Auto merge of rust-lang#127153 - NobodyXu:pipe, r=<try>

Initial implementation of anonymous_pipe API

ACP completed in rust-lang/libs-team#375
Tracking issue: rust-lang#127154

try-job: x86_64-msvc
try-job: i686-mingw

library/std/src/lib.rs

@@ -685,6 +685,9 @@ pub use core::{
     module_path, option_env, stringify, trace_macros,
 };
 
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+pub use crate::sys::anonymous_pipe as pipe;
+
 #[unstable(
     feature = "concat_bytes",
     issue = "87555",

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

@@ -0,0 +1,144 @@
+//! Module for anonymous pipe
+//!
+//! ```
+//! #![feature(anonymous_pipe)]
+//!
+//! # #[cfg(miri)] fn main() {}
+//! # #[cfg(not(miri))]
+//! # fn main() -> std::io::Result<()> {
+//! let (reader, writer) = std::pipe::pipe()?;
+//! # Ok(())
+//! # }
+//! ```
+
+use crate::{io, sys::pipe::AnonPipe};
+
+/// Create anonymous pipe that is close-on-exec and blocking.
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+#[inline]
+pub fn pipe() -> io::Result<(PipeReader, PipeWriter)> {
+    cfg_if::cfg_if! {
+        if #[cfg(unix)] {
+            unix::pipe()
+        } else if #[cfg(windows)] {
+            windows::pipe()
+        } else {
+            Err(io::Error::UNSUPPORTED_PLATFORM)
+        }
+    }
+}
+
+/// Read end of the anonymous pipe.
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+#[derive(Debug)]
+pub struct PipeReader(AnonPipe);
+
+/// Write end of the anonymous pipe.
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+#[derive(Debug)]
+pub struct PipeWriter(AnonPipe);
+
+impl PipeReader {
+    /// Create a new [`PipeReader`] instance that shares the same underlying file description.
+    #[unstable(feature = "anonymous_pipe", issue = "127154")]
+    pub fn try_clone(&self) -> io::Result<Self> {
+        self.0.try_clone().map(Self)
+    }
+}
+
+impl PipeWriter {
+    /// Create a new [`PipeWriter`] instance that shares the same underlying file description.
+    #[unstable(feature = "anonymous_pipe", issue = "127154")]
+    pub fn try_clone(&self) -> io::Result<Self> {
+        self.0.try_clone().map(Self)
+    }
+}
+
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl io::Read for &PipeReader {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.0.read(buf)
+    }
+    fn read_vectored(&mut self, bufs: &mut [io::IoSliceMut<'_>]) -> io::Result<usize> {
+        self.0.read_vectored(bufs)
+    }
+    #[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> {
+        self.0.read_to_end(buf)
+    }
+    fn read_buf(&mut self, buf: io::BorrowedCursor<'_>) -> io::Result<()> {
+        self.0.read_buf(buf)
+    }
+}
+
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl io::Read for PipeReader {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.0.read(buf)
+    }
+    fn read_vectored(&mut self, bufs: &mut [io::IoSliceMut<'_>]) -> io::Result<usize> {
+        self.0.read_vectored(bufs)
+    }
+    #[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> {
+        self.0.read_to_end(buf)
+    }
+    fn read_buf(&mut self, buf: io::BorrowedCursor<'_>) -> io::Result<()> {
+        self.0.read_buf(buf)
+    }
+}
+
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl io::Write for &PipeWriter {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.0.write(buf)
+    }
+    #[inline]
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+
+    fn write_vectored(&mut self, bufs: &[io::IoSlice<'_>]) -> io::Result<usize> {
+        self.0.write_vectored(bufs)
+    }
+
+    #[inline]
+    fn is_write_vectored(&self) -> bool {
+        self.0.is_write_vectored()
+    }
+}
+
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl io::Write for PipeWriter {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.0.write(buf)
+    }
+    #[inline]
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+
+    fn write_vectored(&mut self, bufs: &[io::IoSlice<'_>]) -> io::Result<usize> {
+        self.0.write_vectored(bufs)
+    }
+
+    #[inline]
+    fn is_write_vectored(&self) -> bool {
+        self.0.is_write_vectored()
+    }
+}
+
+#[cfg(unix)]
+mod unix;
+
+#[cfg(windows)]
+mod windows;
+
+#[cfg(all(test, not(miri)))]
+mod tests;

library/std/src/sys/anonymous_pipe/tests.rs

@@ -0,0 +1,42 @@
+use super::*;
+use crate::{
+    io::{Read, Write},
+    process,
+    thread::spawn,
+};
+
+#[test]
+fn pipe_creation_clone_and_rw() {
+    let (rx, tx) = pipe().unwrap();
+
+    let thread = spawn({
+        let mut tx = tx.try_clone().unwrap();
+        move || {
+            tx.write_all(b"12345").unwrap();
+            drop(tx);
+        }
+    });
+    drop(tx);
+
+    let mut rx2 = rx.try_clone().unwrap();
+    drop(rx);
+
+    let mut s = String::new();
+    rx2.read_to_string(&mut s).unwrap();
+    drop(rx2);
+    assert_eq!(s, "12345");
+
+    thread.join().unwrap();
+}
+
+#[test]
+fn subprocess() {
+    let (rx, tx) = pipe().unwrap();
+
+    assert!(process::Command::new("cargo").arg("--version").stdout(tx).status().unwrap().success());
+
+    let mut s = String::new();
+    (&rx).read_to_string(&mut s).unwrap();
+    drop(rx);
+    assert!(s.starts_with("cargo 1."));
+}

library/std/src/sys/anonymous_pipe/unix.rs

@@ -0,0 +1,108 @@
+use super::*;
+
+use crate::{
+    os::fd::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd},
+    process::Stdio,
+    sys::{
+        fd::FileDesc,
+        pipe::{anon_pipe, AnonPipe},
+    },
+    sys_common::{FromInner, IntoInner},
+};
+
+#[inline]
+pub(super) fn pipe() -> io::Result<(PipeReader, PipeWriter)> {
+    anon_pipe().map(|(rx, tx)| (PipeReader(rx), PipeWriter(tx)))
+}
+
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl AsFd for PipeReader {
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.0.as_fd()
+    }
+}
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl AsRawFd for PipeReader {
+    fn as_raw_fd(&self) -> RawFd {
+        self.0.as_raw_fd()
+    }
+}
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl From<PipeReader> for OwnedFd {
+    fn from(pipe: PipeReader) -> Self {
+        FileDesc::into_inner(AnonPipe::into_inner(pipe.0))
+    }
+}
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl FromRawFd for PipeReader {
+    unsafe fn from_raw_fd(raw_fd: RawFd) -> Self {
+        Self(AnonPipe::from_raw_fd(raw_fd))
+    }
+}
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl IntoRawFd for PipeReader {
+    fn into_raw_fd(self) -> RawFd {
+        self.0.into_raw_fd()
+    }
+}
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl From<PipeReader> for Stdio {
+    fn from(pipe: PipeReader) -> Self {
+        Self::from(OwnedFd::from(pipe))
+    }
+}
+
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl AsFd for PipeWriter {
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.0.as_fd()
+    }
+}
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl AsRawFd for PipeWriter {
+    fn as_raw_fd(&self) -> RawFd {
+        self.0.as_raw_fd()
+    }
+}
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl From<PipeWriter> for OwnedFd {
+    fn from(pipe: PipeWriter) -> Self {
+        FileDesc::into_inner(AnonPipe::into_inner(pipe.0))
+    }
+}
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl FromRawFd for PipeWriter {
+    unsafe fn from_raw_fd(raw_fd: RawFd) -> Self {
+        Self(AnonPipe::from_raw_fd(raw_fd))
+    }
+}
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl IntoRawFd for PipeWriter {
+    fn into_raw_fd(self) -> RawFd {
+        self.0.into_raw_fd()
+    }
+}
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl From<PipeWriter> for Stdio {
+    fn from(pipe: PipeWriter) -> Self {
+        Self::from(OwnedFd::from(pipe))
+    }
+}
+
+fn convert_to_pipe(owned_fd: OwnedFd) -> AnonPipe {
+    AnonPipe::from_inner(FileDesc::from_inner(OwnedFd::from(owned_fd)))
+}
+
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl From<OwnedFd> for PipeReader {
+    fn from(owned_fd: OwnedFd) -> Self {
+        Self(convert_to_pipe(owned_fd))
+    }
+}
+
+#[unstable(feature = "anonymous_pipe", issue = "127154")]
+impl From<OwnedFd> for PipeWriter {
+    fn from(owned_fd: OwnedFd) -> Self {
+        Self(convert_to_pipe(owned_fd))
+    }
+}