Use ExceptionState to throw exceptions when converting arrays

Source/bindings/core/v8/V8Binding.h

 /*
 * Copyright (C) 2009 Google Inc. All rights reserved.
 * Copyright (C) 2012 Ericsson AB. 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.
@@ skipping 16 matching lines @@
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
 #ifndef V8Binding_h
 #define V8Binding_h
 
 #include "bindings/core/v8/DOMWrapperWorld.h"
 #include "bindings/core/v8/ExceptionMessages.h"
+#include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ScriptValue.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "bindings/core/v8/V8BindingMacros.h"
 #include "bindings/core/v8/V8PerIsolateData.h"
 #include "bindings/core/v8/V8StringResource.h"
 #include "bindings/core/v8/V8ThrowException.h"
 #include "bindings/core/v8/V8ValueCache.h"
 #include "platform/heap/Heap.h"
 #include "wtf/GetPtr.h"
 #include "wtf/MathExtras.h"
@@ skipping 518 matching lines @@
 }
 
 // FIXME: Remove the special casing for NodeFilter and XPathNSResolver.
 PassRefPtrWillBeRawPtr<NodeFilter> toNodeFilter(v8::Handle<v8::Value>, v8::Handle<v8::Object>, ScriptState*);
 PassRefPtrWillBeRawPtr<XPathNSResolver> toXPathNSResolver(v8::Handle<v8::Value>, v8::Isolate*);
 
 template<class T> struct NativeValueTraits;
 
 template<>
 struct NativeValueTraits<String> {
-    static inline String nativeValue(const v8::Handle<v8::Value>& value, v8::Isolate* isolate)
+    static inline String nativeValue(const v8::Handle<v8::Value>& value, v8::Isolate* isolate, ExceptionState& exceptionState)
     {
-        TOSTRING_DEFAULT(V8StringResource<>, stringValue, value, String());
+        V8StringResource<> stringValue(value);
+        if (!stringValue.prepare(exceptionState))
+            return String();
         return stringValue;
     }
 };
 
 template<>
 struct NativeValueTraits<unsigned> {
-    static inline unsigned nativeValue(const v8::Handle<v8::Value>& value, v8::Isolate* isolate)
+    static inline unsigned nativeValue(const v8::Handle<v8::Value>& value, v8::Isolate* isolate, ExceptionState& exceptionState)
     {
-        return toUInt32(value);
+        return toUInt32(value, exceptionState);
     }
 };
 
 template<>
 struct NativeValueTraits<float> {
-    static inline float nativeValue(const v8::Handle<v8::Value>& value, v8::Isolate* isolate)
+    static inline float nativeValue(const v8::Handle<v8::Value>& value, v8::Isolate* isolate, ExceptionState& exceptionState)
     {
-        return static_cast<float>(value->NumberValue());
+        return toFloat(value, exceptionState);
     }
 };
 
 template<>
 struct NativeValueTraits<double> {
-    static inline double nativeValue(const v8::Handle<v8::Value>& value, v8::Isolate* isolate)
+    static inline double nativeValue(const v8::Handle<v8::Value>& value, v8::Isolate* isolate, ExceptionState& exceptionState)
     {
-        return static_cast<double>(value->NumberValue());
+        return toDouble(value, exceptionState);
     }
 };
 
 template<>
 struct NativeValueTraits<v8::Handle<v8::Value> > {
-    static inline v8::Handle<v8::Value> nativeValue(const v8::Handle<v8::Value>& value, v8::Isolate* isolate)
+    static inline v8::Handle<v8::Value> nativeValue(const v8::Handle<v8::Value>& value, v8::Isolate* isolate, ExceptionState&)
     {
         return value;
     }
 };
 
 template<>
 struct NativeValueTraits<ScriptValue> {
-    static inline ScriptValue nativeValue(const v8::Handle<v8::Value>& value, v8::Isolate* isolate)
+    static inline ScriptValue nativeValue(const v8::Handle<v8::Value>& value, v8::Isolate* isolate, ExceptionState&)
     {
         return ScriptValue(ScriptState::current(isolate), value);
     }
 };
 
-v8::Handle<v8::Value> toV8Sequence(v8::Handle<v8::Value>, uint32_t& length, v8::Isolate*);
+bool toV8Sequence(v8::Handle<v8::Value>, uint32_t& length, v8::Isolate*, ExceptionState&);

[Jens Widell, 2014/09/12 11:34:36]

Extended patch to cover toV8Sequence() too.

Its error handling was broken before: it returned a (non-empty) handle
containing undefined to signal to callers that they should throw a TypeError, or
a handle containing the exception, if one was thrown when accessing the object's
|length| property. And if all went well, toV8Sequence() returned a new handle
containing the input value (unchanged.)

What all callers did however was: If return value is an empty handle, throw a
TypeError, otherwise go ahead and use the "fetched" length, which would always
be zero if toV8Sequence() actually failed. No TypeError exceptions were thrown,
and no exceptions were propagated.

It now takes an ExceptionState& argument, and propagates exceptions via it. It
also signals success or failure via its boolean return value instead of
returning a handle. If it returns false (failed), callers need to check the
ExceptionState object: if it has an exception, then that's it, otherwise callers
should throw a TypeError.

 
 // Converts a JavaScript value to an array as per the Web IDL specification:
 // http://www.w3.org/TR/2012/CR-WebIDL-20120419/#es-array
 template <class T, class V8T>
-Vector<RefPtr<T> > toRefPtrNativeArrayUnchecked(v8::Local<v8::Value> v8Value, uint32_t length, v8::Isolate* isolate, bool* success = 0)
+Vector<RefPtr<T> > toRefPtrNativeArrayUnchecked(v8::Local<v8::Value> v8Value, uint32_t length, v8::Isolate* isolate, ExceptionState& exceptionState)
 {
     Vector<RefPtr<T> > result;
     result.reserveInitialCapacity(length);
     v8::Local<v8::Object> object = v8::Local<v8::Object>::Cast(v8Value);
+    v8::TryCatch block;
     for (uint32_t i = 0; i < length; ++i) {
         v8::Handle<v8::Value> element = object->Get(i);
+        if (block.HasCaught()) {
+            exceptionState.rethrowV8Exception(block.Exception());
+            return Vector<RefPtr<T> >();
+        }
         if (V8T::hasInstance(element, isolate)) {
             v8::Handle<v8::Object> elementObject = v8::Handle<v8::Object>::Cast(element);
             result.uncheckedAppend(V8T::toImpl(elementObject));
         } else {
-            if (success)
-                *success = false;
-            V8ThrowException::throwTypeError("Invalid Array element type", isolate);
+            exceptionState.throwTypeError("Invalid Array element type");
             return Vector<RefPtr<T> >();
         }
     }
     return result;
 }
 
 template <class T, class V8T>
-Vector<RefPtr<T> > toRefPtrNativeArray(v8::Handle<v8::Value> value, int argumentIndex, v8::Isolate* isolate, bool* success = 0)
+Vector<RefPtr<T> > toRefPtrNativeArray(v8::Handle<v8::Value> value, int argumentIndex, v8::Isolate* isolate, ExceptionState& exceptionState)
 {
-    if (success)
-        *success = true;
-
     v8::Local<v8::Value> v8Value(v8::Local<v8::Value>::New(isolate, value));
     uint32_t length = 0;
     if (value->IsArray()) {
         length = v8::Local<v8::Array>::Cast(v8Value)->Length();
-    } else if (toV8Sequence(value, length, isolate).IsEmpty()) {
-        V8ThrowException::throwTypeError(ExceptionMessages::notAnArrayTypeArgumentOrValue(argumentIndex), isolate);
+    } else if (!toV8Sequence(value, length, isolate, exceptionState)) {
+        if (!exceptionState.hadException())
+            exceptionState.throwTypeError(ExceptionMessages::notAnArrayTypeArgumentOrValue(argumentIndex));
         return Vector<RefPtr<T> >();
     }
-    return toRefPtrNativeArrayUnchecked<T, V8T>(v8Value, length, isolate, success);
+    return toRefPtrNativeArrayUnchecked<T, V8T>(v8Value, length, isolate, exceptionState);
 }
 
 template <class T, class V8T>
-Vector<RefPtr<T> > toRefPtrNativeArray(v8::Handle<v8::Value> value, const String& propertyName, v8::Isolate* isolate, bool* success = 0)
+Vector<RefPtr<T> > toRefPtrNativeArray(v8::Handle<v8::Value> value, const String& propertyName, v8::Isolate* isolate, ExceptionState& exceptionState)
 {
-    if (success)
-        *success = true;
-
     v8::Local<v8::Value> v8Value(v8::Local<v8::Value>::New(isolate, value));
     uint32_t length = 0;
     if (value->IsArray()) {
         length = v8::Local<v8::Array>::Cast(v8Value)->Length();
-    } else if (toV8Sequence(value, length, isolate).IsEmpty()) {
-        V8ThrowException::throwTypeError(ExceptionMessages::notASequenceTypeProperty(propertyName), isolate);
+    } else if (!toV8Sequence(value, length, isolate, exceptionState)) {
+        if (!exceptionState.hadException())
+            exceptionState.throwTypeError(ExceptionMessages::notASequenceTypeProperty(propertyName));
         return Vector<RefPtr<T> >();
     }
-    return toRefPtrNativeArrayUnchecked<T, V8T>(v8Value, length, isolate, success);
+    return toRefPtrNativeArrayUnchecked<T, V8T>(v8Value, length, isolate, exceptionState);
 }
 
 template <class T, class V8T>
-WillBeHeapVector<RefPtrWillBeMember<T> > toRefPtrWillBeMemberNativeArray(v8::Handle<v8::Value> value, int argumentIndex, v8::Isolate* isolate, bool* success = 0)
+WillBeHeapVector<RefPtrWillBeMember<T> > toRefPtrWillBeMemberNativeArray(v8::Handle<v8::Value> value, int argumentIndex, v8::Isolate* isolate, ExceptionState& exceptionState)
 {
-    if (success)
-        *success = true;
-
     v8::Local<v8::Value> v8Value(v8::Local<v8::Value>::New(isolate, value));
     uint32_t length = 0;
     if (value->IsArray()) {
         length = v8::Local<v8::Array>::Cast(v8Value)->Length();
-    } else if (toV8Sequence(value, length, isolate).IsEmpty()) {
-        V8ThrowException::throwTypeError(ExceptionMessages::notAnArrayTypeArgumentOrValue(argumentIndex), isolate);
+    } else if (!toV8Sequence(value, length, isolate, exceptionState)) {
+        if (!exceptionState.hadException())
+            exceptionState.throwTypeError(ExceptionMessages::notAnArrayTypeArgumentOrValue(argumentIndex));
         return WillBeHeapVector<RefPtrWillBeMember<T> >();
     }
 
     WillBeHeapVector<RefPtrWillBeMember<T> > result;
     result.reserveInitialCapacity(length);
     v8::Local<v8::Object> object = v8::Local<v8::Object>::Cast(v8Value);
+    v8::TryCatch block;
     for (uint32_t i = 0; i < length; ++i) {
         v8::Handle<v8::Value> element = object->Get(i);
+        if (block.HasCaught()) {
+            exceptionState.rethrowV8Exception(block.Exception());
+            return WillBeHeapVector<RefPtrWillBeMember<T> >();
+        }
         if (V8T::hasInstance(element, isolate)) {
             v8::Handle<v8::Object> elementObject = v8::Handle<v8::Object>::Cast(element);
             result.uncheckedAppend(V8T::toImpl(elementObject));
         } else {
-            if (success)
-                *success = false;
-            V8ThrowException::throwTypeError("Invalid Array element type", isolate);
+            exceptionState.throwTypeError("Invalid Array element type");
             return WillBeHeapVector<RefPtrWillBeMember<T> >();
         }
     }
     return result;
 }
 
 template <class T, class V8T>
-WillBeHeapVector<RefPtrWillBeMember<T> > toRefPtrWillBeMemberNativeArray(v8::Handle<v8::Value> value, const String& propertyName, v8::Isolate* isolate, bool* success = 0)
+WillBeHeapVector<RefPtrWillBeMember<T> > toRefPtrWillBeMemberNativeArray(v8::Handle<v8::Value> value, const String& propertyName, v8::Isolate* isolate, ExceptionState& exceptionState)
 {
-    if (success)
-        *success = true;
-
     v8::Local<v8::Value> v8Value(v8::Local<v8::Value>::New(isolate, value));
     uint32_t length = 0;
     if (value->IsArray()) {
         length = v8::Local<v8::Array>::Cast(v8Value)->Length();
-    } else if (toV8Sequence(value, length, isolate).IsEmpty()) {
-        V8ThrowException::throwTypeError(ExceptionMessages::notASequenceTypeProperty(propertyName), isolate);
+    } else if (!toV8Sequence(value, length, isolate, exceptionState)) {
+        if (!exceptionState.hadException())
+            exceptionState.throwTypeError(ExceptionMessages::notASequenceTypeProperty(propertyName));
         return WillBeHeapVector<RefPtrWillBeMember<T> >();
     }
 
     WillBeHeapVector<RefPtrWillBeMember<T> > result;
     result.reserveInitialCapacity(length);
     v8::Local<v8::Object> object = v8::Local<v8::Object>::Cast(v8Value);
+    v8::TryCatch block;
     for (uint32_t i = 0; i < length; ++i) {
         v8::Handle<v8::Value> element = object->Get(i);
+        if (block.HasCaught()) {
+            exceptionState.rethrowV8Exception(block.Exception());
+            return Vector<RefPtr<T> >();
+        }
         if (V8T::hasInstance(element, isolate)) {
             v8::Handle<v8::Object> elementObject = v8::Handle<v8::Object>::Cast(element);
             result.uncheckedAppend(V8T::toImpl(elementObject));
         } else {
-            if (success)
-                *success = false;
-            V8ThrowException::throwTypeError("Invalid Array element type", isolate);
+            exceptionState.throwTypeError("Invalid Array element type");
             return WillBeHeapVector<RefPtrWillBeMember<T> >();
         }
     }
     return result;
 }
 
 template <class T, class V8T>
-HeapVector<Member<T> > toMemberNativeArray(v8::Handle<v8::Value> value, int argumentIndex, v8::Isolate* isolate, bool* success = 0)
+HeapVector<Member<T> > toMemberNativeArray(v8::Handle<v8::Value> value, int argumentIndex, v8::Isolate* isolate, ExceptionState& exceptionState)
 {
-    if (success)
-        *success = true;
-
     v8::Local<v8::Value> v8Value(v8::Local<v8::Value>::New(isolate, value));
     uint32_t length = 0;
     if (value->IsArray()) {
         length = v8::Local<v8::Array>::Cast(v8Value)->Length();
-    } else if (toV8Sequence(value, length, isolate).IsEmpty()) {
-        V8ThrowException::throwTypeError(ExceptionMessages::notAnArrayTypeArgumentOrValue(argumentIndex), isolate);
+    } else if (!toV8Sequence(value, length, isolate, exceptionState)) {
+        if (!exceptionState.hadException())
+            exceptionState.throwTypeError(ExceptionMessages::notAnArrayTypeArgumentOrValue(argumentIndex));
         return HeapVector<Member<T> >();
     }
 
     HeapVector<Member<T> > result;
     result.reserveInitialCapacity(length);
     v8::Local<v8::Object> object = v8::Local<v8::Object>::Cast(v8Value);
+    v8::TryCatch block;
     for (uint32_t i = 0; i < length; ++i) {
         v8::Handle<v8::Value> element = object->Get(i);
+        if (UNLIKELY(block.HasCaught())) {
+            exceptionState.rethrowV8Exception(block.Exception());
+            return HeapVector<Member<T> >();
+        }
         if (V8T::hasInstance(element, isolate)) {
             v8::Handle<v8::Object> elementObject = v8::Handle<v8::Object>::Cast(element);
             result.uncheckedAppend(V8T::toImpl(elementObject));
         } else {
-            if (success)
-                *success = false;
-            V8ThrowException::throwTypeError("Invalid Array element type", isolate);
+            exceptionState.throwTypeError("Invalid Array element type");
             return HeapVector<Member<T> >();
         }
     }
     return result;
 }
 
 // Converts a JavaScript value to an array as per the Web IDL specification:
 // http://www.w3.org/TR/2012/CR-WebIDL-20120419/#es-array
 template <class T>
-Vector<T> toImplArray(v8::Handle<v8::Value> value, int argumentIndex, v8::Isolate* isolate)
+Vector<T> toImplArray(v8::Handle<v8::Value> value, int argumentIndex, v8::Isolate* isolate, ExceptionState& exceptionState)
 {
     v8::Local<v8::Value> v8Value(v8::Local<v8::Value>::New(isolate, value));
     uint32_t length = 0;
     if (value->IsArray()) {
         length = v8::Local<v8::Array>::Cast(v8Value)->Length();
-    } else if (toV8Sequence(value, length, isolate).IsEmpty()) {
-        V8ThrowException::throwTypeError(ExceptionMessages::notAnArrayTypeArgumentOrValue(argumentIndex), isolate);
+    } else if (!toV8Sequence(value, length, isolate, exceptionState)) {
+        if (!exceptionState.hadException())
+            exceptionState.throwTypeError(ExceptionMessages::notAnArrayTypeArgumentOrValue(argumentIndex));
         return Vector<T>();
     }
 
     Vector<T> result;
     result.reserveInitialCapacity(length);
     typedef NativeValueTraits<T> TraitsType;
     v8::Local<v8::Object> object = v8::Local<v8::Object>::Cast(v8Value);
-    for (uint32_t i = 0; i < length; ++i)
-        result.uncheckedAppend(TraitsType::nativeValue(object->Get(i), isolate));
+    v8::TryCatch block;
+    for (uint32_t i = 0; i < length; ++i) {
+        v8::Handle<v8::Value> element = object->Get(i);
+        if (UNLIKELY(block.HasCaught())) {
+            exceptionState.rethrowV8Exception(block.Exception());
+            return Vector<T>();
+        }
+        result.uncheckedAppend(TraitsType::nativeValue(element, isolate, exceptionState));
+        if (exceptionState.hadException())
+            return Vector<T>();
+    }
     return result;
 }
 
 template <class T>
-Vector<T> toImplArguments(const v8::FunctionCallbackInfo<v8::Value>& info, int startIndex)
+Vector<T> toImplArguments(const v8::FunctionCallbackInfo<v8::Value>& info, int startIndex, ExceptionState& exceptionState)
 {
     ASSERT(startIndex <= info.Length());
     Vector<T> result;
     typedef NativeValueTraits<T> TraitsType;
     int length = info.Length();
     result.reserveInitialCapacity(length);
-    for (int i = startIndex; i < length; ++i)
-        result.uncheckedAppend(TraitsType::nativeValue(info[i], info.GetIsolate()));
+    for (int i = startIndex; i < length; ++i) {
+        result.uncheckedAppend(TraitsType::nativeValue(info[i], info.GetIsolate(), exceptionState));
+        if (exceptionState.hadException())
+            return Vector<T>();
+    }
     return result;
 }
 
 // Validates that the passed object is a sequence type per WebIDL spec
 // http://www.w3.org/TR/2012/CR-WebIDL-20120419/#es-sequence
-inline v8::Handle<v8::Value> toV8Sequence(v8::Handle<v8::Value> value, uint32_t& length, v8::Isolate* isolate)
+bool toV8Sequence(v8::Handle<v8::Value> value, uint32_t& length, v8::Isolate* isolate, ExceptionState& exceptionState)
 {
     // Attempt converting to a sequence if the value is not already an array but is
     // any kind of object except for a native Date object or a native RegExp object.
     ASSERT(!value->IsArray());
     // FIXME: Do we really need to special case Date and RegExp object?
     // https://www.w3.org/Bugs/Public/show_bug.cgi?id=22806
     if (!value->IsObject() || value->IsDate() || value->IsRegExp()) {
         // The caller is responsible for reporting a TypeError.
-        return v8Undefined();
+        return false;
     }
 
     v8::Local<v8::Value> v8Value(v8::Local<v8::Value>::New(isolate, value));
     v8::Local<v8::Object> object = v8::Local<v8::Object>::Cast(v8Value);
     v8::Local<v8::String> lengthSymbol = v8AtomicString(isolate, "length");
 
     // FIXME: The specification states that the length property should be used as fallback, if value
     // is not a platform object that supports indexed properties. If it supports indexed properties,
     // length should actually be one greater than value’s maximum indexed property index.
-    TONATIVE_EXCEPTION(v8::Local<v8::Value>, lengthValue, object->Get(lengthSymbol));
+    v8::TryCatch block;
+    v8::Local<v8::Value> lengthValue = object->Get(lengthSymbol);
+    if (block.HasCaught()) {
+        exceptionState.rethrowV8Exception(block.Exception());
+        return false;
+    }
 
     if (lengthValue->IsUndefined() || lengthValue->IsNull()) {
         // The caller is responsible for reporting a TypeError.
-        return v8Undefined();
+        return false;
     }
 
-    TONATIVE_EXCEPTION(uint32_t, sequenceLength, lengthValue->Int32Value());
+    uint32_t sequenceLength = lengthValue->Int32Value();
+    if (block.HasCaught()) {
+        exceptionState.rethrowV8Exception(block.Exception());
+        return false;
+    }
+
     length = sequenceLength;
-    return v8Value;
+    return true;
 }
 
 v8::Isolate* toIsolate(ExecutionContext*);
 v8::Isolate* toIsolate(LocalFrame*);
 
 LocalDOMWindow* toDOMWindow(v8::Handle<v8::Value>, v8::Isolate*);
 LocalDOMWindow* toDOMWindow(v8::Handle<v8::Context>);
 LocalDOMWindow* enteredDOMWindow(v8::Isolate*);
 LocalDOMWindow* currentDOMWindow(v8::Isolate*);
 LocalDOMWindow* callingDOMWindow(v8::Isolate*);
@@ skipping 117 matching lines @@
 v8::Local<v8::Value> v8IteratorResult(v8::Isolate*, v8::Handle<v8::Value>);
 template <typename T>
 v8::Local<v8::Value> v8IteratorResult(ScriptState* scriptState, const T& value)
 {
     return v8IteratorResult(scriptState->isolate(), V8ValueTraits<T>::toV8Value(value, scriptState->context()->Global(), scriptState->isolate()));
 }
 
 } // namespace blink
 
 #endif // V8Binding_h