Re: installing config.h

[Guido Draheim]

Es schrieb "Schleicher Ralph (LLI)":
> 
> Waldemar Rosenbach <address@hidden> writes:
> 
> > But what is the best way to deal with the platform depend stuff in the
> > interface?
> 
> A platform independent interface!
> 

among the problems of ac_create_config_h:
* some ac-checks will check the compiler, not the system
   and some of these are dependent on cflags.
* some ac-checks only target the configuration at build-time
   after installing it, packaging it (into an rpm), and
   copying it to another system, the defs do not hold anymore
   due to missing extension packages.
* some ac-checks define missing things, most prominently the
   ones for off_t and const.

how to handle them:
* place an pkg-conf.h along with the generated pkg-config.h,
   which includes the latter, and all the other headers
   include pkg-conf.h. This pkg-conf.h can include a lot
   of things to get platform independence - yet it turns out
   that this pkg-conf.h is _magnitudes_ easier to write if you
   can start off with a generated pkg-config.h
* just be aware of build-time of the original package and the
   time that third-party software includes them. Perhaps use a 
   magic define for it. It is of _great_ help to have the 
   build-time config of your library automatically coded in an 
   installed header file, far better than a pkg-config-cflags 
   to push them into a third party compile. Verrry useful.

what's not a problem of ac_create_config_
* installing for multiple builds, or the problem of some
   local build config.h
* lib dependencies needed to be pushed through to third party
   software, as per means of a pkg-config-libs.