Add fall-through comments.

This patch adds fall-through comments in some cases where -Wextra
produces implicit-fallthrough warnings.

The patch is non-exhaustive.  Apart from architecture-specific code
for non-x86_64 architectures, it does not change sunrpc/xdr.c (legacy
code, probably should have such changes, but left to be dealt with
separately), or places that already had comments about the
fall-through but not matching the form expected by
-Wimplicit-fallthrough=3 (the default level with -Wextra; my
inclination is to adjust those comments to match rather than
downgrading to -Wimplicit-fallthrough=1 to allow any comment), or one
place where I thought the implicit fallthrough was not correct and so
should be handled separately as a bug fix.  I think the key thing to
consider in review of this patch is whether the fall-through is indeed
intended and correct in each place where such a comment is added.

Tested for x86_64.

	* elf/dl-exception.c (_dl_exception_create_format): Add
	fall-through comments.
	* elf/ldconfig.c (parse_conf_include): Likewise.
	* elf/rtld.c (print_statistics): Likewise.
	* locale/programs/charmap.c (parse_charmap): Likewise.
	* misc/mntent_r.c (__getmntent_r): Likewise.
	* posix/wordexp.c (parse_arith): Likewise.
	(parse_backtick): Likewise.
	* resolv/ns_ttl.c (ns_parse_ttl): Likewise.
	* sysdeps/x86/cpu-features.c (init_cpu_features): Likewise.
	* sysdeps/x86_64/dl-machine.h (elf_machine_rela): Likewise.

1 files changed, 4 insertions, 0 deletions

diff --git a/resolv/ns_ttl.c b/resolv/ns_ttl.c
index 079948790b..d29d9dc00c 100644
--- a/resolv/ns_ttl.c
+++ b/resolv/ns_ttl.c
@@ -113,9 +113,13 @@ ns_parse_ttl(const char *src, u_long *dst) {
 			ch = toupper(ch);
 		switch (ch) {
 		case 'W':  tmp *= 7;
+		  /* Fall through.  */
 		case 'D':  tmp *= 24;
+		  /* Fall through.  */
 		case 'H':  tmp *= 60;
+		  /* Fall through.  */
 		case 'M':  tmp *= 60;
+		  /* Fall through.  */
 		case 'S':  break;
 		default:   goto einval;
 		}