Fix crash in VM when patching static calls. When the target code is optimized, it is possible that …

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 1419 matching lines @@
     UNREACHABLE();
   }
   ASSERT(frame->IsDartFrame());
   const Code& caller_code = Code::Handle(frame->LookupDartCode());
   ASSERT(caller_code.is_optimized());
   const Function& target_function = Function::Handle(
       caller_code.GetStaticCallTargetFunctionAt(frame->pc()));
   const Code& target_code = Code::Handle(
       caller_code.GetStaticCallTargetCodeAt(frame->pc()));
   ASSERT(!target_code.IsNull());
-  // Since there was a reference to the target_code in the caller_code, it is
-  // not possible for the target_function's code to be disconnected.
+  if (!target_function.HasCode()) {
+    // If target code was unoptimized than the code must have been kept
+    // connected to the function.
+    ASSERT(target_code.is_optimized());
+    const Error& error =
+        Error::Handle(Compiler::CompileFunction(target_function));
+    if (!error.IsNull()) {
+      Exceptions::PropagateError(error);
+    }
+  }
   ASSERT(target_function.HasCode());
   ASSERT(target_function.raw() == target_code.function());
 
   const Code& current_target_code = Code::Handle(target_function.CurrentCode());
   CodePatcher::PatchStaticCallAt(frame->pc(), caller_code,
                                  current_target_code.EntryPoint());
   caller_code.SetStaticCallTargetCodeAt(frame->pc(), current_target_code);
   if (FLAG_trace_patching) {
     OS::PrintErr("FixCallersTarget: patching from %#" Px " to '%s' %#" Px "\n",
         frame->pc(),
@@ skipping 227 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