[inspector] Initial import of v8_inspector.

src/inspector/V8ValueCopier.cpp

Index: src/inspector/V8ValueCopier.cpp
diff --git a/src/inspector/V8ValueCopier.cpp b/src/inspector/V8ValueCopier.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..a61fafe9128e917969ae2bf1ac26893db418e289
--- /dev/null
+++ b/src/inspector/V8ValueCopier.cpp
@@ -0,0 +1,110 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/inspector/V8ValueCopier.h"
+
+namespace v8_inspector {
+
+namespace {
+
+static int kMaxDepth = 20;
+static int kMaxCalls = 1000;
+
+class V8ValueCopier {
+ public:
+  v8::MaybeLocal<v8::Value> copy(v8::Local<v8::Value> value, int depth) {
+    if (++m_calls > kMaxCalls || depth > kMaxDepth)
+      return v8::MaybeLocal<v8::Value>();
+
+    if (value.IsEmpty()) return v8::MaybeLocal<v8::Value>();
+    if (value->IsNull() || value->IsUndefined() || value->IsBoolean() ||
+        value->IsString() || value->IsNumber())
+      return value;
+    if (!value->IsObject()) return v8::MaybeLocal<v8::Value>();
+    v8::Local<v8::Object> object = value.As<v8::Object>();
+    if (object->CreationContext() != m_from) return value;
+
+    if (object->IsArray()) {
+      v8::Local<v8::Array> array = object.As<v8::Array>();
+      v8::Local<v8::Array> result = v8::Array::New(m_isolate, array->Length());
+      if (!result->SetPrototype(m_to, v8::Null(m_isolate)).FromMaybe(false))
+        return v8::MaybeLocal<v8::Value>();
+      for (size_t i = 0; i < array->Length(); ++i) {
+        v8::Local<v8::Value> item;
+        if (!array->Get(m_from, i).ToLocal(&item))
+          return v8::MaybeLocal<v8::Value>();
+        v8::Local<v8::Value> copied;
+        if (!copy(item, depth + 1).ToLocal(&copied))
+          return v8::MaybeLocal<v8::Value>();
+        if (!createDataProperty(m_to, result, i, copied).FromMaybe(false))
+          return v8::MaybeLocal<v8::Value>();
+      }
+      return result;
+    }
+
+    v8::Local<v8::Object> result = v8::Object::New(m_isolate);
+    if (!result->SetPrototype(m_to, v8::Null(m_isolate)).FromMaybe(false))
+      return v8::MaybeLocal<v8::Value>();
+    v8::Local<v8::Array> properties;
+    if (!object->GetOwnPropertyNames(m_from).ToLocal(&properties))
+      return v8::MaybeLocal<v8::Value>();
+    for (size_t i = 0; i < properties->Length(); ++i) {
+      v8::Local<v8::Value> name;
+      if (!properties->Get(m_from, i).ToLocal(&name) || !name->IsString())
+        return v8::MaybeLocal<v8::Value>();
+      v8::Local<v8::Value> property;
+      if (!object->Get(m_from, name).ToLocal(&property))
+        return v8::MaybeLocal<v8::Value>();
+      v8::Local<v8::Value> copied;
+      if (!copy(property, depth + 1).ToLocal(&copied))
+        return v8::MaybeLocal<v8::Value>();
+      if (!createDataProperty(m_to, result, v8::Local<v8::String>::Cast(name),
+                              copied)
+               .FromMaybe(false))
+        return v8::MaybeLocal<v8::Value>();
+    }
+    return result;
+  }
+
+  v8::Isolate* m_isolate;
+  v8::Local<v8::Context> m_from;
+  v8::Local<v8::Context> m_to;
+  int m_calls;
+};
+
+}  // namespace
+
+v8::MaybeLocal<v8::Value> copyValueFromDebuggerContext(
+    v8::Isolate* isolate, v8::Local<v8::Context> debuggerContext,
+    v8::Local<v8::Context> toContext, v8::Local<v8::Value> value) {
+  V8ValueCopier copier;
+  copier.m_isolate = isolate;
+  copier.m_from = debuggerContext;
+  copier.m_to = toContext;
+  copier.m_calls = 0;
+  return copier.copy(value, 0);
+}
+
+v8::Maybe<bool> createDataProperty(v8::Local<v8::Context> context,
+                                   v8::Local<v8::Object> object,
+                                   v8::Local<v8::Name> key,
+                                   v8::Local<v8::Value> value) {
+  v8::TryCatch tryCatch(context->GetIsolate());
+  v8::Isolate::DisallowJavascriptExecutionScope throwJs(
+      context->GetIsolate(),
+      v8::Isolate::DisallowJavascriptExecutionScope::THROW_ON_FAILURE);
+  return object->CreateDataProperty(context, key, value);
+}
+
+v8::Maybe<bool> createDataProperty(v8::Local<v8::Context> context,
+                                   v8::Local<v8::Array> array, int index,
+                                   v8::Local<v8::Value> value) {
+  v8::TryCatch tryCatch(context->GetIsolate());
+  v8::Isolate::DisallowJavascriptExecutionScope throwJs(
+      context->GetIsolate(),
+      v8::Isolate::DisallowJavascriptExecutionScope::THROW_ON_FAILURE);
+  return array->CreateDataProperty(context, index, value);
+}
+
+}  // namespace v8_inspector