1 files changed, 30 insertions, 0 deletions
diff --git a/third_party/rust/objc/src/rc/autorelease.rs b/third_party/rust/objc/src/rc/autorelease.rs
new file mode 100644
index 0000000000..ad7a5e2847
--- /dev/null
+++ b/third_party/rust/objc/src/rc/autorelease.rs
@@ -0,0 +1,30 @@
+use std::os::raw::c_void;
+use runtime::{objc_autoreleasePoolPush, objc_autoreleasePoolPop};
+
+// we use a struct to ensure that objc_autoreleasePoolPop during unwinding.
+struct AutoReleaseHelper {
+    context: *mut c_void,
+}
+
+impl AutoReleaseHelper {
+    unsafe fn new() -> Self {
+        AutoReleaseHelper { context: objc_autoreleasePoolPush() }
+    }
+}
+
+impl Drop for AutoReleaseHelper {
+    fn drop(&mut self) {
+        unsafe { objc_autoreleasePoolPop(self.context) }
+    }
+}
+
+/**
+Execute `f` in the context of a new autorelease pool. The pool is drained
+after the execution of `f` completes.
+
+This corresponds to `@autoreleasepool` blocks in Objective-C and Swift.
+*/
+pub fn autoreleasepool<T, F: FnOnce() -> T>(f: F) -> T {
+    let _context = unsafe { AutoReleaseHelper::new() };
+    f()
+}