1 files changed, 141 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/runtime/IntendedStructureChain.cpp b/Source/JavaScriptCore/runtime/IntendedStructureChain.cpp
new file mode 100644
index 000000000..b38dae9f8
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+++ b/Source/JavaScriptCore/runtime/IntendedStructureChain.cpp
@@ -0,0 +1,141 @@
+/*
+ * Copyright (C) 2013 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:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 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. 
+ */
+
+#include "config.h"
+#include "IntendedStructureChain.h"
+
+#include "CodeBlock.h"
+#include "Operations.h"
+#include "StructureChain.h"
+
+namespace JSC {
+
+IntendedStructureChain::IntendedStructureChain(JSGlobalObject* globalObject, Structure* head)
+    : m_globalObject(globalObject)
+    , m_head(head)
+{
+    JSValue prototype = head->prototypeForLookup(globalObject);
+    if (prototype.isNull())
+        return;
+    for (Structure* current = asObject(prototype)->structure(); current; current = current->storedPrototypeStructure())
+        m_vector.append(current);
+}
+
+IntendedStructureChain::IntendedStructureChain(CodeBlock* codeBlock, Structure* head, Structure* prototypeStructure)
+    : m_globalObject(codeBlock->globalObject())
+    , m_head(head)
+{
+    m_vector.append(prototypeStructure);
+}
+
+IntendedStructureChain::IntendedStructureChain(CodeBlock* codeBlock, Structure* head, StructureChain* chain)
+    : m_globalObject(codeBlock->globalObject())
+    , m_head(head)
+{
+    for (unsigned i = 0; chain->head()[i]; ++i)
+        m_vector.append(chain->head()[i].get());
+}
+
+IntendedStructureChain::IntendedStructureChain(CodeBlock* codeBlock, Structure* head, StructureChain* chain, unsigned count)
+    : m_globalObject(codeBlock->globalObject())
+    , m_head(head)
+{
+    for (unsigned i = 0; i < count; ++i)
+        m_vector.append(chain->head()[i].get());
+}
+
+IntendedStructureChain::~IntendedStructureChain()
+{
+}
+
+bool IntendedStructureChain::isStillValid() const
+{
+    JSValue currentPrototype = m_head->prototypeForLookup(m_globalObject);
+    for (unsigned i = 0; i < m_vector.size(); ++i) {
+        if (asObject(currentPrototype)->structure() != m_vector[i])
+            return false;
+        currentPrototype = m_vector[i]->storedPrototype();
+    }
+    return true;
+}
+
+bool IntendedStructureChain::matches(StructureChain* chain) const
+{
+    for (unsigned i = 0; i < m_vector.size(); ++i) {
+        if (m_vector[i] != chain->head()[i].get())
+            return false;
+    }
+    if (chain->head()[m_vector.size()])
+        return false;
+    return true;
+}
+
+StructureChain* IntendedStructureChain::chain(VM& vm) const
+{
+    ASSERT(isStillValid());
+    StructureChain* result = StructureChain::create(vm, m_head);
+    ASSERT(matches(result));
+    return result;
+}
+
+bool IntendedStructureChain::mayInterceptStoreTo(VM& vm, StringImpl* uid)
+{
+    for (unsigned i = 0; i < m_vector.size(); ++i) {
+        unsigned attributes;
+        JSCell* specificValue;
+        PropertyOffset offset = m_vector[i]->getConcurrently(vm, uid, attributes, specificValue);
+        if (!isValidOffset(offset))
+            continue;
+        if (attributes & (ReadOnly | Accessor))
+            return true;
+        return false;
+    }
+    return false;
+}
+
+bool IntendedStructureChain::isNormalized()
+{
+    if (m_head->typeInfo().type() == ProxyType)
+        return false;
+    for (unsigned i = 0; i < m_vector.size(); ++i) {
+        Structure* structure = m_vector[i];
+        if (structure->typeInfo().type() == ProxyType)
+            return false;
+        if (structure->isDictionary())
+            return false;
+    }
+    return true;
+}
+
+JSObject* IntendedStructureChain::terminalPrototype() const
+{
+    ASSERT(!m_vector.isEmpty());
+    if (m_vector.size() == 1)
+        return asObject(m_head->prototypeForLookup(m_globalObject));
+    return asObject(m_vector[m_vector.size() - 2]->storedPrototype());
+}
+
+} // namespace JSC
+