Convert closures in all initializers, and share the context between them.

pkg/kernel/lib/transformations/argument_extraction.dart

+// Copyright (c) 2017, 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.argument_extraction;
+
+import '../ast.dart'
+    show
+        Constructor,
+        FieldInitializer,
+        Initializer,
+        Library,
+        LocalInitializer,
+        Program,
+        VariableDeclaration,
+        VariableGet;
+import '../core_types.dart' show CoreTypes;
+import '../visitor.dart' show Transformer;
+
+Program transformProgram(CoreTypes coreTypes, Program program) {
+  new ArgumentExtractionForTesting().visitProgram(program);
+  return program;
+}
+
+void transformLibraries(CoreTypes coreTypes, List<Library> libraries) {
+  var transformer = new ArgumentExtractionForTesting();
+  for (var library in libraries) {
+    transformer.visitLibrary(library);
+  }
+}
+
+class ArgumentExtractionForTesting extends Transformer {
+  visitConstructor(Constructor node) {
+    var newInits = <Initializer>[];
+
+    int nameCounter = 0;
+    for (var fieldInit in node.initializers) {
+      if (fieldInit is FieldInitializer &&
+          !fieldInit.field.name.name.endsWith("_li")) {
+        // Move the body of the initializer to a new local initializer, and
+        // eta-expand the reference to the local initializer in the body of the
+        // field initializer.
+        var value = fieldInit.value;
+
+        var decl = new VariableDeclaration('#li_$nameCounter');
+        decl.initializer = value;
+        var localInit = new LocalInitializer(decl);
+        localInit.parent = node;
+        newInits.add(localInit);
+
+        fieldInit.value = new VariableGet(decl);
+        fieldInit.value.parent = fieldInit;
+
+        ++nameCounter;
+        newInits.add(fieldInit);
+      } else {
+        newInits.add(fieldInit);
+      }
+    }
+
+    node.initializers = newInits;
+    return super.visitConstructor(node);
+  }
+}