simplify suppression handling by creating a custom local file

option(ENABLE_TESTING "Enable testing" OFF)

if(ENABLE_TESTING)

  find_program(VALGRIND_BINARY NAMES valgrind)

  set(VALGRIND_DEFAULT_OPTIONS "--leak-check=full --show-leak-kinds=all --track-origins=yes")

  # generate custom suppression file

  file(WRITE ${CMAKE_CURRENT_BINARY_DIR}/lammps.supp "\n")

  file(GLOB VALGRIND_SUPPRESSION_FILES ${LAMMPS_TOOLS_DIR}/valgrind/[^.]*.supp)

  foreach(SUPP ${VALLGRIND_SUPPRESSION_FILES})

    set(VALGRIND_DEFAULT_OPTIONS "${VALGRIND_DEFAULT_OPTIONS} --suppressions=${SUPP}")

  foreach(SUPP ${VALGRIND_SUPPRESSION_FILES})

    file(READ ${SUPP} SUPPRESSIONS)

    file(APPEND ${CMAKE_CURRENT_BINARY_DIR}/lammps.supp "${SUPPRESSIONS}")

  endforeach()

  set(VALGRIND_DEFAULT_OPTIONS "--leak-check=full --show-leak-kinds=all --track-origins=yes --suppressions=${CMAKE_BINARY_DIR}/lammps.supp")

  set(MEMORYCHECK_COMMAND "${VALGRIND_BINARY}" CACHE FILEPATH "Memory Check Command")

  set(MEMORYCHECK_COMMAND_OPTIONS "${VALGRIND_DEFAULT_OPTIONS}" CACHE STRING "Memory Check Command Options")

     - exclude subset of tests matching the regular expression <regex>

   * - -N

     - dry-run: display list of tests without running them

   * - -T memcheck

     - run tests with valgrind memory checker (if available)

In its full implementation, the unit test framework will consist of multiple

kinds of tests implemented in different programming languages (C++, C, Python,