QFile/QFileInfo: mark readLink() as deprecated

QFile/QFileInfo::readLink() functions are obsolete but were not marked
as deprecated.
Explicit mark them as deprecated so they can be removed with Qt6.

Change-Id: I52424dc5441e1f5b01015713df990bbec5186caa
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@qt.io>

qmake/library/qmakeevaluator.cpp

@@ -1190,7 +1190,7 @@ bool QMakeEvaluator::loadSpecInternal()
 #  ifdef Q_OS_UNIX
     if (m_qmakespec.endsWith(QLatin1String("/default-host"))
         || m_qmakespec.endsWith(QLatin1String("/default"))) {
-        QString rspec = QFileInfo(m_qmakespec).readLink();
+        QString rspec = QFileInfo(m_qmakespec).symLinkTarget();
         if (!rspec.isEmpty())
             m_qmakespec = QDir::cleanPath(QDir(m_qmakespec).absoluteFilePath(rspec));
     }

src/corelib/io/qfile.cpp

@@ -454,7 +454,13 @@ QFile::exists(const QString &fileName)
 
     \sa fileName(), setFileName()
 */
+QString QFile::symLinkTarget() const
+{
+    Q_D(const QFile);
+    return d->engine()->fileName(QAbstractFileEngine::LinkName);
+}
 
+#if QT_DEPRECATED_SINCE(5, 13)
 /*!
     \obsolete
 
@@ -463,9 +469,9 @@ QFile::exists(const QString &fileName)
 QString
 QFile::readLink() const
 {
-    Q_D(const QFile);
-    return d->engine()->fileName(QAbstractFileEngine::LinkName);
+    return symLinkTarget();
 }
+#endif
 
 /*!
     \fn static QString QFile::symLinkTarget(const QString &fileName)
@@ -478,7 +484,12 @@ QFile::readLink() const
     This name may not represent an existing file; it is only a string.
     QFile::exists() returns \c true if the symlink points to an existing file.
 */
+QString QFile::symLinkTarget(const QString &fileName)
+{
+    return QFileInfo(fileName).symLinkTarget();
+}
 
+#if QT_DEPRECATED_SINCE(5, 13)
 /*!
     \obsolete
 
@@ -487,8 +498,9 @@ QFile::readLink() const
 QString
 QFile::readLink(const QString &fileName)
 {
-    return QFileInfo(fileName).readLink();
+    return symLinkTarget(fileName);
 }
+#endif
 
 /*!
     Removes the file specified by fileName(). Returns \c true if successful;

src/corelib/io/qfile.h

@@ -107,10 +107,14 @@ public:
     bool exists() const;
     static bool exists(const QString &fileName);
 
+#if QT_DEPRECATED_SINCE(5, 13)
+    QT_DEPRECATED_X("Use QFile::symLinkTarget() instead")
     QString readLink() const;
+    QT_DEPRECATED_X("Use QFile::symLinkTarget(QString) instead")
     static QString readLink(const QString &fileName);
-    inline QString symLinkTarget() const { return readLink(); }
-    inline static QString symLinkTarget(const QString &fileName) { return readLink(fileName); }
+#endif
+    QString symLinkTarget() const;
+    static QString symLinkTarget(const QString &fileName);
 
     bool remove();
     static bool remove(const QString &fileName);

src/corelib/io/qfileinfo.cpp

@@ -1107,12 +1107,19 @@ bool QFileInfo::isRoot() const
     \sa exists(), isSymLink(), isDir(), isFile()
 */
 
+#if QT_DEPRECATED_SINCE(5, 13)
 /*!
     \obsolete
 
     Use symLinkTarget() instead.
 */
 QString QFileInfo::readLink() const
+{
+    return symLinkTarget();
+}
+#endif
+
+QString QFileInfo::symLinkTarget() const
 {
     Q_D(const QFileInfo);
     if (d->isDefaultConstructed)

src/corelib/io/qfileinfo.h

@@ -116,8 +116,11 @@ public:
     bool isRoot() const;
     bool isBundle() const;
 
+#if QT_DEPRECATED_SINCE(5, 13)
+    QT_DEPRECATED_X("Use QFileInfo::symLinkTarget() instead")
     QString readLink() const;
-    inline QString symLinkTarget() const { return readLink(); }
+#endif
+    QString symLinkTarget() const;
 
     QString owner() const;
     uint ownerId() const;

tests/auto/corelib/io/qfileinfo/tst_qfileinfo.cpp

@@ -2022,7 +2022,7 @@ static void stateCheck(const QFileInfo &info, const QString &dirname, const QStr
     QVERIFY(!info.isRoot());
     QCOMPARE(info.isNativePath(), !filename.isEmpty());
 
-    QCOMPARE(info.readLink(), QString());
+    QCOMPARE(info.symLinkTarget(), QString());
     QCOMPARE(info.ownerId(), uint(-2));
     QCOMPARE(info.groupId(), uint(-2));
     QCOMPARE(info.owner(), QString());

tests/auto/corelib/io/qtemporaryfile/tst_qtemporaryfile.cpp

@@ -376,7 +376,7 @@ void tst_QTemporaryFile::io()
     before.setSecsSinceEpoch(before.toSecsSinceEpoch());
 
     QVERIFY(file.open());
-    QVERIFY(file.readLink().isEmpty()); // it's not a link!
+    QVERIFY(file.symLinkTarget().isEmpty()); // it's not a link!
     QFile::Permissions perm = file.permissions();
     QVERIFY(perm & QFile::ReadOwner);
     QVERIFY(file.setPermissions(perm));

tests/benchmarks/corelib/io/qfileinfo/main.cpp

@@ -81,7 +81,7 @@ void qfileinfo::symLinkTargetPerformanceLNK()
     QString linkTarget;
     QBENCHMARK {
         for(int i=0; i<100; i++)
-            linkTarget = info.readLink();
+            linkTarget = info.symLinkTarget();
     }
     QVERIFY(QFile::remove("link.lnk"));
 }
@@ -104,7 +104,7 @@ void qfileinfo::symLinkTargetPerformanceMounpoint()
     QString linkTarget;
     QBENCHMARK {
         for(int i=0; i<100; i++)
-            linkTarget = info.readLink();
+            linkTarget = info.symLinkTarget();
     }
     QVERIFY(QDir().rmdir(mountpoint));
 }