fs: use cfgs on fns instead of OS ext traits

tokio/src/fs/dir_builder.rs

@@ -5,14 +5,10 @@ use std::path::Path;
 
 /// A builder for creating directories in various manners.
 ///
-/// Additional Unix-specific options are available via importing the
-/// [`DirBuilderExt`] trait.
-///
 /// This is a specialized version of [`std::fs::DirBuilder`] for usage on
 /// the Tokio runtime.
 ///
 /// [std::fs::DirBuilder]: std::fs::DirBuilder
-/// [`DirBuilderExt`]: crate::fs::os::unix::DirBuilderExt
 #[derive(Debug, Default)]
 pub struct DirBuilder {
     /// Indicates whether to create parent directories if they are missing.
@@ -115,3 +111,27 @@ impl DirBuilder {
         asyncify(move || builder.create(path)).await
     }
 }
+
+feature! {
+    #![unix]
+
+    impl DirBuilder {
+        /// Sets the mode to create new directories with.
+        ///
+        /// This option defaults to 0o777.
+        ///
+        /// # Examples
+        ///
+        ///
+        /// ```no_run
+        /// use tokio::fs::DirBuilder;
+        ///
+        /// let mut builder = DirBuilder::new();
+        /// builder.mode(0o775);
+        /// ```
+        pub fn mode(&mut self, mode: u32) -> &mut Self {
+            self.mode = Some(mode);
+            self
+        }
+    }
+}

tokio/src/fs/mod.rs

@@ -48,8 +48,6 @@ pub use self::metadata::metadata;
 mod open_options;
 pub use self::open_options::OpenOptions;
 
-pub mod os;
-
 mod read;
 pub use self::read::read;
 
@@ -86,6 +84,23 @@ pub use self::write::write;
 mod copy;
 pub use self::copy::copy;
 
+feature! {
+    #![unix]
+
+    mod symlink;
+    pub use self::symlink::symlink;
+}
+
+feature! {
+    #![windows]
+
+    mod symlink_dir;
+    pub use self::symlink_dir::symlink_dir;
+
+    mod symlink_file;
+    pub use self::symlink_file::symlink_file;
+}
+
 use std::io;
 
 pub(crate) async fn asyncify<F, T>(f: F) -> io::Result<T>

tokio/src/fs/open_options.rs

@@ -389,6 +389,262 @@ impl OpenOptions {
     }
 }
 
+feature! {
+    #![unix]
+
+    use std::os::unix::fs::OpenOptionsExt;
+
+    impl OpenOptions {
+        /// Sets the mode bits that a new file will be created with.
+        ///
+        /// If a new file is created as part of an `OpenOptions::open` call then this
+        /// specified `mode` will be used as the permission bits for the new file.
+        /// If no `mode` is set, the default of `0o666` will be used.
+        /// The operating system masks out bits with the system's `umask`, to produce
+        /// the final permissions.
+        ///
+        /// # Examples
+        ///
+        /// ```no_run
+        /// use tokio::fs::OpenOptions;
+        /// use std::io;
+        ///
+        /// #[tokio::main]
+        /// async fn main() -> io::Result<()> {
+        ///     let mut options = OpenOptions::new();
+        ///     options.mode(0o644); // Give read/write for owner and read for others.
+        ///     let file = options.open("foo.txt").await?;
+        ///
+        ///     Ok(())
+        /// }
+        /// ```
+        pub fn mode(&mut self, mode: u32) -> &mut OpenOptions {
+            self.as_inner_mut().mode(mode);
+            self
+        }
+
+        /// Pass custom flags to the `flags` argument of `open`.
+        ///
+        /// The bits that define the access mode are masked out with `O_ACCMODE`, to
+        /// ensure they do not interfere with the access mode set by Rusts options.
+        ///
+        /// Custom flags can only set flags, not remove flags set by Rusts options.
+        /// This options overwrites any previously set custom flags.
+        ///
+        /// # Examples
+        ///
+        /// ```no_run
+        /// use libc;
+        /// use tokio::fs::OpenOptions;
+        /// use std::io;
+        ///
+        /// #[tokio::main]
+        /// async fn main() -> io::Result<()> {
+        ///     let mut options = OpenOptions::new();
+        ///     options.write(true);
+        ///     if cfg!(unix) {
+        ///         options.custom_flags(libc::O_NOFOLLOW);
+        ///     }
+        ///     let file = options.open("foo.txt").await?;
+        ///
+        ///     Ok(())
+        /// }
+        /// ```
+        pub fn custom_flags(&mut self, flags: i32) -> &mut OpenOptions {
+            self.as_inner_mut().custom_flags(flags);
+            self
+        }
+    }
+}
+
+feature! {
+    #![windows]
+
+    use std::os::windows::fs::OpenOptionsExt;
+
+    impl OpenOptions {
+        /// Overrides the `dwDesiredAccess` argument to the call to [`CreateFile`]
+        /// with the specified value.
+        ///
+        /// This will override the `read`, `write`, and `append` flags on the
+        /// `OpenOptions` structure. This method provides fine-grained control over
+        /// the permissions to read, write and append data, attributes (like hidden
+        /// and system), and extended attributes.
+        ///
+        /// # Examples
+        ///
+        /// ```no_run
+        /// use tokio::fs::OpenOptions;
+        ///
+        /// # #[tokio::main]
+        /// # async fn main() -> std::io::Result<()> {
+        /// // Open without read and write permission, for example if you only need
+        /// // to call `stat` on the file
+        /// let file = OpenOptions::new().access_mode(0).open("foo.txt").await?;
+        /// # Ok(())
+        /// # }
+        /// ```
+        ///
+        /// [`CreateFile`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea
+        pub fn access_mode(&mut self, access: u32) -> &mut OpenOptions {
+            self.as_inner_mut().access_mode(access);
+            self
+        }
+
+        /// Overrides the `dwShareMode` argument to the call to [`CreateFile`] with
+        /// the specified value.
+        ///
+        /// By default `share_mode` is set to
+        /// `FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE`. This allows
+        /// other processes to read, write, and delete/rename the same file
+        /// while it is open. Removing any of the flags will prevent other
+        /// processes from performing the corresponding operation until the file
+        /// handle is closed.
+        ///
+        /// # Examples
+        ///
+        /// ```no_run
+        /// use tokio::fs::OpenOptions;
+        ///
+        /// # #[tokio::main]
+        /// # async fn main() -> std::io::Result<()> {
+        /// // Do not allow others to read or modify this file while we have it open
+        /// // for writing.
+        /// let file = OpenOptions::new()
+        ///     .write(true)
+        ///     .share_mode(0)
+        ///     .open("foo.txt").await?;
+        /// # Ok(())
+        /// # }
+        /// ```
+        ///
+        /// [`CreateFile`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea
+        pub fn share_mode(&mut self, share: u32) -> &mut OpenOptions {
+            self.as_inner_mut().share_mode(share);
+            self
+        }
+
+        /// Sets extra flags for the `dwFileFlags` argument to the call to
+        /// [`CreateFile2`] to the specified value (or combines it with
+        /// `attributes` and `security_qos_flags` to set the `dwFlagsAndAttributes`
+        /// for [`CreateFile`]).
+        ///
+        /// Custom flags can only set flags, not remove flags set by Rust's options.
+        /// This option overwrites any previously set custom flags.
+        ///
+        /// # Examples
+        ///
+        /// ```no_run
+        /// use winapi::um::winbase::FILE_FLAG_DELETE_ON_CLOSE;
+        /// use tokio::fs::OpenOptions;
+        ///
+        /// # #[tokio::main]
+        /// # async fn main() -> std::io::Result<()> {
+        /// let file = OpenOptions::new()
+        ///     .create(true)
+        ///     .write(true)
+        ///     .custom_flags(FILE_FLAG_DELETE_ON_CLOSE)
+        ///     .open("foo.txt").await?;
+        /// # Ok(())
+        /// # }
+        /// ```
+        ///
+        /// [`CreateFile`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea
+        /// [`CreateFile2`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfile2
+        pub fn custom_flags(&mut self, flags: u32) -> &mut OpenOptions {
+            self.as_inner_mut().custom_flags(flags);
+            self
+        }
+
+        /// Sets the `dwFileAttributes` argument to the call to [`CreateFile2`] to
+        /// the specified value (or combines it with `custom_flags` and
+        /// `security_qos_flags` to set the `dwFlagsAndAttributes` for
+        /// [`CreateFile`]).
+        ///
+        /// If a _new_ file is created because it does not yet exist and
+        /// `.create(true)` or `.create_new(true)` are specified, the new file is
+        /// given the attributes declared with `.attributes()`.
+        ///
+        /// If an _existing_ file is opened with `.create(true).truncate(true)`, its
+        /// existing attributes are preserved and combined with the ones declared
+        /// with `.attributes()`.
+        ///
+        /// In all other cases the attributes get ignored.
+        ///
+        /// # Examples
+        ///
+        /// ```no_run
+        /// use winapi::um::winnt::FILE_ATTRIBUTE_HIDDEN;
+        /// use tokio::fs::OpenOptions;
+        ///
+        /// # #[tokio::main]
+        /// # async fn main() -> std::io::Result<()> {
+        /// let file = OpenOptions::new()
+        ///     .write(true)
+        ///     .create(true)
+        ///     .attributes(FILE_ATTRIBUTE_HIDDEN)
+        ///     .open("foo.txt").await?;
+        /// # Ok(())
+        /// # }
+        /// ```
+        ///
+        /// [`CreateFile`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea
+        /// [`CreateFile2`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfile2
+        pub fn attributes(&mut self, attributes: u32) -> &mut OpenOptions {
+            self.as_inner_mut().attributes(attributes);
+            self
+        }
+
+        /// Sets the `dwSecurityQosFlags` argument to the call to [`CreateFile2`] to
+        /// the specified value (or combines it with `custom_flags` and `attributes`
+        /// to set the `dwFlagsAndAttributes` for [`CreateFile`]).
+        ///
+        /// By default `security_qos_flags` is not set. It should be specified when
+        /// opening a named pipe, to control to which degree a server process can
+        /// act on behalf of a client process (security impersonation level).
+        ///
+        /// When `security_qos_flags` is not set, a malicious program can gain the
+        /// elevated privileges of a privileged Rust process when it allows opening
+        /// user-specified paths, by tricking it into opening a named pipe. So
+        /// arguably `security_qos_flags` should also be set when opening arbitrary
+        /// paths. However the bits can then conflict with other flags, specifically
+        /// `FILE_FLAG_OPEN_NO_RECALL`.
+        ///
+        /// For information about possible values, see [Impersonation Levels] on the
+        /// Windows Dev Center site. The `SECURITY_SQOS_PRESENT` flag is set
+        /// automatically when using this method.
+        ///
+        /// # Examples
+        ///
+        /// ```no_run
+        /// use winapi::um::winbase::SECURITY_IDENTIFICATION;
+        /// use tokio::fs::OpenOptions;
+        ///
+        /// # #[tokio::main]
+        /// # async fn main() -> std::io::Result<()> {
+        /// let file = OpenOptions::new()
+        ///     .write(true)
+        ///     .create(true)
+        ///
+        ///     // Sets the flag value to `SecurityIdentification`.
+        ///     .security_qos_flags(SECURITY_IDENTIFICATION)
+        ///
+        ///     .open(r"\\.\pipe\MyPipe").await?;
+        /// # Ok(())
+        /// # }
+        /// ```
+        ///
+        /// [`CreateFile`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea
+        /// [`CreateFile2`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfile2
+        /// [Impersonation Levels]:
+        ///     https://docs.microsoft.com/en-us/windows/win32/api/winnt/ne-winnt-security_impersonation_level
+        pub fn security_qos_flags(&mut self, flags: u32) -> &mut OpenOptions {
+            self.as_inner_mut().security_qos_flags(flags);
+            self
+        }
+    }
+}
+
 impl From<std::fs::OpenOptions> for OpenOptions {
     fn from(options: std::fs::OpenOptions) -> OpenOptions {
         OpenOptions(options)