Editor: delete assist interface in lsp/clangd support

The complete memory management in the code assistant needs an overhaul.
For now just delete or at least track the assist interface with scoped
pointers.

Fixes: QTCREATORBUG-28408
Change-Id: I0bd4cfaa36a660b6fd5bb467af3b13414ed76e63
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/plugins/clangcodemodel/clangdcompletion.cpp

@@ -417,6 +417,7 @@ IAssistProposal *CustomAssistProcessor::perform(const AssistInterface *interface
         break;
     }
     }
+    delete interface;
     GenericProposalModelPtr model(new GenericProposalModel);
     model->loadContent(completions);
     const auto proposal = new GenericProposal(m_position, model);

src/plugins/clangcodemodel/clangdfollowsymbol.cpp

@@ -12,6 +12,7 @@
 #include <languageclient/languageclientsymbolsupport.h>
 #include <languageserverprotocol/lsptypes.h>
 #include <languageserverprotocol/jsonrpcmessages.h>
+#include <texteditor/codeassist/assistinterface.h>
 #include <texteditor/codeassist/iassistprocessor.h>
 #include <texteditor/codeassist/iassistprovider.h>
 #include <texteditor/textdocument.h>
@@ -41,8 +42,9 @@ public:
     void resetData(bool resetFollowSymbolData);
 
 private:
-    IAssistProposal *perform(const AssistInterface *) override
+    IAssistProposal *perform(const AssistInterface *interface) override
     {
+        delete interface;
         return nullptr;
     }
 

src/plugins/languageclient/languageclientcompletionassist.cpp

@@ -293,7 +293,8 @@ LanguageClientCompletionAssistProcessor::~LanguageClientCompletionAssistProcesso
 
 QTextDocument *LanguageClientCompletionAssistProcessor::document() const
 {
-    return m_document;
+    QTC_ASSERT(m_assistInterface, return nullptr);
+    return m_assistInterface->textDocument();
 }
 
 QList<AssistProposalItemInterface *> LanguageClientCompletionAssistProcessor::generateCompletionItems(
@@ -315,6 +316,7 @@ static QString assistReasonString(AssistReason reason)
 
 IAssistProposal *LanguageClientCompletionAssistProcessor::perform(const AssistInterface *interface)
 {
+    m_assistInterface.reset(interface);
     QTC_ASSERT(m_client, return nullptr);
     m_pos = interface->position();
     m_basePos = m_pos;
@@ -366,7 +368,6 @@ IAssistProposal *LanguageClientCompletionAssistProcessor::perform(const AssistIn
     m_client->sendMessage(completionRequest);
     m_client->addAssistProcessor(this);
     m_currentRequest = completionRequest.id();
-    m_document = interface->textDocument();
     m_filePath = interface->filePath();
     qCDebug(LOGLSPCOMPLETION) << QTime::currentTime()
                               << " : request completions at " << m_pos
@@ -425,7 +426,7 @@ void LanguageClientCompletionAssistProcessor::handleCompletionResponse(
     model->loadContent(proposalItems);
     LanguageClientCompletionProposal *proposal = new LanguageClientCompletionProposal(m_basePos,
                                                                                       model);
-    proposal->m_document = m_document;
+    proposal->m_document = m_assistInterface->textDocument();
     proposal->m_pos = m_pos;
     proposal->setSupportsPrefix(false);
     setAsyncProposalAvailable(proposal);

src/plugins/languageclient/languageclientcompletionassist.h

@@ -11,6 +11,7 @@
 #include <texteditor/codeassist/iassistprocessor.h>
 
 #include <QPointer>
+#include <QScopedPointer>
 
 #include <functional>
 #include <optional>
@@ -74,7 +75,7 @@ protected:
 private:
     void handleCompletionResponse(const LanguageServerProtocol::CompletionRequest::Response &response);
 
-    QPointer<QTextDocument> m_document;
+    QScopedPointer<const TextEditor::AssistInterface> m_assistInterface;
     Utils::FilePath m_filePath;
     QPointer<Client> m_client;
     std::optional<LanguageServerProtocol::MessageId> m_currentRequest;

src/plugins/languageclient/languageclientfunctionhint.cpp

@@ -10,6 +10,8 @@
 #include <texteditor/codeassist/iassistprocessor.h>
 #include <texteditor/codeassist/ifunctionhintproposalmodel.h>
 
+#include <QScopedPointer>
+
 using namespace TextEditor;
 using namespace LanguageServerProtocol;
 
@@ -66,6 +68,7 @@ FunctionHintProcessor::FunctionHintProcessor(Client *client)
 
 IAssistProposal *FunctionHintProcessor::perform(const AssistInterface *interface)
 {
+    const QScopedPointer<const AssistInterface> deleter(interface);
     QTC_ASSERT(m_client, return nullptr);
     m_pos = interface->position();
     QTextCursor cursor(interface->textDocument());

src/plugins/texteditor/codeassist/iassistprocessor.h

@@ -19,7 +19,7 @@ public:
     virtual ~IAssistProcessor();
 
     virtual IAssistProposal *immediateProposal(const AssistInterface *) { return nullptr; }
-    virtual IAssistProposal *perform(const AssistInterface *interface) = 0;
+    virtual IAssistProposal *perform(const AssistInterface *interface) = 0; // takes ownership
 
     void setAsyncProposalAvailable(IAssistProposal *proposal);