More general CHA-based inlining and devirtualization for precompiled code.

runtime/vm/cha.cc

 // Copyright (c) 2012, 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.
 
 #include "vm/cha.h"
 #include "vm/class_table.h"
 #include "vm/flags.h"
 #include "vm/freelist.h"
 #include "vm/object.h"
 #include "vm/raw_object.h"
@@ skipping 44 matching lines @@
   // read-only.
   // TODO(fschneider): Enable tracking of CHA dependent code for VM heap
   // classes.
   if (cls.InVMHeap()) return true;
 
   return cls.is_implemented();
 }
 
 
 bool CHA::HasOverride(const Class& cls, const String& function_name) {
-  const GrowableObjectArray& cls_direct_subclasses =
-      GrowableObjectArray::Handle(thread_->zone(), cls.direct_subclasses());
+  // Can't track dependencies for classes on the VM heap since those are
+  // read-only.
+  // TODO(fschneider): Enable tracking of CHA dependent code for VM heap
+  // classes.
+  if (cls.InVMHeap()) return true;
+
   // Subclasses of Object are not tracked by CHA. Safely assume that overrides
   // exist.
   if (cls.IsObjectClass()) {
     return true;
   }
 
+  const GrowableObjectArray& cls_direct_subclasses =
+      GrowableObjectArray::Handle(thread_->zone(), cls.direct_subclasses());
   if (cls_direct_subclasses.IsNull()) {
     return false;
   }
   Class& direct_subclass = Class::Handle(thread_->zone());
   for (intptr_t i = 0; i < cls_direct_subclasses.Length(); i++) {
     direct_subclass ^= cls_direct_subclasses.At(i);
     // Unfinalized classes are treated as non-existent for CHA purposes,
     // as that means that no instance of that class exists at runtime.
     if (direct_subclass.is_finalized() &&
         (direct_subclass.LookupDynamicFunction(function_name) !=
          Function::null())) {
       return true;
     }
     if (HasOverride(direct_subclass, function_name)) {
       return true;
     }
   }
   return false;
 }
 
 }  // namespace dart