Revert "Switch FE to use the libraries.json format."

pkg/front_end/lib/src/base/processed_options.dart

 // Copyright (c) 2017, 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.
 
 import 'dart:async';
 
 import 'package:front_end/compilation_message.dart';
 import 'package:front_end/compiler_options.dart';
 import 'package:front_end/file_system.dart';
 import 'package:front_end/src/base/performace_logger.dart';
@@ skipping 10 matching lines @@
 import 'package:kernel/target/targets.dart';
 import 'package:kernel/target/vm_fasta.dart';
 import 'package:package_config/packages.dart' show Packages;
 import 'package:package_config/src/packages_impl.dart'
     show NonFilePackagesDirectoryPackages, MapPackages;
 import 'package:package_config/packages_file.dart' as package_config;
 import 'package:source_span/source_span.dart' show SourceSpan, SourceLocation;
 import 'package:front_end/src/fasta/command_line_reporting.dart'
     as command_line_reporting;
 
-import 'libraries_specification.dart';
-
 /// All options needed for the front end implementation.
 ///
 /// This includes: all of [CompilerOptions] in a form useful to the
 /// implementation, default values for options that were not provided,
 /// and information derived from how the compiler was invoked (like the
 /// entry-points given to the compiler and whether a modular or whole-program
 /// API was used).
 ///
 /// The intent is that the front end should immediately wrap any incoming
 /// [CompilerOptions] object in this class before doing further processing, and
@@ skipping 28 matching lines @@
   /// includes inferred types.
   List<Program> _inputSummariesPrograms;
 
   /// Other programs that are meant to be linked and compiled with the input
   /// sources.
   List<Program> _linkedDependencies;
 
   /// The location of the SDK, or `null` if the location hasn't been determined
   /// yet.
   Uri _sdkRoot;
-  Uri get sdkRoot {
-    _ensureSdkDefaults();
-    return _sdkRoot;
-  }
+  Uri get sdkRoot => _sdkRoot ??= _normalizeSdkRoot();
 
   Uri _sdkSummary;
-  Uri get sdkSummary {
-    _ensureSdkDefaults();
-    return _sdkSummary;
-  }
-
-  Uri _librariesSpecificationUri;
-  Uri get librariesSpecificationUri {
-    _ensureSdkDefaults();
-    return _librariesSpecificationUri;
-  }
+  Uri get sdkSummary => _sdkSummary ??= _computeSdkSummaryUri();
 
   Ticker ticker;
 
   bool get verbose => _raw.verbose;
 
   bool get verify => _raw.verify;
 
   bool get debugDump => _raw.debugDump;
 
   bool get setExitCodeOnProblem => _raw.setExitCodeOnProblem;
@@ skipping 174 matching lines @@
   Program loadProgram(List<int> bytes, CanonicalName nameRoot) {
     return loadProgramFromBytes(bytes, new Program(nameRoot: nameRoot));
   }
 
   /// Get the [UriTranslator] which resolves "package:" and "dart:" URIs.
   ///
   /// This is an asynchronous method since file system operations may be
   /// required to locate/read the packages file as well as SDK metadata.
   Future<UriTranslatorImpl> getUriTranslator() async {
     if (_uriTranslator == null) {
-      ticker.logMs("Started building UriTranslator");
-      var libraries = await _computeLibrarySpecification();
-      ticker.logMs("Read libraries file");
-      var packages = await _getPackages();
+      await _getPackages();
+      // TODO(scheglov) Load SDK libraries from whatever format we decide.
+      // TODO(scheglov) Remove the field "_raw.dartLibraries".
+      var libraries = _raw.dartLibraries ?? await _parseDartLibraries();
+      _uriTranslator = new UriTranslatorImpl(
+          libraries, const <String, List<Uri>>{}, _packages);
       ticker.logMs("Read packages file");
-      _uriTranslator = new UriTranslatorImpl(libraries, packages);
     }
     return _uriTranslator;
   }
 
-  Future<TargetLibrariesSpecification> _computeLibrarySpecification() async {
-    var name = target.name;
-    // TODO(sigmund): Eek! We should get to the point where there is no
-    // fasta-specific targets and the target names are meaningful.
-    if (name.endsWith('_fasta')) name = name.substring(0, name.length - 6);
-
-    if (librariesSpecificationUri == null ||
-        !await fileSystem.entityForUri(librariesSpecificationUri).exists()) {
-      if (compileSdk) {
-        reportWithoutLocation(
-            templateSdkSpecificationNotFound
-                .withArguments(librariesSpecificationUri),
-            Severity.error);
-      }
-      return new TargetLibrariesSpecification(name);
-    }
-
-    var json =
-        await fileSystem.entityForUri(librariesSpecificationUri).readAsString();
-    try {
-      var spec =
-          await LibrariesSpecification.parse(librariesSpecificationUri, json);
-      return spec.specificationFor(name);
-    } on LibrariesSpecificationException catch (e) {
-      reportWithoutLocation(
-          templateCannotReadSdkSpecification.withArguments('${e.error}'),
-          Severity.error);
-      return new TargetLibrariesSpecification(name);
-    }
+  Future<Map<String, Uri>> _parseDartLibraries() async {
+    Uri librariesJson = _raw.sdkRoot?.resolve("lib/libraries.json");
+    return await computeDartLibraries(fileSystem, librariesJson);
   }
 
   /// Get the package map which maps package names to URIs.
   ///
   /// This is an asynchronous getter since file system operations may be
   /// required to locate/read the packages file.
   Future<Packages> _getPackages() async {
     if (_packages != null) return _packages;
     if (_raw.packagesFileUri != null) {
       return _packages = await createPackagesFromFile(_raw.packagesFileUri);
@@ skipping 90 matching lines @@
       candidate = await checkInDir(parentDir);
       if (candidate != null) break;
       dir = parentDir;
       parentDir = dir.resolve('..');
     }
 
     if (candidate != null) return createPackagesFromFile(candidate);
     return Packages.noPackages;
   }
 
-  bool _computedSdkDefaults = false;
-
-  /// Ensure [_sdkRoot], [_sdkSummary] and [_librarySpecUri] are initialized.
-  ///
-  /// If they are not set explicitly, they are infered based on the default
-  /// behavior described in [CompilerOptions].
-  void _ensureSdkDefaults() {
-    if (_computedSdkDefaults) return;
-    _computedSdkDefaults = true;
-    var root = _raw.sdkRoot;
-    if (root != null) {
-      // Normalize to always end in '/'
-      if (!root.path.endsWith('/')) {
-        root = root.replace(path: root.path + '/');
-      }
-      _sdkRoot = root;
-    } else if (compileSdk) {
+  /// Get the location of the SDK.
+  Uri _normalizeSdkRoot() {
+    // If an SDK summary location was provided, the SDK itself should not be
+    // needed.
+    assert(_raw.sdkSummary == null);
+    if (_raw.sdkRoot == null) {
       // TODO(paulberry): implement the algorithm for finding the SDK
       // automagically.
-      unimplemented('infer the default sdk location', -1, null);
+      return unimplemented('infer the default sdk location', -1, null);
     }
+    var root = _raw.sdkRoot;
+    if (!root.path.endsWith('/')) {
+      root = root.replace(path: root.path + '/');
+    }
+    return root;
+  }
 
-    if (_raw.sdkSummary != null) {
-      _sdkSummary = _raw.sdkSummary;
-    } else if (!compileSdk) {
-      // Infer based on the sdkRoot, but only when `compileSdk` is false,
-      // otherwise the default intent was to compile the sdk from sources and
-      // not to load an sdk summary file.
-      _sdkSummary = root?.resolve('outline.dill');
-    }
+  /// Get or infer the location of the SDK summary.
+  Uri _computeSdkSummaryUri() {
+    if (_raw.sdkSummary != null) return _raw.sdkSummary;
 
-    if (_raw.librariesSpecificationUri != null) {
-      _librariesSpecificationUri = _raw.librariesSpecificationUri;
-    } else if (compileSdk) {
-      _librariesSpecificationUri = sdkRoot.resolve('lib/libraries.json');
-    }
+    // Infer based on the sdkRoot, but only when `compileSdk` is false,
+    // otherwise the default intent was to compile the sdk from sources and not
+    // to load an sdk summary file.
+    if (_raw.compileSdk) return null;
+    return sdkRoot.resolve('outline.dill');
   }
 
   /// Create a [FileSystem] specific to the current options.
   ///
   /// If `_raw.multiRoots` is not empty, the file-system will implement the
   /// semantics of multiple roots. If [chaseDependencies] is false, the
   /// resulting file system will be hermetic.
   FileSystem _createFileSystem() {
     var result = _raw.fileSystem;
     // Note: hermetic checks are done before translating multi-root URIs, so
@@ skipping 50 matching lines @@
     writeList('Multiroots', _raw.multiRoots);
 
     sb.writeln('Modular: ${_modularApi}');
     sb.writeln('Hermetic: ${!chaseDependencies}'
         ' (provided: ${!_raw.chaseDependencies})');
     sb.writeln('Packages uri: ${_raw.packagesFileUri}');
     sb.writeln('Packages: ${_packages}');
 
     sb.writeln('Compile SDK: ${compileSdk}');
     sb.writeln('SDK root: ${_sdkRoot} (provided: ${_raw.sdkRoot})');
-    sb.writeln('SDK specification: ${_librariesSpecificationUri} '
-        '(provided: ${_raw.librariesSpecificationUri})');
     sb.writeln('SDK summary: ${_sdkSummary} (provided: ${_raw.sdkSummary})');
 
     sb.writeln('Strong: ${strongMode}');
     sb.writeln('Target: ${_target?.name} (provided: ${_raw.target?.name})');
 
     sb.writeln('throwOnErrorsAreFatal: ${throwOnErrors}');
     sb.writeln('throwOnWarningsAreFatal: ${throwOnWarnings}');
     sb.writeln('throwOnNits: ${throwOnNits}');
     sb.writeln('exit on problem: ${setExitCodeOnProblem}');
     sb.writeln('Embed sources: ${embedSourceText}');
@@ skipping 44 matching lines @@
   String get dart2jsCode => _original.code.dart2jsCode;
 
   SourceSpan get span =>
       new SourceLocation(_original.charOffset, sourceUrl: _original.uri)
           .pointSpan();
 
   _CompilationMessage(this._original, this.severity);
 
   String toString() => message;
 }