Handle top-level tear offs.

dart/pkg/dart2js_incremental/lib/library_updater.dart

 // Copyright (c) 2014, 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 dart2js_incremental.library_updater;
 
 import 'dart:async' show
     Future;
 
 import 'dart:convert' show
     UTF8;
 
 import 'package:compiler/compiler.dart' as api;
 
 import 'package:compiler/implementation/dart2jslib.dart' show
     Compiler,
     Script;
 
 import 'package:compiler/implementation/elements/elements.dart' show
     Element,
+    FunctionElement,
     LibraryElement;
 
 import 'package:compiler/implementation/scanner/scannerlib.dart' show
     EOF_TOKEN,
     PartialElement,
     PartialFunctionElement,
     Token;
 
 import 'package:compiler/implementation/source_file.dart' show
     StringSourceFile;
 
 import 'package:compiler/implementation/tree/tree.dart' show
     FunctionExpression;
 
 import 'package:compiler/implementation/js/js.dart' show
     js;
 
 import 'package:compiler/implementation/js/js.dart' as jsAst;
 
 import 'package:compiler/implementation/js_emitter/js_emitter.dart' show
-    ClassBuilder;
+    CodeEmitterTask,
+    MemberInfo;
 
 import 'package:compiler/js_lib/shared/embedded_names.dart' as embeddedNames;
 
+import 'package:compiler/implementation/js_backend/js_backend.dart' show
+    JavaScriptBackend,
+    Namer;
+
 import 'diff.dart' show
     Difference,
     computeDifference;
 
 typedef void Logger(message);
 
 // TODO(ahe): Generalize this class. For now only works for Compiler.mainApp,
 // and only if that library has exactly one compilation unit.
 class LibraryUpdater {
   final Compiler compiler;
@@ skipping 14 matching lines @@
 
   final List<Update> updates = <Update>[];
 
   LibraryUpdater(
       this.compiler,
       this.inputProvider,
       this.uri,
       this.logTime,
       this.logVerbose);
 
+  JavaScriptBackend get backend => compiler.backend;
+
+  Namer get namer => backend.namer;
+
+  CodeEmitterTask get emitter => backend.emitter;
+
   /// Used as tear-off passed to [LibraryLoaderTask.resetAsync].
   Future<bool> reuseLibrary(LibraryElement library) {
     assert(compiler != null);
     if (library.isPlatformLibrary || library.isPackageLibrary) {
       logTime('Reusing $library.');
       return new Future.value(true);
     } else if (library != compiler.mainApp) {
       return new Future.value(false);
     }
     return inputProvider(uri).then((bytes) {
@@ skipping 109 matching lines @@
 
     compiler.phase = Compiler.PHASE_DONE_RESOLVING;
 
     for (Element element in updatedElements) {
       compiler.enqueuer.codegen.addToWorkList(element);
     }
     compiler.processQueue(compiler.enqueuer.codegen, null);
 
     List<jsAst.Statement> updates = <jsAst.Statement>[];
     for (Element element in compiler.enqueuer.codegen.newlyEnqueuedElements) {
-      updates.add(computeMemberUpdateJs(element));
+      if (!element.isField) {
+        updates.add(computeMemberUpdateJs(element));
+      }
     }
 
     if (updates.length == 1) {
       return prettyPrintJs(updates.single);
     } else {
       return prettyPrintJs(js.statement('{#}', [updates]));
     }
   }
 
   jsAst.Node computeMemberUpdateJs(Element element) {
-    ClassBuilder builder = new ClassBuilder(element, compiler.backend.namer);
-
-    compiler.backend.emitter.oldEmitter.containerBuilder.addMember(
-        element, builder);
-    jsAst.Property property = builder.properties.single;
-    jsAst.Node name = property.name;
-    jsAst.Node function = property.value;
-    jsAst.Node elementAccess = compiler.backend.namer.elementAccess(element);
+    MemberInfo info = emitter.oldEmitter.containerBuilder
+        .analyzeMemberMethod(element);
+    if (info == null) {
+      compiler.internalError(element, '${element.runtimeType}');
+    }
+    String name = info.name;
+    jsAst.Node function = info.code;
+    jsAst.Node elementAccess = namer.elementAccess(element);
     jsAst.Expression globalFunctionsAccess =
-        compiler.backend.emitter.generateEmbeddedGlobalAccess(
-            embeddedNames.GLOBAL_FUNCTIONS);
+        emitter.generateEmbeddedGlobalAccess(embeddedNames.GLOBAL_FUNCTIONS);
     List<jsAst.Statement> statements = <jsAst.Statement>[];
     statements.add(
         js.statement(
             '#.# = # = f',
             [globalFunctionsAccess, name, elementAccess]));
+    if (info.canTearOff) {
+      String globalName = namer.globalObjectFor(element);
+      statements.add(
+          js.statement(
+              '#.#().# = f',
+              [globalName, info.tearOffName, callNameFor(element)]));
+    }
     // Create a scope by creating a new function. The updated function literal
     // is passed as an argument to this function which ensures that temporary
     // names in updateScope don't shadow global names.
     jsAst.Fun updateScope = js('function (f) { # }', [statements]);
     return js.statement('(#)(#)', [updateScope, function]);
   }
 
   String prettyPrintJs(jsAst.Node node) {
     jsAst.Printer printer = new jsAst.Printer(compiler, null);
     printer.blockOutWithoutBraces(node);
     return printer.outBuffer.getText();
   }
+
+  String callNameFor(FunctionElement element) {
+    // TODO(ahe): Call a method in the compiler to obtain this name.
+    String callPrefix = namer.callPrefix;
+    int parameterCount = element.functionSignature.parameterCount;
+    return '$callPrefix\$$parameterCount';
+  }
 }
 
 /// Represents an update (aka patch) of [before] to [after]. We use the word
 /// "update" to avoid confusion with the compiler feature of "patch" methods.
 abstract class Update {
   final Compiler compiler;
 
   PartialElement get before;
 
   PartialElement get after;
@@ skipping 26 matching lines @@
     before.getOrSet = after.getOrSet;
   }
 
   /// Reset various caches and remove this element from the compiler's internal
   /// state.
   void reuseElement() {
     compiler.forgetElement(before);
     before.reuseElement();
   }
 }