configure question (AC_SUBST)

[Stéphane Genaud <genaud icps u-strasbg fr>]

Hi,

I am learning the configure and build GNU tools to package a Gnome app.
I don't really understand how to control the exportation of some 
variables like DATADIR to my gnome program. (i want

In Havoc's book (http://developer.gnome.org/doc/GGAD/z70.html),
some such variables are defined. However if i try to include
DATADIR as well, then gcc passes it twice as -D arg, i.e. , i have
gcc -DDATADIR=\"\" ... -DDATADIR=\"somedir\", and a warning is issued.

I dont know which is the correct way to do this. 

I thought AC_SUBST($datadir) in configure.in was the solution it 
didn't work as well : no DATADIR neither in config.h nor in the -D
flags.

Can someone explain ?

Thanks very much.


Stéphane Genaud.