rust/src/librustc_back/fs.rs

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// 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.
use std::io;
use std::io::fs;
use std::os;
/// Returns an absolute path in the filesystem that `path` points to. The
/// returned path does not contain any symlinks in its hierarchy.
pub fn realpath(original: &Path) -> io::IoResult<Path> {
static MAX_LINKS_FOLLOWED: uint = 256;
let original = os::make_absolute(original);
// Right now lstat on windows doesn't work quite well
if cfg!(windows) {
return Ok(original)
}
let result = original.root_path();
let mut result = result.expect("make_absolute has no root_path");
let mut followed = 0;
for part in original.components() {
result.push(part);
loop {
if followed == MAX_LINKS_FOLLOWED {
return Err(io::standard_error(io::InvalidInput))
}
match fs::lstat(&result) {
Err(..) => break,
Ok(ref stat) if stat.kind != io::TypeSymlink => break,
Ok(..) => {
followed += 1;
let path = try!(fs::readlink(&result));
result.pop();
result.push(path);
}
}
}
}
return Ok(result);
}
#[cfg(not(windows), test)]
mod test {
use std::io;
use std::io::fs::{File, symlink, mkdir, mkdir_recursive};
use super::realpath;
use std::io::TempDir;
#[test]
fn realpath_works() {
let tmpdir = TempDir::new("rustc-fs").unwrap();
let tmpdir = realpath(tmpdir.path()).unwrap();
let file = tmpdir.join("test");
let dir = tmpdir.join("test2");
let link = dir.join("link");
let linkdir = tmpdir.join("test3");
File::create(&file).unwrap();
mkdir(&dir, io::UserRWX).unwrap();
symlink(&file, &link).unwrap();
symlink(&dir, &linkdir).unwrap();
assert!(realpath(&tmpdir).unwrap() == tmpdir);
assert!(realpath(&file).unwrap() == file);
assert!(realpath(&link).unwrap() == file);
assert!(realpath(&linkdir).unwrap() == dir);
assert!(realpath(&linkdir.join("link")).unwrap() == file);
}
#[test]
fn realpath_works_tricky() {
let tmpdir = TempDir::new("rustc-fs").unwrap();
let tmpdir = realpath(tmpdir.path()).unwrap();
let a = tmpdir.join("a");
let b = a.join("b");
let c = b.join("c");
let d = a.join("d");
let e = d.join("e");
let f = a.join("f");
mkdir_recursive(&b, io::UserRWX).unwrap();
mkdir_recursive(&d, io::UserRWX).unwrap();
File::create(&f).unwrap();
symlink(&Path::new("../d/e"), &c).unwrap();
symlink(&Path::new("../f"), &e).unwrap();
assert!(realpath(&c).unwrap() == f);
assert!(realpath(&e).unwrap() == f);
}
}