1 files changed, 41 insertions, 3 deletions
diff --git a/third_party/rust/uniffi_bindgen/src/bindings/swift/templates/Helpers.swift b/third_party/rust/uniffi_bindgen/src/bindings/swift/templates/Helpers.swift
index a34b128e23..cfddf7b313 100644
--- a/third_party/rust/uniffi_bindgen/src/bindings/swift/templates/Helpers.swift
+++ b/third_party/rust/uniffi_bindgen/src/bindings/swift/templates/Helpers.swift
@@ -26,9 +26,17 @@ fileprivate enum UniffiInternalError: LocalizedError {
     }
 }
 
+fileprivate extension NSLock {
+    func withLock<T>(f: () throws -> T) rethrows -> T {
+        self.lock()
+        defer { self.unlock() }
+        return try f()
+    }
+}
+
 fileprivate let CALL_SUCCESS: Int8 = 0
 fileprivate let CALL_ERROR: Int8 = 1
-fileprivate let CALL_PANIC: Int8 = 2
+fileprivate let CALL_UNEXPECTED_ERROR: Int8 = 2
 fileprivate let CALL_CANCELLED: Int8 = 3
 
 fileprivate extension RustCallStatus {
@@ -81,7 +89,7 @@ private func uniffiCheckCallStatus(
                 throw UniffiInternalError.unexpectedRustCallError
             }
 
-        case CALL_PANIC:
+        case CALL_UNEXPECTED_ERROR:
             // When the rust code sees a panic, it tries to construct a RustBuffer
             // with the message.  But if that code panics, then it just sends back
             // an empty buffer.
@@ -93,9 +101,39 @@ private func uniffiCheckCallStatus(
             }
 
         case CALL_CANCELLED:
-                throw CancellationError()
+            fatalError("Cancellation not supported yet")
 
         default:
             throw UniffiInternalError.unexpectedRustCallStatusCode
     }
 }
+
+private func uniffiTraitInterfaceCall<T>(
+    callStatus: UnsafeMutablePointer<RustCallStatus>,
+    makeCall: () throws -> T,
+    writeReturn: (T) -> ()
+) {
+    do {
+        try writeReturn(makeCall())
+    } catch let error {
+        callStatus.pointee.code = CALL_UNEXPECTED_ERROR
+        callStatus.pointee.errorBuf = {{ Type::String.borrow()|lower_fn }}(String(describing: error))
+    }
+}
+
+private func uniffiTraitInterfaceCallWithError<T, E>(
+    callStatus: UnsafeMutablePointer<RustCallStatus>,
+    makeCall: () throws -> T,
+    writeReturn: (T) -> (),
+    lowerError: (E) -> RustBuffer
+) {
+    do {
+        try writeReturn(makeCall())
+    } catch let error as E {
+        callStatus.pointee.code = CALL_ERROR
+        callStatus.pointee.errorBuf = lowerError(error)
+    } catch {
+        callStatus.pointee.code = CALL_UNEXPECTED_ERROR
+        callStatus.pointee.errorBuf = {{ Type::String.borrow()|lower_fn }}(String(describing: error))
+    }
+}