Add source mappings and inlined Dart code to diff_view.

tests/compiler/dart2js/sourcemaps/diff_view.dart

 // Copyright (c) 2016, 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 sourcemap.diff_view;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
+import 'package:compiler/src/common.dart';
 import 'package:compiler/src/commandline_options.dart';
 import 'package:compiler/src/diagnostics/invariant.dart';
 import 'package:compiler/src/elements/elements.dart';
 import 'package:compiler/src/io/position_information.dart';
 import 'package:compiler/src/io/source_information.dart';
 import 'package:compiler/src/io/source_file.dart';
 import 'package:compiler/src/js/js.dart' as js;
 import 'package:compiler/src/js/js_debug.dart';
 
 import 'diff.dart';
 import 'html_parts.dart';
 import 'js_tracer.dart';
 import 'output_structure.dart';
 import 'sourcemap_helper.dart';
 import 'sourcemap_html_helper.dart';
 import 'trace_graph.dart';
 
-const String WITH_SOURCE_INFO_STYLE = 'border: solid 1px #FF8080;';
-const String WITHOUT_SOURCE_INFO_STYLE = 'background-color: #8080FF;';
-const String ADDITIONAL_SOURCE_INFO_STYLE = 'border: solid 1px #80FF80;';
-const String UNUSED_SOURCE_INFO_STYLE = 'border: solid 1px #8080FF;';
-
 main(List<String> args) async {
   DEBUG_MODE = true;
   String out = 'out.js.diff_view.html';
   String filename;
   List<String> currentOptions = [];
   List<List<String>> optionSegments = [currentOptions];
   Map<int, String> loadFrom = {};
   Map<int, String> saveTo = {};
   int argGroup = 0;
-  bool addAnnotations = true;
+  bool showAnnotations = true;
   for (String arg in args) {
     if (arg == '--') {
       currentOptions = [];
       optionSegments.add(currentOptions);
       argGroup++;
     } else if (arg == '-h') {
-      addAnnotations = false;
+      showAnnotations = false;
       print('Hiding annotations');
     } else if (arg == '-l') {
       loadFrom[argGroup] = 'out.js.diff$argGroup.json';
     } else if (arg.startsWith('--load=')) {
       loadFrom[argGroup] = arg.substring('--load='.length);
     } else if (arg == '-s') {
       saveTo[argGroup] = 'out.js.diff$argGroup.json';
     } else if (arg.startsWith('--save=')) {
       saveTo[argGroup] = arg.substring('--save='.length);
     } else if (arg.startsWith('-o')) {
@@ skipping 25 matching lines @@
 
   SourceFileManager sourceFileManager = new IOSourceFileManager(Uri.base);
   List<AnnotatedOutput> outputs = <AnnotatedOutput>[];
   for (int i = 0; i < 2; i++) {
     AnnotatedOutput output;
     if (loadFrom.containsKey(i)) {
       output = AnnotatedOutput.loadOutput(loadFrom[i]);
     } else {
       print('Compiling ${options[i].join(' ')} $filename');
       CodeLinesResult result = await computeCodeLines(
-          options[i], filename, addAnnotations: addAnnotations);
+          options[i], filename);
       OutputStructure structure = OutputStructure.parse(result.codeLines);
       computeEntityCodeSources(result, structure);
       output = new AnnotatedOutput(
           filename,
           options[i],
           structure,
           result.coverage.getCoverageReport());
     }
     if (saveTo.containsKey(i)) {
       AnnotatedOutput.saveOutput(output, saveTo[i]);
     }
     outputs.add(output);
   }
 
   List<DiffBlock> blocks = createDiffBlocks(
       outputs.map((o) => o.structure).toList(),
       sourceFileManager);
 
   outputDiffView(
-      out, outputs, blocks, addAnnotations: addAnnotations);
+      out, outputs, blocks,
+      showMarkers: showAnnotations,
+      showSourceMapped: showAnnotations);
 }
 
 /// Attaches [CodeSource]s to the entities in [structure] using the
 /// element-to-offset in [result].
 void computeEntityCodeSources(
     CodeLinesResult result, OutputStructure structure) {
   result.elementMap.forEach((int line, Element element) {
     OutputEntity entity = structure.getEntityForLine(line);
     if (entity != null) {
       entity.codeSource = codeSourceFromElement(element);
     }
   });
 }
 
+class CodeLineAnnotationJsonStrategy implements JsonStrategy {
+  const CodeLineAnnotationJsonStrategy();
+
+  Map encodeAnnotation(Annotation annotation) {
+    CodeLineAnnotation data = annotation.data;
+    return {
+      'id': annotation.id,
+      'codeOffset': annotation.codeOffset,
+      'title': annotation.title,
+      'data': data.toJson(this),
+    };
+  }
+
+  Annotation decodeAnnotation(Map json) {
+    return new Annotation(
+        json['id'],
+        json['codeOffset'],
+        json['title'],
+        data: CodeLineAnnotation.fromJson(json['data'], this));
+  }
+
+  @override
+  decodeLineAnnotation(json) {
+    if (json != null) {
+      return CodeSource.fromJson(json);
+    }
+    return null;
+  }
+
+  @override
+  encodeLineAnnotation(CodeSource lineAnnotation) {
+    if (lineAnnotation != null) {
+      return lineAnnotation.toJson();
+    }
+    return null;
+  }
+}
+
 /// The structured output of a compilation.
 class AnnotatedOutput {
   final String filename;
   final List<String> options;
   final OutputStructure structure;
   final String coverage;
 
   AnnotatedOutput(this.filename, this.options, this.structure, this.coverage);
 
   List<CodeLine> get codeLines => structure.lines;
 
   Map toJson() {
     return {
       'filename': filename,
       'options': options,
-      'structure': structure.toJson(),
+      'structure': structure.toJson(const CodeLineAnnotationJsonStrategy()),
       'coverage': coverage,
     };
   }
 
   static AnnotatedOutput fromJson(Map json) {
     String filename = json['filename'];
     List<String> options = json['options'];
-    OutputStructure structure = OutputStructure.fromJson(json['structure']);
+    OutputStructure structure = OutputStructure.fromJson(
+        json['structure'], const CodeLineAnnotationJsonStrategy());
     String coverage = json['coverage'];
     return new AnnotatedOutput(filename, options, structure, coverage);
   }
 
   static AnnotatedOutput loadOutput(filename) {
     AnnotatedOutput output = AnnotatedOutput.fromJson(
         JSON.decode(new File(filename).readAsStringSync()));
     print('Output loaded from $filename');
     return output;
   }
 
   static void saveOutput(AnnotatedOutput output, String filename) {
     if (filename != null) {
       new File(filename).writeAsStringSync(
           const JsonEncoder.withIndent('  ').convert(output.toJson()));
       print('Output saved in $filename');
     }
   }
 }
 
 void outputDiffView(
     String out,
     List<AnnotatedOutput> outputs,
     List<DiffBlock> blocks,
-    {bool addAnnotations: true}) {
+    {bool showMarkers: true,
+     bool showSourceMapped: true}) {
   assert(outputs[0].filename == outputs[1].filename);
   bool usePre = true;
 
   StringBuffer sb = new StringBuffer();
   sb.write('''
 <html>
 <head>
 <title>Diff for ${outputs[0].filename}</title>
 <style>
-.lineNumber {
+.${ClassNames.lineNumber} {
   font-size: smaller;
   color: #888;
 }
-.comment {
+.${ClassNames.comment} {
   font-size: smaller;
   color: #888;
   font-family: initial;
 }
-.header {
+.${ClassNames.header} {
   position: fixed;
   width: 100%;
   background-color: #FFFFFF;
   left: 0px;
   top: 0px;
   height: 42px;
   z-index: 1000;
 }
-.header-table {
+.${ClassNames.headerTable} {
   width: 100%;
   background-color: #400000;
   color: #FFFFFF;
   border-spacing: 0px;
 }
-.header-column {
-  width: 34%;
+.${ClassNames.headerColumn} {
 }
-.legend {
+.${ClassNames.legend} {
   padding: 2px;
 }
-.table {
+.${ClassNames.buttons} {
+  position: fixed;
+  right: 0px;
+  top: 0px;
+  width: 220px;
+  background-color: #FFFFFF;
+  border: 1px solid #C0C0C0;
+  z-index: 2000;
+}
+.${ClassNames.table} {
   position: absolute;
   left: 0px;
   top: 42px;
   width: 100%;
   border-spacing: 0px;
 }
-.cell {
-  max-width: 500px;
+.${ClassNames.cell}, 
+.${ClassNames.innerCell}, 
+.${ClassNames.originalDart}, 
+.${ClassNames.inlinedDart} {
   overflow-y: hidden;
   vertical-align: top;
-  border-top: 1px solid #F0F0F0;
-  border-left: 1px solid #F0F0F0;
 ''');
   if (usePre) {
     sb.write('''
   overflow-x: hidden;
   white-space: pre-wrap;
 ''');
   } else {
     sb.write('''
   overflow-x: hidden;
   padding-left: 100px;
   text-indent: -100px;
 ''');
   }
   sb.write('''
   font-family: monospace;
   padding: 0px;
 }
-.corresponding1 {
+.${ClassNames.cell} {
+  border-top: 1px solid #F0F0F0;
+  border-left: 1px solid #C0C0C0;
+}
+.${ClassNames.innerCell} {
+  /*border-top: 1px solid #F8F8F8;*/
+  width: 50%;
+  max-width: 250px;
+}
+.${ClassNames.corresponding(false)} {
   background-color: #FFFFE0;
 }
-.corresponding2 {
+.${ClassNames.corresponding(true)} {
   background-color: #EFEFD0;
 }
-.identical1 {
+.${ClassNames.identical(false)} {
   background-color: #E0F0E0;
 }
-.identical2 {
+.${ClassNames.identical(true)} {
   background-color: #C0E0C0;
 }
-.line {
+.${ClassNames.line} {
   padding-left: 7em;
   text-indent: -7em;
   margin: 0px;
 }
-.column0 {
+.${ClassNames.column(column_js0)} {
+  max-width: 500px;
+  width: 500px;
 }
-.column1 {
+.${ClassNames.column(column_js1)} {
+  max-width: 500px;
+  width: 500px;
 }
-.column2 {
+.${ClassNames.column(column_dart)} {
+  max-width: 300px;
+  width: 300px;
+}
+.${ClassNames.colored(0)} {
+  color: #FF0000;
+}
+.${ClassNames.colored(1)} {
+  color: #C0C000;
+}
+.${ClassNames.colored(2)} {
+  color: #008000;
+}
+.${ClassNames.colored(3)} {
+  color: #00C0C0;
+}
+.${ClassNames.withSourceInfo} {
+  border: solid 1px #FF8080;
+}
+.${ClassNames.withoutSourceInfo} {
+  background-color: #8080FF;
+}
+.${ClassNames.additionalSourceInfo} {
+  border: solid 1px #80FF80;
+}
+.${ClassNames.unusedSourceInfo} {
+  border: solid 1px #8080FF;
+}
+.${ClassNames.originalDart} {
+}
+.${ClassNames.inlinedDart} {
+}
+''');
+  for (int i = 0; i < HUE_COUNT; i++) {
+    sb.write('''
+.${ClassNames.sourceMappingIndex(i)} {
+  background-color: ${toColorCss(i)};
+}
+''');
+  }
+  sb.write('''
+.${ClassNames.sourceMapped} {
+  ${showSourceMapped ? '' : 'display: none;'}
+}
+.${ClassNames.sourceMapping} {
+  ${showSourceMapped ? '' : 'border: 0px;'}
+  ${showSourceMapped ? '' : 'background-color: transparent;'}
+}
+.${ClassNames.markers} {
+  ${showMarkers ? '' : 'display: none;'}
+}
+.${ClassNames.marker} {
+  ${showMarkers ? '' : 'border: 0px;'}
+  ${showMarkers ? '' : 'background-color: transparent;'}
 }
 </style>
+<script>
+function isChecked(name) {
+  var box = document.getElementById('box-' + name);
+  return box.checked;
+}
+function toggleDisplay(name) {
+  var checked = isChecked(name);
+  var styleSheet = document.styleSheets[0];
+  for (var index = 0; index < styleSheet.cssRules.length; index++) {
+    var cssRule = styleSheet.cssRules[index];
+    if (cssRule.selectorText == '.' + name) {
+      if (checked) {
+        cssRule.style.removeProperty('display');
+      } else {
+        cssRule.style.display = 'none';
+      }
+    }
+  }
+  return checked;
+}
+function toggle${ClassNames.sourceMapped}() {
+  var checked = toggleDisplay('${ClassNames.sourceMapped}');
+  toggleAnnotations(checked, '${ClassNames.sourceMapping}');
+}
+function toggle${ClassNames.markers}() {
+  var checked = toggleDisplay('${ClassNames.markers}');
+  toggleAnnotations(checked, '${ClassNames.marker}');
+}
+function toggleAnnotations(show, name) {
+  var styleSheet = document.styleSheets[0];
+  for (var index = 0; index < styleSheet.cssRules.length; index++) {
+    var cssRule = styleSheet.cssRules[index];
+    if (cssRule.selectorText == '.' + name) {
+      if (show) {
+        cssRule.style.removeProperty('border');
+        cssRule.style.removeProperty('background-color');
+      } else {
+        cssRule.style.border = '0px';
+        cssRule.style.backgroundColor = 'transparent';
+      }
+    }
+  }
+} 
+</script>
 </head>
 <body>''');
 
   sb.write('''
-<div class="header">
-<table class="header-table"><tr>
-<td class="header-column">[${outputs[0].options.join(',')}]</td>
-<td class="header-column">[${outputs[1].options.join(',')}]</td>
-<td class="header-column">Dart code</td>
-</tr></table>
-<div class="legend">
-  <span class="identical1">&nbsp;&nbsp;&nbsp;</span> 
-  <span class="identical2">&nbsp;&nbsp;&nbsp;</span>
+<div class="${ClassNames.header}">
+<div class="${ClassNames.legend}">
+  <span class="${ClassNames.identical(false)}">&nbsp;&nbsp;&nbsp;</span> 
+  <span class="${ClassNames.identical(true)}">&nbsp;&nbsp;&nbsp;</span>
   identical blocks
-  <span class="corresponding1">&nbsp;&nbsp;&nbsp;</span>
-  <span class="corresponding2">&nbsp;&nbsp;&nbsp;</span> 
+  <span class="${ClassNames.corresponding(false)}">&nbsp;&nbsp;&nbsp;</span>
+  <span class="${ClassNames.corresponding(true)}">&nbsp;&nbsp;&nbsp;</span> 
   corresponding blocks
 ''');
 
-  if (addAnnotations) {
-    sb.write('''
-  <span style="$WITH_SOURCE_INFO_STYLE">&nbsp;&nbsp;&nbsp;</span>
+  sb.write('''
+  <span class="${ClassNames.markers}">
+  <span class="${ClassNames.withSourceInfo}">&nbsp;&nbsp;&nbsp;</span>
   <span title="'offset with source information' means that source information 
 is available for an offset which is expected to have a source location 
 attached. This offset has source information as intended.">
   offset with source information</span>
-  <span style="$WITHOUT_SOURCE_INFO_STYLE">&nbsp;&nbsp;&nbsp;</span>
+  <span class="${ClassNames.withoutSourceInfo}">&nbsp;&nbsp;&nbsp;</span>
   <span title="'offset without source information' means that _no_ source 
 information is available for an offset which was expected to have a source 
 location attached. Source information must be found for this offset.">
   offset without source information</span>
-  <span style="$ADDITIONAL_SOURCE_INFO_STYLE">&nbsp;&nbsp;&nbsp;</span>
+  <span class="${ClassNames.additionalSourceInfo}">&nbsp;&nbsp;&nbsp;</span>
   <span title="'offset with unneeded source information' means that a source 
 location was attached to an offset which was _not_ expected to have a source
 location attached. The source location should be removed from this offset.">
   offset with unneeded source information</span>
-  <span style="$UNUSED_SOURCE_INFO_STYLE">&nbsp;&nbsp;&nbsp;</span>
+  <span class="${ClassNames.unusedSourceInfo}">&nbsp;&nbsp;&nbsp;</span>
   <span title="'offset with unused source information' means that source 
 information is available for an offset which is _not_ expected to have a source
 location attached. This source information _could_ be used by a parent AST node
 offset that is an 'offset without source information'."> 
   offset with unused source information</span>
+  </span>
+  <span class="${ClassNames.sourceMapped}">
 ''');
+  for (int i = 0; i < HUE_COUNT; i++) {
+    sb.write('''
+<span class="${ClassNames.sourceMappingIndex(i)}">&nbsp;&nbsp;</span>''');
   }
-
   sb.write('''
-</div></div>
-<table class="table">
+  <span title="JavaScript offsets and their corresponding Dart Code offset 
+as mapped through source-maps.">
+  mapped source locations</span>
+  </span>
 ''');
 
-  void addCell(String content) {
-    sb.write('''
-<td class="cell"><pre>
-''');
-    sb.write(content);
-    sb.write('''
-</pre></td>
-''');
-  }
 
   /// Marker to alternate output colors.
   bool alternating = false;
 
   List<HtmlPrintContext> printContexts = <HtmlPrintContext>[];
   for (int i = 0; i < 2; i++) {
     int lineNoWidth;
     if (outputs[i].codeLines.isNotEmpty) {
       lineNoWidth = '${outputs[i].codeLines.last.lineNo + 1}'.length;
     }
-    printContexts.add(new HtmlPrintContext(lineNoWidth: lineNoWidth));
+    printContexts.add(new HtmlPrintContext(
+        lineNoWidth: lineNoWidth,
+        getAnnotationData: getAnnotationData,
+        getLineData: getLineData));
   }
 
+  Set<DiffColumn> allColumns = new Set<DiffColumn>();
+  for (DiffBlock block in blocks) {
+    allColumns.addAll(block.columns);
+  }
+
+  List<DiffColumn> columns = [column_js0, column_js1, column_dart]
+      .where((c) => allColumns.contains(c)).toList();
+
+  sb.write('''
+</div>
+<table class="${ClassNames.headerTable}"><tr>''');
+  for (DiffColumn column in columns) {
+    sb.write('''
+<td class="${ClassNames.headerColumn} ${ClassNames.column(column)}">''');
+    if (column.type == 'js') {
+      sb.write('''[${outputs[column.index].options.join(',')}]''');
+    } else {
+      sb.write('''Dart code''');
+    }
+    sb.write('''</td>''');
+  }
+
+  sb.write('''
+</tr></table>
+</div>
+<table class="${ClassNames.table}">
+''');
+
   for (DiffBlock block in blocks) {
     String className;
     switch (block.kind) {
       case DiffKind.UNMATCHED:
-        className = 'cell';
+        className = '${ClassNames.cell}';
         break;
       case DiffKind.MATCHING:
-        className = 'cell corresponding${alternating ? '1' : '2'}';
+        className =
+            '${ClassNames.cell} ${ClassNames.corresponding(alternating)}';
         alternating = !alternating;
         break;
       case DiffKind.IDENTICAL:
-        className = 'cell identical${alternating ? '1' : '2'}';
+        className =
+            '${ClassNames.cell} ${ClassNames.identical(alternating)}';
         alternating = !alternating;
         break;
     }
     sb.write('<tr>');
-    for (int index = 0; index < 3; index++) {
-      sb.write('''<td class="$className column$index">''');
-      List<HtmlPart> lines = block.getColumn(index);
-      if (lines.isNotEmpty) {
-        for (HtmlPart line in lines) {
-          sb.write('<p class="line">');
-          if (index < printContexts.length) {
-            line.printHtmlOn(sb, printContexts[index]);
-          } else {
-            line.printHtmlOn(sb, new HtmlPrintContext());
-          }
-          sb.write('</p>');
-        }
+    for (DiffColumn column in columns) {
+      sb.write('''<td class="$className ${ClassNames.column(column)}">''');
+      HtmlPrintContext context = new HtmlPrintContext(
+          lineNoWidth: 4,
+          includeAnnotation: (Annotation annotation) {
+            CodeLineAnnotation data = annotation.data;
+            return data.annotationType == AnnotationType.WITH_SOURCE_INFO ||
+                   data.annotationType == AnnotationType.ADDITIONAL_SOURCE_INFO;
+          },
+          getAnnotationData: getAnnotationData,
+          getLineData: getLineData);
+      if (column.type == 'js') {
+        context = printContexts[column.index];
       }
+      block.printHtmlOn(column, sb, context);
       sb.write('''</td>''');
     }
     sb.write('</tr>');
   }
 
   sb.write('''</tr><tr>''');
 
-  addCell(outputs[0].coverage);
-  addCell(outputs[1].coverage);
+  for (DiffColumn column in columns) {
+    sb.write('''
+<td class="${ClassNames.cell} ${ClassNames.column(column)}"><pre>''');
+    if (column.type == 'js') {
+      sb.write(outputs[column.index].coverage);
+    }
+    sb.write('''</td>''');
+  }
 
   sb.write('''
 </table>
+<div class="${ClassNames.buttons}">
+<input type="checkbox" id="box-${ClassNames.column(column_js0)}" 
+  onclick="javascript:toggleDisplay('${ClassNames.column(column_js0)}')" 
+  checked>
+Left JavaScript code<br/>
+
+<input type="checkbox" id="box-${ClassNames.column(column_js1)}" 
+  onclick="javascript:toggleDisplay('${ClassNames.column(column_js1)}')" 
+  checked>
+Right JavaScript code<br/>
+
+<input type="checkbox" id="box-${ClassNames.column(column_dart)}" 
+  onclick="javascript:toggleDisplay('${ClassNames.column(column_dart)}')" 
+  checked>
+<span title="Show column with Dart code corresponding to the block.">
+Dart code</span><br/>
+
+<input type="checkbox" id="box-${ClassNames.inlinedDart}" 
+  onclick="javascript:toggleDisplay('${ClassNames.inlinedDart}')" checked>
+<span title="Show Dart code inlined into the block.">
+Inlined Dart code</span><br/>
+
+<input type="checkbox" id="box-${ClassNames.markers}" 
+  onclick="javascript:toggle${ClassNames.markers}()" 
+  ${showMarkers ? 'checked' : ''}>
+<span title="Show markers for JavaScript offsets with source information.">
+Source information markers</span><br/>
+
+<input type="checkbox" id="box-${ClassNames.sourceMapped}" 
+  onclick="javascript:toggle${ClassNames.sourceMapped}()" 
+  ${showSourceMapped ? 'checked' : ''}>
+<span title="Show line-per-line mappings of JavaScript to Dart code.">
+Source mapped Dart code</span><br/>
+</div>
 </body>
 </html>
 ''');
 
   new File(out).writeAsStringSync(sb.toString());
   print('Diff generated in $out');
 }
 
 class CodeLinesResult {
   final List<CodeLine> codeLines;
   final Coverage coverage;
   final Map<int, Element> elementMap;
   final SourceFileManager sourceFileManager;
-
-  CodeLinesResult(this.codeLines, this.coverage,
-      this.elementMap, this.sourceFileManager);
+  final CodeSources codeSources;
+
+  CodeLinesResult(
+      this.codeLines,
+      this.coverage,
+      this.elementMap,
+      this.sourceFileManager,
+      this.codeSources);
+}
+
+class CodeSources {
+  Map<Element, CodeSource> codeSourceMap = <Element, CodeSource>{};
+  Map<Uri, Map<Interval, CodeSource>> uriCodeSourceMap =
+      <Uri, Map<Interval, CodeSource>>{};
+
+  CodeSources(
+    SourceMapProcessor processor,
+    SourceMaps sourceMaps) {
+
+    CodeSource computeCodeSource(Element element) {
+      return codeSourceMap.putIfAbsent(element, () {
+        CodeSource codeSource = codeSourceFromElement(element);
+        if (codeSource.begin != null) {
+          Interval interval = new Interval(codeSource.begin, codeSource.end);
+          Map<Interval, CodeSource> intervals =
+              uriCodeSourceMap[codeSource.uri];
+          if (intervals == null) {
+            intervals = <Interval, CodeSource>{};
+            uriCodeSourceMap[codeSource.uri] = intervals;
+          } else {
+            for (Interval existingInterval in intervals.keys.toList()) {
+              if (existingInterval.contains(interval.from)) {
+                CodeSource existingCodeSource = intervals[existingInterval];
+                intervals.remove(existingInterval);
+                if (existingInterval.from < interval.from) {
+                  Interval preInterval = new Interval(
+                      existingInterval.from, interval.from);
+                  intervals[preInterval] = existingCodeSource;
+                }
+                if (interval.to < existingInterval.to) {
+                  Interval postInterval = new Interval(
+                      interval.to, existingInterval.to);
+                  intervals[postInterval] = existingCodeSource;
+                }
+              }
+            }
+          }
+          intervals[interval] = codeSource;
+        }
+        if (element is ClassElement) {
+          element.forEachLocalMember((Element member) {
+            codeSource.members.add(computeCodeSource(member));
+          });
+          element.implementation.forEachLocalMember((Element member) {
+            codeSource.members.add(computeCodeSource(member));
+          });
+        } else if (element is MemberElement) {
+          element.nestedClosures.forEach((Element closure) {
+            codeSource.members.add(computeCodeSource(closure));
+          });
+        }
+        return codeSource;
+      });
+    }
+
+    for (LibraryElement library in
+             sourceMaps.compiler.libraryLoader.libraries) {
+      library.forEachLocalMember(computeCodeSource);
+      library.implementation.forEachLocalMember(computeCodeSource);
+    }
+
+    uriCodeSourceMap.forEach((Uri uri, Map<Interval, CodeSource> intervals) {
+      List<Interval> sortedKeys = intervals.keys.toList()..sort(
+          (i1, i2) => i1.from.compareTo(i2.from));
+      Map<Interval, CodeSource> sortedintervals = <Interval, CodeSource>{};
+      sortedKeys.forEach((Interval interval) {
+        sortedintervals[interval] = intervals[interval];
+      });
+      uriCodeSourceMap[uri] = sortedintervals;
+    });
+  }
+
+  CodeSource sourceLocationToCodeSource(SourceLocation sourceLocation) {
+    Map<Interval, CodeSource> intervals =
+        uriCodeSourceMap[sourceLocation.sourceUri];
+    if (intervals == null) {
+      print('No code source for $sourceLocation(${sourceLocation.offset})');
+      print(' -- no intervals for ${sourceLocation.sourceUri}');
+      return null;
+    }
+    for (Interval interval in intervals.keys) {
+      if (interval.contains(sourceLocation.offset)) {
+        return intervals[interval];
+      }
+    }
+    print('No code source for $sourceLocation(${sourceLocation.offset})');
+    intervals.forEach((k, v) => print(' $k: ${v.name}'));
+    return null;
+  }
 }
 
 /// Compute [CodeLine]s and [Coverage] for [filename] using the given [options].
 Future<CodeLinesResult> computeCodeLines(
     List<String> options,
-    String filename,
-    {bool addAnnotations: true}) async {
+    String filename) async {
   SourceMapProcessor processor = new SourceMapProcessor(filename);
   SourceMaps sourceMaps =
       await processor.process(options, perElement: true, forMain: true);
 
-  const int WITH_SOURCE_INFO = 0;
-  const int WITHOUT_SOURCE_INFO = 1;
-  const int ADDITIONAL_SOURCE_INFO = 2;
-  const int UNUSED_SOURCE_INFO = 3;
+  CodeSources codeSources = new CodeSources(processor, sourceMaps);
 
   SourceMapInfo info = sourceMaps.mainSourceMapInfo;
 
+  int nextAnnotationId = 0;
   List<CodeLine> codeLines;
   Coverage coverage = new Coverage();
-  List<Annotation> annotations = <Annotation>[];
-
-  void addAnnotation(int id, int offset, String title) {
-    annotations.add(new Annotation(id, offset, title));
+  Map<int, List<CodeLineAnnotation>> codeLineAnnotationMap =
+      <int, List<CodeLineAnnotation>>{};
+
+  /// Create a [CodeLineAnnotation] for [codeOffset].
+  void addCodeLineAnnotation(
+      {AnnotationType annotationType,
+       int codeOffset,
+       List<SourceLocation> locations: const <SourceLocation>[],
+       String stepInfo}) {
+    if (annotationType == AnnotationType.WITHOUT_SOURCE_INFO ||
+        annotationType == AnnotationType.UNUSED_SOURCE_INFO) {
+      locations = [];
+    }
+    List<CodeLocation> codeLocations = locations
+        .map((l) => new CodeLocation(l.sourceUri, l.sourceName, l.offset))
+        .toList();
+    List<CodeSource> codeSourceList = locations
+        .map(codeSources.sourceLocationToCodeSource)
+        .where((c) => c != null)
+        .toList();
+    CodeLineAnnotation data = new CodeLineAnnotation(
+        annotationId: nextAnnotationId++,
+        annotationType: annotationType,
+        codeLocations: codeLocations,
+        codeSources: codeSourceList,
+        stepInfo: stepInfo);
+    codeLineAnnotationMap.putIfAbsent(
+        codeOffset, () => <CodeLineAnnotation>[]).add(data);
   }
 
   String code = info.code;
   TraceGraph graph = createTraceGraph(info, coverage);
-  if (addAnnotations) {
-    Set<js.Node> mappedNodes = new Set<js.Node>();
-
-    void addSourceLocations(
-        int kind, int offset, List<SourceLocation> locations, String prefix) {
-
-      addAnnotation(kind, offset,
-          '${prefix}${locations
-              .where((l) => l != null)
-              .map((l) => l.shortText)
-              .join('\n')}');
-    }
-
-    bool addSourceLocationsForNode(int kind, js.Node node, String prefix) {
-      Map<int, List<SourceLocation>> locations = info.nodeMap[node];
-      if (locations == null || locations.isEmpty) {
-        return false;
-      }
-      locations.forEach(
-          (int offset, List<SourceLocation> locations) {
-        addSourceLocations(kind, offset, locations,
-            '${prefix}\n${truncate(nodeToString(node), 80)}\n');
-      });
-      mappedNodes.add(node);
-      return true;
-    }
-
-
-    for (TraceStep step in graph.steps) {
-      String title = '${step.id}:${step.kind}:${step.offset}';
-      if (!addSourceLocationsForNode(WITH_SOURCE_INFO, step.node, title)) {
-        int offset;
-        if (options.contains(USE_NEW_SOURCE_INFO)) {
-          offset = step.offset.subexpressionOffset;
-        } else {
-          offset = info.jsCodePositions[step.node].startPosition;
-        }
-        if (offset != null) {
-          addAnnotation(WITHOUT_SOURCE_INFO, offset, title);
-        }
-      }
-    }
-    for (js.Node node in info.nodeMap.nodes) {
-      if (!mappedNodes.contains(node)) {
-        addSourceLocationsForNode(ADDITIONAL_SOURCE_INFO, node, '');
-      }
-    }
-    SourceLocationCollector collector = new SourceLocationCollector();
-    info.node.accept(collector);
-    collector.sourceLocations.forEach(
-        (js.Node node, List<SourceLocation> locations) {
-      if (!mappedNodes.contains(node)) {
-        int offset = info.jsCodePositions[node].startPosition;
-        addSourceLocations(UNUSED_SOURCE_INFO, offset, locations, '');
-      }
+
+  Set<js.Node> mappedNodes = new Set<js.Node>();
+
+  /// Add an annotation for [codeOffset] pointing to [locations].
+  void addSourceLocations(
+      {AnnotationType annotationType,
+       int codeOffset,
+       List<SourceLocation> locations,
+       String stepInfo}) {
+    locations = locations.where((l) => l != null).toList();
+    addCodeLineAnnotation(
+        annotationType: annotationType,
+        codeOffset: codeOffset,
+        stepInfo: stepInfo,
+        locations: locations);
+  }
+
+  /// Add annotations for all mappings created for [node].
+  bool addSourceLocationsForNode(
+      {AnnotationType annotationType,
+       js.Node node,
+       String stepInfo}) {
+    Map<int, List<SourceLocation>> locations = info.nodeMap[node];
+    if (locations == null || locations.isEmpty) {
+      return false;
+    }
+    locations.forEach((int offset, List<SourceLocation> locations) {
+      addSourceLocations(
+          annotationType: annotationType,
+          codeOffset: offset,
+          locations: locations,
+          stepInfo: stepInfo);
     });
-  }
-
+    mappedNodes.add(node);
+    return true;
+  }
+
+  // Add annotations based on trace steps.
+  for (TraceStep step in graph.steps) {
+    String stepInfo = '${step.id}:${step.kind}:${step.offset}';
+    bool added = addSourceLocationsForNode(
+        annotationType: AnnotationType.WITH_SOURCE_INFO,
+        node: step.node,
+        stepInfo: stepInfo);
+    if (!added) {
+      int offset;
+      if (options.contains(USE_NEW_SOURCE_INFO)) {
+        offset = step.offset.subexpressionOffset;
+      } else {
+        offset = info.jsCodePositions[step.node].startPosition;
+      }
+      if (offset != null) {
+        addCodeLineAnnotation(
+            annotationType: AnnotationType.WITHOUT_SOURCE_INFO,
+            codeOffset: offset,
+            stepInfo: stepInfo);
+      }
+    }
+  }
+
+  // Add additional annotations for mappings created for particular nodes.
+  for (js.Node node in info.nodeMap.nodes) {
+    if (!mappedNodes.contains(node)) {
+      addSourceLocationsForNode(
+          annotationType: AnnotationType.ADDITIONAL_SOURCE_INFO,
+          node: node);
+    }
+  }
+
+  // Add annotations for unused source information associated with nodes.
+  SourceLocationCollector collector = new SourceLocationCollector();
+  info.node.accept(collector);
+  collector.sourceLocations.forEach(
+      (js.Node node, List<SourceLocation> locations) {
+    if (!mappedNodes.contains(node)) {
+      int offset = info.jsCodePositions[node].startPosition;
+      addSourceLocations(
+        annotationType: AnnotationType.UNUSED_SOURCE_INFO,
+        codeOffset: offset,
+        locations: locations);
+    }
+  });
+
+  // Assign consecutive ids to source mappings.
+  int nextSourceMappedLocationIndex = 0;
+  List<Annotation> annotations = <Annotation>[];
+  for (int codeOffset in codeLineAnnotationMap.keys.toList()..sort()) {
+    bool hasSourceMappedLocation = false;
+    for (CodeLineAnnotation data in codeLineAnnotationMap[codeOffset]) {
+      if (data.annotationType.isSourceMapped) {
+        data.sourceMappingIndex = nextSourceMappedLocationIndex;
+        hasSourceMappedLocation = true;
+      }
+      annotations.add(new Annotation(
+          data.annotationType.index,
+          codeOffset,
+          'id=${data.annotationId}',
+          data: data));
+    }
+    if (hasSourceMappedLocation) {
+      nextSourceMappedLocationIndex++;
+    }
+  }
+
+  // Associate JavaScript offsets with [Element]s.
   StringSourceFile sourceFile = new StringSourceFile.fromName(filename, code);
   Map<int, Element> elementMap = <int, Element>{};
   sourceMaps.elementSourceMapInfos.forEach(
       (Element element, SourceMapInfo info) {
     CodePosition position = info.jsCodePositions[info.node];
     elementMap[sourceFile.getLine(position.startPosition)] = element;
   });
 
-  codeLines = convertAnnotatedCodeToCodeLines(
-      code,
-      annotations,
-      colorScheme: new CustomColorScheme(
-        single: (int id) {
-          if (id == WITH_SOURCE_INFO) {
-            return WITH_SOURCE_INFO_STYLE;
-          } else if (id == ADDITIONAL_SOURCE_INFO) {
-            return ADDITIONAL_SOURCE_INFO_STYLE;
-          } else if (id == UNUSED_SOURCE_INFO) {
-            return UNUSED_SOURCE_INFO_STYLE;
-          }
-          return WITHOUT_SOURCE_INFO_STYLE;
-        },
-        multi: (List ids) {
-          if (ids.contains(WITH_SOURCE_INFO)) {
-            return WITH_SOURCE_INFO_STYLE;
-          } else if (ids.contains(ADDITIONAL_SOURCE_INFO)) {
-            return ADDITIONAL_SOURCE_INFO_STYLE;
-          } else if (ids.contains(UNUSED_SOURCE_INFO)) {
-            return UNUSED_SOURCE_INFO_STYLE;
-          }
-          return WITHOUT_SOURCE_INFO_STYLE;
-        }
-      ));
-  return new CodeLinesResult(codeLines, coverage, elementMap,
-      sourceMaps.sourceFileManager);
+  codeLines = convertAnnotatedCodeToCodeLines(code, annotations);
+  return new CodeLinesResult(
+      codeLines, coverage, elementMap,
+      sourceMaps.sourceFileManager,
+      codeSources);
 }
 
 /// Visitor that computes a map from [js.Node]s to all attached source
 /// locations.
 class SourceLocationCollector extends js.BaseVisitor {
   Map<js.Node, List<SourceLocation>> sourceLocations =
       <js.Node, List<SourceLocation>>{};
 
   @override
   visitNode(js.Node node) {
@@ skipping 25 matching lines @@
     AstElement astElement = element.implementation;
     kind = CodeKind.MEMBER;
     uri = astElement.compilationUnit.script.resourceUri;
     name = computeElementNameForSourceMaps(astElement);
     if (astElement.hasNode) {
       begin = astElement.node.getBeginToken().charOffset;
       end = astElement.node.getEndToken().charEnd;
     }
   }
   return new CodeSource(kind, uri, name, begin, end);
-}
+}
+
+/// Create [LineData] that colors line numbers according to the [CodeSource]s
+/// origin if available.
+LineData getLineData(CodeSource lineAnnotation) {
+  if (lineAnnotation != null) {
+    return new LineData(
+        lineClass: ClassNames.line,
+        lineNumberClass:
+          '${ClassNames.lineNumber} '
+          '${ClassNames.colored(lineAnnotation.hashCode % 4)}');
+  }
+  return new LineData(
+      lineClass: ClassNames.line,
+      lineNumberClass: ClassNames.lineNumber);
+}
+
+AnnotationData getAnnotationData(Iterable<Annotation> annotations,
+                                 {bool forSpan}) {
+  for (Annotation annotation in annotations) {
+    CodeLineAnnotation data = annotation.data;
+    if (data.annotationType.isSourceMapped) {
+      if (forSpan) {
+        int index = data.sourceMappingIndex;
+        return new AnnotationData(
+            tag: 'span',
+            properties: {
+              'class':
+                '${ClassNames.sourceMapping} '
+                '${ClassNames.sourceMappingIndex(index % HUE_COUNT)}',
+              'title': 'index=$index',
+            });
+      } else {
+        return new AnnotationData(
+            tag: 'span',
+            properties: {
+              'title': annotation.title,
+              'class': '${ClassNames.marker} '
+                       '${data.annotationType.className}'});
+      }
+    }
+  }
+  if (forSpan) return null;
+  for (Annotation annotation in annotations) {
+    CodeLineAnnotation data = annotation.data;
+    if (data.annotationType == AnnotationType.UNUSED_SOURCE_INFO) {
+      return new AnnotationData(
+          tag: 'span',
+          properties: {
+            'title': annotation.title,
+            'class': '${ClassNames.marker} '
+                     '${data.annotationType.className}'});
+    }
+  }
+  for (Annotation annotation in annotations) {
+    CodeLineAnnotation data = annotation.data;
+    if (data.annotationType == AnnotationType.WITHOUT_SOURCE_INFO) {
+      return new AnnotationData(
+          tag: 'span',
+          properties: {
+            'title': annotation.title,
+            'class': '${ClassNames.marker} '
+                     '${data.annotationType.className}'});
+    }
+  }
+  return null;
+}