Use __attribute__((fallthrough)) rather than magic GCC comments.

GCC added an implicit-fallthrough warning a while back, where it
would complain if you had a nontrivial "case:" block that didn't end
with break, return, or something like that.  Clang recently added
the same thing.

GCC, however, would let you annotate a fall-through as intended by
any of various magic "/* fall through */" comments.  Clang, however,
only seems to like "__attribute__((fallthrough))".  Fortunately, GCC
accepts that too.

A previous commit in this branch defined a FALLTHROUGH macro to do
the right thing if GNUC is defined; here we replace all of our "fall
through" comments with uses of that macro.

This is an automated commit, made with the following perl one-liner:

  #!/usr/bin/perl -i -p
  s#/\* *falls? ?thr.*?\*/#FALLTHROUGH;#i;

(In order to avoid conflicts, I'm applying this script separately to
each maint branch. This is the 0.4.3 version.)

1 files changed, 1 insertions, 1 deletions

diff --git a/src/core/or/sendme.c b/src/core/or/sendme.c
index db3e2e94fd..788f56088c 100644
--- a/src/core/or/sendme.c
+++ b/src/core/or/sendme.c
@@ -293,7 +293,7 @@ send_circuit_level_sendme(circuit_t *circ, crypt_path_t *layer_hint,
     log_debug(LD_PROTOCOL, "Emitting SENDME version 1 cell.");
     break;
   case 0x00:
-    /* Fallthrough because default is to use v0. */
+    FALLTHROUGH;
   default:
     /* Unknown version, fallback to version 0 meaning no payload. */
     payload_len = 0;