Cross-compiling from Linux to Windows with MinGW¶

It is possible to cross-build from Linux to Windows using the MinGW cross-compiler. Note that such a compiler won’t be using the MSVC runtime, but the MinGW one, which uses the libstdc++6.dll runtime.

This blog post about Clang in Windows describes the different runtimes for the different Windows subsystems, which is equally applicable to MinGW.

The first step would be to install the compiler. In Debian based systems:

$ sudo apt install gcc-mingw-w64-x86-64-posix
$ sudo apt install g++-mingw-w64-x86-64-posix

If the compiler is installed in the system path, then we could write a profile like:

mingw¶

[settings]
os=Windows
compiler=gcc
compiler.version=10
compiler.cppstd=gnu17
compiler.libcxx=libstdc++11
arch=x86_64
build_type=Release

[buildenv]
CC=x86_64-w64-mingw32-gcc-posix
CXX=x86_64-w64-mingw32-g++-posix

Then, let’s say that we have a basic CMake project, which we can create with the conan new:

$ conan new cmake_lib -d name=mypkg -d version=0.1
$ conan create . -pr=mingw

...
-- Using Conan toolchain: .../conan_toolchain.cmake
-- Conan toolchain: Defining architecture flag: -m64
-- Conan toolchain: C++ Standard 17 with extensions ON
-- The CXX compiler identification is GNU 10.0.0
-- Check for working CXX compiler: /usr/bin/x86_64-w64-mingw32-g++-posix - skipped

mypkg/0.1 (test package): Running CMake.build()
mypkg/0.1 (test package): RUN: cmake --build ...
gcc-10-x86_64-gnu17-release" -- -j8
[ 50%] Building CXX object CMakeFiles/example.dir/src/example.cpp.obj
[100%] Linking CXX executable example.exe
[100%] Built target example

The example.exe will not be executed in the Linux machine, because the test_package contains a if can_run(self) branch to not run it in cross-build scenarios.

We can now take the example.exe and run it in a Windows machine:

mypkg/0.1: Hello World Release!
mypkg/0.1: _M_X64 defined
mypkg/0.1: __x86_64__ defined
mypkg/0.1: _GLIBCXX_USE_CXX11_ABI 1
mypkg/0.1: MSVC runtime: MultiThreadedDLL
mypkg/0.1: __cplusplus201402
mypkg/0.1: __GNUC__10
mypkg/0.1: __MINGW32__1
mypkg/0.1: __MINGW64__1

Note

It is very possible that some recipes in ConanCenter are not prepared to be cross-built from Linux to Windows. The recommended way to build ConanCenter recipes is to build them with MSVC in Windows, as there might be limitations for the specific build-systems of the recipes, and MinGW support is not guaranteed.
Trying to run the executables with some emulators like wine might require extra effort, because the runtime environment is intended to be Windows, and as such a conanrun.bat environment file will be created, but that cannot be executed in Linux. Using configurations like -c tools.build.cross_building:can_run=True -c tools.microsoft.bash:subsystem=mingw -c tools.microsoft.bash:active=True can allow to force the generation and execution of conanrun.sh.