Re: [Swig-devel] Swig-devel Digest, Vol 57, Issue 12

[Stefan Z. <ste...@am...>]

> When -fastdispatch is used, it can produce unreachable code in dispatch functions where one of the overloaded function signatures has varargs.  For example, this interface:
>
> %inline %{
> extern int func (int i, double j);
> extern int func (const char *fmt, ...);
> %}
>
> ... produces this dispatch code:
>
>   if (argc >= 1) {
>     return _wrap_func__SWIG_1(self, args);
>   }
>   if (argc == 2) {
>     return _wrap_func__SWIG_0(self, args);
>   }
>
> With this patch, fast dispatch is automatically disabled for any overloaded function that has varargs in one of its signatures.
>
>
> ----------------------------------------------------------------------
>
> >Comment By: William Fulton (wsfulton)
> Date: 2011-02-18 21:26
>
> Message:
> Thanks. Instead I've fixed the problem so that varargs can still be used in
> overloaded functions with -fastdispatch. Tested with the python test-suite
> with -fastdispatch set.
>
> ----------------------------------------------------------------------

Hmm... looks like your fix will only dispatch to the varargs method if it's
called with only the minimum number of arguments, i.e., no variable-length
arguments are used.

In some sense, that's probably a good idea, because swig doesn't do anything
useful with the variable-length arguments.  But it is a change in swig's
behavior, and it probably ought to be documented somewhere.

Stefan