Remove issue where diagnostics would disappear file saves.

Also allow rebuilding of completion session by closing and reopening a
file.

src/clang_complete.cc

@@ -303,6 +303,12 @@ void EnsureDocumentParsed(ClangCompleteManager* manager,
 
   // Build diagnostics.
   if (manager->config_->diagnosticsOnParse && !(*tu)->did_fail) {
+    // If we're emitting diagnostics, do an immedaite reparse, otherwise we will
+    // emit stale/bad diagnostics.
+    clang_reparseTranslationUnit(
+        (*tu)->cx_tu, unsaved.size(), unsaved.data(),
+        clang_defaultReparseOptions((*tu)->cx_tu));
+
     NonElidedVector<lsDiagnostic> ls_diagnostics;
     unsigned num_diagnostics = clang_getNumDiagnostics((*tu)->cx_tu);
     for (unsigned i = 0; i < num_diagnostics; ++i) {
@@ -360,9 +366,10 @@ void CompletionQueryMain(ClangCompleteManager* completion_manager) {
         completion_manager->TryGetSession(path, true /*create_if_needed*/);
 
     std::lock_guard<std::mutex> lock(session->tu_lock);
+    Timer timer;
     EnsureDocumentParsed(completion_manager, session, &session->tu,
                          &session->index);
-    Timer timer;
+    timer.ResetAndPrint("[complete] EnsureDocumentParsed");
 
     std::vector<CXUnsavedFile> unsaved =
         completion_manager->working_files_->AsUnsavedFiles();
@@ -631,6 +638,23 @@ void ClangCompleteManager::NotifySave(const std::string& filename) {
   parse_requests_.PriorityEnqueue(ParseRequest(filename));
 }
 
+void ClangCompleteManager::NotifyClose(const std::string& filename) {
+  //
+  // On close, we clear any existing CompletionSession instance.
+  //
+
+  std::lock_guard<std::mutex> lock(sessions_lock_);
+
+  // Take and drop. It's okay if we don't actually drop the file, it'll
+  // eventually get pushed out of the caches as the user opens other files.
+  auto view_ptr = view_sessions_.TryTakeEntry(filename);
+  LOG_IF_S(INFO, !!view_ptr)
+      << "Dropped view-based code completion session for " << filename;
+  auto edit_ptr = edit_sessions_.TryTakeEntry(filename);
+  LOG_IF_S(INFO, !!edit_ptr)
+      << "Dropped edit-based code completion session for " << filename;
+}
+
 std::shared_ptr<CompletionSession> ClangCompleteManager::TryGetSession(
     const std::string& filename,
     bool create_if_needed) {

src/clang_complete.h

@@ -95,6 +95,9 @@ struct ClangCompleteManager {
   // Notify the completion manager that |filename| has been saved. This
   // triggers a reparse.
   void NotifySave(const std::string& filename);
+  // Notify the completion manager that |filename| has been closed. Any existing
+  // completion session will be dropped.
+  void NotifyClose(const std::string& filename);
 
   std::shared_ptr<CompletionSession> TryGetSession(const std::string& filename,
                                                    bool create_if_needed);

src/command_line.cc

@@ -1765,6 +1765,7 @@ bool QueryDbMainLoop(Config* config,
 
       case IpcId::TextDocumentDidClose: {
         auto msg = message->As<Ipc_TextDocumentDidClose>();
+        std::string path = msg->params.textDocument.uri.GetPath();
 
         // Clear any diagnostics for the file.
         Out_TextDocumentPublishDiagnostics diag;
@@ -1774,6 +1775,7 @@ bool QueryDbMainLoop(Config* config,
 
         // Remove internal state.
         working_files->OnClose(msg->params);
+        clang_complete->NotifyClose(path);
 
         break;
       }