Reapply "Allow LetCont to bind multiple continuations."

pkg/compiler/lib/src/cps_ir/cps_ir_nodes_sexpr.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.ir_nodes_sexpr;
 
 import '../constants/values.dart';
 import '../util/util.dart';
 import 'cps_ir_nodes.dart';
 
@@ skipping 58 matching lines @@
   }
 
   String visitLetPrim(LetPrim node) {
     String name = newValueName(node.primitive);
     String value = visit(node.primitive);
     String body = indentBlock(() => visit(node.body));
     return '$indentation(LetPrim ($name $value)\n$body)';
   }
 
   String visitLetCont(LetCont node) {
-    String cont = newContinuationName(node.continuation);
-    // TODO(karlklose): this should be changed to `.map(visit).join(' ')`  and
-    // should recurse to [visit].  Currently we can't do that, because the
-    // unstringifier_test produces [LetConts] with dummy arguments on them.
-    String parameters = node.continuation.parameters
-        .map((p) => '${decorator(p, newValueName(p))}')
-        .join(' ');
-    String contBody =
-        indentBlock(() => indentBlock(() => visit(node.continuation.body)));
+    String conts;
+    bool first = true;
+    for (Continuation continuation in node.continuations) {
+      String name = newContinuationName(continuation);
+      if (continuation.isRecursive) name = 'rec $name';
+      // TODO(karlklose): this should be changed to `.map(visit).join(' ')`  and
+      // should recurse to [visit].  Currently we can't do that, because the
+      // unstringifier_test produces [LetConts] with dummy arguments on them.
+      String parameters = continuation.parameters
+          .map((p) => '${decorator(p, newValueName(p))}')
+          .join(' ');
+      String body =
+          indentBlock(() => indentBlock(() => visit(continuation.body)));
+      if (first) {
+        first = false;
+        conts = '($name ($parameters)\n$body)';
+      } else {
+        // Each subsequent line is indented additional spaces to align it
+        // with the previous continuation.
+        String indent = '$indentation${' ' * '(LetCont ('.length}';
+        conts = '$conts\n$indent($name ($parameters)\n$body)';
+      }
+    }
     String body = indentBlock(() => visit(node.body));
-    String op = node.continuation.isRecursive ? 'LetCont*' : 'LetCont';
-    return '$indentation($op ($cont ($parameters)\n'
-           '$contBody)\n'
-           '$body)';
+    return '$indentation($LetCont ($conts)\n$body)';
   }
 
   String formatArguments(Invoke node) {
     int positionalArgumentCount = node.selector.positionalArgumentCount;
     List<String> args = new List<String>();
     args.addAll(
         node.arguments.getRange(0, positionalArgumentCount).map(access));
     for (int i = 0; i < node.selector.namedArgumentCount; ++i) {
       String name = node.selector.namedArguments[i];
-      Definition arg = node.arguments[positionalArgumentCount + i].definition;
+      String arg = access(node.arguments[positionalArgumentCount + i]);
       args.add("($name: $arg)");
     }
     return '(${args.join(' ')})';
   }
 
   String visitInvokeStatic(InvokeStatic node) {
     String name = node.target.name;
     String cont = access(node.continuation);
     String args = formatArguments(node);
     return '$indentation(InvokeStatic $name $args $cont)';
@@ skipping 242 matching lines @@
   void setReturnContinuation(Continuation node) {
     assert(!_names.containsKey(node) || _names[node] == 'return');
     _names[node] = 'return';
   }
 
   String getName(Node node) {
     assert(_names.containsKey(node));
     return _names[node];
   }
 }