1 files changed, 205 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/dfg/DFGAbstractInterpreter.h b/Source/JavaScriptCore/dfg/DFGAbstractInterpreter.h
new file mode 100644
index 000000000..e1969179e
--- /dev/null
+++ b/Source/JavaScriptCore/dfg/DFGAbstractInterpreter.h
@@ -0,0 +1,205 @@
+/*
+ * Copyright (C) 2013-2015 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 DFGAbstractInterpreter_h
+#define DFGAbstractInterpreter_h
+
+#if ENABLE(DFG_JIT)
+
+#include "DFGAbstractValue.h"
+#include "DFGBranchDirection.h"
+#include "DFGGraph.h"
+#include "DFGNode.h"
+#include "DFGPhiChildren.h"
+
+namespace JSC { namespace DFG {
+
+template<typename AbstractStateType>
+class AbstractInterpreter {
+public:
+    AbstractInterpreter(Graph&, AbstractStateType&);
+    ~AbstractInterpreter();
+    
+    AbstractValue& forNode(Node* node)
+    {
+        return m_state.forNode(node);
+    }
+    
+    AbstractValue& forNode(Edge edge)
+    {
+        return forNode(edge.node());
+    }
+    
+    Operands<AbstractValue>& variables()
+    {
+        return m_state.variables();
+    }
+    
+    bool needsTypeCheck(Node* node, SpeculatedType typesPassedThrough)
+    {
+        return !forNode(node).isType(typesPassedThrough);
+    }
+    
+    bool needsTypeCheck(Edge edge, SpeculatedType typesPassedThrough)
+    {
+        return needsTypeCheck(edge.node(), typesPassedThrough);
+    }
+    
+    bool needsTypeCheck(Edge edge)
+    {
+        return needsTypeCheck(edge, typeFilterFor(edge.useKind()));
+    }
+    
+    // Abstractly executes the given node. The new abstract state is stored into an
+    // abstract stack stored in *this. Loads of local variables (that span
+    // basic blocks) interrogate the basic block's notion of the state at the head.
+    // Stores to local variables are handled in endBasicBlock(). This returns true
+    // if execution should continue past this node. Notably, it will return true
+    // for block terminals, so long as those terminals are not Return or Unreachable.
+    //
+    // This is guaranteed to be equivalent to doing:
+    //
+    // state.startExecuting()
+    // state.executeEdges(index);
+    // result = state.executeEffects(index);
+    bool execute(unsigned indexInBlock);
+    bool execute(Node*);
+    
+    // Indicate the start of execution of a node. It resets any state in the node
+    // that is progressively built up by executeEdges() and executeEffects().
+    void startExecuting();
+    
+    // Abstractly execute the edges of the given node. This runs filterEdgeByUse()
+    // on all edges of the node. You can skip this step, if you have already used
+    // filterEdgeByUse() (or some equivalent) on each edge.
+    void executeEdges(Node*);
+    void executeEdges(unsigned indexInBlock);
+    
+    ALWAYS_INLINE void filterEdgeByUse(Edge& edge)
+    {
+        ASSERT(mayHaveTypeCheck(edge.useKind()) || !needsTypeCheck(edge));
+        filterByType(edge, typeFilterFor(edge.useKind()));
+    }
+    ALWAYS_INLINE void filterEdgeByUse(Node*, Edge& edge)
+    {
+        filterEdgeByUse(edge);
+    }
+    
+    // Abstractly execute the effects of the given node. This changes the abstract
+    // state assuming that edges have already been filtered.
+    bool executeEffects(unsigned indexInBlock);
+    bool executeEffects(unsigned clobberLimit, Node*);
+    
+    void dump(PrintStream& out) const;
+    void dump(PrintStream& out);
+    
+    template<typename T>
+    FiltrationResult filter(T node, const StructureSet& set, SpeculatedType admittedTypes = SpecNone)
+    {
+        return filter(forNode(node), set, admittedTypes);
+    }
+    
+    template<typename T>
+    FiltrationResult filterArrayModes(T node, ArrayModes arrayModes)
+    {
+        return filterArrayModes(forNode(node), arrayModes);
+    }
+    
+    template<typename T>
+    FiltrationResult filter(T node, SpeculatedType type)
+    {
+        return filter(forNode(node), type);
+    }
+    
+    template<typename T>
+    FiltrationResult filterByValue(T node, FrozenValue value)
+    {
+        return filterByValue(forNode(node), value);
+    }
+    
+    FiltrationResult filter(AbstractValue&, const StructureSet&, SpeculatedType admittedTypes = SpecNone);
+    FiltrationResult filterArrayModes(AbstractValue&, ArrayModes);
+    FiltrationResult filter(AbstractValue&, SpeculatedType);
+    FiltrationResult filterByValue(AbstractValue&, FrozenValue);
+    
+    PhiChildren* phiChildren() { return m_phiChildren.get(); }
+    
+private:
+    void clobberWorld(const CodeOrigin&, unsigned indexInBlock);
+    
+    template<typename Functor>
+    void forAllValues(unsigned indexInBlock, Functor&);
+    
+    void clobberStructures(unsigned indexInBlock);
+    void observeTransition(unsigned indexInBlock, Structure* from, Structure* to);
+    void observeTransitions(unsigned indexInBlock, const TransitionVector&);
+    void setDidClobber();
+    
+    enum BooleanResult {
+        UnknownBooleanResult,
+        DefinitelyFalse,
+        DefinitelyTrue
+    };
+    BooleanResult booleanResult(Node*, AbstractValue&);
+    
+    void setBuiltInConstant(Node* node, FrozenValue value)
+    {
+        AbstractValue& abstractValue = forNode(node);
+        abstractValue.set(m_graph, value, m_state.structureClobberState());
+        abstractValue.fixTypeForRepresentation(m_graph, node);
+    }
+    
+    void setConstant(Node* node, FrozenValue value)
+    {
+        setBuiltInConstant(node, value);
+        m_state.setFoundConstants(true);
+    }
+    
+    ALWAYS_INLINE void filterByType(Edge& edge, SpeculatedType type)
+    {
+        AbstractValue& value = forNode(edge);
+        if (!value.isType(type))
+            edge.setProofStatus(NeedsCheck);
+        else
+            edge.setProofStatus(IsProved);
+        
+        filter(value, type);
+    }
+    
+    void verifyEdge(Node*, Edge);
+    void verifyEdges(Node*);
+    
+    CodeBlock* m_codeBlock;
+    Graph& m_graph;
+    AbstractStateType& m_state;
+    std::unique_ptr<PhiChildren> m_phiChildren;
+};
+
+} } // namespace JSC::DFG
+
+#endif // ENABLE(DFG_JIT)
+
+#endif // DFGAbstractInterpreter_h
+