1 # Distributed under the OSI-approved BSD 3-Clause License. See accompanying
2 # file Copyright.txt or https://cmake.org/licensing for details.
4 #[=======================================================================[.rst:
10 Supserseded by the :variable:`CMAKE_<LANG>_BYTE_ORDER` variable.
12 Check if the target architecture is big endian or little endian.
14 .. command:: test_big_endian
18 test_big_endian(<var>)
20 Stores in variable ``<var>`` either 1 or 0 indicating whether the
21 target architecture is big or little endian.
23 #]=======================================================================]
26 include(CheckTypeSize)
28 function(TEST_BIG_ENDIAN VARIABLE)
29 if(";${CMAKE_C_BYTE_ORDER};${CMAKE_CXX_BYTE_ORDER};${CMAKE_CUDA_BYTE_ORDER};${CMAKE_OBJC_BYTE_ORDER};${CMAKE_OBJCXX_BYTE_ORDER};" MATCHES ";(BIG_ENDIAN|LITTLE_ENDIAN);")
30 set(order "${CMAKE_MATCH_1}")
31 if(order STREQUAL "BIG_ENDIAN")
32 set("${VARIABLE}" 1 PARENT_SCOPE)
34 set("${VARIABLE}" 0 PARENT_SCOPE)
37 __TEST_BIG_ENDIAN_LEGACY_IMPL(is_big)
38 set("${VARIABLE}" "${is_big}" PARENT_SCOPE)
42 macro(__TEST_BIG_ENDIAN_LEGACY_IMPL VARIABLE)
43 if(NOT DEFINED HAVE_${VARIABLE})
44 message(CHECK_START "Check if the system is big endian")
45 message(CHECK_START "Searching 16 bit integer")
47 if(CMAKE_C_COMPILER_LOADED)
48 set(_test_language "C")
49 elseif(CMAKE_CXX_COMPILER_LOADED)
50 set(_test_language "CXX")
52 message(FATAL_ERROR "TEST_BIG_ENDIAN needs either C or CXX language enabled")
55 check_type_size("unsigned short" CMAKE_SIZEOF_UNSIGNED_SHORT LANGUAGE ${_test_language})
56 if(CMAKE_SIZEOF_UNSIGNED_SHORT EQUAL 2)
57 message(CHECK_PASS "Using unsigned short")
58 set(CMAKE_16BIT_TYPE "unsigned short")
60 check_type_size("unsigned int" CMAKE_SIZEOF_UNSIGNED_INT LANGUAGE ${_test_language})
61 if(CMAKE_SIZEOF_UNSIGNED_INT)
62 message(CHECK_PASS "Using unsigned int")
63 set(CMAKE_16BIT_TYPE "unsigned int")
67 check_type_size("unsigned long" CMAKE_SIZEOF_UNSIGNED_LONG LANGUAGE ${_test_language})
68 if(CMAKE_SIZEOF_UNSIGNED_LONG)
69 message(CHECK_PASS "Using unsigned long")
70 set(CMAKE_16BIT_TYPE "unsigned long")
72 message(FATAL_ERROR "no suitable type found")
79 if(_test_language STREQUAL "CXX")
80 set(_test_file TestEndianness.cpp)
82 set(_test_file TestEndianness.c)
85 file(READ "${CMAKE_ROOT}/Modules/TestEndianness.c.in" TEST_ENDIANNESS_FILE_CONTENT)
86 string(CONFIGURE "${TEST_ENDIANNESS_FILE_CONTENT}" TEST_ENDIANNESS_FILE_CONTENT @ONLY)
88 try_compile(HAVE_${VARIABLE}
89 SOURCE_FROM_VAR "${_test_file}" TEST_ENDIANNESS_FILE_CONTENT
90 COPY_FILE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/TestEndianness.bin" )
95 cmake_policy(SET CMP0159 NEW) # file(STRINGS) with REGEX updates CMAKE_MATCH_<n>
97 file(STRINGS "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/TestEndianness.bin"
98 CMAKE_TEST_ENDIANNESS_STRINGS_LE LIMIT_COUNT 1 REGEX "THIS IS LITTLE ENDIAN")
100 file(STRINGS "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/TestEndianness.bin"
101 CMAKE_TEST_ENDIANNESS_STRINGS_BE LIMIT_COUNT 1 REGEX "THIS IS BIG ENDIAN")
105 # on mac, if there are universal binaries built both will be true
106 # return the result depending on the machine on which cmake runs
107 if(CMAKE_TEST_ENDIANNESS_STRINGS_BE AND CMAKE_TEST_ENDIANNESS_STRINGS_LE)
108 if(CMAKE_SYSTEM_PROCESSOR MATCHES powerpc)
109 set(CMAKE_TEST_ENDIANNESS_STRINGS_BE TRUE)
110 set(CMAKE_TEST_ENDIANNESS_STRINGS_LE FALSE)
112 set(CMAKE_TEST_ENDIANNESS_STRINGS_BE FALSE)
113 set(CMAKE_TEST_ENDIANNESS_STRINGS_LE TRUE)
117 "TEST_BIG_ENDIAN found different results, consider setting CMAKE_OSX_ARCHITECTURES or "
118 "CMAKE_TRY_COMPILE_OSX_ARCHITECTURES to one or no architecture !"
122 if(CMAKE_TEST_ENDIANNESS_STRINGS_LE)
123 set(${VARIABLE} 0 CACHE INTERNAL "Result of TEST_BIG_ENDIAN" FORCE)
124 message(CHECK_PASS "little endian")
127 if(CMAKE_TEST_ENDIANNESS_STRINGS_BE)
128 set(${VARIABLE} 1 CACHE INTERNAL "Result of TEST_BIG_ENDIAN" FORCE)
129 message(CHECK_PASS "big endian")
132 if(NOT CMAKE_TEST_ENDIANNESS_STRINGS_BE AND NOT CMAKE_TEST_ENDIANNESS_STRINGS_LE)
133 message(CHECK_FAIL "TEST_BIG_ENDIAN found no result!")
134 message(SEND_ERROR "TEST_BIG_ENDIAN found no result!")
137 message(CHECK_FAIL "failed")