dart2js-kernel: implement rethrow

pkg/compiler/lib/src/ssa/builder_kernel.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.
 
 import 'package:kernel/ast.dart' as ir;
 
 import '../closure.dart';
 import '../common.dart';
 import '../common/codegen.dart' show CodegenRegistry, CodegenWorkItem;
 import '../common/names.dart';
 import '../common/tasks.dart' show CompilerTask;
 import '../compiler.dart';
 import '../constants/values.dart'
     show
         ConstantValue,
         InterceptorConstantValue,
         StringConstantValue,
+        SyntheticConstantValue,
+  //SyntheticConstantKind,

[sra1, 2017/01/09 19:20:17]

I'm fixing this now and reformatting

         TypeConstantValue;
 import '../elements/resolution_types.dart';
 import '../elements/elements.dart';
 import '../io/source_information.dart';
 import '../js/js.dart' as js;
-import '../js_backend/backend.dart' show JavaScriptBackend;
+import '../js_backend/backend.dart' show JavaScriptBackend, SyntheticConstantKind;
 import '../kernel/kernel.dart';
 import '../native/native.dart' as native;
 import '../resolution/tree_elements.dart';
 import '../tree/dartstring.dart';
 import '../tree/nodes.dart' show Node, BreakStatement;
 import '../types/masks.dart';
 import '../universe/call_structure.dart' show CallStructure;
 import '../universe/selector.dart';
 import '../universe/side_effects.dart' show SideEffects;
 import '../universe/use.dart' show StaticUse;
@@ skipping 2173 matching lines @@
     bool old = _inExpressionOfThrow;
     try {
       _inExpressionOfThrow = true;
       expression.accept(this);
     } finally {
       _inExpressionOfThrow = old;
     }
   }
 
   @override
+  void visitRethrow(ir.Rethrow rethrowNode) {
+    HInstruction exception = rethrowableException;
+    if (exception == null) {
+      exception = graph.addConstantNull(closedWorld);
+      reporter.internalError(node, 'rethrowableException should not be null.');
+    }
+    Sourceinformation sourceInformation = null;
+    closeAndGotoExit(new HThrow(exception, sourceInformation, isRethrow: true));
+    // ir.Rethrow is an expression so we need to push a value - a constant with
+    // no type.
+    stack.add(graph.addConstantUnreachable(closedWorld));
+  }
+
+  @override
   void visitThisExpression(ir.ThisExpression thisExpression) {
     stack.add(localsHandler.readThis());
   }
 
   @override
   void visitNot(ir.Not not) {
     not.operand.accept(this);
     push(new HNot(popBoolified(), commonMasks.boolType));
   }
 
@@ skipping 259 matching lines @@
     kernelBuilder.open(exitBlock);
     enterBlock.setBlockFlow(
         new HTryBlockInformation(
             kernelBuilder.wrapStatementGraph(bodyGraph),
             exception,
             kernelBuilder.wrapStatementGraph(catchGraph),
             kernelBuilder.wrapStatementGraph(finallyGraph)),
         exitBlock);
   }
 }