1 files changed, 61 insertions, 0 deletions
diff --git a/src/libstd/sys/wasi/ext/ffi.rs b/src/libstd/sys/wasi/ext/ffi.rs
new file mode 100644
index 00000000000..07b93dd143f
--- /dev/null
+++ b/src/libstd/sys/wasi/ext/ffi.rs
@@ -0,0 +1,61 @@
+//! WASI-specific extension to the primitives in the `std::ffi` module
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+use crate::ffi::{OsStr, OsString};
+use crate::mem;
+use crate::sys::os_str::Buf;
+use crate::sys_common::{FromInner, IntoInner, AsInner};
+
+/// WASI-specific extensions to [`OsString`].
+///
+/// [`OsString`]: ../../../../std/ffi/struct.OsString.html
+#[stable(feature = "rust1", since = "1.0.0")]
+pub trait OsStringExt {
+    /// Creates an `OsString` from a byte vector.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn from_vec(vec: Vec<u8>) -> Self;
+
+    /// Yields the underlying byte vector of this `OsString`.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn into_vec(self) -> Vec<u8>;
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl OsStringExt for OsString {
+    fn from_vec(vec: Vec<u8>) -> OsString {
+        FromInner::from_inner(Buf { inner: vec })
+    }
+    fn into_vec(self) -> Vec<u8> {
+        self.into_inner().inner
+    }
+}
+
+/// WASI-specific extensions to [`OsStr`].
+///
+/// [`OsStr`]: ../../../../std/ffi/struct.OsStr.html
+#[stable(feature = "rust1", since = "1.0.0")]
+pub trait OsStrExt {
+    #[stable(feature = "rust1", since = "1.0.0")]
+    /// Creates an [`OsStr`] from a byte slice.
+    ///
+    /// [`OsStr`]: ../../../ffi/struct.OsStr.html
+    fn from_bytes(slice: &[u8]) -> &Self;
+
+    /// Gets the underlying byte view of the [`OsStr`] slice.
+    ///
+    /// [`OsStr`]: ../../../ffi/struct.OsStr.html
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn as_bytes(&self) -> &[u8];
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl OsStrExt for OsStr {
+    fn from_bytes(slice: &[u8]) -> &OsStr {
+        unsafe { mem::transmute(slice) }
+    }
+    fn as_bytes(&self) -> &[u8] {
+        &self.as_inner().inner
+    }
+}
+