LLVM#

• a conversation with open ai llm: 01 mini

Q: rust (via rustc) zig and c (via clang) hit llvm apis to produce ir, which llvm compiles to machine code. theoretically, any language compiling to llvm ir can link its binary with any other one. llvm should compile not only to machine code but also wasm. it could be one of the modules.

A: it does, but through the compiler interface of each language for instance with rust

Rust in JS Node#

rustup target add wasm32-unknown-unknown

// lib.rs
    #[no_mangle]
    pub extern "C" fn add(a: i32, b: i32) -> i32 {
        a + b
    }

rustc --target=wasm32-unknown-unknown --crate-type=cdylib lib.rs -o libadd.wasm

// index.js
    const fs = require('fs');
    const wasmBuffer = fs.readFileSync('./libadd.wasm');

    WebAssembly.instantiate(wasmBuffer).then(wasmModule => {
        const add = wasmModule.instance.exports.add;
        console.log(add(5, 7)); // Output: 12
    });

node index.js

Rust in C#

• lib.rs

#[no_mangle]
    pub extern "C" fn rust_add(a: i32, b: i32) -> i32 {
        a + b
    }

• lib.c

// lib.c
    int c_multiply(int a, int b) {
        return a * b;
    }

rustc --target=wasm32-unknown-unknown --crate-type=cdylib lib.rs -o librust_add.wasm

clang --target=wasm32-unknown-unknown -c lib.c -o lib.o
        wasm-ld --no-entry --export-all lib.o -o libc_multiply.wasm

Note#

I bet the bytecode alliance has thought through this already