+dnl This macro can be used to emulate POSIX linkat. If
+dnl LINK_FOLLOWS_SYMLINKS is 0, link matches linkat(,0), and
+dnl linkat(,AT_SYMLINK_FOLLOW) requires a readlink. If it is 1,
+dnl link matches linkat(,AT_SYMLINK_FOLLOW), and there is no way
+dnl to do linkat(,0) on symlinks (on all other file types,
+dnl link() is sufficient). If it is -1, use a runtime test.
+AC_DEFUN([gl_FUNC_LINK_FOLLOWS_SYMLINK],
+[dnl
+ AC_CHECK_FUNCS_ONCE([readlink])
+ dnl Mingw lacks link, although gnulib provides a good replacement.
+ dnl However, it also lacks symlink, so there's nothing to test in
+ dnl the first place, and no reason to need to distinguish between
+ dnl linkat variants. So, we set LINK_FOLLOWS_SYMLINKS to 0.
+ gl_link_follows_symlinks=0 # assume GNU behavior
+ if test $ac_cv_func_readlink = yes; then
+ AC_CACHE_CHECK([whether link(2) dereferences a symlink],
+ gl_cv_func_link_follows_symlink,
+ [
+ # Create a regular file.
+ echo > conftest.file
+ AC_RUN_IFELSE([AC_LANG_SOURCE([[