We need to filter out platform-specific sources from the files that we
use with the introspection scanner.
In this specific case I could have moved the gtkclipboard-quartz.c and
the gtkdnd-quartz.c files out of the $(gtk_base_c_sources) variable, but
doing a filter-out on the variable itself is more resilient in case we
eventually add files and we forget about the result.
if HAVE_INTROSPECTION
introspection_files = \
$(filter-out %private.h gtktextdisplay.h gtktextlayout.h gtkx.h, $(gtkinclude_HEADERS) $(a11yinclude_HEADERS) $(deprecatedinclude_HEADERS)) \
- $(gtk_base_c_sources) \
+ $(filter-out %win32.c %quartz.c, $(gtk_base_c_sources)) \
gtkprintoperation-unix.c \
gtktypebuiltins.h \
gtktypebuiltins.c