How to link modules and JIT execution by using ruby-llvm

putd.c

#include <stdio.h>

int putd(double x) {
    printf("putd: %.2f\n", x);
    return 1;
}

test.c

#include <stdio.h>

extern int putd(double x);

int main(void) {
    int v = putd(10.5);
    printf("v = %d\n", v);
    return 0;
}

test.rb

require 'llvm/core'
require 'llvm/linker'
require 'llvm/execution_engine'

# Initialize JIT
LLVM.init_jit

# Parse .bc files into modules
putd_mod = LLVM::Module.parse_bitcode(File.expand_path("./putd.bc", File.dirname(__FILE__)))
main_mod = LLVM::Module.parse_bitcode(File.expand_path("./test.bc", File.dirname(__FILE__)))

# Verify and dump
putd_mod.verify!
main_mod.verify!

putd_mod.dump
main_mod.dump

# Linking
putd_mod.link_into_and_destroy(main_mod)

# Execute
engine = LLVM::JITCompiler.new(main_mod)
engine.run_function(main_mod.functions["main"])

engine.dispose