From: Martin Quinson <martin.quinson@ens-rennes.fr>
Date: Fri, 7 Jun 2019 06:06:18 +0000 (+0200)
Subject: cmake: Try harder to detect pybind11 when it's there and survive when not
X-Git-Tag: v3.23~58
X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/commitdiff_plain/8e67e721f232a3d920e1eaf2f3c8c0b05fe36c07

cmake: Try harder to detect pybind11 when it's there and survive when not

This removes some cmake files that are internal to pybind11, because
on ubuntu-lts, there were a mismatch where it was taking the
system pybind11Config but the version of pybind11Tools that we
provide. The (older) system file was using a cmake function that is
not provided anymore by our recent pybind11Tools.

After this change, our pybind11Config is the upstream-provided one to
the exception that it survives to the absence of pybind11Tools (that
we don't provide). So two cases remain:

- our modified pybind11Config finds a usable pybind11Tools. This must
  be a system-wide pybind11Tools, meaning that pybin11 is installed and
  usable.
- our modified pybind11Config does not find any pybind11Tools. Don't
  try to use pybind11, but keep compiling SimGrid.
---

diff --git a/tools/cmake/Modules/pybind11Config.cmake b/tools/cmake/Modules/pybind11Config.cmake
index c1f3c419c5..e70847b2fd 100644
--- a/tools/cmake/Modules/pybind11Config.cmake
+++ b/tools/cmake/Modules/pybind11Config.cmake
@@ -1,6 +1,9 @@
 # pybind11Config.cmake
 # --------------------
 #
+# Edited for simgrid so that we survive when pybind11Tools is not found, 
+# concluding that pybind11 is not installed. Original version was 2.2.4-2.
+#
 # PYBIND11 cmake module.
 # This module sets the following variables in your project::
 #
@@ -97,9 +100,10 @@ check_required_components(${PN})
 # make detectable the FindPythonLibsNew.cmake module
 list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR})
 
-include(pybind11Tools)
+# SimGrid edit: survive to the fact that pybind11Tools is not found, but stop searching when it happens
+include(pybind11Tools OPTIONAL RESULT_VARIABLE found_pybind11_tools)
 
-if(NOT (CMAKE_VERSION VERSION_LESS 3.0))
+if((NOT (found_pybind11_tools STREQUAL "NOT_FOUND")) AND (NOT (CMAKE_VERSION VERSION_LESS 3.0)))
 #-----------------------------------------------------------------------------
 # Don't include targets if this file is being picked up by another
 # project which has already built this as a subproject
@@ -122,3 +126,4 @@ if(NOT TARGET ${PN}::pybind11)
     set(${PN}_LIBRARIES ${_ico} ${_ill})
 endif()
 endif()
+unset(found_pybind11tools)
diff --git a/tools/cmake/Modules/pybind11ConfigVersion.cmake b/tools/cmake/Modules/pybind11ConfigVersion.cmake
deleted file mode 100644
index c7142d2a2d..0000000000
--- a/tools/cmake/Modules/pybind11ConfigVersion.cmake
+++ /dev/null
@@ -1,31 +0,0 @@
-# This is a basic version file for the Config-mode of find_package().
-# It is used by write_basic_package_version_file() as input file for configure_file()
-# to create a version-file which can be installed along a config.cmake file.
-#
-# The created file sets PACKAGE_VERSION_EXACT if the current version string and
-# the requested version string are exactly the same and it sets
-# PACKAGE_VERSION_COMPATIBLE if the current version is >= requested version.
-# The variable CVF_VERSION must be set before calling configure_file().
-
-set(PACKAGE_VERSION "2.2.4")
-
-if(PACKAGE_VERSION VERSION_LESS PACKAGE_FIND_VERSION)
-  set(PACKAGE_VERSION_COMPATIBLE FALSE)
-else()
-  set(PACKAGE_VERSION_COMPATIBLE TRUE)
-  if(PACKAGE_FIND_VERSION STREQUAL PACKAGE_VERSION)
-    set(PACKAGE_VERSION_EXACT TRUE)
-  endif()
-endif()
-
-# if the installed or the using project don't have CMAKE_SIZEOF_VOID_P set, ignore it:
-if("${CMAKE_SIZEOF_VOID_P}" STREQUAL "" OR "" STREQUAL "")
-   return()
-endif()
-
-# check that the installed version has the same 32/64bit-ness as the one which is currently searching:
-if(NOT CMAKE_SIZEOF_VOID_P STREQUAL "")
-   math(EXPR installedBits " * 8")
-   set(PACKAGE_VERSION "${PACKAGE_VERSION} (${installedBits}bit)")
-   set(PACKAGE_VERSION_UNSUITABLE TRUE)
-endif()
diff --git a/tools/cmake/Modules/pybind11Targets.cmake b/tools/cmake/Modules/pybind11Targets.cmake
deleted file mode 100644
index 1575a47cd6..0000000000
--- a/tools/cmake/Modules/pybind11Targets.cmake
+++ /dev/null
@@ -1,113 +0,0 @@
-# Generated by CMake
-
-if("${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION}" LESS 2.5)
-   message(FATAL_ERROR "CMake >= 2.6.0 required")
-endif()
-cmake_policy(PUSH)
-cmake_policy(VERSION 2.6)
-#----------------------------------------------------------------
-# Generated CMake target import file.
-#----------------------------------------------------------------
-
-# Commands may need to know the format version.
-set(CMAKE_IMPORT_FILE_VERSION 1)
-
-# Protect against multiple inclusion, which would fail when already imported targets are added once more.
-set(_targetsDefined)
-set(_targetsNotDefined)
-set(_expectedTargets)
-foreach(_expectedTarget pybind11::pybind11 pybind11::module pybind11::embed)
-  list(APPEND _expectedTargets ${_expectedTarget})
-  if(NOT TARGET ${_expectedTarget})
-    list(APPEND _targetsNotDefined ${_expectedTarget})
-  endif()
-  if(TARGET ${_expectedTarget})
-    list(APPEND _targetsDefined ${_expectedTarget})
-  endif()
-endforeach()
-if("${_targetsDefined}" STREQUAL "${_expectedTargets}")
-  unset(_targetsDefined)
-  unset(_targetsNotDefined)
-  unset(_expectedTargets)
-  set(CMAKE_IMPORT_FILE_VERSION)
-  cmake_policy(POP)
-  return()
-endif()
-if(NOT "${_targetsDefined}" STREQUAL "")
-  message(FATAL_ERROR "Some (but not all) targets in this export set were already defined.\nTargets Defined: ${_targetsDefined}\nTargets not yet defined: ${_targetsNotDefined}\n")
-endif()
-unset(_targetsDefined)
-unset(_targetsNotDefined)
-unset(_expectedTargets)
-
-
-# Compute the installation prefix relative to this file.
-get_filename_component(_IMPORT_PREFIX "${CMAKE_CURRENT_LIST_FILE}" PATH)
-get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
-get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
-get_filename_component(_IMPORT_PREFIX "${_IMPORT_PREFIX}" PATH)
-if(_IMPORT_PREFIX STREQUAL "/")
-  set(_IMPORT_PREFIX "")
-endif()
-
-# Create imported target pybind11::pybind11
-add_library(pybind11::pybind11 INTERFACE IMPORTED)
-
-set_target_properties(pybind11::pybind11 PROPERTIES
-  INTERFACE_INCLUDE_DIRECTORIES "${_IMPORT_PREFIX}/include"
-)
-
-# Create imported target pybind11::module
-add_library(pybind11::module INTERFACE IMPORTED)
-
-set_target_properties(pybind11::module PROPERTIES
-  INTERFACE_COMPILE_OPTIONS "-fvisibility=hidden"
-  INTERFACE_LINK_LIBRARIES "pybind11::pybind11"
-)
-
-# Create imported target pybind11::embed
-add_library(pybind11::embed INTERFACE IMPORTED)
-
-set_target_properties(pybind11::embed PROPERTIES
-  INTERFACE_LINK_LIBRARIES "pybind11::pybind11"
-)
-
-if(CMAKE_VERSION VERSION_LESS 3.0.0)
-  message(FATAL_ERROR "This file relies on consumers using CMake 3.0.0 or greater.")
-endif()
-
-# Load information for each installed configuration.
-get_filename_component(_DIR "${CMAKE_CURRENT_LIST_FILE}" PATH)
-file(GLOB CONFIG_FILES "${_DIR}/pybind11Targets-*.cmake")
-foreach(f ${CONFIG_FILES})
-  include(${f})
-endforeach()
-
-# Cleanup temporary variables.
-set(_IMPORT_PREFIX)
-
-# Loop over all imported files and verify that they actually exist
-foreach(target ${_IMPORT_CHECK_TARGETS} )
-  foreach(file ${_IMPORT_CHECK_FILES_FOR_${target}} )
-    if(NOT EXISTS "${file}" )
-      message(FATAL_ERROR "The imported target \"${target}\" references the file
-   \"${file}\"
-but this file does not exist.  Possible reasons include:
-* The file was deleted, renamed, or moved to another location.
-* An install or uninstall procedure did not complete successfully.
-* The installation package was faulty and contained
-   \"${CMAKE_CURRENT_LIST_FILE}\"
-but not all the files it references.
-")
-    endif()
-  endforeach()
-  unset(_IMPORT_CHECK_FILES_FOR_${target})
-endforeach()
-unset(_IMPORT_CHECK_TARGETS)
-
-# This file does not depend on other imported targets which have
-# been exported from the same project but in a separate export set.
-
-# Commands beyond this point should not need to know the version.
-set(CMAKE_IMPORT_FILE_VERSION)
-cmake_policy(POP)
diff --git a/tools/cmake/Modules/pybind11Tools.cmake b/tools/cmake/Modules/pybind11Tools.cmake
deleted file mode 100644
index 52a70c23c4..0000000000
--- a/tools/cmake/Modules/pybind11Tools.cmake
+++ /dev/null
@@ -1,209 +0,0 @@
-# tools/pybind11Tools.cmake -- 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 2.8.12)
-
-# Add a CMake parameter for choosing a desired Python version
-if(NOT PYBIND11_PYTHON_VERSION)
-  set(PYBIND11_PYTHON_VERSION "" CACHE STRING "Python version to use for compiling modules")
-endif()
-
-set(Python_ADDITIONAL_VERSIONS 3.7 3.6 3.5 3.4)
-find_package(PythonLibsNew ${PYBIND11_PYTHON_VERSION} REQUIRED)
-
-include(CheckCXXCompilerFlag)
-include(CMakeParseArguments)
-
-if(NOT PYBIND11_CPP_STANDARD AND NOT CMAKE_CXX_STANDARD)
-  if(NOT MSVC)
-    check_cxx_compiler_flag("-std=c++14" HAS_CPP14_FLAG)
-
-    if (HAS_CPP14_FLAG)
-      set(PYBIND11_CPP_STANDARD -std=c++14)
-    else()
-      check_cxx_compiler_flag("-std=c++11" HAS_CPP11_FLAG)
-      if (HAS_CPP11_FLAG)
-        set(PYBIND11_CPP_STANDARD -std=c++11)
-      else()
-        message(FATAL_ERROR "Unsupported compiler -- pybind11 requires C++11 support!")
-      endif()
-    endif()
-  elseif(MSVC)
-    set(PYBIND11_CPP_STANDARD /std:c++14)
-  endif()
-
-  set(PYBIND11_CPP_STANDARD ${PYBIND11_CPP_STANDARD} CACHE STRING
-      "C++ standard flag, e.g. -std=c++11, -std=c++14, /std:c++14.  Defaults to C++14 mode." FORCE)
-endif()
-
-# Checks whether the given CXX/linker flags can compile and link a cxx file.  cxxflags and
-# linkerflags are lists of flags to use.  The result variable is a unique variable name for each set
-# of flags: the compilation result will be cached base on the result variable.  If the flags work,
-# sets them in cxxflags_out/linkerflags_out internal cache variables (in addition to ${result}).
-function(_pybind11_return_if_cxx_and_linker_flags_work result cxxflags linkerflags cxxflags_out linkerflags_out)
-  set(CMAKE_REQUIRED_LIBRARIES ${linkerflags})
-  check_cxx_compiler_flag("${cxxflags}" ${result})
-  if (${result})
-    set(${cxxflags_out} "${cxxflags}" CACHE INTERNAL "" FORCE)
-    set(${linkerflags_out} "${linkerflags}" CACHE INTERNAL "" FORCE)
-  endif()
-endfunction()
-
-# Internal: find the appropriate link time optimization flags for this compiler
-function(_pybind11_add_lto_flags target_name prefer_thin_lto)
-  if (NOT DEFINED PYBIND11_LTO_CXX_FLAGS)
-    set(PYBIND11_LTO_CXX_FLAGS "" CACHE INTERNAL "")
-    set(PYBIND11_LTO_LINKER_FLAGS "" CACHE INTERNAL "")
-
-    if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
-      set(cxx_append "")
-      set(linker_append "")
-      if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND NOT APPLE)
-        # Clang Gold plugin does not support -Os; append -O3 to MinSizeRel builds to override it
-        set(linker_append ";$<$<CONFIG:MinSizeRel>:-O3>")
-      elseif(CMAKE_CXX_COMPILER_ID MATCHES "GNU")
-        set(cxx_append ";-fno-fat-lto-objects")
-      endif()
-
-      if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND prefer_thin_lto)
-        _pybind11_return_if_cxx_and_linker_flags_work(HAS_FLTO_THIN
-          "-flto=thin${cxx_append}" "-flto=thin${linker_append}"
-          PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
-      endif()
-
-      if (NOT HAS_FLTO_THIN)
-        _pybind11_return_if_cxx_and_linker_flags_work(HAS_FLTO
-          "-flto${cxx_append}" "-flto${linker_append}"
-          PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
-      endif()
-    elseif (CMAKE_CXX_COMPILER_ID MATCHES "Intel")
-      # Intel equivalent to LTO is called IPO
-      _pybind11_return_if_cxx_and_linker_flags_work(HAS_INTEL_IPO
-      "-ipo" "-ipo" PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
-    elseif(MSVC)
-      # cmake only interprets libraries as linker flags when they start with a - (otherwise it
-      # converts /LTCG to \LTCG as if it was a Windows path).  Luckily MSVC supports passing flags
-      # with - instead of /, even if it is a bit non-standard:
-      _pybind11_return_if_cxx_and_linker_flags_work(HAS_MSVC_GL_LTCG
-        "/GL" "-LTCG" PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
-    endif()
-
-    if (PYBIND11_LTO_CXX_FLAGS)
-      message(STATUS "LTO enabled")
-    else()
-      message(STATUS "LTO disabled (not supported by the compiler and/or linker)")
-    endif()
-  endif()
-
-  # Enable LTO flags if found, except for Debug builds
-  if (PYBIND11_LTO_CXX_FLAGS)
-    target_compile_options(${target_name} PRIVATE "$<$<NOT:$<CONFIG:Debug>>:${PYBIND11_LTO_CXX_FLAGS}>")
-  endif()
-  if (PYBIND11_LTO_LINKER_FLAGS)
-    target_link_libraries(${target_name} PRIVATE "$<$<NOT:$<CONFIG:Debug>>:${PYBIND11_LTO_LINKER_FLAGS}>")
-  endif()
-endfunction()
-
-# Build a Python extension module:
-# pybind11_add_module(<name> [MODULE | SHARED] [EXCLUDE_FROM_ALL]
-#                     [NO_EXTRAS] [THIN_LTO] source1 [source2 ...])
-#
-function(pybind11_add_module target_name)
-  set(options MODULE SHARED EXCLUDE_FROM_ALL NO_EXTRAS THIN_LTO)
-  cmake_parse_arguments(ARG "${options}" "" "" ${ARGN})
-
-  if(ARG_MODULE AND ARG_SHARED)
-    message(FATAL_ERROR "Can't be both MODULE and SHARED")
-  elseif(ARG_SHARED)
-    set(lib_type SHARED)
-  else()
-    set(lib_type MODULE)
-  endif()
-
-  if(ARG_EXCLUDE_FROM_ALL)
-    set(exclude_from_all EXCLUDE_FROM_ALL)
-  endif()
-
-  add_library(${target_name} ${lib_type} ${exclude_from_all} ${ARG_UNPARSED_ARGUMENTS})
-
-  target_include_directories(${target_name}
-    PRIVATE ${PYBIND11_INCLUDE_DIR}  # from project CMakeLists.txt
-    PRIVATE ${pybind11_INCLUDE_DIR}  # from pybind11Config
-    PRIVATE ${PYTHON_INCLUDE_DIRS})
-
-  # Python debug libraries expose slightly different objects
-  # https://docs.python.org/3.6/c-api/intro.html#debugging-builds
-  # https://stackoverflow.com/questions/39161202/how-to-work-around-missing-pymodule-create2-in-amd64-win-python35-d-lib
-  if(PYTHON_IS_DEBUG)
-    target_compile_definitions(${target_name} PRIVATE Py_DEBUG)
-  endif()
-
-  # The prefix and extension are provided by FindPythonLibsNew.cmake
-  set_target_properties(${target_name} PROPERTIES PREFIX "${PYTHON_MODULE_PREFIX}")
-  set_target_properties(${target_name} PROPERTIES SUFFIX "${PYTHON_MODULE_EXTENSION}")
-
-  # -fvisibility=hidden is required to allow multiple modules compiled against
-  # different pybind versions to work properly, and for some features (e.g.
-  # py::module_local).  We force it on everything inside the `pybind11`
-  # namespace; also turning it on for a pybind module compilation here avoids
-  # potential warnings or issues from having mixed hidden/non-hidden types.
-  set_target_properties(${target_name} PROPERTIES CXX_VISIBILITY_PRESET "hidden")
-
-  if(WIN32 OR CYGWIN)
-    # Link against the Python shared library on Windows
-    target_link_libraries(${target_name} PRIVATE ${PYTHON_LIBRARIES})
-  elseif(APPLE)
-    # It's quite common to have multiple copies of the same Python version
-    # installed on one's system. E.g.: one copy from the OS and another copy
-    # that's statically linked into an application like Blender or Maya.
-    # If we link our plugin library against the OS Python here and import it
-    # into Blender or Maya later on, this will cause segfaults when multiple
-    # conflicting Python instances are active at the same time (even when they
-    # are of the same version).
-
-    # Windows is not affected by this issue since it handles DLL imports
-    # differently. The solution for Linux and Mac OS is simple: we just don't
-    # link against the Python library. The resulting shared library will have
-    # missing symbols, but that's perfectly fine -- they will be resolved at
-    # import time.
-
-    target_link_libraries(${target_name} PRIVATE "-undefined dynamic_lookup")
-
-    if(ARG_SHARED)
-      # Suppress CMake >= 3.0 warning for shared libraries
-      set_target_properties(${target_name} PROPERTIES MACOSX_RPATH ON)
-    endif()
-  endif()
-
-  # Make sure C++11/14 are enabled
-  target_compile_options(${target_name} PUBLIC ${PYBIND11_CPP_STANDARD})
-
-  if(ARG_NO_EXTRAS)
-    return()
-  endif()
-
-  _pybind11_add_lto_flags(${target_name} ${ARG_THIN_LTO})
-
-  if (NOT MSVC AND NOT ${CMAKE_BUILD_TYPE} MATCHES Debug)
-    # Strip unnecessary sections of the binary on Linux/Mac OS
-    if(CMAKE_STRIP)
-      if(APPLE)
-        add_custom_command(TARGET ${target_name} POST_BUILD
-                           COMMAND ${CMAKE_STRIP} -x $<TARGET_FILE:${target_name}>)
-      else()
-        add_custom_command(TARGET ${target_name} POST_BUILD
-                           COMMAND ${CMAKE_STRIP} $<TARGET_FILE:${target_name}>)
-      endif()
-    endif()
-  endif()
-
-  if(MSVC)
-    # /MP enables multithreaded builds (relevant when there are many files), /bigobj is
-    # needed for bigger binding projects due to the limit to 64k addressable sections
-    target_compile_options(${target_name} PRIVATE /MP /bigobj)
-  endif()
-endfunction()