Add hacks into build_sdk_summaries to workaround bugs in build tools.

pkg/analyzer/tool/summary/build_sdk_summaries.dart

 import 'dart:io';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/java_io.dart';
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/sdk_io.dart';
 import 'package:analyzer/src/generated/source.dart';
-import 'package:analyzer/src/summary/format.dart';
+import 'package:analyzer/src/summary/flat_buffers.dart' as fb;
 import 'package:analyzer/src/summary/index_unit.dart';
 import 'package:analyzer/src/summary/summarize_elements.dart';
 import 'package:path/path.dart';
 
 main(List<String> args) {
-  if (args.length < 1 || args.length > 2) {
+  if (args.length < 1) {
     _printUsage();
     exitCode = 1;
     return;
   }
-  //
-  // Prepare output file path.
-  //
-  String outputDirectoryPath = args[0];
-  if (!FileSystemEntity.isDirectorySync(outputDirectoryPath)) {
-    print("'$outputDirectoryPath' is not a directory.");
+  String command = args[0];
+  if (command == 'multiple-outputs') {

[Paul Berry, 2016/03/09 18:23:21]

Add `&& args.length >= 2 && args.length <= 3`.  Otherwise passing too few args
could cause a crash, and passing too many arguments will cause the extra
arguments to be ignored.

+    //
+    // Prepare the output path.
+    //
+    String outputDirectoryPath = args[1];
+    if (!FileSystemEntity.isDirectorySync(outputDirectoryPath)) {
+      print("'$outputDirectoryPath' is not a directory.");
+      _printUsage();
+      exitCode = 1;
+      return;
+    }
+    //
+    // Prepare results.
+    //
+    String sdkPath = args.length > 2 ? args[2] : null;
+    _Output output = _buildMultipleOutputs(sdkPath);
+    if (output == null) {
+      exitCode = 1;
+      return;
+    }
+    //
+    // Write results.
+    //
+    output.spec.writeMultiple(outputDirectoryPath, 'spec');
+    output.strong.writeMultiple(outputDirectoryPath, 'strong');
+  } else if (command == 'single-output') {

[Paul Berry, 2016/03/09 18:23:21]

Same comment here.

+    String outputPath = args[1];
+    String sdkPath = args.length > 2 ? args[2] : null;
+    //
+    // Prepare results.
+    //
+    _Output output = _buildMultipleOutputs(sdkPath);
+    if (output == null) {
+      exitCode = 1;
+      return;
+    }
+    //
+    // Write results.
+    //
+    fb.Builder builder = new fb.Builder();
+    fb.Offset specSumOffset = builder.writeListUint8(output.spec.sum);
+    fb.Offset specIndexOffset = builder.writeListUint8(output.spec.index);
+    fb.Offset strongSumOffset = builder.writeListUint8(output.strong.sum);
+    fb.Offset strongIndexOffset = builder.writeListUint8(output.strong.index);
+    builder.startTable();
+    builder.addOffset(_FIELD_SPEC_SUM, specSumOffset);
+    builder.addOffset(_FIELD_SPEC_INDEX, specIndexOffset);
+    builder.addOffset(_FIELD_STRONG_SUM, strongSumOffset);
+    builder.addOffset(_FIELD_STRONG_INDEX, strongIndexOffset);
+    fb.Offset offset = builder.endTable();
+    new File(outputPath)
+        .writeAsBytesSync(builder.finish(offset), mode: FileMode.WRITE_ONLY);
+  } else if (command == 'extract-spec-sum' && args.length == 3) {
+    String inputPath = args[1];
+    String outputPath = args[2];
+    _extractSingleOutput(inputPath, _FIELD_SPEC_SUM, outputPath);
+  } else if (command == 'extract-spec-index' && args.length == 3) {
+    String inputPath = args[1];
+    String outputPath = args[2];
+    _extractSingleOutput(inputPath, _FIELD_SPEC_INDEX, outputPath);
+  } else if (command == 'extract-strong-sum' && args.length == 3) {
+    String inputPath = args[1];
+    String outputPath = args[2];
+    _extractSingleOutput(inputPath, _FIELD_STRONG_SUM, outputPath);
+  } else if (command == 'extract-strong-index' && args.length == 3) {
+    String inputPath = args[1];
+    String outputPath = args[2];
+    _extractSingleOutput(inputPath, _FIELD_STRONG_INDEX, outputPath);
+  } else {
     _printUsage();
     exitCode = 1;
     return;
   }
-  //
-  // Prepare SDK path.
-  //
-  String sdkPath;
-  if (args.length == 2) {
-    sdkPath = args[1];
-    if (!FileSystemEntity.isDirectorySync('$sdkPath/lib')) {
-      print("'$sdkPath/lib' does not exist.");
-      _printUsage();
-      exitCode = 1;
-      return;
-    }
-  } else {
-    sdkPath = DirectoryBasedDartSdk.defaultSdkDirectory.getAbsolutePath();
-  }
-  //
-  // Build spec and strong summaries.
-  //
-  new _Builder(sdkPath, outputDirectoryPath, false).build();
-  new _Builder(sdkPath, outputDirectoryPath, true).build();
 }
 
 /**
  * The name of the SDK summaries builder application.
  */
 const BINARY_NAME = "build_sdk_summaries";
 
+const int _FIELD_SPEC_INDEX = 1;
+const int _FIELD_SPEC_SUM = 0;
+const int _FIELD_STRONG_INDEX = 3;
+const int _FIELD_STRONG_SUM = 2;
+
+_Output _buildMultipleOutputs(String sdkPath) {
+  //
+  // Validate the SDK path.
+  //
+  if (sdkPath != null) {
+    if (!FileSystemEntity.isDirectorySync('$sdkPath/lib')) {
+      print("'$sdkPath/lib' does not exist.");
+      _printUsage();
+      return null;
+    }
+  } else {
+    sdkPath = DirectoryBasedDartSdk.defaultSdkDirectory.getAbsolutePath();
+  }
+  //
+  // Build spec and strong outputs.
+  //
+  _BuilderOutput spec = new _Builder(sdkPath, false).build();
+  _BuilderOutput strong = new _Builder(sdkPath, true).build();
+  return new _Output(spec, strong);
+}
+
+/**
+ * Open the flat buffer in [inputPath] and extract the byte array in the [field]
+ * into the [outputPath] file.
+ */
+void _extractSingleOutput(String inputPath, int field, String outputPath) {
+  List<int> bytes = new File(inputPath).readAsBytesSync();
+  fb.BufferPointer bp = new fb.BufferPointer.fromBytes(bytes);
+  fb.BufferPointer table = bp.derefObject();
+  List<int> fieldBytes =
+      const fb.ListReader(const fb.Uint8Reader()).vTableGet(table, field);
+  new File(outputPath).writeAsBytesSync(fieldBytes, mode: FileMode.WRITE_ONLY);
+}
+
 /**
  * Print information about how to use the SDK summaries builder.
  */
 void _printUsage() {
-  print('Usage: $BINARY_NAME output_directory_path [sdk_path]');
-  print('Build files spec.sum and strong.sum in the output directory.');
+//  print('Usage: $BINARY_NAME command output_directory_path [sdk_path]');
+  print('Usage: $BINARY_NAME command arguments');
+  print('Where command can be one of the following:');
+  print('  multiple-outputs output_directory_path [sdk_path]');
+  print('    Generate separate summary and index files.');
+  print('  single-output output_file_path [sdk_path]');
+  print('    Generate a single file with summary and index.');
+  print('  extract-spec-sum input_file output_file');
+  print('    Extract the spec-mode summary file.');
+  print('  extract-strong-sum input_file output_file');
+  print('    Extract the strong-mode summary file.');
+  print('  extract-spec-index input_file output_file');
+  print('    Extract the spec-mode index file.');
+  print('  extract-strong-index input_file output_file');
+  print('    Extract the strong-mode index file.');
 }
 
 class _Builder {
   final String sdkPath;
-  final String outputDirectoryPath;
   final bool strongMode;
 
   AnalysisContext context;
   final Set<Source> processedSources = new Set<Source>();
 
   final PackageBundleAssembler bundleAssembler = new PackageBundleAssembler();
   final PackageIndexAssembler indexAssembler = new PackageIndexAssembler();
 
-  _Builder(this.sdkPath, this.outputDirectoryPath, this.strongMode);
+  _Builder(this.sdkPath, this.strongMode);
 
   /**
    * Build a strong or spec mode summary for the Dart SDK at [sdkPath].
    */
-  void build() {
+  _BuilderOutput build() {
     String modeName = strongMode ? 'strong' : 'spec';
     print('Generating $modeName mode summary and index.');
     Stopwatch sw = new Stopwatch()..start();
     //
     // Prepare SDK.
     //
     DirectoryBasedDartSdk sdk =
         new DirectoryBasedDartSdk(new JavaFile(sdkPath));
     sdk.useSummary = false;
     context = sdk.context;
     context.analysisOptions = new AnalysisOptionsImpl()
       ..strongMode = strongMode;
     //
     // Prepare 'dart:' URIs to serialize.
     //
     Set<String> uriSet =
         sdk.sdkLibraries.map((SdkLibrary library) => library.shortName).toSet();
     uriSet.add('dart:html/nativewrappers.dart');
     uriSet.add('dart:html_common/html_common_dart2js.dart');
     //
     // Serialize each SDK library.
     //
     for (String uri in uriSet) {
       Source libSource = sdk.mapDartUri(uri);
       _serializeLibrary(libSource);
     }
     //
-    // Write the whole SDK bundle.
+    // Assemble the output.
     //
-    {
-      PackageBundleBuilder bundle = bundleAssembler.assemble();
-      String outputPath = join(outputDirectoryPath, '$modeName.sum');
-      File file = new File(outputPath);
-      file.writeAsBytesSync(bundle.toBuffer(), mode: FileMode.WRITE_ONLY);
-    }
-    //
-    // Write the whole SDK index.
-    //
-    {
-      PackageIndexBuilder index = indexAssembler.assemble();
-      String outputPath = join(outputDirectoryPath, '$modeName.index');
-      File file = new File(outputPath);
-      file.writeAsBytesSync(index.toBuffer(), mode: FileMode.WRITE_ONLY);
-    }
-    //
-    // Done.
-    //
+    List<int> sumBytes = bundleAssembler.assemble().toBuffer();
+    List<int> indexBytes = indexAssembler.assemble().toBuffer();
     print('\tDone in ${sw.elapsedMilliseconds} ms.');
+    return new _BuilderOutput(sumBytes, indexBytes);
   }
 
   /**
    * Serialize the library with the given [source] and all its direct or
    * indirect imports and exports.
    */
   void _serializeLibrary(Source source) {
     if (!processedSources.add(source)) {
       return;
     }
     LibraryElement element = context.computeLibraryElement(source);
     bundleAssembler.serializeLibraryElement(element);
     element.importedLibraries.forEach((e) => _serializeLibrary(e.source));
     element.exportedLibraries.forEach((e) => _serializeLibrary(e.source));
     // Index every unit of the library.
     for (CompilationUnitElement unitElement in element.units) {
       Source unitSource = unitElement.source;
       CompilationUnit unit =
           context.resolveCompilationUnit2(unitSource, source);
       indexAssembler.index(unit);
     }
   }
 }
+
+class _BuilderOutput {
+  final List<int> sum;
+  final List<int> index;
+
+  _BuilderOutput(this.sum, this.index);
+
+  void writeMultiple(String outputDirectoryPath, String modeName) {
+    // Write summary.
+    {
+      String outputPath = join(outputDirectoryPath, '$modeName.sum');
+      File file = new File(outputPath);
+      file.writeAsBytesSync(sum, mode: FileMode.WRITE_ONLY);
+    }
+    // Write index.
+    {
+      String outputPath = join(outputDirectoryPath, '$modeName.index');
+      File file = new File(outputPath);
+      file.writeAsBytesSync(index, mode: FileMode.WRITE_ONLY);
+    }
+  }
+}
+
+class _Output {
+  final _BuilderOutput spec;
+  final _BuilderOutput strong;
+
+  _Output(this.spec, this.strong);
+}