Re: [Qemu-devel] [PATCH] RFC: options parse in vl.c should be moduled

[Anthony Liguori <anthony@codemonkey.ws>]

On 03/30/2012 10:59 AM, Lluís Vilanova wrote:
> Wanpeng Li writes:
>
>> Consider of the options parse process in main function of vl.c is too
>> long.It should be module into single function to clear ideas, strengthen
>> the source code management, and increase code readability.So I module the
>> process of options parse as function options_parse, and expose some variables
>> in order to not influence command-line invocations.
>
> Another approach would be to use something similar to QOM type registration.
>
> In order to keep code to a minimum, you can define an array of pointers to
> QParameter structures, instead of an array of function pointers (what
> __attribute__((constructors)) does).
>
> So, for example:
>
>      static void opt_icount_handler(const char *args)
>      {
>          if (kvm_enabled() || xen_enabled()) {
>              fprintf(stderr, "-icount is not allowed with kvm or xen\n");
>              exit(1);
>          }
>          /* ... contents of configure_icount ... */
>      }
>
>      static QEMUOption opt_icount = {
>         .name = "icount",
>         .signature = "[N|auto]",
>         .help = "enable virtual instruction counter with 2^N clock ticks per instruction",
>         .mode = QEMU_MODE_SYSTEM,
>         .priority = QEMU_OPT_PRIO_BEFORE_DEVICES,
>         .section = QEMU_OPT_SECTION_DEBUG,
>         .handler = opt_icount_handler
>      };
>
>      param_register(opt_icount);
>
>
> Here, param_register would define an array of pointers to QEMUOption structures,
> although I'm not sure how this can be handled on formats other than ELF.

My plan is to have a -query-capabilities so we can change the help text, then 
use GOptionContext.

It would take a small function that goes through and promotes any option in the 
format '-foo' to '--foo'.  But that's not too hard.

Then we can completely rip out the option parsing, qemu-options.hx, and all of 
that other junk.

Regards,

Anthony Liguori