[src/trunk]: src/sbin/fsck_ffs simplify the endian byte-swapping code.

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/455661c9cf22
branches:  trunk
changeset: 998853:455661c9cf22
user:      christos <christos%NetBSD.org@localhost>
date:      Sun May 05 13:24:19 2019 +0000

description:
simplify the endian byte-swapping code.

diffstat:

 sbin/fsck_ffs/dir.c |  93 +++++++++++++++++++++-------------------------------
 1 files changed, 38 insertions(+), 55 deletions(-)

diffs (137 lines):

diff -r e685fa4fdad3 -r 455661c9cf22 sbin/fsck_ffs/dir.c
--- a/sbin/fsck_ffs/dir.c       Sun May 05 10:04:11 2019 +0000
+++ b/sbin/fsck_ffs/dir.c       Sun May 05 13:24:19 2019 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: dir.c,v 1.59 2018/11/08 06:34:40 msaitoh Exp $ */
+/*     $NetBSD: dir.c,v 1.60 2019/05/05 13:24:19 christos Exp $        */
 
 /*
  * Copyright (c) 1980, 1986, 1993
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "@(#)dir.c      8.8 (Berkeley) 4/28/95";
 #else
-__RCSID("$NetBSD: dir.c,v 1.59 2018/11/08 06:34:40 msaitoh Exp $");
+__RCSID("$NetBSD: dir.c,v 1.60 2019/05/05 13:24:19 christos Exp $");
 #endif
 #endif /* not lint */
 
@@ -144,6 +144,23 @@
        propagate(inumber);
 }
 
+#if (BYTE_ORDER == LITTLE_ENDIAN)
+# define NEEDSWAP      (!needswap)
+#else
+# define NEEDSWAP      (needswap)
+#endif
+
+static void
+dirswap(void *dbuf)
+{
+       struct direct *tdp = (struct direct *)dbuf;
+       u_char tmp;
+
+       tmp = tdp->d_namlen;
+       tdp->d_namlen = tdp->d_type;
+       tdp->d_type = tmp;
+}
+
 /*
  * Scan each entry in a directory block.
  */
@@ -201,33 +218,12 @@
                if (dsize > (int)sizeof dbuf)
                        dsize = sizeof dbuf;
                memmove(dbuf, dp, (size_t)dsize);
-#              if (BYTE_ORDER == LITTLE_ENDIAN)
-                       if (!newinofmt && !needswap) {
-#              else
-                       if (!newinofmt && needswap) {
-#              endif
-                               struct direct *tdp = (struct direct *)dbuf;
-                               u_char tmp;
-
-                               tmp = tdp->d_namlen;
-                               tdp->d_namlen = tdp->d_type;
-                               tdp->d_type = tmp;
-                       }
+               if (!newinofmt && NEEDSWAP)
+                       dirswap(dbuf);
                idesc->id_dirp = (struct direct *)dbuf;
                if ((n = (*idesc->id_func)(idesc)) & ALTERED) {
-#                      if (BYTE_ORDER == LITTLE_ENDIAN)
-                               if (!newinofmt && !doinglevel2 && !needswap) {
-#                      else
-                               if (!newinofmt && !doinglevel2 && needswap) {
-#                      endif
-                                       struct direct *tdp;
-                                       u_char tmp;
-
-                                       tdp = (struct direct *)dbuf;
-                                       tmp = tdp->d_namlen;
-                                       tdp->d_namlen = tdp->d_type;
-                                       tdp->d_type = tmp;
-                               }
+                       if (!newinofmt && !doinglevel2 && NEEDSWAP)
+                               dirswap(dbuf);
                        bp = getdirblk(idesc->id_blkno, blksiz);
                        memmove(bp->b_un.b_buf + idesc->id_loc - dsize, dbuf,
                            (size_t)dsize);
@@ -325,17 +321,13 @@
        if (dp->d_ino == 0)
                return (1);
        size = UFS_DIRSIZ(!newinofmt, dp, needswap);
-#      if (BYTE_ORDER == LITTLE_ENDIAN)
-               if (!newinofmt && !needswap) {
-#      else
-               if (!newinofmt && needswap) {
-#      endif
-                       type = dp->d_namlen;
-                       namlen = dp->d_type;
-               } else {
-                       namlen = dp->d_namlen;
-                       type = dp->d_type;
-               }
+       if (!newinofmt && NEEDSWAP) {
+               type = dp->d_namlen;
+               namlen = dp->d_type;
+       } else {
+               namlen = dp->d_namlen;
+               type = dp->d_type;
+       }
        if (iswap16(dp->d_reclen) < size ||
            idesc->id_filesize < size ||
            /* namlen > MAXNAMLEN || */
@@ -469,23 +461,14 @@
                dirp->d_type = 0;
        dirp->d_namlen = newent.d_namlen;
        memmove(dirp->d_name, idesc->id_name, (size_t)newent.d_namlen + 1);
-#      if (BYTE_ORDER == LITTLE_ENDIAN)
-               /*
-                * If the entry was split, dirscan() will only reverse the byte
-                * order of the original entry, and not the new one, before
-                * writing it back out.  So, we reverse the byte order here if
-                * necessary.
-                */
-               if (oldlen != 0 && !newinofmt && !doinglevel2 && !needswap) {
-#      else
-               if (oldlen != 0 && !newinofmt && !doinglevel2 && needswap) {
-#      endif
-                       u_char tmp;
-
-                       tmp = dirp->d_namlen;
-                       dirp->d_namlen = dirp->d_type;
-                       dirp->d_type = tmp;
-               }
+       /*
+        * If the entry was split, dirscan() will only reverse the byte
+        * order of the original entry, and not the new one, before
+        * writing it back out.  So, we reverse the byte order here if
+        * necessary.
+        */
+       if (oldlen != 0 && !newinofmt && !doinglevel2 && NEEDSWAP)
+               dirswap(dirp);
        return (ALTERED|STOP);
 }