frog: check that const constructors have potentially const initializers. Also

frog/member.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /** A formal parameter to a [Method]. */
 class Parameter {
   FormalNode definition;
   Member method;
 
   String name;
@@ skipping 1125 matching lines @@
             for (var fname in value.fields.getKeys()) {
               fields[fname] = value.fields[fname];
             }
           }
         } else {
           // Normal field initializer assignment.
           BinaryExpression assign = init;
           var x = assign.x; // DotExpression or VarExpression
           var fname = x.name.name;
           var val = generator.visitValue(assign.y);
+          if (!val.isConst) {
+            world.error('invalid non-const initializer in const constructor',
+                assign.y.span);

[jimhug, 2011/12/12 18:14:30]

Could this be val.span instead?  It doesn't really matter right now, I'm just
thinking a little ahead to richer Values and more analysis with them.

[Siggi Cherem (dart-lang), 2011/12/12 18:20:55]

For some reason in this case they are not the same - we need to look more into
it. In the new test, assing.y.span is the whole expression "1.toString()", but
val.span is just the method call portion ("toString").

+          }
           fields[fname] = val;
         }
       }
 
       generator._popBlock();
     }
 
     // Add default values only if they weren't overriden in the constructor.
     for (var f in declaringType.members.getValues()) {
-      if (f is FieldMember && !f.isStatic && f.value != null
-          && !fields.containsKey(f.name)) {
-        fields[f.name] = f.computeValue();
+      if (f is FieldMember && !f.isStatic && !fields.containsKey(f.name)) {
+        if (!f.isFinal) {
+          world.error('const class "${declaringType.name}" has non-final '
+              + 'field "${f.name}"', f.span);
+        }
+        if (f.value != null) {
+          fields[f.name] = f.computeValue();
+        }
       }
     }
 
     return world.gen.globalForConst(
         new ConstObjectValue(target.type, fields, code, node.span),
         args.values);
   }
 
 
   Value _invokeBuiltin(MethodGenerator context, Node node, Value target,
@@ skipping 601 matching lines @@
   }
 
   void forEach(void f(Member member)) {
     factories.forEach((_, Map constructors) {
       constructors.forEach((_, Member member) {
         f(member);
       });
     });
   }
 }