-# serial 15
+# serial 16
dnl Run a program to determine whether link(2) follows symlinks.
dnl Set LINK_FOLLOWS_SYMLINKS accordingly.
-# Copyright (C) 1999-2001, 2004-2006, 2009-2010 Free Software Foundation, Inc.
+# Copyright (C) 1999-2001, 2004-2006, 2009-2011 Free Software Foundation, Inc.
# This file is free software; the Free Software Foundation
# gives unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.
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.
+dnl link() is sufficient). If it is -1, use a Solaris specific
+dnl runtime test. If it is -2, use a generic runtime test.
AC_DEFUN([gl_FUNC_LINK_FOLLOWS_SYMLINK],
[dnl
AC_CHECK_FUNCS_ONCE([readlink])
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([[
+ dnl Solaris has an __xpg4 variable in libc, and it determines the
+ dnl behaviour of link(): It dereferences a symlink if and only if
+ dnl __xpg4 != 0.
+ AC_CACHE_CHECK([for __xpg4], [gl_cv_have___xpg4],
+ [AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[extern int __xpg4;]],
+ [[return __xpg4;]])],
+ [gl_cv_have___xpg4=yes],
+ [gl_cv_have___xpg4=no])
+ ])
+ if test $gl_cv_have___xpg4 = yes; then
+ gl_link_follows_symlinks=-1
+ else
+ 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([[
# include <sys/types.h>
# include <sys/stat.h>
# include <unistd.h>
the link call followed the symlink. */
return SAME_INODE (sb_hard, sb_file) ? 1 : 0;
}
- ]])],
- [gl_cv_func_link_follows_symlink=no], dnl GNU behavior
- [gl_cv_func_link_follows_symlink=yes], dnl Followed link/compile failed
- [gl_cv_func_link_follows_symlink=unknown] dnl We're cross compiling.
- )
- rm -f conftest.file conftest.sym conftest.hard
- ])
- case $gl_cv_func_link_follows_symlink in
- yes) gl_link_follows_symlinks=1 ;;
- no) ;; # already defaulted to 0
- *) gl_link_follows_symlinks=-1 ;;
- esac
+ ]])],
+ [gl_cv_func_link_follows_symlink=no], dnl GNU behavior
+ [gl_cv_func_link_follows_symlink=yes], dnl Followed link/compile failed
+ [gl_cv_func_link_follows_symlink=unknown] dnl We're cross compiling.
+ )
+ rm -f conftest.file conftest.sym conftest.hard
+ ])
+ case $gl_cv_func_link_follows_symlink in
+ yes) gl_link_follows_symlinks=1 ;;
+ no) ;; # already defaulted to 0
+ *) gl_link_follows_symlinks=-2 ;;
+ esac
+ fi
fi
AC_DEFINE_UNQUOTED([LINK_FOLLOWS_SYMLINKS], [$gl_link_follows_symlinks],
[Define to 1 if `link(2)' dereferences symbolic links, 0 if it
- creates hard links to symlinks, and -1 if unknown.])
+ creates hard links to symlinks, -1 if it depends on the variable __xpg4,
+ and -2 if unknown.])
])