Cross Compiling Windows Application and DLLs in (Arch) Linux

Cross compiling 32-bit and 64-bit Windows application in Linux is much easier these days than in the past. Thanks to the Mingw-w64 project.  It's even a little more easier in Arch Linux because most of what you need--including extensive amount of libraries--are already in AUR. For starter, install the cross compiler: https://www.archlinux.org/packages/community/x86_64/mingw-w64-gcc/. Then you can continue to install all other stuff (libraries and their dependencies) that you need. In most cases, you can just build and install the package by using the PKGBUILD file from AUR directly (via: cd ${src_dir}; makepkg -sri ). However, in some cases, you need to make adjustment(s) to the PKGBUILD file.

Let's focus on mingw-w64 in Arch Linux. There are several important matters that you need to take care of to cross compile opensource projects that uses Cmake in Arch Linux to build Windows executables and DLLs:

• Opensource projects that uses CMAKE build system, need to use the mingw-w64-specific cmake (look at the example PKGBUILD for cmake below).
• You need to set the include path to the cross compiler toolchain environment include path, not the host include path. 

This is an example PKGBUILD file for a simple Helloworld application that uses boost. It assumes that you have build and install the cross compiled boost DLL in your Arch Linux mingw-w64 environment.

#!/bin/bash

_architectures="x86_64-w64-mingw32 i686-w64-mingw32"

rm -rvf build-*

for _arch in ${_architectures}; do
 mkdir -p build-${_arch} && pushd build-${_arch}
 CMAKE_INCLUDE_PATH="/usr/"${_arch}"/include"
 echo "CMAKE_INCLUDE_PATH = "${CMAKE_INCLUDE_PATH}
 export CMAKE_INCLUDE_PATH
   ${_arch}-cmake ..
 make VERBOSE=1
 popd
done 

The example above is the PKGBUILD file for the sample Helloworld project. You can clone the project over at: https://bitbucket.org/pinczakko/cross_hello_world.

There are also some things to take care if you cross compile opensource projects that uses autotools in Arch Linux to build Windows executables and DLLs:

• Opensource projects that uses autotools build system, need to use the mingw-w64-specific configure script (look at the example PKGBUILD for configure below).
• In some cases, you need to "fool" the libtool script to pass the "dynamic/static library integrity" check. You don't need to be afraid with this step because you could always use Linux file utility to verify the compiler output along with wine before testing/using it in real Windows installation.

This is an example PKGBUILD file for popt library:

# Maintainer: Sebastian Morr 
# Modified by Pinczakko for Mingw-w64 cross compilation to 64-bit Windows

pkgname=mingw-w64-popt
_pkgname=popt
pkgver=1.16
pkgrel=1
arch=('any')
pkgdesc="A commandline option parser (mingw-w64)"
makedepends=('mingw-w64-gcc')
license=('custom')
url="http://rpm5.org"
options=(!strip !buildflags staticlibs)
source=("http://rpm5.org/files/${_pkgname}/${_pkgname}-${pkgver}.tar.gz"
        "0001-nl_langinfo.mingw32.patch"
        "197416.all.patch"
        "217602.all.patch"
        "278402-manpage.all.patch"
        "318833.all.patch"
        "356669.all.patch"
        "367153-manpage.all.patch"
        "get-w32-console-maxcols.mingw32.patch"
        "no-uid-stuff-on.mingw32.patch"
        )
sha1sums=('cfe94a15a2404db85858a81ff8de27c8ff3e235e'
          '62640c0a0845cea5f3cd5646d26fd681ea36cadf'
          'bd7c8872f0bb80ec2a8b78596eb3ba5706795133'
          '977fbbe108cf817103f706dd314236e6bace7557'
          '18d169ff43b6ef4ee613272fdb2bbdc01df1f166'
          'a446c763439fe97459c6ea9bea22054a69ea9cc6'
          '2664b32cd6882e3c7da2d1ed3d40b14807a2c604'
          '63e5fdae8160445794458b03fc5a61e7354efada'
          '6599adf3797d7bfb4534bc910372c431fc0efced'
          '4c3b7b302044bd45decec78f7f7d4ece15d9f3f7')

_architectures="i686-w64-mingw32 x86_64-w64-mingw32"

prepare() {
  cd "$srcdir/${_pkgname}-$pkgver"
  patch -p1 -i ../0001-nl_langinfo.mingw32.patch
  patch -p1 -i ../197416.all.patch
  patch -p1 -i ../217602.all.patch
  patch -p1 -i ../278402-manpage.all.patch
  patch -p1 -i ../318833.all.patch
  patch -p1 -i ../356669.all.patch
  patch -p1 -i ../367153-manpage.all.patch
  patch -p1 -i ../get-w32-console-maxcols.mingw32.patch
  patch -p1 -i ../no-uid-stuff-on.mingw32.patch
}

build() {
  # We assume that libtool check on 64-bit Windows DLL is broken
  # in mingw-w64 Linux cross compiler. So, force it to pass all checks
  export lt_cv_deplibs_check_method='pass_all'

  cd "$srcdir/${_pkgname}-$pkgver"
  for _arch in ${_architectures}; do
    mkdir -p build-${_arch} && pushd build-${_arch}
 ${_arch}-configure --enable-shared --enable-static 
    make
 popd
  done
}

package () {
  for _arch in ${_architectures}; do
    cd "${srcdir}/${_pkgname}-${pkgver}/build-${_arch}"
    make install DESTDIR="${pkgdir}"
    rm -rf "${pkgdir}/usr/${_arch}/share/man"
    ${_arch}-strip -x -g "${pkgdir}/usr/${_arch}/bin/"*.dll
    ${_arch}-strip -g "${pkgdir}/usr/${_arch}/lib/"*.a
  done

  install -D -m644 "${srcdir}/${_pkgname}-${pkgver}/COPYING" "$pkgdir/usr/share/licenses/$pkgname/LICENSE"
}

You can clone the files required to "cross build" popt library at: https://bitbucket.org/pinczakko/cross_mingw-w64-popt.

Hopefully, this is useful for those developing Windows application in Linux.