pkg/compiler/lib/src/js_model/js_strategy.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.

library dart2js.js_model.strategy;

import 'package:kernel/ast.dart' as ir;

import '../backend_strategy.dart';
import '../common.dart';
import '../common/codegen.dart' show CodegenRegistry, CodegenResults;
import '../common/tasks.dart';
import '../common/work.dart';
import '../compiler.dart';
import '../deferred_load.dart' hide WorkItem;
import '../dump_info.dart';
import '../elements/entities.dart';
import '../enqueue.dart';
import '../io/kernel_source_information.dart'
    show KernelSourceInformationStrategy;
import '../io/source_information.dart';
import '../inferrer/abstract_value_domain.dart';
import '../inferrer/type_graph_inferrer.dart';
import '../inferrer/types.dart';
import '../js/js_source_mapping.dart';
import '../js_backend/backend.dart';
import '../js_backend/inferred_data.dart';
import '../js_backend/interceptor_data.dart';
import '../js_backend/native_data.dart';
import '../js_backend/namer.dart' show ModularNamer;
import '../js_emitter/code_emitter_task.dart' show ModularEmitter;
import '../kernel/kernel_strategy.dart';
import '../native/behavior.dart';
import '../options.dart';
import '../serialization/serialization.dart';
import '../ssa/builder_kernel.dart';
import '../ssa/nodes.dart';
import '../ssa/ssa.dart';
import '../ssa/types.dart';
import '../universe/codegen_world_builder.dart';
import '../universe/selector.dart';
import '../universe/world_builder.dart';
import '../universe/world_impact.dart';
import '../world.dart';
import 'closure.dart';
import 'element_map.dart';
import 'element_map_impl.dart';
import 'js_world.dart';
import 'js_world_builder.dart';
import 'locals.dart';

class JsBackendStrategy implements BackendStrategy {
  final Compiler _compiler;
  JsKernelToElementMap _elementMap;

  JsBackendStrategy(this._compiler);

  @deprecated
  JsToElementMap get elementMap {
    assert(_elementMap != null,
        "JsBackendStrategy.elementMap has not been created yet.");
    return _elementMap;
  }

  @override
  JClosedWorld createJClosedWorld(
      KClosedWorld closedWorld, OutputUnitData outputUnitData) {
    KernelFrontEndStrategy strategy = _compiler.frontendStrategy;
    _elementMap = new JsKernelToElementMap(
        _compiler.reporter,
        _compiler.environment,
        strategy.elementMap,
        closedWorld.liveMemberUsage,
        closedWorld.annotationsData);
    GlobalLocalsMap _globalLocalsMap = new GlobalLocalsMap();
    ClosureDataBuilder closureDataBuilder = new ClosureDataBuilder(
        _elementMap, _globalLocalsMap, _compiler.options);
    JsClosedWorldBuilder closedWorldBuilder = new JsClosedWorldBuilder(
        _elementMap,
        _globalLocalsMap,
        closureDataBuilder,
        _compiler.options,
        _compiler.abstractValueStrategy);
    return closedWorldBuilder.convertClosedWorld(
        closedWorld, strategy.closureModels, outputUnitData);
  }

  @override
  void registerJClosedWorld(covariant JsClosedWorld closedWorld) {
    _elementMap = closedWorld.elementMap;
  }

  @override
  SourceInformationStrategy get sourceInformationStrategy {
    if (!_compiler.options.generateSourceMap) {
      return const JavaScriptSourceInformationStrategy();
    }
    return new KernelSourceInformationStrategy(this);
  }

  @override
  SsaBuilder createSsaBuilder(
      CompilerTask task, SourceInformationStrategy sourceInformationStrategy) {
    return new KernelSsaBuilder(
        task,
        _compiler.options,
        _compiler.reporter,
        _compiler.dumpInfoTask,
        // ignore:deprecated_member_use_from_same_package
        elementMap,
        sourceInformationStrategy);
  }

  @override
  WorkItemBuilder createCodegenWorkItemBuilder(
      JClosedWorld closedWorld, CodegenResults codegenResults) {
    assert(_elementMap != null,
        "JsBackendStrategy.elementMap has not been created yet.");
    return new KernelCodegenWorkItemBuilder(
        _compiler.backend,
        closedWorld,
        codegenResults,
        new ClosedEntityLookup(_elementMap),
        // TODO(johnniwinther): Avoid the need for a [ComponentLookup]. This
        // is caused by some type masks holding a kernel node for using in
        // tracing.
        new ComponentLookup(_elementMap.programEnv.mainComponent));
  }

  @override
  CodegenWorldBuilder createCodegenWorldBuilder(
      NativeBasicData nativeBasicData,
      JClosedWorld closedWorld,
      SelectorConstraintsStrategy selectorConstraintsStrategy,
      OneShotInterceptorData oneShotInterceptorData) {
    return new CodegenWorldBuilderImpl(
        closedWorld, selectorConstraintsStrategy, oneShotInterceptorData);
  }

  @override
  SourceSpan spanFromSpannable(Spannable spannable, Entity currentElement) {
    return _elementMap.getSourceSpan(spannable, currentElement);
  }

  @override
  TypesInferrer createTypesInferrer(
      JClosedWorld closedWorld, InferredDataBuilder inferredDataBuilder) {
    return new TypeGraphInferrer(_compiler, closedWorld, inferredDataBuilder);
  }

  @override
  void prepareCodegenReader(DataSource source) {
    source.registerEntityReader(new ClosedEntityReader(_elementMap));
    source.registerEntityLookup(new ClosedEntityLookup(_elementMap));
    source.registerComponentLookup(
        new ComponentLookup(_elementMap.programEnv.mainComponent));
  }

  @override
  EntityWriter forEachCodegenMember(void Function(MemberEntity member) f) {
    int earlyMemberIndexLimit = _elementMap.prepareForCodegenSerialization();
    ClosedEntityWriter entityWriter =
        new ClosedEntityWriter(_elementMap, earlyMemberIndexLimit);
    for (int memberIndex = 0;
        memberIndex < _elementMap.members.length;
        memberIndex++) {
      MemberEntity member = _elementMap.members.getEntity(memberIndex);
      if (member == null || member.isAbstract) continue;
      f(member);
    }
    return entityWriter;
  }
}

class KernelCodegenWorkItemBuilder implements WorkItemBuilder {
  final JavaScriptBackend _backend;
  final JClosedWorld _closedWorld;
  final CodegenResults _codegenResults;
  final EntityLookup _entityLookup;
  final ComponentLookup _componentLookup;

  KernelCodegenWorkItemBuilder(this._backend, this._closedWorld,
      this._codegenResults, this._entityLookup, this._componentLookup);

  @override
  WorkItem createWorkItem(MemberEntity entity) {
    if (entity.isAbstract) return null;
    return new KernelCodegenWorkItem(_backend, _closedWorld, _codegenResults,
        _entityLookup, _componentLookup, entity);
  }
}

class KernelCodegenWorkItem extends WorkItem {
  final JavaScriptBackend _backend;
  final JClosedWorld _closedWorld;
  final CodegenResults _codegenResults;
  final EntityLookup _entityLookup;
  final ComponentLookup _componentLookup;
  @override
  final MemberEntity element;

  KernelCodegenWorkItem(this._backend, this._closedWorld, this._codegenResults,
      this._entityLookup, this._componentLookup, this.element);

  @override
  WorldImpact run() {
    return _backend.generateCode(
        this, _closedWorld, _codegenResults, _entityLookup, _componentLookup);
  }
}

/// Task for building SSA from kernel IR loaded from .dill.
class KernelSsaBuilder implements SsaBuilder {
  final CompilerTask _task;
  final CompilerOptions _options;
  final DiagnosticReporter _reporter;
  final DumpInfoTask _dumpInfoTask;
  final JsToElementMap _elementMap;
  final SourceInformationStrategy _sourceInformationStrategy;

  // TODO(johnniwinther,sra): Inlining decisions should not be based on the
  // order in which ssa graphs are built.
  FunctionInlineCache _inlineCache;

  KernelSsaBuilder(this._task, this._options, this._reporter,
      this._dumpInfoTask, this._elementMap, this._sourceInformationStrategy);

  @override
  HGraph build(
      MemberEntity member,
      JClosedWorld closedWorld,
      GlobalTypeInferenceResults results,
      CodegenInputs codegen,
      CodegenRegistry registry,
      ModularNamer namer,
      ModularEmitter emitter) {
    _inlineCache ??= new FunctionInlineCache(closedWorld.annotationsData);
    return _task.measure(() {
      KernelSsaGraphBuilder builder = new KernelSsaGraphBuilder(
          _options,
          _reporter,
          member,
          _elementMap.getMemberThisType(member),
          _dumpInfoTask,
          _elementMap,
          results,
          closedWorld,
          registry,
          namer,
          emitter,
          codegen.tracer,
          codegen.rtiEncoder,
          _sourceInformationStrategy,
          _inlineCache);
      return builder.build();
    });
  }
}

class KernelToTypeInferenceMapImpl implements KernelToTypeInferenceMap {
  final GlobalTypeInferenceResults _globalInferenceResults;
  GlobalTypeInferenceMemberResult _targetResults;

  KernelToTypeInferenceMapImpl(
      MemberEntity target, this._globalInferenceResults) {
    _targetResults = _resultOf(target);
  }

  GlobalTypeInferenceMemberResult _resultOf(MemberEntity e) =>
      _globalInferenceResults
          .resultOfMember(e is ConstructorBodyEntity ? e.constructor : e);

  @override
  AbstractValue getReturnTypeOf(FunctionEntity function) {
    return AbstractValueFactory.inferredReturnTypeForElement(
        function, _globalInferenceResults);
  }

  @override
  AbstractValue receiverTypeOfInvocation(
      ir.MethodInvocation node, AbstractValueDomain abstractValueDomain) {
    return _targetResults.typeOfSend(node);
  }

  @override
  AbstractValue receiverTypeOfGet(ir.PropertyGet node) {
    return _targetResults.typeOfSend(node);
  }

  @override
  AbstractValue receiverTypeOfDirectGet(ir.DirectPropertyGet node) {
    return _targetResults.typeOfSend(node);
  }

  @override
  AbstractValue receiverTypeOfSet(
      ir.PropertySet node, AbstractValueDomain abstractValueDomain) {
    return _targetResults.typeOfSend(node);
  }

  @override
  AbstractValue typeOfListLiteral(
      ir.ListLiteral listLiteral, AbstractValueDomain abstractValueDomain) {
    return _globalInferenceResults.typeOfListLiteral(listLiteral) ??
        abstractValueDomain.dynamicType;
  }

  @override
  AbstractValue typeOfIterator(ir.ForInStatement node) {
    return _targetResults.typeOfIterator(node);
  }

  @override
  AbstractValue typeOfIteratorCurrent(ir.ForInStatement node) {
    return _targetResults.typeOfIteratorCurrent(node);
  }

  @override
  AbstractValue typeOfIteratorMoveNext(ir.ForInStatement node) {
    return _targetResults.typeOfIteratorMoveNext(node);
  }

  @override
  bool isJsIndexableIterator(
      ir.ForInStatement node, AbstractValueDomain abstractValueDomain) {
    AbstractValue mask = typeOfIterator(node);
    return abstractValueDomain.isJsIndexableAndIterable(mask).isDefinitelyTrue;
  }

  @override
  AbstractValue inferredIndexType(ir.ForInStatement node) {
    return AbstractValueFactory.inferredResultTypeForSelector(
        new Selector.index(), typeOfIterator(node), _globalInferenceResults);
  }

  @override
  AbstractValue getInferredTypeOf(MemberEntity member) {
    return AbstractValueFactory.inferredTypeForMember(
        member, _globalInferenceResults);
  }

  @override
  AbstractValue getInferredTypeOfParameter(Local parameter) {
    return AbstractValueFactory.inferredTypeForParameter(
        parameter, _globalInferenceResults);
  }

  @override
  AbstractValue resultTypeOfSelector(Selector selector, AbstractValue mask) {
    return AbstractValueFactory.inferredResultTypeForSelector(
        selector, mask, _globalInferenceResults);
  }

  @override
  AbstractValue typeFromNativeBehavior(
      NativeBehavior nativeBehavior, JClosedWorld closedWorld) {
    return AbstractValueFactory.fromNativeBehavior(nativeBehavior, closedWorld);
  }
}