Obtain script backtrace when a log event is generated in C++ code

interface/src/Application.cpp

@@ -255,6 +255,7 @@
 #include "AboutUtil.h"
 #include "ExternalResource.h"
 #include <ThreadHelpers.h>
+#include "ScriptEngineLoggingAgent.h"
 
 #if defined(Q_OS_WIN)
 #include <VersionHelpers.h>
@@ -7652,6 +7653,9 @@ void Application::registerScriptEngineWithApplicationServices(const ScriptEngine
     connect(scriptEngine.data(), &ScriptEngine::infoMessage, scriptEngines, &ScriptEngines::onInfoMessage);
     connect(scriptEngine.data(), &ScriptEngine::clearDebugWindow, scriptEngines, &ScriptEngines::onClearDebugWindow);
 
+
+    ScriptEngineLoggingAgent *scriptLogger = new ScriptEngineLoggingAgent(scriptEngine.data());
+    scriptEngine->setAgent(scriptLogger);
 }
 
 bool Application::canAcceptURL(const QString& urlString) const {

libraries/script-engine/src/ScriptEngine.cpp

@@ -78,6 +78,7 @@
 #include "ScriptEngines.h"
 #include "StackTestScriptingInterface.h"
 #include "ModelScriptingInterface.h"
+#include "ScriptEngineLoggingAgent.h"
 
 #include <Profile.h>
 

libraries/script-engine/src/ScriptEngineLoggingAgent.cpp

@@ -0,0 +1,52 @@
+//
+//  ScriptEngineLoggingAgent.cpp
+//  script-engine/src
+//
+//  Created by Dale Glass on 04/04/2021.
+//  Copyright 2021 Vircadia Contributors
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "ScriptEngineLoggingAgent.h"
+#include "ScriptContextHelper.h"
+#include <QObject>
+#include <QScriptEngine>
+#include <QDebug>
+#include <QLoggingCategory>
+#include <QScriptContextInfo>
+
+Q_LOGGING_CATEGORY(script_logger, "vircadia.script-engine.logging-agent")
+
+
+ScriptEngineLoggingAgent::ScriptEngineLoggingAgent(QScriptEngine *engine) : QScriptEngineAgent(engine) {
+
+}
+
+void ScriptEngineLoggingAgent::functionEntry(qint64 scriptId) {
+    if ( scriptId != -1) {
+        // We only care about non-native functions
+        return;
+    }
+
+    QStringList backtrace;
+    if (_lock.try_lock()) {
+        // We may end up calling ourselves through backtrace(). In such a case, do nothing to avoid
+        // getting into an infinite loop.
+        backtrace = engine()->currentContext()->backtrace();
+        _lock.unlock();
+    }
+
+    ScriptContextHelper::push( backtrace );
+}
+
+void ScriptEngineLoggingAgent::functionExit(qint64 scriptId, const QScriptValue &returnValue) {
+    if ( scriptId != -1) {
+        // We only care about non-native functions
+        return;
+    }
+
+    ScriptContextHelper::pop();
+}
+

libraries/script-engine/src/ScriptEngineLoggingAgent.h

@@ -0,0 +1,35 @@
+//
+//  ScriptEngineLoggingAgent.h
+//  script-engine/src
+//
+//  Created by Dale Glass on 04/04/2021.
+//  Copyright 2021 Vircadia Contributors
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#ifndef vircadia_ScriptEngineLoggingAgent_h
+#define vircadia_ScriptEngineLoggingAgent_h
+
+#include <QObject>
+#include <QStringList>
+#include <QScriptEngineAgent>
+#include <QThreadStorage>
+#include <QLoggingCategory>
+#include <mutex>
+
+Q_DECLARE_LOGGING_CATEGORY(script_logger)
+
+
+
+class ScriptEngineLoggingAgent : public QScriptEngineAgent {
+public:
+    ScriptEngineLoggingAgent(QScriptEngine *engine);
+    virtual void functionEntry(qint64 scriptId) override;
+    virtual void functionExit(qint64 scriptId, const QScriptValue &returnValue) override;
+private:
+    std::mutex _lock;
+};
+
+#endif

libraries/shared/src/LogHandler.cpp

@@ -28,6 +28,7 @@
 #include <QtCore/QMutexLocker>
 #include <QtCore/QThread>
 #include <QtCore/QTimer>
+#include "ScriptContextHelper.h"
 
 QMutex LogHandler::_mutex(QMutex::Recursive);
 
@@ -209,6 +210,21 @@ QString LogHandler::printMessage(LogMsgType type, const QMessageLogContext& cont
             fprintf(stdout, "[Previous message was repeated %i times]\n", _repeatCount);
         }
 
+        if (context.category && strcmp(context.category, "vircadia.script-engine.logging-agent") != 0 ) {
+            QStringList context = ScriptContextHelper::get();
+            if ( !context.isEmpty()) {
+#ifdef Q_OS_WIN
+                OutputDebugStringA(qPrintable(QString("Script context:\n")));
+#endif
+                fprintf(stdout, "Script context:\n");
+                for( auto line : context) {
+                    fprintf(stdout, "\t%s\n", line.toStdString().c_str());
+#ifdef Q_OS_WIN
+                    OutputDebugStringA(qPrintable(line));
+#endif
+                }
+            }
+        }
         fprintf(stdout, "%s%s%s", color, qPrintable(logMessage), resetColor);
         _repeatCount = 0;
     } else {

libraries/shared/src/ScriptContextHelper.cpp

@@ -0,0 +1,45 @@
+//
+//  ScriptContextHelper.cpp
+//  shared/src
+//
+//  Created by Dale Glass on 04/04/2021.
+//  Copyright 2021 Vircadia Contributors
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#include "ScriptContextHelper.h"
+
+QThreadStorage<QList<QStringList>> ScriptContextHelper::_context;
+
+void  ScriptContextHelper::push(QStringList context) {
+    QList<QStringList> data = _context.localData();
+
+    data.append(context);
+
+    _context.setLocalData(data);
+}
+
+QStringList ScriptContextHelper::get() {
+    QList<QStringList> data = _context.localData();
+
+    if ( data.isEmpty() ) {
+        return QStringList();
+    } else {
+        return data.last();
+    }
+
+    //return _context.localData();
+}
+
+void ScriptContextHelper::pop() {
+    QList<QStringList> data = _context.localData();
+
+    if (!data.isEmpty()) {
+        data.removeLast();
+    }
+
+    _context.setLocalData(data);
+}
+

libraries/shared/src/ScriptContextHelper.h

@@ -0,0 +1,31 @@
+//
+//  ScriptContextHelper.h
+//  shared/src
+//
+//  Created by Dale Glass on 04/04/2021.
+//  Copyright 2021 Vircadia Contributors
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+#ifndef vircadia_ScriptContextHelper_h
+#define vircadia_ScriptContextHelper_h
+
+#include <QObject>
+#include <QStringList>
+#include <QThreadStorage>
+#include <QList>
+
+
+class ScriptContextHelper {
+public:
+    static void push(QStringList context);
+    static QStringList get();
+    static void pop();
+
+private:
+    static QThreadStorage<QList<QStringList>> _context;
+};
+
+#endif