DUK_INTERNAL void duk_hobject_run_finalizer(duk_hthread *thr, duk_hobject *obj) {
duk_context *ctx = (duk_context *) thr;
duk_ret_t rc;
#if defined(DUK_USE_ASSERTIONS)
duk_idx_t entry_top;
#endif
DUK_DDD(DUK_DDDPRINT("running object finalizer for object: %p", (void *) obj));
DUK_ASSERT(thr != NULL);
DUK_ASSERT(ctx != NULL);
DUK_ASSERT(obj != NULL);
DUK_ASSERT_VALSTACK_SPACE(thr, 1);
#if defined(DUK_USE_ASSERTIONS)
entry_top = duk_get_top(ctx);
#endif
/*
* Get and call the finalizer. All of this must be wrapped
* in a protected call, because even getting the finalizer
* may trigger an error (getter may throw one, for instance).
*/
DUK_ASSERT(!DUK_HEAPHDR_HAS_READONLY((duk_heaphdr *) obj));
if (DUK_HEAPHDR_HAS_FINALIZED((duk_heaphdr *) obj)) {
DUK_D(DUK_DPRINT("object already finalized, avoid running finalizer twice: %!O", obj));
return;
}
DUK_HEAPHDR_SET_FINALIZED((duk_heaphdr *) obj); /* ensure never re-entered until rescue cycle complete */
if (DUK_HOBJECT_HAS_EXOTIC_PROXYOBJ(obj)) {
/* This shouldn't happen; call sites should avoid looking up
* _Finalizer "through" a Proxy, but ignore if we come here
* with a Proxy to avoid finalizer re-entry.
*/
DUK_D(DUK_DPRINT("object is a proxy, skip finalizer call"));
return;
}
/* XXX: use a NULL error handler for the finalizer call? */
DUK_DDD(DUK_DDDPRINT("-> finalizer found, calling wrapped finalize helper"));
duk_push_hobject(ctx, obj); /* this also increases refcount by one */
rc = duk_safe_call(ctx, duk__finalize_helper, NULL /*udata*/, 0 /*nargs*/, 1 /*nrets*/); /* -> [... obj retval/error] */
DUK_ASSERT_TOP(ctx, entry_top + 2); /* duk_safe_call discipline */
if (rc != DUK_EXEC_SUCCESS) {
/* Note: we ask for one return value from duk_safe_call to get this
* error debugging here.
*/
DUK_D(DUK_DPRINT("wrapped finalizer call failed for object %p (ignored); error: %!T",
(void *) obj, (duk_tval *) duk_get_tval(ctx, -1)));
}
duk_pop_2(ctx); /* -> [...] */
DUK_ASSERT_TOP(ctx, entry_top);
}
DUK_LOCAL void duk__err_augment_user(duk_hthread *thr, duk_small_uint_t stridx_cb) {
duk_context *ctx = (duk_context *) thr;
duk_tval *tv_hnd;
duk_small_uint_t call_flags;
duk_int_t rc;
DUK_ASSERT(thr != NULL);
DUK_ASSERT(thr->heap != NULL);
DUK_ASSERT_DISABLE(stridx_cb >= 0); /* unsigned */
DUK_ASSERT(stridx_cb < DUK_HEAP_NUM_STRINGS);
if (DUK_HEAP_HAS_ERRHANDLER_RUNNING(thr->heap)) {
DUK_DD(DUK_DDPRINT("recursive call to error handler, ignore"));
return;
}
/*
* Check whether or not we have an error handler.
*
* We must be careful of not triggering an error when looking up the
* property. For instance, if the property is a getter, we don't want
* to call it, only plain values are allowed. The value, if it exists,
* is not checked. If the value is not a function, a TypeError happens
* when it is called and that error replaces the original one.
*/
DUK_ASSERT_VALSTACK_SPACE(thr, 4); /* 3 entries actually needed below */
/* [ ... errval ] */
if (thr->builtins[DUK_BIDX_DUKTAPE] == NULL) {
/* When creating built-ins, some of the built-ins may not be set
* and we want to tolerate that when throwing errors.
*/
DUK_DD(DUK_DDPRINT("error occurred when DUK_BIDX_DUKTAPE is NULL, ignoring"));
return;
}
tv_hnd = duk_hobject_find_existing_entry_tval_ptr(thr->heap,
thr->builtins[DUK_BIDX_DUKTAPE],
DUK_HTHREAD_GET_STRING(thr, stridx_cb));
if (tv_hnd == NULL) {
DUK_DD(DUK_DDPRINT("error handler does not exist or is not a plain value: %!T",
(duk_tval *) tv_hnd));
return;
}
DUK_DDD(DUK_DDDPRINT("error handler dump (callability not checked): %!T",
(duk_tval *) tv_hnd));
duk_push_tval(ctx, tv_hnd);
/* [ ... errval errhandler ] */
duk_insert(ctx, -2); /* -> [ ... errhandler errval ] */
duk_push_undefined(ctx);
duk_insert(ctx, -2); /* -> [ ... errhandler undefined(= this) errval ] */
/* [ ... errhandler undefined errval ] */
/*
* DUK_CALL_FLAG_IGNORE_RECLIMIT causes duk_handle_call() to ignore C
* recursion depth limit (and won't increase it either). This is
* dangerous, but useful because it allows the error handler to run
* even if the original error is caused by C recursion depth limit.
*
* The heap level DUK_HEAP_FLAG_ERRHANDLER_RUNNING is set for the
* duration of the error handler and cleared afterwards. This flag
* prevents the error handler from running recursively. The flag is
* heap level so that the flag properly controls even coroutines
* launched by an error handler. Since the flag is heap level, it is
* critical to restore it correctly.
*
* We ignore errors now: a success return and an error value both
* replace the original error value. (This would be easy to change.)
*/
DUK_ASSERT(!DUK_HEAP_HAS_ERRHANDLER_RUNNING(thr->heap)); /* since no recursive error handler calls */
DUK_HEAP_SET_ERRHANDLER_RUNNING(thr->heap);
call_flags = DUK_CALL_FLAG_IGNORE_RECLIMIT; /* ignore reclimit, not constructor */
rc = duk_handle_call_protected(thr,
1, /* num args */
call_flags); /* call_flags */
DUK_UNREF(rc); /* no need to check now: both success and error are OK */
DUK_ASSERT(DUK_HEAP_HAS_ERRHANDLER_RUNNING(thr->heap));
DUK_HEAP_CLEAR_ERRHANDLER_RUNNING(thr->heap);
/* [ ... errval ] */
}