- Support "no_" as well as "no-" prefix on boolean flags.

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/os.h"
 
 namespace dart {
@@ skipping 154 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* kNoPrefix = "no_";
-    const intptr_t kNoPrefixLen = strlen(kNoPrefix);
-    if (strncmp(option, kNoPrefix, kNoPrefixLen) == 0) {
-      option += kNoPrefixLen;  // Skip the "no_" when looking up the name.
+    const char* kNo1Prefix = "no_";
+    const char* 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";
     }
   } else {
     // The argument for the option starts right after the equals sign.
     argument = equals + 1;
   }
 
   // Initialize the flag name.
   intptr_t name_len = equals - option;
   char* name = new char[name_len + 1];
   strncpy(name, option, name_len);
   name[name_len] = '\0';
   Normalize(name);

[siva, 2012/03/10 00:19:49]

Would it not work if this normalization block is moved above and a if
(strncmp(name, kNoPrefix....) is done?

[Ivan Posva, 2012/03/10 00:31:30]

That would work too, but then you have to ensure to not normalize the parameters
to string flags.

 
   Flag* flag = Flags::Lookup(name);
   if (flag == NULL) {
     // Collect unrecognized flags.
     char* new_flag = new char[name_len + 1];
     strncpy(new_flag, name, name_len);
     new_flag[name_len] = '\0';
     Flags::Register_bool(NULL, new_flag, true, NULL);
   } else {
     // Only set values for recognized flags, skip collected
@@ skipping 97 matching lines @@
     while (flag != NULL) {
       flag->Print();
       flag = flag->next_;
     }
   }
 
   return true;
 }
 
 }  // namespace dart