ClangCodeModel: Inform clangd about changes to non-open files

That is, project-wide changes done from Qt Creator, such as search/
replace or quickfixes.

Fixes: QTCREATORBUG-26523
Change-Id: Ide4e56a7a1300eb6f25cabf1cfd94624d66e7e4e
Reviewed-by: David Schulz <david.schulz@qt.io>

2 files changed, 25 insertions, 1 deletions

diff --git a/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp b/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
index 090a4549c3..3bd9d2640f 100644
--- a/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
+++ b/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
@@ -112,6 +112,7 @@ ClangModelManagerSupport::ClangModelManagerSupport()
     m_instance = this;
 
     watchForExternalChanges();
+    watchForInternalChanges();
     cppModelManager()->setCurrentDocumentFilter(std::make_unique<ClangdCurrentDocumentFilter>());
     cppModelManager()->setLocatorFilter(std::make_unique<ClangGlobalSymbolFilter>());
     cppModelManager()->setClassesFilter(std::make_unique<ClangClassesFilter>());
@@ -488,6 +489,29 @@ void ClangModelManagerSupport::watchForExternalChanges()
     });
 }
 
+void ClangModelManagerSupport::watchForInternalChanges()
+{
+    connect(Core::DocumentManager::instance(), &Core::DocumentManager::filesChangedInternally,
+            this, [this](const Utils::FilePaths &filePaths) {
+        for (const Utils::FilePath &fp : filePaths) {
+            ClangdClient * const client = clientForFile(fp);
+            if (!client || client->documentForFilePath(fp))
+                continue;
+            client->openExtraFile(fp);
+
+            // We need to give clangd some time to start re-parsing the file.
+            // Closing right away does not work, and neither does doing it queued.
+            // If it turns out that this delay is not always enough, we'll need to come up
+            // with something more clever.
+            // Ideally, clangd would implement workspace/didChangeWatchedFiles; let's keep
+            // any eye on that.
+            QTimer::singleShot(5000, client, [client, fp] {
+                if (!client->documentForFilePath(fp))
+                    client->closeExtraFile(fp); });
+        }
+    });
+}
+
 void ClangModelManagerSupport::onEditorOpened(Core::IEditor *editor)
 {
     QTC_ASSERT(editor, return);
diff --git a/src/plugins/clangcodemodel/clangmodelmanagersupport.h b/src/plugins/clangcodemodel/clangmodelmanagersupport.h
index fc4e1d1a4b..5d591d6925 100644
--- a/src/plugins/clangcodemodel/clangmodelmanagersupport.h
+++ b/src/plugins/clangcodemodel/clangmodelmanagersupport.h
@@ -135,8 +135,8 @@ private:
     ClangdClient *createClient(ProjectExplorer::Project *project, const Utils::FilePath &jsonDbDir);
     void claimNonProjectSources(ClangdClient *fallbackClient);
     void watchForExternalChanges();
+    void watchForInternalChanges();
 
-private:
     UiHeaderOnDiskManager m_uiHeaderOnDiskManager;
     BackendCommunicator m_communicator;
     ClangCompletionAssistProvider m_completionAssistProvider;