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Diffstat (limited to 'm4/largefile.m4')
| -rw-r--r-- | m4/largefile.m4 | 92 |
1 files changed, 92 insertions, 0 deletions
diff --git a/m4/largefile.m4 b/m4/largefile.m4 new file mode 100644 index 00000000..db38757d --- /dev/null +++ b/m4/largefile.m4 @@ -0,0 +1,92 @@ +#serial 19 + +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> + /* Check that off_t can represent 2**63 - 1 correctly. + We can't simply "#define LARGE_OFF_T 9223372036854775807", + since some C++ compilers masquerading as C compilers + incorrectly reject 9223372036854775807. */ +# define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62)) + int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721 + && LARGE_OFF_T % 2147483647 == 1) + ? 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([$5], + [$6], + , + [AC_TRY_COMPILE([#define $1 $2] +[$5] + , + [$6], + [$3=$2])])]) + if test "[$]$3" != no; then + AC_DEFINE_UNQUOTED([$1], [$]$3, [$4]) + fi]) + +AC_DEFUN(AC_SYS_LARGEFILE, + [AC_REQUIRE([AC_PROG_CC]) + AC_ARG_ENABLE(largefile, + [ --disable-largefile omit support for large files]) + if test "$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_TEST_INCLUDES) + AC_SYS_LARGEFILE_MACRO_VALUE(_LARGE_FILES, 1, + ac_cv_sys_large_files, + [Define for large files, on AIX-style hosts.], + AC_SYS_LARGEFILE_TEST_INCLUDES) + fi + ]) + +AC_DEFUN(AC_FUNC_FSEEKO, + [AC_SYS_LARGEFILE_MACRO_VALUE(_LARGEFILE_SOURCE, 1, + ac_cv_sys_largefile_source, + [Define to make fseeko visible on some hosts (e.g. glibc 2.2).], + [#include <stdio.h>], [return !fseeko;]) + # We used to try defining _XOPEN_SOURCE=500 too, to work around a bug + # in glibc 2.1.3, but that breaks too many other things. + # If you want fseeko and ftello with glibc, upgrade to a fixed glibc. + + AC_CACHE_CHECK([for fseeko], ac_cv_func_fseeko, + [ac_cv_func_fseeko=no + AC_TRY_LINK([#include <stdio.h>], + [return fseeko && fseeko (stdin, 0, 0);], + [ac_cv_func_fseeko=yes])]) + if test $ac_cv_func_fseeko != no; then + AC_DEFINE(HAVE_FSEEKO, 1, + [Define if fseeko (and presumably ftello) exists and is declared.]) + fi]) |