AbortOptimization, RetryOptimization preserve first bailout reason

src/compiler.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_H_
 #define V8_COMPILER_H_
 
 #include "src/allocation.h"
 #include "src/ast.h"
 #include "src/bailout-reason.h"
@@ skipping 312 matching lines @@
 
   void SaveHandles() {
     SaveHandle(&closure_);
     SaveHandle(&shared_info_);
     SaveHandle(&context_);
     SaveHandle(&script_);
     SaveHandle(&unoptimized_code_);
   }
 
   void AbortOptimization(BailoutReason reason) {
-    if (bailout_reason_ != kNoReason) bailout_reason_ = reason;

[wingo, 2015/01/12 18:06:50]

Because bailout_reason_ is initialized to kUnknown and not kNoReason, and
nothing sets bailout_reason_ to kNoReason, that I can see, this condition will
always be true.

+    DCHECK(reason != kNoReason);
+    if (bailout_reason_ == kNoReason) bailout_reason_ = reason;
     SetFlag(kDisableFutureOptimization);
   }
 
   void RetryOptimization(BailoutReason reason) {
-    if (bailout_reason_ != kNoReason) bailout_reason_ = reason;
+    DCHECK(reason != kNoReason);
+    if (GetFlag(kDisableFutureOptimization)) return;
+    bailout_reason_ = reason;
   }
 
   BailoutReason bailout_reason() const { return bailout_reason_; }
 
   int prologue_offset() const {
     DCHECK_NE(Code::kPrologueOffsetNotSet, prologue_offset_);
     return prologue_offset_;
   }
 
   void set_prologue_offset(int prologue_offset) {
@@ skipping 402 matching lines @@
   Zone zone_;
   unsigned info_zone_start_allocation_size_;
   base::ElapsedTimer timer_;
 
   DISALLOW_COPY_AND_ASSIGN(CompilationPhase);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_COMPILER_H_