gcc -O2 -O3 -c find_nonzero.c 
In file included from find_nonzero.c:8:0:
find_nonzero.h: In function 'myflsl':
find_nonzero.h:62:12: error: '__WORDSIZE' undeclared (first use in this function)
find_nonzero.h:62:12: note: 
   each undeclared identifier is reported only once for each function it appears in
gmake: *** [find_nonzero.o] Error 1
*** Error code 2

＠ strdupa:

 int ast_playtones_start(struct ast_channel *chan, int vol, const char *playlst, int \
nterruptible) X {
-	char *s, *data = strdupa(playlst); /* cute */
+	char *s, *data;
 	struct playtones_def d = { vol, -1, 0, 1, NULL};
 	char *stringp=NULL;
+
+	data = alloca(strlen(playlst) + 1);
 	if (!data)
 		return -1;
+	strcpy(data, playlst);
 	if (vol < 1)
 		d.vol = 8192;