Add cpp linter workflow

.clang-tidy

@@ -0,0 +1,26 @@
+Checks: '-*,clang-diagnostic-*,llvm-*,misc-*,-misc-const-correctness,-misc-unused-parameters,-misc-non-private-member-variables-in-classes,-misc-no-recursion,-misc-use-anonymous-namespace,readability-identifier-naming,-misc-include-cleaner,-llvm-header-guard'
+CheckOptions:
+  - key:             readability-identifier-naming.ClassCase
+    value:           CamelCase
+  - key:             readability-identifier-naming.EnumCase
+    value:           CamelCase
+  - key:             readability-identifier-naming.FunctionCase
+    value:           camelBack
+  # Exclude from scanning as this is an exported symbol used for fuzzing
+  # throughout the code base.
+  - key:             readability-identifier-naming.FunctionIgnoredRegexp
+    value:           "LLVMFuzzerTestOneInput"
+  - key:             readability-identifier-naming.MemberCase
+    value:           CamelCase
+  - key:             readability-identifier-naming.ParameterCase
+    value:           CamelCase
+  - key:             readability-identifier-naming.UnionCase
+    value:           CamelCase
+  - key:             readability-identifier-naming.VariableCase
+    value:           CamelCase
+  - key:             readability-identifier-naming.IgnoreMainLikeFunctions
+    value:           1
+  - key:             readability-redundant-member-init.IgnoreBaseInCopyConstructors
+    value:           1
+  - key:             modernize-use-default-member-init.UseAssignment
+    value:           1

.github/workflows/cpp-linter.yml

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+name: cpp-linter
+
+on:
+  pull_request:
+
+jobs:
+  cpp-linter:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      pull-requests: write
+    defaults:
+      run:
+        shell: bash -el {0}
+    steps:
+      - uses: actions/checkout@v4
+      - name: Setup conda
+        uses: conda-incubator/setup-miniconda@v3
+        with:
+          conda-remove-defaults: true
+      # Install Clang/LLVM using conda
+      - name: Create environment
+        run: |
+          conda install -y -q -c conda-forge \
+            clang=18.1.3 \
+            clangxx=18.1.3 \
+            llvmdev=18.1.3 \
+            lit=18.1.3
+          ln -s ${CONDA_PREFIX}/libexec/llvm/FileCheck ${CONDA_PREFIX}/bin
+      - name: Run cmake to export compilation database
+        run: |
+          mkdir -p build
+          pushd build
+          cmake .. \
+            -DCMAKE_C_COMPILER=clang \
+            -DCMAKE_CXX_COMPILER=clang++ \
+            -DCMAKE_EXPORT_COMPILE_COMMANDS=on
+      - uses: cpp-linter/cpp-linter-action@v2
+        id: linter
+        continue-on-error: true
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          version: 18
+          ignore: .github | tests | scripts
+          style: file
+          tidy-checks: ''
+          database: build
+          lines-changed-only: true
+          format-review: true
+          tidy-review: true
+          passive-reviews: true
+      - name: Check linter status
+        if: steps.linter.outputs.checks-failed != 0
+        run: exit 1