Revert "modules: Fix build on Visual Studio"

This reverts commit acd9c12667.

This commit breaks the build with GLib main,
we now get complaints about _GLIB_EXTERN being
redefined.

Maybe it is not needed anymore anyway, since
export macros have seen Window-related fixes.

meson.build

@@ -342,19 +342,15 @@ endif
 common_cflags = cc.get_supported_arguments(test_cflags)
 
 # Symbol visibility
-
-if os_win32
-  visibility_define = '__declspec(dllexport) extern'
-else
-  visibility_define = '__attribute__((visibility("default"))) extern'
-endif
-
 if get_option('default_library') != 'static'
-  cdata.set('_GDK_EXTERN', visibility_define)
   if os_win32
     cdata.set('DLL_EXPORT', true)
-  endif
-  if cc.get_id() != 'msvc'
+    cdata.set('_GDK_EXTERN', '__declspec(dllexport) extern')
+    if cc.get_id() != 'msvc'
+      common_cflags += ['-fvisibility=hidden']
+    endif
+  else
+    cdata.set('_GDK_EXTERN', '__attribute__((visibility("default"))) extern')
     common_cflags += ['-fvisibility=hidden']
   endif
 endif

modules/media/gtkgstmediafile.c

@@ -97,6 +97,7 @@ G_DEFINE_TYPE_EXTENDED (GtkGstMediaFile, gtk_gst_media_file, GTK_TYPE_MEDIA_FILE
                         G_IMPLEMENT_INTERFACE (GDK_TYPE_PAINTABLE,
                                                gtk_gst_media_file_paintable_init))
 
+G_MODULE_EXPORT
 void
 g_io_module_load (GIOModule *module)
 {
@@ -108,6 +109,7 @@ g_io_module_load (GIOModule *module)
                                   10);
 }
 
+G_MODULE_EXPORT
 G_GNUC_NORETURN
 void
 g_io_module_unload (GIOModule *module)
@@ -115,6 +117,7 @@ g_io_module_unload (GIOModule *module)
   g_assert_not_reached ();
 }
 
+G_MODULE_EXPORT
 char **
 g_io_module_query (void)
 {

modules/media/meson.build

@@ -2,11 +2,7 @@ media_subdir = 'gtk-4.0/@0@/media'.format(gtk_binary_version)
 media_install_dir = join_paths(get_option('libdir'), media_subdir)
 media_backends = []
 
-extra_c_args = [
-  '-DGTK_COMPILATION',
-  '-D_GLIB_EXTERN=@0@'.format(visibility_define),
-]
-
+extra_c_args = ['-DGTK_COMPILATION']
 extra_c_args += common_cflags
 
 ffmpeg_opt = get_option('media-ffmpeg')

modules/printbackends/gtkprintbackendcups.c

@@ -246,6 +246,7 @@ static void                 secrets_service_vanished_cb             (GDBusConnec
 
 G_DEFINE_DYNAMIC_TYPE(GtkPrintBackendCups, gtk_print_backend_cups, GTK_TYPE_PRINT_BACKEND)
 
+G_MODULE_EXPORT
 void
 g_io_module_load (GIOModule *module)
 {
@@ -260,11 +261,13 @@ g_io_module_load (GIOModule *module)
                                   10);
 }
 
+G_MODULE_EXPORT
 void
 g_io_module_unload (GIOModule *module)
 {
 }
 
+G_MODULE_EXPORT
 char **
 g_io_module_query (void)
 {

modules/printbackends/gtkprintbackendfile.c

@@ -103,6 +103,7 @@ static GtkPageSetup *       file_printer_get_default_page_size     (GtkPrinter
 
 G_DEFINE_DYNAMIC_TYPE(GtkPrintBackendFile, gtk_print_backend_file, GTK_TYPE_PRINT_BACKEND)
 
+G_MODULE_EXPORT
 void
 g_io_module_load (GIOModule *module)
 {
@@ -116,11 +117,13 @@ g_io_module_load (GIOModule *module)
                                   10);
 }
 
+G_MODULE_EXPORT
 void
 g_io_module_unload (GIOModule *module)
 {
 }
 
+G_MODULE_EXPORT
 char **
 g_io_module_query (void)
 {

modules/printbackends/gtkprintbackendlpr.c

@@ -82,6 +82,7 @@ static void                 gtk_print_backend_lpr_print_stream    (GtkPrintBacke
 
 G_DEFINE_DYNAMIC_TYPE (GtkPrintBackendLpr, gtk_print_backend_lpr, GTK_TYPE_PRINT_BACKEND)
 
+G_MODULE_EXPORT
 void
 g_io_module_load (GIOModule *module)
 {
@@ -95,11 +96,13 @@ g_io_module_load (GIOModule *module)
                                   10);
 }
 
+G_MODULE_EXPORT
 void
 g_io_module_unload (GIOModule *module)
 {
 }
 
+G_MODULE_EXPORT
 char **
 g_io_module_query (void)
 {

modules/printbackends/meson.build

@@ -8,7 +8,6 @@ printbackends_args = [
   '-DGTK_COMPILATION',
   '-DGTK_DISABLE_DEPRECATION_WARNINGS',
   '-DGTK_PRINT_BACKEND_ENABLE_UNSUPPORTED',
-  '-D_GLIB_EXTERN=@0@'.format(visibility_define),
 ] + common_cflags
 
 cups_dep = dependency('cups', version : '>=2.0', required: get_option('print-cups'))