rs_loader: defer temp dir cleanup to Drop (#712)

The temp directory was being removed immediately after dlopen, before
the library was unloaded. Cleanup is now deferred to the Drop impl for
MemoryRegistration, ensuring the temp dir is only removed after the
DynlinkLibrary is dropped

Co-authored-by: Raicy Augusto <raicy.augusto.rodrigues@gmail.com>

Author: RaicyAugusto

source/loaders/rs_loader/rust/compiler/src/memory.rs

@@ -28,11 +28,6 @@ impl MemoryRegistration {
             Ok(instance) => instance,
             Err(error) => return Err(RegistrationError::DynlinkError(error)),
         };
-        // cleanup temp dir
-        let mut destination = state.output.clone();
-        destination.pop();
-        std::fs::remove_dir_all(destination).expect("Unable to cleanup tempdir");
-
         Ok(MemoryRegistration {
             name,
             state,
@@ -50,3 +45,14 @@ impl MemoryRegistration {
         }
     }
 }
+
+impl Drop for MemoryRegistration {
+    fn drop(&mut self) {
+        drop(std::mem::replace(&mut self.dynlink, None));
+
+        let mut path = std::mem::take(&mut self.state.output);
+        if path.pop() {
+            let _ = std::fs::remove_dir_all(path);
+        }
+    }
+}

source/loaders/rs_loader/rust/src/lifecycle/loader.rs

@@ -32,12 +32,12 @@ impl LoadingMethod {
                 }
                 None => Err(String::from("consume_dlib was called more than once")),
             },
-            Self::Memory(MemoryRegistration { mut dynlink, .. }) => match dynlink {
-                Some(_) => {
-                    let dl = dynlink.take();
-                    Ok(dl.expect("Unexpected: Dynlink library is None"))
+            Self::Memory(mut memory) => {
+                let dl = std::mem::replace(&mut memory.dynlink, None);
+                match dl {
+                    Some(dl) => Ok(dl),
+                    None => Err(String::from("consume_dlib was called more than once")),
                 }
-                None => Err(String::from("consume_dlib was called more than once")),
             },
         }
     }