commit 61f157c8528c2b46f3234b4eea5a44df531d857d
author Ben Murdoch <benm@google.com> Fri Sep 16 13:49:30 2016 +0100
committer Dirk Vogt <dirk@fairphone.com> Fri Mar 17 16:06:52 2017 +0100
tree 3fa142ce2609b1fdf9d001275350184f71860fa3
parent c5610438f36f65235862a5f5020a739d29a5c32e

Merge V8 5.3.332.45.  DO NOT MERGE

Test: Manual

FPIIM-449

Change-Id: Id3254828b068abdea3cb10442e0172a8c9a98e03
(cherry picked from commit 13e2dadd00298019ed862f2b2fc5068bba730bcf)

src/flags.cc

diff --git a/src/flags.cc b/src/flags.cc
index f67defd..f7ae004 100644
--- a/src/flags.cc
+++ b/src/flags.cc
@@ -429,6 +429,10 @@
         PrintF(stderr, "Error: illegal value for flag %s of type %s\n"
                "Try --help for options\n",
                arg, Type2String(flag->type()));
+        if (is_bool_type) {
+          PrintF(stderr,
+                 "To set or unset a boolean flag, use --flag or --no-flag.\n");
+        }
         return_code = j;
         break;
       }