Clang C++ Cross Compiler - Generating Windows Executable from Mac OS X

Question

I have created a C++ application using Xcode on my Mac using the Clang compiler.

I want to compile my source files to create an executable that can be ran on a wind

Answer 1

Here are step-by-step instructions for building a Hello World .exe using llvm/clang on Mac OS X.

Cross-compile Hello World for Windows using Clang/LLVM on Mac OS X

Install llvm with homebrew. This will include the clang and the llvm linker.

brew install llvm

You'll need access to Visual Studio C++ libraries and headers, which are available through Visual Studio 2017 on a Windows 10 Virtual Machine (VM) or on a Windows 10 Computer. Install Visual Studio on Window, and include the following 'Individual Components' through the Visual Studio Installer:

• Windows Universal CRT SDK
• Windows Universal C Runtime
• Windows 10 SDK (X.X.X.X) for UWP: C++
• VC++ 2017 vXXX toolset (x86,x64)
• Visual C++ 2017 Redistributable Update
• C++/CLI support

Get access to the MSVC libraries and headers from your Mac.

• (Option 1) Use your Windows VM and create a shared folder between host and guest.
• (Option 2) Create a remote share on your Windows computer and connect to it from your Mac.
• (Option 3) Copy the libraries and headers to your Mac, following any licensing terms.

Find the specific directories on your llvm+MSVC install that correspond to the following:

// LLVM:
INCLUDES: /usr/local/Cellar/llvm/5.0.0/include

// MSVC:
INCLUDES: "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.11.25503\include"
LIBS: "C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.11.25503\lib\x86"

// C Runtime Library (CRT):
INCLUDES: "C:\Program Files (x86)\Windows Kits\10\Include\10.0.15063.0\ucrt"
LIBS: "C:\Program Files (x86)\Windows Kits\10\Include\10.0.15063.0\ucrt"

// User-Mode Library (UM):
INCLUDES: "C:\Program Files (x86)\Windows Kits\10\Include\10.0.15063.0\um"
LIBS: "C:\Program Files (x86)\Windows Kits\10\Lib\10.0.15063.0\um\x86"

// 'Shared' includes:
INCLUDES: "C:\Program Files (x86)\Windows Kits\10\Include\10.0.15063.0\shared"

// WinRT includes:
INCLUDES: "C:\Program Files (x86)\Windows Kits\10\Include\10.0.15063.0\winrt"

// Figure out your MSC 'version', e.g.
Visual C++ 2012 (11.0)   -->     MSC_VER=1700
Visual C++ 2013 (12.0)   -->     MSC_VER=1800
Visual C++ 2015 (14.0)   -->     MSC_VER=1900
Visual C++ 2017 (15.0)   -->     MSC_VER=1910

Create your Hello World src:

// hello.cc

#include 

int main(int argc, char* argv[]) {
  printf("Hello, World!\n");

  return 0;
}

Compile with clang:

clang -target i686-pc-win32 \
  -fms-compatibility-version=19 \
  -fms-extensions \
  -fdelayed-template-parsing \ 
  -fexceptions \
  -mthread-model posix \
  -fno-threadsafe-statics \
  -Wno-msvc-not-found \
  -DWIN32 \
  -D_WIN32 \
  -D_MT \
  -D_DLL \
  -Xclang -disable-llvm-verifier \
  -Xclang '--dependent-lib=msvcrt' \
  -Xclang '--dependent-lib=ucrt' \
  -Xclang '--dependent-lib=oldnames' \
  -Xclang '--dependent-lib=vcruntime' \
  -D_CRT_SECURE_NO_WARNINGS \
  -D_CRT_NONSTDC_NO_DEPRECATE \
  -U__GNUC__ \
  -U__gnu_linux__ \
  -U__GNUC_MINOR__ \
  -U__GNUC_PATCHLEVEL__ \
  -U__GNUC_STDC_INLINE__  \
  -I/usr/local/Cellar/llvm/5.0.0/include \
  -I/c/Program\ Files\ (x86)/Microsoft\ Visual\ Studio/2017/Community/VC/Tools/MSVC/14.11.25503/include \
  -I/c/Program\ Files\ (x86)/Windows\ Kits/10/Include/10.0.15063.0/ucrt \
  -I/c/Program\ Files\ (x86)/Windows\ Kits/10/Include/10.0.15063.0/shared \
  -I/c/Program\ Files\ (x86)/Windows\ Kits/10/Include/10.0.15063.0/winrt \
  -c hello.cc -o hello.o

Link with the lld linker, driven by clang:

clang -fuse-ld=lld -target i686-pc-win32 -Wl,-machine:x86 -fmsc-version=1900 \
  -o hello.exe hello.o \
  -L/external/code8-cc/cc/msvctoolchain/x86/lib/msvc \
  -L/external/code8-cc/cc/msvctoolchain/x86/lib/um \
  -L/code8-cc/cc/msvctoolchain/x86/lib/ucrt
  -nostdlib -lmsvcrt -Wno-msvc-not-found 

Copy hello.exe to your Windows computer or Windows VM and run in PowerShell:

.\hello.exe

To build 64-bit versions, change to '-target x86_64-pc-win32', '-Wl,-machine:x64', and link to x64 libraries.