char *m4sugar = xconcatenated_filename (datadir, "m4sugar/m4sugar.m4", NULL);
char *m4bison = xconcatenated_filename (datadir, "bison.m4", NULL);
char *skel = (IS_PATH_WITH_DIR (skeleton)
char *m4sugar = xconcatenated_filename (datadir, "m4sugar/m4sugar.m4", NULL);
char *m4bison = xconcatenated_filename (datadir, "bison.m4", NULL);
char *skel = (IS_PATH_WITH_DIR (skeleton)