/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** 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 Digia.  For licensing terms and
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** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, 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, Digia gives you certain additional
** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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****************************************************************************/

#include "cppmodelmanager.h"

#include "abstracteditorsupport.h"
#include "builtinindexingsupport.h"
#include "cppcodemodelsettings.h"
#include "cppfindreferences.h"
#include "cpphighlightingsupport.h"
#include "cppindexingsupport.h"
#include "cppmodelmanagersupportinternal.h"
#include "cpppreprocessor.h"
#include "cpptoolsconstants.h"
#include "cpptoolseditorsupport.h"
#include "cpptoolsplugin.h"

#include <coreplugin/icore.h>
#include <coreplugin/progressmanager/progressmanager.h>
#include <projectexplorer/projectexplorer.h>
#include <projectexplorer/session.h>
#include <extensionsystem/pluginmanager.h>
#include <utils/qtcassert.h>

#include <QCoreApplication>
#include <QDebug>
#include <QMutexLocker>
#include <QTextBlock>
#include <QTimer>

#if defined(QTCREATOR_WITH_DUMP_AST) && defined(Q_CC_GNU)
#define WITH_AST_DUMP
#include <iostream>
#include <sstream>
#endif

namespace CppTools {

uint qHash(const ProjectPart &p)
{
    uint h = qHash(p.toolchainDefines) ^ qHash(p.projectDefines) ^ p.cVersion ^ p.cxxVersion
            ^ p.cxxExtensions ^ p.qtVersion;

    foreach (const QString &i, p.includePaths)
        h ^= qHash(i);

    foreach (const QString &f, p.frameworkPaths)
        h ^= qHash(f);

    return h;
}

bool operator==(const ProjectPart &p1,
                const ProjectPart &p2)
{
    if (p1.toolchainDefines != p2.toolchainDefines)
        return false;
    if (p1.projectDefines != p2.projectDefines)
        return false;
    if (p1.cVersion != p2.cVersion)
        return false;
    if (p1.cxxVersion != p2.cxxVersion)
        return false;
    if (p1.cxxExtensions != p2.cxxExtensions)
        return false;
    if (p1.qtVersion!= p2.qtVersion)
        return false;
    if (p1.includePaths != p2.includePaths)
        return false;
    return p1.frameworkPaths == p2.frameworkPaths;
}

} // namespace CppTools

using namespace CppTools;
using namespace CppTools::Internal;
using namespace CPlusPlus;

#ifdef QTCREATOR_WITH_DUMP_AST

#include <cxxabi.h>

class DumpAST: protected ASTVisitor
{
public:
    int depth;

    DumpAST(Control *control)
        : ASTVisitor(control), depth(0)
    { }

    void operator()(AST *ast)
    { accept(ast); }

protected:
    virtual bool preVisit(AST *ast)
    {
        std::ostringstream s;
        PrettyPrinter pp(control(), s);
        pp(ast);
        QString code = QString::fromStdString(s.str());
        code.replace('\n', ' ');
        code.replace(QRegExp("\\s+"), " ");

        const char *name = abi::__cxa_demangle(typeid(*ast).name(), 0, 0, 0) + 11;

        QByteArray ind(depth, ' ');
        ind += name;

        printf("%-40s %s\n", ind.constData(), qPrintable(code));
        ++depth;
        return true;
    }

    virtual void postVisit(AST *)
    { --depth; }
};

#endif // QTCREATOR_WITH_DUMP_AST

static const char pp_configuration[] =
    "# 1 \"<configuration>\"\n"
    "#define Q_CREATOR_RUN 1\n"
    "#define __cplusplus 1\n"
    "#define __extension__\n"
    "#define __context__\n"
    "#define __range__\n"
    "#define   restrict\n"
    "#define __restrict\n"
    "#define __restrict__\n"

    "#define __complex__\n"
    "#define __imag__\n"
    "#define __real__\n"

    "#define __builtin_va_arg(a,b) ((b)0)\n"

    // ### add macros for win32
    "#define __cdecl\n"
    "#define __stdcall\n"
    "#define QT_WA(x) x\n"
    "#define CALLBACK\n"
    "#define STDMETHODCALLTYPE\n"
    "#define __RPC_FAR\n"
    "#define __declspec(a)\n"
    "#define STDMETHOD(method) virtual HRESULT STDMETHODCALLTYPE method\n"
    "#define __try try\n"
    "#define __except catch\n"
    "#define __finally\n"
    "#define __inline inline\n"
    "#define __forceinline inline\n";

QStringList CppModelManager::timeStampModifiedFiles(const QList<Document::Ptr> documentsToCheck)
{
    QStringList sourceFiles;

    foreach (const Document::Ptr doc, documentsToCheck) {
        const QDateTime lastModified = doc->lastModified();

        if (!lastModified.isNull()) {
            QFileInfo fileInfo(doc->fileName());

            if (fileInfo.exists() && fileInfo.lastModified() != lastModified)
                sourceFiles.append(doc->fileName());
        }
    }

    return sourceFiles;
}

void CppModelManager::updateModifiedSourceFiles()
{
    const Snapshot snapshot = this->snapshot();
    QList<Document::Ptr> documentsToCheck;
    foreach (const Document::Ptr document, snapshot)
        documentsToCheck << document;

    const QStringList filesToUpdate = timeStampModifiedFiles(documentsToCheck);
    updateSourceFiles(filesToUpdate);
}

/*!
    \class CppTools::CppModelManager
    \brief The CppModelManager keeps tracks of the source files the code model is aware of.

    The CppModelManager manages the source files in a Snapshot object.

    The snapshot is updated in case e.g.
        * New files are opened/edited (Editor integration)
        * A project manager pushes updated project information (Project integration)
        * Files are garbage collected
*/

QMutex CppModelManager::m_instanceMutex;
CppModelManager *CppModelManager::m_instance = 0;

CppModelManager *CppModelManager::instance()
{
    if (m_instance)
        return m_instance;

    QMutexLocker locker(&m_instanceMutex);
    if (!m_instance)
        m_instance = new CppModelManager;

    return m_instance;
}

CppModelManager::CppModelManager(QObject *parent)
    : CppModelManagerInterface(parent)
    , m_indexingSupporter(0)
    , m_enableGC(true)
{
    connect(this, SIGNAL(documentUpdated(CPlusPlus::Document::Ptr)),
            this, SIGNAL(globalSnapshotChanged()));
    connect(this, SIGNAL(aboutToRemoveFiles(QStringList)),
            this, SIGNAL(globalSnapshotChanged()));

    m_findReferences = new CppFindReferences(this);
    m_indexerEnabled = qgetenv("QTCREATOR_NO_CODE_INDEXER").isNull();

    m_dirty = true;

    m_delayedGcTimer = new QTimer(this);
    m_delayedGcTimer->setSingleShot(true);
    connect(m_delayedGcTimer, SIGNAL(timeout()), this, SLOT(GC()));

    QObject *sessionManager = ProjectExplorer::SessionManager::instance();
    connect(sessionManager, SIGNAL(projectAdded(ProjectExplorer::Project*)),
            this, SLOT(onProjectAdded(ProjectExplorer::Project*)));
    connect(sessionManager, SIGNAL(aboutToRemoveProject(ProjectExplorer::Project*)),
            this, SLOT(onAboutToRemoveProject(ProjectExplorer::Project*)));
    connect(sessionManager, SIGNAL(aboutToLoadSession(QString)),
            this, SLOT(onAboutToLoadSession()));
    connect(sessionManager, SIGNAL(aboutToUnloadSession(QString)),
            this, SLOT(onAboutToUnloadSession()));

    connect(Core::ICore::instance(), SIGNAL(coreAboutToClose()),
            this, SLOT(onCoreAboutToClose()));

    qRegisterMetaType<CPlusPlus::Document::Ptr>("CPlusPlus::Document::Ptr");

    m_modelManagerSupportFallback.reset(new ModelManagerSupportInternal);
    CppToolsPlugin::instance()->codeModelSettings()->setDefaultId(
                m_modelManagerSupportFallback->id());
    addModelManagerSupport(m_modelManagerSupportFallback.data());

    m_internalIndexingSupport = new BuiltinIndexingSupport;
}

CppModelManager::~CppModelManager()
{
    delete m_internalIndexingSupport;
}

Snapshot CppModelManager::snapshot() const
{
    QMutexLocker locker(&m_snapshotMutex);
    return m_snapshot;
}

Document::Ptr CppModelManager::document(const QString &fileName) const
{
    QMutexLocker locker(&m_snapshotMutex);
    return m_snapshot.document(fileName);
}

/// Replace the document in the snapshot.
///
/// \returns true if successful, false if the new document is out-dated.
bool CppModelManager::replaceDocument(Document::Ptr newDoc)
{
    QMutexLocker locker(&m_snapshotMutex);

    Document::Ptr previous = m_snapshot.document(newDoc->fileName());
    if (previous && (newDoc->revision() != 0 && newDoc->revision() < previous->revision()))
        // the new document is outdated
        return false;

    m_snapshot.insert(newDoc);
    return true;
}

void CppModelManager::ensureUpdated()
{
    QMutexLocker locker(&m_projectMutex);
    if (!m_dirty)
        return;

    m_projectFiles = internalProjectFiles();
    m_includePaths = internalIncludePaths();
    m_frameworkPaths = internalFrameworkPaths();
    m_definedMacros = internalDefinedMacros();
    m_dirty = false;
}

QStringList CppModelManager::internalProjectFiles() const
{
    QStringList files;
    QMapIterator<ProjectExplorer::Project *, ProjectInfo> it(m_projectToProjectsInfo);
    while (it.hasNext()) {
        it.next();
        const ProjectInfo pinfo = it.value();
        foreach (const ProjectPart::Ptr &part, pinfo.projectParts()) {
            foreach (const ProjectFile &file, part->files)
                files += file.path;
        }
    }
    files.removeDuplicates();
    return files;
}

QStringList CppModelManager::internalIncludePaths() const
{
    QStringList includePaths;
    QMapIterator<ProjectExplorer::Project *, ProjectInfo> it(m_projectToProjectsInfo);
    while (it.hasNext()) {
        it.next();
        const ProjectInfo pinfo = it.value();
        foreach (const ProjectPart::Ptr &part, pinfo.projectParts())
            foreach (const QString &path, part->includePaths)
                includePaths.append(CppPreprocessor::cleanPath(path));
    }
    includePaths.removeDuplicates();
    return includePaths;
}

QStringList CppModelManager::internalFrameworkPaths() const
{
    QStringList frameworkPaths;
    QMapIterator<ProjectExplorer::Project *, ProjectInfo> it(m_projectToProjectsInfo);
    while (it.hasNext()) {
        it.next();
        const ProjectInfo pinfo = it.value();
        foreach (const ProjectPart::Ptr &part, pinfo.projectParts())
            foreach (const QString &path, part->frameworkPaths)
                frameworkPaths.append(CppPreprocessor::cleanPath(path));
    }
    frameworkPaths.removeDuplicates();
    return frameworkPaths;
}

static void addUnique(const QList<QByteArray> &defs, QByteArray *macros, QSet<QByteArray> *alreadyIn)
{
    Q_ASSERT(macros);
    Q_ASSERT(alreadyIn);

    foreach (const QByteArray &def, defs) {
        if (def.trimmed().isEmpty())
            continue;
        if (!alreadyIn->contains(def)) {
            macros->append(def);
            macros->append('\n');
            alreadyIn->insert(def);
        }
    }
}

QByteArray CppModelManager::internalDefinedMacros() const
{
    QByteArray macros;
    QSet<QByteArray> alreadyIn;
    QMapIterator<ProjectExplorer::Project *, ProjectInfo> it(m_projectToProjectsInfo);
    while (it.hasNext()) {
        it.next();
        const ProjectInfo pinfo = it.value();
        foreach (const ProjectPart::Ptr &part, pinfo.projectParts()) {
            addUnique(part->toolchainDefines.split('\n'), &macros, &alreadyIn);
            addUnique(part->projectDefines.split('\n'), &macros, &alreadyIn);
        }
    }
    return macros;
}

/// This function will aquire the mutex!
void CppModelManager::dumpModelManagerConfiguration()
{
    // Tons of debug output...
    qDebug() << "========= CppModelManager::dumpModelManagerConfiguration ======";
    foreach (const ProjectInfo &pinfo, m_projectToProjectsInfo) {
        qDebug() << " for project:"<< pinfo.project().data()->projectFilePath();
        foreach (const ProjectPart::Ptr &part, pinfo.projectParts()) {
            qDebug() << "=== part ===";
            const char* cVersion;
            switch (part->cVersion) {
            case ProjectPart::C89: cVersion = "C89"; break;
            case ProjectPart::C99: cVersion = "C99"; break;
            case ProjectPart::C11: cVersion = "C11"; break;
            default: cVersion = "INVALID";
            }
            const char* cxxVersion;
            switch (part->cxxVersion) {
            case ProjectPart::CXX98: cxxVersion = "CXX98"; break;
            case ProjectPart::CXX11: cxxVersion = "CXX11"; break;
            default: cxxVersion = "INVALID";
            }
            QStringList cxxExtensions;
            if (part->cxxExtensions & ProjectPart::GnuExtensions)
                cxxExtensions << QLatin1String("GnuExtensions");
            if (part->cxxExtensions & ProjectPart::MicrosoftExtensions)
                cxxExtensions << QLatin1String("MicrosoftExtensions");
            if (part->cxxExtensions & ProjectPart::BorlandExtensions)
                cxxExtensions << QLatin1String("BorlandExtensions");
            if (part->cxxExtensions & ProjectPart::OpenMPExtensions)
                cxxExtensions << QLatin1String("OpenMP");

            qDebug() << "cVersion:" << cVersion;
            qDebug() << "cxxVersion:" << cxxVersion;
            qDebug() << "cxxExtensions:" << cxxExtensions;
            qDebug() << "Qt version:" << part->qtVersion;
            qDebug() << "precompiled header:" << part->precompiledHeaders;
            qDebug() << "toolchain defines:" << part->toolchainDefines;
            qDebug() << "project defines:" << part->projectDefines;
            qDebug() << "includes:" << part->includePaths;
            qDebug() << "frameworkPaths:" << part->frameworkPaths;
            qDebug() << "files:" << part->files;
            qDebug() << "";
        }
    }

    ensureUpdated();
    qDebug() << "=== Merged include paths ===";
    foreach (const QString &inc, m_includePaths)
        qDebug() << inc;
    qDebug() << "=== Merged framework paths ===";
    foreach (const QString &inc, m_frameworkPaths)
        qDebug() << inc;
    qDebug() << "=== Merged defined macros ===";
    qDebug() << m_definedMacros;
    qDebug() << "========= End of dump ======";
}

void CppModelManager::addExtraEditorSupport(AbstractEditorSupport *editorSupport)
{
    m_extraEditorSupports.insert(editorSupport);
}

void CppModelManager::removeExtraEditorSupport(AbstractEditorSupport *editorSupport)
{
    m_extraEditorSupports.remove(editorSupport);
}

/// \brief Returns the \c CppEditorSupport for the given text editor. It will
///        create one when none exists yet.
CppEditorSupport *CppModelManager::cppEditorSupport(TextEditor::BaseTextEditor *textEditor)
{
    Q_ASSERT(textEditor);

    QMutexLocker locker(&m_cppEditorSupportsMutex);

    CppEditorSupport *editorSupport = m_cppEditorSupports.value(textEditor, 0);
    if (!editorSupport && isCppEditor(textEditor)) {
        editorSupport = new CppEditorSupport(this, textEditor);
        m_cppEditorSupports.insert(textEditor, editorSupport);
    }
    return editorSupport;
}

/// \brief Removes the CppEditorSupport for the closed editor.
void CppModelManager::deleteCppEditorSupport(TextEditor::BaseTextEditor *textEditor)
{
    static short numberOfClosedEditors = 0;

    QTC_ASSERT(textEditor, return);

    if (!isCppEditor(textEditor))
        return;

    CppEditorSupport *editorSupport;
    int numberOfOpenEditors = 0;

    { // Only lock the operations on m_cppEditorSupport
        QMutexLocker locker(&m_cppEditorSupportsMutex);
        editorSupport = m_cppEditorSupports.value(textEditor, 0);
        m_cppEditorSupports.remove(textEditor);
        numberOfOpenEditors = m_cppEditorSupports.size();
    }

    delete editorSupport;

    ++numberOfClosedEditors;
    if (numberOfOpenEditors == 0 || numberOfClosedEditors == 5) {
        numberOfClosedEditors = 0;
        delayedGC();
    }
}

QList<int> CppModelManager::references(CPlusPlus::Symbol *symbol, const LookupContext &context)
{
    return m_findReferences->references(symbol, context);
}

void CppModelManager::findUsages(CPlusPlus::Symbol *symbol, const CPlusPlus::LookupContext &context)
{
    if (symbol->identifier())
        m_findReferences->findUsages(symbol, context);
}

void CppModelManager::renameUsages(CPlusPlus::Symbol *symbol,
                                   const CPlusPlus::LookupContext &context,
                                   const QString &replacement)
{
    if (symbol->identifier())
        m_findReferences->renameUsages(symbol, context, replacement);
}

void CppModelManager::findMacroUsages(const CPlusPlus::Macro &macro)
{
    m_findReferences->findMacroUses(macro);
}

void CppModelManager::renameMacroUsages(const CPlusPlus::Macro &macro, const QString &replacement)
{
    m_findReferences->renameMacroUses(macro, replacement);
}

void CppModelManager::replaceSnapshot(const CPlusPlus::Snapshot &newSnapshot)
{
    QMutexLocker snapshotLocker(&m_snapshotMutex);
    m_snapshot = newSnapshot;
}

CppModelManager::WorkingCopy CppModelManager::buildWorkingCopyList()
{
    QList<CppEditorSupport *> cppEditorSupports;

    {
        QMutexLocker locker(&m_cppEditorSupportsMutex);
        cppEditorSupports = m_cppEditorSupports.values();
    }

    WorkingCopy workingCopy;
    foreach (const CppEditorSupport *editorSupport, cppEditorSupports) {
        workingCopy.insert(editorSupport->fileName(), editorSupport->contents(),
                           editorSupport->editorRevision());
    }

    QSetIterator<AbstractEditorSupport *> it(m_extraEditorSupports);
    while (it.hasNext()) {
        AbstractEditorSupport *es = it.next();
        workingCopy.insert(es->fileName(), es->contents(), es->revision());
    }

    // Add the project configuration file
    QByteArray conf = codeModelConfiguration();
    conf += definedMacros();
    workingCopy.insert(configurationFileName(), conf);

    return workingCopy;
}

CppModelManager::WorkingCopy CppModelManager::workingCopy() const
{
    return const_cast<CppModelManager *>(this)->buildWorkingCopyList();
}

QByteArray CppModelManager::codeModelConfiguration() const
{
    return QByteArray::fromRawData(pp_configuration, qstrlen(pp_configuration));
}

QFuture<void> CppModelManager::updateSourceFiles(const QStringList &sourceFiles,
                                                 ProgressNotificationMode mode)
{
    if (sourceFiles.isEmpty() || !m_indexerEnabled)
        return QFuture<void>();

    if (m_indexingSupporter)
        m_indexingSupporter->refreshSourceFiles(sourceFiles, mode);
    return m_internalIndexingSupport->refreshSourceFiles(sourceFiles, mode);
}

QList<CppModelManager::ProjectInfo> CppModelManager::projectInfos() const
{
    QMutexLocker locker(&m_projectMutex);
    return m_projectToProjectsInfo.values();
}

CppModelManager::ProjectInfo CppModelManager::projectInfo(ProjectExplorer::Project *project) const
{
    QMutexLocker locker(&m_projectMutex);
    return m_projectToProjectsInfo.value(project, ProjectInfo(project));
}

/// \brief Remove all files and their includes (recursively) of given ProjectInfo from the snapshot.
void CppModelManager::removeProjectInfoFilesAndIncludesFromSnapshot(const ProjectInfo &projectInfo)
{
    if (!projectInfo.isValid())
        return;

    QMutexLocker snapshotLocker(&m_snapshotMutex);
    foreach (const ProjectPart::Ptr &projectPart, projectInfo.projectParts()) {
        foreach (const ProjectFile &cxxFile, projectPart->files) {
            foreach (const QString &fileName, m_snapshot.allIncludesForDocument(cxxFile.path))
                m_snapshot.remove(fileName);
            m_snapshot.remove(cxxFile.path);
        }
    }
}

/// \brief Remove all given files from the snapshot.
void CppModelManager::removeFilesFromSnapshot(const QSet<QString> &filesToRemove)
{
    QMutexLocker snapshotLocker(&m_snapshotMutex);
    QSetIterator<QString> i(filesToRemove);
    while (i.hasNext())
        m_snapshot.remove(i.next());
}

class ProjectInfoComparer
{
public:
    ProjectInfoComparer(const CppModelManager::ProjectInfo &oldProjectInfo,
                        const CppModelManager::ProjectInfo &newProjectInfo)
        : m_old(oldProjectInfo)
        , m_oldSourceFiles(oldProjectInfo.sourceFiles().toSet())
        , m_new(newProjectInfo)
        , m_newSourceFiles(newProjectInfo.sourceFiles().toSet())
    {}

    bool definesChanged() const
    {
        return m_new.defines() != m_old.defines();
    }

    bool configurationChanged() const
    {
        return definesChanged()
            || m_new.includePaths() != m_old.includePaths()
            || m_new.frameworkPaths() != m_old.frameworkPaths();
    }

    bool nothingChanged() const
    {
        return !configurationChanged() && m_new.sourceFiles() == m_old.sourceFiles();
    }

    QSet<QString> addedFiles() const
    {
        QSet<QString> addedFilesSet = m_newSourceFiles;
        addedFilesSet.subtract(m_oldSourceFiles);
        return addedFilesSet;
    }

    QSet<QString> removedFiles() const
    {
        QSet<QString> removedFilesSet = m_oldSourceFiles;
        removedFilesSet.subtract(m_newSourceFiles);
        return removedFilesSet;
    }

    /// Returns a list of common files that have a changed timestamp.
    QSet<QString> timeStampModifiedFiles(const Snapshot &snapshot) const
    {
        QSet<QString> commonSourceFiles = m_newSourceFiles;
        commonSourceFiles.intersect(m_oldSourceFiles);

        QList<Document::Ptr> documentsToCheck;
        QSetIterator<QString> i(commonSourceFiles);
        while (i.hasNext()) {
            const QString file = i.next();
            if (Document::Ptr document = snapshot.document(file))
                documentsToCheck << document;
        }

        return CppModelManager::timeStampModifiedFiles(documentsToCheck).toSet();
    }

private:
    const CppModelManager::ProjectInfo &m_old;
    const QSet<QString> m_oldSourceFiles;

    const CppModelManager::ProjectInfo &m_new;
    const QSet<QString> m_newSourceFiles;
};

/// Make sure that m_projectMutex is locked when calling this.
void CppModelManager::recalculateFileToProjectParts()
{
    m_fileToProjectParts.clear();
    foreach (const ProjectInfo &projectInfo, m_projectToProjectsInfo) {
        foreach (const ProjectPart::Ptr &projectPart, projectInfo.projectParts()) {
            foreach (const ProjectFile &cxxFile, projectPart->files) {
                m_fileToProjectParts[cxxFile.path].append(projectPart);
            }
        }
    }
}

QFuture<void> CppModelManager::updateProjectInfo(const ProjectInfo &newProjectInfo)
{
    if (!newProjectInfo.isValid())
        return QFuture<void>();

    QStringList filesToReindex;
    bool filesRemoved = false;

    { // Only hold the mutex for a limited scope, so the dumping afterwards does not deadlock.
        QMutexLocker projectLocker(&m_projectMutex);

        ProjectExplorer::Project *project = newProjectInfo.project().data();
        const QStringList newSourceFiles = newProjectInfo.sourceFiles();

        // Check if we can avoid a full reindexing
        ProjectInfo oldProjectInfo = m_projectToProjectsInfo.value(project);
        if (oldProjectInfo.isValid()) {
            ProjectInfoComparer comparer(oldProjectInfo, newProjectInfo);
            if (comparer.nothingChanged())
                return QFuture<void>();

            // If the project configuration changed, do a full reindexing
            if (comparer.configurationChanged()) {
                removeProjectInfoFilesAndIncludesFromSnapshot(oldProjectInfo);
                filesToReindex << newSourceFiles;

                // The "configuration file" includes all defines and therefore should be updated
                if (comparer.definesChanged()) {
                    QMutexLocker snapshotLocker(&m_snapshotMutex);
                    m_snapshot.remove(configurationFileName());
                }

            // Otherwise check for added and modified files
            } else {
                const QSet<QString> addedFiles = comparer.addedFiles();
                filesToReindex << addedFiles.toList();

                const QSet<QString> modifiedFiles = comparer.timeStampModifiedFiles(snapshot());
                filesToReindex << modifiedFiles.toList();
            }

            // Announce and purge the removed files from the snapshot
            const QSet<QString> removedFiles = comparer.removedFiles();
            if (!removedFiles.isEmpty()) {
                filesRemoved = true;
                emit aboutToRemoveFiles(removedFiles.toList());
                removeFilesFromSnapshot(removedFiles);
            }

        // A new project was opened/created, do a full indexing
        } else {
            filesToReindex << newSourceFiles;
        }

        // Update Project/ProjectInfo and File/ProjectPart table
        m_dirty = true;
        m_projectToProjectsInfo.insert(project, newProjectInfo);
        recalculateFileToProjectParts();

    } // Mutex scope

    // If requested, dump everything we got
    if (!qgetenv("QTCREATOR_DUMP_PROJECT_INFO").isEmpty())
        dumpModelManagerConfiguration();

    // Remove files from snapshot that are not reachable any more
    if (filesRemoved)
        GC();

    emit projectPartsUpdated(newProjectInfo.project().data());

    // Trigger reindexing
    return updateSourceFiles(filesToReindex, ForcedProgressNotification);
}

QList<ProjectPart::Ptr> CppModelManager::projectPart(const QString &fileName) const
{
    return m_fileToProjectParts.value(fileName);
}

QList<ProjectPart::Ptr> CppModelManager::projectPartFromDependencies(const QString &fileName) const
{
    QSet<ProjectPart::Ptr> parts;
    DependencyTable table;
    table.build(snapshot());
    const QStringList deps = table.filesDependingOn(fileName);
    foreach (const QString &dep, deps)
        parts.unite(QSet<ProjectPart::Ptr>::fromList(m_fileToProjectParts.value(dep)));

    return parts.values();
}

ProjectPart::Ptr CppModelManager::fallbackProjectPart() const
{
    ProjectPart::Ptr part(new ProjectPart);

    part->projectDefines = m_definedMacros;
    part->includePaths = m_includePaths;
    part->frameworkPaths = m_frameworkPaths;
    part->cVersion = ProjectPart::C11;
    part->cxxVersion = ProjectPart::CXX11;
    part->cxxExtensions = ProjectPart::AllExtensions;
    part->qtVersion = ProjectPart::Qt5;

    return part;
}

bool CppModelManager::isCppEditor(Core::IEditor *editor) const
{
    return editor->context().contains(ProjectExplorer::Constants::LANG_CXX);
}

void CppModelManager::emitDocumentUpdated(Document::Ptr doc)
{
    if (replaceDocument(doc))
        emit documentUpdated(doc);
}

void CppModelManager::onProjectAdded(ProjectExplorer::Project *)
{
    QMutexLocker locker(&m_projectMutex);
    m_dirty = true;
}

void CppModelManager::delayedGC()
{
    m_delayedGcTimer->start(500);
}

void CppModelManager::onAboutToRemoveProject(ProjectExplorer::Project *project)
{
    do {
        QMutexLocker locker(&m_projectMutex);
        m_dirty = true;
        m_projectToProjectsInfo.remove(project);
        recalculateFileToProjectParts();
    } while (0);

    delayedGC();
}

void CppModelManager::onAboutToLoadSession()
{
    if (m_delayedGcTimer->isActive())
        m_delayedGcTimer->stop();
    GC();
}

void CppModelManager::onAboutToUnloadSession()
{
    Core::ProgressManager::cancelTasks(CppTools::Constants::TASK_INDEX);
    do {
        QMutexLocker locker(&m_projectMutex);
        m_projectToProjectsInfo.clear();
        recalculateFileToProjectParts();
        m_dirty = true;
    } while (0);
}

void CppModelManager::onCoreAboutToClose()
{
    m_enableGC = false;
}

void CppModelManager::GC()
{
    if (!m_enableGC)
        return;

    // Collect files of CppEditorSupport and AbstractEditorSupport.
    QStringList filesInEditorSupports;
    QList<CppEditorSupport *> cppEditorSupports;
    {
        QMutexLocker locker(&m_cppEditorSupportsMutex);
        cppEditorSupports = m_cppEditorSupports.values();
    }
    foreach (const CppEditorSupport *cppEditorSupport, cppEditorSupports)
        filesInEditorSupports << cppEditorSupport->fileName();

    QSetIterator<AbstractEditorSupport *> jt(m_extraEditorSupports);
    while (jt.hasNext()) {
        AbstractEditorSupport *abstractEditorSupport = jt.next();
        filesInEditorSupports << abstractEditorSupport->fileName();
    }

    Snapshot currentSnapshot = snapshot();
    QSet<QString> reachableFiles;
    // The configuration file is part of the project files, which is just fine.
    // If single files are open, without any project, then there is no need to
    // keep the configuration file around.
    QStringList todo = filesInEditorSupports + projectFiles();

    // Collect all files that are reachable from the project files
    while (!todo.isEmpty()) {
        const QString file = todo.last();
        todo.removeLast();

        if (reachableFiles.contains(file))
            continue;
        reachableFiles.insert(file);

        if (Document::Ptr doc = currentSnapshot.document(file))
            todo += doc->includedFiles();
    }

    // Find out the files in the current snapshot that are not reachable from the project files
    QStringList notReachableFiles;
    Snapshot newSnapshot;
    for (Snapshot::const_iterator it = currentSnapshot.begin(); it != currentSnapshot.end(); ++it) {
        const QString fileName = it.key();

        if (reachableFiles.contains(fileName))
            newSnapshot.insert(it.value());
        else
            notReachableFiles.append(fileName);
    }

    // Announce removing files and replace the snapshot
    emit aboutToRemoveFiles(notReachableFiles);
    replaceSnapshot(newSnapshot);
    emit gcFinished();
}

void CppModelManager::finishedRefreshingSourceFiles(const QStringList &files)
{
    emit sourceFilesRefreshed(files);
}

void CppModelManager::addModelManagerSupport(ModelManagerSupport *modelManagerSupport)
{
    Q_ASSERT(modelManagerSupport);
    m_idTocodeModelSupporter[modelManagerSupport->id()] = modelManagerSupport;
    QSharedPointer<CppCodeModelSettings> cms = CppToolsPlugin::instance()->codeModelSettings();
    cms->setModelManagerSupports(m_idTocodeModelSupporter.values());
}

ModelManagerSupport *CppModelManager::modelManagerSupportForMimeType(const QString &mimeType) const
{
    QSharedPointer<CppCodeModelSettings> cms = CppToolsPlugin::instance()->codeModelSettings();
    const QString &id = cms->modelManagerSupportId(mimeType);
    return m_idTocodeModelSupporter.value(id, m_modelManagerSupportFallback.data());
}

CppCompletionAssistProvider *CppModelManager::completionAssistProvider(Core::IEditor *editor) const
{
    ModelManagerSupport *cms = modelManagerSupportForMimeType(editor->document()->mimeType());

    return cms->completionAssistProvider();
}

CppHighlightingSupport *CppModelManager::highlightingSupport(Core::IEditor *editor) const
{
    TextEditor::ITextEditor *textEditor = qobject_cast<TextEditor::ITextEditor *>(editor);
    if (!textEditor)
        return 0;

    ModelManagerSupport *cms = modelManagerSupportForMimeType(editor->document()->mimeType());

    return cms->highlightingSupport(textEditor);
}

void CppModelManager::setIndexingSupport(CppIndexingSupport *indexingSupport)
{
    if (indexingSupport)
        m_indexingSupporter = indexingSupport;
}

CppIndexingSupport *CppModelManager::indexingSupport()
{
    return m_indexingSupporter ? m_indexingSupporter : m_internalIndexingSupport;
}

void CppModelManager::setExtraDiagnostics(const QString &fileName,
                                          const QString &kind,
                                          const QList<Document::DiagnosticMessage> &diagnostics)
{
    QList<CppEditorSupport *> cppEditorSupports;

    {
        QMutexLocker locker(&m_cppEditorSupportsMutex);
        cppEditorSupports = m_cppEditorSupports.values();
    }

    foreach (CppEditorSupport *editorSupport, cppEditorSupports) {
        if (editorSupport->fileName() == fileName) {
            editorSupport->setExtraDiagnostics(kind, diagnostics);
            break;
        }
    }
}

void CppModelManager::setIfdefedOutBlocks(const QString &fileName,
                                          const QList<TextEditor::BlockRange> &ifdeffedOutBlocks)
{
    QList<CppEditorSupport *> cppEditorSupports;

    {
        QMutexLocker locker(&m_cppEditorSupportsMutex);
        cppEditorSupports = m_cppEditorSupports.values();
    }

    foreach (CppEditorSupport *editorSupport, cppEditorSupports) {
        if (editorSupport->fileName() == fileName) {
            editorSupport->setIfdefedOutBlocks(ifdeffedOutBlocks);
            break;
        }
    }
}