1 # CMake support for large files 2 # 3 # Copyright (C) 2016 Julian Andres Klode <jak (a] debian.org>. 4 # 5 # Permission is hereby granted, free of charge, to any person 6 # obtaining a copy of this software and associated documentation files 7 # (the "Software"), to deal in the Software without restriction, 8 # including without limitation the rights to use, copy, modify, merge, 9 # publish, distribute, sublicense, and/or sell copies of the Software, 10 # and to permit persons to whom the Software is furnished to do so, 11 # subject to the following conditions: 12 # 13 # The above copyright notice and this permission notice shall be 14 # included in all copies or substantial portions of the Software. 15 # 16 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 17 # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 18 # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 19 # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 20 # BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 21 # ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 22 # CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 23 # SOFTWARE. 24 # 25 # This defines the following variables 26 # 27 # LFS_DEFINITIONS - List of definitions to pass to add_definitions() 28 # LFS_COMPILE_OPTIONS - List of definitions to pass to add_compile_options() 29 # LFS_LIBRARIES - List of libraries and linker flags 30 # LFS_FOUND - If there is Large files support 31 # 32 33 include(CheckCSourceCompiles) 34 include(FindPackageHandleStandardArgs) 35 include(CMakePushCheckState) 36 37 # Test program to check for LFS. Requires that off_t has at least 8 byte large 38 set(_lfs_test_source 39 " 40 #include <sys/types.h> 41 typedef char my_static_assert[sizeof(off_t) >= 8 ? 1 : -1]; 42 int main(void) { return 0; } 43 " 44 ) 45 46 # Check if the given options are needed 47 # 48 # This appends to the variables _lfs_cppflags, _lfs_cflags, and _lfs_ldflags, 49 # it also sets LFS_FOUND to 1 if it works. 50 function(_lfs_check_compiler_option var options definitions libraries) 51 cmake_push_check_state() 52 set(CMAKE_REQUIRED_QUIET 1) 53 set(CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS} ${options}) 54 set(CMAKE_REQUIRED_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS} ${definitions}) 55 set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_DEFINITIONS} ${libraries}) 56 57 message(STATUS "Looking for LFS support using ${options} ${definitions} ${libraries}") 58 check_c_source_compiles("${_lfs_test_source}" ${var}) 59 cmake_pop_check_state() 60 61 if(${var}) 62 message(STATUS "Looking for LFS support using ${options} ${definitions} ${libraries} - found") 63 set(_lfs_cppflags ${_lfs_cppflags} ${definitions} PARENT_SCOPE) 64 set(_lfs_cflags ${_lfs_cflags} ${options} PARENT_SCOPE) 65 set(_lfs_ldflags ${_lfs_ldflags} ${libraries} PARENT_SCOPE) 66 set(LFS_FOUND TRUE PARENT_SCOPE) 67 else() 68 message(STATUS "Looking for LFS support using ${options} ${definitions} ${libraries} - not found") 69 endif() 70 endfunction() 71 72 # Check for the availability of LFS. 73 # The cases handled are: 74 # 75 # * Native LFS 76 # * Output of getconf LFS_CFLAGS; getconf LFS_LIBS; getconf LFS_LDFLAGS 77 # * Preprocessor flag -D_FILE_OFFSET_BITS=64 78 # * Preprocessor flag -D_LARGE_FILES 79 # 80 function(_lfs_check) 81 set(_lfs_cflags) 82 set(_lfs_cppflags) 83 set(_lfs_ldflags) 84 set(_lfs_libs) 85 cmake_push_check_state() 86 set(CMAKE_REQUIRED_QUIET 1) 87 message(STATUS "Looking for native LFS support") 88 check_c_source_compiles("${_lfs_test_source}" lfs_native) 89 cmake_pop_check_state() 90 if (lfs_native) 91 message(STATUS "Looking for native LFS support - found") 92 set(LFS_FOUND TRUE) 93 else() 94 message(STATUS "Looking for native LFS support - not found") 95 endif() 96 97 if (NOT LFS_FOUND) 98 # Check using getconf. If getconf fails, don't worry, the check in 99 # _lfs_check_compiler_option will fail as well. 100 execute_process(COMMAND getconf LFS_CFLAGS 101 OUTPUT_VARIABLE _lfs_cflags_raw 102 OUTPUT_STRIP_TRAILING_WHITESPACE 103 ERROR_QUIET) 104 execute_process(COMMAND getconf LFS_LIBS 105 OUTPUT_VARIABLE _lfs_libs_tmp 106 OUTPUT_STRIP_TRAILING_WHITESPACE 107 ERROR_QUIET) 108 execute_process(COMMAND getconf LFS_LDFLAGS 109 OUTPUT_VARIABLE _lfs_ldflags_tmp 110 OUTPUT_STRIP_TRAILING_WHITESPACE 111 ERROR_QUIET) 112 113 separate_arguments(_lfs_cflags_raw) 114 separate_arguments(_lfs_ldflags_tmp) 115 separate_arguments(_lfs_libs_tmp) 116 117 # Move -D flags to the place they are supposed to be 118 foreach(flag ${_lfs_cflags_raw}) 119 if (flag MATCHES "-D.*") 120 list(APPEND _lfs_cppflags_tmp ${flag}) 121 else() 122 list(APPEND _lfs_cflags_tmp ${flag}) 123 endif() 124 endforeach() 125 126 # Check if the flags we received (if any) produce working LFS support 127 _lfs_check_compiler_option(lfs_getconf_works 128 "${_lfs_cflags_tmp}" 129 "${_lfs_cppflags_tmp}" 130 "${_lfs_libs_tmp};${_lfs_ldflags_tmp}") 131 endif() 132 133 if(NOT LFS_FOUND) # IRIX stuff 134 _lfs_check_compiler_option(lfs_need_n32 "-n32" "" "") 135 endif() 136 if(NOT LFS_FOUND) # Linux and friends 137 _lfs_check_compiler_option(lfs_need_file_offset_bits "" "-D_FILE_OFFSET_BITS=64" "") 138 endif() 139 if(NOT LFS_FOUND) # AIX 140 _lfs_check_compiler_option(lfs_need_large_files "" "-D_LARGE_FILES=1" "") 141 endif() 142 143 set(LFS_DEFINITIONS ${_lfs_cppflags} CACHE STRING "Extra definitions for large file support") 144 set(LFS_COMPILE_OPTIONS ${_lfs_cflags} CACHE STRING "Extra definitions for large file support") 145 set(LFS_LIBRARIES ${_lfs_libs} ${_lfs_ldflags} CACHE STRING "Extra definitions for large file support") 146 set(LFS_FOUND ${LFS_FOUND} CACHE INTERNAL "Found LFS") 147 endfunction() 148 149 if (NOT LFS_FOUND) 150 _lfs_check() 151 endif() 152 153 find_package_handle_standard_args(LFS "Could not find LFS. Set LFS_DEFINITIONS, LFS_COMPILE_OPTIONS, LFS_LIBRARIES." LFS_FOUND) 154
