Meson build plugin initial support

Most basic project management is implemented:
- Project config/build
- Build options accessible to user
- Lists most build targets
- Meson and Ninja added to kit setup
- Basic project file tree with files known by Meson
- Some basic meson and ninja process output parsing
- Some project templates

Missing features, that will come later:
- Configurable project tree layout
- Locators for Meson
- Build importer
- Access to Machine files for better user fine tuning
- ...

Fixes: QTCREATORBUG-18117
Change-Id: I2811e71562c113fb0fc6b6177bcf0698fa71ef63
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/mesonprojectmanager/mesonprojectplugin.cpp

@@ -0,0 +1,121 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 Alexis Jeandet.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include "mesonprojectplugin.h"
+#include "exewrappers/mesonwrapper.h"
+#include "machinefiles/machinefilemanager.h"
+#include "mesonactionsmanager/mesonactionsmanager.h"
+#include "project/mesonbuildconfiguration.h"
+#include "project/mesonbuildsystem.h"
+#include "project/mesonproject.h"
+#include "project/mesonrunconfiguration.h"
+#include "project/ninjabuildstep.h"
+#include "settings/general/generalsettingspage.h"
+#include "settings/tools/kitaspect/mesontoolkitaspect.h"
+#include "settings/tools/kitaspect/ninjatoolkitaspect.h"
+#include "settings/tools/toolssettingsaccessor.h"
+#include "settings/tools/toolssettingspage.h"
+
+#include <coreplugin/actionmanager/actioncontainer.h>
+#include <coreplugin/actionmanager/actionmanager.h>
+#include <coreplugin/icore.h>
+
+#include <projectexplorer/projectexplorer.h>
+#include <projectexplorer/projectmanager.h>
+#include <projectexplorer/runcontrol.h>
+
+#include <extensionsystem/pluginmanager.h>
+
+#include <utils/parameteraction.h>
+
+#include <QObject>
+
+using namespace Core;
+using namespace ProjectExplorer;
+using namespace Utils;
+
+namespace MesonProjectManager {
+namespace Internal {
+
+class MesonProjectPluginPrivate : public QObject
+{
+    Q_OBJECT
+public:
+    MesonProjectPluginPrivate()
+    {
+        MesonTools::setTools(m_toolsSettings.loadMesonTools(ICore::dialogParent()));
+        connect(ICore::instance(),
+                &ICore::saveSettingsRequested,
+                this,
+                &MesonProjectPluginPrivate::saveAll);
+    }
+
+    ~MesonProjectPluginPrivate() {}
+
+private:
+    GeneralSettingsPage m_generalSettingsPage;
+    ToolsSettingsPage m_toolslSettingsPage;
+    ToolsSettingsAccessor m_toolsSettings;
+    MesonToolKitAspect m_mesonKitAspect;
+    NinjaToolKitAspect m_ninjaKitAspect;
+    MesonBuildStepFactory m_buildStepFactory;
+    MesonBuildConfigurationFactory m_buildConfigurationFactory;
+    MesonRunConfigurationFactory m_runConfigurationFactory;
+    MesonActionsManager m_actions;
+    MachineFileManager m_machineFilesManager;
+    RunWorkerFactory
+        m_mesonRunWorkerFactory{RunWorkerFactory::make<ProjectExplorer::SimpleTargetRunner>(),
+                                {ProjectExplorer::Constants::NORMAL_RUN_MODE},
+                                {m_runConfigurationFactory.id()}};
+    void saveAll()
+    {
+        m_toolsSettings.saveMesonTools(MesonTools::tools(), ICore::dialogParent());
+        m_generalSettingsPage.saveAll();
+    }
+};
+
+MesonProjectPlugin::~MesonProjectPlugin()
+{
+    delete d;
+}
+
+bool MesonProjectPlugin::initialize(const QStringList & /*arguments*/, QString *errorMessage)
+{
+    Q_UNUSED(errorMessage)
+
+    d = new MesonProjectPluginPrivate;
+
+    ProjectManager::registerProjectType<MesonProject>(Constants::Project::MIMETYPE);
+    FileIconProvider::registerIconOverlayForFilename(Constants::Icons::MESON, "meson.build");
+    FileIconProvider::registerIconOverlayForFilename(Constants::Icons::MESON, "meson_options.txt");
+    return true;
+}
+
+void MesonProjectPlugin::extensionsInitialized() {}
+
+} // namespace Internal
+} // namespace MesonProjectManager
+
+#include "mesonprojectplugin.moc"