LLVM-EXTRACT(1)

💅 llvm-extract — extract a function from an LLVM module 👑

okay so this is the man page for llvm-extract, bestie, and it lives in the LLVM manual family. let me walk you through it 🫶

---

🌸 SYNOPSIS 🌸

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

that's the whole vibe. options, then –func plus a function name, then optionally a filename. iconic ✨

---

🦋 DESCRIPTION 🦋

so llvm-extract takes the name of a function and pulls it out of the LLVM bitcode file you point it at. it's primarily a debugging tool — think of it as a little scalpel for shrinking test cases out of bigger programs that are triggering a bug. literally so useful ngl 🔪💀

and it doesn't just carve out the bitcode of the function you named — it also removes unreachable global variables, prototypes, and unused types. cleanup era ✨🧹

also important: llvm-extract reads its input from standard input if filename is omitted, or if filename is -. and the output always goes to standard output, unless you use the -o option (peep below 👀).

---

🎀 OPTIONS 🎀

• –alias alias-name — extracts the alias named function-name from the LLVM bitcode. yes, the page really says function-name there, don't come for me 💀 it may be specified multiple times to extract multiple alias at once. slay 💅
• –ralias alias-regular-expr — extracts the alias matching alias-regular-expr from the LLVM bitcode. every alias matching the regular expression gets extracted. may be specified multiple times. regex girlies rise 🌈
• –bb basic-block-specifier — extracts basic block(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 — that's a real constraint, don't ignore it bestie 😭
• –delete — delete specified Globals from Module. simple as that 🗑️
• -f — enable binary output on terminals. normally llvm-extract refuses to write raw bitcode output if the output stream is a terminal, but with this option it'll write raw bitcode regardless of the output device. it's giving "I know what I'm doing" energy 🔥
• –func function-name — extracts the function named function-name from the LLVM bitcode. may be specified multiple times to extract multiple functions at once. the main character option, honestly 👑
• –rfunc function-regular-expr — extracts 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. batch extraction, we love to see it 💖
• –glob global-name — extracts 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 — extracts 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. no cap, this one keeps your constants intact 🎀
• –recursive — recursively extract all called functions. it goes deep, bestie 🌀
• -help — print a summary of command line options. when in doubt 🫶
• -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). human-readable, we stan 👀✨

⚠️ friendly reminder that -f is the one that overrides the terminal safety check for raw bitcode output — the default behavior is to refuse, so only flex it when you mean it 💅

---

💀 EXIT STATUS 💀

if llvm-extract succeeds, it exits with 0. otherwise, if an error occurs, it exits with a non-zero value. that's it, that's the check 🫡

---

🔗 SEE ALSO 🔗

• bugpoint(1)

---

🌟 AUTHOR 🌟

maintained by the LLVM Team (https://llvm.org/). absolute legends 🫶👑

---

📜 COPYRIGHT 📜

2003-2023, LLVM Project

---

okay that's the whole page bestie, you're officially an llvm-extract expert now 💜 mwah 💋 — page 15, dated 2023-07-14, from the LLVM manual, for LLVM-EXTRACT(1). go forth and shrink those test cases 🦋✨