---
parent: Setup
nav_order: 2
---

# Building & Testing libcu++

## *nix Systems, Native Build/Test

The procedure is demonstrated for NVCC + GCC in C++11 mode on a Debian-like
Linux systems; the same basic steps are required on all other platforms.

### Step 0: Install Build Requirements

In a Bash shell:

```bash
# Install LLVM (needed for LLVM's CMake modules)
apt-get -y install llvm

# Install CMake
apt-get -y install cmake

# Install the LLVM Integrated Tester (`lit`)
apt-get -y install python-pip
pip install lit

# Env vars that should be set, or kept in mind for use later
export LIBCUDACXX_ROOT=/path/to/libcudacxx # Git repo root.
```

### Step 1: Generate the Build Files

In a Bash shell:

```bash
cd ${LIBCUDACXX_ROOT}
cmake \
    -S ./ \
    -B build \
    -DCMAKE_CXX_COMPILER=$CXX \
    -DCMAKE_CUDA_COMPILER=$TOOLKIT/bin/nvcc \
    -DLIBCUDACXX_ENABLE_LIBCUDACXX_TESTS=ON \
    -DLIBCUDACXX_ENABLE_LIBCXX_TESTS=OFF
```

### Step 2: Build & Run the Tests

In a Bash shell:

```bash
cd ${LIBCUDACXX_ROOT}/build # build directory of this repo
../utils/nvidia/linux/perform_tests.bash --skip-libcxx-tests
```

## *nix Systems, Cross Build/Test

The procedure is demonstrated for NVCC + GCC cross compiler in C++14 mode on a
Debian-like Linux systems targeting an aarch64 L4T system; the same basic steps
are required on all other platforms.

### Step 0: Install Build Prerequisites

Follow Step 0 for \*nix native builds/tests.

### Step 1: Generate the Build Files

In a Bash shell:

```bash
export HOST=executor.nvidia.com
export USERNAME=ubuntu

cd ${LIBCUDACXX_ROOT}
cmake \
  -S ./ \
  -B build \
  -DCMAKE_CUDA_COMPILER=$TOOLKIT/bin/nvcc \
  -DCMAKE_CXX_COMPILER=aarch64-linux-gnu-g++ \
  -DLIBCUDACXX_ENABLE_LIBCUDACXX_TESTS=ON \
  -DLIBCUDACXX_ENABLE_LIBCXX_TESTS=OFF \
  -DLIBCXX_EXECUTOR="SSHExecutor(host='${HOST}', username='${USERNAME}')"
```

Ensure that you can SSH to the target system from the host system without
inputing a password (e.g. use SSH keys).

### Step 2: Build & Run the Tests

Follow Step 2 for \*nix native builds/tests.

## *nix Systems, NVRTC Build/Test

The procedure is demonstrated for NVRTC in C++11 mode on a Debian-like
Linux systems; the same basic steps are required on all other platforms.

### Step 0: Install Build Prerequisites

Follow Step 0 for \*nix native builds/tests.

### Step 1: Generate the Build Files

In a Bash shell:

```bash
cd ${LIBCUDACXX_ROOT}
cmake \
  -S ./ \
  -B build \
  -DCMAKE_CXX_COMPILER=$CC \
  -DCMAKE_CUDA_COMPILER=$TOOLKIT/bin/nvcc \
  -DLIBCUDACXX_ENABLE_LIBCUDACXX_TESTS=ON \
  -DLIBCUDACXX_ENABLE_LIBCXX_TESTS=OFF \
  -DLIBCUDACXX_TEST_WITH_NVRTC=ON
```

### Step 2: Build & Run the Tests

Follow Step 2 for \*nix native builds/tests.

## Windows, Native Build/Test

### Step 0: Install Build Requirements

[Install Python](https://www.python.org/downloads/windows).

Download [the get-pip.py bootstrap script](https://bootstrap.pypa.io/get-pip.py) and run it.

Install the LLVM Integrated Tester (`lit`) using a Visual Studio command prompt:

```bat
pip install lit
```

### Step 0.5: Launching a Build Environment

Visual Studio comes with a few build environments that are appropriate to use.

The `x64 Native Tools Command Prompt` and other similarly named environments will work.

If Powershell is desired, it would be best to launch it from within the native tools. This helps avoid configuration step issues.

### Step 1: Generate the Build Files

In a Visual Studio command prompt:

```bat
set LIBCUDACXX_ROOT=\path\to\libcudacxx # Helpful env var pointing to the git repo root.
cd %LIBCUDACXX_ROOT%

cmake ^
  -S ./ ^
  -B build ^
  -G "Ninja" ^
  -DCMAKE_CXX_COMPILER=cl ^
  -DCMAKE_CUDA_COMPILER=nvcc ^
  -DCMAKE_CUDA_COMPILER_FORCED=ON ^
  -DLIBCUDACXX_ENABLE_LIBCUDACXX_TESTS=ON ^
  -DLIBCUDACXX_ENABLE_LIBCXX_TESTS=OFF
```

### Step 2: Build & Run the Tests

`SM_ARCH` can be set to any integer value (Ex: "80", "86")

```bat
set LIBCUDACXX_SITE_CONFIG=%LIBCUDACXX_ROOT%\build\test\lit.site.cfg
lit %LIBCUDACXX_ROOT%\test -Dcompute_archs=%SM_ARCH% -sv --no-progress-bar
```