Imported WebKit commit 2ea9d364d0f6efa8fa64acf19f451504c59be0e4 (http://svn.webkit.org/repository/webkit/trunk@104285)

1 files changed, 756 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/runtime/Executable.cpp b/Source/JavaScriptCore/runtime/Executable.cpp
new file mode 100644
index 000000000..ad86463db
--- /dev/null
+++ b/Source/JavaScriptCore/runtime/Executable.cpp
@@ -0,0 +1,756 @@
+/*
+ * Copyright (C) 2009, 2010 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. 
+ */
+
+#include "config.h"
+#include "Executable.h"
+
+#include "BytecodeGenerator.h"
+#include "CodeBlock.h"
+#include "DFGDriver.h"
+#include "JIT.h"
+#include "Parser.h"
+#include "UStringBuilder.h"
+#include "Vector.h"
+
+namespace JSC {
+
+const ClassInfo ExecutableBase::s_info = { "Executable", 0, 0, 0, CREATE_METHOD_TABLE(ExecutableBase) };
+
+void ExecutableBase::destroy(JSCell* cell)
+{
+    jsCast<ExecutableBase*>(cell)->ExecutableBase::~ExecutableBase();
+}
+
+inline void ExecutableBase::clearCode()
+{
+#if ENABLE(JIT)
+    m_jitCodeForCall.clear();
+    m_jitCodeForConstruct.clear();
+    m_jitCodeForCallWithArityCheck = MacroAssemblerCodePtr();
+    m_jitCodeForConstructWithArityCheck = MacroAssemblerCodePtr();
+#endif
+    m_numParametersForCall = NUM_PARAMETERS_NOT_COMPILED;
+    m_numParametersForConstruct = NUM_PARAMETERS_NOT_COMPILED;
+}
+
+#if ENABLE(DFG_JIT)
+Intrinsic ExecutableBase::intrinsic() const
+{
+    if (const NativeExecutable* nativeExecutable = jsDynamicCast<const NativeExecutable*>(this))
+        return nativeExecutable->intrinsic();
+    return NoIntrinsic;
+}
+#endif
+
+const ClassInfo NativeExecutable::s_info = { "NativeExecutable", &ExecutableBase::s_info, 0, 0, CREATE_METHOD_TABLE(NativeExecutable) };
+
+void NativeExecutable::destroy(JSCell* cell)
+{
+    jsCast<NativeExecutable*>(cell)->NativeExecutable::~NativeExecutable();
+}
+
+#if ENABLE(DFG_JIT)
+Intrinsic NativeExecutable::intrinsic() const
+{
+    return m_intrinsic;
+}
+#endif
+
+#if ENABLE(JIT)
+// Utility method used for jettisoning code blocks.
+template<typename T>
+static void jettisonCodeBlock(JSGlobalData& globalData, OwnPtr<T>& codeBlock)
+{
+    ASSERT(codeBlock->getJITType() != JITCode::BaselineJIT);
+    ASSERT(codeBlock->alternative());
+    OwnPtr<T> codeBlockToJettison = codeBlock.release();
+    codeBlock = static_pointer_cast<T>(codeBlockToJettison->releaseAlternative());
+    codeBlockToJettison->unlinkIncomingCalls();
+    globalData.heap.jettisonDFGCodeBlock(static_pointer_cast<CodeBlock>(codeBlockToJettison.release()));
+}
+#endif
+
+void NativeExecutable::finalize(JSCell* cell)
+{
+    jsCast<NativeExecutable*>(cell)->clearCode();
+}
+
+const ClassInfo ScriptExecutable::s_info = { "ScriptExecutable", &ExecutableBase::s_info, 0, 0, CREATE_METHOD_TABLE(ScriptExecutable) };
+
+void ScriptExecutable::destroy(JSCell* cell)
+{
+    jsCast<ScriptExecutable*>(cell)->ScriptExecutable::~ScriptExecutable();
+}
+
+const ClassInfo EvalExecutable::s_info = { "EvalExecutable", &ScriptExecutable::s_info, 0, 0, CREATE_METHOD_TABLE(EvalExecutable) };
+
+EvalExecutable::EvalExecutable(ExecState* exec, const SourceCode& source, bool inStrictContext)
+    : ScriptExecutable(exec->globalData().evalExecutableStructure.get(), exec, source, inStrictContext)
+{
+}
+
+void EvalExecutable::destroy(JSCell* cell)
+{
+    jsCast<EvalExecutable*>(cell)->EvalExecutable::~EvalExecutable();
+}
+
+const ClassInfo ProgramExecutable::s_info = { "ProgramExecutable", &ScriptExecutable::s_info, 0, 0, CREATE_METHOD_TABLE(ProgramExecutable) };
+
+ProgramExecutable::ProgramExecutable(ExecState* exec, const SourceCode& source)
+    : ScriptExecutable(exec->globalData().programExecutableStructure.get(), exec, source, false)
+{
+}
+
+void ProgramExecutable::destroy(JSCell* cell)
+{
+    jsCast<ProgramExecutable*>(cell)->ProgramExecutable::~ProgramExecutable();
+}
+
+const ClassInfo FunctionExecutable::s_info = { "FunctionExecutable", &ScriptExecutable::s_info, 0, 0, CREATE_METHOD_TABLE(FunctionExecutable) };
+
+FunctionExecutable::FunctionExecutable(JSGlobalData& globalData, const Identifier& name, const SourceCode& source, bool forceUsesArguments, FunctionParameters* parameters, bool inStrictContext)
+    : ScriptExecutable(globalData.functionExecutableStructure.get(), globalData, source, inStrictContext)
+    , m_numCapturedVariables(0)
+    , m_forceUsesArguments(forceUsesArguments)
+    , m_parameters(parameters)
+    , m_name(name)
+    , m_symbolTable(0)
+{
+}
+
+FunctionExecutable::FunctionExecutable(ExecState* exec, const Identifier& name, const SourceCode& source, bool forceUsesArguments, FunctionParameters* parameters, bool inStrictContext)
+    : ScriptExecutable(exec->globalData().functionExecutableStructure.get(), exec, source, inStrictContext)
+    , m_numCapturedVariables(0)
+    , m_forceUsesArguments(forceUsesArguments)
+    , m_parameters(parameters)
+    , m_name(name)
+    , m_symbolTable(0)
+{
+}
+
+void FunctionExecutable::destroy(JSCell* cell)
+{
+    jsCast<FunctionExecutable*>(cell)->FunctionExecutable::~FunctionExecutable();
+}
+
+JSObject* EvalExecutable::compileOptimized(ExecState* exec, ScopeChainNode* scopeChainNode)
+{
+    ASSERT(exec->globalData().dynamicGlobalObject);
+    ASSERT(!!m_evalCodeBlock);
+    JSObject* error = 0;
+    if (m_evalCodeBlock->getJITType() != JITCode::topTierJIT())
+        error = compileInternal(exec, scopeChainNode, JITCode::nextTierJIT(m_evalCodeBlock->getJITType()));
+    ASSERT(!!m_evalCodeBlock);
+    return error;
+}
+
+JSObject* EvalExecutable::compileInternal(ExecState* exec, ScopeChainNode* scopeChainNode, JITCode::JITType jitType)
+{
+    SamplingRegion samplingRegion(jitType == JITCode::BaselineJIT ? "Baseline Compilation (TOTAL)" : "DFG Compilation (TOTAL)");
+    
+#if !ENABLE(JIT)
+    UNUSED_PARAM(jitType);
+#endif
+    JSObject* exception = 0;
+    JSGlobalData* globalData = &exec->globalData();
+    JSGlobalObject* lexicalGlobalObject = exec->lexicalGlobalObject();
+    
+    if (!!m_evalCodeBlock && m_evalCodeBlock->canProduceCopyWithBytecode()) {
+        BytecodeDestructionBlocker blocker(m_evalCodeBlock.get());
+        OwnPtr<EvalCodeBlock> newCodeBlock = adoptPtr(new EvalCodeBlock(CodeBlock::CopyParsedBlock, *m_evalCodeBlock));
+        newCodeBlock->setAlternative(static_pointer_cast<CodeBlock>(m_evalCodeBlock.release()));
+        m_evalCodeBlock = newCodeBlock.release();
+    } else {
+        if (!lexicalGlobalObject->evalEnabled())
+            return throwError(exec, createEvalError(exec, "Eval is disabled"));
+        RefPtr<EvalNode> evalNode = parse<EvalNode>(globalData, lexicalGlobalObject, m_source, 0, isStrictMode() ? JSParseStrict : JSParseNormal, EvalNode::isFunctionNode ? JSParseFunctionCode : JSParseProgramCode, lexicalGlobalObject->debugger(), exec, &exception);
+        if (!evalNode) {
+            ASSERT(exception);
+            return exception;
+        }
+        recordParse(evalNode->features(), evalNode->hasCapturedVariables(), evalNode->lineNo(), evalNode->lastLine());
+        
+        JSGlobalObject* globalObject = scopeChainNode->globalObject.get();
+        
+        OwnPtr<CodeBlock> previousCodeBlock = m_evalCodeBlock.release();
+        ASSERT((jitType == JITCode::bottomTierJIT()) == !previousCodeBlock);
+        m_evalCodeBlock = adoptPtr(new EvalCodeBlock(this, globalObject, source().provider(), scopeChainNode->localDepth(), previousCodeBlock.release()));
+        OwnPtr<BytecodeGenerator> generator(adoptPtr(new BytecodeGenerator(evalNode.get(), scopeChainNode, m_evalCodeBlock->symbolTable(), m_evalCodeBlock.get(), !!m_evalCodeBlock->alternative() ? OptimizingCompilation : FirstCompilation)));
+        if ((exception = generator->generate())) {
+            m_evalCodeBlock = static_pointer_cast<EvalCodeBlock>(m_evalCodeBlock->releaseAlternative());
+            evalNode->destroyData();
+            return exception;
+        }
+        
+        evalNode->destroyData();
+        m_evalCodeBlock->copyPostParseDataFromAlternative();
+    }
+
+#if ENABLE(JIT)
+    if (exec->globalData().canUseJIT()) {
+        bool dfgCompiled = false;
+        if (jitType == JITCode::DFGJIT)
+            dfgCompiled = DFG::tryCompile(exec, m_evalCodeBlock.get(), m_jitCodeForCall);
+        if (dfgCompiled)
+            ASSERT(!m_evalCodeBlock->alternative() || !m_evalCodeBlock->alternative()->hasIncomingCalls());
+        else {
+            if (m_evalCodeBlock->alternative()) {
+                // There is already an alternative piece of code compiled with a different
+                // JIT, so we can silently fail.
+                m_evalCodeBlock = static_pointer_cast<EvalCodeBlock>(m_evalCodeBlock->releaseAlternative());
+                return 0;
+            }
+            m_jitCodeForCall = JIT::compile(scopeChainNode->globalData, m_evalCodeBlock.get());
+        }
+#if !ENABLE(OPCODE_SAMPLING)
+        if (!BytecodeGenerator::dumpsGeneratedCode())
+            m_evalCodeBlock->handleBytecodeDiscardingOpportunity();
+#endif
+        m_evalCodeBlock->setJITCode(m_jitCodeForCall, MacroAssemblerCodePtr());
+    }
+#endif
+
+#if ENABLE(JIT)
+#if ENABLE(INTERPRETER)
+    if (!m_jitCodeForCall)
+        Heap::heap(this)->reportExtraMemoryCost(sizeof(*m_evalCodeBlock));
+    else
+#endif
+    Heap::heap(this)->reportExtraMemoryCost(sizeof(*m_evalCodeBlock) + m_jitCodeForCall.size());
+#else
+    Heap::heap(this)->reportExtraMemoryCost(sizeof(*m_evalCodeBlock));
+#endif
+
+    return 0;
+}
+
+#if ENABLE(JIT)
+void EvalExecutable::jettisonOptimizedCode(JSGlobalData& globalData)
+{
+    jettisonCodeBlock(globalData, m_evalCodeBlock);
+    m_jitCodeForCall = m_evalCodeBlock->getJITCode();
+    ASSERT(!m_jitCodeForCallWithArityCheck);
+}
+#endif
+
+void EvalExecutable::visitChildren(JSCell* cell, SlotVisitor& visitor)
+{
+    EvalExecutable* thisObject = jsCast<EvalExecutable*>(cell);
+    ASSERT_GC_OBJECT_INHERITS(thisObject, &s_info);
+    COMPILE_ASSERT(StructureFlags & OverridesVisitChildren, OverridesVisitChildrenWithoutSettingFlag);
+    ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
+    ScriptExecutable::visitChildren(thisObject, visitor);
+    if (thisObject->m_evalCodeBlock)
+        thisObject->m_evalCodeBlock->visitAggregate(visitor);
+}
+
+void EvalExecutable::unlinkCalls()
+{
+#if ENABLE(JIT)
+    if (!m_jitCodeForCall)
+        return;
+    ASSERT(m_evalCodeBlock);
+    m_evalCodeBlock->unlinkCalls();
+#endif
+}
+
+void EvalExecutable::finalize(JSCell* cell)
+{
+    jsCast<EvalExecutable*>(cell)->clearCode();
+}
+
+inline void EvalExecutable::clearCode()
+{
+    if (m_evalCodeBlock) {
+        m_evalCodeBlock->clearEvalCache();
+        m_evalCodeBlock.clear();
+    }
+    Base::clearCode();
+}
+
+JSObject* ProgramExecutable::checkSyntax(ExecState* exec)
+{
+    JSObject* exception = 0;
+    JSGlobalData* globalData = &exec->globalData();
+    JSGlobalObject* lexicalGlobalObject = exec->lexicalGlobalObject();
+    RefPtr<ProgramNode> programNode = parse<ProgramNode>(globalData, lexicalGlobalObject, m_source, 0, JSParseNormal, ProgramNode::isFunctionNode ? JSParseFunctionCode : JSParseProgramCode, lexicalGlobalObject->debugger(), exec, &exception);
+    if (programNode)
+        return 0;
+    ASSERT(exception);
+    return exception;
+}
+
+JSObject* ProgramExecutable::compileOptimized(ExecState* exec, ScopeChainNode* scopeChainNode)
+{
+    ASSERT(exec->globalData().dynamicGlobalObject);
+    ASSERT(!!m_programCodeBlock);
+    JSObject* error = 0;
+    if (m_programCodeBlock->getJITType() != JITCode::topTierJIT())
+        error = compileInternal(exec, scopeChainNode, JITCode::nextTierJIT(m_programCodeBlock->getJITType()));
+    ASSERT(!!m_programCodeBlock);
+    return error;
+}
+
+JSObject* ProgramExecutable::compileInternal(ExecState* exec, ScopeChainNode* scopeChainNode, JITCode::JITType jitType)
+{
+    SamplingRegion samplingRegion(jitType == JITCode::BaselineJIT ? "Baseline Compilation (TOTAL)" : "DFG Compilation (TOTAL)");
+    
+#if !ENABLE(JIT)
+    UNUSED_PARAM(jitType);
+#endif
+    JSObject* exception = 0;
+    JSGlobalData* globalData = &exec->globalData();
+    JSGlobalObject* lexicalGlobalObject = exec->lexicalGlobalObject();
+    
+    if (!!m_programCodeBlock && m_programCodeBlock->canProduceCopyWithBytecode()) {
+        BytecodeDestructionBlocker blocker(m_programCodeBlock.get());
+        OwnPtr<ProgramCodeBlock> newCodeBlock = adoptPtr(new ProgramCodeBlock(CodeBlock::CopyParsedBlock, *m_programCodeBlock));
+        newCodeBlock->setAlternative(static_pointer_cast<CodeBlock>(m_programCodeBlock.release()));
+        m_programCodeBlock = newCodeBlock.release();
+    } else {
+        RefPtr<ProgramNode> programNode = parse<ProgramNode>(globalData, lexicalGlobalObject, m_source, 0, isStrictMode() ? JSParseStrict : JSParseNormal, ProgramNode::isFunctionNode ? JSParseFunctionCode : JSParseProgramCode, lexicalGlobalObject->debugger(), exec, &exception);
+        if (!programNode) {
+            ASSERT(exception);
+            return exception;
+        }
+        recordParse(programNode->features(), programNode->hasCapturedVariables(), programNode->lineNo(), programNode->lastLine());
+
+        JSGlobalObject* globalObject = scopeChainNode->globalObject.get();
+    
+        OwnPtr<CodeBlock> previousCodeBlock = m_programCodeBlock.release();
+        ASSERT((jitType == JITCode::bottomTierJIT()) == !previousCodeBlock);
+        m_programCodeBlock = adoptPtr(new ProgramCodeBlock(this, GlobalCode, globalObject, source().provider(), previousCodeBlock.release()));
+        OwnPtr<BytecodeGenerator> generator(adoptPtr(new BytecodeGenerator(programNode.get(), scopeChainNode, &globalObject->symbolTable(), m_programCodeBlock.get(), !!m_programCodeBlock->alternative() ? OptimizingCompilation : FirstCompilation)));
+        if ((exception = generator->generate())) {
+            m_programCodeBlock = static_pointer_cast<ProgramCodeBlock>(m_programCodeBlock->releaseAlternative());
+            programNode->destroyData();
+            return exception;
+        }
+
+        programNode->destroyData();
+        m_programCodeBlock->copyPostParseDataFromAlternative();
+    }
+
+#if ENABLE(JIT)
+    if (exec->globalData().canUseJIT()) {
+        bool dfgCompiled = false;
+        if (jitType == JITCode::DFGJIT)
+            dfgCompiled = DFG::tryCompile(exec, m_programCodeBlock.get(), m_jitCodeForCall);
+        if (dfgCompiled) {
+            if (m_programCodeBlock->alternative())
+                m_programCodeBlock->alternative()->unlinkIncomingCalls();
+        } else {
+            if (m_programCodeBlock->alternative()) {
+                m_programCodeBlock = static_pointer_cast<ProgramCodeBlock>(m_programCodeBlock->releaseAlternative());
+                return 0;
+            }
+            m_jitCodeForCall = JIT::compile(scopeChainNode->globalData, m_programCodeBlock.get());
+        }
+#if !ENABLE(OPCODE_SAMPLING)
+        if (!BytecodeGenerator::dumpsGeneratedCode())
+            m_programCodeBlock->handleBytecodeDiscardingOpportunity();
+#endif
+        m_programCodeBlock->setJITCode(m_jitCodeForCall, MacroAssemblerCodePtr());
+    }
+#endif
+
+#if ENABLE(JIT)
+#if ENABLE(INTERPRETER)
+    if (!m_jitCodeForCall)
+        Heap::heap(this)->reportExtraMemoryCost(sizeof(*m_programCodeBlock));
+    else
+#endif
+        Heap::heap(this)->reportExtraMemoryCost(sizeof(*m_programCodeBlock) + m_jitCodeForCall.size());
+#else
+    Heap::heap(this)->reportExtraMemoryCost(sizeof(*m_programCodeBlock));
+#endif
+
+    return 0;
+}
+
+#if ENABLE(JIT)
+void ProgramExecutable::jettisonOptimizedCode(JSGlobalData& globalData)
+{
+    jettisonCodeBlock(globalData, m_programCodeBlock);
+    m_jitCodeForCall = m_programCodeBlock->getJITCode();
+    ASSERT(!m_jitCodeForCallWithArityCheck);
+}
+#endif
+
+void ProgramExecutable::unlinkCalls()
+{
+#if ENABLE(JIT)
+    if (!m_jitCodeForCall)
+        return;
+    ASSERT(m_programCodeBlock);
+    m_programCodeBlock->unlinkCalls();
+#endif
+}
+
+void ProgramExecutable::visitChildren(JSCell* cell, SlotVisitor& visitor)
+{
+    ProgramExecutable* thisObject = jsCast<ProgramExecutable*>(cell);
+    ASSERT_GC_OBJECT_INHERITS(thisObject, &s_info);
+    COMPILE_ASSERT(StructureFlags & OverridesVisitChildren, OverridesVisitChildrenWithoutSettingFlag);
+    ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
+    ScriptExecutable::visitChildren(thisObject, visitor);
+    if (thisObject->m_programCodeBlock)
+        thisObject->m_programCodeBlock->visitAggregate(visitor);
+}
+
+void ProgramExecutable::finalize(JSCell* cell)
+{
+    jsCast<ProgramExecutable*>(cell)->clearCode();
+}
+
+inline void ProgramExecutable::clearCode()
+{
+    if (m_programCodeBlock) {
+        m_programCodeBlock->clearEvalCache();
+        m_programCodeBlock.clear();
+    }
+    Base::clearCode();
+}
+
+FunctionCodeBlock* FunctionExecutable::baselineCodeBlockFor(CodeSpecializationKind kind)
+{
+    FunctionCodeBlock* result;
+    if (kind == CodeForCall)
+        result = m_codeBlockForCall.get();
+    else {
+        ASSERT(kind == CodeForConstruct);
+        result = m_codeBlockForConstruct.get();
+    }
+    if (!result)
+        return 0;
+    while (result->alternative())
+        result = static_cast<FunctionCodeBlock*>(result->alternative());
+    ASSERT(result);
+    ASSERT(result->getJITType() == JITCode::BaselineJIT);
+    return result;
+}
+
+JSObject* FunctionExecutable::compileOptimizedForCall(ExecState* exec, ScopeChainNode* scopeChainNode)
+{
+    ASSERT(exec->globalData().dynamicGlobalObject);
+    ASSERT(!!m_codeBlockForCall);
+    JSObject* error = 0;
+    if (m_codeBlockForCall->getJITType() != JITCode::topTierJIT())
+        error = compileForCallInternal(exec, scopeChainNode, JITCode::nextTierJIT(m_codeBlockForCall->getJITType()));
+    ASSERT(!!m_codeBlockForCall);
+    return error;
+}
+
+JSObject* FunctionExecutable::compileOptimizedForConstruct(ExecState* exec, ScopeChainNode* scopeChainNode)
+{
+    ASSERT(exec->globalData().dynamicGlobalObject);
+    ASSERT(!!m_codeBlockForConstruct);
+    JSObject* error = 0;
+    if (m_codeBlockForConstruct->getJITType() != JITCode::topTierJIT())
+        error = compileForConstructInternal(exec, scopeChainNode, JITCode::nextTierJIT(m_codeBlockForConstruct->getJITType()));
+    ASSERT(!!m_codeBlockForConstruct);
+    return error;
+}
+
+FunctionCodeBlock* FunctionExecutable::codeBlockWithBytecodeFor(CodeSpecializationKind kind)
+{
+    FunctionCodeBlock* codeBlock = baselineCodeBlockFor(kind);
+    if (codeBlock->canProduceCopyWithBytecode())
+        return codeBlock;
+    return 0;
+}
+
+PassOwnPtr<FunctionCodeBlock> FunctionExecutable::produceCodeBlockFor(ScopeChainNode* scopeChainNode, CompilationKind compilationKind, CodeSpecializationKind specializationKind, JSObject*& exception)
+{
+    if (!!codeBlockFor(specializationKind) && codeBlockFor(specializationKind)->canProduceCopyWithBytecode()) {
+        BytecodeDestructionBlocker blocker(codeBlockFor(specializationKind).get());
+        return adoptPtr(new FunctionCodeBlock(CodeBlock::CopyParsedBlock, *codeBlockFor(specializationKind)));
+    }
+    
+    exception = 0;
+    JSGlobalData* globalData = scopeChainNode->globalData;
+    JSGlobalObject* globalObject = scopeChainNode->globalObject.get();
+    RefPtr<FunctionBodyNode> body = parse<FunctionBodyNode>(globalData, globalObject, m_source, m_parameters.get(), isStrictMode() ? JSParseStrict : JSParseNormal, FunctionBodyNode::isFunctionNode ? JSParseFunctionCode : JSParseProgramCode, 0, 0, &exception);
+
+    if (!body) {
+        ASSERT(exception);
+        return nullptr;
+    }
+    if (m_forceUsesArguments)
+        body->setUsesArguments();
+    body->finishParsing(m_parameters, m_name);
+    recordParse(body->features(), body->hasCapturedVariables(), body->lineNo(), body->lastLine());
+
+    OwnPtr<FunctionCodeBlock> result;
+    ASSERT((compilationKind == FirstCompilation) == !codeBlockFor(specializationKind));
+    result = adoptPtr(new FunctionCodeBlock(this, FunctionCode, globalObject, source().provider(), source().startOffset(), specializationKind == CodeForConstruct));
+    OwnPtr<BytecodeGenerator> generator(adoptPtr(new BytecodeGenerator(body.get(), scopeChainNode, result->symbolTable(), result.get(), compilationKind)));
+    exception = generator->generate();
+    body->destroyData();
+    if (exception)
+        return nullptr;
+
+    result->copyPostParseDataFrom(codeBlockFor(specializationKind).get());
+    return result.release();
+}
+
+JSObject* FunctionExecutable::compileForCallInternal(ExecState* exec, ScopeChainNode* scopeChainNode, JITCode::JITType jitType)
+{
+    SamplingRegion samplingRegion(jitType == JITCode::BaselineJIT ? "Baseline Compilation (TOTAL)" : "DFG Compilation (TOTAL)");
+    
+#if !ENABLE(JIT)
+    UNUSED_PARAM(exec);
+    UNUSED_PARAM(jitType);
+    UNUSED_PARAM(exec);
+#endif
+    ASSERT((jitType == JITCode::bottomTierJIT()) == !m_codeBlockForCall);
+    JSObject* exception;
+    OwnPtr<FunctionCodeBlock> newCodeBlock = produceCodeBlockFor(scopeChainNode, !!m_codeBlockForCall ? OptimizingCompilation : FirstCompilation, CodeForCall, exception);
+    if (!newCodeBlock)
+        return exception;
+
+    newCodeBlock->setAlternative(static_pointer_cast<CodeBlock>(m_codeBlockForCall.release()));
+    m_codeBlockForCall = newCodeBlock.release();
+    
+    m_numParametersForCall = m_codeBlockForCall->m_numParameters;
+    ASSERT(m_numParametersForCall);
+    m_numCapturedVariables = m_codeBlockForCall->m_numCapturedVars;
+    m_symbolTable = m_codeBlockForCall->sharedSymbolTable();
+
+#if ENABLE(JIT)
+    JSGlobalData* globalData = scopeChainNode->globalData;
+    if (globalData->canUseJIT()) {
+        bool dfgCompiled = false;
+        if (jitType == JITCode::DFGJIT)
+            dfgCompiled = DFG::tryCompileFunction(exec, m_codeBlockForCall.get(), m_jitCodeForCall, m_jitCodeForCallWithArityCheck);
+        if (dfgCompiled) {
+            if (m_codeBlockForCall->alternative())
+                m_codeBlockForCall->alternative()->unlinkIncomingCalls();
+        } else {
+            if (m_codeBlockForCall->alternative()) {
+                m_codeBlockForCall = static_pointer_cast<FunctionCodeBlock>(m_codeBlockForCall->releaseAlternative());
+                m_symbolTable = m_codeBlockForCall->sharedSymbolTable();
+                return 0;
+            }
+            m_jitCodeForCall = JIT::compile(globalData, m_codeBlockForCall.get(), &m_jitCodeForCallWithArityCheck);
+        }
+#if !ENABLE(OPCODE_SAMPLING)
+        if (!BytecodeGenerator::dumpsGeneratedCode())
+            m_codeBlockForCall->handleBytecodeDiscardingOpportunity();
+#endif
+        
+        m_codeBlockForCall->setJITCode(m_jitCodeForCall, m_jitCodeForCallWithArityCheck);
+    }
+#endif
+
+#if ENABLE(JIT)
+#if ENABLE(INTERPRETER)
+    if (!m_jitCodeForCall)
+        Heap::heap(this)->reportExtraMemoryCost(sizeof(*m_codeBlockForCall));
+    else
+#endif
+        Heap::heap(this)->reportExtraMemoryCost(sizeof(*m_codeBlockForCall) + m_jitCodeForCall.size());
+#else
+    Heap::heap(this)->reportExtraMemoryCost(sizeof(*m_codeBlockForCall));
+#endif
+
+    return 0;
+}
+
+JSObject* FunctionExecutable::compileForConstructInternal(ExecState* exec, ScopeChainNode* scopeChainNode, JITCode::JITType jitType)
+{
+    SamplingRegion samplingRegion(jitType == JITCode::BaselineJIT ? "Baseline Compilation (TOTAL)" : "DFG Compilation (TOTAL)");
+    
+#if !ENABLE(JIT)
+    UNUSED_PARAM(jitType);
+    UNUSED_PARAM(exec);
+#endif
+    
+    ASSERT((jitType == JITCode::bottomTierJIT()) == !m_codeBlockForConstruct);
+    JSObject* exception;
+    OwnPtr<FunctionCodeBlock> newCodeBlock = produceCodeBlockFor(scopeChainNode, !!m_codeBlockForConstruct ? OptimizingCompilation : FirstCompilation, CodeForConstruct, exception);
+    if (!newCodeBlock)
+        return exception;
+
+    newCodeBlock->setAlternative(static_pointer_cast<CodeBlock>(m_codeBlockForConstruct.release()));
+    m_codeBlockForConstruct = newCodeBlock.release();
+    
+    m_numParametersForConstruct = m_codeBlockForConstruct->m_numParameters;
+    ASSERT(m_numParametersForConstruct);
+    m_numCapturedVariables = m_codeBlockForConstruct->m_numCapturedVars;
+    m_symbolTable = m_codeBlockForConstruct->sharedSymbolTable();
+
+#if ENABLE(JIT)
+    JSGlobalData* globalData = scopeChainNode->globalData;
+    if (globalData->canUseJIT()) {
+        bool dfgCompiled = false;
+        if (jitType == JITCode::DFGJIT)
+            dfgCompiled = DFG::tryCompileFunction(exec, m_codeBlockForConstruct.get(), m_jitCodeForConstruct, m_jitCodeForConstructWithArityCheck);
+        if (dfgCompiled) {
+            if (m_codeBlockForConstruct->alternative())
+                m_codeBlockForConstruct->alternative()->unlinkIncomingCalls();
+        } else {
+            if (m_codeBlockForConstruct->alternative()) {
+                m_codeBlockForConstruct = static_pointer_cast<FunctionCodeBlock>(m_codeBlockForConstruct->releaseAlternative());
+                m_symbolTable = m_codeBlockForConstruct->sharedSymbolTable();
+                return 0;
+            }
+            m_jitCodeForConstruct = JIT::compile(globalData, m_codeBlockForConstruct.get(), &m_jitCodeForConstructWithArityCheck);
+        }
+#if !ENABLE(OPCODE_SAMPLING)
+        if (!BytecodeGenerator::dumpsGeneratedCode())
+            m_codeBlockForConstruct->handleBytecodeDiscardingOpportunity();
+#endif
+        
+        m_codeBlockForConstruct->setJITCode(m_jitCodeForConstruct, m_jitCodeForConstructWithArityCheck);
+    }
+#endif
+
+#if ENABLE(JIT)
+#if ENABLE(INTERPRETER)
+    if (!m_jitCodeForConstruct)
+        Heap::heap(this)->reportExtraMemoryCost(sizeof(*m_codeBlockForConstruct));
+    else
+#endif
+    Heap::heap(this)->reportExtraMemoryCost(sizeof(*m_codeBlockForConstruct) + m_jitCodeForConstruct.size());
+#else
+    Heap::heap(this)->reportExtraMemoryCost(sizeof(*m_codeBlockForConstruct));
+#endif
+
+    return 0;
+}
+
+#if ENABLE(JIT)
+void FunctionExecutable::jettisonOptimizedCodeForCall(JSGlobalData& globalData)
+{
+    jettisonCodeBlock(globalData, m_codeBlockForCall);
+    m_jitCodeForCall = m_codeBlockForCall->getJITCode();
+    m_jitCodeForCallWithArityCheck = m_codeBlockForCall->getJITCodeWithArityCheck();
+}
+
+void FunctionExecutable::jettisonOptimizedCodeForConstruct(JSGlobalData& globalData)
+{
+    jettisonCodeBlock(globalData, m_codeBlockForConstruct);
+    m_jitCodeForConstruct = m_codeBlockForConstruct->getJITCode();
+    m_jitCodeForConstructWithArityCheck = m_codeBlockForConstruct->getJITCodeWithArityCheck();
+}
+#endif
+
+void FunctionExecutable::visitChildren(JSCell* cell, SlotVisitor& visitor)
+{
+    FunctionExecutable* thisObject = jsCast<FunctionExecutable*>(cell);
+    ASSERT_GC_OBJECT_INHERITS(thisObject, &s_info);
+    COMPILE_ASSERT(StructureFlags & OverridesVisitChildren, OverridesVisitChildrenWithoutSettingFlag);
+    ASSERT(thisObject->structure()->typeInfo().overridesVisitChildren());
+    ScriptExecutable::visitChildren(thisObject, visitor);
+    if (thisObject->m_nameValue)
+        visitor.append(&thisObject->m_nameValue);
+    if (thisObject->m_codeBlockForCall)
+        thisObject->m_codeBlockForCall->visitAggregate(visitor);
+    if (thisObject->m_codeBlockForConstruct)
+        thisObject->m_codeBlockForConstruct->visitAggregate(visitor);
+}
+
+void FunctionExecutable::discardCode()
+{
+#if ENABLE(JIT)
+    // These first two checks are to handle the rare case where
+    // we are trying to evict code for a function during its
+    // codegen.
+    if (!m_jitCodeForCall && m_codeBlockForCall)
+        return;
+    if (!m_jitCodeForConstruct && m_codeBlockForConstruct)
+        return;
+#endif
+    clearCode();
+}
+
+void FunctionExecutable::finalize(JSCell* cell)
+{
+    jsCast<FunctionExecutable*>(cell)->clearCode();
+}
+
+inline void FunctionExecutable::clearCode()
+{
+    if (m_codeBlockForCall) {
+        m_codeBlockForCall->clearEvalCache();
+        m_codeBlockForCall.clear();
+    }
+    if (m_codeBlockForConstruct) {
+        m_codeBlockForConstruct->clearEvalCache();
+        m_codeBlockForConstruct.clear();
+    }
+    Base::clearCode();
+}
+
+void FunctionExecutable::unlinkCalls()
+{
+#if ENABLE(JIT)
+    if (!!m_jitCodeForCall) {
+        ASSERT(m_codeBlockForCall);
+        m_codeBlockForCall->unlinkCalls();
+    }
+    if (!!m_jitCodeForConstruct) {
+        ASSERT(m_codeBlockForConstruct);
+        m_codeBlockForConstruct->unlinkCalls();
+    }
+#endif
+}
+
+FunctionExecutable* FunctionExecutable::fromGlobalCode(const Identifier& functionName, ExecState* exec, Debugger* debugger, const SourceCode& source, JSObject** exception)
+{
+    JSGlobalObject* lexicalGlobalObject = exec->lexicalGlobalObject();
+    RefPtr<ProgramNode> program = parse<ProgramNode>(&exec->globalData(), lexicalGlobalObject, source, 0, JSParseNormal, ProgramNode::isFunctionNode ? JSParseFunctionCode : JSParseProgramCode, debugger, exec, exception);
+    if (!program) {
+        ASSERT(*exception);
+        return 0;
+    }
+
+    // Uses of this function that would not result in a single function expression are invalid.
+    StatementNode* exprStatement = program->singleStatement();
+    ASSERT(exprStatement);
+    ASSERT(exprStatement->isExprStatement());
+    ExpressionNode* funcExpr = static_cast<ExprStatementNode*>(exprStatement)->expr();
+    ASSERT(funcExpr);
+    ASSERT(funcExpr->isFuncExprNode());
+    FunctionBodyNode* body = static_cast<FuncExprNode*>(funcExpr)->body();
+    ASSERT(body);
+
+    return FunctionExecutable::create(exec->globalData(), functionName, body->source(), body->usesArguments(), body->parameters(), body->isStrictMode(), body->lineNo(), body->lastLine());
+}
+
+UString FunctionExecutable::paramString() const
+{
+    FunctionParameters& parameters = *m_parameters;
+    UStringBuilder builder;
+    for (size_t pos = 0; pos < parameters.size(); ++pos) {
+        if (!builder.isEmpty())
+            builder.append(", ");
+        builder.append(parameters[pos].ustring());
+    }
+    return builder.toUString();
+}
+
+}