wasmer/src/linkers/emscripten/mod.rs

use crate::webassembly::{ImportObject, ImportValue};

mod printf;
mod putchar;

pub fn generate_emscripten_env<'a, 'b>() -> ImportObject<&'a str, &'b str> {
    let mut import_object = ImportObject::new();
    import_object.set("env", "printf", ImportValue::Func(printf::printf as *const u8));
    import_object.set("env", "putchar", ImportValue::Func(putchar::putchar as *const u8));
    import_object
}

#[cfg(test)]
mod tests {
    use super::generate_emscripten_env;
    use crate::webassembly::{instantiate, Export, Instance};

    #[test]
    fn test_putchar() {
        let wasm_bytes = include_wast2wasm_bytes!("tests/putchar.wast");
        let import_object = generate_emscripten_env();
        let result_object = instantiate(wasm_bytes, import_object).expect("Not compiled properly");
        let func_index = match result_object.module.info.exports.get("main") {
            Some(&Export::Function(index)) => index,
            _ => panic!("Function not found"),
        };
        let main: fn(&Instance) = get_instance_function!(result_object.instance, func_index);
        main(&result_object.instance);
    }

    #[test]
    fn test_print() {
        let wasm_bytes = include_wast2wasm_bytes!("tests/printf.wast");
        let import_object = generate_emscripten_env();
        let result_object = instantiate(wasm_bytes, import_object).expect("Not compiled properly");
        let func_index = match result_object.module.info.exports.get("main") {
            Some(&Export::Function(index)) => index,
            _ => panic!("Function not found"),
        };
        let main: fn(&Instance) = get_instance_function!(result_object.instance, func_index);
        main(&result_object.instance);
    }
}