ProParser: Prefix mkspecs with remote roots

When needed.

Change-Id: Ibb159ce2513eb0d4023565dd11bc4c7dff5d0ec2
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/shared/proparser/qmakeevaluator.cpp

@@ -1480,8 +1480,9 @@ void QMakeEvaluator::updateMkspecPaths()
     if (!m_sourceRoot.isEmpty())
         ret << m_sourceRoot + concat;
 
-    ret << m_option->propertyValue(ProKey("QT_HOST_DATA/get")) + concat;
+    const QString root = m_option->deviceRoot();
-    ret << m_option->propertyValue(ProKey("QT_HOST_DATA/src")) + concat;
+    ret << root + m_option->propertyValue(ProKey("QT_HOST_DATA/get")) + concat;
+    ret << root + m_option->propertyValue(ProKey("QT_HOST_DATA/src")) + concat;
 
     ret.removeDuplicates();
     m_mkspecPaths = ret;

src/shared/proparser/qmakeglobals.cpp

@@ -225,6 +225,20 @@ void QMakeGlobals::setDirectories(const QString &input_dir, const QString &outpu
     }
 }
 
+QString QMakeGlobals::deviceRoot() const
+{
+    static const QString specialRoot = QDir::rootPath() + "__qtc_devices__/";
+    if (!build_root.startsWith(specialRoot))
+        return {};
+    int pos = build_root.indexOf('/', specialRoot.size());
+    if (pos == -1)
+        return {};
+    pos = build_root.indexOf('/', pos + 1);
+    if (pos == -1)
+        return {};
+    return build_root.left(pos + 1);
+}
+
 QString QMakeGlobals::shadowedPath(const QString &fileName) const
 {
     if (source_root.isEmpty())

src/shared/proparser/qmakeglobals.h

@@ -120,6 +120,7 @@ public:
     QString expandEnvVars(const QString &str) const;
     QString shadowedPath(const QString &fileName) const;
     QStringList splitPathList(const QString &value) const;
+    QString deviceRoot() const;
 
 private:
     QString getEnv(const QString &) const;