Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1042 insertions, 0 deletions

diff --git a/library/std/src/io/stdio.rs b/library/std/src/io/stdio.rs
new file mode 100644
index 000000000..4d3736f79
--- /dev/null
+++ b/library/std/src/io/stdio.rs
@@ -0,0 +1,1042 @@
+#![cfg_attr(test, allow(unused))]
+
+#[cfg(test)]
+mod tests;
+
+use crate::io::prelude::*;
+
+use crate::cell::{Cell, RefCell};
+use crate::fmt;
+use crate::io::{self, BufReader, IoSlice, IoSliceMut, LineWriter, Lines};
+use crate::pin::Pin;
+use crate::sync::atomic::{AtomicBool, Ordering};
+use crate::sync::{Arc, Mutex, MutexGuard, OnceLock};
+use crate::sys::stdio;
+use crate::sys_common::remutex::{ReentrantMutex, ReentrantMutexGuard};
+
+type LocalStream = Arc<Mutex<Vec<u8>>>;
+
+thread_local! {
+    /// Used by the test crate to capture the output of the print macros and panics.
+    static OUTPUT_CAPTURE: Cell<Option<LocalStream>> = {
+        Cell::new(None)
+    }
+}
+
+/// Flag to indicate OUTPUT_CAPTURE is used.
+///
+/// If it is None and was never set on any thread, this flag is set to false,
+/// and OUTPUT_CAPTURE can be safely ignored on all threads, saving some time
+/// and memory registering an unused thread local.
+///
+/// Note about memory ordering: This contains information about whether a
+/// thread local variable might be in use. Although this is a global flag, the
+/// memory ordering between threads does not matter: we only want this flag to
+/// have a consistent order between set_output_capture and print_to *within
+/// the same thread*. Within the same thread, things always have a perfectly
+/// consistent order. So Ordering::Relaxed is fine.
+static OUTPUT_CAPTURE_USED: AtomicBool = AtomicBool::new(false);
+
+/// A handle to a raw instance of the standard input stream of this process.
+///
+/// This handle is not synchronized or buffered in any fashion. Constructed via
+/// the `std::io::stdio::stdin_raw` function.
+struct StdinRaw(stdio::Stdin);
+
+/// A handle to a raw instance of the standard output stream of this process.
+///
+/// This handle is not synchronized or buffered in any fashion. Constructed via
+/// the `std::io::stdio::stdout_raw` function.
+struct StdoutRaw(stdio::Stdout);
+
+/// A handle to a raw instance of the standard output stream of this process.
+///
+/// This handle is not synchronized or buffered in any fashion. Constructed via
+/// the `std::io::stdio::stderr_raw` function.
+struct StderrRaw(stdio::Stderr);
+
+/// Constructs a new raw handle to the standard input of this process.
+///
+/// The returned handle does not interact with any other handles created nor
+/// handles returned by `std::io::stdin`. Data buffered by the `std::io::stdin`
+/// handles is **not** available to raw handles returned from this function.
+///
+/// The returned handle has no external synchronization or buffering.
+#[unstable(feature = "libstd_sys_internals", issue = "none")]
+const fn stdin_raw() -> StdinRaw {
+    StdinRaw(stdio::Stdin::new())
+}
+
+/// Constructs a new raw handle to the standard output stream of this process.
+///
+/// The returned handle does not interact with any other handles created nor
+/// handles returned by `std::io::stdout`. Note that data is buffered by the
+/// `std::io::stdout` handles so writes which happen via this raw handle may
+/// appear before previous writes.
+///
+/// The returned handle has no external synchronization or buffering layered on
+/// top.
+#[unstable(feature = "libstd_sys_internals", issue = "none")]
+const fn stdout_raw() -> StdoutRaw {
+    StdoutRaw(stdio::Stdout::new())
+}
+
+/// Constructs a new raw handle to the standard error stream of this process.
+///
+/// The returned handle does not interact with any other handles created nor
+/// handles returned by `std::io::stderr`.
+///
+/// The returned handle has no external synchronization or buffering layered on
+/// top.
+#[unstable(feature = "libstd_sys_internals", issue = "none")]
+const fn stderr_raw() -> StderrRaw {
+    StderrRaw(stdio::Stderr::new())
+}
+
+impl Read for StdinRaw {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        handle_ebadf(self.0.read(buf), 0)
+    }
+
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
+        handle_ebadf(self.0.read_vectored(bufs), 0)
+    }
+
+    #[inline]
+    fn is_read_vectored(&self) -> bool {
+        self.0.is_read_vectored()
+    }
+
+    fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
+        handle_ebadf(self.0.read_to_end(buf), 0)
+    }
+
+    fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
+        handle_ebadf(self.0.read_to_string(buf), 0)
+    }
+}
+
+impl Write for StdoutRaw {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        handle_ebadf(self.0.write(buf), buf.len())
+    }
+
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+        let total = bufs.iter().map(|b| b.len()).sum();
+        handle_ebadf(self.0.write_vectored(bufs), total)
+    }
+
+    #[inline]
+    fn is_write_vectored(&self) -> bool {
+        self.0.is_write_vectored()
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        handle_ebadf(self.0.flush(), ())
+    }
+
+    fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
+        handle_ebadf(self.0.write_all(buf), ())
+    }
+
+    fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> io::Result<()> {
+        handle_ebadf(self.0.write_all_vectored(bufs), ())
+    }
+
+    fn write_fmt(&mut self, fmt: fmt::Arguments<'_>) -> io::Result<()> {
+        handle_ebadf(self.0.write_fmt(fmt), ())
+    }
+}
+
+impl Write for StderrRaw {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        handle_ebadf(self.0.write(buf), buf.len())
+    }
+
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+        let total = bufs.iter().map(|b| b.len()).sum();
+        handle_ebadf(self.0.write_vectored(bufs), total)
+    }
+
+    #[inline]
+    fn is_write_vectored(&self) -> bool {
+        self.0.is_write_vectored()
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        handle_ebadf(self.0.flush(), ())
+    }
+
+    fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
+        handle_ebadf(self.0.write_all(buf), ())
+    }
+
+    fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> io::Result<()> {
+        handle_ebadf(self.0.write_all_vectored(bufs), ())
+    }
+
+    fn write_fmt(&mut self, fmt: fmt::Arguments<'_>) -> io::Result<()> {
+        handle_ebadf(self.0.write_fmt(fmt), ())
+    }
+}
+
+fn handle_ebadf<T>(r: io::Result<T>, default: T) -> io::Result<T> {
+    match r {
+        Err(ref e) if stdio::is_ebadf(e) => Ok(default),
+        r => r,
+    }
+}
+
+/// A handle to the standard input stream of a process.
+///
+/// Each handle is a shared reference to a global buffer of input data to this
+/// process. A handle can be `lock`'d to gain full access to [`BufRead`] methods
+/// (e.g., `.lines()`). Reads to this handle are otherwise locked with respect
+/// to other reads.
+///
+/// This handle implements the `Read` trait, but beware that concurrent reads
+/// of `Stdin` must be executed with care.
+///
+/// Created by the [`io::stdin`] method.
+///
+/// [`io::stdin`]: stdin
+///
+/// ### Note: Windows Portability Considerations
+///
+/// When operating in a console, the Windows implementation of this stream does not support
+/// non-UTF-8 byte sequences. Attempting to read bytes that are not valid UTF-8 will return
+/// an error.
+///
+/// In a process with a detached console, such as one using
+/// `#![windows_subsystem = "windows"]`, or in a child process spawned from such a process,
+/// the contained handle will be null. In such cases, the standard library's `Read` and
+/// `Write` will do nothing and silently succeed. All other I/O operations, via the
+/// standard library or via raw Windows API calls, will fail.
+///
+/// # Examples
+///
+/// ```no_run
+/// use std::io;
+///
+/// fn main() -> io::Result<()> {
+///     let mut buffer = String::new();
+///     let stdin = io::stdin(); // We get `Stdin` here.
+///     stdin.read_line(&mut buffer)?;
+///     Ok(())
+/// }
+/// ```
+#[stable(feature = "rust1", since = "1.0.0")]
+pub struct Stdin {
+    inner: &'static Mutex<BufReader<StdinRaw>>,
+}
+
+/// A locked reference to the [`Stdin`] handle.
+///
+/// This handle implements both the [`Read`] and [`BufRead`] traits, and
+/// is constructed via the [`Stdin::lock`] method.
+///
+/// ### Note: Windows Portability Considerations
+///
+/// When operating in a console, the Windows implementation of this stream does not support
+/// non-UTF-8 byte sequences. Attempting to read bytes that are not valid UTF-8 will return
+/// an error.
+///
+/// In a process with a detached console, such as one using
+/// `#![windows_subsystem = "windows"]`, or in a child process spawned from such a process,
+/// the contained handle will be null. In such cases, the standard library's `Read` and
+/// `Write` will do nothing and silently succeed. All other I/O operations, via the
+/// standard library or via raw Windows API calls, will fail.
+///
+/// # Examples
+///
+/// ```no_run
+/// use std::io::{self, BufRead};
+///
+/// fn main() -> io::Result<()> {
+///     let mut buffer = String::new();
+///     let stdin = io::stdin(); // We get `Stdin` here.
+///     {
+///         let mut handle = stdin.lock(); // We get `StdinLock` here.
+///         handle.read_line(&mut buffer)?;
+///     } // `StdinLock` is dropped here.
+///     Ok(())
+/// }
+/// ```
+#[must_use = "if unused stdin will immediately unlock"]
+#[stable(feature = "rust1", since = "1.0.0")]
+pub struct StdinLock<'a> {
+    inner: MutexGuard<'a, BufReader<StdinRaw>>,
+}
+
+/// Constructs a new handle to the standard input of the current process.
+///
+/// Each handle returned is a reference to a shared global buffer whose access
+/// is synchronized via a mutex. If you need more explicit control over
+/// locking, see the [`Stdin::lock`] method.
+///
+/// ### Note: Windows Portability Considerations
+///
+/// When operating in a console, the Windows implementation of this stream does not support
+/// non-UTF-8 byte sequences. Attempting to read bytes that are not valid UTF-8 will return
+/// an error.
+///
+/// In a process with a detached console, such as one using
+/// `#![windows_subsystem = "windows"]`, or in a child process spawned from such a process,
+/// the contained handle will be null. In such cases, the standard library's `Read` and
+/// `Write` will do nothing and silently succeed. All other I/O operations, via the
+/// standard library or via raw Windows API calls, will fail.
+///
+/// # Examples
+///
+/// Using implicit synchronization:
+///
+/// ```no_run
+/// use std::io;
+///
+/// fn main() -> io::Result<()> {
+///     let mut buffer = String::new();
+///     io::stdin().read_line(&mut buffer)?;
+///     Ok(())
+/// }
+/// ```
+///
+/// Using explicit synchronization:
+///
+/// ```no_run
+/// use std::io::{self, BufRead};
+///
+/// fn main() -> io::Result<()> {
+///     let mut buffer = String::new();
+///     let stdin = io::stdin();
+///     let mut handle = stdin.lock();
+///
+///     handle.read_line(&mut buffer)?;
+///     Ok(())
+/// }
+/// ```
+#[must_use]
+#[stable(feature = "rust1", since = "1.0.0")]
+pub fn stdin() -> Stdin {
+    static INSTANCE: OnceLock<Mutex<BufReader<StdinRaw>>> = OnceLock::new();
+    Stdin {
+        inner: INSTANCE.get_or_init(|| {
+            Mutex::new(BufReader::with_capacity(stdio::STDIN_BUF_SIZE, stdin_raw()))
+        }),
+    }
+}
+
+impl Stdin {
+    /// Locks this handle to the standard input stream, returning a readable
+    /// guard.
+    ///
+    /// The lock is released when the returned lock goes out of scope. The
+    /// returned guard also implements the [`Read`] and [`BufRead`] traits for
+    /// accessing the underlying data.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io::{self, BufRead};
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let mut buffer = String::new();
+    ///     let stdin = io::stdin();
+    ///     let mut handle = stdin.lock();
+    ///
+    ///     handle.read_line(&mut buffer)?;
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn lock(&self) -> StdinLock<'static> {
+        // Locks this handle with 'static lifetime. This depends on the
+        // implementation detail that the underlying `Mutex` is static.
+        StdinLock { inner: self.inner.lock().unwrap_or_else(|e| e.into_inner()) }
+    }
+
+    /// Locks this handle and reads a line of input, appending it to the specified buffer.
+    ///
+    /// For detailed semantics of this method, see the documentation on
+    /// [`BufRead::read_line`].
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    ///
+    /// let mut input = String::new();
+    /// match io::stdin().read_line(&mut input) {
+    ///     Ok(n) => {
+    ///         println!("{n} bytes read");
+    ///         println!("{input}");
+    ///     }
+    ///     Err(error) => println!("error: {error}"),
+    /// }
+    /// ```
+    ///
+    /// You can run the example one of two ways:
+    ///
+    /// - Pipe some text to it, e.g., `printf foo | path/to/executable`
+    /// - Give it text interactively by running the executable directly,
+    ///   in which case it will wait for the Enter key to be pressed before
+    ///   continuing
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn read_line(&self, buf: &mut String) -> io::Result<usize> {
+        self.lock().read_line(buf)
+    }
+
+    /// Consumes this handle and returns an iterator over input lines.
+    ///
+    /// For detailed semantics of this method, see the documentation on
+    /// [`BufRead::lines`].
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    ///
+    /// let lines = io::stdin().lines();
+    /// for line in lines {
+    ///     println!("got a line: {}", line.unwrap());
+    /// }
+    /// ```
+    #[must_use = "`self` will be dropped if the result is not used"]
+    #[stable(feature = "stdin_forwarders", since = "1.62.0")]
+    pub fn lines(self) -> Lines<StdinLock<'static>> {
+        self.lock().lines()
+    }
+}
+
+#[stable(feature = "std_debug", since = "1.16.0")]
+impl fmt::Debug for Stdin {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Stdin").finish_non_exhaustive()
+    }
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl Read for Stdin {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.lock().read(buf)
+    }
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
+        self.lock().read_vectored(bufs)
+    }
+    #[inline]
+    fn is_read_vectored(&self) -> bool {
+        self.lock().is_read_vectored()
+    }
+    fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
+        self.lock().read_to_end(buf)
+    }
+    fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
+        self.lock().read_to_string(buf)
+    }
+    fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
+        self.lock().read_exact(buf)
+    }
+}
+
+// only used by platform-dependent io::copy specializations, i.e. unused on some platforms
+#[cfg(any(target_os = "linux", target_os = "android"))]
+impl StdinLock<'_> {
+    pub(crate) fn as_mut_buf(&mut self) -> &mut BufReader<impl Read> {
+        &mut self.inner
+    }
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl Read for StdinLock<'_> {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.inner.read(buf)
+    }
+
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
+        self.inner.read_vectored(bufs)
+    }
+
+    #[inline]
+    fn is_read_vectored(&self) -> bool {
+        self.inner.is_read_vectored()
+    }
+
+    fn read_to_end(&mut self, buf: &mut Vec<u8>) -> io::Result<usize> {
+        self.inner.read_to_end(buf)
+    }
+
+    fn read_to_string(&mut self, buf: &mut String) -> io::Result<usize> {
+        self.inner.read_to_string(buf)
+    }
+
+    fn read_exact(&mut self, buf: &mut [u8]) -> io::Result<()> {
+        self.inner.read_exact(buf)
+    }
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl BufRead for StdinLock<'_> {
+    fn fill_buf(&mut self) -> io::Result<&[u8]> {
+        self.inner.fill_buf()
+    }
+
+    fn consume(&mut self, n: usize) {
+        self.inner.consume(n)
+    }
+
+    fn read_until(&mut self, byte: u8, buf: &mut Vec<u8>) -> io::Result<usize> {
+        self.inner.read_until(byte, buf)
+    }
+
+    fn read_line(&mut self, buf: &mut String) -> io::Result<usize> {
+        self.inner.read_line(buf)
+    }
+}
+
+#[stable(feature = "std_debug", since = "1.16.0")]
+impl fmt::Debug for StdinLock<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("StdinLock").finish_non_exhaustive()
+    }
+}
+
+/// A handle to the global standard output stream of the current process.
+///
+/// Each handle shares a global buffer of data to be written to the standard
+/// output stream. Access is also synchronized via a lock and explicit control
+/// over locking is available via the [`lock`] method.
+///
+/// Created by the [`io::stdout`] method.
+///
+/// ### Note: Windows Portability Considerations
+///
+/// When operating in a console, the Windows implementation of this stream does not support
+/// non-UTF-8 byte sequences. Attempting to write bytes that are not valid UTF-8 will return
+/// an error.
+///
+/// In a process with a detached console, such as one using
+/// `#![windows_subsystem = "windows"]`, or in a child process spawned from such a process,
+/// the contained handle will be null. In such cases, the standard library's `Read` and
+/// `Write` will do nothing and silently succeed. All other I/O operations, via the
+/// standard library or via raw Windows API calls, will fail.
+///
+/// [`lock`]: Stdout::lock
+/// [`io::stdout`]: stdout
+#[stable(feature = "rust1", since = "1.0.0")]
+pub struct Stdout {
+    // FIXME: this should be LineWriter or BufWriter depending on the state of
+    //        stdout (tty or not). Note that if this is not line buffered it
+    //        should also flush-on-panic or some form of flush-on-abort.
+    inner: Pin<&'static ReentrantMutex<RefCell<LineWriter<StdoutRaw>>>>,
+}
+
+/// A locked reference to the [`Stdout`] handle.
+///
+/// This handle implements the [`Write`] trait, and is constructed via
+/// the [`Stdout::lock`] method. See its documentation for more.
+///
+/// ### Note: Windows Portability Considerations
+///
+/// When operating in a console, the Windows implementation of this stream does not support
+/// non-UTF-8 byte sequences. Attempting to write bytes that are not valid UTF-8 will return
+/// an error.
+///
+/// In a process with a detached console, such as one using
+/// `#![windows_subsystem = "windows"]`, or in a child process spawned from such a process,
+/// the contained handle will be null. In such cases, the standard library's `Read` and
+/// `Write` will do nothing and silently succeed. All other I/O operations, via the
+/// standard library or via raw Windows API calls, will fail.
+#[must_use = "if unused stdout will immediately unlock"]
+#[stable(feature = "rust1", since = "1.0.0")]
+pub struct StdoutLock<'a> {
+    inner: ReentrantMutexGuard<'a, RefCell<LineWriter<StdoutRaw>>>,
+}
+
+static STDOUT: OnceLock<ReentrantMutex<RefCell<LineWriter<StdoutRaw>>>> = OnceLock::new();
+
+/// Constructs a new handle to the standard output of the current process.
+///
+/// Each handle returned is a reference to a shared global buffer whose access
+/// is synchronized via a mutex. If you need more explicit control over
+/// locking, see the [`Stdout::lock`] method.
+///
+/// ### Note: Windows Portability Considerations
+///
+/// When operating in a console, the Windows implementation of this stream does not support
+/// non-UTF-8 byte sequences. Attempting to write bytes that are not valid UTF-8 will return
+/// an error.
+///
+/// In a process with a detached console, such as one using
+/// `#![windows_subsystem = "windows"]`, or in a child process spawned from such a process,
+/// the contained handle will be null. In such cases, the standard library's `Read` and
+/// `Write` will do nothing and silently succeed. All other I/O operations, via the
+/// standard library or via raw Windows API calls, will fail.
+///
+/// # Examples
+///
+/// Using implicit synchronization:
+///
+/// ```no_run
+/// use std::io::{self, Write};
+///
+/// fn main() -> io::Result<()> {
+///     io::stdout().write_all(b"hello world")?;
+///
+///     Ok(())
+/// }
+/// ```
+///
+/// Using explicit synchronization:
+///
+/// ```no_run
+/// use std::io::{self, Write};
+///
+/// fn main() -> io::Result<()> {
+///     let stdout = io::stdout();
+///     let mut handle = stdout.lock();
+///
+///     handle.write_all(b"hello world")?;
+///
+///     Ok(())
+/// }
+/// ```
+#[must_use]
+#[stable(feature = "rust1", since = "1.0.0")]
+pub fn stdout() -> Stdout {
+    Stdout {
+        inner: Pin::static_ref(&STDOUT).get_or_init_pin(
+            || unsafe { ReentrantMutex::new(RefCell::new(LineWriter::new(stdout_raw()))) },
+            |mutex| unsafe { mutex.init() },
+        ),
+    }
+}
+
+pub fn cleanup() {
+    if let Some(instance) = STDOUT.get() {
+        // Flush the data and disable buffering during shutdown
+        // by replacing the line writer by one with zero
+        // buffering capacity.
+        // We use try_lock() instead of lock(), because someone
+        // might have leaked a StdoutLock, which would
+        // otherwise cause a deadlock here.
+        if let Some(lock) = Pin::static_ref(instance).try_lock() {
+            *lock.borrow_mut() = LineWriter::with_capacity(0, stdout_raw());
+        }
+    }
+}
+
+impl Stdout {
+    /// Locks this handle to the standard output stream, returning a writable
+    /// guard.
+    ///
+    /// The lock is released when the returned lock goes out of scope. The
+    /// returned guard also implements the `Write` trait for writing data.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io::{self, Write};
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let mut stdout = io::stdout().lock();
+    ///
+    ///     stdout.write_all(b"hello world")?;
+    ///
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn lock(&self) -> StdoutLock<'static> {
+        // Locks this handle with 'static lifetime. This depends on the
+        // implementation detail that the underlying `ReentrantMutex` is
+        // static.
+        StdoutLock { inner: self.inner.lock() }
+    }
+}
+
+#[stable(feature = "std_debug", since = "1.16.0")]
+impl fmt::Debug for Stdout {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Stdout").finish_non_exhaustive()
+    }
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl Write for Stdout {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        (&*self).write(buf)
+    }
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+        (&*self).write_vectored(bufs)
+    }
+    #[inline]
+    fn is_write_vectored(&self) -> bool {
+        io::Write::is_write_vectored(&&*self)
+    }
+    fn flush(&mut self) -> io::Result<()> {
+        (&*self).flush()
+    }
+    fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
+        (&*self).write_all(buf)
+    }
+    fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> io::Result<()> {
+        (&*self).write_all_vectored(bufs)
+    }
+    fn write_fmt(&mut self, args: fmt::Arguments<'_>) -> io::Result<()> {
+        (&*self).write_fmt(args)
+    }
+}
+
+#[stable(feature = "write_mt", since = "1.48.0")]
+impl Write for &Stdout {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.lock().write(buf)
+    }
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+        self.lock().write_vectored(bufs)
+    }
+    #[inline]
+    fn is_write_vectored(&self) -> bool {
+        self.lock().is_write_vectored()
+    }
+    fn flush(&mut self) -> io::Result<()> {
+        self.lock().flush()
+    }
+    fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
+        self.lock().write_all(buf)
+    }
+    fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> io::Result<()> {
+        self.lock().write_all_vectored(bufs)
+    }
+    fn write_fmt(&mut self, args: fmt::Arguments<'_>) -> io::Result<()> {
+        self.lock().write_fmt(args)
+    }
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl Write for StdoutLock<'_> {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.inner.borrow_mut().write(buf)
+    }
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+        self.inner.borrow_mut().write_vectored(bufs)
+    }
+    #[inline]
+    fn is_write_vectored(&self) -> bool {
+        self.inner.borrow_mut().is_write_vectored()
+    }
+    fn flush(&mut self) -> io::Result<()> {
+        self.inner.borrow_mut().flush()
+    }
+    fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
+        self.inner.borrow_mut().write_all(buf)
+    }
+    fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> io::Result<()> {
+        self.inner.borrow_mut().write_all_vectored(bufs)
+    }
+}
+
+#[stable(feature = "std_debug", since = "1.16.0")]
+impl fmt::Debug for StdoutLock<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("StdoutLock").finish_non_exhaustive()
+    }
+}
+
+/// A handle to the standard error stream of a process.
+///
+/// For more information, see the [`io::stderr`] method.
+///
+/// [`io::stderr`]: stderr
+///
+/// ### Note: Windows Portability Considerations
+///
+/// When operating in a console, the Windows implementation of this stream does not support
+/// non-UTF-8 byte sequences. Attempting to write bytes that are not valid UTF-8 will return
+/// an error.
+///
+/// In a process with a detached console, such as one using
+/// `#![windows_subsystem = "windows"]`, or in a child process spawned from such a process,
+/// the contained handle will be null. In such cases, the standard library's `Read` and
+/// `Write` will do nothing and silently succeed. All other I/O operations, via the
+/// standard library or via raw Windows API calls, will fail.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub struct Stderr {
+    inner: Pin<&'static ReentrantMutex<RefCell<StderrRaw>>>,
+}
+
+/// A locked reference to the [`Stderr`] handle.
+///
+/// This handle implements the [`Write`] trait and is constructed via
+/// the [`Stderr::lock`] method. See its documentation for more.
+///
+/// ### Note: Windows Portability Considerations
+///
+/// When operating in a console, the Windows implementation of this stream does not support
+/// non-UTF-8 byte sequences. Attempting to write bytes that are not valid UTF-8 will return
+/// an error.
+///
+/// In a process with a detached console, such as one using
+/// `#![windows_subsystem = "windows"]`, or in a child process spawned from such a process,
+/// the contained handle will be null. In such cases, the standard library's `Read` and
+/// `Write` will do nothing and silently succeed. All other I/O operations, via the
+/// standard library or via raw Windows API calls, will fail.
+#[must_use = "if unused stderr will immediately unlock"]
+#[stable(feature = "rust1", since = "1.0.0")]
+pub struct StderrLock<'a> {
+    inner: ReentrantMutexGuard<'a, RefCell<StderrRaw>>,
+}
+
+/// Constructs a new handle to the standard error of the current process.
+///
+/// This handle is not buffered.
+///
+/// ### Note: Windows Portability Considerations
+///
+/// When operating in a console, the Windows implementation of this stream does not support
+/// non-UTF-8 byte sequences. Attempting to write bytes that are not valid UTF-8 will return
+/// an error.
+///
+/// In a process with a detached console, such as one using
+/// `#![windows_subsystem = "windows"]`, or in a child process spawned from such a process,
+/// the contained handle will be null. In such cases, the standard library's `Read` and
+/// `Write` will do nothing and silently succeed. All other I/O operations, via the
+/// standard library or via raw Windows API calls, will fail.
+///
+/// # Examples
+///
+/// Using implicit synchronization:
+///
+/// ```no_run
+/// use std::io::{self, Write};
+///
+/// fn main() -> io::Result<()> {
+///     io::stderr().write_all(b"hello world")?;
+///
+///     Ok(())
+/// }
+/// ```
+///
+/// Using explicit synchronization:
+///
+/// ```no_run
+/// use std::io::{self, Write};
+///
+/// fn main() -> io::Result<()> {
+///     let stderr = io::stderr();
+///     let mut handle = stderr.lock();
+///
+///     handle.write_all(b"hello world")?;
+///
+///     Ok(())
+/// }
+/// ```
+#[must_use]
+#[stable(feature = "rust1", since = "1.0.0")]
+pub fn stderr() -> Stderr {
+    // Note that unlike `stdout()` we don't use `at_exit` here to register a
+    // destructor. Stderr is not buffered , so there's no need to run a
+    // destructor for flushing the buffer
+    static INSTANCE: OnceLock<ReentrantMutex<RefCell<StderrRaw>>> = OnceLock::new();
+
+    Stderr {
+        inner: Pin::static_ref(&INSTANCE).get_or_init_pin(
+            || unsafe { ReentrantMutex::new(RefCell::new(stderr_raw())) },
+            |mutex| unsafe { mutex.init() },
+        ),
+    }
+}
+
+impl Stderr {
+    /// Locks this handle to the standard error stream, returning a writable
+    /// guard.
+    ///
+    /// The lock is released when the returned lock goes out of scope. The
+    /// returned guard also implements the [`Write`] trait for writing data.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::io::{self, Write};
+    ///
+    /// fn foo() -> io::Result<()> {
+    ///     let stderr = io::stderr();
+    ///     let mut handle = stderr.lock();
+    ///
+    ///     handle.write_all(b"hello world")?;
+    ///
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub fn lock(&self) -> StderrLock<'static> {
+        // Locks this handle with 'static lifetime. This depends on the
+        // implementation detail that the underlying `ReentrantMutex` is
+        // static.
+        StderrLock { inner: self.inner.lock() }
+    }
+}
+
+#[stable(feature = "std_debug", since = "1.16.0")]
+impl fmt::Debug for Stderr {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Stderr").finish_non_exhaustive()
+    }
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl Write for Stderr {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        (&*self).write(buf)
+    }
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+        (&*self).write_vectored(bufs)
+    }
+    #[inline]
+    fn is_write_vectored(&self) -> bool {
+        io::Write::is_write_vectored(&&*self)
+    }
+    fn flush(&mut self) -> io::Result<()> {
+        (&*self).flush()
+    }
+    fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
+        (&*self).write_all(buf)
+    }
+    fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> io::Result<()> {
+        (&*self).write_all_vectored(bufs)
+    }
+    fn write_fmt(&mut self, args: fmt::Arguments<'_>) -> io::Result<()> {
+        (&*self).write_fmt(args)
+    }
+}
+
+#[stable(feature = "write_mt", since = "1.48.0")]
+impl Write for &Stderr {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.lock().write(buf)
+    }
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+        self.lock().write_vectored(bufs)
+    }
+    #[inline]
+    fn is_write_vectored(&self) -> bool {
+        self.lock().is_write_vectored()
+    }
+    fn flush(&mut self) -> io::Result<()> {
+        self.lock().flush()
+    }
+    fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
+        self.lock().write_all(buf)
+    }
+    fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> io::Result<()> {
+        self.lock().write_all_vectored(bufs)
+    }
+    fn write_fmt(&mut self, args: fmt::Arguments<'_>) -> io::Result<()> {
+        self.lock().write_fmt(args)
+    }
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl Write for StderrLock<'_> {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.inner.borrow_mut().write(buf)
+    }
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+        self.inner.borrow_mut().write_vectored(bufs)
+    }
+    #[inline]
+    fn is_write_vectored(&self) -> bool {
+        self.inner.borrow_mut().is_write_vectored()
+    }
+    fn flush(&mut self) -> io::Result<()> {
+        self.inner.borrow_mut().flush()
+    }
+    fn write_all(&mut self, buf: &[u8]) -> io::Result<()> {
+        self.inner.borrow_mut().write_all(buf)
+    }
+    fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> io::Result<()> {
+        self.inner.borrow_mut().write_all_vectored(bufs)
+    }
+}
+
+#[stable(feature = "std_debug", since = "1.16.0")]
+impl fmt::Debug for StderrLock<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("StderrLock").finish_non_exhaustive()
+    }
+}
+
+/// Sets the thread-local output capture buffer and returns the old one.
+#[unstable(
+    feature = "internal_output_capture",
+    reason = "this function is meant for use in the test crate \
+        and may disappear in the future",
+    issue = "none"
+)]
+#[doc(hidden)]
+pub fn set_output_capture(sink: Option<LocalStream>) -> Option<LocalStream> {
+    if sink.is_none() && !OUTPUT_CAPTURE_USED.load(Ordering::Relaxed) {
+        // OUTPUT_CAPTURE is definitely None since OUTPUT_CAPTURE_USED is false.
+        return None;
+    }
+    OUTPUT_CAPTURE_USED.store(true, Ordering::Relaxed);
+    OUTPUT_CAPTURE.with(move |slot| slot.replace(sink))
+}
+
+/// Write `args` to the capture buffer if enabled and possible, or `global_s`
+/// otherwise. `label` identifies the stream in a panic message.
+///
+/// This function is used to print error messages, so it takes extra
+/// care to avoid causing a panic when `local_s` is unusable.
+/// For instance, if the TLS key for the local stream is
+/// already destroyed, or if the local stream is locked by another
+/// thread, it will just fall back to the global stream.
+///
+/// However, if the actual I/O causes an error, this function does panic.
+fn print_to<T>(args: fmt::Arguments<'_>, global_s: fn() -> T, label: &str)
+where
+    T: Write,
+{
+    if OUTPUT_CAPTURE_USED.load(Ordering::Relaxed)
+        && OUTPUT_CAPTURE.try_with(|s| {
+            // Note that we completely remove a local sink to write to in case
+            // our printing recursively panics/prints, so the recursive
+            // panic/print goes to the global sink instead of our local sink.
+            s.take().map(|w| {
+                let _ = w.lock().unwrap_or_else(|e| e.into_inner()).write_fmt(args);
+                s.set(Some(w));
+            })
+        }) == Ok(Some(()))
+    {
+        // Successfully wrote to capture buffer.
+        return;
+    }
+
+    if let Err(e) = global_s().write_fmt(args) {
+        panic!("failed printing to {label}: {e}");
+    }
+}
+
+#[unstable(
+    feature = "print_internals",
+    reason = "implementation detail which may disappear or be replaced at any time",
+    issue = "none"
+)]
+#[doc(hidden)]
+#[cfg(not(test))]
+pub fn _print(args: fmt::Arguments<'_>) {
+    print_to(args, stdout, "stdout");
+}
+
+#[unstable(
+    feature = "print_internals",
+    reason = "implementation detail which may disappear or be replaced at any time",
+    issue = "none"
+)]
+#[doc(hidden)]
+#[cfg(not(test))]
+pub fn _eprint(args: fmt::Arguments<'_>) {
+    print_to(args, stderr, "stderr");
+}
+
+#[cfg(test)]
+pub use realstd::io::{_eprint, _print};