dart2js: add visitors and parsing support to infos

pkg/compiler/lib/src/dump_info.dart

 // Copyright (c) 2013, 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 dump_info;
 
 import 'dart:convert'
     show HtmlEscape, JsonEncoder, StringConversionSink, ChunkedConversionSink;
 
 import 'elements/elements.dart';
@@ skipping 461 matching lines @@
       for (Selection selection in uses) {
         // Don't register dart2js builtin functions that are not recorded.
         Info useInfo = infoCollector._elementToInfo[selection.selectedElement];
         if (useInfo == null) continue;
         info.uses.add(new DependencyInfo(useInfo, '${selection.mask}'));
       }
     }
 
     // Track dependencies that come from inlining.
     for (Element element in inlineMap.keys) {
-      FunctionInfo functionInfo = infoCollector._elementToInfo[element];
-      if (functionInfo == null) continue;
-      for (Element held in inlineMap[element]) {
-        Info heldInfo = infoCollector._elementToInfo[held];
-        if (heldInfo == null) continue;
-        functionInfo.uses.add(new DependencyInfo(heldInfo, 'inlined'));
+      Info outerInfo = infoCollector._elementToInfo[element];

[Siggi Cherem (dart-lang), 2015/08/11 16:16:43]

oops - I noticed this error while testing things out in checked mode, and so I
included it with this same CL without realizing it. Turns out this added a
warning to dart2js, so I sent a follow up CL fixing it.

+      if (outerInfo == null) continue;
+      for (Element inlined in inlineMap[element]) {
+        Info inlinedInfo = infoCollector._elementToInfo[inlined];
+        if (inlinedInfo == null) continue;
+        outerInfo.uses.add(new DependencyInfo(inlinedInfo, 'inlined'));
       }
     }
 
     AllInfo result = infoCollector.result;
     result.deferredFiles = compiler.deferredLoadTask.computeDeferredMap();
     stopwatch.stop();
     result.program = new ProgramInfo(
         size: _programSize,
         dart2jsVersion: compiler.hasBuildId ? compiler.buildId : null,
         compilationMoment: new DateTime.now(),
         compilationDuration: compiler.totalCompileTime.elapsed,
         toJsonDuration: stopwatch.elapsedMilliseconds,
         dumpInfoDuration: this.timing,
         noSuchMethodEnabled: compiler.backend.enabledNoSuchMethod,
         minified: compiler.enableMinification);
 
     ChunkedConversionSink<Object> sink = encoder.startChunkedConversion(
         new StringConversionSink.fromStringSink(buffer));
     sink.add(result.toJson());
     compiler.reportInfo(NO_LOCATION_SPANNABLE, MessageKind.GENERIC, {
       'text': "View the dumped .info.json file at "
           "https://dart-lang.github.io/dump-info-visualizer"
     });
   }
 }