JavaScriptCore-1097.3.tar.gz

[apple/javascriptcore.git] / bytecode / GetByIdStatus.h

diff --git a/bytecode/GetByIdStatus.h b/bytecode/GetByIdStatus.h
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+/*
+ * Copyright (C) 2012 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 GetByIdStatus_h
+#define GetByIdStatus_h
+
+#include "StructureSet.h"
+#include <wtf/NotFound.h>
+
+namespace JSC {
+
+class CodeBlock;
+class Identifier;
+
+class GetByIdStatus {
+public:
+    enum State {
+        NoInformation,  // It's uncached so we have no information.
+        SimpleDirect,   // It's cached for a direct access to a known object property.
+        TakesSlowPath,  // It's known to often take slow path.
+        MakesCalls      // It's known to take paths that make calls.
+    };
+
+    GetByIdStatus()
+        : m_state(NoInformation)
+        , m_offset(notFound)
+    {
+    }
+    
+    GetByIdStatus(State state, const StructureSet& structureSet, size_t offset, bool wasSeenInJIT)
+        : m_state(state)
+        , m_structureSet(structureSet)
+        , m_offset(offset)
+        , m_wasSeenInJIT(wasSeenInJIT)
+    {
+        ASSERT((state == SimpleDirect) == (offset != notFound));
+    }
+    
+    static GetByIdStatus computeFor(CodeBlock*, unsigned bytecodeIndex, Identifier&);
+    
+    State state() const { return m_state; }
+    
+    bool isSet() const { return m_state != NoInformation; }
+    bool operator!() const { return !isSet(); }
+    bool isSimpleDirect() const { return m_state == SimpleDirect; }
+    bool takesSlowPath() const { return m_state == TakesSlowPath || m_state == MakesCalls; }
+    bool makesCalls() const { return m_state == MakesCalls; }
+    
+    const StructureSet& structureSet() const { return m_structureSet; }
+    size_t offset() const { return m_offset; }
+    
+    bool wasSeenInJIT() const { return m_wasSeenInJIT; }
+    
+private:
+    static GetByIdStatus computeFromLLInt(CodeBlock*, unsigned bytecodeIndex, Identifier&);
+    
+    State m_state;
+    StructureSet m_structureSet;
+    size_t m_offset;
+    bool m_wasSeenInJIT;
+};
+
+} // namespace JSC
+
+#endif // PropertyAccessStatus_h
+