xl: disk parsing preparation for empty cdrom devices

Prepare the ground for parsing the xend empty cdrom syntax, by
separating out some non-functional changes as this pre-patch:

* Clarify the disk syntax documentation wording to refer to deprecated
  syntaxes too.

* Make DPC in libxlu_disk_l.l useable in the helper functions as well
  as in lexer rules, by providing two definitions, each in force in
  the appropriate parts of the file.

* Break the <vdev>[:<devtype>] parsing out into a helper function,
  `vdev_and_devtype'.

No functional change.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>

1 files changed, 6 insertions, 5 deletions

diff --git a/docs/misc/xl-disk-configuration.txt b/docs/misc/xl-disk-configuration.txt
index 3bf20bf968..740b8f6429 100644
--- a/docs/misc/xl-disk-configuration.txt
+++ b/docs/misc/xl-disk-configuration.txt
@@ -164,16 +164,17 @@ information to be interpreted by /etc/xen/scripts/block-<script>.
 
 
 
-==================================
-DEPRECATED PARAMETERS AND PREFIXES
-==================================
+============================================
+DEPRECATED PARAMETERS, PREFIXES AND SYNTAXES
+============================================
 
-Deprecated values are acceptable and are intended work compatibly with
+Deprecated forms are acceptable and are intended work compatibly with
 xend and xl from xen 4.1.  In future they may print a warning.
 Support for deprecated parameters and syntaxes are likely to be
 dropped in future versions of xl.
 
-There is also support for a deprecated old syntax for <diskspec>:
+
+There is support for a deprecated old syntax for <diskspec>:
 
   [<format>:][<target>],<vdev>[:<devtype>],<access>   (deprecated)