Today I built and installed Coccinelle 1.0.7 on NetBSD.
I am processing this fragment of NetBSD kernel code, `tbr_timeout.c`,
| /*
| * tbr_timeout goes through the interface list, and kicks the drivers
| * if necessary.
| */
| static void
| tbr_timeout(void *arg)
| {
| struct ifnet *ifp;
| int active, s;
|
| active = 0;
| s = splnet();
| for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list)) {
| if (!TBR_IS_ENABLED(&ifp->if_snd))
| #if 1
| continue;
| #endif
| active++;
| if (!IFQ_IS_EMPTY(&ifp->if_snd) && ifp->if_start != NULL)
| (*ifp->if_start)(ifp);
| }
| splx(s);
| if (active > 0)
| CALLOUT_RESET(&tbr_callout, 1, tbr_timeout, NULL);
| else
| tbr_timer = 0; /* don't need tbr_timer anymore */
| }
|
using this semantic patch, `tailq.spatch`,
| @@
| identifier I, N;
| expression H;
| statement S;
| iterator name TAILQ_FOREACH;
| @@
|
| - for (I = TAILQ_FIRST(H); I != NULL; I = TAILQ_NEXT(I, N)) S
| + TAILQ_FOREACH(I, H, N) S
I find that if the condition in the `#if` directive is 1, then `spatch
--sp-file tailq.spatch -o tbr_timeout.spatch tbr_timeout.c` runs for
a few minutes before running out of memory. `spatch` prints this
mysterious message when it starts:
(ONCE) already tagged but only removed, so safe
If I turn the condition to 0, however, spatch instantaneously prints the
result with the `for (...)` clause turned to `TAILQ_FOREACH(...)`, as
expected. I don't see the mysterious `(ONCE) ...` message.
Any ideas why `continue;` is troublesome to spatch?
Dave
--
David Young
dyo...@pobox.com Urbana, IL (217) 721-9981
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