111986Sandreas.sandberg@arm.com# tools/pybind11Tools.cmake -- Build system for the pybind11 modules
211986Sandreas.sandberg@arm.com#
311986Sandreas.sandberg@arm.com# Copyright (c) 2015 Wenzel Jakob <wenzel@inf.ethz.ch>
411986Sandreas.sandberg@arm.com#
511986Sandreas.sandberg@arm.com# All rights reserved. Use of this source code is governed by a
611986Sandreas.sandberg@arm.com# BSD-style license that can be found in the LICENSE file.
711986Sandreas.sandberg@arm.com
811986Sandreas.sandberg@arm.comcmake_minimum_required(VERSION 2.8.12)
911986Sandreas.sandberg@arm.com
1011986Sandreas.sandberg@arm.com# Add a CMake parameter for choosing a desired Python version
1112037Sandreas.sandberg@arm.comif(NOT PYBIND11_PYTHON_VERSION)
1212037Sandreas.sandberg@arm.com  set(PYBIND11_PYTHON_VERSION "" CACHE STRING "Python version to use for compiling modules")
1312037Sandreas.sandberg@arm.comendif()
1411986Sandreas.sandberg@arm.com
1511986Sandreas.sandberg@arm.comset(Python_ADDITIONAL_VERSIONS 3.7 3.6 3.5 3.4)
1611986Sandreas.sandberg@arm.comfind_package(PythonLibsNew ${PYBIND11_PYTHON_VERSION} REQUIRED)
1711986Sandreas.sandberg@arm.com
1811986Sandreas.sandberg@arm.cominclude(CheckCXXCompilerFlag)
1912037Sandreas.sandberg@arm.cominclude(CMakeParseArguments)
2011986Sandreas.sandberg@arm.com
2112391Sjason@lowepower.comif(NOT PYBIND11_CPP_STANDARD AND NOT CMAKE_CXX_STANDARD)
2212391Sjason@lowepower.com  if(NOT MSVC)
2311986Sandreas.sandberg@arm.com    check_cxx_compiler_flag("-std=c++14" HAS_CPP14_FLAG)
2411986Sandreas.sandberg@arm.com
2511986Sandreas.sandberg@arm.com    if (HAS_CPP14_FLAG)
2611986Sandreas.sandberg@arm.com      set(PYBIND11_CPP_STANDARD -std=c++14)
2711986Sandreas.sandberg@arm.com    else()
2812391Sjason@lowepower.com      check_cxx_compiler_flag("-std=c++11" HAS_CPP11_FLAG)
2912391Sjason@lowepower.com      if (HAS_CPP11_FLAG)
3012391Sjason@lowepower.com        set(PYBIND11_CPP_STANDARD -std=c++11)
3112391Sjason@lowepower.com      else()
3212391Sjason@lowepower.com        message(FATAL_ERROR "Unsupported compiler -- pybind11 requires C++11 support!")
3312391Sjason@lowepower.com      endif()
3411986Sandreas.sandberg@arm.com    endif()
3512391Sjason@lowepower.com  elseif(MSVC)
3612391Sjason@lowepower.com    set(PYBIND11_CPP_STANDARD /std:c++14)
3712391Sjason@lowepower.com  endif()
3811986Sandreas.sandberg@arm.com
3912391Sjason@lowepower.com  set(PYBIND11_CPP_STANDARD ${PYBIND11_CPP_STANDARD} CACHE STRING
4012391Sjason@lowepower.com      "C++ standard flag, e.g. -std=c++11, -std=c++14, /std:c++14.  Defaults to C++14 mode." FORCE)
4112391Sjason@lowepower.comendif()
4211986Sandreas.sandberg@arm.com
4312037Sandreas.sandberg@arm.com# Checks whether the given CXX/linker flags can compile and link a cxx file.  cxxflags and
4412037Sandreas.sandberg@arm.com# linkerflags are lists of flags to use.  The result variable is a unique variable name for each set
4512037Sandreas.sandberg@arm.com# of flags: the compilation result will be cached base on the result variable.  If the flags work,
4612037Sandreas.sandberg@arm.com# sets them in cxxflags_out/linkerflags_out internal cache variables (in addition to ${result}).
4712037Sandreas.sandberg@arm.comfunction(_pybind11_return_if_cxx_and_linker_flags_work result cxxflags linkerflags cxxflags_out linkerflags_out)
4812037Sandreas.sandberg@arm.com  set(CMAKE_REQUIRED_LIBRARIES ${linkerflags})
4912037Sandreas.sandberg@arm.com  check_cxx_compiler_flag("${cxxflags}" ${result})
5012037Sandreas.sandberg@arm.com  if (${result})
5112037Sandreas.sandberg@arm.com    set(${cxxflags_out} "${cxxflags}" CACHE INTERNAL "" FORCE)
5212037Sandreas.sandberg@arm.com    set(${linkerflags_out} "${linkerflags}" CACHE INTERNAL "" FORCE)
5312037Sandreas.sandberg@arm.com  endif()
5412037Sandreas.sandberg@arm.comendfunction()
5512037Sandreas.sandberg@arm.com
5612037Sandreas.sandberg@arm.com# Internal: find the appropriate link time optimization flags for this compiler
5712037Sandreas.sandberg@arm.comfunction(_pybind11_add_lto_flags target_name prefer_thin_lto)
5812037Sandreas.sandberg@arm.com  if (NOT DEFINED PYBIND11_LTO_CXX_FLAGS)
5912037Sandreas.sandberg@arm.com    set(PYBIND11_LTO_CXX_FLAGS "" CACHE INTERNAL "")
6012037Sandreas.sandberg@arm.com    set(PYBIND11_LTO_LINKER_FLAGS "" CACHE INTERNAL "")
6112037Sandreas.sandberg@arm.com
6212037Sandreas.sandberg@arm.com    if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
6312037Sandreas.sandberg@arm.com      set(cxx_append "")
6412037Sandreas.sandberg@arm.com      set(linker_append "")
6512037Sandreas.sandberg@arm.com      if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND NOT APPLE)
6612037Sandreas.sandberg@arm.com        # Clang Gold plugin does not support -Os; append -O3 to MinSizeRel builds to override it
6712037Sandreas.sandberg@arm.com        set(linker_append ";$<$<CONFIG:MinSizeRel>:-O3>")
6812037Sandreas.sandberg@arm.com      elseif(CMAKE_CXX_COMPILER_ID MATCHES "GNU")
6912037Sandreas.sandberg@arm.com        set(cxx_append ";-fno-fat-lto-objects")
7012037Sandreas.sandberg@arm.com      endif()
7112037Sandreas.sandberg@arm.com
7212037Sandreas.sandberg@arm.com      if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND prefer_thin_lto)
7312037Sandreas.sandberg@arm.com        _pybind11_return_if_cxx_and_linker_flags_work(HAS_FLTO_THIN
7412037Sandreas.sandberg@arm.com          "-flto=thin${cxx_append}" "-flto=thin${linker_append}"
7512037Sandreas.sandberg@arm.com          PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
7612037Sandreas.sandberg@arm.com      endif()
7712037Sandreas.sandberg@arm.com
7812037Sandreas.sandberg@arm.com      if (NOT HAS_FLTO_THIN)
7912037Sandreas.sandberg@arm.com        _pybind11_return_if_cxx_and_linker_flags_work(HAS_FLTO
8012037Sandreas.sandberg@arm.com          "-flto${cxx_append}" "-flto${linker_append}"
8112037Sandreas.sandberg@arm.com          PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
8212037Sandreas.sandberg@arm.com      endif()
8312037Sandreas.sandberg@arm.com    elseif (CMAKE_CXX_COMPILER_ID MATCHES "Intel")
8412037Sandreas.sandberg@arm.com      # Intel equivalent to LTO is called IPO
8512037Sandreas.sandberg@arm.com      _pybind11_return_if_cxx_and_linker_flags_work(HAS_INTEL_IPO
8612037Sandreas.sandberg@arm.com      "-ipo" "-ipo" PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
8712037Sandreas.sandberg@arm.com    elseif(MSVC)
8812037Sandreas.sandberg@arm.com      # cmake only interprets libraries as linker flags when they start with a - (otherwise it
8912037Sandreas.sandberg@arm.com      # converts /LTCG to \LTCG as if it was a Windows path).  Luckily MSVC supports passing flags
9012037Sandreas.sandberg@arm.com      # with - instead of /, even if it is a bit non-standard:
9112037Sandreas.sandberg@arm.com      _pybind11_return_if_cxx_and_linker_flags_work(HAS_MSVC_GL_LTCG
9212037Sandreas.sandberg@arm.com        "/GL" "-LTCG" PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
9312037Sandreas.sandberg@arm.com    endif()
9412037Sandreas.sandberg@arm.com
9512037Sandreas.sandberg@arm.com    if (PYBIND11_LTO_CXX_FLAGS)
9612037Sandreas.sandberg@arm.com      message(STATUS "LTO enabled")
9712037Sandreas.sandberg@arm.com    else()
9812037Sandreas.sandberg@arm.com      message(STATUS "LTO disabled (not supported by the compiler and/or linker)")
9912037Sandreas.sandberg@arm.com    endif()
10012037Sandreas.sandberg@arm.com  endif()
10112037Sandreas.sandberg@arm.com
10212037Sandreas.sandberg@arm.com  # Enable LTO flags if found, except for Debug builds
10312037Sandreas.sandberg@arm.com  if (PYBIND11_LTO_CXX_FLAGS)
10412037Sandreas.sandberg@arm.com    target_compile_options(${target_name} PRIVATE "$<$<NOT:$<CONFIG:Debug>>:${PYBIND11_LTO_CXX_FLAGS}>")
10512037Sandreas.sandberg@arm.com  endif()
10612037Sandreas.sandberg@arm.com  if (PYBIND11_LTO_LINKER_FLAGS)
10712037Sandreas.sandberg@arm.com    target_link_libraries(${target_name} PRIVATE "$<$<NOT:$<CONFIG:Debug>>:${PYBIND11_LTO_LINKER_FLAGS}>")
10812037Sandreas.sandberg@arm.com  endif()
10912037Sandreas.sandberg@arm.comendfunction()
11012037Sandreas.sandberg@arm.com
11111986Sandreas.sandberg@arm.com# Build a Python extension module:
11212037Sandreas.sandberg@arm.com# pybind11_add_module(<name> [MODULE | SHARED] [EXCLUDE_FROM_ALL]
11314299Sbbruce@ucdavis.edu#                     [NO_EXTRAS] [SYSTEM] [THIN_LTO] source1 [source2 ...])
11411986Sandreas.sandberg@arm.com#
11511986Sandreas.sandberg@arm.comfunction(pybind11_add_module target_name)
11614299Sbbruce@ucdavis.edu  set(options MODULE SHARED EXCLUDE_FROM_ALL NO_EXTRAS SYSTEM THIN_LTO)
11712037Sandreas.sandberg@arm.com  cmake_parse_arguments(ARG "${options}" "" "" ${ARGN})
11811986Sandreas.sandberg@arm.com
11912037Sandreas.sandberg@arm.com  if(ARG_MODULE AND ARG_SHARED)
12012037Sandreas.sandberg@arm.com    message(FATAL_ERROR "Can't be both MODULE and SHARED")
12112037Sandreas.sandberg@arm.com  elseif(ARG_SHARED)
12212037Sandreas.sandberg@arm.com    set(lib_type SHARED)
12312037Sandreas.sandberg@arm.com  else()
12412037Sandreas.sandberg@arm.com    set(lib_type MODULE)
12512037Sandreas.sandberg@arm.com  endif()
12611986Sandreas.sandberg@arm.com
12712037Sandreas.sandberg@arm.com  if(ARG_EXCLUDE_FROM_ALL)
12812037Sandreas.sandberg@arm.com    set(exclude_from_all EXCLUDE_FROM_ALL)
12912037Sandreas.sandberg@arm.com  endif()
13012037Sandreas.sandberg@arm.com
13112037Sandreas.sandberg@arm.com  add_library(${target_name} ${lib_type} ${exclude_from_all} ${ARG_UNPARSED_ARGUMENTS})
13211986Sandreas.sandberg@arm.com
13314299Sbbruce@ucdavis.edu  if(ARG_SYSTEM)
13414299Sbbruce@ucdavis.edu    set(inc_isystem SYSTEM)
13514299Sbbruce@ucdavis.edu  endif()
13614299Sbbruce@ucdavis.edu
13714299Sbbruce@ucdavis.edu  target_include_directories(${target_name} ${inc_isystem}
13811986Sandreas.sandberg@arm.com    PRIVATE ${PYBIND11_INCLUDE_DIR}  # from project CMakeLists.txt
13911986Sandreas.sandberg@arm.com    PRIVATE ${pybind11_INCLUDE_DIR}  # from pybind11Config
14011986Sandreas.sandberg@arm.com    PRIVATE ${PYTHON_INCLUDE_DIRS})
14111986Sandreas.sandberg@arm.com
14214299Sbbruce@ucdavis.edu  # Python debug libraries expose slightly different objects
14314299Sbbruce@ucdavis.edu  # https://docs.python.org/3.6/c-api/intro.html#debugging-builds
14414299Sbbruce@ucdavis.edu  # https://stackoverflow.com/questions/39161202/how-to-work-around-missing-pymodule-create2-in-amd64-win-python35-d-lib
14514299Sbbruce@ucdavis.edu  if(PYTHON_IS_DEBUG)
14614299Sbbruce@ucdavis.edu    target_compile_definitions(${target_name} PRIVATE Py_DEBUG)
14714299Sbbruce@ucdavis.edu  endif()
14814299Sbbruce@ucdavis.edu
14911986Sandreas.sandberg@arm.com  # The prefix and extension are provided by FindPythonLibsNew.cmake
15011986Sandreas.sandberg@arm.com  set_target_properties(${target_name} PROPERTIES PREFIX "${PYTHON_MODULE_PREFIX}")
15111986Sandreas.sandberg@arm.com  set_target_properties(${target_name} PROPERTIES SUFFIX "${PYTHON_MODULE_EXTENSION}")
15211986Sandreas.sandberg@arm.com
15312391Sjason@lowepower.com  # -fvisibility=hidden is required to allow multiple modules compiled against
15412391Sjason@lowepower.com  # different pybind versions to work properly, and for some features (e.g.
15512391Sjason@lowepower.com  # py::module_local).  We force it on everything inside the `pybind11`
15612391Sjason@lowepower.com  # namespace; also turning it on for a pybind module compilation here avoids
15712391Sjason@lowepower.com  # potential warnings or issues from having mixed hidden/non-hidden types.
15812391Sjason@lowepower.com  set_target_properties(${target_name} PROPERTIES CXX_VISIBILITY_PRESET "hidden")
15914299Sbbruce@ucdavis.edu  set_target_properties(${target_name} PROPERTIES CUDA_VISIBILITY_PRESET "hidden")
16012391Sjason@lowepower.com
16111986Sandreas.sandberg@arm.com  if(WIN32 OR CYGWIN)
16211986Sandreas.sandberg@arm.com    # Link against the Python shared library on Windows
16311986Sandreas.sandberg@arm.com    target_link_libraries(${target_name} PRIVATE ${PYTHON_LIBRARIES})
16411986Sandreas.sandberg@arm.com  elseif(APPLE)
16511986Sandreas.sandberg@arm.com    # It's quite common to have multiple copies of the same Python version
16611986Sandreas.sandberg@arm.com    # installed on one's system. E.g.: one copy from the OS and another copy
16711986Sandreas.sandberg@arm.com    # that's statically linked into an application like Blender or Maya.
16811986Sandreas.sandberg@arm.com    # If we link our plugin library against the OS Python here and import it
16911986Sandreas.sandberg@arm.com    # into Blender or Maya later on, this will cause segfaults when multiple
17011986Sandreas.sandberg@arm.com    # conflicting Python instances are active at the same time (even when they
17111986Sandreas.sandberg@arm.com    # are of the same version).
17211986Sandreas.sandberg@arm.com
17311986Sandreas.sandberg@arm.com    # Windows is not affected by this issue since it handles DLL imports
17411986Sandreas.sandberg@arm.com    # differently. The solution for Linux and Mac OS is simple: we just don't
17511986Sandreas.sandberg@arm.com    # link against the Python library. The resulting shared library will have
17611986Sandreas.sandberg@arm.com    # missing symbols, but that's perfectly fine -- they will be resolved at
17711986Sandreas.sandberg@arm.com    # import time.
17811986Sandreas.sandberg@arm.com
17911986Sandreas.sandberg@arm.com    target_link_libraries(${target_name} PRIVATE "-undefined dynamic_lookup")
18012037Sandreas.sandberg@arm.com
18112037Sandreas.sandberg@arm.com    if(ARG_SHARED)
18212037Sandreas.sandberg@arm.com      # Suppress CMake >= 3.0 warning for shared libraries
18312037Sandreas.sandberg@arm.com      set_target_properties(${target_name} PROPERTIES MACOSX_RPATH ON)
18412037Sandreas.sandberg@arm.com    endif()
18511986Sandreas.sandberg@arm.com  endif()
18611986Sandreas.sandberg@arm.com
18712391Sjason@lowepower.com  # Make sure C++11/14 are enabled
18814299Sbbruce@ucdavis.edu  if(CMAKE_VERSION VERSION_LESS 3.3)
18914299Sbbruce@ucdavis.edu    target_compile_options(${target_name} PUBLIC ${PYBIND11_CPP_STANDARD})
19014299Sbbruce@ucdavis.edu  else()
19114299Sbbruce@ucdavis.edu    target_compile_options(${target_name} PUBLIC $<$<COMPILE_LANGUAGE:CXX>:${PYBIND11_CPP_STANDARD}>)
19214299Sbbruce@ucdavis.edu  endif()
19311986Sandreas.sandberg@arm.com
19412037Sandreas.sandberg@arm.com  if(ARG_NO_EXTRAS)
19512037Sandreas.sandberg@arm.com    return()
19612037Sandreas.sandberg@arm.com  endif()
19711986Sandreas.sandberg@arm.com
19812037Sandreas.sandberg@arm.com  _pybind11_add_lto_flags(${target_name} ${ARG_THIN_LTO})
19911986Sandreas.sandberg@arm.com
20014299Sbbruce@ucdavis.edu  if (NOT MSVC AND NOT ${CMAKE_BUILD_TYPE} MATCHES Debug|RelWithDebInfo)
20112037Sandreas.sandberg@arm.com    # Strip unnecessary sections of the binary on Linux/Mac OS
20212037Sandreas.sandberg@arm.com    if(CMAKE_STRIP)
20312037Sandreas.sandberg@arm.com      if(APPLE)
20412037Sandreas.sandberg@arm.com        add_custom_command(TARGET ${target_name} POST_BUILD
20512037Sandreas.sandberg@arm.com                           COMMAND ${CMAKE_STRIP} -x $<TARGET_FILE:${target_name}>)
20612037Sandreas.sandberg@arm.com      else()
20712037Sandreas.sandberg@arm.com        add_custom_command(TARGET ${target_name} POST_BUILD
20812037Sandreas.sandberg@arm.com                           COMMAND ${CMAKE_STRIP} $<TARGET_FILE:${target_name}>)
20911986Sandreas.sandberg@arm.com      endif()
21011986Sandreas.sandberg@arm.com    endif()
21112037Sandreas.sandberg@arm.com  endif()
21212037Sandreas.sandberg@arm.com
21312037Sandreas.sandberg@arm.com  if(MSVC)
21411986Sandreas.sandberg@arm.com    # /MP enables multithreaded builds (relevant when there are many files), /bigobj is
21511986Sandreas.sandberg@arm.com    # needed for bigger binding projects due to the limit to 64k addressable sections
21614299Sbbruce@ucdavis.edu    target_compile_options(${target_name} PRIVATE /bigobj)
21714299Sbbruce@ucdavis.edu    if(CMAKE_VERSION VERSION_LESS 3.11)
21814299Sbbruce@ucdavis.edu      target_compile_options(${target_name} PRIVATE $<$<NOT:$<CONFIG:Debug>>:/MP>)
21914299Sbbruce@ucdavis.edu    else()
22014299Sbbruce@ucdavis.edu      # Only set these options for C++ files.  This is important so that, for
22114299Sbbruce@ucdavis.edu      # instance, projects that include other types of source files like CUDA
22214299Sbbruce@ucdavis.edu      # .cu files don't get these options propagated to nvcc since that would
22314299Sbbruce@ucdavis.edu      # cause the build to fail.
22414299Sbbruce@ucdavis.edu      target_compile_options(${target_name} PRIVATE $<$<NOT:$<CONFIG:Debug>>:$<$<COMPILE_LANGUAGE:CXX>:/MP>>)
22514299Sbbruce@ucdavis.edu    endif()
22611986Sandreas.sandberg@arm.com  endif()
22711986Sandreas.sandberg@arm.comendfunction()
228