ci: add flang

.github/workflows/ci_cmake.yml

@@ -18,7 +18,7 @@ on:
 
 jobs:
 
-  linux_macos:
+  gcc-new:
     runs-on: ${{ matrix.os }}
     timeout-minutes: 10
 
@@ -46,6 +46,28 @@ jobs:
     - run: cmake --workflow --preset default
 
 
+  linux-flang:
+    runs-on: ubuntu-24.04
+    timeout-minutes: 15
+
+    strategy:
+      matrix:
+        clang-version: [18]
+
+    env:
+      CC: clang-${{ matrix.clang-version }}
+      CXX: clang++-${{ matrix.clang-version }}
+      FC: flang-new
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: install Flang
+      run: sudo apt install --no-install-recommends flang
+
+    - run: cmake --workflow --preset default
+
+
   gcc-old:
     runs-on: ${{ matrix.os }}
     timeout-minutes: 10