[glib/fix-module-tests-msvc: 12/13] gio/tests/resourceplugin.c: Ensure entry points are exported

[Chun-wei Fan <fanchunwei src gnome org>]

commit edc5eb98c210f01a7ed398a821c689e157e3311b
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Wed Dec 5 17:50:59 2018 +0800

    gio/tests/resourceplugin.c: Ensure entry points are exported
    
    Ensure that the entry points/symbols are exported on Visual Studio
    builds as well.

 gio/tests/resourceplugin.c | 11 +++++++++++
 1 file changed, 11 insertions(+)
---
diff --git a/gio/tests/resourceplugin.c b/gio/tests/resourceplugin.c
index b66d54142..fc8d8d2f1 100644
--- a/gio/tests/resourceplugin.c
+++ b/gio/tests/resourceplugin.c
@@ -1,3 +1,14 @@
+/*
+ * Ensure the g_io_module_*() symbols are exported
+ * on all supported compilers without using config.h.
+ * This must be done before including any GLib headers,
+ * since GLIB_AVAILABLE_IN_ALL, which is used to mark the
+ * g_io_module*() symbols, is defined to be _GLIB_EXTERN,
+ * which must be overriden to export the symbols.
+ */
+#include "modules/symbol-visibility.h"
+#define _GLIB_EXTERN GLIB_TEST_EXPORT_SYMBOL
+
 #include <gio/gio.h>
 
 void