library/std/src/sys/windows/mod.rs

   1 #![allow(missing_docs, nonstandard_style)]
   2
   3 use crate::ffi::{CStr, OsStr, OsString};
   4 use crate::io::ErrorKind;
   5 use crate::mem::MaybeUninit;
   6 use crate::os::windows::ffi::{OsStrExt, OsStringExt};
   7 use crate::path::PathBuf;
   8 use crate::time::Duration;
   9
  10 pub use self::rand::hashmap_random_keys;
  11
  12 #[macro_use]
  13 pub mod compat;
  14
  15 pub mod alloc;
  16 pub mod args;
  17 pub mod c;
  18 pub mod cmath;
  19 pub mod env;
  20 pub mod fs;
  21 pub mod handle;
  22 pub mod io;
  23 pub mod locks;
  24 pub mod memchr;
  25 pub mod net;
  26 pub mod os;
  27 pub mod os_str;
  28 pub mod path;
  29 pub mod pipe;
  30 pub mod process;
  31 pub mod rand;
  32 pub mod stdio;
  33 pub mod thread;
  34 pub mod thread_local_dtor;
  35 pub mod thread_local_key;
  36 pub mod thread_parking;
  37 pub mod time;
  38 cfg_if::cfg_if! {
  39     if #[cfg(not(target_vendor = "uwp"))] {
  40         pub mod stack_overflow;
  41     } else {
  42         pub mod stack_overflow_uwp;
  43         pub use self::stack_overflow_uwp as stack_overflow;
  44     }
  45 }
  46
  47 // SAFETY: must be called only once during runtime initialization.
  48 // NOTE: this is not guaranteed to run, for example when Rust code is called externally.
  49 pub unsafe fn init(_argc: isize, _argv: *const *const u8, _sigpipe: u8) {
  50     stack_overflow::init();
  51
  52     // Normally, `thread::spawn` will call `Thread::set_name` but since this thread already
  53     // exists, we have to call it ourselves.
  54     thread::Thread::set_name(&CStr::from_bytes_with_nul_unchecked(b"main\0"));
  55 }
  56
  57 // SAFETY: must be called only once during runtime cleanup.
  58 // NOTE: this is not guaranteed to run, for example when the program aborts.
  59 pub unsafe fn cleanup() {
  60     net::cleanup();
  61 }
  62
  63 pub fn decode_error_kind(errno: i32) -> ErrorKind {
  64     use ErrorKind::*;
  65
  66     match errno as c::DWORD {
  67         c::ERROR_ACCESS_DENIED => return PermissionDenied,
  68         c::ERROR_ALREADY_EXISTS => return AlreadyExists,
  69         c::ERROR_FILE_EXISTS => return AlreadyExists,
  70         c::ERROR_BROKEN_PIPE => return BrokenPipe,
  71         c::ERROR_FILE_NOT_FOUND => return NotFound,
  72         c::ERROR_PATH_NOT_FOUND => return NotFound,
  73         c::ERROR_NO_DATA => return BrokenPipe,
  74         c::ERROR_INVALID_NAME => return InvalidFilename,
  75         c::ERROR_INVALID_PARAMETER => return InvalidInput,
  76         c::ERROR_NOT_ENOUGH_MEMORY | c::ERROR_OUTOFMEMORY => return OutOfMemory,
  77         c::ERROR_SEM_TIMEOUT
  78         | c::WAIT_TIMEOUT
  79         | c::ERROR_DRIVER_CANCEL_TIMEOUT
  80         | c::ERROR_OPERATION_ABORTED
  81         | c::ERROR_SERVICE_REQUEST_TIMEOUT
  82         | c::ERROR_COUNTER_TIMEOUT
  83         | c::ERROR_TIMEOUT
  84         | c::ERROR_RESOURCE_CALL_TIMED_OUT
  85         | c::ERROR_CTX_MODEM_RESPONSE_TIMEOUT
  86         | c::ERROR_CTX_CLIENT_QUERY_TIMEOUT
  87         | c::FRS_ERR_SYSVOL_POPULATE_TIMEOUT
  88         | c::ERROR_DS_TIMELIMIT_EXCEEDED
  89         | c::DNS_ERROR_RECORD_TIMED_OUT
  90         | c::ERROR_IPSEC_IKE_TIMED_OUT
  91         | c::ERROR_RUNLEVEL_SWITCH_TIMEOUT
  92         | c::ERROR_RUNLEVEL_SWITCH_AGENT_TIMEOUT => return TimedOut,
  93         c::ERROR_CALL_NOT_IMPLEMENTED => return Unsupported,
  94         c::ERROR_HOST_UNREACHABLE => return HostUnreachable,
  95         c::ERROR_NETWORK_UNREACHABLE => return NetworkUnreachable,
  96         c::ERROR_DIRECTORY => return NotADirectory,
  97         c::ERROR_DIRECTORY_NOT_SUPPORTED => return IsADirectory,
  98         c::ERROR_DIR_NOT_EMPTY => return DirectoryNotEmpty,
  99         c::ERROR_WRITE_PROTECT => return ReadOnlyFilesystem,
 100         c::ERROR_DISK_FULL | c::ERROR_HANDLE_DISK_FULL => return StorageFull,
 101         c::ERROR_SEEK_ON_DEVICE => return NotSeekable,
 102         c::ERROR_DISK_QUOTA_EXCEEDED => return FilesystemQuotaExceeded,
 103         c::ERROR_FILE_TOO_LARGE => return FileTooLarge,
 104         c::ERROR_BUSY => return ResourceBusy,
 105         c::ERROR_POSSIBLE_DEADLOCK => return Deadlock,
 106         c::ERROR_NOT_SAME_DEVICE => return CrossesDevices,
 107         c::ERROR_TOO_MANY_LINKS => return TooManyLinks,
 108         c::ERROR_FILENAME_EXCED_RANGE => return InvalidFilename,
 109         _ => {}
 110     }
 111
 112     match errno {
 113         c::WSAEACCES => PermissionDenied,
 114         c::WSAEADDRINUSE => AddrInUse,
 115         c::WSAEADDRNOTAVAIL => AddrNotAvailable,
 116         c::WSAECONNABORTED => ConnectionAborted,
 117         c::WSAECONNREFUSED => ConnectionRefused,
 118         c::WSAECONNRESET => ConnectionReset,
 119         c::WSAEINVAL => InvalidInput,
 120         c::WSAENOTCONN => NotConnected,
 121         c::WSAEWOULDBLOCK => WouldBlock,
 122         c::WSAETIMEDOUT => TimedOut,
 123         c::WSAEHOSTUNREACH => HostUnreachable,
 124         c::WSAENETDOWN => NetworkDown,
 125         c::WSAENETUNREACH => NetworkUnreachable,
 126
 127         _ => Uncategorized,
 128     }
 129 }
 130
 131 pub fn unrolled_find_u16s(needle: u16, haystack: &[u16]) -> Option<usize> {
 132     let ptr = haystack.as_ptr();
 133     let mut start = &haystack[..];
 134
 135     // For performance reasons unfold the loop eight times.
 136     while start.len() >= 8 {
 137         macro_rules! if_return {
 138             ($($n:literal,)+) => {
 139                 $(
 140                     if start[$n] == needle {
 141                         return Some(((&start[$n] as *const u16).addr() - ptr.addr()) / 2);
 142                     }
 143                 )+
 144             }
 145         }
 146
 147         if_return!(0, 1, 2, 3, 4, 5, 6, 7,);
 148
 149         start = &start[8..];
 150     }
 151
 152     for c in start {
 153         if *c == needle {
 154             return Some(((c as *const u16).addr() - ptr.addr()) / 2);
 155         }
 156     }
 157     None
 158 }
 159
 160 pub fn to_u16s<S: AsRef<OsStr>>(s: S) -> crate::io::Result<Vec<u16>> {
 161     fn inner(s: &OsStr) -> crate::io::Result<Vec<u16>> {
 162         // Most paths are ASCII, so reserve capacity for as much as there are bytes
 163         // in the OsStr plus one for the null-terminating character. We are not
 164         // wasting bytes here as paths created by this function are primarily used
 165         // in an ephemeral fashion.
 166         let mut maybe_result = Vec::with_capacity(s.len() + 1);
 167         maybe_result.extend(s.encode_wide());
 168
 169         if unrolled_find_u16s(0, &maybe_result).is_some() {
 170             return Err(crate::io::const_io_error!(
 171                 ErrorKind::InvalidInput,
 172                 "strings passed to WinAPI cannot contain NULs",
 173             ));
 174         }
 175         maybe_result.push(0);
 176         Ok(maybe_result)
 177     }
 178     inner(s.as_ref())
 179 }
 180
 181 // Many Windows APIs follow a pattern of where we hand a buffer and then they
 182 // will report back to us how large the buffer should be or how many bytes
 183 // currently reside in the buffer. This function is an abstraction over these
 184 // functions by making them easier to call.
 185 //
 186 // The first callback, `f1`, is yielded a (pointer, len) pair which can be
 187 // passed to a syscall. The `ptr` is valid for `len` items (u16 in this case).
 188 // The closure is expected to return what the syscall returns which will be
 189 // interpreted by this function to determine if the syscall needs to be invoked
 190 // again (with more buffer space).
 191 //
 192 // Once the syscall has completed (errors bail out early) the second closure is
 193 // yielded the data which has been read from the syscall. The return value
 194 // from this closure is then the return value of the function.
 195 fn fill_utf16_buf<F1, F2, T>(mut f1: F1, f2: F2) -> crate::io::Result<T>
 196 where
 197     F1: FnMut(*mut u16, c::DWORD) -> c::DWORD,
 198     F2: FnOnce(&[u16]) -> T,
 199 {
 200     // Start off with a stack buf but then spill over to the heap if we end up
 201     // needing more space.
 202     //
 203     // This initial size also works around `GetFullPathNameW` returning
 204     // incorrect size hints for some short paths:
 205     // https://github.com/dylni/normpath/issues/5
 206     let mut stack_buf: [MaybeUninit<u16>; 512] = MaybeUninit::uninit_array();
 207     let mut heap_buf: Vec<MaybeUninit<u16>> = Vec::new();
 208     unsafe {
 209         let mut n = stack_buf.len();
 210         loop {
 211             let buf = if n <= stack_buf.len() {
 212                 &mut stack_buf[..]
 213             } else {
 214                 let extra = n - heap_buf.len();
 215                 heap_buf.reserve(extra);
 216                 // We used `reserve` and not `reserve_exact`, so in theory we
 217                 // may have gotten more than requested. If so, we'd like to use
 218                 // it... so long as we won't cause overflow.
 219                 n = heap_buf.capacity().min(c::DWORD::MAX as usize);
 220                 // Safety: MaybeUninit<u16> does not need initialization
 221                 heap_buf.set_len(n);
 222                 &mut heap_buf[..]
 223             };
 224
 225             // This function is typically called on windows API functions which
 226             // will return the correct length of the string, but these functions
 227             // also return the `0` on error. In some cases, however, the
 228             // returned "correct length" may actually be 0!
 229             //
 230             // To handle this case we call `SetLastError` to reset it to 0 and
 231             // then check it again if we get the "0 error value". If the "last
 232             // error" is still 0 then we interpret it as a 0 length buffer and
 233             // not an actual error.
 234             c::SetLastError(0);
 235             let k = match f1(buf.as_mut_ptr().cast::<u16>(), n as c::DWORD) {
 236                 0 if c::GetLastError() == 0 => 0,
 237                 0 => return Err(crate::io::Error::last_os_error()),
 238                 n => n,
 239             } as usize;
 240             if k == n && c::GetLastError() == c::ERROR_INSUFFICIENT_BUFFER {
 241                 n = n.saturating_mul(2).min(c::DWORD::MAX as usize);
 242             } else if k > n {
 243                 n = k;
 244             } else if k == n {
 245                 // It is impossible to reach this point.
 246                 // On success, k is the returned string length excluding the null.
 247                 // On failure, k is the required buffer length including the null.
 248                 // Therefore k never equals n.
 249                 unreachable!();
 250             } else {
 251                 // Safety: First `k` values are initialized.
 252                 let slice: &[u16] = MaybeUninit::slice_assume_init_ref(&buf[..k]);
 253                 return Ok(f2(slice));
 254             }
 255         }
 256     }
 257 }
 258
 259 fn os2path(s: &[u16]) -> PathBuf {
 260     PathBuf::from(OsString::from_wide(s))
 261 }
 262
 263 pub fn truncate_utf16_at_nul(v: &[u16]) -> &[u16] {
 264     match unrolled_find_u16s(0, v) {
 265         // don't include the 0
 266         Some(i) => &v[..i],
 267         None => v,
 268     }
 269 }
 270
 271 pub trait IsZero {
 272     fn is_zero(&self) -> bool;
 273 }
 274
 275 macro_rules! impl_is_zero {
 276     ($($t:ident)*) => ($(impl IsZero for $t {
 277         fn is_zero(&self) -> bool {
 278             *self == 0
 279         }
 280     })*)
 281 }
 282
 283 impl_is_zero! { i8 i16 i32 i64 isize u8 u16 u32 u64 usize }
 284
 285 pub fn cvt<I: IsZero>(i: I) -> crate::io::Result<I> {
 286     if i.is_zero() { Err(crate::io::Error::last_os_error()) } else { Ok(i) }
 287 }
 288
 289 pub fn dur2timeout(dur: Duration) -> c::DWORD {
 290     // Note that a duration is a (u64, u32) (seconds, nanoseconds) pair, and the
 291     // timeouts in windows APIs are typically u32 milliseconds. To translate, we
 292     // have two pieces to take care of:
 293     //
 294     // * Nanosecond precision is rounded up
 295     // * Greater than u32::MAX milliseconds (50 days) is rounded up to INFINITE
 296     //   (never time out).
 297     dur.as_secs()
 298         .checked_mul(1000)
 299         .and_then(|ms| ms.checked_add((dur.subsec_nanos() as u64) / 1_000_000))
 300         .and_then(|ms| ms.checked_add(if dur.subsec_nanos() % 1_000_000 > 0 { 1 } else { 0 }))
 301         .map(|ms| if ms > <c::DWORD>::MAX as u64 { c::INFINITE } else { ms as c::DWORD })
 302         .unwrap_or(c::INFINITE)
 303 }
 304
 305 /// Use `__fastfail` to abort the process
 306 ///
 307 /// This is the same implementation as in libpanic_abort's `__rust_start_panic`. See
 308 /// that function for more information on `__fastfail`
 309 #[allow(unreachable_code)]
 310 pub fn abort_internal() -> ! {
 311     #[allow(unused)]
 312     const FAST_FAIL_FATAL_APP_EXIT: usize = 7;
 313     #[cfg(not(miri))] // inline assembly does not work in Miri
 314     unsafe {
 315         cfg_if::cfg_if! {
 316             if #[cfg(any(target_arch = "x86", target_arch = "x86_64"))] {
 317                 core::arch::asm!("int $$0x29", in("ecx") FAST_FAIL_FATAL_APP_EXIT);
 318                 crate::intrinsics::unreachable();
 319             } else if #[cfg(all(target_arch = "arm", target_feature = "thumb-mode"))] {
 320                 core::arch::asm!(".inst 0xDEFB", in("r0") FAST_FAIL_FATAL_APP_EXIT);
 321                 crate::intrinsics::unreachable();
 322             } else if #[cfg(target_arch = "aarch64")] {
 323                 core::arch::asm!("brk 0xF003", in("x0") FAST_FAIL_FATAL_APP_EXIT);
 324                 crate::intrinsics::unreachable();
 325             }
 326         }
 327     }
 328     crate::intrinsics::abort();
 329 }
 330
 331 /// Align the inner value to 8 bytes.
 332 ///
 333 /// This is enough for almost all of the buffers we're likely to work with in
 334 /// the Windows APIs we use.
 335 #[repr(C, align(8))]
 336 #[derive(Copy, Clone)]
 337 pub(crate) struct Align8<T: ?Sized>(pub T);