Update for latest nightly 2018-06-09 (#70)

* Update for latest nightly 2018-06-09
* We now have a proper horizon os and sys modules in libstd

1 files changed, 804 insertions, 0 deletions

diff --git a/ctr-std/src/sys/windows/fs.rs b/ctr-std/src/sys/windows/fs.rs
new file mode 100644
index 0000000..082d468
--- /dev/null
+++ b/ctr-std/src/sys/windows/fs.rs
@@ -0,0 +1,804 @@
+// 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 os::windows::prelude::*;
+
+use ffi::OsString;
+use fmt;
+use io::{self, Error, SeekFrom};
+use mem;
+use path::{Path, PathBuf};
+use ptr;
+use slice;
+use sync::Arc;
+use sys::handle::Handle;
+use sys::time::SystemTime;
+use sys::{c, cvt};
+use sys_common::FromInner;
+
+use super::to_u16s;
+
+pub struct File { handle: Handle }
+
+#[derive(Clone)]
+pub struct FileAttr {
+    attributes: c::DWORD,
+    creation_time: c::FILETIME,
+    last_access_time: c::FILETIME,
+    last_write_time: c::FILETIME,
+    file_size: u64,
+    reparse_tag: c::DWORD,
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+pub struct FileType {
+    attributes: c::DWORD,
+    reparse_tag: c::DWORD,
+}
+
+pub struct ReadDir {
+    handle: FindNextFileHandle,
+    root: Arc<PathBuf>,
+    first: Option<c::WIN32_FIND_DATAW>,
+}
+
+struct FindNextFileHandle(c::HANDLE);
+
+unsafe impl Send for FindNextFileHandle {}
+unsafe impl Sync for FindNextFileHandle {}
+
+pub struct DirEntry {
+    root: Arc<PathBuf>,
+    data: c::WIN32_FIND_DATAW,
+}
+
+#[derive(Clone, Debug)]
+pub struct OpenOptions {
+    // generic
+    read: bool,
+    write: bool,
+    append: bool,
+    truncate: bool,
+    create: bool,
+    create_new: bool,
+    // system-specific
+    custom_flags: u32,
+    access_mode: Option<c::DWORD>,
+    attributes: c::DWORD,
+    share_mode: c::DWORD,
+    security_qos_flags: c::DWORD,
+    security_attributes: usize, // FIXME: should be a reference
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct FilePermissions { attrs: c::DWORD }
+
+#[derive(Debug)]
+pub struct DirBuilder;
+
+impl fmt::Debug for ReadDir {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        // This will only be called from std::fs::ReadDir, which will add a "ReadDir()" frame.
+        // Thus the result will be e g 'ReadDir("C:\")'
+        fmt::Debug::fmt(&*self.root, f)
+    }
+}
+
+impl Iterator for ReadDir {
+    type Item = io::Result<DirEntry>;
+    fn next(&mut self) -> Option<io::Result<DirEntry>> {
+        if let Some(first) = self.first.take() {
+            if let Some(e) = DirEntry::new(&self.root, &first) {
+                return Some(Ok(e));
+            }
+        }
+        unsafe {
+            let mut wfd = mem::zeroed();
+            loop {
+                if c::FindNextFileW(self.handle.0, &mut wfd) == 0 {
+                    if c::GetLastError() == c::ERROR_NO_MORE_FILES {
+                        return None
+                    } else {
+                        return Some(Err(Error::last_os_error()))
+                    }
+                }
+                if let Some(e) = DirEntry::new(&self.root, &wfd) {
+                    return Some(Ok(e))
+                }
+            }
+        }
+    }
+}
+
+impl Drop for FindNextFileHandle {
+    fn drop(&mut self) {
+        let r = unsafe { c::FindClose(self.0) };
+        debug_assert!(r != 0);
+    }
+}
+
+impl DirEntry {
+    fn new(root: &Arc<PathBuf>, wfd: &c::WIN32_FIND_DATAW) -> Option<DirEntry> {
+        match &wfd.cFileName[0..3] {
+            // check for '.' and '..'
+            &[46, 0, ..] |
+            &[46, 46, 0, ..] => return None,
+            _ => {}
+        }
+
+        Some(DirEntry {
+            root: root.clone(),
+            data: *wfd,
+        })
+    }
+
+    pub fn path(&self) -> PathBuf {
+        self.root.join(&self.file_name())
+    }
+
+    pub fn file_name(&self) -> OsString {
+        let filename = super::truncate_utf16_at_nul(&self.data.cFileName);
+        OsString::from_wide(filename)
+    }
+
+    pub fn file_type(&self) -> io::Result<FileType> {
+        Ok(FileType::new(self.data.dwFileAttributes,
+                         /* reparse_tag = */ self.data.dwReserved0))
+    }
+
+    pub fn metadata(&self) -> io::Result<FileAttr> {
+        Ok(FileAttr {
+            attributes: self.data.dwFileAttributes,
+            creation_time: self.data.ftCreationTime,
+            last_access_time: self.data.ftLastAccessTime,
+            last_write_time: self.data.ftLastWriteTime,
+            file_size: ((self.data.nFileSizeHigh as u64) << 32) | (self.data.nFileSizeLow as u64),
+            reparse_tag: if self.data.dwFileAttributes & c::FILE_ATTRIBUTE_REPARSE_POINT != 0 {
+                    // reserved unless this is a reparse point
+                    self.data.dwReserved0
+                } else {
+                    0
+                },
+        })
+    }
+}
+
+impl OpenOptions {
+    pub fn new() -> OpenOptions {
+        OpenOptions {
+            // generic
+            read: false,
+            write: false,
+            append: false,
+            truncate: false,
+            create: false,
+            create_new: false,
+            // system-specific
+            custom_flags: 0,
+            access_mode: None,
+            share_mode: c::FILE_SHARE_READ | c::FILE_SHARE_WRITE | c::FILE_SHARE_DELETE,
+            attributes: 0,
+            security_qos_flags: 0,
+            security_attributes: 0,
+        }
+    }
+
+    pub fn read(&mut self, read: bool) { self.read = read; }
+    pub fn write(&mut self, write: bool) { self.write = write; }
+    pub fn append(&mut self, append: bool) { self.append = append; }
+    pub fn truncate(&mut self, truncate: bool) { self.truncate = truncate; }
+    pub fn create(&mut self, create: bool) { self.create = create; }
+    pub fn create_new(&mut self, create_new: bool) { self.create_new = create_new; }
+
+    pub fn custom_flags(&mut self, flags: u32) { self.custom_flags = flags; }
+    pub fn access_mode(&mut self, access_mode: u32) { self.access_mode = Some(access_mode); }
+    pub fn share_mode(&mut self, share_mode: u32) { self.share_mode = share_mode; }
+    pub fn attributes(&mut self, attrs: u32) { self.attributes = attrs; }
+    pub fn security_qos_flags(&mut self, flags: u32) { self.security_qos_flags = flags; }
+    pub fn security_attributes(&mut self, attrs: c::LPSECURITY_ATTRIBUTES) {
+        self.security_attributes = attrs as usize;
+    }
+
+    fn get_access_mode(&self) -> io::Result<c::DWORD> {
+        const ERROR_INVALID_PARAMETER: i32 = 87;
+
+        match (self.read, self.write, self.append, self.access_mode) {
+            (.., Some(mode)) => Ok(mode),
+            (true,  false, false, None) => Ok(c::GENERIC_READ),
+            (false, true,  false, None) => Ok(c::GENERIC_WRITE),
+            (true,  true,  false, None) => Ok(c::GENERIC_READ | c::GENERIC_WRITE),
+            (false, _,     true,  None) => Ok(c::FILE_GENERIC_WRITE & !c::FILE_WRITE_DATA),
+            (true,  _,     true,  None) => Ok(c::GENERIC_READ |
+                                              (c::FILE_GENERIC_WRITE & !c::FILE_WRITE_DATA)),
+            (false, false, false, None) => Err(Error::from_raw_os_error(ERROR_INVALID_PARAMETER)),
+        }
+    }
+
+    fn get_creation_mode(&self) -> io::Result<c::DWORD> {
+        const ERROR_INVALID_PARAMETER: i32 = 87;
+
+        match (self.write, self.append) {
+            (true, false) => {}
+            (false, false) =>
+                if self.truncate || self.create || self.create_new {
+                    return Err(Error::from_raw_os_error(ERROR_INVALID_PARAMETER));
+                },
+            (_, true) =>
+                if self.truncate && !self.create_new {
+                    return Err(Error::from_raw_os_error(ERROR_INVALID_PARAMETER));
+                },
+        }
+
+        Ok(match (self.create, self.truncate, self.create_new) {
+                (false, false, false) => c::OPEN_EXISTING,
+                (true,  false, false) => c::OPEN_ALWAYS,
+                (false, true,  false) => c::TRUNCATE_EXISTING,
+                (true,  true,  false) => c::CREATE_ALWAYS,
+                (_,      _,    true)  => c::CREATE_NEW,
+           })
+    }
+
+    fn get_flags_and_attributes(&self) -> c::DWORD {
+        self.custom_flags |
+        self.attributes |
+        self.security_qos_flags |
+        if self.security_qos_flags != 0 { c::SECURITY_SQOS_PRESENT } else { 0 } |
+        if self.create_new { c::FILE_FLAG_OPEN_REPARSE_POINT } else { 0 }
+    }
+}
+
+impl File {
+    pub fn open(path: &Path, opts: &OpenOptions) -> io::Result<File> {
+        let path = to_u16s(path)?;
+        let handle = unsafe {
+            c::CreateFileW(path.as_ptr(),
+                           opts.get_access_mode()?,
+                           opts.share_mode,
+                           opts.security_attributes as *mut _,
+                           opts.get_creation_mode()?,
+                           opts.get_flags_and_attributes(),
+                           ptr::null_mut())
+        };
+        if handle == c::INVALID_HANDLE_VALUE {
+            Err(Error::last_os_error())
+        } else {
+            Ok(File { handle: Handle::new(handle) })
+        }
+    }
+
+    pub fn fsync(&self) -> io::Result<()> {
+        cvt(unsafe { c::FlushFileBuffers(self.handle.raw()) })?;
+        Ok(())
+    }
+
+    pub fn datasync(&self) -> io::Result<()> { self.fsync() }
+
+    pub fn truncate(&self, size: u64) -> io::Result<()> {
+        let mut info = c::FILE_END_OF_FILE_INFO {
+            EndOfFile: size as c::LARGE_INTEGER,
+        };
+        let size = mem::size_of_val(&info);
+        cvt(unsafe {
+            c::SetFileInformationByHandle(self.handle.raw(),
+                                          c::FileEndOfFileInfo,
+                                          &mut info as *mut _ as *mut _,
+                                          size as c::DWORD)
+        })?;
+        Ok(())
+    }
+
+    pub fn file_attr(&self) -> io::Result<FileAttr> {
+        unsafe {
+            let mut info: c::BY_HANDLE_FILE_INFORMATION = mem::zeroed();
+            cvt(c::GetFileInformationByHandle(self.handle.raw(),
+                                              &mut info))?;
+            let mut attr = FileAttr {
+                attributes: info.dwFileAttributes,
+                creation_time: info.ftCreationTime,
+                last_access_time: info.ftLastAccessTime,
+                last_write_time: info.ftLastWriteTime,
+                file_size: ((info.nFileSizeHigh as u64) << 32) | (info.nFileSizeLow as u64),
+                reparse_tag: 0,
+            };
+            if attr.is_reparse_point() {
+                let mut b = [0; c::MAXIMUM_REPARSE_DATA_BUFFER_SIZE];
+                if let Ok((_, buf)) = self.reparse_point(&mut b) {
+                    attr.reparse_tag = buf.ReparseTag;
+                }
+            }
+            Ok(attr)
+        }
+    }
+
+    pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
+        self.handle.read(buf)
+    }
+
+    pub fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> {
+        self.handle.read_at(buf, offset)
+    }
+
+    pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
+        self.handle.write(buf)
+    }
+
+    pub fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
+        self.handle.write_at(buf, offset)
+    }
+
+    pub fn flush(&self) -> io::Result<()> { Ok(()) }
+
+    pub fn seek(&self, pos: SeekFrom) -> io::Result<u64> {
+        let (whence, pos) = match pos {
+            // Casting to `i64` is fine, `SetFilePointerEx` reinterprets this
+            // integer as `u64`.
+            SeekFrom::Start(n) => (c::FILE_BEGIN, n as i64),
+            SeekFrom::End(n) => (c::FILE_END, n),
+            SeekFrom::Current(n) => (c::FILE_CURRENT, n),
+        };
+        let pos = pos as c::LARGE_INTEGER;
+        let mut newpos = 0;
+        cvt(unsafe {
+            c::SetFilePointerEx(self.handle.raw(), pos,
+                                &mut newpos, whence)
+        })?;
+        Ok(newpos as u64)
+    }
+
+    pub fn duplicate(&self) -> io::Result<File> {
+        Ok(File {
+            handle: self.handle.duplicate(0, true, c::DUPLICATE_SAME_ACCESS)?,
+        })
+    }
+
+    pub fn handle(&self) -> &Handle { &self.handle }
+
+    pub fn into_handle(self) -> Handle { self.handle }
+
+    fn reparse_point<'a>(&self,
+                         space: &'a mut [u8; c::MAXIMUM_REPARSE_DATA_BUFFER_SIZE])
+                         -> io::Result<(c::DWORD, &'a c::REPARSE_DATA_BUFFER)> {
+        unsafe {
+            let mut bytes = 0;
+            cvt({
+                c::DeviceIoControl(self.handle.raw(),
+                                   c::FSCTL_GET_REPARSE_POINT,
+                                   ptr::null_mut(),
+                                   0,
+                                   space.as_mut_ptr() as *mut _,
+                                   space.len() as c::DWORD,
+                                   &mut bytes,
+                                   ptr::null_mut())
+            })?;
+            Ok((bytes, &*(space.as_ptr() as *const c::REPARSE_DATA_BUFFER)))
+        }
+    }
+
+    fn readlink(&self) -> io::Result<PathBuf> {
+        let mut space = [0u8; c::MAXIMUM_REPARSE_DATA_BUFFER_SIZE];
+        let (_bytes, buf) = self.reparse_point(&mut space)?;
+        unsafe {
+            let (path_buffer, subst_off, subst_len, relative) = match buf.ReparseTag {
+                c::IO_REPARSE_TAG_SYMLINK => {
+                    let info: *const c::SYMBOLIC_LINK_REPARSE_BUFFER =
+                        &buf.rest as *const _ as *const _;
+                    (&(*info).PathBuffer as *const _ as *const u16,
+                     (*info).SubstituteNameOffset / 2,
+                     (*info).SubstituteNameLength / 2,
+                     (*info).Flags & c::SYMLINK_FLAG_RELATIVE != 0)
+                },
+                c::IO_REPARSE_TAG_MOUNT_POINT => {
+                    let info: *const c::MOUNT_POINT_REPARSE_BUFFER =
+                        &buf.rest as *const _ as *const _;
+                    (&(*info).PathBuffer as *const _ as *const u16,
+                     (*info).SubstituteNameOffset / 2,
+                     (*info).SubstituteNameLength / 2,
+                     false)
+                },
+                _ => return Err(io::Error::new(io::ErrorKind::Other,
+                                               "Unsupported reparse point type"))
+            };
+            let subst_ptr = path_buffer.offset(subst_off as isize);
+            let mut subst = slice::from_raw_parts(subst_ptr, subst_len as usize);
+            // Absolute paths start with an NT internal namespace prefix `\??\`
+            // We should not let it leak through.
+            if !relative && subst.starts_with(&[92u16, 63u16, 63u16, 92u16]) {
+                subst = &subst[4..];
+            }
+            Ok(PathBuf::from(OsString::from_wide(subst)))
+        }
+    }
+
+    pub fn set_permissions(&self, perm: FilePermissions) -> io::Result<()> {
+        let mut info = c::FILE_BASIC_INFO {
+            CreationTime: 0,
+            LastAccessTime: 0,
+            LastWriteTime: 0,
+            ChangeTime: 0,
+            FileAttributes: perm.attrs,
+        };
+        let size = mem::size_of_val(&info);
+        cvt(unsafe {
+            c::SetFileInformationByHandle(self.handle.raw(),
+                                          c::FileBasicInfo,
+                                          &mut info as *mut _ as *mut _,
+                                          size as c::DWORD)
+        })?;
+        Ok(())
+    }
+}
+
+impl FromInner<c::HANDLE> for File {
+    fn from_inner(handle: c::HANDLE) -> File {
+        File { handle: Handle::new(handle) }
+    }
+}
+
+impl fmt::Debug for File {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        // FIXME(#24570): add more info here (e.g. mode)
+        let mut b = f.debug_struct("File");
+        b.field("handle", &self.handle.raw());
+        if let Ok(path) = get_path(&self) {
+            b.field("path", &path);
+        }
+        b.finish()
+    }
+}
+
+impl FileAttr {
+    pub fn size(&self) -> u64 {
+        self.file_size
+    }
+
+    pub fn perm(&self) -> FilePermissions {
+        FilePermissions { attrs: self.attributes }
+    }
+
+    pub fn attrs(&self) -> u32 { self.attributes as u32 }
+
+    pub fn file_type(&self) -> FileType {
+        FileType::new(self.attributes, self.reparse_tag)
+    }
+
+    pub fn modified(&self) -> io::Result<SystemTime> {
+        Ok(SystemTime::from(self.last_write_time))
+    }
+
+    pub fn accessed(&self) -> io::Result<SystemTime> {
+        Ok(SystemTime::from(self.last_access_time))
+    }
+
+    pub fn created(&self) -> io::Result<SystemTime> {
+        Ok(SystemTime::from(self.creation_time))
+    }
+
+    pub fn modified_u64(&self) -> u64 {
+        to_u64(&self.last_write_time)
+    }
+
+    pub fn accessed_u64(&self) -> u64 {
+        to_u64(&self.last_access_time)
+    }
+
+    pub fn created_u64(&self) -> u64 {
+        to_u64(&self.creation_time)
+    }
+
+    fn is_reparse_point(&self) -> bool {
+        self.attributes & c::FILE_ATTRIBUTE_REPARSE_POINT != 0
+    }
+}
+
+fn to_u64(ft: &c::FILETIME) -> u64 {
+    (ft.dwLowDateTime as u64) | ((ft.dwHighDateTime as u64) << 32)
+}
+
+impl FilePermissions {
+    pub fn readonly(&self) -> bool {
+        self.attrs & c::FILE_ATTRIBUTE_READONLY != 0
+    }
+
+    pub fn set_readonly(&mut self, readonly: bool) {
+        if readonly {
+            self.attrs |= c::FILE_ATTRIBUTE_READONLY;
+        } else {
+            self.attrs &= !c::FILE_ATTRIBUTE_READONLY;
+        }
+    }
+}
+
+impl FileType {
+    fn new(attrs: c::DWORD, reparse_tag: c::DWORD) -> FileType {
+        FileType {
+            attributes: attrs,
+            reparse_tag: reparse_tag,
+        }
+    }
+    pub fn is_dir(&self) -> bool {
+        !self.is_symlink() && self.is_directory()
+    }
+    pub fn is_file(&self) -> bool {
+        !self.is_symlink() && !self.is_directory()
+    }
+    pub fn is_symlink(&self) -> bool {
+        self.is_reparse_point() && self.is_reparse_tag_name_surrogate()
+    }
+    pub fn is_symlink_dir(&self) -> bool {
+        self.is_symlink() && self.is_directory()
+    }
+    pub fn is_symlink_file(&self) -> bool {
+        self.is_symlink() && !self.is_directory()
+    }
+    fn is_directory(&self) -> bool {
+        self.attributes & c::FILE_ATTRIBUTE_DIRECTORY != 0
+    }
+    fn is_reparse_point(&self) -> bool {
+        self.attributes & c::FILE_ATTRIBUTE_REPARSE_POINT != 0
+    }
+    fn is_reparse_tag_name_surrogate(&self) -> bool {
+        self.reparse_tag & 0x20000000 != 0
+    }
+}
+
+impl DirBuilder {
+    pub fn new() -> DirBuilder { DirBuilder }
+
+    pub fn mkdir(&self, p: &Path) -> io::Result<()> {
+        let p = to_u16s(p)?;
+        cvt(unsafe {
+            c::CreateDirectoryW(p.as_ptr(), ptr::null_mut())
+        })?;
+        Ok(())
+    }
+}
+
+pub fn readdir(p: &Path) -> io::Result<ReadDir> {
+    let root = p.to_path_buf();
+    let star = p.join("*");
+    let path = to_u16s(&star)?;
+
+    unsafe {
+        let mut wfd = mem::zeroed();
+        let find_handle = c::FindFirstFileW(path.as_ptr(), &mut wfd);
+        if find_handle != c::INVALID_HANDLE_VALUE {
+            Ok(ReadDir {
+                handle: FindNextFileHandle(find_handle),
+                root: Arc::new(root),
+                first: Some(wfd),
+            })
+        } else {
+            Err(Error::last_os_error())
+        }
+    }
+}
+
+pub fn unlink(p: &Path) -> io::Result<()> {
+    let p_u16s = to_u16s(p)?;
+    cvt(unsafe { c::DeleteFileW(p_u16s.as_ptr()) })?;
+    Ok(())
+}
+
+pub fn rename(old: &Path, new: &Path) -> io::Result<()> {
+    let old = to_u16s(old)?;
+    let new = to_u16s(new)?;
+    cvt(unsafe {
+        c::MoveFileExW(old.as_ptr(), new.as_ptr(), c::MOVEFILE_REPLACE_EXISTING)
+    })?;
+    Ok(())
+}
+
+pub fn rmdir(p: &Path) -> io::Result<()> {
+    let p = to_u16s(p)?;
+    cvt(unsafe { c::RemoveDirectoryW(p.as_ptr()) })?;
+    Ok(())
+}
+
+pub fn remove_dir_all(path: &Path) -> io::Result<()> {
+    let filetype = lstat(path)?.file_type();
+    if filetype.is_symlink() {
+        // On Windows symlinks to files and directories are removed differently.
+        // rmdir only deletes dir symlinks and junctions, not file symlinks.
+        rmdir(path)
+    } else {
+        remove_dir_all_recursive(path)
+    }
+}
+
+fn remove_dir_all_recursive(path: &Path) -> io::Result<()> {
+    for child in readdir(path)? {
+        let child = child?;
+        let child_type = child.file_type()?;
+        if child_type.is_dir() {
+            remove_dir_all_recursive(&child.path())?;
+        } else if child_type.is_symlink_dir() {
+            rmdir(&child.path())?;
+        } else {
+            unlink(&child.path())?;
+        }
+    }
+    rmdir(path)
+}
+
+pub fn readlink(path: &Path) -> io::Result<PathBuf> {
+    // Open the link with no access mode, instead of generic read.
+    // By default FILE_LIST_DIRECTORY is denied for the junction "C:\Documents and Settings", so
+    // this is needed for a common case.
+    let mut opts = OpenOptions::new();
+    opts.access_mode(0);
+    opts.custom_flags(c::FILE_FLAG_OPEN_REPARSE_POINT |
+                      c::FILE_FLAG_BACKUP_SEMANTICS);
+    let file = File::open(&path, &opts)?;
+    file.readlink()
+}
+
+pub fn symlink(src: &Path, dst: &Path) -> io::Result<()> {
+    symlink_inner(src, dst, false)
+}
+
+pub fn symlink_inner(src: &Path, dst: &Path, dir: bool) -> io::Result<()> {
+    let src = to_u16s(src)?;
+    let dst = to_u16s(dst)?;
+    let flags = if dir { c::SYMBOLIC_LINK_FLAG_DIRECTORY } else { 0 };
+    // Formerly, symlink creation required the SeCreateSymbolicLink privilege. For the Windows 10
+    // Creators Update, Microsoft loosened this to allow unprivileged symlink creation if the
+    // computer is in Developer Mode, but SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE must be
+    // added to dwFlags to opt into this behaviour.
+    let result = cvt(unsafe {
+        c::CreateSymbolicLinkW(dst.as_ptr(), src.as_ptr(),
+                               flags | c::SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE) as c::BOOL
+    });
+    if let Err(err) = result {
+        if err.raw_os_error() == Some(c::ERROR_INVALID_PARAMETER as i32) {
+            // Older Windows objects to SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE,
+            // so if we encounter ERROR_INVALID_PARAMETER, retry without that flag.
+            cvt(unsafe {
+                c::CreateSymbolicLinkW(dst.as_ptr(), src.as_ptr(), flags) as c::BOOL
+            })?;
+        } else {
+            return Err(err);
+        }
+    }
+    Ok(())
+}
+
+pub fn link(src: &Path, dst: &Path) -> io::Result<()> {
+    let src = to_u16s(src)?;
+    let dst = to_u16s(dst)?;
+    cvt(unsafe {
+        c::CreateHardLinkW(dst.as_ptr(), src.as_ptr(), ptr::null_mut())
+    })?;
+    Ok(())
+}
+
+pub fn stat(path: &Path) -> io::Result<FileAttr> {
+    let mut opts = OpenOptions::new();
+    // No read or write permissions are necessary
+    opts.access_mode(0);
+    // This flag is so we can open directories too
+    opts.custom_flags(c::FILE_FLAG_BACKUP_SEMANTICS);
+    let file = File::open(path, &opts)?;
+    file.file_attr()
+}
+
+pub fn lstat(path: &Path) -> io::Result<FileAttr> {
+    let mut opts = OpenOptions::new();
+    // No read or write permissions are necessary
+    opts.access_mode(0);
+    opts.custom_flags(c::FILE_FLAG_BACKUP_SEMANTICS | c::FILE_FLAG_OPEN_REPARSE_POINT);
+    let file = File::open(path, &opts)?;
+    file.file_attr()
+}
+
+pub fn set_perm(p: &Path, perm: FilePermissions) -> io::Result<()> {
+    let p = to_u16s(p)?;
+    unsafe {
+        cvt(c::SetFileAttributesW(p.as_ptr(), perm.attrs))?;
+        Ok(())
+    }
+}
+
+fn get_path(f: &File) -> io::Result<PathBuf> {
+    super::fill_utf16_buf(|buf, sz| unsafe {
+        c::GetFinalPathNameByHandleW(f.handle.raw(), buf, sz,
+                                     c::VOLUME_NAME_DOS)
+    }, |buf| {
+        PathBuf::from(OsString::from_wide(buf))
+    })
+}
+
+pub fn canonicalize(p: &Path) -> io::Result<PathBuf> {
+    let mut opts = OpenOptions::new();
+    // No read or write permissions are necessary
+    opts.access_mode(0);
+    // This flag is so we can open directories too
+    opts.custom_flags(c::FILE_FLAG_BACKUP_SEMANTICS);
+    let f = File::open(p, &opts)?;
+    get_path(&f)
+}
+
+pub fn copy(from: &Path, to: &Path) -> io::Result<u64> {
+    unsafe extern "system" fn callback(
+        _TotalFileSize: c::LARGE_INTEGER,
+        _TotalBytesTransferred: c::LARGE_INTEGER,
+        _StreamSize: c::LARGE_INTEGER,
+        StreamBytesTransferred: c::LARGE_INTEGER,
+        dwStreamNumber: c::DWORD,
+        _dwCallbackReason: c::DWORD,
+        _hSourceFile: c::HANDLE,
+        _hDestinationFile: c::HANDLE,
+        lpData: c::LPVOID,
+    ) -> c::DWORD {
+        if dwStreamNumber == 1 {*(lpData as *mut i64) = StreamBytesTransferred;}
+        c::PROGRESS_CONTINUE
+    }
+    let pfrom = to_u16s(from)?;
+    let pto = to_u16s(to)?;
+    let mut size = 0i64;
+    cvt(unsafe {
+        c::CopyFileExW(pfrom.as_ptr(), pto.as_ptr(), Some(callback),
+                       &mut size as *mut _ as *mut _, ptr::null_mut(), 0)
+    })?;
+    Ok(size as u64)
+}
+
+#[allow(dead_code)]
+pub fn symlink_junction<P: AsRef<Path>, Q: AsRef<Path>>(src: P, dst: Q) -> io::Result<()> {
+    symlink_junction_inner(src.as_ref(), dst.as_ref())
+}
+
+// Creating a directory junction on windows involves dealing with reparse
+// points and the DeviceIoControl function, and this code is a skeleton of
+// what can be found here:
+//
+// http://www.flexhex.com/docs/articles/hard-links.phtml
+#[allow(dead_code)]
+fn symlink_junction_inner(target: &Path, junction: &Path) -> io::Result<()> {
+    let d = DirBuilder::new();
+    d.mkdir(&junction)?;
+
+    let mut opts = OpenOptions::new();
+    opts.write(true);
+    opts.custom_flags(c::FILE_FLAG_OPEN_REPARSE_POINT |
+                      c::FILE_FLAG_BACKUP_SEMANTICS);
+    let f = File::open(junction, &opts)?;
+    let h = f.handle().raw();
+
+    unsafe {
+        let mut data = [0u8; c::MAXIMUM_REPARSE_DATA_BUFFER_SIZE];
+        let db = data.as_mut_ptr()
+                    as *mut c::REPARSE_MOUNTPOINT_DATA_BUFFER;
+        let buf = &mut (*db).ReparseTarget as *mut c::WCHAR;
+        let mut i = 0;
+        // FIXME: this conversion is very hacky
+        let v = br"\??\";
+        let v = v.iter().map(|x| *x as u16);
+        for c in v.chain(target.as_os_str().encode_wide()) {
+            *buf.offset(i) = c;
+            i += 1;
+        }
+        *buf.offset(i) = 0;
+        i += 1;
+        (*db).ReparseTag = c::IO_REPARSE_TAG_MOUNT_POINT;
+        (*db).ReparseTargetMaximumLength = (i * 2) as c::WORD;
+        (*db).ReparseTargetLength = ((i - 1) * 2) as c::WORD;
+        (*db).ReparseDataLength =
+                (*db).ReparseTargetLength as c::DWORD + 12;
+
+        let mut ret = 0;
+        cvt(c::DeviceIoControl(h as *mut _,
+                               c::FSCTL_SET_REPARSE_POINT,
+                               data.as_ptr() as *mut _,
+                               (*db).ReparseDataLength + 8,
+                               ptr::null_mut(), 0,
+                               &mut ret,
+                               ptr::null_mut())).map(|_| ())
+    }
+}