bytecompiler/BytecodeGenerator.h

   1 /*
   2  * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
   3  * Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1.  Redistributions of source code must retain the above copyright
  10  *     notice, this list of conditions and the following disclaimer.
  11  * 2.  Redistributions in binary form must reproduce the above copyright
  12  *     notice, this list of conditions and the following disclaimer in the
  13  *     documentation and/or other materials provided with the distribution.
  14  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  15  *     its contributors may be used to endorse or promote products derived
  16  *     from this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  19  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  21  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  25  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #ifndef BytecodeGenerator_h
  31 #define BytecodeGenerator_h
  32
  33 #include "CodeBlock.h"
  34 #include "HashTraits.h"
  35 #include "Instruction.h"
  36 #include "Label.h"
  37 #include "LabelScope.h"
  38 #include "Interpreter.h"
  39 #include "RegisterID.h"
  40 #include "SymbolTable.h"
  41 #include "Debugger.h"
  42 #include "Nodes.h"
  43 #include <wtf/FastAllocBase.h>
  44 #include <wtf/PassRefPtr.h>
  45 #include <wtf/SegmentedVector.h>
  46 #include <wtf/Vector.h>
  47
  48 namespace JSC {
  49
  50     class Identifier;
  51     class ScopeChain;
  52     class ScopeNode;
  53
  54     struct FinallyContext {
  55         Label* finallyAddr;
  56         RegisterID* retAddrDst;
  57     };
  58
  59     struct ControlFlowContext {
  60         bool isFinallyBlock;
  61         FinallyContext finallyContext;
  62     };
  63
  64     class BytecodeGenerator : public WTF::FastAllocBase {
  65     public:
  66         typedef DeclarationStacks::VarStack VarStack;
  67         typedef DeclarationStacks::FunctionStack FunctionStack;
  68
  69         static void setDumpsGeneratedCode(bool dumpsGeneratedCode);
  70         static bool dumpsGeneratedCode();
  71
  72         BytecodeGenerator(ProgramNode*, const Debugger*, const ScopeChain&, SymbolTable*, ProgramCodeBlock*);
  73         BytecodeGenerator(FunctionBodyNode*, const Debugger*, const ScopeChain&, SymbolTable*, CodeBlock*);
  74         BytecodeGenerator(EvalNode*, const Debugger*, const ScopeChain&, SymbolTable*, EvalCodeBlock*);
  75
  76         JSGlobalData* globalData() const { return m_globalData; }
  77         const CommonIdentifiers& propertyNames() const { return *m_globalData->propertyNames; }
  78
  79         void generate();
  80
  81         // Returns the register corresponding to a local variable, or 0 if no
  82         // such register exists. Registers returned by registerFor do not
  83         // require explicit reference counting.
  84         RegisterID* registerFor(const Identifier&);
  85
  86         bool willResolveToArguments(const Identifier&);
  87         RegisterID* uncheckedRegisterForArguments();
  88
  89         // Behaves as registerFor does, but ignores dynamic scope as
  90         // dynamic scope should not interfere with const initialisation
  91         RegisterID* constRegisterFor(const Identifier&);
  92
  93         // Searches the scope chain in an attempt to  statically locate the requested
  94         // property.  Returns false if for any reason the property cannot be safely
  95         // optimised at all.  Otherwise it will return the index and depth of the
  96         // VariableObject that defines the property.  If the property cannot be found
  97         // statically, depth will contain the depth of the scope chain where dynamic
  98         // lookup must begin.
  99         //
 100         // NB: depth does _not_ include the local scope.  eg. a depth of 0 refers
 101         // to the scope containing this codeblock.
 102         bool findScopedProperty(const Identifier&, int& index, size_t& depth, bool forWriting, JSObject*& globalObject);
 103
 104         // Returns the register storing "this"
 105         RegisterID* thisRegister() { return &m_thisRegister; }
 106
 107         bool isLocal(const Identifier&);
 108         bool isLocalConstant(const Identifier&);
 109
 110         // Returns the next available temporary register. Registers returned by
 111         // newTemporary require a modified form of reference counting: any
 112         // register with a refcount of 0 is considered "available", meaning that
 113         // the next instruction may overwrite it.
 114         RegisterID* newTemporary();
 115
 116         RegisterID* highestUsedRegister();
 117
 118         // The same as newTemporary(), but this function returns "suggestion" if
 119         // "suggestion" is a temporary. This function is helpful in situations
 120         // where you've put "suggestion" in a RefPtr, but you'd like to allow
 121         // the next instruction to overwrite it anyway.
 122         RegisterID* newTemporaryOr(RegisterID* suggestion) { return suggestion->isTemporary() ? suggestion : newTemporary(); }
 123
 124         // Functions for handling of dst register
 125
 126         RegisterID* ignoredResult() { return &m_ignoredResultRegister; }
 127
 128         // Returns a place to write intermediate values of an operation
 129         // which reuses dst if it is safe to do so.
 130         RegisterID* tempDestination(RegisterID* dst)
 131         {
 132             return (dst && dst != ignoredResult() && dst->isTemporary()) ? dst : newTemporary();
 133         }
 134
 135         // Returns the place to write the final output of an operation.
 136         RegisterID* finalDestination(RegisterID* originalDst, RegisterID* tempDst = 0)
 137         {
 138             if (originalDst && originalDst != ignoredResult())
 139                 return originalDst;
 140             ASSERT(tempDst != ignoredResult());
 141             if (tempDst && tempDst->isTemporary())
 142                 return tempDst;
 143             return newTemporary();
 144         }
 145
 146         RegisterID* destinationForAssignResult(RegisterID* dst)
 147         {
 148             if (dst && dst != ignoredResult() && m_codeBlock->needsFullScopeChain())
 149                 return dst->isTemporary() ? dst : newTemporary();
 150             return 0;
 151         }
 152
 153         // Moves src to dst if dst is not null and is different from src, otherwise just returns src.
 154         RegisterID* moveToDestinationIfNeeded(RegisterID* dst, RegisterID* src)
 155         {
 156             return dst == ignoredResult() ? 0 : (dst && dst != src) ? emitMove(dst, src) : src;
 157         }
 158
 159         PassRefPtr<LabelScope> newLabelScope(LabelScope::Type, const Identifier* = 0);
 160         PassRefPtr<Label> newLabel();
 161
 162         // The emitNode functions are just syntactic sugar for calling
 163         // Node::emitCode. These functions accept a 0 for the register,
 164         // meaning that the node should allocate a register, or ignoredResult(),
 165         // meaning that the node need not put the result in a register.
 166         // Other emit functions do not accept 0 or ignoredResult().
 167         RegisterID* emitNode(RegisterID* dst, Node* n)
 168         {
 169             // Node::emitCode assumes that dst, if provided, is either a local or a referenced temporary.
 170             ASSERT(!dst || dst == ignoredResult() || !dst->isTemporary() || dst->refCount());
 171             if (!m_codeBlock->numberOfLineInfos() || m_codeBlock->lastLineInfo().lineNumber != n->lineNo()) {
 172                 LineInfo info = { instructions().size(), n->lineNo() };
 173                 m_codeBlock->addLineInfo(info);
 174             }
 175             if (m_emitNodeDepth >= s_maxEmitNodeDepth)
 176                 return emitThrowExpressionTooDeepException();
 177             ++m_emitNodeDepth;
 178             RegisterID* r = n->emitBytecode(*this, dst);
 179             --m_emitNodeDepth;
 180             return r;
 181         }
 182
 183         RegisterID* emitNode(Node* n)
 184         {
 185             return emitNode(0, n);
 186         }
 187
 188         void emitExpressionInfo(unsigned divot, unsigned startOffset, unsigned endOffset)
 189         {
 190             divot -= m_codeBlock->sourceOffset();
 191             if (divot > ExpressionRangeInfo::MaxDivot) {
 192                 // Overflow has occurred, we can only give line number info for errors for this region
 193                 divot = 0;
 194                 startOffset = 0;
 195                 endOffset = 0;
 196             } else if (startOffset > ExpressionRangeInfo::MaxOffset) {
 197                 // If the start offset is out of bounds we clear both offsets
 198                 // so we only get the divot marker.  Error message will have to be reduced
 199                 // to line and column number.
 200                 startOffset = 0;
 201                 endOffset = 0;
 202             } else if (endOffset > ExpressionRangeInfo::MaxOffset) {
 203                 // The end offset is only used for additional context, and is much more likely
 204                 // to overflow (eg. function call arguments) so we are willing to drop it without
 205                 // dropping the rest of the range.
 206                 endOffset = 0;
 207             }
 208
 209             ExpressionRangeInfo info;
 210             info.instructionOffset = instructions().size();
 211             info.divotPoint = divot;
 212             info.startOffset = startOffset;
 213             info.endOffset = endOffset;
 214             m_codeBlock->addExpressionInfo(info);
 215         }
 216
 217         void emitGetByIdExceptionInfo(OpcodeID opcodeID)
 218         {
 219             // Only op_construct and op_instanceof need exception info for
 220             // a preceding op_get_by_id.
 221             ASSERT(opcodeID == op_construct || opcodeID == op_instanceof);
 222             GetByIdExceptionInfo info;
 223             info.bytecodeOffset = instructions().size();
 224             info.isOpConstruct = (opcodeID == op_construct);
 225             m_codeBlock->addGetByIdExceptionInfo(info);
 226         }
 227
 228         ALWAYS_INLINE bool leftHandSideNeedsCopy(bool rightHasAssignments, bool rightIsPure)
 229         {
 230             return (m_codeType != FunctionCode || m_codeBlock->needsFullScopeChain() || rightHasAssignments) && !rightIsPure;
 231         }
 232
 233         ALWAYS_INLINE PassRefPtr<RegisterID> emitNodeForLeftHandSide(ExpressionNode* n, bool rightHasAssignments, bool rightIsPure)
 234         {
 235             if (leftHandSideNeedsCopy(rightHasAssignments, rightIsPure)) {
 236                 PassRefPtr<RegisterID> dst = newTemporary();
 237                 emitNode(dst.get(), n);
 238                 return dst;
 239             }
 240
 241             return PassRefPtr<RegisterID>(emitNode(n));
 242         }
 243
 244         RegisterID* emitLoad(RegisterID* dst, bool);
 245         RegisterID* emitLoad(RegisterID* dst, double);
 246         RegisterID* emitLoad(RegisterID* dst, const Identifier&);
 247         RegisterID* emitLoad(RegisterID* dst, JSValue);
 248
 249         RegisterID* emitUnaryOp(OpcodeID, RegisterID* dst, RegisterID* src);
 250         RegisterID* emitBinaryOp(OpcodeID, RegisterID* dst, RegisterID* src1, RegisterID* src2, OperandTypes);
 251         RegisterID* emitEqualityOp(OpcodeID, RegisterID* dst, RegisterID* src1, RegisterID* src2);
 252         RegisterID* emitUnaryNoDstOp(OpcodeID, RegisterID* src);
 253
 254         RegisterID* emitNewObject(RegisterID* dst);
 255         RegisterID* emitNewArray(RegisterID* dst, ElementNode*); // stops at first elision
 256
 257         RegisterID* emitNewFunction(RegisterID* dst, FuncDeclNode* func);
 258         RegisterID* emitNewFunctionExpression(RegisterID* dst, FuncExprNode* func);
 259         RegisterID* emitNewRegExp(RegisterID* dst, RegExp* regExp);
 260
 261         RegisterID* emitMove(RegisterID* dst, RegisterID* src);
 262
 263         RegisterID* emitToJSNumber(RegisterID* dst, RegisterID* src) { return emitUnaryOp(op_to_jsnumber, dst, src); }
 264         RegisterID* emitPreInc(RegisterID* srcDst);
 265         RegisterID* emitPreDec(RegisterID* srcDst);
 266         RegisterID* emitPostInc(RegisterID* dst, RegisterID* srcDst);
 267         RegisterID* emitPostDec(RegisterID* dst, RegisterID* srcDst);
 268
 269         RegisterID* emitInstanceOf(RegisterID* dst, RegisterID* value, RegisterID* base, RegisterID* basePrototype);
 270         RegisterID* emitTypeOf(RegisterID* dst, RegisterID* src) { return emitUnaryOp(op_typeof, dst, src); }
 271         RegisterID* emitIn(RegisterID* dst, RegisterID* property, RegisterID* base) { return emitBinaryOp(op_in, dst, property, base, OperandTypes()); }
 272
 273         RegisterID* emitResolve(RegisterID* dst, const Identifier& property);
 274         RegisterID* emitGetScopedVar(RegisterID* dst, size_t skip, int index, JSValue globalObject);
 275         RegisterID* emitPutScopedVar(size_t skip, int index, RegisterID* value, JSValue globalObject);
 276
 277         RegisterID* emitResolveBase(RegisterID* dst, const Identifier& property);
 278         RegisterID* emitResolveWithBase(RegisterID* baseDst, RegisterID* propDst, const Identifier& property);
 279
 280         void emitMethodCheck();
 281
 282         RegisterID* emitGetById(RegisterID* dst, RegisterID* base, const Identifier& property);
 283         RegisterID* emitPutById(RegisterID* base, const Identifier& property, RegisterID* value);
 284         RegisterID* emitDeleteById(RegisterID* dst, RegisterID* base, const Identifier&);
 285         RegisterID* emitGetByVal(RegisterID* dst, RegisterID* base, RegisterID* property);
 286         RegisterID* emitPutByVal(RegisterID* base, RegisterID* property, RegisterID* value);
 287         RegisterID* emitDeleteByVal(RegisterID* dst, RegisterID* base, RegisterID* property);
 288         RegisterID* emitPutByIndex(RegisterID* base, unsigned index, RegisterID* value);
 289         RegisterID* emitPutGetter(RegisterID* base, const Identifier& property, RegisterID* value);
 290         RegisterID* emitPutSetter(RegisterID* base, const Identifier& property, RegisterID* value);
 291
 292         RegisterID* emitCall(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
 293         RegisterID* emitCallEval(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
 294         RegisterID* emitCallVarargs(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, RegisterID* argCount, unsigned divot, unsigned startOffset, unsigned endOffset);
 295         RegisterID* emitLoadVarargs(RegisterID* argCountDst, RegisterID* args);
 296
 297         RegisterID* emitReturn(RegisterID* src);
 298         RegisterID* emitEnd(RegisterID* src) { return emitUnaryNoDstOp(op_end, src); }
 299
 300         RegisterID* emitConstruct(RegisterID* dst, RegisterID* func, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
 301         RegisterID* emitStrcat(RegisterID* dst, RegisterID* src, int count);
 302         void emitToPrimitive(RegisterID* dst, RegisterID* src);
 303
 304         PassRefPtr<Label> emitLabel(Label*);
 305         PassRefPtr<Label> emitJump(Label* target);
 306         PassRefPtr<Label> emitJumpIfTrue(RegisterID* cond, Label* target);
 307         PassRefPtr<Label> emitJumpIfFalse(RegisterID* cond, Label* target);
 308         PassRefPtr<Label> emitJumpIfNotFunctionCall(RegisterID* cond, Label* target);
 309         PassRefPtr<Label> emitJumpIfNotFunctionApply(RegisterID* cond, Label* target);
 310         PassRefPtr<Label> emitJumpScopes(Label* target, int targetScopeDepth);
 311
 312         PassRefPtr<Label> emitJumpSubroutine(RegisterID* retAddrDst, Label*);
 313         void emitSubroutineReturn(RegisterID* retAddrSrc);
 314
 315         RegisterID* emitGetPropertyNames(RegisterID* dst, RegisterID* base) { return emitUnaryOp(op_get_pnames, dst, base); }
 316         RegisterID* emitNextPropertyName(RegisterID* dst, RegisterID* iter, Label* target);
 317
 318         RegisterID* emitCatch(RegisterID*, Label* start, Label* end);
 319         void emitThrow(RegisterID* exc) { emitUnaryNoDstOp(op_throw, exc); }
 320         RegisterID* emitNewError(RegisterID* dst, ErrorType type, JSValue message);
 321         void emitPushNewScope(RegisterID* dst, Identifier& property, RegisterID* value);
 322
 323         RegisterID* emitPushScope(RegisterID* scope);
 324         void emitPopScope();
 325
 326         void emitDebugHook(DebugHookID, int firstLine, int lastLine);
 327
 328         int scopeDepth() { return m_dynamicScopeDepth + m_finallyDepth; }
 329         bool hasFinaliser() { return m_finallyDepth != 0; }
 330
 331         void pushFinallyContext(Label* target, RegisterID* returnAddrDst);
 332         void popFinallyContext();
 333
 334         LabelScope* breakTarget(const Identifier&);
 335         LabelScope* continueTarget(const Identifier&);
 336
 337         void beginSwitch(RegisterID*, SwitchInfo::SwitchType);
 338         void endSwitch(uint32_t clauseCount, RefPtr<Label>*, ExpressionNode**, Label* defaultLabel, int32_t min, int32_t range);
 339
 340         CodeType codeType() const { return m_codeType; }
 341
 342         void setRegeneratingForExceptionInfo(CodeBlock* originalCodeBlock)
 343         {
 344             m_regeneratingForExceptionInfo = true;
 345             m_codeBlockBeingRegeneratedFrom = originalCodeBlock;
 346         }
 347
 348     private:
 349         void emitOpcode(OpcodeID);
 350         void retrieveLastBinaryOp(int& dstIndex, int& src1Index, int& src2Index);
 351         void retrieveLastUnaryOp(int& dstIndex, int& srcIndex);
 352         void rewindBinaryOp();
 353         void rewindUnaryOp();
 354
 355         PassRefPtr<Label> emitComplexJumpScopes(Label* target, ControlFlowContext* topScope, ControlFlowContext* bottomScope);
 356
 357         typedef HashMap<EncodedJSValue, unsigned, EncodedJSValueHash, EncodedJSValueHashTraits> JSValueMap;
 358
 359         struct IdentifierMapIndexHashTraits {
 360             typedef int TraitType;
 361             typedef IdentifierMapIndexHashTraits StorageTraits;
 362             static int emptyValue() { return std::numeric_limits<int>::max(); }
 363             static const bool emptyValueIsZero = false;
 364             static const bool needsDestruction = false;
 365             static const bool needsRef = false;
 366         };
 367
 368         typedef HashMap<RefPtr<UString::Rep>, int, IdentifierRepHash, HashTraits<RefPtr<UString::Rep> >, IdentifierMapIndexHashTraits> IdentifierMap;
 369         typedef HashMap<double, JSValue> NumberMap;
 370         typedef HashMap<UString::Rep*, JSString*, IdentifierRepHash> IdentifierStringMap;
 371
 372         RegisterID* emitCall(OpcodeID, RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
 373
 374         RegisterID* newRegister();
 375
 376         // Returns the RegisterID corresponding to ident.
 377         RegisterID* addVar(const Identifier& ident, bool isConstant)
 378         {
 379             RegisterID* local;
 380             addVar(ident, isConstant, local);
 381             return local;
 382         }
 383         // Returns true if a new RegisterID was added, false if a pre-existing RegisterID was re-used.
 384         bool addVar(const Identifier&, bool isConstant, RegisterID*&);
 385
 386         // Returns the RegisterID corresponding to ident.
 387         RegisterID* addGlobalVar(const Identifier& ident, bool isConstant)
 388         {
 389             RegisterID* local;
 390             addGlobalVar(ident, isConstant, local);
 391             return local;
 392         }
 393         // Returns true if a new RegisterID was added, false if a pre-existing RegisterID was re-used.
 394         bool addGlobalVar(const Identifier&, bool isConstant, RegisterID*&);
 395
 396         RegisterID* addParameter(const Identifier&);
 397
 398         void preserveLastVar();
 399
 400         RegisterID& registerFor(int index)
 401         {
 402             if (index >= 0)
 403                 return m_calleeRegisters[index];
 404
 405             if (index == RegisterFile::OptionalCalleeArguments)
 406                 return m_argumentsRegister;
 407
 408             if (m_parameters.size()) {
 409                 ASSERT(!m_globals.size());
 410                 return m_parameters[index + m_parameters.size() + RegisterFile::CallFrameHeaderSize];
 411             }
 412
 413             return m_globals[-index - 1];
 414         }
 415
 416         unsigned addConstant(FuncDeclNode*);
 417         unsigned addConstant(FuncExprNode*);
 418         unsigned addConstant(const Identifier&);
 419         RegisterID* addConstantValue(JSValue);
 420         unsigned addRegExp(RegExp*);
 421
 422         Vector<Instruction>& instructions() { return m_codeBlock->instructions(); }
 423         SymbolTable& symbolTable() { return *m_symbolTable; }
 424
 425         bool shouldOptimizeLocals() { return (m_codeType != EvalCode) && !m_dynamicScopeDepth; }
 426         bool canOptimizeNonLocals() { return (m_codeType == FunctionCode) && !m_dynamicScopeDepth && !m_codeBlock->usesEval(); }
 427
 428         RegisterID* emitThrowExpressionTooDeepException();
 429
 430         void createArgumentsIfNecessary();
 431
 432         bool m_shouldEmitDebugHooks;
 433         bool m_shouldEmitProfileHooks;
 434
 435         const ScopeChain* m_scopeChain;
 436         SymbolTable* m_symbolTable;
 437
 438         ScopeNode* m_scopeNode;
 439         CodeBlock* m_codeBlock;
 440
 441         // Some of these objects keep pointers to one another. They are arranged
 442         // to ensure a sane destruction order that avoids references to freed memory.
 443         HashSet<RefPtr<UString::Rep>, IdentifierRepHash> m_functions;
 444         RegisterID m_ignoredResultRegister;
 445         RegisterID m_thisRegister;
 446         RegisterID m_argumentsRegister;
 447         int m_activationRegisterIndex;
 448         WTF::SegmentedVector<RegisterID, 32> m_constantPoolRegisters;
 449         WTF::SegmentedVector<RegisterID, 32> m_calleeRegisters;
 450         WTF::SegmentedVector<RegisterID, 32> m_parameters;
 451         WTF::SegmentedVector<RegisterID, 32> m_globals;
 452         WTF::SegmentedVector<Label, 32> m_labels;
 453         WTF::SegmentedVector<LabelScope, 8> m_labelScopes;
 454         RefPtr<RegisterID> m_lastVar;
 455         int m_finallyDepth;
 456         int m_dynamicScopeDepth;
 457         int m_baseScopeDepth;
 458         CodeType m_codeType;
 459
 460         Vector<ControlFlowContext> m_scopeContextStack;
 461         Vector<SwitchInfo> m_switchContextStack;
 462
 463         int m_nextGlobalIndex;
 464         int m_nextParameterIndex;
 465         int m_firstConstantIndex;
 466         int m_nextConstantOffset;
 467         unsigned m_globalConstantIndex;
 468
 469         int m_globalVarStorageOffset;
 470
 471         // Constant pool
 472         IdentifierMap m_identifierMap;
 473         JSValueMap m_jsValueMap;
 474         NumberMap m_numberMap;
 475         IdentifierStringMap m_stringMap;
 476
 477         JSGlobalData* m_globalData;
 478
 479         OpcodeID m_lastOpcodeID;
 480
 481         unsigned m_emitNodeDepth;
 482
 483         bool m_regeneratingForExceptionInfo;
 484         CodeBlock* m_codeBlockBeingRegeneratedFrom;
 485
 486         static const unsigned s_maxEmitNodeDepth = 5000;
 487     };
 488
 489 }
 490
 491 #endif // BytecodeGenerator_h