setup-masm

A GitHub Action to facilitate configuring MASM (Microsoft Macro Assembler) in the workflow PATH to use x64, x86 and ARM64 assembly in Win32 applications.

Description

This action helps set up MASM into the PATH for later usage in your GitHub Actions workflows. It's particularly useful for projects that require assembly language programming on Windows platforms.

Usage

Add the following step to your workflow:

- uses: glslang/setup-masm@v1.4

Runner compatibility

This action supports Visual Studio 2022 and Visual Studio 2026. It uses vswhere to locate whichever VS version is installed on the runner, so it works without any configuration changes as GitHub migrates windows-latest to VS 2026 (rollout June 8–15, 2026).

Runner label	Visual Studio
windows-2022	VS 2022
windows-2025-vs2026 / windows-latest (after June 15, 2026)	VS 2026
windows-11-arm	VS 2022+

Inputs

• vs-version: The version of Visual Studio to use. Defaults to 'latest' (newest installed).
• vs-prerelease: Whether to include prerelease versions of Visual Studio. Defaults to 'false'.
• vs-architecture: By default the action will use the x64 architecture for MASM, but it is possible to target the x86 or arm64 versions instead. Valid input values are 'x64', 'x86' and 'arm64'. Note that the success of these will rely on the runner OS. Defaults to 'x64'.

Outputs

• masmPath: The path to the MASM executable.

PATH environment variable

The MASM path is added to the PATH environment variable.

Example Workflow

name: Build and Test

on:
  push:
    branches: [main]

jobs:
  build:
    runs-on: windows-latest
    steps:
      - uses: actions/checkout@v4
      - uses: microsoft/setup-msbuild@v3
      - uses: glslang/setup-masm@v1.4
        with:
          vs-architecture: 'x86'

This example demonstrates how to set up MASM in a Windows-based workflow, ensuring that the necessary tools are available for building and testing your project.

License

This project is licensed under the MIT License. See the LICENSE file for more details.

Contributing

We welcome contributions! Please read our CONTRIBUTING.md for details on our code of conduct and the process for submitting pull requests.

Contact

For any inquiries, please contact the maintainers of this repository.

Credits

This project was based on microsoft/setup-msbuild. Cursor AI was used to generate code and documentation.