Imported QtWebKit TP3 (git b57bc6801f1876c3220d5a4bfea33d620d477443)

Change-Id: I3b1d8a2808782c9f34d50240000e20cb38d3680f
Reviewed-by: Konstantin Tokarev <annulen@yandex.ru>

1 files changed, 249 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/bytecode/PutByIdVariant.cpp b/Source/JavaScriptCore/bytecode/PutByIdVariant.cpp
new file mode 100644
index 000000000..9904c625b
--- /dev/null
+++ b/Source/JavaScriptCore/bytecode/PutByIdVariant.cpp
@@ -0,0 +1,249 @@
+/*
+ * Copyright (C) 2014, 2015 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 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 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 "PutByIdVariant.h"
+
+#include "CallLinkStatus.h"
+#include "JSCInlines.h"
+#include <wtf/ListDump.h>
+
+namespace JSC {
+
+PutByIdVariant::PutByIdVariant(const PutByIdVariant& other)
+    : PutByIdVariant()
+{
+    *this = other;
+}
+
+PutByIdVariant& PutByIdVariant::operator=(const PutByIdVariant& other)
+{
+    m_kind = other.m_kind;
+    m_oldStructure = other.m_oldStructure;
+    m_newStructure = other.m_newStructure;
+    m_conditionSet = other.m_conditionSet;
+    m_offset = other.m_offset;
+    m_requiredType = other.m_requiredType;
+    if (other.m_callLinkStatus)
+        m_callLinkStatus = std::make_unique<CallLinkStatus>(*other.m_callLinkStatus);
+    else
+        m_callLinkStatus = nullptr;
+    return *this;
+}
+
+PutByIdVariant PutByIdVariant::replace(
+    const StructureSet& structure, PropertyOffset offset, const InferredType::Descriptor& requiredType)
+{
+    PutByIdVariant result;
+    result.m_kind = Replace;
+    result.m_oldStructure = structure;
+    result.m_offset = offset;
+    result.m_requiredType = requiredType;
+    return result;
+}
+
+PutByIdVariant PutByIdVariant::transition(
+    const StructureSet& oldStructure, Structure* newStructure,
+    const ObjectPropertyConditionSet& conditionSet, PropertyOffset offset,
+    const InferredType::Descriptor& requiredType)
+{
+    PutByIdVariant result;
+    result.m_kind = Transition;
+    result.m_oldStructure = oldStructure;
+    result.m_newStructure = newStructure;
+    result.m_conditionSet = conditionSet;
+    result.m_offset = offset;
+    result.m_requiredType = requiredType;
+    return result;
+}
+
+PutByIdVariant PutByIdVariant::setter(
+    const StructureSet& structure, PropertyOffset offset,
+    const ObjectPropertyConditionSet& conditionSet,
+    std::unique_ptr<CallLinkStatus> callLinkStatus)
+{
+    PutByIdVariant result;
+    result.m_kind = Setter;
+    result.m_oldStructure = structure;
+    result.m_conditionSet = conditionSet;
+    result.m_offset = offset;
+    result.m_callLinkStatus = WTFMove(callLinkStatus);
+    result.m_requiredType = InferredType::Top;
+    return result;
+}
+
+Structure* PutByIdVariant::oldStructureForTransition() const
+{
+    ASSERT(kind() == Transition);
+    ASSERT(m_oldStructure.size() <= 2);
+    for (unsigned i = m_oldStructure.size(); i--;) {
+        Structure* structure = m_oldStructure[i];
+        if (structure != m_newStructure)
+            return structure;
+    }
+    RELEASE_ASSERT_NOT_REACHED();
+
+    return nullptr;
+}
+
+bool PutByIdVariant::writesStructures() const
+{
+    switch (kind()) {
+    case Transition:
+    case Setter:
+        return true;
+    default:
+        return false;
+    }
+}
+
+bool PutByIdVariant::reallocatesStorage() const
+{
+    switch (kind()) {
+    case Transition:
+        return oldStructureForTransition()->outOfLineCapacity() != newStructure()->outOfLineCapacity();
+    case Setter:
+        return true;
+    default:
+        return false;
+    }
+}
+
+bool PutByIdVariant::makesCalls() const
+{
+    return kind() == Setter;
+}
+
+bool PutByIdVariant::attemptToMerge(const PutByIdVariant& other)
+{
+    if (m_offset != other.m_offset)
+        return false;
+
+    if (m_requiredType != other.m_requiredType)
+        return false;
+    
+    switch (m_kind) {
+    case Replace: {
+        switch (other.m_kind) {
+        case Replace: {
+            ASSERT(m_conditionSet.isEmpty());
+            ASSERT(other.m_conditionSet.isEmpty());
+            
+            m_oldStructure.merge(other.m_oldStructure);
+            return true;
+        }
+            
+        case Transition: {
+            PutByIdVariant newVariant = other;
+            if (newVariant.attemptToMergeTransitionWithReplace(*this)) {
+                *this = newVariant;
+                return true;
+            }
+            return false;
+        }
+            
+        default:
+            return false;
+        }
+    }
+        
+    case Transition:
+        switch (other.m_kind) {
+        case Replace:
+            return attemptToMergeTransitionWithReplace(other);
+            
+        default:
+            return false;
+        }
+        
+    default:
+        return false;
+    }
+}
+
+bool PutByIdVariant::attemptToMergeTransitionWithReplace(const PutByIdVariant& replace)
+{
+    ASSERT(m_kind == Transition);
+    ASSERT(replace.m_kind == Replace);
+    ASSERT(m_offset == replace.m_offset);
+    ASSERT(!replace.writesStructures());
+    ASSERT(!replace.reallocatesStorage());
+    ASSERT(replace.conditionSet().isEmpty());
+    
+    // This sort of merging only works when we have one path along which we add a new field which
+    // transitions to structure S while the other path was already on structure S. This doesn't
+    // work if we need to reallocate anything or if the replace path is polymorphic.
+    
+    if (reallocatesStorage())
+        return false;
+    
+    if (replace.m_oldStructure.onlyStructure() != m_newStructure)
+        return false;
+    
+    m_oldStructure.merge(m_newStructure);
+    return true;
+}
+
+void PutByIdVariant::dump(PrintStream& out) const
+{
+    dumpInContext(out, 0);
+}
+
+void PutByIdVariant::dumpInContext(PrintStream& out, DumpContext* context) const
+{
+    switch (kind()) {
+    case NotSet:
+        out.print("<empty>");
+        return;
+        
+    case Replace:
+        out.print(
+            "<Replace: ", inContext(structure(), context), ", offset = ", offset(), ", ",
+            inContext(requiredType(), context), ">");
+        return;
+        
+    case Transition:
+        out.print(
+            "<Transition: ", inContext(oldStructure(), context), " -> ",
+            pointerDumpInContext(newStructure(), context), ", [",
+            inContext(m_conditionSet, context), "], offset = ", offset(), ", ",
+            inContext(requiredType(), context), ">");
+        return;
+        
+    case Setter:
+        out.print(
+            "<Setter: ", inContext(structure(), context), ", [",
+            inContext(m_conditionSet, context), "]");
+        out.print(", offset = ", m_offset);
+        out.print(", call = ", *m_callLinkStatus);
+        out.print(">");
+        return;
+    }
+    
+    RELEASE_ASSERT_NOT_REACHED();
+}
+
+} // namespace JSC
+