LLVM-EXTRACT(1)

✨ LLVM-EXTRACT(1) ✨

okay so bestie, this is the LLVM-EXTRACT(1) page for llvm-extract, straight from the LLVM manual. It’s literally giving “pull one function out of an LLVM module” main character energy. 💅

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🎀 NAME 🎀

llvm-extract - extract a function from an LLVM module

🌸 SYNOPSIS 🌸

llvm-extract [options] --func function-name [filename]

🦋 DESCRIPTION 🦋

okay so llvm-extract takes the name of a function and extracts it from the LLVM bitcode file you give it. It is primarily used as a debugging tool to reduce test cases from larger programs that are triggering a bug. Literally the cleanup queen for bug repros. 👑

In addition to extracting the bitcode of the specified function, llvm-extract will also remove unreachable global variables, prototypes, and unused types. Slay, no dead weight. ✨

llvm-extract reads its input from standard input if filename is omitted or if filename is -. The output is always written to standard output, unless the -o option is specified (see below). Periodt.

💅 OPTIONS 💅

okay so here’s the full option menu, bestie — every flag, every argument, no skips. 🫶

• --alias alias-name — extract the alias named function-name from the LLVM bitcode. May be specified multiple times to extract multiple alias at once.
• --ralias alias-regular-expr — extract the alias matching alias-regular-expr from the LLVM bitcode. All alias matching the regular expression will be extracted. May be specified multiple times.
• --bb basic-block-specifier — extract basic blocks(s) specified in basic-block-specifier. May be specified multiple times. Each <function:bb[;bb]> specifier pair will create a function. If multiple basic blocks are specified in one pair, the first block in the sequence should dominate the rest.
• --delete — delete specified Globals from Module.
• -f — enable binary output on terminals. Normally, llvm-extract will refuse to write raw bitcode output if the output stream is a terminal. With this option, llvm-extract will write raw bitcode regardless of the output device.
• --func function-name — extract the function named function-name from the LLVM bitcode. May be specified multiple times to extract multiple functions at once.
• --rfunc function-regular-expr — extract the function(s) matching function-regular-expr from the LLVM bitcode. All functions matching the regular expression will be extracted. May be specified multiple times.
• --glob global-name — extract the global variable named global-name from the LLVM bitcode. May be specified multiple times to extract multiple global variables at once.
• --rglob glob-regular-expr — extract the global variable(s) matching global-regular-expr from the LLVM bitcode. All global variables matching the regular expression will be extracted. May be specified multiple times.
• --keep-const-init — preserve the values of constant globals.
• --recursive — recursively extract all called functions.
• -help — print a summary of command line options.
• -o filename — specify the output filename. If filename is - (the default), then llvm-extract sends its output to standard output.
• -S — write output in LLVM intermediate language (instead of bitcode).

💀 EXIT STATUS 💀

If llvm-extract succeeds, it will exit with 0. Otherwise, if an error occurs, it will exit with a non-zero value. Bestie, zero means we ate; non-zero means something went sideways. 😭

🌈 SEE ALSO 🌈

bugpoint(1)

👑 AUTHOR 👑

Maintained by the LLVM Team (https://llvm.org/). They keep the lights on. 🫶

🍓 COPYRIGHT 🍓

2003-2025, LLVM Project

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bye bestie 🫶 — source/version: LLVM 19, date: 2025-01-17. LLVM-EXTRACT(1) out. 💅✨