Rollup merge of #135696 - joboet:move_pal_io, r=Noratrieb

std: move `io` module out of `pal`, get rid of `sys_common::io`

Part of #117276.

This does two related things:
1. It moves the platform-specific definitions for `IoSlice`, `IoSliceMut` and `is_terminal` out of `pal` and into `sys` and unifies some of them.
2. It gets rid of `sys_common::io`, moving the non-platform-specific test helpers into `std::test_helpers` and the buffer size definition to the new `sys::io` module.

1 files changed, 0 insertions, 153 deletions

diff --git a/library/std/src/sys/pal/windows/io.rs b/library/std/src/sys/pal/windows/io.rs
deleted file mode 100644
index f2865d2ffc1..00000000000
--- a/library/std/src/sys/pal/windows/io.rs
+++ /dev/null
@@ -1,153 +0,0 @@
-use core::ffi::c_void;
-
-use crate::marker::PhantomData;
-use crate::mem::size_of;
-use crate::os::windows::io::{AsHandle, AsRawHandle, BorrowedHandle};
-use crate::slice;
-use crate::sys::c;
-
-#[derive(Copy, Clone)]
-#[repr(transparent)]
-pub struct IoSlice<'a> {
-    vec: c::WSABUF,
-    _p: PhantomData<&'a [u8]>,
-}
-
-impl<'a> IoSlice<'a> {
-    #[inline]
-    pub fn new(buf: &'a [u8]) -> IoSlice<'a> {
-        assert!(buf.len() <= u32::MAX as usize);
-        IoSlice {
-            vec: c::WSABUF { len: buf.len() as u32, buf: buf.as_ptr() as *mut u8 },
-            _p: PhantomData,
-        }
-    }
-
-    #[inline]
-    pub fn advance(&mut self, n: usize) {
-        if (self.vec.len as usize) < n {
-            panic!("advancing IoSlice beyond its length");
-        }
-
-        unsafe {
-            self.vec.len -= n as u32;
-            self.vec.buf = self.vec.buf.add(n);
-        }
-    }
-
-    #[inline]
-    pub const fn as_slice(&self) -> &'a [u8] {
-        unsafe { slice::from_raw_parts(self.vec.buf, self.vec.len as usize) }
-    }
-}
-
-#[repr(transparent)]
-pub struct IoSliceMut<'a> {
-    vec: c::WSABUF,
-    _p: PhantomData<&'a mut [u8]>,
-}
-
-impl<'a> IoSliceMut<'a> {
-    #[inline]
-    pub fn new(buf: &'a mut [u8]) -> IoSliceMut<'a> {
-        assert!(buf.len() <= u32::MAX as usize);
-        IoSliceMut {
-            vec: c::WSABUF { len: buf.len() as u32, buf: buf.as_mut_ptr() },
-            _p: PhantomData,
-        }
-    }
-
-    #[inline]
-    pub fn advance(&mut self, n: usize) {
-        if (self.vec.len as usize) < n {
-            panic!("advancing IoSliceMut beyond its length");
-        }
-
-        unsafe {
-            self.vec.len -= n as u32;
-            self.vec.buf = self.vec.buf.add(n);
-        }
-    }
-
-    #[inline]
-    pub fn as_slice(&self) -> &[u8] {
-        unsafe { slice::from_raw_parts(self.vec.buf, self.vec.len as usize) }
-    }
-
-    #[inline]
-    pub const fn into_slice(self) -> &'a mut [u8] {
-        unsafe { slice::from_raw_parts_mut(self.vec.buf, self.vec.len as usize) }
-    }
-
-    #[inline]
-    pub fn as_mut_slice(&mut self) -> &mut [u8] {
-        unsafe { slice::from_raw_parts_mut(self.vec.buf, self.vec.len as usize) }
-    }
-}
-
-pub fn is_terminal(h: &impl AsHandle) -> bool {
-    handle_is_console(h.as_handle())
-}
-
-fn handle_is_console(handle: BorrowedHandle<'_>) -> bool {
-    // A null handle means the process has no console.
-    if handle.as_raw_handle().is_null() {
-        return false;
-    }
-
-    let mut out = 0;
-    if unsafe { c::GetConsoleMode(handle.as_raw_handle(), &mut out) != 0 } {
-        // False positives aren't possible. If we got a console then we definitely have a console.
-        return true;
-    }
-
-    // Otherwise, we fall back to an msys hack to see if we can detect the presence of a pty.
-    msys_tty_on(handle)
-}
-
-fn msys_tty_on(handle: BorrowedHandle<'_>) -> bool {
-    // Early return if the handle is not a pipe.
-    if unsafe { c::GetFileType(handle.as_raw_handle()) != c::FILE_TYPE_PIPE } {
-        return false;
-    }
-
-    /// Mirrors [`FILE_NAME_INFO`], giving it a fixed length that we can stack
-    /// allocate
-    ///
-    /// [`FILE_NAME_INFO`]: https://learn.microsoft.com/en-us/windows/win32/api/winbase/ns-winbase-file_name_info
-    #[repr(C)]
-    #[allow(non_snake_case)]
-    struct FILE_NAME_INFO {
-        FileNameLength: u32,
-        FileName: [u16; c::MAX_PATH as usize],
-    }
-    let mut name_info = FILE_NAME_INFO { FileNameLength: 0, FileName: [0; c::MAX_PATH as usize] };
-    // Safety: buffer length is fixed.
-    let res = unsafe {
-        c::GetFileInformationByHandleEx(
-            handle.as_raw_handle(),
-            c::FileNameInfo,
-            (&raw mut name_info) as *mut c_void,
-            size_of::<FILE_NAME_INFO>() as u32,
-        )
-    };
-    if res == 0 {
-        return false;
-    }
-
-    // Use `get` because `FileNameLength` can be out of range.
-    let s = match name_info.FileName.get(..name_info.FileNameLength as usize / 2) {
-        None => return false,
-        Some(s) => s,
-    };
-    let name = String::from_utf16_lossy(s);
-    // Get the file name only.
-    let name = name.rsplit('\\').next().unwrap_or(&name);
-    // This checks whether 'pty' exists in the file name, which indicates that
-    // a pseudo-terminal is attached. To mitigate against false positives
-    // (e.g., an actual file name that contains 'pty'), we also require that
-    // the file name begins with either the strings 'msys-' or 'cygwin-'.)
-    let is_msys = name.starts_with("msys-") || name.starts_with("cygwin-");
-    let is_pty = name.contains("-pty");
-    is_msys && is_pty
-}