TestBigEndian.cmake
# Distributed under the OSI-approved BSD 3-Clause License. See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.
#.rst:
# TestBigEndian
# -------------
#
# Define macro to determine endian type
#
# Check if the system is big endian or little endian
#
# ::
#
# TEST_BIG_ENDIAN(VARIABLE)
# VARIABLE - variable to store the result to
include(CheckTypeSize)
macro(TEST_BIG_ENDIAN VARIABLE)
if(NOT DEFINED HAVE_${VARIABLE})
message(STATUS "Check if the system is big endian")
message(STATUS "Searching 16 bit integer")
if(CMAKE_C_COMPILER_LOADED)
set(_test_language "C")
elseif(CMAKE_CXX_COMPILER_LOADED)
set(_test_language "CXX")
else()
message(FATAL_ERROR "TEST_BIG_ENDIAN needs either C or CXX language enabled")
endif()
CHECK_TYPE_SIZE("unsigned short" CMAKE_SIZEOF_UNSIGNED_SHORT LANGUAGE ${_test_language})
if(CMAKE_SIZEOF_UNSIGNED_SHORT EQUAL 2)
message(STATUS "Using unsigned short")
set(CMAKE_16BIT_TYPE "unsigned short")
else()
CHECK_TYPE_SIZE("unsigned int" CMAKE_SIZEOF_UNSIGNED_INT LANGUAGE ${_test_language})
if(CMAKE_SIZEOF_UNSIGNED_INT)
message(STATUS "Using unsigned int")
set(CMAKE_16BIT_TYPE "unsigned int")
else()
CHECK_TYPE_SIZE("unsigned long" CMAKE_SIZEOF_UNSIGNED_LONG LANGUAGE ${_test_language})
if(CMAKE_SIZEOF_UNSIGNED_LONG)
message(STATUS "Using unsigned long")
set(CMAKE_16BIT_TYPE "unsigned long")
else()
message(FATAL_ERROR "no suitable type found")
endif()
endif()
endif()
if(_test_language STREQUAL "CXX")
set(_test_file "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/TestEndianess.cpp")
else()
set(_test_file "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/TestEndianess.c")
endif()
configure_file("${CMAKE_ROOT}/Modules/TestEndianess.c.in"
${_test_file}
@ONLY)
file(READ ${_test_file} TEST_ENDIANESS_FILE_CONTENT)
try_compile(HAVE_${VARIABLE}
"${CMAKE_BINARY_DIR}"
${_test_file}
OUTPUT_VARIABLE OUTPUT
COPY_FILE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/TestEndianess.bin" )
if(HAVE_${VARIABLE})
file(STRINGS "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/TestEndianess.bin"
CMAKE_TEST_ENDIANESS_STRINGS_LE LIMIT_COUNT 1 REGEX "THIS IS LITTLE ENDIAN")
file(STRINGS "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/TestEndianess.bin"
CMAKE_TEST_ENDIANESS_STRINGS_BE LIMIT_COUNT 1 REGEX "THIS IS BIG ENDIAN")
# on mac, if there are universal binaries built both will be true
# return the result depending on the machine on which cmake runs
if(CMAKE_TEST_ENDIANESS_STRINGS_BE AND CMAKE_TEST_ENDIANESS_STRINGS_LE)
if(CMAKE_SYSTEM_PROCESSOR MATCHES powerpc)
set(CMAKE_TEST_ENDIANESS_STRINGS_BE TRUE)
set(CMAKE_TEST_ENDIANESS_STRINGS_LE FALSE)
else()
set(CMAKE_TEST_ENDIANESS_STRINGS_BE FALSE)
set(CMAKE_TEST_ENDIANESS_STRINGS_LE TRUE)
endif()
message(STATUS "TEST_BIG_ENDIAN found different results, consider setting CMAKE_OSX_ARCHITECTURES or CMAKE_TRY_COMPILE_OSX_ARCHITECTURES to one or no architecture !")
endif()
if(CMAKE_TEST_ENDIANESS_STRINGS_LE)
set(${VARIABLE} 0 CACHE INTERNAL "Result of TEST_BIG_ENDIAN" FORCE)
message(STATUS "Check if the system is big endian - little endian")
endif()
if(CMAKE_TEST_ENDIANESS_STRINGS_BE)
set(${VARIABLE} 1 CACHE INTERNAL "Result of TEST_BIG_ENDIAN" FORCE)
message(STATUS "Check if the system is big endian - big endian")
endif()
if(NOT CMAKE_TEST_ENDIANESS_STRINGS_BE AND NOT CMAKE_TEST_ENDIANESS_STRINGS_LE)
message(SEND_ERROR "TEST_BIG_ENDIAN found no result!")
endif()
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
"Determining if the system is big endian passed with the following output:\n${OUTPUT}\nTestEndianess.c:\n${TEST_ENDIANESS_FILE_CONTENT}\n\n")
else()
message(STATUS "Check if the system is big endian - failed")
file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
"Determining if the system is big endian failed with the following output:\n${OUTPUT}\nTestEndianess.c:\n${TEST_ENDIANESS_FILE_CONTENT}\n\n")
set(${VARIABLE})
endif()
endif()
endmacro()