ext: Upgrade PyBind11 to version 2.1.1

Change-Id: I16870dec402d661295f9d013dc23e362b2b2c169
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/3225
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

1 files changed, 114 insertions, 57 deletions

diff --git a/ext/pybind11/tools/pybind11Tools.cmake b/ext/pybind11/tools/pybind11Tools.cmake
index 4922982fa..3fbffeeff 100644
--- a/ext/pybind11/tools/pybind11Tools.cmake
+++ b/ext/pybind11/tools/pybind11Tools.cmake
@@ -8,12 +8,15 @@
 cmake_minimum_required(VERSION 2.8.12)
 
 # Add a CMake parameter for choosing a desired Python version
-set(PYBIND11_PYTHON_VERSION "" CACHE STRING "Python version to use for compiling modules")
+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)
 
 function(select_cxx_standard)
   if(NOT MSVC AND NOT PYBIND11_CPP_STANDARD)
@@ -33,29 +36,95 @@ function(select_cxx_standard)
   endif()
 endfunction()
 
+# 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] source1 [source2 ...])
+# pybind11_add_module(<name> [MODULE | SHARED] [EXCLUDE_FROM_ALL]
+#                     [NO_EXTRAS] [THIN_LTO] source1 [source2 ...])
 #
 function(pybind11_add_module target_name)
-  set(lib_type "MODULE")
-  set(do_lto True)
-  set(exclude_from_all "")
-  set(sources "")
-
-  set(_args_to_try "${ARGN}")
-  foreach(_ex_arg IN LISTS _args_to_try)
-    if(${_ex_arg} STREQUAL "MODULE")
-      set(lib_type "MODULE")
-    elseif(${_ex_arg} STREQUAL "SHARED")
-      set(lib_type "SHARED")
-    elseif(${_ex_arg} STREQUAL "EXCLUDE_FROM_ALL")
-      set(exclude_from_all "EXCLUDE_FROM_ALL")
-    else()
-      list(APPEND sources "${_ex_arg}")
-    endif()
-  endforeach()
+  set(options MODULE SHARED EXCLUDE_FROM_ALL NO_EXTRAS THIN_LTO)
+  cmake_parse_arguments(ARG "${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()
 
-  add_library(${target_name} ${lib_type} ${exclude_from_all} ${sources})
+  if(ARG_EXCLUDE_FROM_ALL)
+    set(exclude_from_all EXCLUDE_FROM_ALL)
+  endif()
+
+  add_library(${target_name} ${lib_type} ${exclude_from_all} ${ARG_UNPARSED_ARGUMENTS})
 
   target_include_directories(${target_name}
     PRIVATE ${PYBIND11_INCLUDE_DIR}  # from project CMakeLists.txt
@@ -85,56 +154,44 @@ function(pybind11_add_module target_name)
     # 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()
 
   select_cxx_standard()
   if(NOT MSVC)
     # Make sure C++11/14 are enabled
     target_compile_options(${target_name} PUBLIC ${PYBIND11_CPP_STANDARD})
+  endif()
 
-    # Enable link time optimization and set the default symbol
-    # visibility to hidden (very important to obtain small binaries)
-    string(TOUPPER "${CMAKE_BUILD_TYPE}" U_CMAKE_BUILD_TYPE)
-    if (NOT ${U_CMAKE_BUILD_TYPE} MATCHES DEBUG)
-      # Check for Link Time Optimization support (GCC/Clang)
-      check_cxx_compiler_flag("-flto" HAS_LTO_FLAG)
-      if(HAS_LTO_FLAG AND NOT CYGWIN)
-        target_compile_options(${target_name} PRIVATE -flto)
-      endif()
+  if(ARG_NO_EXTRAS)
+    return()
+  endif()
 
-      # Intel equivalent to LTO is called IPO
-      if(CMAKE_CXX_COMPILER_ID MATCHES "Intel")
-        check_cxx_compiler_flag("-ipo" HAS_IPO_FLAG)
-        if(HAS_IPO_FLAG)
-          target_compile_options(${target_name} PRIVATE -ipo)
-        endif()
-      endif()
+  _pybind11_add_lto_flags(${target_name} ${ARG_THIN_LTO})
+
+  if (NOT MSVC AND NOT ${CMAKE_BUILD_TYPE} MATCHES Debug)
+    # Set the default symbol visibility to hidden (very important to obtain small binaries)
+    target_compile_options(${target_name} PRIVATE "-fvisibility=hidden")
 
-      # Default symbol visibility
-      target_compile_options(${target_name} PRIVATE "-fvisibility=hidden")
-
-      # 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} -u -r $<TARGET_FILE:${target_name}>)
-        else()
-          add_custom_command(TARGET ${target_name} POST_BUILD
-                             COMMAND ${CMAKE_STRIP} $<TARGET_FILE:${target_name}>)
-        endif()
+    # 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()
-  elseif(MSVC)
+  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(${target_name} PRIVATE /MP /bigobj)
-
-    # Enforce link time code generation on MSVC, except in debug mode
-    target_compile_options(${target_name} PRIVATE $<$<NOT:$<CONFIG:Debug>>:/GL>)
-
-    # Fancy generator expressions don't work with linker flags, for reasons unknown
-    set_property(TARGET ${target_name} APPEND_STRING PROPERTY LINK_FLAGS_RELEASE /LTCG)
-    set_property(TARGET ${target_name} APPEND_STRING PROPERTY LINK_FLAGS_MINSIZEREL /LTCG)
-    set_property(TARGET ${target_name} APPEND_STRING PROPERTY LINK_FLAGS_RELWITHDEBINFO /LTCG)
   endif()
 endfunction()