Always use Clang to build our third-party libraries.

Indeed, to build LLVM+Clang on Windows ARM is not possible using MSVC.

Author: agarny

.github/workflows/buildThirdPartyLibrary.yml

@@ -21,19 +21,19 @@ jobs:
         include:
           - name: 'Windows release (Intel)'
             os: windows-latest
-            arch: amd64
+            target_architecture: Intel
             build_type: Release
           - name: 'Windows debug (Intel)'
             os: windows-latest
-            arch: amd64
+            target_architecture: Intel
             build_type: Debug
           - name: 'Windows release (ARM)'
             os: windows-latest
-            arch: amd64_arm64
+            target_architecture: ARM
             build_type: Release
           - name: 'Windows debug (ARM)'
             os: windows-latest
-            arch: amd64_arm64
+            target_architecture: ARM
             build_type: Debug
           - name: 'Linux (Intel)'
             os: ubuntu-20.04
@@ -43,60 +43,42 @@ jobs:
             #       our Python wheels on Linux, we have no choice but to use manylinux_2_28, which relies on a version
             #       of glibc with libpthread, hence getting various messages about __libc_single_threaded being
             #       undefined when trying to build our Python wheels using third-party libraries built on ubuntu-22.04.
+            target_architecture: Intel
             build_type: Release
           - name: 'Linux (ARM)'
             os: ubuntu-latest
-            arch: arm
-            cmake_prereqs: CC=aarch64-linux-gnu-gcc CXX=aarch64-linux-gnu-g++
+            target_architecture: ARM
             build_type: Release
           - name: 'macOS (Intel)'
-            os: macos-13
+            os: macos-latest
+            target_architecture: Intel
             build_type: Release
           - name: 'macOS (ARM)'
             os: macos-latest
+            target_architecture: ARM
             build_type: Release
     env:
       BUILDCACHE_ACCURACY: STRICT
       BUILDCACHE_COMPRESS_FORMAT: ZSTD
       BUILDCACHE_DEBUG: -1
       BUILDCACHE_LOG_FILE: ""
     steps:
+      - name: Check the version of Clang
+        run: clang --version
       - name: Check out libOpenCOR
         uses: actions/checkout@v4
-      - name: Install ARM compiler
-        if: ${{ matrix.arch == 'arm' }}
-        run: |
-          sudo apt update
-          sudo apt install gcc-aarch64-linux-gnu g++-aarch64-linux-gnu
       - name: Install CMake and Ninja
         uses: lukka/get-cmake@latest
       - name: Install buildcache
         uses: cscouto/buildcache-action@v1
         with:
           cache_key: libraries-${{ matrix.os }}-${{ matrix.shared_libs }}
-      - name: Configure MSVC (to build an Intel-based version of llvm-tblgen and clang-tblgen)
-        if: ${{ (runner.os == 'Windows') && (matrix.arch == 'amd64_arm64') }}
-        uses: ilammy/msvc-dev-cmd@v1
-        with:
-          arch: amd64
-      - name: Build llvm-tblgen and clang-tblgen
-        if: ${{ (((runner.os == 'Windows') && (matrix.arch == 'amd64_arm64')) || ((runner.os == 'Linux') && (matrix.arch == 'arm'))) }}
-        shell: bash
-        run: |
-          source src/3rdparty/LLVMClang/scripts/buildllvmclangtblgen ${{ runner.os == 'Windows' }}
-          echo "DLLVMCLANG_LLVM_TABLEGEN=$DLLVMCLANG_LLVM_TABLEGEN" >> $GITHUB_ENV
-          echo "DLLVMCLANG_CLANG_TABLEGEN=$DLLVMCLANG_CLANG_TABLEGEN" >> $GITHUB_ENV
-      - name: Configure MSVC
-        if: ${{ runner.os == 'Windows' }}
-        uses: ilammy/msvc-dev-cmd@v1
-        with:
-          arch: ${{ matrix.arch }}
       - name: Configure libOpenCOR
         shell: bash
         run: |
           mkdir build
           cd build
-          ${{ matrix.cmake_prereqs }} cmake -G Ninja -DBUILD_TYPE=${{ matrix.build_type }} -DONLY_BUILD_THIRD_PARTY_LIBRARIES=ON -DPREBUILT_${{ inputs.third_party_library_name }}=OFF ${{ env.DLLVMCLANG_LLVM_TABLEGEN }} ${{ env.DLLVMCLANG_CLANG_TABLEGEN }} ..
+          cmake -G Ninja -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ -DTARGET_ARCHITECTURE=${{ matrix.target_architecture }} -DBUILD_TYPE=${{ matrix.build_type }} -DONLY_BUILD_THIRD_PARTY_LIBRARIES=ON -DPREBUILT_${{ inputs.third_party_library_name }}=OFF ${{ env.DLLVMCLANG_LLVM_TABLEGEN }} ${{ env.DLLVMCLANG_CLANG_TABLEGEN }} ..
       - name: Upload library artifact
         if: ${{ !startsWith(github.ref, 'refs/tags/v') }}
         uses: actions/upload-artifact@v4