You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: windows.rs
    path of file: ./repos/wasmer/lib/emscripten/src/syscalls
    
    the code of the file until where you have to start completion: use crate::utils::{copy_cstr_into_wasm, get_cstr_path};
use crate::varargs::VarArgs;
use crate::EmEnv;
use libc::mkdir;
use libc::open;
use std::env;
use std::ffi::CString;
use std::fs::File;
use std::io::Write;
use std::os::raw::c_int;
use wasmer::FunctionEnvMut;

#[allow(non_camel_case_types)]
type pid_t = c_int;

/// open
pub fn ___syscall5(mut ctx: FunctionEnvMut<EmEnv
    
pub fn ___syscall39(ctx: FunctionEnvMut<EmEnv>, which: c_int, mut varargs: VarArgs) -> c_int {
    debug!("emscripten::___syscall39 (mkdir) {}", which);
    #[cfg(not(feature = "debug"))]
    let _ = which;
    let pathname_addr = varargs.get_str(&ctx);
    let real_path_owned = get_cstr_path(ctx, pathname_addr);
    let real_path = if let Some(ref rp) = real_path_owned {
        rp.as_c_str().as_ptr()
    } else {
        pathname_addr
    };
    unsafe { mkdir(real_path) }
}