diff -r ae6706411b24 -r f87ed83568c8 cmake_modules/CheckTypeSize.cmake
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cmake_modules/CheckTypeSize.cmake	Thu Apr 21 11:54:21 2016 -0400
@@ -0,0 +1,231 @@
+#.rst:
+# CheckTypeSize
+# -------------
+#
+# Check sizeof a type
+#
+# ::
+#
+#   CHECK_TYPE_SIZE(TYPE VARIABLE [BUILTIN_TYPES_ONLY]
+#                                 [LANGUAGE <language>])
+#
+# Check if the type exists and determine its size.  On return,
+# "HAVE_${VARIABLE}" holds the existence of the type, and "${VARIABLE}"
+# holds one of the following:
+#
+# ::
+#
+#    <size> = type has non-zero size <size>
+#    "0"    = type has arch-dependent size (see below)
+#    ""     = type does not exist
+#
+# Both ``HAVE_${VARIABLE}`` and ``${VARIABLE}`` will be created as internal
+# cache variables.
+#
+# Furthermore, the variable "${VARIABLE}_CODE" holds C preprocessor code
+# to define the macro "${VARIABLE}" to the size of the type, or leave
+# the macro undefined if the type does not exist.
+#
+# The variable "${VARIABLE}" may be "0" when CMAKE_OSX_ARCHITECTURES has
+# multiple architectures for building OS X universal binaries.  This
+# indicates that the type size varies across architectures.  In this
+# case "${VARIABLE}_CODE" contains C preprocessor tests mapping from
+# each architecture macro to the corresponding type size.  The list of
+# architecture macros is stored in "${VARIABLE}_KEYS", and the value for
+# each key is stored in "${VARIABLE}-${KEY}".
+#
+# If the BUILTIN_TYPES_ONLY option is not given, the macro checks for
+# headers <sys/types.h>, <stdint.h>, and <stddef.h>, and saves results
+# in HAVE_SYS_TYPES_H, HAVE_STDINT_H, and HAVE_STDDEF_H.  The type size
+# check automatically includes the available headers, thus supporting
+# checks of types defined in the headers.
+#
+# If LANGUAGE is set, the specified compiler will be used to perform the
+# check. Acceptable values are C and CXX
+#
+# Despite the name of the macro you may use it to check the size of more
+# complex expressions, too.  To check e.g.  for the size of a struct
+# member you can do something like this:
+#
+# ::
+#
+#   check_type_size("((struct something*)0)->member" SIZEOF_MEMBER)
+#
+#
+#
+# The following variables may be set before calling this macro to modify
+# the way the check is run:
+#
+# ::
+#
+#   CMAKE_REQUIRED_FLAGS = string of compile command line flags
+#   CMAKE_REQUIRED_DEFINITIONS = list of macros to define (-DFOO=bar)
+#   CMAKE_REQUIRED_INCLUDES = list of include directories
+#   CMAKE_REQUIRED_LIBRARIES = list of libraries to link
+#   CMAKE_REQUIRED_QUIET = execute quietly without messages
+#   CMAKE_EXTRA_INCLUDE_FILES = list of extra headers to include
+
+#=============================================================================
+# Copyright 2002-2009 Kitware, Inc.
+#
+# Distributed under the OSI-approved BSD License (the "License");
+# see accompanying file Copyright.txt for details.
+#
+# This software is distributed WITHOUT ANY WARRANTY; without even the
+# implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+# See the License for more information.
+#=============================================================================
+# (To distribute this file outside of CMake, substitute the full
+#  License text for the above reference.)
+
+include(CheckIncludeFile)
+include(CheckIncludeFileCXX)
+
+cmake_policy(PUSH)
+cmake_policy(VERSION 3.0)
+
+get_filename_component(__check_type_size_dir "${CMAKE_CURRENT_LIST_FILE}" PATH)
+
+#-----------------------------------------------------------------------------
+# Helper function.  DO NOT CALL DIRECTLY.
+function(__check_type_size_impl type var map builtin language)
+  if(NOT CMAKE_REQUIRED_QUIET)
+    message(STATUS "Check size of ${type}")
+  endif()
+
+  # Include header files.
+  set(headers)
+  if(builtin)
+    if(HAVE_SYS_TYPES_H)
+      set(headers "${headers}#include <sys/types.h>\n")
+    endif()
+    if(HAVE_STDINT_H)
+      set(headers "${headers}#include <stdint.h>\n")
+    endif()
+    if(HAVE_STDDEF_H)
+      set(headers "${headers}#include <stddef.h>\n")
+    endif()
+  endif()
+  foreach(h ${CMAKE_EXTRA_INCLUDE_FILES})
+    set(headers "${headers}#include \"${h}\"\n")
+  endforeach()
+
+  # Perform the check.
+
+  if("${language}" STREQUAL "C")
+    set(src ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CheckTypeSize/${var}.c)
+  elseif("${language}" STREQUAL "CXX")
+    set(src ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CheckTypeSize/${var}.cpp)
+  else()
+    message(FATAL_ERROR "Unknown language:\n  ${language}\nSupported languages: C, CXX.\n")
+  endif()
+  set(bin ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CheckTypeSize/${var}.bin)
+  configure_file(${__check_type_size_dir}/CheckTypeSize.c.in ${src} @ONLY)
+  try_run(${var}_run_result HAVE_${var} ${CMAKE_BINARY_DIR} ${src}
+    COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
+    LINK_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES}
+    CMAKE_FLAGS
+      "-DCOMPILE_DEFINITIONS:STRING=${CMAKE_REQUIRED_FLAGS}"
+      "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}"
+    RUN_OUTPUT_VARIABLE ${var}_run_output
+    COMPILE_OUTPUT_VARIABLE output
+    )
+
+  if(${HAVE_${var}} AND NOT "${${var}_run_result}" STREQUAL "FAILED_TO_RUN")
+    set(${var} ${${var}_run_result})
+    if(NOT CMAKE_REQUIRED_QUIET)
+      message(STATUS "Check size of ${type} - done")
+    endif()
+    file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+      "Determining size of ${type} passed with the following output:\n${output}\n\n")
+    set(${var} "${${var}}" CACHE INTERNAL "CHECK_TYPE_SIZE: sizeof(${type})")
+  else()
+    # The check failed to compile.
+    if(NOT CMAKE_REQUIRED_QUIET)
+      message(STATUS "Check size of ${type} - failed")
+    endif()
+    file(READ ${src} content)
+    file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+      "Determining size of ${type} failed with the following output:\n${output}\n${src}:\n${content}\n\n")
+    set(${var} "" CACHE INTERNAL "CHECK_TYPE_SIZE: ${type} unknown")
+    file(REMOVE ${map})
+  endif()
+endfunction()
+
+#-----------------------------------------------------------------------------
+macro(CHECK_TYPE_SIZE TYPE VARIABLE)
+  # parse arguments
+  unset(doing)
+  foreach(arg ${ARGN})
+    if("x${arg}" STREQUAL "xBUILTIN_TYPES_ONLY")
+      set(_CHECK_TYPE_SIZE_${arg} 1)
+      unset(doing)
+    elseif("x${arg}" STREQUAL "xLANGUAGE") # change to MATCHES for more keys
+      set(doing "${arg}")
+      set(_CHECK_TYPE_SIZE_${doing} "")
+    elseif("x${doing}" STREQUAL "xLANGUAGE")
+      set(_CHECK_TYPE_SIZE_${doing} "${arg}")
+      unset(doing)
+    else()
+      message(FATAL_ERROR "Unknown argument:\n  ${arg}\n")
+    endif()
+  endforeach()
+  if("x${doing}" MATCHES "^x(LANGUAGE)$")
+    message(FATAL_ERROR "Missing argument:\n  ${doing} arguments requires a value\n")
+  endif()
+  if(DEFINED _CHECK_TYPE_SIZE_LANGUAGE)
+    if(NOT "x${_CHECK_TYPE_SIZE_LANGUAGE}" MATCHES "^x(C|CXX)$")
+      message(FATAL_ERROR "Unknown language:\n  ${_CHECK_TYPE_SIZE_LANGUAGE}.\nSupported languages: C, CXX.\n")
+    endif()
+    set(_language ${_CHECK_TYPE_SIZE_LANGUAGE})
+  else()
+    set(_language C)
+  endif()
+
+  # Optionally check for standard headers.
+  if(_CHECK_TYPE_SIZE_BUILTIN_TYPES_ONLY)
+    set(_builtin 0)
+  else()
+    set(_builtin 1)
+    if("${_language}" STREQUAL "C")
+      check_include_file(sys/types.h HAVE_SYS_TYPES_H)
+      check_include_file(stdint.h HAVE_STDINT_H)
+      check_include_file(stddef.h HAVE_STDDEF_H)
+    elseif("${_language}" STREQUAL "CXX")
+      check_include_file_cxx(sys/types.h HAVE_SYS_TYPES_H)
+      check_include_file_cxx(stdint.h HAVE_STDINT_H)
+      check_include_file_cxx(stddef.h HAVE_STDDEF_H)
+    endif()
+  endif()
+  unset(_CHECK_TYPE_SIZE_BUILTIN_TYPES_ONLY)
+  unset(_CHECK_TYPE_SIZE_LANGUAGE)
+
+  # Compute or load the size or size map.
+  set(${VARIABLE}_KEYS)
+  set(_map_file ${CMAKE_BINARY_DIR}/${CMAKE_FILES_DIRECTORY}/CheckTypeSize/${VARIABLE}.cmake)
+  if(NOT DEFINED HAVE_${VARIABLE})
+    __check_type_size_impl(${TYPE} ${VARIABLE} ${_map_file} ${_builtin} ${_language})
+  endif()
+  include(${_map_file} OPTIONAL)
+  set(_map_file)
+  set(_builtin)
+
+  # Create preprocessor code.
+  if(${VARIABLE}_KEYS)
+    set(${VARIABLE}_CODE)
+    set(_if if)
+    foreach(key ${${VARIABLE}_KEYS})
+      set(${VARIABLE}_CODE "${${VARIABLE}_CODE}#${_if} defined(${key})\n# define ${VARIABLE} ${${VARIABLE}-${key}}\n")
+      set(_if elif)
+    endforeach()
+    set(${VARIABLE}_CODE "${${VARIABLE}_CODE}#else\n# error ${VARIABLE} unknown\n#endif")
+    set(_if)
+  elseif(${VARIABLE})
+    set(${VARIABLE}_CODE "#define ${VARIABLE} ${${VARIABLE}}")
+  else()
+    set(${VARIABLE}_CODE "/* #undef ${VARIABLE} */")
+  endif()
+endmacro()
+
+#-----------------------------------------------------------------------------
+cmake_policy(POP)