Tweak public APIs and use them in patch_sdk, dart2js, and kernel-service

pkg/kernel/lib/binary/ast_from_binary.dart

 // 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.ast_from_binary;
 
 import 'dart:convert';
 import 'dart:typed_data';
 
 import '../ast.dart';
 import '../transformations/flags.dart';
@@ skipping 139 matching lines @@
   List<Expression> readAnnotationList(TreeNode parent) {
     int length = readUInt();
     if (length == 0) return const <Expression>[];
     List<Expression> list = new List<Expression>(length);
     for (int i = 0; i < length; ++i) {
       list[i] = readExpression()..parent = parent;
     }
     return list;
   }
 
-  void _fillTreeNodeList(
-      List<TreeNode> list, TreeNode buildObject(), TreeNode parent) {
-    list.length = readUInt();
-    for (int i = 0; i < list.length; ++i) {
-      list[i] = buildObject()..parent = parent;
+  void _fillTreeNodeList(List<TreeNode> list, TreeNode buildObject(),

[ahe, 2017/07/06 13:12:22]

If it isn't just me that find this method confusing to begin with, I suggest
that you remove the parameter shouldWriteData and add this method instead:

void _skipNodeList(void buildObject()) {
  int length = readUInt();
  for (int i = 0; i < length; i++) {
    buildObject();
  }
}

[Siggi Cherem (dart-lang), 2017/07/06 19:05:28]

I like it. Done.

+      TreeNode parent, bool shouldWriteData) {
+    var length = readUInt();
+    if (shouldWriteData) list.length = length;
+    for (int i = 0; i < length; ++i) {
+      TreeNode object = buildObject();
+      if (shouldWriteData) {
+        list[i] = object..parent = parent;
+      }
     }
   }
 
-  void _fillNonTreeNodeList(List<Node> list, Node buildObject()) {
-    list.length = readUInt();
-    for (int i = 0; i < list.length; ++i) {
-      list[i] = buildObject();
+  void _fillNonTreeNodeList(
+      List<Node> list, Node buildObject(), bool shouldWriteData) {
+    var length = readUInt();
+    if (shouldWriteData) list.length = length;
+    for (int i = 0; i < length; ++i) {
+      Node object = buildObject();
+      if (shouldWriteData) {
+        list[i] = object;
+      }
     }
   }
 
   /// Reads a list of named nodes, reusing any existing objects already in the
   /// linking tree. The nodes are merged into [list], and if reading the library
   /// implementation, the order is corrected.
   ///
   /// [readObject] should read the object definition and its canonical name.
   /// If an existing object is bound to the canonical name, the existing object
   /// must be reused and returned.
   void _mergeNamedNodeList(
       List<NamedNode> list, NamedNode readObject(), TreeNode parent) {
     if (_isReadingLibraryImplementation) {
       // When reading the library implementation, overwrite the whole list
       // with the new one.
-      _fillTreeNodeList(list, readObject, parent);
+      _fillTreeNodeList(list, readObject, parent, true);
     } else {
       // When reading an external library, the results should either be:
       // - merged with the existing external library definition (if any)
       // - ignored if the library implementation is already in memory
       int numberOfNodes = readUInt();
       for (int i = 0; i < numberOfNodes; ++i) {
         var value = readObject();
         // We use the parent pointer of a node to determine if it already is in
         // the AST and hence should not be added again.
         if (value.parent == null) {
@@ skipping 151 matching lines @@
     String fileUri = readUriReference();
 
     if (shouldWriteData) {
       library.isExternal = isExternal;
       library.name = name;
       library.fileUri = fileUri;
     }
 
     debugPath.add(library.name ?? library.importUri?.toString() ?? 'library');
 
-    _fillTreeNodeList(library.annotations, readExpression, library);
+    _fillTreeNodeList(
+        library.annotations, readExpression, library, shouldWriteData);
     _readLibraryDependencies(library);
     _mergeNamedNodeList(library.typedefs, readTypedef, library);
     _mergeNamedNodeList(library.classes, readClass, library);
     _mergeNamedNodeList(library.fields, readField, library);
     _mergeNamedNodeList(library.procedures, readProcedure, library);
 
     debugPath.removeLast();
     _currentLibrary = null;
     return library;
   }
@@ skipping 68 matching lines @@
     if (level.index >= node.level.index) {
       node.level = level;
     }
     var name = readStringOrNullIfEmpty();
     var fileUri = readUriReference();
     var annotations = readAnnotationList(node);
     debugPath.add(node.name ?? 'normal-class');
     readAndPushTypeParameterList(node.typeParameters, node);
     var supertype = readSupertypeOption();
     var mixedInType = readSupertypeOption();
-    _fillNonTreeNodeList(node.implementedTypes, readSupertype);
+    _fillNonTreeNodeList(node.implementedTypes, readSupertype, shouldWriteData);
     _mergeNamedNodeList(node.fields, readField, node);
     _mergeNamedNodeList(node.constructors, readConstructor, node);
     _mergeNamedNodeList(node.procedures, readProcedure, node);
     typeParameterStack.length = 0;
     debugPath.removeLast();
     if (shouldWriteData) {
       node.name = name;
       node.fileUri = fileUri;
       node.annotations = annotations;
       node.supertype = supertype;
@@ skipping 63 matching lines @@
     var fileOffset = readOffset();
     var fileEndOffset = readOffset();
     var flags = readByte();
     readUInt(); // parent class binary offset.
     var name = readName();
     var annotations = readAnnotationList(node);
     debugPath.add(node.name?.name ?? 'constructor');
     var function = readFunctionNode();
     pushVariableDeclarations(function.positionalParameters);
     pushVariableDeclarations(function.namedParameters);
-    _fillTreeNodeList(node.initializers, readInitializer, node);
+    _fillTreeNodeList(
+        node.initializers, readInitializer, node, shouldWriteData);
     variableStack.length = 0;
     var transformerFlags = getAndResetTransformerFlags();
     debugPath.removeLast();
     if (shouldWriteData) {
       node.fileOffset = fileOffset;
       node.fileEndOffset = fileEndOffset;
       node.flags = flags;
       node.name = name;
       node.annotations = annotations;
       node.function = function..parent = node;
@@ skipping 658 matching lines @@
       ..fileOffset = offset
       ..fileEqualsOffset = fileEqualsOffset;
   }
 
   int readOffset() {
     // Offset is saved as unsigned,
     // but actually ranges from -1 and up (thus the -1)
     return readUInt() - 1;
   }
 }