diff --git a/src/core/exception.h b/src/core/exception.h
index e293c278..7f5adcf7 100644
--- a/src/core/exception.h
+++ b/src/core/exception.h
@@ -79,6 +79,12 @@ namespace vnotex
             case Type::EssentialFileMissing:
                 return QString("EssentialFileMissing");
 
+            case Type::FileExistsOnCreate:
+                return QString("FileExistsOnCreate");
+
+            case Type::DirExistsOnCreate:
+                return QString("DirExistsOnCreate");
+
             case Type::InvalidArgument:
                 return QString("InvalidArgument");
             }
diff --git a/src/core/notebook/notebookdatabaseaccess.cpp b/src/core/notebook/notebookdatabaseaccess.cpp
index a1e7db51..f291009f 100644
--- a/src/core/notebook/notebookdatabaseaccess.cpp
+++ b/src/core/notebook/notebookdatabaseaccess.cpp
@@ -188,7 +188,6 @@ bool NotebookDatabaseAccess::addNode(Node *p_node, bool p_ignoreId)
     }
 
     const ID id = query.lastInsertId().toULongLong();
-    const ID preId = p_node->getId();
     p_node->updateId(id);
 
     qDebug() << "added node id" << id << p_node->getName();
diff --git a/src/core/notebookmgr.cpp b/src/core/notebookmgr.cpp
index bf301dab..04408ddb 100644
--- a/src/core/notebookmgr.cpp
+++ b/src/core/notebookmgr.cpp
@@ -377,8 +377,9 @@ void NotebookMgr::addNotebook(const QSharedPointer<Notebook> &p_notebook)
 {
     p_notebook->initialize();
     m_notebooks.push_back(p_notebook);
+    auto notebook = p_notebook.data();
     connect(p_notebook.data(), &Notebook::updated,
-            this, [this, notebook = p_notebook.data()]() {
+            this, [this, notebook]() {
                 emit notebookUpdated(notebook);
             });
 }
diff --git a/src/data/extra/web/js/graphpreviewer.js b/src/data/extra/web/js/graphpreviewer.js
index 8c168e8b..58c724fd 100644
--- a/src/data/extra/web/js/graphpreviewer.js
+++ b/src/data/extra/web/js/graphpreviewer.js
@@ -196,7 +196,7 @@ class GraphPreviewer {
     // Fix SVG with stroke="currentColor" and fill="currentColor".
     fixSvgCurrentColor(p_svgNode) {
         let currentColor = this.currentColor;
-        if (currentColor) {
+        if (currentColor && p_svgNode) {
             let nodes = p_svgNode.querySelectorAll("g[fill='currentColor']");
             for (let i = 0; i < nodes.length; ++i) {
                 let node = nodes[i];
@@ -212,7 +212,7 @@ class GraphPreviewer {
 
     scaleSvg(p_svgNode) {
         let scaleFactor = window.devicePixelRatio;
-        if (scaleFactor == 1) {
+        if (scaleFactor == 1 || !p_svgNode) {
             return;
         }
 
diff --git a/src/search/filesearchengine.h b/src/search/filesearchengine.h
index e0c81173..0cd9072d 100644
--- a/src/search/filesearchengine.h
+++ b/src/search/filesearchengine.h
@@ -71,7 +71,7 @@ namespace vnotex
 
         void search(const QSharedPointer<SearchOption> &p_option,
                     const SearchToken &p_token,
-                    const QVector<SearchSecondPhaseItem> &p_items);
+                    const QVector<SearchSecondPhaseItem> &p_items) Q_DECL_OVERRIDE;
 
         void stop() Q_DECL_OVERRIDE;
 
diff --git a/src/search/isearchengine.h b/src/search/isearchengine.h
index 57cb2a7e..4509e6f7 100644
--- a/src/search/isearchengine.h
+++ b/src/search/isearchengine.h
@@ -53,5 +53,4 @@ namespace vnotex
         void logRequested(const QString &p_log);
     };
 }
-
 #endif // ISEARCHENGINE_H
diff --git a/src/widgets/dialogs/imageinsertdialog.cpp b/src/widgets/dialogs/imageinsertdialog.cpp
index 5cfe43de..8de41ddd 100644
--- a/src/widgets/dialogs/imageinsertdialog.cpp
+++ b/src/widgets/dialogs/imageinsertdialog.cpp
@@ -136,7 +136,7 @@ void ImageInsertDialog::setupUI(const QString &p_title,
         auto fixedWidthCheckBox = WidgetsFactory::createCheckBox(tr("Fixed scaling width"), mainWidget);
         fixedWidthCheckBox->setChecked(s_fixedScaleWidth);
         connect(fixedWidthCheckBox, &QCheckBox::stateChanged,
-                this, [this](int p_state) {
+                this, [](int p_state) {
                     s_fixedScaleWidth = p_state == Qt::Checked;
                 });
         gridLayout->addWidget(fixedWidthCheckBox, 4, 1, 1, 1);
diff --git a/src/widgets/dialogs/updater.cpp b/src/widgets/dialogs/updater.cpp
index 71e1e572..c3cb428f 100644
--- a/src/widgets/dialogs/updater.cpp
+++ b/src/widgets/dialogs/updater.cpp
@@ -42,7 +42,7 @@ void Updater::setupUI()
         auto btnBox = getDialogButtonBox();
         auto viewBtn = btnBox->addButton(tr("View Releases"), QDialogButtonBox::AcceptRole);
         connect(viewBtn, &QPushButton::clicked,
-                this, [this]() {
+                this, []() {
                     WidgetUtils::openUrlByDesktop(QUrl("https://github.com/vnotex/vnote/releases"));
                 });
     }
diff --git a/src/widgets/framelessmainwindow/framelessmainwindowlinux.cpp b/src/widgets/framelessmainwindow/framelessmainwindowlinux.cpp
index 17a06a6f..c23fed7f 100644
--- a/src/widgets/framelessmainwindow/framelessmainwindowlinux.cpp
+++ b/src/widgets/framelessmainwindow/framelessmainwindowlinux.cpp
@@ -230,4 +230,10 @@ void FramelessMainWindowLinux::showEvent(QShowEvent *p_event)
     }
 }
 
+#else
+using namespace vnotex;
+
+FramelessMainWindowLinuxDummy::FramelessMainWindowLinuxDummy()
+{
+}
 #endif
diff --git a/src/widgets/framelessmainwindow/framelessmainwindowlinux.h b/src/widgets/framelessmainwindow/framelessmainwindowlinux.h
index 059c8184..c466ed1a 100644
--- a/src/widgets/framelessmainwindow/framelessmainwindowlinux.h
+++ b/src/widgets/framelessmainwindow/framelessmainwindowlinux.h
@@ -64,6 +64,8 @@ namespace vnotex
 #else
     class FramelessMainWindowLinuxDummy
     {
+    public:
+        FramelessMainWindowLinuxDummy();
     };
 #endif
 }
diff --git a/src/widgets/framelessmainwindow/framelessmainwindowwin.cpp b/src/widgets/framelessmainwindow/framelessmainwindowwin.cpp
index 1b2a8299..43b80469 100644
--- a/src/widgets/framelessmainwindow/framelessmainwindowwin.cpp
+++ b/src/widgets/framelessmainwindow/framelessmainwindowwin.cpp
@@ -221,4 +221,10 @@ void FramelessMainWindowWin::forceRedraw()
     }
 }
 
+#else
+using namespace vnotex;
+
+FramelessMainWindowWinDummy::FramelessMainWindowWinDummy()
+{
+}
 #endif
diff --git a/src/widgets/framelessmainwindow/framelessmainwindowwin.h b/src/widgets/framelessmainwindow/framelessmainwindowwin.h
index 7f5e8c14..dddf06d6 100644
--- a/src/widgets/framelessmainwindow/framelessmainwindowwin.h
+++ b/src/widgets/framelessmainwindow/framelessmainwindowwin.h
@@ -40,6 +40,8 @@ namespace vnotex
 #else
     class FramelessMainWindowWinDummy
     {
+    public:
+        FramelessMainWindowWinDummy();
     };
 #endif
 }
diff --git a/src/widgets/markdownviewwindow.cpp b/src/widgets/markdownviewwindow.cpp
index 9564cc27..7c8922e5 100644
--- a/src/widgets/markdownviewwindow.cpp
+++ b/src/widgets/markdownviewwindow.cpp
@@ -282,7 +282,7 @@ void MarkdownViewWindow::setupToolBar()
     {
         auto act = addAction(toolBar, ViewWindowToolBarHelper::InplacePreview);
         connect(act, &QAction::triggered,
-                this, [this, act](bool p_checked) {
+                this, [this](bool p_checked) {
                     if (!isReadMode()) {
                         m_editor->setInplacePreviewEnabled(p_checked);
                     }
diff --git a/src/widgets/searchpanel.cpp b/src/widgets/searchpanel.cpp
index ee4d0e12..ca39a546 100644
--- a/src/widgets/searchpanel.cpp
+++ b/src/widgets/searchpanel.cpp
@@ -142,7 +142,7 @@ TitleBar *SearchPanel::setupTitleBar(const QString &p_title, QWidget *p_parent)
 
         auto toggleLocationListBtn = titleBar->addActionButton(QStringLiteral("search_location_list.svg"), tr("Toggle Location List"));
         connect(toggleLocationListBtn, &QToolButton::triggered,
-                this, [this]() {
+                this, []() {
                     VNoteX::getInst().getMainWindow()->toggleLocationListVisible();
                 });
 
diff --git a/src/widgets/snippetpanel.cpp b/src/widgets/snippetpanel.cpp
index 35081942..aefb5927 100644
--- a/src/widgets/snippetpanel.cpp
+++ b/src/widgets/snippetpanel.cpp
@@ -69,7 +69,7 @@ void SnippetPanel::setupTitleBar(const QString &p_title, QWidget *p_parent)
     {
         auto openFolderBtn = m_titleBar->addActionButton(QStringLiteral("open_folder.svg"), tr("Open Folder"));
         connect(openFolderBtn, &QToolButton::triggered,
-                this, [this]() {
+                this, []() {
                     WidgetUtils::openUrlByDesktop(QUrl::fromLocalFile(SnippetMgr::getInst().getSnippetFolder()));
                 });
     }
diff --git a/src/widgets/styleditemdelegate.cpp b/src/widgets/styleditemdelegate.cpp
index 98197432..f3011515 100644
--- a/src/widgets/styleditemdelegate.cpp
+++ b/src/widgets/styleditemdelegate.cpp
@@ -16,14 +16,14 @@
 using namespace vnotex;
 
 StyledItemDelegateListWidget::StyledItemDelegateListWidget(const ListWidget *p_listWidget)
-    : m_listWidget(p_listWidget)
 {
+    Q_UNUSED(p_listWidget);
 }
 
 
 StyledItemDelegateTreeWidget::StyledItemDelegateTreeWidget(const TreeWidget *p_treeWidget)
-    : m_treeWidget(p_treeWidget)
 {
+    Q_UNUSED(p_treeWidget);
 }
 
 
diff --git a/src/widgets/styleditemdelegate.h b/src/widgets/styleditemdelegate.h
index e7e8ced8..f0887691 100644
--- a/src/widgets/styleditemdelegate.h
+++ b/src/widgets/styleditemdelegate.h
@@ -35,9 +35,6 @@ namespace vnotex
     {
     public:
         explicit StyledItemDelegateListWidget(const ListWidget *p_listWidget);
-
-    private:
-        const ListWidget *m_listWidget = nullptr;
     };
 
 
@@ -45,9 +42,6 @@ namespace vnotex
     {
     public:
         explicit StyledItemDelegateTreeWidget(const TreeWidget *p_treeWidget);
-
-    private:
-        const TreeWidget *m_treeWidget = nullptr;
     };
 
 
diff --git a/src/widgets/systemtrayhelper.cpp b/src/widgets/systemtrayhelper.cpp
index 1b97bc06..19df4bec 100644
--- a/src/widgets/systemtrayhelper.cpp
+++ b/src/widgets/systemtrayhelper.cpp
@@ -24,6 +24,7 @@ QSystemTrayIcon *SystemTrayHelper::setupSystemTray(MainWindow *p_win)
 
     MainWindow::connect(trayIcon, &QSystemTrayIcon::activated,
                         p_win, [p_win](QSystemTrayIcon::ActivationReason p_reason) {
+                            Q_UNUSED(p_reason);
 #if !defined(Q_OS_MACOS)
                             if (p_reason == QSystemTrayIcon::Trigger) {
                                 p_win->showMainWindow();
diff --git a/src/widgets/tagpopup.cpp b/src/widgets/tagpopup.cpp
index 065c6898..e20b3f0d 100644
--- a/src/widgets/tagpopup.cpp
+++ b/src/widgets/tagpopup.cpp
@@ -16,6 +16,12 @@ TagPopup::TagPopup(QToolButton *p_btn, QWidget *p_parent)
 {
     setupUI();
 
+#if defined(Q_OS_MACOS) || defined(Q_OS_MAC)
+    // Qt::Popup on macOS does not work well with input method.
+    setWindowFlags(Qt::Tool | Qt::NoDropShadowWindowHint);
+    setWindowModality(Qt::ApplicationModal);
+#endif
+
     connect(this, &QMenu::aboutToShow,
             this, [this]() {
                 m_tagViewer->setNode(m_buffer ? m_buffer->getNode() : nullptr);