Auto merge of #1015 - brson:remove_dir_all, r=brson

Aggressive remove_dir_all

Let's see if this helps the flakiness.

cc @Diggsey @alexcrichton

cc @Aaronepower this PR contains a self-contained remove_dir_all module based on winapi.

src/rustup-utils/Cargo.toml

@@ -22,6 +22,7 @@ url = "1.1"
 toml = "0.1.27"
 semver = "0.4.0"
 download = { path = "../download" }
+lazy_static = "0.1.15"
 
 [target."cfg(windows)".dependencies]
 winapi = "0.2.8"

src/rustup-utils/src/lib.rs

@@ -10,6 +10,8 @@ extern crate url;
 extern crate toml;
 extern crate download;
 extern crate semver;
+#[macro_use]
+extern crate lazy_static;
 
 #[cfg(windows)]
 extern crate winapi;
@@ -35,6 +37,7 @@ pub mod raw;
 pub mod tty;
 pub mod utils;
 pub mod toml_utils;
+mod remove_dir_all;
 
 pub use errors::*;
 pub use notifications::{Notification};

src/rustup-utils/src/raw.rs

@@ -320,54 +320,11 @@ pub fn remove_dir(path: &Path) -> io::Result<()> {
             fs::remove_file(path)
         }
     } else {
-        let mut result = Ok(());
-
-        // The implementation of `remove_dir_all` is broken on windows,
-        // so may need to try multiple times!
-        for _ in 0..5 {
-            result = rm_rf(path);
-            if !is_directory(path) {
-                return Ok(());
-            }
-            thread::sleep(Duration::from_millis(16));
-        }
-        result
-    }
-}
-
-// Again because remove_dir all doesn't delete write-only files on windows,
-// this is a custom implementation, more-or-less copied from cargo.
-// cc rust-lang/rust#31944
-// cc https://github.com/rust-lang/cargo/blob/master/tests/support/paths.rs#L52-L80
-fn rm_rf(path: &Path) -> io::Result<()> {
-    if path.exists() {
-        for file in fs::read_dir(path).unwrap() {
-            let file = try!(file);
-            let is_dir = try!(file.file_type()).is_dir();
-            let ref file = file.path();
-
-            if is_dir {
-                try!(rm_rf(file));
-            } else {
-                // On windows we can't remove a readonly file, and git will
-                // often clone files as readonly. As a result, we have some
-                // special logic to remove readonly files on windows.
-                match fs::remove_file(file) {
-                    Ok(()) => {}
-                    Err(ref e) if cfg!(windows) &&
-                        e.kind() == io::ErrorKind::PermissionDenied => {
-                            let mut p = file.metadata().unwrap().permissions();
-                            p.set_readonly(false);
-                            fs::set_permissions(file, p).unwrap();
-                            try!(fs::remove_file(file));
-                        }
-                    Err(e) => return Err(e)
-                }
-            }
-        }
-        fs::remove_dir(path)
-    } else {
-        Ok(())
+        // Again because remove_dir all doesn't delete write-only files on windows,
+        // this is a custom implementation, more-or-less copied from cargo.
+        // cc rust-lang/rust#31944
+        // cc https://github.com/rust-lang/cargo/blob/master/tests/support/paths.rs#L52
+        ::remove_dir_all::remove_dir_all(path)
     }
 }