CMakeLists.txt

# Copyright libOpenCOR contributors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

cmake_minimum_required(VERSION 3.15)

project(libOpenCOR
        VERSION 0.0.0)

string(TOLOWER "${CMAKE_PROJECT_NAME}" CMAKE_PROJECT_NAME_LC)

# Enable C++20.

set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)

# Some common CMake policies, functions, and macros.

foreach(POLICY CMP0144)
    if(POLICY ${POLICY})
        cmake_policy(SET ${POLICY} NEW)
    endif()
endforeach()

list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake)

include(common)

# Check whether we are meant to build our JavaScript bindings.

if(EMSCRIPTEN)
    # Use a lower-case version of our project name.

    string(TOLOWER "${CMAKE_PROJECT_NAME}" CMAKE_PROJECT_NAME)

    # Build libOpenCOR's JavaScript bindings.

    add_subdirectory(src)
else()
    # On macOS, deploy on macOS 13 and later.
    # Note #1: for some reasons, this gets ignored by LLVM+Clang when we try to build it on GitHub Actions using
    #          macos-13 (Intel) (even when setting the MACOSX_DEPLOYMENT_TARGET environment variable), which is why we
    #          now always use macos-14 (ARM) (not to mention that it is faster!) and pass -DTARGET_ARCHITECTURE=Intel to
    #          CMake if we want to build for macOS Intel on GHA.
    # Note #2: the value of MACOS_DEPLOYMENT_TARGET must be in sync with that of CIBW_ENVIRONMENT_MACOS in
    #          .github/workflows/cd.yml.

    if(APPLE)
        set(MACOS_DEPLOYMENT_TARGET 13)

        if("${CMAKE_OSX_DEPLOYMENT_TARGET}" STREQUAL "")
            set(CMAKE_OSX_DEPLOYMENT_TARGET ${MACOS_DEPLOYMENT_TARGET})
        endif()
    endif()

    # Check the environment we are dealing with.

    include(environmentchecks)

    # Initialise/reset our available targets.

    set(TARGETS "install" CACHE INTERNAL "Available targets.")

    # [CMAKE_]BUILD_TYPE ==> LIBOPENCOR_BUILD_TYPE.

    if(NOT IS_MULTI_CONFIG)
        set(LIBOPENCOR_BUILD_TYPE_DOCSTRING "Choose the type of build, options are: None Debug Release RelWithDebInfo MinSizeRel ...")

        if(NOT "${BUILD_TYPE}" STREQUAL "")
            set(LIBOPENCOR_BUILD_TYPE "${BUILD_TYPE}" CACHE STRING "${LIBOPENCOR_BUILD_TYPE_DOCSTRING}" FORCE)
        elseif(NOT "${CMAKE_BUILD_TYPE}" STREQUAL "")
            set(LIBOPENCOR_BUILD_TYPE "${CMAKE_BUILD_TYPE}" CACHE STRING "${LIBOPENCOR_BUILD_TYPE_DOCSTRING}")
        else()
            set(LIBOPENCOR_BUILD_TYPE "Debug" CACHE STRING "${LIBOPENCOR_BUILD_TYPE_DOCSTRING}")
        endif()

        set(CMAKE_BUILD_TYPE "${LIBOPENCOR_BUILD_TYPE}" CACHE INTERNAL "Internalise CMAKE_BUILD_TYPE, manipulate via LIBOPENCOR_BUILD_TYPE." FORCE)
    endif()

    unset(BUILD_TYPE CACHE)

    # CODE_ANALYSIS ==> LIBOPENCOR_CODE_ANALYSIS.

    if(CODE_ANALYSIS_AVAILABLE)
        set(LIBOPENCOR_CODE_ANALYSIS_DOCSTRING "Enable code analysis.")
        set(LIBOPENCOR_CODE_ANALYSIS OFF CACHE BOOL "${LIBOPENCOR_CODE_ANALYSIS_DOCSTRING}")
    endif()

    if(NOT "${CODE_ANALYSIS}" STREQUAL "" AND CODE_ANALYSIS_AVAILABLE)
        set(LIBOPENCOR_CODE_ANALYSIS ${CODE_ANALYSIS} CACHE BOOL "${LIBOPENCOR_CODE_ANALYSIS_DOCSTRING}" FORCE)
    elseif(CODE_ANALYSIS)
        message(SEND_ERROR "${CODE_ANALYSIS_ERROR_MESSAGE}")

        set(SENT_ERRORS TRUE)
    endif()

    unset(CODE_ANALYSIS CACHE)

    # CODE_COVERAGE ==> LIBOPENCOR_CODE_COVERAGE.

    if(CODE_COVERAGE_AVAILABLE)
        set(LIBOPENCOR_CODE_COVERAGE_DOCSTRING "Enable code coverage testing.")
        set(LIBOPENCOR_CODE_COVERAGE OFF CACHE BOOL "${LIBOPENCOR_CODE_COVERAGE_DOCSTRING}")
    endif()

    if(NOT "${CODE_COVERAGE}" STREQUAL "" AND CODE_COVERAGE_AVAILABLE)
        set(LIBOPENCOR_CODE_COVERAGE ${CODE_COVERAGE} CACHE BOOL "${LIBOPENCOR_CODE_COVERAGE_DOCSTRING}" FORCE)
    elseif(CODE_COVERAGE)
        message(SEND_ERROR "${CODE_COVERAGE_ERROR_MESSAGE}")

        set(SENT_ERRORS TRUE)
    endif()

    unset(CODE_COVERAGE CACHE)

    # COMPILER_CACHING ==> LIBOPENCOR_COMPILER_CACHING.

    if(COMPILER_CACHING_AVAILABLE)
        set(LIBOPENCOR_COMPILER_CACHING_DOCSTRING "Enable compiler caching.")
        set(LIBOPENCOR_COMPILER_CACHING ON CACHE BOOL "${LIBOPENCOR_COMPILER_CACHING_DOCSTRING}")
    endif()

    if(NOT "${COMPILER_CACHING}" STREQUAL "" AND COMPILER_CACHING_AVAILABLE)
        set(LIBOPENCOR_COMPILER_CACHING ${COMPILER_CACHING} CACHE BOOL "${LIBOPENCOR_COMPILER_CACHING_DOCSTRING}" FORCE)
    elseif(COMPILER_CACHING)
        message(SEND_ERROR "${COMPILER_CACHING_ERROR_MESSAGE}")

        set(SENT_ERRORS TRUE)
    endif()

    unset(COMPILER_CACHING CACHE)

    # DOCUMENTATION ==> LIBOPENCOR_DOCUMENTATION.

    if(DOCUMENTATION_AVAILABLE)
        set(LIBOPENCOR_DOCUMENTATION_DOCSTRING "Generate the documentation.")
        set(LIBOPENCOR_DOCUMENTATION ON CACHE BOOL "${LIBOPENCOR_DOCUMENTATION_DOCSTRING}")
    endif()

    if(NOT "${DOCUMENTATION}" STREQUAL "" AND DOCUMENTATION_AVAILABLE)
        set(LIBOPENCOR_DOCUMENTATION ${DOCUMENTATION} CACHE BOOL "${LIBOPENCOR_DOCUMENTATION_DOCSTRING}" FORCE)
    elseif(DOCUMENTATION)
        message(SEND_ERROR "${DOCUMENTATION_AVAILABLE_ERROR_MESSAGE}")

        set(SENT_ERRORS TRUE)
    endif()

    unset(DOCUMENTATION CACHE)

    # [CMAKE_]INSTALL_PREFIX ==> LIBOPENCOR_INSTALL_PREFIX.

    set(LIBOPENCOR_INSTALL_PREFIX_DOCSTRING "Install path prefix, prepended onto install directories.")

    if(NOT "${INSTALL_PREFIX}" STREQUAL "")
        set(LIBOPENCOR_INSTALL_PREFIX "${INSTALL_PREFIX}" CACHE PATH "${LIBOPENCOR_INSTALL_PREFIX_DOCSTRING}" FORCE)
    elseif(NOT "${CMAKE_INSTALL_PREFIX}" STREQUAL "")
        set(LIBOPENCOR_INSTALL_PREFIX "${CMAKE_INSTALL_PREFIX}" CACHE STRING "${LIBOPENCOR_INSTALL_PREFIX_DOCSTRING}")
    else()
        set(LIBOPENCOR_INSTALL_PREFIX "${CMAKE_INSTALL_PREFIX}" CACHE PATH "${LIBOPENCOR_INSTALL_PREFIX_DOCSTRING}")
    endif()

    file(TO_CMAKE_PATH "${LIBOPENCOR_INSTALL_PREFIX}" CMAKE_INSTALL_PREFIX_PATH)

    set(CMAKE_INSTALL_PREFIX "${CMAKE_INSTALL_PREFIX_PATH}" CACHE INTERNAL "Internalise CMAKE_INSTALL_PREFIX, manipulate via LIBOPENCOR_INSTALL_PREFIX.")

    unset(INSTALL_PREFIX CACHE)

    # JAVASCRIPT_BINDINGS ==> LIBOPENCOR_JAVASCRIPT_BINDINGS.

    if(JAVASCRIPT_BINDINGS_AVAILABLE)
        set(LIBOPENCOR_JAVASCRIPT_BINDINGS_DOCSTRING "Build JAVASCRIPT bindings.")
        set(LIBOPENCOR_JAVASCRIPT_BINDINGS OFF CACHE BOOL "${LIBOPENCOR_JAVASCRIPT_BINDINGS_DOCSTRING}")
    endif()

    if(NOT "${JAVASCRIPT_BINDINGS}" STREQUAL "" AND JAVASCRIPT_BINDINGS_AVAILABLE)
        set(LIBOPENCOR_JAVASCRIPT_BINDINGS ${JAVASCRIPT_BINDINGS} CACHE BOOL "${LIBOPENCOR_JAVASCRIPT_BINDINGS_DOCSTRING}" FORCE)
    elseif(JAVASCRIPT_BINDINGS)
        message(SEND_ERROR "${JAVASCRIPT_BINDINGS_ERROR_MESSAGE}")

        set(SENT_ERRORS TRUE)
    endif()

    unset(JAVASCRIPT_BINDINGS CACHE)

    # JAVASCRIPT_UNIT_TESTING ==> LIBOPENCOR_JAVASCRIPT_UNIT_TESTING.

    if(JAVASCRIPT_BINDINGS_AVAILABLE)
        if(JAVASCRIPT_UNIT_TESTING_AVAILABLE)
            set(LIBOPENCOR_JAVASCRIPT_UNIT_TESTING_DOCSTRING "Enable JAVASCRIPT unit testing.")
            set(LIBOPENCOR_JAVASCRIPT_UNIT_TESTING ${LIBOPENCOR_JAVASCRIPT_BINDINGS} CACHE BOOL "${LIBOPENCOR_JAVASCRIPT_UNIT_TESTING_DOCSTRING}")
        endif()

        if(NOT "${JAVASCRIPT_UNIT_TESTING}" STREQUAL "" AND JAVASCRIPT_UNIT_TESTING_AVAILABLE)
            set(LIBOPENCOR_JAVASCRIPT_UNIT_TESTING ${JAVASCRIPT_UNIT_TESTING} CACHE BOOL "${LIBOPENCOR_JAVASCRIPT_UNIT_TESTING_DOCSTRING}" FORCE)
        elseif(JAVASCRIPT_UNIT_TESTING)
            message(SEND_ERROR "${JAVASCRIPT_UNIT_TESTING_ERROR_MESSAGE}")

            set(SENT_ERRORS TRUE)
        endif()

        unset(JAVASCRIPT_UNIT_TESTING CACHE)
    endif()

    # MEMORY_CHECKS ==> LIBOPENCOR_MEMORY_CHECKS.

    if(MEMORY_CHECKS_AVAILABLE)
        set(LIBOPENCOR_MEMORY_CHECKS_DOCSTRING "Enable memory checks.")
        set(LIBOPENCOR_MEMORY_CHECKS OFF CACHE BOOL "${LIBOPENCOR_MEMORY_CHECKS_DOCSTRING}")
    endif()

    if(NOT "${MEMORY_CHECKS}" STREQUAL "" AND MEMORY_CHECKS_AVAILABLE)
        set(LIBOPENCOR_MEMORY_CHECKS ${MEMORY_CHECKS} CACHE BOOL "${LIBOPENCOR_MEMORY_CHECKS_DOCSTRING}" FORCE)
    elseif(MEMORY_CHECKS)
        message(SEND_ERROR "${MEMORY_CHECKS_ERROR_MESSAGE}")

        set(SENT_ERRORS TRUE)
    endif()

    unset(MEMORY_CHECKS CACHE)

    # PREBUILT_LIBCELLML ==> LIBOPENCOR_PREBUILT_LIBCELLML.

    set(LIBOPENCOR_PREBUILT_LIBCELLML_DOCSTRING "Use the prebuilt version of libCellML.")
    set(LIBOPENCOR_PREBUILT_LIBCELLML ON CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBCELLML_DOCSTRING}")

    if(NOT "${PREBUILT_LIBCELLML}" STREQUAL "")
        set(LIBOPENCOR_PREBUILT_LIBCELLML ${PREBUILT_LIBCELLML} CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBCELLML_DOCSTRING}" FORCE)
    endif()

    unset(PREBUILT_LIBCELLML CACHE)

    # PREBUILT_LIBCOMBINE ==> LIBOPENCOR_PREBUILT_LIBCOMBINE.

    set(LIBOPENCOR_PREBUILT_LIBCOMBINE_DOCSTRING "Use the prebuilt version of libCOMBINE.")
    set(LIBOPENCOR_PREBUILT_LIBCOMBINE ON CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBCOMBINE_DOCSTRING}")

    if(NOT "${PREBUILT_LIBCOMBINE}" STREQUAL "")
        set(LIBOPENCOR_PREBUILT_LIBCOMBINE ${PREBUILT_LIBCOMBINE} CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBCOMBINE_DOCSTRING}" FORCE)
    endif()

    unset(PREBUILT_LIBCOMBINE CACHE)

    # PREBUILT_LIBCURL ==> LIBOPENCOR_PREBUILT_LIBCURL.

    set(LIBOPENCOR_PREBUILT_LIBCURL_DOCSTRING "Use the prebuilt version of libcurl.")
    set(LIBOPENCOR_PREBUILT_LIBCURL ON CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBCURL_DOCSTRING}")

    if(NOT "${PREBUILT_LIBCURL}" STREQUAL "")
        set(LIBOPENCOR_PREBUILT_LIBCURL ${PREBUILT_LIBCURL} CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBCURL_DOCSTRING}" FORCE)
    endif()

    unset(PREBUILT_LIBCURL CACHE)

    # PREBUILT_LIBNUML ==> LIBOPENCOR_PREBUILT_LIBNUML.

    set(LIBOPENCOR_PREBUILT_LIBNUML_DOCSTRING "Use the prebuilt version of libNuML.")
    set(LIBOPENCOR_PREBUILT_LIBNUML ON CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBNUML_DOCSTRING}")

    if(NOT "${PREBUILT_LIBNUML}" STREQUAL "")
        set(LIBOPENCOR_PREBUILT_LIBNUML ${PREBUILT_LIBNUML} CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBNUML_DOCSTRING}" FORCE)
    endif()

    unset(PREBUILT_LIBNUML CACHE)

    # PREBUILT_LIBSBML ==> LIBOPENCOR_PREBUILT_LIBSBML.

    set(LIBOPENCOR_PREBUILT_LIBSBML_DOCSTRING "Use the prebuilt version of libSBML.")
    set(LIBOPENCOR_PREBUILT_LIBSBML ON CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBSBML_DOCSTRING}")

    if(NOT "${PREBUILT_LIBSBML}" STREQUAL "")
        set(LIBOPENCOR_PREBUILT_LIBSBML ${PREBUILT_LIBSBML} CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBSBML_DOCSTRING}" FORCE)
    endif()

    unset(PREBUILT_LIBSBML CACHE)

    # PREBUILT_LIBSEDML ==> LIBOPENCOR_PREBUILT_LIBSEDML.

    set(LIBOPENCOR_PREBUILT_LIBSEDML_DOCSTRING "Use the prebuilt version of libSEDML.")
    set(LIBOPENCOR_PREBUILT_LIBSEDML ON CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBSEDML_DOCSTRING}")

    if(NOT "${PREBUILT_LIBSEDML}" STREQUAL "")
        set(LIBOPENCOR_PREBUILT_LIBSEDML ${PREBUILT_LIBSEDML} CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBSEDML_DOCSTRING}" FORCE)
    endif()

    unset(PREBUILT_LIBSEDML CACHE)

    # PREBUILT_LIBSSH2 ==> LIBOPENCOR_PREBUILT_LIBSSH2.

    set(LIBOPENCOR_PREBUILT_LIBSSH2_DOCSTRING "Use the prebuilt version of libssh2.")
    set(LIBOPENCOR_PREBUILT_LIBSSH2 ON CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBSSH2_DOCSTRING}")

    if(NOT "${PREBUILT_LIBSSH2}" STREQUAL "")
        set(LIBOPENCOR_PREBUILT_LIBSSH2 ${PREBUILT_LIBSSH2} CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBSSH2_DOCSTRING}" FORCE)
    endif()

    unset(PREBUILT_LIBSSH2 CACHE)

    # PREBUILT_LIBXML2 ==> LIBOPENCOR_PREBUILT_LIBXML2.

    set(LIBOPENCOR_PREBUILT_LIBXML2_DOCSTRING "Use the prebuilt version of libxml2.")
    set(LIBOPENCOR_PREBUILT_LIBXML2 ON CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBXML2_DOCSTRING}")

    if(NOT "${PREBUILT_LIBXML2}" STREQUAL "")
        set(LIBOPENCOR_PREBUILT_LIBXML2 ${PREBUILT_LIBXML2} CACHE BOOL "${LIBOPENCOR_PREBUILT_LIBXML2_DOCSTRING}" FORCE)
    endif()

    unset(PREBUILT_LIBXML2 CACHE)

    # PREBUILT_LLVMCLANG ==> LIBOPENCOR_PREBUILT_LLVMCLANG.

    set(LIBOPENCOR_PREBUILT_LLVMCLANG_DOCSTRING "Use the prebuilt version of LLVM+Clang.")
    set(LIBOPENCOR_PREBUILT_LLVMCLANG ON CACHE BOOL "${LIBOPENCOR_PREBUILT_LLVMCLANG_DOCSTRING}")

    if(NOT "${PREBUILT_LLVMCLANG}" STREQUAL "")
        set(LIBOPENCOR_PREBUILT_LLVMCLANG ${PREBUILT_LLVMCLANG} CACHE BOOL "${LIBOPENCOR_PREBUILT_LLVMCLANG_DOCSTRING}" FORCE)
    endif()

    unset(PREBUILT_LLVMCLANG CACHE)

    # PREBUILT_OPENSSL ==> LIBOPENCOR_PREBUILT_OPENSSL.

    set(LIBOPENCOR_PREBUILT_OPENSSL_DOCSTRING "Use the prebuilt version of OpenSSL.")
    set(LIBOPENCOR_PREBUILT_OPENSSL ON CACHE BOOL "${LIBOPENCOR_PREBUILT_OPENSSL_DOCSTRING}")

    if(NOT "${PREBUILT_OPENSSL}" STREQUAL "")
        set(LIBOPENCOR_PREBUILT_OPENSSL ${PREBUILT_OPENSSL} CACHE BOOL "${LIBOPENCOR_PREBUILT_OPENSSL_DOCSTRING}" FORCE)
    endif()

    unset(PREBUILT_OPENSSL CACHE)

    # PREBUILT_SUNDIALS ==> LIBOPENCOR_PREBUILT_SUNDIALS.

    set(LIBOPENCOR_PREBUILT_SUNDIALS_DOCSTRING "Use the prebuilt version of SUNDIALS.")
    set(LIBOPENCOR_PREBUILT_SUNDIALS ON CACHE BOOL "${LIBOPENCOR_PREBUILT_SUNDIALS_DOCSTRING}")

    if(NOT "${PREBUILT_SUNDIALS}" STREQUAL "")
        set(LIBOPENCOR_PREBUILT_SUNDIALS ${PREBUILT_SUNDIALS} CACHE BOOL "${LIBOPENCOR_PREBUILT_SUNDIALS_DOCSTRING}" FORCE)
    endif()

    unset(PREBUILT_SUNDIALS CACHE)

    # PREBUILT_ZIPPER ==> LIBOPENCOR_PREBUILT_ZIPPER.

    set(LIBOPENCOR_PREBUILT_ZIPPER_DOCSTRING "Use the prebuilt version of zipper.")
    set(LIBOPENCOR_PREBUILT_ZIPPER ON CACHE BOOL "${LIBOPENCOR_PREBUILT_ZIPPER_DOCSTRING}")

    if(NOT "${PREBUILT_ZIPPER}" STREQUAL "")
        set(LIBOPENCOR_PREBUILT_ZIPPER ${PREBUILT_ZIPPER} CACHE BOOL "${LIBOPENCOR_PREBUILT_ZIPPER_DOCSTRING}" FORCE)
    endif()

    unset(PREBUILT_ZIPPER CACHE)

    # PREBUILT_ZLIB ==> LIBOPENCOR_PREBUILT_ZLIB.

    set(LIBOPENCOR_PREBUILT_ZLIB_DOCSTRING "Use the prebuilt version of zlib.")
    set(LIBOPENCOR_PREBUILT_ZLIB ON CACHE BOOL "${LIBOPENCOR_PREBUILT_ZLIB_DOCSTRING}")

    if(NOT "${PREBUILT_ZLIB}" STREQUAL "")
        set(LIBOPENCOR_PREBUILT_ZLIB ${PREBUILT_ZLIB} CACHE BOOL "${LIBOPENCOR_PREBUILT_ZLIB_DOCSTRING}" FORCE)
    endif()

    unset(PREBUILT_ZLIB CACHE)

    # PYTHON_BINDINGS ==> LIBOPENCOR_PYTHON_BINDINGS.

    if(PYTHON_BINDINGS_AVAILABLE)
        set(LIBOPENCOR_PYTHON_BINDINGS_DOCSTRING "Build Python bindings.")
        set(LIBOPENCOR_PYTHON_BINDINGS OFF CACHE BOOL "${LIBOPENCOR_PYTHON_BINDINGS_DOCSTRING}")
    endif()

    if(NOT "${PYTHON_BINDINGS}" STREQUAL "" AND PYTHON_BINDINGS_AVAILABLE)
        set(LIBOPENCOR_PYTHON_BINDINGS ${PYTHON_BINDINGS} CACHE BOOL "${LIBOPENCOR_PYTHON_BINDINGS_DOCSTRING}" FORCE)
    elseif(PYTHON_BINDINGS)
        message(SEND_ERROR "${PYTHON_BINDINGS_ERROR_MESSAGE}")

        set(SENT_ERRORS TRUE)
    endif()

    unset(PYTHON_BINDINGS CACHE)

    # PYTHON_UNIT_TESTING ==> LIBOPENCOR_PYTHON_UNIT_TESTING.

    if(PYTHON_BINDINGS_AVAILABLE)
        if(PYTHON_UNIT_TESTING_AVAILABLE)
            set(LIBOPENCOR_PYTHON_UNIT_TESTING_DOCSTRING "Enable Python unit testing.")
            set(LIBOPENCOR_PYTHON_UNIT_TESTING ${LIBOPENCOR_PYTHON_BINDINGS} CACHE BOOL "${LIBOPENCOR_PYTHON_UNIT_TESTING_DOCSTRING}")
        endif()

        if(NOT "${PYTHON_UNIT_TESTING}" STREQUAL "" AND PYTHON_UNIT_TESTING_AVAILABLE)
            set(LIBOPENCOR_PYTHON_UNIT_TESTING ${PYTHON_UNIT_TESTING} CACHE BOOL "${LIBOPENCOR_PYTHON_UNIT_TESTING_DOCSTRING}" FORCE)
        elseif(PYTHON_UNIT_TESTING)
            message(SEND_ERROR "${PYTHON_UNIT_TESTING_ERROR_MESSAGE}")

            set(SENT_ERRORS TRUE)
        endif()

        unset(PYTHON_UNIT_TESTING CACHE)
    endif()

    # [BUILD_]SHARED_LIBS ==> LIBOPENCOR_SHARED_LIBS.

    set(LIBOPENCOR_SHARED_LIBS_DOCSTRING "Build shared libraries.")

    if(NOT "${SHARED_LIBS}" STREQUAL "")
        set(LIBOPENCOR_SHARED_LIBS ${SHARED_LIBS} CACHE BOOL "${LIBOPENCOR_SHARED_LIBS_DOCSTRING}" FORCE)
    else()
        set(LIBOPENCOR_SHARED_LIBS ON CACHE BOOL "${LIBOPENCOR_SHARED_LIBS_DOCSTRING}")
    endif()

    set(BUILD_SHARED_LIBS ${LIBOPENCOR_SHARED_LIBS} CACHE INTERNAL "Internalise BUILD_SHARED_LIBS, manipulate via LIBOPENCOR_SHARED_LIBS.")

    unset(SHARED_LIBS CACHE)

    # TARGET_ARCHITECTURE ==> LIBOPENCOR_TARGET_ARCHITECTURE.
    # Note: this is only relevant on macOS since on Windows the target architecture is always going to be the same as
    #       that of the version of MSVC we are using (i.e. x64 or arm64) while on Linux we have no choice but to target
    #       the same architecture as that of the system.

    if(APPLE)
        set(LIBOPENCOR_TARGET_ARCHITECTURE_DOCSTRING "Specify the target architecture (Intel or ARM).")
        set(LIBOPENCOR_TARGET_ARCHITECTURE ${DEFAULT_TARGET_ARCHITECTURE} CACHE STRING "${LIBOPENCOR_TARGET_ARCHITECTURE_DOCSTRING}")

        if(NOT "${TARGET_ARCHITECTURE}" STREQUAL "")
            set(LIBOPENCOR_TARGET_ARCHITECTURE ${TARGET_ARCHITECTURE} CACHE STRING "${LIBOPENCOR_TARGET_ARCHITECTURE_DOCSTRING}" FORCE)
        endif()

        unset(TARGET_ARCHITECTURE CACHE)
    endif()

    # UNIT_TESTING ==> LIBOPENCOR_UNIT_TESTING.

    set(LIBOPENCOR_UNIT_TESTING_DOCSTRING "Enable unit testing.")
    set(LIBOPENCOR_UNIT_TESTING ON CACHE BOOL "${LIBOPENCOR_UNIT_TESTING_DOCSTRING}")

    if(NOT "${UNIT_TESTING}" STREQUAL "")
        set(LIBOPENCOR_UNIT_TESTING ${UNIT_TESTING} CACHE BOOL "${LIBOPENCOR_UNIT_TESTING_DOCSTRING}" FORCE)
    endif()

    unset(UNIT_TESTING CACHE)

    # WARNINGS_AS_ERRORS ==> LIBOPENCOR_WARNINGS_AS_ERRORS.

    set(LIBOPENCOR_WARNINGS_AS_ERRORS_DOCSTRING "Treat warnings as errors.")
    set(LIBOPENCOR_WARNINGS_AS_ERRORS ON CACHE BOOL "${LIBOPENCOR_WARNINGS_AS_ERRORS_DOCSTRING}")

    if(NOT "${WARNINGS_AS_ERRORS}" STREQUAL "")
        set(LIBOPENCOR_WARNINGS_AS_ERRORS ${WARNINGS_AS_ERRORS} CACHE BOOL "${LIBOPENCOR_WARNINGS_AS_ERRORS_DOCSTRING}" FORCE)
    endif()

    unset(WARNINGS_AS_ERRORS CACHE)

    # Make sure that the configuration is sound.

    if(LIBOPENCOR_CODE_COVERAGE)
        if(NOT LIBOPENCOR_SHARED_LIBS)
            message(SEND_ERROR "Configuration confusion: code coverage is requested which means that a static library cannot be requested.")

            set(SENT_ERRORS TRUE)
        endif()

        if(NOT LIBOPENCOR_UNIT_TESTING)
            message(SEND_ERROR "Configuration confusion: code coverage is requested which means that unit testing should also be requested.")

            set(SENT_ERRORS TRUE)
        endif()
    endif()

    if(LIBOPENCOR_MEMORY_CHECKS)
        if("${LIBOPENCOR_BUILD_TYPE}" STREQUAL "Release")
            message(SEND_ERROR "Configuration confusion: memory checks are requested which means that a release build cannot also be requested.")

            set(SENT_ERRORS TRUE)
        endif()

        if(NOT LIBOPENCOR_UNIT_TESTING)
            message(SEND_ERROR "Configuration confusion: memory checks are requested which means that unit testing should also be requested.")

            set(SENT_ERRORS TRUE)
        endif()
    endif()

    if(LIBOPENCOR_PYTHON_BINDINGS)
        if(LIBOPENCOR_SHARED_LIBS)
            message(SEND_ERROR "Configuration confusion: Python bindings are requested which means that a shared library cannot be requested.")

            set(SENT_ERRORS TRUE)
        endif()
    endif()

    if(LIBOPENCOR_PYTHON_UNIT_TESTING)
        if(NOT LIBOPENCOR_PYTHON_BINDINGS)
            message(SEND_ERROR "Configuration confusion: Python unit testing is requested which means that Python bindings should also be requested.")

            set(SENT_ERRORS TRUE)
        endif()
    endif()

    if(APPLE)
        if(    NOT "${LIBOPENCOR_TARGET_ARCHITECTURE}" STREQUAL "Intel"
           AND NOT "${LIBOPENCOR_TARGET_ARCHITECTURE}" STREQUAL "ARM")
            message(SEND_ERROR "Configuration error: unsupported target architecture (${LIBOPENCOR_TARGET_ARCHITECTURE}). Supported target architectures are Intel and ARM.")

            set(SENT_ERRORS TRUE)
        endif()
    endif()

    if(SENT_ERRORS)
        return()
    endif()

    # Determine whether we are building in release mode.
    # Note: this only makes sense if we are not in a multi-configuration mode, i.e. IS_MULTI_CONFIG is equal to FALSE, which
    #       is likely to be the case when building a third-party library.

    if(NOT "${LIBOPENCOR_BUILD_TYPE}" STREQUAL "Debug")
        set(RELEASE_MODE TRUE)
    endif()

    # Determine whether we are building for an Intel processor.

    if("${LIBOPENCOR_TARGET_ARCHITECTURE}" STREQUAL "Intel")
        set(INTEL_MODE TRUE)

        if(APPLE)
            set(CMAKE_OSX_ARCHITECTURES x86_64)
        endif()
    elseif(APPLE)
        set(CMAKE_OSX_ARCHITECTURES arm64)
    endif()

    # Build libOpenCOR.

    add_subdirectory(src)
endif()

# Carry on if we are not building our JavaScript bindings and we don't only want to build some third-party libraries.

if(NOT EMSCRIPTEN AND NOT ONLY_BUILD_THIRD_PARTY_LIBRARIES)
    # Enable unit testing.

    if(LIBOPENCOR_UNIT_TESTING)
        enable_testing()

        set(BUILD_GMOCK OFF CACHE BOOL "" FORCE)
        set(INSTALL_GTEST OFF CACHE BOOL "" FORCE)

        add_subdirectory(extern/googletest)

        mark_as_advanced(BUILD_GMOCK
                         GTEST_HAS_ABSL
                         INSTALL_GTEST)
    endif()

    # Run our tests.

    add_subdirectory(tests)

    # Generate our documentation.

    add_subdirectory(doc)

    # Check our code formatting and format our code.

    add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/cmake/formatting)

    # Package libOpenCOR.

    add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/cmake/packaging)

    # Summary of our configuration.

    message(STATUS "Configuration summary:")

    if(NOT "${LIBOPENCOR_BUILD_TYPE}" STREQUAL "")
        message(STATUS " - LIBOPENCOR_BUILD_TYPE:              ${LIBOPENCOR_BUILD_TYPE}")
    endif()

    if(NOT "${LIBOPENCOR_CODE_ANALYSIS}" STREQUAL "")
        message(STATUS " - LIBOPENCOR_CODE_ANALYSIS:           ${LIBOPENCOR_CODE_ANALYSIS}")
    endif()

    if(NOT "${LIBOPENCOR_CODE_COVERAGE}" STREQUAL "")
        message(STATUS " - LIBOPENCOR_CODE_COVERAGE:           ${LIBOPENCOR_CODE_COVERAGE}")
    endif()

    if(NOT "${LIBOPENCOR_COMPILER_CACHING}" STREQUAL "")
        message(STATUS " - LIBOPENCOR_COMPILER_CACHING:        ${LIBOPENCOR_COMPILER_CACHING}")
    endif()

    if(NOT "${LIBOPENCOR_DOCUMENTATION}" STREQUAL "")
        message(STATUS " - LIBOPENCOR_DOCUMENTATION:           ${LIBOPENCOR_DOCUMENTATION}")
    endif()

    message(STATUS " - LIBOPENCOR_INSTALL_PREFIX:          ${LIBOPENCOR_INSTALL_PREFIX}")

    if(NOT "${LIBOPENCOR_JAVASCRIPT_BINDINGS}" STREQUAL "")
        message(STATUS " - LIBOPENCOR_JAVASCRIPT_BINDINGS:     ${LIBOPENCOR_JAVASCRIPT_BINDINGS}")
    endif()

    if(NOT "${LIBOPENCOR_JAVASCRIPT_UNIT_TESTING}" STREQUAL "")
        message(STATUS " - LIBOPENCOR_JAVASCRIPT_UNIT_TESTING: ${LIBOPENCOR_JAVASCRIPT_UNIT_TESTING}")
    endif()

    if(NOT "${LIBOPENCOR_MEMORY_CHECKS}" STREQUAL "")
        message(STATUS " - LIBOPENCOR_MEMORY_CHECKS:           ${LIBOPENCOR_MEMORY_CHECKS}")
    endif()

    message(STATUS " - LIBOPENCOR_PREBUILT_LIBCELLML:      ${LIBOPENCOR_PREBUILT_LIBCELLML}")
    message(STATUS " - LIBOPENCOR_PREBUILT_LIBCOMBINE:     ${LIBOPENCOR_PREBUILT_LIBCOMBINE}")
    message(STATUS " - LIBOPENCOR_PREBUILT_LIBCURL:        ${LIBOPENCOR_PREBUILT_LIBCURL}")
    message(STATUS " - LIBOPENCOR_PREBUILT_LIBNUML:        ${LIBOPENCOR_PREBUILT_LIBNUML}")
    message(STATUS " - LIBOPENCOR_PREBUILT_LIBSBML:        ${LIBOPENCOR_PREBUILT_LIBSBML}")
    message(STATUS " - LIBOPENCOR_PREBUILT_LIBSEDML:       ${LIBOPENCOR_PREBUILT_LIBSEDML}")
    message(STATUS " - LIBOPENCOR_PREBUILT_LIBSSH2:        ${LIBOPENCOR_PREBUILT_LIBSSH2}")
    message(STATUS " - LIBOPENCOR_PREBUILT_LIBXML2:        ${LIBOPENCOR_PREBUILT_LIBXML2}")
    message(STATUS " - LIBOPENCOR_PREBUILT_LLVMCLANG:      ${LIBOPENCOR_PREBUILT_LLVMCLANG}")
    message(STATUS " - LIBOPENCOR_PREBUILT_OPENSSL:        ${LIBOPENCOR_PREBUILT_OPENSSL}")
    message(STATUS " - LIBOPENCOR_PREBUILT_SUNDIALS:       ${LIBOPENCOR_PREBUILT_SUNDIALS}")
    message(STATUS " - LIBOPENCOR_PREBUILT_ZIPPER:         ${LIBOPENCOR_PREBUILT_ZIPPER}")
    message(STATUS " - LIBOPENCOR_PREBUILT_ZLIB:           ${LIBOPENCOR_PREBUILT_ZLIB}")

    if(NOT "${LIBOPENCOR_PYTHON_BINDINGS}" STREQUAL "")
        message(STATUS " - LIBOPENCOR_PYTHON_BINDINGS:         ${LIBOPENCOR_PYTHON_BINDINGS}")
    endif()

    if(NOT "${LIBOPENCOR_PYTHON_UNIT_TESTING}" STREQUAL "")
        message(STATUS " - LIBOPENCOR_PYTHON_UNIT_TESTING:     ${LIBOPENCOR_PYTHON_UNIT_TESTING}")
    endif()

    message(STATUS " - LIBOPENCOR_SHARED_LIBS:             ${LIBOPENCOR_SHARED_LIBS}")
    message(STATUS " - LIBOPENCOR_TARGET_ARCHITECTURE:     ${LIBOPENCOR_TARGET_ARCHITECTURE}")
    message(STATUS " - LIBOPENCOR_UNIT_TESTING:            ${LIBOPENCOR_UNIT_TESTING}")
    message(STATUS " - LIBOPENCOR_WARNINGS_AS_ERRORS:      ${LIBOPENCOR_WARNINGS_AS_ERRORS}")

    # Summary of our available targets.

    message(STATUS "Useful targets:")

    foreach(TARGET ${TARGETS})
        message(STATUS " - ${TARGET}")
    endforeach()
endif()