Print messages when aborting background compilation (--trace-compiler); turn on background compilat…

runtime/vm/compiler.h

 // 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.
 
 #ifndef VM_COMPILER_H_
 #define VM_COMPILER_H_
 
 #include "vm/allocation.h"
 #include "vm/growable_array.h"
 #include "vm/runtime_entry.h"
@@ skipping 128 matching lines @@
 
   // Eagerly compiles all functions in a class.
   //
   // Returns Error::null() if there is no compilation error.
   static RawError* CompileAllFunctions(const Class& cls);
 
   // Notify the compiler that background (optimized) compilation has failed
   // because the mutator thread changed the state (e.g., deoptimization,
   // deferred loading). The background compilation may retry to compile
   // the same function later.
-  static void AbortBackgroundCompilation(intptr_t deopt_id);
+  static void AbortBackgroundCompilation(intptr_t deopt_id,
+                                         const char* msg = "");
 };
 
 
 // Class to run optimizing compilation in a background thread.
 // Current implementation: one task per isolate, it dies with the owning
 // isolate.
 // No OSR compilation in the background compiler.
 class BackgroundCompiler : public ThreadPool::Task {
  public:
   virtual ~BackgroundCompiler();
@@ skipping 23 matching lines @@
   Monitor* done_monitor_;   // Notify/wait that the thread is done.
 
   BackgroundCompilationQueue* function_queue_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(BackgroundCompiler);
 };
 
 }  // namespace dart
 
 #endif  // VM_COMPILER_H_