Support local variables in dart2dart.

sdk/lib/_internal/compiler/implementation/ir/ir_unpickler.dart

 // Copyright (c) 2013, 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.
 
 part of dart2js.ir_pickler;
 
 class Unpickler {
   final Compiler compiler;
 
   final IrConstantPool constantPool;
@@ skipping 103 matching lines @@
       root = current = expr;
     } else {
       current = current.plug(expr);
     }
   }
 
   // Read a single expression and plug it into the outer context.
   ir.Expression readExpressionNode() {
     int tag = readByte();
     switch (tag) {
+      // Nontail-position expressions.
       case Pickles.NODE_CONSTANT:
         ir.Definition constant = readConstant();
         unpickled[index++] = constant;
         addExpression(new ir.LetPrim(constant));
         break;
       case Pickles.NODE_LET_CONT:
         int parameterCount = readInt();
         List<ir.Parameter> parameters = new List<ir.Parameter>.generate(
             parameterCount, (i) => new ir.Parameter(null));
         ir.Continuation continuation = new ir.Continuation(parameters);
         unpickled[index++] = continuation;
         ir.Expression body = readDelimitedExpressionNode();
         parameters.forEach((p) => unpickled[index++] = p);
         addExpression(new ir.LetCont(continuation, body));
         break;
+
+      // Tail-position expressions.
       case Pickles.NODE_INVOKE_STATIC:
         addExpression(readInvokeStatic());
         current = null;
         break;
       case Pickles.NODE_INVOKE_CONTINUATION:
         addExpression(readInvokeContinuation());
         current = null;
         break;
+      case Pickles.NODE_BRANCH:
+        addExpression(readBranch());
+        current = null;
+        break;
+
       default:
         compiler.internalError(NO_LOCATION_SPANNABLE,
                                "Unexpected expression entry tag: $tag");
         break;
     }
   }
 
   // Iteratively read expressions until an expression in a tail position
   // (e.g., an invocation) is found.  Do not change the outer context.
   ir.Expression readDelimitedExpressionNode() {
@@ skipping 52 matching lines @@
     FunctionElement functionElement = readElement();
     Selector selector = readSelector();
     ir.Continuation continuation = readBackReference();
     List<ir.Definition> arguments = readBackReferenceList();
     return new ir.InvokeStatic(functionElement, selector, continuation,
                                arguments);
   }
 
   ir.InvokeContinuation readInvokeContinuation() {
     ir.Continuation continuation = readBackReference();
-    ir.Definition argument = readBackReference();
-    return new ir.InvokeContinuation(continuation, argument);
+    List<ir.Definition> arguments = readBackReferenceList();
+    return new ir.InvokeContinuation(continuation, arguments);
+  }
+
+  ir.Branch readBranch() {
+    ir.Condition condition = readCondition();
+    ir.Continuation trueContinuation = readBackReference();
+    ir.Continuation falseContinuation = readBackReference();
+    return new ir.Branch(condition, trueContinuation, falseContinuation);
+  }
+
+  ir.Condition readCondition() {
+    int tag = readByte();
+    assert(tag == Pickles.NODE_IS_TRUE);
+    return readIsTrue();
+  }
+
+  ir.IsTrue readIsTrue() {
+    ir.Definition value = readBackReference();
+    return new ir.IsTrue(value);
   }
 
   Constant readConstantValue() {
     int tag = readByte();
     switch(tag) {
       case Pickles.CONST_BOOL:
         return constantSystem.createBool(readByte() == 1);
       case Pickles.CONST_INT:
         return constantSystem.createInt(readInt());
       case Pickles.CONST_DOUBLE:
@@ skipping 27 matching lines @@
       case Pickles.CONST_STRING_CONS:
         return new ast.ConsDartString(
             readDartString(readByte()), readDartString(readByte()));
       default:
         compiler.internalError(NO_LOCATION_SPANNABLE,
                                "Unexpected dart string tag: $tag");
         return null;
     }
   }
 }