dirfd: preliminary unix and windows implementations

library/std/src/fs/tests.rs

@@ -1,5 +1,6 @@
 use rand::RngCore;
 
+use super::Dir;
 #[cfg(any(
     windows,
     target_os = "freebsd",
@@ -17,7 +18,7 @@ use crate::char::MAX_LEN_UTF8;
     target_vendor = "apple",
 ))]
 use crate::fs::TryLockError;
-use crate::fs::{self, File, FileTimes, OpenOptions};
+use crate::fs::{self, File, FileTimes, OpenOptions, create_dir};
 use crate::io::prelude::*;
 use crate::io::{BorrowedBuf, ErrorKind, SeekFrom};
 use crate::mem::MaybeUninit;
@@ -2084,3 +2085,93 @@ fn test_rename_junction() {
     // Junction links are always absolute so we just check the file name is correct.
     assert_eq!(fs::read_link(&dest).unwrap().file_name(), Some(not_exist.as_os_str()));
 }
+
+#[test]
+fn test_dir_smoke_test() {
+    let tmpdir = tmpdir();
+    check!(Dir::new(tmpdir.path()));
+}
+
+#[test]
+fn test_dir_read_file() {
+    let tmpdir = tmpdir();
+    let mut f = check!(File::create(tmpdir.join("foo.txt")));
+    check!(f.write(b"bar"));
+    check!(f.flush());
+    drop(f);
+    let dir = check!(Dir::new(tmpdir.path()));
+    let mut f = check!(dir.open("foo.txt"));
+    let mut buf = [0u8; 3];
+    check!(f.read_exact(&mut buf));
+    assert_eq!(b"bar", &buf);
+}
+
+#[test]
+fn test_dir_write_file() {
+    let tmpdir = tmpdir();
+    let dir = check!(Dir::new(tmpdir.path()));
+    let mut f = check!(dir.open_with("foo.txt", &OpenOptions::new().write(true).create(true)));
+    check!(f.write(b"bar"));
+    check!(f.flush());
+    drop(f);
+    let mut f = check!(File::open(tmpdir.join("foo.txt")));
+    let mut buf = [0u8; 3];
+    check!(f.read_exact(&mut buf));
+    assert_eq!(b"bar", &buf);
+}
+
+#[test]
+fn test_dir_remove_file() {
+    let tmpdir = tmpdir();
+    let mut f = check!(File::create(tmpdir.join("foo.txt")));
+    check!(f.write(b"bar"));
+    check!(f.flush());
+    drop(f);
+    let dir = check!(Dir::new(tmpdir.path()));
+    check!(dir.remove_file("foo.txt"));
+    let result = File::open(tmpdir.join("foo.txt"));
+    #[cfg(all(unix, not(target_os = "vxworks")))]
+    error!(result, "No such file or directory");
+    #[cfg(target_os = "vxworks")]
+    error!(result, "no such file or directory");
+    #[cfg(windows)]
+    error!(result, 2); // ERROR_FILE_NOT_FOUND
+}
+
+#[test]
+fn test_dir_remove_dir() {
+    let tmpdir = tmpdir();
+    check!(create_dir(tmpdir.join("foo")));
+    let dir = check!(Dir::new(tmpdir.path()));
+    check!(dir.remove_dir("foo"));
+    let result = Dir::new(tmpdir.join("foo"));
+    #[cfg(all(unix, not(target_os = "vxworks")))]
+    error!(result, "No such file or directory");
+    #[cfg(target_os = "vxworks")]
+    error!(result, "no such file or directory");
+    #[cfg(windows)]
+    error!(result, 2); // ERROR_FILE_NOT_FOUND
+}
+
+#[test]
+fn test_dir_rename_file() {
+    let tmpdir = tmpdir();
+    let mut f = check!(File::create(tmpdir.join("foo.txt")));
+    check!(f.write(b"bar"));
+    check!(f.flush());
+    drop(f);
+    let dir = check!(Dir::new(tmpdir.path()));
+    check!(dir.rename("foo.txt", &dir, "baz.txt"));
+    let mut f = check!(File::open(tmpdir.join("baz.txt")));
+    let mut buf = [0u8; 3];
+    check!(f.read_exact(&mut buf));
+    assert_eq!(b"bar", &buf);
+}
+
+#[test]
+fn test_dir_create_dir() {
+    let tmpdir = tmpdir();
+    let dir = check!(Dir::new(tmpdir.path()));
+    check!(dir.create_dir("foo"));
+    check!(Dir::new(tmpdir.join("foo")));
+}

library/std/src/sys/fs/common.rs

@@ -1,8 +1,10 @@
 #![allow(dead_code)] // not used on all platforms
 
-use crate::fs;
+use crate::fmt;
+use crate::fs::{self, create_dir, remove_dir, remove_file, rename};
 use crate::io::{self, Error, ErrorKind};
-use crate::path::Path;
+use crate::path::{Path, PathBuf};
+use crate::sys::fs::{File, OpenOptions};
 use crate::sys_common::ignore_notfound;
 
 pub(crate) const NOT_FILE_ERROR: Error = io::const_error!(
@@ -58,3 +60,66 @@ pub fn exists(path: &Path) -> io::Result<bool> {
         Err(error) => Err(error),
     }
 }
+
+pub struct Dir {
+    path: PathBuf,
+}
+
+impl Dir {
+    pub fn new<P: AsRef<Path>>(path: P) -> io::Result<Self> {
+        Ok(Self { path: path.as_ref().to_path_buf() })
+    }
+
+    pub fn new_with<P: AsRef<Path>>(path: P, _opts: &OpenOptions) -> io::Result<Self> {
+        Ok(Self { path: path.as_ref().to_path_buf() })
+    }
+
+    pub fn new_for_traversal<P: AsRef<Path>>(path: P) -> io::Result<Self> {
+        Ok(Self { path: path.as_ref().to_path_buf() })
+    }
+
+    pub fn open<P: AsRef<Path>>(&self, path: P) -> io::Result<File> {
+        let mut opts = OpenOptions::new();
+        opts.read(true);
+        File::open(&self.path.join(path), &opts)
+    }
+
+    pub fn open_with<P: AsRef<Path>>(&self, path: P, opts: &OpenOptions) -> io::Result<File> {
+        File::open(&self.path.join(path), opts)
+    }
+
+    pub fn create_dir<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
+        create_dir(self.path.join(path))
+    }
+
+    pub fn open_dir<P: AsRef<Path>>(&self, path: P) -> io::Result<Self> {
+        Self::new(self.path.join(path))
+    }
+
+    pub fn open_dir_with<P: AsRef<Path>>(&self, path: P, opts: &OpenOptions) -> io::Result<Self> {
+        Self::new_with(self.path.join(path), opts)
+    }
+
+    pub fn remove_file<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
+        remove_file(self.path.join(path))
+    }
+
+    pub fn remove_dir<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
+        remove_dir(self.path.join(path))
+    }
+
+    pub fn rename<P: AsRef<Path>, Q: AsRef<Path>>(
+        &self,
+        from: P,
+        to_dir: &Self,
+        to: Q,
+    ) -> io::Result<()> {
+        rename(self.path.join(from), to_dir.path.join(to))
+    }
+}
+
+impl fmt::Debug for Dir {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Dir").field("path", &self.path).finish()
+    }
+}

library/std/src/sys/fs/hermit.rs

@@ -11,14 +11,16 @@ use crate::path::{Path, PathBuf};
 use crate::sync::Arc;
 use crate::sys::common::small_c_string::run_path_with_cstr;
 use crate::sys::fd::FileDesc;
-pub use crate::sys::fs::common::{copy, exists};
+pub use crate::sys::fs::common::{Dir, copy, exists};
+use crate::sys::fs::{remove_dir, remove_file};
 use crate::sys::time::SystemTime;
 use crate::sys::{cvt, unsupported, unsupported_err};
 use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
 use crate::{fmt, mem};
 
 #[derive(Debug)]
 pub struct File(FileDesc);
+
 #[derive(Clone)]
 pub struct FileAttr {
     stat_val: stat_struct,
@@ -251,6 +253,32 @@ impl DirEntry {
     pub fn file_name_os_str(&self) -> &OsStr {
         self.name.as_os_str()
     }
+
+    pub fn open_file(&self) -> io::Result<File> {
+        let mut opts = OpenOptions::new();
+        opts.read(true);
+        File::open(&self.path(), &opts)
+    }
+
+    pub fn open_file_with(&self, opts: &OpenOptions) -> io::Result<File> {
+        File::open(&self.path(), opts)
+    }
+
+    pub fn open_dir(&self) -> io::Result<Dir> {
+        Dir::new(self.path())
+    }
+
+    pub fn open_dir_with(&self, opts: &OpenOptions) -> io::Result<Dir> {
+        Dir::new_with(self.path(), opts)
+    }
+
+    pub fn remove_file(&self) -> io::Result<()> {
+        remove_file(&self.path())
+    }
+
+    pub fn remove_dir(&self) -> io::Result<()> {
+        remove_dir(&self.path())
+    }
 }
 
 impl OpenOptions {

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

@@ -47,7 +47,7 @@ pub fn with_native_path<T>(path: &Path, f: &dyn Fn(&Path) -> io::Result<T>) -> i
 }
 
 pub use imp::{
-    DirBuilder, DirEntry, File, FileAttr, FilePermissions, FileTimes, FileType, OpenOptions,
+    Dir, DirBuilder, DirEntry, File, FileAttr, FilePermissions, FileTimes, FileType, OpenOptions,
     ReadDir,
 };
 

library/std/src/sys/fs/solid.rs

@@ -9,7 +9,8 @@ use crate::os::raw::{c_int, c_short};
 use crate::os::solid::ffi::OsStrExt;
 use crate::path::{Path, PathBuf};
 use crate::sync::Arc;
-pub use crate::sys::fs::common::exists;
+pub use crate::sys::fs::common::{Dir, exists};
+use crate::sys::fs::{remove_dir, remove_file};
 use crate::sys::pal::{abi, error};
 use crate::sys::time::SystemTime;
 use crate::sys::{unsupported, unsupported_err};
@@ -219,6 +220,32 @@ impl DirEntry {
             _ => lstat(&self.path()).map(|m| m.file_type()),
         }
     }
+
+    pub fn open_file(&self) -> io::Result<File> {
+        let mut opts = OpenOptions::new();
+        opts.read(true);
+        File::open(&self.path(), &opts)
+    }
+
+    pub fn open_file_with(&self, opts: &OpenOptions) -> io::Result<File> {
+        File::open(&self.path(), opts)
+    }
+
+    pub fn open_dir(&self) -> io::Result<Dir> {
+        Dir::new(self.path())
+    }
+
+    pub fn open_dir_with(&self, opts: &OpenOptions) -> io::Result<Dir> {
+        Dir::new_with(self.path(), opts)
+    }
+
+    pub fn remove_file(&self) -> io::Result<()> {
+        remove_file(&self.path())
+    }
+
+    pub fn remove_dir(&self) -> io::Result<()> {
+        remove_dir(&self.path())
+    }
 }
 
 impl OpenOptions {

library/std/src/sys/fs/uefi.rs

@@ -20,6 +20,8 @@ pub struct FileAttr {
     size: u64,
 }
 
+pub struct Dir(!);
+
 pub struct ReadDir(!);
 
 pub struct DirEntry(!);
@@ -115,6 +117,63 @@ impl FileType {
     }
 }
 
+impl Dir {
+    pub fn new<P: AsRef<Path>>(_path: P) -> io::Result<Self> {
+        unsupported()
+    }
+
+    pub fn new_with<P: AsRef<Path>>(_path: P, opts: &OpenOptions) -> io::Result<Self> {
+        unsupported()
+    }
+
+    pub fn new_for_traversal<P: AsRef<Path>>(_path: P) -> io::Result<Self> {
+        unsupported()
+    }
+
+    pub fn open<P: AsRef<Path>>(&self, _path: P) -> io::Result<File> {
+        self.0
+    }
+
+    pub fn open_with<P: AsRef<Path>>(&self, _path: P, opts: &OpenOptions) -> io::Result<File> {
+        self.0
+    }
+
+    pub fn create_dir<P: AsRef<Path>>(&self, _path: P) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn open_dir<P: AsRef<Path>>(&self, _path: P) -> io::Result<Self> {
+        self.0
+    }
+
+    pub fn open_dir_with<P: AsRef<Path>>(&self, _path: P, _opts: &OpenOptions) -> io::Result<Self> {
+        self.0
+    }
+
+    pub fn remove_file<P: AsRef<Path>>(&self, _path: P) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn remove_dir<P: AsRef<Path>>(&self, _path: P) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn rename<P: AsRef<Path>, Q: AsRef<Path>>(
+        &self,
+        _from: P,
+        _to_dir: &Self,
+        _to: Q,
+    ) -> io::Result<()> {
+        self.0
+    }
+}
+
+impl fmt::Debug for Dir {
+    fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.0
+    }
+}
+
 impl fmt::Debug for ReadDir {
     fn fmt(&self, _f: &mut fmt::Formatter<'_>) -> fmt::Result {
         self.0
@@ -145,6 +204,30 @@ impl DirEntry {
     pub fn file_type(&self) -> io::Result<FileType> {
         self.0
     }
+
+    pub fn open_file(&self) -> io::Result<File> {
+        self.0
+    }
+
+    pub fn open_file_with(&self, _opts: &OpenOptions) -> io::Result<File> {
+        self.0
+    }
+
+    pub fn open_dir(&self) -> io::Result<Dir> {
+        self.0
+    }
+
+    pub fn open_dir_with(&self, _opts: &OpenOptions) -> io::Result<Dir> {
+        self.0
+    }
+
+    pub fn remove_file(&self) -> io::Result<()> {
+        self.0
+    }
+
+    pub fn remove_dir(&self) -> io::Result<()> {
+        self.0
+    }
 }
 
 impl OpenOptions {