The distinction is in the syntax.

    int main()
    {
       foo(bar);
       foo * bar;
    }

If foo is a typedef, these are variable declarations, otherwise the first is a function call and the second multiplication (syntactically). These are different kinds of things that would normally be up to the parser to figure out (rather than semantic analysis later). These are well-known ambiguities relating to typedefs in C (well-known to compiler authors, at any rate).

The situation doesn't come up in Pascal because variables go in the var block (starting with the 'var' keyword) and functions and procedures both start with keywords ('function' and 'procedure').