CppEditor: Move ClangdSettings into a dedicated set of files

They were originally put alongside the CppCodeModelSettings for
simplicity, but there is no coupling (anymore?) between these two
classes.

Change-Id: Ic24df109b74a5b5c39de073c938c6de12f4aa319
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: David Schulz <david.schulz@qt.io>

9 files changed, 660 insertions, 620 deletions

diff --git a/src/plugins/cppeditor/CMakeLists.txt b/src/plugins/cppeditor/CMakeLists.txt
index ec5ad89cea..93c37beaca 100644
--- a/src/plugins/cppeditor/CMakeLists.txt
+++ b/src/plugins/cppeditor/CMakeLists.txt
@@ -93,6 +93,7 @@ add_qtc_plugin(CppEditor
     cppvirtualfunctionassistprovider.cpp cppvirtualfunctionassistprovider.h
     cppvirtualfunctionproposalitem.cpp cppvirtualfunctionproposalitem.h
     cppworkingcopy.cpp cppworkingcopy.h
+    clangdsettings.cpp clangdsettings.h
     cursorineditor.h
     doxygengenerator.cpp doxygengenerator.h
     editordocumenthandle.cpp editordocumenthandle.h
diff --git a/src/plugins/cppeditor/clangdsettings.cpp b/src/plugins/cppeditor/clangdsettings.cpp
new file mode 100644
index 0000000000..b5352af6d8
--- /dev/null
+++ b/src/plugins/cppeditor/clangdsettings.cpp
@@ -0,0 +1,491 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#include "clangdsettings.h"
+
+#include "clangdiagnosticconfigsmodel.h"
+#include "cppeditorconstants.h"
+#include "cppeditortr.h"
+#include "cpptoolsreuse.h"
+
+#include <coreplugin/icore.h>
+#include <coreplugin/session.h>
+#include <projectexplorer/project.h>
+#include <utils/clangutils.h>
+#include <utils/qtcprocess.h>
+
+#include <QStandardPaths>
+#include <QVersionNumber>
+
+using namespace Utils;
+
+namespace CppEditor {
+
+static FilePath g_defaultClangdFilePath;
+static FilePath fallbackClangdFilePath()
+{
+    if (g_defaultClangdFilePath.exists())
+        return g_defaultClangdFilePath;
+    return Environment::systemEnvironment().searchInPath("clangd");
+}
+
+static Id initialClangDiagnosticConfigId() { return Constants::CPP_CLANG_DIAG_CONFIG_BUILDSYSTEM; }
+
+static Key clangdSettingsKey() { return "ClangdSettings"; }
+static Key useClangdKey() { return "UseClangdV7"; }
+static Key clangdPathKey() { return "ClangdPath"; }
+static Key clangdIndexingKey() { return "ClangdIndexing"; }
+static Key clangdProjectIndexPathKey() { return "ClangdProjectIndexPath"; }
+static Key clangdSessionIndexPathKey() { return "ClangdSessionIndexPath"; }
+static Key clangdIndexingPriorityKey() { return "ClangdIndexingPriority"; }
+static Key clangdHeaderSourceSwitchModeKey() { return "ClangdHeaderSourceSwitchMode"; }
+static Key clangdCompletionRankingModelKey() { return "ClangdCompletionRankingModel"; }
+static Key clangdHeaderInsertionKey() { return "ClangdHeaderInsertion"; }
+static Key clangdThreadLimitKey() { return "ClangdThreadLimit"; }
+static Key clangdDocumentThresholdKey() { return "ClangdDocumentThreshold"; }
+static Key clangdSizeThresholdEnabledKey() { return "ClangdSizeThresholdEnabled"; }
+static Key clangdSizeThresholdKey() { return "ClangdSizeThreshold"; }
+static Key useGlobalSettingsKey() { return "useGlobalSettings"; }
+static Key clangdblockIndexingSettingsKey() { return "blockIndexing"; }
+static Key sessionsWithOneClangdKey() { return "SessionsWithOneClangd"; }
+static Key diagnosticConfigIdKey() { return "diagnosticConfigId"; }
+static Key checkedHardwareKey() { return "checkedHardware"; }
+static Key completionResultsKey() { return "completionResults"; }
+
+QString ClangdSettings::priorityToString(const IndexingPriority &priority)
+{
+    switch (priority) {
+    case IndexingPriority::Background: return "background";
+    case IndexingPriority::Normal: return "normal";
+    case IndexingPriority::Low: return "low";
+    case IndexingPriority::Off: return {};
+    }
+    return {};
+}
+
+QString ClangdSettings::priorityToDisplayString(const IndexingPriority &priority)
+{
+    switch (priority) {
+    case IndexingPriority::Background: return Tr::tr("Background Priority");
+    case IndexingPriority::Normal: return Tr::tr("Normal Priority");
+    case IndexingPriority::Low: return Tr::tr("Low Priority");
+    case IndexingPriority::Off: return Tr::tr("Off");
+    }
+    return {};
+}
+
+QString ClangdSettings::headerSourceSwitchModeToDisplayString(HeaderSourceSwitchMode mode)
+{
+    switch (mode) {
+    case HeaderSourceSwitchMode::BuiltinOnly: return Tr::tr("Use Built-in Only");
+    case HeaderSourceSwitchMode::ClangdOnly: return Tr::tr("Use Clangd Only");
+    case HeaderSourceSwitchMode::Both: return Tr::tr("Try Both");
+    }
+    return {};
+}
+
+QString ClangdSettings::rankingModelToCmdLineString(CompletionRankingModel model)
+{
+    switch (model) {
+    case CompletionRankingModel::Default: break;
+    case CompletionRankingModel::DecisionForest: return "decision_forest";
+    case CompletionRankingModel::Heuristics: return "heuristics";
+    }
+    QTC_ASSERT(false, return {});
+}
+
+QString ClangdSettings::rankingModelToDisplayString(CompletionRankingModel model)
+{
+    switch (model) {
+    case CompletionRankingModel::Default: return Tr::tr("Default");
+    case CompletionRankingModel::DecisionForest: return Tr::tr("Decision Forest");
+    case CompletionRankingModel::Heuristics: return Tr::tr("Heuristics");
+    }
+    QTC_ASSERT(false, return {});
+}
+
+QString ClangdSettings::defaultProjectIndexPathTemplate()
+{
+    return QDir::toNativeSeparators("%{BuildConfig:BuildDirectory:FilePath}/.qtc_clangd");
+}
+
+QString ClangdSettings::defaultSessionIndexPathTemplate()
+{
+    return QDir::toNativeSeparators("%{IDE:UserResourcePath}/.qtc_clangd/%{Session:FileBaseName}");
+}
+
+ClangdSettings &ClangdSettings::instance()
+{
+    static ClangdSettings settings;
+    return settings;
+}
+
+ClangdSettings::ClangdSettings()
+{
+    loadSettings();
+    const auto sessionMgr = Core::SessionManager::instance();
+    connect(sessionMgr, &Core::SessionManager::sessionRemoved, this, [this](const QString &name) {
+        m_data.sessionsWithOneClangd.removeOne(name);
+    });
+    connect(sessionMgr,
+            &Core::SessionManager::sessionRenamed,
+            this,
+            [this](const QString &oldName, const QString &newName) {
+                const auto index = m_data.sessionsWithOneClangd.indexOf(oldName);
+                if (index != -1)
+                    m_data.sessionsWithOneClangd[index] = newName;
+            });
+}
+
+bool ClangdSettings::useClangd() const
+{
+    return m_data.useClangd && clangdVersion(clangdFilePath()) >= minimumClangdVersion();
+}
+
+void ClangdSettings::setUseClangd(bool use) { instance().m_data.useClangd = use; }
+
+void ClangdSettings::setUseClangdAndSave(bool use)
+{
+    setUseClangd(use);
+    instance().saveSettings();
+}
+
+bool ClangdSettings::hardwareFulfillsRequirements()
+{
+    instance().m_data.haveCheckedHardwareReqirements = true;
+    instance().saveSettings();
+    const quint64 minRam = quint64(12) * 1024 * 1024 * 1024;
+    const std::optional<quint64> totalRam = Utils::HostOsInfo::totalMemoryInstalledInBytes();
+    return !totalRam || *totalRam >= minRam;
+}
+
+bool ClangdSettings::haveCheckedHardwareRequirements()
+{
+    return instance().data().haveCheckedHardwareReqirements;
+}
+
+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())
+        return m_data.executableFilePath;
+    return fallbackClangdFilePath();
+}
+
+FilePath ClangdSettings::projectIndexPath(const Utils::MacroExpander &expander) const
+{
+    return FilePath::fromUserInput(expander.expand(m_data.projectIndexPathTemplate));
+}
+
+FilePath ClangdSettings::sessionIndexPath(const Utils::MacroExpander &expander) const
+{
+    return FilePath::fromUserInput(expander.expand(m_data.sessionIndexPathTemplate));
+}
+
+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(Core::SessionManager::activeSession()))
+        return Granularity::Session;
+    return Granularity::Project;
+}
+
+void ClangdSettings::setData(const Data &data)
+{
+    if (this == &instance() && data != m_data) {
+        m_data = data;
+        saveSettings();
+        emit changed();
+    }
+}
+
+static FilePath getClangHeadersPathFromClang(const FilePath &clangdFilePath)
+{
+    const FilePath clangFilePath = clangdFilePath.absolutePath().pathAppended("clang")
+                                       .withExecutableSuffix();
+    if (!clangFilePath.exists())
+        return {};
+    Process clang;
+    clang.setCommand({clangFilePath, {"-print-resource-dir"}});
+    clang.start();
+    if (!clang.waitForFinished())
+        return {};
+    const FilePath resourceDir = FilePath::fromUserInput(QString::fromLocal8Bit(
+        clang.rawStdOut().trimmed()));
+    if (resourceDir.isEmpty() || !resourceDir.exists())
+        return {};
+    const FilePath includeDir = resourceDir.pathAppended("include");
+    if (!includeDir.exists())
+        return {};
+    return includeDir;
+}
+
+static FilePath getClangHeadersPath(const FilePath &clangdFilePath)
+{
+    const FilePath headersPath = getClangHeadersPathFromClang(clangdFilePath);
+    if (!headersPath.isEmpty())
+        return headersPath;
+
+    const QVersionNumber version = Utils::clangdVersion(clangdFilePath);
+    QTC_ASSERT(!version.isNull(), return {});
+    static const QStringList libDirs{"lib", "lib64"};
+    const QStringList versionStrings{QString::number(version.majorVersion()), version.toString()};
+    for (const QString &libDir : libDirs) {
+        for (const QString &versionString : versionStrings) {
+            const FilePath includePath = clangdFilePath.absolutePath().parentDir()
+                                             .pathAppended(libDir).pathAppended("clang")
+                                             .pathAppended(versionString).pathAppended("include");
+            if (includePath.exists())
+                return includePath;
+        }
+    }
+    QTC_CHECK(false);
+    return {};
+}
+
+FilePath ClangdSettings::clangdIncludePath() const
+{
+    QTC_ASSERT(useClangd(), return {});
+    FilePath clangdPath = clangdFilePath();
+    QTC_ASSERT(!clangdPath.isEmpty() && clangdPath.exists(), return {});
+    static QHash<FilePath, FilePath> headersPathCache;
+    const auto it = headersPathCache.constFind(clangdPath);
+    if (it != headersPathCache.constEnd())
+        return *it;
+    const FilePath headersPath = getClangHeadersPath(clangdPath);
+    if (!headersPath.isEmpty())
+        headersPathCache.insert(clangdPath, headersPath);
+    return headersPath;
+}
+
+FilePath ClangdSettings::clangdUserConfigFilePath()
+{
+    return FilePath::fromString(
+               QStandardPaths::writableLocation(QStandardPaths::GenericConfigLocation))
+           / "clangd/config.yaml";
+}
+
+void ClangdSettings::loadSettings()
+{
+    const auto settings = Core::ICore::settings();
+
+    m_data.fromMap(Utils::storeFromSettings(clangdSettingsKey(), settings));
+
+    settings->beginGroup(Constants::CPPEDITOR_SETTINGSGROUP);
+    m_data.customDiagnosticConfigs = diagnosticConfigsFromSettings(settings);
+
+    // Pre-8.0 compat
+    static const Key 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()
+{
+    const auto settings = Core::ICore::settings();
+    const ClangdSettings::Data defaultData;
+    Utils::storeToSettingsWithDefault(clangdSettingsKey(),
+                                      settings,
+                                      m_data.toMap(),
+                                      defaultData.toMap());
+    settings->beginGroup(Constants::CPPEDITOR_SETTINGSGROUP);
+    diagnosticConfigsToSettings(settings, m_data.customDiagnosticConfigs);
+    settings->endGroup();
+}
+
+#ifdef WITH_TESTS
+void ClangdSettings::setClangdFilePath(const FilePath &filePath)
+{
+    instance().m_data.executableFilePath = filePath;
+}
+#endif
+
+ClangdProjectSettings::ClangdProjectSettings(ProjectExplorer::Project *project) : m_project(project)
+{
+    loadSettings();
+}
+
+ClangdSettings::Data ClangdProjectSettings::settings() const
+{
+    const ClangdSettings::Data globalData = ClangdSettings::instance().data();
+    ClangdSettings::Data data = globalData;
+    if (!m_useGlobalSettings) {
+        data = m_customSettings;
+        // This property is global by definition.
+        data.sessionsWithOneClangd = ClangdSettings::instance().data().sessionsWithOneClangd;
+
+        // This list exists only once.
+        data.customDiagnosticConfigs = ClangdSettings::instance().data().customDiagnosticConfigs;
+    }
+    if (m_blockIndexing)
+        data.indexingPriority = ClangdSettings::IndexingPriority::Off;
+    return data;
+}
+
+void ClangdProjectSettings::setSettings(const ClangdSettings::Data &data)
+{
+    m_customSettings = data;
+    saveSettings();
+    ClangdSettings::setCustomDiagnosticConfigs(data.customDiagnosticConfigs);
+    emit ClangdSettings::instance().changed();
+}
+
+void ClangdProjectSettings::setUseGlobalSettings(bool useGlobal)
+{
+    m_useGlobalSettings = useGlobal;
+    saveSettings();
+    emit ClangdSettings::instance().changed();
+}
+
+void ClangdProjectSettings::setDiagnosticConfigId(Utils::Id configId)
+{
+    m_customSettings.diagnosticConfigId = configId;
+    saveSettings();
+    emit ClangdSettings::instance().changed();
+}
+
+void ClangdProjectSettings::blockIndexing()
+{
+    if (m_blockIndexing)
+        return;
+    m_blockIndexing = true;
+    saveSettings();
+    emit ClangdSettings::instance().changed();
+}
+
+void ClangdProjectSettings::unblockIndexing()
+{
+    if (!m_blockIndexing)
+        return;
+    m_blockIndexing = false;
+    saveSettings();
+    // Do not emit changed here since that would restart clients with blocked indexing
+}
+
+void ClangdProjectSettings::loadSettings()
+{
+    if (!m_project)
+        return;
+    const Store data = storeFromVariant(m_project->namedSettings(clangdSettingsKey()));
+    m_useGlobalSettings = data.value(useGlobalSettingsKey(), true).toBool();
+    m_blockIndexing = data.value(clangdblockIndexingSettingsKey(), false).toBool();
+    if (!m_useGlobalSettings)
+        m_customSettings.fromMap(data);
+}
+
+void ClangdProjectSettings::saveSettings()
+{
+    if (!m_project)
+        return;
+    Store data;
+    if (!m_useGlobalSettings)
+        data = m_customSettings.toMap();
+    data.insert(useGlobalSettingsKey(), m_useGlobalSettings);
+    data.insert(clangdblockIndexingSettingsKey(), m_blockIndexing);
+    m_project->setNamedSettings(clangdSettingsKey(), variantFromStore(data));
+}
+
+Store ClangdSettings::Data::toMap() const
+{
+    Store map;
+
+    map.insert(useClangdKey(), useClangd);
+
+    map.insert(clangdPathKey(),
+               executableFilePath != fallbackClangdFilePath() ? executableFilePath.toString()
+                                                              : QString());
+
+    map.insert(clangdIndexingKey(), indexingPriority != IndexingPriority::Off);
+    map.insert(clangdIndexingPriorityKey(), int(indexingPriority));
+    map.insert(clangdProjectIndexPathKey(), projectIndexPathTemplate);
+    map.insert(clangdSessionIndexPathKey(), sessionIndexPathTemplate);
+    map.insert(clangdHeaderSourceSwitchModeKey(), int(headerSourceSwitchMode));
+    map.insert(clangdCompletionRankingModelKey(), int(completionRankingModel));
+    map.insert(clangdHeaderInsertionKey(), autoIncludeHeaders);
+    map.insert(clangdThreadLimitKey(), workerThreadLimit);
+    map.insert(clangdDocumentThresholdKey(), documentUpdateThreshold);
+    map.insert(clangdSizeThresholdEnabledKey(), sizeThresholdEnabled);
+    map.insert(clangdSizeThresholdKey(), sizeThresholdInKb);
+    map.insert(sessionsWithOneClangdKey(), sessionsWithOneClangd);
+    map.insert(diagnosticConfigIdKey(), diagnosticConfigId.toSetting());
+    map.insert(checkedHardwareKey(), haveCheckedHardwareReqirements);
+    map.insert(completionResultsKey(), completionResults);
+    return map;
+}
+
+void ClangdSettings::Data::fromMap(const Store &map)
+{
+    useClangd = map.value(useClangdKey(), true).toBool();
+    executableFilePath = FilePath::fromString(map.value(clangdPathKey()).toString());
+    indexingPriority = IndexingPriority(
+        map.value(clangdIndexingPriorityKey(), int(this->indexingPriority)).toInt());
+    const auto it = map.find(clangdIndexingKey());
+    if (it != map.end() && !it->toBool())
+        indexingPriority = IndexingPriority::Off;
+    projectIndexPathTemplate
+        = map.value(clangdProjectIndexPathKey(), defaultProjectIndexPathTemplate()).toString();
+    sessionIndexPathTemplate
+        = map.value(clangdSessionIndexPathKey(), defaultSessionIndexPathTemplate()).toString();
+    headerSourceSwitchMode = HeaderSourceSwitchMode(map.value(clangdHeaderSourceSwitchModeKey(),
+                                                              int(headerSourceSwitchMode)).toInt());
+    completionRankingModel = CompletionRankingModel(map.value(clangdCompletionRankingModelKey(),
+                                                              int(completionRankingModel)).toInt());
+    autoIncludeHeaders = map.value(clangdHeaderInsertionKey(), false).toBool();
+    workerThreadLimit = map.value(clangdThreadLimitKey(), 0).toInt();
+    documentUpdateThreshold = map.value(clangdDocumentThresholdKey(), 500).toInt();
+    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()));
+    haveCheckedHardwareReqirements = map.value(checkedHardwareKey(), false).toBool();
+    completionResults = map.value(completionResultsKey(), defaultCompletionResults()).toInt();
+}
+
+int ClangdSettings::Data::defaultCompletionResults()
+{
+    // Default clangd --limit-results value is 100
+    bool ok = false;
+    const int userValue = qtcEnvironmentVariableIntValue("QTC_CLANGD_COMPLETION_RESULTS", &ok);
+    return ok ? userValue : 100;
+}
+
+} // namespace CppEditor
diff --git a/src/plugins/cppeditor/clangdsettings.h b/src/plugins/cppeditor/clangdsettings.h
new file mode 100644
index 0000000000..c1fb3b6ae8
--- /dev/null
+++ b/src/plugins/cppeditor/clangdsettings.h
@@ -0,0 +1,162 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+#pragma once
+
+#include "clangdiagnosticconfig.h"
+#include "cppeditor_global.h"
+
+#include <utils/filepath.h>
+#include <utils/store.h>
+
+namespace ProjectExplorer { class Project; }
+namespace Utils { class MacroExpander; }
+
+namespace CppEditor {
+
+// TODO: Can we move this to ClangCodeModel?
+class CPPEDITOR_EXPORT ClangdSettings : public QObject
+{
+    Q_OBJECT
+public:
+    enum class IndexingPriority { Off, Background, Normal, Low, };
+    enum class HeaderSourceSwitchMode { BuiltinOnly, ClangdOnly, Both };
+    enum class CompletionRankingModel { Default, DecisionForest, Heuristics };
+
+    static QString priorityToString(const IndexingPriority &priority);
+    static QString priorityToDisplayString(const IndexingPriority &priority);
+    static QString headerSourceSwitchModeToDisplayString(HeaderSourceSwitchMode mode);
+    static QString rankingModelToCmdLineString(CompletionRankingModel model);
+    static QString rankingModelToDisplayString(CompletionRankingModel model);
+    static QString defaultProjectIndexPathTemplate();
+    static QString defaultSessionIndexPathTemplate();
+
+    class CPPEDITOR_EXPORT Data
+    {
+    public:
+        Utils::Store toMap() const;
+        void fromMap(const Utils::Store &map);
+
+        friend bool operator==(const Data &s1, const Data &s2)
+        {
+            return s1.useClangd == s2.useClangd
+                   && s1.executableFilePath == s2.executableFilePath
+                   && s1.projectIndexPathTemplate == s2.projectIndexPathTemplate
+                   && s1.sessionIndexPathTemplate == s2.sessionIndexPathTemplate
+                   && s1.sessionsWithOneClangd == s2.sessionsWithOneClangd
+                   && s1.customDiagnosticConfigs == s2.customDiagnosticConfigs
+                   && s1.diagnosticConfigId == s2.diagnosticConfigId
+                   && s1.workerThreadLimit == s2.workerThreadLimit
+                   && s1.indexingPriority == s2.indexingPriority
+                   && s1.headerSourceSwitchMode == s2.headerSourceSwitchMode
+                   && s1.completionRankingModel == s2.completionRankingModel
+                   && s1.autoIncludeHeaders == s2.autoIncludeHeaders
+                   && s1.documentUpdateThreshold == s2.documentUpdateThreshold
+                   && s1.sizeThresholdEnabled == s2.sizeThresholdEnabled
+                   && s1.sizeThresholdInKb == s2.sizeThresholdInKb
+                   && s1.haveCheckedHardwareReqirements == s2.haveCheckedHardwareReqirements
+                   && s1.completionResults == s2.completionResults;
+        }
+        friend bool operator!=(const Data &s1, const Data &s2) { return !(s1 == s2); }
+
+        Utils::FilePath executableFilePath;
+        QStringList sessionsWithOneClangd;
+        ClangDiagnosticConfigs customDiagnosticConfigs;
+        Utils::Id diagnosticConfigId;
+
+        int workerThreadLimit = 0;
+        int documentUpdateThreshold = 500;
+        qint64 sizeThresholdInKb = 1024;
+        bool useClangd = true;
+        IndexingPriority indexingPriority = IndexingPriority::Low;
+        QString projectIndexPathTemplate = defaultProjectIndexPathTemplate();
+        QString sessionIndexPathTemplate = defaultSessionIndexPathTemplate();
+        HeaderSourceSwitchMode headerSourceSwitchMode = HeaderSourceSwitchMode::Both;
+        CompletionRankingModel completionRankingModel = CompletionRankingModel::Default;
+        bool autoIncludeHeaders = false;
+        bool sizeThresholdEnabled = false;
+        bool haveCheckedHardwareReqirements = false;
+        int completionResults = defaultCompletionResults();
+
+    private:
+        static int defaultCompletionResults();
+    };
+
+    ClangdSettings(const Data &data) : m_data(data) {}
+
+    static ClangdSettings &instance();
+    bool useClangd() const;
+    static void setUseClangd(bool use);
+    static void setUseClangdAndSave(bool use);
+
+    static bool hardwareFulfillsRequirements();
+    static bool haveCheckedHardwareRequirements();
+
+    static void setDefaultClangdPath(const Utils::FilePath &filePath);
+    static void setCustomDiagnosticConfigs(const ClangDiagnosticConfigs &configs);
+    Utils::FilePath clangdFilePath() const;
+    IndexingPriority indexingPriority() const { return m_data.indexingPriority; }
+    Utils::FilePath projectIndexPath(const Utils::MacroExpander &expander) const;
+    Utils::FilePath sessionIndexPath(const Utils::MacroExpander &expander) const;
+    HeaderSourceSwitchMode headerSourceSwitchMode() const { return m_data.headerSourceSwitchMode; }
+    CompletionRankingModel completionRankingModel() const { return m_data.completionRankingModel; }
+    bool autoIncludeHeaders() const { return m_data.autoIncludeHeaders; }
+    int workerThreadLimit() const { return m_data.workerThreadLimit; }
+    int documentUpdateThreshold() const { return m_data.documentUpdateThreshold; }
+    qint64 sizeThresholdInKb() const { return m_data.sizeThresholdInKb; }
+    bool sizeThresholdEnabled() const { return m_data.sizeThresholdEnabled; }
+    int completionResults() const { return m_data.completionResults; }
+    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;
+
+    void setData(const Data &data);
+    Data data() const { return m_data; }
+
+    Utils::FilePath clangdIncludePath() const;
+    static Utils::FilePath clangdUserConfigFilePath();
+
+#ifdef WITH_TESTS
+    static void setClangdFilePath(const Utils::FilePath &filePath);
+#endif
+
+signals:
+    void changed();
+
+private:
+    ClangdSettings();
+
+    void loadSettings();
+    void saveSettings();
+
+    Data m_data;
+};
+
+class CPPEDITOR_EXPORT ClangdProjectSettings
+{
+public:
+    ClangdProjectSettings(ProjectExplorer::Project *project);
+
+    ClangdSettings::Data settings() const;
+    void setSettings(const ClangdSettings::Data &data);
+    bool useGlobalSettings() const { return m_useGlobalSettings; }
+    void setUseGlobalSettings(bool useGlobal);
+    void setDiagnosticConfigId(Utils::Id configId);
+    void blockIndexing();
+    void unblockIndexing();
+
+private:
+    void loadSettings();
+    void saveSettings();
+
+    ProjectExplorer::Project * const m_project;
+    ClangdSettings::Data m_customSettings;
+    bool m_useGlobalSettings = true;
+    bool m_blockIndexing = false;
+};
+
+} // namespace CppEditor
diff --git a/src/plugins/cppeditor/cppcodemodelsettings.cpp b/src/plugins/cppeditor/cppcodemodelsettings.cpp
index d1b4c47098..d4a309363a 100644
--- a/src/plugins/cppeditor/cppcodemodelsettings.cpp
+++ b/src/plugins/cppeditor/cppcodemodelsettings.cpp
@@ -3,14 +3,10 @@
 
 #include "cppcodemodelsettings.h"
 
-#include "clangdiagnosticconfigsmodel.h"
 #include "compileroptionsbuilder.h"
 #include "cppeditorconstants.h"
-#include "cppeditortr.h"
-#include "cpptoolsreuse.h"
 
 #include <coreplugin/icore.h>
-#include <coreplugin/session.h>
 
 #include <projectexplorer/project.h>
 #include <projectexplorer/projectmanager.h>
@@ -27,14 +23,12 @@
 #include <QHash>
 #include <QPair>
 #include <QSettings>
-#include <QStandardPaths>
 
 using namespace ProjectExplorer;
 using namespace Utils;
 
 namespace CppEditor {
 
-static Id initialClangDiagnosticConfigId() { return Constants::CPP_CLANG_DIAG_CONFIG_BUILDSYSTEM; }
 static Key pchUsageKey() { return Constants::CPPEDITOR_MODEL_MANAGER_PCH_USAGE; }
 static Key interpretAmbiguousHeadersAsCHeadersKey()
     { return Constants::CPPEDITOR_INTERPRET_AMBIGIUOUS_HEADERS_AS_C_HEADERS; }
@@ -43,35 +37,7 @@ static Key ignoreFilesKey() { return Constants::CPPEDITOR_IGNORE_FILES; }
 static Key ignorePatternKey() { return Constants::CPPEDITOR_IGNORE_PATTERN; }
 static Key useBuiltinPreprocessorKey() { return Constants::CPPEDITOR_USE_BUILTIN_PREPROCESSOR; }
 static Key indexerFileSizeLimitKey() { return Constants::CPPEDITOR_INDEXER_FILE_SIZE_LIMIT; }
-
-static Key clangdSettingsKey() { return "ClangdSettings"; }
-static Key useClangdKey() { return "UseClangdV7"; }
-static Key clangdPathKey() { return "ClangdPath"; }
-static Key clangdIndexingKey() { return "ClangdIndexing"; }
-static Key clangdProjectIndexPathKey() { return "ClangdProjectIndexPath"; }
-static Key clangdSessionIndexPathKey() { return "ClangdSessionIndexPath"; }
-static Key clangdIndexingPriorityKey() { return "ClangdIndexingPriority"; }
-static Key clangdHeaderSourceSwitchModeKey() { return "ClangdHeaderSourceSwitchMode"; }
-static Key clangdCompletionRankingModelKey() { return "ClangdCompletionRankingModel"; }
-static Key clangdHeaderInsertionKey() { return "ClangdHeaderInsertion"; }
-static Key clangdThreadLimitKey() { return "ClangdThreadLimit"; }
-static Key clangdDocumentThresholdKey() { return "ClangdDocumentThreshold"; }
-static Key clangdSizeThresholdEnabledKey() { return "ClangdSizeThresholdEnabled"; }
-static Key clangdSizeThresholdKey() { return "ClangdSizeThreshold"; }
 static Key useGlobalSettingsKey() { return "useGlobalSettings"; }
-static Key clangdblockIndexingSettingsKey() { return "blockIndexing"; }
-static Key sessionsWithOneClangdKey() { return "SessionsWithOneClangd"; }
-static Key diagnosticConfigIdKey() { return "diagnosticConfigId"; }
-static Key checkedHardwareKey() { return "checkedHardware"; }
-static Key completionResultsKey() { return "completionResults"; }
-
-static FilePath g_defaultClangdFilePath;
-static FilePath fallbackClangdFilePath()
-{
-    if (g_defaultClangdFilePath.exists())
-        return g_defaultClangdFilePath;
-    return Environment::systemEnvironment().searchInPath("clangd");
-}
 
 bool operator==(const CppEditor::CppCodeModelSettings::Data &s1,
                 const CppEditor::CppCodeModelSettings::Data &s2)
@@ -230,440 +196,4 @@ void CppCodeModelProjectSettings::saveSettings()
     m_project->setNamedSettings(Constants::CPPEDITOR_SETTINGSGROUP, variantFromStore(data));
 }
 
-QString ClangdSettings::priorityToString(const IndexingPriority &priority)
-{
-    switch (priority) {
-    case IndexingPriority::Background: return "background";
-    case IndexingPriority::Normal: return "normal";
-    case IndexingPriority::Low: return "low";
-    case IndexingPriority::Off: return {};
-    }
-    return {};
-}
-
-QString ClangdSettings::priorityToDisplayString(const IndexingPriority &priority)
-{
-    switch (priority) {
-    case IndexingPriority::Background: return Tr::tr("Background Priority");
-    case IndexingPriority::Normal: return Tr::tr("Normal Priority");
-    case IndexingPriority::Low: return Tr::tr("Low Priority");
-    case IndexingPriority::Off: return Tr::tr("Off");
-    }
-    return {};
-}
-
-QString ClangdSettings::headerSourceSwitchModeToDisplayString(HeaderSourceSwitchMode mode)
-{
-    switch (mode) {
-    case HeaderSourceSwitchMode::BuiltinOnly: return Tr::tr("Use Built-in Only");
-    case HeaderSourceSwitchMode::ClangdOnly: return Tr::tr("Use Clangd Only");
-    case HeaderSourceSwitchMode::Both: return Tr::tr("Try Both");
-    }
-    return {};
-}
-
-QString ClangdSettings::rankingModelToCmdLineString(CompletionRankingModel model)
-{
-    switch (model) {
-    case CompletionRankingModel::Default: break;
-    case CompletionRankingModel::DecisionForest: return "decision_forest";
-    case CompletionRankingModel::Heuristics: return "heuristics";
-    }
-    QTC_ASSERT(false, return {});
-}
-
-QString ClangdSettings::rankingModelToDisplayString(CompletionRankingModel model)
-{
-    switch (model) {
-    case CompletionRankingModel::Default: return Tr::tr("Default");
-    case CompletionRankingModel::DecisionForest: return Tr::tr("Decision Forest");
-    case CompletionRankingModel::Heuristics: return Tr::tr("Heuristics");
-    }
-    QTC_ASSERT(false, return {});
-}
-
-QString ClangdSettings::defaultProjectIndexPathTemplate()
-{
-    return QDir::toNativeSeparators("%{BuildConfig:BuildDirectory:FilePath}/.qtc_clangd");
-}
-
-QString ClangdSettings::defaultSessionIndexPathTemplate()
-{
-    return QDir::toNativeSeparators("%{IDE:UserResourcePath}/.qtc_clangd/%{Session:FileBaseName}");
-}
-
-ClangdSettings &ClangdSettings::instance()
-{
-    static ClangdSettings settings;
-    return settings;
-}
-
-ClangdSettings::ClangdSettings()
-{
-    loadSettings();
-    const auto sessionMgr = Core::SessionManager::instance();
-    connect(sessionMgr, &Core::SessionManager::sessionRemoved, this, [this](const QString &name) {
-        m_data.sessionsWithOneClangd.removeOne(name);
-    });
-    connect(sessionMgr,
-            &Core::SessionManager::sessionRenamed,
-            this,
-            [this](const QString &oldName, const QString &newName) {
-                const auto index = m_data.sessionsWithOneClangd.indexOf(oldName);
-                if (index != -1)
-                    m_data.sessionsWithOneClangd[index] = newName;
-            });
-}
-
-bool ClangdSettings::useClangd() const
-{
-    return m_data.useClangd && clangdVersion(clangdFilePath()) >= minimumClangdVersion();
-}
-
-void ClangdSettings::setUseClangd(bool use) { instance().m_data.useClangd = use; }
-
-void ClangdSettings::setUseClangdAndSave(bool use)
-{
-    setUseClangd(use);
-    instance().saveSettings();
-}
-
-bool ClangdSettings::hardwareFulfillsRequirements()
-{
-    instance().m_data.haveCheckedHardwareReqirements = true;
-    instance().saveSettings();
-    const quint64 minRam = quint64(12) * 1024 * 1024 * 1024;
-    const std::optional<quint64> totalRam = Utils::HostOsInfo::totalMemoryInstalledInBytes();
-    return !totalRam || *totalRam >= minRam;
-}
-
-bool ClangdSettings::haveCheckedHardwareRequirements()
-{
-    return instance().data().haveCheckedHardwareReqirements;
-}
-
-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())
-        return m_data.executableFilePath;
-    return fallbackClangdFilePath();
-}
-
-FilePath ClangdSettings::projectIndexPath(const Utils::MacroExpander &expander) const
-{
-    return FilePath::fromUserInput(expander.expand(m_data.projectIndexPathTemplate));
-}
-
-FilePath ClangdSettings::sessionIndexPath(const Utils::MacroExpander &expander) const
-{
-    return FilePath::fromUserInput(expander.expand(m_data.sessionIndexPathTemplate));
-}
-
-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(Core::SessionManager::activeSession()))
-        return Granularity::Session;
-    return Granularity::Project;
-}
-
-void ClangdSettings::setData(const Data &data)
-{
-    if (this == &instance() && data != m_data) {
-        m_data = data;
-        saveSettings();
-        emit changed();
-    }
-}
-
-static FilePath getClangHeadersPathFromClang(const FilePath &clangdFilePath)
-{
-    const FilePath clangFilePath = clangdFilePath.absolutePath().pathAppended("clang")
-            .withExecutableSuffix();
-    if (!clangFilePath.exists())
-        return {};
-    Process clang;
-    clang.setCommand({clangFilePath, {"-print-resource-dir"}});
-    clang.start();
-    if (!clang.waitForFinished())
-        return {};
-    const FilePath resourceDir = FilePath::fromUserInput(QString::fromLocal8Bit(
-            clang.rawStdOut().trimmed()));
-    if (resourceDir.isEmpty() || !resourceDir.exists())
-        return {};
-    const FilePath includeDir = resourceDir.pathAppended("include");
-    if (!includeDir.exists())
-        return {};
-    return includeDir;
-}
-
-static FilePath getClangHeadersPath(const FilePath &clangdFilePath)
-{
-    const FilePath headersPath = getClangHeadersPathFromClang(clangdFilePath);
-    if (!headersPath.isEmpty())
-        return headersPath;
-
-    const QVersionNumber version = Utils::clangdVersion(clangdFilePath);
-    QTC_ASSERT(!version.isNull(), return {});
-    static const QStringList libDirs{"lib", "lib64"};
-    const QStringList versionStrings{QString::number(version.majorVersion()), version.toString()};
-    for (const QString &libDir : libDirs) {
-        for (const QString &versionString : versionStrings) {
-            const FilePath includePath = clangdFilePath.absolutePath().parentDir()
-                                             .pathAppended(libDir).pathAppended("clang")
-                                             .pathAppended(versionString).pathAppended("include");
-            if (includePath.exists())
-                return includePath;
-        }
-    }
-    QTC_CHECK(false);
-    return {};
-}
-
-FilePath ClangdSettings::clangdIncludePath() const
-{
-    QTC_ASSERT(useClangd(), return {});
-    FilePath clangdPath = clangdFilePath();
-    QTC_ASSERT(!clangdPath.isEmpty() && clangdPath.exists(), return {});
-    static QHash<FilePath, FilePath> headersPathCache;
-    const auto it = headersPathCache.constFind(clangdPath);
-    if (it != headersPathCache.constEnd())
-        return *it;
-    const FilePath headersPath = getClangHeadersPath(clangdPath);
-    if (!headersPath.isEmpty())
-        headersPathCache.insert(clangdPath, headersPath);
-    return headersPath;
-}
-
-FilePath ClangdSettings::clangdUserConfigFilePath()
-{
-    return FilePath::fromString(
-                QStandardPaths::writableLocation(QStandardPaths::GenericConfigLocation))
-            / "clangd/config.yaml";
-}
-
-void ClangdSettings::loadSettings()
-{
-    const auto settings = Core::ICore::settings();
-
-    m_data.fromMap(Utils::storeFromSettings(clangdSettingsKey(), settings));
-
-    settings->beginGroup(Constants::CPPEDITOR_SETTINGSGROUP);
-    m_data.customDiagnosticConfigs = diagnosticConfigsFromSettings(settings);
-
-    // Pre-8.0 compat
-    static const Key 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()
-{
-    const auto settings = Core::ICore::settings();
-    const ClangdSettings::Data defaultData;
-    Utils::storeToSettingsWithDefault(clangdSettingsKey(),
-                                      settings,
-                                      m_data.toMap(),
-                                      defaultData.toMap());
-    settings->beginGroup(Constants::CPPEDITOR_SETTINGSGROUP);
-    diagnosticConfigsToSettings(settings, m_data.customDiagnosticConfigs);
-    settings->endGroup();
-}
-
-#ifdef WITH_TESTS
-void ClangdSettings::setClangdFilePath(const FilePath &filePath)
-{
-    instance().m_data.executableFilePath = filePath;
-}
-#endif
-
-ClangdProjectSettings::ClangdProjectSettings(ProjectExplorer::Project *project) : m_project(project)
-{
-    loadSettings();
-}
-
-ClangdSettings::Data ClangdProjectSettings::settings() const
-{
-    const ClangdSettings::Data globalData = ClangdSettings::instance().data();
-    ClangdSettings::Data data = globalData;
-    if (!m_useGlobalSettings) {
-        data = m_customSettings;
-    // This property is global by definition.
-    data.sessionsWithOneClangd = ClangdSettings::instance().data().sessionsWithOneClangd;
-
-    // This list exists only once.
-    data.customDiagnosticConfigs = ClangdSettings::instance().data().customDiagnosticConfigs;
-}
-    if (m_blockIndexing)
-        data.indexingPriority = ClangdSettings::IndexingPriority::Off;
-    return data;
-}
-
-void ClangdProjectSettings::setSettings(const ClangdSettings::Data &data)
-{
-    m_customSettings = data;
-    saveSettings();
-    ClangdSettings::setCustomDiagnosticConfigs(data.customDiagnosticConfigs);
-    emit ClangdSettings::instance().changed();
-}
-
-void ClangdProjectSettings::setUseGlobalSettings(bool useGlobal)
-{
-    m_useGlobalSettings = useGlobal;
-    saveSettings();
-    emit ClangdSettings::instance().changed();
-}
-
-void ClangdProjectSettings::setDiagnosticConfigId(Utils::Id configId)
-{
-    m_customSettings.diagnosticConfigId = configId;
-    saveSettings();
-    emit ClangdSettings::instance().changed();
-}
-
-void ClangdProjectSettings::blockIndexing()
-{
-    if (m_blockIndexing)
-        return;
-    m_blockIndexing = true;
-    saveSettings();
-    emit ClangdSettings::instance().changed();
-}
-
-void ClangdProjectSettings::unblockIndexing()
-{
-    if (!m_blockIndexing)
-        return;
-    m_blockIndexing = false;
-    saveSettings();
-    // Do not emit changed here since that would restart clients with blocked indexing
-}
-
-void ClangdProjectSettings::loadSettings()
-{
-    if (!m_project)
-        return;
-    const Store data = storeFromVariant(m_project->namedSettings(clangdSettingsKey()));
-    m_useGlobalSettings = data.value(useGlobalSettingsKey(), true).toBool();
-    m_blockIndexing = data.value(clangdblockIndexingSettingsKey(), false).toBool();
-    if (!m_useGlobalSettings)
-        m_customSettings.fromMap(data);
-}
-
-void ClangdProjectSettings::saveSettings()
-{
-    if (!m_project)
-        return;
-    Store data;
-    if (!m_useGlobalSettings)
-        data = m_customSettings.toMap();
-    data.insert(useGlobalSettingsKey(), m_useGlobalSettings);
-    data.insert(clangdblockIndexingSettingsKey(), m_blockIndexing);
-    m_project->setNamedSettings(clangdSettingsKey(), variantFromStore(data));
-}
-
-Store ClangdSettings::Data::toMap() const
-{
-    Store map;
-
-    map.insert(useClangdKey(), useClangd);
-
-    map.insert(clangdPathKey(),
-               executableFilePath != fallbackClangdFilePath() ? executableFilePath.toString()
-                                                              : QString());
-
-    map.insert(clangdIndexingKey(), indexingPriority != IndexingPriority::Off);
-    map.insert(clangdIndexingPriorityKey(), int(indexingPriority));
-    map.insert(clangdProjectIndexPathKey(), projectIndexPathTemplate);
-    map.insert(clangdSessionIndexPathKey(), sessionIndexPathTemplate);
-    map.insert(clangdHeaderSourceSwitchModeKey(), int(headerSourceSwitchMode));
-    map.insert(clangdCompletionRankingModelKey(), int(completionRankingModel));
-    map.insert(clangdHeaderInsertionKey(), autoIncludeHeaders);
-    map.insert(clangdThreadLimitKey(), workerThreadLimit);
-    map.insert(clangdDocumentThresholdKey(), documentUpdateThreshold);
-    map.insert(clangdSizeThresholdEnabledKey(), sizeThresholdEnabled);
-    map.insert(clangdSizeThresholdKey(), sizeThresholdInKb);
-    map.insert(sessionsWithOneClangdKey(), sessionsWithOneClangd);
-    map.insert(diagnosticConfigIdKey(), diagnosticConfigId.toSetting());
-    map.insert(checkedHardwareKey(), haveCheckedHardwareReqirements);
-    map.insert(completionResultsKey(), completionResults);
-    return map;
-}
-
-void ClangdSettings::Data::fromMap(const Store &map)
-{
-    useClangd = map.value(useClangdKey(), true).toBool();
-    executableFilePath = FilePath::fromString(map.value(clangdPathKey()).toString());
-    indexingPriority = IndexingPriority(
-        map.value(clangdIndexingPriorityKey(), int(this->indexingPriority)).toInt());
-    const auto it = map.find(clangdIndexingKey());
-    if (it != map.end() && !it->toBool())
-        indexingPriority = IndexingPriority::Off;
-    projectIndexPathTemplate
-        = map.value(clangdProjectIndexPathKey(), defaultProjectIndexPathTemplate()).toString();
-    sessionIndexPathTemplate
-        = map.value(clangdSessionIndexPathKey(), defaultSessionIndexPathTemplate()).toString();
-    headerSourceSwitchMode = HeaderSourceSwitchMode(map.value(clangdHeaderSourceSwitchModeKey(),
-                                                              int(headerSourceSwitchMode)).toInt());
-    completionRankingModel = CompletionRankingModel(map.value(clangdCompletionRankingModelKey(),
-                                                              int(completionRankingModel)).toInt());
-    autoIncludeHeaders = map.value(clangdHeaderInsertionKey(), false).toBool();
-    workerThreadLimit = map.value(clangdThreadLimitKey(), 0).toInt();
-    documentUpdateThreshold = map.value(clangdDocumentThresholdKey(), 500).toInt();
-    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()));
-    haveCheckedHardwareReqirements = map.value(checkedHardwareKey(), false).toBool();
-    completionResults = map.value(completionResultsKey(), defaultCompletionResults()).toInt();
-}
-
-int ClangdSettings::Data::defaultCompletionResults()
-{
-    // Default clangd --limit-results value is 100
-    bool ok = false;
-    const int userValue = qtcEnvironmentVariableIntValue("QTC_CLANGD_COMPLETION_RESULTS", &ok);
-    return ok ? userValue : 100;
-}
-
 } // namespace CppEditor
diff --git a/src/plugins/cppeditor/cppcodemodelsettings.h b/src/plugins/cppeditor/cppcodemodelsettings.h
index 19cc078b26..0bd9b05fbd 100644
--- a/src/plugins/cppeditor/cppcodemodelsettings.h
+++ b/src/plugins/cppeditor/cppcodemodelsettings.h
@@ -3,10 +3,8 @@
 
 #pragma once
 
-#include "clangdiagnosticconfig.h"
 #include "cppeditor_global.h"
 
-#include <utils/clangutils.h>
 #include <utils/filepath.h>
 #include <utils/id.h>
 #include <utils/store.h>
@@ -14,12 +12,8 @@
 
 #include <QObject>
 #include <QStringList>
-#include <QVersionNumber>
 
 namespace ProjectExplorer { class Project; }
-namespace Utils {
-class MacroExpander;
-} // namespace Utils
 
 namespace CppEditor {
 enum class UsePrecompiledHeaders;
@@ -114,148 +108,4 @@ private:
     bool m_useGlobalSettings = true;
 };
 
-class CPPEDITOR_EXPORT ClangdSettings : public QObject
-{
-    Q_OBJECT
-public:
-    enum class IndexingPriority { Off, Background, Normal, Low, };
-    enum class HeaderSourceSwitchMode { BuiltinOnly, ClangdOnly, Both };
-    enum class CompletionRankingModel { Default, DecisionForest, Heuristics };
-
-    static QString priorityToString(const IndexingPriority &priority);
-    static QString priorityToDisplayString(const IndexingPriority &priority);
-    static QString headerSourceSwitchModeToDisplayString(HeaderSourceSwitchMode mode);
-    static QString rankingModelToCmdLineString(CompletionRankingModel model);
-    static QString rankingModelToDisplayString(CompletionRankingModel model);
-    static QString defaultProjectIndexPathTemplate();
-    static QString defaultSessionIndexPathTemplate();
-
-    class CPPEDITOR_EXPORT Data
-    {
-    public:
-        Utils::Store toMap() const;
-        void fromMap(const Utils::Store &map);
-
-        friend bool operator==(const Data &s1, const Data &s2)
-        {
-            return s1.useClangd == s2.useClangd
-                    && s1.executableFilePath == s2.executableFilePath
-                    && s1.projectIndexPathTemplate == s2.projectIndexPathTemplate
-                    && s1.sessionIndexPathTemplate == s2.sessionIndexPathTemplate
-                    && s1.sessionsWithOneClangd == s2.sessionsWithOneClangd
-                    && s1.customDiagnosticConfigs == s2.customDiagnosticConfigs
-                    && s1.diagnosticConfigId == s2.diagnosticConfigId
-                    && s1.workerThreadLimit == s2.workerThreadLimit
-                    && s1.indexingPriority == s2.indexingPriority
-                    && s1.headerSourceSwitchMode == s2.headerSourceSwitchMode
-                    && s1.completionRankingModel == s2.completionRankingModel
-                    && s1.autoIncludeHeaders == s2.autoIncludeHeaders
-                    && s1.documentUpdateThreshold == s2.documentUpdateThreshold
-                    && s1.sizeThresholdEnabled == s2.sizeThresholdEnabled
-                    && s1.sizeThresholdInKb == s2.sizeThresholdInKb
-                    && s1.haveCheckedHardwareReqirements == s2.haveCheckedHardwareReqirements
-                    && s1.completionResults == s2.completionResults;
-        }
-        friend bool operator!=(const Data &s1, const Data &s2) { return !(s1 == s2); }
-
-        Utils::FilePath executableFilePath;
-        QStringList sessionsWithOneClangd;
-        ClangDiagnosticConfigs customDiagnosticConfigs;
-        Utils::Id diagnosticConfigId;
-
-        int workerThreadLimit = 0;
-        int documentUpdateThreshold = 500;
-        qint64 sizeThresholdInKb = 1024;
-        bool useClangd = true;
-        IndexingPriority indexingPriority = IndexingPriority::Low;
-        QString projectIndexPathTemplate = defaultProjectIndexPathTemplate();
-        QString sessionIndexPathTemplate = defaultSessionIndexPathTemplate();
-        HeaderSourceSwitchMode headerSourceSwitchMode = HeaderSourceSwitchMode::Both;
-        CompletionRankingModel completionRankingModel = CompletionRankingModel::Default;
-        bool autoIncludeHeaders = false;
-        bool sizeThresholdEnabled = false;
-        bool haveCheckedHardwareReqirements = false;
-        int completionResults = defaultCompletionResults();
-
-    private:
-        static int defaultCompletionResults();
-    };
-
-    ClangdSettings(const Data &data) : m_data(data) {}
-
-    static ClangdSettings &instance();
-    bool useClangd() const;
-    static void setUseClangd(bool use);
-    static void setUseClangdAndSave(bool use);
-
-    static bool hardwareFulfillsRequirements();
-    static bool haveCheckedHardwareRequirements();
-
-    static void setDefaultClangdPath(const Utils::FilePath &filePath);
-    static void setCustomDiagnosticConfigs(const ClangDiagnosticConfigs &configs);
-    Utils::FilePath clangdFilePath() const;
-    IndexingPriority indexingPriority() const { return m_data.indexingPriority; }
-    Utils::FilePath projectIndexPath(const Utils::MacroExpander &expander) const;
-    Utils::FilePath sessionIndexPath(const Utils::MacroExpander &expander) const;
-    HeaderSourceSwitchMode headerSourceSwitchMode() const { return m_data.headerSourceSwitchMode; }
-    CompletionRankingModel completionRankingModel() const { return m_data.completionRankingModel; }
-    bool autoIncludeHeaders() const { return m_data.autoIncludeHeaders; }
-    int workerThreadLimit() const { return m_data.workerThreadLimit; }
-    int documentUpdateThreshold() const { return m_data.documentUpdateThreshold; }
-    qint64 sizeThresholdInKb() const { return m_data.sizeThresholdInKb; }
-    bool sizeThresholdEnabled() const { return m_data.sizeThresholdEnabled; }
-    int completionResults() const { return m_data.completionResults; }
-    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;
-
-    void setData(const Data &data);
-    Data data() const { return m_data; }
-
-    Utils::FilePath clangdIncludePath() const;
-    static Utils::FilePath clangdUserConfigFilePath();
-
-#ifdef WITH_TESTS
-    static void setClangdFilePath(const Utils::FilePath &filePath);
-#endif
-
-signals:
-    void changed();
-
-private:
-    ClangdSettings();
-
-    void loadSettings();
-    void saveSettings();
-
-    Data m_data;
-};
-
-class CPPEDITOR_EXPORT ClangdProjectSettings
-{
-public:
-    ClangdProjectSettings(ProjectExplorer::Project *project);
-
-    ClangdSettings::Data settings() const;
-    void setSettings(const ClangdSettings::Data &data);
-    bool useGlobalSettings() const { return m_useGlobalSettings; }
-    void setUseGlobalSettings(bool useGlobal);
-    void setDiagnosticConfigId(Utils::Id configId);
-    void blockIndexing();
-    void unblockIndexing();
-
-private:
-    void loadSettings();
-    void saveSettings();
-
-    ProjectExplorer::Project * const m_project;
-    ClangdSettings::Data m_customSettings;
-    bool m_useGlobalSettings = true;
-    bool m_blockIndexing = false;
-};
-
 } // namespace CppEditor
diff --git a/src/plugins/cppeditor/cppcodemodelsettingspage.cpp b/src/plugins/cppeditor/cppcodemodelsettingspage.cpp
index 616bb34f61..0e880fcb55 100644
--- a/src/plugins/cppeditor/cppcodemodelsettingspage.cpp
+++ b/src/plugins/cppeditor/cppcodemodelsettingspage.cpp
@@ -5,6 +5,7 @@
 
 #include "clangdiagnosticconfigsselectionwidget.h"
 #include "clangdiagnosticconfigswidget.h"
+#include "clangdsettings.h"
 #include "cppcodemodelsettings.h"
 #include "cppeditorconstants.h"
 #include "cppeditortr.h"
@@ -18,6 +19,7 @@
 #include <projectexplorer/projectsettingswidget.h>
 
 #include <utils/algorithm.h>
+#include <utils/clangutils.h>
 #include <utils/fancylineedit.h>
 #include <utils/infolabel.h>
 #include <utils/itemviews.h>
diff --git a/src/plugins/cppeditor/cppeditor.qbs b/src/plugins/cppeditor/cppeditor.qbs
index b684b0e0ea..b805e3fae9 100644
--- a/src/plugins/cppeditor/cppeditor.qbs
+++ b/src/plugins/cppeditor/cppeditor.qbs
@@ -45,6 +45,8 @@ QtcPlugin {
         "clangdiagnosticconfigsselectionwidget.h",
         "clangdiagnosticconfigswidget.cpp",
         "clangdiagnosticconfigswidget.h",
+        "clangdsettings.cpp",
+        "clangdsettings.h",
         "compileroptionsbuilder.cpp",
         "compileroptionsbuilder.h",
         "cppautocompleter.cpp",
diff --git a/src/plugins/cppeditor/cpptoolsreuse.cpp b/src/plugins/cppeditor/cpptoolsreuse.cpp
index f6e58abddf..947ecdd4c6 100644
--- a/src/plugins/cppeditor/cpptoolsreuse.cpp
+++ b/src/plugins/cppeditor/cpptoolsreuse.cpp
@@ -4,6 +4,7 @@
 #include "cpptoolsreuse.h"
 
 #include "clangdiagnosticconfigsmodel.h"
+#include "clangdsettings.h"
 #include "cppautocompleter.h"
 #include "cppcanonicalsymbol.h"
 #include "cppcodemodelsettings.h"
diff --git a/src/plugins/cppeditor/followsymbol_switchmethoddecldef_test.cpp b/src/plugins/cppeditor/followsymbol_switchmethoddecldef_test.cpp
index 9bef50b0b8..41dd6b538f 100644
--- a/src/plugins/cppeditor/followsymbol_switchmethoddecldef_test.cpp
+++ b/src/plugins/cppeditor/followsymbol_switchmethoddecldef_test.cpp
@@ -3,6 +3,7 @@
 
 #include "followsymbol_switchmethoddecldef_test.h"
 
+#include "clangdsettings.h"
 #include "cppcodemodelsettings.h"
 #include "cppeditorwidget.h"
 #include "cppfollowsymbolundercursor.h"