cl_build. In the case of failure you should
free the memory occupied by the engine with cl_free:
int cl_build(struct cl_engine *engine); void cl_free(struct cl_engine *engine);In our example:
if((ret = cl_build(engine))) {
printf("cl_build() error: %s\n", cl_strerror(ret));
cl_free(engine);
exit(1);
}