CMakeLists.txt

# ######################################################################## #
# File:     /CMakeLists.txt
#
# Purpose:  Top-level CMake lists file for recls
#
# Created:  9th October 2019
# Updated:  2nd January 2024
#
# ######################################################################## #


# ##########################################################
# CMake

cmake_minimum_required(VERSION 3.20 FATAL_ERROR)

# require out-of-source builds
file(TO_CMAKE_PATH "${CMAKE_CURRENT_BINARY_DIR}/CMakeLists.txt" LOC_PATH)
if(EXISTS "${LOC_PATH}")

    message(FATAL_ERROR "You cannot build in a source directory (or any directory with a CMakeLists.txt file). Please make a build subdirectory. Feel free to remove CMakeCache.txt and CMakeFiles.")
endif()

# directory for CMake specific extensions and source files.
set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake" ${CMAKE_MODULE_PATH})


# ##########################################################
# project

project(recls
    DESCRIPTION "recls is a platform-independent recursive file-system search library implemented in C++ and providing C and C++ APIs."
    HOMEPAGE_URL "https://github.com/synesissoftware/recls"
    LANGUAGES C CXX
)

string(TOLOWER ${PROJECT_NAME} PROJECT_NAME_LOWER)
string(TOUPPER ${PROJECT_NAME} PROJECT_NAME_UPPER)

# handle version number
set(RX_PROJ_TAG "${PROJECT_NAME_UPPER}")
set(RX_WS "[ \t]")
file(READ "${CMAKE_SOURCE_DIR}/include/${PROJECT_NAME_LOWER}/${PROJECT_NAME_LOWER}.h" _header_file)
string(REGEX MATCH "#${RX_WS}*define${RX_WS}+_?${RX_PROJ_TAG}_VER_MAJOR${RX_WS}+([0-9]+)" MAJOR_DUMMY ${_header_file})
set(_VERSION_MAJOR ${CMAKE_MATCH_1})
string(REGEX MATCH "#${RX_WS}*define${RX_WS}+_?${RX_PROJ_TAG}_VER_MINOR${RX_WS}+([0-9]+)" MINOR_DUMMY ${_header_file})
set(_VERSION_MINOR ${CMAKE_MATCH_1})
string(REGEX MATCH "#${RX_WS}*define${RX_WS}+_?${RX_PROJ_TAG}_VER_REVISION${RX_WS}+([0-9]+)" PATCH_DUMMY ${_header_file})
set(_VERSION_PATCH ${CMAKE_MATCH_1})

# set project version number here
set(PROJECT_VERSION_MAJOR ${_VERSION_MAJOR})
set(PROJECT_VERSION_MINOR ${_VERSION_MINOR})
set(PROJECT_VERSION_PATCH ${_VERSION_PATCH})
set(PROJECT_VERSION "${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}.${PROJECT_VERSION_PATCH}")

message(NOTICE "Generating CMake build scripts for ${PROJECT_NAME} ${PROJECT_VERSION}.")


# adhere strictly to C and C++ standards plus extensions. These are actually
# useless since we do not compile anything; they merely state our intention.
set(CMAKE_C_STANDARD 99)
set(CMAKE_C_STANDARD_REQUIRED ON)
set(CMAKE_C_EXTENSIONS ON) # GNU extensions and POSIX standard
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS ON)


# ##########################################################
# install

# provides install directory variables as defined by the GNU Coding Standards.
include(GNUInstallDirs)


# ##########################################################
# STLSoft
#
# We provide flexibility here, as in:
# 1. if a CMake variable STLSOFT is provided then it is used; otherwise
# 2. if an environment variable STLSOFT is provided then it then it is used; otherwise
# 3. if the package STLSoft (via find_package()) is found then it is used; otherwise
# 4. we abort

if(NOT DEFINED STLSOFT AND NOT DEFINED ENV{STLSOFT})

    set(STLSoft_REQUIRED_VERSION_ 1.10.2)

    find_package(STLSoft ${STLSoft_REQUIRED_VERSION_} REQUIRED)

    message("-- CMake package STLSoft found (version ${STLSoft_VERSION}; ${STLSoft_REQUIRED_VERSION_} requested)")
else()

    if(DEFINED STLSOFT)

        message("-- STLSOFT provided as CMake variable with value ${STLSOFT}")

        set(STLSOFT_INCLUDE_DIR ${STLSOFT}/include)
    else()

        message("-- STLSOFT provided as environment variable with value $ENV{STLSOFT}")

        set(STLSOFT_INCLUDE_DIR $ENV{STLSOFT}/include)
    endif()

    include_directories(${STLSOFT_INCLUDE_DIR})
endif()


# ##########################################################
# build

# load/default `CMAKE_BUILD_TYPE`
include(BuildType)

add_subdirectory(src)


# ##########################################################
# test

include(CTest)

if(BUILD_TESTING)

    set(xTests_REQUIRED_VERSION_ 0.20.4)

    find_package(xTests ${xTests_REQUIRED_VERSION_} REQUIRED)

    message("-- CMake package xTests found (version ${xTests_VERSION}; ${xTests_REQUIRED_VERSION_} requested)")

    add_subdirectory(test)
endif()


# ##########################################################
# examples

option(BUILD_EXAMPLES "Build examples" ON)
if(BUILD_EXAMPLES)

    add_subdirectory(examples)
endif()


# ##########################################################
# install


# ##########################################################
# export

include(CMakePackageConfigHelpers)

string(TOLOWER ${PROJECT_NAME} EXPORT_NAME)

configure_package_config_file(
    ${CMAKE_CURRENT_SOURCE_DIR}/cmake/${EXPORT_NAME}-config.cmake.in
    ${CMAKE_CURRENT_BINARY_DIR}/cmake/${EXPORT_NAME}-config.cmake
    INSTALL_DESTINATION ${LIB_INSTALL_DIR}/${EXPORT_NAME}/cmake
)

write_basic_package_version_file(
    ${CMAKE_CURRENT_BINARY_DIR}/cmake/${EXPORT_NAME}-config-version.cmake
    VERSION ${PROJECT_VERSION}
    COMPATIBILITY AnyNewerVersion
)

export(EXPORT project-targets
    FILE "${CMAKE_CURRENT_BINARY_DIR}/cmake/${EXPORT_NAME}-targets.cmake"
    NAMESPACE "${PROJECT_NAME}::"
)

install(EXPORT project-targets
    NAMESPACE "${PROJECT_NAME}::"
    FILE "${EXPORT_NAME}-targets.cmake"
    DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${EXPORT_NAME}
)

install( FILES
    "${CMAKE_CURRENT_BINARY_DIR}/cmake/${EXPORT_NAME}-config.cmake"
    "${CMAKE_CURRENT_BINARY_DIR}/cmake/${EXPORT_NAME}-config-version.cmake"
    DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/${EXPORT_NAME}
)


# ############################## end of file ############################# #