QLibraryInfo: Add isSharedBuild() function and deprecate qSharedBuild()

Now that there's QLibraryInfo::isDebugBuild(), it's better to also
have QLibraryInfo::isSharedBuild() at the same time. It's also a
very useful information about the current Qt build.
I think debug/release and static/shared are the most important
properties of a library, so it's better to have them both.

Deprecate the global function qSharedBuild() in favor of the newly
introduced QLibraryInfo::isSharedBuild().

As a drive-by, add the nodiscard attribute to both functions.

[ChangeLog][QtCore] Added QLibraryInfo::isSharedBuild() and deprecated
qSharedBuild().

Change-Id: I48fa0dc5eeca97e709d5267733fa70aae244174f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/global/qlibraryinfo.cpp

@@ -235,6 +235,19 @@ QLibraryInfo::isDebugBuild() noexcept
 #endif
 }
 
+/*!
+    \since 6.5
+    Returns \c true if this is a shared (dynamic) build of Qt.
+*/
+bool QLibraryInfo::isSharedBuild() noexcept
+{
+#ifdef QT_SHARED
+    return true;
+#else
+    return false;
+#endif
+}
+
 /*!
     \since 5.8
     Returns the version of the Qt library.
@@ -646,15 +659,15 @@ QStringList QLibraryInfo::platformPluginArguments(const QString &platformName)
     \deprecated Use LibraryPath with QLibraryInfo::path() instead.
 */
 
+#if QT_DEPRECATED_SINCE(6, 9)
+
 bool qSharedBuild() noexcept
 {
-#ifdef QT_SHARED
-    return true;
-#else
-    return false;
-#endif
+    return QLibraryInfo::isSharedBuild();
 }
 
+#endif // QT_DEPRECATED_SINCE(6, 9)
+
 QT_END_NAMESPACE
 
 #if defined(Q_CC_GNU) && defined(ELF_INTERPRETER)

src/corelib/global/qlibraryinfo.h

@@ -15,7 +15,8 @@ class Q_CORE_EXPORT QLibraryInfo
 public:
     static const char *build() noexcept;
 
-    static bool isDebugBuild() noexcept Q_DECL_CONST_FUNCTION;
+    [[nodiscard]] static bool isDebugBuild() noexcept Q_DECL_CONST_FUNCTION;
+    [[nodiscard]] static bool isSharedBuild() noexcept Q_DECL_CONST_FUNCTION;
 
 #ifndef QT_BOOTSTRAPPED
     static QVersionNumber version() noexcept Q_DECL_CONST_FUNCTION;
@@ -53,8 +54,13 @@ private:
     QLibraryInfo();
 };
 
+#if QT_DEPRECATED_SINCE(6, 9)
+
+QT_DEPRECATED_VERSION_X_6_9("Use QLibraryInfo::isSharedBuild() instead.")
 Q_CORE_EXPORT Q_DECL_CONST_FUNCTION bool qSharedBuild() noexcept;
 
+#endif
+
 QT_END_NAMESPACE
 
 #endif // QLIBRARYINFO_H

src/corelib/global/qtdeprecationmarkers.h

@@ -187,6 +187,14 @@ QT_BEGIN_NAMESPACE
 # define QT_DEPRECATED_VERSION_6_8
 #endif
 
+#if QT_WARN_DEPRECATED_UP_TO >= QT_VERSION_CHECK(6, 9, 0)
+# define QT_DEPRECATED_VERSION_X_6_9(text) QT_DEPRECATED_X(text)
+# define QT_DEPRECATED_VERSION_6_9         QT_DEPRECATED
+#else
+# define QT_DEPRECATED_VERSION_X_6_9(text)
+# define QT_DEPRECATED_VERSION_6_9
+#endif
+
 #define QT_DEPRECATED_VERSION_X_5(minor, text)      QT_DEPRECATED_VERSION_X_5_##minor(text)
 #define QT_DEPRECATED_VERSION_X(major, minor, text) QT_DEPRECATED_VERSION_X_##major##_##minor(text)
 
@@ -277,6 +285,12 @@ QT_BEGIN_NAMESPACE
 # define QT_IF_DEPRECATED_SINCE_6_8(whenTrue, whenFalse) whenTrue
 #endif
 
+#if QT_DEPRECATED_SINCE(6, 9)
+# define QT_IF_DEPRECATED_SINCE_6_9(whenTrue, whenFalse) whenFalse
+#else
+# define QT_IF_DEPRECATED_SINCE_6_9(whenTrue, whenFalse) whenTrue
+#endif
+
 #ifdef __cplusplus
 // A tag to help mark stuff deprecated (cf. QStringViewLiteral)
 namespace QtPrivate {