pkg/kernel/lib/transformations/mixin_full_resolution.dart - sdk - Git at Google

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 library kernel.transformations.mixin_full_resolution;

 import '../ast.dart';
 import '../class_hierarchy.dart';
 import '../clone.dart';
 import '../core_types.dart';
 import '../target/targets.dart' show Target;
 import '../type_algebra.dart';

 void transformLibraries(Target targetInfo, CoreTypes coreTypes,
     ClassHierarchy hierarchy, List<Library> libraries,
     {bool doSuperResolution: true}) {
   new MixinFullResolution(targetInfo, coreTypes, hierarchy,
           doSuperResolution: doSuperResolution)
       .transform(libraries);
 }

 /// Replaces all mixin applications with regular classes, cloning all fields
 /// and procedures from the mixed-in class, cloning all constructors from the
 /// base class.
 ///
 /// When [doSuperResolution] constructor parameter is [true], super calls
 /// (as well as super initializer invocations) are also resolved to their
 /// targets in this pass.
 class MixinFullResolution {
   final Target targetInfo;
   final CoreTypes coreTypes;

   /// The [ClassHierarchy] that should be used after applying this transformer.
   /// If any class was updated, in general we need to create a new
   /// [ClassHierarchy] instance, with new dispatch targets; or at least let
   /// the existing instance know that some of its dispatch tables are not
   /// valid anymore.
   ClassHierarchy hierarchy;

   // This enables `super` resolution transformation, which is not compatible
   // with Dart VM's requirements around incremental compilation and has been
   // moved to Dart VM itself.
   final bool doSuperResolution;

   MixinFullResolution(this.targetInfo, this.coreTypes, this.hierarchy,
       {this.doSuperResolution: true});

   /// Transform the given new [libraries].  It is expected that all other
   /// libraries have already been transformed.
   void transform(List<Library> libraries) {
     if (libraries.isEmpty) return;

     var transformedClasses = new Set<Class>();

     // Desugar all mixin application classes by copying in fields/methods from
     // the mixin and constructors from the base class.
     var processedClasses = new Set<Class>();
     for (var library in libraries) {
       if (library.isExternal) continue;

       for (var class_ in library.classes) {
         transformClass(libraries, processedClasses, transformedClasses, class_);
       }
     }

     // We might need to update the class hierarchy.
     hierarchy =
         hierarchy.applyMemberChanges(transformedClasses, findDescendants: true);

     if (!doSuperResolution) {
       return;
     }
     // Resolve all super call expressions and super initializers.
     for (var library in libraries) {
       if (library.isExternal) continue;

       for (var class_ in library.classes) {
         for (var procedure in class_.procedures) {
           if (procedure.containsSuperCalls) {
             new SuperCallResolutionTransformer(
                     hierarchy, coreTypes, class_.superclass, targetInfo)
                 .visit(procedure);
           }
         }
       }
     }
   }

   transformClass(
       List<Library> librariesToBeTransformed,
       Set<Class> processedClasses,
       Set<Class> transformedClasses,
       Class class_) {
     // If this class was already handled then so were all classes up to the
     // [Object] class.
     if (!processedClasses.add(class_)) return;

     if (!librariesToBeTransformed.contains(class_.enclosingLibrary) &&
         class_.enclosingLibrary.importUri?.scheme == "dart") {
       // If we're not asked to transform the platform libraries then we expect
       // that they will be already transformed.
       return;
     }

     // Ensure super classes have been transformed before this class.
     if (class_.superclass != null &&
         class_.superclass.level.index >= ClassLevel.Mixin.index) {
       transformClass(librariesToBeTransformed, processedClasses,
           transformedClasses, class_.superclass);
     }

     // If this is not a mixin application we don't need to make forwarding
     // constructors in this class.
     if (!class_.isMixinApplication) return;
     assert(librariesToBeTransformed.contains(class_.enclosingLibrary));

     if (class_.mixedInClass.level.index < ClassLevel.Mixin.index) {
       throw new Exception(
           'Class "${class_.name}" mixes in "${class_.mixedInClass.name}" from'
           ' an external library.  Did you forget --link?');
     }

     transformedClasses.add(class_);

     // Clone fields and methods from the mixin class.
     var substitution = getSubstitutionMap(class_.mixedInType);
     var cloner = new CloneVisitor(typeSubstitution: substitution);

     // When we copy a field from the mixed in class, we remove any
     // forwarding-stub getters/setters from the superclass, but copy their
     // covariance-bits onto the new field.
     var nonSetters = <Name, Procedure>{};
     var setters = <Name, Procedure>{};
     for (var procedure in class_.procedures) {
       if (procedure.isSetter) {
         setters[procedure.name] = procedure;
       } else {
         nonSetters[procedure.name] = procedure;
       }
     }
     for (var field in class_.mixin.fields) {
       Field clone = cloner.clone(field);
       Procedure setter = setters[field.name];
       if (setter != null) {
         setters.remove(field.name);
         VariableDeclaration parameter =
             setter.function.positionalParameters.first;
         clone.isGenericCovariantImpl = parameter.isGenericCovariantImpl;
       }
       nonSetters.remove(field.name);
       class_.addMember(clone);
     }
     class_.procedures.clear();
     class_.procedures..addAll(nonSetters.values)..addAll(setters.values);

     // Existing procedures in the class should only be forwarding stubs.
     // Replace them with methods from the mixin class if they have the same
     // name, but keep their parameter flags.
     int originalLength = class_.procedures.length;
     outer:
     for (var procedure in class_.mixin.procedures) {
       // Forwarding stubs in the mixin class are used when calling through the
       // mixin class's interface, not when calling through the mixin
       // application.  They should not be copied.
       if (procedure.isForwardingStub) continue;

       // Factory constructors are not cloned.
       if (procedure.isFactory) continue;

       // NoSuchMethod forwarders aren't cloned.
       if (procedure.isNoSuchMethodForwarder) continue;

       Procedure clone = cloner.clone(procedure);
       // Linear search for a forwarding stub with the same name.
       for (int i = 0; i < originalLength; ++i) {
         var originalProcedure = class_.procedures[i];
         if (originalProcedure.name == clone.name &&
             originalProcedure.kind == clone.kind) {
           FunctionNode src = originalProcedure.function;
           FunctionNode dst = clone.function;

           if (src.positionalParameters.length !=
                   dst.positionalParameters.length ||
               src.namedParameters.length != dst.namedParameters.length) {
             // A compile time error has already occured, but don't crash below,
             // and don't add several procedures with the same name to the class.
             continue outer;
           }

           assert(src.typeParameters.length == dst.typeParameters.length);
           for (int j = 0; j < src.typeParameters.length; ++j) {
             dst.typeParameters[j].flags = src.typeParameters[i].flags;
           }
           for (int j = 0; j < src.positionalParameters.length; ++j) {
             dst.positionalParameters[j].flags =
                 src.positionalParameters[j].flags;
           }
           // TODO(kernel team): The named parameters are not sorted,
           // this might not be correct.
           for (int j = 0; j < src.namedParameters.length; ++j) {
             dst.namedParameters[j].flags = src.namedParameters[j].flags;
           }

           class_.procedures[i] = clone;
           continue outer;
         }
       }
       class_.addMember(clone);
     }
     assert(class_.constructors.isNotEmpty);

     // This class implements the mixin type. Also, backends rely on the fact
     // that eliminated mixin is appended into the end of interfaces list.
     class_.implementedTypes.add(class_.mixedInType);

     // This class is now a normal class.
     class_.mixedInType = null;

     // Leave breadcrumbs for backends (e.g. for dart:mirrors implementation).
     class_.isEliminatedMixin = true;
   }
 }

 class SuperCallResolutionTransformer extends Transformer {
   final ClassHierarchy hierarchy;
   final CoreTypes coreTypes;
   final Class lookupClass;
   final Target targetInfo;

   SuperCallResolutionTransformer(
       this.hierarchy, this.coreTypes, this.lookupClass, this.targetInfo);

   TreeNode visit(TreeNode node) => node.accept(this);

   visitSuperPropertyGet(SuperPropertyGet node) {
     Member target = hierarchy.getDispatchTarget(lookupClass, node.name);
     if (target != null) {
       return new DirectPropertyGet(new ThisExpression(), target)
         ..fileOffset = node.fileOffset;
     } else {
       return _callNoSuchMethod(node.name.name, new Arguments.empty(), node,
           isGetter: true, isSuper: true);
     }
   }

   visitSuperPropertySet(SuperPropertySet node) {
     Member target =
         hierarchy.getDispatchTarget(lookupClass, node.name, setter: true);
     if (target != null) {
       return new DirectPropertySet(
           new ThisExpression(), target, visit(node.value))
         ..fileOffset = node.fileOffset;
     } else {
       // Call has to return right-hand-side.
       VariableDeclaration rightHandSide =
           new VariableDeclaration.forValue(visit(node.value));
       Expression result = _callNoSuchMethod(
           node.name.name, new Arguments([new VariableGet(rightHandSide)]), node,
           isSetter: true, isSuper: true);
       VariableDeclaration call = new VariableDeclaration.forValue(result);
       return new Let(
           rightHandSide, new Let(call, new VariableGet(rightHandSide)));
     }
   }

   visitSuperMethodInvocation(SuperMethodInvocation node) {
     Member target = hierarchy.getDispatchTarget(lookupClass, node.name);
     Arguments visitedArguments = visit(node.arguments);
     if (target is Procedure &&
         !target.isAccessor &&
         _callIsLegal(target.function, visitedArguments)) {
       return new DirectMethodInvocation(
           new ThisExpression(), target, visitedArguments)
         ..fileOffset = node.fileOffset;
     } else if (target == null || (target is Procedure && !target.isAccessor)) {
       // Target not found at all, or call was illegal.
       return _callNoSuchMethod(node.name.name, visitedArguments, node,
           isSuper: true);
     } else {
       return new MethodInvocation(
           new DirectPropertyGet(new ThisExpression(), target),
           new Name('call'),
           visitedArguments)
         ..fileOffset = node.fileOffset;
     }
   }

   /// Create a call to no such method.
   Expression _callNoSuchMethod(
       String methodName, Arguments methodArguments, TreeNode node,
       {isSuper: false, isGetter: false, isSetter: false}) {
     Member noSuchMethod =
         hierarchy.getDispatchTarget(lookupClass, new Name("noSuchMethod"));
     String methodNameUsed = (isGetter)
         ? "get:$methodName"
         : (isSetter) ? "set:$methodName" : methodName;
     if (noSuchMethod != null &&
         noSuchMethod.function.positionalParameters.length == 1 &&
         noSuchMethod.function.namedParameters.isEmpty) {
       // We have a correct noSuchMethod method.
       ConstructorInvocation invocation = _createInvocation(
           methodNameUsed, methodArguments, isSuper, new ThisExpression());
       return new DirectMethodInvocation(
           new ThisExpression(), noSuchMethod, new Arguments([invocation]))
         ..fileOffset = node.fileOffset;
     } else {
       // Incorrect noSuchMethod method: Call noSuchMethod on Object
       // with Invocation of noSuchMethod as the method that did not exist.
       noSuchMethod = hierarchy.getDispatchTarget(
           coreTypes.objectClass, new Name("noSuchMethod"));
       ConstructorInvocation invocation = _createInvocation(
           methodNameUsed, methodArguments, isSuper, new ThisExpression());
       ConstructorInvocation invocationPrime = _createInvocation("noSuchMethod",
           new Arguments([invocation]), false, new ThisExpression());
       return new DirectMethodInvocation(
           new ThisExpression(), noSuchMethod, new Arguments([invocationPrime]))
         ..fileOffset = node.fileOffset;
     }
   }

   /// Creates an "new _InvocationMirror(...)" invocation.
   ConstructorInvocation _createInvocation(String methodName,
       Arguments callArguments, bool isSuperInvocation, Expression receiver) {
     return targetInfo.instantiateInvocation(
         coreTypes, receiver, methodName, callArguments, -1, isSuperInvocation);
   }

   /// Check that a call to the targetFunction is legal given the arguments.
   ///
   /// I.e. check that the number of positional parameters and the names of the
   /// given named parameters represents a valid call to the function.
   bool _callIsLegal(FunctionNode targetFunction, Arguments arguments) {
     if ((targetFunction.requiredParameterCount > arguments.positional.length) ||
         (targetFunction.positionalParameters.length <
             arguments.positional.length)) {
       // Given too few or too many positional arguments
       return false;
     }

     // Do we give named that we don't take?
     Set<String> givenNamed = arguments.named.map((v) => v.name).toSet();
     Set<String> takenNamed =
         targetFunction.namedParameters.map((v) => v.name).toSet();
     givenNamed.removeAll(takenNamed);
     return givenNamed.isEmpty;
   }
 }

 class SuperInitializerResolutionTransformer extends InitializerVisitor {
   final Class lookupClass;

   SuperInitializerResolutionTransformer(this.lookupClass);

   transformInitializers(List<Initializer> initializers) {
     for (var initializer in initializers) {
       initializer.accept(this);
     }
   }

   visitSuperInitializer(SuperInitializer node) {
     Constructor constructor = node.target;
     if (constructor.enclosingClass != lookupClass) {
       // If [node] refers to a constructor target which is not directly the
       // superclass but some indirect base class then this is because classes in
       // the middle are mixin applications.  These mixin applications will have
       // received a forwarding constructor which we are required to use instead.
       for (var replacement in lookupClass.constructors) {
         if (constructor.name == replacement.name) {
           node.target = replacement;
           return null;
         }
       }

       throw new Exception(
           'Could not find a generative constructor named "${constructor.name}" '
           'in lookup class "${lookupClass.name}"!');
     }
   }
 }
	// Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.
	library kernel.transformations.mixin_full_resolution;

	import '../ast.dart';
	import '../class_hierarchy.dart';
	import '../clone.dart';
	import '../core_types.dart';
	import '../target/targets.dart' show Target;
	import '../type_algebra.dart';

	void transformLibraries(Target targetInfo, CoreTypes coreTypes,
	ClassHierarchy hierarchy, List<Library> libraries,
	{bool doSuperResolution: true}) {
	new MixinFullResolution(targetInfo, coreTypes, hierarchy,
	doSuperResolution: doSuperResolution)
	.transform(libraries);
	}

	/// Replaces all mixin applications with regular classes, cloning all fields
	/// and procedures from the mixed-in class, cloning all constructors from the
	/// base class.
	///
	/// When [doSuperResolution] constructor parameter is [true], super calls
	/// (as well as super initializer invocations) are also resolved to their
	/// targets in this pass.
	class MixinFullResolution {
	final Target targetInfo;
	final CoreTypes coreTypes;

	/// The [ClassHierarchy] that should be used after applying this transformer.
	/// If any class was updated, in general we need to create a new
	/// [ClassHierarchy] instance, with new dispatch targets; or at least let
	/// the existing instance know that some of its dispatch tables are not
	/// valid anymore.
	ClassHierarchy hierarchy;

	// This enables `super` resolution transformation, which is not compatible
	// with Dart VM's requirements around incremental compilation and has been
	// moved to Dart VM itself.
	final bool doSuperResolution;

	MixinFullResolution(this.targetInfo, this.coreTypes, this.hierarchy,
	{this.doSuperResolution: true});

	/// Transform the given new [libraries]. It is expected that all other
	/// libraries have already been transformed.
	void transform(List<Library> libraries) {
	if (libraries.isEmpty) return;

	var transformedClasses = new Set<Class>();

	// Desugar all mixin application classes by copying in fields/methods from
	// the mixin and constructors from the base class.
	var processedClasses = new Set<Class>();
	for (var library in libraries) {
	if (library.isExternal) continue;

	for (var class_ in library.classes) {
	transformClass(libraries, processedClasses, transformedClasses, class_);
	}
	}

	// We might need to update the class hierarchy.
	hierarchy =
	hierarchy.applyMemberChanges(transformedClasses, findDescendants: true);

	if (!doSuperResolution) {
	return;
	}
	// Resolve all super call expressions and super initializers.
	for (var library in libraries) {
	if (library.isExternal) continue;

	for (var class_ in library.classes) {
	for (var procedure in class_.procedures) {
	if (procedure.containsSuperCalls) {
	new SuperCallResolutionTransformer(
	hierarchy, coreTypes, class_.superclass, targetInfo)
	.visit(procedure);
	}
	}
	}
	}
	}

	transformClass(
	List<Library> librariesToBeTransformed,
	Set<Class> processedClasses,
	Set<Class> transformedClasses,
	Class class_) {
	// If this class was already handled then so were all classes up to the
	// [Object] class.
	if (!processedClasses.add(class_)) return;

	if (!librariesToBeTransformed.contains(class_.enclosingLibrary) &&
	class_.enclosingLibrary.importUri?.scheme == "dart") {
	// If we're not asked to transform the platform libraries then we expect
	// that they will be already transformed.
	return;
	}

	// Ensure super classes have been transformed before this class.
	if (class_.superclass != null &&
	class_.superclass.level.index >= ClassLevel.Mixin.index) {
	transformClass(librariesToBeTransformed, processedClasses,
	transformedClasses, class_.superclass);
	}

	// If this is not a mixin application we don't need to make forwarding
	// constructors in this class.
	if (!class_.isMixinApplication) return;
	assert(librariesToBeTransformed.contains(class_.enclosingLibrary));

	if (class_.mixedInClass.level.index < ClassLevel.Mixin.index) {
	throw new Exception(
	'Class "${class_.name}" mixes in "${class_.mixedInClass.name}" from'
	' an external library. Did you forget --link?');
	}

	transformedClasses.add(class_);

	// Clone fields and methods from the mixin class.
	var substitution = getSubstitutionMap(class_.mixedInType);
	var cloner = new CloneVisitor(typeSubstitution: substitution);

	// When we copy a field from the mixed in class, we remove any
	// forwarding-stub getters/setters from the superclass, but copy their
	// covariance-bits onto the new field.
	var nonSetters = <Name, Procedure>{};
	var setters = <Name, Procedure>{};
	for (var procedure in class_.procedures) {
	if (procedure.isSetter) {
	setters[procedure.name] = procedure;
	} else {
	nonSetters[procedure.name] = procedure;
	}
	}
	for (var field in class_.mixin.fields) {
	Field clone = cloner.clone(field);
	Procedure setter = setters[field.name];
	if (setter != null) {
	setters.remove(field.name);
	VariableDeclaration parameter =
	setter.function.positionalParameters.first;
	clone.isGenericCovariantImpl = parameter.isGenericCovariantImpl;
	}
	nonSetters.remove(field.name);
	class_.addMember(clone);
	}
	class_.procedures.clear();
	class_.procedures..addAll(nonSetters.values)..addAll(setters.values);

	// Existing procedures in the class should only be forwarding stubs.
	// Replace them with methods from the mixin class if they have the same
	// name, but keep their parameter flags.
	int originalLength = class_.procedures.length;
	outer:
	for (var procedure in class_.mixin.procedures) {
	// Forwarding stubs in the mixin class are used when calling through the
	// mixin class's interface, not when calling through the mixin
	// application. They should not be copied.
	if (procedure.isForwardingStub) continue;

	// Factory constructors are not cloned.
	if (procedure.isFactory) continue;

	// NoSuchMethod forwarders aren't cloned.
	if (procedure.isNoSuchMethodForwarder) continue;

	Procedure clone = cloner.clone(procedure);
	// Linear search for a forwarding stub with the same name.
	for (int i = 0; i < originalLength; ++i) {
	var originalProcedure = class_.procedures[i];
	if (originalProcedure.name == clone.name &&
	originalProcedure.kind == clone.kind) {
	FunctionNode src = originalProcedure.function;
	FunctionNode dst = clone.function;

	if (src.positionalParameters.length !=
	dst.positionalParameters.length \|\|
	src.namedParameters.length != dst.namedParameters.length) {
	// A compile time error has already occured, but don't crash below,
	// and don't add several procedures with the same name to the class.
	continue outer;
	}

	assert(src.typeParameters.length == dst.typeParameters.length);
	for (int j = 0; j < src.typeParameters.length; ++j) {
	dst.typeParameters[j].flags = src.typeParameters[i].flags;
	}
	for (int j = 0; j < src.positionalParameters.length; ++j) {
	dst.positionalParameters[j].flags =
	src.positionalParameters[j].flags;
	}
	// TODO(kernel team): The named parameters are not sorted,
	// this might not be correct.
	for (int j = 0; j < src.namedParameters.length; ++j) {
	dst.namedParameters[j].flags = src.namedParameters[j].flags;
	}

	class_.procedures[i] = clone;
	continue outer;
	}
	}
	class_.addMember(clone);
	}
	assert(class_.constructors.isNotEmpty);

	// This class implements the mixin type. Also, backends rely on the fact
	// that eliminated mixin is appended into the end of interfaces list.
	class_.implementedTypes.add(class_.mixedInType);

	// This class is now a normal class.
	class_.mixedInType = null;

	// Leave breadcrumbs for backends (e.g. for dart:mirrors implementation).
	class_.isEliminatedMixin = true;
	}
	}

	class SuperCallResolutionTransformer extends Transformer {
	final ClassHierarchy hierarchy;
	final CoreTypes coreTypes;
	final Class lookupClass;
	final Target targetInfo;

	SuperCallResolutionTransformer(
	this.hierarchy, this.coreTypes, this.lookupClass, this.targetInfo);

	TreeNode visit(TreeNode node) => node.accept(this);

	visitSuperPropertyGet(SuperPropertyGet node) {
	Member target = hierarchy.getDispatchTarget(lookupClass, node.name);
	if (target != null) {
	return new DirectPropertyGet(new ThisExpression(), target)
	..fileOffset = node.fileOffset;
	} else {
	return _callNoSuchMethod(node.name.name, new Arguments.empty(), node,
	isGetter: true, isSuper: true);
	}
	}

	visitSuperPropertySet(SuperPropertySet node) {
	Member target =
	hierarchy.getDispatchTarget(lookupClass, node.name, setter: true);
	if (target != null) {
	return new DirectPropertySet(
	new ThisExpression(), target, visit(node.value))
	..fileOffset = node.fileOffset;
	} else {
	// Call has to return right-hand-side.
	VariableDeclaration rightHandSide =
	new VariableDeclaration.forValue(visit(node.value));
	Expression result = _callNoSuchMethod(
	node.name.name, new Arguments([new VariableGet(rightHandSide)]), node,
	isSetter: true, isSuper: true);
	VariableDeclaration call = new VariableDeclaration.forValue(result);
	return new Let(
	rightHandSide, new Let(call, new VariableGet(rightHandSide)));
	}
	}

	visitSuperMethodInvocation(SuperMethodInvocation node) {
	Member target = hierarchy.getDispatchTarget(lookupClass, node.name);
	Arguments visitedArguments = visit(node.arguments);
	if (target is Procedure &&
	!target.isAccessor &&
	_callIsLegal(target.function, visitedArguments)) {
	return new DirectMethodInvocation(
	new ThisExpression(), target, visitedArguments)
	..fileOffset = node.fileOffset;
	} else if (target == null \|\| (target is Procedure && !target.isAccessor)) {
	// Target not found at all, or call was illegal.
	return _callNoSuchMethod(node.name.name, visitedArguments, node,
	isSuper: true);
	} else {
	return new MethodInvocation(
	new DirectPropertyGet(new ThisExpression(), target),
	new Name('call'),
	visitedArguments)
	..fileOffset = node.fileOffset;
	}
	}

	/// Create a call to no such method.
	Expression _callNoSuchMethod(
	String methodName, Arguments methodArguments, TreeNode node,
	{isSuper: false, isGetter: false, isSetter: false}) {
	Member noSuchMethod =
	hierarchy.getDispatchTarget(lookupClass, new Name("noSuchMethod"));
	String methodNameUsed = (isGetter)
	? "get:$methodName"
	: (isSetter) ? "set:$methodName" : methodName;
	if (noSuchMethod != null &&
	noSuchMethod.function.positionalParameters.length == 1 &&
	noSuchMethod.function.namedParameters.isEmpty) {
	// We have a correct noSuchMethod method.
	ConstructorInvocation invocation = _createInvocation(
	methodNameUsed, methodArguments, isSuper, new ThisExpression());
	return new DirectMethodInvocation(
	new ThisExpression(), noSuchMethod, new Arguments([invocation]))
	..fileOffset = node.fileOffset;
	} else {
	// Incorrect noSuchMethod method: Call noSuchMethod on Object
	// with Invocation of noSuchMethod as the method that did not exist.
	noSuchMethod = hierarchy.getDispatchTarget(
	coreTypes.objectClass, new Name("noSuchMethod"));
	ConstructorInvocation invocation = _createInvocation(
	methodNameUsed, methodArguments, isSuper, new ThisExpression());
	ConstructorInvocation invocationPrime = _createInvocation("noSuchMethod",
	new Arguments([invocation]), false, new ThisExpression());
	return new DirectMethodInvocation(
	new ThisExpression(), noSuchMethod, new Arguments([invocationPrime]))
	..fileOffset = node.fileOffset;
	}
	}

	/// Creates an "new _InvocationMirror(...)" invocation.
	ConstructorInvocation _createInvocation(String methodName,
	Arguments callArguments, bool isSuperInvocation, Expression receiver) {
	return targetInfo.instantiateInvocation(
	coreTypes, receiver, methodName, callArguments, -1, isSuperInvocation);
	}

	/// Check that a call to the targetFunction is legal given the arguments.
	///
	/// I.e. check that the number of positional parameters and the names of the
	/// given named parameters represents a valid call to the function.
	bool _callIsLegal(FunctionNode targetFunction, Arguments arguments) {
	if ((targetFunction.requiredParameterCount > arguments.positional.length) \|\|
	(targetFunction.positionalParameters.length <
	arguments.positional.length)) {
	// Given too few or too many positional arguments
	return false;
	}

	// Do we give named that we don't take?
	Set<String> givenNamed = arguments.named.map((v) => v.name).toSet();
	Set<String> takenNamed =
	targetFunction.namedParameters.map((v) => v.name).toSet();
	givenNamed.removeAll(takenNamed);
	return givenNamed.isEmpty;
	}
	}

	class SuperInitializerResolutionTransformer extends InitializerVisitor {
	final Class lookupClass;

	SuperInitializerResolutionTransformer(this.lookupClass);

	transformInitializers(List<Initializer> initializers) {
	for (var initializer in initializers) {
	initializer.accept(this);
	}
	}

	visitSuperInitializer(SuperInitializer node) {
	Constructor constructor = node.target;
	if (constructor.enclosingClass != lookupClass) {
	// If [node] refers to a constructor target which is not directly the
	// superclass but some indirect base class then this is because classes in
	// the middle are mixin applications. These mixin applications will have
	// received a forwarding constructor which we are required to use instead.
	for (var replacement in lookupClass.constructors) {
	if (constructor.name == replacement.name) {
	node.target = replacement;
	return null;
	}
	}

	throw new Exception(
	'Could not find a generative constructor named "${constructor.name}" '
	'in lookup class "${lookupClass.name}"!');
	}
	}
	}