llama's Introduction

llama

A friendly LLVM library for Rust.

Goals:

Support the latest llvm-sys release
Provide an improved interface, while still remaining as close as possible to the LLVM C API.

Due to the size of the LLVM API there is bound to be missing, broken or incomplete functionality in llama, please create an issue if something you need isn't implemented.

NOTE: llama will let you generate invalid IR, take a look at inkwell for LLVM bindings with a focus on type-safety

Documentation

Examples

Inkwell's example using llama:

use llama::*;

// Convenience type alias for the `sum` function.
//
// Calling this is innately `unsafe` because there's no guarantee it doesn't
// do `unsafe` operations internally.
type SumFunc = unsafe extern "C" fn(u64, u64, u64) -> u64;


// Context should be last to perform cleanup in the correct order
struct CodeGen<'ctx> {
    engine: ExecutionEngine<'ctx>,
    build: Builder<'ctx>,
    context: Context<'ctx>,
}

impl<'ctx> CodeGen<'ctx> {
    fn jit_compile_sum(&mut self) -> Result<SumFunc, Error> {
        let i64 = Type::i64(&self.context)?;
        let sum_t = FuncType::new(i64, [i64, i64, i64])?;
        self.engine
            .module()
            .declare_function(&self.build, "sum", sum_t, |f| {
                let params = f.params();
                let x = params[0];
                let y = params[1];
                let z = params[2];

                let sum = self.build.add(x, y, "sum")?;
                let sum = self.build.add(sum, z, "sum")?;
                self.build.ret(sum)
            })?;

        unsafe { self.engine.function("sum") }
    }
}

fn main() -> Result<(), Error> {
    let context = Context::new()?;
    let module = Module::new(&context, "sum")?;
    let build = Builder::new(&context)?;
    let engine = ExecutionEngine::new_jit(module, 0)?;
    let mut codegen = CodeGen {
        context: context,
        build,
        engine,
    };

    let sum = codegen.jit_compile_sum()?;

    let x = 1u64;
    let y = 2u64;
    let z = 3u64;

    unsafe {
        println!("{} + {} + {} = {}", x, y, z, sum(x, y, z));
        assert_eq!(sum(x, y, z), x + y + z);
    }

    Ok(())
}

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