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

Quoting Junio C Hamano [off-list ref]:

SZEDER Gábor [off-list ref] writes:

quoted

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.