Fix the qtpath issue with lto enabled

Move qtconfManualPath pointer to the unnamed namespace, so it's never
exported. Add the static setQtconfManualPath method that sets the
pointer at runtime.

Fixes: QTBUG-122739
Change-Id: Icfc631f9680ad5f484920b0fdf3e408b7657c108
Reviewed-by: Joerg Bornemann <[email protected]>
Reviewed-by: Thiago Macieira <[email protected]>
(cherry picked from commit bdb2f20154c1fa1f0962a46a22afdee453a2db1e)
Reviewed-by: Qt Cherry-pick Bot <[email protected]>
(cherry picked from commit a405320544a190fac3aaa0bfe8e842e4019e5386)
(cherry picked from commit dc118ad13f28b0721b1118fdbe43a3f5c33ac84a)

4 files changed, 14 insertions, 7 deletions

diff --git a/qmake/option.cpp b/qmake/option.cpp
index 09ae39fd3fd..3e8e677e70a 100644
--- a/qmake/option.cpp
+++ b/qmake/option.cpp
@@ -188,7 +188,7 @@ Option::parseCommandLine(QStringList &args, QMakeCmdLineParserState &state)
                 return Option::QMAKE_CMDLINE_SHOW_USAGE | Option::QMAKE_CMDLINE_ERROR;
             }
             if (!globals->qtconf.isEmpty())
-                QLibraryInfoPrivate::qtconfManualPath = &globals->qtconf;
+                QLibraryInfoPrivate::setQtconfManualPath(&globals->qtconf);
             if (cmdRet == QMakeGlobals::ArgumentsOk)
                 break;
             Q_ASSERT(cmdRet == QMakeGlobals::ArgumentUnknown);
diff --git a/src/corelib/global/qlibraryinfo.cpp b/src/corelib/global/qlibraryinfo.cpp
index fc23078381a..83e131d5912 100644
--- a/src/corelib/global/qlibraryinfo.cpp
+++ b/src/corelib/global/qlibraryinfo.cpp
@@ -87,10 +87,19 @@ void QLibrarySettings::load()
     }
 }
 
+namespace {
+const QString *qtconfManualPath = nullptr;
+}
+
+void QLibraryInfoPrivate::setQtconfManualPath(const QString *path)
+{
+    qtconfManualPath = path;
+}
+
 static QSettings *findConfiguration()
 {
-    if (QLibraryInfoPrivate::qtconfManualPath)
-        return new QSettings(*QLibraryInfoPrivate::qtconfManualPath, QSettings::IniFormat);
+    if (qtconfManualPath)
+        return new QSettings(*qtconfManualPath, QSettings::IniFormat);
 
     QString qtconfig = QStringLiteral(":/qt/etc/qt.conf");
     if (QFile::exists(qtconfig))
@@ -122,8 +131,6 @@ static QSettings *findConfiguration()
     return nullptr;     //no luck
 }
 
-const QString *QLibraryInfoPrivate::qtconfManualPath = nullptr;
-
 QSettings *QLibraryInfoPrivate::configuration()
 {
     QLibrarySettings *ls = qt_library_settings();
diff --git a/src/corelib/global/qlibraryinfo_p.h b/src/corelib/global/qlibraryinfo_p.h
index de1964509ca..9eac5959542 100644
--- a/src/corelib/global/qlibraryinfo_p.h
+++ b/src/corelib/global/qlibraryinfo_p.h
@@ -32,7 +32,7 @@ public:
 #if QT_CONFIG(settings)
     static QSettings *configuration();
     static void reload();
-    static const QString *qtconfManualPath;
+    static void setQtconfManualPath(const QString *qtconfManualPath);
 #endif
 
     struct LocationInfo
diff --git a/src/tools/qtpaths/qtpaths.cpp b/src/tools/qtpaths/qtpaths.cpp
index bc694bfcead..fad31ceafa5 100644
--- a/src/tools/qtpaths/qtpaths.cpp
+++ b/src/tools/qtpaths/qtpaths.cpp
@@ -222,7 +222,7 @@ int main(int argc, char **argv)
 #if QT_CONFIG(settings)
     if (parser.isSet(qtconf)) {
         qtconfManualPath = parser.value(qtconf);
-        QLibraryInfoPrivate::qtconfManualPath = &qtconfManualPath;
+        QLibraryInfoPrivate::setQtconfManualPath(&qtconfManualPath);
     }
 #endif