From d7c7089ff3ff2877fe89ac09cc2afa9a3da041c0 Mon Sep 17 00:00:00 2001
From: Christian Kandeler <christian.kandeler@qt.io>
Date: Wed, 20 Oct 2021 11:41:38 +0200
Subject: [PATCH] ClangCodeModel: Restart clangd fallback client

... on fallback project part change.

Change-Id: Icfc355443b4d6bb3c94eae27c2d23bbd9f681211
Reviewed-by: David Schulz <david.schulz@qt.io>
---
 .../clangmodelmanagersupport.cpp              |  6 +++++
 src/plugins/cppeditor/cppmodelmanager.cpp     | 24 ++++++++++++-------
 src/plugins/cppeditor/cppmodelmanager.h       |  1 +
 3 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp b/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
index d1c6b0d0ce3..c06d8a8fff7 100644
--- a/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
+++ b/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
@@ -134,6 +134,12 @@ ClangModelManagerSupport::ClangModelManagerSupport()
             this, &ClangModelManagerSupport::onProjectPartsUpdated);
     connect(modelManager, &CppEditor::CppModelManager::projectPartsRemoved,
             this, &ClangModelManagerSupport::onProjectPartsRemoved);
+    connect(modelManager, &CppModelManager::fallbackProjectPartUpdated, this, [this] {
+        if (ClangdClient * const fallbackClient = clientForProject(nullptr)) {
+            LanguageClientManager::shutdownClient(fallbackClient);
+            claimNonProjectSources(createClient(nullptr, {}));
+        }
+    });
 
     auto *sessionManager = ProjectExplorer::SessionManager::instance();
     connect(sessionManager, &ProjectExplorer::SessionManager::projectAdded,
diff --git a/src/plugins/cppeditor/cppmodelmanager.cpp b/src/plugins/cppeditor/cppmodelmanager.cpp
index 4ddd690b42a..b87e1098da1 100644
--- a/src/plugins/cppeditor/cppmodelmanager.cpp
+++ b/src/plugins/cppeditor/cppmodelmanager.cpp
@@ -196,6 +196,7 @@ public:
 
     bool m_enableGC;
     QTimer m_delayedGcTimer;
+    QTimer m_fallbackProjectPartTimer;
 
     // Refactoring
     using REHash = QMap<REType, RefactoringEngineInterface *>;
@@ -692,12 +693,16 @@ CppModelManager::CppModelManager()
     connect(Core::ICore::instance(), &Core::ICore::coreAboutToClose,
             this, &CppModelManager::onCoreAboutToClose);
 
-    connect(KitManager::instance(), &KitManager::kitsChanged, this,
-            &CppModelManager::setupFallbackProjectPart);
-    connect(this, &CppModelManager::projectPartsRemoved, this,
-            &CppModelManager::setupFallbackProjectPart);
-    connect(this, &CppModelManager::projectPartsUpdated, this,
-            &CppModelManager::setupFallbackProjectPart);
+    d->m_fallbackProjectPartTimer.setSingleShot(true);
+    d->m_fallbackProjectPartTimer.setInterval(5000);
+    connect(&d->m_fallbackProjectPartTimer, &QTimer::timeout,
+            this, &CppModelManager::setupFallbackProjectPart);
+    connect(KitManager::instance(), &KitManager::kitsChanged,
+            &d->m_fallbackProjectPartTimer, qOverload<>(&QTimer::start));
+    connect(this, &CppModelManager::projectPartsRemoved,
+            &d->m_fallbackProjectPartTimer, qOverload<>(&QTimer::start));
+    connect(this, &CppModelManager::projectPartsUpdated,
+            &d->m_fallbackProjectPartTimer, qOverload<>(&QTimer::start));
     setupFallbackProjectPart();
 
     qRegisterMetaType<CPlusPlus::Document::Ptr>("CPlusPlus::Document::Ptr");
@@ -1581,8 +1586,11 @@ void CppModelManager::setupFallbackProjectPart()
     }
 
     const auto part = ProjectPart::create({}, rpp, {}, {}, {}, langExtensions, {}, tcInfo);
-    QMutexLocker locker(&d->m_fallbackProjectPartMutex);
-    d->m_fallbackProjectPart = part;
+    {
+        QMutexLocker locker(&d->m_fallbackProjectPartMutex);
+        d->m_fallbackProjectPart = part;
+    }
+    emit fallbackProjectPartUpdated();
 }
 
 void CppModelManager::GC()
diff --git a/src/plugins/cppeditor/cppmodelmanager.h b/src/plugins/cppeditor/cppmodelmanager.h
index 3a05368e15a..e6dc746a1f1 100644
--- a/src/plugins/cppeditor/cppmodelmanager.h
+++ b/src/plugins/cppeditor/cppmodelmanager.h
@@ -263,6 +263,7 @@ signals:
                                               const QString &sourcePath,
                                               const QByteArray &contents);
     void abstractEditorSupportRemoved(const QString &filePath);
+    void fallbackProjectPartUpdated();
 
 public slots:
     void updateModifiedSourceFiles();