Add macro to export main function replacing hack setting default visibility

Author: Martchus

application/global.h

@@ -84,6 +84,22 @@
 #define CPP_UTILITIES_GENERIC_LIB_HIDDEN __attribute__((visibility("hidden")))
 #endif
 
+/*!
+ * \def CPP_UTILITIES_MAIN_EXPORT
+ * \brief Exports the main() functions on platforms where this is needed.
+ * \remarks Needed on Android with Qt where applications are shared libraries.
+ *          Otherwise loading the app will fail with the error "dlsym failed: undefined
+ *          symbol: main".
+ * \sa See qtbase commit 29b17fa335388c9b93f70c29b2398cf2fee65785 (where this is solved
+       with the sledgehammer method of setting the default visibility).
+ */
+
+#ifdef PLATFORM_ANDROID
+#define CPP_UTILITIES_MAIN_EXPORT CPP_UTILITIES_GENERIC_LIB_EXPORT
+#else
+#define CPP_UTILITIES_MAIN_EXPORT
+#endif
+
 /*!
  * \def CPP_UTILITIES_UNUSED
  * \brief Prevents warnings about unused variables.

cmake/modules/AppTarget.cmake

@@ -70,12 +70,7 @@ set_target_properties(
                AUTOGEN_TARGET_DEPENDS "${AUTOGEN_DEPS}"
                QT_DEFAULT_PLUGINS "${META_QT_DEFAULT_PLUGINS}"
                EXPORT_COMPILE_COMMANDS "${ENABLE_EXPORT_COMPILE_COMMANDS}")
-if (NOT ANDROID)
-    set_target_properties(${META_TARGET_NAME} PROPERTIES C_VISIBILITY_PRESET hidden CXX_VISIBILITY_PRESET hidden)
-    # note: Android *.so files need CXX visibility set to default (see qtbase commit
-    # 29b17fa335388c9b93f70c29b2398cf2fee65785). Otherwise loading the app will fail with the error "dlsym failed: undefined
-    # symbol: main".
-endif ()
+set_target_properties(${META_TARGET_NAME} PROPERTIES C_VISIBILITY_PRESET hidden CXX_VISIBILITY_PRESET hidden)
 if (NOT META_CXX_STANDARD STREQUAL "any")
     set_target_properties(${META_TARGET_NAME} PROPERTIES CXX_STANDARD "${META_CXX_STANDARD}")
 endif ()