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 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 /*

  * Detect classes that should have overridden members of their parent

  * classes but didn't.

  *

  * Example:

  *

  * struct S {

  *   virtual NS_MUST_OVERRIDE void f();

  *   virtual void g();

  * };

  *

  * struct A : S { virtual void f(); }; // ok

  * struct B : S { virtual NS_MUST_OVERRIDE void f(); }; // also ok

  *

  * struct C : S { virtual void g(); }; // ERROR: must override f()

  * struct D : S { virtual void f(int); }; // ERROR: different overload

  * struct E : A { }; // ok: A's definition of f() is good for subclasses

  * struct F : B { }; // ERROR: B's definition of f() is still must-override

  *

  * We don't care if you define the method or not.

  */

 function get_must_overrides(cls)

 {

   let mos = {};

   for each (let base in cls.bases)

     for each (let m in base.type.members)

       if (hasAttribute(m, 'NS_must_override')) 

        mos[m.shortName] = m;

   return mos;

 }

 function process_type(t)

 {

   if (t.isIncomplete || (t.kind != 'class' && t.kind != 'struct'))

     return;

   let mos = get_must_overrides(t);

   for each (let m in t.members) {

     let mos_m = mos[m.shortName]

     if (mos_m && signaturesMatch(mos_m, m))

       delete mos[m.shortName];

   }

   for each (let u in mos)

     error(t.kind + " " + t.name + " must override " + u.name, t.loc);

 }