samplecode/helloworld/enclave/src/lib.rs

// Copyright (c) 2017 Baidu, Inc. All Rights Reserved.
//
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// modification, are permitted provided that the following conditions
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//
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#![crate_name = "helloworldsampleenclave"]
#![crate_type = "staticlib"]

#![no_std]

extern crate sgx_types;
#[macro_use]
extern crate sgx_tstd as std;
use sgx_types::*;
use std::string::String;
use std::vec::Vec;
use std::slice;
use std::io::{self, Write};

/// A function simply invokes ocall print to print the incoming string
///
/// # Parameters
///
/// **some_string**
///
/// A pointer to the string to be printed
///
/// **len**
///
/// An unsigned int indicates the length of str
///
/// # Return value
///
/// Always returns SGX_SUCCESS
#[no_mangle]
pub extern "C" fn say_something(some_string: *const u8, some_len: usize) -> sgx_status_t {
    
    let str_slice = unsafe { slice::from_raw_parts(some_string, some_len) };
    let _ = io::stdout().write(str_slice);

    // A sample &'static string
    let rust_raw_string = "This is a ";
    // An array
    let word:[u8;4] = [82, 117, 115, 116];
    // An vector
    let word_vec:Vec<u8> = vec![32, 115, 116, 114, 105, 110, 103, 33];

    // Construct a string from &'static string
    let mut hello_string = String::from(rust_raw_string);

    // Iterate on word array
    for c in word.iter() {
        hello_string.push(*c as char);
    }

    // Rust style convertion
    hello_string += String::from_utf8(word_vec).expect("Invalid UTF-8")
                                               .as_str();

    // Ocall to normal world for output
    println!("{}", &hello_string);

    sgx_status_t::SGX_SUCCESS
}