From: Mauricio Fernandez <mfp@...>
Date: 2006-10-19T03:53:58+09:00
Subject: Re: Cross Compiling Ruby Extension

On Wed, Oct 18, 2006 at 04:58:53PM +0900, Brian Takita wrote:
> Hello,
> 
> I'm attempting to cross compile a ruby extension for Windows from a Linux
> box.
> Im running Ubuntu 6.06, Ruby 1.8.5, and mingw gcc 3.4.4.
> 
> I attempted to follow Mauricio Fernandez's instructions
> http://eigenclass.org/hiki.rb?cross+compiling+rcovrt#f01
> 
> The file compiled but it appears that it is still a Linux binary.
> json_ext.so: ELF 32-bit LSB shared object, Intel 80386, version 1 (SYSV),
> not stripped

You are using mkrf instead of mkmf, so things work a bit differently.

$ cat extconf.rb
require 'rubygems'
require 'mkrf'

dir = File.dirname(__FILE__)
Mkrf::Generator.new('json_ext', "#{dir}/*.c")
$ cat > extconf.rb
require 'mkmf'
create_makefile "json_ext"
$ ruby -I ~/usr/ruby-mingw32/lib/ruby/1.8/i386-mingw32 extconf.rb
/home/batsman/ruby-mingw32/lib/ruby/1.8/i386-mingw32/rbconfig.rb:7: ruby lib version (1.8.4) doesn't match executable version (1.8.5) (RuntimeError)
	from /home/batsman/usr//lib/ruby/1.8/mkmf.rb:4:in `require'
	from /home/batsman/usr//lib/ruby/1.8/mkmf.rb:4
	from extconf.rb:1:in `require'
	from extconf.rb:1

[use vim to edit rbconfig.rb and remove/comment the version check if the
native & cross-compiled ruby version differ]

$ ruby -I ~/ruby-mingw32/lib/ruby/1.8/i386-mingw32/ extconf.rb
creating Makefile
$ make
i586-mingw32msvc-gcc -I. -I/home/batsman/ruby-mingw32/lib/ruby/1.8/i386-mingw32 -I/home/batsman/ruby-mingw32/lib/ruby/1.8/i386-mingw32 -I.  -g -O2   -c json_ext.c
i586-mingw32msvc-gcc -shared -s -Wl,--enable-auto-import,--export-all  -L"/home/batsman/ruby-mingw32/lib" -o json_ext.so json_ext.o  -lmsvcrt-ruby18  -lwsock32
$ file json_ext.so
json_ext.so: MS Windows PE 32-bit Intel 80386 console DLL

-- 
Mauricio Fernandez  -   http://eigenclass.org   -  singular Ruby