wasm: make ls pass and prepare more work

Cargo.toml

@@ -185,6 +185,7 @@ feat_wasm = [
   "base64",
   "basenc",
   "cut",
+  "ls",
   "date",
   "dircolors",
   "dirname",

src/uu/ls/Cargo.toml

@@ -24,7 +24,6 @@ path = "src/ls.rs"
 ansi-width = { workspace = true }
 clap = { workspace = true, features = ["env"] }
 glob = { workspace = true }
-hostname = { workspace = true }
 lscolors = { workspace = true }
 rustc-hash = { workspace = true }
 selinux = { workspace = true, optional = true }
@@ -46,6 +45,10 @@ uucore = { workspace = true, features = [
 uutils_term_grid = { workspace = true }
 fluent = { workspace = true }
 
+# hostname crate does not support WASI (no OS-level hostname API)
+[target.'cfg(not(target_os = "wasi"))'.dependencies]
+hostname = { workspace = true }
+
 [[bin]]
 name = "ls"
 path = "src/main.rs"

src/uu/ls/src/display.rs

@@ -1146,7 +1146,12 @@ fn classify_file(path: &PathData) -> Option<char> {
 }
 
 fn create_hyperlink(name: &OsStr, path: &PathData) -> OsString {
+    // The `hostname` crate does not support WASI (no OS-level hostname API),
+    // so we use an empty string for hyperlinks on WASI.
+    #[cfg(not(target_os = "wasi"))]
     static HOSTNAME: LazyLock<OsString> = LazyLock::new(|| hostname::get().unwrap_or_default());
+    #[cfg(target_os = "wasi")]
+    static HOSTNAME: LazyLock<OsString> = LazyLock::new(OsString::new);
 
     // OSC 8 hyperlink format: \x1b]8;;URL\x1b\\TEXT\x1b]8;;\x1b\\
     // \x1b = ESC, \x1b\\ = ESC backslash

src/uucore/src/lib/features/fs.rs

@@ -45,6 +45,8 @@ macro_rules! has {
 pub struct FileInformation(
     #[cfg(unix)] nix::sys::stat::FileStat,
     #[cfg(windows)] winapi_util::file::Information,
+    // WASI does not have nix::sys::stat, so we store std::fs::Metadata instead.
+    #[cfg(target_os = "wasi")] std::fs::Metadata,
 );
 
 impl FileInformation {
@@ -91,6 +93,16 @@ impl FileInformation {
             let file = open_options.read(true).open(path.as_ref())?;
             Self::from_file(&file)
         }
+        // WASI: use std::fs::metadata / symlink_metadata since nix is not available
+        #[cfg(target_os = "wasi")]
+        {
+            let metadata = if dereference {
+                std::fs::metadata(path.as_ref())
+            } else {
+                std::fs::symlink_metadata(path.as_ref())
+            };
+            Ok(Self(metadata?))
+        }
     }
 
     pub fn file_size(&self) -> u64 {
@@ -103,6 +115,10 @@ impl FileInformation {
         {
             self.0.file_size()
         }
+        #[cfg(target_os = "wasi")]
+        {
+            self.0.len()
+        }
     }
 
     #[cfg(windows)]
@@ -153,6 +169,9 @@ impl FileInformation {
         return self.0.st_nlink.try_into().unwrap();
         #[cfg(windows)]
         return self.0.number_of_links();
+        // WASI: nlink is not available in std::fs::Metadata, return 1
+        #[cfg(target_os = "wasi")]
+        return 1;
     }
 
     #[cfg(unix)]
@@ -172,6 +191,15 @@ impl PartialEq for FileInformation {
     }
 }
 
+// WASI: compare by file type and size as a basic heuristic since
+// device/inode numbers are not available through std::fs::Metadata.
+#[cfg(target_os = "wasi")]
+impl PartialEq for FileInformation {
+    fn eq(&self, other: &Self) -> bool {
+        self.0.file_type() == other.0.file_type() && self.0.len() == other.0.len()
+    }
+}
+
 #[cfg(target_os = "windows")]
 impl PartialEq for FileInformation {
     fn eq(&self, other: &Self) -> bool {
@@ -194,6 +222,10 @@ impl Hash for FileInformation {
             self.0.volume_serial_number().hash(state);
             self.0.file_index().hash(state);
         }
+        #[cfg(target_os = "wasi")]
+        {
+            self.0.len().hash(state);
+        }
     }
 }
 
@@ -778,11 +810,18 @@ pub fn is_stdin_directory(stdin: &Stdin) -> bool {
         }
         false
     }
+
+    // WASI: stdin is never a directory
+    #[cfg(target_os = "wasi")]
+    {
+        let _ = stdin;
+        false
+    }
 }
 
 pub mod sane_blksize {
 
-    #[cfg(not(target_os = "windows"))]
+    #[cfg(unix)]
     use std::os::unix::fs::MetadataExt;
     use std::{fs::metadata, path::Path};
 
@@ -809,12 +848,12 @@ pub mod sane_blksize {
         #[cfg(unix)] metadata: &std::fs::Metadata,
         #[cfg(not(unix))] _: &std::fs::Metadata,
     ) -> u64 {
-        #[cfg(not(target_os = "windows"))]
+        #[cfg(unix)]
         {
             sane_blksize(metadata.blksize())
         }
 
-        #[cfg(target_os = "windows")]
+        #[cfg(not(unix))]
         {
             DEFAULT
         }

src/uucore/src/lib/features/fsext.rs

@@ -535,10 +535,11 @@ pub fn read_fs_list() -> UResult<Vec<MountInfo>> {
         target_os = "aix",
         target_os = "redox",
         target_os = "illumos",
-        target_os = "solaris"
+        target_os = "solaris",
+        target_os = "wasi"
     ))]
     {
-        // No method to read mounts, yet
+        // No method to read mounts on these platforms
         Ok(Vec::new())
     }
 }

src/uucore/src/lib/mods/io.rs

@@ -73,10 +73,17 @@ impl OwnedFileDescriptorOrHandle {
     }
 
     /// instantiates a corresponding `Stdio`
+    #[cfg(not(target_os = "wasi"))]
     pub fn into_stdio(self) -> Stdio {
         Stdio::from(self.fx)
     }
 
+    /// WASI: Stdio::from(OwnedFd) is not available, convert via File instead.
+    #[cfg(target_os = "wasi")]
+    pub fn into_stdio(self) -> Stdio {
+        Stdio::from(File::from(self.fx))
+    }
+
     /// clones self. useful when needing another
     /// owned reference to same file
     pub fn try_clone(&self) -> io::Result<Self> {