[Coin-discuss] Cross-compiling COIN projects (Osi)

[Sebastian Nowozin]

Hello Andreas,

Sebastian Nowozin wrote:

> thanks for your answer, I will try to use
> 
> ADDCXXFLAGS=-m64 ./configure --host ""
> 
> tomorrow.  The problem with with x86_64 target is that the same
> compiler binary is used, whereas for normal cross compilation the
> compiler binary has a prefix, and is named such as "arm-linux-gcc".
> Maybe somebody here figured already how to cross compile.

Does not work, I used the following line to try to compile Osi 0.97.1 on 
a x86 32bit Ubuntu host:

COIN_SKIP_PROJECTS="DyLP" CXXFLAGS="-m64" CFLAGS="-m64" FFLAGS="-m64" 
ADD_CFLAGS="-m64" ADD_CXXFLAGS="-m64" ADD_FFLAGS="-m64" ./configure 
--host "" --prefix=/tmp/coin-osi-0.97.1-amd64 --without-dylp

The result is an immediate (after less than 10 lines of configure output):

checking whether the C compiler works... configure: error: cannot run C 
compiled programs.
If you meant to cross compile, use '--host'.

Now, the problem is, that there is no 64 bit cross compiler, because gcc 
can cross compile with -m64 and -m32 on all modern Linux distributions.

Also, it seems that even without cross compiling, ADD_CXXFLAGS is 
ignored and I do not see "-m64" in the calls to g++.

Sebastian