Reland "[cfe] Move createLibraryBuilder methods to loaders"

This is a reland of 0e7d0f5

Original change's description:
> [cfe] Move createLibraryBuilder methods to loaders
>
> Change-Id: I912ab0494cc91a4a2b665a24a7d55362402542ff
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/216940
> Commit-Queue: Johnni Winther <[email protected]>
> Reviewed-by: Jens Johansen <[email protected]>

Change-Id: Ibb25413423a9bbd67c8788f9adce95c201ac8ebf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/217603
Reviewed-by: Jens Johansen <[email protected]>
Commit-Queue: Johnni Winther <[email protected]>

Author: johnniwinther

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

@@ -47,6 +47,9 @@ 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>{};
 
   final Queue<DillLibraryBuilder> _unparsedLibraries =
@@ -88,6 +91,16 @@ class DillLoader extends Loader {
 
   Ticker get ticker => target.ticker;
 
+  void registerKnownLibrary(Library library) {
+    _knownLibraryBuilders[library.importUri] =
+        new DillLibraryBuilder(library, this);
+  }
+
+  // TODO(johnniwinther): This is never called!?!
+  void releaseAncillaryResources() {
+    _knownLibraryBuilders.clear();
+  }
+
   /// 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
   /// [fileUri].
@@ -100,32 +113,35 @@ 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 builder = _builders.putIfAbsent(uri, () {
-      DillLibraryBuilder library = target.createLibraryBuilder(uri);
-      assert(library.loader == this);
+    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);
       if (uri.scheme == "dart") {
         if (uri.path == "core") {
-          _coreLibrary = library;
+          _coreLibrary = libraryBuilder;
         }
       }
       {
         // Add any additional logic after this block. Setting the
         // firstSourceUri and first library should be done as early as
         // possible.
         firstSourceUri ??= uri;
-        first ??= library;
+        first ??= libraryBuilder;
       }
-      if (_coreLibrary == library) {
+      if (_coreLibrary == libraryBuilder) {
         target.loadExtraRequiredLibraries(this);
       }
       if (target.backendTarget.mayDefineRestrictedType(uri)) {
-        library.mayImplementRestrictedTypes = true;
+        libraryBuilder.mayImplementRestrictedTypes = true;
       }
-      _unparsedLibraries.addLast(library);
-      return library;
-    });
+      _unparsedLibraries.addLast(libraryBuilder);
+    }
     if (accessor != null) {
-      builder.recordAccess(charOffset, noLength, accessor.fileUri);
+      libraryBuilder.recordAccess(charOffset, noLength, accessor.fileUri);
       if (!accessor.isPatch &&
           !accessor.isPart &&
           !target.backendTarget
@@ -134,7 +150,7 @@ class DillLoader extends Loader {
             noLength, accessor.fileUri);
       }
     }
-    return builder;
+    return libraryBuilder;
   }
 
   void _ensureCoreLibrary() {
@@ -259,7 +275,7 @@ severity: $severity
       Uri uri = library.importUri;
       if (filter == null || filter(library.importUri)) {
         libraries.add(library);
-        target.registerLibrary(library);
+        registerKnownLibrary(library);
         requestedLibraries.add(uri);
         requestedLibrariesFileUri.add(library.fileUri);
       }
@@ -285,7 +301,7 @@ severity: $severity
     //
     // Create dill library builder (adds it to a map where it's fetched
     // again momentarily).
-    target.registerLibrary(library);
+    registerKnownLibrary(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);

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 Library, Source;
+import 'package:kernel/ast.dart' show Source;
 
 import 'package:kernel/target/targets.dart' show Target;
 
@@ -20,16 +20,11 @@ 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;
@@ -92,23 +87,4 @@ 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)!;
-    // 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();
-  }
 }

pkg/front_end/lib/src/fasta/incremental_compiler.dart

@@ -1426,7 +1426,7 @@ class IncrementalCompiler implements IncrementalKernelGenerator {
         for (Library lib in module.libraries) {
           if (!dillLoadedData!.loader.containsLibraryBuilder(lib.importUri)) {
             dillLoadedData!.loader.libraries.add(lib);
-            dillLoadedData!.registerLibrary(lib);
+            dillLoadedData!.loader.registerKnownLibrary(lib);
             reusedLibraries.add(dillLoadedData!.loader.read(lib.importUri, -1));
             usedComponent = true;
           }

pkg/front_end/lib/src/fasta/kernel/kernel_target.dart

@@ -40,7 +40,6 @@ import '../builder/type_variable_builder.dart';
 import '../builder/void_type_declaration_builder.dart';
 import '../compiler_context.dart' show CompilerContext;
 import '../crash.dart' show withCrashReporting;
-import '../dill/dill_library_builder.dart' show DillLibraryBuilder;
 import '../dill/dill_member_builder.dart' show DillMemberBuilder;
 import '../dill/dill_target.dart' show DillTarget;
 import '../kernel/constructor_tearoff_lowering.dart';
@@ -50,16 +49,11 @@ import '../messages.dart'
         FormattedMessage,
         LocatedMessage,
         Message,
-        messageAgnosticWithStrongDillLibrary,
-        messageAgnosticWithWeakDillLibrary,
         messageConstConstructorLateFinalFieldCause,
         messageConstConstructorLateFinalFieldError,
         messageConstConstructorNonFinalField,
         messageConstConstructorNonFinalFieldCause,
         messageConstConstructorRedirectionToNonConst,
-        messageInvalidNnbdDillLibrary,
-        messageStrongWithWeakDillLibrary,
-        messageWeakWithStrongDillLibrary,
         noLength,
         templateFieldNonNullableNotInitializedByConstructorError,
         templateFieldNonNullableWithoutInitializerError,
@@ -72,8 +66,7 @@ import '../problems.dart' show unhandled;
 import '../scope.dart' show AmbiguousBuilder;
 import '../source/name_scheme.dart';
 import '../source/source_class_builder.dart' show SourceClassBuilder;
-import '../source/source_library_builder.dart'
-    show LanguageVersion, SourceLibraryBuilder;
+import '../source/source_library_builder.dart' show SourceLibraryBuilder;
 import '../source/source_loader.dart' show SourceLoader;
 import '../target_implementation.dart' show TargetImplementation;
 import '../ticker.dart' show Ticker;
@@ -368,90 +361,6 @@ class KernelTarget extends TargetImplementation {
     return entryPoint;
   }
 
-  /// Creates a [LibraryBuilder] corresponding to [uri], if one doesn't exist
-  /// already.
-  ///
-  /// [fileUri] must not be null and is a URI that can be passed to FileSystem
-  /// to locate the corresponding file.
-  ///
-  /// [origin] is non-null if the created library is a patch to [origin].
-  ///
-  /// [packageUri] is the base uri for the package which the library belongs to.
-  /// For instance 'package:foo'.
-  ///
-  /// This is used to associate libraries in for instance the 'bin' and 'test'
-  /// folders of a package source with the package uri of the 'lib' folder.
-  ///
-  /// If the [packageUri] is `null` the package association of this library is
-  /// based on its [importUri].
-  ///
-  /// For libraries with a 'package:' [importUri], the package path must match
-  /// the path in the [importUri]. For libraries with a 'dart:' [importUri] the
-  /// [packageUri] must be `null`.
-  ///
-  /// [packageLanguageVersion] is the language version defined by the package
-  /// which the library belongs to, or the current sdk version if the library
-  /// doesn't belong to a package.
-  LibraryBuilder createLibraryBuilder(
-      Uri uri,
-      Uri fileUri,
-      Uri? packageUri,
-      LanguageVersion packageLanguageVersion,
-      SourceLibraryBuilder? origin,
-      Library? referencesFrom,
-      bool? referenceIsPartOwner) {
-    if (dillTarget.isLoaded) {
-      DillLibraryBuilder? builder = dillTarget.loader.lookupLibraryBuilder(uri);
-      if (builder != null) {
-        if (!builder.isNonNullableByDefault &&
-            (loader.nnbdMode == NnbdMode.Strong ||
-                loader.nnbdMode == NnbdMode.Agnostic)) {
-          loader.registerStrongOptOutLibrary(builder);
-        } else {
-          NonNullableByDefaultCompiledMode libraryMode =
-              builder.library.nonNullableByDefaultCompiledMode;
-          if (libraryMode == NonNullableByDefaultCompiledMode.Invalid) {
-            loader.registerNnbdMismatchLibrary(
-                builder, messageInvalidNnbdDillLibrary);
-          } else {
-            switch (loader.nnbdMode) {
-              case NnbdMode.Weak:
-                if (libraryMode != NonNullableByDefaultCompiledMode.Agnostic &&
-                    libraryMode != NonNullableByDefaultCompiledMode.Weak) {
-                  loader.registerNnbdMismatchLibrary(
-                      builder, messageWeakWithStrongDillLibrary);
-                }
-                break;
-              case NnbdMode.Strong:
-                if (libraryMode != NonNullableByDefaultCompiledMode.Agnostic &&
-                    libraryMode != NonNullableByDefaultCompiledMode.Strong) {
-                  loader.registerNnbdMismatchLibrary(
-                      builder, messageStrongWithWeakDillLibrary);
-                }
-                break;
-              case NnbdMode.Agnostic:
-                if (libraryMode != NonNullableByDefaultCompiledMode.Agnostic) {
-                  if (libraryMode == NonNullableByDefaultCompiledMode.Strong) {
-                    loader.registerNnbdMismatchLibrary(
-                        builder, messageAgnosticWithStrongDillLibrary);
-                  } else {
-                    loader.registerNnbdMismatchLibrary(
-                        builder, messageAgnosticWithWeakDillLibrary);
-                  }
-                }
-                break;
-            }
-          }
-        }
-        return builder;
-      }
-    }
-    return new SourceLibraryBuilder(
-        uri, fileUri, packageUri, packageLanguageVersion, loader, origin,
-        referencesFrom: referencesFrom,
-        referenceIsPartOwner: referenceIsPartOwner);
-  }
-
   /// Returns classes defined in libraries in [loader].
   List<SourceClassBuilder> collectMyClasses() {
     List<SourceClassBuilder> result = <SourceClassBuilder>[];