Try symlinking proxies first, falling back to hardlinking if that fails

src/cli/self_update.rs

@@ -731,8 +731,8 @@ pub(crate) fn install_proxies(process: &Process) -> Result<()> {
     let mut tool_handles = Vec::new();
     let mut link_afterwards = Vec::new();
 
-    // Try to hardlink all the Rust exes to the rustup exe. Some systems,
-    // like Android, does not support hardlinks, so we fallback to symlinks.
+    // Try to symlink all the Rust exes to the rustup exe. Some systems,
+    // like Windows, do not always support symlinks, so we fallback to hard links.
     //
     // Note that this function may not be running in the context of a fresh
     // self update but rather as part of a normal update to fill in missing
@@ -751,7 +751,7 @@ pub(crate) fn install_proxies(process: &Process) -> Result<()> {
     // actually delete files (they'll say they're deleted but they won't
     // actually be on Windows). As a result we manually drop all the
     // `tool_handles` later on. This'll allow us, afterwards, to actually
-    // overwrite all the previous hard links with new ones.
+    // overwrite all the previous soft or hard links with new ones.
     for tool in TOOLS {
         let tool_path = bin_path.join(format!("{tool}{EXE_SUFFIX}"));
         if let Ok(handle) = Handle::from_path(&tool_path) {
@@ -766,7 +766,7 @@ pub(crate) fn install_proxies(process: &Process) -> Result<()> {
     for tool in DUP_TOOLS {
         let tool_path = bin_path.join(format!("{tool}{EXE_SUFFIX}"));
         if let Ok(handle) = Handle::from_path(&tool_path) {
-            // Like above, don't clobber anything that's already hardlinked to
+            // Like above, don't clobber anything that's already linked to
             // avoid extraneous errors from being returned.
             if rustup == handle {
                 continue;
@@ -790,12 +790,12 @@ pub(crate) fn install_proxies(process: &Process) -> Result<()> {
                 continue;
             }
         }
-        utils::hard_or_symlink_file(&rustup_path, &tool_path)?;
+        utils::symlink_or_hardlink_file(&rustup_path, &tool_path)?;
     }
 
     drop(tool_handles);
     for path in link_afterwards {
-        utils::hard_or_symlink_file(&rustup_path, &path)?;
+        utils::symlink_or_hardlink_file(&rustup_path, &path)?;
     }
 
     Ok(())

src/utils/raw.rs

@@ -226,11 +226,6 @@ fn symlink_junction_inner(target: &Path, junction: &Path) -> io::Result<()> {
     }
 }
 
-pub(crate) fn hardlink(src: &Path, dest: &Path) -> io::Result<()> {
-    let _ = fs::remove_file(dest);
-    fs::hard_link(src, dest)
-}
-
 pub fn remove_dir(path: &Path) -> io::Result<()> {
     if fs::symlink_metadata(path)?.file_type().is_symlink() {
         #[cfg(windows)]

src/utils/utils.rs

@@ -312,23 +312,31 @@ where
     })
 }
 
-pub(crate) fn hard_or_symlink_file(src: &Path, dest: &Path) -> Result<()> {
+/// Attempts to symlink a file, falling back to hard linking if that fails.
+///
+/// If `dest` already exists then it will be replaced.
+pub(crate) fn symlink_or_hardlink_file(src: &Path, dest: &Path) -> Result<()> {
+    let _ = fs::remove_file(dest);
+    // The error is only used by macos
+    let Err(_err) = symlink_file(src, dest) else {
+        return Ok(());
+    };
+
     // Some mac filesystems can do hardlinks to symlinks, some can't.
     // See rust-lang/rustup#3136 for why it's better never to use them.
     #[cfg(target_os = "macos")]
-    let force_symlink = fs::symlink_metadata(src)
+    if fs::symlink_metadata(src)
         .map(|m| m.file_type().is_symlink())
-        .unwrap_or(false);
-    #[cfg(not(target_os = "macos"))]
-    let force_symlink = false;
-    if force_symlink || hardlink_file(src, dest).is_err() {
-        symlink_file(src, dest)?;
+        .unwrap_or(false)
+    {
+        return Err(_err);
     }
-    Ok(())
+
+    hardlink_file(src, dest)
 }
 
 pub fn hardlink_file(src: &Path, dest: &Path) -> Result<()> {
-    raw::hardlink(src, dest).with_context(|| RustupError::LinkingFile {
+    fs::hard_link(src, dest).with_context(|| RustupError::LinkingFile {
         src: PathBuf::from(src),
         dest: PathBuf::from(dest),
     })
@@ -344,11 +352,10 @@ fn symlink_file(src: &Path, dest: &Path) -> Result<()> {
 
 #[cfg(windows)]
 fn symlink_file(src: &Path, dest: &Path) -> Result<()> {
-    // we are supposed to not use symlink on windows
-    Err(anyhow!(RustupError::LinkingFile {
+    std::os::windows::fs::symlink_file(src, dest).with_context(|| RustupError::LinkingFile {
         src: PathBuf::from(src),
         dest: PathBuf::from(dest),
-    }))
+    })
 }
 
 pub(crate) fn copy_dir<'a, N>(