Fixes a couple problems with GC of unoptimized code.

runtime/vm/code_generator.cc

 // 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.
 
 #include "vm/code_generator.h"
 
 #include "vm/assembler.h"
 #include "vm/ast.h"
 #include "vm/bigint_operations.h"
 #include "vm/code_patcher.h"
@@ skipping 1325 matching lines @@
   if (interrupt_bits & Isolate::kVmStatusInterrupt) {
     Dart_IsolateInterruptCallback callback = isolate->VmStatsCallback();
     if (callback) {
       (*callback)();
     }
   }
 
   if (FLAG_use_osr && (interrupt_bits == 0)) {
     DartFrameIterator iterator;
     StackFrame* frame = iterator.NextFrame();
-    const Function& function = Function::Handle(frame->LookupDartFunction());
+    const Code& code = Code::ZoneHandle(frame->LookupDartCode());
+    const Function& function = Function::Handle(code.function());
     ASSERT(!function.IsNull());
-    if (!CanOptimizeFunction(function, isolate)) return;
+    if (!function.HasCode()) {

[Ivan Posva, 2013/11/16 00:06:21]

Code should not be detachable as it is live on the stack.

[zra, 2013/11/18 18:54:33]

Changed to ASSERT.

+      function.ReattachCode(code);
+    }
+    if (!CanOptimizeFunction(function, isolate)) {
+      return;
+    }
     intptr_t osr_id =
         Code::Handle(function.unoptimized_code()).GetDeoptIdForOsr(frame->pc());
     if (FLAG_trace_osr) {
       OS::Print("Attempting OSR for %s at id=%" Pd ", count=%" Pd "\n",
                 function.ToFullyQualifiedCString(),
                 osr_id,
                 function.usage_counter());
     }
 
     const Code& original_code = Code::Handle(function.CurrentCode());
+    ASSERT(!original_code.IsNull());
     const Error& error =
         Error::Handle(Compiler::CompileOptimizedFunction(function, osr_id));
-    if (!error.IsNull()) Exceptions::PropagateError(error);
+    if (!error.IsNull()) {
+      Exceptions::PropagateError(error);
+    }
 
     const Code& optimized_code = Code::Handle(function.CurrentCode());
     // The current code will not be changed in the case that the compiler
     // bailed out during OSR compilation.
     if (optimized_code.raw() != original_code.raw()) {
       // The OSR code does not work for calling the function, so restore the
       // unoptimized code.  Patch the stack frame to return into the OSR
       // code.
       uword optimized_entry =
           Instructions::Handle(optimized_code.instructions()).EntryPoint();
@@ skipping 329 matching lines @@
 // of the given value.
 //   Arg0: Field object;
 //   Arg1: Value that is being stored.
 DEFINE_RUNTIME_ENTRY(UpdateFieldCid, 2) {
   const Field& field = Field::CheckedHandle(arguments.ArgAt(0));
   const Object& value = Object::Handle(arguments.ArgAt(1));
   field.UpdateGuardedCidAndLength(value);
 }
 
 }  // namespace dart