dart2js cps: Ensure definitions are specialized before their uses.

pkg/compiler/lib/src/cps_ir/cps_ir_builder.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.
 
 library dart2js.ir_builder;
 
 import '../compile_time_constants.dart' show BackendConstantEnvironment;
 import '../constants/constant_system.dart';
 import '../constants/values.dart' show ConstantValue, PrimitiveConstantValue;
 import '../dart_types.dart';
@@ skipping 173 matching lines @@
 
   void _buildTryExit(IrBuilder builder) {
     for (Iterable<LocalVariableElement> boxedOnEntry in _boxedTryVariables) {
       for (LocalVariableElement variable in boxedOnEntry) {
         assert(builder.isInMutableVariable(variable));
         ir.Primitive value = builder.buildLocalVariableGet(variable);
         builder.environment.update(variable, value);
       }
     }
   }
+
+  /// True if a jump inserted now will escape from a try block.
+  /// 
+  /// Concretely, this is true when [enterTry] has been called without
+  /// its corresponding [leaveTry] call.
+  bool get isEscapingTry => _boxedTryVariables.isNotEmpty;
 }
 
 /// A class to collect 'forward' jumps.
 ///
 /// A forward jump to a continuation in the sense of the CPS translation is
 /// a jump where the jump is emitted before any code in the body of the
 /// continuation is translated.  They have the property that continuation
 /// parameters and the environment for the translation of the body can be
 /// determined based on the invocations, before translating the body.  A
 /// [ForwardJumpCollector] can encapsulate a continuation where all the
@@ skipping 30 matching lines @@
   }
 
   Environment get environment {
     if (_continuation == null) _setContinuation();
     return _continuationEnvironment;
   }
 
   void addJump(IrBuilder builder, [ir.Primitive value]) {
     assert(_continuation == null);
     _buildTryExit(builder);
-    ir.InvokeContinuation invoke = new ir.InvokeContinuation.uninitialized();
+    ir.InvokeContinuation invoke = new ir.InvokeContinuation.uninitialized(
+        isEscapingTry: isEscapingTry);
     builder.add(invoke);
     _invocations.add(invoke);
     // Truncate the environment at the invocation site so it only includes
     // values that will be continuation arguments.  If an extra value is passed
     // it will already be included in the continuation environment, but it is
     // not present in the invocation environment.
     int delta = builder.environment.length - _continuationEnvironment.length;
     if (value != null) ++delta;
     if (delta > 0) builder.environment.discard(delta);
     if (value != null) builder.environment.extend(null, value);
@@ skipping 98 matching lines @@
     // Truncate the environment at the invocation site so it only includes
     // values that will be continuation arguments.  If an extra value is passed
     // it will already be included in the continuation environment, but it is
     // not present in the invocation environment.
     int delta = builder.environment.length - _continuationEnvironment.length;
     if (value != null) ++delta;
     if (delta > 0) builder.environment.discard(delta);
     if (value != null) builder.environment.extend(null, value);
     builder.add(new ir.InvokeContinuation(_continuation,
         builder.environment.index2value,
-        isRecursive: true));
+        isRecursive: true,
+        isEscapingTry: isEscapingTry));
     builder._current = null;
   }
 }
 
 /// Function for building a node in the context of the current builder.
 typedef ir.Node BuildFunction(node);
 
 /// Function for building nodes in the context of the provided [builder].
 typedef ir.Node SubbuildFunction(IrBuilder builder);
 
@@ skipping 2316 matching lines @@
 }
 
 class SwitchCaseInfo {
   final List<ir.Primitive> constants = <ir.Primitive>[];
   final SubbuildFunction buildBody;
 
   SwitchCaseInfo(this.buildBody);
 
   void addConstant(ir.Primitive constant) => constants.add(constant);
 }