bindings: Add a macro for V8 Maybe<T> APIs.

Source/bindings/modules/v8/custom/V8DeviceMotionEventCustom.cpp

 /*
  * Copyright (C) 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *  * Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  *  * Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 21 matching lines @@
 
 namespace blink {
 
 namespace {
 
 DeviceMotionData::Acceleration* readAccelerationArgument(v8::Local<v8::Value> value, v8::Isolate* isolate)
 {
     if (isUndefinedOrNull(value))
         return nullptr;
 
+    v8::Local<v8::Context> context = isolate->GetCurrentContext();
     v8::Local<v8::Object> object;
-    if (!value->ToObject(isolate->GetCurrentContext()).ToLocal(&object))
+    if (!value->ToObject(context).ToLocal(&object))
         return nullptr;
 
     v8::Local<v8::Value> xValue = object->Get(v8AtomicString(isolate, "x"));
     if (xValue.IsEmpty())
         return nullptr;
     bool canProvideX = !isUndefinedOrNull(xValue);
-    double x = xValue->NumberValue();
+    double x;
+    V8_MAYBE(x, xValue, NumberValue(context), return nullptr);

[haraken, 2015/03/11 02:43:21]

I might want to have a better name for the macro though.

V8_CALL or V8_CALL_WITH_EMPTY_CHECK?

[bashi, 2015/03/11 03:46:27]

Changed to V8_CALL(). (This sounds a bit too generic, but I'd want to keep the
name as short as possible)

 
     v8::Local<v8::Value> yValue = object->Get(v8AtomicString(isolate, "y"));
     if (yValue.IsEmpty())
         return nullptr;
     bool canProvideY = !isUndefinedOrNull(yValue);
-    double y = yValue->NumberValue();
+    double y;
+    V8_MAYBE(y, yValue, NumberValue(context), return nullptr);
 
     v8::Local<v8::Value> zValue = object->Get(v8AtomicString(isolate, "z"));
     if (zValue.IsEmpty())
         return nullptr;
     bool canProvideZ = !isUndefinedOrNull(zValue);
-    double z = zValue->NumberValue();
+    double z;
+    V8_MAYBE(z, zValue, NumberValue(context), return nullptr);
 
     if (!canProvideX && !canProvideY && !canProvideZ)
         return nullptr;
 
     return DeviceMotionData::Acceleration::create(canProvideX, x, canProvideY, y, canProvideZ, z);
 }
 
 DeviceMotionData::RotationRate* readRotationRateArgument(v8::Local<v8::Value> value, v8::Isolate* isolate)
 {
     if (isUndefinedOrNull(value))
         return nullptr;
 
+    v8::Local<v8::Context> context = isolate->GetCurrentContext();
     v8::Local<v8::Object> object;
-    if (!value->ToObject(isolate->GetCurrentContext()).ToLocal(&object))
+    if (!value->ToObject(context).ToLocal(&object))
         return nullptr;
 
     v8::Local<v8::Value> alphaValue = object->Get(v8AtomicString(isolate, "alpha"));
     if (alphaValue.IsEmpty())
         return nullptr;
     bool canProvideAlpha = !isUndefinedOrNull(alphaValue);
-    double alpha = alphaValue->NumberValue();
+    double alpha;
+    V8_MAYBE(alpha, alphaValue, NumberValue(context), return nullptr);
 
     v8::Local<v8::Value> betaValue = object->Get(v8AtomicString(isolate, "beta"));
     if (betaValue.IsEmpty())
         return nullptr;
     bool canProvideBeta = !isUndefinedOrNull(betaValue);
-    double beta = betaValue->NumberValue();
+    double beta;
+    V8_MAYBE(beta, betaValue, NumberValue(context), return nullptr);
 
     v8::Local<v8::Value> gammaValue = object->Get(v8AtomicString(isolate, "gamma"));
     if (gammaValue.IsEmpty())
         return nullptr;
     bool canProvideGamma = !isUndefinedOrNull(gammaValue);
-    double gamma = gammaValue->NumberValue();
+    double gamma;
+    V8_MAYBE(gamma, gammaValue, NumberValue(context), return nullptr);
 
     if (!canProvideAlpha && !canProvideBeta && !canProvideGamma)
         return nullptr;
 
     return DeviceMotionData::RotationRate::create(canProvideAlpha, alpha, canProvideBeta, beta, canProvideGamma, gamma);
 }
 
 } // namespace
 
 void V8DeviceMotionEvent::initDeviceMotionEventMethodCustom(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "initDeviceMotionEvent", "DeviceMotionEvent", info.Holder(), info.GetIsolate());
     DeviceMotionEvent* impl = V8DeviceMotionEvent::toImpl(info.Holder());
     v8::Isolate* isolate = info.GetIsolate();
     V8StringResource<> type(info[0]);
     if (!type.prepare())
         return;
-    bool bubbles = info[1]->BooleanValue();
-    bool cancelable = info[2]->BooleanValue();
+    v8::Local<v8::Context> context = info.GetIsolate()->GetCurrentContext();
+    bool bubbles;
+    V8_MAYBE(bubbles, info[1], BooleanValue(context), return);
+    bool cancelable;
+    V8_MAYBE(cancelable, info[2], BooleanValue(context), return);
     DeviceMotionData::Acceleration* acceleration = readAccelerationArgument(info[3], isolate);
     DeviceMotionData::Acceleration* accelerationIncludingGravity = readAccelerationArgument(info[4], isolate);
     DeviceMotionData::RotationRate* rotationRate = readRotationRateArgument(info[5], isolate);
     bool intervalProvided = !isUndefinedOrNull(info[6]);
     double interval = 0;
     if (intervalProvided) {
         interval = toRestrictedDouble(info[6], exceptionState);
         if (exceptionState.throwIfNeeded())
             return;
     }
     DeviceMotionData* deviceMotionData = DeviceMotionData::create(acceleration, accelerationIncludingGravity, rotationRate, intervalProvided, interval);
     impl->initDeviceMotionEvent(type, bubbles, cancelable, deviceMotionData);
 }
 
 } // namespace blink