1 files changed, 165 insertions, 203 deletions

diff --git a/Source/JavaScriptCore/bytecode/UnlinkedCodeBlock.cpp b/Source/JavaScriptCore/bytecode/UnlinkedCodeBlock.cpp
index 1dfb5ac6a..53defbfb3 100644
--- a/Source/JavaScriptCore/bytecode/UnlinkedCodeBlock.cpp
+++ b/Source/JavaScriptCore/bytecode/UnlinkedCodeBlock.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012, 2013 Apple Inc. All Rights Reserved.
+ * Copyright (C) 2012-2013, 2015-2016 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -28,191 +28,52 @@
 #include "UnlinkedCodeBlock.h"
 
 #include "BytecodeGenerator.h"
+#include "BytecodeRewriter.h"
 #include "ClassInfo.h"
 #include "CodeCache.h"
-#include "Executable.h"
+#include "ExecutableInfo.h"
+#include "FunctionOverrides.h"
+#include "JSCInlines.h"
 #include "JSString.h"
-#include "Operations.h"
 #include "Parser.h"
+#include "PreciseJumpTargetsInlines.h"
 #include "SourceProvider.h"
 #include "Structure.h"
 #include "SymbolTable.h"
+#include "UnlinkedEvalCodeBlock.h"
+#include "UnlinkedFunctionCodeBlock.h"
 #include "UnlinkedInstructionStream.h"
+#include "UnlinkedModuleProgramCodeBlock.h"
+#include "UnlinkedProgramCodeBlock.h"
 #include <wtf/DataLog.h>
 
 namespace JSC {
 
-const ClassInfo UnlinkedFunctionExecutable::s_info = { "UnlinkedFunctionExecutable", 0, 0, 0, CREATE_METHOD_TABLE(UnlinkedFunctionExecutable) };
-const ClassInfo UnlinkedCodeBlock::s_info = { "UnlinkedCodeBlock", 0, 0, 0, CREATE_METHOD_TABLE(UnlinkedCodeBlock) };
-const ClassInfo UnlinkedGlobalCodeBlock::s_info = { "UnlinkedGlobalCodeBlock", &Base::s_info, 0, 0, CREATE_METHOD_TABLE(UnlinkedGlobalCodeBlock) };
-const ClassInfo UnlinkedProgramCodeBlock::s_info = { "UnlinkedProgramCodeBlock", &Base::s_info, 0, 0, CREATE_METHOD_TABLE(UnlinkedProgramCodeBlock) };
-const ClassInfo UnlinkedEvalCodeBlock::s_info = { "UnlinkedEvalCodeBlock", &Base::s_info, 0, 0, CREATE_METHOD_TABLE(UnlinkedEvalCodeBlock) };
-const ClassInfo UnlinkedFunctionCodeBlock::s_info = { "UnlinkedFunctionCodeBlock", &Base::s_info, 0, 0, CREATE_METHOD_TABLE(UnlinkedFunctionCodeBlock) };
+const ClassInfo UnlinkedCodeBlock::s_info = { "UnlinkedCodeBlock", 0, 0, CREATE_METHOD_TABLE(UnlinkedCodeBlock) };
 
-static UnlinkedFunctionCodeBlock* generateFunctionCodeBlock(VM& vm, UnlinkedFunctionExecutable* executable, const SourceCode& source, CodeSpecializationKind kind, DebuggerMode debuggerMode, ProfilerMode profilerMode, ParserError& error)
-{
-    RefPtr<FunctionBodyNode> body = parse<FunctionBodyNode>(&vm, source, executable->parameters(), executable->name(), executable->isInStrictContext() ? JSParseStrict : JSParseNormal, JSParseFunctionCode, error);
-
-    if (!body) {
-        ASSERT(error.m_type != ParserError::ErrorNone);
-        return 0;
-    }
-
-    if (executable->forceUsesArguments())
-        body->setUsesArguments();
-    body->finishParsing(executable->parameters(), executable->name(), executable->functionNameIsInScopeToggle());
-    executable->recordParse(body->features(), body->hasCapturedVariables());
-    
-    UnlinkedFunctionCodeBlock* result = UnlinkedFunctionCodeBlock::create(&vm, FunctionCode, ExecutableInfo(body->needsActivation(), body->usesEval(), body->isStrictMode(), kind == CodeForConstruct));
-    OwnPtr<BytecodeGenerator> generator(adoptPtr(new BytecodeGenerator(vm, body.get(), result, debuggerMode, profilerMode)));
-    error = generator->generate();
-    body->destroyData();
-    if (error.m_type != ParserError::ErrorNone)
-        return 0;
-    return result;
-}
-
-unsigned UnlinkedCodeBlock::addOrFindConstant(JSValue v)
-{
-    unsigned numberOfConstants = numberOfConstantRegisters();
-    for (unsigned i = 0; i < numberOfConstants; ++i) {
-        if (getConstant(FirstConstantRegisterIndex + i) == v)
-            return i;
-    }
-    return addConstant(v);
-}
-
-UnlinkedFunctionExecutable::UnlinkedFunctionExecutable(VM* vm, Structure* structure, const SourceCode& source, FunctionBodyNode* node, bool isFromGlobalCode)
-    : Base(*vm, structure)
-    , m_numCapturedVariables(node->capturedVariableCount())
-    , m_forceUsesArguments(node->usesArguments())
-    , m_isInStrictContext(node->isStrictMode())
-    , m_hasCapturedVariables(node->hasCapturedVariables())
-    , m_isFromGlobalCode(isFromGlobalCode)
-    , m_name(node->ident())
-    , m_inferredName(node->inferredName())
-    , m_parameters(node->parameters())
-    , m_firstLineOffset(node->firstLine() - source.firstLine())
-    , m_lineCount(node->lastLine() - node->firstLine())
-    , m_unlinkedFunctionNameStart(node->functionNameStart() - source.startOffset())
-    , m_unlinkedBodyStartColumn(node->startColumn())
-    , m_unlinkedBodyEndColumn(m_lineCount ? node->endColumn() : node->endColumn() - node->startColumn())
-    , m_startOffset(node->source().startOffset() - source.startOffset())
-    , m_sourceLength(node->source().length())
-    , m_features(node->features())
-    , m_functionNameIsInScopeToggle(node->functionNameIsInScopeToggle())
-{
-}
-
-size_t UnlinkedFunctionExecutable::parameterCount() const
-{
-    return m_parameters->size();
-}
-
-void UnlinkedFunctionExecutable::visitChildren(JSCell* cell, SlotVisitor& visitor)
-{
-    UnlinkedFunctionExecutable* thisObject = jsCast<UnlinkedFunctionExecutable*>(cell);
-    ASSERT_GC_OBJECT_INHERITS(thisObject, info());
-    COMPILE_ASSERT(StructureFlags & OverridesVisitChildren, OverridesVisitChildrenWithoutSettingFlag);
-    ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
-    Base::visitChildren(thisObject, visitor);
-    visitor.append(&thisObject->m_codeBlockForCall);
-    visitor.append(&thisObject->m_codeBlockForConstruct);
-    visitor.append(&thisObject->m_nameValue);
-    visitor.append(&thisObject->m_symbolTableForCall);
-    visitor.append(&thisObject->m_symbolTableForConstruct);
-}
-
-FunctionExecutable* UnlinkedFunctionExecutable::link(VM& vm, const SourceCode& source, size_t lineOffset, size_t sourceOffset)
-{
-    unsigned firstLine = lineOffset + m_firstLineOffset;
-    unsigned startOffset = sourceOffset + m_startOffset;
-    bool startColumnIsOnFirstSourceLine = !m_firstLineOffset;
-    unsigned startColumn = m_unlinkedBodyStartColumn + (startColumnIsOnFirstSourceLine ? source.startColumn() : 1);
-    bool endColumnIsOnStartLine = !m_lineCount;
-    unsigned endColumn = m_unlinkedBodyEndColumn + (endColumnIsOnStartLine ? startColumn : 1);
-    SourceCode code(source.provider(), startOffset, startOffset + m_sourceLength, firstLine, startColumn);
-    return FunctionExecutable::create(vm, code, this, firstLine, firstLine + m_lineCount, startColumn, endColumn);
-}
-
-UnlinkedFunctionExecutable* UnlinkedFunctionExecutable::fromGlobalCode(const Identifier& name, ExecState* exec, Debugger*, const SourceCode& source, JSObject** exception)
-{
-    ParserError error;
-    VM& vm = exec->vm();
-    CodeCache* codeCache = vm.codeCache();
-    UnlinkedFunctionExecutable* executable = codeCache->getFunctionExecutableFromGlobalCode(vm, name, source, error);
-
-    if (exec->lexicalGlobalObject()->hasDebugger())
-        exec->lexicalGlobalObject()->debugger()->sourceParsed(exec, source.provider(), error.m_line, error.m_message);
-
-    if (error.m_type != ParserError::ErrorNone) {
-        *exception = error.toErrorObject(exec->lexicalGlobalObject(), source);
-        return 0;
-    }
-
-    return executable;
-}
-
-UnlinkedFunctionCodeBlock* UnlinkedFunctionExecutable::codeBlockFor(VM& vm, const SourceCode& source, CodeSpecializationKind specializationKind, DebuggerMode debuggerMode, ProfilerMode profilerMode, ParserError& error)
-{
-    switch (specializationKind) {
-    case CodeForCall:
-        if (UnlinkedFunctionCodeBlock* codeBlock = m_codeBlockForCall.get())
-            return codeBlock;
-        break;
-    case CodeForConstruct:
-        if (UnlinkedFunctionCodeBlock* codeBlock = m_codeBlockForConstruct.get())
-            return codeBlock;
-        break;
-    }
-
-    UnlinkedFunctionCodeBlock* result = generateFunctionCodeBlock(vm, this, source, specializationKind, debuggerMode, profilerMode, error);
-    
-    if (error.m_type != ParserError::ErrorNone)
-        return 0;
-
-    switch (specializationKind) {
-    case CodeForCall:
-        m_codeBlockForCall.set(vm, this, result);
-        m_symbolTableForCall.set(vm, this, result->symbolTable());
-        break;
-    case CodeForConstruct:
-        m_codeBlockForConstruct.set(vm, this, result);
-        m_symbolTableForConstruct.set(vm, this, result->symbolTable());
-        break;
-    }
-    return result;
-}
-
-String UnlinkedFunctionExecutable::paramString() const
-{
-    FunctionParameters& parameters = *m_parameters;
-    StringBuilder builder;
-    for (size_t pos = 0; pos < parameters.size(); ++pos) {
-        if (!builder.isEmpty())
-            builder.appendLiteral(", ");
-        parameters.at(pos)->toString(builder);
-    }
-    return builder.toString();
-}
-
-UnlinkedCodeBlock::UnlinkedCodeBlock(VM* vm, Structure* structure, CodeType codeType, const ExecutableInfo& info)
+UnlinkedCodeBlock::UnlinkedCodeBlock(VM* vm, Structure* structure, CodeType codeType, const ExecutableInfo& info, DebuggerMode debuggerMode)
     : Base(*vm, structure)
     , m_numVars(0)
-    , m_numCalleeRegisters(0)
+    , m_numCalleeLocals(0)
     , m_numParameters(0)
-    , m_vm(vm)
-    , m_argumentsRegister(VirtualRegister())
     , m_globalObjectRegister(VirtualRegister())
-    , m_needsFullScopeChain(info.m_needsActivation)
-    , m_usesEval(info.m_usesEval)
-    , m_isNumericCompareFunction(false)
-    , m_isStrictMode(info.m_isStrictMode)
-    , m_isConstructor(info.m_isConstructor)
+    , m_usesEval(info.usesEval())
+    , m_isStrictMode(info.isStrictMode())
+    , m_isConstructor(info.isConstructor())
     , m_hasCapturedVariables(false)
-    , m_firstLine(0)
+    , m_isBuiltinFunction(info.isBuiltinFunction())
+    , m_superBinding(static_cast<unsigned>(info.superBinding()))
+    , m_scriptMode(static_cast<unsigned>(info.scriptMode()))
+    , m_isArrowFunctionContext(info.isArrowFunctionContext())
+    , m_isClassContext(info.isClassContext())
+    , m_wasCompiledWithDebuggingOpcodes(debuggerMode == DebuggerMode::DebuggerOn || Options::forceDebuggerBytecodeGeneration())
+    , m_constructorKind(static_cast<unsigned>(info.constructorKind()))
+    , m_derivedContextType(static_cast<unsigned>(info.derivedContextType()))
+    , m_evalContextType(static_cast<unsigned>(info.evalContextType()))
     , m_lineCount(0)
     , m_endColumn(UINT_MAX)
+    , m_didOptimize(MixedTriState)
+    , m_parseMode(info.parseMode())
     , m_features(0)
     , m_codeType(codeType)
     , m_arrayProfileCount(0)
@@ -220,32 +81,38 @@ UnlinkedCodeBlock::UnlinkedCodeBlock(VM* vm, Structure* structure, CodeType code
     , m_objectAllocationProfileCount(0)
     , m_valueProfileCount(0)
     , m_llintCallLinkInfoCount(0)
-#if ENABLE(BYTECODE_COMMENTS)
-    , m_bytecodeCommentIterator(0)
-#endif
 {
-
+    for (auto& constantRegisterIndex : m_linkTimeConstants)
+        constantRegisterIndex = 0;
+    ASSERT(m_constructorKind == static_cast<unsigned>(info.constructorKind()));
 }
 
 void UnlinkedCodeBlock::visitChildren(JSCell* cell, SlotVisitor& visitor)
 {
     UnlinkedCodeBlock* thisObject = jsCast<UnlinkedCodeBlock*>(cell);
     ASSERT_GC_OBJECT_INHERITS(thisObject, info());
-    COMPILE_ASSERT(StructureFlags & OverridesVisitChildren, OverridesVisitChildrenWithoutSettingFlag);
-    ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
     Base::visitChildren(thisObject, visitor);
-    visitor.append(&thisObject->m_symbolTable);
+    auto locker = holdLock(*thisObject);
     for (FunctionExpressionVector::iterator ptr = thisObject->m_functionDecls.begin(), end = thisObject->m_functionDecls.end(); ptr != end; ++ptr)
-        visitor.append(ptr);
+        visitor.append(*ptr);
     for (FunctionExpressionVector::iterator ptr = thisObject->m_functionExprs.begin(), end = thisObject->m_functionExprs.end(); ptr != end; ++ptr)
-        visitor.append(ptr);
+        visitor.append(*ptr);
     visitor.appendValues(thisObject->m_constantRegisters.data(), thisObject->m_constantRegisters.size());
+    if (thisObject->m_unlinkedInstructions)
+        visitor.reportExtraMemoryVisited(thisObject->m_unlinkedInstructions->sizeInBytes());
     if (thisObject->m_rareData) {
         for (size_t i = 0, end = thisObject->m_rareData->m_regexps.size(); i != end; i++)
-            visitor.append(&thisObject->m_rareData->m_regexps[i]);
+            visitor.append(thisObject->m_rareData->m_regexps[i]);
     }
 }
 
+size_t UnlinkedCodeBlock::estimatedSize(JSCell* cell)
+{
+    UnlinkedCodeBlock* thisObject = jsCast<UnlinkedCodeBlock*>(cell);
+    size_t extraSize = thisObject->m_unlinkedInstructions ? thisObject->m_unlinkedInstructions->sizeInBytes() : 0;
+    return Base::estimatedSize(cell) + extraSize;
+}
+
 int UnlinkedCodeBlock::lineNumberForBytecodeOffset(unsigned bytecodeOffset)
 {
     ASSERT(bytecodeOffset < instructions().count());
@@ -258,8 +125,8 @@ int UnlinkedCodeBlock::lineNumberForBytecodeOffset(unsigned bytecodeOffset)
     return line;
 }
 
-inline void UnlinkedCodeBlock::getLineAndColumn(ExpressionRangeInfo& info,
-    unsigned& line, unsigned& column)
+inline void UnlinkedCodeBlock::getLineAndColumn(const ExpressionRangeInfo& info,
+    unsigned& line, unsigned& column) const
 {
     switch (info.mode) {
     case ExpressionRangeInfo::FatLineMode:
@@ -292,6 +159,7 @@ static void dumpLineColumnEntry(size_t index, const UnlinkedInstructionStream& i
         case DidReachBreakpoint: event = " DidReachBreakpoint"; break;
         case WillLeaveCallFrame: event = " WillLeaveCallFrame"; break;
         case WillExecuteStatement: event = " WillExecuteStatement"; break;
+        case WillExecuteExpression: event = " WillExecuteExpression"; break;
         }
     }
     dataLogF("  [%zu] pc %u @ line %u col %u : %s%s\n", index, instructionOffset, line, column, opcodeNames[opcode], event);
@@ -315,7 +183,7 @@ void UnlinkedCodeBlock::dumpExpressionRangeInfo()
 #endif
 
 void UnlinkedCodeBlock::expressionRangeForBytecodeOffset(unsigned bytecodeOffset,
-    int& divot, int& startOffset, int& endOffset, unsigned& line, unsigned& column)
+    int& divot, int& startOffset, int& endOffset, unsigned& line, unsigned& column) const
 {
     ASSERT(bytecodeOffset < instructions().count());
 
@@ -328,7 +196,7 @@ void UnlinkedCodeBlock::expressionRangeForBytecodeOffset(unsigned bytecodeOffset
         return;
     }
 
-    Vector<ExpressionRangeInfo>& expressionInfo = m_expressionInfo;
+    const Vector<ExpressionRangeInfo>& expressionInfo = m_expressionInfo;
 
     int low = 0;
     int high = expressionInfo.size();
@@ -343,7 +211,7 @@ void UnlinkedCodeBlock::expressionRangeForBytecodeOffset(unsigned bytecodeOffset
     if (!low)
         low = 1;
 
-    ExpressionRangeInfo& info = expressionInfo[low - 1];
+    const ExpressionRangeInfo& info = expressionInfo[low - 1];
     startOffset = info.startOffset;
     endOffset = info.endOffset;
     divot = info.divotPoint;
@@ -404,51 +272,145 @@ void UnlinkedCodeBlock::addExpressionInfo(unsigned instructionOffset,
     m_expressionInfo.append(info);
 }
 
-void UnlinkedProgramCodeBlock::visitChildren(JSCell* cell, SlotVisitor& visitor)
+bool UnlinkedCodeBlock::typeProfilerExpressionInfoForBytecodeOffset(unsigned bytecodeOffset, unsigned& startDivot, unsigned& endDivot)
 {
-    UnlinkedProgramCodeBlock* thisObject = jsCast<UnlinkedProgramCodeBlock*>(cell);
-    ASSERT_GC_OBJECT_INHERITS(thisObject, info());
-    COMPILE_ASSERT(StructureFlags & OverridesVisitChildren, OverridesVisitChildrenWithoutSettingFlag);
-    ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
-    Base::visitChildren(thisObject, visitor);
-    for (size_t i = 0, end = thisObject->m_functionDeclarations.size(); i != end; i++)
-        visitor.append(&thisObject->m_functionDeclarations[i].second);
+    static const bool verbose = false;
+    if (!m_rareData) {
+        if (verbose)
+            dataLogF("Don't have assignment info for offset:%u\n", bytecodeOffset);
+        startDivot = UINT_MAX;
+        endDivot = UINT_MAX;
+        return false;
+    }
+
+    auto iter = m_rareData->m_typeProfilerInfoMap.find(bytecodeOffset);
+    if (iter == m_rareData->m_typeProfilerInfoMap.end()) {
+        if (verbose)
+            dataLogF("Don't have assignment info for offset:%u\n", bytecodeOffset);
+        startDivot = UINT_MAX;
+        endDivot = UINT_MAX;
+        return false;
+    }
+    
+    RareData::TypeProfilerExpressionRange& range = iter->value;
+    startDivot = range.m_startDivot;
+    endDivot = range.m_endDivot;
+    return true;
 }
 
-UnlinkedCodeBlock::~UnlinkedCodeBlock()
+void UnlinkedCodeBlock::addTypeProfilerExpressionInfo(unsigned instructionOffset, unsigned startDivot, unsigned endDivot)
 {
+    createRareDataIfNecessary();
+    RareData::TypeProfilerExpressionRange range;
+    range.m_startDivot = startDivot;
+    range.m_endDivot = endDivot;
+    m_rareData->m_typeProfilerInfoMap.set(instructionOffset, range);
 }
 
-void UnlinkedProgramCodeBlock::destroy(JSCell* cell)
+UnlinkedCodeBlock::~UnlinkedCodeBlock()
 {
-    jsCast<UnlinkedProgramCodeBlock*>(cell)->~UnlinkedProgramCodeBlock();
 }
 
-void UnlinkedEvalCodeBlock::destroy(JSCell* cell)
+void UnlinkedCodeBlock::setInstructions(std::unique_ptr<UnlinkedInstructionStream> instructions)
 {
-    jsCast<UnlinkedEvalCodeBlock*>(cell)->~UnlinkedEvalCodeBlock();
+    ASSERT(instructions);
+    {
+        auto locker = holdLock(*this);
+        m_unlinkedInstructions = WTFMove(instructions);
+    }
+    Heap::heap(this)->reportExtraMemoryAllocated(m_unlinkedInstructions->sizeInBytes());
 }
 
-void UnlinkedFunctionCodeBlock::destroy(JSCell* cell)
+const UnlinkedInstructionStream& UnlinkedCodeBlock::instructions() const
 {
-    jsCast<UnlinkedFunctionCodeBlock*>(cell)->~UnlinkedFunctionCodeBlock();
+    ASSERT(m_unlinkedInstructions.get());
+    return *m_unlinkedInstructions;
 }
 
-void UnlinkedFunctionExecutable::destroy(JSCell* cell)
+UnlinkedHandlerInfo* UnlinkedCodeBlock::handlerForBytecodeOffset(unsigned bytecodeOffset, RequiredHandler requiredHandler)
 {
-    jsCast<UnlinkedFunctionExecutable*>(cell)->~UnlinkedFunctionExecutable();
+    return handlerForIndex(bytecodeOffset, requiredHandler);
 }
 
-void UnlinkedCodeBlock::setInstructions(std::unique_ptr<UnlinkedInstructionStream> instructions)
+UnlinkedHandlerInfo* UnlinkedCodeBlock::handlerForIndex(unsigned index, RequiredHandler requiredHandler)
 {
-    m_unlinkedInstructions = std::move(instructions);
+    if (!m_rareData)
+        return nullptr;
+    return UnlinkedHandlerInfo::handlerForIndex(m_rareData->m_exceptionHandlers, index, requiredHandler);
 }
 
-const UnlinkedInstructionStream& UnlinkedCodeBlock::instructions() const
+void UnlinkedCodeBlock::applyModification(BytecodeRewriter& rewriter)
 {
-    ASSERT(m_unlinkedInstructions.get());
-    return *m_unlinkedInstructions;
+    // Before applying the changes, we adjust the jumps based on the original bytecode offset, the offset to the jump target, and
+    // the insertion information.
+
+    BytecodeGraph<UnlinkedCodeBlock>& graph = rewriter.graph();
+    UnlinkedInstruction* instructionsBegin = graph.instructions().begin();
+
+    for (int bytecodeOffset = 0, instructionCount = graph.instructions().size(); bytecodeOffset < instructionCount;) {
+        UnlinkedInstruction* current = instructionsBegin + bytecodeOffset;
+        OpcodeID opcodeID = current[0].u.opcode;
+        extractStoredJumpTargetsForBytecodeOffset(this, vm()->interpreter, instructionsBegin, bytecodeOffset, [&](int32_t& relativeOffset) {
+            relativeOffset = rewriter.adjustJumpTarget(bytecodeOffset, bytecodeOffset + relativeOffset);
+        });
+        bytecodeOffset += opcodeLength(opcodeID);
+    }
+
+    // Then, exception handlers should be adjusted.
+    if (m_rareData) {
+        for (UnlinkedHandlerInfo& handler : m_rareData->m_exceptionHandlers) {
+            handler.target = rewriter.adjustAbsoluteOffset(handler.target);
+            handler.start = rewriter.adjustAbsoluteOffset(handler.start);
+            handler.end = rewriter.adjustAbsoluteOffset(handler.end);
+        }
+
+        for (size_t i = 0; i < m_rareData->m_opProfileControlFlowBytecodeOffsets.size(); ++i)
+            m_rareData->m_opProfileControlFlowBytecodeOffsets[i] = rewriter.adjustAbsoluteOffset(m_rareData->m_opProfileControlFlowBytecodeOffsets[i]);
+
+        if (!m_rareData->m_typeProfilerInfoMap.isEmpty()) {
+            HashMap<unsigned, RareData::TypeProfilerExpressionRange> adjustedTypeProfilerInfoMap;
+            for (auto& entry : m_rareData->m_typeProfilerInfoMap)
+                adjustedTypeProfilerInfoMap.set(rewriter.adjustAbsoluteOffset(entry.key), entry.value);
+            m_rareData->m_typeProfilerInfoMap.swap(adjustedTypeProfilerInfoMap);
+        }
+    }
+
+    for (size_t i = 0; i < m_propertyAccessInstructions.size(); ++i)
+        m_propertyAccessInstructions[i] = rewriter.adjustAbsoluteOffset(m_propertyAccessInstructions[i]);
+
+    for (size_t i = 0; i < m_expressionInfo.size(); ++i)
+        m_expressionInfo[i].instructionOffset = rewriter.adjustAbsoluteOffset(m_expressionInfo[i].instructionOffset);
+
+    // Then, modify the unlinked instructions.
+    rewriter.applyModification();
+
+    // And recompute the jump target based on the modified unlinked instructions.
+    m_jumpTargets.clear();
+    recomputePreciseJumpTargets(this, graph.instructions().begin(), graph.instructions().size(), m_jumpTargets);
 }
 
+void UnlinkedCodeBlock::shrinkToFit()
+{
+    auto locker = holdLock(*this);
+    
+    m_jumpTargets.shrinkToFit();
+    m_identifiers.shrinkToFit();
+    m_bitVectors.shrinkToFit();
+    m_constantRegisters.shrinkToFit();
+    m_constantsSourceCodeRepresentation.shrinkToFit();
+    m_functionDecls.shrinkToFit();
+    m_functionExprs.shrinkToFit();
+    m_propertyAccessInstructions.shrinkToFit();
+    m_expressionInfo.shrinkToFit();
+
+    if (m_rareData) {
+        m_rareData->m_exceptionHandlers.shrinkToFit();
+        m_rareData->m_regexps.shrinkToFit();
+        m_rareData->m_constantBuffers.shrinkToFit();
+        m_rareData->m_switchJumpTables.shrinkToFit();
+        m_rareData->m_stringSwitchJumpTables.shrinkToFit();
+        m_rareData->m_expressionInfoFatPositions.shrinkToFit();
+    }
 }
 
+} // namespace JSC