JavaScriptCore-7601.1.46.3.tar.gz

[apple/javascriptcore.git] / interpreter / CallFrame.h

diff --git a/interpreter/CallFrame.h b/interpreter/CallFrame.h
index c09132c579320d16ce11f9f253a4d955dc6656cf..806ccead6fb33f44e8b3338823c4ea3b2bfb6fd4 100644 (file)
--- a/interpreter/CallFrame.h
+++ b/interpreter/CallFrame.h
@@ -1,7 +1,7 @@
 /*
  *  Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
  *  Copyright (C) 2001 Peter Kelly (pmk@post.com)
 /*
  *  Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
  *  Copyright (C) 2001 Peter Kelly (pmk@post.com)

- *  Copyright (C) 2003, 2007, 2008, 2011 Apple Inc. All rights reserved.
+ *  Copyright (C) 2003, 2007, 2008, 2011, 2013, 2014 Apple Inc. All rights reserved.

  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Library General Public


@@ -24,15 +24,17 @@
 #define CallFrame_h
 
 #include "AbstractPC.h"
 #define CallFrame_h
 
 #include "AbstractPC.h"

-#include "VM.h"

 #include "JSStack.h"
 #include "MacroAssemblerCodeRef.h"
 #include "Register.h"
 #include "JSStack.h"
 #include "MacroAssemblerCodeRef.h"
 #include "Register.h"

+#include "StackVisitor.h"
+#include "VM.h"
+#include "VMEntryRecord.h"

 
 namespace JSC  {
 
     class Arguments;
 
 namespace JSC  {
 
     class Arguments;

-    class JSActivation;
+    class JSLexicalEnvironment;

     class Interpreter;
     class JSScope;
 
     class Interpreter;
     class JSScope;
 


@@ -41,19 +43,24 @@ namespace JSC  {
     class ExecState : private Register {
     public:
         JSValue calleeAsValue() const { return this[JSStack::Callee].jsValue(); }
     class ExecState : private Register {
     public:
         JSValue calleeAsValue() const { return this[JSStack::Callee].jsValue(); }

-        JSObject* callee() const { return this[JSStack::Callee].function(); }
+        JSObject* callee() const { return this[JSStack::Callee].object(); }

         CodeBlock* codeBlock() const { return this[JSStack::CodeBlock].Register::codeBlock(); }
         CodeBlock* codeBlock() const { return this[JSStack::CodeBlock].Register::codeBlock(); }

-        JSScope* scope() const
+        JSScope* scope(int scopeRegisterOffset) const

         {
         {

-            ASSERT(this[JSStack::ScopeChain].Register::scope());
-            return this[JSStack::ScopeChain].Register::scope();
+            ASSERT(this[scopeRegisterOffset].Register::scope());
+            return this[scopeRegisterOffset].Register::scope();

         }
 
         }
 

+        bool hasActivation() const;
+        JSLexicalEnvironment* lexicalEnvironment() const;
+        JSLexicalEnvironment* lexicalEnvironmentOrNullptr() const;
+        JSValue uncheckedActivation() const;
+

         // Global object in which execution began.
         // Global object in which execution began.

-        JSGlobalObject* dynamicGlobalObject();
+        JS_EXPORT_PRIVATE JSGlobalObject* vmEntryGlobalObject();

 
         // Global object in which the currently executing code was defined.
 
         // Global object in which the currently executing code was defined.

-        // Differs from dynamicGlobalObject() during function calls across web browser frames.
+        // Differs from vmEntryGlobalObject() during function calls across web browser frames.

         JSGlobalObject* lexicalGlobalObject() const;
 
         // Differs from lexicalGlobalObject because this will have DOM window shell rather than
         JSGlobalObject* lexicalGlobalObject() const;
 
         // Differs from lexicalGlobalObject because this will have DOM window shell rather than


@@ -67,91 +74,102 @@ namespace JSC  {
         // pointer, so these are inefficient, and should be used sparingly in new code.
         // But they're used in many places in legacy code, so they're not going away any time soon.
 
         // pointer, so these are inefficient, and should be used sparingly in new code.
         // But they're used in many places in legacy code, so they're not going away any time soon.
 

-        void clearException() { vm().exception = JSValue(); }
-        void clearSupplementaryExceptionInfo()
-        {
-            vm().clearExceptionStack();
-        }
+        void clearException() { vm().clearException(); }
+
+        Exception* exception() const { return vm().exception(); }
+        bool hadException() const { return !!vm().exception(); }

 
 

-        JSValue exception() const { return vm().exception; }
-        bool hadException() const { return vm().exception; }
+        Exception* lastException() const { return vm().lastException(); }
+        void clearLastException() { vm().clearLastException(); }

 
 

+        AtomicStringTable* atomicStringTable() const { return vm().atomicStringTable(); }

         const CommonIdentifiers& propertyNames() const { return *vm().propertyNames; }
         const MarkedArgumentBuffer& emptyList() const { return *vm().emptyList; }
         Interpreter* interpreter() { return vm().interpreter; }
         Heap* heap() { return &vm().heap; }
         const CommonIdentifiers& propertyNames() const { return *vm().propertyNames; }
         const MarkedArgumentBuffer& emptyList() const { return *vm().emptyList; }
         Interpreter* interpreter() { return vm().interpreter; }
         Heap* heap() { return &vm().heap; }

-#ifndef NDEBUG
-        void dumpCaller();
-#endif
-        static const HashTable* arrayConstructorTable(CallFrame* callFrame) { return callFrame->vm().arrayConstructorTable; }
-        static const HashTable* arrayPrototypeTable(CallFrame* callFrame) { return callFrame->vm().arrayPrototypeTable; }
-        static const HashTable* booleanPrototypeTable(CallFrame* callFrame) { return callFrame->vm().booleanPrototypeTable; }
-        static const HashTable* dateTable(CallFrame* callFrame) { return callFrame->vm().dateTable; }
-        static const HashTable* dateConstructorTable(CallFrame* callFrame) { return callFrame->vm().dateConstructorTable; }
-        static const HashTable* errorPrototypeTable(CallFrame* callFrame) { return callFrame->vm().errorPrototypeTable; }
-        static const HashTable* globalObjectTable(CallFrame* callFrame) { return callFrame->vm().globalObjectTable; }
-        static const HashTable* jsonTable(CallFrame* callFrame) { return callFrame->vm().jsonTable; }
-        static const HashTable* mathTable(CallFrame* callFrame) { return callFrame->vm().mathTable; }
-        static const HashTable* numberConstructorTable(CallFrame* callFrame) { return callFrame->vm().numberConstructorTable; }
-        static const HashTable* numberPrototypeTable(CallFrame* callFrame) { return callFrame->vm().numberPrototypeTable; }
-        static const HashTable* objectConstructorTable(CallFrame* callFrame) { return callFrame->vm().objectConstructorTable; }
-        static const HashTable* privateNamePrototypeTable(CallFrame* callFrame) { return callFrame->vm().privateNamePrototypeTable; }
-        static const HashTable* regExpTable(CallFrame* callFrame) { return callFrame->vm().regExpTable; }
-        static const HashTable* regExpConstructorTable(CallFrame* callFrame) { return callFrame->vm().regExpConstructorTable; }
-        static const HashTable* regExpPrototypeTable(CallFrame* callFrame) { return callFrame->vm().regExpPrototypeTable; }
-        static const HashTable* stringConstructorTable(CallFrame* callFrame) { return callFrame->vm().stringConstructorTable; }
+

 
         static CallFrame* create(Register* callFrameBase) { return static_cast<CallFrame*>(callFrameBase); }
         Register* registers() { return this; }
 
         static CallFrame* create(Register* callFrameBase) { return static_cast<CallFrame*>(callFrameBase); }
         Register* registers() { return this; }

+        const Register* registers() const { return this; }

 
         CallFrame& operator=(const Register& r) { *static_cast<Register*>(this) = r; return *this; }
 
 
         CallFrame& operator=(const Register& r) { *static_cast<Register*>(this) = r; return *this; }
 

-        CallFrame* callerFrame() const { return this[JSStack::CallerFrame].callFrame(); }
-#if ENABLE(JIT) || ENABLE(LLINT)
-        ReturnAddressPtr returnPC() const { return ReturnAddressPtr(this[JSStack::ReturnPC].vPC()); }
-        bool hasReturnPC() const { return !!this[JSStack::ReturnPC].vPC(); }
-        void clearReturnPC() { registers()[JSStack::ReturnPC] = static_cast<Instruction*>(0); }
-#endif
+        CallFrame* callerFrame() const { return static_cast<CallFrame*>(callerFrameOrVMEntryFrame()); }
+
+        JS_EXPORT_PRIVATE CallFrame* callerFrame(VMEntryFrame*&);
+
+        static ptrdiff_t callerFrameOffset() { return OBJECT_OFFSETOF(CallerFrameAndPC, callerFrame); }
+
+        ReturnAddressPtr returnPC() const { return ReturnAddressPtr(callerFrameAndPC().pc); }
+        bool hasReturnPC() const { return !!callerFrameAndPC().pc; }
+        void clearReturnPC() { callerFrameAndPC().pc = 0; }
+        static ptrdiff_t returnPCOffset() { return OBJECT_OFFSETOF(CallerFrameAndPC, pc); }

         AbstractPC abstractReturnPC(VM& vm) { return AbstractPC(vm, this); }
         AbstractPC abstractReturnPC(VM& vm) { return AbstractPC(vm, this); }

-#if USE(JSVALUE32_64)
-        unsigned bytecodeOffsetForNonDFGCode() const;
-        void setBytecodeOffsetForNonDFGCode(unsigned offset);
+
+        class Location {
+        public:
+            static inline uint32_t decode(uint32_t bits);
+
+            static inline bool isBytecodeLocation(uint32_t bits);
+#if USE(JSVALUE64)
+            static inline uint32_t encodeAsBytecodeOffset(uint32_t bits);

 #else
 #else

-        unsigned bytecodeOffsetForNonDFGCode() const
-        {
-            ASSERT(codeBlock());
-            return this[JSStack::ArgumentCount].tag();
-        }
-        
-        void setBytecodeOffsetForNonDFGCode(unsigned offset)
-        {
-            ASSERT(codeBlock());
-            this[JSStack::ArgumentCount].tag() = static_cast<int32_t>(offset);
-        }
+            static inline uint32_t encodeAsBytecodeInstruction(Instruction*);

 #endif
 
 #endif
 

-        Register* frameExtent()
+            static inline bool isCodeOriginIndex(uint32_t bits);
+            static inline uint32_t encodeAsCodeOriginIndex(uint32_t bits);
+
+        private:
+            enum TypeTag {
+                BytecodeLocationTag = 0,
+                CodeOriginIndexTag = 1,
+            };
+
+            static inline uint32_t encode(TypeTag, uint32_t bits);
+
+            static const uint32_t s_mask = 0x1;
+#if USE(JSVALUE64)
+            static const uint32_t s_shift = 31;
+            static const uint32_t s_shiftedMask = s_mask << s_shift;
+#else
+            static const uint32_t s_shift = 1;
+#endif
+        };
+
+        bool hasLocationAsBytecodeOffset() const;
+        bool hasLocationAsCodeOriginIndex() const;
+
+        unsigned locationAsRawBits() const;
+        unsigned locationAsBytecodeOffset() const;
+        unsigned locationAsCodeOriginIndex() const;
+
+        void setLocationAsRawBits(unsigned);
+        void setLocationAsBytecodeOffset(unsigned);
+
+#if ENABLE(DFG_JIT)
+        unsigned bytecodeOffsetFromCodeOriginIndex();
+#endif
+        
+        // This will try to get you the bytecode offset, but you should be aware that
+        // this bytecode offset may be bogus in the presence of inlining. This will
+        // also return 0 if the call frame has no notion of bytecode offsets (for
+        // example if it's native code).
+        // https://bugs.webkit.org/show_bug.cgi?id=121754
+        unsigned bytecodeOffset();
+        
+        // This will get you a CodeOrigin. It will always succeed. May return
+        // CodeOrigin(0) if we're in native code.
+        CodeOrigin codeOrigin();
+
+        Register* topOfFrame()

         {
             if (!codeBlock())
                 return registers();
         {
             if (!codeBlock())
                 return registers();

-            return frameExtentInternal();
+            return topOfFrameInternal();

         }
     
         }
     

-        Register* frameExtentInternal();
-    
-#if ENABLE(DFG_JIT)
-        InlineCallFrame* inlineCallFrame() const { return this[JSStack::ReturnPC].asInlineCallFrame(); }
-        unsigned codeOriginIndexForDFG() const { return this[JSStack::ArgumentCount].tag(); }
-#else
-        // This will never be called if !ENABLE(DFG_JIT) since all calls should be guarded by
-        // isInlineCallFrame(). But to make it easier to write code without having a bunch of
-        // #if's, we make a dummy implementation available anyway.
-        InlineCallFrame* inlineCallFrame() const
-        {
-            RELEASE_ASSERT_NOT_REACHED();
-            return 0;
-        }
-#endif

 #if USE(JSVALUE32_64)
         Instruction* currentVPC() const
         {
 #if USE(JSVALUE32_64)
         Instruction* currentVPC() const
         {


@@ -166,33 +184,34 @@ namespace JSC  {
         void setCurrentVPC(Instruction* vpc);
 #endif
 
         void setCurrentVPC(Instruction* vpc);
 #endif
 

-        void setCallerFrame(CallFrame* callerFrame) { static_cast<Register*>(this)[JSStack::CallerFrame] = callerFrame; }
-        void setScope(JSScope* scope) { static_cast<Register*>(this)[JSStack::ScopeChain] = scope; }
+        void setCallerFrame(CallFrame* frame) { callerFrameAndPC().callerFrame = frame; }
+        void setScope(int scopeRegisterOffset, JSScope* scope) { static_cast<Register*>(this)[scopeRegisterOffset] = scope; }
+        void setActivation(JSLexicalEnvironment*);

 
 

-        ALWAYS_INLINE void init(CodeBlock* codeBlock, Instruction* vPC, JSScope* scope,
-            CallFrame* callerFrame, int argc, JSObject* callee)
-        {
-            ASSERT(callerFrame); // Use noCaller() rather than 0 for the outer host call frame caller.
-            ASSERT(callerFrame == noCaller() || callerFrame->removeHostCallFrameFlag()->stack()->end() >= this);
-
-            setCodeBlock(codeBlock);
-            setScope(scope);
-            setCallerFrame(callerFrame);
-            setReturnPC(vPC); // This is either an Instruction* or a pointer into JIT generated code stored as an Instruction*.
-            setArgumentCountIncludingThis(argc); // original argument count (for the sake of the "arguments" object)
-            setCallee(callee);
+        ALWAYS_INLINE void init(CodeBlock* codeBlock, Instruction* vPC,
+            CallFrame* callerFrame, int argc, JSObject* callee) 
+        { 
+            ASSERT(callerFrame == noCaller() || callerFrame->stack()->containsAddress(this)); 
+
+            setCodeBlock(codeBlock); 
+            setCallerFrame(callerFrame); 
+            setReturnPC(vPC); // This is either an Instruction* or a pointer into JIT generated code stored as an Instruction*. 
+            setArgumentCountIncludingThis(argc); // original argument count (for the sake of the "arguments" object) 
+            setCallee(callee); 

         }
 
         // Read a register from the codeframe (or constant from the CodeBlock).
         Register& r(int);
         }
 
         // Read a register from the codeframe (or constant from the CodeBlock).
         Register& r(int);

-        // Read a register for a non-constant 
+        Register& r(VirtualRegister);
+        // Read a register for a non-constant

         Register& uncheckedR(int);
         Register& uncheckedR(int);

+        Register& uncheckedR(VirtualRegister);

 
         // Access to arguments as passed. (After capture, arguments may move to a different location.)
         size_t argumentCount() const { return argumentCountIncludingThis() - 1; }
         size_t argumentCountIncludingThis() const { return this[JSStack::ArgumentCount].payload(); }
 
         // Access to arguments as passed. (After capture, arguments may move to a different location.)
         size_t argumentCount() const { return argumentCountIncludingThis() - 1; }
         size_t argumentCountIncludingThis() const { return this[JSStack::ArgumentCount].payload(); }

-        static int argumentOffset(int argument) { return s_firstArgumentOffset - argument; }
-        static int argumentOffsetIncludingThis(int argument) { return s_thisArgumentOffset - argument; }
+        static int argumentOffset(int argument) { return (JSStack::FirstArgument + argument); }
+        static int argumentOffsetIncludingThis(int argument) { return (JSStack::ThisArgument + argument); }

 
         // In the following (argument() and setArgument()), the 'argument'
         // parameter is the index of the arguments of the target function of
 
         // In the following (argument() and setArgument()), the 'argument'
         // parameter is the index of the arguments of the target function of


@@ -207,85 +226,63 @@ namespace JSC  {
         {
             if (argument >= argumentCount())
                  return jsUndefined();
         {
             if (argument >= argumentCount())
                  return jsUndefined();

-            return this[argumentOffset(argument)].jsValue();
+            return getArgumentUnsafe(argument);
+        }
+        JSValue uncheckedArgument(size_t argument)
+        {
+            ASSERT(argument < argumentCount());
+            return getArgumentUnsafe(argument);

         }
         void setArgument(size_t argument, JSValue value)
         {
             this[argumentOffset(argument)] = value;
         }
 
         }
         void setArgument(size_t argument, JSValue value)
         {
             this[argumentOffset(argument)] = value;
         }
 

+        JSValue getArgumentUnsafe(size_t argIndex)
+        {
+            // User beware! This method does not verify that there is a valid
+            // argument at the specified argIndex. This is used for debugging
+            // and verification code only. The caller is expected to know what
+            // he/she is doing when calling this method.
+            return this[argumentOffset(argIndex)].jsValue();
+        }
+

         static int thisArgumentOffset() { return argumentOffsetIncludingThis(0); }
         JSValue thisValue() { return this[thisArgumentOffset()].jsValue(); }
         void setThisValue(JSValue value) { this[thisArgumentOffset()] = value; }
 
         JSValue argumentAfterCapture(size_t argument);
 
         static int thisArgumentOffset() { return argumentOffsetIncludingThis(0); }
         JSValue thisValue() { return this[thisArgumentOffset()].jsValue(); }
         void setThisValue(JSValue value) { this[thisArgumentOffset()] = value; }
 
         JSValue argumentAfterCapture(size_t argument);
 

-        static int offsetFor(size_t argumentCountIncludingThis) { return argumentCountIncludingThis + JSStack::CallFrameHeaderSize; }
-
-        // FIXME: Remove these.
-        int hostThisRegister() { return thisArgumentOffset(); }
-        JSValue hostThisValue() { return thisValue(); }
-
-        static CallFrame* noCaller() { return reinterpret_cast<CallFrame*>(HostCallFrameFlag); }
+        static int offsetFor(size_t argumentCountIncludingThis) { return argumentCountIncludingThis + JSStack::ThisArgument - 1; }

 
 

-        bool hasHostCallFrameFlag() const { return reinterpret_cast<intptr_t>(this) & HostCallFrameFlag; }
-        CallFrame* addHostCallFrameFlag() const { return reinterpret_cast<CallFrame*>(reinterpret_cast<intptr_t>(this) | HostCallFrameFlag); }
-        CallFrame* removeHostCallFrameFlag() { return reinterpret_cast<CallFrame*>(reinterpret_cast<intptr_t>(this) & ~HostCallFrameFlag); }
+        static CallFrame* noCaller() { return 0; }

 
         void setArgumentCountIncludingThis(int count) { static_cast<Register*>(this)[JSStack::ArgumentCount].payload() = count; }
 
         void setArgumentCountIncludingThis(int count) { static_cast<Register*>(this)[JSStack::ArgumentCount].payload() = count; }

-        void setCallee(JSObject* callee) { static_cast<Register*>(this)[JSStack::Callee] = Register::withCallee(callee); }
+        void setCallee(JSObject* callee) { static_cast<Register*>(this)[JSStack::Callee] = callee; }

         void setCodeBlock(CodeBlock* codeBlock) { static_cast<Register*>(this)[JSStack::CodeBlock] = codeBlock; }
         void setCodeBlock(CodeBlock* codeBlock) { static_cast<Register*>(this)[JSStack::CodeBlock] = codeBlock; }

-        void setReturnPC(void* value) { static_cast<Register*>(this)[JSStack::ReturnPC] = (Instruction*)value; }
-        
-#if ENABLE(DFG_JIT)
-        bool isInlineCallFrame();
-        
-        void setInlineCallFrame(InlineCallFrame* inlineCallFrame) { static_cast<Register*>(this)[JSStack::ReturnPC] = inlineCallFrame; }
-        
-        // Call this to get the semantically correct JS CallFrame* for the
-        // currently executing function.
-        CallFrame* trueCallFrame(AbstractPC);
-        
-        // Call this to get the semantically correct JS CallFrame* corresponding
-        // to the caller. This resolves issues surrounding inlining and the
-        // HostCallFrameFlag stuff.
-        CallFrame* trueCallerFrame();
-        
-        CodeBlock* someCodeBlockForPossiblyInlinedCode();
-#else
-        bool isInlineCallFrame() { return false; }
-        
-        CallFrame* trueCallFrame(AbstractPC) { return this; }
-        CallFrame* trueCallerFrame() { return callerFrame()->removeHostCallFrameFlag(); }
-        
-        CodeBlock* someCodeBlockForPossiblyInlinedCode() { return codeBlock(); }
-#endif
-        CallFrame* callerFrameNoFlags() { return callerFrame()->removeHostCallFrameFlag(); }
-        
-        // Call this to get the true call frame (accounted for inlining and any
-        // other optimizations), when you have entered into VM code through one
-        // of the "blessed" entrypoints (JITStubs or DFGOperations). This means
-        // that if you're pretty much anywhere in the VM you can safely call this;
-        // though if you were to magically get an ExecState* by, say, interrupting
-        // a thread that is running JS code and brutishly scraped the call frame
-        // register, calling this method would probably lead to horrible things
-        // happening.
-        CallFrame* trueCallFrameFromVMCode() { return trueCallFrame(AbstractPC()); }
+        void setReturnPC(void* value) { callerFrameAndPC().pc = reinterpret_cast<Instruction*>(value); }
+
+        // CallFrame::iterate() expects a Functor that implements the following method:
+        //     StackVisitor::Status operator()(StackVisitor&);
+
+        template <typename Functor> void iterate(Functor& functor)
+        {
+            StackVisitor::visit<Functor>(this, functor);
+        }
+
+        void dump(PrintStream&);
+        JS_EXPORT_PRIVATE const char* describeFrame();

 
     private:
 
     private:

-        static const intptr_t HostCallFrameFlag = 1;
-        static const int s_thisArgumentOffset = -1 - JSStack::CallFrameHeaderSize;
-        static const int s_firstArgumentOffset = s_thisArgumentOffset - 1;

 
 #ifndef NDEBUG
         JSStack* stack();
 
 #ifndef NDEBUG
         JSStack* stack();

-#endif
-#if ENABLE(DFG_JIT)
-        bool isInlineCallFrameSlow();

 #endif
         ExecState();
         ~ExecState();
 
 #endif
         ExecState();
         ~ExecState();
 

+        Register* topOfFrameInternal();
+

         // The following are for internal use in debugging and verification
         // code only and not meant as an API for general usage:
 
         // The following are for internal use in debugging and verification
         // code only and not meant as an API for general usage:
 


@@ -299,24 +296,19 @@ namespace JSC  {
             int offset = reg - this->registers();
 
             // The offset is defined (based on argumentOffset()) to be:
             int offset = reg - this->registers();
 
             // The offset is defined (based on argumentOffset()) to be:

-            //       offset = s_firstArgumentOffset - argIndex;
+            //       offset = JSStack::FirstArgument - argIndex;

             // Hence:
             // Hence:

-            //       argIndex = s_firstArgumentOffset - offset;
-            size_t argIndex = s_firstArgumentOffset - offset;
+            //       argIndex = JSStack::FirstArgument - offset;
+            size_t argIndex = offset - JSStack::FirstArgument;

             return argIndex;
         }
 
             return argIndex;
         }
 

-        JSValue getArgumentUnsafe(size_t argIndex)
-        {
-            // User beware! This method does not verify that there is a valid
-            // argument at the specified argIndex. This is used for debugging
-            // and verification code only. The caller is expected to know what
-            // he/she is doing when calling this method.
-            return this[argumentOffset(argIndex)].jsValue();
-        }
+        void* callerFrameOrVMEntryFrame() const { return callerFrameAndPC().callerFrame; }
+
+        CallerFrameAndPC& callerFrameAndPC() { return *reinterpret_cast<CallerFrameAndPC*>(this); }
+        const CallerFrameAndPC& callerFrameAndPC() const { return *reinterpret_cast<const CallerFrameAndPC*>(this); }

 
         friend class JSStack;
 
         friend class JSStack;

-        friend class VMInspector;

     };
 
 } // namespace JSC
     };
 
 } // namespace JSC