C++: Synchronize function decl/def refactoring.

When editing a function declaration or definition the code model
may realize the same changes have to be applied somewhere else. A
refactoring marker will pop up that can be clicked to perform the
changes. Alternatively, press enter to apply.

Change-Id: I2299a2ecfb6a8f87d4853fc7cfa99486f890a1d3
Reviewed-on: http://codereview.qt.nokia.com/2909
Reviewed-by: Leandro T. C. Melo <leandro.melo@nokia.com>

14 files changed, 973 insertions, 92 deletions

diff --git a/src/libs/cplusplus/CppDocument.cpp b/src/libs/cplusplus/CppDocument.cpp
index 4c5fa48ed7e..cb4630d9c9c 100644
--- a/src/libs/cplusplus/CppDocument.cpp
+++ b/src/libs/cplusplus/CppDocument.cpp
@@ -50,6 +50,7 @@
 #include <NameVisitor.h>
 #include <TypeVisitor.h>
 #include <CoreTypes.h>
+#include <LookupContext.h>
 
 #include <QtCore/QByteArray>
 #include <QtCore/QBitArray>
@@ -583,6 +584,8 @@ void Document::check(CheckMode mode)
         semantic(ast, _globalNamespace);
     } else if (ExpressionAST *ast = _translationUnit->ast()->asExpression()) {
         semantic(ast, _globalNamespace);
+    } else if (DeclarationAST *ast = translationUnit()->ast()->asDeclaration()) {
+        semantic(ast, _globalNamespace);
     }
 }
 
@@ -972,7 +975,9 @@ public:
 };
 } // end of anonymous namespace
 
-Symbol *Snapshot::findMatchingDefinition(Symbol *declaration) const
+// strict means the returned symbol has to match exactly,
+// including argument count and argument types
+Symbol *Snapshot::findMatchingDefinition(Symbol *declaration, bool strict) const
 {
     if (!declaration)
         return 0;
@@ -1030,7 +1035,7 @@ Symbol *Snapshot::findMatchingDefinition(Symbol *declaration) const
             if (viableFunctions.isEmpty())
                 continue;
 
-            else if (viableFunctions.length() == 1)
+            else if (! strict && viableFunctions.length() == 1)
                 return viableFunctions.first();
 
             Function *best = 0;
@@ -1039,7 +1044,7 @@ Symbol *Snapshot::findMatchingDefinition(Symbol *declaration) const
                 if (! (fun->unqualifiedName() && fun->unqualifiedName()->isEqualTo(declaration->unqualifiedName())))
                     continue;
                 else if (fun->argumentCount() == declarationTy->argumentCount()) {
-                    if (! best)
+                    if (! strict && ! best)
                         best = fun;
 
                     unsigned argc = 0;
@@ -1055,7 +1060,7 @@ Symbol *Snapshot::findMatchingDefinition(Symbol *declaration) const
                 }
             }
 
-            if (! best)
+            if (!strict && ! best)
                 best = viableFunctions.first();
 
             return best;
@@ -1089,3 +1094,74 @@ Class *Snapshot::findMatchingClassDeclaration(Symbol *declaration) const
 
     return 0;
 }
+
+void CPlusPlus::findMatchingDeclaration(const LookupContext &context,
+                                        Function *functionType,
+                                        QList<Declaration *> *typeMatch,
+                                        QList<Declaration *> *argumentCountMatch,
+                                        QList<Declaration *> *nameMatch)
+{
+    Scope *enclosingScope = functionType->enclosingScope();
+    while (! (enclosingScope->isNamespace() || enclosingScope->isClass()))
+        enclosingScope = enclosingScope->enclosingScope();
+    Q_ASSERT(enclosingScope != 0);
+
+    const Name *functionName = functionType->name();
+    if (! functionName)
+        return; // anonymous function names are not valid c++
+
+    ClassOrNamespace *binding = 0;
+    const QualifiedNameId *qName = functionName->asQualifiedNameId();
+    if (qName) {
+        if (qName->base())
+            binding = context.lookupType(qName->base(), enclosingScope);
+        functionName = qName->name();
+    }
+
+    if (!binding) { // declaration for a global function
+        binding = context.lookupType(enclosingScope);
+
+        if (!binding)
+            return;
+    }
+
+    const Identifier *funcId = functionName->identifier();
+    if (!funcId) // E.g. operator, which we might be able to handle in the future...
+        return;
+
+    foreach (Symbol *s, binding->symbols()) {
+        Class *matchingClass = s->asClass();
+        if (!matchingClass)
+            continue;
+
+        for (Symbol *s = matchingClass->find(funcId); s; s = s->next()) {
+            if (! s->name())
+                continue;
+            else if (! funcId->isEqualTo(s->identifier()))
+                continue;
+            else if (! s->type()->isFunctionType())
+                continue;
+            else if (Declaration *decl = s->asDeclaration()) {
+                if (Function *declFunTy = decl->type()->asFunctionType()) {
+                    if (functionType->isEqualTo(declFunTy))
+                        typeMatch->prepend(decl);
+                    else if (functionType->argumentCount() == declFunTy->argumentCount())
+                        argumentCountMatch->prepend(decl);
+                    else
+                        nameMatch->append(decl);
+                }
+            }
+        }
+    }
+}
+
+QList<Declaration *> CPlusPlus::findMatchingDeclaration(const LookupContext &context, Function *functionType)
+{
+    QList<Declaration *> result;
+    QList<Declaration *> nameMatch, argumentCountMatch, typeMatch;
+    findMatchingDeclaration(context, functionType, &typeMatch, &argumentCountMatch, &nameMatch);
+    result.append(typeMatch);
+    result.append(argumentCountMatch);
+    result.append(nameMatch);
+    return result;
+}
diff --git a/src/libs/cplusplus/CppDocument.h b/src/libs/cplusplus/CppDocument.h
index 92e1e902b30..48d72cad3cb 100644
--- a/src/libs/cplusplus/CppDocument.h
+++ b/src/libs/cplusplus/CppDocument.h
@@ -45,6 +45,7 @@ namespace CPlusPlus {
 
 class Macro;
 class MacroArgumentReference;
+class LookupContext;
 
 class CPLUSPLUS_EXPORT Document
 {
@@ -386,7 +387,7 @@ public:
     Document::Ptr documentFromSource(const QByteArray &preprocessedCode,
                                      const QString &fileName) const;
 
-    Symbol *findMatchingDefinition(Symbol *symbol) const;
+    Symbol *findMatchingDefinition(Symbol *symbol, bool strict = false) const;
     Class *findMatchingClassDeclaration(Symbol *symbol) const;
 
 private:
@@ -396,6 +397,15 @@ private:
     _Base _documents;
 };
 
+void CPLUSPLUS_EXPORT findMatchingDeclaration(
+        const LookupContext &context,
+        Function *functionType,
+        QList<Declaration *> *typeMatch,
+        QList<Declaration *> *argumentCountMatch,
+        QList<Declaration *> *nameMatch);
+QList<Declaration *> CPLUSPLUS_EXPORT findMatchingDeclaration(
+        const LookupContext &context, Function *functionType);
+
 } // namespace CPlusPlus
 
 #endif // CPLUSPLUS_CPPDOCUMENT_H
diff --git a/src/libs/utils/changeset.cpp b/src/libs/utils/changeset.cpp
index 271303048d5..1433e55fafa 100644
--- a/src/libs/utils/changeset.cpp
+++ b/src/libs/utils/changeset.cpp
@@ -41,6 +41,11 @@ ChangeSet::ChangeSet()
 {
 }
 
+ChangeSet::ChangeSet(const QList<EditOp> &operations)
+    : m_string(0), m_cursor(0), m_operationList(operations), m_error(false)
+{
+}
+
 static bool overlaps(int posA, int lengthA, int posB, int lengthB) {
     if (lengthB > 0) {
         return
diff --git a/src/libs/utils/changeset.h b/src/libs/utils/changeset.h
index 5b26c703b21..d184f379ebc 100644
--- a/src/libs/utils/changeset.h
+++ b/src/libs/utils/changeset.h
@@ -81,6 +81,7 @@ public:
 
 public:
     ChangeSet();
+    ChangeSet(const QList<EditOp> &operations);
 
     bool isEmpty() const;
 
diff --git a/src/plugins/cppeditor/cppeditor.cpp b/src/plugins/cppeditor/cppeditor.cpp
index bc07e4ffbc8..c15f1e04e7c 100644
--- a/src/plugins/cppeditor/cppeditor.cpp
+++ b/src/plugins/cppeditor/cppeditor.cpp
@@ -67,6 +67,7 @@
 #include <cpptools/cppcompletionassist.h>
 #include <cpptools/cppqtstyleindenter.h>
 #include <cpptools/cppcodestylesettings.h>
+#include <cpptools/cpprefactoringchanges.h>
 
 #include <coreplugin/icore.h>
 #include <coreplugin/actionmanager/actionmanager.h>
@@ -76,6 +77,7 @@
 #include <coreplugin/editormanager/ieditor.h>
 #include <coreplugin/editormanager/editormanager.h>
 #include <coreplugin/mimedatabase.h>
+#include <utils/qtcassert.h>
 #include <utils/uncommentselection.h>
 #include <extensionsystem/pluginmanager.h>
 #include <projectexplorer/projectexplorerconstants.h>
@@ -84,6 +86,7 @@
 #include <texteditor/fontsettings.h>
 #include <texteditor/tabsettings.h>
 #include <texteditor/texteditorconstants.h>
+#include <texteditor/refactoroverlay.h>
 #include <texteditor/codeassist/basicproposalitemlistmodel.h>
 #include <texteditor/codeassist/basicproposalitem.h>
 #include <texteditor/codeassist/genericproposal.h>
@@ -111,7 +114,8 @@
 
 enum {
     UPDATE_OUTLINE_INTERVAL = 500,
-    UPDATE_USES_INTERVAL = 500
+    UPDATE_USES_INTERVAL = 500,
+    UPDATE_FUNCTION_DECL_DEF_LINK_INTERVAL = 200
 };
 
 using namespace CPlusPlus;
@@ -464,6 +468,13 @@ CPPEditorWidget::CPPEditorWidget(QWidget *parent)
     m_referencesRevision = 0;
     m_referencesCursorPosition = 0;
     connect(&m_referencesWatcher, SIGNAL(finished()), SLOT(markSymbolsNow()));
+
+    connect(this, SIGNAL(refactorMarkerClicked(TextEditor::RefactorMarker)),
+            this, SLOT(onRefactorMarkerClicked(TextEditor::RefactorMarker)));
+
+    m_declDefLinkFinder = new FunctionDeclDefLinkFinder(this);
+    connect(m_declDefLinkFinder, SIGNAL(foundLink(QSharedPointer<FunctionDeclDefLink>)),
+            this, SLOT(onFunctionDeclDefLinkFound(QSharedPointer<FunctionDeclDefLink>)));
 }
 
 CPPEditorWidget::~CPPEditorWidget()
@@ -533,6 +544,11 @@ void CPPEditorWidget::createToolBar(CPPEditor *editor)
     m_updateUsesTimer->setInterval(UPDATE_USES_INTERVAL);
     connect(m_updateUsesTimer, SIGNAL(timeout()), this, SLOT(updateUsesNow()));
 
+    m_updateFunctionDeclDefLinkTimer = new QTimer(this);
+    m_updateFunctionDeclDefLinkTimer->setSingleShot(true);
+    m_updateFunctionDeclDefLinkTimer->setInterval(UPDATE_FUNCTION_DECL_DEF_LINK_INTERVAL);
+    connect(m_updateFunctionDeclDefLinkTimer, SIGNAL(timeout()), this, SLOT(updateFunctionDeclDefLinkNow()));
+
     connect(m_outlineCombo, SIGNAL(activated(int)), this, SLOT(jumpToOutlineElement(int)));
     connect(this, SIGNAL(cursorPositionChanged()), this, SLOT(updateOutlineIndex()));
     connect(m_outlineCombo, SIGNAL(currentIndexChanged(int)), this, SLOT(updateOutlineToolTip()));
@@ -540,6 +556,9 @@ void CPPEditorWidget::createToolBar(CPPEditor *editor)
 
     connect(file(), SIGNAL(changed()), this, SLOT(updateFileName()));
 
+    // set up function declaration - definition link
+    connect(this, SIGNAL(cursorPositionChanged()), this, SLOT(updateFunctionDeclDefLink()));
+    connect(this, SIGNAL(textChanged()), this, SLOT(updateFunctionDeclDefLink()));
 
     // set up the semantic highlighter
     connect(this, SIGNAL(cursorPositionChanged()), this, SLOT(updateUses()));
@@ -1170,77 +1189,6 @@ static inline LookupItem skipForwardDeclarations(const QList<LookupItem> &resolv
     return result;
 }
 
-namespace {
-
-QList<Declaration *> findMatchingDeclaration(const LookupContext &context,
-                                             Function *functionType)
-{
-    QList<Declaration *> result;
-
-    Scope *enclosingScope = functionType->enclosingScope();
-    while (! (enclosingScope->isNamespace() || enclosingScope->isClass()))
-        enclosingScope = enclosingScope->enclosingScope();
-    Q_ASSERT(enclosingScope != 0);
-
-    const Name *functionName = functionType->name();
-    if (! functionName)
-        return result; // anonymous function names are not valid c++
-
-    ClassOrNamespace *binding = 0;
-    const QualifiedNameId *qName = functionName->asQualifiedNameId();
-    if (qName) {
-        if (qName->base())
-            binding = context.lookupType(qName->base(), enclosingScope);
-        functionName = qName->name();
-    }
-
-    if (!binding) { // declaration for a global function
-        binding = context.lookupType(enclosingScope);
-
-        if (!binding)
-            return result;
-    }
-
-    const Identifier *funcId = functionName->identifier();
-    if (!funcId) // E.g. operator, which we might be able to handle in the future...
-        return result;
-
-    QList<Declaration *> good, better, best;
-
-    foreach (Symbol *s, binding->symbols()) {
-        Class *matchingClass = s->asClass();
-        if (!matchingClass)
-            continue;
-
-        for (Symbol *s = matchingClass->find(funcId); s; s = s->next()) {
-            if (! s->name())
-                continue;
-            else if (! funcId->isEqualTo(s->identifier()))
-                continue;
-            else if (! s->type()->isFunctionType())
-                continue;
-            else if (Declaration *decl = s->asDeclaration()) {
-                if (Function *declFunTy = decl->type()->asFunctionType()) {
-                    if (functionType->isEqualTo(declFunTy))
-                        best.prepend(decl);
-                    else if (functionType->argumentCount() == declFunTy->argumentCount() && result.isEmpty())
-                        better.prepend(decl);
-                    else
-                        good.append(decl);
-                }
-            }
-        }
-    }
-
-    result.append(best);
-    result.append(better);
-    result.append(good);
-
-    return result;
-}
-
-} // end of anonymous namespace
-
 CPPEditorWidget::Link CPPEditorWidget::attemptFuncDeclDef(const QTextCursor &cursor, const Document::Ptr &doc, Snapshot snapshot) const
 {
     snapshot.insert(doc);
@@ -1616,7 +1564,10 @@ bool CPPEditorWidget::event(QEvent *e)
 {
     switch (e->type()) {
     case QEvent::ShortcutOverride:
-        if (static_cast<QKeyEvent*>(e)->key() == Qt::Key_Escape && m_currentRenameSelection != NoCurrentRenameSelection) {
+        // handle escape manually if a rename or func decl/def link is active
+        if (static_cast<QKeyEvent*>(e)->key() == Qt::Key_Escape
+                && (m_currentRenameSelection != NoCurrentRenameSelection
+                    || m_declDefLink)) {
             e->accept();
             return true;
         }
@@ -1691,10 +1642,29 @@ void CPPEditorWidget::contextMenuEvent(QContextMenuEvent *e)
 void CPPEditorWidget::keyPressEvent(QKeyEvent *e)
 {
     if (m_currentRenameSelection == NoCurrentRenameSelection) {
+        // key handling for linked function declarations/definitions
+        if (m_declDefLink && m_declDefLink->isMarkerVisible()) {
+            switch (e->key()) {
+            case Qt::Key_Enter:
+            case Qt::Key_Return:
+                applyDeclDefLinkChanges(/*jump tp change*/ e->modifiers() & Qt::ShiftModifier);
+                e->accept();
+                return;
+            case Qt::Key_Escape:
+                abortDeclDefLink();
+                e->accept();
+                return;
+            default:
+                break;
+            }
+        }
+
         TextEditor::BaseTextEditorWidget::keyPressEvent(e);
         return;
     }
 
+    // key handling for renames
+
     QTextCursor cursor = textCursor();
     const QTextCursor::MoveMode moveMode =
             (e->modifiers() & Qt::ShiftModifier) ? QTextCursor::KeepAnchor : QTextCursor::MoveAnchor;
@@ -1974,6 +1944,9 @@ void CPPEditorWidget::updateSemanticInfo(const SemanticInfo &semanticInfo)
     }
 
     m_lastSemanticInfo.forced = false; // clear the forced flag
+
+    // schedule a check for a decl/def link
+    updateFunctionDeclDefLink();
 }
 
 namespace {
@@ -2274,4 +2247,78 @@ TextEditor::IAssistInterface *CPPEditorWidget::createAssistInterface(
     return 0;
 }
 
+void CPPEditorWidget::onRefactorMarkerClicked(const TextEditor::RefactorMarker &marker)
+{
+    if (marker.data.canConvert<FunctionDeclDefLink::Marker>())
+        applyDeclDefLinkChanges(true);
+}
+
+void CPPEditorWidget::updateFunctionDeclDefLink()
+{
+    const int pos = textCursor().selectionStart();
+
+    // if there's already a link, abort it if the cursor is outside
+    if (m_declDefLink
+            && (pos < m_declDefLink->linkSelection.selectionStart()
+                || pos > m_declDefLink->linkSelection.selectionEnd())) {
+        abortDeclDefLink();
+        return;
+    }
+
+    // don't start a new scan if there's one active and the cursor is already in the scanned area
+    const QTextCursor scannedSelection = m_declDefLinkFinder->scannedSelection();
+    if (!scannedSelection.isNull()
+            && scannedSelection.selectionStart() <= pos
+            && scannedSelection.selectionEnd() >= pos) {
+        return;
+    }
+
+    m_updateFunctionDeclDefLinkTimer->start();
+}
+
+void CPPEditorWidget::updateFunctionDeclDefLinkNow()
+{
+    if (Core::EditorManager::instance()->currentEditor() != editor())
+        return;
+    if (m_declDefLink) {
+        // update the change marker
+        const Utils::ChangeSet changes = m_declDefLink->changes(m_lastSemanticInfo.snapshot);
+        if (changes.isEmpty())
+            m_declDefLink->hideMarker(this);
+        else
+            m_declDefLink->showMarker(this);
+        return;
+    }
+    if (!m_lastSemanticInfo.doc || isOutdated())
+        return;
+
+    Snapshot snapshot = CppModelManagerInterface::instance()->snapshot();
+    snapshot.insert(m_lastSemanticInfo.doc);
+
+    m_declDefLinkFinder->startFindLinkAt(textCursor(), m_lastSemanticInfo.doc, snapshot);
+}
+
+void CPPEditorWidget::onFunctionDeclDefLinkFound(QSharedPointer<FunctionDeclDefLink> link)
+{
+    abortDeclDefLink();
+    m_declDefLink = link;
+}
+
+void CPPEditorWidget::applyDeclDefLinkChanges(bool jumpToMatch)
+{
+    if (!m_declDefLink)
+        return;
+    m_declDefLink->apply(this, jumpToMatch);
+    m_declDefLink.clear();
+    updateFunctionDeclDefLink();
+}
+
+void CPPEditorWidget::abortDeclDefLink()
+{
+    if (!m_declDefLink)
+        return;
+    m_declDefLink->hideMarker(this);
+    m_declDefLink.clear();
+}
+
 #include "cppeditor.moc"
diff --git a/src/plugins/cppeditor/cppeditor.h b/src/plugins/cppeditor/cppeditor.h
index a90026fcf40..d07e53d99fd 100644
--- a/src/plugins/cppeditor/cppeditor.h
+++ b/src/plugins/cppeditor/cppeditor.h
@@ -35,6 +35,7 @@
 
 #include "cppeditorenums.h"
 #include "cppsemanticinfo.h"
+#include "cppfunctiondecldeflink.h"
 
 #include <cplusplus/ModelManagerInterface.h>
 #include <cplusplus/CppDocument.h>
@@ -62,6 +63,7 @@ class Symbol;
 namespace CppTools {
 class CppModelManagerInterface;
 class CppCodeStyleSettings;
+class CppRefactoringFile;
 }
 
 namespace TextEditor {
@@ -211,7 +213,7 @@ public Q_SLOTS:
 protected:
     bool event(QEvent *e);
     void contextMenuEvent(QContextMenuEvent *);
-    void keyPressEvent(QKeyEvent *);
+    void keyPressEvent(QKeyEvent *e);
 
     TextEditor::BaseTextEditor *createEditor();
 
@@ -229,6 +231,9 @@ private Q_SLOTS:
     void updateOutlineToolTip();
     void updateUses();
     void updateUsesNow();
+    void updateFunctionDeclDefLink();
+    void updateFunctionDeclDefLinkNow();
+    void onFunctionDeclDefLinkFound(QSharedPointer<FunctionDeclDefLink> link);
     void onDocumentUpdated(CPlusPlus::Document::Ptr doc);
     void onContentsChanged(int position, int charsRemoved, int charsAdded);
 
@@ -241,6 +246,8 @@ private Q_SLOTS:
 
     void performQuickFix(int index);
 
+    void onRefactorMarkerClicked(const TextEditor::RefactorMarker &marker);
+
 private:
     void markSymbols(const QTextCursor &tc, const SemanticInfo &info);
     bool sortedOutline() const;
@@ -261,6 +268,9 @@ private:
     void finishRename();
     void abortRename();
 
+    void applyDeclDefLinkChanges(bool jumpToMatch);
+    void abortDeclDefLink();
+
     Link attemptFuncDeclDef(const QTextCursor &cursor,
                             const CPlusPlus::Document::Ptr &doc,
                             CPlusPlus::Snapshot snapshot) const;
@@ -283,6 +293,7 @@ private:
     QTimer *m_updateOutlineTimer;
     QTimer *m_updateOutlineIndexTimer;
     QTimer *m_updateUsesTimer;
+    QTimer *m_updateFunctionDeclDefLinkTimer;
     QTextCharFormat m_occurrencesFormat;
     QTextCharFormat m_occurrencesUnusedFormat;
     QTextCharFormat m_occurrenceRenameFormat;
@@ -315,6 +326,9 @@ private:
     QFutureWatcher<QList<int> > m_referencesWatcher;
     unsigned m_referencesRevision;
     int m_referencesCursorPosition;
+
+    FunctionDeclDefLinkFinder *m_declDefLinkFinder;
+    QSharedPointer<FunctionDeclDefLink> m_declDefLink;
 };
 
 
diff --git a/src/plugins/cppeditor/cppeditor.pro b/src/plugins/cppeditor/cppeditor.pro
index 48e114ab826..d90fc0a0523 100644
--- a/src/plugins/cppeditor/cppeditor.pro
+++ b/src/plugins/cppeditor/cppeditor.pro
@@ -26,7 +26,8 @@ HEADERS += cppplugin.h \
     cppsnippetprovider.h \
     cppinsertqtpropertymembers.h \
     cppquickfixassistant.h \
-    cppquickfix.h
+    cppquickfix.h \
+    cppfunctiondecldeflink.h
 
 SOURCES += cppplugin.cpp \
     cppeditor.cpp \
@@ -47,7 +48,10 @@ SOURCES += cppplugin.cpp \
     cppsnippetprovider.cpp \
     cppinsertqtpropertymembers.cpp \
     cppquickfixassistant.cpp \
-    cppquickfix.cpp
+    cppquickfix.cpp \
+    cppfunctiondecldeflink.cpp
 
 RESOURCES += cppeditor.qrc
 OTHER_FILES += CppEditor.mimetypes.xml
+
+
diff --git a/src/plugins/cppeditor/cppfunctiondecldeflink.cpp b/src/plugins/cppeditor/cppfunctiondecldeflink.cpp
new file mode 100644
index 00000000000..3c439160542
--- /dev/null
+++ b/src/plugins/cppeditor/cppfunctiondecldeflink.cpp
@@ -0,0 +1,569 @@
+/**************************************************************************
+**
+** This file is part of Qt Creator
+**
+** Copyright (c) 2011 Nokia Corporation and/or its subsidiary(-ies).
+**
+** Contact: Nokia Corporation (info@qt.nokia.com)
+**
+**
+** GNU Lesser General Public License Usage
+**
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this file.
+** Please review the following information to ensure the GNU Lesser General
+** Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** Other Usage
+**
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at info@qt.nokia.com.
+**
+**************************************************************************/
+
+#include "cppfunctiondecldeflink.h"
+
+#include "cppeditor.h"
+
+#include <cplusplus/CppRewriter.h>
+#include <cplusplus/ASTPath.h>
+#include <cplusplus/AST.h>
+#include <cplusplus/Symbols.h>
+#include <cplusplus/TypeOfExpression.h>
+#include <cplusplus/TranslationUnit.h>
+#include <cplusplus/LookupContext.h>
+#include <cplusplus/Overview.h>
+#include <texteditor/refactoroverlay.h>
+#include <texteditor/tooltip/tooltip.h>
+#include <texteditor/tooltip/tipcontents.h>
+#include <utils/qtcassert.h>
+
+#include <QtCore/QtConcurrentRun>
+
+using namespace CPlusPlus;
+using namespace CppEditor;
+using namespace CppEditor::Internal;
+
+FunctionDeclDefLinkFinder::FunctionDeclDefLinkFinder(QObject *parent)
+    : QObject(parent)
+{
+    connect(&m_watcher, SIGNAL(finished()),
+            this, SLOT(onFutureDone()));
+}
+
+void FunctionDeclDefLinkFinder::onFutureDone()
+{
+    QSharedPointer<FunctionDeclDefLink> link = m_watcher.result();
+    if (link)
+        link->linkSelection = m_scannedSelection;
+    m_scannedSelection = QTextCursor();
+    if (link)
+        emit foundLink(link);
+}
+
+QTextCursor FunctionDeclDefLinkFinder::scannedSelection() const
+{
+    return m_scannedSelection;
+}
+
+// parent is either a FunctionDefinitionAST or a SimpleDeclarationAST
+static bool findDeclOrDef(const Document::Ptr &doc, const QTextCursor &cursor,
+                          DeclarationAST **parent, FunctionDeclaratorAST **funcDecl)
+{
+    QList<AST *> path = ASTPath(doc)(cursor);
+
+    // for function definitions, simply scan for FunctionDefinitionAST not preceded
+    //    by CompoundStatement/CtorInitializer
+    // for function declarations, look for SimpleDeclarations with a single Declarator
+    //    with a FunctionDeclarator postfix
+    FunctionDefinitionAST *funcDef = 0;
+    SimpleDeclarationAST *simpleDecl = 0;
+    DeclaratorAST *decl = 0;
+    for (int i = path.size() - 1; i > 0; --i) {
+        AST *ast = path.at(i);
+        if (ast->asCompoundStatement() || ast->asCtorInitializer())
+            break;
+        if ((funcDef = ast->asFunctionDefinition()) != 0) {
+            *parent = funcDef;
+            decl = funcDef->declarator;
+            break;
+        }
+        if ((simpleDecl = ast->asSimpleDeclaration()) != 0) {
+            *parent = simpleDecl;
+            if (!simpleDecl->declarator_list || !simpleDecl->declarator_list->value)
+                break;
+            decl = simpleDecl->declarator_list->value;
+            break;
+        }
+    }
+    if (!*parent || !decl)
+        return false;
+    if (!decl->postfix_declarator_list || !decl->postfix_declarator_list->value)
+        return false;
+    *funcDecl = decl->postfix_declarator_list->value->asFunctionDeclarator();
+    return *funcDecl;
+}
+
+static void declDefLinkStartEnd(const CppTools::CppRefactoringFile &file,
+                                DeclarationAST *parent, FunctionDeclaratorAST *funcDecl,
+                                int *start, int *end)
+{
+    *start = file.startOf(parent);
+    if (funcDecl->trailing_return_type)
+        *end = file.endOf(funcDecl->trailing_return_type);
+    else if (funcDecl->exception_specification)
+        *end = file.endOf(funcDecl->exception_specification);
+    else if (funcDecl->cv_qualifier_list)
+        *end = file.endOf(funcDecl->cv_qualifier_list->lastValue());
+    else
+        *end = file.endOf(funcDecl->rparen_token);
+}
+
+static QSharedPointer<FunctionDeclDefLink> findLinkHelper(QSharedPointer<FunctionDeclDefLink> link, CppTools::CppRefactoringChanges changes)
+{
+    QSharedPointer<FunctionDeclDefLink> noResult;
+    const Snapshot &snapshot = changes.snapshot();
+
+    // find the matching decl/def symbol
+    Symbol *target = 0;
+    if (FunctionDefinitionAST *funcDef = link->sourceDeclaration->asFunctionDefinition()) {
+        QList<Declaration *> nameMatch, argumentCountMatch, typeMatch;
+        findMatchingDeclaration(LookupContext(link->sourceDocument, snapshot),
+                                funcDef->symbol,
+                                &typeMatch, &argumentCountMatch, &nameMatch);
+        if (!typeMatch.isEmpty())
+            target = typeMatch.first();
+    } else if (link->sourceDeclaration->asSimpleDeclaration()) {
+        target = snapshot.findMatchingDefinition(link->sourceFunctionDeclarator->symbol, true);
+    }
+    if (!target) {
+        return noResult;
+    }
+
+    // parse the target file to get the linked decl/def
+    const QString targetFileName = QString::fromUtf8(
+                target->fileName(), target->fileNameLength());
+    CppTools::CppRefactoringFile targetFile = changes.file(targetFileName);
+    if (!targetFile.isValid())
+        return noResult;
+
+    QTextCursor tc(targetFile.cursor());
+    tc.setPosition(targetFile.position(target->line(), target->column()));
+    DeclarationAST *targetParent = 0;
+    FunctionDeclaratorAST *targetFuncDecl = 0;
+    if (!findDeclOrDef(targetFile.cppDocument(), tc, &targetParent, &targetFuncDecl))
+        return noResult;
+
+    // the parens are necessary for finding good places for changes
+    if (!targetFuncDecl->lparen_token || !targetFuncDecl->rparen_token)
+        return noResult;
+
+    int targetStart, targetEnd;
+    declDefLinkStartEnd(targetFile, targetParent, targetFuncDecl, &targetStart, &targetEnd);
+    QString targetInitial = targetFile.textOf(
+                targetFile.startOf(targetParent),
+                targetEnd);
+
+    link->targetOffset = targetStart;
+    link->targetInitial = targetInitial;
+
+    link->targetFile = QSharedPointer<CppTools::CppRefactoringFile>(
+                new CppTools::CppRefactoringFile(targetFile.document()->clone(), targetFile.fileName()));
+    link->targetFile->setCppDocument(targetFile.cppDocument());
+    link->targetFunction = targetFuncDecl->symbol;
+    link->targetFunctionDeclarator = targetFuncDecl;
+    link->targetDeclaration = targetParent;
+
+    return link;
+}
+
+void FunctionDeclDefLinkFinder::startFindLinkAt(
+        QTextCursor cursor, const Document::Ptr &doc, const Snapshot &snapshot)
+{
+    // check if cursor is on function decl/def
+    DeclarationAST *parent = 0;
+    FunctionDeclaratorAST *funcDecl = 0;
+    if (!findDeclOrDef(doc, cursor, &parent, &funcDecl))
+        return;
+
+    // find the start/end offsets
+    CppTools::CppRefactoringChanges refactoringChanges(snapshot);
+    CppTools::CppRefactoringFile sourceFile = refactoringChanges.file(doc->fileName());
+    sourceFile.setCppDocument(doc);
+    int start, end;
+    declDefLinkStartEnd(sourceFile, parent, funcDecl, &start, &end);
+
+    // if already scanning, don't scan again
+    if (!m_scannedSelection.isNull()
+            && m_scannedSelection.selectionStart() == start
+            && m_scannedSelection.selectionEnd() == end) {
+        return;
+    }
+
+    // build the selection for the currently scanned area
+    m_scannedSelection = cursor;
+    m_scannedSelection.setPosition(end);
+    m_scannedSelection.setPosition(start, QTextCursor::KeepAnchor);
+    m_scannedSelection.setKeepPositionOnInsert(true);
+
+    // set up a base result
+    QSharedPointer<FunctionDeclDefLink> result(new FunctionDeclDefLink);
+    result->sourceDocument = doc;
+    result->sourceFunction = funcDecl->symbol;
+    result->sourceDeclaration = parent;
+    result->sourceFunctionDeclarator = funcDecl;
+
+    // handle the rest in a thread
+    m_watcher.setFuture(QtConcurrent::run(&findLinkHelper, result, refactoringChanges));
+}
+
+FunctionDeclDefLink::FunctionDeclDefLink()
+{
+    hasMarker = false;
+    targetOffset = 0;
+    sourceFunction = 0;
+    targetFunction = 0;
+    targetDeclaration = 0;
+    targetFunctionDeclarator = 0;
+}
+
+FunctionDeclDefLink::~FunctionDeclDefLink()
+{
+}
+
+bool FunctionDeclDefLink::isValid() const
+{
+    return targetFile;
+}
+
+bool FunctionDeclDefLink::isMarkerVisible() const
+{
+    return hasMarker;
+}
+
+static bool namesEqual(const Name *n1, const Name *n2)
+{
+    return n1 == n2 || (n1 && n2 && n1->isEqualTo(n2));
+}
+
+static DeclaratorIdAST *getDeclaratorId(DeclaratorAST *declarator)
+{
+    if (!declarator || !declarator->core_declarator)
+        return 0;
+    if (DeclaratorIdAST *id = declarator->core_declarator->asDeclaratorId()) {
+        return id;
+    }
+    if (NestedDeclaratorAST *nested = declarator->core_declarator->asNestedDeclarator()) {
+        return getDeclaratorId(nested->declarator);
+    }
+    return 0;
+}
+
+void FunctionDeclDefLink::apply(CPPEditorWidget *editor, bool jumpToMatch)
+{
+    Snapshot snapshot = editor->semanticInfo().snapshot;
+
+    // first verify the interesting region of the target file is unchanged
+    CppTools::CppRefactoringChanges refactoringChanges(snapshot);
+    CppTools::CppRefactoringFile newTargetFile = refactoringChanges.file(targetFile->fileName());
+    if (!newTargetFile.isValid())
+        return;
+    const int targetEnd = targetOffset + targetInitial.size();
+    if (targetInitial == newTargetFile.textOf(targetOffset, targetEnd)) {
+        const Utils::ChangeSet changeset = changes(snapshot);
+        newTargetFile.change(changeset, jumpToMatch);
+        if (jumpToMatch) {
+            QTextCursor tc = newTargetFile.cursor();
+            tc.setPosition(targetOffset + targetInitial.size());
+            refactoringChanges.activateEditor(newTargetFile.fileName(), tc.blockNumber(), tc.columnNumber());
+        }
+    } else {
+        TextEditor::ToolTip::instance()->show(
+                    editor->toolTipPosition(linkSelection),
+                    TextEditor::TextContent(
+                        tr("Target file was changed, could not apply changes")));
+    }
+
+    hideMarker(editor);
+}
+
+template <class T>
+static QList<TextEditor::RefactorMarker> removeMarkersOfType(const QList<TextEditor::RefactorMarker> &markers)
+{
+    QList<TextEditor::RefactorMarker> result;
+    foreach (const TextEditor::RefactorMarker &marker, markers) {
+        if (!marker.data.canConvert<T>())
+            result += marker;
+    }
+    return result;
+}
+
+void FunctionDeclDefLink::hideMarker(CPPEditorWidget *editor)
+{
+    if (!hasMarker)
+        return;
+    editor->setRefactorMarkers(
+                removeMarkersOfType<Marker>(editor->refactorMarkers()));
+    hasMarker = false;
+}
+
+void FunctionDeclDefLink::showMarker(CPPEditorWidget *editor)
+{
+    if (hasMarker)
+        return;
+
+    QList<TextEditor::RefactorMarker> markers = removeMarkersOfType<Marker>(editor->refactorMarkers());
+    TextEditor::RefactorMarker marker;
+
+    // show the marker at the end of the linked area, with a special case
+    // to avoid it overlapping with a trailing semicolon
+    marker.cursor = editor->textCursor();
+    marker.cursor.setPosition(linkSelection.selectionEnd());
+    const int endBlockNr = marker.cursor.blockNumber();
+    marker.cursor.setPosition(linkSelection.selectionEnd() + 1, QTextCursor::KeepAnchor);
+    if (marker.cursor.blockNumber() != endBlockNr
+            || marker.cursor.selectedText() != QLatin1String(";")) {
+        marker.cursor.setPosition(linkSelection.selectionEnd());
+    }
+
+    QString message;
+    if (targetDeclaration->asFunctionDefinition())
+        message = tr("Apply changes to definition");
+    else
+        message = tr("Apply changes to declaration");
+    marker.tooltip = message;
+    marker.data = QVariant::fromValue(Marker());
+    markers += marker;
+    editor->setRefactorMarkers(markers);
+
+    hasMarker = true;
+}
+
+Utils::ChangeSet FunctionDeclDefLink::changes(const Snapshot &snapshot)
+{
+    Utils::ChangeSet changes;
+
+    QSharedPointer<CppTools::CppRefactoringFile> matchFile = targetFile;
+
+    // parse the current source declaration
+    TypeOfExpression typeOfExpression; // ### just need to preprocess...
+    typeOfExpression.init(sourceDocument, snapshot);
+    const QString newDecl = typeOfExpression.preprocess(
+                linkSelection.selectedText()) + QLatin1String("{}");
+    Document::Ptr newDeclDoc = Document::create(QLatin1String("<decl>"));
+    newDeclDoc->setSource(newDecl.toUtf8());
+    newDeclDoc->parse(Document::ParseDeclaration);
+    newDeclDoc->check();
+
+    // extract the function symbol
+    if (!newDeclDoc->translationUnit()->ast()) {
+        return changes;
+    }
+    FunctionDefinitionAST *newDef = newDeclDoc->translationUnit()->ast()->asFunctionDefinition();
+    if (!newDef) {
+        return changes;
+    }
+    Function *newFunction = newDef->symbol;
+    QTC_ASSERT(newFunction, return changes); // check() should always create this symbol
+
+    LookupContext sourceContext(sourceDocument, snapshot);
+    LookupContext targetContext(targetFile->cppDocument(), snapshot);
+
+    Overview overview;
+    overview.setShowReturnTypes(true);
+    overview.setShowTemplateParameters(true);
+    overview.setShowArgumentNames(true);
+    overview.setShowFunctionSignatures(true);
+
+    // sync return type
+    {
+        // set up for rewriting return type
+        SubstitutionEnvironment env;
+        env.setContext(sourceContext);
+        env.switchScope(sourceFunction->enclosingScope());
+        ClassOrNamespace *targetCoN = targetContext.lookupType(targetFunction->enclosingScope());
+        if (!targetCoN)
+            targetCoN = targetContext.globalNamespace();
+        UseMinimalNames q(targetCoN);
+        env.enter(&q);
+        Control *control = sourceContext.control().data();
+
+        // get return type start position and declarator info from declaration
+        int returnTypeStart = 0;
+        DeclaratorAST *declarator = 0;
+        if (SimpleDeclarationAST *simple = targetDeclaration->asSimpleDeclaration()) {
+            declarator = simple->declarator_list->value;
+            if (simple->decl_specifier_list)
+                returnTypeStart = matchFile->startOf(simple->decl_specifier_list->value);
+            else
+                returnTypeStart = matchFile->startOf(declarator);
+        } else if (FunctionDefinitionAST *def = targetDeclaration->asFunctionDefinition()) {
+            declarator = def->declarator;
+            if (def->decl_specifier_list)
+                returnTypeStart = matchFile->startOf(def->decl_specifier_list->value);
+            else
+                returnTypeStart = matchFile->startOf(declarator);
+        }
+
+        if (!newFunction->returnType().isEqualTo(sourceFunction->returnType())
+                && !newFunction->returnType().isEqualTo(targetFunction->returnType())) {
+            FullySpecifiedType type = rewriteType(newFunction->returnType(), &env, control);
+            const QString replacement = overview(type, targetFunction->name());
+            changes.replace(returnTypeStart,
+                            matchFile->startOf(targetFunctionDeclarator->lparen_token),
+                            replacement);
+        }
+    }
+
+    // sync parameters
+    {
+        // set up for rewriting parameter types
+        SubstitutionEnvironment env;
+        env.setContext(sourceContext);
+        env.switchScope(sourceFunction);
+        ClassOrNamespace *targetCoN = targetContext.lookupType(targetFunction);
+        if (!targetCoN)
+            targetCoN = targetContext.globalNamespace();
+        UseMinimalNames q(targetCoN);
+        env.enter(&q);
+        Control *control = sourceContext.control().data();
+        Overview overview;
+
+        // check if parameter types or names have changed
+        const unsigned existingArgs = qMin(targetFunction->argumentCount(), newFunction->argumentCount());
+        ParameterDeclarationClauseAST *targetParameterDecl =
+                targetFunctionDeclarator->parameter_declaration_clause;
+        ParameterDeclarationListAST *firstTargetParameterDeclIt =
+                targetParameterDecl ? targetParameterDecl->parameter_declaration_list : 0;
+        ParameterDeclarationListAST *targetParameterDeclIt = firstTargetParameterDeclIt;
+        for (unsigned i = 0;
+             i < existingArgs && targetParameterDeclIt;
+             ++i, targetParameterDeclIt = targetParameterDeclIt->next) {
+            Symbol *targetParam = targetFunction->argumentAt(i);
+            Symbol *newParam = newFunction->argumentAt(i);
+
+            // if new's name and type are the same as source's, forbid changes
+            bool allowChangeType = true;
+            const Name *replacementName = newParam->name();
+            if (i < sourceFunction->argumentCount()) {
+                Symbol *sourceParam = sourceFunction->argumentAt(i);
+                if (newParam->type().isEqualTo(sourceParam->type()))
+                    allowChangeType = false;
+                if (namesEqual(replacementName, sourceParam->name()))
+                    replacementName = targetParam->name();
+            }
+
+            ParameterDeclarationAST *targetParamAst = targetParameterDeclIt->value;
+            int parameterNameEnd = 0;
+            if (targetParamAst->declarator)
+                parameterNameEnd = matchFile->endOf(targetParamAst->declarator);
+            else if (targetParamAst->type_specifier_list)
+                parameterNameEnd = matchFile->endOf(targetParamAst->type_specifier_list->lastToken() - 1);
+            else
+                parameterNameEnd = matchFile->startOf(targetParamAst);
+
+            if (allowChangeType
+                    && !targetParam->type().isEqualTo(newParam->type())) {
+                FullySpecifiedType replacementType = rewriteType(newParam->type(), &env, control);
+                const QString replacement = overview(replacementType, replacementName);
+
+                changes.replace(matchFile->startOf(targetParamAst),
+                                parameterNameEnd,
+                                replacement);
+            } else if (!namesEqual(targetParam->name(), replacementName)) {
+                DeclaratorIdAST *id = getDeclaratorId(targetParamAst->declarator);
+                QString replacementNameStr = overview(replacementName);
+                if (id) {
+                    changes.replace(matchFile->range(id), replacementNameStr);
+                } else {
+                    // add name to unnamed parameter
+                    replacementNameStr.prepend(QLatin1Char(' '));
+                    int end;
+                    if (targetParamAst->equal_token) {
+                        end = matchFile->startOf(targetParamAst->equal_token);
+                        replacementNameStr.append(QLatin1Char(' '));
+                    } else {
+                        // one past end on purpose
+                        end = matchFile->startOf(targetParamAst->lastToken());
+                    }
+                    changes.replace(parameterNameEnd, end, replacementNameStr);
+                }
+            }
+        }
+        if (newFunction->argumentCount() < targetFunction->argumentCount()) {
+            targetParameterDeclIt = firstTargetParameterDeclIt;
+            if (targetParameterDeclIt) {
+                if (newFunction->argumentCount() == 0) {
+                    changes.remove(matchFile->startOf(targetParameterDeclIt->firstToken()),
+                                   matchFile->endOf(targetParameterDeclIt->lastToken() - 1));
+                } else {
+                    // get the last valid argument
+                    for (unsigned i = 0; i < newFunction->argumentCount() - 1 && targetParameterDeclIt; ++i)
+                        targetParameterDeclIt = targetParameterDeclIt->next;
+                    if (targetParameterDeclIt) {
+                        const int start = matchFile->endOf(targetParameterDeclIt->value);
+                        const int end = matchFile->endOf(targetParameterDecl->lastToken() - 1);
+                        changes.remove(start, end);
+                    }
+                }
+            }
+        } else if (newFunction->argumentCount() > targetFunction->argumentCount()) {
+            QString newParams;
+            for (unsigned i = targetFunction->argumentCount(); i < newFunction->argumentCount(); ++i) {
+                Symbol *param = newFunction->argumentAt(i);
+                FullySpecifiedType type = rewriteType(param->type(), &env, control);
+                if (i != 0)
+                    newParams += QLatin1String(", ");
+                newParams += overview(type, param->name());
+            }
+            targetParameterDeclIt = firstTargetParameterDeclIt;
+            if (targetParameterDeclIt) {
+                while (targetParameterDeclIt->next)
+                    targetParameterDeclIt = targetParameterDeclIt->next;
+                changes.insert(matchFile->endOf(targetParameterDeclIt->value), newParams);
+            } else {
+                changes.insert(matchFile->endOf(targetFunctionDeclarator->lparen_token), newParams);
+            }
+        }
+    }
+
+    // sync cv qualification
+    if (targetFunction->isConst() != newFunction->isConst()
+            || targetFunction->isVolatile() != newFunction->isVolatile()) {
+        QString cvString;
+        if (newFunction->isConst())
+            cvString += QLatin1String("const");
+        if (newFunction->isVolatile()) {
+            if (!cvString.isEmpty())
+                cvString += QLatin1Char(' ');
+            cvString += QLatin1String("volatile");
+        }
+        const int rparenEnd = matchFile->endOf(targetFunctionDeclarator->rparen_token);
+        if (targetFunctionDeclarator->cv_qualifier_list) {
+            const int cvEnd = matchFile->endOf(targetFunctionDeclarator->cv_qualifier_list->lastToken() - 1);
+            // if the qualifies changed, replace
+            if (!cvString.isEmpty()) {
+                changes.replace(matchFile->startOf(targetFunctionDeclarator->cv_qualifier_list->firstToken()),
+                                cvEnd, cvString);
+            } else {
+                // remove
+                changes.remove(rparenEnd, cvEnd);
+            }
+        } else {
+            // otherwise add
+            cvString.prepend(QLatin1Char(' '));
+            changes.insert(rparenEnd, cvString);
+        }
+    }
+
+    return changes;
+}
diff --git a/src/plugins/cppeditor/cppfunctiondecldeflink.h b/src/plugins/cppeditor/cppfunctiondecldeflink.h
new file mode 100644
index 00000000000..5de47afb918
--- /dev/null
+++ b/src/plugins/cppeditor/cppfunctiondecldeflink.h
@@ -0,0 +1,121 @@
+/**************************************************************************
+**
+** This file is part of Qt Creator
+**
+** Copyright (c) 2011 Nokia Corporation and/or its subsidiary(-ies).
+**
+** Contact: Nokia Corporation (info@qt.nokia.com)
+**
+**
+** GNU Lesser General Public License Usage
+**
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this file.
+** Please review the following information to ensure the GNU Lesser General
+** Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** Other Usage
+**
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at info@qt.nokia.com.
+**
+**************************************************************************/
+
+#ifndef CPPFUNCTIONDECLDEFLINK_H
+#define CPPFUNCTIONDECLDEFLINK_H
+
+#include <cplusplus/CppDocument.h>
+#include <cplusplus/ASTfwd.h>
+
+#include <cpptools/cpprefactoringchanges.h>
+#include <utils/changeset.h>
+
+#include <QtCore/QString>
+#include <QtCore/QCoreApplication>
+#include <QtCore/QSharedPointer>
+#include <QtCore/QFutureWatcher>
+#include <QtGui/QTextCursor>
+
+namespace CppEditor {
+namespace Internal {
+
+class CPPEditorWidget;
+class FunctionDeclDefLink;
+
+class FunctionDeclDefLinkFinder : public QObject
+{
+    Q_OBJECT
+public:
+    FunctionDeclDefLinkFinder(QObject *parent = 0);
+
+    void startFindLinkAt(QTextCursor cursor,
+                    const CPlusPlus::Document::Ptr &doc,
+                    const CPlusPlus::Snapshot &snapshot);
+
+    QTextCursor scannedSelection() const;
+
+signals:
+    void foundLink(QSharedPointer<FunctionDeclDefLink> link);
+
+private slots:
+    void onFutureDone();
+
+private:
+    QTextCursor m_scannedSelection;
+    QFutureWatcher<QSharedPointer<FunctionDeclDefLink> > m_watcher;
+};
+
+class FunctionDeclDefLink
+{
+    Q_DECLARE_TR_FUNCTIONS(FunctionDeclDefLink)
+    Q_DISABLE_COPY(FunctionDeclDefLink)
+public:
+    ~FunctionDeclDefLink();
+
+    class Marker {};
+
+    bool isValid() const;
+    bool isMarkerVisible() const;
+
+    void apply(CPPEditorWidget *editor, bool jumpToMatch);
+    void hideMarker(CPPEditorWidget *editor);
+    void showMarker(CPPEditorWidget *editor);
+    Utils::ChangeSet changes(const CPlusPlus::Snapshot &snapshot);
+
+    QTextCursor linkSelection;
+    int targetOffset;
+    QString targetInitial;
+
+    CPlusPlus::Document::Ptr sourceDocument;
+    CPlusPlus::Function *sourceFunction;
+    CPlusPlus::DeclarationAST *sourceDeclaration;
+    CPlusPlus::FunctionDeclaratorAST *sourceFunctionDeclarator;
+
+    QSharedPointer<CppTools::CppRefactoringFile> targetFile;
+    CPlusPlus::Function *targetFunction;
+    CPlusPlus::DeclarationAST *targetDeclaration;
+    CPlusPlus::FunctionDeclaratorAST *targetFunctionDeclarator;
+
+private:
+    FunctionDeclDefLink();
+
+    bool hasMarker;
+
+    friend class FunctionDeclDefLinkFinder;
+};
+
+} // namespace Internal
+} // namespace CppEditor
+
+Q_DECLARE_METATYPE(CppEditor::Internal::FunctionDeclDefLink::Marker)
+
+#endif // CPPFUNCTIONDECLDEFLINK_H
diff --git a/src/plugins/cppeditor/cppquickfixassistant.cpp b/src/plugins/cppeditor/cppquickfixassistant.cpp
index 9b998c2db37..dccf0af8097 100644
--- a/src/plugins/cppeditor/cppquickfixassistant.cpp
+++ b/src/plugins/cppeditor/cppquickfixassistant.cpp
@@ -138,7 +138,9 @@ CPPEditorWidget *CppQuickFixAssistInterface::editor() const
 
 const CppRefactoringFile CppQuickFixAssistInterface::currentFile() const
 {
-    return CppRefactoringFile(m_editor, m_semanticInfo.doc);
+    CppRefactoringFile file(m_editor);
+    file.setCppDocument(m_semanticInfo.doc);
+    return file;
 }
 
 bool CppQuickFixAssistInterface::isCursorOn(unsigned tokenIndex) const
diff --git a/src/plugins/cpptools/cpprefactoringchanges.cpp b/src/plugins/cpptools/cpprefactoringchanges.cpp
index 53883128869..c92aa862d20 100644
--- a/src/plugins/cpptools/cpprefactoringchanges.cpp
+++ b/src/plugins/cpptools/cpprefactoringchanges.cpp
@@ -110,13 +110,13 @@ CppRefactoringFile::CppRefactoringFile(const QString &fileName, CppRefactoringCh
     m_cppDocument = snapshot.document(fileName);
 }
 
-CppRefactoringFile::CppRefactoringFile(TextEditor::BaseTextEditorWidget *editor, CPlusPlus::Document::Ptr document)
-    : RefactoringFile()
-    , m_cppDocument(document)
-{
-    m_fileName = document->fileName();
-    m_editor = editor;
-}
+CppRefactoringFile::CppRefactoringFile(QTextDocument *document, const QString &fileName)
+    : RefactoringFile(document, fileName)
+{ }
+
+CppRefactoringFile::CppRefactoringFile(TextEditor::BaseTextEditorWidget *editor)
+    : RefactoringFile(editor)
+{ }
 
 Document::Ptr CppRefactoringFile::cppDocument() const
 {
@@ -134,6 +134,11 @@ Document::Ptr CppRefactoringFile::cppDocument() const
     return m_cppDocument;
 }
 
+void CppRefactoringFile::setCppDocument(Document::Ptr document)
+{
+    m_cppDocument = document;
+}
+
 Scope *CppRefactoringFile::scopeAt(unsigned index) const
 {
     unsigned line, column;
diff --git a/src/plugins/cpptools/cpprefactoringchanges.h b/src/plugins/cpptools/cpprefactoringchanges.h
index 1e0ea6a898e..c32e4e5c99c 100644
--- a/src/plugins/cpptools/cpprefactoringchanges.h
+++ b/src/plugins/cpptools/cpprefactoringchanges.h
@@ -50,10 +50,11 @@ class CPPTOOLS_EXPORT CppRefactoringFile: public TextEditor::RefactoringFile
 {
 public:
     CppRefactoringFile();
-    CppRefactoringFile(const QString &fileName, CppRefactoringChanges *refactoringChanges);
-    CppRefactoringFile(TextEditor::BaseTextEditorWidget *editor, CPlusPlus::Document::Ptr document);
+    CppRefactoringFile(QTextDocument *document, const QString &fileName = QString());
+    CppRefactoringFile(TextEditor::BaseTextEditorWidget *editor);
 
     CPlusPlus::Document::Ptr cppDocument() const;
+    void setCppDocument(CPlusPlus::Document::Ptr document);
 
     CPlusPlus::Scope *scopeAt(unsigned index) const;
 
@@ -76,10 +77,15 @@ public:
     using TextEditor::RefactoringFile::textOf;
     QString textOf(const CPlusPlus::AST *ast) const;
 
+protected:
+    CppRefactoringFile(const QString &fileName, CppRefactoringChanges *refactoringChanges);
+
 private:
     CppRefactoringChanges *refactoringChanges() const;
 
     mutable CPlusPlus::Document::Ptr m_cppDocument;
+
+    friend class CppRefactoringChanges; // for access to constructor
 };
 
 class CPPTOOLS_EXPORT CppRefactoringChanges: public TextEditor::RefactoringChanges
diff --git a/src/plugins/texteditor/refactoringchanges.cpp b/src/plugins/texteditor/refactoringchanges.cpp
index f5b44539077..60d5fb08628 100644
--- a/src/plugins/texteditor/refactoringchanges.cpp
+++ b/src/plugins/texteditor/refactoringchanges.cpp
@@ -186,6 +186,22 @@ RefactoringFile::RefactoringFile()
     , m_openEditor(false)
 { }
 
+RefactoringFile::RefactoringFile(QTextDocument *document, const QString &fileName)
+    : m_fileName(fileName)
+    , m_refactoringChanges(0)
+    , m_document(document)
+    , m_editor(0)
+    , m_openEditor(false)
+{ }
+
+RefactoringFile::RefactoringFile(BaseTextEditorWidget *editor)
+    : m_fileName(editor->file()->fileName())
+    , m_refactoringChanges(0)
+    , m_document(0)
+    , m_editor(editor)
+    , m_openEditor(false)
+{ }
+
 RefactoringFile::RefactoringFile(const QString &fileName, RefactoringChanges *refactoringChanges)
     : m_fileName(fileName)
     , m_refactoringChanges(refactoringChanges)
diff --git a/src/plugins/texteditor/refactoringchanges.h b/src/plugins/texteditor/refactoringchanges.h
index f291d390c19..6dae8c57d8b 100644
--- a/src/plugins/texteditor/refactoringchanges.h
+++ b/src/plugins/texteditor/refactoringchanges.h
@@ -52,7 +52,9 @@ public:
 
 public:
     RefactoringFile();
-    RefactoringFile(const QString &fileName, RefactoringChanges *refactoringChanges);
+    // takes ownership of document
+    RefactoringFile(QTextDocument *document, const QString &fileName = QString());
+    RefactoringFile(BaseTextEditorWidget *editor);
     RefactoringFile(const RefactoringFile &other);
     virtual ~RefactoringFile();
 
@@ -76,6 +78,7 @@ protected:
     // not assignable
     //const RefactoringFile &operator=(const RefactoringFile &other);
 
+    RefactoringFile(const QString &fileName, RefactoringChanges *refactoringChanges);
     QTextDocument *mutableDocument() const;
 
 protected:
@@ -86,6 +89,8 @@ protected:
     Utils::ChangeSet m_changes;
     QList<Range> m_indentRanges;
     bool m_openEditor;
+
+    friend class RefactoringChanges; // access to constructor
 };
 
  /*!