Intentional usage of old style function declarations?

Hi,

We have a bunch of callbacks that use old-style C function
declarations. I.e. functions with empty parens allowing all types of
data being passed:

E.g.
extern bool expression_tree_walker(Node *node, bool (*walker) (),
void *context);
extern Node *expression_tree_mutator(Node *node, Node *(*mutator) (),
void *context);

I find that to be fairly ugly. Was that intentional? Fixing it would
imply adding a fair number of (Node *) casts as there's suddenly actual
parameter type checking done.

Greetings,

Andres Freund