Change --code-comments default to true. Code comments activated only if disassembly is activated.

runtime/vm/assembler.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/assembler.h"
 
 #include "platform/utils.h"
 #include "vm/cpu.h"
 #include "vm/heap.h"
 #include "vm/memory_region.h"
 #include "vm/os.h"
 #include "vm/zone.h"
 
 namespace dart {
 
-DEFINE_FLAG(bool, code_comments, false,
+DEFINE_FLAG(bool, code_comments, true,
             "Include comments into code and disassembly");
 #if defined(TARGET_ARCH_ARM) || defined(TARGET_ARCH_MIPS)
 DEFINE_FLAG(bool, use_far_branches, false,
             "Enable far branches for ARM and MIPS");
 #endif
 
+DECLARE_FLAG(bool, disassemble);
+DECLARE_FLAG(bool, disassemble_optimized);
+
 static uword NewContents(intptr_t capacity) {
   Zone* zone = Isolate::Current()->current_zone();
   uword result = zone->AllocUnsafe(capacity);
 #if defined(DEBUG)
   // Initialize the buffer with kBreakPointInstruction to force a break
   // point if we ever execute an uninitialized part of the code buffer.
   Assembler::InitializeMemoryWithBreakpoints(result, capacity);
 #endif
   return result;
 }
@@ skipping 167 matching lines @@
 void Assembler::Unreachable(const char* message) {
   const char* format = "Unreachable: %s";
   const intptr_t len = OS::SNPrint(NULL, 0, format, message);
   char* buffer = reinterpret_cast<char*>(malloc(len + 1));
   OS::SNPrint(buffer, len + 1, format, message);
   Stop(buffer);
 }
 
 
 void Assembler::Comment(const char* format, ...) {
-  if (FLAG_code_comments) {
+  if (FLAG_code_comments && (FLAG_disassemble || FLAG_disassemble_optimized)) {
     char buffer[1024];
 
     va_list args;
     va_start(args, format);
     OS::VSNPrint(buffer, sizeof(buffer), format, args);
     va_end(args);
 
     comments_.Add(new CodeComment(buffer_.GetPosition(),
                                   String::Handle(String::New(buffer))));
   }
 }
 
 
 const Code::Comments& Assembler::GetCodeComments() const {
   Code::Comments& comments = Code::Comments::New(comments_.length());
 
   for (intptr_t i = 0; i < comments_.length(); i++) {
     comments.SetPCOffsetAt(i, comments_[i]->pc_offset());
     comments.SetCommentAt(i, comments_[i]->comment());
   }
 
   return comments;
 }
 
 }  // namespace dart