Canonical output ordering for constants.

pkg/compiler/lib/src/js_emitter/startup_emitter/model_emitter.dart

 // Copyright (c) 2015, 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.
 
 library dart2js.js_emitter.startup_emitter.model_emitter;
 
 import 'dart:convert' show JsonEncoder;
 
 import 'package:js_runtime/shared/embedded_names.dart' show
     CLASS_FIELDS_EXTRACTOR,
@@ skipping 38 matching lines @@
 import '../../io/source_map_builder.dart' show
     SourceMapBuilder;
 import '../../js/js.dart' as js;
 import '../../js_backend/js_backend.dart' show
     JavaScriptBackend,
     Namer,
     ConstantEmitter;
 import '../../util/uri_extras.dart' show
     relativize;
 
+import '../constant_ordering.dart' show deepCompareConstants;
 import '../headers.dart';
 import '../js_emitter.dart' show
     NativeEmitter;
 
 import '../js_emitter.dart' show
     buildTearOffCode,
     NativeGenerator;
 import '../model.dart';
 
 part 'deferred_fragment_hash.dart';
@@ skipping 64 matching lines @@
     // Emit constant interceptors first. Constant interceptors for primitives
     // might be used by code that builds other constants.  See Issue 18173.
     if (a.isInterceptor != b.isInterceptor) {
       return a.isInterceptor ? -1 : 1;
     }
 
     // Sorting by the long name clusters constants with the same constructor
     // which compresses a tiny bit better.
     int r = namer.constantLongName(a).compareTo(namer.constantLongName(b));
     if (r != 0) return r;
-    // Resolve collisions in the long name by using the constant name (i.e. JS
-    // name) which is unique.
-    return namer.constantName(a).compareTo(namer.constantName(b));
+
+    // Resolve collisions in the long name by using a structural order.
+    return deepCompareConstants(a, b);
   }
 
   js.Expression generateStaticClosureAccess(FunctionElement element) {
     return js.js('#.#()',
         [namer.globalObjectFor(element), namer.staticClosureName(element)]);
   }
 
   js.Expression generateConstantReference(ConstantValue value) {
     if (value.isFunction) {
       FunctionConstantValue functionConstant = value;
@@ skipping 258 matching lines @@
     // Json does not support comments, so we embed the explanation in the
     // data.
     mapping["_comment"] = "This mapping shows which compiled `.js` files are "
         "needed for a given deferred library import.";
     mapping.addAll(compiler.deferredLoadTask.computeDeferredMap());
     compiler.outputProvider(compiler.deferredMapUri.path, 'deferred_map')
       ..add(const JsonEncoder.withIndent("  ").convert(mapping))
       ..close();
   }
 }