Read SDK and patches from a JSON file.

tools/patch_sdk.dart

 #!/usr/bin/env 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.
 
 /// Command line tool to merge the SDK libraries and our patch files.
 /// This is currently designed as an offline tool, but we could automate it.
 
 import 'dart:io';
 import 'dart:isolate' show RawReceivePort;
 import 'dart:async';
 import 'dart:math' as math;
+import 'dart:convert' show JSON;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:path/path.dart' as path;
 
 import 'package:front_end/src/fasta/fasta.dart' as fasta
     show compilePlatform, writeDepsFile;
 
 import 'package:compiler/src/kernel/fasta_support.dart' as dart2js
     show compilePlatform;
@@ skipping 65 matching lines @@
   var outDirUri = Uri.base.resolveUri(new Uri.directory(outDir));
   var sdkOut = path.join(outDir, 'lib');
   var packagesFile = argv[4];
 
   // Parse libraries.dart
   var libContents = readInputFile(path.join(
       sdkLibIn, '_internal', 'sdk_library_metadata', 'lib', 'libraries.dart'));
   if (forVm) libContents = _updateLibraryMetadata(sdkOut, libContents);
   var sdkLibraries = _getSdkLibraries(libContents);
 
+  Map<String, String> locations = <String, String>{};
+
   // Enumerate core libraries and apply patches
   for (SdkLibrary library in sdkLibraries) {
     if (forDart2js && library.isVmLibrary) continue;
     if (forVm && library.isDart2JsLibrary) continue;
-    _applyPatch(library, sdkLibIn, patchIn, sdkOut);
+    _applyPatch(library, sdkLibIn, patchIn, sdkOut, locations);
   }
 
-  if (forVm) _copyExtraVmLibraries(sdkOut);
+  if (forVm) _copyExtraVmLibraries(sdkOut, locations);
 
   Uri platform = outDirUri.resolve('platform.dill.tmp');
   Uri outline = outDirUri.resolve('outline.dill');
+  Uri librariesJson = outDirUri.resolve("lib/libraries.json");
   Uri packages = Uri.base.resolveUri(new Uri.file(packagesFile));
+
+  await _writeSync(
+      librariesJson.toFilePath(), JSON.encode({"libraries": locations}));
+
   if (forVm) {
     await fasta.compilePlatform(outDirUri, platform,
         packages: packages, outlineOutput: outline);
   } else {
     await dart2js.compilePlatform(outDirUri, platform,
         packages: packages, outlineOutput: outline);
   }
 
   Uri platformFinalLocation = outDirUri.resolve('platform.dill');
 
   // To properly regenerate the patched_sdk, patched_dart2js_sdk, and
   // platform.dill only when necessary, we track dependencies as follows:
   //  - inputs like the sdk libraries and patch files are covered by the
   //    extraDependencies argument.
   //  - this script and its script dependencies are handled by writeDepsFile
   //    here.
   //  - the internal platform libraries that may affect how this script
   //    runs in the VM are discovered by providing the `platform` argument
   //    below. Regardless of patched_sdk or patched_dart2js_sdk we provide below
   //    the .dill file of patched_sdk (since the script runs in the VM and not
   //    in dart2js). At the BUILD.gn level we have a dependency from
   //    patched_dart2js_sdk to patched_sdk to ensure that file already exists.
   await fasta.writeDepsFile(Platform.script,
       Uri.base.resolveUri(new Uri.file("$outDir.d")), platformFinalLocation,
+      sdk: outDirUri,
       packages: packages,
       platform:
           forVm ? platform : outDirUri.resolve('../patched_sdk/platform.dill'),
-      extraDependencies: deps,
-      verbose: false);
+      extraDependencies: deps);
 
   await new File.fromUri(platform).rename(platformFinalLocation.toFilePath());
 }
 
 /// Updates the contents of
 /// sdk/lib/_internal/sdk_library_metadata/lib/libraries.dart to include
 /// declarations for vm internal libraries.
 String _updateLibraryMetadata(String sdkOut, String libContents) {
   // Copy and patch libraries.dart and version
   libContents = libContents.replaceAll(
@@ skipping 27 matching lines @@
 ''');
   _writeSync(
       path.join(
           sdkOut, '_internal', 'sdk_library_metadata', 'lib', 'libraries.dart'),
       libContents);
   return libContents;
 }
 
 /// Copy internal libraries that are developed under 'runtime/bin/' to the
 /// patched_sdk folder.
-_copyExtraVmLibraries(String sdkOut) {
+_copyExtraVmLibraries(String sdkOut, Map<String, String> locations) {
   var base = path.fromUri(Platform.script);
   var dartDir = path.dirname(path.dirname(path.absolute(base)));
 
   for (var tuple in [
     ['_builtin', 'builtin.dart']
   ]) {
     var vmLibrary = tuple[0];
     var dartFile = tuple[1];
 
     // The "dart:_builtin" library is only available for the DartVM.
     var builtinLibraryIn = path.join(dartDir, 'runtime', 'bin', dartFile);
     var builtinLibraryOut = path.join(sdkOut, vmLibrary, '${vmLibrary}.dart');
     _writeSync(builtinLibraryOut, readInputFile(builtinLibraryIn));
+    locations[vmLibrary] = path.join(vmLibrary, '${vmLibrary}.dart');
   }
 
   for (var file in ['loader.dart', 'server.dart', 'vmservice_io.dart']) {
     var libraryIn = path.join(dartDir, 'runtime', 'bin', 'vmservice', file);
     var libraryOut = path.join(sdkOut, 'vmservice_io', file);
     _writeSync(libraryOut, readInputFile(libraryIn));
   }
+  locations["vmservice_io"] = "vmservice_io/vmservice_io.dart";
 }
 
-_applyPatch(
-    SdkLibrary library, String sdkLibIn, String patchIn, String sdkOut) {
+_applyPatch(SdkLibrary library, String sdkLibIn, String patchIn, String sdkOut,
+    Map<String, String> locations) {
   var libraryOut = path.join(sdkLibIn, library.path);
   var libraryIn = libraryOut;
 
   var libraryFile = getInputFile(libraryIn, canBeMissing: true);
   if (libraryFile != null) {
+    locations[Uri.parse(library.shortName).path] =
+        path.relative(libraryOut, from: sdkLibIn);
     var outPaths = <String>[libraryOut];
     var libraryContents = libraryFile.readAsStringSync();
 
     int inputModifyTime = libraryFile.lastModifiedSync().millisecondsSinceEpoch;
     var partFiles = <File>[];
     for (var part in parseDirectives(libraryContents).directives) {
       if (part is PartDirective) {
         var partPath = part.uri.stringValue;
         outPaths.add(path.join(path.dirname(libraryOut), partPath));
 
@@ skipping 384 matching lines @@
     if (diff != 0) return diff;
     return end - other.end;
   }
 }
 
 List<SdkLibrary> _getSdkLibraries(String contents) {
   var libraryBuilder = new SdkLibrariesReader_LibraryBuilder(true);
   parseCompilationUnit(contents).accept(libraryBuilder);
   return libraryBuilder.librariesMap.sdkLibraries;
 }