A question about TYPE_ARG_TYPES

[Ian Lance Taylor]

Kazu Hirata <kazu@codesourcery.com> writes:

> I keep finding places in GCC sources that check whether a member of
> TYPE_ARG_TYPES is 0.  For example,
> 
>   for (link = TYPE_ARG_TYPES (function_or_method_type);
>        link && TREE_VALUE (link);
>        link = TREE_CHAIN (link))
>     gen_type_die (TREE_VALUE (link), context_die);
> 
> Notice that TREE_VALUE (link) is part of the loop condition.
> 
> Now, do we ever allow a NULL in TYPE_ARG_TYPES?  If so, what does that
> mean?  My guess is that soneone was trying to be cautious about
> encountering a NULL in TYPE_ARG_TYPES.  (If that's the case, we should
> be using gcc_assert instead.)

Just guessing here, but what happens with an old-style function
definition in C?

void f();

Ian