity column indicates the diagnostic confidence level (CRITICAL / HIGH / MEDIUM / LOW). The Context column identifies whether the match occurred inside executable code, an inline comment, or a string literal — comment-context matches receive a ×1.5 weight because LLMs systematically over-annotate. The ⚡ bolt icon marks clustered matches: three or more patterns within a 10-line window, each receiving an additional ×1.5 density multiplier as dense clusters constitute far stronger evidence of synthetic authorship than isolated hits.

Over-Commented Block622 hits · 618 pts
SeverityFileLineSnippetContext
LOWbuild-fuzz.sh1#!/bin/bash -euCOMMENT
LOWbuild-example.sh1#!/bin/bash -euCOMMENT
LOWbuild-all.sh1#!/bin/bash -euCOMMENT
LOWbuild-all.sh21#COMMENT
LOWcmd/wuffs-c/release.go161)COMMENT
LOWcmd/wuffs-c/release.go181#pragma GCC diagnostic ignored "-Wimplicit-fallthrough"COMMENT
LOWcmd/wuffs-c/main.go1// Copyright 2017 The Wuffs Authors.COMMENT
LOWcmd/handsum/main.go1// Copyright 2025 The Wuffs Authors.COMMENT
LOWcmd/wuffs/main.go1// Copyright 2017 The Wuffs Authors.COMMENT
LOWcmd/commonflags/commonflags.go1// Copyright 2017 The Wuffs Authors.COMMENT
LOWcmd/dumbindent/main.go1// Copyright 2020 The Wuffs Authors.COMMENT
LOWcmd/dumbindent/main.go21// Pass -spaces=N or -tabs to use N spaces or 1 tab per indent level. TheCOMMENT
LOWcmd/dumbindent/main.go41// real 0m0.668sCOMMENT
LOWcmd/ractool/gen.go1// Copyright 2019 The Wuffs Authors.COMMENT
LOWcmd/ractool/main.go1// Copyright 2019 The Wuffs Authors.COMMENT
LOWcmd/wuffsfmt/main.go1// Copyright 2017 The Wuffs Authors.COMMENT
LOWtest/3pdata/fetch-pngsuite.sh1#!/bin/bash -euCOMMENT
LOWtest/3pdata/fetch-blinksuite.sh1#!/bin/bash -euCOMMENT
LOWtest/3pdata/fetch-golangsuite.sh1#!/bin/bash -euCOMMENT
LOWtest/3pdata/fetch-tgasuite.sh1#!/bin/bash -euCOMMENT
LOWtest/3pdata/fetch-webpsuite.sh1#!/bin/bash -euCOMMENT
LOWtest/3pdata/fetch-bmpsuite.sh1#!/bin/bash -euCOMMENT
LOWtest/3pdata/fetch-xzsuite.sh1#!/bin/bash -euCOMMENT
LOWtest/3pdata/fetch-xzsuite.sh21# Check out a specific commit (from February 2024).COMMENT
LOWtest/3pdata/fetch-xzsuite.sh41# contains a backdoor:COMMENT
LOWtest/3pdata/fetch-xzsuite.sh61# nigeltao/xz-tests-files at 6e0194063a6dc205d4db35e307778efe1c9f1875 doesCOMMENT
LOWtest/3pdata/fetch-xzsuite.sh81#COMMENT
LOWtest/data/hello.sh1#!/bin/bash -euCOMMENT
LOWtest/data/artificial-thumbhash/make.go1// Copyright 2024 The Wuffs Authors.COMMENT
LOWtest/data/artificial-thumbhash/make.go21// of the original thumbhash description or implementation. But "\xC3\xBE" isCOMMENT
LOW…if/pixel-data-too-much-bad-lzw.gif.make-artificial.txt21# The frame area is 4 pixels and we supply 4 but then an invalid LZW code.COMMENT
LOW…icial-gif/multiple-loop-counts.gif.make-artificial.txt1# Feed this file to script/make-artificial.goCOMMENT
LOW…f/pixel-data-too-much-good-lzw.gif.make-artificial.txt21# The frame area is 4 pixels but we supply 5 (that's still valid LZW data).COMMENT
LOW…a/artificial-gif/metadata-full.gif.make-artificial.txt21# Application Identifier "ICCRGBG1".COMMENT
LOW…ficial-gif/frame-out-of-bounds.gif.make-artificial.txt1# Feed this file to script/make-artificial.goCOMMENT
LOW…ficial-gif/frame-out-of-bounds.gif.make-artificial.txt21# 5. Expand the image width×height to 4×5, so that no frames are clipped. ThisCOMMENT
LOW…ficial-gif/frame-out-of-bounds.gif.make-artificial.txt41# but a surprised user filed https://github.com/golang/go/issues/20856 whenCOMMENT
LOW…l-deflate/distance-code-31.deflate.make-artificial.txt1# Feed this file to script/make-artificial.goCOMMENT
LOW…a/artificial-bzip2/huffman-258.bz2.make-artificial.txt21 bits 16 0xFFFFCOMMENT
LOW…a/artificial-bzip2/huffman-258.bz2.make-artificial.txt61COMMENT
LOWtest/data/artificial-xz-filter/make.go1// Copyright 2024 The Wuffs Authors.COMMENT
LOW…rtificial-jpeg/make-hippopotamus-bad-comment-length.go1// Copyright 2024 The Wuffs Authors.COMMENT
LOW…rtificial-jpeg/make-hippopotamus-bad-comment-length.go21// the itu-t81.pdf spec section B.1.1.4 "Marker segments") but libjpeg-turbo isCOMMENT
LOW…data/artificial-jpeg/make-hippopotamus-sof-dht-swap.go1// Copyright 2024 The Wuffs Authors.COMMENT
LOW…data/artificial-jpeg/make-hippopotamus-sof-dht-swap.go21//COMMENT
LOWtest/c/mimiclib/jpeg.c1// Copyright 2023 The Wuffs Authors.COMMENT
LOWtest/c/mimiclib/webp.c1// Copyright 2024 The Wuffs Authors.COMMENT
LOWtest/c/mimiclib/xxhash.c1// Copyright 2023 The Wuffs Authors.COMMENT
LOWtest/c/mimiclib/lzma.c1// Copyright 2023 The Wuffs Authors.COMMENT
LOWtest/c/mimiclib/deflate-gzip-zlib.c1// Copyright 2017 The Wuffs Authors.COMMENT
LOWtest/c/mimiclib/openssl.c1// Copyright 2023 The Wuffs Authors.COMMENT
LOWtest/c/mimiclib/gif.c1// Copyright 2017 The Wuffs Authors.COMMENT
LOWtest/c/mimiclib/gif.c41COMMENT
LOWtest/c/mimiclib/png.c1// Copyright 2020 The Wuffs Authors.COMMENT
LOWtest/c/mimiclib/png.c21// #define WUFFS_MIMICLIB_USE_STB_IMAGE_INSTEAD_OF_LIBPNG 1COMMENT
LOWtest/c/mimiclib/png.c281 for (size_t i = 0; i < quirks_len; i++) {COMMENT
LOWtest/c/mimiclib/bzip2.c1// Copyright 2022 The Wuffs Authors.COMMENT
LOWtest/c/mimiclib/stb.c1// Copyright 2023 The Wuffs Authors.COMMENT
LOWtest/c/std/json.c41// To use that single file as a "foo.c"-like implementation, instead of aCOMMENT
LOWtest/c/std/json.c3441COMMENT
562 more matches not shown…
Decorative Section Separators18 hits · 54 pts
SeverityFileLineSnippetContext
MEDIUMbuild-fuzz.sh12# ----------------COMMENT
MEDIUMbuild-example.sh12# ----------------COMMENT
MEDIUMbuild-all.sh12# ----------------COMMENT
MEDIUMtest/3pdata/fetch-pngsuite.sh12# ----------------COMMENT
MEDIUMtest/3pdata/fetch-blinksuite.sh12# ----------------COMMENT
MEDIUMtest/3pdata/fetch-golangsuite.sh12# ----------------COMMENT
MEDIUMtest/3pdata/fetch-tgasuite.sh12# ----------------COMMENT
MEDIUMtest/3pdata/fetch-webpsuite.sh12# ----------------COMMENT
MEDIUMtest/3pdata/fetch-bmpsuite.sh12# ----------------COMMENT
MEDIUMtest/3pdata/fetch-xzsuite.sh12# ----------------COMMENT
MEDIUMtest/data/hello.sh12# ----------------COMMENT
MEDIUMhello-wuffs-c/run.sh12# ----------------COMMENT
MEDIUMscript/print-nia-checksums.sh12# ----------------COMMENT
MEDIUMscript/confirm-matches-djpeg.sh12# ----------------COMMENT
MEDIUMscript/bench-history.sh12# ----------------COMMENT
MEDIUMscript/print-mzcat-checksums.sh12# ----------------COMMENT
MEDIUMscript/run-json-test-suite.sh12# ----------------COMMENT
MEDIUMdoc/note/enumerated-media-types.txt2# ----------------------COMMENT
AI Slop Vocabulary5 hits · 15 pts
SeverityFileLineSnippetContext
MEDIUMtest/data/nobel-prizes.json1{"prizes":[{"year":"2019","category":"chemistry","laureates":[{"id":"976","firstname":"John","surname":"Goodenough","motCODE
MEDIUMtest/data/nobel-prizes.json1{"prizes":[{"year":"2019","category":"chemistry","laureates":[{"id":"976","firstname":"John","surname":"Goodenough","motCODE
MEDIUMtest/data/nobel-prizes.json1{"prizes":[{"year":"2019","category":"chemistry","laureates":[{"id":"976","firstname":"John","surname":"Goodenough","motCODE
MEDIUMinternal/cgen/liveness.go50// Essentially, the state transitions are: strong is sticky, weak to strongCOMMENT
MEDIUMinternal/cgen/base/token-public.h93// for 1_DST_1_SRC_COPY) are in the FOO format. Definitely means that the lackCOMMENT
Self-Referential Comments2 hits · 4 pts
SeverityFileLineSnippetContext
MEDIUMcmd/ractool/data.go136 $ # Create a shared dictionary. Using zstd-the-program produces aCODE
MEDIUMcmd/ractool/main.go137 $ # Create a shared dictionary. Using zstd-the-program produces aCODE
Slop Phrases1 hit · 2 pts
SeverityFileLineSnippetContext
LOWhello-wuffs-c/wuffs-parse.c35 // // No need to call wuffs_demo__parser__initialize, but don't forget toCOMMENT
TODO Padding1 hit · 2 pts
SeverityFileLineSnippetContext
LOWinternal/cgen/base/image-public.h500// TODO: implement the other modes.COMMENT