Use rustix instead of libc (additive only approach)

CHANGELOG.md

@@ -1,3 +1,8 @@
+# Unreleased
+
+- Use Rustix by default instead of libc. Libc can be re-enabled if necessary with the libc feature flag.
+- `FileDesc` now requires a lifetime annotation.
+
 # Version 0.27.1
 
 ## Added ⭐

Cargo.toml

@@ -10,7 +10,7 @@ keywords = ["event", "color", "cli", "input", "terminal"]
 exclude = ["target", "Cargo.lock"]
 readme = "README.md"
 edition = "2021"
-rust-version = "1.58.0"
+rust-version = "1.63.0"
 categories = ["command-line-interface", "command-line-utilities"]
 
 [lib]
@@ -71,7 +71,14 @@ crossterm_winapi = { version = "0.9.1", optional = true }
 # UNIX dependencies
 #
 [target.'cfg(unix)'.dependencies]
-libc = "0.2"
+# Default to using rustix for UNIX systems, but provide an option to use libc for backwards
+# compatibility.
+libc = { version = "0.2", default-features = false, optional = true }
+rustix = { version = "0.38.34", default-features = false, features = [
+    "std",
+    "stdio",
+    "termios",
+] }
 signal-hook = { version = "0.3.17", optional = true }
 filedescriptor = { version = "0.8", optional = true }
 mio = { version = "0.8", features = ["os-poll"], optional = true }

src/event/source/unix/mio.rs

@@ -26,7 +26,7 @@ pub(crate) struct UnixInternalEventSource {
     events: Events,
     parser: Parser,
     tty_buffer: [u8; TTY_BUFFER_SIZE],
-    tty_fd: FileDesc,
+    tty_fd: FileDesc<'static>,
     signals: Signals,
     #[cfg(feature = "event-stream")]
     waker: Waker,
@@ -37,7 +37,7 @@ impl UnixInternalEventSource {
         UnixInternalEventSource::from_file_descriptor(tty_fd()?)
     }
 
-    pub(crate) fn from_file_descriptor(input_fd: FileDesc) -> io::Result<Self> {
+    pub(crate) fn from_file_descriptor(input_fd: FileDesc<'static>) -> io::Result<Self> {
         let poll = Poll::new()?;
         let registry = poll.registry();
 

src/event/source/unix/tty.rs

@@ -1,6 +1,10 @@
+#[cfg(feature = "libc")]
 use std::os::unix::prelude::AsRawFd;
 use std::{collections::VecDeque, io, os::unix::net::UnixStream, time::Duration};
 
+#[cfg(not(feature = "libc"))]
+use rustix::fd::{AsFd, AsRawFd};
+
 use signal_hook::low_level::pipe;
 
 use crate::event::timeout::PollTimeout;
@@ -38,7 +42,7 @@ const TTY_BUFFER_SIZE: usize = 1_024;
 pub(crate) struct UnixInternalEventSource {
     parser: Parser,
     tty_buffer: [u8; TTY_BUFFER_SIZE],
-    tty: FileDesc,
+    tty: FileDesc<'static>,
     winch_signal_receiver: UnixStream,
     #[cfg(feature = "event-stream")]
     wake_pipe: WakePipe,
@@ -56,15 +60,18 @@ impl UnixInternalEventSource {
         UnixInternalEventSource::from_file_descriptor(tty_fd()?)
     }
 
-    pub(crate) fn from_file_descriptor(input_fd: FileDesc) -> io::Result<Self> {
+    pub(crate) fn from_file_descriptor(input_fd: FileDesc<'static>) -> io::Result<Self> {
         Ok(UnixInternalEventSource {
             parser: Parser::default(),
             tty_buffer: [0u8; TTY_BUFFER_SIZE],
             tty: input_fd,
             winch_signal_receiver: {
                 let (receiver, sender) = nonblocking_unix_pair()?;
                 // Unregistering is unnecessary because EventSource is a singleton
+                #[cfg(feature = "libc")]
                 pipe::register(libc::SIGWINCH, sender)?;
+                #[cfg(not(feature = "libc"))]
+                pipe::register(rustix::process::Signal::Winch as i32, sender)?;
                 receiver
             },
             #[cfg(feature = "event-stream")]
@@ -157,7 +164,10 @@ impl EventSource for UnixInternalEventSource {
                 }
             }
             if fds[1].revents & POLLIN != 0 {
+                #[cfg(feature = "libc")]
                 let fd = FileDesc::new(self.winch_signal_receiver.as_raw_fd(), false);
+                #[cfg(not(feature = "libc"))]
+                let fd = FileDesc::Borrowed(self.winch_signal_receiver.as_fd());
                 // drain the pipe
                 while read_complete(&fd, &mut [0; 1024])? != 0 {}
                 // TODO Should we remove tput?

src/terminal/sys/file_descriptor.rs

@@ -1,32 +1,51 @@
+use std::io;
+
+#[cfg(feature = "libc")]
+use libc::size_t;
+#[cfg(not(feature = "libc"))]
+use rustix::fd::{AsFd, AsRawFd, BorrowedFd, OwnedFd, RawFd};
+#[cfg(feature = "libc")]
 use std::{
-    fs, io,
+    fs,
+    marker::PhantomData,
     os::unix::{
         io::{IntoRawFd, RawFd},
         prelude::AsRawFd,
     },
 };
 
-use libc::size_t;
-
 /// A file descriptor wrapper.
 ///
 /// It allows to retrieve raw file descriptor, write to the file descriptor and
 /// mainly it closes the file descriptor once dropped.
 #[derive(Debug)]
-pub struct FileDesc {
+#[cfg(feature = "libc")]
+pub struct FileDesc<'a> {
     fd: RawFd,
     close_on_drop: bool,
+    phantom: PhantomData<&'a ()>,
 }
 
-impl FileDesc {
+#[cfg(not(feature = "libc"))]
+pub enum FileDesc<'a> {
+    Owned(OwnedFd),
+    Borrowed(BorrowedFd<'a>),
+}
+
+#[cfg(feature = "libc")]
+impl FileDesc<'_> {
     /// Constructs a new `FileDesc` with the given `RawFd`.
     ///
     /// # Arguments
     ///
     /// * `fd` - raw file descriptor
     /// * `close_on_drop` - specify if the raw file descriptor should be closed once the `FileDesc` is dropped
-    pub fn new(fd: RawFd, close_on_drop: bool) -> FileDesc {
-        FileDesc { fd, close_on_drop }
+    pub fn new(fd: RawFd, close_on_drop: bool) -> FileDesc<'static> {
+        FileDesc {
+            fd,
+            close_on_drop,
+            phantom: PhantomData,
+        }
     }
 
     pub fn read(&self, buffer: &mut [u8]) -> io::Result<usize> {
@@ -51,7 +70,27 @@
     }
 }
 
-impl Drop for FileDesc {
+#[cfg(not(feature = "libc"))]
+impl FileDesc<'_> {
+    pub fn read(&self, buffer: &mut [u8]) -> io::Result<usize> {
+        let fd = match self {
+            FileDesc::Owned(fd) => fd.as_fd(),
+            FileDesc::Borrowed(fd) => fd.as_fd(),
+        };
+        let result = rustix::io::read(fd, buffer)?;
+        Ok(result)
+    }
+
+    pub fn raw_fd(&self) -> RawFd {
+        match self {
+            FileDesc::Owned(fd) => fd.as_raw_fd(),
+            FileDesc::Borrowed(fd) => fd.as_raw_fd(),
+        }
+    }
+}
+
+#[cfg(feature = "libc")]
+impl Drop for FileDesc<'_> {
     fn drop(&mut self) {
         if self.close_on_drop {
             // Note that errors are ignored when closing a file descriptor. The
@@ -64,14 +103,25 @@
     }
 }
 
-impl AsRawFd for FileDesc {
+impl AsRawFd for FileDesc<'_> {
     fn as_raw_fd(&self) -> RawFd {
         self.raw_fd()
     }
 }
 
+#[cfg(not(feature = "libc"))]
+impl AsFd for FileDesc<'_> {
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        match self {
+            FileDesc::Owned(fd) => fd.as_fd(),
+            FileDesc::Borrowed(fd) => fd.as_fd(),
+        }
+    }
+}
+
+#[cfg(feature = "libc")]
 /// Creates a file descriptor pointing to the standard input or `/dev/tty`.
-pub fn tty_fd() -> io::Result<FileDesc> {
+pub fn tty_fd() -> io::Result<FileDesc<'static>> {
     let (fd, close_on_drop) = if unsafe { libc::isatty(libc::STDIN_FILENO) == 1 } {
         (libc::STDIN_FILENO, false)
     } else {
@@ -87,3 +137,18 @@
 
     Ok(FileDesc::new(fd, close_on_drop))
 }
+
+#[cfg(not(feature = "libc"))]
+/// Creates a file descriptor pointing to the standard input or `/dev/tty`.
+pub fn tty_fd() -> io::Result<FileDesc<'static>> {
+    use std::fs::File;
+
+    let stdin = rustix::stdio::stdin();
+    let fd = if rustix::termios::isatty(stdin) {
+        FileDesc::Borrowed(stdin)
+    } else {
+        let dev_tty = File::options().read(true).write(true).open("/dev/tty")?;
+        FileDesc::Owned(dev_tty.into())
+    };
+    Ok(fd)
+}