Re: [libvirt] [PATCH 5/5] query-command-line-options: return help message for legacy options
On 01/27/2014 08:53 PM, Amos Kong wrote:
Some legacy options that have arguments weren't added to
vm_config_groups[], so query-command-line-options returns a
NULL parameters infolist. This patch try to return help message
for this kind of legacy options.
Example:
{
"helpmsg": "\"-vnc display start a VNC server on
display\\n\"",
"parameters": [
],
"option": "vnc"
},
Signed-off-by: Amos Kong <akong(a)redhat.com>
---
qapi-schema.json | 5 ++++-
util/qemu-config.c | 3 +++
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/qapi-schema.json b/qapi-schema.json
index 05ced9d..b3e6f46 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -3943,13 +3943,16 @@
# Details about a command line option, including its list of parameter details
#
# @option: option name
+# @helpmsg: help message for legacy options
Missing "#optional" and "(since 2.0)" designations
#
# @parameters: an array of @CommandLineParameterInfo
Might be worth documenting "#optional since 2.0" (we don't yet have good
precedent for documenting when a formerly mandatory field became optional).
Groan. This is an output struct. On input structs, changing a
mandatory field to optional is safe - old callers will always supply the
field. But on output structs, changing a mandatory field to optional is
backwards-incompatible. Old callers may be blindly expecting the field,
and crash when it is not present.
Your approach needs to be modified.
#
# Since 1.5
##
{ 'type': 'CommandLineOptionInfo',
- 'data': { 'option': 'str', 'parameters':
['CommandLineParameterInfo'] } }
+ 'data': { 'option': 'str',
+ '*parameters': ['CommandLineParameterInfo'],
+ '*helpmsg': 'str' } }
I suggest:
# @parameters: array of @CommandLineParameterInfo, possibly empty
# @argument: @optional present if the @parameters array is empty. If
# true, then the option takes unspecified arguments, if
# false, then the option is merely a boolean flag (since 2.0)
{ 'type': 'CommandLineOptionInfo',
'data': { 'option': 'str', 'parameters':
['CommandLineParameterInfo'],
'*argument': 'bool' } }
used as:
[
{ "option":"enable-fips", "parameters":[],
"argument":false },
{ "option":"smbios", "parameters":[],
"argument":true },
{ "option":"iscsi", "paramters":[ ... ] },
...
]
which adequately differentiates between -iscsi taking arguments (but
where we haven't yet hooked it in to introspect those arguments) vs.
-enable-fips being boolean.
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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