src/libstd/sys/windows/fs.rs

   1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 use os::windows::prelude::*;
  12
  13 use ffi::OsString;
  14 use fmt;
  15 use io::{self, Error, SeekFrom};
  16 use mem;
  17 use path::{Path, PathBuf};
  18 use ptr;
  19 use slice;
  20 use sync::Arc;
  21 use sys::handle::Handle;
  22 use sys::time::SystemTime;
  23 use sys::{c, cvt};
  24 use sys_common::FromInner;
  25
  26 use super::to_u16s;
  27
  28 pub struct File { handle: Handle }
  29
  30 #[derive(Clone)]
  31 pub struct FileAttr {
  32     attributes: c::DWORD,
  33     creation_time: c::FILETIME,
  34     last_access_time: c::FILETIME,
  35     last_write_time: c::FILETIME,
  36     file_size: u64,
  37     reparse_tag: c::DWORD,
  38 }
  39
  40 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
  41 pub enum FileType {
  42     Dir, File, SymlinkFile, SymlinkDir, ReparsePoint, MountPoint,
  43 }
  44
  45 pub struct ReadDir {
  46     handle: FindNextFileHandle,
  47     root: Arc<PathBuf>,
  48     first: Option<c::WIN32_FIND_DATAW>,
  49 }
  50
  51 struct FindNextFileHandle(c::HANDLE);
  52
  53 unsafe impl Send for FindNextFileHandle {}
  54 unsafe impl Sync for FindNextFileHandle {}
  55
  56 pub struct DirEntry {
  57     root: Arc<PathBuf>,
  58     data: c::WIN32_FIND_DATAW,
  59 }
  60
  61 #[derive(Clone, Debug)]
  62 pub struct OpenOptions {
  63     // generic
  64     read: bool,
  65     write: bool,
  66     append: bool,
  67     truncate: bool,
  68     create: bool,
  69     create_new: bool,
  70     // system-specific
  71     custom_flags: u32,
  72     access_mode: Option<c::DWORD>,
  73     attributes: c::DWORD,
  74     share_mode: c::DWORD,
  75     security_qos_flags: c::DWORD,
  76     security_attributes: usize, // FIXME: should be a reference
  77 }
  78
  79 #[derive(Clone, PartialEq, Eq, Debug)]
  80 pub struct FilePermissions { attrs: c::DWORD }
  81
  82 #[derive(Debug)]
  83 pub struct DirBuilder;
  84
  85 impl fmt::Debug for ReadDir {
  86     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  87         // This will only be called from std::fs::ReadDir, which will add a "ReadDir()" frame.
  88         // Thus the result will be e g 'ReadDir("C:\")'
  89         fmt::Debug::fmt(&*self.root, f)
  90     }
  91 }
  92
  93 impl Iterator for ReadDir {
  94     type Item = io::Result<DirEntry>;
  95     fn next(&mut self) -> Option<io::Result<DirEntry>> {
  96         if let Some(first) = self.first.take() {
  97             if let Some(e) = DirEntry::new(&self.root, &first) {
  98                 return Some(Ok(e));
  99             }
 100         }
 101         unsafe {
 102             let mut wfd = mem::zeroed();
 103             loop {
 104                 if c::FindNextFileW(self.handle.0, &mut wfd) == 0 {
 105                     if c::GetLastError() == c::ERROR_NO_MORE_FILES {
 106                         return None
 107                     } else {
 108                         return Some(Err(Error::last_os_error()))
 109                     }
 110                 }
 111                 if let Some(e) = DirEntry::new(&self.root, &wfd) {
 112                     return Some(Ok(e))
 113                 }
 114             }
 115         }
 116     }
 117 }
 118
 119 impl Drop for FindNextFileHandle {
 120     fn drop(&mut self) {
 121         let r = unsafe { c::FindClose(self.0) };
 122         debug_assert!(r != 0);
 123     }
 124 }
 125
 126 impl DirEntry {
 127     fn new(root: &Arc<PathBuf>, wfd: &c::WIN32_FIND_DATAW) -> Option<DirEntry> {
 128         match &wfd.cFileName[0..3] {
 129             // check for '.' and '..'
 130             &[46, 0, ..] |
 131             &[46, 46, 0, ..] => return None,
 132             _ => {}
 133         }
 134
 135         Some(DirEntry {
 136             root: root.clone(),
 137             data: *wfd,
 138         })
 139     }
 140
 141     pub fn path(&self) -> PathBuf {
 142         self.root.join(&self.file_name())
 143     }
 144
 145     pub fn file_name(&self) -> OsString {
 146         let filename = super::truncate_utf16_at_nul(&self.data.cFileName);
 147         OsString::from_wide(filename)
 148     }
 149
 150     pub fn file_type(&self) -> io::Result<FileType> {
 151         Ok(FileType::new(self.data.dwFileAttributes,
 152                          /* reparse_tag = */ self.data.dwReserved0))
 153     }
 154
 155     pub fn metadata(&self) -> io::Result<FileAttr> {
 156         Ok(FileAttr {
 157             attributes: self.data.dwFileAttributes,
 158             creation_time: self.data.ftCreationTime,
 159             last_access_time: self.data.ftLastAccessTime,
 160             last_write_time: self.data.ftLastWriteTime,
 161             file_size: ((self.data.nFileSizeHigh as u64) << 32) | (self.data.nFileSizeLow as u64),
 162             reparse_tag: if self.data.dwFileAttributes & c::FILE_ATTRIBUTE_REPARSE_POINT != 0 {
 163                     // reserved unless this is a reparse point
 164                     self.data.dwReserved0
 165                 } else {
 166                     0
 167                 },
 168         })
 169     }
 170 }
 171
 172 impl OpenOptions {
 173     pub fn new() -> OpenOptions {
 174         OpenOptions {
 175             // generic
 176             read: false,
 177             write: false,
 178             append: false,
 179             truncate: false,
 180             create: false,
 181             create_new: false,
 182             // system-specific
 183             custom_flags: 0,
 184             access_mode: None,
 185             share_mode: c::FILE_SHARE_READ | c::FILE_SHARE_WRITE | c::FILE_SHARE_DELETE,
 186             attributes: 0,
 187             security_qos_flags: 0,
 188             security_attributes: 0,
 189         }
 190     }
 191
 192     pub fn read(&mut self, read: bool) { self.read = read; }
 193     pub fn write(&mut self, write: bool) { self.write = write; }
 194     pub fn append(&mut self, append: bool) { self.append = append; }
 195     pub fn truncate(&mut self, truncate: bool) { self.truncate = truncate; }
 196     pub fn create(&mut self, create: bool) { self.create = create; }
 197     pub fn create_new(&mut self, create_new: bool) { self.create_new = create_new; }
 198
 199     pub fn custom_flags(&mut self, flags: u32) { self.custom_flags = flags; }
 200     pub fn access_mode(&mut self, access_mode: u32) { self.access_mode = Some(access_mode); }
 201     pub fn share_mode(&mut self, share_mode: u32) { self.share_mode = share_mode; }
 202     pub fn attributes(&mut self, attrs: u32) { self.attributes = attrs; }
 203     pub fn security_qos_flags(&mut self, flags: u32) { self.security_qos_flags = flags; }
 204     pub fn security_attributes(&mut self, attrs: c::LPSECURITY_ATTRIBUTES) {
 205         self.security_attributes = attrs as usize;
 206     }
 207
 208     fn get_access_mode(&self) -> io::Result<c::DWORD> {
 209         const ERROR_INVALID_PARAMETER: i32 = 87;
 210
 211         match (self.read, self.write, self.append, self.access_mode) {
 212             (.., Some(mode)) => Ok(mode),
 213             (true,  false, false, None) => Ok(c::GENERIC_READ),
 214             (false, true,  false, None) => Ok(c::GENERIC_WRITE),
 215             (true,  true,  false, None) => Ok(c::GENERIC_READ | c::GENERIC_WRITE),
 216             (false, _,     true,  None) => Ok(c::FILE_GENERIC_WRITE & !c::FILE_WRITE_DATA),
 217             (true,  _,     true,  None) => Ok(c::GENERIC_READ |
 218                                               (c::FILE_GENERIC_WRITE & !c::FILE_WRITE_DATA)),
 219             (false, false, false, None) => Err(Error::from_raw_os_error(ERROR_INVALID_PARAMETER)),
 220         }
 221     }
 222
 223     fn get_creation_mode(&self) -> io::Result<c::DWORD> {
 224         const ERROR_INVALID_PARAMETER: i32 = 87;
 225
 226         match (self.write, self.append) {
 227             (true, false) => {}
 228             (false, false) =>
 229                 if self.truncate || self.create || self.create_new {
 230                     return Err(Error::from_raw_os_error(ERROR_INVALID_PARAMETER));
 231                 },
 232             (_, true) =>
 233                 if self.truncate && !self.create_new {
 234                     return Err(Error::from_raw_os_error(ERROR_INVALID_PARAMETER));
 235                 },
 236         }
 237
 238         Ok(match (self.create, self.truncate, self.create_new) {
 239                 (false, false, false) => c::OPEN_EXISTING,
 240                 (true,  false, false) => c::OPEN_ALWAYS,
 241                 (false, true,  false) => c::TRUNCATE_EXISTING,
 242                 (true,  true,  false) => c::CREATE_ALWAYS,
 243                 (_,      _,    true)  => c::CREATE_NEW,
 244            })
 245     }
 246
 247     fn get_flags_and_attributes(&self) -> c::DWORD {
 248         self.custom_flags |
 249         self.attributes |
 250         self.security_qos_flags |
 251         if self.security_qos_flags != 0 { c::SECURITY_SQOS_PRESENT } else { 0 } |
 252         if self.create_new { c::FILE_FLAG_OPEN_REPARSE_POINT } else { 0 }
 253     }
 254 }
 255
 256 impl File {
 257     pub fn open(path: &Path, opts: &OpenOptions) -> io::Result<File> {
 258         let path = to_u16s(path)?;
 259         let handle = unsafe {
 260             c::CreateFileW(path.as_ptr(),
 261                            opts.get_access_mode()?,
 262                            opts.share_mode,
 263                            opts.security_attributes as *mut _,
 264                            opts.get_creation_mode()?,
 265                            opts.get_flags_and_attributes(),
 266                            ptr::null_mut())
 267         };
 268         if handle == c::INVALID_HANDLE_VALUE {
 269             Err(Error::last_os_error())
 270         } else {
 271             Ok(File { handle: Handle::new(handle) })
 272         }
 273     }
 274
 275     pub fn fsync(&self) -> io::Result<()> {
 276         cvt(unsafe { c::FlushFileBuffers(self.handle.raw()) })?;
 277         Ok(())
 278     }
 279
 280     pub fn datasync(&self) -> io::Result<()> { self.fsync() }
 281
 282     pub fn truncate(&self, size: u64) -> io::Result<()> {
 283         let mut info = c::FILE_END_OF_FILE_INFO {
 284             EndOfFile: size as c::LARGE_INTEGER,
 285         };
 286         let size = mem::size_of_val(&info);
 287         cvt(unsafe {
 288             c::SetFileInformationByHandle(self.handle.raw(),
 289                                           c::FileEndOfFileInfo,
 290                                           &mut info as *mut _ as *mut _,
 291                                           size as c::DWORD)
 292         })?;
 293         Ok(())
 294     }
 295
 296     pub fn file_attr(&self) -> io::Result<FileAttr> {
 297         unsafe {
 298             let mut info: c::BY_HANDLE_FILE_INFORMATION = mem::zeroed();
 299             cvt(c::GetFileInformationByHandle(self.handle.raw(),
 300                                               &mut info))?;
 301             let mut attr = FileAttr {
 302                 attributes: info.dwFileAttributes,
 303                 creation_time: info.ftCreationTime,
 304                 last_access_time: info.ftLastAccessTime,
 305                 last_write_time: info.ftLastWriteTime,
 306                 file_size: ((info.nFileSizeHigh as u64) << 32) | (info.nFileSizeLow as u64),
 307                 reparse_tag: 0,
 308             };
 309             if attr.is_reparse_point() {
 310                 let mut b = [0; c::MAXIMUM_REPARSE_DATA_BUFFER_SIZE];
 311                 if let Ok((_, buf)) = self.reparse_point(&mut b) {
 312                     attr.reparse_tag = buf.ReparseTag;
 313                 }
 314             }
 315             Ok(attr)
 316         }
 317     }
 318
 319     pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
 320         self.handle.read(buf)
 321     }
 322
 323     pub fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> {
 324         self.handle.read_at(buf, offset)
 325     }
 326
 327     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
 328         self.handle.write(buf)
 329     }
 330
 331     pub fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
 332         self.handle.write_at(buf, offset)
 333     }
 334
 335     pub fn flush(&self) -> io::Result<()> { Ok(()) }
 336
 337     pub fn seek(&self, pos: SeekFrom) -> io::Result<u64> {
 338         let (whence, pos) = match pos {
 339             // Casting to `i64` is fine, `SetFilePointerEx` reinterprets this
 340             // integer as `u64`.
 341             SeekFrom::Start(n) => (c::FILE_BEGIN, n as i64),
 342             SeekFrom::End(n) => (c::FILE_END, n),
 343             SeekFrom::Current(n) => (c::FILE_CURRENT, n),
 344         };
 345         let pos = pos as c::LARGE_INTEGER;
 346         let mut newpos = 0;
 347         cvt(unsafe {
 348             c::SetFilePointerEx(self.handle.raw(), pos,
 349                                 &mut newpos, whence)
 350         })?;
 351         Ok(newpos as u64)
 352     }
 353
 354     pub fn duplicate(&self) -> io::Result<File> {
 355         Ok(File {
 356             handle: self.handle.duplicate(0, true, c::DUPLICATE_SAME_ACCESS)?,
 357         })
 358     }
 359
 360     pub fn handle(&self) -> &Handle { &self.handle }
 361
 362     pub fn into_handle(self) -> Handle { self.handle }
 363
 364     fn reparse_point<'a>(&self,
 365                          space: &'a mut [u8; c::MAXIMUM_REPARSE_DATA_BUFFER_SIZE])
 366                          -> io::Result<(c::DWORD, &'a c::REPARSE_DATA_BUFFER)> {
 367         unsafe {
 368             let mut bytes = 0;
 369             cvt({
 370                 c::DeviceIoControl(self.handle.raw(),
 371                                    c::FSCTL_GET_REPARSE_POINT,
 372                                    ptr::null_mut(),
 373                                    0,
 374                                    space.as_mut_ptr() as *mut _,
 375                                    space.len() as c::DWORD,
 376                                    &mut bytes,
 377                                    ptr::null_mut())
 378             })?;
 379             Ok((bytes, &*(space.as_ptr() as *const c::REPARSE_DATA_BUFFER)))
 380         }
 381     }
 382
 383     fn readlink(&self) -> io::Result<PathBuf> {
 384         let mut space = [0u8; c::MAXIMUM_REPARSE_DATA_BUFFER_SIZE];
 385         let (_bytes, buf) = self.reparse_point(&mut space)?;
 386         unsafe {
 387             let (path_buffer, subst_off, subst_len, relative) = match buf.ReparseTag {
 388                 c::IO_REPARSE_TAG_SYMLINK => {
 389                     let info: *const c::SYMBOLIC_LINK_REPARSE_BUFFER =
 390                         &buf.rest as *const _ as *const _;
 391                     (&(*info).PathBuffer as *const _ as *const u16,
 392                      (*info).SubstituteNameOffset / 2,
 393                      (*info).SubstituteNameLength / 2,
 394                      (*info).Flags & c::SYMLINK_FLAG_RELATIVE != 0)
 395                 },
 396                 c::IO_REPARSE_TAG_MOUNT_POINT => {
 397                     let info: *const c::MOUNT_POINT_REPARSE_BUFFER =
 398                         &buf.rest as *const _ as *const _;
 399                     (&(*info).PathBuffer as *const _ as *const u16,
 400                      (*info).SubstituteNameOffset / 2,
 401                      (*info).SubstituteNameLength / 2,
 402                      false)
 403                 },
 404                 _ => return Err(io::Error::new(io::ErrorKind::Other,
 405                                                "Unsupported reparse point type"))
 406             };
 407             let subst_ptr = path_buffer.offset(subst_off as isize);
 408             let mut subst = slice::from_raw_parts(subst_ptr, subst_len as usize);
 409             // Absolute paths start with an NT internal namespace prefix `\??\`
 410             // We should not let it leak through.
 411             if !relative && subst.starts_with(&[92u16, 63u16, 63u16, 92u16]) {
 412                 subst = &subst[4..];
 413             }
 414             Ok(PathBuf::from(OsString::from_wide(subst)))
 415         }
 416     }
 417
 418     pub fn set_permissions(&self, perm: FilePermissions) -> io::Result<()> {
 419         let mut info = c::FILE_BASIC_INFO {
 420             CreationTime: 0,
 421             LastAccessTime: 0,
 422             LastWriteTime: 0,
 423             ChangeTime: 0,
 424             FileAttributes: perm.attrs,
 425         };
 426         let size = mem::size_of_val(&info);
 427         cvt(unsafe {
 428             c::SetFileInformationByHandle(self.handle.raw(),
 429                                           c::FileBasicInfo,
 430                                           &mut info as *mut _ as *mut _,
 431                                           size as c::DWORD)
 432         })?;
 433         Ok(())
 434     }
 435 }
 436
 437 impl FromInner<c::HANDLE> for File {
 438     fn from_inner(handle: c::HANDLE) -> File {
 439         File { handle: Handle::new(handle) }
 440     }
 441 }
 442
 443 impl fmt::Debug for File {
 444     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 445         // FIXME(#24570): add more info here (e.g. mode)
 446         let mut b = f.debug_struct("File");
 447         b.field("handle", &self.handle.raw());
 448         if let Ok(path) = get_path(&self) {
 449             b.field("path", &path);
 450         }
 451         b.finish()
 452     }
 453 }
 454
 455 impl FileAttr {
 456     pub fn size(&self) -> u64 {
 457         self.file_size
 458     }
 459
 460     pub fn perm(&self) -> FilePermissions {
 461         FilePermissions { attrs: self.attributes }
 462     }
 463
 464     pub fn attrs(&self) -> u32 { self.attributes as u32 }
 465
 466     pub fn file_type(&self) -> FileType {
 467         FileType::new(self.attributes, self.reparse_tag)
 468     }
 469
 470     pub fn modified(&self) -> io::Result<SystemTime> {
 471         Ok(SystemTime::from(self.last_write_time))
 472     }
 473
 474     pub fn accessed(&self) -> io::Result<SystemTime> {
 475         Ok(SystemTime::from(self.last_access_time))
 476     }
 477
 478     pub fn created(&self) -> io::Result<SystemTime> {
 479         Ok(SystemTime::from(self.creation_time))
 480     }
 481
 482     pub fn modified_u64(&self) -> u64 {
 483         to_u64(&self.last_write_time)
 484     }
 485
 486     pub fn accessed_u64(&self) -> u64 {
 487         to_u64(&self.last_access_time)
 488     }
 489
 490     pub fn created_u64(&self) -> u64 {
 491         to_u64(&self.creation_time)
 492     }
 493
 494     fn is_reparse_point(&self) -> bool {
 495         self.attributes & c::FILE_ATTRIBUTE_REPARSE_POINT != 0
 496     }
 497 }
 498
 499 fn to_u64(ft: &c::FILETIME) -> u64 {
 500     (ft.dwLowDateTime as u64) | ((ft.dwHighDateTime as u64) << 32)
 501 }
 502
 503 impl FilePermissions {
 504     pub fn readonly(&self) -> bool {
 505         self.attrs & c::FILE_ATTRIBUTE_READONLY != 0
 506     }
 507
 508     pub fn set_readonly(&mut self, readonly: bool) {
 509         if readonly {
 510             self.attrs |= c::FILE_ATTRIBUTE_READONLY;
 511         } else {
 512             self.attrs &= !c::FILE_ATTRIBUTE_READONLY;
 513         }
 514     }
 515 }
 516
 517 impl FileType {
 518     fn new(attrs: c::DWORD, reparse_tag: c::DWORD) -> FileType {
 519         match (attrs & c::FILE_ATTRIBUTE_DIRECTORY != 0,
 520                attrs & c::FILE_ATTRIBUTE_REPARSE_POINT != 0,
 521                reparse_tag) {
 522             (false, false, _) => FileType::File,
 523             (true, false, _) => FileType::Dir,
 524             (false, true, c::IO_REPARSE_TAG_SYMLINK) => FileType::SymlinkFile,
 525             (true, true, c::IO_REPARSE_TAG_SYMLINK) => FileType::SymlinkDir,
 526             (true, true, c::IO_REPARSE_TAG_MOUNT_POINT) => FileType::MountPoint,
 527             (_, true, _) => FileType::ReparsePoint,
 528             // Note: if a _file_ has a reparse tag of the type IO_REPARSE_TAG_MOUNT_POINT it is
 529             // invalid, as junctions always have to be dirs. We set the filetype to ReparsePoint
 530             // to indicate it is something symlink-like, but not something you can follow.
 531         }
 532     }
 533
 534     pub fn is_dir(&self) -> bool { *self == FileType::Dir }
 535     pub fn is_file(&self) -> bool { *self == FileType::File }
 536     pub fn is_symlink(&self) -> bool {
 537         *self == FileType::SymlinkFile ||
 538         *self == FileType::SymlinkDir ||
 539         *self == FileType::MountPoint
 540     }
 541     pub fn is_symlink_dir(&self) -> bool {
 542         *self == FileType::SymlinkDir || *self == FileType::MountPoint
 543     }
 544 }
 545
 546 impl DirBuilder {
 547     pub fn new() -> DirBuilder { DirBuilder }
 548
 549     pub fn mkdir(&self, p: &Path) -> io::Result<()> {
 550         let p = to_u16s(p)?;
 551         cvt(unsafe {
 552             c::CreateDirectoryW(p.as_ptr(), ptr::null_mut())
 553         })?;
 554         Ok(())
 555     }
 556 }
 557
 558 pub fn readdir(p: &Path) -> io::Result<ReadDir> {
 559     let root = p.to_path_buf();
 560     let star = p.join("*");
 561     let path = to_u16s(&star)?;
 562
 563     unsafe {
 564         let mut wfd = mem::zeroed();
 565         let find_handle = c::FindFirstFileW(path.as_ptr(), &mut wfd);
 566         if find_handle != c::INVALID_HANDLE_VALUE {
 567             Ok(ReadDir {
 568                 handle: FindNextFileHandle(find_handle),
 569                 root: Arc::new(root),
 570                 first: Some(wfd),
 571             })
 572         } else {
 573             Err(Error::last_os_error())
 574         }
 575     }
 576 }
 577
 578 pub fn unlink(p: &Path) -> io::Result<()> {
 579     let p_u16s = to_u16s(p)?;
 580     cvt(unsafe { c::DeleteFileW(p_u16s.as_ptr()) })?;
 581     Ok(())
 582 }
 583
 584 pub fn rename(old: &Path, new: &Path) -> io::Result<()> {
 585     let old = to_u16s(old)?;
 586     let new = to_u16s(new)?;
 587     cvt(unsafe {
 588         c::MoveFileExW(old.as_ptr(), new.as_ptr(), c::MOVEFILE_REPLACE_EXISTING)
 589     })?;
 590     Ok(())
 591 }
 592
 593 pub fn rmdir(p: &Path) -> io::Result<()> {
 594     let p = to_u16s(p)?;
 595     cvt(unsafe { c::RemoveDirectoryW(p.as_ptr()) })?;
 596     Ok(())
 597 }
 598
 599 pub fn remove_dir_all(path: &Path) -> io::Result<()> {
 600     let filetype = lstat(path)?.file_type();
 601     if filetype.is_symlink() {
 602         // On Windows symlinks to files and directories are removed differently.
 603         // rmdir only deletes dir symlinks and junctions, not file symlinks.
 604         rmdir(path)
 605     } else {
 606         remove_dir_all_recursive(path)
 607     }
 608 }
 609
 610 fn remove_dir_all_recursive(path: &Path) -> io::Result<()> {
 611     for child in readdir(path)? {
 612         let child = child?;
 613         let child_type = child.file_type()?;
 614         if child_type.is_dir() {
 615             remove_dir_all_recursive(&child.path())?;
 616         } else if child_type.is_symlink_dir() {
 617             rmdir(&child.path())?;
 618         } else {
 619             unlink(&child.path())?;
 620         }
 621     }
 622     rmdir(path)
 623 }
 624
 625 pub fn readlink(path: &Path) -> io::Result<PathBuf> {
 626     // Open the link with no access mode, instead of generic read.
 627     // By default FILE_LIST_DIRECTORY is denied for the junction "C:\Documents and Settings", so
 628     // this is needed for a common case.
 629     let mut opts = OpenOptions::new();
 630     opts.access_mode(0);
 631     opts.custom_flags(c::FILE_FLAG_OPEN_REPARSE_POINT |
 632                       c::FILE_FLAG_BACKUP_SEMANTICS);
 633     let file = File::open(&path, &opts)?;
 634     file.readlink()
 635 }
 636
 637 pub fn symlink(src: &Path, dst: &Path) -> io::Result<()> {
 638     symlink_inner(src, dst, false)
 639 }
 640
 641 pub fn symlink_inner(src: &Path, dst: &Path, dir: bool) -> io::Result<()> {
 642     let src = to_u16s(src)?;
 643     let dst = to_u16s(dst)?;
 644     let flags = if dir { c::SYMBOLIC_LINK_FLAG_DIRECTORY } else { 0 };
 645     // Formerly, symlink creation required the SeCreateSymbolicLink privilege. For the Windows 10
 646     // Creators Update, Microsoft loosened this to allow unprivileged symlink creation if the
 647     // computer is in Developer Mode, but SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE must be
 648     // added to dwFlags to opt into this behaviour.
 649     let result = cvt(unsafe {
 650         c::CreateSymbolicLinkW(dst.as_ptr(), src.as_ptr(),
 651                                flags | c::SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE) as c::BOOL
 652     });
 653     if let Err(err) = result {
 654         if err.raw_os_error() == Some(c::ERROR_INVALID_PARAMETER as i32) {
 655             // Older Windows objects to SYMBOLIC_LINK_FLAG_ALLOW_UNPRIVILEGED_CREATE,
 656             // so if we encounter ERROR_INVALID_PARAMETER, retry without that flag.
 657             cvt(unsafe {
 658                 c::CreateSymbolicLinkW(dst.as_ptr(), src.as_ptr(), flags) as c::BOOL
 659             })?;
 660         } else {
 661             return Err(err);
 662         }
 663     }
 664     Ok(())
 665 }
 666
 667 pub fn link(src: &Path, dst: &Path) -> io::Result<()> {
 668     let src = to_u16s(src)?;
 669     let dst = to_u16s(dst)?;
 670     cvt(unsafe {
 671         c::CreateHardLinkW(dst.as_ptr(), src.as_ptr(), ptr::null_mut())
 672     })?;
 673     Ok(())
 674 }
 675
 676 pub fn stat(path: &Path) -> io::Result<FileAttr> {
 677     let mut opts = OpenOptions::new();
 678     // No read or write permissions are necessary
 679     opts.access_mode(0);
 680     // This flag is so we can open directories too
 681     opts.custom_flags(c::FILE_FLAG_BACKUP_SEMANTICS);
 682     let file = File::open(path, &opts)?;
 683     file.file_attr()
 684 }
 685
 686 pub fn lstat(path: &Path) -> io::Result<FileAttr> {
 687     let mut opts = OpenOptions::new();
 688     // No read or write permissions are necessary
 689     opts.access_mode(0);
 690     opts.custom_flags(c::FILE_FLAG_BACKUP_SEMANTICS | c::FILE_FLAG_OPEN_REPARSE_POINT);
 691     let file = File::open(path, &opts)?;
 692     file.file_attr()
 693 }
 694
 695 pub fn set_perm(p: &Path, perm: FilePermissions) -> io::Result<()> {
 696     let p = to_u16s(p)?;
 697     unsafe {
 698         cvt(c::SetFileAttributesW(p.as_ptr(), perm.attrs))?;
 699         Ok(())
 700     }
 701 }
 702
 703 fn get_path(f: &File) -> io::Result<PathBuf> {
 704     super::fill_utf16_buf(|buf, sz| unsafe {
 705         c::GetFinalPathNameByHandleW(f.handle.raw(), buf, sz,
 706                                      c::VOLUME_NAME_DOS)
 707     }, |buf| {
 708         PathBuf::from(OsString::from_wide(buf))
 709     })
 710 }
 711
 712 pub fn canonicalize(p: &Path) -> io::Result<PathBuf> {
 713     let mut opts = OpenOptions::new();
 714     // No read or write permissions are necessary
 715     opts.access_mode(0);
 716     // This flag is so we can open directories too
 717     opts.custom_flags(c::FILE_FLAG_BACKUP_SEMANTICS);
 718     let f = File::open(p, &opts)?;
 719     get_path(&f)
 720 }
 721
 722 pub fn copy(from: &Path, to: &Path) -> io::Result<u64> {
 723     unsafe extern "system" fn callback(
 724         _TotalFileSize: c::LARGE_INTEGER,
 725         TotalBytesTransferred: c::LARGE_INTEGER,
 726         _StreamSize: c::LARGE_INTEGER,
 727         _StreamBytesTransferred: c::LARGE_INTEGER,
 728         _dwStreamNumber: c::DWORD,
 729         _dwCallbackReason: c::DWORD,
 730         _hSourceFile: c::HANDLE,
 731         _hDestinationFile: c::HANDLE,
 732         lpData: c::LPVOID,
 733     ) -> c::DWORD {
 734         *(lpData as *mut i64) = TotalBytesTransferred;
 735         c::PROGRESS_CONTINUE
 736     }
 737     let pfrom = to_u16s(from)?;
 738     let pto = to_u16s(to)?;
 739     let mut size = 0i64;
 740     cvt(unsafe {
 741         c::CopyFileExW(pfrom.as_ptr(), pto.as_ptr(), Some(callback),
 742                        &mut size as *mut _ as *mut _, ptr::null_mut(), 0)
 743     })?;
 744     Ok(size as u64)
 745 }
 746
 747 #[allow(dead_code)]
 748 pub fn symlink_junction<P: AsRef<Path>, Q: AsRef<Path>>(src: P, dst: Q) -> io::Result<()> {
 749     symlink_junction_inner(src.as_ref(), dst.as_ref())
 750 }
 751
 752 // Creating a directory junction on windows involves dealing with reparse
 753 // points and the DeviceIoControl function, and this code is a skeleton of
 754 // what can be found here:
 755 //
 756 // http://www.flexhex.com/docs/articles/hard-links.phtml
 757 #[allow(dead_code)]
 758 fn symlink_junction_inner(target: &Path, junction: &Path) -> io::Result<()> {
 759     let d = DirBuilder::new();
 760     d.mkdir(&junction)?;
 761
 762     let mut opts = OpenOptions::new();
 763     opts.write(true);
 764     opts.custom_flags(c::FILE_FLAG_OPEN_REPARSE_POINT |
 765                       c::FILE_FLAG_BACKUP_SEMANTICS);
 766     let f = File::open(junction, &opts)?;
 767     let h = f.handle().raw();
 768
 769     unsafe {
 770         let mut data = [0u8; c::MAXIMUM_REPARSE_DATA_BUFFER_SIZE];
 771         let db = data.as_mut_ptr()
 772                     as *mut c::REPARSE_MOUNTPOINT_DATA_BUFFER;
 773         let buf = &mut (*db).ReparseTarget as *mut _;
 774         let mut i = 0;
 775         // FIXME: this conversion is very hacky
 776         let v = br"\??\";
 777         let v = v.iter().map(|x| *x as u16);
 778         for c in v.chain(target.as_os_str().encode_wide()) {
 779             *buf.offset(i) = c;
 780             i += 1;
 781         }
 782         *buf.offset(i) = 0;
 783         i += 1;
 784         (*db).ReparseTag = c::IO_REPARSE_TAG_MOUNT_POINT;
 785         (*db).ReparseTargetMaximumLength = (i * 2) as c::WORD;
 786         (*db).ReparseTargetLength = ((i - 1) * 2) as c::WORD;
 787         (*db).ReparseDataLength =
 788                 (*db).ReparseTargetLength as c::DWORD + 12;
 789
 790         let mut ret = 0;
 791         cvt(c::DeviceIoControl(h as *mut _,
 792                                c::FSCTL_SET_REPARSE_POINT,
 793                                data.as_ptr() as *mut _,
 794                                (*db).ReparseDataLength + 8,
 795                                ptr::null_mut(), 0,
 796                                &mut ret,
 797                                ptr::null_mut())).map(|_| ())
 798     }
 799 }