michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /*
michael@0:  * Detect classes that should have overridden members of their parent
michael@0:  * classes but didn't.
michael@0:  *
michael@0:  * Example:
michael@0:  *
michael@0:  * struct S {
michael@0:  *   virtual NS_MUST_OVERRIDE void f();
michael@0:  *   virtual void g();
michael@0:  * };
michael@0:  *
michael@0:  * struct A : S { virtual void f(); }; // ok
michael@0:  * struct B : S { virtual NS_MUST_OVERRIDE void f(); }; // also ok
michael@0:  *
michael@0:  * struct C : S { virtual void g(); }; // ERROR: must override f()
michael@0:  * struct D : S { virtual void f(int); }; // ERROR: different overload
michael@0:  * struct E : A { }; // ok: A's definition of f() is good for subclasses
michael@0:  * struct F : B { }; // ERROR: B's definition of f() is still must-override
michael@0:  *
michael@0:  * We don't care if you define the method or not.
michael@0:  */
michael@0: 
michael@0: function get_must_overrides(cls)
michael@0: {
michael@0:   let mos = {};
michael@0:   for each (let base in cls.bases)
michael@0:     for each (let m in base.type.members)
michael@0:       if (hasAttribute(m, 'NS_must_override')) 
michael@0:        mos[m.shortName] = m;
michael@0: 
michael@0:   return mos;
michael@0: }
michael@0: 
michael@0: function process_type(t)
michael@0: {
michael@0:   if (t.isIncomplete || (t.kind != 'class' && t.kind != 'struct'))
michael@0:     return;
michael@0: 
michael@0:   let mos = get_must_overrides(t);
michael@0:   for each (let m in t.members) {
michael@0:     let mos_m = mos[m.shortName]
michael@0:     if (mos_m && signaturesMatch(mos_m, m))
michael@0:       delete mos[m.shortName];
michael@0:   }
michael@0: 
michael@0:   for each (let u in mos)
michael@0:     error(t.kind + " " + t.name + " must override " + u.name, t.loc);
michael@0: }