Add support for C11 static_assert and thread_local

Tested with Clang, GCC 4.5 & up, ICC 17 and MSVC 2017. No current
version of MSVC supports C11 and GCC implemented the features slightly
later in C than in C++.

Change-Id: I57a1bd6e0c194530b732fffd14f45c5074c9a052
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

3 files changed, 129 insertions, 1 deletions

diff --git a/tests/auto/corelib/global/qglobal/qglobal.c b/tests/auto/corelib/global/qglobal/qglobal.c
new file mode 100644
index 0000000000..6a6f53dfe0
--- /dev/null
+++ b/tests/auto/corelib/global/qglobal/qglobal.c
@@ -0,0 +1,111 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 Intel Corporation.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtCore/qglobal.h>
+
+#if QT_HAS_INCLUDE(<stdbool.h>) || __STDC_VERSION__ >= 199901L
+#  include <stdbool.h>
+#else
+#  undef true
+#  define true 1
+#  undef false
+#  define false 0
+#endif
+
+#ifdef Q_COMPILER_THREAD_LOCAL
+#  include <threads.h>
+#endif
+
+/*
+ * Certain features of qglobal.h must work in C mode too. We test that
+ * everything works.
+ */
+
+/* Types and Q_UNUSED */
+void tst_GlobalTypes()
+{
+    qint8 s8;
+    qint16 s16;
+    qint32 s32;
+    qint64 s64;
+    qlonglong sll;
+    Q_UNUSED(s8); Q_UNUSED(s16); Q_UNUSED(s32); Q_UNUSED(s64); Q_UNUSED(sll);
+
+    quint8 u8;
+    quint16 u16;
+    quint32 u32;
+    quint64 u64;
+    qulonglong ull;
+    Q_UNUSED(u8); Q_UNUSED(u16); Q_UNUSED(u32); Q_UNUSED(u64); Q_UNUSED(ull);
+
+    uchar uc;
+    ushort us;
+    uint ui;
+    ulong ul;
+    Q_UNUSED(uc); Q_UNUSED(us); Q_UNUSED(ui); Q_UNUSED(ul);
+
+    qreal qr;
+    Q_UNUSED(qr);
+}
+
+/* Qt version */
+int tst_QtVersion()
+{
+    return QT_VERSION;
+}
+
+const char *tst_qVersion() Q_DECL_NOTHROW
+{
+#if !defined(QT_NAMESPACE)
+    return qVersion();
+#else
+    return NULL;
+#endif
+}
+
+/* Static assertion */
+Q_STATIC_ASSERT(true);
+Q_STATIC_ASSERT(1);
+Q_STATIC_ASSERT_X(true, "Message");
+Q_STATIC_ASSERT_X(1, "Message");
+
+Q_STATIC_ASSERT(!false);
+Q_STATIC_ASSERT(!0);
+
+Q_STATIC_ASSERT(!!true);
+Q_STATIC_ASSERT(!!1);
+
+#ifdef Q_COMPILER_THREAD_LOCAL
+static thread_local int gt_var;
+void thread_local_test()
+{
+    thread_local int t_var;
+    t_var = gt_var;
+}
+#endif
+
diff --git a/tests/auto/corelib/global/qglobal/qglobal.pro b/tests/auto/corelib/global/qglobal/qglobal.pro
index b8ed7761f5..a40cb9a288 100644
--- a/tests/auto/corelib/global/qglobal/qglobal.pro
+++ b/tests/auto/corelib/global/qglobal/qglobal.pro
@@ -1,4 +1,4 @@
 CONFIG += testcase
 TARGET = tst_qglobal
 QT = core testlib
-SOURCES = tst_qglobal.cpp
+SOURCES = tst_qglobal.cpp qglobal.c
diff --git a/tests/auto/corelib/global/qglobal/tst_qglobal.cpp b/tests/auto/corelib/global/qglobal/tst_qglobal.cpp
index 083526fdc4..78b954f373 100644
--- a/tests/auto/corelib/global/qglobal/tst_qglobal.cpp
+++ b/tests/auto/corelib/global/qglobal/tst_qglobal.cpp
@@ -39,6 +39,7 @@ class tst_QGlobal: public QObject
     Q_OBJECT
 
 private slots:
+    void cMode();
     void qIsNull();
     void for_each();
     void qassert();
@@ -56,6 +57,22 @@ private slots:
     void testqOverload();
 };
 
+extern "C" {        // functions in qglobal.c
+void tst_GlobalTypes();
+int tst_QtVersion();
+const char *tst_qVersion();
+}
+
+void tst_QGlobal::cMode()
+{
+    tst_GlobalTypes();
+    QCOMPARE(tst_QtVersion(), QT_VERSION);
+
+#ifndef QT_NAMESPACE
+    QCOMPARE(tst_qVersion(), qVersion());
+#endif
+}
+
 void tst_QGlobal::qIsNull()
 {
     double d = 0.0;