Move QEMU emulation detector to QTest

The emulation detection has been usable only on qtbase tests, move it to
QTest so that it can be used in other modules as well.

Pick-to: 6.1
Change-Id: I4b2321b7856414d7b1cfd5e6b1405a633c6bb878
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>

1 files changed, 134 insertions, 0 deletions

diff --git a/src/testlib/qemulationdetector_p.h b/src/testlib/qemulationdetector_p.h
new file mode 100644
index 0000000000..3ae3d07839
--- /dev/null
+++ b/src/testlib/qemulationdetector_p.h
@@ -0,0 +1,134 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtTest module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** 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 The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QEMULATIONDETECTOR_P_H
+#define QEMULATIONDETECTOR_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtCore/qglobal.h>
+
+#if defined(Q_OS_LINUX) && defined(Q_PROCESSOR_ARM)
+#define SHOULD_CHECK_ARM_ON_X86
+
+#include <QFileInfo>
+
+#if QT_CONFIG(process) && QT_CONFIG(regularexpression)
+#include <QProcess>
+#include <QRegularExpression>
+#endif
+
+#endif
+
+QT_BEGIN_NAMESPACE
+
+// Helper functions for detecting if running emulated
+namespace QTestPrivate {
+
+#ifdef SHOULD_CHECK_ARM_ON_X86
+static bool isX86SpecificFileAvailable(void);
+static bool isReportedArchitectureX86(void);
+#endif
+
+/*
+ * Check if we are running Arm binary on x86 machine.
+ *
+ * Currently this is only able to check on Linux. If not able to
+ * detect, return false.
+ */
+[[maybe_unused]] static bool isRunningArmOnX86()
+{
+#ifdef SHOULD_CHECK_ARM_ON_X86
+    if (isX86SpecificFileAvailable())
+        return true;
+
+    if (isReportedArchitectureX86())
+        return true;
+#endif
+    return false;
+}
+
+#ifdef SHOULD_CHECK_ARM_ON_X86
+/*
+ * Check if we can find a file that's only available on x86
+ */
+static bool isX86SpecificFileAvailable()
+{
+    // MTRR (Memory Type Range Registers) are a feature of the x86 architecture
+    // and /proc/mtrr is only present (on Linux) for that family.
+    // However, it's an optional kernel feature, so the absence of the file is
+    // not sufficient to conclude we're on real hardware.
+    QFileInfo mtrr("/proc/mtrr");
+    if (mtrr.exists())
+        return true;
+    return false;
+}
+
+/*
+ * Check if architecture reported by the OS is x86
+ */
+static bool isReportedArchitectureX86(void)
+{
+#if QT_CONFIG(process) && QT_CONFIG(regularexpression)
+    QProcess unamer;
+    QString machineString;
+
+    // Using syscall "uname" is not possible since that would be captured by
+    // QEMU and result would be the architecture being emulated (e.g. armv7l).
+    // By using QProcess we get the architecture used by the host.
+    unamer.start("uname -a");
+    if (!unamer.waitForFinished()) {
+        return false;
+    }
+    machineString = unamer.readAll();
+
+    // Is our current host cpu x86?
+    if (machineString.contains(QRegularExpression("i386|i686|x86"))) {
+        return true;
+    }
+#endif
+
+    return false;
+}
+#endif // SHOULD_CHECK_ARM_ON_X86
+
+} // QTestPrivate namespace
+
+QT_END_NAMESPACE
+
+#endif
+