1 files changed, 106 insertions, 0 deletions
diff --git a/dom/bindings/ErrorIPCUtils.h b/dom/bindings/ErrorIPCUtils.h
new file mode 100644
index 0000000000..064d851503
--- /dev/null
+++ b/dom/bindings/ErrorIPCUtils.h
@@ -0,0 +1,106 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef IPC_ErrorIPCUtils_h
+#define IPC_ErrorIPCUtils_h
+
+#include <utility>
+
+#include "ipc/EnumSerializer.h"
+#include "ipc/IPCMessageUtils.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/ErrorResult.h"
+
+namespace IPC {
+
+template <>
+struct ParamTraits<mozilla::dom::ErrNum>
+    : public ContiguousEnumSerializer<
+          mozilla::dom::ErrNum, mozilla::dom::ErrNum(0),
+          mozilla::dom::ErrNum(mozilla::dom::Err_Limit)> {};
+
+template <>
+struct ParamTraits<mozilla::ErrorResult> {
+  typedef mozilla::ErrorResult paramType;
+
+  static void Write(MessageWriter* aWriter, const paramType& aParam) {
+    // It should be the case that mMightHaveUnreportedJSException can only be
+    // true when we're expecting a JS exception.  We cannot send such messages
+    // over the IPC channel since there is no sane way of transferring the JS
+    // value over to the other side.  Callers should never do that.
+    MOZ_ASSERT_IF(aParam.IsJSException(),
+                  aParam.mMightHaveUnreportedJSException);
+    if (aParam.IsJSException()
+#ifdef DEBUG
+        || aParam.mMightHaveUnreportedJSException
+#endif
+    ) {
+      MOZ_CRASH(
+          "Cannot encode an ErrorResult representing a Javascript exception");
+    }
+
+    WriteParam(aWriter, aParam.mResult);
+    WriteParam(aWriter, aParam.IsErrorWithMessage());
+    WriteParam(aWriter, aParam.IsDOMException());
+    if (aParam.IsErrorWithMessage()) {
+      aParam.SerializeMessage(aWriter);
+    } else if (aParam.IsDOMException()) {
+      aParam.SerializeDOMExceptionInfo(aWriter);
+    }
+  }
+
+  static void Write(MessageWriter* aWriter, paramType&& aParam) {
+    Write(aWriter, static_cast<const paramType&>(aParam));
+    aParam.SuppressException();
+  }
+
+  static bool Read(MessageReader* aReader, paramType* aResult) {
+    paramType readValue;
+    if (!ReadParam(aReader, &readValue.mResult)) {
+      return false;
+    }
+    bool hasMessage = false;
+    if (!ReadParam(aReader, &hasMessage)) {
+      return false;
+    }
+    bool hasDOMExceptionInfo = false;
+    if (!ReadParam(aReader, &hasDOMExceptionInfo)) {
+      return false;
+    }
+    if (hasMessage && hasDOMExceptionInfo) {
+      // Shouldn't have both!
+      return false;
+    }
+    if (hasMessage && !readValue.DeserializeMessage(aReader)) {
+      return false;
+    } else if (hasDOMExceptionInfo &&
+               !readValue.DeserializeDOMExceptionInfo(aReader)) {
+      return false;
+    }
+    *aResult = std::move(readValue);
+    return true;
+  }
+};
+
+template <>
+struct ParamTraits<mozilla::CopyableErrorResult> {
+  typedef mozilla::CopyableErrorResult paramType;
+
+  static void Write(MessageWriter* aWriter, const paramType& aParam) {
+    ParamTraits<mozilla::ErrorResult>::Write(aWriter, aParam);
+  }
+
+  static bool Read(MessageReader* aReader, paramType* aResult) {
+    // We can't cast *aResult to ErrorResult&, so cheat and just cast
+    // to ErrorResult*.
+    return ParamTraits<mozilla::ErrorResult>::Read(
+        aReader, reinterpret_cast<mozilla::ErrorResult*>(aResult));
+  }
+};
+
+}  // namespace IPC
+
+#endif