std: add platform support for hexagon-unknown-qurt

QuRT provides POSIX-like APIs for basic operations, so this implementation
reuses the unix platform abstraction layer with QuRT-specific customizations.

Platform modules:
- New os::qurt module with platform-specific extensions to ffi, fs, io, raw
- QuRT-specific file handling for ino, dev, mode, nlink, etc.

Unsupported: Networking, fork/exec, pipe, chown/fchown/lchown/chroot/mkfifo

Author: androm3da

library/std/src/os/fd/mod.rs

@@ -13,10 +13,10 @@ mod raw;
 mod owned;
 
 // Implementations for `AsRawFd` etc. for network types.
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 mod net;
 
-#[cfg(test)]
+#[cfg(all(test, not(target_os = "qurt")))]
 mod tests;
 
 // Export the types and traits for the public API.

library/std/src/os/fd/owned.rs

@@ -210,7 +210,7 @@ impl Drop for OwnedFd {
             // the latest POSIX wording: http://austingroupbugs.net/view.php?id=529
             #[cfg(not(target_os = "hermit"))]
             {
-                #[cfg(unix)]
+                #[cfg(all(unix, not(target_os = "qurt")))]
                 crate::sys::fs::debug_assert_fd_is_open(self.fd.as_inner());
 
                 let _ = libc::close(self.fd.as_inner());
@@ -344,7 +344,7 @@ impl From<OwnedFd> for fs::File {
 }
 
 #[stable(feature = "io_safety", since = "1.63.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl AsFd for crate::net::TcpStream {
     #[inline]
     fn as_fd(&self) -> BorrowedFd<'_> {
@@ -353,7 +353,7 @@ impl AsFd for crate::net::TcpStream {
 }
 
 #[stable(feature = "io_safety", since = "1.63.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl From<crate::net::TcpStream> for OwnedFd {
     /// Takes ownership of a [`TcpStream`](crate::net::TcpStream)'s socket file descriptor.
     #[inline]
@@ -363,7 +363,7 @@ impl From<crate::net::TcpStream> for OwnedFd {
 }
 
 #[stable(feature = "io_safety", since = "1.63.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl From<OwnedFd> for crate::net::TcpStream {
     #[inline]
     fn from(owned_fd: OwnedFd) -> Self {
@@ -374,7 +374,7 @@ impl From<OwnedFd> for crate::net::TcpStream {
 }
 
 #[stable(feature = "io_safety", since = "1.63.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl AsFd for crate::net::TcpListener {
     #[inline]
     fn as_fd(&self) -> BorrowedFd<'_> {
@@ -383,7 +383,7 @@ impl AsFd for crate::net::TcpListener {
 }
 
 #[stable(feature = "io_safety", since = "1.63.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl From<crate::net::TcpListener> for OwnedFd {
     /// Takes ownership of a [`TcpListener`](crate::net::TcpListener)'s socket file descriptor.
     #[inline]
@@ -393,7 +393,7 @@ impl From<crate::net::TcpListener> for OwnedFd {
 }
 
 #[stable(feature = "io_safety", since = "1.63.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl From<OwnedFd> for crate::net::TcpListener {
     #[inline]
     fn from(owned_fd: OwnedFd) -> Self {
@@ -404,7 +404,7 @@ impl From<OwnedFd> for crate::net::TcpListener {
 }
 
 #[stable(feature = "io_safety", since = "1.63.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl AsFd for crate::net::UdpSocket {
     #[inline]
     fn as_fd(&self) -> BorrowedFd<'_> {
@@ -413,7 +413,7 @@ impl AsFd for crate::net::UdpSocket {
 }
 
 #[stable(feature = "io_safety", since = "1.63.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl From<crate::net::UdpSocket> for OwnedFd {
     /// Takes ownership of a [`UdpSocket`](crate::net::UdpSocket)'s file descriptor.
     #[inline]
@@ -423,7 +423,7 @@ impl From<crate::net::UdpSocket> for OwnedFd {
 }
 
 #[stable(feature = "io_safety", since = "1.63.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl From<OwnedFd> for crate::net::UdpSocket {
     #[inline]
     fn from(owned_fd: OwnedFd) -> Self {
@@ -532,47 +532,47 @@ impl<'a> AsFd for io::StderrLock<'a> {
 }
 
 #[stable(feature = "anonymous_pipe", since = "1.87.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl AsFd for io::PipeReader {
     fn as_fd(&self) -> BorrowedFd<'_> {
         self.0.as_fd()
     }
 }
 
 #[stable(feature = "anonymous_pipe", since = "1.87.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl From<io::PipeReader> for OwnedFd {
     fn from(pipe: io::PipeReader) -> Self {
         pipe.0.into_inner()
     }
 }
 
 #[stable(feature = "anonymous_pipe", since = "1.87.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl AsFd for io::PipeWriter {
     fn as_fd(&self) -> BorrowedFd<'_> {
         self.0.as_fd()
     }
 }
 
 #[stable(feature = "anonymous_pipe", since = "1.87.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl From<io::PipeWriter> for OwnedFd {
     fn from(pipe: io::PipeWriter) -> Self {
         pipe.0.into_inner()
     }
 }
 
 #[stable(feature = "anonymous_pipe", since = "1.87.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl From<OwnedFd> for io::PipeReader {
     fn from(owned_fd: OwnedFd) -> Self {
         Self(FromInner::from_inner(owned_fd))
     }
 }
 
 #[stable(feature = "anonymous_pipe", since = "1.87.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl From<OwnedFd> for io::PipeWriter {
     fn from(owned_fd: OwnedFd) -> Self {
         Self(FromInner::from_inner(owned_fd))

library/std/src/os/fd/raw.rs

@@ -193,7 +193,7 @@ impl IntoRawFd for fs::File {
 }
 
 #[stable(feature = "asraw_stdio", since = "1.21.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl AsRawFd for io::Stdin {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
@@ -202,6 +202,7 @@ impl AsRawFd for io::Stdin {
 }
 
 #[stable(feature = "asraw_stdio", since = "1.21.0")]
+#[cfg(not(target_os = "qurt"))]
 impl AsRawFd for io::Stdout {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
@@ -210,6 +211,7 @@ impl AsRawFd for io::Stdout {
 }
 
 #[stable(feature = "asraw_stdio", since = "1.21.0")]
+#[cfg(not(target_os = "qurt"))]
 impl AsRawFd for io::Stderr {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
@@ -218,7 +220,7 @@ impl AsRawFd for io::Stderr {
 }
 
 #[stable(feature = "asraw_stdio_locks", since = "1.35.0")]
-#[cfg(not(target_os = "trusty"))]
+#[cfg(not(any(target_os = "trusty", target_os = "qurt")))]
 impl<'a> AsRawFd for io::StdinLock<'a> {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
@@ -227,6 +229,7 @@ impl<'a> AsRawFd for io::StdinLock<'a> {
 }
 
 #[stable(feature = "asraw_stdio_locks", since = "1.35.0")]
+#[cfg(not(target_os = "qurt"))]
 impl<'a> AsRawFd for io::StdoutLock<'a> {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
@@ -235,6 +238,7 @@ impl<'a> AsRawFd for io::StdoutLock<'a> {
 }
 
 #[stable(feature = "asraw_stdio_locks", since = "1.35.0")]
+#[cfg(not(target_os = "qurt"))]
 impl<'a> AsRawFd for io::StderrLock<'a> {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {

library/std/src/os/mod.rs

@@ -165,6 +165,8 @@ pub mod nto;
 pub mod nuttx;
 #[cfg(target_os = "openbsd")]
 pub mod openbsd;
+#[cfg(target_os = "qurt")]
+pub mod qurt;
 #[cfg(target_os = "redox")]
 pub mod redox;
 #[cfg(target_os = "rtems")]

library/std/src/os/qurt/ffi.rs

@@ -0,0 +1,65 @@
+//! QuRT-specific extension to the primitives in the [`std::ffi`] module.
+//!
+//! [`std::ffi`]: crate::ffi
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+use crate::ffi::{OsStr, OsString};
+use crate::mem;
+use crate::sealed::Sealed;
+use crate::sys::os_str::Buf;
+use crate::sys::{AsInner, FromInner, IntoInner};
+
+/// QuRT-specific extensions to [`OsString`].
+///
+/// This trait is sealed: it cannot be implemented outside the standard library.
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub trait OsStringExt: Sealed {
+    /// Creates an [`OsString`] from a byte vector.
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    fn from_vec(vec: Vec<u8>) -> Self;
+
+    /// Yields the underlying byte vector of this [`OsString`].
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    fn into_vec(self) -> Vec<u8>;
+}
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+impl OsStringExt for OsString {
+    #[inline]
+    fn from_vec(vec: Vec<u8>) -> OsString {
+        FromInner::from_inner(Buf { inner: vec })
+    }
+
+    #[inline]
+    fn into_vec(self) -> Vec<u8> {
+        self.into_inner().inner
+    }
+}
+
+/// QuRT-specific extensions to [`OsStr`].
+///
+/// This trait is sealed: it cannot be implemented outside the standard library.
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub trait OsStrExt: Sealed {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    /// Creates an [`OsStr`] from a byte slice.
+    fn from_bytes(slice: &[u8]) -> &Self;
+
+    /// Gets the underlying byte view of the [`OsStr`] slice.
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    fn as_bytes(&self) -> &[u8];
+}
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+impl OsStrExt for OsStr {
+    #[inline]
+    fn from_bytes(slice: &[u8]) -> &OsStr {
+        unsafe { mem::transmute(slice) }
+    }
+
+    #[inline]
+    fn as_bytes(&self) -> &[u8] {
+        &self.as_inner().inner
+    }
+}