Aske Simon Christensen
219a2fcf66
Unevaluated constants are re-evaluated, and evaluated constants are re-canonicalized. Change-Id: I241f6b5d734797101ab1168746a849713c104695 Reviewed-on: https://dart-review.googlesource.com/c/91230 Commit-Queue: Aske Simon Christensen <askesc@google.com> Reviewed-by: Kevin Millikin <kmillikin@google.com>
1689 lines
56 KiB
Dart
1689 lines
56 KiB
Dart
// Copyright (c) 2017, the Dart project authors. Please see the AUTHORS file
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// for details. All rights reserved. Use of this source code is governed by a
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// BSD-style license that can be found in the LICENSE file.
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/// This library implements a kernel2kernel constant evaluation transformation.
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///
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/// Even though it is expected that the frontend does not emit kernel AST which
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/// contains compile-time errors, this transformation still performs some
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/// valiation and throws a [ConstantEvaluationError] if there was a compile-time
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/// errors.
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///
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/// Due to the lack information which is is only available in the front-end,
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/// this validation is incomplete (e.g. whether an integer literal used the
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/// hexadecimal syntax or not).
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///
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/// Furthermore due to the lowering of certain constructs in the front-end
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/// (e.g. '??') we need to support a super-set of the normal constant expression
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/// language. Issue(http://dartbug.com/31799)
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library kernel.transformations.constants;
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import 'dart:io' as io;
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import '../ast.dart';
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import '../class_hierarchy.dart';
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import '../core_types.dart';
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import '../external_name.dart' show getExternalName;
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import '../kernel.dart';
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import '../type_algebra.dart';
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import '../type_environment.dart';
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Component transformComponent(
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Component component, ConstantsBackend backend, ErrorReporter errorReporter,
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{bool keepFields: false,
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bool legacyMode: false,
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bool enableAsserts: false,
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bool evaluateAnnotations: true,
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CoreTypes coreTypes,
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ClassHierarchy hierarchy}) {
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coreTypes ??= new CoreTypes(component);
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hierarchy ??= new ClassHierarchy(component);
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final typeEnvironment =
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new TypeEnvironment(coreTypes, hierarchy, legacyMode: legacyMode);
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transformLibraries(
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component.libraries, backend, coreTypes, typeEnvironment, errorReporter,
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keepFields: keepFields,
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enableAsserts: enableAsserts,
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evaluateAnnotations: evaluateAnnotations);
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return component;
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}
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void transformLibraries(
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List<Library> libraries,
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ConstantsBackend backend,
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CoreTypes coreTypes,
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TypeEnvironment typeEnvironment,
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ErrorReporter errorReporter,
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{bool keepFields: false,
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bool keepVariables: false,
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bool evaluateAnnotations: true,
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bool enableAsserts: false}) {
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final ConstantsTransformer constantsTransformer = new ConstantsTransformer(
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backend,
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keepFields,
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keepVariables,
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evaluateAnnotations,
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coreTypes,
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typeEnvironment,
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enableAsserts,
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errorReporter);
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for (final Library library in libraries) {
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constantsTransformer.convertLibrary(library);
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}
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}
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class ConstantsTransformer extends Transformer {
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final ConstantEvaluator constantEvaluator;
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final CoreTypes coreTypes;
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final TypeEnvironment typeEnvironment;
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/// Whether to preserve constant [Field]s. All use-sites will be rewritten.
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final bool keepFields;
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final bool keepVariables;
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final bool evaluateAnnotations;
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ConstantsTransformer(
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ConstantsBackend backend,
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this.keepFields,
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this.keepVariables,
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this.evaluateAnnotations,
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this.coreTypes,
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this.typeEnvironment,
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bool enableAsserts,
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ErrorReporter errorReporter)
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: constantEvaluator = new ConstantEvaluator(
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backend, typeEnvironment, coreTypes, enableAsserts, errorReporter);
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// Transform the library/class members:
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void convertLibrary(Library library) {
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transformAnnotations(library.annotations, library);
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transformList(library.dependencies, this, library);
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transformList(library.parts, this, library);
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transformList(library.typedefs, this, library);
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transformList(library.classes, this, library);
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transformList(library.procedures, this, library);
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transformList(library.fields, this, library);
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if (!keepFields) {
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// The transformer API does not iterate over `Library.additionalExports`,
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// so we manually delete the references to shaken nodes.
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library.additionalExports.removeWhere((Reference reference) {
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return reference.canonicalName == null;
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});
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}
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}
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visitLibraryPart(LibraryPart node) {
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constantEvaluator.withNewEnvironment(() {
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transformAnnotations(node.annotations, node);
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});
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return node;
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}
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visitLibraryDependency(LibraryDependency node) {
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constantEvaluator.withNewEnvironment(() {
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transformAnnotations(node.annotations, node);
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});
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return node;
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}
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visitClass(Class node) {
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constantEvaluator.withNewEnvironment(() {
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transformAnnotations(node.annotations, node);
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transformList(node.fields, this, node);
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transformList(node.typeParameters, this, node);
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transformList(node.constructors, this, node);
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transformList(node.procedures, this, node);
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transformList(node.redirectingFactoryConstructors, this, node);
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});
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return node;
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}
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visitProcedure(Procedure node) {
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constantEvaluator.withNewEnvironment(() {
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transformAnnotations(node.annotations, node);
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node.function = node.function.accept(this)..parent = node;
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});
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return node;
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}
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visitConstructor(Constructor node) {
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constantEvaluator.withNewEnvironment(() {
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transformAnnotations(node.annotations, node);
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transformList(node.initializers, this, node);
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node.function = node.function.accept(this)..parent = node;
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});
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return node;
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}
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visitTypedef(Typedef node) {
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constantEvaluator.withNewEnvironment(() {
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transformAnnotations(node.annotations, node);
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transformList(node.typeParameters, this, node);
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transformList(node.typeParametersOfFunctionType, this, node);
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transformList(node.positionalParameters, this, node);
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transformList(node.namedParameters, this, node);
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});
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return node;
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}
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visitRedirectingFactoryConstructor(RedirectingFactoryConstructor node) {
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constantEvaluator.withNewEnvironment(() {
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transformAnnotations(node.annotations, node);
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transformList(node.typeParameters, this, node);
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transformList(node.positionalParameters, this, node);
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transformList(node.namedParameters, this, node);
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});
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return node;
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}
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visitTypeParameter(TypeParameter node) {
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transformAnnotations(node.annotations, node);
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return node;
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}
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void transformAnnotations(List<Expression> nodes, TreeNode parent) {
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if (evaluateAnnotations && nodes.length > 0) {
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transformExpressions(nodes, parent);
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}
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}
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void transformExpressions(List<Expression> nodes, TreeNode parent) {
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constantEvaluator.withNewEnvironment(() {
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for (int i = 0; i < nodes.length; ++i) {
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nodes[i] = tryEvaluateAndTransformWithContext(parent, nodes[i])
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..parent = parent;
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}
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});
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}
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// Handle definition of constants:
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visitFunctionNode(FunctionNode node) {
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final positionalParameterCount = node.positionalParameters.length;
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for (int i = node.requiredParameterCount;
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i < positionalParameterCount;
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++i) {
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final VariableDeclaration variable = node.positionalParameters[i];
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transformAnnotations(variable.annotations, variable);
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if (variable.initializer != null) {
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variable.initializer =
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tryEvaluateAndTransformWithContext(variable, variable.initializer)
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..parent = node;
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}
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}
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for (final VariableDeclaration variable in node.namedParameters) {
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transformAnnotations(variable.annotations, variable);
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if (variable.initializer != null) {
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variable.initializer =
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tryEvaluateAndTransformWithContext(variable, variable.initializer)
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..parent = node;
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}
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}
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if (node.body != null) {
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node.body = node.body.accept(this)..parent = node;
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}
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return node;
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}
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visitVariableDeclaration(VariableDeclaration node) {
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transformAnnotations(node.annotations, node);
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if (node.initializer != null) {
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if (node.isConst) {
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final Constant constant =
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tryEvaluateWithContext(node, node.initializer);
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// If there was a constant evaluation error we will not continue and
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// simply keep the old [node].
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if (constant != null) {
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constantEvaluator.env.addVariableValue(node, constant);
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if (keepVariables) {
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// So the value of the variable is still available for debugging
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// purposes we convert the constant variable to be a final variable
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// initialized to the evaluated constant expression.
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node.initializer = new ConstantExpression(constant)..parent = node;
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node.isFinal = true;
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node.isConst = false;
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} else {
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// Since we convert all use-sites of constants, the constant
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// [VariableDeclaration] is unused and we'll therefore remove it.
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return null;
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}
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}
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} else {
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node.initializer = node.initializer.accept(this)..parent = node;
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}
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}
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return node;
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}
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visitField(Field node) {
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return constantEvaluator.withNewEnvironment(() {
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if (node.isConst) {
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// Since we convert all use-sites of constants, the constant [Field]
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// cannot be referenced anymore. We therefore get rid of it if
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// [keepFields] was not specified.
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if (!keepFields) {
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return null;
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}
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// Otherwise we keep the constant [Field] and convert it's initializer.
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transformAnnotations(node.annotations, node);
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if (node.initializer != null) {
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node.initializer =
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tryEvaluateAndTransformWithContext(node, node.initializer)
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..parent = node;
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}
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} else {
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transformAnnotations(node.annotations, node);
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if (node.initializer != null) {
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node.initializer = node.initializer.accept(this)..parent = node;
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}
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}
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return node;
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});
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}
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// Handle use-sites of constants (and "inline" constant expressions):
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visitSymbolLiteral(SymbolLiteral node) {
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return new ConstantExpression(constantEvaluator.evaluate(node));
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}
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visitStaticGet(StaticGet node) {
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final Member target = node.target;
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if (target is Field && target.isConst) {
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final Constant constant =
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tryEvaluateWithContext(node, target.initializer);
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return constant != null ? new ConstantExpression(constant) : node;
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} else if (target is Procedure && target.kind == ProcedureKind.Method) {
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return tryEvaluateAndTransformWithContext(node, node);
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}
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return super.visitStaticGet(node);
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}
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visitSwitchCase(SwitchCase node) {
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transformExpressions(node.expressions, node);
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return super.visitSwitchCase(node);
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}
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visitVariableGet(VariableGet node) {
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if (node.variable.isConst) {
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return tryEvaluateAndTransformWithContext(node, node);
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}
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return super.visitVariableGet(node);
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}
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visitListLiteral(ListLiteral node) {
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if (node.isConst) {
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return tryEvaluateAndTransformWithContext(node, node);
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}
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return super.visitListLiteral(node);
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}
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visitMapLiteral(MapLiteral node) {
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if (node.isConst) {
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return tryEvaluateAndTransformWithContext(node, node);
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}
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return super.visitMapLiteral(node);
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}
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visitConstructorInvocation(ConstructorInvocation node) {
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if (node.isConst) {
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return tryEvaluateAndTransformWithContext(node, node);
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}
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return super.visitConstructorInvocation(node);
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}
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visitStaticInvocation(StaticInvocation node) {
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if (node.isConst) {
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return tryEvaluateAndTransformWithContext(node, node);
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}
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return super.visitStaticInvocation(node);
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}
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visitConstantExpression(ConstantExpression node) {
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Constant constant = node.constant;
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if (constant is UnevaluatedConstant) {
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Expression expression = constant.expression;
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return tryEvaluateAndTransformWithContext(expression, expression);
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} else {
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node.constant = constantEvaluator.canonicalize(constant);
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return node;
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}
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}
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tryEvaluateAndTransformWithContext(TreeNode treeContext, Expression node) {
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final Constant constant = tryEvaluateWithContext(treeContext, node);
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return constant != null ? new ConstantExpression(constant) : node;
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}
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tryEvaluateWithContext(TreeNode treeContext, Expression node) {
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if (treeContext == node) {
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return constantEvaluator.evaluate(node);
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}
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return constantEvaluator.runInsideContext(treeContext, () {
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return constantEvaluator.evaluate(node);
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});
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}
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}
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class ConstantEvaluator extends RecursiveVisitor {
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final ConstantsBackend backend;
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final CoreTypes coreTypes;
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final TypeEnvironment typeEnvironment;
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final bool enableAsserts;
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final ErrorReporter errorReporter;
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final isInstantiated = new IsInstantiatedVisitor().isInstantiated;
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final Map<Constant, Constant> canonicalizationCache;
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final Map<Node, Object> nodeCache;
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final NullConstant nullConstant = new NullConstant();
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final BoolConstant trueConstant = new BoolConstant(true);
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final BoolConstant falseConstant = new BoolConstant(false);
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final List<TreeNode> contextChain = [];
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InstanceBuilder instanceBuilder;
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EvaluationEnvironment env;
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ConstantEvaluator(this.backend, this.typeEnvironment, this.coreTypes,
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this.enableAsserts, this.errorReporter)
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: canonicalizationCache = <Constant, Constant>{},
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nodeCache = <Node, Constant>{};
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/// Evaluates [node] and possibly cache the evaluation result.
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Constant evaluate(Expression node) {
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try {
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return _evaluateSubexpression(node);
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} on _AbortCurrentEvaluation catch (e) {
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return new UnevaluatedConstant(new InvalidExpression(e.message));
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}
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}
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/// Evaluates [node] and possibly cache the evaluation result.
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/// @throws _AbortCurrentEvaluation if expression can't be evaluated.
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Constant _evaluateSubexpression(Expression node) {
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if (node == null) return nullConstant;
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if (env.isEmpty) {
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// We only try to evaluate the same [node] *once* within an empty
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// environment.
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if (nodeCache.containsKey(node)) {
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final Constant constant = nodeCache[node];
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if (constant == null)
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throw new _AbortCurrentEvaluation(
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errorReporter.circularity(contextChain, node));
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return constant;
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}
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nodeCache[node] = null;
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return nodeCache[node] = node.accept(this);
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}
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return node.accept(this);
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}
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Constant runInsideContext(TreeNode node, Constant fun()) {
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try {
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pushContext(node);
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return fun();
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} finally {
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popContext(node);
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}
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}
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Constant runInsideContextIfNoContext(TreeNode node, Constant fun()) {
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if (contextChain.isEmpty) {
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return runInsideContext(node, fun);
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} else {
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return fun();
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}
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}
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pushContext(TreeNode contextNode) {
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contextChain.add(contextNode);
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}
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popContext(TreeNode contextNode) {
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assert(contextChain.last == contextNode);
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contextChain.length = contextChain.length - 1;
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}
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defaultTreeNode(Node node) {
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// Only a subset of the expression language is valid for constant
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// evaluation.
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throw 'Constant evaluation has no support for ${node.runtimeType} yet!';
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}
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visitNullLiteral(NullLiteral node) => nullConstant;
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visitBoolLiteral(BoolLiteral node) {
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return node.value ? trueConstant : falseConstant;
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}
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visitIntLiteral(IntLiteral node) {
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// The frontend will ensure the integer literals are in signed 64-bit
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// range.
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return canonicalize(new IntConstant(node.value));
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}
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visitDoubleLiteral(DoubleLiteral node) {
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return canonicalize(new DoubleConstant(node.value));
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}
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visitStringLiteral(StringLiteral node) {
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return canonicalize(new StringConstant(node.value));
|
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}
|
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visitTypeLiteral(TypeLiteral node) {
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final DartType type = evaluateDartType(node, node.type);
|
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return canonicalize(new TypeLiteralConstant(type));
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}
|
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visitConstantExpression(ConstantExpression node) {
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// If there were already constants in the AST then we make sure we
|
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// re-canonicalize them. After running the transformer we will therefore
|
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// have a fully-canonicalized constant DAG with roots coming from the
|
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// [ConstantExpression] nodes in the AST.
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return canonicalize(node.constant);
|
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}
|
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|
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visitListLiteral(ListLiteral node) {
|
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if (!node.isConst) {
|
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throw new _AbortCurrentEvaluation(
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errorReporter.nonConstLiteral(contextChain, node, 'List'));
|
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}
|
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final List<Constant> entries = new List<Constant>(node.expressions.length);
|
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for (int i = 0; i < node.expressions.length; ++i) {
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entries[i] = node.expressions[i].accept(this);
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}
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final DartType typeArgument = evaluateDartType(node, node.typeArgument);
|
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final ListConstant listConstant = new ListConstant(typeArgument, entries);
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return canonicalize(backend.lowerListConstant(listConstant));
|
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}
|
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|
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visitMapLiteral(MapLiteral node) {
|
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if (!node.isConst) {
|
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throw new _AbortCurrentEvaluation(
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errorReporter.nonConstLiteral(contextChain, node, 'Map'));
|
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}
|
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final Set<Constant> usedKeys = new Set<Constant>();
|
||
final List<ConstantMapEntry> entries =
|
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new List<ConstantMapEntry>(node.entries.length);
|
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for (int i = 0; i < node.entries.length; ++i) {
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final key = node.entries[i].key.accept(this);
|
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final value = node.entries[i].value.accept(this);
|
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if (!usedKeys.add(key)) {
|
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// TODO(kustermann): We should change the context handling from just
|
||
// capturing the `TreeNode`s to a `(TreeNode, String message)` tuple and
|
||
// report where the first key with the same value was.
|
||
throw new _AbortCurrentEvaluation(
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errorReporter.duplicateKey(contextChain, node.entries[i], key));
|
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}
|
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entries[i] = new ConstantMapEntry(key, value);
|
||
}
|
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final DartType keyType = evaluateDartType(node, node.keyType);
|
||
final DartType valueType = evaluateDartType(node, node.valueType);
|
||
final MapConstant mapConstant =
|
||
new MapConstant(keyType, valueType, entries);
|
||
return canonicalize(backend.lowerMapConstant(mapConstant));
|
||
}
|
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|
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visitFunctionExpression(FunctionExpression node) {
|
||
throw new _AbortCurrentEvaluation(
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errorReporter.nonConstLiteral(contextChain, node, 'Function'));
|
||
}
|
||
|
||
visitConstructorInvocation(ConstructorInvocation node) {
|
||
final Constructor constructor = node.target;
|
||
final Class klass = constructor.enclosingClass;
|
||
if (!constructor.isConst) {
|
||
throw 'The front-end should ensure we do not encounter a '
|
||
'constructor invocation of a non-const constructor.';
|
||
}
|
||
if (constructor.function.body != null &&
|
||
constructor.function.body is! EmptyStatement) {
|
||
throw 'Constructor "$node" has non-trivial body "${constructor.function.body.runtimeType}".';
|
||
}
|
||
if (klass.isAbstract) {
|
||
throw 'Constructor "$node" belongs to abstract class "${klass}".';
|
||
}
|
||
|
||
final typeArguments = evaluateTypeArguments(node, node.arguments);
|
||
final positionals = evaluatePositionalArguments(node.arguments);
|
||
final named = evaluateNamedArguments(node.arguments);
|
||
|
||
// Fill in any missing type arguments with "dynamic".
|
||
for (int i = typeArguments.length; i < klass.typeParameters.length; i++) {
|
||
typeArguments.add(const DynamicType());
|
||
}
|
||
|
||
// Start building a new instance.
|
||
return withNewInstanceBuilder(klass, typeArguments, () {
|
||
return runInsideContextIfNoContext(node, () {
|
||
// "Run" the constructor (and any super constructor calls), which will
|
||
// initialize the fields of the new instance.
|
||
handleConstructorInvocation(
|
||
constructor, typeArguments, positionals, named);
|
||
final InstanceConstant result = instanceBuilder.buildInstance();
|
||
|
||
// Special case the dart:core's Symbol class here and convert it to a
|
||
// [SymbolConstant]. For invalid values we report a compile-time error.
|
||
if (result.classNode == coreTypes.internalSymbolClass) {
|
||
// The dart:_internal's Symbol class has only the name field.
|
||
assert(coreTypes.internalSymbolClass.fields
|
||
.where((f) => !f.isStatic)
|
||
.length ==
|
||
1);
|
||
final nameValue = result.fieldValues.values.single;
|
||
|
||
if (nameValue is StringConstant &&
|
||
isValidSymbolName(nameValue.value)) {
|
||
return canonicalize(new SymbolConstant(nameValue.value, null));
|
||
}
|
||
throw new _AbortCurrentEvaluation(errorReporter.invalidSymbolName(
|
||
contextChain, node.arguments.positional.first, nameValue));
|
||
}
|
||
|
||
return canonicalize(result);
|
||
});
|
||
});
|
||
}
|
||
|
||
bool isValidSymbolName(String name) {
|
||
// See https://api.dartlang.org/stable/2.0.0/dart-core/Symbol/Symbol.html:
|
||
//
|
||
// A qualified name is a valid name preceded by a public identifier name and
|
||
// a '.', e.g., foo.bar.baz= is a qualified version of baz=.
|
||
//
|
||
// That means that the content of the name String must be either
|
||
// - a valid public Dart identifier (that is, an identifier not
|
||
// starting with "_"),
|
||
// - such an identifier followed by "=" (a setter name),
|
||
// - the name of a declarable operator,
|
||
// - any of the above preceded by any number of qualifiers, where a
|
||
// qualifier is a non-private identifier followed by '.',
|
||
// - or the empty string (the default name of a library with no library
|
||
// name declaration).
|
||
|
||
const operatorNames = const <String>[
|
||
'+',
|
||
'-',
|
||
'*',
|
||
'/',
|
||
'%',
|
||
'~/',
|
||
'&',
|
||
'|',
|
||
'^',
|
||
'~',
|
||
'<<',
|
||
'>>',
|
||
'<',
|
||
'<=',
|
||
'>',
|
||
'>=',
|
||
'==',
|
||
'[]',
|
||
'[]=',
|
||
'unary-'
|
||
];
|
||
|
||
if (name == null) return false;
|
||
if (name == '') return true;
|
||
|
||
final parts = name.split('.');
|
||
|
||
// Each qualifier must be a public identifier.
|
||
for (int i = 0; i < parts.length - 1; ++i) {
|
||
if (!isValidPublicIdentifier(parts[i])) return false;
|
||
}
|
||
|
||
String last = parts.last;
|
||
if (operatorNames.contains(last)) {
|
||
return true;
|
||
}
|
||
if (last.endsWith('=')) {
|
||
last = last.substring(0, last.length - 1);
|
||
}
|
||
if (!isValidPublicIdentifier(last)) return false;
|
||
|
||
return true;
|
||
}
|
||
|
||
/// From the Dart Language specification:
|
||
///
|
||
/// IDENTIFIER:
|
||
/// IDENTIFIER_START IDENTIFIER_PART*
|
||
///
|
||
/// IDENTIFIER_START:
|
||
/// IDENTIFIER_START_NO_DOLLAR | ‘$’
|
||
///
|
||
/// IDENTIFIER_PART:
|
||
/// IDENTIFIER_START | DIGIT
|
||
///
|
||
/// IDENTIFIER_NO_DOLLAR:
|
||
/// IDENTIFIER_START_NO_DOLLAR IDENTIFIER_PART_NO_DOLLAR*
|
||
///
|
||
/// IDENTIFIER_START_NO_DOLLAR:
|
||
/// LETTER | '_'
|
||
///
|
||
/// IDENTIFIER_PART_NO_DOLLAR:
|
||
/// IDENTIFIER_START_NO_DOLLAR | DIGIT
|
||
///
|
||
static final publicIdentifierRegExp =
|
||
new RegExp(r'^[a-zA-Z$][a-zA-Z0-9_$]*$');
|
||
|
||
static const nonUsableKeywords = const <String>[
|
||
'assert',
|
||
'break',
|
||
'case',
|
||
'catch',
|
||
'class',
|
||
'const',
|
||
'continue',
|
||
'default',
|
||
'do',
|
||
'else',
|
||
'enum',
|
||
'extends',
|
||
'false',
|
||
'final',
|
||
'finally',
|
||
'for',
|
||
'if',
|
||
'in',
|
||
'is',
|
||
'new',
|
||
'null',
|
||
'rethrow',
|
||
'return',
|
||
'super',
|
||
'switch',
|
||
'this',
|
||
'throw',
|
||
'true',
|
||
'try',
|
||
'var',
|
||
'while',
|
||
'with',
|
||
];
|
||
|
||
bool isValidPublicIdentifier(String name) {
|
||
return publicIdentifierRegExp.hasMatch(name) &&
|
||
!nonUsableKeywords.contains(name);
|
||
}
|
||
|
||
handleConstructorInvocation(
|
||
Constructor constructor,
|
||
List<DartType> typeArguments,
|
||
List<Constant> positionalArguments,
|
||
Map<String, Constant> namedArguments) {
|
||
return runInsideContext(constructor, () {
|
||
return withNewEnvironment(() {
|
||
final Class klass = constructor.enclosingClass;
|
||
final FunctionNode function = constructor.function;
|
||
|
||
// We simulate now the constructor invocation.
|
||
|
||
// Step 1) Map type arguments and normal arguments from caller to callee.
|
||
for (int i = 0; i < klass.typeParameters.length; i++) {
|
||
env.addTypeParameterValue(klass.typeParameters[i], typeArguments[i]);
|
||
}
|
||
for (int i = 0; i < function.positionalParameters.length; i++) {
|
||
final VariableDeclaration parameter =
|
||
function.positionalParameters[i];
|
||
final Constant value = (i < positionalArguments.length)
|
||
? positionalArguments[i]
|
||
: _evaluateSubexpression(parameter.initializer);
|
||
env.addVariableValue(parameter, value);
|
||
}
|
||
for (final VariableDeclaration parameter in function.namedParameters) {
|
||
final Constant value = namedArguments[parameter.name] ??
|
||
_evaluateSubexpression(parameter.initializer);
|
||
env.addVariableValue(parameter, value);
|
||
}
|
||
|
||
// Step 2) Run all initializers (including super calls) with environment setup.
|
||
for (final Field field in klass.fields) {
|
||
if (!field.isStatic) {
|
||
instanceBuilder.setFieldValue(
|
||
field, _evaluateSubexpression(field.initializer));
|
||
}
|
||
}
|
||
for (final Initializer init in constructor.initializers) {
|
||
if (init is FieldInitializer) {
|
||
instanceBuilder.setFieldValue(
|
||
init.field, _evaluateSubexpression(init.value));
|
||
} else if (init is LocalInitializer) {
|
||
final VariableDeclaration variable = init.variable;
|
||
env.addVariableValue(
|
||
variable, _evaluateSubexpression(variable.initializer));
|
||
} else if (init is SuperInitializer) {
|
||
handleConstructorInvocation(
|
||
init.target,
|
||
evaluateSuperTypeArguments(
|
||
init, constructor.enclosingClass.supertype),
|
||
evaluatePositionalArguments(init.arguments),
|
||
evaluateNamedArguments(init.arguments));
|
||
} else if (init is RedirectingInitializer) {
|
||
// Since a redirecting constructor targets a constructor of the same
|
||
// class, we pass the same [typeArguments].
|
||
handleConstructorInvocation(
|
||
init.target,
|
||
typeArguments,
|
||
evaluatePositionalArguments(init.arguments),
|
||
evaluateNamedArguments(init.arguments));
|
||
} else if (init is AssertInitializer) {
|
||
if (enableAsserts) {
|
||
final Constant condition = init.statement.condition.accept(this);
|
||
|
||
if (condition is BoolConstant) {
|
||
if (!condition.value) {
|
||
final Constant message = init.statement.message?.accept(this);
|
||
if (message == null) {
|
||
throw new _AbortCurrentEvaluation(
|
||
errorReporter.failedAssertion(
|
||
contextChain, init.statement.condition, null));
|
||
} else if (message is StringConstant) {
|
||
throw new _AbortCurrentEvaluation(
|
||
errorReporter.failedAssertion(contextChain,
|
||
init.statement.condition, message.value));
|
||
}
|
||
throw new _AbortCurrentEvaluation(
|
||
errorReporter.invalidDartType(
|
||
contextChain,
|
||
init.statement.message,
|
||
message,
|
||
typeEnvironment.stringType));
|
||
}
|
||
} else {
|
||
throw new _AbortCurrentEvaluation(errorReporter.invalidDartType(
|
||
contextChain,
|
||
init.statement.condition,
|
||
condition,
|
||
typeEnvironment.boolType));
|
||
}
|
||
}
|
||
} else {
|
||
throw new Exception(
|
||
'No support for handling initializer of type "${init.runtimeType}".');
|
||
}
|
||
}
|
||
});
|
||
});
|
||
}
|
||
|
||
visitInvalidExpression(InvalidExpression node) {
|
||
throw new _AbortCurrentEvaluation(node.message);
|
||
}
|
||
|
||
visitMethodInvocation(MethodInvocation node) {
|
||
// We have no support for generic method invocation atm.
|
||
assert(node.arguments.named.isEmpty);
|
||
|
||
final Constant receiver = _evaluateSubexpression(node.receiver);
|
||
final List<Constant> arguments =
|
||
evaluatePositionalArguments(node.arguments);
|
||
|
||
// TODO(http://dartbug.com/31799): Ensure we only invoke ==/!= on
|
||
// null/bool/int/double/String objects.
|
||
|
||
// Handle == and != first (it's common between all types).
|
||
if (arguments.length == 1 && node.name.name == '==') {
|
||
final right = arguments[0];
|
||
return receiver == right ? trueConstant : falseConstant;
|
||
}
|
||
if (arguments.length == 1 && node.name.name == '!=') {
|
||
final right = arguments[0];
|
||
return receiver != right ? trueConstant : falseConstant;
|
||
}
|
||
|
||
// This is a white-listed set of methods we need to support on constants.
|
||
if (receiver is StringConstant) {
|
||
if (arguments.length == 1) {
|
||
switch (node.name.name) {
|
||
case '+':
|
||
final Constant other = arguments[0];
|
||
if (other is StringConstant) {
|
||
return canonicalize(
|
||
new StringConstant(receiver.value + other.value));
|
||
}
|
||
throw new _AbortCurrentEvaluation(
|
||
errorReporter.invalidBinaryOperandType(
|
||
contextChain,
|
||
node,
|
||
receiver,
|
||
'+',
|
||
typeEnvironment.stringType,
|
||
other.getType(typeEnvironment)));
|
||
}
|
||
}
|
||
} else if (receiver is BoolConstant) {
|
||
if (arguments.length == 1) {
|
||
switch (node.name.name) {
|
||
case '!':
|
||
return !receiver.value ? trueConstant : falseConstant;
|
||
}
|
||
} else if (arguments.length == 2) {
|
||
final right = arguments[0];
|
||
if (right is BoolConstant) {
|
||
switch (node.name.name) {
|
||
case '&&':
|
||
return (receiver.value && right.value)
|
||
? trueConstant
|
||
: falseConstant;
|
||
case '||':
|
||
return (receiver.value || right.value)
|
||
? trueConstant
|
||
: falseConstant;
|
||
}
|
||
}
|
||
throw new _AbortCurrentEvaluation(
|
||
errorReporter.invalidBinaryOperandType(
|
||
contextChain,
|
||
node,
|
||
receiver,
|
||
'${node.name.name}',
|
||
typeEnvironment.boolType,
|
||
right.getType(typeEnvironment)));
|
||
}
|
||
} else if (receiver is IntConstant) {
|
||
if (arguments.length == 0) {
|
||
switch (node.name.name) {
|
||
case 'unary-':
|
||
return canonicalize(new IntConstant(-receiver.value));
|
||
case '~':
|
||
return canonicalize(new IntConstant(~receiver.value));
|
||
}
|
||
} else if (arguments.length == 1) {
|
||
final Constant other = arguments[0];
|
||
final op = node.name.name;
|
||
if (other is IntConstant) {
|
||
if ((op == '<<' || op == '>>') && other.value < 0) {
|
||
throw new _AbortCurrentEvaluation(errorReporter.negativeShift(
|
||
contextChain,
|
||
node.arguments.positional.first,
|
||
receiver,
|
||
op,
|
||
other));
|
||
}
|
||
switch (op) {
|
||
case '|':
|
||
return canonicalize(
|
||
new IntConstant(receiver.value | other.value));
|
||
case '&':
|
||
return canonicalize(
|
||
new IntConstant(receiver.value & other.value));
|
||
case '^':
|
||
return canonicalize(
|
||
new IntConstant(receiver.value ^ other.value));
|
||
case '<<':
|
||
return canonicalize(
|
||
new IntConstant(receiver.value << other.value));
|
||
case '>>':
|
||
return canonicalize(
|
||
new IntConstant(receiver.value >> other.value));
|
||
}
|
||
}
|
||
|
||
if (other is IntConstant) {
|
||
if (other.value == 0 && (op == '%' || op == '~/')) {
|
||
throw new _AbortCurrentEvaluation(errorReporter.zeroDivisor(
|
||
contextChain, node.arguments.positional.first, receiver, op));
|
||
}
|
||
|
||
return evaluateBinaryNumericOperation(
|
||
node.name.name, receiver.value, other.value, node);
|
||
} else if (other is DoubleConstant) {
|
||
return evaluateBinaryNumericOperation(
|
||
node.name.name, receiver.value, other.value, node);
|
||
}
|
||
throw new _AbortCurrentEvaluation(
|
||
errorReporter.invalidBinaryOperandType(
|
||
contextChain,
|
||
node,
|
||
receiver,
|
||
'${node.name.name}',
|
||
typeEnvironment.numType,
|
||
other.getType(typeEnvironment)));
|
||
}
|
||
} else if (receiver is DoubleConstant) {
|
||
if (arguments.length == 0) {
|
||
switch (node.name.name) {
|
||
case 'unary-':
|
||
return canonicalize(new DoubleConstant(-receiver.value));
|
||
}
|
||
} else if (arguments.length == 1) {
|
||
final Constant other = arguments[0];
|
||
|
||
if (other is IntConstant || other is DoubleConstant) {
|
||
final num value = (other is IntConstant)
|
||
? other.value
|
||
: (other as DoubleConstant).value;
|
||
return evaluateBinaryNumericOperation(
|
||
node.name.name, receiver.value, value, node);
|
||
}
|
||
throw new _AbortCurrentEvaluation(
|
||
errorReporter.invalidBinaryOperandType(
|
||
contextChain,
|
||
node,
|
||
receiver,
|
||
'${node.name.name}',
|
||
typeEnvironment.numType,
|
||
other.getType(typeEnvironment)));
|
||
}
|
||
}
|
||
throw new _AbortCurrentEvaluation(errorReporter.invalidMethodInvocation(
|
||
contextChain, node, receiver, node.name.name));
|
||
}
|
||
|
||
visitLogicalExpression(LogicalExpression node) {
|
||
final Constant left = _evaluateSubexpression(node.left);
|
||
switch (node.operator) {
|
||
case '||':
|
||
if (left is BoolConstant) {
|
||
if (left.value) return trueConstant;
|
||
|
||
final Constant right = _evaluateSubexpression(node.right);
|
||
if (right is BoolConstant) {
|
||
return right;
|
||
}
|
||
|
||
throw new _AbortCurrentEvaluation(
|
||
errorReporter.invalidBinaryOperandType(
|
||
contextChain,
|
||
node,
|
||
left,
|
||
'${node.operator}',
|
||
typeEnvironment.boolType,
|
||
right.getType(typeEnvironment)));
|
||
}
|
||
throw new _AbortCurrentEvaluation(errorReporter.invalidMethodInvocation(
|
||
contextChain, node, left, '${node.operator}'));
|
||
case '&&':
|
||
if (left is BoolConstant) {
|
||
if (!left.value) return falseConstant;
|
||
|
||
final Constant right = _evaluateSubexpression(node.right);
|
||
if (right is BoolConstant) {
|
||
return right;
|
||
}
|
||
throw new _AbortCurrentEvaluation(
|
||
errorReporter.invalidBinaryOperandType(
|
||
contextChain,
|
||
node,
|
||
left,
|
||
'${node.operator}',
|
||
typeEnvironment.boolType,
|
||
right.getType(typeEnvironment)));
|
||
}
|
||
throw new _AbortCurrentEvaluation(errorReporter.invalidMethodInvocation(
|
||
contextChain, node, left, '${node.operator}'));
|
||
case '??':
|
||
return (left is! NullConstant)
|
||
? left
|
||
: _evaluateSubexpression(node.right);
|
||
default:
|
||
throw new _AbortCurrentEvaluation(errorReporter.invalidMethodInvocation(
|
||
contextChain, node, left, '${node.operator}'));
|
||
}
|
||
}
|
||
|
||
visitConditionalExpression(ConditionalExpression node) {
|
||
final Constant constant = _evaluateSubexpression(node.condition);
|
||
if (constant == trueConstant) {
|
||
return _evaluateSubexpression(node.then);
|
||
} else if (constant == falseConstant) {
|
||
return _evaluateSubexpression(node.otherwise);
|
||
} else {
|
||
throw new _AbortCurrentEvaluation(errorReporter.invalidDartType(
|
||
contextChain, node, constant, typeEnvironment.boolType));
|
||
}
|
||
}
|
||
|
||
visitPropertyGet(PropertyGet node) {
|
||
if (node.receiver is ThisExpression) {
|
||
// Access "this" during instance creation.
|
||
for (final Field field in instanceBuilder.fields.keys) {
|
||
if (field.name == node.name) {
|
||
return instanceBuilder.fields[field];
|
||
}
|
||
}
|
||
throw 'Could not evaluate field get ${node.name} on incomplete instance';
|
||
}
|
||
|
||
final Constant receiver = _evaluateSubexpression(node.receiver);
|
||
if (receiver is StringConstant && node.name.name == 'length') {
|
||
return canonicalize(new IntConstant(receiver.value.length));
|
||
} else if (receiver is InstanceConstant) {
|
||
for (final Reference fieldRef in receiver.fieldValues.keys) {
|
||
if (fieldRef.asField.name == node.name) {
|
||
return receiver.fieldValues[fieldRef];
|
||
}
|
||
}
|
||
}
|
||
throw 'Could not evaluate property get on $receiver.';
|
||
}
|
||
|
||
visitLet(Let node) {
|
||
env.addVariableValue(
|
||
node.variable, _evaluateSubexpression(node.variable.initializer));
|
||
return node.body.accept(this);
|
||
}
|
||
|
||
visitVariableGet(VariableGet node) {
|
||
// Not every variable which a [VariableGet] refers to must be marked as
|
||
// constant. For example function parameters as well as constructs
|
||
// desugared to [Let] expressions are ok.
|
||
//
|
||
// TODO(kustermann): The heuristic of allowing all [VariableGet]s on [Let]
|
||
// variables might allow more than it should.
|
||
final VariableDeclaration variable = node.variable;
|
||
if (variable.parent is Let || _isFormalParameter(variable)) {
|
||
final Constant constant = env.lookupVariable(node.variable);
|
||
if (constant == null) {
|
||
throw new _AbortCurrentEvaluation(errorReporter.nonConstantVariableGet(
|
||
contextChain, node, variable.name));
|
||
}
|
||
return constant;
|
||
}
|
||
if (variable.isConst) {
|
||
return _evaluateSubexpression(variable.initializer);
|
||
}
|
||
throw new Exception('The front-end should ensure we do not encounter a '
|
||
'variable get of a non-const variable.');
|
||
}
|
||
|
||
visitStaticGet(StaticGet node) {
|
||
return withNewEnvironment(() {
|
||
final Member target = node.target;
|
||
if (target is Field) {
|
||
if (target.isConst) {
|
||
return runInsideContext(target, () {
|
||
return _evaluateSubexpression(target.initializer);
|
||
});
|
||
}
|
||
throw new _AbortCurrentEvaluation(
|
||
errorReporter.invalidStaticInvocation(contextChain, node, target));
|
||
} else if (target is Procedure) {
|
||
if (target.kind == ProcedureKind.Method) {
|
||
return canonicalize(new TearOffConstant(target));
|
||
}
|
||
throw new _AbortCurrentEvaluation(
|
||
errorReporter.invalidStaticInvocation(contextChain, node, target));
|
||
} else {
|
||
throw new Exception(
|
||
'No support for ${target.runtimeType} in a static-get.');
|
||
}
|
||
});
|
||
}
|
||
|
||
visitStringConcatenation(StringConcatenation node) {
|
||
final String value = node.expressions.map((Expression node) {
|
||
final Constant constant = node.accept(this);
|
||
|
||
if (constant is NullConstant) {
|
||
return 'null';
|
||
} else if (constant is BoolConstant) {
|
||
return constant.value ? 'true' : 'false';
|
||
} else if (constant is IntConstant) {
|
||
return constant.value.toString();
|
||
} else if (constant is DoubleConstant) {
|
||
return constant.value.toString();
|
||
} else if (constant is StringConstant) {
|
||
return constant.value;
|
||
} else {
|
||
throw new _AbortCurrentEvaluation(errorReporter
|
||
.invalidStringInterpolationOperand(contextChain, node, constant));
|
||
}
|
||
}).join('');
|
||
return canonicalize(new StringConstant(value));
|
||
}
|
||
|
||
visitStaticInvocation(StaticInvocation node) {
|
||
final Procedure target = node.target;
|
||
if (target.kind == ProcedureKind.Factory) {
|
||
final String nativeName = getExternalName(target);
|
||
if (nativeName != null) {
|
||
final Constant constant = backend.buildConstantForNative(
|
||
nativeName,
|
||
evaluateTypeArguments(node, node.arguments),
|
||
evaluatePositionalArguments(node.arguments),
|
||
evaluateNamedArguments(node.arguments),
|
||
contextChain,
|
||
node,
|
||
errorReporter,
|
||
(String message) => throw new _AbortCurrentEvaluation(message));
|
||
assert(constant != null);
|
||
return canonicalize(constant);
|
||
}
|
||
} else if (target.name.name == 'identical') {
|
||
// Ensure the "identical()" function comes from dart:core.
|
||
final parent = target.parent;
|
||
if (parent is Library && parent == coreTypes.coreLibrary) {
|
||
final positionalArguments = evaluatePositionalArguments(node.arguments);
|
||
final Constant left = positionalArguments[0];
|
||
final Constant right = positionalArguments[1];
|
||
// Since we canonicalize constants during the evaluation, we can use
|
||
// identical here.
|
||
return identical(left, right) ? trueConstant : falseConstant;
|
||
}
|
||
}
|
||
throw new _AbortCurrentEvaluation(
|
||
errorReporter.invalidStaticInvocation(contextChain, node, target));
|
||
}
|
||
|
||
visitAsExpression(AsExpression node) {
|
||
final Constant constant = node.operand.accept(this);
|
||
ensureIsSubtype(constant, evaluateDartType(node, node.type), node);
|
||
return constant;
|
||
}
|
||
|
||
visitNot(Not node) {
|
||
final Constant constant = node.operand.accept(this);
|
||
if (constant is BoolConstant) {
|
||
return constant == trueConstant ? falseConstant : trueConstant;
|
||
}
|
||
throw new _AbortCurrentEvaluation(errorReporter.invalidDartType(
|
||
contextChain, node, constant, typeEnvironment.boolType));
|
||
}
|
||
|
||
visitSymbolLiteral(SymbolLiteral node) {
|
||
final libraryReference =
|
||
node.value.startsWith('_') ? libraryOf(node).reference : null;
|
||
return canonicalize(new SymbolConstant(node.value, libraryReference));
|
||
}
|
||
|
||
visitInstantiation(Instantiation node) {
|
||
final Constant constant = _evaluateSubexpression(node.expression);
|
||
if (constant is TearOffConstant) {
|
||
if (node.typeArguments.length ==
|
||
constant.procedure.function.typeParameters.length) {
|
||
final typeArguments = evaluateDartTypes(node, node.typeArguments);
|
||
return canonicalize(
|
||
new PartialInstantiationConstant(constant, typeArguments));
|
||
}
|
||
throw new Exception(
|
||
'The number of type arguments supplied in the partial instantiation '
|
||
'does not match the number of type arguments of the $constant.');
|
||
}
|
||
throw new Exception(
|
||
'Only tear-off constants can be partially instantiated.');
|
||
}
|
||
|
||
@override
|
||
visitCheckLibraryIsLoaded(CheckLibraryIsLoaded node) {
|
||
throw new _AbortCurrentEvaluation(
|
||
errorReporter.deferredLibrary(contextChain, node, node.import.name));
|
||
}
|
||
|
||
// Helper methods:
|
||
|
||
void ensureIsSubtype(Constant constant, DartType type, TreeNode node) {
|
||
DartType constantType = constant.getType(typeEnvironment);
|
||
|
||
if (!typeEnvironment.isSubtypeOf(constantType, type)) {
|
||
throw new _AbortCurrentEvaluation(
|
||
errorReporter.invalidDartType(contextChain, node, constant, type));
|
||
}
|
||
}
|
||
|
||
List<DartType> evaluateTypeArguments(TreeNode node, Arguments arguments) {
|
||
return evaluateDartTypes(node, arguments.types);
|
||
}
|
||
|
||
List<DartType> evaluateSuperTypeArguments(TreeNode node, Supertype type) {
|
||
return evaluateDartTypes(node, type.typeArguments);
|
||
}
|
||
|
||
List<DartType> evaluateDartTypes(TreeNode node, List<DartType> types) {
|
||
// TODO: Once the frontend gurantees that there are no free type variables
|
||
// left over after stubstitution, we can enable this shortcut again:
|
||
// if (env.isEmpty) return types;
|
||
return types.map((t) => evaluateDartType(node, t)).toList();
|
||
}
|
||
|
||
DartType evaluateDartType(TreeNode node, DartType type) {
|
||
final result = env.subsituteType(type);
|
||
|
||
if (!isInstantiated(result)) {
|
||
throw new _AbortCurrentEvaluation(
|
||
errorReporter.freeTypeParameter(contextChain, node, type));
|
||
}
|
||
|
||
return result;
|
||
}
|
||
|
||
List<Constant> evaluatePositionalArguments(Arguments arguments) {
|
||
return arguments.positional.map((Expression node) {
|
||
return node.accept(this) as Constant;
|
||
}).toList();
|
||
}
|
||
|
||
Map<String, Constant> evaluateNamedArguments(Arguments arguments) {
|
||
if (arguments.named.isEmpty) return const <String, Constant>{};
|
||
|
||
final Map<String, Constant> named = {};
|
||
arguments.named.forEach((NamedExpression pair) {
|
||
named[pair.name] = pair.value.accept(this);
|
||
});
|
||
return named;
|
||
}
|
||
|
||
canonicalize(Constant constant) {
|
||
return canonicalizationCache.putIfAbsent(constant, () => constant);
|
||
}
|
||
|
||
withNewInstanceBuilder(Class klass, List<DartType> typeArguments, fn()) {
|
||
InstanceBuilder old = instanceBuilder;
|
||
try {
|
||
instanceBuilder = new InstanceBuilder(klass, typeArguments);
|
||
return fn();
|
||
} finally {
|
||
instanceBuilder = old;
|
||
}
|
||
}
|
||
|
||
withNewEnvironment(fn()) {
|
||
final EvaluationEnvironment oldEnv = env;
|
||
try {
|
||
env = new EvaluationEnvironment();
|
||
return fn();
|
||
} finally {
|
||
env = oldEnv;
|
||
}
|
||
}
|
||
|
||
evaluateBinaryNumericOperation(String op, num a, num b, TreeNode node) {
|
||
num result;
|
||
switch (op) {
|
||
case '+':
|
||
result = a + b;
|
||
break;
|
||
case '-':
|
||
result = a - b;
|
||
break;
|
||
case '*':
|
||
result = a * b;
|
||
break;
|
||
case '/':
|
||
result = a / b;
|
||
break;
|
||
case '~/':
|
||
result = a ~/ b;
|
||
break;
|
||
case '%':
|
||
result = a % b;
|
||
break;
|
||
}
|
||
|
||
if (result != null) {
|
||
return canonicalize(result is int
|
||
? new IntConstant(result.toSigned(64))
|
||
: new DoubleConstant(result as double));
|
||
}
|
||
|
||
switch (op) {
|
||
case '<':
|
||
return a < b ? trueConstant : falseConstant;
|
||
case '<=':
|
||
return a <= b ? trueConstant : falseConstant;
|
||
case '>=':
|
||
return a >= b ? trueConstant : falseConstant;
|
||
case '>':
|
||
return a > b ? trueConstant : falseConstant;
|
||
}
|
||
|
||
throw new Exception("Unexpected binary numeric operation '$op'.");
|
||
}
|
||
|
||
Library libraryOf(TreeNode node) {
|
||
// The tree structure of the kernel AST ensures we always have an enclosing
|
||
// library.
|
||
while (true) {
|
||
if (node is Library) return node;
|
||
node = node.parent;
|
||
}
|
||
}
|
||
}
|
||
|
||
/// Holds the necessary information for a constant object, namely
|
||
/// * the [klass] being instantiated
|
||
/// * the [typeArguments] used for the instantiation
|
||
/// * the [fields] the instance will obtain (all fields from the
|
||
/// instantiated [klass] up to the [Object] klass).
|
||
class InstanceBuilder {
|
||
/// The class of the new instance.
|
||
final Class klass;
|
||
|
||
/// The values of the type parameters of the new instance.
|
||
final List<DartType> typeArguments;
|
||
|
||
/// The field values of the new instance.
|
||
final Map<Field, Constant> fields = <Field, Constant>{};
|
||
|
||
InstanceBuilder(this.klass, this.typeArguments);
|
||
|
||
void setFieldValue(Field field, Constant constant) {
|
||
fields[field] = constant;
|
||
}
|
||
|
||
InstanceConstant buildInstance() {
|
||
final Map<Reference, Constant> fieldValues = <Reference, Constant>{};
|
||
fields.forEach((Field field, Constant value) {
|
||
fieldValues[field.reference] = value;
|
||
});
|
||
return new InstanceConstant(klass.reference, typeArguments, fieldValues);
|
||
}
|
||
}
|
||
|
||
/// Holds an environment of type parameters, parameters and variables.
|
||
class EvaluationEnvironment {
|
||
/// The values of the type parameters in scope.
|
||
final Map<TypeParameter, DartType> _typeVariables =
|
||
<TypeParameter, DartType>{};
|
||
|
||
/// The values of the parameters/variables in scope.
|
||
final Map<VariableDeclaration, Constant> _variables =
|
||
<VariableDeclaration, Constant>{};
|
||
|
||
/// Whether the current environment is empty.
|
||
bool get isEmpty => _typeVariables.isEmpty && _variables.isEmpty;
|
||
|
||
void addTypeParameterValue(TypeParameter parameter, DartType value) {
|
||
assert(!_typeVariables.containsKey(parameter));
|
||
_typeVariables[parameter] = value;
|
||
}
|
||
|
||
void addVariableValue(VariableDeclaration variable, Constant value) {
|
||
assert(!_variables.containsKey(variable));
|
||
_variables[variable] = value;
|
||
}
|
||
|
||
DartType lookupParameterValue(TypeParameter parameter) {
|
||
final DartType value = _typeVariables[parameter];
|
||
assert(value != null);
|
||
return value;
|
||
}
|
||
|
||
Constant lookupVariable(VariableDeclaration variable) {
|
||
return _variables[variable];
|
||
}
|
||
|
||
DartType subsituteType(DartType type) {
|
||
if (_typeVariables.isEmpty) return type;
|
||
return substitute(type, _typeVariables);
|
||
}
|
||
}
|
||
|
||
abstract class ConstantsBackend {
|
||
Constant buildConstantForNative(
|
||
String nativeName,
|
||
List<DartType> typeArguments,
|
||
List<Constant> positionalArguments,
|
||
Map<String, Constant> namedArguments,
|
||
List<TreeNode> context,
|
||
StaticInvocation node,
|
||
ErrorReporter errorReporter,
|
||
Constant abortEvaluation(String message));
|
||
Constant lowerListConstant(ListConstant constant);
|
||
Constant lowerMapConstant(MapConstant constant);
|
||
}
|
||
|
||
// Used as control-flow to abort the current evaluation.
|
||
class _AbortCurrentEvaluation {
|
||
final String message;
|
||
_AbortCurrentEvaluation(this.message);
|
||
}
|
||
|
||
abstract class ErrorReporter {
|
||
const ErrorReporter();
|
||
|
||
Uri getFileUri(TreeNode node) {
|
||
while (node is! FileUriNode) {
|
||
node = node.parent;
|
||
}
|
||
return (node as FileUriNode).fileUri;
|
||
}
|
||
|
||
int getFileOffset(TreeNode node) {
|
||
while (node.fileOffset == TreeNode.noOffset) {
|
||
node = node.parent;
|
||
}
|
||
return node == null ? TreeNode.noOffset : node.fileOffset;
|
||
}
|
||
|
||
String freeTypeParameter(
|
||
List<TreeNode> context, TreeNode node, DartType type);
|
||
String invalidDartType(List<TreeNode> context, TreeNode node,
|
||
Constant receiver, DartType expectedType);
|
||
String invalidBinaryOperandType(List<TreeNode> context, TreeNode node,
|
||
Constant receiver, String op, DartType expectedType, DartType actualType);
|
||
String invalidMethodInvocation(
|
||
List<TreeNode> context, TreeNode node, Constant receiver, String op);
|
||
String invalidStaticInvocation(
|
||
List<TreeNode> context, TreeNode node, Member target);
|
||
String invalidStringInterpolationOperand(
|
||
List<TreeNode> context, TreeNode node, Constant constant);
|
||
String invalidSymbolName(
|
||
List<TreeNode> context, TreeNode node, Constant constant);
|
||
String zeroDivisor(
|
||
List<TreeNode> context, TreeNode node, IntConstant receiver, String op);
|
||
String negativeShift(List<TreeNode> context, TreeNode node,
|
||
IntConstant receiver, String op, IntConstant argument);
|
||
String nonConstLiteral(List<TreeNode> context, TreeNode node, String klass);
|
||
String duplicateKey(List<TreeNode> context, TreeNode node, Constant key);
|
||
String failedAssertion(List<TreeNode> context, TreeNode node, String message);
|
||
String nonConstantVariableGet(
|
||
List<TreeNode> context, TreeNode node, String variableName);
|
||
String deferredLibrary(
|
||
List<TreeNode> context, TreeNode node, String importName);
|
||
String circularity(List<TreeNode> context, TreeNode node);
|
||
}
|
||
|
||
class SimpleErrorReporter extends ErrorReporter {
|
||
const SimpleErrorReporter();
|
||
|
||
String report(List<TreeNode> context, String what, TreeNode node) {
|
||
io.exitCode = 42;
|
||
final Uri uri = getFileUri(node);
|
||
final int fileOffset = getFileOffset(node);
|
||
final String message = '$uri:$fileOffset Constant evaluation error: $what';
|
||
io.stderr.writeln(message);
|
||
return message;
|
||
}
|
||
|
||
@override
|
||
String freeTypeParameter(
|
||
List<TreeNode> context, TreeNode node, DartType type) {
|
||
return report(
|
||
context, 'Expected type to be instantiated but was ${type}', node);
|
||
}
|
||
|
||
@override
|
||
String invalidDartType(List<TreeNode> context, TreeNode node,
|
||
Constant receiver, DartType expectedType) {
|
||
return report(
|
||
context,
|
||
'Expected expression to evaluate to "$expectedType" but got "$receiver.',
|
||
node);
|
||
}
|
||
|
||
@override
|
||
String invalidBinaryOperandType(
|
||
List<TreeNode> context,
|
||
TreeNode node,
|
||
Constant receiver,
|
||
String op,
|
||
DartType expectedType,
|
||
DartType actualType) {
|
||
return report(
|
||
context,
|
||
'Calling "$op" on "$receiver" needs operand of type '
|
||
'"$expectedType" (but got "$actualType")',
|
||
node);
|
||
}
|
||
|
||
@override
|
||
String invalidMethodInvocation(
|
||
List<TreeNode> context, TreeNode node, Constant receiver, String op) {
|
||
return report(context,
|
||
'Cannot call "$op" on "$receiver" in constant expression', node);
|
||
}
|
||
|
||
@override
|
||
String invalidStaticInvocation(
|
||
List<TreeNode> context, TreeNode node, Member target) {
|
||
return report(
|
||
context, 'Cannot invoke "$target" inside a constant expression', node);
|
||
}
|
||
|
||
@override
|
||
String invalidStringInterpolationOperand(
|
||
List<TreeNode> context, TreeNode node, Constant constant) {
|
||
return report(
|
||
context,
|
||
'Only null/bool/int/double/String values are allowed as string '
|
||
'interpolation expressions during constant evaluation (was: "$constant").',
|
||
node);
|
||
}
|
||
|
||
@override
|
||
String invalidSymbolName(
|
||
List<TreeNode> context, TreeNode node, Constant constant) {
|
||
return report(
|
||
context,
|
||
'The symbol name must be a valid public Dart member name, public '
|
||
'constructor name, or library name, optionally qualified.',
|
||
node);
|
||
}
|
||
|
||
@override
|
||
String zeroDivisor(
|
||
List<TreeNode> context, TreeNode node, IntConstant receiver, String op) {
|
||
return report(
|
||
context,
|
||
"Binary operator '$op' on '${receiver.value}' requires non-zero "
|
||
"divisor, but divisor was '0'.",
|
||
node);
|
||
}
|
||
|
||
@override
|
||
String negativeShift(List<TreeNode> context, TreeNode node,
|
||
IntConstant receiver, String op, IntConstant argument) {
|
||
return report(
|
||
context,
|
||
"Binary operator '$op' on '${receiver.value}' requires non-negative "
|
||
"operand, but was '${argument.value}'.",
|
||
node);
|
||
}
|
||
|
||
@override
|
||
String nonConstLiteral(List<TreeNode> context, TreeNode node, String klass) {
|
||
return report(
|
||
context,
|
||
'Cannot have a non-constant $klass literal within a const context.',
|
||
node);
|
||
}
|
||
|
||
@override
|
||
String duplicateKey(List<TreeNode> context, TreeNode node, Constant key) {
|
||
return report(
|
||
context,
|
||
'Duplicate keys are not allowed in constant maps (found duplicate key "$key")',
|
||
node);
|
||
}
|
||
|
||
@override
|
||
String failedAssertion(
|
||
List<TreeNode> context, TreeNode node, String message) {
|
||
return report(
|
||
context,
|
||
'The assertion condition evaluated to "false" with message "$message"',
|
||
node);
|
||
}
|
||
|
||
@override
|
||
String nonConstantVariableGet(
|
||
List<TreeNode> context, TreeNode node, String variableName) {
|
||
return report(
|
||
context,
|
||
'The variable "$variableName" cannot be used inside a constant '
|
||
'expression.',
|
||
node);
|
||
}
|
||
|
||
@override
|
||
String deferredLibrary(
|
||
List<TreeNode> context, TreeNode node, String importName) {
|
||
return report(
|
||
context,
|
||
'Deferred "$importName" cannot be used inside a constant '
|
||
'expression',
|
||
node);
|
||
}
|
||
|
||
@override
|
||
String circularity(List<TreeNode> context, TreeNode node) {
|
||
return report(context, 'Constant expression depends on itself.', node);
|
||
}
|
||
}
|
||
|
||
class IsInstantiatedVisitor extends DartTypeVisitor<bool> {
|
||
final _availableVariables = new Set<TypeParameter>();
|
||
|
||
bool isInstantiated(DartType type) {
|
||
return type.accept(this);
|
||
}
|
||
|
||
bool defaultDartType(DartType node) {
|
||
throw 'A visitor method seems to be unimplemented!';
|
||
}
|
||
|
||
bool visitInvalidType(InvalidType node) => true;
|
||
bool visitDynamicType(DynamicType node) => true;
|
||
bool visitVoidType(VoidType node) => true;
|
||
bool visitBottomType(BottomType node) => true;
|
||
|
||
bool visitTypeParameterType(TypeParameterType node) {
|
||
return _availableVariables.contains(node.parameter);
|
||
}
|
||
|
||
bool visitInterfaceType(InterfaceType node) {
|
||
return node.typeArguments
|
||
.every((DartType typeArgument) => typeArgument.accept(this));
|
||
}
|
||
|
||
bool visitFunctionType(FunctionType node) {
|
||
final parameters = node.typeParameters;
|
||
_availableVariables.addAll(parameters);
|
||
final bool result = node.returnType.accept(this) &&
|
||
node.positionalParameters.every((p) => p.accept(this)) &&
|
||
node.namedParameters.every((p) => p.type.accept(this));
|
||
_availableVariables.removeAll(parameters);
|
||
return result;
|
||
}
|
||
|
||
bool visitTypedefType(TypedefType node) {
|
||
return node.unalias.accept(this);
|
||
}
|
||
}
|
||
|
||
bool _isFormalParameter(VariableDeclaration variable) {
|
||
final parent = variable.parent;
|
||
if (parent is FunctionNode) {
|
||
return parent.positionalParameters.contains(variable) ||
|
||
parent.namedParameters.contains(variable);
|
||
}
|
||
return false;
|
||
}
|