C/C++/Rust toolchain for Windows

In Linux, GCC is included in the OS as a system compiler, but in Windows, it is necessary to install a compiler separately from the OS.

If software development itself is your business, you should not be stingy and purchase Visual Studio Pro or subscribe to MSDN subscription. However, it would be a waste to subscribe to MSDN if you just want to write some code to compile the results of an experiment or create a simple business improvement tool for internal use. This is a tip for such people.

MSVC license issue

MSVC (Microsoft Visual C++) is a genuine Microsoft compiler, but the conditions under which it can be used are complicated. The following is an overview as of Visual Studio 2022. For the exact conditions of use, please check the license term by yourself.

  • If you use Visual Studio 2017 Express, there are few restrictions. However, Visual Studio 2017 is the final version, and it is no longer provided.
  • For purely personal use, Visual Studio 2022 Community can be used.
  • If you use Visual Studio 2022 Community in an organization, there are restrictions such as a limit of 5 users, and it is difficult to use it in the workplace with proper license management.
    • It is also difficult to apply the OSS exception clause properly.

Visual Studio 2017 Express for Windows Desktop

If you don't want to sign an MSDN contract, one option is to use Express, which has fewer license restrictions. Download and install Visual Studio Express 2017 for Desktop installer and Build Tools installer. Download and install Visual Studio Express 2017 for Desktop installer and Build Tools installer.

If you want to use Rust together, you can install the x86_64-pc-windows-msvc version of the Rust compiler. (rustup-init will install this automatically)

llvm-mingw toolchain

As an alternative to MSVC, we recommend the LLVM MinGW toolchain.

This toolchain uses the libraries included in MinGW, the Windows version of GCC, and replaces the MinGW compiler with LLVM Clang. It has advantages over MSVC for cross-platform development.

  • Compared to MSVC
    • Free & open source, so it can be used freely.
    • Clang is also available for Linux and Mac, so you can unify compilers if you plan to write code for multiple platforms.
    • It is easy to cross-compile Windows target on a Linux host. This is especially useful for building CI environments.
  • Compared to GCC MinGW
    • LLVM MinGW uses ucrt (Universal C Runtime) which is standard since Windows 10 as C runtime, so there is no problem even if combined with DLLs built with recent MSVC.
    • Features not available in MinGW GCC, such as thread local storage, are also available.
    • The aarch64-pc-windows target, which is not supported by GCC, can also be used.

How to use LLVM MinGW

Just extract the ZIP file and set the PATH environment variable.

  • (1) Get llvm-mingw-*-ucrt-x86_64.zip (AMD, Intel PC) or llvm-mingw-*-ucrt-aarch64.zip (ARM64 PC) from the LLVM MinGW release page.
  • (2) Extract the contents of the ZIP (any location is fine)
    • Assuming you have C:\opt\llvm-mingw\bin\x86_64-w64-mingw32-clang.exe as this example)
  • (3) Set environment variables PATH=C:\opt\llvm-mingw\bin;<other PATHs>

Now you can compile from console as follows.

C:\somewhere> x86_64-w64-mingw32-clang.exe -o hello.exe hello.c
C:\somewhere> hello.exe
Hello, World!

Build tools such as MSBuild included in MSVC are not included in LLVM MinGW, so it is better to use them in combination with CMake and others.

Rust *-pc-windows-gnullvm target

Rust *-pc-windows-gnullvm target has been tier 2 since 1.79.0 and can be easily used with LLVM MinGW.

Using Rust + llvm-mingw on Windows host

The procedure is the following 3 steps.

The major version of LLVM used internally by the Rust compiler and the major version of LLVM MinGW must match (can be checked at rustc -V -v ). Rust 1.73-1.77 => LLVM 17, Rust 1.78-1.81 => LLVM 18 , Rust 1.82- => LLVM 19

  • (1) Get Rust compiler from x86_64-pc-windows-gnu with rustup 
    C:\somewhere> rustup-init.exe --default-host x86_64-pc-windows-gnu --target x86_64-pc-windows-gnullvm
...
    • rustup-init explicitly specify x86_64-pc-windows-gnu as the host toolchain. If you do not specify it, x86_64-pc-windows-msvc will be retrieved.
    • --target x86_64-pc-windows-gnullvm (1) It is convenient to retrieve at the same time.
  • (2) Duplicate libgcc*.a to llvm-mingw's library path
  • C:\Users\<username>\.rustup\toolchains\stable-x86_64-pc-windows-gnu\lib\rustlib\x86_64-pc-windows-gnu\lib\self-contained Duplicate libgcc.a, libgcc_eh.a, libgcc_s.a in C:\opt\llvm-mingw\x86_64-w64-mingw32\lib
  • This is a hack for Rust compiler of x86_64-pc-windows-gnu to link libgcc for GCC. It is necessary for compile of build.rs.
  • (3: Optional) Set default target specification in .cargo/config.toml 
    [build]
target = "x86_64-pc-windows-gnullvm"
    .cargo/config.toml If you don't write the setting in [build], specify target at build time and use it. 
    C:\somewhere> cargo build --target x86_64-pc-windows-gnullvm

x86_64-pc-windows-gnu The build will be cross compiled to another x86_64-pc-windows-gnullvm target on the host of As mentioned above, build.rs is compiled by host compiler (-gnu), but the final .exe is compiled by target (-gnullvm).

Using the Windows .msi installer

I think there are few people who install Rust with .msi, in that case, do as follows.

Cross compile on Linux host

To cross compile .exe for Windows target on a Linux host, do the following

  • (1) Get llvm-mingw-*-ucrt-ubuntu-*-x86_64.tar.xz from the llvm-mingw release page.
  • (2) Extract the contents of the ZIP file (any location is fine)
    • The following is an example of the state in which /opt/llvm-mingw/bin/x86_64-w64-mingw32-clang is located.
  • (3) Set environment variables PATH=/opt/llvm-mingw/bin:<other PATHs>
  • (4) Install x86_64-unknown-linux-gnu host toolchain (normal Rust install procedure) 
    $ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
  • (5) Add x86_64-pc-windows-gnullvm with rustup 
     $ rustup target add x86_64-pc-windows-gnullvm

Rust cross compile as follows

$ cargo build --target x86_64-pc-windows-gnullvm

This will generate a Windows .exe.