Source/JavaScriptCore/interpreter/CallFrame.cpp

/*
 * Copyright (C) 2008, 2013, 2014 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 "CallFrame.h"

#include "CodeBlock.h"
#include "InlineCallFrame.h"
#include "Interpreter.h"
#include "JSLexicalEnvironment.h"
#include "JSCInlines.h"
#include "VMEntryScope.h"
#include <wtf/StringPrintStream.h>

namespace JSC {

bool CallFrame::callSiteBitsAreBytecodeOffset() const
{
    ASSERT(codeBlock());
    switch (codeBlock()->jitType()) {
    case JITCode::InterpreterThunk:
    case JITCode::BaselineJIT:
        return true;
    case JITCode::None:
    case JITCode::HostCallThunk:
        RELEASE_ASSERT_NOT_REACHED();
        return false;
    default:
        return false;
    }

    RELEASE_ASSERT_NOT_REACHED();
    return false;
}

bool CallFrame::callSiteBitsAreCodeOriginIndex() const
{
    ASSERT(codeBlock());
    switch (codeBlock()->jitType()) {
    case JITCode::DFGJIT:
    case JITCode::FTLJIT:
        return true;
    case JITCode::None:
    case JITCode::HostCallThunk:
        RELEASE_ASSERT_NOT_REACHED();
        return false;
    default:
        return false;
    }

    RELEASE_ASSERT_NOT_REACHED();
    return false;
}

unsigned CallFrame::callSiteAsRawBits() const
{
    return this[JSStack::ArgumentCount].tag();
}

CallSiteIndex CallFrame::callSiteIndex() const
{
    return CallSiteIndex(callSiteAsRawBits());
}

bool CallFrame::hasActivation() const
{
    JSValue activation = uncheckedActivation();
    return !!activation && activation.isCell();
}

JSValue CallFrame::uncheckedActivation() const
{
    CodeBlock* codeBlock = this->codeBlock();
    RELEASE_ASSERT(codeBlock->needsActivation());
    VirtualRegister activationRegister = codeBlock->activationRegister();
    return registers()[activationRegister.offset()].jsValue();
}

#ifndef NDEBUG
JSStack* CallFrame::stack()
{
    return &interpreter()->stack();
}

#endif

#if USE(JSVALUE32_64)
Instruction* CallFrame::currentVPC() const
{
    return bitwise_cast<Instruction*>(callSiteIndex().bits());
}

void CallFrame::setCurrentVPC(Instruction* vpc)
{
    CallSiteIndex callSite(vpc);
    this[JSStack::ArgumentCount].tag() = callSite.bits();
}

unsigned CallFrame::callSiteBitsAsBytecodeOffset() const
{
    ASSERT(codeBlock());
    ASSERT(callSiteBitsAreBytecodeOffset());
    return currentVPC() - codeBlock()->instructions().begin();     
}

#else // USE(JSVALUE32_64)
Instruction* CallFrame::currentVPC() const
{
    ASSERT(callSiteBitsAreBytecodeOffset());
    return codeBlock()->instructions().begin() + callSiteBitsAsBytecodeOffset();
}

void CallFrame::setCurrentVPC(Instruction* vpc)
{
    CallSiteIndex callSite(vpc - codeBlock()->instructions().begin());
    this[JSStack::ArgumentCount].tag() = static_cast<int32_t>(callSite.bits());
}

unsigned CallFrame::callSiteBitsAsBytecodeOffset() const
{
    ASSERT(codeBlock());
    ASSERT(callSiteBitsAreBytecodeOffset());
    return callSiteIndex().bits();
}

#endif
    
unsigned CallFrame::bytecodeOffset()
{
    if (!codeBlock())
        return 0;
#if ENABLE(DFG_JIT)
    if (callSiteBitsAreCodeOriginIndex()) {
        ASSERT(codeBlock());
        CodeOrigin codeOrigin = this->codeOrigin();
        for (InlineCallFrame* inlineCallFrame = codeOrigin.inlineCallFrame; inlineCallFrame;) {
            codeOrigin = inlineCallFrame->directCaller;
            inlineCallFrame = codeOrigin.inlineCallFrame;
        }
        return codeOrigin.bytecodeIndex;
    }
#endif
    ASSERT(callSiteBitsAreBytecodeOffset());
    return callSiteBitsAsBytecodeOffset();
}

CodeOrigin CallFrame::codeOrigin()
{
    if (!codeBlock())
        return CodeOrigin(0);
#if ENABLE(DFG_JIT)
    if (callSiteBitsAreCodeOriginIndex()) {
        CallSiteIndex index = callSiteIndex();
        ASSERT(codeBlock()->canGetCodeOrigin(index));
        return codeBlock()->codeOrigin(index);
    }
#endif
    return CodeOrigin(callSiteBitsAsBytecodeOffset());
}

Register* CallFrame::topOfFrameInternal()
{
    CodeBlock* codeBlock = this->codeBlock();
    ASSERT(codeBlock);
    return registers() + codeBlock->stackPointerOffset();
}

JSGlobalObject* CallFrame::vmEntryGlobalObject()
{
    if (this == lexicalGlobalObject()->globalExec())
        return lexicalGlobalObject();

    // For any ExecState that's not a globalExec, the 
    // dynamic global object must be set since code is running
    ASSERT(vm().entryScope);
    return vm().entryScope->globalObject();
}

CallFrame* CallFrame::callerFrame(VMEntryFrame*& currVMEntryFrame)
{
    if (callerFrameOrVMEntryFrame() == currVMEntryFrame) {
        VMEntryRecord* currVMEntryRecord = vmEntryRecord(currVMEntryFrame);
        currVMEntryFrame = currVMEntryRecord->prevTopVMEntryFrame();
        return currVMEntryRecord->prevTopCallFrame();
    }
    return static_cast<CallFrame*>(callerFrameOrVMEntryFrame());
}

JSLexicalEnvironment* CallFrame::lexicalEnvironment() const
{
    CodeBlock* codeBlock = this->codeBlock();
    RELEASE_ASSERT(codeBlock->needsActivation());
    VirtualRegister activationRegister = codeBlock->activationRegister();
    return registers()[activationRegister.offset()].Register::lexicalEnvironment();
}

JSLexicalEnvironment* CallFrame::lexicalEnvironmentOrNullptr() const
{
    CodeBlock* codeBlock = this->codeBlock();
    return codeBlock->needsActivation() ? lexicalEnvironment() : nullptr;
}
    
void CallFrame::setActivation(JSLexicalEnvironment* lexicalEnvironment)
{
    CodeBlock* codeBlock = this->codeBlock();
    RELEASE_ASSERT(codeBlock->needsActivation());
    VirtualRegister activationRegister = codeBlock->activationRegister();
    registers()[activationRegister.offset()] = lexicalEnvironment;
}

void CallFrame::dump(PrintStream& out)
{
    if (CodeBlock* codeBlock = this->codeBlock()) {
        out.print(codeBlock->inferredName(), "#", codeBlock->hashAsStringIfPossible(), " [", codeBlock->jitType(), "]");

        out.print("(");
        thisValue().dumpForBacktrace(out);

        for (size_t i = 0; i < argumentCount(); ++i) {
            out.print(", ");
            JSValue value = argument(i);
            value.dumpForBacktrace(out);
        }

        out.print(")");

        return;
    }

    out.print(returnPC());
}

const char* CallFrame::describeFrame()
{
    const size_t bufferSize = 200;
    static char buffer[bufferSize + 1];
    
    WTF::StringPrintStream stringStream;

    dump(stringStream);

    strncpy(buffer, stringStream.toCString().data(), bufferSize);
    buffer[bufferSize] = '\0';
    
    return buffer;
}

} // namespace JSC