JavaScriptCore-7601.1.46.3.tar.gz

[apple/javascriptcore.git] / runtime / JSEnvironmentRecord.h

diff --git a/runtime/JSEnvironmentRecord.h b/runtime/JSEnvironmentRecord.h
new file mode 100644 (file)
index 0000000..35807ba
--- /dev/null
+++ b/runtime/JSEnvironmentRecord.h
@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2007, 2008, 2012, 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. 
+ * 3.  Neither the name of Apple Inc. ("Apple") nor the names of
+ *     its contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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 JSEnvironmentRecord_h
+#define JSEnvironmentRecord_h
+
+#include "JSObject.h"
+#include "JSSymbolTableObject.h"
+#include "Register.h"
+#include "SymbolTable.h"
+
+namespace JSC {
+
+class LLIntOffsetsExtractor;
+class Register;
+
+class JSEnvironmentRecord : public JSSymbolTableObject {
+    friend class JIT;
+    friend class LLIntOffsetsExtractor;
+
+public:
+    typedef JSSymbolTableObject Base;
+    static const unsigned StructureFlags = Base::StructureFlags;
+
+    WriteBarrierBase<Unknown>* variables()
+    {
+        return bitwise_cast<WriteBarrierBase<Unknown>*>(bitwise_cast<char*>(this) + offsetOfVariables());
+    }
+    
+    bool isValid(ScopeOffset offset)
+    {
+        return !!offset && offset.offset() < symbolTable()->scopeSize();
+    }
+    
+    WriteBarrierBase<Unknown>& variableAt(ScopeOffset offset)
+    {
+        ASSERT(isValid(offset));
+        return variables()[offset.offset()];
+    }
+
+    static size_t offsetOfVariables()
+    {
+        return WTF::roundUpToMultipleOf<sizeof(WriteBarrier<Unknown>)>(sizeof(JSEnvironmentRecord));
+    }
+    
+    static ptrdiff_t offsetOfVariable(ScopeOffset offset)
+    {
+        return offsetOfVariables() + offset.offset() * sizeof(WriteBarrier<Unknown>);
+    }
+
+    DECLARE_INFO;
+
+    static size_t allocationSizeForScopeSize(unsigned scopeSize)
+    {
+        return offsetOfVariables() + scopeSize * sizeof(WriteBarrier<Unknown>);
+    }
+    
+    static size_t allocationSize(SymbolTable* symbolTable)
+    {
+        return allocationSizeForScopeSize(symbolTable->scopeSize());
+    }
+    
+protected:
+    JSEnvironmentRecord(
+        VM& vm,
+        Structure* structure,
+        JSScope* scope,
+        SymbolTable* symbolTable)
+        : Base(vm, structure, scope, symbolTable)
+    {
+    }
+    
+    void finishCreationUninitialized(VM& vm)
+    {
+        Base::finishCreation(vm);
+    }
+    
+    void finishCreation(VM& vm)
+    {
+        finishCreationUninitialized(vm);
+        for (unsigned i = symbolTable()->scopeSize(); i--;) {
+            // Filling this with undefined is useful because that's what variables start out as.
+            variableAt(ScopeOffset(i)).setUndefined();
+        }
+    }
+
+    static void visitChildren(JSCell*, SlotVisitor&);
+};
+
+} // namespace JSC
+
+#endif // JSEnvironmentRecord_h