cpsir: fix co19 test - use process* instead of visit* (we unadvertly removed code that recursed int…

pkg/compiler/lib/src/cps_ir/insert_refinements.dart

 // Copyright (c) 2015, 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 cps_ir.optimization.insert_refinements;
 
 import 'dart:math' show min;
 import 'optimizers.dart' show Pass;
 import 'cps_ir_nodes.dart';
 import '../elements/elements.dart';
@@ skipping 109 matching lines @@
       TypeMask argSuccessType = argumentSuccessTypes[i];
 
       // Skip arguments that provide no refinement.
       if (argSuccessType == types.dynamicType) continue;
 
       applyRefinement(node.parent,
           new Refinement(node.dartArgument(i), argSuccessType));
     }
   }
 
-  void visitInvokeStatic(InvokeStatic node) {
+  void processInvokeStatic(InvokeStatic node) {

[asgerf, 2016/01/11 21:35:06]

Please do like in visitInvokeMethod and visitTypeTest, call the processReference
method explicitly.

processInvokeStatic is called before its operands are processed, which is the
wrong order for this pass.

Now we will be updating the refinement environment before visiting the
references so the invoke will end up seeing its own refined values. That is, we
will get code like:

x' = refine(x, int)
InvokeStatic checkInt (x')

Instead of:

InvokeStatic checkInt (x)
x' = refine(x, int)


It seems strange that this would make the test pass. Maybe it passed for the
wrong reason in the first place?

[Siggi Cherem (dart-lang), 2016/01/11 21:51:09]

good catch! Done.

Before I sent this I haven't yet run all the other test, just the co19 test that
failed on the bots. Turns out that the unittest for static methods did caught
this and shows exactly the issue you mention.

The co19 test was failing only because I was overriding visitInvokeStatic
without visiting the arguments entirely.

     _refineArguments(node,
         _getSuccessTypesForStaticMethod(types, node.target));
   }
 
   void visitInvokeMethod(InvokeMethod node) {
     // Update references to their current refined values.
     processReference(node.receiver);
     node.arguments.forEach(processReference);
 
     // If the call is intercepted, we want to refine the actual receiver,
@@ skipping 284 matching lines @@
       case 'exp':
       case 'log':
         return [types.numType];
       case 'pow':
         return [types.numType, types.numType];
     }
   }
 
   return null;
 }