Move qVersion() from qglobal.h to qlibraryinfo.h

Since qVersion() might be called also from C code, disable the parts of
qlibraryinfo.h that are relevant only for C++ code if __cplusplus is not
defined.

[ChangeLog][Potentially Source-Incompatible Changes] qVersion() is
moved from qglobal.h to qlibraryinfo.h, '#include <QtCore/QLibraryInfo>'
needs to be added where it's used.

Task-number: QTBUG-99313
Change-Id: I3363ef3fa4073114e5151cb3a2a1e8282ad42a4d
Reviewed-by: Thiago Macieira <[email protected]>
Reviewed-by: Edward Welbourne <[email protected]>

13 files changed, 45 insertions, 28 deletions

diff --git a/qmake/generators/makefile.cpp b/qmake/generators/makefile.cpp
index 4c21ef8202b..06ca1807a73 100644
--- a/qmake/generators/makefile.cpp
+++ b/qmake/generators/makefile.cpp
@@ -16,6 +16,7 @@
 #include <qdebug.h>
 #include <qbuffer.h>
 #include <qdatetime.h>
+#include <qlibraryinfo.h>
 
 #if defined(Q_OS_UNIX)
 #include <unistd.h>
diff --git a/qmake/generators/unix/unixmake2.cpp b/qmake/generators/unix/unixmake2.cpp
index 98c7e217cf0..1b2989b9788 100644
--- a/qmake/generators/unix/unixmake2.cpp
+++ b/qmake/generators/unix/unixmake2.cpp
@@ -10,6 +10,7 @@
 #include <qfile.h>
 #include <qdir.h>
 #include <qdebug.h>
+#include <qlibraryinfo.h>
 #include <time.h>
 
 #include <tuple>
diff --git a/qmake/option.cpp b/qmake/option.cpp
index f0e6c503412..55f21120c0c 100644
--- a/qmake/option.cpp
+++ b/qmake/option.cpp
@@ -12,6 +12,7 @@
 #include <stdarg.h>
 
 #include <qmakelibraryinfo.h>
+#include <qlibraryinfo.h>
 #include <private/qlibraryinfo_p.h>
 
 QT_BEGIN_NAMESPACE
diff --git a/qmake/property.cpp b/qmake/property.cpp
index 358d7f3a3c2..6ac13213554 100644
--- a/qmake/property.cpp
+++ b/qmake/property.cpp
@@ -5,6 +5,7 @@
 
 #include <qdir.h>
 #include <qsettings.h>
+#include <qlibraryinfo.h>
 #include <qmakelibraryinfo.h>
 #include <qstringlist.h>
 #include <stdio.h>
diff --git a/src/corelib/global/qglobal.cpp b/src/corelib/global/qglobal.cpp
index 0e5b2d5b805..ffc899da8bc 100644
--- a/src/corelib/global/qglobal.cpp
+++ b/src/corelib/global/qglobal.cpp
@@ -792,21 +792,6 @@ using namespace Qt::StringLiterals;
     \sa qVersion(), QT_VERSION
 */
 
-/*!
-    \relates <QtGlobal>
-
-    Returns the version number of Qt at runtime as a string (for example,
-    "6.1.2"). This may be a different version than the version the application
-    was \e compiled with.
-
-    \sa QT_VERSION_STR, QLibraryInfo::version()
-*/
-
-const char *qVersion() noexcept
-{
-    return QT_VERSION_STR;
-}
-
 /*****************************************************************************
   System detection routines
  *****************************************************************************/
diff --git a/src/corelib/global/qglobal.h b/src/corelib/global/qglobal.h
index c55b6ee754b..6a247f9ea4e 100644
--- a/src/corelib/global/qglobal.h
+++ b/src/corelib/global/qglobal.h
@@ -48,19 +48,6 @@ inline void qt_noop(void) {}
 #ifndef __ASSEMBLER__
 QT_BEGIN_NAMESPACE
 
-/*
- * If we're compiling C++ code:
- *  - and this is a non-namespace build, declare qVersion as extern "C"
- *  - and this is a namespace build, declare it as a regular function
- *    (we're already inside QT_BEGIN_NAMESPACE / QT_END_NAMESPACE)
- * If we're compiling C code, simply declare the function. If Qt was compiled
- * in a namespace, qVersion isn't callable anyway.
- */
-#if !defined(QT_NAMESPACE) && defined(__cplusplus) && !defined(Q_QDOC)
-extern "C"
-#endif
-Q_CORE_EXPORT Q_DECL_CONST_FUNCTION const char *qVersion(void) Q_DECL_NOEXCEPT;
-
 #if defined(__cplusplus)
 
 #if 0
diff --git a/src/corelib/global/qlibraryinfo.cpp b/src/corelib/global/qlibraryinfo.cpp
index 5b148dd42cf..fe9bc218aa5 100644
--- a/src/corelib/global/qlibraryinfo.cpp
+++ b/src/corelib/global/qlibraryinfo.cpp
@@ -659,6 +659,21 @@ QStringList QLibraryInfo::platformPluginArguments(const QString &platformName)
     \deprecated Use LibraryPath with QLibraryInfo::path() instead.
 */
 
+/*!
+    \relates <QLibraryInfo>
+
+    Returns the version number of Qt at runtime as a string (for example,
+    "6.1.2"). This is the version of the Qt library in use at \e runtime,
+    which need not be the version the application was \e compiled with.
+
+    \sa QT_VERSION_STR, QLibraryInfo::version()
+*/
+
+const char *qVersion() noexcept
+{
+    return QT_VERSION_STR;
+}
+
 #if QT_DEPRECATED_SINCE(6, 9)
 
 bool qSharedBuild() noexcept
diff --git a/src/corelib/global/qlibraryinfo.h b/src/corelib/global/qlibraryinfo.h
index d4e8f8b0506..71d9a013080 100644
--- a/src/corelib/global/qlibraryinfo.h
+++ b/src/corelib/global/qlibraryinfo.h
@@ -4,12 +4,18 @@
 #ifndef QLIBRARYINFO_H
 #define QLIBRARYINFO_H
 
+#if defined(__cplusplus)
 #include <QtCore/qstring.h>
 #include <QtCore/qdatetime.h>
 #include <QtCore/qversionnumber.h>
+#else
+#include <QtCore/qglobal.h>
+#endif
 
 QT_BEGIN_NAMESPACE
 
+#if defined(__cplusplus)
+
 class Q_CORE_EXPORT QLibraryInfo
 {
 public:
@@ -61,6 +67,21 @@ Q_CORE_EXPORT Q_DECL_CONST_FUNCTION bool qSharedBuild() noexcept;
 
 #endif
 
+#endif // __cplusplus
+
+/*
+ * If we're compiling C++ code:
+ *  - and this is a non-namespace build, declare qVersion as extern "C"
+ *  - and this is a namespace build, declare it as a regular function
+ *    (we're already inside QT_BEGIN_NAMESPACE / QT_END_NAMESPACE)
+ * If we're compiling C code, simply declare the function. If Qt was compiled
+ * in a namespace, qVersion isn't callable anyway.
+ */
+#if !defined(QT_NAMESPACE) && defined(__cplusplus) && !defined(Q_QDOC)
+extern "C"
+#endif
+Q_CORE_EXPORT Q_DECL_CONST_FUNCTION const char *qVersion(void) Q_DECL_NOEXCEPT;
+
 QT_END_NAMESPACE
 
 #endif // QLIBRARYINFO_H
diff --git a/src/gui/accessible/linux/atspiadaptor.cpp b/src/gui/accessible/linux/atspiadaptor.cpp
index 91d0e47415c..46b4fbe0dc3 100644
--- a/src/gui/accessible/linux/atspiadaptor.cpp
+++ b/src/gui/accessible/linux/atspiadaptor.cpp
@@ -11,6 +11,7 @@
 #include <qclipboard.h>
 
 #include <QtCore/qloggingcategory.h>
+#include <QtCore/qlibraryinfo.h>
 
 #if QT_CONFIG(accessibility)
 #include "socket_interface.h"
diff --git a/tests/auto/corelib/global/qglobal/qglobal.c b/tests/auto/corelib/global/qglobal/qglobal.c
index 3b898de39ff..64569f4de7b 100644
--- a/tests/auto/corelib/global/qglobal/qglobal.c
+++ b/tests/auto/corelib/global/qglobal/qglobal.c
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
 
 #include <QtCore/qglobal.h>
+#include <QtCore/qlibraryinfo.h>
 
 #ifdef Q_COMPILER_THREAD_LOCAL
 #  include <threads.h>
diff --git a/tests/auto/corelib/global/qglobal/tst_qglobal.cpp b/tests/auto/corelib/global/qglobal/tst_qglobal.cpp
index 752fb948a5d..3923b6d6ac3 100644
--- a/tests/auto/corelib/global/qglobal/tst_qglobal.cpp
+++ b/tests/auto/corelib/global/qglobal/tst_qglobal.cpp
@@ -8,6 +8,7 @@
 #include <QSysInfo>
 #include <QLatin1String>
 #include <QString>
+#include <QLibraryInfo>
 
 #include <cmath>
 
diff --git a/tests/manual/highdpi/dprgadget/main.cpp b/tests/manual/highdpi/dprgadget/main.cpp
index 9da74b48936..c8d7add901f 100644
--- a/tests/manual/highdpi/dprgadget/main.cpp
+++ b/tests/manual/highdpi/dprgadget/main.cpp
@@ -1,6 +1,7 @@
 // Copyright (C) 2020 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
 
+#include <QtCore/qlibraryinfo.h>
 #include <QtGui/qpa/qplatformscreen.h>
 #include <QtGui/qpa/qplatformwindow.h>
 #include <QtGui/private/qhighdpiscaling_p.h>
diff --git a/tests/manual/shortcuts/main.cpp b/tests/manual/shortcuts/main.cpp
index e7127f37964..bcdd47cab75 100644
--- a/tests/manual/shortcuts/main.cpp
+++ b/tests/manual/shortcuts/main.cpp
@@ -8,6 +8,7 @@
 #include <QLabel>
 #include <QPushButton>
 #include <QDebug>
+#include <QLibraryInfo>
 
 class ShortcutTester : public QWidget
 {