Re: [Qemu-devel] [PATCH 2/2] Explicitly print out default vnc option in use

[Markus Armbruster]

Robert Hu <address@hidden> writes:

> On Mon, 2016-06-06 at 09:28 +0200, Markus Armbruster wrote:
>> Robert Hu <address@hidden> writes:
>> 
>> > On Tue, 2016-05-31 at 13:17 +0200, Markus Armbruster wrote:
>> >> Robert Hu <address@hidden> writes:
>> >> 
>> >> > On Tue, 2016-05-31 at 09:51 +0200, Markus Armbruster wrote:
> [trim...]
>> > I don't see a './configure' option related to this '-vnc to' param. Is
>> > there any?
>> > '--help', you mean 'qemu-system_x86-64 --help'? or './configure --help'?
> [seems repeated contents, trim...]
>> > I don't see a './configure' option related to this '-vnc to' param. Is
>> > there any?
>> > '--help', you mean 'qemu-system_x86-64 --help'? or './configure --help'?
>> 
>> The former.
>> 
>> The modern way to select a display is -display.  The older -nographic,
>> -curses, -sdl are retained for backward compatibility.
>> 
>> Relevant parts of -help:
>> 
>>     Display options:
>>     -display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]
>>                 [,window_close=on|off]|curses|none|
>>                 gtk[,grab_on_hover=on|off]|
>>                 vnc=<display>[,<optargs>]
>>                     select display type
>>     -nographic      disable graphical output and redirect serial I/Os to 
>> console
>>     -curses         use a curses/ncurses interface instead of SDL
>>     [...]
>>     -sdl            enable SDL
>>     [...]
>>     -vnc display    start a VNC server on display
>> 
>> Issues:
>> 
>> * Help for -display is broken: the mutually exclusive option arguments
>>   are concatenated.  -display curses and -display none are undocumented.
>>   It should look more like this:
>> 
>>     -display sdl[,frame=on|off][,alt_grab=on|off][,ctrl_grab=on|off]
>>                 [,window_close=on|off]|curses|none|
>>     -display gtk[,grab_on_hover=on|off]|
>>     -display vnc=<display>[,<optargs>]
>>     -display curses
>>     -display none
>>                     select display type
>> 
>> * -display sdl,gl=on|off and -display gtk,gl=on|off are undocumented
>>    (missed in commit 0b71a5d5c and 97edf3b).
>> 
>> * There is no help on the <display> in -display vnc=<display>.
>> 
>> * There is no help on the default.  main() picks the default depending
>>   on configure options:
>> 
>>     #if defined(CONFIG_GTK)
>>             display_type = DT_GTK;
>>     #elif defined(CONFIG_SDL)
>>             display_type = DT_SDL;
>>     #elif defined(CONFIG_COCOA)
>>             display_type = DT_COCOA;
>>     #elif defined(CONFIG_VNC)
>>             vnc_parse("localhost:0,to=99,id=default", &error_abort);
>>             show_vnc_port = 1;
>>     #else
>>             display_type = DT_NONE;
>>     #endif
>> 
>>   Help should show the default this binary will pick.  This is what I
>>   meant by "Ideally, --help output would show the defaults for this
>>   build's configuration."
>> 
>> * Help should explain syntacic sugar:
>>   -curses is sugar for -display curses
>>   -sdl is sugar for -display sdl
>>   -vnc display is sugar for -display vnc=display
>> 
>>   -nographic is also sugar, but too complicated to explain; I'd leave it
>>   as is.
>> 
>> Non-issue
>> 
>> * Help shows options even when they're not compiled in.  That's okay,
>>   because trying to use them fails with an "FOO support is disabled"
>>   error message.
>> 
>> >> If we decide users need more information than the current "VNC server
>> >> running on" line, perhaps it should be included right in that line.
>> 
>> This would complement, but not replace better -help ouput.
>> 
>> If you would like to work on these issues, let us know.
>
> OK, if not in a hurry and assuming this is not a huge amount of work.
> I also need to look into the build arch so that completely understand
> your 'the default this binary will pick', till now I don't.
>
> Another concern is that I'm not a native English speaker, so those
> description words may not be that apt and concise.

Imperfect English can be addressed in review.  Can be inefficient when
most of the work is English rather than code.  But if you want to try
anyway, go right ahead regardless.

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