merge verify_deps into debug_info

bin/debug_info.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.
 
 /// Tool used mainly by dart2js developers to debug the generated info and check
 /// that it is consistent and that it covers all the data we expect it to cover.
 library dart2js_info.bin.debug_info;
 
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:dart2js_info/info.dart';
 import 'package:dart2js_info/src/graph.dart';
+import 'package:dart2js_info/src/util.dart';
 
 main(args) {
   if (args.length < 1) {
     print('usage: dart tool/debug_info.dart path-to-info.json '
         '[--show-library libname]');
     exit(1);
   }
 
   var filename = args[0];
   var json = JSON.decode(new File(filename).readAsStringSync());
   var info = new AllInfoJsonCodec().decode(json);
   var debugLibName;
 
   if (args.length > 2 && args[1] == '--show-library') {
     debugLibName = args[2];
   }
 
+  validateSize(info, debugLibName);
+  compareGraphs(info);
+  verifyDeps(info);
+}
+
+/// Validates that codesize of elements adds up to total codesize.
+validateSize(AllInfo info, String debugLibName) {
   // Gather data from visiting all info elements.
   var tracker = new _SizeTracker(debugLibName);
   info.accept(tracker);
 
   // Validate that listed elements include elements of each library.
   Set<Info> listed = new Set()..addAll(info.functions)..addAll(info.fields);
   // For our sanity we do some validation of dump-info invariants
   var diff1 = listed.difference(tracker.discovered);
   var diff2 = tracker.discovered.difference(listed);
   if (diff1.length == 0 || diff2.length == 0) {
@@ skipping 19 matching lines @@
     var percent =
         ((realTotal - accounted) * 100 / realTotal).toStringAsFixed(2);
     _fail('$percent% size missing: $accounted (all libs + consts) '
         '< $realTotal (total)');
   }
   var missingTotal = tracker.missing.values.fold(0, (a, b) => a + b);
   if (missingTotal > 0) {
     var percent = (missingTotal * 100 / realTotal).toStringAsFixed(2);
     _fail('$percent% size missing in libraries (sum of elements > lib.size)');
   }
-
-  // Validate dependency data.
-  compareGraphs(info);
 }
 
 class _SizeTracker extends RecursiveInfoVisitor {
   /// A library name for which to print debugging information (if not null).
   final String _debugLibName;
 
   _SizeTracker(this._debugLibName);
 
   /// [FunctionInfo]s and [FieldInfo]s transitively reachable from [LibraryInfo]
   /// elements.
@@ skipping 118 matching lines @@
     }
   }
 }
 
 class _State {
   int _count = 0;
   int _totalSize = 0;
   int _bodySize = 0;
 }
 
+/// Validates that both forms of dependency information match.
 void compareGraphs(AllInfo info) {
   var g1 = new EdgeListGraph<Info>();
   var g2 = new EdgeListGraph<Info>();
   for (var f in info.functions) {
     g1.addNode(f);
     for (var g in f.uses) {
       g1.addEdge(f, g.target);
     }
     g2.addNode(f);
     if (info.dependencies[f] != null) {
@@ skipping 30 matching lines @@
   info.fields.forEach(_sameEdges);
   if (inUsesNotInDependencies == 0 && inDependenciesNotInUses == 0) {
     _pass('dependency data is consistent');
   } else {
     _fail('inconsistencies in dependency data:\n'
         '   $inUsesNotInDependencies edges missing from "dependencies" graph\n'
         '   $inDependenciesNotInUses edges missing from "uses" graph');
   }
 }
 
+// Validates that all elements are reachable from `main` in the dependency
+// graph.
+verifyDeps(AllInfo info) {
+  var graph = graphFromInfo(info);
+  var entrypoint = info.program.entrypoint;
+  var reachables = new Set.from(graph.preOrder(entrypoint));
+
+  var functionsAndFields = []..addAll(info.functions)..addAll(info.fields);
+  var unreachables =
+      functionsAndFields.where((func) => !reachables.contains(func));
+  if (unreachables.isNotEmpty) {
+    _fail('${unreachables.length} elements are unreachable from the '
+        'entrypoint');
+  } else {
+    _pass('all elements are reachable from the entrypoint');
+  }
+}
+
 _pass(String msg) => print('\x1b[32mPASS\x1b[0m: $msg');
 _fail(String msg) => print('\x1b[31mFAIL\x1b[0m: $msg');