Revert "[cfe] Encapsulate Dill/SourceLoader.builders" and "[cfe] Move…

… createLibraryBuilder methods to loaders"

This reverts commits 2bbb5dc and 0e7d0f5.

Change-Id: I140ae6eab70102d39b1bec665bedd3a3dbfb02bd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/217300
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Johnni Winther <johnniwinther@google.com>

pkg/dev_compiler/lib/src/kernel/expression_compiler.dart

@@ -416,7 +416,7 @@ class ExpressionCompiler {
 
   Future<Library> _getLibrary(Uri libraryUri) async {
     return await _compiler.context.runInContext((_) async {
-      var builder = _compiler.userCode.loader.lookupLibraryBuilder(libraryUri);
+      var builder = _compiler.userCode.loader.builders[libraryUri];
       if (builder != null) {
         var library =
             _compiler.userCode.loader.read(libraryUri, -1, accessor: builder);

pkg/front_end/lib/src/fasta/dill/dill_library_builder.dart

@@ -396,7 +396,7 @@ class DillLibraryBuilder extends LibraryBuilderImpl {
         } else {
           unhandled("${node.runtimeType}", "finalizeExports", -1, fileUri);
         }
-        LibraryBuilder? library = loader.lookupLibraryBuilder(libraryUri);
+        LibraryBuilder? library = loader.builders[libraryUri];
         if (library == null) {
           internalProblem(
               templateUnspecified

pkg/front_end/lib/src/fasta/dill/dill_loader.dart

@@ -47,10 +47,8 @@ import 'dart:collection' show Queue;
 class DillLoader extends Loader {
   SourceLoader? currentSourceLoader;
 
-  final Map<Uri, DillLibraryBuilder> _knownLibraryBuilders =
-      <Uri, DillLibraryBuilder>{};
-
-  final Map<Uri, DillLibraryBuilder> _builders = <Uri, DillLibraryBuilder>{};
+  @override
+  final Map<Uri, DillLibraryBuilder> builders = <Uri, DillLibraryBuilder>{};
 
   final Queue<DillLibraryBuilder> _unparsedLibraries =
       new Queue<DillLibraryBuilder>();
@@ -89,17 +87,11 @@ class DillLoader extends Loader {
   @override
   LibraryBuilder get coreLibrary => _coreLibrary!;
 
-  Ticker get ticker => target.ticker;
-
-  void registerKnownLibrary(Library library) {
-    _knownLibraryBuilders[library.importUri] =
-        new DillLibraryBuilder(library, this);
+  void set coreLibrary(LibraryBuilder value) {
+    _coreLibrary = value;
   }
 
-  // TODO(johnniwinther): This is never called!?!
-  void releaseAncillaryResources() {
-    _knownLibraryBuilders.clear();
-  }
+  Ticker get ticker => target.ticker;
 
   /// Look up a library builder by the [uri], or if such doesn't exist, create
   /// one. The canonical URI of the library is [uri], and its actual location is
@@ -113,35 +105,32 @@ class DillLoader extends Loader {
   /// directive. If [accessor] isn't allowed to access [uri], it's a
   /// compile-time error.
   DillLibraryBuilder read(Uri uri, int charOffset, {LibraryBuilder? accessor}) {
-    DillLibraryBuilder? libraryBuilder = _builders[uri];
-    if (libraryBuilder == null) {
-      libraryBuilder = _knownLibraryBuilders.remove(uri);
-      // ignore: unnecessary_null_comparison
-      assert(libraryBuilder != null, "No library found for $uri.");
-      _builders[uri] = libraryBuilder!;
-      assert(libraryBuilder.loader == this);
+    DillLibraryBuilder builder = builders.putIfAbsent(uri, () {
+      DillLibraryBuilder library = target.createLibraryBuilder(uri);
+      assert(library.loader == this);
       if (uri.scheme == "dart") {
         if (uri.path == "core") {
-          _coreLibrary = libraryBuilder;
+          _coreLibrary = library;
         }
       }
       {
         // Add any additional logic after this block. Setting the
         // firstSourceUri and first library should be done as early as
         // possible.
         firstSourceUri ??= uri;
-        first ??= libraryBuilder;
+        first ??= library;
       }
-      if (_coreLibrary == libraryBuilder) {
+      if (_coreLibrary == library) {
         target.loadExtraRequiredLibraries(this);
       }
       if (target.backendTarget.mayDefineRestrictedType(uri)) {
-        libraryBuilder.mayImplementRestrictedTypes = true;
+        library.mayImplementRestrictedTypes = true;
       }
-      _unparsedLibraries.addLast(libraryBuilder);
-    }
+      _unparsedLibraries.addLast(library);
+      return library;
+    });
     if (accessor != null) {
-      libraryBuilder.recordAccess(charOffset, noLength, accessor.fileUri);
+      builder.recordAccess(charOffset, noLength, accessor.fileUri);
       if (!accessor.isPatch &&
           !accessor.isPart &&
           !target.backendTarget
@@ -150,7 +139,7 @@ class DillLoader extends Loader {
             noLength, accessor.fileUri);
       }
     }
-    return libraryBuilder;
+    return builder;
   }
 
   void _ensureCoreLibrary() {
@@ -176,7 +165,7 @@ class DillLoader extends Loader {
   void _logSummary(Template<SummaryTemplate> template) {
     ticker.log((Duration elapsed, Duration sinceStart) {
       int libraryCount = 0;
-      for (DillLibraryBuilder library in libraryBuilders) {
+      for (DillLibraryBuilder library in builders.values) {
         assert(library.loader == this);
         libraryCount++;
       }
@@ -275,7 +264,7 @@ severity: $severity
       Uri uri = library.importUri;
       if (filter == null || filter(library.importUri)) {
         libraries.add(library);
-        registerKnownLibrary(library);
+        target.registerLibrary(library);
         requestedLibraries.add(uri);
         requestedLibrariesFileUri.add(library.fileUri);
       }
@@ -301,7 +290,7 @@ severity: $severity
     //
     // Create dill library builder (adds it to a map where it's fetched
     // again momentarily).
-    registerKnownLibrary(library);
+    target.registerLibrary(library);
     // Set up the dill library builder (fetch it from the map again, add it to
     // another map and setup some auxiliary things).
     return read(library.importUri, -1);
@@ -316,19 +305,19 @@ severity: $severity
   }
 
   void finalizeExports({bool suppressFinalizationErrors: false}) {
-    for (DillLibraryBuilder builder in libraryBuilders) {
-      builder.markAsReadyToFinalizeExports(
+    for (LibraryBuilder builder in builders.values) {
+      DillLibraryBuilder library = builder as DillLibraryBuilder;
+      library.markAsReadyToFinalizeExports(
           suppressFinalizationErrors: suppressFinalizationErrors);
     }
   }
 
   @override
   ClassBuilder computeClassBuilderFromTargetClass(Class cls) {
     Library kernelLibrary = cls.enclosingLibrary;
-    LibraryBuilder? library = lookupLibraryBuilder(kernelLibrary.importUri);
+    LibraryBuilder? library = builders[kernelLibrary.importUri];
     if (library == null) {
-      library =
-          currentSourceLoader?.lookupLibraryBuilder(kernelLibrary.importUri);
+      library = currentSourceLoader?.builders[kernelLibrary.importUri];
     }
     return library!.lookupLocalMember(cls.name, required: true) as ClassBuilder;
   }
@@ -337,28 +326,4 @@ severity: $severity
   TypeBuilder computeTypeBuilder(DartType type) {
     return type.accept(new TypeBuilderComputer(this));
   }
-
-  bool containsLibraryBuilder(Uri importUri) =>
-      _builders.containsKey(importUri);
-
-  @override
-  DillLibraryBuilder? lookupLibraryBuilder(Uri importUri) =>
-      _builders[importUri];
-
-  Iterable<DillLibraryBuilder> get libraryBuilders => _builders.values;
-
-  Iterable<Uri> get libraryImportUris => _builders.keys;
-
-  void registerLibraryBuilder(DillLibraryBuilder libraryBuilder) {
-    Uri importUri = libraryBuilder.importUri;
-    libraryBuilder.loader = this;
-    if (importUri.scheme == "dart" && importUri.path == "core") {
-      _coreLibrary = libraryBuilder;
-    }
-    _builders[importUri] = libraryBuilder;
-  }
-
-  DillLibraryBuilder? deregisterLibraryBuilder(Uri importUri) {
-    return _builders.remove(importUri);
-  }
 }

pkg/front_end/lib/src/fasta/dill/dill_target.dart

@@ -4,7 +4,7 @@
 
 import 'package:_fe_analyzer_shared/src/messages/severity.dart' show Severity;
 
-import 'package:kernel/ast.dart' show Source;
+import 'package:kernel/ast.dart' show Library, Source;
 
 import 'package:kernel/target/targets.dart' show Target;
 
@@ -20,11 +20,16 @@ import '../uri_translator.dart' show UriTranslator;
 
 import '../target_implementation.dart' show TargetImplementation;
 
+import 'dill_library_builder.dart' show DillLibraryBuilder;
+
 import 'dill_loader.dart' show DillLoader;
 
 class DillTarget extends TargetImplementation {
   final Ticker ticker;
 
+  final Map<Uri, DillLibraryBuilder> _knownLibraryBuilders =
+      <Uri, DillLibraryBuilder>{};
+
   bool isLoaded = false;
 
   late final DillLoader loader;
@@ -87,4 +92,24 @@ class DillTarget extends TargetImplementation {
     }
     isLoaded = true;
   }
+
+  /// Returns the [DillLibraryBuilder] corresponding to [uri].
+  ///
+  /// The [DillLibraryBuilder] is pulled from [_knownLibraryBuilders].
+  DillLibraryBuilder createLibraryBuilder(Uri uri) {
+    DillLibraryBuilder libraryBuilder =
+        _knownLibraryBuilders.remove(uri) as DillLibraryBuilder;
+    // ignore: unnecessary_null_comparison
+    assert(libraryBuilder != null, "No library found for $uri.");
+    return libraryBuilder;
+  }
+
+  void registerLibrary(Library library) {
+    _knownLibraryBuilders[library.importUri] =
+        new DillLibraryBuilder(library, loader);
+  }
+
+  void releaseAncillaryResources() {
+    _knownLibraryBuilders.clear();
+  }
 }