pkg/front_end/tool/kernel_ast_file_rewriter.dart - sdk.git - Git at Google

 // Copyright (c) 2020, 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.

 import "dart:io" show File, Platform, stdout;
 import "dart:typed_data" show Uint8List;

 import 'package:_fe_analyzer_shared/src/parser/parser.dart'
     show IdentifierContext;

 import 'package:_fe_analyzer_shared/src/scanner/token.dart'
     show CommentToken, Token;

 import "package:front_end/src/fasta/util/parser_ast.dart";

 import 'package:front_end/src/fasta/util/parser_ast_helper.dart';

 void main(List<String> args) {
   Uri uri = Platform.script;
   uri = uri.resolve("../../kernel/lib/ast.dart");
   Uint8List bytes = new File.fromUri(uri).readAsBytesSync();
   CompilationUnitEnd ast =
       getAST(bytes, includeBody: true, includeComments: true);
   Map<String, TopLevelDeclarationEnd> classes = {};
   for (TopLevelDeclarationEnd cls in ast.getClasses()) {
     IdentifierHandle identifier = cls.getIdentifier();
     assert(classes[identifier.token] == null);
     classes[identifier.token.toString()] = cls;
   }

   Set<String?> goodNames = {"TreeNode"};
   Map<Token, Replacement> replacements = {};
   for (MapEntry<String, TopLevelDeclarationEnd> entry in classes.entries) {
     TopLevelDeclarationEnd cls = entry.value;

     // Simple "class hierarchy" to only work on TreeNodes.
     if (goodNames.contains(entry.key)) {
       // Cached good.
     } else {
       // Check if good.
       String? parent = getExtends(cls);
       TopLevelDeclarationEnd? parentCls = classes[parent];
       List<String?> allParents = [parent];
       while (
           parent != null && parentCls != null && !goodNames.contains(parent)) {
         parent = getExtends(parentCls);
         allParents.add(parent);
         parentCls = classes[parent];
       }
       if (goodNames.contains(parent)) {
         goodNames.addAll(allParents);
       } else {
         continue;
       }
     }

     ClassDeclarationEnd classDeclaration = cls.getClassDeclaration();
     ClassOrMixinOrExtensionBodyEnd classOrMixinBody =
         classDeclaration.getClassOrMixinOrExtensionBody();

     Set<String> namedClassConstructors = {};
     Set<String> namedFields = {};
     for (MemberEnd member in classOrMixinBody.getMembers()) {
       if (member.isClassConstructor()) {
         ClassConstructorEnd constructor = member.getClassConstructor();
         Token nameToken = constructor.beginToken;
         // String name = nameToken.lexeme;
         if (nameToken.next!.lexeme == ".") {
           nameToken = nameToken.next!.next!;
           // name += ".$nameToken";
           namedClassConstructors.add(nameToken.lexeme);
         }
         if (nameToken.next!.lexeme == ".") {
           throw "Unexpected";
         }
       } else if (member.isClassFields()) {
         ClassFieldsEnd classFields = member.getClassFields();
         Token identifierToken = classFields.getFieldIdentifiers().single.token;
         String identifier = identifierToken.toString();
         namedFields.add(identifier);
       }
     }

     // If there isn't a `frozen` field in `TreeNode` we insert one.
     if (entry.key == "TreeNode" && !namedFields.contains("frozen")) {
       Token classBraceToken = classOrMixinBody.beginToken;
       assert(classBraceToken.lexeme == "{");
       replacements[classBraceToken] = new Replacement(
           classBraceToken, classBraceToken, "{\n  bool frozen = false;");
     }

     for (MemberEnd member in classOrMixinBody.getMembers()) {
       if (member.isClassConstructor()) {
         processConstructor(
             member, replacements, namedClassConstructors, namedFields);
       } else if (member.isClassFields()) {
         processField(member, entry, replacements);
       }
     }
   }
   Token? token = ast.getBegin().token;

   int endOfLast = token.end;
   while (token != null) {
     CommentToken? comment = token.precedingComments;
     while (comment != null) {
       if (comment.offset > endOfLast) {
         for (int i = endOfLast; i < comment.offset; i++) {
           int byte = bytes[i];
           stdout.writeCharCode(byte);
         }
       }

       stdout.write(comment.value());
       endOfLast = comment.end;
       comment = comment.next as CommentToken?;
     }

     if (token.isEof) break;
     if (token.offset > endOfLast) {
       for (int i = endOfLast; i < token.offset; i++) {
         int byte = bytes[i];
         stdout.writeCharCode(byte);
       }
     }

     Replacement? replacement = replacements[token];
     if (replacement != null) {
       stdout.write(replacement.replacement);
       token = replacement.endToken;
     } else {
       stdout.write(token.lexeme);
     }
     endOfLast = token.end;
     token = token.next;
   }
 }

 void processField(
     MemberEnd member,
     MapEntry<String, TopLevelDeclarationEnd> entry,
     Map<Token, Replacement> replacements) {
   ClassFieldsEnd classFields = member.getClassFields();

   if (classFields.count != 1) {
     throw "Notice ${classFields.count}";
   }

   Token identifierToken = classFields.getFieldIdentifiers().single.token;
   String identifier = identifierToken.toString();

   if (identifier == "frozen" && entry.key == "TreeNode") return;

   if (classFields.staticToken != null) {
     return;
   }
   bool isFinal = false;
   if (classFields.varFinalOrConst?.toString() == "final") {
     isFinal = true;
   }

   TypeHandle? type = classFields.getFirstType();
   String typeString = "dynamic";
   if (type != null) {
     Token token = type.beginToken;
     typeString = "";
     while (token != identifierToken) {
       typeString += " ${token.lexeme}";
       token = token.next!;
     }
     typeString = typeString.trim();
   }

   FieldInitializerEnd? initializer = classFields.getFieldInitializer();
   String initializerString = "";
   if (initializer != null) {
     Token token = initializer.assignment;
     Token endToken = initializer.token;
     while (token != endToken) {
       initializerString += " ${token.lexeme}";
       token = token.next!;
     }
     initializerString = initializerString.trim();
   }

   Token beginToken = classFields.beginToken;
   Token endToken = classFields.endToken;
   // ignore: unnecessary_null_comparison
   assert(beginToken != null);
   // ignore: unnecessary_null_comparison
   assert(endToken != null);

   String frozenCheckCode =
       """if (frozen) throw "Trying to modify frozen node!";""";

   if (identifier == "parent" && entry.key == "TreeNode") {
     // We update the parent for libraries for instance all the time (e.g.
     // when we link).
     frozenCheckCode = "";
   } else if (identifier == "transformerFlags" && entry.key == "Member") {
     // The verifier changes this for all libraries
     // (and then change it back again).
     frozenCheckCode = "";
   } else if (identifier == "initializer" && entry.key == "Field") {
     // The constant evaluator does some stuff here. Only allow that
     // when it's basically a no-op though!
     frozenCheckCode = """
     if (frozen) {
       if (_initializer is ConstantExpression && newValue is ConstantExpression) {
         if ((_initializer as ConstantExpression).constant == newValue.constant) {
           _initializer = newValue;
           return;
         }
       }
       throw "Trying to modify frozen node!";
     }""";
   }

   if (!isFinal) {
     replacements[beginToken] = new Replacement(beginToken, endToken, """
 $typeString _$identifier$initializerString;
 $typeString get $identifier => _$identifier;
 void set $identifier($typeString newValue) {
     $frozenCheckCode
   _$identifier = newValue;
 }""");
   } else {
     // Don't create setter for final field.
     // TODO: Possibly wrap a list for instance of a non-writable one.
     replacements[beginToken] = new Replacement(beginToken, endToken, """
 final $typeString _$identifier$initializerString;
 $typeString get $identifier => _$identifier;""");
   }
 }

 void processConstructor(MemberEnd member, Map<Token, Replacement> replacements,
     Set<String> namedClassConstructors, Set<String> namedFields) {
   ClassConstructorEnd constructor = member.getClassConstructor();
   FormalParametersEnd formalParameters = constructor.getFormalParameters();
   List<FormalParameterEnd> parameters = formalParameters.getFormalParameters();

   for (FormalParameterEnd parameter in parameters) {
     Token token = parameter.getBegin().token;
     if (token.lexeme != "this") {
       continue;
     }
     // Here `this.foo` can just be replace with `this._foo`.
     Token afterDot = token.next!.next!;
     replacements[afterDot] = new Replacement(afterDot, afterDot, "_$afterDot");
   }

   OptionalFormalParametersEnd? optionalFormalParameters =
       formalParameters.getOptionalFormalParameters();
   Set<String> addInitializers = {};
   if (optionalFormalParameters != null) {
     List<FormalParameterEnd> parameters =
         optionalFormalParameters.getFormalParameters();

     for (FormalParameterEnd parameter in parameters) {
       Token token = parameter.getBegin().token;
       if (token.lexeme != "this") {
         continue;
       }
       // Here `this.foo` can't just be replace with `this._foo` as it is
       // (possibly) named and we can't use private stuff in named.
       // Instead we replace it with `dynamic foo` here and add an
       // initializer `this._foo = foo`.
       Token afterDot = token.next!.next!;
       addInitializers.add(afterDot.lexeme);
       replacements[token] = new Replacement(token, token.next!, "dynamic ");
     }
   }

   InitializersEnd? initializers = constructor.getInitializers();

   // First patch up any existing initializers.
   if (initializers != null) {
     List<InitializerEnd> actualInitializers = initializers.getInitializers();
     for (InitializerEnd initializer in actualInitializers) {
       Token token = initializer.getBegin().token;
       // This is only afterDot if there's a dot --- which (probably) is
       // only there if there's a `this`.
       Token afterDot = token.next!.next!;

       // We need to check it's not a redirecting call!
       // TODO(jensj): Handle redirects like this:
       //  class C {
       //    C();
       //    C.redirect() : this();
       //  }
       if (token.lexeme == "this" &&
           namedClassConstructors.contains(afterDot.lexeme)) {
         // Redirect!
         continue;
       }

       if (token.lexeme == "this") {
         // Here `this.foo` can just be replace with `this._foo`.
         assert(namedFields.contains(afterDot.lexeme));
         replacements[afterDot] =
             new Replacement(afterDot, afterDot, "_$afterDot");
       } else if (token.lexeme == "super") {
         // Don't try to patch this one.
       } else if (token.lexeme == "assert") {
         List<IdentifierHandle> identifiers =
             initializer.recursivelyFind<IdentifierHandle>();
         for (Token token in identifiers.map((e) => e.token)) {
           if (namedFields.contains(token.lexeme)) {
             replacements[token] = new Replacement(token, token, "_$token");
           }
         }
       } else {
         assert(namedFields.contains(token.lexeme),
             "${token.lexeme} isn't a known field among ${namedFields}");
         replacements[token] = new Replacement(token, token, "_$token");
       }
     }
   }

   // Then add any new ones.
   if (addInitializers.isNotEmpty && initializers == null) {
     // No initializers => Fake one by inserting `:` and all `_foo = foo`
     // entries.
     Token endToken = formalParameters.endToken;
     String initializerString =
         addInitializers.map((e) => "this._$e = $e").join(",\n");
     replacements[endToken] =
         new Replacement(endToken, endToken, ") : $initializerString");
   } else if (addInitializers.isNotEmpty) {
     // Add to existing initializer list. We add them as the first one(s)
     // so we don't have to insert before the potential super call.
     InitializersBegin firstOne = initializers!.getBegin();
     Token colon = firstOne.token;
     assert(colon.lexeme == ":");
     String initializerString =
         addInitializers.map((e) => "this._$e = $e").join(", ");
     replacements[colon] =
         new Replacement(colon, colon, ": $initializerString,");
   }

   // If there are anything in addInitializers we need to patch
   // up the body too -- if we replace `{this.foo}` with `{dynamic foo}`
   // and the body says `foo = 42;` before that would change the field,
   // now it will change the parameter value. We must patch up all usages
   // - even reads to work on things like
   //  class C {
   //    int field1;
   //    int field2;
   //    C(this.field1) : field2 = field1 + 1;
   //  }
   if (addInitializers.isNotEmpty) {
     BlockFunctionBodyEnd? blockFunctionBody =
         constructor.getBlockFunctionBody();
     if (blockFunctionBody != null) {
       List<IdentifierHandle> identifiers =
           blockFunctionBody.recursivelyFind<IdentifierHandle>();
       for (IdentifierHandle identifier in identifiers) {
         Token token = identifier.token;
         IdentifierContext context = identifier.context;
         if (namedFields.contains(token.lexeme) &&
             addInitializers.contains(token.lexeme)) {
           // For now naively assume that if it's a continuation it says
           // `this.`
           if (!context.isContinuation) {
             replacements[token] = new Replacement(token, token, "_$token");
           }
         }
       }
     }
   }
 }

 class Replacement {
   final Token beginToken;
   final Token endToken;
   final String replacement;

   Replacement(this.beginToken, this.endToken, this.replacement);
 }

 String? getExtends(TopLevelDeclarationEnd cls) {
   ClassDeclarationEnd classDeclaration = cls.getClassDeclaration();

   ClassExtendsHandle classExtends = classDeclaration.getClassExtends();
   Token? extendsKeyword = classExtends.extendsKeyword;
   if (extendsKeyword == null) {
     return null;
   } else {
     return extendsKeyword.next.toString();
   }
 }

 void debugDumpNode(ParserAstNode node) {
   node.children!.forEach((element) {
     print("${element.what} (${element.deprecatedArguments}) "
         "(${element.children})");
   });
 }

 void debugDumpNodeRecursively(ParserAstNode node, {String indent = ""}) {
   print("$indent${node.what} (${node.deprecatedArguments})");
   if (node.children == null) return;
   node.children!.forEach((element) {
     print("$indent${element.what} (${element.deprecatedArguments})");
     if (element.children != null) {
       element.children!.forEach((element) {
         debugDumpNodeRecursively(element, indent: "  $indent");
       });
     }
   });
 }
	// Copyright (c) 2020, 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.

	import "dart:io" show File, Platform, stdout;
	import "dart:typed_data" show Uint8List;

	import 'package:_fe_analyzer_shared/src/parser/parser.dart'
	show IdentifierContext;

	import 'package:_fe_analyzer_shared/src/scanner/token.dart'
	show CommentToken, Token;

	import "package:front_end/src/fasta/util/parser_ast.dart";

	import 'package:front_end/src/fasta/util/parser_ast_helper.dart';

	void main(List<String> args) {
	Uri uri = Platform.script;
	uri = uri.resolve("../../kernel/lib/ast.dart");
	Uint8List bytes = new File.fromUri(uri).readAsBytesSync();
	CompilationUnitEnd ast =
	getAST(bytes, includeBody: true, includeComments: true);
	Map<String, TopLevelDeclarationEnd> classes = {};
	for (TopLevelDeclarationEnd cls in ast.getClasses()) {
	IdentifierHandle identifier = cls.getIdentifier();
	assert(classes[identifier.token] == null);
	classes[identifier.token.toString()] = cls;
	}

	Set<String?> goodNames = {"TreeNode"};
	Map<Token, Replacement> replacements = {};
	for (MapEntry<String, TopLevelDeclarationEnd> entry in classes.entries) {
	TopLevelDeclarationEnd cls = entry.value;

	// Simple "class hierarchy" to only work on TreeNodes.
	if (goodNames.contains(entry.key)) {
	// Cached good.
	} else {
	// Check if good.
	String? parent = getExtends(cls);
	TopLevelDeclarationEnd? parentCls = classes[parent];
	List<String?> allParents = [parent];
	while (
	parent != null && parentCls != null && !goodNames.contains(parent)) {
	parent = getExtends(parentCls);
	allParents.add(parent);
	parentCls = classes[parent];
	}
	if (goodNames.contains(parent)) {
	goodNames.addAll(allParents);
	} else {
	continue;
	}
	}

	ClassDeclarationEnd classDeclaration = cls.getClassDeclaration();
	ClassOrMixinOrExtensionBodyEnd classOrMixinBody =
	classDeclaration.getClassOrMixinOrExtensionBody();

	Set<String> namedClassConstructors = {};
	Set<String> namedFields = {};
	for (MemberEnd member in classOrMixinBody.getMembers()) {
	if (member.isClassConstructor()) {
	ClassConstructorEnd constructor = member.getClassConstructor();
	Token nameToken = constructor.beginToken;
	// String name = nameToken.lexeme;
	if (nameToken.next!.lexeme == ".") {
	nameToken = nameToken.next!.next!;
	// name += ".$nameToken";
	namedClassConstructors.add(nameToken.lexeme);
	}
	if (nameToken.next!.lexeme == ".") {
	throw "Unexpected";
	}
	} else if (member.isClassFields()) {
	ClassFieldsEnd classFields = member.getClassFields();
	Token identifierToken = classFields.getFieldIdentifiers().single.token;
	String identifier = identifierToken.toString();
	namedFields.add(identifier);
	}
	}

	// If there isn't a `frozen` field in `TreeNode` we insert one.
	if (entry.key == "TreeNode" && !namedFields.contains("frozen")) {
	Token classBraceToken = classOrMixinBody.beginToken;
	assert(classBraceToken.lexeme == "{");
	replacements[classBraceToken] = new Replacement(
	classBraceToken, classBraceToken, "{\n bool frozen = false;");
	}

	for (MemberEnd member in classOrMixinBody.getMembers()) {
	if (member.isClassConstructor()) {
	processConstructor(
	member, replacements, namedClassConstructors, namedFields);
	} else if (member.isClassFields()) {
	processField(member, entry, replacements);
	}
	}
	}
	Token? token = ast.getBegin().token;

	int endOfLast = token.end;
	while (token != null) {
	CommentToken? comment = token.precedingComments;
	while (comment != null) {
	if (comment.offset > endOfLast) {
	for (int i = endOfLast; i < comment.offset; i++) {
	int byte = bytes[i];
	stdout.writeCharCode(byte);
	}
	}

	stdout.write(comment.value());
	endOfLast = comment.end;
	comment = comment.next as CommentToken?;
	}

	if (token.isEof) break;
	if (token.offset > endOfLast) {
	for (int i = endOfLast; i < token.offset; i++) {
	int byte = bytes[i];
	stdout.writeCharCode(byte);
	}
	}

	Replacement? replacement = replacements[token];
	if (replacement != null) {
	stdout.write(replacement.replacement);
	token = replacement.endToken;
	} else {
	stdout.write(token.lexeme);
	}
	endOfLast = token.end;
	token = token.next;
	}
	}

	void processField(
	MemberEnd member,
	MapEntry<String, TopLevelDeclarationEnd> entry,
	Map<Token, Replacement> replacements) {
	ClassFieldsEnd classFields = member.getClassFields();

	if (classFields.count != 1) {
	throw "Notice ${classFields.count}";
	}

	Token identifierToken = classFields.getFieldIdentifiers().single.token;
	String identifier = identifierToken.toString();

	if (identifier == "frozen" && entry.key == "TreeNode") return;

	if (classFields.staticToken != null) {
	return;
	}
	bool isFinal = false;
	if (classFields.varFinalOrConst?.toString() == "final") {
	isFinal = true;
	}

	TypeHandle? type = classFields.getFirstType();
	String typeString = "dynamic";
	if (type != null) {
	Token token = type.beginToken;
	typeString = "";
	while (token != identifierToken) {
	typeString += " ${token.lexeme}";
	token = token.next!;
	}
	typeString = typeString.trim();
	}

	FieldInitializerEnd? initializer = classFields.getFieldInitializer();
	String initializerString = "";
	if (initializer != null) {
	Token token = initializer.assignment;
	Token endToken = initializer.token;
	while (token != endToken) {
	initializerString += " ${token.lexeme}";
	token = token.next!;
	}
	initializerString = initializerString.trim();
	}

	Token beginToken = classFields.beginToken;
	Token endToken = classFields.endToken;
	// ignore: unnecessary_null_comparison
	assert(beginToken != null);
	// ignore: unnecessary_null_comparison
	assert(endToken != null);

	String frozenCheckCode =
	"""if (frozen) throw "Trying to modify frozen node!";""";

	if (identifier == "parent" && entry.key == "TreeNode") {
	// We update the parent for libraries for instance all the time (e.g.
	// when we link).
	frozenCheckCode = "";
	} else if (identifier == "transformerFlags" && entry.key == "Member") {
	// The verifier changes this for all libraries
	// (and then change it back again).
	frozenCheckCode = "";
	} else if (identifier == "initializer" && entry.key == "Field") {
	// The constant evaluator does some stuff here. Only allow that
	// when it's basically a no-op though!
	frozenCheckCode = """
	if (frozen) {
	if (_initializer is ConstantExpression && newValue is ConstantExpression) {
	if ((_initializer as ConstantExpression).constant == newValue.constant) {
	_initializer = newValue;
	return;
	}
	}
	throw "Trying to modify frozen node!";
	}""";
	}

	if (!isFinal) {
	replacements[beginToken] = new Replacement(beginToken, endToken, """
	$typeString _$identifier$initializerString;
	$typeString get $identifier => _$identifier;
	void set $identifier($typeString newValue) {
	$frozenCheckCode
	_$identifier = newValue;
	}""");
	} else {
	// Don't create setter for final field.
	// TODO: Possibly wrap a list for instance of a non-writable one.
	replacements[beginToken] = new Replacement(beginToken, endToken, """
	final $typeString _$identifier$initializerString;
	$typeString get $identifier => _$identifier;""");
	}
	}

	void processConstructor(MemberEnd member, Map<Token, Replacement> replacements,
	Set<String> namedClassConstructors, Set<String> namedFields) {
	ClassConstructorEnd constructor = member.getClassConstructor();
	FormalParametersEnd formalParameters = constructor.getFormalParameters();
	List<FormalParameterEnd> parameters = formalParameters.getFormalParameters();

	for (FormalParameterEnd parameter in parameters) {
	Token token = parameter.getBegin().token;
	if (token.lexeme != "this") {
	continue;
	}
	// Here `this.foo` can just be replace with `this._foo`.
	Token afterDot = token.next!.next!;
	replacements[afterDot] = new Replacement(afterDot, afterDot, "_$afterDot");
	}

	OptionalFormalParametersEnd? optionalFormalParameters =
	formalParameters.getOptionalFormalParameters();
	Set<String> addInitializers = {};
	if (optionalFormalParameters != null) {
	List<FormalParameterEnd> parameters =
	optionalFormalParameters.getFormalParameters();

	for (FormalParameterEnd parameter in parameters) {
	Token token = parameter.getBegin().token;
	if (token.lexeme != "this") {
	continue;
	}
	// Here `this.foo` can't just be replace with `this._foo` as it is
	// (possibly) named and we can't use private stuff in named.
	// Instead we replace it with `dynamic foo` here and add an
	// initializer `this._foo = foo`.
	Token afterDot = token.next!.next!;
	addInitializers.add(afterDot.lexeme);
	replacements[token] = new Replacement(token, token.next!, "dynamic ");
	}
	}

	InitializersEnd? initializers = constructor.getInitializers();

	// First patch up any existing initializers.
	if (initializers != null) {
	List<InitializerEnd> actualInitializers = initializers.getInitializers();
	for (InitializerEnd initializer in actualInitializers) {
	Token token = initializer.getBegin().token;
	// This is only afterDot if there's a dot --- which (probably) is
	// only there if there's a `this`.
	Token afterDot = token.next!.next!;

	// We need to check it's not a redirecting call!
	// TODO(jensj): Handle redirects like this:
	// class C {
	// C();
	// C.redirect() : this();
	// }
	if (token.lexeme == "this" &&
	namedClassConstructors.contains(afterDot.lexeme)) {
	// Redirect!
	continue;
	}

	if (token.lexeme == "this") {
	// Here `this.foo` can just be replace with `this._foo`.
	assert(namedFields.contains(afterDot.lexeme));
	replacements[afterDot] =
	new Replacement(afterDot, afterDot, "_$afterDot");
	} else if (token.lexeme == "super") {
	// Don't try to patch this one.
	} else if (token.lexeme == "assert") {
	List<IdentifierHandle> identifiers =
	initializer.recursivelyFind<IdentifierHandle>();
	for (Token token in identifiers.map((e) => e.token)) {
	if (namedFields.contains(token.lexeme)) {
	replacements[token] = new Replacement(token, token, "_$token");
	}
	}
	} else {
	assert(namedFields.contains(token.lexeme),
	"${token.lexeme} isn't a known field among ${namedFields}");
	replacements[token] = new Replacement(token, token, "_$token");
	}
	}
	}

	// Then add any new ones.
	if (addInitializers.isNotEmpty && initializers == null) {
	// No initializers => Fake one by inserting `:` and all `_foo = foo`
	// entries.
	Token endToken = formalParameters.endToken;
	String initializerString =
	addInitializers.map((e) => "this._$e = $e").join(",\n");
	replacements[endToken] =
	new Replacement(endToken, endToken, ") : $initializerString");
	} else if (addInitializers.isNotEmpty) {
	// Add to existing initializer list. We add them as the first one(s)
	// so we don't have to insert before the potential super call.
	InitializersBegin firstOne = initializers!.getBegin();
	Token colon = firstOne.token;
	assert(colon.lexeme == ":");
	String initializerString =
	addInitializers.map((e) => "this._$e = $e").join(", ");
	replacements[colon] =
	new Replacement(colon, colon, ": $initializerString,");
	}

	// If there are anything in addInitializers we need to patch
	// up the body too -- if we replace `{this.foo}` with `{dynamic foo}`
	// and the body says `foo = 42;` before that would change the field,
	// now it will change the parameter value. We must patch up all usages
	// - even reads to work on things like
	// class C {
	// int field1;
	// int field2;
	// C(this.field1) : field2 = field1 + 1;
	// }
	if (addInitializers.isNotEmpty) {
	BlockFunctionBodyEnd? blockFunctionBody =
	constructor.getBlockFunctionBody();
	if (blockFunctionBody != null) {
	List<IdentifierHandle> identifiers =
	blockFunctionBody.recursivelyFind<IdentifierHandle>();
	for (IdentifierHandle identifier in identifiers) {
	Token token = identifier.token;
	IdentifierContext context = identifier.context;
	if (namedFields.contains(token.lexeme) &&
	addInitializers.contains(token.lexeme)) {
	// For now naively assume that if it's a continuation it says
	// `this.`
	if (!context.isContinuation) {
	replacements[token] = new Replacement(token, token, "_$token");
	}
	}
	}
	}
	}
	}

	class Replacement {
	final Token beginToken;
	final Token endToken;
	final String replacement;

	Replacement(this.beginToken, this.endToken, this.replacement);
	}

	String? getExtends(TopLevelDeclarationEnd cls) {
	ClassDeclarationEnd classDeclaration = cls.getClassDeclaration();

	ClassExtendsHandle classExtends = classDeclaration.getClassExtends();
	Token? extendsKeyword = classExtends.extendsKeyword;
	if (extendsKeyword == null) {
	return null;
	} else {
	return extendsKeyword.next.toString();
	}
	}

	void debugDumpNode(ParserAstNode node) {
	node.children!.forEach((element) {
	print("${element.what} (${element.deprecatedArguments}) "
	"(${element.children})");
	});
	}

	void debugDumpNodeRecursively(ParserAstNode node, {String indent = ""}) {
	print("$indent${node.what} (${node.deprecatedArguments})");
	if (node.children == null) return;
	node.children!.forEach((element) {
	print("$indent${element.what} (${element.deprecatedArguments})");
	if (element.children != null) {
	element.children!.forEach((element) {
	debugDumpNodeRecursively(element, indent: " $indent");
	});
	}
	});
	}