cmake/gmxTestLargeFiles.cmake

   1 # - Define macro to check large file support
   2 #
   3 #  GMX_TEST_LARGE_FILES(VARIABLE)
   4 #
   5 #  VARIABLE will be set to true if off_t is 64 bits, and fseeko/ftello present.
   6 #  This macro will also set defines necessary enable large file support, for instance
   7 #  _LARGE_FILES
   8 #  _LARGEFILE_SOURCE
   9 #  _FILE_OFFSET_BITS 64
  10 #
  11 #  However, it is YOUR job to make sure these defines are set in a cmakedefine so they
  12 #  end up in a config.h file that is included in your source if necessary!
  13
  14 MACRO(GMX_TEST_LARGE_FILES VARIABLE)
  15     IF(NOT DEFINED ${VARIABLE})
  16
  17         # On most platforms it is probably overkill to first test the flags for 64-bit off_t,
  18         # and then separately fseeko. However, in the future we might have 128-bit filesystems
  19         # (ZFS), so it might be dangerous to indiscriminately set e.g. _FILE_OFFSET_BITS=64.
  20
  21         MESSAGE(STATUS "Checking for 64-bit off_t")
  22
  23         # First check without any special flags
  24         TRY_COMPILE(FILE64_OK "${CMAKE_BINARY_DIR}"
  25                     "${CMAKE_SOURCE_DIR}/cmake/TestFileOffsetBits.c")
  26         if(FILE64_OK)
  27             MESSAGE(STATUS "Checking for 64-bit off_t - present")
  28         endif(FILE64_OK)
  29
  30         if(NOT FILE64_OK)
  31             # Test with _FILE_OFFSET_BITS=64
  32             TRY_COMPILE(FILE64_OK "${CMAKE_BINARY_DIR}"
  33                         "${CMAKE_SOURCE_DIR}/cmake/TestFileOffsetBits.c"
  34                         COMPILE_DEFINITIONS "-D_FILE_OFFSET_BITS=64" )
  35             if(FILE64_OK)
  36                 MESSAGE(STATUS "Checking for 64-bit off_t - present with _FILE_OFFSET_BITS=64")
  37                 set(_FILE_OFFSET_BITS 64)
  38             endif(FILE64_OK)
  39         endif(NOT FILE64_OK)
  40
  41         if(NOT FILE64_OK)
  42             # Test with _LARGE_FILES
  43             TRY_COMPILE(FILE64_OK "${CMAKE_BINARY_DIR}"
  44                         "${CMAKE_SOURCE_DIR}/cmake/TestFileOffsetBits.c"
  45                         COMPILE_DEFINITIONS "-D_LARGE_FILES" )
  46             if(FILE64_OK)
  47                 MESSAGE(STATUS "Checking for 64-bit off_t - present with _LARGE_FILES")
  48                 set(_LARGE_FILES 1)
  49             endif(FILE64_OK)
  50         endif(NOT FILE64_OK)
  51
  52         if(NOT FILE64_OK)
  53             # Test with _LARGEFILE_SOURCE
  54             TRY_COMPILE(FILE64_OK "${CMAKE_BINARY_DIR}"
  55                         "${CMAKE_SOURCE_DIR}/cmake/TestFileOffsetBits.c"
  56                         COMPILE_DEFINITIONS "-D_LARGEFILE_SOURCE" )
  57             if(FILE64_OK)
  58                 MESSAGE(STATUS "Checking for 64-bit off_t - present with _LARGEFILE_SOURCE")
  59                                set(_LARGEFILE_SOURCE 1)
  60             endif(FILE64_OK)
  61         endif(NOT FILE64_OK)
  62
  63         if(NOT FILE64_OK)
  64             # now check for Windows stuff
  65             TRY_COMPILE(FILE64_OK "${CMAKE_BINARY_DIR}"
  66                         "${CMAKE_SOURCE_DIR}/cmake/TestWindowsFSeek.c")
  67             if(FILE64_OK)
  68                 MESSAGE(STATUS "Checking for 64-bit off_t - present with _fseeki64")
  69                 set(HAVE__FSEEKI64 1)
  70             endif(FILE64_OK)
  71         endif(NOT FILE64_OK)
  72
  73         if(NOT FILE64_OK)
  74             MESSAGE(STATUS "Checking for 64-bit off_t - not present")
  75         else(NOT FILE64_OK)
  76
  77             # Set the flags we might have determined to be required above
  78             configure_file("${CMAKE_SOURCE_DIR}/cmake/TestLargeFiles.c.cmakein"
  79                            "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/TestLargeFiles.c")
  80
  81             MESSAGE(STATUS "Checking for fseeko/ftello")
  82             # Test if ftello/fseeko are available
  83             TRY_COMPILE(FSEEKO_COMPILE_OK "${CMAKE_BINARY_DIR}"
  84                         "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/TestLargeFiles.c")
  85             if(FSEEKO_COMPILE_OK)
  86                 MESSAGE(STATUS "Checking for fseeko/ftello - present")
  87             endif(FSEEKO_COMPILE_OK)
  88
  89             if(NOT FSEEKO_COMPILE_OK)
  90                 # glibc 2.2 neds _LARGEFILE_SOURCE for fseeko (but not 64-bit off_t...)
  91                 TRY_COMPILE(FSEEKO_COMPILE_OK "${CMAKE_BINARY_DIR}"
  92                             "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/TestLargeFiles.c"
  93                             COMPILE_DEFINITIONS "-D_LARGEFILE_SOURCE" )
  94                 if(FSEEKO_COMPILE_OK)
  95                     MESSAGE(STATUS "Checking for fseeko/ftello - present with _LARGEFILE_SOURCE")
  96                     set(_LARGEFILE_SOURCE 1)
  97                 endif(FSEEKO_COMPILE_OK)
  98             endif(NOT FSEEKO_COMPILE_OK)
  99
 100         endif(NOT FILE64_OK)
 101
 102             if(FSEEKO_COMPILE_OK)
 103                 SET(${VARIABLE} 1 CACHE INTERNAL "Result of test for large file support" FORCE)
 104         else(FSEEKO_COMPILE_OK)
 105                         if (HAVE__FSEEKI64)
 106                                 SET(${VARIABLE} 1 CACHE INTERNAL "Result of test for large file support" FORCE)
 107                                 SET(HAVE__FSEEKI64 1 CACHE INTERNAL "Windows 64-bit fseek" FORCE)
 108                         else (HAVE__FSEEKI64)
 109                 MESSAGE(STATUS "Checking for fseeko/ftello - not found")
 110                 SET(${VARIABLE} 0 CACHE INTERNAL "Result of test for large file support" FORCE)
 111                         endif (HAVE__FSEEKI64)
 112         endif(FSEEKO_COMPILE_OK)
 113
 114     ENDIF(NOT DEFINED ${VARIABLE})
 115 ENDMACRO(GMX_TEST_LARGE_FILES VARIABLE)
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