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