December 7, 2025
Hello, World? Hello, drama
Java Hello World, LLVM Edition
Java says Hello via LLVM — devs clap, groan, and meme
TLDR: A Java demo uses a new native-interop feature to build and run “Hello, World!” through LLVM, proving Java can generate and JIT native code. Comments split between “cool educational hack” and “unnecessary overkill,” with side chatter about obfuscation, a broken link, and a 39-language Hello meme.
Java just said “Hello, World!” in the most extra way possible: by using a new Java feature (the Foreign Function & Memory API, a safer replacement for JNI) to talk to LLVM, the tool behind many compilers, and generate native code. The tutorial is nerd candy, but the comments turned it into a reality TV reunion.
On one side, the tinkerers are thrilled. “This is educational!” cheered one, dropping a practical Go alternative with llir/llvm. Another went full fandom mode for LLVM, praising its endless uses and even name-dropping code obfuscation, which sparked raised eyebrows and whispered “but should we?” energy.
Enter the purists: why not just… write Java? One skeptic demanded, “What’s wrong with the standard JDK?” — basically calling this a Rube Goldberg machine for printing a sentence. And because it’s the internet, someone got a “500 internal server error” and declared the vibes cursed.
For comic relief, a reader flexed a poster of “Hello, World!” in 39 languages, turning the thread into a global greeting contest with big “because we can” energy.
Verdict: It’s a playful proof-of-concept showing Java can break out of its sandbox and play nice with native code. Half the crowd loves the hack. The other half says: fun party trick, but please, not in production.
Key Points
- •The article shows how to use Java’s FFM API to call the LLVM C API, generate LLVM IR, and JIT-compile a “Hello, World!” program.
- •LLVM’s background and IR characteristics are explained, including its SSA nature and three representations (in-memory, bitcode, textual).
- •A minimal LLVM IR example is provided, demonstrating a global string, an external puts declaration, a main function, and execution via lli.
- •Instructions are given to install LLVM (e.g., version 20) on Ubuntu/Debian using the apt.llvm.org llvm.sh script to access shared libraries and headers.
- •The article introduces jextract to generate Java bindings for the LLVM C API and outlines setting up a Maven project with Java >= 22 (example: 25).