Improve usage message for -qmljsdebugger arguments.

Document all the options available and avoid the extra "Cannot load
plugin" message if invalid options were given by not trying to start
the thread with an empty plugin name.

Change-Id: I87cb4185b58a8672db2ac3ea9c6b8b2155cbbe5d
Reviewed-by: Erik Verbruggen <erik.verbruggen@theqtcompany.com>

1 files changed, 47 insertions, 6 deletions

diff --git a/src/plugins/qmltooling/qmldbg_server/qqmldebugserver.cpp b/src/plugins/qmltooling/qmldbg_server/qqmldebugserver.cpp
index 93e1d0c030..7dd0280a29 100644
--- a/src/plugins/qmltooling/qmldbg_server/qqmldebugserver.cpp
+++ b/src/plugins/qmltooling/qmldbg_server/qqmldebugserver.cpp
@@ -40,6 +40,7 @@
 #include <private/qqmlengine_p.h>
 #include <private/qqmlglobal_p.h>
 #include <private/qqmldebugpluginmanager_p.h>
+#include <private/qqmldebugserviceinterfaces_p.h>
 
 #include <QtCore/QAtomicInt>
 #include <QtCore/QDir>
@@ -105,6 +106,11 @@ public:
         m_fileName = fileName;
     }
 
+    const QString &pluginName() const
+    {
+        return m_pluginName;
+    }
+
     void run();
 
 private:
@@ -310,6 +316,9 @@ bool QQmlDebugServerImpl::open(const QVariantHash &configuration = QVariantHash(
         }
     }
 
+    if (m_thread.pluginName().isEmpty())
+        return false;
+
     QMutexLocker locker(&m_helloMutex);
     m_thread.start();
     m_helloCondition.wait(&m_helloMutex); // wait for connection
@@ -318,6 +327,7 @@ bool QQmlDebugServerImpl::open(const QVariantHash &configuration = QVariantHash(
     return true;
 }
 
+#define qUsage qWarning().noquote().nospace
 void QQmlDebugServerImpl::parseArguments()
 {
     // format: qmljsdebugger=port:<port_from>[,port_to],host:<ip address>][,block]
@@ -366,9 +376,8 @@ void QQmlDebugServerImpl::parseArguments()
         } else if (!services.isEmpty()) {
             services.append(strArgument);
         } else {
-            qWarning() << QString::fromLatin1("QML Debugger: Invalid argument '%1' "
-                                              "detected. Ignoring the same.")
-                                               .arg(strArgument);
+            qUsage() << tr("QML Debugger: Invalid argument \"%1\" detected. Ignoring the same.")
+                        .arg(strArgument);
         }
     }
 
@@ -380,11 +389,43 @@ void QQmlDebugServerImpl::parseArguments()
         else
             m_thread.setPortRange(portFrom, portTo, hostAddress);
     } else {
-        qWarning() << QString::fromLatin1("QML Debugger: Ignoring \"-qmljsdebugger=%1\". "
-                                          "Format is qmljsdebugger=port:<port_from>[,port_to],host:"
-                                          "<ip address>][,block]").arg(args);
+        qUsage() << tr("QML Debugger: Ignoring \"-qmljsdebugger=%1\".").arg(args);
+        qUsage() << tr("The format is \"-qmljsdebugger=[file:<file>|port:<port_from>][,<port_to>]"
+                       "[,host:<ip address>][,block][,services:<service>][,<service>]*\"\n");
+        qUsage() << tr("\"file:\" can be used to specify the name of a file the debugger will try "
+                       "to connect to using a QLocalSocket. If \"file:\" is given any \"host:\" and"
+                       "\"port:\" arguments will be ignored.\n");
+        qUsage() << tr("\"host:\" and \"port:\" can be used to specify an address and a single "
+                       "port or a range of ports the debugger will try to bind to with a "
+                       "QTcpServer.\n");
+        qUsage() << tr("\"block\" makes the debugger and some services wait for clients to be "
+                       "connected and ready before the first QML engine starts.\n");
+        qUsage() << tr("\"services:\" can be used to specify which debug services the debugger "
+                       "should load. Some debug services interact badly with others. The V4 "
+                       "debugger should not be loaded when using the QML profiler as it will force "
+                       "any V4 engines to use the JavaScript interpreter rather than the JIT. The "
+                       "following debug services are available by default:");
+        qUsage() << QQmlEngineDebugService::s_key << tr("\t- The QML debugger");
+        qUsage() << QV4DebugService::s_key        << tr("\t- The V4 debugger");
+        qUsage() << QQmlInspectorService::s_key   << tr("\t- The QML inspector");
+        qUsage() << QQmlProfilerService::s_key    << tr("\t- The QML profiler");
+        qUsage() << QQmlEngineControlService::s_key
+                             << tr("\t- Allows the client to delay the starting and stopping of\n"
+                                   "\t\t  QML engines until other services are ready. QtCreator\n"
+                                   "\t\t  uses this service with the QML profiler in order to\n"
+                                   "\t\t  profile multiple QML engines at the same time.");
+        qUsage() << QDebugMessageService::s_key
+                             << tr("\t- Sends qDebug() and similar messages over the QML debug\n"
+                                   "\t\t  connection. QtCreator uses this for showing debug\n"
+                                   "\t\t  messages in the JavaScript console.");
+        qUsage() << tr("Other services offered by qmltooling plugins that implement "
+                       "QQmlDebugServiceFactory and which can be found in the standard plugin "
+                       "paths will also be available and can be specified. If no \"services\" "
+                       "argument is given, all services found this way, including the default "
+                       "ones, are loaded.");
     }
 }
+#undef qUsage
 
 void QQmlDebugServerImpl::receiveMessage()
 {