On Wed, Feb 12, 2014 at 02:00:51PM -0700, Eric Blake wrote:
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@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":[ ... ] }, ... ]
It's ok to use a split "argument" to indicate if option has parameters. and the parameters will not be optional, it will be NULL list in the case of no parameters. Thanks.
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
-- Amos.