void duk_hthread_catchstack_unwind(duk_hthread *thr, int new_top) {
int idx;
DUK_ASSERT(thr);
DUK_ASSERT(thr->heap);
DUK_ASSERT(new_top >= 0);
DUK_ASSERT(new_top <= thr->catchstack_top); /* cannot grow */
/*
* Since there are no references in the catcher structure,
* unwinding is quite simple. The only thing we need to
* look out for is popping a possible lexical environment
* established for an active catch clause.
*/
idx = thr->catchstack_top;
while (idx > new_top) {
duk_catcher *p;
duk_activation *act;
duk_hobject *env;
idx--;
DUK_ASSERT(idx >= 0 && idx < thr->catchstack_size);
p = &thr->catchstack[idx];
if (DUK_CAT_HAS_LEXENV_ACTIVE(p)) {
DUK_DDDPRINT("unwinding catchstack idx %d: lexical environment active", idx);
/* FIXME: Here we have a nasty dependency: the need to manipulate
* the callstack means that catchstack must always be unwound by
* the caller before unwinding the callstack. This should be fixed
* later.
*/
act = &thr->callstack[p->callstack_index];
DUK_ASSERT(act >= thr->callstack);
DUK_ASSERT(act < &thr->callstack[thr->callstack_top]);
DUK_ASSERT(act->lex_env != NULL); /* must be, since env was created */
DUK_DDDPRINT("callstack_index=%d, lex_env=%!iO", p->callstack_index, act->lex_env);
env = act->lex_env;
act->lex_env = env->prototype;
DUK_HOBJECT_DECREF(thr, env);
}
}
thr->catchstack_top = new_top;
/* note: any entries above the catchstack top are garbage and not zeroed */
}
void duk_hthread_catchstack_unwind(duk_hthread *thr, int new_top) {
int idx; /* FIXME: typing of 'new_top' and 'idx' */
DUK_DDDPRINT("unwind catchstack top of thread %p from %d to %d",
(void *) thr,
(thr != NULL ? (int) thr->catchstack_top : (int) -1),
(int) new_top);
DUK_ASSERT(thr);
DUK_ASSERT(thr->heap);
DUK_ASSERT(new_top >= 0);
DUK_ASSERT((duk_size_t) new_top <= thr->catchstack_top); /* cannot grow */
/*
* Since there are no references in the catcher structure,
* unwinding is quite simple. The only thing we need to
* look out for is popping a possible lexical environment
* established for an active catch clause.
*/
idx = thr->catchstack_top;
while (idx > new_top) {
duk_catcher *p;
duk_activation *act;
duk_hobject *env;
idx--;
DUK_ASSERT(idx >= 0);
DUK_ASSERT((duk_size_t) idx < thr->catchstack_size);
p = &thr->catchstack[idx];
if (DUK_CAT_HAS_LEXENV_ACTIVE(p)) {
DUK_DDDPRINT("unwinding catchstack idx %d, callstack idx %d, callstack top %d: lexical environment active",
idx, p->callstack_index, thr->callstack_top);
/* FIXME: Here we have a nasty dependency: the need to manipulate
* the callstack means that catchstack must always be unwound by
* the caller before unwinding the callstack. This should be fixed
* later.
*/
/* Note that multiple catchstack entries may refer to the same
* callstack entry.
*/
act = &thr->callstack[p->callstack_index];
DUK_ASSERT(act >= thr->callstack);
DUK_ASSERT(act < &thr->callstack[thr->callstack_top]);
DUK_DDDPRINT("catchstack_index=%d, callstack_index=%d, lex_env=%!iO",
(int) idx, (int) p->callstack_index, act->lex_env);
env = act->lex_env; /* current lex_env of the activation (created for catcher) */
DUK_ASSERT(env != NULL); /* must be, since env was created when catcher was created */
act->lex_env = env->prototype; /* prototype is lex_env before catcher created */
DUK_HOBJECT_DECREF(thr, env);
/* There is no need to decref anything else than 'env': if 'env'
* becomes unreachable, refzero will handle decref'ing its prototype.
*/
}
}
thr->catchstack_top = new_top;
/* note: any entries above the catchstack top are garbage and not zeroed */
}
