Re: [RFC PATCH] gc --auto: don't lie about running in background on Windows

["SZEDER Gábor" <szeder@ira.uka.de>]

Quoting Junio C Hamano <gitster@pobox.com>:

> SZEDER Gábor <szeder@ira.uka.de> writes:
>
>> Arguably this helper function could be just a simple variable.  I
>> opted for a function because:
>>
>>   - I preferred a single '#ifdef NO_POSIX_GOODIES', and putting a
>>     static variable so near to EOF felt just wrong.  (And this is why
>>     it's not an inline-able function defined in a header file.)
>>
>>   - currently we know already at compile time that Windows can't
>>     daemonize, but in the future we might want to extend this helper
>>     function to perform some runtime checks, too.  But this is perhaps
>>     like preparing for crossing a bridge where we'll never get to.
>
> Alternatively, the implementation of daemonize() and can_daemonize()
> can live in compat/ and have the #ifdef switch in git-compat-util.h,
> e.g. something along the lines of these:
>
> 	<< git-compat-util.h >>
> 	... after conditional inclusion of compat/mingw.h ...
> 	#ifndef can_daemonize
>         #define can_daemonize() 1
> 	#endif
>
> 	<< compat/mingw.h >>
> 	#define can_daemonize() 0
> 	#define daemonize() mingw_daemonize()
>
> 	<< setup.c >>
>         ...
>         #ifndef NO_POSIX_GOODIES
>         int daemonize(void)
>         {
>             ... no ifdef around here ...
> 	}
> 	#endif

config.mak.uname sets NO_POSIX_GOODIES only for Windows builds, but
NO_POSIX_GOODIES doesn't sound Windows-specific at all.  Currently if
somebody were to decide to build with NO_POSIX_GOODIES=UnfortunatelyYes,
then he would get a working git in the end, even on non-Windows
platforms.  With the proposed alternative above we would only provide an
alternative daemonize() implementation for MINGW, breaking the build of
those setting NO_POSIX_GOODIES by themselves.

I don't know whether there are platforms out there besides Windows that
need the NO_POSIX_GOODIES treatment, but we don't explicitly support
them in config.mak.uname, or people who for whatever reason build with
this knob turned on.