Commit fb06182b authored by Stefan Lankes's avatar Stefan Lankes
Browse files

remove dependency to the cargo command xbuild

parent fadab476
// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! This library is derived from rlibc, not intended for general use,
//! and is superseded by a system libc if one is available. In a
//! freestanding context, however, common functions such as memset, memcpy,
//! etc are not implemented. This library provides an implementation of
//! these functions which are either required by libcore or called by rustc
//! implicitly.
#[no_mangle]
pub unsafe extern "C" fn memcpy(dest: *mut u8, src: *const u8, n: usize) -> *mut u8 {
let mut i = 0;
while i < n {
*dest.add(i) = *src.add(i);
i += 1;
}
dest
}
#[no_mangle]
pub unsafe extern "C" fn memmove(dest: *mut u8, src: *const u8, n: usize) -> *mut u8 {
if src < dest as *const u8 {
// copy from end
let mut i = n;
while i != 0 {
i -= 1;
*dest.add(i) = *src.add(i);
}
} else {
// copy from beginning
let mut i = 0;
while i < n {
*dest.add(i) = *src.add(i);
i += 1;
}
}
dest
}
#[no_mangle]
pub unsafe extern "C" fn memset(s: *mut u8, c: i32, n: usize) -> *mut u8 {
let mut i = 0;
while i < n {
*s.add(i) = c as u8;
i += 1;
}
s
}
#[no_mangle]
pub unsafe extern "C" fn memcmp(s1: *const u8, s2: *const u8, n: usize) -> i32 {
let mut i = 0;
while i < n {
let a = *s1.add(i);
let b = *s2.add(i);
if a != b {
return a as i32 - b as i32;
}
i += 1;
}
0
}
#[cfg(test)]
mod test {
use super::{memcmp, memcpy, memmove, memset};
#[test]
fn memcmp_single_byte_pointers() {
unsafe {
assert_eq!(memcmp(&0xFAu8, &0xFAu8, 1), 0x00);
assert!(memcmp(&0xEFu8, &0xFEu8, 1) < 0x00);
}
}
#[test]
fn memcmp_strings() {
{
let (x, z) = ("Hello!", "Good Bye.");
let l = x.len();
unsafe {
assert_eq!(memcmp(x.as_ptr(), x.as_ptr(), l), 0);
assert!(memcmp(x.as_ptr(), z.as_ptr(), l) > 0);
assert!(memcmp(z.as_ptr(), x.as_ptr(), l) < 0);
}
}
{
let (x, z) = ("hey!", "hey.");
let l = x.len();
unsafe {
assert!(memcmp(x.as_ptr(), z.as_ptr(), l) < 0);
}
}
}
#[test]
fn memset_single_byte_pointers() {
let mut x: u8 = 0xFF;
unsafe {
memset(&mut x, 0xAA, 1);
assert_eq!(x, 0xAA);
memset(&mut x, 0x00, 1);
assert_eq!(x, 0x00);
x = 0x01;
memset(&mut x, 0x12, 0);
assert_eq!(x, 0x01);
}
}
#[test]
fn memset_array() {
let mut buffer = [b'X'; 100];
unsafe {
memset(buffer.as_mut_ptr(), b'#' as i32, buffer.len());
}
for byte in buffer.iter() {
assert_eq!(*byte, b'#');
}
}
#[test]
fn memcpy_and_memcmp_arrays() {
let (src, mut dst) = ([b'X'; 100], [b'Y'; 100]);
unsafe {
assert!(memcmp(src.as_ptr(), dst.as_ptr(), 100) != 0);
let _ = memcpy(dst.as_mut_ptr(), src.as_ptr(), 100);
assert_eq!(memcmp(src.as_ptr(), dst.as_ptr(), 100), 0);
}
}
#[test]
fn memmove_overlapping() {
{
let mut buffer = [b'0', b'1', b'2', b'3', b'4', b'5', b'6', b'7', b'8', b'9'];
unsafe {
memmove(&mut buffer[4], &buffer[0], 6);
let mut i = 0;
for byte in b"0123012345".iter() {
assert_eq!(buffer[i], *byte);
i += 1;
}
}
}
{
let mut buffer = [b'0', b'1', b'2', b'3', b'4', b'5', b'6', b'7', b'8', b'9'];
unsafe {
memmove(&mut buffer[0], &buffer[4], 6);
let mut i = 0;
for byte in b"4567896789".iter() {
assert_eq!(buffer[i], *byte);
i += 1;
}
}
}
}
}
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