Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

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

1 files changed, 276 insertions, 0 deletions

diff --git a/third_party/rust/nix/src/dir.rs b/third_party/rust/nix/src/dir.rs
new file mode 100644
index 0000000000..5ce503644e
--- /dev/null
+++ b/third_party/rust/nix/src/dir.rs
@@ -0,0 +1,276 @@
+//! List directory contents
+
+use crate::errno::Errno;
+use crate::fcntl::{self, OFlag};
+use crate::sys;
+use crate::{Error, NixPath, Result};
+use cfg_if::cfg_if;
+use std::ffi;
+use std::os::unix::io::{AsRawFd, IntoRawFd, RawFd};
+use std::ptr;
+
+#[cfg(target_os = "linux")]
+use libc::{dirent64 as dirent, readdir64_r as readdir_r};
+
+#[cfg(not(target_os = "linux"))]
+use libc::{dirent, readdir_r};
+
+/// An open directory.
+///
+/// This is a lower-level interface than `std::fs::ReadDir`. Notable differences:
+///    * can be opened from a file descriptor (as returned by `openat`, perhaps before knowing
+///      if the path represents a file or directory).
+///    * implements `AsRawFd`, so it can be passed to `fstat`, `openat`, etc.
+///      The file descriptor continues to be owned by the `Dir`, so callers must not keep a `RawFd`
+///      after the `Dir` is dropped.
+///    * can be iterated through multiple times without closing and reopening the file
+///      descriptor. Each iteration rewinds when finished.
+///    * returns entries for `.` (current directory) and `..` (parent directory).
+///    * returns entries' names as a `CStr` (no allocation or conversion beyond whatever libc
+///      does).
+#[derive(Debug, Eq, Hash, PartialEq)]
+pub struct Dir(ptr::NonNull<libc::DIR>);
+
+impl Dir {
+    /// Opens the given path as with `fcntl::open`.
+    pub fn open<P: ?Sized + NixPath>(
+        path: &P,
+        oflag: OFlag,
+        mode: sys::stat::Mode,
+    ) -> Result<Self> {
+        let fd = fcntl::open(path, oflag, mode)?;
+        Dir::from_fd(fd)
+    }
+
+    /// Opens the given path as with `fcntl::openat`.
+    pub fn openat<P: ?Sized + NixPath>(
+        dirfd: RawFd,
+        path: &P,
+        oflag: OFlag,
+        mode: sys::stat::Mode,
+    ) -> Result<Self> {
+        let fd = fcntl::openat(dirfd, path, oflag, mode)?;
+        Dir::from_fd(fd)
+    }
+
+    /// Converts from a descriptor-based object, closing the descriptor on success or failure.
+    #[inline]
+    pub fn from<F: IntoRawFd>(fd: F) -> Result<Self> {
+        Dir::from_fd(fd.into_raw_fd())
+    }
+
+    /// Converts from a file descriptor, closing it on success or failure.
+    #[doc(alias("fdopendir"))]
+    pub fn from_fd(fd: RawFd) -> Result<Self> {
+        let d = ptr::NonNull::new(unsafe { libc::fdopendir(fd) }).ok_or_else(
+            || {
+                let e = Error::last();
+                unsafe { libc::close(fd) };
+                e
+            },
+        )?;
+        Ok(Dir(d))
+    }
+
+    /// Returns an iterator of `Result<Entry>` which rewinds when finished.
+    pub fn iter(&mut self) -> Iter {
+        Iter(self)
+    }
+}
+
+// `Dir` is not `Sync`. With the current implementation, it could be, but according to
+// https://www.gnu.org/software/libc/manual/html_node/Reading_002fClosing-Directory.html,
+// future versions of POSIX are likely to obsolete `readdir_r` and specify that it's unsafe to
+// call `readdir` simultaneously from multiple threads.
+//
+// `Dir` is safe to pass from one thread to another, as it's not reference-counted.
+unsafe impl Send for Dir {}
+
+impl AsRawFd for Dir {
+    fn as_raw_fd(&self) -> RawFd {
+        unsafe { libc::dirfd(self.0.as_ptr()) }
+    }
+}
+
+impl Drop for Dir {
+    fn drop(&mut self) {
+        let e = Errno::result(unsafe { libc::closedir(self.0.as_ptr()) });
+        if !std::thread::panicking() && e == Err(Errno::EBADF) {
+            panic!("Closing an invalid file descriptor!");
+        };
+    }
+}
+
+fn next(dir: &mut Dir) -> Option<Result<Entry>> {
+    unsafe {
+        // Note: POSIX specifies that portable applications should dynamically allocate a
+        // buffer with room for a `d_name` field of size `pathconf(..., _PC_NAME_MAX)` plus 1
+        // for the NUL byte. It doesn't look like the std library does this; it just uses
+        // fixed-sized buffers (and libc's dirent seems to be sized so this is appropriate).
+        // Probably fine here too then.
+        let mut ent = std::mem::MaybeUninit::<dirent>::uninit();
+        let mut result = ptr::null_mut();
+        if let Err(e) = Errno::result(readdir_r(
+            dir.0.as_ptr(),
+            ent.as_mut_ptr(),
+            &mut result,
+        )) {
+            return Some(Err(e));
+        }
+        if result.is_null() {
+            return None;
+        }
+        assert_eq!(result, ent.as_mut_ptr());
+        Some(Ok(Entry(ent.assume_init())))
+    }
+}
+
+/// Return type of [`Dir::iter`].
+#[derive(Debug, Eq, Hash, PartialEq)]
+pub struct Iter<'d>(&'d mut Dir);
+
+impl<'d> Iterator for Iter<'d> {
+    type Item = Result<Entry>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        next(self.0)
+    }
+}
+
+impl<'d> Drop for Iter<'d> {
+    fn drop(&mut self) {
+        unsafe { libc::rewinddir((self.0).0.as_ptr()) }
+    }
+}
+
+/// The return type of [Dir::into_iter]
+#[derive(Debug, Eq, Hash, PartialEq)]
+pub struct OwningIter(Dir);
+
+impl Iterator for OwningIter {
+    type Item = Result<Entry>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        next(&mut self.0)
+    }
+}
+
+/// The file descriptor continues to be owned by the `OwningIter`,
+/// so callers must not keep a `RawFd` after the `OwningIter` is dropped.
+impl AsRawFd for OwningIter {
+    fn as_raw_fd(&self) -> RawFd {
+        self.0.as_raw_fd()
+    }
+}
+
+impl IntoIterator for Dir {
+    type Item = Result<Entry>;
+    type IntoIter = OwningIter;
+
+    /// Creates a owning iterator, that is, one that takes ownership of the
+    /// `Dir`. The `Dir` cannot be used after calling this.  This can be useful
+    /// when you have a function that both creates a `Dir` instance and returns
+    /// an `Iterator`.
+    ///
+    /// Example:
+    ///
+    /// ```
+    /// use nix::{dir::Dir, fcntl::OFlag, sys::stat::Mode};
+    /// use std::{iter::Iterator, string::String};
+    ///
+    /// fn ls_upper(dirname: &str) -> impl Iterator<Item=String> {
+    ///     let d = Dir::open(dirname, OFlag::O_DIRECTORY, Mode::S_IXUSR).unwrap();
+    ///     d.into_iter().map(|x| x.unwrap().file_name().as_ref().to_string_lossy().to_ascii_uppercase())
+    /// }
+    /// ```
+    fn into_iter(self) -> Self::IntoIter {
+        OwningIter(self)
+    }
+}
+
+/// A directory entry, similar to `std::fs::DirEntry`.
+///
+/// Note that unlike the std version, this may represent the `.` or `..` entries.
+#[derive(Copy, Clone, Debug, Eq, Hash, PartialEq)]
+#[repr(transparent)]
+pub struct Entry(dirent);
+
+/// Type of file referenced by a directory entry
+#[derive(Copy, Clone, Debug, Eq, Hash, PartialEq)]
+pub enum Type {
+    /// FIFO (Named pipe)
+    Fifo,
+    /// Character device
+    CharacterDevice,
+    /// Directory
+    Directory,
+    /// Block device
+    BlockDevice,
+    /// Regular file
+    File,
+    /// Symbolic link
+    Symlink,
+    /// Unix-domain socket
+    Socket,
+}
+
+impl Entry {
+    /// Returns the inode number (`d_ino`) of the underlying `dirent`.
+    #[allow(clippy::useless_conversion)] // Not useless on all OSes
+    // The cast is not unnecessary on all platforms.
+    #[allow(clippy::unnecessary_cast)]
+    pub fn ino(&self) -> u64 {
+        cfg_if! {
+            if #[cfg(any(target_os = "android",
+                         target_os = "emscripten",
+                         target_os = "fuchsia",
+                         target_os = "haiku",
+                         target_os = "illumos",
+                         target_os = "ios",
+                         target_os = "l4re",
+                         target_os = "linux",
+                         target_os = "macos",
+                         target_os = "solaris"))] {
+                self.0.d_ino as u64
+            } else {
+                u64::from(self.0.d_fileno)
+            }
+        }
+    }
+
+    /// Returns the bare file name of this directory entry without any other leading path component.
+    pub fn file_name(&self) -> &ffi::CStr {
+        unsafe { ::std::ffi::CStr::from_ptr(self.0.d_name.as_ptr()) }
+    }
+
+    /// Returns the type of this directory entry, if known.
+    ///
+    /// See platform `readdir(3)` or `dirent(5)` manpage for when the file type is known;
+    /// notably, some Linux filesystems don't implement this. The caller should use `stat` or
+    /// `fstat` if this returns `None`.
+    pub fn file_type(&self) -> Option<Type> {
+        #[cfg(not(any(
+            target_os = "illumos",
+            target_os = "solaris",
+            target_os = "haiku"
+        )))]
+        match self.0.d_type {
+            libc::DT_FIFO => Some(Type::Fifo),
+            libc::DT_CHR => Some(Type::CharacterDevice),
+            libc::DT_DIR => Some(Type::Directory),
+            libc::DT_BLK => Some(Type::BlockDevice),
+            libc::DT_REG => Some(Type::File),
+            libc::DT_LNK => Some(Type::Symlink),
+            libc::DT_SOCK => Some(Type::Socket),
+            /* libc::DT_UNKNOWN | */ _ => None,
+        }
+
+        // illumos, Solaris, and Haiku systems do not have the d_type member at all:
+        #[cfg(any(
+            target_os = "illumos",
+            target_os = "solaris",
+            target_os = "haiku"
+        ))]
+        None
+    }
+}