Merge pull request #2157 from akohlmey/use-clang-format-demo

          COMMENT "Fix whitespace errors")

        add_custom_target(

          fix-permissions

          ${Python3_EXECUTABLE} ${LAMMPS_TOOLS_DIR}/coding_standard/permission.py -f .

          ${Python3_EXECUTABLE} ${LAMMPS_TOOLS_DIR}/coding_standard/permissions.py -f .

          WORKING_DIRECTORY  ${LAMMPS_DIR}

          COMMENT "Fix permission errors")

    endif()

# Find clang-format

find_program(ClangFormat_EXECUTABLE NAMES clang-format

                                          clang-format-10.0

                                          clang-format-9.0

                                          clang-format-8.0

                                          clang-format-7.0

                                          clang-format-6.0

                                     DOC "clang-format executable")

mark_as_advanced(ClangFormat_EXECUTABLE)

if(ClangFormat_EXECUTABLE)

  # find version

  execute_process(COMMAND ${ClangFormat_EXECUTABLE} --version

                  OUTPUT_VARIABLE clang_format_version

                  ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)

  if(clang_format_version MATCHES "^clang-format version .*")

    # Arch Linux

    # clang-format version 10.0.0

    # Ubuntu 18.04 LTS Output

    # clang-format version 6.0.0-1ubuntu2 (tags/RELEASE_600/final)

    string(REGEX REPLACE "clang-format version ([0-9.]+).*"

                         "\\1"

                         ClangFormat_VERSION

                         "${clang_format_version}")

  elseif(clang_format_version MATCHES ".*LLVM version .*")

    # CentOS 7 Output

    # LLVM (http://llvm.org/):

    #   LLVM version 3.4.2

    #   Optimized build.

    #   Built Nov  1 2018 (15:06:24).

    #   Default target: x86_64-redhat-linux-gnu

    #   Host CPU: x86-64

    string(REGEX REPLACE ".*LLVM version ([0-9.]+).*"

                         "\\1"

                         ClangFormat_VERSION

                         "${clang_format_version}")

  else()

    set(ClangFormat_VERSION "0.0")

  endif()

endif()

include(FindPackageHandleStandardArgs)

find_package_handle_standard_args(ClangFormat REQUIRED_VARS ClangFormat_EXECUTABLE VERSION_VAR ClangFormat_VERSION)