CodeAssistant: add cancel to asynchronous processors

Fixes crash when the processor reports a result after the code assistant
was destroyed.

Change-Id: I8588d3d6acad69f1ec6302e8ba09d642ebbb77f1
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/languageclient/languageclientcompletionassist.cpp

@@ -278,13 +278,14 @@ public:
     IAssistProposal *perform(const AssistInterface *interface) override;
     bool running() override;
     bool needsRestart() const override { return true; }
+    void cancel() override;
 
 private:
     void handleCompletionResponse(const CompletionRequest::Response &response);
 
     QPointer<QTextDocument> m_document;
     QPointer<Client> m_client;
-    bool m_running = false;
+    MessageId m_currentRequest;
     int m_pos = -1;
 };
 
@@ -336,7 +337,7 @@ IAssistProposal *LanguageClientCompletionAssistProcessor::perform(const AssistIn
     });
     completionRequest.setParams(params);
     m_client->sendContent(completionRequest);
-    m_running = true;
+    m_currentRequest = completionRequest.id();
     m_document = interface->textDocument();
     qCDebug(LOGLSPCOMPLETION) << QTime::currentTime()
                               << " : request completions at " << m_pos
@@ -346,14 +347,22 @@ IAssistProposal *LanguageClientCompletionAssistProcessor::perform(const AssistIn
 
 bool LanguageClientCompletionAssistProcessor::running()
 {
-    return m_running;
+    return m_currentRequest.isValid();
+}
+
+void LanguageClientCompletionAssistProcessor::cancel()
+{
+    if (running()) {
+        m_client->cancelRequest(m_currentRequest);
+        m_currentRequest = MessageId();
+    }
 }
 
 void LanguageClientCompletionAssistProcessor::handleCompletionResponse(
     const CompletionRequest::Response &response)
 {
     qCDebug(LOGLSPCOMPLETION) << QTime::currentTime() << " : got completions";
-    m_running = false;
+    m_currentRequest = MessageId();
     QTC_ASSERT(m_client, return);
     if (auto error = response.error()) {
         m_client->log(error.value());

src/plugins/languageclient/languageclientfunctionhint.cpp

@@ -65,14 +65,15 @@ class FunctionHintProcessor : public IAssistProcessor
 public:
     explicit FunctionHintProcessor(Client *client) : m_client(client) {}
     IAssistProposal *perform(const AssistInterface *interface) override;
-    bool running() override { return m_running; }
+    bool running() override { return m_currentRequest.isValid(); }
     bool needsRestart() const override { return true; }
+    void cancel() override;
 
 private:
     void handleSignatureResponse(const SignatureHelpRequest::Response &response);
 
     QPointer<Client> m_client;
-    bool m_running = false;
+    MessageId m_currentRequest;
     int m_pos = -1;
 };
 
@@ -87,13 +88,21 @@ IAssistProposal *FunctionHintProcessor::perform(const AssistInterface *interface
     request.setParams(TextDocumentPositionParams(TextDocumentIdentifier(uri), Position(cursor)));
     request.setResponseCallback([this](auto response) { this->handleSignatureResponse(response); });
     m_client->sendContent(request);
-    m_running = true;
+    m_currentRequest = request.id();
     return nullptr;
 }
 
+void FunctionHintProcessor::cancel()
+{
+    if (running()) {
+        m_client->cancelRequest(m_currentRequest);
+        m_currentRequest = MessageId();
+    }
+}
+
 void FunctionHintProcessor::handleSignatureResponse(const SignatureHelpRequest::Response &response)
 {
-    m_running = false;
+    m_currentRequest = MessageId();
     if (auto error = response.error())
         m_client->log(error.value());
     FunctionHintProposalModelPtr model(

src/plugins/languageclient/languageclientquickfix.cpp

@@ -84,15 +84,16 @@ class LanguageClientQuickFixAssistProcessor : public IAssistProcessor
 {
 public:
     explicit LanguageClientQuickFixAssistProcessor(Client *client) : m_client(client) {}
-    bool running() override { return m_running; }
+    bool running() override { return m_currentRequest.isValid(); }
     IAssistProposal *perform(const AssistInterface *interface) override;
+    void cancel() override;
 
 private:
     void handleCodeActionResponse(const CodeActionRequest::Response &response);
 
     QSharedPointer<const AssistInterface> m_assistInterface;
     Client *m_client = nullptr; // not owned
-    bool m_running = false;
+    MessageId m_currentRequest;
 };
 
 IAssistProposal *LanguageClientQuickFixAssistProcessor::perform(const AssistInterface *interface)
@@ -123,14 +124,22 @@ IAssistProposal *LanguageClientQuickFixAssistProcessor::perform(const AssistInte
     });
 
     m_client->requestCodeActions(request);
-    m_running = true;
+    m_currentRequest = request.id();
     return nullptr;
 }
 
+void LanguageClientQuickFixAssistProcessor::cancel()
+{
+    if (running()) {
+        m_client->cancelRequest(m_currentRequest);
+        m_currentRequest = MessageId();
+    }
+}
+
 void LanguageClientQuickFixAssistProcessor::handleCodeActionResponse(
         const CodeActionRequest::Response &response)
 {
-    m_running = false;
+    m_currentRequest = MessageId();
     if (const Utils::optional<CodeActionRequest::Response::Error> &error = response.error())
         m_client->log(*error);
     QuickFixOperations ops;

src/plugins/texteditor/codeassist/codeassistant.cpp

@@ -288,6 +288,8 @@ void CodeAssistantPrivate::cancelCurrentRequest()
         m_requestRunner->setDiscardProposal(true);
         disconnect(m_runnerConnection);
     }
+    if (m_asyncProcessor)
+        m_asyncProcessor->cancel();
     invalidateCurrentRequestData();
 }
 

src/plugins/texteditor/codeassist/documentcontentcompletion.cpp

@@ -43,14 +43,15 @@
 
 using namespace TextEditor;
 
-class DocumentContentCompletionProcessor : public IAssistProcessor
+class DocumentContentCompletionProcessor final : public IAssistProcessor
 {
 public:
     DocumentContentCompletionProcessor(const QString &snippetGroupId);
-    ~DocumentContentCompletionProcessor() override;
+    ~DocumentContentCompletionProcessor() final;
 
     IAssistProposal *perform(const AssistInterface *interface) override;
     bool running() final { return m_watcher.isRunning(); }
+    void cancel() final;
 
 private:
     QString m_snippetGroup;
@@ -77,8 +78,7 @@ DocumentContentCompletionProcessor::DocumentContentCompletionProcessor(const QSt
 
 DocumentContentCompletionProcessor::~DocumentContentCompletionProcessor()
 {
-    if (m_watcher.isRunning())
+    cancel();
-        m_watcher.cancel();
 }
 
 static void createProposal(QFutureInterface<QStringList> &future, const QString &text,
@@ -149,3 +149,9 @@ IAssistProposal *DocumentContentCompletionProcessor::perform(const AssistInterfa
     });
     return nullptr;
 }
+
+void DocumentContentCompletionProcessor::cancel()
+{
+    if (running())
+        m_watcher.cancel();
+}

src/plugins/texteditor/codeassist/iassistprocessor.h

@@ -51,6 +51,7 @@ public:
 
     virtual bool running() { return false; }
     virtual bool needsRestart() const { return false; }
+    virtual void cancel() {}
 
 private:
     AsyncCompletionsAvailableHandler m_asyncCompletionsAvailableHandler;