CMakeLists.txt

# CMakeLists.txt -- Build system for the pybind11 modules
#
# Copyright (c) 2015 Wenzel Jakob <wenzel@inf.ethz.ch>
#
# All rights reserved. Use of this source code is governed by a
# BSD-style license that can be found in the LICENSE file.

cmake_minimum_required(VERSION 3.7)

# VERSION 3.7...3.18, but some versions of MCVS have a patched CMake 3.11
# that do not work properly with this syntax, so using the following workaround:
if(${CMAKE_VERSION} VERSION_LESS 3.18)
    cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
else()
    cmake_policy(VERSION 3.18)
endif()

# Extract project version from source
file(
  STRINGS
    "${CMAKE_CURRENT_SOURCE_DIR}/include/pybind11/detail/common.h"
  pybind11_version_defines
  REGEX
    "#define PYBIND11_VERSION_(MAJOR|MINOR|PATCH) ")

foreach(ver ${pybind11_version_defines})
    if (ver MATCHES [[#define PYBIND11_VERSION_(MAJOR|MINOR|PATCH) +([^ ]+)$]])
        set(PYBIND11_VERSION_${CMAKE_MATCH_1} "${CMAKE_MATCH_2}")
    endif()
endforeach()

if(PYBIND11_VERSION_PATCH MATCHES [[([a-zA-Z]+)]])
    set(PYBIND11_VERSION_TYPE "${CMAKE_MATCH_1}")
endif()
string(REGEX MATCH "[0-9]+" PYBIND11_VERSION_PATCH "${PYBIND11_VERSION_PATCH}")

project(
    pybind11
  LANGUAGES
    CXX
  VERSION
    "${PYBIND11_VERSION_MAJOR}.${PYBIND11_VERSION_MINOR}.${PYBIND11_VERSION_PATCH}"
)

# Standard includes
include(GNUInstallDirs)
include(CMakePackageConfigHelpers)
include(CMakeDependentOption)

message(STATUS "pybind11 v${pybind11_VERSION} ${PYBIND11_VERSION_TYPE}")

# Check if pybind11 is being used directly or via add_subdirectory
if(CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
    set(PYBIND11_MASTER_PROJECT ON)
    message(STATUS "CMake ${CMAKE_VERSION}")

    if(CMAKE_CXX_STANDARD)
        set(CMAKE_CXX_EXTENSIONS OFF)
        set(CMAKE_CXX_STANDARD_REQUIRED ON)
    endif()
else()
    set(PYBIND11_MASTER_PROJECT OFF)
    set(pybind11_system SYSTEM)
endif()

option(PYBIND11_INSTALL "Install pybind11 header files?" ${PYBIND11_MASTER_PROJECT})
option(PYBIND11_TEST "Build pybind11 test suite?" ${PYBIND11_MASTER_PROJECT})
option(PYBIND11_CLASSIC_LTO "Use the classic LTO flag algorithm, even on CMake 3.9+" OFF)
cmake_dependent_option(
    USE_PYTHON_INCLUDE_DIR
    "Install pybind11 headers in Python include directory instead of default installation prefix" OFF
    "PYBIND11_INSTALL" OFF
)

# NB: when adding a header don't forget to also add it to setup.py
set(PYBIND11_HEADERS
    include/pybind11/detail/class.h
    include/pybind11/detail/common.h
    include/pybind11/detail/descr.h
    include/pybind11/detail/init.h
    include/pybind11/detail/internals.h
    include/pybind11/detail/typeid.h
    include/pybind11/attr.h
    include/pybind11/buffer_info.h
    include/pybind11/cast.h
    include/pybind11/chrono.h
    include/pybind11/common.h
    include/pybind11/complex.h
    include/pybind11/options.h
    include/pybind11/eigen.h
    include/pybind11/embed.h
    include/pybind11/eval.h
    include/pybind11/functional.h
    include/pybind11/numpy.h
    include/pybind11/operators.h
    include/pybind11/pybind11.h
    include/pybind11/pytypes.h
    include/pybind11/stl.h
    include/pybind11/stl_bind.h
)

# TODO: compare with grep and warn if missmatched

# cmake 3.12 added list(TRANSFORM <list> PREPEND
# But we can't use it yet
string(REPLACE "include/" "${CMAKE_CURRENT_SOURCE_DIR}/include/"
       PYBIND11_HEADERS "${PYBIND11_HEADERS}")


# Classic mode

list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/tools")
include(pybind11Tools)

# Cache variables so pybind11_add_module can be used in parent projects
set(PYBIND11_INCLUDE_DIR "${CMAKE_CURRENT_LIST_DIR}/include" CACHE INTERNAL "")
set(PYTHON_INCLUDE_DIRS ${PYTHON_INCLUDE_DIRS} CACHE INTERNAL "")
set(PYTHON_LIBRARIES ${PYTHON_LIBRARIES} CACHE INTERNAL "")
set(PYTHON_MODULE_PREFIX ${PYTHON_MODULE_PREFIX} CACHE INTERNAL "")
set(PYTHON_MODULE_EXTENSION ${PYTHON_MODULE_EXTENSION} CACHE INTERNAL "")
set(PYTHON_VERSION_MAJOR ${PYTHON_VERSION_MAJOR} CACHE INTERNAL "")
set(PYTHON_VERSION_MINOR ${PYTHON_VERSION_MINOR} CACHE INTERNAL "")
set(PYTHON_IS_DEBUG "${PYTHON_IS_DEBUG}" CACHE INTERNAL "")


if(PYBIND11_TEST OR (BUILD_TESTING AND PYBIND11_MASTER_PROJECT))
    add_subdirectory(tests)
endif()


if(USE_PYTHON_INCLUDE_DIR)
    file(RELATIVE_PATH CMAKE_INSTALL_INCLUDEDIR ${CMAKE_INSTALL_PREFIX} ${PYTHON_INCLUDE_DIRS})
endif()

# Note: when creating targets, you cannot use if statements at configure time -
# you need generator expressions, because those will be placed in the target file.
# You can also place ifs *in* the Config.in, but not here.

# Build an interface library target:
add_library(pybind11 INTERFACE)
add_library(pybind11::pybind11 ALIAS pybind11)  # to match exported target

target_include_directories(pybind11 ${pybind11_system} INTERFACE $<BUILD_INTERFACE:${PYBIND11_INCLUDE_DIR}>
                                                                 $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>)
# Only add Python for build - must be added during the import for config since it has to be re-discovered.
target_include_directories(pybind11 SYSTEM INTERFACE $<BUILD_INTERFACE:${PYTHON_INCLUDE_DIRS}>)

if(CMAKE_VERSION VERSION_LESS 3.13)
    target_compile_features(
        pybind11
      INTERFACE
        cxx_inheriting_constructors
        cxx_user_literals
        cxx_right_angle_brackets
      )
else()
    # This was added in CMake 3.8, but we are keeping a consistent breaking
    # point for the config file at 3.13. A config generated by CMake 3.13+
    # can only be read in 3.13+ due to the SHELL usage later, so this is safe to do.
    target_compile_features(pybind11 INTERFACE cxx_std_11)
endif()

add_library(module INTERFACE)
add_library(pybind11::module ALIAS module)

target_link_libraries(module INTERFACE pybind11::pybind11)

# See https://github.com/Kitware/CMake/blob/master/Modules/CMakePlatformId.h.in for platform IDs
# Note: CMake 3.15 allows $<PLATFORM_ID:Windows,Cygwin>
target_link_libraries(module INTERFACE "$<$<OR:$<PLATFORM_ID:Windows>,$<PLATFORM_ID:Cygwin>>:$<BUILD_INTERFACE:${PYTHON_LIBRARIES}>>")

if(CMAKE_VERSION VERSION_LESS 3.13)
    target_link_libraries(module INTERFACE "$<$<PLATFORM_ID:Darwin>:-undefined dynamic_lookup>")
else()
    # SHELL (3.12+) forces this to remain together, and link_options was added in 3.13+
    # This is safer, because you are ensured the deduplication pass in CMake will not consider
    # these separate and remove one but not the other.
    target_link_options(module INTERFACE "$<$<PLATFORM_ID:Darwin>:SHELL:-undefined dynamic_lookup>")
endif()


# Workaround for Python 2.7 and C++17 (C++14 as a warning) incompatibility
# This adds the flags -Wno-register and -Wno-deprecated-register if the compiler
# is Clang 3.9+ or AppleClang and the compile language is CXX, or /wd5033 for MSVC (all languages,
# since MSVC didn't recognize COMPILE_LANGUAGE until CMake 3.11+).
set(clang_4plus "$<AND:$<CXX_COMPILER_ID:Clang>,$<NOT:$<VERSION_LESS:$<CXX_COMPILER_VERSION>,3.9>>>")
set(no_register "$<OR:${clang_4plus},$<CXX_COMPILER_ID:AppleClang>>")
set(cxx_no_register "$<AND:$<COMPILE_LANGUAGE:CXX>,${no_register}>")
set(msvc "$<CXX_COMPILER_ID:MSVC>")
target_compile_options(
  pybind11 INTERFACE "$<${cxx_no_register}:-Wno-register;-Wno-deprecated-register>"
                     "$<${msvc}:/wd5033>")

add_library(embed INTERFACE)
add_library(pybind11::embed ALIAS embed)
target_link_libraries(embed INTERFACE pybind11::pybind11 $<BUILD_INTERFACE:${PYTHON_LIBRARIES}>)

if(PYBIND11_INSTALL)
    install(DIRECTORY ${PYBIND11_INCLUDE_DIR}/pybind11 DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
    # GNUInstallDirs "DATADIR" wrong here; CMake search path wants "share".
    set(PYBIND11_CMAKECONFIG_INSTALL_DIR "share/cmake/${PROJECT_NAME}" CACHE STRING "install path for pybind11Config.cmake")

    configure_package_config_file(tools/${PROJECT_NAME}Config.cmake.in
                                  "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake"
                                  INSTALL_DESTINATION ${PYBIND11_CMAKECONFIG_INSTALL_DIR})

    if(CMAKE_VERSION VERSION_LESS 3.14)
        # Remove CMAKE_SIZEOF_VOID_P from ConfigVersion.cmake since the library does
        # not depend on architecture specific settings or libraries.
        set(_PYBIND11_CMAKE_SIZEOF_VOID_P ${CMAKE_SIZEOF_VOID_P})
        unset(CMAKE_SIZEOF_VOID_P)

        write_basic_package_version_file(
            ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake
          VERSION
            ${PROJECT_VERSION}
          COMPATIBILITY
            AnyNewerVersion
        )

        set(CMAKE_SIZEOF_VOID_P ${_PYBIND11_CMAKE_SIZEOF_VOID_P})
    else()
        # CMake 3.14+ natively supports header-only libraries
        write_basic_package_version_file(
            ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake
          VERSION
            ${PROJECT_VERSION}
          COMPATIBILITY
            AnyNewerVersion
          ARCH_INDEPENDENT
        )
    endif()

    install(
      FILES
        ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}Config.cmake
        ${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake
        tools/FindPythonLibsNew.cmake
        tools/pybind11Tools.cmake
      DESTINATION
        ${PYBIND11_CMAKECONFIG_INSTALL_DIR})

    if(NOT PYBIND11_EXPORT_NAME)
        set(PYBIND11_EXPORT_NAME "${PROJECT_NAME}Targets")
    endif()

    install(TARGETS pybind11 module embed
            EXPORT "${PYBIND11_EXPORT_NAME}")

    install(EXPORT "${PYBIND11_EXPORT_NAME}"
            NAMESPACE "pybind11::"
            DESTINATION ${PYBIND11_CMAKECONFIG_INSTALL_DIR})
endif()