| // Copyright (c) 2022, 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 'package:dart2wasm/class_info.dart'; |
| import 'package:dart2wasm/code_generator.dart'; |
| import 'package:dart2wasm/translator.dart'; |
| |
| import 'package:kernel/ast.dart'; |
| import 'package:kernel/core_types.dart'; |
| |
| import 'package:wasm_builder/wasm_builder.dart' as w; |
| |
| class InterfaceTypeEnvironment { |
| final Map<TypeParameter, int> typeOffsets = {}; |
| |
| void _add(InterfaceType type) { |
| Class cls = type.classNode; |
| if (typeOffsets.containsKey(cls)) { |
| return; |
| } |
| int i = 0; |
| for (TypeParameter typeParameter in cls.typeParameters) { |
| typeOffsets[typeParameter] = i++; |
| } |
| } |
| |
| int lookup(TypeParameter typeParameter) => typeOffsets[typeParameter]!; |
| } |
| |
| /// Helper class for building runtime types. |
| class Types { |
| final Translator translator; |
| late final typeClassInfo = translator.classInfo[translator.typeClass]!; |
| late final w.ValueType typeListExpectedType = classAndFieldToType( |
| translator.interfaceTypeClass, FieldIndex.interfaceTypeTypeArguments); |
| late final w.ValueType namedParametersExpectedType = classAndFieldToType( |
| translator.functionTypeClass, FieldIndex.functionTypeNamedParameters); |
| |
| /// A mapping from concrete subclass `classID` to [Map]s of superclass |
| /// `classID` and the necessary substitutions which must be performed to test |
| /// for a valid subtyping relationship. |
| late final Map<int, Map<int, List<DartType>>> typeRules = _buildTypeRules(); |
| |
| /// We will build the [interfaceTypeEnvironment] when building the |
| /// [typeRules]. |
| final InterfaceTypeEnvironment interfaceTypeEnvironment = |
| InterfaceTypeEnvironment(); |
| |
| /// Because we can't currently support [Map]s in our `TypeUniverse`, we have |
| /// to decompose [typeRules] into two [Map]s based on [List]s. |
| /// |
| /// [typeRulesSupers] is a [List] where the index in the list is a subclasses' |
| /// `classID` and the value at that index is a [List] of superclass |
| /// `classID`s. |
| late final List<List<int>> typeRulesSupers = _buildTypeRulesSupers(); |
| |
| /// [typeRulesSubstitutions] is a [List] where the index in the list is a |
| /// subclasses' `classID` and the value at that index is a [List] indexed by |
| /// the index of the superclasses' `classID` in [typeRulesSuper] and the value |
| /// at that index is a [List] of [DartType]s which must be substituted for the |
| /// subtyping relationship to be valid. |
| late final List<List<List<DartType>>> typeRulesSubstitutions = |
| _buildTypeRulesSubstitutions(); |
| |
| Types(this.translator); |
| |
| w.ValueType classAndFieldToType(Class cls, int fieldIndex) => |
| translator.classInfo[cls]!.struct.fields[fieldIndex].type.unpacked; |
| |
| Iterable<Class> _getConcreteSubtypes(Class cls) => |
| translator.subtypes.getSubtypesOf(cls).where((c) => !c.isAbstract); |
| |
| w.ValueType get nullableTypeType => typeClassInfo.nullableType; |
| |
| w.ValueType get nonNullableTypeType => typeClassInfo.nonNullableType; |
| |
| InterfaceType get namedParameterType => |
| InterfaceType(translator.namedParameterClass, Nullability.nonNullable); |
| |
| InterfaceType get typeType => |
| InterfaceType(translator.typeClass, Nullability.nonNullable); |
| |
| CoreTypes get coreTypes => translator.coreTypes; |
| |
| /// Builds a [Map<int, Map<int, List<DartType>>>] to store subtype |
| /// information. The first key is the class id of a subtype. This returns a |
| /// map where each key is the class id of a transitively implemented super |
| /// type and each value is a list of the necessary type substitutions required |
| /// for the subtyping relationship to be valid. |
| Map<int, Map<int, List<DartType>>> _buildTypeRules() { |
| List<ClassInfo> classes = translator.classes; |
| Map<int, Map<int, List<DartType>>> subtypeMap = {}; |
| for (ClassInfo classInfo in classes) { |
| ClassInfo superclassInfo = classInfo; |
| |
| // We don't need type rules for any class without a superclass, or for |
| // classes whose supertype is [Object]. The latter case will be handled |
| // directly in the subtype checking algorithm. |
| if (superclassInfo.cls == null || |
| superclassInfo.cls == coreTypes.objectClass) continue; |
| Class superclass = superclassInfo.cls!; |
| Iterable<Class> subclasses = |
| _getConcreteSubtypes(superclass).where((cls) => cls != superclass); |
| Iterable<InterfaceType> subtypes = subclasses.map( |
| (Class cls) => cls.getThisType(coreTypes, Nullability.nonNullable)); |
| for (InterfaceType subtype in subtypes) { |
| interfaceTypeEnvironment._add(subtype); |
| List<DartType>? typeArguments = translator.hierarchy |
| .getTypeArgumentsAsInstanceOf(subtype, superclass); |
| ClassInfo subclassInfo = translator.classInfo[subtype.classNode]!; |
| Map<int, List<DartType>> substitutionMap = |
| subtypeMap[subclassInfo.classId] ??= {}; |
| substitutionMap[superclassInfo.classId] = typeArguments ?? const []; |
| } |
| } |
| return subtypeMap; |
| } |
| |
| List<List<int>> _buildTypeRulesSupers() { |
| List<List<int>> typeRulesSupers = []; |
| for (int i = 0; i < translator.classInfoCollector.nextClassId; i++) { |
| List<int>? superclassIds = typeRules[i]?.keys.toList(); |
| if (superclassIds == null) { |
| typeRulesSupers.add(const []); |
| } else { |
| superclassIds.sort(); |
| typeRulesSupers.add(superclassIds); |
| } |
| } |
| return typeRulesSupers; |
| } |
| |
| List<List<List<DartType>>> _buildTypeRulesSubstitutions() { |
| List<List<List<DartType>>> typeRulesSubstitutions = []; |
| for (int i = 0; i < translator.classInfoCollector.nextClassId; i++) { |
| List<int> supers = typeRulesSupers[i]; |
| typeRulesSubstitutions.add(supers.isEmpty ? const [] : []); |
| for (int j = 0; j < supers.length; j++) { |
| int superId = supers[j]; |
| typeRulesSubstitutions.last.add(typeRules[i]![superId]!); |
| } |
| } |
| return typeRulesSubstitutions; |
| } |
| |
| /// Builds a map of subclasses to the transitive set of superclasses they |
| /// implement. |
| /// TODO(joshualitt): This implementation is just temporary. Eventually we |
| /// should move to a data structure more closely resembling [typeRules]. |
| w.ValueType makeTypeRulesSupers(w.Instructions b) { |
| w.ValueType expectedType = |
| translator.classInfo[translator.immutableListClass]!.nonNullableType; |
| DartType listIntType = InterfaceType(translator.immutableListClass, |
| Nullability.nonNullable, [translator.coreTypes.intNonNullableRawType]); |
| List<ListConstant> listIntConstant = []; |
| for (List<int> supers in typeRulesSupers) { |
| listIntConstant.add(ListConstant( |
| listIntType, supers.map((i) => IntConstant(i)).toList())); |
| } |
| DartType listListIntType = InterfaceType( |
| translator.immutableListClass, Nullability.nonNullable, [listIntType]); |
| translator.constants.instantiateConstant( |
| null, b, ListConstant(listListIntType, listIntConstant), expectedType); |
| return expectedType; |
| } |
| |
| /// Similar to the above, but provides the substitutions required for each |
| /// supertype. |
| /// TODO(joshualitt): Like [makeTypeRulesSupers], this is just temporary. |
| w.ValueType makeTypeRulesSubstitutions(w.Instructions b) { |
| w.ValueType expectedType = |
| translator.classInfo[translator.immutableListClass]!.nonNullableType; |
| DartType listTypeType = InterfaceType( |
| translator.immutableListClass, |
| Nullability.nonNullable, |
| [translator.typeClass.getThisType(coreTypes, Nullability.nonNullable)]); |
| DartType listListTypeType = InterfaceType( |
| translator.immutableListClass, Nullability.nonNullable, [listTypeType]); |
| DartType listListListTypeType = InterfaceType(translator.immutableListClass, |
| Nullability.nonNullable, [listListTypeType]); |
| List<ListConstant> substitutionsConstantL0 = []; |
| for (List<List<DartType>> substitutionsL1 in typeRulesSubstitutions) { |
| List<ListConstant> substitutionsConstantL1 = []; |
| for (List<DartType> substitutionsL2 in substitutionsL1) { |
| substitutionsConstantL1.add(ListConstant( |
| listTypeType, |
| substitutionsL2.map((t) { |
| // TODO(joshualitt): implement generic functions |
| if (t is FunctionType && isGenericFunction(t)) { |
| return TypeLiteralConstant(DynamicType()); |
| } else { |
| return TypeLiteralConstant(t); |
| } |
| }).toList())); |
| } |
| substitutionsConstantL0 |
| .add(ListConstant(listListTypeType, substitutionsConstantL1)); |
| } |
| translator.constants.instantiateConstant( |
| null, |
| b, |
| ListConstant(listListListTypeType, substitutionsConstantL0), |
| expectedType); |
| return expectedType; |
| } |
| |
| bool isGenericFunction(FunctionType type) => type.typeParameters.isNotEmpty; |
| |
| bool isGenericFunctionTypeParameter(TypeParameterType type) => |
| type.parameter.parent == null; |
| |
| bool _isTypeConstant(DartType type) { |
| return type is DynamicType || |
| type is VoidType || |
| type is NeverType || |
| type is NullType || |
| type is FutureOrType && _isTypeConstant(type.typeArgument) || |
| (type is FunctionType && |
| type.typeParameters.isEmpty && // TODO(joshualitt) generic functions |
| _isTypeConstant(type.returnType) && |
| type.positionalParameters.every(_isTypeConstant) && |
| type.namedParameters.every((n) => _isTypeConstant(n.type))) || |
| type is InterfaceType && type.typeArguments.every(_isTypeConstant); |
| } |
| |
| Class classForType(DartType type) { |
| if (type is DynamicType) { |
| return translator.dynamicTypeClass; |
| } else if (type is VoidType) { |
| return translator.voidTypeClass; |
| } else if (type is NeverType) { |
| // For runtime types with sound null safety, `Never?` is the same as |
| // `Null`. |
| if (type.nullability == Nullability.nullable) { |
| return translator.nullTypeClass; |
| } else { |
| return translator.neverTypeClass; |
| } |
| } else if (type is NullType) { |
| return translator.nullTypeClass; |
| } else if (type is FutureOrType) { |
| return translator.futureOrTypeClass; |
| } else if (type is InterfaceType) { |
| return translator.interfaceTypeClass; |
| } else if (type is FunctionType) { |
| if (isGenericFunction(type)) { |
| return translator.genericFunctionTypeClass; |
| } else { |
| return translator.functionTypeClass; |
| } |
| } else if (type is TypeParameterType) { |
| if (isGenericFunctionTypeParameter(type)) { |
| return translator.genericFunctionTypeParameterTypeClass; |
| } else { |
| return translator.interfaceTypeParameterTypeClass; |
| } |
| } |
| throw "Unexpected DartType: $type"; |
| } |
| |
| void _makeTypeList(CodeGenerator codeGen, List<DartType> types) { |
| w.ValueType listType = codeGen.makeListFromExpressions( |
| types.map((t) => TypeLiteral(t)).toList(), typeType); |
| translator.convertType(codeGen.function, listType, typeListExpectedType); |
| } |
| |
| void _makeInterfaceType( |
| CodeGenerator codeGen, ClassInfo info, InterfaceType type) { |
| w.Instructions b = codeGen.b; |
| ClassInfo typeInfo = translator.classInfo[type.classNode]!; |
| encodeNullability(b, type); |
| b.i64_const(typeInfo.classId); |
| _makeTypeList(codeGen, type.typeArguments); |
| } |
| |
| void _makeFutureOrType(CodeGenerator codeGen, FutureOrType type) { |
| w.Instructions b = codeGen.b; |
| w.DefinedFunction function = codeGen.function; |
| |
| // We canonicalize `FutureOr<T?>` to `FutureOr<T?>?`. However, we have to |
| // take special care to handle the case where we have |
| // undetermined nullability. To handle this, we emit the type argument, and |
| // read back its nullability at runtime. |
| if (type.nullability == Nullability.undetermined) { |
| w.ValueType typeArgumentType = makeType(codeGen, type.typeArgument); |
| w.Local typeArgumentTemporary = codeGen.addLocal(typeArgumentType); |
| b.local_tee(typeArgumentTemporary); |
| b.struct_get(typeClassInfo.struct, FieldIndex.typeIsNullable); |
| b.local_get(typeArgumentTemporary); |
| translator.convertType(function, typeArgumentType, nonNullableTypeType); |
| } else { |
| encodeNullability(b, type); |
| makeType(codeGen, type.typeArgument); |
| } |
| } |
| |
| void _makeFunctionType( |
| CodeGenerator codeGen, ClassInfo info, FunctionType type) { |
| w.Instructions b = codeGen.b; |
| encodeNullability(b, type); |
| makeType(codeGen, type.returnType); |
| if (type.positionalParameters.every(_isTypeConstant)) { |
| translator.constants.instantiateConstant( |
| codeGen.function, |
| b, |
| translator.constants.makeTypeList(type.positionalParameters), |
| typeListExpectedType); |
| } else { |
| _makeTypeList(codeGen, type.positionalParameters); |
| } |
| b.i64_const(type.requiredParameterCount); |
| if (type.namedParameters.every((n) => _isTypeConstant(n.type))) { |
| translator.constants.instantiateConstant( |
| codeGen.function, |
| b, |
| translator.constants.makeNamedParametersList(type), |
| namedParametersExpectedType); |
| } else { |
| Class namedParameterClass = translator.namedParameterClass; |
| Constructor namedParameterConstructor = |
| namedParameterClass.constructors.single; |
| List<Expression> expressions = []; |
| for (NamedType n in type.namedParameters) { |
| expressions.add(_isTypeConstant(n.type) |
| ? ConstantExpression( |
| translator.constants.makeNamedParameterConstant(n), |
| namedParameterType) |
| : ConstructorInvocation( |
| namedParameterConstructor, |
| Arguments([ |
| StringLiteral(n.name), |
| TypeLiteral(n.type), |
| BoolLiteral(n.isRequired) |
| ]))); |
| } |
| w.ValueType namedParametersListType = |
| codeGen.makeListFromExpressions(expressions, namedParameterType); |
| translator.convertType(codeGen.function, namedParametersListType, |
| namedParametersExpectedType); |
| } |
| } |
| |
| /// Makes a `_Type` object on the stack. |
| /// TODO(joshualitt): Refactor this logic to remove the dependency on |
| /// CodeGenerator. |
| w.ValueType makeType(CodeGenerator codeGen, DartType type) { |
| w.Instructions b = codeGen.b; |
| if (_isTypeConstant(type)) { |
| translator.constants.instantiateConstant( |
| codeGen.function, b, TypeLiteralConstant(type), nonNullableTypeType); |
| return nonNullableTypeType; |
| } |
| // All of the singleton types represented by canonical objects should be |
| // created const. |
| assert(type is TypeParameterType || |
| type is InterfaceType || |
| type is FutureOrType || |
| type is FunctionType); |
| if (type is TypeParameterType) { |
| return codeGen.instantiateTypeParameter(type.parameter); |
| } |
| ClassInfo info = translator.classInfo[classForType(type)]!; |
| translator.functions.allocateClass(info.classId); |
| b.i32_const(info.classId); |
| b.i32_const(initialIdentityHash); |
| if (type is InterfaceType) { |
| _makeInterfaceType(codeGen, info, type); |
| } else if (type is FutureOrType) { |
| _makeFutureOrType(codeGen, type); |
| } else if (type is FunctionType) { |
| if (isGenericFunction(type)) { |
| // TODO(joshualitt): Implement generic function types and share most of |
| // the logic with _makeFunctionType. |
| print("Not implemented: RTI ${type}"); |
| encodeNullability(b, type); |
| } else { |
| _makeFunctionType(codeGen, info, type); |
| } |
| } else { |
| throw '`$type` should have already been handled.'; |
| } |
| translator.struct_new(b, info); |
| return info.nonNullableType; |
| } |
| |
| /// Test value against a Dart type. Expects the value on the stack as a |
| /// (ref null #Top) and leaves the result on the stack as an i32. |
| /// TODO(joshualitt): Remove dependency on [CodeGenerator] |
| void emitTypeTest(CodeGenerator codeGen, DartType type, DartType operandType, |
| TreeNode node) { |
| w.Instructions b = codeGen.b; |
| if (type is! InterfaceType) { |
| // TODO(joshualitt): We can enable this after fixing `.runtimeType`. |
| // makeType(codeGen, type); |
| // codeGen.call(translator.isSubtype.reference); |
| print("Not implemented: Type test with non-interface type $type" |
| " at ${node.location}"); |
| b.drop(); |
| b.i32_const(1); |
| return; |
| } |
| bool isPotentiallyNullable = operandType.isPotentiallyNullable; |
| w.Label? resultLabel; |
| if (isPotentiallyNullable) { |
| // Store operand in a temporary variable, since Binaryen does not support |
| // block inputs. |
| w.Local operand = codeGen.addLocal(translator.topInfo.nullableType); |
| b.local_set(operand); |
| resultLabel = b.block(const [], const [w.NumType.i32]); |
| w.Label nullLabel = b.block(const [], const []); |
| b.local_get(operand); |
| b.br_on_null(nullLabel); |
| } |
| if (type.typeArguments.any((t) => t is! DynamicType)) { |
| // If the tested-against type as an instance of the static operand type |
| // has the same type arguments as the static operand type, it is not |
| // necessary to test the type arguments. |
| Class cls = translator.classForType(operandType); |
| InterfaceType? base = translator.hierarchy |
| .getTypeAsInstanceOf(type, cls, codeGen.member.enclosingLibrary) |
| ?.withDeclaredNullability(operandType.declaredNullability); |
| if (base != operandType) { |
| print("Not implemented: Type test with type arguments" |
| " at ${node.location}"); |
| } |
| } |
| List<Class> concrete = _getConcreteSubtypes(type.classNode).toList(); |
| if (type.classNode == coreTypes.functionClass) { |
| ClassInfo functionInfo = translator.classInfo[translator.functionClass]!; |
| translator.ref_test(b, functionInfo); |
| } else if (concrete.isEmpty) { |
| b.drop(); |
| b.i32_const(0); |
| } else if (concrete.length == 1) { |
| ClassInfo info = translator.classInfo[concrete.single]!; |
| b.struct_get(translator.topInfo.struct, FieldIndex.classId); |
| b.i32_const(info.classId); |
| b.i32_eq(); |
| } else { |
| w.Local idLocal = codeGen.addLocal(w.NumType.i32); |
| b.struct_get(translator.topInfo.struct, FieldIndex.classId); |
| b.local_set(idLocal); |
| w.Label done = b.block(const [], const [w.NumType.i32]); |
| b.i32_const(1); |
| for (Class cls in concrete) { |
| ClassInfo info = translator.classInfo[cls]!; |
| b.i32_const(info.classId); |
| b.local_get(idLocal); |
| b.i32_eq(); |
| b.br_if(done); |
| } |
| b.drop(); |
| b.i32_const(0); |
| b.end(); // done |
| } |
| if (isPotentiallyNullable) { |
| b.br(resultLabel!); |
| b.end(); // nullLabel |
| encodeNullability(b, type); |
| b.end(); // resultLabel |
| } |
| } |
| |
| /// Returns true if a given type is nullable, and false otherwise. This |
| /// function should not be used on [DartType]s with undetermined nullability. |
| bool isNullable(DartType type) { |
| Nullability nullability = type.nullability; |
| assert(nullability == Nullability.nullable || |
| nullability == Nullability.nonNullable); |
| return nullability == Nullability.nullable ? true : false; |
| } |
| |
| void encodeNullability(w.Instructions b, DartType type) => |
| b.i32_const(isNullable(type) ? 1 : 0); |
| } |
