Once more cross compilation

[Fred Kiefer]

I did not get any responce on my last mail on cross compilation. Perhaps 
this time, as I will try to male more concret proposals.

As I stated in the last mail I think that GNUstep make mixes up the 
three different computer system involved in a cross compilcation. There 
are BUILD, HOST and TARGET. The first and the last are easy to explain. 
BUILD is the system where the compilcation is run and TARGET is the 
system where the result of the application will be used. HOST is the 
system where the result of the compilation will be used. Normally HOST 
and TARGET are the same. The only difference is when building a cross 
compiler HOST will be the system the cross compiler runs on and TARGET 
the system where the generated code will run.

A few examples:
- Most often all three systems are the same.
- When compiling for MinGW in a Cygwin environment BUILD and HOST are 
Cygwin whereas Target is MINGW.
- When compiling GNUstep on a Intel Linux machine to run it on a Zaurus 
ARM processor BUILD is x86-* and HOST and Target both are arm-*.

And in the last case GNUstep goes wrong. There are a few obvious 
problems in the make package. For example target.make tests on line 1010 
for GNUSTEP_HOST_CPU, where obviously GNSUSTEP_TARGET_CPU should be 
used. But this is only a minor problem, compared to the fact that I 
think almost everywhere in the GNUstep make files and make helpers that 
BUILD should be used in place of HOST. For example ld_lib_path.sh uses 
only HOST, but never BUILD to determine and even common.make uses 
$(GNUSTEP_MAKEFILES)/$(GNUSTEP_HOST_CPU)/$(GNUSTEP_HOST_OS)/which_lib to 
find which GNUstep libraries to link. Of course this fails as soon as 
HOST!=BUILD.
When cross compiling GNUstep you first build make for the BUILD and than 
for the TARGET, so this would work with HOST replaced by BUILD. And this 
is what I suggest, replacing HOST with BUILD in most make files. As I 
seem to be the only one trying to cross compile GNUstep, I will make 
these changes myself, if nobody opposes.

Fred