CRANGLER(1)

💅 CRANGLER(1) — the crangler manual, bestie edition ✨

okay so. crangler. say it with me. it's a User Commands page, it lives in section 1, and it's literally about transforming C source. let's get into it 🫶

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✨ NAME ✨

crangler — C source transformation. that's it, that's the whole vibe 💖

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🌸 SYNOPSIS 🌸

crangler [-?] [-h] [--help]

crangler file.json

two whole moods: ask for help, or hand it a JSON file and let it cook 👑

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🦋 DESCRIPTION 🦋

so crangler is a command-line utility, right? and what it does is it takes a preprocessed C file and makes changes to it — and those changes are prescribed in a JSON configuration file. you tell it what to do in JSON, it does the thing. no cap ✨

the supported transformations are:

• Add a contract (pre / post / assigns) to a named C function. 🎀
• Add a loop contract to a loop identified by the name of the function containing the loop and a loop number. 🔁
• Remove the static storage classifier from a function or a variable. bye bestie 👋
• Replace a function call by a call to a stub. glow-up fr fr 💅

and the resulting source file? it gets written to standard output, or to a file specified in the JSON configuration. your call, main character 🌈

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🔥 EXAMPLE 🔥

okay this is the fun part. the following JSON configuration file makes crangler preprocess remove_static1.c. while processing this file to produce a preprocessed result, no non-standard include paths or defines are required (yes, "reqired" — we don't gatekeep typos here, the original said it, we say it 🥰).

the transformations configured here are:

• removing the static storage classifier from all functions matching the regular expression foobar[12]
• replacing calls to bar by calls to a function called bar_stub

no objects are listed that require transformation. and the result is written to standard output. iconic. periodt.

{
  "sources": [
    "remove_static1.c"
  ],
  "includes": [],
  "defines": [],
  "functions": [
    {
      "foobar[12]": [
        "remove static"
      ],
      "bar": [
        "stub bar_stub"
      ]
    }
  ],
  "objects": [],
  "output": "stdout"
}

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🌱 ENVIRONMENT 🌱

• TMPDIR — all tools honor this environment variable when generating temporary files and directories. yes girl, you can move your temp files wherever you want, she'll respect it 💜

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💀 BUGS 💀

if you encounter a problem — and bestie, sometimes you will 😭 — please create an issue at:

https://github.com/diffblue/cbmc/issues

they will literally help you. go go go 🫶

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👑 COPYRIGHT 👑

2021, Daniel Kroening

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and that's the whole page!! slay ✨

this was crangler-5.59.0, dated June 2022 — thanks for reading my little manual moment, ily, go transform some C 💖🎀🦋