1 files changed, 73 insertions, 0 deletions

diff --git a/aclocal.m4 b/aclocal.m4
index 1c013640eff..0238e0c8cda 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -277,3 +277,76 @@ else
   AC_MSG_RESULT(no)
 fi
 ])# AC_C_PROTOTYPES
+
+dnl By default, many hosts won't let programs access large files;
+dnl one must use special compiler options to get large-file access to work.
+dnl For more details about this brain damage please see:
+dnl http://www.sas.com/standards/large.file/x_open.20Mar96.html
+
+dnl Written by Paul Eggert <eggert@twinsun.com>.
+
+dnl Internal subroutine of AC_SYS_LARGEFILE.
+dnl AC_SYS_LARGEFILE_TEST_INCLUDES
+AC_DEFUN(AC_SYS_LARGEFILE_TEST_INCLUDES,
+  [[#include <sys/types.h>
+    int a[(off_t) 9223372036854775807 == 9223372036854775807 ? 1 : -1];
+  ]])
+
+dnl Internal subroutine of AC_SYS_LARGEFILE.
+dnl AC_SYS_LARGEFILE_MACRO_VALUE(C-MACRO, VALUE, CACHE-VAR, COMMENT, INCLUDES, FUNCTION-BODY)
+AC_DEFUN(AC_SYS_LARGEFILE_MACRO_VALUE,
+  [AC_CACHE_CHECK([for $1 value needed for large files], $3,
+     [$3=no
+      AC_TRY_COMPILE(AC_SYS_LARGEFILE_TEST_INCLUDES
+$5
+        ,
+        [$6], 
+        ,
+        [AC_TRY_COMPILE([#define $1 $2]
+AC_SYS_LARGEFILE_TEST_INCLUDES
+$5
+           ,
+           [$6],
+           [$3=$2])])])
+   if test "[$]$3" != no; then
+     AC_DEFINE_UNQUOTED([$1], [$]$3, [$4])
+   fi])
+
+AC_DEFUN(AC_SYS_LARGEFILE,
+  [AC_ARG_ENABLE(largefile,
+     [  --disable-largefile     omit support for large files])
+   if test "$enable_largefile" != no; then
+
+     AC_CACHE_CHECK([for special C compiler options needed for large files],
+       ac_cv_sys_largefile_CC,
+       [ac_cv_sys_largefile_CC=no
+        if test "$GCC" != yes; then
+          # IRIX 6.2 and later do not support large files by default,
+          # so use the C compiler's -n32 option if that helps.
+          AC_TRY_COMPILE(AC_SYS_LARGEFILE_TEST_INCLUDES, , ,
+            [ac_save_CC="$CC"
+             CC="$CC -n32"
+             AC_TRY_COMPILE(AC_SYS_LARGEFILE_TEST_INCLUDES, ,
+               ac_cv_sys_largefile_CC=' -n32')
+             CC="$ac_save_CC"])
+        fi])
+     if test "$ac_cv_sys_largefile_CC" != no; then
+       CC="$CC$ac_cv_sys_largefile_CC"
+     fi
+
+     AC_SYS_LARGEFILE_MACRO_VALUE(_FILE_OFFSET_BITS, 64,
+       ac_cv_sys_file_offset_bits,
+       [Number of bits in a file offset, on hosts where this is settable.])
+     AC_SYS_LARGEFILE_MACRO_VALUE(_LARGEFILE_SOURCE, 1,
+       ac_cv_sys_largefile_source,
+       [Define to make ftello visible on some hosts (e.g. HP-UX 10.20).],
+       [#include <stdio.h>], [return !ftello;])
+     AC_SYS_LARGEFILE_MACRO_VALUE(_LARGE_FILES, 1,
+       ac_cv_sys_large_files,
+       [Define for large files, on AIX-style hosts.])
+     AC_SYS_LARGEFILE_MACRO_VALUE(_XOPEN_SOURCE, 500,
+       ac_cv_sys_xopen_source,
+       [Define to make ftello visible on some hosts (e.g. glibc 2.1.3).],
+       [#include <stdio.h>], [return !ftello;])
+   fi
+  ])