std: sys: pal: uefi: os: Implement split_paths

- Tested using OVMF on QEMU

Signed-off-by: Ayush Singh <ayush@beagleboard.org>

Author: Ayush1325

library/std/src/sys/pal/uefi/os.rs

@@ -3,7 +3,6 @@ use r_efi::efi::protocols::{device_path, loaded_image_device_path};
 
 use super::{helpers, unsupported_err};
 use crate::ffi::{OsStr, OsString};
-use crate::marker::PhantomData;
 use crate::os::uefi;
 use crate::os::uefi::ffi::{OsStrExt, OsStringExt};
 use crate::path::{self, PathBuf};
@@ -41,16 +40,29 @@ pub fn chdir(p: &path::Path) -> io::Result<()> {
     if r.is_error() { Err(io::Error::from_raw_os_error(r.as_usize())) } else { Ok(()) }
 }
 
-pub struct SplitPaths<'a>(!, PhantomData<&'a ()>);
+pub struct SplitPaths<'a>(crate::os::uefi::ffi::EncodeWide<'a>);
 
-pub fn split_paths(_unparsed: &OsStr) -> SplitPaths<'_> {
-    panic!("unsupported")
+pub fn split_paths(unparsed: &OsStr) -> SplitPaths<'_> {
+    SplitPaths(unparsed.encode_wide())
 }
 
 impl<'a> Iterator for SplitPaths<'a> {
     type Item = PathBuf;
     fn next(&mut self) -> Option<PathBuf> {
-        self.0
+        let mut buf = Vec::new();
+
+        loop {
+            match self.0.next() {
+                // Ignore consecutive sepearators
+                Some(ch) if ch == PATHS_SEP && buf.is_empty() => {}
+                Some(ch) if ch == PATHS_SEP => break,
+                Some(ch) => buf.push(ch),
+                None if buf.is_empty() => return None,
+                None => break,
+            }
+        }
+
+        Some(PathBuf::from(OsString::from_wide(&buf)))
     }
 }