gdbengine.cpp

/**************************************************************************
**
** This file is part of Qt Creator
**
** Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).
**
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** Commercial Usage
**
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
** GNU Lesser General Public License Usage
**
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at http://qt.nokia.com/contact.
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#define QT_NO_CAST_FROM_ASCII

#include "gdbengine.h"
#include "gdboptionspage.h"
#include "trkoptions.h"
#include "trkoptionspage.h"

#include "attachgdbadapter.h"
#include "coregdbadapter.h"
#include "plaingdbadapter.h"
#include "termgdbadapter.h"
#include "remotegdbadapter.h"
#include "trkgdbadapter.h"

#include "watchutils.h"
#include "debuggeractions.h"
#include "debuggeragents.h"
#include "debuggerconstants.h"
#include "debuggermanager.h"
#include "debuggertooltip.h"
#include "debuggerstringutils.h"
#include "gdbmi.h"

#include "breakhandler.h"
#include "moduleshandler.h"
#include "registerhandler.h"
#include "stackhandler.h"
#include "watchhandler.h"
#include "sourcefileswindow.h"

#include "debuggerdialogs.h"

#include <utils/qtcassert.h>
#include <utils/fancymainwindow.h>
#include <texteditor/itexteditor.h>
#include <projectexplorer/toolchain.h>
#include <coreplugin/icore.h>

#include <QtCore/QDebug>
#include <QtCore/QDir>
#include <QtCore/QFileInfo>
#include <QtCore/QMetaObject>
#include <QtCore/QTime>
#include <QtCore/QTimer>
#include <QtCore/QTextStream>

#include <QtGui/QAction>
#include <QtCore/QCoreApplication>
#include <QtGui/QLabel>
#include <QtGui/QMainWindow>
#include <QtGui/QMessageBox>
#include <QtGui/QDialogButtonBox>
#include <QtGui/QPushButton>
#ifdef Q_OS_WIN
#    include "shared/sharedlibraryinjector.h"
#endif

#ifdef Q_OS_UNIX
#include <unistd.h>
#include <dlfcn.h>
#endif
#include <ctype.h>

namespace Debugger {
namespace Internal {

//#define DEBUG_PENDING  1
//#define DEBUG_SUBITEM  1

#if DEBUG_PENDING
#   define PENDING_DEBUG(s) qDebug() << s
#else
#   define PENDING_DEBUG(s)
#endif
#define PENDING_DEBUGX(s) qDebug() << s

#define CB(callback) &GdbEngine::callback, STRINGIFY(callback)

static bool stateAcceptsGdbCommands(DebuggerState state)
{
    switch (state) {
    case AdapterStarting:
    case AdapterStarted:
    case AdapterStartFailed:
    case InferiorUnrunnable:
    case InferiorStarting:
    case InferiorStartFailed:
    case InferiorRunningRequested:
    case InferiorRunningRequested_Kill:
    case InferiorRunning:
    case InferiorStopping:
    case InferiorStopping_Kill:
    case InferiorStopped:
    case InferiorShuttingDown:
    case InferiorShutDown:
    case InferiorShutdownFailed:
        return true;
    case DebuggerNotReady:
    case EngineStarting:
    case InferiorStopFailed:
    case EngineShuttingDown:
        break;
    }
    return false;
}

static int &currentToken()
{
    static int token = 0;
    return token;
}

// reads a MI-encoded item frome the consolestream
static bool parseConsoleStream(const GdbResponse &response, GdbMi *contents)
{
    GdbMi output = response.data.findChild("consolestreamoutput");
    QByteArray out = output.data();

    int markerPos = out.indexOf('"') + 1; // position of 'success marker'
    if (markerPos == 0 || out.at(markerPos) == 'f') {  // 't' or 'f'
        // custom dumper produced no output
        return false;
    }

    out = out.mid(markerPos +  1);
    out = out.left(out.lastIndexOf('"'));
    // optimization: dumper output never needs real C unquoting
    out.replace('\\', "");
    out = "dummy={" + out + "}";

    contents->fromString(out);
    //qDebug() << "CONTENTS" << contents->toString(true);
    return contents->isValid();
}

static QByteArray parsePlainConsoleStream(const GdbResponse &response)
{
    GdbMi output = response.data.findChild("consolestreamoutput");
    QByteArray out = output.data();
    // FIXME: proper decoding needed
    if (out.endsWith("\\n"))
        out.chop(2);
    while (out.endsWith('\n') || out.endsWith(' '))
        out.chop(1);
    int pos = out.indexOf(" = ");
    return out.mid(pos + 3);
}

///////////////////////////////////////////////////////////////////////
//
// GdbEngine
//
///////////////////////////////////////////////////////////////////////

GdbEngine::GdbEngine(DebuggerManager *manager) :
    IDebuggerEngine(manager),
#ifdef Q_OS_WIN // Do injection loading with MinGW (call loading does not work with 64bit)
    m_dumperInjectionLoad(true)
#else
    m_dumperInjectionLoad(false)
#endif
{
    m_trkOptions = QSharedPointer<TrkOptions>(new TrkOptions);
    m_trkOptions->fromSettings(Core::ICore::instance()->settings());
    m_gdbAdapter = 0;

    m_commandTimer = new QTimer(this);
    m_commandTimer->setSingleShot(true);
    m_commandTimer->setInterval(COMMAND_TIMEOUT);
    connect(m_commandTimer, SIGNAL(timeout()), SLOT(commandTimeout()));

    // Needs no resetting in initializeVariables()
    m_busy = false;

    connect(theDebuggerAction(AutoDerefPointers), SIGNAL(valueChanged(QVariant)),
            this, SLOT(setAutoDerefPointers(QVariant)));
}

void GdbEngine::connectDebuggingHelperActions()
{
    connect(theDebuggerAction(UseDebuggingHelpers), SIGNAL(valueChanged(QVariant)),
            this, SLOT(setUseDebuggingHelpers(QVariant)));
    connect(theDebuggerAction(DebugDebuggingHelpers), SIGNAL(valueChanged(QVariant)),
            this, SLOT(setDebugDebuggingHelpers(QVariant)));
    connect(theDebuggerAction(RecheckDebuggingHelpers), SIGNAL(triggered()),
            this, SLOT(recheckDebuggingHelperAvailability()));
}
   
void GdbEngine::disconnectDebuggingHelperActions()
{
    disconnect(theDebuggerAction(UseDebuggingHelpers), 0, this, 0);
    disconnect(theDebuggerAction(DebugDebuggingHelpers), 0, this, 0);
    disconnect(theDebuggerAction(RecheckDebuggingHelpers), 0, this, 0);
}

DebuggerStartMode GdbEngine::startMode() const
{
    QTC_ASSERT(!m_startParameters.isNull(), return NoStartMode);
    return m_startParameters->startMode;
}

QMainWindow *GdbEngine::mainWindow() const
{
    return m_manager->mainWindow();
}

GdbEngine::~GdbEngine()
{
    // prevent sending error messages afterwards
    disconnect(&m_gdbProc, 0, this, 0);
    delete m_gdbAdapter;
    m_gdbAdapter = 0;
}

void GdbEngine::connectAdapter()
{
    connect(m_gdbAdapter, SIGNAL(adapterStarted()),
        this, SLOT(handleAdapterStarted()));
    connect(m_gdbAdapter, SIGNAL(adapterStartFailed(QString,QString)),
        this, SLOT(handleAdapterStartFailed(QString,QString)));

    connect(m_gdbAdapter, SIGNAL(inferiorPrepared()),
        this, SLOT(handleInferiorPrepared()));

    connect(m_gdbAdapter, SIGNAL(inferiorStartFailed(QString)),
        this, SLOT(handleInferiorStartFailed(QString)));

    connect(m_gdbAdapter, SIGNAL(adapterCrashed(QString)),
        this, SLOT(handleAdapterCrashed(QString)));
}

void GdbEngine::initializeVariables()
{
    m_debuggingHelperState = DebuggingHelperUninitialized;
    m_gdbVersion = 100;
    m_gdbBuildVersion = -1;
    m_isMacGdb = false;
    m_isSynchroneous = false;
    m_registerNamesListed = false;

    m_fullToShortName.clear();
    m_shortToFullName.clear();
    m_varToType.clear();

    m_modulesListOutdated = m_sourcesListOutdated = true;
    m_sourcesListUpdating = false;
    m_oldestAcceptableToken = -1;
    m_outputCodec = QTextCodec::codecForLocale();
    m_pendingRequests = 0;
    m_commandsDoneCallback = 0;
    m_commandsToRunOnTemporaryBreak.clear();
    m_cookieForToken.clear();

    m_pendingConsoleStreamOutput.clear();
    m_pendingLogStreamOutput.clear();

    m_inbuffer.clear();

    // ConverterState has no reset() function.
    m_outputCodecState.~ConverterState();
    new (&m_outputCodecState) QTextCodec::ConverterState();

    m_currentFunctionArgs.clear();
    m_currentFrame.clear();
    m_dumperHelper.clear();
#ifdef Q_OS_LINUX
    m_entryPoint.clear();
#endif
}

QString GdbEngine::errorMessage(QProcess::ProcessError error)
{
    switch (error) {
        case QProcess::FailedToStart:
            return tr("The Gdb process failed to start. Either the "
                "invoked program '%1' is missing, or you may have insufficient "
                "permissions to invoke the program.")
                .arg(theDebuggerStringSetting(GdbLocation));
        case QProcess::Crashed:
            return tr("The Gdb process crashed some time after starting "
                "successfully.");
        case QProcess::Timedout:
            return tr("The last waitFor...() function timed out. "
                "The state of QProcess is unchanged, and you can try calling "
                "waitFor...() again.");
        case QProcess::WriteError:
            return tr("An error occurred when attempting to write "
                "to the Gdb process. For example, the process may not be running, "
                "or it may have closed its input channel.");
        case QProcess::ReadError:
            return tr("An error occurred when attempting to read from "
                "the Gdb process. For example, the process may not be running.");
        default:
            return tr("An unknown error in the Gdb process occurred. ");
    }
}

#if 0
static void dump(const char *first, const char *middle, const QString & to)
{
    QByteArray ba(first, middle - first);
    Q_UNUSED(to)
    // note that qDebug cuts off output after a certain size... (bug?)
    qDebug("\n>>>>> %s\n%s\n====\n%s\n<<<<<\n",
        qPrintable(currentTime()),
        qPrintable(QString(ba).trimmed()),
        qPrintable(to.trimmed()));
    //qDebug() << "";
    //qDebug() << qPrintable(currentTime())
    //    << " Reading response:  " << QString(ba).trimmed() << "\n";
}
#endif

void GdbEngine::readDebugeeOutput(const QByteArray &data)
{
    m_manager->showApplicationOutput(m_outputCodec->toUnicode(
            data.constData(), data.length(), &m_outputCodecState));
}

void GdbEngine::debugMessage(const QString &msg)
{
    gdbOutputAvailable(LogDebug, msg);
}

void GdbEngine::handleResponse(const QByteArray &buff)
{
    static QTime lastTime;

    if (theDebuggerBoolSetting(LogTimeStamps))
        gdbOutputAvailable(LogTime, currentTime());
    gdbOutputAvailable(LogOutput, QString::fromLocal8Bit(buff, buff.length()));

#if 0
    qDebug() // << "#### start response handling #### "
        << currentTime()
        << lastTime.msecsTo(QTime::currentTime()) << "ms,"
        << "buf:" << buff.left(1500) << "..."
        //<< "buf:" << buff
        << "size:" << buff.size();
#else
    //qDebug() << "buf:" << buff;
#endif

    lastTime = QTime::currentTime();

    if (buff.isEmpty() || buff == "(gdb) ")
        return;

    const char *from = buff.constData();
    const char *to = from + buff.size();
    const char *inner;

    int token = -1;
    // token is a sequence of numbers
    for (inner = from; inner != to; ++inner)
        if (*inner < '0' || *inner > '9')
            break;
    if (from != inner) {
        token = QByteArray(from, inner - from).toInt();
        from = inner;
        //qDebug() << "found token" << token;
    }

    // next char decides kind of response
    const char c = *from++;
    //qDebug() << "CODE:" << c;
    switch (c) {
        case '*':
        case '+':
        case '=': {
            QByteArray asyncClass;
            for (; from != to; ++from) {
                const char c = *from;
                if (!isNameChar(c))
                    break;
                asyncClass += *from;
            }
            //qDebug() << "ASYNCCLASS" << asyncClass;

            GdbMi result;
            while (from != to) {
                GdbMi data;
                if (*from != ',') {
                    // happens on archer where we get 
                    // 23^running <NL> *running,thread-id="all" <NL> (gdb) 
                    result.m_type = GdbMi::Tuple;
                    break;
                }
                ++from; // skip ','
                data.parseResultOrValue(from, to);
                if (data.isValid()) {
                    //qDebug() << "parsed result:" << data.toString();
                    result.m_children += data;
                    result.m_type = GdbMi::Tuple;
                }
            }
            if (asyncClass == "stopped") {
                handleStopResponse(result);
            } else if (asyncClass == "running") {
                // Archer has 'thread-id="all"' here
            } else if (asyncClass == "library-loaded") {
                // Archer has 'id="/usr/lib/libdrm.so.2",
                // target-name="/usr/lib/libdrm.so.2",
                // host-name="/usr/lib/libdrm.so.2",
                // symbols-loaded="0"
                QByteArray id = result.findChild("id").data();
                if (!id.isEmpty())
                    showStatusMessage(tr("Library %1 loaded.").arg(_(id)));
                m_modulesListOutdated = m_sourcesListOutdated = true;
            } else if (asyncClass == "library-unloaded") {
                // Archer has 'id="/usr/lib/libdrm.so.2",
                // target-name="/usr/lib/libdrm.so.2",
                // host-name="/usr/lib/libdrm.so.2"
                QByteArray id = result.findChild("id").data();
                showStatusMessage(tr("Library %1 unloaded.").arg(_(id)));
                m_modulesListOutdated = m_sourcesListOutdated = true;
            } else if (asyncClass == "thread-group-created") {
                // Archer has "{id="28902"}" 
                QByteArray id = result.findChild("id").data();
                showStatusMessage(tr("Thread group %1 created.").arg(_(id)));
                int pid = id.toInt();
                if (pid != inferiorPid())
                    handleInferiorPidChanged(pid);
            } else if (asyncClass == "thread-created") {
                //"{id="1",group-id="28902"}" 
                QByteArray id = result.findChild("id").data();
                showStatusMessage(tr("Thread %1 created.").arg(_(id)));
            } else if (asyncClass == "thread-group-exited") {
                // Archer has "{id="28902"}" 
                QByteArray id = result.findChild("id").data();
                showStatusMessage(tr("Thread group %1 exited.").arg(_(id)));
            } else if (asyncClass == "thread-exited") {
                //"{id="1",group-id="28902"}" 
                QByteArray id = result.findChild("id").data();
                QByteArray groupid = result.findChild("group-id").data();
                showStatusMessage(tr("Thread %1 in group %2 exited.")
                    .arg(_(id)).arg(_(groupid)));
            } else if (asyncClass == "thread-selected") {
                QByteArray id = result.findChild("id").data();
                showStatusMessage(tr("Thread %1 selected.").arg(_(id)));
                //"{id="2"}" 
            #if defined(Q_OS_MAC)
            } else if (asyncClass == "shlibs-updated") {
                // MAC announces updated libs
                m_modulesListOutdated = m_sourcesListOutdated = true;
            } else if (asyncClass == "shlibs-added") {
                // MAC announces added libs
                // {shlib-info={num="2", name="libmathCommon.A_debug.dylib",
                // kind="-", dyld-addr="0x7f000", reason="dyld", requested-state="Y",
                // state="Y", path="/usr/lib/system/libmathCommon.A_debug.dylib",
                // description="/usr/lib/system/libmathCommon.A_debug.dylib",
                // loaded_addr="0x7f000", slide="0x7f000", prefix=""}}
                m_modulesListOutdated = m_sourcesListOutdated = true;
            #endif
            } else {
                qDebug() << "IGNORED ASYNC OUTPUT"
                    << asyncClass << result.toString();
            }
            break;
        }

        case '~': {
            QByteArray data = GdbMi::parseCString(from, to);
            m_pendingConsoleStreamOutput += data;

            // Parse pid from noise.
            if (!inferiorPid()) {
                // Linux/Mac gdb: [New [Tt]hread 0x545 (LWP 4554)]
                static QRegExp re1(_("New .hread 0x[0-9a-f]+ \\(LWP ([0-9]*)\\)"));
                // MinGW 6.8: [New thread 2437.0x435345]
                static QRegExp re2(_("New .hread ([0-9]+)\\.0x[0-9a-f]*"));
                // Mac: [Switching to process 9294 local thread 0x2e03] or
                // [Switching to process 31773]
                static QRegExp re3(_("Switching to process ([0-9]+)"));
                QTC_ASSERT(re1.isValid() && re2.isValid(), return);
                if (re1.indexIn(_(data)) != -1)
                    maybeHandleInferiorPidChanged(re1.cap(1));
                else if (re2.indexIn(_(data)) != -1)
                    maybeHandleInferiorPidChanged(re2.cap(1));
                else if (re3.indexIn(_(data)) != -1)
                    maybeHandleInferiorPidChanged(re3.cap(1));
            }

            // Show some messages to give the impression something happens.
            if (data.startsWith("Reading symbols from ")) {
                showStatusMessage(tr("Reading %1...").arg(_(data.mid(21))), 1000);
                m_modulesListOutdated = m_sourcesListOutdated = true;
            } else if (data.startsWith("[New ") || data.startsWith("[Thread ")) {
                if (data.endsWith('\n'))
                    data.chop(1);
                showStatusMessage(_(data), 1000);
            }
            break;
        }

        case '@': {
            readDebugeeOutput(GdbMi::parseCString(from, to));
            break;
        }

        case '&': {
            QByteArray data = GdbMi::parseCString(from, to);
            m_pendingLogStreamOutput += data;
            // On Windows, the contents seem to depend on the debugger
            // version and/or OS version used.
            if (data.startsWith("warning:"))
                manager()->showApplicationOutput(_(data.mid(9))); // cut "warning: "
            break;
        }

        case '^': {
            GdbResponse response;

            response.token = token;

            for (inner = from; inner != to; ++inner)
                if (*inner < 'a' || *inner > 'z')
                    break;

            QByteArray resultClass = QByteArray::fromRawData(from, inner - from);
            if (resultClass == "done") {
                response.resultClass = GdbResultDone;
            } else if (resultClass == "running") {
                if (state() == InferiorStopped) { // Result of manual command.
                    m_manager->resetLocation();
                    setTokenBarrier();
                    setState(InferiorRunningRequested);
                }
                setState(InferiorRunning);
                showStatusMessage(tr("Running..."));
                response.resultClass = GdbResultRunning;
            } else if (resultClass == "connected") {
                response.resultClass = GdbResultConnected;
            } else if (resultClass == "error") {
                response.resultClass = GdbResultError;
            } else if (resultClass == "exit") {
                response.resultClass = GdbResultExit;
            } else {
                response.resultClass = GdbResultUnknown;
            }

            from = inner;
            if (from != to) {
                if (*from == ',') {
                    ++from;
                    response.data.parseTuple_helper(from, to);
                    response.data.m_type = GdbMi::Tuple;
                    response.data.m_name = "data";
                } else {
                    // Archer has this
                    response.data.m_type = GdbMi::Tuple;
                    response.data.m_name = "data";
                }
            }

            //qDebug() << "\nLOG STREAM:" + m_pendingLogStreamOutput;
            //qDebug() << "\nCONSOLE STREAM:" + m_pendingConsoleStreamOutput;
            response.data.setStreamOutput("logstreamoutput",
                m_pendingLogStreamOutput);
            response.data.setStreamOutput("consolestreamoutput",
                m_pendingConsoleStreamOutput);
            m_pendingLogStreamOutput.clear();
            m_pendingConsoleStreamOutput.clear();

            handleResultRecord(&response);
            break;
        }
        default: {
            qDebug() << "UNKNOWN RESPONSE TYPE" << c;
            break;
        }
    }
}

void GdbEngine::readGdbStandardError()
{
    QByteArray err = m_gdbProc.readAllStandardError();
    if (err == "Undefined command: \"bb\".  Try \"help\".\n")
        return;
    qWarning() << "Unexpected gdb stderr:" << err;
}

void GdbEngine::readGdbStandardOutput()
{
    if (m_commandTimer->isActive())
        m_commandTimer->start(); // Retrigger

    int newstart = 0;
    int scan = m_inbuffer.size();

    m_inbuffer.append(m_gdbProc.readAllStandardOutput());

    // This can trigger when a dialog starts a nested event loop
    if (m_busy)
        return;

    while (newstart < m_inbuffer.size()) {
        int start = newstart;
        int end = m_inbuffer.indexOf('\n', scan);
        if (end < 0) {
            m_inbuffer.remove(0, start);
            return;
        }
        newstart = end + 1;
        scan = newstart;
        if (end == start)
            continue;
        #if defined(Q_OS_WIN)
        if (m_inbuffer.at(end - 1) == '\r') {
            --end;
            if (end == start)
                continue;
        }
        #endif
        m_busy = true;
        handleResponse(QByteArray::fromRawData(m_inbuffer.constData() + start, end - start));
        m_busy = false;
    }
    m_inbuffer.clear();
}

void GdbEngine::interruptInferior()
{
    QTC_ASSERT(state() == InferiorRunning, qDebug() << state(); return);

    setState(InferiorStopping);
    showStatusMessage(tr("Stop requested..."), 5000);

    debugMessage(_("TRYING TO INTERRUPT INFERIOR"));
    m_gdbAdapter->interruptInferior();
}

void GdbEngine::interruptInferiorTemporarily()
{
    interruptInferior();
    foreach (const GdbCommand &cmd, m_commandsToRunOnTemporaryBreak)
        if (cmd.flags & LosesChild) {
            setState(InferiorStopping_Kill);
            break;
        }
}

void GdbEngine::maybeHandleInferiorPidChanged(const QString &pid0)
{
    const qint64 pid = pid0.toLongLong();
    if (pid == 0) {
        debugMessage(_("Cannot parse PID from %1").arg(pid0));
        return;
    }
    if (pid == inferiorPid())
        return;
    debugMessage(_("FOUND PID %1").arg(pid));    

    handleInferiorPidChanged(pid);
    if (m_dumperInjectionLoad)
        tryLoadDebuggingHelpers();
}

void GdbEngine::postCommand(const QString &command, AdapterCallback callback,
                            const char *callbackName, const QVariant &cookie)
{
    postCommand(command, NoFlags, callback, callbackName, cookie);
}

void GdbEngine::postCommand(const QString &command, GdbCommandFlags flags,
                            AdapterCallback callback,
                            const char *callbackName, const QVariant &cookie)
{
    GdbCommand cmd;
    cmd.command = command;
    cmd.flags = flags;
    cmd.adapterCallback = callback;
    cmd.callbackName = callbackName;
    cmd.cookie = cookie;
    postCommandHelper(cmd);
}

void GdbEngine::postCommand(const QString &command, GdbCommandCallback callback,
                            const char *callbackName, const QVariant &cookie)
{
    postCommand(command, NoFlags, callback, callbackName, cookie);
}

void GdbEngine::postCommand(const QString &command, GdbCommandFlags flags,
                            GdbCommandCallback callback, const char *callbackName,
                            const QVariant &cookie)
{
    GdbCommand cmd;
    cmd.command = command;
    cmd.flags = flags;
    cmd.callback = callback;
    cmd.callbackName = callbackName;
    cmd.cookie = cookie;
    postCommandHelper(cmd);
}

void GdbEngine::postCommandHelper(const GdbCommand &cmd)
{
    if (!stateAcceptsGdbCommands(state())) {
        PENDING_DEBUG(_("NO GDB PROCESS RUNNING, CMD IGNORED: ") + cmd.command);
        debugMessage(_("NO GDB PROCESS RUNNING, CMD IGNORED: %1 %2")
            .arg(cmd.command).arg(state()));
        return;
    }

    if (cmd.flags & RebuildModel) {
        ++m_pendingRequests;
        PENDING_DEBUG("   MODEL:" << cmd.command << "=>" << cmd.callbackName
                      << "INCREMENTS PENDING TO" << m_pendingRequests);
    } else {
        PENDING_DEBUG("   OTHER (IN):" << cmd.command << "=>" << cmd.callbackName
                      << "LEAVES PENDING AT" << m_pendingRequests);
    }

    if ((cmd.flags & NeedsStop) || !m_commandsToRunOnTemporaryBreak.isEmpty()) {
        if (state() == InferiorStopped
            || state() == InferiorStarting || state() == AdapterStarted) {
            // Can be safely sent now.
            flushCommand(cmd);
        } else {
            // Queue the commands that we cannot send at once.
            debugMessage(_("QUEUING COMMAND ") + cmd.command);
            m_commandsToRunOnTemporaryBreak.append(cmd);
            if (state() == InferiorStopping) {
                if (cmd.flags & LosesChild)
                    setState(InferiorStopping_Kill);
                debugMessage(_("CHILD ALREADY BEING INTERRUPTED"));
            } else if (state() == InferiorStopping_Kill) {
                debugMessage(_("CHILD ALREADY BEING INTERRUPTED (KILL PENDING)"));
            } else if (state() == InferiorRunningRequested) {
                if (cmd.flags & LosesChild)
                    setState(InferiorRunningRequested_Kill);
                debugMessage(_("RUNNING REQUESTED; POSTPONING INTERRUPT"));
            } else if (state() == InferiorRunningRequested_Kill) {
                debugMessage(_("RUNNING REQUESTED; POSTPONING INTERRUPT (KILL PENDING)"));
            } else if (state() == InferiorRunning) {
                showStatusMessage(tr("Stopping temporarily."), 1000);
                interruptInferiorTemporarily();
            } else {
                qDebug() << "ATTEMPTING TO QUEUE COMMAND IN INAPPROPRIATE STATE" << state();
            }
        }
    } else if (!cmd.command.isEmpty()) {
        flushCommand(cmd);
    }
}

void GdbEngine::flushQueuedCommands()
{
    showStatusMessage(tr("Processing queued commands."), 1000);
    while (!m_commandsToRunOnTemporaryBreak.isEmpty()) {
        GdbCommand cmd = m_commandsToRunOnTemporaryBreak.takeFirst();
        debugMessage(_("RUNNING QUEUED COMMAND %1 %2")
            .arg(cmd.command).arg(_(cmd.callbackName)));
        flushCommand(cmd);
    }
}

void GdbEngine::flushCommand(const GdbCommand &cmd0)
{
    GdbCommand cmd = cmd0;
    if (state() == DebuggerNotReady) {
        gdbInputAvailable(LogInput, cmd.command);
        debugMessage(_("GDB PROCESS NOT RUNNING, PLAIN CMD IGNORED: ") + cmd.command);
        return;
    }

    ++currentToken();
    cmd.postTime = QTime::currentTime();
    m_cookieForToken[currentToken()] = cmd;
    cmd.command = QString::number(currentToken()) + cmd.command;
    if (cmd.flags & EmbedToken)
        cmd.command = cmd.command.arg(currentToken());
    gdbInputAvailable(LogInput, cmd.command);

    m_gdbAdapter->write(cmd.command.toLatin1() + "\r\n");

    m_commandTimer->start();

    if (cmd.flags & LosesChild)
        setState(InferiorShuttingDown);
}

void GdbEngine::commandTimeout()
{
    // FIXME this needs a proper message box
    debugMessage(_("TIMED OUT WAITING FOR GDB REPLY. COMMANDS STILL IN PROGRESS:"));
    QList<int> keys = m_cookieForToken.keys();
    qSort(keys);
    foreach (int key, keys) {
        const GdbCommand &cmd = m_cookieForToken[key];
        debugMessage(_("  %1: %2 => %3").arg(key).arg(cmd.command).arg(_(cmd.callbackName)));
    }
    // This is an entirely undefined state, so we just pull the emergency brake.
    setState(EngineShuttingDown, true);
    m_gdbProc.kill();
}

void GdbEngine::handleResultRecord(GdbResponse *response)
{
    //qDebug() << "TOKEN:" << response.token
    //    << " ACCEPTABLE:" << m_oldestAcceptableToken;
    //qDebug() << "\nRESULT" << response.token << response.toString();

    int token = response->token;
    if (token == -1)
        return;

    if (!m_cookieForToken.contains(token)) {
        // In theory this should not happen (rather the error should be
        // reported in the "first" response to the command) in practice it
        // does. We try to handle a few situations we are aware of gracefully.
        // Ideally, this code should not be present at all.
        debugMessage(_("COOKIE FOR TOKEN %1 ALREADY EATEN. "
            "TWO RESPONSES FOR ONE COMMAND?").arg(token));
        if (response->resultClass == GdbResultError) {
            QByteArray msg = response->data.findChild("msg").data();
            if (msg == "Cannot find new threads: generic error") {
                // Handle a case known to occur on Linux/gdb 6.8 when debugging moc
                // with helpers enabled. In this case we get a second response with
                // msg="Cannot find new threads: generic error"
                debugMessage(_("APPLYING WORKAROUND #1"));
                showMessageBox(QMessageBox::Critical,
                    tr("Executable failed"), QString::fromLocal8Bit(msg));
                showStatusMessage(tr("Process failed to start."));
                shutdown();
            } else if (msg == "\"finish\" not meaningful in the outermost frame.") { 
                // Handle a case known to appear on gdb 6.4 symbianelf when
                // the stack is cut due to access to protected memory.
                debugMessage(_("APPLYING WORKAROUND #2"));
                setState(InferiorStopping);
                setState(