[PATCH] vbscript: Handle recursive call.

[Robert Wilhelm]

Hi Jacek,

thank you for the review and the testcase.

It seems it cannot be solved in interpreter alone, because bytecode for y=f and y=f() is same in following example.

I would be glad on advice how to fix this...

Thanks,
Robert

function f
   y = f   ' y =Empty
   y = f() ' recursive call
end function
call f()

00f4:trace:vbscript_disas:dump_code 1:	icallv	L"f"	0
00f4:trace:vbscript_disas:dump_code 2:	catch	2	0
00f4:trace:vbscript_disas:dump_code 3:	ret
00f4:trace:vbscript_disas:dump_code 4:	icall	L"f"	0
00f4:trace:vbscript_disas:dump_code 5:	assign_ident	L"y"	0
00f4:trace:vbscript_disas:dump_code 6:	catch	6	0
00f4:trace:vbscript_disas:dump_code 7:	icall	L"f"	0
00f4:trace:vbscript_disas:dump_code 8:	assign_ident	L"y"	0
00f4:trace:vbscript_disas:dump_code 9:	catch	9	0
00f4:trace:vbscript_disas:dump_code 10:	ret



On Thu, 2021-09-23 at 14:39 +0200, Jacek Caban wrote:
> Hi Robert,
>
> Sorry for the delay.
>
> On 9/16/21 10:25 PM, Robert Wilhelm wrote:
> >       if((ctx->func->type == FUNC_FUNCTION || ctx->func->type == FUNC_PROPGET)
> > -       && !wcsicmp(name, ctx->func->name)) {
> > +       && !wcsicmp(name, ctx->func->name)
> > +       /* you must not use return value for recursive call */
> > +       && ((invoke_type != VBDISP_CALLGET) || ((invoke_type == VBDISP_CALLGET) && ( V_VT(&ctx->ret_val) == VT_DISPATCH)))) {
>
>
> I experimented a bit with this, see attached test. It seems that we
> should use the current function even if ret_val is modified and not an
> object.
>
>
> Thanks,
>
> Jacek
>