llvm-mirror/autoconf/m4/header_mmap_anonymous.m4
2004-12-27 03:14:43 +00:00

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#
# Check for anonymous mmap macros. This is modified from
# http://www.gnu.org/software/ac-archive/htmldoc/ac_cxx_have_ext_slist.html
#
AC_DEFUN([AC_HEADER_MMAP_ANONYMOUS],
[AC_CACHE_CHECK(for MAP_ANONYMOUS vs. MAP_ANON,
ac_cv_header_mmap_anon,
[ AC_LANG_PUSH([C])
AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
[[#include <sys/mman.h>
#include <unistd.h>
#include <fcntl.h>]],
[[mmap (0, 1, PROT_READ, MAP_ANONYMOUS, -1, 0); return (0);]])],
ac_cv_header_mmap_anon=yes,
ac_cv_header_mmap_anon=no)
AC_LANG_POP([C])
])
if test "$ac_cv_header_mmap_anon" = yes; then
AC_DEFINE([HAVE_MMAP_ANONYMOUS],[1],[Define if mmap() uses MAP_ANONYMOUS to map anonymous pages, or undefine if it uses MAP_ANON])
fi
])