This should check if Qt provides zlib functions, and adds zlib dependency in case of zlibless Qt. Tested with Qt providing zlib functions only.
/***************************************************************************/
/* */
/* smooth.c */
/* */
/* FreeType anti-aliasing rasterer module component (body only). */
/* */
/* Copyright 1996-2001 by */
/* David Turner, Robert Wilhelm, and Werner Lemberg. */
/* */
/* This file is part of the FreeType project, and may only be used, */
/* modified, and distributed under the terms of the FreeType project */
/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
/* this file you indicate that you have read the license and */
/* understand and accept it fully. */
/* */
/***************************************************************************/
#define FT_MAKE_OPTION_SINGLE_OBJECT
#include <ft2build.h>
#include "ftspic.c"
#include "ftgrays.c"
#include "ftsmooth.c"
/* END */