Simplify code disabling logic in WeakCodeReferences.

runtime/vm/object.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/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 2505 matching lines @@
       } else if (function.unoptimized_code() == code.raw()) {
         ReportSwitchingCode(code);
         // Remove the code object from the function. The next time the
         // function is invoked, it will be compiled again.
         function.ClearCode();
         // Invalidate the old code object so existing references to it
         // (from optimized code) will fail when invoked.
         if (!CodePatcher::IsEntryPatched(code)) {
           CodePatcher::PatchEntry(code);
         }
-      } else if (!function.HasCode() && (code.GetEntryPatchPc() != 0)) {
-        // The code has already been disconnected, make it invalid. Do not
-        // bother with OSR compiled code that has no valid entry-patch.
-        ReportSwitchingCode(code);
-        if (!CodePatcher::IsEntryPatched(code)) {
-          CodePatcher::PatchEntry(code);
+      } else {
+        // Make non-OSR code non-entrant.
+        if (code.GetEntryPatchPc() != 0) {
+          if (!CodePatcher::IsEntryPatched(code)) {
+            ReportSwitchingCode(code);
+            CodePatcher::PatchEntry(code);
+          }
         }
       }
     }
   }
 
  private:
   const Array& array_;
   DISALLOW_COPY_AND_ASSIGN(WeakCodeReferences);
 };
 
@@ skipping 7098 matching lines @@
   virtual void ReportDeoptimization(const Code& code) {
     // This gets called when the code object is on the stack
     // while nuking code that depends on a prefix. We don't expect
     // this to happen, so make sure we die loudly if we find
     // ourselves here.
     UNIMPLEMENTED();
   }
 
   virtual void ReportSwitchingCode(const Code& code) {
     if (FLAG_trace_deoptimization || FLAG_trace_deoptimization_verbose) {
-      OS::PrintErr("Prefix '%s': deleting %s code for %s function '%s'\n",
+      OS::PrintErr("Prefix '%s': disabling %s code for %s function '%s'\n",
         String::Handle(prefix_.name()).ToCString(),
         code.is_optimized() ? "optimized" : "unoptimized",
         CodePatcher::IsEntryPatched(code) ? "patched" : "unpatched",
         Function::Handle(code.function()).ToCString());
     }
   }
 
  private:
   const LibraryPrefix& prefix_;
   DISALLOW_COPY_AND_ASSIGN(PrefixDependentArray);
@@ skipping 9352 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart