Move clang diagnostics config settings to clangd settings page

It was confusing to have both "Clang Code Model" and "clangd" project
settings pages, so we merge them.
Along the way, a lot of code dropped off.

Change-Id: I780850b716195c3729403ae59f0794c11b5c556d
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: David Schulz <david.schulz@qt.io>

26 files changed, 145 insertions, 1005 deletions

diff --git a/src/plugins/clangcodemodel/CMakeLists.txt b/src/plugins/clangcodemodel/CMakeLists.txt
index 9d08105a6a..7bcfb4e7a9 100644
--- a/src/plugins/clangcodemodel/CMakeLists.txt
+++ b/src/plugins/clangcodemodel/CMakeLists.txt
@@ -25,8 +25,6 @@ add_qtc_plugin(ClangCodeModel
     clangdlocatorfilters.cpp clangdlocatorfilters.h
     clangmodelmanagersupport.cpp clangmodelmanagersupport.h
     clangpreprocessorassistproposalitem.cpp clangpreprocessorassistproposalitem.h
-    clangprojectsettings.cpp clangprojectsettings.h
-    clangprojectsettingswidget.cpp clangprojectsettingswidget.h clangprojectsettingswidget.ui
     clangtextmark.cpp clangtextmark.h
     clanguiheaderondiskmanager.cpp clanguiheaderondiskmanager.h
     clangutils.cpp clangutils.h
diff --git a/src/plugins/clangcodemodel/clangcodemodel.qbs b/src/plugins/clangcodemodel/clangcodemodel.qbs
index 1c0ad2e764..f1d2c89497 100644
--- a/src/plugins/clangcodemodel/clangcodemodel.qbs
+++ b/src/plugins/clangcodemodel/clangcodemodel.qbs
@@ -50,11 +50,6 @@ QtcPlugin {
         "clangmodelmanagersupport.h",
         "clangpreprocessorassistproposalitem.cpp",
         "clangpreprocessorassistproposalitem.h",
-        "clangprojectsettings.cpp",
-        "clangprojectsettings.h",
-        "clangprojectsettingswidget.cpp",
-        "clangprojectsettingswidget.h",
-        "clangprojectsettingswidget.ui",
         "clangtextmark.cpp",
         "clangtextmark.h",
         "clanguiheaderondiskmanager.cpp",
diff --git a/src/plugins/clangcodemodel/clangcodemodelplugin.cpp b/src/plugins/clangcodemodel/clangcodemodelplugin.cpp
index 17cd0b6ba9..3b26d7b82c 100644
--- a/src/plugins/clangcodemodel/clangcodemodelplugin.cpp
+++ b/src/plugins/clangcodemodel/clangcodemodelplugin.cpp
@@ -26,7 +26,6 @@
 #include "clangcodemodelplugin.h"
 
 #include "clangconstants.h"
-#include "clangprojectsettingswidget.h"
 #include "clangutils.h"
 
 #ifdef WITH_TESTS
@@ -42,6 +41,7 @@
 #include <coreplugin/messagemanager.h>
 #include <coreplugin/progressmanager/progressmanager.h>
 
+#include <cppeditor/clangdiagnosticconfig.h>
 #include <cppeditor/cppmodelmanager.h>
 
 #include <projectexplorer/buildconfiguration.h>
@@ -58,16 +58,6 @@ using namespace Utils;
 namespace ClangCodeModel {
 namespace Internal {
 
-static void addProjectPanelWidget()
-{
-    auto panelFactory = new ProjectExplorer::ProjectPanelFactory();
-    panelFactory->setPriority(60);
-    panelFactory->setDisplayName(ClangProjectSettingsWidget::tr("Clang Code Model"));
-    panelFactory->setCreateWidgetFunction(
-        [&](ProjectExplorer::Project *project) { return new ClangProjectSettingsWidget(project); });
-    ProjectExplorer::ProjectPanelFactory::registerFactory(panelFactory);
-}
-
 void ClangCodeModelPlugin::generateCompilationDB()
 {
     using namespace CppEditor;
@@ -80,13 +70,11 @@ void ClangCodeModelPlugin::generateCompilationDB()
     if (!projectInfo)
         return;
 
-    const CppEditor::ClangDiagnosticConfig warningsConfig
-            = warningsConfigForProject(target->project());
     QFuture<GenerateCompilationDbResult> task
             = Utils::runAsync(&Internal::generateCompilationDB, projectInfo,
                               projectInfo->buildRoot(), CompilationDbPurpose::Project,
-                              warningsConfig,
-                              optionsForProject(target->project(), warningsConfig),
+                              warningsConfigForProject(target->project()),
+                              globalClangOptions(),
                               FilePath());
     Core::ProgressManager::addTask(task, tr("Generating Compilation DB"), "generate compilation db");
     m_generatorWatcher.setFuture(task);
@@ -121,8 +109,6 @@ bool ClangCodeModelPlugin::initialize(const QStringList &arguments, QString *err
 
     CppEditor::CppModelManager::instance()->activateClangCodeModel(&m_modelManagerSupportProvider);
 
-    addProjectPanelWidget();
-
     createCompilationDBButton();
 
     return true;
diff --git a/src/plugins/clangcodemodel/clangdclient.cpp b/src/plugins/clangcodemodel/clangdclient.cpp
index 921949ecc0..153aa84f48 100644
--- a/src/plugins/clangcodemodel/clangdclient.cpp
+++ b/src/plugins/clangcodemodel/clangdclient.cpp
@@ -1163,13 +1163,12 @@ ClangdClient::ClangdClient(Project *project, const Utils::FilePath &jsonDbDir)
         QJsonObject initOptions;
         const Utils::FilePath includeDir
                 = CppEditor::ClangdSettings(d->settings).clangdIncludePath();
-        const CppEditor::ClangDiagnosticConfig warningsConfig = warningsConfigForProject(nullptr);
         CppEditor::CompilerOptionsBuilder optionsBuilder = clangOptionsBuilder(
                     *CppEditor::CppModelManager::instance()->fallbackProjectPart(),
-                    warningsConfig, includeDir);
+                    warningsConfigForProject(nullptr), includeDir);
         const CppEditor::UsePrecompiledHeaders usePch = CppEditor::getPchUsage();
         const QJsonArray projectPartOptions = fullProjectPartOptions(
-                    optionsBuilder, optionsForProject(nullptr, warningsConfig));
+                    optionsBuilder, globalClangOptions());
         const QJsonArray clangOptions = clangOptionsForFile({}, optionsBuilder.projectPart(),
                                                             projectPartOptions, usePch);
         initOptions.insert("fallbackFlags", clangOptions);
@@ -1608,13 +1607,12 @@ void ClangdClient::updateParserConfig(const Utils::FilePath &filePath,
         return;
     QJsonObject cdbChanges;
     const Utils::FilePath includeDir = CppEditor::ClangdSettings(d->settings).clangdIncludePath();
-    const CppEditor::ClangDiagnosticConfig warningsConfig = warningsConfigForProject(project());
     CppEditor::CompilerOptionsBuilder optionsBuilder = clangOptionsBuilder(
-                *projectPart, warningsConfig, includeDir);
+                *projectPart, warningsConfigForProject(project()), includeDir);
     const CppEditor::ProjectFile file(filePath.toString(),
                                       CppEditor::ProjectFile::classify(filePath.toString()));
     const QJsonArray projectPartOptions = fullProjectPartOptions(
-                optionsBuilder, optionsForProject(project(), warningsConfig));
+                optionsBuilder, globalClangOptions());
     addToCompilationDb(cdbChanges, *projectPart, CppEditor::getPchUsage(), projectPartOptions,
                        filePath.parentDir(), file);
     QJsonObject settings;
diff --git a/src/plugins/clangcodemodel/clangeditordocumentprocessor.cpp b/src/plugins/clangcodemodel/clangeditordocumentprocessor.cpp
index 2d3eba9e62..bff5b85e23 100644
--- a/src/plugins/clangcodemodel/clangeditordocumentprocessor.cpp
+++ b/src/plugins/clangcodemodel/clangeditordocumentprocessor.cpp
@@ -25,7 +25,6 @@
 
 #include "clangeditordocumentprocessor.h"
 
-#include "clangprojectsettings.h"
 #include "clangdiagnostictooltipwidget.h"
 #include "clangfixitoperation.h"
 #include "clangmodelmanagersupport.h"
diff --git a/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp b/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
index 7966622e5a..1a25ef2a88 100644
--- a/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
+++ b/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
@@ -30,7 +30,6 @@
 #include "clangdquickfixfactory.h"
 #include "clangeditordocumentprocessor.h"
 #include "clangdlocatorfilters.h"
-#include "clangprojectsettings.h"
 #include "clangutils.h"
 
 #include <coreplugin/documentmanager.h>
@@ -137,19 +136,12 @@ ClangModelManagerSupport::ClangModelManagerSupport()
     });
 
     auto *sessionManager = ProjectExplorer::SessionManager::instance();
-    connect(sessionManager, &ProjectExplorer::SessionManager::projectAdded,
-            this, &ClangModelManagerSupport::onProjectAdded);
-    connect(sessionManager, &ProjectExplorer::SessionManager::aboutToRemoveProject,
-            this, &ClangModelManagerSupport::onAboutToRemoveProject);
     connect(sessionManager, &ProjectExplorer::SessionManager::projectRemoved,
             this, [this] { claimNonProjectSources(clientForProject(fallbackProject())); });
 
     CppEditor::ClangdSettings::setDefaultClangdPath(Core::ICore::clangdExecutable(CLANG_BINDIR));
     connect(&CppEditor::ClangdSettings::instance(), &CppEditor::ClangdSettings::changed,
             this, &ClangModelManagerSupport::onClangdSettingsChanged);
-    CppEditor::CppCodeModelSettings *settings = CppEditor::codeModelSettings();
-    connect(settings, &CppEditor::CppCodeModelSettings::clangDiagnosticConfigsInvalidated,
-            this, &ClangModelManagerSupport::onDiagnosticConfigsInvalidated);
 
     if (CppEditor::ClangdSettings::instance().useClangd())
         createClient(nullptr, {});
@@ -160,7 +152,6 @@ ClangModelManagerSupport::ClangModelManagerSupport()
 
 ClangModelManagerSupport::~ClangModelManagerSupport()
 {
-    QTC_CHECK(m_projectSettings.isEmpty());
     m_generatorSynchronizer.waitForFinished();
     m_instance = nullptr;
 }
@@ -427,11 +418,10 @@ void ClangModelManagerSupport::updateLanguageClient(
 
     });
     const Utils::FilePath includeDir = settings.clangdIncludePath();
-    const ClangDiagnosticConfig warningsConfig = warningsConfigForProject(project);
     auto future = Utils::runAsync(&Internal::generateCompilationDB, projectInfo, jsonDbDir,
                                   CompilationDbPurpose::CodeModel,
-                                  warningsConfig, optionsForProject(project, warningsConfig),
-                                  includeDir);
+                                  warningsConfigForProject(project),
+                                  globalClangOptions(), includeDir);
     generatorWatcher->setFuture(future);
     m_generatorSynchronizer.addFuture(future);
 }
@@ -670,42 +660,6 @@ static ClangEditorDocumentProcessors clangProcessors()
     return result;
 }
 
-static ClangEditorDocumentProcessors
-clangProcessorsWithProject(const ProjectExplorer::Project *project)
-{
-    return ::Utils::filtered(clangProcessors(), [project](ClangEditorDocumentProcessor *p) {
-        return p->hasProjectPart() && p->projectPart()->belongsToProject(project);
-    });
-}
-
-static void updateProcessors(const ClangEditorDocumentProcessors &processors)
-{
-    CppEditor::CppModelManager *modelManager = cppModelManager();
-    for (ClangEditorDocumentProcessor *processor : processors)
-        modelManager->cppEditorDocument(processor->filePath())->resetProcessor();
-    modelManager->updateCppEditorDocuments(/*projectsUpdated=*/ false);
-}
-
-void ClangModelManagerSupport::onProjectAdded(ProjectExplorer::Project *project)
-{
-    QTC_ASSERT(!m_projectSettings.value(project), return);
-
-    auto *settings = new Internal::ClangProjectSettings(project);
-    connect(settings, &Internal::ClangProjectSettings::changed, [project]() {
-        updateProcessors(clangProcessorsWithProject(project));
-    });
-
-    m_projectSettings.insert(project, settings);
-}
-
-void ClangModelManagerSupport::onAboutToRemoveProject(ProjectExplorer::Project *project)
-{
-    ClangProjectSettings * const settings = m_projectSettings.value(project);
-    QTC_ASSERT(settings, return);
-    m_projectSettings.remove(project);
-    delete settings;
-}
-
 void ClangModelManagerSupport::onProjectPartsUpdated(ProjectExplorer::Project *project)
 {
     QTC_ASSERT(project, return);
@@ -765,19 +719,6 @@ void ClangModelManagerSupport::onClangdSettingsChanged()
     }
 }
 
-static ClangEditorDocumentProcessors clangProcessorsWithDiagnosticConfig(
-    const QVector<::Utils::Id> &configIds)
-{
-    return ::Utils::filtered(clangProcessors(), [configIds](ClangEditorDocumentProcessor *p) {
-        return configIds.contains(p->diagnosticConfigId());
-    });
-}
-
-void ClangModelManagerSupport::onDiagnosticConfigsInvalidated(const QVector<::Utils::Id> &configIds)
-{
-    updateProcessors(clangProcessorsWithDiagnosticConfig(configIds));
-}
-
 static ClangEditorDocumentProcessors
 clangProcessorsWithProjectParts(const QStringList &projectPartIds)
 {
@@ -805,12 +746,6 @@ QString ClangModelManagerSupport::dummyUiHeaderOnDiskPath(const QString &filePat
     return m_uiHeaderOnDiskManager.mapPath(filePath);
 }
 
-ClangProjectSettings &ClangModelManagerSupport::projectSettings(
-    ProjectExplorer::Project *project) const
-{
-    return *m_projectSettings.value(project);
-}
-
 QString ClangModelManagerSupport::dummyUiHeaderOnDiskDirPath() const
 {
     return m_uiHeaderOnDiskManager.directoryPath();
diff --git a/src/plugins/clangcodemodel/clangmodelmanagersupport.h b/src/plugins/clangcodemodel/clangmodelmanagersupport.h
index 11baf781f8..4233f734b0 100644
--- a/src/plugins/clangcodemodel/clangmodelmanagersupport.h
+++ b/src/plugins/clangcodemodel/clangmodelmanagersupport.h
@@ -51,7 +51,6 @@ namespace ClangCodeModel {
 namespace Internal {
 
 class ClangdClient;
-class ClangProjectSettings;
 
 class ClangModelManagerSupport:
         public QObject,
@@ -74,8 +73,6 @@ public:
     QString dummyUiHeaderOnDiskDirPath() const;
     QString dummyUiHeaderOnDiskPath(const QString &filePath) const;
 
-    ClangProjectSettings &projectSettings(ProjectExplorer::Project *project) const;
-
     ClangdClient *clientForProject(const ProjectExplorer::Project *project) const;
     ClangdClient *clientForFile(const Utils::FilePath &file) const;
 
@@ -111,15 +108,10 @@ private:
                                         int lineNumber,
                                         QMenu *menu);
 
-    void onProjectAdded(ProjectExplorer::Project *project);
-    void onAboutToRemoveProject(ProjectExplorer::Project *project);
-
     void onProjectPartsUpdated(ProjectExplorer::Project *project);
     void onProjectPartsRemoved(const QStringList &projectPartIds);
     void onClangdSettingsChanged();
 
-    void onDiagnosticConfigsInvalidated(const QVector<::Utils::Id> &configIds);
-
     void reinitializeBackendDocuments(const QStringList &projectPartIds);
 
     void connectTextDocumentToTranslationUnit(TextEditor::TextDocument *textDocument);
@@ -134,7 +126,6 @@ private:
 
     UiHeaderOnDiskManager m_uiHeaderOnDiskManager;
 
-    QHash<ProjectExplorer::Project *, ClangProjectSettings *> m_projectSettings;
     Utils::FutureSynchronizer m_generatorSynchronizer;
     QList<QPointer<ClangdClient>> m_clientsToRestart;
 };
diff --git a/src/plugins/clangcodemodel/clangprojectsettings.cpp b/src/plugins/clangcodemodel/clangprojectsettings.cpp
deleted file mode 100644
index 0e7a98924b..0000000000
--- a/src/plugins/clangcodemodel/clangprojectsettings.cpp
+++ /dev/null
@@ -1,147 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** 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 "clangprojectsettings.h"
-
-#include <cppeditor/cppcodemodelsettings.h>
-#include <cppeditor/cpptoolsreuse.h>
-
-#include <utils/qtcassert.h>
-#include <utils/hostosinfo.h>
-
-#include <QDebug>
-
-namespace ClangCodeModel {
-namespace Internal {
-
-static QString useGlobalConfigKey()
-{ return QStringLiteral("ClangCodeModel.UseGlobalConfig"); }
-
-static QString warningConfigIdKey()
-{ return QStringLiteral("ClangCodeModel.WarningConfigId"); }
-
-static QString customCommandLineKey()
-{ return QLatin1String("ClangCodeModel.CustomCommandLineKey"); }
-
-static bool useGlobalConfigFromSettings(ProjectExplorer::Project *project)
-{
-    const QVariant useGlobalConfigVariant = project->namedSettings(useGlobalConfigKey());
-    return useGlobalConfigVariant.isValid() ? useGlobalConfigVariant.toBool() : true;
-}
-
-static Utils::Id warningConfigIdFromSettings(ProjectExplorer::Project *project)
-{
-    return Utils::Id::fromSetting(project->namedSettings(warningConfigIdKey()));
-}
-
-static QStringList customCommandLineFromSettings(ProjectExplorer::Project *project)
-{
-    QStringList options = project->namedSettings(customCommandLineKey()).toStringList();
-    if (options.empty())
-        options = ClangProjectSettings::globalCommandLineOptions();
-    return options;
-}
-
-ClangProjectSettings::ClangProjectSettings(ProjectExplorer::Project *project)
-    : m_project(project)
-{
-    load();
-
-    connect(project, &ProjectExplorer::Project::settingsLoaded,
-            this, &ClangProjectSettings::load);
-    connect(project, &ProjectExplorer::Project::aboutToSaveSettings,
-            this, &ClangProjectSettings::store);
-}
-
-Utils::Id ClangProjectSettings::warningConfigId() const
-{
-    const CppEditor::ClangDiagnosticConfigsModel model = CppEditor::diagnosticConfigsModel();
-    if (!model.hasConfigWithId(m_warningConfigId))
-        return CppEditor::codeModelSettings()->defaultClangDiagnosticConfigId();
-    return m_warningConfigId;
-}
-
-void ClangProjectSettings::setWarningConfigId(const Utils::Id &customConfigId)
-{
-    m_warningConfigId = customConfigId;
-}
-
-bool ClangProjectSettings::useGlobalConfig() const
-{
-    return m_useGlobalConfig;
-}
-
-void ClangProjectSettings::setUseGlobalConfig(bool useGlobalConfig)
-{
-    m_useGlobalConfig = useGlobalConfig;
-}
-
-QStringList ClangProjectSettings::commandLineOptions() const
-{
-    return m_useGlobalConfig ? globalCommandLineOptions()
-                             : m_customCommandLineOptions;
-}
-
-void ClangProjectSettings::setCommandLineOptions(const QStringList &options)
-{
-    QTC_ASSERT(!m_useGlobalConfig, qDebug()
-               << "setCommandLineOptions was called while using global project config");
-    m_customCommandLineOptions = options;
-}
-
-void ClangProjectSettings::load()
-{
-    setUseGlobalConfig(useGlobalConfigFromSettings(m_project));
-    setWarningConfigId(warningConfigIdFromSettings(m_project));
-    m_customCommandLineOptions = customCommandLineFromSettings(m_project);
-}
-
-void ClangProjectSettings::store()
-{
-    bool settingsChanged = false;
-    if (useGlobalConfig() != useGlobalConfigFromSettings(m_project))
-        settingsChanged = true;
-    if (warningConfigId() != warningConfigIdFromSettings(m_project))
-        settingsChanged = true;
-    if (commandLineOptions() != customCommandLineFromSettings(m_project))
-        settingsChanged = true;
-
-    m_project->setNamedSettings(useGlobalConfigKey(), useGlobalConfig());
-    m_project->setNamedSettings(warningConfigIdKey(), warningConfigId().toSetting());
-    m_project->setNamedSettings(customCommandLineKey(), m_customCommandLineOptions);
-
-    if (settingsChanged)
-        emit changed();
-}
-
-QStringList ClangProjectSettings::globalCommandLineOptions()
-{
-    if (Utils::HostOsInfo::isWindowsHost())
-        return {QLatin1String{GlobalWindowsCmdOptions}};
-    return {};
-}
-
-} // namespace Internal
-} // namespace ClangCodeModel
diff --git a/src/plugins/clangcodemodel/clangprojectsettings.h b/src/plugins/clangcodemodel/clangprojectsettings.h
deleted file mode 100644
index 511ac60875..0000000000
--- a/src/plugins/clangcodemodel/clangprojectsettings.h
+++ /dev/null
@@ -1,75 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** 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.
-**
-****************************************************************************/
-
-#pragma once
-
-#include <projectexplorer/project.h>
-
-#include <utils/id.h>
-
-#include <QObject>
-#include <QString>
-
-namespace ClangCodeModel {
-namespace Internal {
-
-class ClangProjectSettings: public QObject
-{
-    Q_OBJECT
-
-public:
-    constexpr static const char* DelayedTemplateParsing = "-fdelayed-template-parsing";
-    constexpr static const char* NoDelayedTemplateParsing = "-fno-delayed-template-parsing";
-    constexpr static const char* GlobalWindowsCmdOptions = NoDelayedTemplateParsing;
-
-    ClangProjectSettings(ProjectExplorer::Project *project);
-
-    bool useGlobalConfig() const;
-    void setUseGlobalConfig(bool useGlobalConfig);
-
-    ::Utils::Id warningConfigId() const;
-    void setWarningConfigId(const ::Utils::Id &warningConfigId);
-
-    QStringList commandLineOptions() const;
-    void setCommandLineOptions(const QStringList &options);
-
-    void load();
-    void store();
-
-    static QStringList globalCommandLineOptions();
-
-signals:
-    void changed();
-
-private:
-    ProjectExplorer::Project *m_project;
-    bool m_useGlobalConfig = true;
-    ::Utils::Id m_warningConfigId;
-
-    QStringList m_customCommandLineOptions;
-};
-
-} // namespace Internal
-} // namespace ClangCodeModel
diff --git a/src/plugins/clangcodemodel/clangprojectsettingswidget.cpp b/src/plugins/clangcodemodel/clangprojectsettingswidget.cpp
deleted file mode 100644
index 38521163d2..0000000000
--- a/src/plugins/clangcodemodel/clangprojectsettingswidget.cpp
+++ /dev/null
@@ -1,159 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** 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 "clangprojectsettingswidget.h"
-
-#include "clangmodelmanagersupport.h"
-#include "clangprojectsettings.h"
-
-#include <coreplugin/icore.h>
-
-#include <cppeditor/clangdiagnosticconfig.h>
-#include <cppeditor/clangdiagnosticconfigswidget.h>
-#include <cppeditor/cppeditorconstants.h>
-#include <cppeditor/cppcodemodelsettings.h>
-#include <cppeditor/cpptoolsreuse.h>
-
-#include <utils/hostosinfo.h>
-
-namespace ClangCodeModel {
-namespace Internal {
-
-static Utils::Id configIdForProject(ClangProjectSettings &projectSettings)
-{
-    if (projectSettings.useGlobalConfig())
-        return CppEditor::codeModelSettings()->clangDiagnosticConfigId();
-    return projectSettings.warningConfigId();
-}
-
-ClangProjectSettingsWidget::ClangProjectSettingsWidget(ProjectExplorer::Project *project)
-    : m_projectSettings(ClangModelManagerSupport::instance()->projectSettings(project))
-{
-    m_ui.setupUi(this);
-
-    using namespace CppEditor;
-
-    m_ui.delayedTemplateParseCheckBox->setVisible(Utils::HostOsInfo::isWindowsHost());
-
-    // Links
-    connect(m_ui.gotoGlobalSettingsLabel, &QLabel::linkActivated, [](const QString &) {
-        Core::ICore::showOptionsDialog(CppEditor::Constants::CPP_CODE_MODEL_SETTINGS_ID);
-    });
-
-    connect(m_ui.clangDiagnosticConfigsSelectionWidget,
-            &ClangDiagnosticConfigsSelectionWidget::changed,
-            this,
-            [this]() {
-                // Save project's config id
-                const Utils::Id currentConfigId = m_ui.clangDiagnosticConfigsSelectionWidget
-                                                     ->currentConfigId();
-                m_projectSettings.setWarningConfigId(currentConfigId);
-
-                // Save global custom configs
-                const ClangDiagnosticConfigs configs = m_ui.clangDiagnosticConfigsSelectionWidget
-                                                           ->customConfigs();
-                CppEditor::codeModelSettings()->setClangCustomDiagnosticConfigs(configs);
-                CppEditor::codeModelSettings()->toSettings(Core::ICore::settings());
-            });
-
-    connect(m_ui.delayedTemplateParseCheckBox, &QCheckBox::toggled,
-            this, &ClangProjectSettingsWidget::onDelayedTemplateParseClicked);
-    connect(m_ui.globalOrCustomComboBox,
-            QOverload<int>::of(&QComboBox::currentIndexChanged),
-            this, &ClangProjectSettingsWidget::onGlobalCustomChanged);
-    connect(project, &ProjectExplorer::Project::aboutToSaveSettings,
-            this, &ClangProjectSettingsWidget::onAboutToSaveProjectSettings);
-
-    connect(&m_projectSettings, &ClangProjectSettings::changed,
-            this, &ClangProjectSettingsWidget::syncWidgets);
-    connect(CppEditor::codeModelSettings(), &CppEditor::CppCodeModelSettings::changed,
-            this, &ClangProjectSettingsWidget::syncOtherWidgetsToComboBox);
-
-    syncWidgets();
-}
-
-void ClangProjectSettingsWidget::onDelayedTemplateParseClicked(bool checked)
-{
-    // Don't save it when we reset the global config in code
-    if (m_projectSettings.useGlobalConfig())
-        return;
-
-    const QLatin1String extraFlag{checked ? ClangProjectSettings::DelayedTemplateParsing
-                                          : ClangProjectSettings::NoDelayedTemplateParsing};
-    QStringList options = m_projectSettings.commandLineOptions();
-    options.removeAll(QLatin1String{ClangProjectSettings::DelayedTemplateParsing});
-    options.removeAll(QLatin1String{ClangProjectSettings::NoDelayedTemplateParsing});
-    options.append(extraFlag);
-    m_projectSettings.setCommandLineOptions(options);
-}
-
-void ClangProjectSettingsWidget::onGlobalCustomChanged(int index)
-{
-    m_projectSettings.setUseGlobalConfig(index == 0 ? true : false);
-    syncOtherWidgetsToComboBox();
-}
-
-void ClangProjectSettingsWidget::onAboutToSaveProjectSettings()
-{
-    CppEditor::codeModelSettings()->toSettings(Core::ICore::settings());
-}
-
-void ClangProjectSettingsWidget::syncWidgets()
-{
-    syncGlobalCustomComboBox();
-    syncOtherWidgetsToComboBox();
-}
-
-void ClangProjectSettingsWidget::syncGlobalCustomComboBox()
-{
-    m_ui.globalOrCustomComboBox->setCurrentIndex(m_projectSettings.useGlobalConfig() ? 0 : 1);
-}
-
-void ClangProjectSettingsWidget::syncOtherWidgetsToComboBox()
-{
-    const QStringList options = m_projectSettings.commandLineOptions();
-    m_ui.delayedTemplateParseCheckBox->setChecked(
-        options.contains(QLatin1String{ClangProjectSettings::DelayedTemplateParsing}));
-
-    const bool isCustom = !m_projectSettings.useGlobalConfig();
-    m_ui.delayedTemplateParseCheckBox->setEnabled(isCustom);
-
-    for (int i = 0; i < m_ui.clangDiagnosticConfigsSelectionWidget->layout()->count(); ++i) {
-        QWidget *widget = m_ui.clangDiagnosticConfigsSelectionWidget->layout()->itemAt(i)->widget();
-        if (widget)
-            widget->setEnabled(isCustom);
-    }
-
-    m_ui.clangDiagnosticConfigsSelectionWidget
-        ->refresh(CppEditor::diagnosticConfigsModel(),
-                  configIdForProject(m_projectSettings),
-                  [](const CppEditor::ClangDiagnosticConfigs &configs,
-                     const Utils::Id &configToSelect) {
-                      return new CppEditor::ClangDiagnosticConfigsWidget(configs, configToSelect);
-                  });
-}
-
-} // namespace Internal
-} // namespace ClangCodeModel
diff --git a/src/plugins/clangcodemodel/clangprojectsettingswidget.h b/src/plugins/clangcodemodel/clangprojectsettingswidget.h
deleted file mode 100644
index c1127ee6cb..0000000000
--- a/src/plugins/clangcodemodel/clangprojectsettingswidget.h
+++ /dev/null
@@ -1,61 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2016 The Qt Company Ltd.
-** 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.
-**
-****************************************************************************/
-
-#pragma once
-
-#include "ui_clangprojectsettingswidget.h"
-
-#include "clangprojectsettings.h"
-
-#include <QPointer>
-
-namespace ProjectExplorer { class Project; }
-
-namespace ClangCodeModel {
-namespace Internal {
-
-class ClangProjectSettingsWidget: public QWidget
-{
-    Q_OBJECT
-
-public:
-    explicit ClangProjectSettingsWidget(ProjectExplorer::Project *project);
-
-private:
-    void onDelayedTemplateParseClicked(bool);
-    void onGlobalCustomChanged(int index);
-    void onAboutToSaveProjectSettings();
-
-    void syncWidgets();
-    void syncGlobalCustomComboBox();
-    void syncOtherWidgetsToComboBox();
-
-private:
-    Ui::ClangProjectSettingsWidget m_ui;
-    ClangProjectSettings &m_projectSettings;
-};
-
-} // namespace Internal
-} // namespace ClangCodeModel
diff --git a/src/plugins/clangcodemodel/clangprojectsettingswidget.ui b/src/plugins/clangcodemodel/clangprojectsettingswidget.ui
deleted file mode 100644
index d21ac3c731..0000000000
--- a/src/plugins/clangcodemodel/clangprojectsettingswidget.ui
+++ /dev/null
@@ -1,98 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<ui version="4.0">
- <class>ClangCodeModel::Internal::ClangProjectSettingsWidget</class>
- <widget class="QWidget" name="ClangCodeModel::Internal::ClangProjectSettingsWidget">
-  <property name="enabled">
-   <bool>true</bool>
-  </property>
-  <property name="geometry">
-   <rect>
-    <x>0</x>
-    <y>0</y>
-    <width>814</width>
-    <height>330</height>
-   </rect>
-  </property>
-  <layout class="QVBoxLayout" name="verticalLayout">
-   <property name="leftMargin">
-    <number>0</number>
-   </property>
-   <property name="topMargin">
-    <number>0</number>
-   </property>
-   <property name="rightMargin">
-    <number>0</number>
-   </property>
-   <property name="bottomMargin">
-    <number>0</number>
-   </property>
-   <item>
-    <layout class="QHBoxLayout" name="horizontalLayout">
-     <item>
-      <widget class="QComboBox" name="globalOrCustomComboBox">
-       <property name="sizePolicy">
-        <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
-         <horstretch>0</horstretch>
-         <verstretch>0</verstretch>
-        </sizepolicy>
-       </property>
-       <item>
-        <property name="text">
-         <string>Use Global Settings</string>
-        </property>
-       </item>
-       <item>
-        <property name="text">
-         <string>Use Customized Settings</string>
-        </property>
-       </item>
-      </widget>
-     </item>
-     <item>
-      <widget class="QLabel" name="gotoGlobalSettingsLabel">
-       <property name="text">
-        <string>&lt;a href=&quot;target&quot;&gt;Open Global Settings&lt;/a&gt;</string>
-       </property>
-      </widget>
-     </item>
-    </layout>
-   </item>
-   <item>
-    <widget class="QCheckBox" name="delayedTemplateParseCheckBox">
-     <property name="toolTip">
-      <string>Parse templates in a MSVC-compliant way. This helps to parse headers for example from Active Template Library (ATL) or Windows Runtime Library (WRL).
-However, using the relaxed and extended rules means also that no highlighting/completion can be provided within template functions.</string>
-     </property>
-     <property name="text">
-      <string>Enable MSVC-compliant template parsing</string>
-     </property>
-    </widget>
-   </item>
-   <item>
-    <widget class="CppEditor::ClangDiagnosticConfigsSelectionWidget" name="clangDiagnosticConfigsSelectionWidget" native="true"/>
-   </item>
-   <item>
-    <spacer name="verticalSpacer">
-     <property name="orientation">
-      <enum>Qt::Vertical</enum>
-     </property>
-     <property name="sizeHint" stdset="0">
-      <size>
-       <width>20</width>
-       <height>40</height>
-      </size>
-     </property>
-    </spacer>
-   </item>
-  </layout>
- </widget>
- <customwidgets>
-  <customwidget>
-   <class>CppEditor::ClangDiagnosticConfigsSelectionWidget</class>
-   <extends>QWidget</extends>
-   <header>cppeditor/clangdiagnosticconfigsselectionwidget.h</header>
-  </customwidget>
- </customwidgets>
- <resources/>
- <connections/>
-</ui>
diff --git a/src/plugins/clangcodemodel/clangtextmark.cpp b/src/plugins/clangcodemodel/clangtextmark.cpp
index c3ead0aa4c..6120e90e91 100644
--- a/src/plugins/clangcodemodel/clangtextmark.cpp
+++ b/src/plugins/clangcodemodel/clangtextmark.cpp
@@ -30,7 +30,6 @@
 #include "clangdiagnostictooltipwidget.h"
 #include "clangeditordocumentprocessor.h"
 #include "clangmodelmanagersupport.h"
-#include "clangprojectsettings.h"
 #include "clangutils.h"
 
 #include <coreplugin/icore.h>
@@ -113,33 +112,18 @@ void disableDiagnosticInConfig(ClangDiagnosticConfig &config, const ClangDiagnos
     }
 }
 
-ClangDiagnosticConfig diagnosticConfig(const ClangProjectSettings &projectSettings,
-                                       const CppCodeModelSettings &globalSettings)
+ClangDiagnosticConfig diagnosticConfig()
 {
     Project *project = projectForCurrentEditor();
     QTC_ASSERT(project, return {});
-
-    // Get config id
-    Id currentConfigId = projectSettings.warningConfigId();
-    if (projectSettings.useGlobalConfig())
-        currentConfigId = globalSettings.clangDiagnosticConfigId();
-
-    // Get config
-    ClangDiagnosticConfigsModel configsModel = CppEditor::diagnosticConfigsModel();
-    QTC_ASSERT(configsModel.hasConfigWithId(currentConfigId), return {});
-    return configsModel.configWithId(currentConfigId);
+    return warningsConfigForProject(project);
 }
 
 bool isDiagnosticConfigChangable(Project *project, const ClangDiagnostic &diagnostic)
 {
     if (!project)
         return false;
-
-    ClangProjectSettings &projectSettings = ClangModelManagerSupport::instance()->projectSettings(
-        project);
-    const CppCodeModelSettings *globalSettings = codeModelSettings();
-    const ClangDiagnosticConfig config = diagnosticConfig(projectSettings, *globalSettings);
-
+    const ClangDiagnosticConfig config = diagnosticConfig();
     if (config.clangTidyMode() == ClangDiagnosticConfig::TidyMode::UseConfigFile
         && diagnosticType(diagnostic) == DiagnosticType::Tidy) {
         return false;
@@ -152,13 +136,8 @@ void disableDiagnosticInCurrentProjectConfig(const ClangDiagnostic &diagnostic)
     Project *project = projectForCurrentEditor();
     QTC_ASSERT(project, return );
 
-    // Get settings
-    ClangProjectSettings &projectSettings = ClangModelManagerSupport::instance()->projectSettings(
-        project);
-    CppCodeModelSettings *globalSettings = codeModelSettings();
-
     // Get config
-    ClangDiagnosticConfig config = diagnosticConfig(projectSettings, *globalSettings);
+    ClangDiagnosticConfig config = diagnosticConfig();
     ClangDiagnosticConfigsModel configsModel = CppEditor::diagnosticConfigsModel();
 
     // Create copy if needed
@@ -174,14 +153,13 @@ void disableDiagnosticInCurrentProjectConfig(const ClangDiagnostic &diagnostic)
     configsModel.appendOrUpdate(config);
 
     // Set global settings
-    globalSettings->setClangCustomDiagnosticConfigs(configsModel.customConfigs());
-    globalSettings->toSettings(Core::ICore::settings());
+    ClangdSettings::setCustomDiagnosticConfigs(configsModel.customConfigs());
 
     // Set project settings
-    if (projectSettings.useGlobalConfig())
-        projectSettings.setUseGlobalConfig(false);
-    projectSettings.setWarningConfigId(config.id());
-    projectSettings.store();
+    ClangdProjectSettings projectSettings(project);
+    if (projectSettings.useGlobalSettings())
+        projectSettings.setUseGlobalSettings(false);
+    projectSettings.setDiagnosticConfigId(config.id());
 
     // Notify the user about changed project specific settings
     const QString text
diff --git a/src/plugins/clangcodemodel/clangutils.cpp b/src/plugins/clangcodemodel/clangutils.cpp
index 664442cced..d2d5e69070 100644
--- a/src/plugins/clangcodemodel/clangutils.cpp
+++ b/src/plugins/clangcodemodel/clangutils.cpp
@@ -25,13 +25,12 @@
 
 #include "clangutils.h"
 
-#include "clangeditordocumentprocessor.h"
 #include "clangmodelmanagersupport.h"
-#include "clangprojectsettings.h"
 
 #include <coreplugin/icore.h>
 #include <coreplugin/idocument.h>
 #include <cppeditor/baseeditordocumentparser.h>
+#include <cppeditor/clangdiagnosticconfigsmodel.h>
 #include <cppeditor/compileroptionsbuilder.h>
 #include <cppeditor/cppcodemodelsettings.h>
 #include <cppeditor/cppmodelmanager.h>
@@ -276,14 +275,6 @@ QString DiagnosticTextInfo::clazyCheckName(const QString &option)
 }
 
 
-namespace {
-static ClangProjectSettings &getProjectSettings(ProjectExplorer::Project *project)
-{
-    QTC_CHECK(project);
-    return ClangModelManagerSupport::instance()->projectSettings(project);
-}
-} // namespace
-
 QJsonArray clangOptionsForFile(const ProjectFile &file, const ProjectPart &projectPart,
                                const QJsonArray &generalOptions, UsePrecompiledHeaders usePch)
 {
@@ -308,30 +299,12 @@ QJsonArray clangOptionsForFile(const ProjectFile &file, const ProjectPart &proje
 
 ClangDiagnosticConfig warningsConfigForProject(Project *project)
 {
-    if (project) {
-        ClangProjectSettings &projectSettings = ClangModelManagerSupport::instance()
-                ->projectSettings(project);
-        if (!projectSettings.useGlobalConfig()) {
-            const Utils::Id warningConfigId = projectSettings.warningConfigId();
-            const CppEditor::ClangDiagnosticConfigsModel configsModel
-                    = CppEditor::diagnosticConfigsModel();
-            if (configsModel.hasConfigWithId(warningConfigId))
-                return configsModel.configWithId(warningConfigId);
-        }
-    }
-    return CppEditor::codeModelSettings()->clangDiagnosticConfig();
+    return ClangdSettings(ClangdProjectSettings(project).settings()).diagnosticConfig();
 }
 
-const QStringList optionsForProject(ProjectExplorer::Project *project,
-                                    const ClangDiagnosticConfig &warningsConfig)
+const QStringList globalClangOptions()
 {
-    QStringList options = ClangDiagnosticConfigsModel::globalDiagnosticOptions();
-    if (!warningsConfig.useBuildSystemWarnings()) {
-        options += project
-                ? getProjectSettings(project).commandLineOptions()
-                : ClangProjectSettings::globalCommandLineOptions();
-    }
-    return options;
+    return ClangDiagnosticConfigsModel::globalDiagnosticOptions();
 }
 
 // 7.3.3: using typename(opt) nested-name-specifier unqualified-id ;
diff --git a/src/plugins/clangcodemodel/clangutils.h b/src/plugins/clangcodemodel/clangutils.h
index 71fa091971..4eef4b90dd 100644
--- a/src/plugins/clangcodemodel/clangutils.h
+++ b/src/plugins/clangcodemodel/clangutils.h
@@ -52,8 +52,7 @@ namespace ClangCodeModel {
 namespace Internal {
 
 CppEditor::ClangDiagnosticConfig warningsConfigForProject(ProjectExplorer::Project *project);
-const QStringList optionsForProject(ProjectExplorer::Project *project,
-                                    const CppEditor::ClangDiagnosticConfig &warningsConfig);
+const QStringList globalClangOptions();
 
 CppEditor::CompilerOptionsBuilder clangOptionsBuilder(
         const CppEditor::ProjectPart &projectPart,
diff --git a/src/plugins/clangtools/clangtoolssettings.cpp b/src/plugins/clangtools/clangtoolssettings.cpp
index ee099ddfae..7578b25278 100644
--- a/src/plugins/clangtools/clangtoolssettings.cpp
+++ b/src/plugins/clangtools/clangtoolssettings.cpp
@@ -30,6 +30,7 @@
 
 #include <coreplugin/icore.h>
 #include <cppeditor/clangdiagnosticconfig.h>
+#include <cppeditor/clangdiagnosticconfigsmodel.h>
 #include <cppeditor/cppcodemodelsettings.h>
 #include <cppeditor/cpptoolsreuse.h>
 
@@ -123,7 +124,7 @@ static QVariantMap convertToMapFromVersionBefore410(QSettings *s)
 
 ClangDiagnosticConfigs importDiagnosticConfigsFromCodeModel()
 {
-    const ClangDiagnosticConfigs configs = codeModelSettings()->clangCustomDiagnosticConfigs();
+    const ClangDiagnosticConfigs configs = ClangdSettings::instance().customDiagnosticConfigs();
 
     ClangDiagnosticConfigs tidyClazyConfigs;
     ClangDiagnosticConfigs clangOnlyConfigs;
@@ -132,12 +133,6 @@ ClangDiagnosticConfigs importDiagnosticConfigsFromCodeModel()
               return !config.clazyChecks().isEmpty()
                   || (!config.clangTidyChecks().isEmpty() && config.clangTidyChecks() != "-*");
           });
-
-    if (!tidyClazyConfigs.isEmpty()) {
-        codeModelSettings()->setClangCustomDiagnosticConfigs(clangOnlyConfigs);
-        codeModelSettings()->toSettings(Core::ICore::settings());
-    }
-
     return tidyClazyConfigs;
 }
 
diff --git a/src/plugins/cppeditor/clangdiagnosticconfigsmodel.cpp b/src/plugins/cppeditor/clangdiagnosticconfigsmodel.cpp
index c3794099b5..ead0ef97c9 100644
--- a/src/plugins/cppeditor/clangdiagnosticconfigsmodel.cpp
+++ b/src/plugins/cppeditor/clangdiagnosticconfigsmodel.cpp
@@ -87,23 +87,6 @@ const ClangDiagnosticConfig &ClangDiagnosticConfigsModel::configWithId(const Uti
     return m_diagnosticConfigs.at(indexOfConfig(id));
 }
 
-QVector<Utils::Id> ClangDiagnosticConfigsModel::changedOrRemovedConfigs(
-    const ClangDiagnosticConfigs &oldConfigs, const ClangDiagnosticConfigs &newConfigs)
-{
-    ClangDiagnosticConfigsModel newConfigsModel(newConfigs);
-    QVector<Utils::Id> changedConfigs;
-
-    for (const ClangDiagnosticConfig &old: oldConfigs) {
-        const int i = newConfigsModel.indexOfConfig(old.id());
-        if (i == -1)
-            changedConfigs.append(old.id()); // Removed
-        else if (newConfigsModel.allConfigs().value(i) != old)
-            changedConfigs.append(old.id()); // Changed
-    }
-
-    return changedConfigs;
-}
-
 ClangDiagnosticConfig ClangDiagnosticConfigsModel::createCustomConfig(
     const ClangDiagnosticConfig &baseConfig, const QString &displayName)
 {
diff --git a/src/plugins/cppeditor/clangdiagnosticconfigsmodel.h b/src/plugins/cppeditor/clangdiagnosticconfigsmodel.h
index edc4b164d3..d4b2584d46 100644
--- a/src/plugins/cppeditor/clangdiagnosticconfigsmodel.h
+++ b/src/plugins/cppeditor/clangdiagnosticconfigsmodel.h
@@ -52,8 +52,6 @@ public:
     const ClangDiagnosticConfig &configWithId(const Utils::Id &id) const;
     int indexOfConfig(const Utils::Id &id) const;
 
-    static QVector<Utils::Id> changedOrRemovedConfigs(const ClangDiagnosticConfigs &oldConfigs,
-                                                     const ClangDiagnosticConfigs &newConfigs);
     static ClangDiagnosticConfig createCustomConfig(const ClangDiagnosticConfig &baseConfig,
                                                     const QString &displayName);
     static QStringList globalDiagnosticOptions();
diff --git a/src/plugins/cppeditor/clangdiagnosticconfigsselectionwidget.cpp b/src/plugins/cppeditor/clangdiagnosticconfigsselectionwidget.cpp
index a1de9d125d..25d438f795 100644
--- a/src/plugins/cppeditor/clangdiagnosticconfigsselectionwidget.cpp
+++ b/src/plugins/cppeditor/clangdiagnosticconfigsselectionwidget.cpp
@@ -33,6 +33,7 @@
 
 #include <QDialog>
 #include <QDialogButtonBox>
+#include <QFormLayout>
 #include <QHBoxLayout>
 #include <QLabel>
 #include <QPushButton>
@@ -41,20 +42,15 @@ namespace CppEditor {
 
 ClangDiagnosticConfigsSelectionWidget::ClangDiagnosticConfigsSelectionWidget(QWidget *parent)
     : QWidget(parent)
-    , m_label(new QLabel(tr("Diagnostic configuration:")))
-    , m_button(new QPushButton)
 {
-    auto *layout = new QHBoxLayout(this);
-    layout->setContentsMargins(0, 0, 0, 0);
-    setLayout(layout);
-    layout->addWidget(m_label);
-    layout->addWidget(m_button, 1);
-    layout->addStretch();
+    setUpUi(true);
+}
 
-    connect(m_button,
-            &QPushButton::clicked,
-            this,
-            &ClangDiagnosticConfigsSelectionWidget::onButtonClicked);
+ClangDiagnosticConfigsSelectionWidget::ClangDiagnosticConfigsSelectionWidget(
+        QFormLayout *parentLayout)
+{
+    setUpUi(false);
+    parentLayout->addRow(label(), this);
 }
 
 void ClangDiagnosticConfigsSelectionWidget::refresh(const ClangDiagnosticConfigsModel &model,
@@ -79,6 +75,25 @@ ClangDiagnosticConfigs ClangDiagnosticConfigsSelectionWidget::customConfigs() co
     return m_diagnosticConfigsModel.customConfigs();
 }
 
+QString ClangDiagnosticConfigsSelectionWidget::label() const
+{
+    return tr("Diagnostic configuration:");
+}
+
+void ClangDiagnosticConfigsSelectionWidget::setUpUi(bool withLabel)
+{
+    m_button = new QPushButton;
+    const auto layout = new QHBoxLayout(this);
+    layout->setContentsMargins(0, 0, 0, 0);
+    if (withLabel)
+        layout->addWidget(new QLabel(label()));
+    layout->addWidget(m_button);
+    layout->addStretch();
+
+    connect(m_button, &QPushButton::clicked,
+            this, &ClangDiagnosticConfigsSelectionWidget::onButtonClicked);
+}
+
 void ClangDiagnosticConfigsSelectionWidget::onButtonClicked()
 {
     ClangDiagnosticConfigsWidget *widget = m_createEditWidget(m_diagnosticConfigsModel.allConfigs(),
diff --git a/src/plugins/cppeditor/clangdiagnosticconfigsselectionwidget.h b/src/plugins/cppeditor/clangdiagnosticconfigsselectionwidget.h
index 10fdd76039..e18006c890 100644
--- a/src/plugins/cppeditor/clangdiagnosticconfigsselectionwidget.h
+++ b/src/plugins/cppeditor/clangdiagnosticconfigsselectionwidget.h
@@ -34,7 +34,7 @@
 #include <functional>
 
 QT_BEGIN_NAMESPACE
-class QLabel;
+class QFormLayout;
 class QPushButton;
 QT_END_NAMESPACE
 
@@ -48,6 +48,7 @@ class CPPEDITOR_EXPORT ClangDiagnosticConfigsSelectionWidget : public QWidget
 
 public:
     explicit ClangDiagnosticConfigsSelectionWidget(QWidget *parent = nullptr);
+    explicit ClangDiagnosticConfigsSelectionWidget(QFormLayout *parentLayout);
 
     using CreateEditWidget
         = std::function<ClangDiagnosticConfigsWidget *(const ClangDiagnosticConfigs &configs,
@@ -64,13 +65,14 @@ signals:
     void changed();
 
 private:
+    QString label() const;
+    void setUpUi(bool withLabel);
     void onButtonClicked();
 
     ClangDiagnosticConfigsModel m_diagnosticConfigsModel;
     Utils::Id m_currentConfigId;
     bool m_showTidyClazyUi = true;
 
-    QLabel *m_label = nullptr;
     QPushButton *m_button = nullptr;
 
     CreateEditWidget m_createEditWidget;
diff --git a/src/plugins/cppeditor/clangdiagnosticconfigswidget.cpp b/src/plugins/cppeditor/clangdiagnosticconfigswidget.cpp
index bf70ba4bb6..7e17171d5d 100644
--- a/src/plugins/cppeditor/clangdiagnosticconfigswidget.cpp
+++ b/src/plugins/cppeditor/clangdiagnosticconfigswidget.cpp
@@ -25,7 +25,7 @@
 
 #include "clangdiagnosticconfigswidget.h"
 
-#include "cppcodemodelsettings.h"
+#include "clangdiagnosticconfigsmodel.h"
 #include "ui_clangdiagnosticconfigswidget.h"
 #include "ui_clangbasechecks.h"
 
diff --git a/src/plugins/cppeditor/cppcodemodelsettings.cpp b/src/plugins/cppeditor/cppcodemodelsettings.cpp
index f30469abfe..f33cc7bbd5 100644
--- a/src/plugins/cppeditor/cppcodemodelsettings.cpp
+++ b/src/plugins/cppeditor/cppcodemodelsettings.cpp
@@ -54,9 +54,6 @@ static Id initialClangDiagnosticConfigId()
 static CppCodeModelSettings::PCHUsage initialPchUsage()
 { return CppCodeModelSettings::PchUse_BuildSystem; }
 
-static QString clangDiagnosticConfigKey()
-{ return QStringLiteral("ClangDiagnosticConfig"); }
-
 static QString enableLowerClazyLevelsKey()
 { return QLatin1String("enableLowerClazyLevels"); }
 
@@ -83,6 +80,7 @@ static QString clangdSizeThresholdEnabledKey() { return QLatin1String("ClangdSiz
 static QString clangdSizeThresholdKey() { return QLatin1String("ClangdSizeThreshold"); }
 static QString clangdUseGlobalSettingsKey() { return QLatin1String("useGlobalSettings"); }
 static QString sessionsWithOneClangdKey() { return QLatin1String("SessionsWithOneClangd"); }
+static QString diagnosticConfigIdKey() { return QLatin1String("diagnosticConfigId"); }
 
 static FilePath g_defaultClangdFilePath;
 static FilePath fallbackClangdFilePath()
@@ -92,91 +90,10 @@ static FilePath fallbackClangdFilePath()
     return "clangd";
 }
 
-static Id clangDiagnosticConfigIdFromSettings(QSettings *s)
-{
-    QTC_ASSERT(s->group() == QLatin1String(Constants::CPPEDITOR_SETTINGSGROUP), return Id());
-
-    return Id::fromSetting(
-        s->value(clangDiagnosticConfigKey(), initialClangDiagnosticConfigId().toSetting()));
-}
-
-// Removed since Qt Creator 4.11
-static ClangDiagnosticConfigs removedBuiltinConfigs()
-{
-    ClangDiagnosticConfigs configs;
-
-    // Pedantic
-    ClangDiagnosticConfig config;
-    config.setId("Builtin.Pedantic");
-    config.setDisplayName(QCoreApplication::translate("ClangDiagnosticConfigsModel",
-                                                      "Pedantic checks"));
-    config.setIsReadOnly(true);
-    config.setClangOptions(QStringList{QStringLiteral("-Wpedantic")});
-    config.setClangTidyMode(ClangDiagnosticConfig::TidyMode::UseCustomChecks);
-    config.setClazyMode(ClangDiagnosticConfig::ClazyMode::UseCustomChecks);
-    configs << config;
-
-    // Everything with exceptions
-    config = ClangDiagnosticConfig();
-    config.setId("Builtin.EverythingWithExceptions");
-    config.setDisplayName(QCoreApplication::translate(
-                              "ClangDiagnosticConfigsModel",
-                              "Checks for almost everything"));
-    config.setIsReadOnly(true);
-    config.setClangOptions(QStringList{
-        QStringLiteral("-Weverything"),
-        QStringLiteral("-Wno-c++98-compat"),
-        QStringLiteral("-Wno-c++98-compat-pedantic"),
-        QStringLiteral("-Wno-unused-macros"),
-        QStringLiteral("-Wno-newline-eof"),
-        QStringLiteral("-Wno-exit-time-destructors"),
-        QStringLiteral("-Wno-global-constructors"),
-        QStringLiteral("-Wno-gnu-zero-variadic-macro-arguments"),
-        QStringLiteral("-Wno-documentation"),
-        QStringLiteral("-Wno-shadow"),
-        QStringLiteral("-Wno-switch-enum"),
-        QStringLiteral("-Wno-missing-prototypes"), // Not optimal for C projects.
-        QStringLiteral("-Wno-used-but-marked-unused"), // e.g. QTest::qWait
-    });
-    config.setClangTidyMode(ClangDiagnosticConfig::TidyMode::UseCustomChecks);
-    config.setClazyMode(ClangDiagnosticConfig::ClazyMode::UseCustomChecks);
-    configs << config;
-
-    return configs;
-}
-
-static ClangDiagnosticConfig convertToCustomConfig(const Id &id)
-{
-    const ClangDiagnosticConfig config
-        = findOrDefault(removedBuiltinConfigs(), [id](const ClangDiagnosticConfig &config) {
-              return config.id() == id;
-          });
-    return ClangDiagnosticConfigsModel::createCustomConfig(config, config.displayName());
-}
-
 void CppCodeModelSettings::fromSettings(QSettings *s)
 {
     s->beginGroup(QLatin1String(Constants::CPPEDITOR_SETTINGSGROUP));
 
-    setClangCustomDiagnosticConfigs(diagnosticConfigsFromSettings(s));
-    setClangDiagnosticConfigId(clangDiagnosticConfigIdFromSettings(s));
-
-    // Qt Creator 4.11 removes some built-in configs.
-    bool write = false;
-    const Id id = m_clangDiagnosticConfigId;
-    if (id == "Builtin.Pedantic" || id == "Builtin.EverythingWithExceptions") {
-        // If one of them was used, continue to use it, but convert it to a custom config.
-        const ClangDiagnosticConfig customConfig = convertToCustomConfig(id);
-        m_clangCustomDiagnosticConfigs.append(customConfig);
-        m_clangDiagnosticConfigId = customConfig.id();
-        write = true;
-    }
-
-    // Before Qt Creator 4.8, inconsistent settings might have been written.
-    const ClangDiagnosticConfigsModel model = diagnosticConfigsModel(m_clangCustomDiagnosticConfigs);
-    if (!model.hasConfigWithId(m_clangDiagnosticConfigId))
-        setClangDiagnosticConfigId(initialClangDiagnosticConfigId());
-
     setEnableLowerClazyLevels(s->value(enableLowerClazyLevelsKey(), true).toBool());
 
     const QVariant pchUsageVariant = s->value(pchUsageKey(), initialPchUsage());
@@ -194,21 +111,13 @@ void CppCodeModelSettings::fromSettings(QSettings *s)
 
     s->endGroup();
 
-    if (write)
-        toSettings(s);
-
     emit changed();
 }
 
 void CppCodeModelSettings::toSettings(QSettings *s)
 {
     s->beginGroup(QLatin1String(Constants::CPPEDITOR_SETTINGSGROUP));
-    const ClangDiagnosticConfigs previousConfigs = diagnosticConfigsFromSettings(s);
-    const Id previousConfigId = clangDiagnosticConfigIdFromSettings(s);
-
-    diagnosticConfigsToSettings(s, m_clangCustomDiagnosticConfigs);
 
-    s->setValue(clangDiagnosticConfigKey(), clangDiagnosticConfigId().toSetting());
     s->setValue(enableLowerClazyLevelsKey(), enableLowerClazyLevels());
     s->setValue(pchUsageKey(), pchUsage());
 
@@ -218,53 +127,9 @@ void CppCodeModelSettings::toSettings(QSettings *s)
 
     s->endGroup();
 
-    QVector<Id> invalidated
-        = ClangDiagnosticConfigsModel::changedOrRemovedConfigs(previousConfigs,
-                                                               m_clangCustomDiagnosticConfigs);
-
-    if (previousConfigId != clangDiagnosticConfigId() && !invalidated.contains(previousConfigId))
-        invalidated.append(previousConfigId);
-
-    if (!invalidated.isEmpty())
-        emit clangDiagnosticConfigsInvalidated(invalidated);
     emit changed();
 }
 
-Id CppCodeModelSettings::clangDiagnosticConfigId() const
-{
-    if (!diagnosticConfigsModel().hasConfigWithId(m_clangDiagnosticConfigId))
-        return defaultClangDiagnosticConfigId();
-    return m_clangDiagnosticConfigId;
-}
-
-void CppCodeModelSettings::setClangDiagnosticConfigId(const Id &configId)
-{
-    m_clangDiagnosticConfigId = configId;
-}
-
-Id CppCodeModelSettings::defaultClangDiagnosticConfigId()
-{
-    return initialClangDiagnosticConfigId();
-}
-
-const ClangDiagnosticConfig CppCodeModelSettings::clangDiagnosticConfig() const
-{
-    const ClangDiagnosticConfigsModel configsModel = diagnosticConfigsModel(
-        m_clangCustomDiagnosticConfigs);
-
-    return configsModel.configWithId(clangDiagnosticConfigId());
-}
-
-ClangDiagnosticConfigs CppCodeModelSettings::clangCustomDiagnosticConfigs() const
-{
-    return m_clangCustomDiagnosticConfigs;
-}
-
-void CppCodeModelSettings::setClangCustomDiagnosticConfigs(const ClangDiagnosticConfigs &configs)
-{
-    m_clangCustomDiagnosticConfigs = configs;
-}
-
 CppCodeModelSettings::PCHUsage CppCodeModelSettings::pchUsage() const
 {
     return m_pchUsage;
@@ -346,6 +211,14 @@ void ClangdSettings::setDefaultClangdPath(const FilePath &filePath)
     g_defaultClangdFilePath = filePath;
 }
 
+void ClangdSettings::setCustomDiagnosticConfigs(const ClangDiagnosticConfigs &configs)
+{
+    if (instance().customDiagnosticConfigs() == configs)
+        return;
+    instance().m_data.customDiagnosticConfigs = configs;
+    instance().saveSettings();
+}
+
 FilePath ClangdSettings::clangdFilePath() const
 {
     if (!m_data.executableFilePath.isEmpty())
@@ -358,6 +231,23 @@ bool ClangdSettings::sizeIsOkay(const Utils::FilePath &fp) const
     return !sizeThresholdEnabled() || sizeThresholdInKb() * 1024 >= fp.fileSize();
 }
 
+ClangDiagnosticConfigs ClangdSettings::customDiagnosticConfigs() const
+{
+    return m_data.customDiagnosticConfigs;
+}
+
+Id ClangdSettings::diagnosticConfigId() const
+{
+    if (!diagnosticConfigsModel().hasConfigWithId(m_data.diagnosticConfigId))
+        return initialClangDiagnosticConfigId();
+    return m_data.diagnosticConfigId;
+}
+
+ClangDiagnosticConfig ClangdSettings::diagnosticConfig() const
+{
+    return diagnosticConfigsModel(customDiagnosticConfigs()).configWithId(diagnosticConfigId());
+}
+
 ClangdSettings::Granularity ClangdSettings::granularity() const
 {
     if (m_data.sessionsWithOneClangd.contains(ProjectExplorer::SessionManager::activeSession()))
@@ -428,12 +318,30 @@ FilePath ClangdSettings::clangdUserConfigFilePath()
 
 void ClangdSettings::loadSettings()
 {
-    Utils::fromSettings(clangdSettingsKey(), {}, Core::ICore::settings(), &m_data);
+    const auto settings = Core::ICore::settings();
+    Utils::fromSettings(clangdSettingsKey(), {}, settings, &m_data);
+
+    settings->beginGroup(QLatin1String(Constants::CPPEDITOR_SETTINGSGROUP));
+    m_data.customDiagnosticConfigs = diagnosticConfigsFromSettings(settings);
+
+    // Pre-8.0 compat
+    static const QString oldKey("ClangDiagnosticConfig");
+    const QVariant configId = settings->value(oldKey);
+    if (configId.isValid()) {
+        m_data.diagnosticConfigId = Id::fromSetting(configId);
+        settings->setValue(oldKey, {});
+    }
+
+    settings->endGroup();
 }
 
 void ClangdSettings::saveSettings()
 {
-    Utils::toSettings(clangdSettingsKey(), {}, Core::ICore::settings(), &m_data);
+    const auto settings = Core::ICore::settings();
+    Utils::toSettings(clangdSettingsKey(), {}, settings, &m_data);
+    settings->beginGroup(QLatin1String(Constants::CPPEDITOR_SETTINGSGROUP));
+    diagnosticConfigsToSettings(settings, m_data.customDiagnosticConfigs);
+    settings->endGroup();
 }
 
 #ifdef WITH_TESTS
@@ -459,6 +367,9 @@ ClangdSettings::Data ClangdProjectSettings::settings() const
     // This property is global by definition.
     data.sessionsWithOneClangd = ClangdSettings::instance().data().sessionsWithOneClangd;
 
+    // This list exists only once.
+    data.customDiagnosticConfigs = ClangdSettings::instance().data().customDiagnosticConfigs;
+
     return data;
 }
 
@@ -466,6 +377,7 @@ void ClangdProjectSettings::setSettings(const ClangdSettings::Data &data)
 {
     m_customSettings = data;
     saveSettings();
+    ClangdSettings::setCustomDiagnosticConfigs(data.customDiagnosticConfigs);
     emit ClangdSettings::instance().changed();
 }
 
@@ -476,6 +388,12 @@ void ClangdProjectSettings::setUseGlobalSettings(bool useGlobal)
     emit ClangdSettings::instance().changed();
 }
 
+void ClangdProjectSettings::setDiagnosticConfigId(Utils::Id configId)
+{
+    m_customSettings.diagnosticConfigId = configId;
+    saveSettings();
+}
+
 void ClangdProjectSettings::loadSettings()
 {
     if (!m_project)
@@ -511,6 +429,7 @@ QVariantMap ClangdSettings::Data::toMap() const
     map.insert(clangdSizeThresholdEnabledKey(), sizeThresholdEnabled);
     map.insert(clangdSizeThresholdKey(), sizeThresholdInKb);
     map.insert(sessionsWithOneClangdKey(), sessionsWithOneClangd);
+    map.insert(diagnosticConfigIdKey(), diagnosticConfigId.toSetting());
     return map;
 }
 
@@ -525,6 +444,8 @@ void ClangdSettings::Data::fromMap(const QVariantMap &map)
     sizeThresholdEnabled = map.value(clangdSizeThresholdEnabledKey(), false).toBool();
     sizeThresholdInKb = map.value(clangdSizeThresholdKey(), 1024).toLongLong();
     sessionsWithOneClangd = map.value(sessionsWithOneClangdKey()).toStringList();
+    diagnosticConfigId = Id::fromSetting(map.value(diagnosticConfigIdKey(),
+                                                   initialClangDiagnosticConfigId().toSetting()));
 }
 
 } // namespace CppEditor
diff --git a/src/plugins/cppeditor/cppcodemodelsettings.h b/src/plugins/cppeditor/cppcodemodelsettings.h
index 1e0750d861..1bf5b46616 100644
--- a/src/plugins/cppeditor/cppcodemodelsettings.h
+++ b/src/plugins/cppeditor/cppcodemodelsettings.h
@@ -25,9 +25,11 @@
 
 #pragma once
 
-#include "clangdiagnosticconfigsmodel.h"
+#include "clangdiagnosticconfig.h"
+#include "cppeditor_global.h"
 
 #include <utils/fileutils.h>
+#include <utils/id.h>
 
 #include <QObject>
 #include <QStringList>
@@ -56,14 +58,6 @@ public:
     void toSettings(QSettings *s);
 
 public:
-    Utils::Id clangDiagnosticConfigId() const;
-    void setClangDiagnosticConfigId(const Utils::Id &configId);
-    static Utils::Id defaultClangDiagnosticConfigId() ;
-    const ClangDiagnosticConfig clangDiagnosticConfig() const;
-
-    ClangDiagnosticConfigs clangCustomDiagnosticConfigs() const;
-    void setClangCustomDiagnosticConfigs(const ClangDiagnosticConfigs &configs);
-
     bool enableLowerClazyLevels() const;
     void setEnableLowerClazyLevels(bool yesno);
 
@@ -91,8 +85,6 @@ private:
     bool m_interpretAmbigiousHeadersAsCHeaders = false;
     bool m_skipIndexingBigFiles = true;
     int m_indexerFileSizeLimitInMB = 5;
-    ClangDiagnosticConfigs m_clangCustomDiagnosticConfigs;
-    Utils::Id m_clangDiagnosticConfigId;
     bool m_enableLowerClazyLevels = true; // For UI behavior only
     bool m_categorizeFindReferences = false; // Ephemeral!
 };
@@ -112,6 +104,8 @@ public:
             return s1.useClangd == s2.useClangd
                     && s1.executableFilePath == s2.executableFilePath
                     && s1.sessionsWithOneClangd == s2.sessionsWithOneClangd
+                    && s1.customDiagnosticConfigs == s2.customDiagnosticConfigs
+                    && s1.diagnosticConfigId == s2.diagnosticConfigId
                     && s1.workerThreadLimit == s2.workerThreadLimit
                     && s1.enableIndexing == s2.enableIndexing
                     && s1.autoIncludeHeaders == s2.autoIncludeHeaders
@@ -123,6 +117,8 @@ public:
 
         Utils::FilePath executableFilePath;
         QStringList sessionsWithOneClangd;
+        ClangDiagnosticConfigs customDiagnosticConfigs;
+        Utils::Id diagnosticConfigId;
         int workerThreadLimit = 0;
         int documentUpdateThreshold = 500;
         qint64 sizeThresholdInKb = 1024;
@@ -138,6 +134,7 @@ public:
     bool useClangd() const;
 
     static void setDefaultClangdPath(const Utils::FilePath &filePath);
+    static void setCustomDiagnosticConfigs(const ClangDiagnosticConfigs &configs);
     Utils::FilePath clangdFilePath() const;
     bool indexingEnabled() const { return m_data.enableIndexing; }
     bool autoIncludeHeaders() const { return m_data.autoIncludeHeaders; }
@@ -146,6 +143,9 @@ public:
     qint64 sizeThresholdInKb() const { return m_data.sizeThresholdInKb; }
     bool sizeThresholdEnabled() const { return m_data.sizeThresholdEnabled; }
     bool sizeIsOkay(const Utils::FilePath &fp) const;
+    ClangDiagnosticConfigs customDiagnosticConfigs() const;
+    Utils::Id diagnosticConfigId() const;
+    ClangDiagnosticConfig diagnosticConfig() const;
 
     enum class Granularity { Project, Session };
     Granularity granularity() const;
@@ -184,6 +184,7 @@ public:
     void setSettings(const ClangdSettings::Data &data);
     bool useGlobalSettings() const { return m_useGlobalSettings; }
     void setUseGlobalSettings(bool useGlobal);
+    void setDiagnosticConfigId(Utils::Id configId);
 
 private:
     void loadSettings();
diff --git a/src/plugins/cppeditor/cppcodemodelsettingspage.cpp b/src/plugins/cppeditor/cppcodemodelsettingspage.cpp
index 390c50a367..bbfbf8bdd4 100644
--- a/src/plugins/cppeditor/cppcodemodelsettingspage.cpp
+++ b/src/plugins/cppeditor/cppcodemodelsettingspage.cpp
@@ -26,9 +26,9 @@
 #include "cppcodemodelsettingspage.h"
 #include "ui_cppcodemodelsettingspage.h"
 
+#include "clangdiagnosticconfigsselectionwidget.h"
 #include "clangdiagnosticconfigswidget.h"
 #include "cppeditorconstants.h"
-#include "cppmodelmanager.h"
 #include "cpptoolsreuse.h"
 
 #include <coreplugin/icore.h>
@@ -67,10 +67,8 @@ private:
     void apply() final;
 
     void setupGeneralWidgets();
-    void setupClangCodeModelWidgets();
 
     bool applyGeneralWidgetsToSettings() const;
-    bool applyClangCodeModelWidgetsToSettings() const;
 
     Ui::CppCodeModelSettingsPage *m_ui = nullptr;
     CppCodeModelSettings *m_settings = nullptr;
@@ -84,7 +82,6 @@ CppCodeModelSettingsWidget::CppCodeModelSettingsWidget(CppCodeModelSettings *s)
     m_settings = s;
 
     setupGeneralWidgets();
-    setupClangCodeModelWidgets();
 }
 
 CppCodeModelSettingsWidget::~CppCodeModelSettingsWidget()
@@ -94,35 +91,10 @@ CppCodeModelSettingsWidget::~CppCodeModelSettingsWidget()
 
 void CppCodeModelSettingsWidget::apply()
 {
-    bool changed = false;
-
-    changed |= applyGeneralWidgetsToSettings();
-    changed |= applyClangCodeModelWidgetsToSettings();
-
-    if (changed)
+    if (applyGeneralWidgetsToSettings())
         m_settings->toSettings(Core::ICore::settings());
 }
 
-void CppCodeModelSettingsWidget::setupClangCodeModelWidgets()
-{
-    m_ui->clangDiagnosticConfigsSelectionWidget
-        ->refresh(diagnosticConfigsModel(),
-                  m_settings->clangDiagnosticConfigId(),
-                  [](const ClangDiagnosticConfigs &configs, const Utils::Id &configToSelect) {
-                      return new ClangDiagnosticConfigsWidget(configs, configToSelect);
-                  });
-
-    const bool isClangActive = CppModelManager::instance()->isClangCodeModelActive();
-    m_ui->clangCodeModelIsDisabledHint->setVisible(!isClangActive);
-    m_ui->clangCodeModelIsEnabledHint->setVisible(isClangActive);
-
-    for (int i = 0; i < m_ui->clangDiagnosticConfigsSelectionWidget->layout()->count(); ++i) {
-        QWidget *widget = m_ui->clangDiagnosticConfigsSelectionWidget->layout()->itemAt(i)->widget();
-        if (widget)
-            widget->setEnabled(isClangActive);
-    }
-}
-
 void CppCodeModelSettingsWidget::setupGeneralWidgets()
 {
     m_ui->interpretAmbiguousHeadersAsCHeaders->setChecked(
@@ -135,28 +107,6 @@ void CppCodeModelSettingsWidget::setupGeneralWidgets()
     m_ui->ignorePCHCheckBox->setChecked(ignorePch);
 }
 
-bool CppCodeModelSettingsWidget::applyClangCodeModelWidgetsToSettings() const
-{
-    bool changed = false;
-
-    const Utils::Id oldConfigId = m_settings->clangDiagnosticConfigId();
-    const Utils::Id currentConfigId = m_ui->clangDiagnosticConfigsSelectionWidget->currentConfigId();
-    if (oldConfigId != currentConfigId) {
-        m_settings->setClangDiagnosticConfigId(currentConfigId);
-        changed = true;
-    }
-
-    const ClangDiagnosticConfigs oldConfigs = m_settings->clangCustomDiagnosticConfigs();
-    const ClangDiagnosticConfigs currentConfigs = m_ui->clangDiagnosticConfigsSelectionWidget
-                                                      ->customConfigs();
-    if (oldConfigs != currentConfigs) {
-        m_settings->setClangCustomDiagnosticConfigs(currentConfigs);
-        changed = true;
-    }
-
-    return changed;
-}
-
 bool CppCodeModelSettingsWidget::applyGeneralWidgetsToSettings() const
 {
     bool settingsChanged = false;
@@ -215,6 +165,7 @@ public:
     QSpinBox sizeThresholdSpinBox;
     Utils::PathChooser clangdChooser;
     Utils::InfoLabel versionWarningLabel;
+    ClangDiagnosticConfigsSelectionWidget *configSelectionWidget = nullptr;
     QGroupBox *sessionsGroupBox = nullptr;
     QStringListModel sessionsModel;
 };
@@ -283,8 +234,15 @@ ClangdSettingsWidget::ClangdSettingsWidget(const ClangdSettings::Data &settingsD
     sizeThresholdLayout->addWidget(&d->sizeThresholdSpinBox);
     sizeThresholdLayout->addStretch(1);
     formLayout->addRow(&d->sizeThresholdCheckBox, sizeThresholdLayout);
-    layout->addLayout(formLayout);
+    d->configSelectionWidget = new ClangDiagnosticConfigsSelectionWidget(formLayout);
+    d->configSelectionWidget->refresh(
+                diagnosticConfigsModel(settings.customDiagnosticConfigs()),
+                settings.diagnosticConfigId(),
+                [](const ClangDiagnosticConfigs &configs, const Utils::Id &configToSelect) {
+                    return new CppEditor::ClangDiagnosticConfigsWidget(configs, configToSelect);
+                });
 
+    layout->addLayout(formLayout);
     if (!isForProject) {
         d->sessionsModel.setStringList(settingsData.sessionsWithOneClangd);
         d->sessionsModel.sort(0);
@@ -427,6 +385,8 @@ ClangdSettingsWidget::ClangdSettingsWidget(const ClangdSettings::Data &settingsD
             this, &ClangdSettingsWidget::settingsDataChanged);
     connect(&d->clangdChooser, &Utils::PathChooser::pathChanged,
             this, &ClangdSettingsWidget::settingsDataChanged);
+    connect(d->configSelectionWidget, &ClangDiagnosticConfigsSelectionWidget::changed,
+            this, &ClangdSettingsWidget::settingsDataChanged);
 }
 
 ClangdSettingsWidget::~ClangdSettingsWidget()
@@ -446,6 +406,8 @@ ClangdSettings::Data ClangdSettingsWidget::settingsData() const
     data.sizeThresholdEnabled = d->sizeThresholdCheckBox.isChecked();
     data.sizeThresholdInKb = d->sizeThresholdSpinBox.value();
     data.sessionsWithOneClangd = d->sessionsModel.stringList();
+    data.customDiagnosticConfigs = d->configSelectionWidget->customConfigs();
+    data.diagnosticConfigId = d->configSelectionWidget->currentConfigId();
     return data;
 }
 
diff --git a/src/plugins/cppeditor/cppcodemodelsettingspage.ui b/src/plugins/cppeditor/cppcodemodelsettingspage.ui
index e4cf04fcd2..43b9e70352 100644
--- a/src/plugins/cppeditor/cppcodemodelsettingspage.ui
+++ b/src/plugins/cppeditor/cppcodemodelsettingspage.ui
@@ -87,49 +87,6 @@
     </widget>
    </item>
    <item>
-    <widget class="QGroupBox" name="groupBox">
-     <property name="title">
-      <string>Clang Code Model</string>
-     </property>
-     <layout class="QVBoxLayout" name="verticalLayout_3">
-      <item>
-       <widget class="QLabel" name="clangCodeModelIsEnabledHint">
-        <property name="text">
-         <string>&lt;i&gt;The Clang Code Model is enabled because the corresponding plugin is loaded.&lt;/i&gt;</string>
-        </property>
-       </widget>
-      </item>
-      <item>
-       <widget class="QLabel" name="clangCodeModelIsDisabledHint">
-        <property name="text">
-         <string>&lt;i&gt;The Clang Code Model is disabled because the corresponding plugin is not loaded.&lt;/i&gt;</string>
-        </property>
-       </widget>
-      </item>
-      <item>
-       <widget class="CppEditor::ClangDiagnosticConfigsSelectionWidget" name="clangDiagnosticConfigsSelectionWidget" native="true"/>
-      </item>
-      <item>
-       <layout class="QHBoxLayout" name="horizontalLayout_2">
-        <item>
-         <spacer name="horizontalSpacer_2">
-          <property name="orientation">
-           <enum>Qt::Horizontal</enum>
-          </property>
-          <property name="sizeHint" stdset="0">
-           <size>
-            <width>40</width>
-            <height>20</height>
-           </size>
-          </property>
-         </spacer>
-        </item>
-       </layout>
-      </item>
-     </layout>
-    </widget>
-   </item>
-   <item>
     <spacer name="verticalSpacer">
      <property name="orientation">
       <enum>Qt::Vertical</enum>
@@ -144,13 +101,6 @@
    </item>
   </layout>
  </widget>
- <customwidgets>
-  <customwidget>
-   <class>CppEditor::ClangDiagnosticConfigsSelectionWidget</class>
-   <extends>QWidget</extends>
-   <header>cppeditor/clangdiagnosticconfigsselectionwidget.h</header>
-  </customwidget>
- </customwidgets>
  <resources/>
  <connections/>
 </ui>
diff --git a/src/plugins/cppeditor/cpptoolsreuse.cpp b/src/plugins/cppeditor/cpptoolsreuse.cpp
index e2362efa58..34d4aac046 100644
--- a/src/plugins/cppeditor/cpptoolsreuse.cpp
+++ b/src/plugins/cppeditor/cpptoolsreuse.cpp
@@ -25,6 +25,7 @@
 
 #include "cpptoolsreuse.h"
 
+#include "clangdiagnosticconfigsmodel.h"
 #include "cppautocompleter.h"
 #include "cppcodemodelsettings.h"
 #include "cppeditorconstants.h"
@@ -423,7 +424,7 @@ ClangDiagnosticConfigsModel diagnosticConfigsModel(const ClangDiagnosticConfigs
 
 ClangDiagnosticConfigsModel diagnosticConfigsModel()
 {
-    return diagnosticConfigsModel(codeModelSettings()->clangCustomDiagnosticConfigs());
+    return diagnosticConfigsModel(ClangdSettings::instance().customDiagnosticConfigs());
 }
 
 NSVisitor::NSVisitor(const CppRefactoringFile *file, const QStringList &namespaces, int symbolPos)