Basic set of changes to compile on FreeBSD that are hard to shim around
in compat headers.

 - The compare function passed to fts_open takes (const FTSENT * const *)
   arguments in FreeBSD.
 - Add a NO_SHA384 option since FreeBSD has support for 256 and 512 but
   not 384.  (It might make sense to allow all three to be disabled
   individually.)
 - Explicitly include <sys/stat.h> in compare.c.  The required symbols
   are not pulled in by another header in FreeBSD.
 - Don't declare sflag twice.
 - FreeBSD has __dead2 not __dead.

Index: create.c
===================================================================
--- create.c	(revision 240705)
+++ create.c	(revision 240706)
@@ -83,7 +83,7 @@
 static mode_t mode;
 static u_long flags;
 
-static int	dcmp(const FTSENT **, const FTSENT **);
+static int	dcmp(const FTSENT * const *, const FTSENT * const *);
 static void	output(int *, const char *, ...)
 	__attribute__((__format__(__printf__, 2, 3)));
 static int	statd(FTS *, FTSENT *, uid_t *, gid_t *, mode_t *, u_long *);
@@ -242,12 +242,14 @@
 		output(&indent, "sha256=%s", digestbuf);
 		free(digestbuf);
 	}
+#ifndef NO_SHA384
 	if (keys & F_SHA384 && S_ISREG(p->fts_statp->st_mode)) {
 		if ((digestbuf = SHA384_File(p->fts_accpath, NULL)) == NULL)
 			mtree_err("%s: SHA384_File failed: %s", p->fts_accpath, strerror(errno));
 		output(&indent, "sha384=%s", digestbuf);
 		free(digestbuf);
 	}
+#endif
 	if (keys & F_SHA512 && S_ISREG(p->fts_statp->st_mode)) {
 		if ((digestbuf = SHA512_File(p->fts_accpath, NULL)) == NULL)
 			mtree_err("%s: SHA512_File failed: %s", p->fts_accpath, strerror(errno));
@@ -398,7 +400,7 @@
  * Keep this in sync with nodecmp() in spec.c.
  */
 static int
-dcmp(const FTSENT **a, const FTSENT **b)
+dcmp(const FTSENT * const *a, const FTSENT * const *b)
 {
 
 	if (S_ISDIR((*a)->fts_statp->st_mode)) {
Index: compare.c
===================================================================
--- compare.c	(revision 240705)
+++ compare.c	(revision 240706)
@@ -43,6 +43,7 @@
 #endif /* not lint */
 
 #include <sys/param.h>
+#include <sys/stat.h>
 
 #include <errno.h>
 #include <fcntl.h>
@@ -462,6 +463,7 @@
 			free(digestbuf);
 		}
 	}
+#ifndef NO_SHA384
 	if (s->flags & F_SHA384) {
 		if ((digestbuf = SHA384_File(p->fts_accpath, NULL)) == NULL) {
 			LABEL;
@@ -478,6 +480,7 @@
 			free(digestbuf);
 		}
 	}
+#endif	/* ! NO_SHA384 */
 	if (s->flags & F_SHA512) {
 		if ((digestbuf = SHA512_File(p->fts_accpath, NULL)) == NULL) {
 			LABEL;
Index: crc.c
===================================================================
--- crc.c	(revision 240705)
+++ crc.c	(revision 240706)
@@ -114,7 +114,6 @@
  * locations to store the crc and the number of bytes read.  It returns 0 on
  * success and 1 on failure.  Errno is set on failure.
  */
-extern int sflag;
 u_int32_t crc_total = ~0;		/* The crc over a number of files. */
 
 int
Index: extern.h
===================================================================
--- extern.h	(revision 240705)
+++ extern.h	(revision 240706)
@@ -60,7 +60,7 @@
 void	 dump_nodes(const char *, NODE *, int);
 void	 init_excludes(void);
 int	 matchtags(NODE *);
-__dead __printflike(1,2) void	 mtree_err(const char *, ...);
+__dead2 __printflike(1,2) void	 mtree_err(const char *, ...);
 const char *nodetype(u_int);
 u_int	 parsekey(const char *, int *);
 void	 parsetags(slist_t *, char *);
Index: mtree.c
===================================================================
--- mtree.c	(revision 240705)
+++ mtree.c	(revision 240706)
@@ -63,7 +63,7 @@
     	rflag, sflag, tflag, uflag, Uflag;
 char	fullpath[MAXPATHLEN];
 
-__dead static	void	usage(void);
+__dead2 static	void	usage(void);
 
 int
 main(int argc, char **argv)