Merge 'wip/next' into dev

Change-Id: Iff9ee5e23bb326c4371ec8ed81d56f2f05d680e9

1 files changed, 175 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/bytecode/ObjectPropertyConditionSet.h b/Source/JavaScriptCore/bytecode/ObjectPropertyConditionSet.h
new file mode 100644
index 000000000..957eaac25
--- /dev/null
+++ b/Source/JavaScriptCore/bytecode/ObjectPropertyConditionSet.h
@@ -0,0 +1,175 @@
+/*
+ * Copyright (C) 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. 
+ */
+
+#ifndef ObjectPropertyConditionSet_h
+#define ObjectPropertyConditionSet_h
+
+#include "ObjectPropertyCondition.h"
+#include <wtf/FastMalloc.h>
+#include <wtf/RefCounted.h>
+#include <wtf/Vector.h>
+
+namespace JSC {
+
+// An object property condition set is used to represent the set of additional conditions
+// that need to be met for some heap access to be valid. The set can have the following
+// interesting states:
+//
+// Empty: There are no special conditions that need to be met.
+// Invalid: The heap access is never valid.
+// Non-empty: The heap access is valid if all the ObjectPropertyConditions in the set are valid.
+
+class ObjectPropertyConditionSet {
+public:
+    ObjectPropertyConditionSet() { }
+    
+    static ObjectPropertyConditionSet invalid()
+    {
+        ObjectPropertyConditionSet result;
+        result.m_data = adoptRef(new Data());
+        return result;
+    }
+    
+    static ObjectPropertyConditionSet create(const Vector<ObjectPropertyCondition>& vector)
+    {
+        if (vector.isEmpty())
+            return ObjectPropertyConditionSet();
+        
+        ObjectPropertyConditionSet result;
+        result.m_data = adoptRef(new Data());
+        result.m_data->vector = vector;
+        return result;
+    }
+    
+    bool isValid() const
+    {
+        return !m_data || !m_data->vector.isEmpty();
+    }
+    
+    bool isEmpty() const
+    {
+        return !m_data;
+    }
+    
+    typedef const ObjectPropertyCondition* iterator;
+    
+    iterator begin() const
+    {
+        if (!m_data)
+            return nullptr;
+        return m_data->vector.begin();
+    }
+    iterator end() const
+    {
+        if (!m_data)
+            return nullptr;
+        return m_data->vector.end();
+    }
+    
+    ObjectPropertyCondition forObject(JSObject*) const;
+    ObjectPropertyCondition forConditionKind(PropertyCondition::Kind) const;
+
+    unsigned numberOfConditionsWithKind(PropertyCondition::Kind) const;
+
+    bool hasOneSlotBaseCondition() const;
+    
+    // If this is a condition set for a prototype hit, then this is guaranteed to return the
+    // condition on the prototype itself. This allows you to get the object, offset, and
+    // attributes for the prototype. This will RELEASE_ASSERT that there is exactly one Presence
+    // in the set, and it will return that presence.
+    ObjectPropertyCondition slotBaseCondition() const;
+    
+    // Attempt to create a new condition set by merging this one with the other one. This will
+    // fail if any of the conditions are incompatible with each other. When if fails, it returns
+    // invalid().
+    ObjectPropertyConditionSet mergedWith(const ObjectPropertyConditionSet& other) const;
+    
+    bool structuresEnsureValidity() const;
+    bool structuresEnsureValidityAssumingImpurePropertyWatchpoint() const;
+    
+    bool needImpurePropertyWatchpoint() const;
+    bool areStillLive() const;
+    
+    void dumpInContext(PrintStream&, DumpContext*) const;
+    void dump(PrintStream&) const;
+    
+    // Helpers for using this in a union.
+    void* releaseRawPointer()
+    {
+        return static_cast<void*>(m_data.leakRef());
+    }
+    static ObjectPropertyConditionSet adoptRawPointer(void* rawPointer)
+    {
+        ObjectPropertyConditionSet result;
+        result.m_data = adoptRef(static_cast<Data*>(rawPointer));
+        return result;
+    }
+    static ObjectPropertyConditionSet fromRawPointer(void* rawPointer)
+    {
+        ObjectPropertyConditionSet result;
+        result.m_data = static_cast<Data*>(rawPointer);
+        return result;
+    }
+
+    // FIXME: Everything below here should be private, but cannot be because of a bug in VS.
+    
+    // Internally, this represents Invalid using a pointer to a Data that has an empty vector.
+    
+    // FIXME: This could be made more compact by having it internally use a vector that just has
+    // the non-uid portion of ObjectPropertyCondition, and then requiring that the callers of all
+    // of the APIs supply the uid.
+    
+    class Data : public ThreadSafeRefCounted<Data> {
+        WTF_MAKE_NONCOPYABLE(Data);
+        WTF_MAKE_FAST_ALLOCATED;
+        
+    public:
+        Data() { }
+        
+        Vector<ObjectPropertyCondition> vector;
+    };
+    
+private:
+    RefPtr<Data> m_data;
+};
+
+ObjectPropertyConditionSet generateConditionsForPropertyMiss(
+    VM&, JSCell* owner, ExecState*, Structure* headStructure, UniquedStringImpl* uid);
+ObjectPropertyConditionSet generateConditionsForPropertySetterMiss(
+    VM&, JSCell* owner, ExecState*, Structure* headStructure, UniquedStringImpl* uid);
+ObjectPropertyConditionSet generateConditionsForPrototypePropertyHit(
+    VM&, JSCell* owner, ExecState*, Structure* headStructure, JSObject* prototype,
+    UniquedStringImpl* uid);
+ObjectPropertyConditionSet generateConditionsForPrototypePropertyHitCustom(
+    VM&, JSCell* owner, ExecState*, Structure* headStructure, JSObject* prototype,
+    UniquedStringImpl* uid);
+
+ObjectPropertyConditionSet generateConditionsForPropertySetterMissConcurrently(
+    VM&, JSGlobalObject*, Structure* headStructure, UniquedStringImpl* uid);
+
+} // namespace JSC
+
+#endif // ObjectPropertyConditionSet_h
+