VM: Make more globals constant where easily possible.

runtime/vm/flags.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/flags.h"
 
 #include "platform/assert.h"
 #include "vm/json_stream.h"
 #include "vm/os.h"
 
@@ skipping 270 matching lines @@
   while ((*equals != '\0') && (*equals != '=')) {
     equals++;
   }
 
   const char* argument = NULL;
 
   // Determine if this is an option argument.
   if (*equals != '=') {
     // No explicit option argument. Determine if there is a "no_" prefix
     // preceding the name.
-    const char* kNo1Prefix = "no_";
-    const char* kNo2Prefix = "no-";
+    const char* const kNo1Prefix = "no_";
+    const char* const kNo2Prefix = "no-";
     const intptr_t kNo1PrefixLen = strlen(kNo1Prefix);
     const intptr_t kNo2PrefixLen = strlen(kNo2Prefix);
     if (strncmp(option, kNo1Prefix, kNo1PrefixLen) == 0) {
       option += kNo1PrefixLen;  // Skip the "no_" when looking up the name.
       argument = "false";
     } else if (strncmp(option, kNo2Prefix, kNo2PrefixLen) == 0) {
       option += kNo2PrefixLen;  // Skip the "no-" when looking up the name.
       argument = "false";
     } else {
       argument = "true";
@@ skipping 49 matching lines @@
 
 
 bool Flags::ProcessCommandLineFlags(int number_of_vm_flags,
                                     const char** vm_flags) {
   if (initialized_) {
     return false;
   }
 
   qsort(flags_, num_flags_, sizeof flags_[0], CompareFlagNames);
 
-  const char* kPrefix = "--";
+  const char* const kPrefix = "--";
   const intptr_t kPrefixLen = strlen(kPrefix);
 
   int i = 0;
   while ((i < number_of_vm_flags) &&
          IsValidFlag(vm_flags[i], kPrefix, kPrefixLen)) {
     const char* option = vm_flags[i] + kPrefixLen;
     Parse(option);
     i++;
   }
 
@@ skipping 91 matching lines @@
 void Flags::PrintJSON(JSONStream* js) {
   JSONObject jsobj(js);
   jsobj.AddProperty("type", "FlagList");
   JSONArray jsarr(&jsobj, "flags");
   for (intptr_t i = 0; i < num_flags_; ++i) {
     PrintFlagToJSONArray(&jsarr, flags_[i]);
   }
 }
 
 }  // namespace dart