Merge branch '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-1 into 4.7-integration

* '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-1:
  uic: Fix compile breakage in case QT_NO_QT3_SUPPORT.
  uic: Improve messages.
  Tools (uic/rcc): Improve warning messages.
  QDir: Removed checks for existance of fileEngine
  QDir and QFileInfo shouldn't lose properties when detaching
  Another bug-o introduced in fixing QDirPrivate refactoring
  Reverting QDir::detach introduced earlier
  QFileInfo: Prepare for engine-less implementation
  Removed QFileInfoPrivate::initFileEngine
  Simplify QDir::cd
  QDir::makeAbsolute could self-destruct on failure
  QDir::operator= simplification
  QDirPrivate refactoring
  QDirPrivate refactoring
  QDirPrivate refactoring
  Removed QDirPrivate layer of indirection
  Refactor QFileInfoPrivate::Data (Round 2)
  Refactoring QDirPrivate::Data
  Move QFileInfoPrivate methods to QFileInfoPrivate::Data (1st Round)
  explicitly remove qt_webkit_version.pri when building with -no-webkit

11 files changed, 435 insertions, 470 deletions

diff --git a/src/corelib/io/qdir.cpp b/src/corelib/io/qdir.cpp
index e54d95e..fcd17f7 100644
--- a/src/corelib/io/qdir.cpp
+++ b/src/corelib/io/qdir.cpp
@@ -82,20 +82,69 @@ static QString driveSpec(const QString &path)
 
 //************* QDirPrivate
 class QDirPrivate
+    : public QSharedData
 {
-    friend struct QScopedPointerDeleter<QDirPrivate>;
-
 public:
-    QDirPrivate(const QDir *copy = 0);
-    ~QDirPrivate();
-
-    void updateFileLists() const;
-    void sortFileList(QDir::SortFlags, QFileInfoList &, QStringList *, QFileInfoList *) const;
+    QDirPrivate(const QString &path,
+            const QStringList &nameFilters_ = QStringList(),
+            QDir::SortFlags sort_ = QDir::SortFlags(QDir::Name | QDir::IgnoreCase),
+            QDir::Filters filters_ = QDir::AllEntries)
+        : QSharedData()
+        , nameFilters(nameFilters_)
+        , sort(sort_)
+        , filters(filters_)
+#ifdef QT3_SUPPORT
+        , filterSepChar(0)
+        , matchAllDirs(false)
+#endif
+        , fileListsInitialized(false)
+    {
+        setPath(path.isEmpty() ? QString::fromLatin1(".") : path);
+
+        bool empty = nameFilters.isEmpty();
+        if (!empty) {
+            empty = true;
+            for (int i = 0; i < nameFilters.size(); ++i) {
+                if (!nameFilters.at(i).isEmpty()) {
+                    empty = false;
+                    break;
+                }
+            }
+        }
+        if (empty)
+            nameFilters = QStringList(QString::fromLatin1("*"));
+    }
 
+    QDirPrivate(const QDirPrivate &copy)
+        : QSharedData(copy)
+        , path(copy.path)
+        , nameFilters(copy.nameFilters)
+        , sort(copy.sort)
+        , filters(copy.filters)
 #ifdef QT3_SUPPORT
-    QChar filterSepChar;
-    bool matchAllDirs;
+        , filterSepChar(copy.filterSepChar)
+        , matchAllDirs(copy.matchAllDirs)
 #endif
+        , fileListsInitialized(false)
+    {
+    }
+
+    bool exists() const
+    {
+        const QAbstractFileEngine::FileFlags info =
+            fileEngine->fileFlags(QAbstractFileEngine::DirectoryType
+                                           | QAbstractFileEngine::ExistsFlag
+                                           | QAbstractFileEngine::Refresh);
+        if (!(info & QAbstractFileEngine::DirectoryType))
+            return false;
+        return info & QAbstractFileEngine::ExistsFlag;
+    }
+
+    void initFileEngine();
+    void initFileLists() const;
+
+    static void sortFileList(QDir::SortFlags, QFileInfoList &, QStringList *, QFileInfoList *);
+
     static inline QChar getFilterSepChar(const QString &nameFilter)
     {
         QChar sep(QLatin1Char(';'));
@@ -104,7 +153,9 @@ public:
             sep = QChar(QLatin1Char(' '));
         return sep;
     }
-    static inline QStringList splitFilters(const QString &nameFilter, QChar sep = 0) {
+
+    static inline QStringList splitFilters(const QString &nameFilter, QChar sep = 0)
+    {
         if (sep == 0)
             sep = getFilterSepChar(nameFilter);
         QStringList ret = nameFilter.split(sep);
@@ -113,80 +164,46 @@ public:
         return ret;
     }
 
-    struct Data {
-        inline Data()
-            : ref(1), fileEngine(0), listsDirty(1)
-        {}
-        inline Data(const Data &copy)
-            : ref(1), path(copy.path), nameFilters(copy.nameFilters), sort(copy.sort),
-              filters(copy.filters), fileEngine(0), listsDirty(1)
-        {}
-        inline ~Data()
-        { delete fileEngine; }
-
-        inline void clear() {
-            listsDirty = 1;
-            files.clear();
-            fileInfos.clear();
-        }
-        mutable QAtomicInt ref;
-
-        QString path;
-        QStringList nameFilters;
-        QDir::SortFlags sort;
-        QDir::Filters filters;
-
-        mutable QAbstractFileEngine *fileEngine;
-
-        mutable uint listsDirty : 1;
-        mutable QStringList files;
-        mutable QFileInfoList fileInfos;
-    } *data;
-    inline void setPath(const QString &p)
+    inline void setPath(QString p)
     {
-        detach(false);
-        QString path = p;
-        if ((path.endsWith(QLatin1Char('/')) || path.endsWith(QLatin1Char('\\')))
-                && path.length() > 1) {
+        if ((p.endsWith(QLatin1Char('/')) || p.endsWith(QLatin1Char('\\')))
+                && p.length() > 1) {
 #if defined(Q_OS_WIN) || defined(Q_OS_SYMBIAN)
-            if (!(path.length() == 3 && path.at(1) == QLatin1Char(':')))
+            if (!(p.length() == 3 && p.at(1) == QLatin1Char(':')))
 #endif
-                path.truncate(path.length() - 1);
+                p.truncate(p.length() - 1);
         }
 
-        delete data->fileEngine;
-        data->fileEngine = QAbstractFileEngine::create(path);
+        path = p;
+        initFileEngine();
 
         // set the path to be the qt friendly version so then we can operate on it using just /
-        data->path = data->fileEngine->fileName(QAbstractFileEngine::DefaultName);
-        data->clear();
+        path = fileEngine->fileName(QAbstractFileEngine::DefaultName);
+        clearFileLists();
     }
-    inline void reset() {
-        detach();
-        data->clear();
+
+    inline void clearFileLists() {
+        fileListsInitialized = false;
+        files.clear();
+        fileInfos.clear();
     }
-    void detach(bool createFileEngine = true);
-};
 
-QDirPrivate::QDirPrivate(const QDir *copy)
+    QString path;
+    QStringList nameFilters;
+    QDir::SortFlags sort;
+    QDir::Filters filters;
+
 #ifdef QT3_SUPPORT
-    : filterSepChar(0), matchAllDirs(false)
+    QChar filterSepChar;
+    bool matchAllDirs;
 #endif
-{
-    if (copy) {
-        copy->d_func()->data->ref.ref();
-        data = copy->d_func()->data;
-    } else {
-        data = new QDirPrivate::Data;
-    }
-}
 
-QDirPrivate::~QDirPrivate()
-{
-    if (!data->ref.deref())
-        delete data;
-    data = 0;
-}
+    QScopedPointer<QAbstractFileEngine> fileEngine;
+
+    mutable bool fileListsInitialized;
+    mutable QStringList files;
+    mutable QFileInfoList fileInfos;
+};
 
 /* For sorting */
 struct QDirSortItem
@@ -269,7 +286,7 @@ bool QDirSortItemComparator::operator()(const QDirSortItem &n1, const QDirSortIt
 }
 
 inline void QDirPrivate::sortFileList(QDir::SortFlags sort, QFileInfoList &l,
-                                      QStringList *names, QFileInfoList *infos) const
+                                      QStringList *names, QFileInfoList *infos)
 {
     // names and infos are always empty lists or 0 here
     int n = l.size();
@@ -299,28 +316,23 @@ inline void QDirPrivate::sortFileList(QDir::SortFlags sort, QFileInfoList &l,
     }
 }
 
-inline void QDirPrivate::updateFileLists() const
+inline void QDirPrivate::initFileLists() const
 {
-    if (data->listsDirty) {
+    if (!fileListsInitialized) {
         QFileInfoList l;
-        QDirIterator it(data->path, data->nameFilters, data->filters);
+        QDirIterator it(path, nameFilters, filters);
         while (it.hasNext()) {
             it.next();
             l.append(it.fileInfo());
         }
-        sortFileList(data->sort, l, &data->files, &data->fileInfos);
-        data->listsDirty = 0;
+        sortFileList(sort, l, &files, &fileInfos);
+        fileListsInitialized = true;
     }
 }
 
-void QDirPrivate::detach(bool createFileEngine)
+inline void QDirPrivate::initFileEngine()
 {
-    qAtomicDetach(data);
-    if (createFileEngine) {
-        QAbstractFileEngine *newFileEngine = QAbstractFileEngine::create(data->path);
-        delete data->fileEngine;
-        data->fileEngine = newFileEngine;
-    }
+    fileEngine.reset(QAbstractFileEngine::create(path));
 }
 
 /*!
@@ -504,13 +516,8 @@ void QDirPrivate::detach(bool createFileEngine)
 
     \sa currentPath()
 */
-QDir::QDir(const QString &path) : d_ptr(new QDirPrivate)
+QDir::QDir(const QString &path) : d_ptr(new QDirPrivate(path))
 {
-    Q_D(QDir);
-    d->setPath(path.isEmpty() ? QString::fromLatin1(".") : path);
-    d->data->nameFilters = QStringList(QString::fromLatin1("*"));
-    d->data->filters = AllEntries;
-    d->data->sort = SortFlags(Name | IgnoreCase);
 }
 
 /*!
@@ -532,25 +539,9 @@ QDir::QDir(const QString &path) : d_ptr(new QDirPrivate)
     \sa exists(), setPath(), setNameFilter(), setFilter(), setSorting()
 */
 QDir::QDir(const QString &path, const QString &nameFilter,
-           SortFlags sort, Filters filters) : d_ptr(new QDirPrivate)
-{
-    Q_D(QDir);
-    d->setPath(path.isEmpty() ? QString::fromLatin1(".") : path);
-    d->data->nameFilters = QDir::nameFiltersFromString(nameFilter);
-    bool empty = d->data->nameFilters.isEmpty();
-    if (!empty) {
-        empty = true;
-        for (int i = 0; i < d->data->nameFilters.size(); ++i) {
-            if (!d->data->nameFilters.at(i).isEmpty()) {
-                empty = false;
-                break;
-            }
-        }
-    }
-    if (empty)
-        d->data->nameFilters = QStringList(QString::fromLatin1("*"));
-    d->data->sort = sort;
-    d->data->filters = filters;
+           SortFlags sort, Filters filters)
+    : d_ptr(new QDirPrivate(path, QDir::nameFiltersFromString(nameFilter), sort, filters))
+{
 }
 
 /*!
@@ -559,7 +550,8 @@ QDir::QDir(const QString &path, const QString &nameFilter,
 
     \sa operator=()
 */
-QDir::QDir(const QDir &dir) : d_ptr(new QDirPrivate(&dir))
+QDir::QDir(const QDir &dir)
+    : d_ptr(dir.d_ptr)
 {
 }
 
@@ -589,8 +581,7 @@ QDir::~QDir()
 */
 void QDir::setPath(const QString &path)
 {
-    Q_D(QDir);
-    d->setPath(path);
+    d_ptr->setPath(path);
 }
 
 /*!
@@ -605,8 +596,8 @@ void QDir::setPath(const QString &path)
 */
 QString QDir::path() const
 {
-    Q_D(const QDir);
-    return d->data->path;
+    const QDirPrivate* d = d_ptr.constData();
+    return d->path;
 }
 
 /*!
@@ -619,8 +610,8 @@ QString QDir::path() const
 */
 QString QDir::absolutePath() const
 {
-    Q_D(const QDir);
-    QString ret = d->data->path;
+    const QDirPrivate* d = d_ptr.constData();
+    QString ret = d->path;
     if (QDir::isRelativePath(ret))
         ret = absoluteFilePath(QString::fromLatin1(""));
     return cleanPath(ret);
@@ -644,11 +635,7 @@ QString QDir::absolutePath() const
 */
 QString QDir::canonicalPath() const
 {
-    Q_D(const QDir);
-
-    if (!d->data->fileEngine)
-        return QLatin1String("");
-    return cleanPath(d->data->fileEngine->fileName(QAbstractFileEngine::CanonicalName));
+    return cleanPath(d_ptr->fileEngine->fileName(QAbstractFileEngine::CanonicalName));
 }
 
 /*!
@@ -664,11 +651,11 @@ QString QDir::canonicalPath() const
 */
 QString QDir::dirName() const
 {
-    Q_D(const QDir);
-    int pos = d->data->path.lastIndexOf(QLatin1Char('/'));
+    const QDirPrivate* d = d_ptr.constData();
+    int pos = d->path.lastIndexOf(QLatin1Char('/'));
     if (pos == -1)
-        return d->data->path;
-    return d->data->path.mid(pos + 1);
+        return d->path;
+    return d->path.mid(pos + 1);
 }
 
 /*!
@@ -682,11 +669,11 @@ QString QDir::dirName() const
 */
 QString QDir::filePath(const QString &fileName) const
 {
-    Q_D(const QDir);
+    const QDirPrivate* d = d_ptr.constData();
     if (isAbsolutePath(fileName))
         return QString(fileName);
 
-    QString ret = d->data->path;
+    QString ret = d->path;
     if (!fileName.isEmpty()) {
         if (!ret.isEmpty() && ret[(int)ret.length()-1] != QLatin1Char('/') && fileName[0] != QLatin1Char('/'))
             ret += QLatin1Char('/');
@@ -705,21 +692,19 @@ QString QDir::filePath(const QString &fileName) const
 */
 QString QDir::absoluteFilePath(const QString &fileName) const
 {
-    Q_D(const QDir);
+    const QDirPrivate* d = d_ptr.constData();
     if (isAbsolutePath(fileName))
         return fileName;
-    if (!d->data->fileEngine)
-        return fileName;
 
     QString ret;
 #ifndef QT_NO_FSFILEENGINE
-    if (isRelativePath(d->data->path)) //get pwd
+    if (isRelativePath(d->path)) //get pwd
         ret = QFSFileEngine::currentPath(fileName);
 #endif
-    if (!d->data->path.isEmpty() && d->data->path != QLatin1String(".")) {
+    if (!d->path.isEmpty() && d->path != QLatin1String(".")) {
         if (!ret.isEmpty() && !ret.endsWith(QLatin1Char('/')))
             ret += QLatin1Char('/');
-        ret += d->data->path;
+        ret += d->path;
     }
     if (!fileName.isEmpty()) {
         if (!ret.isEmpty() && !ret.endsWith(QLatin1Char('/')))
@@ -867,11 +852,12 @@ QString QDir::fromNativeSeparators(const QString &pathName)
 */
 bool QDir::cd(const QString &dirName)
 {
-    Q_D(QDir);
+    // Don't detach just yet.
+    const QDirPrivate * const d = d_ptr.constData();
 
     if (dirName.isEmpty() || dirName == QLatin1String("."))
         return true;
-    QString newPath = d->data->path;
+    QString newPath = d->path;
     if (isAbsolutePath(dirName)) {
         newPath = cleanPath(dirName);
     } else {
@@ -884,7 +870,7 @@ bool QDir::cd(const QString &dirName)
 
         newPath += dirName;
         if (dirName.indexOf(QLatin1Char('/')) >= 0
-            || d->data->path == QLatin1String(".")
+            || d->path == QLatin1String(".")
             || dirName == QLatin1String("..")) {
             newPath = cleanPath(newPath);
             /*
@@ -901,12 +887,13 @@ bool QDir::cd(const QString &dirName)
         }
     }
 
-    QDir dir(*this);
-    dir.setPath(newPath);
-    if (!dir.exists())
+    QScopedPointer<QDirPrivate> dir(new QDirPrivate(*d_ptr.constData()));
+    dir->setPath(newPath);
+
+    if (!dir->exists())
         return false;
 
-    *this = dir;
+    d_ptr = dir.take();
     return true;
 }
 
@@ -930,9 +917,8 @@ bool QDir::cdUp()
 */
 QStringList QDir::nameFilters() const
 {
-    Q_D(const QDir);
-
-    return d->data->nameFilters;
+    const QDirPrivate* d = d_ptr.constData();
+    return d->nameFilters;
 }
 
 /*!
@@ -952,10 +938,11 @@ QStringList QDir::nameFilters() const
 */
 void QDir::setNameFilters(const QStringList &nameFilters)
 {
-    Q_D(QDir);
+    QDirPrivate* d = d_ptr.data();
+    d->initFileEngine();
+    d->clearFileLists();
 
-    d->reset();
-    d->data->nameFilters = nameFilters;
+    d->nameFilters = nameFilters;
 }
 
 /*!
@@ -1058,9 +1045,8 @@ QStringList QDir::searchPaths(const QString &prefix)
 */
 QDir::Filters QDir::filter() const
 {
-    Q_D(const QDir);
-
-    return d->data->filters;
+    const QDirPrivate* d = d_ptr.constData();
+    return d->filters;
 }
 
 /*!
@@ -1141,10 +1127,11 @@ QDir::Filters QDir::filter() const
 */
 void QDir::setFilter(Filters filters)
 {
-    Q_D(QDir);
+    QDirPrivate* d = d_ptr.data();
+    d->initFileEngine();
+    d->clearFileLists();
 
-    d->reset();
-    d->data->filters = filters;
+    d->filters = filters;
 }
 
 /*!
@@ -1154,9 +1141,8 @@ void QDir::setFilter(Filters filters)
 */
 QDir::SortFlags QDir::sorting() const
 {
-    Q_D(const QDir);
-
-    return d->data->sort;
+    const QDirPrivate* d = d_ptr.constData();
+    return d->sort;
 }
 
 /*!
@@ -1199,10 +1185,11 @@ QDir::SortFlags QDir::sorting() const
 */
 void QDir::setSorting(SortFlags sort)
 {
-    Q_D(QDir);
+    QDirPrivate* d = d_ptr.data();
+    d->initFileEngine();
+    d->clearFileLists();
 
-    d->reset();
-    d->data->sort = sort;
+    d->sort = sort;
 }
 
 /*!
@@ -1214,10 +1201,9 @@ void QDir::setSorting(SortFlags sort)
 */
 uint QDir::count() const
 {
-    Q_D(const QDir);
-
-    d->updateFileLists();
-    return d->data->files.count();
+    const QDirPrivate* d = d_ptr.constData();
+    d->initFileLists();
+    return d->files.count();
 }
 
 /*!
@@ -1229,10 +1215,9 @@ uint QDir::count() const
 */
 QString QDir::operator[](int pos) const
 {
-    Q_D(const QDir);
-
-    d->updateFileLists();
-    return d->data->files[pos];
+    const QDirPrivate* d = d_ptr.constData();
+    d->initFileLists();
+    return d->files[pos];
 }
 
 /*!
@@ -1256,9 +1241,8 @@ QString QDir::operator[](int pos) const
 */
 QStringList QDir::entryList(Filters filters, SortFlags sort) const
 {
-    Q_D(const QDir);
-
-    return entryList(d->data->nameFilters, filters, sort);
+    const QDirPrivate* d = d_ptr.constData();
+    return entryList(d->nameFilters, filters, sort);
 }
 
 
@@ -1280,9 +1264,8 @@ QStringList QDir::entryList(Filters filters, SortFlags sort) const
 */
 QFileInfoList QDir::entryInfoList(Filters filters, SortFlags sort) const
 {
-    Q_D(const QDir);
-
-    return entryInfoList(d->data->nameFilters, filters, sort);
+    const QDirPrivate* d = d_ptr.constData();
+    return entryInfoList(d->nameFilters, filters, sort);
 }
 
 /*!
@@ -1304,24 +1287,24 @@ QFileInfoList QDir::entryInfoList(Filters filters, SortFlags sort) const
 QStringList QDir::entryList(const QStringList &nameFilters, Filters filters,
                             SortFlags sort) const
 {
-    Q_D(const QDir);
+    const QDirPrivate* d = d_ptr.constData();
 
     if (filters == NoFilter)
-        filters = d->data->filters;
+        filters = d->filters;
 #ifdef QT3_SUPPORT
     if (d->matchAllDirs)
         filters |= AllDirs;
 #endif
     if (sort == NoSort)
-        sort = d->data->sort;
+        sort = d->sort;
 
-    if (filters == d->data->filters && sort == d->data->sort && nameFilters == d->data->nameFilters) {
-        d->updateFileLists();
-        return d->data->files;
+    if (filters == d->filters && sort == d->sort && nameFilters == d->nameFilters) {
+        d->initFileLists();
+        return d->files;
     }
 
     QFileInfoList l;
-    QDirIterator it(d->data->path, nameFilters, filters);
+    QDirIterator it(d->path, nameFilters, filters);
     while (it.hasNext()) {
         it.next();
         l.append(it.fileInfo());
@@ -1350,24 +1333,24 @@ QStringList QDir::entryList(const QStringList &nameFilters, Filters filters,
 QFileInfoList QDir::entryInfoList(const QStringList &nameFilters, Filters filters,
                                   SortFlags sort) const
 {
-    Q_D(const QDir);
+    const QDirPrivate* d = d_ptr.constData();
 
     if (filters == NoFilter)
-        filters = d->data->filters;
+        filters = d->filters;
 #ifdef QT3_SUPPORT
     if (d->matchAllDirs)
         filters |= AllDirs;
 #endif
     if (sort == NoSort)
-        sort = d->data->sort;
+        sort = d->sort;
 
-    if (filters == d->data->filters && sort == d->data->sort && nameFilters == d->data->nameFilters) {
-        d->updateFileLists();
-        return d->data->fileInfos;
+    if (filters == d->filters && sort == d->sort && nameFilters == d->nameFilters) {
+        d->initFileLists();
+        return d->fileInfos;
     }
 
     QFileInfoList l;
-    QDirIterator it(d->data->path, nameFilters, filters);
+    QDirIterator it(d->path, nameFilters, filters);
     while (it.hasNext()) {
         it.next();
         l.append(it.fileInfo());
@@ -1386,17 +1369,15 @@ QFileInfoList QDir::entryInfoList(const QStringList &nameFilters, Filters filter
 */
 bool QDir::mkdir(const QString &dirName) const
 {
-    Q_D(const QDir);
+    const QDirPrivate* d = d_ptr.constData();
 
     if (dirName.isEmpty()) {
         qWarning("QDir::mkdir: Empty or null file name(s)");
         return false;
     }
-    if (!d->data->fileEngine)
-        return false;
 
     QString fn = filePath(dirName);
-    return d->data->fileEngine->mkdir(fn, false);
+    return d->fileEngine->mkdir(fn, false);
 }
 
 /*!
@@ -1410,17 +1391,15 @@ bool QDir::mkdir(const QString &dirName) const
 */
 bool QDir::rmdir(const QString &dirName) const
 {
-    Q_D(const QDir);
+    const QDirPrivate* d = d_ptr.constData();
 
     if (dirName.isEmpty()) {
         qWarning("QDir::rmdir: Empty or null file name(s)");
         return false;
     }
-    if (!d->data->fileEngine)
-        return false;
 
     QString fn = filePath(dirName);
-    return d->data->fileEngine->rmdir(fn, false);
+    return d->fileEngine->rmdir(fn, false);
 }
 
 /*!
@@ -1435,17 +1414,15 @@ bool QDir::rmdir(const QString &dirName) const
 */
 bool QDir::mkpath(const QString &dirPath) const
 {
-    Q_D(const QDir);
+    const QDirPrivate* d = d_ptr.constData();
 
     if (dirPath.isEmpty()) {
         qWarning("QDir::mkpath: Empty or null file name(s)");
         return false;
     }
-    if (!d->data->fileEngine)
-        return false;
 
     QString fn = filePath(dirPath);
-    return d->data->fileEngine->mkdir(fn, true);
+    return d->fileEngine->mkdir(fn, true);
 }
 
 /*!
@@ -1461,17 +1438,15 @@ bool QDir::mkpath(const QString &dirPath) const
 */
 bool QDir::rmpath(const QString &dirPath) const
 {
-    Q_D(const QDir);
+    const QDirPrivate* d = d_ptr.constData();
 
     if (dirPath.isEmpty()) {
         qWarning("QDir::rmpath: Empty or null file name(s)");
         return false;
     }
-    if (!d->data->fileEngine)
-        return false;
 
     QString fn = filePath(dirPath);
-    return d->data->fileEngine->rmdir(fn, true);
+    return d->fileEngine->rmdir(fn, true);
 }
 
 /*!
@@ -1485,12 +1460,10 @@ bool QDir::rmpath(const QString &dirPath) const
 */
 bool QDir::isReadable() const
 {
-    Q_D(const QDir);
+    const QDirPrivate* d = d_ptr.constData();
 
-    if (!d->data->fileEngine)
-        return false;
     const QAbstractFileEngine::FileFlags info =
-        d->data->fileEngine->fileFlags(QAbstractFileEngine::DirectoryType
+        d->fileEngine->fileFlags(QAbstractFileEngine::DirectoryType
                                        | QAbstractFileEngine::PermsMask);
     if (!(info & QAbstractFileEngine::DirectoryType))
         return false;
@@ -1510,17 +1483,7 @@ bool QDir::isReadable() const
 */
 bool QDir::exists() const
 {
-    Q_D(const QDir);
-
-    if (!d->data->fileEngine)
-        return false;
-    const QAbstractFileEngine::FileFlags info =
-        d->data->fileEngine->fileFlags(QAbstractFileEngine::DirectoryType
-                                       | QAbstractFileEngine::ExistsFlag
-                                       | QAbstractFileEngine::Refresh);
-    if (!(info & QAbstractFileEngine::DirectoryType))
-        return false;
-    return info & QAbstractFileEngine::ExistsFlag;
+    return d_ptr->exists();
 }
 
 /*!
@@ -1537,11 +1500,7 @@ bool QDir::exists() const
 */
 bool QDir::isRoot() const
 {
-    Q_D(const QDir);
-
-    if (!d->data->fileEngine)
-        return true;
-    return d->data->fileEngine->fileFlags(QAbstractFileEngine::FlagsMask) & QAbstractFileEngine::RootFlag;
+    return d_ptr->fileEngine->fileFlags(QAbstractFileEngine::FlagsMask) & QAbstractFileEngine::RootFlag;
 }
 
 /*!
@@ -1571,11 +1530,7 @@ bool QDir::isRoot() const
 */
 bool QDir::isRelative() const
 {
-    Q_D(const QDir);
-
-    if (!d->data->fileEngine)
-        return false;
-    return d->data->fileEngine->isRelativePath();
+    return d_ptr->fileEngine->isRelativePath();
 }
 
 
@@ -1588,18 +1543,17 @@ bool QDir::isRelative() const
 */
 bool QDir::makeAbsolute() // ### What do the return values signify?
 {
-    Q_D(QDir);
-
-    if (!d->data->fileEngine)
-        return false;
-    QString absolutePath = d->data->fileEngine->fileName(QAbstractFileEngine::AbsoluteName);
+    QString absolutePath = d_ptr.constData()->fileEngine->fileName(QAbstractFileEngine::AbsoluteName);
     if (QDir::isRelativePath(absolutePath))
         return false;
-    d->detach();
-    d->data->path = absolutePath;
-    d->data->fileEngine->setFileName(absolutePath);
-    if (!(d->data->fileEngine->fileFlags(QAbstractFileEngine::TypesMask) & QAbstractFileEngine::DirectoryType))
+
+    QScopedPointer<QDirPrivate> dir(new QDirPrivate(*d_ptr.constData()));
+    dir->setPath(absolutePath);
+
+    if (!(dir->fileEngine->fileFlags(QAbstractFileEngine::TypesMask) & QAbstractFileEngine::DirectoryType))
         return false;
+
+    d_ptr = dir.take();
     return true;
 }
 
@@ -1614,19 +1568,18 @@ bool QDir::makeAbsolute() // ### What do the return values signify?
 */
 bool QDir::operator==(const QDir &dir) const
 {
-    const QDirPrivate *d = d_func();
-    const QDirPrivate *other = dir.d_func();
+    const QDirPrivate *d = d_ptr.constData();
+    const QDirPrivate *other = dir.d_ptr.constData();
 
-    if (d->data == other->data)
+    if (d == other)
         return true;
-    Q_ASSERT(d->data->fileEngine && other->data->fileEngine);
-    if (d->data->fileEngine->caseSensitive() != other->data->fileEngine->caseSensitive())
+    if (d->fileEngine->caseSensitive() != other->fileEngine->caseSensitive())
         return false;
-    if (d->data->filters == other->data->filters
-       && d->data->sort == other->data->sort
-       && d->data->nameFilters == other->data->nameFilters) {
+    if (d->filters == other->filters
+       && d->sort == other->sort
+       && d->nameFilters == other->nameFilters) {
         QString dir1 = absolutePath(), dir2 = dir.absolutePath();
-        if (!other->data->fileEngine->caseSensitive())
+        if (!other->fileEngine->caseSensitive())
             return (dir1.toLower() == dir2.toLower());
 
         return (dir1 == dir2);
@@ -1641,11 +1594,7 @@ bool QDir::operator==(const QDir &dir) const
 */
 QDir &QDir::operator=(const QDir &dir)
 {
-    if (this == &dir)
-        return *this;
-
-    Q_D(QDir);
-    qAtomicAssign(d->data, dir.d_func()->data);
+    d_ptr = dir.d_ptr;
     return *this;
 }
 
@@ -1659,9 +1608,7 @@ QDir &QDir::operator=(const QDir &dir)
 */
 QDir &QDir::operator=(const QString &path)
 {
-    Q_D(QDir);
-
-    d->setPath(path);
+    d_ptr->setPath(path);
     return *this;
 }
 
@@ -1705,14 +1652,10 @@ bool QDir::remove(const QString &fileName)
 */
 bool QDir::rename(const QString &oldName, const QString &newName)
 {
-    Q_D(QDir);
-
     if (oldName.isEmpty() || newName.isEmpty()) {
         qWarning("QDir::rename: Empty or null file name(s)");
         return false;
     }
-    if (!d->data->fileEngine)
-        return false;
 
     QFile file(filePath(oldName));
     if (!file.exists())
@@ -2150,9 +2093,9 @@ bool QDir::isRelativePath(const QString &path)
 */
 void QDir::refresh() const
 {
-    Q_D(const QDir);
-
-    const_cast<QDirPrivate *>(d)->reset();
+    QDirPrivate *d = const_cast<QDir*>(this)->d_ptr.data();
+    d->initFileEngine();
+    d->clearFileLists();
 }
 
 /*!
@@ -2228,7 +2171,7 @@ QStringList QDir::nameFiltersFromString(const QString &nameFilter)
 */
 bool QDir::matchAllDirs() const
 {
-    Q_D(const QDir);
+    const QDirPrivate* d = d_ptr.constData();
     return d->matchAllDirs;
 }
 
@@ -2240,9 +2183,10 @@ bool QDir::matchAllDirs() const
 */
 void QDir::setMatchAllDirs(bool on)
 {
-    Q_D(QDir);
+    QDirPrivate* d = d_ptr.data();
+    d->initFileEngine();
+    d->clearFileLists();
 
-    d->reset();
     d->matchAllDirs = on;
 }
 
@@ -2251,8 +2195,7 @@ void QDir::setMatchAllDirs(bool on)
 */
 QString QDir::nameFilter() const
 {
-    Q_D(const QDir);
-
+    const QDirPrivate* d = d_ptr.constData();
     return nameFilters().join(QString(d->filterSepChar));
 }
 
@@ -2278,10 +2221,12 @@ QString QDir::nameFilter() const
 */
 void QDir::setNameFilter(const QString &nameFilter)
 {
-    Q_D(QDir);
+    QDirPrivate* d = d_ptr.data();
+    d->initFileEngine();
+    d->clearFileLists();
 
     d->filterSepChar = QDirPrivate::getFilterSepChar(nameFilter);
-    setNameFilters(QDirPrivate::splitFilters(nameFilter, d->filterSepChar));
+    d->nameFilters = QDirPrivate::splitFilters(nameFilter, d->filterSepChar);
 }
 
 /*!
diff --git a/src/corelib/io/qdir.h b/src/corelib/io/qdir.h
index 28da271..7e5fbac 100644
--- a/src/corelib/io/qdir.h
+++ b/src/corelib/io/qdir.h
@@ -45,7 +45,7 @@
 #include <QtCore/qstring.h>
 #include <QtCore/qfileinfo.h>
 #include <QtCore/qstringlist.h>
-#include <QtCore/qscopedpointer.h>
+#include <QtCore/qshareddata.h>
 
 QT_BEGIN_HEADER
 
@@ -58,9 +58,8 @@ class QDirPrivate;
 class Q_CORE_EXPORT QDir
 {
 protected:
-    QScopedPointer<QDirPrivate> d_ptr;
-private:
-    Q_DECLARE_PRIVATE(QDir)
+    QSharedDataPointer<QDirPrivate> d_ptr;
+
 public:
     enum Filter { Dirs        = 0x001,
                   Files       = 0x002,
diff --git a/src/corelib/io/qfileinfo.cpp b/src/corelib/io/qfileinfo.cpp
index 61f7180..7eca212 100644
--- a/src/corelib/io/qfileinfo.cpp
+++ b/src/corelib/io/qfileinfo.cpp
@@ -47,59 +47,27 @@
 
 QT_BEGIN_NAMESPACE
 
-QFileInfoPrivate::QFileInfoPrivate(const QFileInfo *copy)
-{
-    if (copy) {
-        copy->d_func()->data->ref.ref();
-        data = copy->d_func()->data;
-    } else {
-        data = new QFileInfoPrivate::Data;
-    }
-}
-
-QFileInfoPrivate::~QFileInfoPrivate()
-{
-    if (!data->ref.deref())
-        delete data;
-    data = 0;
-}
-
-void QFileInfoPrivate::initFileEngine(const QString &file)
-{
-    detach();
-    delete data->fileEngine;
-    data->fileEngine = 0;
-    data->clear();
-    data->fileEngine = QAbstractFileEngine::create(file);
-    data->fileName = file;
-}
-
-void QFileInfoPrivate::detach()
-{
-    qAtomicDetach(data);
-}
-
 QString QFileInfoPrivate::getFileName(QAbstractFileEngine::FileName name) const
 {
-    if (data->cache_enabled && !data->fileNames[(int)name].isNull())
-        return data->fileNames[(int)name];
-    QString ret = data->fileEngine->fileName(name);
+    if (cache_enabled && !fileNames[(int)name].isNull())
+        return fileNames[(int)name];
+    QString ret = fileEngine->fileName(name);
     if (ret.isNull())
         ret = QLatin1String("");
-    if (data->cache_enabled)
-        data->fileNames[(int)name] = ret;
+    if (cache_enabled)
+        fileNames[(int)name] = ret;
     return ret;
 }
 
 QString QFileInfoPrivate::getFileOwner(QAbstractFileEngine::FileOwner own) const
 {
-    if (data->cache_enabled && !data->fileOwners[(int)own].isNull())
-        return data->fileOwners[(int)own];
-    QString ret = data->fileEngine->owner(own);
+    if (cache_enabled && !fileOwners[(int)own].isNull())
+        return fileOwners[(int)own];
+    QString ret = fileEngine->owner(own);
     if (ret.isNull())
         ret = QLatin1String("");
-    if (data->cache_enabled)
-        data->fileOwners[(int)own] = ret;
+    if (cache_enabled)
+        fileOwners[(int)own] = ret;
     return ret;
 }
 
@@ -118,7 +86,7 @@ uint QFileInfoPrivate::getFileFlags(QAbstractFileEngine::FileFlags request) cons
     uint cachedFlags = 0;
 
     if (request & (QAbstractFileEngine::FlagsMask | QAbstractFileEngine::TypesMask)) {
-        if (!data->getCachedFlag(CachedFileFlags)) {
+        if (!getCachedFlag(CachedFileFlags)) {
             req |= QAbstractFileEngine::FlagsMask;
             req |= QAbstractFileEngine::TypesMask;
             req &= (~QAbstractFileEngine::LinkType);
@@ -128,14 +96,14 @@ uint QFileInfoPrivate::getFileFlags(QAbstractFileEngine::FileFlags request) cons
         }
 
         if (request & QAbstractFileEngine::LinkType) {
-            if (!data->getCachedFlag(CachedLinkTypeFlag)) {
+            if (!getCachedFlag(CachedLinkTypeFlag)) {
                 req |= QAbstractFileEngine::LinkType;
                 cachedFlags |= CachedLinkTypeFlag;
             }
         }
 
         if (request & QAbstractFileEngine::BundleType) {
-            if (!data->getCachedFlag(CachedBundleTypeFlag)) {
+            if (!getCachedFlag(CachedBundleTypeFlag)) {
                 req |= QAbstractFileEngine::BundleType;
                 cachedFlags |= CachedBundleTypeFlag;
             }
@@ -143,30 +111,30 @@ uint QFileInfoPrivate::getFileFlags(QAbstractFileEngine::FileFlags request) cons
     }
 
     if (request & QAbstractFileEngine::PermsMask) {
-        if (!data->getCachedFlag(CachedPerms)) {
+        if (!getCachedFlag(CachedPerms)) {
             req |= QAbstractFileEngine::PermsMask;
             cachedFlags |= CachedPerms;
         }
     }
 
     if (req) {
-        if (data->cache_enabled)
+        if (cache_enabled)
             req &= (~QAbstractFileEngine::Refresh);
         else
             req |= QAbstractFileEngine::Refresh;
 
-        QAbstractFileEngine::FileFlags flags = data->fileEngine->fileFlags(req);
-        data->fileFlags |= uint(flags);
-        data->setCachedFlag(cachedFlags);
+        QAbstractFileEngine::FileFlags flags = fileEngine->fileFlags(req);
+        fileFlags |= uint(flags);
+        setCachedFlag(cachedFlags);
     }
 
-    return data->fileFlags & request;
+    return fileFlags & request;
 }
 
 QDateTime &QFileInfoPrivate::getFileTime(QAbstractFileEngine::FileTime request) const
 {
-    if (!data->cache_enabled)
-        data->clearFlags();
+    if (!cache_enabled)
+        clearFlags();
     uint cf;
     if (request == QAbstractFileEngine::CreationTime)
         cf = CachedCTime;
@@ -174,11 +142,11 @@ QDateTime &QFileInfoPrivate::getFileTime(QAbstractFileEngine::FileTime request)
         cf = CachedMTime;
     else
         cf = CachedATime;
-    if (!data->getCachedFlag(cf)) {
-        data->fileTimes[request] = data->fileEngine->fileTime(request);
-        data->setCachedFlag(cf);
+    if (!getCachedFlag(cf)) {
+        fileTimes[request] = fileEngine->fileTime(request);
+        setCachedFlag(cf);
     }
-    return data->fileTimes[request];
+    return fileTimes[request];
 }
 
 //************* QFileInfo
@@ -285,9 +253,8 @@ QFileInfo::QFileInfo() : d_ptr(new QFileInfoPrivate())
 
     \sa setFile(), isRelative(), QDir::setCurrent(), QDir::isRelativePath()
 */
-QFileInfo::QFileInfo(const QString &file) : d_ptr(new QFileInfoPrivate())
+QFileInfo::QFileInfo(const QString &file) : d_ptr(new QFileInfoPrivate(file))
 {
-    d_ptr->initFileEngine(file);
 }
 
 /*!
@@ -299,9 +266,8 @@ QFileInfo::QFileInfo(const QString &file) : d_ptr(new QFileInfoPrivate())
 
     \sa isRelative()
 */
-QFileInfo::QFileInfo(const QFile &file) : d_ptr(new QFileInfoPrivate())
+QFileInfo::QFileInfo(const QFile &file) : d_ptr(new QFileInfoPrivate(file.fileName()))
 {
-    d_ptr->initFileEngine(file.fileName());
 }
 
 /*!
@@ -316,15 +282,16 @@ QFileInfo::QFileInfo(const QFile &file) : d_ptr(new QFileInfoPrivate())
 
     \sa isRelative()
 */
-QFileInfo::QFileInfo(const QDir &dir, const QString &file) : d_ptr(new QFileInfoPrivate())
+QFileInfo::QFileInfo(const QDir &dir, const QString &file)
+    : d_ptr(new QFileInfoPrivate(dir.filePath(file)))
 {
-    d_ptr->initFileEngine(dir.filePath(file));
 }
 
 /*!
     Constructs a new QFileInfo that is a copy of the given \a fileinfo.
 */
-QFileInfo::QFileInfo(const QFileInfo &fileinfo) : d_ptr(new QFileInfoPrivate(&fileinfo))
+QFileInfo::QFileInfo(const QFileInfo &fileinfo)
+    : d_ptr(fileinfo.d_ptr)
 {
 
 }
@@ -359,17 +326,17 @@ bool QFileInfo::operator==(const QFileInfo &fileinfo) const
     Q_D(const QFileInfo);
     // ### Qt 5: understand long and short file names on Windows
     // ### (GetFullPathName()).
-    if (fileinfo.d_func()->data == d->data)
+    if (fileinfo.d_ptr == d_ptr)
         return true;
-    if (!d->data->fileEngine || !fileinfo.d_func()->data->fileEngine)
+    if (d->isDefaultConstructed || fileinfo.d_ptr->isDefaultConstructed)
         return false;
-    if (d->data->fileEngine->caseSensitive() != fileinfo.d_func()->data->fileEngine->caseSensitive())
+    if (d->fileEngine->caseSensitive() != fileinfo.d_ptr->fileEngine->caseSensitive())
         return false;
     if (fileinfo.size() == size()) { //if the size isn't the same...
         QString file1 = canonicalFilePath(),
                 file2 = fileinfo.canonicalFilePath();
         if (file1.length() == file2.length()) {
-            if (!fileinfo.d_func()->data->fileEngine->caseSensitive()) {
+            if (!fileinfo.d_ptr->fileEngine->caseSensitive()) {
                 for (int i = 0; i < file1.length(); i++) {
                     if (file1.at(i).toLower() != file2.at(i).toLower())
                         return false;
@@ -407,8 +374,7 @@ bool QFileInfo::operator==(const QFileInfo &fileinfo)
 */
 QFileInfo &QFileInfo::operator=(const QFileInfo &fileinfo)
 {
-    Q_D(QFileInfo);
-    qAtomicAssign(d->data, fileinfo.d_func()->data);
+    d_ptr = fileinfo.d_ptr;
     return *this;
 }
 
@@ -429,7 +395,9 @@ QFileInfo &QFileInfo::operator=(const QFileInfo &fileinfo)
 */
 void QFileInfo::setFile(const QString &file)
 {
+    bool caching = d_ptr.constData()->cache_enabled;
     *this = QFileInfo(file);
+    d_ptr->cache_enabled = caching;
 }
 
 /*!
@@ -445,7 +413,7 @@ void QFileInfo::setFile(const QString &file)
 */
 void QFileInfo::setFile(const QFile &file)
 {
-    *this = QFileInfo(file.fileName());
+    setFile(file.fileName());
 }
 
 /*!
@@ -461,7 +429,7 @@ void QFileInfo::setFile(const QFile &file)
 */
 void QFileInfo::setFile(const QDir &dir, const QString &file)
 {
-    *this = QFileInfo(dir.filePath(file));
+    setFile(dir.filePath(file));
 }
 
 /*!
@@ -488,7 +456,7 @@ void QFileInfo::setFile(const QDir &dir, const QString &file)
 QString QFileInfo::absoluteFilePath() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QLatin1String("");
     return d->getFileName(QAbstractFileEngine::AbsoluteName);
 }
@@ -505,7 +473,7 @@ QString QFileInfo::absoluteFilePath() const
 QString QFileInfo::canonicalFilePath() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QLatin1String("");
     return d->getFileName(QAbstractFileEngine::CanonicalName);
 }
@@ -532,9 +500,9 @@ QString QFileInfo::absolutePath() const
 {
     Q_D(const QFileInfo);
 
-    if (!d->data->fileEngine) {
+    if (d->isDefaultConstructed) {
         return QLatin1String("");
-    } else if (d->data->fileName.isEmpty()) {
+    } else if (d->fileName.isEmpty()) {
         qWarning("QFileInfo::absolutePath: Constructed with empty filename");
         return QLatin1String("");
     }
@@ -552,7 +520,7 @@ QString QFileInfo::absolutePath() const
 QString QFileInfo::canonicalPath() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QLatin1String("");
     return d->getFileName(QAbstractFileEngine::CanonicalPathName);
 }
@@ -569,7 +537,7 @@ QString QFileInfo::canonicalPath() const
 QString QFileInfo::path() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QLatin1String("");
     return d->getFileName(QAbstractFileEngine::PathName);
 }
@@ -593,9 +561,9 @@ QString QFileInfo::path() const
 bool QFileInfo::isRelative() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return true;
-    return d->data->fileEngine->isRelativePath();
+    return d->fileEngine->isRelativePath();
 }
 
 /*!
@@ -607,11 +575,13 @@ bool QFileInfo::isRelative() const
 */
 bool QFileInfo::makeAbsolute()
 {
-    Q_D(QFileInfo);
-    if (!d->data->fileEngine || !d->data->fileEngine->isRelativePath())
+    if (d_ptr.constData()->isDefaultConstructed
+            || !d_ptr.constData()->fileEngine->isRelativePath())
         return false;
-    QString absFileName = d->getFileName(QAbstractFileEngine::AbsoluteName);
-    d->initFileEngine(absFileName);
+    QString absFileName = d_ptr.constData()->getFileName(QAbstractFileEngine::AbsoluteName);
+    // QSharedDataPointer::operator->() will detach.
+
+    setFile(absFileName);
     return true;
 }
 
@@ -624,7 +594,7 @@ bool QFileInfo::makeAbsolute()
 bool QFileInfo::exists() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return false;
     return d->getFileFlags(QAbstractFileEngine::ExistsFlag);
 }
@@ -639,7 +609,7 @@ bool QFileInfo::exists() const
 void QFileInfo::refresh()
 {
     Q_D(QFileInfo);
-    d->reset();
+    d->clear();
 }
 
 /*!
@@ -651,7 +621,7 @@ void QFileInfo::refresh()
 QString QFileInfo::filePath() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QLatin1String("");
     return d->getFileName(QAbstractFileEngine::DefaultName);
 }
@@ -670,7 +640,7 @@ QString QFileInfo::filePath() const
 QString QFileInfo::fileName() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QLatin1String("");
     return d->getFileName(QAbstractFileEngine::BaseName);
 }
@@ -690,7 +660,7 @@ QString QFileInfo::fileName() const
 QString QFileInfo::bundleName() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QLatin1String("");
     return d->getFileName(QAbstractFileEngine::BundleName);
 }
@@ -714,7 +684,7 @@ QString QFileInfo::bundleName() const
 QString QFileInfo::baseName() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QLatin1String("");
     return d->getFileName(QAbstractFileEngine::BaseName).section(QLatin1Char('.'), 0, 0);
 }
@@ -733,7 +703,7 @@ QString QFileInfo::baseName() const
 QString QFileInfo::completeBaseName() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QLatin1String("");
     QString name = d->getFileName(QAbstractFileEngine::BaseName);
     int index = name.lastIndexOf(QLatin1Char('.'));
@@ -754,7 +724,7 @@ QString QFileInfo::completeBaseName() const
 QString QFileInfo::completeSuffix() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QLatin1String("");
     QString fileName = d->getFileName(QAbstractFileEngine::BaseName);
     int firstDot = fileName.indexOf(QLatin1Char('.'));
@@ -781,7 +751,7 @@ QString QFileInfo::completeSuffix() const
 QString QFileInfo::suffix() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QLatin1String("");
     QString fileName = d->getFileName(QAbstractFileEngine::BaseName);
     int lastDot = fileName.lastIndexOf(QLatin1Char('.'));
@@ -846,7 +816,7 @@ QDir QFileInfo::dir(bool absPath) const
 bool QFileInfo::isReadable() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return false;
     return d->getFileFlags(QAbstractFileEngine::ReadUserPerm);
 }
@@ -859,7 +829,7 @@ bool QFileInfo::isReadable() const
 bool QFileInfo::isWritable() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return false;
     return d->getFileFlags(QAbstractFileEngine::WriteUserPerm);
 }
@@ -872,7 +842,7 @@ bool QFileInfo::isWritable() const
 bool QFileInfo::isExecutable() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return false;
     return d->getFileFlags(QAbstractFileEngine::ExeUserPerm);
 }
@@ -886,7 +856,7 @@ bool QFileInfo::isExecutable() const
 bool QFileInfo::isHidden() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return false;
     return d->getFileFlags(QAbstractFileEngine::HiddenFlag);
 }
@@ -901,7 +871,7 @@ bool QFileInfo::isHidden() const
 bool QFileInfo::isFile() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return false;
     return d->getFileFlags(QAbstractFileEngine::FileType);
 }
@@ -915,7 +885,7 @@ bool QFileInfo::isFile() const
 bool QFileInfo::isDir() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return false;
     return d->getFileFlags(QAbstractFileEngine::DirectoryType);
 }
@@ -931,7 +901,7 @@ bool QFileInfo::isDir() const
 bool QFileInfo::isBundle() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return false;
     return d->getFileFlags(QAbstractFileEngine::BundleType);
 }
@@ -956,7 +926,7 @@ bool QFileInfo::isBundle() const
 bool QFileInfo::isSymLink() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return false;
     return d->getFileFlags(QAbstractFileEngine::LinkType);
 }
@@ -969,7 +939,7 @@ bool QFileInfo::isSymLink() const
 bool QFileInfo::isRoot() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return true;
     return d->getFileFlags(QAbstractFileEngine::RootFlag);
 }
@@ -997,7 +967,7 @@ bool QFileInfo::isRoot() const
 QString QFileInfo::readLink() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QLatin1String("");
     return d->getFileName(QAbstractFileEngine::LinkName);
 }
@@ -1015,7 +985,7 @@ QString QFileInfo::readLink() const
 QString QFileInfo::owner() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QLatin1String("");
     return d->getFileOwner(QAbstractFileEngine::OwnerUser);
 }
@@ -1031,9 +1001,9 @@ QString QFileInfo::owner() const
 uint QFileInfo::ownerId() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return 0;
-    return d->data->fileEngine->ownerId(QAbstractFileEngine::OwnerUser);
+    return d->fileEngine->ownerId(QAbstractFileEngine::OwnerUser);
 }
 
 /*!
@@ -1049,7 +1019,7 @@ uint QFileInfo::ownerId() const
 QString QFileInfo::group() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QLatin1String("");
     return d->getFileOwner(QAbstractFileEngine::OwnerGroup);
 }
@@ -1065,9 +1035,9 @@ QString QFileInfo::group() const
 uint QFileInfo::groupId() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return 0;
-    return d->data->fileEngine->ownerId(QAbstractFileEngine::OwnerGroup);
+    return d->fileEngine->ownerId(QAbstractFileEngine::OwnerGroup);
 }
 
 /*!
@@ -1086,7 +1056,7 @@ uint QFileInfo::groupId() const
 bool QFileInfo::permission(QFile::Permissions permissions) const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return false;
     return d->getFileFlags(QAbstractFileEngine::FileFlags((int)permissions)) == (uint)permissions;
 }
@@ -1098,7 +1068,7 @@ bool QFileInfo::permission(QFile::Permissions permissions) const
 QFile::Permissions QFileInfo::permissions() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return 0;
     return QFile::Permissions(d->getFileFlags(QAbstractFileEngine::PermsMask) & QAbstractFileEngine::PermsMask);
 }
@@ -1113,13 +1083,13 @@ QFile::Permissions QFileInfo::permissions() const
 qint64 QFileInfo::size() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return 0;
-    if (!d->data->getCachedFlag(QFileInfoPrivate::CachedSize)) {
-        d->data->setCachedFlag(QFileInfoPrivate::CachedSize);
-        d->data->fileSize = d->data->fileEngine->size();
+    if (!d->getCachedFlag(QFileInfoPrivate::CachedSize)) {
+        d->setCachedFlag(QFileInfoPrivate::CachedSize);
+        d->fileSize = d->fileEngine->size();
     }
-    return d->data->fileSize;
+    return d->fileSize;
 }
 
 /*!
@@ -1138,7 +1108,7 @@ qint64 QFileInfo::size() const
 QDateTime QFileInfo::created() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QDateTime();
     return d->getFileTime(QAbstractFileEngine::CreationTime);
 }
@@ -1151,7 +1121,7 @@ QDateTime QFileInfo::created() const
 QDateTime QFileInfo::lastModified() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QDateTime();
     return d->getFileTime(QAbstractFileEngine::ModificationTime);
 }
@@ -1167,7 +1137,7 @@ QDateTime QFileInfo::lastModified() const
 QDateTime QFileInfo::lastRead() const
 {
     Q_D(const QFileInfo);
-    if (!d->data->fileEngine)
+    if (d->isDefaultConstructed)
         return QDateTime();
     return d->getFileTime(QAbstractFileEngine::AccessTime);
 }
@@ -1177,8 +1147,7 @@ QDateTime QFileInfo::lastRead() const
 */
 void QFileInfo::detach()
 {
-    Q_D(QFileInfo);
-    d->detach();
+    d_ptr.detach();
 }
 
 /*!
@@ -1189,7 +1158,7 @@ void QFileInfo::detach()
 bool QFileInfo::caching() const
 {
     Q_D(const QFileInfo);
-    return d->data->cache_enabled;
+    return d->cache_enabled;
 }
 
 /*!
@@ -1207,8 +1176,7 @@ bool QFileInfo::caching() const
 void QFileInfo::setCaching(bool enable)
 {
     Q_D(QFileInfo);
-    detach();
-    d->data->cache_enabled = enable;
+    d->cache_enabled = enable;
 }
 
 /*!
diff --git a/src/corelib/io/qfileinfo.h b/src/corelib/io/qfileinfo.h
index 7e82aed..f0128b1 100644
--- a/src/corelib/io/qfileinfo.h
+++ b/src/corelib/io/qfileinfo.h
@@ -44,7 +44,7 @@
 
 #include <QtCore/qfile.h>
 #include <QtCore/qlist.h>
-#include <QtCore/qscopedpointer.h>
+#include <QtCore/qshareddata.h>
 
 QT_BEGIN_HEADER
 
@@ -166,10 +166,20 @@ public:
 #endif
 
 protected:
-    QScopedPointer<QFileInfoPrivate> d_ptr;
+    QSharedDataPointer<QFileInfoPrivate> d_ptr;
 private:
-    Q_DECLARE_PRIVATE(QFileInfo)
+    inline QFileInfoPrivate* d_func()
+    {
+        detach();
+        return const_cast<QFileInfoPrivate *>(d_ptr.constData());
+    }
+
+    inline const QFileInfoPrivate* d_func() const
+    {
+        return d_ptr.constData();
+    }
 };
+
 Q_DECLARE_TYPEINFO(QFileInfo, Q_MOVABLE_TYPE);
 
 #ifdef QT3_SUPPORT
diff --git a/src/corelib/io/qfileinfo_p.h b/src/corelib/io/qfileinfo_p.h
index 306ffe1..b9b1092 100644
--- a/src/corelib/io/qfileinfo_p.h
+++ b/src/corelib/io/qfileinfo_p.h
@@ -57,71 +57,83 @@
 #include "qabstractfileengine.h"
 #include "qdatetime.h"
 #include "qatomic.h"
+#include "qshareddata.h"
 
 QT_BEGIN_NAMESPACE
 
-class QFileInfoPrivate
+class QFileInfoPrivate : public QSharedData
 {
 public:
-    QFileInfoPrivate(const QFileInfo *copy=0);
-    ~QFileInfoPrivate();
 
-    void initFileEngine(const QString &);
+    enum { CachedFileFlags=0x01, CachedLinkTypeFlag=0x02, CachedBundleTypeFlag=0x04,
+           CachedMTime=0x10, CachedCTime=0x20, CachedATime=0x40,
+           CachedSize =0x08, CachedPerms=0x80 };
+
+    inline QFileInfoPrivate()
+        : QSharedData(), fileEngine(0),
+        cachedFlags(0),
+        isDefaultConstructed(true),
+        cache_enabled(true), fileFlags(0), fileSize(0)
+    {}
+    inline QFileInfoPrivate(const QFileInfoPrivate &copy)
+        : QSharedData(copy), fileEngine(QAbstractFileEngine::create(copy.fileName)),
+        fileName(copy.fileName),
+        cachedFlags(0),
+#ifndef QT_NO_FSFILEENGINE
+        isDefaultConstructed(false),
+#else
+        isDefaultConstructed(!fileEngine),
+#endif
+        cache_enabled(copy.cache_enabled), fileFlags(0), fileSize(0)
+    {}
+    inline QFileInfoPrivate(const QString &file)
+        : QSharedData(), fileEngine(QAbstractFileEngine::create(file)),
+        fileName(file),
+        cachedFlags(0),
+#ifndef QT_NO_FSFILEENGINE
+        isDefaultConstructed(false),
+#else
+        isDefaultConstructed(!fileEngine),
+#endif
+        cache_enabled(true), fileFlags(0), fileSize(0)
+    {
+    }
+
+    inline void clearFlags() const {
+        fileFlags = 0;
+        cachedFlags = 0;
+        if (fileEngine)
+            (void)fileEngine->fileFlags(QAbstractFileEngine::Refresh);
+    }
+    inline void clear() {
+        clearFlags();
+        for (int i = QAbstractFileEngine::NFileNames - 1 ; i >= 0 ; --i)
+            fileNames[i].clear();
+        fileOwners[1].clear();
+        fileOwners[0].clear();
+    }
 
     uint getFileFlags(QAbstractFileEngine::FileFlags) const;
     QDateTime &getFileTime(QAbstractFileEngine::FileTime) const;
     QString getFileName(QAbstractFileEngine::FileName) const;
     QString getFileOwner(QAbstractFileEngine::FileOwner own) const;
 
-    enum { CachedFileFlags=0x01, CachedLinkTypeFlag=0x02, CachedBundleTypeFlag=0x04,
-           CachedMTime=0x10, CachedCTime=0x20, CachedATime=0x40,
-           CachedSize =0x08, CachedPerms=0x80 };
-    struct Data {
-        inline Data()
-            : ref(1), fileEngine(0),
-              cachedFlags(0), cache_enabled(1), fileFlags(0), fileSize(0)
-        {}
-        inline Data(const Data &copy)
-            : ref(1), fileEngine(QAbstractFileEngine::create(copy.fileName)),
-              fileName(copy.fileName),
-              cachedFlags(0), cache_enabled(copy.cache_enabled), fileFlags(0), fileSize(0)
-        {}
-        inline ~Data() { delete fileEngine; }
-        inline void clearFlags() {
-            fileFlags = 0;
-            cachedFlags = 0;
-            if (fileEngine)
-                (void)fileEngine->fileFlags(QAbstractFileEngine::Refresh);
-        }
-        inline void clear() {
-            clearFlags();
-            for (int i = QAbstractFileEngine::NFileNames - 1 ; i >= 0 ; --i)
-                fileNames[i].clear();
-            fileOwners[1].clear();
-            fileOwners[0].clear();
-        }
-        mutable QAtomicInt ref;
+    QScopedPointer<QAbstractFileEngine> const fileEngine;
 
-        QAbstractFileEngine *fileEngine;
-        mutable QString fileName;
-        mutable QString fileNames[QAbstractFileEngine::NFileNames];
-        mutable QString fileOwners[2];
+    mutable QString fileName;
+    mutable QString fileNames[QAbstractFileEngine::NFileNames];
+    mutable QString fileOwners[2];
 
-        mutable uint cachedFlags : 31;
-        mutable uint cache_enabled : 1;
-        mutable uint fileFlags;
-        mutable qint64 fileSize;
-        mutable QDateTime fileTimes[3];
-        inline bool getCachedFlag(uint c) const
-        { return cache_enabled ? (cachedFlags & c) : 0; }
-        inline void setCachedFlag(uint c)
-        { if (cache_enabled) cachedFlags |= c; }
-    } *data;
-    inline void reset() {
-        detach();
-        data->clear();
-    }
-    void detach();
+    mutable uint cachedFlags : 30;
+    bool const isDefaultConstructed : 1; // QFileInfo is a default constructed instance
+    bool cache_enabled : 1;
+    mutable uint fileFlags;
+    mutable qint64 fileSize;
+    mutable QDateTime fileTimes[3];
+    inline bool getCachedFlag(uint c) const
+    { return cache_enabled ? (cachedFlags & c) : 0; }
+    inline void setCachedFlag(uint c) const
+    { if (cache_enabled) cachedFlags |= c; }
 };
 
 QT_END_NAMESPACE
diff --git a/src/tools/rcc/rcc.cpp b/src/tools/rcc/rcc.cpp
index 1f6e58f..0e3167d 100644
--- a/src/tools/rcc/rcc.cpp
+++ b/src/tools/rcc/rcc.cpp
@@ -544,8 +544,11 @@ bool RCCResourceLibrary::addFile(const QString &alias, const RCCFileInfo &file)
     const QString filename = nodes.at(nodes.size()-1);
     RCCFileInfo *s = new RCCFileInfo(file);
     s->m_parent = parent;
-    if (parent->m_children.contains(filename))
-        qWarning("potential duplicate alias detected: '%s'", qPrintable(filename));
+    if (parent->m_children.contains(filename)) {
+        foreach (const QString &fileName, m_fileNames)
+            qWarning("%s: Warning: potential duplicate alias detected: '%s'",
+                     qPrintable(fileName), qPrintable(filename));
+        }
     parent->m_children.insertMulti(filename, s);
     return true;
 }
diff --git a/src/tools/uic/cpp/cppextractimages.cpp b/src/tools/uic/cpp/cppextractimages.cpp
index 52c1b9d..5809724 100644
--- a/src/tools/uic/cpp/cppextractimages.cpp
+++ b/src/tools/uic/cpp/cppextractimages.cpp
@@ -76,14 +76,14 @@ void ExtractImages::acceptUI(DomUI *node)
     if (m_option.qrcOutputFile.size()) {
         f.setFileName(m_option.qrcOutputFile);
         if (!f.open(QIODevice::WriteOnly | QFile::Text)) {
-            fprintf(stderr, "Could not create resource file\n");
+            fprintf(stderr, "%s: Error: Could not create resource file\n", qPrintable(m_option.messagePrefix()));
             return;
         }
 
         QFileInfo fi(m_option.qrcOutputFile);
         QDir dir = fi.absoluteDir();
         if (!dir.exists(QLatin1String("images")) && !dir.mkdir(QLatin1String("images"))) {
-            fprintf(stderr, "Could not create image dir\n");
+            fprintf(stderr, "%s: Error: Could not create image dir\n", qPrintable(m_option.messagePrefix()));
             return;
         }
         dir.cd(QLatin1String("images"));
@@ -126,7 +126,9 @@ void ExtractImages::acceptImage(DomImage *image)
     if (isXPM_GZ)
         openMode |= QIODevice::Text;
     if (!f.open(openMode)) {
-        fprintf(stderr, "Could not create image file %s: %s", qPrintable(fname), qPrintable(f.errorString()));
+        fprintf(stderr, "%s: Error: Could not create image file %s: %s",
+                qPrintable(m_option.messagePrefix()),
+                qPrintable(fname), qPrintable(f.errorString()));
         return;
     }
 
diff --git a/src/tools/uic/cpp/cppwriteincludes.cpp b/src/tools/uic/cpp/cppwriteincludes.cpp
index 4e0ee4a..7b9d03a 100644
--- a/src/tools/uic/cpp/cppwriteincludes.cpp
+++ b/src/tools/uic/cpp/cppwriteincludes.cpp
@@ -126,8 +126,9 @@ void WriteIncludes::acceptUI(DomUI *node)
 
     if (m_uic->hasExternalPixmap() && m_uic->pixmapFunction() == QLatin1String("qPixmapFromMimeSource")) {
 #ifdef QT_NO_QT3_SUPPORT
-        qWarning("Warning: The form file has external pixmaps or qPixmapFromMimeSource() set as a pixmap function. "
-                 "This requires Qt 3 support, which is disabled. The resulting code will not compile.");
+        qWarning("%s: Warning: The form file has external pixmaps or qPixmapFromMimeSource() set as a pixmap function. "
+                 "This requires Qt 3 support, which is disabled. The resulting code will not compile.",
+                 qPrintable(m_uic->option().messagePrefix()));
 #endif
         add(QLatin1String("Q3MimeSourceFactory"));
     }
@@ -212,8 +213,9 @@ void WriteIncludes::insertIncludeForClass(const QString &className, QString head
         header = lowerClassName;
         header += QLatin1String(".h");
         if (warnHeaderGeneration) {
-            qWarning("Warning: generated header '%s' for class '%s'.", qPrintable(header),
-                     qPrintable(className));
+            qWarning("%s: Warning: generated header '%s' for class '%s'.",
+                     qPrintable(m_uic->option().messagePrefix()),
+                     qPrintable(header), qPrintable(className));
 
         }
 
diff --git a/src/tools/uic/cpp/cppwriteinitialization.cpp b/src/tools/uic/cpp/cppwriteinitialization.cpp
index dc1d181..b06eb7a 100644
--- a/src/tools/uic/cpp/cppwriteinitialization.cpp
+++ b/src/tools/uic/cpp/cppwriteinitialization.cpp
@@ -155,7 +155,7 @@ namespace {
             if (const DomResourceIcon *dri = p->elementIconSet()) {
                 if (!isIconFormat44(dri)) {
                     if (dri->text().isEmpty())  {
-                        const QString msg = QString::fromUtf8("%1: An invalid icon property '%2' was encountered.").arg(fileName).arg(p->attributeName());
+                        const QString msg = QString::fromUtf8("%1: Warning: An invalid icon property '%2' was encountered.").arg(fileName).arg(p->attributeName());
                         qWarning("%s", qPrintable(msg));
                         return false;
                     }
@@ -165,7 +165,7 @@ namespace {
         case DomProperty::Pixmap:
             if (const DomResourcePixmap *drp = p->elementPixmap())
                 if (drp->text().isEmpty()) {
-                    const QString msg = QString::fromUtf8("%1: An invalid pixmap property '%2' was encountered.").arg(fileName).arg(p->attributeName());
+                    const QString msg = QString::fromUtf8("%1: Warning: An invalid pixmap property '%2' was encountered.").arg(fileName).arg(p->attributeName());
                     qWarning("%s", qPrintable(msg));
                     return false;
                 }
@@ -539,10 +539,14 @@ void WriteInitialization::acceptUI(DomUI *node)
         const Buddy &b = m_buddies.at(i);
 
         if (!m_registeredWidgets.contains(b.objName)) {
-            fprintf(stderr, "'%s' isn't a valid widget\n", b.objName.toLatin1().data());
+            fprintf(stderr, "%s: Warning: Buddy assignment: '%s' is not a valid widget.\n",
+                    qPrintable(m_option.messagePrefix()),
+                    b.objName.toLatin1().data());
             continue;
         } else if (!m_registeredWidgets.contains(b.buddy)) {
-            fprintf(stderr, "'%s' isn't a valid widget\n", b.buddy.toLatin1().data());
+            fprintf(stderr, "%s: Warning: Buddy assignment: '%s' is not a valid widget.\n",
+                    qPrintable(m_option.messagePrefix()),
+                    b.buddy.toLatin1().data());
             continue;
         }
 
@@ -867,7 +871,9 @@ void WriteInitialization::acceptWidget(DomWidget *node)
         const QString name = zOrder.at(i);
 
         if (!m_registeredWidgets.contains(name)) {
-            fprintf(stderr, "'%s' isn't a valid widget\n", name.toLatin1().data());
+            fprintf(stderr, "%s: Warning: Z-order assignment: '%s' is not a valid widget.\n",
+                    qPrintable(m_option.messagePrefix()),
+                    name.toLatin1().data());
             continue;
         }
 
@@ -895,7 +901,9 @@ void WriteInitialization::addButtonGroup(const DomWidget *buttonNode, const QStr
         DomButtonGroup *newGroup = new DomButtonGroup;
         newGroup->setAttributeName(attributeName);
         group = newGroup;
-        fprintf(stderr, "Warning: Creating button group `%s'\n", attributeName.toLatin1().data());
+        fprintf(stderr, "%s: Warning: Creating button group `%s'\n",
+                qPrintable(m_option.messagePrefix()),
+                attributeName.toLatin1().data());
     }
     const QString groupName = m_driver->findOrInsertButtonGroup(group);
     // Create on demand
@@ -1163,7 +1171,9 @@ void WriteInitialization::acceptActionRef(DomActionRef *node)
             return;
         }
     } else if (!(m_driver->actionByName(actionName) || isSeparator)) {
-        fprintf(stderr, "Warning: action `%s' not declared\n", actionName.toLatin1().data());
+        fprintf(stderr, "%s: Warning: action `%s' not declared\n",
+                qPrintable(m_option.messagePrefix()),
+                actionName.toLatin1().data());
         return;
     }
 
@@ -1853,7 +1863,9 @@ void WriteInitialization::acceptTabStops(DomTabStops *tabStops)
         const QString name = l.at(i);
 
         if (!m_registeredWidgets.contains(name)) {
-            fprintf(stderr, "'%s' isn't a valid widget\n", name.toLatin1().data());
+            fprintf(stderr, "%s: Warning: Tab-stop assignment: '%s' is not a valid widget.\n",
+                    qPrintable(m_option.messagePrefix()),
+                    name.toLatin1().data());
             continue;
         }
 
@@ -2083,7 +2095,8 @@ QString WriteInitialization::pixCall(const DomProperty *p) const
         s = p->elementPixmap()->text();
         break;
     default:
-        qWarning() << "Warning: Unknown icon format encountered. The ui-file was generated with a too-recent version of Designer.";
+        qWarning("%s: Warning: Unknown icon format encountered. The ui-file was generated with a too-recent version of Designer.",
+                 qPrintable(m_option.messagePrefix()));
         return QLatin1String("QIcon()");
         break;
     }
@@ -2573,7 +2586,7 @@ void WriteInitialization::initializeQ3SqlDataTable(DomWidget *w)
     }
 
     if (table.isEmpty() || connection.isEmpty()) {
-        fprintf(stderr, "invalid database connection\n");
+        fprintf(stderr, "%s: Warning: Invalid database connection\n", qPrintable(m_option.messagePrefix()));
         return;
     }
 
@@ -2613,7 +2626,7 @@ void WriteInitialization::initializeQ3SqlDataBrowser(DomWidget *w)
     }
 
     if (table.isEmpty() || connection.isEmpty()) {
-        fprintf(stderr, "invalid database connection\n");
+        fprintf(stderr, "%s: Warning: Invalid database connection\n", qPrintable(m_option.messagePrefix()));
         return;
     }
 
diff --git a/src/tools/uic/driver.cpp b/src/tools/uic/driver.cpp
index 676388f..65d63e0 100644
--- a/src/tools/uic/driver.cpp
+++ b/src/tools/uic/driver.cpp
@@ -178,7 +178,10 @@ QString Driver::unique(const QString &instanceName, const QString &className)
     }
 
     if (alreadyUsed && className.size()) {
-        fprintf(stderr, "Warning: name %s is already used\n", qPrintable(instanceName));
+        fprintf(stderr, "%s: Warning: The name '%s' (%s) is already in use, defaulting to '%s'.\n",
+                qPrintable(m_option.messagePrefix()),
+                qPrintable(instanceName), qPrintable(className),
+                qPrintable(name));
     }
 
     m_nameRepository.insert(name, true);
diff --git a/src/tools/uic/option.h b/src/tools/uic/option.h
index 8556728..011a8f8 100644
--- a/src/tools/uic/option.h
+++ b/src/tools/uic/option.h
@@ -43,6 +43,7 @@
 #define OPTION_H
 
 #include <QtCore/QString>
+#include <QtCore/QDir>
 
 QT_BEGIN_NAMESPACE
 
@@ -91,6 +92,13 @@ struct Option
           generator(CppGenerator),
           prefix(QLatin1String("Ui_"))
     { indent.fill(QLatin1Char(' '), 4); }
+
+    QString messagePrefix() const
+    {
+        return inputFile.isEmpty() ?
+               QString(QLatin1String("stdin")) :
+               QDir::toNativeSeparators(inputFile);
+    }
 };
 
 QT_END_NAMESPACE