Clang: Provide tooltips

This includes also the query data for the help system (F1) for an
identifier under cursor.

Regressions (libclang changes necessary):
 - Function signatures do not contain default values.
 - Aliases are not resolved for/at:
   - template types
   - qualified name of a type

Fixes/Improvements:
 - Resolve "auto"
 - On a template type, show also the template parameter.
 - For a typedef like
     typedef long long superlong;
   the tooltip was "long long superlong", which was confusing.
   Now, "long long" is shown.

New:
 - Show first or \brief paragraph of a documentation comment.
 - Show size of a class at definition.
 - Show size of a field member in class definition.

Task-number: QTCREATORBUG-11259
Change-Id: Ie1a07930d0e882015d07dc43e35bb81a685cdeb8
Reviewed-by: Marco Bubke <marco.bubke@qt.io>

13 files changed, 421 insertions, 6 deletions

diff --git a/src/plugins/clangcodemodel/clangbackendcommunicator.cpp b/src/plugins/clangcodemodel/clangbackendcommunicator.cpp
index 5650479312..1abd6982ed 100644
--- a/src/plugins/clangcodemodel/clangbackendcommunicator.cpp
+++ b/src/plugins/clangcodemodel/clangbackendcommunicator.cpp
@@ -392,6 +392,15 @@ QFuture<CppTools::CursorInfo> BackendCommunicator::requestLocalReferences(
     return m_receiver.addExpectedReferencesMessage(message.ticketNumber(), textDocument);
 }
 
+QFuture<CppTools::ToolTipInfo> BackendCommunicator::requestToolTip(
+        const FileContainer &fileContainer, quint32 line, quint32 column)
+{
+    const RequestToolTipMessage message(fileContainer, line, column);
+    m_sender->requestToolTip(message);
+
+    return m_receiver.addExpectedToolTipMessage(message.ticketNumber());
+}
+
 QFuture<CppTools::SymbolInfo> BackendCommunicator::requestFollowSymbol(
         const FileContainer &curFileContainer,
         quint32 line,
diff --git a/src/plugins/clangcodemodel/clangbackendcommunicator.h b/src/plugins/clangcodemodel/clangbackendcommunicator.h
index bd7494a6c2..b3cb166a39 100644
--- a/src/plugins/clangcodemodel/clangbackendcommunicator.h
+++ b/src/plugins/clangcodemodel/clangbackendcommunicator.h
@@ -82,6 +82,9 @@ public:
             quint32 line,
             quint32 column,
             QTextDocument *textDocument);
+    QFuture<CppTools::ToolTipInfo> requestToolTip(const FileContainer &fileContainer,
+                                                  quint32 line,
+                                                  quint32 column);
     QFuture<CppTools::SymbolInfo> requestFollowSymbol(const FileContainer &curFileContainer,
                                                       quint32 line,
                                                       quint32 column);
diff --git a/src/plugins/clangcodemodel/clangbackendreceiver.cpp b/src/plugins/clangcodemodel/clangbackendreceiver.cpp
index 8d5ec92d00..f2606d74cc 100644
--- a/src/plugins/clangcodemodel/clangbackendreceiver.cpp
+++ b/src/plugins/clangcodemodel/clangbackendreceiver.cpp
@@ -128,6 +128,18 @@ QFuture<CppTools::SymbolInfo> BackendReceiver::addExpectedRequestFollowSymbolMes
     return futureInterface.future();
 }
 
+QFuture<CppTools::ToolTipInfo> BackendReceiver::addExpectedToolTipMessage(quint64 ticket)
+{
+    QTC_CHECK(!m_toolTipsTable.contains(ticket));
+
+    QFutureInterface<CppTools::ToolTipInfo> futureInterface;
+    futureInterface.reportStarted();
+
+    m_toolTipsTable.insert(ticket, futureInterface);
+
+    return futureInterface.future();
+}
+
 bool BackendReceiver::isExpectingCodeCompletedMessage() const
 {
     return !m_assistProcessorsTable.isEmpty();
@@ -272,6 +284,72 @@ void BackendReceiver::references(const ReferencesMessage &message)
     futureInterface.reportFinished();
 }
 
+static TextEditor::HelpItem::Category toHelpItemCategory(ToolTipInfo::QdocCategory category)
+{
+    switch (category) {
+    case ToolTipInfo::Unknown:
+        return TextEditor::HelpItem::Unknown;
+    case ToolTipInfo::ClassOrNamespace:
+        return TextEditor::HelpItem::ClassOrNamespace;
+    case ToolTipInfo::Enum:
+        return TextEditor::HelpItem::Enum;
+    case ToolTipInfo::Typedef:
+        return TextEditor::HelpItem::Typedef;
+    case ToolTipInfo::Macro:
+        return TextEditor::HelpItem::Macro;
+    case ToolTipInfo::Brief:
+        return TextEditor::HelpItem::Brief;
+    case ToolTipInfo::Function:
+        return TextEditor::HelpItem::Function;
+    }
+
+    return TextEditor::HelpItem::Unknown;
+}
+
+static QStringList toStringList(const Utf8StringVector &utf8StringVector)
+{
+    QStringList list;
+    list.reserve(utf8StringVector.size());
+
+    for (const Utf8String &utf8String : utf8StringVector)
+        list << utf8String.toString();
+
+    return list;
+}
+
+static CppTools::ToolTipInfo toToolTipInfo(const ToolTipMessage &message)
+{
+    CppTools::ToolTipInfo info;
+
+    const ToolTipInfo backendInfo = message.toolTipInfo();
+
+    info.text = backendInfo.text();
+    info.briefComment = backendInfo.briefComment();
+
+    info.qDocIdCandidates = toStringList(backendInfo.qdocIdCandidates());
+    info.qDocMark = backendInfo.qdocMark();
+    info.qDocCategory = toHelpItemCategory(backendInfo.qdocCategory());
+
+    info.sizeInBytes = backendInfo.sizeInBytes();
+
+    return info;
+}
+
+void BackendReceiver::tooltip(const ToolTipMessage &message)
+{
+    qCDebugIpc() << "ToolTipMessage" << message.toolTipInfo().text();
+
+    const quint64 ticket = message.ticketNumber();
+    QFutureInterface<CppTools::ToolTipInfo> futureInterface = m_toolTipsTable.take(ticket);
+    QTC_CHECK(futureInterface != QFutureInterface<CppTools::ToolTipInfo>());
+
+    if (futureInterface.isCanceled())
+        return; // A new request was issued making this one outdated.
+
+    futureInterface.reportResult(toToolTipInfo(message));
+    futureInterface.reportFinished();
+}
+
 void BackendReceiver::followSymbol(const ClangBackEnd::FollowSymbolMessage &message)
 {
     qCDebugIpc() << "FollowSymbolMessage with"
diff --git a/src/plugins/clangcodemodel/clangbackendreceiver.h b/src/plugins/clangcodemodel/clangbackendreceiver.h
index d7a966eae9..921150a52d 100644
--- a/src/plugins/clangcodemodel/clangbackendreceiver.h
+++ b/src/plugins/clangcodemodel/clangbackendreceiver.h
@@ -27,6 +27,7 @@
 
 #include <cpptools/cppcursorinfo.h>
 #include <cpptools/cppsymbolinfo.h>
+#include <cpptools/baseeditordocumentprocessor.h>
 
 #include <clangsupport/clangcodemodelclientinterface.h>
 
@@ -59,6 +60,7 @@ public:
                                  const CppTools::SemanticInfo::LocalUseMap &localUses
                                      = CppTools::SemanticInfo::LocalUseMap());
     QFuture<CppTools::SymbolInfo> addExpectedRequestFollowSymbolMessage(quint64 ticket);
+    QFuture<CppTools::ToolTipInfo> addExpectedToolTipMessage(quint64 ticket);
     bool isExpectingCodeCompletedMessage() const;
 
     void reset();
@@ -70,6 +72,7 @@ private:
 
     void documentAnnotationsChanged(const ClangBackEnd::DocumentAnnotationsChangedMessage &message) override;
     void references(const ClangBackEnd::ReferencesMessage &message) override;
+    void tooltip(const ClangBackEnd::ToolTipMessage &message) override;
     void followSymbol(const ClangBackEnd::FollowSymbolMessage &message) override;
 
 private:
@@ -89,7 +92,7 @@ private:
         CppTools::SemanticInfo::LocalUseMap localUses;
     };
     QHash<quint64, ReferencesEntry> m_referencesTable;
-
+    QHash<quint64, QFutureInterface<CppTools::ToolTipInfo>> m_toolTipsTable;
     QHash<quint64, QFutureInterface<CppTools::SymbolInfo>> m_followTable;
 };
 
diff --git a/src/plugins/clangcodemodel/clangbackendsender.cpp b/src/plugins/clangcodemodel/clangbackendsender.cpp
index 089377083f..f6f8aea1cf 100644
--- a/src/plugins/clangcodemodel/clangbackendsender.cpp
+++ b/src/plugins/clangcodemodel/clangbackendsender.cpp
@@ -120,6 +120,13 @@ void BackendSender::requestReferences(const RequestReferencesMessage &message)
     m_connection->serverProxy().requestReferences(message);
 }
 
+void BackendSender::requestToolTip(const RequestToolTipMessage &message)
+{
+    QTC_CHECK(m_connection->isConnected());
+    qCDebug(ipcLog) << ">>>" << message;
+    m_connection->serverProxy().requestToolTip(message);
+}
+
 void BackendSender::requestFollowSymbol(const RequestFollowSymbolMessage &message)
 {
     QTC_CHECK(m_connection->isConnected());
diff --git a/src/plugins/clangcodemodel/clangbackendsender.h b/src/plugins/clangcodemodel/clangbackendsender.h
index ca9238ae65..f01326a4dc 100644
--- a/src/plugins/clangcodemodel/clangbackendsender.h
+++ b/src/plugins/clangcodemodel/clangbackendsender.h
@@ -48,6 +48,7 @@ public:
     void completeCode(const ClangBackEnd::CompleteCodeMessage &message) override;
     void requestDocumentAnnotations(const ClangBackEnd::RequestDocumentAnnotationsMessage &message) override;
     void requestReferences(const ClangBackEnd::RequestReferencesMessage &message) override;
+    void requestToolTip(const ClangBackEnd::RequestToolTipMessage &message) override;
     void requestFollowSymbol(const ClangBackEnd::RequestFollowSymbolMessage &message) override;
     void updateVisibleTranslationUnits(const ClangBackEnd::UpdateVisibleTranslationUnitsMessage &message) override;
 
diff --git a/src/plugins/clangcodemodel/clangcodemodel.pro b/src/plugins/clangcodemodel/clangcodemodel.pro
index 9136db5db5..0e444a350e 100644
--- a/src/plugins/clangcodemodel/clangcodemodel.pro
+++ b/src/plugins/clangcodemodel/clangcodemodel.pro
@@ -30,6 +30,7 @@ SOURCES += \
     clangfixitoperationsextractor.cpp \
     clangfollowsymbol.cpp \
     clangfunctionhintmodel.cpp \
+    clanghoverhandler.cpp \
     clangtokeninfosreporter.cpp \
     clangmodelmanagersupport.cpp \
     clangpreprocessorassistproposalitem.cpp \
@@ -66,6 +67,7 @@ HEADERS += \
     clangfixitoperationsextractor.h \
     clangfollowsymbol.h \
     clangfunctionhintmodel.h \
+    clanghoverhandler.h \
     clangisdiagnosticrelatedtolocation.h \
     clangmodelmanagersupport.h \
     clangpreprocessorassistproposalitem.h \
diff --git a/src/plugins/clangcodemodel/clangcodemodel.qbs b/src/plugins/clangcodemodel/clangcodemodel.qbs
index cc81025925..90105b86d3 100644
--- a/src/plugins/clangcodemodel/clangcodemodel.qbs
+++ b/src/plugins/clangcodemodel/clangcodemodel.qbs
@@ -80,6 +80,8 @@ QtcPlugin {
         "clangfollowsymbol.h",
         "clangfunctionhintmodel.cpp",
         "clangfunctionhintmodel.h",
+        "clanghoverhandler.cpp",
+        "clanghoverhandler.h",
         "clangtokeninfosreporter.cpp",
         "clangtokeninfosreporter.h",
         "clangisdiagnosticrelatedtolocation.h",
diff --git a/src/plugins/clangcodemodel/clangeditordocumentprocessor.cpp b/src/plugins/clangcodemodel/clangeditordocumentprocessor.cpp
index 6eb98b2c92..a282350f24 100644
--- a/src/plugins/clangcodemodel/clangeditordocumentprocessor.cpp
+++ b/src/plugins/clangcodemodel/clangeditordocumentprocessor.cpp
@@ -375,6 +375,15 @@ ClangEditorDocumentProcessor::requestFollowSymbol(int line, int column)
                                               static_cast<quint32>(column));
 }
 
+QFuture<CppTools::ToolTipInfo> ClangEditorDocumentProcessor::toolTipInfo(const QByteArray &codecName,
+                                                                         int line,
+                                                                         int column)
+{
+    return m_communicator.requestToolTip(simpleFileContainer(codecName),
+                                         static_cast<quint32>(line),
+                                         static_cast<quint32>(column));
+}
+
 ClangBackEnd::FileContainer ClangEditorDocumentProcessor::fileContainerWithArguments() const
 {
     return fileContainerWithArguments(m_projectPart.data());
@@ -480,13 +489,19 @@ ClangEditorDocumentProcessor::creatorForHeaderErrorDiagnosticWidget(
     };
 }
 
-ClangBackEnd::FileContainer ClangEditorDocumentProcessor::simpleFileContainer() const
+ClangBackEnd::FileContainer ClangEditorDocumentProcessor::simpleFileContainer(
+    const QByteArray &codecName) const
 {
     Utf8String projectPartId;
     if (m_projectPart)
         projectPartId = m_projectPart->id();
 
-    return ClangBackEnd::FileContainer(filePath(), projectPartId, Utf8String(), false, revision());
+    return ClangBackEnd::FileContainer(filePath(),
+                                       projectPartId,
+                                       Utf8String(),
+                                       false,
+                                       revision(),
+                                       Utf8String::fromByteArray(codecName));
 }
 
 static CppTools::ProjectPart projectPartForLanguageOption(CppTools::ProjectPart *projectPart)
diff --git a/src/plugins/clangcodemodel/clangeditordocumentprocessor.h b/src/plugins/clangcodemodel/clangeditordocumentprocessor.h
index 2bb7ca0463..67745b582c 100644
--- a/src/plugins/clangcodemodel/clangeditordocumentprocessor.h
+++ b/src/plugins/clangcodemodel/clangeditordocumentprocessor.h
@@ -88,6 +88,9 @@ public:
     QFuture<CppTools::CursorInfo> cursorInfo(const CppTools::CursorInfoParams &params) override;
     QFuture<CppTools::CursorInfo> requestLocalReferences(const QTextCursor &cursor) override;
     QFuture<CppTools::SymbolInfo> requestFollowSymbol(int line, int column) override;
+    QFuture<CppTools::ToolTipInfo> toolTipInfo(const QByteArray &codecName,
+                                               int line,
+                                               int column) override;
 
     ClangBackEnd::FileContainer fileContainerWithArguments() const;
 
@@ -106,7 +109,7 @@ private:
     void requestDocumentAnnotations(const QString &projectpartId);
     HeaderErrorDiagnosticWidgetCreator creatorForHeaderErrorDiagnosticWidget(
             const ClangBackEnd::DiagnosticContainer &firstHeaderErrorDiagnostic);
-    ClangBackEnd::FileContainer simpleFileContainer() const;
+    ClangBackEnd::FileContainer simpleFileContainer(const QByteArray &codecName = QByteArray()) const;
     ClangBackEnd::FileContainer fileContainerWithArguments(CppTools::ProjectPart *projectPart) const;
     ClangBackEnd::FileContainer fileContainerWithArgumentsAndDocumentContent(
             CppTools::ProjectPart *projectPart) const;
diff --git a/src/plugins/clangcodemodel/clanghoverhandler.cpp b/src/plugins/clangcodemodel/clanghoverhandler.cpp
new file mode 100644
index 0000000000..6610b555c2
--- /dev/null
+++ b/src/plugins/clangcodemodel/clanghoverhandler.cpp
@@ -0,0 +1,232 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include "clanghoverhandler.h"
+
+#include <coreplugin/helpmanager.h>
+#include <cpptools/baseeditordocumentprocessor.h>
+#include <cpptools/cppmodelmanager.h>
+#include <cpptools/editordocumenthandle.h>
+#include <texteditor/texteditor.h>
+
+#include <utils/qtcassert.h>
+#include <utils/textutils.h>
+#include <utils/tooltip/tooltip.h>
+
+#include <QFutureWatcher>
+#include <QLoggingCategory>
+#include <QTextCodec>
+#include <QVBoxLayout>
+
+Q_LOGGING_CATEGORY(hoverLog, "qtc.clangcodemodel.hover");
+
+using namespace TextEditor;
+
+namespace ClangCodeModel {
+namespace Internal {
+
+static CppTools::BaseEditorDocumentProcessor *editorDocumentProcessor(TextEditorWidget *editorWidget)
+{
+    const QString filePath = editorWidget->textDocument()->filePath().toString();
+    auto cppModelManager = CppTools::CppModelManager::instance();
+    CppTools::CppEditorDocumentHandle *editorHandle = cppModelManager->cppEditorDocument(filePath);
+
+    if (editorHandle)
+        return editorHandle->processor();
+
+    return 0;
+}
+
+static bool editorDocumentProcessorHasDiagnosticAt(TextEditorWidget *editorWidget, int pos)
+{
+    if (CppTools::BaseEditorDocumentProcessor *processor = editorDocumentProcessor(editorWidget)) {
+        int line, column;
+        if (Utils::Text::convertPosition(editorWidget->document(), pos, &line, &column))
+            return processor->hasDiagnosticsAt(line, column);
+    }
+
+    return false;
+}
+
+static void processWithEditorDocumentProcessor(TextEditorWidget *editorWidget,
+                                               const QPoint &point,
+                                               int position,
+                                               const QString &helpId)
+{
+    if (CppTools::BaseEditorDocumentProcessor *processor = editorDocumentProcessor(editorWidget)) {
+        int line, column;
+        if (Utils::Text::convertPosition(editorWidget->document(), position, &line, &column)) {
+            auto layout = new QVBoxLayout;
+            layout->setContentsMargins(0, 0, 0, 0);
+            layout->setSpacing(2);
+            processor->addDiagnosticToolTipToLayout(line, column, layout);
+            Utils::ToolTip::show(point, layout, editorWidget, helpId);
+        }
+    }
+}
+
+static QFuture<CppTools::ToolTipInfo> editorDocumentHandlesToolTipInfo(
+    TextEditorWidget *editorWidget, int pos)
+{
+    const QByteArray textCodecName = editorWidget->textDocument()->codec()->name();
+    if (CppTools::BaseEditorDocumentProcessor *processor = editorDocumentProcessor(editorWidget)) {
+        int line, column;
+        if (Utils::Text::convertPosition(editorWidget->document(), pos, &line, &column))
+            return processor->toolTipInfo(textCodecName, line, column + 1);
+    }
+
+    return QFuture<CppTools::ToolTipInfo>();
+}
+
+ClangHoverHandler::ClangHoverHandler()
+{
+    setIsAsyncHandler(true);
+}
+
+ClangHoverHandler::~ClangHoverHandler()
+{
+    cancelAsyncCheck();
+}
+
+void ClangHoverHandler::identifyMatchAsync(TextEditorWidget *editorWidget,
+                                           int pos,
+                                           BaseHoverHandler::ReportPriority report)
+{
+    // Reset
+    m_futureWatcher.reset();
+    m_cursorPosition = -1;
+
+    // Check for diagnostics (sync)
+    if (editorDocumentProcessorHasDiagnosticAt(editorWidget, pos)) {
+        qCDebug(hoverLog) << "Checking for diagnostic at" << pos;
+        setPriority(Priority_Diagnostic);
+        m_cursorPosition = pos;
+        report(priority());
+        return;
+    }
+
+    // Check for tooltips (async)
+    QFuture<CppTools::ToolTipInfo> future = editorDocumentHandlesToolTipInfo(editorWidget, pos);
+    if (QTC_GUARD(future.isRunning())) {
+        qCDebug(hoverLog) << "Requesting tooltip info at" << pos;
+        m_reportPriority = report;
+        m_futureWatcher.reset(new QFutureWatcher<CppTools::ToolTipInfo>());
+        QObject::connect(m_futureWatcher.data(), &QFutureWatcherBase::finished, [this]() {
+            processToolTipInfo(m_futureWatcher->result());
+        });
+        m_futureWatcher->setFuture(future);
+        return;
+    }
+
+    report(Priority_None); // Ops, something went wrong.
+}
+
+void ClangHoverHandler::cancelAsyncCheck()
+{
+    if (m_futureWatcher)
+        m_futureWatcher->cancel();
+}
+
+#define RETURN_TEXT_FOR_CASE(enumValue) case TextEditor::HelpItem::enumValue: return #enumValue
+static const char *helpItemCategoryAsString(TextEditor::HelpItem::Category category)
+{
+    switch (category) {
+        RETURN_TEXT_FOR_CASE(Unknown);
+        RETURN_TEXT_FOR_CASE(ClassOrNamespace);
+        RETURN_TEXT_FOR_CASE(Enum);
+        RETURN_TEXT_FOR_CASE(Typedef);
+        RETURN_TEXT_FOR_CASE(Macro);
+        RETURN_TEXT_FOR_CASE(Brief);
+        RETURN_TEXT_FOR_CASE(Function);
+        RETURN_TEXT_FOR_CASE(QmlComponent);
+        RETURN_TEXT_FOR_CASE(QmlProperty);
+        RETURN_TEXT_FOR_CASE(QMakeVariableOfFunction);
+    }
+
+    return "UnhandledHelpItemCategory";
+}
+#undef RETURN_TEXT_FOR_CASE
+
+void ClangHoverHandler::processToolTipInfo(const CppTools::ToolTipInfo &info)
+{
+    qCDebug(hoverLog) << "Processing tooltip info" << info.text;
+
+    QString text = info.text;
+    if (!info.briefComment.isEmpty())
+        text.append("\n\n" + info.briefComment);
+
+    for (const QString &qdocIdCandidate : info.qDocIdCandidates) {
+        qCDebug(hoverLog) << "Querying help manager with"
+                          << qdocIdCandidate
+                          << info.qDocMark
+                          << helpItemCategoryAsString(info.qDocCategory);
+        const QMap<QString, QUrl> helpLinks = Core::HelpManager::linksForIdentifier(qdocIdCandidate);
+        if (!helpLinks.isEmpty()) {
+            qCDebug(hoverLog) << "  Match!";
+            setLastHelpItemIdentified(
+                HelpItem(qdocIdCandidate, info.qDocMark, info.qDocCategory, helpLinks));
+            break;
+        }
+    }
+
+    if (!info.sizeInBytes.isEmpty())
+        text.append(tr("\n\n%1 bytes").arg(info.sizeInBytes));
+
+    setToolTip(text);
+    m_reportPriority(priority());
+}
+
+void ClangHoverHandler::decorateToolTip()
+{
+    if (priority() == Priority_Diagnostic)
+        return;
+
+    if (Qt::mightBeRichText(toolTip()))
+        setToolTip(toolTip().toHtmlEscaped());
+
+    const HelpItem &help = lastHelpItemIdentified();
+    if (help.isValid()) {
+        const QString text = CppTools::CppHoverHandler::tooltipTextForHelpItem(help);
+        if (!text.isEmpty())
+            setToolTip(text);
+    }
+}
+
+void ClangHoverHandler::operateTooltip(TextEditor::TextEditorWidget *editorWidget,
+                                       const QPoint &point)
+{
+    if (priority() == Priority_Diagnostic) {
+        const HelpItem helpItem = lastHelpItemIdentified();
+        const QString helpId = helpItem.isValid() ? helpItem.helpId() : QString();
+        processWithEditorDocumentProcessor(editorWidget, point, m_cursorPosition, helpId);
+        return;
+    }
+
+    // Priority_Tooltip / Priority_Help
+    BaseHoverHandler::operateTooltip(editorWidget, point);
+}
+
+} // namespace Internal
+} // namespace ClangCodeModel
diff --git a/src/plugins/clangcodemodel/clanghoverhandler.h b/src/plugins/clangcodemodel/clanghoverhandler.h
new file mode 100644
index 0000000000..85b7999f94
--- /dev/null
+++ b/src/plugins/clangcodemodel/clanghoverhandler.h
@@ -0,0 +1,60 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#pragma once
+
+#include <cpptools/baseeditordocumentprocessor.h>
+#include <cpptools/cpphoverhandler.h>
+#include <texteditor/basehoverhandler.h>
+
+namespace ClangCodeModel {
+namespace Internal {
+
+class ClangHoverHandler : public TextEditor::BaseHoverHandler
+{
+    Q_DECLARE_TR_FUNCTIONS(ClangHoverHandler)
+
+public:
+    ClangHoverHandler();
+    ~ClangHoverHandler() override;
+
+    void identifyMatchAsync(TextEditor::TextEditorWidget *editorWidget,
+                            int pos,
+                            ReportPriority report) override;
+    void decorateToolTip() override;
+    void operateTooltip(TextEditor::TextEditorWidget *editorWidget, const QPoint &point) override;
+
+private:
+    void cancelAsyncCheck() override;
+    void processToolTipInfo(const CppTools::ToolTipInfo &info);
+
+private:
+    int m_cursorPosition = -1;
+    QScopedPointer<QFutureWatcher<CppTools::ToolTipInfo>> m_futureWatcher;
+    ReportPriority m_reportPriority;
+};
+
+} // namespace Internal
+} // namespace ClangCodeModel
diff --git a/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp b/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
index 9271975dfd..9495e6d5eb 100644
--- a/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
+++ b/src/plugins/clangcodemodel/clangmodelmanagersupport.cpp
@@ -29,11 +29,11 @@
 #include "clangeditordocumentprocessor.h"
 #include "clangutils.h"
 #include "clangfollowsymbol.h"
+#include "clanghoverhandler.h"
 #include "clangrefactoringengine.h"
 
 #include <coreplugin/editormanager/editormanager.h>
 #include <cpptools/cppfollowsymbolundercursor.h>
-#include <cpptools/cpphoverhandler.h>
 #include <cpptools/cppmodelmanager.h>
 #include <cpptools/editordocumenthandle.h>
 #include <cpptools/projectinfo.h>
@@ -114,7 +114,7 @@ CppTools::CppCompletionAssistProvider *ModelManagerSupportClang::completionAssis
 
 TextEditor::BaseHoverHandler *ModelManagerSupportClang::createHoverHandler()
 {
-    return new CppTools::CppHoverHandler;
+    return new Internal::ClangHoverHandler;
 }
 
 CppTools::FollowSymbolInterface &ModelManagerSupportClang::followSymbolInterface()