Support null value in CUDA array interface.

.clang-format

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.github/workflows/jvm_tests.yml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [windows-latest, ubuntu-latest]
+        os: [windows-latest, ubuntu-latest, macos-10.15]
 
     steps:
     - uses: actions/checkout@v2

.github/workflows/main.yml

@@ -21,10 +21,7 @@ jobs:
         submodules: 'true'
     - name: Install system packages
       run: |
-        # Use libomp 11.1.0: https://github.com/dmlc/xgboost/issues/7039
-        wget https://raw.githubusercontent.com/Homebrew/homebrew-core/679923b4eb48a8dc7ecc1f05d06063cd79b3fc00/Formula/libomp.rb -O $(find $(brew --repository) -name libomp.rb)
         brew install ninja libomp
-        brew pin libomp
     - name: Build gtest binary
       run: |
         mkdir build

.github/workflows/python_tests.yml

@@ -17,10 +17,7 @@ jobs:
     - name: Install osx system dependencies
       if: matrix.os == 'macos-10.15'
       run: |
-        # Use libomp 11.1.0: https://github.com/dmlc/xgboost/issues/7039
-        wget https://raw.githubusercontent.com/Homebrew/homebrew-core/679923b4eb48a8dc7ecc1f05d06063cd79b3fc00/Formula/libomp.rb -O $(find $(brew --repository) -name libomp.rb)
         brew install ninja libomp
-        brew pin libomp
     - name: Install Ubuntu system dependencies
       if: matrix.os == 'ubuntu-latest'
       run: |
@@ -45,13 +42,13 @@ jobs:
         cd ..
         python -c 'import xgboost'
 
-  python-tests:
+  python-tests-on-win:
     name: Test XGBoost Python package on ${{ matrix.config.os }}
     runs-on: ${{ matrix.config.os }}
     strategy:
       matrix:
         config:
-          - {os: windows-2016, compiler: 'msvc', python-version: '3.8'}
+          - {os: windows-latest, python-version: '3.8'}
 
     steps:
     - uses: actions/checkout@v2
@@ -62,7 +59,7 @@ jobs:
       with:
         auto-update-conda: true
         python-version: ${{ matrix.config.python-version }}
-        activate-environment: win64_test
+        activate-environment: win64_env
         environment-file: tests/ci_build/conda_env/win64_cpu_test.yml
 
     - name: Display Conda env
@@ -71,13 +68,12 @@ jobs:
         conda info
         conda list
 
-    - name: Build XGBoost with msvc
+    - name: Build XGBoost on Windows
       shell: bash -l {0}
-      if: matrix.config.compiler == 'msvc'
       run: |
         mkdir build_msvc
         cd build_msvc
-        cmake .. -G"Visual Studio 15 2017" -DCMAKE_CONFIGURATION_TYPES="Release" -A x64 -DGOOGLE_TEST=ON  -DUSE_DMLC_GTEST=ON
+        cmake .. -G"Visual Studio 17 2022" -DCMAKE_CONFIGURATION_TYPES="Release" -A x64 -DGOOGLE_TEST=ON  -DUSE_DMLC_GTEST=ON
         cmake --build . --config Release --parallel $(nproc)
 
     - name: Install Python package
@@ -92,3 +88,55 @@ jobs:
       shell: bash -l {0}
       run: |
         pytest -s -v ./tests/python
+
+  python-tests-on-macos:
+    name: Test XGBoost Python package on ${{ matrix.config.os }}
+    runs-on: ${{ matrix.config.os }}
+    strategy:
+      matrix:
+        config:
+          - {os: macos-10.15, python-version "3.8" }
+
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        submodules: 'true'
+
+    - uses: conda-incubator/setup-miniconda@v2
+      with:
+        auto-update-conda: true
+        python-version: ${{ matrix.config.python-version }}
+        activate-environment: macos_test
+        environment-file: tests/ci_build/conda_env/macos_cpu_test.yml
+
+    - name: Display Conda env
+      shell: bash -l {0}
+      run: |
+        conda info
+        conda list
+
+    - name: Build XGBoost on macos
+      shell: bash -l {0}
+      run: |
+        brew install ninja
+
+        mkdir build
+        cd build
+        # Set prefix, to use OpenMP library from Conda env
+        # See https://github.com/dmlc/xgboost/issues/7039#issuecomment-1025038228
+        # to learn why we don't use libomp from Homebrew.
+        cmake .. -GNinja -DGOOGLE_TEST=ON -DUSE_DMLC_GTEST=ON -DCMAKE_PREFIX_PATH=$CONDA_PREFIX
+        ninja
+
+    - name: Install Python package
+      shell: bash -l {0}
+      run: |
+        cd python-package
+        python --version
+        python setup.py bdist_wheel --universal
+        pip install ./dist/*.whl
+
+    - name: Test Python package
+      shell: bash -l {0}
+      run: |
+        pytest -s -v ./tests/python

.github/workflows/python_wheels.yml

@@ -0,0 +1,38 @@
+name: XGBoost-Python-Wheels
+
+on: [push, pull_request]
+
+jobs:
+  python-wheels:
+    name: Build wheel for ${{ matrix.platform_id }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        include:
+        - os: macos-latest
+          platform_id: macosx_x86_64
+        - os: macos-latest
+          platform_id: macosx_arm64
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        submodules: 'true'
+    - name: Setup Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: '3.9'
+    - name: Build wheels
+      run: bash tests/ci_build/build_python_wheels.sh ${{ matrix.platform_id }} ${{ github.sha }}
+    - name: Extract branch name
+      shell: bash
+      run: echo "##[set-output name=branch;]$(echo ${GITHUB_REF#refs/heads/})"
+      id: extract_branch
+      if: github.ref == 'refs/heads/master' || contains(github.ref, 'refs/heads/release_')
+    - name: Upload Python wheel
+      if: github.ref == 'refs/heads/master' || contains(github.ref, 'refs/heads/release_')
+      run: |
+        python -m pip install awscli
+        python -m awscli s3 cp wheelhouse/*.whl s3://xgboost-nightly-builds/${{ steps.extract_branch.outputs.branch }}/ --acl public-read
+      env:
+        AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID_IAM_S3_UPLOADER }}
+        AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY_IAM_S3_UPLOADER }}