First pass at adding ability for Memcheck to print all output in XML
form.  The relevant flag is --xml=yes.  Currently this only works with
Memcheck.

Specifying this flag fixes various other options relating to verbosity
and behaviour of the leak checker, so that the resulting output is in
a relatively fixed form suitable for parsing by GUIs.

Still to do:

* Add mechanism to show error counts
* Add regression test
* Document the resulting format



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@3773 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/include/pub_tool_options.h b/include/pub_tool_options.h
index e321635..e27e158 100644
--- a/include/pub_tool_options.h
+++ b/include/pub_tool_options.h
@@ -61,10 +61,15 @@
    }
 
 /* Verbosity level: 0 = silent, 1 (default), > 1 = more verbose. */
-extern Int   VG_(clo_verbosity);
+extern Int  VG_(clo_verbosity);
 
-/* Profile? */
-extern Bool  VG_(clo_profile);
+/* Profile?  default: NO */
+extern Bool VG_(clo_profile);
+
+/* Emit all messages as XML? default: NO */
+/* If clo_xml is set, various other options are set in a non-default
+   way.  See vg_main.c and mc_main.c. */
+extern Bool VG_(clo_xml);
 
 /* Call this if a recognised option was bad for some reason.
    Note: don't use it just because an option was unrecognised -- return 'False'