Fasta targets and loaders.

pkg/fasta/lib/src/source/source_loader.dart

+// Copyright (c) 2016, 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.
+
+library fasta.source_loader;
+
+import 'dart:async' show
+    Future;
+
+import 'dart:io' show
+    FileSystemException;
+
+import 'package:dart_scanner/io.dart' show
+    readBytesFromFile;
+
+import 'package:dart_scanner/src/token.dart' show
+    Token;
+
+import 'package:dart_scanner/dart_scanner.dart' show
+    scan;
+
+import 'package:dart_parser/src/class_member_parser.dart' show
+    ClassMemberParser;
+
+import 'package:kernel/ast.dart' show
+    Program;
+
+import 'package:kernel/class_hierarchy.dart' show
+    ClassHierarchy;
+
+import 'package:kernel/core_types.dart' show
+    CoreTypes;
+
+import '../errors.dart' show
+    inputError;
+
+import '../export.dart' show
+    Export;
+
+import '../analyzer/element_store.dart' show
+    ElementStore;
+
+import '../builder/builder.dart' show
+    Builder,
+    ClassBuilder,
+    LibraryBuilder;
+
+import 'outline_builder.dart' show
+    OutlineBuilder;
+
+import '../loader.dart' show
+    Loader;
+
+import '../target_implementation.dart' show
+    TargetImplementation;
+
+import 'diet_listener.dart' show
+    DietListener;
+
+import 'diet_parser.dart' show
+    DietParser;
+
+import 'source_library_builder.dart' show
+    SourceLibraryBuilder;
+
+import '../ast_kind.dart' show
+    AstKind;
+
+class SourceLoader<L> extends Loader<L> {
+  // Used when building directly to kernel.
+  ClassHierarchy hierarchy;
+  CoreTypes coreTypes;
+
+  // Used when building analyzer ASTs.
+  ElementStore elementStore;
+
+  SourceLoader(TargetImplementation target)
+      : super(target);
+
+  Future<Token> tokenize(SourceLibraryBuilder library) async {
+    Uri uri = library.uri;
+    if (uri.scheme != "file") {
+      uri = target.translateUri(uri);
+      if (uri == null) {
+        print("Skipping ${library.uri}");
+        return null;
+      }
+      library.fileUri = uri;
+    }
+    try {
+      List<int> bytes = await readBytesFromFile(uri);
+      byteCount += bytes.length - 1;
+      return scan(bytes).tokens;
+    } on FileSystemException catch (e) {
+      String message = e.message;
+      String osMessage = e.osError?.message;
+      if (osMessage != null && osMessage.isNotEmpty) {
+        message = osMessage;
+      }
+      return inputError(uri, -1, message);
+    }
+  }
+
+  Future<Null> buildOutline(SourceLibraryBuilder library) async {
+    Token tokens = await tokenize(library);
+    if (tokens == null) return;
+    OutlineBuilder listener = new OutlineBuilder(library);
+    new ClassMemberParser(listener).parseUnit(tokens);
+  }
+
+  Future<Null> buildBody(LibraryBuilder library, AstKind astKind) async {
+    if (library is SourceLibraryBuilder) {
+      Token tokens = await tokenize(library);
+      if (tokens == null) return;
+      DietListener listener = new DietListener(
+          library, elementStore, hierarchy, coreTypes, astKind);
+      DietParser parser = new DietParser(listener);
+      parser.parseUnit(tokens);
+      for (SourceLibraryBuilder part in library.parts) {
+        Token tokens = await tokenize(part);
+        if (tokens != null) {
+          parser.parseUnit(tokens);
+        }
+      }
+    }
+  }
+
+  void resolveParts() {
+    List<Uri> parts = <Uri>[];
+    builders.forEach((Uri uri, LibraryBuilder library) {
+        if (library is SourceLibraryBuilder) {
+          if (library.isPart) {
+            library.validatePart();
+            parts.add(uri);
+          } else {
+            library.includeParts();
+          }
+        }
+    });
+    parts.forEach(builders.remove);
+    ticker.logMs("Resolved parts");
+  }
+
+  void computeLibraryScopes() {
+    Set<LibraryBuilder> exporters = new Set<LibraryBuilder>();
+    Set<LibraryBuilder> exportees = new Set<LibraryBuilder>();
+    builders.forEach((Uri uri, LibraryBuilder library) {
+      if (library is SourceLibraryBuilder) {
+        library.buildInitialScopes();
+      }
+      if (library.exporters.isNotEmpty) {
+        exportees.add(library);
+        for (Export exporter in library.exporters) {
+          exporters.add(exporter.exporter);
+        }
+      }
+    });
+    Set<SourceLibraryBuilder> both = new Set<SourceLibraryBuilder>();
+    for (LibraryBuilder exported in exportees) {
+      if (exporters.contains(exported)) {
+        both.add(exported);
+      }
+      for (Export export in exported.exporters) {
+        exported.exports.forEach(export.addToExportScope);
+      }
+    }
+    bool wasChanged = false;
+    do {
+      wasChanged = false;
+      for (SourceLibraryBuilder exported in both) {
+        for (Export export in exported.exporters) {
+          SourceLibraryBuilder exporter = export.exporter;
+          exported.exports.forEach((String name, Builder member) {
+            if (exporter.addToExportScope(name, member)) {
+              wasChanged = true;
+            }
+          });
+        }
+      }
+    } while (wasChanged);
+    builders.forEach((Uri uri, LibraryBuilder library) {
+      if (library is SourceLibraryBuilder) {
+        library.addImportsToScope();
+      }
+    });
+    ticker.logMs("Computed library scopes");
+    // debugPrintExports();
+  }
+
+  void debugPrintExports() {
+    builders.forEach((Uri uri, SourceLibraryBuilder library) {
+      Set<Builder> members = new Set<Builder>();
+      library.members.forEach((String name, Builder member) {
+        while (member != null) {
+          members.add(member);
+          member = member.next;
+        }
+      });
+      List<String> exports = <String>[];
+      library.exports.forEach((String name, Builder member) {
+        while (member != null) {
+          if (!members.contains(member)) {
+            exports.add(name);
+          }
+          member = member.next;
+        }
+      });
+      if (exports.isNotEmpty) {
+        print("$uri exports $exports");
+      }
+    });
+  }
+
+  void resolveTypes() {
+    int typeCount = 0;
+    builders.forEach((Uri uri, LibraryBuilder library) {
+      typeCount += library.resolveTypes(null);
+    });
+    ticker.logMs("Resolved $typeCount types");
+  }
+
+  void convertConstructors() {
+    int count = 0;
+    builders.forEach((Uri uri, LibraryBuilder library) {
+      count += library.convertConstructors(null);
+    });
+    ticker.logMs("Converted $count constructors");
+  }
+
+  void finishStaticInvocations() {
+    int count = 0;
+    builders.forEach((Uri uri, LibraryBuilder library) {
+      count += library.finishStaticInvocations();
+    });
+    ticker.logMs("Finished static invocations $count");
+  }
+
+  void resolveConstructors() {
+    int count = 0;
+    builders.forEach((Uri uri, LibraryBuilder library) {
+      count += library.resolveConstructors(null);
+    });
+    ticker.logMs("Resolved $count constructors");
+  }
+
+  /// Returns all the supertypes (including interfaces) of [cls]
+  /// transitively. Includes [cls].
+  Set<ClassBuilder> allSupertypes(ClassBuilder cls) {
+    int length = 0;
+    Set<ClassBuilder> result = new Set<ClassBuilder>()..add(cls);
+    while (length != result.length) {
+      length = result.length;
+      result.addAll(directSupertypes(result));
+    }
+    return result;
+  }
+
+  /// Returns the direct supertypes (including interface) of [classes]. A class
+  /// from [classes] is only included if it is a supertype of one of the other
+  /// classes in [classes].
+  Set<ClassBuilder> directSupertypes(Iterable<ClassBuilder> classes) {
+    Set<ClassBuilder> result = new Set<ClassBuilder>();
+    for (ClassBuilder cls in classes) {
+      target.addDirectSupertype(cls, result);
+    }
+    return result;
+  }
+
+  /// Computes a set of classes that may have cycles. The set is empty if there
+  /// are no cycles. If the set isn't empty, it will include supertypes of
+  /// classes with cycles, as well as the classes with cycles.
+  ///
+  /// It is assumed that [classes] is a transitive closure with respect to
+  /// supertypes.
+  Iterable<ClassBuilder> cyclicCandidates(Iterable<ClassBuilder> classes) {
+    // The candidates are found by a fixed-point computation.
+    //
+    // On each iteration, the classes that have no supertypes in the input set
+    // will be removed.
+    //
+    // If there are no cycles, eventually, the set will converge on Object, and
+    // the next iteration will make the set empty (as Object has no
+    // supertypes).
+    //
+    // On the other hand, if there is a cycle, the cycle will remain in the
+    // set, and so will its supertypes, and eventually the input and output set
+    // will have the same length.
+    Iterable<ClassBuilder> input = const [];
+    Iterable<ClassBuilder> output = classes;
+    while (input.length != output.length) {
+      input = output;
+      output = directSupertypes(input);
+    }
+    return output;
+  }
+
+  void checkSemantics() {
+    List<ClassBuilder> allClasses = target.collectAllClasses();
+    Iterable<ClassBuilder> candidates = cyclicCandidates(allClasses);
+    Map<ClassBuilder, Set<ClassBuilder>> realCycles =
+        <ClassBuilder, Set<ClassBuilder>>{};
+    for (ClassBuilder cls in candidates) {
+      Set<ClassBuilder> cycles = cyclicCandidates(allSupertypes(cls));
+      if (cycles.isNotEmpty) {
+        realCycles[cls] = cycles;
+      }
+    }
+    Set<ClassBuilder> reported = new Set<ClassBuilder>();
+    realCycles.forEach((ClassBuilder cls, Set<ClassBuilder> cycles) {
+      target.breakCycle(cls);
+      if (reported.add(cls)) {
+        List<ClassBuilder> involved = <ClassBuilder>[];
+        for (ClassBuilder cls in cycles) {
+          if (realCycles.containsKey(cls)) {
+            involved.add(cls);
+            reported.add(cls);
+          }
+        }
+        print("${cls.name} is a supertype of itself via "
+            "${involved.map((c) => c.name).join(' ')}");
+      }
+    });
+    ticker.logMs("Found cycles");
+  }
+
+  void buildProgram() {
+    builders.forEach((Uri uri, LibraryBuilder library) {
+      if (library is SourceLibraryBuilder) {
+        libraries.add(library.build());
+      }
+    });
+    ticker.logMs("Built program");
+  }
+
+  void buildElementStore() {
+    elementStore = new ElementStore(coreLibrary, builders);
+    ticker.logMs("Built analyzer element model.");
+  }
+
+  void computeHierarchy(Program program) {
+    hierarchy = new ClassHierarchy(program);
+    ticker.logMs("Computed class hierarchy");
+    coreTypes = new CoreTypes(program);
+    ticker.logMs("Computed core types");
+  }
+}