CMakeLists.txt

cmake_minimum_required(VERSION 3.15)

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#
# Project details
#

project(
  "Project"
  VERSION 0.1.0
  DESCRIPTION ""
  LANGUAGES CXX
)

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##
## MAIN_PROJECT CHECK
## determine if project is built as a subproject (using add_subdirectory) or if it is the main project
##
set(MAIN_PROJECT OFF)
if (CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
    set(MAIN_PROJECT ON)
endif()

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##
## Setup the include path
##
##
set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/scripts/cmake ${CMAKE_MODULE_PATH})

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#
# Set project options
#

include(StandardSettings)
include(StaticAnalyzers)
include(Utils)

option(BuildTests "Build the unit tests when BUILD_TESTING is enabled." ${MAIN_PROJECT})
option(CI         "Enable CI build targets." OFF)

if(NOT CMAKE_BUILD_TYPE)
  set(CMAKE_BUILD_TYPE "Debug")
endif()
message(STATUS "Started CMake for ${PROJECT_NAME} v${PROJECT_VERSION}...\n")

if (UNIX)
    add_compile_options("$<$<CONFIG:DEBUG>:-D_DEBUG>")    #this will allow to use same _DEBUG macro available in both Linux as well as Windows - MSCV environment. Easy to put Debug specific code.
endif (UNIX)


if (CI)
    include(ci)
endif ()

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#
# Setup alternative names
#

if(${PROJECT_NAME}_USE_ALT_NAMES)
  string(TOLOWER ${PROJECT_NAME} PROJECT_NAME_LOWERCASE)
  string(TOUPPER ${PROJECT_NAME} PROJECT_NAME_UPPERCASE)
else()
  set(PROJECT_NAME_LOWERCASE ${PROJECT_NAME})
  set(PROJECT_NAME_UPPERCASE ${PROJECT_NAME})
endif()

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#
# Prevent building in the source directory
#

if(PROJECT_SOURCE_DIR STREQUAL PROJECT_BINARY_DIR)
  message(FATAL_ERROR "In-source builds not allowed. Please make a new directory (called a build directory) and run CMake from there.\n")
endif()

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#
# Enable package managers
#

include(Conan)
include(Vcpkg)

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#
# Create library, setup header and source files
#

# Find all headers and implementation files
include(SourcesAndHeaders)

if(${PROJECT_NAME}_BUILD_EXECUTABLE)
  add_executable(${PROJECT_NAME} ${exe_sources})

  if(${PROJECT_NAME}_VERBOSE_OUTPUT)
    verbose_message("Found the following sources:")
    foreach(source IN LISTS exe_sources)
      verbose_message("* ${source}")
    endforeach()
  endif()

  if(${PROJECT_NAME}_ENABLE_UNIT_TESTING)
    add_library(${PROJECT_NAME}_LIB ${headers} ${sources})

    if(${PROJECT_NAME}_VERBOSE_OUTPUT)
      verbose_message("Found the following headers:")
      foreach(header IN LISTS headers)
        verbose_message("* ${header}")
      endforeach()
    endif()
  endif()
elseif(${PROJECT_NAME}_BUILD_HEADERS_ONLY)
  add_library(${PROJECT_NAME} INTERFACE)

  if(${PROJECT_NAME}_VERBOSE_OUTPUT)
    verbose_message("Found the following headers:")
    foreach(header IN LIST headers)
      verbose_message("* ${header}")
    endforeach()
  endif()
else()
  add_library(
    ${PROJECT_NAME}
    ${headers}
    ${sources}
  )

  if(${PROJECT_NAME}_VERBOSE_OUTPUT)
    verbose_message("Found the following sources:")
    foreach(source IN LISTS sources)
      verbose_message("* ${source}")
    endforeach()
    verbose_message("Found the following headers:")
    foreach(header IN LISTS headers)
      verbose_message("* ${header}")
    endforeach()
  endif()
endif()

set_target_properties(
  ${PROJECT_NAME}
  PROPERTIES
  ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib/${CMAKE_BUILD_TYPE}"
  LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib/${CMAKE_BUILD_TYPE}"
  RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin/${CMAKE_BUILD_TYPE}"
)
if(${PROJECT_NAME}_BUILD_EXECUTABLE AND ${PROJECT_NAME}_ENABLE_UNIT_TESTING)
  set_target_properties(
    ${PROJECT_NAME}_LIB
    PROPERTIES
    ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib/${CMAKE_BUILD_TYPE}"
    LIBRARY_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/lib/${CMAKE_BUILD_TYPE}"
    OUTPUT_NAME ${PROJECT_NAME}
  )
endif()

message(STATUS "Added all header and implementation files.\n")

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#
# Set the project standard and warnings
#

if(${PROJECT_NAME}_BUILD_HEADERS_ONLY)
  target_compile_features(${PROJECT_NAME} INTERFACE cxx_std_11)
else()
  target_compile_features(${PROJECT_NAME} PUBLIC cxx_std_11)

  if(${PROJECT_NAME}_BUILD_EXECUTABLE AND ${PROJECT_NAME}_ENABLE_UNIT_TESTING)
    target_compile_features(${PROJECT_NAME}_LIB PUBLIC cxx_std_11)
  endif()
endif()
#include(CompilerWarnings)
#set_project_warnings(${PROJECT_NAME})

verbose_message("Applied compiler warnings. Using standard ${CMAKE_CXX_STANDARD}.\n")

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#
# Enable Doxygen
#

include(Doxygen)

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#
# Model project dependencies
#

# Identify and link with the specific "packages" the project uses
#find_package(package_name package_version REQUIRED package_type [other_options])
#target_link_libraries(
#  ${PROJECT_NAME}
#  PUBLIC
#    dependency1 ...
#  PRIVATE
#    dependency2 ...
#    ${PROJECT_NAME}_PROJECT_OPTIONS
#    ${PROJECT_NAME}_PROJECT_WARNINGS
#)
#if(${PROJECT_NAME}_BUILD_EXECUTABLE AND ${PROJECT_NAME}_ENABLE_UNIT_TESTING)
#  target_link_libraries(
#    ${PROJECT_NAME}_LIB
#    PUBLIC
#      dependency1 ...
#  )
#endif()

# For Windows, it is necessary to link with the MultiThreaded library.
# Depending on how the rest of the project's dependencies are linked, it might be necessary
# to change the line to statically link with the library.
#
# This is done as follows:
#
# set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
#
# On Linux and Mac this variable is ignored. If any issues rise from it, try commenting it out
# and letting CMake decide how to link with it.
set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>DLL")

verbose_message("Successfully added all dependencies and linked against them.")

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#
# Set the build/user include directories
#

# Allow usage of header files in the `src` directory, but only for utilities
if(${PROJECT_NAME}_BUILD_HEADERS_ONLY)
  target_include_directories(
    ${PROJECT_NAME}
    INTERFACE
    $<INSTALL_INTERFACE:include>
    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
  )
else()
  target_include_directories(
    ${PROJECT_NAME}
    PUBLIC
    $<INSTALL_INTERFACE:include>
    $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
    PRIVATE
    ${CMAKE_CURRENT_SOURCE_DIR}/src
    #${PROJECT_SOURCE_DIR}/include
  )
  if(${PROJECT_NAME}_BUILD_EXECUTABLE AND ${PROJECT_NAME}_ENABLE_UNIT_TESTING)
    target_include_directories(
      ${PROJECT_NAME}_LIB
      PUBLIC
      $<INSTALL_INTERFACE:include>
      $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
      PRIVATE
      ${CMAKE_CURRENT_SOURCE_DIR}/src
      #${PROJECT_SOURCE_DIR}/include
    )
  endif()
endif()

message(STATUS "Finished setting up include directories.")

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#
# Provide alias to library for
#

if(${PROJECT_NAME}_BUILD_EXECUTABLE)
  add_executable(${PROJECT_NAME}::${PROJECT_NAME} ALIAS ${PROJECT_NAME})
else()
  add_library(${PROJECT_NAME}::${PROJECT_NAME} ALIAS ${PROJECT_NAME})
endif()

verbose_message("Project is now aliased as ${PROJECT_NAME}::${PROJECT_NAME}.\n")

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#
# Format the project using the `clang-format` target (i.e: cmake --build build --target clang-format)
#

add_clang_format_target()

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#
# Install library for easy downstream inclusion
#

include(GNUInstallDirs)
install(
  TARGETS
  ${PROJECT_NAME}
  EXPORT
  ${PROJECT_NAME}Targets
  LIBRARY DESTINATION
  ${CMAKE_INSTALL_LIBDIR}
  RUNTIME DESTINATION
  ${CMAKE_INSTALL_BINDIR}
  ARCHIVE DESTINATION
  ${CMAKE_INSTALL_LIBDIR}
  INCLUDES DESTINATION
  include
  PUBLIC_HEADER DESTINATION
  include
)

install(
  EXPORT
  ${PROJECT_NAME}Targets
  FILE
  ${PROJECT_NAME}Targets.cmake
  NAMESPACE
  ${PROJECT_NAME}::
  DESTINATION
  ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}
)

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#
# Add version header
#

#configure_file(
#  ${CMAKE_CURRENT_LIST_DIR}/cmake/version.hpp.in
#  include/${PROJECT_NAME_LOWERCASE}/version.hpp
#  @ONLY
#)
#
#install(
#  FILES
#  ${CMAKE_CURRENT_BINARY_DIR}/include/${PROJECT_NAME_LOWERCASE}/version.hpp
#  DESTINATION
#  include/${PROJECT_NAME_LOWERCASE}
#)

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#
# Install the `include` directory
#

install(
  DIRECTORY
  include/${PROJECT_NAME_LOWERCASE}
  DESTINATION
  include
)

verbose_message("Install targets successfully built. Install with `cmake --build <build_directory> --target install --config <build_config>`.")

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#
# Quick `ConfigVersion.cmake` creation
#

#include(CMakePackageConfigHelpers)
#write_basic_package_version_file(
#  ${PROJECT_NAME}ConfigVersion.cmake
#  VERSION
#  ${PROJECT_VERSION}
#  COMPATIBILITY
#  SameMajorVersion
#)

#configure_package_config_file(
#  ${CMAKE_CURRENT_LIST_DIR}/cmake/${PROJECT_NAME}Config.cmake.in
#  ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake
#  INSTALL_DESTINATION
#  ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}
#)
#
#install(
#  FILES
#  ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake
#  ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake
#  DESTINATION
#  ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}
#)

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#
# Generate export header if specified
#

if(${PROJECT_NAME}_GENERATE_EXPORT_HEADER)
  include(GenerateExportHeader)
  generate_export_header(${PROJECT_NAME})
  install(
    FILES
    ${PROJECT_BINARY_DIR}/${PROJECT_NAME_LOWERCASE}_export.h
    DESTINATION
    include
  )

  message(STATUS "Generated the export header `${PROJECT_NAME_LOWERCASE}_export.h` and installed it.")
endif()

message(STATUS "Finished building requirements for installing the package.\n")

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#
# Unit testing setup
#

if(${PROJECT_NAME}_ENABLE_UNIT_TESTING)
  enable_testing()
  message(STATUS "Build unit tests for the project. Tests should always be found in the test folder\n")
  add_subdirectory(test)
endif()