[Freeciv-Dev] Re: (PR#20534) FREECIV_DATA_PATH, ${prefix}, and $datadir

["Jason Dorje Short" <jdorje@xxxxxxxxx>]

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=20534 >

Jason Dorje Short wrote:
> <URL: http://bugs.freeciv.org/Ticket/Display.html?id=20534 >
> 
> I thought I sent this patch already but I can't find it.  Anyway, it 
> needs to be committed to all branches that have configure.ac for freeciv 
> to sucessfully work with recent versions of autoconf.  Read the autoconf 
> manual for more.

http://www.gnu.org/software/autoconf/manual/autoconf-2.57/html_chapter/autoconf_4.html#SEC24

"Most of these variables have values that rely on prefix or exec_prefix. 
It is deliberate that the directory output variables keep them 
unexpanded: typically `@datadir@' will be replaced by `${prefix}/share', 
not `/usr/local/share'."

Thus #define just defines it as ${prefix}/share/freeciv.  But by using 
cflags the expansion is done at compile time, not configure time.  Thus 
you can give a different prefix on the "make" line.

-jason