Move mcu deploy step into the mcusupport plugin

This deploy step will run the qmlprojectexporter commandline tool
on the currently active qmlproject if qtForMCUs is set to true.
The output of the tool is shown in the "Compile Output" panel.
Possible configuration issues are shown in the "Issues" panel.
Note that the step is not removed from the list but disabled when
setting qtForMCUs to false in order to retain possible changes made
by the user.

Change-Id: I03b0d6fbe420b49400d48e7365d4395491b9aa2d
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>
Reviewed-by: hjk <hjk@qt.io>

src/plugins/qmlprojectmanager/buildsystem/qmlbuildsystem.cpp

@@ -3,7 +3,6 @@
 
 #include "qmlbuildsystem.h"
 #include "qmlprojectconstants.h"
-#include "mcubuildstep.h"
 
 #include <QtCore5Compat/qtextcodec.h>
 #include <qmljs/qmljsmodelmanagerinterface.h>
@@ -18,6 +17,10 @@
 #include <coreplugin/icore.h>
 #include <coreplugin/messagemanager.h>
 
+#include <extensionsystem/iplugin.h>
+#include <extensionsystem/pluginmanager.h>
+#include <extensionsystem/pluginspec.h>
+
 #include <projectexplorer/deploymentdata.h>
 #include <projectexplorer/devicesupport/idevice.h>
 #include <projectexplorer/kitinformation.h>
@@ -41,6 +44,31 @@ namespace {
 Q_LOGGING_CATEGORY(infoLogger, "QmlProjectManager.QmlBuildSystem", QtInfoMsg)
 }
 
+ExtensionSystem::IPlugin *findMcuSupportPlugin()
+{
+    const ExtensionSystem::PluginSpec *pluginSpec = Utils::findOrDefault(
+        ExtensionSystem::PluginManager::plugins(),
+        Utils::equal(&ExtensionSystem::PluginSpec::name, QString("McuSupport")));
+
+    if (pluginSpec)
+        return pluginSpec->plugin();
+    return nullptr;
+}
+
+void updateMcuBuildStep(Target *target, bool mcuEnabled)
+{
+    if (auto plugin = findMcuSupportPlugin()) {
+        QMetaObject::invokeMethod(
+            plugin,
+            "updateDeployStep",
+            Qt::DirectConnection,
+            Q_ARG(ProjectExplorer::Target*, target),
+            Q_ARG(bool, mcuEnabled));
+    } else if (mcuEnabled) {
+        qWarning() << "Failed to find McuSupport plugin but qtForMCUs is enabled in the project";
+    }
+}
+
 QmlBuildSystem::QmlBuildSystem(Target *target)
     : BuildSystem(target)
 {
@@ -52,11 +80,11 @@ QmlBuildSystem::QmlBuildSystem(Target *target)
 
     connect(target->project(), &Project::activeTargetChanged, [this](Target *target) {
         refresh(RefreshOptions::NoFileRefresh);
-        if (qtForMCUs())
-            MCUBuildStepFactory::attachToTarget(target);
+        updateMcuBuildStep(target, qtForMCUs());
     });
     connect(target->project(), &Project::projectFileIsDirty, [this]() {
         refresh(RefreshOptions::Project);
+        updateMcuBuildStep(project()->activeTarget(), qtForMCUs());
     });
 
     // FIXME: Check. Probably bogus after the BuildSystem move.