Linter Demo

Errors: 1

Warnings: 37

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

// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file // for details. All rights reserved. Use of this source code is governed by a // BSD-style license that can be found in the LICENSE file. library dart2js.mirrors_used; import 'constants/expressions.dart'; import 'constants/values.dart' show ConstantValue, ConstructedConstantValue, ListConstantValue, StringConstantValue, TypeConstantValue; import 'dart_types.dart' show DartType, InterfaceType, TypeKind; import 'dart2jslib.dart' show Compiler, CompilerTask, ConstantCompiler, MessageKind, TreeElements, invariant; import 'elements/elements.dart' show ClassElement, Element, LibraryElement, MetadataAnnotation, ScopeContainerElement, VariableElement; import 'tree/tree.dart' show Import, LibraryTag, NamedArgument, NewExpression, Node; import 'util/util.dart' show Link, Spannable; /** * Compiler task that analyzes MirrorsUsed annotations. * * When importing 'dart:mirrors', it is possible to annotate the import with * MirrorsUsed annotation. This is a way to declare what elements will be * reflected on at runtime. Such elements, even they would normally be * discarded by the implicit tree-shaking algorithm must be preserved in the * final output. * * Since some libraries cannot tell exactly what they will be reflecting on, it * is possible for one library to specify a MirrorsUsed annotation that applies * to another library. For example: * * Mirror utility library that cannot tell what it is reflecting on: * library mirror_utils; * import 'dart:mirrors'; * ... * * The main app which knows how it use the mirror utility library: * library main_app; * @MirrorsUsed(override='mirror_utils') * import 'dart:mirrors'; * import 'mirror_utils.dart'; * ... * * In this case, we say that @MirrorsUsed in main_app overrides @MirrorsUsed in * mirror_utils. * * It is possible to override all libraries using override='*'. If multiple * catch-all overrides like this, they are merged together. * * It is possible for library "a" to declare that it overrides library "b", and * vice versa. In this case, both annotations will be discarded and the * compiler will emit a hint (that is, a warning that is not specified by the * language specification). * * After applying all the overrides, we can iterate over libraries that import * 'dart:mirrors'. If a library does not have an associated MirrorsUsed * annotation, then we have to discard all MirrorsUsed annotations and assume * everything can be reflected on. * * On the other hand, if all libraries importing dart:mirrors have a * MirrorsUsed annotation, these annotations are merged. * * MERGING MIRRORSUSED * * TBD. */ class MirrorUsageAnalyzerTask extends CompilerTask { Set<LibraryElement> librariesWithUsage; MirrorUsageAnalyzer analyzer; MirrorUsageAnalyzerTask(Compiler compiler) : super(compiler) { analyzer = new MirrorUsageAnalyzer(compiler, this); } /// Collect @MirrorsUsed annotations in all libraries. Called by the /// compiler after all libraries are loaded, but before resolution. void analyzeUsage(LibraryElement mainApp) { if (mainApp == null || compiler.mirrorsLibrary == null) return; measure(analyzer.run); List<String> symbols = analyzer.mergedMirrorUsage.symbols; List<Element> targets = analyzer.mergedMirrorUsage.targets; List<Element> metaTargets = analyzer.mergedMirrorUsage.metaTargets; compiler.backend.registerMirrorUsage( symbols == null ? null : new Set<String>.from(symbols), targets == null ? null : new Set<Element>.from(targets), metaTargets == null ? null : new Set<Element>.from(metaTargets)); librariesWithUsage = analyzer.librariesWithUsage; } /// Is there a @MirrorsUsed annotation in the library of [element]? Used by /// the resolver to suppress hints about using new Symbol or /// MirrorSystem.getName. bool hasMirrorUsage(Element element) { LibraryElement library = element.library; // Internal libraries always have implicit mirror usage. return library.isInternalLibrary || (librariesWithUsage != null && librariesWithUsage.contains(library)); } /// Call-back from the resolver to analyze MirorsUsed annotations. The result /// is stored in [analyzer] and later used to compute /// [:analyzer.mergedMirrorUsage:]. void validate(NewExpression node, TreeElements mapping) { for (Node argument in node.send.arguments) { NamedArgument named = argument.asNamedArgument(); if (named == null) continue; ConstantCompiler constantCompiler = compiler.resolver.constantCompiler; ConstantValue value = constantCompiler.compileNode(named.expression, mapping).value; MirrorUsageBuilder builder = new MirrorUsageBuilder( analyzer, mapping.analyzedElement.library, named.expression, value, mapping); if (named.name.source == 'symbols') { analyzer.cachedStrings[value] = builder.convertConstantToUsageList(value, onlyStrings: true); } else if (named.name.source == 'targets') { analyzer.cachedElements[value] = builder.resolveUsageList(builder.convertConstantToUsageList(value)); } else if (named.name.source == 'metaTargets') { analyzer.cachedElements[value] = builder.resolveUsageList(builder.convertConstantToUsageList(value)); } else if (named.name.source == 'override') { analyzer.cachedElements[value] = builder.resolveUsageList(builder.convertConstantToUsageList(value)); } } } } class MirrorUsageAnalyzer { final Compiler compiler; final MirrorUsageAnalyzerTask task; List<LibraryElement> wildcard; final Set<LibraryElement> librariesWithUsage; final Map<ConstantValue, List<String>> cachedStrings; final Map<ConstantValue, List<Element>> cachedElements; MirrorUsage mergedMirrorUsage; MirrorUsageAnalyzer(Compiler compiler, this.task) : compiler = compiler, librariesWithUsage = new Set<LibraryElement>(), cachedStrings = new Map<ConstantValue, List<String>>(), cachedElements = new Map<ConstantValue, List<Element>>(); /// Collect and merge all @MirrorsUsed annotations. As a side-effect, also /// compute which libraries have the annotation (which is used by /// [MirrorUsageAnalyzerTask.hasMirrorUsage]). void run() { wildcard = compiler.libraryLoader.libraries.toList(); Map<LibraryElement, List<MirrorUsage>> usageMap = collectMirrorsUsedAnnotation(); propagateOverrides(usageMap); Set<LibraryElement> librariesWithoutUsage = new Set<LibraryElement>(); usageMap.forEach((LibraryElement library, List<MirrorUsage> usage) { if (usage.isEmpty) librariesWithoutUsage.add(library); }); if (librariesWithoutUsage.isEmpty) { mergedMirrorUsage = mergeUsages(usageMap); } else { mergedMirrorUsage = new MirrorUsage(null, null, null, null); } } /// Collect all @MirrorsUsed from all libraries and represent them as /// [MirrorUsage]. Map<LibraryElement, List<MirrorUsage>> collectMirrorsUsedAnnotation() { Map<LibraryElement, List<MirrorUsage>> result = new Map<LibraryElement, List<MirrorUsage>>(); for (LibraryElement library in compiler.libraryLoader.libraries) { if (library.isInternalLibrary) continue; for (LibraryTag tag in library.tags) { Import importTag = tag.asImport(); if (importTag == null) continue; compiler.withCurrentElement(library, () { List<MirrorUsage> usages = mirrorsUsedOnLibraryTag(library, importTag); if (usages != null) { List<MirrorUsage> existing = result[library]; if (existing != null) { existing.addAll(usages); } else { result[library] = usages; } } }); } } return result; } /// Apply [MirrorUsage] with 'override' to libraries they override. void propagateOverrides(Map<LibraryElement, List<MirrorUsage>> usageMap) { Map<LibraryElement, List<MirrorUsage>> propagatedOverrides = new Map<LibraryElement, List<MirrorUsage>>(); usageMap.forEach((LibraryElement library, List<MirrorUsage> usages) { for (MirrorUsage usage in usages) { List<Element> override = usage.override; if (override == null) continue; if (override == wildcard) { for (LibraryElement overridden in wildcard) { if (overridden != library) { List<MirrorUsage> overriddenUsages = propagatedOverrides .putIfAbsent(overridden, () => <MirrorUsage>[]); overriddenUsages.add(usage); } } } else { for (Element overridden in override) { List<MirrorUsage> overriddenUsages = propagatedOverrides .putIfAbsent(overridden, () => <MirrorUsage>[]); overriddenUsages.add(usage); } } } }); propagatedOverrides.forEach((LibraryElement overridden, List<MirrorUsage> overriddenUsages) { List<MirrorUsage> usages = usageMap.putIfAbsent(overridden, () => <MirrorUsage>[]); usages.addAll(overriddenUsages); }); } /// Find @MirrorsUsed annotations on the given import [tag] in [library]. The /// annotations are represented as [MirrorUsage]. List<MirrorUsage> mirrorsUsedOnLibraryTag(LibraryElement library, Import tag) { LibraryElement importedLibrary = library.getLibraryFromTag(tag); if (importedLibrary != compiler.mirrorsLibrary) { return null; } List<MirrorUsage> result = <MirrorUsage>[]; for (MetadataAnnotation metadata in tag.metadata) { metadata.ensureResolved(compiler); Element element = metadata.constant.value.getType(compiler.coreTypes).element; if (element == compiler.mirrorsUsedClass) { result.add(buildUsage(metadata.constant.value)); } } return result; } /// Merge all [MirrorUsage] instances accross all libraries. MirrorUsage mergeUsages(Map<LibraryElement, List<MirrorUsage>> usageMap) { Set<MirrorUsage> usagesToMerge = new Set<MirrorUsage>(); usageMap.forEach((LibraryElement library, List<MirrorUsage> usages) { librariesWithUsage.add(library); usagesToMerge.addAll(usages); }); if (usagesToMerge.isEmpty) { return new MirrorUsage(null, wildcard, null, null); } else { MirrorUsage result = new MirrorUsage(null, null, null, null); for (MirrorUsage usage in usagesToMerge) { result = merge(result, usage); } return result; } } /// Merge [a] with [b]. The resulting [MirrorUsage] simply has the symbols, /// targets, and metaTargets of [a] and [b] concatenated. 'override' is /// ignored. MirrorUsage merge(MirrorUsage a, MirrorUsage b) { // TOOO(ahe): Should be an instance method on MirrorUsage. if (a.symbols == null && a.targets == null && a.metaTargets == null) { return b; } else if ( b.symbols == null && b.targets == null && b.metaTargets == null) { return a; } // TODO(ahe): Test the following cases. List<String> symbols = a.symbols; if (symbols == null) { symbols = b.symbols; } else if (b.symbols != null) { symbols.addAll(b.symbols); } List<Element> targets = a.targets; if (targets == null) { targets = b.targets; } else if (targets != wildcard && b.targets != null) { targets.addAll(b.targets); } List<Element> metaTargets = a.metaTargets; if (metaTargets == null) { metaTargets = b.metaTargets; } else if (metaTargets != wildcard && b.metaTargets != null) { metaTargets.addAll(b.metaTargets); } return new MirrorUsage(symbols, targets, metaTargets, null); } /// Convert a [constant] to an instance of [MirrorUsage] using information /// that was resolved during [MirrorUsageAnalyzerTask.validate]. MirrorUsage buildUsage(ConstructedConstantValue constant) { Map<Element, ConstantValue> fields = constant.fieldElements; VariableElement symbolsField = compiler.mirrorsUsedClass.lookupLocalMember( 'symbols'); VariableElement targetsField = compiler.mirrorsUsedClass.lookupLocalMember( 'targets'); VariableElement metaTargetsField = compiler.mirrorsUsedClass.lookupLocalMember( 'metaTargets'); VariableElement overrideField = compiler.mirrorsUsedClass.lookupLocalMember( 'override'); return new MirrorUsage( cachedStrings[fields[symbolsField]], cachedElements[fields[targetsField]], cachedElements[fields[metaTargetsField]], cachedElements[fields[overrideField]]); } } /// Used to represent a resolved MirrorsUsed constant. class MirrorUsage { final List<String> symbols; final List<Element> targets; final List<Element> metaTargets; final List<Element> override; MirrorUsage(this.symbols, this.targets, this.metaTargets, this.override); String toString() { return 'MirrorUsage(' 'symbols = $symbols, ' 'targets = $targets, ' 'metaTargets = $metaTargets, ' 'override = $override' ')'; } } class MirrorUsageBuilder { final MirrorUsageAnalyzer analyzer; final LibraryElement enclosingLibrary; final Spannable spannable; final ConstantValue constant; final TreeElements elements; MirrorUsageBuilder( this.analyzer, this.enclosingLibrary, this.spannable, this.constant, this.elements); Compiler get compiler => analyzer.compiler; /// Convert a constant to a list of [String] and [Type] values. If the /// constant is a single [String], it is assumed to be a comma-separated list /// of qualified names. If the constant is a [Type] t, the result is [:[t]:]. /// Otherwise, the constant is assumed to represent a list of strings (each a /// qualified name) and types, and such a list is constructed. If /// [onlyStrings] is true, the returned list is a [:List<String>:] and any /// [Type] values are treated as an error (meaning that the value is ignored /// and a hint is emitted). List convertConstantToUsageList( ConstantValue constant, { bool onlyStrings: false }) { if (constant.isNull) { return null; } else if (constant.isList) { ListConstantValue list = constant; List result = onlyStrings ? <String> [] : []; for (ConstantValue entry in list.entries) { if (entry.isString) { StringConstantValue string = entry; result.add(string.primitiveValue.slowToString()); } else if (!onlyStrings && entry.isType) { TypeConstantValue type = entry; result.add(type.representedType); } else { Spannable node = positionOf(entry); MessageKind kind = onlyStrings ? MessageKind.MIRRORS_EXPECTED_STRING : MessageKind.MIRRORS_EXPECTED_STRING_OR_TYPE; compiler.reportHint( node, kind, {'name': node, 'type': apiTypeOf(entry)}); } } return result; } else if (!onlyStrings && constant.isType) { TypeConstantValue type = constant; return [type.representedType]; } else if (constant.isString) { StringConstantValue string = constant; var iterable = string.primitiveValue.slowToString().split(',').map((e) => e.trim()); return onlyStrings ? new List<String>.from(iterable) : iterable.toList(); } else { Spannable node = positionOf(constant); MessageKind kind = onlyStrings ? MessageKind.MIRRORS_EXPECTED_STRING_OR_LIST : MessageKind.MIRRORS_EXPECTED_STRING_TYPE_OR_LIST; compiler.reportHint( node, kind, {'name': node, 'type': apiTypeOf(constant)}); return null; } } /// Find the first non-implementation interface of constant. DartType apiTypeOf(ConstantValue constant) { DartType type = constant.getType(compiler.coreTypes); LibraryElement library = type.element.library; if (type.isInterfaceType && library.isInternalLibrary) { InterfaceType interface = type; ClassElement cls = type.element; cls.ensureResolved(compiler); for (DartType supertype in cls.allSupertypes) { if (supertype.isInterfaceType && !supertype.element.library.isInternalLibrary) { return interface.asInstanceOf(supertype.element); } } } return type; } /// Convert a list of strings and types to a list of elements. Types are /// converted to their corresponding element, and strings are resolved as /// follows: /// /// First find the longest library name that is a prefix of the string, if /// there are none, resolve using [resolveExpression]. Otherwise, resolve the /// rest of the string using [resolveLocalExpression]. List<Element> resolveUsageList(List list) { if (list == null) return null; if (list.length == 1 && list[0] == '*') { return analyzer.wildcard; } List<Element> result = <Element>[]; for (var entry in list) { if (entry is DartType) { DartType type = entry; result.add(type.element); } else { String string = entry; LibraryElement libraryCandiate; String libraryNameCandiate; for (LibraryElement l in compiler.libraryLoader.libraries) { if (l.hasLibraryName()) { String libraryName = l.getLibraryOrScriptName(); if (string == libraryName) { // Found an exact match. libraryCandiate = l; libraryNameCandiate = libraryName; break; } else if (string.startsWith('$libraryName.')) { if (libraryNameCandiate == null || libraryNameCandiate.length < libraryName.length) { // Found a better candiate libraryCandiate = l; libraryNameCandiate = libraryName; } } } } Element e; if (libraryNameCandiate == string) { e = libraryCandiate; } else if (libraryNameCandiate != null) { e = resolveLocalExpression( libraryCandiate, string.substring(libraryNameCandiate.length + 1).split('.')); } else { e = resolveExpression(string); } if (e != null) result.add(e); } } return result; } /// Resolve [expression] in [enclosingLibrary]'s import scope. Element resolveExpression(String expression) { List<String> identifiers = expression.split('.'); Element element = enclosingLibrary.find(identifiers[0]); if (element == null) { compiler.reportHint( spannable, MessageKind.MIRRORS_CANNOT_RESOLVE_IN_CURRENT_LIBRARY, {'name': expression}); return null; } else { if (identifiers.length == 1) return element; return resolveLocalExpression(element, identifiers.sublist(1)); } } /// Resolve [identifiers] in [element]'s local members. Element resolveLocalExpression(Element element, List<String> identifiers) { Element current = element; for (String identifier in identifiers) { Element e = findLocalMemberIn(current, identifier); if (e == null) { if (current.isLibrary) { LibraryElement library = current; compiler.reportHint( spannable, MessageKind.MIRRORS_CANNOT_RESOLVE_IN_LIBRARY, {'name': identifiers[0], 'library': library.getLibraryOrScriptName()}); } else { compiler.reportHint( spannable, MessageKind.MIRRORS_CANNOT_FIND_IN_ELEMENT, {'name': identifier, 'element': current.name}); } return current; } current = e; } return current; } /// Helper method to lookup members in a [ScopeContainerElement]. If /// [element] is not a ScopeContainerElement, return null. Element findLocalMemberIn(Element element, String name) { if (element is ScopeContainerElement) { ScopeContainerElement scope = element; if (element.isClass) { ClassElement cls = element; cls.ensureResolved(compiler); } return scope.localLookup(name); } return null; } /// Attempt to find a [Spannable] corresponding to constant. Spannable positionOf(ConstantValue constant) { Node node; elements.forEachConstantNode((Node n, ConstantExpression c) { if (node == null && c.value == constant) { node = n; } }); if (node == null) { // TODO(ahe): Returning [spannable] here leads to confusing error // messages. For example, consider: // @MirrorsUsed(targets: fisk) // import 'dart:mirrors'; // // const fisk = const [main]; // // main() {} // // The message is: // example.dart:1:23: Hint: Can't use 'fisk' here because ... // Did you forget to add quotes? // @MirrorsUsed(targets: fisk) // ^^^^ // // Instead of saying 'fisk' should pretty print the problematic constant // value. return spannable; } return node; } }