Clangd: Handle settings changes

Users no longer have to re-load a project for settings changes to take
effect.

Change-Id: I86dccccac14a30514c8dac292c7765ee4806f6ba
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/clangcodemodel/clangdclient.cpp

@@ -33,7 +33,6 @@
 #include <coreplugin/find/searchresultitem.h>
 #include <coreplugin/find/searchresultwindow.h>
 #include <cplusplus/FindUsages.h>
-#include <cpptools/cppcodemodelsettings.h>
 #include <cpptools/cppeditorwidgetinterface.h>
 #include <cpptools/cppfindreferences.h>
 #include <cpptools/cpptoolsreuse.h>
@@ -419,7 +418,7 @@ public:
 static BaseClientInterface *clientInterface(Project *project, const Utils::FilePath &jsonDbDir)
 {
     QString indexingOption = "--background-index";
-    const CppTools::ClangdSettings settings = CppTools::ClangdProjectSettings(project).settings();
+    const CppTools::ClangdSettings settings(CppTools::ClangdProjectSettings(project).settings());
     if (!settings.indexingEnabled())
         indexingOption += "=0";
     Utils::CommandLine cmd{settings.clangdFilePath(), {indexingOption, "--limit-results=0"}};
@@ -661,7 +660,8 @@ public:
 class ClangdClient::Private
 {
 public:
-    Private(ClangdClient *q) : q(q) {}
+    Private(ClangdClient *q, Project *project)
+        : q(q), settings(CppTools::ClangdProjectSettings(project).settings()) {}
 
     void handleFindUsagesResult(quint64 key, const QList<Location> &locations);
     static void handleRenameRequest(const SearchResult *search,
@@ -689,6 +689,7 @@ public:
                                const QString &type = {});
 
     ClangdClient * const q;
+    const CppTools::ClangdSettings::Data settings;
     QHash<quint64, ReferencesData> runningFindUsages;
     Utils::optional<FollowSymbolData> followSymbolData;
     Utils::optional<SwitchDeclDefData> switchDeclDefData;
@@ -700,7 +701,7 @@ public:
 };
 
 ClangdClient::ClangdClient(Project *project, const Utils::FilePath &jsonDbDir)
-    : Client(clientInterface(project, jsonDbDir)), d(new Private(this))
+    : Client(clientInterface(project, jsonDbDir)), d(new Private(this, project))
 {
     setName(tr("clangd"));
     LanguageFilter langFilter;
@@ -900,6 +901,8 @@ QVersionNumber ClangdClient::versionNumber() const
     return d->versionNumber.value();
 }
 
+CppTools::ClangdSettings::Data ClangdClient::settingsData() const { return d->settings; }
+
 void ClangdClient::Private::handleFindUsagesResult(quint64 key, const QList<Location> &locations)
 {
     const auto refData = runningFindUsages.find(key);

src/plugins/clangcodemodel/clangdclient.h

@@ -25,6 +25,7 @@
 
 #pragma once
 
+#include <cpptools/cppcodemodelsettings.h>
 #include <cpptools/refactoringengineinterface.h>
 #include <languageclient/client.h>
 #include <utils/link.h>
@@ -49,6 +50,7 @@ public:
 
     bool isFullyIndexed() const;
     QVersionNumber versionNumber() const;
+    CppTools::ClangdSettings::Data settingsData() const;
 
     void openExtraFile(const Utils::FilePath &filePath, const QString &content = {});
     void closeExtraFile(const Utils::FilePath &filePath);

src/plugins/clangcodemodel/clangmodelmanagersupport.cpp

@@ -122,6 +122,8 @@ ClangModelManagerSupport::ClangModelManagerSupport()
 
     CppTools::ClangdSettings::setDefaultClangdPath(Utils::FilePath::fromString(
             Core::ICore::clangdExecutable(CLANG_BINDIR)));
+    connect(&CppTools::ClangdSettings::instance(), &CppTools::ClangdSettings::changed,
+            this, &ClangModelManagerSupport::onClangdSettingsChanged);
     CppTools::CppCodeModelSettings *settings = CppTools::codeModelSettings();
     connect(settings, &CppTools::CppCodeModelSettings::clangDiagnosticConfigsInvalidated,
             this, &ClangModelManagerSupport::onDiagnosticConfigsInvalidated);
@@ -247,7 +249,7 @@ void ClangModelManagerSupport::connectToWidgetsMarkContextMenuRequested(QWidget
 void ClangModelManagerSupport::updateLanguageClient(ProjectExplorer::Project *project,
                                                     const CppTools::ProjectInfo &projectInfo)
 {
-    if (!CppTools::ClangdProjectSettings(project).settings().useClangd())
+    if (!CppTools::ClangdProjectSettings(project).settings().useClangd)
         return;
     const auto getJsonDbDir = [project] {
         if (const ProjectExplorer::Target * const target = project->activeTarget()) {
@@ -268,7 +270,7 @@ void ClangModelManagerSupport::updateLanguageClient(ProjectExplorer::Project *pr
         generatorWatcher->deleteLater();
         if (!ProjectExplorer::SessionManager::hasProject(project))
             return;
-        if (!CppTools::ClangdProjectSettings(project).settings().useClangd())
+        if (!CppTools::ClangdProjectSettings(project).settings().useClangd)
             return;
         if (cppModelManager()->projectInfo(project) != projectInfo)
             return;
@@ -288,7 +290,7 @@ void ClangModelManagerSupport::updateLanguageClient(ProjectExplorer::Project *pr
             using namespace ProjectExplorer;
             if (!SessionManager::hasProject(project))
                 return;
-            if (!CppTools::ClangdProjectSettings(project).settings().useClangd())
+            if (!CppTools::ClangdProjectSettings(project).settings().useClangd)
                 return;
             if (cppModelManager()->projectInfo(project) != projectInfo)
                 return;
@@ -587,6 +589,27 @@ void ClangModelManagerSupport::onProjectPartsRemoved(const QStringList &projectP
         reinitializeBackendDocuments(projectPartIds);
 }
 
+void ClangModelManagerSupport::onClangdSettingsChanged()
+{
+    // TODO: Handle also project-less client
+    for (ProjectExplorer::Project * const project : ProjectExplorer::SessionManager::projects()) {
+        const CppTools::ClangdSettings settings(
+                    CppTools::ClangdProjectSettings(project).settings());
+        ClangdClient * const client = clientForProject(project);
+        if (!client) {
+            if (settings.useClangd())
+                updateLanguageClient(project, cppModelManager()->projectInfo(project));
+            continue;
+        }
+        if (!settings.useClangd()) {
+            LanguageClientManager::shutdownClient(client);
+            continue;
+        }
+        if (client->settingsData() != settings.data())
+            updateLanguageClient(project, cppModelManager()->projectInfo(project));
+    }
+}
+
 static ClangEditorDocumentProcessors clangProcessorsWithDiagnosticConfig(
     const QVector<::Utils::Id> &configIds)
 {

src/plugins/clangcodemodel/clangmodelmanagersupport.h

@@ -114,6 +114,7 @@ private:
 
     void onProjectPartsUpdated(ProjectExplorer::Project *project);
     void onProjectPartsRemoved(const QStringList &projectPartIds);
+    void onClangdSettingsChanged();
 
     void onDiagnosticConfigsInvalidated(const QVector<::Utils::Id> &configIds);