LLVM-EXTRACT(1)

💅 LLVM-EXTRACT — the manual page, bestie edition 💅

okay so this is llvm-extract from the LLVM manual set, and honestly? she's a little diva with one job and she does it flawlessly.

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✨ NAME ✨

llvm-extract — extract a function from an LLVM module

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🌸 SYNOPSIS 🌸

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

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🦋 DESCRIPTION 🦋

So here's the tea, bestie: llvm-extract takes the name of a function and extracts it out of the LLVM bitcode file you point it at. That's it. That's the whole vibe.

Her main character era is being a debugging tool — you use her to shrink a giant program down into a tiny little test case when something is triggering a bug. Think of it like ✨decluttering✨ but for bitcode. 🔥

And she's not just grabbing the function and leaving, no no. She's thorough. On top of extracting the bitcode of the specified function, llvm-extract will also remove unreachable global variables, prototypes, and unused types. She cleans up after herself, periodt. 🧹💅

Where does she read from? If you omit filename, or if filename is -, she reads from standard input. And where does the output go? always to standard output — unless you use the -o option (more on that below, don't worry).

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🎀 OPTIONS 🎀

• --alias alias-name — extract the alias named function-name from the LLVM bitcode. You can pass this multiple times to extract multiple alias at once. (yes, multiple alias. she said what she said.)
• --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. (yes bestie, that's a rule, not a suggestion 👀)
• --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. She's being brave for you. 🙈
• --func function-name — extract the function named function-name from the LLVM bitcode. May be specified multiple times to extract multiple functions at once. (this is the girl the synopsis is talking about, iykyk)
• --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. she goes deeper. 🌀
• -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).

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👑 EXIT STATUS 👑

If llvm-extract succeeds, she exits with 0. Otherwise, if an error occurs, she exits with a non-zero value. Slay when it works, sad girl hours when it doesn't. 😭

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🔥 SEE ALSO 🔥

bugpoint(1)

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💖 AUTHOR 💖

Maintained by the LLVM Team (<https://llvm.org/>). wait, no links allowed — okay, the address is literally just https://llvm.org/ bestie, go look it up. 🫶

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🌈 COPYRIGHT 🌈

2003-2025, LLVM Project

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and that's the whole page!! ✨ this one came from the LLVM manual set, dated 2025-09-03, and it's page 20 of the LLVM-EXTRACT(1) lineup. go forth and extract, bestie, you've got this 💅💖🎀