loghandler.cpp

// SPDX-FileCopyrightText: Copyright (C) 2014 swift Project Community / Contributors
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-swift-pilot-client-1
 
 
#include "misc/loghandler.h"
 
#include "config/buildconfig.h"
#include "misc/algorithm.h"
#include "misc/mixin/mixincompare.h"
#include "misc/threadutils.h"
 
#ifdef SWIFT_USE_CRASHPAD
#    include "crashpad/client/simulate_crash.h"
#endif
 
#include <algorithm>
 
#include <QAbstractNativeEventFilter>
#include <QCoreApplication>
#include <QGlobalStatic>
#include <QMessageLogContext>
#include <QMetaMethod>
#include <QString>
#include <Qt>
#include <QtDebug>
 
#ifdef Q_OS_WIN
#    include <windows.h>
#endif
 
namespace swift::misc
{
    Q_GLOBAL_STATIC(CLogHandler, g_handler)
 
    CLogHandler *CLogHandler::instance()
    {
        Q_ASSERT(!g_handler.isDestroyed());
        return g_handler;
    }
 
    void messageHandler(QtMsgType type, const QMessageLogContext &context, const QString &message)
    {
        if (type == QtFatalMsg && CLogHandler::instance()->thread() != QThread::currentThread())
        {
            // Fatal message means this thread is about to crash the application. A queued connection would be useless.
            // Blocking queued connection means we pause this thread just long enough to let the main thread handle the
            // message.
            QMetaObject::invokeMethod(
                CLogHandler::instance(), [&] { messageHandler(type, context, message); }, Qt::BlockingQueuedConnection);
            return;
        }
#if defined(Q_CC_MSVC) && defined(QT_NO_DEBUG)
        if (type == QtFatalMsg)
        {
            struct EventFilter : public QAbstractNativeEventFilter
            {
                // Prevent Qt from handling Windows Messages while the messagebox is open
                virtual bool nativeEventFilter(const QByteArray &, void *message, qintptr *result) override
                {
                    auto msg = static_cast<MSG *>(message);
                    *result = DefWindowProc(msg->hwnd, msg->message, msg->wParam, msg->lParam);
                    return true;
                }
            };
            EventFilter ef;
            qApp->installNativeEventFilter(&ef);
            MessageBoxW(nullptr, message.toStdWString().c_str(), nullptr,
                        MB_OK); // display assert dialog in release build
            qApp->removeNativeEventFilter(&ef);
#    if defined(SWIFT_USE_CRASHPAD)
            CRASHPAD_SIMULATE_CRASH(); // workaround inability to catch __fastfail
#    endif
        }
#endif
        QMetaObject::invokeMethod(CLogHandler::instance(), [statusMessage = CStatusMessage(type, context, message)] {
            CLogHandler::instance()->logLocalMessage(statusMessage);
        });
    }
 
    void CLogHandler::install(bool skipIfAlreadyInstalled)
    {
        if (skipIfAlreadyInstalled && m_oldHandler) { return; }
        Q_ASSERT_X(!m_oldHandler, Q_FUNC_INFO, "Re-installing the log handler should be avoided");
        m_oldHandler = qInstallMessageHandler(messageHandler);
    }
 
    CLogHandler::CLogHandler()
    {
        // in case the first call to instance() is in a different thread
        moveToThread(QCoreApplication::instance()->thread());
    }
 
    CLogHandler::~CLogHandler() { qInstallMessageHandler(m_oldHandler); }
 
    CLogPatternHandler *CLogHandler::handlerForPattern(const CLogPattern &pattern)
    {
        Q_ASSERT(thread() == QThread::currentThread());
 
        auto finder = [&](const PatternPair &pair) { return pair.first == pattern; };
        auto comparator = [](const PatternPair &a, const PatternPair &b) { return a.first.isProperSubsetOf(b.first); };
 
        auto it = std::find_if(m_patternHandlers.cbegin(), m_patternHandlers.cend(), finder);
        if (it == m_patternHandlers.cend())
        {
            auto *handler = new CLogPatternHandler(this, pattern);
            topologicallySortedInsert(m_patternHandlers, PatternPair(pattern, handler), comparator);
            return handler;
        }
        else { return (*it).second; }
    }
 
    CLogPatternHandler *CLogHandler::handlerForCategory(const CLogCategory &category)
    {
        return handlerForPattern(CLogPattern::exactMatch(category));
    }
 
    QList<CLogPatternHandler *> CLogHandler::handlersForMessage(const CStatusMessage &message) const
    {
        QList<CLogPatternHandler *> m_handlers;
        for (const auto &pair : m_patternHandlers)
        {
            if (pair.first.match(message)) { m_handlers.push_back(pair.second); }
        }
        return m_handlers;
    }
 
    bool CLogHandler::isFallThroughEnabled(const QList<CLogPatternHandler *> &handlers) const
    {
        for (const auto *handler : handlers)
        {
            if (!handler->m_inheritFallThrough) { return handler->m_enableFallThrough; }
        }
        return m_enableFallThrough;
    }
 
    void CLogHandler::logLocalMessage(const CStatusMessage &i_statusMessage)
    {
        using namespace swift::config;
        CStatusMessage statusMessage = i_statusMessage;
        if (!CBuildConfig::isLocalDeveloperDebugBuild() &&
            CLogPattern::empty().withSeverity(CStatusMessage::SeverityError).match(statusMessage))
        {
            // 99% this is a complex Qt implementation warning generated by qErrnoWarning, so downgrade its severity
            statusMessage.setSeverity(CStatusMessage::SeverityDebug);
        }
 
        if (!CBuildConfig::isLocalDeveloperDebugBuild() &&
            CLogPattern::exactMatch("default").withSeverity(CStatusMessage::SeverityWarning).match(statusMessage))
        {
            // All Qt warnings
 
            // demoted because caused by airline icons, we would need to re-create literally dozens of these images
            if (statusMessage.getMessage().startsWith(QStringLiteral("libpng warning")))
            {
                statusMessage.setSeverity(CStatusMessage::SeverityDebug);
            }
 
            // demoted, because in some swift APPs some options can be ignored
            else if (statusMessage.getMessage().startsWith(QStringLiteral("QCommandLineParser: option not defined")))
            {
                statusMessage.setSeverity(CStatusMessage::SeverityDebug);
            }
        }
 
        auto bucket = m_tokenBuckets.find(statusMessage);
        if (bucket == m_tokenBuckets.end()) { bucket = m_tokenBuckets.insert(statusMessage, { { 5, 1000, 1 }, 0 }); }
        if (!bucket->first.tryConsume())
        {
            bucket->second++;
            return;
        }
        if (bucket->second > 0)
        {
            auto copy = statusMessage;
            copy.appendMessage(QStringLiteral(" (+%1 identical messages)").arg(bucket->second));
            bucket->second = 0;
 
            logMessage(copy);
            emit localMessageLogged(copy);
            return;
        }
 
        logMessage(statusMessage);
        emit localMessageLogged(statusMessage);
    }
 
    void CLogHandler::logRemoteMessage(const CStatusMessage &statusMessage)
    {
        logMessage(statusMessage);
        emit remoteMessageLogged(statusMessage);
    }
 
    void swift::misc::CLogHandler::enableConsoleOutput(bool enable)
    {
        Q_ASSERT_X(m_oldHandler, Q_FUNC_INFO, "Install the log handler before using it");
        Q_ASSERT_X(thread() == QThread::currentThread(), Q_FUNC_INFO, "Wrong thread");
        m_enableFallThrough = enable;
    }
 
    void CLogHandler::logMessage(const CStatusMessage &statusMessage)
    {
        const auto handlers = handlersForMessage(statusMessage);
 
        if (isFallThroughEnabled(handlers))
        {
            Q_ASSERT_X(m_oldHandler, Q_FUNC_INFO, "Handler must be installed");
            QtMsgType type;
            QString category;
            QString message;
            statusMessage.toQtLogTriple(&type, &category, &message);
            m_oldHandler(type, QMessageLogContext(nullptr, 0, nullptr, qPrintable(category)), message);
        }
 
        for (auto *handler : handlers) { emit handler->messageLogged(statusMessage); }
    }
 
    void CLogHandler::removePatternHandler(CLogPatternHandler *handler)
    {
        auto it = std::find_if(m_patternHandlers.begin(), m_patternHandlers.end(),
                               [handler](const PatternPair &pair) { return pair.second == handler; });
        if (it != m_patternHandlers.end())
        {
            it->second->deleteLater();
            m_patternHandlers.erase(it);
        }
    }
 
    QList<CLogPattern> CLogHandler::getAllSubscriptions() const
    {
        QList<CLogPattern> result;
        for (const auto &pair : m_patternHandlers)
        {
            if (pair.second->isSignalConnected(QMetaMethod::fromSignal(&CLogPatternHandler::messageLogged)))
            {
                result.push_back(pair.first);
            }
        }
        return result;
    }
 
    CLogPatternHandler::CLogPatternHandler(CLogHandler *parent, const CLogPattern &pattern)
        : QObject(parent), m_parent(parent), m_pattern(pattern)
    {
        connect(&m_subscriptionUpdateTimer, &QTimer::timeout, this, &CLogPatternHandler::updateSubscription);
        m_subscriptionUpdateTimer.start(1);
    }
 
    void CLogPatternHandler::updateSubscription()
    {
        if (m_subscriptionNeedsUpdate)
        {
            m_subscriptionNeedsUpdate = false;
            bool isSubscribed = isSignalConnected(QMetaMethod::fromSignal(&CLogPatternHandler::messageLogged));
 
            if (isSubscribed != m_isSubscribed)
            {
                m_isSubscribed = isSubscribed;
                if (m_isSubscribed) { emit m_parent->subscriptionAdded(m_pattern); }
                else { emit m_parent->subscriptionRemoved(m_pattern); }
            }
 
            if (m_inheritFallThrough && !m_isSubscribed) { m_parent->removePatternHandler(this); }
        }
    }
 
    void CLogSubscriber::changeSubscription(const CLogPattern &pattern)
    {
        if (CLogHandler::instance()->thread() != QThread::currentThread())
        {
            Q_ASSERT(thread() == QThread::currentThread());
            singleShot(0, CLogHandler::instance(), [pattern, self = QPointer<CLogSubscriber>(this)]() {
                if (self) { self->changeSubscription(pattern); }
            });
            return;
        }
 
        unsubscribe();
        m_handler = CLogHandler::instance()->handlerForPattern(pattern);
 
        if (!m_inheritFallThrough) { m_handler->enableConsoleOutput(m_enableFallThrough); }
        connect(m_handler.data(), &CLogPatternHandler::messageLogged, this, &CLogSubscriber::ps_logMessage,
                Qt::DirectConnection);
    }
 
    void CLogSubscriber::unsubscribe()
    {
        if (CLogHandler::instance()->thread() != QThread::currentThread())
        {
            Q_ASSERT(thread() == QThread::currentThread());
            singleShot(0, CLogHandler::instance(), [self = QPointer<CLogSubscriber>(this)]() {
                if (self) { self->unsubscribe(); }
            });
            return;
        }
 
        if (m_handler)
        {
            if (!m_inheritFallThrough) { m_handler->inheritConsoleOutput(); }
            m_handler->disconnect(this);
        }
    }
 
    void CLogSubscriber::inheritConsoleOutput()
    {
        if (CLogHandler::instance()->thread() != QThread::currentThread())
        {
            Q_ASSERT(thread() == QThread::currentThread());
            singleShot(0, CLogHandler::instance(), [self = QPointer<CLogSubscriber>(this)]() {
                if (self) { self->inheritConsoleOutput(); }
            });
            return;
        }
 
        m_inheritFallThrough = true;
        if (m_handler) { m_handler->inheritConsoleOutput(); }
    }
 
    void CLogSubscriber::enableConsoleOutput(bool enable)
    {
        if (CLogHandler::instance()->thread() != QThread::currentThread())
        {
            Q_ASSERT(thread() == QThread::currentThread());
            singleShot(0, CLogHandler::instance(), [enable, self = QPointer<CLogSubscriber>(this)]() {
                if (self) { self->enableConsoleOutput(enable); }
            });
            return;
        }
 
        m_inheritFallThrough = false;
        m_enableFallThrough = enable;
        if (m_handler) { m_handler->enableConsoleOutput(enable); }
    }
} // namespace swift::misc