Change GitHub build process and switch to clang on MacOSX

Author: andreArtelt

.github/workflows/build_test.yml

@@ -8,49 +8,67 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-latest, windows-latest, macos-15-intel, macos-latest]
-        include:
-          - os: macos-15-intel
-            c_compiler: gcc-15
-          - os: macos-latest
-            c_compiler: gcc-15
+        os:
+          - ubuntu-latest
+          - windows-latest
+          - macos-15-intel
+          - macos-15
 
     steps:
       - uses: actions/checkout@v4
 
-      # Used to host cibuildwheel
       - uses: actions/setup-python@v5
         with:
           python-version: "3.11"
 
-      - name: Install gcc on macOS
-        if: runner.os == 'macOS'
-        run: brew install gcc@15
-
       - name: Install libomp on macOS
         if: runner.os == 'macOS'
         run: brew install libomp
 
+      - name: Export libomp paths on macOS
+        if: runner.os == 'macOS'
+        run: |
+          echo "LIBOMP_PREFIX=$(brew --prefix libomp)" >> "$GITHUB_ENV"
+
       - name: Install cibuildwheel
         run: python -m pip install cibuildwheel
 
       - name: Build wheels
         env:
-          CIBW_ENVIRONMENT_MACOS: CC=gcc-15 MACOSX_DEPLOYMENT_TARGET=26.0
+          CIBW_ENVIRONMENT_LINUX: >-
+            CFLAGS=-fopenmp
+            CXXFLAGS=-fopenmp
+            LDFLAGS=-fopenmp
+          CIBW_ENVIRONMENT_WINDOWS: >-
+            CL=/openmp
+          CIBW_ENVIRONMENT_MACOS: >-
+            CC=clang
+            CXX=clang++
+            MACOSX_DEPLOYMENT_TARGET=15.0
+            CPPFLAGS=-I${{ env.LIBOMP_PREFIX }}/include
+            CFLAGS=-Xpreprocessor\ -fopenmp
+            CXXFLAGS=-Xpreprocessor\ -fopenmp
+            LDFLAGS=-L${{ env.LIBOMP_PREFIX }}/lib\ -Wl,-rpath,${{ env.LIBOMP_PREFIX }}/lib\ -lomp
         run: python -m cibuildwheel --output-dir wheelhouse
 
-      - name: Test on all platforms except MacOS
+      - name: Test on all platforms except macOS
         if: runner.os != 'macOS'
         run: |
           python -m pip install -r REQUIREMENTS.txt
           python -m pip install -e .
           python -m pip install -r REQUIREMENTS-DEV.txt
           pytest -v
 
-      - name: Test on MacOS
+      - name: Test on macOS
         if: runner.os == 'macOS'
         env:
-          CC: gcc-15
+          CC: clang
+          CXX: clang++
+          MACOSX_DEPLOYMENT_TARGET: "15.0"
+          CPPFLAGS: -I${{ env.LIBOMP_PREFIX }}/include
+          CFLAGS: -Xpreprocessor -fopenmp
+          CXXFLAGS: -Xpreprocessor -fopenmp
+          LDFLAGS: -L${{ env.LIBOMP_PREFIX }}/lib -Wl,-rpath,${{ env.LIBOMP_PREFIX }}/lib -lomp
         run: |
           python -m pip install -r REQUIREMENTS.txt
           python -m pip install -e .

pyproject.toml

@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools", "numpy"]
+requires = ["setuptools", "wheel", "numpy"]
 build-backend = "setuptools.build_meta"
 
 [project]
@@ -45,7 +45,7 @@ find = {}
 
 [tool.setuptools]
 ext-modules = [
-  {name = "epanet", extra-compile-args = ["-fopenmp"], extra-link-args = ["-fopenmp"], include-dirs=["epanet-src/include", "epanet-src/", "epanet-msx-src/include", "epanet-msx-src/",
+  {name = "epanet", include-dirs=["epanet-src/include", "epanet-src/", "epanet-msx-src/include", "epanet-msx-src/",
                                   "python-extension", "epanet_plus/include", "epanet-src/util"], sources = ["python-extension/pyepanet.c",
                                   "python-extension/pyepanet2.c", "python-extension/pyepanetmsx.c", "python-extension/pyepanet_plus.c",
                                   "python-extension/ext.c", "epanet_plus/epanet_plus.c", "epanet-src/epanet2.c", "epanet-src/hydcoeffs.c",