gecko-dev/dom/bindings/ErrorIPCUtils.h

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/* -*- 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