Add CMake clang-tidy integration, enable in CI, and fix all clang-tidy errors

.clang-tidy

@@ -0,0 +1,54 @@
+---
+Checks: >
+  -*,
+  bugprone-*,
+  -bugprone-easily-swappable-parameters,
+  -bugprone-unhandled-self-assignment,
+  cert-*,
+  -cert-err33-c,
+  -cert-err34-c,
+  -cert-msc30-c,
+  -cert-msc32-c,
+  -cert-msc50-cpp,
+  -cert-msc51-cpp,
+  -cert-oop54-cpp,
+  clang-analyzer-*,
+  concurrency-*,
+  -concurrency-mt-unsafe,
+  cppcoreguidelines-*,
+  -cppcoreguidelines-avoid-c-arrays,
+  -cppcoreguidelines-avoid-magic-numbers,
+  -cppcoreguidelines-c-copy-assignment-signature,
+  -cppcoreguidelines-non-private-member-variables-in-classes,
+  -cppcoreguidelines-owning-memory,
+  -cppcoreguidelines-pro-bounds-array-to-pointer-decay,
+  -cppcoreguidelines-pro-bounds-constant-array-index,
+  -cppcoreguidelines-pro-bounds-pointer-arithmetic,
+  -cppcoreguidelines-pro-type-member-init,
+  -cppcoreguidelines-pro-type-reinterpret-cast,
+  -cppcoreguidelines-pro-type-vararg,
+  -cppcoreguidelines-special-member-functions,
+  hicpp-*,
+  -hicpp-avoid-c-arrays,
+  -hicpp-explicit-conversions,
+  -hicpp-member-init,
+  -hicpp-no-array-decay,
+  -hicpp-signed-bitwise,
+  -hicpp-special-member-functions,
+  -hicpp-vararg,
+  misc-*,
+  -misc-confusable-identifiers,
+  -misc-include-cleaner,
+  -misc-non-private-member-variables-in-classes,
+  -misc-unconventional-assign-operator,
+  modernize-*,
+  -modernize-avoid-c-arrays,
+  -modernize-use-trailing-return-type,
+  performance-*,
+  portability-*,
+  readability-*,
+  -readability-function-cognitive-complexity,
+  -readability-identifier-length,
+  -readability-magic-numbers
+WarningsAsErrors: '*'
+FormatStyle: file

.github/workflows/ci.yml

@@ -32,7 +32,7 @@ jobs:
 
     steps:
     - name: Install packages
-      run: sudo apt install doctest-dev clang
+      run: sudo apt install doctest-dev clang clang-tidy
       if: matrix.os == 'ubuntu-latest'
 
     - uses: actions/checkout@v4
@@ -47,7 +47,7 @@ jobs:
       working-directory: ${{github.workspace}}/build/${{ matrix.build_type }}
       run: |
         if [ "$RUNNER_OS" == "Linux" ]; then
-          cmake $GITHUB_WORKSPACE -DCMAKE_CXX_COMPILER=${{ matrix.compiler }} -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} -DTESTS=ON -DOPENSSL=ON
+          cmake $GITHUB_WORKSPACE -DCMAKE_CXX_COMPILER=${{ matrix.compiler }} -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} -DTESTS=ON -DOPENSSL=ON -DCLANG_TIDY=ON -DCMAKE_EXPORT_COMPILE_COMMANDS=ON
         else
           cmake $GITHUB_WORKSPACE -DCMAKE_BUILD_TYPE=${{ matrix.build_type }} -DTESTS=ON
         fi
@@ -57,6 +57,11 @@ jobs:
       shell: bash
       run: cmake --build . --config ${{ matrix.build_type }}
 
+    - name: Clang-Tidy Header
+      if: matrix.os == 'ubuntu-latest'
+      shell: bash
+      run: clang-tidy merklecpp.h -p build/${{ matrix.build_type }} --warnings-as-errors='*'
+
     - name: Test
       working-directory: ${{github.workspace}}/build/${{ matrix.build_type }}
       shell: bash

CMakeLists.txt

@@ -13,6 +13,17 @@ option(TESTS "enable testing" OFF)
 option(EVERCRYPT "enable comparison with EverCrypt Merkle trees" OFF)
 option(OPENSSL "enable OpenSSL" OFF)
 option(TRACE "enable debug traces" OFF)
+option(CLANG_TIDY "enable clang-tidy checks during build" OFF)
+
+if(CLANG_TIDY)
+  find_program(CLANG_TIDY_PROGRAM clang-tidy)
+  if(CLANG_TIDY_PROGRAM)
+    set(CMAKE_CXX_CLANG_TIDY ${CLANG_TIDY_PROGRAM})
+    set(CMAKE_C_CLANG_TIDY ${CLANG_TIDY_PROGRAM})
+  else()
+    message(FATAL_ERROR "clang-tidy not found")
+  endif()
+endif()
 
 add_library(merklecpp INTERFACE)
 target_include_directories(merklecpp INTERFACE .)