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&gt; > --- > 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