Test ResolutionImpact equivalence.

pkg/compiler/lib/src/serialization/equivalence.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.
+
+/// Functions for asserting equivalence across serialization.
+
+library dart2js.serialization.equivalence;
+
+import '../common/resolution.dart';
+import '../constants/expressions.dart';
+import '../dart_types.dart';
+import '../elements/elements.dart';
+import '../elements/visitor.dart';
+import '../universe/selector.dart';
+import '../universe/use.dart';
+
+/// Equality based equivalence function.
+bool equality(a, b) => a == b;
+
+/// Returns `true` if the elements in [a] and [b] are pair-wise equivalent
+/// according to [elementEquivalence].
+bool areListsEquivalent(
+    List a,
+    List b,
+    [bool elementEquivalence(a, b) = equality]) {
+
+  if (a.length != b.length) return false;
+  for (int i = 0; i < a.length && i < b.length; i++) {
+    if (!elementEquivalence(a[i], b[i])) {
+      return false;
+    }
+  }
+  return true;
+}
+
+/// Returns `true` if the elements in [a] and [b] are equivalent as sets using
+/// [elementEquivalence] to determine element equivalence.
+bool areSetsEquivalent(
+    Iterable set1,
+    Iterable set2,
+    [bool elementEquivalence(a, b) = equality]) {
+
+  Set remaining = set2.toSet();
+  for (var element1 in set1) {
+    bool found = false;
+    for (var element2 in set2) {
+      if (elementEquivalence(element1, element2)) {
+        found = true;
+        remaining.remove(element2);
+        break;
+      }
+    }
+    if (!found) {
+      return false;
+    }
+  }
+  return remaining.isEmpty;
+}
+
+/// Returns `true` if elements [a] and [b] are equivalent.
+bool areElementsEquivalent(Element a, Element b) {
+  if (identical(a, b)) return true;
+  if (a == null || b == null) return false;
+  return const ElementIdentityEquivalence().visit(a, b);
+}
+
+/// Returns `true` if types [a] and [b] are equivalent.
+bool areTypesEquivalent(DartType a, DartType b) {
+  if (identical(a, b)) return true;
+  if (a == null || b == null) return false;
+  return const TypeEquivalence().visit(a, b);
+}
+
+/// Returns `true` if constants [a] and [b] are equivalent.
+bool areConstantsEquivalent(ConstantExpression exp1, ConstantExpression exp2) {
+  if (identical(exp1, exp2)) return true;
+  if (exp1 == null || exp2 == null) return false;
+  return const ConstantEquivalence().visit(exp1, exp2);
+}
+
+/// Returns `true` if the lists of elements, [a] and [b], are equivalent.
+bool areElementListsEquivalent(List<Element> a, List<Element> b) {
+  return areListsEquivalent(a, b, areElementsEquivalent);
+}
+
+/// Returns `true` if the lists of types, [a] and [b], are equivalent.
+bool areTypeListsEquivalent(List<DartType> a, List<DartType> b) {
+  return areListsEquivalent(a, b, areTypesEquivalent);
+}
+
+/// Returns `true` if the lists of constants, [a] and [b], are equivalent.
+bool areConstantListsEquivalent(List<ConstantExpression> a,
+                                List<ConstantExpression> b) {
+  return areListsEquivalent(a, b, areConstantsEquivalent);
+}
+
+/// Returns `true` if the selectors [a] and [b] are equivalent.
+bool areSelectorsEquivalent(Selector a, Selector b) {
+  return a.kind == b.kind &&
+         a.callStructure == b.callStructure &&
+         areNamesEquivalent(a.memberName, b.memberName);
+}
+
+/// Returns `true` if the names [a] and [b] are equivalent.
+bool areNamesEquivalent(Name a, Name b) {
+  return a.text == b.text &&
+         a.isSetter == b.isSetter &&
+         areElementsEquivalent(a.library, b.library);
+}
+
+/// Returns `true` if the dynamic uses [a] and [b] are equivalent.
+bool areDynamicUsesEquivalent(DynamicUse a, DynamicUse b) {
+  return areSelectorsEquivalent(a.selector, b.selector);
+}
+
+/// Returns `true` if the static uses [a] and [b] are equivalent.
+bool areStaticUsesEquivalent(StaticUse a, StaticUse b) {
+  return a.kind == b.kind &&
+         areElementsEquivalent(a.element, b.element);
+}
+
+/// Returns `true` if the type uses [a] and [b] are equivalent.
+bool areTypeUsesEquivalent(TypeUse a, TypeUse b) {
+  return a.kind == b.kind &&
+         areTypesEquivalent(a.type, b.type);
+}
+
+/// Returns `true` if the list literal uses [a] and [b] are equivalent.
+bool areListLiteralUsesEquivalent(ListLiteralUse a, ListLiteralUse b) {
+  return areTypesEquivalent(a.type, b.type) &&
+         a.isConstant == b.isConstant &&
+         a.isEmpty == b.isEmpty;
+}
+
+/// Returns `true` if the map literal uses [a] and [b] are equivalent.
+bool areMapLiteralUsesEquivalent(MapLiteralUse a, MapLiteralUse b) {
+  return areTypesEquivalent(a.type, b.type) &&
+         a.isConstant == b.isConstant &&
+         a.isEmpty == b.isEmpty;
+}
+
+/// Strategy for testing equivalence.
+///
+/// Use this strategy to determine equivalence without failing on inequivalence.
+class TestStrategy {
+  const TestStrategy();
+
+  bool test(var object1, var object2, String property, var value1, var value2) {
+    return value1 == value2;
+  }
+
+  bool testLists(
+      Object object1, Object object2, String property,
+      List list1, List list2,
+      [bool elementEquivalence(a, b) = equality]) {
+    return areListsEquivalent(list1, list2, elementEquivalence);
+  }
+
+  bool testSets(
+      var object1, var object2, String property,
+      Iterable set1, Iterable set2,
+      [bool elementEquivalence(a, b) = equality]) {
+    return areSetsEquivalent(set1, set2, elementEquivalence);
+  }
+
+  bool testElements(
+      Object object1, Object object2, String property,
+      Element element1, Element element2) {
+    return areElementsEquivalent(element1, element2);
+  }
+
+  bool testTypes(
+      Object object1, Object object2, String property,
+      DartType type1, DartType type2) {
+    return areTypesEquivalent(type1, type2);
+  }
+
+  bool testConstants(
+      Object object1, Object object2, String property,
+      ConstantExpression exp1, ConstantExpression exp2) {
+    return areConstantsEquivalent(exp1, exp2);
+  }
+
+  bool testTypeLists(
+      Object object1, Object object2, String property,
+      List<DartType> list1, List<DartType> list2) {
+    return areTypeListsEquivalent(list1, list2);
+  }
+
+  bool testConstantLists(
+      Object object1, Object object2, String property,
+      List<ConstantExpression> list1,
+      List<ConstantExpression> list2) {
+    return areConstantListsEquivalent(list1, list2);
+  }
+
+}
+
+/// Visitor that checks for equivalence of [Element]s.
+class ElementIdentityEquivalence extends BaseElementVisitor<bool, Element> {
+  final TestStrategy strategy;
+
+  const ElementIdentityEquivalence([this.strategy = const TestStrategy()]);
+
+  bool visit(Element element1, Element element2) {
+    if (element1 == null && element2 == null) {
+      return true;
+    } else if (element1 == null || element2 == null) {
+      return false;
+    }
+    element1 = element1.declaration;
+    element2 = element2.declaration;
+    if (element1 == element2) {
+      return true;
+    }
+    return
+        strategy.test(
+            element1, element2, 'kind',
+            element1.kind, element2.kind) &&
+        element1.accept(this, element2);
+  }
+
+  @override
+  bool visitElement(Element e, Element arg) {
+    throw new UnsupportedError("Unsupported element $e");
+  }
+
+  @override
+  bool visitLibraryElement(LibraryElement element1, LibraryElement element2) {
+    return
+        strategy.test(element1, element2,
+            'canonicalUri',
+            element1.canonicalUri, element2.canonicalUri);
+  }
+
+  @override
+  bool visitCompilationUnitElement(CompilationUnitElement element1,
+                                   CompilationUnitElement element2) {
+    return
+        strategy.test(element1, element2,
+            'name',
+            element1.name, element2.name) &&
+        visit(element1.library, element2.library);
+  }
+
+  @override
+  bool visitClassElement(ClassElement element1, ClassElement element2) {
+    return
+        strategy.test(element1, element2,
+            'name',
+            element1.name, element2.name) &&
+        visit(element1.library, element2.library);
+  }
+
+  bool checkMembers(Element element1, Element element2) {
+    if (!strategy.test(element1, element2, 'name',
+                       element1.name, element2.name)) {
+      return false;
+    }
+    if (element1.enclosingClass != null || element2.enclosingClass != null) {
+      return visit(element1.enclosingClass, element2.enclosingClass);
+    } else {
+      return visit(element1.library, element2.library);
+    }
+  }
+
+  @override
+  bool visitFieldElement(FieldElement element1, FieldElement element2) {
+    return checkMembers(element1, element2);
+  }
+
+  @override
+  bool visitConstructorElement(ConstructorElement element1,
+                               ConstructorElement element2) {
+    return checkMembers(element1, element2);
+  }
+
+  @override
+  bool visitMethodElement(MethodElement element1,
+                          MethodElement element2) {
+    return checkMembers(element1, element2);
+  }
+
+  @override
+  bool visitGetterElement(GetterElement element1,
+                          GetterElement element2) {
+    return checkMembers(element1, element2);
+  }
+
+  @override
+  bool visitSetterElement(SetterElement element1,
+                          SetterElement element2) {
+    return checkMembers(element1, element2);
+  }
+
+  @override
+  bool visitLocalFunctionElement(LocalFunctionElement element1,
+                                 LocalFunctionElement element2) {
+    // TODO(johnniwinther): Define an equivalence on locals.
+    return checkMembers(element1.memberContext, element2.memberContext);
+  }
+
+  bool visitAbstractFieldElement(AbstractFieldElement element1,
+                                 AbstractFieldElement element2) {
+    return checkMembers(element1, element2);
+  }
+
+  @override
+  bool visitTypeVariableElement(TypeVariableElement element1,
+                                TypeVariableElement element2) {
+    return
+        strategy.test(
+            element1, element2, 'name',
+            element1.name, element2.name) &&
+        visit(element1.typeDeclaration, element2.typeDeclaration);
+  }
+
+  @override
+  bool visitTypedefElement(TypedefElement element1, TypedefElement element2) {
+    return
+        strategy.test(
+            element1, element2, 'name',
+            element1.name, element2.name) &&
+        visit(element1.library, element2.library);
+  }
+
+  @override
+  bool visitParameterElement(ParameterElement element1,
+                             ParameterElement element2) {
+    return
+        strategy.test(
+            element1, element2, 'name',
+            element1.name, element2.name) &&
+        visit(element1.functionDeclaration, element2.functionDeclaration);
+  }
+
+  @override
+  bool visitImportElement(ImportElement element1, ImportElement element2) {
+    return
+        visit(element1.importedLibrary, element2.importedLibrary) &&
+        visit(element1.library, element2.library);
+  }
+
+  @override
+  bool visitExportElement(ExportElement element1, ExportElement element2) {
+    return
+        visit(element1.exportedLibrary, element2.exportedLibrary) &&
+        visit(element1.library, element2.library);
+  }
+
+  @override
+  bool visitPrefixElement(PrefixElement element1, PrefixElement element2) {
+    return
+        strategy.test(
+            element1, element2, 'name',
+            element1.name, element2.name) &&
+        visit(element1.library, element2.library);
+  }
+}
+
+
+/// Visitor that checks for equivalence of [DartType]s.
+class TypeEquivalence implements DartTypeVisitor<bool, DartType> {
+  final TestStrategy strategy;
+
+  const TypeEquivalence([this.strategy = const TestStrategy()]);
+
+  bool visit(DartType type1, DartType type2) {
+    return
+        strategy.test(type1, type2, 'kind', type1.kind, type2.kind) &&
+        type1.accept(this, type2);
+  }
+
+  @override
+  bool visitDynamicType(DynamicType type, DynamicType other) => true;
+
+  @override
+  bool visitFunctionType(FunctionType type, FunctionType other) {
+    return
+        strategy.testTypeLists(
+            type, other, 'parameterTypes',
+            type.parameterTypes, other.parameterTypes) &&
+        strategy.testTypeLists(
+            type, other, 'optionalParameterTypes',
+            type.optionalParameterTypes, other.optionalParameterTypes) &&
+        strategy.testTypeLists(
+            type, other, 'namedParameterTypes',
+            type.namedParameterTypes, other.namedParameterTypes) &&
+        strategy.testLists(
+            type, other, 'namedParameters',
+            type.namedParameters, other.namedParameters);
+  }
+
+  bool visitGenericType(GenericType type, GenericType other) {
+    return
+        strategy.testElements(
+            type, other, 'element',
+            type.element, other.element) &&
+        strategy.testTypeLists(
+            type, other, 'typeArguments',
+            type.typeArguments, other.typeArguments);
+  }
+
+  @override
+  bool visitMalformedType(MalformedType type, MalformedType other) => true;
+
+  @override
+  bool visitStatementType(StatementType type, StatementType other) {
+    throw new UnsupportedError("Unsupported type: $type");
+  }
+
+  @override
+  bool visitTypeVariableType(TypeVariableType type, TypeVariableType other) {
+    return
+        strategy.testElements(
+            type, other, 'element',
+            type.element, other.element);
+  }
+
+  @override
+  bool visitVoidType(VoidType type, VoidType argument) => true;
+
+  @override
+  bool visitInterfaceType(InterfaceType type, InterfaceType other) {
+    return visitGenericType(type, other);
+  }
+
+  @override
+  bool visitTypedefType(TypedefType type, TypedefType other) {
+    return visitGenericType(type, other);
+  }
+}
+
+/// Visitor that checks for structural equivalence of [ConstantExpression]s.
+class ConstantEquivalence
+    implements ConstantExpressionVisitor<bool, ConstantExpression> {
+  final TestStrategy strategy;
+
+  const ConstantEquivalence([this.strategy = const TestStrategy()]);
+
+  @override
+  bool visit(ConstantExpression exp1, ConstantExpression exp2) {
+    if (identical(exp1, exp2)) return true;
+    return
+        strategy.test(exp1, exp2, 'kind', exp1.kind, exp2.kind) &&
+        exp1.accept(this, exp2);
+  }
+
+  @override
+  bool visitBinary(BinaryConstantExpression exp1,
+                   BinaryConstantExpression exp2) {
+    return
+        strategy.test(exp1, exp2, 'operator', exp1.operator, exp2.operator) &&
+        strategy.testConstants(exp1, exp2, 'left', exp1.left, exp2.left) &&
+        strategy.testConstants(exp1, exp2, 'right', exp1.right, exp2.right);
+  }
+
+  @override
+  bool visitConcatenate(ConcatenateConstantExpression exp1,
+                   ConcatenateConstantExpression exp2) {
+    return
+        strategy.testConstantLists(
+            exp1, exp2, 'expressions',
+            exp1.expressions, exp2.expressions);
+  }
+
+  @override
+  bool visitConditional(ConditionalConstantExpression exp1,
+                   ConditionalConstantExpression exp2) {
+    return
+        strategy.testConstants(
+            exp1, exp2, 'condition', exp1.condition, exp2.condition) &&
+        strategy.testConstants(
+            exp1, exp2, 'trueExp', exp1.trueExp, exp2.trueExp) &&
+        strategy.testConstants(
+            exp1, exp2, 'falseExp', exp1.falseExp, exp2.falseExp);
+  }
+
+  @override
+  bool visitConstructed(ConstructedConstantExpression exp1,
+                   ConstructedConstantExpression exp2) {
+    return
+        strategy.testTypes(
+            exp1, exp2, 'type',
+            exp1.type, exp2.type) &&
+        strategy.testElements(
+            exp1, exp2, 'target',
+            exp1.target, exp2.target) &&
+        strategy.testConstantLists(
+            exp1, exp2, 'arguments',
+            exp1.arguments, exp2.arguments) &&
+        strategy.test(exp1, exp2, 'callStructure',
+             exp1.callStructure, exp2.callStructure);
+  }
+
+  @override
+  bool visitFunction(FunctionConstantExpression exp1,
+                FunctionConstantExpression exp2) {
+    return
+        strategy.testElements(
+            exp1, exp2, 'element',
+            exp1.element, exp2.element);
+  }
+
+  @override
+  bool visitIdentical(IdenticalConstantExpression exp1,
+                 IdenticalConstantExpression exp2) {
+    return
+        strategy.testConstants(exp1, exp2, 'left', exp1.left, exp2.left) &&
+        strategy.testConstants(exp1, exp2, 'right', exp1.right, exp2.right);
+  }
+
+  @override
+  bool visitList(ListConstantExpression exp1, ListConstantExpression exp2) {
+    return
+        strategy.testTypes(
+            exp1, exp2, 'type',
+            exp1.type, exp2.type) &&
+        strategy.testConstantLists(
+            exp1, exp2, 'values',
+            exp1.values, exp2.values);
+  }
+
+  @override
+  bool visitMap(MapConstantExpression exp1, MapConstantExpression exp2) {
+    return
+        strategy.testTypes(
+            exp1, exp2, 'type',
+            exp1.type, exp2.type) &&
+        strategy.testConstantLists(
+            exp1, exp2, 'keys',
+            exp1.keys, exp2.keys) &&
+        strategy.testConstantLists(
+            exp1, exp2, 'values',
+            exp1.values, exp2.values);
+  }
+
+  @override
+  bool visitNamed(NamedArgumentReference exp1, NamedArgumentReference exp2) {
+    return strategy.test(exp1, exp2, 'name', exp1.name, exp2.name);
+  }
+
+  @override
+  bool visitPositional(PositionalArgumentReference exp1,
+                  PositionalArgumentReference exp2) {
+    return strategy.test(exp1, exp2, 'index', exp1.index, exp2.index);
+  }
+
+  @override
+  bool visitSymbol(SymbolConstantExpression exp1,
+                   SymbolConstantExpression exp2) {
+    // TODO: implement visitSymbol
+    return true;
+  }
+
+  @override
+  bool visitType(TypeConstantExpression exp1, TypeConstantExpression exp2) {
+    return strategy.testTypes(exp1, exp2, 'type', exp1.type, exp2.type);
+  }
+
+  @override
+  bool visitUnary(UnaryConstantExpression exp1, UnaryConstantExpression exp2) {
+    return
+        strategy.test(exp1, exp2, 'operator', exp1.operator, exp2.operator) &&
+        strategy.testConstants(
+            exp1, exp2, 'expression', exp1.expression, exp2.expression);
+  }
+
+  @override
+  bool visitVariable(VariableConstantExpression exp1,
+                VariableConstantExpression exp2) {
+    return
+        strategy.testElements(
+            exp1, exp2, 'element',
+            exp1.element, exp2.element);
+  }
+
+  @override
+  bool visitBool(BoolConstantExpression exp1, BoolConstantExpression exp2) {
+    return
+        strategy.test(
+            exp1, exp2, 'primitiveValue',
+            exp1.primitiveValue, exp2.primitiveValue);
+  }
+
+  @override
+  bool visitDouble(DoubleConstantExpression exp1,
+                   DoubleConstantExpression exp2) {
+    return
+        strategy.test(
+            exp1, exp2, 'primitiveValue',
+            exp1.primitiveValue, exp2.primitiveValue);
+  }
+
+  @override
+  bool visitInt(IntConstantExpression exp1, IntConstantExpression exp2) {
+    return
+        strategy.test(
+            exp1, exp2, 'primitiveValue',
+            exp1.primitiveValue, exp2.primitiveValue);
+  }
+
+  @override
+  bool visitNull(NullConstantExpression exp1, NullConstantExpression exp2) {
+    return true;
+  }
+
+  @override
+  bool visitString(StringConstantExpression exp1,
+                   StringConstantExpression exp2) {
+    return
+        strategy.test(
+            exp1, exp2, 'primitiveValue',
+            exp1.primitiveValue, exp2.primitiveValue);
+  }
+
+  @override
+  bool visitBoolFromEnvironment(BoolFromEnvironmentConstantExpression exp1,
+                                BoolFromEnvironmentConstantExpression exp2) {
+    return
+        strategy.testConstants(exp1, exp2, 'name', exp1.name, exp2.name) &&
+        strategy.testConstants(
+            exp1, exp2, 'defaultValue',
+            exp1.defaultValue, exp2.defaultValue);
+  }
+
+  @override
+  bool visitIntFromEnvironment(IntFromEnvironmentConstantExpression exp1,
+                               IntFromEnvironmentConstantExpression exp2) {
+    return
+        strategy.testConstants(exp1, exp2, 'name', exp1.name, exp2.name) &&
+        strategy.testConstants(
+            exp1, exp2, 'defaultValue',
+            exp1.defaultValue, exp2.defaultValue);
+  }
+
+  @override
+  bool visitStringFromEnvironment(
+      StringFromEnvironmentConstantExpression exp1,
+      StringFromEnvironmentConstantExpression exp2) {
+    return
+        strategy.testConstants(exp1, exp2, 'name', exp1.name, exp2.name) &&
+        strategy.testConstants(
+            exp1, exp2, 'defaultValue',
+            exp1.defaultValue, exp2.defaultValue);
+  }
+
+  @override
+  bool visitStringLength(StringLengthConstantExpression exp1,
+                    StringLengthConstantExpression exp2) {
+    return
+        strategy.testConstants(
+            exp1, exp2, 'expression',
+            exp1.expression, exp2.expression);
+  }
+
+  @override
+  bool visitDeferred(DeferredConstantExpression exp1,
+                DeferredConstantExpression exp2) {
+    // TODO: implement visitDeferred
+    return true;
+  }
+}
+
+/// Tests the equivalence of [impact1] and [impact2] using [strategy].
+bool testResolutionImpactEquivalence(
+    ResolutionImpact impact1,
+    ResolutionImpact impact2,
+    [TestStrategy strategy = const TestStrategy()]) {
+  return
+      strategy.testSets(
+          impact1, impact2, 'constSymbolNames',
+          impact1.constSymbolNames, impact2.constSymbolNames) &&
+      strategy.testSets(
+          impact1, impact2, 'constantLiterals',
+          impact1.constantLiterals, impact2.constantLiterals,
+          areConstantsEquivalent) &&
+      strategy.testSets(
+          impact1, impact2, 'dynamicUses',
+          impact1.dynamicUses, impact2.dynamicUses,
+          areDynamicUsesEquivalent) &&
+      strategy.testSets(
+          impact1, impact2, 'features',
+          impact1.features, impact2.features) &&
+      strategy.testSets(
+          impact1, impact2, 'listLiterals',
+          impact1.listLiterals, impact2.listLiterals,
+          areListLiteralUsesEquivalent) &&
+      strategy.testSets(
+          impact1, impact2, 'mapLiterals',
+          impact1.mapLiterals, impact2.mapLiterals,
+          areMapLiteralUsesEquivalent) &&
+      strategy.testSets(
+          impact1, impact2, 'staticUses',
+          impact1.staticUses, impact2.staticUses,
+          areStaticUsesEquivalent) &&
+      strategy.testSets(
+          impact1, impact2, 'typeUses',
+          impact1.typeUses, impact2.typeUses,
+          areTypeUsesEquivalent);
+}