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#include "debugging.h"
#include "qmljs_objects.h"

#include <iostream>

#define LOW_LEVEL_DEBUGGING_HELPERS

using namespace QQmlJS;
using namespace QQmlJS::Debugging;

FunctionState::FunctionState(VM::ExecutionContext *context)
    : _context(context)
{
    if (debugger())
        debugger()->enterFunction(this);
}

FunctionState::~FunctionState()
{
    if (debugger())
        debugger()->leaveFunction(this);
}

VM::Value *FunctionState::argument(unsigned idx)
{
    if (idx < _context->argumentCount)
        return _context->arguments + idx;
    else
        return 0;
}

VM::Value *FunctionState::local(unsigned idx)
{
    if (idx < _context->variableCount())
        return _context->locals + idx;
    return 0;
}

#ifdef LOW_LEVEL_DEBUGGING_HELPERS
Debugger *globalInstance = 0;

void printStackTrace()
{
    if (globalInstance)
        globalInstance->printStackTrace();
    else
        std::cerr << "No debugger." << std::endl;
}
#endif // DO_TRACE_INSTR

Debugger::Debugger(VM::ExecutionEngine *engine)
    : _engine(engine)
{
#ifdef LOW_LEVEL_DEBUGGING_HELPERS
    globalInstance = this;
#endif // DO_TRACE_INSTR
}

Debugger::~Debugger()
{
#ifdef LOW_LEVEL_DEBUGGING_HELPERS
    globalInstance = 0;
#endif // DO_TRACE_INSTR

    qDeleteAll(_functionInfo.values());
}

void Debugger::addFunction(IR::Function *function)
{
    _functionInfo.insert(function, new FunctionDebugInfo(function));
}

void Debugger::setSourceLocation(IR::Function *function, unsigned line, unsigned column)
{
    _functionInfo[function]->setSourceLocation(line, column);
}

void Debugger::mapFunction(VM::Function *vmf, IR::Function *irf)
{
    _vmToIr.insert(vmf, irf);
}

FunctionDebugInfo *Debugger::debugInfo(VM::FunctionObject *function) const
{
    if (!function)
        return 0;

    if (VM::ScriptFunction *sf = function->asScriptFunction())
        return _functionInfo[irFunction(sf->function)];
    else
        return 0;
}

QString Debugger::name(VM::FunctionObject *function) const
{
    if (FunctionDebugInfo *i = debugInfo(function))
        return i->name;

    return QString();
}

void Debugger::aboutToCall(VM::FunctionObject *function, VM::ExecutionContext *context)
{
    _callStack.append(CallInfo(context, function));
}

void Debugger::justLeft(VM::ExecutionContext *context)
{
    int idx = callIndex(context);
    if (idx < 0)
        qDebug() << "Oops, leaving a function that was not registered...?";
    else
        _callStack.resize(idx);
}

void Debugger::enterFunction(FunctionState *state)
{
    _callStack[callIndex(state->context())].state = state;

#ifdef DO_TRACE_INSTR
    QString n = name(_callStack[callIndex(state->context())].function);
    std::cerr << "*** Entering \"" << qPrintable(n) << "\" with " << state->context()->argumentCount << " args" << std::endl;
//    for (unsigned i = 0; i < state->context()->variableEnvironment->argumentCount; ++i)
//        std::cerr << "        " << i << ": " << currentArg(i) << std::endl;
#endif // DO_TRACE_INSTR
}

void Debugger::leaveFunction(FunctionState *state)
{
    _callStack[callIndex(state->context())].state = 0;
}

void Debugger::aboutToThrow(VM::Value *value)
{
    qDebug() << "*** We are about to throw...:" << value->toString(currentState()->context())->toQString();
}

FunctionState *Debugger::currentState() const
{
    if (_callStack.isEmpty())
        return 0;
    else
        return _callStack.last().state;
}

const char *Debugger::currentArg(unsigned idx) const
{
    FunctionState *state = currentState();
    return qPrintable(state->argument(idx)->toString(state->context())->toQString());
}

const char *Debugger::currentLocal(unsigned idx) const
{
    FunctionState *state = currentState();
    return qPrintable(state->local(idx)->toString(state->context())->toQString());
}

const char *Debugger::currentTemp(unsigned idx) const
{
    FunctionState *state = currentState();
    return qPrintable(state->temp(idx)->toString(state->context())->toQString());
}

void Debugger::printStackTrace() const
{
    for (int i = _callStack.size() - 1; i >=0; --i) {
        QString n = name(_callStack[i].function);
        std::cerr << "\tframe #" << i << ": " << qPrintable(n) << std::endl;
    }
}

int Debugger::callIndex(VM::ExecutionContext *context)
{
    for (int idx = _callStack.size() - 1; idx >= 0; --idx) {
        if (_callStack[idx].context == context)
            return idx;
    }

    return -1;
}

IR::Function *Debugger::irFunction(VM::Function *vmf) const
{
    return _vmToIr[vmf];
}