+AC_CHECK_FUNCS(tzset mbstowcs opendir readdir chdir chroot getuid setlocale strerror strerror_r snprintf vsnprintf fpclass class fp_class isnan memmove strchr mktime getrusage gettimeofday posix_fadvise)
+
+dnl Could use these to know if we need to provide a prototype
+dnl AC_CHECK_DECLS(fdatasync, [], [], [#include <unistd.h>])
+dnl AC_CHECK_DECLS(posix_fadvise, [], [], [#define _XOPEN_SOURCE 600
+dnl #include <fcntl.h>])
+
+dnl XXX: dunno about windows.. add AC_CHECK_FUNCS(munmap) there too?
+if test "x$enable_mmap" = "xyes"; then
+ case "$host" in
+ *cygwin*)
+ # the normal mmap test does not work in cygwin
+ AC_CHECK_FUNCS(mmap)
+ if test "x$ac_cv_func_mmap" = "xyes"; then
+ ac_cv_func_mmap_fixed_mapped=yes
+ fi
+ ;;
+ *)
+ AC_CHECK_HEADERS(sys/mman.h)
+ AC_FUNC_MMAP
+ AC_CHECK_FUNCS(mmap munmap)
+ AC_CHECK_DECLS(madvise, [], [], [#ifdef HAVE_SYS_MMAN_H
+ # include <sys/mman.h>
+ #endif])
+ if test "x$ac_cv_have_decl_madvise" = "xyes";
+ then
+ AC_CHECK_FUNCS(madvise)
+ else
+ AC_CHECK_FUNCS(posix_madvise)
+ if test "x$ac_cv_func_posix_madvise" != "xyes"; then
+ AC_MSG_WARN([madvise() nor posix_madvise() found.])
+ fi
+ fi
+ ;;
+ esac
+ if test "x$ac_cv_func_mmap" != "xyes";
+ then
+ AC_MSG_ERROR([--enable-mmap requested but mmap() was not detected])
+ fi