Proxy deinit error

packages/pigeon/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 26.1.2
+
+* [swift] Adds a do/catch when a deallocated object calls back to Dart to prevent a crash.
+
 ## 26.1.1
 
 * Updates supported `analyzer` versions to 8.x or 9.x.

packages/pigeon/lib/src/generator_tools.dart

@@ -15,7 +15,7 @@ import 'generator.dart';
 /// The current version of pigeon.
 ///
 /// This must match the version in pubspec.yaml.
-const String pigeonVersion = '26.1.1';
+const String pigeonVersion = '26.1.2';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {

packages/pigeon/lib/src/swift/swift_generator.dart

@@ -1997,7 +1997,7 @@ func deepHash${generatorOptions.fileSpecificClassNameComponent}(value: Any?, has
             self.api = api
           }
 
-          public func onDeinit(identifier: Int64) {
+          public func onDeinit(identifier: Int64) throws {
             api.removeStrongReference(identifier: identifier) {
               _ in
             }

packages/pigeon/lib/src/swift/templates.dart

@@ -28,7 +28,7 @@ String instanceManagerFinalizerDelegateTemplate(InternalSwiftOptions options) =>
 /// Handles the callback when an object is deallocated.
 protocol ${instanceManagerFinalizerDelegateName(options)}: AnyObject {
   /// Invoked when the strong reference of an object is deallocated in an `InstanceManager`.
-  func onDeinit(identifier: Int64)
+  func onDeinit(identifier: Int64) throws
 }
 
 ''';
@@ -66,7 +66,13 @@ internal final class ${_instanceManagerFinalizerName(options)} {
   }
 
   deinit {
-    delegate?.onDeinit(identifier: identifier)
+    do {
+      try delegate?.onDeinit(identifier: identifier)
+    } catch {
+      NSLog(
+        "Failed to call `onDeinit` on object with identifier: \\(identifier)\\n\\(error)\\nStacktrace: \\(Thread.callStackSymbols)"
+      )
+    }
   }
 }
 

packages/pigeon/platform_tests/test_plugin/darwin/test_plugin/Sources/test_plugin/ProxyApiTests.gen.swift

@@ -77,7 +77,7 @@ private func nilOrValue<T>(_ value: Any?) -> T? {
 /// Handles the callback when an object is deallocated.
 protocol ProxyApiTestsPigeonInternalFinalizerDelegate: AnyObject {
   /// Invoked when the strong reference of an object is deallocated in an `InstanceManager`.
-  func onDeinit(identifier: Int64)
+  func onDeinit(identifier: Int64) throws
 }
 
 // Attaches to an object to receive a callback when the object is deallocated.
@@ -113,7 +113,13 @@ internal final class ProxyApiTestsPigeonInternalFinalizer {
   }
 
   deinit {
-    delegate?.onDeinit(identifier: identifier)
+    do {
+      try delegate?.onDeinit(identifier: identifier)
+    } catch {
+      NSLog(
+        "Failed to call `onDeinit` on object with identifier: \(identifier)\n\(error)\nStacktrace: \(Thread.callStackSymbols)"
+      )
+    }
   }
 }
 
@@ -428,7 +434,7 @@ open class ProxyApiTestsPigeonProxyApiRegistrar {
       self.api = api
     }
 
-    public func onDeinit(identifier: Int64) {
+    public func onDeinit(identifier: Int64) throws {
       api.removeStrongReference(identifier: identifier) {
         _ in
       }

packages/pigeon/platform_tests/test_plugin/example/ios/RunnerTests/InstanceManagerTests.swift

@@ -147,6 +147,17 @@ final class InstanceManagerTests: XCTestCase {
     XCTAssertNil(
       objc_getAssociatedObject(object!, ProxyApiTestsPigeonInternalFinalizer.associatedObjectKey))
   }
+
+  func testExceptionInDeinitDoesNotCauseCrash() {
+    let finalizerDelegate = ThrowingFinalizerDelegate()
+
+    var object: NSObject? = NSObject()
+    ProxyApiTestsPigeonInternalFinalizer.attach(
+      to: object!, identifier: 0, delegate: finalizerDelegate)
+
+    XCTAssertNoThrow(object = nil)
+    XCTAssertTrue(finalizerDelegate.deinitCalled)
+  }
 }
 
 class EmptyFinalizerDelegate: ProxyApiTestsPigeonInternalFinalizerDelegate {
@@ -160,3 +171,12 @@ class TestFinalizerDelegate: ProxyApiTestsPigeonInternalFinalizerDelegate {
     lastHandledIdentifier = identifier
   }
 }
+
+class ThrowingFinalizerDelegate: ProxyApiTestsPigeonInternalFinalizerDelegate {
+  var deinitCalled = false
+
+  func onDeinit(identifier: Int64) throws {
+    deinitCalled = true
+    fatalError()
+  }
+}

packages/pigeon/pubspec.yaml

@@ -2,7 +2,7 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+pigeon%22
-version: 26.1.1 # This must match the version in lib/src/generator_tools.dart
+version: 26.1.2 # This must match the version in lib/src/generator_tools.dart
 
 environment:
   sdk: ^3.8.0