macros/largefile-check.m4

   1 dnl -------------------------------------------------------------------
   2 dnl This test for largefile support was written by Vadim Zeitlin for
   3 dnl wxWindows.
   4 dnl -------------------------------------------------------------------
   5
   6 dnl WX_SYS_LARGEFILE_TEST
   7 dnl
   8 dnl NB: original autoconf test was checking if compiler supported 6 bit off_t
   9 dnl     arithmetic properly but this failed miserably with gcc under Linux
  10 dnl     whereas the system still supports 64 bit files, so now simply check
  11 dnl     that off_t is big enough
  12 define(WX_SYS_LARGEFILE_TEST,
  13 [typedef struct {
  14     unsigned int field: sizeof(off_t) == 8;
  15 } wxlf;
  16 ])
  17
  18 dnl WX_SYS_LARGEFILE_MACRO_VALUE(C-MACRO, VALUE, CACHE-VAR)
  19 define(WX_SYS_LARGEFILE_MACRO_VALUE,
  20 [
  21     AC_CACHE_CHECK([for $1 value needed for large files], [$3],
  22         [
  23           AC_TRY_COMPILE([#define $1 $2
  24                           #include <sys/types.h>],
  25                          WX_SYS_LARGEFILE_TEST,
  26                          [$3=$2],
  27                          [$3=no])
  28         ]
  29     )
  30
  31     if test "$$3" != no; then
  32         wx_largefile=yes
  33         AC_DEFINE_UNQUOTED([$1], [$$3], [$1 (for LARGEFILE support)])
  34     fi
  35 ])
  36
  37
  38
  39
  40 dnl AC_SYS_LARGEFILE
  41 dnl ----------------
  42 dnl By default, many hosts won't let programs access large files;
  43 dnl one must use special compiler options to get large-file access to work.
  44 dnl For more details about this brain damage please see:
  45 dnl http://www.sas.com/standards/large.file/x_open.20Mar96.html
  46 AC_DEFUN([AC_SYS_LARGEFILE],
  47 [AC_ARG_ENABLE(largefile,
  48                [  --disable-largefile     omit support for large files])
  49 if test "$enable_largefile" != no; then
  50     dnl _FILE_OFFSET_BITS==64 is needed for Linux, Solaris, ...
  51     dnl _LARGE_FILES -- for AIX
  52     wx_largefile=no
  53     WX_SYS_LARGEFILE_MACRO_VALUE(_FILE_OFFSET_BITS, 64, ac_cv_sys_file_offset_bits)
  54     if test "x$wx_largefile" != "xyes"; then
  55         WX_SYS_LARGEFILE_MACRO_VALUE(_LARGE_FILES, 1, ac_cv_sys_large_files)
  56     fi
  57
  58
  59     AC_CACHE_CHECK([for 64 bit off_t],netatalk_cv_SIZEOF_OFF_T,[
  60     AC_TRY_RUN([#include <stdio.h>
  61 #include <stdlib.h>
  62 #include <sys/stat.h>
  63 main() { exit((sizeof(off_t) == 8) ? 0 : 1); }],
  64 netatalk_cv_SIZEOF_OFF_T=yes,netatalk_cv_SIZEOF_OFF_T=no,netatalk_cv_SIZEOF_OFF_T=cross)])
  65
  66     AC_MSG_CHECKING([if large file support is available])
  67     if test "x$netatalk_cv_SIZEOF_OFF_T" != "xno"; then
  68         AC_DEFINE(HAVE_LARGEFILE_SUPPORT, [], [LARGEFILE support])
  69         AC_MSG_RESULT([yes])
  70         ifelse([$1], , :, [$1])
  71     else
  72         AC_MSG_RESULT([no])
  73         ifelse([$2], , :, [$2])
  74     fi
  75 fi
  76 ])
  77
  78 dnl ----------end of largefile test------------------------------------