host_env: os.mkdir for Windows, Redox

joshuamegnauth54 · joshuamegnauth54 · commit 40dfeeeee9c4 · 2026-06-17T23:37:15.000-04:00
Python supports `mkdir` on Windows. I deferred to calling Rust's
implementation for now. However, like `rename`, Python's implementation
supports additional features that are currently unsupported on
RustPython. I added a note for future reference.

Redox supports `mkdirat` which significantly cleans up the
implementation.
diff --git a/crates/host_env/src/posix.rs b/crates/host_env/src/posix.rs
@@ -10,6 +10,8 @@ use std::os::fd::FromRawFd;
 use std::os::fd::{AsFd, AsRawFd, BorrowedFd, IntoRawFd, OwnedFd};
 use std::path::Path;
 
+use crate::crt_fd;
+
 pub struct UnameInfo {
     pub sysname: String,
     pub nodename: String,
@@ -174,24 +176,32 @@ pub fn fcopyfile(in_fd: i32, out_fd: i32, flags: u32) -> std::io::Result<()> {
     }
 }
 
-#[cfg(not(windows))]
-pub fn make_dir(path: &CStr, mode: u32) -> std::io::Result<()> {
-    let ret = unsafe { libc::mkdir(path.as_ptr(), mode as _) };
-    if ret < 0 {
-        Err(std::io::Error::last_os_error())
+#[cfg(not(unix))]
+pub fn make_dir(
+    dir_fd: Option<crt_fd::Borrowed<'_>>,
+    path: &Path,
+    _mode: u32,
+) -> std::io::Result<()> {
+    // TODO: On Windows, Python has an override if the mode is 0o700
+    if dir_fd.is_none() {
+        std::fs::create_dir(path)
     } else {
-        Ok(())
+        core::hint::cold_path();
+        Err(std::io::Error::new(
+            std::io::ErrorKind::Unsupported,
+            "mkdirat is not available on this platform",
+        ))
     }
 }
 
-#[cfg(all(not(windows), not(target_os = "redox")))]
-pub fn make_dir_at(dir_fd: i32, path: &CStr, mode: u32) -> std::io::Result<()> {
-    let ret = unsafe { libc::mkdirat(dir_fd, path.as_ptr(), mode as _) };
-    if ret < 0 {
-        Err(std::io::Error::last_os_error())
-    } else {
-        Ok(())
-    }
+#[cfg(unix)]
+pub fn make_dir(
+    dir_fd: Option<crt_fd::Borrowed<'_>>,
+    path: &Path,
+    mode: u32,
+) -> std::io::Result<()> {
+    let dir_fd = dir_fd.as_ref().map_or(rustix::fs::CWD, AsFd::as_fd);
+    rustix::fs::mkdirat(dir_fd, path, mode.into()).map_err(Into::into)
 }
 
 #[cfg(unix)]
diff --git a/crates/host_env/src/posix_wasi.rs b/crates/host_env/src/posix_wasi.rs
@@ -1,17 +1,17 @@
 use alloc::ffi::CString;
 use core::{ffi::CStr, time::Duration};
-use std::{ffi::OsStr, io};
+use rustix::fd::AsFd;
+use std::{ffi::OsStr, io, path::Path};
 
-use crate::os::CheckLibcResult;
+use crate::{crt_fd, os::CheckLibcResult};
 
-pub fn make_dir(path: &CStr, mode: u32) -> io::Result<()> {
-    unsafe { libc::mkdir(path.as_ptr(), mode as _) }.check_libc_neg()?;
-    Ok(())
-}
-
-pub fn make_dir_at(dir_fd: i32, path: &CStr, mode: u32) -> io::Result<()> {
-    unsafe { libc::mkdirat(dir_fd, path.as_ptr(), mode as _) }.check_libc_neg()?;
-    Ok(())
+pub fn make_dir(
+    dir_fd: Option<crt_fd::Borrowed<'_>>,
+    path: &Path,
+    mode: u32,
+) -> std::io::Result<()> {
+    let dir_fd = dir_fd.as_ref().map_or(rustix::fs::CWD, AsFd::as_fd);
+    rustix::fs::mkdirat(dir_fd, path, mode.into()).map_err(Into::into)
 }
 
 pub fn remove_dir_at(dir_fd: i32, path: &CStr) -> io::Result<()> {
diff --git a/crates/vm/src/stdlib/os.rs b/crates/vm/src/stdlib/os.rs
@@ -29,7 +29,7 @@ pub struct TargetIsDirectory {
 }
 
 cfg_select! {
-    all(any(unix, target_os = "wasi"), not(target_os = "redox")) => {
+    any(unix, target_os = "wasi") => {
         use libc::AT_FDCWD;
     }
     _ => {
@@ -181,10 +181,14 @@ pub(super) mod _os {
     use rustpython_host_env::nt as host_nt;
     #[cfg(all(any(unix, target_os = "wasi"), not(target_os = "redox")))]
     use rustpython_host_env::posix as host_posix;
-    use std::{fs, io, path::PathBuf, time::SystemTime};
+    use std::{
+        fs, io,
+        path::{Path, PathBuf},
+        time::SystemTime,
+    };
 
     const OPEN_DIR_FD: bool = cfg!(not(any(windows, target_os = "redox")));
-    pub(crate) const MKDIR_DIR_FD: bool = cfg!(not(any(windows, target_os = "redox")));
+    pub(crate) const MKDIR_DIR_FD: bool = cfg!(any(unix, target_os = "wasi"));
     const STAT_DIR_FD: bool = cfg!(not(any(windows, target_os = "redox")));
     const UTIME_DIR_FD: bool = cfg!(not(any(windows, target_os = "redox")));
     pub(crate) const SYMLINK_DIR_FD: bool = cfg!(not(any(windows, target_os = "redox")));
@@ -338,32 +342,17 @@ pub(super) mod _os {
         }
     }
 
-    #[cfg(not(windows))]
     #[pyfunction]
     fn mkdir(
         path: OsPath,
         mode: OptionalArg<i32>,
         dir_fd: DirFd<'_, { MKDIR_DIR_FD as usize }>,
         vm: &VirtualMachine,
     ) -> PyResult<()> {
-        let mode = mode.unwrap_or(0o777);
-        let c_path = path.clone().into_cstring(vm)?;
-        #[cfg(not(target_os = "redox"))]
-        if let Some(fd) = dir_fd.raw_opt() {
-            return if let Err(err) =
-                crate::host_env::posix::make_dir_at(fd, c_path.as_c_str(), mode as u32)
-            {
-                Err(OSErrorBuilder::with_filename(&err, path, vm))
-            } else {
-                Ok(())
-            };
-        }
-        #[cfg(target_os = "redox")]
-        let [] = dir_fd.0;
-        if let Err(err) = crate::host_env::posix::make_dir(c_path.as_c_str(), mode as u32) {
-            return Err(OSErrorBuilder::with_filename(&err, path, vm));
-        }
-        Ok(())
+        let mode = mode.unwrap_or(0o777) as u32;
+        let dir_fd = dir_fd.get_opt();
+        crate::host_env::posix::make_dir(dir_fd, Path::new(&path.path), mode)
+            .map_err(|err| OSErrorBuilder::with_filename(&err, path, vm))
     }
 
     #[pyfunction]
