Linter Demo

Errors: 1

Warnings: 4

File: /home/fstrocco/Dart/dart/benchmark/compiler/lib/src/dart_backend/renamer.dart

// Copyright (c) 2012, 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. part of dart_backend; Comparator get _compareNodes => compareBy((n) => n.getBeginToken().charOffset); abstract class Renamable implements Comparable { final int RENAMABLE_TYPE_ELEMENT = 1; final int RENAMABLE_TYPE_MEMBER = 2; final int RENAMABLE_TYPE_LOCAL = 3; final Set<Node> nodes; Renamable(this.nodes); int compareTo(Renamable other) { int nodesDiff = other.nodes.length.compareTo(this.nodes.length); if (nodesDiff != 0) return nodesDiff; int typeDiff = this.kind.compareTo(other.kind); return typeDiff != 0 ? typeDiff : compareInternals(other); } int compareInternals(Renamable other); int get kind; String createNewName(PlaceholderRenamer placeholderRenamer); } class GlobalRenamable extends Renamable { final Entity entity; GlobalRenamable(this.entity, Set<Node> nodes) : super(nodes); int compareInternals(GlobalRenamable other) => compareElements(this.entity, other.entity); int get kind => RENAMABLE_TYPE_ELEMENT; String createNewName(PlaceholderRenamer placeholderRenamer) { return placeholderRenamer._renameGlobal(entity); } } class MemberRenamable extends Renamable { final String identifier; MemberRenamable(this.identifier, Set<Node> nodes) : super(nodes); int compareInternals(MemberRenamable other) => this.identifier.compareTo(other.identifier); int get kind => RENAMABLE_TYPE_MEMBER; String createNewName(PlaceholderRenamer placeholderRenamer) { return placeholderRenamer._generateMemberName(identifier); } } class LocalRenamable extends Renamable { LocalRenamable(Set<Node> nodes) : super(nodes); int compareInternals(LocalRenamable other) => _compareNodes(sorted(this.nodes, _compareNodes)[0], sorted(other.nodes, _compareNodes)[0]); int get kind => RENAMABLE_TYPE_LOCAL; String createNewName(PlaceholderRenamer placeholderRenamer) { return placeholderRenamer._generateUniqueTopLevelName(""); } } /** * Renames only top-level elements that would lead to ambiguity if not renamed. */ class PlaceholderRenamer { /// After running [computeRenames] this will contain the computed renames. final Map<Node, String> renames = new Map<Node, String>(); /// After running [computeRenames] this will map the used platform /// libraries to their respective prefixes. final Map<LibraryElement, String> platformImports = <LibraryElement, String>{}; final bool enableMinification; final Set<String> fixedDynamicNames; final Set<String> fixedStaticNames; final Map<Element, LibraryElement> reexportingLibraries; final bool cutDeclarationTypes; final Map<Entity, String> _renamedCache = new Map<Entity, String>(); final Map<Entity, Map<String, String>> _privateCache = new Map<Entity, Map<String, String>>(); // Identifiers that has already been used, or are reserved by the // language/platform. Set<String> _forbiddenIdentifiers; Set<String> _allNamedParameterIdentifiers; Generator _generator; PlaceholderRenamer(this.fixedDynamicNames, this.fixedStaticNames, this.reexportingLibraries, {this.enableMinification, this.cutDeclarationTypes}); void _renameNodes(Iterable<Node> nodes, String renamer(Node node)) { for (Node node in sorted(nodes, _compareNodes)) { renames[node] = renamer(node); } } String _generateUniqueTopLevelName(String originalName) { String newName = _generator.generate(originalName, (name) { return _forbiddenIdentifiers.contains(name) || _allNamedParameterIdentifiers.contains(name); }); _forbiddenIdentifiers.add(newName); return newName; } String _generateMemberName(String original) { return _generator.generate(original, _forbiddenIdentifiers.contains); } /// Looks up [originalName] in the [_privateCache] cache of [library]. /// If [originalName] was not renamed before, generate a new name. String _getPrivateName(LibraryElement library, String originalName) { return _privateCache.putIfAbsent(library, () => new Map<String, String>()) .putIfAbsent(originalName, () => _generateUniqueTopLevelName(originalName)); } String _renameConstructor(ConstructorPlaceholder placeholder) { String name = placeholder.element.name; if (name == '') return ""; String result = _renameGlobal(placeholder.element); return result; } String _renameGlobal(Entity entity) { assert(entity is! Element || Elements.isErroneous(entity) || Elements.isStaticOrTopLevel(entity) || entity is TypeVariableElement); // TODO(smok): We may want to reuse class static field and method names. if (entity is Element) { LibraryElement library = entity.library; if (reexportingLibraries.containsKey(entity)) { library = reexportingLibraries[entity]; } if (library.isPlatformLibrary) { // TODO(johnniwinther): Handle prefixes for dart:core. if (library.canonicalUri == Compiler.DART_CORE) return entity.name; if (library.isInternalLibrary) { throw new SpannableAssertionFailure(entity, "Internal library $library should never have been imported from " "the code compiled by dart2dart."); } String prefix = platformImports.putIfAbsent(library, () => null); if (entity.isTopLevel && fixedDynamicNames.contains(entity.name)) { if (prefix == null) { prefix = _generateUniqueTopLevelName(''); platformImports[library] = prefix; } return '$prefix.${entity.name}'; } return entity.name; } } String name = _renamedCache.putIfAbsent(entity, () => _generateUniqueTopLevelName(entity.name)); // Look up in [_renamedCache] for a name for [entity] . // If it was not renamed before, generate a new name. return name; } void _computeMinifiedRenames(PlaceholderCollector placeholderCollector) { _generator = new MinifyingGenerator(); // Build a list sorted by usage of local nodes that will be renamed to // the same identifier. So the top-used local variables in all functions // will be renamed first and will all share the same new identifier. int maxLength = placeholderCollector.functionScopes.values.fold(0, (a, b) => max(a, b.localPlaceholders.length)); List<Set<Node>> allLocals = new List<Set<Node>> .generate(maxLength, (_) => new Set<Node>()); for (FunctionScope functionScope in placeholderCollector.functionScopes.values) { // Add current sorted local identifiers to the whole sorted list // of all local identifiers for all functions. List<LocalPlaceholder> currentSortedPlaceholders = sorted(functionScope.localPlaceholders, compareBy((LocalPlaceholder ph) => -ph.nodes.length)); List<Set<Node>> currentSortedNodes = currentSortedPlaceholders .map((LocalPlaceholder ph) => ph.nodes).toList(); for (int i = 0; i < currentSortedNodes.length; i++) { allLocals[i].addAll(currentSortedNodes[i]); } } // Rename elements, members and locals together based on their usage // count, otherwise when we rename elements first there will be no good // identifiers left for members even if they are used often. List<Renamable> renamables = new List<Renamable>(); placeholderCollector.elementNodes.forEach( (Element element, Set<Node> nodes) { renamables.add(new GlobalRenamable(element, nodes)); }); placeholderCollector.memberPlaceholders.forEach( (String memberName, Set<Identifier> identifiers) { renamables.add(new MemberRenamable(memberName, identifiers)); }); for (Set<Node> localIdentifiers in allLocals) { renamables.add(new LocalRenamable(localIdentifiers)); } renamables.sort(); for (Renamable renamable in renamables) { String newName = renamable.createNewName(this); _renameNodes(renamable.nodes, (_) => newName); } } void _computeNonMinifiedRenames(PlaceholderCollector placeholderCollector) { _generator = new ConservativeGenerator(); // Rename elements. placeholderCollector.elementNodes.forEach( (Element element, Set<Node> nodes) { _renameNodes(nodes, (_) => _renameGlobal(element)); }); // Rename locals. placeholderCollector.functionScopes.forEach( (functionElement, functionScope) { Set<String> memberIdentifiers = new Set<String>(); Set<LocalPlaceholder> placeholders = functionScope.localPlaceholders; if (functionElement != null && functionElement.enclosingClass != null) { functionElement.enclosingClass.forEachMember( (enclosingClass, member) { memberIdentifiers.add(member.name); }); } Set<String> usedLocalIdentifiers = new Set<String>(); for (LocalPlaceholder placeholder in placeholders) { String nextId = _generator.generate(placeholder.identifier, (name) { return functionScope.parameterIdentifiers.contains(name) || _forbiddenIdentifiers.contains(name) || usedLocalIdentifiers.contains(name) || memberIdentifiers.contains(name); }); usedLocalIdentifiers.add(nextId); _renameNodes(placeholder.nodes, (_) => nextId); } }); // Do not rename members to top-levels, that allows to avoid renaming // members to constructors. placeholderCollector.memberPlaceholders.forEach((identifier, nodes) { String newIdentifier = _generateMemberName(identifier); _renameNodes(nodes, (_) => newIdentifier); }); } /// Finds renamings for all the placeholders in [placeholderCollector] and /// stores them in [renames]. /// Also adds to [platformImports] all the platform-libraries that are used. void computeRenames(PlaceholderCollector placeholderCollector) { _allNamedParameterIdentifiers = new Set<String>(); for (FunctionScope functionScope in placeholderCollector.functionScopes.values) { _allNamedParameterIdentifiers.addAll(functionScope.parameterIdentifiers); } _forbiddenIdentifiers = new Set<String>.from(fixedDynamicNames); _forbiddenIdentifiers.addAll(fixedStaticNames); _forbiddenIdentifiers.addAll(Keyword.keywords.keys); _forbiddenIdentifiers.add('main'); if (enableMinification) { _computeMinifiedRenames(placeholderCollector); } else { _computeNonMinifiedRenames(placeholderCollector); } // Rename constructors. for (ConstructorPlaceholder placeholder in placeholderCollector.constructorPlaceholders) { renames[placeholder.node] = _renameConstructor(placeholder); }; // Rename private identifiers uniquely for each library. placeholderCollector.privateNodes.forEach( (LibraryElement library, Set<Identifier> identifiers) { for (Identifier identifier in identifiers) { renames[identifier] = _getPrivateName(library, identifier.source); } }); // Rename unresolved nodes, to make sure they still do not resolve. for (Node node in placeholderCollector.unresolvedNodes) { renames[node] = _generateUniqueTopLevelName('Unresolved'); } // Erase prefixes that are now not needed. for (Node node in placeholderCollector.prefixNodesToErase) { renames[node] = ''; } if (cutDeclarationTypes) { for (DeclarationTypePlaceholder placeholder in placeholderCollector.declarationTypePlaceholders) { renames[placeholder.typeNode] = placeholder.requiresVar ? 'var' : ''; } } } } /** * Generates mini ID based on index. * In other words, it converts index to visual representation * as if digits are given characters. */ String generateMiniId(int index) { const String firstCharAlphabet = r'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'; const String otherCharsAlphabet = r'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_$'; // It's like converting index in decimal to [chars] radix. if (index < firstCharAlphabet.length) return firstCharAlphabet[index]; StringBuffer resultBuilder = new StringBuffer(); resultBuilder.writeCharCode( firstCharAlphabet.codeUnitAt(index % firstCharAlphabet.length)); index ~/= firstCharAlphabet.length; int length = otherCharsAlphabet.length; while (index >= length) { resultBuilder.writeCharCode(otherCharsAlphabet.codeUnitAt(index % length)); index ~/= length; } resultBuilder.write(otherCharsAlphabet[index]); return resultBuilder.toString(); } abstract class Generator { String generate(String originalName, bool isForbidden(String name)); } /// Always tries to return original identifier name unless it is forbidden. class ConservativeGenerator implements Generator { String generate(String originalName, bool isForbidden(String name)) { String result = originalName; int index = 0; while (isForbidden(result) ){ //|| result == originalName) { result = '${originalName}_${generateMiniId(index++)}'; } return result; } } /// Always tries to generate the most compact identifier. class MinifyingGenerator implements Generator { int index = 0; MinifyingGenerator(); String generate(String originalName, bool isForbidden(String name)) { String result; do { result = generateMiniId(index++); } while (isForbidden(result)); return result; } }