Refactor !foo.IsJust to foo.IsNothing()

BUG=v8:6921

Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Id29a5562b1551e78f60129216fdc2c209e585e43
Reviewed-on: https://chromium-review.googlesource.com/452381Reviewed-by: Alexei Filippov <alph@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48848}

src/api.cc

@@ -2798,7 +2798,7 @@ MaybeLocal<Value> v8::TryCatch::StackTrace(Local<Context> context) const {
   i::Handle<i::JSObject> obj(i::JSObject::cast(raw_obj), isolate_);
   i::Handle<i::String> name = isolate->factory()->stack_string();
   Maybe<bool> maybe = i::JSReceiver::HasProperty(obj, name);
-  has_pending_exception = !maybe.IsJust();
+  has_pending_exception = maybe.IsNothing();
   RETURN_ON_FAILED_EXECUTION(Value);
   if (!maybe.FromJust()) return v8::Local<Value>();
   Local<Value> result;

src/builtins/builtins-array.cc

@@ -773,7 +773,7 @@ bool IterateElementsSlow(Isolate* isolate, Handle<JSReceiver> receiver,
                          uint32_t length, ArrayConcatVisitor* visitor) {
   FOR_WITH_HANDLE_SCOPE(isolate, uint32_t, i = 0, i, i < length, ++i, {
     Maybe<bool> maybe = JSReceiver::HasElement(receiver, i);
-    if (!maybe.IsJust()) return false;
+    if (maybe.IsNothing()) return false;
     if (maybe.FromJust()) {
       Handle<Object> element_value;
       ASSIGN_RETURN_ON_EXCEPTION_VALUE(
@@ -836,7 +836,7 @@ bool IterateElements(Isolate* isolate, Handle<JSReceiver> receiver,
           if (!visitor->visit(j, element_value)) return false;
         } else {
           Maybe<bool> maybe = JSReceiver::HasElement(array, j);
-          if (!maybe.IsJust()) return false;
+          if (maybe.IsNothing()) return false;
           if (maybe.FromJust()) {
             // Call GetElement on array, not its prototype, or getters won't
             // have the correct receiver.
@@ -871,7 +871,7 @@ bool IterateElements(Isolate* isolate, Handle<JSReceiver> receiver,
           if (!visitor->visit(j, element_value)) return false;
         } else {
           Maybe<bool> maybe = JSReceiver::HasElement(array, j);
-          if (!maybe.IsJust()) return false;
+          if (maybe.IsNothing()) return false;
           if (maybe.FromJust()) {
             // Call GetElement on array, not its prototype, or getters won't
             // have the correct receiver.

src/builtins/builtins-function.cc

@@ -234,7 +234,7 @@ Object* DoFunctionBind(Isolate* isolate, BuiltinArguments args) {
     Handle<Object> length(Smi::kZero, isolate);
     Maybe<PropertyAttributes> attributes =
         JSReceiver::GetPropertyAttributes(&length_lookup);
-    if (!attributes.IsJust()) return isolate->heap()->exception();
+    if (attributes.IsNothing()) return isolate->heap()->exception();
     if (attributes.FromJust() != ABSENT) {
       Handle<Object> target_length;
       ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, target_length,

src/builtins/builtins-object.cc

@@ -52,7 +52,7 @@ BUILTIN(ObjectPrototypePropertyIsEnumerable) {
       isolate, object, JSReceiver::ToObject(isolate, args.receiver()));
   Maybe<PropertyAttributes> maybe =
       JSReceiver::GetOwnPropertyAttributes(object, name);
-  if (!maybe.IsJust()) return isolate->heap()->exception();
+  if (maybe.IsNothing()) return isolate->heap()->exception();
   if (maybe.FromJust() == ABSENT) return isolate->heap()->false_value();
   return isolate->heap()->ToBoolean((maybe.FromJust() & DONT_ENUM) == 0);
 }

src/contexts.cc

@@ -174,7 +174,7 @@ static Maybe<bool> UnscopableLookup(LookupIterator* it) {
   Isolate* isolate = it->isolate();
 
   Maybe<bool> found = JSReceiver::HasProperty(it);
-  if (!found.IsJust() || !found.FromJust()) return found;
+  if (found.IsNothing() || !found.FromJust()) return found;
 
   Handle<Object> unscopables;
   ASSIGN_RETURN_ON_EXCEPTION_VALUE(
@@ -295,7 +295,7 @@ Handle<Object> Context::Lookup(Handle<String> name, ContextLookupFlags flags,
         maybe = JSReceiver::GetPropertyAttributes(object, name);
       }
 
-      if (!maybe.IsJust()) return Handle<Object>();
+      if (maybe.IsNothing()) return Handle<Object>();
       DCHECK(!isolate->has_pending_exception());
       *attributes = maybe.FromJust();
 

src/inspector/v8-value-utils.cc

@@ -76,7 +76,8 @@ protocol::Response toProtocolValue(v8::Local<v8::Context> context,
       if (name->IsString()) {
         v8::Maybe<bool> hasRealNamedProperty = object->HasRealNamedProperty(
             context, v8::Local<v8::String>::Cast(name));
-        if (!hasRealNamedProperty.IsJust() || !hasRealNamedProperty.FromJust())
+        if (hasRealNamedProperty.IsNothing() ||
+            !hasRealNamedProperty.FromJust())
           continue;
       }
       v8::Local<v8::String> propertyName;

src/objects.cc

@@ -4776,7 +4776,7 @@ Maybe<bool> Object::SetPropertyInternal(LookupIterator* it,
         } else {
           Maybe<PropertyAttributes> maybe_attributes =
               JSObject::GetPropertyAttributesWithInterceptor(it);
-          if (!maybe_attributes.IsJust()) return Nothing<bool>();
+          if (maybe_attributes.IsNothing()) return Nothing<bool>();
           if ((maybe_attributes.FromJust() & READ_ONLY) != 0) {
             return WriteToReadOnlyProperty(it, value, should_throw);
           }
@@ -6106,7 +6106,7 @@ Maybe<PropertyAttributes> JSReceiver::GetPropertyAttributes(
       case LookupIterator::INTERCEPTOR: {
         Maybe<PropertyAttributes> result =
             JSObject::GetPropertyAttributesWithInterceptor(it);
-        if (!result.IsJust()) return result;
+        if (result.IsNothing()) return result;
         if (result.FromJust() != ABSENT) return result;
         break;
       }
@@ -6768,7 +6768,7 @@ MaybeHandle<Object> JSReceiver::DefineProperties(Isolate* isolate,
         isolate, props, next_key, &success, LookupIterator::OWN);
     DCHECK(success);
     Maybe<PropertyAttributes> maybe = JSReceiver::GetPropertyAttributes(&it);
-    if (!maybe.IsJust()) return MaybeHandle<Object>();
+    if (maybe.IsNothing()) return MaybeHandle<Object>();
     PropertyAttributes attrs = maybe.FromJust();
     // 7c. If propDesc is not undefined and propDesc.[[Enumerable]] is true:
     if (attrs == ABSENT) continue;
@@ -6798,7 +6798,7 @@ MaybeHandle<Object> JSReceiver::DefineProperties(Isolate* isolate,
         DefineOwnProperty(isolate, Handle<JSReceiver>::cast(object),
                           desc->name(), desc, THROW_ON_ERROR);
     // 8d. ReturnIfAbrupt(status).
-    if (!status.IsJust()) return MaybeHandle<Object>();
+    if (status.IsNothing()) return MaybeHandle<Object>();
     CHECK(status.FromJust());
   }
   // 9. Return o.

src/runtime/runtime-object.cc

@@ -294,7 +294,7 @@ RUNTIME_FUNCTION(Runtime_ObjectHasOwnProperty) {
 
     Maybe<bool> result =
         JSReceiver::HasOwnProperty(Handle<JSProxy>::cast(object), key);
-    if (!result.IsJust()) return isolate->heap()->exception();
+    if (result.IsNothing()) return isolate->heap()->exception();
     return isolate->heap()->ToBoolean(result.FromJust());
 
   } else if (object->IsString()) {
@@ -467,7 +467,7 @@ RUNTIME_FUNCTION(Runtime_AddNamedProperty) {
   DCHECK(!name->ToArrayIndex(&index));
   LookupIterator it(object, name, object, LookupIterator::OWN_SKIP_INTERCEPTOR);
   Maybe<PropertyAttributes> maybe = JSReceiver::GetPropertyAttributes(&it);
-  if (!maybe.IsJust()) return isolate->heap()->exception();
+  if (maybe.IsNothing()) return isolate->heap()->exception();
   DCHECK(!it.IsFound());
 #endif
 
@@ -493,7 +493,7 @@ RUNTIME_FUNCTION(Runtime_AddElement) {
   LookupIterator it(isolate, object, index, object,
                     LookupIterator::OWN_SKIP_INTERCEPTOR);
   Maybe<PropertyAttributes> maybe = JSReceiver::GetPropertyAttributes(&it);
-  if (!maybe.IsJust()) return isolate->heap()->exception();
+  if (maybe.IsNothing()) return isolate->heap()->exception();
   DCHECK(!it.IsFound());
 
   if (object->IsJSArray()) {
@@ -598,7 +598,7 @@ RUNTIME_FUNCTION(Runtime_HasProperty) {
 
   // Lookup the {name} on {receiver}.
   Maybe<bool> maybe = JSReceiver::HasProperty(receiver, name);
-  if (!maybe.IsJust()) return isolate->heap()->exception();
+  if (maybe.IsNothing()) return isolate->heap()->exception();
   return isolate->heap()->ToBoolean(maybe.FromJust());
 }
 

src/runtime/runtime-operators.cc

@@ -114,7 +114,7 @@ RUNTIME_FUNCTION(Runtime_Equal) {
   CONVERT_ARG_HANDLE_CHECKED(Object, x, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, y, 1);
   Maybe<bool> result = Object::Equals(x, y);
-  if (!result.IsJust()) return isolate->heap()->exception();
+  if (result.IsNothing()) return isolate->heap()->exception();
   return isolate->heap()->ToBoolean(result.FromJust());
 }
 
@@ -124,7 +124,7 @@ RUNTIME_FUNCTION(Runtime_NotEqual) {
   CONVERT_ARG_HANDLE_CHECKED(Object, x, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, y, 1);
   Maybe<bool> result = Object::Equals(x, y);
-  if (!result.IsJust()) return isolate->heap()->exception();
+  if (result.IsNothing()) return isolate->heap()->exception();
   return isolate->heap()->ToBoolean(!result.FromJust());
 }
 
@@ -150,7 +150,7 @@ RUNTIME_FUNCTION(Runtime_LessThan) {
   CONVERT_ARG_HANDLE_CHECKED(Object, x, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, y, 1);
   Maybe<bool> result = Object::LessThan(x, y);
-  if (!result.IsJust()) return isolate->heap()->exception();
+  if (result.IsNothing()) return isolate->heap()->exception();
   return isolate->heap()->ToBoolean(result.FromJust());
 }
 
@@ -160,7 +160,7 @@ RUNTIME_FUNCTION(Runtime_GreaterThan) {
   CONVERT_ARG_HANDLE_CHECKED(Object, x, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, y, 1);
   Maybe<bool> result = Object::GreaterThan(x, y);
-  if (!result.IsJust()) return isolate->heap()->exception();
+  if (result.IsNothing()) return isolate->heap()->exception();
   return isolate->heap()->ToBoolean(result.FromJust());
 }
 
@@ -170,7 +170,7 @@ RUNTIME_FUNCTION(Runtime_LessThanOrEqual) {
   CONVERT_ARG_HANDLE_CHECKED(Object, x, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, y, 1);
   Maybe<bool> result = Object::LessThanOrEqual(x, y);
-  if (!result.IsJust()) return isolate->heap()->exception();
+  if (result.IsNothing()) return isolate->heap()->exception();
   return isolate->heap()->ToBoolean(result.FromJust());
 }
 
@@ -180,7 +180,7 @@ RUNTIME_FUNCTION(Runtime_GreaterThanOrEqual) {
   CONVERT_ARG_HANDLE_CHECKED(Object, x, 0);
   CONVERT_ARG_HANDLE_CHECKED(Object, y, 1);
   Maybe<bool> result = Object::GreaterThanOrEqual(x, y);
-  if (!result.IsJust()) return isolate->heap()->exception();
+  if (result.IsNothing()) return isolate->heap()->exception();
   return isolate->heap()->ToBoolean(result.FromJust());
 }
 

src/runtime/runtime-scopes.cc

@@ -69,7 +69,7 @@ Object* DeclareGlobal(
   }
   LookupIterator it(global, name, global, lookup_config);
   Maybe<PropertyAttributes> maybe = JSReceiver::GetPropertyAttributes(&it);
-  if (!maybe.IsJust()) return isolate->heap()->exception();
+  if (maybe.IsNothing()) return isolate->heap()->exception();
 
   if (it.IsFound()) {
     PropertyAttributes old_attributes = maybe.FromJust();
@@ -684,7 +684,7 @@ static Object* FindNameClash(Handle<ScopeInfo> scope_info,
       LookupIterator it(global_object, name, global_object,
                         LookupIterator::OWN_SKIP_INTERCEPTOR);
       Maybe<PropertyAttributes> maybe = JSReceiver::GetPropertyAttributes(&it);
-      if (!maybe.IsJust()) return isolate->heap()->exception();
+      if (maybe.IsNothing()) return isolate->heap()->exception();
       if ((maybe.FromJust() & DONT_DELETE) != 0) {
         // ES#sec-globaldeclarationinstantiation 5.a:
         // If envRec.HasVarDeclaration(name) is true, throw a SyntaxError