From 108f83f336e88ceb7e58ed4097bbb9b36eb2a465 Mon Sep 17 00:00:00 2001
From: David Schulz <david.schulz@qt.io>
Date: Mon, 7 Jan 2019 13:24:01 +0100
Subject: [PATCH] LSP: replace LanguageClientNull with nullptr_t

Prevent implicit converting of the null type to JsonObjects or
JsonValues.

Change-Id: Ib1b74d8a7962cbb308ad0d1bca117cfd2130fb1b
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
---
 src/libs/languageserverprotocol/client.h      |  4 +-
 src/libs/languageserverprotocol/completion.h  |  4 +-
 .../initializemessages.h                      |  2 +-
 .../languageserverprotocol/jsonrpcmessages.h  | 33 +++++++++++++-
 .../languageserverprotocol/languagefeatures.h | 44 +++++++++----------
 src/libs/languageserverprotocol/messages.h    |  2 +-
 .../languageserverprotocol/shutdownmessages.h |  4 +-
 .../textsynchronization.h                     |  2 +-
 src/libs/languageserverprotocol/workspace.h   | 10 ++---
 src/plugins/languageclient/baseclient.cpp     |  6 +--
 10 files changed, 70 insertions(+), 41 deletions(-)

diff --git a/src/libs/languageserverprotocol/client.h b/src/libs/languageserverprotocol/client.h
index f8f601f9d47..bf2fe5421a1 100644
--- a/src/libs/languageserverprotocol/client.h
+++ b/src/libs/languageserverprotocol/client.h
@@ -70,7 +70,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT RegisterCapabilityRequest : public Request<
-        LanguageClientNull, LanguageClientNull, RegistrationParams>
+        std::nullptr_t, std::nullptr_t, RegistrationParams>
 {
 public:
     RegisterCapabilityRequest(const RegistrationParams &params = RegistrationParams());
@@ -108,7 +108,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT UnregisterCapabilityRequest : public Request<
-        LanguageClientNull, LanguageClientNull, UnregistrationParams>
+        std::nullptr_t, std::nullptr_t, UnregistrationParams>
 {
 public:
     UnregisterCapabilityRequest(const UnregistrationParams &params = UnregistrationParams());
diff --git a/src/libs/languageserverprotocol/completion.h b/src/libs/languageserverprotocol/completion.h
index b05825cd00b..3db5be4d704 100644
--- a/src/libs/languageserverprotocol/completion.h
+++ b/src/libs/languageserverprotocol/completion.h
@@ -253,7 +253,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT CompletionRequest : public Request<
-        CompletionResult, LanguageClientNull, CompletionParams>
+        CompletionResult, std::nullptr_t, CompletionParams>
 {
 public:
     CompletionRequest(const CompletionParams &params = CompletionParams());
@@ -262,7 +262,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT CompletionItemResolveRequest : public Request<
-        CompletionItem, LanguageClientNull, CompletionItem>
+        CompletionItem, std::nullptr_t, CompletionItem>
 {
 public:
     CompletionItemResolveRequest(const CompletionItem &params = CompletionItem());
diff --git a/src/libs/languageserverprotocol/initializemessages.h b/src/libs/languageserverprotocol/initializemessages.h
index 2a923179b87..9224cea7737 100644
--- a/src/libs/languageserverprotocol/initializemessages.h
+++ b/src/libs/languageserverprotocol/initializemessages.h
@@ -124,7 +124,7 @@ public:
     bool isValid(QStringList *error) const override;
 };
 
-class LANGUAGESERVERPROTOCOL_EXPORT InitializeNotification : public Notification<LanguageClientNull>
+class LANGUAGESERVERPROTOCOL_EXPORT InitializeNotification : public Notification<std::nullptr_t>
 {
 public:
     InitializeNotification();
diff --git a/src/libs/languageserverprotocol/jsonrpcmessages.h b/src/libs/languageserverprotocol/jsonrpcmessages.h
index d4405b87678..3ce55474432 100644
--- a/src/libs/languageserverprotocol/jsonrpcmessages.h
+++ b/src/libs/languageserverprotocol/jsonrpcmessages.h
@@ -42,8 +42,6 @@
 
 namespace LanguageServerProtocol {
 
-using LanguageClientNull = JsonObject;
-
 class LANGUAGESERVERPROTOCOL_EXPORT JsonRpcMessage : public IContent
 {
 public:
@@ -132,6 +130,37 @@ public:
     }
 };
 
+template <>
+class Notification<std::nullptr_t> : public JsonRpcMessage
+{
+public:
+    Notification() : Notification(QString()) {}
+    Notification(const QString &methodName, const std::nullptr_t &/*params*/ = nullptr)
+    { setMethod(methodName); }
+    using JsonRpcMessage::JsonRpcMessage;
+
+    QString method() const
+    { return fromJsonValue<QString>(m_jsonObject.value(methodKey)); }
+    void setMethod(const QString &method)
+    { m_jsonObject.insert(methodKey, method); }
+
+    Utils::optional<std::nullptr_t> params() const
+    { return nullptr; }
+    void setParams(const std::nullptr_t &/*params*/)
+    { m_jsonObject.insert(parametersKey, QJsonValue::Null); }
+    void clearParams() { m_jsonObject.remove(parametersKey); }
+
+    bool isValid(QString *errorMessage) const override
+    {
+        return JsonRpcMessage::isValid(errorMessage)
+               && m_jsonObject.value(methodKey).isString()
+               && parametersAreValid(errorMessage);
+    }
+
+    virtual bool parametersAreValid(QString * /*errorMessage*/) const
+    { return true; }
+};
+
 template <typename Error>
 class ResponseError : public JsonObject
 {
diff --git a/src/libs/languageserverprotocol/languagefeatures.h b/src/libs/languageserverprotocol/languagefeatures.h
index d585ce8c9fa..5b9bd3cf440 100644
--- a/src/libs/languageserverprotocol/languagefeatures.h
+++ b/src/libs/languageserverprotocol/languagefeatures.h
@@ -85,8 +85,8 @@ public:
     { return check<MarkedString>(error, contentKey) && checkOptional<Range>(error, rangeKey); }
 };
 
-class LANGUAGESERVERPROTOCOL_EXPORT HoverRequest : public Request<
-        Hover, LanguageClientNull, TextDocumentPositionParams>
+class LANGUAGESERVERPROTOCOL_EXPORT HoverRequest
+    : public Request<Hover, std::nullptr_t, TextDocumentPositionParams>
 {
 public:
     HoverRequest(const TextDocumentPositionParams &params = TextDocumentPositionParams());
@@ -180,8 +180,8 @@ public:
     bool isValid(QStringList *error) const override;
 };
 
-class LANGUAGESERVERPROTOCOL_EXPORT SignatureHelpRequest : public Request<
-        LanguageClientValue<SignatureHelp>, LanguageClientNull, TextDocumentPositionParams>
+class LANGUAGESERVERPROTOCOL_EXPORT SignatureHelpRequest
+    : public Request<LanguageClientValue<SignatureHelp>, std::nullptr_t, TextDocumentPositionParams>
 {
 public:
     SignatureHelpRequest(const TextDocumentPositionParams &params = TextDocumentPositionParams());
@@ -198,8 +198,8 @@ public:
     using variant::variant;
 };
 
-class LANGUAGESERVERPROTOCOL_EXPORT GotoDefinitionRequest : public Request<
-        GotoResult, LanguageClientNull, TextDocumentPositionParams>
+class LANGUAGESERVERPROTOCOL_EXPORT GotoDefinitionRequest
+    : public Request<GotoResult, std::nullptr_t, TextDocumentPositionParams>
 {
 public:
     GotoDefinitionRequest(const TextDocumentPositionParams &params = TextDocumentPositionParams());
@@ -208,7 +208,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT GotoTypeDefinitionRequest : public Request<
-        GotoResult, LanguageClientNull, TextDocumentPositionParams>
+        GotoResult, std::nullptr_t, TextDocumentPositionParams>
 {
 public:
     GotoTypeDefinitionRequest(
@@ -218,7 +218,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT GotoImplementationRequest : public Request<
-        GotoResult, LanguageClientNull, TextDocumentPositionParams>
+        GotoResult, std::nullptr_t, TextDocumentPositionParams>
 {
 public:
     GotoImplementationRequest(
@@ -254,7 +254,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT FindReferencesRequest : public Request<
-        LanguageClientArray<Location>, LanguageClientNull, ReferenceParams>
+        LanguageClientArray<Location>, std::nullptr_t, ReferenceParams>
 {
 public:
     FindReferencesRequest(const ReferenceParams &params = ReferenceParams());
@@ -295,7 +295,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT DocumentHighlightsRequest : public Request<
-        DocumentHighlightsResult, LanguageClientNull, TextDocumentPositionParams>
+        DocumentHighlightsResult, std::nullptr_t, TextDocumentPositionParams>
 {
 public:
     DocumentHighlightsRequest(
@@ -333,7 +333,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT DocumentSymbolsRequest
-        : public Request<DocumentSymbolsResult, LanguageClientNull, DocumentSymbolParams>
+        : public Request<DocumentSymbolsResult, std::nullptr_t, DocumentSymbolParams>
 {
 public:
     DocumentSymbolsRequest(const DocumentSymbolParams &params = DocumentSymbolParams());
@@ -373,7 +373,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT CodeActionRequest : public Request<
-        LanguageClientArray<Command>, LanguageClientNull, CodeActionParams>
+        LanguageClientArray<Command>, std::nullptr_t, CodeActionParams>
 {
 public:
     CodeActionRequest(const CodeActionParams &params = CodeActionParams());
@@ -404,7 +404,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT CodeLensRequest : public Request<
-        LanguageClientArray<CodeLens>, LanguageClientNull, CodeLensParams>
+        LanguageClientArray<CodeLens>, std::nullptr_t, CodeLensParams>
 {
 public:
     CodeLensRequest(const CodeLensParams &params = CodeLensParams());
@@ -413,7 +413,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT CodeLensResolveRequest : public Request<
-        CodeLens, LanguageClientNull, CodeLens>
+        CodeLens, std::nullptr_t, CodeLens>
 {
 public:
     CodeLensResolveRequest(const CodeLens &params = CodeLens());
@@ -444,7 +444,7 @@ public:
 using DocumentLinkParams = TextDocumentParams;
 
 class LANGUAGESERVERPROTOCOL_EXPORT DocumentLinkRequest : public Request<
-        LanguageClientValue<DocumentLink>, LanguageClientNull, DocumentLinkParams>
+        LanguageClientValue<DocumentLink>, std::nullptr_t, DocumentLinkParams>
 {
 public:
     DocumentLinkRequest(const DocumentLinkParams &params = DocumentLinkParams());
@@ -453,7 +453,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT DocumentLinkResolveRequest : public Request<
-        DocumentLink, LanguageClientNull, DocumentLink>
+        DocumentLink, std::nullptr_t, DocumentLink>
 {
 public:
     DocumentLinkResolveRequest(const DocumentLink &params = DocumentLink());
@@ -499,7 +499,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT DocumentColorRequest : public Request<
-        QList<ColorInformation>, LanguageClientNull, DocumentColorParams>
+        QList<ColorInformation>, std::nullptr_t, DocumentColorParams>
 {
 public:
     DocumentColorRequest(const DocumentColorParams &params = DocumentColorParams());
@@ -553,7 +553,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT ColorPresentationRequest : public Request<
-        QList<ColorPresentation>, LanguageClientNull, ColorPresentationParams>
+        QList<ColorPresentation>, std::nullptr_t, ColorPresentationParams>
 {
 public:
     ColorPresentationRequest(const ColorPresentationParams &params = ColorPresentationParams());
@@ -610,7 +610,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT DocumentFormattingRequest : public Request<
-        LanguageClientArray<TextEdit>, LanguageClientNull, DocumentFormattingParams>
+        LanguageClientArray<TextEdit>, std::nullptr_t, DocumentFormattingParams>
 {
 public:
     DocumentFormattingRequest(const DocumentFormattingParams &params = DocumentFormattingParams());
@@ -638,7 +638,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT DocumentRangeFormattingRequest : public Request<
-        QList<TextEdit>, LanguageClientNull, DocumentFormattingParams>
+        QList<TextEdit>, std::nullptr_t, DocumentFormattingParams>
 {
 public:
     DocumentRangeFormattingRequest(const DocumentFormattingParams &params = DocumentFormattingParams());
@@ -669,7 +669,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT DocumentOnTypeFormattingRequest : public Request<
-        QList<TextEdit>, LanguageClientNull, DocumentFormattingParams>
+        QList<TextEdit>, std::nullptr_t, DocumentFormattingParams>
 {
 public:
     DocumentOnTypeFormattingRequest(
@@ -698,7 +698,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT RenameRequest : public Request<
-        WorkspaceEdit, LanguageClientNull, RenameParams>
+        WorkspaceEdit, std::nullptr_t, RenameParams>
 {
 public:
     RenameRequest(const RenameParams &params = RenameParams());
diff --git a/src/libs/languageserverprotocol/messages.h b/src/libs/languageserverprotocol/messages.h
index 904f78d3eeb..9ad06efb9e2 100644
--- a/src/libs/languageserverprotocol/messages.h
+++ b/src/libs/languageserverprotocol/messages.h
@@ -87,7 +87,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT ShowMessageRequest : public Request<
-        LanguageClientValue<MessageActionItem>, LanguageClientNull, ShowMessageRequestParams>
+        LanguageClientValue<MessageActionItem>, std::nullptr_t, ShowMessageRequestParams>
 {
 public:
     ShowMessageRequest(const ShowMessageRequestParams &params = ShowMessageRequestParams());
diff --git a/src/libs/languageserverprotocol/shutdownmessages.h b/src/libs/languageserverprotocol/shutdownmessages.h
index 57bc2d3bea2..be051d57452 100644
--- a/src/libs/languageserverprotocol/shutdownmessages.h
+++ b/src/libs/languageserverprotocol/shutdownmessages.h
@@ -30,7 +30,7 @@
 namespace LanguageServerProtocol {
 
 class LANGUAGESERVERPROTOCOL_EXPORT ShutdownRequest : public Request<
-        LanguageClientNull, LanguageClientNull, LanguageClientNull>
+        std::nullptr_t, std::nullptr_t, std::nullptr_t>
 {
 public:
     ShutdownRequest();
@@ -38,7 +38,7 @@ public:
     constexpr static const char methodName[] = "shutdown";
 };
 
-class LANGUAGESERVERPROTOCOL_EXPORT ExitNotification : public Notification<LanguageClientNull>
+class LANGUAGESERVERPROTOCOL_EXPORT ExitNotification : public Notification<std::nullptr_t>
 {
 public:
     ExitNotification();
diff --git a/src/libs/languageserverprotocol/textsynchronization.h b/src/libs/languageserverprotocol/textsynchronization.h
index 8569bc6ef9e..2b659366cdf 100644
--- a/src/libs/languageserverprotocol/textsynchronization.h
+++ b/src/libs/languageserverprotocol/textsynchronization.h
@@ -165,7 +165,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT WillSaveWaitUntilTextDocumentRequest : public Request<
-        LanguageClientArray<TextEdit>, LanguageClientNull, WillSaveTextDocumentParams>
+        LanguageClientArray<TextEdit>, std::nullptr_t, WillSaveTextDocumentParams>
 {
 public:
     WillSaveWaitUntilTextDocumentRequest(
diff --git a/src/libs/languageserverprotocol/workspace.h b/src/libs/languageserverprotocol/workspace.h
index 8674165c072..771e6d9d9b9 100644
--- a/src/libs/languageserverprotocol/workspace.h
+++ b/src/libs/languageserverprotocol/workspace.h
@@ -30,7 +30,7 @@
 namespace LanguageServerProtocol {
 
 class LANGUAGESERVERPROTOCOL_EXPORT WorkSpaceFolderRequest : public Request<
-        Utils::variant<QList<WorkSpaceFolder>, Utils::nullopt_t>, LanguageClientNull, LanguageClientNull>
+        Utils::variant<QList<WorkSpaceFolder>, Utils::nullopt_t>, std::nullptr_t, std::nullptr_t>
 {
 public:
     WorkSpaceFolderRequest();
@@ -126,7 +126,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT ConfigurationRequest : public Request<
-        LanguageClientArray<QJsonValue>, LanguageClientNull, ConfigurationParams>
+        LanguageClientArray<QJsonValue>, std::nullptr_t, ConfigurationParams>
 {
 public:
     ConfigurationRequest(const ConfigurationParams &params = ConfigurationParams());
@@ -188,7 +188,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT WorkspaceSymbolRequest : public Request<
-        LanguageClientArray<SymbolInformation>, LanguageClientNull, WorkspaceSymbolParams>
+        LanguageClientArray<SymbolInformation>, std::nullptr_t, WorkspaceSymbolParams>
 {
 public:
     WorkspaceSymbolRequest(const WorkspaceSymbolParams &params = WorkspaceSymbolParams());
@@ -218,7 +218,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT ExecuteCommandRequest : public Request<
-        QJsonValue, LanguageClientNull, ExecuteCommandParams>
+        QJsonValue, std::nullptr_t, ExecuteCommandParams>
 {
 public:
     ExecuteCommandRequest(const ExecuteCommandParams &params = ExecuteCommandParams());
@@ -254,7 +254,7 @@ public:
 };
 
 class LANGUAGESERVERPROTOCOL_EXPORT ApplyWorkspaceEditRequest : public Request<
-        ApplyWorkspaceEditResponse, LanguageClientNull, ApplyWorkspaceEditParams>
+        ApplyWorkspaceEditResponse, std::nullptr_t, ApplyWorkspaceEditParams>
 {
 public:
     ApplyWorkspaceEditRequest(const ApplyWorkspaceEditParams &params = ApplyWorkspaceEditParams());
diff --git a/src/plugins/languageclient/baseclient.cpp b/src/plugins/languageclient/baseclient.cpp
index 3bae36c25a2..e97f4688620 100644
--- a/src/plugins/languageclient/baseclient.cpp
+++ b/src/plugins/languageclient/baseclient.cpp
@@ -617,7 +617,7 @@ void BaseClient::handleMethod(const QString &method, MessageId id, const IConten
         } else {
             ShowMessageRequest::Response response;
             response.setId(request->id());
-            ResponseError<LanguageClientNull> error;
+            ResponseError<std::nullptr_t> error;
             const QString errorMessage =
                     QString("Could not parse ShowMessageRequest parameter of '%1': \"%2\"")
                     .arg(request->id().toString(),
@@ -696,9 +696,9 @@ void BaseClient::intializeCallback(const InitializeRequest::Response &initRespon
 void BaseClient::shutDownCallback(const ShutdownRequest::Response &shutdownResponse)
 {
     QTC_ASSERT(m_state == ShutdownRequested, return);
-    optional<ResponseError<JsonObject>> errorValue = shutdownResponse.error();
+    optional<ShutdownRequest::Response::Error> errorValue = shutdownResponse.error();
     if (errorValue.has_value()) {
-        ResponseError<JsonObject> error = errorValue.value();
+        ShutdownRequest::Response::Error error = errorValue.value();
         qDebug() << error;
         return;
     }