Linter Demo

Errors: 1

Warnings: 18

File: /home/fstrocco/Dart/dart/benchmark/devcompiler/lib/src/codegen/reify_coercions.dart

// Copyright (c) 2015, 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 dev_compiler.src.codegen.reify_coercions; import 'package:analyzer/analyzer.dart' as analyzer; import 'package:analyzer/src/generated/ast.dart'; import 'package:analyzer/src/generated/element.dart'; import 'package:logging/logging.dart' as logger; import 'package:dev_compiler/devc.dart' show AbstractCompiler; import 'package:dev_compiler/src/checker/rules.dart'; import 'package:dev_compiler/src/info.dart'; import 'ast_builder.dart'; final _log = new logger.Logger('dev_compiler.reify_coercions'); // TODO(leafp) Factor this out or use an existing library class Tuple2<T0, T1> { final T0 e0; final T1 e1; Tuple2(this.e0, this.e1); } typedef T Function1<S, T>(S _); class NewTypeIdDesc { /// If null, then this is not a library level identifier (i.e. it's /// a type parameter, or a special type like void, dynamic, etc) LibraryElement importedFrom; /// True => use/def in same library bool fromCurrent; /// True => not a source variable bool synthetic; NewTypeIdDesc({this.fromCurrent, this.importedFrom, this.synthetic}); } class _Inference extends DownwardsInference { TypeManager _tm; _Inference(TypeRules rules, this._tm) : super(rules); @override void annotateCastFromDynamic(Expression e, DartType t) { var cast = Coercion.cast(e.staticType, t); var info = new DynamicCast(rules, e, cast); CoercionInfo.set(e, info); } @override void annotateListLiteral(ListLiteral e, List<DartType> targs) { var tNames = targs.map(_tm.typeNameFromDartType).toList(); e.typeArguments = AstBuilder.typeArgumentList(tNames); var listT = rules.provider.listType.substitute4(targs); e.staticType = listT; } @override void annotateMapLiteral(MapLiteral e, List<DartType> targs) { var tNames = targs.map(_tm.typeNameFromDartType).toList(); e.typeArguments = AstBuilder.typeArgumentList(tNames); var mapT = rules.provider.mapType.substitute4(targs); e.staticType = mapT; } @override void annotateInstanceCreationExpression( InstanceCreationExpression e, List<DartType> targs) { var tNames = targs.map(_tm.typeNameFromDartType).toList(); var cName = e.constructorName; var id = cName.type.name; var typeName = AstBuilder.typeName(id, tNames); cName.type = typeName; var newType = (e.staticType.element as ClassElement).type.substitute4(targs); e.staticType = newType; typeName.type = newType; } @override void annotateFunctionExpression(FunctionExpression e, DartType returnType) { // Implicitly changes e.staticType (e.element as ExecutableElementImpl).returnType = returnType; } } // This class implements a pass which modifies (in place) the ast replacing // abstract coercion nodes with their dart implementations. class CoercionReifier extends analyzer.GeneralizingAstVisitor<Object> { final CoercionManager _cm; final TypeManager _tm; final VariableManager _vm; final LibraryUnit _library; final _Inference _inferrer; CoercionReifier._( this._cm, this._tm, this._vm, this._library, this._inferrer); factory CoercionReifier(LibraryUnit library, AbstractCompiler compiler) { var vm = new VariableManager(); var tm = new TypeManager(library.library.element.enclosingElement, vm); var cm = new CoercionManager(vm, tm); var inferrer = new _Inference(compiler.rules, tm); return new CoercionReifier._(cm, tm, vm, library, inferrer); } // This should be the entry point for this class. Entering via the // visit functions directly may not do the right thing with respect // to discharging the collected definitions. // Returns the set of new type identifiers added by the reifier Map<Identifier, NewTypeIdDesc> reify() { _library.partsThenLibrary.forEach(generateUnit); return _tm.addedTypes; } void generateUnit(CompilationUnit unit) { visitCompilationUnit(unit); } @override Object visitExpression(Expression node) { var info = CoercionInfo.get(node); if (info is InferredTypeBase) { return _visitInferredTypeBase(info); } else if (info is DownCast) { return _visitDownCast(info); } return super.visitExpression(node); } ///////////////// Private ////////////////////////////////// Object _visitInferredTypeBase(InferredTypeBase node) { var expr = node.node; var success = _inferrer.inferExpression(expr, node.type, <String>[]); assert(success); expr.visitChildren(this); return null; } Object _visitDownCast(DownCast node) { var expr = node.node; var parent = expr.parent; expr.visitChildren(this); Expression newE = _cm.coerceExpression(expr, node.cast); if (!identical(expr, newE)) { var replaced = parent.accept(new NodeReplacer(expr, newE)); // It looks like NodeReplacer will always return true. // It does throw IllegalArgumentException though, if child is not found. assert(replaced); } return null; } Object visitCompilationUnit(CompilationUnit unit) { _cm.enterCompilationUnit(unit); Object ret = super.visitCompilationUnit(unit); _cm.exitCompilationUnit(unit); return ret; } } // This provides a placeholder variable manager. Currently it simply // mangles names in a way unlikely (but not guaranteed) to avoid // collisions with user variables. // TODO(leafp): Replace this with something real. class VariableManager { // TODO(leafp): Hack, not for real. int _id = 0; SimpleIdentifier freshIdentifier(String hint) { String n = _id.toString(); _id++; String s = "__$hint$n"; return AstBuilder.identifierFromString(s); } SimpleIdentifier freshTypeIdentifier(String hint) { return freshIdentifier(hint); } } // This class manages the reification of coercions as dart code. Given a // coercion c and an expression e it will produce an expression e' which // is the result of coercing e using c. class CoercionManager { VariableManager _vm; TypeManager _tm; CoercionManager(this._vm, this._tm); // Call on entry to and exit from a compilation unit in order to properly // discharge the accumulated wrappers. void enterCompilationUnit(CompilationUnit unit) { _tm.enterCompilationUnit(unit); } void exitCompilationUnit(CompilationUnit unit) { _tm.exitCompilationUnit(unit); } // The main entry point. Coerce e using c, returning a new expression, // possibly recording additional coercions functions and typedefs to // be discharged at a higher level. Expression coerceExpression(Expression e, Coercion c) { assert(c != null); assert(c is! CoercionError); if (e is NamedExpression) { Expression inner = coerceExpression(e.expression, c); return new NamedExpression(e.name, inner); } if (c is Cast) return _castExpression(e, c); assert(c is Identity); return e; } ///////////////// Private ////////////////////////////////// Expression _castExpression(Expression e, Cast c) { var ttName = _tm.typeNameFromDartType(c.toType); var cast = AstBuilder.asExpression(e, ttName); cast.staticType = c.toType; return cast; } } // A class for managing the interaction between the DartType hierarchy // and the AST type representation. It provides utilities to translate // a DartType to AST. In order to do so, it maintains a map of typedefs // naming otherwise un-named types. These must be discharged at the top // level of the compilation unit in order to produce well-formed dart code. // Note that in order to hoist the typedefs out of parameterized classes // we must close over any type variables. class TypeManager { final VariableManager _vm; final LibraryElement _currentLibrary; final Map<Identifier, NewTypeIdDesc> addedTypes = {}; CompilationUnitElement _currentUnit; /// A map containing new function typedefs to be introduced at the top level /// This uses LinkedHashMap to emit code in a consistent order. final Map<FunctionType, FunctionTypeAlias> _typedefs = {}; TypeManager(this._currentLibrary, this._vm); void enterCompilationUnit(CompilationUnit unit) { _currentUnit = unit.element; } void exitCompilationUnit(CompilationUnit unit) { unit.declarations.addAll(_typedefs.values); _typedefs.clear(); } TypeName typeNameFromDartType(DartType dType) { return _typeNameFromDartType(dType); } NormalFormalParameter typedFormal(Identifier v, DartType type) { return _typedFormal(v, type); } ///////////////// Private ////////////////////////////////// List<TypeParameterType> _freeTypeVariables(DartType type) { var s = new Set<TypeParameterType>(); void _ft(DartType type) { void _ftMap(Map<String, DartType> m) { if (m == null) return; for (var k in m.keys) _ft(m[k]); } void _ftList(List<DartType> l) { if (l == null) return; for (int i = 0; i < l.length; i++) _ft(l[i]); } if (type == null) return; if (type.isDynamic) return; if (type.isBottom) return; if (type.isObject) return; if (type is TypeParameterType) { s.add(type); return; } if (type is ParameterizedType) { if (type.name != null && type.name != "") { _ftList(type.typeArguments); return; } if (type is FunctionType) { _ftMap(type.namedParameterTypes); _ftList(type.normalParameterTypes); _ftList(type.optionalParameterTypes); _ft(type.returnType); return; } assert(type is! InterfaceType); assert(false); } if (type is VoidType) return; print(type.toString()); assert(false); } _ft(type); return s.toList(); } List<FormalParameter> _formalParameterListForFunctionType(FunctionType type) { var namedParameters = type.namedParameterTypes; var normalParameters = type.normalParameterTypes; var optionalParameters = type.optionalParameterTypes; var params = new List<FormalParameter>(); for (int i = 0; i < normalParameters.length; i++) { FormalParameter fp = AstBuilder.requiredFormal(_anonymousFormal(normalParameters[i])); _resolveFormal(fp, normalParameters[i]); params.add(fp); } for (int i = 0; i < optionalParameters.length; i++) { FormalParameter fp = AstBuilder.optionalFormal(_anonymousFormal(optionalParameters[i])); _resolveFormal(fp, optionalParameters[i]); params.add(fp); } for (String k in namedParameters.keys) { FormalParameter fp = AstBuilder.namedFormal(_anonymousFormal(namedParameters[k])); _resolveFormal(fp, namedParameters[k]); params.add(fp); } return params; } void _resolveFormal(FormalParameter fp, DartType type) { ParameterElementImpl fe = new ParameterElementImpl.forNode(fp.identifier); fe.parameterKind = fp.kind; fe.type = type; fp.identifier.staticElement = fe; fp.identifier.staticType = type; } FormalParameter _functionTypedFormal(Identifier v, FunctionType type) { assert(v != null); var params = _formalParameterListForFunctionType(type); var ret = typeNameFromDartType(type.returnType); return AstBuilder.functionTypedFormal(ret, v, params); } NormalFormalParameter _anonymousFormal(DartType type) { Identifier u = _vm.freshIdentifier("u"); return _typedFormal(u, type); } NormalFormalParameter _typedFormal(Identifier v, DartType type) { if (type is FunctionType) { return _functionTypedFormal(v, type); } assert(type.name != null); TypeName t = typeNameFromDartType(type); return AstBuilder.simpleFormal(v, t); } SimpleIdentifier freshTypeDefVariable(String hint) { var t = _vm.freshTypeIdentifier(hint); var desc = new NewTypeIdDesc( fromCurrent: true, importedFrom: _currentLibrary, synthetic: true); addedTypes[t] = desc; return t; } SimpleIdentifier typeParameterFromString(String name) => AstBuilder.identifierFromString(name); SimpleIdentifier freshReferenceToNamedType(DartType type) { var name = type.name; assert(name != null); var id = AstBuilder.identifierFromString(name); var element = type.element; id.staticElement = element; var library = null; // This can happen for types like (e.g.) void if (element != null) library = element.library; var desc = new NewTypeIdDesc( fromCurrent: _currentLibrary == library, importedFrom: library, synthetic: false); addedTypes[id] = desc; return id; } FunctionTypeAlias _newResolvedTypedef( FunctionType type, List<TypeParameterType> ftvs) { // The name of the typedef (unresolved at this point) // TODO(leafp): better naming. SimpleIdentifier t = freshTypeDefVariable("CastType"); // The element for the new typedef var element = new FunctionTypeAliasElementImpl(t.name, 0); // Fresh type parameter identifiers for the free type variables List<Identifier> tNames = ftvs.map((x) => typeParameterFromString(x.name)).toList(); // The type parameters themselves List<TypeParameter> tps = tNames.map(AstBuilder.typeParameter).toList(); // Allocate the elements for the type parameters, fill in their // type (which makes no sense) and link up the various elements // For each type parameter identifier, make an element and a type // with that element, link the two together, set the identifier element // to that element, and the identifier type to that type. List<TypeParameterElement> tElements = tNames.map((x) { var element = new TypeParameterElementImpl(x.name, 0); var type = new TypeParameterTypeImpl(element); element.type = type; x.staticElement = element; x.staticType = type; return element; }).toList(); // Get the types out from the elements List<TypeParameterType> tTypes = tElements.map((x) => x.type).toList(); // Take the return type from the original type, and replace the free // type variables with the fresh type variables element.returnType = type.returnType.substitute2(tTypes, ftvs); // Set the type parameter elements element.typeParameters = tElements; // Set the parent element to the current compilation unit element.enclosingElement = _currentUnit; // This is the type corresponding to the typedef. Note that // almost all methods on this type delegate to the element, so it // cannot be safely be used for anything until the element is fully resolved FunctionTypeImpl substType = new FunctionTypeImpl.con2(element); element.type = substType; // Link the type and the element into the identifier for the typedef t.staticType = substType; t.staticElement = element; // Make the formal parameters for the typedef, using the original type // with the fresh type variables substituted in. List<FormalParameter> fps = _formalParameterListForFunctionType(type.substitute2(tTypes, ftvs)); // Get the static elements out of the parameters, and use them to // initialize the parameters in the element model element.parameters = fps.map((x) => x.identifier.staticElement).toList(); // Build the return type syntax TypeName ret = _typeNameFromDartType(substType.returnType); // This should now be fully resolved (or at least enough so for things // to work so far). FunctionTypeAlias alias = AstBuilder.functionTypeAlias(ret, t, tps, fps); return alias; } // I think we can avoid alpha-varying type parameters, since // the binding forms are so limited, so we just re-use the // the original names for the formals and the actuals. TypeName _typeNameFromFunctionType(FunctionType type) { if (_typedefs.containsKey(type)) { var alias = _typedefs[type]; var ts = null; var tpl = alias.typeParameters; if (tpl != null) { var ltp = tpl.typeParameters; ts = new List<TypeName>.from( ltp.map((t) => _mkNewTypeName(null, t.name, null))); } var name = alias.name; return _mkNewTypeName(type, name, ts); } List<TypeParameterType> ftvs = _freeTypeVariables(type); FunctionTypeAlias alias = _newResolvedTypedef(type, ftvs); _typedefs[type] = alias; List<TypeName> args = ftvs.map(_typeNameFromDartType).toList(); TypeName namedType = _mkNewTypeName(alias.name.staticType, alias.name, args); return namedType; } TypeName _typeNameFromDartType(DartType dType) { String name = dType.name; if (name == null || name == "" || dType.isBottom) { if (dType is FunctionType) return _typeNameFromFunctionType(dType); _log.severe("No name for type, casting through dynamic"); var d = AstBuilder.identifierFromString("dynamic"); var t = _mkNewTypeName(dType, d, null); return t; } SimpleIdentifier id = freshReferenceToNamedType(dType); List<TypeName> args = null; if (dType is ParameterizedType) { List<DartType> targs = dType.typeArguments; args = targs.map(_typeNameFromDartType).toList(); } var t = _mkNewTypeName(dType, id, args); return t; } TypeName _mkNewTypeName(DartType type, Identifier id, List<TypeName> args) { var t = AstBuilder.typeName(id, args); t.type = type; return t; } }