- * This pass is to remove these fake functions from the parse tree. We take
- * care to avoid turning invalid things like ((int)) into valid things like
- * (int) by observing that the only valid function declarators that appear
- * in these "fake" parentheses are those that have a non-null child declarator
- * (for instance, int ((*)(int)) *or* those that will be eliminated by the
- * simplify_functions pass.
+ * There are two cases:
+ *
+ * - For (), the parser emits a parameter with a lone null declarator.
+ * This fake parameter simply gets deleted, leaving us with a normal
+ * function declarator with an empty identifier list.
+ *
+ * - Otherwise, the parameter's outermost declarator is not null. The
+ * function itself is deleted, replaced in the parse tree with the
+ * fake parameter's declarator.
+ *
+ * Repeating until there no fake parameters, this reduction transforms, for
+ * example, "(((x)))" into "(x)", an abstract function declarator. The result
+ * is then subject to the function simplification step, which will turn "(x)"
+ * into x (declaring an identifier).