denoland-deno/src/main.rs

extern crate libc;
#[macro_use]
extern crate log;

use libc::c_int;
use std::ffi::CStr;
use std::ffi::CString;
use std::ptr;

mod binding;
use binding::{
    deno_delete, deno_execute, deno_handle_msg_from_js, deno_init,
    deno_last_exception, deno_new, deno_set_flags, DenoC,
};

// Pass the command line arguments to v8.
// Returns a vector of command line arguments that v8 did not understand.
fn set_flags() -> Vec<String> {
    // deno_set_flags(int* argc, char** argv) mutates argc and argv to remove
    // flags that v8 understands.
    // Convert command line arguments to a vector of C strings.
    let mut argv = std::env::args()
        .map(|arg| CString::new(arg).unwrap().into_bytes_with_nul())
        .collect::<Vec<_>>();
    // Make a new array, that can be modified by V8::SetFlagsFromCommandLine(),
    // containing mutable raw pointers to the individual command line args.
    let mut c_argv = argv.iter_mut()
        .map(|arg| arg.as_mut_ptr() as *mut i8)
        .collect::<Vec<_>>();
    // Store the length of the argv array in a local variable. We'll pass a
    // pointer to this local variable to deno_set_flags(), which then
    // updates its value.
    let mut c_argc = argv.len() as c_int;
    // Let v8 parse the arguments it recognizes and remove them from c_argv.
    unsafe {
        deno_set_flags(&mut c_argc, c_argv.as_mut_ptr());
    };
    // If c_argc was updated we have to change the length of c_argv to match.
    c_argv.truncate(c_argc as usize);
    // Copy the modified arguments list into a proper rust vec and return it.
    c_argv
        .iter()
        .map(|ptr| unsafe {
            let cstr = CStr::from_ptr(*ptr as *const i8);
            let slice = cstr.to_str().unwrap();
            slice.to_string()
        })
        .collect::<Vec<_>>()
}

type DenoException<'a> = &'a str;

struct Deno {
    ptr: *const DenoC,
}

impl Deno {
    fn new() -> Deno {
        let ptr = unsafe { deno_new(ptr::null(), deno_handle_msg_from_js) };
        Deno { ptr: ptr }
    }

    fn execute(
        &mut self,
        js_filename: &str,
        js_source: &str,
    ) -> Result<(), DenoException> {
        let filename = CString::new(js_filename).unwrap();
        let source = CString::new(js_source).unwrap();
        let r = unsafe {
            deno_execute(self.ptr, filename.as_ptr(), source.as_ptr())
        };
        if r == 0 {
            let ptr = unsafe { deno_last_exception(self.ptr) };
            let cstr = unsafe { CStr::from_ptr(ptr) };
            return Err(cstr.to_str().unwrap());
        }
        Ok(())
    }
}

impl Drop for Deno {
    fn drop(&mut self) {
        unsafe { deno_delete(self.ptr) }
    }
}

fn main() {
    log::set_max_level(log::LevelFilter::Debug);

    unsafe { deno_init() };

    set_flags();

    /*
    let v = unsafe { deno_v8_version() };
    let c_str = unsafe { CStr::from_ptr(v) };
    let version = c_str.to_str().unwrap();
    println!("version: {}", version);
    */

    let mut d = Deno::new();

    d.execute("deno_main.js", "denoMain();")
        .unwrap_or_else(|err| {
            error!("{}", err);
            std::process::exit(1);
        });
}