fix compilation on windows

meson.build

@@ -603,7 +603,8 @@ test_cflags = [
   '-DACCESS_READ_ONLY(...)=' + (is_gcc ? 'ACCESS(read_only,__VA_ARGS__)' : ''),
   ]
 
-if is_gcc
+# not supported on windows
+if is_gcc and not os_windows
   test_cflags += [
     '-frecord-gcc-switches',
     ]

src/plugins/carla_native_plugin.c

@@ -21,6 +21,7 @@
 
 #ifdef HAVE_CARLA
 
+#include <inttypes.h>
 #include <math.h>
 #include <stdlib.h>
 

src/utils/gtk.c

@@ -2040,7 +2040,7 @@ z_gtk_window_get_windows_hwnd (
   GdkSurface * surface =
     gtk_native_get_surface (native);
   HWND hwnd = GDK_SURFACE_HWND (surface);
-  g_return_val_if_fail (hwnd);
+  g_return_val_if_fail (hwnd, NULL);
   return hwnd;
 }
 #endif