Revert "Tweak public APIs and use them in patch_sdk, dart2js, and kernel-service."

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/front_end.dart';
-import 'package:front_end/src/base/processed_options.dart';
-import 'package:front_end/src/kernel_generator_impl.dart';
-import 'package:front_end/src/fasta/util/relativize.dart' show relativizeUri;
+import 'package:front_end/src/fasta/fasta.dart' as fasta
+    show compile, compilePlatform, writeDepsFile;
 
-import 'package:front_end/src/fasta/fasta.dart' as fasta show getDependencies;
-import 'package:front_end/src/fasta/kernel/utils.dart' show writeProgramToFile;
-
-import 'package:kernel/target/targets.dart';
-import 'package:kernel/target/vm_fasta.dart';
-import 'package:kernel/target/flutter_fasta.dart';
-import 'package:compiler/src/kernel/dart2js_target.dart' show Dart2jsTarget;
+import 'package:compiler/src/kernel/fasta_support.dart' as dart2js
+    show compilePlatform;
 
 /// Set of input files that were read by this script to generate patched SDK.
 /// We will dump it out into the depfile for ninja to use.
 ///
 /// For more information see GN and Ninja references:
 ///    https://chromium.googlesource.com/chromium/src/+/56807c6cb383140af0c03da8f6731d77785d7160/tools/gn/docs/reference.md#depfile_string_File-name-for-input-dependencies-for-actions
 ///    https://ninja-build.org/manual.html#_depfile
 ///
 final deps = new Set<Uri>();
 
@@ skipping 78 matching lines @@
   _copyExtraLibraries(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}));
 
-  var flags = new TargetFlags();
-  var target = forVm
-      ? new VmFastaTarget(flags)
-      : (forFlutter ? new FlutterFastaTarget(flags) : new Dart2jsTarget(flags));
-  var platformDeps =
-      await compilePlatform(outDirUri, target, packages, platform, outline);
-  deps.addAll(platformDeps);
+  if (forVm || forFlutter) {
+    await fasta.compilePlatform(outDirUri, platform,
+        packages: packages,
+        outlineOutput: outline,
+        backendTarget: forVm ? 'vm_fasta' : 'flutter_fasta');
+  } else {
+    await dart2js.compilePlatform(outDirUri, platform,
+        packages: packages, outlineOutput: outline);
+  }
 
   if (forVm) {
-    // TODO(sigmund): add support for the flutter vmservice_sky as well.
+    var base = path.fromUri(Platform.script);
+    Uri repositoryDir =
+        new Uri.directory(path.dirname(path.dirname(path.absolute(base))));
     var vmserviceName = 'vmservice_io';
-    var base = path.fromUri(Platform.script);
-    Uri dartDir =
-        new Uri.directory(path.dirname(path.dirname(path.absolute(base))));
-    var program = await kernelForProgram(
-        Uri.parse('dart:$vmserviceName'),
-        new CompilerOptions()
-          ..sdkSummary = outline
-          ..dartLibraries = <String, Uri>{
-            '_vmservice': outDirUri.resolve('lib/vmservice/vmservice.dart'),
-            'vmservice_io':
-                dartDir.resolve('runtime/bin/vmservice/vmservice_io.dart'),
-          }
-          ..packagesFileUri = packages);
+    Uri vmserviceSdk = repositoryDir.resolve('runtime/bin/vmservice_sdk/');
     Uri vmserviceUri = outDirUri.resolve('$vmserviceName.dill');
-    await writeProgramToFile(program, vmserviceUri);
+    // TODO(sigmundch): Specify libraries.json directly instead of "--sdk"
+    // after #29882 is fixed.
+    await fasta.compile([
+      "--sdk=$vmserviceSdk",
+      "--platform=$outline",
+      "--target=vm_fasta",
+      "--packages=$packages",
+      "dart:$vmserviceName",
+      "-o",
+      "$vmserviceUri",
+    ]);
   }
 
   Uri platformFinalLocation = outDirUri.resolve('platform.dill');
 
   // We generate a dependency file for GN to properly regenerate the patched sdk
   // folder, outline.dill and platform.dill files when necessary: either when
   // the sdk sources change or when this script is updated. In particular:
   //
   //  - sdk changes: we track the actual sources we are compiling. If we are
   //    building the dart2js sdk, this includes the dart2js-specific patch
   //    files.
   //
   //    These files are tracked by [deps] and passed below to [writeDepsFile] in
   //    the extraDependencies argument.
   //
   //  - script updates: we track this script file and any code it imports (even
   //    sdk libraries). Note that this script runs on the standalone VM, so any
   //    sdk library used by this script indirectly depends on a VM-specific
   //    patch file.
   //
-  //    These set of files is discovered by `getDependencies` below, and the
+  //    These set of files is discovered by `writeDepsFile` below, and the
   //    [platformForDeps] is always the VM-specific `platform.dill` file.
+  //
+  //    TODO(sigmund): we should change this:
+  //      - we should rewrite writeDepsFile: fasta could provide an API to crawl
+  //        the dependencies, but anything that is GN specific, should be on
+  //        this file instead.
+  //
+  //      - We don't need to include sdk dependencies of the script because
+  //        those are already included indirectly (either in [deps] when
+  //        building the sdk for the VM, or via the .GN dependencies in the
+  //        build files for dart2js and flutter).
   var platformForDeps = platform;
   var sdkDir = outDirUri;
   if (forDart2js || forFlutter) {
     // Note: this would fail if `../patched_sdk/platform.dill` doesn't exist. We
     // added an explicit dependency in the .GN rules so patched_dart2js_sdk (and
     // patched_flutter_sdk) depend on patched_sdk to ensure that it exists.
     platformForDeps = outDirUri.resolve('../patched_sdk/platform.dill');
     sdkDir = outDirUri.resolve('../patched_sdk/');
   }
-  deps.addAll(await fasta.getDependencies(Platform.script,
-      sdk: sdkDir, packages: packages, platform: platformForDeps));
-  await writeDepsFile(Uri.base.resolveUri(new Uri.file("$outDir.d")),
-      platformFinalLocation, deps);
+  await fasta.writeDepsFile(Platform.script,
+      Uri.base.resolveUri(new Uri.file("$outDir.d")), platformFinalLocation,
+      sdk: sdkDir,
+      packages: packages,
+      platform: platformForDeps,
+      extraDependencies: deps);
+
   await new File.fromUri(platform).rename(platformFinalLocation.toFilePath());
 }
 
-/// Generates an outline.dill and platform.dill file containing the result of
-/// compiling a platform's SDK.
-///
-/// Returns a list of dependencies read by the compiler. This list can be used
-/// to create GN dependency files.
-Future<List<Uri>> compilePlatform(Uri patchedSdk, Target target, Uri packages,
-    Uri fullOutput, Uri outlineOutput) async {
-  var options = new CompilerOptions()
-    ..strongMode = false
-    ..compileSdk = true
-    ..sdkRoot = patchedSdk
-    ..packagesFileUri = packages
-    ..chaseDependencies = true
-    ..target = target;
-
-  var result = await generateKernel(
-      new ProcessedOptions(
-          options,
-          // TODO(sigmund): pass all sdk libraries needed here, and make this
-          // hermetic.
-          false,
-          [Uri.parse('dart:core')]),
-      buildSummary: true,
-      buildProgram: true);
-  new File.fromUri(outlineOutput).writeAsBytesSync(result.summary);
-  await writeProgramToFile(result.program, fullOutput);
-  return result.deps;
-}
-
-Future writeDepsFile(
-    Uri output, Uri depsFile, Iterable<Uri> allDependencies) async {
-  if (allDependencies.isEmpty) return;
-  String toRelativeFilePath(Uri uri) {
-    // Ninja expects to find file names relative to the current working
-    // directory. We've tried making them relative to the deps file, but that
-    // doesn't work for downstream projects. Making them absolute also
-    // doesn't work.
-    //
-    // We can test if it works by running ninja twice, for example:
-    //
-    //     ninja -C xcodebuild/ReleaseX64 runtime_kernel -d explain
-    //     ninja -C xcodebuild/ReleaseX64 runtime_kernel -d explain
-    //
-    // The second time, ninja should say:
-    //
-    //     ninja: Entering directory `xcodebuild/ReleaseX64'
-    //     ninja: no work to do.
-    //
-    // It's broken if it says something like this:
-    //
-    //     ninja explain: expected depfile 'patched_sdk.d' to mention
-    //     'patched_sdk/platform.dill', got
-    //     '/.../xcodebuild/ReleaseX64/patched_sdk/platform.dill'
-    return Uri.parse(relativizeUri(uri, base: Uri.base)).toFilePath();
-  }
-
-  StringBuffer sb = new StringBuffer();
-  sb.write(toRelativeFilePath(output));
-  sb.write(":");
-  for (Uri uri in allDependencies) {
-    sb.write(" ");
-    sb.write(toRelativeFilePath(uri));
-  }
-  sb.writeln();
-  await new File.fromUri(depsFile).writeAsString("$sb");
-}
-
 /// 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) {
   if (!forVm && !forFlutter) return libContents;
   var extraLibraries = new StringBuffer();
   extraLibraries.write('''
   "_builtin": const LibraryInfo(
       "_builtin/_builtin.dart",
       categories: "Client,Server",
@@ skipping 463 matching lines @@
     if (diff != 0) return diff;
     return end - other.end;
   }
 }
 
 List<SdkLibrary> _getSdkLibraries(String contents) {
   var libraryBuilder = new SdkLibrariesReader_LibraryBuilder(forDart2js);
   parseCompilationUnit(contents).accept(libraryBuilder);
   return libraryBuilder.librariesMap.sdkLibraries;
 }