src/libstd/sys/windows/mod.rs

   1 #![allow(missing_docs, nonstandard_style)]
   2
   3 use crate::ffi::{OsStr, OsString};
   4 use crate::io::ErrorKind;
   5 use crate::os::windows::ffi::{OsStrExt, OsStringExt};
   6 use crate::path::PathBuf;
   7 use crate::ptr;
   8 use crate::time::Duration;
   9
  10 pub use self::rand::hashmap_random_keys;
  11 pub use libc::strlen;
  12
  13 #[macro_use]
  14 pub mod compat;
  15
  16 pub mod alloc;
  17 pub mod args;
  18 pub mod c;
  19 pub mod cmath;
  20 pub mod condvar;
  21 pub mod env;
  22 pub mod ext;
  23 pub mod fast_thread_local;
  24 pub mod fs;
  25 pub mod handle;
  26 pub mod io;
  27 pub mod memchr;
  28 pub mod mutex;
  29 pub mod net;
  30 pub mod os;
  31 pub mod os_str;
  32 pub mod path;
  33 pub mod pipe;
  34 pub mod process;
  35 pub mod rand;
  36 pub mod rwlock;
  37 pub mod thread;
  38 pub mod thread_local;
  39 pub mod time;
  40 cfg_if::cfg_if! {
  41     if #[cfg(not(target_vendor = "uwp"))] {
  42         pub mod stdio;
  43         pub mod stack_overflow;
  44     } else {
  45         pub mod stdio_uwp;
  46         pub mod stack_overflow_uwp;
  47         pub use self::stdio_uwp as stdio;
  48         pub use self::stack_overflow_uwp as stack_overflow;
  49     }
  50 }
  51
  52 #[cfg(not(test))]
  53 pub fn init() {}
  54
  55 pub fn decode_error_kind(errno: i32) -> ErrorKind {
  56     match errno as c::DWORD {
  57         c::ERROR_ACCESS_DENIED => return ErrorKind::PermissionDenied,
  58         c::ERROR_ALREADY_EXISTS => return ErrorKind::AlreadyExists,
  59         c::ERROR_FILE_EXISTS => return ErrorKind::AlreadyExists,
  60         c::ERROR_BROKEN_PIPE => return ErrorKind::BrokenPipe,
  61         c::ERROR_FILE_NOT_FOUND => return ErrorKind::NotFound,
  62         c::ERROR_PATH_NOT_FOUND => return ErrorKind::NotFound,
  63         c::ERROR_NO_DATA => return ErrorKind::BrokenPipe,
  64         c::ERROR_OPERATION_ABORTED => return ErrorKind::TimedOut,
  65         _ => {}
  66     }
  67
  68     match errno {
  69         c::WSAEACCES => ErrorKind::PermissionDenied,
  70         c::WSAEADDRINUSE => ErrorKind::AddrInUse,
  71         c::WSAEADDRNOTAVAIL => ErrorKind::AddrNotAvailable,
  72         c::WSAECONNABORTED => ErrorKind::ConnectionAborted,
  73         c::WSAECONNREFUSED => ErrorKind::ConnectionRefused,
  74         c::WSAECONNRESET => ErrorKind::ConnectionReset,
  75         c::WSAEINVAL => ErrorKind::InvalidInput,
  76         c::WSAENOTCONN => ErrorKind::NotConnected,
  77         c::WSAEWOULDBLOCK => ErrorKind::WouldBlock,
  78         c::WSAETIMEDOUT => ErrorKind::TimedOut,
  79
  80         _ => ErrorKind::Other,
  81     }
  82 }
  83
  84 pub fn unrolled_find_u16s(needle: u16, haystack: &[u16]) -> Option<usize> {
  85     let ptr = haystack.as_ptr();
  86     let mut len = haystack.len();
  87     let mut start = &haystack[..];
  88
  89     // For performance reasons unfold the loop eight times.
  90     while len >= 8 {
  91         if start[0] == needle {
  92             return Some((start.as_ptr() as usize - ptr as usize) / 2);
  93         }
  94         if start[1] == needle {
  95             return Some((start[1..].as_ptr() as usize - ptr as usize) / 2);
  96         }
  97         if start[2] == needle {
  98             return Some((start[2..].as_ptr() as usize - ptr as usize) / 2);
  99         }
 100         if start[3] == needle {
 101             return Some((start[3..].as_ptr() as usize - ptr as usize) / 2);
 102         }
 103         if start[4] == needle {
 104             return Some((start[4..].as_ptr() as usize - ptr as usize) / 2);
 105         }
 106         if start[5] == needle {
 107             return Some((start[5..].as_ptr() as usize - ptr as usize) / 2);
 108         }
 109         if start[6] == needle {
 110             return Some((start[6..].as_ptr() as usize - ptr as usize) / 2);
 111         }
 112         if start[7] == needle {
 113             return Some((start[7..].as_ptr() as usize - ptr as usize) / 2);
 114         }
 115
 116         start = &start[8..];
 117         len -= 8;
 118     }
 119
 120     for (i, c) in start.iter().enumerate() {
 121         if *c == needle {
 122             return Some((start.as_ptr() as usize - ptr as usize) / 2 + i);
 123         }
 124     }
 125     None
 126 }
 127
 128 pub fn to_u16s<S: AsRef<OsStr>>(s: S) -> crate::io::Result<Vec<u16>> {
 129     fn inner(s: &OsStr) -> crate::io::Result<Vec<u16>> {
 130         let mut maybe_result: Vec<u16> = s.encode_wide().collect();
 131         if unrolled_find_u16s(0, &maybe_result).is_some() {
 132             return Err(crate::io::Error::new(
 133                 ErrorKind::InvalidInput,
 134                 "strings passed to WinAPI cannot contain NULs",
 135             ));
 136         }
 137         maybe_result.push(0);
 138         Ok(maybe_result)
 139     }
 140     inner(s.as_ref())
 141 }
 142
 143 // Many Windows APIs follow a pattern of where we hand a buffer and then they
 144 // will report back to us how large the buffer should be or how many bytes
 145 // currently reside in the buffer. This function is an abstraction over these
 146 // functions by making them easier to call.
 147 //
 148 // The first callback, `f1`, is yielded a (pointer, len) pair which can be
 149 // passed to a syscall. The `ptr` is valid for `len` items (u16 in this case).
 150 // The closure is expected to return what the syscall returns which will be
 151 // interpreted by this function to determine if the syscall needs to be invoked
 152 // again (with more buffer space).
 153 //
 154 // Once the syscall has completed (errors bail out early) the second closure is
 155 // yielded the data which has been read from the syscall. The return value
 156 // from this closure is then the return value of the function.
 157 fn fill_utf16_buf<F1, F2, T>(mut f1: F1, f2: F2) -> crate::io::Result<T>
 158 where
 159     F1: FnMut(*mut u16, c::DWORD) -> c::DWORD,
 160     F2: FnOnce(&[u16]) -> T,
 161 {
 162     // Start off with a stack buf but then spill over to the heap if we end up
 163     // needing more space.
 164     let mut stack_buf = [0u16; 512];
 165     let mut heap_buf = Vec::new();
 166     unsafe {
 167         let mut n = stack_buf.len();
 168         loop {
 169             let buf = if n <= stack_buf.len() {
 170                 &mut stack_buf[..]
 171             } else {
 172                 let extra = n - heap_buf.len();
 173                 heap_buf.reserve(extra);
 174                 heap_buf.set_len(n);
 175                 &mut heap_buf[..]
 176             };
 177
 178             // This function is typically called on windows API functions which
 179             // will return the correct length of the string, but these functions
 180             // also return the `0` on error. In some cases, however, the
 181             // returned "correct length" may actually be 0!
 182             //
 183             // To handle this case we call `SetLastError` to reset it to 0 and
 184             // then check it again if we get the "0 error value". If the "last
 185             // error" is still 0 then we interpret it as a 0 length buffer and
 186             // not an actual error.
 187             c::SetLastError(0);
 188             let k = match f1(buf.as_mut_ptr(), n as c::DWORD) {
 189                 0 if c::GetLastError() == 0 => 0,
 190                 0 => return Err(crate::io::Error::last_os_error()),
 191                 n => n,
 192             } as usize;
 193             if k == n && c::GetLastError() == c::ERROR_INSUFFICIENT_BUFFER {
 194                 n *= 2;
 195             } else if k >= n {
 196                 n = k;
 197             } else {
 198                 return Ok(f2(&buf[..k]));
 199             }
 200         }
 201     }
 202 }
 203
 204 fn os2path(s: &[u16]) -> PathBuf {
 205     PathBuf::from(OsString::from_wide(s))
 206 }
 207
 208 #[allow(dead_code)] // Only used in backtrace::gnu::get_executable_filename()
 209 fn wide_char_to_multi_byte(
 210     code_page: u32,
 211     flags: u32,
 212     s: &[u16],
 213     no_default_char: bool,
 214 ) -> crate::io::Result<Vec<i8>> {
 215     unsafe {
 216         let mut size = c::WideCharToMultiByte(
 217             code_page,
 218             flags,
 219             s.as_ptr(),
 220             s.len() as i32,
 221             ptr::null_mut(),
 222             0,
 223             ptr::null(),
 224             ptr::null_mut(),
 225         );
 226         if size == 0 {
 227             return Err(crate::io::Error::last_os_error());
 228         }
 229
 230         let mut buf = Vec::with_capacity(size as usize);
 231         buf.set_len(size as usize);
 232
 233         let mut used_default_char = c::FALSE;
 234         size = c::WideCharToMultiByte(
 235             code_page,
 236             flags,
 237             s.as_ptr(),
 238             s.len() as i32,
 239             buf.as_mut_ptr(),
 240             buf.len() as i32,
 241             ptr::null(),
 242             if no_default_char { &mut used_default_char } else { ptr::null_mut() },
 243         );
 244         if size == 0 {
 245             return Err(crate::io::Error::last_os_error());
 246         }
 247         if no_default_char && used_default_char == c::TRUE {
 248             return Err(crate::io::Error::new(
 249                 crate::io::ErrorKind::InvalidData,
 250                 "string cannot be converted to requested code page",
 251             ));
 252         }
 253
 254         buf.set_len(size as usize);
 255
 256         Ok(buf)
 257     }
 258 }
 259
 260 pub fn truncate_utf16_at_nul(v: &[u16]) -> &[u16] {
 261     match unrolled_find_u16s(0, v) {
 262         // don't include the 0
 263         Some(i) => &v[..i],
 264         None => v,
 265     }
 266 }
 267
 268 pub trait IsZero {
 269     fn is_zero(&self) -> bool;
 270 }
 271
 272 macro_rules! impl_is_zero {
 273     ($($t:ident)*) => ($(impl IsZero for $t {
 274         fn is_zero(&self) -> bool {
 275             *self == 0
 276         }
 277     })*)
 278 }
 279
 280 impl_is_zero! { i8 i16 i32 i64 isize u8 u16 u32 u64 usize }
 281
 282 pub fn cvt<I: IsZero>(i: I) -> crate::io::Result<I> {
 283     if i.is_zero() { Err(crate::io::Error::last_os_error()) } else { Ok(i) }
 284 }
 285
 286 pub fn dur2timeout(dur: Duration) -> c::DWORD {
 287     // Note that a duration is a (u64, u32) (seconds, nanoseconds) pair, and the
 288     // timeouts in windows APIs are typically u32 milliseconds. To translate, we
 289     // have two pieces to take care of:
 290     //
 291     // * Nanosecond precision is rounded up
 292     // * Greater than u32::MAX milliseconds (50 days) is rounded up to INFINITE
 293     //   (never time out).
 294     dur.as_secs()
 295         .checked_mul(1000)
 296         .and_then(|ms| ms.checked_add((dur.subsec_nanos() as u64) / 1_000_000))
 297         .and_then(|ms| ms.checked_add(if dur.subsec_nanos() % 1_000_000 > 0 { 1 } else { 0 }))
 298         .map(|ms| if ms > <c::DWORD>::max_value() as u64 { c::INFINITE } else { ms as c::DWORD })
 299         .unwrap_or(c::INFINITE)
 300 }
 301
 302 // On Windows, use the processor-specific __fastfail mechanism.  In Windows 8
 303 // and later, this will terminate the process immediately without running any
 304 // in-process exception handlers.  In earlier versions of Windows, this
 305 // sequence of instructions will be treated as an access violation,
 306 // terminating the process but without necessarily bypassing all exception
 307 // handlers.
 308 //
 309 // https://docs.microsoft.com/en-us/cpp/intrinsics/fastfail
 310 #[allow(unreachable_code)]
 311 pub unsafe fn abort_internal() -> ! {
 312     #[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
 313     {
 314         llvm_asm!("int $$0x29" :: "{ecx}"(7) ::: volatile); // 7 is FAST_FAIL_FATAL_APP_EXIT
 315         crate::intrinsics::unreachable();
 316     }
 317     crate::intrinsics::abort();
 318 }