Empty Win32 MessageBox using rust no_std

gistfile1.rs

This generates a win 32bit exe with of ~48 KB (~35 KB after upx compression). Tested with rust nightly of May 16th 2015
https://static.rust-lang.org/dist/2015-05-16/rust-nightly-i686-pc-windows-gnu.msi

Command line: 
cargo clean && cargo build -v --release

Cargo.toml:
[package]
name = "msgbox"
version = "0.1.0"
authors = ["kosta"]

[profile.release]
opt-level = 3
debug = false
rpath = false
lto = true
debug-assertions = false
codegen-units = 1

src/main.rs:
#![feature(lang_items, start, no_std, core, libc)]
#![no_std]

// Pull in the system libc library for what crt0.o likely requires
extern crate libc;
extern crate core;

use core::ptr;

// These functions and traits are used by the compiler, but not
// for a bare-bones hello world. These are normally
// provided by libstd.
#[lang = "stack_exhausted"] extern fn stack_exhausted() {}
#[lang = "eh_personality"] extern fn eh_personality() {}
#[lang = "panic_fmt"] fn panic_fmt() -> ! { loop {} }

mod ffi {
    extern "stdcall" {
        pub fn MessageBoxW(
            hWnd: *const (),
            lpText: *const u16,
            lpCaption: *const u16,
            uType: u32
        ) -> i32;
    }
}
 
// Entry point for this program
#[start]
fn start(_argc: isize, _argv: *const *const u8) -> isize {
    unsafe {
        ffi::MessageBoxW(
            ptr::null(),
            ptr::null(),
            ptr::null(),
            0);
    }
    0
}