It is possible for one rule to depend on the success or failure of another rule. There are four possibilities:

• X: The rule is only applied to bindings that X succeeded on. In the following:

@foo_found disable all@
identifier foo;
@@
foo(...)
{
 <+...
  {
  ...
  return;
  }
 ...+>
}

@bar depends on foo_found@
@@
-bar()

any instances of the call bar() will only be removed when a match has occurred against a function called foo.

• !X: The current rule only applies to bindings that X failed on.

• ever X: The current rule only applies if there are some bindings that X succeeded on.

• never X: The rule is only applied if there are no bindings in the current source file that X succeeded on. The following pattern:

@stop_matches@
identifier lock_out
@@

lock_out

@foo_2_bar depends on never stop_matches@
@@

-foo();
+bar();

will only replace foo with bar if the source file does not contain any instance of an identifier named lock_out.