Modernize Type Hierarchy

Don't freeze UI on request for show Type Hierarchy.
Move the lookup code into a separate thread.
Don't clear tree hierarchy when waiting for new one.
Show progress indicator on top of old hierarchy instead.
Add a task to ProgressManager when working on a new hierarchy.
Handle canceling the process of showing Type Hierarchy.
Implement simple progress reporting for this process.
Optimize a bit DerivedHierarchyVisitor.

Change-Id: I3894ac6ed3f4834831831f083f718f8385ca346f
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/cppeditor/cpptypehierarchy.cpp

@@ -32,11 +32,13 @@
 
 #include <coreplugin/find/itemviewfind.h>
 #include <coreplugin/editormanager/editormanager.h>
+#include <coreplugin/progressmanager/progressmanager.h>
 #include <cpptools/cppelementevaluator.h>
 #include <utils/algorithm.h>
 #include <utils/delegates.h>
-#include <utils/navigationtreeview.h>
 #include <utils/dropsupport.h>
+#include <utils/navigationtreeview.h>
+#include <utils/progressindicator.h>
 
 #include <QApplication>
 #include <QLabel>
@@ -107,10 +109,10 @@ CppTypeHierarchyWidget::CppTypeHierarchyWidget()
     m_treeView->setDefaultDropAction(Qt::MoveAction);
     connect(m_treeView, &QTreeView::activated, this, &CppTypeHierarchyWidget::onItemActivated);
 
-    m_noTypeHierarchyAvailableLabel = new QLabel(tr("No type hierarchy available"), this);
+    m_infoLabel = new QLabel(this);
-    m_noTypeHierarchyAvailableLabel->setAlignment(Qt::AlignCenter);
+    m_infoLabel->setAlignment(Qt::AlignCenter);
-    m_noTypeHierarchyAvailableLabel->setAutoFillBackground(true);
+    m_infoLabel->setAutoFillBackground(true);
-    m_noTypeHierarchyAvailableLabel->setBackgroundRole(QPalette::Base);
+    m_infoLabel->setBackgroundRole(QPalette::Base);
 
     m_hierarchyWidget = new QWidget(this);
     auto layout = new QVBoxLayout;
@@ -122,37 +124,72 @@ CppTypeHierarchyWidget::CppTypeHierarchyWidget()
 
     m_stackLayout = new QStackedLayout;
     m_stackLayout->addWidget(m_hierarchyWidget);
-    m_stackLayout->addWidget(m_noTypeHierarchyAvailableLabel);
+    m_stackLayout->addWidget(m_infoLabel);
-    m_stackLayout->setCurrentWidget(m_noTypeHierarchyAvailableLabel);
+    showNoTypeHierarchyLabel();
     setLayout(m_stackLayout);
 
-    connect(CppEditorPlugin::instance(), &CppEditorPlugin::typeHierarchyRequested, this, &CppTypeHierarchyWidget::perform);
+    connect(CppEditorPlugin::instance(), &CppEditorPlugin::typeHierarchyRequested,
+            this, &CppTypeHierarchyWidget::perform);
+    connect(&m_futureWatcher, &QFutureWatcher<QSharedPointer<CppElement>>::finished,
+            this, &CppTypeHierarchyWidget::displayHierarchy);
 }
 
-CppTypeHierarchyWidget::~CppTypeHierarchyWidget() = default;
+CppTypeHierarchyWidget::~CppTypeHierarchyWidget()
+{
+    if (m_future.isRunning()) {
+        m_future.cancel();
+        m_future.waitForFinished();
+    }
+}
 
 void CppTypeHierarchyWidget::perform()
 {
-    showNoTypeHierarchyLabel();
+    if (m_future.isRunning())
+        m_future.cancel();
 
     auto editor = qobject_cast<CppEditor *>(Core::EditorManager::currentEditor());
-    if (!editor)
+    if (!editor) {
+        showNoTypeHierarchyLabel();
         return;
+    }
 
     auto widget = qobject_cast<CppEditorWidget *>(editor->widget());
-    if (!widget)
+    if (!widget) {
+        showNoTypeHierarchyLabel();
         return;
+    }
 
-    clearTypeHierarchy();
+    showProgress();
 
     CppElementEvaluator evaluator(widget);
     evaluator.setLookupBaseClasses(true);
     evaluator.setLookupDerivedClasses(true);
-    evaluator.execute();
+    m_future = evaluator.asyncExecute();
-    if (evaluator.identifiedCppElement()) {
+    m_futureWatcher.setFuture(m_future);
-        const QSharedPointer<CppElement> &cppElement = evaluator.cppElement();
+
-        CppElement *element = cppElement.data();
+    Core::ProgressManager::addTask(m_future, tr("Evaluating Type Hierarchy"), "TypeHierarchy");
-        if (CppClass *cppClass = element->toCppClass()) {
+}
+
+void CppTypeHierarchyWidget::displayHierarchy()
+{
+    hideProgress();
+    clearTypeHierarchy();
+
+    if (!m_future.resultCount() || m_future.isCanceled()) {
+        showNoTypeHierarchyLabel();
+        return;
+    }
+    const QSharedPointer<CppElement> &cppElement = m_future.result();
+    if (cppElement.isNull()) {
+        showNoTypeHierarchyLabel();
+        return;
+    }
+    CppClass *cppClass = cppElement->toCppClass();
+    if (!cppClass) {
+        showNoTypeHierarchyLabel();
+        return;
+    }
+
     m_inspectedClass->setText(cppClass->name);
     m_inspectedClass->setLink(cppClass->link);
     QStandardItem *bases = new QStandardItem(tr("Bases"));
@@ -165,8 +202,6 @@ void CppTypeHierarchyWidget::perform()
 
     showTypeHierarchy();
 }
-    }
-}
 
 void CppTypeHierarchyWidget::buildHierarchy(const CppClass &cppClass, QStandardItem *parent,
                                             bool isRoot, const HierarchyMember member)
@@ -182,7 +217,8 @@ void CppTypeHierarchyWidget::buildHierarchy(const CppClass &cppClass, QStandardI
 
 void CppTypeHierarchyWidget::showNoTypeHierarchyLabel()
 {
-    m_stackLayout->setCurrentWidget(m_noTypeHierarchyAvailableLabel);
+    m_infoLabel->setText(tr("No type hierarchy available"));
+    m_stackLayout->setCurrentWidget(m_infoLabel);
 }
 
 void CppTypeHierarchyWidget::showTypeHierarchy()
@@ -190,6 +226,22 @@ void CppTypeHierarchyWidget::showTypeHierarchy()
     m_stackLayout->setCurrentWidget(m_hierarchyWidget);
 }
 
+void CppTypeHierarchyWidget::showProgress()
+{
+    m_infoLabel->setText(tr("Evaluating type hierarchy..."));
+    if (!m_progressIndicator) {
+        m_progressIndicator = new Utils::ProgressIndicator(Utils::ProgressIndicatorSize::Large);
+        m_progressIndicator->attachToWidget(this);
+    }
+    m_progressIndicator->show();
+    m_progressIndicator->raise();
+}
+void CppTypeHierarchyWidget::hideProgress()
+{
+    if (m_progressIndicator)
+        m_progressIndicator->hide();
+}
+
 void CppTypeHierarchyWidget::clearTypeHierarchy()
 {
     m_inspectedClass->clear();

src/plugins/cppeditor/cpptypehierarchy.h

@@ -27,11 +27,14 @@
 
 #include <coreplugin/inavigationwidgetfactory.h>
 
+#include <QFuture>
+#include <QFutureWatcher>
 #include <QList>
-#include <QString>
+#include <QSharedPointer>
-#include <QWidget>
 #include <QStackedWidget>
 #include <QStandardItemModel>
+#include <QString>
+#include <QWidget>
 
 QT_BEGIN_NAMESPACE
 class QLabel;
@@ -43,11 +46,12 @@ QT_END_NAMESPACE
 namespace TextEditor { class TextEditorLinkLabel; }
 
 namespace Utils {
-class NavigationTreeView;
 class AnnotatedItemDelegate;
+class NavigationTreeView;
+class ProgressIndicator;
 }
 
-namespace CppTools { class CppClass; }
+namespace CppTools { class CppClass; class CppElement; }
 
 namespace CppEditor {
 namespace Internal {
@@ -75,12 +79,17 @@ public:
 
     void perform();
 
+private slots:
+    void displayHierarchy();
+
 private:
     typedef QList<CppTools::CppClass> CppTools::CppClass::*HierarchyMember;
     void buildHierarchy(const CppTools::CppClass &cppClass, QStandardItem *parent,
                         bool isRoot, HierarchyMember member);
     void showNoTypeHierarchyLabel();
     void showTypeHierarchy();
+    void showProgress();
+    void hideProgress();
     void clearTypeHierarchy();
     void onItemActivated(const QModelIndex &index);
 
@@ -91,7 +100,10 @@ private:
     QStandardItemModel *m_model = nullptr;
     Utils::AnnotatedItemDelegate *m_delegate = nullptr;
     TextEditor::TextEditorLinkLabel *m_inspectedClass = nullptr;
-    QLabel *m_noTypeHierarchyAvailableLabel = nullptr;
+    QLabel *m_infoLabel = nullptr;
+    QFuture<QSharedPointer<CppTools::CppElement>> m_future;
+    QFutureWatcher<QSharedPointer<CppTools::CppElement>> m_futureWatcher;
+    Utils::ProgressIndicator *m_progressIndicator = nullptr;
 };
 
 class CppTypeHierarchyFactory : public Core::INavigationWidgetFactory

src/plugins/cpptools/cppelementevaluator.cpp

@@ -36,6 +36,8 @@
 #include <cplusplus/Icons.h>
 #include <cplusplus/TypeOfExpression.h>
 
+#include <utils/runextensions.h>
+
 #include <QDir>
 #include <QSet>
 #include <QQueue>
@@ -44,6 +46,14 @@ using namespace CPlusPlus;
 
 namespace CppTools {
 
+static void handleLookupItemMatch(QFutureInterface<QSharedPointer<CppElement>> &futureInterface,
+                                  const Snapshot &snapshot,
+                                  const LookupItem &lookupItem,
+                                  const LookupContext &context,
+                                  CppTools::SymbolFinder symbolFinder,
+                                  bool lookupBaseClasses,
+                                  bool lookupDerivedClasses);
+
 static QStringList stripName(const QString &name)
 {
     QStringList all;
@@ -164,7 +174,8 @@ CppClass *CppClass::toCppClass()
     return this;
 }
 
-void CppClass::lookupBases(Symbol *declaration, const LookupContext &context)
+void CppClass::lookupBases(QFutureInterfaceBase &futureInterface,
+                           Symbol *declaration, const LookupContext &context)
 {
     using Data = QPair<ClassOrNamespace*, CppClass*>;
 
@@ -174,6 +185,8 @@ void CppClass::lookupBases(Symbol *declaration, const LookupContext &context)
         QQueue<Data> q;
         q.enqueue(qMakePair(clazz, this));
         while (!q.isEmpty()) {
+            if (futureInterface.isCanceled())
+                return;
             Data current = q.dequeue();
             clazz = current.first;
             visited.insert(clazz);
@@ -195,16 +208,19 @@ void CppClass::lookupBases(Symbol *declaration, const LookupContext &context)
     }
 }
 
-void CppClass::lookupDerived(Symbol *declaration, const Snapshot &snapshot)
+void CppClass::lookupDerived(QFutureInterfaceBase &futureInterface,
+                             Symbol *declaration, const Snapshot &snapshot)
 {
     using Data = QPair<CppClass*, CppTools::TypeHierarchy>;
 
     CppTools::TypeHierarchyBuilder builder(declaration, snapshot);
-    const CppTools::TypeHierarchy &completeHierarchy = builder.buildDerivedTypeHierarchy();
+    const CppTools::TypeHierarchy &completeHierarchy = builder.buildDerivedTypeHierarchy(futureInterface);
 
     QQueue<Data> q;
     q.enqueue(qMakePair(this, completeHierarchy));
     while (!q.isEmpty()) {
+        if (futureInterface.isCanceled())
+            return;
         const Data &current = q.dequeue();
         CppClass *clazz = current.first;
         const CppTools::TypeHierarchy &classHierarchy = current.second;
@@ -345,18 +361,43 @@ void CppElementEvaluator::setLookupBaseClasses(const bool lookup)
 void CppElementEvaluator::setLookupDerivedClasses(const bool lookup)
 { m_lookupDerivedClasses = lookup; }
 
-// @todo: Consider refactoring code from CppEditor::findLinkAt into here.
+//  special case for bug QTCREATORBUG-4780
+static bool shouldOmitElement(const LookupItem &lookupItem, const Scope *scope)
+{
+    return !lookupItem.declaration() && scope && scope->isFunction()
+            && lookupItem.type().match(scope->asFunction()->returnType());
+}
+
 void CppElementEvaluator::execute()
+{
+    execute(&CppElementEvaluator::syncExec);
+}
+
+QFuture<QSharedPointer<CppElement>> CppElementEvaluator::asyncExecute()
+{
+    return execute(&CppElementEvaluator::asyncExec);
+}
+
+static QFuture<QSharedPointer<CppElement>> createFinishedFuture()
+{
+    QFutureInterface<QSharedPointer<CppElement>> futureInterface;
+    futureInterface.reportStarted();
+    futureInterface.reportFinished();
+    return futureInterface.future();
+}
+
+// @todo: Consider refactoring code from CppEditor::findLinkAt into here.
+QFuture<QSharedPointer<CppElement>> CppElementEvaluator::execute(ExecFunction execFuntion)
 {
     clear();
 
     if (!m_modelManager)
-        return;
+        return createFinishedFuture();
 
     const Snapshot &snapshot = m_modelManager->snapshot();
     Document::Ptr doc = snapshot.document(m_editor->textDocument()->filePath());
     if (!doc)
-        return;
+        return createFinishedFuture();
 
     int line = 0;
     int column = 0;
@@ -365,7 +406,9 @@ void CppElementEvaluator::execute()
 
     checkDiagnosticMessage(pos);
 
-    if (!matchIncludeFile(doc, line) && !matchMacroInUse(doc, pos)) {
+    if (matchIncludeFile(doc, line) || matchMacroInUse(doc, pos))
+        return createFinishedFuture();
+
     CppTools::moveCursorToEndOfIdentifier(&m_tc);
 
     // Fetch the expression's code
@@ -379,11 +422,36 @@ void CppElementEvaluator::execute()
     typeOfExpression.setExpandTemplates(true);
     const QList<LookupItem> &lookupItems = typeOfExpression(expression.toUtf8(), scope);
     if (lookupItems.isEmpty())
-            return;
+        return createFinishedFuture();
 
     const LookupItem &lookupItem = lookupItems.first(); // ### TODO: select best candidate.
-        handleLookupItemMatch(snapshot, lookupItem, typeOfExpression.context(), scope);
+    if (shouldOmitElement(lookupItem, scope))
+        return createFinishedFuture();
+    return std::invoke(execFuntion, this, snapshot, lookupItem, typeOfExpression.context());
 }
+
+QFuture<QSharedPointer<CppElement>> CppElementEvaluator::syncExec(
+        const CPlusPlus::Snapshot &snapshot, const CPlusPlus::LookupItem &lookupItem,
+        const CPlusPlus::LookupContext &lookupContext)
+{
+    QFutureInterface<QSharedPointer<CppElement>> futureInterface;
+    futureInterface.reportStarted();
+    handleLookupItemMatch(futureInterface, snapshot, lookupItem, lookupContext,
+                          *m_modelManager->symbolFinder(),
+                          m_lookupBaseClasses, m_lookupDerivedClasses);
+    futureInterface.reportFinished();
+    QFuture<QSharedPointer<CppElement>> future = futureInterface.future();
+    m_element = future.result();
+    return future;
+}
+
+QFuture<QSharedPointer<CppElement>> CppElementEvaluator::asyncExec(
+        const CPlusPlus::Snapshot &snapshot, const CPlusPlus::LookupItem &lookupItem,
+        const CPlusPlus::LookupContext &lookupContext)
+{
+    return Utils::runAsync(&handleLookupItemMatch, snapshot, lookupItem, lookupContext,
+                           *m_modelManager->symbolFinder(),
+                           m_lookupBaseClasses, m_lookupDerivedClasses);
 }
 
 void CppElementEvaluator::checkDiagnosticMessage(int pos)
@@ -422,24 +490,25 @@ bool CppElementEvaluator::matchMacroInUse(const Document::Ptr &document, int pos
     return false;
 }
 
-void CppElementEvaluator::handleLookupItemMatch(const Snapshot &snapshot,
+static void handleLookupItemMatch(QFutureInterface<QSharedPointer<CppElement>> &futureInterface,
+                                  const Snapshot &snapshot,
                                   const LookupItem &lookupItem,
                                   const LookupContext &context,
-                                                const Scope *scope)
+                                  CppTools::SymbolFinder symbolFinder,
+                                  bool lookupBaseClasses,
+                                  bool lookupDerivedClasses)
 {
+    if (futureInterface.isCanceled())
+        return;
+    QSharedPointer<CppElement> element;
     Symbol *declaration = lookupItem.declaration();
     if (!declaration) {
         const QString &type = Overview().prettyType(lookupItem.type(), QString());
-        //  special case for bug QTCREATORBUG-4780
+        element = QSharedPointer<CppElement>(new Unknown(type));
-        if (scope && scope->isFunction()
-                && lookupItem.type().match(scope->asFunction()->returnType())) {
-            return;
-        }
-        m_element = QSharedPointer<CppElement>(new Unknown(type));
     } else {
         const FullySpecifiedType &type = declaration->type();
         if (declaration->isNamespace()) {
-            m_element = QSharedPointer<CppElement>(new CppNamespace(declaration));
+            element = QSharedPointer<CppElement>(new CppNamespace(declaration));
         } else if (declaration->isClass()
                    || declaration->isForwardClassDeclaration()
                    || (declaration->isTemplate() && declaration->asTemplate()->declaration()
@@ -447,8 +516,7 @@ void CppElementEvaluator::handleLookupItemMatch(const Snapshot &snapshot,
                            || declaration->asTemplate()->declaration()->isForwardClassDeclaration()))) {
             LookupContext contextToUse = context;
             if (declaration->isForwardClassDeclaration()) {
-                const auto symbolFinder = m_modelManager->symbolFinder();
+                Symbol *classDeclaration = symbolFinder.findMatchingClassDeclaration(declaration,
-                Symbol *classDeclaration = symbolFinder->findMatchingClassDeclaration(declaration,
                                                                                       snapshot);
                 if (classDeclaration) {
                     declaration = classDeclaration;
@@ -460,29 +528,36 @@ void CppElementEvaluator::handleLookupItemMatch(const Snapshot &snapshot,
                 }
             }
 
+            if (futureInterface.isCanceled())
+                return;
             auto cppClass = new CppClass(declaration);
-            if (m_lookupBaseClasses)
+            if (lookupBaseClasses)
-                cppClass->lookupBases(declaration, contextToUse);
+                cppClass->lookupBases(futureInterface, declaration, contextToUse);
-            if (m_lookupDerivedClasses)
+            if (futureInterface.isCanceled())
-                cppClass->lookupDerived(declaration, snapshot);
+                return;
-            m_element = QSharedPointer<CppElement>(cppClass);
+            if (lookupDerivedClasses)
+                cppClass->lookupDerived(futureInterface, declaration, snapshot);
+            if (futureInterface.isCanceled())
+                return;
+            element = QSharedPointer<CppElement>(cppClass);
         } else if (Enum *enumDecl = declaration->asEnum()) {
-            m_element = QSharedPointer<CppElement>(new CppEnum(enumDecl));
+            element = QSharedPointer<CppElement>(new CppEnum(enumDecl));
         } else if (auto enumerator = dynamic_cast<EnumeratorDeclaration *>(declaration)) {
-            m_element = QSharedPointer<CppElement>(new CppEnumerator(enumerator));
+            element = QSharedPointer<CppElement>(new CppEnumerator(enumerator));
         } else if (declaration->isTypedef()) {
-            m_element = QSharedPointer<CppElement>(new CppTypedef(declaration));
+            element = QSharedPointer<CppElement>(new CppTypedef(declaration));
         } else if (declaration->isFunction()
                    || (type.isValid() && type->isFunctionType())
                    || declaration->isTemplate()) {
-            m_element = QSharedPointer<CppElement>(new CppFunction(declaration));
+            element = QSharedPointer<CppElement>(new CppFunction(declaration));
         } else if (declaration->isDeclaration() && type.isValid()) {
-            m_element = QSharedPointer<CppElement>(
+            element = QSharedPointer<CppElement>(
                 new CppVariable(declaration, context, lookupItem.scope()));
         } else {
-            m_element = QSharedPointer<CppElement>(new CppDeclarableElement(declaration));
+            element = QSharedPointer<CppElement>(new CppDeclarableElement(declaration));
         }
     }
+    futureInterface.reportResult(element);
 }
 
 bool CppElementEvaluator::identifiedCppElement() const

src/plugins/cpptools/cppelementevaluator.h

@@ -32,11 +32,12 @@
 
 #include <cplusplus/CppDocument.h>
 
+#include <QFuture>
+#include <QIcon>
+#include <QSharedPointer>
 #include <QString>
 #include <QStringList>
-#include <QSharedPointer>
 #include <QTextCursor>
-#include <QIcon>
 
 namespace CPlusPlus {
 class LookupItem;
@@ -57,6 +58,7 @@ public:
     void setLookupDerivedClasses(const bool lookup);
 
     void execute();
+    QFuture<QSharedPointer<CppElement>> asyncExecute();
     bool identifiedCppElement() const;
     const QSharedPointer<CppElement> &cppElement() const;
     bool hasDiagnosis() const;
@@ -64,13 +66,18 @@ public:
 
 private:
     void clear();
+    using ExecFunction = QFuture<QSharedPointer<CppElement>>(CppElementEvaluator::*)
+                (const CPlusPlus::Snapshot &, const CPlusPlus::LookupItem &,
+                 const CPlusPlus::LookupContext &);
+
+    QFuture<QSharedPointer<CppElement>> execute(ExecFunction execFuntion);
+    QFuture<QSharedPointer<CppElement>> syncExec(const CPlusPlus::Snapshot &,
+                     const CPlusPlus::LookupItem &, const CPlusPlus::LookupContext &);
+    QFuture<QSharedPointer<CppElement>> asyncExec(const CPlusPlus::Snapshot &,
+                     const CPlusPlus::LookupItem &, const CPlusPlus::LookupContext &);
     void checkDiagnosticMessage(int pos);
     bool matchIncludeFile(const CPlusPlus::Document::Ptr &document, int line);
     bool matchMacroInUse(const CPlusPlus::Document::Ptr &document, int pos);
-    void handleLookupItemMatch(const CPlusPlus::Snapshot &snapshot,
-                               const CPlusPlus::LookupItem &lookupItem,
-                               const CPlusPlus::LookupContext &lookupContext,
-                               const CPlusPlus::Scope *scope);
 
     TextEditor::TextEditorWidget *m_editor;
     CppTools::CppModelManager *m_modelManager;
@@ -123,8 +130,10 @@ public:
 
     CppClass *toCppClass() final;
 
-    void lookupBases(CPlusPlus::Symbol *declaration, const CPlusPlus::LookupContext &context);
+    void lookupBases(QFutureInterfaceBase &futureInterface,
-    void lookupDerived(CPlusPlus::Symbol *declaration, const CPlusPlus::Snapshot &snapshot);
+                     CPlusPlus::Symbol *declaration, const CPlusPlus::LookupContext &context);
+    void lookupDerived(QFutureInterfaceBase &futureInterface,
+                       CPlusPlus::Symbol *declaration, const CPlusPlus::Snapshot &snapshot);
 
 public:
     QList<CppClass> bases;

src/plugins/cpptools/typehierarchybuilder.cpp

@@ -52,7 +52,7 @@ public:
     bool visit(CPlusPlus::Class *) override;
 
     const QList<CPlusPlus::Symbol *> &derived() { return _derived; }
-    const QStringList otherBases() { return _otherBases; }
+    const QSet<QString> otherBases() { return _otherBases; }
 
 private:
     CPlusPlus::LookupContext _context;
@@ -60,7 +60,7 @@ private:
     QString _unqualifiedName;
     CPlusPlus::Overview _overview;
     QHash<CPlusPlus::Symbol *, QString> _actualBases;
-    QStringList _otherBases;
+    QSet<QString> _otherBases;
     QList<CPlusPlus::Symbol *> _derived;
 };
 
@@ -111,7 +111,7 @@ bool DerivedHierarchyVisitor::visit(CPlusPlus::Class *symbol)
         if (_qualifiedName == baseName)
             _derived.append(symbol);
         else
-            _otherBases.append(baseName);
+            _otherBases.insert(baseName);
     }
 
     return true;
@@ -146,15 +146,22 @@ void TypeHierarchyBuilder::reset()
 }
 
 TypeHierarchy TypeHierarchyBuilder::buildDerivedTypeHierarchy()
+{
+    QFutureInterfaceBase dummy;
+    return buildDerivedTypeHierarchy(dummy);
+}
+
+TypeHierarchy TypeHierarchyBuilder::buildDerivedTypeHierarchy(QFutureInterfaceBase &futureInterface)
 {
     reset();
     TypeHierarchy hierarchy(_symbol);
-    buildDerived(&hierarchy, filesDependingOn(_symbol));
+    buildDerived(futureInterface, &hierarchy, filesDependingOn(_symbol));
     return hierarchy;
 }
 
-void TypeHierarchyBuilder::buildDerived(TypeHierarchy *typeHierarchy,
+void TypeHierarchyBuilder::buildDerived(QFutureInterfaceBase &futureInterface,
-                                        const QStringList &dependingFiles)
+                                        TypeHierarchy *typeHierarchy,
+                                        const QStringList &dependingFiles, int depth)
 {
     CPlusPlus::Symbol *symbol = typeHierarchy->_symbol;
     if (_visited.contains(symbol))
@@ -165,7 +172,15 @@ void TypeHierarchyBuilder::buildDerived(TypeHierarchy *typeHierarchy,
     const QString &symbolName = _overview.prettyName(CPlusPlus::LookupContext::fullyQualifiedName(symbol));
     DerivedHierarchyVisitor visitor(symbolName);
 
-    foreach (const QString &fileName, dependingFiles) {
+    if (depth == 0)
+        futureInterface.setProgressRange(0, dependingFiles.size());
+
+    int i = -1;
+    for (const QString &fileName : dependingFiles) {
+        if (futureInterface.isCanceled())
+            return;
+        if (depth == 0)
+            futureInterface.setProgressValue(++i);
         CPlusPlus::Document::Ptr doc = _snapshot.document(fileName);
         if ((_candidates.contains(fileName) && !_candidates.value(fileName).contains(symbolName))
                 || !doc->control()->findIdentifier(symbol->identifier()->chars(),
@@ -174,14 +189,14 @@ void TypeHierarchyBuilder::buildDerived(TypeHierarchy *typeHierarchy,
         }
 
         visitor.execute(doc, _snapshot);
-        _candidates.insert(fileName, QSet<QString>());
+        _candidates.insert(fileName, visitor.otherBases());
 
-        foreach (const QString &candidate, visitor.otherBases())
+        const QList<CPlusPlus::Symbol *> &derived = visitor.derived();
-            _candidates[fileName].insert(candidate);
+        for (CPlusPlus::Symbol *s : derived) {
-
-        foreach (CPlusPlus::Symbol *s, visitor.derived()) {
             TypeHierarchy derivedHierarchy(s);
-            buildDerived(&derivedHierarchy, filesDependingOn(s));
+            buildDerived(futureInterface, &derivedHierarchy, filesDependingOn(s), depth + 1);
+            if (futureInterface.isCanceled())
+                return;
             typeHierarchy->_hierarchy.append(derivedHierarchy);
         }
     }
@@ -193,9 +208,10 @@ QStringList TypeHierarchyBuilder::filesDependingOn(CPlusPlus::Symbol *symbol) co
     if (!symbol)
         return deps;
 
-    Utils::FilePath file = Utils::FilePath::fromUtf8(symbol->fileName(), symbol->fileNameLength());
+    const Utils::FilePath file = Utils::FilePath::fromUtf8(symbol->fileName(), symbol->fileNameLength());
     deps << file.toString();
-    foreach (const Utils::FilePath &fileName, _snapshot.filesDependingOn(file))
+    const Utils::FilePaths filePaths = _snapshot.filesDependingOn(file);
+    for (const Utils::FilePath &fileName : filePaths)
         deps.append(fileName.toString());
     return deps;
 }

src/plugins/cpptools/typehierarchybuilder.h

@@ -30,6 +30,7 @@
 #include <cplusplus/CppDocument.h>
 #include <cplusplus/Overview.h>
 
+#include <QFutureInterface>
 #include <QList>
 #include <QSet>
 
@@ -60,10 +61,12 @@ public:
     TypeHierarchyBuilder(CPlusPlus::Symbol *symbol, const CPlusPlus::Snapshot &snapshot);
 
     TypeHierarchy buildDerivedTypeHierarchy();
+    TypeHierarchy buildDerivedTypeHierarchy(QFutureInterfaceBase &futureInterface);
 
 private:
     void reset();
-    void buildDerived(TypeHierarchy *typeHierarchy, const QStringList &dependencies);
+    void buildDerived(QFutureInterfaceBase &futureInterface,
+                      TypeHierarchy *typeHierarchy, const QStringList &dependencies, int depth = 0);
     QStringList filesDependingOn(CPlusPlus::Symbol *symbol) const;
 
     CPlusPlus::Symbol *_symbol;