ClangCodeModel: Support parse contexts with clangd

Fixes: QTCREATORBUG-27009
Change-Id: I177db0658d545211b940623cae071db91e82ddb4
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/clangcodemodel/clangdclient.cpp

@@ -1142,6 +1142,7 @@ public:
     std::unordered_map<TextDocument *, CppEditor::SemanticHighlighter *> highlighters;
 
     QHash<TextDocument *, QPair<QList<ExpandedSemanticToken>, int>> previousTokens;
+    QHash<Utils::FilePath, CppEditor::BaseEditorDocumentParser::Configuration> parserConfigs;
 
     // The ranges of symbols referring to virtual functions, with document version,
     // as extracted by the highlighting procedure.
@@ -1468,6 +1469,7 @@ void ClangdClient::handleDocumentClosed(TextDocument *doc)
     d->astCache.remove(doc);
     d->previousTokens.remove(doc);
     d->virtualRanges.remove(doc);
+    d->parserConfigs.remove(doc->filePath());
 }
 
 QTextCursor ClangdClient::adjustedCursorForHighlighting(const QTextCursor &cursor,
@@ -1625,6 +1627,39 @@ void ClangdClient::handleUiHeaderChange(const QString &fileName)
     }
 }
 
+void ClangdClient::updateParserConfig(const Utils::FilePath &filePath,
+        const CppEditor::BaseEditorDocumentParser::Configuration &config)
+{
+    if (config.preferredProjectPartId.isEmpty())
+        return;
+
+    CppEditor::BaseEditorDocumentParser::Configuration &cachedConfig = d->parserConfigs[filePath];
+    if (cachedConfig == config)
+        return;
+    cachedConfig = config;
+
+    // TODO: Also handle editorDefines (and usePrecompiledHeaders?)
+    const auto projectPart = CppEditor::CppModelManager::instance()
+            ->projectPartForId(config.preferredProjectPartId);
+    if (!projectPart)
+        return;
+    const CppEditor::ClangDiagnosticConfig projectWarnings = warningsConfigForProject(project());
+    const QStringList projectOptions = optionsForProject(project());
+    QJsonObject cdbChanges;
+    QStringList args = createClangOptions(*projectPart, filePath.toString(), projectWarnings,
+                                          projectOptions);
+    args.prepend("clang");
+    args.append(filePath.toString());
+    QJsonObject value;
+    value.insert("workingDirectory", filePath.parentDir().toString());
+    value.insert("compilationCommand", QJsonArray::fromStringList(args));
+    cdbChanges.insert(filePath.toUserOutput(), value);
+    const QJsonObject settings({qMakePair(QString("compilationDatabaseChanges"), cdbChanges)});
+    DidChangeConfigurationParams configChangeParams;
+    configChangeParams.setSettings(settings);
+    sendContent(DidChangeConfigurationNotification(configChangeParams));
+}
+
 void ClangdClient::Private::handleFindUsagesResult(quint64 key, const QList<Location> &locations)
 {
     const auto refData = runningFindUsages.find(key);

src/plugins/clangcodemodel/clangdclient.h

@@ -25,6 +25,7 @@
 
 #pragma once
 
+#include <cppeditor/baseeditordocumentparser.h>
 #include <cppeditor/cppcodemodelsettings.h>
 #include <cppeditor/refactoringengineinterface.h>
 #include <languageclient/client.h>
@@ -88,6 +89,9 @@ public:
 
     static void handleUiHeaderChange(const QString &fileName);
 
+    void updateParserConfig(const Utils::FilePath &filePath,
+                            const CppEditor::BaseEditorDocumentParser::Configuration &config);
+
 signals:
     void indexingFinished();
     void foundReferences(const QList<Core::SearchResultItem> &items);

src/plugins/clangcodemodel/clangeditordocumentprocessor.cpp

@@ -328,6 +328,12 @@ void ClangEditorDocumentProcessor::setParserConfig(
 {
     m_parser->setConfiguration(config);
     m_builtinProcessor.parser()->setConfiguration(config);
+    emit parserConfigChanged(Utils::FilePath::fromString(filePath()), config);
+}
+
+CppEditor::BaseEditorDocumentParser::Configuration ClangEditorDocumentProcessor::parserConfig() const
+{
+    return m_parser->configuration();
 }
 
 static bool isCursorOnIdentifier(const QTextCursor &textCursor)

src/plugins/clangcodemodel/clangeditordocumentprocessor.h

@@ -91,6 +91,7 @@ public:
     void editorDocumentTimerRestarted() override;
 
     void setParserConfig(const CppEditor::BaseEditorDocumentParser::Configuration &config) override;
+    CppEditor::BaseEditorDocumentParser::Configuration parserConfig() const;
 
     QFuture<CppEditor::CursorInfo> cursorInfo(const CppEditor::CursorInfoParams &params) override;
     QFuture<CppEditor::CursorInfo> requestLocalReferences(const QTextCursor &cursor) override;
@@ -115,6 +116,8 @@ public:
 
 signals:
     void tokenInfosUpdated();
+    void parserConfigChanged(const Utils::FilePath &filePath,
+                             const CppEditor::BaseEditorDocumentParser::Configuration &config);
 
 private:
     void onParserFinished();

src/plugins/clangcodemodel/clangmodelmanagersupport.cpp

@@ -217,7 +217,15 @@ bool ClangModelManagerSupport::supportsLocalUses(const TextEditor::TextDocument
 CppEditor::BaseEditorDocumentProcessor *ClangModelManagerSupport::createEditorDocumentProcessor(
         TextEditor::TextDocument *baseTextDocument)
 {
-    return new ClangEditorDocumentProcessor(m_communicator, baseTextDocument);
+    const auto processor = new ClangEditorDocumentProcessor(m_communicator, baseTextDocument);
+    const auto handleConfigChange = [this](const Utils::FilePath &fp,
+            const BaseEditorDocumentParser::Configuration &config) {
+        if (const auto client = clientForFile(fp))
+            client->updateParserConfig(fp, config);
+    };
+    connect(processor, &ClangEditorDocumentProcessor::parserConfigChanged,
+            this, handleConfigChange);
+    return processor;
 }
 
 void ClangModelManagerSupport::onCurrentEditorChanged(Core::IEditor *editor)
@@ -233,6 +241,8 @@ void ClangModelManagerSupport::onCurrentEditorChanged(Core::IEditor *editor)
     if (auto processor = ClangEditorDocumentProcessor::get(filePath.toString())) {
         processor->semanticRehighlight();
         processor->generateTaskHubIssues();
+        if (const auto client = clientForFile(filePath))
+            client->updateParserConfig(filePath, processor->parserConfig());
     }
 }
 
@@ -342,16 +352,38 @@ void ClangModelManagerSupport::updateLanguageClient(
             if (!newProjectInfo || *newProjectInfo != *projectInfo)
                 return;
 
+            const auto updateParserConfig = [client] {
+                if (const auto editor = TextEditor::BaseTextEditor::currentTextEditor()) {
+                    if (!client->documentOpen(editor->textDocument()))
+                        return;
+                    const Utils::FilePath filePath = editor->textDocument()->filePath();
+                    if (const auto processor = ClangEditorDocumentProcessor::get(
+                                filePath.toString())) {
+                        const CppEditor::BaseEditorDocumentParser::Configuration config
+                                = processor->parserConfig();
+                        client->updateParserConfig(filePath, config);
+                    }
+                }
+            };
+
             // Acquaint the client with all open C++ documents for this project.
             bool hasDocuments = false;
             for (TextEditor::BaseTextEditor * const editor : allCppEditors()) {
-                if (!project->isKnownFile(editor->textDocument()->filePath()))
+                const Utils::FilePath filePath = editor->textDocument()->filePath();
+                if (!project->isKnownFile(filePath))
                     continue;
                 LanguageClientManager::openDocumentWithClient(editor->textDocument(), client);
-                ClangEditorDocumentProcessor::clearTextMarks(editor->textDocument()->filePath());
+                ClangEditorDocumentProcessor::clearTextMarks(filePath);
                 hasDocuments = true;
             }
 
+            if (client->state() == Client::Initialized)
+                updateParserConfig();
+            else
+                connect(client, &Client::initialized, client, updateParserConfig);
+            connect(CppModelManager::instance(), &CppModelManager::projectPartsUpdated,
+                    client, updateParserConfig);
+
             if (hasDocuments)
                 return;
 

src/plugins/cppeditor/baseeditordocumentparser.h

@@ -50,6 +50,13 @@ public:
         bool usePrecompiledHeaders = false;
         QByteArray editorDefines;
         QString preferredProjectPartId;
+
+        bool operator==(const Configuration &other)
+        {
+            return usePrecompiledHeaders == other.usePrecompiledHeaders
+                    && editorDefines == other.editorDefines
+                    && preferredProjectPartId == other.preferredProjectPartId;
+        }
     };
 
     struct UpdateParams {