[PATCH] maint: update to work with GCC7's -Werror=implicit-fallthrough=

[Jim Meyering]

I've just pushed this:

>From b47afb1438293decd3982d8097157411ba6b5ed4 Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Sat, 10 Jun 2017 10:11:47 -0700
Subject: [PATCH] maint: update to work with GCC7's
 -Werror=implicit-fallthrough=

* lib/savewd.c (FALLTHROUGH): Define.
(savewd_save, savewd_restore): Use this, rather than a comment,
whenever one switch case falls through into the next.
---
 ChangeLog    |  7 +++++++
 lib/savewd.c | 12 ++++++++++--
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 19fa986e4..abc3c174c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2017-06-10  Jim Meyering  <address@hidden>
+
+       maint: update to work with GCC7's -Werror=implicit-fallthrough=
+       * lib/savewd.c (FALLTHROUGH): Define.
+       (savewd_save, savewd_restore): Use this, rather than a comment,
+       whenever one switch case falls through into the next.
+
 2017-06-08  Bruno Haible  <address@hidden>

        host-cpu-c-abi: Support for aarch64 ILP32 ABI.
diff --git a/lib/savewd.c b/lib/savewd.c
index 33fd85bd5..4579d3066 100644
--- a/lib/savewd.c
+++ b/lib/savewd.c
@@ -36,6 +36,14 @@
 #include "dosname.h"
 #include "fcntl-safer.h"

+#ifndef FALLTHROUGH
+# if __GNUC__ < 7
+#  define FALLTHROUGH ((void) 0)
+# else
+#  define FALLTHROUGH __attribute__ ((__fallthrough__))
+# endif
+#endif
+
 /* Save the working directory into *WD, if it hasn't been saved
    already.  Return true if a child has been forked to do the real
    work.  */
@@ -63,7 +71,7 @@ savewd_save (struct savewd *wd)
       }
       wd->state = FORKING_STATE;
       wd->val.child = -1;
-      /* Fall through.  */
+      FALLTHROUGH;
     case FORKING_STATE:
       if (wd->val.child < 0)
         {
@@ -188,7 +196,7 @@ savewd_restore (struct savewd *wd, int status)
           wd->state = ERROR_STATE;
           wd->val.errnum = chdir_errno;
         }
-      /* Fall through.  */
+      FALLTHROUGH;
     case ERROR_STATE:
       /* Report an error if asked to restore the working directory.  */
       errno = wd->val.errnum;
-- 
2.13.0