Fix Windows "access is denied" removing a dangling symlink

gen/build/src/out.rs

@@ -86,24 +86,34 @@ pub(crate) fn symlink_dir(original: impl AsRef<Path>, link: impl AsRef<Path>) ->
 fn best_effort_remove(path: &Path) {
  use std::fs;
 
- let file_type = match if cfg!(windows) {
+ if cfg!(windows) {
  // On Windows, the correct choice of remove_file vs remove_dir needs to
  // be used according to what the symlink *points to*. Trying to use
  // remove_file to remove a symlink which points to a directory fails
  // with "Access is denied".
- fs::metadata(path).or_else(|_| fs::symlink_metadata(path))
+ if let Ok(metadata) = fs::metadata(path) {
+ if metadata.is_dir() {
+ let _ = fs::remove_dir_all(path);
+ } else {
+ let _ = fs::remove_file(path);
+ }
+ } else if fs::symlink_metadata(path).is_ok() {
+ // The symlink might exist but be dangling, in which case there is
+ // no standard way to determine what "kind" of symlink it is. Try
+ // deleting both ways.
+ if fs::remove_dir_all(path).is_err() {
+ let _ = fs::remove_file(path);
+ }
+ }
  } else {
  // On non-Windows, we check metadata not following symlinks. All
  // symlinks are removed using remove_file.
- fs::symlink_metadata(path)
- } {
- Ok(metadata) => metadata.file_type(),
- Err(_) => return,
- };
-
- if file_type.is_dir() {
- let _ = fs::remove_dir_all(path);
- } else {
- let _ = fs::remove_file(path);
+ if let Ok(metadata) = fs::symlink_metadata(path) {
+ if metadata.is_dir() {
+ let _ = fs::remove_dir_all(path);
+ } else {
+ let _ = fs::remove_file(path);
+ }
+ }
  }
 }