DUK_EXTERNAL duk_int_t duk_pcall(duk_context *ctx, duk_idx_t nargs) {
duk_hthread *thr = (duk_hthread *) ctx;
duk_small_uint_t call_flags;
duk_idx_t idx_func;
duk_int_t rc;
DUK_ASSERT_CTX_VALID(ctx);
DUK_ASSERT(thr != NULL);
idx_func = duk_get_top(ctx) - nargs - 1; /* must work for nargs <= 0 */
if (idx_func < 0 || nargs < 0) {
/* We can't reliably pop anything here because the stack input
* shape is incorrect. So we throw an error; if the caller has
* no catch point for this, a fatal error will occur. Another
* alternative would be to just return an error. But then the
* stack would be in an unknown state which might cause some
* very hard to diagnose problems later on. Also note that even
* if we did not throw an error here, the underlying call handler
* might STILL throw an out-of-memory error or some other internal
* fatal error.
*/
DUK_ERROR_TYPE_INVALID_ARGS(thr);
return DUK_EXEC_ERROR; /* unreachable */
}
/* awkward; we assume there is space for this */
duk_push_undefined(ctx);
duk_insert(ctx, idx_func + 1);
call_flags = 0; /* respect reclimit, not constructor */
rc = duk_handle_call_protected(thr, /* thread */
nargs, /* num_stack_args */
call_flags); /* call_flags */
return rc;
}
DUK_EXTERNAL duk_int_t duk_pcall_method(duk_context *ctx, duk_idx_t nargs) {
duk_hthread *thr = (duk_hthread *) ctx;
duk_small_uint_t call_flags;
duk_idx_t idx_func;
duk_int_t rc;
DUK_ASSERT_CTX_VALID(ctx);
DUK_ASSERT(thr != NULL);
idx_func = duk_get_top(ctx) - nargs - 2; /* must work for nargs <= 0 */
if (idx_func < 0 || nargs < 0) {
/* See comments in duk_pcall(). */
DUK_ERROR_TYPE_INVALID_ARGS(thr);
return DUK_EXEC_ERROR; /* unreachable */
}
call_flags = 0; /* respect reclimit, not constructor */
rc = duk_handle_call_protected(thr, /* thread */
nargs, /* num_stack_args */
call_flags); /* call_flags */
return rc;
}
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 ] */
}